xfs: add CRC checking to dir2 free blocks

This addition follows the same pattern as the dir2 block CRCs, but
with a few differences. The main difference is that the free block
header is different between the v2 and v3 formats, so an "in-core"
free block header has been added and _todisk/_from_disk functions
used to abstract the differences in structure format from the code.
This is similar to the on-disk superblock versus the in-core
superblock setup. The in-core strucutre is populated when the buffer
is read from disk, all the in memory checks and modifications are
done on the in-core version of the structure which is written back
to the buffer before the buffer is logged.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c
index ef163f06fd16..979735b0c76d 100644
--- a/fs/xfs/xfs_dir2_leaf.c
+++ b/fs/xfs/xfs_dir2_leaf.c
@@ -1881,6 +1881,7 @@ xfs_dir2_node_to_leaf(
         xfs_mount_t             *mp;            /* filesystem mount point */
         int                     rval;           /* successful free trim? */
         xfs_trans_t             *tp;            /* transaction pointer */
+        struct xfs_dir3_icfree_hdr freehdr;
 
         /*
          * There's more than a leaf level in the btree, so there must
@@ -1938,15 +1939,15 @@ xfs_dir2_node_to_leaf(
         if (error)
                 return error;
         free = fbp->b_addr;
-        ASSERT(free->hdr.magic == cpu_to_be32(XFS_DIR2_FREE_MAGIC));
-        ASSERT(!free->hdr.firstdb);
+        xfs_dir3_free_hdr_from_disk(&freehdr, free);
+
+        ASSERT(!freehdr.firstdb);
 
         /*
          * Now see if the leafn and free data will fit in a leaf1.
          * If not, release the buffer and give up.
          */
-        if (xfs_dir2_leaf_size(&leaf->hdr, be32_to_cpu(free->hdr.nvalid)) >
-                        mp->m_dirblksize) {
+        if (xfs_dir2_leaf_size(&leaf->hdr, freehdr.nvalid) > mp->m_dirblksize) {
                 xfs_trans_brelse(tp, fbp);
                 return 0;
         }
@@ -1967,12 +1968,12 @@ xfs_dir2_node_to_leaf(
          * Set up the leaf tail from the freespace block.
          */
         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
-        ltp->bestcount = free->hdr.nvalid;
+        ltp->bestcount = cpu_to_be32(freehdr.nvalid);
         /*
          * Set up the leaf bests table.
          */
-        memcpy(xfs_dir2_leaf_bests_p(ltp), free->bests,
-                be32_to_cpu(ltp->bestcount) * sizeof(xfs_dir2_data_off_t));
+        memcpy(xfs_dir2_leaf_bests_p(ltp), xfs_dir3_free_bests_p(mp, free),
+                freehdr.nvalid * sizeof(xfs_dir2_data_off_t));
         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
         xfs_dir2_leaf_log_tail(tp, lbp);
         xfs_dir2_leaf_check(dp, lbp);