diff options
| author | Chao Yu <yuchao0@huawei.com> | 2016-07-13 09:18:29 +0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-13 12:33:53 +0200 |
| commit | 385e58beee85f04d3f605aefccf429ceed8c2dde (patch) | |
| tree | 9863dfc9ee0d097c5ef61038b6f468890c0d8684 /fs/f2fs/data.c | |
| parent | 4d3d8f7f10e84b7847324d4499a93db0bf6bf002 (diff) | |
f2fs: fix to avoid data update racing between GC and DIO
Datas in file can be operated by GC and DIO simultaneously, so we will
face race case as below:
For write case:
Thread A Thread B
- generic_file_direct_write
- invalidate_inode_pages2_range
- f2fs_direct_IO
- do_blockdev_direct_IO
- do_direct_IO
- get_more_blocks
- f2fs_gc
- do_garbage_collect
- gc_data_segment
- move_data_page
- do_write_data_page
migrate data block to new block address
- dio_bio_submit
update user data to old block address
For read case:
Thread A Thread B
- generic_file_direct_write
- invalidate_inode_pages2_range
- f2fs_direct_IO
- do_blockdev_direct_IO
- do_direct_IO
- get_more_blocks
- f2fs_balance_fs
- f2fs_gc
- do_garbage_collect
- gc_data_segment
- move_data_page
- do_write_data_page
migrate data block to new block address
- write_checkpoint
- do_checkpoint
- clear_prefree_segments
- f2fs_issue_discard
discard old block adress
- dio_bio_submit
update user buffer from obsolete block address
In order to fix this, for one file, we should let DIO and GC getting exclusion
against with each other.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Conflicts:
fs/f2fs/data.c
Diffstat (limited to 'fs/f2fs/data.c')
| -rw-r--r-- | fs/f2fs/data.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index abf836b32..a61750b14 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1756,8 +1756,10 @@ static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb, trace_f2fs_direct_IO_enter(inode, offset, count, rw); + down_read(&F2FS_I(inode)->dio_rwsem[rw]); err = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, get_data_block_dio); + up_read(&F2FS_I(inode)->dio_rwsem[rw]); if (err < 0 && (rw & WRITE)) { if (err > 0) set_inode_flag(inode, FI_UPDATE_WRITE); |