Re: [PATCH v2 03/11] xfs_repair: validate some of the log space information

From: Allison Henderson <allison.henderson@oracle.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>, sandeen@redhat.com
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH v2 03/11] xfs_repair: validate some of the log space information
Date: Tue, 22 May 2018 20:52:34 -0700	[thread overview]
Message-ID: <5d76f6ae-80f3-38c3-db7e-c55e565b3259@oracle.com> (raw)
In-Reply-To: <20180523031536.GH14384@magnolia>

Ok, looks good.

Reviewed by: Allison Henderson <allison.henderson@oracle.com>

On 05/22/2018 08:15 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Validate the log space information in a similar manner to the kernel so
> that repair will stumble over (and fix) broken log info that prevents
> mounting.  Fixes logsunit fuzz-and-fix failures in xfs/350.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>   repair/globals.h    |    3 ++-
>   repair/sb.c         |   27 +++++++++++++++++++++++++++
>   repair/xfs_repair.c |    2 ++
>   3 files changed, 31 insertions(+), 1 deletion(-)
> 
> diff --git a/repair/globals.h b/repair/globals.h
> index e777ba27..164619b0 100644
> --- a/repair/globals.h
> +++ b/repair/globals.h
> @@ -51,7 +51,8 @@
>   #define XR_BAD_SVN		19	/* bad shared version number */
>   #define XR_BAD_CRC		20	/* Bad CRC */
>   #define XR_BAD_DIR_SIZE_DATA	21	/* Bad directory geometry */
> -#define XR_BAD_ERR_CODE		22	/* Bad error code */
> +#define XR_BAD_LOG_GEOMETRY	22	/* Bad log geometry */
> +#define XR_BAD_ERR_CODE		23	/* Bad error code */
>   
>   /* XFS filesystem (il)legal values */
>   
> diff --git a/repair/sb.c b/repair/sb.c
> index 3dc6538b..ef44e39c 100644
> --- a/repair/sb.c
> +++ b/repair/sb.c
> @@ -298,6 +298,30 @@ sb_validate_ino_align(struct xfs_sb *sb)
>   	return false;
>   }
>   
> +/*
> + * Validate the given log space.  Derived from xfs_log_mount, though we
> + * can't validate the minimum log size until later.  We only do this
> + * validation on V5 filesystems because the kernel doesn't reject malformed
> + * log geometry on older revision filesystems.
> + *
> + * Returns false if the log is garbage.
> + */
> +static bool
> +verify_sb_loginfo(
> +	struct xfs_sb	*sb)
> +{
> +	if (xfs_sb_version_hascrc(sb) &&
> +	    (sb->sb_logblocks == 0 ||
> +	     sb->sb_logblocks > XFS_MAX_LOG_BLOCKS ||
> +	     (sb->sb_logblocks << sb->sb_blocklog) > XFS_MAX_LOG_BYTES))
> +		return false;
> +
> +	if (sb->sb_logsunit > 1 && sb->sb_logsunit % sb->sb_blocksize)
> +		return false;
> +
> +	return true;
> +}
> +
>   /*
>    * verify a superblock -- does not verify root inode #
>    *	can only check that geometry info is internally
> @@ -412,6 +436,9 @@ verify_sb(char *sb_buf, xfs_sb_t *sb, int is_primary_sb)
>   	    (sb->sb_blocklog - sb->sb_inodelog != sb->sb_inopblog))
>   		return XR_BAD_INO_SIZE_DATA;
>   
> +	if (!verify_sb_loginfo(sb))
> +		return XR_BAD_LOG_GEOMETRY;
> +
>   	if (xfs_sb_version_hassector(sb))  {
>   
>   		/* check to make sure log sector is legal 2^N, 9 <= N <= 15 */
> diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
> index ff6a7384..b7c2d267 100644
> --- a/repair/xfs_repair.c
> +++ b/repair/xfs_repair.c
> @@ -155,6 +155,8 @@ err_string(int err_code)
>   			_("bad CRC in superblock");
>   		err_message[XR_BAD_DIR_SIZE_DATA] =
>   			_("inconsistent directory geometry information");
> +		err_message[XR_BAD_LOG_GEOMETRY] =
> +			_("inconsistent log geometry information");
>   		done = 1;
>   	}
>   
> --
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