On 13/05/2026 07.47, Christoph Hellwig wrote:
On Tue, May 12, 2026 at 01:42:31PM +0200, David Sterba wrote:
The degenerate modes of
raid0, 5, or 6 are explicit as a possible middle step when converting
profiles. We can use a fallback implementation for this case if the
accelerated implementations cannot do it.
This is not about a degenerated mode. For a degenerated RAID 6, parity
generation uses the RAID 5 XOR routines as the second parity will be
missing. This is about generating two parities for a single data disk,
which must be explicitly selected.
I think that the David concern is : "what happens for an already
existing btrfs raid6 3 disks filesystem when the user upgrade the kernel ?"
(I am thinking when a new BG needs to be allocated)...
BR
GB
--
gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5
