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linux/fs/nilfs2/segment.c
Ryusuke Konishi e3154e9748 nilfs2: get rid of nilfs_sb_info structure 
This directly uses sb->s_fs_info to keep a nilfs filesystem object and
fully removes the intermediate nilfs_sb_info structure.  With this
change, the hierarchy of on-memory structures of nilfs will be
simplified as follows:

Before:
  super_block
       -> nilfs_sb_info
             -> the_nilfs
                   -> cptree --+-> nilfs_root (current file system)
                               +-> nilfs_root (snapshot A)
                               +-> nilfs_root (snapshot B)
                               :
             -> nilfs_sc_info (log writer structure)
After:
  super_block
       -> the_nilfs
             -> cptree --+-> nilfs_root (current file system)
                         +-> nilfs_root (snapshot A)
                         +-> nilfs_root (snapshot B)
                         :
             -> nilfs_sc_info (log writer structure)

The reason why we didn't design so from the beginning is because the
initial shape also differed from the above.  The early hierachy was
composed of "per-mount-point" super_block -> nilfs_sb_info pairs and a
shared nilfs object.  On the kernel 2.6.37, it was changed to the
current shape in order to unify super block instances into one per
device, and this cleanup became applicable as the result.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:54:26 +09:00

2831 lines
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/*
* 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 <linux/slab.h>
#include "nilfs.h"
#include "btnode.h"
#include "page.h"
#include "segment.h"
#include "sufile.h"
#include "cpfile.h"
#include "ifile.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_SUFREED 0x0004 /* segment usages has been freed */
#define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
/* 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 the_nilfs *, 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)
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; otherwise 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 the_nilfs *nilfs;
int ret = nilfs_prepare_segment_lock(ti);
if (unlikely(ret < 0))
return ret;
if (ret > 0)
return 0;
vfs_check_frozen(sb, SB_FREEZE_WRITE);
nilfs = sb->s_fs_info;
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 the_nilfs *nilfs = sb->s_fs_info;
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;
}
if (nilfs->ns_writer) {
struct nilfs_sc_info *sci = nilfs->ns_writer;
if (ti->ti_flags & NILFS_TI_COMMIT)
nilfs_segctor_start_timer(sci);
if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
nilfs_segctor_do_flush(sci, 0);
}
up_read(&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;
struct the_nilfs *nilfs = sb->s_fs_info;
BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
if (ti->ti_count > 0) {
ti->ti_count--;
return;
}
up_read(&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 the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_sc_info *sci = nilfs->ns_writer;
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 super_block *sb,
struct nilfs_transaction_info *ti,
int gcflag)
{
struct nilfs_transaction_info *cur_ti = current->journal_info;
struct the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_sc_info *sci = nilfs->ns_writer;
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(&nilfs->ns_segctor_sem);
if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
break;
nilfs_segctor_do_immediate_flush(sci);
up_write(&nilfs->ns_segctor_sem);
yield();
}
if (gcflag)
ti->ti_flags |= NILFS_TI_GC;
}
static void nilfs_transaction_unlock(struct super_block *sb)
{
struct nilfs_transaction_info *ti = current->journal_info;
struct the_nilfs *nilfs = sb->s_fs_info;
BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
BUG_ON(ti->ti_count > 0);
up_write(&nilfs->ns_segctor_sem);
current->journal_info = ti->ti_save;
if (!list_empty(&ti->ti_garbage))
nilfs_dispose_list(nilfs, &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, sci->sc_cno);
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, &segbuf->sb_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 (NILFS_I(inode)->i_root &&
!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;
__u64 cno;
if (sci->sc_blk_cnt == 0)
return;
ii = NILFS_I(inode);
if (test_bit(NILFS_I_GCINODE, &ii->i_state))
cno = ii->i_cno;
else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
cno = 0;
else
cno = sci->sc_cno;
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(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;
}
/*
* 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 (err < 0)
return err;
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)
{
return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
}
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;
}
static 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 (err < 0)
return err;
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;
}
static 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,
};
static 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 the_nilfs *nilfs,
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(&nilfs->ns_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,
&nilfs->ns_dirty_files);
continue;
}
ivec[nv++] = ii;
if (nv == SC_N_INODEVEC)
break;
}
spin_unlock(&nilfs->ns_inode_lock);
for (pii = ivec; nv > 0; pii++, nv--)
iput(&(*pii)->vfs_inode);
}
}
static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
struct nilfs_root *root)
{
int ret = 0;
if (nilfs_mdt_fetch_dirty(root->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()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
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) &&
sci->sc_nfreesegs == 0 &&
(!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
}
static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
{
struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
int ret = 0;
if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
spin_lock(&nilfs->ns_inode_lock);
if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
ret++;
spin_unlock(&nilfs->ns_inode_lock);
return ret;
}
static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
{
struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
nilfs_mdt_clear_dirty(sci->sc_root->ifile);
nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
nilfs_mdt_clear_dirty(nilfs->ns_sufile);
nilfs_mdt_clear_dirty(nilfs->ns_dat);
}
static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
{
struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
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 the_nilfs *nilfs = sci->sc_super->s_fs_info;
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(&sci->sc_root->inodes_count));
raw_cp->cp_blocks_count =
cpu_to_le64(atomic_read(&sci->sc_root->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(sci->sc_root->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 nilfs_inode_info *ii;
list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
set_bit(NILFS_I_COLLECTED, &ii->i_state);
}
}
static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs)
{
struct buffer_head *bh_sr;
struct nilfs_super_root *raw_sr;
unsigned isz = nilfs->ns_inode_size;
bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
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_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
NILFS_SR_DAT_OFFSET(isz), 1);
nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
NILFS_SR_CPFILE_OFFSET(isz), 1);
nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
NILFS_SR_SUFILE_OFFSET(isz), 1);
}
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 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 the_nilfs *nilfs = sci->sc_super->s_fs_info;
struct list_head *head;
struct nilfs_inode_info *ii;
size_t ndone;
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, sci->sc_root->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_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
sci->sc_nfreesegs, &ndone);
if (unlikely(err)) {
nilfs_sufile_cancel_freev(nilfs->ns_sufile,
sci->sc_freesegs, ndone,
NULL);
break;
}
sci->sc_stage.flags |= NILFS_CF_SUFREED;
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->ns_dat,
&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;
}
/**
* nilfs_segctor_begin_construction - setup segment buffer to make a new log
* @sci: nilfs_sc_info
* @nilfs: nilfs object
*/
static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs)
{
struct nilfs_segment_buffer *segbuf, *prev;
__u64 nextnum;
int err, alloc = 0;
segbuf = nilfs_segbuf_new(sci->sc_super);
if (unlikely(!segbuf))
return -ENOMEM;
if (list_empty(&sci->sc_write_logs)) {
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);
}
segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
nextnum = nilfs->ns_nextnum;
if (nilfs->ns_segnum == nilfs->ns_nextnum)
/* Start from the head of a new full segment */
alloc++;
} else {
/* Continue logs */
prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
nilfs_segbuf_map_cont(segbuf, prev);
segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
nextnum = prev->sb_nextnum;
if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
segbuf->sb_sum.seg_seq++;
alloc++;
}
}
err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
if (err)
goto failed;
if (alloc) {
err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
if (err)
goto failed;
}
nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
BUG_ON(!list_empty(&sci->sc_segbufs));
list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
return 0;
failed:
nilfs_segbuf_free(segbuf);
return err;
}
static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs, int nadd)
{
struct nilfs_segment_buffer *segbuf, *prev;
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_sufile_mark_dirty(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_tail(&list, &sci->sc_segbufs);
return 0;
failed_segbuf:
nilfs_segbuf_free(segbuf);
failed:
list_for_each_entry(segbuf, &list, sb_list) {
ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
WARN_ON(ret); /* never fails */
}
nilfs_destroy_logs(&list);
return err;
}
static void nilfs_free_incomplete_logs(struct list_head *logs,
struct the_nilfs *nilfs)
{
struct nilfs_segment_buffer *segbuf, *prev;
struct inode *sufile = nilfs->ns_sufile;
int ret;
segbuf = NILFS_FIRST_SEGBUF(logs);
if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
WARN_ON(ret); /* never fails */
}
if (atomic_read(&segbuf->sb_err)) {
/* 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);
}
prev = segbuf;
list_for_each_entry_continue(segbuf, logs, sb_list) {
if (prev->sb_nextnum != segbuf->sb_nextnum) {
ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
WARN_ON(ret); /* never fails */
}
if (atomic_read(&segbuf->sb_err) &&
segbuf->sb_segnum != nilfs->ns_nextnum)
/* Case 2: extended segment (!= next) failed */
nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
prev = segbuf;
}
}
static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
struct inode *sufile)
{
struct nilfs_segment_buffer *segbuf;
unsigned long live_blocks;
int ret;
list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
live_blocks = segbuf->sb_sum.nblocks +
(segbuf->sb_pseg_start - segbuf->sb_fseg_start);
ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
live_blocks,
sci->sc_seg_ctime);
WARN_ON(ret); /* always succeed because the segusage is dirty */
}
}
static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
{
struct nilfs_segment_buffer *segbuf;
int ret;
segbuf = NILFS_FIRST_SEGBUF(logs);
ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
segbuf->sb_pseg_start -
segbuf->sb_fseg_start, 0);
WARN_ON(ret); /* always succeed because the segusage is dirty */
list_for_each_entry_continue(segbuf, logs, sb_list) {
ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
0, 0);
WARN_ON(ret); /* always succeed */
}
}
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;
int ret;
list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
WARN_ON(ret);
}
nilfs_truncate_logs(&sci->sc_segbufs, last);
}
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_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_clear_logs(&sci->sc_segbufs);
err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
if (unlikely(err))
return err;
if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
sci->sc_freesegs,
sci->sc_nfreesegs,
NULL);
WARN_ON(err); /* do not happen */
}
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 == segbuf->sb_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:
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))
account_page_writeback(clone_page);
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 == segbuf->sb_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 the_nilfs *nilfs)
{
int ret;
ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
return ret;
}
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)) && !PageWriteback(page)) {
/*
* For b-tree node pages, this function may be called twice
* or more because they might be split in a segment.
*/
if (PageDirty(page)) {
/*
* For pages holding split b-tree node buffers, dirty
* flag on the buffers may be cleared discretely.
* In that case, the page is once redirtied for
* remaining buffers, and it must be cancelled if
* all the buffers get cleaned later.
*/
lock_page(page);
if (nilfs_page_buffers_clean(page))
__nilfs_clear_page_dirty(page);
unlock_page(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_delay(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_abort_logs(struct list_head *logs, struct page *failed_page,
int err)
{
struct nilfs_segment_buffer *segbuf;
struct page *bd_page = NULL, *fs_page = NULL;
struct buffer_head *bh;
if (list_empty(logs))
return;
list_for_each_entry(segbuf, logs, sb_list) {
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 == segbuf->sb_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 (fs_page && fs_page == failed_page)
return;
fs_page = bh->b_page;
}
}
}
if (bd_page)
end_page_writeback(bd_page);
nilfs_end_page_io(fs_page, err);
}
static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs, int err)
{
LIST_HEAD(logs);
int ret;
list_splice_tail_init(&sci->sc_write_logs, &logs);
ret = nilfs_wait_on_logs(&logs);
nilfs_abort_logs(&logs, NULL, ret ? : err);
list_splice_tail_init(&sci->sc_segbufs, &logs);
nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
nilfs_free_incomplete_logs(&logs, nilfs);
nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
sci->sc_freesegs,
sci->sc_nfreesegs,
NULL);
WARN_ON(ret); /* do not happen */
}
nilfs_destroy_logs(&logs);
}
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 the_nilfs *nilfs = sci->sc_super->s_fs_info;
int update_sr = false;
list_for_each_entry(segbuf, &sci->sc_write_logs, 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_delay(bh);
clear_buffer_nilfs_volatile(bh);
clear_buffer_nilfs_redirected(bh);
if (bh == segbuf->sb_super_root) {
if (bh->b_page != bd_page) {
end_page_writeback(bd_page);
bd_page = bh->b_page;
}
update_sr = true;
break;
}
if (bh->b_page != fs_page) {
nilfs_end_page_io(fs_page, 0);
fs_page = bh->b_page;
}
}
if (!nilfs_segbuf_simplex(segbuf)) {
if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
sci->sc_lseg_stime = jiffies;
}
if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
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);
else
nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
sci->sc_nblk_inc += sci->sc_nblk_this_inc;
segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
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++);
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);
nilfs_segctor_clear_metadata_dirty(sci);
} else
clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
}
static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
{
int ret;
ret = nilfs_wait_on_logs(&sci->sc_write_logs);
if (!ret) {
nilfs_segctor_complete_write(sci);
nilfs_destroy_logs(&sci->sc_write_logs);
}
return ret;
}
static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs)
{
struct nilfs_inode_info *ii, *n;
struct inode *ifile = sci->sc_root->ifile;
spin_lock(&nilfs->ns_inode_lock);
retry:
list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
if (!ii->i_bh) {
struct buffer_head *ibh;
int err;
spin_unlock(&nilfs->ns_inode_lock);
err = nilfs_ifile_get_inode_block(
ifile, ii->vfs_inode.i_ino, &ibh);
if (unlikely(err)) {
nilfs_warning(sci->sc_super, __func__,
"failed to get inode block.\n");
return err;
}
nilfs_mdt_mark_buffer_dirty(ibh);
nilfs_mdt_mark_dirty(ifile);
spin_lock(&nilfs->ns_inode_lock);
if (likely(!ii->i_bh))
ii->i_bh = ibh;
else
brelse(ibh);
goto retry;
}
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(&nilfs->ns_inode_lock);
return 0;
}
static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
struct the_nilfs *nilfs)
{
struct nilfs_transaction_info *ti = current->journal_info;
struct nilfs_inode_info *ii, *n;
spin_lock(&nilfs->ns_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))
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(&nilfs->ns_inode_lock);
}
/*
* Main procedure of segment constructor
*/
static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
{
struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
struct page *failed_page;
int err;
sci->sc_stage.scnt = NILFS_ST_INIT;
sci->sc_cno = nilfs->ns_cno;
err = nilfs_segctor_collect_dirty_files(sci, nilfs);
if (unlikely(err))
goto out;
if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
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;
/* Avoid empty segment */
if (sci->sc_stage.scnt == NILFS_ST_DONE &&
nilfs_segbuf_empty(sci->sc_curseg)) {
nilfs_segctor_abort_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);
if (mode == SC_LSEG_SR &&
sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
err = nilfs_segctor_fill_in_checkpoint(sci);
if (unlikely(err))
goto failed_to_write;
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 (err) {
nilfs_abort_logs(&sci->sc_segbufs, failed_page, err);
goto failed_to_write;
}
nilfs_add_checksums_on_logs(&sci->sc_segbufs,
nilfs->ns_crc_seed);
err = nilfs_segctor_write(sci, nilfs);
if (unlikely(err))
goto failed_to_write;
if (sci->sc_stage.scnt == NILFS_ST_DONE ||
nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
/*
* At this point, we avoid double buffering
* for blocksize < pagesize because page dirty
* flag is turned off during write and dirty
* buffers are not properly collected for
* pages crossing over segments.
*/
err = nilfs_segctor_wait(sci);
if (err)
goto failed_to_write;
}
} while (sci->sc_stage.scnt != NILFS_ST_DONE);
out:
nilfs_segctor_drop_written_files(sci, nilfs);
return err;
failed_to_write:
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_abort_construction(sci, nilfs, err);
goto out;
}
/**
* nilfs_segctor_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_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 the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_sc_info *sci = nilfs->ns_writer;
if (!sci || nilfs_doing_construction())
return;
nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
/* assign bit 0 to data files */
}
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 the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_sc_info *sci = nilfs->ns_writer;
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 the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_sc_info *sci = nilfs->ns_writer;
struct nilfs_inode_info *ii;
struct nilfs_transaction_info ti;
int err = 0;
if (!sci)
return -EROFS;
nilfs_transaction_lock(sb, &ti, 0);
ii = NILFS_I(inode);
if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
nilfs_test_opt(nilfs, STRICT_ORDER) ||
test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
nilfs_discontinued(nilfs)) {
nilfs_transaction_unlock(sb);
err = nilfs_segctor_sync(sci);
return err;
}
spin_lock(&nilfs->ns_inode_lock);
if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
!test_bit(NILFS_I_BUSY, &ii->i_state)) {
spin_unlock(&nilfs->ns_inode_lock);
nilfs_transaction_unlock(sb);
return 0;
}
spin_unlock(&nilfs->ns_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(sb);
return err;
}
#define FLUSH_FILE_BIT (0x1) /* data file only */
#define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
/**
* nilfs_segctor_accept - record accepted sequence count of log-write requests
* @sci: segment constructor object
*/
static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
{
spin_lock(&sci->sc_state_lock);
sci->sc_seq_accepted = sci->sc_seq_request;
spin_unlock(&sci->sc_state_lock);
del_timer_sync(&sci->sc_timer);
}
/**
* nilfs_segctor_notify - notify the result of request to caller threads
* @sci: segment constructor object
* @mode: mode of log forming
* @err: error code to be notified
*/
static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
{
/* Clear requests (even when the construction failed) */
spin_lock(&sci->sc_state_lock);
if (mode == SC_LSEG_SR) {
sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
sci->sc_seq_done = sci->sc_seq_accepted;
nilfs_segctor_wakeup(sci, err);
sci->sc_flush_request = 0;
} else {
if (mode == SC_FLUSH_FILE)
sci->sc_flush_request &= ~FLUSH_FILE_BIT;
else if (mode == SC_FLUSH_DAT)
sci->sc_flush_request &= ~FLUSH_DAT_BIT;
/* re-enable timer if checkpoint creation was not done */
if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
time_before(jiffies, sci->sc_timer.expires))
add_timer(&sci->sc_timer);
}
spin_unlock(&sci->sc_state_lock);
}
/**
* nilfs_segctor_construct - form logs and write them to disk
* @sci: segment constructor object
* @mode: mode of log forming
*/
static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
{
struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
struct nilfs_super_block **sbp;
int err = 0;
nilfs_segctor_accept(sci);
if (nilfs_discontinued(nilfs))
mode = SC_LSEG_SR;
if (!nilfs_segctor_confirm(sci))
err = nilfs_segctor_do_construct(sci, mode);
if (likely(!err)) {
if (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);
err = -EIO;
sbp = nilfs_prepare_super(sci->sc_super,
nilfs_sb_will_flip(nilfs));
if (likely(sbp)) {
nilfs_set_log_cursor(sbp[0], nilfs);
err = nilfs_commit_super(sci->sc_super,
NILFS_SB_COMMIT);
}
up_write(&nilfs->ns_sem);
}
}
nilfs_segctor_notify(sci, mode, err);
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;
list_del_init(&ii->i_dirty);
iput(&ii->vfs_inode);
}
}
int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
void **kbufs)
{
struct the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_sc_info *sci = nilfs->ns_writer;
struct nilfs_transaction_info ti;
int err;
if (unlikely(!sci))
return -EROFS;
nilfs_transaction_lock(sb, &ti, 1);
err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
if (unlikely(err))
goto out_unlock;
err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
if (unlikely(err)) {
nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
goto out_unlock;
}
sci->sc_freesegs = kbufs[4];
sci->sc_nfreesegs = argv[4].v_nmembs;
list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
for (;;) {
err = nilfs_segctor_construct(sci, SC_LSEG_SR);
nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
if (likely(!err))
break;
nilfs_warning(sb, __func__,
"segment construction failed. (err=%d)", err);
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(sci->sc_interval);
}
if (nilfs_test_opt(nilfs, DISCARD)) {
int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
sci->sc_nfreesegs);
if (ret) {
printk(KERN_WARNING
"NILFS warning: error %d on discard request, "
"turning discards off for the device\n", ret);
nilfs_clear_opt(nilfs, DISCARD);
}
}
out_unlock:
sci->sc_freesegs = NULL;
sci->sc_nfreesegs = 0;
nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
nilfs_transaction_unlock(sb);
return err;
}
static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
{
struct nilfs_transaction_info ti;
nilfs_transaction_lock(sci->sc_super, &ti, 0);
nilfs_segctor_construct(sci, mode);
/*
* 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(sci->sc_super);
}
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 the_nilfs *nilfs = sci->sc_super->s_fs_info;
int timeout = 0;
sci->sc_timer.data = (unsigned long)current;
sci->sc_timer.function = nilfs_construction_timeout;
/* 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));
if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
set_nilfs_discontinued(nilfs);
}
goto loop;
end_thread:
spin_unlock(&sci->sc_state_lock);
/* 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)
__acquires(&sci->sc_state_lock)
__releases(&sci->sc_state_lock)
{
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);
}
}
/*
* Setup & clean-up functions
*/
static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
struct nilfs_root *root)
{
struct the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_sc_info *sci;
sci = kzalloc(sizeof(*sci), GFP_KERNEL);
if (!sci)
return NULL;
sci->sc_super = sb;
nilfs_get_root(root);
sci->sc_root = root;
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_write_logs);
INIT_LIST_HEAD(&sci->sc_gc_inodes);
INIT_LIST_HEAD(&sci->sc_copied_buffers);
init_timer(&sci->sc_timer);
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 (nilfs->ns_interval)
sci->sc_interval = nilfs->ns_interval;
if (nilfs->ns_watermark)
sci->sc_watermark = nilfs->ns_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_transaction_info ti;
nilfs_transaction_lock(sci->sc_super, &ti, 0);
ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
nilfs_transaction_unlock(sci->sc_super);
} 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 the_nilfs *nilfs = sci->sc_super->s_fs_info;
int flag;
up_write(&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(sci->sc_super, __func__,
"dirty file(s) after the final construction\n");
nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
}
WARN_ON(!list_empty(&sci->sc_segbufs));
WARN_ON(!list_empty(&sci->sc_write_logs));
nilfs_put_root(sci->sc_root);
down_write(&nilfs->ns_segctor_sem);
del_timer_sync(&sci->sc_timer);
kfree(sci);
}
/**
* nilfs_attach_log_writer - attach log writer
* @sb: super block instance
* @root: root object of the current filesystem tree
*
* This allocates a log writer object, initializes it, and starts the
* log writer.
*
* 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_log_writer(struct super_block *sb, struct nilfs_root *root)
{
struct the_nilfs *nilfs = sb->s_fs_info;
int err;
if (nilfs->ns_writer) {
/*
* This happens if the filesystem was remounted
* read/write after nilfs_error degenerated it into a
* read-only mount.
*/
nilfs_detach_log_writer(sb);
}
nilfs->ns_writer = nilfs_segctor_new(sb, root);
if (!nilfs->ns_writer)
return -ENOMEM;
err = nilfs_segctor_start_thread(nilfs->ns_writer);
if (err) {
kfree(nilfs->ns_writer);
nilfs->ns_writer = NULL;
}
return err;
}
/**
* nilfs_detach_log_writer - destroy log writer
* @sb: super block instance
*
* This kills log writer daemon, frees the log writer object, and
* destroys list of dirty files.
*/
void nilfs_detach_log_writer(struct super_block *sb)
{
struct the_nilfs *nilfs = sb->s_fs_info;
LIST_HEAD(garbage_list);
down_write(&nilfs->ns_segctor_sem);
if (nilfs->ns_writer) {
nilfs_segctor_destroy(nilfs->ns_writer);
nilfs->ns_writer = NULL;
}
/* Force to free the list of dirty files */
spin_lock(&nilfs->ns_inode_lock);
if (!list_empty(&nilfs->ns_dirty_files)) {
list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
nilfs_warning(sb, __func__,
"Hit dirty file after stopped log writer\n");
}
spin_unlock(&nilfs->ns_inode_lock);
up_write(&nilfs->ns_segctor_sem);
nilfs_dispose_list(nilfs, &garbage_list, 1);
}
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