--- /dev/null
+From e0391e92f9ab4fb3dbdeb139c967dcfa7ac4b115 Mon Sep 17 00:00:00 2001
+From: Filipe Manana <fdmanana@suse.com>
+Date: Fri, 2 Aug 2024 09:38:51 +0100
+Subject: btrfs: fix double inode unlock for direct IO sync writes
+
+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
+@@ -2080,7 +2080,10 @@ out:
+
+ out_release_extents:
+ btrfs_release_log_ctx_extents(&ctx);
+- btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP);
++ if (skip_ilock)
++ up_write(&BTRFS_I(inode)->i_mmap_lock);
++ else
++ btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP);
+ goto out;
+ }
+