From a95ba66ac1457b76fe472c8e092ab1006271f16c Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Fri, 6 Nov 2020 13:22:05 -0800 Subject: f2fs: avoid race condition for shrinker count Light reported sometimes shinker gets nat_cnt < dirty_nat_cnt resulting in wrong do_shinker work. Let's avoid to return insane overflowed value by adding single tracking value. Reported-by: Light Hsieh Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) (limited to 'fs/f2fs/node.c') diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 42394de6c7eb..e65d73293a3f 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -62,8 +62,8 @@ bool f2fs_available_free_memory(struct f2fs_sb_info *sbi, int type) sizeof(struct free_nid)) >> PAGE_SHIFT; res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2); } else if (type == NAT_ENTRIES) { - mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >> - PAGE_SHIFT; + mem_size = (nm_i->nat_cnt[TOTAL_NAT] * + sizeof(struct nat_entry)) >> PAGE_SHIFT; res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2); if (excess_cached_nats(sbi)) res = false; @@ -177,7 +177,8 @@ static struct nat_entry *__init_nat_entry(struct f2fs_nm_info *nm_i, list_add_tail(&ne->list, &nm_i->nat_entries); spin_unlock(&nm_i->nat_list_lock); - nm_i->nat_cnt++; + nm_i->nat_cnt[TOTAL_NAT]++; + nm_i->nat_cnt[RECLAIMABLE_NAT]++; return ne; } @@ -207,7 +208,8 @@ static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i, static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e) { radix_tree_delete(&nm_i->nat_root, nat_get_nid(e)); - nm_i->nat_cnt--; + nm_i->nat_cnt[TOTAL_NAT]--; + nm_i->nat_cnt[RECLAIMABLE_NAT]--; __free_nat_entry(e); } @@ -253,7 +255,8 @@ static void __set_nat_cache_dirty(struct f2fs_nm_info *nm_i, if (get_nat_flag(ne, IS_DIRTY)) goto refresh_list; - nm_i->dirty_nat_cnt++; + nm_i->nat_cnt[DIRTY_NAT]++; + nm_i->nat_cnt[RECLAIMABLE_NAT]--; set_nat_flag(ne, IS_DIRTY, true); refresh_list: spin_lock(&nm_i->nat_list_lock); @@ -273,7 +276,8 @@ static void __clear_nat_cache_dirty(struct f2fs_nm_info *nm_i, set_nat_flag(ne, IS_DIRTY, false); set->entry_cnt--; - nm_i->dirty_nat_cnt--; + nm_i->nat_cnt[DIRTY_NAT]--; + nm_i->nat_cnt[RECLAIMABLE_NAT]++; } static unsigned int __gang_lookup_nat_set(struct f2fs_nm_info *nm_i, @@ -2944,14 +2948,17 @@ int f2fs_flush_nat_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc) LIST_HEAD(sets); int err = 0; - /* during unmount, let's flush nat_bits before checking dirty_nat_cnt */ + /* + * during unmount, let's flush nat_bits before checking + * nat_cnt[DIRTY_NAT]. + */ if (enabled_nat_bits(sbi, cpc)) { down_write(&nm_i->nat_tree_lock); remove_nats_in_journal(sbi); up_write(&nm_i->nat_tree_lock); } - if (!nm_i->dirty_nat_cnt) + if (!nm_i->nat_cnt[DIRTY_NAT]) return 0; down_write(&nm_i->nat_tree_lock); @@ -2962,7 +2969,8 @@ int f2fs_flush_nat_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc) * into nat entry set. */ if (enabled_nat_bits(sbi, cpc) || - !__has_cursum_space(journal, nm_i->dirty_nat_cnt, NAT_JOURNAL)) + !__has_cursum_space(journal, + nm_i->nat_cnt[DIRTY_NAT], NAT_JOURNAL)) remove_nats_in_journal(sbi); while ((found = __gang_lookup_nat_set(nm_i, @@ -3086,7 +3094,6 @@ static int init_node_manager(struct f2fs_sb_info *sbi) F2FS_RESERVED_NODE_NUM; nm_i->nid_cnt[FREE_NID] = 0; nm_i->nid_cnt[PREALLOC_NID] = 0; - nm_i->nat_cnt = 0; nm_i->ram_thresh = DEF_RAM_THRESHOLD; nm_i->ra_nid_pages = DEF_RA_NID_PAGES; nm_i->dirty_nats_ratio = DEF_DIRTY_NAT_RATIO_THRESHOLD; @@ -3220,7 +3227,7 @@ void f2fs_destroy_node_manager(struct f2fs_sb_info *sbi) __del_from_nat_cache(nm_i, natvec[idx]); } } - f2fs_bug_on(sbi, nm_i->nat_cnt); + f2fs_bug_on(sbi, nm_i->nat_cnt[TOTAL_NAT]); /* destroy nat set cache */ nid = 0; -- cgit v1.2.3