From 82e0a5aa5ddf794b3e1b21fcd091228736871882 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Wed, 13 Jul 2016 09:18:29 +0800 Subject: 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 Signed-off-by: Jaegeuk Kim --- fs/f2fs/super.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/f2fs/super.c') diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 451dfb4041e8..b97c065cbe74 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -579,6 +579,8 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb) INIT_LIST_HEAD(&fi->gdirty_list); INIT_LIST_HEAD(&fi->inmem_pages); mutex_init(&fi->inmem_lock); + init_rwsem(&fi->dio_rwsem[READ]); + init_rwsem(&fi->dio_rwsem[WRITE]); /* Will be used by directory only */ fi->i_dir_level = F2FS_SB(sb)->dir_level; -- cgit v1.2.3-59-g8ed1b