{
conf_t *conf = r10_bio->mddev->private;
- /*
- * Wake up any possible resync thread that waits for the device
- * to go idle.
- */
- allow_barrier(conf);
-
put_all_bios(conf, r10_bio);
mempool_free(r10_bio, conf->r10bio_pool);
}
static void raid_end_bio_io(r10bio_t *r10_bio)
{
struct bio *bio = r10_bio->master_bio;
+ int done;
+ conf_t *conf = r10_bio->mddev->private;
- bio_endio(bio,
- test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO);
+ if (bio->bi_phys_segments) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio->bi_phys_segments--;
+ done = (bio->bi_phys_segments == 0);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ } else
+ done = 1;
+ if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ if (done) {
+ bio_endio(bio, 0);
+ /*
+ * Wake up any possible resync thread that waits for the device
+ * to go idle.
+ */
+ allow_barrier(conf);
+ }
free_r10bio(r10_bio);
}
mdname(conf->mddev),
bdevname(conf->mirrors[dev].rdev->bdev, b),
(unsigned long long)r10_bio->sector);
+ set_bit(R10BIO_ReadError, &r10_bio->state);
reschedule_retry(r10_bio);
}
}
* FIXME: possibly should rethink readbalancing and do it differently
* depending on near_copies / far_copies geometry.
*/
-static int read_balance(conf_t *conf, r10bio_t *r10_bio)
+static int read_balance(conf_t *conf, r10bio_t *r10_bio, int *max_sectors)
{
const sector_t this_sector = r10_bio->sector;
int disk, slot;
- const int sectors = r10_bio->sectors;
+ int sectors = r10_bio->sectors;
+ int best_good_sectors;
sector_t new_distance, best_dist;
mdk_rdev_t *rdev;
int do_balance;
raid10_find_phys(conf, r10_bio);
rcu_read_lock();
retry:
+ sectors = r10_bio->sectors;
best_slot = -1;
best_dist = MaxSector;
+ best_good_sectors = 0;
do_balance = 1;
/*
* Check if we can balance. We can balance on the whole
do_balance = 0;
for (slot = 0; slot < conf->copies ; slot++) {
+ sector_t first_bad;
+ int bad_sectors;
+ sector_t dev_sector;
+
if (r10_bio->devs[slot].bio == IO_BLOCKED)
continue;
disk = r10_bio->devs[slot].devnum;
if (!test_bit(In_sync, &rdev->flags))
continue;
+ dev_sector = r10_bio->devs[slot].addr;
+ if (is_badblock(rdev, dev_sector, sectors,
+ &first_bad, &bad_sectors)) {
+ if (best_dist < MaxSector)
+ /* Already have a better slot */
+ continue;
+ if (first_bad <= dev_sector) {
+ /* Cannot read here. If this is the
+ * 'primary' device, then we must not read
+ * beyond 'bad_sectors' from another device.
+ */
+ bad_sectors -= (dev_sector - first_bad);
+ if (!do_balance && sectors > bad_sectors)
+ sectors = bad_sectors;
+ if (best_good_sectors > sectors)
+ best_good_sectors = sectors;
+ } else {
+ sector_t good_sectors =
+ first_bad - dev_sector;
+ if (good_sectors > best_good_sectors) {
+ best_good_sectors = good_sectors;
+ best_slot = slot;
+ }
+ if (!do_balance)
+ /* Must read from here */
+ break;
+ }
+ continue;
+ } else
+ best_good_sectors = sectors;
+
if (!do_balance)
break;
} else
disk = -1;
rcu_read_unlock();
+ *max_sectors = best_good_sectors;
return disk;
}
r10_bio->sector = bio->bi_sector;
r10_bio->state = 0;
+ /* We might need to issue multiple reads to different
+ * devices if there are bad blocks around, so we keep
+ * track of the number of reads in bio->bi_phys_segments.
+ * If this is 0, there is only one r10_bio and no locking
+ * will be needed when the request completes. If it is
+ * non-zero, then it is the number of not-completed requests.
+ */
+ bio->bi_phys_segments = 0;
+ clear_bit(BIO_SEG_VALID, &bio->bi_flags);
+
if (rw == READ) {
/*
* read balancing logic:
*/
- int disk = read_balance(conf, r10_bio);
- int slot = r10_bio->read_slot;
+ int max_sectors;
+ int disk;
+ int slot;
+
+read_again:
+ disk = read_balance(conf, r10_bio, &max_sectors);
+ slot = r10_bio->read_slot;
if (disk < 0) {
raid_end_bio_io(r10_bio);
return 0;
mirror = conf->mirrors + disk;
read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
r10_bio->devs[slot].bio = read_bio;
read_bio->bi_rw = READ | do_sync;
read_bio->bi_private = r10_bio;
- generic_make_request(read_bio);
+ if (max_sectors < r10_bio->sectors) {
+ /* Could not read all from this device, so we will
+ * need another r10_bio.
+ */
+ int sectors_handled;
+
+ sectors_handled = (r10_bio->sectors + max_sectors
+ - bio->bi_sector);
+ r10_bio->sectors = max_sectors;
+ spin_lock_irq(&conf->device_lock);
+ if (bio->bi_phys_segments == 0)
+ bio->bi_phys_segments = 2;
+ else
+ bio->bi_phys_segments++;
+ spin_unlock(&conf->device_lock);
+ /* Cannot call generic_make_request directly
+ * as that will be queued in __generic_make_request
+ * and subsequent mempool_alloc might block
+ * waiting for it. so hand bio over to raid10d.
+ */
+ reschedule_retry(r10_bio);
+
+ r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
+
+ r10_bio->master_bio = bio;
+ r10_bio->sectors = ((bio->bi_size >> 9)
+ - sectors_handled);
+ r10_bio->state = 0;
+ r10_bio->mddev = mddev;
+ r10_bio->sector = bio->bi_sector + sectors_handled;
+ goto read_again;
+ } else
+ generic_make_request(read_bio);
return 0;
}
mdk_rdev_t *rdev;
char b[BDEVNAME_SIZE];
unsigned long do_sync;
+ int max_sectors;
/* we got a read error. Maybe the drive is bad. Maybe just
* the block and we can fix it.
bio = r10_bio->devs[slot].bio;
r10_bio->devs[slot].bio =
mddev->ro ? IO_BLOCKED : NULL;
- mirror = read_balance(conf, r10_bio);
- if (mirror == -1) {
+ mirror = read_balance(conf, r10_bio, &max_sectors);
+ if (mirror == -1 || max_sectors < r10_bio->sectors) {
printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"
" read error for block %llu\n",
mdname(mddev),
sync_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
recovery_request_write(mddev, r10_bio);
- else
+ else if (test_bit(R10BIO_ReadError, &r10_bio->state))
handle_read_error(mddev, r10_bio);
+ else {
+ /* just a partial read to be scheduled from a
+ * separate context
+ */
+ int slot = r10_bio->read_slot;
+ generic_make_request(r10_bio->devs[slot].bio);
+ }
cond_resched();
if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
projects / deliverable / linux.git / blobdiff