From: Ben Myers <bpm@sgi.com>
To: Eric Sandeen <sandeen@redhat.com>
Cc: "'linux-xfs@oss.sgi.com'" <linux-xfs@oss.sgi.com>
Subject: Re: [PATCH, RFC] xfs: don't verify checksum on non-V5 superblocks
Date: Thu, 15 Aug 2013 14:45:31 -0500 [thread overview]
Message-ID: <20130815194531.GL12719@sgi.com> (raw)
In-Reply-To: <520D1BA3.1050500@redhat.com>
On Thu, Aug 15, 2013 at 01:19:15PM -0500, Eric Sandeen wrote:
> The current test in xfs_sb_read_verify() will attempt to validate
> an sb checksum if sb_crc is non-zero, even if the superblock is not
> marked as being version 5.
>
> This runs the risk of picking up random garbage in sb_crc for non-V5
> superblocks; such garbage is known to exist in the wild due to prior bugs.
> This will cause verification to fail for otherwise non-fatal reasons.
>
> I'm not sure of the point of trying to validate a non-V5 superblock;
> is there one? Shouldn't this || be an &&? (Can sb_crc validly be
> 0 for a V5 SB?)
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
This looks good to me.
Reviewed-by: Ben Myers <bpm@sgi.com>
> ---
>
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 2b0ba35..5ca299b 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -764,7 +764,7 @@ xfs_sb_read_verify(
> */
> if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
> (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
> - XFS_SB_VERSION_5) ||
> + XFS_SB_VERSION_5) &&
> dsb->sb_crc != 0)) {
>
> if (!xfs_verify_cksum(bp->b_addr, be16_to_cpu(dsb->sb_sectsize),
>
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs
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next prev parent reply other threads:[~2013-08-15 19:45 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-15 18:19 [PATCH, RFC] xfs: don't verify checksum on non-V5 superblocks Eric Sandeen
2013-08-15 19:45 ` Ben Myers [this message]
2013-08-15 21:00 ` Dave Chinner
2013-08-15 21:15 ` Eric Sandeen
2013-08-15 22:41 ` [PATCH, RFC] xfs: be more forgiving of a v4 secondary sb w/ junk in v5 fields Eric Sandeen
2013-08-15 23:15 ` Dave Chinner
2013-09-09 20:33 ` [PATCH V2] " Eric Sandeen
2013-09-09 21:08 ` Mark Tinguely
2013-09-09 21:10 ` Eric Sandeen
2013-09-09 21:16 ` Mark Tinguely
2013-10-31 15:51 ` Ben Myers
2013-10-17 20:17 ` [PATCH, RFC] " Ben Myers
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