nilfs2: remove bmap pointer operations

Previously, the bmap codes of nilfs used three types of function
tables.  The abuse of indirect function calls decreased source
readability and suffered many indirect jumps which would confuse
branch prediction of processors.

This eliminates one type of the function tables,
nilfs_bmap_ptr_operations, which was used to dispatch low level
pointer operations of the nilfs bmap.

This adds a new integer variable "b_ptr_type" to nilfs_bmap struct,
and uses the value to select the pointer operations.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 46 insertions, 54 deletions

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index f5a0ec64e1a..20e3fd0f4d4 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -917,8 +917,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
                 path[level].bp_newreq.bpr_ptr =
                         btree->bt_ops->btop_find_target(btree, path, key);
 
-        ret = btree->bt_bmap.b_pops->bpop_prepare_alloc_ptr(
-                &btree->bt_bmap, &path[level].bp_newreq);
+        ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
+                                           &path[level].bp_newreq);
         if (ret < 0)
                 goto err_out_data;
 
@@ -976,8 +976,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
                 /* split */
                 path[level].bp_newreq.bpr_ptr =
                         path[level - 1].bp_newreq.bpr_ptr + 1;
-                ret = btree->bt_bmap.b_pops->bpop_prepare_alloc_ptr(
-                        &btree->bt_bmap, &path[level].bp_newreq);
+                ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
+                                                   &path[level].bp_newreq);
                 if (ret < 0)
                         goto err_out_child_node;
                 ret = nilfs_btree_get_new_block(btree,
@@ -1008,8 +1008,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 
         /* grow */
         path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
-        ret = btree->bt_bmap.b_pops->bpop_prepare_alloc_ptr(
-                &btree->bt_bmap, &path[level].bp_newreq);
+        ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
+                                           &path[level].bp_newreq);
         if (ret < 0)
                 goto err_out_child_node;
         ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
@@ -1037,18 +1037,16 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 
         /* error */
  err_out_curr_node:
-        btree->bt_bmap.b_pops->bpop_abort_alloc_ptr(&btree->bt_bmap,
-                                                    &path[level].bp_newreq);
+        nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq);
  err_out_child_node:
         for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
                 nilfs_btnode_delete(path[level].bp_sib_bh);
-                btree->bt_bmap.b_pops->bpop_abort_alloc_ptr(
-                        &btree->bt_bmap, &path[level].bp_newreq);
+                nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap,
+                                           &path[level].bp_newreq);
 
         }
 
-        btree->bt_bmap.b_pops->bpop_abort_alloc_ptr(&btree->bt_bmap,
-                                                       &path[level].bp_newreq);
+        nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq);
  err_out_data:
         *levelp = level;
         stats->bs_nblocks = 0;
@@ -1067,8 +1065,8 @@ static void nilfs_btree_commit_insert(struct nilfs_btree *btree,
                 btree->bt_ops->btop_set_target(btree, key, ptr);
 
         for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
-                btree->bt_bmap.b_pops->bpop_commit_alloc_ptr(
-                        &btree->bt_bmap, &path[level - 1].bp_newreq);
+                nilfs_bmap_commit_alloc_ptr(&btree->bt_bmap,
+                                            &path[level - 1].bp_newreq);
                 path[level].bp_op(btree, path, level, &key, &ptr);
         }
 
@@ -1312,12 +1310,10 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
                 path[level].bp_oldreq.bpr_ptr =
                         nilfs_btree_node_get_ptr(btree, node,
                                                  path[level].bp_index);
-                if (btree->bt_bmap.b_pops->bpop_prepare_end_ptr != NULL) {
-                        ret = btree->bt_bmap.b_pops->bpop_prepare_end_ptr(
-                                &btree->bt_bmap, &path[level].bp_oldreq);
-                        if (ret < 0)
-                                goto err_out_child_node;
-                }
+                ret = nilfs_bmap_prepare_end_ptr(&btree->bt_bmap,
+                                                 &path[level].bp_oldreq);
+                if (ret < 0)
+                        goto err_out_child_node;
 
                 if (nilfs_btree_node_get_nchildren(btree, node) >
                     nilfs_btree_node_nchildren_min(btree, node)) {
@@ -1391,12 +1387,12 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
         node = nilfs_btree_get_root(btree);
         path[level].bp_oldreq.bpr_ptr =
                 nilfs_btree_node_get_ptr(btree, node, path[level].bp_index);
-        if (btree->bt_bmap.b_pops->bpop_prepare_end_ptr != NULL) {
-                ret = btree->bt_bmap.b_pops->bpop_prepare_end_ptr(
-                        &btree->bt_bmap, &path[level].bp_oldreq);
-                if (ret < 0)
-                        goto err_out_child_node;
-        }
+
+        ret = nilfs_bmap_prepare_end_ptr(&btree->bt_bmap,
+                                         &path[level].bp_oldreq);
+        if (ret < 0)
+                goto err_out_child_node;
+
         /* child of the root node is deleted */
         path[level].bp_op = nilfs_btree_do_delete;
         stats->bs_nblocks++;
@@ -1408,15 +1404,12 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 
         /* error */
  err_out_curr_node:
-        if (btree->bt_bmap.b_pops->bpop_abort_end_ptr != NULL)
-                btree->bt_bmap.b_pops->bpop_abort_end_ptr(
-                        &btree->bt_bmap, &path[level].bp_oldreq);
+        nilfs_bmap_abort_end_ptr(&btree->bt_bmap, &path[level].bp_oldreq);
  err_out_child_node:
         for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
                 brelse(path[level].bp_sib_bh);
-                if (btree->bt_bmap.b_pops->bpop_abort_end_ptr != NULL)
-                        btree->bt_bmap.b_pops->bpop_abort_end_ptr(
-                                &btree->bt_bmap, &path[level].bp_oldreq);
+                nilfs_bmap_abort_end_ptr(&btree->bt_bmap,
+                                         &path[level].bp_oldreq);
         }
         *levelp = level;
         stats->bs_nblocks = 0;
@@ -1430,9 +1423,8 @@ static void nilfs_btree_commit_delete(struct nilfs_btree *btree,
         int level;
 
         for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
-                if (btree->bt_bmap.b_pops->bpop_commit_end_ptr != NULL)
-                        btree->bt_bmap.b_pops->bpop_commit_end_ptr(
-                                &btree->bt_bmap, &path[level].bp_oldreq);
+                nilfs_bmap_commit_end_ptr(&btree->bt_bmap,
+                                          &path[level].bp_oldreq);
                 path[level].bp_op(btree, path, level, NULL, NULL);
         }
 
@@ -1597,7 +1589,7 @@ nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
         if (btree->bt_ops->btop_find_target != NULL)
                 dreq->bpr_ptr
                         = btree->bt_ops->btop_find_target(btree, NULL, key);
-        ret = bmap->b_pops->bpop_prepare_alloc_ptr(bmap, dreq);
+        ret = nilfs_bmap_prepare_alloc_ptr(bmap, dreq);
         if (ret < 0)
                 return ret;
 
@@ -1605,7 +1597,7 @@ nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
         stats->bs_nblocks++;
         if (nreq != NULL) {
                 nreq->bpr_ptr = dreq->bpr_ptr + 1;
-                ret = bmap->b_pops->bpop_prepare_alloc_ptr(bmap, nreq);
+                ret = nilfs_bmap_prepare_alloc_ptr(bmap, nreq);
                 if (ret < 0)
                         goto err_out_dreq;
 
@@ -1622,9 +1614,9 @@ nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
 
         /* error */
  err_out_nreq:
-        bmap->b_pops->bpop_abort_alloc_ptr(bmap, nreq);
+        nilfs_bmap_abort_alloc_ptr(bmap, nreq);
  err_out_dreq:
-        bmap->b_pops->bpop_abort_alloc_ptr(bmap, dreq);
+        nilfs_bmap_abort_alloc_ptr(bmap, dreq);
         stats->bs_nblocks = 0;
         return ret;
 
@@ -1654,8 +1646,8 @@ nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *bmap,
         btree = (struct nilfs_btree *)bmap;
         nilfs_btree_init(bmap);
         if (nreq != NULL) {
-                bmap->b_pops->bpop_commit_alloc_ptr(bmap, dreq);
-                bmap->b_pops->bpop_commit_alloc_ptr(bmap, nreq);
+                nilfs_bmap_commit_alloc_ptr(bmap, dreq);
+                nilfs_bmap_commit_alloc_ptr(bmap, nreq);
 
                 /* create child node at level 1 */
                 lock_buffer(bh);
@@ -1677,7 +1669,7 @@ nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *bmap,
                 nilfs_btree_node_init(btree, node, NILFS_BTREE_NODE_ROOT,
                                       2, 1, &keys[0], &tmpptr);
         } else {
-                bmap->b_pops->bpop_commit_alloc_ptr(bmap, dreq);
+                nilfs_bmap_commit_alloc_ptr(bmap, dreq);
 
                 /* create root node at level 1 */
                 node = nilfs_btree_get_root(btree);
@@ -1758,9 +1750,9 @@ static int nilfs_btree_prepare_update_v(struct nilfs_btree *btree,
                 nilfs_btree_node_get_ptr(btree, parent,
                                          path[level + 1].bp_index);
         path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1;
-        ret = nilfs_bmap_prepare_update(&btree->bt_bmap,
-                                        &path[level].bp_oldreq,
-                                        &path[level].bp_newreq);
+        ret = nilfs_bmap_prepare_update_v(&btree->bt_bmap,
+                                          &path[level].bp_oldreq,
+                                          &path[level].bp_newreq);
         if (ret < 0)
                 return ret;
 
@@ -1772,9 +1764,9 @@ static int nilfs_btree_prepare_update_v(struct nilfs_btree *btree,
                         &NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
                         &path[level].bp_ctxt);
                 if (ret < 0) {
-                        nilfs_bmap_abort_update(&btree->bt_bmap,
-                                                &path[level].bp_oldreq,
-                                                &path[level].bp_newreq);
+                        nilfs_bmap_abort_update_v(&btree->bt_bmap,
+                                                  &path[level].bp_oldreq,
+                                                  &path[level].bp_newreq);
                         return ret;
                 }
         }
@@ -1788,9 +1780,9 @@ static void nilfs_btree_commit_update_v(struct nilfs_btree *btree,
 {
         struct nilfs_btree_node *parent;
 
-        nilfs_bmap_commit_update(&btree->bt_bmap,
-                                 &path[level].bp_oldreq,
-                                 &path[level].bp_newreq);
+        nilfs_bmap_commit_update_v(&btree->bt_bmap,
+                                   &path[level].bp_oldreq,
+                                   &path[level].bp_newreq);
 
         if (buffer_nilfs_node(path[level].bp_bh)) {
                 nilfs_btnode_commit_change_key(
@@ -1809,9 +1801,9 @@ static void nilfs_btree_abort_update_v(struct nilfs_btree *btree,
                                        struct nilfs_btree_path *path,
                                        int level)
 {
-        nilfs_bmap_abort_update(&btree->bt_bmap,
-                                &path[level].bp_oldreq,
-                                &path[level].bp_newreq);
+        nilfs_bmap_abort_update_v(&btree->bt_bmap,
+                                  &path[level].bp_oldreq,
+                                  &path[level].bp_newreq);
         if (buffer_nilfs_node(path[level].bp_bh))
                 nilfs_btnode_abort_change_key(
                         &NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,