From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Denis Efremov <efremov@linux.com>,
"David S. Miller" <davem@davemloft.net>,
Song Liu <song@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>,
Finn Thain <fthain@telegraphics.com.au>,
Michael Schmitz <schmitzmic@gmail.com>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-ide@vger.kernel.org, linux-raid@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-m68k@lists.linux-m68k.org
Subject: [PATCH 15/18] ataflop: use a separate gendisk for each media format
Date: Thu, 29 Oct 2020 15:58:38 +0100 [thread overview]
Message-ID: <20201029145841.144173-16-hch@lst.de> (raw)
In-Reply-To: <20201029145841.144173-1-hch@lst.de>
The Atari floppy driver usually autodetects the media when used with the
ormal /dev/fd? devices, which also are the only nodes created by udev.
But it also supports various aliases that force a given media format.
That is currently supported using the blk_register_region framework
which finds the floppy gendisk even for a 'mismatched' dev_t. The
problem with this (besides the code complexity) is that it creates
multiple struct block_device instances for the whole device of a
single gendisk, which can lead to interesting issues in code not
aware of that fact.
To fix this just create a separate gendisk for each of the aliases
if they are accessed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/block/ataflop.c | 135 +++++++++++++++++++++++++---------------
1 file changed, 86 insertions(+), 49 deletions(-)
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 3e881fdb06e0ad..104b713f4055af 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -297,7 +297,7 @@ static struct atari_floppy_struct {
unsigned int wpstat; /* current state of WP signal (for
disk change detection) */
int flags; /* flags */
- struct gendisk *disk;
+ struct gendisk *disk[NUM_DISK_MINORS];
int ref;
int type;
struct blk_mq_tag_set tag_set;
@@ -723,12 +723,16 @@ static void fd_error( void )
static int do_format(int drive, int type, struct atari_format_descr *desc)
{
- struct request_queue *q = unit[drive].disk->queue;
+ struct request_queue *q;
unsigned char *p;
int sect, nsect;
unsigned long flags;
int ret;
+ if (type)
+ type--;
+
+ q = unit[drive].disk[type]->queue;
blk_mq_freeze_queue(q);
blk_mq_quiesce_queue(q);
@@ -738,7 +742,7 @@ static int do_format(int drive, int type, struct atari_format_descr *desc)
local_irq_restore(flags);
if (type) {
- if (--type >= NUM_DISK_MINORS ||
+ if (type >= NUM_DISK_MINORS ||
minor2disktype[type].drive_types > DriveType) {
ret = -EINVAL;
goto out;
@@ -1154,7 +1158,7 @@ static void fd_rwsec_done1(int status)
if (SUDT[-1].blocks > ReqBlock) {
/* try another disk type */
SUDT--;
- set_capacity(unit[SelectedDrive].disk,
+ set_capacity(unit[SelectedDrive].disk[0],
SUDT->blocks);
} else
Probing = 0;
@@ -1169,7 +1173,7 @@ static void fd_rwsec_done1(int status)
/* record not found, but not probing. Maybe stretch wrong ? Restart probing */
if (SUD.autoprobe) {
SUDT = atari_disk_type + StartDiskType[DriveType];
- set_capacity(unit[SelectedDrive].disk,
+ set_capacity(unit[SelectedDrive].disk[0],
SUDT->blocks);
Probing = 1;
}
@@ -1515,7 +1519,7 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx,
if (!UDT) {
Probing = 1;
UDT = atari_disk_type + StartDiskType[DriveType];
- set_capacity(floppy->disk, UDT->blocks);
+ set_capacity(bd->rq->rq_disk, UDT->blocks);
UD.autoprobe = 1;
}
}
@@ -1533,7 +1537,7 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx,
}
type = minor2disktype[type].index;
UDT = &atari_disk_type[type];
- set_capacity(floppy->disk, UDT->blocks);
+ set_capacity(bd->rq->rq_disk, UDT->blocks);
UD.autoprobe = 0;
}
@@ -1658,7 +1662,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
printk (KERN_INFO "floppy%d: setting %s %p!\n",
drive, dtp->name, dtp);
UDT = dtp;
- set_capacity(floppy->disk, UDT->blocks);
+ set_capacity(disk, UDT->blocks);
if (cmd == FDDEFPRM) {
/* save settings as permanent default type */
@@ -1702,7 +1706,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
return -EINVAL;
UDT = dtp;
- set_capacity(floppy->disk, UDT->blocks);
+ set_capacity(disk, UDT->blocks);
return 0;
case FDMSGON:
@@ -1725,7 +1729,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
UDT = NULL;
/* MSch: invalidate default_params */
default_params[drive].blocks = 0;
- set_capacity(floppy->disk, MAX_DISK_SIZE * 2);
+ set_capacity(disk, MAX_DISK_SIZE * 2);
fallthrough;
case FDFMTEND:
case FDFLUSH:
@@ -1962,14 +1966,50 @@ static const struct blk_mq_ops ataflop_mq_ops = {
.commit_rqs = ataflop_commit_rqs,
};
-static struct kobject *floppy_find(dev_t dev, int *part, void *data)
+static int ataflop_alloc_disk(unsigned int drive, unsigned int type)
{
- int drive = *part & 3;
- int type = *part >> 2;
+ struct gendisk *disk;
+ int ret;
+
+ disk = alloc_disk(1);
+ if (!disk)
+ return -ENOMEM;
+
+ disk->queue = blk_mq_init_queue(&unit[drive].tag_set);
+ if (IS_ERR(disk->queue)) {
+ ret = PTR_ERR(disk->queue);
+ disk->queue = NULL;
+ put_disk(disk);
+ return ret;
+ }
+
+ disk->major = FLOPPY_MAJOR;
+ disk->first_minor = drive + (type << 2);
+ sprintf(disk->disk_name, "fd%d", drive);
+ disk->fops = &floppy_fops;
+ disk->events = DISK_EVENT_MEDIA_CHANGE;
+ disk->private_data = &unit[drive];
+ set_capacity(disk, MAX_DISK_SIZE * 2);
+
+ unit[drive].disk[type] = disk;
+ return 0;
+}
+
+static DEFINE_MUTEX(ataflop_probe_lock);
+
+static void ataflop_probe(dev_t dev)
+{
+ int drive = MINOR(dev) & 3;
+ int type = MINOR(dev) >> 2;
+
if (drive >= FD_MAX_UNITS || type > NUM_DISK_MINORS)
- return NULL;
- *part = 0;
- return get_disk_and_module(unit[drive].disk);
+ return;
+ mutex_lock(&ataflop_probe_lock);
+ if (!unit[drive].disk[type]) {
+ if (ataflop_alloc_disk(drive, type) == 0)
+ add_disk(unit[drive].disk[type]);
+ }
+ mutex_unlock(&ataflop_probe_lock);
}
static int __init atari_floppy_init (void)
@@ -1981,23 +2021,26 @@ static int __init atari_floppy_init (void)
/* Amiga, Mac, ... don't have Atari-compatible floppy :-) */
return -ENODEV;
- if (register_blkdev(FLOPPY_MAJOR,"fd"))
- return -EBUSY;
+ mutex_lock(&ataflop_probe_lock);
+ ret = __register_blkdev(FLOPPY_MAJOR, "fd", ataflop_probe);
+ if (ret)
+ goto out_unlock;
for (i = 0; i < FD_MAX_UNITS; i++) {
- unit[i].disk = alloc_disk(1);
- if (!unit[i].disk) {
- ret = -ENOMEM;
+ memset(&unit[i].tag_set, 0, sizeof(unit[i].tag_set));
+ unit[i].tag_set.ops = &ataflop_mq_ops;
+ unit[i].tag_set.nr_hw_queues = 1;
+ unit[i].tag_set.nr_maps = 1;
+ unit[i].tag_set.queue_depth = 2;
+ unit[i].tag_set.numa_node = NUMA_NO_NODE;
+ unit[i].tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+ ret = blk_mq_alloc_tag_set(&unit[i].tag_set);
+ if (ret)
goto err;
- }
- unit[i].disk->queue = blk_mq_init_sq_queue(&unit[i].tag_set,
- &ataflop_mq_ops, 2,
- BLK_MQ_F_SHOULD_MERGE);
- if (IS_ERR(unit[i].disk->queue)) {
- put_disk(unit[i].disk);
- ret = PTR_ERR(unit[i].disk->queue);
- unit[i].disk->queue = NULL;
+ ret = ataflop_alloc_disk(i, 0);
+ if (ret) {
+ blk_mq_free_tag_set(&unit[i].tag_set);
goto err;
}
}
@@ -2027,19 +2070,9 @@ static int __init atari_floppy_init (void)
for (i = 0; i < FD_MAX_UNITS; i++) {
unit[i].track = -1;
unit[i].flags = 0;
- unit[i].disk->major = FLOPPY_MAJOR;
- unit[i].disk->first_minor = i;
- sprintf(unit[i].disk->disk_name, "fd%d", i);
- unit[i].disk->fops = &floppy_fops;
- unit[i].disk->events = DISK_EVENT_MEDIA_CHANGE;
- unit[i].disk->private_data = &unit[i];
- set_capacity(unit[i].disk, MAX_DISK_SIZE * 2);
- add_disk(unit[i].disk);
+ add_disk(unit[i].disk[0]);
}
- blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
- floppy_find, NULL, NULL);
-
printk(KERN_INFO "Atari floppy driver: max. %cD, %strack buffering\n",
DriveType == 0 ? 'D' : DriveType == 1 ? 'H' : 'E',
UseTrackbuffer ? "" : "no ");
@@ -2049,14 +2082,14 @@ static int __init atari_floppy_init (void)
err:
while (--i >= 0) {
- struct gendisk *disk = unit[i].disk;
-
- blk_cleanup_queue(disk->queue);
+ blk_cleanup_queue(unit[i].disk[0]->queue);
+ put_disk(unit[i].disk[0]);
blk_mq_free_tag_set(&unit[i].tag_set);
- put_disk(unit[i].disk);
}
unregister_blkdev(FLOPPY_MAJOR, "fd");
+out_unlock:
+ mutex_unlock(&ataflop_probe_lock);
return ret;
}
@@ -2101,13 +2134,17 @@ __setup("floppy=", atari_floppy_setup);
static void __exit atari_floppy_exit(void)
{
- int i;
- blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
+ int i, type;
+
for (i = 0; i < FD_MAX_UNITS; i++) {
- del_gendisk(unit[i].disk);
- blk_cleanup_queue(unit[i].disk->queue);
+ for (type = 0; type < NUM_DISK_MINORS; type++) {
+ if (!unit[i].disk[type])
+ continue;
+ del_gendisk(unit[i].disk[type]);
+ blk_cleanup_queue(unit[i].disk[type]->queue);
+ put_disk(unit[i].disk[type]);
+ }
blk_mq_free_tag_set(&unit[i].tag_set);
- put_disk(unit[i].disk);
}
unregister_blkdev(FLOPPY_MAJOR, "fd");
--
2.28.0
next prev parent reply other threads:[~2020-10-29 15:35 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-29 14:58 simplify gendisk lookup and remove struct block_device aliases v4 Christoph Hellwig
2020-10-29 14:58 ` [PATCH 01/18] block: cleanup del_gendisk a bit Christoph Hellwig
2020-10-29 14:58 ` [PATCH 02/18] block: open code kobj_map into in block/genhd.c Christoph Hellwig
2020-10-29 19:22 ` Greg Kroah-Hartman
2020-10-29 19:32 ` Christoph Hellwig
2020-10-30 10:40 ` Greg Kroah-Hartman
2020-10-30 10:49 ` Geert Uytterhoeven
2020-10-30 11:06 ` Greg Kroah-Hartman
2020-10-31 8:53 ` Christoph Hellwig
2020-10-29 14:58 ` [PATCH 03/18] block: split block_class_lock Christoph Hellwig
2020-10-29 14:58 ` [PATCH 04/18] block: rework requesting modules for unclaimed devices Christoph Hellwig
2020-10-29 14:58 ` [PATCH 05/18] block: add an optional probe callback to major_names Christoph Hellwig
2020-10-29 14:58 ` [PATCH 06/18] ide: remove ide_{,un}register_region Christoph Hellwig
2020-10-29 14:58 ` [PATCH 07/18] swim: don't call blk_register_region Christoph Hellwig
2020-10-29 14:58 ` [PATCH 08/18] sd: use __register_blkdev to avoid a modprobe for an unregistered dev_t Christoph Hellwig
2020-10-30 2:13 ` Martin K. Petersen
2020-10-29 14:58 ` [PATCH 09/18] brd: use __register_blkdev to allocate devices on demand Christoph Hellwig
2020-10-29 14:58 ` [PATCH 10/18] loop: " Christoph Hellwig
2020-10-29 14:58 ` [PATCH 11/18] md: " Christoph Hellwig
2020-10-29 14:58 ` [PATCH 12/18] ide: switch to __register_blkdev for command set probing Christoph Hellwig
2020-10-29 14:58 ` [PATCH 13/18] floppy: use a separate gendisk for each media format Christoph Hellwig
2020-10-29 14:58 ` [PATCH 14/18] amiflop: use separate gendisks for Amiga vs MS-DOS mode Christoph Hellwig
2020-10-29 14:58 ` Christoph Hellwig [this message]
2020-10-29 14:58 ` [PATCH 16/18] z2ram: reindent Christoph Hellwig
2020-10-29 14:58 ` [PATCH 17/18] z2ram: use separate gendisk for the different modes Christoph Hellwig
2020-10-30 0:11 ` [PATCH] z2ram: MODULE_LICENSE update and neatening Joe Perches
2020-10-30 1:01 ` James Bottomley
2020-10-30 1:23 ` Joe Perches
2020-10-29 14:58 ` [PATCH 18/18] block: switch gendisk lookup to a simple xarray Christoph Hellwig
2020-11-11 7:57 ` simplify gendisk lookup and remove struct block_device aliases v4 Christoph Hellwig
2020-11-11 16:17 ` Jens Axboe
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