diff options
| -rw-r--r-- | drivers/md/md.c | 2 | ||||
| -rw-r--r-- | drivers/md/raid5.c | 131 | ||||
| -rw-r--r-- | drivers/md/raid6main.c | 4 | ||||
| -rw-r--r-- | include/linux/raid/raid5.h | 9 |
4 files changed, 137 insertions, 9 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index a3ecaf8ed30a..c7b7656f9aa5 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2775,7 +2775,6 @@ static void autorun_array(mddev_t *mddev) */ static void autorun_devices(int part) { - struct list_head candidates; struct list_head *tmp; mdk_rdev_t *rdev0, *rdev; mddev_t *mddev; @@ -2784,6 +2783,7 @@ static void autorun_devices(int part) printk(KERN_INFO "md: autorun ...\n"); while (!list_empty(&pending_raid_disks)) { dev_t dev; + LIST_HEAD(candidates); rdev0 = list_entry(pending_raid_disks.next, mdk_rdev_t, same_set); diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 03f31379cebb..6c20b44509d8 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -313,20 +313,143 @@ static int grow_stripes(raid5_conf_t *conf, int num) kmem_cache_t *sc; int devs = conf->raid_disks; - sprintf(conf->cache_name, "raid5/%s", mdname(conf->mddev)); - - sc = kmem_cache_create(conf->cache_name, + sprintf(conf->cache_name[0], "raid5/%s", mdname(conf->mddev)); + sprintf(conf->cache_name[1], "raid5/%s-alt", mdname(conf->mddev)); + conf->active_name = 0; + sc = kmem_cache_create(conf->cache_name[conf->active_name], sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), 0, 0, NULL, NULL); if (!sc) return 1; conf->slab_cache = sc; + conf->pool_size = devs; while (num--) { if (!grow_one_stripe(conf)) return 1; } return 0; } +static int resize_stripes(raid5_conf_t *conf, int newsize) +{ + /* Make all the stripes able to hold 'newsize' devices. + * New slots in each stripe get 'page' set to a new page. + * + * This happens in stages: + * 1/ create a new kmem_cache and allocate the required number of + * stripe_heads. + * 2/ gather all the old stripe_heads and tranfer the pages across + * to the new stripe_heads. This will have the side effect of + * freezing the array as once all stripe_heads have been collected, + * no IO will be possible. Old stripe heads are freed once their + * pages have been transferred over, and the old kmem_cache is + * freed when all stripes are done. + * 3/ reallocate conf->disks to be suitable bigger. If this fails, + * we simple return a failre status - no need to clean anything up. + * 4/ allocate new pages for the new slots in the new stripe_heads. + * If this fails, we don't bother trying the shrink the + * stripe_heads down again, we just leave them as they are. + * As each stripe_head is processed the new one is released into + * active service. + * + * Once step2 is started, we cannot afford to wait for a write, + * so we use GFP_NOIO allocations. + */ + struct stripe_head *osh, *nsh; + LIST_HEAD(newstripes); + struct disk_info *ndisks; + int err = 0; + kmem_cache_t *sc; + int i; + + if (newsize <= conf->pool_size) + return 0; /* never bother to shrink */ + + /* Step 1 */ + sc = kmem_cache_create(conf->cache_name[1-conf->active_name], + sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), + 0, 0, NULL, NULL); + if (!sc) + return -ENOMEM; + + for (i = conf->max_nr_stripes; i; i--) { + nsh = kmem_cache_alloc(sc, GFP_KERNEL); + if (!nsh) + break; + + memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev)); + + nsh->raid_conf = conf; + spin_lock_init(&nsh->lock); + + list_add(&nsh->lru, &newstripes); + } + if (i) { + /* didn't get enough, give up */ + while (!list_empty(&newstripes)) { + nsh = list_entry(newstripes.next, struct stripe_head, lru); + list_del(&nsh->lru); + kmem_cache_free(sc, nsh); + } + kmem_cache_destroy(sc); + return -ENOMEM; + } + /* Step 2 - Must use GFP_NOIO now. + * OK, we have enough stripes, start collecting inactive + * stripes and copying them over + */ + list_for_each_entry(nsh, &newstripes, lru) { + spin_lock_irq(&conf->device_lock); + wait_event_lock_irq(conf->wait_for_stripe, + !list_empty(&conf->inactive_list), + conf->device_lock, + unplug_slaves(conf->mddev); + ); + osh = get_free_stripe(conf); + spin_unlock_irq(&conf->device_lock); + atomic_set(&nsh->count, 1); + for(i=0; i<conf->pool_size; i++) + nsh->dev[i].page = osh->dev[i].page; + for( ; i<newsize; i++) + nsh->dev[i].page = NULL; + kmem_cache_free(conf->slab_cache, osh); + } + kmem_cache_destroy(conf->slab_cache); + + /* Step 3. + * At this point, we are holding all the stripes so the array + * is completely stalled, so now is a good time to resize + * conf->disks. + */ + ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); + if (ndisks) { + for (i=0; i<conf->raid_disks; i++) + ndisks[i] = conf->disks[i]; + kfree(conf->disks); + conf->disks = ndisks; + } else + err = -ENOMEM; + + /* Step 4, return new stripes to service */ + while(!list_empty(&newstripes)) { + nsh = list_entry(newstripes.next, struct stripe_head, lru); + list_del_init(&nsh->lru); + for (i=conf->raid_disks; i < newsize; i++) + if (nsh->dev[i].page == NULL) { + struct page *p = alloc_page(GFP_NOIO); + nsh->dev[i].page = p; + if (!p) + err = -ENOMEM; + } + release_stripe(nsh); + } + /* critical section pass, GFP_NOIO no longer needed */ + + conf->slab_cache = sc; + conf->active_name = 1-conf->active_name; + conf->pool_size = newsize; + return err; +} + static int drop_one_stripe(raid5_conf_t *conf) { @@ -339,7 +462,7 @@ static int drop_one_stripe(raid5_conf_t *conf) return 0; if (atomic_read(&sh->count)) BUG(); - shrink_buffers(sh, conf->raid_disks); + shrink_buffers(sh, conf->pool_size); kmem_cache_free(conf->slab_cache, sh); atomic_dec(&conf->active_stripes); return 1; diff --git a/drivers/md/raid6main.c b/drivers/md/raid6main.c index c7632f6cc487..6df4930fddec 100644 --- a/drivers/md/raid6main.c +++ b/drivers/md/raid6main.c @@ -331,9 +331,9 @@ static int grow_stripes(raid6_conf_t *conf, int num) kmem_cache_t *sc; int devs = conf->raid_disks; - sprintf(conf->cache_name, "raid6/%s", mdname(conf->mddev)); + sprintf(conf->cache_name[0], "raid6/%s", mdname(conf->mddev)); - sc = kmem_cache_create(conf->cache_name, + sc = kmem_cache_create(conf->cache_name[0], sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), 0, 0, NULL, NULL); if (!sc) diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h index 94dbdd406f12..b7b2653af7bb 100644 --- a/include/linux/raid/raid5.h +++ b/include/linux/raid/raid5.h @@ -216,7 +216,11 @@ struct raid5_private_data { struct list_head bitmap_list; /* stripes delaying awaiting bitmap update */ atomic_t preread_active_stripes; /* stripes with scheduled io */ - char cache_name[20]; + /* unfortunately we need two cache names as we temporarily have + * two caches. + */ + int active_name; + char cache_name[2][20]; kmem_cache_t *slab_cache; /* for allocating stripes */ int seq_flush, seq_write; @@ -238,7 +242,8 @@ struct raid5_private_data { wait_queue_head_t wait_for_overlap; int inactive_blocked; /* release of inactive stripes blocked, * waiting for 25% to be free - */ + */ + int pool_size; /* number of disks in stripeheads in pool */ spinlock_t device_lock; struct disk_info *disks; }; |