- 根目录:
- fs
- nilfs2
- bmap.c
/*
* bmap.c - NILFS block mapping.
*
* Copyright (C) 2006-2008 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/fs.h>
#include <linux/string.h>
#include <linux/errno.h>
#include "nilfs.h"
#include "bmap.h"
#include "btree.h"
#include "direct.h"
#include "btnode.h"
#include "mdt.h"
#include "dat.h"
#include "alloc.h"
struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
{
struct the_nilfs *nilfs = bmap->b_inode->i_sb->s_fs_info;
return nilfs->ns_dat;
}
static int nilfs_bmap_convert_error(struct nilfs_bmap *bmap,
const char *fname, int err)
{
struct inode *inode = bmap->b_inode;
if (err == -EINVAL) {
nilfs_error(inode->i_sb, fname,
"broken bmap (inode number=%lu)\n", inode->i_ino);
err = -EIO;
}
return err;
}
/**
* nilfs_bmap_lookup_at_level - find a data block or node block
* @bmap: bmap
* @key: key
* @level: level
* @ptrp: place to store the value associated to @key
*
* Description: nilfs_bmap_lookup_at_level() finds a record whose key
* matches @key in the block at @level of the bmap.
*
* Return Value: On success, 0 is returned and the record associated with @key
* is stored in the place pointed by @ptrp. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOENT - A record associated with @key does not exist.
*/
int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
__u64 *ptrp)
{
sector_t blocknr;
int ret;
down_read(&bmap->b_sem);
ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
if (ret < 0) {
ret = nilfs_bmap_convert_error(bmap, __func__, ret);
goto out;
}
if (NILFS_BMAP_USE_VBN(bmap)) {
ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
&blocknr);
if (!ret)
*ptrp = blocknr;
}
out:
up_read(&bmap->b_sem);
return ret;
}
int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
unsigned maxblocks)
{
int ret;
down_read(&bmap->b_sem);
ret = bmap->b_ops->bop_lookup_contig(bmap, key, ptrp, maxblocks);
up_read(&bmap->b_sem);
return nilfs_bmap_convert_error(bmap, __func__, ret);
}
static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
{
__u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
__u64 ptrs[NILFS_BMAP_SMALL_HIGH + 1];
int ret, n;
if (bmap->b_ops->bop_check_insert != NULL) {
ret = bmap->b_ops->bop_check_insert(bmap, key);
if (ret > 0) {
n = bmap->b_ops->bop_gather_data(
bmap, keys, ptrs, NILFS_BMAP_SMALL_HIGH + 1);
if (n < 0)
return n;
ret = nilfs_btree_convert_and_insert(
bmap, key, ptr, keys, ptrs, n);
if (ret == 0)
bmap->b_u.u_flags |= NILFS_BMAP_LARGE;
return ret;
} else if (ret < 0)
return ret;
}
return bmap->b_ops->bop_insert(bmap, key, ptr);
}
/**
* nilfs_bmap_insert - insert a new key-record pair into a bmap
* @bmap: bmap
* @key: key
* @rec: record
*
* Description: nilfs_bmap_insert() inserts the new key-record pair specified
* by @key and @rec into @bmap.
*
* Return Value: On success, 0 is returned. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-EEXIST - A record associated with @key already exist.
*/
int nilfs_bmap_insert(struct nilfs_bmap *bmap,
unsigned long key,
unsigned long rec)
{
int ret;
down_write(&bmap->b_sem);
ret = nilfs_bmap_do_insert(bmap, key, rec);
up_write(&bmap->b_sem);
return nilfs_bmap_convert_error(bmap, __func__, ret);
}
static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
{
__u64 keys[NILFS_BMAP_LARGE_LOW + 1];
__u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
int ret, n;
if (bmap->b_ops->bop_check_delete != NULL) {
ret = bmap->b_ops->bop_check_delete(bmap, key);
if (ret > 0) {
n = bmap->b_ops->bop_gather_data(
bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
if (n < 0)
return n;
ret = nilfs_direct_delete_and_convert(
bmap, key, keys, ptrs, n);
if (ret == 0)
bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;
return ret;
} else if (ret < 0)
return ret;
}
return bmap->b_ops->bop_delete(bmap, key);
}
int nilfs_bmap_last_key(struct nilfs_bmap *bmap, unsigned long *key)
{
__u64 lastkey;
int ret;
down_read(&bmap->b_sem);
ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
up_read(&bmap->b_sem);
if (ret < 0)
ret = nilfs_bmap_convert_error(bmap, __func__, ret);
else
*key = lastkey;
return ret;
}
/**
* nilfs_bmap_delete - delete a key-record pair from a bmap
* @bmap: bmap
* @key: key
*
* Description: nilfs_bmap_delete() deletes the key-record pair specified by
* @key from @bmap.
*
* Return Value: On success, 0 is returned. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOENT - A record associated with @key does not exist.
*/
int nilfs_bmap_delete(struct nilfs_bmap *bmap, unsigned long key)
{
int ret;
down_write(&bmap->b_sem);
ret = nilfs_bmap_do_delete(bmap, key);
up_write(&bmap->b_sem);
return nilfs_bmap_convert_error(bmap, __func__, ret);
}
static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, unsigned long key)
{
__u64 lastkey;
int ret;
ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
if (ret < 0) {
if (ret == -ENOENT)
ret = 0;
return ret;
}
while (key <= lastkey) {
ret = nilfs_bmap_do_delete(bmap, lastkey);
if (ret < 0)
return ret;
ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
if (ret < 0) {
if (ret == -ENOENT)
ret = 0;
return ret;
}
}
return 0;
}
/**
* nilfs_bmap_truncate - truncate a bmap to a specified key
* @bmap: bmap
* @key: key
*
* Description: nilfs_bmap_truncate() removes key-record pairs whose keys are
* greater than or equal to @key from @bmap.
*
* Return Value: On success, 0 is returned. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_bmap_truncate(struct nilfs_bmap *bmap, unsigned long key)
{
int ret;
down_write(&bmap->b_sem);
ret = nilfs_bmap_do_truncate(bmap, key);
up_write(&bmap->b_sem);
return nilfs_bmap_convert_error(bmap, __func__, ret);
}
/**
* nilfs_bmap_clear - free resources a bmap holds
* @bmap: bmap
*
* Description: nilfs_bmap_clear() frees resources associated with @bmap.
*/
void nilfs_bmap_clear(struct nilfs_bmap *bmap)
{
down_write(&bmap->b_sem);
if (bmap->b_ops->bop_clear != NULL)
bmap->b_ops->bop_clear(bmap);
up_write(&bmap->b_sem);
}
/**
* nilfs_bmap_propagate - propagate dirty state
* @bmap: bmap
* @bh: buffer head
*
* Description: nilfs_bmap_propagate() marks the buffers that directly or
* indirectly refer to the block specified by @bh dirty.
*
* Return Value: On success, 0 is returned. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
{
int ret;
down_write(&bmap->b_sem);
ret = bmap->b_ops->bop_propagate(bmap, bh);
up_write(&bmap->b_sem);
return nilfs_bmap_convert_error(bmap, __func__, ret);
}
/**
* nilfs_bmap_lookup_dirty_buffers -
* @bmap: bmap
* @listp: pointer to buffer head list
*/
void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
struct list_head *listp)
{
if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
}
/**
* nilfs_bmap_assign - assign a new block number to a block
* @bmap: bmap
* @bhp: pointer to buffer head
* @blocknr: block number
* @binfo: block information
*
* Description: nilfs_bmap_assign() assigns the block number @blocknr to the
* buffer specified by @bh.
*
* Return Value: On success, 0 is returned and the buffer head of a newly
* create buffer and the block information associated with the buffer are
* stored in the place pointed by @bh and @binfo, respectively. On error, one
* of the following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_bmap_assign(struct nilfs_bmap *bmap,
struct buffer_head **bh,
unsigned long blocknr,
union nilfs_binfo *binfo)
{
int ret;
down_write(&bmap->b_sem);
ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
up_write(&bmap->b_sem);
return nilfs_bmap_convert_error(bmap, __func__, ret);
}
/**
* nilfs_bmap_mark - mark block dirty
* @bmap: bmap
* @key: key
* @level: level
*
* Description: nilfs_bmap_mark() marks the block specified by @key and @level
* as dirty.
*
* Return Value: On success, 0 is returned. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
{
int ret;
if (bmap->b_ops->bop_mark == NULL)
return 0;
down_write(&bmap->b_sem);
ret = bmap->b_ops->bop_mark(bmap, key, level);
up_write(&bmap->b_sem);
return nilfs_bmap_convert_error(bmap, __func__, ret);
}
/**
* nilfs_bmap_test_and_clear_dirty - test and clear a bmap dirty state
* @bmap: bmap
*
* Description: nilfs_test_and_clear() is the atomic operation to test and
* clear the dirty state of @bmap.
*
* Return Value: 1 is returned if @bmap is dirty, or 0 if clear.
*/
int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
{
int ret;
down_write(&bmap->b_sem);
ret = nilfs_bmap_dirty(bmap);
nilfs_bmap_clear_dirty(bmap);
up_write(&bmap->b_sem);
return ret;
}
/*
* Internal use only
*/
__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
const struct buffer_head *bh)
{
struct buffer_head *pbh;
__u64 key;
key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
bmap->b_inode->i_blkbits);
for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
key++;
return key;
}
__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
{
__s64 diff;
diff = key - bmap->b_last_allocated_key;
if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
(bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
(bmap->b_last_allocated_ptr + diff > 0))
return bmap->b_last_allocated_ptr + diff;
else
return NILFS_BMAP_INVALID_PTR;
}
#define NILFS_BMAP_GROUP_DIV 8
__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
{
struct inode *dat = nilfs_bmap_get_dat(bmap);
unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
unsigned long group = bmap->b_inode->i_ino / entries_per_group;
return group * entries_per_group +
(bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
(entries_per_group / NILFS_BMAP_GROUP_DIV);
}
static struct lock_class_key nilfs_bmap_dat_lock_key;
static struct lock_class_key nilfs_bmap_mdt_lock_key;
/**
* nilfs_bmap_read - read a bmap from an inode
* @bmap: bmap
* @raw_inode: on-disk inode
*
* Description: nilfs_bmap_read() initializes the bmap @bmap.
*
* Return Value: On success, 0 is returned. On error, the following negative
* error code is returned.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
{
if (raw_inode == NULL)
memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
else
memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);
init_rwsem(&bmap->b_sem);
bmap->b_state = 0;
bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
switch (bmap->b_inode->i_ino) {
case NILFS_DAT_INO:
bmap->b_ptr_type = NILFS_BMAP_PTR_P;
bmap->b_last_allocated_key = 0;
bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
break;
case NILFS_CPFILE_INO:
case NILFS_SUFILE_INO:
bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
bmap->b_last_allocated_key = 0;
bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
break;
case NILFS_IFILE_INO:
lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
/* Fall through */
default:
bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
bmap->b_last_allocated_key = 0;
bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
break;
}
return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
}
/**
* nilfs_bmap_write - write back a bmap to an inode
* @bmap: bmap
* @raw_inode: on-disk inode
*
* Description: nilfs_bmap_write() stores @bmap in @raw_inode.
*/
void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
{
down_write(&bmap->b_sem);
memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
NILFS_INODE_BMAP_SIZE * sizeof(__le64));
if (bmap->b_inode->i_ino == NILFS_DAT_INO)
bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
up_write(&bmap->b_sem);
}
void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
{
memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
init_rwsem(&bmap->b_sem);
bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
bmap->b_ptr_type = NILFS_BMAP_PTR_U;
bmap->b_last_allocated_key = 0;
bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
bmap->b_state = 0;
nilfs_btree_init_gc(bmap);
}
void nilfs_bmap_save(const struct nilfs_bmap *bmap,
struct nilfs_bmap_store *store)
{
memcpy(store->data, bmap->b_u.u_data, sizeof(store->data));
store->last_allocated_key = bmap->b_last_allocated_key;
store->last_allocated_ptr = bmap->b_last_allocated_ptr;
store->state = bmap->b_state;
}
void nilfs_bmap_restore(struct nilfs_bmap *bmap,
const struct nilfs_bmap_store *store)
{
memcpy(bmap->b_u.u_data, store->data, sizeof(store->data));
bmap->b_last_allocated_key = store->last_allocated_key;
bmap->b_last_allocated_ptr = store->last_allocated_ptr;
bmap->b_state = store->state;
}