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nilfs2: persistent object allocator

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This adds common functions to allocate or deallocate entries with bitmaps
on a meta data file.  This feature is used by the DAT and ifile.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ryusuke Konishi 2009-04-06 19:01:29 -07:00 committed by Linus Torvalds
parent 5eb563f5f2
commit 5442680fd2
2 changed files with 576 additions and 0 deletions
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504
fs/nilfs2/alloc.c Normal file
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/*
* alloc.c - NILFS dat/inode allocator
*
* 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
*
* Original code was written by Koji Sato <koji@osrg.net>.
* Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
* Amagai Yoshiji <amagai@osrg.net>.
*/
#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/bitops.h>
#include "mdt.h"
#include "alloc.h"
static inline unsigned long
nilfs_palloc_groups_per_desc_block(const struct inode *inode)
{
return (1UL << inode->i_blkbits) /
sizeof(struct nilfs_palloc_group_desc);
}
static inline unsigned long
nilfs_palloc_groups_count(const struct inode *inode)
{
return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
}
int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size)
{
struct nilfs_mdt_info *mi = NILFS_MDT(inode);
mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
if (!mi->mi_bgl)
return -ENOMEM;
bgl_lock_init(mi->mi_bgl);
nilfs_mdt_set_entry_size(inode, entry_size, 0);
mi->mi_blocks_per_group =
DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
mi->mi_entries_per_block) + 1;
/* Number of blocks in a group including entry blocks and
a bitmap block */
mi->mi_blocks_per_desc_block =
nilfs_palloc_groups_per_desc_block(inode) *
mi->mi_blocks_per_group + 1;
/* Number of blocks per descriptor including the
descriptor block */
return 0;
}
static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
unsigned long *offset)
{
__u64 group = nr;
*offset = do_div(group, nilfs_palloc_entries_per_group(inode));
return group;
}
static unsigned long
nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
{
unsigned long desc_block =
group / nilfs_palloc_groups_per_desc_block(inode);
return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
}
static unsigned long
nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
{
unsigned long desc_offset =
group % nilfs_palloc_groups_per_desc_block(inode);
return nilfs_palloc_desc_blkoff(inode, group) + 1 +
desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
}
static unsigned long
nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group,
const struct nilfs_palloc_group_desc *desc)
{
unsigned long nfree;
spin_lock(nilfs_mdt_bgl_lock(inode, group));
nfree = le32_to_cpu(desc->pg_nfrees);
spin_unlock(nilfs_mdt_bgl_lock(inode, group));
return nfree;
}
static void
nilfs_palloc_group_desc_add_entries(struct inode *inode,
unsigned long group,
struct nilfs_palloc_group_desc *desc,
u32 n)
{
spin_lock(nilfs_mdt_bgl_lock(inode, group));
le32_add_cpu(&desc->pg_nfrees, n);
spin_unlock(nilfs_mdt_bgl_lock(inode, group));
}
static unsigned long
nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
{
unsigned long group, group_offset;
group = nilfs_palloc_group(inode, nr, &group_offset);
return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
group_offset / NILFS_MDT(inode)->mi_entries_per_block;
}
static void nilfs_palloc_desc_block_init(struct inode *inode,
struct buffer_head *bh, void *kaddr)
{
struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
__le32 nfrees;
nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
while (n-- > 0) {
desc->pg_nfrees = nfrees;
desc++;
}
}
static int nilfs_palloc_get_desc_block(struct inode *inode,
unsigned long group,
int create, struct buffer_head **bhp)
{
return nilfs_mdt_get_block(inode,
nilfs_palloc_desc_blkoff(inode, group),
create, nilfs_palloc_desc_block_init, bhp);
}
static int nilfs_palloc_get_bitmap_block(struct inode *inode,
unsigned long group,
int create, struct buffer_head **bhp)
{
return nilfs_mdt_get_block(inode,
nilfs_palloc_bitmap_blkoff(inode, group),
create, NULL, bhp);
}
int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
int create, struct buffer_head **bhp)
{
return nilfs_mdt_get_block(inode, nilfs_palloc_entry_blkoff(inode, nr),
create, NULL, bhp);
}
static struct nilfs_palloc_group_desc *
nilfs_palloc_block_get_group_desc(const struct inode *inode,
unsigned long group,
const struct buffer_head *bh, void *kaddr)
{
return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
group % nilfs_palloc_groups_per_desc_block(inode);
}
static unsigned char *
nilfs_palloc_block_get_bitmap(const struct inode *inode,
const struct buffer_head *bh, void *kaddr)
{
return (unsigned char *)(kaddr + bh_offset(bh));
}
void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
const struct buffer_head *bh, void *kaddr)
{
unsigned long entry_offset, group_offset;
nilfs_palloc_group(inode, nr, &group_offset);
entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
return kaddr + bh_offset(bh) +
entry_offset * NILFS_MDT(inode)->mi_entry_size;
}
static int nilfs_palloc_find_available_slot(struct inode *inode,
unsigned long group,
unsigned long target,
unsigned char *bitmap,
int bsize) /* size in bits */
{
int curr, pos, end, i;
if (target > 0) {
end = (target + BITS_PER_LONG - 1) & ~(BITS_PER_LONG - 1);
if (end > bsize)
end = bsize;
pos = nilfs_find_next_zero_bit(bitmap, end, target);
if (pos < end &&
!nilfs_set_bit_atomic(
nilfs_mdt_bgl_lock(inode, group), pos, bitmap))
return pos;
} else
end = 0;
for (i = 0, curr = end;
i < bsize;
i += BITS_PER_LONG, curr += BITS_PER_LONG) {
/* wrap around */
if (curr >= bsize)
curr = 0;
while (*((unsigned long *)bitmap + curr / BITS_PER_LONG)
!= ~0UL) {
end = curr + BITS_PER_LONG;
if (end > bsize)
end = bsize;
pos = nilfs_find_next_zero_bit(bitmap, end, curr);
if ((pos < end) &&
!nilfs_set_bit_atomic(
nilfs_mdt_bgl_lock(inode, group), pos,
bitmap))
return pos;
}
}
return -ENOSPC;
}
static unsigned long
nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
unsigned long curr, unsigned long max)
{
return min_t(unsigned long,
nilfs_palloc_groups_per_desc_block(inode) -
curr % nilfs_palloc_groups_per_desc_block(inode),
max - curr + 1);
}
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
void *desc_kaddr, *bitmap_kaddr;
unsigned long group, maxgroup, ngroups;
unsigned long group_offset, maxgroup_offset;
unsigned long n, entries_per_group, groups_per_desc_block;
unsigned long i, j;
int pos, ret;
ngroups = nilfs_palloc_groups_count(inode);
maxgroup = ngroups - 1;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
entries_per_group = nilfs_palloc_entries_per_group(inode);
groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode);
for (i = 0; i < ngroups; i += n) {
if (group >= ngroups) {
/* wrap around */
group = 0;
maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
&maxgroup_offset) - 1;
}
ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
if (ret < 0)
return ret;
desc_kaddr = kmap(desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(
inode, group, desc_bh, desc_kaddr);
n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
maxgroup);
for (j = 0; j < n; j++, desc++, group++) {
if (nilfs_palloc_group_desc_nfrees(inode, group, desc)
> 0) {
ret = nilfs_palloc_get_bitmap_block(
inode, group, 1, &bitmap_bh);
if (ret < 0)
goto out_desc;
bitmap_kaddr = kmap(bitmap_bh->b_page);
bitmap = nilfs_palloc_block_get_bitmap(
inode, bitmap_bh, bitmap_kaddr);
pos = nilfs_palloc_find_available_slot(
inode, group, group_offset, bitmap,
entries_per_group);
if (pos >= 0) {
/* found a free entry */
nilfs_palloc_group_desc_add_entries(
inode, group, desc, -1);
req->pr_entry_nr =
entries_per_group * group + pos;
kunmap(desc_bh->b_page);
kunmap(bitmap_bh->b_page);
req->pr_desc_bh = desc_bh;
req->pr_bitmap_bh = bitmap_bh;
return 0;
}
kunmap(bitmap_bh->b_page);
brelse(bitmap_bh);
}
group_offset = 0;
}
kunmap(desc_bh->b_page);
brelse(desc_bh);
}
/* no entries left */
return -ENOSPC;
out_desc:
kunmap(desc_bh->b_page);
brelse(desc_bh);
return ret;
}
void nilfs_palloc_commit_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
nilfs_mdt_mark_buffer_dirty(req->pr_bitmap_bh);
nilfs_mdt_mark_buffer_dirty(req->pr_desc_bh);
nilfs_mdt_mark_dirty(inode);
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
}
void nilfs_palloc_commit_free_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct nilfs_palloc_group_desc *desc;
unsigned long group, group_offset;
unsigned char *bitmap;
void *desc_kaddr, *bitmap_kaddr;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
desc_kaddr = kmap(req->pr_desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(inode, group,
req->pr_desc_bh, desc_kaddr);
bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
bitmap = nilfs_palloc_block_get_bitmap(inode, req->pr_bitmap_bh,
bitmap_kaddr);
if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
group_offset, bitmap))
printk(KERN_WARNING "%s: entry number %llu already freed\n",
__func__, (unsigned long long)req->pr_entry_nr);
nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
kunmap(req->pr_bitmap_bh->b_page);
kunmap(req->pr_desc_bh->b_page);
nilfs_mdt_mark_buffer_dirty(req->pr_desc_bh);
nilfs_mdt_mark_buffer_dirty(req->pr_bitmap_bh);
nilfs_mdt_mark_dirty(inode);
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
}
void nilfs_palloc_abort_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct nilfs_palloc_group_desc *desc;
void *desc_kaddr, *bitmap_kaddr;
unsigned char *bitmap;
unsigned long group, group_offset;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
desc_kaddr = kmap(req->pr_desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(inode, group,
req->pr_desc_bh, desc_kaddr);
bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
bitmap = nilfs_palloc_block_get_bitmap(inode, req->pr_bitmap_bh,
bitmap_kaddr);
if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
group_offset, bitmap))
printk(KERN_WARNING "%s: entry numer %llu already freed\n",
__func__, (unsigned long long)req->pr_entry_nr);
nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
kunmap(req->pr_bitmap_bh->b_page);
kunmap(req->pr_desc_bh->b_page);
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
req->pr_entry_nr = 0;
req->pr_bitmap_bh = NULL;
req->pr_desc_bh = NULL;
}
int nilfs_palloc_prepare_free_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct buffer_head *desc_bh, *bitmap_bh;
unsigned long group, group_offset;
int ret;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
if (ret < 0)
return ret;
ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
if (ret < 0) {
brelse(desc_bh);
return ret;
}
req->pr_desc_bh = desc_bh;
req->pr_bitmap_bh = bitmap_bh;
return 0;
}
void nilfs_palloc_abort_free_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
req->pr_entry_nr = 0;
req->pr_bitmap_bh = NULL;
req->pr_desc_bh = NULL;
}
static int
nilfs_palloc_group_is_in(struct inode *inode, unsigned long group, __u64 nr)
{
__u64 first, last;
first = group * nilfs_palloc_entries_per_group(inode);
last = first + nilfs_palloc_entries_per_group(inode) - 1;
return (nr >= first) && (nr <= last);
}
int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
void *desc_kaddr, *bitmap_kaddr;
unsigned long group, group_offset;
int i, j, n, ret;
for (i = 0; i < nitems; i += n) {
group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
if (ret < 0)
return ret;
ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
&bitmap_bh);
if (ret < 0) {
brelse(desc_bh);
return ret;
}
desc_kaddr = kmap(desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(
inode, group, desc_bh, desc_kaddr);
bitmap_kaddr = kmap(bitmap_bh->b_page);
bitmap = nilfs_palloc_block_get_bitmap(
inode, bitmap_bh, bitmap_kaddr);
for (j = i, n = 0;
(j < nitems) && nilfs_palloc_group_is_in(inode, group,
entry_nrs[j]);
j++, n++) {
nilfs_palloc_group(inode, entry_nrs[j], &group_offset);
if (!nilfs_clear_bit_atomic(
nilfs_mdt_bgl_lock(inode, group),
group_offset, bitmap)) {
printk(KERN_WARNING
"%s: entry number %llu already freed\n",
__func__,
(unsigned long long)entry_nrs[j]);
}
}
nilfs_palloc_group_desc_add_entries(inode, group, desc, n);
kunmap(bitmap_bh->b_page);
kunmap(desc_bh->b_page);
nilfs_mdt_mark_buffer_dirty(desc_bh);
nilfs_mdt_mark_buffer_dirty(bitmap_bh);
nilfs_mdt_mark_dirty(inode);
brelse(bitmap_bh);
brelse(desc_bh);
}
return 0;
}

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/*
* alloc.h - persistent object (dat entry/disk inode) allocator/deallocator
*
* 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
*
* Original code was written by Koji Sato <koji@osrg.net>.
* Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
* Amagai Yoshiji <amagai@osrg.net>.
*/
#ifndef _NILFS_ALLOC_H
#define _NILFS_ALLOC_H
#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
static inline unsigned long
nilfs_palloc_entries_per_group(const struct inode *inode)
{
return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
}
int nilfs_palloc_init_blockgroup(struct inode *, unsigned);
int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
struct buffer_head **);
void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
const struct buffer_head *, void *);
/**
* nilfs_palloc_req - persistent alloctor request and reply
* @pr_entry_nr: entry number (vblocknr or inode number)
* @pr_desc_bh: buffer head of the buffer containing block group descriptors
* @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
* @pr_entry_bh: buffer head of the buffer containing translation entries
*/
struct nilfs_palloc_req {
__u64 pr_entry_nr;
struct buffer_head *pr_desc_bh;
struct buffer_head *pr_bitmap_bh;
struct buffer_head *pr_entry_bh;
};
int nilfs_palloc_prepare_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_commit_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
#define nilfs_set_bit_atomic ext2_set_bit_atomic
#define nilfs_clear_bit_atomic ext2_clear_bit_atomic
#define nilfs_find_next_zero_bit ext2_find_next_zero_bit
#endif /* _NILFS_ALLOC_H */