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alistair23-linux/fs/nilfs2/sufile.c
Ryusuke Konishi cece552074 nilfs2: simplify handling of active state of segments 
will reduce some lines of segment constructor.  Previously, the state was
complexly controlled through a list of segments in order to keep
consistency in meta data of usage state of segments.  Instead, this
presents ``calculated'' active flags to userland cleaner program and stop
maintaining its real flag on disk.

Only by this fake flag, the cleaner cannot exactly know if each segment is
reclaimable or not.  However, the recent extension of nilfs_sustat ioctl
struct (nilfs2-extend-nilfs_sustat-ioctl-struct.patch) can prevent the
cleaner from reclaiming in-use segment wrongly.

So, now I can apply this for simplification.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 08:31:20 -07:00

641 lines
18 KiB
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/*
* 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_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 (unlikely(!nilfs_segment_usage_clean(su))) {
printk(KERN_WARNING "%s: segment %llu must be clean\n",
__func__, (unsigned long long)segnum);
kunmap_atomic(kaddr, KM_USER0);
goto out_su_bh;
}
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);
out_su_bh:
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);
WARN_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 */
if (segnum >= nilfs_sufile_get_nsegments(sufile))
return -EINVAL;
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;
struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs;
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->ns_ctime;
sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
spin_lock(&nilfs->ns_last_segment_lock);
sustat->ss_prot_seq = nilfs->ns_prot_seq;
spin_unlock(&nilfs->ns_last_segment_lock);
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.
*
* %-EINVAL - Invalid segment usage number.
*/
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;
if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
printk(KERN_WARNING "%s: invalid segment number: %llu\n",
__func__, (unsigned long long)segnum);
return -EINVAL;
}
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;
struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs;
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) &
~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
if (nilfs_segment_is_active(nilfs, segnum + i + j))
si[i + j].sui_flags |=
(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
}
kunmap_atomic(kaddr, KM_USER0);
brelse(su_bh);
}
ret = nsegs;
out:
up_read(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
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