From 57ed1e95babbd2df33f70eb820c7a9984199557b Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Mon, 9 Mar 2015 11:00:55 +0800 Subject: [PATCH] f2fs: fix unlocked nat set cache operation nm_i->nat_tree_lock is used to sync both the operations of nat entry cache tree and nat set cache tree, however, it isn't held when flush nat entries during checkpoint which lead to potential race, this patch fix it by holding the lock when gang lookup nat set cache and delete item from nat set cache. Signed-off-by: Wanpeng Li Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 4687eae..8ab0cf1 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1830,6 +1830,7 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, struct f2fs_nat_block *nat_blk; struct nat_entry *ne, *cur; struct page *page = NULL; + struct f2fs_nm_info *nm_i = NM_I(sbi); /* * there are two steps to flush nat entries: @@ -1883,7 +1884,9 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, f2fs_bug_on(sbi, set->entry_cnt); + down_write(&nm_i->nat_tree_lock); radix_tree_delete(&NM_I(sbi)->nat_set_root, set->set); + up_write(&nm_i->nat_tree_lock); kmem_cache_free(nat_entry_set_slab, set); } @@ -1911,6 +1914,7 @@ void flush_nat_entries(struct f2fs_sb_info *sbi) if (!__has_cursum_space(sum, nm_i->dirty_nat_cnt, NAT_JOURNAL)) remove_nats_in_journal(sbi); + down_write(&nm_i->nat_tree_lock); while ((found = __gang_lookup_nat_set(nm_i, set_idx, SETVEC_SIZE, setvec))) { unsigned idx; @@ -1919,6 +1923,7 @@ void flush_nat_entries(struct f2fs_sb_info *sbi) __adjust_nat_entry_set(setvec[idx], &sets, MAX_NAT_JENTRIES(sum)); } + up_write(&nm_i->nat_tree_lock); /* flush dirty nats in nat entry set */ list_for_each_entry_safe(set, tmp, &sets, set_list) -- 2.7.4