* raid_disks
* near_copies (stored in low byte of layout)
* far_copies (stored in second byte of layout)
+ * far_offset (stored in bit 16 of layout )
*
* The data to be stored is divided into chunks using chunksize.
* Each device is divided into far_copies sections.
* near_copies copies of each chunk is stored (each on a different drive).
* The starting device for each section is offset near_copies from the starting
* device of the previous section.
- * Thus there are (near_copies*far_copies) of each chunk, and each is on a different
+ * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
* drive.
* near_copies and far_copies must be at least one, and their product is at most
* raid_disks.
+ *
+ * If far_offset is true, then the far_copies are handled a bit differently.
+ * The copies are still in different stripes, but instead of be very far apart
+ * on disk, there are adjacent stripes.
*/
/*
* With this layout, and block is never stored twice on the one device.
*
* raid10_find_phys finds the sector offset of a given virtual sector
- * on each device that it is on. If a block isn't on a device,
- * that entry in the array is set to MaxSector.
+ * on each device that it is on.
*
* raid10_find_virt does the reverse mapping, from a device and a
* sector offset to a virtual address
chunk *= conf->near_copies;
stripe = chunk;
dev = sector_div(stripe, conf->raid_disks);
+ if (conf->far_offset)
+ stripe *= conf->far_copies;
sector += stripe << conf->chunk_shift;
{
sector_t offset, chunk, vchunk;
- while (sector > conf->stride) {
- sector -= conf->stride;
- if (dev < conf->near_copies)
- dev += conf->raid_disks - conf->near_copies;
- else
- dev -= conf->near_copies;
- }
-
offset = sector & conf->chunk_mask;
- chunk = sector >> conf->chunk_shift;
+ if (conf->far_offset) {
+ int fc;
+ chunk = sector >> conf->chunk_shift;
+ fc = sector_div(chunk, conf->far_copies);
+ dev -= fc * conf->near_copies;
+ if (dev < 0)
+ dev += conf->raid_disks;
+ } else {
+ while (sector > conf->stride) {
+ sector -= conf->stride;
+ if (dev < conf->near_copies)
+ dev += conf->raid_disks - conf->near_copies;
+ else
+ dev -= conf->near_copies;
+ }
+ chunk = sector >> conf->chunk_shift;
+ }
vchunk = chunk * conf->raid_disks + dev;
sector_div(vchunk, conf->near_copies);
return (vchunk << conf->chunk_shift) + offset;
seq_printf(seq, " %dK chunks", mddev->chunk_size/1024);
if (conf->near_copies > 1)
seq_printf(seq, " %d near-copies", conf->near_copies);
- if (conf->far_copies > 1)
- seq_printf(seq, " %d far-copies", conf->far_copies);
-
+ if (conf->far_copies > 1) {
+ if (conf->far_offset)
+ seq_printf(seq, " %d offset-copies", conf->far_copies);
+ else
+ seq_printf(seq, " %d far-copies", conf->far_copies);
+ }
seq_printf(seq, " [%d/%d] [", conf->raid_disks,
conf->working_disks);
for (i = 0; i < conf->raid_disks; i++)
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
+ rcu_read_lock();
do {
int d = r10_bio->devs[sl].devnum;
- rdev = conf->mirrors[d].rdev;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
- test_bit(In_sync, &rdev->flags) &&
- sync_page_io(rdev->bdev,
- r10_bio->devs[sl].addr +
- sect + rdev->data_offset,
- s<<9,
- conf->tmppage, READ))
- success = 1;
- else {
- sl++;
- if (sl == conf->copies)
- sl = 0;
+ test_bit(In_sync, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ success = sync_page_io(rdev->bdev,
+ r10_bio->devs[sl].addr +
+ sect + rdev->data_offset,
+ s<<9,
+ conf->tmppage, READ);
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ if (success)
+ break;
}
+ sl++;
+ if (sl == conf->copies)
+ sl = 0;
} while (!success && sl != r10_bio->read_slot);
+ rcu_read_unlock();
if (success) {
int start = sl;
/* write it back and re-read */
+ rcu_read_lock();
while (sl != r10_bio->read_slot) {
int d;
if (sl==0)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
- rdev = conf->mirrors[d].rdev;
- atomic_add(s, &rdev->corrected_errors);
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
test_bit(In_sync, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ atomic_add(s, &rdev->corrected_errors);
if (sync_page_io(rdev->bdev,
r10_bio->devs[sl].addr +
sect + rdev->data_offset,
s<<9, conf->tmppage, WRITE) == 0)
/* Well, this device is dead */
md_error(mddev, rdev);
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
}
}
sl = start;
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
- rdev = conf->mirrors[d].rdev;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
test_bit(In_sync, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
if (sync_page_io(rdev->bdev,
r10_bio->devs[sl].addr +
sect + rdev->data_offset,
s<<9, conf->tmppage, READ) == 0)
/* Well, this device is dead */
md_error(mddev, rdev);
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
}
}
+ rcu_read_unlock();
} else {
/* Cannot read from anywhere -- bye bye array */
md_error(mddev, conf->mirrors[r10_bio->devs[r10_bio->read_slot].devnum].rdev);
mirror_info_t *disk;
mdk_rdev_t *rdev;
struct list_head *tmp;
- int nc, fc;
+ int nc, fc, fo;
sector_t stride, size;
if (mddev->chunk_size == 0) {
nc = mddev->layout & 255;
fc = (mddev->layout >> 8) & 255;
+ fo = mddev->layout & (1<<16);
if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
- (mddev->layout >> 16)) {
+ (mddev->layout >> 17)) {
printk(KERN_ERR "raid10: %s: unsupported raid10 layout: 0x%8x\n",
mdname(mddev), mddev->layout);
goto out;
conf->near_copies = nc;
conf->far_copies = fc;
conf->copies = nc*fc;
+ conf->far_offset = fo;
conf->chunk_mask = (sector_t)(mddev->chunk_size>>9)-1;
conf->chunk_shift = ffz(~mddev->chunk_size) - 9;
- stride = mddev->size >> (conf->chunk_shift-1);
- sector_div(stride, fc);
- conf->stride = stride << conf->chunk_shift;
-
+ if (fo)
+ conf->stride = 1 << conf->chunk_shift;
+ else {
+ stride = mddev->size >> (conf->chunk_shift-1);
+ sector_div(stride, fc);
+ conf->stride = stride << conf->chunk_shift;
+ }
conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
r10bio_pool_free, conf);
if (!conf->r10bio_pool) {
disk = conf->mirrors + i;
- if (!disk->rdev) {
+ if (!disk->rdev ||
+ !test_bit(In_sync, &rdev->flags)) {
disk->head_position = 0;
mddev->degraded++;
}
/*
* Ok, everything is just fine now
*/
- size = conf->stride * conf->raid_disks;
+ if (conf->far_offset) {
+ size = mddev->size >> (conf->chunk_shift-1);
+ size *= conf->raid_disks;
+ size <<= conf->chunk_shift;
+ sector_div(size, conf->far_copies);
+ } else
+ size = conf->stride * conf->raid_disks;
sector_div(size, conf->near_copies);
mddev->array_size = size/2;
mddev->resync_max_sectors = size;
* maybe...
*/
{
- int stripe = conf->raid_disks * mddev->chunk_size / PAGE_SIZE;
+ int stripe = conf->raid_disks * (mddev->chunk_size / PAGE_SIZE);
stripe /= conf->near_copies;
if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
mddev->queue->backing_dev_info.ra_pages = 2* stripe;
git.openpandora.org / pandora-kernel.git / blobdiff