xfs: add CRC checking to dir2 leaf blocks

This addition follows the same pattern as the dir2 block CRCs.
Seeing as both LEAF1 and LEAFN types need to changed at the same
time, this is a pretty large amount of change. leaf block headers
need to be abstracted away from the on-disk structures (struct
xfs_dir3_icleaf_hdr), as do the base leaf entry locations.

This header abstract allows the in-core header and leaf entry
location to be passed around instead of the leaf block itself. This
saves a lot of converting individual variables from on-disk format
to host format where they are used, so there's a good chance that
the compiler will be able to produce much more optimal code as it's
not having to byteswap variables all over the place.

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, 53 insertions, 7 deletions

diff --git a/fs/xfs/xfs_dir2_format.h b/fs/xfs/xfs_dir2_format.h
index 0ac09502b830..7b986d334b33 100644
--- a/fs/xfs/xfs_dir2_format.h
+++ b/fs/xfs/xfs_dir2_format.h
@@ -470,6 +470,21 @@ typedef struct xfs_dir2_leaf_hdr {
         __be16                  stale;          /* count of stale entries */
 } xfs_dir2_leaf_hdr_t;
 
+struct xfs_dir3_leaf_hdr {
+        struct xfs_da3_blkinfo  info;           /* header for da routines */
+        __be16                  count;          /* count of entries */
+        __be16                  stale;          /* count of stale entries */
+        __be32                  pad;
+};
+
+struct xfs_dir3_icleaf_hdr {
+        __uint32_t              forw;
+        __uint32_t              back;
+        __uint16_t              magic;
+        __uint16_t              count;
+        __uint16_t              stale;
+};
+
 /*
  * Leaf block entry.
  */
@@ -489,23 +504,50 @@ typedef struct xfs_dir2_leaf_tail {
  * Leaf block.
  */
 typedef struct xfs_dir2_leaf {
-        xfs_dir2_leaf_hdr_t     hdr;            /* leaf header */
-        xfs_dir2_leaf_entry_t   ents[];         /* entries */
+        xfs_dir2_leaf_hdr_t     hdr;                    /* leaf header */
+        xfs_dir2_leaf_entry_t   __ents[];               /* entries */
 } xfs_dir2_leaf_t;
 
-/*
- * DB blocks here are logical directory block numbers, not filesystem blocks.
- */
+struct xfs_dir3_leaf {
+        struct xfs_dir3_leaf_hdr        hdr;            /* leaf header */
+        struct xfs_dir2_leaf_entry      __ents[];       /* entries */
+};
+
+#define XFS_DIR3_LEAF_CRC_OFF  offsetof(struct xfs_dir3_leaf_hdr, info.crc)
+
+static inline int
+xfs_dir3_leaf_hdr_size(struct xfs_dir2_leaf *lp)
+{
+        if (lp->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) ||
+            lp->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC))
+                return sizeof(struct xfs_dir3_leaf_hdr);
+        return sizeof(struct xfs_dir2_leaf_hdr);
+}
 
-static inline int xfs_dir2_max_leaf_ents(struct xfs_mount *mp)
+static inline int
+xfs_dir3_max_leaf_ents(struct xfs_mount *mp, struct xfs_dir2_leaf *lp)
 {
-        return (mp->m_dirblksize - (uint)sizeof(struct xfs_dir2_leaf_hdr)) /
+        return (mp->m_dirblksize - xfs_dir3_leaf_hdr_size(lp)) /
                 (uint)sizeof(struct xfs_dir2_leaf_entry);
 }
 
 /*
  * Get address of the bestcount field in the single-leaf block.
  */
+static inline struct xfs_dir2_leaf_entry *
+xfs_dir3_leaf_ents_p(struct xfs_dir2_leaf *lp)
+{
+        if (lp->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) ||
+            lp->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
+                struct xfs_dir3_leaf *lp3 = (struct xfs_dir3_leaf *)lp;
+                return lp3->__ents;
+        }
+        return lp->__ents;
+}
+
+/*
+ * Get address of the bestcount field in the single-leaf block.
+ */
 static inline struct xfs_dir2_leaf_tail *
 xfs_dir2_leaf_tail_p(struct xfs_mount *mp, struct xfs_dir2_leaf *lp)
 {
@@ -524,6 +566,10 @@ xfs_dir2_leaf_bests_p(struct xfs_dir2_leaf_tail *ltp)
 }
 
 /*
+ * DB blocks here are logical directory block numbers, not filesystem blocks.
+ */
+
+/*
  * Convert dataptr to byte in file space
  */
 static inline xfs_dir2_off_t