Re: [PATCH 9/9] btrfs: Add RAID 6 recovery for a btrfs filesystem.

[Daniel Kiper]

On Sun, Jun 03, 2018 at 08:53:48PM +0200, Goffredo Baroncelli wrote:
> Add the RAID 6 recovery, in order to use a RAID 6 filesystem even if some
> disks (up to two) are missing. This code use the md RAID 6 code already
> present in grub.
>
> Signed-off-by: Goffredo Baroncelli <address@hidden>
> ---
>  grub-core/fs/btrfs.c | 50 ++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 44 insertions(+), 6 deletions(-)
>
> diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
> index c8f034641..0b6557ce3 100644
> --- a/grub-core/fs/btrfs.c
> +++ b/grub-core/fs/btrfs.c
> @@ -30,6 +30,7 @@
>  #include <grub/i18n.h>
>  #include <grub/btrfs.h>
>  #include <grub/crypto.h>
> +#include <grub/diskfilter.h>
>
>  GRUB_MOD_LICENSE ("GPLv3+");
>
> @@ -706,11 +707,35 @@ rebuild_raid5 (char *dest, struct raid56_buffer 
> *buffers,
>      }
>  }
>
> +static grub_err_t
> +raid6_recover_read_buffer (void *data, int disk_nr,
> +                        grub_uint64_t addr __attribute__ ((unused)),
> +                        void *dest, grub_size_t size)
> +{
> +    struct raid56_buffer *buffers = data;
> +
> +    grub_memcpy(dest, buffers[disk_nr].buf, size);
> +
> +    grub_errno = buffers[disk_nr].data_is_valid ? GRUB_ERR_NONE :
> +              GRUB_ERR_READ_ERROR;
> +    return grub_errno;

      if (!buffers[disk_nr].data_is_valid)
          return GRUB_ERR_READ_ERROR;

      grub_memcpy(dest, buffers[disk_nr].buf, size);

      return GRUB_ERR_NONE;

Daniel