diff options
| -rw-r--r-- | drivers/md/raid10.c | 45 |
1 files changed, 33 insertions, 12 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index c9a149b2ec86..8a1354a08a1a 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -707,15 +707,19 @@ static struct md_rdev *read_balance(struct r10conf *conf, int sectors = r10_bio->sectors; int best_good_sectors; sector_t new_distance, best_dist; - struct md_rdev *best_rdev, *rdev = NULL; + struct md_rdev *best_dist_rdev, *best_pending_rdev, *rdev = NULL; int do_balance; - int best_slot; + int best_dist_slot, best_pending_slot; + bool has_nonrot_disk = false; + unsigned int min_pending; struct geom *geo = &conf->geo; raid10_find_phys(conf, r10_bio); rcu_read_lock(); - best_slot = -1; - best_rdev = NULL; + best_dist_slot = -1; + min_pending = UINT_MAX; + best_dist_rdev = NULL; + best_pending_rdev = NULL; best_dist = MaxSector; best_good_sectors = 0; do_balance = 1; @@ -737,6 +741,8 @@ static struct md_rdev *read_balance(struct r10conf *conf, sector_t first_bad; int bad_sectors; sector_t dev_sector; + unsigned int pending; + bool nonrot; if (r10_bio->devs[slot].bio == IO_BLOCKED) continue; @@ -773,8 +779,8 @@ static struct md_rdev *read_balance(struct r10conf *conf, first_bad - dev_sector; if (good_sectors > best_good_sectors) { best_good_sectors = good_sectors; - best_slot = slot; - best_rdev = rdev; + best_dist_slot = slot; + best_dist_rdev = rdev; } if (!do_balance) /* Must read from here */ @@ -787,14 +793,23 @@ static struct md_rdev *read_balance(struct r10conf *conf, if (!do_balance) break; - if (best_slot >= 0) + nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev)); + has_nonrot_disk |= nonrot; + pending = atomic_read(&rdev->nr_pending); + if (min_pending > pending && nonrot) { + min_pending = pending; + best_pending_slot = slot; + best_pending_rdev = rdev; + } + + if (best_dist_slot >= 0) /* At least 2 disks to choose from so failfast is OK */ set_bit(R10BIO_FailFast, &r10_bio->state); /* This optimisation is debatable, and completely destroys * sequential read speed for 'far copies' arrays. So only * keep it for 'near' arrays, and review those later. */ - if (geo->near_copies > 1 && !atomic_read(&rdev->nr_pending)) + if (geo->near_copies > 1 && !pending) new_distance = 0; /* for far > 1 always use the lowest address */ @@ -803,15 +818,21 @@ static struct md_rdev *read_balance(struct r10conf *conf, else new_distance = abs(r10_bio->devs[slot].addr - conf->mirrors[disk].head_position); + if (new_distance < best_dist) { best_dist = new_distance; - best_slot = slot; - best_rdev = rdev; + best_dist_slot = slot; + best_dist_rdev = rdev; } } if (slot >= conf->copies) { - slot = best_slot; - rdev = best_rdev; + if (has_nonrot_disk) { + slot = best_pending_slot; + rdev = best_pending_rdev; + } else { + slot = best_dist_slot; + rdev = best_dist_rdev; + } } if (slot >= 0) { |