[PATCH v5 00/18] Use block pr_ops in LIO

[PATCH v5 00/18] Use block pr_ops in LIO

[Mike Christie]

The patches in this thread allow us to use the block pr_ops with LIO's
target_core_iblock module to support cluster applications in VMs. They
were built over Linus's tree. They also apply over linux-next and
Martin's tree and Jens's trees. 
 
Currently, to use windows clustering or linux clustering (pacemaker +
cluster labs scsi fence agents) in VMs with LIO and vhost-scsi, you have
to use tcmu or pscsi or use a cluster aware FS/framework for the LIO pr
file. Setting up a cluster FS/framework is pain and waste when your real
backend device is already a distributed device, and pscsi and tcmu are
nice for specific use cases, but iblock gives you the best performance and
allows you to use stacked devices like dm-multipath. So these patches
allow iblock to work like pscsi/tcmu where they can pass a PR command to
the backend module. And then iblock will use the pr_ops to pass the PR
command to the real devices similar to what we do for unmap today.

The patches are separated in the following groups:
Patch 1 - 2:
- Add block layer callouts for reading reservations and rename reservation
  error code.
Patch 3 - 5:
- SCSI support for new callouts.
Patch 6:
- DM support for new callouts.
Patch 7 - 13:
- NVMe support for new callouts.
Patch 14 - 18:
- LIO support for new callouts.

This patchset has been tested with the libiscsi PGR ops and with window's
failover cluster verification test. Note that for scsi backend devices we
need this patchset:

https://lore.kernel.org/linux-scsi/20230123221046.125483-1-michael.christie@oracle.com/T/#m4834a643ffb5bac2529d65d40906d3cfbdd9b1b7

to handle UAs. To reduce the size of this patchset that's being done
separately to make reviewing easier. And to make merging easier this
patchset and the one above do not have any conflicts so can be merged
in different trees.

v5:
- Use []/struct_size with nvme reservation structs
- Add Keith's copywrite to pr.c
- Drop else in nvme_send_pr_command
- Fix PR_EXCLUSIVE_ACCESS_ALL_REGS use in block_pr_type_from_nvme

v4:
- Pass read_keys number of keys instead of array len
- Keep the switch use when converting between block and scsi/nvme PR
types. Drop default case so compiler spits out warning if in the future
a new value is added.
- Add helper for handling
nvme_send_ns_head_pr_command/nvme_send_ns_pr_command
- Use void * instead of u8* for passing data buffer.
- Rename status variable to rs.
- Have caller init buffer/structs instead of nvme/scsi callouts.
- Drop blk_status to err code.

v3:
- Fix patch subject formatting.
- Fix coding style.
- Rearrange patches so helpers are added with users to avoid compilation
errors.
- Move pr type conversion to array and add nvme_pr_type.
- Add Extended Data Structure control flag enum and use in code for checks.
- Move nvme pr code to new file.
- Add more info to patch subjects about why we need to add blk_status
to pr_ops.
- Use generic SCSI passthrough error handling interface.
- Fix checkpatch --strict errors. Note that I kept the existing coding
style that it complained about because it looked like it was the preferred
style for the code and I didn't want a mix and match.

v2:
- Drop BLK_STS_NEXUS rename changes. Will do separately.
- Add NVMe support.
- Fixed bug in target_core_iblock where a variable was not initialized
mentioned by Christoph.
- Fixed sd pr_ops UA handling issue found when running libiscsi PGR tests.
- Added patches to allow pr_ops to pass up a BLK_STS so we could return
a RESERVATION_CONFLICT status when a pr_ops callout fails.

[PATCH v5 01/18] block: Add PR callouts for read keys and reservation

[Mike Christie]

Add callouts for reading keys and reservations. This allows LIO to support
the READ_KEYS and READ_RESERVATION commands and will allow dm-multipath
to optimize it's error handling so it can check if it's getting an error
because there's an existing reservation or if we need to retry different
paths.

Note: This only initially adds the struct definitions in the kernel as I'm
not sure if we wanted to export the interface to userspace yet. read_keys
and read_reservation are exactly what dm-multipath and LIO need, but for a
userspace interface we may want something like SCSI's READ_FULL_STATUS and
NVMe's report reservation commands. Those are overkill for dm/LIO and
READ_FULL_STATUS is sometimes broken for SCSI devices.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/pr.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/include/linux/pr.h b/include/linux/pr.h
index 94ceec713afe..3003daec28a5 100644
--- a/include/linux/pr.h
+++ b/include/linux/pr.h
@@ -4,6 +4,18 @@
 
 #include <uapi/linux/pr.h>
 
+struct pr_keys {
+	u32	generation;
+	u32	num_keys;
+	u64	keys[];
+};
+
+struct pr_held_reservation {
+	u64		key;
+	u32		generation;
+	enum pr_type	type;
+};
+
 struct pr_ops {
 	int (*pr_register)(struct block_device *bdev, u64 old_key, u64 new_key,
 			u32 flags);
@@ -14,6 +26,19 @@ struct pr_ops {
 	int (*pr_preempt)(struct block_device *bdev, u64 old_key, u64 new_key,
 			enum pr_type type, bool abort);
 	int (*pr_clear)(struct block_device *bdev, u64 key);
+	/*
+	 * pr_read_keys - Read the registered keys and return them in the
+	 * pr_keys->keys array. The keys array will have been allocated at the
+	 * end of the pr_keys struct, and pr_keys->num_keys must be set to the
+	 * number of keys the array can hold. If there are more than can fit
+	 * in the array, success will still be returned and pr_keys->num_keys
+	 * will reflect the total number of keys the device contains, so the
+	 * caller can retry with a larger array.
+	 */
+	int (*pr_read_keys)(struct block_device *bdev,
+			struct pr_keys *keys_info);
+	int (*pr_read_reservation)(struct block_device *bdev,
+			struct pr_held_reservation *rsv);
 };
 
 #endif /* LINUX_PR_H */
-- 
2.25.1

[PATCH v5 02/18] block: Rename BLK_STS_NEXUS to BLK_STS_RESV_CONFLICT

[Mike Christie]

BLK_STS_NEXUS is used for NVMe/SCSI reservation conflicts and DASD's
locking feature which works similar to NVMe/SCSI reservations where a
host can get a lock on a device and when the lock is taken it will get
failures.

This patch renames BLK_STS_NEXUS so it better reflects this type of
use.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Acked-by: Stefan Haberland <sth@linux.ibm.com>
---
 block/blk-core.c          | 2 +-
 drivers/nvme/host/core.c  | 2 +-
 drivers/s390/block/dasd.c | 7 ++++++-
 drivers/scsi/scsi_lib.c   | 2 +-
 include/linux/blk_types.h | 4 ++--
 5 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 42926e6cb83c..c64db6fcb997 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -155,7 +155,7 @@ static const struct {
 	[BLK_STS_NOSPC]		= { -ENOSPC,	"critical space allocation" },
 	[BLK_STS_TRANSPORT]	= { -ENOLINK,	"recoverable transport" },
 	[BLK_STS_TARGET]	= { -EREMOTEIO,	"critical target" },
-	[BLK_STS_NEXUS]		= { -EBADE,	"critical nexus" },
+	[BLK_STS_RESV_CONFLICT]	= { -EBADE,	"reservation conflict" },
 	[BLK_STS_MEDIUM]	= { -ENODATA,	"critical medium" },
 	[BLK_STS_PROTECTION]	= { -EILSEQ,	"protection" },
 	[BLK_STS_RESOURCE]	= { -ENOMEM,	"kernel resource" },
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d4be525f8100..d400175c312d 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -279,7 +279,7 @@ static blk_status_t nvme_error_status(u16 status)
 	case NVME_SC_INVALID_PI:
 		return BLK_STS_PROTECTION;
 	case NVME_SC_RESERVATION_CONFLICT:
-		return BLK_STS_NEXUS;
+		return BLK_STS_RESV_CONFLICT;
 	case NVME_SC_HOST_PATH_ERROR:
 		return BLK_STS_TRANSPORT;
 	case NVME_SC_ZONE_TOO_MANY_ACTIVE:
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index a9c2a8d76c45..ca0df87fa8f4 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2723,7 +2723,12 @@ static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
 	else if (status == 0) {
 		switch (cqr->intrc) {
 		case -EPERM:
-			error = BLK_STS_NEXUS;
+			/*
+			 * DASD doesn't implement SCSI/NVMe reservations, but it
+			 * implements a locking scheme similar to them. We
+			 * return this error when we no longer have the lock.
+			 */
+			error = BLK_STS_RESV_CONFLICT;
 			break;
 		case -ENOLINK:
 			error = BLK_STS_TRANSPORT;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b7c569a42aa4..e1468483ac7e 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -599,7 +599,7 @@ static blk_status_t scsi_result_to_blk_status(int result)
 	case SCSIML_STAT_OK:
 		break;
 	case SCSIML_STAT_RESV_CONFLICT:
-		return BLK_STS_NEXUS;
+		return BLK_STS_RESV_CONFLICT;
 	case SCSIML_STAT_NOSPC:
 		return BLK_STS_NOSPC;
 	case SCSIML_STAT_MED_ERROR:
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 99be590f952f..2b2452086a2f 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -96,7 +96,7 @@ typedef u16 blk_short_t;
 #define BLK_STS_NOSPC		((__force blk_status_t)3)
 #define BLK_STS_TRANSPORT	((__force blk_status_t)4)
 #define BLK_STS_TARGET		((__force blk_status_t)5)
-#define BLK_STS_NEXUS		((__force blk_status_t)6)
+#define BLK_STS_RESV_CONFLICT	((__force blk_status_t)6)
 #define BLK_STS_MEDIUM		((__force blk_status_t)7)
 #define BLK_STS_PROTECTION	((__force blk_status_t)8)
 #define BLK_STS_RESOURCE	((__force blk_status_t)9)
@@ -184,7 +184,7 @@ static inline bool blk_path_error(blk_status_t error)
 	case BLK_STS_NOTSUPP:
 	case BLK_STS_NOSPC:
 	case BLK_STS_TARGET:
-	case BLK_STS_NEXUS:
+	case BLK_STS_RESV_CONFLICT:
 	case BLK_STS_MEDIUM:
 	case BLK_STS_PROTECTION:
 		return false;
-- 
2.25.1

[PATCH v5 03/18] scsi: Rename sd_pr_command

[Mike Christie]

Rename sd_pr_command to sd_pr_out_command to match a
sd_pr_in_command helper added in the next patches.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
---
 drivers/scsi/sd.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 4bb87043e6db..00b9b6145fbc 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1742,7 +1742,7 @@ static int sd_scsi_to_pr_err(struct scsi_sense_hdr *sshdr, int result)
 	}
 }
 
-static int sd_pr_command(struct block_device *bdev, u8 sa,
+static int sd_pr_out_command(struct block_device *bdev, u8 sa,
 		u64 key, u64 sa_key, u8 type, u8 flags)
 {
 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
@@ -1785,7 +1785,7 @@ static int sd_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
 {
 	if (flags & ~PR_FL_IGNORE_KEY)
 		return -EOPNOTSUPP;
-	return sd_pr_command(bdev, (flags & PR_FL_IGNORE_KEY) ? 0x06 : 0x00,
+	return sd_pr_out_command(bdev, (flags & PR_FL_IGNORE_KEY) ? 0x06 : 0x00,
 			old_key, new_key, 0,
 			(1 << 0) /* APTPL */);
 }
@@ -1795,24 +1795,24 @@ static int sd_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
 {
 	if (flags)
 		return -EOPNOTSUPP;
-	return sd_pr_command(bdev, 0x01, key, 0, sd_pr_type(type), 0);
+	return sd_pr_out_command(bdev, 0x01, key, 0, sd_pr_type(type), 0);
 }
 
 static int sd_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
 {
-	return sd_pr_command(bdev, 0x02, key, 0, sd_pr_type(type), 0);
+	return sd_pr_out_command(bdev, 0x02, key, 0, sd_pr_type(type), 0);
 }
 
 static int sd_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
 		enum pr_type type, bool abort)
 {
-	return sd_pr_command(bdev, abort ? 0x05 : 0x04, old_key, new_key,
+	return sd_pr_out_command(bdev, abort ? 0x05 : 0x04, old_key, new_key,
 			     sd_pr_type(type), 0);
 }
 
 static int sd_pr_clear(struct block_device *bdev, u64 key)
 {
-	return sd_pr_command(bdev, 0x03, key, 0, 0, 0);
+	return sd_pr_out_command(bdev, 0x03, key, 0, 0, 0);
 }
 
 static const struct pr_ops sd_pr_ops = {
-- 
2.25.1

[PATCH v5 04/18] scsi: Move sd_pr_type to header to share

[Mike Christie]

LIO is going to want to do the same block to/from SCSI pr types as sd.c
so this moves the sd_pr_type helper to a new file. The next patch will
then also add a helper to go from the SCSI value to the block one for use
with PERSISTENT_RESERVE_IN commands.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
---
 drivers/scsi/sd.c            | 33 ++++++++-------------------------
 include/scsi/scsi_block_pr.h | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 25 deletions(-)
 create mode 100644 include/scsi/scsi_block_pr.h

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 00b9b6145fbc..7ebf59114da1 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -67,6 +67,7 @@
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_ioctl.h>
 #include <scsi/scsicam.h>
+#include <scsi/scsi_block_pr.h>
 
 #include "sd.h"
 #include "scsi_priv.h"
@@ -1692,26 +1693,6 @@ static int sd_get_unique_id(struct gendisk *disk, u8 id[16],
 	return ret;
 }
 
-static char sd_pr_type(enum pr_type type)
-{
-	switch (type) {
-	case PR_WRITE_EXCLUSIVE:
-		return 0x01;
-	case PR_EXCLUSIVE_ACCESS:
-		return 0x03;
-	case PR_WRITE_EXCLUSIVE_REG_ONLY:
-		return 0x05;
-	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
-		return 0x06;
-	case PR_WRITE_EXCLUSIVE_ALL_REGS:
-		return 0x07;
-	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
-		return 0x08;
-	default:
-		return 0;
-	}
-};
-
 static int sd_scsi_to_pr_err(struct scsi_sense_hdr *sshdr, int result)
 {
 	switch (host_byte(result)) {
@@ -1742,8 +1723,8 @@ static int sd_scsi_to_pr_err(struct scsi_sense_hdr *sshdr, int result)
 	}
 }
 
-static int sd_pr_out_command(struct block_device *bdev, u8 sa,
-		u64 key, u64 sa_key, u8 type, u8 flags)
+static int sd_pr_out_command(struct block_device *bdev, u8 sa, u64 key,
+			     u64 sa_key, enum scsi_pr_type type, u8 flags)
 {
 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
 	struct scsi_device *sdev = sdkp->device;
@@ -1795,19 +1776,21 @@ static int sd_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
 {
 	if (flags)
 		return -EOPNOTSUPP;
-	return sd_pr_out_command(bdev, 0x01, key, 0, sd_pr_type(type), 0);
+	return sd_pr_out_command(bdev, 0x01, key, 0,
+				 block_pr_type_to_scsi(type), 0);
 }
 
 static int sd_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
 {
-	return sd_pr_out_command(bdev, 0x02, key, 0, sd_pr_type(type), 0);
+	return sd_pr_out_command(bdev, 0x02, key, 0,
+				 block_pr_type_to_scsi(type), 0);
 }
 
 static int sd_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
 		enum pr_type type, bool abort)
 {
 	return sd_pr_out_command(bdev, abort ? 0x05 : 0x04, old_key, new_key,
-			     sd_pr_type(type), 0);
+				 block_pr_type_to_scsi(type), 0);
 }
 
 static int sd_pr_clear(struct block_device *bdev, u64 key)
diff --git a/include/scsi/scsi_block_pr.h b/include/scsi/scsi_block_pr.h
new file mode 100644
index 000000000000..44766d7a81d8
--- /dev/null
+++ b/include/scsi/scsi_block_pr.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SCSI_BLOCK_PR_H
+#define _SCSI_BLOCK_PR_H
+
+#include <uapi/linux/pr.h>
+
+enum scsi_pr_type {
+	SCSI_PR_WRITE_EXCLUSIVE			= 0x01,
+	SCSI_PR_EXCLUSIVE_ACCESS		= 0x03,
+	SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY	= 0x05,
+	SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY	= 0x06,
+	SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS	= 0x07,
+	SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS	= 0x08,
+};
+
+static inline enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
+{
+	switch (type) {
+	case PR_WRITE_EXCLUSIVE:
+		return SCSI_PR_WRITE_EXCLUSIVE;
+	case PR_EXCLUSIVE_ACCESS:
+		return SCSI_PR_EXCLUSIVE_ACCESS;
+	case PR_WRITE_EXCLUSIVE_REG_ONLY:
+		return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
+	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
+		return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
+	case PR_WRITE_EXCLUSIVE_ALL_REGS:
+		return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
+	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
+		return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
+	}
+
+	return 0;
+}
+
+#endif
-- 
2.25.1

[PATCH v5 05/18] scsi: Add support for block PR read keys/reservation

[Mike Christie]

This adds support in sd.c for the block PR read keys and read reservation
callouts, so upper layers like LIO can get the PR info that's been setup
using the existing pr callouts and return it to initiators.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/sd.c            | 91 ++++++++++++++++++++++++++++++++++++
 include/scsi/scsi_block_pr.h | 20 ++++++++
 include/scsi/scsi_proto.h    |  5 ++
 3 files changed, 116 insertions(+)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 7ebf59114da1..2895a8f1bbfa 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1723,6 +1723,95 @@ static int sd_scsi_to_pr_err(struct scsi_sense_hdr *sshdr, int result)
 	}
 }
 
+static int sd_pr_in_command(struct block_device *bdev, u8 sa,
+			    unsigned char *data, int data_len)
+{
+	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
+	struct scsi_device *sdev = sdkp->device;
+	struct scsi_sense_hdr sshdr;
+	u8 cmd[10] = { PERSISTENT_RESERVE_IN, sa };
+	const struct scsi_exec_args exec_args = {
+		.sshdr = &sshdr,
+	};
+	int result;
+
+	put_unaligned_be16(data_len, &cmd[7]);
+
+	result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, data, data_len,
+				   SD_TIMEOUT, sdkp->max_retries, &exec_args);
+	if (scsi_status_is_check_condition(result) &&
+	    scsi_sense_valid(&sshdr)) {
+		sdev_printk(KERN_INFO, sdev, "PR command failed: %d\n", result);
+		scsi_print_sense_hdr(sdev, NULL, &sshdr);
+	}
+
+	if (result <= 0)
+		return result;
+
+	return sd_scsi_to_pr_err(&sshdr, result);
+}
+
+static int sd_pr_read_keys(struct block_device *bdev, struct pr_keys *keys_info)
+{
+	int result, i, data_offset, num_copy_keys;
+	u32 num_keys = keys_info->num_keys;
+	int data_len = num_keys * 8 + 8;
+	u8 *data;
+
+	data = kzalloc(data_len, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	result = sd_pr_in_command(bdev, READ_KEYS, data, data_len);
+	if (result)
+		goto free_data;
+
+	keys_info->generation = get_unaligned_be32(&data[0]);
+	keys_info->num_keys = get_unaligned_be32(&data[4]) / 8;
+
+	data_offset = 8;
+	num_copy_keys = min(num_keys, keys_info->num_keys);
+
+	for (i = 0; i < num_copy_keys; i++) {
+		keys_info->keys[i] = get_unaligned_be64(&data[data_offset]);
+		data_offset += 8;
+	}
+
+free_data:
+	kfree(data);
+	return result;
+}
+
+static int sd_pr_read_reservation(struct block_device *bdev,
+				  struct pr_held_reservation *rsv)
+{
+	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
+	struct scsi_device *sdev = sdkp->device;
+	u8 data[24] = { };
+	int result, len;
+
+	result = sd_pr_in_command(bdev, READ_RESERVATION, data, sizeof(data));
+	if (result)
+		return result;
+
+	len = get_unaligned_be32(&data[4]);
+	if (!len)
+		return 0;
+
+	/* Make sure we have at least the key and type */
+	if (len < 14) {
+		sdev_printk(KERN_INFO, sdev,
+			    "READ RESERVATION failed due to short return buffer of %d bytes\n",
+			    len);
+		return -EINVAL;
+	}
+
+	rsv->generation = get_unaligned_be32(&data[0]);
+	rsv->key = get_unaligned_be64(&data[8]);
+	rsv->type = scsi_pr_type_to_block(data[21] & 0x0f);
+	return 0;
+}
+
 static int sd_pr_out_command(struct block_device *bdev, u8 sa, u64 key,
 			     u64 sa_key, enum scsi_pr_type type, u8 flags)
 {
@@ -1804,6 +1893,8 @@ static const struct pr_ops sd_pr_ops = {
 	.pr_release	= sd_pr_release,
 	.pr_preempt	= sd_pr_preempt,
 	.pr_clear	= sd_pr_clear,
+	.pr_read_keys	= sd_pr_read_keys,
+	.pr_read_reservation = sd_pr_read_reservation,
 };
 
 static void scsi_disk_free_disk(struct gendisk *disk)
diff --git a/include/scsi/scsi_block_pr.h b/include/scsi/scsi_block_pr.h
index 44766d7a81d8..9695cda4e9ce 100644
--- a/include/scsi/scsi_block_pr.h
+++ b/include/scsi/scsi_block_pr.h
@@ -33,4 +33,24 @@ static inline enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
 	return 0;
 }
 
+static inline enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type)
+{
+	switch (type) {
+	case SCSI_PR_WRITE_EXCLUSIVE:
+		return PR_WRITE_EXCLUSIVE;
+	case SCSI_PR_EXCLUSIVE_ACCESS:
+		return PR_EXCLUSIVE_ACCESS;
+	case SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY:
+		return PR_WRITE_EXCLUSIVE_REG_ONLY;
+	case SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY:
+		return PR_EXCLUSIVE_ACCESS_REG_ONLY;
+	case SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS:
+		return PR_WRITE_EXCLUSIVE_ALL_REGS;
+	case SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS:
+		return PR_EXCLUSIVE_ACCESS_ALL_REGS;
+	}
+
+	return 0;
+}
+
 #endif
diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h
index fbe5bdfe4d6e..07d65c1f59db 100644
--- a/include/scsi/scsi_proto.h
+++ b/include/scsi/scsi_proto.h
@@ -151,6 +151,11 @@
 #define ZO_FINISH_ZONE	      0x02
 #define ZO_OPEN_ZONE	      0x03
 #define ZO_RESET_WRITE_POINTER 0x04
+/* values for PR in service action */
+#define READ_KEYS             0x00
+#define READ_RESERVATION      0x01
+#define REPORT_CAPABILITES    0x02
+#define READ_FULL_STATUS      0x03
 /* values for variable length command */
 #define XDREAD_32	      0x03
 #define XDWRITE_32	      0x04
-- 
2.25.1

[PATCH v5 06/18] dm: Add support for block PR read keys/reservation

[Mike Christie]

This adds support in dm for the block PR read keys and read reservation
callouts.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/md/dm.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f5cc330bb549..51e34e1a16bb 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -3114,6 +3114,8 @@ struct dm_pr {
 	bool	fail_early;
 	int	ret;
 	enum pr_type type;
+	struct pr_keys *read_keys;
+	struct pr_held_reservation *rsv;
 };
 
 static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
@@ -3346,12 +3348,79 @@ static int dm_pr_clear(struct block_device *bdev, u64 key)
 	return r;
 }
 
+static int __dm_pr_read_keys(struct dm_target *ti, struct dm_dev *dev,
+			     sector_t start, sector_t len, void *data)
+{
+	struct dm_pr *pr = data;
+	const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
+
+	if (!ops || !ops->pr_read_keys) {
+		pr->ret = -EOPNOTSUPP;
+		return -1;
+	}
+
+	pr->ret = ops->pr_read_keys(dev->bdev, pr->read_keys);
+	if (!pr->ret)
+		return -1;
+
+	return 0;
+}
+
+static int dm_pr_read_keys(struct block_device *bdev, struct pr_keys *keys)
+{
+	struct dm_pr pr = {
+		.read_keys = keys,
+	};
+	int ret;
+
+	ret = dm_call_pr(bdev, __dm_pr_read_keys, &pr);
+	if (ret)
+		return ret;
+
+	return pr.ret;
+}
+
+static int __dm_pr_read_reservation(struct dm_target *ti, struct dm_dev *dev,
+				    sector_t start, sector_t len, void *data)
+{
+	struct dm_pr *pr = data;
+	const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
+
+	if (!ops || !ops->pr_read_reservation) {
+		pr->ret = -EOPNOTSUPP;
+		return -1;
+	}
+
+	pr->ret = ops->pr_read_reservation(dev->bdev, pr->rsv);
+	if (!pr->ret)
+		return -1;
+
+	return 0;
+}
+
+static int dm_pr_read_reservation(struct block_device *bdev,
+				  struct pr_held_reservation *rsv)
+{
+	struct dm_pr pr = {
+		.rsv = rsv,
+	};
+	int ret;
+
+	ret = dm_call_pr(bdev, __dm_pr_read_reservation, &pr);
+	if (ret)
+		return ret;
+
+	return pr.ret;
+}
+
 static const struct pr_ops dm_pr_ops = {
 	.pr_register	= dm_pr_register,
 	.pr_reserve	= dm_pr_reserve,
 	.pr_release	= dm_pr_release,
 	.pr_preempt	= dm_pr_preempt,
 	.pr_clear	= dm_pr_clear,
+	.pr_read_keys	= dm_pr_read_keys,
+	.pr_read_reservation = dm_pr_read_reservation,
 };
 
 static const struct block_device_operations dm_blk_dops = {
-- 
2.25.1

[PATCH v5 07/18] nvme: Fix reservation status related structs

[Mike Christie]

This fixes the following issues with the reservation status structs:

1. resv10 is bytes 23:10 so it should be 14 bytes.
2. regctl_ds only supports 64 bit host IDs.

These are not currently used, but will be in this patchset which adds
support for the reservation report command.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 include/linux/nvme.h | 38 ++++++++++++++++++++++++++++++--------
 1 file changed, 30 insertions(+), 8 deletions(-)

diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 779507ac750b..83704fc04a94 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -759,20 +759,42 @@ enum {
 	NVME_LBART_ATTRIB_HIDE	= 1 << 1,
 };
 
+struct nvme_registered_ctrl {
+	__le16	cntlid;
+	__u8	rcsts;
+	__u8	rsvd3[5];
+	__le64	hostid;
+	__le64	rkey;
+};
+
 struct nvme_reservation_status {
 	__le32	gen;
 	__u8	rtype;
 	__u8	regctl[2];
 	__u8	resv5[2];
 	__u8	ptpls;
-	__u8	resv10[13];
-	struct {
-		__le16	cntlid;
-		__u8	rcsts;
-		__u8	resv3[5];
-		__le64	hostid;
-		__le64	rkey;
-	} regctl_ds[];
+	__u8	resv10[14];
+	struct nvme_registered_ctrl regctl_ds[];
+};
+
+struct nvme_registered_ctrl_ext {
+	__le16	cntlid;
+	__u8	rcsts;
+	__u8	rsvd3[5];
+	__le64	rkey;
+	__u8	hostid[16];
+	__u8	rsvd32[32];
+};
+
+struct nvme_reservation_status_ext {
+	__le32	gen;
+	__u8	rtype;
+	__u8	regctl[2];
+	__u8	resv5[2];
+	__u8	ptpls;
+	__u8	resv10[14];
+	__u8	rsvd24[40];
+	struct nvme_registered_ctrl_ext regctl_eds[];
 };
 
 enum nvme_async_event_type {
-- 
2.25.1

[PATCH v5 08/18] nvme: Don't hardcode the data len for pr commands

[Mike Christie]

Reservation Report support needs to pass in a variable sized buffer, so
this patch has the pr command helpers take a data length argument.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
---
 drivers/nvme/host/core.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d400175c312d..48a22c3aff15 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2082,7 +2082,7 @@ static char nvme_pr_type(enum pr_type type)
 }
 
 static int nvme_send_ns_head_pr_command(struct block_device *bdev,
-		struct nvme_command *c, u8 data[16])
+		struct nvme_command *c, u8 *data, unsigned int data_len)
 {
 	struct nvme_ns_head *head = bdev->bd_disk->private_data;
 	int srcu_idx = srcu_read_lock(&head->srcu);
@@ -2091,17 +2091,17 @@ static int nvme_send_ns_head_pr_command(struct block_device *bdev,
 
 	if (ns) {
 		c->common.nsid = cpu_to_le32(ns->head->ns_id);
-		ret = nvme_submit_sync_cmd(ns->queue, c, data, 16);
+		ret = nvme_submit_sync_cmd(ns->queue, c, data, data_len);
 	}
 	srcu_read_unlock(&head->srcu, srcu_idx);
 	return ret;
 }
 	
 static int nvme_send_ns_pr_command(struct nvme_ns *ns, struct nvme_command *c,
-		u8 data[16])
+		u8 *data, unsigned int data_len)
 {
 	c->common.nsid = cpu_to_le32(ns->head->ns_id);
-	return nvme_submit_sync_cmd(ns->queue, c, data, 16);
+	return nvme_submit_sync_cmd(ns->queue, c, data, data_len);
 }
 
 static int nvme_sc_to_pr_err(int nvme_sc)
@@ -2141,10 +2141,11 @@ static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
 
 	if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
 	    bdev->bd_disk->fops == &nvme_ns_head_ops)
-		ret = nvme_send_ns_head_pr_command(bdev, &c, data);
+		ret = nvme_send_ns_head_pr_command(bdev, &c, data,
+						   sizeof(data));
 	else
 		ret = nvme_send_ns_pr_command(bdev->bd_disk->private_data, &c,
-					      data);
+					      data, sizeof(data));
 	if (ret < 0)
 		return ret;
 
-- 
2.25.1

[PATCH v5 09/18] nvme: Move pr code to it's own file

[Mike Christie]

This patch moves the pr code to it's own file because I'm going to be
adding more functions and core.c is getting bigger.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
---
 drivers/nvme/host/Makefile |   2 +-
 drivers/nvme/host/core.c   | 148 ----------------------------------
 drivers/nvme/host/nvme.h   |   2 +
 drivers/nvme/host/pr.c     | 158 +++++++++++++++++++++++++++++++++++++
 4 files changed, 161 insertions(+), 149 deletions(-)
 create mode 100644 drivers/nvme/host/pr.c

diff --git a/drivers/nvme/host/Makefile b/drivers/nvme/host/Makefile
index e27202d22c7d..06c18a65da99 100644
--- a/drivers/nvme/host/Makefile
+++ b/drivers/nvme/host/Makefile
@@ -10,7 +10,7 @@ obj-$(CONFIG_NVME_FC)			+= nvme-fc.o
 obj-$(CONFIG_NVME_TCP)			+= nvme-tcp.o
 obj-$(CONFIG_NVME_APPLE)		+= nvme-apple.o
 
-nvme-core-y				+= core.o ioctl.o
+nvme-core-y				+= core.o ioctl.o pr.o
 nvme-core-$(CONFIG_NVME_VERBOSE_ERRORS)	+= constants.o
 nvme-core-$(CONFIG_TRACING)		+= trace.o
 nvme-core-$(CONFIG_NVME_MULTIPATH)	+= multipath.o
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 48a22c3aff15..16d4564967bc 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2061,154 +2061,6 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
 	}
 }
 
-static char nvme_pr_type(enum pr_type type)
-{
-	switch (type) {
-	case PR_WRITE_EXCLUSIVE:
-		return 1;
-	case PR_EXCLUSIVE_ACCESS:
-		return 2;
-	case PR_WRITE_EXCLUSIVE_REG_ONLY:
-		return 3;
-	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
-		return 4;
-	case PR_WRITE_EXCLUSIVE_ALL_REGS:
-		return 5;
-	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
-		return 6;
-	default:
-		return 0;
-	}
-}
-
-static int nvme_send_ns_head_pr_command(struct block_device *bdev,
-		struct nvme_command *c, u8 *data, unsigned int data_len)
-{
-	struct nvme_ns_head *head = bdev->bd_disk->private_data;
-	int srcu_idx = srcu_read_lock(&head->srcu);
-	struct nvme_ns *ns = nvme_find_path(head);
-	int ret = -EWOULDBLOCK;
-
-	if (ns) {
-		c->common.nsid = cpu_to_le32(ns->head->ns_id);
-		ret = nvme_submit_sync_cmd(ns->queue, c, data, data_len);
-	}
-	srcu_read_unlock(&head->srcu, srcu_idx);
-	return ret;
-}
-	
-static int nvme_send_ns_pr_command(struct nvme_ns *ns, struct nvme_command *c,
-		u8 *data, unsigned int data_len)
-{
-	c->common.nsid = cpu_to_le32(ns->head->ns_id);
-	return nvme_submit_sync_cmd(ns->queue, c, data, data_len);
-}
-
-static int nvme_sc_to_pr_err(int nvme_sc)
-{
-	if (nvme_is_path_error(nvme_sc))
-		return PR_STS_PATH_FAILED;
-
-	switch (nvme_sc) {
-	case NVME_SC_SUCCESS:
-		return PR_STS_SUCCESS;
-	case NVME_SC_RESERVATION_CONFLICT:
-		return PR_STS_RESERVATION_CONFLICT;
-	case NVME_SC_ONCS_NOT_SUPPORTED:
-		return -EOPNOTSUPP;
-	case NVME_SC_BAD_ATTRIBUTES:
-	case NVME_SC_INVALID_OPCODE:
-	case NVME_SC_INVALID_FIELD:
-	case NVME_SC_INVALID_NS:
-		return -EINVAL;
-	default:
-		return PR_STS_IOERR;
-	}
-}
-
-static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
-				u64 key, u64 sa_key, u8 op)
-{
-	struct nvme_command c = { };
-	u8 data[16] = { 0, };
-	int ret;
-
-	put_unaligned_le64(key, &data[0]);
-	put_unaligned_le64(sa_key, &data[8]);
-
-	c.common.opcode = op;
-	c.common.cdw10 = cpu_to_le32(cdw10);
-
-	if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
-	    bdev->bd_disk->fops == &nvme_ns_head_ops)
-		ret = nvme_send_ns_head_pr_command(bdev, &c, data,
-						   sizeof(data));
-	else
-		ret = nvme_send_ns_pr_command(bdev->bd_disk->private_data, &c,
-					      data, sizeof(data));
-	if (ret < 0)
-		return ret;
-
-	return nvme_sc_to_pr_err(ret);
-}
-
-static int nvme_pr_register(struct block_device *bdev, u64 old,
-		u64 new, unsigned flags)
-{
-	u32 cdw10;
-
-	if (flags & ~PR_FL_IGNORE_KEY)
-		return -EOPNOTSUPP;
-
-	cdw10 = old ? 2 : 0;
-	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
-	cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
-	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
-}
-
-static int nvme_pr_reserve(struct block_device *bdev, u64 key,
-		enum pr_type type, unsigned flags)
-{
-	u32 cdw10;
-
-	if (flags & ~PR_FL_IGNORE_KEY)
-		return -EOPNOTSUPP;
-
-	cdw10 = nvme_pr_type(type) << 8;
-	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
-	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
-}
-
-static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
-		enum pr_type type, bool abort)
-{
-	u32 cdw10 = nvme_pr_type(type) << 8 | (abort ? 2 : 1);
-
-	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
-}
-
-static int nvme_pr_clear(struct block_device *bdev, u64 key)
-{
-	u32 cdw10 = 1 | (key ? 0 : 1 << 3);
-
-	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
-}
-
-static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
-{
-	u32 cdw10 = nvme_pr_type(type) << 8 | (key ? 0 : 1 << 3);
-
-	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
-}
-
-const struct pr_ops nvme_pr_ops = {
-	.pr_register	= nvme_pr_register,
-	.pr_reserve	= nvme_pr_reserve,
-	.pr_release	= nvme_pr_release,
-	.pr_preempt	= nvme_pr_preempt,
-	.pr_clear	= nvme_pr_clear,
-};
-
 #ifdef CONFIG_BLK_SED_OPAL
 static int nvme_sec_submit(void *data, u16 spsp, u8 secp, void *buffer, size_t len,
 		bool send)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index bf46f122e9e1..c0762346b441 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -19,6 +19,8 @@
 
 #include <trace/events/block.h>
 
+extern const struct pr_ops nvme_pr_ops;
+
 extern unsigned int nvme_io_timeout;
 #define NVME_IO_TIMEOUT	(nvme_io_timeout * HZ)
 
diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
new file mode 100644
index 000000000000..ca7a8d531a23
--- /dev/null
+++ b/drivers/nvme/host/pr.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2015 Intel Corporation
+ *	Keith Busch <kbusch@kernel.org>
+ */
+#include <linux/blkdev.h>
+#include <linux/pr.h>
+#include <asm/unaligned.h>
+
+#include "nvme.h"
+
+static char nvme_pr_type(enum pr_type type)
+{
+	switch (type) {
+	case PR_WRITE_EXCLUSIVE:
+		return 1;
+	case PR_EXCLUSIVE_ACCESS:
+		return 2;
+	case PR_WRITE_EXCLUSIVE_REG_ONLY:
+		return 3;
+	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
+		return 4;
+	case PR_WRITE_EXCLUSIVE_ALL_REGS:
+		return 5;
+	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
+		return 6;
+	default:
+		return 0;
+	}
+}
+
+static int nvme_send_ns_head_pr_command(struct block_device *bdev,
+		struct nvme_command *c, u8 *data, unsigned int data_len)
+{
+	struct nvme_ns_head *head = bdev->bd_disk->private_data;
+	int srcu_idx = srcu_read_lock(&head->srcu);
+	struct nvme_ns *ns = nvme_find_path(head);
+	int ret = -EWOULDBLOCK;
+
+	if (ns) {
+		c->common.nsid = cpu_to_le32(ns->head->ns_id);
+		ret = nvme_submit_sync_cmd(ns->queue, c, data, data_len);
+	}
+	srcu_read_unlock(&head->srcu, srcu_idx);
+	return ret;
+}
+
+static int nvme_send_ns_pr_command(struct nvme_ns *ns, struct nvme_command *c,
+		u8 *data, unsigned int data_len)
+{
+	c->common.nsid = cpu_to_le32(ns->head->ns_id);
+	return nvme_submit_sync_cmd(ns->queue, c, data, data_len);
+}
+
+static int nvme_sc_to_pr_err(int nvme_sc)
+{
+	if (nvme_is_path_error(nvme_sc))
+		return PR_STS_PATH_FAILED;
+
+	switch (nvme_sc) {
+	case NVME_SC_SUCCESS:
+		return PR_STS_SUCCESS;
+	case NVME_SC_RESERVATION_CONFLICT:
+		return PR_STS_RESERVATION_CONFLICT;
+	case NVME_SC_ONCS_NOT_SUPPORTED:
+		return -EOPNOTSUPP;
+	case NVME_SC_BAD_ATTRIBUTES:
+	case NVME_SC_INVALID_OPCODE:
+	case NVME_SC_INVALID_FIELD:
+	case NVME_SC_INVALID_NS:
+		return -EINVAL;
+	default:
+		return PR_STS_IOERR;
+	}
+}
+
+static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
+				u64 key, u64 sa_key, u8 op)
+{
+	struct nvme_command c = { };
+	u8 data[16] = { 0, };
+	int ret;
+
+	put_unaligned_le64(key, &data[0]);
+	put_unaligned_le64(sa_key, &data[8]);
+
+	c.common.opcode = op;
+	c.common.cdw10 = cpu_to_le32(cdw10);
+
+	if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
+	    bdev->bd_disk->fops == &nvme_ns_head_ops)
+		ret = nvme_send_ns_head_pr_command(bdev, &c, data,
+						   sizeof(data));
+	else
+		ret = nvme_send_ns_pr_command(bdev->bd_disk->private_data, &c,
+					      data, sizeof(data));
+	if (ret < 0)
+		return ret;
+
+	return nvme_sc_to_pr_err(ret);
+}
+
+static int nvme_pr_register(struct block_device *bdev, u64 old,
+		u64 new, unsigned flags)
+{
+	u32 cdw10;
+
+	if (flags & ~PR_FL_IGNORE_KEY)
+		return -EOPNOTSUPP;
+
+	cdw10 = old ? 2 : 0;
+	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
+	cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
+	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
+}
+
+static int nvme_pr_reserve(struct block_device *bdev, u64 key,
+		enum pr_type type, unsigned flags)
+{
+	u32 cdw10;
+
+	if (flags & ~PR_FL_IGNORE_KEY)
+		return -EOPNOTSUPP;
+
+	cdw10 = nvme_pr_type(type) << 8;
+	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
+}
+
+static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
+		enum pr_type type, bool abort)
+{
+	u32 cdw10 = nvme_pr_type(type) << 8 | (abort ? 2 : 1);
+
+	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
+}
+
+static int nvme_pr_clear(struct block_device *bdev, u64 key)
+{
+	u32 cdw10 = 1 | (key ? 0 : 1 << 3);
+
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
+}
+
+static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
+{
+	u32 cdw10 = nvme_pr_type(type) << 8 | (key ? 0 : 1 << 3);
+
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
+}
+
+const struct pr_ops nvme_pr_ops = {
+	.pr_register	= nvme_pr_register,
+	.pr_reserve	= nvme_pr_reserve,
+	.pr_release	= nvme_pr_release,
+	.pr_preempt	= nvme_pr_preempt,
+	.pr_clear	= nvme_pr_clear,
+};
-- 
2.25.1

[PATCH v5 10/18] nvme: Add helper to send pr command

[Mike Christie]

Move the code that checks for multipath support and sends the pr command
to a new helper so it can be used by the reservation report support added
in the next patches.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/pr.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
index ca7a8d531a23..cd93d2e5b340 100644
--- a/drivers/nvme/host/pr.c
+++ b/drivers/nvme/host/pr.c
@@ -30,7 +30,7 @@ static char nvme_pr_type(enum pr_type type)
 }
 
 static int nvme_send_ns_head_pr_command(struct block_device *bdev,
-		struct nvme_command *c, u8 *data, unsigned int data_len)
+		struct nvme_command *c, void *data, unsigned int data_len)
 {
 	struct nvme_ns_head *head = bdev->bd_disk->private_data;
 	int srcu_idx = srcu_read_lock(&head->srcu);
@@ -46,7 +46,7 @@ static int nvme_send_ns_head_pr_command(struct block_device *bdev,
 }
 
 static int nvme_send_ns_pr_command(struct nvme_ns *ns, struct nvme_command *c,
-		u8 *data, unsigned int data_len)
+		void *data, unsigned int data_len)
 {
 	c->common.nsid = cpu_to_le32(ns->head->ns_id);
 	return nvme_submit_sync_cmd(ns->queue, c, data, data_len);
@@ -74,6 +74,17 @@ static int nvme_sc_to_pr_err(int nvme_sc)
 	}
 }
 
+static int nvme_send_pr_command(struct block_device *bdev,
+		struct nvme_command *c, void *data, unsigned int data_len)
+{
+	if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
+	    bdev->bd_disk->fops == &nvme_ns_head_ops)
+		return nvme_send_ns_head_pr_command(bdev, c, data, data_len);
+
+	return nvme_send_ns_pr_command(bdev->bd_disk->private_data, c, data,
+				       data_len);
+}
+
 static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
 				u64 key, u64 sa_key, u8 op)
 {
@@ -87,13 +98,7 @@ static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
 	c.common.opcode = op;
 	c.common.cdw10 = cpu_to_le32(cdw10);
 
-	if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
-	    bdev->bd_disk->fops == &nvme_ns_head_ops)
-		ret = nvme_send_ns_head_pr_command(bdev, &c, data,
-						   sizeof(data));
-	else
-		ret = nvme_send_ns_pr_command(bdev->bd_disk->private_data, &c,
-					      data, sizeof(data));
+	ret = nvme_send_pr_command(bdev, &c, data, sizeof(data));
 	if (ret < 0)
 		return ret;
 
-- 
2.25.1

[PATCH v5 11/18] nvme: Add pr_ops read_keys support

[Mike Christie]

This patch adds support for the pr_ops read_keys callout by calling the
NVMe Reservation Report helper, then parsing that info to get the
controller's registered keys. Because the callout is only used in the
kernel where the callers, like LIO, do not know about controller/host IDs,
the callout just returns the registered keys which is required by the SCSI
PR in READ KEYS command.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/nvme/host/pr.c | 69 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/nvme.h   |  4 +++
 2 files changed, 73 insertions(+)

diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
index cd93d2e5b340..6aadcc25f3e2 100644
--- a/drivers/nvme/host/pr.c
+++ b/drivers/nvme/host/pr.c
@@ -154,10 +154,79 @@ static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type
 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
 }
 
+static int nvme_pr_resv_report(struct block_device *bdev, void *data,
+		u32 data_len, bool *eds)
+{
+	struct nvme_command c = { };
+	int ret;
+
+	c.common.opcode = nvme_cmd_resv_report;
+	c.common.cdw10 = cpu_to_le32(nvme_bytes_to_numd(data_len));
+	c.common.cdw11 = NVME_EXTENDED_DATA_STRUCT;
+	*eds = true;
+
+retry:
+	ret = nvme_send_pr_command(bdev, &c, data, data_len);
+	if (ret == NVME_SC_HOST_ID_INCONSIST &&
+	    c.common.cdw11 == NVME_EXTENDED_DATA_STRUCT) {
+		c.common.cdw11 = 0;
+		*eds = false;
+		goto retry;
+	}
+
+	if (ret < 0)
+		return ret;
+
+	return nvme_sc_to_pr_err(ret);
+}
+
+static int nvme_pr_read_keys(struct block_device *bdev,
+		struct pr_keys *keys_info)
+{
+	u32 rse_len, num_keys = keys_info->num_keys;
+	struct nvme_reservation_status_ext *rse;
+	int ret, i;
+	bool eds;
+
+	/*
+	 * Assume we are using 128-bit host IDs and allocate a buffer large
+	 * enough to get enough keys to fill the return keys buffer.
+	 */
+	rse_len = struct_size(rse, regctl_eds, num_keys);
+	rse = kzalloc(rse_len, GFP_KERNEL);
+	if (!rse)
+		return -ENOMEM;
+
+	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
+	if (ret)
+		goto free_rse;
+
+	keys_info->generation = le32_to_cpu(rse->gen);
+	keys_info->num_keys = get_unaligned_le16(&rse->regctl);
+
+	num_keys = min(num_keys, keys_info->num_keys);
+	for (i = 0; i < num_keys; i++) {
+		if (eds) {
+			keys_info->keys[i] =
+					le64_to_cpu(rse->regctl_eds[i].rkey);
+		} else {
+			struct nvme_reservation_status *rs;
+
+			rs = (struct nvme_reservation_status *)rse;
+			keys_info->keys[i] = le64_to_cpu(rs->regctl_ds[i].rkey);
+		}
+	}
+
+free_rse:
+	kfree(rse);
+	return ret;
+}
+
 const struct pr_ops nvme_pr_ops = {
 	.pr_register	= nvme_pr_register,
 	.pr_reserve	= nvme_pr_reserve,
 	.pr_release	= nvme_pr_release,
 	.pr_preempt	= nvme_pr_preempt,
 	.pr_clear	= nvme_pr_clear,
+	.pr_read_keys	= nvme_pr_read_keys,
 };
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 83704fc04a94..c18bd55a4ead 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -759,6 +759,10 @@ enum {
 	NVME_LBART_ATTRIB_HIDE	= 1 << 1,
 };
 
+enum nvme_eds {
+	NVME_EXTENDED_DATA_STRUCT	= 0x1,
+};
+
 struct nvme_registered_ctrl {
 	__le16	cntlid;
 	__u8	rcsts;
-- 
2.25.1

[PATCH v5 12/18] nvme: Add a nvme_pr_type enum

[Mike Christie]

The next patch adds support to report the reservation type, so we need to
be able to convert from the NVMe PR value we get from the device to the
linux block layer PR value that will be returned to callers. To prepare
for that, this patch adds a nvme_pr_type enum and renames the nvme_pr_type
function.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/pr.c | 24 ++++++++++++------------
 include/linux/nvme.h   |  9 +++++++++
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
index 6aadcc25f3e2..c550c172ff0d 100644
--- a/drivers/nvme/host/pr.c
+++ b/drivers/nvme/host/pr.c
@@ -9,24 +9,24 @@
 
 #include "nvme.h"
 
-static char nvme_pr_type(enum pr_type type)
+static enum nvme_pr_type nvme_pr_type_from_blk(enum pr_type type)
 {
 	switch (type) {
 	case PR_WRITE_EXCLUSIVE:
-		return 1;
+		return NVME_PR_WRITE_EXCLUSIVE;
 	case PR_EXCLUSIVE_ACCESS:
-		return 2;
+		return NVME_PR_EXCLUSIVE_ACCESS;
 	case PR_WRITE_EXCLUSIVE_REG_ONLY:
-		return 3;
+		return NVME_PR_WRITE_EXCLUSIVE_REG_ONLY;
 	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
-		return 4;
+		return NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY;
 	case PR_WRITE_EXCLUSIVE_ALL_REGS:
-		return 5;
+		return NVME_PR_WRITE_EXCLUSIVE_ALL_REGS;
 	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
-		return 6;
-	default:
-		return 0;
+		return NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS;
 	}
+
+	return 0;
 }
 
 static int nvme_send_ns_head_pr_command(struct block_device *bdev,
@@ -127,7 +127,7 @@ static int nvme_pr_reserve(struct block_device *bdev, u64 key,
 	if (flags & ~PR_FL_IGNORE_KEY)
 		return -EOPNOTSUPP;
 
-	cdw10 = nvme_pr_type(type) << 8;
+	cdw10 = nvme_pr_type_from_blk(type) << 8;
 	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
 }
@@ -135,7 +135,7 @@ static int nvme_pr_reserve(struct block_device *bdev, u64 key,
 static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
 		enum pr_type type, bool abort)
 {
-	u32 cdw10 = nvme_pr_type(type) << 8 | (abort ? 2 : 1);
+	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (abort ? 2 : 1);
 
 	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
 }
@@ -149,7 +149,7 @@ static int nvme_pr_clear(struct block_device *bdev, u64 key)
 
 static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
 {
-	u32 cdw10 = nvme_pr_type(type) << 8 | (key ? 0 : 1 << 3);
+	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (key ? 0 : 1 << 3);
 
 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
 }
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index c18bd55a4ead..182b6d614eb1 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -759,6 +759,15 @@ enum {
 	NVME_LBART_ATTRIB_HIDE	= 1 << 1,
 };
 
+enum nvme_pr_type {
+	NVME_PR_WRITE_EXCLUSIVE			= 1,
+	NVME_PR_EXCLUSIVE_ACCESS		= 2,
+	NVME_PR_WRITE_EXCLUSIVE_REG_ONLY	= 3,
+	NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY	= 4,
+	NVME_PR_WRITE_EXCLUSIVE_ALL_REGS	= 5,
+	NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS	= 6,
+};
+
 enum nvme_eds {
 	NVME_EXTENDED_DATA_STRUCT	= 0x1,
 };
-- 
2.25.1

[PATCH v5 13/18] nvme: Add pr_ops read_reservation support

[Mike Christie]

This patch adds support for the pr_ops read_reservation callout by
calling the NVMe Reservation Report helper. It then parses that info to
detect if there is a reservation and if there is then convert the
returned info to a pr_ops pr_held_reservation struct.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
---
 drivers/nvme/host/pr.c | 83 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
index c550c172ff0d..56d24bc3371a 100644
--- a/drivers/nvme/host/pr.c
+++ b/drivers/nvme/host/pr.c
@@ -29,6 +29,26 @@ static enum nvme_pr_type nvme_pr_type_from_blk(enum pr_type type)
 	return 0;
 }
 
+static enum pr_type block_pr_type_from_nvme(enum nvme_pr_type type)
+{
+	switch (type) {
+	case NVME_PR_WRITE_EXCLUSIVE:
+		return PR_WRITE_EXCLUSIVE;
+	case NVME_PR_EXCLUSIVE_ACCESS:
+		return PR_EXCLUSIVE_ACCESS;
+	case NVME_PR_WRITE_EXCLUSIVE_REG_ONLY:
+		return PR_WRITE_EXCLUSIVE_REG_ONLY;
+	case NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY:
+		return PR_EXCLUSIVE_ACCESS_REG_ONLY;
+	case NVME_PR_WRITE_EXCLUSIVE_ALL_REGS:
+		return PR_WRITE_EXCLUSIVE_ALL_REGS;
+	case NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS:
+		return PR_EXCLUSIVE_ACCESS_ALL_REGS;
+	}
+
+	return 0;
+}
+
 static int nvme_send_ns_head_pr_command(struct block_device *bdev,
 		struct nvme_command *c, void *data, unsigned int data_len)
 {
@@ -222,6 +242,68 @@ static int nvme_pr_read_keys(struct block_device *bdev,
 	return ret;
 }
 
+static int nvme_pr_read_reservation(struct block_device *bdev,
+		struct pr_held_reservation *resv)
+{
+	struct nvme_reservation_status_ext tmp_rse, *rse;
+	int ret, i, num_regs;
+	u32 rse_len;
+	bool eds;
+
+get_num_regs:
+	/*
+	 * Get the number of registrations so we know how big to allocate
+	 * the response buffer.
+	 */
+	ret = nvme_pr_resv_report(bdev, &tmp_rse, sizeof(tmp_rse), &eds);
+	if (ret)
+		return ret;
+
+	num_regs = get_unaligned_le16(&tmp_rse.regctl);
+	if (!num_regs) {
+		resv->generation = le32_to_cpu(tmp_rse.gen);
+		return 0;
+	}
+
+	rse_len = struct_size(rse, regctl_eds, num_regs);
+	rse = kzalloc(rse_len, GFP_KERNEL);
+	if (!rse)
+		return -ENOMEM;
+
+	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
+	if (ret)
+		goto free_rse;
+
+	if (num_regs != get_unaligned_le16(&rse->regctl)) {
+		kfree(rse);
+		goto get_num_regs;
+	}
+
+	resv->generation = le32_to_cpu(rse->gen);
+	resv->type = block_pr_type_from_nvme(rse->rtype);
+
+	for (i = 0; i < num_regs; i++) {
+		if (eds) {
+			if (rse->regctl_eds[i].rcsts) {
+				resv->key = le64_to_cpu(rse->regctl_eds[i].rkey);
+				break;
+			}
+		} else {
+			struct nvme_reservation_status *rs;
+
+			rs = (struct nvme_reservation_status *)rse;
+			if (rs->regctl_ds[i].rcsts) {
+				resv->key = le64_to_cpu(rs->regctl_ds[i].rkey);
+				break;
+			}
+		}
+	}
+
+free_rse:
+	kfree(rse);
+	return ret;
+}
+
 const struct pr_ops nvme_pr_ops = {
 	.pr_register	= nvme_pr_register,
 	.pr_reserve	= nvme_pr_reserve,
@@ -229,4 +311,5 @@ const struct pr_ops nvme_pr_ops = {
 	.pr_preempt	= nvme_pr_preempt,
 	.pr_clear	= nvme_pr_clear,
 	.pr_read_keys	= nvme_pr_read_keys,
+	.pr_read_reservation = nvme_pr_read_reservation,
 };
-- 
2.25.1

[PATCH v5 14/18] scsi: target: Rename sbc_ops to exec_cmd_ops

[Mike Christie]

The next patches allow us to call the block layer's pr_ops from the
backends. This will require allowing the backends to hook into the cmd
processing for SPC commands, so this renames sbc_ops to a more generic
exec_cmd_ops.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/target/target_core_file.c    |  4 ++--
 drivers/target/target_core_iblock.c  |  4 ++--
 drivers/target/target_core_rd.c      |  4 ++--
 drivers/target/target_core_sbc.c     | 13 +++++++------
 drivers/target/target_core_spc.c     |  4 ++--
 include/target/target_core_backend.h |  4 ++--
 6 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index ce0e000b74fc..4d447520bab8 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -896,7 +896,7 @@ static void fd_free_prot(struct se_device *dev)
 	fd_dev->fd_prot_file = NULL;
 }
 
-static struct sbc_ops fd_sbc_ops = {
+static struct exec_cmd_ops fd_exec_cmd_ops = {
 	.execute_rw		= fd_execute_rw,
 	.execute_sync_cache	= fd_execute_sync_cache,
 	.execute_write_same	= fd_execute_write_same,
@@ -906,7 +906,7 @@ static struct sbc_ops fd_sbc_ops = {
 static sense_reason_t
 fd_parse_cdb(struct se_cmd *cmd)
 {
-	return sbc_parse_cdb(cmd, &fd_sbc_ops);
+	return sbc_parse_cdb(cmd, &fd_exec_cmd_ops);
 }
 
 static const struct target_backend_ops fileio_ops = {
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index cc838ffd1294..d93f24f9687d 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -869,7 +869,7 @@ static unsigned int iblock_get_io_opt(struct se_device *dev)
 	return bdev_io_opt(bd);
 }
 
-static struct sbc_ops iblock_sbc_ops = {
+static struct exec_cmd_ops iblock_exec_cmd_ops = {
 	.execute_rw		= iblock_execute_rw,
 	.execute_sync_cache	= iblock_execute_sync_cache,
 	.execute_write_same	= iblock_execute_write_same,
@@ -879,7 +879,7 @@ static struct sbc_ops iblock_sbc_ops = {
 static sense_reason_t
 iblock_parse_cdb(struct se_cmd *cmd)
 {
-	return sbc_parse_cdb(cmd, &iblock_sbc_ops);
+	return sbc_parse_cdb(cmd, &iblock_exec_cmd_ops);
 }
 
 static bool iblock_get_write_cache(struct se_device *dev)
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index 6648c1c90e19..6f67cc09c2b5 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -643,14 +643,14 @@ static void rd_free_prot(struct se_device *dev)
 	rd_release_prot_space(rd_dev);
 }
 
-static struct sbc_ops rd_sbc_ops = {
+static struct exec_cmd_ops rd_exec_cmd_ops = {
 	.execute_rw		= rd_execute_rw,
 };
 
 static sense_reason_t
 rd_parse_cdb(struct se_cmd *cmd)
 {
-	return sbc_parse_cdb(cmd, &rd_sbc_ops);
+	return sbc_parse_cdb(cmd, &rd_exec_cmd_ops);
 }
 
 static const struct target_backend_ops rd_mcp_ops = {
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 7536ca797606..6a02561cc20c 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -192,7 +192,7 @@ EXPORT_SYMBOL(sbc_get_write_same_sectors);
 static sense_reason_t
 sbc_execute_write_same_unmap(struct se_cmd *cmd)
 {
-	struct sbc_ops *ops = cmd->protocol_data;
+	struct exec_cmd_ops *ops = cmd->protocol_data;
 	sector_t nolb = sbc_get_write_same_sectors(cmd);
 	sense_reason_t ret;
 
@@ -271,7 +271,8 @@ static inline unsigned long long transport_lba_64(unsigned char *cdb)
 }
 
 static sense_reason_t
-sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *ops)
+sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags,
+		     struct exec_cmd_ops *ops)
 {
 	struct se_device *dev = cmd->se_dev;
 	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
@@ -340,7 +341,7 @@ sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *op
 static sense_reason_t
 sbc_execute_rw(struct se_cmd *cmd)
 {
-	struct sbc_ops *ops = cmd->protocol_data;
+	struct exec_cmd_ops *ops = cmd->protocol_data;
 
 	return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 			       cmd->data_direction);
@@ -566,7 +567,7 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes
 static sense_reason_t
 sbc_compare_and_write(struct se_cmd *cmd)
 {
-	struct sbc_ops *ops = cmd->protocol_data;
+	struct exec_cmd_ops *ops = cmd->protocol_data;
 	struct se_device *dev = cmd->se_dev;
 	sense_reason_t ret;
 	int rc;
@@ -764,7 +765,7 @@ sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 }
 
 sense_reason_t
-sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
+sbc_parse_cdb(struct se_cmd *cmd, struct exec_cmd_ops *ops)
 {
 	struct se_device *dev = cmd->se_dev;
 	unsigned char *cdb = cmd->t_task_cdb;
@@ -1076,7 +1077,7 @@ EXPORT_SYMBOL(sbc_get_device_type);
 static sense_reason_t
 sbc_execute_unmap(struct se_cmd *cmd)
 {
-	struct sbc_ops *ops = cmd->protocol_data;
+	struct exec_cmd_ops *ops = cmd->protocol_data;
 	struct se_device *dev = cmd->se_dev;
 	unsigned char *buf, *ptr = NULL;
 	sector_t lba;
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index fcc7b10a7ae3..00d34616df5d 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -1431,7 +1431,7 @@ static struct target_opcode_descriptor tcm_opcode_write_verify16 = {
 
 static bool tcm_is_ws_enabled(struct se_cmd *cmd)
 {
-	struct sbc_ops *ops = cmd->protocol_data;
+	struct exec_cmd_ops *ops = cmd->protocol_data;
 	struct se_device *dev = cmd->se_dev;
 
 	return (dev->dev_attrib.emulate_tpws && !!ops->execute_unmap) ||
@@ -1544,7 +1544,7 @@ static struct target_opcode_descriptor tcm_opcode_sync_cache16 = {
 
 static bool tcm_is_unmap_enabled(struct se_cmd *cmd)
 {
-	struct sbc_ops *ops = cmd->protocol_data;
+	struct exec_cmd_ops *ops = cmd->protocol_data;
 	struct se_device *dev = cmd->se_dev;
 
 	return ops->execute_unmap && dev->dev_attrib.emulate_tpu;
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index a3c193df25b3..c5df78959532 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -62,7 +62,7 @@ struct target_backend_ops {
 	struct configfs_attribute **tb_dev_action_attrs;
 };
 
-struct sbc_ops {
+struct exec_cmd_ops {
 	sense_reason_t (*execute_rw)(struct se_cmd *cmd, struct scatterlist *,
 				     u32, enum dma_data_direction);
 	sense_reason_t (*execute_sync_cache)(struct se_cmd *cmd);
@@ -86,7 +86,7 @@ sense_reason_t	spc_emulate_report_luns(struct se_cmd *cmd);
 sense_reason_t	spc_emulate_inquiry_std(struct se_cmd *, unsigned char *);
 sense_reason_t	spc_emulate_evpd_83(struct se_cmd *, unsigned char *);
 
-sense_reason_t	sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops);
+sense_reason_t	sbc_parse_cdb(struct se_cmd *cmd, struct exec_cmd_ops *ops);
 u32	sbc_get_device_rev(struct se_device *dev);
 u32	sbc_get_device_type(struct se_device *dev);
 sector_t	sbc_get_write_same_sectors(struct se_cmd *cmd);
-- 
2.25.1

[PATCH v5 15/18] scsi: target: Allow backends to hook into PR handling

[Mike Christie]

For the cases where you want to export a device to a VM via a single
I_T nexus and want to passthrough the PR handling to the physical/real
device you have to use pscsi or tcmu. Both are good for specific uses
however for the case where you want good performance, and are not using
SCSI devices directly (using DM/MD RAID or multipath devices) then we are
out of luck.

The following patches allow iblock to mimimally hook into the LIO PR code
and then pass the PR handling to the physical device. Note that like with
the tcmu an pscsi cases it's only supported when you export the device via
one I_T nexus.

This patch adds the initial LIO callouts. The next patch will modify
iblock.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/target/target_core_pr.c      | 62 +++++++++++++++++++++++++++-
 include/target/target_core_backend.h |  4 ++
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 1493b1d01194..e16ef7d676af 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -3538,6 +3538,25 @@ core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
 	return ret;
 }
 
+static sense_reason_t
+target_try_pr_out_pt(struct se_cmd *cmd, u8 sa, u64 res_key, u64 sa_res_key,
+		     u8 type, bool aptpl, bool all_tg_pt, bool spec_i_pt)
+{
+	struct exec_cmd_ops *ops = cmd->protocol_data;
+
+	if (!cmd->se_sess || !cmd->se_lun) {
+		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+
+	if (!ops->execute_pr_out) {
+		pr_err("SPC-3 PR: Device has been configured for PR passthrough but it's not supported by the backend.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	return ops->execute_pr_out(cmd, sa, res_key, sa_res_key, type, aptpl);
+}
+
 /*
  * See spc4r17 section 6.14 Table 170
  */
@@ -3641,6 +3660,12 @@ target_scsi3_emulate_pr_out(struct se_cmd *cmd)
 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
 	}
 
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) {
+		ret = target_try_pr_out_pt(cmd, sa, res_key, sa_res_key, type,
+					   aptpl, all_tg_pt, spec_i_pt);
+		goto done;
+	}
+
 	/*
 	 * (core_scsi3_emulate_pro_* function parameters
 	 * are defined by spc4r17 Table 174:
@@ -3682,6 +3707,7 @@ target_scsi3_emulate_pr_out(struct se_cmd *cmd)
 		return TCM_INVALID_CDB_FIELD;
 	}
 
+done:
 	if (!ret)
 		target_complete_cmd(cmd, SAM_STAT_GOOD);
 	return ret;
@@ -4039,9 +4065,37 @@ core_scsi3_pri_read_full_status(struct se_cmd *cmd)
 	return 0;
 }
 
+static sense_reason_t target_try_pr_in_pt(struct se_cmd *cmd, u8 sa)
+{
+	struct exec_cmd_ops *ops = cmd->protocol_data;
+	unsigned char *buf;
+	sense_reason_t ret;
+
+	if (cmd->data_length < 8) {
+		pr_err("PRIN SA SCSI Data Length: %u too small\n",
+		       cmd->data_length);
+		return TCM_INVALID_CDB_FIELD;
+	}
+
+	if (!ops->execute_pr_in) {
+		pr_err("SPC-3 PR: Device has been configured for PR passthrough but it's not supported by the backend.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	buf = transport_kmap_data_sg(cmd);
+	if (!buf)
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	ret = ops->execute_pr_in(cmd, sa, buf);
+
+	transport_kunmap_data_sg(cmd);
+	return ret;
+}
+
 sense_reason_t
 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
 {
+	u8 sa = cmd->t_task_cdb[1] & 0x1f;
 	sense_reason_t ret;
 
 	/*
@@ -4060,7 +4114,12 @@ target_scsi3_emulate_pr_in(struct se_cmd *cmd)
 		return TCM_RESERVATION_CONFLICT;
 	}
 
-	switch (cmd->t_task_cdb[1] & 0x1f) {
+	if (cmd->se_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) {
+		ret = target_try_pr_in_pt(cmd, sa);
+		goto done;
+	}
+
+	switch (sa) {
 	case PRI_READ_KEYS:
 		ret = core_scsi3_pri_read_keys(cmd);
 		break;
@@ -4079,6 +4138,7 @@ target_scsi3_emulate_pr_in(struct se_cmd *cmd)
 		return TCM_INVALID_CDB_FIELD;
 	}
 
+done:
 	if (!ret)
 		target_complete_cmd(cmd, SAM_STAT_GOOD);
 	return ret;
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index c5df78959532..739df993aa5e 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -69,6 +69,10 @@ struct exec_cmd_ops {
 	sense_reason_t (*execute_write_same)(struct se_cmd *cmd);
 	sense_reason_t (*execute_unmap)(struct se_cmd *cmd,
 				sector_t lba, sector_t nolb);
+	sense_reason_t (*execute_pr_out)(struct se_cmd *cmd, u8 sa, u64 key,
+					 u64 sa_key, u8 type, bool aptpl);
+	sense_reason_t (*execute_pr_in)(struct se_cmd *cmd, u8 sa,
+					unsigned char *param_data);
 };
 
 int	transport_backend_register(const struct target_backend_ops *);
-- 
2.25.1

[PATCH v5 16/18] scsi: target: Pass struct target_opcode_descriptor to enabled

[Mike Christie]

The iblock pr_ops support does not support commands that require port or
I_T Nexus info. This adds a struct target_opcode_descriptor as an argument
to the enabled callout so we can still have the common tcm_is_pr_enabled
and tcm_is_scsi2_reservations_enabled functions and also determine if the
command is supported based on the command and service action and device
settings.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/target/target_core_spc.c  | 40 +++++++++++++++++++------------
 include/target/target_core_base.h |  3 ++-
 2 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 00d34616df5d..caf8d1325007 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -1429,7 +1429,8 @@ static struct target_opcode_descriptor tcm_opcode_write_verify16 = {
 	.update_usage_bits = set_dpofua_usage_bits,
 };
 
-static bool tcm_is_ws_enabled(struct se_cmd *cmd)
+static bool tcm_is_ws_enabled(struct target_opcode_descriptor *descr,
+			      struct se_cmd *cmd)
 {
 	struct exec_cmd_ops *ops = cmd->protocol_data;
 	struct se_device *dev = cmd->se_dev;
@@ -1456,7 +1457,8 @@ static struct target_opcode_descriptor tcm_opcode_write_same32 = {
 	.update_usage_bits = set_dpofua_usage_bits32,
 };
 
-static bool tcm_is_caw_enabled(struct se_cmd *cmd)
+static bool tcm_is_caw_enabled(struct target_opcode_descriptor *descr,
+			       struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1496,7 +1498,8 @@ static struct target_opcode_descriptor tcm_opcode_read_capacity16 = {
 		       0xff, 0xff, 0x00, SCSI_CONTROL_MASK},
 };
 
-static bool tcm_is_rep_ref_enabled(struct se_cmd *cmd)
+static bool tcm_is_rep_ref_enabled(struct target_opcode_descriptor *descr,
+				   struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1507,7 +1510,6 @@ static bool tcm_is_rep_ref_enabled(struct se_cmd *cmd)
 	}
 	spin_unlock(&dev->t10_alua.lba_map_lock);
 	return true;
-
 }
 
 static struct target_opcode_descriptor tcm_opcode_read_report_refferals = {
@@ -1542,7 +1544,8 @@ static struct target_opcode_descriptor tcm_opcode_sync_cache16 = {
 		       0xff, 0xff, SCSI_GROUP_NUMBER_MASK, SCSI_CONTROL_MASK},
 };
 
-static bool tcm_is_unmap_enabled(struct se_cmd *cmd)
+static bool tcm_is_unmap_enabled(struct target_opcode_descriptor *descr,
+				 struct se_cmd *cmd)
 {
 	struct exec_cmd_ops *ops = cmd->protocol_data;
 	struct se_device *dev = cmd->se_dev;
@@ -1664,7 +1667,8 @@ static struct target_opcode_descriptor tcm_opcode_pri_read_resrv = {
 		       0xff, SCSI_CONTROL_MASK},
 };
 
-static bool tcm_is_pr_enabled(struct se_cmd *cmd)
+static bool tcm_is_pr_enabled(struct target_opcode_descriptor *descr,
+			      struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1793,7 +1797,9 @@ static struct target_opcode_descriptor tcm_opcode_pro_register_move = {
 	.enabled = tcm_is_pr_enabled,
 };
 
-static bool tcm_is_scsi2_reservations_enabled(struct se_cmd *cmd)
+static bool
+tcm_is_scsi2_reservations_enabled(struct target_opcode_descriptor *descr,
+				  struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1854,7 +1860,8 @@ static struct target_opcode_descriptor tcm_opcode_inquiry = {
 		       0xff, SCSI_CONTROL_MASK},
 };
 
-static bool tcm_is_3pc_enabled(struct se_cmd *cmd)
+static bool tcm_is_3pc_enabled(struct target_opcode_descriptor *descr,
+			       struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1915,8 +1922,8 @@ static struct target_opcode_descriptor tcm_opcode_report_target_pgs = {
 		       0xff, 0xff, 0x00, SCSI_CONTROL_MASK},
 };
 
-
-static bool spc_rsoc_enabled(struct se_cmd *cmd)
+static bool spc_rsoc_enabled(struct target_opcode_descriptor *descr,
+			     struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1936,7 +1943,8 @@ static struct target_opcode_descriptor tcm_opcode_report_supp_opcodes = {
 	.enabled = spc_rsoc_enabled,
 };
 
-static bool tcm_is_set_tpg_enabled(struct se_cmd *cmd)
+static bool tcm_is_set_tpg_enabled(struct target_opcode_descriptor *descr,
+				   struct se_cmd *cmd)
 {
 	struct t10_alua_tg_pt_gp *l_tg_pt_gp;
 	struct se_lun *l_lun = cmd->se_lun;
@@ -2123,7 +2131,7 @@ spc_rsoc_get_descr(struct se_cmd *cmd, struct target_opcode_descriptor **opcode)
 			if (descr->serv_action_valid)
 				return TCM_INVALID_CDB_FIELD;
 
-			if (!descr->enabled || descr->enabled(cmd))
+			if (!descr->enabled || descr->enabled(descr, cmd))
 				*opcode = descr;
 			break;
 		case 0x2:
@@ -2137,7 +2145,8 @@ spc_rsoc_get_descr(struct se_cmd *cmd, struct target_opcode_descriptor **opcode)
 			 */
 			if (descr->serv_action_valid &&
 			    descr->service_action == requested_sa) {
-				if (!descr->enabled || descr->enabled(cmd))
+				if (!descr->enabled || descr->enabled(descr,
+								      cmd))
 					*opcode = descr;
 			} else if (!descr->serv_action_valid)
 				return TCM_INVALID_CDB_FIELD;
@@ -2150,7 +2159,8 @@ spc_rsoc_get_descr(struct se_cmd *cmd, struct target_opcode_descriptor **opcode)
 			 * be returned in the one_command parameter data format.
 			 */
 			if (descr->service_action == requested_sa)
-				if (!descr->enabled || descr->enabled(cmd))
+				if (!descr->enabled || descr->enabled(descr,
+								      cmd))
 					*opcode = descr;
 			break;
 		}
@@ -2207,7 +2217,7 @@ spc_emulate_report_supp_op_codes(struct se_cmd *cmd)
 
 		for (i = 0; i < ARRAY_SIZE(tcm_supported_opcodes); i++) {
 			descr = tcm_supported_opcodes[i];
-			if (descr->enabled && !descr->enabled(cmd))
+			if (descr->enabled && !descr->enabled(descr, cmd))
 				continue;
 
 			response_length += spc_rsoc_encode_command_descriptor(
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 12c9ba16217e..04646b3dbf75 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -878,7 +878,8 @@ struct target_opcode_descriptor {
 	u8			specific_timeout;
 	u16			nominal_timeout;
 	u16			recommended_timeout;
-	bool			(*enabled)(struct se_cmd *cmd);
+	bool			(*enabled)(struct target_opcode_descriptor *descr,
+					   struct se_cmd *cmd);
 	void			(*update_usage_bits)(u8 *usage_bits,
 						     struct se_device *dev);
 	u8			usage_bits[];
-- 
2.25.1

[PATCH v5 17/18] scsi: target: Report and detect unsupported PR commands

[Mike Christie]

The backend modules don't know about ports and I_T nexuses and the pr_ops
callouts the modules will use don't support the old RESERVE/RELEASE
commands. This patch has us report we don't support those types of
commands and fail them.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/target/target_core_pr.c  | 17 ++++++++
 drivers/target/target_core_spc.c | 75 +++++++++++++++++++++++---------
 2 files changed, 72 insertions(+), 20 deletions(-)

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index e16ef7d676af..7a3f07979a02 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -3554,6 +3554,18 @@ target_try_pr_out_pt(struct se_cmd *cmd, u8 sa, u64 res_key, u64 sa_res_key,
 		return TCM_UNSUPPORTED_SCSI_OPCODE;
 	}
 
+	switch (sa) {
+	case PRO_REGISTER_AND_MOVE:
+	case PRO_REPLACE_LOST_RESERVATION:
+		pr_err("SPC-3 PR: PRO_REGISTER_AND_MOVE and PRO_REPLACE_LOST_RESERVATION are not supported by PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	if (spec_i_pt || all_tg_pt) {
+		pr_err("SPC-3 PR: SPEC_I_PT and ALL_TG_PT are not supported by PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
 	return ops->execute_pr_out(cmd, sa, res_key, sa_res_key, type, aptpl);
 }
 
@@ -4082,6 +4094,11 @@ static sense_reason_t target_try_pr_in_pt(struct se_cmd *cmd, u8 sa)
 		return TCM_UNSUPPORTED_SCSI_OPCODE;
 	}
 
+	if (sa == PRI_READ_FULL_STATUS) {
+		pr_err("SPC-3 PR: PRI_READ_FULL_STATUS is not supported by PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
 	buf = transport_kmap_data_sg(cmd);
 	if (!buf)
 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index caf8d1325007..053bd2eea0e6 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -1672,7 +1672,41 @@ static bool tcm_is_pr_enabled(struct target_opcode_descriptor *descr,
 {
 	struct se_device *dev = cmd->se_dev;
 
-	return dev->dev_attrib.emulate_pr;
+	if (!dev->dev_attrib.emulate_pr)
+		return false;
+
+	if (!(dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
+		return true;
+
+	switch (descr->opcode) {
+	case RESERVE:
+	case RESERVE_10:
+	case RELEASE:
+	case RELEASE_10:
+		/*
+		 * The pr_ops which are used by the backend modules don't
+		 * support these commands.
+		 */
+		return false;
+	case PERSISTENT_RESERVE_OUT:
+		switch (descr->service_action) {
+		case PRO_REGISTER_AND_MOVE:
+		case PRO_REPLACE_LOST_RESERVATION:
+			/*
+			 * The backend modules don't have access to ports and
+			 * I_T nexuses so they can't handle these type of
+			 * requests.
+			 */
+			return false;
+		}
+		break;
+	case PERSISTENT_RESERVE_IN:
+		if (descr->service_action == PRI_READ_FULL_STATUS)
+			return false;
+		break;
+	}
+
+	return true;
 }
 
 static struct target_opcode_descriptor tcm_opcode_pri_read_caps = {
@@ -1797,22 +1831,13 @@ static struct target_opcode_descriptor tcm_opcode_pro_register_move = {
 	.enabled = tcm_is_pr_enabled,
 };
 
-static bool
-tcm_is_scsi2_reservations_enabled(struct target_opcode_descriptor *descr,
-				  struct se_cmd *cmd)
-{
-	struct se_device *dev = cmd->se_dev;
-
-	return dev->dev_attrib.emulate_pr;
-}
-
 static struct target_opcode_descriptor tcm_opcode_release = {
 	.support = SCSI_SUPPORT_FULL,
 	.opcode = RELEASE,
 	.cdb_size = 6,
 	.usage_bits = {RELEASE, 0x00, 0x00, 0x00,
 		       0x00, SCSI_CONTROL_MASK},
-	.enabled = tcm_is_scsi2_reservations_enabled,
+	.enabled = tcm_is_pr_enabled,
 };
 
 static struct target_opcode_descriptor tcm_opcode_release10 = {
@@ -1822,7 +1847,7 @@ static struct target_opcode_descriptor tcm_opcode_release10 = {
 	.usage_bits = {RELEASE_10, 0x00, 0x00, 0x00,
 		       0x00, 0x00, 0x00, 0xff,
 		       0xff, SCSI_CONTROL_MASK},
-	.enabled = tcm_is_scsi2_reservations_enabled,
+	.enabled = tcm_is_pr_enabled,
 };
 
 static struct target_opcode_descriptor tcm_opcode_reserve = {
@@ -1831,7 +1856,7 @@ static struct target_opcode_descriptor tcm_opcode_reserve = {
 	.cdb_size = 6,
 	.usage_bits = {RESERVE, 0x00, 0x00, 0x00,
 		       0x00, SCSI_CONTROL_MASK},
-	.enabled = tcm_is_scsi2_reservations_enabled,
+	.enabled = tcm_is_pr_enabled,
 };
 
 static struct target_opcode_descriptor tcm_opcode_reserve10 = {
@@ -1841,7 +1866,7 @@ static struct target_opcode_descriptor tcm_opcode_reserve10 = {
 	.usage_bits = {RESERVE_10, 0x00, 0x00, 0x00,
 		       0x00, 0x00, 0x00, 0xff,
 		       0xff, SCSI_CONTROL_MASK},
-	.enabled = tcm_is_scsi2_reservations_enabled,
+	.enabled = tcm_is_pr_enabled,
 };
 
 static struct target_opcode_descriptor tcm_opcode_request_sense = {
@@ -2246,12 +2271,22 @@ spc_parse_cdb(struct se_cmd *cmd, unsigned int *size)
 	struct se_device *dev = cmd->se_dev;
 	unsigned char *cdb = cmd->t_task_cdb;
 
-	if (!dev->dev_attrib.emulate_pr &&
-	    ((cdb[0] == PERSISTENT_RESERVE_IN) ||
-	     (cdb[0] == PERSISTENT_RESERVE_OUT) ||
-	     (cdb[0] == RELEASE || cdb[0] == RELEASE_10) ||
-	     (cdb[0] == RESERVE || cdb[0] == RESERVE_10))) {
-		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	switch (cdb[0]) {
+	case RESERVE:
+	case RESERVE_10:
+	case RELEASE:
+	case RELEASE_10:
+		if (!dev->dev_attrib.emulate_pr)
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+
+		if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		break;
+	case PERSISTENT_RESERVE_IN:
+	case PERSISTENT_RESERVE_OUT:
+		if (!dev->dev_attrib.emulate_pr)
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		break;
 	}
 
 	switch (cdb[0]) {
-- 
2.25.1

[PATCH v5 18/18] scsi: target: Add block PR support to iblock

[Mike Christie]

This adds support for the block PR callouts to target_core_iblock. This
patch doesn't attempt to implement the entire spec because there's no way
support it all like SPEC_I_PT and ALL_TG_PT. This only supports
exporting the iblock device from one path on the local target.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/target/target_core_iblock.c | 269 +++++++++++++++++++++++++++-
 1 file changed, 264 insertions(+), 5 deletions(-)

diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index d93f24f9687d..9d60259b03fd 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -23,13 +23,16 @@
 #include <linux/file.h>
 #include <linux/module.h>
 #include <linux/scatterlist.h>
+#include <linux/pr.h>
 #include <scsi/scsi_proto.h>
+#include <scsi/scsi_block_pr.h>
 #include <asm/unaligned.h>
 
 #include <target/target_core_base.h>
 #include <target/target_core_backend.h>
 
 #include "target_core_iblock.h"
+#include "target_core_pr.h"
 
 #define IBLOCK_MAX_BIO_PER_TASK	 32	/* max # of bios to submit at a time */
 #define IBLOCK_BIO_POOL_SIZE	128
@@ -310,7 +313,7 @@ static sector_t iblock_get_blocks(struct se_device *dev)
 	return blocks_long;
 }
 
-static void iblock_complete_cmd(struct se_cmd *cmd)
+static void iblock_complete_cmd(struct se_cmd *cmd, blk_status_t blk_status)
 {
 	struct iblock_req *ibr = cmd->priv;
 	u8 status;
@@ -318,7 +321,9 @@ static void iblock_complete_cmd(struct se_cmd *cmd)
 	if (!refcount_dec_and_test(&ibr->pending))
 		return;
 
-	if (atomic_read(&ibr->ib_bio_err_cnt))
+	if (blk_status == BLK_STS_RESV_CONFLICT)
+		status = SAM_STAT_RESERVATION_CONFLICT;
+	else if (atomic_read(&ibr->ib_bio_err_cnt))
 		status = SAM_STAT_CHECK_CONDITION;
 	else
 		status = SAM_STAT_GOOD;
@@ -331,6 +336,7 @@ static void iblock_bio_done(struct bio *bio)
 {
 	struct se_cmd *cmd = bio->bi_private;
 	struct iblock_req *ibr = cmd->priv;
+	blk_status_t blk_status = bio->bi_status;
 
 	if (bio->bi_status) {
 		pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
@@ -343,7 +349,7 @@ static void iblock_bio_done(struct bio *bio)
 
 	bio_put(bio);
 
-	iblock_complete_cmd(cmd);
+	iblock_complete_cmd(cmd, blk_status);
 }
 
 static struct bio *iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num,
@@ -759,7 +765,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 
 	if (!sgl_nents) {
 		refcount_set(&ibr->pending, 1);
-		iblock_complete_cmd(cmd);
+		iblock_complete_cmd(cmd, BLK_STS_OK);
 		return 0;
 	}
 
@@ -817,7 +823,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 	}
 
 	iblock_submit_bios(&list);
-	iblock_complete_cmd(cmd);
+	iblock_complete_cmd(cmd, BLK_STS_OK);
 	return 0;
 
 fail_put_bios:
@@ -829,6 +835,256 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 }
 
+static sense_reason_t iblock_execute_pr_out(struct se_cmd *cmd, u8 sa, u64 key,
+					    u64 sa_key, u8 type, bool aptpl)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
+	struct block_device *bdev = ib_dev->ibd_bd;
+	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
+	int ret;
+
+	if (!ops) {
+		pr_err("Block device does not support pr_ops but iblock device has been configured for PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	switch (sa) {
+	case PRO_REGISTER:
+	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
+		if (!ops->pr_register) {
+			pr_err("block device does not support pr_register.\n");
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		}
+
+		/* The block layer pr ops always enables aptpl */
+		if (!aptpl)
+			pr_info("APTPL not set by initiator, but will be used.\n");
+
+		ret = ops->pr_register(bdev, key, sa_key,
+				sa == PRO_REGISTER ? 0 : PR_FL_IGNORE_KEY);
+		break;
+	case PRO_RESERVE:
+		if (!ops->pr_reserve) {
+			pr_err("block_device does not support pr_reserve.\n");
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		}
+
+		ret = ops->pr_reserve(bdev, key, scsi_pr_type_to_block(type), 0);
+		break;
+	case PRO_CLEAR:
+		if (!ops->pr_clear) {
+			pr_err("block_device does not support pr_clear.\n");
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		}
+
+		ret = ops->pr_clear(bdev, key);
+		break;
+	case PRO_PREEMPT:
+	case PRO_PREEMPT_AND_ABORT:
+		if (!ops->pr_clear) {
+			pr_err("block_device does not support pr_preempt.\n");
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		}
+
+		ret = ops->pr_preempt(bdev, key, sa_key,
+				      scsi_pr_type_to_block(type),
+				      sa == PRO_PREEMPT ? false : true);
+		break;
+	case PRO_RELEASE:
+		if (!ops->pr_clear) {
+			pr_err("block_device does not support pr_pclear.\n");
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		}
+
+		ret = ops->pr_release(bdev, key, scsi_pr_type_to_block(type));
+		break;
+	default:
+		pr_err("Unknown PERSISTENT_RESERVE_OUT SA: 0x%02x\n", sa);
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	if (!ret)
+		return TCM_NO_SENSE;
+	else if (ret == PR_STS_RESERVATION_CONFLICT)
+		return TCM_RESERVATION_CONFLICT;
+	else
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+}
+
+static void iblock_pr_report_caps(unsigned char *param_data)
+{
+	u16 len = 8;
+
+	put_unaligned_be16(len, &param_data[0]);
+	/*
+	 * When using the pr_ops passthrough method we only support exporting
+	 * the device through one target port because from the backend module
+	 * level we can't see the target port config. As a result we only
+	 * support registration directly from the I_T nexus the cmd is sent
+	 * through and do not set ATP_C here.
+	 *
+	 * The block layer pr_ops do not support passing in initiators so
+	 * we don't set SIP_C here.
+	 */
+	/* PTPL_C: Persistence across Target Power Loss bit */
+	param_data[2] |= 0x01;
+	/*
+	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
+	 * set the TMV: Task Mask Valid bit.
+	 */
+	param_data[3] |= 0x80;
+	/*
+	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
+	 */
+	param_data[3] |= 0x10; /* ALLOW COMMANDs field 001b */
+	/*
+	 * PTPL_A: Persistence across Target Power Loss Active bit. The block
+	 * layer pr ops always enables this so report it active.
+	 */
+	param_data[3] |= 0x01;
+	/*
+	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 212 spc4r37.
+	 */
+	param_data[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
+	param_data[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
+	param_data[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
+	param_data[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
+	param_data[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
+	param_data[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
+}
+
+static int iblock_pr_read_keys(struct se_cmd *cmd, unsigned char *param_data)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
+	struct block_device *bdev = ib_dev->ibd_bd;
+	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
+	int i, ret, len, paths, data_offset;
+	struct pr_keys *keys;
+
+	if (!ops) {
+		pr_err("Block device does not support pr_ops but iblock device has been configured for PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	if (!ops->pr_read_keys) {
+		pr_err("Block device does not support read_keys.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	/*
+	 * We don't know what's under us, but dm-multipath will register every
+	 * path with the same key, so start off with enough space for 16 paths.
+	 */
+	paths = 16;
+retry:
+	len = 8 * paths;
+	keys = kzalloc(sizeof(*keys) + len, GFP_KERNEL);
+	if (!keys)
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	keys->num_keys = paths;
+	ret = ops->pr_read_keys(bdev, keys);
+	if (!ret) {
+		if (keys->num_keys > paths) {
+			kfree(keys);
+			paths *= 2;
+			goto retry;
+		}
+	} else if (ret) {
+		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		goto free_keys;
+	}
+
+	ret = TCM_NO_SENSE;
+
+	put_unaligned_be32(keys->generation, &param_data[0]);
+	if (!keys->num_keys) {
+		put_unaligned_be32(0, &param_data[4]);
+		goto free_keys;
+	}
+
+	put_unaligned_be32(8 * keys->num_keys, &param_data[4]);
+
+	data_offset = 8;
+	for (i = 0; i < keys->num_keys; i++) {
+		if (data_offset + 8 > cmd->data_length)
+			break;
+
+		put_unaligned_be64(keys->keys[i], &param_data[data_offset]);
+		data_offset += 8;
+	}
+
+free_keys:
+	kfree(keys);
+	return ret;
+}
+
+static int iblock_pr_read_reservation(struct se_cmd *cmd,
+				      unsigned char *param_data)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
+	struct block_device *bdev = ib_dev->ibd_bd;
+	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
+	struct pr_held_reservation rsv = { };
+
+	if (!ops) {
+		pr_err("Block device does not support pr_ops but iblock device has been configured for PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	if (!ops->pr_read_reservation) {
+		pr_err("Block device does not support read_keys.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	if (ops->pr_read_reservation(bdev, &rsv))
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	put_unaligned_be32(rsv.generation, &param_data[0]);
+	if (!block_pr_type_to_scsi(rsv.type)) {
+		put_unaligned_be32(0, &param_data[4]);
+		return TCM_NO_SENSE;
+	}
+
+	put_unaligned_be32(16, &param_data[4]);
+
+	if (cmd->data_length < 16)
+		return TCM_NO_SENSE;
+	put_unaligned_be64(rsv.key, &param_data[8]);
+
+	if (cmd->data_length < 22)
+		return TCM_NO_SENSE;
+	param_data[21] = block_pr_type_to_scsi(rsv.type);
+
+	return TCM_NO_SENSE;
+}
+
+static sense_reason_t iblock_execute_pr_in(struct se_cmd *cmd, u8 sa,
+					   unsigned char *param_data)
+{
+	sense_reason_t ret = TCM_NO_SENSE;
+
+	switch (sa) {
+	case PRI_REPORT_CAPABILITIES:
+		iblock_pr_report_caps(param_data);
+		break;
+	case PRI_READ_KEYS:
+		ret = iblock_pr_read_keys(cmd, param_data);
+		break;
+	case PRI_READ_RESERVATION:
+		ret = iblock_pr_read_reservation(cmd, param_data);
+		break;
+	default:
+		pr_err("Unknown PERSISTENT_RESERVE_IN SA: 0x%02x\n", sa);
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	return ret;
+}
+
 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 {
 	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
@@ -874,6 +1130,8 @@ static struct exec_cmd_ops iblock_exec_cmd_ops = {
 	.execute_sync_cache	= iblock_execute_sync_cache,
 	.execute_write_same	= iblock_execute_write_same,
 	.execute_unmap		= iblock_execute_unmap,
+	.execute_pr_out		= iblock_execute_pr_out,
+	.execute_pr_in		= iblock_execute_pr_in,
 };
 
 static sense_reason_t
@@ -890,6 +1148,7 @@ static bool iblock_get_write_cache(struct se_device *dev)
 static const struct target_backend_ops iblock_ops = {
 	.name			= "iblock",
 	.inquiry_prod		= "IBLOCK",
+	.transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR,
 	.inquiry_rev		= IBLOCK_VERSION,
 	.owner			= THIS_MODULE,
 	.attach_hba		= iblock_attach_hba,
-- 
2.25.1

Re: [PATCH v5 04/18] scsi: Move sd_pr_type to header to share

[Bart Van Assche]

On 3/24/23 11:17, Mike Christie wrote:
> diff --git a/include/scsi/scsi_block_pr.h b/include/scsi/scsi_block_pr.h
> new file mode 100644
> index 000000000000..44766d7a81d8
> --- /dev/null
> +++ b/include/scsi/scsi_block_pr.h
> @@ -0,0 +1,36 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _SCSI_BLOCK_PR_H
> +#define _SCSI_BLOCK_PR_H
> +
> +#include <uapi/linux/pr.h>
> +
> +enum scsi_pr_type {
> +	SCSI_PR_WRITE_EXCLUSIVE			= 0x01,
> +	SCSI_PR_EXCLUSIVE_ACCESS		= 0x03,
> +	SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY	= 0x05,
> +	SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY	= 0x06,
> +	SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS	= 0x07,
> +	SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS	= 0x08,
> +};
> +
> +static inline enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
> +{
> +	switch (type) {
> +	case PR_WRITE_EXCLUSIVE:
> +		return SCSI_PR_WRITE_EXCLUSIVE;
> +	case PR_EXCLUSIVE_ACCESS:
> +		return SCSI_PR_EXCLUSIVE_ACCESS;
> +	case PR_WRITE_EXCLUSIVE_REG_ONLY:
> +		return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
> +	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
> +		return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
> +	case PR_WRITE_EXCLUSIVE_ALL_REGS:
> +		return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
> +	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
> +		return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
> +	}
> +
> +	return 0;
> +}
> +
> +#endif

Hi Mike,

Has it been considered to move enum scsi_pr_type into 
include/scsi/scsi_common.h and block_pr_type_to_scsi() into 
drivers/scsi/scsi_common.c? Other definitions that are shared between 
SCSI initiator and SCSI target code exist in these files.

Thanks,

Bart.

Re: [PATCH v5 04/18] scsi: Move sd_pr_type to header to share

[michael.christie]

On 3/24/23 1:25 PM, Bart Van Assche wrote:
> On 3/24/23 11:17, Mike Christie wrote:
>> diff --git a/include/scsi/scsi_block_pr.h b/include/scsi/scsi_block_pr.h
>> new file mode 100644
>> index 000000000000..44766d7a81d8
>> --- /dev/null
>> +++ b/include/scsi/scsi_block_pr.h
>> @@ -0,0 +1,36 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _SCSI_BLOCK_PR_H
>> +#define _SCSI_BLOCK_PR_H
>> +
>> +#include <uapi/linux/pr.h>
>> +
>> +enum scsi_pr_type {
>> +    SCSI_PR_WRITE_EXCLUSIVE            = 0x01,
>> +    SCSI_PR_EXCLUSIVE_ACCESS        = 0x03,
>> +    SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY    = 0x05,
>> +    SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY    = 0x06,
>> +    SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS    = 0x07,
>> +    SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS    = 0x08,
>> +};
>> +
>> +static inline enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
>> +{
>> +    switch (type) {
>> +    case PR_WRITE_EXCLUSIVE:
>> +        return SCSI_PR_WRITE_EXCLUSIVE;
>> +    case PR_EXCLUSIVE_ACCESS:
>> +        return SCSI_PR_EXCLUSIVE_ACCESS;
>> +    case PR_WRITE_EXCLUSIVE_REG_ONLY:
>> +        return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
>> +    case PR_EXCLUSIVE_ACCESS_REG_ONLY:
>> +        return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
>> +    case PR_WRITE_EXCLUSIVE_ALL_REGS:
>> +        return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
>> +    case PR_EXCLUSIVE_ACCESS_ALL_REGS:
>> +        return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +#endif
> 
> Hi Mike,
> 
> Has it been considered to move enum scsi_pr_type into include/scsi/scsi_common.h and block_pr_type_to_scsi() into drivers/scsi/scsi_common.c? Other definitions that are shared between SCSI initiator and SCSI target code exist in these files.

Nice. I didn't know that existed. Will move them.

Re: [PATCH v5 01/18] block: Add PR callouts for read keys and reservation

[Bart Van Assche]

On 3/24/23 11:17, Mike Christie wrote:
> Add callouts for reading keys and reservations. This allows LIO to support
> the READ_KEYS and READ_RESERVATION commands and will allow dm-multipath
> to optimize it's error handling so it can check if it's getting an error
> because there's an existing reservation or if we need to retry different
> paths.
> 
> Note: This only initially adds the struct definitions in the kernel as I'm
> not sure if we wanted to export the interface to userspace yet. read_keys
> and read_reservation are exactly what dm-multipath and LIO need, but for a
> userspace interface we may want something like SCSI's READ_FULL_STATUS and
> NVMe's report reservation commands. Those are overkill for dm/LIO and
> READ_FULL_STATUS is sometimes broken for SCSI devices.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH v5 02/18] block: Rename BLK_STS_NEXUS to BLK_STS_RESV_CONFLICT

[Bart Van Assche]

On 3/24/23 11:17, Mike Christie wrote:
> BLK_STS_NEXUS is used for NVMe/SCSI reservation conflicts and DASD's
> locking feature which works similar to NVMe/SCSI reservations where a
> host can get a lock on a device and when the lock is taken it will get
> failures.
> 
> This patch renames BLK_STS_NEXUS so it better reflects this type of
> use.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH v5 03/18] scsi: Rename sd_pr_command

[Bart Van Assche]

On 3/24/23 11:17, Mike Christie wrote:
> Rename sd_pr_command to sd_pr_out_command to match a
> sd_pr_in_command helper added in the next patches.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH v5 11/18] nvme: Add pr_ops read_keys support

[kernel test robot]

Hi Mike,

I love your patch! Perhaps something to improve:

[auto build test WARNING on mkp-scsi/for-next]
[also build test WARNING on jejb-scsi/for-next axboe-block/for-next linus/master v6.3-rc4 next-20230328]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Mike-Christie/block-Add-PR-callouts-for-read-keys-and-reservation/20230325-022314
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
patch link:    https://lore.kernel.org/r/20230324181741.13908-12-michael.christie%40oracle.com
patch subject: [PATCH v5 11/18] nvme: Add pr_ops read_keys support
config: i386-randconfig-s002 (https://download.01.org/0day-ci/archive/20230328/202303281502.U47uzous-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://github.com/intel-lab-lkp/linux/commit/fcd2233cf643c550ab3cea2b6102077b1d05b389
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Mike-Christie/block-Add-PR-callouts-for-read-keys-and-reservation/20230325-022314
        git checkout fcd2233cf643c550ab3cea2b6102077b1d05b389
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 olddefconfig
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/nvme/host/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303281502.U47uzous-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/nvme/host/pr.c:165:24: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __le32 [assigned] [usertype] cdw11 @@     got int @@
   drivers/nvme/host/pr.c:165:24: sparse:     expected restricted __le32 [assigned] [usertype] cdw11
   drivers/nvme/host/pr.c:165:24: sparse:     got int
>> drivers/nvme/host/pr.c:171:21: sparse: sparse: restricted __le32 degrades to integer

vim +165 drivers/nvme/host/pr.c

   156	
   157	static int nvme_pr_resv_report(struct block_device *bdev, void *data,
   158			u32 data_len, bool *eds)
   159	{
   160		struct nvme_command c = { };
   161		int ret;
   162	
   163		c.common.opcode = nvme_cmd_resv_report;
   164		c.common.cdw10 = cpu_to_le32(nvme_bytes_to_numd(data_len));
 > 165		c.common.cdw11 = NVME_EXTENDED_DATA_STRUCT;
   166		*eds = true;
   167	
   168	retry:
   169		ret = nvme_send_pr_command(bdev, &c, data, data_len);
   170		if (ret == NVME_SC_HOST_ID_INCONSIST &&
 > 171		    c.common.cdw11 == NVME_EXTENDED_DATA_STRUCT) {
   172			c.common.cdw11 = 0;
   173			*eds = false;
   174			goto retry;
   175		}
   176	
   177		if (ret < 0)
   178			return ret;
   179	
   180		return nvme_sc_to_pr_err(ret);
   181	}
   182	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH v5 11/18] nvme: Add pr_ops read_keys support

[Mike Christie]

On 3/28/23 2:11 AM, kernel test robot wrote:
> Hi Mike,
> 
> I love your patch! Perhaps something to improve:
> 
> [auto build test WARNING on mkp-scsi/for-next]
> [also build test WARNING on jejb-scsi/for-next axboe-block/for-next linus/master v6.3-rc4 next-20230328]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Mike-Christie/block-Add-PR-callouts-for-read-keys-and-reservation/20230325-022314
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
> patch link:    https://lore.kernel.org/r/20230324181741.13908-12-michael.christie%40oracle.com
> patch subject: [PATCH v5 11/18] nvme: Add pr_ops read_keys support
> config: i386-randconfig-s002 (https://download.01.org/0day-ci/archive/20230328/202303281502.U47uzous-lkp@intel.com/config)
> compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
> reproduce:
>         # apt-get install sparse
>         # sparse version: v0.6.4-39-gce1a6720-dirty
>         # https://github.com/intel-lab-lkp/linux/commit/fcd2233cf643c550ab3cea2b6102077b1d05b389
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review Mike-Christie/block-Add-PR-callouts-for-read-keys-and-reservation/20230325-022314
>         git checkout fcd2233cf643c550ab3cea2b6102077b1d05b389
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 olddefconfig
>         make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/nvme/host/
> 
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@intel.com>
> | Link: https://lore.kernel.org/oe-kbuild-all/202303281502.U47uzous-lkp@intel.com/
> 
> sparse warnings: (new ones prefixed by >>)
>>> drivers/nvme/host/pr.c:165:24: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __le32 [assigned] [usertype] cdw11 @@     got int @@
>    drivers/nvme/host/pr.c:165:24: sparse:     expected restricted __le32 [assigned] [usertype] cdw11
>    drivers/nvme/host/pr.c:165:24: sparse:     got int
>>> drivers/nvme/host/pr.c:171:21: sparse: sparse: restricted __le32 degrades to integer
> 
> vim +165 drivers/nvme/host/pr.c
> 
>    156	
>    157	static int nvme_pr_resv_report(struct block_device *bdev, void *data,
>    158			u32 data_len, bool *eds)
>    159	{
>    160		struct nvme_command c = { };
>    161		int ret;
>    162	
>    163		c.common.opcode = nvme_cmd_resv_report;
>    164		c.common.cdw10 = cpu_to_le32(nvme_bytes_to_numd(data_len));
>  > 165		c.common.cdw11 = NVME_EXTENDED_DATA_STRUCT;
>    166		*eds = true;
>    167	
>    168	retry:
>    169		ret = nvme_send_pr_command(bdev, &c, data, data_len);
>    170		if (ret == NVME_SC_HOST_ID_INCONSIST &&
>  > 171		    c.common.cdw11 == NVME_EXTENDED_DATA_STRUCT) {

Kernel test bot is correct. Will fix.

Re: [PATCH v5 01/18] block: Add PR callouts for read keys and reservation

[Mike Snitzer]

On Fri, Mar 24 2023 at  2:17P -0400,
Mike Christie <michael.christie@oracle.com> wrote:

> Add callouts for reading keys and reservations. This allows LIO to support
> the READ_KEYS and READ_RESERVATION commands and will allow dm-multipath
> to optimize it's error handling so it can check if it's getting an error
> because there's an existing reservation or if we need to retry different
> paths.

Not seeing anything in DM's path selectors that adds these
optimizations. Is there accompanying multipath-tools callouts to get
at this data to optimize path selection (via DM table reloads)?

Mike

Re: [PATCH v5 01/18] block: Add PR callouts for read keys and reservation

[Mike Christie]

On 3/28/23 11:36 AM, Mike Snitzer wrote:
> On Fri, Mar 24 2023 at  2:17P -0400,
> Mike Christie <michael.christie@oracle.com> wrote:
> 
>> Add callouts for reading keys and reservations. This allows LIO to support
>> the READ_KEYS and READ_RESERVATION commands and will allow dm-multipath
>> to optimize it's error handling so it can check if it's getting an error
>> because there's an existing reservation or if we need to retry different
>> paths.
> 
> Not seeing anything in DM's path selectors that adds these
> optimizations. Is there accompanying multipath-tools callouts to get
> at this data to optimize path selection (via DM table reloads)?
> 

You can ignore that comment. The comment was meant for the dm pr callouts
and not for normal IO/path handling, and now I think I can fix in a different
way.

I originally added the comment about better dm error handling for something
like __dm_pr_register getting a failure when it did:

        ret = ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);

Right now, we fail the entire operation if just one call on one path fails. With the
pr_read_keys/reservation callouts we could check if we got a failure because there
was an existing reservation vs a retryable/ignorable error.

I forgot I wrote that comment about dm in the mail and we actually don't need the
pr_read_* callouts for that type of thing now, because I ended up changing
the existing callouts to return common error codes last kernel. So I have another
patchset that I'm working on, but am still debating about some issues like:

ret = ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
switch (ret) {
case PR_STS_RESERVATION_CONFLICT:
	pr->ret = ret;
	return -1;
case PR_STS_RETRY_PATH_FAILURE:
	/*
	 * We probably want to retry like how we do for the pg_init.
	 */
	....
case PR_STS_PATH_FAILED:
case PR_STS_PATH_FAST_FAILED:
	/*
	 * I'm still not sure what to do here, because if this is the last
	 * host then we might want to try and register the rest of the paths
	 * and limp on. It probably needs a user config option.
	 */
	....

Re: [PATCH v5 18/18] scsi: target: Add block PR support to iblock

[kernel test robot]

Hi Mike,

kernel test robot noticed the following build warnings:

[auto build test WARNING on mkp-scsi/for-next]
[also build test WARNING on jejb-scsi/for-next axboe-block/for-next linus/master v6.3-rc5 next-20230403]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Mike-Christie/block-Add-PR-callouts-for-read-keys-and-reservation/20230325-022314
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
patch link:    https://lore.kernel.org/r/20230324181741.13908-19-michael.christie%40oracle.com
patch subject: [PATCH v5 18/18] scsi: target: Add block PR support to iblock
config: ia64-randconfig-s043-20230403 (https://download.01.org/0day-ci/archive/20230404/202304041322.SEFV29Co-lkp@intel.com/config)
compiler: ia64-linux-gcc (GCC) 12.1.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://github.com/intel-lab-lkp/linux/commit/f3fe3a0cab8498044d99362b81e01f5c48da5f63
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Mike-Christie/block-Add-PR-callouts-for-read-keys-and-reservation/20230325-022314
        git checkout f3fe3a0cab8498044d99362b81e01f5c48da5f63
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=ia64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=ia64 SHELL=/bin/bash drivers/target/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304041322.SEFV29Co-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/target/target_core_iblock.c:968:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:968:24: sparse:     expected int
   drivers/target/target_core_iblock.c:968:24: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:973:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:973:24: sparse:     expected int
   drivers/target/target_core_iblock.c:973:24: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:985:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:985:24: sparse:     expected int
   drivers/target/target_core_iblock.c:985:24: sparse:     got restricted sense_reason_t
>> drivers/target/target_core_iblock.c:996:21: sparse: sparse: incorrect type in assignment (different base types) @@     expected int [assigned] ret @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:996:21: sparse:     expected int [assigned] ret
   drivers/target/target_core_iblock.c:996:21: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:1000:13: sparse: sparse: incorrect type in assignment (different base types) @@     expected int [assigned] ret @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:1000:13: sparse:     expected int [assigned] ret
   drivers/target/target_core_iblock.c:1000:13: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:1035:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:1035:24: sparse:     expected int
   drivers/target/target_core_iblock.c:1035:24: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:1040:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:1040:24: sparse:     expected int
   drivers/target/target_core_iblock.c:1040:24: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:1044:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:1044:24: sparse:     expected int
   drivers/target/target_core_iblock.c:1044:24: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:1049:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:1049:24: sparse:     expected int
   drivers/target/target_core_iblock.c:1049:24: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:1055:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:1055:24: sparse:     expected int
   drivers/target/target_core_iblock.c:1055:24: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:1059:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:1059:24: sparse:     expected int
   drivers/target/target_core_iblock.c:1059:24: sparse:     got restricted sense_reason_t
   drivers/target/target_core_iblock.c:1062:16: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted sense_reason_t @@
   drivers/target/target_core_iblock.c:1062:16: sparse:     expected int
   drivers/target/target_core_iblock.c:1062:16: sparse:     got restricted sense_reason_t
>> drivers/target/target_core_iblock.c:1075:21: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted sense_reason_t [usertype] ret @@     got int @@
   drivers/target/target_core_iblock.c:1075:21: sparse:     expected restricted sense_reason_t [usertype] ret
   drivers/target/target_core_iblock.c:1075:21: sparse:     got int
   drivers/target/target_core_iblock.c:1078:21: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted sense_reason_t [usertype] ret @@     got int @@
   drivers/target/target_core_iblock.c:1078:21: sparse:     expected restricted sense_reason_t [usertype] ret
   drivers/target/target_core_iblock.c:1078:21: sparse:     got int

vim +968 drivers/target/target_core_iblock.c

   956	
   957	static int iblock_pr_read_keys(struct se_cmd *cmd, unsigned char *param_data)
   958	{
   959		struct se_device *dev = cmd->se_dev;
   960		struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
   961		struct block_device *bdev = ib_dev->ibd_bd;
   962		const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
   963		int i, ret, len, paths, data_offset;
   964		struct pr_keys *keys;
   965	
   966		if (!ops) {
   967			pr_err("Block device does not support pr_ops but iblock device has been configured for PR passthrough.\n");
 > 968			return TCM_UNSUPPORTED_SCSI_OPCODE;
   969		}
   970	
   971		if (!ops->pr_read_keys) {
   972			pr_err("Block device does not support read_keys.\n");
   973			return TCM_UNSUPPORTED_SCSI_OPCODE;
   974		}
   975	
   976		/*
   977		 * We don't know what's under us, but dm-multipath will register every
   978		 * path with the same key, so start off with enough space for 16 paths.
   979		 */
   980		paths = 16;
   981	retry:
   982		len = 8 * paths;
   983		keys = kzalloc(sizeof(*keys) + len, GFP_KERNEL);
   984		if (!keys)
   985			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
   986	
   987		keys->num_keys = paths;
   988		ret = ops->pr_read_keys(bdev, keys);
   989		if (!ret) {
   990			if (keys->num_keys > paths) {
   991				kfree(keys);
   992				paths *= 2;
   993				goto retry;
   994			}
   995		} else if (ret) {
 > 996			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
   997			goto free_keys;
   998		}
   999	
  1000		ret = TCM_NO_SENSE;
  1001	
  1002		put_unaligned_be32(keys->generation, &param_data[0]);
  1003		if (!keys->num_keys) {
  1004			put_unaligned_be32(0, &param_data[4]);
  1005			goto free_keys;
  1006		}
  1007	
  1008		put_unaligned_be32(8 * keys->num_keys, &param_data[4]);
  1009	
  1010		data_offset = 8;
  1011		for (i = 0; i < keys->num_keys; i++) {
  1012			if (data_offset + 8 > cmd->data_length)
  1013				break;
  1014	
  1015			put_unaligned_be64(keys->keys[i], &param_data[data_offset]);
  1016			data_offset += 8;
  1017		}
  1018	
  1019	free_keys:
  1020		kfree(keys);
  1021		return ret;
  1022	}
  1023	
  1024	static int iblock_pr_read_reservation(struct se_cmd *cmd,
  1025					      unsigned char *param_data)
  1026	{
  1027		struct se_device *dev = cmd->se_dev;
  1028		struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  1029		struct block_device *bdev = ib_dev->ibd_bd;
  1030		const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
  1031		struct pr_held_reservation rsv = { };
  1032	
  1033		if (!ops) {
  1034			pr_err("Block device does not support pr_ops but iblock device has been configured for PR passthrough.\n");
  1035			return TCM_UNSUPPORTED_SCSI_OPCODE;
  1036		}
  1037	
  1038		if (!ops->pr_read_reservation) {
  1039			pr_err("Block device does not support read_keys.\n");
  1040			return TCM_UNSUPPORTED_SCSI_OPCODE;
  1041		}
  1042	
  1043		if (ops->pr_read_reservation(bdev, &rsv))
  1044			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
  1045	
  1046		put_unaligned_be32(rsv.generation, &param_data[0]);
  1047		if (!block_pr_type_to_scsi(rsv.type)) {
  1048			put_unaligned_be32(0, &param_data[4]);
  1049			return TCM_NO_SENSE;
  1050		}
  1051	
  1052		put_unaligned_be32(16, &param_data[4]);
  1053	
  1054		if (cmd->data_length < 16)
> 1055			return TCM_NO_SENSE;
  1056		put_unaligned_be64(rsv.key, &param_data[8]);
  1057	
  1058		if (cmd->data_length < 22)
  1059			return TCM_NO_SENSE;
  1060		param_data[21] = block_pr_type_to_scsi(rsv.type);
  1061	
  1062		return TCM_NO_SENSE;
  1063	}
  1064	
  1065	static sense_reason_t iblock_execute_pr_in(struct se_cmd *cmd, u8 sa,
  1066						   unsigned char *param_data)
  1067	{
  1068		sense_reason_t ret = TCM_NO_SENSE;
  1069	
  1070		switch (sa) {
  1071		case PRI_REPORT_CAPABILITIES:
  1072			iblock_pr_report_caps(param_data);
  1073			break;
  1074		case PRI_READ_KEYS:
> 1075			ret = iblock_pr_read_keys(cmd, param_data);
  1076			break;
  1077		case PRI_READ_RESERVATION:
  1078			ret = iblock_pr_read_reservation(cmd, param_data);
  1079			break;
  1080		default:
  1081			pr_err("Unknown PERSISTENT_RESERVE_IN SA: 0x%02x\n", sa);
  1082			return TCM_UNSUPPORTED_SCSI_OPCODE;
  1083		}
  1084	
  1085		return ret;
  1086	}
  1087	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests