[PATCH v3 0/29] block: Make blkdev_get_by_*() return handle

[PATCH v3 0/29] block: Make blkdev_get_by_*() return handle

[Jan Kara]

Hello,

this is a v3 of the patch series which implements the idea of blkdev_get_by_*()
calls returning bdev_handle which is then passed to blkdev_put() [1]. This
makes the get and put calls for bdevs more obviously matching and allows us to
propagate context from get to put without having to modify all the users
(again!). In particular I need to propagate used open flags to blkdev_put() to
be able count writeable opens and add support for blocking writes to mounted
block devices. I'll send that series separately.

The series is based on Christian's vfs tree as of today as there is quite
some overlap. Patches have passed some reasonable testing - I've tested block
changes, md, dm, bcache, xfs, btrfs, ext4, swap. More testing or review is
always welcome. Thanks! I've pushed out the full branch to:

git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git bdev_handle

to ease review / testing. Since there were not many comments for v2 and
Christoph has acked the series I think we should start discussing how to merge
the series. Most collisions with this series seem to happen in the filesystems
area so VFS tree would seem as the least painful way to merge this. Jens,
are you OK with that?

Changes since v2:
* Rebased on top of current vfs tree
* Added some acks
* Reflected minor nits from Christoph
* Added missing conversion of blkdev_put() calls in cramfs and erofs
* Fixed possible leak of bdev handle in xfs if logdev is the same as fs dev

Changes since v1:
* Rebased on top of current vfs tree
* Renamed final functions to bdev_open_by_*() and bdev_release()
* Fixed detection of exclusive open in blkdev_ioctl() and blkdev_fallocate()
* Fixed swap conversion to properly reinitialize swap_info->bdev_handle
* Fixed xfs conversion to not oops with rtdev without logdev
* Couple other minor fixups

								Honza

[1] https://lore.kernel.org/all/ZJGNsVDhZx0Xgs2H@infradead.org

CC: Alasdair Kergon <agk@redhat.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Anna Schumaker <anna@kernel.org>
CC: Chao Yu <chao@kernel.org>
CC: Christian Borntraeger <borntraeger@linux.ibm.com>
CC: Coly Li <colyli@suse.de
CC: "Darrick J. Wong" <djwong@kernel.org>
CC: Dave Kleikamp <shaggy@kernel.org>
CC: David Sterba <dsterba@suse.com>
CC: dm-devel@redhat.com
CC: drbd-dev@lists.linbit.com
CC: Gao Xiang <xiang@kernel.org>
CC: Jack Wang <jinpu.wang@ionos.com>
CC: Jaegeuk Kim <jaegeuk@kernel.org>
CC: jfs-discussion@lists.sourceforge.net
CC: Joern Engel <joern@lazybastard.org>
CC: Joseph Qi <joseph.qi@linux.alibaba.com>
CC: Kent Overstreet <kent.overstreet@gmail.com>
CC: linux-bcache@vger.kernel.org
CC: linux-btrfs@vger.kernel.org
CC: linux-erofs@lists.ozlabs.org
CC: <linux-ext4@vger.kernel.org>
CC: linux-f2fs-devel@lists.sourceforge.net
CC: linux-mm@kvack.org
CC: linux-mtd@lists.infradead.org
CC: linux-nfs@vger.kernel.org
CC: linux-nilfs@vger.kernel.org
CC: linux-nvme@lists.infradead.org
CC: linux-pm@vger.kernel.org
CC: linux-raid@vger.kernel.org
CC: linux-s390@vger.kernel.org
CC: linux-scsi@vger.kernel.org
CC: linux-xfs@vger.kernel.org
CC: "Md. Haris Iqbal" <haris.iqbal@ionos.com>
CC: Mike Snitzer <snitzer@kernel.org>
CC: Minchan Kim <minchan@kernel.org>
CC: ocfs2-devel@oss.oracle.com
CC: reiserfs-devel@vger.kernel.org
CC: Sergey Senozhatsky <senozhatsky@chromium.org>
CC: Song Liu <song@kernel.org>
CC: Sven Schnelle <svens@linux.ibm.com>
CC: target-devel@vger.kernel.org
CC: Ted Tso <tytso@mit.edu>
CC: Trond Myklebust <trond.myklebust@hammerspace.com>
CC: xen-devel@lists.xenproject.org

Previous versions:
Link: http://lore.kernel.org/r/20230629165206.383-1-jack@suse.cz # v1
Link: http://lore.kernel.org/r/20230810171429.31759-1-jack@suse.cz # v2

[PATCH 28/29] xfs: Convert to bdev_open_by_path()

[Jan Kara]

Convert xfs to use bdev_open_by_path() and pass the handle around.

CC: "Darrick J. Wong" <djwong@kernel.org>
CC: linux-xfs@vger.kernel.org
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/xfs/xfs_buf.c   | 22 +++++++++----------
 fs/xfs/xfs_buf.h   |  3 ++-
 fs/xfs/xfs_super.c | 54 +++++++++++++++++++++++++---------------------
 3 files changed, 42 insertions(+), 37 deletions(-)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 3b903f6bce98..496e2f5fdcc6 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1938,8 +1938,6 @@ void
 xfs_free_buftarg(
 	struct xfs_buftarg	*btp)
 {
-	struct block_device	*bdev = btp->bt_bdev;
-
 	unregister_shrinker(&btp->bt_shrinker);
 	ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0);
 	percpu_counter_destroy(&btp->bt_io_count);
@@ -1947,8 +1945,8 @@ xfs_free_buftarg(
 
 	fs_put_dax(btp->bt_daxdev, btp->bt_mount);
 	/* the main block device is closed by kill_block_super */
-	if (bdev != btp->bt_mount->m_super->s_bdev)
-		blkdev_put(bdev, btp->bt_mount->m_super);
+	if (btp->bt_bdev != btp->bt_mount->m_super->s_bdev)
+		bdev_release(btp->bt_bdev_handle);
 
 	kmem_free(btp);
 }
@@ -1983,16 +1981,15 @@ xfs_setsize_buftarg(
  */
 STATIC int
 xfs_setsize_buftarg_early(
-	xfs_buftarg_t		*btp,
-	struct block_device	*bdev)
+	xfs_buftarg_t		*btp)
 {
-	return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev));
+	return xfs_setsize_buftarg(btp, bdev_logical_block_size(btp->bt_bdev));
 }
 
 struct xfs_buftarg *
 xfs_alloc_buftarg(
 	struct xfs_mount	*mp,
-	struct block_device	*bdev)
+	struct bdev_handle	*bdev_handle)
 {
 	xfs_buftarg_t		*btp;
 	const struct dax_holder_operations *ops = NULL;
@@ -2003,9 +2000,10 @@ xfs_alloc_buftarg(
 	btp = kmem_zalloc(sizeof(*btp), KM_NOFS);
 
 	btp->bt_mount = mp;
-	btp->bt_dev =  bdev->bd_dev;
-	btp->bt_bdev = bdev;
-	btp->bt_daxdev = fs_dax_get_by_bdev(bdev, &btp->bt_dax_part_off,
+	btp->bt_bdev_handle = bdev_handle;
+	btp->bt_dev =  bdev_handle->bdev->bd_dev;
+	btp->bt_bdev = bdev_handle->bdev;
+	btp->bt_daxdev = fs_dax_get_by_bdev(btp->bt_bdev, &btp->bt_dax_part_off,
 					    mp, ops);
 
 	/*
@@ -2015,7 +2013,7 @@ xfs_alloc_buftarg(
 	ratelimit_state_init(&btp->bt_ioerror_rl, 30 * HZ,
 			     DEFAULT_RATELIMIT_BURST);
 
-	if (xfs_setsize_buftarg_early(btp, bdev))
+	if (xfs_setsize_buftarg_early(btp))
 		goto error_free;
 
 	if (list_lru_init(&btp->bt_lru))
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 549c60942208..f6418c1312f5 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -92,6 +92,7 @@ typedef unsigned int xfs_buf_flags_t;
  */
 typedef struct xfs_buftarg {
 	dev_t			bt_dev;
+	struct bdev_handle	*bt_bdev_handle;
 	struct block_device	*bt_bdev;
 	struct dax_device	*bt_daxdev;
 	u64			bt_dax_part_off;
@@ -351,7 +352,7 @@ xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
  *	Handling of buftargs.
  */
 struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp,
-		struct block_device *bdev);
+		struct bdev_handle *bdev_handle);
 extern void xfs_free_buftarg(struct xfs_buftarg *);
 extern void xfs_buftarg_wait(struct xfs_buftarg *);
 extern void xfs_buftarg_drain(struct xfs_buftarg *);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index c79eac048456..6a3a295f84b7 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -381,14 +381,15 @@ STATIC int
 xfs_blkdev_get(
 	xfs_mount_t		*mp,
 	const char		*name,
-	struct block_device	**bdevp)
+	struct bdev_handle	**handlep)
 {
 	int			error = 0;
 
-	*bdevp = blkdev_get_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
-				    mp->m_super, &fs_holder_ops);
-	if (IS_ERR(*bdevp)) {
-		error = PTR_ERR(*bdevp);
+	*handlep = bdev_open_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
+				     mp->m_super, &fs_holder_ops);
+	if (IS_ERR(*handlep)) {
+		error = PTR_ERR(*handlep);
+		*handlep = NULL;
 		xfs_warn(mp, "Invalid device [%s], error=%d", name, error);
 	}
 
@@ -426,15 +427,15 @@ xfs_shutdown_devices(
 	 * race, everyone loses.
 	 */
 	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
-		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
-		invalidate_bdev(mp->m_logdev_targp->bt_bdev);
+		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev_handle->bdev);
+		invalidate_bdev(mp->m_logdev_targp->bt_bdev_handle->bdev);
 	}
 	if (mp->m_rtdev_targp) {
-		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
-		invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
+		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev_handle->bdev);
+		invalidate_bdev(mp->m_rtdev_targp->bt_bdev_handle->bdev);
 	}
-	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
-	invalidate_bdev(mp->m_ddev_targp->bt_bdev);
+	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev_handle->bdev);
+	invalidate_bdev(mp->m_ddev_targp->bt_bdev_handle->bdev);
 }
 
 /*
@@ -453,7 +454,7 @@ xfs_open_devices(
 {
 	struct super_block	*sb = mp->m_super;
 	struct block_device	*ddev = sb->s_bdev;
-	struct block_device	*logdev = NULL, *rtdev = NULL;
+	struct bdev_handle	*logdev_handle = NULL, *rtdev_handle = NULL;
 	int			error;
 
 	/*
@@ -466,17 +467,19 @@ xfs_open_devices(
 	 * Open real time and log devices - order is important.
 	 */
 	if (mp->m_logname) {
-		error = xfs_blkdev_get(mp, mp->m_logname, &logdev);
+		error = xfs_blkdev_get(mp, mp->m_logname, &logdev_handle);
 		if (error)
 			goto out_relock;
 	}
 
 	if (mp->m_rtname) {
-		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev);
+		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev_handle);
 		if (error)
 			goto out_close_logdev;
 
-		if (rtdev == ddev || rtdev == logdev) {
+		if (rtdev_handle->bdev == ddev ||
+		    (logdev_handle &&
+		     rtdev_handle->bdev == logdev_handle->bdev)) {
 			xfs_warn(mp,
 	"Cannot mount filesystem with identical rtdev and ddev/logdev.");
 			error = -EINVAL;
@@ -488,22 +491,25 @@ xfs_open_devices(
 	 * Setup xfs_mount buffer target pointers
 	 */
 	error = -ENOMEM;
-	mp->m_ddev_targp = xfs_alloc_buftarg(mp, ddev);
+	mp->m_ddev_targp = xfs_alloc_buftarg(mp, sb->s_bdev_handle);
 	if (!mp->m_ddev_targp)
 		goto out_close_rtdev;
 
-	if (rtdev) {
-		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev);
+	if (rtdev_handle) {
+		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev_handle);
 		if (!mp->m_rtdev_targp)
 			goto out_free_ddev_targ;
 	}
 
-	if (logdev && logdev != ddev) {
-		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev);
+	if (logdev_handle && logdev_handle->bdev != ddev) {
+		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev_handle);
 		if (!mp->m_logdev_targp)
 			goto out_free_rtdev_targ;
 	} else {
 		mp->m_logdev_targp = mp->m_ddev_targp;
+		/* Handle won't be used, drop it */
+		if (logdev_handle)
+			bdev_release(logdev_handle);
 	}
 
 	error = 0;
@@ -517,11 +523,11 @@ xfs_open_devices(
  out_free_ddev_targ:
 	xfs_free_buftarg(mp->m_ddev_targp);
  out_close_rtdev:
-	 if (rtdev)
-		 blkdev_put(rtdev, sb);
+	 if (rtdev_handle)
+		bdev_release(rtdev_handle);
  out_close_logdev:
-	if (logdev && logdev != ddev)
-		blkdev_put(logdev, sb);
+	if (logdev_handle)
+		bdev_release(logdev_handle);
 	goto out_relock;
 }
 
-- 
2.35.3

Re: [PATCH 28/29] xfs: Convert to bdev_open_by_path()

[Dave Chinner]

On Wed, Aug 23, 2023 at 12:48:39PM +0200, Jan Kara wrote:
> Convert xfs to use bdev_open_by_path() and pass the handle around.
....

> @@ -426,15 +427,15 @@ xfs_shutdown_devices(
>  	 * race, everyone loses.
>  	 */
>  	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
> -		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
> -		invalidate_bdev(mp->m_logdev_targp->bt_bdev);
> +		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev_handle->bdev);
> +		invalidate_bdev(mp->m_logdev_targp->bt_bdev_handle->bdev);
>  	}
>  	if (mp->m_rtdev_targp) {
> -		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
> -		invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
> +		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> +		invalidate_bdev(mp->m_rtdev_targp->bt_bdev_handle->bdev);
>  	}
> -	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
> -	invalidate_bdev(mp->m_ddev_targp->bt_bdev);
> +	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev_handle->bdev);
> +	invalidate_bdev(mp->m_ddev_targp->bt_bdev_handle->bdev);
>  }

Why do these need to be converted to run through bt_bdev_handle?  If
the buftarg is present and we've assigned targp->bt_bdev_handle
during the call to xfs_alloc_buftarg(), then we've assigned
targp->bt_bdev from the handle at the same time, yes?

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

Re: [PATCH 28/29] xfs: Convert to bdev_open_by_path()

[Jan Kara]

On Thu 24-08-23 08:11:42, Dave Chinner wrote:
> On Wed, Aug 23, 2023 at 12:48:39PM +0200, Jan Kara wrote:
> > Convert xfs to use bdev_open_by_path() and pass the handle around.
> ....
> 
> > @@ -426,15 +427,15 @@ xfs_shutdown_devices(
> >  	 * race, everyone loses.
> >  	 */
> >  	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
> > -		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
> > -		invalidate_bdev(mp->m_logdev_targp->bt_bdev);
> > +		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev_handle->bdev);
> > +		invalidate_bdev(mp->m_logdev_targp->bt_bdev_handle->bdev);
> >  	}
> >  	if (mp->m_rtdev_targp) {
> > -		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
> > -		invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
> > +		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> > +		invalidate_bdev(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> >  	}
> > -	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
> > -	invalidate_bdev(mp->m_ddev_targp->bt_bdev);
> > +	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev_handle->bdev);
> > +	invalidate_bdev(mp->m_ddev_targp->bt_bdev_handle->bdev);
> >  }
> 
> Why do these need to be converted to run through bt_bdev_handle?  If
> the buftarg is present and we've assigned targp->bt_bdev_handle
> during the call to xfs_alloc_buftarg(), then we've assigned
> targp->bt_bdev from the handle at the same time, yes?

Good point, these conversions are pointless now so I've removed them. They
are leftover from a previous version based on a kernel where xfs was
dropping bdev references in a different place. Thanks for noticing.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 28/29] xfs: Convert to bdev_open_by_path()

[Jan Kara]

[-- Attachment #1: Type: text/plain, Size: 1833 bytes --]

On Thu 24-08-23 12:28:37, Jan Kara wrote:
> On Thu 24-08-23 08:11:42, Dave Chinner wrote:
> > On Wed, Aug 23, 2023 at 12:48:39PM +0200, Jan Kara wrote:
> > > Convert xfs to use bdev_open_by_path() and pass the handle around.
> > ....
> > 
> > > @@ -426,15 +427,15 @@ xfs_shutdown_devices(
> > >  	 * race, everyone loses.
> > >  	 */
> > >  	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
> > > -		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
> > > -		invalidate_bdev(mp->m_logdev_targp->bt_bdev);
> > > +		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev_handle->bdev);
> > > +		invalidate_bdev(mp->m_logdev_targp->bt_bdev_handle->bdev);
> > >  	}
> > >  	if (mp->m_rtdev_targp) {
> > > -		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
> > > -		invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
> > > +		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> > > +		invalidate_bdev(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> > >  	}
> > > -	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
> > > -	invalidate_bdev(mp->m_ddev_targp->bt_bdev);
> > > +	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev_handle->bdev);
> > > +	invalidate_bdev(mp->m_ddev_targp->bt_bdev_handle->bdev);
> > >  }
> > 
> > Why do these need to be converted to run through bt_bdev_handle?  If
> > the buftarg is present and we've assigned targp->bt_bdev_handle
> > during the call to xfs_alloc_buftarg(), then we've assigned
> > targp->bt_bdev from the handle at the same time, yes?
> 
> Good point, these conversions are pointless now so I've removed them. They
> are leftover from a previous version based on a kernel where xfs was
> dropping bdev references in a different place. Thanks for noticing.

FWIW attached is a new version of the patch I have currently in my tree.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

[-- Attachment #2: 0001-xfs-Convert-to-bdev_open_by_path.patch --]
[-- Type: text/x-patch, Size: 6405 bytes --]

From 7ba12a848a8dcf70029c897b8cf7bca6d4f8c098 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Fri, 23 Jun 2023 15:48:53 +0200
Subject: [PATCH] xfs: Convert to bdev_open_by_path()

Convert xfs to use bdev_open_by_path() and pass the handle around.

CC: "Darrick J. Wong" <djwong@kernel.org>
CC: linux-xfs@vger.kernel.org
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/xfs/xfs_buf.c   | 22 ++++++++++------------
 fs/xfs/xfs_buf.h   |  3 ++-
 fs/xfs/xfs_super.c | 42 ++++++++++++++++++++++++------------------
 3 files changed, 36 insertions(+), 31 deletions(-)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 3b903f6bce98..75a98eec2b27 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1938,8 +1938,6 @@ void
 xfs_free_buftarg(
 	struct xfs_buftarg	*btp)
 {
-	struct block_device	*bdev = btp->bt_bdev;
-
 	unregister_shrinker(&btp->bt_shrinker);
 	ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0);
 	percpu_counter_destroy(&btp->bt_io_count);
@@ -1947,8 +1945,8 @@ xfs_free_buftarg(
 
 	fs_put_dax(btp->bt_daxdev, btp->bt_mount);
 	/* the main block device is closed by kill_block_super */
-	if (bdev != btp->bt_mount->m_super->s_bdev)
-		blkdev_put(bdev, btp->bt_mount->m_super);
+	if (btp->bt_bdev != btp->bt_mount->m_super->s_bdev)
+		bdev_release(btp->bt_bdev_handle);
 
 	kmem_free(btp);
 }
@@ -1983,16 +1981,15 @@ xfs_setsize_buftarg(
  */
 STATIC int
 xfs_setsize_buftarg_early(
-	xfs_buftarg_t		*btp,
-	struct block_device	*bdev)
+	xfs_buftarg_t		*btp)
 {
-	return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev));
+	return xfs_setsize_buftarg(btp, bdev_logical_block_size(btp->bt_bdev));
 }
 
 struct xfs_buftarg *
 xfs_alloc_buftarg(
 	struct xfs_mount	*mp,
-	struct block_device	*bdev)
+	struct bdev_handle	*bdev_handle)
 {
 	xfs_buftarg_t		*btp;
 	const struct dax_holder_operations *ops = NULL;
@@ -2003,9 +2000,10 @@ xfs_alloc_buftarg(
 	btp = kmem_zalloc(sizeof(*btp), KM_NOFS);
 
 	btp->bt_mount = mp;
-	btp->bt_dev =  bdev->bd_dev;
-	btp->bt_bdev = bdev;
-	btp->bt_daxdev = fs_dax_get_by_bdev(bdev, &btp->bt_dax_part_off,
+	btp->bt_bdev_handle = bdev_handle;
+	btp->bt_dev = bdev_handle->bdev->bd_dev;
+	btp->bt_bdev = bdev_handle->bdev;
+	btp->bt_daxdev = fs_dax_get_by_bdev(btp->bt_bdev, &btp->bt_dax_part_off,
 					    mp, ops);
 
 	/*
@@ -2015,7 +2013,7 @@ xfs_alloc_buftarg(
 	ratelimit_state_init(&btp->bt_ioerror_rl, 30 * HZ,
 			     DEFAULT_RATELIMIT_BURST);
 
-	if (xfs_setsize_buftarg_early(btp, bdev))
+	if (xfs_setsize_buftarg_early(btp))
 		goto error_free;
 
 	if (list_lru_init(&btp->bt_lru))
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 549c60942208..f6418c1312f5 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -92,6 +92,7 @@ typedef unsigned int xfs_buf_flags_t;
  */
 typedef struct xfs_buftarg {
 	dev_t			bt_dev;
+	struct bdev_handle	*bt_bdev_handle;
 	struct block_device	*bt_bdev;
 	struct dax_device	*bt_daxdev;
 	u64			bt_dax_part_off;
@@ -351,7 +352,7 @@ xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
  *	Handling of buftargs.
  */
 struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp,
-		struct block_device *bdev);
+		struct bdev_handle *bdev_handle);
 extern void xfs_free_buftarg(struct xfs_buftarg *);
 extern void xfs_buftarg_wait(struct xfs_buftarg *);
 extern void xfs_buftarg_drain(struct xfs_buftarg *);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index c79eac048456..c98f08553ba8 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -381,14 +381,15 @@ STATIC int
 xfs_blkdev_get(
 	xfs_mount_t		*mp,
 	const char		*name,
-	struct block_device	**bdevp)
+	struct bdev_handle	**handlep)
 {
 	int			error = 0;
 
-	*bdevp = blkdev_get_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
-				    mp->m_super, &fs_holder_ops);
-	if (IS_ERR(*bdevp)) {
-		error = PTR_ERR(*bdevp);
+	*handlep = bdev_open_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
+				     mp->m_super, &fs_holder_ops);
+	if (IS_ERR(*handlep)) {
+		error = PTR_ERR(*handlep);
+		*handlep = NULL;
 		xfs_warn(mp, "Invalid device [%s], error=%d", name, error);
 	}
 
@@ -453,7 +454,7 @@ xfs_open_devices(
 {
 	struct super_block	*sb = mp->m_super;
 	struct block_device	*ddev = sb->s_bdev;
-	struct block_device	*logdev = NULL, *rtdev = NULL;
+	struct bdev_handle	*logdev_handle = NULL, *rtdev_handle = NULL;
 	int			error;
 
 	/*
@@ -466,17 +467,19 @@ xfs_open_devices(
 	 * Open real time and log devices - order is important.
 	 */
 	if (mp->m_logname) {
-		error = xfs_blkdev_get(mp, mp->m_logname, &logdev);
+		error = xfs_blkdev_get(mp, mp->m_logname, &logdev_handle);
 		if (error)
 			goto out_relock;
 	}
 
 	if (mp->m_rtname) {
-		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev);
+		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev_handle);
 		if (error)
 			goto out_close_logdev;
 
-		if (rtdev == ddev || rtdev == logdev) {
+		if (rtdev_handle->bdev == ddev ||
+		    (logdev_handle &&
+		     rtdev_handle->bdev == logdev_handle->bdev)) {
 			xfs_warn(mp,
 	"Cannot mount filesystem with identical rtdev and ddev/logdev.");
 			error = -EINVAL;
@@ -488,22 +491,25 @@ xfs_open_devices(
 	 * Setup xfs_mount buffer target pointers
 	 */
 	error = -ENOMEM;
-	mp->m_ddev_targp = xfs_alloc_buftarg(mp, ddev);
+	mp->m_ddev_targp = xfs_alloc_buftarg(mp, sb->s_bdev_handle);
 	if (!mp->m_ddev_targp)
 		goto out_close_rtdev;
 
-	if (rtdev) {
-		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev);
+	if (rtdev_handle) {
+		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev_handle);
 		if (!mp->m_rtdev_targp)
 			goto out_free_ddev_targ;
 	}
 
-	if (logdev && logdev != ddev) {
-		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev);
+	if (logdev_handle && logdev_handle->bdev != ddev) {
+		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev_handle);
 		if (!mp->m_logdev_targp)
 			goto out_free_rtdev_targ;
 	} else {
 		mp->m_logdev_targp = mp->m_ddev_targp;
+		/* Handle won't be used, drop it */
+		if (logdev_handle)
+			bdev_release(logdev_handle);
 	}
 
 	error = 0;
@@ -517,11 +523,11 @@ xfs_open_devices(
  out_free_ddev_targ:
 	xfs_free_buftarg(mp->m_ddev_targp);
  out_close_rtdev:
-	 if (rtdev)
-		 blkdev_put(rtdev, sb);
+	 if (rtdev_handle)
+		bdev_release(rtdev_handle);
  out_close_logdev:
-	if (logdev && logdev != ddev)
-		blkdev_put(logdev, sb);
+	if (logdev_handle)
+		bdev_release(logdev_handle);
 	goto out_relock;
 }
 
-- 
2.35.3

Re: [PATCH 28/29] xfs: Convert to bdev_open_by_path()

[Dave Chinner]

On Thu, Aug 24, 2023 at 10:29:10PM +0200, Jan Kara wrote:
> On Thu 24-08-23 12:28:37, Jan Kara wrote:
> > On Thu 24-08-23 08:11:42, Dave Chinner wrote:
> > > On Wed, Aug 23, 2023 at 12:48:39PM +0200, Jan Kara wrote:
> > > > Convert xfs to use bdev_open_by_path() and pass the handle around.
> > > ....
> > > 
> > > > @@ -426,15 +427,15 @@ xfs_shutdown_devices(
> > > >  	 * race, everyone loses.
> > > >  	 */
> > > >  	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
> > > > -		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
> > > > -		invalidate_bdev(mp->m_logdev_targp->bt_bdev);
> > > > +		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev_handle->bdev);
> > > > +		invalidate_bdev(mp->m_logdev_targp->bt_bdev_handle->bdev);
> > > >  	}
> > > >  	if (mp->m_rtdev_targp) {
> > > > -		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
> > > > -		invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
> > > > +		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> > > > +		invalidate_bdev(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> > > >  	}
> > > > -	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
> > > > -	invalidate_bdev(mp->m_ddev_targp->bt_bdev);
> > > > +	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev_handle->bdev);
> > > > +	invalidate_bdev(mp->m_ddev_targp->bt_bdev_handle->bdev);
> > > >  }
> > > 
> > > Why do these need to be converted to run through bt_bdev_handle?  If
> > > the buftarg is present and we've assigned targp->bt_bdev_handle
> > > during the call to xfs_alloc_buftarg(), then we've assigned
> > > targp->bt_bdev from the handle at the same time, yes?
> > 
> > Good point, these conversions are pointless now so I've removed them. They
> > are leftover from a previous version based on a kernel where xfs was
> > dropping bdev references in a different place. Thanks for noticing.
> 
> FWIW attached is a new version of the patch I have currently in my tree.

Looks OK.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

-- 
Dave Chinner
david@fromorbit.com

Re: [PATCH 28/29] xfs: Convert to bdev_open_by_path()

[Christian Brauner]

On Thu, Aug 24, 2023 at 10:29:10PM +0200, Jan Kara wrote:
> On Thu 24-08-23 12:28:37, Jan Kara wrote:
> > On Thu 24-08-23 08:11:42, Dave Chinner wrote:
> > > On Wed, Aug 23, 2023 at 12:48:39PM +0200, Jan Kara wrote:
> > > > Convert xfs to use bdev_open_by_path() and pass the handle around.
> > > ....
> > > 
> > > > @@ -426,15 +427,15 @@ xfs_shutdown_devices(
> > > >  	 * race, everyone loses.
> > > >  	 */
> > > >  	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
> > > > -		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
> > > > -		invalidate_bdev(mp->m_logdev_targp->bt_bdev);
> > > > +		blkdev_issue_flush(mp->m_logdev_targp->bt_bdev_handle->bdev);
> > > > +		invalidate_bdev(mp->m_logdev_targp->bt_bdev_handle->bdev);
> > > >  	}
> > > >  	if (mp->m_rtdev_targp) {
> > > > -		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
> > > > -		invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
> > > > +		blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> > > > +		invalidate_bdev(mp->m_rtdev_targp->bt_bdev_handle->bdev);
> > > >  	}
> > > > -	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
> > > > -	invalidate_bdev(mp->m_ddev_targp->bt_bdev);
> > > > +	blkdev_issue_flush(mp->m_ddev_targp->bt_bdev_handle->bdev);
> > > > +	invalidate_bdev(mp->m_ddev_targp->bt_bdev_handle->bdev);
> > > >  }
> > > 
> > > Why do these need to be converted to run through bt_bdev_handle?  If
> > > the buftarg is present and we've assigned targp->bt_bdev_handle
> > > during the call to xfs_alloc_buftarg(), then we've assigned
> > > targp->bt_bdev from the handle at the same time, yes?
> > 
> > Good point, these conversions are pointless now so I've removed them. They
> > are leftover from a previous version based on a kernel where xfs was
> > dropping bdev references in a different place. Thanks for noticing.
> 
> FWIW attached is a new version of the patch I have currently in my tree.

The appended patch looks good to me,
Reviewed-by: Christian Brauner <brauner@kernel.org>

Re: [PATCH v3 0/29] block: Make blkdev_get_by_*() return handle

[Christian Brauner]

On Wed, Aug 23, 2023 at 12:48:11PM +0200, Jan Kara wrote:
> Hello,
> 
> this is a v3 of the patch series which implements the idea of blkdev_get_by_*()
> calls returning bdev_handle which is then passed to blkdev_put() [1]. This
> makes the get and put calls for bdevs more obviously matching and allows us to
> propagate context from get to put without having to modify all the users
> (again!). In particular I need to propagate used open flags to blkdev_put() to
> be able count writeable opens and add support for blocking writes to mounted
> block devices. I'll send that series separately.
> 
> The series is based on Christian's vfs tree as of today as there is quite
> some overlap. Patches have passed some reasonable testing - I've tested block
> changes, md, dm, bcache, xfs, btrfs, ext4, swap. More testing or review is
> always welcome. Thanks! I've pushed out the full branch to:
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git bdev_handle
> 
> to ease review / testing. Since there were not many comments for v2 and
> Christoph has acked the series I think we should start discussing how to merge
> the series. Most collisions with this series seem to happen in the filesystems
> area so VFS tree would seem as the least painful way to merge this. Jens,

I really do like this series especially struct bdev_handle and moving
the mode bits in there. I'll happily take this. So far there have only
been minor things that can easily be fixed.

Re: [PATCH v3 0/29] block: Make blkdev_get_by_*() return handle

[Jan Kara]

On Fri 25-08-23 15:32:47, Christian Brauner wrote:
> On Wed, Aug 23, 2023 at 12:48:11PM +0200, Jan Kara wrote:
> > Hello,
> > 
> > this is a v3 of the patch series which implements the idea of blkdev_get_by_*()
> > calls returning bdev_handle which is then passed to blkdev_put() [1]. This
> > makes the get and put calls for bdevs more obviously matching and allows us to
> > propagate context from get to put without having to modify all the users
> > (again!). In particular I need to propagate used open flags to blkdev_put() to
> > be able count writeable opens and add support for blocking writes to mounted
> > block devices. I'll send that series separately.
> > 
> > The series is based on Christian's vfs tree as of today as there is quite
> > some overlap. Patches have passed some reasonable testing - I've tested block
> > changes, md, dm, bcache, xfs, btrfs, ext4, swap. More testing or review is
> > always welcome. Thanks! I've pushed out the full branch to:
> > 
> > git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git bdev_handle
> > 
> > to ease review / testing. Since there were not many comments for v2 and
> > Christoph has acked the series I think we should start discussing how to merge
> > the series. Most collisions with this series seem to happen in the filesystems
> > area so VFS tree would seem as the least painful way to merge this. Jens,
> 
> I really do like this series especially struct bdev_handle and moving
> the mode bits in there. I'll happily take this. So far there have only
> been minor things that can easily be fixed.

Thanks. Since Al is fine with just doing a potential conversion to 'struct
file' as a handle on top of this series (it will be dumb Coccinelle
replacement) I think we can go ahead with the series as is. As you said
there will be some conflicts in btrfs and I've learned about f2fs conflicts
as well so I can rebase & repost the series on top of rc1 to make life
easier for you.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH v3 0/29] block: Make blkdev_get_by_*() return handle

[Christian Brauner]

> replacement) I think we can go ahead with the series as is. As you said
> there will be some conflicts in btrfs and I've learned about f2fs conflicts
> as well so I can rebase & repost the series on top of rc1 to make life
> easier for you.

That is be much appreciated. Thank you!

[PATCH v4 0/29] block: Make blkdev_get_by_*() return handle

[Jan Kara]

Hello,

this is a v3 of the patch series which implements the idea of blkdev_get_by_*()
calls returning bdev_handle which is then passed to blkdev_put() [1]. This
makes the get and put calls for bdevs more obviously matching and allows us to
propagate context from get to put without having to modify all the users
(again!). In particular I need to propagate used open flags to blkdev_put() to
be able count writeable opens and add support for blocking writes to mounted
block devices. I'll send that series separately.

The series is based on Btrfs tree's for-next branch [2] as of today as the
series depends on Christoph's changes to btrfs device handling.  Patches have
passed some reasonable testing - I've tested block changes, md, dm, bcache,
xfs, btrfs, ext4, swap. More testing or review is always welcome. Thanks! I've
pushed out the full branch to:

git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git bdev_handle

to ease review / testing. Christian, can you pull the patches to your tree
to get some exposure in linux-next as well? Thanks!

Changes since v3:
* Rebased on top on btrfs tree

Changes since v2:
* Rebased on top of current vfs tree
* Added some acks
* Reflected minor nits from Christoph
* Added missing conversion of blkdev_put() calls in cramfs and erofs
* Fixed possible leak of bdev handle in xfs if logdev is the same as fs dev

Changes since v1:
* Rebased on top of current vfs tree
* Renamed final functions to bdev_open_by_*() and bdev_release()
* Fixed detection of exclusive open in blkdev_ioctl() and blkdev_fallocate()
* Fixed swap conversion to properly reinitialize swap_info->bdev_handle
* Fixed xfs conversion to not oops with rtdev without logdev
* Couple other minor fixups

								Honza

[1] https://lore.kernel.org/all/ZJGNsVDhZx0Xgs2H@infradead.org
[2] git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next

CC: Alasdair Kergon <agk@redhat.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Anna Schumaker <anna@kernel.org>
CC: Chao Yu <chao@kernel.org>
CC: Christian Borntraeger <borntraeger@linux.ibm.com>
CC: Coly Li <colyli@suse.de
CC: "Darrick J. Wong" <djwong@kernel.org>
CC: Dave Kleikamp <shaggy@kernel.org>
CC: David Sterba <dsterba@suse.com>
CC: dm-devel@redhat.com
CC: drbd-dev@lists.linbit.com
CC: Gao Xiang <xiang@kernel.org>
CC: Jack Wang <jinpu.wang@ionos.com>
CC: Jaegeuk Kim <jaegeuk@kernel.org>
CC: jfs-discussion@lists.sourceforge.net
CC: Joern Engel <joern@lazybastard.org>
CC: Joseph Qi <joseph.qi@linux.alibaba.com>
CC: Kent Overstreet <kent.overstreet@gmail.com>
CC: linux-bcache@vger.kernel.org
CC: linux-btrfs@vger.kernel.org
CC: linux-erofs@lists.ozlabs.org
CC: <linux-ext4@vger.kernel.org>
CC: linux-f2fs-devel@lists.sourceforge.net
CC: linux-mm@kvack.org
CC: linux-mtd@lists.infradead.org
CC: linux-nfs@vger.kernel.org
CC: linux-nilfs@vger.kernel.org
CC: linux-nvme@lists.infradead.org
CC: linux-pm@vger.kernel.org
CC: linux-raid@vger.kernel.org
CC: linux-s390@vger.kernel.org
CC: linux-scsi@vger.kernel.org
CC: linux-xfs@vger.kernel.org
CC: "Md. Haris Iqbal" <haris.iqbal@ionos.com>
CC: Mike Snitzer <snitzer@kernel.org>
CC: Minchan Kim <minchan@kernel.org>
CC: ocfs2-devel@oss.oracle.com
CC: reiserfs-devel@vger.kernel.org
CC: Sergey Senozhatsky <senozhatsky@chromium.org>
CC: Song Liu <song@kernel.org>
CC: Sven Schnelle <svens@linux.ibm.com>
CC: target-devel@vger.kernel.org
CC: Ted Tso <tytso@mit.edu>
CC: Trond Myklebust <trond.myklebust@hammerspace.com>
CC: xen-devel@lists.xenproject.org

Previous versions:
Link: http://lore.kernel.org/r/20230629165206.383-1-jack@suse.cz # v1
Link: http://lore.kernel.org/r/20230810171429.31759-1-jack@suse.cz # v2

[PATCH 28/29] xfs: Convert to bdev_open_by_path()

[Jan Kara]

Convert xfs to use bdev_open_by_path() and pass the handle around.

CC: "Darrick J. Wong" <djwong@kernel.org>
CC: linux-xfs@vger.kernel.org
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/xfs/xfs_buf.c   | 22 ++++++++++------------
 fs/xfs/xfs_buf.h   |  3 ++-
 fs/xfs/xfs_super.c | 42 ++++++++++++++++++++++++------------------
 3 files changed, 36 insertions(+), 31 deletions(-)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index c1ece4a08ff4..003e157241da 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1945,8 +1945,6 @@ void
 xfs_free_buftarg(
 	struct xfs_buftarg	*btp)
 {
-	struct block_device	*bdev = btp->bt_bdev;
-
 	unregister_shrinker(&btp->bt_shrinker);
 	ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0);
 	percpu_counter_destroy(&btp->bt_io_count);
@@ -1954,8 +1952,8 @@ xfs_free_buftarg(
 
 	fs_put_dax(btp->bt_daxdev, btp->bt_mount);
 	/* the main block device is closed by kill_block_super */
-	if (bdev != btp->bt_mount->m_super->s_bdev)
-		blkdev_put(bdev, btp->bt_mount->m_super);
+	if (btp->bt_bdev != btp->bt_mount->m_super->s_bdev)
+		bdev_release(btp->bt_bdev_handle);
 
 	kmem_free(btp);
 }
@@ -1990,16 +1988,15 @@ xfs_setsize_buftarg(
  */
 STATIC int
 xfs_setsize_buftarg_early(
-	xfs_buftarg_t		*btp,
-	struct block_device	*bdev)
+	xfs_buftarg_t		*btp)
 {
-	return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev));
+	return xfs_setsize_buftarg(btp, bdev_logical_block_size(btp->bt_bdev));
 }
 
 struct xfs_buftarg *
 xfs_alloc_buftarg(
 	struct xfs_mount	*mp,
-	struct block_device	*bdev)
+	struct bdev_handle	*bdev_handle)
 {
 	xfs_buftarg_t		*btp;
 	const struct dax_holder_operations *ops = NULL;
@@ -2010,9 +2007,10 @@ xfs_alloc_buftarg(
 	btp = kmem_zalloc(sizeof(*btp), KM_NOFS);
 
 	btp->bt_mount = mp;
-	btp->bt_dev =  bdev->bd_dev;
-	btp->bt_bdev = bdev;
-	btp->bt_daxdev = fs_dax_get_by_bdev(bdev, &btp->bt_dax_part_off,
+	btp->bt_bdev_handle = bdev_handle;
+	btp->bt_dev = bdev_handle->bdev->bd_dev;
+	btp->bt_bdev = bdev_handle->bdev;
+	btp->bt_daxdev = fs_dax_get_by_bdev(btp->bt_bdev, &btp->bt_dax_part_off,
 					    mp, ops);
 
 	/*
@@ -2022,7 +2020,7 @@ xfs_alloc_buftarg(
 	ratelimit_state_init(&btp->bt_ioerror_rl, 30 * HZ,
 			     DEFAULT_RATELIMIT_BURST);
 
-	if (xfs_setsize_buftarg_early(btp, bdev))
+	if (xfs_setsize_buftarg_early(btp))
 		goto error_free;
 
 	if (list_lru_init(&btp->bt_lru))
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index df8f47953bb4..ada9d310b7d3 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -98,6 +98,7 @@ typedef unsigned int xfs_buf_flags_t;
  */
 typedef struct xfs_buftarg {
 	dev_t			bt_dev;
+	struct bdev_handle	*bt_bdev_handle;
 	struct block_device	*bt_bdev;
 	struct dax_device	*bt_daxdev;
 	u64			bt_dax_part_off;
@@ -364,7 +365,7 @@ xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
  *	Handling of buftargs.
  */
 struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp,
-		struct block_device *bdev);
+		struct bdev_handle *bdev_handle);
 extern void xfs_free_buftarg(struct xfs_buftarg *);
 extern void xfs_buftarg_wait(struct xfs_buftarg *);
 extern void xfs_buftarg_drain(struct xfs_buftarg *);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 819a3568b28f..f0ae07828153 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -361,14 +361,15 @@ STATIC int
 xfs_blkdev_get(
 	xfs_mount_t		*mp,
 	const char		*name,
-	struct block_device	**bdevp)
+	struct bdev_handle	**handlep)
 {
 	int			error = 0;
 
-	*bdevp = blkdev_get_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
-				    mp->m_super, &fs_holder_ops);
-	if (IS_ERR(*bdevp)) {
-		error = PTR_ERR(*bdevp);
+	*handlep = bdev_open_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
+				     mp->m_super, &fs_holder_ops);
+	if (IS_ERR(*handlep)) {
+		error = PTR_ERR(*handlep);
+		*handlep = NULL;
 		xfs_warn(mp, "Invalid device [%s], error=%d", name, error);
 	}
 
@@ -433,7 +434,7 @@ xfs_open_devices(
 {
 	struct super_block	*sb = mp->m_super;
 	struct block_device	*ddev = sb->s_bdev;
-	struct block_device	*logdev = NULL, *rtdev = NULL;
+	struct bdev_handle	*logdev_handle = NULL, *rtdev_handle = NULL;
 	int			error;
 
 	/*
@@ -446,17 +447,19 @@ xfs_open_devices(
 	 * Open real time and log devices - order is important.
 	 */
 	if (mp->m_logname) {
-		error = xfs_blkdev_get(mp, mp->m_logname, &logdev);
+		error = xfs_blkdev_get(mp, mp->m_logname, &logdev_handle);
 		if (error)
 			goto out_relock;
 	}
 
 	if (mp->m_rtname) {
-		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev);
+		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev_handle);
 		if (error)
 			goto out_close_logdev;
 
-		if (rtdev == ddev || rtdev == logdev) {
+		if (rtdev_handle->bdev == ddev ||
+		    (logdev_handle &&
+		     rtdev_handle->bdev == logdev_handle->bdev)) {
 			xfs_warn(mp,
 	"Cannot mount filesystem with identical rtdev and ddev/logdev.");
 			error = -EINVAL;
@@ -468,22 +471,25 @@ xfs_open_devices(
 	 * Setup xfs_mount buffer target pointers
 	 */
 	error = -ENOMEM;
-	mp->m_ddev_targp = xfs_alloc_buftarg(mp, ddev);
+	mp->m_ddev_targp = xfs_alloc_buftarg(mp, sb->s_bdev_handle);
 	if (!mp->m_ddev_targp)
 		goto out_close_rtdev;
 
-	if (rtdev) {
-		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev);
+	if (rtdev_handle) {
+		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev_handle);
 		if (!mp->m_rtdev_targp)
 			goto out_free_ddev_targ;
 	}
 
-	if (logdev && logdev != ddev) {
-		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev);
+	if (logdev_handle && logdev_handle->bdev != ddev) {
+		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev_handle);
 		if (!mp->m_logdev_targp)
 			goto out_free_rtdev_targ;
 	} else {
 		mp->m_logdev_targp = mp->m_ddev_targp;
+		/* Handle won't be used, drop it */
+		if (logdev_handle)
+			bdev_release(logdev_handle);
 	}
 
 	error = 0;
@@ -497,11 +503,11 @@ xfs_open_devices(
  out_free_ddev_targ:
 	xfs_free_buftarg(mp->m_ddev_targp);
  out_close_rtdev:
-	 if (rtdev)
-		 blkdev_put(rtdev, sb);
+	 if (rtdev_handle)
+		bdev_release(rtdev_handle);
  out_close_logdev:
-	if (logdev && logdev != ddev)
-		blkdev_put(logdev, sb);
+	if (logdev_handle)
+		bdev_release(logdev_handle);
 	goto out_relock;
 }
 
-- 
2.35.3

Re: [PATCH v4 0/29] block: Make blkdev_get_by_*() return handle

[Jens Axboe]

On Wed, Sep 27, 2023 at 3:34?AM Jan Kara <jack@suse.cz> wrote:
>
> Hello,
>
> this is a v3 of the patch series which implements the idea of blkdev_get_by_*()

v4?

> calls returning bdev_handle which is then passed to blkdev_put() [1]. This
> makes the get and put calls for bdevs more obviously matching and allows us to
> propagate context from get to put without having to modify all the users
> (again!). In particular I need to propagate used open flags to blkdev_put() to
> be able count writeable opens and add support for blocking writes to mounted
> block devices. I'll send that series separately.
>
> The series is based on Btrfs tree's for-next branch [2] as of today as the
> series depends on Christoph's changes to btrfs device handling.  Patches have
> passed some reasonable testing - I've tested block changes, md, dm, bcache,
> xfs, btrfs, ext4, swap. More testing or review is always welcome. Thanks! I've
> pushed out the full branch to:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git bdev_handle
>
> to ease review / testing. Christian, can you pull the patches to your tree
> to get some exposure in linux-next as well? Thanks!

For the block bits:

Acked-by: Jens Axboe <axboe@kernel.dk>

-- 
Jens Axboe

Re: [PATCH 28/29] xfs: Convert to bdev_open_by_path()

[Darrick J. Wong]

On Wed, Sep 27, 2023 at 11:34:34AM +0200, Jan Kara wrote:
> Convert xfs to use bdev_open_by_path() and pass the handle around.
> 
> CC: "Darrick J. Wong" <djwong@kernel.org>
> CC: linux-xfs@vger.kernel.org
> Acked-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Dave Chinner <dchinner@redhat.com>
> Reviewed-by: Christian Brauner <brauner@kernel.org>
> Signed-off-by: Jan Kara <jack@suse.cz>

Looks like a pretty straightforward conversion, so:

For the block parts,
Acked-by: Darrick J. Wong <djwong@kernel.org>

For this patch:
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_buf.c   | 22 ++++++++++------------
>  fs/xfs/xfs_buf.h   |  3 ++-
>  fs/xfs/xfs_super.c | 42 ++++++++++++++++++++++++------------------
>  3 files changed, 36 insertions(+), 31 deletions(-)
> 
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index c1ece4a08ff4..003e157241da 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -1945,8 +1945,6 @@ void
>  xfs_free_buftarg(
>  	struct xfs_buftarg	*btp)
>  {
> -	struct block_device	*bdev = btp->bt_bdev;
> -
>  	unregister_shrinker(&btp->bt_shrinker);
>  	ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0);
>  	percpu_counter_destroy(&btp->bt_io_count);
> @@ -1954,8 +1952,8 @@ xfs_free_buftarg(
>  
>  	fs_put_dax(btp->bt_daxdev, btp->bt_mount);
>  	/* the main block device is closed by kill_block_super */
> -	if (bdev != btp->bt_mount->m_super->s_bdev)
> -		blkdev_put(bdev, btp->bt_mount->m_super);
> +	if (btp->bt_bdev != btp->bt_mount->m_super->s_bdev)
> +		bdev_release(btp->bt_bdev_handle);
>  
>  	kmem_free(btp);
>  }
> @@ -1990,16 +1988,15 @@ xfs_setsize_buftarg(
>   */
>  STATIC int
>  xfs_setsize_buftarg_early(
> -	xfs_buftarg_t		*btp,
> -	struct block_device	*bdev)
> +	xfs_buftarg_t		*btp)
>  {
> -	return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev));
> +	return xfs_setsize_buftarg(btp, bdev_logical_block_size(btp->bt_bdev));
>  }
>  
>  struct xfs_buftarg *
>  xfs_alloc_buftarg(
>  	struct xfs_mount	*mp,
> -	struct block_device	*bdev)
> +	struct bdev_handle	*bdev_handle)
>  {
>  	xfs_buftarg_t		*btp;
>  	const struct dax_holder_operations *ops = NULL;
> @@ -2010,9 +2007,10 @@ xfs_alloc_buftarg(
>  	btp = kmem_zalloc(sizeof(*btp), KM_NOFS);
>  
>  	btp->bt_mount = mp;
> -	btp->bt_dev =  bdev->bd_dev;
> -	btp->bt_bdev = bdev;
> -	btp->bt_daxdev = fs_dax_get_by_bdev(bdev, &btp->bt_dax_part_off,
> +	btp->bt_bdev_handle = bdev_handle;
> +	btp->bt_dev = bdev_handle->bdev->bd_dev;
> +	btp->bt_bdev = bdev_handle->bdev;
> +	btp->bt_daxdev = fs_dax_get_by_bdev(btp->bt_bdev, &btp->bt_dax_part_off,
>  					    mp, ops);
>  
>  	/*
> @@ -2022,7 +2020,7 @@ xfs_alloc_buftarg(
>  	ratelimit_state_init(&btp->bt_ioerror_rl, 30 * HZ,
>  			     DEFAULT_RATELIMIT_BURST);
>  
> -	if (xfs_setsize_buftarg_early(btp, bdev))
> +	if (xfs_setsize_buftarg_early(btp))
>  		goto error_free;
>  
>  	if (list_lru_init(&btp->bt_lru))
> diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
> index df8f47953bb4..ada9d310b7d3 100644
> --- a/fs/xfs/xfs_buf.h
> +++ b/fs/xfs/xfs_buf.h
> @@ -98,6 +98,7 @@ typedef unsigned int xfs_buf_flags_t;
>   */
>  typedef struct xfs_buftarg {
>  	dev_t			bt_dev;
> +	struct bdev_handle	*bt_bdev_handle;
>  	struct block_device	*bt_bdev;
>  	struct dax_device	*bt_daxdev;
>  	u64			bt_dax_part_off;
> @@ -364,7 +365,7 @@ xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
>   *	Handling of buftargs.
>   */
>  struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp,
> -		struct block_device *bdev);
> +		struct bdev_handle *bdev_handle);
>  extern void xfs_free_buftarg(struct xfs_buftarg *);
>  extern void xfs_buftarg_wait(struct xfs_buftarg *);
>  extern void xfs_buftarg_drain(struct xfs_buftarg *);
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 819a3568b28f..f0ae07828153 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -361,14 +361,15 @@ STATIC int
>  xfs_blkdev_get(
>  	xfs_mount_t		*mp,
>  	const char		*name,
> -	struct block_device	**bdevp)
> +	struct bdev_handle	**handlep)
>  {
>  	int			error = 0;
>  
> -	*bdevp = blkdev_get_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
> -				    mp->m_super, &fs_holder_ops);
> -	if (IS_ERR(*bdevp)) {
> -		error = PTR_ERR(*bdevp);
> +	*handlep = bdev_open_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
> +				     mp->m_super, &fs_holder_ops);
> +	if (IS_ERR(*handlep)) {
> +		error = PTR_ERR(*handlep);
> +		*handlep = NULL;
>  		xfs_warn(mp, "Invalid device [%s], error=%d", name, error);
>  	}
>  
> @@ -433,7 +434,7 @@ xfs_open_devices(
>  {
>  	struct super_block	*sb = mp->m_super;
>  	struct block_device	*ddev = sb->s_bdev;
> -	struct block_device	*logdev = NULL, *rtdev = NULL;
> +	struct bdev_handle	*logdev_handle = NULL, *rtdev_handle = NULL;
>  	int			error;
>  
>  	/*
> @@ -446,17 +447,19 @@ xfs_open_devices(
>  	 * Open real time and log devices - order is important.
>  	 */
>  	if (mp->m_logname) {
> -		error = xfs_blkdev_get(mp, mp->m_logname, &logdev);
> +		error = xfs_blkdev_get(mp, mp->m_logname, &logdev_handle);
>  		if (error)
>  			goto out_relock;
>  	}
>  
>  	if (mp->m_rtname) {
> -		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev);
> +		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev_handle);
>  		if (error)
>  			goto out_close_logdev;
>  
> -		if (rtdev == ddev || rtdev == logdev) {
> +		if (rtdev_handle->bdev == ddev ||
> +		    (logdev_handle &&
> +		     rtdev_handle->bdev == logdev_handle->bdev)) {
>  			xfs_warn(mp,
>  	"Cannot mount filesystem with identical rtdev and ddev/logdev.");
>  			error = -EINVAL;
> @@ -468,22 +471,25 @@ xfs_open_devices(
>  	 * Setup xfs_mount buffer target pointers
>  	 */
>  	error = -ENOMEM;
> -	mp->m_ddev_targp = xfs_alloc_buftarg(mp, ddev);
> +	mp->m_ddev_targp = xfs_alloc_buftarg(mp, sb->s_bdev_handle);
>  	if (!mp->m_ddev_targp)
>  		goto out_close_rtdev;
>  
> -	if (rtdev) {
> -		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev);
> +	if (rtdev_handle) {
> +		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev_handle);
>  		if (!mp->m_rtdev_targp)
>  			goto out_free_ddev_targ;
>  	}
>  
> -	if (logdev && logdev != ddev) {
> -		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev);
> +	if (logdev_handle && logdev_handle->bdev != ddev) {
> +		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev_handle);
>  		if (!mp->m_logdev_targp)
>  			goto out_free_rtdev_targ;
>  	} else {
>  		mp->m_logdev_targp = mp->m_ddev_targp;
> +		/* Handle won't be used, drop it */
> +		if (logdev_handle)
> +			bdev_release(logdev_handle);
>  	}
>  
>  	error = 0;
> @@ -497,11 +503,11 @@ xfs_open_devices(
>   out_free_ddev_targ:
>  	xfs_free_buftarg(mp->m_ddev_targp);
>   out_close_rtdev:
> -	 if (rtdev)
> -		 blkdev_put(rtdev, sb);
> +	 if (rtdev_handle)
> +		bdev_release(rtdev_handle);
>   out_close_logdev:
> -	if (logdev && logdev != ddev)
> -		blkdev_put(logdev, sb);
> +	if (logdev_handle)
> +		bdev_release(logdev_handle);
>  	goto out_relock;
>  }
>  
> -- 
> 2.35.3
> 

Re: [PATCH v4 0/29] block: Make blkdev_get_by_*() return handle

[Christian Brauner]

On Wed, 27 Sep 2023 11:34:07 +0200, Jan Kara wrote:
> Create struct bdev_handle that contains all parameters that need to be
> passed to blkdev_put() and provide bdev_open_* functions that return
> this structure instead of plain bdev pointer. This will eventually allow
> us to pass one more argument to blkdev_put() (renamed to bdev_release())
> without too much hassle.
> 
> 
> [...]

> to ease review / testing. Christian, can you pull the patches to your tree
> to get some exposure in linux-next as well? Thanks!

Yep. So I did it slighly differently. I pulled in the btrfs prereqs and
then applied your series on top of it so we get all the Link: tags right.
I'm running tests right now. Please double-check.

---

Applied to the vfs.super branch of the vfs/vfs.git tree.
Patches in the vfs.super branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.super

[01/29] block: Provide bdev_open_* functions
       https://git.kernel.org/vfs/vfs/c/b7c828aa0b3c
[02/29] block: Use bdev_open_by_dev() in blkdev_open()
        https://git.kernel.org/vfs/vfs/c/d4e36f27b45a
[03/29] block: Use bdev_open_by_dev() in disk_scan_partitions() and blkdev_bszset()
        https://git.kernel.org/vfs/vfs/c/5f9bd6764c7a
[04/29] drdb: Convert to use bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/0220ca8e443d
[05/29] pktcdvd: Convert to bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/7af10b889789
[06/29] rnbd-srv: Convert to use bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/3d27892a4be7
[07/29] xen/blkback: Convert to bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/26afb0ed10b3
[08/29] zram: Convert to use bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/efc8e3f4c6dc
[09/29] bcache: Convert to bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/dc893f51d24a
[10/29] dm: Convert to bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/80c2267c6d07
[11/29] md: Convert to bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/15db36126ca6
[12/29] mtd: block2mtd: Convert to bdev_open_by_dev/path()
        https://git.kernel.org/vfs/vfs/c/4c27234bf3ce
[13/29] nvmet: Convert to bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/70cffddcc300
[14/29] s390/dasd: Convert to bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/5581d03457f8
[15/29] scsi: target: Convert to bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/43de7d844d47
[16/29] PM: hibernate: Convert to bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/105ea4a2fd18
[17/29] PM: hibernate: Drop unused snapshot_test argument
        https://git.kernel.org/vfs/vfs/c/b589a66e3688
[18/29] mm/swap: Convert to use bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/615af8e29233
[19/29] fs: Convert to bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/5173192bcfe6
[20/29] btrfs: Convert to bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/8cf64782764f
[21/29] erofs: Convert to use bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/4d41880bf249
[22/29] ext4: Convert to bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/f7507612395e
[23/29] f2fs: Convert to bdev_open_by_dev/path()
        https://git.kernel.org/vfs/vfs/c/d9ff8e3b6498
[24/29] jfs: Convert to bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/459dc6376338
[25/29] nfs/blocklayout: Convert to use bdev_open_by_dev/path()
        https://git.kernel.org/vfs/vfs/c/5b1df9a40929
[26/29] ocfs2: Convert to use bdev_open_by_dev()
        https://git.kernel.org/vfs/vfs/c/b6b95acbd943
[27/29] reiserfs: Convert to bdev_open_by_dev/path()
        https://git.kernel.org/vfs/vfs/c/7e3615ff6119
[28/29] xfs: Convert to bdev_open_by_path()
        https://git.kernel.org/vfs/vfs/c/176ccb99e207
[29/29] block: Remove blkdev_get_by_*() functions
        https://git.kernel.org/vfs/vfs/c/953863a5a2ff

Re: [PATCH v4 0/29] block: Make blkdev_get_by_*() return handle

[Jan Kara]

On Wed 27-09-23 18:21:19, Christian Brauner wrote:
> On Wed, 27 Sep 2023 11:34:07 +0200, Jan Kara wrote:
> > Create struct bdev_handle that contains all parameters that need to be
> > passed to blkdev_put() and provide bdev_open_* functions that return
> > this structure instead of plain bdev pointer. This will eventually allow
> > us to pass one more argument to blkdev_put() (renamed to bdev_release())
> > without too much hassle.
> > 
> > 
> > [...]
> 
> > to ease review / testing. Christian, can you pull the patches to your tree
> > to get some exposure in linux-next as well? Thanks!
> 
> Yep. So I did it slighly differently. I pulled in the btrfs prereqs and
> then applied your series on top of it so we get all the Link: tags right.
> I'm running tests right now. Please double-check.

Thanks for picking patches up! I've checked the branch and it looks good to
me. 

								Honza

> 
> ---
> 
> Applied to the vfs.super branch of the vfs/vfs.git tree.
> Patches in the vfs.super branch should appear in linux-next soon.
> 
> Please report any outstanding bugs that were missed during review in a
> new review to the original patch series allowing us to drop it.
> 
> It's encouraged to provide Acked-bys and Reviewed-bys even though the
> patch has now been applied. If possible patch trailers will be updated.
> 
> Note that commit hashes shown below are subject to change due to rebase,
> trailer updates or similar. If in doubt, please check the listed branch.
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
> branch: vfs.super
> 
> [01/29] block: Provide bdev_open_* functions
>        https://git.kernel.org/vfs/vfs/c/b7c828aa0b3c
> [02/29] block: Use bdev_open_by_dev() in blkdev_open()
>         https://git.kernel.org/vfs/vfs/c/d4e36f27b45a
> [03/29] block: Use bdev_open_by_dev() in disk_scan_partitions() and blkdev_bszset()
>         https://git.kernel.org/vfs/vfs/c/5f9bd6764c7a
> [04/29] drdb: Convert to use bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/0220ca8e443d
> [05/29] pktcdvd: Convert to bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/7af10b889789
> [06/29] rnbd-srv: Convert to use bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/3d27892a4be7
> [07/29] xen/blkback: Convert to bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/26afb0ed10b3
> [08/29] zram: Convert to use bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/efc8e3f4c6dc
> [09/29] bcache: Convert to bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/dc893f51d24a
> [10/29] dm: Convert to bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/80c2267c6d07
> [11/29] md: Convert to bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/15db36126ca6
> [12/29] mtd: block2mtd: Convert to bdev_open_by_dev/path()
>         https://git.kernel.org/vfs/vfs/c/4c27234bf3ce
> [13/29] nvmet: Convert to bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/70cffddcc300
> [14/29] s390/dasd: Convert to bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/5581d03457f8
> [15/29] scsi: target: Convert to bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/43de7d844d47
> [16/29] PM: hibernate: Convert to bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/105ea4a2fd18
> [17/29] PM: hibernate: Drop unused snapshot_test argument
>         https://git.kernel.org/vfs/vfs/c/b589a66e3688
> [18/29] mm/swap: Convert to use bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/615af8e29233
> [19/29] fs: Convert to bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/5173192bcfe6
> [20/29] btrfs: Convert to bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/8cf64782764f
> [21/29] erofs: Convert to use bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/4d41880bf249
> [22/29] ext4: Convert to bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/f7507612395e
> [23/29] f2fs: Convert to bdev_open_by_dev/path()
>         https://git.kernel.org/vfs/vfs/c/d9ff8e3b6498
> [24/29] jfs: Convert to bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/459dc6376338
> [25/29] nfs/blocklayout: Convert to use bdev_open_by_dev/path()
>         https://git.kernel.org/vfs/vfs/c/5b1df9a40929
> [26/29] ocfs2: Convert to use bdev_open_by_dev()
>         https://git.kernel.org/vfs/vfs/c/b6b95acbd943
> [27/29] reiserfs: Convert to bdev_open_by_dev/path()
>         https://git.kernel.org/vfs/vfs/c/7e3615ff6119
> [28/29] xfs: Convert to bdev_open_by_path()
>         https://git.kernel.org/vfs/vfs/c/176ccb99e207
> [29/29] block: Remove blkdev_get_by_*() functions
>         https://git.kernel.org/vfs/vfs/c/953863a5a2ff
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR