btrfs: relocation: Check cancel request after each extent found

When relocating data block groups with tons of small extents, or large
metadata block groups, there can be over 200,000 extents.

We will iterate all extents of such block group in relocate_block_group(),
where iteration itself can be kinda time-consuming.

So when user want to cancel the balance, the extent iteration loop can
be another target.

This patch will add the cancelling check in the extent iteration loop of
relocate_block_group() to make balance cancelling faster.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2020-02-17 14:16:54 +08:00 committed by David Sterba
parent 7f913c7cfe
commit f31ea0888c

View File

@ -4232,6 +4232,10 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
break;
}
}
if (btrfs_should_cancel_balance(fs_info)) {
err = -ECANCELED;
break;
}
}
if (trans && progress && err == -ENOSPC) {
ret = btrfs_force_chunk_alloc(trans, rc->block_group->flags);