f2fs: fix race in between GC and atomic open
authorChao Yu <yuchao0@huawei.com>
Tue, 17 Apr 2018 09:51:28 +0000 (17:51 +0800)
committerJaegeuk Kim <jaegeuk@kernel.org>
Thu, 31 May 2018 18:31:46 +0000 (11:31 -0700)
commit27319ba4044c0c67d62ae39e53c0118c89f0a029
treed87c4e0a30ee43eb9219bc18403f359d07d737fd
parentea4d479bb3603726128a06fe8f127a191f1c8a68
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 <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
fs/f2fs/file.c