From 9e222d7ca5d535d524e92ff303b6f1e61f5ec4d5 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 [ Upstream commit 27319ba4044c0c67d62ae39e53c0118c89f0a029 ] 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/file.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 249f917a494b..7d0e8d6bf009 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1512,6 +1512,8 @@ 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; @@ -1532,6 +1534,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) if (ret) clear_inode_flag(inode, FI_ATOMIC_FILE); out: + up_write(&F2FS_I(inode)->dio_rwsem[WRITE]); inode_unlock(inode); mnt_drop_write_file(filp); return ret; -- 2.20.1