Jaegeuk Kim dd11a5df52 f2fs: avoid data race when deciding checkpoin in f2fs_sync_file
When fs utilization is almost full, f2fs_sync_file should do checkpoint if
there is not enough space for roll-forward later. (i.e. space_for_roll_forward)
So, currently we have no lock for sbi->alloc_valid_block_count, resulting in
race condition.

In rare case, we can get -ENOSPC when doing roll-forward which triggers

	if (is_valid_blkaddr(sbi, dest, META_POR)) {
		if (src == NULL_ADDR) {
			err = reserve_new_block(&dn);
			f2fs_bug_on(sbi, err);
			...
		}
		...
	}
in do_recover_data.

So, this patch avoids that situation in advance.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-20 14:53:21 -07:00
..
2016-07-08 10:34:09 -07:00
2016-07-08 10:34:09 -07:00
2016-07-08 10:34:09 -07:00
2016-07-15 15:21:21 -07:00
2016-07-08 10:34:09 -07:00