android_kernel_xiaomi_sm8350/fs/nilfs2/btree.c
Ryusuke Konishi 7cde31d7d6 nilfs2: remove nilfs_btree_operations from btree mapping
will remove indirect function calls using nilfs_btree_operations
table.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-06-10 23:41:11 +09:00

2236 lines
59 KiB
C

/*
* btree.c - NILFS B-tree.
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Koji Sato <koji@osrg.net>.
*/
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/pagevec.h>
#include "nilfs.h"
#include "page.h"
#include "btnode.h"
#include "btree.h"
#include "alloc.h"
/**
* struct nilfs_btree_path - A path on which B-tree operations are executed
* @bp_bh: buffer head of node block
* @bp_sib_bh: buffer head of sibling node block
* @bp_index: index of child node
* @bp_oldreq: ptr end request for old ptr
* @bp_newreq: ptr alloc request for new ptr
* @bp_op: rebalance operation
*/
struct nilfs_btree_path {
struct buffer_head *bp_bh;
struct buffer_head *bp_sib_bh;
int bp_index;
union nilfs_bmap_ptr_req bp_oldreq;
union nilfs_bmap_ptr_req bp_newreq;
struct nilfs_btnode_chkey_ctxt bp_ctxt;
void (*bp_op)(struct nilfs_btree *, struct nilfs_btree_path *,
int, __u64 *, __u64 *);
};
/*
* B-tree path operations
*/
static struct kmem_cache *nilfs_btree_path_cache;
int __init nilfs_btree_path_cache_init(void)
{
nilfs_btree_path_cache =
kmem_cache_create("nilfs2_btree_path_cache",
sizeof(struct nilfs_btree_path) *
NILFS_BTREE_LEVEL_MAX, 0, 0, NULL);
return (nilfs_btree_path_cache != NULL) ? 0 : -ENOMEM;
}
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)
{
return (struct nilfs_btree_path *)
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)
{
kmem_cache_free(nilfs_btree_path_cache, path);
}
static void nilfs_btree_init_path(const struct nilfs_btree *btree,
struct nilfs_btree_path *path)
{
int level;
for (level = NILFS_BTREE_LEVEL_DATA;
level < NILFS_BTREE_LEVEL_MAX;
level++) {
path[level].bp_bh = NULL;
path[level].bp_sib_bh = NULL;
path[level].bp_index = 0;
path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
path[level].bp_op = NULL;
}
}
static void nilfs_btree_clear_path(const struct nilfs_btree *btree,
struct nilfs_btree_path *path)
{
int level;
for (level = NILFS_BTREE_LEVEL_DATA;
level < NILFS_BTREE_LEVEL_MAX;
level++) {
if (path[level].bp_bh != NULL) {
brelse(path[level].bp_bh);
path[level].bp_bh = NULL;
}
/* sib_bh is released or deleted by prepare or commit
* operations. */
path[level].bp_sib_bh = NULL;
path[level].bp_index = 0;
path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
path[level].bp_op = NULL;
}
}
/*
* B-tree node operations
*/
static int nilfs_btree_get_block(const struct nilfs_btree *btree, __u64 ptr,
struct buffer_head **bhp)
{
struct address_space *btnc =
&NILFS_BMAP_I((struct nilfs_bmap *)btree)->i_btnode_cache;
return nilfs_btnode_get(btnc, ptr, 0, bhp, 0);
}
static int nilfs_btree_get_new_block(const struct nilfs_btree *btree,
__u64 ptr, struct buffer_head **bhp)
{
struct address_space *btnc =
&NILFS_BMAP_I((struct nilfs_bmap *)btree)->i_btnode_cache;
int ret;
ret = nilfs_btnode_get(btnc, ptr, 0, bhp, 1);
if (!ret)
set_buffer_nilfs_volatile(*bhp);
return ret;
}
static inline int
nilfs_btree_node_get_flags(const struct nilfs_btree *btree,
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)
{
node->bn_flags = flags;
}
static inline int nilfs_btree_node_root(const struct nilfs_btree *btree,
const struct nilfs_btree_node *node)
{
return nilfs_btree_node_get_flags(btree, node) & NILFS_BTREE_NODE_ROOT;
}
static inline int
nilfs_btree_node_get_level(const struct nilfs_btree *btree,
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)
{
node->bn_level = level;
}
static inline int
nilfs_btree_node_get_nchildren(const struct nilfs_btree *btree,
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)
{
node->bn_nchildren = cpu_to_le16(nchildren);
}
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)
{
return nilfs_btree_node_root(btree, 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)
{
return nilfs_btree_node_root(btree, 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)
{
return (__le64 *)((char *)(node + 1) +
(nilfs_btree_node_root(btree, 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)
{
return (__le64 *)(nilfs_btree_node_dkeys(btree, node) +
nilfs_btree_node_nchildren_max(btree, node));
}
static inline __u64
nilfs_btree_node_get_key(const struct nilfs_btree *btree,
const struct nilfs_btree_node *node, int index)
{
return nilfs_bmap_dkey_to_key(*(nilfs_btree_node_dkeys(btree, 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_dkeys(btree, 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)
{
return nilfs_bmap_dptr_to_ptr(*(nilfs_btree_node_dptrs(btree, node) +
index));
}
static inline void
nilfs_btree_node_set_ptr(struct nilfs_btree *btree,
struct nilfs_btree_node *node,
int index,
__u64 ptr)
{
*(nilfs_btree_node_dptrs(btree, node) + index) =
nilfs_bmap_ptr_to_dptr(ptr);
}
static void nilfs_btree_node_init(struct nilfs_btree *btree,
struct nilfs_btree_node *node,
int flags, int level, int nchildren,
const __u64 *keys, const __u64 *ptrs)
{
__le64 *dkeys;
__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);
dkeys = nilfs_btree_node_dkeys(btree, node);
dptrs = nilfs_btree_node_dptrs(btree, node);
for (i = 0; i < nchildren; i++) {
dkeys[i] = nilfs_bmap_key_to_dkey(keys[i]);
dptrs[i] = nilfs_bmap_ptr_to_dptr(ptrs[i]);
}
}
/* Assume the buffer heads corresponding to left and right are locked. */
static void nilfs_btree_node_move_left(struct nilfs_btree *btree,
struct nilfs_btree_node *left,
struct nilfs_btree_node *right,
int n)
{
__le64 *ldkeys, *rdkeys;
__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);
rdkeys = nilfs_btree_node_dkeys(btree, right);
rdptrs = nilfs_btree_node_dptrs(btree, right);
rnchildren = nilfs_btree_node_get_nchildren(btree, right);
memcpy(ldkeys + lnchildren, rdkeys, n * sizeof(*rdkeys));
memcpy(ldptrs + lnchildren, rdptrs, n * sizeof(*rdptrs));
memmove(rdkeys, rdkeys + n, (rnchildren - n) * sizeof(*rdkeys));
memmove(rdptrs, rdptrs + n, (rnchildren - n) * sizeof(*rdptrs));
lnchildren += n;
rnchildren -= n;
nilfs_btree_node_set_nchildren(btree, left, lnchildren);
nilfs_btree_node_set_nchildren(btree, right, rnchildren);
}
/* Assume that the buffer heads corresponding to left and right are locked. */
static void nilfs_btree_node_move_right(struct nilfs_btree *btree,
struct nilfs_btree_node *left,
struct nilfs_btree_node *right,
int n)
{
__le64 *ldkeys, *rdkeys;
__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);
rdkeys = nilfs_btree_node_dkeys(btree, right);
rdptrs = nilfs_btree_node_dptrs(btree, right);
rnchildren = nilfs_btree_node_get_nchildren(btree, right);
memmove(rdkeys + n, rdkeys, rnchildren * sizeof(*rdkeys));
memmove(rdptrs + n, rdptrs, rnchildren * sizeof(*rdptrs));
memcpy(rdkeys, ldkeys + lnchildren - n, n * sizeof(*rdkeys));
memcpy(rdptrs, ldptrs + lnchildren - n, n * sizeof(*rdptrs));
lnchildren -= n;
rnchildren += n;
nilfs_btree_node_set_nchildren(btree, left, lnchildren);
nilfs_btree_node_set_nchildren(btree, right, rnchildren);
}
/* Assume that the buffer head corresponding to node is locked. */
static void nilfs_btree_node_insert(struct nilfs_btree *btree,
struct nilfs_btree_node *node,
__u64 key, __u64 ptr, int index)
{
__le64 *dkeys;
__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);
if (index < nchildren) {
memmove(dkeys + index + 1, dkeys + index,
(nchildren - index) * sizeof(*dkeys));
memmove(dptrs + index + 1, dptrs + index,
(nchildren - index) * sizeof(*dptrs));
}
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);
}
/* Assume that the buffer head corresponding to node is locked. */
static void nilfs_btree_node_delete(struct nilfs_btree *btree,
struct nilfs_btree_node *node,
__u64 *keyp, __u64 *ptrp, int index)
{
__u64 key;
__u64 ptr;
__le64 *dkeys;
__le64 *dptrs;
int nchildren;
dkeys = nilfs_btree_node_dkeys(btree, node);
dptrs = nilfs_btree_node_dptrs(btree, node);
key = nilfs_bmap_dkey_to_key(dkeys[index]);
ptr = nilfs_bmap_dptr_to_ptr(dptrs[index]);
nchildren = nilfs_btree_node_get_nchildren(btree, node);
if (keyp != NULL)
*keyp = key;
if (ptrp != NULL)
*ptrp = ptr;
if (index < nchildren - 1) {
memmove(dkeys + index, dkeys + index + 1,
(nchildren - index - 1) * sizeof(*dkeys));
memmove(dptrs + index, dptrs + index + 1,
(nchildren - index - 1) * sizeof(*dptrs));
}
nchildren--;
nilfs_btree_node_set_nchildren(btree, node, nchildren);
}
static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
const struct nilfs_btree_node *node,
__u64 key, int *indexp)
{
__u64 nkey;
int index, low, high, s;
/* binary search */
low = 0;
high = nilfs_btree_node_get_nchildren(btree, node) - 1;
index = 0;
s = 0;
while (low <= high) {
index = (low + high) / 2;
nkey = nilfs_btree_node_get_key(btree, node, index);
if (nkey == key) {
s = 0;
goto out;
} else if (nkey < key) {
low = index + 1;
s = -1;
} else {
high = index - 1;
s = 1;
}
}
/* adjust index */
if (nilfs_btree_node_get_level(btree, node) >
NILFS_BTREE_LEVEL_NODE_MIN) {
if ((s > 0) && (index > 0))
index--;
} else if (s < 0)
index++;
out:
*indexp = index;
return s == 0;
}
static inline struct nilfs_btree_node *
nilfs_btree_get_root(const struct nilfs_btree *btree)
{
return (struct nilfs_btree_node *)btree->bt_bmap.b_u.u_data;
}
static inline struct nilfs_btree_node *
nilfs_btree_get_nonroot_node(const struct nilfs_btree *btree,
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)
{
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;
}
static inline struct nilfs_btree_node *
nilfs_btree_get_node(const struct nilfs_btree *btree,
const struct nilfs_btree_path *path,
int level)
{
return (level == nilfs_btree_height(btree) - 1) ?
nilfs_btree_get_root(btree) :
nilfs_btree_get_nonroot_node(btree, path, level);
}
static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
struct nilfs_btree_path *path,
__u64 key, __u64 *ptrp, int minlevel)
{
struct nilfs_btree_node *node;
__u64 ptr;
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))
return -ENOENT;
found = nilfs_btree_node_lookup(btree, node, key, &index);
ptr = nilfs_btree_node_get_ptr(btree, node, index);
path[level].bp_bh = NULL;
path[level].bp_index = index;
for (level--; level >= minlevel; level--) {
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));
if (!found)
found = nilfs_btree_node_lookup(btree, node, key,
&index);
else
index = 0;
if (index < nilfs_btree_node_nchildren_max(btree, node))
ptr = nilfs_btree_node_get_ptr(btree, node, index);
else {
WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
/* insert */
ptr = NILFS_BMAP_INVALID_PTR;
}
path[level].bp_index = index;
}
if (!found)
return -ENOENT;
if (ptrp != NULL)
*ptrp = ptr;
return 0;
}
static int nilfs_btree_do_lookup_last(const struct nilfs_btree *btree,
struct nilfs_btree_path *path,
__u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node;
__u64 ptr;
int index, level, ret;
node = nilfs_btree_get_root(btree);
index = nilfs_btree_node_get_nchildren(btree, node) - 1;
if (index < 0)
return -ENOENT;
level = nilfs_btree_node_get_level(btree, node);
ptr = nilfs_btree_node_get_ptr(btree, node, index);
path[level].bp_bh = NULL;
path[level].bp_index = index;
for (level--; level > 0; level--) {
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;
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);
if (ptrp != NULL)
*ptrp = ptr;
return 0;
}
static int nilfs_btree_lookup(const struct nilfs_bmap *bmap,
__u64 key, int level, __u64 *ptrp)
{
struct nilfs_btree *btree;
struct nilfs_btree_path *path;
__u64 ptr;
int ret;
btree = (struct nilfs_btree *)bmap;
path = nilfs_btree_alloc_path(btree);
if (path == NULL)
return -ENOMEM;
nilfs_btree_init_path(btree, 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);
return ret;
}
static void nilfs_btree_promote_key(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 key)
{
if (level < nilfs_btree_height(btree) - 1) {
do {
lock_buffer(path[level].bp_bh);
nilfs_btree_node_set_key(
btree,
nilfs_btree_get_nonroot_node(
btree, path, level),
path[level].bp_index, key);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
unlock_buffer(path[level].bp_bh);
} while ((path[level].bp_index == 0) &&
(++level < nilfs_btree_height(btree) - 1));
}
/* root */
if (level == nilfs_btree_height(btree) - 1) {
nilfs_btree_node_set_key(btree,
nilfs_btree_get_root(btree),
path[level].bp_index, key);
}
}
static void nilfs_btree_do_insert(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node;
if (level < nilfs_btree_height(btree) - 1) {
lock_buffer(path[level].bp_bh);
node = nilfs_btree_get_nonroot_node(btree, path, level);
nilfs_btree_node_insert(btree, node, *keyp, *ptrp,
path[level].bp_index);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
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));
} else {
node = nilfs_btree_get_root(btree);
nilfs_btree_node_insert(btree, node, *keyp, *ptrp,
path[level].bp_index);
}
}
static void nilfs_btree_carry_left(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node, *left;
int nchildren, lnchildren, n, move;
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);
move = 0;
n = (nchildren + lnchildren + 1) / 2 - lnchildren;
if (n > path[level].bp_index) {
/* move insert point */
n--;
move = 1;
}
nilfs_btree_node_move_left(btree, left, node, n);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
if (!buffer_dirty(path[level].bp_sib_bh))
nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
unlock_buffer(path[level].bp_bh);
unlock_buffer(path[level].bp_sib_bh);
nilfs_btree_promote_key(btree, path, level + 1,
nilfs_btree_node_get_key(btree, node, 0));
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 += lnchildren;
path[level + 1].bp_index--;
} else {
brelse(path[level].bp_sib_bh);
path[level].bp_sib_bh = NULL;
path[level].bp_index -= n;
}
nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
}
static void nilfs_btree_carry_right(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node, *right;
int nchildren, rnchildren, n, move;
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);
move = 0;
n = (nchildren + rnchildren + 1) / 2 - rnchildren;
if (n > nchildren - path[level].bp_index) {
/* move insert point */
n--;
move = 1;
}
nilfs_btree_node_move_right(btree, node, right, n);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
if (!buffer_dirty(path[level].bp_sib_bh))
nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
unlock_buffer(path[level].bp_bh);
unlock_buffer(path[level].bp_sib_bh);
path[level + 1].bp_index++;
nilfs_btree_promote_key(btree, path, level + 1,
nilfs_btree_node_get_key(btree, 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 + 1].bp_index++;
} else {
brelse(path[level].bp_sib_bh);
path[level].bp_sib_bh = NULL;
}
nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
}
static void nilfs_btree_split(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node, *right;
__u64 newkey;
__u64 newptr;
int nchildren, n, move;
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);
move = 0;
n = (nchildren + 1) / 2;
if (n > nchildren - path[level].bp_index) {
n--;
move = 1;
}
nilfs_btree_node_move_right(btree, node, right, n);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
if (!buffer_dirty(path[level].bp_sib_bh))
nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
unlock_buffer(path[level].bp_bh);
unlock_buffer(path[level].bp_sib_bh);
newkey = nilfs_btree_node_get_key(btree, right, 0);
newptr = path[level].bp_newreq.bpr_ptr;
if (move) {
path[level].bp_index -=
nilfs_btree_node_get_nchildren(btree, node);
nilfs_btree_node_insert(btree, right, *keyp, *ptrp,
path[level].bp_index);
*keyp = nilfs_btree_node_get_key(btree, right, 0);
*ptrp = path[level].bp_newreq.bpr_ptr;
brelse(path[level].bp_bh);
path[level].bp_bh = path[level].bp_sib_bh;
path[level].bp_sib_bh = NULL;
} else {
nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
*keyp = nilfs_btree_node_get_key(btree, right, 0);
*ptrp = path[level].bp_newreq.bpr_ptr;
brelse(path[level].bp_sib_bh);
path[level].bp_sib_bh = NULL;
}
path[level + 1].bp_index++;
}
static void nilfs_btree_grow(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *root, *child;
int n;
lock_buffer(path[level].bp_sib_bh);
root = nilfs_btree_get_root(btree);
child = nilfs_btree_get_sib_node(btree, path, level);
n = nilfs_btree_node_get_nchildren(btree, root);
nilfs_btree_node_move_right(btree, root, child, n);
nilfs_btree_node_set_level(btree, root, level + 1);
if (!buffer_dirty(path[level].bp_sib_bh))
nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
unlock_buffer(path[level].bp_sib_bh);
path[level].bp_bh = path[level].bp_sib_bh;
path[level].bp_sib_bh = NULL;
nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
*keyp = nilfs_btree_node_get_key(btree, child, 0);
*ptrp = path[level].bp_newreq.bpr_ptr;
}
static __u64 nilfs_btree_find_near(const struct nilfs_btree *btree,
const struct nilfs_btree_path *path)
{
struct nilfs_btree_node *node;
int level;
if (path == NULL)
return NILFS_BMAP_INVALID_PTR;
/* left sibling */
level = NILFS_BTREE_LEVEL_NODE_MIN;
if (path[level].bp_index > 0) {
node = nilfs_btree_get_node(btree, path, level);
return nilfs_btree_node_get_ptr(btree, node,
path[level].bp_index - 1);
}
/* parent */
level = NILFS_BTREE_LEVEL_NODE_MIN + 1;
if (level <= nilfs_btree_height(btree) - 1) {
node = nilfs_btree_get_node(btree, path, level);
return nilfs_btree_node_get_ptr(btree, node,
path[level].bp_index);
}
return NILFS_BMAP_INVALID_PTR;
}
static __u64 nilfs_btree_find_target_v(const struct nilfs_btree *btree,
const struct nilfs_btree_path *path,
__u64 key)
{
__u64 ptr;
ptr = nilfs_bmap_find_target_seq(&btree->bt_bmap, key);
if (ptr != NILFS_BMAP_INVALID_PTR)
/* sequential access */
return ptr;
else {
ptr = nilfs_btree_find_near(btree, path);
if (ptr != NILFS_BMAP_INVALID_PTR)
/* near */
return ptr;
}
/* block group */
return nilfs_bmap_find_target_in_group(&btree->bt_bmap);
}
static void nilfs_btree_set_target_v(struct nilfs_btree *btree, __u64 key,
__u64 ptr)
{
btree->bt_bmap.b_last_allocated_key = key;
btree->bt_bmap.b_last_allocated_ptr = ptr;
}
static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int *levelp, __u64 key, __u64 ptr,
struct nilfs_bmap_stats *stats)
{
struct buffer_head *bh;
struct nilfs_btree_node *node, *parent, *sib;
__u64 sibptr;
int pindex, level, ret;
stats->bs_nblocks = 0;
level = NILFS_BTREE_LEVEL_DATA;
/* allocate a new ptr for data block */
if (NILFS_BMAP_USE_VBN(&btree->bt_bmap))
path[level].bp_newreq.bpr_ptr =
nilfs_btree_find_target_v(btree, path, key);
ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
&path[level].bp_newreq);
if (ret < 0)
goto err_out_data;
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)) {
path[level].bp_op = nilfs_btree_do_insert;
stats->bs_nblocks++;
goto out;
}
parent = nilfs_btree_get_node(btree, path, level + 1);
pindex = path[level + 1].bp_index;
/* left sibling */
if (pindex > 0) {
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)) {
path[level].bp_sib_bh = bh;
path[level].bp_op = nilfs_btree_carry_left;
stats->bs_nblocks++;
goto out;
} else
brelse(bh);
}
/* right sibling */
if (pindex <
nilfs_btree_node_get_nchildren(btree, 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)) {
path[level].bp_sib_bh = bh;
path[level].bp_op = nilfs_btree_carry_right;
stats->bs_nblocks++;
goto out;
} else
brelse(bh);
}
/* split */
path[level].bp_newreq.bpr_ptr =
path[level - 1].bp_newreq.bpr_ptr + 1;
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,
&bh);
if (ret < 0)
goto err_out_curr_node;
stats->bs_nblocks++;
lock_buffer(bh);
nilfs_btree_node_init(btree,
(struct nilfs_btree_node *)bh->b_data,
0, level, 0, NULL, NULL);
unlock_buffer(bh);
path[level].bp_sib_bh = bh;
path[level].bp_op = nilfs_btree_split;
}
/* root */
node = nilfs_btree_get_root(btree);
if (nilfs_btree_node_get_nchildren(btree, node) <
nilfs_btree_node_nchildren_max(btree, node)) {
path[level].bp_op = nilfs_btree_do_insert;
stats->bs_nblocks++;
goto out;
}
/* grow */
path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
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,
&bh);
if (ret < 0)
goto err_out_curr_node;
lock_buffer(bh);
nilfs_btree_node_init(btree, (struct nilfs_btree_node *)bh->b_data,
0, level, 0, NULL, NULL);
unlock_buffer(bh);
path[level].bp_sib_bh = bh;
path[level].bp_op = nilfs_btree_grow;
level++;
path[level].bp_op = nilfs_btree_do_insert;
/* a newly-created node block and a data block are added */
stats->bs_nblocks += 2;
/* success */
out:
*levelp = level;
return ret;
/* error */
err_out_curr_node:
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);
nilfs_bmap_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;
return ret;
}
static void nilfs_btree_commit_insert(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int maxlevel, __u64 key, __u64 ptr)
{
int level;
set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr;
if (NILFS_BMAP_USE_VBN(&btree->bt_bmap))
nilfs_btree_set_target_v(btree, key, ptr);
for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
nilfs_bmap_commit_alloc_ptr(&btree->bt_bmap,
&path[level - 1].bp_newreq);
path[level].bp_op(btree, path, level, &key, &ptr);
}
if (!nilfs_bmap_dirty(&btree->bt_bmap))
nilfs_bmap_set_dirty(&btree->bt_bmap);
}
static int nilfs_btree_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
{
struct nilfs_btree *btree;
struct nilfs_btree_path *path;
struct nilfs_bmap_stats stats;
int level, ret;
btree = (struct nilfs_btree *)bmap;
path = nilfs_btree_alloc_path(btree);
if (path == NULL)
return -ENOMEM;
nilfs_btree_init_path(btree, path);
ret = nilfs_btree_do_lookup(btree, path, key, NULL,
NILFS_BTREE_LEVEL_NODE_MIN);
if (ret != -ENOENT) {
if (ret == 0)
ret = -EEXIST;
goto out;
}
ret = nilfs_btree_prepare_insert(btree, path, &level, key, ptr, &stats);
if (ret < 0)
goto out;
nilfs_btree_commit_insert(btree, path, level, key, ptr);
nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
out:
nilfs_btree_clear_path(btree, path);
nilfs_btree_free_path(btree, path);
return ret;
}
static void nilfs_btree_do_delete(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node;
if (level < nilfs_btree_height(btree) - 1) {
lock_buffer(path[level].bp_bh);
node = nilfs_btree_get_nonroot_node(btree, path, level);
nilfs_btree_node_delete(btree, node, keyp, ptrp,
path[level].bp_index);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
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));
} else {
node = nilfs_btree_get_root(btree);
nilfs_btree_node_delete(btree, node, keyp, ptrp,
path[level].bp_index);
}
}
static void nilfs_btree_borrow_left(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node, *left;
int nchildren, lnchildren, n;
nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
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);
n = (nchildren + lnchildren) / 2 - nchildren;
nilfs_btree_node_move_right(btree, left, node, n);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
if (!buffer_dirty(path[level].bp_sib_bh))
nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
unlock_buffer(path[level].bp_bh);
unlock_buffer(path[level].bp_sib_bh);
nilfs_btree_promote_key(btree, path, level + 1,
nilfs_btree_node_get_key(btree, node, 0));
brelse(path[level].bp_sib_bh);
path[level].bp_sib_bh = NULL;
path[level].bp_index += n;
}
static void nilfs_btree_borrow_right(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node, *right;
int nchildren, rnchildren, n;
nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
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);
n = (nchildren + rnchildren) / 2 - nchildren;
nilfs_btree_node_move_left(btree, node, right, n);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
if (!buffer_dirty(path[level].bp_sib_bh))
nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
unlock_buffer(path[level].bp_bh);
unlock_buffer(path[level].bp_sib_bh);
path[level + 1].bp_index++;
nilfs_btree_promote_key(btree, path, level + 1,
nilfs_btree_node_get_key(btree, right, 0));
path[level + 1].bp_index--;
brelse(path[level].bp_sib_bh);
path[level].bp_sib_bh = NULL;
}
static void nilfs_btree_concat_left(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node, *left;
int n;
nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
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);
n = nilfs_btree_node_get_nchildren(btree, node);
nilfs_btree_node_move_left(btree, left, node, n);
if (!buffer_dirty(path[level].bp_sib_bh))
nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
unlock_buffer(path[level].bp_bh);
unlock_buffer(path[level].bp_sib_bh);
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);
}
static void nilfs_btree_concat_right(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *node, *right;
int n;
nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
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);
n = nilfs_btree_node_get_nchildren(btree, right);
nilfs_btree_node_move_left(btree, node, right, n);
if (!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
unlock_buffer(path[level].bp_bh);
unlock_buffer(path[level].bp_sib_bh);
nilfs_btnode_delete(path[level].bp_sib_bh);
path[level].bp_sib_bh = NULL;
path[level + 1].bp_index++;
}
static void nilfs_btree_shrink(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level, __u64 *keyp, __u64 *ptrp)
{
struct nilfs_btree_node *root, *child;
int n;
nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
lock_buffer(path[level].bp_bh);
root = nilfs_btree_get_root(btree);
child = nilfs_btree_get_nonroot_node(btree, 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_move_left(btree, root, child, n);
unlock_buffer(path[level].bp_bh);
nilfs_btnode_delete(path[level].bp_bh);
path[level].bp_bh = NULL;
}
static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int *levelp,
struct nilfs_bmap_stats *stats)
{
struct buffer_head *bh;
struct nilfs_btree_node *node, *parent, *sib;
__u64 sibptr;
int pindex, level, ret;
ret = 0;
stats->bs_nblocks = 0;
for (level = NILFS_BTREE_LEVEL_NODE_MIN;
level < nilfs_btree_height(btree) - 1;
level++) {
node = nilfs_btree_get_nonroot_node(btree, path, level);
path[level].bp_oldreq.bpr_ptr =
nilfs_btree_node_get_ptr(btree, node,
path[level].bp_index);
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)) {
path[level].bp_op = nilfs_btree_do_delete;
stats->bs_nblocks++;
goto out;
}
parent = nilfs_btree_get_node(btree, path, level + 1);
pindex = path[level + 1].bp_index;
if (pindex > 0) {
/* left sibling */
sibptr = nilfs_btree_node_get_ptr(btree, parent,
pindex - 1);
ret = nilfs_btree_get_block(btree, sibptr, &bh);
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)) {
path[level].bp_sib_bh = bh;
path[level].bp_op = nilfs_btree_borrow_left;
stats->bs_nblocks++;
goto out;
} else {
path[level].bp_sib_bh = bh;
path[level].bp_op = nilfs_btree_concat_left;
stats->bs_nblocks++;
/* continue; */
}
} else if (pindex <
nilfs_btree_node_get_nchildren(btree, parent) - 1) {
/* right sibling */
sibptr = nilfs_btree_node_get_ptr(btree, parent,
pindex + 1);
ret = nilfs_btree_get_block(btree, sibptr, &bh);
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)) {
path[level].bp_sib_bh = bh;
path[level].bp_op = nilfs_btree_borrow_right;
stats->bs_nblocks++;
goto out;
} else {
path[level].bp_sib_bh = bh;
path[level].bp_op = nilfs_btree_concat_right;
stats->bs_nblocks++;
/* continue; */
}
} else {
/* 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 <=
NILFS_BTREE_ROOT_NCHILDREN_MAX) {
path[level].bp_op = nilfs_btree_shrink;
stats->bs_nblocks += 2;
} else {
path[level].bp_op = nilfs_btree_do_delete;
stats->bs_nblocks++;
}
goto out;
}
}
node = nilfs_btree_get_root(btree);
path[level].bp_oldreq.bpr_ptr =
nilfs_btree_node_get_ptr(btree, node, path[level].bp_index);
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++;
/* success */
out:
*levelp = level;
return ret;
/* error */
err_out_curr_node:
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);
nilfs_bmap_abort_end_ptr(&btree->bt_bmap,
&path[level].bp_oldreq);
}
*levelp = level;
stats->bs_nblocks = 0;
return ret;
}
static void nilfs_btree_commit_delete(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int maxlevel)
{
int level;
for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
nilfs_bmap_commit_end_ptr(&btree->bt_bmap,
&path[level].bp_oldreq);
path[level].bp_op(btree, path, level, NULL, NULL);
}
if (!nilfs_bmap_dirty(&btree->bt_bmap))
nilfs_bmap_set_dirty(&btree->bt_bmap);
}
static int nilfs_btree_delete(struct nilfs_bmap *bmap, __u64 key)
{
struct nilfs_btree *btree;
struct nilfs_btree_path *path;
struct nilfs_bmap_stats stats;
int level, ret;
btree = (struct nilfs_btree *)bmap;
path = nilfs_btree_alloc_path(btree);
if (path == NULL)
return -ENOMEM;
nilfs_btree_init_path(btree, path);
ret = nilfs_btree_do_lookup(btree, path, key, NULL,
NILFS_BTREE_LEVEL_NODE_MIN);
if (ret < 0)
goto out;
ret = nilfs_btree_prepare_delete(btree, path, &level, &stats);
if (ret < 0)
goto out;
nilfs_btree_commit_delete(btree, path, level);
nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
out:
nilfs_btree_clear_path(btree, path);
nilfs_btree_free_path(btree, path);
return ret;
}
static int nilfs_btree_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
{
struct nilfs_btree *btree;
struct nilfs_btree_path *path;
int ret;
btree = (struct nilfs_btree *)bmap;
path = nilfs_btree_alloc_path(btree);
if (path == NULL)
return -ENOMEM;
nilfs_btree_init_path(btree, path);
ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
nilfs_btree_clear_path(btree, path);
nilfs_btree_free_path(btree, path);
return ret;
}
static int nilfs_btree_check_delete(struct nilfs_bmap *bmap, __u64 key)
{
struct buffer_head *bh;
struct nilfs_btree *btree;
struct nilfs_btree_node *root, *node;
__u64 maxkey, nextmaxkey;
__u64 ptr;
int nchildren, ret;
btree = (struct nilfs_btree *)bmap;
root = nilfs_btree_get_root(btree);
switch (nilfs_btree_height(btree)) {
case 2:
bh = NULL;
node = root;
break;
case 3:
nchildren = nilfs_btree_node_get_nchildren(btree, root);
if (nchildren > 1)
return 0;
ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
ret = nilfs_btree_get_block(btree, ptr, &bh);
if (ret < 0)
return ret;
node = (struct nilfs_btree_node *)bh->b_data;
break;
default:
return 0;
}
nchildren = nilfs_btree_node_get_nchildren(btree, node);
maxkey = nilfs_btree_node_get_key(btree, node, nchildren - 1);
nextmaxkey = (nchildren > 1) ?
nilfs_btree_node_get_key(btree, node, nchildren - 2) : 0;
if (bh != NULL)
brelse(bh);
return (maxkey == key) && (nextmaxkey < NILFS_BMAP_LARGE_LOW);
}
static int nilfs_btree_gather_data(struct nilfs_bmap *bmap,
__u64 *keys, __u64 *ptrs, int nitems)
{
struct buffer_head *bh;
struct nilfs_btree *btree;
struct nilfs_btree_node *node, *root;
__le64 *dkeys;
__le64 *dptrs;
__u64 ptr;
int nchildren, i, ret;
btree = (struct nilfs_btree *)bmap;
root = nilfs_btree_get_root(btree);
switch (nilfs_btree_height(btree)) {
case 2:
bh = NULL;
node = root;
break;
case 3:
nchildren = nilfs_btree_node_get_nchildren(btree, root);
WARN_ON(nchildren > 1);
ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
ret = nilfs_btree_get_block(btree, ptr, &bh);
if (ret < 0)
return ret;
node = (struct nilfs_btree_node *)bh->b_data;
break;
default:
node = NULL;
return -EINVAL;
}
nchildren = nilfs_btree_node_get_nchildren(btree, node);
if (nchildren < nitems)
nitems = nchildren;
dkeys = nilfs_btree_node_dkeys(btree, node);
dptrs = nilfs_btree_node_dptrs(btree, node);
for (i = 0; i < nitems; i++) {
keys[i] = nilfs_bmap_dkey_to_key(dkeys[i]);
ptrs[i] = nilfs_bmap_dptr_to_ptr(dptrs[i]);
}
if (bh != NULL)
brelse(bh);
return nitems;
}
static int
nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
union nilfs_bmap_ptr_req *dreq,
union nilfs_bmap_ptr_req *nreq,
struct buffer_head **bhp,
struct nilfs_bmap_stats *stats)
{
struct buffer_head *bh;
struct nilfs_btree *btree;
int ret;
btree = (struct nilfs_btree *)bmap;
stats->bs_nblocks = 0;
/* for data */
/* cannot find near ptr */
if (NILFS_BMAP_USE_VBN(bmap))
dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key);
ret = nilfs_bmap_prepare_alloc_ptr(bmap, dreq);
if (ret < 0)
return ret;
*bhp = NULL;
stats->bs_nblocks++;
if (nreq != NULL) {
nreq->bpr_ptr = dreq->bpr_ptr + 1;
ret = nilfs_bmap_prepare_alloc_ptr(bmap, nreq);
if (ret < 0)
goto err_out_dreq;
ret = nilfs_btree_get_new_block(btree, nreq->bpr_ptr, &bh);
if (ret < 0)
goto err_out_nreq;
*bhp = bh;
stats->bs_nblocks++;
}
/* success */
return 0;
/* error */
err_out_nreq:
nilfs_bmap_abort_alloc_ptr(bmap, nreq);
err_out_dreq:
nilfs_bmap_abort_alloc_ptr(bmap, dreq);
stats->bs_nblocks = 0;
return ret;
}
static void
nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *bmap,
__u64 key, __u64 ptr,
const __u64 *keys, const __u64 *ptrs,
int n,
union nilfs_bmap_ptr_req *dreq,
union nilfs_bmap_ptr_req *nreq,
struct buffer_head *bh)
{
struct nilfs_btree *btree;
struct nilfs_btree_node *node;
__u64 tmpptr;
/* free resources */
if (bmap->b_ops->bop_clear != NULL)
bmap->b_ops->bop_clear(bmap);
/* ptr must be a pointer to a buffer head. */
set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
/* convert and insert */
btree = (struct nilfs_btree *)bmap;
nilfs_btree_init(bmap);
if (nreq != NULL) {
nilfs_bmap_commit_alloc_ptr(bmap, dreq);
nilfs_bmap_commit_alloc_ptr(bmap, nreq);
/* create child node at level 1 */
lock_buffer(bh);
node = (struct nilfs_btree_node *)bh->b_data;
nilfs_btree_node_init(btree, node, 0, 1, n, keys, ptrs);
nilfs_btree_node_insert(btree, node,
key, dreq->bpr_ptr, n);
if (!buffer_dirty(bh))
nilfs_btnode_mark_dirty(bh);
if (!nilfs_bmap_dirty(bmap))
nilfs_bmap_set_dirty(bmap);
unlock_buffer(bh);
brelse(bh);
/* create root node at level 2 */
node = nilfs_btree_get_root(btree);
tmpptr = nreq->bpr_ptr;
nilfs_btree_node_init(btree, node, NILFS_BTREE_NODE_ROOT,
2, 1, &keys[0], &tmpptr);
} else {
nilfs_bmap_commit_alloc_ptr(bmap, dreq);
/* create root node at level 1 */
node = nilfs_btree_get_root(btree);
nilfs_btree_node_init(btree, node, NILFS_BTREE_NODE_ROOT,
1, n, keys, ptrs);
nilfs_btree_node_insert(btree, node,
key, dreq->bpr_ptr, n);
if (!nilfs_bmap_dirty(bmap))
nilfs_bmap_set_dirty(bmap);
}
if (NILFS_BMAP_USE_VBN(bmap))
nilfs_btree_set_target_v(btree, key, dreq->bpr_ptr);
}
/**
* nilfs_btree_convert_and_insert -
* @bmap:
* @key:
* @ptr:
* @keys:
* @ptrs:
* @n:
*/
int nilfs_btree_convert_and_insert(struct nilfs_bmap *bmap,
__u64 key, __u64 ptr,
const __u64 *keys, const __u64 *ptrs, int n)
{
struct buffer_head *bh;
union nilfs_bmap_ptr_req dreq, nreq, *di, *ni;
struct nilfs_bmap_stats stats;
int ret;
if (n + 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) {
di = &dreq;
ni = NULL;
} else if ((n + 1) <= NILFS_BTREE_NODE_NCHILDREN_MAX(
1 << bmap->b_inode->i_blkbits)) {
di = &dreq;
ni = &nreq;
} else {
di = NULL;
ni = NULL;
BUG();
}
ret = nilfs_btree_prepare_convert_and_insert(bmap, key, di, ni, &bh,
&stats);
if (ret < 0)
return ret;
nilfs_btree_commit_convert_and_insert(bmap, key, ptr, keys, ptrs, n,
di, ni, bh);
nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
return 0;
}
static int nilfs_btree_propagate_p(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level,
struct buffer_head *bh)
{
while ((++level < nilfs_btree_height(btree) - 1) &&
!buffer_dirty(path[level].bp_bh))
nilfs_btnode_mark_dirty(path[level].bp_bh);
return 0;
}
static int nilfs_btree_prepare_update_v(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level)
{
struct nilfs_btree_node *parent;
int ret;
parent = nilfs_btree_get_node(btree, path, level + 1);
path[level].bp_oldreq.bpr_ptr =
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_v(&btree->bt_bmap,
&path[level].bp_oldreq,
&path[level].bp_newreq);
if (ret < 0)
return ret;
if (buffer_nilfs_node(path[level].bp_bh)) {
path[level].bp_ctxt.oldkey = path[level].bp_oldreq.bpr_ptr;
path[level].bp_ctxt.newkey = path[level].bp_newreq.bpr_ptr;
path[level].bp_ctxt.bh = path[level].bp_bh;
ret = nilfs_btnode_prepare_change_key(
&NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
&path[level].bp_ctxt);
if (ret < 0) {
nilfs_bmap_abort_update_v(&btree->bt_bmap,
&path[level].bp_oldreq,
&path[level].bp_newreq);
return ret;
}
}
return 0;
}
static void nilfs_btree_commit_update_v(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level)
{
struct nilfs_btree_node *parent;
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(
&NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
&path[level].bp_ctxt);
path[level].bp_bh = path[level].bp_ctxt.bh;
}
set_buffer_nilfs_volatile(path[level].bp_bh);
parent = nilfs_btree_get_node(btree, path, level + 1);
nilfs_btree_node_set_ptr(btree, parent, path[level + 1].bp_index,
path[level].bp_newreq.bpr_ptr);
}
static void nilfs_btree_abort_update_v(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level)
{
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,
&path[level].bp_ctxt);
}
static int nilfs_btree_prepare_propagate_v(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int minlevel,
int *maxlevelp)
{
int level, ret;
level = minlevel;
if (!buffer_nilfs_volatile(path[level].bp_bh)) {
ret = nilfs_btree_prepare_update_v(btree, path, level);
if (ret < 0)
return ret;
}
while ((++level < nilfs_btree_height(btree) - 1) &&
!buffer_dirty(path[level].bp_bh)) {
WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
ret = nilfs_btree_prepare_update_v(btree, path, level);
if (ret < 0)
goto out;
}
/* success */
*maxlevelp = level - 1;
return 0;
/* error */
out:
while (--level > minlevel)
nilfs_btree_abort_update_v(btree, path, level);
if (!buffer_nilfs_volatile(path[level].bp_bh))
nilfs_btree_abort_update_v(btree, path, level);
return ret;
}
static void nilfs_btree_commit_propagate_v(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int minlevel,
int maxlevel,
struct buffer_head *bh)
{
int level;
if (!buffer_nilfs_volatile(path[minlevel].bp_bh))
nilfs_btree_commit_update_v(btree, path, minlevel);
for (level = minlevel + 1; level <= maxlevel; level++)
nilfs_btree_commit_update_v(btree, path, level);
}
static int nilfs_btree_propagate_v(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level,
struct buffer_head *bh)
{
int maxlevel, ret;
struct nilfs_btree_node *parent;
__u64 ptr;
get_bh(bh);
path[level].bp_bh = bh;
ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel);
if (ret < 0)
goto out;
if (buffer_nilfs_volatile(path[level].bp_bh)) {
parent = nilfs_btree_get_node(btree, path, level + 1);
ptr = nilfs_btree_node_get_ptr(btree, parent,
path[level + 1].bp_index);
ret = nilfs_bmap_mark_dirty(&btree->bt_bmap, ptr);
if (ret < 0)
goto out;
}
nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh);
out:
brelse(path[level].bp_bh);
path[level].bp_bh = NULL;
return ret;
}
static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
struct buffer_head *bh)
{
struct nilfs_btree *btree;
struct nilfs_btree_path *path;
struct nilfs_btree_node *node;
__u64 key;
int level, ret;
WARN_ON(!buffer_dirty(bh));
btree = (struct nilfs_btree *)bmap;
path = nilfs_btree_alloc_path(btree);
if (path == NULL)
return -ENOMEM;
nilfs_btree_init_path(btree, 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);
} else {
key = nilfs_bmap_data_get_key(bmap, bh);
level = NILFS_BTREE_LEVEL_DATA;
}
ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1);
if (ret < 0) {
if (unlikely(ret == -ENOENT))
printk(KERN_CRIT "%s: key = %llu, level == %d\n",
__func__, (unsigned long long)key, level);
goto out;
}
ret = NILFS_BMAP_USE_VBN(bmap) ?
nilfs_btree_propagate_v(btree, path, level, bh) :
nilfs_btree_propagate_p(btree, path, level, bh);
out:
nilfs_btree_clear_path(btree, path);
nilfs_btree_free_path(btree, path);
return ret;
}
static int nilfs_btree_propagate_gc(const struct nilfs_bmap *bmap,
struct buffer_head *bh)
{
return nilfs_bmap_mark_dirty(bmap, bh->b_blocknr);
}
static void nilfs_btree_add_dirty_buffer(struct nilfs_btree *btree,
struct list_head *lists,
struct buffer_head *bh)
{
struct list_head *head;
struct buffer_head *cbh;
struct nilfs_btree_node *node, *cnode;
__u64 key, ckey;
int level;
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);
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);
if (key < ckey)
break;
}
list_add_tail(&bh->b_assoc_buffers, head);
}
static void nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap *bmap,
struct list_head *listp)
{
struct nilfs_btree *btree = (struct nilfs_btree *)bmap;
struct address_space *btcache = &NILFS_BMAP_I(bmap)->i_btnode_cache;
struct list_head lists[NILFS_BTREE_LEVEL_MAX];
struct pagevec pvec;
struct buffer_head *bh, *head;
pgoff_t index = 0;
int level, i;
for (level = NILFS_BTREE_LEVEL_NODE_MIN;
level < NILFS_BTREE_LEVEL_MAX;
level++)
INIT_LIST_HEAD(&lists[level]);
pagevec_init(&pvec, 0);
while (pagevec_lookup_tag(&pvec, btcache, &index, PAGECACHE_TAG_DIRTY,
PAGEVEC_SIZE)) {
for (i = 0; i < pagevec_count(&pvec); i++) {
bh = head = page_buffers(pvec.pages[i]);
do {
if (buffer_dirty(bh))
nilfs_btree_add_dirty_buffer(btree,
lists, bh);
} while ((bh = bh->b_this_page) != head);
}
pagevec_release(&pvec);
cond_resched();
}
for (level = NILFS_BTREE_LEVEL_NODE_MIN;
level < NILFS_BTREE_LEVEL_MAX;
level++)
list_splice(&lists[level], listp->prev);
}
static int nilfs_btree_assign_p(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level,
struct buffer_head **bh,
sector_t blocknr,
union nilfs_binfo *binfo)
{
struct nilfs_btree_node *parent;
__u64 key;
__u64 ptr;
int ret;
parent = nilfs_btree_get_node(btree, path, level + 1);
ptr = nilfs_btree_node_get_ptr(btree, parent,
path[level + 1].bp_index);
if (buffer_nilfs_node(*bh)) {
path[level].bp_ctxt.oldkey = ptr;
path[level].bp_ctxt.newkey = blocknr;
path[level].bp_ctxt.bh = *bh;
ret = nilfs_btnode_prepare_change_key(
&NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
&path[level].bp_ctxt);
if (ret < 0)
return ret;
nilfs_btnode_commit_change_key(
&NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
&path[level].bp_ctxt);
*bh = path[level].bp_ctxt.bh;
}
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);
/* on-disk format */
binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
binfo->bi_dat.bi_level = level;
return 0;
}
static int nilfs_btree_assign_v(struct nilfs_btree *btree,
struct nilfs_btree_path *path,
int level,
struct buffer_head **bh,
sector_t blocknr,
union nilfs_binfo *binfo)
{
struct nilfs_btree_node *parent;
__u64 key;
__u64 ptr;
union nilfs_bmap_ptr_req req;
int ret;
parent = nilfs_btree_get_node(btree, path, level + 1);
ptr = nilfs_btree_node_get_ptr(btree, parent,
path[level + 1].bp_index);
req.bpr_ptr = ptr;
ret = nilfs_bmap_start_v(&btree->bt_bmap, &req, blocknr);
if (unlikely(ret < 0))
return ret;
key = nilfs_btree_node_get_key(btree, 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);
return 0;
}
static int nilfs_btree_assign(struct nilfs_bmap *bmap,
struct buffer_head **bh,
sector_t blocknr,
union nilfs_binfo *binfo)
{
struct nilfs_btree *btree;
struct nilfs_btree_path *path;
struct nilfs_btree_node *node;
__u64 key;
int level, ret;
btree = (struct nilfs_btree *)bmap;
path = nilfs_btree_alloc_path(btree);
if (path == NULL)
return -ENOMEM;
nilfs_btree_init_path(btree, 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);
} else {
key = nilfs_bmap_data_get_key(bmap, *bh);
level = NILFS_BTREE_LEVEL_DATA;
}
ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1);
if (ret < 0) {
WARN_ON(ret == -ENOENT);
goto out;
}
ret = NILFS_BMAP_USE_VBN(bmap) ?
nilfs_btree_assign_v(btree, path, level, bh, blocknr, binfo) :
nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
out:
nilfs_btree_clear_path(btree, path);
nilfs_btree_free_path(btree, path);
return ret;
}
static int nilfs_btree_assign_gc(struct nilfs_bmap *bmap,
struct buffer_head **bh,
sector_t blocknr,
union nilfs_binfo *binfo)
{
struct nilfs_btree *btree;
struct nilfs_btree_node *node;
__u64 key;
int ret;
btree = (struct nilfs_btree *)bmap;
ret = nilfs_bmap_move_v(bmap, (*bh)->b_blocknr, blocknr);
if (ret < 0)
return ret;
if (buffer_nilfs_node(*bh)) {
node = (struct nilfs_btree_node *)(*bh)->b_data;
key = nilfs_btree_node_get_key(btree, node, 0);
} else
key = nilfs_bmap_data_get_key(bmap, *bh);
/* on-disk format */
binfo->bi_v.bi_vblocknr = cpu_to_le64((*bh)->b_blocknr);
binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
return 0;
}
static int nilfs_btree_mark(struct nilfs_bmap *bmap, __u64 key, int level)
{
struct buffer_head *bh;
struct nilfs_btree *btree;
struct nilfs_btree_path *path;
__u64 ptr;
int ret;
btree = (struct nilfs_btree *)bmap;
path = nilfs_btree_alloc_path(btree);
if (path == NULL)
return -ENOMEM;
nilfs_btree_init_path(btree, path);
ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1);
if (ret < 0) {
WARN_ON(ret == -ENOENT);
goto out;
}
ret = nilfs_btree_get_block(btree, ptr, &bh);
if (ret < 0) {
WARN_ON(ret == -ENOENT);
goto out;
}
if (!buffer_dirty(bh))
nilfs_btnode_mark_dirty(bh);
brelse(bh);
if (!nilfs_bmap_dirty(&btree->bt_bmap))
nilfs_bmap_set_dirty(&btree->bt_bmap);
out:
nilfs_btree_clear_path(btree, path);
nilfs_btree_free_path(btree, path);
return ret;
}
static const struct nilfs_bmap_operations nilfs_btree_ops = {
.bop_lookup = nilfs_btree_lookup,
.bop_insert = nilfs_btree_insert,
.bop_delete = nilfs_btree_delete,
.bop_clear = NULL,
.bop_propagate = nilfs_btree_propagate,
.bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
.bop_assign = nilfs_btree_assign,
.bop_mark = nilfs_btree_mark,
.bop_last_key = nilfs_btree_last_key,
.bop_check_insert = NULL,
.bop_check_delete = nilfs_btree_check_delete,
.bop_gather_data = nilfs_btree_gather_data,
};
static const struct nilfs_bmap_operations nilfs_btree_ops_gc = {
.bop_lookup = NULL,
.bop_insert = NULL,
.bop_delete = NULL,
.bop_clear = NULL,
.bop_propagate = nilfs_btree_propagate_gc,
.bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
.bop_assign = nilfs_btree_assign_gc,
.bop_mark = NULL,
.bop_last_key = NULL,
.bop_check_insert = NULL,
.bop_check_delete = NULL,
.bop_gather_data = NULL,
};
int nilfs_btree_init(struct nilfs_bmap *bmap)
{
bmap->b_ops = &nilfs_btree_ops;
return 0;
}
void nilfs_btree_init_gc(struct nilfs_bmap *bmap)
{
bmap->b_ops = &nilfs_btree_ops_gc;
}