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author | Chao Yu <yuchao0@huawei.com> | 2016-07-13 09:18:29 +0800 |
---|---|---|
committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2016-07-15 15:21:22 -0700 |
commit | 82e0a5aa5ddf794b3e1b21fcd091228736871882 (patch) | |
tree | 4cc2beb40b6756219c2da15a5546ec9772f0ec0e /fs/f2fs/super.c | |
parent | 44a83499dda714d9262a9bf4fdac8c077893c9e6 (diff) | |
download | linux-82e0a5aa5ddf794b3e1b21fcd091228736871882.tar.gz linux-82e0a5aa5ddf794b3e1b21fcd091228736871882.tar.bz2 linux-82e0a5aa5ddf794b3e1b21fcd091228736871882.zip |
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>
Diffstat (limited to 'fs/f2fs/super.c')
-rw-r--r-- | fs/f2fs/super.c | 2 |
1 files changed, 2 insertions, 0 deletions
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; |