From 77c95bba013089fa868217283eb6d98a05913e53 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 3 Apr 2013 16:11:14 +1100 Subject: xfs: add CRC checks to the AGFL Add CRC checks, location information and a magic number to the AGFL. Previously the AGFL was just a block containing nothing but the free block pointers. The new AGFL has a real header with the usual boilerplate instead, so that we can verify it's not corrupted and written into the right place. [dchinner@redhat.com] Added LSN field, reworked significantly to fit into new verifier structure and growfs structure, enabled full verifier functionality now there is a header to verify and we can guarantee an initialised AGFL. Signed-off-by: Christoph Hellwig Signed-off-by: Dave Chinner Reviewed-by: Ben Myers Signed-off-by: Ben Myers --- fs/xfs/xfs_ag.h | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) (limited to 'fs/xfs/xfs_ag.h') diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h index 9f4815e..272ef09 100644 --- a/fs/xfs/xfs_ag.h +++ b/fs/xfs/xfs_ag.h @@ -30,6 +30,7 @@ struct xfs_trans; #define XFS_AGF_MAGIC 0x58414746 /* 'XAGF' */ #define XFS_AGI_MAGIC 0x58414749 /* 'XAGI' */ +#define XFS_AGFL_MAGIC 0x5841464c /* 'XAFL' */ #define XFS_AGF_VERSION 1 #define XFS_AGI_VERSION 1 @@ -190,11 +191,31 @@ extern const struct xfs_buf_ops xfs_agi_buf_ops; */ #define XFS_AGFL_DADDR(mp) ((xfs_daddr_t)(3 << (mp)->m_sectbb_log)) #define XFS_AGFL_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp)) -#define XFS_AGFL_SIZE(mp) ((mp)->m_sb.sb_sectsize / sizeof(xfs_agblock_t)) #define XFS_BUF_TO_AGFL(bp) ((xfs_agfl_t *)((bp)->b_addr)) +#define XFS_BUF_TO_AGFL_BNO(mp, bp) \ + (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \ + &(XFS_BUF_TO_AGFL(bp)->agfl_bno[0]) : \ + (__be32 *)(bp)->b_addr) + +/* + * Size of the AGFL. For CRC-enabled filesystes we steal a couple of + * slots in the beginning of the block for a proper header with the + * location information and CRC. + */ +#define XFS_AGFL_SIZE(mp) \ + (((mp)->m_sb.sb_sectsize - \ + (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \ + sizeof(struct xfs_agfl) : 0)) / \ + sizeof(xfs_agblock_t)) + typedef struct xfs_agfl { - __be32 agfl_bno[1]; /* actually XFS_AGFL_SIZE(mp) */ + __be32 agfl_magicnum; + __be32 agfl_seqno; + uuid_t agfl_uuid; + __be64 agfl_lsn; + __be32 agfl_crc; + __be32 agfl_bno[]; /* actually XFS_AGFL_SIZE(mp) */ } xfs_agfl_t; /* -- cgit v1.1