From 709ae4879ae33628ded276ce7da8cd5acfec476b Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 14 Dec 2009 12:49:51 +1100 Subject: [PATCH] md/raid1: add takeover support for raid5->raid1 A 2-device raid5 array can now be converted to raid1. Signed-off-by: NeilBrown --- drivers/md/raid1.c | 191 ++++++++++++++++++++++++++++++++--------------------- drivers/md/raid1.h | 5 ++ 2 files changed, 120 insertions(+), 76 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 35b2d86..7549b0b 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -677,6 +677,7 @@ static void raise_barrier(conf_t *conf) static void lower_barrier(conf_t *conf) { unsigned long flags; + BUG_ON(conf->barrier <= 0); spin_lock_irqsave(&conf->resync_lock, flags); conf->barrier--; spin_unlock_irqrestore(&conf->resync_lock, flags); @@ -1960,74 +1961,48 @@ static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks) return mddev->dev_sectors; } -static int run(mddev_t *mddev) +static conf_t *setup_conf(mddev_t *mddev) { conf_t *conf; - int i, j, disk_idx; + int i; mirror_info_t *disk; mdk_rdev_t *rdev; + int err = -ENOMEM; - if (mddev->level != 1) { - printk("raid1: %s: raid level not set to mirroring (%d)\n", - mdname(mddev), mddev->level); - goto out; - } - if (mddev->reshape_position != MaxSector) { - printk("raid1: %s: reshape_position set but not supported\n", - mdname(mddev)); - goto out; - } - /* - * copy the already verified devices into our private RAID1 - * bookkeeping area. [whatever we allocate in run(), - * should be freed in stop()] - */ conf = kzalloc(sizeof(conf_t), GFP_KERNEL); - mddev->private = conf; if (!conf) - goto out_no_mem; + goto abort; conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, GFP_KERNEL); if (!conf->mirrors) - goto out_no_mem; + goto abort; conf->tmppage = alloc_page(GFP_KERNEL); if (!conf->tmppage) - goto out_no_mem; + goto abort; - conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL); + conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL); if (!conf->poolinfo) - goto out_no_mem; - conf->poolinfo->mddev = NULL; + goto abort; conf->poolinfo->raid_disks = mddev->raid_disks; conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, r1bio_pool_free, conf->poolinfo); if (!conf->r1bio_pool) - goto out_no_mem; + goto abort; + conf->poolinfo->mddev = mddev; spin_lock_init(&conf->device_lock); - mddev->queue->queue_lock = &conf->device_lock; - list_for_each_entry(rdev, &mddev->disks, same_set) { - disk_idx = rdev->raid_disk; + int disk_idx = rdev->raid_disk; if (disk_idx >= mddev->raid_disks || disk_idx < 0) continue; disk = conf->mirrors + disk_idx; disk->rdev = rdev; - disk_stack_limits(mddev->gendisk, rdev->bdev, - rdev->data_offset << 9); - /* as we don't honour merge_bvec_fn, we must never risk - * violating it, so limit ->max_sector to one PAGE, as - * a one page request is never in violation. - */ - if (rdev->bdev->bd_disk->queue->merge_bvec_fn && - queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9)) - blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); disk->head_position = 0; } @@ -2041,8 +2016,7 @@ static int run(mddev_t *mddev) bio_list_init(&conf->pending_bio_list); bio_list_init(&conf->flushing_bio_list); - - mddev->degraded = 0; + conf->last_used = -1; for (i = 0; i < conf->raid_disks; i++) { disk = conf->mirrors + i; @@ -2050,38 +2024,97 @@ static int run(mddev_t *mddev) if (!disk->rdev || !test_bit(In_sync, &disk->rdev->flags)) { disk->head_position = 0; - mddev->degraded++; if (disk->rdev) conf->fullsync = 1; - } + } else if (conf->last_used < 0) + /* + * The first working device is used as a + * starting point to read balancing. + */ + conf->last_used = i; } - if (mddev->degraded == conf->raid_disks) { + + err = -EIO; + if (conf->last_used < 0) { printk(KERN_ERR "raid1: no operational mirrors for %s\n", - mdname(mddev)); - goto out_free_conf; + mdname(mddev)); + goto abort; + } + err = -ENOMEM; + conf->thread = md_register_thread(raid1d, mddev, NULL); + if (!conf->thread) { + printk(KERN_ERR + "raid1: couldn't allocate thread for %s\n", + mdname(mddev)); + goto abort; } - if (conf->raid_disks - mddev->degraded == 1) - mddev->recovery_cp = MaxSector; + return conf; + + abort: + if (conf) { + if (conf->r1bio_pool) + mempool_destroy(conf->r1bio_pool); + kfree(conf->mirrors); + safe_put_page(conf->tmppage); + kfree(conf->poolinfo); + kfree(conf); + } + return ERR_PTR(err); +} + +static int run(mddev_t *mddev) +{ + conf_t *conf; + int i; + mdk_rdev_t *rdev; + + if (mddev->level != 1) { + printk("raid1: %s: raid level not set to mirroring (%d)\n", + mdname(mddev), mddev->level); + return -EIO; + } + if (mddev->reshape_position != MaxSector) { + printk("raid1: %s: reshape_position set but not supported\n", + mdname(mddev)); + return -EIO; + } /* - * find the first working one and use it as a starting point - * to read balancing. + * copy the already verified devices into our private RAID1 + * bookkeeping area. [whatever we allocate in run(), + * should be freed in stop()] */ - for (j = 0; j < conf->raid_disks && - (!conf->mirrors[j].rdev || - !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++) - /* nothing */; - conf->last_used = j; + if (mddev->private == NULL) + conf = setup_conf(mddev); + else + conf = mddev->private; + if (IS_ERR(conf)) + return PTR_ERR(conf); - mddev->thread = md_register_thread(raid1d, mddev, NULL); - if (!mddev->thread) { - printk(KERN_ERR - "raid1: couldn't allocate thread for %s\n", - mdname(mddev)); - goto out_free_conf; + mddev->queue->queue_lock = &conf->device_lock; + list_for_each_entry(rdev, &mddev->disks, same_set) { + disk_stack_limits(mddev->gendisk, rdev->bdev, + rdev->data_offset << 9); + /* as we don't honour merge_bvec_fn, we must never risk + * violating it, so limit ->max_sector to one PAGE, as + * a one page request is never in violation. + */ + if (rdev->bdev->bd_disk->queue->merge_bvec_fn && + queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9)) + blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); } + mddev->degraded = 0; + for (i=0; i < conf->raid_disks; i++) + if (conf->mirrors[i].rdev == NULL || + !test_bit(In_sync, &conf->mirrors[i].rdev->flags) || + test_bit(Faulty, &conf->mirrors[i].rdev->flags)) + mddev->degraded++; + + if (conf->raid_disks - mddev->degraded == 1) + mddev->recovery_cp = MaxSector; + if (mddev->recovery_cp != MaxSector) printk(KERN_NOTICE "raid1: %s is not clean" " -- starting background reconstruction\n", @@ -2090,9 +2123,14 @@ static int run(mddev_t *mddev) "raid1: raid set %s active with %d out of %d mirrors\n", mdname(mddev), mddev->raid_disks - mddev->degraded, mddev->raid_disks); + /* * Ok, everything is just fine now */ + mddev->thread = conf->thread; + conf->thread = NULL; + mddev->private = conf; + md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); mddev->queue->unplug_fn = raid1_unplug; @@ -2100,23 +2138,6 @@ static int run(mddev_t *mddev) mddev->queue->backing_dev_info.congested_data = mddev; md_integrity_register(mddev); return 0; - -out_no_mem: - printk(KERN_ERR "raid1: couldn't allocate memory for %s\n", - mdname(mddev)); - -out_free_conf: - if (conf) { - if (conf->r1bio_pool) - mempool_destroy(conf->r1bio_pool); - kfree(conf->mirrors); - safe_put_page(conf->tmppage); - kfree(conf->poolinfo); - kfree(conf); - mddev->private = NULL; - } -out: - return -EIO; } static int stop(mddev_t *mddev) @@ -2302,6 +2323,23 @@ static void raid1_quiesce(mddev_t *mddev, int state) } } +static void *raid1_takeover(mddev_t *mddev) +{ + /* raid1 can take over: + * raid5 with 2 devices, any layout or chunk size + */ + if (mddev->level == 5 && mddev->raid_disks == 2) { + conf_t *conf; + mddev->new_level = 1; + mddev->new_layout = 0; + mddev->new_chunk_sectors = 0; + conf = setup_conf(mddev); + if (!IS_ERR(conf)) + conf->barrier = 1; + return conf; + } + return ERR_PTR(-EINVAL); +} static struct mdk_personality raid1_personality = { @@ -2321,6 +2359,7 @@ static struct mdk_personality raid1_personality = .size = raid1_size, .check_reshape = raid1_reshape, .quiesce = raid1_quiesce, + .takeover = raid1_takeover, }; static int __init raid_init(void) diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h index e87b84d..5f2d443 100644 --- a/drivers/md/raid1.h +++ b/drivers/md/raid1.h @@ -59,6 +59,11 @@ struct r1_private_data_s { mempool_t *r1bio_pool; mempool_t *r1buf_pool; + + /* When taking over an array from a different personality, we store + * the new thread here until we fully activate the array. + */ + struct mdk_thread_s *thread; }; typedef struct r1_private_data_s conf_t; -- 2.7.4