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btrfs: Add support for recovery for a RAID 5 btrfs profiles

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Add support for recovery for a RAID 5 btrfs profile. In addition
it is added some code as preparatory work for RAID 6 recovery code.

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Goffredo Baroncelli 2018-10-22 19:29:37 +02:00 committed by Vincent Batts
parent 4725d77e97
commit 979c4ced63
1 changed files with 154 additions and 5 deletions
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159
grub-core/fs/btrfs.c
View file

@ -29,6 +29,7 @@
#include <minilzo.h>
#include <grub/i18n.h>
#include <grub/btrfs.h>
#include <grub/crypto.h>
GRUB_MOD_LICENSE ("GPLv3+");
@ -665,6 +666,138 @@ btrfs_read_from_chunk (struct grub_btrfs_data *data,
return err;
}
struct raid56_buffer {
void *buf;
int data_is_valid;
};
static void
rebuild_raid5 (char *dest, struct raid56_buffer *buffers,
grub_uint64_t nstripes, grub_uint64_t csize)
{
grub_uint64_t i;
int first;
for(i = 0; buffers[i].data_is_valid && i < nstripes; i++);
if (i == nstripes)
{
grub_dprintf ("btrfs", "called rebuild_raid5(), but all disks are OK\n");
return;
}
grub_dprintf ("btrfs", "rebuilding RAID 5 stripe #%" PRIuGRUB_UINT64_T "\n", i);
for (i = 0, first = 1; i < nstripes; i++)
{
if (!buffers[i].data_is_valid)
continue;
if (first) {
grub_memcpy(dest, buffers[i].buf, csize);
first = 0;
} else
grub_crypto_xor (dest, dest, 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 csize, void *buf)
{
struct raid56_buffer *buffers;
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_OUT_OF_MEMORY;
grub_uint64_t i, failed_devices;
buffers = grub_zalloc (sizeof(*buffers) * nstripes);
if (!buffers)
goto cleanup;
for (i = 0; i < nstripes; i++)
{
buffers[i].buf = grub_zalloc (csize);
if (!buffers[i].buf)
goto cleanup;
}
for (failed_devices = 0, i = 0; i < nstripes; i++)
{
struct grub_btrfs_chunk_stripe *stripe;
grub_disk_addr_t paddr;
grub_device_t dev;
grub_err_t err;
/*
* The struct grub_btrfs_chunk_stripe array lives
* behind struct grub_btrfs_chunk_item.
*/
stripe = (struct grub_btrfs_chunk_stripe *) (chunk + 1) + 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)
{
grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " FAILED (dev ID %"
PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
failed_devices++;
continue;
}
err = grub_disk_read (dev->disk, paddr >> GRUB_DISK_SECTOR_BITS,
paddr & (GRUB_DISK_SECTOR_SIZE - 1),
csize, buffers[i].buf);
if (err == 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
{
grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T
" READ FAILED (dev ID %" PRIxGRUB_UINT64_T ")\n",
i, stripe->device_id);
failed_devices++;
}
}
if (failed_devices > 1 && (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5))
{
grub_dprintf ("btrfs", "not enough disks for RAID 5: 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 RAID 5: total %"
PRIuGRUB_UINT64_T ", missing %" PRIuGRUB_UINT64_T "\n",
nstripes, failed_devices);
/* We have enough disks. So, rebuild the data. */
if (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5)
rebuild_raid5 (buf, buffers, nstripes, csize);
else
grub_dprintf ("btrfs", "called rebuild_raid6(), NOT IMPLEMENTED\n");
ret = GRUB_ERR_NONE;
cleanup:
if (buffers)
for (i = 0; i < nstripes; i++)
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)
@ -742,6 +875,10 @@ 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;
is_raid56 = !!(grub_le_to_cpu64 (chunk->type) &
GRUB_BTRFS_CHUNK_TYPE_RAID5);
if (grub_le_to_cpu64 (chunk->size) <= off)
{
@ -921,17 +1058,29 @@ 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)
{
err = btrfs_read_from_chunk (data, chunk, stripen,
stripe_offset,
i, /* redundancy */
0, /* no mirror */
csize, buf);
if (!err)
break;
grub_errno = GRUB_ERR_NONE;
if (err)
err = raid56_read_retry (data, chunk, stripe_offset,
csize, buf);
}
if (i != redundancy)
else
for (i = 0; i < redundancy; i++)
{
err = btrfs_read_from_chunk (data, chunk, stripen,
stripe_offset,
i, /* redundancy */
csize, buf);
if (!err)
break;
grub_errno = GRUB_ERR_NONE;
}
if (!err)
break;
}
if (err)