in md.c [1619:1802]
static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
{
struct mdp_superblock_1 *sb;
int ret;
sector_t sb_start;
sector_t sectors;
char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
int bmask;
bool spare_disk = true;
/*
* Calculate the position of the superblock in 512byte sectors.
* It is always aligned to a 4K boundary and
* depeding on minor_version, it can be:
* 0: At least 8K, but less than 12K, from end of device
* 1: At start of device
* 2: 4K from start of device.
*/
switch(minor_version) {
case 0:
sb_start = bdev_nr_sectors(rdev->bdev) - 8 * 2;
sb_start &= ~(sector_t)(4*2-1);
break;
case 1:
sb_start = 0;
break;
case 2:
sb_start = 8;
break;
default:
return -EINVAL;
}
rdev->sb_start = sb_start;
/* superblock is rarely larger than 1K, but it can be larger,
* and it is safe to read 4k, so we do that
*/
ret = read_disk_sb(rdev, 4096);
if (ret) return ret;
sb = page_address(rdev->sb_page);
if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
sb->major_version != cpu_to_le32(1) ||
le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
le64_to_cpu(sb->super_offset) != rdev->sb_start ||
(le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
return -EINVAL;
if (calc_sb_1_csum(sb) != sb->sb_csum) {
pr_warn("md: invalid superblock checksum on %s\n",
bdevname(rdev->bdev,b));
return -EINVAL;
}
if (le64_to_cpu(sb->data_size) < 10) {
pr_warn("md: data_size too small on %s\n",
bdevname(rdev->bdev,b));
return -EINVAL;
}
if (sb->pad0 ||
sb->pad3[0] ||
memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
/* Some padding is non-zero, might be a new feature */
return -EINVAL;
rdev->preferred_minor = 0xffff;
rdev->data_offset = le64_to_cpu(sb->data_offset);
rdev->new_data_offset = rdev->data_offset;
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
(le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
if (rdev->sb_size & bmask)
rdev->sb_size = (rdev->sb_size | bmask) + 1;
if (minor_version
&& rdev->data_offset < sb_start + (rdev->sb_size/512))
return -EINVAL;
if (minor_version
&& rdev->new_data_offset < sb_start + (rdev->sb_size/512))
return -EINVAL;
if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
rdev->desc_nr = -1;
else
rdev->desc_nr = le32_to_cpu(sb->dev_number);
if (!rdev->bb_page) {
rdev->bb_page = alloc_page(GFP_KERNEL);
if (!rdev->bb_page)
return -ENOMEM;
}
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
rdev->badblocks.count == 0) {
/* need to load the bad block list.
* Currently we limit it to one page.
*/
s32 offset;
sector_t bb_sector;
__le64 *bbp;
int i;
int sectors = le16_to_cpu(sb->bblog_size);
if (sectors > (PAGE_SIZE / 512))
return -EINVAL;
offset = le32_to_cpu(sb->bblog_offset);
if (offset == 0)
return -EINVAL;
bb_sector = (long long)offset;
if (!sync_page_io(rdev, bb_sector, sectors << 9,
rdev->bb_page, REQ_OP_READ, 0, true))
return -EIO;
bbp = (__le64 *)page_address(rdev->bb_page);
rdev->badblocks.shift = sb->bblog_shift;
for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
u64 bb = le64_to_cpu(*bbp);
int count = bb & (0x3ff);
u64 sector = bb >> 10;
sector <<= sb->bblog_shift;
count <<= sb->bblog_shift;
if (bb + 1 == 0)
break;
if (badblocks_set(&rdev->badblocks, sector, count, 1))
return -EINVAL;
}
} else if (sb->bblog_offset != 0)
rdev->badblocks.shift = 0;
if ((le32_to_cpu(sb->feature_map) &
(MD_FEATURE_PPL | MD_FEATURE_MULTIPLE_PPLS))) {
rdev->ppl.offset = (__s16)le16_to_cpu(sb->ppl.offset);
rdev->ppl.size = le16_to_cpu(sb->ppl.size);
rdev->ppl.sector = rdev->sb_start + rdev->ppl.offset;
}
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RAID0_LAYOUT) &&
sb->level != 0)
return -EINVAL;
/* not spare disk, or LEVEL_MULTIPATH */
if (sb->level == cpu_to_le32(LEVEL_MULTIPATH) ||
(rdev->desc_nr >= 0 &&
rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
(le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL)))
spare_disk = false;
if (!refdev) {
if (!spare_disk)
ret = 1;
else
ret = 0;
} else {
__u64 ev1, ev2;
struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
sb->level != refsb->level ||
sb->layout != refsb->layout ||
sb->chunksize != refsb->chunksize) {
pr_warn("md: %s has strangely different superblock to %s\n",
bdevname(rdev->bdev,b),
bdevname(refdev->bdev,b2));
return -EINVAL;
}
ev1 = le64_to_cpu(sb->events);
ev2 = le64_to_cpu(refsb->events);
if (!spare_disk && ev1 > ev2)
ret = 1;
else
ret = 0;
}
if (minor_version)
sectors = bdev_nr_sectors(rdev->bdev) - rdev->data_offset;
else
sectors = rdev->sb_start;
if (sectors < le64_to_cpu(sb->data_size))
return -EINVAL;
rdev->sectors = le64_to_cpu(sb->data_size);
return ret;
}