linux/fs/nilfs2/bmap.c
Ryusuke Konishi e3154e9748 nilfs2: get rid of nilfs_sb_info structure
This directly uses sb->s_fs_info to keep a nilfs filesystem object and
fully removes the intermediate nilfs_sb_info structure.  With this
change, the hierarchy of on-memory structures of nilfs will be
simplified as follows:

Before:
  super_block
       -> nilfs_sb_info
             -> the_nilfs
                   -> cptree --+-> nilfs_root (current file system)
                               +-> nilfs_root (snapshot A)
                               +-> nilfs_root (snapshot B)
                               :
             -> nilfs_sc_info (log writer structure)
After:
  super_block
       -> the_nilfs
             -> cptree --+-> nilfs_root (current file system)
                         +-> nilfs_root (snapshot A)
                         +-> nilfs_root (snapshot B)
                         :
             -> nilfs_sc_info (log writer structure)

The reason why we didn't design so from the beginning is because the
initial shape also differed from the above.  The early hierachy was
composed of "per-mount-point" super_block -> nilfs_sb_info pairs and a
shared nilfs object.  On the kernel 2.6.37, it was changed to the
current shape in order to unify super block instances into one per
device, and this cleanup became applicable as the result.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:54:26 +09:00

565 lines
14 KiB
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)
{
return NILFS_I_NILFS(bmap->b_inode)->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;
}