* [PATCH v5 01/23] sg: move functions around
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 02/23] sg: remove typedefs, type+formatting cleanup Douglas Gilbert
` (21 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare, Hannes Reinecke
Move main entry point functions around so submission code comes
before completion code. Prior to this, the driver used the
traditional open(), close(), read(), write(), ioctl() ordering
however in this case that places completion code (i.e.
sg_read()) before submission code (i.e. sg_write()). The main
driver entry points are considered to be those named in struct
file_operations sg_fops' definition.
Helper functions are often placed above their caller to reduce
the number of forward function declarations needed.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 499 ++++++++++++++++++++++++----------------------
1 file changed, 261 insertions(+), 238 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index cce757506383..9f1587761d86 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -8,11 +8,12 @@
* Original driver (sg.c):
* Copyright (C) 1992 Lawrence Foard
* Version 2 and 3 extensions to driver:
- * Copyright (C) 1998 - 2014 Douglas Gilbert
+ * Copyright (C) 1998 - 2019 Douglas Gilbert
*/
-static int sg_version_num = 30536; /* 2 digits for each component */
-#define SG_VERSION_STR "3.5.36"
+static int sg_version_num = 30901; /* [x]xyyzz where [x] empty when x=0 */
+#define SG_VERSION_STR "3.9.01" /* [x]x.[y]y.zz */
+static char *sg_version_date = "20190606";
/*
* D. P. Gilbert (dgilbert@interlog.com), notes:
@@ -47,6 +48,7 @@ static int sg_version_num = 30536; /* 2 digits for each component */
#include <linux/ratelimit.h>
#include <linux/uio.h>
#include <linux/cred.h> /* for sg_check_file_access() */
+#include <linux/proc_fs.h>
#include "scsi.h"
#include <scsi/scsi_dbg.h>
@@ -57,12 +59,6 @@ static int sg_version_num = 30536; /* 2 digits for each component */
#include "scsi_logging.h"
-#ifdef CONFIG_SCSI_PROC_FS
-#include <linux/proc_fs.h>
-static char *sg_version_date = "20140603";
-
-static int sg_proc_init(void);
-#endif
#define SG_ALLOW_DIO_DEF 0
@@ -173,11 +169,11 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
/* tasklet or soft irq callback */
static void sg_rq_end_io(struct request *rq, blk_status_t status);
+/* Declarations of other static functions used before they are defined */
+static int sg_proc_init(void);
static int sg_start_req(Sg_request *srp, unsigned char *cmd);
static int sg_finish_rem_req(Sg_request * srp);
static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
-static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
- Sg_request * srp);
static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
const char __user *buf, size_t count, int blocking,
int read_only, int sg_io_owned, Sg_request **o_srp);
@@ -190,7 +186,6 @@ static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
static Sg_fd *sg_add_sfp(Sg_device * sdp);
static void sg_remove_sfp(struct kref *);
-static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
static Sg_request *sg_add_request(Sg_fd * sfp);
static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
static Sg_device *sg_get_dev(int dev);
@@ -232,16 +227,6 @@ static int sg_check_file_access(struct file *filp, const char *caller)
return 0;
}
-static int sg_allow_access(struct file *filp, unsigned char *cmd)
-{
- struct sg_fd *sfp = filp->private_data;
-
- if (sfp->parentdp->device->type == TYPE_SCANNER)
- return 0;
-
- return blk_verify_command(cmd, filp->f_mode);
-}
-
static int
open_wait(Sg_device *sdp, int flags)
{
@@ -405,200 +390,12 @@ sg_release(struct inode *inode, struct file *filp)
return 0;
}
-static ssize_t
-sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
-{
- Sg_device *sdp;
- Sg_fd *sfp;
- Sg_request *srp;
- int req_pack_id = -1;
- sg_io_hdr_t *hp;
- struct sg_header *old_hdr = NULL;
- int retval = 0;
-
- /*
- * This could cause a response to be stranded. Close the associated
- * file descriptor to free up any resources being held.
- */
- retval = sg_check_file_access(filp, __func__);
- if (retval)
- return retval;
-
- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
- return -ENXIO;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_read: count=%d\n", (int) count));
-
- if (!access_ok(buf, count))
- return -EFAULT;
- if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
- old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
- if (!old_hdr)
- return -ENOMEM;
- if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
- retval = -EFAULT;
- goto free_old_hdr;
- }
- if (old_hdr->reply_len < 0) {
- if (count >= SZ_SG_IO_HDR) {
- sg_io_hdr_t *new_hdr;
- new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
- if (!new_hdr) {
- retval = -ENOMEM;
- goto free_old_hdr;
- }
- retval =__copy_from_user
- (new_hdr, buf, SZ_SG_IO_HDR);
- req_pack_id = new_hdr->pack_id;
- kfree(new_hdr);
- if (retval) {
- retval = -EFAULT;
- goto free_old_hdr;
- }
- }
- } else
- req_pack_id = old_hdr->pack_id;
- }
- srp = sg_get_rq_mark(sfp, req_pack_id);
- if (!srp) { /* now wait on packet to arrive */
- if (atomic_read(&sdp->detaching)) {
- retval = -ENODEV;
- goto free_old_hdr;
- }
- if (filp->f_flags & O_NONBLOCK) {
- retval = -EAGAIN;
- goto free_old_hdr;
- }
- retval = wait_event_interruptible(sfp->read_wait,
- (atomic_read(&sdp->detaching) ||
- (srp = sg_get_rq_mark(sfp, req_pack_id))));
- if (atomic_read(&sdp->detaching)) {
- retval = -ENODEV;
- goto free_old_hdr;
- }
- if (retval) {
- /* -ERESTARTSYS as signal hit process */
- goto free_old_hdr;
- }
- }
- if (srp->header.interface_id != '\0') {
- retval = sg_new_read(sfp, buf, count, srp);
- goto free_old_hdr;
- }
-
- hp = &srp->header;
- if (old_hdr == NULL) {
- old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
- if (! old_hdr) {
- retval = -ENOMEM;
- goto free_old_hdr;
- }
- }
- memset(old_hdr, 0, SZ_SG_HEADER);
- old_hdr->reply_len = (int) hp->timeout;
- old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
- old_hdr->pack_id = hp->pack_id;
- old_hdr->twelve_byte =
- ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
- old_hdr->target_status = hp->masked_status;
- old_hdr->host_status = hp->host_status;
- old_hdr->driver_status = hp->driver_status;
- if ((CHECK_CONDITION & hp->masked_status) ||
- (DRIVER_SENSE & hp->driver_status))
- memcpy(old_hdr->sense_buffer, srp->sense_b,
- sizeof (old_hdr->sense_buffer));
- switch (hp->host_status) {
- /* This setup of 'result' is for backward compatibility and is best
- ignored by the user who should use target, host + driver status */
- case DID_OK:
- case DID_PASSTHROUGH:
- case DID_SOFT_ERROR:
- old_hdr->result = 0;
- break;
- case DID_NO_CONNECT:
- case DID_BUS_BUSY:
- case DID_TIME_OUT:
- old_hdr->result = EBUSY;
- break;
- case DID_BAD_TARGET:
- case DID_ABORT:
- case DID_PARITY:
- case DID_RESET:
- case DID_BAD_INTR:
- old_hdr->result = EIO;
- break;
- case DID_ERROR:
- old_hdr->result = (srp->sense_b[0] == 0 &&
- hp->masked_status == GOOD) ? 0 : EIO;
- break;
- default:
- old_hdr->result = EIO;
- break;
- }
-
- /* Now copy the result back to the user buffer. */
- if (count >= SZ_SG_HEADER) {
- if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
- retval = -EFAULT;
- goto free_old_hdr;
- }
- buf += SZ_SG_HEADER;
- if (count > old_hdr->reply_len)
- count = old_hdr->reply_len;
- if (count > SZ_SG_HEADER) {
- if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
- retval = -EFAULT;
- goto free_old_hdr;
- }
- }
- } else
- count = (old_hdr->result == 0) ? 0 : -EIO;
- sg_finish_rem_req(srp);
- sg_remove_request(sfp, srp);
- retval = count;
-free_old_hdr:
- kfree(old_hdr);
- return retval;
-}
-
-static ssize_t
-sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
-{
- sg_io_hdr_t *hp = &srp->header;
- int err = 0, err2;
- int len;
-
- if (count < SZ_SG_IO_HDR) {
- err = -EINVAL;
- goto err_out;
- }
- hp->sb_len_wr = 0;
- if ((hp->mx_sb_len > 0) && hp->sbp) {
- if ((CHECK_CONDITION & hp->masked_status) ||
- (DRIVER_SENSE & hp->driver_status)) {
- int sb_len = SCSI_SENSE_BUFFERSIZE;
- sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
- len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
- len = (len > sb_len) ? sb_len : len;
- if (copy_to_user(hp->sbp, srp->sense_b, len)) {
- err = -EFAULT;
- goto err_out;
- }
- hp->sb_len_wr = len;
- }
- }
- if (hp->masked_status || hp->host_status || hp->driver_status)
- hp->info |= SG_INFO_CHECK;
- if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
- err = -EFAULT;
- goto err_out;
- }
-err_out:
- err2 = sg_finish_rem_req(srp);
- sg_remove_request(sfp, srp);
- return err ? : err2 ? : count;
-}
-
+/*
+ * write(2) related functions follow. They are shown before read(2) related
+ * functions. That is because SCSI commands/requests are first "written" to
+ * the SCSI device by using write(2), ioctl(SG_IOSUBMIT) or the first half
+ * of the synchronous ioctl(SG_IO) system call.
+ */
static ssize_t
sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
{
@@ -710,6 +507,16 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
return (k < 0) ? k : count;
}
+static int sg_allow_access(struct file *filp, unsigned char *cmd)
+{
+ struct sg_fd *sfp = filp->private_data;
+
+ if (sfp->parentdp->device->type == TYPE_SCANNER)
+ return 0;
+
+ return blk_verify_command(cmd, filp->f_mode);
+}
+
static ssize_t
sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
size_t count, int blocking, int read_only, int sg_io_owned,
@@ -840,6 +647,74 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
return 0;
}
+
+/*
+ * read(2) related functions follow. They are shown after write(2) related
+ * functions. Apart from read(2) itself, ioctl(SG_IORECEIVE) and the second
+ * half of the ioctl(SG_IO) share code with read(2).
+ */
+
+static Sg_request *
+sg_get_rq_mark(Sg_fd *sfp, int pack_id)
+{
+ Sg_request *resp;
+ unsigned long iflags;
+
+ write_lock_irqsave(&sfp->rq_list_lock, iflags);
+ list_for_each_entry(resp, &sfp->rq_list, entry) {
+ /* look for requests that are ready + not SG_IO owned */
+ if ((resp->done == 1) && (!resp->sg_io_owned) &&
+ ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
+ resp->done = 2; /* guard against other readers */
+ write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ return resp;
+ }
+ }
+ write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ return NULL;
+}
+
+static ssize_t
+sg_new_read(Sg_fd *sfp, char __user *buf, size_t count, Sg_request *srp)
+{
+ sg_io_hdr_t *hp = &srp->header;
+ int err = 0, err2;
+ int len;
+
+ if (count < SZ_SG_IO_HDR) {
+ err = -EINVAL;
+ goto err_out;
+ }
+ hp->sb_len_wr = 0;
+ if ((hp->mx_sb_len > 0) && hp->sbp) {
+ if ((CHECK_CONDITION & hp->masked_status) ||
+ (DRIVER_SENSE & hp->driver_status)) {
+ int sb_len = SCSI_SENSE_BUFFERSIZE;
+
+ sb_len = (hp->mx_sb_len > sb_len) ? sb_len :
+ hp->mx_sb_len;
+ /* Additional sense length field */
+ len = 8 + (int) srp->sense_b[7];
+ len = (len > sb_len) ? sb_len : len;
+ if (copy_to_user(hp->sbp, srp->sense_b, len)) {
+ err = -EFAULT;
+ goto err_out;
+ }
+ hp->sb_len_wr = len;
+ }
+ }
+ if (hp->masked_status || hp->host_status || hp->driver_status)
+ hp->info |= SG_INFO_CHECK;
+ if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
+ err = -EFAULT;
+ goto err_out;
+ }
+err_out:
+ err2 = sg_finish_rem_req(srp);
+ sg_remove_request(sfp, srp);
+ return err ? : err2 ? : count;
+}
+
static int srp_done(Sg_fd *sfp, Sg_request *srp)
{
unsigned long flags;
@@ -851,6 +726,168 @@ static int srp_done(Sg_fd *sfp, Sg_request *srp)
return ret;
}
+static ssize_t
+sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
+{
+ Sg_device *sdp;
+ Sg_fd *sfp;
+ Sg_request *srp;
+ int req_pack_id = -1;
+ sg_io_hdr_t *hp;
+ struct sg_header *old_hdr = NULL;
+ int retval = 0;
+
+ /*
+ * This could cause a response to be stranded. Close the associated
+ * file descriptor to free up any resources being held.
+ */
+ retval = sg_check_file_access(filp, __func__);
+ if (retval)
+ return retval;
+
+ sfp = filp->private_data;
+ sdp = sfp->parentdp;
+ SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
+ "%s: count=%d\n", __func__,
+ (int) count));
+ if (!sdp)
+ return -ENXIO;
+
+ if (!access_ok(buf, count))
+ return -EFAULT;
+ if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
+ old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
+ if (!old_hdr)
+ return -ENOMEM;
+ if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
+ retval = -EFAULT;
+ goto free_old_hdr;
+ }
+ if (old_hdr->reply_len < 0) {
+ if (count >= SZ_SG_IO_HDR) {
+ sg_io_hdr_t *new_hdr;
+
+ new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
+ if (!new_hdr) {
+ retval = -ENOMEM;
+ goto free_old_hdr;
+ }
+ retval = __copy_from_user
+ (new_hdr, buf, SZ_SG_IO_HDR);
+ req_pack_id = new_hdr->pack_id;
+ kfree(new_hdr);
+ if (retval) {
+ retval = -EFAULT;
+ goto free_old_hdr;
+ }
+ }
+ } else
+ req_pack_id = old_hdr->pack_id;
+ }
+ srp = sg_get_rq_mark(sfp, req_pack_id);
+ if (!srp) { /* now wait on packet to arrive */
+ if (atomic_read(&sdp->detaching)) {
+ retval = -ENODEV;
+ goto free_old_hdr;
+ }
+ if (filp->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto free_old_hdr;
+ }
+ retval = wait_event_interruptible(sfp->read_wait,
+ (atomic_read(&sdp->detaching) ||
+ (srp = sg_get_rq_mark(sfp, req_pack_id))));
+ if (atomic_read(&sdp->detaching)) {
+ retval = -ENODEV;
+ goto free_old_hdr;
+ }
+ if (retval) {
+ /* -ERESTARTSYS as signal hit process */
+ goto free_old_hdr;
+ }
+ }
+ if (srp->header.interface_id != '\0') {
+ retval = sg_new_read(sfp, buf, count, srp);
+ goto free_old_hdr;
+ }
+
+ hp = &srp->header;
+ if (old_hdr == NULL) {
+ old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
+ if (!old_hdr) {
+ retval = -ENOMEM;
+ goto free_old_hdr;
+ }
+ }
+ memset(old_hdr, 0, SZ_SG_HEADER);
+ old_hdr->reply_len = (int) hp->timeout;
+ old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
+ old_hdr->pack_id = hp->pack_id;
+ old_hdr->twelve_byte =
+ ((srp->data.cmd_opcode >= 0xc0) && (hp->cmd_len == 12)) ? 1 : 0;
+ old_hdr->target_status = hp->masked_status;
+ old_hdr->host_status = hp->host_status;
+ old_hdr->driver_status = hp->driver_status;
+ if ((hp->masked_status & CHECK_CONDITION) ||
+ (hp->driver_status & DRIVER_SENSE))
+ memcpy(old_hdr->sense_buffer, srp->sense_b,
+ sizeof(old_hdr->sense_buffer));
+ switch (hp->host_status) {
+ /*
+ * This setup of 'result' is for backward compatibility and is best
+ * ignored by the user who should use target, host + driver status
+ */
+ case DID_OK:
+ case DID_PASSTHROUGH:
+ case DID_SOFT_ERROR:
+ old_hdr->result = 0;
+ break;
+ case DID_NO_CONNECT:
+ case DID_BUS_BUSY:
+ case DID_TIME_OUT:
+ old_hdr->result = EBUSY;
+ break;
+ case DID_BAD_TARGET:
+ case DID_ABORT:
+ case DID_PARITY:
+ case DID_RESET:
+ case DID_BAD_INTR:
+ old_hdr->result = EIO;
+ break;
+ case DID_ERROR:
+ old_hdr->result = (srp->sense_b[0] == 0 &&
+ hp->masked_status == GOOD) ? 0 : EIO;
+ break;
+ default:
+ old_hdr->result = EIO;
+ break;
+ }
+
+ /* Now copy the result back to the user buffer. */
+ if (count >= SZ_SG_HEADER) {
+ if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
+ retval = -EFAULT;
+ goto free_old_hdr;
+ }
+ buf += SZ_SG_HEADER;
+ if (count > old_hdr->reply_len)
+ count = old_hdr->reply_len;
+ if (count > SZ_SG_HEADER) {
+ if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
+ retval = -EFAULT;
+ goto free_old_hdr;
+ }
+ }
+ } else
+ count = (old_hdr->result == 0) ? 0 : -EIO;
+ sg_finish_rem_req(srp);
+ sg_remove_request(sfp, srp);
+ retval = count;
+free_old_hdr:
+ kfree(old_hdr);
+ return retval;
+}
+
static int max_sectors_bytes(struct request_queue *q)
{
unsigned int max_sectors = queue_max_sectors(q);
@@ -1669,9 +1706,7 @@ init_sg(void)
sg_sysfs_valid = 1;
rc = scsi_register_interface(&sg_interface);
if (0 == rc) {
-#ifdef CONFIG_SCSI_PROC_FS
sg_proc_init();
-#endif /* CONFIG_SCSI_PROC_FS */
return 0;
}
class_destroy(sg_sysfs_class);
@@ -1680,6 +1715,14 @@ init_sg(void)
return rc;
}
+#ifndef CONFIG_SCSI_PROC_FS
+static int
+sg_proc_init(void)
+{
+ return 0;
+}
+#endif
+
static void __exit
exit_sg(void)
{
@@ -2069,26 +2112,6 @@ sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
sfp->res_in_use = 0;
}
-static Sg_request *
-sg_get_rq_mark(Sg_fd * sfp, int pack_id)
-{
- Sg_request *resp;
- unsigned long iflags;
-
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
- list_for_each_entry(resp, &sfp->rq_list, entry) {
- /* look for requests that are ready + not SG_IO owned */
- if ((1 == resp->done) && (!resp->sg_io_owned) &&
- ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
- resp->done = 2; /* guard against other readers */
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return resp;
- }
- }
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return NULL;
-}
-
/* always adds to end of list */
static Sg_request *
sg_add_request(Sg_fd * sfp)
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 02/23] sg: remove typedefs, type+formatting cleanup
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 01/23] sg: move functions around Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 03/23] sg: sg_log and is_enabled Douglas Gilbert
` (20 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi
Cc: martin.petersen, jejb, hare, Johannes Thumshirn,
Christoph Hellwig, Hannes Reinecke
Typedefs for structure types are discouraged so those structures
that are private to the driver have had their typedefs removed.
This also means that most "camel" type variable names (i.e. mixed
case) have been removed.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 394 ++++++++++++++++++++++++++--------------------
1 file changed, 219 insertions(+), 175 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 9f1587761d86..6615777931f7 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -3,7 +3,7 @@
* History:
* Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
* to allow user process control of SCSI devices.
- * Development Sponsored by Killy Corp. NY NY
+ * Development Sponsored by Killy Corp. NY NY [1992 ??]
*
* Original driver (sg.c):
* Copyright (C) 1992 Lawrence Foard
@@ -15,13 +15,6 @@ static int sg_version_num = 30901; /* [x]xyyzz where [x] empty when x=0 */
#define SG_VERSION_STR "3.9.01" /* [x]x.[y]y.zz */
static char *sg_version_date = "20190606";
-/*
- * D. P. Gilbert (dgilbert@interlog.com), notes:
- * - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
- * the kernel/module needs to be built with CONFIG_SCSI_LOGGING
- * (otherwise the macros compile to empty statements).
- *
- */
#include <linux/module.h>
#include <linux/fs.h>
@@ -91,33 +84,32 @@ static int sg_add_device(struct device *, struct class_interface *);
static void sg_remove_device(struct device *, struct class_interface *);
static DEFINE_IDR(sg_index_idr);
-static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
- file descriptor list for device */
+static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock fd list for device */
static struct class_interface sg_interface = {
.add_dev = sg_add_device,
.remove_dev = sg_remove_device,
};
-typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
- unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
- unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
- unsigned bufflen; /* Size of (aggregate) data buffer */
+struct sg_scatter_hold { /* holding area for scsi scatter gather info */
+ u16 k_use_sg; /* Count of kernel scatter-gather pieces */
+ unsigned int sglist_len; /* size of malloc'd scatter-gather list ++ */
+ unsigned int bufflen; /* Size of (aggregate) data buffer */
struct page **pages;
int page_order;
char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
- unsigned char cmd_opcode; /* first byte of command */
-} Sg_scatter_hold;
+ u8 cmd_opcode; /* first byte of command */
+};
struct sg_device; /* forward declarations */
struct sg_fd;
-typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
+struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
struct list_head entry; /* list entry */
struct sg_fd *parentfp; /* NULL -> not in use */
- Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
+ struct sg_scatter_hold data; /* hold buffer, perhaps scatter list */
sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
- unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
+ u8 sense_b[SCSI_SENSE_BUFFERSIZE];
char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
char orphan; /* 1 -> drop on sight, 0 -> normal */
char sg_io_owned; /* 1 -> packet belongs to SG_IO */
@@ -126,9 +118,9 @@ typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
struct request *rq;
struct bio *bio;
struct execute_work ew;
-} Sg_request;
+};
-typedef struct sg_fd { /* holds the state of a file descriptor */
+struct sg_fd { /* holds the state of a file descriptor */
struct list_head sfd_siblings; /* protected by device's sfd_lock */
struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */
@@ -136,21 +128,21 @@ typedef struct sg_fd { /* holds the state of a file descriptor */
struct mutex f_mutex; /* protect against changes in this fd */
int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
- Sg_scatter_hold reserve; /* buffer held for this file descriptor */
+ struct sg_scatter_hold reserve; /* buffer for this file descriptor */
struct list_head rq_list; /* head of request list */
struct fasync_struct *async_qp; /* used by asynchronous notification */
- Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
+ struct sg_request req_arr[SG_MAX_QUEUE];/* use as singly-linked list */
char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
- unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
+ u8 next_cmd_len; /* 0: automatic, >0: use on next write() */
char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
char mmap_called; /* 0 -> mmap() never called on this fd */
char res_in_use; /* 1 -> 'reserve' array in use */
struct kref f_ref;
struct execute_work ew;
-} Sg_fd;
+};
-typedef struct sg_device { /* holds the state of each scsi generic device */
+struct sg_device { /* holds the state of each scsi generic device */
struct scsi_device *device;
wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
struct mutex open_rel_lock; /* held when in open() or release() */
@@ -165,30 +157,34 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
struct gendisk *disk;
struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
struct kref d_ref;
-} Sg_device;
+};
/* tasklet or soft irq callback */
static void sg_rq_end_io(struct request *rq, blk_status_t status);
/* Declarations of other static functions used before they are defined */
static int sg_proc_init(void);
-static int sg_start_req(Sg_request *srp, unsigned char *cmd);
-static int sg_finish_rem_req(Sg_request * srp);
-static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
-static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
+static int sg_start_req(struct sg_request *srp, u8 *cmd);
+static int sg_finish_rem_req(struct sg_request *srp);
+static int sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
+ int buff_size);
+static ssize_t sg_new_write(struct sg_fd *sfp, struct file *file,
const char __user *buf, size_t count, int blocking,
- int read_only, int sg_io_owned, Sg_request **o_srp);
-static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
- unsigned char *cmnd, int timeout, int blocking);
-static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
-static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
-static void sg_build_reserve(Sg_fd * sfp, int req_size);
-static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
-static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
-static Sg_fd *sg_add_sfp(Sg_device * sdp);
+ int read_only, int sg_io_owned,
+ struct sg_request **o_srp);
+static int sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
+ u8 *cmnd, int timeout, int blocking);
+static int sg_read_oxfer(struct sg_request *srp, char __user *outp,
+ int num_read_xfer);
+static void sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
+static void sg_build_reserve(struct sg_fd *sfp, int req_size);
+static void sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp,
+ int size);
+static void sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp);
+static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
static void sg_remove_sfp(struct kref *);
-static Sg_request *sg_add_request(Sg_fd * sfp);
-static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
-static Sg_device *sg_get_dev(int dev);
+static struct sg_request *sg_add_request(struct sg_fd *sfp);
+static int sg_remove_request(struct sg_fd *sfp, struct sg_request *srp);
+static struct sg_device *sg_get_dev(int dev);
static void sg_device_destroy(struct kref *kref);
#define SZ_SG_HEADER sizeof(struct sg_header)
@@ -212,7 +208,8 @@ static void sg_device_destroy(struct kref *kref);
* This function provides protection for the legacy API by restricting the
* calling context.
*/
-static int sg_check_file_access(struct file *filp, const char *caller)
+static int
+sg_check_file_access(struct file *filp, const char *caller)
{
if (filp->f_cred != current_real_cred()) {
pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
@@ -228,11 +225,11 @@ static int sg_check_file_access(struct file *filp, const char *caller)
}
static int
-open_wait(Sg_device *sdp, int flags)
+sg_wait_open_event(struct sg_device *sdp, bool o_excl)
{
int retval = 0;
- if (flags & O_EXCL) {
+ if (o_excl) {
while (sdp->open_cnt > 0) {
mutex_unlock(&sdp->open_rel_lock);
retval = wait_event_interruptible(sdp->open_wait,
@@ -263,26 +260,34 @@ open_wait(Sg_device *sdp, int flags)
return retval;
}
-/* Returns 0 on success, else a negated errno value */
+/*
+ * Corresponds to the open() system call on sg devices. Implements O_EXCL on
+ * a per device basis using 'open_cnt'. If O_EXCL and O_NONBLOCK and there is
+ * already a sg handle open on this device then it fails with an errno of
+ * EBUSY. Without the O_NONBLOCK flag then this thread enters an interruptible
+ * wait until the other handle(s) are closed.
+ */
static int
sg_open(struct inode *inode, struct file *filp)
{
- int dev = iminor(inode);
- int flags = filp->f_flags;
+ bool o_excl;
+ int min_dev = iminor(inode);
+ int op_flags = filp->f_flags;
struct request_queue *q;
- Sg_device *sdp;
- Sg_fd *sfp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
int retval;
nonseekable_open(inode, filp);
- if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
+ o_excl = !!(op_flags & O_EXCL);
+ if (o_excl && ((op_flags & O_ACCMODE) == O_RDONLY))
return -EPERM; /* Can't lock it with read only access */
- sdp = sg_get_dev(dev);
+ sdp = sg_get_dev(min_dev);
if (IS_ERR(sdp))
return PTR_ERR(sdp);
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_open: flags=0x%x\n", flags));
+ "sg_open: flags=0x%x\n", op_flags));
/* This driver's module count bumped by fops_get in <linux/fs.h> */
/* Prevent the device driver from vanishing while we sleep */
@@ -297,7 +302,7 @@ sg_open(struct inode *inode, struct file *filp)
/* scsi_block_when_processing_errors() may block so bypass
* check if O_NONBLOCK. Permits SCSI commands to be issued
* during error recovery. Tread carefully. */
- if (!((flags & O_NONBLOCK) ||
+ if (!((op_flags & O_NONBLOCK) ||
scsi_block_when_processing_errors(sdp->device))) {
retval = -ENXIO;
/* we are in error recovery for this device */
@@ -305,8 +310,8 @@ sg_open(struct inode *inode, struct file *filp)
}
mutex_lock(&sdp->open_rel_lock);
- if (flags & O_NONBLOCK) {
- if (flags & O_EXCL) {
+ if (op_flags & O_NONBLOCK) {
+ if (o_excl) {
if (sdp->open_cnt > 0) {
retval = -EBUSY;
goto error_mutex_locked;
@@ -318,13 +323,13 @@ sg_open(struct inode *inode, struct file *filp)
}
}
} else {
- retval = open_wait(sdp, flags);
+ retval = sg_wait_open_event(sdp, o_excl);
if (retval) /* -ERESTARTSYS or -ENODEV */
goto error_mutex_locked;
}
/* N.B. at this point we are holding the open_rel_lock */
- if (flags & O_EXCL)
+ if (o_excl)
sdp->exclude = true;
if (sdp->open_cnt < 1) { /* no existing opens */
@@ -348,7 +353,7 @@ sg_open(struct inode *inode, struct file *filp)
return retval;
out_undo:
- if (flags & O_EXCL) {
+ if (o_excl) {
sdp->exclude = false; /* undo if error */
wake_up_interruptible(&sdp->open_wait);
}
@@ -366,10 +371,12 @@ sg_open(struct inode *inode, struct file *filp)
static int
sg_release(struct inode *inode, struct file *filp)
{
- Sg_device *sdp;
- Sg_fd *sfp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
+ sfp = filp->private_data;
+ sdp = sfp->parentdp;
+ if (!sdp)
return -ENXIO;
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
@@ -401,20 +408,22 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
{
int mxsize, cmd_size, k;
int input_size, blocking;
- unsigned char opcode;
- Sg_device *sdp;
- Sg_fd *sfp;
- Sg_request *srp;
+ u8 opcode;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
+ struct sg_request *srp;
struct sg_header old_hdr;
sg_io_hdr_t *hp;
- unsigned char cmnd[SG_MAX_CDB_SIZE];
+ u8 cmnd[SG_MAX_CDB_SIZE];
int retval;
retval = sg_check_file_access(filp, __func__);
if (retval)
return retval;
- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
+ sfp = filp->private_data;
+ sdp = sfp->parentdp;
+ if (!sdp)
return -ENXIO;
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
"sg_write: count=%d\n", (int) count));
@@ -467,7 +476,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
}
hp = &srp->header;
hp->interface_id = '\0'; /* indicator of old interface tunnelled */
- hp->cmd_len = (unsigned char) cmd_size;
+ hp->cmd_len = (u8) cmd_size;
hp->iovec_count = 0;
hp->mx_sb_len = 0;
if (input_size > 0)
@@ -507,7 +516,8 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
return (k < 0) ? k : count;
}
-static int sg_allow_access(struct file *filp, unsigned char *cmd)
+static int
+sg_allow_access(struct file *filp, u8 *cmd)
{
struct sg_fd *sfp = filp->private_data;
@@ -518,14 +528,14 @@ static int sg_allow_access(struct file *filp, unsigned char *cmd)
}
static ssize_t
-sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
+sg_new_write(struct sg_fd *sfp, struct file *file, const char __user *buf,
size_t count, int blocking, int read_only, int sg_io_owned,
- Sg_request **o_srp)
+ struct sg_request **o_srp)
{
int k;
- Sg_request *srp;
+ struct sg_request *srp;
sg_io_hdr_t *hp;
- unsigned char cmnd[SG_MAX_CDB_SIZE];
+ u8 cmnd[SG_MAX_CDB_SIZE];
int timeout;
unsigned long ul_timeout;
@@ -591,11 +601,11 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
}
static int
-sg_common_write(Sg_fd * sfp, Sg_request * srp,
- unsigned char *cmnd, int timeout, int blocking)
+sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
+ u8 *cmnd, int timeout, int blocking)
{
int k, at_head;
- Sg_device *sdp = sfp->parentdp;
+ struct sg_device *sdp = sfp->parentdp;
sg_io_hdr_t *hp = &srp->header;
srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
@@ -654,10 +664,10 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
* half of the ioctl(SG_IO) share code with read(2).
*/
-static Sg_request *
-sg_get_rq_mark(Sg_fd *sfp, int pack_id)
+static struct sg_request *
+sg_get_rq_mark(struct sg_fd *sfp, int pack_id)
{
- Sg_request *resp;
+ struct sg_request *resp;
unsigned long iflags;
write_lock_irqsave(&sfp->rq_list_lock, iflags);
@@ -675,7 +685,8 @@ sg_get_rq_mark(Sg_fd *sfp, int pack_id)
}
static ssize_t
-sg_new_read(Sg_fd *sfp, char __user *buf, size_t count, Sg_request *srp)
+sg_new_read(struct sg_fd *sfp, char __user *buf, size_t count,
+ struct sg_request *srp)
{
sg_io_hdr_t *hp = &srp->header;
int err = 0, err2;
@@ -715,7 +726,8 @@ sg_new_read(Sg_fd *sfp, char __user *buf, size_t count, Sg_request *srp)
return err ? : err2 ? : count;
}
-static int srp_done(Sg_fd *sfp, Sg_request *srp)
+static int
+srp_done(struct sg_fd *sfp, struct sg_request *srp)
{
unsigned long flags;
int ret;
@@ -729,9 +741,9 @@ static int srp_done(Sg_fd *sfp, Sg_request *srp)
static ssize_t
sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
{
- Sg_device *sdp;
- Sg_fd *sfp;
- Sg_request *srp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
+ struct sg_request *srp;
int req_pack_id = -1;
sg_io_hdr_t *hp;
struct sg_header *old_hdr = NULL;
@@ -888,7 +900,8 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
return retval;
}
-static int max_sectors_bytes(struct request_queue *q)
+static int
+max_sectors_bytes(struct request_queue *q)
{
unsigned int max_sectors = queue_max_sectors(q);
@@ -898,9 +911,9 @@ static int max_sectors_bytes(struct request_queue *q)
}
static void
-sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
+sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
{
- Sg_request *srp;
+ struct sg_request *srp;
int val;
unsigned int ms;
@@ -936,14 +949,15 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
void __user *p = (void __user *)arg;
int __user *ip = p;
int result, val, read_only;
- Sg_device *sdp;
- Sg_fd *sfp;
- Sg_request *srp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
+ struct sg_request *srp;
unsigned long iflags;
- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
+ sfp = filp->private_data;
+ sdp = sfp->parentdp;
+ if (!sdp)
return -ENXIO;
-
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
"sg_ioctl: cmd=0x%x\n", (int) cmd_in));
read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
@@ -1178,13 +1192,16 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
}
#ifdef CONFIG_COMPAT
-static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
+static long
+sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
- Sg_device *sdp;
- Sg_fd *sfp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
struct scsi_device *sdev;
- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
+ sfp = filp->private_data;
+ sdp = sfp->parentdp;
+ if (!sdp)
return -ENXIO;
sdev = sdp->device;
@@ -1204,9 +1221,9 @@ static __poll_t
sg_poll(struct file *filp, poll_table * wait)
{
__poll_t res = 0;
- Sg_device *sdp;
- Sg_fd *sfp;
- Sg_request *srp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
+ struct sg_request *srp;
int count = 0;
unsigned long iflags;
@@ -1241,10 +1258,12 @@ sg_poll(struct file *filp, poll_table * wait)
static int
sg_fasync(int fd, struct file *filp, int mode)
{
- Sg_device *sdp;
- Sg_fd *sfp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
+ sfp = filp->private_data;
+ sdp = sfp->parentdp;
+ if (!sdp)
return -ENXIO;
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
"sg_fasync: mode=%d\n", mode));
@@ -1256,13 +1275,21 @@ static vm_fault_t
sg_vma_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
- Sg_fd *sfp;
+ struct sg_fd *sfp;
unsigned long offset, len, sa;
- Sg_scatter_hold *rsv_schp;
+ struct sg_scatter_hold *rsv_schp;
int k, length;
+ const char *nbp = "==NULL, bad";
- if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
- return VM_FAULT_SIGBUS;
+ if (!vma) {
+ pr_warn("%s: vma%s\n", __func__, nbp);
+ goto out_err;
+ }
+ sfp = vma->vm_private_data;
+ if (!sfp) {
+ pr_warn("%s: sfp%s\n", __func__, nbp);
+ goto out_err;
+ }
rsv_schp = &sfp->reserve;
offset = vmf->pgoff << PAGE_SHIFT;
if (offset >= rsv_schp->bufflen)
@@ -1285,7 +1312,7 @@ sg_vma_fault(struct vm_fault *vmf)
sa += len;
offset -= len;
}
-
+out_err:
return VM_FAULT_SIGBUS;
}
@@ -1296,14 +1323,19 @@ static const struct vm_operations_struct sg_mmap_vm_ops = {
static int
sg_mmap(struct file *filp, struct vm_area_struct *vma)
{
- Sg_fd *sfp;
+ struct sg_fd *sfp;
unsigned long req_sz, len, sa;
- Sg_scatter_hold *rsv_schp;
+ struct sg_scatter_hold *rsv_schp;
int k, length;
int ret = 0;
- if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
+ if (!filp || !vma)
+ return -ENXIO;
+ sfp = filp->private_data;
+ if (!sfp) {
+ pr_warn("sg: %s: sfp is NULL\n", __func__);
return -ENXIO;
+ }
req_sz = vma->vm_end - vma->vm_start;
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
"sg_mmap starting, vm_start=%p, len=%d\n",
@@ -1354,8 +1386,8 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
{
struct sg_request *srp = rq->end_io_data;
struct scsi_request *req = scsi_req(rq);
- Sg_device *sdp;
- Sg_fd *sfp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
unsigned long iflags;
unsigned int ms;
char *sense;
@@ -1467,21 +1499,18 @@ static struct class *sg_sysfs_class;
static int sg_sysfs_valid = 0;
-static Sg_device *
+static struct sg_device *
sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
{
struct request_queue *q = scsidp->request_queue;
- Sg_device *sdp;
+ struct sg_device *sdp;
unsigned long iflags;
int error;
u32 k;
- sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
- if (!sdp) {
- sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
- "failure\n", __func__);
+ sdp = kzalloc(sizeof(struct sg_device), GFP_KERNEL);
+ if (!sdp)
return ERR_PTR(-ENOMEM);
- }
idr_preload(GFP_KERNEL);
write_lock_irqsave(&sg_index_lock, iflags);
@@ -1494,8 +1523,8 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
scsidp->type, SG_MAX_DEVS - 1);
error = -ENODEV;
} else {
- sdev_printk(KERN_WARNING, scsidp, "%s: idr "
- "allocation Sg_device failure: %d\n",
+ sdev_printk(KERN_WARNING, scsidp,
+ "%s: idr alloc sg_device failure: %d\n",
__func__, error);
}
goto out_unlock;
@@ -1534,7 +1563,7 @@ sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
{
struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
struct gendisk *disk;
- Sg_device *sdp = NULL;
+ struct sg_device *sdp = NULL;
struct cdev * cdev = NULL;
int error;
unsigned long iflags;
@@ -1633,9 +1662,9 @@ static void
sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
{
struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
- Sg_device *sdp = dev_get_drvdata(cl_dev);
+ struct sg_device *sdp = dev_get_drvdata(cl_dev);
unsigned long iflags;
- Sg_fd *sfp;
+ struct sg_fd *sfp;
int val;
if (!sdp)
@@ -1738,22 +1767,22 @@ exit_sg(void)
}
static int
-sg_start_req(Sg_request *srp, unsigned char *cmd)
+sg_start_req(struct sg_request *srp, u8 *cmd)
{
int res;
struct request *rq;
struct scsi_request *req;
- Sg_fd *sfp = srp->parentfp;
+ struct sg_fd *sfp = srp->parentfp;
sg_io_hdr_t *hp = &srp->header;
int dxfer_len = (int) hp->dxfer_len;
int dxfer_dir = hp->dxfer_direction;
unsigned int iov_count = hp->iovec_count;
- Sg_scatter_hold *req_schp = &srp->data;
- Sg_scatter_hold *rsv_schp = &sfp->reserve;
+ struct sg_scatter_hold *req_schp = &srp->data;
+ struct sg_scatter_hold *rsv_schp = &sfp->reserve;
struct request_queue *q = sfp->parentdp->device->request_queue;
struct rq_map_data *md, map_data;
int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
- unsigned char *long_cmdp = NULL;
+ u8 *long_cmdp = NULL;
SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
"sg_start_req: dxfer_len=%d\n",
@@ -1868,12 +1897,12 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
}
static int
-sg_finish_rem_req(Sg_request *srp)
+sg_finish_rem_req(struct sg_request *srp)
{
int ret = 0;
- Sg_fd *sfp = srp->parentfp;
- Sg_scatter_hold *req_schp = &srp->data;
+ struct sg_fd *sfp = srp->parentfp;
+ struct sg_scatter_hold *req_schp = &srp->data;
SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
"sg_finish_rem_req: res_used=%d\n",
@@ -1895,7 +1924,8 @@ sg_finish_rem_req(Sg_request *srp)
}
static int
-sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
+sg_build_sgat(struct sg_scatter_hold *schp, const struct sg_fd *sfp,
+ int tablesize)
{
int sg_bufflen = tablesize * sizeof(struct page *);
gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
@@ -1908,7 +1938,8 @@ sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
}
static int
-sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
+sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
+ int buff_size)
{
int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
int sg_tablesize = sfp->parentdp->sg_tablesize;
@@ -1990,7 +2021,7 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
}
static void
-sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
+sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
{
SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
"sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
@@ -2013,9 +2044,9 @@ sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
}
static int
-sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
+sg_read_oxfer(struct sg_request *srp, char __user *outp, int num_read_xfer)
{
- Sg_scatter_hold *schp = &srp->data;
+ struct sg_scatter_hold *schp = &srp->data;
int k, num;
SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
@@ -2046,9 +2077,9 @@ sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
}
static void
-sg_build_reserve(Sg_fd * sfp, int req_size)
+sg_build_reserve(struct sg_fd *sfp, int req_size)
{
- Sg_scatter_hold *schp = &sfp->reserve;
+ struct sg_scatter_hold *schp = &sfp->reserve;
SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
"sg_build_reserve: req_size=%d\n", req_size));
@@ -2064,10 +2095,10 @@ sg_build_reserve(Sg_fd * sfp, int req_size)
}
static void
-sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
+sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp, int size)
{
- Sg_scatter_hold *req_schp = &srp->data;
- Sg_scatter_hold *rsv_schp = &sfp->reserve;
+ struct sg_scatter_hold *req_schp = &srp->data;
+ struct sg_scatter_hold *rsv_schp = &sfp->reserve;
int k, num, rem;
srp->res_used = 1;
@@ -2095,9 +2126,9 @@ sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
}
static void
-sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
+sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp)
{
- Sg_scatter_hold *req_schp = &srp->data;
+ struct sg_scatter_hold *req_schp = &srp->data;
SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
"sg_unlink_reserve: req->k_use_sg=%d\n",
@@ -2113,12 +2144,12 @@ sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
}
/* always adds to end of list */
-static Sg_request *
-sg_add_request(Sg_fd * sfp)
+static struct sg_request *
+sg_add_request(struct sg_fd *sfp)
{
int k;
unsigned long iflags;
- Sg_request *rp = sfp->req_arr;
+ struct sg_request *rp = sfp->req_arr;
write_lock_irqsave(&sfp->rq_list_lock, iflags);
if (!list_empty(&sfp->rq_list)) {
@@ -2132,7 +2163,7 @@ sg_add_request(Sg_fd * sfp)
if (k >= SG_MAX_QUEUE)
goto out_unlock;
}
- memset(rp, 0, sizeof (Sg_request));
+ memset(rp, 0, sizeof(struct sg_request));
rp->parentfp = sfp;
rp->header.duration = jiffies_to_msecs(jiffies);
list_add_tail(&rp->entry, &sfp->rq_list);
@@ -2145,7 +2176,7 @@ sg_add_request(Sg_fd * sfp)
/* Return of 1 for found; 0 for not found */
static int
-sg_remove_request(Sg_fd * sfp, Sg_request * srp)
+sg_remove_request(struct sg_fd *sfp, struct sg_request *srp)
{
unsigned long iflags;
int res = 0;
@@ -2162,10 +2193,10 @@ sg_remove_request(Sg_fd * sfp, Sg_request * srp)
return res;
}
-static Sg_fd *
-sg_add_sfp(Sg_device * sdp)
+static struct sg_fd *
+sg_add_sfp(struct sg_device *sdp)
{
- Sg_fd *sfp;
+ struct sg_fd *sfp;
unsigned long iflags;
int bufflen;
@@ -2215,13 +2246,13 @@ sg_remove_sfp_usercontext(struct work_struct *work)
{
struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
struct sg_device *sdp = sfp->parentdp;
- Sg_request *srp;
+ struct sg_request *srp;
unsigned long iflags;
/* Cleanup any responses which were never read(). */
write_lock_irqsave(&sfp->rq_list_lock, iflags);
while (!list_empty(&sfp->rq_list)) {
- srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
+ srp = list_first_entry(&sfp->rq_list, struct sg_request, entry);
sg_finish_rem_req(srp);
list_del(&srp->entry);
srp->parentfp = NULL;
@@ -2286,12 +2317,13 @@ sg_last_dev(void)
#endif
/* must be called with sg_index_lock held */
-static Sg_device *sg_lookup_dev(int dev)
+static struct sg_device *
+sg_lookup_dev(int dev)
{
return idr_find(&sg_index_idr, dev);
}
-static Sg_device *
+static struct sg_device *
sg_get_dev(int dev)
{
struct sg_device *sdp;
@@ -2389,13 +2421,15 @@ sg_proc_init(void)
}
-static int sg_proc_seq_show_int(struct seq_file *s, void *v)
+static int
+sg_proc_seq_show_int(struct seq_file *s, void *v)
{
seq_printf(s, "%d\n", *((int *)s->private));
return 0;
}
-static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
+static int
+sg_proc_single_open_adio(struct inode *inode, struct file *file)
{
return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
}
@@ -2416,7 +2450,8 @@ sg_proc_write_adio(struct file *filp, const char __user *buffer,
return count;
}
-static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
+static int
+sg_proc_single_open_dressz(struct inode *inode, struct file *file)
{
return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
}
@@ -2441,14 +2476,16 @@ sg_proc_write_dressz(struct file *filp, const char __user *buffer,
return -ERANGE;
}
-static int sg_proc_seq_show_version(struct seq_file *s, void *v)
+static int
+sg_proc_seq_show_version(struct seq_file *s, void *v)
{
seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
sg_version_date);
return 0;
}
-static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
+static int
+sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
{
seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
return 0;
@@ -2459,7 +2496,8 @@ struct sg_proc_deviter {
size_t max;
};
-static void * dev_seq_start(struct seq_file *s, loff_t *pos)
+static void *
+dev_seq_start(struct seq_file *s, loff_t *pos)
{
struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
@@ -2474,7 +2512,8 @@ static void * dev_seq_start(struct seq_file *s, loff_t *pos)
return it;
}
-static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
+static void *
+dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct sg_proc_deviter * it = s->private;
@@ -2482,15 +2521,17 @@ static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
return (it->index < it->max) ? it : NULL;
}
-static void dev_seq_stop(struct seq_file *s, void *v)
+static void
+dev_seq_stop(struct seq_file *s, void *v)
{
kfree(s->private);
}
-static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
+static int
+sg_proc_seq_show_dev(struct seq_file *s, void *v)
{
struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
- Sg_device *sdp;
+ struct sg_device *sdp;
struct scsi_device *scsidp;
unsigned long iflags;
@@ -2513,10 +2554,11 @@ static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
return 0;
}
-static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
+static int
+sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
{
struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
- Sg_device *sdp;
+ struct sg_device *sdp;
struct scsi_device *scsidp;
unsigned long iflags;
@@ -2533,11 +2575,12 @@ static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
}
/* must be called while holding sg_index_lock */
-static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
+static void
+sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
{
int k, new_interface, blen, usg;
- Sg_request *srp;
- Sg_fd *fp;
+ struct sg_request *srp;
+ struct sg_fd *fp;
const sg_io_hdr_t *hp;
const char * cp;
unsigned int ms;
@@ -2596,10 +2639,11 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
}
}
-static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
+static int
+sg_proc_seq_show_debug(struct seq_file *s, void *v)
{
struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
- Sg_device *sdp;
+ struct sg_device *sdp;
unsigned long iflags;
if (it && (0 == it->index))
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 03/23] sg: sg_log and is_enabled
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 01/23] sg: move functions around Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 02/23] sg: remove typedefs, type+formatting cleanup Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 04/23] sg: rework sg_poll(), minor changes Douglas Gilbert
` (19 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare, Hannes Reinecke
Replace SCSI_LOG_TIMEOUT macros with SG_LOG macros across the driver.
The definition of SG_LOG calls SCSI_LOG_TIMEOUT if given and derived
pointers are non-zero, calls pr_info otherwise. SG_LOGS additionally
prints the sg device name and the thread id. The thread id is very
useful, even in single threaded invocations because the driver not
only uses the invocer's thread but also uses work queues and the
main callback (i.e. sg_rq_end_io()) may hit any thread. Some
interesting cases arise when the callback hits its invocer's
thread.
SG_LOGS takes 48 bytes on the stack to build this printf format
string: "sg%u: tid=%d" whose size is clearly bounded above by
the maximum size of those two integers.
Protecting against the 'current' pointer being zero is for safety
and the case where the boot device is SCSI and the sg driver is
built into the kernel. Also when debugging, getting a message
from a compromised kernel can be very useful in pinpointing the
location of the failure.
The simple fact that the SG_LOG macro is shorter than
SCSI_LOG_TIMEOUT macro allow more error message "payload" per line.
Also replace #if and #ifdef conditional compilations with
the IS_ENABLED macro.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 252 +++++++++++++++++++++++-----------------------
1 file changed, 125 insertions(+), 127 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 6615777931f7..d14ba4a5441c 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -57,6 +57,15 @@ static char *sg_version_date = "20190606";
#define SG_MAX_DEVS 32768
+/* Comment out the following line to compile out SCSI_LOGGING stuff */
+#define SG_DEBUG 1
+
+#if !IS_ENABLED(SG_DEBUG)
+#if IS_ENABLED(DEBUG) /* If SG_DEBUG not defined, check for DEBUG */
+#define SG_DEBUG DEBUG
+#endif
+#endif
+
/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
* of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
* than 16 bytes are "variable length" whose length is a multiple of 4
@@ -174,7 +183,7 @@ static ssize_t sg_new_write(struct sg_fd *sfp, struct file *file,
static int sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
u8 *cmnd, int timeout, int blocking);
static int sg_read_oxfer(struct sg_request *srp, char __user *outp,
- int num_read_xfer);
+ int num_xfer);
static void sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
static void sg_build_reserve(struct sg_fd *sfp, int req_size);
static void sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp,
@@ -187,14 +196,45 @@ static int sg_remove_request(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_device *sg_get_dev(int dev);
static void sg_device_destroy(struct kref *kref);
-#define SZ_SG_HEADER sizeof(struct sg_header)
-#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
-#define SZ_SG_IOVEC sizeof(sg_iovec_t)
-#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
+#define SZ_SG_HEADER ((int)sizeof(struct sg_header)) /* v1 and v2 header */
+#define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
+#define SZ_SG_REQ_INFO ((int)sizeof(struct sg_req_info))
+
+/*
+ * Kernel needs to be built with CONFIG_SCSI_LOGGING to see log messages.
+ * 'depth' is a number between 1 (most severe) and 7 (most noisy, most
+ * information). All messages are logged as informational (KERN_INFO). In
+ * the unexpected situation where sfp or sdp is NULL the macro reverts to
+ * a pr_info and ignores SCSI_LOG_TIMEOUT and always prints to the log.
+ * Example: this invocation: 'scsi_logging_level -s -T 3' will print
+ * depth (aka level) 1 and 2 SG_LOG() messages.
+ */
+
+#define SG_PROC_DEBUG_SZ 8192
+
+#if IS_ENABLED(CONFIG_SCSI_LOGGING) && IS_ENABLED(SG_DEBUG)
+#define SG_LOG_BUFF_SZ 48
+
+#define SG_LOG(depth, sfp, fmt, a...) \
+ do { \
+ char _b[SG_LOG_BUFF_SZ]; \
+ int _tid = (current ? current->pid : -1); \
+ struct sg_fd *_fp = sfp; \
+ struct sg_device *_sdp = _fp ? _fp->parentdp : NULL; \
+ \
+ if (likely(_sdp && _sdp->disk)) { \
+ snprintf(_b, sizeof(_b), "sg%u: tid=%d", \
+ _sdp->index, _tid); \
+ SCSI_LOG_TIMEOUT(depth, \
+ sdev_prefix_printk(KERN_INFO, \
+ _sdp->device, _b, fmt, ##a)); \
+ } else \
+ pr_info("sg: sdp or sfp NULL, " fmt, ##a); \
+ } while (0)
+#else
+#define SG_LOG(depth, sfp, fmt, a...)
+#endif /* end of CONFIG_SCSI_LOGGING && SG_DEBUG conditional */
-#define sg_printk(prefix, sdp, fmt, a...) \
- sdev_prefix_printk(prefix, (sdp)->device, \
- (sdp)->disk->disk_name, fmt, ##a)
/*
* The SCSI interfaces that use read() and write() as an asynchronous variant of
@@ -286,9 +326,6 @@ sg_open(struct inode *inode, struct file *filp)
if (IS_ERR(sdp))
return PTR_ERR(sdp);
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_open: flags=0x%x\n", op_flags));
-
/* This driver's module count bumped by fops_get in <linux/fs.h> */
/* Prevent the device driver from vanishing while we sleep */
retval = scsi_device_get(sdp->device);
@@ -346,6 +383,9 @@ sg_open(struct inode *inode, struct file *filp)
filp->private_data = sfp;
sdp->open_cnt++;
mutex_unlock(&sdp->open_rel_lock);
+ SG_LOG(3, sfp, "%s: minor=%d, op_flags=0x%x; %s count prior=%d%s\n",
+ __func__, min_dev, op_flags, "device open", sdp->open_cnt,
+ ((op_flags & O_NONBLOCK) ? " O_NONBLOCK" : ""));
retval = 0;
sg_put:
@@ -376,9 +416,10 @@ sg_release(struct inode *inode, struct file *filp)
sfp = filp->private_data;
sdp = sfp->parentdp;
+ SG_LOG(3, sfp, "%s: device open count prior=%d\n", __func__,
+ sdp->open_cnt);
if (!sdp)
return -ENXIO;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
mutex_lock(&sdp->open_rel_lock);
scsi_autopm_put_device(sdp->device);
@@ -423,10 +464,9 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
sfp = filp->private_data;
sdp = sfp->parentdp;
+ SG_LOG(3, sfp, "%s: write(3rd arg) count=%d\n", __func__, (int)count);
if (!sdp)
return -ENXIO;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_write: count=%d\n", (int) count));
if (atomic_read(&sdp->detaching))
return -ENODEV;
if (!((filp->f_flags & O_NONBLOCK) ||
@@ -447,8 +487,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
return -EIO; /* The minimum scsi command length is 6 bytes. */
if (!(srp = sg_add_request(sfp))) {
- SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
- "sg_write: queue full\n"));
+ SG_LOG(1, sfp, "%s: queue full\n", __func__);
return -EDOM;
}
buf += SZ_SG_HEADER;
@@ -463,9 +502,8 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
cmd_size = 12;
}
mutex_unlock(&sfp->f_mutex);
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
- "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
-/* Determine buffer size. */
+ SG_LOG(4, sfp, "%s: scsi opcode=0x%02x, cmd_size=%d\n", __func__,
+ (unsigned int)opcode, cmd_size);
input_size = count - cmd_size;
mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
mxsize -= SZ_SG_HEADER;
@@ -546,8 +584,7 @@ sg_new_write(struct sg_fd *sfp, struct file *file, const char __user *buf,
sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
if (!(srp = sg_add_request(sfp))) {
- SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_new_write: queue full\n"));
+ SG_LOG(1, sfp, "%s: queue full\n", __func__);
return -EDOM;
}
srp->sg_io_owned = sg_io_owned;
@@ -616,17 +653,15 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
hp->host_status = 0;
hp->driver_status = 0;
hp->resid = 0;
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
- (int) cmnd[0], (int) hp->cmd_len));
+ SG_LOG(4, sfp, "%s: opcode=0x%02x, cmd_sz=%d\n", __func__,
+ (int)cmnd[0], hp->cmd_len);
if (hp->dxfer_len >= SZ_256M)
return -EINVAL;
k = sg_start_req(srp, cmnd);
if (k) {
- SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_common_write: start_req err=%d\n", k));
+ SG_LOG(1, sfp, "%s: start_req err=%d\n", __func__, k);
sg_finish_rem_req(srp);
sg_remove_request(sfp, srp);
return k; /* probably out of space --> ENOMEM */
@@ -759,9 +794,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
sfp = filp->private_data;
sdp = sfp->parentdp;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "%s: count=%d\n", __func__,
- (int) count));
+ SG_LOG(3, sfp, "%s: read() count=%d\n", __func__, (int)count);
if (!sdp)
return -ENXIO;
@@ -956,10 +989,10 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
sfp = filp->private_data;
sdp = sfp->parentdp;
+ SG_LOG(6, sfp, "%s: cmd=0x%x, O_NONBLOCK=%d\n", __func__, cmd_in,
+ !!(filp->f_flags & O_NONBLOCK));
if (!sdp)
return -ENXIO;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
switch (cmd_in) {
@@ -1191,7 +1224,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
return scsi_ioctl(sdp->device, cmd_in, p);
}
-#ifdef CONFIG_COMPAT
+#if IS_ENABLED(CONFIG_COMPAT)
static long
sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
@@ -1250,24 +1283,16 @@ sg_poll(struct file *filp, poll_table * wait)
res |= EPOLLOUT | EPOLLWRNORM;
} else if (count < SG_MAX_QUEUE)
res |= EPOLLOUT | EPOLLWRNORM;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_poll: res=0x%x\n", (__force u32) res));
+ SG_LOG(3, sfp, "%s: res=0x%x\n", __func__, (__force u32)res);
return res;
}
static int
sg_fasync(int fd, struct file *filp, int mode)
{
- struct sg_device *sdp;
- struct sg_fd *sfp;
-
- sfp = filp->private_data;
- sdp = sfp->parentdp;
- if (!sdp)
- return -ENXIO;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_fasync: mode=%d\n", mode));
+ struct sg_fd *sfp = filp->private_data;
+ SG_LOG(3, sfp, "%s: mode(%s)\n", __func__, (mode ? "add" : "remove"));
return fasync_helper(fd, filp, mode, &sfp->async_qp);
}
@@ -1294,10 +1319,8 @@ sg_vma_fault(struct vm_fault *vmf)
offset = vmf->pgoff << PAGE_SHIFT;
if (offset >= rsv_schp->bufflen)
return VM_FAULT_SIGBUS;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_vma_fault: offset=%lu, scatg=%d\n",
- offset, rsv_schp->k_use_sg));
sa = vma->vm_start;
+ SG_LOG(3, sfp, "%s: vm_start=0x%lx, off=%lu\n", __func__, sa, offset);
length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
len = vma->vm_end - sa;
@@ -1337,9 +1360,8 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
return -ENXIO;
}
req_sz = vma->vm_end - vma->vm_start;
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_mmap starting, vm_start=%p, len=%d\n",
- (void *) vma->vm_start, (int) req_sz));
+ SG_LOG(3, sfp, "%s: vm_start=%p, len=%d\n", __func__,
+ (void *)vma->vm_start, (int)req_sz);
if (vma->vm_pgoff)
return -EINVAL; /* want no offset */
rsv_schp = &sfp->reserve;
@@ -1408,10 +1430,9 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
result = req->result;
resid = req->resid_len;
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
- "sg_cmd_done: pack_id=%d, res=0x%x\n",
- srp->header.pack_id, result));
srp->header.resid = resid;
+ SG_LOG(6, sfp, "%s: pack_id=%d, res=0x%x\n", __func__,
+ srp->header.pack_id, result);
ms = jiffies_to_msecs(jiffies);
srp->header.duration = (ms > srp->header.duration) ?
(ms - srp->header.duration) : 0;
@@ -1485,7 +1506,7 @@ static const struct file_operations sg_fops = {
.write = sg_write,
.poll = sg_poll,
.unlocked_ioctl = sg_ioctl,
-#ifdef CONFIG_COMPAT
+#if IS_ENABLED(CONFIG_COMPAT)
.compat_ioctl = sg_compat_ioctl,
#endif
.open = sg_open,
@@ -1532,7 +1553,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
k = error;
SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
- "sg_alloc: dev=%d \n", k));
+ "%s: dev=%d, sdp=0x%p ++\n", __func__, k, sdp));
sprintf(disk->disk_name, "sg%d", k);
disk->first_minor = k;
sdp->disk = disk;
@@ -1651,8 +1672,8 @@ sg_device_destroy(struct kref *kref)
idr_remove(&sg_index_idr, sdp->index);
write_unlock_irqrestore(&sg_index_lock, flags);
- SCSI_LOG_TIMEOUT(3,
- sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
+ sdev_printk(KERN_INFO, sdp->device, "[tid=%d] %s: sdp=0x%p --\n",
+ (current ? current->pid : -1), __func__, sdp);
put_disk(sdp->disk);
kfree(sdp);
@@ -1674,8 +1695,8 @@ sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
if (val > 1)
return; /* only want to do following once per device */
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "%s\n", __func__));
+ SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, sdp->device,
+ "%s: 0x%p\n", __func__, sdp));
read_lock_irqsave(&sdp->sfd_lock, iflags);
list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
@@ -1744,7 +1765,7 @@ init_sg(void)
return rc;
}
-#ifndef CONFIG_SCSI_PROC_FS
+#if !IS_ENABLED(CONFIG_SCSI_PROC_FS)
static int
sg_proc_init(void)
{
@@ -1755,9 +1776,8 @@ sg_proc_init(void)
static void __exit
exit_sg(void)
{
-#ifdef CONFIG_SCSI_PROC_FS
- remove_proc_subtree("scsi/sg", NULL);
-#endif /* CONFIG_SCSI_PROC_FS */
+ if (IS_ENABLED(CONFIG_SCSI_PROC_FS))
+ remove_proc_subtree("scsi/sg", NULL);
scsi_unregister_interface(&sg_interface);
class_destroy(sg_sysfs_class);
sg_sysfs_valid = 0;
@@ -1784,15 +1804,14 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
u8 *long_cmdp = NULL;
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_start_req: dxfer_len=%d\n",
- dxfer_len));
-
if (hp->cmd_len > BLK_MAX_CDB) {
long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
if (!long_cmdp)
return -ENOMEM;
+ SG_LOG(5, sfp, "%s: long_cmdp=0x%p ++\n", __func__, long_cmdp);
}
+ SG_LOG(4, sfp, "%s: dxfer_len=%d, data-%s\n", __func__, dxfer_len,
+ (rw ? "OUT" : "IN"));
/*
* NOTE
@@ -1904,9 +1923,8 @@ sg_finish_rem_req(struct sg_request *srp)
struct sg_fd *sfp = srp->parentfp;
struct sg_scatter_hold *req_schp = &srp->data;
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_finish_rem_req: res_used=%d\n",
- (int) srp->res_used));
+ SG_LOG(4, sfp, "%s: srp=0x%p%s\n", __func__, srp,
+ (srp->res_used) ? " rsv" : "");
if (srp->bio)
ret = blk_rq_unmap_user(srp->bio);
@@ -1953,9 +1971,8 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
++blk_size; /* don't know why */
/* round request up to next highest SG_SECTOR_SZ byte boundary */
blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_build_indirect: buff_size=%d, blk_size=%d\n",
- buff_size, blk_size));
+ SG_LOG(4, sfp, "%s: buff_size=%d, blk_size=%d\n", __func__, buff_size,
+ blk_size);
/* N.B. ret_sz carried into this block ... */
mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
@@ -1994,18 +2011,13 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
scatter_elem_sz_prev = ret_sz;
}
}
-
- SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
- k, num, ret_sz));
+ SG_LOG(5, sfp, "%s: k=%d, num=%d, ret_sz=%d\n", __func__, k,
+ num, ret_sz);
} /* end of for loop */
schp->page_order = order;
schp->k_use_sg = k;
- SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
- k, rem_sz));
-
+ SG_LOG(5, sfp, "%s: k_use_sg=%d, order=%d\n", __func__, k, order);
schp->bufflen = blk_size;
if (rem_sz > 0) /* must have failed */
return -ENOMEM;
@@ -2023,35 +2035,34 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
static void
sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
{
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
+ SG_LOG(4, sfp, "%s: num_sgat=%d\n", __func__, schp->k_use_sg);
if (schp->pages && schp->sglist_len > 0) {
if (!schp->dio_in_use) {
int k;
for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
- SCSI_LOG_TIMEOUT(5,
- sg_printk(KERN_INFO, sfp->parentdp,
- "sg_remove_scat: k=%d, pg=0x%p\n",
- k, schp->pages[k]));
+ SG_LOG(5, sfp, "%s: pg[%d]=0x%p --\n",
+ __func__, k, schp->pages[k]);
__free_pages(schp->pages[k], schp->page_order);
}
-
kfree(schp->pages);
}
}
memset(schp, 0, sizeof (*schp));
}
+/*
+ * For sg v1 and v2 interface: with a command yielding a data-in buffer, after
+ * it has arrived in kernel memory, this function copies it to the user space,
+ * appended to given struct sg_header object.
+ */
static int
sg_read_oxfer(struct sg_request *srp, char __user *outp, int num_read_xfer)
{
struct sg_scatter_hold *schp = &srp->data;
int k, num;
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
- "sg_read_oxfer: num_read_xfer=%d\n",
- num_read_xfer));
+ SG_LOG(4, srp->parentfp, "%s: num_xfer=%d\n", __func__, num_read_xfer);
if ((!outp) || (num_read_xfer <= 0))
return 0;
@@ -2081,8 +2092,7 @@ sg_build_reserve(struct sg_fd *sfp, int req_size)
{
struct sg_scatter_hold *schp = &sfp->reserve;
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_build_reserve: req_size=%d\n", req_size));
+ SG_LOG(3, sfp, "%s: buflen=%d\n", __func__, req_size);
do {
if (req_size < PAGE_SIZE)
req_size = PAGE_SIZE;
@@ -2102,8 +2112,7 @@ sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp, int size)
int k, num, rem;
srp->res_used = 1;
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_link_reserve: size=%d\n", size));
+ SG_LOG(4, sfp, "%s: size=%d\n", __func__, size);
rem = size;
num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
@@ -2121,8 +2130,7 @@ sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp, int size)
}
if (k >= rsv_schp->k_use_sg)
- SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
- "sg_link_reserve: BAD size\n"));
+ SG_LOG(1, sfp, "%s: BAD size\n", __func__);
}
static void
@@ -2130,9 +2138,8 @@ sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp)
{
struct sg_scatter_hold *req_schp = &srp->data;
- SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
- "sg_unlink_reserve: req->k_use_sg=%d\n",
- (int) req_schp->k_use_sg));
+ SG_LOG(4, srp->parentfp, "%s: req->k_use_sg=%d\n", __func__,
+ (int)req_schp->k_use_sg);
req_schp->k_use_sg = 0;
req_schp->bufflen = 0;
req_schp->pages = NULL;
@@ -2223,18 +2230,15 @@ sg_add_sfp(struct sg_device *sdp)
}
list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
write_unlock_irqrestore(&sdp->sfd_lock, iflags);
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_add_sfp: sfp=0x%p\n", sfp));
+ SG_LOG(3, sfp, "%s: sfp=0x%p\n", __func__, sfp);
if (unlikely(sg_big_buff != def_reserved_size))
sg_big_buff = def_reserved_size;
bufflen = min_t(int, sg_big_buff,
max_sectors_bytes(sdp->device->request_queue));
sg_build_reserve(sfp, bufflen);
- SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
- "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
- sfp->reserve.bufflen,
- sfp->reserve.k_use_sg));
+ SG_LOG(3, sfp, "%s: bufflen=%d, k_use_sg=%d\n", __func__,
+ sfp->reserve.bufflen, sfp->reserve.k_use_sg);
kref_get(&sdp->d_ref);
__module_get(THIS_MODULE);
@@ -2260,15 +2264,12 @@ sg_remove_sfp_usercontext(struct work_struct *work)
write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
if (sfp->reserve.bufflen > 0) {
- SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
- "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
- (int) sfp->reserve.bufflen,
- (int) sfp->reserve.k_use_sg));
+ SG_LOG(6, sfp, "%s: bufflen=%d, k_use_sg=%d\n", __func__,
+ (int)sfp->reserve.bufflen, (int)sfp->reserve.k_use_sg);
sg_remove_scat(sfp, &sfp->reserve);
}
- SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
- "sg_remove_sfp: sfp=0x%p\n", sfp));
+ SG_LOG(6, sfp, "%s: sfp=0x%p\n", __func__, sfp);
kfree(sfp);
scsi_device_put(sdp->device);
@@ -2291,7 +2292,6 @@ sg_remove_sfp(struct kref *kref)
schedule_work(&sfp->ew.work);
}
-#ifdef CONFIG_SCSI_PROC_FS
static int
sg_idr_max_id(int id, void *p, void *data)
{
@@ -2303,19 +2303,6 @@ sg_idr_max_id(int id, void *p, void *data)
return 0;
}
-static int
-sg_last_dev(void)
-{
- int k = -1;
- unsigned long iflags;
-
- read_lock_irqsave(&sg_index_lock, iflags);
- idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
- read_unlock_irqrestore(&sg_index_lock, iflags);
- return k + 1; /* origin 1 */
-}
-#endif
-
/* must be called with sg_index_lock held */
static struct sg_device *
sg_lookup_dev(int dev)
@@ -2345,7 +2332,7 @@ sg_get_dev(int dev)
return sdp;
}
-#ifdef CONFIG_SCSI_PROC_FS
+#if IS_ENABLED(CONFIG_SCSI_PROC_FS) /* long, almost to end of file */
static int sg_proc_seq_show_int(struct seq_file *s, void *v);
static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
@@ -2420,6 +2407,17 @@ sg_proc_init(void)
return 0;
}
+static int
+sg_last_dev(void)
+{
+ int k = -1;
+ unsigned long iflags;
+
+ read_lock_irqsave(&sg_index_lock, iflags);
+ idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
+ read_unlock_irqrestore(&sg_index_lock, iflags);
+ return k + 1; /* origin 1 */
+}
static int
sg_proc_seq_show_int(struct seq_file *s, void *v)
@@ -2678,7 +2676,7 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
return 0;
}
-#endif /* CONFIG_SCSI_PROC_FS */
+#endif /* CONFIG_SCSI_PROC_FS (~300 lines back) */
module_init(init_sg);
module_exit(exit_sg);
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 04/23] sg: rework sg_poll(), minor changes
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (2 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 03/23] sg: sg_log and is_enabled Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 05/23] sg: bitops in sg_device Douglas Gilbert
` (18 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare, Hannes Reinecke
Re-arrange code in sg_poll(). Rename sg_read_oxfer() to
sg_rd_append(). In sg_start_req() rename rw to r0w.
Plus associated changes demanded by checkpatch.pl
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 65 ++++++++++++++++++++++-------------------------
1 file changed, 30 insertions(+), 35 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index d14ba4a5441c..9aa1b1030033 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -177,13 +177,13 @@ static int sg_finish_rem_req(struct sg_request *srp);
static int sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
int buff_size);
static ssize_t sg_new_write(struct sg_fd *sfp, struct file *file,
- const char __user *buf, size_t count, int blocking,
- int read_only, int sg_io_owned,
- struct sg_request **o_srp);
+ const char __user *buf, size_t count, int blocking,
+ int read_only, int sg_io_owned,
+ struct sg_request **o_srp);
static int sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
u8 *cmnd, int timeout, int blocking);
-static int sg_read_oxfer(struct sg_request *srp, char __user *outp,
- int num_xfer);
+static int sg_rd_append(struct sg_request *srp, char __user *outp,
+ int num_xfer);
static void sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
static void sg_build_reserve(struct sg_fd *sfp, int req_size);
static void sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp,
@@ -918,7 +918,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
if (count > old_hdr->reply_len)
count = old_hdr->reply_len;
if (count > SZ_SG_HEADER) {
- if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
+ if (sg_rd_append(srp, buf, count - SZ_SG_HEADER)) {
retval = -EFAULT;
goto free_old_hdr;
}
@@ -1253,38 +1253,34 @@ sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
static __poll_t
sg_poll(struct file *filp, poll_table * wait)
{
- __poll_t res = 0;
- struct sg_device *sdp;
- struct sg_fd *sfp;
+ __poll_t p_res = 0;
+ struct sg_fd *sfp = filp->private_data;
struct sg_request *srp;
int count = 0;
unsigned long iflags;
- sfp = filp->private_data;
if (!sfp)
return EPOLLERR;
- sdp = sfp->parentdp;
- if (!sdp)
- return EPOLLERR;
poll_wait(filp, &sfp->read_wait, wait);
read_lock_irqsave(&sfp->rq_list_lock, iflags);
list_for_each_entry(srp, &sfp->rq_list, entry) {
/* if any read waiting, flag it */
- if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
- res = EPOLLIN | EPOLLRDNORM;
+ if (p_res == 0 && srp->done == 1 && !srp->sg_io_owned)
+ p_res = EPOLLIN | EPOLLRDNORM;
++count;
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- if (atomic_read(&sdp->detaching))
- res |= EPOLLHUP;
- else if (!sfp->cmd_q) {
- if (0 == count)
- res |= EPOLLOUT | EPOLLWRNORM;
- } else if (count < SG_MAX_QUEUE)
- res |= EPOLLOUT | EPOLLWRNORM;
- SG_LOG(3, sfp, "%s: res=0x%x\n", __func__, (__force u32)res);
- return res;
+ if (sfp->parentdp && atomic_read(&sfp->parentdp->detaching)) {
+ p_res |= EPOLLHUP;
+ } else if (!sfp->cmd_q) {
+ if (count == 0)
+ p_res |= EPOLLOUT | EPOLLWRNORM;
+ } else if (count < SG_MAX_QUEUE) {
+ p_res |= EPOLLOUT | EPOLLWRNORM;
+ }
+ SG_LOG(3, sfp, "%s: p_res=0x%x\n", __func__, (__force u32)p_res);
+ return p_res;
}
static int
@@ -1801,7 +1797,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
struct sg_scatter_hold *rsv_schp = &sfp->reserve;
struct request_queue *q = sfp->parentdp->device->request_queue;
struct rq_map_data *md, map_data;
- int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
+ int r0w = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
u8 *long_cmdp = NULL;
if (hp->cmd_len > BLK_MAX_CDB) {
@@ -1811,7 +1807,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
SG_LOG(5, sfp, "%s: long_cmdp=0x%p ++\n", __func__, long_cmdp);
}
SG_LOG(4, sfp, "%s: dxfer_len=%d, data-%s\n", __func__, dxfer_len,
- (rw ? "OUT" : "IN"));
+ (r0w ? "OUT" : "IN"));
/*
* NOTE
@@ -1888,7 +1884,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
struct iovec *iov = NULL;
struct iov_iter i;
- res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
+ res = import_iovec(r0w, hp->dxferp, iov_count, 0, &iov, &i);
if (res < 0)
return res;
@@ -2057,33 +2053,32 @@ sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
* appended to given struct sg_header object.
*/
static int
-sg_read_oxfer(struct sg_request *srp, char __user *outp, int num_read_xfer)
+sg_rd_append(struct sg_request *srp, char __user *outp, int num_xfer)
{
struct sg_scatter_hold *schp = &srp->data;
int k, num;
- SG_LOG(4, srp->parentfp, "%s: num_xfer=%d\n", __func__, num_read_xfer);
- if ((!outp) || (num_read_xfer <= 0))
+ SG_LOG(4, srp->parentfp, "%s: num_xfer=%d\n", __func__, num_xfer);
+ if (!outp || num_xfer <= 0)
return 0;
num = 1 << (PAGE_SHIFT + schp->page_order);
for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
- if (num > num_read_xfer) {
+ if (num > num_xfer) {
if (__copy_to_user(outp, page_address(schp->pages[k]),
- num_read_xfer))
+ num_xfer))
return -EFAULT;
break;
} else {
if (__copy_to_user(outp, page_address(schp->pages[k]),
num))
return -EFAULT;
- num_read_xfer -= num;
- if (num_read_xfer <= 0)
+ num_xfer -= num;
+ if (num_xfer <= 0)
break;
outp += num;
}
}
-
return 0;
}
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 05/23] sg: bitops in sg_device
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (3 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 04/23] sg: rework sg_poll(), minor changes Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:05 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 06/23] sg: make open count an atomic Douglas Gilbert
` (17 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Introduce bitops in sg_device to replace an atomic, a bool and a
char. That char (sgdebug) had been reduced to only two states.
Add some associated macros to make the code a little clearer.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 104 +++++++++++++++++++++++-----------------------
1 file changed, 53 insertions(+), 51 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 9aa1b1030033..97ce84f0c51b 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -74,6 +74,11 @@ static char *sg_version_date = "20190606";
#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
+/* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
+#define SG_FDEV_EXCLUDE 0 /* have fd open with O_EXCL */
+#define SG_FDEV_DETACHING 1 /* may be unexpected device removal */
+#define SG_FDEV_LOG_SENSE 2 /* set by ioctl(SG_SET_DEBUG) */
+
int sg_big_buff = SG_DEF_RESERVED_SIZE;
/* N.B. This variable is readable and writeable via
/proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
@@ -155,14 +160,12 @@ struct sg_device { /* holds the state of each scsi generic device */
struct scsi_device *device;
wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
struct mutex open_rel_lock; /* held when in open() or release() */
- int sg_tablesize; /* adapter's max scatter-gather table size */
- u32 index; /* device index number */
struct list_head sfds;
rwlock_t sfd_lock; /* protect access to sfd list */
- atomic_t detaching; /* 0->device usable, 1->device detaching */
- bool exclude; /* 1->open(O_EXCL) succeeded and is active */
+ int sg_tablesize; /* adapter's max scatter-gather table size */
+ u32 index; /* device index number */
int open_cnt; /* count of opens (perhaps < num(sfds) ) */
- char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
+ unsigned long fdev_bm[1]; /* see SG_FDEV_* defines above */
struct gendisk *disk;
struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
struct kref d_ref;
@@ -200,6 +203,9 @@ static void sg_device_destroy(struct kref *kref);
#define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
#define SZ_SG_REQ_INFO ((int)sizeof(struct sg_req_info))
+#define SG_IS_DETACHING(sdp) test_bit(SG_FDEV_DETACHING, (sdp)->fdev_bm)
+#define SG_HAVE_EXCLUDE(sdp) test_bit(SG_FDEV_EXCLUDE, (sdp)->fdev_bm)
+
/*
* Kernel needs to be built with CONFIG_SCSI_LOGGING to see log messages.
* 'depth' is a number between 1 (most severe) and 7 (most noisy, most
@@ -273,26 +279,26 @@ sg_wait_open_event(struct sg_device *sdp, bool o_excl)
while (sdp->open_cnt > 0) {
mutex_unlock(&sdp->open_rel_lock);
retval = wait_event_interruptible(sdp->open_wait,
- (atomic_read(&sdp->detaching) ||
+ (SG_IS_DETACHING(sdp) ||
!sdp->open_cnt));
mutex_lock(&sdp->open_rel_lock);
if (retval) /* -ERESTARTSYS */
return retval;
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
}
} else {
- while (sdp->exclude) {
+ while (SG_HAVE_EXCLUDE(sdp)) {
mutex_unlock(&sdp->open_rel_lock);
retval = wait_event_interruptible(sdp->open_wait,
- (atomic_read(&sdp->detaching) ||
- !sdp->exclude));
+ (SG_IS_DETACHING(sdp) ||
+ !SG_HAVE_EXCLUDE(sdp)));
mutex_lock(&sdp->open_rel_lock);
if (retval) /* -ERESTARTSYS */
return retval;
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
}
}
@@ -354,7 +360,7 @@ sg_open(struct inode *inode, struct file *filp)
goto error_mutex_locked;
}
} else {
- if (sdp->exclude) {
+ if (SG_HAVE_EXCLUDE(sdp)) {
retval = -EBUSY;
goto error_mutex_locked;
}
@@ -367,10 +373,10 @@ sg_open(struct inode *inode, struct file *filp)
/* N.B. at this point we are holding the open_rel_lock */
if (o_excl)
- sdp->exclude = true;
+ set_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm);
if (sdp->open_cnt < 1) { /* no existing opens */
- sdp->sgdebug = 0;
+ clear_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm);
q = sdp->device->request_queue;
sdp->sg_tablesize = queue_max_segments(q);
}
@@ -393,8 +399,8 @@ sg_open(struct inode *inode, struct file *filp)
return retval;
out_undo:
- if (o_excl) {
- sdp->exclude = false; /* undo if error */
+ if (o_excl) { /* undo if error */
+ clear_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm);
wake_up_interruptible(&sdp->open_wait);
}
error_mutex_locked:
@@ -428,12 +434,10 @@ sg_release(struct inode *inode, struct file *filp)
/* possibly many open()s waiting on exlude clearing, start many;
* only open(O_EXCL)s wait on 0==open_cnt so only start one */
- if (sdp->exclude) {
- sdp->exclude = false;
+ if (test_and_clear_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm))
wake_up_interruptible_all(&sdp->open_wait);
- } else if (0 == sdp->open_cnt) {
+ else if (sdp->open_cnt == 0)
wake_up_interruptible(&sdp->open_wait);
- }
mutex_unlock(&sdp->open_rel_lock);
return 0;
}
@@ -467,7 +471,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
SG_LOG(3, sfp, "%s: write(3rd arg) count=%d\n", __func__, (int)count);
if (!sdp)
return -ENXIO;
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
if (!((filp->f_flags & O_NONBLOCK) ||
scsi_block_when_processing_errors(sdp->device)))
@@ -666,7 +670,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
sg_remove_request(sfp, srp);
return k; /* probably out of space --> ENOMEM */
}
- if (atomic_read(&sdp->detaching)) {
+ if (SG_IS_DETACHING(sdp)) {
if (srp->bio) {
scsi_req_free_cmd(scsi_req(srp->rq));
blk_put_request(srp->rq);
@@ -831,7 +835,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
}
srp = sg_get_rq_mark(sfp, req_pack_id);
if (!srp) { /* now wait on packet to arrive */
- if (atomic_read(&sdp->detaching)) {
+ if (SG_IS_DETACHING(sdp)) {
retval = -ENODEV;
goto free_old_hdr;
}
@@ -840,9 +844,9 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
goto free_old_hdr;
}
retval = wait_event_interruptible(sfp->read_wait,
- (atomic_read(&sdp->detaching) ||
+ (SG_IS_DETACHING(sdp) ||
(srp = sg_get_rq_mark(sfp, req_pack_id))));
- if (atomic_read(&sdp->detaching)) {
+ if (SG_IS_DETACHING(sdp)) {
retval = -ENODEV;
goto free_old_hdr;
}
@@ -997,7 +1001,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
switch (cmd_in) {
case SG_IO:
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
if (!scsi_block_when_processing_errors(sdp->device))
return -ENXIO;
@@ -1008,8 +1012,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
if (result < 0)
return result;
result = wait_event_interruptible(sfp->read_wait,
- (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
- if (atomic_read(&sdp->detaching))
+ (srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
write_lock_irq(&sfp->rq_list_lock);
if (srp->done) {
@@ -1052,7 +1056,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
else {
sg_scsi_id_t __user *sg_idp = p;
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
__put_user((int) sdp->device->host->host_no,
&sg_idp->host_no);
@@ -1176,18 +1180,18 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
return result;
}
case SG_EMULATED_HOST:
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
return put_user(sdp->device->host->hostt->emulated, ip);
case SCSI_IOCTL_SEND_COMMAND:
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
case SG_SET_DEBUG:
result = get_user(val, ip);
if (result)
return result;
- sdp->sgdebug = (char) val;
+ assign_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm, val);
return 0;
case BLKSECTGET:
return put_user(max_sectors_bytes(sdp->device->request_queue),
@@ -1208,7 +1212,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
case SCSI_IOCTL_PROBE_HOST:
case SG_GET_TRANSFORM:
case SG_SCSI_RESET:
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
return -ENODEV;
break;
default:
@@ -1271,7 +1275,7 @@ sg_poll(struct file *filp, poll_table * wait)
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- if (sfp->parentdp && atomic_read(&sfp->parentdp->detaching)) {
+ if (sfp->parentdp && SG_IS_DETACHING(sfp->parentdp)) {
p_res |= EPOLLHUP;
} else if (!sfp->cmd_q) {
if (count == 0)
@@ -1419,7 +1423,7 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
return;
sdp = sfp->parentdp;
- if (unlikely(atomic_read(&sdp->detaching)))
+ if (unlikely(SG_IS_DETACHING(sdp)))
pr_info("%s: device detaching\n", __func__);
sense = req->sense;
@@ -1440,9 +1444,9 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
srp->header.msg_status = msg_byte(result);
srp->header.host_status = host_byte(result);
srp->header.driver_status = driver_byte(result);
- if ((sdp->sgdebug > 0) &&
- ((CHECK_CONDITION == srp->header.masked_status) ||
- (COMMAND_TERMINATED == srp->header.masked_status)))
+ if (test_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm) &&
+ (srp->header.masked_status == CHECK_CONDITION ||
+ srp->header.masked_status == COMMAND_TERMINATED))
__scsi_print_sense(sdp->device, __func__, sense,
SCSI_SENSE_BUFFERSIZE);
@@ -1557,7 +1561,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
mutex_init(&sdp->open_rel_lock);
INIT_LIST_HEAD(&sdp->sfds);
init_waitqueue_head(&sdp->open_wait);
- atomic_set(&sdp->detaching, 0);
+ clear_bit(SG_FDEV_DETACHING, sdp->fdev_bm);
rwlock_init(&sdp->sfd_lock);
sdp->sg_tablesize = queue_max_segments(q);
sdp->index = k;
@@ -1682,13 +1686,11 @@ sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
struct sg_device *sdp = dev_get_drvdata(cl_dev);
unsigned long iflags;
struct sg_fd *sfp;
- int val;
if (!sdp)
return;
- /* want sdp->detaching non-zero as soon as possible */
- val = atomic_inc_return(&sdp->detaching);
- if (val > 1)
+ /* set this flag as soon as possible as it could be a surprise */
+ if (test_and_set_bit(SG_FDEV_DETACHING, sdp->fdev_bm))
return; /* only want to do following once per device */
SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, sdp->device,
@@ -2218,7 +2220,7 @@ sg_add_sfp(struct sg_device *sdp)
sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
sfp->parentdp = sdp;
write_lock_irqsave(&sdp->sfd_lock, iflags);
- if (atomic_read(&sdp->detaching)) {
+ if (SG_IS_DETACHING(sdp)) {
write_unlock_irqrestore(&sdp->sfd_lock, iflags);
kfree(sfp);
return ERR_PTR(-ENODEV);
@@ -2315,8 +2317,8 @@ sg_get_dev(int dev)
sdp = sg_lookup_dev(dev);
if (!sdp)
sdp = ERR_PTR(-ENXIO);
- else if (atomic_read(&sdp->detaching)) {
- /* If sdp->detaching, then the refcount may already be 0, in
+ else if (SG_IS_DETACHING(sdp)) {
+ /* If detaching, then the refcount may already be 0, in
* which case it would be a bug to do kref_get().
*/
sdp = ERR_PTR(-ENODEV);
@@ -2530,8 +2532,7 @@ sg_proc_seq_show_dev(struct seq_file *s, void *v)
read_lock_irqsave(&sg_index_lock, iflags);
sdp = it ? sg_lookup_dev(it->index) : NULL;
- if ((NULL == sdp) || (NULL == sdp->device) ||
- (atomic_read(&sdp->detaching)))
+ if (!sdp || !sdp->device || SG_IS_DETACHING(sdp))
seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
else {
scsidp = sdp->device;
@@ -2558,7 +2559,7 @@ sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
read_lock_irqsave(&sg_index_lock, iflags);
sdp = it ? sg_lookup_dev(it->index) : NULL;
scsidp = sdp ? sdp->device : NULL;
- if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
+ if (sdp && scsidp && !SG_IS_DETACHING(sdp))
seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
scsidp->vendor, scsidp->model, scsidp->rev);
else
@@ -2650,7 +2651,7 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
read_lock(&sdp->sfd_lock);
if (!list_empty(&sdp->sfds)) {
seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
- if (atomic_read(&sdp->detaching))
+ if (SG_IS_DETACHING(sdp))
seq_puts(s, "detaching pending close ");
else if (sdp->device) {
struct scsi_device *scsidp = sdp->device;
@@ -2662,7 +2663,8 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
scsidp->host->hostt->emulated);
}
seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
- sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
+ sdp->sg_tablesize, SG_HAVE_EXCLUDE(sdp),
+ sdp->open_cnt);
sg_proc_debug_helper(s, sdp);
}
read_unlock(&sdp->sfd_lock);
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 05/23] sg: bitops in sg_device
2019-10-08 7:50 ` [PATCH v5 05/23] sg: bitops in sg_device Douglas Gilbert
@ 2019-10-18 10:05 ` Hannes Reinecke
2019-10-21 13:22 ` Douglas Gilbert
0 siblings, 1 reply; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:05 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Introduce bitops in sg_device to replace an atomic, a bool and a
> char. That char (sgdebug) had been reduced to only two states.
> Add some associated macros to make the code a little clearer.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 104 +++++++++++++++++++++++-----------------------
> 1 file changed, 53 insertions(+), 51 deletions(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 9aa1b1030033..97ce84f0c51b 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -74,6 +74,11 @@ static char *sg_version_date = "20190606";
>
> #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
>
> +/* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
> +#define SG_FDEV_EXCLUDE 0 /* have fd open with O_EXCL */
> +#define SG_FDEV_DETACHING 1 /* may be unexpected device removal */
> +#define SG_FDEV_LOG_SENSE 2 /* set by ioctl(SG_SET_DEBUG) */
> +
> int sg_big_buff = SG_DEF_RESERVED_SIZE;
> /* N.B. This variable is readable and writeable via
> /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
> @@ -155,14 +160,12 @@ struct sg_device { /* holds the state of each scsi generic device */
> struct scsi_device *device;
> wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
> struct mutex open_rel_lock; /* held when in open() or release() */
> - int sg_tablesize; /* adapter's max scatter-gather table size */
> - u32 index; /* device index number */
> struct list_head sfds;
> rwlock_t sfd_lock; /* protect access to sfd list */
> - atomic_t detaching; /* 0->device usable, 1->device detaching */
> - bool exclude; /* 1->open(O_EXCL) succeeded and is active */
> + int sg_tablesize; /* adapter's max scatter-gather table size */
> + u32 index; /* device index number */
> int open_cnt; /* count of opens (perhaps < num(sfds) ) */
> - char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
> + unsigned long fdev_bm[1]; /* see SG_FDEV_* defines above */
> struct gendisk *disk;
> struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
> struct kref d_ref;
> @@ -200,6 +203,9 @@ static void sg_device_destroy(struct kref *kref);
> #define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
> #define SZ_SG_REQ_INFO ((int)sizeof(struct sg_req_info))
>
> +#define SG_IS_DETACHING(sdp) test_bit(SG_FDEV_DETACHING, (sdp)->fdev_bm)
> +#define SG_HAVE_EXCLUDE(sdp) test_bit(SG_FDEV_EXCLUDE, (sdp)->fdev_bm)
> +
> /*
> * Kernel needs to be built with CONFIG_SCSI_LOGGING to see log messages.
> * 'depth' is a number between 1 (most severe) and 7 (most noisy, most
> @@ -273,26 +279,26 @@ sg_wait_open_event(struct sg_device *sdp, bool o_excl)
> while (sdp->open_cnt > 0) {
> mutex_unlock(&sdp->open_rel_lock);
> retval = wait_event_interruptible(sdp->open_wait,
> - (atomic_read(&sdp->detaching) ||
> + (SG_IS_DETACHING(sdp) ||
> !sdp->open_cnt));
> mutex_lock(&sdp->open_rel_lock);
>
> if (retval) /* -ERESTARTSYS */
> return retval;
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> }
> } else {
> - while (sdp->exclude) {
> + while (SG_HAVE_EXCLUDE(sdp)) {
> mutex_unlock(&sdp->open_rel_lock);
> retval = wait_event_interruptible(sdp->open_wait,
> - (atomic_read(&sdp->detaching) ||
> - !sdp->exclude));
> + (SG_IS_DETACHING(sdp) ||
> + !SG_HAVE_EXCLUDE(sdp)));
> mutex_lock(&sdp->open_rel_lock);
>
> if (retval) /* -ERESTARTSYS */
> return retval;
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> }
> }
> @@ -354,7 +360,7 @@ sg_open(struct inode *inode, struct file *filp)
> goto error_mutex_locked;
> }
> } else {
> - if (sdp->exclude) {
> + if (SG_HAVE_EXCLUDE(sdp)) {
> retval = -EBUSY;
> goto error_mutex_locked;
> }
> @@ -367,10 +373,10 @@ sg_open(struct inode *inode, struct file *filp)
>
> /* N.B. at this point we are holding the open_rel_lock */
> if (o_excl)
> - sdp->exclude = true;
> + set_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm);
>
> if (sdp->open_cnt < 1) { /* no existing opens */
> - sdp->sgdebug = 0;
> + clear_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm);
> q = sdp->device->request_queue;
> sdp->sg_tablesize = queue_max_segments(q);
> }
> @@ -393,8 +399,8 @@ sg_open(struct inode *inode, struct file *filp)
> return retval;
>
> out_undo:
> - if (o_excl) {
> - sdp->exclude = false; /* undo if error */
> + if (o_excl) { /* undo if error */
> + clear_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm);
> wake_up_interruptible(&sdp->open_wait);
> }
> error_mutex_locked:
> @@ -428,12 +434,10 @@ sg_release(struct inode *inode, struct file *filp)
>
> /* possibly many open()s waiting on exlude clearing, start many;
> * only open(O_EXCL)s wait on 0==open_cnt so only start one */
> - if (sdp->exclude) {
> - sdp->exclude = false;
> + if (test_and_clear_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm))
> wake_up_interruptible_all(&sdp->open_wait);
> - } else if (0 == sdp->open_cnt) {
> + else if (sdp->open_cnt == 0)
> wake_up_interruptible(&sdp->open_wait);
> - }
> mutex_unlock(&sdp->open_rel_lock);
> return 0;
> }
> @@ -467,7 +471,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
> SG_LOG(3, sfp, "%s: write(3rd arg) count=%d\n", __func__, (int)count);
> if (!sdp)
> return -ENXIO;
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> if (!((filp->f_flags & O_NONBLOCK) ||
> scsi_block_when_processing_errors(sdp->device)))
> @@ -666,7 +670,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
> sg_remove_request(sfp, srp);
> return k; /* probably out of space --> ENOMEM */
> }
> - if (atomic_read(&sdp->detaching)) {
> + if (SG_IS_DETACHING(sdp)) {
> if (srp->bio) {
> scsi_req_free_cmd(scsi_req(srp->rq));
> blk_put_request(srp->rq);
> @@ -831,7 +835,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
> }
> srp = sg_get_rq_mark(sfp, req_pack_id);
> if (!srp) { /* now wait on packet to arrive */
> - if (atomic_read(&sdp->detaching)) {
> + if (SG_IS_DETACHING(sdp)) {
> retval = -ENODEV;
> goto free_old_hdr;
> }
> @@ -840,9 +844,9 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
> goto free_old_hdr;
> }
> retval = wait_event_interruptible(sfp->read_wait,
> - (atomic_read(&sdp->detaching) ||
> + (SG_IS_DETACHING(sdp) ||
> (srp = sg_get_rq_mark(sfp, req_pack_id))));
> - if (atomic_read(&sdp->detaching)) {
> + if (SG_IS_DETACHING(sdp)) {
> retval = -ENODEV;
> goto free_old_hdr;
> }
> @@ -997,7 +1001,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
>
> switch (cmd_in) {
> case SG_IO:
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> if (!scsi_block_when_processing_errors(sdp->device))
> return -ENXIO;
> @@ -1008,8 +1012,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
> if (result < 0)
> return result;
> result = wait_event_interruptible(sfp->read_wait,
> - (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
> - if (atomic_read(&sdp->detaching))
> + (srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> write_lock_irq(&sfp->rq_list_lock);
> if (srp->done) {
> @@ -1052,7 +1056,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
> else {
> sg_scsi_id_t __user *sg_idp = p;
>
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> __put_user((int) sdp->device->host->host_no,
> &sg_idp->host_no);
> @@ -1176,18 +1180,18 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
> return result;
> }
> case SG_EMULATED_HOST:
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> return put_user(sdp->device->host->hostt->emulated, ip);
> case SCSI_IOCTL_SEND_COMMAND:
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
> case SG_SET_DEBUG:
> result = get_user(val, ip);
> if (result)
> return result;
> - sdp->sgdebug = (char) val;
> + assign_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm, val);
> return 0;
> case BLKSECTGET:
> return put_user(max_sectors_bytes(sdp->device->request_queue),
> @@ -1208,7 +1212,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
> case SCSI_IOCTL_PROBE_HOST:
> case SG_GET_TRANSFORM:
> case SG_SCSI_RESET:
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> return -ENODEV;
> break;
> default:
> @@ -1271,7 +1275,7 @@ sg_poll(struct file *filp, poll_table * wait)
> }
> read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
>
> - if (sfp->parentdp && atomic_read(&sfp->parentdp->detaching)) {
> + if (sfp->parentdp && SG_IS_DETACHING(sfp->parentdp)) {
> p_res |= EPOLLHUP;
> } else if (!sfp->cmd_q) {
> if (count == 0)
> @@ -1419,7 +1423,7 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
> return;
>
> sdp = sfp->parentdp;
> - if (unlikely(atomic_read(&sdp->detaching)))
> + if (unlikely(SG_IS_DETACHING(sdp)))
> pr_info("%s: device detaching\n", __func__);
>
> sense = req->sense;
> @@ -1440,9 +1444,9 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
> srp->header.msg_status = msg_byte(result);
> srp->header.host_status = host_byte(result);
> srp->header.driver_status = driver_byte(result);
> - if ((sdp->sgdebug > 0) &&
> - ((CHECK_CONDITION == srp->header.masked_status) ||
> - (COMMAND_TERMINATED == srp->header.masked_status)))
> + if (test_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm) &&
> + (srp->header.masked_status == CHECK_CONDITION ||
> + srp->header.masked_status == COMMAND_TERMINATED))
> __scsi_print_sense(sdp->device, __func__, sense,
> SCSI_SENSE_BUFFERSIZE);
>
> @@ -1557,7 +1561,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
> mutex_init(&sdp->open_rel_lock);
> INIT_LIST_HEAD(&sdp->sfds);
> init_waitqueue_head(&sdp->open_wait);
> - atomic_set(&sdp->detaching, 0);
> + clear_bit(SG_FDEV_DETACHING, sdp->fdev_bm);
> rwlock_init(&sdp->sfd_lock);
> sdp->sg_tablesize = queue_max_segments(q);
> sdp->index = k;
> @@ -1682,13 +1686,11 @@ sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
> struct sg_device *sdp = dev_get_drvdata(cl_dev);
> unsigned long iflags;
> struct sg_fd *sfp;
> - int val;
>
> if (!sdp)
> return;
> - /* want sdp->detaching non-zero as soon as possible */
> - val = atomic_inc_return(&sdp->detaching);
> - if (val > 1)
> + /* set this flag as soon as possible as it could be a surprise */
> + if (test_and_set_bit(SG_FDEV_DETACHING, sdp->fdev_bm))
> return; /* only want to do following once per device */
>
> SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, sdp->device,
> @@ -2218,7 +2220,7 @@ sg_add_sfp(struct sg_device *sdp)
> sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
> sfp->parentdp = sdp;
> write_lock_irqsave(&sdp->sfd_lock, iflags);
> - if (atomic_read(&sdp->detaching)) {
> + if (SG_IS_DETACHING(sdp)) {
> write_unlock_irqrestore(&sdp->sfd_lock, iflags);
> kfree(sfp);
> return ERR_PTR(-ENODEV);
> @@ -2315,8 +2317,8 @@ sg_get_dev(int dev)
> sdp = sg_lookup_dev(dev);
> if (!sdp)
> sdp = ERR_PTR(-ENXIO);
> - else if (atomic_read(&sdp->detaching)) {
> - /* If sdp->detaching, then the refcount may already be 0, in
> + else if (SG_IS_DETACHING(sdp)) {
> + /* If detaching, then the refcount may already be 0, in
> * which case it would be a bug to do kref_get().
> */
> sdp = ERR_PTR(-ENODEV);
> @@ -2530,8 +2532,7 @@ sg_proc_seq_show_dev(struct seq_file *s, void *v)
>
> read_lock_irqsave(&sg_index_lock, iflags);
> sdp = it ? sg_lookup_dev(it->index) : NULL;
> - if ((NULL == sdp) || (NULL == sdp->device) ||
> - (atomic_read(&sdp->detaching)))
> + if (!sdp || !sdp->device || SG_IS_DETACHING(sdp))
> seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
> else {
> scsidp = sdp->device;
> @@ -2558,7 +2559,7 @@ sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
> read_lock_irqsave(&sg_index_lock, iflags);
> sdp = it ? sg_lookup_dev(it->index) : NULL;
> scsidp = sdp ? sdp->device : NULL;
> - if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
> + if (sdp && scsidp && !SG_IS_DETACHING(sdp))
> seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
> scsidp->vendor, scsidp->model, scsidp->rev);
> else
> @@ -2650,7 +2651,7 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
> read_lock(&sdp->sfd_lock);
> if (!list_empty(&sdp->sfds)) {
> seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
> - if (atomic_read(&sdp->detaching))
> + if (SG_IS_DETACHING(sdp))
> seq_puts(s, "detaching pending close ");
> else if (sdp->device) {
> struct scsi_device *scsidp = sdp->device;
> @@ -2662,7 +2663,8 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
> scsidp->host->hostt->emulated);
> }
> seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
> - sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
> + sdp->sg_tablesize, SG_HAVE_EXCLUDE(sdp),
> + sdp->open_cnt);
> sg_proc_debug_helper(s, sdp);
> }
> read_unlock(&sdp->sfd_lock);
>
One thing to keep in mind here is that 'set_bit()' is not atomic; it
needs to be followed by a memory barrier or being replaced by
test_and_set_bit() if possible.
Please audit the code if that poses a problem.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread* Re: [PATCH v5 05/23] sg: bitops in sg_device
2019-10-18 10:05 ` Hannes Reinecke
@ 2019-10-21 13:22 ` Douglas Gilbert
2019-10-21 13:38 ` Hannes Reinecke
0 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-21 13:22 UTC (permalink / raw)
To: Hannes Reinecke, linux-scsi; +Cc: martin.petersen, jejb
On 2019-10-18 6:05 a.m., Hannes Reinecke wrote:
> On 10/8/19 9:50 AM, Douglas Gilbert wrote:
>> Introduce bitops in sg_device to replace an atomic, a bool and a
>> char. That char (sgdebug) had been reduced to only two states.
>> Add some associated macros to make the code a little clearer.
>>
>> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
>> ---
>> drivers/scsi/sg.c | 104 +++++++++++++++++++++++-----------------------
>> 1 file changed, 53 insertions(+), 51 deletions(-)
>>
>> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
>> index 9aa1b1030033..97ce84f0c51b 100644
>> --- a/drivers/scsi/sg.c
>> +++ b/drivers/scsi/sg.c
>> @@ -74,6 +74,11 @@ static char *sg_version_date = "20190606";
>>
>> #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
>>
>> +/* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
>> +#define SG_FDEV_EXCLUDE 0 /* have fd open with O_EXCL */
>> +#define SG_FDEV_DETACHING 1 /* may be unexpected device removal */
>> +#define SG_FDEV_LOG_SENSE 2 /* set by ioctl(SG_SET_DEBUG) */
>> +
>> int sg_big_buff = SG_DEF_RESERVED_SIZE;
>> /* N.B. This variable is readable and writeable via
>> /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
>> @@ -155,14 +160,12 @@ struct sg_device { /* holds the state of each scsi generic device */
>> struct scsi_device *device;
>> wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
>> struct mutex open_rel_lock; /* held when in open() or release() */
>> - int sg_tablesize; /* adapter's max scatter-gather table size */
>> - u32 index; /* device index number */
>> struct list_head sfds;
>> rwlock_t sfd_lock; /* protect access to sfd list */
>> - atomic_t detaching; /* 0->device usable, 1->device detaching */
>> - bool exclude; /* 1->open(O_EXCL) succeeded and is active */
>> + int sg_tablesize; /* adapter's max scatter-gather table size */
>> + u32 index; /* device index number */
>> int open_cnt; /* count of opens (perhaps < num(sfds) ) */
>> - char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
>> + unsigned long fdev_bm[1]; /* see SG_FDEV_* defines above */
>> struct gendisk *disk;
>> struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
>> struct kref d_ref;
>> @@ -200,6 +203,9 @@ static void sg_device_destroy(struct kref *kref);
>> #define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
>> #define SZ_SG_REQ_INFO ((int)sizeof(struct sg_req_info))
>>
>> +#define SG_IS_DETACHING(sdp) test_bit(SG_FDEV_DETACHING, (sdp)->fdev_bm)
>> +#define SG_HAVE_EXCLUDE(sdp) test_bit(SG_FDEV_EXCLUDE, (sdp)->fdev_bm)
>> +
>> /*
>> * Kernel needs to be built with CONFIG_SCSI_LOGGING to see log messages.
>> * 'depth' is a number between 1 (most severe) and 7 (most noisy, most
>> @@ -273,26 +279,26 @@ sg_wait_open_event(struct sg_device *sdp, bool o_excl)
>> while (sdp->open_cnt > 0) {
>> mutex_unlock(&sdp->open_rel_lock);
>> retval = wait_event_interruptible(sdp->open_wait,
>> - (atomic_read(&sdp->detaching) ||
>> + (SG_IS_DETACHING(sdp) ||
>> !sdp->open_cnt));
>> mutex_lock(&sdp->open_rel_lock);
>>
>> if (retval) /* -ERESTARTSYS */
>> return retval;
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> }
>> } else {
>> - while (sdp->exclude) {
>> + while (SG_HAVE_EXCLUDE(sdp)) {
>> mutex_unlock(&sdp->open_rel_lock);
>> retval = wait_event_interruptible(sdp->open_wait,
>> - (atomic_read(&sdp->detaching) ||
>> - !sdp->exclude));
>> + (SG_IS_DETACHING(sdp) ||
>> + !SG_HAVE_EXCLUDE(sdp)));
>> mutex_lock(&sdp->open_rel_lock);
>>
>> if (retval) /* -ERESTARTSYS */
>> return retval;
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> }
>> }
>> @@ -354,7 +360,7 @@ sg_open(struct inode *inode, struct file *filp)
>> goto error_mutex_locked;
>> }
>> } else {
>> - if (sdp->exclude) {
>> + if (SG_HAVE_EXCLUDE(sdp)) {
>> retval = -EBUSY;
>> goto error_mutex_locked;
>> }
>> @@ -367,10 +373,10 @@ sg_open(struct inode *inode, struct file *filp)
>>
>> /* N.B. at this point we are holding the open_rel_lock */
>> if (o_excl)
>> - sdp->exclude = true;
>> + set_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm);
>>
>> if (sdp->open_cnt < 1) { /* no existing opens */
>> - sdp->sgdebug = 0;
>> + clear_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm);
>> q = sdp->device->request_queue;
>> sdp->sg_tablesize = queue_max_segments(q);
>> }
>> @@ -393,8 +399,8 @@ sg_open(struct inode *inode, struct file *filp)
>> return retval;
>>
>> out_undo:
>> - if (o_excl) {
>> - sdp->exclude = false; /* undo if error */
>> + if (o_excl) { /* undo if error */
>> + clear_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm);
>> wake_up_interruptible(&sdp->open_wait);
>> }
>> error_mutex_locked:
>> @@ -428,12 +434,10 @@ sg_release(struct inode *inode, struct file *filp)
>>
>> /* possibly many open()s waiting on exlude clearing, start many;
>> * only open(O_EXCL)s wait on 0==open_cnt so only start one */
>> - if (sdp->exclude) {
>> - sdp->exclude = false;
>> + if (test_and_clear_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm))
>> wake_up_interruptible_all(&sdp->open_wait);
>> - } else if (0 == sdp->open_cnt) {
>> + else if (sdp->open_cnt == 0)
>> wake_up_interruptible(&sdp->open_wait);
>> - }
>> mutex_unlock(&sdp->open_rel_lock);
>> return 0;
>> }
>> @@ -467,7 +471,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
>> SG_LOG(3, sfp, "%s: write(3rd arg) count=%d\n", __func__, (int)count);
>> if (!sdp)
>> return -ENXIO;
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> if (!((filp->f_flags & O_NONBLOCK) ||
>> scsi_block_when_processing_errors(sdp->device)))
>> @@ -666,7 +670,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
>> sg_remove_request(sfp, srp);
>> return k; /* probably out of space --> ENOMEM */
>> }
>> - if (atomic_read(&sdp->detaching)) {
>> + if (SG_IS_DETACHING(sdp)) {
>> if (srp->bio) {
>> scsi_req_free_cmd(scsi_req(srp->rq));
>> blk_put_request(srp->rq);
>> @@ -831,7 +835,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
>> }
>> srp = sg_get_rq_mark(sfp, req_pack_id);
>> if (!srp) { /* now wait on packet to arrive */
>> - if (atomic_read(&sdp->detaching)) {
>> + if (SG_IS_DETACHING(sdp)) {
>> retval = -ENODEV;
>> goto free_old_hdr;
>> }
>> @@ -840,9 +844,9 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
>> goto free_old_hdr;
>> }
>> retval = wait_event_interruptible(sfp->read_wait,
>> - (atomic_read(&sdp->detaching) ||
>> + (SG_IS_DETACHING(sdp) ||
>> (srp = sg_get_rq_mark(sfp, req_pack_id))));
>> - if (atomic_read(&sdp->detaching)) {
>> + if (SG_IS_DETACHING(sdp)) {
>> retval = -ENODEV;
>> goto free_old_hdr;
>> }
>> @@ -997,7 +1001,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
>>
>> switch (cmd_in) {
>> case SG_IO:
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> if (!scsi_block_when_processing_errors(sdp->device))
>> return -ENXIO;
>> @@ -1008,8 +1012,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
>> if (result < 0)
>> return result;
>> result = wait_event_interruptible(sfp->read_wait,
>> - (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
>> - if (atomic_read(&sdp->detaching))
>> + (srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> write_lock_irq(&sfp->rq_list_lock);
>> if (srp->done) {
>> @@ -1052,7 +1056,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
>> else {
>> sg_scsi_id_t __user *sg_idp = p;
>>
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> __put_user((int) sdp->device->host->host_no,
>> &sg_idp->host_no);
>> @@ -1176,18 +1180,18 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
>> return result;
>> }
>> case SG_EMULATED_HOST:
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> return put_user(sdp->device->host->hostt->emulated, ip);
>> case SCSI_IOCTL_SEND_COMMAND:
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
>> case SG_SET_DEBUG:
>> result = get_user(val, ip);
>> if (result)
>> return result;
>> - sdp->sgdebug = (char) val;
>> + assign_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm, val);
>> return 0;
>> case BLKSECTGET:
>> return put_user(max_sectors_bytes(sdp->device->request_queue),
>> @@ -1208,7 +1212,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
>> case SCSI_IOCTL_PROBE_HOST:
>> case SG_GET_TRANSFORM:
>> case SG_SCSI_RESET:
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> return -ENODEV;
>> break;
>> default:
>> @@ -1271,7 +1275,7 @@ sg_poll(struct file *filp, poll_table * wait)
>> }
>> read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
>>
>> - if (sfp->parentdp && atomic_read(&sfp->parentdp->detaching)) {
>> + if (sfp->parentdp && SG_IS_DETACHING(sfp->parentdp)) {
>> p_res |= EPOLLHUP;
>> } else if (!sfp->cmd_q) {
>> if (count == 0)
>> @@ -1419,7 +1423,7 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
>> return;
>>
>> sdp = sfp->parentdp;
>> - if (unlikely(atomic_read(&sdp->detaching)))
>> + if (unlikely(SG_IS_DETACHING(sdp)))
>> pr_info("%s: device detaching\n", __func__);
>>
>> sense = req->sense;
>> @@ -1440,9 +1444,9 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
>> srp->header.msg_status = msg_byte(result);
>> srp->header.host_status = host_byte(result);
>> srp->header.driver_status = driver_byte(result);
>> - if ((sdp->sgdebug > 0) &&
>> - ((CHECK_CONDITION == srp->header.masked_status) ||
>> - (COMMAND_TERMINATED == srp->header.masked_status)))
>> + if (test_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm) &&
>> + (srp->header.masked_status == CHECK_CONDITION ||
>> + srp->header.masked_status == COMMAND_TERMINATED))
>> __scsi_print_sense(sdp->device, __func__, sense,
>> SCSI_SENSE_BUFFERSIZE);
>>
>> @@ -1557,7 +1561,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
>> mutex_init(&sdp->open_rel_lock);
>> INIT_LIST_HEAD(&sdp->sfds);
>> init_waitqueue_head(&sdp->open_wait);
>> - atomic_set(&sdp->detaching, 0);
>> + clear_bit(SG_FDEV_DETACHING, sdp->fdev_bm);
>> rwlock_init(&sdp->sfd_lock);
>> sdp->sg_tablesize = queue_max_segments(q);
>> sdp->index = k;
>> @@ -1682,13 +1686,11 @@ sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
>> struct sg_device *sdp = dev_get_drvdata(cl_dev);
>> unsigned long iflags;
>> struct sg_fd *sfp;
>> - int val;
>>
>> if (!sdp)
>> return;
>> - /* want sdp->detaching non-zero as soon as possible */
>> - val = atomic_inc_return(&sdp->detaching);
>> - if (val > 1)
>> + /* set this flag as soon as possible as it could be a surprise */
>> + if (test_and_set_bit(SG_FDEV_DETACHING, sdp->fdev_bm))
>> return; /* only want to do following once per device */
>>
>> SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, sdp->device,
>> @@ -2218,7 +2220,7 @@ sg_add_sfp(struct sg_device *sdp)
>> sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
>> sfp->parentdp = sdp;
>> write_lock_irqsave(&sdp->sfd_lock, iflags);
>> - if (atomic_read(&sdp->detaching)) {
>> + if (SG_IS_DETACHING(sdp)) {
>> write_unlock_irqrestore(&sdp->sfd_lock, iflags);
>> kfree(sfp);
>> return ERR_PTR(-ENODEV);
>> @@ -2315,8 +2317,8 @@ sg_get_dev(int dev)
>> sdp = sg_lookup_dev(dev);
>> if (!sdp)
>> sdp = ERR_PTR(-ENXIO);
>> - else if (atomic_read(&sdp->detaching)) {
>> - /* If sdp->detaching, then the refcount may already be 0, in
>> + else if (SG_IS_DETACHING(sdp)) {
>> + /* If detaching, then the refcount may already be 0, in
>> * which case it would be a bug to do kref_get().
>> */
>> sdp = ERR_PTR(-ENODEV);
>> @@ -2530,8 +2532,7 @@ sg_proc_seq_show_dev(struct seq_file *s, void *v)
>>
>> read_lock_irqsave(&sg_index_lock, iflags);
>> sdp = it ? sg_lookup_dev(it->index) : NULL;
>> - if ((NULL == sdp) || (NULL == sdp->device) ||
>> - (atomic_read(&sdp->detaching)))
>> + if (!sdp || !sdp->device || SG_IS_DETACHING(sdp))
>> seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
>> else {
>> scsidp = sdp->device;
>> @@ -2558,7 +2559,7 @@ sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
>> read_lock_irqsave(&sg_index_lock, iflags);
>> sdp = it ? sg_lookup_dev(it->index) : NULL;
>> scsidp = sdp ? sdp->device : NULL;
>> - if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
>> + if (sdp && scsidp && !SG_IS_DETACHING(sdp))
>> seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
>> scsidp->vendor, scsidp->model, scsidp->rev);
>> else
>> @@ -2650,7 +2651,7 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
>> read_lock(&sdp->sfd_lock);
>> if (!list_empty(&sdp->sfds)) {
>> seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
>> - if (atomic_read(&sdp->detaching))
>> + if (SG_IS_DETACHING(sdp))
>> seq_puts(s, "detaching pending close ");
>> else if (sdp->device) {
>> struct scsi_device *scsidp = sdp->device;
>> @@ -2662,7 +2663,8 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
>> scsidp->host->hostt->emulated);
>> }
>> seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
>> - sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
>> + sdp->sg_tablesize, SG_HAVE_EXCLUDE(sdp),
>> + sdp->open_cnt);
>> sg_proc_debug_helper(s, sdp);
>> }
>> read_unlock(&sdp->sfd_lock);
>>
> One thing to keep in mind here is that 'set_bit()' is not atomic; it
> needs to be followed by a memory barrier or being replaced by
> test_and_set_bit() if possible.
> Please audit the code if that poses a problem.
Hi,
set_bit() and friends are documented in Documentation/atomic_bitops.txt
so it would be surprising if they were not _atomic_ . There are variants
documented in that file that _maybe_ non-atomic, they are the one that
start with __ such as __set_bit().
So what I believe Documentation/atomic_bitops.txt is trying to say (in
a sloppy kind of way) is that set_bit() and clear_bit() have _relaxed_
memory order. C/C++ standards (from 2011 onwards) have 6 memory orders:
- relaxed [no memory order guarantees]
- consume [C++17 says "please don't use"!]
- acquire
- release
- acquire-release
- sequentially consistent ["cst"]
That list is from weakest to strongest. C/C++ default everything they
can to "cst" as it requires the least thinking and is therefore the
safest, but has the highest runtime overhead (depending somewhat on
the platform).
Linux adds a few wrinkles to the above as C/C++ are only considering
threads while Linux additionally has ISRs, DMA, memory-mapped IO and
the like to consider.
From what I have read in the Documentation directories, most
descriptions are written by gifted and un-gifted amateurs, apart from
one amazing exception: Documentation/memory-barriers.txt . Now they
are professions and the authors put their names, in full, at the
top which IMO is always a good sign.
Back to the review at hand, if set_bit() has relaxed memory order
and needs to be seen by another thread (or ISR/bottom half) then it
is relying on a following atomic operation that has stronger memory
ordering guarantees (than relaxed). In my code I tend to use
__set_bit() and __clear_bit() when a file descriptor or request object
is being created, as no other thread should know of its existence at
that time.
Doug Gilbert
Reference: C++ Concurrency in action, Second edition, Anthony Williams
[As the C11 and C++11 concurrency subcommittees were "manned" by the
same folks, they tried to make their memory models as compatible as
possible.]
^ permalink raw reply [flat|nested] 43+ messages in thread* Re: [PATCH v5 05/23] sg: bitops in sg_device
2019-10-21 13:22 ` Douglas Gilbert
@ 2019-10-21 13:38 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-21 13:38 UTC (permalink / raw)
To: dgilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/21/19 3:22 PM, Douglas Gilbert wrote:
> On 2019-10-18 6:05 a.m., Hannes Reinecke wrote:
[ .. ]
>> One thing to keep in mind here is that 'set_bit()' is not atomic; it
>> needs to be followed by a memory barrier or being replaced by
>> test_and_set_bit() if possible.
>> Please audit the code if that poses a problem.
>
> Hi,
> set_bit() and friends are documented in Documentation/atomic_bitops.txt
> so it would be surprising if they were not _atomic_ . There are variants
> documented in that file that _maybe_ non-atomic, they are the one that
> start with __ such as __set_bit().
>
> So what I believe Documentation/atomic_bitops.txt is trying to say (in
> a sloppy kind of way) is that set_bit() and clear_bit() have _relaxed_
> memory order. C/C++ standards (from 2011 onwards) have 6 memory orders:
> - relaxed [no memory order guarantees]
> - consume [C++17 says "please don't use"!]
> - acquire
> - release
> - acquire-release
> - sequentially consistent ["cst"]
>
> That list is from weakest to strongest. C/C++ default everything they
> can to "cst" as it requires the least thinking and is therefore the
> safest, but has the highest runtime overhead (depending somewhat on
> the platform).
>
> Linux adds a few wrinkles to the above as C/C++ are only considering
> threads while Linux additionally has ISRs, DMA, memory-mapped IO and
> the like to consider.
>
> From what I have read in the Documentation directories, most
> descriptions are written by gifted and un-gifted amateurs, apart from
> one amazing exception: Documentation/memory-barriers.txt . Now they
> are professions and the authors put their names, in full, at the
> top which IMO is always a good sign.
>
>
> Back to the review at hand, if set_bit() has relaxed memory order
> and needs to be seen by another thread (or ISR/bottom half) then it
> is relying on a following atomic operation that has stronger memory
> ordering guarantees (than relaxed). In my code I tend to use
> __set_bit() and __clear_bit() when a file descriptor or request object
> is being created, as no other thread should know of its existence at
> that time.
>
> Doug Gilbert
>
> Reference: C++ Concurrency in action, Second edition, Anthony Williams
> [As the C11 and C++11 concurrency subcommittees were "manned" by the
> same folks, they tried to make their memory models as compatible as
> possible.]
>
>
That's all I wanted to know. Thanks for the confirmation.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 06/23] sg: make open count an atomic
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (4 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 05/23] sg: bitops in sg_device Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 07/23] sg: move header to uapi section Douglas Gilbert
` (16 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare, Hannes Reinecke
Convert sg_device::open_cnt into an atomic. Also rename
sg_tablesize into the more descriptive max_sgat_elems.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 39 ++++++++++++++++++++-------------------
1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 97ce84f0c51b..9e9470944fe3 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -162,9 +162,9 @@ struct sg_device { /* holds the state of each scsi generic device */
struct mutex open_rel_lock; /* held when in open() or release() */
struct list_head sfds;
rwlock_t sfd_lock; /* protect access to sfd list */
- int sg_tablesize; /* adapter's max scatter-gather table size */
+ int max_sgat_elems; /* adapter's max sgat number of elements */
u32 index; /* device index number */
- int open_cnt; /* count of opens (perhaps < num(sfds) ) */
+ atomic_t open_cnt; /* count of opens (perhaps < num(sfds) ) */
unsigned long fdev_bm[1]; /* see SG_FDEV_* defines above */
struct gendisk *disk;
struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
@@ -276,11 +276,11 @@ sg_wait_open_event(struct sg_device *sdp, bool o_excl)
int retval = 0;
if (o_excl) {
- while (sdp->open_cnt > 0) {
+ while (atomic_read(&sdp->open_cnt) > 0) {
mutex_unlock(&sdp->open_rel_lock);
retval = wait_event_interruptible(sdp->open_wait,
(SG_IS_DETACHING(sdp) ||
- !sdp->open_cnt));
+ atomic_read(&sdp->open_cnt) == 0));
mutex_lock(&sdp->open_rel_lock);
if (retval) /* -ERESTARTSYS */
@@ -355,7 +355,7 @@ sg_open(struct inode *inode, struct file *filp)
mutex_lock(&sdp->open_rel_lock);
if (op_flags & O_NONBLOCK) {
if (o_excl) {
- if (sdp->open_cnt > 0) {
+ if (atomic_read(&sdp->open_cnt) > 0) {
retval = -EBUSY;
goto error_mutex_locked;
}
@@ -375,10 +375,10 @@ sg_open(struct inode *inode, struct file *filp)
if (o_excl)
set_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm);
- if (sdp->open_cnt < 1) { /* no existing opens */
+ if (atomic_read(&sdp->open_cnt) < 1) { /* no existing opens */
clear_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm);
q = sdp->device->request_queue;
- sdp->sg_tablesize = queue_max_segments(q);
+ sdp->max_sgat_elems = queue_max_segments(q);
}
sfp = sg_add_sfp(sdp);
if (IS_ERR(sfp)) {
@@ -387,10 +387,11 @@ sg_open(struct inode *inode, struct file *filp)
}
filp->private_data = sfp;
- sdp->open_cnt++;
+ atomic_inc(&sdp->open_cnt);
mutex_unlock(&sdp->open_rel_lock);
SG_LOG(3, sfp, "%s: minor=%d, op_flags=0x%x; %s count prior=%d%s\n",
- __func__, min_dev, op_flags, "device open", sdp->open_cnt,
+ __func__, min_dev, op_flags, "device open",
+ atomic_read(&sdp->open_cnt),
((op_flags & O_NONBLOCK) ? " O_NONBLOCK" : ""));
retval = 0;
@@ -423,20 +424,20 @@ sg_release(struct inode *inode, struct file *filp)
sfp = filp->private_data;
sdp = sfp->parentdp;
SG_LOG(3, sfp, "%s: device open count prior=%d\n", __func__,
- sdp->open_cnt);
+ atomic_read(&sdp->open_cnt));
if (!sdp)
return -ENXIO;
mutex_lock(&sdp->open_rel_lock);
scsi_autopm_put_device(sdp->device);
kref_put(&sfp->f_ref, sg_remove_sfp);
- sdp->open_cnt--;
+ atomic_dec(&sdp->open_cnt);
/* possibly many open()s waiting on exlude clearing, start many;
* only open(O_EXCL)s wait on 0==open_cnt so only start one */
if (test_and_clear_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm))
wake_up_interruptible_all(&sdp->open_wait);
- else if (sdp->open_cnt == 0)
+ else if (atomic_read(&sdp->open_cnt) == 0)
wake_up_interruptible(&sdp->open_wait);
mutex_unlock(&sdp->open_rel_lock);
return 0;
@@ -1104,7 +1105,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
return put_user(val, ip);
case SG_GET_SG_TABLESIZE:
- return put_user(sdp->sg_tablesize, ip);
+ return put_user(sdp->max_sgat_elems, ip);
case SG_SET_RESERVED_SIZE:
result = get_user(val, ip);
if (result)
@@ -1563,7 +1564,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
init_waitqueue_head(&sdp->open_wait);
clear_bit(SG_FDEV_DETACHING, sdp->fdev_bm);
rwlock_init(&sdp->sfd_lock);
- sdp->sg_tablesize = queue_max_segments(q);
+ sdp->max_sgat_elems = queue_max_segments(q);
sdp->index = k;
kref_init(&sdp->d_ref);
error = 0;
@@ -1958,7 +1959,7 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
int buff_size)
{
int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
- int sg_tablesize = sfp->parentdp->sg_tablesize;
+ int max_sgat_elems = sfp->parentdp->max_sgat_elems;
int blk_size = buff_size, order;
gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
struct sg_device *sdp = sfp->parentdp;
@@ -1973,7 +1974,7 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
blk_size);
/* N.B. ret_sz carried into this block ... */
- mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
+ mx_sc_elems = sg_build_sgat(schp, sfp, max_sgat_elems);
if (mx_sc_elems < 0)
return mx_sc_elems; /* most likely -ENOMEM */
@@ -2662,9 +2663,9 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
scsidp->lun,
scsidp->host->hostt->emulated);
}
- seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
- sdp->sg_tablesize, SG_HAVE_EXCLUDE(sdp),
- sdp->open_cnt);
+ seq_printf(s, " max_sgat_elems=%d excl=%d open_cnt=%d\n",
+ sdp->max_sgat_elems, SG_HAVE_EXCLUDE(sdp),
+ atomic_read(&sdp->open_cnt));
sg_proc_debug_helper(s, sdp);
}
read_unlock(&sdp->sfd_lock);
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 07/23] sg: move header to uapi section
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (5 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 06/23] sg: make open count an atomic Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 08/23] sg: speed sg_poll and sg_get_num_waiting Douglas Gilbert
` (15 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi
Cc: martin.petersen, jejb, hare, Hannes Reinecke, kbuild test robot
Move user interface part of scsi/sg.h into the new header file:
include/uapi/scsi/sg.h . Since scsi/sg.h includes the new header,
other code including scsi/sg.h should not be impacted.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
include/scsi/sg.h | 268 ++-------------------------------
include/uapi/scsi/sg.h | 329 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 338 insertions(+), 259 deletions(-)
create mode 100644 include/uapi/scsi/sg.h
diff --git a/include/scsi/sg.h b/include/scsi/sg.h
index f91bcca604e4..46fc7cbffd78 100644
--- a/include/scsi/sg.h
+++ b/include/scsi/sg.h
@@ -4,271 +4,21 @@
#include <linux/compiler.h>
-/*
- * History:
- * Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user
- * process control of SCSI devices.
- * Development Sponsored by Killy Corp. NY NY
- *
- * Original driver (sg.h):
- * Copyright (C) 1992 Lawrence Foard
- * Version 2 and 3 extensions to driver:
- * Copyright (C) 1998 - 2014 Douglas Gilbert
- *
- * Version: 3.5.36 (20140603)
- * This version is for 2.6 and 3 series kernels.
- *
- * Documentation
- * =============
- * A web site for the SG device driver can be found at:
- * http://sg.danny.cz/sg [alternatively check the MAINTAINERS file]
- * The documentation for the sg version 3 driver can be found at:
- * http://sg.danny.cz/sg/p/sg_v3_ho.html
- * Also see: <kernel_source>/Documentation/scsi/scsi-generic.txt
- *
- * For utility and test programs see: http://sg.danny.cz/sg/sg3_utils.html
- */
-
#ifdef __KERNEL__
extern int sg_big_buff; /* for sysctl */
#endif
+/*
+ * In version 3.9.01 of the sg driver, this file was spilt in two, with the
+ * bulk of the user space interface being placed in the file being included
+ * in the following line.
+ */
+#include <uapi/scsi/sg.h>
-typedef struct sg_iovec /* same structure as used by readv() Linux system */
-{ /* call. It defines one scatter-gather element. */
- void __user *iov_base; /* Starting address */
- size_t iov_len; /* Length in bytes */
-} sg_iovec_t;
-
-
-typedef struct sg_io_hdr
-{
- int interface_id; /* [i] 'S' for SCSI generic (required) */
- int dxfer_direction; /* [i] data transfer direction */
- unsigned char cmd_len; /* [i] SCSI command length */
- unsigned char mx_sb_len; /* [i] max length to write to sbp */
- unsigned short iovec_count; /* [i] 0 implies no scatter gather */
- unsigned int dxfer_len; /* [i] byte count of data transfer */
- void __user *dxferp; /* [i], [*io] points to data transfer memory
- or scatter gather list */
- unsigned char __user *cmdp; /* [i], [*i] points to command to perform */
- void __user *sbp; /* [i], [*o] points to sense_buffer memory */
- unsigned int timeout; /* [i] MAX_UINT->no timeout (unit: millisec) */
- unsigned int flags; /* [i] 0 -> default, see SG_FLAG... */
- int pack_id; /* [i->o] unused internally (normally) */
- void __user * usr_ptr; /* [i->o] unused internally */
- unsigned char status; /* [o] scsi status */
- unsigned char masked_status;/* [o] shifted, masked scsi status */
- unsigned char msg_status; /* [o] messaging level data (optional) */
- unsigned char sb_len_wr; /* [o] byte count actually written to sbp */
- unsigned short host_status; /* [o] errors from host adapter */
- unsigned short driver_status;/* [o] errors from software driver */
- int resid; /* [o] dxfer_len - actual_transferred */
- unsigned int duration; /* [o] time taken by cmd (unit: millisec) */
- unsigned int info; /* [o] auxiliary information */
-} sg_io_hdr_t; /* 64 bytes long (on i386) */
-
-#define SG_INTERFACE_ID_ORIG 'S'
-
-/* Use negative values to flag difference from original sg_header structure */
-#define SG_DXFER_NONE (-1) /* e.g. a SCSI Test Unit Ready command */
-#define SG_DXFER_TO_DEV (-2) /* e.g. a SCSI WRITE command */
-#define SG_DXFER_FROM_DEV (-3) /* e.g. a SCSI READ command */
-#define SG_DXFER_TO_FROM_DEV (-4) /* treated like SG_DXFER_FROM_DEV with the
- additional property than during indirect
- IO the user buffer is copied into the
- kernel buffers before the transfer */
-#define SG_DXFER_UNKNOWN (-5) /* Unknown data direction */
-
-/* following flag values can be "or"-ed together */
-#define SG_FLAG_DIRECT_IO 1 /* default is indirect IO */
-#define SG_FLAG_UNUSED_LUN_INHIBIT 2 /* default is overwrite lun in SCSI */
- /* command block (when <= SCSI_2) */
-#define SG_FLAG_MMAP_IO 4 /* request memory mapped IO */
-#define SG_FLAG_NO_DXFER 0x10000 /* no transfer of kernel buffers to/from */
- /* user space (debug indirect IO) */
-/* defaults:: for sg driver: Q_AT_HEAD; for block layer: Q_AT_TAIL */
-#define SG_FLAG_Q_AT_TAIL 0x10
-#define SG_FLAG_Q_AT_HEAD 0x20
-
-/* following 'info' values are "or"-ed together */
-#define SG_INFO_OK_MASK 0x1
-#define SG_INFO_OK 0x0 /* no sense, host nor driver "noise" */
-#define SG_INFO_CHECK 0x1 /* something abnormal happened */
-
-#define SG_INFO_DIRECT_IO_MASK 0x6
-#define SG_INFO_INDIRECT_IO 0x0 /* data xfer via kernel buffers (or no xfer) */
-#define SG_INFO_DIRECT_IO 0x2 /* direct IO requested and performed */
-#define SG_INFO_MIXED_IO 0x4 /* part direct, part indirect IO */
-
-
-typedef struct sg_scsi_id { /* used by SG_GET_SCSI_ID ioctl() */
- int host_no; /* as in "scsi<n>" where 'n' is one of 0, 1, 2 etc */
- int channel;
- int scsi_id; /* scsi id of target device */
- int lun;
- int scsi_type; /* TYPE_... defined in scsi/scsi.h */
- short h_cmd_per_lun;/* host (adapter) maximum commands per lun */
- short d_queue_depth;/* device (or adapter) maximum queue length */
- int unused[2]; /* probably find a good use, set 0 for now */
-} sg_scsi_id_t; /* 32 bytes long on i386 */
-
-typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
- char req_state; /* 0 -> not used, 1 -> written, 2 -> ready to read */
- char orphan; /* 0 -> normal request, 1 -> from interruped SG_IO */
- char sg_io_owned; /* 0 -> complete with read(), 1 -> owned by SG_IO */
- char problem; /* 0 -> no problem detected, 1 -> error to report */
- int pack_id; /* pack_id associated with request */
- void __user *usr_ptr; /* user provided pointer (in new interface) */
- unsigned int duration; /* millisecs elapsed since written (req_state==1)
- or request duration (req_state==2) */
- int unused;
-} sg_req_info_t; /* 20 bytes long on i386 */
-
-
-/* IOCTLs: Those ioctls that are relevant to the SG 3.x drivers follow.
- [Those that only apply to the SG 2.x drivers are at the end of the file.]
- (_GET_s yield result via 'int *' 3rd argument unless otherwise indicated) */
-
-#define SG_EMULATED_HOST 0x2203 /* true for emulated host adapter (ATAPI) */
-
-/* Used to configure SCSI command transformation layer for ATAPI devices */
-/* Only supported by the ide-scsi driver */
-#define SG_SET_TRANSFORM 0x2204 /* N.B. 3rd arg is not pointer but value: */
- /* 3rd arg = 0 to disable transform, 1 to enable it */
-#define SG_GET_TRANSFORM 0x2205
-
-#define SG_SET_RESERVED_SIZE 0x2275 /* request a new reserved buffer size */
-#define SG_GET_RESERVED_SIZE 0x2272 /* actual size of reserved buffer */
-
-/* The following ioctl has a 'sg_scsi_id_t *' object as its 3rd argument. */
-#define SG_GET_SCSI_ID 0x2276 /* Yields fd's bus, chan, dev, lun + type */
-/* SCSI id information can also be obtained from SCSI_IOCTL_GET_IDLUN */
-
-/* Override host setting and always DMA using low memory ( <16MB on i386) */
-#define SG_SET_FORCE_LOW_DMA 0x2279 /* 0-> use adapter setting, 1-> force */
-#define SG_GET_LOW_DMA 0x227a /* 0-> use all ram for dma; 1-> low dma ram */
-
-/* When SG_SET_FORCE_PACK_ID set to 1, pack_id is input to read() which
- tries to fetch a packet with a matching pack_id, waits, or returns EAGAIN.
- If pack_id is -1 then read oldest waiting. When ...FORCE_PACK_ID set to 0
- then pack_id ignored by read() and oldest readable fetched. */
-#define SG_SET_FORCE_PACK_ID 0x227b
-#define SG_GET_PACK_ID 0x227c /* Yields oldest readable pack_id (or -1) */
-
-#define SG_GET_NUM_WAITING 0x227d /* Number of commands awaiting read() */
-
-/* Yields max scatter gather tablesize allowed by current host adapter */
-#define SG_GET_SG_TABLESIZE 0x227F /* 0 implies can't do scatter gather */
-
-#define SG_GET_VERSION_NUM 0x2282 /* Example: version 2.1.34 yields 20134 */
-
-/* Returns -EBUSY if occupied. 3rd argument pointer to int (see next) */
-#define SG_SCSI_RESET 0x2284
-/* Associated values that can be given to SG_SCSI_RESET follow.
- * SG_SCSI_RESET_NO_ESCALATE may be OR-ed to the _DEVICE, _TARGET, _BUS
- * or _HOST reset value so only that action is attempted. */
-#define SG_SCSI_RESET_NOTHING 0
-#define SG_SCSI_RESET_DEVICE 1
-#define SG_SCSI_RESET_BUS 2
-#define SG_SCSI_RESET_HOST 3
-#define SG_SCSI_RESET_TARGET 4
-#define SG_SCSI_RESET_NO_ESCALATE 0x100
-
-/* synchronous SCSI command ioctl, (only in version 3 interface) */
-#define SG_IO 0x2285 /* similar effect as write() followed by read() */
-
-#define SG_GET_REQUEST_TABLE 0x2286 /* yields table of active requests */
-
-/* How to treat EINTR during SG_IO ioctl(), only in SG 3.x series */
-#define SG_SET_KEEP_ORPHAN 0x2287 /* 1 -> hold for read(), 0 -> drop (def) */
-#define SG_GET_KEEP_ORPHAN 0x2288
-
-/* yields scsi midlevel's access_count for this SCSI device */
-#define SG_GET_ACCESS_COUNT 0x2289
-
-
-#define SG_SCATTER_SZ (8 * 4096)
-/* Largest size (in bytes) a single scatter-gather list element can have.
- The value used by the driver is 'max(SG_SCATTER_SZ, PAGE_SIZE)'.
- This value should be a power of 2 (and may be rounded up internally).
- If scatter-gather is not supported by adapter then this value is the
- largest data block that can be read/written by a single scsi command. */
-
-#define SG_DEFAULT_RETRIES 0
-
-/* Defaults, commented if they differ from original sg driver */
-#define SG_DEF_FORCE_PACK_ID 0
-#define SG_DEF_KEEP_ORPHAN 0
-#define SG_DEF_RESERVED_SIZE SG_SCATTER_SZ /* load time option */
-
-/* maximum outstanding requests, write() yields EDOM if exceeded */
-#define SG_MAX_QUEUE 16
-
-#define SG_BIG_BUFF SG_DEF_RESERVED_SIZE /* for backward compatibility */
-
-/* Alternate style type names, "..._t" variants preferred */
-typedef struct sg_io_hdr Sg_io_hdr;
-typedef struct sg_io_vec Sg_io_vec;
-typedef struct sg_scsi_id Sg_scsi_id;
-typedef struct sg_req_info Sg_req_info;
-
-
-/* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */
-/* The older SG interface based on the 'sg_header' structure follows. */
-/* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
-
-#define SG_MAX_SENSE 16 /* this only applies to the sg_header interface */
-
-struct sg_header
-{
- int pack_len; /* [o] reply_len (ie useless), ignored as input */
- int reply_len; /* [i] max length of expected reply (inc. sg_header) */
- int pack_id; /* [io] id number of packet (use ints >= 0) */
- int result; /* [o] 0==ok, else (+ve) Unix errno (best ignored) */
- unsigned int twelve_byte:1;
- /* [i] Force 12 byte command length for group 6 & 7 commands */
- unsigned int target_status:5; /* [o] scsi status from target */
- unsigned int host_status:8; /* [o] host status (see "DID" codes) */
- unsigned int driver_status:8; /* [o] driver status+suggestion */
- unsigned int other_flags:10; /* unused */
- unsigned char sense_buffer[SG_MAX_SENSE]; /* [o] Output in 3 cases:
- when target_status is CHECK_CONDITION or
- when target_status is COMMAND_TERMINATED or
- when (driver_status & DRIVER_SENSE) is true. */
-}; /* This structure is 36 bytes long on i386 */
-
-
-/* IOCTLs: The following are not required (or ignored) when the sg_io_hdr_t
- interface is used. They are kept for backward compatibility with
- the original and version 2 drivers. */
-
-#define SG_SET_TIMEOUT 0x2201 /* unit: jiffies (10ms on i386) */
-#define SG_GET_TIMEOUT 0x2202 /* yield timeout as _return_ value */
-
-/* Get/set command queuing state per fd (default is SG_DEF_COMMAND_Q.
- Each time a sg_io_hdr_t object is seen on this file descriptor, this
- command queuing flag is set on (overriding the previous setting). */
-#define SG_GET_COMMAND_Q 0x2270 /* Yields 0 (queuing off) or 1 (on) */
-#define SG_SET_COMMAND_Q 0x2271 /* Change queuing state with 0 or 1 */
-
-/* Turn on/off error sense trace (1 and 0 respectively, default is off).
- Try using: "# cat /proc/scsi/sg/debug" instead in the v3 driver */
-#define SG_SET_DEBUG 0x227e /* 0 -> turn off debug */
-
-#define SG_NEXT_CMD_LEN 0x2283 /* override SCSI command length with given
- number on the next write() on this file descriptor */
-
-
-/* Defaults, commented if they differ from original sg driver */
#ifdef __KERNEL__
-#define SG_DEFAULT_TIMEOUT_USER (60*USER_HZ) /* HZ == 'jiffies in 1 second' */
-#else
-#define SG_DEFAULT_TIMEOUT (60*HZ) /* HZ == 'jiffies in 1 second' */
+#define SG_DEFAULT_TIMEOUT_USER (60*USER_HZ) /* HZ == 'jiffies in 1 second' */
#endif
-#define SG_DEF_COMMAND_Q 0 /* command queuing is always on when
- the new interface is used */
-#define SG_DEF_UNDERRUN_FLAG 0
+#undef SG_DEFAULT_TIMEOUT /* because of conflicting define in sg.c */
-#endif
+#endif /* end of ifndef _SCSI_GENERIC_H guard */
diff --git a/include/uapi/scsi/sg.h b/include/uapi/scsi/sg.h
new file mode 100644
index 000000000000..595d02b9cfd4
--- /dev/null
+++ b/include/uapi/scsi/sg.h
@@ -0,0 +1,329 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_SCSI_SG_H
+#define _UAPI_SCSI_SG_H
+
+/*
+ * History:
+ * Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user
+ * process control of SCSI devices.
+ * Development Sponsored by Killy Corp. NY NY
+ *
+ * Original driver (sg.h):
+ * Copyright (C) 1992 Lawrence Foard
+ *
+ * Later extensions (versions 2, 3 and 4) to driver:
+ * Copyright (C) 1998 - 2018 Douglas Gilbert
+ *
+ * Version 4.0.11 (20190502)
+ * This version is for Linux 4 and 5 series kernels.
+ *
+ * Documentation
+ * =============
+ * A web site for the SG device driver can be found at:
+ * http://sg.danny.cz/sg [alternatively check the MAINTAINERS file]
+ * The documentation for the sg version 3 driver can be found at:
+ * http://sg.danny.cz/sg/p/sg_v3_ho.html
+ * Also see: <kernel_source>/Documentation/scsi/scsi-generic.txt
+ *
+ * For utility and test programs see: http://sg.danny.cz/sg/sg3_utils.html
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+
+/* bsg.h contains the sg v4 user space interface structure (sg_io_v4). */
+#include <linux/bsg.h>
+
+/*
+ * Same structure as used by readv() call. It defines one scatter-gather
+ * element. "Scatter-gather" is abbreviated to "sgat" in this driver to
+ * avoid confusion with this driver's name.
+ */
+typedef struct sg_iovec {
+ void __user *iov_base; /* Starting address (of a byte) */
+ size_t iov_len; /* Length in bytes */
+} sg_iovec_t;
+
+
+typedef struct sg_io_hdr {
+ int interface_id; /* [i] 'S' for SCSI generic (required) */
+ int dxfer_direction; /* [i] data transfer direction */
+ unsigned char cmd_len; /* [i] SCSI command length */
+ unsigned char mx_sb_len;/* [i] max length to write to sbp */
+ unsigned short iovec_count; /* [i] 0 implies no sgat list */
+ unsigned int dxfer_len; /* [i] byte count of data transfer */
+ /* dxferp points to data transfer memory or scatter gather list */
+ void __user *dxferp; /* [i], [*io] */
+ unsigned char __user *cmdp;/* [i], [*i] points to command to perform */
+ void __user *sbp; /* [i], [*o] points to sense_buffer memory */
+ unsigned int timeout; /* [i] MAX_UINT->no timeout (unit: millisec) */
+ unsigned int flags; /* [i] 0 -> default, see SG_FLAG... */
+ int pack_id; /* [i->o] unused internally (normally) */
+ void __user *usr_ptr; /* [i->o] unused internally */
+ unsigned char status; /* [o] scsi status */
+ unsigned char masked_status;/* [o] shifted, masked scsi status */
+ unsigned char msg_status;/* [o] messaging level data (optional) */
+ unsigned char sb_len_wr; /* [o] byte count actually written to sbp */
+ unsigned short host_status; /* [o] errors from host adapter */
+ unsigned short driver_status;/* [o] errors from software driver */
+ int resid; /* [o] dxfer_len - actual_transferred */
+ /* unit may be nanoseconds after SG_SET_GET_EXTENDED ioctl use */
+ unsigned int duration; /* [o] time taken by cmd (unit: millisec) */
+ unsigned int info; /* [o] auxiliary information */
+} sg_io_hdr_t;
+
+#define SG_INTERFACE_ID_ORIG 'S'
+
+/* Use negative values to flag difference from original sg_header structure */
+#define SG_DXFER_NONE (-1) /* e.g. a SCSI Test Unit Ready command */
+#define SG_DXFER_TO_DEV (-2) /* data-out buffer e.g. SCSI WRITE command */
+#define SG_DXFER_FROM_DEV (-3) /* data-in buffer e.g. SCSI READ command */
+/*
+ * SG_DXFER_TO_FROM_DEV is treated like SG_DXFER_FROM_DEV with the additional
+ * property than during indirect IO the user buffer is copied into the kernel
+ * buffers _before_ the transfer from the device takes place. Useful if short
+ * DMA transfers (less than requested) are not reported (e.g. resid always 0).
+ */
+#define SG_DXFER_TO_FROM_DEV (-4)
+#define SG_DXFER_UNKNOWN (-5) /* Unknown data direction, do not use */
+
+/* following flag values can be OR-ed together in v3::flags or v4::flags */
+#define SG_FLAG_DIRECT_IO 1 /* default is indirect IO */
+/* SG_FLAG_UNUSED_LUN_INHIBIT is ignored in sg v4 driver */
+#define SG_FLAG_UNUSED_LUN_INHIBIT 2 /* ignored, was LUN overwrite in cdb */
+#define SG_FLAG_MMAP_IO 4 /* request memory mapped IO */
+/* no transfer of kernel buffers to/from user space; used for sharing */
+#define SG_FLAG_NO_DXFER 0x10000
+/* defaults: for sg driver (v3_v4): Q_AT_HEAD; for block layer: Q_AT_TAIL */
+#define SG_FLAG_Q_AT_TAIL 0x10
+#define SG_FLAG_Q_AT_HEAD 0x20
+
+/* Output (potentially OR-ed together) in v3::info or v4::info field */
+#define SG_INFO_OK_MASK 0x1
+#define SG_INFO_OK 0x0 /* no sense, host nor driver "noise" */
+#define SG_INFO_CHECK 0x1 /* something abnormal happened */
+
+#define SG_INFO_DIRECT_IO_MASK 0x6
+#define SG_INFO_INDIRECT_IO 0x0 /* data xfer via kernel buffers (or no xfer) */
+#define SG_INFO_DIRECT_IO 0x2 /* direct IO requested and performed */
+#define SG_INFO_MIXED_IO 0x4 /* not used, always 0 */
+#define SG_INFO_DEVICE_DETACHING 0x8 /* completed successfully but ... */
+#define SG_INFO_ABORTED 0x10 /* this command has been aborted */
+#define SG_INFO_MRQ_FINI 0x20 /* marks multi-reqs that have finished */
+
+/*
+ * Pointer to object of this structure filled by ioctl(SG_GET_SCSI_ID). Last
+ * field changed in v4 driver, was 'int unused[2]' so remains the same size.
+ */
+typedef struct sg_scsi_id {
+ int host_no; /* as in "scsi<n>" where 'n' is one of 0, 1, 2 etc */
+ int channel;
+ int scsi_id; /* scsi id of target device */
+ int lun; /* lower 32 bits of internal 64 bit integer */
+ int scsi_type; /* TYPE_... defined in scsi/scsi.h */
+ short h_cmd_per_lun;/* host (adapter) maximum commands per lun */
+ short d_queue_depth;/* device (or adapter) maximum queue length */
+ int unused[2];
+} sg_scsi_id_t;
+
+/* For backward compatibility v4 driver yields at most SG_MAX_QUEUE of these */
+typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
+ char req_state; /* See 'enum sg_rq_state' definition in v4 driver */
+ char orphan; /* 0 -> normal request, 1 -> from interrupted SG_IO */
+ /* sg_io_owned set imples synchronous, clear implies asynchronous */
+ char sg_io_owned;/* 0 -> complete with read(), 1 -> owned by SG_IO */
+ char problem; /* 0 -> no problem detected, 1 -> error to report */
+ /* If SG_CTL_FLAGM_TAG_FOR_PACK_ID set on fd then next field is tag */
+ int pack_id; /* pack_id, in v4 driver may be tag instead */
+ void __user *usr_ptr; /* user provided pointer in v3+v4 interface */
+ unsigned int duration;
+ int unused;
+} sg_req_info_t;
+
+/*
+ * IOCTLs: Those ioctls that are relevant to the SG 3.x drivers follow.
+ * [Those that only apply to the SG 2.x drivers are at the end of the file.]
+ * (_GET_s yield result via 'int *' 3rd argument unless otherwise indicated)
+ */
+
+#define SG_EMULATED_HOST 0x2203 /* true for emulated host adapter (ATAPI) */
+
+/*
+ * Used to configure SCSI command transformation layer for ATAPI devices.
+ * Only supported by the ide-scsi driver. 20181014 No longer supported, this
+ * driver passes them to the mid-level which returns a EINVAL (22) errno.
+ *
+ * Original note: N.B. 3rd arg is not pointer but value: 3rd arg = 0 to
+ * disable transform, 1 to enable it
+ */
+#define SG_SET_TRANSFORM 0x2204
+#define SG_GET_TRANSFORM 0x2205
+
+#define SG_SET_RESERVED_SIZE 0x2275 /* request new reserved buffer size */
+#define SG_GET_RESERVED_SIZE 0x2272 /* actual size of reserved buffer */
+
+/* The following ioctl has a 'sg_scsi_id_t *' object as its 3rd argument. */
+#define SG_GET_SCSI_ID 0x2276 /* Yields fd's bus, chan, dev, lun + type */
+/* SCSI id information can also be obtained from SCSI_IOCTL_GET_IDLUN */
+
+/* Override host setting and always DMA using low memory ( <16MB on i386) */
+#define SG_SET_FORCE_LOW_DMA 0x2279 /* 0-> use adapter setting, 1-> force */
+#define SG_GET_LOW_DMA 0x227a /* 0-> use all ram for dma; 1-> low dma ram */
+
+/*
+ * When SG_SET_FORCE_PACK_ID set to 1, pack_id (or tag) is input to read() or
+ * ioctl(SG_IO_RECEIVE). These functions wait until matching packet (request/
+ * command) is finished but they will return with EAGAIN quickly if the file
+ * descriptor was opened O_NONBLOCK or (in v4) if SGV4_FLAG_IMMED is given.
+ * The tag is used when SG_CTL_FLAGM_TAG_FOR_PACK_ID is set on the parent
+ * file descriptor (default: use pack_id). If pack_id or tag is -1 then read
+ * oldest waiting and this is the same action as when FORCE_PACK_ID is
+ * clear on the parent file descriptor. In the v4 interface the pack_id is
+ * placed the in sg_io_v4::request_extra field .
+ */
+#define SG_SET_FORCE_PACK_ID 0x227b /* pack_id or in v4 can be tag */
+#define SG_GET_PACK_ID 0x227c /* Yields oldest readable pack_id/tag, or -1 */
+
+#define SG_GET_NUM_WAITING 0x227d /* Number of commands awaiting read() */
+
+/* Yields max scatter gather tablesize allowed by current host adapter */
+#define SG_GET_SG_TABLESIZE 0x227F /* 0 implies can't do scatter gather */
+
+/*
+ * Integer form of version number: [x]xyyzz where [x] empty when x=0 .
+ * String form of version number: "[x]x.[y]y.zz"
+ */
+#define SG_GET_VERSION_NUM 0x2282 /* Example: version "2.1.34" yields 20134 */
+
+/* Returns -EBUSY if occupied. 3rd argument pointer to int (see next) */
+#define SG_SCSI_RESET 0x2284
+/*
+ * Associated values that can be given to SG_SCSI_RESET follow.
+ * SG_SCSI_RESET_NO_ESCALATE may be OR-ed to the _DEVICE, _TARGET, _BUS
+ * or _HOST reset value so only that action is attempted.
+ */
+#define SG_SCSI_RESET_NOTHING 0
+#define SG_SCSI_RESET_DEVICE 1
+#define SG_SCSI_RESET_BUS 2
+#define SG_SCSI_RESET_HOST 3
+#define SG_SCSI_RESET_TARGET 4
+#define SG_SCSI_RESET_NO_ESCALATE 0x100
+
+/* synchronous SCSI command ioctl, (for version 3 and 4 interface) */
+#define SG_IO 0x2285 /* similar effect as write() followed by read() */
+
+#define SG_GET_REQUEST_TABLE 0x2286 /* yields table of active requests */
+
+/* How to treat EINTR during SG_IO ioctl(), only in sg v3 and v4 driver */
+#define SG_SET_KEEP_ORPHAN 0x2287 /* 1 -> hold for read(), 0 -> drop (def) */
+#define SG_GET_KEEP_ORPHAN 0x2288
+
+/*
+ * Yields scsi midlevel's access_count for this SCSI device. 20181014 No
+ * longer available, always yields 1.
+ */
+#define SG_GET_ACCESS_COUNT 0x2289
+
+
+/*
+ * Default size (in bytes) a single scatter-gather list element can have.
+ * The value used by the driver is 'max(SG_SCATTER_SZ, PAGE_SIZE)'. This
+ * value should be a power of 2 (and may be rounded up internally). In the
+ * v4 driver this can be changed by ioctl(SG_SET_GET_EXTENDED{SGAT_ELEM_SZ}).
+ */
+#define SG_SCATTER_SZ (8 * 4096)
+
+/* sg driver users' code should handle retries (e.g. from Unit Attentions) */
+#define SG_DEFAULT_RETRIES 0
+
+/* Defaults, commented if they differ from original sg driver */
+#define SG_DEF_FORCE_PACK_ID 0
+#define SG_DEF_KEEP_ORPHAN 0
+#define SG_DEF_RESERVED_SIZE SG_SCATTER_SZ /* load time option */
+
+/*
+ * Maximum outstanding requests (i.e write()s without corresponding read()s)
+ * yields EDOM from write() if exceeded. This limit only applies prior to
+ * version 3.9 . It is still used as a maximum number of sg_req_info objects
+ * that are returned from the SG_GET_REQUEST_TABLE ioctl.
+ */
+#define SG_MAX_QUEUE 16
+
+#define SG_BIG_BUFF SG_DEF_RESERVED_SIZE /* for backward compatibility */
+
+/*
+ * Alternate style type names, "..._t" variants (as found in the
+ * 'typedef struct * {};' definitions above) are preferred to these:
+ */
+typedef struct sg_io_hdr Sg_io_hdr;
+typedef struct sg_io_vec Sg_io_vec;
+typedef struct sg_scsi_id Sg_scsi_id;
+typedef struct sg_req_info Sg_req_info;
+
+
+/* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */
+/* The v1+v2 SG interface based on the 'sg_header' structure follows. */
+/* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
+
+#define SG_MAX_SENSE 16 /* this only applies to the sg_header interface */
+
+struct sg_header {
+ int pack_len; /* [o] reply_len (ie useless), ignored as input */
+ int reply_len; /* [i] max length of expected reply (inc. sg_header) */
+ int pack_id; /* [io] id number of packet (use ints >= 0) */
+ int result; /* [o] 0==ok, else (+ve) Unix errno (best ignored) */
+ unsigned int twelve_byte:1;
+ /* [i] Force 12 byte command length for group 6 & 7 commands */
+ unsigned int target_status:5; /* [o] scsi status from target */
+ unsigned int host_status:8; /* [o] host status (see "DID" codes) */
+ unsigned int driver_status:8; /* [o] driver status+suggestion */
+ unsigned int other_flags:10; /* unused */
+ unsigned char sense_buffer[SG_MAX_SENSE];
+ /*
+ * [o] Output in 3 cases:
+ * when target_status is CHECK_CONDITION or
+ * when target_status is COMMAND_TERMINATED or
+ * when (driver_status & DRIVER_SENSE) is true.
+ */
+};
+
+/*
+ * IOCTLs: The following are not required (or ignored) when the v3 or v4
+ * interface is used as those structures contain a timeout field. These
+ * ioctls are kept for backward compatibility with v1+v2 interfaces.
+ */
+
+#define SG_SET_TIMEOUT 0x2201 /* unit: (user space) jiffies */
+#define SG_GET_TIMEOUT 0x2202 /* yield timeout as _return_ value */
+
+/*
+ * Get/set command queuing state per fd (default is SG_DEF_COMMAND_Q.
+ * Each time a sg_io_hdr_t object is seen on this file descriptor, this
+ * command queuing flag is set on (overriding the previous setting).
+ * This setting defaults to 0 (i.e. no queuing) but gets set the first
+ * time that fd sees a v3 or v4 interface request.
+ */
+#define SG_GET_COMMAND_Q 0x2270 /* Yields 0 (queuing off) or 1 (on) */
+#define SG_SET_COMMAND_Q 0x2271 /* Change queuing state with 0 or 1 */
+
+/*
+ * Turn on/off error sense trace (1 and 0 respectively, default is off).
+ * Try using: "# cat /proc/scsi/sg/debug" instead in the v3 driver
+ */
+#define SG_SET_DEBUG 0x227e /* 0 -> turn off debug */
+
+/*
+ * override SCSI command length with given number on the next write() on
+ * this file descriptor (v1 and v2 interface only)
+ */
+#define SG_NEXT_CMD_LEN 0x2283
+
+/* command queuing is always on when the v3 or v4 interface is used */
+#define SG_DEF_COMMAND_Q 0
+
+#define SG_DEF_UNDERRUN_FLAG 0
+
+/* If the timeout value in the v3_v4 interfaces is 0, this value is used */
+#define SG_DEFAULT_TIMEOUT (60*HZ) /* HZ == 'jiffies in 1 second' */
+
+#endif /* end of _UAPI_SCSI_SG_H guard */
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 08/23] sg: speed sg_poll and sg_get_num_waiting
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (6 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 07/23] sg: move header to uapi section Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 09/23] sg: sg_allow_if_err_recovery and renames Douglas Gilbert
` (14 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare, Hannes Reinecke
Track the number of submitted and waiting (for read/receive)
requests on each file descriptor with two atomic integers.
This speeds sg_poll() and ioctl(SG_GET_NUM_WAITING) which
are oft used with the asynchronous (non-blocking) interfaces.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 54 +++++++++++++++++++++++------------------------
1 file changed, 27 insertions(+), 27 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 9e9470944fe3..7c9c56bda7ba 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -142,6 +142,8 @@ struct sg_fd { /* holds the state of a file descriptor */
struct mutex f_mutex; /* protect against changes in this fd */
int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
+ atomic_t submitted; /* number inflight or awaiting read */
+ atomic_t waiting; /* number of requests awaiting read */
struct sg_scatter_hold reserve; /* buffer for this file descriptor */
struct list_head rq_list; /* head of request list */
struct fasync_struct *async_qp; /* used by asynchronous notification */
@@ -690,6 +692,8 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
else
at_head = 1;
+ if (!blocking)
+ atomic_inc(&sfp->submitted);
srp->rq->timeout = timeout;
kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
@@ -1096,14 +1100,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
__put_user(-1, ip);
return 0;
case SG_GET_NUM_WAITING:
- read_lock_irqsave(&sfp->rq_list_lock, iflags);
- val = 0;
- list_for_each_entry(srp, &sfp->rq_list, entry) {
- if ((1 == srp->done) && (!srp->sg_io_owned))
- ++val;
- }
- read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return put_user(val, ip);
+ return put_user(atomic_read(&sfp->waiting), ip);
case SG_GET_SG_TABLESIZE:
return put_user(sdp->max_sgat_elems, ip);
case SG_SET_RESERVED_SIZE:
@@ -1255,35 +1252,26 @@ sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
}
#endif
+/*
+ * Implements the poll(2) system call for this driver. Returns various EPOLL*
+ * flags OR-ed together.
+ */
static __poll_t
sg_poll(struct file *filp, poll_table * wait)
{
__poll_t p_res = 0;
struct sg_fd *sfp = filp->private_data;
- struct sg_request *srp;
- int count = 0;
- unsigned long iflags;
- if (!sfp)
- return EPOLLERR;
poll_wait(filp, &sfp->read_wait, wait);
- read_lock_irqsave(&sfp->rq_list_lock, iflags);
- list_for_each_entry(srp, &sfp->rq_list, entry) {
- /* if any read waiting, flag it */
- if (p_res == 0 && srp->done == 1 && !srp->sg_io_owned)
- p_res = EPOLLIN | EPOLLRDNORM;
- ++count;
- }
- read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ if (atomic_read(&sfp->waiting) > 0)
+ p_res = EPOLLIN | EPOLLRDNORM;
- if (sfp->parentdp && SG_IS_DETACHING(sfp->parentdp)) {
+ if (unlikely(SG_IS_DETACHING(sfp->parentdp)))
p_res |= EPOLLHUP;
- } else if (!sfp->cmd_q) {
- if (count == 0)
- p_res |= EPOLLOUT | EPOLLWRNORM;
- } else if (count < SG_MAX_QUEUE) {
+ else if (likely(sfp->cmd_q))
+ p_res |= EPOLLOUT | EPOLLWRNORM;
+ else if (atomic_read(&sfp->submitted) == 0)
p_res |= EPOLLOUT | EPOLLWRNORM;
- }
SG_LOG(3, sfp, "%s: p_res=0x%x\n", __func__, (__force u32)p_res);
return p_res;
}
@@ -1468,6 +1456,8 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
/* Rely on write phase to clean out srp status values, so no "else" */
+ if (!srp->sg_io_owned)
+ atomic_inc(&sfp->waiting);
/*
* Free the request as soon as it is complete so that its resources
* can be reused without waiting for userspace to read() the
@@ -1924,6 +1914,10 @@ sg_finish_rem_req(struct sg_request *srp)
SG_LOG(4, sfp, "%s: srp=0x%p%s\n", __func__, srp,
(srp->res_used) ? " rsv" : "");
+ if (!srp->sg_io_owned) {
+ atomic_dec(&sfp->submitted);
+ atomic_dec(&sfp->waiting);
+ }
if (srp->bio)
ret = blk_rq_unmap_user(srp->bio);
@@ -2220,6 +2214,9 @@ sg_add_sfp(struct sg_device *sdp)
sfp->cmd_q = SG_DEF_COMMAND_Q;
sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
sfp->parentdp = sdp;
+ atomic_set(&sfp->submitted, 0);
+ atomic_set(&sfp->waiting, 0);
+
write_lock_irqsave(&sdp->sfd_lock, iflags);
if (SG_IS_DETACHING(sdp)) {
write_unlock_irqrestore(&sdp->sfd_lock, iflags);
@@ -2593,6 +2590,9 @@ sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
(int) fp->cmd_q, (int) fp->force_packid,
(int) fp->keep_orphan);
+ seq_printf(s, " submitted=%d waiting=%d\n",
+ atomic_read(&fp->submitted),
+ atomic_read(&fp->waiting));
list_for_each_entry(srp, &fp->rq_list, entry) {
hp = &srp->header;
new_interface = (hp->interface_id == '\0') ? 0 : 1;
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 09/23] sg: sg_allow_if_err_recovery and renames
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (7 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 08/23] sg: speed sg_poll and sg_get_num_waiting Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 10/23] sg: remove access_ok functions Douglas Gilbert
` (13 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare, Hannes Reinecke
Add sg_allow_if_err_recover() to do checks common to several entry
points. Replace retval with either res or ret. Rename
sg_finish_rem_req() to sg_finish_scsi_blk_rq(). Rename
sg_new_write() to sg_submit(). Other cleanups triggered by
checkpatch.pl .
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 245 +++++++++++++++++++++++++---------------------
1 file changed, 133 insertions(+), 112 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 7c9c56bda7ba..7e188ac2f182 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -68,7 +68,7 @@ static char *sg_version_date = "20190606";
/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
* of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
- * than 16 bytes are "variable length" whose length is a multiple of 4
+ * than 16 bytes are "variable length" whose length is a multiple of 4, so:
*/
#define SG_MAX_CDB_SIZE 252
@@ -178,16 +178,16 @@ static void sg_rq_end_io(struct request *rq, blk_status_t status);
/* Declarations of other static functions used before they are defined */
static int sg_proc_init(void);
static int sg_start_req(struct sg_request *srp, u8 *cmd);
-static int sg_finish_rem_req(struct sg_request *srp);
+static int sg_finish_scsi_blk_rq(struct sg_request *srp);
static int sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
int buff_size);
-static ssize_t sg_new_write(struct sg_fd *sfp, struct file *file,
- const char __user *buf, size_t count, int blocking,
- int read_only, int sg_io_owned,
- struct sg_request **o_srp);
+static ssize_t sg_submit(struct sg_fd *sfp, struct file *filp,
+ const char __user *buf, size_t count, bool blocking,
+ bool read_only, bool sg_io_owned,
+ struct sg_request **o_srp);
static int sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
u8 *cmnd, int timeout, int blocking);
-static int sg_rd_append(struct sg_request *srp, char __user *outp,
+static int sg_rd_append(struct sg_request *srp, void __user *outp,
int num_xfer);
static void sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
static void sg_build_reserve(struct sg_fd *sfp, int req_size);
@@ -275,37 +275,60 @@ sg_check_file_access(struct file *filp, const char *caller)
static int
sg_wait_open_event(struct sg_device *sdp, bool o_excl)
{
- int retval = 0;
+ int res = 0;
if (o_excl) {
while (atomic_read(&sdp->open_cnt) > 0) {
mutex_unlock(&sdp->open_rel_lock);
- retval = wait_event_interruptible(sdp->open_wait,
- (SG_IS_DETACHING(sdp) ||
- atomic_read(&sdp->open_cnt) == 0));
+ res = wait_event_interruptible
+ (sdp->open_wait,
+ (SG_IS_DETACHING(sdp) ||
+ atomic_read(&sdp->open_cnt) == 0));
mutex_lock(&sdp->open_rel_lock);
- if (retval) /* -ERESTARTSYS */
- return retval;
+ if (res) /* -ERESTARTSYS */
+ return res;
if (SG_IS_DETACHING(sdp))
return -ENODEV;
}
} else {
while (SG_HAVE_EXCLUDE(sdp)) {
mutex_unlock(&sdp->open_rel_lock);
- retval = wait_event_interruptible(sdp->open_wait,
- (SG_IS_DETACHING(sdp) ||
- !SG_HAVE_EXCLUDE(sdp)));
+ res = wait_event_interruptible
+ (sdp->open_wait,
+ (SG_IS_DETACHING(sdp) ||
+ !SG_HAVE_EXCLUDE(sdp)));
mutex_lock(&sdp->open_rel_lock);
- if (retval) /* -ERESTARTSYS */
- return retval;
+ if (res) /* -ERESTARTSYS */
+ return res;
if (SG_IS_DETACHING(sdp))
return -ENODEV;
}
}
- return retval;
+ return res;
+}
+
+/*
+ * scsi_block_when_processing_errors() returns 0 when dev was taken offline by
+ * error recovery, 1 otherwise (i.e. okay). Even if in error recovery, let
+ * user continue if O_NONBLOCK set. Permits SCSI commands to be issued during
+ * error recovery. Tread carefully.
+ * Returns 0 for ok (i.e. allow), -EPROTO if sdp is NULL, otherwise -ENXIO .
+ */
+static inline int
+sg_allow_if_err_recovery(struct sg_device *sdp, bool non_block)
+{
+ if (!sdp)
+ return -EPROTO;
+ if (SG_IS_DETACHING(sdp))
+ return -ENODEV;
+ if (non_block)
+ return 0;
+ if (likely(scsi_block_when_processing_errors(sdp->device)))
+ return 0;
+ return -ENXIO;
}
/*
@@ -318,16 +341,17 @@ sg_wait_open_event(struct sg_device *sdp, bool o_excl)
static int
sg_open(struct inode *inode, struct file *filp)
{
- bool o_excl;
+ bool o_excl, non_block;
int min_dev = iminor(inode);
int op_flags = filp->f_flags;
+ int res;
struct request_queue *q;
struct sg_device *sdp;
struct sg_fd *sfp;
- int retval;
nonseekable_open(inode, filp);
o_excl = !!(op_flags & O_EXCL);
+ non_block = !!(op_flags & O_NONBLOCK);
if (o_excl && ((op_flags & O_ACCMODE) == O_RDONLY))
return -EPERM; /* Can't lock it with read only access */
sdp = sg_get_dev(min_dev);
@@ -336,20 +360,23 @@ sg_open(struct inode *inode, struct file *filp)
/* This driver's module count bumped by fops_get in <linux/fs.h> */
/* Prevent the device driver from vanishing while we sleep */
- retval = scsi_device_get(sdp->device);
- if (retval)
+ res = scsi_device_get(sdp->device);
+ if (res)
goto sg_put;
- retval = scsi_autopm_get_device(sdp->device);
- if (retval)
+ res = scsi_autopm_get_device(sdp->device);
+ if (res)
goto sdp_put;
+ res = sg_allow_if_err_recovery(sdp, non_block);
+ if (res)
+ goto error_out;
/* scsi_block_when_processing_errors() may block so bypass
* check if O_NONBLOCK. Permits SCSI commands to be issued
* during error recovery. Tread carefully. */
if (!((op_flags & O_NONBLOCK) ||
scsi_block_when_processing_errors(sdp->device))) {
- retval = -ENXIO;
+ res = -ENXIO;
/* we are in error recovery for this device */
goto error_out;
}
@@ -358,18 +385,18 @@ sg_open(struct inode *inode, struct file *filp)
if (op_flags & O_NONBLOCK) {
if (o_excl) {
if (atomic_read(&sdp->open_cnt) > 0) {
- retval = -EBUSY;
+ res = -EBUSY;
goto error_mutex_locked;
}
} else {
if (SG_HAVE_EXCLUDE(sdp)) {
- retval = -EBUSY;
+ res = -EBUSY;
goto error_mutex_locked;
}
}
} else {
- retval = sg_wait_open_event(sdp, o_excl);
- if (retval) /* -ERESTARTSYS or -ENODEV */
+ res = sg_wait_open_event(sdp, o_excl);
+ if (res) /* -ERESTARTSYS or -ENODEV */
goto error_mutex_locked;
}
@@ -384,7 +411,7 @@ sg_open(struct inode *inode, struct file *filp)
}
sfp = sg_add_sfp(sdp);
if (IS_ERR(sfp)) {
- retval = PTR_ERR(sfp);
+ res = PTR_ERR(sfp);
goto out_undo;
}
@@ -396,10 +423,10 @@ sg_open(struct inode *inode, struct file *filp)
atomic_read(&sdp->open_cnt),
((op_flags & O_NONBLOCK) ? " O_NONBLOCK" : ""));
- retval = 0;
+ res = 0;
sg_put:
kref_put(&sdp->d_ref, sg_device_destroy);
- return retval;
+ return res;
out_undo:
if (o_excl) { /* undo if error */
@@ -454,31 +481,26 @@ sg_release(struct inode *inode, struct file *filp)
static ssize_t
sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
{
- int mxsize, cmd_size, k;
- int input_size, blocking;
+ bool blocking = !(filp->f_flags & O_NONBLOCK);
u8 opcode;
+ int mxsize, cmd_size, input_size, res;
struct sg_device *sdp;
struct sg_fd *sfp;
struct sg_request *srp;
struct sg_header old_hdr;
sg_io_hdr_t *hp;
u8 cmnd[SG_MAX_CDB_SIZE];
- int retval;
- retval = sg_check_file_access(filp, __func__);
- if (retval)
- return retval;
+ res = sg_check_file_access(filp, __func__);
+ if (res)
+ return res;
sfp = filp->private_data;
sdp = sfp->parentdp;
SG_LOG(3, sfp, "%s: write(3rd arg) count=%d\n", __func__, (int)count);
- if (!sdp)
- return -ENXIO;
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- if (!((filp->f_flags & O_NONBLOCK) ||
- scsi_block_when_processing_errors(sdp->device)))
- return -ENXIO;
+ res = sg_allow_if_err_recovery(sdp, !blocking);
+ if (res)
+ return res;
if (!access_ok(buf, count))
return -EFAULT; /* protects following copy_from_user()s + get_user()s */
@@ -486,10 +508,9 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
return -EIO;
if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
return -EFAULT;
- blocking = !(filp->f_flags & O_NONBLOCK);
if (old_hdr.reply_len < 0)
- return sg_new_write(sfp, filp, buf, count,
- blocking, 0, 0, NULL);
+ return sg_submit(sfp, filp, buf, count, blocking, false, false,
+ NULL);
if (count < (SZ_SG_HEADER + 6))
return -EIO; /* The minimum scsi command length is 6 bytes. */
@@ -557,8 +578,8 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
input_size, (unsigned int) cmnd[0],
current->comm);
}
- k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
- return (k < 0) ? k : count;
+ res = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
+ return (res < 0) ? res : count;
}
static int
@@ -573,9 +594,9 @@ sg_allow_access(struct file *filp, u8 *cmd)
}
static ssize_t
-sg_new_write(struct sg_fd *sfp, struct file *file, const char __user *buf,
- size_t count, int blocking, int read_only, int sg_io_owned,
- struct sg_request **o_srp)
+sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
+ size_t count, bool blocking, bool read_only, bool sg_io_owned,
+ struct sg_request **o_srp)
{
int k;
struct sg_request *srp;
@@ -632,7 +653,7 @@ sg_new_write(struct sg_fd *sfp, struct file *file, const char __user *buf,
sg_remove_request(sfp, srp);
return -EFAULT;
}
- if (read_only && sg_allow_access(file, cmnd)) {
+ if (read_only && sg_allow_access(filp, cmnd)) {
sg_remove_request(sfp, srp);
return -EPERM;
}
@@ -669,7 +690,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
k = sg_start_req(srp, cmnd);
if (k) {
SG_LOG(1, sfp, "%s: start_req err=%d\n", __func__, k);
- sg_finish_rem_req(srp);
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
return k; /* probably out of space --> ENOMEM */
}
@@ -680,7 +701,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
srp->rq = NULL;
}
- sg_finish_rem_req(srp);
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
return -ENODEV;
}
@@ -765,7 +786,7 @@ sg_new_read(struct sg_fd *sfp, char __user *buf, size_t count,
goto err_out;
}
err_out:
- err2 = sg_finish_rem_req(srp);
+ err2 = sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
return err ? : err2 ? : count;
}
@@ -789,23 +810,24 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
struct sg_fd *sfp;
struct sg_request *srp;
int req_pack_id = -1;
+ int ret = 0;
sg_io_hdr_t *hp;
struct sg_header *old_hdr = NULL;
- int retval = 0;
/*
* This could cause a response to be stranded. Close the associated
* file descriptor to free up any resources being held.
*/
- retval = sg_check_file_access(filp, __func__);
- if (retval)
- return retval;
+ ret = sg_check_file_access(filp, __func__);
+ if (ret)
+ return ret;
sfp = filp->private_data;
sdp = sfp->parentdp;
SG_LOG(3, sfp, "%s: read() count=%d\n", __func__, (int)count);
- if (!sdp)
- return -ENXIO;
+ ret = sg_allow_if_err_recovery(sdp, false);
+ if (ret)
+ return ret;
if (!access_ok(buf, count))
return -EFAULT;
@@ -814,7 +836,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
if (!old_hdr)
return -ENOMEM;
if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
- retval = -EFAULT;
+ ret = -EFAULT;
goto free_old_hdr;
}
if (old_hdr->reply_len < 0) {
@@ -823,15 +845,15 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
if (!new_hdr) {
- retval = -ENOMEM;
+ ret = -ENOMEM;
goto free_old_hdr;
}
- retval = __copy_from_user
+ ret = __copy_from_user
(new_hdr, buf, SZ_SG_IO_HDR);
req_pack_id = new_hdr->pack_id;
kfree(new_hdr);
- if (retval) {
- retval = -EFAULT;
+ if (ret) {
+ ret = -EFAULT;
goto free_old_hdr;
}
}
@@ -841,27 +863,28 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
srp = sg_get_rq_mark(sfp, req_pack_id);
if (!srp) { /* now wait on packet to arrive */
if (SG_IS_DETACHING(sdp)) {
- retval = -ENODEV;
+ ret = -ENODEV;
goto free_old_hdr;
}
if (filp->f_flags & O_NONBLOCK) {
- retval = -EAGAIN;
+ ret = -EAGAIN;
goto free_old_hdr;
}
- retval = wait_event_interruptible(sfp->read_wait,
- (SG_IS_DETACHING(sdp) ||
- (srp = sg_get_rq_mark(sfp, req_pack_id))));
+ ret = wait_event_interruptible
+ (sfp->read_wait,
+ (SG_IS_DETACHING(sdp) ||
+ (srp = sg_get_rq_mark(sfp, req_pack_id))));
if (SG_IS_DETACHING(sdp)) {
- retval = -ENODEV;
+ ret = -ENODEV;
goto free_old_hdr;
}
- if (retval) {
+ if (ret) {
/* -ERESTARTSYS as signal hit process */
goto free_old_hdr;
}
}
if (srp->header.interface_id != '\0') {
- retval = sg_new_read(sfp, buf, count, srp);
+ ret = sg_new_read(sfp, buf, count, srp);
goto free_old_hdr;
}
@@ -869,7 +892,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
if (old_hdr == NULL) {
old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
if (!old_hdr) {
- retval = -ENOMEM;
+ ret = -ENOMEM;
goto free_old_hdr;
}
}
@@ -920,7 +943,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
/* Now copy the result back to the user buffer. */
if (count >= SZ_SG_HEADER) {
if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
- retval = -EFAULT;
+ ret = -EFAULT;
goto free_old_hdr;
}
buf += SZ_SG_HEADER;
@@ -928,18 +951,18 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
count = old_hdr->reply_len;
if (count > SZ_SG_HEADER) {
if (sg_rd_append(srp, buf, count - SZ_SG_HEADER)) {
- retval = -EFAULT;
+ ret = -EFAULT;
goto free_old_hdr;
}
}
} else
count = (old_hdr->result == 0) ? 0 : -EIO;
- sg_finish_rem_req(srp);
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
- retval = count;
+ ret = count;
free_old_hdr:
kfree(old_hdr);
- return retval;
+ return ret;
}
static int
@@ -1006,14 +1029,13 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
switch (cmd_in) {
case SG_IO:
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- if (!scsi_block_when_processing_errors(sdp->device))
- return -ENXIO;
+ result = sg_allow_if_err_recovery(sdp, false);
+ if (result)
+ return result;
if (!access_ok(p, SZ_SG_IO_HDR))
return -EFAULT;
- result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
- 1, read_only, 1, &srp);
+ result = sg_submit(sfp, filp, p, SZ_SG_IO_HDR, true, read_only,
+ true, &srp);
if (result < 0)
return result;
result = wait_event_interruptible(sfp->read_wait,
@@ -1219,8 +1241,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
break;
}
- result = scsi_ioctl_block_when_processing_errors(sdp->device,
- cmd_in, filp->f_flags & O_NDELAY);
+ result = sg_allow_if_err_recovery(sdp, filp->f_flags & O_NDELAY);
if (result)
return result;
return scsi_ioctl(sdp->device, cmd_in, p);
@@ -1383,7 +1404,7 @@ sg_rq_end_io_usercontext(struct work_struct *work)
struct sg_request *srp = container_of(work, struct sg_request, ew.work);
struct sg_fd *sfp = srp->parentfp;
- sg_finish_rem_req(srp);
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
kref_put(&sfp->f_ref, sg_remove_sfp);
}
@@ -1905,7 +1926,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
}
static int
-sg_finish_rem_req(struct sg_request *srp)
+sg_finish_scsi_blk_rq(struct sg_request *srp)
{
int ret = 0;
@@ -2050,7 +2071,7 @@ sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
* appended to given struct sg_header object.
*/
static int
-sg_rd_append(struct sg_request *srp, char __user *outp, int num_xfer)
+sg_rd_append(struct sg_request *srp, void __user *outp, int num_xfer)
{
struct sg_scatter_hold *schp = &srp->data;
int k, num;
@@ -2252,7 +2273,7 @@ sg_remove_sfp_usercontext(struct work_struct *work)
write_lock_irqsave(&sfp->rq_list_lock, iflags);
while (!list_empty(&sfp->rq_list)) {
srp = list_first_entry(&sfp->rq_list, struct sg_request, entry);
- sg_finish_rem_req(srp);
+ sg_finish_scsi_blk_rq(srp);
list_del(&srp->entry);
srp->parentfp = NULL;
}
@@ -2330,7 +2351,7 @@ sg_get_dev(int dev)
#if IS_ENABLED(CONFIG_SCSI_PROC_FS) /* long, almost to end of file */
static int sg_proc_seq_show_int(struct seq_file *s, void *v);
-static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
+static int sg_proc_single_open_adio(struct inode *inode, struct file *filp);
static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
size_t count, loff_t *off);
static const struct file_operations adio_fops = {
@@ -2342,7 +2363,7 @@ static const struct file_operations adio_fops = {
.release = single_release,
};
-static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
+static int sg_proc_single_open_dressz(struct inode *inode, struct file *filp);
static ssize_t sg_proc_write_dressz(struct file *filp,
const char __user *buffer, size_t count, loff_t *off);
static const struct file_operations dressz_fops = {
@@ -2392,13 +2413,13 @@ sg_proc_init(void)
if (!p)
return 1;
- proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_fops);
- proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
- proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_fops);
- proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
- proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
- proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
- proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
+ proc_create("allow_dio", 0644, p, &adio_fops);
+ proc_create_seq("debug", 0444, p, &debug_seq_ops);
+ proc_create("def_reserved_size", 0644, p, &dressz_fops);
+ proc_create_single("device_hdr", 0444, p, sg_proc_seq_show_devhdr);
+ proc_create_seq("devices", 0444, p, &dev_seq_ops);
+ proc_create_seq("device_strs", 0444, p, &devstrs_seq_ops);
+ proc_create_single("version", 0444, p, sg_proc_seq_show_version);
return 0;
}
@@ -2422,9 +2443,9 @@ sg_proc_seq_show_int(struct seq_file *s, void *v)
}
static int
-sg_proc_single_open_adio(struct inode *inode, struct file *file)
+sg_proc_single_open_adio(struct inode *inode, struct file *filp)
{
- return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
+ return single_open(filp, sg_proc_seq_show_int, &sg_allow_dio);
}
static ssize_t
@@ -2444,9 +2465,9 @@ sg_proc_write_adio(struct file *filp, const char __user *buffer,
}
static int
-sg_proc_single_open_dressz(struct inode *inode, struct file *file)
+sg_proc_single_open_dressz(struct inode *inode, struct file *filp)
{
- return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
+ return single_open(filp, sg_proc_seq_show_int, &sg_big_buff);
}
static ssize_t
@@ -2508,7 +2529,7 @@ dev_seq_start(struct seq_file *s, loff_t *pos)
static void *
dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
- struct sg_proc_deviter * it = s->private;
+ struct sg_proc_deviter *it = s->private;
*pos = ++it->index;
return (it->index < it->max) ? it : NULL;
@@ -2523,7 +2544,7 @@ dev_seq_stop(struct seq_file *s, void *v)
static int
sg_proc_seq_show_dev(struct seq_file *s, void *v)
{
- struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
+ struct sg_proc_deviter *it = (struct sg_proc_deviter *)v;
struct sg_device *sdp;
struct scsi_device *scsidp;
unsigned long iflags;
@@ -2549,7 +2570,7 @@ sg_proc_seq_show_dev(struct seq_file *s, void *v)
static int
sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
{
- struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
+ struct sg_proc_deviter *it = (struct sg_proc_deviter *)v;
struct sg_device *sdp;
struct scsi_device *scsidp;
unsigned long iflags;
@@ -2637,7 +2658,7 @@ sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
static int
sg_proc_seq_show_debug(struct seq_file *s, void *v)
{
- struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
+ struct sg_proc_deviter *it = (struct sg_proc_deviter *)v;
struct sg_device *sdp;
unsigned long iflags;
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 10/23] sg: remove access_ok functions
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (8 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 09/23] sg: sg_allow_if_err_recovery and renames Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 11/23] sg: improve naming Douglas Gilbert
` (12 subsequent siblings)
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare, Hannes Reinecke
Since access_ok() has lost it direction (3rd) parameter there
seems to be no benefit in calling access_ok() before
__copy_{to|from}_user(). Simplify code by using the variant of
these functions that do not start with "__".
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 85 ++++++++++++++++++-----------------------------
1 file changed, 32 insertions(+), 53 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 7e188ac2f182..d0d0f401ad64 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -502,11 +502,9 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
if (res)
return res;
- if (!access_ok(buf, count))
- return -EFAULT; /* protects following copy_from_user()s + get_user()s */
if (count < SZ_SG_HEADER)
return -EIO;
- if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
+ if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
return -EFAULT;
if (old_hdr.reply_len < 0)
return sg_submit(sfp, filp, buf, count, blocking, false, false,
@@ -561,7 +559,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
hp->flags = input_size; /* structure abuse ... */
hp->pack_id = old_hdr.pack_id;
hp->usr_ptr = NULL;
- if (__copy_from_user(cmnd, buf, cmd_size))
+ if (copy_from_user(cmnd, buf, cmd_size))
return -EFAULT;
/*
* SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
@@ -607,8 +605,6 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
if (count < SZ_SG_IO_HDR)
return -EINVAL;
- if (!access_ok(buf, count))
- return -EFAULT; /* protects following copy_from_user()s + get_user()s */
sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
if (!(srp = sg_add_request(sfp))) {
@@ -617,7 +613,7 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
}
srp->sg_io_owned = sg_io_owned;
hp = &srp->header;
- if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
+ if (copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
sg_remove_request(sfp, srp);
return -EFAULT;
}
@@ -645,11 +641,7 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
sg_remove_request(sfp, srp);
return -EMSGSIZE;
}
- if (!access_ok(hp->cmdp, hp->cmd_len)) {
- sg_remove_request(sfp, srp);
- return -EFAULT; /* protects following copy_from_user()s + get_user()s */
- }
- if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
+ if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
sg_remove_request(sfp, srp);
return -EFAULT;
}
@@ -829,13 +821,11 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
if (ret)
return ret;
- if (!access_ok(buf, count))
- return -EFAULT;
if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
if (!old_hdr)
return -ENOMEM;
- if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
+ if (copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
ret = -EFAULT;
goto free_old_hdr;
}
@@ -848,8 +838,8 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
ret = -ENOMEM;
goto free_old_hdr;
}
- ret = __copy_from_user
- (new_hdr, buf, SZ_SG_IO_HDR);
+ ret = copy_from_user(new_hdr, buf,
+ SZ_SG_IO_HDR);
req_pack_id = new_hdr->pack_id;
kfree(new_hdr);
if (ret) {
@@ -942,7 +932,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
/* Now copy the result back to the user buffer. */
if (count >= SZ_SG_HEADER) {
- if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
+ if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
ret = -EFAULT;
goto free_old_hdr;
}
@@ -1032,8 +1022,6 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
result = sg_allow_if_err_recovery(sdp, false);
if (result)
return result;
- if (!access_ok(p, SZ_SG_IO_HDR))
- return -EFAULT;
result = sg_submit(sfp, filp, p, SZ_SG_IO_HDR, true, read_only,
true, &srp);
if (result < 0)
@@ -1078,28 +1066,23 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
case SG_GET_LOW_DMA:
return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
case SG_GET_SCSI_ID:
- if (!access_ok(p, sizeof (sg_scsi_id_t)))
- return -EFAULT;
- else {
- sg_scsi_id_t __user *sg_idp = p;
-
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- __put_user((int) sdp->device->host->host_no,
- &sg_idp->host_no);
- __put_user((int) sdp->device->channel,
- &sg_idp->channel);
- __put_user((int) sdp->device->id, &sg_idp->scsi_id);
- __put_user((int) sdp->device->lun, &sg_idp->lun);
- __put_user((int) sdp->device->type, &sg_idp->scsi_type);
- __put_user((short) sdp->device->host->cmd_per_lun,
- &sg_idp->h_cmd_per_lun);
- __put_user((short) sdp->device->queue_depth,
- &sg_idp->d_queue_depth);
- __put_user(0, &sg_idp->unused[0]);
- __put_user(0, &sg_idp->unused[1]);
+ if (!SG_IS_DETACHING(sdp)) {
+ struct sg_scsi_id ss_id;
+
+ ss_id.host_no = sdp->device->host->host_no;
+ ss_id.channel = sdp->device->channel;
+ ss_id.scsi_id = sdp->device->id;
+ ss_id.lun = sdp->device->lun;
+ ss_id.scsi_type = sdp->device->type;
+ ss_id.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
+ ss_id.d_queue_depth = sdp->device->queue_depth;
+ ss_id.unused[0] = 0;
+ ss_id.unused[1] = 0;
+ if (copy_to_user(p, &ss_id, sizeof(struct sg_scsi_id)))
+ return -EFAULT;
return 0;
}
+ return -ENODEV;
case SG_SET_FORCE_PACK_ID:
result = get_user(val, ip);
if (result)
@@ -1107,19 +1090,17 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
sfp->force_packid = val ? 1 : 0;
return 0;
case SG_GET_PACK_ID:
- if (!access_ok(ip, sizeof (int)))
- return -EFAULT;
read_lock_irqsave(&sfp->rq_list_lock, iflags);
list_for_each_entry(srp, &sfp->rq_list, entry) {
if ((1 == srp->done) && (!srp->sg_io_owned)) {
read_unlock_irqrestore(&sfp->rq_list_lock,
iflags);
- __put_user(srp->header.pack_id, ip);
+ put_user(srp->header.pack_id, ip);
return 0;
}
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- __put_user(-1, ip);
+ put_user(-1, ip);
return 0;
case SG_GET_NUM_WAITING:
return put_user(atomic_read(&sfp->waiting), ip);
@@ -1181,9 +1162,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
val = (sdp->device ? 1 : 0);
return put_user(val, ip);
case SG_GET_REQUEST_TABLE:
- if (!access_ok(p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
- return -EFAULT;
- else {
+ {
sg_req_info_t *rinfo;
rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
@@ -1193,8 +1172,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
read_lock_irqsave(&sfp->rq_list_lock, iflags);
sg_fill_request_table(sfp, rinfo);
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- result = __copy_to_user(p, rinfo,
- SZ_SG_REQ_INFO * SG_MAX_QUEUE);
+ result = copy_to_user(p, rinfo,
+ SZ_SG_REQ_INFO * SG_MAX_QUEUE);
result = result ? -EFAULT : 0;
kfree(rinfo);
return result;
@@ -2083,13 +2062,13 @@ sg_rd_append(struct sg_request *srp, void __user *outp, int num_xfer)
num = 1 << (PAGE_SHIFT + schp->page_order);
for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
if (num > num_xfer) {
- if (__copy_to_user(outp, page_address(schp->pages[k]),
- num_xfer))
+ if (copy_to_user(outp, page_address(schp->pages[k]),
+ num_xfer))
return -EFAULT;
break;
} else {
- if (__copy_to_user(outp, page_address(schp->pages[k]),
- num))
+ if (copy_to_user(outp, page_address(schp->pages[k]),
+ num))
return -EFAULT;
num_xfer -= num;
if (num_xfer <= 0)
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* [PATCH v5 11/23] sg: improve naming
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (9 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 10/23] sg: remove access_ok functions Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:06 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 12/23] sg: change rwlock to spinlock Douglas Gilbert
` (11 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Remove use of typedef sg_io_hdr_t and replace with struct
sg_io_hdr. Change some names on driver wide structure fields
and comment them.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 234 +++++++++++++++++++++++++---------------------
1 file changed, 125 insertions(+), 109 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index d0d0f401ad64..d28278a30ced 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -92,7 +92,7 @@ static int sg_allow_dio = SG_ALLOW_DIO_DEF;
static int scatter_elem_sz = SG_SCATTER_SZ;
static int scatter_elem_sz_prev = SG_SCATTER_SZ;
-#define SG_SECTOR_SZ 512
+#define SG_DEF_SECTOR_SZ 512
static int sg_add_device(struct device *, struct class_interface *);
static void sg_remove_device(struct device *, struct class_interface *);
@@ -105,12 +105,13 @@ static struct class_interface sg_interface = {
.remove_dev = sg_remove_device,
};
-struct sg_scatter_hold { /* holding area for scsi scatter gather info */
- u16 k_use_sg; /* Count of kernel scatter-gather pieces */
+struct sg_scatter_hold { /* holding area for scsi scatter gather info */
+ struct page **pages; /* num_sgat element array of struct page* */
+ int buflen; /* capacity in bytes (dlen<=buflen) */
+ int dlen; /* current valid data length of this req */
+ u16 page_order; /* byte_len = (page_size*(2**page_order)) */
+ u16 num_sgat; /* actual number of scatter-gather segments */
unsigned int sglist_len; /* size of malloc'd scatter-gather list ++ */
- unsigned int bufflen; /* Size of (aggregate) data buffer */
- struct page **pages;
- int page_order;
char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
u8 cmd_opcode; /* first byte of command */
};
@@ -122,20 +123,20 @@ struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
struct list_head entry; /* list entry */
struct sg_fd *parentfp; /* NULL -> not in use */
struct sg_scatter_hold data; /* hold buffer, perhaps scatter list */
- sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
+ struct sg_io_hdr header; /* scsi command+info, see <scsi/sg.h> */
u8 sense_b[SCSI_SENSE_BUFFERSIZE];
char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
char orphan; /* 1 -> drop on sight, 0 -> normal */
char sg_io_owned; /* 1 -> packet belongs to SG_IO */
/* done protected by rq_list_lock */
char done; /* 0->before bh, 1->before read, 2->read */
- struct request *rq;
- struct bio *bio;
- struct execute_work ew;
+ struct request *rq; /* released in sg_rq_end_io(), bio kept */
+ struct bio *bio; /* kept until this req -->SG_RS_INACTIVE */
+ struct execute_work ew_orph; /* harvest orphan request */
};
struct sg_fd { /* holds the state of a file descriptor */
- struct list_head sfd_siblings; /* protected by device's sfd_lock */
+ struct list_head sfd_entry; /* member sg_device::sfds list */
struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */
rwlock_t rq_list_lock; /* protect access to list in req_arr */
@@ -155,7 +156,7 @@ struct sg_fd { /* holds the state of a file descriptor */
char mmap_called; /* 0 -> mmap() never called on this fd */
char res_in_use; /* 1 -> 'reserve' array in use */
struct kref f_ref;
- struct execute_work ew;
+ struct execute_work ew_fd; /* harvest all fd resources and lists */
};
struct sg_device { /* holds the state of each scsi generic device */
@@ -164,7 +165,7 @@ struct sg_device { /* holds the state of each scsi generic device */
struct mutex open_rel_lock; /* held when in open() or release() */
struct list_head sfds;
rwlock_t sfd_lock; /* protect access to sfd list */
- int max_sgat_elems; /* adapter's max sgat number of elements */
+ int max_sgat_sz; /* max number of bytes in sgat list */
u32 index; /* device index number */
atomic_t open_cnt; /* count of opens (perhaps < num(sfds) ) */
unsigned long fdev_bm[1]; /* see SG_FDEV_* defines above */
@@ -407,7 +408,7 @@ sg_open(struct inode *inode, struct file *filp)
if (atomic_read(&sdp->open_cnt) < 1) { /* no existing opens */
clear_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm);
q = sdp->device->request_queue;
- sdp->max_sgat_elems = queue_max_segments(q);
+ sdp->max_sgat_sz = queue_max_segments(q);
}
sfp = sg_add_sfp(sdp);
if (IS_ERR(sfp)) {
@@ -479,16 +480,18 @@ sg_release(struct inode *inode, struct file *filp)
* of the synchronous ioctl(SG_IO) system call.
*/
static ssize_t
-sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
+sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
{
bool blocking = !(filp->f_flags & O_NONBLOCK);
- u8 opcode;
int mxsize, cmd_size, input_size, res;
+ u8 opcode;
struct sg_device *sdp;
struct sg_fd *sfp;
struct sg_request *srp;
- struct sg_header old_hdr;
- sg_io_hdr_t *hp;
+ struct sg_header ov2hdr;
+ struct sg_io_hdr v3hdr;
+ struct sg_header *ohp = &ov2hdr;
+ struct sg_io_hdr *h3p = &v3hdr;
u8 cmnd[SG_MAX_CDB_SIZE];
res = sg_check_file_access(filp, __func__);
@@ -498,17 +501,28 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
sfp = filp->private_data;
sdp = sfp->parentdp;
SG_LOG(3, sfp, "%s: write(3rd arg) count=%d\n", __func__, (int)count);
- res = sg_allow_if_err_recovery(sdp, !blocking);
+ res = sg_allow_if_err_recovery(sdp, !!(filp->f_flags & O_NONBLOCK));
if (res)
return res;
if (count < SZ_SG_HEADER)
return -EIO;
- if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
+ if (copy_from_user(ohp, p, SZ_SG_HEADER))
return -EFAULT;
- if (old_hdr.reply_len < 0)
- return sg_submit(sfp, filp, buf, count, blocking, false, false,
+ if (ohp->reply_len < 0) { /* assume this is v3 */
+ struct sg_io_hdr *reinter_2p = (struct sg_io_hdr *)ohp;
+
+ if (count < SZ_SG_IO_HDR)
+ return -EIO;
+ if (reinter_2p->interface_id != 'S') {
+ pr_info_once("sg: %s: v3 interface only here\n",
+ __func__);
+ return -EPERM;
+ }
+ return sg_submit(sfp, filp, p, count,
+ !(filp->f_flags & O_NONBLOCK), false, false,
NULL);
+ }
if (count < (SZ_SG_HEADER + 6))
return -EIO; /* The minimum scsi command length is 6 bytes. */
@@ -516,63 +530,64 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
SG_LOG(1, sfp, "%s: queue full\n", __func__);
return -EDOM;
}
- buf += SZ_SG_HEADER;
- __get_user(opcode, buf);
+ p += SZ_SG_HEADER;
+ __get_user(opcode, p);
mutex_lock(&sfp->f_mutex);
if (sfp->next_cmd_len > 0) {
cmd_size = sfp->next_cmd_len;
sfp->next_cmd_len = 0; /* reset so only this write() effected */
} else {
- cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
- if ((opcode >= 0xc0) && old_hdr.twelve_byte)
+ cmd_size = COMMAND_SIZE(opcode); /* old: SCSI command group */
+ if (opcode >= 0xc0 && ohp->twelve_byte)
cmd_size = 12;
}
mutex_unlock(&sfp->f_mutex);
SG_LOG(4, sfp, "%s: scsi opcode=0x%02x, cmd_size=%d\n", __func__,
(unsigned int)opcode, cmd_size);
input_size = count - cmd_size;
- mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
+ mxsize = max_t(int, input_size, ohp->reply_len);
mxsize -= SZ_SG_HEADER;
input_size -= SZ_SG_HEADER;
if (input_size < 0) {
sg_remove_request(sfp, srp);
return -EIO; /* User did not pass enough bytes for this command. */
}
- hp = &srp->header;
- hp->interface_id = '\0'; /* indicator of old interface tunnelled */
- hp->cmd_len = (u8) cmd_size;
- hp->iovec_count = 0;
- hp->mx_sb_len = 0;
+ h3p = &srp->header;
+ h3p->interface_id = '\0'; /* indicator of old interface tunnelled */
+ h3p->cmd_len = (u8)cmd_size;
+ h3p->iovec_count = 0;
+ h3p->mx_sb_len = 0;
if (input_size > 0)
- hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
+ h3p->dxfer_direction = (ohp->reply_len > SZ_SG_HEADER) ?
SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
else
- hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
- hp->dxfer_len = mxsize;
- if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
- (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
- hp->dxferp = (char __user *)buf + cmd_size;
+ h3p->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV :
+ SG_DXFER_NONE;
+ h3p->dxfer_len = mxsize;
+ if (h3p->dxfer_direction == SG_DXFER_TO_DEV ||
+ h3p->dxfer_direction == SG_DXFER_TO_FROM_DEV)
+ h3p->dxferp = (char __user *)p + cmd_size;
else
- hp->dxferp = NULL;
- hp->sbp = NULL;
- hp->timeout = old_hdr.reply_len; /* structure abuse ... */
- hp->flags = input_size; /* structure abuse ... */
- hp->pack_id = old_hdr.pack_id;
- hp->usr_ptr = NULL;
- if (copy_from_user(cmnd, buf, cmd_size))
+ h3p->dxferp = NULL;
+ h3p->sbp = NULL;
+ h3p->timeout = ohp->reply_len; /* structure abuse ... */
+ h3p->flags = input_size; /* structure abuse ... */
+ h3p->pack_id = ohp->pack_id;
+ h3p->usr_ptr = NULL;
+ if (copy_from_user(cmnd, p, cmd_size))
return -EFAULT;
/*
* SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
* but is is possible that the app intended SG_DXFER_TO_DEV, because there
* is a non-zero input_size, so emit a warning.
*/
- if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
+ if (h3p->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
printk_ratelimited(KERN_WARNING
"sg_write: data in/out %d/%d bytes "
"for SCSI command 0x%x-- guessing "
"data in;\n program %s not setting "
"count and/or reply_len properly\n",
- old_hdr.reply_len - (int)SZ_SG_HEADER,
+ ohp->reply_len - (int)SZ_SG_HEADER,
input_size, (unsigned int) cmnd[0],
current->comm);
}
@@ -598,7 +613,7 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
{
int k;
struct sg_request *srp;
- sg_io_hdr_t *hp;
+ struct sg_io_hdr *hp;
u8 cmnd[SG_MAX_CDB_SIZE];
int timeout;
unsigned long ul_timeout;
@@ -622,7 +637,7 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
return -ENOSYS;
}
if (hp->flags & SG_FLAG_MMAP_IO) {
- if (hp->dxfer_len > sfp->reserve.bufflen) {
+ if (hp->dxfer_len > sfp->reserve.buflen) {
sg_remove_request(sfp, srp);
return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
}
@@ -663,7 +678,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
{
int k, at_head;
struct sg_device *sdp = sfp->parentdp;
- sg_io_hdr_t *hp = &srp->header;
+ struct sg_io_hdr *hp = &srp->header;
srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
hp->status = 0;
@@ -745,7 +760,7 @@ static ssize_t
sg_new_read(struct sg_fd *sfp, char __user *buf, size_t count,
struct sg_request *srp)
{
- sg_io_hdr_t *hp = &srp->header;
+ struct sg_io_hdr *hp = &srp->header;
int err = 0, err2;
int len;
@@ -803,7 +818,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
struct sg_request *srp;
int req_pack_id = -1;
int ret = 0;
- sg_io_hdr_t *hp;
+ struct sg_io_hdr *hp;
struct sg_header *old_hdr = NULL;
/*
@@ -831,7 +846,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
}
if (old_hdr->reply_len < 0) {
if (count >= SZ_SG_IO_HDR) {
- sg_io_hdr_t *new_hdr;
+ struct sg_io_hdr *new_hdr;
new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
if (!new_hdr) {
@@ -1105,7 +1120,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
case SG_GET_NUM_WAITING:
return put_user(atomic_read(&sfp->waiting), ip);
case SG_GET_SG_TABLESIZE:
- return put_user(sdp->max_sgat_elems, ip);
+ return put_user(sdp->max_sgat_sz, ip);
case SG_SET_RESERVED_SIZE:
result = get_user(val, ip);
if (result)
@@ -1115,7 +1130,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
val = min_t(int, val,
max_sectors_bytes(sdp->device->request_queue));
mutex_lock(&sfp->f_mutex);
- if (val != sfp->reserve.bufflen) {
+ if (val != sfp->reserve.buflen) {
if (sfp->mmap_called ||
sfp->res_in_use) {
mutex_unlock(&sfp->f_mutex);
@@ -1128,7 +1143,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
mutex_unlock(&sfp->f_mutex);
return 0;
case SG_GET_RESERVED_SIZE:
- val = min_t(int, sfp->reserve.bufflen,
+ val = min_t(int, sfp->reserve.buflen,
max_sectors_bytes(sdp->device->request_queue));
return put_user(val, ip);
case SG_SET_COMMAND_Q:
@@ -1306,12 +1321,12 @@ sg_vma_fault(struct vm_fault *vmf)
}
rsv_schp = &sfp->reserve;
offset = vmf->pgoff << PAGE_SHIFT;
- if (offset >= rsv_schp->bufflen)
+ if (offset >= rsv_schp->buflen)
return VM_FAULT_SIGBUS;
sa = vma->vm_start;
SG_LOG(3, sfp, "%s: vm_start=0x%lx, off=%lu\n", __func__, sa, offset);
length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
- for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
+ for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) {
len = vma->vm_end - sa;
len = (len < length) ? len : length;
if (offset < len) {
@@ -1355,14 +1370,14 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
return -EINVAL; /* want no offset */
rsv_schp = &sfp->reserve;
mutex_lock(&sfp->f_mutex);
- if (req_sz > rsv_schp->bufflen) {
+ if (req_sz > rsv_schp->buflen) {
ret = -ENOMEM; /* cannot map more than reserved buffer */
goto out;
}
sa = vma->vm_start;
length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
- for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
+ for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) {
len = vma->vm_end - sa;
len = (len < length) ? len : length;
sa += len;
@@ -1380,7 +1395,8 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
static void
sg_rq_end_io_usercontext(struct work_struct *work)
{
- struct sg_request *srp = container_of(work, struct sg_request, ew.work);
+ struct sg_request *srp = container_of(work, struct sg_request,
+ ew_orph.work);
struct sg_fd *sfp = srp->parentfp;
sg_finish_scsi_blk_rq(srp);
@@ -1486,8 +1502,8 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
kref_put(&sfp->f_ref, sg_remove_sfp);
} else {
- INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
- schedule_work(&srp->ew.work);
+ INIT_WORK(&srp->ew_orph.work, sg_rq_end_io_usercontext);
+ schedule_work(&srp->ew_orph.work);
}
}
@@ -1554,7 +1570,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
init_waitqueue_head(&sdp->open_wait);
clear_bit(SG_FDEV_DETACHING, sdp->fdev_bm);
rwlock_init(&sdp->sfd_lock);
- sdp->max_sgat_elems = queue_max_segments(q);
+ sdp->max_sgat_sz = queue_max_segments(q);
sdp->index = k;
kref_init(&sdp->d_ref);
error = 0;
@@ -1688,7 +1704,7 @@ sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
"%s: 0x%p\n", __func__, sdp));
read_lock_irqsave(&sdp->sfd_lock, iflags);
- list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
+ list_for_each_entry(sfp, &sdp->sfds, sfd_entry) {
wake_up_interruptible_all(&sfp->read_wait);
kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
}
@@ -1782,7 +1798,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
struct request *rq;
struct scsi_request *req;
struct sg_fd *sfp = srp->parentfp;
- sg_io_hdr_t *hp = &srp->header;
+ struct sg_io_hdr *hp = &srp->header;
int dxfer_len = (int) hp->dxfer_len;
int dxfer_dir = hp->dxfer_direction;
unsigned int iov_count = hp->iovec_count;
@@ -1843,13 +1859,13 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
if (md) {
mutex_lock(&sfp->f_mutex);
- if (dxfer_len <= rsv_schp->bufflen &&
+ if (dxfer_len <= rsv_schp->buflen &&
!sfp->res_in_use) {
sfp->res_in_use = 1;
sg_link_reserve(sfp, srp, dxfer_len);
} else if (hp->flags & SG_FLAG_MMAP_IO) {
res = -EBUSY; /* sfp->res_in_use == 1 */
- if (dxfer_len > rsv_schp->bufflen)
+ if (dxfer_len > rsv_schp->buflen)
res = -ENOMEM;
mutex_unlock(&sfp->f_mutex);
return res;
@@ -1864,7 +1880,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
md->pages = req_schp->pages;
md->page_order = req_schp->page_order;
- md->nr_entries = req_schp->k_use_sg;
+ md->nr_entries = req_schp->num_sgat;
md->offset = 0;
md->null_mapped = hp->dxferp ? 0 : 1;
if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
@@ -1938,13 +1954,13 @@ static int
sg_build_sgat(struct sg_scatter_hold *schp, const struct sg_fd *sfp,
int tablesize)
{
- int sg_bufflen = tablesize * sizeof(struct page *);
+ int sg_buflen = tablesize * sizeof(struct page *);
gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
- schp->pages = kzalloc(sg_bufflen, gfp_flags);
+ schp->pages = kzalloc(sg_buflen, gfp_flags);
if (!schp->pages)
return -ENOMEM;
- schp->sglist_len = sg_bufflen;
+ schp->sglist_len = sg_buflen;
return tablesize; /* number of scat_gath elements allocated */
}
@@ -1953,7 +1969,7 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
int buff_size)
{
int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
- int max_sgat_elems = sfp->parentdp->max_sgat_elems;
+ int max_sgat_sz = sfp->parentdp->max_sgat_sz;
int blk_size = buff_size, order;
gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
struct sg_device *sdp = sfp->parentdp;
@@ -1962,13 +1978,13 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
return -EFAULT;
if (0 == blk_size)
++blk_size; /* don't know why */
- /* round request up to next highest SG_SECTOR_SZ byte boundary */
- blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
+ /* round request up to next highest SG_DEF_SECTOR_SZ byte boundary */
+ blk_size = ALIGN(blk_size, SG_DEF_SECTOR_SZ);
SG_LOG(4, sfp, "%s: buff_size=%d, blk_size=%d\n", __func__, buff_size,
blk_size);
/* N.B. ret_sz carried into this block ... */
- mx_sc_elems = sg_build_sgat(schp, sfp, max_sgat_elems);
+ mx_sc_elems = sg_build_sgat(schp, sfp, max_sgat_sz);
if (mx_sc_elems < 0)
return mx_sc_elems; /* most likely -ENOMEM */
@@ -2009,9 +2025,9 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
} /* end of for loop */
schp->page_order = order;
- schp->k_use_sg = k;
- SG_LOG(5, sfp, "%s: k_use_sg=%d, order=%d\n", __func__, k, order);
- schp->bufflen = blk_size;
+ schp->num_sgat = k;
+ SG_LOG(5, sfp, "%s: num_sgat=%d, order=%d\n", __func__, k, order);
+ schp->buflen = blk_size;
if (rem_sz > 0) /* must have failed */
return -ENOMEM;
return 0;
@@ -2028,12 +2044,12 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
static void
sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
{
- SG_LOG(4, sfp, "%s: num_sgat=%d\n", __func__, schp->k_use_sg);
+ SG_LOG(4, sfp, "%s: num_sgat=%d\n", __func__, schp->num_sgat);
if (schp->pages && schp->sglist_len > 0) {
if (!schp->dio_in_use) {
int k;
- for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
+ for (k = 0; k < schp->num_sgat && schp->pages[k]; k++) {
SG_LOG(5, sfp, "%s: pg[%d]=0x%p --\n",
__func__, k, schp->pages[k]);
__free_pages(schp->pages[k], schp->page_order);
@@ -2060,7 +2076,7 @@ sg_rd_append(struct sg_request *srp, void __user *outp, int num_xfer)
return 0;
num = 1 << (PAGE_SHIFT + schp->page_order);
- for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
+ for (k = 0; k < schp->num_sgat && schp->pages[k]; k++) {
if (num > num_xfer) {
if (copy_to_user(outp, page_address(schp->pages[k]),
num_xfer))
@@ -2108,20 +2124,20 @@ sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp, int size)
rem = size;
num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
- for (k = 0; k < rsv_schp->k_use_sg; k++) {
+ for (k = 0; k < rsv_schp->num_sgat; k++) {
if (rem <= num) {
- req_schp->k_use_sg = k + 1;
+ req_schp->num_sgat = k + 1;
req_schp->sglist_len = rsv_schp->sglist_len;
req_schp->pages = rsv_schp->pages;
- req_schp->bufflen = size;
+ req_schp->buflen = size;
req_schp->page_order = rsv_schp->page_order;
break;
} else
rem -= num;
}
- if (k >= rsv_schp->k_use_sg)
+ if (k >= rsv_schp->num_sgat)
SG_LOG(1, sfp, "%s: BAD size\n", __func__);
}
@@ -2130,10 +2146,10 @@ sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp)
{
struct sg_scatter_hold *req_schp = &srp->data;
- SG_LOG(4, srp->parentfp, "%s: req->k_use_sg=%d\n", __func__,
- (int)req_schp->k_use_sg);
- req_schp->k_use_sg = 0;
- req_schp->bufflen = 0;
+ SG_LOG(4, srp->parentfp, "%s: req->num_sgat=%d\n", __func__,
+ (int)req_schp->num_sgat);
+ req_schp->num_sgat = 0;
+ req_schp->buflen = 0;
req_schp->pages = NULL;
req_schp->page_order = 0;
req_schp->sglist_len = 0;
@@ -2223,7 +2239,7 @@ sg_add_sfp(struct sg_device *sdp)
kfree(sfp);
return ERR_PTR(-ENODEV);
}
- list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
+ list_add_tail(&sfp->sfd_entry, &sdp->sfds);
write_unlock_irqrestore(&sdp->sfd_lock, iflags);
SG_LOG(3, sfp, "%s: sfp=0x%p\n", __func__, sfp);
if (unlikely(sg_big_buff != def_reserved_size))
@@ -2232,8 +2248,8 @@ sg_add_sfp(struct sg_device *sdp)
bufflen = min_t(int, sg_big_buff,
max_sectors_bytes(sdp->device->request_queue));
sg_build_reserve(sfp, bufflen);
- SG_LOG(3, sfp, "%s: bufflen=%d, k_use_sg=%d\n", __func__,
- sfp->reserve.bufflen, sfp->reserve.k_use_sg);
+ SG_LOG(3, sfp, "%s: bufflen=%d, num_sgat=%d\n", __func__,
+ sfp->reserve.buflen, sfp->reserve.num_sgat);
kref_get(&sdp->d_ref);
__module_get(THIS_MODULE);
@@ -2243,7 +2259,7 @@ sg_add_sfp(struct sg_device *sdp)
static void
sg_remove_sfp_usercontext(struct work_struct *work)
{
- struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
+ struct sg_fd *sfp = container_of(work, struct sg_fd, ew_fd.work);
struct sg_device *sdp = sfp->parentdp;
struct sg_request *srp;
unsigned long iflags;
@@ -2258,9 +2274,9 @@ sg_remove_sfp_usercontext(struct work_struct *work)
}
write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- if (sfp->reserve.bufflen > 0) {
- SG_LOG(6, sfp, "%s: bufflen=%d, k_use_sg=%d\n", __func__,
- (int)sfp->reserve.bufflen, (int)sfp->reserve.k_use_sg);
+ if (sfp->reserve.buflen > 0) {
+ SG_LOG(6, sfp, "%s: buflen=%d, num_sgat=%d\n", __func__,
+ (int)sfp->reserve.buflen, (int)sfp->reserve.num_sgat);
sg_remove_scat(sfp, &sfp->reserve);
}
@@ -2280,11 +2296,11 @@ sg_remove_sfp(struct kref *kref)
unsigned long iflags;
write_lock_irqsave(&sdp->sfd_lock, iflags);
- list_del(&sfp->sfd_siblings);
+ list_del(&sfp->sfd_entry);
write_unlock_irqrestore(&sdp->sfd_lock, iflags);
- INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
- schedule_work(&sfp->ew.work);
+ INIT_WORK(&sfp->ew_fd.work, sg_remove_sfp_usercontext);
+ schedule_work(&sfp->ew_fd.work);
}
static int
@@ -2573,19 +2589,19 @@ sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
int k, new_interface, blen, usg;
struct sg_request *srp;
struct sg_fd *fp;
- const sg_io_hdr_t *hp;
+ const struct sg_io_hdr *hp;
const char * cp;
unsigned int ms;
k = 0;
- list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
+ list_for_each_entry(fp, &sdp->sfds, sfd_entry) {
k++;
read_lock(&fp->rq_list_lock); /* irqs already disabled */
- seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
+ seq_printf(s, " FD(%d): timeout=%dms buflen=%d "
"(res)sgat=%d low_dma=%d\n", k,
jiffies_to_msecs(fp->timeout),
- fp->reserve.bufflen,
- (int) fp->reserve.k_use_sg,
+ fp->reserve.buflen,
+ (int)fp->reserve.num_sgat,
(int) sdp->device->host->unchecked_isa_dma);
seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
(int) fp->cmd_q, (int) fp->force_packid,
@@ -2609,8 +2625,8 @@ sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
cp = " ";
}
seq_puts(s, cp);
- blen = srp->data.bufflen;
- usg = srp->data.k_use_sg;
+ blen = srp->data.buflen;
+ usg = srp->data.num_sgat;
seq_puts(s, srp->done ?
((1 == srp->done) ? "rcv:" : "fin:")
: "act:");
@@ -2663,8 +2679,8 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
scsidp->lun,
scsidp->host->hostt->emulated);
}
- seq_printf(s, " max_sgat_elems=%d excl=%d open_cnt=%d\n",
- sdp->max_sgat_elems, SG_HAVE_EXCLUDE(sdp),
+ seq_printf(s, " max_sgat_sz=%d excl=%d open_cnt=%d\n",
+ sdp->max_sgat_sz, SG_HAVE_EXCLUDE(sdp),
atomic_read(&sdp->open_cnt));
sg_proc_debug_helper(s, sdp);
}
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 11/23] sg: improve naming
2019-10-08 7:50 ` [PATCH v5 11/23] sg: improve naming Douglas Gilbert
@ 2019-10-18 10:06 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:06 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Remove use of typedef sg_io_hdr_t and replace with struct
> sg_io_hdr. Change some names on driver wide structure fields
> and comment them.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 234 +++++++++++++++++++++++++---------------------
> 1 file changed, 125 insertions(+), 109 deletions(-)
>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 12/23] sg: change rwlock to spinlock
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (10 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 11/23] sg: improve naming Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:09 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 13/23] sg: ioctl handling Douglas Gilbert
` (10 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
A reviewer suggested that the extra overhead associated with a
rw lock compared to a spinlock was not worth it for short,
oft-used critcal sections.
So the rwlock on the request list/array is changed to a spinlock.
The head of that list is in the owning sf file descriptor object.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 52 +++++++++++++++++++++++------------------------
1 file changed, 26 insertions(+), 26 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index d28278a30ced..2796fef42837 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -139,7 +139,7 @@ struct sg_fd { /* holds the state of a file descriptor */
struct list_head sfd_entry; /* member sg_device::sfds list */
struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */
- rwlock_t rq_list_lock; /* protect access to list in req_arr */
+ spinlock_t rq_list_lock; /* protect access to list in req_arr */
struct mutex f_mutex; /* protect against changes in this fd */
int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
@@ -742,17 +742,17 @@ sg_get_rq_mark(struct sg_fd *sfp, int pack_id)
struct sg_request *resp;
unsigned long iflags;
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
list_for_each_entry(resp, &sfp->rq_list, entry) {
/* look for requests that are ready + not SG_IO owned */
if ((resp->done == 1) && (!resp->sg_io_owned) &&
((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
resp->done = 2; /* guard against other readers */
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
return resp;
}
}
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
return NULL;
}
@@ -804,9 +804,9 @@ srp_done(struct sg_fd *sfp, struct sg_request *srp)
unsigned long flags;
int ret;
- read_lock_irqsave(&sfp->rq_list_lock, flags);
+ spin_lock_irqsave(&sfp->rq_list_lock, flags);
ret = srp->done;
- read_unlock_irqrestore(&sfp->rq_list_lock, flags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, flags);
return ret;
}
@@ -1045,15 +1045,15 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
(srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
if (SG_IS_DETACHING(sdp))
return -ENODEV;
- write_lock_irq(&sfp->rq_list_lock);
+ spin_lock_irq(&sfp->rq_list_lock);
if (srp->done) {
srp->done = 2;
- write_unlock_irq(&sfp->rq_list_lock);
+ spin_unlock_irq(&sfp->rq_list_lock);
result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
return (result < 0) ? result : 0;
}
srp->orphan = 1;
- write_unlock_irq(&sfp->rq_list_lock);
+ spin_unlock_irq(&sfp->rq_list_lock);
return result; /* -ERESTARTSYS because signal hit process */
case SG_SET_TIMEOUT:
result = get_user(val, ip);
@@ -1105,16 +1105,16 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
sfp->force_packid = val ? 1 : 0;
return 0;
case SG_GET_PACK_ID:
- read_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
list_for_each_entry(srp, &sfp->rq_list, entry) {
if ((1 == srp->done) && (!srp->sg_io_owned)) {
- read_unlock_irqrestore(&sfp->rq_list_lock,
+ spin_unlock_irqrestore(&sfp->rq_list_lock,
iflags);
put_user(srp->header.pack_id, ip);
return 0;
}
}
- read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
put_user(-1, ip);
return 0;
case SG_GET_NUM_WAITING:
@@ -1184,9 +1184,9 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
GFP_KERNEL);
if (!rinfo)
return -ENOMEM;
- read_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
sg_fill_request_table(sfp, rinfo);
- read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
result = copy_to_user(p, rinfo,
SZ_SG_REQ_INFO * SG_MAX_QUEUE);
result = result ? -EFAULT : 0;
@@ -1484,7 +1484,7 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
scsi_req_free_cmd(scsi_req(rq));
blk_put_request(rq);
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
if (unlikely(srp->orphan)) {
if (sfp->keep_orphan)
srp->sg_io_owned = 0;
@@ -1492,7 +1492,7 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
done = 0;
}
srp->done = done;
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
if (likely(done)) {
/* Now wake up any sg_read() that is waiting for this
@@ -2166,7 +2166,7 @@ sg_add_request(struct sg_fd *sfp)
unsigned long iflags;
struct sg_request *rp = sfp->req_arr;
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
if (!list_empty(&sfp->rq_list)) {
if (!sfp->cmd_q)
goto out_unlock;
@@ -2182,10 +2182,10 @@ sg_add_request(struct sg_fd *sfp)
rp->parentfp = sfp;
rp->header.duration = jiffies_to_msecs(jiffies);
list_add_tail(&rp->entry, &sfp->rq_list);
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
return rp;
out_unlock:
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
return NULL;
}
@@ -2198,13 +2198,13 @@ sg_remove_request(struct sg_fd *sfp, struct sg_request *srp)
if (!sfp || !srp || list_empty(&sfp->rq_list))
return res;
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
if (!list_empty(&srp->entry)) {
list_del(&srp->entry);
srp->parentfp = NULL;
res = 1;
}
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
return res;
}
@@ -2220,7 +2220,7 @@ sg_add_sfp(struct sg_device *sdp)
return ERR_PTR(-ENOMEM);
init_waitqueue_head(&sfp->read_wait);
- rwlock_init(&sfp->rq_list_lock);
+ spin_lock_init(&sfp->rq_list_lock);
INIT_LIST_HEAD(&sfp->rq_list);
kref_init(&sfp->f_ref);
mutex_init(&sfp->f_mutex);
@@ -2265,14 +2265,14 @@ sg_remove_sfp_usercontext(struct work_struct *work)
unsigned long iflags;
/* Cleanup any responses which were never read(). */
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
while (!list_empty(&sfp->rq_list)) {
srp = list_first_entry(&sfp->rq_list, struct sg_request, entry);
sg_finish_scsi_blk_rq(srp);
list_del(&srp->entry);
srp->parentfp = NULL;
}
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
if (sfp->reserve.buflen > 0) {
SG_LOG(6, sfp, "%s: buflen=%d, num_sgat=%d\n", __func__,
@@ -2596,7 +2596,7 @@ sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
k = 0;
list_for_each_entry(fp, &sdp->sfds, sfd_entry) {
k++;
- read_lock(&fp->rq_list_lock); /* irqs already disabled */
+ spin_lock(&fp->rq_list_lock); /* irqs already disabled */
seq_printf(s, " FD(%d): timeout=%dms buflen=%d "
"(res)sgat=%d low_dma=%d\n", k,
jiffies_to_msecs(fp->timeout),
@@ -2646,7 +2646,7 @@ sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
}
if (list_empty(&fp->rq_list))
seq_puts(s, " No requests active\n");
- read_unlock(&fp->rq_list_lock);
+ spin_unlock(&fp->rq_list_lock);
}
}
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 12/23] sg: change rwlock to spinlock
2019-10-08 7:50 ` [PATCH v5 12/23] sg: change rwlock to spinlock Douglas Gilbert
@ 2019-10-18 10:09 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:09 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> A reviewer suggested that the extra overhead associated with a
> rw lock compared to a spinlock was not worth it for short,
> oft-used critcal sections.
>
> So the rwlock on the request list/array is changed to a spinlock.
> The head of that list is in the owning sf file descriptor object.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 52 +++++++++++++++++++++++------------------------
> 1 file changed, 26 insertions(+), 26 deletions(-)
>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 13/23] sg: ioctl handling
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (11 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 12/23] sg: change rwlock to spinlock Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:12 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 14/23] sg: split sg_read Douglas Gilbert
` (9 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Shorten sg_ioctl() by adding some helper functions. sg_ioctl()
is the main entry point for ioctls used on this driver's
devices.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 325 ++++++++++++++++++++++++++++------------------
1 file changed, 200 insertions(+), 125 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 2796fef42837..90753f7759c7 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -72,6 +72,9 @@ static char *sg_version_date = "20190606";
*/
#define SG_MAX_CDB_SIZE 252
+#define uptr64(val) ((void __user *)(uintptr_t)(val))
+#define cuptr64(val) ((const void __user *)(uintptr_t)(val))
+
#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
/* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
@@ -1013,16 +1016,111 @@ sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
}
}
+/*
+ * Handles ioctl(SG_IO) for blocking (sync) usage of v3 or v4 interface.
+ * Returns 0 on success else a negated errno.
+ */
+static int
+sg_ctl_sg_io(struct file *filp, struct sg_device *sdp, struct sg_fd *sfp,
+ void __user *p)
+{
+ bool read_only = O_RDWR != (filp->f_flags & O_ACCMODE);
+ int res;
+ struct sg_request *srp;
+
+ res = sg_allow_if_err_recovery(sdp, false);
+ if (res)
+ return res;
+ res = sg_submit(sfp, filp, p, SZ_SG_IO_HDR, true, read_only,
+ true, &srp);
+ if (res < 0)
+ return res;
+ res = wait_event_interruptible
+ (sfp->read_wait, (srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
+ if (SG_IS_DETACHING(sdp))
+ return -ENODEV;
+ spin_lock_irq(&sfp->rq_list_lock);
+ if (srp->done) {
+ srp->done = 2;
+ spin_unlock_irq(&sfp->rq_list_lock);
+ res = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
+ return (res < 0) ? res : 0;
+ }
+ srp->orphan = 1;
+ spin_unlock_irq(&sfp->rq_list_lock);
+ return res; /* -ERESTARTSYS because signal hit process */
+}
+
+static int
+sg_set_reserved_sz(struct sg_fd *sfp, int want_rsv_sz)
+{
+ if (want_rsv_sz != sfp->reserve.buflen) {
+ if (sfp->mmap_called ||
+ sfp->res_in_use) {
+ return -EBUSY;
+ }
+
+ sg_remove_scat(sfp, &sfp->reserve);
+ sg_build_reserve(sfp, want_rsv_sz);
+ }
+ return 0;
+}
+
+static int
+sg_ctl_req_tbl(struct sg_fd *sfp, void __user *p)
+{
+ int result;
+ unsigned long iflags;
+ sg_req_info_t *rinfo;
+
+ rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
+ GFP_KERNEL);
+ if (!rinfo)
+ return -ENOMEM;
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
+ sg_fill_request_table(sfp, rinfo);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ result = copy_to_user(p, rinfo,
+ SZ_SG_REQ_INFO * SG_MAX_QUEUE);
+ result = result ? -EFAULT : 0;
+ kfree(rinfo);
+ return result;
+}
+
+static int
+sg_ctl_scsi_id(struct scsi_device *sdev, struct sg_fd *sfp, void __user *p)
+{
+ struct sg_scsi_id ss_id;
+
+ SG_LOG(3, sfp, "%s: SG_GET_SCSI_ID\n", __func__);
+ ss_id.host_no = sdev->host->host_no;
+ ss_id.channel = sdev->channel;
+ ss_id.scsi_id = sdev->id;
+ ss_id.lun = sdev->lun;
+ ss_id.scsi_type = sdev->type;
+ ss_id.h_cmd_per_lun = sdev->host->cmd_per_lun;
+ ss_id.d_queue_depth = sdev->queue_depth;
+ ss_id.unused[0] = 0;
+ ss_id.unused[1] = 0;
+ if (copy_to_user(p, &ss_id, sizeof(struct sg_scsi_id)))
+ return -EFAULT;
+ return 0;
+}
+
static long
sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
- void __user *p = (void __user *)arg;
+ bool read_only = O_RDWR != (filp->f_flags & O_ACCMODE);
+ int val;
+ int result = 0;
+ void __user *p = uptr64(arg);
int __user *ip = p;
- int result, val, read_only;
struct sg_device *sdp;
struct sg_fd *sfp;
struct sg_request *srp;
+ struct scsi_device *sdev;
unsigned long iflags;
+ __maybe_unused const char *pmlp = ", pass to mid-level";
sfp = filp->private_data;
sdp = sfp->parentdp;
@@ -1030,139 +1128,118 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
!!(filp->f_flags & O_NONBLOCK));
if (!sdp)
return -ENXIO;
- read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
+ if (unlikely(SG_IS_DETACHING(sdp)))
+ return -ENODEV;
+ sdev = sdp->device;
switch (cmd_in) {
case SG_IO:
- result = sg_allow_if_err_recovery(sdp, false);
- if (result)
- return result;
- result = sg_submit(sfp, filp, p, SZ_SG_IO_HDR, true, read_only,
- true, &srp);
- if (result < 0)
- return result;
- result = wait_event_interruptible(sfp->read_wait,
- (srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- spin_lock_irq(&sfp->rq_list_lock);
- if (srp->done) {
- srp->done = 2;
- spin_unlock_irq(&sfp->rq_list_lock);
- result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
- return (result < 0) ? result : 0;
- }
- srp->orphan = 1;
- spin_unlock_irq(&sfp->rq_list_lock);
- return result; /* -ERESTARTSYS because signal hit process */
- case SG_SET_TIMEOUT:
- result = get_user(val, ip);
- if (result)
- return result;
- if (val < 0)
- return -EIO;
- if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
- val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
- INT_MAX);
- sfp->timeout_user = val;
- sfp->timeout = mult_frac(val, HZ, USER_HZ);
-
- return 0;
- case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
- /* strange ..., for backward compatibility */
- return sfp->timeout_user;
- case SG_SET_FORCE_LOW_DMA:
- /*
- * N.B. This ioctl never worked properly, but failed to
- * return an error value. So returning '0' to keep compability
- * with legacy applications.
- */
- return 0;
- case SG_GET_LOW_DMA:
- return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
+ return sg_ctl_sg_io(filp, sdp, sfp, p);
case SG_GET_SCSI_ID:
- if (!SG_IS_DETACHING(sdp)) {
- struct sg_scsi_id ss_id;
-
- ss_id.host_no = sdp->device->host->host_no;
- ss_id.channel = sdp->device->channel;
- ss_id.scsi_id = sdp->device->id;
- ss_id.lun = sdp->device->lun;
- ss_id.scsi_type = sdp->device->type;
- ss_id.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
- ss_id.d_queue_depth = sdp->device->queue_depth;
- ss_id.unused[0] = 0;
- ss_id.unused[1] = 0;
- if (copy_to_user(p, &ss_id, sizeof(struct sg_scsi_id)))
- return -EFAULT;
- return 0;
- }
- return -ENODEV;
+ return sg_ctl_scsi_id(sdev, sfp, p);
case SG_SET_FORCE_PACK_ID:
+ SG_LOG(3, sfp, "%s: SG_SET_FORCE_PACK_ID\n", __func__);
result = get_user(val, ip);
if (result)
return result;
sfp->force_packid = val ? 1 : 0;
return 0;
case SG_GET_PACK_ID:
+ val = -1;
spin_lock_irqsave(&sfp->rq_list_lock, iflags);
list_for_each_entry(srp, &sfp->rq_list, entry) {
if ((1 == srp->done) && (!srp->sg_io_owned)) {
- spin_unlock_irqrestore(&sfp->rq_list_lock,
- iflags);
- put_user(srp->header.pack_id, ip);
- return 0;
+ val = srp->header.pack_id;
+ break;
}
}
spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- put_user(-1, ip);
+ SG_LOG(3, sfp, "%s: SG_GET_PACK_ID=%d\n", __func__, val);
+ put_user(val, ip);
return 0;
case SG_GET_NUM_WAITING:
return put_user(atomic_read(&sfp->waiting), ip);
case SG_GET_SG_TABLESIZE:
+ SG_LOG(3, sfp, "%s: SG_GET_SG_TABLESIZE=%d\n", __func__,
+ sdp->max_sgat_sz);
return put_user(sdp->max_sgat_sz, ip);
case SG_SET_RESERVED_SIZE:
- result = get_user(val, ip);
- if (result)
- return result;
- if (val < 0)
- return -EINVAL;
- val = min_t(int, val,
- max_sectors_bytes(sdp->device->request_queue));
mutex_lock(&sfp->f_mutex);
- if (val != sfp->reserve.buflen) {
- if (sfp->mmap_called ||
- sfp->res_in_use) {
- mutex_unlock(&sfp->f_mutex);
- return -EBUSY;
+ result = get_user(val, ip);
+ if (!result) {
+ if (val >= 0 && val <= (1024 * 1024 * 1024)) {
+ result = sg_set_reserved_sz(sfp, val);
+ } else {
+ SG_LOG(3, sfp, "%s: invalid size\n", __func__);
+ result = -EINVAL;
}
-
- sg_remove_scat(sfp, &sfp->reserve);
- sg_build_reserve(sfp, val);
}
mutex_unlock(&sfp->f_mutex);
- return 0;
+ return result;
case SG_GET_RESERVED_SIZE:
val = min_t(int, sfp->reserve.buflen,
- max_sectors_bytes(sdp->device->request_queue));
+ max_sectors_bytes(sdev->request_queue));
+ SG_LOG(3, sfp, "%s: SG_GET_RESERVED_SIZE=%d\n",
+ __func__, val);
return put_user(val, ip);
case SG_SET_COMMAND_Q:
+ SG_LOG(3, sfp, "%s: SG_SET_COMMAND_Q\n", __func__);
result = get_user(val, ip);
if (result)
return result;
sfp->cmd_q = val ? 1 : 0;
return 0;
case SG_GET_COMMAND_Q:
+ SG_LOG(3, sfp, "%s: SG_GET_COMMAND_Q\n", __func__);
return put_user((int) sfp->cmd_q, ip);
case SG_SET_KEEP_ORPHAN:
+ SG_LOG(3, sfp, "%s: SG_SET_KEEP_ORPHAN\n", __func__);
result = get_user(val, ip);
if (result)
return result;
sfp->keep_orphan = val;
return 0;
case SG_GET_KEEP_ORPHAN:
+ SG_LOG(3, sfp, "%s: SG_GET_KEEP_ORPHAN\n", __func__);
return put_user((int) sfp->keep_orphan, ip);
+ case SG_GET_VERSION_NUM:
+ SG_LOG(3, sfp, "%s: SG_GET_VERSION_NUM\n", __func__);
+ return put_user(sg_version_num, ip);
+ case SG_GET_REQUEST_TABLE:
+ return sg_ctl_req_tbl(sfp, p);
+ case SG_SCSI_RESET:
+ SG_LOG(3, sfp, "%s: SG_SCSI_RESET\n", __func__);
+ break;
+ case SG_SET_TIMEOUT:
+ SG_LOG(3, sfp, "%s: SG_SET_TIMEOUT\n", __func__);
+ result = get_user(val, ip);
+ if (result)
+ return result;
+ if (val < 0)
+ return -EIO;
+ if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
+ val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
+ INT_MAX);
+ sfp->timeout_user = val;
+ sfp->timeout = mult_frac(val, HZ, USER_HZ);
+ return 0;
+ case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
+ /* strange ..., for backward compatibility */
+ SG_LOG(3, sfp, "%s: SG_GET_TIMEOUT\n", __func__);
+ return sfp->timeout_user;
+ case SG_SET_FORCE_LOW_DMA:
+ /*
+ * N.B. This ioctl never worked properly, but failed to
+ * return an error value. So returning '0' to keep
+ * compatibility with legacy applications.
+ */
+ SG_LOG(3, sfp, "%s: SG_SET_FORCE_LOW_DMA\n", __func__);
+ return 0;
+ case SG_GET_LOW_DMA:
+ SG_LOG(3, sfp, "%s: SG_GET_LOW_DMA\n", __func__);
+ return put_user((int)sdev->host->unchecked_isa_dma, ip);
case SG_NEXT_CMD_LEN:
+ SG_LOG(3, sfp, "%s: SG_NEXT_CMD_LEN\n", __func__);
result = get_user(val, ip);
if (result)
return result;
@@ -1170,75 +1247,73 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
return -ENOMEM;
sfp->next_cmd_len = (val > 0) ? val : 0;
return 0;
- case SG_GET_VERSION_NUM:
- return put_user(sg_version_num, ip);
case SG_GET_ACCESS_COUNT:
+ SG_LOG(3, sfp, "%s: SG_GET_ACCESS_COUNT\n", __func__);
/* faked - we don't have a real access count anymore */
- val = (sdp->device ? 1 : 0);
+ val = (sdev ? 1 : 0);
return put_user(val, ip);
- case SG_GET_REQUEST_TABLE:
- {
- sg_req_info_t *rinfo;
-
- rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
- GFP_KERNEL);
- if (!rinfo)
- return -ENOMEM;
- spin_lock_irqsave(&sfp->rq_list_lock, iflags);
- sg_fill_request_table(sfp, rinfo);
- spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- result = copy_to_user(p, rinfo,
- SZ_SG_REQ_INFO * SG_MAX_QUEUE);
- result = result ? -EFAULT : 0;
- kfree(rinfo);
- return result;
- }
case SG_EMULATED_HOST:
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- return put_user(sdp->device->host->hostt->emulated, ip);
+ SG_LOG(3, sfp, "%s: SG_EMULATED_HOST\n", __func__);
+ return put_user(sdev->host->hostt->emulated, ip);
case SCSI_IOCTL_SEND_COMMAND:
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
+ SG_LOG(3, sfp, "%s: SCSI_IOCTL_SEND_COMMAND\n", __func__);
+ return sg_scsi_ioctl(sdev->request_queue, NULL, filp->f_mode,
+ p);
case SG_SET_DEBUG:
+ SG_LOG(3, sfp, "%s: SG_SET_DEBUG\n", __func__);
result = get_user(val, ip);
if (result)
return result;
assign_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm, val);
return 0;
case BLKSECTGET:
- return put_user(max_sectors_bytes(sdp->device->request_queue),
- ip);
+ SG_LOG(3, sfp, "%s: BLKSECTGET\n", __func__);
+ return put_user(max_sectors_bytes(sdev->request_queue), ip);
case BLKTRACESETUP:
- return blk_trace_setup(sdp->device->request_queue,
+ SG_LOG(3, sfp, "%s: BLKTRACESETUP\n", __func__);
+ return blk_trace_setup(sdev->request_queue,
sdp->disk->disk_name,
MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
NULL, p);
case BLKTRACESTART:
- return blk_trace_startstop(sdp->device->request_queue, 1);
+ SG_LOG(3, sfp, "%s: BLKTRACESTART\n", __func__);
+ return blk_trace_startstop(sdev->request_queue, 1);
case BLKTRACESTOP:
- return blk_trace_startstop(sdp->device->request_queue, 0);
+ SG_LOG(3, sfp, "%s: BLKTRACESTOP\n", __func__);
+ return blk_trace_startstop(sdev->request_queue, 0);
case BLKTRACETEARDOWN:
- return blk_trace_remove(sdp->device->request_queue);
+ SG_LOG(3, sfp, "%s: BLKTRACETEARDOWN\n", __func__);
+ return blk_trace_remove(sdev->request_queue);
case SCSI_IOCTL_GET_IDLUN:
+ SG_LOG(3, sfp, "%s: SCSI_IOCTL_GET_IDLUN %s\n", __func__,
+ pmlp);
+ break;
case SCSI_IOCTL_GET_BUS_NUMBER:
+ SG_LOG(3, sfp, "%s: SCSI_IOCTL_GET_BUS_NUMBER%s\n",
+ __func__, pmlp);
+ break;
case SCSI_IOCTL_PROBE_HOST:
+ SG_LOG(3, sfp, "%s: SCSI_IOCTL_PROBE_HOST%s",
+ __func__, pmlp);
+ break;
case SG_GET_TRANSFORM:
- case SG_SCSI_RESET:
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
+ SG_LOG(3, sfp, "%s: SG_GET_TRANSFORM%s\n", __func__, pmlp);
+ break;
+ case SG_SET_TRANSFORM:
+ SG_LOG(3, sfp, "%s: SG_SET_TRANSFORM%s\n", __func__, pmlp);
break;
default:
+ SG_LOG(3, sfp, "%s: unrecognized ioctl [0x%x]%s\n",
+ __func__, cmd_in, pmlp);
if (read_only)
- return -EPERM; /* don't know so take safe approach */
+ return -EPERM; /* don't know, so take safer approach */
break;
}
result = sg_allow_if_err_recovery(sdp, filp->f_flags & O_NDELAY);
if (result)
return result;
- return scsi_ioctl(sdp->device, cmd_in, p);
+ return scsi_ioctl(sdev, cmd_in, p);
}
#if IS_ENABLED(CONFIG_COMPAT)
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 13/23] sg: ioctl handling
2019-10-08 7:50 ` [PATCH v5 13/23] sg: ioctl handling Douglas Gilbert
@ 2019-10-18 10:12 ` Hannes Reinecke
2019-10-24 2:47 ` Douglas Gilbert
0 siblings, 1 reply; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:12 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Shorten sg_ioctl() by adding some helper functions. sg_ioctl()
> is the main entry point for ioctls used on this driver's
> devices.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 325 ++++++++++++++++++++++++++++------------------
> 1 file changed, 200 insertions(+), 125 deletions(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 2796fef42837..90753f7759c7 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -72,6 +72,9 @@ static char *sg_version_date = "20190606";
> */
> #define SG_MAX_CDB_SIZE 252
>
> +#define uptr64(val) ((void __user *)(uintptr_t)(val))
> +#define cuptr64(val) ((const void __user *)(uintptr_t)(val))
> +
> #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
>
> /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
These defines are used only once; I'd rather drop them and do the
conversion in-place.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* Re: [PATCH v5 13/23] sg: ioctl handling
2019-10-18 10:12 ` Hannes Reinecke
@ 2019-10-24 2:47 ` Douglas Gilbert
0 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-24 2:47 UTC (permalink / raw)
To: Hannes Reinecke, linux-scsi; +Cc: martin.petersen, jejb
On 2019-10-18 6:12 a.m., Hannes Reinecke wrote:
> On 10/8/19 9:50 AM, Douglas Gilbert wrote:
>> Shorten sg_ioctl() by adding some helper functions. sg_ioctl()
>> is the main entry point for ioctls used on this driver's
>> devices.
>>
>> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
>> ---
>> drivers/scsi/sg.c | 325 ++++++++++++++++++++++++++++------------------
>> 1 file changed, 200 insertions(+), 125 deletions(-)
>>
>> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
>> index 2796fef42837..90753f7759c7 100644
>> --- a/drivers/scsi/sg.c
>> +++ b/drivers/scsi/sg.c
>> @@ -72,6 +72,9 @@ static char *sg_version_date = "20190606";
>> */
>> #define SG_MAX_CDB_SIZE 252
>>
>> +#define uptr64(val) ((void __user *)(uintptr_t)(val))
>> +#define cuptr64(val) ((const void __user *)(uintptr_t)(val))
>> +
>> #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
>>
>> /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
>
> These defines are used only once; I'd rather drop them and do the
> conversion in-place.
Okay, I'll take them out. And they will go back in in patch 28
as their main use is to handle the way the sg v4 interface
send pointers through 64 bit integers. The first one should be
familiar to anyone who has worked on block/bsg.h .
Doug Gilbert
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 14/23] sg: split sg_read
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (12 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 13/23] sg: ioctl handling Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:15 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 15/23] sg: sg_common_write add structure for arguments Douglas Gilbert
` (8 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
As sg_read() is getting quite long, split out the v1 and v2
processing into sg_rd_v1v2(). Rename sg_new_read() to
sg_v3_receive() as the v3 interface is now older than the v4
interface which is being added in a later patch.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 273 +++++++++++++++++++++++-----------------------
1 file changed, 135 insertions(+), 138 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 90753f7759c7..cbd75e34ca4b 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -760,17 +760,12 @@ sg_get_rq_mark(struct sg_fd *sfp, int pack_id)
}
static ssize_t
-sg_new_read(struct sg_fd *sfp, char __user *buf, size_t count,
- struct sg_request *srp)
+sg_v3_receive(struct sg_fd *sfp, char __user *buf, struct sg_request *srp)
{
struct sg_io_hdr *hp = &srp->header;
int err = 0, err2;
int len;
- if (count < SZ_SG_IO_HDR) {
- err = -EINVAL;
- goto err_out;
- }
hp->sb_len_wr = 0;
if ((hp->mx_sb_len > 0) && hp->sbp) {
if ((CHECK_CONDITION & hp->masked_status) ||
@@ -791,14 +786,15 @@ sg_new_read(struct sg_fd *sfp, char __user *buf, size_t count,
}
if (hp->masked_status || hp->host_status || hp->driver_status)
hp->info |= SG_INFO_CHECK;
- if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
+ if (copy_to_user(buf, hp, SZ_SG_IO_HDR))
err = -EFAULT;
- goto err_out;
- }
+
err_out:
err2 = sg_finish_scsi_blk_rq(srp);
+ if (err2)
+ err = err ? err : err2;
sg_remove_request(sfp, srp);
- return err ? : err2 ? : count;
+ return err ? err : 0;
}
static int
@@ -813,164 +809,165 @@ srp_done(struct sg_fd *sfp, struct sg_request *srp)
return ret;
}
-static ssize_t
-sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
+static int
+sg_rd_v1v2(void __user *buf, int count, struct sg_fd *sfp,
+ struct sg_request *srp)
{
- struct sg_device *sdp;
- struct sg_fd *sfp;
- struct sg_request *srp;
- int req_pack_id = -1;
- int ret = 0;
- struct sg_io_hdr *hp;
- struct sg_header *old_hdr = NULL;
-
- /*
- * This could cause a response to be stranded. Close the associated
- * file descriptor to free up any resources being held.
- */
- ret = sg_check_file_access(filp, __func__);
- if (ret)
- return ret;
-
- sfp = filp->private_data;
- sdp = sfp->parentdp;
- SG_LOG(3, sfp, "%s: read() count=%d\n", __func__, (int)count);
- ret = sg_allow_if_err_recovery(sdp, false);
- if (ret)
- return ret;
-
- if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
- old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
- if (!old_hdr)
- return -ENOMEM;
- if (copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
- ret = -EFAULT;
- goto free_old_hdr;
- }
- if (old_hdr->reply_len < 0) {
- if (count >= SZ_SG_IO_HDR) {
- struct sg_io_hdr *new_hdr;
-
- new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
- if (!new_hdr) {
- ret = -ENOMEM;
- goto free_old_hdr;
- }
- ret = copy_from_user(new_hdr, buf,
- SZ_SG_IO_HDR);
- req_pack_id = new_hdr->pack_id;
- kfree(new_hdr);
- if (ret) {
- ret = -EFAULT;
- goto free_old_hdr;
- }
- }
- } else
- req_pack_id = old_hdr->pack_id;
- }
- srp = sg_get_rq_mark(sfp, req_pack_id);
- if (!srp) { /* now wait on packet to arrive */
- if (SG_IS_DETACHING(sdp)) {
- ret = -ENODEV;
- goto free_old_hdr;
- }
- if (filp->f_flags & O_NONBLOCK) {
- ret = -EAGAIN;
- goto free_old_hdr;
- }
- ret = wait_event_interruptible
- (sfp->read_wait,
- (SG_IS_DETACHING(sdp) ||
- (srp = sg_get_rq_mark(sfp, req_pack_id))));
- if (SG_IS_DETACHING(sdp)) {
- ret = -ENODEV;
- goto free_old_hdr;
- }
- if (ret) {
- /* -ERESTARTSYS as signal hit process */
- goto free_old_hdr;
- }
- }
- if (srp->header.interface_id != '\0') {
- ret = sg_new_read(sfp, buf, count, srp);
- goto free_old_hdr;
- }
-
- hp = &srp->header;
- if (old_hdr == NULL) {
- old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
- if (!old_hdr) {
- ret = -ENOMEM;
- goto free_old_hdr;
- }
- }
- memset(old_hdr, 0, SZ_SG_HEADER);
- old_hdr->reply_len = (int) hp->timeout;
- old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
- old_hdr->pack_id = hp->pack_id;
- old_hdr->twelve_byte =
- ((srp->data.cmd_opcode >= 0xc0) && (hp->cmd_len == 12)) ? 1 : 0;
- old_hdr->target_status = hp->masked_status;
- old_hdr->host_status = hp->host_status;
- old_hdr->driver_status = hp->driver_status;
- if ((hp->masked_status & CHECK_CONDITION) ||
- (hp->driver_status & DRIVER_SENSE))
- memcpy(old_hdr->sense_buffer, srp->sense_b,
- sizeof(old_hdr->sense_buffer));
- switch (hp->host_status) {
+ int res = 0;
+ struct sg_io_hdr *sh3p = &srp->header;
+ struct sg_header *h2p;
+ struct sg_header a_v2hdr;
+
+ h2p = &a_v2hdr;
+ memset(h2p, 0, SZ_SG_HEADER);
+ h2p->reply_len = (int)sh3p->timeout;
+ h2p->pack_len = h2p->reply_len; /* old, strange behaviour */
+ h2p->pack_id = sh3p->pack_id;
+ h2p->twelve_byte = (srp->data.cmd_opcode >= 0xc0 &&
+ sh3p->cmd_len == 12);
+ h2p->target_status = sh3p->masked_status;
+ h2p->host_status = sh3p->host_status;
+ h2p->driver_status = sh3p->driver_status;
+ if ((CHECK_CONDITION & h2p->target_status) ||
+ (DRIVER_SENSE & sh3p->driver_status)) {
+ memcpy(h2p->sense_buffer, srp->sense_b,
+ sizeof(h2p->sense_buffer));
+ }
+ switch (h2p->host_status) {
/*
- * This setup of 'result' is for backward compatibility and is best
- * ignored by the user who should use target, host + driver status
+ * This foolowing setting of 'result' is for backward compatibility
+ * and is best ignored by the user who should use target, host and
+ * driver status.
*/
case DID_OK:
case DID_PASSTHROUGH:
case DID_SOFT_ERROR:
- old_hdr->result = 0;
+ h2p->result = 0;
break;
case DID_NO_CONNECT:
case DID_BUS_BUSY:
case DID_TIME_OUT:
- old_hdr->result = EBUSY;
+ h2p->result = EBUSY;
break;
case DID_BAD_TARGET:
case DID_ABORT:
case DID_PARITY:
case DID_RESET:
case DID_BAD_INTR:
- old_hdr->result = EIO;
+ h2p->result = EIO;
break;
case DID_ERROR:
- old_hdr->result = (srp->sense_b[0] == 0 &&
- hp->masked_status == GOOD) ? 0 : EIO;
+ h2p->result = (h2p->target_status == GOOD) ? 0 : EIO;
break;
default:
- old_hdr->result = EIO;
+ h2p->result = EIO;
break;
}
/* Now copy the result back to the user buffer. */
if (count >= SZ_SG_HEADER) {
- if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
- ret = -EFAULT;
- goto free_old_hdr;
- }
+ if (copy_to_user(buf, h2p, SZ_SG_HEADER))
+ return -EFAULT;
buf += SZ_SG_HEADER;
- if (count > old_hdr->reply_len)
- count = old_hdr->reply_len;
+ if (count > h2p->reply_len)
+ count = h2p->reply_len;
if (count > SZ_SG_HEADER) {
- if (sg_rd_append(srp, buf, count - SZ_SG_HEADER)) {
- ret = -EFAULT;
- goto free_old_hdr;
- }
+ if (sg_rd_append(srp, buf, count - SZ_SG_HEADER))
+ return -EFAULT;
}
} else
- count = (old_hdr->result == 0) ? 0 : -EIO;
+ res = (h2p->result == 0) ? 0 : -EIO;
sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
- ret = count;
-free_old_hdr:
- kfree(old_hdr);
- return ret;
+ return res;
+}
+
+static ssize_t
+sg_read(struct file *filp, char __user *p, size_t count, loff_t *ppos)
+{
+ bool could_be_v3;
+ bool non_block = !!(filp->f_flags & O_NONBLOCK);
+ int want_id = -1;
+ int hlen, ret;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
+ struct sg_request *srp;
+ struct sg_header *h2p = NULL;
+ struct sg_io_hdr a_sg_io_hdr;
+
+ /*
+ * This could cause a response to be stranded. Close the associated
+ * file descriptor to free up any resources being held.
+ */
+ ret = sg_check_file_access(filp, __func__);
+ if (ret)
+ return ret;
+
+ sfp = filp->private_data;
+ sdp = sfp->parentdp;
+ SG_LOG(3, sfp, "%s: read() count=%d\n", __func__, (int)count);
+ ret = sg_allow_if_err_recovery(sdp, false);
+ if (ret)
+ return ret;
+
+ could_be_v3 = (count >= SZ_SG_IO_HDR);
+ hlen = could_be_v3 ? SZ_SG_IO_HDR : SZ_SG_HEADER;
+ h2p = (struct sg_header *)&a_sg_io_hdr;
+
+ if (sfp->force_packid && count >= hlen) {
+ /*
+ * Even though this is a user space read() system call, this
+ * code is cheating to fetch the pack_id.
+ * Only need first three 32 bit ints to determine interface.
+ */
+ if (unlikely(copy_from_user(h2p, p, 3 * sizeof(int))))
+ return -EFAULT;
+ if (h2p->reply_len < 0 && could_be_v3) {
+ struct sg_io_hdr *v3_hdr = (struct sg_io_hdr *)h2p;
+
+ if (likely(v3_hdr->interface_id == 'S')) {
+ struct sg_io_hdr __user *h3_up;
+
+ h3_up = (struct sg_io_hdr __user *)p;
+ ret = get_user(want_id, &h3_up->pack_id);
+ if (unlikely(ret))
+ return ret;
+ } else if (v3_hdr->interface_id == 'Q') {
+ pr_info_once("sg: %s: v4 interface%s here\n",
+ __func__, " disallowed");
+ return -EPERM;
+ } else {
+ return -EPERM;
+ }
+ } else { /* for v1+v2 interfaces, this is the 3rd integer */
+ want_id = h2p->pack_id;
+ }
+ }
+ srp = sg_get_rq_mark(sfp, want_id);
+ if (!srp) { /* now wait on packet to arrive */
+ if (SG_IS_DETACHING(sdp))
+ return -ENODEV;
+ if (non_block) /* O_NONBLOCK or v3::flags & SGV4_FLAG_IMMED */
+ return -EAGAIN;
+ ret = wait_event_interruptible
+ (sfp->read_wait,
+ (SG_IS_DETACHING(sdp) ||
+ (srp = sg_get_rq_mark(sfp, want_id))));
+ if (SG_IS_DETACHING(sdp))
+ return -ENODEV;
+ if (ret) /* -ERESTARTSYS as signal hit process */
+ return ret;
+ }
+ if (srp->header.interface_id == '\0') {
+ ret = sg_rd_v1v2(p, (int)count, sfp, srp);
+ } else {
+ if ((int)count < SZ_SG_IO_HDR)
+ return -EINVAL;
+ ret = sg_v3_receive(sfp, p, srp);
+ }
+ if (ret < 0)
+ SG_LOG(1, sfp, "%s: negated errno: %d\n", __func__, ret);
+ return ret < 0 ? ret : (int)count;
}
static int
@@ -1043,7 +1040,7 @@ sg_ctl_sg_io(struct file *filp, struct sg_device *sdp, struct sg_fd *sfp,
if (srp->done) {
srp->done = 2;
spin_unlock_irq(&sfp->rq_list_lock);
- res = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
+ res = sg_v3_receive(sfp, p, srp);
return (res < 0) ? res : 0;
}
srp->orphan = 1;
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 14/23] sg: split sg_read
2019-10-08 7:50 ` [PATCH v5 14/23] sg: split sg_read Douglas Gilbert
@ 2019-10-18 10:15 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:15 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> As sg_read() is getting quite long, split out the v1 and v2
> processing into sg_rd_v1v2(). Rename sg_new_read() to
> sg_v3_receive() as the v3 interface is now older than the v4
> interface which is being added in a later patch.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 273 +++++++++++++++++++++++-----------------------
> 1 file changed, 135 insertions(+), 138 deletions(-)
>
Please use consistent naming.
Either 'sg_v3_receive', 'sg_v1v2_read' etc, or
'sg_receive_v3', 'sg_read_v1v2' etc.
And decide whether to use abbreviated or full names.
IE either sg_read_v1v2 or sg_rd_v1v2, but if the latter than
I would also prefer to have 'sg_rcv_v3'.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 15/23] sg: sg_common_write add structure for arguments
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (13 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 14/23] sg: split sg_read Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:16 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 16/23] sg: rework sg_vma_fault Douglas Gilbert
` (7 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
As the number of arguments to sg_common_write() starts to grow
(more in later patches) add a structure to hold most of these
arguments.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 47 ++++++++++++++++++++++++++++++++---------------
1 file changed, 32 insertions(+), 15 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index cbd75e34ca4b..903faafaeff9 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -177,6 +177,13 @@ struct sg_device { /* holds the state of each scsi generic device */
struct kref d_ref;
};
+struct sg_comm_wr_t { /* arguments to sg_common_write() */
+ int timeout;
+ int blocking;
+ struct sg_request *srp;
+ u8 *cmnd;
+};
+
/* tasklet or soft irq callback */
static void sg_rq_end_io(struct request *rq, blk_status_t status);
/* Declarations of other static functions used before they are defined */
@@ -189,8 +196,7 @@ static ssize_t sg_submit(struct sg_fd *sfp, struct file *filp,
const char __user *buf, size_t count, bool blocking,
bool read_only, bool sg_io_owned,
struct sg_request **o_srp);
-static int sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
- u8 *cmnd, int timeout, int blocking);
+static int sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwp);
static int sg_rd_append(struct sg_request *srp, void __user *outp,
int num_xfer);
static void sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
@@ -495,6 +501,7 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
struct sg_io_hdr v3hdr;
struct sg_header *ohp = &ov2hdr;
struct sg_io_hdr *h3p = &v3hdr;
+ struct sg_comm_wr_t cwr;
u8 cmnd[SG_MAX_CDB_SIZE];
res = sg_check_file_access(filp, __func__);
@@ -594,7 +601,11 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
input_size, (unsigned int) cmnd[0],
current->comm);
}
- res = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
+ cwr.timeout = sfp->timeout;
+ cwr.blocking = blocking;
+ cwr.srp = srp;
+ cwr.cmnd = cmnd;
+ res = sg_common_write(sfp, &cwr);
return (res < 0) ? res : count;
}
@@ -617,6 +628,7 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
int k;
struct sg_request *srp;
struct sg_io_hdr *hp;
+ struct sg_comm_wr_t cwr;
u8 cmnd[SG_MAX_CDB_SIZE];
int timeout;
unsigned long ul_timeout;
@@ -667,23 +679,28 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
sg_remove_request(sfp, srp);
return -EPERM;
}
- k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
+ cwr.timeout = timeout;
+ cwr.blocking = blocking;
+ cwr.srp = srp;
+ cwr.cmnd = cmnd;
+ k = sg_common_write(sfp, &cwr);
if (k < 0)
return k;
if (o_srp)
- *o_srp = srp;
+ *o_srp = cwr.srp;
return count;
}
static int
-sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
- u8 *cmnd, int timeout, int blocking)
+sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp)
{
- int k, at_head;
+ bool at_head;
+ int k;
struct sg_device *sdp = sfp->parentdp;
+ struct sg_request *srp = cwrp->srp;
struct sg_io_hdr *hp = &srp->header;
- srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
+ srp->data.cmd_opcode = cwrp->cmnd[0]; /* hold opcode of command */
hp->status = 0;
hp->masked_status = 0;
hp->msg_status = 0;
@@ -692,12 +709,12 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
hp->driver_status = 0;
hp->resid = 0;
SG_LOG(4, sfp, "%s: opcode=0x%02x, cmd_sz=%d\n", __func__,
- (int)cmnd[0], hp->cmd_len);
+ (int)cwrp->cmnd[0], hp->cmd_len);
if (hp->dxfer_len >= SZ_256M)
return -EINVAL;
- k = sg_start_req(srp, cmnd);
+ k = sg_start_req(srp, cwrp->cmnd);
if (k) {
SG_LOG(1, sfp, "%s: start_req err=%d\n", __func__, k);
sg_finish_scsi_blk_rq(srp);
@@ -719,13 +736,13 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
hp->duration = jiffies_to_msecs(jiffies);
if (hp->interface_id != '\0' && /* v3 (or later) interface */
(SG_FLAG_Q_AT_TAIL & hp->flags))
- at_head = 0;
+ at_head = false;
else
- at_head = 1;
+ at_head = true;
- if (!blocking)
+ if (!srp->sg_io_owned)
atomic_inc(&sfp->submitted);
- srp->rq->timeout = timeout;
+ srp->rq->timeout = cwrp->timeout;
kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
srp->rq, at_head, sg_rq_end_io);
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 15/23] sg: sg_common_write add structure for arguments
2019-10-08 7:50 ` [PATCH v5 15/23] sg: sg_common_write add structure for arguments Douglas Gilbert
@ 2019-10-18 10:16 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:16 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> As the number of arguments to sg_common_write() starts to grow
> (more in later patches) add a structure to hold most of these
> arguments.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 47 ++++++++++++++++++++++++++++++++---------------
> 1 file changed, 32 insertions(+), 15 deletions(-)
>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 16/23] sg: rework sg_vma_fault
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (14 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 15/23] sg: sg_common_write add structure for arguments Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:17 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 17/23] sg: rework sg_mmap Douglas Gilbert
` (6 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Simple refactoring of the sg_vma_fault() function.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 33 +++++++++++++++++++++++----------
1 file changed, 23 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 903faafaeff9..befcbfbcece1 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1389,14 +1389,16 @@ sg_fasync(int fd, struct file *filp, int mode)
return fasync_helper(fd, filp, mode, &sfp->async_qp);
}
+/* Note: the error return: VM_FAULT_SIGBUS causes a "bus error" */
static vm_fault_t
sg_vma_fault(struct vm_fault *vmf)
{
- struct vm_area_struct *vma = vmf->vma;
- struct sg_fd *sfp;
+ int k, length;
unsigned long offset, len, sa;
+ struct vm_area_struct *vma = vmf->vma;
struct sg_scatter_hold *rsv_schp;
- int k, length;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
const char *nbp = "==NULL, bad";
if (!vma) {
@@ -1408,20 +1410,31 @@ sg_vma_fault(struct vm_fault *vmf)
pr_warn("%s: sfp%s\n", __func__, nbp);
goto out_err;
}
+ sdp = sfp->parentdp;
+ if (sdp && unlikely(SG_IS_DETACHING(sdp))) {
+ SG_LOG(1, sfp, "%s: device detaching\n", __func__);
+ goto out_err;
+ }
rsv_schp = &sfp->reserve;
offset = vmf->pgoff << PAGE_SHIFT;
- if (offset >= rsv_schp->buflen)
- return VM_FAULT_SIGBUS;
+ if (offset >= (unsigned int)rsv_schp->buflen) {
+ SG_LOG(1, sfp, "%s: offset[%lu] >= rsv.buflen\n", __func__,
+ offset);
+ goto out_err;
+ }
sa = vma->vm_start;
SG_LOG(3, sfp, "%s: vm_start=0x%lx, off=%lu\n", __func__, sa, offset);
length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
- for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) {
+ for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; ++k) {
len = vma->vm_end - sa;
- len = (len < length) ? len : length;
+ len = min_t(int, len, (int)length);
if (offset < len) {
- struct page *page = nth_page(rsv_schp->pages[k],
- offset >> PAGE_SHIFT);
- get_page(page); /* increment page count */
+ struct page *page;
+ struct page *pp;
+
+ pp = rsv_schp->pages[k];
+ page = nth_page(pp, offset >> PAGE_SHIFT);
+ get_page(page); /* increment page count */
vmf->page = page;
return 0; /* success */
}
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 16/23] sg: rework sg_vma_fault
2019-10-08 7:50 ` [PATCH v5 16/23] sg: rework sg_vma_fault Douglas Gilbert
@ 2019-10-18 10:17 ` Hannes Reinecke
2019-10-24 3:07 ` Douglas Gilbert
0 siblings, 1 reply; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:17 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Simple refactoring of the sg_vma_fault() function.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 33 +++++++++++++++++++++++----------
> 1 file changed, 23 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 903faafaeff9..befcbfbcece1 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -1389,14 +1389,16 @@ sg_fasync(int fd, struct file *filp, int mode)
> return fasync_helper(fd, filp, mode, &sfp->async_qp);
> }
>
> +/* Note: the error return: VM_FAULT_SIGBUS causes a "bus error" */
> static vm_fault_t
> sg_vma_fault(struct vm_fault *vmf)
> {
> - struct vm_area_struct *vma = vmf->vma;
> - struct sg_fd *sfp;
> + int k, length;
> unsigned long offset, len, sa;
> + struct vm_area_struct *vma = vmf->vma;
> struct sg_scatter_hold *rsv_schp;
> - int k, length;
> + struct sg_device *sdp;
> + struct sg_fd *sfp;
> const char *nbp = "==NULL, bad";
>
> if (!vma) {
Of course, one would prefer normal kernel-doc style for the comment ...
Otherwise:
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread* Re: [PATCH v5 16/23] sg: rework sg_vma_fault
2019-10-18 10:17 ` Hannes Reinecke
@ 2019-10-24 3:07 ` Douglas Gilbert
0 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-24 3:07 UTC (permalink / raw)
To: Hannes Reinecke, linux-scsi; +Cc: martin.petersen, jejb
On 2019-10-18 6:17 a.m., Hannes Reinecke wrote:
> On 10/8/19 9:50 AM, Douglas Gilbert wrote:
>> Simple refactoring of the sg_vma_fault() function.
>>
>> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
>> ---
>> drivers/scsi/sg.c | 33 +++++++++++++++++++++++----------
>> 1 file changed, 23 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
>> index 903faafaeff9..befcbfbcece1 100644
>> --- a/drivers/scsi/sg.c
>> +++ b/drivers/scsi/sg.c
>> @@ -1389,14 +1389,16 @@ sg_fasync(int fd, struct file *filp, int mode)
>> return fasync_helper(fd, filp, mode, &sfp->async_qp);
>> }
>>
>> +/* Note: the error return: VM_FAULT_SIGBUS causes a "bus error" */
>> static vm_fault_t
>> sg_vma_fault(struct vm_fault *vmf)
>> {
>> - struct vm_area_struct *vma = vmf->vma;
>> - struct sg_fd *sfp;
>> + int k, length;
>> unsigned long offset, len, sa;
>> + struct vm_area_struct *vma = vmf->vma;
>> struct sg_scatter_hold *rsv_schp;
>> - int k, length;
>> + struct sg_device *sdp;
>> + struct sg_fd *sfp;
>> const char *nbp = "==NULL, bad";
>>
>> if (!vma) {
> Of course, one would prefer normal kernel-doc style for the comment ...
For static functions, that is left up to the discretion of the maintainer,
according to the document to which you refer :-)
I prefer comments that aren't compilable, IOWs that don't state the
bleeding obvious. While I was debugging sg_vma_fault() it took me a
while to understand why my test harness was crashing, hence that
comment.
Doug Gilbert
sg_vma_fault(
> Otherwise:
> Reviewed-by: Hannes Reinecke <hare@suse.com>
>
> Cheers,
>
> Hannes
>
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 17/23] sg: rework sg_mmap
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (15 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 16/23] sg: rework sg_vma_fault Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:18 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 18/23] sg: replace sg_allow_access Douglas Gilbert
` (5 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Simple rework of the sg_mmap() function.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index befcbfbcece1..2ad86aaaf74d 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1449,14 +1449,15 @@ static const struct vm_operations_struct sg_mmap_vm_ops = {
.fault = sg_vma_fault,
};
+/* Entry point for mmap(2) system call */
static int
sg_mmap(struct file *filp, struct vm_area_struct *vma)
{
- struct sg_fd *sfp;
- unsigned long req_sz, len, sa;
- struct sg_scatter_hold *rsv_schp;
int k, length;
int ret = 0;
+ unsigned long req_sz, len, sa;
+ struct sg_scatter_hold *rsv_schp;
+ struct sg_fd *sfp;
if (!filp || !vma)
return -ENXIO;
@@ -1469,19 +1470,23 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
SG_LOG(3, sfp, "%s: vm_start=%p, len=%d\n", __func__,
(void *)vma->vm_start, (int)req_sz);
if (vma->vm_pgoff)
- return -EINVAL; /* want no offset */
- rsv_schp = &sfp->reserve;
+ return -EINVAL; /* only an offset of 0 accepted */
+ /* Check reserve request is inactive and has large enough buffer */
mutex_lock(&sfp->f_mutex);
- if (req_sz > rsv_schp->buflen) {
- ret = -ENOMEM; /* cannot map more than reserved buffer */
+ if (sfp->res_in_use) {
+ ret = -EBUSY;
+ goto out;
+ }
+ rsv_schp = &sfp->reserve;
+ if (req_sz > (unsigned long)rsv_schp->buflen) {
+ ret = -ENOMEM;
goto out;
}
-
sa = vma->vm_start;
length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
- for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) {
+ for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; ++k) {
len = vma->vm_end - sa;
- len = (len < length) ? len : length;
+ len = min_t(unsigned long, len, (unsigned long)length);
sa += len;
}
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 17/23] sg: rework sg_mmap
2019-10-08 7:50 ` [PATCH v5 17/23] sg: rework sg_mmap Douglas Gilbert
@ 2019-10-18 10:18 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:18 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Simple rework of the sg_mmap() function.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 25 +++++++++++++++----------
> 1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index befcbfbcece1..2ad86aaaf74d 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -1449,14 +1449,15 @@ static const struct vm_operations_struct sg_mmap_vm_ops = {
> .fault = sg_vma_fault,
> };
>
> +/* Entry point for mmap(2) system call */
> static int
> sg_mmap(struct file *filp, struct vm_area_struct *vma)
> {
> - struct sg_fd *sfp;
> - unsigned long req_sz, len, sa;
> - struct sg_scatter_hold *rsv_schp;
> int k, length;
> int ret = 0;
> + unsigned long req_sz, len, sa;
> + struct sg_scatter_hold *rsv_schp;
> + struct sg_fd *sfp;
>
> if (!filp || !vma)
> return -ENXIO;
> @@ -1469,19 +1470,23 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
> SG_LOG(3, sfp, "%s: vm_start=%p, len=%d\n", __func__,
> (void *)vma->vm_start, (int)req_sz);
> if (vma->vm_pgoff)
> - return -EINVAL; /* want no offset */
> - rsv_schp = &sfp->reserve;
> + return -EINVAL; /* only an offset of 0 accepted */
> + /* Check reserve request is inactive and has large enough buffer */
> mutex_lock(&sfp->f_mutex);
> - if (req_sz > rsv_schp->buflen) {
> - ret = -ENOMEM; /* cannot map more than reserved buffer */
> + if (sfp->res_in_use) {
> + ret = -EBUSY;
> + goto out;
> + }
> + rsv_schp = &sfp->reserve;
> + if (req_sz > (unsigned long)rsv_schp->buflen) {
> + ret = -ENOMEM;
> goto out;
> }
> -
> sa = vma->vm_start;
> length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
> - for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) {
> + for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; ++k) {
> len = vma->vm_end - sa;
> - len = (len < length) ? len : length;
> + len = min_t(unsigned long, len, (unsigned long)length);
> sa += len;
> }
>
>
Some comment regarding kernel-doc applies here, too.
Anc the change in the 'for' condition above appears to be rather cosmetic...
Otherwise:
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 18/23] sg: replace sg_allow_access
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (16 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 17/23] sg: rework sg_mmap Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:20 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 19/23] sg: rework scatter gather handling Douglas Gilbert
` (4 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Replace the sg_allow_access() function with sg_fetch_cmnd()
which does a little more. Change sg_finish_scsi_blk_rq() from an
int to a void returning function. Rename sg_remove_request()
to sg_deact_request(). Other changes, mainly cosmetic.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 149 +++++++++++++++++++++++++---------------------
1 file changed, 80 insertions(+), 69 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 2ad86aaaf74d..5ac21e41be27 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -189,7 +189,7 @@ static void sg_rq_end_io(struct request *rq, blk_status_t status);
/* Declarations of other static functions used before they are defined */
static int sg_proc_init(void);
static int sg_start_req(struct sg_request *srp, u8 *cmd);
-static int sg_finish_scsi_blk_rq(struct sg_request *srp);
+static void sg_finish_scsi_blk_rq(struct sg_request *srp);
static int sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
int buff_size);
static ssize_t sg_submit(struct sg_fd *sfp, struct file *filp,
@@ -207,7 +207,7 @@ static void sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
static void sg_remove_sfp(struct kref *);
static struct sg_request *sg_add_request(struct sg_fd *sfp);
-static int sg_remove_request(struct sg_fd *sfp, struct sg_request *srp);
+static int sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_device *sg_get_dev(int dev);
static void sg_device_destroy(struct kref *kref);
@@ -545,7 +545,7 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
mutex_lock(&sfp->f_mutex);
if (sfp->next_cmd_len > 0) {
cmd_size = sfp->next_cmd_len;
- sfp->next_cmd_len = 0; /* reset so only this write() effected */
+ sfp->next_cmd_len = 0; /* reset, only this write() effected */
} else {
cmd_size = COMMAND_SIZE(opcode); /* old: SCSI command group */
if (opcode >= 0xc0 && ohp->twelve_byte)
@@ -559,7 +559,7 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
mxsize -= SZ_SG_HEADER;
input_size -= SZ_SG_HEADER;
if (input_size < 0) {
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return -EIO; /* User did not pass enough bytes for this command. */
}
h3p = &srp->header;
@@ -576,12 +576,12 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
h3p->dxfer_len = mxsize;
if (h3p->dxfer_direction == SG_DXFER_TO_DEV ||
h3p->dxfer_direction == SG_DXFER_TO_FROM_DEV)
- h3p->dxferp = (char __user *)p + cmd_size;
+ h3p->dxferp = (u8 __user *)p + cmd_size;
else
h3p->dxferp = NULL;
h3p->sbp = NULL;
- h3p->timeout = ohp->reply_len; /* structure abuse ... */
- h3p->flags = input_size; /* structure abuse ... */
+ h3p->timeout = ohp->reply_len; /* structure abuse ... */
+ h3p->flags = input_size; /* structure abuse ... */
h3p->pack_id = ohp->pack_id;
h3p->usr_ptr = NULL;
if (copy_from_user(cmnd, p, cmd_size))
@@ -610,14 +610,24 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
}
static int
-sg_allow_access(struct file *filp, u8 *cmd)
+sg_fetch_cmnd(struct file *filp, struct sg_fd *sfp, const u8 __user *u_cdbp,
+ int len, u8 *cdbp)
{
- struct sg_fd *sfp = filp->private_data;
-
- if (sfp->parentdp->device->type == TYPE_SCANNER)
- return 0;
-
- return blk_verify_command(cmd, filp->f_mode);
+ if (!u_cdbp || len < 6 || len > SG_MAX_CDB_SIZE)
+ return -EMSGSIZE;
+ if (copy_from_user(cdbp, u_cdbp, len))
+ return -EFAULT;
+ if (O_RDWR != (filp->f_flags & O_ACCMODE)) { /* read-only */
+ switch (sfp->parentdp->device->type) {
+ case TYPE_DISK:
+ case TYPE_RBC:
+ case TYPE_ZBC:
+ return blk_verify_command(cdbp, filp->f_mode);
+ default: /* SSC, SES, etc cbd_s may differ from SBC */
+ break;
+ }
+ }
+ return 0;
}
static ssize_t
@@ -625,12 +635,11 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
size_t count, bool blocking, bool read_only, bool sg_io_owned,
struct sg_request **o_srp)
{
- int k;
+ int k, res, timeout;
struct sg_request *srp;
struct sg_io_hdr *hp;
struct sg_comm_wr_t cwr;
u8 cmnd[SG_MAX_CDB_SIZE];
- int timeout;
unsigned long ul_timeout;
if (count < SZ_SG_IO_HDR)
@@ -644,40 +653,33 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
srp->sg_io_owned = sg_io_owned;
hp = &srp->header;
if (copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return -EFAULT;
}
if (hp->interface_id != 'S') {
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return -ENOSYS;
}
if (hp->flags & SG_FLAG_MMAP_IO) {
if (hp->dxfer_len > sfp->reserve.buflen) {
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
}
if (hp->flags & SG_FLAG_DIRECT_IO) {
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
}
if (sfp->res_in_use) {
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return -EBUSY; /* reserve buffer already being used */
}
}
ul_timeout = msecs_to_jiffies(srp->header.timeout);
timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
- if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
- sg_remove_request(sfp, srp);
- return -EMSGSIZE;
- }
- if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
- sg_remove_request(sfp, srp);
- return -EFAULT;
- }
- if (read_only && sg_allow_access(filp, cmnd)) {
- sg_remove_request(sfp, srp);
- return -EPERM;
+ res = sg_fetch_cmnd(filp, sfp, hp->cmdp, hp->cmd_len, cmnd);
+ if (res) {
+ sg_deact_request(sfp, srp);
+ return res;
}
cwr.timeout = timeout;
cwr.blocking = blocking;
@@ -718,7 +720,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp)
if (k) {
SG_LOG(1, sfp, "%s: start_req err=%d\n", __func__, k);
sg_finish_scsi_blk_rq(srp);
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return k; /* probably out of space --> ENOMEM */
}
if (SG_IS_DETACHING(sdp)) {
@@ -729,7 +731,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp)
}
sg_finish_scsi_blk_rq(srp);
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return -ENODEV;
}
@@ -776,11 +778,23 @@ sg_get_rq_mark(struct sg_fd *sfp, int pack_id)
return NULL;
}
+static int
+srp_done(struct sg_fd *sfp, struct sg_request *srp)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&sfp->rq_list_lock, flags);
+ ret = srp->done;
+ spin_unlock_irqrestore(&sfp->rq_list_lock, flags);
+ return ret;
+}
+
static ssize_t
sg_v3_receive(struct sg_fd *sfp, char __user *buf, struct sg_request *srp)
{
struct sg_io_hdr *hp = &srp->header;
- int err = 0, err2;
+ int err = 0;
int len;
hp->sb_len_wr = 0;
@@ -807,25 +821,11 @@ sg_v3_receive(struct sg_fd *sfp, char __user *buf, struct sg_request *srp)
err = -EFAULT;
err_out:
- err2 = sg_finish_scsi_blk_rq(srp);
- if (err2)
- err = err ? err : err2;
- sg_remove_request(sfp, srp);
+ sg_finish_scsi_blk_rq(srp);
+ sg_deact_request(sfp, srp);
return err ? err : 0;
}
-static int
-srp_done(struct sg_fd *sfp, struct sg_request *srp)
-{
- unsigned long flags;
- int ret;
-
- spin_lock_irqsave(&sfp->rq_list_lock, flags);
- ret = srp->done;
- spin_unlock_irqrestore(&sfp->rq_list_lock, flags);
- return ret;
-}
-
static int
sg_rd_v1v2(void __user *buf, int count, struct sg_fd *sfp,
struct sg_request *srp)
@@ -895,7 +895,7 @@ sg_rd_v1v2(void __user *buf, int count, struct sg_fd *sfp,
} else
res = (h2p->result == 0) ? 0 : -EIO;
sg_finish_scsi_blk_rq(srp);
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
return res;
}
@@ -1507,7 +1507,7 @@ sg_rq_end_io_usercontext(struct work_struct *work)
struct sg_fd *sfp = srp->parentfp;
sg_finish_scsi_blk_rq(srp);
- sg_remove_request(sfp, srp);
+ sg_deact_request(sfp, srp);
kref_put(&sfp->f_ref, sg_remove_sfp);
}
@@ -1632,7 +1632,7 @@ static const struct file_operations sg_fops = {
static struct class *sg_sysfs_class;
-static int sg_sysfs_valid = 0;
+static bool sg_sysfs_valid;
static struct sg_device *
sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
@@ -1865,7 +1865,7 @@ init_sg(void)
rc = PTR_ERR(sg_sysfs_class);
goto err_out;
}
- sg_sysfs_valid = 1;
+ sg_sysfs_valid = true;
rc = scsi_register_interface(&sg_interface);
if (0 == rc) {
sg_proc_init();
@@ -1892,7 +1892,7 @@ exit_sg(void)
remove_proc_subtree("scsi/sg", NULL);
scsi_unregister_interface(&sg_interface);
class_destroy(sg_sysfs_class);
- sg_sysfs_valid = 0;
+ sg_sysfs_valid = false;
unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
SG_MAX_DEVS);
idr_destroy(&sg_index_idr);
@@ -2027,10 +2027,10 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
return res;
}
-static int
+static void
sg_finish_scsi_blk_rq(struct sg_request *srp)
{
- int ret = 0;
+ int ret;
struct sg_fd *sfp = srp->parentfp;
struct sg_scatter_hold *req_schp = &srp->data;
@@ -2041,8 +2041,13 @@ sg_finish_scsi_blk_rq(struct sg_request *srp)
atomic_dec(&sfp->submitted);
atomic_dec(&sfp->waiting);
}
- if (srp->bio)
+ if (srp->bio) {
ret = blk_rq_unmap_user(srp->bio);
+ if (ret) /* -EINTR (-4) can be ignored */
+ SG_LOG(6, sfp, "%s: blk_rq_unmap_user() --> %d\n",
+ __func__, ret);
+ srp->bio = NULL;
+ }
if (srp->rq) {
scsi_req_free_cmd(scsi_req(srp->rq));
@@ -2053,8 +2058,6 @@ sg_finish_scsi_blk_rq(struct sg_request *srp)
sg_unlink_reserve(sfp, srp);
else
sg_remove_scat(sfp, req_schp);
-
- return ret;
}
static int
@@ -2298,7 +2301,7 @@ sg_add_request(struct sg_fd *sfp)
/* Return of 1 for found; 0 for not found */
static int
-sg_remove_request(struct sg_fd *sfp, struct sg_request *srp)
+sg_deact_request(struct sg_fd *sfp, struct sg_request *srp)
{
unsigned long iflags;
int res = 0;
@@ -2318,9 +2321,9 @@ sg_remove_request(struct sg_fd *sfp, struct sg_request *srp)
static struct sg_fd *
sg_add_sfp(struct sg_device *sdp)
{
- struct sg_fd *sfp;
unsigned long iflags;
int bufflen;
+ struct sg_fd *sfp;
sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
if (!sfp)
@@ -2366,10 +2369,16 @@ sg_add_sfp(struct sg_device *sdp)
static void
sg_remove_sfp_usercontext(struct work_struct *work)
{
+ unsigned long iflags;
struct sg_fd *sfp = container_of(work, struct sg_fd, ew_fd.work);
- struct sg_device *sdp = sfp->parentdp;
+ struct sg_device *sdp;
struct sg_request *srp;
- unsigned long iflags;
+
+ if (!sfp) {
+ pr_warn("sg: %s: sfp is NULL\n", __func__);
+ return;
+ }
+ sdp = sfp->parentdp;
/* Cleanup any responses which were never read(). */
spin_lock_irqsave(&sfp->rq_list_lock, iflags);
@@ -2390,17 +2399,19 @@ sg_remove_sfp_usercontext(struct work_struct *work)
SG_LOG(6, sfp, "%s: sfp=0x%p\n", __func__, sfp);
kfree(sfp);
- scsi_device_put(sdp->device);
- kref_put(&sdp->d_ref, sg_device_destroy);
+ if (sdp) {
+ scsi_device_put(sdp->device);
+ kref_put(&sdp->d_ref, sg_device_destroy);
+ }
module_put(THIS_MODULE);
}
static void
sg_remove_sfp(struct kref *kref)
{
+ unsigned long iflags;
struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
struct sg_device *sdp = sfp->parentdp;
- unsigned long iflags;
write_lock_irqsave(&sdp->sfd_lock, iflags);
list_del(&sfp->sfd_entry);
@@ -2615,7 +2626,7 @@ struct sg_proc_deviter {
static void *
dev_seq_start(struct seq_file *s, loff_t *pos)
{
- struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
+ struct sg_proc_deviter *it = kzalloc(sizeof(*it), GFP_KERNEL);
s->private = it;
if (! it)
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 18/23] sg: replace sg_allow_access
2019-10-08 7:50 ` [PATCH v5 18/23] sg: replace sg_allow_access Douglas Gilbert
@ 2019-10-18 10:20 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:20 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Replace the sg_allow_access() function with sg_fetch_cmnd()
> which does a little more. Change sg_finish_scsi_blk_rq() from an
> int to a void returning function. Rename sg_remove_request()
> to sg_deact_request(). Other changes, mainly cosmetic.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 149 +++++++++++++++++++++++++---------------------
> 1 file changed, 80 insertions(+), 69 deletions(-)
>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 19/23] sg: rework scatter gather handling
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (17 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 18/23] sg: replace sg_allow_access Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:22 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 20/23] sg: introduce request state machine Douglas Gilbert
` (3 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Rename sg_build_indirect() to sg_mk_sgat() and sg_remove_scat()
to sg_remove_sgat(). Re-implement those functions. Add
sg_calc_sgat_param() to calculate various scatter gather
list parameters. Some other minor clean-ups.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 275 +++++++++++++++++++++++++---------------------
1 file changed, 152 insertions(+), 123 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 5ac21e41be27..5b560f720993 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -93,7 +93,6 @@ static int def_reserved_size = -1; /* picks up init parameter */
static int sg_allow_dio = SG_ALLOW_DIO_DEF;
static int scatter_elem_sz = SG_SCATTER_SZ;
-static int scatter_elem_sz_prev = SG_SCATTER_SZ;
#define SG_DEF_SECTOR_SZ 512
@@ -148,6 +147,7 @@ struct sg_fd { /* holds the state of a file descriptor */
int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
atomic_t submitted; /* number inflight or awaiting read */
atomic_t waiting; /* number of requests awaiting read */
+ int sgat_elem_sz; /* initialized to scatter_elem_sz */
struct sg_scatter_hold reserve; /* buffer for this file descriptor */
struct list_head rq_list; /* head of request list */
struct fasync_struct *async_qp; /* used by asynchronous notification */
@@ -168,6 +168,7 @@ struct sg_device { /* holds the state of each scsi generic device */
struct mutex open_rel_lock; /* held when in open() or release() */
struct list_head sfds;
rwlock_t sfd_lock; /* protect access to sfd list */
+ int max_sgat_elems; /* adapter's max number of elements in sgat */
int max_sgat_sz; /* max number of bytes in sgat list */
u32 index; /* device index number */
atomic_t open_cnt; /* count of opens (perhaps < num(sfds) ) */
@@ -190,8 +191,8 @@ static void sg_rq_end_io(struct request *rq, blk_status_t status);
static int sg_proc_init(void);
static int sg_start_req(struct sg_request *srp, u8 *cmd);
static void sg_finish_scsi_blk_rq(struct sg_request *srp);
-static int sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
- int buff_size);
+static int sg_mk_sgat(struct sg_scatter_hold *schp, struct sg_fd *sfp,
+ int minlen);
static ssize_t sg_submit(struct sg_fd *sfp, struct file *filp,
const char __user *buf, size_t count, bool blocking,
bool read_only, bool sg_io_owned,
@@ -199,7 +200,7 @@ static ssize_t sg_submit(struct sg_fd *sfp, struct file *filp,
static int sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwp);
static int sg_rd_append(struct sg_request *srp, void __user *outp,
int num_xfer);
-static void sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
+static void sg_remove_sgat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
static void sg_build_reserve(struct sg_fd *sfp, int req_size);
static void sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp,
int size);
@@ -210,6 +211,7 @@ static struct sg_request *sg_add_request(struct sg_fd *sfp);
static int sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_device *sg_get_dev(int dev);
static void sg_device_destroy(struct kref *kref);
+static void sg_calc_sgat_param(struct sg_device *sdp);
#define SZ_SG_HEADER ((int)sizeof(struct sg_header)) /* v1 and v2 header */
#define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
@@ -355,7 +357,6 @@ sg_open(struct inode *inode, struct file *filp)
int min_dev = iminor(inode);
int op_flags = filp->f_flags;
int res;
- struct request_queue *q;
struct sg_device *sdp;
struct sg_fd *sfp;
@@ -414,16 +415,12 @@ sg_open(struct inode *inode, struct file *filp)
if (o_excl)
set_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm);
- if (atomic_read(&sdp->open_cnt) < 1) { /* no existing opens */
- clear_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm);
- q = sdp->device->request_queue;
- sdp->max_sgat_sz = queue_max_segments(q);
- }
+ if (atomic_read(&sdp->open_cnt) < 1) /* no existing opens */
+ sg_calc_sgat_param(sdp);
sfp = sg_add_sfp(sdp);
if (IS_ERR(sfp)) {
res = PTR_ERR(sfp);
- goto out_undo;
- }
+ goto out_undo; }
filp->private_data = sfp;
atomic_inc(&sdp->open_cnt);
@@ -993,10 +990,43 @@ max_sectors_bytes(struct request_queue *q)
unsigned int max_sectors = queue_max_sectors(q);
max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
-
return max_sectors << 9;
}
+/*
+ * Calculates sg_device::max_sgat_elems and sg_device::max_sgat_sz. It uses
+ * the device's request queue. If q not available sets max_sgat_elems to 1
+ * and max_sgat_sz to PAGE_SIZE. If potential max_sgat_sz is greater than
+ * 2^30 scales down the implied max_segment_size so the product of the
+ * max_segment_size and max_sgat_elems is less than or equal to 2^30 .
+ */
+static void
+sg_calc_sgat_param(struct sg_device *sdp)
+{
+ int sz;
+ u64 m;
+ struct scsi_device *sdev = sdp->device;
+ struct request_queue *q = sdev ? sdev->request_queue : NULL;
+
+ clear_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm);
+ if (!q) {
+ sdp->max_sgat_elems = 1;
+ sdp->max_sgat_sz = PAGE_SIZE;
+ return;
+ }
+ sdp->max_sgat_elems = queue_max_segments(q);
+ m = (u64)queue_max_segment_size(q) * queue_max_segments(q);
+ if (m < PAGE_SIZE) {
+ sdp->max_sgat_elems = 1;
+ sdp->max_sgat_sz = PAGE_SIZE;
+ return;
+ }
+ sz = (int)min_t(u64, m, 1 << 30);
+ if (sz == (1 << 30)) /* round down so: sz = elems * elem_sz */
+ sz = ((1 << 30) / sdp->max_sgat_elems) * sdp->max_sgat_elems;
+ sdp->max_sgat_sz = sz;
+}
+
static void
sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
{
@@ -1062,7 +1092,7 @@ sg_ctl_sg_io(struct file *filp, struct sg_device *sdp, struct sg_fd *sfp,
}
srp->orphan = 1;
spin_unlock_irq(&sfp->rq_list_lock);
- return res; /* -ERESTARTSYS because signal hit process */
+ return res;
}
static int
@@ -1073,8 +1103,7 @@ sg_set_reserved_sz(struct sg_fd *sfp, int want_rsv_sz)
sfp->res_in_use) {
return -EBUSY;
}
-
- sg_remove_scat(sfp, &sfp->reserve);
+ sg_remove_sgat(sfp, &sfp->reserve);
sg_build_reserve(sfp, want_rsv_sz);
}
return 0;
@@ -1504,8 +1533,18 @@ sg_rq_end_io_usercontext(struct work_struct *work)
{
struct sg_request *srp = container_of(work, struct sg_request,
ew_orph.work);
- struct sg_fd *sfp = srp->parentfp;
+ struct sg_fd *sfp;
+ if (!srp) {
+ WARN_ONCE("%s: srp unexpectedly NULL\n", __func__);
+ return;
+ }
+ sfp = srp->parentfp;
+ if (!sfp) {
+ WARN_ONCE(1, "%s: sfp unexpectedly NULL\n", __func__);
+ return;
+ }
+ SG_LOG(3, sfp, "%s: srp=0x%p\n", __func__, srp);
sg_finish_scsi_blk_rq(srp);
sg_deact_request(sfp, srp);
kref_put(&sfp->f_ref, sg_remove_sfp);
@@ -1637,7 +1676,6 @@ static bool sg_sysfs_valid;
static struct sg_device *
sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
{
- struct request_queue *q = scsidp->request_queue;
struct sg_device *sdp;
unsigned long iflags;
int error;
@@ -1677,7 +1715,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
init_waitqueue_head(&sdp->open_wait);
clear_bit(SG_FDEV_DETACHING, sdp->fdev_bm);
rwlock_init(&sdp->sfd_lock);
- sdp->max_sgat_sz = queue_max_segments(q);
+ sg_calc_sgat_param(sdp);
sdp->index = k;
kref_init(&sdp->d_ref);
error = 0;
@@ -1847,24 +1885,25 @@ init_sg(void)
{
int rc;
- if (scatter_elem_sz < PAGE_SIZE) {
+ if (scatter_elem_sz < (int)PAGE_SIZE)
scatter_elem_sz = PAGE_SIZE;
- scatter_elem_sz_prev = scatter_elem_sz;
- }
+ else if (scatter_elem_sz != (1 << ilog2(scatter_elem_sz)))
+ scatter_elem_sz = 1 << ilog2(scatter_elem_sz);
+ /* scatter_elem_sz rounded down to power of 2, or PAGE_SIZE */
if (def_reserved_size >= 0)
sg_big_buff = def_reserved_size;
else
def_reserved_size = sg_big_buff;
- rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
+ rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
SG_MAX_DEVS, "sg");
if (rc)
return rc;
sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
if ( IS_ERR(sg_sysfs_class) ) {
rc = PTR_ERR(sg_sysfs_class);
- goto err_out;
- }
+ goto err_out_unreg;
+ }
sg_sysfs_valid = true;
rc = scsi_register_interface(&sg_interface);
if (0 == rc) {
@@ -1872,7 +1911,7 @@ init_sg(void)
return 0;
}
class_destroy(sg_sysfs_class);
-err_out:
+err_out_unreg:
unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
return rc;
}
@@ -1977,7 +2016,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
mutex_unlock(&sfp->f_mutex);
return res;
} else {
- res = sg_build_indirect(req_schp, sfp, dxfer_len);
+ res = sg_mk_sgat(req_schp, sfp, dxfer_len);
if (res) {
mutex_unlock(&sfp->f_mutex);
return res;
@@ -2057,117 +2096,100 @@ sg_finish_scsi_blk_rq(struct sg_request *srp)
if (srp->res_used)
sg_unlink_reserve(sfp, srp);
else
- sg_remove_scat(sfp, req_schp);
+ sg_remove_sgat(sfp, req_schp);
}
static int
-sg_build_sgat(struct sg_scatter_hold *schp, const struct sg_fd *sfp,
- int tablesize)
-{
- int sg_buflen = tablesize * sizeof(struct page *);
- gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
-
- schp->pages = kzalloc(sg_buflen, gfp_flags);
- if (!schp->pages)
- return -ENOMEM;
- schp->sglist_len = sg_buflen;
- return tablesize; /* number of scat_gath elements allocated */
-}
-
-static int
-sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
- int buff_size)
-{
- int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
- int max_sgat_sz = sfp->parentdp->max_sgat_sz;
- int blk_size = buff_size, order;
- gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
+sg_mk_sgat(struct sg_scatter_hold *schp, struct sg_fd *sfp, int minlen)
+{
+ int j, k, rem_sz, order, align_sz;
+ int m_size = minlen;
+ int rup_sz = 0;
+ int mx_sgat_elems = sfp->parentdp->max_sgat_elems;
+ u32 elem_sz;
+ const size_t struct_page_sz = sizeof(struct page *);
+ gfp_t mask_ap = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
+ gfp_t mask_kz = GFP_ATOMIC | __GFP_NOWARN;
struct sg_device *sdp = sfp->parentdp;
- if (blk_size < 0)
+ if (unlikely(m_size < 0))
return -EFAULT;
- if (0 == blk_size)
- ++blk_size; /* don't know why */
+ if (unlikely(m_size == 0))
+ ++m_size; /* don't remember why */
/* round request up to next highest SG_DEF_SECTOR_SZ byte boundary */
- blk_size = ALIGN(blk_size, SG_DEF_SECTOR_SZ);
- SG_LOG(4, sfp, "%s: buff_size=%d, blk_size=%d\n", __func__, buff_size,
- blk_size);
-
- /* N.B. ret_sz carried into this block ... */
- mx_sc_elems = sg_build_sgat(schp, sfp, max_sgat_sz);
- if (mx_sc_elems < 0)
- return mx_sc_elems; /* most likely -ENOMEM */
-
- num = scatter_elem_sz;
- if (unlikely(num != scatter_elem_sz_prev)) {
- if (num < PAGE_SIZE) {
- scatter_elem_sz = PAGE_SIZE;
- scatter_elem_sz_prev = PAGE_SIZE;
- } else
- scatter_elem_sz_prev = num;
- }
-
- if (sdp->device->host->unchecked_isa_dma)
- gfp_mask |= GFP_DMA;
-
- order = get_order(num);
-retry:
- ret_sz = 1 << (PAGE_SHIFT + order);
+ align_sz = ALIGN(m_size, SG_DEF_SECTOR_SZ);
- for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
- k++, rem_sz -= ret_sz) {
-
- num = (rem_sz > scatter_elem_sz_prev) ?
- scatter_elem_sz_prev : rem_sz;
+ schp->pages = kcalloc(mx_sgat_elems, struct_page_sz, mask_kz);
+ SG_LOG(4, sfp, "%s: minlen=%d, align_sz=%d [sz=%zu, 0x%p ++]\n",
+ __func__, minlen, align_sz, mx_sgat_elems * struct_page_sz,
+ schp->pages);
+ if (unlikely(!schp->pages))
+ return -ENOMEM;
- schp->pages[k] = alloc_pages(gfp_mask, order);
+ elem_sz = sfp->sgat_elem_sz; /* power of 2 and >= PAGE_SIZE */
+ if (sdp && unlikely(sdp->device->host->unchecked_isa_dma))
+ mask_ap |= GFP_DMA;
+ /* PAGE_SIZE == (1 << PAGE_SHIFT) == (2 ** PAGE_SHIFT) */
+ order = get_order(elem_sz); /* --> ilog2(1+((elem_sz-1)/PAGE_SIZE)) */
+again:
+ rup_sz = 1 << (PAGE_SHIFT + order); /* round up size */
+
+ for (k = 0, rem_sz = align_sz; rem_sz > 0 && k < mx_sgat_elems;
+ ++k, rem_sz -= rup_sz) {
+ schp->pages[k] = alloc_pages(mask_ap, order);
if (!schp->pages[k])
- goto out;
-
- if (num == scatter_elem_sz_prev) {
- if (unlikely(ret_sz > scatter_elem_sz_prev)) {
- scatter_elem_sz = ret_sz;
- scatter_elem_sz_prev = ret_sz;
- }
- }
- SG_LOG(5, sfp, "%s: k=%d, num=%d, ret_sz=%d\n", __func__, k,
- num, ret_sz);
- } /* end of for loop */
-
+ goto err_out;
+ SG_LOG(5, sfp, "%s: k=%d, rup_sz=%d [0x%p ++]\n", __func__, k,
+ rup_sz, schp->pages[k]);
+ }
schp->page_order = order;
schp->num_sgat = k;
SG_LOG(5, sfp, "%s: num_sgat=%d, order=%d\n", __func__, k, order);
- schp->buflen = blk_size;
- if (rem_sz > 0) /* must have failed */
+ if (unlikely(rem_sz > 0)) /* must have failed */
return -ENOMEM;
+ schp->buflen = align_sz;
return 0;
-out:
- for (i = 0; i < k; i++)
- __free_pages(schp->pages[i], order);
+err_out:
+ for (j = 0; j < k; ++j)
+ __free_pages(schp->pages[j], order);
if (--order >= 0)
- goto retry;
-
+ goto again;
+ kfree(schp->pages);
return -ENOMEM;
}
static void
-sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
+sg_remove_sgat_helper(struct sg_fd *sfp, struct sg_scatter_hold *schp)
{
- SG_LOG(4, sfp, "%s: num_sgat=%d\n", __func__, schp->num_sgat);
- if (schp->pages && schp->sglist_len > 0) {
- if (!schp->dio_in_use) {
- int k;
+ int k;
+ void *p;
- for (k = 0; k < schp->num_sgat && schp->pages[k]; k++) {
- SG_LOG(5, sfp, "%s: pg[%d]=0x%p --\n",
- __func__, k, schp->pages[k]);
- __free_pages(schp->pages[k], schp->page_order);
- }
- kfree(schp->pages);
- }
+ if (!schp->pages)
+ return;
+ for (k = 0; k < schp->num_sgat; ++k) {
+ p = schp->pages[k];
+ SG_LOG(5, sfp, "%s: pg[%d]=0x%p --\n", __func__, k, p);
+ if (unlikely(!p))
+ continue;
+ __free_pages(p, schp->page_order);
}
- memset(schp, 0, sizeof (*schp));
+ SG_LOG(5, sfp, "%s: pg_order=%u, free pgs=0x%p --\n", __func__,
+ schp->page_order, schp->pages);
+ kfree(schp->pages);
+}
+
+/* Remove the data (possibly a sgat list) held by srp, not srp itself */
+static void
+sg_remove_sgat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
+{
+ SG_LOG(4, sfp, "%s: num_sgat=%d%s\n", __func__, schp->num_sgat,
+ ((sfp ? (&sfp->reserve == schp) : false) ?
+ " [rsv]" : ""));
+ if (!schp->dio_in_use)
+ sg_remove_sgat_helper(sfp, schp);
+
+ memset(schp, 0, sizeof(*schp)); /* zeros buflen and dlen */
}
/*
@@ -2214,10 +2236,10 @@ sg_build_reserve(struct sg_fd *sfp, int req_size)
do {
if (req_size < PAGE_SIZE)
req_size = PAGE_SIZE;
- if (0 == sg_build_indirect(schp, sfp, req_size))
+ if (sg_mk_sgat(schp, sfp, req_size) == 0)
return;
else
- sg_remove_scat(sfp, schp);
+ sg_remove_sgat(sfp, schp);
req_size >>= 1; /* divide by 2 */
} while (req_size > (PAGE_SIZE / 2));
}
@@ -2321,8 +2343,8 @@ sg_deact_request(struct sg_fd *sfp, struct sg_request *srp)
static struct sg_fd *
sg_add_sfp(struct sg_device *sdp)
{
+ int rbuf_len;
unsigned long iflags;
- int bufflen;
struct sg_fd *sfp;
sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
@@ -2339,6 +2361,14 @@ sg_add_sfp(struct sg_device *sdp)
sfp->force_packid = SG_DEF_FORCE_PACK_ID;
sfp->cmd_q = SG_DEF_COMMAND_Q;
sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
+ /*
+ * SG_SCATTER_SZ initializes scatter_elem_sz but different value may
+ * be given as driver/module parameter (e.g. 'scatter_elem_sz=8192').
+ * Any user provided number will be changed to be PAGE_SIZE as a
+ * minimum, otherwise it will be rounded down (if required) to a
+ * power of 2. So it will always be a power of 2.
+ */
+ sfp->sgat_elem_sz = scatter_elem_sz;
sfp->parentdp = sdp;
atomic_set(&sfp->submitted, 0);
atomic_set(&sfp->waiting, 0);
@@ -2355,14 +2385,13 @@ sg_add_sfp(struct sg_device *sdp)
if (unlikely(sg_big_buff != def_reserved_size))
sg_big_buff = def_reserved_size;
- bufflen = min_t(int, sg_big_buff,
- max_sectors_bytes(sdp->device->request_queue));
- sg_build_reserve(sfp, bufflen);
- SG_LOG(3, sfp, "%s: bufflen=%d, num_sgat=%d\n", __func__,
- sfp->reserve.buflen, sfp->reserve.num_sgat);
+ rbuf_len = min_t(int, sg_big_buff, sdp->max_sgat_sz);
+ if (rbuf_len > 0)
+ sg_build_reserve(sfp, rbuf_len);
kref_get(&sdp->d_ref);
__module_get(THIS_MODULE);
+ SG_LOG(3, sfp, "%s: success, sfp=0x%p ++\n", __func__, sfp);
return sfp;
}
@@ -2393,7 +2422,7 @@ sg_remove_sfp_usercontext(struct work_struct *work)
if (sfp->reserve.buflen > 0) {
SG_LOG(6, sfp, "%s: buflen=%d, num_sgat=%d\n", __func__,
(int)sfp->reserve.buflen, (int)sfp->reserve.num_sgat);
- sg_remove_scat(sfp, &sfp->reserve);
+ sg_remove_sgat(sfp, &sfp->reserve);
}
SG_LOG(6, sfp, "%s: sfp=0x%p\n", __func__, sfp);
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 19/23] sg: rework scatter gather handling
2019-10-08 7:50 ` [PATCH v5 19/23] sg: rework scatter gather handling Douglas Gilbert
@ 2019-10-18 10:22 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:22 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Rename sg_build_indirect() to sg_mk_sgat() and sg_remove_scat()
> to sg_remove_sgat(). Re-implement those functions. Add
> sg_calc_sgat_param() to calculate various scatter gather
> list parameters. Some other minor clean-ups.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 275 +++++++++++++++++++++++++---------------------
> 1 file changed, 152 insertions(+), 123 deletions(-)
>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 20/23] sg: introduce request state machine
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (18 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 19/23] sg: rework scatter gather handling Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:25 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 21/23] sg: sg_find_srp_by_id Douglas Gilbert
` (2 subsequent siblings)
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
The introduced request state machine is not wired in so that
the size of one of the following patches is reduced. Bit
operation defines for the request and file descriptor level
are also introduced. Minor rework og sg_rd_append() function.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 237 ++++++++++++++++++++++++++++++++++------------
1 file changed, 175 insertions(+), 62 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 5b560f720993..4e6f6fb2a54e 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -75,7 +75,43 @@ static char *sg_version_date = "20190606";
#define uptr64(val) ((void __user *)(uintptr_t)(val))
#define cuptr64(val) ((const void __user *)(uintptr_t)(val))
+/* Following enum contains the states of sg_request::rq_st */
+enum sg_rq_state {
+ SG_RS_INACTIVE = 0, /* request not in use (e.g. on fl) */
+ SG_RS_INFLIGHT, /* active: cmd/req issued, no response yet */
+ SG_RS_AWAIT_RD, /* response received, awaiting read */
+ SG_RS_DONE_RD, /* read is ongoing or done */
+ SG_RS_BUSY, /* temporary state should rarely be seen */
+};
+
+#define SG_TIME_UNIT_MS 0 /* milliseconds */
+#define SG_DEF_TIME_UNIT SG_TIME_UNIT_MS
#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
+#define SG_FD_Q_AT_HEAD 0
+#define SG_DEFAULT_Q_AT SG_FD_Q_AT_HEAD /* for backward compatibility */
+#define SG_FL_MMAP_DIRECT (SG_FLAG_MMAP_IO | SG_FLAG_DIRECT_IO)
+
+/* Only take lower 4 bits of driver byte, all host byte and sense byte */
+#define SG_ML_RESULT_MSK 0x0fff00ff /* mid-level's 32 bit result value */
+
+#define SG_PACK_ID_WILDCARD (-1)
+
+#define SG_ADD_RQ_MAX_RETRIES 40 /* to stop infinite _trylock(s) */
+
+/* Bit positions (flags) for sg_request::frq_bm bitmask follow */
+#define SG_FRQ_IS_ORPHAN 1 /* owner of request gone */
+#define SG_FRQ_SYNC_INVOC 2 /* synchronous (blocking) invocation */
+#define SG_FRQ_DIO_IN_USE 3 /* false->indirect_IO,mmap; 1->dio */
+#define SG_FRQ_NO_US_XFER 4 /* no user space transfer of data */
+#define SG_FRQ_DEACT_ORPHAN 7 /* not keeping orphan so de-activate */
+#define SG_FRQ_BLK_PUT_REQ 9 /* set when blk_put_request() called */
+
+/* Bit positions (flags) for sg_fd::ffd_bm bitmask follow */
+#define SG_FFD_FORCE_PACKID 0 /* receive only given pack_id/tag */
+#define SG_FFD_CMD_Q 1 /* clear: only 1 active req per fd */
+#define SG_FFD_KEEP_ORPHAN 2 /* policy for this fd */
+#define SG_FFD_MMAP_CALLED 3 /* mmap(2) system call made on fd */
+#define SG_FFD_Q_AT_TAIL 5 /* set: queue reqs at tail of blk q */
/* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
#define SG_FDEV_EXCLUDE 0 /* have fd open with O_EXCL */
@@ -83,12 +119,11 @@ static char *sg_version_date = "20190606";
#define SG_FDEV_LOG_SENSE 2 /* set by ioctl(SG_SET_DEBUG) */
int sg_big_buff = SG_DEF_RESERVED_SIZE;
-/* N.B. This variable is readable and writeable via
- /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
- of this size (or less if there is not enough memory) will be reserved
- for use by this file descriptor. [Deprecated usage: this variable is also
- readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
- the kernel (i.e. it is not a module).] */
+/*
+ * This variable is accessible via /proc/scsi/sg/def_reserved_size . Each
+ * time sg_open() is called a sg_request of this size (or less if there is
+ * not enough memory) will be reserved for use by this file descriptor.
+ */
static int def_reserved_size = -1; /* picks up init parameter */
static int sg_allow_dio = SG_ALLOW_DIO_DEF;
@@ -132,6 +167,7 @@ struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
char sg_io_owned; /* 1 -> packet belongs to SG_IO */
/* done protected by rq_list_lock */
char done; /* 0->before bh, 1->before read, 2->read */
+ atomic_t rq_st; /* request state, holds a enum sg_rq_state */
struct request *rq; /* released in sg_rq_end_io(), bio kept */
struct bio *bio; /* kept until this req -->SG_RS_INACTIVE */
struct execute_work ew_orph; /* harvest orphan request */
@@ -208,10 +244,15 @@ static void sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
static void sg_remove_sfp(struct kref *);
static struct sg_request *sg_add_request(struct sg_fd *sfp);
-static int sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
+static void sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_device *sg_get_dev(int dev);
static void sg_device_destroy(struct kref *kref);
static void sg_calc_sgat_param(struct sg_device *sdp);
+static const char *sg_rq_st_str(enum sg_rq_state rq_st, bool long_str);
+static void sg_rep_rq_state_fail(struct sg_fd *sfp,
+ enum sg_rq_state exp_old_st,
+ enum sg_rq_state want_st,
+ enum sg_rq_state act_old_st);
#define SZ_SG_HEADER ((int)sizeof(struct sg_header)) /* v1 and v2 header */
#define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
@@ -219,6 +260,8 @@ static void sg_calc_sgat_param(struct sg_device *sdp);
#define SG_IS_DETACHING(sdp) test_bit(SG_FDEV_DETACHING, (sdp)->fdev_bm)
#define SG_HAVE_EXCLUDE(sdp) test_bit(SG_FDEV_EXCLUDE, (sdp)->fdev_bm)
+#define SG_RS_ACTIVE(srp) (atomic_read(&(srp)->rq_st) != SG_RS_INACTIVE)
+#define SG_RS_AWAIT_READ(srp) (atomic_read(&(srp)->rq_st) == SG_RS_AWAIT_RD)
/*
* Kernel needs to be built with CONFIG_SCSI_LOGGING to see log messages.
@@ -382,15 +425,6 @@ sg_open(struct inode *inode, struct file *filp)
res = sg_allow_if_err_recovery(sdp, non_block);
if (res)
goto error_out;
- /* scsi_block_when_processing_errors() may block so bypass
- * check if O_NONBLOCK. Permits SCSI commands to be issued
- * during error recovery. Tread carefully. */
- if (!((op_flags & O_NONBLOCK) ||
- scsi_block_when_processing_errors(sdp->device))) {
- res = -ENXIO;
- /* we are in error recovery for this device */
- goto error_out;
- }
mutex_lock(&sdp->open_rel_lock);
if (op_flags & O_NONBLOCK) {
@@ -494,12 +528,12 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
struct sg_device *sdp;
struct sg_fd *sfp;
struct sg_request *srp;
+ u8 cmnd[SG_MAX_CDB_SIZE];
struct sg_header ov2hdr;
struct sg_io_hdr v3hdr;
struct sg_header *ohp = &ov2hdr;
struct sg_io_hdr *h3p = &v3hdr;
struct sg_comm_wr_t cwr;
- u8 cmnd[SG_MAX_CDB_SIZE];
res = sg_check_file_access(filp, __func__);
if (res)
@@ -748,11 +782,25 @@ sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp)
return 0;
}
+static inline int
+sg_rstate_chg(struct sg_request *srp, enum sg_rq_state old_st,
+ enum sg_rq_state new_st)
+{
+ enum sg_rq_state act_old_st = (enum sg_rq_state)
+ atomic_cmpxchg(&srp->rq_st, old_st, new_st);
+
+ if (act_old_st == old_st)
+ return 0; /* implies new_st --> srp->rq_st */
+ else if (IS_ENABLED(CONFIG_SCSI_LOGGING))
+ sg_rep_rq_state_fail(srp->parentfp, old_st, new_st,
+ act_old_st);
+ return -EPROTOTYPE;
+}
/*
- * read(2) related functions follow. They are shown after write(2) related
- * functions. Apart from read(2) itself, ioctl(SG_IORECEIVE) and the second
- * half of the ioctl(SG_IO) share code with read(2).
+ * This function is called by wait_event_interruptible in sg_read() and
+ * sg_ctl_ioreceive(). wait_event_interruptible will return if this one
+ * returns true (or an event like a signal (e.g. control-C) occurs).
*/
static struct sg_request *
@@ -787,6 +835,32 @@ srp_done(struct sg_fd *sfp, struct sg_request *srp)
return ret;
}
+#if IS_ENABLED(CONFIG_SCSI_LOGGING)
+static void
+sg_rep_rq_state_fail(struct sg_fd *sfp, enum sg_rq_state exp_old_st,
+ enum sg_rq_state want_st, enum sg_rq_state act_old_st)
+{
+ const char *eors = "expected old rq_st: ";
+ const char *aors = "actual old rq_st: ";
+
+ if (IS_ENABLED(CONFIG_SCSI_PROC_FS))
+ SG_LOG(1, sfp, "%s: %s%s, %s%s, wanted rq_st: %s\n", __func__,
+ eors, sg_rq_st_str(exp_old_st, false),
+ aors, sg_rq_st_str(act_old_st, false),
+ sg_rq_st_str(want_st, false));
+ else
+ pr_info("sg: %s: %s%d, %s%d, wanted rq_st: %d\n", __func__,
+ eors, (int)exp_old_st, aors, (int)act_old_st,
+ (int)want_st);
+}
+#else
+static void
+sg_rep_rq_state_fail(struct sg_fd *sfp, enum sg_rq_state exp_old_st,
+ enum sg_rq_state want_st, enum sg_rq_state act_old_st)
+{
+}
+#endif
+
static ssize_t
sg_v3_receive(struct sg_fd *sfp, char __user *buf, struct sg_request *srp)
{
@@ -1198,14 +1272,13 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
}
spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
SG_LOG(3, sfp, "%s: SG_GET_PACK_ID=%d\n", __func__, val);
- put_user(val, ip);
- return 0;
+ return put_user(val, ip);
case SG_GET_NUM_WAITING:
return put_user(atomic_read(&sfp->waiting), ip);
case SG_GET_SG_TABLESIZE:
SG_LOG(3, sfp, "%s: SG_GET_SG_TABLESIZE=%d\n", __func__,
- sdp->max_sgat_sz);
- return put_user(sdp->max_sgat_sz, ip);
+ sdp->max_sgat_elems);
+ return put_user(sdp->max_sgat_elems, ip);
case SG_SET_RESERVED_SIZE:
mutex_lock(&sfp->f_mutex);
result = get_user(val, ip);
@@ -1281,7 +1354,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
case SG_GET_LOW_DMA:
SG_LOG(3, sfp, "%s: SG_GET_LOW_DMA\n", __func__);
return put_user((int)sdev->host->unchecked_isa_dma, ip);
- case SG_NEXT_CMD_LEN:
+ case SG_NEXT_CMD_LEN: /* active only in v2 interface */
SG_LOG(3, sfp, "%s: SG_NEXT_CMD_LEN\n", __func__);
result = get_user(val, ip);
if (result)
@@ -2200,48 +2273,37 @@ sg_remove_sgat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
static int
sg_rd_append(struct sg_request *srp, void __user *outp, int num_xfer)
{
+ int k, num, res;
+ struct page *pgp;
struct sg_scatter_hold *schp = &srp->data;
- int k, num;
SG_LOG(4, srp->parentfp, "%s: num_xfer=%d\n", __func__, num_xfer);
- if (!outp || num_xfer <= 0)
- return 0;
+ if (unlikely(!outp || num_xfer <= 0))
+ return (num_xfer == 0 && outp) ? 0 : -EINVAL;
num = 1 << (PAGE_SHIFT + schp->page_order);
- for (k = 0; k < schp->num_sgat && schp->pages[k]; k++) {
+ for (k = 0, res = 0; k < schp->num_sgat; ++k) {
+ pgp = schp->pages[k];
+ if (unlikely(!pgp)) {
+ res = -ENXIO;
+ break;
+ }
if (num > num_xfer) {
- if (copy_to_user(outp, page_address(schp->pages[k]),
- num_xfer))
- return -EFAULT;
+ if (__copy_to_user(outp, page_address(pgp), num_xfer))
+ res = -EFAULT;
break;
} else {
- if (copy_to_user(outp, page_address(schp->pages[k]),
- num))
- return -EFAULT;
+ if (__copy_to_user(outp, page_address(pgp), num)) {
+ res = -EFAULT;
+ break;
+ }
num_xfer -= num;
if (num_xfer <= 0)
break;
outp += num;
}
}
- return 0;
-}
-
-static void
-sg_build_reserve(struct sg_fd *sfp, int req_size)
-{
- struct sg_scatter_hold *schp = &sfp->reserve;
-
- SG_LOG(3, sfp, "%s: buflen=%d\n", __func__, req_size);
- do {
- if (req_size < PAGE_SIZE)
- req_size = PAGE_SIZE;
- if (sg_mk_sgat(schp, sfp, req_size) == 0)
- return;
- else
- sg_remove_sgat(sfp, schp);
- req_size >>= 1; /* divide by 2 */
- } while (req_size > (PAGE_SIZE / 2));
+ return res;
}
static void
@@ -2290,6 +2352,22 @@ sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp)
sfp->res_in_use = 0;
}
+static void
+sg_build_reserve(struct sg_fd *sfp, int req_size)
+{
+ struct sg_scatter_hold *schp = &sfp->reserve;
+
+ SG_LOG(3, sfp, "%s: buflen=%d\n", __func__, req_size);
+ do {
+ if (req_size < PAGE_SIZE)
+ req_size = PAGE_SIZE;
+ if (sg_mk_sgat(schp, sfp, req_size) == 0)
+ return;
+ sg_remove_sgat(sfp, schp);
+ req_size >>= 1; /* divide by 2 */
+ } while (req_size > (PAGE_SIZE / 2));
+}
+
/* always adds to end of list */
static struct sg_request *
sg_add_request(struct sg_fd *sfp)
@@ -2321,23 +2399,21 @@ sg_add_request(struct sg_fd *sfp)
return NULL;
}
-/* Return of 1 for found; 0 for not found */
-static int
+static void
sg_deact_request(struct sg_fd *sfp, struct sg_request *srp)
{
unsigned long iflags;
- int res = 0;
- if (!sfp || !srp || list_empty(&sfp->rq_list))
- return res;
+ if (WARN_ON(!sfp || !srp))
+ return;
+ if (list_empty(&sfp->rq_list))
+ return;
spin_lock_irqsave(&sfp->rq_list_lock, iflags);
if (!list_empty(&srp->entry)) {
list_del(&srp->entry);
srp->parentfp = NULL;
- res = 1;
}
spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return res;
}
static struct sg_fd *
@@ -2395,6 +2471,15 @@ sg_add_sfp(struct sg_device *sdp)
return sfp;
}
+/*
+ * A successful call to sg_release() will result, at some later time, to this
+ * function being invoked. All requests associated with this file descriptor
+ * should be completed or cancelled when this function is called (due to
+ * sfp->f_ref). Also the file descriptor itself has not been accessible since
+ * it was list_del()-ed by the preceding sg_remove_sfp() call. So no locking
+ * is required. sdp should never be NULL but to make debugging more robust,
+ * this function will not blow up in that case.
+ */
static void
sg_remove_sfp_usercontext(struct work_struct *work)
{
@@ -2490,6 +2575,33 @@ sg_get_dev(int dev)
return sdp;
}
+#if IS_ENABLED(CONFIG_SCSI_PROC_FS)
+static const char *
+sg_rq_st_str(enum sg_rq_state rq_st, bool long_str)
+{
+ switch (rq_st) { /* request state */
+ case SG_RS_INACTIVE:
+ return long_str ? "inactive" : "ina";
+ case SG_RS_INFLIGHT:
+ return long_str ? "inflight" : "act";
+ case SG_RS_AWAIT_RD:
+ return long_str ? "await_read" : "rcv";
+ case SG_RS_DONE_RD:
+ return long_str ? "done_read" : "fin";
+ case SG_RS_BUSY:
+ return long_str ? "busy" : "bsy";
+ default:
+ return long_str ? "unknown" : "unk";
+ }
+}
+#else
+static const char *
+sg_rq_st_str(enum sg_rq_state rq_st, bool long_str)
+{
+ return "";
+}
+#endif
+
#if IS_ENABLED(CONFIG_SCSI_PROC_FS) /* long, almost to end of file */
static int sg_proc_seq_show_int(struct seq_file *s, void *v);
@@ -2788,8 +2900,9 @@ sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
jiffies_to_msecs(fp->timeout)),
(ms > hp->duration ? ms - hp->duration : 0));
}
- seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
- (int) srp->data.cmd_opcode);
+ seq_printf(s, "ms sgat=%d op=0x%02x dummy: %s\n", usg,
+ (int)srp->data.cmd_opcode,
+ sg_rq_st_str(SG_RS_INACTIVE, false));
}
if (list_empty(&fp->rq_list))
seq_puts(s, " No requests active\n");
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 20/23] sg: introduce request state machine
2019-10-08 7:50 ` [PATCH v5 20/23] sg: introduce request state machine Douglas Gilbert
@ 2019-10-18 10:25 ` Hannes Reinecke
2019-10-24 4:24 ` Douglas Gilbert
0 siblings, 1 reply; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:25 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> The introduced request state machine is not wired in so that
> the size of one of the following patches is reduced. Bit
> operation defines for the request and file descriptor level
> are also introduced. Minor rework og sg_rd_append() function.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 237 ++++++++++++++++++++++++++++++++++------------
> 1 file changed, 175 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 5b560f720993..4e6f6fb2a54e 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -75,7 +75,43 @@ static char *sg_version_date = "20190606";
> #define uptr64(val) ((void __user *)(uintptr_t)(val))
> #define cuptr64(val) ((const void __user *)(uintptr_t)(val))
>
> +/* Following enum contains the states of sg_request::rq_st */
> +enum sg_rq_state {
> + SG_RS_INACTIVE = 0, /* request not in use (e.g. on fl) */
> + SG_RS_INFLIGHT, /* active: cmd/req issued, no response yet */
> + SG_RS_AWAIT_RD, /* response received, awaiting read */
> + SG_RS_DONE_RD, /* read is ongoing or done */
> + SG_RS_BUSY, /* temporary state should rarely be seen */
> +};
> +
> +#define SG_TIME_UNIT_MS 0 /* milliseconds */
> +#define SG_DEF_TIME_UNIT SG_TIME_UNIT_MS
> #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
> +#define SG_FD_Q_AT_HEAD 0
> +#define SG_DEFAULT_Q_AT SG_FD_Q_AT_HEAD /* for backward compatibility */
> +#define SG_FL_MMAP_DIRECT (SG_FLAG_MMAP_IO | SG_FLAG_DIRECT_IO)
> +
> +/* Only take lower 4 bits of driver byte, all host byte and sense byte */
> +#define SG_ML_RESULT_MSK 0x0fff00ff /* mid-level's 32 bit result value */
> +
> +#define SG_PACK_ID_WILDCARD (-1)
> +
> +#define SG_ADD_RQ_MAX_RETRIES 40 /* to stop infinite _trylock(s) */
> +
> +/* Bit positions (flags) for sg_request::frq_bm bitmask follow */
> +#define SG_FRQ_IS_ORPHAN 1 /* owner of request gone */
> +#define SG_FRQ_SYNC_INVOC 2 /* synchronous (blocking) invocation */
> +#define SG_FRQ_DIO_IN_USE 3 /* false->indirect_IO,mmap; 1->dio */
> +#define SG_FRQ_NO_US_XFER 4 /* no user space transfer of data */
> +#define SG_FRQ_DEACT_ORPHAN 7 /* not keeping orphan so de-activate */
> +#define SG_FRQ_BLK_PUT_REQ 9 /* set when blk_put_request() called */
> +
> +/* Bit positions (flags) for sg_fd::ffd_bm bitmask follow */
> +#define SG_FFD_FORCE_PACKID 0 /* receive only given pack_id/tag */
> +#define SG_FFD_CMD_Q 1 /* clear: only 1 active req per fd */
> +#define SG_FFD_KEEP_ORPHAN 2 /* policy for this fd */
> +#define SG_FFD_MMAP_CALLED 3 /* mmap(2) system call made on fd */
> +#define SG_FFD_Q_AT_TAIL 5 /* set: queue reqs at tail of blk q */
>
> /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
> #define SG_FDEV_EXCLUDE 0 /* have fd open with O_EXCL */
> @@ -83,12 +119,11 @@ static char *sg_version_date = "20190606";
> #define SG_FDEV_LOG_SENSE 2 /* set by ioctl(SG_SET_DEBUG) */
>
> int sg_big_buff = SG_DEF_RESERVED_SIZE;
> -/* N.B. This variable is readable and writeable via
> - /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
> - of this size (or less if there is not enough memory) will be reserved
> - for use by this file descriptor. [Deprecated usage: this variable is also
> - readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
> - the kernel (i.e. it is not a module).] */
> +/*
> + * This variable is accessible via /proc/scsi/sg/def_reserved_size . Each
> + * time sg_open() is called a sg_request of this size (or less if there is
> + * not enough memory) will be reserved for use by this file descriptor.
> + */
> static int def_reserved_size = -1; /* picks up init parameter */
> static int sg_allow_dio = SG_ALLOW_DIO_DEF;
>
> @@ -132,6 +167,7 @@ struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
> char sg_io_owned; /* 1 -> packet belongs to SG_IO */
> /* done protected by rq_list_lock */
> char done; /* 0->before bh, 1->before read, 2->read */
> + atomic_t rq_st; /* request state, holds a enum sg_rq_state */
> struct request *rq; /* released in sg_rq_end_io(), bio kept */
> struct bio *bio; /* kept until this req -->SG_RS_INACTIVE */
> struct execute_work ew_orph; /* harvest orphan request */
> @@ -208,10 +244,15 @@ static void sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp);
> static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
> static void sg_remove_sfp(struct kref *);
> static struct sg_request *sg_add_request(struct sg_fd *sfp);
> -static int sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
> +static void sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
> static struct sg_device *sg_get_dev(int dev);
> static void sg_device_destroy(struct kref *kref);
> static void sg_calc_sgat_param(struct sg_device *sdp);
> +static const char *sg_rq_st_str(enum sg_rq_state rq_st, bool long_str);
> +static void sg_rep_rq_state_fail(struct sg_fd *sfp,
> + enum sg_rq_state exp_old_st,
> + enum sg_rq_state want_st,
> + enum sg_rq_state act_old_st);
>
> #define SZ_SG_HEADER ((int)sizeof(struct sg_header)) /* v1 and v2 header */
> #define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
> @@ -219,6 +260,8 @@ static void sg_calc_sgat_param(struct sg_device *sdp);
>
> #define SG_IS_DETACHING(sdp) test_bit(SG_FDEV_DETACHING, (sdp)->fdev_bm)
> #define SG_HAVE_EXCLUDE(sdp) test_bit(SG_FDEV_EXCLUDE, (sdp)->fdev_bm)
> +#define SG_RS_ACTIVE(srp) (atomic_read(&(srp)->rq_st) != SG_RS_INACTIVE)
> +#define SG_RS_AWAIT_READ(srp) (atomic_read(&(srp)->rq_st) == SG_RS_AWAIT_RD)
>
> /*
> * Kernel needs to be built with CONFIG_SCSI_LOGGING to see log messages.
> @@ -382,15 +425,6 @@ sg_open(struct inode *inode, struct file *filp)
> res = sg_allow_if_err_recovery(sdp, non_block);
> if (res)
> goto error_out;
> - /* scsi_block_when_processing_errors() may block so bypass
> - * check if O_NONBLOCK. Permits SCSI commands to be issued
> - * during error recovery. Tread carefully. */
> - if (!((op_flags & O_NONBLOCK) ||
> - scsi_block_when_processing_errors(sdp->device))) {
> - res = -ENXIO;
> - /* we are in error recovery for this device */
> - goto error_out;
> - }
>
> mutex_lock(&sdp->open_rel_lock);
> if (op_flags & O_NONBLOCK) {
> @@ -494,12 +528,12 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
> struct sg_device *sdp;
> struct sg_fd *sfp;
> struct sg_request *srp;
> + u8 cmnd[SG_MAX_CDB_SIZE];
> struct sg_header ov2hdr;
> struct sg_io_hdr v3hdr;
> struct sg_header *ohp = &ov2hdr;
> struct sg_io_hdr *h3p = &v3hdr;
> struct sg_comm_wr_t cwr;
> - u8 cmnd[SG_MAX_CDB_SIZE];
>
> res = sg_check_file_access(filp, __func__);
> if (res)
> @@ -748,11 +782,25 @@ sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp)
> return 0;
> }
>
> +static inline int
> +sg_rstate_chg(struct sg_request *srp, enum sg_rq_state old_st,
> + enum sg_rq_state new_st)
> +{
> + enum sg_rq_state act_old_st = (enum sg_rq_state)
> + atomic_cmpxchg(&srp->rq_st, old_st, new_st);
> +
> + if (act_old_st == old_st)
> + return 0; /* implies new_st --> srp->rq_st */
> + else if (IS_ENABLED(CONFIG_SCSI_LOGGING))
> + sg_rep_rq_state_fail(srp->parentfp, old_st, new_st,
> + act_old_st);
> + return -EPROTOTYPE;
> +}
>
-EPROTOTYPE?
Now there someone has read POSIX ... why not simply -EINVAL as one would
expect?
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread* Re: [PATCH v5 20/23] sg: introduce request state machine
2019-10-18 10:25 ` Hannes Reinecke
@ 2019-10-24 4:24 ` Douglas Gilbert
2019-10-24 5:51 ` Hannes Reinecke
0 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-24 4:24 UTC (permalink / raw)
To: Hannes Reinecke, linux-scsi; +Cc: martin.petersen, jejb
On 2019-10-18 6:25 a.m., Hannes Reinecke wrote:
> On 10/8/19 9:50 AM, Douglas Gilbert wrote:
>> The introduced request state machine is not wired in so that
>> the size of one of the following patches is reduced. Bit
>> operation defines for the request and file descriptor level
>> are also introduced. Minor rework og sg_rd_append() function.
>>
>> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
>> ---
>> drivers/scsi/sg.c | 237 ++++++++++++++++++++++++++++++++++------------
>> 1 file changed, 175 insertions(+), 62 deletions(-)
>>
>> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
>> index 5b560f720993..4e6f6fb2a54e 100644
>> --- a/drivers/scsi/sg.c
>> +++ b/drivers/scsi/sg.c
>> @@ -75,7 +75,43 @@ static char *sg_version_date = "20190606";
>> #define uptr64(val) ((void __user *)(uintptr_t)(val))
>> #define cuptr64(val) ((const void __user *)(uintptr_t)(val))
>>
>> +/* Following enum contains the states of sg_request::rq_st */
>> +enum sg_rq_state {
>> + SG_RS_INACTIVE = 0, /* request not in use (e.g. on fl) */
>> + SG_RS_INFLIGHT, /* active: cmd/req issued, no response yet */
>> + SG_RS_AWAIT_RD, /* response received, awaiting read */
>> + SG_RS_DONE_RD, /* read is ongoing or done */
>> + SG_RS_BUSY, /* temporary state should rarely be seen */
>> +};
>> +
>> +#define SG_TIME_UNIT_MS 0 /* milliseconds */
>> +#define SG_DEF_TIME_UNIT SG_TIME_UNIT_MS
>> #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
>> +#define SG_FD_Q_AT_HEAD 0
>> +#define SG_DEFAULT_Q_AT SG_FD_Q_AT_HEAD /* for backward compatibility */
>> +#define SG_FL_MMAP_DIRECT (SG_FLAG_MMAP_IO | SG_FLAG_DIRECT_IO)
>> +
>> +/* Only take lower 4 bits of driver byte, all host byte and sense byte */
>> +#define SG_ML_RESULT_MSK 0x0fff00ff /* mid-level's 32 bit result value */
>> +
>> +#define SG_PACK_ID_WILDCARD (-1)
>> +
>> +#define SG_ADD_RQ_MAX_RETRIES 40 /* to stop infinite _trylock(s) */
>> +
>> +/* Bit positions (flags) for sg_request::frq_bm bitmask follow */
>> +#define SG_FRQ_IS_ORPHAN 1 /* owner of request gone */
>> +#define SG_FRQ_SYNC_INVOC 2 /* synchronous (blocking) invocation */
>> +#define SG_FRQ_DIO_IN_USE 3 /* false->indirect_IO,mmap; 1->dio */
>> +#define SG_FRQ_NO_US_XFER 4 /* no user space transfer of data */
>> +#define SG_FRQ_DEACT_ORPHAN 7 /* not keeping orphan so de-activate */
>> +#define SG_FRQ_BLK_PUT_REQ 9 /* set when blk_put_request() called */
>> +
>> +/* Bit positions (flags) for sg_fd::ffd_bm bitmask follow */
>> +#define SG_FFD_FORCE_PACKID 0 /* receive only given pack_id/tag */
>> +#define SG_FFD_CMD_Q 1 /* clear: only 1 active req per fd */
>> +#define SG_FFD_KEEP_ORPHAN 2 /* policy for this fd */
>> +#define SG_FFD_MMAP_CALLED 3 /* mmap(2) system call made on fd */
>> +#define SG_FFD_Q_AT_TAIL 5 /* set: queue reqs at tail of blk q */
>>
>> /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
>> #define SG_FDEV_EXCLUDE 0 /* have fd open with O_EXCL */
>> @@ -83,12 +119,11 @@ static char *sg_version_date = "20190606";
>> #define SG_FDEV_LOG_SENSE 2 /* set by ioctl(SG_SET_DEBUG) */
>>
>> int sg_big_buff = SG_DEF_RESERVED_SIZE;
>> -/* N.B. This variable is readable and writeable via
>> - /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
>> - of this size (or less if there is not enough memory) will be reserved
>> - for use by this file descriptor. [Deprecated usage: this variable is also
>> - readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
>> - the kernel (i.e. it is not a module).] */
>> +/*
>> + * This variable is accessible via /proc/scsi/sg/def_reserved_size . Each
>> + * time sg_open() is called a sg_request of this size (or less if there is
>> + * not enough memory) will be reserved for use by this file descriptor.
>> + */
>> static int def_reserved_size = -1; /* picks up init parameter */
>> static int sg_allow_dio = SG_ALLOW_DIO_DEF;
>>
>> @@ -132,6 +167,7 @@ struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
>> char sg_io_owned; /* 1 -> packet belongs to SG_IO */
>> /* done protected by rq_list_lock */
>> char done; /* 0->before bh, 1->before read, 2->read */
>> + atomic_t rq_st; /* request state, holds a enum sg_rq_state */
>> struct request *rq; /* released in sg_rq_end_io(), bio kept */
>> struct bio *bio; /* kept until this req -->SG_RS_INACTIVE */
>> struct execute_work ew_orph; /* harvest orphan request */
>> @@ -208,10 +244,15 @@ static void sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp);
>> static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
>> static void sg_remove_sfp(struct kref *);
>> static struct sg_request *sg_add_request(struct sg_fd *sfp);
>> -static int sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
>> +static void sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
>> static struct sg_device *sg_get_dev(int dev);
>> static void sg_device_destroy(struct kref *kref);
>> static void sg_calc_sgat_param(struct sg_device *sdp);
>> +static const char *sg_rq_st_str(enum sg_rq_state rq_st, bool long_str);
>> +static void sg_rep_rq_state_fail(struct sg_fd *sfp,
>> + enum sg_rq_state exp_old_st,
>> + enum sg_rq_state want_st,
>> + enum sg_rq_state act_old_st);
>>
>> #define SZ_SG_HEADER ((int)sizeof(struct sg_header)) /* v1 and v2 header */
>> #define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
>> @@ -219,6 +260,8 @@ static void sg_calc_sgat_param(struct sg_device *sdp);
>>
>> #define SG_IS_DETACHING(sdp) test_bit(SG_FDEV_DETACHING, (sdp)->fdev_bm)
>> #define SG_HAVE_EXCLUDE(sdp) test_bit(SG_FDEV_EXCLUDE, (sdp)->fdev_bm)
>> +#define SG_RS_ACTIVE(srp) (atomic_read(&(srp)->rq_st) != SG_RS_INACTIVE)
>> +#define SG_RS_AWAIT_READ(srp) (atomic_read(&(srp)->rq_st) == SG_RS_AWAIT_RD)
>>
>> /*
>> * Kernel needs to be built with CONFIG_SCSI_LOGGING to see log messages.
>> @@ -382,15 +425,6 @@ sg_open(struct inode *inode, struct file *filp)
>> res = sg_allow_if_err_recovery(sdp, non_block);
>> if (res)
>> goto error_out;
>> - /* scsi_block_when_processing_errors() may block so bypass
>> - * check if O_NONBLOCK. Permits SCSI commands to be issued
>> - * during error recovery. Tread carefully. */
>> - if (!((op_flags & O_NONBLOCK) ||
>> - scsi_block_when_processing_errors(sdp->device))) {
>> - res = -ENXIO;
>> - /* we are in error recovery for this device */
>> - goto error_out;
>> - }
>>
>> mutex_lock(&sdp->open_rel_lock);
>> if (op_flags & O_NONBLOCK) {
>> @@ -494,12 +528,12 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
>> struct sg_device *sdp;
>> struct sg_fd *sfp;
>> struct sg_request *srp;
>> + u8 cmnd[SG_MAX_CDB_SIZE];
>> struct sg_header ov2hdr;
>> struct sg_io_hdr v3hdr;
>> struct sg_header *ohp = &ov2hdr;
>> struct sg_io_hdr *h3p = &v3hdr;
>> struct sg_comm_wr_t cwr;
>> - u8 cmnd[SG_MAX_CDB_SIZE];
>>
>> res = sg_check_file_access(filp, __func__);
>> if (res)
>> @@ -748,11 +782,25 @@ sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp)
>> return 0;
>> }
>>
>> +static inline int
>> +sg_rstate_chg(struct sg_request *srp, enum sg_rq_state old_st,
>> + enum sg_rq_state new_st)
>> +{
>> + enum sg_rq_state act_old_st = (enum sg_rq_state)
>> + atomic_cmpxchg(&srp->rq_st, old_st, new_st);
>> +
>> + if (act_old_st == old_st)
>> + return 0; /* implies new_st --> srp->rq_st */
>> + else if (IS_ENABLED(CONFIG_SCSI_LOGGING))
>> + sg_rep_rq_state_fail(srp->parentfp, old_st, new_st,
>> + act_old_st);
>> + return -EPROTOTYPE;
>> +}
>>
> -EPROTOTYPE?
> Now there someone has read POSIX ... why not simply -EINVAL as one would
> expect?
I expect EINVAL from very shallow errors, like sanity checks by
ioctl(SG_IOSUBMIT) or write(2) before they issue a command/request to the
lower levels.
This however is a lot more interesting. It is potentially two readers in
a race, and if the race is close, the loser gets this error. Depending on
the context, the user will either see this error, or EBUSY. There is an
inherent race in the read/receive side of all AIO designs, as far as I
can determine. Such a race is advised against in my documentation, but
if a user, accidentally or otherwise, generates that race, then IMO
the driver needs to handle it. By "handle it" I don't mean trying to help
such users, I mean to protect the driver and the kernel behind it.
A later patch (46/62 currently) adds a 28 entry table of errno values
with their meaning if returned by this driver:
....
EPROTOTYPE atomic state change failed unexpectedly
....
Doug Gilbert
^ permalink raw reply [flat|nested] 43+ messages in thread* Re: [PATCH v5 20/23] sg: introduce request state machine
2019-10-24 4:24 ` Douglas Gilbert
@ 2019-10-24 5:51 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-24 5:51 UTC (permalink / raw)
To: dgilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/24/19 6:24 AM, Douglas Gilbert wrote:
> On 2019-10-18 6:25 a.m., Hannes Reinecke wrote:
>> On 10/8/19 9:50 AM, Douglas Gilbert wrote:
>>> The introduced request state machine is not wired in so that
>>> the size of one of the following patches is reduced. Bit
>>> operation defines for the request and file descriptor level
>>> are also introduced. Minor rework og sg_rd_append() function.
>>>
>>> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
>>> ---
>>> drivers/scsi/sg.c | 237 ++++++++++++++++++++++++++++++++++------------
>>> 1 file changed, 175 insertions(+), 62 deletions(-)
>>>
>>> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
>>> index 5b560f720993..4e6f6fb2a54e 100644
>>> --- a/drivers/scsi/sg.c
>>> +++ b/drivers/scsi/sg.c
>>> @@ -75,7 +75,43 @@ static char *sg_version_date = "20190606";
>>> #define uptr64(val) ((void __user *)(uintptr_t)(val))
>>> #define cuptr64(val) ((const void __user *)(uintptr_t)(val))
>>> +/* Following enum contains the states of sg_request::rq_st */
>>> +enum sg_rq_state {
>>> + SG_RS_INACTIVE = 0, /* request not in use (e.g. on fl) */
>>> + SG_RS_INFLIGHT, /* active: cmd/req issued, no response
>>> yet */
>>> + SG_RS_AWAIT_RD, /* response received, awaiting read */
>>> + SG_RS_DONE_RD, /* read is ongoing or done */
>>> + SG_RS_BUSY, /* temporary state should rarely be seen */
>>> +};
>>> +
>>> +#define SG_TIME_UNIT_MS 0 /* milliseconds */
>>> +#define SG_DEF_TIME_UNIT SG_TIME_UNIT_MS
>>> #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ,
>>> USER_HZ)
>>> +#define SG_FD_Q_AT_HEAD 0
>>> +#define SG_DEFAULT_Q_AT SG_FD_Q_AT_HEAD /* for backward
>>> compatibility */
>>> +#define SG_FL_MMAP_DIRECT (SG_FLAG_MMAP_IO | SG_FLAG_DIRECT_IO)
>>> +
>>> +/* Only take lower 4 bits of driver byte, all host byte and sense
>>> byte */
>>> +#define SG_ML_RESULT_MSK 0x0fff00ff /* mid-level's 32 bit result
>>> value */
>>> +
>>> +#define SG_PACK_ID_WILDCARD (-1)
>>> +
>>> +#define SG_ADD_RQ_MAX_RETRIES 40 /* to stop infinite _trylock(s) */
>>> +
>>> +/* Bit positions (flags) for sg_request::frq_bm bitmask follow */
>>> +#define SG_FRQ_IS_ORPHAN 1 /* owner of request gone */
>>> +#define SG_FRQ_SYNC_INVOC 2 /* synchronous (blocking)
>>> invocation */
>>> +#define SG_FRQ_DIO_IN_USE 3 /* false->indirect_IO,mmap; 1->dio */
>>> +#define SG_FRQ_NO_US_XFER 4 /* no user space transfer of data */
>>> +#define SG_FRQ_DEACT_ORPHAN 7 /* not keeping orphan so
>>> de-activate */
>>> +#define SG_FRQ_BLK_PUT_REQ 9 /* set when blk_put_request()
>>> called */
>>> +
>>> +/* Bit positions (flags) for sg_fd::ffd_bm bitmask follow */
>>> +#define SG_FFD_FORCE_PACKID 0 /* receive only given
>>> pack_id/tag */
>>> +#define SG_FFD_CMD_Q 1 /* clear: only 1 active req per fd */
>>> +#define SG_FFD_KEEP_ORPHAN 2 /* policy for this fd */
>>> +#define SG_FFD_MMAP_CALLED 3 /* mmap(2) system call made on fd */
>>> +#define SG_FFD_Q_AT_TAIL 5 /* set: queue reqs at tail of blk q */
>>> /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
>>> #define SG_FDEV_EXCLUDE 0 /* have fd open with O_EXCL */
>>> @@ -83,12 +119,11 @@ static char *sg_version_date = "20190606";
>>> #define SG_FDEV_LOG_SENSE 2 /* set by ioctl(SG_SET_DEBUG) */
>>> int sg_big_buff = SG_DEF_RESERVED_SIZE;
>>> -/* N.B. This variable is readable and writeable via
>>> - /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a
>>> buffer
>>> - of this size (or less if there is not enough memory) will be
>>> reserved
>>> - for use by this file descriptor. [Deprecated usage: this variable
>>> is also
>>> - readable via /proc/sys/kernel/sg-big-buff if the sg driver is
>>> built into
>>> - the kernel (i.e. it is not a module).] */
>>> +/*
>>> + * This variable is accessible via /proc/scsi/sg/def_reserved_size .
>>> Each
>>> + * time sg_open() is called a sg_request of this size (or less if
>>> there is
>>> + * not enough memory) will be reserved for use by this file descriptor.
>>> + */
>>> static int def_reserved_size = -1; /* picks up init parameter */
>>> static int sg_allow_dio = SG_ALLOW_DIO_DEF;
>>> @@ -132,6 +167,7 @@ struct sg_request { /* SG_MAX_QUEUE requests
>>> outstanding per file */
>>> char sg_io_owned; /* 1 -> packet belongs to SG_IO */
>>> /* done protected by rq_list_lock */
>>> char done; /* 0->before bh, 1->before read, 2->read */
>>> + atomic_t rq_st; /* request state, holds a enum
>>> sg_rq_state */
>>> struct request *rq; /* released in sg_rq_end_io(), bio kept */
>>> struct bio *bio; /* kept until this req -->SG_RS_INACTIVE */
>>> struct execute_work ew_orph; /* harvest orphan request */
>>> @@ -208,10 +244,15 @@ static void sg_unlink_reserve(struct sg_fd
>>> *sfp, struct sg_request *srp);
>>> static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
>>> static void sg_remove_sfp(struct kref *);
>>> static struct sg_request *sg_add_request(struct sg_fd *sfp);
>>> -static int sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
>>> +static void sg_deact_request(struct sg_fd *sfp, struct sg_request
>>> *srp);
>>> static struct sg_device *sg_get_dev(int dev);
>>> static void sg_device_destroy(struct kref *kref);
>>> static void sg_calc_sgat_param(struct sg_device *sdp);
>>> +static const char *sg_rq_st_str(enum sg_rq_state rq_st, bool long_str);
>>> +static void sg_rep_rq_state_fail(struct sg_fd *sfp,
>>> + enum sg_rq_state exp_old_st,
>>> + enum sg_rq_state want_st,
>>> + enum sg_rq_state act_old_st);
>>> #define SZ_SG_HEADER ((int)sizeof(struct sg_header)) /* v1 and
>>> v2 header */
>>> #define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3
>>> header */
>>> @@ -219,6 +260,8 @@ static void sg_calc_sgat_param(struct sg_device
>>> *sdp);
>>> #define SG_IS_DETACHING(sdp) test_bit(SG_FDEV_DETACHING,
>>> (sdp)->fdev_bm)
>>> #define SG_HAVE_EXCLUDE(sdp) test_bit(SG_FDEV_EXCLUDE, (sdp)->fdev_bm)
>>> +#define SG_RS_ACTIVE(srp) (atomic_read(&(srp)->rq_st) !=
>>> SG_RS_INACTIVE)
>>> +#define SG_RS_AWAIT_READ(srp) (atomic_read(&(srp)->rq_st) ==
>>> SG_RS_AWAIT_RD)
>>> /*
>>> * Kernel needs to be built with CONFIG_SCSI_LOGGING to see log
>>> messages.
>>> @@ -382,15 +425,6 @@ sg_open(struct inode *inode, struct file *filp)
>>> res = sg_allow_if_err_recovery(sdp, non_block);
>>> if (res)
>>> goto error_out;
>>> - /* scsi_block_when_processing_errors() may block so bypass
>>> - * check if O_NONBLOCK. Permits SCSI commands to be issued
>>> - * during error recovery. Tread carefully. */
>>> - if (!((op_flags & O_NONBLOCK) ||
>>> - scsi_block_when_processing_errors(sdp->device))) {
>>> - res = -ENXIO;
>>> - /* we are in error recovery for this device */
>>> - goto error_out;
>>> - }
>>> mutex_lock(&sdp->open_rel_lock);
>>> if (op_flags & O_NONBLOCK) {
>>> @@ -494,12 +528,12 @@ sg_write(struct file *filp, const char __user
>>> *p, size_t count, loff_t *ppos)
>>> struct sg_device *sdp;
>>> struct sg_fd *sfp;
>>> struct sg_request *srp;
>>> + u8 cmnd[SG_MAX_CDB_SIZE];
>>> struct sg_header ov2hdr;
>>> struct sg_io_hdr v3hdr;
>>> struct sg_header *ohp = &ov2hdr;
>>> struct sg_io_hdr *h3p = &v3hdr;
>>> struct sg_comm_wr_t cwr;
>>> - u8 cmnd[SG_MAX_CDB_SIZE];
>>> res = sg_check_file_access(filp, __func__);
>>> if (res)
>>> @@ -748,11 +782,25 @@ sg_common_write(struct sg_fd *sfp, struct
>>> sg_comm_wr_t *cwrp)
>>> return 0;
>>> }
>>> +static inline int
>>> +sg_rstate_chg(struct sg_request *srp, enum sg_rq_state old_st,
>>> + enum sg_rq_state new_st)
>>> +{
>>> + enum sg_rq_state act_old_st = (enum sg_rq_state)
>>> + atomic_cmpxchg(&srp->rq_st, old_st, new_st);
>>> +
>>> + if (act_old_st == old_st)
>>> + return 0; /* implies new_st --> srp->rq_st */
>>> + else if (IS_ENABLED(CONFIG_SCSI_LOGGING))
>>> + sg_rep_rq_state_fail(srp->parentfp, old_st, new_st,
>>> + act_old_st);
>>> + return -EPROTOTYPE;
>>> +}
>>>
>> -EPROTOTYPE?
>> Now there someone has read POSIX ... why not simply -EINVAL as one would
>> expect?
>
> I expect EINVAL from very shallow errors, like sanity checks by
> ioctl(SG_IOSUBMIT) or write(2) before they issue a command/request to the
> lower levels.
>
> This however is a lot more interesting. It is potentially two readers in
> a race, and if the race is close, the loser gets this error. Depending on
> the context, the user will either see this error, or EBUSY. There is an
> inherent race in the read/receive side of all AIO designs, as far as I
> can determine. Such a race is advised against in my documentation, but
> if a user, accidentally or otherwise, generates that race, then IMO
> the driver needs to handle it. By "handle it" I don't mean trying to help
> such users, I mean to protect the driver and the kernel behind it.
>
> A later patch (46/62 currently) adds a 28 entry table of errno values
> with their meaning if returned by this driver:
> ....
> EPROTOTYPE atomic state change failed unexpectedly
> ....
>
Ah, right. Fine.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 21/23] sg: sg_find_srp_by_id
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (19 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 20/23] sg: introduce request state machine Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:27 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 22/23] sg: sg_fill_request_element Douglas Gilbert
2019-10-08 7:50 ` [PATCH v5 23/23] sg: printk change %p to %pK Douglas Gilbert
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Replace sg_get_rq_mark() with sg_find_srp_by_id() and
sg_get_ready_srp(). Add sg_chk_mmap() to check flags and
reserve buffer available for mmap() based requests. Add
sg_copy_sense() and sg_rec_v3_state() which is just
refactoring. Add sg_calc_rq_dur() and sg_get_dur() in
preparation for optional nanosecond duration timing.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 293 +++++++++++++++++++++++++++++++---------------
1 file changed, 200 insertions(+), 93 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 4e6f6fb2a54e..7f3a4b937a5a 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -158,16 +158,20 @@ struct sg_fd;
struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
struct list_head entry; /* list entry */
- struct sg_fd *parentfp; /* NULL -> not in use */
struct sg_scatter_hold data; /* hold buffer, perhaps scatter list */
struct sg_io_hdr header; /* scsi command+info, see <scsi/sg.h> */
u8 sense_b[SCSI_SENSE_BUFFERSIZE];
+ u32 duration; /* cmd duration in milliseconds */
char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
char orphan; /* 1 -> drop on sight, 0 -> normal */
char sg_io_owned; /* 1 -> packet belongs to SG_IO */
/* done protected by rq_list_lock */
char done; /* 0->before bh, 1->before read, 2->read */
atomic_t rq_st; /* request state, holds a enum sg_rq_state */
+ u8 cmd_opcode; /* first byte of SCSI cdb */
+ u64 start_ns; /* starting point of command duration calc */
+ unsigned long frq_bm[1]; /* see SG_FRQ_* defines above */
+ struct sg_fd *parentfp; /* pointer to owning fd, even when on fl */
struct request *rq; /* released in sg_rq_end_io(), bio kept */
struct bio *bio; /* kept until this req -->SG_RS_INACTIVE */
struct execute_work ew_orph; /* harvest orphan request */
@@ -233,7 +237,7 @@ static ssize_t sg_submit(struct sg_fd *sfp, struct file *filp,
const char __user *buf, size_t count, bool blocking,
bool read_only, bool sg_io_owned,
struct sg_request **o_srp);
-static int sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwp);
+static int sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp);
static int sg_rd_append(struct sg_request *srp, void __user *outp,
int num_xfer);
static void sg_remove_sgat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
@@ -243,6 +247,7 @@ static void sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp,
static void sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
static void sg_remove_sfp(struct kref *);
+static struct sg_request *sg_find_srp_by_id(struct sg_fd *sfp, int pack_id);
static struct sg_request *sg_add_request(struct sg_fd *sfp);
static void sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_device *sg_get_dev(int dev);
@@ -454,7 +459,8 @@ sg_open(struct inode *inode, struct file *filp)
sfp = sg_add_sfp(sdp);
if (IS_ERR(sfp)) {
res = PTR_ERR(sfp);
- goto out_undo; }
+ goto out_undo;
+ }
filp->private_data = sfp;
atomic_inc(&sdp->open_cnt);
@@ -522,7 +528,6 @@ sg_release(struct inode *inode, struct file *filp)
static ssize_t
sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
{
- bool blocking = !(filp->f_flags & O_NONBLOCK);
int mxsize, cmd_size, input_size, res;
u8 opcode;
struct sg_device *sdp;
@@ -619,21 +624,19 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
return -EFAULT;
/*
* SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
- * but is is possible that the app intended SG_DXFER_TO_DEV, because there
- * is a non-zero input_size, so emit a warning.
+ * but it is possible that the app intended SG_DXFER_TO_DEV, because
+ * there is a non-zero input_size, so emit a warning.
*/
if (h3p->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
- printk_ratelimited(KERN_WARNING
- "sg_write: data in/out %d/%d bytes "
- "for SCSI command 0x%x-- guessing "
- "data in;\n program %s not setting "
- "count and/or reply_len properly\n",
- ohp->reply_len - (int)SZ_SG_HEADER,
- input_size, (unsigned int) cmnd[0],
- current->comm);
+ printk_ratelimited
+ (KERN_WARNING
+ "%s: data in/out %d/%d bytes for SCSI command 0x%x-- guessing data in;\n"
+ " program %s not setting count and/or reply_len properly\n",
+ __func__, ohp->reply_len - (int)SZ_SG_HEADER,
+ input_size, (unsigned int)cmnd[0], current->comm);
}
cwr.timeout = sfp->timeout;
- cwr.blocking = blocking;
+ cwr.blocking = !(filp->f_flags & O_NONBLOCK);
cwr.srp = srp;
cwr.cmnd = cmnd;
res = sg_common_write(sfp, &cwr);
@@ -661,6 +664,18 @@ sg_fetch_cmnd(struct file *filp, struct sg_fd *sfp, const u8 __user *u_cdbp,
return 0;
}
+static inline int
+sg_chk_mmap(struct sg_fd *sfp, int rq_flags, int len)
+{
+ if (len > sfp->reserve.buflen)
+ return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
+ if (rq_flags & SG_FLAG_DIRECT_IO)
+ return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
+ if (sfp->res_in_use)
+ return -EBUSY; /* reserve buffer already being used */
+ return 0;
+}
+
static ssize_t
sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
size_t count, bool blocking, bool read_only, bool sg_io_owned,
@@ -692,17 +707,10 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
return -ENOSYS;
}
if (hp->flags & SG_FLAG_MMAP_IO) {
- if (hp->dxfer_len > sfp->reserve.buflen) {
- sg_deact_request(sfp, srp);
- return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
- }
- if (hp->flags & SG_FLAG_DIRECT_IO) {
+ res = sg_chk_mmap(sfp, hp->flags, hp->dxfer_len);
+ if (res) {
sg_deact_request(sfp, srp);
- return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
- }
- if (sfp->res_in_use) {
- sg_deact_request(sfp, srp);
- return -EBUSY; /* reserve buffer already being used */
+ return res;
}
}
ul_timeout = msecs_to_jiffies(srp->header.timeout);
@@ -724,6 +732,12 @@ sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
return count;
}
+/*
+ * All writes and submits converge on this function to launch the SCSI
+ * command/request (via blk_execute_rq_nowait). Returns a pointer to a
+ * sg_request object holding the request just issued or a negated errno
+ * value twisted by ERR_PTR.
+ */
static int
sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp)
{
@@ -802,37 +816,45 @@ sg_rstate_chg(struct sg_request *srp, enum sg_rq_state old_st,
* sg_ctl_ioreceive(). wait_event_interruptible will return if this one
* returns true (or an event like a signal (e.g. control-C) occurs).
*/
-
-static struct sg_request *
-sg_get_rq_mark(struct sg_fd *sfp, int pack_id)
+static inline bool
+sg_get_ready_srp(struct sg_fd *sfp, struct sg_request **srpp, int pack_id)
{
- struct sg_request *resp;
- unsigned long iflags;
+ struct sg_request *srp;
- spin_lock_irqsave(&sfp->rq_list_lock, iflags);
- list_for_each_entry(resp, &sfp->rq_list, entry) {
- /* look for requests that are ready + not SG_IO owned */
- if ((resp->done == 1) && (!resp->sg_io_owned) &&
- ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
- resp->done = 2; /* guard against other readers */
- spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return resp;
- }
+ if (unlikely(SG_IS_DETACHING(sfp->parentdp))) {
+ *srpp = NULL;
+ return true;
}
- spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return NULL;
+ srp = sg_find_srp_by_id(sfp, pack_id);
+ *srpp = srp;
+ return !!srp;
}
+/*
+ * Returns number of bytes copied to user space provided sense buffer or
+ * negated errno value.
+ */
static int
-srp_done(struct sg_fd *sfp, struct sg_request *srp)
+sg_copy_sense(struct sg_request *srp)
{
- unsigned long flags;
- int ret;
+ int len = 0;
+ struct sg_io_hdr *hp = &srp->header;
- spin_lock_irqsave(&sfp->rq_list_lock, flags);
- ret = srp->done;
- spin_unlock_irqrestore(&sfp->rq_list_lock, flags);
- return ret;
+ /* If need be, copy the sense buffer to the user space */
+ if ((CHECK_CONDITION & hp->masked_status) ||
+ (DRIVER_SENSE & hp->driver_status)) {
+ int sb_len = SCSI_SENSE_BUFFERSIZE;
+
+ sb_len = (hp->mx_sb_len > sb_len) ? sb_len :
+ hp->mx_sb_len;
+ /* Additional sense length field */
+ len = 8 + (int)srp->sense_b[7];
+ len = (len > sb_len) ? sb_len : len;
+ if (copy_to_user(hp->sbp, srp->sense_b, len))
+ return -EFAULT;
+ hp->sb_len_wr = len;
+ }
+ return len;
}
#if IS_ENABLED(CONFIG_SCSI_LOGGING)
@@ -861,37 +883,32 @@ sg_rep_rq_state_fail(struct sg_fd *sfp, enum sg_rq_state exp_old_st,
}
#endif
-static ssize_t
-sg_v3_receive(struct sg_fd *sfp, char __user *buf, struct sg_request *srp)
+static int
+sg_rec_v3_state(struct sg_fd *sfp, struct sg_request *srp)
{
- struct sg_io_hdr *hp = &srp->header;
int err = 0;
- int len;
-
- hp->sb_len_wr = 0;
- if ((hp->mx_sb_len > 0) && hp->sbp) {
- if ((CHECK_CONDITION & hp->masked_status) ||
- (DRIVER_SENSE & hp->driver_status)) {
- int sb_len = SCSI_SENSE_BUFFERSIZE;
-
- sb_len = (hp->mx_sb_len > sb_len) ? sb_len :
- hp->mx_sb_len;
- /* Additional sense length field */
- len = 8 + (int) srp->sense_b[7];
- len = (len > sb_len) ? sb_len : len;
- if (copy_to_user(hp->sbp, srp->sense_b, len)) {
- err = -EFAULT;
- goto err_out;
- }
- hp->sb_len_wr = len;
- }
- }
+ int sb_len_wr;
+
+ sb_len_wr = sg_copy_sense(srp);
+ if (sb_len_wr < 0)
+ return sb_len_wr;
+ if (unlikely(SG_IS_DETACHING(sfp->parentdp)))
+ err = -ENODEV;
+ return err;
+}
+
+static int
+sg_v3_receive(struct sg_fd *sfp, struct sg_request *srp, void __user *p)
+{
+ int err = 0;
+ struct sg_io_hdr *hp = &srp->header;
+
+ SG_LOG(3, sfp, "%s: srp=0x%p\n", __func__, srp);
+ err = sg_rec_v3_state(sfp, srp);
if (hp->masked_status || hp->host_status || hp->driver_status)
hp->info |= SG_INFO_CHECK;
- if (copy_to_user(buf, hp, SZ_SG_IO_HDR))
+ if (copy_to_user(p, hp, SZ_SG_IO_HDR))
err = -EFAULT;
-
-err_out:
sg_finish_scsi_blk_rq(srp);
sg_deact_request(sfp, srp);
return err ? err : 0;
@@ -970,16 +987,22 @@ sg_rd_v1v2(void __user *buf, int count, struct sg_fd *sfp,
return res;
}
+/*
+ * This is the read(2) system call entry point (see sg_fops) for this driver.
+ * Accepts v1, v2 or v3 type headers (not v4). Returns count or negated
+ * errno; if count is 0 then v3: returns -EINVAL; v1+v2: 0 when no other
+ * error detected or -EIO.
+ */
static ssize_t
sg_read(struct file *filp, char __user *p, size_t count, loff_t *ppos)
{
bool could_be_v3;
bool non_block = !!(filp->f_flags & O_NONBLOCK);
- int want_id = -1;
+ int want_id = SG_PACK_ID_WILDCARD;
int hlen, ret;
- struct sg_device *sdp;
+ struct sg_device *sdp = NULL;
struct sg_fd *sfp;
- struct sg_request *srp;
+ struct sg_request *srp = NULL;
struct sg_header *h2p = NULL;
struct sg_io_hdr a_sg_io_hdr;
@@ -994,7 +1017,7 @@ sg_read(struct file *filp, char __user *p, size_t count, loff_t *ppos)
sfp = filp->private_data;
sdp = sfp->parentdp;
SG_LOG(3, sfp, "%s: read() count=%d\n", __func__, (int)count);
- ret = sg_allow_if_err_recovery(sdp, false);
+ ret = sg_allow_if_err_recovery(sdp, non_block);
if (ret)
return ret;
@@ -1013,17 +1036,13 @@ sg_read(struct file *filp, char __user *p, size_t count, loff_t *ppos)
if (h2p->reply_len < 0 && could_be_v3) {
struct sg_io_hdr *v3_hdr = (struct sg_io_hdr *)h2p;
- if (likely(v3_hdr->interface_id == 'S')) {
+ if (v3_hdr->interface_id == 'S') {
struct sg_io_hdr __user *h3_up;
h3_up = (struct sg_io_hdr __user *)p;
ret = get_user(want_id, &h3_up->pack_id);
- if (unlikely(ret))
+ if (ret)
return ret;
- } else if (v3_hdr->interface_id == 'Q') {
- pr_info_once("sg: %s: v4 interface%s here\n",
- __func__, " disallowed");
- return -EPERM;
} else {
return -EPERM;
}
@@ -1031,27 +1050,27 @@ sg_read(struct file *filp, char __user *p, size_t count, loff_t *ppos)
want_id = h2p->pack_id;
}
}
- srp = sg_get_rq_mark(sfp, want_id);
- if (!srp) { /* now wait on packet to arrive */
+ srp = sg_find_srp_by_id(sfp, want_id);
+ if (!srp) { /* nothing available so wait on packet to arrive or */
if (SG_IS_DETACHING(sdp))
return -ENODEV;
if (non_block) /* O_NONBLOCK or v3::flags & SGV4_FLAG_IMMED */
return -EAGAIN;
- ret = wait_event_interruptible
- (sfp->read_wait,
- (SG_IS_DETACHING(sdp) ||
- (srp = sg_get_rq_mark(sfp, want_id))));
+ ret = wait_event_interruptible(sfp->read_wait,
+ sg_get_ready_srp(sfp, &srp,
+ want_id));
if (SG_IS_DETACHING(sdp))
return -ENODEV;
if (ret) /* -ERESTARTSYS as signal hit process */
return ret;
+ /* otherwise srp should be valid */
}
if (srp->header.interface_id == '\0') {
ret = sg_rd_v1v2(p, (int)count, sfp, srp);
} else {
if ((int)count < SZ_SG_IO_HDR)
return -EINVAL;
- ret = sg_v3_receive(sfp, p, srp);
+ ret = sg_v3_receive(sfp, srp, p);
}
if (ret < 0)
SG_LOG(1, sfp, "%s: negated errno: %d\n", __func__, ret);
@@ -1101,6 +1120,52 @@ sg_calc_sgat_param(struct sg_device *sdp)
sdp->max_sgat_sz = sz;
}
+static u32
+sg_calc_rq_dur(const struct sg_request *srp)
+{
+ ktime_t ts0 = srp->start_ns;
+ ktime_t now_ts;
+ s64 diff;
+
+ if (ts0 == 0)
+ return 0;
+ if (unlikely(ts0 == U64_MAX)) /* _prior_ to issuing req */
+ return 999999999; /* eye catching */
+ now_ts = ktime_get_boottime_ns();
+ if (unlikely(ts0 > now_ts))
+ return 999999998;
+ /* unlikely req duration will exceed 2**32 milliseconds */
+ diff = ktime_ms_delta(now_ts, ts0);
+ return (diff > (s64)U32_MAX) ? 3999999999U : (u32)diff;
+}
+
+/* Return of U32_MAX means srp is inactive or in slave waiting state */
+static u32
+sg_get_dur(struct sg_request *srp, const enum sg_rq_state *sr_stp,
+ bool *is_durp)
+{
+ bool is_dur = false;
+ u32 res = U32_MAX;
+
+ switch (sr_stp ? *sr_stp : atomic_read(&srp->rq_st)) {
+ case SG_RS_INFLIGHT:
+ case SG_RS_BUSY:
+ res = sg_calc_rq_dur(srp);
+ break;
+ case SG_RS_AWAIT_RD:
+ case SG_RS_DONE_RD:
+ res = srp->duration;
+ is_dur = true; /* completion has occurred, timing finished */
+ break;
+ case SG_RS_INACTIVE:
+ default:
+ break;
+ }
+ if (is_durp)
+ *is_durp = is_dur;
+ return res;
+}
+
static void
sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
{
@@ -1117,6 +1182,7 @@ sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
srp->header.masked_status &
srp->header.host_status &
srp->header.driver_status;
+ rinfo[val].duration = sg_get_dur(srp, NULL, NULL); /* dummy */
if (srp->done)
rinfo[val].duration =
srp->header.duration;
@@ -1134,6 +1200,18 @@ sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
}
}
+static int
+srp_done(struct sg_fd *sfp, struct sg_request *srp)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&sfp->rq_list_lock, flags);
+ ret = srp->done;
+ spin_unlock_irqrestore(&sfp->rq_list_lock, flags);
+ return ret;
+}
+
/*
* Handles ioctl(SG_IO) for blocking (sync) usage of v3 or v4 interface.
* Returns 0 on success else a negated errno.
@@ -1161,7 +1239,7 @@ sg_ctl_sg_io(struct file *filp, struct sg_device *sdp, struct sg_fd *sfp,
if (srp->done) {
srp->done = 2;
spin_unlock_irq(&sfp->rq_list_lock);
- res = sg_v3_receive(sfp, p, srp);
+ res = sg_v3_receive(sfp, srp, p);
return (res < 0) ? res : 0;
}
srp->orphan = 1;
@@ -1361,7 +1439,9 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
return result;
if (val > SG_MAX_CDB_SIZE)
return -ENOMEM;
- sfp->next_cmd_len = (val > 0) ? val : 0;
+ mutex_lock(&sfp->f_mutex);
+ sfp->next_cmd_len = max_t(int, val, 0);
+ mutex_unlock(&sfp->f_mutex);
return 0;
case SG_GET_ACCESS_COUNT:
SG_LOG(3, sfp, "%s: SG_GET_ACCESS_COUNT\n", __func__);
@@ -2306,6 +2386,33 @@ sg_rd_append(struct sg_request *srp, void __user *outp, int num_xfer)
return res;
}
+/*
+ * If there are multiple requests outstanding, the speed of this function is
+ * important. SG_PACK_ID_WILDCARD is -1 and that case is typically
+ * the fast path. This function is only used in the non-blocking cases.
+ * Returns pointer to (first) matching sg_request or NULL. If found,
+ * sg_request state is moved from SG_RS_AWAIT_RD to SG_RS_BUSY.
+ */
+static struct sg_request *
+sg_find_srp_by_id(struct sg_fd *sfp, int pack_id)
+{
+ unsigned long iflags;
+ struct sg_request *resp;
+
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
+ list_for_each_entry(resp, &sfp->rq_list, entry) {
+ /* look for requests that are ready + not SG_IO owned */
+ if (resp->done == 1 && !resp->sg_io_owned &&
+ (-1 == pack_id || resp->header.pack_id == pack_id)) {
+ resp->done = 2; /* guard against other readers */
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ return resp;
+ }
+ }
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ return NULL;
+}
+
static void
sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp, int size)
{
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 21/23] sg: sg_find_srp_by_id
2019-10-08 7:50 ` [PATCH v5 21/23] sg: sg_find_srp_by_id Douglas Gilbert
@ 2019-10-18 10:27 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:27 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Replace sg_get_rq_mark() with sg_find_srp_by_id() and
> sg_get_ready_srp(). Add sg_chk_mmap() to check flags and
> reserve buffer available for mmap() based requests. Add
> sg_copy_sense() and sg_rec_v3_state() which is just
> refactoring. Add sg_calc_rq_dur() and sg_get_dur() in
> preparation for optional nanosecond duration timing.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 293 +++++++++++++++++++++++++++++++---------------
> 1 file changed, 200 insertions(+), 93 deletions(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 4e6f6fb2a54e..7f3a4b937a5a 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -158,16 +158,20 @@ struct sg_fd;
>
> struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
> struct list_head entry; /* list entry */
> - struct sg_fd *parentfp; /* NULL -> not in use */
> struct sg_scatter_hold data; /* hold buffer, perhaps scatter list */
> struct sg_io_hdr header; /* scsi command+info, see <scsi/sg.h> */
> u8 sense_b[SCSI_SENSE_BUFFERSIZE];
> + u32 duration; /* cmd duration in milliseconds */
> char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
> char orphan; /* 1 -> drop on sight, 0 -> normal */
> char sg_io_owned; /* 1 -> packet belongs to SG_IO */
> /* done protected by rq_list_lock */
> char done; /* 0->before bh, 1->before read, 2->read */
> atomic_t rq_st; /* request state, holds a enum sg_rq_state */
> + u8 cmd_opcode; /* first byte of SCSI cdb */
> + u64 start_ns; /* starting point of command duration calc */
> + unsigned long frq_bm[1]; /* see SG_FRQ_* defines above */
> + struct sg_fd *parentfp; /* pointer to owning fd, even when on fl */
> struct request *rq; /* released in sg_rq_end_io(), bio kept */
> struct bio *bio; /* kept until this req -->SG_RS_INACTIVE */
> struct execute_work ew_orph; /* harvest orphan request */
cmd_opcode is used where?
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 22/23] sg: sg_fill_request_element
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (20 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 21/23] sg: sg_find_srp_by_id Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
2019-10-18 10:29 ` Hannes Reinecke
2019-10-08 7:50 ` [PATCH v5 23/23] sg: printk change %p to %pK Douglas Gilbert
22 siblings, 1 reply; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
Replace sg_fill_request_table() with sg_fill_request_element().
Reduce the size of the sg_rq_end_io() function by breaking out
some sense buffer checks into sg_check_sense(). Reduce the
size of the sg_start_req() function with sg_set_map_data()
helper. All code refactoring, no logical change.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 211 ++++++++++++++++++++++++++--------------------
1 file changed, 118 insertions(+), 93 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 7f3a4b937a5a..aaae37ab77ba 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -164,6 +164,7 @@ struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
u32 duration; /* cmd duration in milliseconds */
char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
char orphan; /* 1 -> drop on sight, 0 -> normal */
+ u32 rq_result; /* packed scsi request result from LLD */
char sg_io_owned; /* 1 -> packet belongs to SG_IO */
/* done protected by rq_list_lock */
char done; /* 0->before bh, 1->before read, 2->read */
@@ -643,6 +644,18 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos)
return (res < 0) ? res : count;
}
+static inline int
+sg_chk_mmap(struct sg_fd *sfp, int rq_flags, int len)
+{
+ if (len > sfp->reserve.buflen)
+ return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
+ if (rq_flags & SG_FLAG_DIRECT_IO)
+ return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
+ if (sfp->res_in_use)
+ return -EBUSY; /* reserve buffer already being used */
+ return 0;
+}
+
static int
sg_fetch_cmnd(struct file *filp, struct sg_fd *sfp, const u8 __user *u_cdbp,
int len, u8 *cdbp)
@@ -664,18 +677,6 @@ sg_fetch_cmnd(struct file *filp, struct sg_fd *sfp, const u8 __user *u_cdbp,
return 0;
}
-static inline int
-sg_chk_mmap(struct sg_fd *sfp, int rq_flags, int len)
-{
- if (len > sfp->reserve.buflen)
- return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
- if (rq_flags & SG_FLAG_DIRECT_IO)
- return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
- if (sfp->res_in_use)
- return -EBUSY; /* reserve buffer already being used */
- return 0;
-}
-
static ssize_t
sg_submit(struct sg_fd *sfp, struct file *filp, const char __user *buf,
size_t count, bool blocking, bool read_only, bool sg_io_owned,
@@ -897,6 +898,11 @@ sg_rec_v3_state(struct sg_fd *sfp, struct sg_request *srp)
return err;
}
+/*
+ * Completes a v3 request/command. Called from sg_read {v2 or v3},
+ * ioctl(SG_IO) {for v3}, or from ioctl(SG_IORECEIVE) when its
+ * completing a v3 request/command.
+ */
static int
sg_v3_receive(struct sg_fd *sfp, struct sg_request *srp, void __user *p)
{
@@ -1167,37 +1173,28 @@ sg_get_dur(struct sg_request *srp, const enum sg_rq_state *sr_stp,
}
static void
-sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
+sg_fill_request_element(struct sg_fd *sfp, struct sg_request *srp,
+ struct sg_req_info *rip)
{
- struct sg_request *srp;
- int val;
unsigned int ms;
- val = 0;
- list_for_each_entry(srp, &sfp->rq_list, entry) {
- if (val >= SG_MAX_QUEUE)
- break;
- rinfo[val].req_state = srp->done + 1;
- rinfo[val].problem =
- srp->header.masked_status &
- srp->header.host_status &
- srp->header.driver_status;
- rinfo[val].duration = sg_get_dur(srp, NULL, NULL); /* dummy */
- if (srp->done)
- rinfo[val].duration =
- srp->header.duration;
- else {
- ms = jiffies_to_msecs(jiffies);
- rinfo[val].duration =
- (ms > srp->header.duration) ?
+ rip->req_state = srp->done + 1;
+ rip->problem = srp->header.masked_status &
+ srp->header.host_status &
+ srp->header.driver_status;
+ rip->duration = sg_get_dur(srp, NULL, NULL); /* dummy */
+ if (srp->done) {
+ rip->duration = srp->header.duration;
+ } else {
+ ms = jiffies_to_msecs(jiffies);
+ rip->duration = (ms > srp->header.duration) ?
(ms - srp->header.duration) : 0;
- }
- rinfo[val].orphan = srp->orphan;
- rinfo[val].sg_io_owned = srp->sg_io_owned;
- rinfo[val].pack_id = srp->header.pack_id;
- rinfo[val].usr_ptr = srp->header.usr_ptr;
- val++;
}
+ rip->orphan = srp->orphan;
+ rip->sg_io_owned = srp->sg_io_owned;
+ rip->pack_id = srp->header.pack_id;
+ rip->usr_ptr = srp->header.usr_ptr;
+
}
static int
@@ -1264,21 +1261,28 @@ sg_set_reserved_sz(struct sg_fd *sfp, int want_rsv_sz)
static int
sg_ctl_req_tbl(struct sg_fd *sfp, void __user *p)
{
- int result;
+ int result, val;
unsigned long iflags;
- sg_req_info_t *rinfo;
+ struct sg_request *srp;
+ sg_req_info_t *rinfop;
- rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
- GFP_KERNEL);
- if (!rinfo)
+ rinfop = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
+ GFP_KERNEL);
+ if (!rinfop)
return -ENOMEM;
spin_lock_irqsave(&sfp->rq_list_lock, iflags);
- sg_fill_request_table(sfp, rinfo);
+ val = 0;
+ list_for_each_entry(srp, &sfp->rq_list, entry) {
+ if (val >= SG_MAX_QUEUE)
+ break;
+ sg_fill_request_element(sfp, srp, rinfop + val);
+ val++;
+ }
spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- result = copy_to_user(p, rinfo,
+ result = copy_to_user(p, rinfop,
SZ_SG_REQ_INFO * SG_MAX_QUEUE);
result = result ? -EFAULT : 0;
- kfree(rinfo);
+ kfree(rinfop);
return result;
}
@@ -1339,7 +1343,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
return result;
sfp->force_packid = val ? 1 : 0;
return 0;
- case SG_GET_PACK_ID:
+ case SG_GET_PACK_ID: /* or tag of oldest "read"-able, -1 if none */
val = -1;
spin_lock_irqsave(&sfp->rq_list_lock, iflags);
list_for_each_entry(srp, &sfp->rq_list, entry) {
@@ -1703,6 +1707,39 @@ sg_rq_end_io_usercontext(struct work_struct *work)
kref_put(&sfp->f_ref, sg_remove_sfp);
}
+static void
+sg_check_sense(struct sg_device *sdp, struct sg_request *srp, int sense_len)
+{
+ int driver_stat;
+ u32 rq_res = srp->rq_result;
+ struct scsi_request *scsi_rp = scsi_req(srp->rq);
+ u8 *sbp = scsi_rp ? scsi_rp->sense : NULL;
+
+ if (!sbp)
+ return;
+ driver_stat = driver_byte(rq_res);
+ if (driver_stat & DRIVER_SENSE) {
+ struct scsi_sense_hdr ssh;
+
+ if (scsi_normalize_sense(sbp, sense_len, &ssh)) {
+ if (!scsi_sense_is_deferred(&ssh)) {
+ if (ssh.sense_key == UNIT_ATTENTION) {
+ if (sdp->device->removable)
+ sdp->device->changed = 1;
+ }
+ }
+ }
+ }
+ if (test_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm) > 0) {
+ int scsi_stat = rq_res & 0xff;
+
+ if (scsi_stat == SAM_STAT_CHECK_CONDITION ||
+ scsi_stat == SAM_STAT_COMMAND_TERMINATED)
+ __scsi_print_sense(sdp->device, __func__, sbp,
+ sense_len);
+ }
+}
+
/*
* This function is a "bottom half" handler that is called by the mid
* level when a command is completed (or has failed).
@@ -1711,13 +1748,13 @@ static void
sg_rq_end_io(struct request *rq, blk_status_t status)
{
struct sg_request *srp = rq->end_io_data;
- struct scsi_request *req = scsi_req(rq);
+ struct scsi_request *scsi_rp = scsi_req(rq);
struct sg_device *sdp;
struct sg_fd *sfp;
unsigned long iflags;
unsigned int ms;
- char *sense;
- int result, resid, done = 1;
+ int resid, slen;
+ int done = 1;
if (WARN_ON(srp->done != 0))
return;
@@ -1730,44 +1767,22 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
if (unlikely(SG_IS_DETACHING(sdp)))
pr_info("%s: device detaching\n", __func__);
- sense = req->sense;
- result = req->result;
- resid = req->resid_len;
+ srp->rq_result = scsi_rp->result;
+ resid = scsi_rp->resid_len;
srp->header.resid = resid;
+
+ slen = min_t(int, scsi_rp->sense_len, SCSI_SENSE_BUFFERSIZE);
+
SG_LOG(6, sfp, "%s: pack_id=%d, res=0x%x\n", __func__,
- srp->header.pack_id, result);
+ srp->header.pack_id, srp->rq_result);
ms = jiffies_to_msecs(jiffies);
srp->header.duration = (ms > srp->header.duration) ?
(ms - srp->header.duration) : 0;
- if (0 != result) {
- struct scsi_sense_hdr sshdr;
-
- srp->header.status = 0xff & result;
- srp->header.masked_status = status_byte(result);
- srp->header.msg_status = msg_byte(result);
- srp->header.host_status = host_byte(result);
- srp->header.driver_status = driver_byte(result);
- if (test_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm) &&
- (srp->header.masked_status == CHECK_CONDITION ||
- srp->header.masked_status == COMMAND_TERMINATED))
- __scsi_print_sense(sdp->device, __func__, sense,
- SCSI_SENSE_BUFFERSIZE);
-
- /* Following if statement is a patch supplied by Eric Youngdale */
- if (driver_byte(result) != 0
- && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
- && !scsi_sense_is_deferred(&sshdr)
- && sshdr.sense_key == UNIT_ATTENTION
- && sdp->device->removable) {
- /* Detected possible disc change. Set the bit - this */
- /* may be used if there are filesystems using this device */
- sdp->device->changed = 1;
- }
- }
-
- if (req->sense_len)
- memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
+ if (srp->rq_result != 0 && slen > 0)
+ sg_check_sense(sdp, srp, slen);
+ if (slen > 0)
+ memcpy(srp->sense_b, scsi_rp->sense, slen);
/* Rely on write phase to clean out srp status values, so no "else" */
@@ -1826,6 +1841,7 @@ static struct class *sg_sysfs_class;
static bool sg_sysfs_valid;
+/* Returns valid pointer to sg_device or negated errno twisted by ERR_PTR */
static struct sg_device *
sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
{
@@ -2038,6 +2054,7 @@ init_sg(void)
{
int rc;
+ /* check scatter_elem_sz module parameter, change if inappropriate */
if (scatter_elem_sz < (int)PAGE_SIZE)
scatter_elem_sz = PAGE_SIZE;
else if (scatter_elem_sz != (1 << ilog2(scatter_elem_sz)))
@@ -2052,8 +2069,11 @@ init_sg(void)
SG_MAX_DEVS, "sg");
if (rc)
return rc;
- sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
- if ( IS_ERR(sg_sysfs_class) ) {
+ pr_info("Registered %s[char major=0x%x], version: %s, date: %s\n",
+ "sg device ", SCSI_GENERIC_MAJOR, SG_VERSION_STR,
+ sg_version_date);
+ sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
+ if (IS_ERR(sg_sysfs_class)) {
rc = PTR_ERR(sg_sysfs_class);
goto err_out_unreg;
}
@@ -2090,6 +2110,18 @@ exit_sg(void)
idr_destroy(&sg_index_idr);
}
+static void
+sg_set_map_data(const struct sg_scatter_hold *schp, bool up_valid,
+ struct rq_map_data *mdp)
+{
+ memset(mdp, 0, sizeof(*mdp));
+ mdp->pages = schp->pages;
+ mdp->page_order = schp->page_order;
+ mdp->nr_entries = schp->num_sgat;
+ mdp->offset = 0;
+ mdp->null_mapped = !up_valid;
+}
+
static int
sg_start_req(struct sg_request *srp, u8 *cmd)
{
@@ -2177,15 +2209,8 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
}
mutex_unlock(&sfp->f_mutex);
- md->pages = req_schp->pages;
- md->page_order = req_schp->page_order;
- md->nr_entries = req_schp->num_sgat;
- md->offset = 0;
- md->null_mapped = hp->dxferp ? 0 : 1;
- if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
- md->from_user = 1;
- else
- md->from_user = 0;
+ sg_set_map_data(req_schp, !!hp->dxferp, md);
+ md->from_user = (dxfer_dir == SG_DXFER_TO_FROM_DEV);
}
if (iov_count) {
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread* Re: [PATCH v5 22/23] sg: sg_fill_request_element
2019-10-08 7:50 ` [PATCH v5 22/23] sg: sg_fill_request_element Douglas Gilbert
@ 2019-10-18 10:29 ` Hannes Reinecke
0 siblings, 0 replies; 43+ messages in thread
From: Hannes Reinecke @ 2019-10-18 10:29 UTC (permalink / raw)
To: Douglas Gilbert, linux-scsi; +Cc: martin.petersen, jejb
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Replace sg_fill_request_table() with sg_fill_request_element().
> Reduce the size of the sg_rq_end_io() function by breaking out
> some sense buffer checks into sg_check_sense(). Reduce the
> size of the sg_start_req() function with sg_set_map_data()
> helper. All code refactoring, no logical change.
>
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
> drivers/scsi/sg.c | 211 ++++++++++++++++++++++++++--------------------
> 1 file changed, 118 insertions(+), 93 deletions(-)
>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
^ permalink raw reply [flat|nested] 43+ messages in thread
* [PATCH v5 23/23] sg: printk change %p to %pK
2019-10-08 7:49 [PATCH v5 00/23] sg: add v4 interface Douglas Gilbert
` (21 preceding siblings ...)
2019-10-08 7:50 ` [PATCH v5 22/23] sg: sg_fill_request_element Douglas Gilbert
@ 2019-10-08 7:50 ` Douglas Gilbert
22 siblings, 0 replies; 43+ messages in thread
From: Douglas Gilbert @ 2019-10-08 7:50 UTC (permalink / raw)
To: linux-scsi; +Cc: martin.petersen, jejb, hare
This driver does a lot of buffer juggling in an attempt to
take some of that chore away from its users. When debugging
problems associated with that buffer juggling getting
sensible pointer values is a major aid. So change %p
to %pK. The system administrator can choose to obfuscate
%pK pointers. They are also easier to search for.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index aaae37ab77ba..dc8f19f6ce26 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -909,7 +909,7 @@ sg_v3_receive(struct sg_fd *sfp, struct sg_request *srp, void __user *p)
int err = 0;
struct sg_io_hdr *hp = &srp->header;
- SG_LOG(3, sfp, "%s: srp=0x%p\n", __func__, srp);
+ SG_LOG(3, sfp, "%s: srp=0x%pK\n", __func__, srp);
err = sg_rec_v3_state(sfp, srp);
if (hp->masked_status || hp->host_status || hp->driver_status)
hp->info |= SG_INFO_CHECK;
@@ -1653,7 +1653,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
return -ENXIO;
}
req_sz = vma->vm_end - vma->vm_start;
- SG_LOG(3, sfp, "%s: vm_start=%p, len=%d\n", __func__,
+ SG_LOG(3, sfp, "%s: vm_start=%pK, len=%d\n", __func__,
(void *)vma->vm_start, (int)req_sz);
if (vma->vm_pgoff)
return -EINVAL; /* only an offset of 0 accepted */
@@ -1701,7 +1701,7 @@ sg_rq_end_io_usercontext(struct work_struct *work)
WARN_ONCE(1, "%s: sfp unexpectedly NULL\n", __func__);
return;
}
- SG_LOG(3, sfp, "%s: srp=0x%p\n", __func__, srp);
+ SG_LOG(3, sfp, "%s: srp=0x%pK\n", __func__, srp);
sg_finish_scsi_blk_rq(srp);
sg_deact_request(sfp, srp);
kref_put(&sfp->f_ref, sg_remove_sfp);
@@ -1874,7 +1874,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
k = error;
SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
- "%s: dev=%d, sdp=0x%p ++\n", __func__, k, sdp));
+ "%s: dev=%d, sdp=0x%pK ++\n", __func__, k, sdp));
sprintf(disk->disk_name, "sg%d", k);
disk->first_minor = k;
sdp->disk = disk;
@@ -1993,7 +1993,7 @@ sg_device_destroy(struct kref *kref)
idr_remove(&sg_index_idr, sdp->index);
write_unlock_irqrestore(&sg_index_lock, flags);
- sdev_printk(KERN_INFO, sdp->device, "[tid=%d] %s: sdp=0x%p --\n",
+ sdev_printk(KERN_INFO, sdp->device, "[tid=%d] %s: sdp=0x%pK --\n",
(current ? current->pid : -1), __func__, sdp);
put_disk(sdp->disk);
@@ -2015,7 +2015,7 @@ sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
return; /* only want to do following once per device */
SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, sdp->device,
- "%s: 0x%p\n", __func__, sdp));
+ "%s: 0x%pK\n", __func__, sdp));
read_lock_irqsave(&sdp->sfd_lock, iflags);
list_for_each_entry(sfp, &sdp->sfds, sfd_entry) {
@@ -2144,7 +2144,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
if (!long_cmdp)
return -ENOMEM;
- SG_LOG(5, sfp, "%s: long_cmdp=0x%p ++\n", __func__, long_cmdp);
+ SG_LOG(5, sfp, "%s: long_cmdp=0x%pK ++\n", __func__, long_cmdp);
}
SG_LOG(4, sfp, "%s: dxfer_len=%d, data-%s\n", __func__, dxfer_len,
(r0w ? "OUT" : "IN"));
@@ -2252,7 +2252,7 @@ sg_finish_scsi_blk_rq(struct sg_request *srp)
struct sg_fd *sfp = srp->parentfp;
struct sg_scatter_hold *req_schp = &srp->data;
- SG_LOG(4, sfp, "%s: srp=0x%p%s\n", __func__, srp,
+ SG_LOG(4, sfp, "%s: srp=0x%pK%s\n", __func__, srp,
(srp->res_used) ? " rsv" : "");
if (!srp->sg_io_owned) {
atomic_dec(&sfp->submitted);
@@ -2298,7 +2298,7 @@ sg_mk_sgat(struct sg_scatter_hold *schp, struct sg_fd *sfp, int minlen)
align_sz = ALIGN(m_size, SG_DEF_SECTOR_SZ);
schp->pages = kcalloc(mx_sgat_elems, struct_page_sz, mask_kz);
- SG_LOG(4, sfp, "%s: minlen=%d, align_sz=%d [sz=%zu, 0x%p ++]\n",
+ SG_LOG(4, sfp, "%s: minlen=%d, align_sz=%d [sz=%zu, 0x%pK ++]\n",
__func__, minlen, align_sz, mx_sgat_elems * struct_page_sz,
schp->pages);
if (unlikely(!schp->pages))
@@ -2317,7 +2317,7 @@ sg_mk_sgat(struct sg_scatter_hold *schp, struct sg_fd *sfp, int minlen)
schp->pages[k] = alloc_pages(mask_ap, order);
if (!schp->pages[k])
goto err_out;
- SG_LOG(5, sfp, "%s: k=%d, rup_sz=%d [0x%p ++]\n", __func__, k,
+ SG_LOG(5, sfp, "%s: k=%d, rup_sz=%d [0x%pK ++]\n", __func__, k,
rup_sz, schp->pages[k]);
}
schp->page_order = order;
@@ -2347,12 +2347,12 @@ sg_remove_sgat_helper(struct sg_fd *sfp, struct sg_scatter_hold *schp)
return;
for (k = 0; k < schp->num_sgat; ++k) {
p = schp->pages[k];
- SG_LOG(5, sfp, "%s: pg[%d]=0x%p --\n", __func__, k, p);
+ SG_LOG(5, sfp, "%s: pg[%d]=0x%pK --\n", __func__, k, p);
if (unlikely(!p))
continue;
__free_pages(p, schp->page_order);
}
- SG_LOG(5, sfp, "%s: pg_order=%u, free pgs=0x%p --\n", __func__,
+ SG_LOG(5, sfp, "%s: pg_order=%u, free pgs=0x%pK --\n", __func__,
schp->page_order, schp->pages);
kfree(schp->pages);
}
@@ -2589,7 +2589,7 @@ sg_add_sfp(struct sg_device *sdp)
}
list_add_tail(&sfp->sfd_entry, &sdp->sfds);
write_unlock_irqrestore(&sdp->sfd_lock, iflags);
- SG_LOG(3, sfp, "%s: sfp=0x%p\n", __func__, sfp);
+ SG_LOG(3, sfp, "%s: sfp=0x%pK\n", __func__, sfp);
if (unlikely(sg_big_buff != def_reserved_size))
sg_big_buff = def_reserved_size;
@@ -2599,7 +2599,7 @@ sg_add_sfp(struct sg_device *sdp)
kref_get(&sdp->d_ref);
__module_get(THIS_MODULE);
- SG_LOG(3, sfp, "%s: success, sfp=0x%p ++\n", __func__, sfp);
+ SG_LOG(3, sfp, "%s: success, sfp=0x%pK ++\n", __func__, sfp);
return sfp;
}
@@ -2642,7 +2642,7 @@ sg_remove_sfp_usercontext(struct work_struct *work)
sg_remove_sgat(sfp, &sfp->reserve);
}
- SG_LOG(6, sfp, "%s: sfp=0x%p\n", __func__, sfp);
+ SG_LOG(6, sfp, "%s: sfp=0x%pK\n", __func__, sfp);
kfree(sfp);
if (sdp) {
--
2.23.0
^ permalink raw reply related [flat|nested] 43+ messages in thread