On Thu, May 20, 2021 at 09:07:26AM +0800, Qu Wenruo wrote:

quoted

-			btrfs_update_inode(trans, root, BTRFS_I(inode));

I did a quick grep and found that we have other locations where we call
btrfs_uppdate_inode() without catching the return value:

$ grep -IRe "^\s\+btrfs_update_inode(" fs/btrfs/
fs/btrfs/free-space-cache.c:    btrfs_update_inode(trans, root,
BTRFS_I(inode));
fs/btrfs/free-space-cache.c:    btrfs_update_inode(trans, root,
BTRFS_I(inode));
fs/btrfs/inode.c:               btrfs_update_inode(trans, root, inode);
fs/btrfs/inode.c:       btrfs_update_inode(trans, root, BTRFS_I(inode));

Maybe it's better to make btrfs_update_inode() to have __must_check prefix?

We should handle errors everywhere by default, with rare exceptions that
might get a comment why it's ok to ignore the errors. So that would mean
that basically all functions get __must_check attribute if we really
want to catch that.