[for,6.1,stable] btrfs: fix double inode unlock for direct IO sync writes

Commit Message

Filipe Manana Aug. 12, 2024, 3:27 p.m. UTC

From: Filipe Manana <[e-mail]>

commit e0391e92f9ab4fb3dbdeb139c967dcfa7ac4b115 upstream.

If we do a direct IO sync write, at btrfs_sync_file(), and we need to skip
inode logging or we get an error starting a transaction or an error when
flushing delalloc, we end up unlocking the inode when we shouldn't under
the 'out_release_extents' label, and then unlock it again at
btrfs_direct_write().

Fix that by checking if we have to skip inode unlocking under that label.

Reported-by: [e-mail]
Link: https://lore.kernel.org/linux-btrfs/[e-mail]/
Fixes: 939b656bc8ab ("btrfs: fix corruption after buffer fault in during direct IO append write")
Reviewed-by: Josef Bacik <[e-mail]>
Signed-off-by: Filipe Manana <[e-mail]>
Signed-off-by: David Sterba <[e-mail]>
---
 fs/btrfs/file.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Patch

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 7c3ae295fdb5..e23d178f9778 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2037,7 +2037,10 @@  int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 
 out_release_extents:
 	btrfs_release_log_ctx_extents(&ctx);
-	btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
+	if (skip_ilock)
+		up_write(&BTRFS_I(inode)->i_mmap_lock);
+	else
+		btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
 	goto out;
 }