f2fs: add bitmaps for empty or full NAT blocks

This patches adds bitmaps to represent empty or full NAT blocks containing
free nid entries.

If we can find valid crc|cp_ver in the last block of checkpoint pack, we'll
use these bitmaps when building free nids. In order to avoid checkpointing
burden, up-to-date bitmaps will be flushed only during umount time. So,
normally we can get this gain, but when power-cut happens, we rely on fsck.f2fs
which recovers this bitmap again.

After this patch, we build free nids from nid #0 at mount time to make more
full NAT blocks, but in runtime, we check empty NAT blocks to load free nids
without loading any NAT pages from disk.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2017-02-09 10:38:09 -08:00
parent 5e8256ac2e
commit 22ad0b6ab4
6 changed files with 231 additions and 20 deletions

View File

@ -1024,6 +1024,10 @@ static void update_ckpt_flags(struct f2fs_sb_info *sbi, struct cp_control *cpc)
spin_lock(&sbi->cp_lock);
if (cpc->reason == CP_UMOUNT && ckpt->cp_pack_total_block_count >
sbi->blocks_per_seg - NM_I(sbi)->nat_bits_blocks)
disable_nat_bits(sbi, false);
if (cpc->reason == CP_UMOUNT)
__set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
else
@ -1136,6 +1140,28 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
start_blk = __start_cp_next_addr(sbi);
/* write nat bits */
if (enabled_nat_bits(sbi, cpc)) {
__u64 cp_ver = cur_cp_version(ckpt);
unsigned int i;
block_t blk;
cp_ver |= ((__u64)crc32 << 32);
*(__le64 *)nm_i->nat_bits = cpu_to_le64(cp_ver);
blk = start_blk + sbi->blocks_per_seg - nm_i->nat_bits_blocks;
for (i = 0; i < nm_i->nat_bits_blocks; i++)
update_meta_page(sbi, nm_i->nat_bits +
(i << F2FS_BLKSIZE_BITS), blk + i);
/* Flush all the NAT BITS pages */
while (get_pages(sbi, F2FS_DIRTY_META)) {
sync_meta_pages(sbi, META, LONG_MAX);
if (unlikely(f2fs_cp_error(sbi)))
return -EIO;
}
}
/* need to wait for end_io results */
wait_on_all_pages_writeback(sbi);
if (unlikely(f2fs_cp_error(sbi)))
@ -1272,7 +1298,7 @@ int write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
ckpt->checkpoint_ver = cpu_to_le64(++ckpt_ver);
/* write cached NAT/SIT entries to NAT/SIT area */
flush_nat_entries(sbi);
flush_nat_entries(sbi, cpc);
flush_sit_entries(sbi, cpc);
/* unlock all the fs_lock[] in do_checkpoint() */

View File

@ -193,6 +193,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
/* build nm */
si->base_mem += sizeof(struct f2fs_nm_info);
si->base_mem += __bitmap_size(sbi, NAT_BITMAP);
si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS);
get_cache:
si->cache_mem = 0;

View File

@ -554,6 +554,7 @@ struct f2fs_nm_info {
struct list_head nat_entries; /* cached nat entry list (clean) */
unsigned int nat_cnt; /* the # of cached nat entries */
unsigned int dirty_nat_cnt; /* total num of nat entries in set */
unsigned int nat_blocks; /* # of nat blocks */
/* free node ids management */
struct radix_tree_root free_nid_root;/* root of the free_nid cache */
@ -564,6 +565,11 @@ struct f2fs_nm_info {
/* for checkpoint */
char *nat_bitmap; /* NAT bitmap pointer */
unsigned int nat_bits_blocks; /* # of nat bits blocks */
unsigned char *nat_bits; /* NAT bits blocks */
unsigned char *full_nat_bits; /* full NAT pages */
unsigned char *empty_nat_bits; /* empty NAT pages */
#ifdef CONFIG_F2FS_CHECK_FS
char *nat_bitmap_mir; /* NAT bitmap mirror */
#endif
@ -1171,6 +1177,27 @@ static inline void clear_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
spin_unlock(&sbi->cp_lock);
}
static inline void disable_nat_bits(struct f2fs_sb_info *sbi, bool lock)
{
set_sbi_flag(sbi, SBI_NEED_FSCK);
if (lock)
spin_lock(&sbi->cp_lock);
__clear_ckpt_flags(F2FS_CKPT(sbi), CP_NAT_BITS_FLAG);
kfree(NM_I(sbi)->nat_bits);
NM_I(sbi)->nat_bits = NULL;
if (lock)
spin_unlock(&sbi->cp_lock);
}
static inline bool enabled_nat_bits(struct f2fs_sb_info *sbi,
struct cp_control *cpc)
{
bool set = is_set_ckpt_flags(sbi, CP_NAT_BITS_FLAG);
return (cpc) ? (cpc->reason == CP_UMOUNT) && set : set;
}
static inline void f2fs_lock_op(struct f2fs_sb_info *sbi)
{
down_read(&sbi->cp_rwsem);
@ -2131,7 +2158,7 @@ void move_node_page(struct page *node_page, int gc_type);
int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
struct writeback_control *wbc, bool atomic);
int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc);
void build_free_nids(struct f2fs_sb_info *sbi, bool sync);
void build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount);
bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid);
void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid);
void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid);
@ -2142,7 +2169,7 @@ int recover_xattr_data(struct inode *inode, struct page *page,
int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page);
int restore_node_summary(struct f2fs_sb_info *sbi,
unsigned int segno, struct f2fs_summary_block *sum);
void flush_nat_entries(struct f2fs_sb_info *sbi);
void flush_nat_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc);
int build_node_manager(struct f2fs_sb_info *sbi);
void destroy_node_manager(struct f2fs_sb_info *sbi);
int __init create_node_manager_caches(void);

View File

@ -338,6 +338,9 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
set_nat_flag(e, IS_CHECKPOINTED, false);
__set_nat_cache_dirty(nm_i, e);
if (enabled_nat_bits(sbi, NULL) && new_blkaddr == NEW_ADDR)
clear_bit_le(NAT_BLOCK_OFFSET(ni->nid), nm_i->empty_nat_bits);
/* update fsync_mark if its inode nat entry is still alive */
if (ni->nid != ni->ino)
e = __lookup_nat_cache(nm_i, ni->ino);
@ -1841,7 +1844,60 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
}
}
static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync)
static int scan_nat_bits(struct f2fs_sb_info *sbi)
{
struct f2fs_nm_info *nm_i = NM_I(sbi);
struct page *page;
unsigned int i = 0;
nid_t target = FREE_NID_PAGES * NAT_ENTRY_PER_BLOCK;
nid_t nid;
if (!enabled_nat_bits(sbi, NULL))
return -EAGAIN;
down_read(&nm_i->nat_tree_lock);
check_empty:
i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
if (i >= nm_i->nat_blocks) {
i = 0;
goto check_partial;
}
for (nid = i * NAT_ENTRY_PER_BLOCK; nid < (i + 1) * NAT_ENTRY_PER_BLOCK;
nid++) {
if (unlikely(nid >= nm_i->max_nid))
break;
add_free_nid(sbi, nid, true);
}
if (nm_i->nid_cnt[FREE_NID_LIST] >= target)
goto out;
i++;
goto check_empty;
check_partial:
i = find_next_zero_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
if (i >= nm_i->nat_blocks) {
disable_nat_bits(sbi, true);
up_read(&nm_i->nat_tree_lock);
return -EINVAL;
}
nid = i * NAT_ENTRY_PER_BLOCK;
page = get_current_nat_page(sbi, nid);
scan_nat_page(sbi, page, nid);
f2fs_put_page(page, 1);
if (nm_i->nid_cnt[FREE_NID_LIST] < target) {
i++;
goto check_partial;
}
out:
up_read(&nm_i->nat_tree_lock);
return 0;
}
static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
{
struct f2fs_nm_info *nm_i = NM_I(sbi);
struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
@ -1856,6 +1912,21 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync)
if (!sync && !available_free_memory(sbi, FREE_NIDS))
return;
/* try to find free nids with nat_bits */
if (!mount && !scan_nat_bits(sbi) && nm_i->nid_cnt[FREE_NID_LIST])
return;
/* find next valid candidate */
if (enabled_nat_bits(sbi, NULL)) {
int idx = find_next_zero_bit_le(nm_i->full_nat_bits,
nm_i->nat_blocks, 0);
if (idx >= nm_i->nat_blocks)
set_sbi_flag(sbi, SBI_NEED_FSCK);
else
nid = idx * NAT_ENTRY_PER_BLOCK;
}
/* readahead nat pages to be scanned */
ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES,
META_NAT, true);
@ -1898,10 +1969,10 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync)
nm_i->ra_nid_pages, META_NAT, false);
}
void build_free_nids(struct f2fs_sb_info *sbi, bool sync)
void build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
{
mutex_lock(&NM_I(sbi)->build_lock);
__build_free_nids(sbi, sync);
__build_free_nids(sbi, sync, mount);
mutex_unlock(&NM_I(sbi)->build_lock);
}
@ -1943,7 +2014,7 @@ retry:
spin_unlock(&nm_i->nid_list_lock);
/* Let's scan nat pages and its caches to get free nids */
build_free_nids(sbi, true);
build_free_nids(sbi, true, false);
goto retry;
}
@ -2235,8 +2306,39 @@ add_out:
list_add_tail(&nes->set_list, head);
}
void __update_nat_bits(struct f2fs_sb_info *sbi, nid_t start_nid,
struct page *page)
{
struct f2fs_nm_info *nm_i = NM_I(sbi);
unsigned int nat_index = start_nid / NAT_ENTRY_PER_BLOCK;
struct f2fs_nat_block *nat_blk = page_address(page);
int valid = 0;
int i;
if (!enabled_nat_bits(sbi, NULL))
return;
for (i = 0; i < NAT_ENTRY_PER_BLOCK; i++) {
if (start_nid == 0 && i == 0)
valid++;
if (nat_blk->entries[i].block_addr)
valid++;
}
if (valid == 0) {
set_bit_le(nat_index, nm_i->empty_nat_bits);
clear_bit_le(nat_index, nm_i->full_nat_bits);
return;
}
clear_bit_le(nat_index, nm_i->empty_nat_bits);
if (valid == NAT_ENTRY_PER_BLOCK)
set_bit_le(nat_index, nm_i->full_nat_bits);
else
clear_bit_le(nat_index, nm_i->full_nat_bits);
}
static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
struct nat_entry_set *set)
struct nat_entry_set *set, struct cp_control *cpc)
{
struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
struct f2fs_journal *journal = curseg->journal;
@ -2251,7 +2353,8 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
* #1, flush nat entries to journal in current hot data summary block.
* #2, flush nat entries to nat page.
*/
if (!__has_cursum_space(journal, set->entry_cnt, NAT_JOURNAL))
if (enabled_nat_bits(sbi, cpc) ||
!__has_cursum_space(journal, set->entry_cnt, NAT_JOURNAL))
to_journal = false;
if (to_journal) {
@ -2291,10 +2394,12 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
}
}
if (to_journal)
if (to_journal) {
up_write(&curseg->journal_rwsem);
else
} else {
__update_nat_bits(sbi, start_nid, page);
f2fs_put_page(page, 1);
}
f2fs_bug_on(sbi, set->entry_cnt);
@ -2305,7 +2410,7 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
/*
* This function is called during the checkpointing process.
*/
void flush_nat_entries(struct f2fs_sb_info *sbi)
void flush_nat_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
{
struct f2fs_nm_info *nm_i = NM_I(sbi);
struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
@ -2326,7 +2431,8 @@ void flush_nat_entries(struct f2fs_sb_info *sbi)
* entries, remove all entries from journal and merge them
* into nat entry set.
*/
if (!__has_cursum_space(journal, nm_i->dirty_nat_cnt, NAT_JOURNAL))
if (cpc->reason == CP_UMOUNT ||
!__has_cursum_space(journal, nm_i->dirty_nat_cnt, NAT_JOURNAL))
remove_nats_in_journal(sbi);
while ((found = __gang_lookup_nat_set(nm_i,
@ -2340,27 +2446,72 @@ void flush_nat_entries(struct f2fs_sb_info *sbi)
/* flush dirty nats in nat entry set */
list_for_each_entry_safe(set, tmp, &sets, set_list)
__flush_nat_entry_set(sbi, set);
__flush_nat_entry_set(sbi, set, cpc);
up_write(&nm_i->nat_tree_lock);
f2fs_bug_on(sbi, nm_i->dirty_nat_cnt);
}
static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
{
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
struct f2fs_nm_info *nm_i = NM_I(sbi);
unsigned int nat_bits_bytes = nm_i->nat_blocks / BITS_PER_BYTE;
unsigned int i;
__u64 cp_ver = cur_cp_version(ckpt);
size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
__u64 crc = le32_to_cpu(*((__le32 *)
((unsigned char *)ckpt + crc_offset)));
block_t nat_bits_addr;
if (!enabled_nat_bits(sbi, NULL))
return 0;
nm_i->nat_bits_blocks = F2FS_BYTES_TO_BLK((nat_bits_bytes << 1) + 8 +
F2FS_BLKSIZE - 1);
nm_i->nat_bits = kzalloc(nm_i->nat_bits_blocks << F2FS_BLKSIZE_BITS,
GFP_KERNEL);
if (!nm_i->nat_bits)
return -ENOMEM;
nat_bits_addr = __start_cp_addr(sbi) + sbi->blocks_per_seg -
nm_i->nat_bits_blocks;
for (i = 0; i < nm_i->nat_bits_blocks; i++) {
struct page *page = get_meta_page(sbi, nat_bits_addr++);
memcpy(nm_i->nat_bits + (i << F2FS_BLKSIZE_BITS),
page_address(page), F2FS_BLKSIZE);
f2fs_put_page(page, 1);
}
cp_ver |= (crc << 32);
if (cpu_to_le64(cp_ver) != *(__le64 *)nm_i->nat_bits) {
disable_nat_bits(sbi, true);
return 0;
}
nm_i->full_nat_bits = nm_i->nat_bits + 8;
nm_i->empty_nat_bits = nm_i->full_nat_bits + nat_bits_bytes;
f2fs_msg(sbi->sb, KERN_NOTICE, "Found nat_bits in checkpoint");
return 0;
}
static int init_node_manager(struct f2fs_sb_info *sbi)
{
struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
struct f2fs_nm_info *nm_i = NM_I(sbi);
unsigned char *version_bitmap;
unsigned int nat_segs, nat_blocks;
unsigned int nat_segs;
int err;
nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
/* segment_count_nat includes pair segment so divide to 2. */
nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks;
nm_i->nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nm_i->nat_blocks;
/* not used nids: 0, node, meta, (and root counted as valid node) */
nm_i->available_nids = nm_i->max_nid - sbi->total_valid_node_count -
@ -2394,6 +2545,10 @@ static int init_node_manager(struct f2fs_sb_info *sbi)
if (!nm_i->nat_bitmap)
return -ENOMEM;
err = __get_nat_bitmaps(sbi);
if (err)
return err;
#ifdef CONFIG_F2FS_CHECK_FS
nm_i->nat_bitmap_mir = kmemdup(version_bitmap, nm_i->bitmap_size,
GFP_KERNEL);
@ -2416,7 +2571,7 @@ int build_node_manager(struct f2fs_sb_info *sbi)
if (err)
return err;
build_free_nids(sbi, true);
build_free_nids(sbi, true, true);
return 0;
}
@ -2475,6 +2630,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
up_write(&nm_i->nat_tree_lock);
kfree(nm_i->nat_bitmap);
kfree(nm_i->nat_bits);
#ifdef CONFIG_F2FS_CHECK_FS
kfree(nm_i->nat_bitmap_mir);
#endif

View File

@ -386,7 +386,7 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
if (!available_free_memory(sbi, FREE_NIDS))
try_to_free_nids(sbi, MAX_FREE_NIDS);
else
build_free_nids(sbi, false);
build_free_nids(sbi, false, false);
if (!is_idle(sbi))
return;

View File

@ -114,6 +114,7 @@ struct f2fs_super_block {
/*
* For checkpoint
*/
#define CP_NAT_BITS_FLAG 0x00000080
#define CP_CRC_RECOVERY_FLAG 0x00000040
#define CP_FASTBOOT_FLAG 0x00000020
#define CP_FSCK_FLAG 0x00000010