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;
+ }
+
+ 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);
+ }
+ }
+
+ 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
+ ", missing %" PRIuGRUB_UINT64_T "\n",
+ nstripes, failed_devices);
+ ret = GRUB_ERR_READ_ERROR;
+ goto cleanup;
+ }
+ else
+ {
+ grub_dprintf ("btrfs",
+ "enough disks for raid5/6 rebuilding: total %"
+ 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);
+ }
+ else
+ {
+ grub_dprintf ("btrfs", "called rebuild_raid6(), NOT IMPLEMENTED\n");
+ }
+
+cleanup:
+ 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);
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);
- if (err == GRUB_ERR_NONE)
- break;
+ if (err != GRUB_ERR_NONE)
+ err = raid56_read_retry (data, chunk, stripe_offset,
+ stripen, csize, buf);
}
+
if (err == GRUB_ERR_NONE)
break;
}
--
2.17.0
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