From 720037f939fa50fc3531035ae61b4cf4b0ff35e5 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Mon, 6 Mar 2017 11:59:56 -0800 Subject: [PATCH 1/5] f2fs: don't overwrite node block by SSR This patch fixes that SSR can overwrite previous warm node block consisting of a node chain since the last checkpoint. Fixes: 5b6c6be2d878 ("f2fs: use SSR for warm node as well") Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/segment.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 4bd7a8b19332..29ef7088c558 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -1163,6 +1163,12 @@ static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del) if (f2fs_discard_en(sbi) && !f2fs_test_and_set_bit(offset, se->discard_map)) sbi->discard_blks--; + + /* don't overwrite by SSR to keep node chain */ + if (se->type == CURSEG_WARM_NODE) { + if (!f2fs_test_and_set_bit(offset, se->ckpt_valid_map)) + se->ckpt_valid_blocks++; + } } else { if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map)) { #ifdef CONFIG_F2FS_CHECK_FS From 9f7e4a2c49fd166f17cf4125766a68dce8716764 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Fri, 10 Mar 2017 09:39:57 -0800 Subject: [PATCH 2/5] f2fs: declare static functions This is to avoid build warning reported by kbuild test robot. Signed-off-by: Fengguang Wu Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 94967171dee8..a0a060c2979b 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1823,7 +1823,8 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid) kmem_cache_free(free_nid_slab, i); } -void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set) +static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, + bool set) { struct f2fs_nm_info *nm_i = NM_I(sbi); unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid); @@ -2383,7 +2384,7 @@ add_out: list_add_tail(&nes->set_list, head); } -void __update_nat_bits(struct f2fs_sb_info *sbi, nid_t start_nid, +static 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); @@ -2638,7 +2639,7 @@ static int init_node_manager(struct f2fs_sb_info *sbi) return 0; } -int init_free_nid_cache(struct f2fs_sb_info *sbi) +static int init_free_nid_cache(struct f2fs_sb_info *sbi) { struct f2fs_nm_info *nm_i = NM_I(sbi); From 23380b8568b85cd4b7a056891f4dbf131f7b871d Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Tue, 7 Mar 2017 14:11:06 -0800 Subject: [PATCH 3/5] f2fs: use __set{__clear}_bit_le This patch uses __set{__clear}_bit_le for highter speed. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/dir.c | 2 +- fs/f2fs/node.c | 18 +++++++++--------- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 4650c9b85de7..8d5c62b07b28 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -750,7 +750,7 @@ void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page, dentry_blk = page_address(page); bit_pos = dentry - dentry_blk->dentry; for (i = 0; i < slots; i++) - clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap); + __clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap); /* Let's check and deallocate this dentry page */ bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index a0a060c2979b..8c81ff614d1a 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -339,7 +339,7 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni, __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); + __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) @@ -1834,9 +1834,9 @@ static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, return; if (set) - set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); + __set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); else - clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); + __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); } static void scan_nat_page(struct f2fs_sb_info *sbi, @@ -1848,7 +1848,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid); int i; - set_bit_le(nat_ofs, nm_i->nat_block_bitmap); + __set_bit_le(nat_ofs, nm_i->nat_block_bitmap); i = start_nid % NAT_ENTRY_PER_BLOCK; @@ -2403,16 +2403,16 @@ static void __update_nat_bits(struct f2fs_sb_info *sbi, nid_t start_nid, valid++; } if (valid == 0) { - set_bit_le(nat_index, nm_i->empty_nat_bits); - clear_bit_le(nat_index, nm_i->full_nat_bits); + __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); + __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); + __set_bit_le(nat_index, nm_i->full_nat_bits); else - clear_bit_le(nat_index, nm_i->full_nat_bits); + __clear_bit_le(nat_index, nm_i->full_nat_bits); } static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, From 586d1492f301982e349797cfb05d9f343002ffa2 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Wed, 1 Mar 2017 17:09:07 +0800 Subject: [PATCH 4/5] f2fs: skip scanning free nid bitmap of full NAT blocks This patch adds to account free nids for each NAT blocks, and while scanning all free nid bitmap, do check count and skip lookuping in full NAT block. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/debug.c | 1 + fs/f2fs/f2fs.h | 2 ++ fs/f2fs/node.c | 33 +++++++++++++++++++++++++++------ 3 files changed, 30 insertions(+), 6 deletions(-) diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c index a77df377e2e8..ee2d0a485fc3 100644 --- a/fs/f2fs/debug.c +++ b/fs/f2fs/debug.c @@ -196,6 +196,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi) si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS); si->base_mem += NM_I(sbi)->nat_blocks * NAT_ENTRY_BITMAP_SIZE; si->base_mem += NM_I(sbi)->nat_blocks / 8; + si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short); get_cache: si->cache_mem = 0; diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index e849f83d6114..0a6e115562f6 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -561,6 +561,8 @@ struct f2fs_nm_info { struct mutex build_lock; /* lock for build free nids */ unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE]; unsigned char *nat_block_bitmap; + unsigned short *free_nid_count; /* free nid count of NAT block */ + spinlock_t free_nid_lock; /* protect updating of nid count */ /* for checkpoint */ char *nat_bitmap; /* NAT bitmap pointer */ diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 8c81ff614d1a..87a2b1f740cc 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1824,7 +1824,7 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid) } static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, - bool set) + bool set, bool build) { struct f2fs_nm_info *nm_i = NM_I(sbi); unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid); @@ -1837,6 +1837,13 @@ static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, __set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); else __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); + + spin_lock(&nm_i->free_nid_lock); + if (set) + nm_i->free_nid_count[nat_ofs]++; + else if (!build) + nm_i->free_nid_count[nat_ofs]--; + spin_unlock(&nm_i->free_nid_lock); } static void scan_nat_page(struct f2fs_sb_info *sbi, @@ -1848,6 +1855,9 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid); int i; + if (test_bit_le(nat_ofs, nm_i->nat_block_bitmap)) + return; + __set_bit_le(nat_ofs, nm_i->nat_block_bitmap); i = start_nid % NAT_ENTRY_PER_BLOCK; @@ -1862,7 +1872,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, f2fs_bug_on(sbi, blk_addr == NEW_ADDR); if (blk_addr == NULL_ADDR) freed = add_free_nid(sbi, start_nid, true); - update_free_nid_bitmap(sbi, start_nid, freed); + update_free_nid_bitmap(sbi, start_nid, freed, true); } } @@ -1878,6 +1888,8 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi) for (i = 0; i < nm_i->nat_blocks; i++) { if (!test_bit_le(i, nm_i->nat_block_bitmap)) continue; + if (!nm_i->free_nid_count[i]) + continue; for (idx = 0; idx < NAT_ENTRY_PER_BLOCK; idx++) { nid_t nid; @@ -2082,7 +2094,7 @@ retry: __insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false); nm_i->available_nids--; - update_free_nid_bitmap(sbi, *nid, false); + update_free_nid_bitmap(sbi, *nid, false, false); spin_unlock(&nm_i->nid_list_lock); return true; @@ -2138,7 +2150,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid) nm_i->available_nids++; - update_free_nid_bitmap(sbi, nid, true); + update_free_nid_bitmap(sbi, nid, true, false); spin_unlock(&nm_i->nid_list_lock); @@ -2468,11 +2480,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, add_free_nid(sbi, nid, false); spin_lock(&NM_I(sbi)->nid_list_lock); NM_I(sbi)->available_nids++; - update_free_nid_bitmap(sbi, nid, true); + update_free_nid_bitmap(sbi, nid, true, false); spin_unlock(&NM_I(sbi)->nid_list_lock); } else { spin_lock(&NM_I(sbi)->nid_list_lock); - update_free_nid_bitmap(sbi, nid, false); + update_free_nid_bitmap(sbi, nid, false, false); spin_unlock(&NM_I(sbi)->nid_list_lock); } } @@ -2652,6 +2664,14 @@ static int init_free_nid_cache(struct f2fs_sb_info *sbi) GFP_KERNEL); if (!nm_i->nat_block_bitmap) return -ENOMEM; + + nm_i->free_nid_count = f2fs_kvzalloc(nm_i->nat_blocks * + sizeof(unsigned short), GFP_KERNEL); + if (!nm_i->free_nid_count) + return -ENOMEM; + + spin_lock_init(&nm_i->free_nid_lock); + return 0; } @@ -2731,6 +2751,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi) kvfree(nm_i->nat_block_bitmap); kvfree(nm_i->free_nid_bitmap); + kvfree(nm_i->free_nid_count); kfree(nm_i->nat_bitmap); kfree(nm_i->nat_bits); From 7041d5d286fb54635f540c1bb3b43980ed65513a Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Wed, 8 Mar 2017 20:07:49 +0800 Subject: [PATCH 5/5] f2fs: combine nat_bits and free_nid_bitmap cache MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Both nat_bits cache and free_nid_bitmap cache provide same functionality as a intermediate cache between free nid cache and disk, but with different granularity of indicating free nid range, and different persistence policy. nat_bits cache provides better persistence ability, and free_nid_bitmap provides better granularity. In this patch we combine advantage of both caches, so finally policy of the intermediate cache would be: - init: load free nid status from nat_bits into free_nid_bitmap - lookup: scan free_nid_bitmap before load NAT blocks - update: update free_nid_bitmap in real-time - persistence: udpate and persist nat_bits in checkpoint This patch also resolves performance regression reported by lkp-robot. commit: 4ac912427c4214d8031d9ad6fbc3bc75e71512df ("f2fs: introduce free nid bitmap") d00030cf9cd0bb96fdccc41e33d3c91dcbb672ba ("f2fs: use __set{__clear}_bit_le") 1382c0f3f9d3f936c8bc42ed1591cf7a593ef9f7 ("f2fs: combine nat_bits and free_nid_bitmap cache") 4ac912427c4214d8 d00030cf9cd0bb96fdccc41e33 1382c0f3f9d3f936c8bc42ed15 ---------------- -------------------------- -------------------------- %stddev %change %stddev %change %stddev \ | \ | \ 77863 ± 0% +2.1% 79485 ± 1% +50.8% 117404 ± 0% aim7.jobs-per-min 231.63 ± 0% -2.0% 227.01 ± 1% -33.6% 153.80 ± 0% aim7.time.elapsed_time 231.63 ± 0% -2.0% 227.01 ± 1% -33.6% 153.80 ± 0% aim7.time.elapsed_time.max 896604 ± 0% -0.8% 889221 ± 3% -20.2% 715260 ± 1% aim7.time.involuntary_context_switches 2394 ± 1% +4.6% 2503 ± 1% +3.7% 2481 ± 2% aim7.time.maximum_resident_set_size 6240 ± 0% -1.5% 6145 ± 1% -14.1% 5360 ± 1% aim7.time.system_time 1111357 ± 3% +1.9% 1132509 ± 2% -6.2% 1041932 ± 2% aim7.time.voluntary_context_switches ... Signed-off-by: Chao Yu Tested-by: Xiaolong Ye Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 125 +++++++++++++++++++------------------------------ 1 file changed, 47 insertions(+), 78 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 87a2b1f740cc..481aa8dc79f4 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -338,9 +338,6 @@ 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); @@ -1824,7 +1821,7 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid) } static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, - bool set, bool build) + bool set, bool build, bool locked) { struct f2fs_nm_info *nm_i = NM_I(sbi); unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid); @@ -1838,12 +1835,14 @@ static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, else __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); - spin_lock(&nm_i->free_nid_lock); + if (!locked) + spin_lock(&nm_i->free_nid_lock); if (set) nm_i->free_nid_count[nat_ofs]++; else if (!build) nm_i->free_nid_count[nat_ofs]--; - spin_unlock(&nm_i->free_nid_lock); + if (!locked) + spin_unlock(&nm_i->free_nid_lock); } static void scan_nat_page(struct f2fs_sb_info *sbi, @@ -1872,7 +1871,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, f2fs_bug_on(sbi, blk_addr == NEW_ADDR); if (blk_addr == NULL_ADDR) freed = add_free_nid(sbi, start_nid, true); - update_free_nid_bitmap(sbi, start_nid, freed, true); + update_free_nid_bitmap(sbi, start_nid, freed, true, false); } } @@ -1920,58 +1919,6 @@ out: up_read(&nm_i->nat_tree_lock); } -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 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] >= MAX_FREE_NIDS) - 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] < MAX_FREE_NIDS) { - 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); @@ -1993,21 +1940,6 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount) if (nm_i->nid_cnt[FREE_NID_LIST]) return; - - /* try to find free nids with nat_bits */ - if (!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 */ @@ -2094,7 +2026,7 @@ retry: __insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false); nm_i->available_nids--; - update_free_nid_bitmap(sbi, *nid, false, false); + update_free_nid_bitmap(sbi, *nid, false, false, false); spin_unlock(&nm_i->nid_list_lock); return true; @@ -2150,7 +2082,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid) nm_i->available_nids++; - update_free_nid_bitmap(sbi, nid, true, false); + update_free_nid_bitmap(sbi, nid, true, false, false); spin_unlock(&nm_i->nid_list_lock); @@ -2480,11 +2412,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, add_free_nid(sbi, nid, false); spin_lock(&NM_I(sbi)->nid_list_lock); NM_I(sbi)->available_nids++; - update_free_nid_bitmap(sbi, nid, true, false); + update_free_nid_bitmap(sbi, nid, true, false, false); spin_unlock(&NM_I(sbi)->nid_list_lock); } else { spin_lock(&NM_I(sbi)->nid_list_lock); - update_free_nid_bitmap(sbi, nid, false, false); + update_free_nid_bitmap(sbi, nid, false, false, false); spin_unlock(&NM_I(sbi)->nid_list_lock); } } @@ -2590,6 +2522,40 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi) return 0; } +inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi) +{ + struct f2fs_nm_info *nm_i = NM_I(sbi); + unsigned int i = 0; + nid_t nid, last_nid; + + if (!enabled_nat_bits(sbi, NULL)) + return; + + for (i = 0; i < nm_i->nat_blocks; i++) { + i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i); + if (i >= nm_i->nat_blocks) + break; + + __set_bit_le(i, nm_i->nat_block_bitmap); + + nid = i * NAT_ENTRY_PER_BLOCK; + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK; + + spin_lock(&nm_i->free_nid_lock); + for (; nid < last_nid; nid++) + update_free_nid_bitmap(sbi, nid, true, true, true); + spin_unlock(&nm_i->free_nid_lock); + } + + for (i = 0; i < nm_i->nat_blocks; i++) { + i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i); + if (i >= nm_i->nat_blocks) + break; + + __set_bit_le(i, nm_i->nat_block_bitmap); + } +} + static int init_node_manager(struct f2fs_sb_info *sbi) { struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi); @@ -2691,6 +2657,9 @@ int build_node_manager(struct f2fs_sb_info *sbi) if (err) return err; + /* load free nid status from nat_bits table */ + load_free_nid_bitmap(sbi); + build_free_nids(sbi, true, true); return 0; }