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gerrit-public.fairphone.software / kernel / msm-4.9 / 5b09b507daaa882d888b6cd78ee89ba9caace44b / . / fs / nilfs2 / segment.c
blob: fb70ec3be20ea0899d34e98a4a48b9828b358052 [file] [log] [blame]
/*
* segment.c - NILFS segment constructor.
*
* Copyright (C) 2005-2008 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 Ryusuke Konishi <ryusuke@osrg.net>
*
*/
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/bio.h>
#include <linux/completion.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/crc32.h>
#include <linux/pagevec.h>
#include "nilfs.h"
#include "btnode.h"
#include "page.h"
#include "segment.h"
#include "sufile.h"
#include "cpfile.h"
#include "ifile.h"
#include "seglist.h"
#include "segbuf.h"
/*
* Segment constructor
*/
#define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
#define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments
appended in collection retry loop */
/* Construction mode */
enum {
SC_LSEG_SR = 1, /* Make a logical segment having a super root */
SC_LSEG_DSYNC, /* Flush data blocks of a given file and make
a logical segment without a super root */
SC_FLUSH_FILE, /* Flush data files, leads to segment writes without
creating a checkpoint */
SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without
a checkpoint */
};
/* Stage numbers of dirty block collection */
enum {
NILFS_ST_INIT = 0,
NILFS_ST_GC, /* Collecting dirty blocks for GC */
NILFS_ST_FILE,
NILFS_ST_IFILE,
NILFS_ST_CPFILE,
NILFS_ST_SUFILE,
NILFS_ST_DAT,
NILFS_ST_SR, /* Super root */
NILFS_ST_DSYNC, /* Data sync blocks */
NILFS_ST_DONE,
};
/* State flags of collection */
#define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
#define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
#define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED)
/* Operations depending on the construction mode and file type */
struct nilfs_sc_operations {
int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
struct inode *);
int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
struct inode *);
int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
struct inode *);
void (*write_data_binfo)(struct nilfs_sc_info *,
struct nilfs_segsum_pointer *,
union nilfs_binfo *);
void (*write_node_binfo)(struct nilfs_sc_info *,
struct nilfs_segsum_pointer *,
union nilfs_binfo *);
};
/*
* Other definitions
*/
static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
static void nilfs_dispose_list(struct nilfs_sb_info *, struct list_head *,
int);
#define nilfs_cnt32_gt(a, b) \
(typecheck(__u32, a) && typecheck(__u32, b) && \
((__s32)(b) - (__s32)(a) < 0))
#define nilfs_cnt32_ge(a, b) \
(typecheck(__u32, a) && typecheck(__u32, b) && \
((__s32)(a) - (__s32)(b) >= 0))
#define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
#define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
/*
* Transaction
*/
static struct kmem_cache *nilfs_transaction_cachep;
/**
* nilfs_init_transaction_cache - create a cache for nilfs_transaction_info
*
* nilfs_init_transaction_cache() creates a slab cache for the struct
* nilfs_transaction_info.
*
* Return Value: On success, it returns 0. On error, one of the following
* negative error code is returned.
*
* %-ENOMEM - Insufficient memory available.
*/
int nilfs_init_transaction_cache(void)
{
nilfs_transaction_cachep =
kmem_cache_create("nilfs2_transaction_cache",
sizeof(struct nilfs_transaction_info),
0, SLAB_RECLAIM_ACCOUNT, NULL);
return (nilfs_transaction_cachep == NULL) ? -ENOMEM : 0;
}
/**
* nilfs_detroy_transaction_cache - destroy the cache for transaction info
*
* nilfs_destroy_transaction_cache() frees the slab cache for the struct
* nilfs_transaction_info.
*/
void nilfs_destroy_transaction_cache(void)
{
kmem_cache_destroy(nilfs_transaction_cachep);
}
static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
{
struct nilfs_transaction_info *cur_ti = current->journal_info;
void *save = NULL;
if (cur_ti) {
if (cur_ti->ti_magic == NILFS_TI_MAGIC)
return ++cur_ti->ti_count;
else {
/*
* If journal_info field is occupied by other FS,
* it is saved and will be restored on
* nilfs_transaction_commit().
*/
printk(KERN_WARNING
"NILFS warning: journal info from a different "
"FS\n");
save = current->journal_info;
}
}
if (!ti) {
ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
if (!ti)
return -ENOMEM;
ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
} else {
ti->ti_flags = 0;
}
ti->ti_count = 0;
ti->ti_save = save;
ti->ti_magic = NILFS_TI_MAGIC;
current->journal_info = ti;
return 0;
}
/**
* nilfs_transaction_begin - start indivisible file operations.
* @sb: super block
* @ti: nilfs_transaction_info
* @vacancy_check: flags for vacancy rate checks
*
* nilfs_transaction_begin() acquires a reader/writer semaphore, called
* the segment semaphore, to make a segment construction and write tasks
* exclusive. The function is used with nilfs_transaction_commit() in pairs.
* The region enclosed by these two functions can be nested. To avoid a
* deadlock, the semaphore is only acquired or released in the outermost call.
*
* This function allocates a nilfs_transaction_info struct to keep context
* information on it. It is initialized and hooked onto the current task in
* the outermost call. If a pre-allocated struct is given to @ti, it is used
* instead; othewise a new struct is assigned from a slab.
*
* When @vacancy_check flag is set, this function will check the amount of
* free space, and will wait for the GC to reclaim disk space if low capacity.
*
* Return Value: On success, 0 is returned. On error, one of the following
* negative error code is returned.
*
* %-ENOMEM - Insufficient memory available.
*
* %-ENOSPC - No space left on device
*/
int nilfs_transaction_begin(struct super_block *sb,
struct nilfs_transaction_info *ti,
int vacancy_check)
{
struct nilfs_sb_info *sbi;
struct the_nilfs *nilfs;
int ret = nilfs_prepare_segment_lock(ti);
if (unlikely(ret < 0))
return ret;
if (ret > 0)
return 0;
sbi = NILFS_SB(sb);
nilfs = sbi->s_nilfs;
down_read(&nilfs->ns_segctor_sem);
if (vacancy_check && nilfs_near_disk_full(nilfs)) {
up_read(&nilfs->ns_segctor_sem);
ret = -ENOSPC;
goto failed;
}
return 0;
failed:
ti = current->journal_info;
current->journal_info = ti->ti_save;
if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
kmem_cache_free(nilfs_transaction_cachep, ti);
return ret;
}
/**
* nilfs_transaction_commit - commit indivisible file operations.
* @sb: super block
*
* nilfs_transaction_commit() releases the read semaphore which is
* acquired by nilfs_transaction_begin(). This is only performed
* in outermost call of this function. If a commit flag is set,
* nilfs_transaction_commit() sets a timer to start the segment
* constructor. If a sync flag is set, it starts construction
* directly.
*/
int nilfs_transaction_commit(struct super_block *sb)
{
struct nilfs_transaction_info *ti = current->journal_info;
struct nilfs_sb_info *sbi;
struct nilfs_sc_info *sci;
int err = 0;
BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
ti->ti_flags |= NILFS_TI_COMMIT;
if (ti->ti_count > 0) {
ti->ti_count--;
return 0;
}
sbi = NILFS_SB(sb);
sci = NILFS_SC(sbi);
if (sci != NULL) {
if (ti->ti_flags & NILFS_TI_COMMIT)
nilfs_segctor_start_timer(sci);
if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) >
sci->sc_watermark)
nilfs_segctor_do_flush(sci, 0);
}
up_read(&sbi->s_nilfs->ns_segctor_sem);
current->journal_info = ti->ti_save;
if (ti->ti_flags & NILFS_TI_SYNC)
err = nilfs_construct_segment(sb);
if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
kmem_cache_free(nilfs_transaction_cachep, ti);
return err;
}
void nilfs_transaction_abort(struct super_block *sb)
{
struct nilfs_transaction_info *ti = current->journal_info;
BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
if (ti->ti_count > 0) {
ti->ti_count--;
return;
}
up_read(&NILFS_SB(sb)->s_nilfs->ns_segctor_sem);
current->journal_info = ti->ti_save;
if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
kmem_cache_free(nilfs_transaction_cachep, ti);
}
void nilfs_relax_pressure_in_lock(struct super_block *sb)
{
struct nilfs_sb_info *sbi = NILFS_SB(sb);
struct nilfs_sc_info *sci = NILFS_SC(sbi);
struct the_nilfs *nilfs = sbi->s_nilfs;
if (!sci || !sci->sc_flush_request)
return;
set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
up_read(&nilfs->ns_segctor_sem);
down_write(&nilfs->ns_segctor_sem);
if (sci->sc_flush_request &&
test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
struct nilfs_transaction_info *ti = current->journal_info;
ti->ti_flags |= NILFS_TI_WRITER;
nilfs_segctor_do_immediate_flush(sci);
ti->ti_flags &= ~NILFS_TI_WRITER;
}
downgrade_write(&nilfs->ns_segctor_sem);
}
static void nilfs_transaction_lock(struct nilfs_sb_info *sbi,
struct nilfs_transaction_info *ti,
int gcflag)
{
struct nilfs_transaction_info *cur_ti = current->journal_info;
WARN_ON(cur_ti);
ti->ti_flags = NILFS_TI_WRITER;
ti->ti_count = 0;
ti->ti_save = cur_ti;
ti->ti_magic = NILFS_TI_MAGIC;
INIT_LIST_HEAD(&ti->ti_garbage);
current->journal_info = ti;
for (;;) {
down_write(&sbi->s_nilfs->ns_segctor_sem);
if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags))
break;
nilfs_segctor_do_immediate_flush(NILFS_SC(sbi));
up_write(&sbi->s_nilfs->ns_segctor_sem);
yield();
}
if (gcflag)
ti->ti_flags |= NILFS_TI_GC;
}
static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi)
{
struct nilfs_transaction_info *ti = current->journal_info;
BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
BUG_ON(ti->ti_count > 0);
up_write(&sbi->s_nilfs->ns_segctor_sem);
current->journal_info = ti->ti_save;
if (!list_empty(&ti->ti_garbage))
nilfs_dispose_list(sbi, &ti->ti_garbage, 0);
}
static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
struct nilfs_segsum_pointer *ssp,
unsigned bytes)
{
struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
unsigned blocksize = sci->sc_super->s_blocksize;
void *p;
if (unlikely(ssp->offset + bytes > blocksize)) {
ssp->offset = 0;
BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
&segbuf->sb_segsum_buffers));
ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
}
p = ssp->bh->b_data + ssp->offset;
ssp->offset += bytes;
return p;
}
/**
* nilfs_segctor_reset_segment_buffer - reset the current segment buffer
* @sci: nilfs_sc_info
*/
static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
{
struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
struct buffer_head *sumbh;
unsigned sumbytes;
unsigned flags = 0;
int err;
if (nilfs_doing_gc())
flags = NILFS_SS_GC;
err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime);
if (unlikely(err))
return err;
sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
sumbytes = segbuf->sb_sum.sumbytes;
sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
return 0;
}
static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
{
sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
return -E2BIG; /* The current segment is filled up
(internal code) */
sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
return nilfs_segctor_reset_segment_buffer(sci);
}
static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
{
struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
int err;
if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
err = nilfs_segctor_feed_segment(sci);
if (err)
return err;
segbuf = sci->sc_curseg;
}
err = nilfs_segbuf_extend_payload(segbuf, &sci->sc_super_root);
if (likely(!err))
segbuf->sb_sum.flags |= NILFS_SS_SR;
return err;
}
/*
* Functions for making segment summary and payloads
*/
static int nilfs_segctor_segsum_block_required(
struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
unsigned binfo_size)
{
unsigned blocksize = sci->sc_super->s_blocksize;
/* Size of finfo and binfo is enough small against blocksize */
return ssp->offset + binfo_size +
(!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
blocksize;
}
static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
struct inode *inode)
{
sci->sc_curseg->sb_sum.nfinfo++;
sci->sc_binfo_ptr = sci->sc_finfo_ptr;
nilfs_segctor_map_segsum_entry(
sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
if (inode->i_sb && !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
/* skip finfo */
}
static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
struct inode *inode)
{
struct nilfs_finfo *finfo;
struct nilfs_inode_info *ii;
struct nilfs_segment_buffer *segbuf;
if (sci->sc_blk_cnt == 0)
return;
ii = NILFS_I(inode);
finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
sizeof(*finfo));
finfo->fi_ino = cpu_to_le64(inode->i_ino);
finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
finfo->fi_cno = cpu_to_le64(ii->i_cno);
segbuf = sci->sc_curseg;
segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
sci->sc_finfo_ptr = sci->sc_binfo_ptr;
sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
}
static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
struct buffer_head *bh,
struct inode *inode,
unsigned binfo_size)
{
struct nilfs_segment_buffer *segbuf;
int required, err = 0;
retry:
segbuf = sci->sc_curseg;
required = nilfs_segctor_segsum_block_required(
sci, &sci->sc_binfo_ptr, binfo_size);
if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
nilfs_segctor_end_finfo(sci, inode);
err = nilfs_segctor_feed_segment(sci);
if (err)
return err;
goto retry;
}
if (unlikely(required)) {
err = nilfs_segbuf_extend_segsum(segbuf);
if (unlikely(err))
goto failed;
}
if (sci->sc_blk_cnt == 0)
nilfs_segctor_begin_finfo(sci, inode);
nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
/* Substitution to vblocknr is delayed until update_blocknr() */
nilfs_segbuf_add_file_buffer(segbuf, bh);
sci->sc_blk_cnt++;
failed:
return err;
}
static int nilfs_handle_bmap_error(int err, const char *fname,
struct inode *inode, struct super_block *sb)
{
if (err == -EINVAL) {
nilfs_error(sb, fname, "broken bmap (inode=%lu)\n",
inode->i_ino);
err = -EIO;
}
return err;
}
/*
* Callback functions that enumerate, mark, and collect dirty blocks
*/
static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
struct buffer_head *bh, struct inode *inode)
{
int err;
err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
if (unlikely(err < 0))
return nilfs_handle_bmap_error(err, __func__, inode,
sci->sc_super);
err = nilfs_segctor_add_file_block(sci, bh, inode,
sizeof(struct nilfs_binfo_v));
if (!err)
sci->sc_datablk_cnt++;
return err;
}
static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
struct buffer_head *bh,
struct inode *inode)
{
int err;
err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
if (unlikely(err < 0))
return nilfs_handle_bmap_error(err, __func__, inode,
sci->sc_super);
return 0;
}
static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
struct buffer_head *bh,
struct inode *inode)
{
WARN_ON(!buffer_dirty(bh));
return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
}
static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
struct nilfs_segsum_pointer *ssp,
union nilfs_binfo *binfo)
{
struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
sci, ssp, sizeof(*binfo_v));
*binfo_v = binfo->bi_v;
}
static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
struct nilfs_segsum_pointer *ssp,
union nilfs_binfo *binfo)
{
__le64 *vblocknr = nilfs_segctor_map_segsum_entry(
sci, ssp, sizeof(*vblocknr));
*vblocknr = binfo->bi_v.bi_vblocknr;
}
struct nilfs_sc_operations nilfs_sc_file_ops = {
.collect_data = nilfs_collect_file_data,
.collect_node = nilfs_collect_file_node,
.collect_bmap = nilfs_collect_file_bmap,
.write_data_binfo = nilfs_write_file_data_binfo,
.write_node_binfo = nilfs_write_file_node_binfo,
};
static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
struct buffer_head *bh, struct inode *inode)
{
int err;
err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
if (unlikely(err < 0))
return nilfs_handle_bmap_error(err, __func__, inode,
sci->sc_super);
err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
if (!err)
sci->sc_datablk_cnt++;
return err;
}
static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
struct buffer_head *bh, struct inode *inode)
{
WARN_ON(!buffer_dirty(bh));
return nilfs_segctor_add_file_block(sci, bh, inode,
sizeof(struct nilfs_binfo_dat));
}
static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
struct nilfs_segsum_pointer *ssp,
union nilfs_binfo *binfo)
{
__le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
sizeof(*blkoff));
*blkoff = binfo->bi_dat.bi_blkoff;
}
static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
struct nilfs_segsum_pointer *ssp,
union nilfs_binfo *binfo)
{
struct nilfs_binfo_dat *binfo_dat =
nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
*binfo_dat = binfo->bi_dat;
}
struct nilfs_sc_operations nilfs_sc_dat_ops = {
.collect_data = nilfs_collect_dat_data,
.collect_node = nilfs_collect_file_node,
.collect_bmap = nilfs_collect_dat_bmap,
.write_data_binfo = nilfs_write_dat_data_binfo,
.write_node_binfo = nilfs_write_dat_node_binfo,
};
struct nilfs_sc_operations nilfs_sc_dsync_ops = {
.collect_data = nilfs_collect_file_data,
.collect_node = NULL,
.collect_bmap = NULL,
.write_data_binfo = nilfs_write_file_data_binfo,
.write_node_binfo = NULL,
};
static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
struct list_head *listp,
size_t nlimit,
loff_t start, loff_t end)
{
struct address_space *mapping = inode->i_mapping;
struct pagevec pvec;
pgoff_t index = 0, last = ULONG_MAX;
size_t ndirties = 0;
int i;
if (unlikely(start != 0 || end != LLONG_MAX)) {
/*
* A valid range is given for sync-ing data pages. The
* range is rounded to per-page; extra dirty buffers
* may be included if blocksize < pagesize.
*/
index = start >> PAGE_SHIFT;
last = end >> PAGE_SHIFT;
}
pagevec_init(&pvec, 0);
repeat:
if (unlikely(index > last) ||
!pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
min_t(pgoff_t, last - index,
PAGEVEC_SIZE - 1) + 1))
return ndirties;
for (i = 0; i < pagevec_count(&pvec); i++) {
struct buffer_head *bh, *head;
struct page *page = pvec.pages[i];
if (unlikely(page->index > last))
break;
if (mapping->host) {
lock_page(page);
if (!page_has_buffers(page))
create_empty_buffers(page,
1 << inode->i_blkbits, 0);
unlock_page(page);
}
bh = head = page_buffers(page);
do {
if (!buffer_dirty(bh))
continue;
get_bh(bh);
list_add_tail(&bh->b_assoc_buffers, listp);
ndirties++;
if (unlikely(ndirties >= nlimit)) {
pagevec_release(&pvec);
cond_resched();
return ndirties;
}
} while (bh = bh->b_this_page, bh != head);
}
pagevec_release(&pvec);
cond_resched();
goto repeat;
}
static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
struct list_head *listp)
{
struct nilfs_inode_info *ii = NILFS_I(inode);
struct address_space *mapping = &ii->i_btnode_cache;
struct pagevec pvec;
struct buffer_head *bh, *head;
unsigned int i;
pgoff_t index = 0;
pagevec_init(&pvec, 0);
while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
PAGEVEC_SIZE)) {
for (i = 0; i < pagevec_count(&pvec); i++) {
bh = head = page_buffers(pvec.pages[i]);
do {
if (buffer_dirty(bh)) {
get_bh(bh);
list_add_tail(&bh->b_assoc_buffers,
listp);
}
bh = bh->b_this_page;
} while (bh != head);
}
pagevec_release(&pvec);
cond_resched();
}
}
static void nilfs_dispose_list(struct nilfs_sb_info *sbi,
struct list_head *head, int force)
{
struct nilfs_inode_info *ii, *n;
struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
unsigned nv = 0;
while (!list_empty(head)) {
spin_lock(&sbi->s_inode_lock);
list_for_each_entry_safe(ii, n, head, i_dirty) {
list_del_init(&ii->i_dirty);
if (force) {
if (unlikely(ii->i_bh)) {
brelse(ii->i_bh);
ii->i_bh = NULL;
}
} else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
set_bit(NILFS_I_QUEUED, &ii->i_state);
list_add_tail(&ii->i_dirty,
&sbi->s_dirty_files);
continue;
}
ivec[nv++] = ii;
if (nv == SC_N_INODEVEC)
break;
}
spin_unlock(&sbi->s_inode_lock);
for (pii = ivec; nv > 0; pii++, nv--)
iput(&(*pii)->vfs_inode);
}
}
static int nilfs_test_metadata_dirty(struct nilfs_sb_info *sbi)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
int ret = 0;
if (nilfs_mdt_fetch_dirty(sbi->s_ifile))
ret++;
if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
ret++;
if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
ret++;
if (ret || nilfs_doing_gc())
if (nilfs_mdt_fetch_dirty(nilfs_dat_inode(nilfs)))
ret++;
return ret;
}
static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
{
return list_empty(&sci->sc_dirty_files) &&
!test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
list_empty(&sci->sc_cleaning_segments) &&
(!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
}
static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
int ret = 0;
if (nilfs_test_metadata_dirty(sbi))
set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
spin_lock(&sbi->s_inode_lock);
if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci))
ret++;
spin_unlock(&sbi->s_inode_lock);
return ret;
}
static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct the_nilfs *nilfs = sbi->s_nilfs;
nilfs_mdt_clear_dirty(sbi->s_ifile);
nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
nilfs_mdt_clear_dirty(nilfs->ns_sufile);
nilfs_mdt_clear_dirty(nilfs_dat_inode(nilfs));
}
static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
{
struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
struct buffer_head *bh_cp;
struct nilfs_checkpoint *raw_cp;
int err;
/* XXX: this interface will be changed */
err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
&raw_cp, &bh_cp);
if (likely(!err)) {
/* The following code is duplicated with cpfile. But, it is
needed to collect the checkpoint even if it was not newly
created */
nilfs_mdt_mark_buffer_dirty(bh_cp);
nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
nilfs_cpfile_put_checkpoint(
nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
} else
WARN_ON(err == -EINVAL || err == -ENOENT);
return err;
}
static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct the_nilfs *nilfs = sbi->s_nilfs;
struct buffer_head *bh_cp;
struct nilfs_checkpoint *raw_cp;
int err;
err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
&raw_cp, &bh_cp);
if (unlikely(err)) {
WARN_ON(err == -EINVAL || err == -ENOENT);
goto failed_ibh;
}
raw_cp->cp_snapshot_list.ssl_next = 0;
raw_cp->cp_snapshot_list.ssl_prev = 0;
raw_cp->cp_inodes_count =
cpu_to_le64(atomic_read(&sbi->s_inodes_count));
raw_cp->cp_blocks_count =
cpu_to_le64(atomic_read(&sbi->s_blocks_count));
raw_cp->cp_nblk_inc =
cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
nilfs_checkpoint_clear_minor(raw_cp);
else
nilfs_checkpoint_set_minor(raw_cp);
nilfs_write_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode, 1);
nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
return 0;
failed_ibh:
return err;
}
static void nilfs_fill_in_file_bmap(struct inode *ifile,
struct nilfs_inode_info *ii)
{
struct buffer_head *ibh;
struct nilfs_inode *raw_inode;
if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
ibh = ii->i_bh;
BUG_ON(!ibh);
raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
ibh);
nilfs_bmap_write(ii->i_bmap, raw_inode);
nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
}
}
static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci,
struct inode *ifile)
{
struct nilfs_inode_info *ii;
list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
nilfs_fill_in_file_bmap(ifile, ii);
set_bit(NILFS_I_COLLECTED, &ii->i_state);
}
}
/*
* CRC calculation routines
*/
static void nilfs_fill_in_super_root_crc(struct buffer_head *bh_sr, u32 seed)
{
struct nilfs_super_root *raw_sr =
(struct nilfs_super_root *)bh_sr->b_data;
u32 crc;
crc = crc32_le(seed,
(unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
NILFS_SR_BYTES - sizeof(raw_sr->sr_sum));
raw_sr->sr_sum = cpu_to_le32(crc);
}
static void nilfs_segctor_fill_in_checksums(struct nilfs_sc_info *sci,
u32 seed)
{
struct nilfs_segment_buffer *segbuf;
if (sci->sc_super_root)
nilfs_fill_in_super_root_crc(sci->sc_super_root, seed);
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
nilfs_segbuf_fill_in_data_crc(segbuf, seed);
}
}
static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs)
{
struct buffer_head *bh_sr = sci->sc_super_root;
struct nilfs_super_root *raw_sr =
(struct nilfs_super_root *)bh_sr->b_data;
unsigned isz = nilfs->ns_inode_size;
raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
raw_sr->sr_nongc_ctime
= cpu_to_le64(nilfs_doing_gc() ?
nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
raw_sr->sr_flags = 0;
nilfs_mdt_write_inode_direct(
nilfs_dat_inode(nilfs), bh_sr, NILFS_SR_DAT_OFFSET(isz));
nilfs_mdt_write_inode_direct(
nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(isz));
nilfs_mdt_write_inode_direct(
nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(isz));
}
static void nilfs_redirty_inodes(struct list_head *head)
{
struct nilfs_inode_info *ii;
list_for_each_entry(ii, head, i_dirty) {
if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
clear_bit(NILFS_I_COLLECTED, &ii->i_state);
}
}
static void nilfs_drop_collected_inodes(struct list_head *head)
{
struct nilfs_inode_info *ii;
list_for_each_entry(ii, head, i_dirty) {
if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
continue;
clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
set_bit(NILFS_I_UPDATED, &ii->i_state);
}
}
static void nilfs_segctor_cancel_free_segments(struct nilfs_sc_info *sci,
struct inode *sufile)
{
struct list_head *head = &sci->sc_cleaning_segments;
struct nilfs_segment_entry *ent;
int err;
list_for_each_entry(ent, head, list) {
if (!(ent->flags & NILFS_SLH_FREED))
break;
err = nilfs_sufile_cancel_free(sufile, ent->segnum);
WARN_ON(err); /* do not happen */
ent->flags &= ~NILFS_SLH_FREED;
}
}
static int nilfs_segctor_prepare_free_segments(struct nilfs_sc_info *sci,
struct inode *sufile)
{
struct list_head *head = &sci->sc_cleaning_segments;
struct nilfs_segment_entry *ent;
int err;
list_for_each_entry(ent, head, list) {
err = nilfs_sufile_free(sufile, ent->segnum);
if (unlikely(err))
return err;
ent->flags |= NILFS_SLH_FREED;
}
return 0;
}
static void nilfs_segctor_commit_free_segments(struct nilfs_sc_info *sci)
{
nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
}
static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
struct inode *inode,
struct list_head *listp,
int (*collect)(struct nilfs_sc_info *,
struct buffer_head *,
struct inode *))
{
struct buffer_head *bh, *n;
int err = 0;
if (collect) {
list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
list_del_init(&bh->b_assoc_buffers);
err = collect(sci, bh, inode);
brelse(bh);
if (unlikely(err))
goto dispose_buffers;
}
return 0;
}
dispose_buffers:
while (!list_empty(listp)) {
bh = list_entry(listp->next, struct buffer_head,
b_assoc_buffers);
list_del_init(&bh->b_assoc_buffers);
brelse(bh);
}
return err;
}
static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
{
/* Remaining number of blocks within segment buffer */
return sci->sc_segbuf_nblocks -
(sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
}
static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
struct inode *inode,
struct nilfs_sc_operations *sc_ops)
{
LIST_HEAD(data_buffers);
LIST_HEAD(node_buffers);
int err;
if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
size_t n, rest = nilfs_segctor_buffer_rest(sci);
n = nilfs_lookup_dirty_data_buffers(
inode, &data_buffers, rest + 1, 0, LLONG_MAX);
if (n > rest) {
err = nilfs_segctor_apply_buffers(
sci, inode, &data_buffers,
sc_ops->collect_data);
BUG_ON(!err); /* always receive -E2BIG or true error */
goto break_or_fail;
}
}
nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
err = nilfs_segctor_apply_buffers(
sci, inode, &data_buffers, sc_ops->collect_data);
if (unlikely(err)) {
/* dispose node list */
nilfs_segctor_apply_buffers(
sci, inode, &node_buffers, NULL);
goto break_or_fail;
}
sci->sc_stage.flags |= NILFS_CF_NODE;
}
/* Collect node */
err = nilfs_segctor_apply_buffers(
sci, inode, &node_buffers, sc_ops->collect_node);
if (unlikely(err))
goto break_or_fail;
nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
err = nilfs_segctor_apply_buffers(
sci, inode, &node_buffers, sc_ops->collect_bmap);
if (unlikely(err))
goto break_or_fail;
nilfs_segctor_end_finfo(sci, inode);
sci->sc_stage.flags &= ~NILFS_CF_NODE;
break_or_fail:
return err;
}
static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
struct inode *inode)
{
LIST_HEAD(data_buffers);
size_t n, rest = nilfs_segctor_buffer_rest(sci);
int err;
n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
sci->sc_dsync_start,
sci->sc_dsync_end);
err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
nilfs_collect_file_data);
if (!err) {
nilfs_segctor_end_finfo(sci, inode);
BUG_ON(n > rest);
/* always receive -E2BIG or true error if n > rest */
}
return err;
}
static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct the_nilfs *nilfs = sbi->s_nilfs;
struct list_head *head;
struct nilfs_inode_info *ii;
int err = 0;
switch (sci->sc_stage.scnt) {
case NILFS_ST_INIT:
/* Pre-processes */
sci->sc_stage.flags = 0;
if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
sci->sc_nblk_inc = 0;
sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
if (mode == SC_LSEG_DSYNC) {
sci->sc_stage.scnt = NILFS_ST_DSYNC;
goto dsync_mode;
}
}
sci->sc_stage.dirty_file_ptr = NULL;
sci->sc_stage.gc_inode_ptr = NULL;
if (mode == SC_FLUSH_DAT) {
sci->sc_stage.scnt = NILFS_ST_DAT;
goto dat_stage;
}
sci->sc_stage.scnt++; /* Fall through */
case NILFS_ST_GC:
if (nilfs_doing_gc()) {
head = &sci->sc_gc_inodes;
ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
head, i_dirty);
list_for_each_entry_continue(ii, head, i_dirty) {
err = nilfs_segctor_scan_file(
sci, &ii->vfs_inode,
&nilfs_sc_file_ops);
if (unlikely(err)) {
sci->sc_stage.gc_inode_ptr = list_entry(
ii->i_dirty.prev,
struct nilfs_inode_info,
i_dirty);
goto break_or_fail;
}
set_bit(NILFS_I_COLLECTED, &ii->i_state);
}
sci->sc_stage.gc_inode_ptr = NULL;
}
sci->sc_stage.scnt++; /* Fall through */
case NILFS_ST_FILE:
head = &sci->sc_dirty_files;
ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
i_dirty);
list_for_each_entry_continue(ii, head, i_dirty) {
clear_bit(NILFS_I_DIRTY, &ii->i_state);
err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
&nilfs_sc_file_ops);
if (unlikely(err)) {
sci->sc_stage.dirty_file_ptr =
list_entry(ii->i_dirty.prev,
struct nilfs_inode_info,
i_dirty);
goto break_or_fail;
}
/* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
/* XXX: required ? */
}
sci->sc_stage.dirty_file_ptr = NULL;
if (mode == SC_FLUSH_FILE) {
sci->sc_stage.scnt = NILFS_ST_DONE;
return 0;
}
sci->sc_stage.scnt++;
sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
/* Fall through */
case NILFS_ST_IFILE:
err = nilfs_segctor_scan_file(sci, sbi->s_ifile,
&nilfs_sc_file_ops);
if (unlikely(err))
break;
sci->sc_stage.scnt++;
/* Creating a checkpoint */
err = nilfs_segctor_create_checkpoint(sci);
if (unlikely(err))
break;
/* Fall through */
case NILFS_ST_CPFILE:
err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
&nilfs_sc_file_ops);
if (unlikely(err))
break;
sci->sc_stage.scnt++; /* Fall through */
case NILFS_ST_SUFILE:
err = nilfs_segctor_prepare_free_segments(sci,
nilfs->ns_sufile);
if (unlikely(err))
break;
err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
&nilfs_sc_file_ops);
if (unlikely(err))
break;
sci->sc_stage.scnt++; /* Fall through */
case NILFS_ST_DAT:
dat_stage:
err = nilfs_segctor_scan_file(sci, nilfs_dat_inode(nilfs),
&nilfs_sc_dat_ops);
if (unlikely(err))
break;
if (mode == SC_FLUSH_DAT) {
sci->sc_stage.scnt = NILFS_ST_DONE;
return 0;
}
sci->sc_stage.scnt++; /* Fall through */
case NILFS_ST_SR:
if (mode == SC_LSEG_SR) {
/* Appending a super root */
err = nilfs_segctor_add_super_root(sci);
if (unlikely(err))
break;
}
/* End of a logical segment */
sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
sci->sc_stage.scnt = NILFS_ST_DONE;
return 0;
case NILFS_ST_DSYNC:
dsync_mode:
sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
ii = sci->sc_dsync_inode;
if (!test_bit(NILFS_I_BUSY, &ii->i_state))
break;
err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
if (unlikely(err))
break;
sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
sci->sc_stage.scnt = NILFS_ST_DONE;
return 0;
case NILFS_ST_DONE:
return 0;
default:
BUG();
}
break_or_fail:
return err;
}
static int nilfs_touch_segusage(struct inode *sufile, __u64 segnum)
{
struct buffer_head *bh_su;
struct nilfs_segment_usage *raw_su;
int err;
err = nilfs_sufile_get_segment_usage(sufile, segnum, &raw_su, &bh_su);
if (unlikely(err))
return err;
nilfs_mdt_mark_buffer_dirty(bh_su);
nilfs_mdt_mark_dirty(sufile);
nilfs_sufile_put_segment_usage(sufile, segnum, bh_su);
return 0;
}
static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs)
{
struct nilfs_segment_buffer *segbuf, *n;
__u64 nextnum;
int err;
if (list_empty(&sci->sc_segbufs)) {
segbuf = nilfs_segbuf_new(sci->sc_super);
if (unlikely(!segbuf))
return -ENOMEM;
list_add(&segbuf->sb_list, &sci->sc_segbufs);
} else
segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
nilfs_segbuf_map(segbuf, nilfs->ns_segnum, nilfs->ns_pseg_offset,
nilfs);
if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
nilfs_shift_to_next_segment(nilfs);
nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
}
sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
err = nilfs_touch_segusage(nilfs->ns_sufile, segbuf->sb_segnum);
if (unlikely(err))
return err;
if (nilfs->ns_segnum == nilfs->ns_nextnum) {
/* Start from the head of a new full segment */
err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
if (unlikely(err))
return err;
} else
nextnum = nilfs->ns_nextnum;
segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
/* truncating segment buffers */
list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
sb_list) {
list_del_init(&segbuf->sb_list);
nilfs_segbuf_free(segbuf);
}
return 0;
}
static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs, int nadd)
{
struct nilfs_segment_buffer *segbuf, *prev, *n;
struct inode *sufile = nilfs->ns_sufile;
__u64 nextnextnum;
LIST_HEAD(list);
int err, ret, i;
prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
/*
* Since the segment specified with nextnum might be allocated during
* the previous construction, the buffer including its segusage may
* not be dirty. The following call ensures that the buffer is dirty
* and will pin the buffer on memory until the sufile is written.
*/
err = nilfs_touch_segusage(sufile, prev->sb_nextnum);
if (unlikely(err))
return err;
for (i = 0; i < nadd; i++) {
/* extend segment info */
err = -ENOMEM;
segbuf = nilfs_segbuf_new(sci->sc_super);
if (unlikely(!segbuf))
goto failed;
/* map this buffer to region of segment on-disk */
nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
/* allocate the next next full segment */
err = nilfs_sufile_alloc(sufile, &nextnextnum);
if (unlikely(err))
goto failed_segbuf;
segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
list_add_tail(&segbuf->sb_list, &list);
prev = segbuf;
}
list_splice(&list, sci->sc_segbufs.prev);
return 0;
failed_segbuf:
nilfs_segbuf_free(segbuf);
failed:
list_for_each_entry_safe(segbuf, n, &list, sb_list) {
ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
WARN_ON(ret); /* never fails */
list_del_init(&segbuf->sb_list);
nilfs_segbuf_free(segbuf);
}
return err;
}
static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs)
{
struct nilfs_segment_buffer *segbuf;
int ret, done = 0;
segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
WARN_ON(ret); /* never fails */
}
if (segbuf->sb_io_error) {
/* Case 1: The first segment failed */
if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
/* Case 1a: Partial segment appended into an existing
segment */
nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
segbuf->sb_fseg_end);
else /* Case 1b: New full segment */
set_nilfs_discontinued(nilfs);
done++;
}
list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
WARN_ON(ret); /* never fails */
if (!done && segbuf->sb_io_error) {
if (segbuf->sb_segnum != nilfs->ns_nextnum)
/* Case 2: extended segment (!= next) failed */
nilfs_sufile_set_error(nilfs->ns_sufile,
segbuf->sb_segnum);
done++;
}
}
}
static void nilfs_segctor_clear_segment_buffers(struct nilfs_sc_info *sci)
{
struct nilfs_segment_buffer *segbuf;
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list)
nilfs_segbuf_clear(segbuf);
sci->sc_super_root = NULL;
}
static void nilfs_segctor_destroy_segment_buffers(struct nilfs_sc_info *sci)
{
struct nilfs_segment_buffer *segbuf;
while (!list_empty(&sci->sc_segbufs)) {
segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
list_del_init(&segbuf->sb_list);
nilfs_segbuf_free(segbuf);
}
/* sci->sc_curseg = NULL; */
}
static void nilfs_segctor_end_construction(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs, int err)
{
if (unlikely(err)) {
nilfs_segctor_free_incomplete_segments(sci, nilfs);
nilfs_segctor_cancel_free_segments(sci, nilfs->ns_sufile);
}
nilfs_segctor_clear_segment_buffers(sci);
}
static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
struct inode *sufile)
{
struct nilfs_segment_buffer *segbuf;
struct buffer_head *bh_su;
struct nilfs_segment_usage *raw_su;
unsigned long live_blocks;
int ret;
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
&raw_su, &bh_su);
WARN_ON(ret); /* always succeed because bh_su is dirty */
live_blocks = segbuf->sb_sum.nblocks +
(segbuf->sb_pseg_start - segbuf->sb_fseg_start);
raw_su->su_lastmod = cpu_to_le64(sci->sc_seg_ctime);
raw_su->su_nblocks = cpu_to_le32(live_blocks);
nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
bh_su);
}
}
static void nilfs_segctor_cancel_segusage(struct nilfs_sc_info *sci,
struct inode *sufile)
{
struct nilfs_segment_buffer *segbuf;
struct buffer_head *bh_su;
struct nilfs_segment_usage *raw_su;
int ret;
segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
&raw_su, &bh_su);
WARN_ON(ret); /* always succeed because bh_su is dirty */
raw_su->su_nblocks = cpu_to_le32(segbuf->sb_pseg_start -
segbuf->sb_fseg_start);
nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum, bh_su);
list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
&raw_su, &bh_su);
WARN_ON(ret); /* always succeed */
raw_su->su_nblocks = 0;
nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
bh_su);
}
}
static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
struct nilfs_segment_buffer *last,
struct inode *sufile)
{
struct nilfs_segment_buffer *segbuf = last, *n;
int ret;
list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
sb_list) {
list_del_init(&segbuf->sb_list);
sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
WARN_ON(ret);
nilfs_segbuf_free(segbuf);
}
}
static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs, int mode)
{
struct nilfs_cstage prev_stage = sci->sc_stage;
int err, nadd = 1;
/* Collection retry loop */
for (;;) {
sci->sc_super_root = NULL;
sci->sc_nblk_this_inc = 0;
sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
err = nilfs_segctor_reset_segment_buffer(sci);
if (unlikely(err))
goto failed;
err = nilfs_segctor_collect_blocks(sci, mode);
sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
if (!err)
break;
if (unlikely(err != -E2BIG))
goto failed;
/* The current segment is filled up */
if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
break;
nilfs_segctor_cancel_free_segments(sci, nilfs->ns_sufile);
nilfs_segctor_clear_segment_buffers(sci);
err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
if (unlikely(err))
return err;
nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
sci->sc_stage = prev_stage;
}
nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
return 0;
failed:
return err;
}
static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
struct buffer_head *new_bh)
{
BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
/* The caller must release old_bh */
}
static int
nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
struct nilfs_segment_buffer *segbuf,
int mode)
{
struct inode *inode = NULL;
sector_t blocknr;
unsigned long nfinfo = segbuf->sb_sum.nfinfo;
unsigned long nblocks = 0, ndatablk = 0;
struct nilfs_sc_operations *sc_op = NULL;
struct nilfs_segsum_pointer ssp;
struct nilfs_finfo *finfo = NULL;
union nilfs_binfo binfo;
struct buffer_head *bh, *bh_org;
ino_t ino = 0;
int err = 0;
if (!nfinfo)
goto out;
blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
ssp.offset = sizeof(struct nilfs_segment_summary);
list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
if (bh == sci->sc_super_root)
break;
if (!finfo) {
finfo = nilfs_segctor_map_segsum_entry(
sci, &ssp, sizeof(*finfo));
ino = le64_to_cpu(finfo->fi_ino);
nblocks = le32_to_cpu(finfo->fi_nblocks);
ndatablk = le32_to_cpu(finfo->fi_ndatablk);
if (buffer_nilfs_node(bh))
inode = NILFS_BTNC_I(bh->b_page->mapping);
else
inode = NILFS_AS_I(bh->b_page->mapping);
if (mode == SC_LSEG_DSYNC)
sc_op = &nilfs_sc_dsync_ops;
else if (ino == NILFS_DAT_INO)
sc_op = &nilfs_sc_dat_ops;
else /* file blocks */
sc_op = &nilfs_sc_file_ops;
}
bh_org = bh;
get_bh(bh_org);
err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
&binfo);
if (bh != bh_org)
nilfs_list_replace_buffer(bh_org, bh);
brelse(bh_org);
if (unlikely(err))
goto failed_bmap;
if (ndatablk > 0)
sc_op->write_data_binfo(sci, &ssp, &binfo);
else
sc_op->write_node_binfo(sci, &ssp, &binfo);
blocknr++;
if (--nblocks == 0) {
finfo = NULL;
if (--nfinfo == 0)
break;
} else if (ndatablk > 0)
ndatablk--;
}
out:
return 0;
failed_bmap:
err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
return err;
}
static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
{
struct nilfs_segment_buffer *segbuf;
int err;
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
if (unlikely(err))
return err;
nilfs_segbuf_fill_in_segsum(segbuf);
}
return 0;
}
static int
nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
{
struct page *clone_page;
struct buffer_head *bh, *head, *bh2;
void *kaddr;
bh = head = page_buffers(page);
clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
if (unlikely(!clone_page))
return -ENOMEM;
bh2 = page_buffers(clone_page);
kaddr = kmap_atomic(page, KM_USER0);
do {
if (list_empty(&bh->b_assoc_buffers))
continue;
get_bh(bh2);
page_cache_get(clone_page); /* for each bh */
memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
bh2->b_blocknr = bh->b_blocknr;
list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
list_add_tail(&bh->b_assoc_buffers, out);
} while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
kunmap_atomic(kaddr, KM_USER0);
if (!TestSetPageWriteback(clone_page))
inc_zone_page_state(clone_page, NR_WRITEBACK);
unlock_page(clone_page);
return 0;
}
static int nilfs_test_page_to_be_frozen(struct page *page)
{
struct address_space *mapping = page->mapping;
if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
return 0;
if (page_mapped(page)) {
ClearPageChecked(page);
return 1;
}
return PageChecked(page);
}
static int nilfs_begin_page_io(struct page *page, struct list_head *out)
{
if (!page || PageWriteback(page))
/* For split b-tree node pages, this function may be called
twice. We ignore the 2nd or later calls by this check. */
return 0;
lock_page(page);
clear_page_dirty_for_io(page);
set_page_writeback(page);
unlock_page(page);
if (nilfs_test_page_to_be_frozen(page)) {
int err = nilfs_copy_replace_page_buffers(page, out);
if (unlikely(err))
return err;
}
return 0;
}
static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
struct page **failed_page)
{
struct nilfs_segment_buffer *segbuf;
struct page *bd_page = NULL, *fs_page = NULL;
struct list_head *list = &sci->sc_copied_buffers;
int err;
*failed_page = NULL;
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
struct buffer_head *bh;
list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
b_assoc_buffers) {
if (bh->b_page != bd_page) {
if (bd_page) {
lock_page(bd_page);
clear_page_dirty_for_io(bd_page);
set_page_writeback(bd_page);
unlock_page(bd_page);
}
bd_page = bh->b_page;
}
}
list_for_each_entry(bh, &segbuf->sb_payload_buffers,
b_assoc_buffers) {
if (bh == sci->sc_super_root) {
if (bh->b_page != bd_page) {
lock_page(bd_page);
clear_page_dirty_for_io(bd_page);
set_page_writeback(bd_page);
unlock_page(bd_page);
bd_page = bh->b_page;
}
break;
}
if (bh->b_page != fs_page) {
err = nilfs_begin_page_io(fs_page, list);
if (unlikely(err)) {
*failed_page = fs_page;
goto out;
}
fs_page = bh->b_page;
}
}
}
if (bd_page) {
lock_page(bd_page);
clear_page_dirty_for_io(bd_page);
set_page_writeback(bd_page);
unlock_page(bd_page);
}
err = nilfs_begin_page_io(fs_page, list);
if (unlikely(err))
*failed_page = fs_page;
out:
return err;
}
static int nilfs_segctor_write(struct nilfs_sc_info *sci,
struct backing_dev_info *bdi)
{
struct nilfs_segment_buffer *segbuf;
struct nilfs_write_info wi;
int err, res;
wi.sb = sci->sc_super;
wi.bh_sr = sci->sc_super_root;
wi.bdi = bdi;
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
nilfs_segbuf_prepare_write(segbuf, &wi);
err = nilfs_segbuf_write(segbuf, &wi);
res = nilfs_segbuf_wait(segbuf, &wi);
err = unlikely(err) ? : res;
if (unlikely(err))
return err;
}
return 0;
}
static int nilfs_page_has_uncleared_buffer(struct page *page)
{
struct buffer_head *head, *bh;
head = bh = page_buffers(page);
do {
if (buffer_dirty(bh) && !list_empty(&bh->b_assoc_buffers))
return 1;
bh = bh->b_this_page;
} while (bh != head);
return 0;
}
static void __nilfs_end_page_io(struct page *page, int err)
{
if (!err) {
if (!nilfs_page_buffers_clean(page))
__set_page_dirty_nobuffers(page);
ClearPageError(page);
} else {
__set_page_dirty_nobuffers(page);
SetPageError(page);
}
if (buffer_nilfs_allocated(page_buffers(page))) {
if (TestClearPageWriteback(page))
dec_zone_page_state(page, NR_WRITEBACK);
} else
end_page_writeback(page);
}
static void nilfs_end_page_io(struct page *page, int err)
{
if (!page)
return;
if (buffer_nilfs_node(page_buffers(page)) &&
nilfs_page_has_uncleared_buffer(page))
/* For b-tree node pages, this function may be called twice
or more because they might be split in a segment.
This check assures that cleanup has been done for all
buffers in a split btnode page. */
return;
__nilfs_end_page_io(page, err);
}
static void nilfs_clear_copied_buffers(struct list_head *list, int err)
{
struct buffer_head *bh, *head;
struct page *page;
while (!list_empty(list)) {
bh = list_entry(list->next, struct buffer_head,
b_assoc_buffers);
page = bh->b_page;
page_cache_get(page);
head = bh = page_buffers(page);
do {
if (!list_empty(&bh->b_assoc_buffers)) {
list_del_init(&bh->b_assoc_buffers);
if (!err) {
set_buffer_uptodate(bh);
clear_buffer_dirty(bh);
clear_buffer_nilfs_volatile(bh);
}
brelse(bh); /* for b_assoc_buffers */
}
} while ((bh = bh->b_this_page) != head);
__nilfs_end_page_io(page, err);
page_cache_release(page);
}
}
static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
struct page *failed_page, int err)
{
struct nilfs_segment_buffer *segbuf;
struct page *bd_page = NULL, *fs_page = NULL;
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
struct buffer_head *bh;
list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
b_assoc_buffers) {
if (bh->b_page != bd_page) {
if (bd_page)
end_page_writeback(bd_page);
bd_page = bh->b_page;
}
}
list_for_each_entry(bh, &segbuf->sb_payload_buffers,
b_assoc_buffers) {
if (bh == sci->sc_super_root) {
if (bh->b_page != bd_page) {
end_page_writeback(bd_page);
bd_page = bh->b_page;
}
break;
}
if (bh->b_page != fs_page) {
nilfs_end_page_io(fs_page, err);
if (unlikely(fs_page == failed_page))
goto done;
fs_page = bh->b_page;
}
}
}
if (bd_page)
end_page_writeback(bd_page);
nilfs_end_page_io(fs_page, err);
done:
nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
}
static void nilfs_set_next_segment(struct the_nilfs *nilfs,
struct nilfs_segment_buffer *segbuf)
{
nilfs->ns_segnum = segbuf->sb_segnum;
nilfs->ns_nextnum = segbuf->sb_nextnum;
nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
+ segbuf->sb_sum.nblocks;
nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
nilfs->ns_ctime = segbuf->sb_sum.ctime;
}
static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
{
struct nilfs_segment_buffer *segbuf;
struct page *bd_page = NULL, *fs_page = NULL;
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct the_nilfs *nilfs = sbi->s_nilfs;
int update_sr = (sci->sc_super_root != NULL);
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
struct buffer_head *bh;
list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
b_assoc_buffers) {
set_buffer_uptodate(bh);
clear_buffer_dirty(bh);
if (bh->b_page != bd_page) {
if (bd_page)
end_page_writeback(bd_page);
bd_page = bh->b_page;
}
}
/*
* We assume that the buffers which belong to the same page
* continue over the buffer list.
* Under this assumption, the last BHs of pages is
* identifiable by the discontinuity of bh->b_page
* (page != fs_page).
*
* For B-tree node blocks, however, this assumption is not
* guaranteed. The cleanup code of B-tree node pages needs
* special care.
*/
list_for_each_entry(bh, &segbuf->sb_payload_buffers,
b_assoc_buffers) {
set_buffer_uptodate(bh);
clear_buffer_dirty(bh);
clear_buffer_nilfs_volatile(bh);
if (bh == sci->sc_super_root) {
if (bh->b_page != bd_page) {
end_page_writeback(bd_page);
bd_page = bh->b_page;
}
break;
}
if (bh->b_page != fs_page) {
nilfs_end_page_io(fs_page, 0);
fs_page = bh->b_page;
}
}
if (!NILFS_SEG_SIMPLEX(&segbuf->sb_sum)) {
if (NILFS_SEG_LOGBGN(&segbuf->sb_sum)) {
set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
sci->sc_lseg_stime = jiffies;
}
if (NILFS_SEG_LOGEND(&segbuf->sb_sum))
clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
}
}
/*
* Since pages may continue over multiple segment buffers,
* end of the last page must be checked outside of the loop.
*/
if (bd_page)
end_page_writeback(bd_page);
nilfs_end_page_io(fs_page, 0);
nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
nilfs_drop_collected_inodes(&sci->sc_dirty_files);
if (nilfs_doing_gc()) {
nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
if (update_sr)
nilfs_commit_gcdat_inode(nilfs);
} else
nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
sci->sc_nblk_inc += sci->sc_nblk_this_inc;
segbuf = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
nilfs_set_next_segment(nilfs, segbuf);
if (update_sr) {
nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
sbi->s_super->s_dirt = 1;
clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
} else
clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
}
static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
struct nilfs_sb_info *sbi)
{
struct nilfs_inode_info *ii, *n;
__u64 cno = sbi->s_nilfs->ns_cno;
spin_lock(&sbi->s_inode_lock);
retry:
list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
if (!ii->i_bh) {
struct buffer_head *ibh;
int err;
spin_unlock(&sbi->s_inode_lock);
err = nilfs_ifile_get_inode_block(
sbi->s_ifile, ii->vfs_inode.i_ino, &ibh);
if (unlikely(err)) {
nilfs_warning(sbi->s_super, __func__,
"failed to get inode block.\n");
return err;
}
nilfs_mdt_mark_buffer_dirty(ibh);
nilfs_mdt_mark_dirty(sbi->s_ifile);
spin_lock(&sbi->s_inode_lock);
if (likely(!ii->i_bh))
ii->i_bh = ibh;
else
brelse(ibh);
goto retry;
}
ii->i_cno = cno;
clear_bit(NILFS_I_QUEUED, &ii->i_state);
set_bit(NILFS_I_BUSY, &ii->i_state);
list_del(&ii->i_dirty);
list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
}
spin_unlock(&sbi->s_inode_lock);
NILFS_I(sbi->s_ifile)->i_cno = cno;
return 0;
}
static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
struct nilfs_sb_info *sbi)
{
struct nilfs_transaction_info *ti = current->journal_info;
struct nilfs_inode_info *ii, *n;
__u64 cno = sbi->s_nilfs->ns_cno;
spin_lock(&sbi->s_inode_lock);
list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
test_bit(NILFS_I_DIRTY, &ii->i_state)) {
/* The current checkpoint number (=nilfs->ns_cno) is
changed between check-in and check-out only if the
super root is written out. So, we can update i_cno
for the inodes that remain in the dirty list. */
ii->i_cno = cno;
continue;
}
clear_bit(NILFS_I_BUSY, &ii->i_state);
brelse(ii->i_bh);
ii->i_bh = NULL;
list_del(&ii->i_dirty);
list_add_tail(&ii->i_dirty, &ti->ti_garbage);
}
spin_unlock(&sbi->s_inode_lock);
}
/*
* Main procedure of segment constructor
*/
static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct the_nilfs *nilfs = sbi->s_nilfs;
struct page *failed_page;
int err, has_sr = 0;
sci->sc_stage.scnt = NILFS_ST_INIT;
err = nilfs_segctor_check_in_files(sci, sbi);
if (unlikely(err))
goto out;
if (nilfs_test_metadata_dirty(sbi))
set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
if (nilfs_segctor_clean(sci))
goto out;
do {
sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
err = nilfs_segctor_begin_construction(sci, nilfs);
if (unlikely(err))
goto out;
/* Update time stamp */
sci->sc_seg_ctime = get_seconds();
err = nilfs_segctor_collect(sci, nilfs, mode);
if (unlikely(err))
goto failed;
has_sr = (sci->sc_super_root != NULL);
/* Avoid empty segment */
if (sci->sc_stage.scnt == NILFS_ST_DONE &&
NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
nilfs_segctor_end_construction(sci, nilfs, 1);
goto out;
}
err = nilfs_segctor_assign(sci, mode);
if (unlikely(err))
goto failed;
if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
nilfs_segctor_fill_in_file_bmap(sci, sbi->s_ifile);
if (has_sr) {
err = nilfs_segctor_fill_in_checkpoint(sci);
if (unlikely(err))
goto failed_to_make_up;
nilfs_segctor_fill_in_super_root(sci, nilfs);
}
nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
/* Write partial segments */
err = nilfs_segctor_prepare_write(sci, &failed_page);
if (unlikely(err))
goto failed_to_write;
nilfs_segctor_fill_in_checksums(sci, nilfs->ns_crc_seed);
err = nilfs_segctor_write(sci, nilfs->ns_bdi);
if (unlikely(err))
goto failed_to_write;
nilfs_segctor_complete_write(sci);
/* Commit segments */
if (has_sr) {
nilfs_segctor_commit_free_segments(sci);
nilfs_segctor_clear_metadata_dirty(sci);
}
nilfs_segctor_end_construction(sci, nilfs, 0);
} while (sci->sc_stage.scnt != NILFS_ST_DONE);
out:
nilfs_segctor_destroy_segment_buffers(sci);
nilfs_segctor_check_out_files(sci, sbi);
return err;
failed_to_write:
nilfs_segctor_abort_write(sci, failed_page, err);
nilfs_segctor_cancel_segusage(sci, nilfs->ns_sufile);
failed_to_make_up:
if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
nilfs_redirty_inodes(&sci->sc_dirty_files);
failed:
if (nilfs_doing_gc())
nilfs_redirty_inodes(&sci->sc_gc_inodes);
nilfs_segctor_end_construction(sci, nilfs, err);
goto out;
}
/**
* nilfs_secgtor_start_timer - set timer of background write
* @sci: nilfs_sc_info
*
* If the timer has already been set, it ignores the new request.
* This function MUST be called within a section locking the segment
* semaphore.
*/
static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
{
spin_lock(&sci->sc_state_lock);
if (sci->sc_timer && !(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
sci->sc_timer->expires = jiffies + sci->sc_interval;
add_timer(sci->sc_timer);
sci->sc_state |= NILFS_SEGCTOR_COMMIT;
}
spin_unlock(&sci->sc_state_lock);
}
static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
{
spin_lock(&sci->sc_state_lock);
if (!(sci->sc_flush_request & (1 << bn))) {
unsigned long prev_req = sci->sc_flush_request;
sci->sc_flush_request |= (1 << bn);
if (!prev_req)
wake_up(&sci->sc_wait_daemon);
}
spin_unlock(&sci->sc_state_lock);
}
/**
* nilfs_flush_segment - trigger a segment construction for resource control
* @sb: super block
* @ino: inode number of the file to be flushed out.
*/
void nilfs_flush_segment(struct super_block *sb, ino_t ino)
{
struct nilfs_sb_info *sbi = NILFS_SB(sb);
struct nilfs_sc_info *sci = NILFS_SC(sbi);
if (!sci || nilfs_doing_construction())
return;
nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
/* assign bit 0 to data files */
}
int nilfs_segctor_add_segments_to_be_freed(struct nilfs_sc_info *sci,
__u64 *segnum, size_t nsegs)
{
struct nilfs_segment_entry *ent;
struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
struct inode *sufile = nilfs->ns_sufile;
LIST_HEAD(list);
__u64 *pnum;
size_t i;
int err;
for (pnum = segnum, i = 0; i < nsegs; pnum++, i++) {
ent = nilfs_alloc_segment_entry(*pnum);
if (unlikely(!ent)) {
err = -ENOMEM;
goto failed;
}
list_add_tail(&ent->list, &list);
err = nilfs_open_segment_entry(ent, sufile);
if (unlikely(err))
goto failed;
if (unlikely(!nilfs_segment_usage_dirty(ent->raw_su)))
printk(KERN_WARNING "NILFS: unused segment is "
"requested to be cleaned (segnum=%llu)\n",
(unsigned long long)ent->segnum);
nilfs_close_segment_entry(ent, sufile);
}
list_splice(&list, sci->sc_cleaning_segments.prev);
return 0;
failed:
nilfs_dispose_segment_list(&list);
return err;
}
void nilfs_segctor_clear_segments_to_be_freed(struct nilfs_sc_info *sci)
{
nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
}
struct nilfs_segctor_wait_request {
wait_queue_t wq;
__u32 seq;
int err;
atomic_t done;
};
static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
{
struct nilfs_segctor_wait_request wait_req;
int err = 0;
spin_lock(&sci->sc_state_lock);
init_wait(&wait_req.wq);
wait_req.err = 0;
atomic_set(&wait_req.done, 0);
wait_req.seq = ++sci->sc_seq_request;
spin_unlock(&sci->sc_state_lock);
init_waitqueue_entry(&wait_req.wq, current);
add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
set_current_state(TASK_INTERRUPTIBLE);
wake_up(&sci->sc_wait_daemon);
for (;;) {
if (atomic_read(&wait_req.done)) {
err = wait_req.err;
break;
}
if (!signal_pending(current)) {
schedule();
continue;
}
err = -ERESTARTSYS;
break;
}
finish_wait(&sci->sc_wait_request, &wait_req.wq);
return err;
}
static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
{
struct nilfs_segctor_wait_request *wrq, *n;
unsigned long flags;
spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
wq.task_list) {
if (!atomic_read(&wrq->done) &&
nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
wrq->err = err;
atomic_set(&wrq->done, 1);
}
if (atomic_read(&wrq->done)) {
wrq->wq.func(&wrq->wq,
TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
0, NULL);
}
}
spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
}
/**
* nilfs_construct_segment - construct a logical segment
* @sb: super block
*
* Return Value: On success, 0 is retured. On errors, one of the following
* negative error code is returned.
*
* %-EROFS - Read only filesystem.
*
* %-EIO - I/O error
*
* %-ENOSPC - No space left on device (only in a panic state).
*
* %-ERESTARTSYS - Interrupted.
*
* %-ENOMEM - Insufficient memory available.
*/
int nilfs_construct_segment(struct super_block *sb)
{
struct nilfs_sb_info *sbi = NILFS_SB(sb);
struct nilfs_sc_info *sci = NILFS_SC(sbi);
struct nilfs_transaction_info *ti;
int err;
if (!sci)
return -EROFS;
/* A call inside transactions causes a deadlock. */
BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
err = nilfs_segctor_sync(sci);
return err;
}
/**
* nilfs_construct_dsync_segment - construct a data-only logical segment
* @sb: super block
* @inode: inode whose data blocks should be written out
* @start: start byte offset
* @end: end byte offset (inclusive)
*
* Return Value: On success, 0 is retured. On errors, one of the following
* negative error code is returned.
*
* %-EROFS - Read only filesystem.
*
* %-EIO - I/O error
*
* %-ENOSPC - No space left on device (only in a panic state).
*
* %-ERESTARTSYS - Interrupted.
*
* %-ENOMEM - Insufficient memory available.
*/
int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
loff_t start, loff_t end)
{
struct nilfs_sb_info *sbi = NILFS_SB(sb);
struct nilfs_sc_info *sci = NILFS_SC(sbi);
struct nilfs_inode_info *ii;
struct nilfs_transaction_info ti;
int err = 0;
if (!sci)
return -EROFS;
nilfs_transaction_lock(sbi, &ti, 0);
ii = NILFS_I(inode);
if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
nilfs_test_opt(sbi, STRICT_ORDER) ||
test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
nilfs_discontinued(sbi->s_nilfs)) {
nilfs_transaction_unlock(sbi);
err = nilfs_segctor_sync(sci);
return err;
}
spin_lock(&sbi->s_inode_lock);
if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
!test_bit(NILFS_I_BUSY, &ii->i_state)) {
spin_unlock(&sbi->s_inode_lock);
nilfs_transaction_unlock(sbi);
return 0;
}
spin_unlock(&sbi->s_inode_lock);
sci->sc_dsync_inode = ii;
sci->sc_dsync_start = start;
sci->sc_dsync_end = end;
err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
nilfs_transaction_unlock(sbi);
return err;
}
struct nilfs_segctor_req {
int mode;
__u32 seq_accepted;
int sc_err; /* construction failure */
int sb_err; /* super block writeback failure */
};
#define FLUSH_FILE_BIT (0x1) /* data file only */
#define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
static void nilfs_segctor_accept(struct nilfs_sc_info *sci,
struct nilfs_segctor_req *req)
{
req->sc_err = req->sb_err = 0;
spin_lock(&sci->sc_state_lock);
req->seq_accepted = sci->sc_seq_request;
spin_unlock(&sci->sc_state_lock);
if (sci->sc_timer)
del_timer_sync(sci->sc_timer);
}
static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
struct nilfs_segctor_req *req)
{
/* Clear requests (even when the construction failed) */
spin_lock(&sci->sc_state_lock);
sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
if (req->mode == SC_LSEG_SR) {
sci->sc_seq_done = req->seq_accepted;
nilfs_segctor_wakeup(sci, req->sc_err ? : req->sb_err);
sci->sc_flush_request = 0;
} else if (req->mode == SC_FLUSH_FILE)
sci->sc_flush_request &= ~FLUSH_FILE_BIT;
else if (req->mode == SC_FLUSH_DAT)
sci->sc_flush_request &= ~FLUSH_DAT_BIT;
spin_unlock(&sci->sc_state_lock);
}
static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
struct nilfs_segctor_req *req)
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct the_nilfs *nilfs = sbi->s_nilfs;
int err = 0;
if (nilfs_discontinued(nilfs))
req->mode = SC_LSEG_SR;
if (!nilfs_segctor_confirm(sci)) {
err = nilfs_segctor_do_construct(sci, req->mode);
req->sc_err = err;
}
if (likely(!err)) {
if (req->mode != SC_FLUSH_DAT)
atomic_set(&nilfs->ns_ndirtyblks, 0);
if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
nilfs_discontinued(nilfs)) {
down_write(&nilfs->ns_sem);
req->sb_err = nilfs_commit_super(sbi, 0);
up_write(&nilfs->ns_sem);
}
}
return err;
}
static void nilfs_construction_timeout(unsigned long data)
{
struct task_struct *p = (struct task_struct *)data;
wake_up_process(p);
}
static void
nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
{
struct nilfs_inode_info *ii, *n;
list_for_each_entry_safe(ii, n, head, i_dirty) {
if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
continue;
hlist_del_init(&ii->vfs_inode.i_hash);
list_del_init(&ii->i_dirty);
nilfs_clear_gcinode(&ii->vfs_inode);
}
}
int nilfs_clean_segments(struct super_block *sb, void __user *argp)
{
struct nilfs_sb_info *sbi = NILFS_SB(sb);
struct nilfs_sc_info *sci = NILFS_SC(sbi);
struct the_nilfs *nilfs = sbi->s_nilfs;
struct nilfs_transaction_info ti;
struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
int err;
if (unlikely(!sci))
return -EROFS;
nilfs_transaction_lock(sbi, &ti, 1);
err = nilfs_init_gcdat_inode(nilfs);
if (unlikely(err))
goto out_unlock;
err = nilfs_ioctl_prepare_clean_segments(nilfs, argp);
if (unlikely(err))
goto out_unlock;
list_splice_init(&nilfs->ns_gc_inodes, sci->sc_gc_inodes.prev);
for (;;) {
nilfs_segctor_accept(sci, &req);
err = nilfs_segctor_construct(sci, &req);
nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
nilfs_segctor_notify(sci, &req);
if (likely(!err))
break;
nilfs_warning(sb, __func__,
"segment construction failed. (err=%d)", err);
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(sci->sc_interval);
}
out_unlock:
nilfs_clear_gcdat_inode(nilfs);
nilfs_transaction_unlock(sbi);
return err;
}
static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct nilfs_transaction_info ti;
struct nilfs_segctor_req req = { .mode = mode };
nilfs_transaction_lock(sbi, &ti, 0);
nilfs_segctor_accept(sci, &req);
nilfs_segctor_construct(sci, &req);
nilfs_segctor_notify(sci, &req);
/*
* Unclosed segment should be retried. We do this using sc_timer.
* Timeout of sc_timer will invoke complete construction which leads
* to close the current logical segment.
*/
if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
nilfs_segctor_start_timer(sci);
nilfs_transaction_unlock(sbi);
}
static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
{
int mode = 0;
int err;
spin_lock(&sci->sc_state_lock);
mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
SC_FLUSH_DAT : SC_FLUSH_FILE;
spin_unlock(&sci->sc_state_lock);
if (mode) {
err = nilfs_segctor_do_construct(sci, mode);
spin_lock(&sci->sc_state_lock);
sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
spin_unlock(&sci->sc_state_lock);
}
clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
}
static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
{
if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
return SC_FLUSH_FILE;
else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
return SC_FLUSH_DAT;
}
return SC_LSEG_SR;
}
/**
* nilfs_segctor_thread - main loop of the segment constructor thread.
* @arg: pointer to a struct nilfs_sc_info.
*
* nilfs_segctor_thread() initializes a timer and serves as a daemon
* to execute segment constructions.
*/
static int nilfs_segctor_thread(void *arg)
{
struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
struct timer_list timer;
int timeout = 0;
init_timer(&timer);
timer.data = (unsigned long)current;
timer.function = nilfs_construction_timeout;
sci->sc_timer = &timer;
/* start sync. */
sci->sc_task = current;
wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
printk(KERN_INFO
"segctord starting. Construction interval = %lu seconds, "
"CP frequency < %lu seconds\n",
sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
spin_lock(&sci->sc_state_lock);
loop:
for (;;) {
int mode;
if (sci->sc_state & NILFS_SEGCTOR_QUIT)
goto end_thread;
if (timeout || sci->sc_seq_request != sci->sc_seq_done)
mode = SC_LSEG_SR;
else if (!sci->sc_flush_request)
break;
else
mode = nilfs_segctor_flush_mode(sci);
spin_unlock(&sci->sc_state_lock);
nilfs_segctor_thread_construct(sci, mode);
spin_lock(&sci->sc_state_lock);
timeout = 0;
}
if (freezing(current)) {
spin_unlock(&sci->sc_state_lock);
refrigerator();
spin_lock(&sci->sc_state_lock);
} else {
DEFINE_WAIT(wait);
int should_sleep = 1;
prepare_to_wait(&sci->sc_wait_daemon, &wait,
TASK_INTERRUPTIBLE);
if (sci->sc_seq_request != sci->sc_seq_done)
should_sleep = 0;
else if (sci->sc_flush_request)
should_sleep = 0;
else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
should_sleep = time_before(jiffies,
sci->sc_timer->expires);
if (should_sleep) {
spin_unlock(&sci->sc_state_lock);
schedule();
spin_lock(&sci->sc_state_lock);
}
finish_wait(&sci->sc_wait_daemon, &wait);
timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
time_after_eq(jiffies, sci->sc_timer->expires));
}
goto loop;
end_thread:
spin_unlock(&sci->sc_state_lock);
del_timer_sync(sci->sc_timer);
sci->sc_timer = NULL;
/* end sync. */
sci->sc_task = NULL;
wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
return 0;
}
static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
{
struct task_struct *t;
t = kthread_run(nilfs_segctor_thread, sci, "segctord");
if (IS_ERR(t)) {
int err = PTR_ERR(t);
printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
err);
return err;
}
wait_event(sci->sc_wait_task, sci->sc_task != NULL);
return 0;
}
static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
{
sci->sc_state |= NILFS_SEGCTOR_QUIT;
while (sci->sc_task) {
wake_up(&sci->sc_wait_daemon);
spin_unlock(&sci->sc_state_lock);
wait_event(sci->sc_wait_task, sci->sc_task == NULL);
spin_lock(&sci->sc_state_lock);
}
}
static int nilfs_segctor_init(struct nilfs_sc_info *sci)
{
sci->sc_seq_done = sci->sc_seq_request;
return nilfs_segctor_start_thread(sci);
}
/*
* Setup & clean-up functions
*/
static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
{
struct nilfs_sc_info *sci;
sci = kzalloc(sizeof(*sci), GFP_KERNEL);
if (!sci)
return NULL;
sci->sc_sbi = sbi;
sci->sc_super = sbi->s_super;
init_waitqueue_head(&sci->sc_wait_request);
init_waitqueue_head(&sci->sc_wait_daemon);
init_waitqueue_head(&sci->sc_wait_task);
spin_lock_init(&sci->sc_state_lock);
INIT_LIST_HEAD(&sci->sc_dirty_files);
INIT_LIST_HEAD(&sci->sc_segbufs);
INIT_LIST_HEAD(&sci->sc_gc_inodes);
INIT_LIST_HEAD(&sci->sc_cleaning_segments);
INIT_LIST_HEAD(&sci->sc_copied_buffers);
sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
if (sbi->s_interval)
sci->sc_interval = sbi->s_interval;
if (sbi->s_watermark)
sci->sc_watermark = sbi->s_watermark;
return sci;
}
static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
{
int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
/* The segctord thread was stopped and its timer was removed.
But some tasks remain. */
do {
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct nilfs_transaction_info ti;
struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
nilfs_transaction_lock(sbi, &ti, 0);
nilfs_segctor_accept(sci, &req);
ret = nilfs_segctor_construct(sci, &req);
nilfs_segctor_notify(sci, &req);
nilfs_transaction_unlock(sbi);
} while (ret && retrycount-- > 0);
}
/**
* nilfs_segctor_destroy - destroy the segment constructor.
* @sci: nilfs_sc_info
*
* nilfs_segctor_destroy() kills the segctord thread and frees
* the nilfs_sc_info struct.
* Caller must hold the segment semaphore.
*/
static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
int flag;
up_write(&sbi->s_nilfs->ns_segctor_sem);
spin_lock(&sci->sc_state_lock);
nilfs_segctor_kill_thread(sci);
flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
|| sci->sc_seq_request != sci->sc_seq_done);
spin_unlock(&sci->sc_state_lock);
if (flag || nilfs_segctor_confirm(sci))
nilfs_segctor_write_out(sci);
WARN_ON(!list_empty(&sci->sc_copied_buffers));
if (!list_empty(&sci->sc_dirty_files)) {
nilfs_warning(sbi->s_super, __func__,
"dirty file(s) after the final construction\n");
nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
}
if (!list_empty(&sci->sc_cleaning_segments))
nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
WARN_ON(!list_empty(&sci->sc_segbufs));
down_write(&sbi->s_nilfs->ns_segctor_sem);
kfree(sci);
}
/**
* nilfs_attach_segment_constructor - attach a segment constructor
* @sbi: nilfs_sb_info
*
* nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
* initilizes it, and starts the segment constructor.
*
* Return Value: On success, 0 is returned. On error, one of the following
* negative error code is returned.
*
* %-ENOMEM - Insufficient memory available.
*/
int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
int err;
/* Each field of nilfs_segctor is cleared through the initialization
of super-block info */
sbi->s_sc_info = nilfs_segctor_new(sbi);
if (!sbi->s_sc_info)
return -ENOMEM;
nilfs_attach_writer(nilfs, sbi);
err = nilfs_segctor_init(NILFS_SC(sbi));
if (err) {
nilfs_detach_writer(nilfs, sbi);
kfree(sbi->s_sc_info);
sbi->s_sc_info = NULL;
}
return err;
}
/**
* nilfs_detach_segment_constructor - destroy the segment constructor
* @sbi: nilfs_sb_info
*
* nilfs_detach_segment_constructor() kills the segment constructor daemon,
* frees the struct nilfs_sc_info, and destroy the dirty file list.
*/
void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
LIST_HEAD(garbage_list);
down_write(&nilfs->ns_segctor_sem);
if (NILFS_SC(sbi)) {
nilfs_segctor_destroy(NILFS_SC(sbi));
sbi->s_sc_info = NULL;
}
/* Force to free the list of dirty files */
spin_lock(&sbi->s_inode_lock);
if (!list_empty(&sbi->s_dirty_files)) {
list_splice_init(&sbi->s_dirty_files, &garbage_list);
nilfs_warning(sbi->s_super, __func__,
"Non empty dirty list after the last "
"segment construction\n");
}
spin_unlock(&sbi->s_inode_lock);
up_write(&nilfs->ns_segctor_sem);
nilfs_dispose_list(sbi, &garbage_list, 1);
nilfs_detach_writer(nilfs, sbi);
}