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 Signed-off-by: Chao Yu <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]> --- 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 4b441cadd2ba..0a1ea59c9d31 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -332,9 +332,6 @@ 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); @@ -1818,7 +1815,7 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid) } 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); @@ -1832,12 +1829,14 @@ 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, @@ -1866,7 +1865,7 @@ 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); } } @@ -1914,58 +1913,6 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi) 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); @@ -1987,21 +1934,6 @@ 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 */ @@ -2088,7 +2020,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid) __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; @@ -2144,7 +2076,7 @@ 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); @@ -2474,11 +2406,11 @@ 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); } } @@ -2584,6 +2516,40 @@ 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); @@ -2685,6 +2651,9 @@ 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; } -- 2.8.2.295.g3f1c1d0
