From: Chao Yu Date: Tue, 11 Oct 2016 14:31:34 +0000 (+0800) Subject: f2fs: exclude free nids building and allocation X-Git-Tag: android-x86-8.1-r1~4535^2~64 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=2411cf5befa5804e4ced4c45a3212d7653869286;p=android-x86%2Fkernel.git f2fs: exclude free nids building and allocation During nid allocation, it needs to exclude building and allocating flow of free nids, this is because while building free nid cache, there are two steps: a) load free nids from unused nat entries in NAT pages, b) update free nid cache by checking nat journal. The two steps should be atomical, otherwise an used nid can be allocated as free one after a) and before b). This patch adds missing lock which covers build_free_nids in unlock_operation and f2fs_balance_fs_bg to avoid that. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 01177ecdeab8..f12de4589856 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1785,7 +1785,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, } } -void build_free_nids(struct f2fs_sb_info *sbi) +void __build_free_nids(struct f2fs_sb_info *sbi) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA); @@ -1839,6 +1839,13 @@ void build_free_nids(struct f2fs_sb_info *sbi) nm_i->ra_nid_pages, META_NAT, false); } +void build_free_nids(struct f2fs_sb_info *sbi) +{ + mutex_lock(&NM_I(sbi)->build_lock); + __build_free_nids(sbi); + mutex_unlock(&NM_I(sbi)->build_lock); +} + /* * If this function returns success, caller can obtain a new nid * from second parameter of this function. @@ -1875,9 +1882,7 @@ retry: spin_unlock(&nm_i->free_nid_list_lock); /* Let's scan nat pages and its caches to get free nids */ - mutex_lock(&nm_i->build_lock); build_free_nids(sbi); - mutex_unlock(&nm_i->build_lock); goto retry; }