original development tree for Linux kernel GTP module; now long in mainline.
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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>.
* Revised by Ryusuke Konishi <ryusuke@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"
/**
* struct nilfs_sufile_info - on-memory private data of sufile
* @mi: on-memory private data of metadata file
* @ncleansegs: number of clean segments
* @allocmin: lower limit of allocatable segment range
* @allocmax: upper limit of allocatable segment range
*/
struct nilfs_sufile_info {
struct nilfs_mdt_info mi;
unsigned long ncleansegs;/* number of clean segments */
__u64 allocmin; /* lower limit of allocatable segment range */
__u64 allocmax; /* upper limit of allocatable segment range */
};
static inline struct nilfs_sufile_info *NILFS_SUI(struct inode *sufile)
{
return (struct nilfs_sufile_info *)NILFS_MDT(sufile);
}
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 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);
}
static int nilfs_sufile_delete_segment_usage_block(struct inode *sufile,
__u64 segnum)
{
return nilfs_mdt_delete_block(sufile,
nilfs_sufile_get_blkoff(sufile, segnum));
}
static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
u64 ncleanadd, u64 ndirtyadd)
{
struct nilfs_sufile_header *header;
void *kaddr;
kaddr = kmap_atomic(header_bh->b_page);
header = kaddr + bh_offset(header_bh);
le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
kunmap_atomic(kaddr);
mark_buffer_dirty(header_bh);
}
/**
* nilfs_sufile_get_ncleansegs - return the number of clean segments
* @sufile: inode of segment usage file
*/
unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile)
{
return NILFS_SUI(sufile)->ncleansegs;
}
/**
* nilfs_sufile_updatev - modify multiple segment usages at a time
* @sufile: inode of segment usage file
* @segnumv: array of segment numbers
* @nsegs: size of @segnumv array
* @create: creation flag
* @ndone: place to store number of modified segments on @segnumv
* @dofunc: primitive operation for the update
*
* Description: nilfs_sufile_updatev() repeatedly calls @dofunc
* against the given array of segments. The @dofunc is called with
* buffers of a header block and the sufile block in which the target
* segment usage entry is contained. If @ndone is given, the number
* of successfully modified segments from the head is stored in the
* place @ndone points to.
*
* Return Value: On success, zero is returned. On error, one of the
* following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOENT - Given segment usage is in hole block (may be returned if
* @create is zero)
*
* %-EINVAL - Invalid segment usage number
*/
int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
int create, size_t *ndone,
void (*dofunc)(struct inode *, __u64,
struct buffer_head *,
struct buffer_head *))
{
struct buffer_head *header_bh, *bh;
unsigned long blkoff, prev_blkoff;
__u64 *seg;
size_t nerr = 0, n = 0;
int ret = 0;
if (unlikely(nsegs == 0))
goto out;
down_write(&NILFS_MDT(sufile)->mi_sem);
for (seg = segnumv; seg < segnumv + nsegs; seg++) {
if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
printk(KERN_WARNING
"%s: invalid segment number: %llu\n", __func__,
(unsigned long long)*seg);
nerr++;
}
}
if (nerr > 0) {
ret = -EINVAL;
goto out_sem;
}
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_sem;
seg = segnumv;
blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
if (ret < 0)
goto out_header;
for (;;) {
dofunc(sufile, *seg, header_bh, bh);
if (++seg >= segnumv + nsegs)
break;
prev_blkoff = blkoff;
blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
if (blkoff == prev_blkoff)
continue;
/* get different block */
brelse(bh);
ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
if (unlikely(ret < 0))
goto out_header;
}
brelse(bh);
out_header:
n = seg - segnumv;
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
out:
if (ndone)
*ndone = n;
return ret;
}
int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
void (*dofunc)(struct inode *, __u64,
struct buffer_head *,
struct buffer_head *))
{
struct buffer_head *header_bh, *bh;
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, create, &bh);
if (!ret) {
dofunc(sufile, segnum, header_bh, bh);
brelse(bh);
}
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_set_alloc_range - limit range of segment to be allocated
* @sufile: inode of segment usage file
* @start: minimum segment number of allocatable region (inclusive)
* @end: maximum segment number of allocatable region (inclusive)
*
* Return Value: On success, 0 is returned. On error, one of the
* following negative error codes is returned.
*
* %-ERANGE - invalid segment region
*/
int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
{
struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
__u64 nsegs;
int ret = -ERANGE;
down_write(&NILFS_MDT(sufile)->mi_sem);
nsegs = nilfs_sufile_get_nsegments(sufile);
if (start <= end && end < nsegs) {
sui->allocmin = start;
sui->allocmax = end;
ret = 0;
}
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* 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 nilfs_sufile_header *header;
struct nilfs_segment_usage *su;
struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
__u64 segnum, maxsegnum, last_alloc;
void *kaddr;
unsigned long nsegments, ncleansegs, nsus, cnt;
int ret, j;
down_write(&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);
header = kaddr + bh_offset(header_bh);
ncleansegs = le64_to_cpu(header->sh_ncleansegs);
last_alloc = le64_to_cpu(header->sh_last_alloc);
kunmap_atomic(kaddr);
nsegments = nilfs_sufile_get_nsegments(sufile);
maxsegnum = sui->allocmax;
segnum = last_alloc + 1;
if (segnum < sui->allocmin || segnum > sui->allocmax)
segnum = sui->allocmin;
for (cnt = 0; cnt < nsegments; cnt += nsus) {
if (segnum > maxsegnum) {
if (cnt < sui->allocmax - sui->allocmin + 1) {
/*
* wrap around in the limited region.
* if allocation started from
* sui->allocmin, this never happens.
*/
segnum = sui->allocmin;
maxsegnum = last_alloc;
} else if (segnum > sui->allocmin &&
sui->allocmax + 1 < nsegments) {
segnum = sui->allocmax + 1;
maxsegnum = nsegments - 1;
} else if (sui->allocmin > 0) {
segnum = 0;
maxsegnum = sui->allocmin - 1;
} else {
break; /* never happens */
}
}
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);
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);
kaddr = kmap_atomic(header_bh->b_page);
header = kaddr + bh_offset(header_bh);
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);
sui->ncleansegs--;
mark_buffer_dirty(header_bh);
mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
brelse(su_bh);
*segnump = segnum;
goto out_header;
}
kunmap_atomic(kaddr);
brelse(su_bh);
}
/* no segments left */
ret = -ENOSPC;
out_header:
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
struct buffer_head *header_bh,
struct buffer_head *su_bh)
{
struct nilfs_segment_usage *su;
void *kaddr;
kaddr = kmap_atomic(su_bh->b_page);
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);
return;
}
nilfs_segment_usage_set_dirty(su);
kunmap_atomic(kaddr);
nilfs_sufile_mod_counter(header_bh, -1, 1);
NILFS_SUI(sufile)->ncleansegs--;
mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
}
void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
struct buffer_head *header_bh,
struct buffer_head *su_bh)
{
struct nilfs_segment_usage *su;
void *kaddr;
int clean, dirty;
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
if (su->su_flags == cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY) &&
su->su_nblocks == cpu_to_le32(0)) {
kunmap_atomic(kaddr);
return;
}
clean = nilfs_segment_usage_clean(su);
dirty = nilfs_segment_usage_dirty(su);
/* make the segment garbage */
su->su_lastmod = cpu_to_le64(0);
su->su_nblocks = cpu_to_le32(0);
su->su_flags = cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY);
kunmap_atomic(kaddr);
nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
NILFS_SUI(sufile)->ncleansegs -= clean;
mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
}
void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
struct buffer_head *header_bh,
struct buffer_head *su_bh)
{
struct nilfs_segment_usage *su;
void *kaddr;
int sudirty;
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
if (nilfs_segment_usage_clean(su)) {
printk(KERN_WARNING "%s: segment %llu is already clean\n",
__func__, (unsigned long long)segnum);
kunmap_atomic(kaddr);
return;
}
WARN_ON(nilfs_segment_usage_error(su));
WARN_ON(!nilfs_segment_usage_dirty(su));
sudirty = nilfs_segment_usage_dirty(su);
nilfs_segment_usage_set_clean(su);
kunmap_atomic(kaddr);
mark_buffer_dirty(su_bh);
nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
NILFS_SUI(sufile)->ncleansegs++;
nilfs_mdt_mark_dirty(sufile);
}
/**
* nilfs_sufile_mark_dirty - mark the buffer having a segment usage dirty
* @sufile: inode of segment usage file
* @segnum: segment number
*/
int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
{
struct buffer_head *bh;
int ret;
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
if (!ret) {
mark_buffer_dirty(bh);
nilfs_mdt_mark_dirty(sufile);
brelse(bh);
}
return ret;
}
/**
* nilfs_sufile_set_segment_usage - set usage of a segment
* @sufile: inode of segment usage file
* @segnum: segment number
* @nblocks: number of live blocks in the segment
* @modtime: modification time (option)
*/
int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
unsigned long nblocks, time_t modtime)
{
struct buffer_head *bh;
struct nilfs_segment_usage *su;
void *kaddr;
int ret;
down_write(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
if (ret < 0)
goto out_sem;
kaddr = kmap_atomic(bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
WARN_ON(nilfs_segment_usage_error(su));
if (modtime)
su->su_lastmod = cpu_to_le64(modtime);
su->su_nblocks = cpu_to_le32(nblocks);
kunmap_atomic(kaddr);
mark_buffer_dirty(bh);
nilfs_mdt_mark_dirty(sufile);
brelse(bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* 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 = sufile->i_sb->s_fs_info;
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);
header = kaddr + bh_offset(header_bh);
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);
brelse(header_bh);
out_sem:
up_read(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
struct buffer_head *header_bh,
struct buffer_head *su_bh)
{
struct nilfs_segment_usage *su;
void *kaddr;
int suclean;
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
if (nilfs_segment_usage_error(su)) {
kunmap_atomic(kaddr);
return;
}
suclean = nilfs_segment_usage_clean(su);
nilfs_segment_usage_set_error(su);
kunmap_atomic(kaddr);
if (suclean) {
nilfs_sufile_mod_counter(header_bh, -1, 0);
NILFS_SUI(sufile)->ncleansegs--;
}
mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
}
/**
* nilfs_sufile_truncate_range - truncate range of segment array
* @sufile: inode of segment usage file
* @start: start segment number (inclusive)
* @end: end segment number (inclusive)
*
* 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 number of segments specified
*
* %-EBUSY - Dirty or active segments are present in the range
*/
static int nilfs_sufile_truncate_range(struct inode *sufile,
__u64 start, __u64 end)
{
struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
struct buffer_head *header_bh;
struct buffer_head *su_bh;
struct nilfs_segment_usage *su, *su2;
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
unsigned long segusages_per_block;
unsigned long nsegs, ncleaned;
__u64 segnum;
void *kaddr;
ssize_t n, nc;
int ret;
int j;
nsegs = nilfs_sufile_get_nsegments(sufile);
ret = -EINVAL;
if (start > end || start >= nsegs)
goto out;
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out;
segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
ncleaned = 0;
for (segnum = start; segnum <= end; segnum += n) {
n = min_t(unsigned long,
segusages_per_block -
nilfs_sufile_get_offset(sufile, segnum),
end - segnum + 1);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
&su_bh);
if (ret < 0) {
if (ret != -ENOENT)
goto out_header;
/* hole */
continue;
}
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
su2 = su;
for (j = 0; j < n; j++, su = (void *)su + susz) {
if ((le32_to_cpu(su->su_flags) &
~(1UL << NILFS_SEGMENT_USAGE_ERROR)) ||
nilfs_segment_is_active(nilfs, segnum + j)) {
ret = -EBUSY;
kunmap_atomic(kaddr);
brelse(su_bh);
goto out_header;
}
}
nc = 0;
for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
if (nilfs_segment_usage_error(su)) {
nilfs_segment_usage_set_clean(su);
nc++;
}
}
kunmap_atomic(kaddr);
if (nc > 0) {
mark_buffer_dirty(su_bh);
ncleaned += nc;
}
brelse(su_bh);
if (n == segusages_per_block) {
/* make hole */
nilfs_sufile_delete_segment_usage_block(sufile, segnum);
}
}
ret = 0;
out_header:
if (ncleaned > 0) {
NILFS_SUI(sufile)->ncleansegs += ncleaned;
nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
nilfs_mdt_mark_dirty(sufile);
}
brelse(header_bh);
out:
return ret;
}
/**
* nilfs_sufile_resize - resize segment array
* @sufile: inode of segment usage file
* @newnsegs: new number of segments
*
* 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.
*
* %-ENOSPC - Enough free space is not left for shrinking
*
* %-EBUSY - Dirty or active segments exist in the region to be truncated
*/
int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
{
struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
struct buffer_head *header_bh;
struct nilfs_sufile_header *header;
struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
void *kaddr;
unsigned long nsegs, nrsvsegs;
int ret = 0;
down_write(&NILFS_MDT(sufile)->mi_sem);
nsegs = nilfs_sufile_get_nsegments(sufile);
if (nsegs == newnsegs)
goto out;
ret = -ENOSPC;
nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
goto out;
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out;
if (newnsegs > nsegs) {
sui->ncleansegs += newnsegs - nsegs;
} else /* newnsegs < nsegs */ {
ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
if (ret < 0)
goto out_header;
sui->ncleansegs -= nsegs - newnsegs;
}
kaddr = kmap_atomic(header_bh->b_page);
header = kaddr + bh_offset(header_bh);
header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
kunmap_atomic(kaddr);
mark_buffer_dirty(header_bh);
nilfs_mdt_mark_dirty(sufile);
nilfs_set_nsegments(nilfs, newnsegs);
out_header:
brelse(header_bh);
out:
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
* @buf: array of suinfo
* @sisz: byte size 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, void *buf,
unsigned sisz, size_t nsi)
{
struct buffer_head *su_bh;
struct nilfs_segment_usage *su;
struct nilfs_suinfo *si = buf;
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
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, 0, sisz * n);
si = (void *)si + sisz * n;
continue;
}
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
for (j = 0; j < n;
j++, su = (void *)su + susz, si = (void *)si + sisz) {
si->sui_lastmod = le64_to_cpu(su->su_lastmod);
si->sui_nblocks = le32_to_cpu(su->su_nblocks);
si->sui_flags = le32_to_cpu(su->su_flags) &
~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
if (nilfs_segment_is_active(nilfs, segnum + j))
si->sui_flags |=
(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
}
kunmap_atomic(kaddr);
brelse(su_bh);
}
ret = nsegs;
out:
up_read(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_read - read or get sufile inode
* @sb: super block instance
* @susize: size of a segment usage entry
* @raw_inode: on-disk sufile inode
* @inodep: buffer to store the inode
*/
int nilfs_sufile_read(struct super_block *sb, size_t susize,
struct nilfs_inode *raw_inode, struct inode **inodep)
{
struct inode *sufile;
struct nilfs_sufile_info *sui;
struct buffer_head *header_bh;
struct nilfs_sufile_header *header;
void *kaddr;
int err;
sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
if (unlikely(!sufile))
return -ENOMEM;
if (!(sufile->i_state & I_NEW))
goto out;
err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
if (err)
goto failed;
nilfs_mdt_set_entry_size(sufile, susize,
sizeof(struct nilfs_sufile_header));
err = nilfs_read_inode_common(sufile, raw_inode);
if (err)
goto failed;
err = nilfs_sufile_get_header_block(sufile, &header_bh);
if (err)
goto failed;
sui = NILFS_SUI(sufile);
kaddr = kmap_atomic(header_bh->b_page);
header = kaddr + bh_offset(header_bh);
sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
kunmap_atomic(kaddr);
brelse(header_bh);
sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
sui->allocmin = 0;
unlock_new_inode(sufile);
out:
*inodep = sufile;
return 0;
failed:
iget_failed(sufile);
return err;
}