/*
* sufile.c - NILFS segment usage file.
*
* 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/kernel.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/errno.h>
#include <linux/nilfs2_fs.h>
#include "mdt.h"
#include "sufile.h"
static inline unsigned long
nilfs_sufile_segment_usages_per_block(const struct inode *sufile)
{
return NILFS_MDT(sufile)->mi_entries_per_block;
}
static unsigned long
nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum)
{
__u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
return (unsigned long)t;
}
static unsigned long
nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum)
{
__u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
return do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
}
static unsigned long
nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr,
__u64 max)
{
return min_t(unsigned long,
nilfs_sufile_segment_usages_per_block(sufile) -
nilfs_sufile_get_offset(sufile, curr),
max - curr + 1);
}
static inline struct nilfs_sufile_header *
nilfs_sufile_block_get_header(const struct inode *sufile,
struct buffer_head *bh,
void *kaddr)
{
return kaddr + bh_offset(bh);
}
static struct nilfs_segment_usage *
nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum,
struct buffer_head *bh, void *kaddr)
{
return kaddr + bh_offset(bh) +
nilfs_sufile_get_offset(sufile, segnum) *
NILFS_MDT(sufile)->mi_entry_size;
}
static inline int nilfs_sufile_get_header_block(struct inode *sufile,
struct buffer_head **bhp)
{
return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
}
static inline int
nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
int create, struct buffer_head **bhp)
{
return nilfs_mdt_get_block(sufile,
nilfs_sufile_get_blkoff(sufile, segnum),
create, NULL, bhp);
}
/**
* nilfs_sufile_alloc - allocate a segment
* @sufile: inode of segment usage file
* @segnump: pointer to segment number
*
* Description: nilfs_sufile_alloc() allocates a clean segment.
*
* Return Value: On success, 0 is returned and the segment number of the
* allocated segment is stored in the place pointed by @segnump. On error, one
* of the following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOSPC - No clean segment left.
*/
int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
{
struct buffer_head *header_bh, *su_bh;
struct the_nilfs *nilfs;
struct nilfs_sufile_header *header;
struct nilfs_segment_usage *su;
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
__u64 segnum, maxsegnum, last_alloc;
void *kaddr;
unsigned long nsegments, ncleansegs, nsus;
int ret, i, j;
down_write(&NILFS_MDT(sufile)->mi_sem);
nilfs = NILFS_MDT(sufile)->mi_nilfs;
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_sem;
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
ncleansegs = le64_to_cpu(header->sh_ncleansegs);
last_alloc = le64_to_cpu(header->sh_last_alloc);
kunmap_atomic(kaddr, KM_USER0);
nsegments = nilfs_sufile_get_nsegments(sufile);
segnum = last_alloc + 1;
maxsegnum = nsegments - 1;
for (i = 0; i < nsegments; i += nsus) {
if (segnum >= nsegments) {
/* wrap around */
segnum = 0;
maxsegnum = last_alloc;
}
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
&su_bh);
if (ret < 0)
goto out_header;
kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
nsus = nilfs_sufile_segment_usages_in_block(
sufile, segnum, maxsegnum);
for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
if (!nilfs_segment_usage_clean(su))
continue;
/* found a clean segment */
nilfs_segment_usage_set_active(su);
nilfs_segment_usage_set_dirty(su);
kunmap_atomic(kaddr, KM_USER0);
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = nilfs_sufile_block_get_header(
sufile, header_bh, kaddr);
le64_add_cpu(&header->sh_ncleansegs, -1);
le64_add_cpu(&header->sh_ndirtysegs, 1);
header->sh_last_alloc = cpu_to_le64(segnum);
kunmap_atomic(kaddr, KM_USER0);
nilfs_mdt_mark_buffer_dirty(header_bh);
nilfs_mdt_mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
brelse(su_bh);
*segnump = segnum;
goto out_header;
}
kunmap_atomic(kaddr, KM_USER0);
brelse(su_bh);
}
/* no segments left */
ret = -ENOSPC;
out_header:
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_cancel_free -
* @sufile: inode of segment usage file
* @segnum: segment 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_sufile_cancel_free(struct inode *sufile, __u64 segnum)
{
struct buffer_head *header_bh, *su_bh;
struct the_nilfs *nilfs;
struct nilfs_sufile_header *header;
struct nilfs_segment_usage *su;
void *kaddr;
int ret;
down_write(&NILFS_MDT(sufile)->mi_sem);
nilfs = NILFS_MDT(sufile)->mi_nilfs;
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_sem;
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &su_bh);
if (ret < 0)
goto out_header;
kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
if (!nilfs_segment_usage_clean(su)) {
printk(KERN_CRIT "%s: segment %llu must be clean\n",
__func__, (unsigned long long)segnum);
BUG();
}
nilfs_segment_usage_set_dirty(su);
kunmap_atomic(kaddr, KM_USER0);
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
le64_add_cpu(&header->sh_ncleansegs, -1);
le64_add_cpu(&header->sh_ndirtysegs, 1);
kunmap_atomic(kaddr, KM_USER0);
nilfs_mdt_mark_buffer_dirty(header_bh);
nilfs_mdt_mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
brelse(su_bh);
out_header:
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_freev - free segments
* @sufile: inode of segment usage file
* @segnum: array of segment numbers
* @nsegs: number of segments
*
* Description: nilfs_sufile_freev() frees segments specified by @segnum and
* @nsegs, which must have been returned by a previous call to
* nilfs_sufile_alloc().
*
* 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.
*/
#define NILFS_SUFILE_FREEV_PREALLOC 16
int nilfs_sufile_freev(struct inode *sufile, __u64 *segnum, size_t nsegs)
{
struct buffer_head *header_bh, **su_bh,
*su_bh_prealloc[NILFS_SUFILE_FREEV_PREALLOC];
struct the_nilfs *nilfs;
struct nilfs_sufile_header *header;
struct nilfs_segment_usage *su;
void *kaddr;
int ret, i;
down_write(&NILFS_MDT(sufile)->mi_sem);
nilfs = NILFS_MDT(sufile)->mi_nilfs;
/* prepare resources */
if (nsegs <= NILFS_SUFILE_FREEV_PREALLOC)
su_bh = su_bh_prealloc;
else {
su_bh = kmalloc(sizeof(*su_bh) * nsegs, GFP_NOFS);
if (su_bh == NULL) {
ret = -ENOMEM;
goto out_sem;
}
}
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_su_bh;
for (i = 0; i < nsegs; i++) {
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum[i],
0, &su_bh[i]);
if (ret < 0)
goto out_bh;
}
/* free segments */
for (i = 0; i < nsegs; i++) {
kaddr = kmap_atomic(su_bh[i]->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum[i], su_bh[i], kaddr);
BUG_ON(nilfs_segment_usage_error(su));
nilfs_segment_usage_set_clean(su);
kunmap_atomic(kaddr, KM_USER0);
nilfs_mdt_mark_buffer_dirty(su_bh[i]);
}
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
le64_add_cpu(&header->sh_ncleansegs, nsegs);
le64_add_cpu(&header->sh_ndirtysegs, -(u64)nsegs);
kunmap_atomic(kaddr, KM_USER0);
nilfs_mdt_mark_buffer_dirty(header_bh);
nilfs_mdt_mark_dirty(sufile);
out_bh:
for (i--; i >= 0; i--)
brelse(su_bh[i]);
brelse(header_bh);
out_su_bh:
if (su_bh != su_bh_prealloc)
kfree(su_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_free -
* @sufile:
* @segnum:
*/
int nilfs_sufile_free(struct inode *sufile, __u64 segnum)
{
return nilfs_sufile_freev(sufile, &segnum, 1);
}
/**
* nilfs_sufile_get_segment_usage - get a segment usage
* @sufile: inode of segment usage file
* @segnum: segment number
* @sup: pointer to segment usage
* @bhp: pointer to buffer head
*
* Description: nilfs_sufile_get_segment_usage() acquires the segment usage
* specified by @segnum.
*
* Return Value: On success, 0 is returned, and the segment usage and the
* buffer head of the buffer on which the segment usage is located are stored
* in the place pointed by @sup and @bhp, respectively. On error, one of the
* following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-EINVAL - Invalid segment usage number.
*/
int nilfs_sufile_get_segment_usage(struct inode *sufile, __u64 segnum,
struct nilfs_segment_usage **sup,
struct buffer_head **bhp)
{
struct buffer_head *bh;
struct nilfs_segment_usage *su;
void *kaddr;
int ret;
/* segnum is 0 origin */
BUG_ON(segnum >= nilfs_sufile_get_nsegments(sufile));
down_write(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1, &bh);
if (ret < 0)
goto out_sem;
kaddr = kmap(bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
if (nilfs_segment_usage_error(su)) {
kunmap(bh->b_page);
brelse(bh);
ret = -EINVAL;
goto out_sem;
}
if (sup != NULL)
*sup = su;
*bhp = bh;
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_put_segment_usage - put a segment usage
* @sufile: inode of segment usage file
* @segnum: segment number
* @bh: buffer head
*
* Description: nilfs_sufile_put_segment_usage() releases the segment usage
* specified by @segnum. @bh must be the buffer head which have been returned
* by a previous call to nilfs_sufile_get_segment_usage() with @segnum.
*/
void nilfs_sufile_put_segment_usage(struct inode *sufile, __u64 segnum,
struct buffer_head *bh)
{
kunmap(bh->b_page);
brelse(bh);
}
/**
* nilfs_sufile_get_stat - get segment usage statistics
* @sufile: inode of segment usage file
* @stat: pointer to a structure of segment usage statistics
*
* Description: nilfs_sufile_get_stat() returns information about segment
* usage.
*
* Return Value: On success, 0 is returned, and segment usage information is
* stored in the place pointed by @stat. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
{
struct buffer_head *header_bh;
struct nilfs_sufile_header *header;
void *kaddr;
int ret;
down_read(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_sem;
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
sustat->ss_ctime = NILFS_MDT(sufile)->mi_nilfs->ns_ctime;
sustat->ss_nongc_ctime = NILFS_MDT(sufile)->mi_nilfs->ns_nongc_ctime;
kunmap_atomic(kaddr, KM_USER0);
brelse(header_bh);
out_sem:
up_read(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_get_ncleansegs - get the number of clean segments
* @sufile: inode of segment usage file
* @nsegsp: pointer to the number of clean segments
*
* Description: nilfs_sufile_get_ncleansegs() acquires the number of clean
* segments.
*
* Return Value: On success, 0 is returned and the number of clean segments is
* stored in the place pointed by @nsegsp. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_sufile_get_ncleansegs(struct inode *sufile, unsigned long *nsegsp)
{
struct nilfs_sustat sustat;
int ret;
ret = nilfs_sufile_get_stat(sufile, &sustat);
if (ret == 0)
*nsegsp = sustat.ss_ncleansegs;
return ret;
}
/**
* nilfs_sufile_set_error - mark a segment as erroneous
* @sufile: inode of segment usage file
* @segnum: segment number
*
* Description: nilfs_sufile_set_error() marks the segment specified by
* @segnum as erroneous. The error segment will never be used again.
*
* 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_sufile_set_error(struct inode *sufile, __u64 segnum)
{
struct buffer_head *header_bh, *su_bh;
struct nilfs_segment_usage *su;
struct nilfs_sufile_header *header;
void *kaddr;
int ret;
BUG_ON(segnum >= nilfs_sufile_get_nsegments(sufile));
down_write(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_sem;
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &su_bh);
if (ret < 0)
goto out_header;
kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
if (nilfs_segment_usage_error(su)) {
kunmap_atomic(kaddr, KM_USER0);
brelse(su_bh);
goto out_header;
}
nilfs_segment_usage_set_error(su);
kunmap_atomic(kaddr, KM_USER0);
brelse(su_bh);
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
le64_add_cpu(&header->sh_ndirtysegs, -1);
kunmap_atomic(kaddr, KM_USER0);
nilfs_mdt_mark_buffer_dirty(header_bh);
nilfs_mdt_mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
brelse(su_bh);
out_header:
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_get_suinfo -
* @sufile: inode of segment usage file
* @segnum: segment number to start looking
* @si: array of suinfo
* @nsi: size of suinfo array
*
* Description:
*
* Return Value: On success, 0 is returned and .... On error, one of the
* following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum,
struct nilfs_suinfo *si, size_t nsi)
{
struct buffer_head *su_bh;
struct nilfs_segment_usage *su;
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
void *kaddr;
unsigned long nsegs, segusages_per_block;
ssize_t n;
int ret, i, j;
down_read(&NILFS_MDT(sufile)->mi_sem);
segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
nsegs = min_t(unsigned long,
nilfs_sufile_get_nsegments(sufile) - segnum,
nsi);
for (i = 0; i < nsegs; i += n, segnum += n) {
n = min_t(unsigned long,
segusages_per_block -
nilfs_sufile_get_offset(sufile, segnum),
nsegs - i);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
&su_bh);
if (ret < 0) {
if (ret != -ENOENT)
goto out;
/* hole */
memset(&si[i], 0, sizeof(struct nilfs_suinfo) * n);
continue;
}
kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
for (j = 0; j < n; j++, su = (void *)su + susz) {
si[i + j].sui_lastmod = le64_to_cpu(su->su_lastmod);
si[i + j].sui_nblocks = le32_to_cpu(su->su_nblocks);
si[i + j].sui_flags = le32_to_cpu(su->su_flags);
}
kunmap_atomic(kaddr, KM_USER0);
brelse(su_bh);
}
ret = nsegs;
out:
up_read(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
