There is a bug in raid56_recov() which doesn't properly repair data and
P case corruption:
/* Data and P*/
if (dest2 == nr_devs - 1)
return raid6_recov_datap(nr_devs, stripe_len, dest1, data);
Note that, dest1/2 is to indicate which slot has corruption.
For RAID6 cases:
[0, nr_devs - 2) is for data stripes,
@data_devs - 2 is for P,
@data_devs - 1 is for Q.
For above code, the comment is correct, but the check condition is
wrong, and leads to the only project, btrfs-fuse, to report raid6
recovery error for 2 devices missing case.
Fix it by using correct condition.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce a wrapper to recover raid56 data.
The logical is the same with kernel one, but with different interfaces,
since kernel ones cares the performance while in btrfs we don't care
that much.
And the interface is more caller friendly inside btrfs-progs.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Copied from kernel lib/raid6/recov.c.
Minor modifications includes:
- Rename from raid6_datap_recov_intx() to raid5_recov_datap()
- Rename parameter from faila to dest1
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Copied from kernel lib/raid6/recov.c raid6_2data_recov_intx1() function.
With the following modification:
- Rename to raid6_recov_data2() for shorter name
- s/kfree/free/g modification
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
