On Wed, May 16, 2018 at 08:48:17PM +0200, Goffredo Baroncelli wrote:
> Signed-off-by: Goffredo Baroncelli <kreij...@inwind.it>
> ---
> grub-core/fs/btrfs.c | 174 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 170 insertions(+), 4 deletions(-)
>
> diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
> index 63651928b..5fcaad86f 100644
> --- a/grub-core/fs/btrfs.c
> +++ b/grub-core/fs/btrfs.c
> @@ -29,6 +29,7 @@
> #include <minilzo.h>
> #include <grub/i18n.h>
> #include <grub/btrfs.h>
> +#include <grub/crypto.h>
>
> GRUB_MOD_LICENSE ("GPLv3+");
>
> @@ -666,6 +667,150 @@ btrfs_read_from_chunk (struct grub_btrfs_data *data,
> return err;
> }
>
> +struct raid56_buffer {
> + void *buf;
> + int data_is_valid;
> +};
> +
> +static void
> +rebuild_raid5 (struct raid56_buffer *buffers, grub_uint64_t nstripes,
> + grub_uint64_t csize)
> +{
> + grub_uint64_t target = 0, i;
> +
> + while (buffers[target].data_is_valid && target < nstripes)
> + ++target;
> +
> + if (target == nstripes)
> + {
> + grub_dprintf ("btrfs", "called rebuild_raid5(), but all disks are
> OK\n");
> + return;
> + }
> +
> + grub_dprintf ("btrfs", "rebuilding raid5 stripe #%" PRIuGRUB_UINT64_T "\n",
> + target);
> + for (i = 0; i < nstripes; i++)
> + if (i != target)
> + grub_crypto_xor (buffers[target].buf, buffers[target].buf,
> buffers[i].buf,
> + csize);
> +}
> +
> +static grub_err_t
> +raid56_read_retry (struct grub_btrfs_data *data,
> + struct grub_btrfs_chunk_item *chunk,
> + grub_uint64_t stripe_offset, grub_uint64_t stripen,
> + grub_uint64_t csize, void *buf)
> +{
> +
> + struct raid56_buffer *buffers = NULL;
> + grub_uint64_t nstripes = grub_le_to_cpu16 (chunk->nstripes);
> + grub_uint64_t chunk_type = grub_le_to_cpu64 (chunk->type);
> + grub_err_t ret = GRUB_ERR_NONE;
> + grub_uint64_t i, failed_devices;
> +
> + buffers = grub_zalloc (sizeof(*buffers) * nstripes);
> + if (!buffers)
> + {
> + ret = GRUB_ERR_OUT_OF_MEMORY;
> + goto cleanup;
> + }
> +
> + for (i = 0; i < nstripes; i++)
> + {
> + buffers[i].buf = grub_zalloc (csize);
> + if (!buffers[i].buf)
> + {
> + ret = GRUB_ERR_OUT_OF_MEMORY;
> + goto cleanup;
> + }
> + }
> +
> + for (i = 0; i < nstripes; i++)
> + {
> + struct grub_btrfs_chunk_stripe *stripe;
> + grub_disk_addr_t paddr;
> + grub_device_t dev;
> + grub_err_t err2;
> +
> + stripe = (struct grub_btrfs_chunk_stripe *) (chunk + 1);
> + stripe += i;
> +
> + paddr = grub_le_to_cpu64 (stripe->offset) + stripe_offset;
> + grub_dprintf ("btrfs", "reading paddr %" PRIxGRUB_UINT64_T
> + " from stripe ID %" PRIxGRUB_UINT64_T "\n", paddr,
> + stripe->device_id);
> +
> + dev = find_device (data, stripe->device_id);
> + if (!dev)
> + {
> + buffers[i].data_is_valid = 0;
> + grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " FAILED (dev ID
> %"
> + PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
> + continue;
What will happen if more than one stripe is broken?
> + }
> +
> + err2 = grub_disk_read (dev->disk, paddr >> GRUB_DISK_SECTOR_BITS,
> + paddr & (GRUB_DISK_SECTOR_SIZE - 1),
> + csize, buffers[i].buf);
> + if (err2 == GRUB_ERR_NONE)
> + {
> + buffers[i].data_is_valid = 1;
> + grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " Ok (dev ID %"
> + PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
> + }
> + else
> + {
> + buffers[i].data_is_valid = 0;
> + grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T
> + " FAILED (dev ID %" PRIxGRUB_UINT64_T ")\n", i,
> + stripe->device_id);
Ditto?
> + }
> + }
> +
> + failed_devices = 0;
> + for (i = 0; i < nstripes; i++)
> + if (!buffers[i].data_is_valid)
> + ++failed_devices;
> + if (failed_devices > 1 && (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5))
> + {
> + grub_dprintf ("btrfs",
> + "not enough disks for raid5: total %" PRIuGRUB_UINT64_T
s/raid5/RAID5/ Please fix this and the rest of messages in the other patches.
> + ", missing %" PRIuGRUB_UINT64_T "\n",
> + nstripes, failed_devices);
> + ret = GRUB_ERR_READ_ERROR;
> + goto cleanup;
Ahhh... Here it is! Perfect!
> + }
> + else
> + {
> + grub_dprintf ("btrfs",
> + "enough disks for raid5/6 rebuilding: total %"
s#raid5/6#RAID5# This is the patch for RAID 5. Right?
Please do not mix RAID 5 changes with RAID 6 changes.
> + PRIuGRUB_UINT64_T ", missing %" PRIuGRUB_UINT64_T "\n",
> + nstripes, failed_devices);
> + }
> +
> + /* if these are enough, try to rebuild the data */
> + if (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5)
> + {
> + rebuild_raid5 (buffers, nstripes, csize);
> + grub_memcpy (buf, buffers[stripen].buf, csize);
Hmmm... Do we need this grub_memcpy()? Why rebuild_raid5() could
not fill buf directly? If it is not possible then I think that
grub_memcpy() should be called from rebuild_raid5().
> + }
> + else
> + {
> + grub_dprintf ("btrfs", "called rebuild_raid6(), NOT IMPLEMENTED\n");
> + }
Please drop this curly brackets.
> +
> +cleanup:
Space before the label please.
> + if (buffers)
> + {
> + for (i = 0; i < nstripes; i++)
> + if (buffers[i].buf)
> + grub_free(buffers[i].buf);
> + grub_free(buffers);
> + }
> +
> + return ret;
> +}
> +
> static grub_err_t
> grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr,
> void *buf, grub_size_t size, int recursion_depth)
> @@ -743,6 +888,11 @@ grub_btrfs_read_logical (struct grub_btrfs_data *data,
> grub_disk_addr_t addr,
> grub_uint16_t nstripes;
> unsigned redundancy = 1;
> unsigned i, j;
> + int is_raid56;
> + grub_uint64_t parities_pos = 0;
> +
> + is_raid56 = !!(grub_le_to_cpu64 (chunk->type) &
> + GRUB_BTRFS_CHUNK_TYPE_RAID5);
OK, I would leave this as is. However, I would mention
in the commit message that this patch also do some minor
preparatory work for RAID 6 support.
>
> if (grub_le_to_cpu64 (chunk->size) <= off)
> {
> @@ -885,6 +1035,8 @@ grub_btrfs_read_logical (struct grub_btrfs_data *data,
> grub_disk_addr_t addr,
> * number of disks
> */
> grub_divmod64 (high + stripen, nstripes, &stripen);
> + grub_divmod64 (high + nstripes - nparities, nstripes,
> + &parities_pos);
>
> stripe_offset = low + chunk_stripe_length * high;
> csize = chunk_stripe_length - low;
> @@ -917,15 +1069,29 @@ grub_btrfs_read_logical (struct grub_btrfs_data *data,
> grub_disk_addr_t addr,
> grub_dprintf ("btrfs", "reading laddr 0x%" PRIxGRUB_UINT64_T "\n",
> addr);
>
> - for (i = 0; i < redundancy; i++)
> + if (!is_raid56)
> + {
> + for (i = 0; i < redundancy; i++)
> + {
> + err = btrfs_read_from_chunk (data, chunk, stripen,
> + stripe_offset,
> + i, /* redundancy */
> + csize, buf);
> + if (err == GRUB_ERR_NONE)
> + break;
> + }
> + }
> + else
> {
> err = btrfs_read_from_chunk (data, chunk, stripen,
> stripe_offset,
> - i, /* redundancy */
> + 0, /* no mirror */
> csize, buf);
I do not understand this change... Why?
> - if (err == GRUB_ERR_NONE)
> - break;
> + if (err != GRUB_ERR_NONE)
> + err = raid56_read_retry (data, chunk, stripe_offset,
> + stripen, csize, buf);
I have a feeling that this change is somehow related to my comment
for patch #6.
> }
> +
Drop this change please.
> if (err == GRUB_ERR_NONE)
> break;
> }
Daniel
_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel
