xfs: vectorise encoding/decoding directory headers

Conversion from on-disk structures to in-core header structures
currently relies on magic number checks. If the magic number is
wrong, but one of the supported values, we do the wrong thing with
the encode/decode operation. Split these functions so that there are
discrete operations for the specific directory format we are
handling.

In doing this, move all the header encode/decode functions to
xfs_da_format.c as they are directly manipulating the on-disk
format. It should be noted that all the growth in binary size is
from xfs_da_format.c - the rest of the code actaully shrinks.

   text    data     bss     dec     hex filename
 794490   96802    1096  892388   d9de4 fs/xfs/xfs.o.orig
 792986   96802    1096  890884   d9804 fs/xfs/xfs.o.p1
 792350   96802    1096  890248   d9588 fs/xfs/xfs.o.p2
 789293   96802    1096  887191   d8997 fs/xfs/xfs.o.p3
 789005   96802    1096  886903   d8997 fs/xfs/xfs.o.p4
 789061   96802    1096  886959   d88af fs/xfs/xfs.o.p5
 789733   96802    1096  887631   d8b4f fs/xfs/xfs.o.p6
 791421   96802    1096  889319   d91e7 fs/xfs/xfs.o.p7

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, 207 insertions, 2 deletions

diff --git a/fs/xfs/xfs_da_format.c b/fs/xfs/xfs_da_format.c
index 72b48b5ec69a..b232c275791d 100644
--- a/fs/xfs/xfs_da_format.c
+++ b/fs/xfs/xfs_da_format.c
@@ -464,19 +464,84 @@ xfs_dir3_leaf_hdr_size(void)
         return sizeof(struct xfs_dir3_leaf_hdr);
 }
 
-static inline int
+static int
 xfs_dir3_max_leaf_ents(struct xfs_mount *mp)
 {
         return (mp->m_dirblksize - xfs_dir3_leaf_hdr_size()) /
                 (uint)sizeof(struct xfs_dir2_leaf_entry);
 }
 
-static inline struct xfs_dir2_leaf_entry *
+static struct xfs_dir2_leaf_entry *
 xfs_dir3_leaf_ents_p(struct xfs_dir2_leaf *lp)
 {
         return ((struct xfs_dir3_leaf *)lp)->__ents;
 }
 
+static void
+xfs_dir2_leaf_hdr_from_disk(
+        struct xfs_dir3_icleaf_hdr      *to,
+        struct xfs_dir2_leaf            *from)
+{
+        to->forw = be32_to_cpu(from->hdr.info.forw);
+        to->back = be32_to_cpu(from->hdr.info.back);
+        to->magic = be16_to_cpu(from->hdr.info.magic);
+        to->count = be16_to_cpu(from->hdr.count);
+        to->stale = be16_to_cpu(from->hdr.stale);
+
+        ASSERT(to->magic == XFS_DIR2_LEAF1_MAGIC ||
+               to->magic == XFS_DIR2_LEAFN_MAGIC);
+}
+
+static void
+xfs_dir2_leaf_hdr_to_disk(
+        struct xfs_dir2_leaf            *to,
+        struct xfs_dir3_icleaf_hdr      *from)
+{
+        ASSERT(from->magic == XFS_DIR2_LEAF1_MAGIC ||
+               from->magic == XFS_DIR2_LEAFN_MAGIC);
+
+        to->hdr.info.forw = cpu_to_be32(from->forw);
+        to->hdr.info.back = cpu_to_be32(from->back);
+        to->hdr.info.magic = cpu_to_be16(from->magic);
+        to->hdr.count = cpu_to_be16(from->count);
+        to->hdr.stale = cpu_to_be16(from->stale);
+}
+
+static void
+xfs_dir3_leaf_hdr_from_disk(
+        struct xfs_dir3_icleaf_hdr      *to,
+        struct xfs_dir2_leaf            *from)
+{
+        struct xfs_dir3_leaf_hdr *hdr3 = (struct xfs_dir3_leaf_hdr *)from;
+
+        to->forw = be32_to_cpu(hdr3->info.hdr.forw);
+        to->back = be32_to_cpu(hdr3->info.hdr.back);
+        to->magic = be16_to_cpu(hdr3->info.hdr.magic);
+        to->count = be16_to_cpu(hdr3->count);
+        to->stale = be16_to_cpu(hdr3->stale);
+
+        ASSERT(to->magic == XFS_DIR3_LEAF1_MAGIC ||
+               to->magic == XFS_DIR3_LEAFN_MAGIC);
+}
+
+static void
+xfs_dir3_leaf_hdr_to_disk(
+        struct xfs_dir2_leaf            *to,
+        struct xfs_dir3_icleaf_hdr      *from)
+{
+        struct xfs_dir3_leaf_hdr *hdr3 = (struct xfs_dir3_leaf_hdr *)to;
+
+        ASSERT(from->magic == XFS_DIR3_LEAF1_MAGIC ||
+               from->magic == XFS_DIR3_LEAFN_MAGIC);
+
+        hdr3->info.hdr.forw = cpu_to_be32(from->forw);
+        hdr3->info.hdr.back = cpu_to_be32(from->back);
+        hdr3->info.hdr.magic = cpu_to_be16(from->magic);
+        hdr3->count = cpu_to_be16(from->count);
+        hdr3->stale = cpu_to_be16(from->stale);
+}
+
+
 /*
  * Directory/Attribute Node block operations
  */
@@ -504,6 +569,121 @@ xfs_da3_node_tree_p(struct xfs_da_intnode *dap)
         return ((struct xfs_da3_intnode *)dap)->__btree;
 }
 
+static void
+xfs_da2_node_hdr_from_disk(
+        struct xfs_da3_icnode_hdr       *to,
+        struct xfs_da_intnode           *from)
+{
+        ASSERT(from->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
+        to->forw = be32_to_cpu(from->hdr.info.forw);
+        to->back = be32_to_cpu(from->hdr.info.back);
+        to->magic = be16_to_cpu(from->hdr.info.magic);
+        to->count = be16_to_cpu(from->hdr.__count);
+        to->level = be16_to_cpu(from->hdr.__level);
+}
+
+static void
+xfs_da2_node_hdr_to_disk(
+        struct xfs_da_intnode           *to,
+        struct xfs_da3_icnode_hdr       *from)
+{
+        ASSERT(from->magic == XFS_DA_NODE_MAGIC);
+        to->hdr.info.forw = cpu_to_be32(from->forw);
+        to->hdr.info.back = cpu_to_be32(from->back);
+        to->hdr.info.magic = cpu_to_be16(from->magic);
+        to->hdr.__count = cpu_to_be16(from->count);
+        to->hdr.__level = cpu_to_be16(from->level);
+}
+
+static void
+xfs_da3_node_hdr_from_disk(
+        struct xfs_da3_icnode_hdr       *to,
+        struct xfs_da_intnode           *from)
+{
+        struct xfs_da3_node_hdr *hdr3 = (struct xfs_da3_node_hdr *)from;
+
+        ASSERT(from->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC));
+        to->forw = be32_to_cpu(hdr3->info.hdr.forw);
+        to->back = be32_to_cpu(hdr3->info.hdr.back);
+        to->magic = be16_to_cpu(hdr3->info.hdr.magic);
+        to->count = be16_to_cpu(hdr3->__count);
+        to->level = be16_to_cpu(hdr3->__level);
+}
+
+static void
+xfs_da3_node_hdr_to_disk(
+        struct xfs_da_intnode           *to,
+        struct xfs_da3_icnode_hdr       *from)
+{
+        struct xfs_da3_node_hdr *hdr3 = (struct xfs_da3_node_hdr *)to;
+
+        ASSERT(from->magic == XFS_DA3_NODE_MAGIC);
+        hdr3->info.hdr.forw = cpu_to_be32(from->forw);
+        hdr3->info.hdr.back = cpu_to_be32(from->back);
+        hdr3->info.hdr.magic = cpu_to_be16(from->magic);
+        hdr3->__count = cpu_to_be16(from->count);
+        hdr3->__level = cpu_to_be16(from->level);
+}
+
+
+/*
+ * Directory free space block operations
+ */
+static void
+xfs_dir2_free_hdr_from_disk(
+        struct xfs_dir3_icfree_hdr      *to,
+        struct xfs_dir2_free            *from)
+{
+        to->magic = be32_to_cpu(from->hdr.magic);
+        to->firstdb = be32_to_cpu(from->hdr.firstdb);
+        to->nvalid = be32_to_cpu(from->hdr.nvalid);
+        to->nused = be32_to_cpu(from->hdr.nused);
+        ASSERT(to->magic == XFS_DIR2_FREE_MAGIC);
+}
+
+static void
+xfs_dir2_free_hdr_to_disk(
+        struct xfs_dir2_free            *to,
+        struct xfs_dir3_icfree_hdr      *from)
+{
+        ASSERT(from->magic == XFS_DIR2_FREE_MAGIC);
+
+        to->hdr.magic = cpu_to_be32(from->magic);
+        to->hdr.firstdb = cpu_to_be32(from->firstdb);
+        to->hdr.nvalid = cpu_to_be32(from->nvalid);
+        to->hdr.nused = cpu_to_be32(from->nused);
+}
+
+static void
+xfs_dir3_free_hdr_from_disk(
+        struct xfs_dir3_icfree_hdr      *to,
+        struct xfs_dir2_free            *from)
+{
+        struct xfs_dir3_free_hdr *hdr3 = (struct xfs_dir3_free_hdr *)from;
+
+        to->magic = be32_to_cpu(hdr3->hdr.magic);
+        to->firstdb = be32_to_cpu(hdr3->firstdb);
+        to->nvalid = be32_to_cpu(hdr3->nvalid);
+        to->nused = be32_to_cpu(hdr3->nused);
+
+        ASSERT(to->magic == XFS_DIR3_FREE_MAGIC);
+}
+
+static void
+xfs_dir3_free_hdr_to_disk(
+        struct xfs_dir2_free            *to,
+        struct xfs_dir3_icfree_hdr      *from)
+{
+        struct xfs_dir3_free_hdr *hdr3 = (struct xfs_dir3_free_hdr *)to;
+
+        ASSERT(from->magic == XFS_DIR3_FREE_MAGIC);
+
+        hdr3->hdr.magic = cpu_to_be32(from->magic);
+        hdr3->firstdb = cpu_to_be32(from->firstdb);
+        hdr3->nvalid = cpu_to_be32(from->nvalid);
+        hdr3->nused = cpu_to_be32(from->nused);
+}
+
 const struct xfs_dir_ops xfs_dir2_ops = {
         .sf_entsize = xfs_dir2_sf_entsize,
         .sf_nextentry = xfs_dir2_sf_nextentry,
@@ -532,11 +712,18 @@ const struct xfs_dir_ops xfs_dir2_ops = {
         .data_unused_p = xfs_dir2_data_unused_p,
 
         .leaf_hdr_size = xfs_dir2_leaf_hdr_size,
+        .leaf_hdr_to_disk = xfs_dir2_leaf_hdr_to_disk,
+        .leaf_hdr_from_disk = xfs_dir2_leaf_hdr_from_disk,
         .leaf_max_ents = xfs_dir2_max_leaf_ents,
         .leaf_ents_p = xfs_dir2_leaf_ents_p,
 
         .node_hdr_size = xfs_da2_node_hdr_size,
+        .node_hdr_to_disk = xfs_da2_node_hdr_to_disk,
+        .node_hdr_from_disk = xfs_da2_node_hdr_from_disk,
         .node_tree_p = xfs_da2_node_tree_p,
+
+        .free_hdr_to_disk = xfs_dir2_free_hdr_to_disk,
+        .free_hdr_from_disk = xfs_dir2_free_hdr_from_disk,
 };
 
 const struct xfs_dir_ops xfs_dir2_ftype_ops = {
@@ -567,11 +754,18 @@ const struct xfs_dir_ops xfs_dir2_ftype_ops = {
         .data_unused_p = xfs_dir2_data_unused_p,
 
         .leaf_hdr_size = xfs_dir2_leaf_hdr_size,
+        .leaf_hdr_to_disk = xfs_dir2_leaf_hdr_to_disk,
+        .leaf_hdr_from_disk = xfs_dir2_leaf_hdr_from_disk,
         .leaf_max_ents = xfs_dir2_max_leaf_ents,
         .leaf_ents_p = xfs_dir2_leaf_ents_p,
 
         .node_hdr_size = xfs_da2_node_hdr_size,
+        .node_hdr_to_disk = xfs_da2_node_hdr_to_disk,
+        .node_hdr_from_disk = xfs_da2_node_hdr_from_disk,
         .node_tree_p = xfs_da2_node_tree_p,
+
+        .free_hdr_to_disk = xfs_dir2_free_hdr_to_disk,
+        .free_hdr_from_disk = xfs_dir2_free_hdr_from_disk,
 };
 
 const struct xfs_dir_ops xfs_dir3_ops = {
@@ -602,20 +796,31 @@ const struct xfs_dir_ops xfs_dir3_ops = {
         .data_unused_p = xfs_dir3_data_unused_p,
 
         .leaf_hdr_size = xfs_dir3_leaf_hdr_size,
+        .leaf_hdr_to_disk = xfs_dir3_leaf_hdr_to_disk,
+        .leaf_hdr_from_disk = xfs_dir3_leaf_hdr_from_disk,
         .leaf_max_ents = xfs_dir3_max_leaf_ents,
         .leaf_ents_p = xfs_dir3_leaf_ents_p,
 
         .node_hdr_size = xfs_da3_node_hdr_size,
+        .node_hdr_to_disk = xfs_da3_node_hdr_to_disk,
+        .node_hdr_from_disk = xfs_da3_node_hdr_from_disk,
         .node_tree_p = xfs_da3_node_tree_p,
+
+        .free_hdr_to_disk = xfs_dir3_free_hdr_to_disk,
+        .free_hdr_from_disk = xfs_dir3_free_hdr_from_disk,
 };
 
 const struct xfs_dir_ops xfs_dir2_nondir_ops = {
         .node_hdr_size = xfs_da2_node_hdr_size,
+        .node_hdr_to_disk = xfs_da2_node_hdr_to_disk,
+        .node_hdr_from_disk = xfs_da2_node_hdr_from_disk,
         .node_tree_p = xfs_da2_node_tree_p,
 };
 
 const struct xfs_dir_ops xfs_dir3_nondir_ops = {
         .node_hdr_size = xfs_da3_node_hdr_size,
+        .node_hdr_to_disk = xfs_da3_node_hdr_to_disk,
+        .node_hdr_from_disk = xfs_da3_node_hdr_from_disk,
         .node_tree_p = xfs_da3_node_tree_p,
 };