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Date:   Thu, 20 May 2021 15:24:10 +0200
From:   David Sterba <dsterba@suse.cz>
To:     Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc:     Josef Bacik <josef@toxicpanda.com>, linux-btrfs@vger.kernel.org,
        kernel-team@fb.com
Subject: Re: [PATCH] btrfs: check error value from btrfs_update_inode in tree
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On Thu, May 20, 2021 at 09:07:26AM +0800, Qu Wenruo wrote:
> > -			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.