Re: [PATCH 04/10] btrfs: tree-checker: use table values for stripe checks

[David Sterba <dsterba@suse.cz>]

On Mon, Jul 26, 2021 at 08:29:25PM +0800, Qu Wenruo wrote:
> 
> 
> On 2021/7/26 下午8:15, David Sterba wrote:
> > There are hardcoded values in several checks regarding chunks and stripe
> > constraints. We have that defined in the raid table and ought to use it.
> >
> > Signed-off-by: David Sterba <dsterba@suse.com>
> 
> Reviewed-by: Qu Wenruo <wqu@suse.com>
> 
> But one weird off-topics inlined below.
> 
> > ---
> >   fs/btrfs/tree-checker.c | 17 +++++++++++------
> >   1 file changed, 11 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> > index a8b2e0d2c025..ac9416cb4496 100644
> > --- a/fs/btrfs/tree-checker.c
> > +++ b/fs/btrfs/tree-checker.c
> > @@ -873,13 +873,18 @@ int btrfs_check_chunk_valid(struct extent_buffer *leaf,
> >   		}
> >   	}
> >
> > -	if (unlikely((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) ||
> > -		     (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes != 2) ||
> > -		     (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
> > -		     (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
> > -		     (type & BTRFS_BLOCK_GROUP_DUP && num_stripes != 2) ||
> > +	if (unlikely((type & BTRFS_BLOCK_GROUP_RAID10 &&
> > +		      sub_stripes != btrfs_raid_array[BTRFS_RAID_RAID10].sub_stripes) ||
> > +		     (type & BTRFS_BLOCK_GROUP_RAID1 &&
> > +		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1].devs_min) ||
> 
> We're adding support for single device RAID0, but there won't be
> anything called single device RAID1 at all, right?

Raid 1 with one device can only work in degraded mode so that's
different, it still expects at least 2 devices.