Re: [PATCH 2/7] repair: don't dirty inodes which are not unlinked

From: Dave Chinner <david@fromorbit.com>
To: Eric Sandeen <sandeen@sandeen.net>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 2/7] repair: don't dirty inodes which are not unlinked
Date: Wed, 31 Oct 2018 07:58:45 +1100	[thread overview]
Message-ID: <20181030205845.GS19305@dastard> (raw)
In-Reply-To: <ef573c7c-0522-0564-c552-e5ef684b5444@sandeen.net>

On Tue, Oct 30, 2018 at 03:40:20PM -0500, Eric Sandeen wrote:
> 
> 
> On 10/30/18 3:34 PM, Dave Chinner wrote:
> > On Tue, Oct 30, 2018 at 03:09:56PM -0500, Eric Sandeen wrote:
> >> So I'm not stealing commits: ;)
> >>
> >> ===
> >>
> >> repair: don't dirty inodes unconditionally when testing unlinked state
> >>
> >> From: Dave Chinner <dchinner@redhat.com>
> >>
> >> I noticed phase 4 writing back lots of inode buffers during recent
> >> testing. The recent rework of clear_inode() in commit 0724d0f4cb53
> >> ("xfs_repair: clear_dinode should simply clear, not check contents")
> >> accidentally caught a call to clear_inode_unlinked() as well,
> >> resulting in all inodes being marked dirty whether then needed
> >> updating or not.
> >>
> >> Fix it by making clear_inode_unlinked unconditionally do the clear
> >> (as was done for clear_inode), and move the test to the caller.
> >> Add warnings as well so that this corruption is no longer silently
> >> fixed.
> >>
> >> Reported-by: Dave Chinner <dchinner@redhat.com>
> >> Reviewed-by: Eric Sandeen <sandeen@redhat.com>
> >> [sandeen: rework so clear_inode_unlinked is unconditional]
> >> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> >> diff --git a/repair/dinode.c b/repair/dinode.c
> >> index 379f85c..f466e77 100644
> >> --- a/repair/dinode.c
> >> +++ b/repair/dinode.c
> >> @@ -125,23 +125,16 @@ clear_dinode_core(struct xfs_mount *mp, xfs_dinode_t *dinoc, xfs_ino_t ino_num)
> >>  	return;
> >>  }
> >>  
> >> -static int
> >> +static void
> >>  clear_dinode_unlinked(xfs_mount_t *mp, xfs_dinode_t *dino)
> >>  {
> >>  
> >> -	if (be32_to_cpu(dino->di_next_unlinked) != NULLAGINO)  {
> >> -		if (!no_modify)
> >> -			dino->di_next_unlinked = cpu_to_be32(NULLAGINO);
> >> -		return(1);
> >> -	}
> >> -
> >> -	return(0);
> >> +	dino->di_next_unlinked = cpu_to_be32(NULLAGINO);
> >>  }
> > 
> > What's the point of keeping this wrapper now?
> 
> Not much other than making clear_dinode() sightly prettier.
> 
> Happy to nuke it if preferred.

The code is already a mess with all the no_modify/fix branches and
warnings, so it really doesn't matter that much. Keep it as is...

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com