[PATCH v8 00/19] Pass data lifetime information to SCSI disk devices

[PATCH v8 00/19] Pass data lifetime information to SCSI disk devices

[Bart Van Assche]

Hi Martin,

UFS vendors need the data lifetime information to achieve good performance.
Providing data lifetime information to UFS devices can result in up to 40%
lower write amplification. Hence this patch series that adds support in F2FS
and also in the block layer for data lifetime information. The SCSI disk (sd)
driver is modified such that it passes write hint information to SCSI devices
via the GROUP NUMBER field.

Please consider this patch series for the next merge window.

Thank you,

Bart.

Changes compared to v7:
 - As requested by Dave Chinner, changed one occurrence of
   file_inode(dio->iocb->ki_filp)->i_write_hint into inode->i_write_hint.
 - Modified the description of patch 03/19 since the patch that restores
   F_[GS]ET_FILE_RW_HINT has been removed.
 - Added Reviewed-by tags from v6 of this patch series and that were missing
   when v7 was posted.

Changes compared to v6:
 - Dropped patch "fs: Restore F_[GS]ET_FILE_RW_HINT support".

Changes compared to v5:
 - Added compile-time tests that compare the WRITE_LIFE_* and RWH_* constants.
 - Split the F_[GS]ET_RW_HINT handlers.
 - Removed the structure member kiocb.ki_hint again. Instead, copy the data
   lifetime information directly from struct file into a bio.
 - Together with Doug Gilbert, fixed multiple bugs in the scsi_debug patches.
   Added Doug's Tested-by.
 - Changed the type of "rscs:1" from bool into unsigned.
 - Added unit tests for the new SCSI protocol data structures.
 - Improved multiple patch descriptions.
 
Changes compared to v4:
 - Dropped the patch that renames the WRITE_LIFE_* constants.
 - Added a fix for an argument check in fcntl_rw_hint().
 - Reordered the patches that restore data lifetime support.
 - Included a fix for data lifetime support for buffered I/O to raw block
   devices.

Changes compared to v3:
 - Renamed the data lifetime constants (WRITE_LIFE_*).
 - Fixed a checkpatch complaint by changing "unsigned" into "unsigned int".
 - Rebased this patch series on top of kernel v6.7-rc1.
 
Changes compared to v2:
 - Instead of storing data lifetime information in bi_ioprio, introduce the
   new struct bio member bi_lifetime and also the struct request member
   'lifetime'.
 - Removed the bio_set_data_lifetime() and bio_get_data_lifetime() functions
   and replaced these with direct assignments.
 - Dropped all changes related to I/O priority.
 - Improved patch descriptions.

Changes compared to v1:
 - Use six bits from the ioprio field for data lifetime information. The
   bio->bi_write_hint / req->write_hint / iocb->ki_hint members that were
   introduced in v1 have been removed again.
 - The F_GET_FILE_RW_HINT and F_SET_FILE_RW_HINT fcntls have been removed.
 - In the SCSI disk (sd) driver, query the stream status and check the PERM bit.
 - The GET STREAM STATUS command has been implemented in the scsi_debug driver.

Bart Van Assche (19):
  fs: Fix rw_hint validation
  fs: Verify write lifetime constants at compile time
  fs: Split fcntl_rw_hint()
  fs: Move enum rw_hint into a new header file
  block, fs: Restore the per-bio/request data lifetime fields
  block, fs: Propagate write hints to the block device inode
  fs/f2fs: Restore the whint_mode mount option
  fs/f2fs: Restore support for tracing data lifetimes
  scsi: core: Query the Block Limits Extension VPD page
  scsi: scsi_proto: Add structures and constants related to I/O groups
    and streams
  scsi: sd: Translate data lifetime information
  scsi: scsi_debug: Reduce code duplication
  scsi: scsi_debug: Support the block limits extension VPD page
  scsi: scsi_debug: Rework page code error handling
  scsi: scsi_debug: Rework subpage code error handling
  scsi: scsi_debug: Allocate the MODE SENSE response from the heap
  scsi: scsi_debug: Implement the IO Advice Hints Grouping mode page
  scsi: scsi_debug: Implement GET STREAM STATUS
  scsi: scsi_debug: Maintain write statistics per group number

 Documentation/filesystems/f2fs.rst |  70 +++++++
 block/bio.c                        |   2 +
 block/blk-crypto-fallback.c        |   1 +
 block/blk-merge.c                  |   8 +
 block/blk-mq.c                     |   2 +
 block/bounce.c                     |   1 +
 block/fops.c                       |  14 ++
 drivers/scsi/Kconfig               |   5 +
 drivers/scsi/Makefile              |   2 +
 drivers/scsi/scsi.c                |   2 +
 drivers/scsi/scsi_debug.c          | 293 ++++++++++++++++++++++-------
 drivers/scsi/scsi_proto_test.c     |  56 ++++++
 drivers/scsi/scsi_sysfs.c          |  10 +
 drivers/scsi/sd.c                  | 111 ++++++++++-
 drivers/scsi/sd.h                  |   3 +
 fs/buffer.c                        |  12 +-
 fs/direct-io.c                     |   2 +
 fs/f2fs/data.c                     |   2 +
 fs/f2fs/f2fs.h                     |  10 +
 fs/f2fs/segment.c                  |  95 ++++++++++
 fs/f2fs/super.c                    |  32 +++-
 fs/fcntl.c                         |  63 ++++---
 fs/inode.c                         |   1 +
 fs/iomap/buffered-io.c             |   2 +
 fs/iomap/direct-io.c               |   1 +
 fs/mpage.c                         |   1 +
 include/linux/blk-mq.h             |   2 +
 include/linux/blk_types.h          |   2 +
 include/linux/fs.h                 |  17 +-
 include/linux/rw_hint.h            |  21 +++
 include/scsi/scsi_device.h         |   1 +
 include/scsi/scsi_proto.h          |  78 ++++++++
 include/trace/events/f2fs.h        |   6 +-
 33 files changed, 813 insertions(+), 115 deletions(-)
 create mode 100644 drivers/scsi/scsi_proto_test.c
 create mode 100644 include/linux/rw_hint.h

[PATCH v8 01/19] fs: Fix rw_hint validation

[Bart Van Assche]

Reject values that are valid rw_hints after truncation but not before
truncation by passing an untruncated value to rw_hint_valid().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 5657cb0797c4 ("fs/fcntl: use copy_to/from_user() for u64 types")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 fs/fcntl.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index c80a6acad742..3ff707bf2743 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -268,7 +268,7 @@ static int f_getowner_uids(struct file *filp, unsigned long arg)
 }
 #endif
 
-static bool rw_hint_valid(enum rw_hint hint)
+static bool rw_hint_valid(u64 hint)
 {
 	switch (hint) {
 	case RWH_WRITE_LIFE_NOT_SET:
@@ -288,19 +288,17 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd,
 {
 	struct inode *inode = file_inode(file);
 	u64 __user *argp = (u64 __user *)arg;
-	enum rw_hint hint;
-	u64 h;
+	u64 hint;
 
 	switch (cmd) {
 	case F_GET_RW_HINT:
-		h = inode->i_write_hint;
-		if (copy_to_user(argp, &h, sizeof(*argp)))
+		hint = inode->i_write_hint;
+		if (copy_to_user(argp, &hint, sizeof(*argp)))
 			return -EFAULT;
 		return 0;
 	case F_SET_RW_HINT:
-		if (copy_from_user(&h, argp, sizeof(h)))
+		if (copy_from_user(&hint, argp, sizeof(hint)))
 			return -EFAULT;
-		hint = (enum rw_hint) h;
 		if (!rw_hint_valid(hint))
 			return -EINVAL;
 

[PATCH v8 02/19] fs: Verify write lifetime constants at compile time

[Bart Van Assche]

The code in fs/fcntl.c converts RWH_* constants to and from WRITE_LIFE_*
constants using casts. Verify at compile time that these casts will yield
the intended effect.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 fs/fcntl.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 3ff707bf2743..f3bc4662455f 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -270,6 +270,13 @@ static int f_getowner_uids(struct file *filp, unsigned long arg)
 
 static bool rw_hint_valid(u64 hint)
 {
+	BUILD_BUG_ON(WRITE_LIFE_NOT_SET != RWH_WRITE_LIFE_NOT_SET);
+	BUILD_BUG_ON(WRITE_LIFE_NONE != RWH_WRITE_LIFE_NONE);
+	BUILD_BUG_ON(WRITE_LIFE_SHORT != RWH_WRITE_LIFE_SHORT);
+	BUILD_BUG_ON(WRITE_LIFE_MEDIUM != RWH_WRITE_LIFE_MEDIUM);
+	BUILD_BUG_ON(WRITE_LIFE_LONG != RWH_WRITE_LIFE_LONG);
+	BUILD_BUG_ON(WRITE_LIFE_EXTREME != RWH_WRITE_LIFE_EXTREME);
+
 	switch (hint) {
 	case RWH_WRITE_LIFE_NOT_SET:
 	case RWH_WRITE_LIFE_NONE:

[PATCH v8 03/19] fs: Split fcntl_rw_hint()

[Bart Van Assche]

Split fcntl_rw_hint() such that there is one helper function per fcntl. No
functionality is changed by this patch.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 fs/fcntl.c | 47 ++++++++++++++++++++++++++---------------------
 1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index f3bc4662455f..5fa2d95114bf 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -290,32 +290,35 @@ static bool rw_hint_valid(u64 hint)
 	}
 }
 
-static long fcntl_rw_hint(struct file *file, unsigned int cmd,
-			  unsigned long arg)
+static long fcntl_get_rw_hint(struct file *file, unsigned int cmd,
+			      unsigned long arg)
 {
 	struct inode *inode = file_inode(file);
 	u64 __user *argp = (u64 __user *)arg;
-	u64 hint;
+	u64 hint = inode->i_write_hint;
 
-	switch (cmd) {
-	case F_GET_RW_HINT:
-		hint = inode->i_write_hint;
-		if (copy_to_user(argp, &hint, sizeof(*argp)))
-			return -EFAULT;
-		return 0;
-	case F_SET_RW_HINT:
-		if (copy_from_user(&hint, argp, sizeof(hint)))
-			return -EFAULT;
-		if (!rw_hint_valid(hint))
-			return -EINVAL;
+	if (copy_to_user(argp, &hint, sizeof(*argp)))
+		return -EFAULT;
+	return 0;
+}
 
-		inode_lock(inode);
-		inode->i_write_hint = hint;
-		inode_unlock(inode);
-		return 0;
-	default:
+static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
+			      unsigned long arg)
+{
+	struct inode *inode = file_inode(file);
+	u64 __user *argp = (u64 __user *)arg;
+	u64 hint;
+
+	if (copy_from_user(&hint, argp, sizeof(hint)))
+		return -EFAULT;
+	if (!rw_hint_valid(hint))
 		return -EINVAL;
-	}
+
+	inode_lock(inode);
+	inode->i_write_hint = hint;
+	inode_unlock(inode);
+
+	return 0;
 }
 
 static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
@@ -421,8 +424,10 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
 		err = memfd_fcntl(filp, cmd, argi);
 		break;
 	case F_GET_RW_HINT:
+		err = fcntl_get_rw_hint(filp, cmd, arg);
+		break;
 	case F_SET_RW_HINT:
-		err = fcntl_rw_hint(filp, cmd, arg);
+		err = fcntl_set_rw_hint(filp, cmd, arg);
 		break;
 	default:
 		break;

[PATCH v8 04/19] fs: Move enum rw_hint into a new header file

[Bart Van Assche]

Move enum rw_hint into a new header file to prepare for using this data
type in the block layer. Add the attribute __packed to reduce the space
occupied by instances of this data type from four bytes to one byte.
Change the data type of i_write_hint from u8 into enum rw_hint.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 fs/f2fs/f2fs.h          |  1 +
 fs/fcntl.c              |  1 +
 fs/inode.c              |  1 +
 include/linux/fs.h      | 16 ++--------------
 include/linux/rw_hint.h | 21 +++++++++++++++++++++
 5 files changed, 26 insertions(+), 14 deletions(-)
 create mode 100644 include/linux/rw_hint.h

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 9043cedfa12b..8e0c66a6b097 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -24,6 +24,7 @@
 #include <linux/blkdev.h>
 #include <linux/quotaops.h>
 #include <linux/part_stat.h>
+#include <linux/rw_hint.h>
 #include <crypto/hash.h>
 
 #include <linux/fscrypt.h>
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 5fa2d95114bf..fc73c5fae43c 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -27,6 +27,7 @@
 #include <linux/memfd.h>
 #include <linux/compat.h>
 #include <linux/mount.h>
+#include <linux/rw_hint.h>
 
 #include <linux/poll.h>
 #include <asm/siginfo.h>
diff --git a/fs/inode.c b/fs/inode.c
index edcd8a61975f..a1384807ab58 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -20,6 +20,7 @@
 #include <linux/ratelimit.h>
 #include <linux/list_lru.h>
 #include <linux/iversion.h>
+#include <linux/rw_hint.h>
 #include <trace/events/writeback.h>
 #include "internal.h"
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 98b7a7a8c42e..a08014b68d6e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -43,6 +43,7 @@
 #include <linux/cred.h>
 #include <linux/mnt_idmapping.h>
 #include <linux/slab.h>
+#include <linux/rw_hint.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -309,19 +310,6 @@ struct address_space;
 struct writeback_control;
 struct readahead_control;
 
-/*
- * Write life time hint values.
- * Stored in struct inode as u8.
- */
-enum rw_hint {
-	WRITE_LIFE_NOT_SET	= 0,
-	WRITE_LIFE_NONE		= RWH_WRITE_LIFE_NONE,
-	WRITE_LIFE_SHORT	= RWH_WRITE_LIFE_SHORT,
-	WRITE_LIFE_MEDIUM	= RWH_WRITE_LIFE_MEDIUM,
-	WRITE_LIFE_LONG		= RWH_WRITE_LIFE_LONG,
-	WRITE_LIFE_EXTREME	= RWH_WRITE_LIFE_EXTREME,
-};
-
 /* Match RWF_* bits to IOCB bits */
 #define IOCB_HIPRI		(__force int) RWF_HIPRI
 #define IOCB_DSYNC		(__force int) RWF_DSYNC
@@ -677,7 +665,7 @@ struct inode {
 	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
 	unsigned short          i_bytes;
 	u8			i_blkbits;
-	u8			i_write_hint;
+	enum rw_hint		i_write_hint;
 	blkcnt_t		i_blocks;
 
 #ifdef __NEED_I_SIZE_ORDERED
diff --git a/include/linux/rw_hint.h b/include/linux/rw_hint.h
new file mode 100644
index 000000000000..6334ec6e6663
--- /dev/null
+++ b/include/linux/rw_hint.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_RW_HINT_H
+#define _LINUX_RW_HINT_H
+
+#include <linux/build_bug.h>
+#include <linux/compiler_attributes.h>
+#include <uapi/linux/fcntl.h>
+
+/* Block storage write lifetime hint values. */
+enum rw_hint {
+	WRITE_LIFE_NOT_SET	= RWH_WRITE_LIFE_NOT_SET,
+	WRITE_LIFE_NONE		= RWH_WRITE_LIFE_NONE,
+	WRITE_LIFE_SHORT	= RWH_WRITE_LIFE_SHORT,
+	WRITE_LIFE_MEDIUM	= RWH_WRITE_LIFE_MEDIUM,
+	WRITE_LIFE_LONG		= RWH_WRITE_LIFE_LONG,
+	WRITE_LIFE_EXTREME	= RWH_WRITE_LIFE_EXTREME,
+} __packed;
+
+static_assert(sizeof(enum rw_hint) == 1);
+
+#endif /* _LINUX_RW_HINT_H */

[PATCH v8 05/19] block, fs: Restore the per-bio/request data lifetime fields

[Bart Van Assche]

Restore support for passing data lifetime information from filesystems to
block drivers. This patch reverts commit b179c98f7697 ("block: Remove
request.write_hint") and commit c75e707fe1aa ("block: remove the
per-bio/request write hint").

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 block/bio.c                 |  2 ++
 block/blk-crypto-fallback.c |  1 +
 block/blk-merge.c           |  8 ++++++++
 block/blk-mq.c              |  2 ++
 block/bounce.c              |  1 +
 block/fops.c                |  3 +++
 fs/buffer.c                 | 12 ++++++++----
 fs/direct-io.c              |  2 ++
 fs/iomap/buffered-io.c      |  2 ++
 fs/iomap/direct-io.c        |  1 +
 fs/mpage.c                  |  1 +
 include/linux/blk-mq.h      |  2 ++
 include/linux/blk_types.h   |  2 ++
 13 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 816d412c06e9..755fcde5cb66 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -251,6 +251,7 @@ void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
 	bio->bi_opf = opf;
 	bio->bi_flags = 0;
 	bio->bi_ioprio = 0;
+	bio->bi_write_hint = 0;
 	bio->bi_status = 0;
 	bio->bi_iter.bi_sector = 0;
 	bio->bi_iter.bi_size = 0;
@@ -813,6 +814,7 @@ static int __bio_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp)
 {
 	bio_set_flag(bio, BIO_CLONED);
 	bio->bi_ioprio = bio_src->bi_ioprio;
+	bio->bi_write_hint = bio_src->bi_write_hint;
 	bio->bi_iter = bio_src->bi_iter;
 
 	if (bio->bi_bdev) {
diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
index e6468eab2681..b1e7415f8439 100644
--- a/block/blk-crypto-fallback.c
+++ b/block/blk-crypto-fallback.c
@@ -172,6 +172,7 @@ static struct bio *blk_crypto_fallback_clone_bio(struct bio *bio_src)
 	if (bio_flagged(bio_src, BIO_REMAPPED))
 		bio_set_flag(bio, BIO_REMAPPED);
 	bio->bi_ioprio		= bio_src->bi_ioprio;
+	bio->bi_write_hint	= bio_src->bi_write_hint;
 	bio->bi_iter.bi_sector	= bio_src->bi_iter.bi_sector;
 	bio->bi_iter.bi_size	= bio_src->bi_iter.bi_size;
 
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 65e75efa9bd3..65bbbf6cf1fe 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -814,6 +814,10 @@ static struct request *attempt_merge(struct request_queue *q,
 	if (rq_data_dir(req) != rq_data_dir(next))
 		return NULL;
 
+	/* Don't merge requests with different write hints. */
+	if (req->write_hint != next->write_hint)
+		return NULL;
+
 	if (req->ioprio != next->ioprio)
 		return NULL;
 
@@ -941,6 +945,10 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 	if (!bio_crypt_rq_ctx_compatible(rq, bio))
 		return false;
 
+	/* Don't merge requests with different write hints. */
+	if (rq->write_hint != bio->bi_write_hint)
+		return false;
+
 	if (rq->ioprio != bio_prio(bio))
 		return false;
 
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e2d11183f62e..081df9faf499 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2551,6 +2551,7 @@ static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
 		rq->cmd_flags |= REQ_FAILFAST_MASK;
 
 	rq->__sector = bio->bi_iter.bi_sector;
+	rq->write_hint = bio->bi_write_hint;
 	blk_rq_bio_prep(rq, bio, nr_segs);
 
 	/* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */
@@ -3143,6 +3144,7 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 	}
 	rq->nr_phys_segments = rq_src->nr_phys_segments;
 	rq->ioprio = rq_src->ioprio;
+	rq->write_hint = rq_src->write_hint;
 
 	if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0)
 		goto free_and_out;
diff --git a/block/bounce.c b/block/bounce.c
index 7cfcb242f9a1..d6a5219f29dd 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -169,6 +169,7 @@ static struct bio *bounce_clone_bio(struct bio *bio_src)
 	if (bio_flagged(bio_src, BIO_REMAPPED))
 		bio_set_flag(bio, BIO_REMAPPED);
 	bio->bi_ioprio		= bio_src->bi_ioprio;
+	bio->bi_write_hint	= bio_src->bi_write_hint;
 	bio->bi_iter.bi_sector	= bio_src->bi_iter.bi_sector;
 	bio->bi_iter.bi_size	= bio_src->bi_iter.bi_size;
 
diff --git a/block/fops.c b/block/fops.c
index 0abaac705daf..787ce52bc2c6 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -73,6 +73,7 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
 		bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb));
 	}
 	bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
+	bio.bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
 	bio.bi_ioprio = iocb->ki_ioprio;
 
 	ret = bio_iov_iter_get_pages(&bio, iter);
@@ -203,6 +204,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 
 	for (;;) {
 		bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
+		bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
 		bio->bi_private = dio;
 		bio->bi_end_io = blkdev_bio_end_io;
 		bio->bi_ioprio = iocb->ki_ioprio;
@@ -321,6 +323,7 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
 	dio->flags = 0;
 	dio->iocb = iocb;
 	bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
+	bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
 	bio->bi_end_io = blkdev_bio_end_io_async;
 	bio->bi_ioprio = iocb->ki_ioprio;
 
diff --git a/fs/buffer.c b/fs/buffer.c
index 967f34b70aa8..76834398e713 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -55,7 +55,7 @@
 
 static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
 static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
-			  struct writeback_control *wbc);
+			  enum rw_hint hint, struct writeback_control *wbc);
 
 #define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers)
 
@@ -1903,7 +1903,8 @@ int __block_write_full_folio(struct inode *inode, struct folio *folio,
 	do {
 		struct buffer_head *next = bh->b_this_page;
 		if (buffer_async_write(bh)) {
-			submit_bh_wbc(REQ_OP_WRITE | write_flags, bh, wbc);
+			submit_bh_wbc(REQ_OP_WRITE | write_flags, bh,
+				      inode->i_write_hint, wbc);
 			nr_underway++;
 		}
 		bh = next;
@@ -1957,7 +1958,8 @@ int __block_write_full_folio(struct inode *inode, struct folio *folio,
 		struct buffer_head *next = bh->b_this_page;
 		if (buffer_async_write(bh)) {
 			clear_buffer_dirty(bh);
-			submit_bh_wbc(REQ_OP_WRITE | write_flags, bh, wbc);
+			submit_bh_wbc(REQ_OP_WRITE | write_flags, bh,
+				      inode->i_write_hint, wbc);
 			nr_underway++;
 		}
 		bh = next;
@@ -2777,6 +2779,7 @@ static void end_bio_bh_io_sync(struct bio *bio)
 }
 
 static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
+			  enum rw_hint write_hint,
 			  struct writeback_control *wbc)
 {
 	const enum req_op op = opf & REQ_OP_MASK;
@@ -2804,6 +2807,7 @@ static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
 	fscrypt_set_bio_crypt_ctx_bh(bio, bh, GFP_NOIO);
 
 	bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
+	bio->bi_write_hint = write_hint;
 
 	__bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
 
@@ -2823,7 +2827,7 @@ static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
 
 void submit_bh(blk_opf_t opf, struct buffer_head *bh)
 {
-	submit_bh_wbc(opf, bh, NULL);
+	submit_bh_wbc(opf, bh, WRITE_LIFE_NOT_SET, NULL);
 }
 EXPORT_SYMBOL(submit_bh);
 
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 20533266ade6..5261ab8bcdaa 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -410,6 +410,8 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
 		bio->bi_end_io = dio_bio_end_io;
 	if (dio->is_pinned)
 		bio_set_flag(bio, BIO_PAGE_PINNED);
+	bio->bi_write_hint = file_inode(dio->iocb->ki_filp)->i_write_hint;
+
 	sdio->bio = bio;
 	sdio->logical_offset_in_bio = sdio->cur_page_fs_offset;
 }
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index f72df2babe56..191eb575485e 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1677,6 +1677,7 @@ iomap_alloc_ioend(struct inode *inode, struct iomap_writepage_ctx *wpc,
 			       REQ_OP_WRITE | wbc_to_write_flags(wbc),
 			       GFP_NOFS, &iomap_ioend_bioset);
 	bio->bi_iter.bi_sector = sector;
+	bio->bi_write_hint = inode->i_write_hint;
 	wbc_init_bio(wbc, bio);
 
 	ioend = container_of(bio, struct iomap_ioend, io_inline_bio);
@@ -1707,6 +1708,7 @@ iomap_chain_bio(struct bio *prev)
 	new = bio_alloc(prev->bi_bdev, BIO_MAX_VECS, prev->bi_opf, GFP_NOFS);
 	bio_clone_blkg_association(new, prev);
 	new->bi_iter.bi_sector = bio_end_sector(prev);
+	new->bi_write_hint = prev->bi_write_hint;
 
 	bio_chain(prev, new);
 	bio_get(prev);		/* for iomap_finish_ioend */
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index bcd3f8cf5ea4..f3b43d223a46 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -380,6 +380,7 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
 		fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits,
 					  GFP_KERNEL);
 		bio->bi_iter.bi_sector = iomap_sector(iomap, pos);
+		bio->bi_write_hint = inode->i_write_hint;
 		bio->bi_ioprio = dio->iocb->ki_ioprio;
 		bio->bi_private = dio;
 		bio->bi_end_io = iomap_dio_bio_end_io;
diff --git a/fs/mpage.c b/fs/mpage.c
index ffb064ed9d04..268785f2bb53 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -611,6 +611,7 @@ static int __mpage_writepage(struct folio *folio, struct writeback_control *wbc,
 				GFP_NOFS);
 		bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);
 		wbc_init_bio(wbc, bio);
+		bio->bi_write_hint = inode->i_write_hint;
 	}
 
 	/*
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 1ab3081c82ed..479f26af76bd 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -8,6 +8,7 @@
 #include <linux/scatterlist.h>
 #include <linux/prefetch.h>
 #include <linux/srcu.h>
+#include <linux/rw_hint.h>
 
 struct blk_mq_tags;
 struct blk_flush_queue;
@@ -135,6 +136,7 @@ struct request {
 	struct blk_crypto_keyslot *crypt_keyslot;
 #endif
 
+	enum rw_hint write_hint;
 	unsigned short ioprio;
 
 	enum mq_rq_state state;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index d5c5e59ddbd2..8410957f4313 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -10,6 +10,7 @@
 #include <linux/bvec.h>
 #include <linux/device.h>
 #include <linux/ktime.h>
+#include <linux/rw_hint.h>
 
 struct bio_set;
 struct bio;
@@ -269,6 +270,7 @@ struct bio {
 						 */
 	unsigned short		bi_flags;	/* BIO_* below */
 	unsigned short		bi_ioprio;
+	enum rw_hint		bi_write_hint;
 	blk_status_t		bi_status;
 	atomic_t		__bi_remaining;
 

[PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Bart Van Assche]

Write hints applied with F_SET_RW_HINT on a block device affect the
shmem inode only. Propagate these hints to the block device inode
because that is the inode used when writing back dirty pages.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 block/fops.c       | 11 +++++++++++
 fs/fcntl.c         |  4 ++++
 include/linux/fs.h |  1 +
 3 files changed, 16 insertions(+)

diff --git a/block/fops.c b/block/fops.c
index 787ce52bc2c6..138b388b5cb1 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -620,6 +620,16 @@ static int blkdev_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+static void blkdev_apply_whint(struct file *file, enum rw_hint hint)
+{
+	struct bdev_handle *handle = file->private_data;
+	struct inode *bd_inode = handle->bdev->bd_inode;
+
+	inode_lock(bd_inode);
+	bd_inode->i_write_hint = hint;
+	inode_unlock(bd_inode);
+}
+
 static ssize_t
 blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from)
 {
@@ -854,6 +864,7 @@ const struct file_operations def_blk_fops = {
 	.splice_read	= filemap_splice_read,
 	.splice_write	= iter_file_splice_write,
 	.fallocate	= blkdev_fallocate,
+	.apply_whint	= blkdev_apply_whint,
 };
 
 static __init int blkdev_init(void)
diff --git a/fs/fcntl.c b/fs/fcntl.c
index fc73c5fae43c..18407bf5bb9b 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -306,6 +306,7 @@ static long fcntl_get_rw_hint(struct file *file, unsigned int cmd,
 static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
 			      unsigned long arg)
 {
+	void (*apply_whint)(struct file *, enum rw_hint);
 	struct inode *inode = file_inode(file);
 	u64 __user *argp = (u64 __user *)arg;
 	u64 hint;
@@ -317,6 +318,9 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
 
 	inode_lock(inode);
 	inode->i_write_hint = hint;
+	apply_whint = inode->i_fop->apply_whint;
+	if (apply_whint)
+		apply_whint(file, hint);
 	inode_unlock(inode);
 
 	return 0;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a08014b68d6e..293017ea2466 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1944,6 +1944,7 @@ struct file_operations {
 	int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags);
 	int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *,
 				unsigned int poll_flags);
+	void (*apply_whint)(struct file *, enum rw_hint hint);
 } __randomize_layout;
 
 /* Wrap a directory iterator that needs exclusive inode access */

[PATCH v8 07/19] fs/f2fs: Restore the whint_mode mount option

[Bart Van Assche]

Allow users to control which write hints are passed to the block layer:
- whint_mode=off - no write hints are passed to the block layer.
- whint_mode=user-based - write hints are derived from inode->i_write_hint
  and also from the system.advise xattr information (hot and cold bits).
- whint_mode=fs-based - F2FS chooses write hints.

This patch reverts commit 930e2607638d ("f2fs: remove obsolete whint_mode").

Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 Documentation/filesystems/f2fs.rst | 70 ++++++++++++++++++++++
 fs/f2fs/data.c                     |  2 +
 fs/f2fs/f2fs.h                     |  9 +++
 fs/f2fs/segment.c                  | 95 ++++++++++++++++++++++++++++++
 fs/f2fs/super.c                    | 32 +++++++++-
 5 files changed, 207 insertions(+), 1 deletion(-)

diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index d32c6209685d..de412ddebcc8 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -242,6 +242,12 @@ offgrpjquota		 Turn off group journalled quota.
 offprjjquota		 Turn off project journalled quota.
 quota			 Enable plain user disk quota accounting.
 noquota			 Disable all plain disk quota option.
+whint_mode=%s		 Control which write hints are passed down to block
+			 layer. This supports "off", "user-based", and
+			 "fs-based".  In "off" mode (default), f2fs does not pass
+			 down hints. In "user-based" mode, f2fs tries to pass
+			 down hints given by users. And in "fs-based" mode, f2fs
+			 passes down hints with its policy.
 alloc_mode=%s		 Adjust block allocation policy, which supports "reuse"
 			 and "default".
 fsync_mode=%s		 Control the policy of fsync. Currently supports "posix",
@@ -776,6 +782,70 @@ In order to identify whether the data in the victim segment are valid or not,
 F2FS manages a bitmap. Each bit represents the validity of a block, and the
 bitmap is composed of a bit stream covering whole blocks in main area.
 
+Write-hint Policy
+-----------------
+
+1) whint_mode=off. F2FS only passes down WRITE_LIFE_NOT_SET.
+
+2) whint_mode=user-based. F2FS tries to pass down hints given by
+users.
+
+===================== ======================== ===================
+User                  F2FS                     Block
+===================== ======================== ===================
+N/A                   META                     WRITE_LIFE_NOT_SET
+N/A                   HOT_NODE                 "
+N/A                   WARM_NODE                "
+N/A                   COLD_NODE                "
+ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
+extension list        "                        "
+
+-- buffered io
+WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+WRITE_LIFE_NONE       "                        "
+WRITE_LIFE_MEDIUM     "                        "
+WRITE_LIFE_LONG       "                        "
+
+-- direct io
+WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
+WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
+WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
+===================== ======================== ===================
+
+3) whint_mode=fs-based. F2FS passes down hints with its policy.
+
+===================== ======================== ===================
+User                  F2FS                     Block
+===================== ======================== ===================
+N/A                   META                     WRITE_LIFE_MEDIUM;
+N/A                   HOT_NODE                 WRITE_LIFE_NOT_SET
+N/A                   WARM_NODE                "
+N/A                   COLD_NODE                WRITE_LIFE_NONE
+ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
+extension list        "                        "
+
+-- buffered io
+WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_LONG
+WRITE_LIFE_NONE       "                        "
+WRITE_LIFE_MEDIUM     "                        "
+WRITE_LIFE_LONG       "                        "
+
+-- direct io
+WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
+WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
+WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
+===================== ======================== ===================
+
 Fallocate(2) Policy
 -------------------
 
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 4e42b5f24deb..12ad311a22f6 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -478,6 +478,8 @@ static struct bio *__bio_alloc(struct f2fs_io_info *fio, int npages)
 	} else {
 		bio->bi_end_io = f2fs_write_end_io;
 		bio->bi_private = sbi;
+		bio->bi_write_hint = f2fs_io_type_to_rw_hint(sbi,
+						fio->type, fio->temp);
 	}
 	iostat_alloc_and_bind_ctx(sbi, bio, NULL);
 
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 8e0c66a6b097..1bf1bce887d5 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -141,6 +141,12 @@ struct f2fs_rwsem {
 #endif
 };
 
+enum whint_mode {
+	WHINT_MODE_OFF,		/* not pass down write hints */
+	WHINT_MODE_USER,	/* try to pass down hints given by users */
+	WHINT_MODE_FS,		/* pass down hints with F2FS policy */
+};
+
 struct f2fs_mount_info {
 	unsigned int opt;
 	int write_io_size_bits;		/* Write IO size bits */
@@ -158,6 +164,7 @@ struct f2fs_mount_info {
 	int s_jquota_fmt;			/* Format of quota to use */
 #endif
 	/* For which write hints are passed down to block layer */
+	enum whint_mode whint_mode;
 	int alloc_mode;			/* segment allocation policy */
 	int fsync_mode;			/* fsync policy */
 	int fs_mode;			/* fs mode: LFS or ADAPTIVE */
@@ -3731,6 +3738,8 @@ void f2fs_destroy_segment_manager(struct f2fs_sb_info *sbi);
 int __init f2fs_create_segment_manager_caches(void);
 void f2fs_destroy_segment_manager_caches(void);
 int f2fs_rw_hint_to_seg_type(enum rw_hint hint);
+enum rw_hint f2fs_io_type_to_rw_hint(struct f2fs_sb_info *sbi,
+			enum page_type type, enum temp_type temp);
 unsigned int f2fs_usable_segs_in_sec(struct f2fs_sb_info *sbi,
 			unsigned int segno);
 unsigned int f2fs_usable_blks_in_seg(struct f2fs_sb_info *sbi,
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 727d016318f9..e1a2eb1a1db9 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3290,6 +3290,101 @@ int f2fs_rw_hint_to_seg_type(enum rw_hint hint)
 	}
 }
 
+/* This returns write hints for each segment type. This hints will be
+ * passed down to block layer. There are mapping tables which depend on
+ * the mount option 'whint_mode'.
+ *
+ * 1) whint_mode=off. F2FS only passes down WRITE_LIFE_NOT_SET.
+ *
+ * 2) whint_mode=user-based. F2FS tries to pass down hints given by users.
+ *
+ * User                  F2FS                     Block
+ * ----                  ----                     -----
+ *                       META                     WRITE_LIFE_NOT_SET
+ *                       HOT_NODE                 "
+ *                       WARM_NODE                "
+ *                       COLD_NODE                "
+ * ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
+ * extension list        "                        "
+ *
+ * -- buffered io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+ * WRITE_LIFE_NONE       "                        "
+ * WRITE_LIFE_MEDIUM     "                        "
+ * WRITE_LIFE_LONG       "                        "
+ *
+ * -- direct io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+ * WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
+ * WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
+ * WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
+ *
+ * 3) whint_mode=fs-based. F2FS passes down hints with its policy.
+ *
+ * User                  F2FS                     Block
+ * ----                  ----                     -----
+ *                       META                     WRITE_LIFE_MEDIUM;
+ *                       HOT_NODE                 WRITE_LIFE_NOT_SET
+ *                       WARM_NODE                "
+ *                       COLD_NODE                WRITE_LIFE_NONE
+ * ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
+ * extension list        "                        "
+ *
+ * -- buffered io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_LONG
+ * WRITE_LIFE_NONE       "                        "
+ * WRITE_LIFE_MEDIUM     "                        "
+ * WRITE_LIFE_LONG       "                        "
+ *
+ * -- direct io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+ * WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
+ * WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
+ * WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
+ */
+
+enum rw_hint f2fs_io_type_to_rw_hint(struct f2fs_sb_info *sbi,
+				enum page_type type, enum temp_type temp)
+{
+	if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_USER) {
+		if (type == DATA) {
+			if (temp == WARM)
+				return WRITE_LIFE_NOT_SET;
+			else if (temp == HOT)
+				return WRITE_LIFE_SHORT;
+			else if (temp == COLD)
+				return WRITE_LIFE_EXTREME;
+		} else {
+			return WRITE_LIFE_NOT_SET;
+		}
+	} else if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_FS) {
+		if (type == DATA) {
+			if (temp == WARM)
+				return WRITE_LIFE_LONG;
+			else if (temp == HOT)
+				return WRITE_LIFE_SHORT;
+			else if (temp == COLD)
+				return WRITE_LIFE_EXTREME;
+		} else if (type == NODE) {
+			if (temp == WARM || temp == HOT)
+				return WRITE_LIFE_NOT_SET;
+			else if (temp == COLD)
+				return WRITE_LIFE_NONE;
+		} else if (type == META) {
+			return WRITE_LIFE_MEDIUM;
+		}
+	}
+	return WRITE_LIFE_NOT_SET;
+}
+
 static int __get_segment_type_2(struct f2fs_io_info *fio)
 {
 	if (fio->type == DATA)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 033af907c3b1..441f2a309d8a 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -156,6 +156,7 @@ enum {
 	Opt_jqfmt_vfsold,
 	Opt_jqfmt_vfsv0,
 	Opt_jqfmt_vfsv1,
+	Opt_whint,
 	Opt_alloc,
 	Opt_fsync,
 	Opt_test_dummy_encryption,
@@ -235,6 +236,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
+	{Opt_whint, "whint_mode=%s"},
 	{Opt_alloc, "alloc_mode=%s"},
 	{Opt_fsync, "fsync_mode=%s"},
 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
@@ -1026,6 +1028,22 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 			f2fs_info(sbi, "quota operations not supported");
 			break;
 #endif
+		case Opt_whint:
+			name = match_strdup(&args[0]);
+			if (!name)
+				return -ENOMEM;
+			if (!strcmp(name, "user-based")) {
+				F2FS_OPTION(sbi).whint_mode = WHINT_MODE_USER;
+			} else if (!strcmp(name, "off")) {
+				F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
+			} else if (!strcmp(name, "fs-based")) {
+				F2FS_OPTION(sbi).whint_mode = WHINT_MODE_FS;
+			} else {
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			break;
 		case Opt_alloc:
 			name = match_strdup(&args[0]);
 			if (!name)
@@ -1437,6 +1455,12 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 		return -EINVAL;
 	}
 
+	/* Not pass down write hints if the number of active logs is less
+	 * than NR_CURSEG_PERSIST_TYPE.
+	 */
+	if (F2FS_OPTION(sbi).active_logs != NR_CURSEG_PERSIST_TYPE)
+		F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
+
 	if (f2fs_sb_has_readonly(sbi) && !f2fs_readonly(sbi->sb)) {
 		f2fs_err(sbi, "Allow to mount readonly mode only");
 		return -EROFS;
@@ -2108,6 +2132,10 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 		seq_puts(seq, ",prjquota");
 #endif
 	f2fs_show_quota_options(seq, sbi->sb);
+	if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_USER)
+		seq_printf(seq, ",whint_mode=%s", "user-based");
+	else if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_FS)
+		seq_printf(seq, ",whint_mode=%s", "fs-based");
 
 	fscrypt_show_test_dummy_encryption(seq, ',', sbi->sb);
 
@@ -2177,6 +2205,7 @@ static void default_options(struct f2fs_sb_info *sbi, bool remount)
 		F2FS_OPTION(sbi).active_logs = NR_CURSEG_PERSIST_TYPE;
 
 	F2FS_OPTION(sbi).inline_xattr_size = DEFAULT_INLINE_XATTR_ADDRS;
+	F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
 	if (le32_to_cpu(F2FS_RAW_SUPER(sbi)->segment_count_main) <=
 							SMALL_VOLUME_SEGMENTS)
 		F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_REUSE;
@@ -2491,7 +2520,8 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 		need_stop_gc = true;
 	}
 
-	if (*flags & SB_RDONLY) {
+	if (*flags & SB_RDONLY ||
+	    F2FS_OPTION(sbi).whint_mode != org_mount_opt.whint_mode) {
 		sync_inodes_sb(sb);
 
 		set_sbi_flag(sbi, SBI_IS_DIRTY);

[PATCH v8 08/19] fs/f2fs: Restore support for tracing data lifetimes

[Bart Van Assche]

This patch restores code that was removed by commit 41d36a9f3e53 ("fs:
remove kiocb.ki_hint").

Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 include/trace/events/f2fs.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 793f82cc1515..d5a771a869b2 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -946,6 +946,7 @@ TRACE_EVENT(f2fs_direct_IO_enter,
 		__field(ino_t,	ino)
 		__field(loff_t,	ki_pos)
 		__field(int,	ki_flags)
+		__field(u16,	ki_hint)
 		__field(u16,	ki_ioprio)
 		__field(unsigned long,	len)
 		__field(int,	rw)
@@ -956,16 +957,19 @@ TRACE_EVENT(f2fs_direct_IO_enter,
 		__entry->ino		= inode->i_ino;
 		__entry->ki_pos		= iocb->ki_pos;
 		__entry->ki_flags	= iocb->ki_flags;
+		__entry->ki_hint	=
+			file_inode(iocb->ki_filp)->i_write_hint;
 		__entry->ki_ioprio	= iocb->ki_ioprio;
 		__entry->len		= len;
 		__entry->rw		= rw;
 	),
 
-	TP_printk("dev = (%d,%d), ino = %lu pos = %lld len = %lu ki_flags = %x ki_ioprio = %x rw = %d",
+	TP_printk("dev = (%d,%d), ino = %lu pos = %lld len = %lu ki_flags = %x ki_hint = %x ki_ioprio = %x rw = %d",
 		show_dev_ino(__entry),
 		__entry->ki_pos,
 		__entry->len,
 		__entry->ki_flags,
+		__entry->ki_hint,
 		__entry->ki_ioprio,
 		__entry->rw)
 );

[PATCH v8 09/19] scsi: core: Query the Block Limits Extension VPD page

[Bart Van Assche]

Parse the Reduced Stream Control Supported (RSCS) bit from the block
limits extension VPD page. The RSCS bit is defined in SBC-5 r05
(https://www.t10.org/cgi-bin/ac.pl?t=f&f=sbc5r05.pdf).

Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi.c        |  2 ++
 drivers/scsi/scsi_sysfs.c  | 10 ++++++++++
 drivers/scsi/sd.c          | 13 +++++++++++++
 drivers/scsi/sd.h          |  1 +
 include/scsi/scsi_device.h |  1 +
 5 files changed, 27 insertions(+)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 76d369343c7a..74cc3369dd8d 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -499,6 +499,8 @@ void scsi_attach_vpd(struct scsi_device *sdev)
 			scsi_update_vpd_page(sdev, 0xb1, &sdev->vpd_pgb1);
 		if (vpd_buf->data[i] == 0xb2)
 			scsi_update_vpd_page(sdev, 0xb2, &sdev->vpd_pgb2);
+		if (vpd_buf->data[i] == 0xb7)
+			scsi_update_vpd_page(sdev, 0xb7, &sdev->vpd_pgb7);
 	}
 	kfree(vpd_buf);
 }
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 24f6eefb6803..93652a786a46 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -449,6 +449,7 @@ static void scsi_device_dev_release(struct device *dev)
 	struct scsi_vpd *vpd_pg80 = NULL, *vpd_pg83 = NULL;
 	struct scsi_vpd *vpd_pg0 = NULL, *vpd_pg89 = NULL;
 	struct scsi_vpd *vpd_pgb0 = NULL, *vpd_pgb1 = NULL, *vpd_pgb2 = NULL;
+	struct scsi_vpd *vpd_pgb7 = NULL;
 	unsigned long flags;
 
 	might_sleep();
@@ -494,6 +495,8 @@ static void scsi_device_dev_release(struct device *dev)
 				       lockdep_is_held(&sdev->inquiry_mutex));
 	vpd_pgb2 = rcu_replace_pointer(sdev->vpd_pgb2, vpd_pgb2,
 				       lockdep_is_held(&sdev->inquiry_mutex));
+	vpd_pgb7 = rcu_replace_pointer(sdev->vpd_pgb7, vpd_pgb7,
+				       lockdep_is_held(&sdev->inquiry_mutex));
 	mutex_unlock(&sdev->inquiry_mutex);
 
 	if (vpd_pg0)
@@ -510,6 +513,8 @@ static void scsi_device_dev_release(struct device *dev)
 		kfree_rcu(vpd_pgb1, rcu);
 	if (vpd_pgb2)
 		kfree_rcu(vpd_pgb2, rcu);
+	if (vpd_pgb7)
+		kfree_rcu(vpd_pgb7, rcu);
 	kfree(sdev->inquiry);
 	kfree(sdev);
 
@@ -921,6 +926,7 @@ sdev_vpd_pg_attr(pg89);
 sdev_vpd_pg_attr(pgb0);
 sdev_vpd_pg_attr(pgb1);
 sdev_vpd_pg_attr(pgb2);
+sdev_vpd_pg_attr(pgb7);
 sdev_vpd_pg_attr(pg0);
 
 static ssize_t show_inquiry(struct file *filep, struct kobject *kobj,
@@ -1295,6 +1301,9 @@ static umode_t scsi_sdev_bin_attr_is_visible(struct kobject *kobj,
 	if (attr == &dev_attr_vpd_pgb2 && !sdev->vpd_pgb2)
 		return 0;
 
+	if (attr == &dev_attr_vpd_pgb7 && !sdev->vpd_pgb7)
+		return 0;
+
 	return S_IRUGO;
 }
 
@@ -1347,6 +1356,7 @@ static struct bin_attribute *scsi_sdev_bin_attrs[] = {
 	&dev_attr_vpd_pgb0,
 	&dev_attr_vpd_pgb1,
 	&dev_attr_vpd_pgb2,
+	&dev_attr_vpd_pgb7,
 	&dev_attr_inquiry,
 	NULL
 };
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 530918cbfce2..56c4310a741b 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3103,6 +3103,18 @@ static void sd_read_block_limits(struct scsi_disk *sdkp)
 	rcu_read_unlock();
 }
 
+/* Parse the Block Limits Extension VPD page (0xb7) */
+static void sd_read_block_limits_ext(struct scsi_disk *sdkp)
+{
+	struct scsi_vpd *vpd;
+
+	rcu_read_lock();
+	vpd = rcu_dereference(sdkp->device->vpd_pgb7);
+	if (vpd && vpd->len >= 2)
+		sdkp->rscs = vpd->data[5] & 1;
+	rcu_read_unlock();
+}
+
 /**
  * sd_read_block_characteristics - Query block dev. characteristics
  * @sdkp: disk to query
@@ -3457,6 +3469,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 		if (scsi_device_supports_vpd(sdp)) {
 			sd_read_block_provisioning(sdkp);
 			sd_read_block_limits(sdkp);
+			sd_read_block_limits_ext(sdkp);
 			sd_read_block_characteristics(sdkp);
 			sd_zbc_read_zones(sdkp, buffer);
 			sd_read_cpr(sdkp);
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 409dda5350d1..e4539122f2a2 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -151,6 +151,7 @@ struct scsi_disk {
 	unsigned	urswrz : 1;
 	unsigned	security : 1;
 	unsigned	ignore_medium_access_errors : 1;
+	bool		rscs : 1; /* reduced stream control support */
 };
 #define to_scsi_disk(obj) container_of(obj, struct scsi_disk, disk_dev)
 
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 10480eb582b2..a1588f3965f9 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -153,6 +153,7 @@ struct scsi_device {
 	struct scsi_vpd __rcu *vpd_pgb0;
 	struct scsi_vpd __rcu *vpd_pgb1;
 	struct scsi_vpd __rcu *vpd_pgb2;
+	struct scsi_vpd __rcu *vpd_pgb7;
 
 	struct scsi_target      *sdev_target;
 

[PATCH v8 10/19] scsi: scsi_proto: Add structures and constants related to I/O groups and streams

[Bart Van Assche]

Prepare for adding code that will query the I/O advice hints group
descriptors and for adding code that will retrieve the stream status.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/Kconfig           |  5 +++
 drivers/scsi/Makefile          |  2 +
 drivers/scsi/scsi_proto_test.c | 56 ++++++++++++++++++++++++
 include/scsi/scsi_proto.h      | 78 ++++++++++++++++++++++++++++++++++
 4 files changed, 141 insertions(+)
 create mode 100644 drivers/scsi/scsi_proto_test.c

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index addac7fbe37b..83b542abfc29 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -232,6 +232,11 @@ config SCSI_SCAN_ASYNC
 	  Note that this setting also affects whether resuming from
 	  system suspend will be performed asynchronously.
 
+config SCSI_PROTO_TEST
+	tristate "scsi_proto.h unit tests" if !KUNIT_ALL_TESTS
+	depends on SCSI && KUNIT
+	default KUNIT_ALL_TESTS
+
 menu "SCSI Transports"
 	depends on SCSI
 
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index f055bfd54a68..1313ddf2fd1a 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -24,6 +24,8 @@ obj-$(CONFIG_SCSI_COMMON)	+= scsi_common.o
 
 obj-$(CONFIG_RAID_ATTRS)	+= raid_class.o
 
+obj-$(CONFIG_SCSI_PROTO_TEST)	+= scsi_proto_test.o
+
 # --- NOTE ORDERING HERE ---
 # For kernel non-modular link, transport attributes need to
 # be initialised before drivers
diff --git a/drivers/scsi/scsi_proto_test.c b/drivers/scsi/scsi_proto_test.c
new file mode 100644
index 000000000000..7fa0a78a2ad1
--- /dev/null
+++ b/drivers/scsi/scsi_proto_test.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Google LLC
+ */
+#include <kunit/test.h>
+#include <asm-generic/unaligned.h>
+#include <scsi/scsi_proto.h>
+
+static void test_scsi_proto(struct kunit *test)
+{
+	static const union {
+		struct scsi_io_group_descriptor desc;
+		u8 arr[sizeof(struct scsi_io_group_descriptor)];
+	} d = { .arr = { 0x45, 0, 0, 0, 0xb0, 0xe4, 0xe3 } };
+	KUNIT_EXPECT_EQ(test, d.desc.io_advice_hints_mode + 0, 1);
+	KUNIT_EXPECT_EQ(test, d.desc.st_enble + 0, 1);
+	KUNIT_EXPECT_EQ(test, d.desc.cs_enble + 0, 0);
+	KUNIT_EXPECT_EQ(test, d.desc.ic_enable + 0, 1);
+	KUNIT_EXPECT_EQ(test, d.desc.acdlu + 0, 1);
+	KUNIT_EXPECT_EQ(test, d.desc.rlbsr + 0, 3);
+	KUNIT_EXPECT_EQ(test, d.desc.lbm_descriptor_type + 0, 0);
+	KUNIT_EXPECT_EQ(test, d.desc.params[0] + 0, 0xe4);
+	KUNIT_EXPECT_EQ(test, d.desc.params[1] + 0, 0xe3);
+
+	static const union {
+		struct scsi_stream_status s;
+		u8 arr[sizeof(struct scsi_stream_status)];
+	} ss = { .arr = { 0x80, 0, 0x12, 0x34, 0x3f } };
+	KUNIT_EXPECT_EQ(test, ss.s.perm + 0, 1);
+	KUNIT_EXPECT_EQ(test, get_unaligned_be16(&ss.s.stream_identifier),
+			0x1234);
+	KUNIT_EXPECT_EQ(test, ss.s.rel_lifetime + 0, 0x3f);
+
+	static const union {
+		struct scsi_stream_status_header h;
+		u8 arr[sizeof(struct scsi_stream_status_header)];
+	} sh = { .arr = { 1, 2, 3, 4, 0, 0, 5, 6 } };
+	KUNIT_EXPECT_EQ(test, get_unaligned_be32(&sh.h.len), 0x1020304);
+	KUNIT_EXPECT_EQ(test, get_unaligned_be16(&sh.h.number_of_open_streams),
+			0x506);
+}
+
+static struct kunit_case scsi_proto_test_cases[] = {
+	KUNIT_CASE(test_scsi_proto),
+	{}
+};
+
+static struct kunit_suite scsi_proto_test_suite = {
+	.name = "scsi_proto",
+	.test_cases = scsi_proto_test_cases,
+};
+kunit_test_suite(scsi_proto_test_suite);
+
+MODULE_DESCRIPTION("<scsi/scsi_proto.h> unit tests");
+MODULE_AUTHOR("Bart Van Assche");
+MODULE_LICENSE("GPL");
diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h
index 07d65c1f59db..843106e1109f 100644
--- a/include/scsi/scsi_proto.h
+++ b/include/scsi/scsi_proto.h
@@ -10,6 +10,7 @@
 #ifndef _SCSI_PROTO_H_
 #define _SCSI_PROTO_H_
 
+#include <linux/build_bug.h>
 #include <linux/types.h>
 
 /*
@@ -126,6 +127,7 @@
 #define	SAI_READ_CAPACITY_16  0x10
 #define SAI_GET_LBA_STATUS    0x12
 #define SAI_REPORT_REFERRALS  0x13
+#define SAI_GET_STREAM_STATUS 0x16
 /* values for maintenance in */
 #define MI_REPORT_IDENTIFYING_INFORMATION 0x05
 #define MI_REPORT_TARGET_PGS  0x0a
@@ -275,6 +277,82 @@ struct scsi_lun {
 	__u8 scsi_lun[8];
 };
 
+/* SBC-5 IO advice hints group descriptor */
+struct scsi_io_group_descriptor {
+#if defined(__BIG_ENDIAN)
+	u8 io_advice_hints_mode: 2;
+	u8 reserved1: 3;
+	u8 st_enble: 1;
+	u8 cs_enble: 1;
+	u8 ic_enable: 1;
+#elif defined(__LITTLE_ENDIAN)
+	u8 ic_enable: 1;
+	u8 cs_enble: 1;
+	u8 st_enble: 1;
+	u8 reserved1: 3;
+	u8 io_advice_hints_mode: 2;
+#else
+#error
+#endif
+	u8 reserved2[3];
+	/* Logical block markup descriptor */
+#if defined(__BIG_ENDIAN)
+	u8 acdlu: 1;
+	u8 reserved3: 1;
+	u8 rlbsr: 2;
+	u8 lbm_descriptor_type: 4;
+#elif defined(__LITTLE_ENDIAN)
+	u8 lbm_descriptor_type: 4;
+	u8 rlbsr: 2;
+	u8 reserved3: 1;
+	u8 acdlu: 1;
+#else
+#error
+#endif
+	u8 params[2];
+	u8 reserved4;
+	u8 reserved5[8];
+};
+
+static_assert(sizeof(struct scsi_io_group_descriptor) == 16);
+
+/* SCSI stream status descriptor */
+struct scsi_stream_status {
+#if defined(__BIG_ENDIAN)
+	u8 perm: 1;
+	u8 reserved1: 7;
+#elif defined(__LITTLE_ENDIAN)
+	u8 reserved1: 7;
+	u8 perm: 1;
+#else
+#error
+#endif
+	u8 reserved2;
+	__be16 stream_identifier;
+#if defined(__BIG_ENDIAN)
+	u8 reserved3: 2;
+	u8 rel_lifetime: 6;
+#elif defined(__LITTLE_ENDIAN)
+	u8 rel_lifetime: 6;
+	u8 reserved3: 2;
+#else
+#error
+#endif
+	u8 reserved4[3];
+};
+
+static_assert(sizeof(struct scsi_stream_status) == 8);
+
+/* GET STREAM STATUS parameter data */
+struct scsi_stream_status_header {
+	__be32 len;	/* length in bytes of stream_status[] array. */
+	u16 reserved;
+	__be16 number_of_open_streams;
+	DECLARE_FLEX_ARRAY(struct scsi_stream_status, stream_status);
+};
+
+static_assert(sizeof(struct scsi_stream_status_header) == 8);
+
 /* SPC asymmetric access states */
 #define SCSI_ACCESS_STATE_OPTIMAL     0x00
 #define SCSI_ACCESS_STATE_ACTIVE      0x01

[PATCH v8 11/19] scsi: sd: Translate data lifetime information

[Bart Van Assche]

Recently T10 standardized SBC constrained streams. This mechanism allows
to pass data lifetime information to SCSI devices in the group number
field. Add support for translating write hint information into a
permanent stream number in the sd driver. Use WRITE(10) instead of
WRITE(6) if data lifetime information is present because the WRITE(6)
command does not have a GROUP NUMBER field.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/sd.c | 98 +++++++++++++++++++++++++++++++++++++++++++++--
 drivers/scsi/sd.h |  4 +-
 2 files changed, 98 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 56c4310a741b..3037f35a1b79 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -47,6 +47,7 @@
 #include <linux/blkpg.h>
 #include <linux/blk-pm.h>
 #include <linux/delay.h>
+#include <linux/rw_hint.h>
 #include <linux/major.h>
 #include <linux/mutex.h>
 #include <linux/string_helpers.h>
@@ -1080,12 +1081,38 @@ static blk_status_t sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
 	return BLK_STS_OK;
 }
 
+/**
+ * sd_group_number() - Compute the GROUP NUMBER field
+ * @cmd: SCSI command for which to compute the value of the six-bit GROUP NUMBER
+ *	field.
+ *
+ * From SBC-5 r05 (https://www.t10.org/cgi-bin/ac.pl?t=f&f=sbc5r05.pdf):
+ * 0: no relative lifetime.
+ * 1: shortest relative lifetime.
+ * 2: second shortest relative lifetime.
+ * 3 - 0x3d: intermediate relative lifetimes.
+ * 0x3e: second longest relative lifetime.
+ * 0x3f: longest relative lifetime.
+ */
+static u8 sd_group_number(struct scsi_cmnd *cmd)
+{
+	const struct request *rq = scsi_cmd_to_rq(cmd);
+	struct scsi_disk *sdkp = scsi_disk(rq->q->disk);
+
+	if (!sdkp->rscs)
+		return 0;
+
+	return min3((u32)rq->write_hint, (u32)sdkp->permanent_stream_count,
+		    0x3fu);
+}
+
 static blk_status_t sd_setup_rw32_cmnd(struct scsi_cmnd *cmd, bool write,
 				       sector_t lba, unsigned int nr_blocks,
 				       unsigned char flags, unsigned int dld)
 {
 	cmd->cmd_len = SD_EXT_CDB_SIZE;
 	cmd->cmnd[0]  = VARIABLE_LENGTH_CMD;
+	cmd->cmnd[6]  = sd_group_number(cmd);
 	cmd->cmnd[7]  = 0x18; /* Additional CDB len */
 	cmd->cmnd[9]  = write ? WRITE_32 : READ_32;
 	cmd->cmnd[10] = flags;
@@ -1104,7 +1131,7 @@ static blk_status_t sd_setup_rw16_cmnd(struct scsi_cmnd *cmd, bool write,
 	cmd->cmd_len  = 16;
 	cmd->cmnd[0]  = write ? WRITE_16 : READ_16;
 	cmd->cmnd[1]  = flags | ((dld >> 2) & 0x01);
-	cmd->cmnd[14] = (dld & 0x03) << 6;
+	cmd->cmnd[14] = ((dld & 0x03) << 6) | sd_group_number(cmd);
 	cmd->cmnd[15] = 0;
 	put_unaligned_be64(lba, &cmd->cmnd[2]);
 	put_unaligned_be32(nr_blocks, &cmd->cmnd[10]);
@@ -1119,7 +1146,7 @@ static blk_status_t sd_setup_rw10_cmnd(struct scsi_cmnd *cmd, bool write,
 	cmd->cmd_len = 10;
 	cmd->cmnd[0] = write ? WRITE_10 : READ_10;
 	cmd->cmnd[1] = flags;
-	cmd->cmnd[6] = 0;
+	cmd->cmnd[6] = sd_group_number(cmd);
 	cmd->cmnd[9] = 0;
 	put_unaligned_be32(lba, &cmd->cmnd[2]);
 	put_unaligned_be16(nr_blocks, &cmd->cmnd[7]);
@@ -1256,7 +1283,7 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
 		ret = sd_setup_rw16_cmnd(cmd, write, lba, nr_blocks,
 					 protect | fua, dld);
 	} else if ((nr_blocks > 0xff) || (lba > 0x1fffff) ||
-		   sdp->use_10_for_rw || protect) {
+		   sdp->use_10_for_rw || protect || rq->write_hint) {
 		ret = sd_setup_rw10_cmnd(cmd, write, lba, nr_blocks,
 					 protect | fua);
 	} else {
@@ -2996,6 +3023,70 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 	sdkp->DPOFUA = 0;
 }
 
+static bool sd_is_perm_stream(struct scsi_disk *sdkp, unsigned int stream_id)
+{
+	u8 cdb[16] = { SERVICE_ACTION_IN_16, SAI_GET_STREAM_STATUS };
+	struct {
+		struct scsi_stream_status_header h;
+		struct scsi_stream_status s;
+	} buf;
+	struct scsi_device *sdev = sdkp->device;
+	struct scsi_sense_hdr sshdr;
+	const struct scsi_exec_args exec_args = {
+		.sshdr = &sshdr,
+	};
+	int res;
+
+	put_unaligned_be16(stream_id, &cdb[4]);
+	put_unaligned_be32(sizeof(buf), &cdb[10]);
+
+	res = scsi_execute_cmd(sdev, cdb, REQ_OP_DRV_IN, &buf, sizeof(buf),
+			       SD_TIMEOUT, sdkp->max_retries, &exec_args);
+	if (res < 0)
+		return false;
+	if (scsi_status_is_check_condition(res) && scsi_sense_valid(&sshdr))
+		sd_print_sense_hdr(sdkp, &sshdr);
+	if (res)
+		return false;
+	if (get_unaligned_be32(&buf.h.len) < sizeof(struct scsi_stream_status))
+		return false;
+	return buf.h.stream_status[0].perm;
+}
+
+static void sd_read_io_hints(struct scsi_disk *sdkp, unsigned char *buffer)
+{
+	struct scsi_device *sdp = sdkp->device;
+	const struct scsi_io_group_descriptor *desc, *start, *end;
+	struct scsi_sense_hdr sshdr;
+	struct scsi_mode_data data;
+	int res;
+
+	res = scsi_mode_sense(sdp, /*dbd=*/0x8, /*modepage=*/0x0a,
+			      /*subpage=*/0x05, buffer, SD_BUF_SIZE, SD_TIMEOUT,
+			      sdkp->max_retries, &data, &sshdr);
+	if (res < 0)
+		return;
+	start = (void *)buffer + data.header_length + 16;
+	end = (void *)buffer + ALIGN_DOWN(data.header_length + data.length,
+					  sizeof(*end));
+	/*
+	 * From "SBC-5 Constrained Streams with Data Lifetimes": Device severs
+	 * should assign the lowest numbered stream identifiers to permanent
+	 * streams.
+	 */
+	for (desc = start; desc < end; desc++)
+		if (!desc->st_enble || !sd_is_perm_stream(sdkp, desc - start))
+			break;
+	sdkp->permanent_stream_count = desc - start;
+	if (sdkp->rscs && sdkp->permanent_stream_count < 2)
+		sd_printk(KERN_INFO, sdkp,
+			  "Unexpected: RSCS has been set and the permanent stream count is %u\n",
+			  sdkp->permanent_stream_count);
+	else if (sdkp->permanent_stream_count)
+		sd_printk(KERN_INFO, sdkp, "permanent stream count = %d\n",
+			  sdkp->permanent_stream_count);
+}
+
 /*
  * The ATO bit indicates whether the DIF application tag is available
  * for use by the operating system.
@@ -3479,6 +3570,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 
 		sd_read_write_protect_flag(sdkp, buffer);
 		sd_read_cache_type(sdkp, buffer);
+		sd_read_io_hints(sdkp, buffer);
 		sd_read_app_tag_own(sdkp, buffer);
 		sd_read_write_same(sdkp, buffer);
 		sd_read_security(sdkp, buffer);
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index e4539122f2a2..5c4285a582b2 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -125,6 +125,8 @@ struct scsi_disk {
 	unsigned int	physical_block_size;
 	unsigned int	max_medium_access_timeouts;
 	unsigned int	medium_access_timed_out;
+			/* number of permanent streams */
+	u16		permanent_stream_count;
 	u8		media_present;
 	u8		write_prot;
 	u8		protection_type;/* Data Integrity Field */
@@ -151,7 +153,7 @@ struct scsi_disk {
 	unsigned	urswrz : 1;
 	unsigned	security : 1;
 	unsigned	ignore_medium_access_errors : 1;
-	bool		rscs : 1; /* reduced stream control support */
+	unsigned	rscs : 1; /* reduced stream control support */
 };
 #define to_scsi_disk(obj) container_of(obj, struct scsi_disk, disk_dev)
 

[PATCH v8 12/19] scsi: scsi_debug: Reduce code duplication

[Bart Van Assche]

All VPD pages have the page code in byte one. Reduce code duplication by
storing the VPD page code once.

Reviewed-by: Avri Altman <avri.altman@wdc.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 67922e2c4c19..5cf337ba9c19 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1909,7 +1909,8 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 		u32 len;
 		char lu_id_str[6];
 		int host_no = devip->sdbg_host->shost->host_no;
-		
+
+		arr[1] = cmd[2];
 		port_group_id = (((host_no + 1) & 0x7f) << 8) +
 		    (devip->channel & 0x7f);
 		if (sdebug_vpd_use_hostno == 0)
@@ -1920,7 +1921,6 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 				 (devip->target * 1000) - 3;
 		len = scnprintf(lu_id_str, 6, "%d", lu_id_num);
 		if (0 == cmd[2]) { /* supported vital product data pages */
-			arr[1] = cmd[2];	/*sanity */
 			n = 4;
 			arr[n++] = 0x0;   /* this page */
 			arr[n++] = 0x80;  /* unit serial number */
@@ -1941,23 +1941,18 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 			}
 			arr[3] = n - 4;	  /* number of supported VPD pages */
 		} else if (0x80 == cmd[2]) { /* unit serial number */
-			arr[1] = cmd[2];	/*sanity */
 			arr[3] = len;
 			memcpy(&arr[4], lu_id_str, len);
 		} else if (0x83 == cmd[2]) { /* device identification */
-			arr[1] = cmd[2];	/*sanity */
 			arr[3] = inquiry_vpd_83(&arr[4], port_group_id,
 						target_dev_id, lu_id_num,
 						lu_id_str, len,
 						&devip->lu_name);
 		} else if (0x84 == cmd[2]) { /* Software interface ident. */
-			arr[1] = cmd[2];	/*sanity */
 			arr[3] = inquiry_vpd_84(&arr[4]);
 		} else if (0x85 == cmd[2]) { /* Management network addresses */
-			arr[1] = cmd[2];	/*sanity */
 			arr[3] = inquiry_vpd_85(&arr[4]);
 		} else if (0x86 == cmd[2]) { /* extended inquiry */
-			arr[1] = cmd[2];	/*sanity */
 			arr[3] = 0x3c;	/* number of following entries */
 			if (sdebug_dif == T10_PI_TYPE3_PROTECTION)
 				arr[4] = 0x4;	/* SPT: GRD_CHK:1 */
@@ -1967,30 +1962,23 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 				arr[4] = 0x0;   /* no protection stuff */
 			arr[5] = 0x7;   /* head of q, ordered + simple q's */
 		} else if (0x87 == cmd[2]) { /* mode page policy */
-			arr[1] = cmd[2];	/*sanity */
 			arr[3] = 0x8;	/* number of following entries */
 			arr[4] = 0x2;	/* disconnect-reconnect mp */
 			arr[6] = 0x80;	/* mlus, shared */
 			arr[8] = 0x18;	 /* protocol specific lu */
 			arr[10] = 0x82;	 /* mlus, per initiator port */
 		} else if (0x88 == cmd[2]) { /* SCSI Ports */
-			arr[1] = cmd[2];	/*sanity */
 			arr[3] = inquiry_vpd_88(&arr[4], target_dev_id);
 		} else if (is_disk_zbc && 0x89 == cmd[2]) { /* ATA info */
-			arr[1] = cmd[2];        /*sanity */
 			n = inquiry_vpd_89(&arr[4]);
 			put_unaligned_be16(n, arr + 2);
 		} else if (is_disk_zbc && 0xb0 == cmd[2]) { /* Block limits */
-			arr[1] = cmd[2];        /*sanity */
 			arr[3] = inquiry_vpd_b0(&arr[4]);
 		} else if (is_disk_zbc && 0xb1 == cmd[2]) { /* Block char. */
-			arr[1] = cmd[2];        /*sanity */
 			arr[3] = inquiry_vpd_b1(devip, &arr[4]);
 		} else if (is_disk && 0xb2 == cmd[2]) { /* LB Prov. */
-			arr[1] = cmd[2];        /*sanity */
 			arr[3] = inquiry_vpd_b2(&arr[4]);
 		} else if (is_zbc && cmd[2] == 0xb6) { /* ZB dev. charact. */
-			arr[1] = cmd[2];        /*sanity */
 			arr[3] = inquiry_vpd_b6(devip, &arr[4]);
 		} else {
 			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, -1);

[PATCH v8 13/19] scsi: scsi_debug: Support the block limits extension VPD page

[Bart Van Assche]

From SBC-5 r05:

"Reduced stream control:
a) reduces the maximum number of streams that the device server supports;
   and
b) increases the number of write commands that are able to specify a stream
   to be written in any write command that contains the GROUP NUMBER field
   in its CDB.

If the RSCS bit (see 6.6.5) is set to one, then the device server shall:
a) support per group stream identifier usage as described in 4.32.2;
b) support the IO Advice Hints Grouping mode page (see 6.5.7); and
c) set the MAXIMUM NUMBER OF STREAMS field (see 6.6.5) to a value that is
   less than 64.

Device servers that set the RSCS bit to one may support other features
(e.g., permanent streams (see 4.32.4)).

4.32.4 Permanent streams

A permanent stream is a stream for which the device server does not allow
closing or otherwise modifying the configuration of that stream. The PERM
bit (see 5.9.2.3) indicates whether a stream is a permanent stream. If a
STREAM CONTROL command (see 5.32) specifies the closing of a permanent
stream, the device server terminates that command with CHECK CONDITION
status instead of closing the specified stream. A permanent stream is always
an open stream. Device severs should assign the lowest numbered stream
identifiers to permanent streams."

Report that reduced stream control is supported.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 5cf337ba9c19..39f8ae4dce82 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1873,6 +1873,19 @@ static int inquiry_vpd_b6(struct sdebug_dev_info *devip, unsigned char *arr)
 	return 0x3c;
 }
 
+#define SDEBUG_BLE_LEN_AFTER_B4 28	/* thus vpage 32 bytes long */
+
+enum { MAXIMUM_NUMBER_OF_STREAMS = 6, PERMANENT_STREAM_COUNT = 5 };
+
+/* Block limits extension VPD page (SBC-4) */
+static int inquiry_vpd_b7(unsigned char *arrb4)
+{
+	memset(arrb4, 0, SDEBUG_BLE_LEN_AFTER_B4);
+	arrb4[1] = 1; /* Reduced stream control support (RSCS) */
+	put_unaligned_be16(MAXIMUM_NUMBER_OF_STREAMS, &arrb4[2]);
+	return SDEBUG_BLE_LEN_AFTER_B4;
+}
+
 #define SDEBUG_LONG_INQ_SZ 96
 #define SDEBUG_MAX_INQ_ARR_SZ 584
 
@@ -1938,6 +1951,7 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 					arr[n++] = 0xb2;  /* LB Provisioning */
 				if (is_zbc)
 					arr[n++] = 0xb6;  /* ZB dev. char. */
+				arr[n++] = 0xb7;  /* Block limits extension */
 			}
 			arr[3] = n - 4;	  /* number of supported VPD pages */
 		} else if (0x80 == cmd[2]) { /* unit serial number */
@@ -1980,6 +1994,8 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 			arr[3] = inquiry_vpd_b2(&arr[4]);
 		} else if (is_zbc && cmd[2] == 0xb6) { /* ZB dev. charact. */
 			arr[3] = inquiry_vpd_b6(devip, &arr[4]);
+		} else if (cmd[2] == 0xb7) { /* block limits extension page */
+			arr[3] = inquiry_vpd_b7(&arr[4]);
 		} else {
 			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, -1);
 			kfree(arr);

[PATCH v8 14/19] scsi: scsi_debug: Rework page code error handling

[Bart Van Assche]

Instead of tracking whether or not the page code is valid in a boolean
variable, jump to error handling code if an unsupported page code is
encountered.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 39f8ae4dce82..b646c5320c63 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -2650,7 +2650,7 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 	unsigned char *ap;
 	unsigned char arr[SDEBUG_MAX_MSENSE_SZ];
 	unsigned char *cmd = scp->cmnd;
-	bool dbd, llbaa, msense_6, is_disk, is_zbc, bad_pcode;
+	bool dbd, llbaa, msense_6, is_disk, is_zbc;
 
 	dbd = !!(cmd[1] & 0x8);		/* disable block descriptors */
 	pcontrol = (cmd[2] & 0xc0) >> 6;
@@ -2714,7 +2714,6 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
 		return check_condition_result;
 	}
-	bad_pcode = false;
 
 	switch (pcode) {
 	case 0x1:	/* Read-Write error recovery page, direct access */
@@ -2729,15 +2728,17 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		if (is_disk) {
 			len = resp_format_pg(ap, pcontrol, target);
 			offset += len;
-		} else
-			bad_pcode = true;
+		} else {
+			goto bad_pcode;
+		}
 		break;
 	case 0x8:	/* Caching page, direct access */
 		if (is_disk || is_zbc) {
 			len = resp_caching_pg(ap, pcontrol, target);
 			offset += len;
-		} else
-			bad_pcode = true;
+		} else {
+			goto bad_pcode;
+		}
 		break;
 	case 0xa:	/* Control Mode page, all devices */
 		len = resp_ctrl_m_pg(ap, pcontrol, target);
@@ -2790,18 +2791,17 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		}
 		break;
 	default:
-		bad_pcode = true;
-		break;
-	}
-	if (bad_pcode) {
-		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
-		return check_condition_result;
+		goto bad_pcode;
 	}
 	if (msense_6)
 		arr[0] = offset - 1;
 	else
 		put_unaligned_be16((offset - 2), arr + 0);
 	return fill_from_dev_buffer(scp, arr, min_t(u32, alloc_len, offset));
+
+bad_pcode:
+	mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
+	return check_condition_result;
 }
 
 #define SDEBUG_MAX_MSELECT_SZ 512

[PATCH v8 15/19] scsi: scsi_debug: Rework subpage code error handling

[Bart Van Assche]

Move the subpage code checks into the switch statement to make it easier
to add support for new page code / subpage code combinations.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 70 ++++++++++++++++++++-------------------
 1 file changed, 36 insertions(+), 34 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index b646c5320c63..cadd130d6b53 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -2709,22 +2709,22 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		ap = arr + offset;
 	}
 
-	if ((subpcode > 0x0) && (subpcode < 0xff) && (0x19 != pcode)) {
-		/* TODO: Control Extension page */
-		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
-		return check_condition_result;
-	}
-
 	switch (pcode) {
 	case 0x1:	/* Read-Write error recovery page, direct access */
+		if (subpcode > 0x0 && subpcode < 0xff)
+			goto bad_subpcode;
 		len = resp_err_recov_pg(ap, pcontrol, target);
 		offset += len;
 		break;
 	case 0x2:	/* Disconnect-Reconnect page, all devices */
+		if (subpcode > 0x0 && subpcode < 0xff)
+			goto bad_subpcode;
 		len = resp_disconnect_pg(ap, pcontrol, target);
 		offset += len;
 		break;
 	case 0x3:       /* Format device page, direct access */
+		if (subpcode > 0x0 && subpcode < 0xff)
+			goto bad_subpcode;
 		if (is_disk) {
 			len = resp_format_pg(ap, pcontrol, target);
 			offset += len;
@@ -2733,6 +2733,8 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		}
 		break;
 	case 0x8:	/* Caching page, direct access */
+		if (subpcode > 0x0 && subpcode < 0xff)
+			goto bad_subpcode;
 		if (is_disk || is_zbc) {
 			len = resp_caching_pg(ap, pcontrol, target);
 			offset += len;
@@ -2741,14 +2743,14 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		}
 		break;
 	case 0xa:	/* Control Mode page, all devices */
+		if (subpcode > 0x0 && subpcode < 0xff)
+			goto bad_subpcode;
 		len = resp_ctrl_m_pg(ap, pcontrol, target);
 		offset += len;
 		break;
 	case 0x19:	/* if spc==1 then sas phy, control+discover */
-		if ((subpcode > 0x2) && (subpcode < 0xff)) {
-			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
-			return check_condition_result;
-		}
+		if (subpcode > 0x2 && subpcode < 0xff)
+			goto bad_subpcode;
 		len = 0;
 		if ((0x0 == subpcode) || (0xff == subpcode))
 			len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
@@ -2760,35 +2762,31 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		offset += len;
 		break;
 	case 0x1c:	/* Informational Exceptions Mode page, all devices */
+		if (subpcode > 0x0 && subpcode < 0xff)
+			goto bad_subpcode;
 		len = resp_iec_m_pg(ap, pcontrol, target);
 		offset += len;
 		break;
 	case 0x3f:	/* Read all Mode pages */
-		if ((0 == subpcode) || (0xff == subpcode)) {
-			len = resp_err_recov_pg(ap, pcontrol, target);
-			len += resp_disconnect_pg(ap + len, pcontrol, target);
-			if (is_disk) {
-				len += resp_format_pg(ap + len, pcontrol,
-						      target);
-				len += resp_caching_pg(ap + len, pcontrol,
-						       target);
-			} else if (is_zbc) {
-				len += resp_caching_pg(ap + len, pcontrol,
-						       target);
-			}
-			len += resp_ctrl_m_pg(ap + len, pcontrol, target);
-			len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
-			if (0xff == subpcode) {
-				len += resp_sas_pcd_m_spg(ap + len, pcontrol,
-						  target, target_dev_id);
-				len += resp_sas_sha_m_spg(ap + len, pcontrol);
-			}
-			len += resp_iec_m_pg(ap + len, pcontrol, target);
-			offset += len;
-		} else {
-			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
-			return check_condition_result;
+		if (subpcode > 0x0 && subpcode < 0xff)
+			goto bad_subpcode;
+		len = resp_err_recov_pg(ap, pcontrol, target);
+		len += resp_disconnect_pg(ap + len, pcontrol, target);
+		if (is_disk) {
+			len += resp_format_pg(ap + len, pcontrol, target);
+			len += resp_caching_pg(ap + len, pcontrol, target);
+		} else if (is_zbc) {
+			len += resp_caching_pg(ap + len, pcontrol, target);
+		}
+		len += resp_ctrl_m_pg(ap + len, pcontrol, target);
+		len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
+		if (0xff == subpcode) {
+			len += resp_sas_pcd_m_spg(ap + len, pcontrol, target,
+						  target_dev_id);
+			len += resp_sas_sha_m_spg(ap + len, pcontrol);
 		}
+		len += resp_iec_m_pg(ap + len, pcontrol, target);
+		offset += len;
 		break;
 	default:
 		goto bad_pcode;
@@ -2802,6 +2800,10 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 bad_pcode:
 	mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
 	return check_condition_result;
+
+bad_subpcode:
+	mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
+	return check_condition_result;
 }
 
 #define SDEBUG_MAX_MSELECT_SZ 512

[PATCH v8 16/19] scsi: scsi_debug: Allocate the MODE SENSE response from the heap

[Bart Van Assche]

Make the MODE SENSE response buffer larger and allocate it from the heap.
This patch prepares for adding support for the IO Advice Hints Grouping
mode page.

Suggested-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index cadd130d6b53..4181d0d81224 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -43,6 +43,7 @@
 #include <linux/prefetch.h>
 #include <linux/debugfs.h>
 #include <linux/async.h>
+#include <linux/cleanup.h>
 
 #include <net/checksum.h>
 
@@ -2637,7 +2638,8 @@ static int resp_sas_sha_m_spg(unsigned char *p, int pcontrol)
 	return sizeof(sas_sha_m_pg);
 }
 
-#define SDEBUG_MAX_MSENSE_SZ 256
+/* PAGE_SIZE is more than necessary but provides room for future expansion. */
+#define SDEBUG_MAX_MSENSE_SZ PAGE_SIZE
 
 static int resp_mode_sense(struct scsi_cmnd *scp,
 			   struct sdebug_dev_info *devip)
@@ -2648,10 +2650,13 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 	int target_dev_id;
 	int target = scp->device->id;
 	unsigned char *ap;
-	unsigned char arr[SDEBUG_MAX_MSENSE_SZ];
+	unsigned char *arr __free(kfree);
 	unsigned char *cmd = scp->cmnd;
 	bool dbd, llbaa, msense_6, is_disk, is_zbc;
 
+	arr = kzalloc(SDEBUG_MAX_MSENSE_SZ, GFP_ATOMIC);
+	if (!arr)
+		return -ENOMEM;
 	dbd = !!(cmd[1] & 0x8);		/* disable block descriptors */
 	pcontrol = (cmd[2] & 0xc0) >> 6;
 	pcode = cmd[2] & 0x3f;

[PATCH v8 17/19] scsi: scsi_debug: Implement the IO Advice Hints Grouping mode page

[Bart Van Assche]

Implement an IO Advice Hints Grouping mode page with three permanent
streams. A permanent stream is a stream for which the device server does
not allow closing or otherwise modifying the configuration of that
stream. The stream identifier enable (ST_ENBLE) bit specifies whether
the stream identifier may be used in the GROUP NUMBER field of SCSI
WRITE commands.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 61 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 58 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 4181d0d81224..4e18265a05da 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1975,7 +1975,11 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 				arr[4] = 0x5;   /* SPT: GRD_CHK:1, REF_CHK:1 */
 			else
 				arr[4] = 0x0;   /* no protection stuff */
-			arr[5] = 0x7;   /* head of q, ordered + simple q's */
+			/*
+			 * GROUP_SUP=1; HEADSUP=1 (HEAD OF QUEUE); ORDSUP=1
+			 * (ORDERED queuing); SIMPSUP=1 (SIMPLE queuing).
+			 */
+			arr[5] = 0x17;
 		} else if (0x87 == cmd[2]) { /* mode page policy */
 			arr[3] = 0x8;	/* number of following entries */
 			arr[4] = 0x2;	/* disconnect-reconnect mp */
@@ -2565,6 +2569,40 @@ static int resp_ctrl_m_pg(unsigned char *p, int pcontrol, int target)
 	return sizeof(ctrl_m_pg);
 }
 
+/* IO Advice Hints Grouping mode page */
+static int resp_grouping_m_pg(unsigned char *p, int pcontrol, int target)
+{
+	/* IO Advice Hints Grouping mode page */
+	struct grouping_m_pg {
+		u8 page_code;	/* OR 0x40 when subpage_code > 0 */
+		u8 subpage_code;
+		__be16 page_length;
+		u8 reserved[12];
+		struct scsi_io_group_descriptor descr[MAXIMUM_NUMBER_OF_STREAMS];
+	};
+	static const struct grouping_m_pg gr_m_pg = {
+		.page_code = 0xa | 0x40,
+		.subpage_code = 5,
+		.page_length = cpu_to_be16(sizeof(gr_m_pg) - 4),
+		.descr = {
+			{ .st_enble = 1 },
+			{ .st_enble = 1 },
+			{ .st_enble = 1 },
+			{ .st_enble = 1 },
+			{ .st_enble = 1 },
+			{ .st_enble = 0 },
+		}
+	};
+
+	BUILD_BUG_ON(sizeof(struct grouping_m_pg) !=
+		     16 + MAXIMUM_NUMBER_OF_STREAMS * 16);
+	memcpy(p, &gr_m_pg, sizeof(gr_m_pg));
+	if (1 == pcontrol) {
+		/* There are no changeable values so clear from byte 4 on. */
+		memset(p + 4, 0, sizeof(gr_m_pg) - 4);
+	}
+	return sizeof(gr_m_pg);
+}
 
 static int resp_iec_m_pg(unsigned char *p, int pcontrol, int target)
 {	/* Informational Exceptions control mode page for mode_sense */
@@ -2714,6 +2752,10 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		ap = arr + offset;
 	}
 
+	/*
+	 * N.B. If len>0 before resp_*_pg() call, then form of that call should be:
+	 *        len += resp_*_pg(ap + len, pcontrol, target);
+	 */
 	switch (pcode) {
 	case 0x1:	/* Read-Write error recovery page, direct access */
 		if (subpcode > 0x0 && subpcode < 0xff)
@@ -2748,9 +2790,20 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		}
 		break;
 	case 0xa:	/* Control Mode page, all devices */
-		if (subpcode > 0x0 && subpcode < 0xff)
+		switch (subpcode) {
+		case 0:
+			len = resp_ctrl_m_pg(ap, pcontrol, target);
+			break;
+		case 0x05:
+			len = resp_grouping_m_pg(ap, pcontrol, target);
+			break;
+		case 0xff:
+			len = resp_ctrl_m_pg(ap, pcontrol, target);
+			len += resp_grouping_m_pg(ap + len, pcontrol, target);
+			break;
+		default:
 			goto bad_subpcode;
-		len = resp_ctrl_m_pg(ap, pcontrol, target);
+		}
 		offset += len;
 		break;
 	case 0x19:	/* if spc==1 then sas phy, control+discover */
@@ -2784,6 +2837,8 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 			len += resp_caching_pg(ap + len, pcontrol, target);
 		}
 		len += resp_ctrl_m_pg(ap + len, pcontrol, target);
+		if (0xff == subpcode)
+			len += resp_grouping_m_pg(ap + len, pcontrol, target);
 		len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
 		if (0xff == subpcode) {
 			len += resp_sas_pcd_m_spg(ap + len, pcontrol, target,

[PATCH v8 18/19] scsi: scsi_debug: Implement GET STREAM STATUS

[Bart Van Assche]

Implement the GET STREAM STATUS SCSI command. Report that the first
five stream indexes correspond to permanent streams.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 50 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 4e18265a05da..b2146f24f396 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -533,6 +533,8 @@ static int resp_write_scat(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_start_stop(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_readcap16(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_get_lba_status(struct scsi_cmnd *, struct sdebug_dev_info *);
+static int resp_get_stream_status(struct scsi_cmnd *scp,
+				  struct sdebug_dev_info *devip);
 static int resp_report_tgtpgs(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_unmap(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_rsup_opcodes(struct scsi_cmnd *, struct sdebug_dev_info *);
@@ -607,6 +609,9 @@ static const struct opcode_info_t sa_in_16_iarr[] = {
 	{0, 0x9e, 0x12, F_SA_LOW | F_D_IN, resp_get_lba_status, NULL,
 	    {16,  0x12, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 	     0xff, 0xff, 0xff, 0, 0xc7} },	/* GET LBA STATUS(16) */
+	{0, 0x9e, 0x16, F_SA_LOW | F_D_IN, resp_get_stream_status, NULL,
+	    {16, 0x16, 0, 0, 0xff, 0xff, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff,
+	     0, 0} },	/* GET STREAM STATUS */
 };
 
 static const struct opcode_info_t vl_iarr[] = {	/* VARIABLE LENGTH */
@@ -4581,6 +4586,51 @@ static int resp_get_lba_status(struct scsi_cmnd *scp,
 	return fill_from_dev_buffer(scp, arr, SDEBUG_GET_LBA_STATUS_LEN);
 }
 
+static int resp_get_stream_status(struct scsi_cmnd *scp,
+				  struct sdebug_dev_info *devip)
+{
+	u16 starting_stream_id, stream_id;
+	const u8 *cmd = scp->cmnd;
+	u32 alloc_len, offset;
+	u8 arr[256] = {};
+	struct scsi_stream_status_header *h = (void *)arr;
+
+	starting_stream_id = get_unaligned_be16(cmd + 4);
+	alloc_len = get_unaligned_be32(cmd + 10);
+
+	if (alloc_len < 8) {
+		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 10, -1);
+		return check_condition_result;
+	}
+
+	if (starting_stream_id >= MAXIMUM_NUMBER_OF_STREAMS) {
+		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 4, -1);
+		return check_condition_result;
+	}
+
+	/*
+	 * The GET STREAM STATUS command only reports status information
+	 * about open streams. Treat the non-permanent stream as open.
+	 */
+	put_unaligned_be16(MAXIMUM_NUMBER_OF_STREAMS,
+			   &h->number_of_open_streams);
+
+	for (offset = 8, stream_id = starting_stream_id;
+	     offset + 8 <= min_t(u32, alloc_len, sizeof(arr)) &&
+		     stream_id < MAXIMUM_NUMBER_OF_STREAMS;
+	     offset += 8, stream_id++) {
+		struct scsi_stream_status *stream_status = (void *)arr + offset;
+
+		stream_status->perm = stream_id < PERMANENT_STREAM_COUNT;
+		put_unaligned_be16(stream_id,
+				   &stream_status->stream_identifier);
+		stream_status->rel_lifetime = stream_id + 1;
+	}
+	put_unaligned_be32(offset - 8, &h->len); /* PARAMETER DATA LENGTH */
+
+	return fill_from_dev_buffer(scp, arr, min(offset, alloc_len));
+}
+
 static int resp_sync_cache(struct scsi_cmnd *scp,
 			   struct sdebug_dev_info *devip)
 {

[PATCH v8 19/19] scsi: scsi_debug: Maintain write statistics per group number

[Bart Van Assche]

Track per GROUP NUMBER how many write commands have been processed. Make
this information available in sysfs. Reset these statistics if any data
is written into the sysfs attribute.

Note: SCSI devices should only interpret the information in the GROUP
NUMBER field as a stream identifier if the ST_ENBLE bit has been set to
one. This patch follows a simpler approach: count the number of writes
per GROUP NUMBER whether or not the group number represents a stream
identifier.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 49 +++++++++++++++++++++++++++++++++++----
 1 file changed, 45 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index b2146f24f396..8eeed19adcce 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -899,6 +899,8 @@ static int sdeb_zbc_nr_conv = DEF_ZBC_NR_CONV_ZONES;
 static int submit_queues = DEF_SUBMIT_QUEUES;  /* > 1 for multi-queue (mq) */
 static int poll_queues; /* iouring iopoll interface.*/
 
+static atomic_long_t writes_by_group_number[64];
+
 static char sdebug_proc_name[] = MY_NAME;
 static const char *my_name = MY_NAME;
 
@@ -3385,7 +3387,8 @@ static inline struct sdeb_store_info *devip2sip(struct sdebug_dev_info *devip,
 
 /* Returns number of bytes copied or -1 if error. */
 static int do_device_access(struct sdeb_store_info *sip, struct scsi_cmnd *scp,
-			    u32 sg_skip, u64 lba, u32 num, bool do_write)
+			    u32 sg_skip, u64 lba, u32 num, bool do_write,
+			    u8 group_number)
 {
 	int ret;
 	u64 block, rest = 0;
@@ -3404,6 +3407,10 @@ static int do_device_access(struct sdeb_store_info *sip, struct scsi_cmnd *scp,
 		return 0;
 	if (scp->sc_data_direction != dir)
 		return -1;
+
+	if (do_write && group_number < ARRAY_SIZE(writes_by_group_number))
+		atomic_long_inc(&writes_by_group_number[group_number]);
+
 	fsp = sip->storep;
 
 	block = do_div(lba, sdebug_store_sectors);
@@ -3777,7 +3784,7 @@ static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 		}
 	}
 
-	ret = do_device_access(sip, scp, 0, lba, num, false);
+	ret = do_device_access(sip, scp, 0, lba, num, false, 0);
 	sdeb_read_unlock(sip);
 	if (unlikely(ret == -1))
 		return DID_ERROR << 16;
@@ -3962,6 +3969,7 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 {
 	bool check_prot;
 	u32 num;
+	u8 group = 0;
 	u32 ei_lba;
 	int ret;
 	u64 lba;
@@ -3973,11 +3981,13 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 		ei_lba = 0;
 		lba = get_unaligned_be64(cmd + 2);
 		num = get_unaligned_be32(cmd + 10);
+		group = cmd[14] & 0x3f;
 		check_prot = true;
 		break;
 	case WRITE_10:
 		ei_lba = 0;
 		lba = get_unaligned_be32(cmd + 2);
+		group = cmd[6] & 0x3f;
 		num = get_unaligned_be16(cmd + 7);
 		check_prot = true;
 		break;
@@ -3992,15 +4002,18 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 		ei_lba = 0;
 		lba = get_unaligned_be32(cmd + 2);
 		num = get_unaligned_be32(cmd + 6);
+		group = cmd[6] & 0x3f;
 		check_prot = true;
 		break;
 	case 0x53:	/* XDWRITEREAD(10) */
 		ei_lba = 0;
 		lba = get_unaligned_be32(cmd + 2);
+		group = cmd[6] & 0x1f;
 		num = get_unaligned_be16(cmd + 7);
 		check_prot = false;
 		break;
 	default:	/* assume WRITE(32) */
+		group = cmd[6] & 0x3f;
 		lba = get_unaligned_be64(cmd + 12);
 		ei_lba = get_unaligned_be32(cmd + 20);
 		num = get_unaligned_be32(cmd + 28);
@@ -4055,7 +4068,7 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 		}
 	}
 
-	ret = do_device_access(sip, scp, 0, lba, num, true);
+	ret = do_device_access(sip, scp, 0, lba, num, true, group);
 	if (unlikely(scsi_debug_lbp()))
 		map_region(sip, lba, num);
 	/* If ZBC zone then bump its write pointer */
@@ -4107,12 +4120,14 @@ static int resp_write_scat(struct scsi_cmnd *scp,
 	u32 lb_size = sdebug_sector_size;
 	u32 ei_lba;
 	u64 lba;
+	u8 group;
 	int ret, res;
 	bool is_16;
 	static const u32 lrd_size = 32; /* + parameter list header size */
 
 	if (cmd[0] == VARIABLE_LENGTH_CMD) {
 		is_16 = false;
+		group = cmd[6] & 0x3f;
 		wrprotect = (cmd[10] >> 5) & 0x7;
 		lbdof = get_unaligned_be16(cmd + 12);
 		num_lrd = get_unaligned_be16(cmd + 16);
@@ -4123,6 +4138,7 @@ static int resp_write_scat(struct scsi_cmnd *scp,
 		lbdof = get_unaligned_be16(cmd + 4);
 		num_lrd = get_unaligned_be16(cmd + 8);
 		bt_len = get_unaligned_be32(cmd + 10);
+		group = cmd[14] & 0x3f;
 		if (unlikely(have_dif_prot)) {
 			if (sdebug_dif == T10_PI_TYPE2_PROTECTION &&
 			    wrprotect) {
@@ -4211,7 +4227,7 @@ static int resp_write_scat(struct scsi_cmnd *scp,
 			}
 		}
 
-		ret = do_device_access(sip, scp, sg_off, lba, num, true);
+		ret = do_device_access(sip, scp, sg_off, lba, num, true, group);
 		/* If ZBC zone then bump its write pointer */
 		if (sdebug_dev_is_zoned(devip))
 			zbc_inc_wp(devip, lba, num);
@@ -7306,6 +7322,30 @@ static ssize_t tur_ms_to_ready_show(struct device_driver *ddp, char *buf)
 }
 static DRIVER_ATTR_RO(tur_ms_to_ready);
 
+static ssize_t group_number_stats_show(struct device_driver *ddp, char *buf)
+{
+	char *p = buf, *end = buf + PAGE_SIZE;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(writes_by_group_number); i++)
+		p += scnprintf(p, end - p, "%d %ld\n", i,
+			       atomic_long_read(&writes_by_group_number[i]));
+
+	return p - buf;
+}
+
+static ssize_t group_number_stats_store(struct device_driver *ddp,
+					const char *buf, size_t count)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(writes_by_group_number); i++)
+		atomic_long_set(&writes_by_group_number[i], 0);
+
+	return count;
+}
+static DRIVER_ATTR_RW(group_number_stats);
+
 /* Note: The following array creates attribute files in the
    /sys/bus/pseudo/drivers/scsi_debug directory. The advantage of these
    files (over those found in the /sys/module/scsi_debug/parameters
@@ -7352,6 +7392,7 @@ static struct attribute *sdebug_drv_attrs[] = {
 	&driver_attr_cdb_len.attr,
 	&driver_attr_tur_ms_to_ready.attr,
 	&driver_attr_zbc.attr,
+	&driver_attr_group_number_stats.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(sdebug_drv);

Re: [PATCH v8 00/19] Pass data lifetime information to SCSI disk devices

[Jens Axboe]

On 12/18/23 5:07 PM, Bart Van Assche wrote:
> Hi Martin,
> 
> UFS vendors need the data lifetime information to achieve good performance.
> Providing data lifetime information to UFS devices can result in up to 40%
> lower write amplification. Hence this patch series that adds support in F2FS
> and also in the block layer for data lifetime information. The SCSI disk (sd)
> driver is modified such that it passes write hint information to SCSI devices
> via the GROUP NUMBER field.
> 
> Please consider this patch series for the next merge window.

Bart, can you please stop reposting so quickly, it achieves the opposite
of what I suspect you are looking for.

-- 
Jens Axboe

Re: [PATCH v8 00/19] Pass data lifetime information to SCSI disk devices

[Bart Van Assche]

On 12/18/23 17:12, Jens Axboe wrote:
> Bart, can you please stop reposting so quickly, it achieves the opposite
> of what I suspect you are looking for.

Got it. I will repost less frequently.

Jens, can you please help with reviewing patches 5 and 6 of this series?
I think that's what most important right now to help this patch series
to make progress.

Thank you,

Bart.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Christoph Hellwig]

On Mon, Dec 18, 2023 at 04:07:39PM -0800, Bart Van Assche wrote:
> Write hints applied with F_SET_RW_HINT on a block device affect the
> shmem inode only. Propagate these hints to the block device inode
> because that is the inode used when writing back dirty pages.

What shmem inode?

> @@ -317,6 +318,9 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
>  
>  	inode_lock(inode);
>  	inode->i_write_hint = hint;
> +	apply_whint = inode->i_fop->apply_whint;
> +	if (apply_whint)
> +		apply_whint(file, hint);

Setting the hint in file->f_mapping->inode is the right thing here,
not adding a method.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Bart Van Assche]

On 12/27/23 23:12, Christoph Hellwig wrote:
> On Mon, Dec 18, 2023 at 04:07:39PM -0800, Bart Van Assche wrote:
>> Write hints applied with F_SET_RW_HINT on a block device affect the
>> shmem inode only. Propagate these hints to the block device inode
>> because that is the inode used when writing back dirty pages.
> 
> What shmem inode?

The inode associated with the /dev file, e.g. /dev/sda. That is another
inode than the inode associated with the struct block_device instance.
Without this patch, when opening /dev/sda and calling fcntl(), the shmem
inode is modified but the struct block_device inode not. I think that
the code path for allocation of the shmem inode is as follows:

shmem_mknod()
   shmem_get_inode()
     __shmem_get_inode()
         new_inode(sb)
           alloc_inode(sb)
             ops->alloc_inode(sb) = shmem_alloc_inode(sb)
             inode_init_always(sb, inode)
               inode->i_mapping = &inode->i_data;

>> @@ -317,6 +318,9 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
>>   
>>   	inode_lock(inode);
>>   	inode->i_write_hint = hint;
>> +	apply_whint = inode->i_fop->apply_whint;
>> +	if (apply_whint)
>> +		apply_whint(file, hint);
> 
> Setting the hint in file->f_mapping->inode is the right thing here,
> not adding a method.

Is my understanding correct that the only way to reach the struct
block_device instance from the shmem code is by dereferencing
file->private_data? Shouldn't all dereferences of that pointer happen
in source file block/fops.c since the file->private_data pointer is
assigned in that file?

Please note that suggestions to improve this patch are definitely
welcome. As you probably know I'm not that familiar with the filesystem
code.

Thanks,

Bart.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Christoph Hellwig]

On Thu, Dec 28, 2023 at 02:41:59PM -0800, Bart Van Assche wrote:
> On 12/27/23 23:12, Christoph Hellwig wrote:
>> On Mon, Dec 18, 2023 at 04:07:39PM -0800, Bart Van Assche wrote:
>>> Write hints applied with F_SET_RW_HINT on a block device affect the
>>> shmem inode only. Propagate these hints to the block device inode
>>> because that is the inode used when writing back dirty pages.
>>
>> What shmem inode?
>
> The inode associated with the /dev file, e.g. /dev/sda. That is another
> inode than the inode associated with the struct block_device instance.
> Without this patch, when opening /dev/sda and calling fcntl(), the shmem
> inode is modified but the struct block_device inode not. I think that
> the code path for allocation of the shmem inode is as follows:

So the block device node.  That can sit on any file system (or at least
any Unix-y file system that supports device nodes).

>>> @@ -317,6 +318,9 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
>>>     	inode_lock(inode);
>>>   	inode->i_write_hint = hint;
>>> +	apply_whint = inode->i_fop->apply_whint;
>>> +	if (apply_whint)
>>> +		apply_whint(file, hint);
>>
>> Setting the hint in file->f_mapping->inode is the right thing here,
>> not adding a method.
>
> Is my understanding correct that the only way to reach the struct
> block_device instance from the shmem code is by dereferencing
> file->private_data?

No.  See blkdev_open:

	filp->f_mapping = handle->bdev->bd_inode->i_mapping;

So you can use file->f_mapping->inode as I said in my previous mail.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Bart Van Assche]

On 1/3/24 01:02, Christoph Hellwig wrote:
> So you can use file->f_mapping->inode as I said in my previous mail.

Since struct address_space does not have a member with the name "inode",
I assume that you meant "host" instead of "inode"? If so, how about
modifying patch 06 of this series as shown below? With the patch below
my tests still pass.

Thanks,

Bart.


---
  block/fops.c       | 11 -----------
  fs/fcntl.c         | 15 +++++++++++----
  include/linux/fs.h |  1 -
  3 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/block/fops.c b/block/fops.c
index 138b388b5cb1..787ce52bc2c6 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -620,16 +620,6 @@ static int blkdev_release(struct inode *inode, 
struct file *filp)
  	return 0;
  }

-static void blkdev_apply_whint(struct file *file, enum rw_hint hint)
-{
-	struct bdev_handle *handle = file->private_data;
-	struct inode *bd_inode = handle->bdev->bd_inode;
-
-	inode_lock(bd_inode);
-	bd_inode->i_write_hint = hint;
-	inode_unlock(bd_inode);
-}
-
  static ssize_t
  blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from)
  {
@@ -864,7 +854,6 @@ const struct file_operations def_blk_fops = {
  	.splice_read	= filemap_splice_read,
  	.splice_write	= iter_file_splice_write,
  	.fallocate	= blkdev_fallocate,
-	.apply_whint	= blkdev_apply_whint,
  };

  static __init int blkdev_init(void)
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 18407bf5bb9b..cfb52c3a4577 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -306,7 +306,6 @@ static long fcntl_get_rw_hint(struct file *file, 
unsigned int cmd,
  static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
  			      unsigned long arg)
  {
-	void (*apply_whint)(struct file *, enum rw_hint);
  	struct inode *inode = file_inode(file);
  	u64 __user *argp = (u64 __user *)arg;
  	u64 hint;
@@ -318,11 +317,19 @@ static long fcntl_set_rw_hint(struct file *file, 
unsigned int cmd,

  	inode_lock(inode);
  	inode->i_write_hint = hint;
-	apply_whint = inode->i_fop->apply_whint;
-	if (apply_whint)
-		apply_whint(file, hint);
  	inode_unlock(inode);

+	/*
+	 * file->f_mapping->host may differ from inode. As an example,
+	 * blkdev_open() modifies file->f_mapping.
+	 */
+	if (file->f_mapping->host != inode) {
+		inode = file->f_mapping->host;
+		inode_lock(inode);
+		inode->i_write_hint = hint;
+		inode_unlock(inode);
+	}
+
  	return 0;
  }

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 293017ea2466..a08014b68d6e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1944,7 +1944,6 @@ struct file_operations {
  	int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags);
  	int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *,
  				unsigned int poll_flags);
-	void (*apply_whint)(struct file *, enum rw_hint hint);
  } __randomize_layout;

  /* Wrap a directory iterator that needs exclusive inode access */

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Christoph Hellwig]

On Wed, Jan 03, 2024 at 03:09:00PM -0800, Bart Van Assche wrote:
> Since struct address_space does not have a member with the name "inode",
> I assume that you meant "host" instead of "inode"?

Yes, sorry.

> If so, how about
> modifying patch 06 of this series as shown below? With the patch below
> my tests still pass.

This looks good, thanks.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Kanchan Joshi]

On 1/4/2024 4:39 AM, Bart Van Assche wrote:
> On 1/3/24 01:02, Christoph Hellwig wrote:
>> So you can use file->f_mapping->inode as I said in my previous mail.
> 
> Since struct address_space does not have a member with the name "inode",
> I assume that you meant "host" instead of "inode"? If so, how about
> modifying patch 06 of this series as shown below? With the patch below
> my tests still pass.
> 
> Thanks,
> 
> Bart.
> 
> 
> ---
>   block/fops.c       | 11 -----------
>   fs/fcntl.c         | 15 +++++++++++----
>   include/linux/fs.h |  1 -
>   3 files changed, 11 insertions(+), 16 deletions(-)
> 
> diff --git a/block/fops.c b/block/fops.c
> index 138b388b5cb1..787ce52bc2c6 100644
> --- a/block/fops.c
> +++ b/block/fops.c
> @@ -620,16 +620,6 @@ static int blkdev_release(struct inode *inode, 
> struct file *filp)
>       return 0;
>   }
> 
> -static void blkdev_apply_whint(struct file *file, enum rw_hint hint)
> -{
> -    struct bdev_handle *handle = file->private_data;
> -    struct inode *bd_inode = handle->bdev->bd_inode;
> -
> -    inode_lock(bd_inode);
> -    bd_inode->i_write_hint = hint;
> -    inode_unlock(bd_inode);
> -}
> -
>   static ssize_t
>   blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from)
>   {
> @@ -864,7 +854,6 @@ const struct file_operations def_blk_fops = {
>       .splice_read    = filemap_splice_read,
>       .splice_write    = iter_file_splice_write,
>       .fallocate    = blkdev_fallocate,
> -    .apply_whint    = blkdev_apply_whint,
>   };
> 
>   static __init int blkdev_init(void)
> diff --git a/fs/fcntl.c b/fs/fcntl.c
> index 18407bf5bb9b..cfb52c3a4577 100644
> --- a/fs/fcntl.c
> +++ b/fs/fcntl.c
> @@ -306,7 +306,6 @@ static long fcntl_get_rw_hint(struct file *file, 
> unsigned int cmd,
>   static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
>                     unsigned long arg)
>   {
> -    void (*apply_whint)(struct file *, enum rw_hint);
>       struct inode *inode = file_inode(file);
>       u64 __user *argp = (u64 __user *)arg;
>       u64 hint;
> @@ -318,11 +317,19 @@ static long fcntl_set_rw_hint(struct file *file, 
> unsigned int cmd,
> 
>       inode_lock(inode);
>       inode->i_write_hint = hint;
> -    apply_whint = inode->i_fop->apply_whint;
> -    if (apply_whint)
> -        apply_whint(file, hint);
>       inode_unlock(inode);
> 
> +    /*
> +     * file->f_mapping->host may differ from inode. As an example,
> +     * blkdev_open() modifies file->f_mapping.
> +     */
> +    if (file->f_mapping->host != inode) {
> +        inode = file->f_mapping->host;
> +        inode_lock(inode);
> +        inode->i_write_hint = hint;
> +        inode_unlock(inode);
> +    }
> +

Are you considering to change this so that hint is set only on one inode 
(and not on two)?
IOW, should not this fragment be like below:

--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -306,7 +306,6 @@ static long fcntl_get_rw_hint(struct file *file, 
unsigned int cmd,
  static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
                               unsigned long arg)
  {
-       void (*apply_whint)(struct file *, enum rw_hint);
         struct inode *inode = file_inode(file);
         u64 __user *argp = (u64 __user *)arg;
         u64 hint;
@@ -316,11 +315,15 @@ static long fcntl_set_rw_hint(struct file *file, 
unsigned int cmd,
         if (!rw_hint_valid(hint))
                 return -EINVAL;

+       /*
+        * file->f_mapping->host may differ from inode. As an example
+        * blkdev_open() modifies file->f_mapping
+        */
+       if (file->f_mapping->host != inode)
+               inode = file->f_mapping->host;
+
         inode_lock(inode);
         inode->i_write_hint = hint;
-       apply_whint = inode->i_fop->apply_whint;
-       if (apply_whint)
-               apply_whint(file, hint);
         inode_unlock(inode);

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Bart Van Assche]

On 1/18/24 10:51, Kanchan Joshi wrote:
> Are you considering to change this so that hint is set only on one inode
> (and not on two)?
> IOW, should not this fragment be like below:
> 
> --- a/fs/fcntl.c
> +++ b/fs/fcntl.c
> @@ -306,7 +306,6 @@ static long fcntl_get_rw_hint(struct file *file,
> unsigned int cmd,
>    static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
>                                 unsigned long arg)
>    {
> -       void (*apply_whint)(struct file *, enum rw_hint);
>           struct inode *inode = file_inode(file);
>           u64 __user *argp = (u64 __user *)arg;
>           u64 hint;
> @@ -316,11 +315,15 @@ static long fcntl_set_rw_hint(struct file *file,
> unsigned int cmd,
>           if (!rw_hint_valid(hint))
>                   return -EINVAL;
> 
> +       /*
> +        * file->f_mapping->host may differ from inode. As an example
> +        * blkdev_open() modifies file->f_mapping
> +        */
> +       if (file->f_mapping->host != inode)
> +               inode = file->f_mapping->host;
> +
>           inode_lock(inode);
>           inode->i_write_hint = hint;
> -       apply_whint = inode->i_fop->apply_whint;
> -       if (apply_whint)
> -               apply_whint(file, hint);
>           inode_unlock(inode);

I think the above proposal would introduce a bug: it would break the
F_GET_RW_HINT implementation.

Thanks,

Bart.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Kanchan Joshi]

On 1/19/2024 12:24 AM, Bart Van Assche wrote:
> On 1/18/24 10:51, Kanchan Joshi wrote:
>> Are you considering to change this so that hint is set only on one inode
>> (and not on two)?
>> IOW, should not this fragment be like below:
>>
>> --- a/fs/fcntl.c
>> +++ b/fs/fcntl.c
>> @@ -306,7 +306,6 @@ static long fcntl_get_rw_hint(struct file *file,
>> unsigned int cmd,
>>    static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
>>                                 unsigned long arg)
>>    {
>> -       void (*apply_whint)(struct file *, enum rw_hint);
>>           struct inode *inode = file_inode(file);
>>           u64 __user *argp = (u64 __user *)arg;
>>           u64 hint;
>> @@ -316,11 +315,15 @@ static long fcntl_set_rw_hint(struct file *file,
>> unsigned int cmd,
>>           if (!rw_hint_valid(hint))
>>                   return -EINVAL;
>>
>> +       /*
>> +        * file->f_mapping->host may differ from inode. As an example
>> +        * blkdev_open() modifies file->f_mapping
>> +        */
>> +       if (file->f_mapping->host != inode)
>> +               inode = file->f_mapping->host;
>> +
>>           inode_lock(inode);
>>           inode->i_write_hint = hint;
>> -       apply_whint = inode->i_fop->apply_whint;
>> -       if (apply_whint)
>> -               apply_whint(file, hint);
>>           inode_unlock(inode);
> 
> I think the above proposal would introduce a bug: it would break the
> F_GET_RW_HINT implementation.

Right. I expected to keep the exact change in GET, too, but that will 
not be free from the side-effect.
The buffered-write path (block_write_full_page) picks the hint from one 
inode, and the direct-write path (__blkdev_direct_IO_simple) picks the 
hint from a different inode.
So, updating both seems needed here.

Re: [PATCH v8 05/19] block, fs: Restore the per-bio/request data lifetime fields

[Kanchan Joshi]

On 12/19/2023 5:37 AM, Bart Van Assche wrote:

> diff --git a/block/fops.c b/block/fops.c
> index 0abaac705daf..787ce52bc2c6 100644
> --- a/block/fops.c
> +++ b/block/fops.c
> @@ -73,6 +73,7 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
>   		bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb));
>   	}
>   	bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
> +	bio.bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
>   	bio.bi_ioprio = iocb->ki_ioprio;
>   
>   	ret = bio_iov_iter_get_pages(&bio, iter);
> @@ -203,6 +204,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
>   
>   	for (;;) {
>   		bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
> +		bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
>   		bio->bi_private = dio;
>   		bio->bi_end_io = blkdev_bio_end_io;
>   		bio->bi_ioprio = iocb->ki_ioprio;
> @@ -321,6 +323,7 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
>   	dio->flags = 0;
>   	dio->iocb = iocb;
>   	bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
> +	bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;

This (and two more places above) should rather be changed to:

bio.bi_write_hint = bdev_file_inode(iocb->ki_filp)->i_write_hint;

Note that at other places too (e.g., blkdev_fallocate, blkdev_mmap, 
blkdev_lseek) bdev inode is used and not file inode.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Kanchan Joshi]

On 1/19/2024 7:26 PM, Kanchan Joshi wrote:
> On 1/19/2024 12:24 AM, Bart Van Assche wrote:
>> On 1/18/24 10:51, Kanchan Joshi wrote:
>>> Are you considering to change this so that hint is set only on one inode
>>> (and not on two)?
>>> IOW, should not this fragment be like below:
>>>
>>> --- a/fs/fcntl.c
>>> +++ b/fs/fcntl.c
>>> @@ -306,7 +306,6 @@ static long fcntl_get_rw_hint(struct file *file,
>>> unsigned int cmd,
>>>     static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
>>>                                  unsigned long arg)
>>>     {
>>> -       void (*apply_whint)(struct file *, enum rw_hint);
>>>            struct inode *inode = file_inode(file);
>>>            u64 __user *argp = (u64 __user *)arg;
>>>            u64 hint;
>>> @@ -316,11 +315,15 @@ static long fcntl_set_rw_hint(struct file *file,
>>> unsigned int cmd,
>>>            if (!rw_hint_valid(hint))
>>>                    return -EINVAL;
>>>
>>> +       /*
>>> +        * file->f_mapping->host may differ from inode. As an example
>>> +        * blkdev_open() modifies file->f_mapping
>>> +        */
>>> +       if (file->f_mapping->host != inode)
>>> +               inode = file->f_mapping->host;
>>> +
>>>            inode_lock(inode);
>>>            inode->i_write_hint = hint;
>>> -       apply_whint = inode->i_fop->apply_whint;
>>> -       if (apply_whint)
>>> -               apply_whint(file, hint);
>>>            inode_unlock(inode);
>>
>> I think the above proposal would introduce a bug: it would break the
>> F_GET_RW_HINT implementation.
> 
> Right. I expected to keep the exact change in GET, too, but that will
> not be free from the side-effect.
> The buffered-write path (block_write_full_page) picks the hint from one
> inode, and the direct-write path (__blkdev_direct_IO_simple) picks the
> hint from a different inode.
> So, updating both seems needed here.

I stand corrected. It's possible to do away with two updates.
The direct-io code (patch 8) should rather be changed to pick the hint 
from bdev inode (and not from file inode).
With that change, this patch only need to set the hint into only one 
inode (bdev one). What do you think?

Re: [PATCH v8 05/19] block, fs: Restore the per-bio/request data lifetime fields

[Bart Van Assche]

On 1/22/24 01:23, Kanchan Joshi wrote:
> On 12/19/2023 5:37 AM, Bart Van Assche wrote:
> 
>> diff --git a/block/fops.c b/block/fops.c
>> index 0abaac705daf..787ce52bc2c6 100644
>> --- a/block/fops.c
>> +++ b/block/fops.c
>> @@ -73,6 +73,7 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
>>    		bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb));
>>    	}
>>    	bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
>> +	bio.bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
>>    	bio.bi_ioprio = iocb->ki_ioprio;
>>    
>>    	ret = bio_iov_iter_get_pages(&bio, iter);
>> @@ -203,6 +204,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
>>    
>>    	for (;;) {
>>    		bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
>> +		bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
>>    		bio->bi_private = dio;
>>    		bio->bi_end_io = blkdev_bio_end_io;
>>    		bio->bi_ioprio = iocb->ki_ioprio;
>> @@ -321,6 +323,7 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
>>    	dio->flags = 0;
>>    	dio->iocb = iocb;
>>    	bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
>> +	bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
> 
> This (and two more places above) should rather be changed to:
> 
> bio.bi_write_hint = bdev_file_inode(iocb->ki_filp)->i_write_hint;
> 
> Note that at other places too (e.g., blkdev_fallocate, blkdev_mmap,
> blkdev_lseek) bdev inode is used and not file inode.

Why should this code be changed? The above code has been tested and
works fine.

Thanks,

Bart.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Bart Van Assche]

On 1/22/24 01:31, Kanchan Joshi wrote:
> On 1/19/2024 7:26 PM, Kanchan Joshi wrote:
>> On 1/19/2024 12:24 AM, Bart Van Assche wrote:
>>> I think the above proposal would introduce a bug: it would break the
>>> F_GET_RW_HINT implementation.
>>
>> Right. I expected to keep the exact change in GET, too, but that will
>> not be free from the side-effect.
>> The buffered-write path (block_write_full_page) picks the hint from one
>> inode, and the direct-write path (__blkdev_direct_IO_simple) picks the
>> hint from a different inode.
>> So, updating both seems needed here.
> 
> I stand corrected. It's possible to do away with two updates.
> The direct-io code (patch 8) should rather be changed to pick the hint
> from bdev inode (and not from file inode).
> With that change, this patch only need to set the hint into only one
> inode (bdev one). What do you think?

I think that would break direct I/O submitted by a filesystem.

Bart.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Kanchan Joshi]

On 1/23/2024 1:39 AM, Bart Van Assche wrote:
> On 1/22/24 01:31, Kanchan Joshi wrote:
>> On 1/19/2024 7:26 PM, Kanchan Joshi wrote:
>>> On 1/19/2024 12:24 AM, Bart Van Assche wrote:
>>>> I think the above proposal would introduce a bug: it would break the
>>>> F_GET_RW_HINT implementation.
>>>
>>> Right. I expected to keep the exact change in GET, too, but that will
>>> not be free from the side-effect.
>>> The buffered-write path (block_write_full_page) picks the hint from one
>>> inode, and the direct-write path (__blkdev_direct_IO_simple) picks the
>>> hint from a different inode.
>>> So, updating both seems needed here.
>>
>> I stand corrected. It's possible to do away with two updates.
>> The direct-io code (patch 8) should rather be changed to pick the hint
>> from bdev inode (and not from file inode).
>> With that change, this patch only need to set the hint into only one
>> inode (bdev one). What do you think?
> 
> I think that would break direct I/O submitted by a filesystem.
> 

By breakage do you mean not being able to set/get the hint correctly?
I tested with XFS and Ext4 direct I/O. No breakage.

Re: [PATCH v8 05/19] block, fs: Restore the per-bio/request data lifetime fields

[Kanchan Joshi]

On 1/23/2024 1:35 AM, Bart Van Assche wrote:
> On 1/22/24 01:23, Kanchan Joshi wrote:
>> On 12/19/2023 5:37 AM, Bart Van Assche wrote:
>>
>>> diff --git a/block/fops.c b/block/fops.c
>>> index 0abaac705daf..787ce52bc2c6 100644
>>> --- a/block/fops.c
>>> +++ b/block/fops.c
>>> @@ -73,6 +73,7 @@ static ssize_t __blkdev_direct_IO_simple(struct 
>>> kiocb *iocb,
>>>            bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb));
>>>        }
>>>        bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
>>> +    bio.bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
>>>        bio.bi_ioprio = iocb->ki_ioprio;
>>>        ret = bio_iov_iter_get_pages(&bio, iter);
>>> @@ -203,6 +204,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb 
>>> *iocb, struct iov_iter *iter,
>>>        for (;;) {
>>>            bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
>>> +        bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
>>>            bio->bi_private = dio;
>>>            bio->bi_end_io = blkdev_bio_end_io;
>>>            bio->bi_ioprio = iocb->ki_ioprio;
>>> @@ -321,6 +323,7 @@ static ssize_t __blkdev_direct_IO_async(struct 
>>> kiocb *iocb,
>>>        dio->flags = 0;
>>>        dio->iocb = iocb;
>>>        bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
>>> +    bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
>>
>> This (and two more places above) should rather be changed to:
>>
>> bio.bi_write_hint = bdev_file_inode(iocb->ki_filp)->i_write_hint;
>>
>> Note that at other places too (e.g., blkdev_fallocate, blkdev_mmap,
>> blkdev_lseek) bdev inode is used and not file inode.
> 
> Why should this code be changed?

Because this file is for raw block IO, and bdev_file_inode is the right 
inode to be used.

> The above code has been tested and
> works fine.

At the cost of inviting some extra work. Because this patch used 
file_inode, the patch 6 needs to set the hint on two inodes.
If we use bdev_file_inode, this whole thing becomes clean.

Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

[Bart Van Assche]

On 1/23/24 04:16, Kanchan Joshi wrote:
> On 1/23/2024 1:39 AM, Bart Van Assche wrote:
>> On 1/22/24 01:31, Kanchan Joshi wrote:
>>> On 1/19/2024 7:26 PM, Kanchan Joshi wrote:
>>>> On 1/19/2024 12:24 AM, Bart Van Assche wrote:
>>>>> I think the above proposal would introduce a bug: it would break the
>>>>> F_GET_RW_HINT implementation.
>>>>
>>>> Right. I expected to keep the exact change in GET, too, but that will
>>>> not be free from the side-effect.
>>>> The buffered-write path (block_write_full_page) picks the hint from one
>>>> inode, and the direct-write path (__blkdev_direct_IO_simple) picks the
>>>> hint from a different inode.
>>>> So, updating both seems needed here.
>>>
>>> I stand corrected. It's possible to do away with two updates.
>>> The direct-io code (patch 8) should rather be changed to pick the hint
>>> from bdev inode (and not from file inode).
>>> With that change, this patch only need to set the hint into only one
>>> inode (bdev one). What do you think?
>>
>> I think that would break direct I/O submitted by a filesystem.
> 
> By breakage do you mean not being able to set/get the hint correctly?
> I tested with XFS and Ext4 direct I/O. No breakage.

The approach that you proposed is wrong from a conceptual point of view.
Zero, one or more block devices can be associated with a filesystem. It
would be wrong to try to access all associated block devices from inside
the F_SET_RW_HINT implementation. I don't think that there is any API in
the Linux kernel for iterating over all the block devices associated with
a filesystem.

Bart.

Re: [PATCH v8 05/19] block, fs: Restore the per-bio/request data lifetime fields

[Bart Van Assche]

On 1/23/24 04:35, Kanchan Joshi wrote:
> At the cost of inviting some extra work. Because this patch used
> file_inode, the patch 6 needs to set the hint on two inodes.
> If we use bdev_file_inode, this whole thing becomes clean.

The idea of accessing block devices only in the F_SET_RW_HINT
implementation is wrong because it involves a layering violation.
With the current patch series data lifetime information is
available to filesystems like Fuse. If the F_SET_RW_HINT
implementation would iterate over block devices, no data lifetime
information would be available to filesystems like Fuse.

Bart.