xfs: add CRC checks to the AGF

[deliverable/linux.git] / fs / xfs / xfs_alloc.c

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 0ad23253e8b1ed1da6c723b44d828fbb7e743350..c34f799aa92e76f987733807e8935cdeea64bea2 100644 (file)
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -33,7 +33,9 @@
 #include "xfs_alloc.h"
 #include "xfs_extent_busy.h"
 #include "xfs_error.h"
+#include "xfs_cksum.h"
 #include "xfs_trace.h"
+#include "xfs_buf_item.h"
 
 struct workqueue_struct *xfs_alloc_wq;
 
@@ -842,7 +844,7 @@ xfs_alloc_ag_vextent_near(
         */
        int             dofirst;        /* set to do first algorithm */
 
-       dofirst = random32() & 1;
+       dofirst = prandom_u32() & 1;
 #endif
 
 restart:
@@ -2058,11 +2060,14 @@ xfs_alloc_log_agf(
                offsetof(xfs_agf_t, agf_freeblks),
                offsetof(xfs_agf_t, agf_longest),
                offsetof(xfs_agf_t, agf_btreeblks),
+               offsetof(xfs_agf_t, agf_uuid),
                sizeof(xfs_agf_t)
        };
 
        trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
 
+       xfs_trans_buf_set_type(tp, bp, XFS_BLF_AGF_BUF);
+
        xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
        xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
 }
@@ -2143,22 +2148,24 @@ xfs_alloc_put_freelist(
        return 0;
 }
 
-static void
+static bool
 xfs_agf_verify(
+       struct xfs_mount *mp,
        struct xfs_buf  *bp)
  {
-       struct xfs_mount *mp = bp->b_target->bt_mount;
-       struct xfs_agf  *agf;
-       int             agf_ok;
+       struct xfs_agf  *agf = XFS_BUF_TO_AGF(bp);
 
-       agf = XFS_BUF_TO_AGF(bp);
+       if (xfs_sb_version_hascrc(&mp->m_sb) &&
+           !uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_uuid))
+                       return false;
 
-       agf_ok = agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
-               XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
-               be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
-               be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
-               be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
-               be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp);
+       if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
+             XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
+             be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
+             be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
+             be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
+             be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
+               return false;
 
        /*
         * during growfs operations, the perag is not fully initialised,
@@ -2166,33 +2173,58 @@ xfs_agf_verify(
         * use it by using uncached buffers that don't have the perag attached
         * so we can detect and avoid this problem.
         */
-       if (bp->b_pag)
-               agf_ok = agf_ok && be32_to_cpu(agf->agf_seqno) ==
-                                               bp->b_pag->pag_agno;
+       if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
+               return false;
 
-       if (xfs_sb_version_haslazysbcount(&mp->m_sb))
-               agf_ok = agf_ok && be32_to_cpu(agf->agf_btreeblks) <=
-                                               be32_to_cpu(agf->agf_length);
+       if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
+           be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
+               return false;
+
+       return true;;
 
-       if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
-                       XFS_RANDOM_ALLOC_READ_AGF))) {
-               XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, agf);
-               xfs_buf_ioerror(bp, EFSCORRUPTED);
-       }
 }
 
 static void
 xfs_agf_read_verify(
        struct xfs_buf  *bp)
 {
-       xfs_agf_verify(bp);
+       struct xfs_mount *mp = bp->b_target->bt_mount;
+       int             agf_ok = 1;
+
+       if (xfs_sb_version_hascrc(&mp->m_sb))
+               agf_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+                                         offsetof(struct xfs_agf, agf_crc));
+
+       agf_ok = agf_ok && xfs_agf_verify(mp, bp);
+
+       if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
+                       XFS_RANDOM_ALLOC_READ_AGF))) {
+               XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+               xfs_buf_ioerror(bp, EFSCORRUPTED);
+       }
 }
 
 static void
 xfs_agf_write_verify(
        struct xfs_buf  *bp)
 {
-       xfs_agf_verify(bp);
+       struct xfs_mount *mp = bp->b_target->bt_mount;
+       struct xfs_buf_log_item *bip = bp->b_fspriv;
+
+       if (!xfs_agf_verify(mp, bp)) {
+               XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+               xfs_buf_ioerror(bp, EFSCORRUPTED);
+               return;
+       }
+
+       if (!xfs_sb_version_hascrc(&mp->m_sb))
+               return;
+
+       if (bip)
+               XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+
+       xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+                        offsetof(struct xfs_agf, agf_crc));
 }
 
 const struct xfs_buf_ops xfs_agf_buf_ops = {