From 27319ba4044c0c67d62ae39e53c0118c89f0a029 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 17 Apr 2018 17:51:28 +0800 Subject: [PATCH] f2fs: fix race in between GC and atomic open Thread GC thread - f2fs_ioc_start_atomic_write - get_dirty_pages - filemap_write_and_wait_range - f2fs_gc - do_garbage_collect - gc_data_segment - move_data_page - f2fs_is_atomic_file - set_page_dirty - set_inode_flag(, FI_ATOMIC_FILE) Dirty data page can still be generated by GC in race condition as above call stack. This patch adds fi->dio_rwsem[WRITE] in f2fs_ioc_start_atomic_write to avoid such race. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/file.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index f639b5fcd66f..18be18907529 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1677,6 +1677,8 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) inode_lock(inode); + down_write(&F2FS_I(inode)->dio_rwsem[WRITE]); + if (f2fs_is_atomic_file(inode)) goto out; @@ -1706,6 +1708,7 @@ inc_stat: stat_inc_atomic_write(inode); stat_update_max_atomic_write(inode); out: + up_write(&F2FS_I(inode)->dio_rwsem[WRITE]); inode_unlock(inode); mnt_drop_write_file(filp); return ret;