5.15-stable review patch. If anyone has any objections, please let me know.
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From: Filipe Manana fdmanana@suse.com
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: syzbot+7dbbb74af6291b5a5a8b@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/000000000000dfd631061eaeb4bc@google.com/ Fixes: 939b656bc8ab ("btrfs: fix corruption after buffer fault in during direct IO append write") Reviewed-by: Josef Bacik josef@toxicpanda.com Signed-off-by: Filipe Manana fdmanana@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/file.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2433,7 +2433,10 @@ out:
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; }