xfs
[Top] [All Lists]

Re: [PATCH 13/13] xfs_repair: validate & fix inode CRCs

To: Eric Sandeen <sandeen@xxxxxxxxxx>
Subject: Re: [PATCH 13/13] xfs_repair: validate & fix inode CRCs
From: Brian Foster <bfoster@xxxxxxxxxx>
Date: Thu, 19 Mar 2015 12:47:27 -0400
Cc: xfs@xxxxxxxxxxx
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <1426624395-8258-14-git-send-email-sandeen@xxxxxxxxxx>
References: <1426624395-8258-1-git-send-email-sandeen@xxxxxxxxxx> <1426624395-8258-14-git-send-email-sandeen@xxxxxxxxxx>
User-agent: Mutt/1.5.23 (2014-03-12)
On Tue, Mar 17, 2015 at 03:33:15PM -0500, Eric Sandeen wrote:
> xfs_repair doesn't ever check an inode's CRC, so it never repairs
> them.  If the root inode or realtime inodes have bad crcs, the
> fs won't even mount and can't be fixed (without using xfs_db).
> 
> It's fairly straightforward to just test the inode CRC before
> we do any other checking or modification of the inode, and
> just mark it dirty if it's wrong and needs to be re-written.
> 
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> ---
>  repair/dinode.c |   24 ++++++++++++++++++++++++
>  1 files changed, 24 insertions(+), 0 deletions(-)
> 
> diff --git a/repair/dinode.c b/repair/dinode.c
> index 5d9094b..05db838 100644
> --- a/repair/dinode.c
> +++ b/repair/dinode.c
> @@ -2291,6 +2291,30 @@ process_dinode_int(xfs_mount_t *mp,
>        */
>       ASSERT(uncertain == 0 || verify_mode != 0);
>  
> +     /*
> +      * This is the only valid point to check the CRC; after this we may have
> +      * made changes which invalidate it, and the CRC is only updated again
> +      * when it gets written out.
> +      *
> +      * Of course if we make any modifications after this, the inode gets
> +      * rewritten, and the CRC is updated automagically.
> +      */
> +     if (xfs_sb_version_hascrc(&mp->m_sb) &&
> +         !xfs_verify_cksum((char *)dino, mp->m_sb.sb_inodesize,
> +                             XFS_DINODE_CRC_OFF)) {

   ^^^^^^ whitespace ;)

Otherwise looks good to me:

Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>

> +             retval = 1;
> +             if (!uncertain)
> +                     do_warn(_("bad CRC for inode %" PRIu64 "%c"),
> +                             lino, verify_mode ? '\n' : ',');
> +             if (!verify_mode) {
> +                     if (!no_modify) {
> +                             do_warn(_(" will rewrite\n"));
> +                             *dirty = 1;
> +                     } else
> +                             do_warn(_(" would rewrite\n"));
> +             }
> +     }
> +
>       if (be16_to_cpu(dino->di_magic) != XFS_DINODE_MAGIC)  {
>               retval = 1;
>               if (!uncertain)
> -- 
> 1.7.1
> 
> _______________________________________________
> xfs mailing list
> xfs@xxxxxxxxxxx
> http://oss.sgi.com/mailman/listinfo/xfs

<Prev in Thread] Current Thread [Next in Thread>