diff options
| author | Darrick J. Wong <djwong@kernel.org> | 2023-07-17 09:00:09 -0700 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2023-07-17 09:00:09 -0700 |
| commit | 880b9577855edddda1e732748e849c63199d489b (patch) | |
| tree | 8864baba5793708725a2c440be96c218846eeaef /block | |
| parent | fdf0eaf11452d72945af31804e2a1048ee1b574c (diff) | |
| download | linux-880b9577855edddda1e732748e849c63199d489b.tar.gz | |
fs: distinguish between user initiated freeze and kernel initiated freeze
Userspace can freeze a filesystem using the FIFREEZE ioctl or by
suspending the block device; this state persists until userspace thaws
the filesystem with the FITHAW ioctl or resuming the block device.
Since commit 18e9e5104fcd ("Introduce freeze_super and thaw_super for
the fsfreeze ioctl") we only allow the first freeze command to succeed.
The kernel may decide that it is necessary to freeze a filesystem for
its own internal purposes, such as suspends in progress, filesystem fsck
activities, or quiescing a device prior to removal. Userspace thaw
commands must never break a kernel freeze, and kernel thaw commands
shouldn't undo userspace's freeze command.
Introduce a couple of freeze holder flags and wire it into the
sb_writers state. One kernel and one userspace freeze are allowed to
coexist at the same time; the filesystem will not thaw until both are
lifted.
I wonder if the f2fs/gfs2 code should be using a kernel freeze here, but
for now we'll use FREEZE_HOLDER_USERSPACE to preserve existing
behaviors.
Cc: mcgrof@kernel.org
Cc: jack@suse.cz
Cc: hch@infradead.org
Cc: ruansy.fnst@fujitsu.com
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bdev.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/block/bdev.c b/block/bdev.c index 979e28a46b988..80ea3fa3593b1 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -248,9 +248,9 @@ int freeze_bdev(struct block_device *bdev) if (!sb) goto sync; if (sb->s_op->freeze_super) - error = sb->s_op->freeze_super(sb); + error = sb->s_op->freeze_super(sb, FREEZE_HOLDER_USERSPACE); else - error = freeze_super(sb); + error = freeze_super(sb, FREEZE_HOLDER_USERSPACE); deactivate_super(sb); if (error) { @@ -291,9 +291,9 @@ int thaw_bdev(struct block_device *bdev) goto out; if (sb->s_op->thaw_super) - error = sb->s_op->thaw_super(sb); + error = sb->s_op->thaw_super(sb, FREEZE_HOLDER_USERSPACE); else - error = thaw_super(sb); + error = thaw_super(sb, FREEZE_HOLDER_USERSPACE); if (error) bdev->bd_fsfreeze_count++; else |