/*
* 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 {
struct nilfs_mdt_info mi;
unsigned long ncleansegs;
};
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 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, KM_USER0);
header = kaddr + bh_offset(header_bh);
le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
kunmap_atomic(kaddr, KM_USER0);
nilfs_mdt_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_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;
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);
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 = kaddr + bh_offset(header_bh);
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 = 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, KM_USER0);
NILFS_SUI(sufile)->ncleansegs--;
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;
}
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, 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);
return;
}
nilfs_segment_usage_set_dirty(su);
kunmap_atomic(kaddr, KM_USER0);
nilfs_sufile_mod_counter(header_bh, -1, 1);
NILFS_SUI(sufile)->ncleansegs--;
nilfs_mdt_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, KM_USER0);
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, KM_USER0);
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, KM_USER0);
nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
NILFS_SUI(sufile)->ncleansegs -= clean;
nilfs_mdt_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, KM_USER0);
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, KM_USER0);
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, KM_USER0);
nilfs_mdt_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) {
nilfs_mdt_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, KM_USER0);
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, KM_USER0);
nilfs_mdt_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 = 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 = 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, KM_USER0);
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, 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);
return;
}
suclean = nilfs_segment_usage_clean(su);
nilfs_segment_usage_set_error(su);
kunmap_atomic(kaddr, KM_USER0);
if (suclean) {
nilfs_sufile_mod_counter(header_bh, -1, 0);
NILFS_SUI(sufile)->ncleansegs--;
}
nilfs_mdt_mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
}
/**
* 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 = 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, 0, sisz * n);
si = (void *)si + sisz * 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 = (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, KM_USER0);
brelse(su_bh);
}
ret = nsegs;
out:
up_read(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_read - read sufile inode
* @sufile: sufile inode
* @raw_inode: on-disk sufile inode
*/
int nilfs_sufile_read(struct inode *sufile, struct nilfs_inode *raw_inode)
{
struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
struct buffer_head *header_bh;
struct nilfs_sufile_header *header;
void *kaddr;
int ret;
ret = nilfs_read_inode_common(sufile, raw_inode);
if (ret < 0)
return ret;
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (!ret) {
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = kaddr + bh_offset(header_bh);
sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
kunmap_atomic(kaddr, KM_USER0);
brelse(header_bh);
}
return ret;
}
/**
* nilfs_sufile_new - create sufile
* @nilfs: nilfs object
* @susize: size of a segment usage entry
*/
struct inode *nilfs_sufile_new(struct the_nilfs *nilfs, size_t susize)
{
struct inode *sufile;
sufile = nilfs_mdt_new(nilfs, NULL, NILFS_SUFILE_INO,
sizeof(struct nilfs_sufile_info));
if (sufile)
nilfs_mdt_set_entry_size(sufile, susize,
sizeof(struct nilfs_sufile_header));
return sufile;
}
