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

Brian Foster
2015-03-19T16:47:31Z

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@redhat.com>
> ---
> 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@redhat.com>

> + 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
>
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