1 files changed, 208 insertions, 248 deletions

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index aa412724b64e..21ed8ccea4b9 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -71,21 +71,17 @@ void nilfs_btree_path_cache_destroy(void)
         kmem_cache_destroy(nilfs_btree_path_cache);
 }
 
-static inline struct nilfs_btree_path *
-nilfs_btree_alloc_path(const struct nilfs_btree *btree)
+static inline struct nilfs_btree_path *nilfs_btree_alloc_path(void)
 {
-        return (struct nilfs_btree_path *)
-                kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS);
+        return kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS);
 }
 
-static inline void nilfs_btree_free_path(const struct nilfs_btree *btree,
-                                         struct nilfs_btree_path *path)
+static inline void nilfs_btree_free_path(struct nilfs_btree_path *path)
 {
         kmem_cache_free(nilfs_btree_path_cache, path);
 }
 
-static void nilfs_btree_init_path(const struct nilfs_btree *btree,
-                                  struct nilfs_btree_path *path)
+static void nilfs_btree_init_path(struct nilfs_btree_path *path)
 {
         int level;
 
@@ -101,8 +97,7 @@ static void nilfs_btree_init_path(const struct nilfs_btree *btree,
         }
 }
 
-static void nilfs_btree_clear_path(const struct nilfs_btree *btree,
-                                   struct nilfs_btree_path *path)
+static void nilfs_btree_clear_path(struct nilfs_btree_path *path)
 {
         int level;
 
@@ -148,129 +143,110 @@ static int nilfs_btree_get_new_block(const struct nilfs_btree *btree,
 }
 
 static inline int
-nilfs_btree_node_get_flags(const struct nilfs_btree *btree,
-                           const struct nilfs_btree_node *node)
+nilfs_btree_node_get_flags(const struct nilfs_btree_node *node)
 {
         return node->bn_flags;
 }
 
 static inline void
-nilfs_btree_node_set_flags(struct nilfs_btree *btree,
-                           struct nilfs_btree_node *node,
-                           int flags)
+nilfs_btree_node_set_flags(struct nilfs_btree_node *node, int flags)
 {
         node->bn_flags = flags;
 }
 
-static inline int nilfs_btree_node_root(const struct nilfs_btree *btree,
-                                        const struct nilfs_btree_node *node)
+static inline int nilfs_btree_node_root(const struct nilfs_btree_node *node)
 {
-        return nilfs_btree_node_get_flags(btree, node) & NILFS_BTREE_NODE_ROOT;
+        return nilfs_btree_node_get_flags(node) & NILFS_BTREE_NODE_ROOT;
 }
 
 static inline int
-nilfs_btree_node_get_level(const struct nilfs_btree *btree,
-                           const struct nilfs_btree_node *node)
+nilfs_btree_node_get_level(const struct nilfs_btree_node *node)
 {
         return node->bn_level;
 }
 
 static inline void
-nilfs_btree_node_set_level(struct nilfs_btree *btree,
-                           struct nilfs_btree_node *node,
-                           int level)
+nilfs_btree_node_set_level(struct nilfs_btree_node *node, int level)
 {
         node->bn_level = level;
 }
 
 static inline int
-nilfs_btree_node_get_nchildren(const struct nilfs_btree *btree,
-                               const struct nilfs_btree_node *node)
+nilfs_btree_node_get_nchildren(const struct nilfs_btree_node *node)
 {
         return le16_to_cpu(node->bn_nchildren);
 }
 
 static inline void
-nilfs_btree_node_set_nchildren(struct nilfs_btree *btree,
-                               struct nilfs_btree_node *node,
-                               int nchildren)
+nilfs_btree_node_set_nchildren(struct nilfs_btree_node *node, int nchildren)
 {
         node->bn_nchildren = cpu_to_le16(nchildren);
 }
 
-static inline int
-nilfs_btree_node_size(const struct nilfs_btree *btree)
+static inline int nilfs_btree_node_size(const struct nilfs_btree *btree)
 {
         return 1 << btree->bt_bmap.b_inode->i_blkbits;
 }
 
 static inline int
-nilfs_btree_node_nchildren_min(const struct nilfs_btree *btree,
-                               const struct nilfs_btree_node *node)
+nilfs_btree_node_nchildren_min(const struct nilfs_btree_node *node,
+                               const struct nilfs_btree *btree)
 {
-        return nilfs_btree_node_root(btree, node) ?
+        return nilfs_btree_node_root(node) ?
                 NILFS_BTREE_ROOT_NCHILDREN_MIN :
                 NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
 }
 
 static inline int
-nilfs_btree_node_nchildren_max(const struct nilfs_btree *btree,
-                               const struct nilfs_btree_node *node)
+nilfs_btree_node_nchildren_max(const struct nilfs_btree_node *node,
+                               const struct nilfs_btree *btree)
 {
-        return nilfs_btree_node_root(btree, node) ?
+        return nilfs_btree_node_root(node) ?
                 NILFS_BTREE_ROOT_NCHILDREN_MAX :
                 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(btree));
 }
 
 static inline __le64 *
-nilfs_btree_node_dkeys(const struct nilfs_btree *btree,
-                       const struct nilfs_btree_node *node)
+nilfs_btree_node_dkeys(const struct nilfs_btree_node *node)
 {
         return (__le64 *)((char *)(node + 1) +
-                          (nilfs_btree_node_root(btree, node) ?
+                          (nilfs_btree_node_root(node) ?
                            0 : NILFS_BTREE_NODE_EXTRA_PAD_SIZE));
 }
 
 static inline __le64 *
-nilfs_btree_node_dptrs(const struct nilfs_btree *btree,
-                       const struct nilfs_btree_node *node)
+nilfs_btree_node_dptrs(const struct nilfs_btree_node *node,
+                       const struct nilfs_btree *btree)
 {
-        return (__le64 *)(nilfs_btree_node_dkeys(btree, node) +
-                          nilfs_btree_node_nchildren_max(btree, node));
+        return (__le64 *)(nilfs_btree_node_dkeys(node) +
+                          nilfs_btree_node_nchildren_max(node, btree));
 }
 
 static inline __u64
-nilfs_btree_node_get_key(const struct nilfs_btree *btree,
-                         const struct nilfs_btree_node *node, int index)
+nilfs_btree_node_get_key(const struct nilfs_btree_node *node, int index)
 {
-        return nilfs_bmap_dkey_to_key(*(nilfs_btree_node_dkeys(btree, node) +
-                                        index));
+        return nilfs_bmap_dkey_to_key(*(nilfs_btree_node_dkeys(node) + index));
 }
 
 static inline void
-nilfs_btree_node_set_key(struct nilfs_btree *btree,
-                         struct nilfs_btree_node *node, int index, __u64 key)
+nilfs_btree_node_set_key(struct nilfs_btree_node *node, int index, __u64 key)
 {
-        *(nilfs_btree_node_dkeys(btree, node) + index) =
-                nilfs_bmap_key_to_dkey(key);
+        *(nilfs_btree_node_dkeys(node) + index) = nilfs_bmap_key_to_dkey(key);
 }
 
 static inline __u64
 nilfs_btree_node_get_ptr(const struct nilfs_btree *btree,
-                         const struct nilfs_btree_node *node,
-                         int index)
+                         const struct nilfs_btree_node *node, int index)
 {
-        return nilfs_bmap_dptr_to_ptr(*(nilfs_btree_node_dptrs(btree, node) +
+        return nilfs_bmap_dptr_to_ptr(*(nilfs_btree_node_dptrs(node, btree) +
                                         index));
 }
 
 static inline void
 nilfs_btree_node_set_ptr(struct nilfs_btree *btree,
-                         struct nilfs_btree_node *node,
-                         int index,
-                         __u64 ptr)
+                         struct nilfs_btree_node *node, int index, __u64 ptr)
 {
-        *(nilfs_btree_node_dptrs(btree, node) + index) =
+        *(nilfs_btree_node_dptrs(node, btree) + index) =
                 nilfs_bmap_ptr_to_dptr(ptr);
 }
 
@@ -283,12 +259,12 @@ static void nilfs_btree_node_init(struct nilfs_btree *btree,
         __le64 *dptrs;
         int i;
 
-        nilfs_btree_node_set_flags(btree, node, flags);
-        nilfs_btree_node_set_level(btree, node, level);
-        nilfs_btree_node_set_nchildren(btree, node, nchildren);
+        nilfs_btree_node_set_flags(node, flags);
+        nilfs_btree_node_set_level(node, level);
+        nilfs_btree_node_set_nchildren(node, nchildren);
 
-        dkeys = nilfs_btree_node_dkeys(btree, node);
-        dptrs = nilfs_btree_node_dptrs(btree, node);
+        dkeys = nilfs_btree_node_dkeys(node);
+        dptrs = nilfs_btree_node_dptrs(node, btree);
         for (i = 0; i < nchildren; i++) {
                 dkeys[i] = nilfs_bmap_key_to_dkey(keys[i]);
                 dptrs[i] = nilfs_bmap_ptr_to_dptr(ptrs[i]);
@@ -305,13 +281,13 @@ static void nilfs_btree_node_move_left(struct nilfs_btree *btree,
         __le64 *ldptrs, *rdptrs;
         int lnchildren, rnchildren;
 
-        ldkeys = nilfs_btree_node_dkeys(btree, left);
-        ldptrs = nilfs_btree_node_dptrs(btree, left);
-        lnchildren = nilfs_btree_node_get_nchildren(btree, left);
+        ldkeys = nilfs_btree_node_dkeys(left);
+        ldptrs = nilfs_btree_node_dptrs(left, btree);
+        lnchildren = nilfs_btree_node_get_nchildren(left);
 
-        rdkeys = nilfs_btree_node_dkeys(btree, right);
-        rdptrs = nilfs_btree_node_dptrs(btree, right);
-        rnchildren = nilfs_btree_node_get_nchildren(btree, right);
+        rdkeys = nilfs_btree_node_dkeys(right);
+        rdptrs = nilfs_btree_node_dptrs(right, btree);
+        rnchildren = nilfs_btree_node_get_nchildren(right);
 
         memcpy(ldkeys + lnchildren, rdkeys, n * sizeof(*rdkeys));
         memcpy(ldptrs + lnchildren, rdptrs, n * sizeof(*rdptrs));
@@ -320,8 +296,8 @@ static void nilfs_btree_node_move_left(struct nilfs_btree *btree,
 
         lnchildren += n;
         rnchildren -= n;
-        nilfs_btree_node_set_nchildren(btree, left, lnchildren);
-        nilfs_btree_node_set_nchildren(btree, right, rnchildren);
+        nilfs_btree_node_set_nchildren(left, lnchildren);
+        nilfs_btree_node_set_nchildren(right, rnchildren);
 }
 
 /* Assume that the buffer heads corresponding to left and right are locked. */
@@ -334,13 +310,13 @@ static void nilfs_btree_node_move_right(struct nilfs_btree *btree,
         __le64 *ldptrs, *rdptrs;
         int lnchildren, rnchildren;
 
-        ldkeys = nilfs_btree_node_dkeys(btree, left);
-        ldptrs = nilfs_btree_node_dptrs(btree, left);
-        lnchildren = nilfs_btree_node_get_nchildren(btree, left);
+        ldkeys = nilfs_btree_node_dkeys(left);
+        ldptrs = nilfs_btree_node_dptrs(left, btree);
+        lnchildren = nilfs_btree_node_get_nchildren(left);
 
-        rdkeys = nilfs_btree_node_dkeys(btree, right);
-        rdptrs = nilfs_btree_node_dptrs(btree, right);
-        rnchildren = nilfs_btree_node_get_nchildren(btree, right);
+        rdkeys = nilfs_btree_node_dkeys(right);
+        rdptrs = nilfs_btree_node_dptrs(right, btree);
+        rnchildren = nilfs_btree_node_get_nchildren(right);
 
         memmove(rdkeys + n, rdkeys, rnchildren * sizeof(*rdkeys));
         memmove(rdptrs + n, rdptrs, rnchildren * sizeof(*rdptrs));
@@ -349,8 +325,8 @@ static void nilfs_btree_node_move_right(struct nilfs_btree *btree,
 
         lnchildren -= n;
         rnchildren += n;
-        nilfs_btree_node_set_nchildren(btree, left, lnchildren);
-        nilfs_btree_node_set_nchildren(btree, right, rnchildren);
+        nilfs_btree_node_set_nchildren(left, lnchildren);
+        nilfs_btree_node_set_nchildren(right, rnchildren);
 }
 
 /* Assume that the buffer head corresponding to node is locked. */
@@ -362,9 +338,9 @@ static void nilfs_btree_node_insert(struct nilfs_btree *btree,
         __le64 *dptrs;
         int nchildren;
 
-        dkeys = nilfs_btree_node_dkeys(btree, node);
-        dptrs = nilfs_btree_node_dptrs(btree, node);
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
+        dkeys = nilfs_btree_node_dkeys(node);
+        dptrs = nilfs_btree_node_dptrs(node, btree);
+        nchildren = nilfs_btree_node_get_nchildren(node);
         if (index < nchildren) {
                 memmove(dkeys + index + 1, dkeys + index,
                         (nchildren - index) * sizeof(*dkeys));
@@ -374,7 +350,7 @@ static void nilfs_btree_node_insert(struct nilfs_btree *btree,
         dkeys[index] = nilfs_bmap_key_to_dkey(key);
         dptrs[index] = nilfs_bmap_ptr_to_dptr(ptr);
         nchildren++;
-        nilfs_btree_node_set_nchildren(btree, node, nchildren);
+        nilfs_btree_node_set_nchildren(node, nchildren);
 }
 
 /* Assume that the buffer head corresponding to node is locked. */
@@ -388,11 +364,11 @@ static void nilfs_btree_node_delete(struct nilfs_btree *btree,
         __le64 *dptrs;
         int nchildren;
 
-        dkeys = nilfs_btree_node_dkeys(btree, node);
-        dptrs = nilfs_btree_node_dptrs(btree, node);
+        dkeys = nilfs_btree_node_dkeys(node);
+        dptrs = nilfs_btree_node_dptrs(node, btree);
         key = nilfs_bmap_dkey_to_key(dkeys[index]);
         ptr = nilfs_bmap_dptr_to_ptr(dptrs[index]);
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
+        nchildren = nilfs_btree_node_get_nchildren(node);
         if (keyp != NULL)
                 *keyp = key;
         if (ptrp != NULL)
@@ -405,11 +381,10 @@ static void nilfs_btree_node_delete(struct nilfs_btree *btree,
                         (nchildren - index - 1) * sizeof(*dptrs));
         }
         nchildren--;
-        nilfs_btree_node_set_nchildren(btree, node, nchildren);
+        nilfs_btree_node_set_nchildren(node, nchildren);
 }
 
-static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
-                                   const struct nilfs_btree_node *node,
+static int nilfs_btree_node_lookup(const struct nilfs_btree_node *node,
                                    __u64 key, int *indexp)
 {
         __u64 nkey;
@@ -417,12 +392,12 @@ static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
 
         /* binary search */
         low = 0;
-        high = nilfs_btree_node_get_nchildren(btree, node) - 1;
+        high = nilfs_btree_node_get_nchildren(node) - 1;
         index = 0;
         s = 0;
         while (low <= high) {
                 index = (low + high) / 2;
-                nkey = nilfs_btree_node_get_key(btree, node, index);
+                nkey = nilfs_btree_node_get_key(node, index);
                 if (nkey == key) {
                         s = 0;
                         goto out;
@@ -436,9 +411,8 @@ static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
         }
 
         /* adjust index */
-        if (nilfs_btree_node_get_level(btree, node) >
-            NILFS_BTREE_LEVEL_NODE_MIN) {
-                if ((s > 0) && (index > 0))
+        if (nilfs_btree_node_get_level(node) > NILFS_BTREE_LEVEL_NODE_MIN) {
+                if (s > 0 && index > 0)
                         index--;
         } else if (s < 0)
                 index++;
@@ -456,25 +430,20 @@ nilfs_btree_get_root(const struct nilfs_btree *btree)
 }
 
 static inline struct nilfs_btree_node *
-nilfs_btree_get_nonroot_node(const struct nilfs_btree *btree,
-                             const struct nilfs_btree_path *path,
-                             int level)
+nilfs_btree_get_nonroot_node(const struct nilfs_btree_path *path, int level)
 {
         return (struct nilfs_btree_node *)path[level].bp_bh->b_data;
 }
 
 static inline struct nilfs_btree_node *
-nilfs_btree_get_sib_node(const struct nilfs_btree *btree,
-                         const struct nilfs_btree_path *path,
-                         int level)
+nilfs_btree_get_sib_node(const struct nilfs_btree_path *path, int level)
 {
         return (struct nilfs_btree_node *)path[level].bp_sib_bh->b_data;
 }
 
 static inline int nilfs_btree_height(const struct nilfs_btree *btree)
 {
-        return nilfs_btree_node_get_level(btree, nilfs_btree_get_root(btree))
-                + 1;
+        return nilfs_btree_node_get_level(nilfs_btree_get_root(btree)) + 1;
 }
 
 static inline struct nilfs_btree_node *
@@ -484,7 +453,7 @@ nilfs_btree_get_node(const struct nilfs_btree *btree,
 {
         return (level == nilfs_btree_height(btree) - 1) ?
                 nilfs_btree_get_root(btree) :
-                nilfs_btree_get_nonroot_node(btree, path, level);
+                nilfs_btree_get_nonroot_node(path, level);
 }
 
 static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
@@ -496,12 +465,11 @@ static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
         int level, index, found, ret;
 
         node = nilfs_btree_get_root(btree);
-        level = nilfs_btree_node_get_level(btree, node);
-        if ((level < minlevel) ||
-            (nilfs_btree_node_get_nchildren(btree, node) <= 0))
+        level = nilfs_btree_node_get_level(node);
+        if (level < minlevel || nilfs_btree_node_get_nchildren(node) <= 0)
                 return -ENOENT;
 
-        found = nilfs_btree_node_lookup(btree, node, key, &index);
+        found = nilfs_btree_node_lookup(node, key, &index);
         ptr = nilfs_btree_node_get_ptr(btree, node, index);
         path[level].bp_bh = NULL;
         path[level].bp_index = index;
@@ -510,14 +478,13 @@ static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
                 ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
                 if (ret < 0)
                         return ret;
-                node = nilfs_btree_get_nonroot_node(btree, path, level);
-                BUG_ON(level != nilfs_btree_node_get_level(btree, node));
+                node = nilfs_btree_get_nonroot_node(path, level);
+                BUG_ON(level != nilfs_btree_node_get_level(node));
                 if (!found)
-                        found = nilfs_btree_node_lookup(btree, node, key,
-                                                        &index);
+                        found = nilfs_btree_node_lookup(node, key, &index);
                 else
                         index = 0;
-                if (index < nilfs_btree_node_nchildren_max(btree, node))
+                if (index < nilfs_btree_node_nchildren_max(node, btree))
                         ptr = nilfs_btree_node_get_ptr(btree, node, index);
                 else {
                         WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
@@ -544,10 +511,10 @@ static int nilfs_btree_do_lookup_last(const struct nilfs_btree *btree,
         int index, level, ret;
 
         node = nilfs_btree_get_root(btree);
-        index = nilfs_btree_node_get_nchildren(btree, node) - 1;
+        index = nilfs_btree_node_get_nchildren(node) - 1;
         if (index < 0)
                 return -ENOENT;
-        level = nilfs_btree_node_get_level(btree, node);
+        level = nilfs_btree_node_get_level(node);
         ptr = nilfs_btree_node_get_ptr(btree, node, index);
         path[level].bp_bh = NULL;
         path[level].bp_index = index;
@@ -556,15 +523,15 @@ static int nilfs_btree_do_lookup_last(const struct nilfs_btree *btree,
                 ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
                 if (ret < 0)
                         return ret;
-                node = nilfs_btree_get_nonroot_node(btree, path, level);
-                BUG_ON(level != nilfs_btree_node_get_level(btree, node));
-                index = nilfs_btree_node_get_nchildren(btree, node) - 1;
+                node = nilfs_btree_get_nonroot_node(path, level);
+                BUG_ON(level != nilfs_btree_node_get_level(node));
+                index = nilfs_btree_node_get_nchildren(node) - 1;
                 ptr = nilfs_btree_node_get_ptr(btree, node, index);
                 path[level].bp_index = index;
         }
 
         if (keyp != NULL)
-                *keyp = nilfs_btree_node_get_key(btree, node, index);
+                *keyp = nilfs_btree_node_get_key(node, index);
         if (ptrp != NULL)
                 *ptrp = ptr;
 
@@ -580,18 +547,18 @@ static int nilfs_btree_lookup(const struct nilfs_bmap *bmap,
         int ret;
 
         btree = (struct nilfs_btree *)bmap;
-        path = nilfs_btree_alloc_path(btree);
+        path = nilfs_btree_alloc_path();
         if (path == NULL)
                 return -ENOMEM;
-        nilfs_btree_init_path(btree, path);
+        nilfs_btree_init_path(path);
 
         ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level);
 
         if (ptrp != NULL)
                 *ptrp = ptr;
 
-        nilfs_btree_clear_path(btree, path);
-        nilfs_btree_free_path(btree, path);
+        nilfs_btree_clear_path(path);
+        nilfs_btree_free_path(path);
 
         return ret;
 }
@@ -608,10 +575,10 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
         int level = NILFS_BTREE_LEVEL_NODE_MIN;
         int ret, cnt, index, maxlevel;
 
-        path = nilfs_btree_alloc_path(btree);
+        path = nilfs_btree_alloc_path();
         if (path == NULL)
                 return -ENOMEM;
-        nilfs_btree_init_path(btree, path);
+        nilfs_btree_init_path(path);
         ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level);
         if (ret < 0)
                 goto out;
@@ -631,8 +598,8 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
         node = nilfs_btree_get_node(btree, path, level);
         index = path[level].bp_index + 1;
         for (;;) {
-                while (index < nilfs_btree_node_get_nchildren(btree, node)) {
-                        if (nilfs_btree_node_get_key(btree, node, index) !=
+                while (index < nilfs_btree_node_get_nchildren(node)) {
+                        if (nilfs_btree_node_get_key(node, index) !=
                             key + cnt)
                                 goto end;
                         ptr2 = nilfs_btree_node_get_ptr(btree, node, index);
@@ -653,8 +620,8 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
                 /* look-up right sibling node */
                 node = nilfs_btree_get_node(btree, path, level + 1);
                 index = path[level + 1].bp_index + 1;
-                if (index >= nilfs_btree_node_get_nchildren(btree, node) ||
-                    nilfs_btree_node_get_key(btree, node, index) != key + cnt)
+                if (index >= nilfs_btree_node_get_nchildren(node) ||
+                    nilfs_btree_node_get_key(node, index) != key + cnt)
                         break;
                 ptr2 = nilfs_btree_node_get_ptr(btree, node, index);
                 path[level + 1].bp_index = index;
@@ -664,7 +631,7 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
                 ret = nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh);
                 if (ret < 0)
                         goto out;
-                node = nilfs_btree_get_nonroot_node(btree, path, level);
+                node = nilfs_btree_get_nonroot_node(path, level);
                 index = 0;
                 path[level].bp_index = index;
         }
@@ -672,8 +639,8 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
         *ptrp = ptr;
         ret = cnt;
  out:
-        nilfs_btree_clear_path(btree, path);
-        nilfs_btree_free_path(btree, path);
+        nilfs_btree_clear_path(path);
+        nilfs_btree_free_path(path);
         return ret;
 }
 
@@ -685,9 +652,7 @@ static void nilfs_btree_promote_key(struct nilfs_btree *btree,
                 do {
                         lock_buffer(path[level].bp_bh);
                         nilfs_btree_node_set_key(
-                                btree,
-                                nilfs_btree_get_nonroot_node(
-                                        btree, path, level),
+                                nilfs_btree_get_nonroot_node(path, level),
                                 path[level].bp_index, key);
                         if (!buffer_dirty(path[level].bp_bh))
                                 nilfs_btnode_mark_dirty(path[level].bp_bh);
@@ -698,8 +663,7 @@ static void nilfs_btree_promote_key(struct nilfs_btree *btree,
 
         /* root */
         if (level == nilfs_btree_height(btree) - 1) {
-                nilfs_btree_node_set_key(btree,
-                                         nilfs_btree_get_root(btree),
+                nilfs_btree_node_set_key(nilfs_btree_get_root(btree),
                                          path[level].bp_index, key);
         }
 }
@@ -712,7 +676,7 @@ static void nilfs_btree_do_insert(struct nilfs_btree *btree,
 
         if (level < nilfs_btree_height(btree) - 1) {
                 lock_buffer(path[level].bp_bh);
-                node = nilfs_btree_get_nonroot_node(btree, path, level);
+                node = nilfs_btree_get_nonroot_node(path, level);
                 nilfs_btree_node_insert(btree, node, *keyp, *ptrp,
                                         path[level].bp_index);
                 if (!buffer_dirty(path[level].bp_bh))
@@ -721,8 +685,8 @@ static void nilfs_btree_do_insert(struct nilfs_btree *btree,
 
                 if (path[level].bp_index == 0)
                         nilfs_btree_promote_key(btree, path, level + 1,
-                                                nilfs_btree_node_get_key(
-                                                        btree, node, 0));
+                                                nilfs_btree_node_get_key(node,
+                                                                         0));
         } else {
                 node = nilfs_btree_get_root(btree);
                 nilfs_btree_node_insert(btree, node, *keyp, *ptrp,
@@ -740,10 +704,10 @@ static void nilfs_btree_carry_left(struct nilfs_btree *btree,
         lock_buffer(path[level].bp_bh);
         lock_buffer(path[level].bp_sib_bh);
 
-        node = nilfs_btree_get_nonroot_node(btree, path, level);
-        left = nilfs_btree_get_sib_node(btree, path, level);
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
-        lnchildren = nilfs_btree_node_get_nchildren(btree, left);
+        node = nilfs_btree_get_nonroot_node(path, level);
+        left = nilfs_btree_get_sib_node(path, level);
+        nchildren = nilfs_btree_node_get_nchildren(node);
+        lnchildren = nilfs_btree_node_get_nchildren(left);
         move = 0;
 
         n = (nchildren + lnchildren + 1) / 2 - lnchildren;
@@ -764,7 +728,7 @@ static void nilfs_btree_carry_left(struct nilfs_btree *btree,
         unlock_buffer(path[level].bp_sib_bh);
 
         nilfs_btree_promote_key(btree, path, level + 1,
-                                nilfs_btree_node_get_key(btree, node, 0));
+                                nilfs_btree_node_get_key(node, 0));
 
         if (move) {
                 brelse(path[level].bp_bh);
@@ -791,10 +755,10 @@ static void nilfs_btree_carry_right(struct nilfs_btree *btree,
         lock_buffer(path[level].bp_bh);
         lock_buffer(path[level].bp_sib_bh);
 
-        node = nilfs_btree_get_nonroot_node(btree, path, level);
-        right = nilfs_btree_get_sib_node(btree, path, level);
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
-        rnchildren = nilfs_btree_node_get_nchildren(btree, right);
+        node = nilfs_btree_get_nonroot_node(path, level);
+        right = nilfs_btree_get_sib_node(path, level);
+        nchildren = nilfs_btree_node_get_nchildren(node);
+        rnchildren = nilfs_btree_node_get_nchildren(right);
         move = 0;
 
         n = (nchildren + rnchildren + 1) / 2 - rnchildren;
@@ -816,15 +780,14 @@ static void nilfs_btree_carry_right(struct nilfs_btree *btree,
 
         path[level + 1].bp_index++;
         nilfs_btree_promote_key(btree, path, level + 1,
-                                nilfs_btree_node_get_key(btree, right, 0));
+                                nilfs_btree_node_get_key(right, 0));
         path[level + 1].bp_index--;
 
         if (move) {
                 brelse(path[level].bp_bh);
                 path[level].bp_bh = path[level].bp_sib_bh;
                 path[level].bp_sib_bh = NULL;
-                path[level].bp_index -=
-                        nilfs_btree_node_get_nchildren(btree, node);
+                path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
                 path[level + 1].bp_index++;
         } else {
                 brelse(path[level].bp_sib_bh);
@@ -846,9 +809,9 @@ static void nilfs_btree_split(struct nilfs_btree *btree,
         lock_buffer(path[level].bp_bh);
         lock_buffer(path[level].bp_sib_bh);
 
-        node = nilfs_btree_get_nonroot_node(btree, path, level);
-        right = nilfs_btree_get_sib_node(btree, path, level);
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
+        node = nilfs_btree_get_nonroot_node(path, level);
+        right = nilfs_btree_get_sib_node(path, level);
+        nchildren = nilfs_btree_node_get_nchildren(node);
         move = 0;
 
         n = (nchildren + 1) / 2;
@@ -867,16 +830,15 @@ static void nilfs_btree_split(struct nilfs_btree *btree,
         unlock_buffer(path[level].bp_bh);
         unlock_buffer(path[level].bp_sib_bh);
 
-        newkey = nilfs_btree_node_get_key(btree, right, 0);
+        newkey = nilfs_btree_node_get_key(right, 0);
         newptr = path[level].bp_newreq.bpr_ptr;
 
         if (move) {
-                path[level].bp_index -=
-                        nilfs_btree_node_get_nchildren(btree, node);
+                path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
                 nilfs_btree_node_insert(btree, right, *keyp, *ptrp,
                                         path[level].bp_index);
 
-                *keyp = nilfs_btree_node_get_key(btree, right, 0);
+                *keyp = nilfs_btree_node_get_key(right, 0);
                 *ptrp = path[level].bp_newreq.bpr_ptr;
 
                 brelse(path[level].bp_bh);
@@ -885,7 +847,7 @@ static void nilfs_btree_split(struct nilfs_btree *btree,
         } else {
                 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
 
-                *keyp = nilfs_btree_node_get_key(btree, right, 0);
+                *keyp = nilfs_btree_node_get_key(right, 0);
                 *ptrp = path[level].bp_newreq.bpr_ptr;
 
                 brelse(path[level].bp_sib_bh);
@@ -905,12 +867,12 @@ static void nilfs_btree_grow(struct nilfs_btree *btree,
         lock_buffer(path[level].bp_sib_bh);
 
         root = nilfs_btree_get_root(btree);
-        child = nilfs_btree_get_sib_node(btree, path, level);
+        child = nilfs_btree_get_sib_node(path, level);
 
-        n = nilfs_btree_node_get_nchildren(btree, root);
+        n = nilfs_btree_node_get_nchildren(root);
 
         nilfs_btree_node_move_right(btree, root, child, n);
-        nilfs_btree_node_set_level(btree, root, level + 1);
+        nilfs_btree_node_set_level(root, level + 1);
 
         if (!buffer_dirty(path[level].bp_sib_bh))
                 nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
@@ -922,7 +884,7 @@ static void nilfs_btree_grow(struct nilfs_btree *btree,
 
         nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
 
-        *keyp = nilfs_btree_node_get_key(btree, child, 0);
+        *keyp = nilfs_btree_node_get_key(child, 0);
         *ptrp = path[level].bp_newreq.bpr_ptr;
 }
 
@@ -1007,9 +969,9 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
         for (level = NILFS_BTREE_LEVEL_NODE_MIN;
              level < nilfs_btree_height(btree) - 1;
              level++) {
-                node = nilfs_btree_get_nonroot_node(btree, path, level);
-                if (nilfs_btree_node_get_nchildren(btree, node) <
-                    nilfs_btree_node_nchildren_max(btree, node)) {
+                node = nilfs_btree_get_nonroot_node(path, level);
+                if (nilfs_btree_node_get_nchildren(node) <
+                    nilfs_btree_node_nchildren_max(node, btree)) {
                         path[level].bp_op = nilfs_btree_do_insert;
                         stats->bs_nblocks++;
                         goto out;
@@ -1026,8 +988,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
                         if (ret < 0)
                                 goto err_out_child_node;
                         sib = (struct nilfs_btree_node *)bh->b_data;
-                        if (nilfs_btree_node_get_nchildren(btree, sib) <
-                            nilfs_btree_node_nchildren_max(btree, sib)) {
+                        if (nilfs_btree_node_get_nchildren(sib) <
+                            nilfs_btree_node_nchildren_max(sib, btree)) {
                                 path[level].bp_sib_bh = bh;
                                 path[level].bp_op = nilfs_btree_carry_left;
                                 stats->bs_nblocks++;
@@ -1038,15 +1000,15 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 
                 /* right sibling */
                 if (pindex <
-                    nilfs_btree_node_get_nchildren(btree, parent) - 1) {
+                    nilfs_btree_node_get_nchildren(parent) - 1) {
                         sibptr = nilfs_btree_node_get_ptr(btree, parent,
                                                           pindex + 1);
                         ret = nilfs_btree_get_block(btree, sibptr, &bh);
                         if (ret < 0)
                                 goto err_out_child_node;
                         sib = (struct nilfs_btree_node *)bh->b_data;
-                        if (nilfs_btree_node_get_nchildren(btree, sib) <
-                            nilfs_btree_node_nchildren_max(btree, sib)) {
+                        if (nilfs_btree_node_get_nchildren(sib) <
+                            nilfs_btree_node_nchildren_max(sib, btree)) {
                                 path[level].bp_sib_bh = bh;
                                 path[level].bp_op = nilfs_btree_carry_right;
                                 stats->bs_nblocks++;
@@ -1081,8 +1043,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 
         /* root */
         node = nilfs_btree_get_root(btree);
-        if (nilfs_btree_node_get_nchildren(btree, node) <
-            nilfs_btree_node_nchildren_max(btree, node)) {
+        if (nilfs_btree_node_get_nchildren(node) <
+            nilfs_btree_node_nchildren_max(node, btree)) {
                 path[level].bp_op = nilfs_btree_do_insert;
                 stats->bs_nblocks++;
                 goto out;
@@ -1164,10 +1126,10 @@ static int nilfs_btree_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
         int level, ret;
 
         btree = (struct nilfs_btree *)bmap;
-        path = nilfs_btree_alloc_path(btree);
+        path = nilfs_btree_alloc_path();
         if (path == NULL)
                 return -ENOMEM;
-        nilfs_btree_init_path(btree, path);
+        nilfs_btree_init_path(path);
 
         ret = nilfs_btree_do_lookup(btree, path, key, NULL,
                                     NILFS_BTREE_LEVEL_NODE_MIN);
@@ -1184,8 +1146,8 @@ static int nilfs_btree_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
         nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
 
  out:
-        nilfs_btree_clear_path(btree, path);
-        nilfs_btree_free_path(btree, path);
+        nilfs_btree_clear_path(path);
+        nilfs_btree_free_path(path);
         return ret;
 }
 
@@ -1197,7 +1159,7 @@ static void nilfs_btree_do_delete(struct nilfs_btree *btree,
 
         if (level < nilfs_btree_height(btree) - 1) {
                 lock_buffer(path[level].bp_bh);
-                node = nilfs_btree_get_nonroot_node(btree, path, level);
+                node = nilfs_btree_get_nonroot_node(path, level);
                 nilfs_btree_node_delete(btree, node, keyp, ptrp,
                                         path[level].bp_index);
                 if (!buffer_dirty(path[level].bp_bh))
@@ -1205,7 +1167,7 @@ static void nilfs_btree_do_delete(struct nilfs_btree *btree,
                 unlock_buffer(path[level].bp_bh);
                 if (path[level].bp_index == 0)
                         nilfs_btree_promote_key(btree, path, level + 1,
-                                nilfs_btree_node_get_key(btree, node, 0));
+                                nilfs_btree_node_get_key(node, 0));
         } else {
                 node = nilfs_btree_get_root(btree);
                 nilfs_btree_node_delete(btree, node, keyp, ptrp,
@@ -1225,10 +1187,10 @@ static void nilfs_btree_borrow_left(struct nilfs_btree *btree,
         lock_buffer(path[level].bp_bh);
         lock_buffer(path[level].bp_sib_bh);
 
-        node = nilfs_btree_get_nonroot_node(btree, path, level);
-        left = nilfs_btree_get_sib_node(btree, path, level);
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
-        lnchildren = nilfs_btree_node_get_nchildren(btree, left);
+        node = nilfs_btree_get_nonroot_node(path, level);
+        left = nilfs_btree_get_sib_node(path, level);
+        nchildren = nilfs_btree_node_get_nchildren(node);
+        lnchildren = nilfs_btree_node_get_nchildren(left);
 
         n = (nchildren + lnchildren) / 2 - nchildren;
 
@@ -1243,7 +1205,7 @@ static void nilfs_btree_borrow_left(struct nilfs_btree *btree,
         unlock_buffer(path[level].bp_sib_bh);
 
         nilfs_btree_promote_key(btree, path, level + 1,
-                                nilfs_btree_node_get_key(btree, node, 0));
+                                nilfs_btree_node_get_key(node, 0));
 
         brelse(path[level].bp_sib_bh);
         path[level].bp_sib_bh = NULL;
@@ -1262,10 +1224,10 @@ static void nilfs_btree_borrow_right(struct nilfs_btree *btree,
         lock_buffer(path[level].bp_bh);
         lock_buffer(path[level].bp_sib_bh);
 
-        node = nilfs_btree_get_nonroot_node(btree, path, level);
-        right = nilfs_btree_get_sib_node(btree, path, level);
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
-        rnchildren = nilfs_btree_node_get_nchildren(btree, right);
+        node = nilfs_btree_get_nonroot_node(path, level);
+        right = nilfs_btree_get_sib_node(path, level);
+        nchildren = nilfs_btree_node_get_nchildren(node);
+        rnchildren = nilfs_btree_node_get_nchildren(right);
 
         n = (nchildren + rnchildren) / 2 - nchildren;
 
@@ -1281,7 +1243,7 @@ static void nilfs_btree_borrow_right(struct nilfs_btree *btree,
 
         path[level + 1].bp_index++;
         nilfs_btree_promote_key(btree, path, level + 1,
-                                nilfs_btree_node_get_key(btree, right, 0));
+                                nilfs_btree_node_get_key(right, 0));
         path[level + 1].bp_index--;
 
         brelse(path[level].bp_sib_bh);
@@ -1300,10 +1262,10 @@ static void nilfs_btree_concat_left(struct nilfs_btree *btree,
         lock_buffer(path[level].bp_bh);
         lock_buffer(path[level].bp_sib_bh);
 
-        node = nilfs_btree_get_nonroot_node(btree, path, level);
-        left = nilfs_btree_get_sib_node(btree, path, level);
+        node = nilfs_btree_get_nonroot_node(path, level);
+        left = nilfs_btree_get_sib_node(path, level);
 
-        n = nilfs_btree_node_get_nchildren(btree, node);
+        n = nilfs_btree_node_get_nchildren(node);
 
         nilfs_btree_node_move_left(btree, left, node, n);
 
@@ -1316,7 +1278,7 @@ static void nilfs_btree_concat_left(struct nilfs_btree *btree,
         nilfs_btnode_delete(path[level].bp_bh);
         path[level].bp_bh = path[level].bp_sib_bh;
         path[level].bp_sib_bh = NULL;
-        path[level].bp_index += nilfs_btree_node_get_nchildren(btree, left);
+        path[level].bp_index += nilfs_btree_node_get_nchildren(left);
 }
 
 static void nilfs_btree_concat_right(struct nilfs_btree *btree,
@@ -1331,10 +1293,10 @@ static void nilfs_btree_concat_right(struct nilfs_btree *btree,
         lock_buffer(path[level].bp_bh);
         lock_buffer(path[level].bp_sib_bh);
 
-        node = nilfs_btree_get_nonroot_node(btree, path, level);
-        right = nilfs_btree_get_sib_node(btree, path, level);
+        node = nilfs_btree_get_nonroot_node(path, level);
+        right = nilfs_btree_get_sib_node(path, level);
 
-        n = nilfs_btree_node_get_nchildren(btree, right);
+        n = nilfs_btree_node_get_nchildren(right);
 
         nilfs_btree_node_move_left(btree, node, right, n);
 
@@ -1360,11 +1322,11 @@ static void nilfs_btree_shrink(struct nilfs_btree *btree,
 
         lock_buffer(path[level].bp_bh);
         root = nilfs_btree_get_root(btree);
-        child = nilfs_btree_get_nonroot_node(btree, path, level);
+        child = nilfs_btree_get_nonroot_node(path, level);
 
         nilfs_btree_node_delete(btree, root, NULL, NULL, 0);
-        nilfs_btree_node_set_level(btree, root, level);
-        n = nilfs_btree_node_get_nchildren(btree, child);
+        nilfs_btree_node_set_level(root, level);
+        n = nilfs_btree_node_get_nchildren(child);
         nilfs_btree_node_move_left(btree, root, child, n);
         unlock_buffer(path[level].bp_bh);
 
@@ -1388,7 +1350,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
         for (level = NILFS_BTREE_LEVEL_NODE_MIN;
              level < nilfs_btree_height(btree) - 1;
              level++) {
-                node = nilfs_btree_get_nonroot_node(btree, path, level);
+                node = nilfs_btree_get_nonroot_node(path, level);
                 path[level].bp_oldreq.bpr_ptr =
                         nilfs_btree_node_get_ptr(btree, node,
                                                  path[level].bp_index);
@@ -1397,8 +1359,8 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
                 if (ret < 0)
                         goto err_out_child_node;
 
-                if (nilfs_btree_node_get_nchildren(btree, node) >
-                    nilfs_btree_node_nchildren_min(btree, node)) {
+                if (nilfs_btree_node_get_nchildren(node) >
+                    nilfs_btree_node_nchildren_min(node, btree)) {
                         path[level].bp_op = nilfs_btree_do_delete;
                         stats->bs_nblocks++;
                         goto out;
@@ -1415,8 +1377,8 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
                         if (ret < 0)
                                 goto err_out_curr_node;
                         sib = (struct nilfs_btree_node *)bh->b_data;
-                        if (nilfs_btree_node_get_nchildren(btree, sib) >
-                            nilfs_btree_node_nchildren_min(btree, sib)) {
+                        if (nilfs_btree_node_get_nchildren(sib) >
+                            nilfs_btree_node_nchildren_min(sib, btree)) {
                                 path[level].bp_sib_bh = bh;
                                 path[level].bp_op = nilfs_btree_borrow_left;
                                 stats->bs_nblocks++;
@@ -1428,7 +1390,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
                                 /* continue; */
                         }
                 } else if (pindex <
-                           nilfs_btree_node_get_nchildren(btree, parent) - 1) {
+                           nilfs_btree_node_get_nchildren(parent) - 1) {
                         /* right sibling */
                         sibptr = nilfs_btree_node_get_ptr(btree, parent,
                                                           pindex + 1);
@@ -1436,8 +1398,8 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
                         if (ret < 0)
                                 goto err_out_curr_node;
                         sib = (struct nilfs_btree_node *)bh->b_data;
-                        if (nilfs_btree_node_get_nchildren(btree, sib) >
-                            nilfs_btree_node_nchildren_min(btree, sib)) {
+                        if (nilfs_btree_node_get_nchildren(sib) >
+                            nilfs_btree_node_nchildren_min(sib, btree)) {
                                 path[level].bp_sib_bh = bh;
                                 path[level].bp_op = nilfs_btree_borrow_right;
                                 stats->bs_nblocks++;
@@ -1452,7 +1414,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
                         /* no siblings */
                         /* the only child of the root node */
                         WARN_ON(level != nilfs_btree_height(btree) - 2);
-                        if (nilfs_btree_node_get_nchildren(btree, node) - 1 <=
+                        if (nilfs_btree_node_get_nchildren(node) - 1 <=
                             NILFS_BTREE_ROOT_NCHILDREN_MAX) {
                                 path[level].bp_op = nilfs_btree_shrink;
                                 stats->bs_nblocks += 2;
@@ -1523,10 +1485,10 @@ static int nilfs_btree_delete(struct nilfs_bmap *bmap, __u64 key)
         int level, ret;
 
         btree = (struct nilfs_btree *)bmap;
-        path = nilfs_btree_alloc_path(btree);
+        path = nilfs_btree_alloc_path();
         if (path == NULL)
                 return -ENOMEM;
-        nilfs_btree_init_path(btree, path);
+        nilfs_btree_init_path(path);
         ret = nilfs_btree_do_lookup(btree, path, key, NULL,
                                     NILFS_BTREE_LEVEL_NODE_MIN);
         if (ret < 0)
@@ -1539,8 +1501,8 @@ static int nilfs_btree_delete(struct nilfs_bmap *bmap, __u64 key)
         nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
 
 out:
-        nilfs_btree_clear_path(btree, path);
-        nilfs_btree_free_path(btree, path);
+        nilfs_btree_clear_path(path);
+        nilfs_btree_free_path(path);
         return ret;
 }
 
@@ -1551,15 +1513,15 @@ static int nilfs_btree_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
         int ret;
 
         btree = (struct nilfs_btree *)bmap;
-        path = nilfs_btree_alloc_path(btree);
+        path = nilfs_btree_alloc_path();
         if (path == NULL)
                 return -ENOMEM;
-        nilfs_btree_init_path(btree, path);
+        nilfs_btree_init_path(path);
 
         ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
 
-        nilfs_btree_clear_path(btree, path);
-        nilfs_btree_free_path(btree, path);
+        nilfs_btree_clear_path(path);
+        nilfs_btree_free_path(path);
 
         return ret;
 }
@@ -1581,7 +1543,7 @@ static int nilfs_btree_check_delete(struct nilfs_bmap *bmap, __u64 key)
                 node = root;
                 break;
         case 3:
-                nchildren = nilfs_btree_node_get_nchildren(btree, root);
+                nchildren = nilfs_btree_node_get_nchildren(root);
                 if (nchildren > 1)
                         return 0;
                 ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
@@ -1594,10 +1556,10 @@ static int nilfs_btree_check_delete(struct nilfs_bmap *bmap, __u64 key)
                 return 0;
         }
 
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
-        maxkey = nilfs_btree_node_get_key(btree, node, nchildren - 1);
+        nchildren = nilfs_btree_node_get_nchildren(node);
+        maxkey = nilfs_btree_node_get_key(node, nchildren - 1);
         nextmaxkey = (nchildren > 1) ?
-                nilfs_btree_node_get_key(btree, node, nchildren - 2) : 0;
+                nilfs_btree_node_get_key(node, nchildren - 2) : 0;
         if (bh != NULL)
                 brelse(bh);
 
@@ -1623,7 +1585,7 @@ static int nilfs_btree_gather_data(struct nilfs_bmap *bmap,
                 node = root;
                 break;
         case 3:
-                nchildren = nilfs_btree_node_get_nchildren(btree, root);
+                nchildren = nilfs_btree_node_get_nchildren(root);
                 WARN_ON(nchildren > 1);
                 ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
                 ret = nilfs_btree_get_block(btree, ptr, &bh);
@@ -1636,11 +1598,11 @@ static int nilfs_btree_gather_data(struct nilfs_bmap *bmap,
                 return -EINVAL;
         }
 
-        nchildren = nilfs_btree_node_get_nchildren(btree, node);
+        nchildren = nilfs_btree_node_get_nchildren(node);
         if (nchildren < nitems)
                 nitems = nchildren;
-        dkeys = nilfs_btree_node_dkeys(btree, node);
-        dptrs = nilfs_btree_node_dptrs(btree, node);
+        dkeys = nilfs_btree_node_dkeys(node);
+        dptrs = nilfs_btree_node_dptrs(node, btree);
         for (i = 0; i < nitems; i++) {
                 keys[i] = nilfs_bmap_dkey_to_key(dkeys[i]);
                 ptrs[i] = nilfs_bmap_dptr_to_ptr(dptrs[i]);
@@ -1986,15 +1948,15 @@ static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
         WARN_ON(!buffer_dirty(bh));
 
         btree = (struct nilfs_btree *)bmap;
-        path = nilfs_btree_alloc_path(btree);
+        path = nilfs_btree_alloc_path();
         if (path == NULL)
                 return -ENOMEM;
-        nilfs_btree_init_path(btree, path);
+        nilfs_btree_init_path(path);
 
         if (buffer_nilfs_node(bh)) {
                 node = (struct nilfs_btree_node *)bh->b_data;
-                key = nilfs_btree_node_get_key(btree, node, 0);
-                level = nilfs_btree_node_get_level(btree, node);
+                key = nilfs_btree_node_get_key(node, 0);
+                level = nilfs_btree_node_get_level(node);
         } else {
                 key = nilfs_bmap_data_get_key(bmap, bh);
                 level = NILFS_BTREE_LEVEL_DATA;
@@ -2013,8 +1975,8 @@ static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
                 nilfs_btree_propagate_p(btree, path, level, bh);
 
  out:
-        nilfs_btree_clear_path(btree, path);
-        nilfs_btree_free_path(btree, path);
+        nilfs_btree_clear_path(path);
+        nilfs_btree_free_path(path);
 
         return ret;
 }
@@ -2037,12 +1999,12 @@ static void nilfs_btree_add_dirty_buffer(struct nilfs_btree *btree,
 
         get_bh(bh);
         node = (struct nilfs_btree_node *)bh->b_data;
-        key = nilfs_btree_node_get_key(btree, node, 0);
-        level = nilfs_btree_node_get_level(btree, node);
+        key = nilfs_btree_node_get_key(node, 0);
+        level = nilfs_btree_node_get_level(node);
         list_for_each(head, &lists[level]) {
                 cbh = list_entry(head, struct buffer_head, b_assoc_buffers);
                 cnode = (struct nilfs_btree_node *)cbh->b_data;
-                ckey = nilfs_btree_node_get_key(btree, cnode, 0);
+                ckey = nilfs_btree_node_get_key(cnode, 0);
                 if (key < ckey)
                         break;
         }
@@ -2120,8 +2082,7 @@ static int nilfs_btree_assign_p(struct nilfs_btree *btree,
         nilfs_btree_node_set_ptr(btree, parent,
                                  path[level + 1].bp_index, blocknr);
 
-        key = nilfs_btree_node_get_key(btree, parent,
-                                       path[level + 1].bp_index);
+        key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
         /* on-disk format */
         binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
         binfo->bi_dat.bi_level = level;
@@ -2150,8 +2111,7 @@ static int nilfs_btree_assign_v(struct nilfs_btree *btree,
         if (unlikely(ret < 0))
                 return ret;
 
-        key = nilfs_btree_node_get_key(btree, parent,
-                                       path[level + 1].bp_index);
+        key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
         /* on-disk format */
         binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
         binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
@@ -2171,15 +2131,15 @@ static int nilfs_btree_assign(struct nilfs_bmap *bmap,
         int level, ret;
 
         btree = (struct nilfs_btree *)bmap;
-        path = nilfs_btree_alloc_path(btree);
+        path = nilfs_btree_alloc_path();
         if (path == NULL)
                 return -ENOMEM;
-        nilfs_btree_init_path(btree, path);
+        nilfs_btree_init_path(path);
 
         if (buffer_nilfs_node(*bh)) {
                 node = (struct nilfs_btree_node *)(*bh)->b_data;
-                key = nilfs_btree_node_get_key(btree, node, 0);
-                level = nilfs_btree_node_get_level(btree, node);
+                key = nilfs_btree_node_get_key(node, 0);
+                level = nilfs_btree_node_get_level(node);
         } else {
                 key = nilfs_bmap_data_get_key(bmap, *bh);
                 level = NILFS_BTREE_LEVEL_DATA;
@@ -2196,8 +2156,8 @@ static int nilfs_btree_assign(struct nilfs_bmap *bmap,
                 nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
 
  out:
-        nilfs_btree_clear_path(btree, path);
-        nilfs_btree_free_path(btree, path);
+        nilfs_btree_clear_path(path);
+        nilfs_btree_free_path(path);
 
         return ret;
 }
@@ -2219,7 +2179,7 @@ static int nilfs_btree_assign_gc(struct nilfs_bmap *bmap,
 
         if (buffer_nilfs_node(*bh)) {
                 node = (struct nilfs_btree_node *)(*bh)->b_data;
-                key = nilfs_btree_node_get_key(btree, node, 0);
+                key = nilfs_btree_node_get_key(node, 0);
         } else
                 key = nilfs_bmap_data_get_key(bmap, *bh);
 
@@ -2239,10 +2199,10 @@ static int nilfs_btree_mark(struct nilfs_bmap *bmap, __u64 key, int level)
         int ret;
 
         btree = (struct nilfs_btree *)bmap;
-        path = nilfs_btree_alloc_path(btree);
+        path = nilfs_btree_alloc_path();
         if (path == NULL)
                 return -ENOMEM;
-        nilfs_btree_init_path(btree, path);
+        nilfs_btree_init_path(path);
 
         ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1);
         if (ret < 0) {
@@ -2262,8 +2222,8 @@ static int nilfs_btree_mark(struct nilfs_bmap *bmap, __u64 key, int level)
                 nilfs_bmap_set_dirty(&btree->bt_bmap);
 
  out:
-        nilfs_btree_clear_path(btree, path);
-        nilfs_btree_free_path(btree, path);
+        nilfs_btree_clear_path(path);
+        nilfs_btree_free_path(path);
         return ret;
 }