original development tree for Linux kernel GTP module; now long in mainline.
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/*
* dat.c - NILFS disk address translation.
*
* 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/types.h>
#include <linux/buffer_head.h>
#include <linux/string.h>
#include <linux/errno.h>
#include "nilfs.h"
#include "mdt.h"
#include "alloc.h"
#include "dat.h"
#define NILFS_CNO_MIN ((__u64)1)
#define NILFS_CNO_MAX (~(__u64)0)
/**
* struct nilfs_dat_info - on-memory private data of DAT file
* @mi: on-memory private data of metadata file
* @palloc_cache: persistent object allocator cache of DAT file
* @shadow: shadow map of DAT file
*/
struct nilfs_dat_info {
struct nilfs_mdt_info mi;
struct nilfs_palloc_cache palloc_cache;
struct nilfs_shadow_map shadow;
};
static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
{
return (struct nilfs_dat_info *)NILFS_MDT(dat);
}
static int nilfs_dat_prepare_entry(struct inode *dat,
struct nilfs_palloc_req *req, int create)
{
return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
create, &req->pr_entry_bh);
}
static void nilfs_dat_commit_entry(struct inode *dat,
struct nilfs_palloc_req *req)
{
mark_buffer_dirty(req->pr_entry_bh);
nilfs_mdt_mark_dirty(dat);
brelse(req->pr_entry_bh);
}
static void nilfs_dat_abort_entry(struct inode *dat,
struct nilfs_palloc_req *req)
{
brelse(req->pr_entry_bh);
}
int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
int ret;
ret = nilfs_palloc_prepare_alloc_entry(dat, req);
if (ret < 0)
return ret;
ret = nilfs_dat_prepare_entry(dat, req, 1);
if (ret < 0)
nilfs_palloc_abort_alloc_entry(dat, req);
return ret;
}
void nilfs_dat_commit_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
struct nilfs_dat_entry *entry;
void *kaddr;
kaddr = kmap_atomic(req->pr_entry_bh->b_page);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
entry->de_blocknr = cpu_to_le64(0);
kunmap_atomic(kaddr);
nilfs_palloc_commit_alloc_entry(dat, req);
nilfs_dat_commit_entry(dat, req);
}
void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
nilfs_dat_abort_entry(dat, req);
nilfs_palloc_abort_alloc_entry(dat, req);
}
static void nilfs_dat_commit_free(struct inode *dat,
struct nilfs_palloc_req *req)
{
struct nilfs_dat_entry *entry;
void *kaddr;
kaddr = kmap_atomic(req->pr_entry_bh->b_page);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
entry->de_blocknr = cpu_to_le64(0);
kunmap_atomic(kaddr);
nilfs_dat_commit_entry(dat, req);
nilfs_palloc_commit_free_entry(dat, req);
}
int nilfs_dat_prepare_start(struct inode *dat, struct nilfs_palloc_req *req)
{
int ret;
ret = nilfs_dat_prepare_entry(dat, req, 0);
WARN_ON(ret == -ENOENT);
return ret;
}
void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
sector_t blocknr)
{
struct nilfs_dat_entry *entry;
void *kaddr;
kaddr = kmap_atomic(req->pr_entry_bh->b_page);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
entry->de_blocknr = cpu_to_le64(blocknr);
kunmap_atomic(kaddr);
nilfs_dat_commit_entry(dat, req);
}
int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)
{
struct nilfs_dat_entry *entry;
__u64 start;
sector_t blocknr;
void *kaddr;
int ret;
ret = nilfs_dat_prepare_entry(dat, req, 0);
if (ret < 0) {
WARN_ON(ret == -ENOENT);
return ret;
}
kaddr = kmap_atomic(req->pr_entry_bh->b_page);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
start = le64_to_cpu(entry->de_start);
blocknr = le64_to_cpu(entry->de_blocknr);
kunmap_atomic(kaddr);
if (blocknr == 0) {
ret = nilfs_palloc_prepare_free_entry(dat, req);
if (ret < 0) {
nilfs_dat_abort_entry(dat, req);
return ret;
}
}
return 0;
}
void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
int dead)
{
struct nilfs_dat_entry *entry;
__u64 start, end;
sector_t blocknr;
void *kaddr;
kaddr = kmap_atomic(req->pr_entry_bh->b_page);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
end = start = le64_to_cpu(entry->de_start);
if (!dead) {
end = nilfs_mdt_cno(dat);
WARN_ON(start > end);
}
entry->de_end = cpu_to_le64(end);
blocknr = le64_to_cpu(entry->de_blocknr);
kunmap_atomic(kaddr);
if (blocknr == 0)
nilfs_dat_commit_free(dat, req);
else
nilfs_dat_commit_entry(dat, req);
}
void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
{
struct nilfs_dat_entry *entry;
__u64 start;
sector_t blocknr;
void *kaddr;
kaddr = kmap_atomic(req->pr_entry_bh->b_page);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
start = le64_to_cpu(entry->de_start);
blocknr = le64_to_cpu(entry->de_blocknr);
kunmap_atomic(kaddr);
if (start == nilfs_mdt_cno(dat) && blocknr == 0)
nilfs_palloc_abort_free_entry(dat, req);
nilfs_dat_abort_entry(dat, req);
}
int nilfs_dat_prepare_update(struct inode *dat,
struct nilfs_palloc_req *oldreq,
struct nilfs_palloc_req *newreq)
{
int ret;
ret = nilfs_dat_prepare_end(dat, oldreq);
if (!ret) {
ret = nilfs_dat_prepare_alloc(dat, newreq);
if (ret < 0)
nilfs_dat_abort_end(dat, oldreq);
}
return ret;
}
void nilfs_dat_commit_update(struct inode *dat,
struct nilfs_palloc_req *oldreq,
struct nilfs_palloc_req *newreq, int dead)
{
nilfs_dat_commit_end(dat, oldreq, dead);
nilfs_dat_commit_alloc(dat, newreq);
}
void nilfs_dat_abort_update(struct inode *dat,
struct nilfs_palloc_req *oldreq,
struct nilfs_palloc_req *newreq)
{
nilfs_dat_abort_end(dat, oldreq);
nilfs_dat_abort_alloc(dat, newreq);
}
/**
* nilfs_dat_mark_dirty -
* @dat: DAT file inode
* @vblocknr: virtual block number
*
* Description:
*
* 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_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
{
struct nilfs_palloc_req req;
int ret;
req.pr_entry_nr = vblocknr;
ret = nilfs_dat_prepare_entry(dat, &req, 0);
if (ret == 0)
nilfs_dat_commit_entry(dat, &req);
return ret;
}
/**
* nilfs_dat_freev - free virtual block numbers
* @dat: DAT file inode
* @vblocknrs: array of virtual block numbers
* @nitems: number of virtual block numbers
*
* Description: nilfs_dat_freev() frees the virtual block numbers specified by
* @vblocknrs and @nitems.
*
* 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 - The virtual block number have not been allocated.
*/
int nilfs_dat_freev(struct inode *dat, __u64 *vblocknrs, size_t nitems)
{
return nilfs_palloc_freev(dat, vblocknrs, nitems);
}
/**
* nilfs_dat_move - change a block number
* @dat: DAT file inode
* @vblocknr: virtual block number
* @blocknr: block number
*
* Description: nilfs_dat_move() changes the block number associated with
* @vblocknr to @blocknr.
*
* 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_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
{
struct buffer_head *entry_bh;
struct nilfs_dat_entry *entry;
void *kaddr;
int ret;
ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
if (ret < 0)
return ret;
/*
* The given disk block number (blocknr) is not yet written to
* the device at this point.
*
* To prevent nilfs_dat_translate() from returning the
* uncommitted block number, this makes a copy of the entry
* buffer and redirects nilfs_dat_translate() to the copy.
*/
if (!buffer_nilfs_redirected(entry_bh)) {
ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
if (ret) {
brelse(entry_bh);
return ret;
}
}
kaddr = kmap_atomic(entry_bh->b_page);
entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
(unsigned long long)vblocknr,
(unsigned long long)le64_to_cpu(entry->de_start),
(unsigned long long)le64_to_cpu(entry->de_end));
kunmap_atomic(kaddr);
brelse(entry_bh);
return -EINVAL;
}
WARN_ON(blocknr == 0);
entry->de_blocknr = cpu_to_le64(blocknr);
kunmap_atomic(kaddr);
mark_buffer_dirty(entry_bh);
nilfs_mdt_mark_dirty(dat);
brelse(entry_bh);
return 0;
}
/**
* nilfs_dat_translate - translate a virtual block number to a block number
* @dat: DAT file inode
* @vblocknr: virtual block number
* @blocknrp: pointer to a block number
*
* Description: nilfs_dat_translate() maps the virtual block number @vblocknr
* to the corresponding block number.
*
* Return Value: On success, 0 is returned and the block number associated
* with @vblocknr is stored in the place pointed by @blocknrp. On error, one
* of the following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOENT - A block number associated with @vblocknr does not exist.
*/
int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
{
struct buffer_head *entry_bh, *bh;
struct nilfs_dat_entry *entry;
sector_t blocknr;
void *kaddr;
int ret;
ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
if (ret < 0)
return ret;
if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
if (bh) {
WARN_ON(!buffer_uptodate(bh));
brelse(entry_bh);
entry_bh = bh;
}
}
kaddr = kmap_atomic(entry_bh->b_page);
entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
blocknr = le64_to_cpu(entry->de_blocknr);
if (blocknr == 0) {
ret = -ENOENT;
goto out;
}
*blocknrp = blocknr;
out:
kunmap_atomic(kaddr);
brelse(entry_bh);
return ret;
}
ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned visz,
size_t nvi)
{
struct buffer_head *entry_bh;
struct nilfs_dat_entry *entry;
struct nilfs_vinfo *vinfo = buf;
__u64 first, last;
void *kaddr;
unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
int i, j, n, ret;
for (i = 0; i < nvi; i += n) {
ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
0, &entry_bh);
if (ret < 0)
return ret;
kaddr = kmap_atomic(entry_bh->b_page);
/* last virtual block number in this block */
first = vinfo->vi_vblocknr;
do_div(first, entries_per_block);
first *= entries_per_block;
last = first + entries_per_block - 1;
for (j = i, n = 0;
j < nvi && vinfo->vi_vblocknr >= first &&
vinfo->vi_vblocknr <= last;
j++, n++, vinfo = (void *)vinfo + visz) {
entry = nilfs_palloc_block_get_entry(
dat, vinfo->vi_vblocknr, entry_bh, kaddr);
vinfo->vi_start = le64_to_cpu(entry->de_start);
vinfo->vi_end = le64_to_cpu(entry->de_end);
vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
}
kunmap_atomic(kaddr);
brelse(entry_bh);
}
return nvi;
}
/**
* nilfs_dat_read - read or get dat inode
* @sb: super block instance
* @entry_size: size of a dat entry
* @raw_inode: on-disk dat inode
* @inodep: buffer to store the inode
*/
int nilfs_dat_read(struct super_block *sb, size_t entry_size,
struct nilfs_inode *raw_inode, struct inode **inodep)
{
static struct lock_class_key dat_lock_key;
struct inode *dat;
struct nilfs_dat_info *di;
int err;
dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
if (unlikely(!dat))
return -ENOMEM;
if (!(dat->i_state & I_NEW))
goto out;
err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
if (err)
goto failed;
err = nilfs_palloc_init_blockgroup(dat, entry_size);
if (err)
goto failed;
di = NILFS_DAT_I(dat);
lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
nilfs_palloc_setup_cache(dat, &di->palloc_cache);
nilfs_mdt_setup_shadow_map(dat, &di->shadow);
err = nilfs_read_inode_common(dat, raw_inode);
if (err)
goto failed;
unlock_new_inode(dat);
out:
*inodep = dat;
return 0;
failed:
iget_failed(dat);
return err;
}