linux/fs/f2fs/checkpoint.c

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/*
* fs/f2fs/checkpoint.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/fs.h>
#include <linux/bio.h>
#include <linux/mpage.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/f2fs_fs.h>
#include <linux/pagevec.h>
#include <linux/swap.h>
#include "f2fs.h"
#include "node.h"
#include "segment.h"
#include <trace/events/f2fs.h>
static struct kmem_cache *orphan_entry_slab;
static struct kmem_cache *inode_entry_slab;
/*
* We guarantee no failure on the returned page.
*/
struct page *grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
{
struct address_space *mapping = sbi->meta_inode->i_mapping;
struct page *page = NULL;
repeat:
page = grab_cache_page(mapping, index);
if (!page) {
cond_resched();
goto repeat;
}
/* We wait writeback only inside grab_meta_page() */
wait_on_page_writeback(page);
SetPageUptodate(page);
return page;
}
/*
* We guarantee no failure on the returned page.
*/
struct page *get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
{
struct address_space *mapping = sbi->meta_inode->i_mapping;
struct page *page;
repeat:
page = grab_cache_page(mapping, index);
if (!page) {
cond_resched();
goto repeat;
}
if (PageUptodate(page))
goto out;
if (f2fs_submit_page_bio(sbi, page, index,
READ_SYNC | REQ_META | REQ_PRIO))
goto repeat;
lock_page(page);
if (unlikely(page->mapping != mapping)) {
f2fs_put_page(page, 1);
goto repeat;
}
out:
mark_page_accessed(page);
return page;
}
static int f2fs_write_meta_page(struct page *page,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
/* Should not write any meta pages, if any IO error was occurred */
if (unlikely(sbi->por_doing ||
is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ERROR_FLAG)))
goto redirty_out;
if (wbc->for_reclaim)
goto redirty_out;
wait_on_page_writeback(page);
write_meta_page(sbi, page);
dec_page_count(sbi, F2FS_DIRTY_META);
unlock_page(page);
return 0;
redirty_out:
dec_page_count(sbi, F2FS_DIRTY_META);
wbc->pages_skipped++;
set_page_dirty(page);
return AOP_WRITEPAGE_ACTIVATE;
}
static int f2fs_write_meta_pages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
struct block_device *bdev = sbi->sb->s_bdev;
long written;
if (wbc->for_kupdate)
return 0;
if (get_pages(sbi, F2FS_DIRTY_META) == 0)
return 0;
/* if mounting is failed, skip writing node pages */
mutex_lock(&sbi->cp_mutex);
written = sync_meta_pages(sbi, META, bio_get_nr_vecs(bdev));
mutex_unlock(&sbi->cp_mutex);
wbc->nr_to_write -= written;
return 0;
}
long sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
long nr_to_write)
{
struct address_space *mapping = sbi->meta_inode->i_mapping;
pgoff_t index = 0, end = LONG_MAX;
struct pagevec pvec;
long nwritten = 0;
struct writeback_control wbc = {
.for_reclaim = 0,
};
pagevec_init(&pvec, 0);
while (index <= end) {
int i, nr_pages;
nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
PAGECACHE_TAG_DIRTY,
min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
if (unlikely(nr_pages == 0))
break;
for (i = 0; i < nr_pages; i++) {
struct page *page = pvec.pages[i];
lock_page(page);
f2fs_bug_on(page->mapping != mapping);
f2fs_bug_on(!PageDirty(page));
clear_page_dirty_for_io(page);
if (f2fs_write_meta_page(page, &wbc)) {
unlock_page(page);
break;
}
nwritten++;
if (unlikely(nwritten >= nr_to_write))
break;
}
pagevec_release(&pvec);
cond_resched();
}
if (nwritten)
f2fs_submit_merged_bio(sbi, type, nr_to_write == LONG_MAX,
WRITE);
return nwritten;
}
static int f2fs_set_meta_page_dirty(struct page *page)
{
struct address_space *mapping = page->mapping;
struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
trace_f2fs_set_page_dirty(page, META);
SetPageUptodate(page);
if (!PageDirty(page)) {
__set_page_dirty_nobuffers(page);
inc_page_count(sbi, F2FS_DIRTY_META);
return 1;
}
return 0;
}
const struct address_space_operations f2fs_meta_aops = {
.writepage = f2fs_write_meta_page,
.writepages = f2fs_write_meta_pages,
.set_page_dirty = f2fs_set_meta_page_dirty,
};
int acquire_orphan_inode(struct f2fs_sb_info *sbi)
{
unsigned int max_orphans;
int err = 0;
/*
* considering 512 blocks in a segment 8 blocks are needed for cp
* and log segment summaries. Remaining blocks are used to keep
* orphan entries with the limitation one reserved segment
* for cp pack we can have max 1020*504 orphan entries
*/
max_orphans = (sbi->blocks_per_seg - 2 - NR_CURSEG_TYPE)
* F2FS_ORPHANS_PER_BLOCK;
mutex_lock(&sbi->orphan_inode_mutex);
if (unlikely(sbi->n_orphans >= max_orphans))
err = -ENOSPC;
else
sbi->n_orphans++;
mutex_unlock(&sbi->orphan_inode_mutex);
return err;
}
void release_orphan_inode(struct f2fs_sb_info *sbi)
{
mutex_lock(&sbi->orphan_inode_mutex);
f2fs_bug_on(sbi->n_orphans == 0);
sbi->n_orphans--;
mutex_unlock(&sbi->orphan_inode_mutex);
}
void add_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
{
struct list_head *head, *this;
struct orphan_inode_entry *new = NULL, *orphan = NULL;
mutex_lock(&sbi->orphan_inode_mutex);
head = &sbi->orphan_inode_list;
list_for_each(this, head) {
orphan = list_entry(this, struct orphan_inode_entry, list);
if (orphan->ino == ino)
goto out;
if (orphan->ino > ino)
break;
orphan = NULL;
}
new = f2fs_kmem_cache_alloc(orphan_entry_slab, GFP_ATOMIC);
new->ino = ino;
/* add new_oentry into list which is sorted by inode number */
if (orphan)
list_add(&new->list, this->prev);
else
list_add_tail(&new->list, head);
out:
mutex_unlock(&sbi->orphan_inode_mutex);
}
void remove_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
{
struct list_head *head;
struct orphan_inode_entry *orphan;
mutex_lock(&sbi->orphan_inode_mutex);
head = &sbi->orphan_inode_list;
list_for_each_entry(orphan, head, list) {
if (orphan->ino == ino) {
list_del(&orphan->list);
kmem_cache_free(orphan_entry_slab, orphan);
f2fs_bug_on(sbi->n_orphans == 0);
sbi->n_orphans--;
break;
}
}
mutex_unlock(&sbi->orphan_inode_mutex);
}
static void recover_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
{
struct inode *inode = f2fs_iget(sbi->sb, ino);
f2fs_bug_on(IS_ERR(inode));
clear_nlink(inode);
/* truncate all the data during iput */
iput(inode);
}
void recover_orphan_inodes(struct f2fs_sb_info *sbi)
{
block_t start_blk, orphan_blkaddr, i, j;
if (!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG))
return;
sbi->por_doing = true;
start_blk = __start_cp_addr(sbi) + 1;
orphan_blkaddr = __start_sum_addr(sbi) - 1;
for (i = 0; i < orphan_blkaddr; i++) {
struct page *page = get_meta_page(sbi, start_blk + i);
struct f2fs_orphan_block *orphan_blk;
orphan_blk = (struct f2fs_orphan_block *)page_address(page);
for (j = 0; j < le32_to_cpu(orphan_blk->entry_count); j++) {
nid_t ino = le32_to_cpu(orphan_blk->ino[j]);
recover_orphan_inode(sbi, ino);
}
f2fs_put_page(page, 1);
}
/* clear Orphan Flag */
clear_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG);
sbi->por_doing = false;
return;
}
static void write_orphan_inodes(struct f2fs_sb_info *sbi, block_t start_blk)
{
struct list_head *head;
struct f2fs_orphan_block *orphan_blk = NULL;
struct page *page = NULL;
unsigned int nentries = 0;
unsigned short index = 1;
unsigned short orphan_blocks;
struct orphan_inode_entry *orphan = NULL;
orphan_blocks = (unsigned short)((sbi->n_orphans +
(F2FS_ORPHANS_PER_BLOCK - 1)) / F2FS_ORPHANS_PER_BLOCK);
mutex_lock(&sbi->orphan_inode_mutex);
head = &sbi->orphan_inode_list;
/* loop for each orphan inode entry and write them in Jornal block */
list_for_each_entry(orphan, head, list) {
if (!page) {
page = grab_meta_page(sbi, start_blk);
orphan_blk =
(struct f2fs_orphan_block *)page_address(page);
memset(orphan_blk, 0, sizeof(*orphan_blk));
}
orphan_blk->ino[nentries++] = cpu_to_le32(orphan->ino);
if (nentries == F2FS_ORPHANS_PER_BLOCK) {
/*
* an orphan block is full of 1020 entries,
* then we need to flush current orphan blocks
* and bring another one in memory
*/
orphan_blk->blk_addr = cpu_to_le16(index);
orphan_blk->blk_count = cpu_to_le16(orphan_blocks);
orphan_blk->entry_count = cpu_to_le32(nentries);
set_page_dirty(page);
f2fs_put_page(page, 1);
index++;
start_blk++;
nentries = 0;
page = NULL;
}
}
if (page) {
orphan_blk->blk_addr = cpu_to_le16(index);
orphan_blk->blk_count = cpu_to_le16(orphan_blocks);
orphan_blk->entry_count = cpu_to_le32(nentries);
set_page_dirty(page);
f2fs_put_page(page, 1);
}
mutex_unlock(&sbi->orphan_inode_mutex);
}
static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
block_t cp_addr, unsigned long long *version)
{
struct page *cp_page_1, *cp_page_2 = NULL;
unsigned long blk_size = sbi->blocksize;
struct f2fs_checkpoint *cp_block;
unsigned long long cur_version = 0, pre_version = 0;
size_t crc_offset;
__u32 crc = 0;
/* Read the 1st cp block in this CP pack */
cp_page_1 = get_meta_page(sbi, cp_addr);
/* get the version number */
cp_block = (struct f2fs_checkpoint *)page_address(cp_page_1);
crc_offset = le32_to_cpu(cp_block->checksum_offset);
if (crc_offset >= blk_size)
goto invalid_cp1;
crc = le32_to_cpu(*((__u32 *)((unsigned char *)cp_block + crc_offset)));
if (!f2fs_crc_valid(crc, cp_block, crc_offset))
goto invalid_cp1;
pre_version = cur_cp_version(cp_block);
/* Read the 2nd cp block in this CP pack */
cp_addr += le32_to_cpu(cp_block->cp_pack_total_block_count) - 1;
cp_page_2 = get_meta_page(sbi, cp_addr);
cp_block = (struct f2fs_checkpoint *)page_address(cp_page_2);
crc_offset = le32_to_cpu(cp_block->checksum_offset);
if (crc_offset >= blk_size)
goto invalid_cp2;
crc = le32_to_cpu(*((__u32 *)((unsigned char *)cp_block + crc_offset)));
if (!f2fs_crc_valid(crc, cp_block, crc_offset))
goto invalid_cp2;
cur_version = cur_cp_version(cp_block);
if (cur_version == pre_version) {
*version = cur_version;
f2fs_put_page(cp_page_2, 1);
return cp_page_1;
}
invalid_cp2:
f2fs_put_page(cp_page_2, 1);
invalid_cp1:
f2fs_put_page(cp_page_1, 1);
return NULL;
}
int get_valid_checkpoint(struct f2fs_sb_info *sbi)
{
struct f2fs_checkpoint *cp_block;
struct f2fs_super_block *fsb = sbi->raw_super;
struct page *cp1, *cp2, *cur_page;
unsigned long blk_size = sbi->blocksize;
unsigned long long cp1_version = 0, cp2_version = 0;
unsigned long long cp_start_blk_no;
sbi->ckpt = kzalloc(blk_size, GFP_KERNEL);
if (!sbi->ckpt)
return -ENOMEM;
/*
* Finding out valid cp block involves read both
* sets( cp pack1 and cp pack 2)
*/
cp_start_blk_no = le32_to_cpu(fsb->cp_blkaddr);
cp1 = validate_checkpoint(sbi, cp_start_blk_no, &cp1_version);
/* The second checkpoint pack should start at the next segment */
cp_start_blk_no += ((unsigned long long)1) <<
le32_to_cpu(fsb->log_blocks_per_seg);
cp2 = validate_checkpoint(sbi, cp_start_blk_no, &cp2_version);
if (cp1 && cp2) {
if (ver_after(cp2_version, cp1_version))
cur_page = cp2;
else
cur_page = cp1;
} else if (cp1) {
cur_page = cp1;
} else if (cp2) {
cur_page = cp2;
} else {
goto fail_no_cp;
}
cp_block = (struct f2fs_checkpoint *)page_address(cur_page);
memcpy(sbi->ckpt, cp_block, blk_size);
f2fs_put_page(cp1, 1);
f2fs_put_page(cp2, 1);
return 0;
fail_no_cp:
kfree(sbi->ckpt);
return -EINVAL;
}
static int __add_dirty_inode(struct inode *inode, struct dir_inode_entry *new)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct list_head *head = &sbi->dir_inode_list;
struct list_head *this;
list_for_each(this, head) {
struct dir_inode_entry *entry;
entry = list_entry(this, struct dir_inode_entry, list);
if (unlikely(entry->inode == inode))
return -EEXIST;
}
list_add_tail(&new->list, head);
stat_inc_dirty_dir(sbi);
return 0;
}
void set_dirty_dir_page(struct inode *inode, struct page *page)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct dir_inode_entry *new;
if (!S_ISDIR(inode->i_mode))
return;
new = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
new->inode = inode;
INIT_LIST_HEAD(&new->list);
spin_lock(&sbi->dir_inode_lock);
if (__add_dirty_inode(inode, new))
kmem_cache_free(inode_entry_slab, new);
inc_page_count(sbi, F2FS_DIRTY_DENTS);
inode_inc_dirty_dents(inode);
SetPagePrivate(page);
spin_unlock(&sbi->dir_inode_lock);
}
void add_dirty_dir_inode(struct inode *inode)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct dir_inode_entry *new =
f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
new->inode = inode;
INIT_LIST_HEAD(&new->list);
spin_lock(&sbi->dir_inode_lock);
if (__add_dirty_inode(inode, new))
kmem_cache_free(inode_entry_slab, new);
spin_unlock(&sbi->dir_inode_lock);
}
void remove_dirty_dir_inode(struct inode *inode)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct list_head *this, *head;
if (!S_ISDIR(inode->i_mode))
return;
spin_lock(&sbi->dir_inode_lock);
if (atomic_read(&F2FS_I(inode)->dirty_dents)) {
spin_unlock(&sbi->dir_inode_lock);
return;
}
head = &sbi->dir_inode_list;
list_for_each(this, head) {
struct dir_inode_entry *entry;
entry = list_entry(this, struct dir_inode_entry, list);
if (entry->inode == inode) {
list_del(&entry->list);
kmem_cache_free(inode_entry_slab, entry);
stat_dec_dirty_dir(sbi);
break;
}
}
spin_unlock(&sbi->dir_inode_lock);
/* Only from the recovery routine */
if (is_inode_flag_set(F2FS_I(inode), FI_DELAY_IPUT)) {
clear_inode_flag(F2FS_I(inode), FI_DELAY_IPUT);
iput(inode);
}
}
struct inode *check_dirty_dir_inode(struct f2fs_sb_info *sbi, nid_t ino)
{
struct list_head *this, *head;
struct inode *inode = NULL;
spin_lock(&sbi->dir_inode_lock);
head = &sbi->dir_inode_list;
list_for_each(this, head) {
struct dir_inode_entry *entry;
entry = list_entry(this, struct dir_inode_entry, list);
if (entry->inode->i_ino == ino) {
inode = entry->inode;
break;
}
}
spin_unlock(&sbi->dir_inode_lock);
return inode;
}
void sync_dirty_dir_inodes(struct f2fs_sb_info *sbi)
{
struct list_head *head;
struct dir_inode_entry *entry;
struct inode *inode;
retry:
spin_lock(&sbi->dir_inode_lock);
head = &sbi->dir_inode_list;
if (list_empty(head)) {
spin_unlock(&sbi->dir_inode_lock);
return;
}
entry = list_entry(head->next, struct dir_inode_entry, list);
inode = igrab(entry->inode);
spin_unlock(&sbi->dir_inode_lock);
if (inode) {
filemap_flush(inode->i_mapping);
iput(inode);
} else {
/*
* We should submit bio, since it exists several
* wribacking dentry pages in the freeing inode.
*/
f2fs_submit_merged_bio(sbi, DATA, true, WRITE);
}
goto retry;
}
/*
* Freeze all the FS-operations for checkpoint.
*/
static void block_operations(struct f2fs_sb_info *sbi)
{
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
.nr_to_write = LONG_MAX,
.for_reclaim = 0,
};
f2fs: give a chance to merge IOs by IO scheduler Previously, background GC submits many 4KB read requests to load victim blocks and/or its (i)node blocks. ... f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb61, blkaddr = 0x3b964ed f2fs_gc : block_rq_complete: 8,16 R () 499854968 + 8 [0] f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb6f, blkaddr = 0x3b964ee f2fs_gc : block_rq_complete: 8,16 R () 499854976 + 8 [0] f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb79, blkaddr = 0x3b964ef f2fs_gc : block_rq_complete: 8,16 R () 499854984 + 8 [0] ... However, by the fact that many IOs are sequential, we can give a chance to merge the IOs by IO scheduler. In order to do that, let's use blk_plug. ... f2fs_gc : f2fs_iget: ino = 143 f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c6, blkaddr = 0x2e6ee f2fs_gc : f2fs_iget: ino = 143 f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c7, blkaddr = 0x2e6ef <idle> : block_rq_complete: 8,16 R () 1519616 + 8 [0] <idle> : block_rq_complete: 8,16 R () 1519848 + 8 [0] <idle> : block_rq_complete: 8,16 R () 1520432 + 96 [0] <idle> : block_rq_complete: 8,16 R () 1520536 + 104 [0] <idle> : block_rq_complete: 8,16 R () 1521008 + 112 [0] <idle> : block_rq_complete: 8,16 R () 1521440 + 152 [0] <idle> : block_rq_complete: 8,16 R () 1521688 + 144 [0] <idle> : block_rq_complete: 8,16 R () 1522128 + 192 [0] <idle> : block_rq_complete: 8,16 R () 1523256 + 328 [0] ... Note that this issue should be addressed in checkpoint, and some readahead flows too. Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-24 04:19:56 +00:00
struct blk_plug plug;
blk_start_plug(&plug);
f2fs: introduce a new global lock scheme In the previous version, f2fs uses global locks according to the usage types, such as directory operations, block allocation, block write, and so on. Reference the following lock types in f2fs.h. enum lock_type { RENAME, /* for renaming operations */ DENTRY_OPS, /* for directory operations */ DATA_WRITE, /* for data write */ DATA_NEW, /* for data allocation */ DATA_TRUNC, /* for data truncate */ NODE_NEW, /* for node allocation */ NODE_TRUNC, /* for node truncate */ NODE_WRITE, /* for node write */ NR_LOCK_TYPE, }; In that case, we lose the performance under the multi-threading environment, since every types of operations must be conducted one at a time. In order to address the problem, let's share the locks globally with a mutex array regardless of any types. So, let users grab a mutex and perform their jobs in parallel as much as possbile. For this, I propose a new global lock scheme as follows. 0. Data structure - f2fs_sb_info -> mutex_lock[NR_GLOBAL_LOCKS] - f2fs_sb_info -> node_write 1. mutex_lock_op(sbi) - try to get an avaiable lock from the array. - returns the index of the gottern lock variable. 2. mutex_unlock_op(sbi, index of the lock) - unlock the given index of the lock. 3. mutex_lock_all(sbi) - grab all the locks in the array before the checkpoint. 4. mutex_unlock_all(sbi) - release all the locks in the array after checkpoint. 5. block_operations() - call mutex_lock_all() - sync_dirty_dir_inodes() - grab node_write - sync_node_pages() Note that, the pairs of mutex_lock_op()/mutex_unlock_op() and mutex_lock_all()/mutex_unlock_all() should be used together. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-11-22 07:21:29 +00:00
retry_flush_dents:
f2fs: use rw_sem instead of fs_lock(locks mutex) The fs_locks is used to block other ops(ex, recovery) when doing checkpoint. And each other operate routine(besides checkpoint) needs to acquire a fs_lock, there is a terrible problem here, if these are too many concurrency threads acquiring fs_lock, so that they will block each other and may lead to some performance problem, but this is not the phenomenon we want to see. Though there are some optimization patches introduced to enhance the usage of fs_lock, but the thorough solution is using a *rw_sem* to replace the fs_lock. Checkpoint routine takes write_sem, and other ops take read_sem, so that we can block other ops(ex, recovery) when doing checkpoint, and other ops will not disturb each other, this can avoid the problem described above completely. Because of the weakness of rw_sem, the above change may introduce a potential problem that the checkpoint thread might get starved if other threads are intensively locking the read semaphore for I/O.(Pointed out by Xu Jin) In order to avoid this, a wait_list is introduced, the appending read semaphore ops will be dropped into the wait_list if checkpoint thread is waiting for write semaphore, and will be waked up when checkpoint thread gives up write semaphore. Thanks to Kim's previous review and test, and will be very glad to see other guys' performance tests about this patch. V2: -fix the potential starvation problem. -use more suitable func name suggested by Xu Jin. Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: adjust minor coding standard] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-09-27 10:08:30 +00:00
f2fs_lock_all(sbi);
/* write all the dirty dentry pages */
if (get_pages(sbi, F2FS_DIRTY_DENTS)) {
f2fs: use rw_sem instead of fs_lock(locks mutex) The fs_locks is used to block other ops(ex, recovery) when doing checkpoint. And each other operate routine(besides checkpoint) needs to acquire a fs_lock, there is a terrible problem here, if these are too many concurrency threads acquiring fs_lock, so that they will block each other and may lead to some performance problem, but this is not the phenomenon we want to see. Though there are some optimization patches introduced to enhance the usage of fs_lock, but the thorough solution is using a *rw_sem* to replace the fs_lock. Checkpoint routine takes write_sem, and other ops take read_sem, so that we can block other ops(ex, recovery) when doing checkpoint, and other ops will not disturb each other, this can avoid the problem described above completely. Because of the weakness of rw_sem, the above change may introduce a potential problem that the checkpoint thread might get starved if other threads are intensively locking the read semaphore for I/O.(Pointed out by Xu Jin) In order to avoid this, a wait_list is introduced, the appending read semaphore ops will be dropped into the wait_list if checkpoint thread is waiting for write semaphore, and will be waked up when checkpoint thread gives up write semaphore. Thanks to Kim's previous review and test, and will be very glad to see other guys' performance tests about this patch. V2: -fix the potential starvation problem. -use more suitable func name suggested by Xu Jin. Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: adjust minor coding standard] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-09-27 10:08:30 +00:00
f2fs_unlock_all(sbi);
f2fs: introduce a new global lock scheme In the previous version, f2fs uses global locks according to the usage types, such as directory operations, block allocation, block write, and so on. Reference the following lock types in f2fs.h. enum lock_type { RENAME, /* for renaming operations */ DENTRY_OPS, /* for directory operations */ DATA_WRITE, /* for data write */ DATA_NEW, /* for data allocation */ DATA_TRUNC, /* for data truncate */ NODE_NEW, /* for node allocation */ NODE_TRUNC, /* for node truncate */ NODE_WRITE, /* for node write */ NR_LOCK_TYPE, }; In that case, we lose the performance under the multi-threading environment, since every types of operations must be conducted one at a time. In order to address the problem, let's share the locks globally with a mutex array regardless of any types. So, let users grab a mutex and perform their jobs in parallel as much as possbile. For this, I propose a new global lock scheme as follows. 0. Data structure - f2fs_sb_info -> mutex_lock[NR_GLOBAL_LOCKS] - f2fs_sb_info -> node_write 1. mutex_lock_op(sbi) - try to get an avaiable lock from the array. - returns the index of the gottern lock variable. 2. mutex_unlock_op(sbi, index of the lock) - unlock the given index of the lock. 3. mutex_lock_all(sbi) - grab all the locks in the array before the checkpoint. 4. mutex_unlock_all(sbi) - release all the locks in the array after checkpoint. 5. block_operations() - call mutex_lock_all() - sync_dirty_dir_inodes() - grab node_write - sync_node_pages() Note that, the pairs of mutex_lock_op()/mutex_unlock_op() and mutex_lock_all()/mutex_unlock_all() should be used together. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-11-22 07:21:29 +00:00
sync_dirty_dir_inodes(sbi);
goto retry_flush_dents;
}
/*
* POR: we should ensure that there is no dirty node pages
* until finishing nat/sit flush.
*/
f2fs: introduce a new global lock scheme In the previous version, f2fs uses global locks according to the usage types, such as directory operations, block allocation, block write, and so on. Reference the following lock types in f2fs.h. enum lock_type { RENAME, /* for renaming operations */ DENTRY_OPS, /* for directory operations */ DATA_WRITE, /* for data write */ DATA_NEW, /* for data allocation */ DATA_TRUNC, /* for data truncate */ NODE_NEW, /* for node allocation */ NODE_TRUNC, /* for node truncate */ NODE_WRITE, /* for node write */ NR_LOCK_TYPE, }; In that case, we lose the performance under the multi-threading environment, since every types of operations must be conducted one at a time. In order to address the problem, let's share the locks globally with a mutex array regardless of any types. So, let users grab a mutex and perform their jobs in parallel as much as possbile. For this, I propose a new global lock scheme as follows. 0. Data structure - f2fs_sb_info -> mutex_lock[NR_GLOBAL_LOCKS] - f2fs_sb_info -> node_write 1. mutex_lock_op(sbi) - try to get an avaiable lock from the array. - returns the index of the gottern lock variable. 2. mutex_unlock_op(sbi, index of the lock) - unlock the given index of the lock. 3. mutex_lock_all(sbi) - grab all the locks in the array before the checkpoint. 4. mutex_unlock_all(sbi) - release all the locks in the array after checkpoint. 5. block_operations() - call mutex_lock_all() - sync_dirty_dir_inodes() - grab node_write - sync_node_pages() Note that, the pairs of mutex_lock_op()/mutex_unlock_op() and mutex_lock_all()/mutex_unlock_all() should be used together. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-11-22 07:21:29 +00:00
retry_flush_nodes:
mutex_lock(&sbi->node_write);
if (get_pages(sbi, F2FS_DIRTY_NODES)) {
f2fs: introduce a new global lock scheme In the previous version, f2fs uses global locks according to the usage types, such as directory operations, block allocation, block write, and so on. Reference the following lock types in f2fs.h. enum lock_type { RENAME, /* for renaming operations */ DENTRY_OPS, /* for directory operations */ DATA_WRITE, /* for data write */ DATA_NEW, /* for data allocation */ DATA_TRUNC, /* for data truncate */ NODE_NEW, /* for node allocation */ NODE_TRUNC, /* for node truncate */ NODE_WRITE, /* for node write */ NR_LOCK_TYPE, }; In that case, we lose the performance under the multi-threading environment, since every types of operations must be conducted one at a time. In order to address the problem, let's share the locks globally with a mutex array regardless of any types. So, let users grab a mutex and perform their jobs in parallel as much as possbile. For this, I propose a new global lock scheme as follows. 0. Data structure - f2fs_sb_info -> mutex_lock[NR_GLOBAL_LOCKS] - f2fs_sb_info -> node_write 1. mutex_lock_op(sbi) - try to get an avaiable lock from the array. - returns the index of the gottern lock variable. 2. mutex_unlock_op(sbi, index of the lock) - unlock the given index of the lock. 3. mutex_lock_all(sbi) - grab all the locks in the array before the checkpoint. 4. mutex_unlock_all(sbi) - release all the locks in the array after checkpoint. 5. block_operations() - call mutex_lock_all() - sync_dirty_dir_inodes() - grab node_write - sync_node_pages() Note that, the pairs of mutex_lock_op()/mutex_unlock_op() and mutex_lock_all()/mutex_unlock_all() should be used together. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-11-22 07:21:29 +00:00
mutex_unlock(&sbi->node_write);
sync_node_pages(sbi, 0, &wbc);
goto retry_flush_nodes;
}
f2fs: give a chance to merge IOs by IO scheduler Previously, background GC submits many 4KB read requests to load victim blocks and/or its (i)node blocks. ... f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb61, blkaddr = 0x3b964ed f2fs_gc : block_rq_complete: 8,16 R () 499854968 + 8 [0] f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb6f, blkaddr = 0x3b964ee f2fs_gc : block_rq_complete: 8,16 R () 499854976 + 8 [0] f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb79, blkaddr = 0x3b964ef f2fs_gc : block_rq_complete: 8,16 R () 499854984 + 8 [0] ... However, by the fact that many IOs are sequential, we can give a chance to merge the IOs by IO scheduler. In order to do that, let's use blk_plug. ... f2fs_gc : f2fs_iget: ino = 143 f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c6, blkaddr = 0x2e6ee f2fs_gc : f2fs_iget: ino = 143 f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c7, blkaddr = 0x2e6ef <idle> : block_rq_complete: 8,16 R () 1519616 + 8 [0] <idle> : block_rq_complete: 8,16 R () 1519848 + 8 [0] <idle> : block_rq_complete: 8,16 R () 1520432 + 96 [0] <idle> : block_rq_complete: 8,16 R () 1520536 + 104 [0] <idle> : block_rq_complete: 8,16 R () 1521008 + 112 [0] <idle> : block_rq_complete: 8,16 R () 1521440 + 152 [0] <idle> : block_rq_complete: 8,16 R () 1521688 + 144 [0] <idle> : block_rq_complete: 8,16 R () 1522128 + 192 [0] <idle> : block_rq_complete: 8,16 R () 1523256 + 328 [0] ... Note that this issue should be addressed in checkpoint, and some readahead flows too. Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-24 04:19:56 +00:00
blk_finish_plug(&plug);
}
static void unblock_operations(struct f2fs_sb_info *sbi)
{
f2fs: introduce a new global lock scheme In the previous version, f2fs uses global locks according to the usage types, such as directory operations, block allocation, block write, and so on. Reference the following lock types in f2fs.h. enum lock_type { RENAME, /* for renaming operations */ DENTRY_OPS, /* for directory operations */ DATA_WRITE, /* for data write */ DATA_NEW, /* for data allocation */ DATA_TRUNC, /* for data truncate */ NODE_NEW, /* for node allocation */ NODE_TRUNC, /* for node truncate */ NODE_WRITE, /* for node write */ NR_LOCK_TYPE, }; In that case, we lose the performance under the multi-threading environment, since every types of operations must be conducted one at a time. In order to address the problem, let's share the locks globally with a mutex array regardless of any types. So, let users grab a mutex and perform their jobs in parallel as much as possbile. For this, I propose a new global lock scheme as follows. 0. Data structure - f2fs_sb_info -> mutex_lock[NR_GLOBAL_LOCKS] - f2fs_sb_info -> node_write 1. mutex_lock_op(sbi) - try to get an avaiable lock from the array. - returns the index of the gottern lock variable. 2. mutex_unlock_op(sbi, index of the lock) - unlock the given index of the lock. 3. mutex_lock_all(sbi) - grab all the locks in the array before the checkpoint. 4. mutex_unlock_all(sbi) - release all the locks in the array after checkpoint. 5. block_operations() - call mutex_lock_all() - sync_dirty_dir_inodes() - grab node_write - sync_node_pages() Note that, the pairs of mutex_lock_op()/mutex_unlock_op() and mutex_lock_all()/mutex_unlock_all() should be used together. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-11-22 07:21:29 +00:00
mutex_unlock(&sbi->node_write);
f2fs: use rw_sem instead of fs_lock(locks mutex) The fs_locks is used to block other ops(ex, recovery) when doing checkpoint. And each other operate routine(besides checkpoint) needs to acquire a fs_lock, there is a terrible problem here, if these are too many concurrency threads acquiring fs_lock, so that they will block each other and may lead to some performance problem, but this is not the phenomenon we want to see. Though there are some optimization patches introduced to enhance the usage of fs_lock, but the thorough solution is using a *rw_sem* to replace the fs_lock. Checkpoint routine takes write_sem, and other ops take read_sem, so that we can block other ops(ex, recovery) when doing checkpoint, and other ops will not disturb each other, this can avoid the problem described above completely. Because of the weakness of rw_sem, the above change may introduce a potential problem that the checkpoint thread might get starved if other threads are intensively locking the read semaphore for I/O.(Pointed out by Xu Jin) In order to avoid this, a wait_list is introduced, the appending read semaphore ops will be dropped into the wait_list if checkpoint thread is waiting for write semaphore, and will be waked up when checkpoint thread gives up write semaphore. Thanks to Kim's previous review and test, and will be very glad to see other guys' performance tests about this patch. V2: -fix the potential starvation problem. -use more suitable func name suggested by Xu Jin. Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: adjust minor coding standard] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-09-27 10:08:30 +00:00
f2fs_unlock_all(sbi);
}
static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi)
{
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE);
if (!get_pages(sbi, F2FS_WRITEBACK))
break;
io_schedule();
}
finish_wait(&sbi->cp_wait, &wait);
}
static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
{
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
nid_t last_nid = 0;
block_t start_blk;
struct page *cp_page;
unsigned int data_sum_blocks, orphan_blocks;
__u32 crc32 = 0;
void *kaddr;
int i;
/* Flush all the NAT/SIT pages */
while (get_pages(sbi, F2FS_DIRTY_META))
sync_meta_pages(sbi, META, LONG_MAX);
next_free_nid(sbi, &last_nid);
/*
* modify checkpoint
* version number is already updated
*/
ckpt->elapsed_time = cpu_to_le64(get_mtime(sbi));
ckpt->valid_block_count = cpu_to_le64(valid_user_blocks(sbi));
ckpt->free_segment_count = cpu_to_le32(free_segments(sbi));
for (i = 0; i < 3; i++) {
ckpt->cur_node_segno[i] =
cpu_to_le32(curseg_segno(sbi, i + CURSEG_HOT_NODE));
ckpt->cur_node_blkoff[i] =
cpu_to_le16(curseg_blkoff(sbi, i + CURSEG_HOT_NODE));
ckpt->alloc_type[i + CURSEG_HOT_NODE] =
curseg_alloc_type(sbi, i + CURSEG_HOT_NODE);
}
for (i = 0; i < 3; i++) {
ckpt->cur_data_segno[i] =
cpu_to_le32(curseg_segno(sbi, i + CURSEG_HOT_DATA));
ckpt->cur_data_blkoff[i] =
cpu_to_le16(curseg_blkoff(sbi, i + CURSEG_HOT_DATA));
ckpt->alloc_type[i + CURSEG_HOT_DATA] =
curseg_alloc_type(sbi, i + CURSEG_HOT_DATA);
}
ckpt->valid_node_count = cpu_to_le32(valid_node_count(sbi));
ckpt->valid_inode_count = cpu_to_le32(valid_inode_count(sbi));
ckpt->next_free_nid = cpu_to_le32(last_nid);
/* 2 cp + n data seg summary + orphan inode blocks */
data_sum_blocks = npages_for_summary_flush(sbi);
if (data_sum_blocks < 3)
set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
else
clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
orphan_blocks = (sbi->n_orphans + F2FS_ORPHANS_PER_BLOCK - 1)
/ F2FS_ORPHANS_PER_BLOCK;
ckpt->cp_pack_start_sum = cpu_to_le32(1 + orphan_blocks);
if (is_umount) {
set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
ckpt->cp_pack_total_block_count = cpu_to_le32(2 +
data_sum_blocks + orphan_blocks + NR_CURSEG_NODE_TYPE);
} else {
clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
ckpt->cp_pack_total_block_count = cpu_to_le32(2 +
data_sum_blocks + orphan_blocks);
}
if (sbi->n_orphans)
set_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
else
clear_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
/* update SIT/NAT bitmap */
get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP));
get_nat_bitmap(sbi, __bitmap_ptr(sbi, NAT_BITMAP));
crc32 = f2fs_crc32(ckpt, le32_to_cpu(ckpt->checksum_offset));
*((__le32 *)((unsigned char *)ckpt +
le32_to_cpu(ckpt->checksum_offset)))
= cpu_to_le32(crc32);
start_blk = __start_cp_addr(sbi);
/* write out checkpoint buffer at block 0 */
cp_page = grab_meta_page(sbi, start_blk++);
kaddr = page_address(cp_page);
memcpy(kaddr, ckpt, (1 << sbi->log_blocksize));
set_page_dirty(cp_page);
f2fs_put_page(cp_page, 1);
if (sbi->n_orphans) {
write_orphan_inodes(sbi, start_blk);
start_blk += orphan_blocks;
}
write_data_summaries(sbi, start_blk);
start_blk += data_sum_blocks;
if (is_umount) {
write_node_summaries(sbi, start_blk);
start_blk += NR_CURSEG_NODE_TYPE;
}
/* writeout checkpoint block */
cp_page = grab_meta_page(sbi, start_blk);
kaddr = page_address(cp_page);
memcpy(kaddr, ckpt, (1 << sbi->log_blocksize));
set_page_dirty(cp_page);
f2fs_put_page(cp_page, 1);
/* wait for previous submitted node/meta pages writeback */
wait_on_all_pages_writeback(sbi);
filemap_fdatawait_range(sbi->node_inode->i_mapping, 0, LONG_MAX);
filemap_fdatawait_range(sbi->meta_inode->i_mapping, 0, LONG_MAX);
/* update user_block_counts */
sbi->last_valid_block_count = sbi->total_valid_block_count;
sbi->alloc_valid_block_count = 0;
/* Here, we only have one bio having CP pack */
sync_meta_pages(sbi, META_FLUSH, LONG_MAX);
if (unlikely(!is_set_ckpt_flags(ckpt, CP_ERROR_FLAG))) {
clear_prefree_segments(sbi);
F2FS_RESET_SB_DIRT(sbi);
}
}
/*
* We guarantee that this checkpoint procedure should not fail.
*/
void write_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
{
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
unsigned long long ckpt_ver;
trace_f2fs_write_checkpoint(sbi->sb, is_umount, "start block_ops");
mutex_lock(&sbi->cp_mutex);
block_operations(sbi);
trace_f2fs_write_checkpoint(sbi->sb, is_umount, "finish block_ops");
f2fs_submit_merged_bio(sbi, DATA, true, WRITE);
f2fs_submit_merged_bio(sbi, NODE, true, WRITE);
f2fs_submit_merged_bio(sbi, META, true, WRITE);
/*
* update checkpoint pack index
* Increase the version number so that
* SIT entries and seg summaries are written at correct place
*/
ckpt_ver = cur_cp_version(ckpt);
ckpt->checkpoint_ver = cpu_to_le64(++ckpt_ver);
/* write cached NAT/SIT entries to NAT/SIT area */
flush_nat_entries(sbi);
flush_sit_entries(sbi);
/* unlock all the fs_lock[] in do_checkpoint() */
do_checkpoint(sbi, is_umount);
unblock_operations(sbi);
mutex_unlock(&sbi->cp_mutex);
trace_f2fs_write_checkpoint(sbi->sb, is_umount, "finish checkpoint");
}
void init_orphan_info(struct f2fs_sb_info *sbi)
{
mutex_init(&sbi->orphan_inode_mutex);
INIT_LIST_HEAD(&sbi->orphan_inode_list);
sbi->n_orphans = 0;
}
int __init create_checkpoint_caches(void)
{
orphan_entry_slab = f2fs_kmem_cache_create("f2fs_orphan_entry",
sizeof(struct orphan_inode_entry), NULL);
if (!orphan_entry_slab)
return -ENOMEM;
inode_entry_slab = f2fs_kmem_cache_create("f2fs_dirty_dir_entry",
sizeof(struct dir_inode_entry), NULL);
if (!inode_entry_slab) {
kmem_cache_destroy(orphan_entry_slab);
return -ENOMEM;
}
return 0;
}
void destroy_checkpoint_caches(void)
{
kmem_cache_destroy(orphan_entry_slab);
kmem_cache_destroy(inode_entry_slab);
}