diff options
Diffstat (limited to 'drivers/md/raid5.c')
| -rw-r--r-- | drivers/md/raid5.c | 719 |
1 files changed, 652 insertions, 67 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 2dba305daf3..dae740adaf6 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -22,6 +22,7 @@ #include <linux/raid/raid5.h> #include <linux/highmem.h> #include <linux/bitops.h> +#include <linux/kthread.h> #include <asm/atomic.h> #include <linux/raid/bitmap.h> @@ -93,11 +94,11 @@ static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) md_wakeup_thread(conf->mddev->thread); } - list_add_tail(&sh->lru, &conf->inactive_list); atomic_dec(&conf->active_stripes); - if (!conf->inactive_blocked || - atomic_read(&conf->active_stripes) < (conf->max_nr_stripes*3/4)) + if (!test_bit(STRIPE_EXPANDING, &sh->state)) { + list_add_tail(&sh->lru, &conf->inactive_list); wake_up(&conf->wait_for_stripe); + } } } } @@ -178,10 +179,10 @@ static int grow_buffers(struct stripe_head *sh, int num) static void raid5_build_block (struct stripe_head *sh, int i); -static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx) +static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks) { raid5_conf_t *conf = sh->raid_conf; - int disks = conf->raid_disks, i; + int i; if (atomic_read(&sh->count) != 0) BUG(); @@ -198,7 +199,9 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx) sh->pd_idx = pd_idx; sh->state = 0; - for (i=disks; i--; ) { + sh->disks = disks; + + for (i = sh->disks; i--; ) { struct r5dev *dev = &sh->dev[i]; if (dev->toread || dev->towrite || dev->written || @@ -215,7 +218,7 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx) insert_hash(conf, sh); } -static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector) +static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks) { struct stripe_head *sh; struct hlist_node *hn; @@ -223,7 +226,7 @@ static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector) CHECK_DEVLOCK(); PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) - if (sh->sector == sector) + if (sh->sector == sector && sh->disks == disks) return sh; PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); return NULL; @@ -232,8 +235,8 @@ static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector) static void unplug_slaves(mddev_t *mddev); static void raid5_unplug_device(request_queue_t *q); -static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, - int pd_idx, int noblock) +static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks, + int pd_idx, int noblock) { struct stripe_head *sh; @@ -245,7 +248,7 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector wait_event_lock_irq(conf->wait_for_stripe, conf->quiesce == 0, conf->device_lock, /* nothing */); - sh = __find_stripe(conf, sector); + sh = __find_stripe(conf, sector, disks); if (!sh) { if (!conf->inactive_blocked) sh = get_free_stripe(conf); @@ -259,11 +262,11 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector < (conf->max_nr_stripes *3/4) || !conf->inactive_blocked), conf->device_lock, - unplug_slaves(conf->mddev); + unplug_slaves(conf->mddev) ); conf->inactive_blocked = 0; } else - init_stripe(sh, sector, pd_idx); + init_stripe(sh, sector, pd_idx, disks); } else { if (atomic_read(&sh->count)) { if (!list_empty(&sh->lru)) @@ -271,9 +274,8 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector } else { if (!test_bit(STRIPE_HANDLE, &sh->state)) atomic_inc(&conf->active_stripes); - if (list_empty(&sh->lru)) - BUG(); - list_del_init(&sh->lru); + if (!list_empty(&sh->lru)) + list_del_init(&sh->lru); } } } while (sh == NULL); @@ -300,6 +302,7 @@ static int grow_one_stripe(raid5_conf_t *conf) kmem_cache_free(conf->slab_cache, sh); return 0; } + sh->disks = conf->raid_disks; /* we just created an active stripe so... */ atomic_set(&sh->count, 1); atomic_inc(&conf->active_stripes); @@ -313,14 +316,16 @@ 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; @@ -328,6 +333,129 @@ static int grow_stripes(raid5_conf_t *conf, int num) return 0; } +#ifdef CONFIG_MD_RAID5_RESHAPE +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; +} +#endif + static int drop_one_stripe(raid5_conf_t *conf) { struct stripe_head *sh; @@ -339,7 +467,7 @@ 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; @@ -360,7 +488,7 @@ static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done, { struct stripe_head *sh = bi->bi_private; raid5_conf_t *conf = sh->raid_conf; - int disks = conf->raid_disks, i; + int disks = sh->disks, i; int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); if (bi->bi_size) @@ -458,7 +586,7 @@ static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done, { struct stripe_head *sh = bi->bi_private; raid5_conf_t *conf = sh->raid_conf; - int disks = conf->raid_disks, i; + int disks = sh->disks, i; unsigned long flags; int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); @@ -612,7 +740,7 @@ static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks, static sector_t compute_blocknr(struct stripe_head *sh, int i) { raid5_conf_t *conf = sh->raid_conf; - int raid_disks = conf->raid_disks, data_disks = raid_disks - 1; + int raid_disks = sh->disks, data_disks = raid_disks - 1; sector_t new_sector = sh->sector, check; int sectors_per_chunk = conf->chunk_size >> 9; sector_t stripe; @@ -713,8 +841,7 @@ static void copy_data(int frombio, struct bio *bio, static void compute_block(struct stripe_head *sh, int dd_idx) { - raid5_conf_t *conf = sh->raid_conf; - int i, count, disks = conf->raid_disks; + int i, count, disks = sh->disks; void *ptr[MAX_XOR_BLOCKS], *p; PRINTK("compute_block, stripe %llu, idx %d\n", @@ -744,7 +871,7 @@ static void compute_block(struct stripe_head *sh, int dd_idx) static void compute_parity(struct stripe_head *sh, int method) { raid5_conf_t *conf = sh->raid_conf; - int i, pd_idx = sh->pd_idx, disks = conf->raid_disks, count; + int i, pd_idx = sh->pd_idx, disks = sh->disks, count; void *ptr[MAX_XOR_BLOCKS]; struct bio *chosen; @@ -910,6 +1037,20 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in return 0; } +static void end_reshape(raid5_conf_t *conf); + +static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks) +{ + int sectors_per_chunk = conf->chunk_size >> 9; + sector_t x = stripe; + int pd_idx, dd_idx; + int chunk_offset = sector_div(x, sectors_per_chunk); + stripe = x; + raid5_compute_sector(stripe*(disks-1)*sectors_per_chunk + + chunk_offset, disks, disks-1, &dd_idx, &pd_idx, conf); + return pd_idx; +} + /* * handle_stripe - do things to a stripe. @@ -932,11 +1073,11 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in static void handle_stripe(struct stripe_head *sh) { raid5_conf_t *conf = sh->raid_conf; - int disks = conf->raid_disks; + int disks = sh->disks; struct bio *return_bi= NULL; struct bio *bi; int i; - int syncing; + int syncing, expanding, expanded; int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; int non_overwrite = 0; int failed_num=0; @@ -951,6 +1092,8 @@ static void handle_stripe(struct stripe_head *sh) clear_bit(STRIPE_DELAYED, &sh->state); syncing = test_bit(STRIPE_SYNCING, &sh->state); + expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); + expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); /* Now to look around and see what can be done */ rcu_read_lock(); @@ -1143,13 +1286,14 @@ static void handle_stripe(struct stripe_head *sh) * parity, or to satisfy requests * or to load a block that is being partially written. */ - if (to_read || non_overwrite || (syncing && (uptodate < disks))) { + if (to_read || non_overwrite || (syncing && (uptodate < disks)) || expanding) { for (i=disks; i--;) { dev = &sh->dev[i]; if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && (dev->toread || (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || syncing || + expanding || (failed && (sh->dev[failed_num].toread || (sh->dev[failed_num].towrite && !test_bit(R5_OVERWRITE, &sh->dev[failed_num].flags)))) ) @@ -1339,13 +1483,77 @@ static void handle_stripe(struct stripe_head *sh) set_bit(R5_Wantwrite, &dev->flags); set_bit(R5_ReWrite, &dev->flags); set_bit(R5_LOCKED, &dev->flags); + locked++; } else { /* let's read it back */ set_bit(R5_Wantread, &dev->flags); set_bit(R5_LOCKED, &dev->flags); + locked++; } } + if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) { + /* Need to write out all blocks after computing parity */ + sh->disks = conf->raid_disks; + sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks); + compute_parity(sh, RECONSTRUCT_WRITE); + for (i= conf->raid_disks; i--;) { + set_bit(R5_LOCKED, &sh->dev[i].flags); + locked++; + set_bit(R5_Wantwrite, &sh->dev[i].flags); + } + clear_bit(STRIPE_EXPANDING, &sh->state); + } else if (expanded) { + clear_bit(STRIPE_EXPAND_READY, &sh->state); + atomic_dec(&conf->reshape_stripes); + wake_up(&conf->wait_for_overlap); + md_done_sync(conf->mddev, STRIPE_SECTORS, 1); + } + + if (expanding && locked == 0) { + /* We have read all the blocks in this stripe and now we need to + * copy some of them into a target stripe for expand. + */ + clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); + for (i=0; i< sh->disks; i++) + if (i != sh->pd_idx) { + int dd_idx, pd_idx, j; + struct stripe_head *sh2; + + sector_t bn = compute_blocknr(sh, i); + sector_t s = raid5_compute_sector(bn, conf->raid_disks, + conf->raid_disks-1, + &dd_idx, &pd_idx, conf); + sh2 = get_active_stripe(conf, s, conf->raid_disks, pd_idx, 1); + if (sh2 == NULL) + /* so far only the early blocks of this stripe + * have been requested. When later blocks + * get requested, we will try again + */ + continue; + if(!test_bit(STRIPE_EXPANDING, &sh2->state) || + test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { + /* must have already done this block */ + release_stripe(sh2); + continue; + } + memcpy(page_address(sh2->dev[dd_idx].page), + page_address(sh->dev[i].page), + STRIPE_SIZE); + set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); + set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); + for (j=0; j<conf->raid_disks; j++) + if (j != sh2->pd_idx && + !test_bit(R5_Expanded, &sh2->dev[j].flags)) + break; + if (j == conf->raid_disks) { + set_bit(STRIPE_EXPAND_READY, &sh2->state); + set_bit(STRIPE_HANDLE, &sh2->state); + } + release_stripe(sh2); + } + } + spin_unlock(&sh->lock); while ((bi=return_bi)) { @@ -1384,7 +1592,7 @@ static void handle_stripe(struct stripe_head *sh) rcu_read_unlock(); if (rdev) { - if (syncing) + if (syncing || expanding || expanded) md_sync_acct(rdev->bdev, STRIPE_SECTORS); bi->bi_bdev = rdev->bdev; @@ -1526,17 +1734,16 @@ static inline void raid5_plug_device(raid5_conf_t *conf) spin_unlock_irq(&conf->device_lock); } -static int make_request (request_queue_t *q, struct bio * bi) +static int make_request(request_queue_t *q, struct bio * bi) { mddev_t *mddev = q->queuedata; raid5_conf_t *conf = mddev_to_conf(mddev); - const unsigned int raid_disks = conf->raid_disks; - const unsigned int data_disks = raid_disks - 1; unsigned int dd_idx, pd_idx; sector_t new_sector; sector_t logical_sector, last_sector; struct stripe_head *sh; const int rw = bio_data_dir(bi); + int remaining; if (unlikely(bio_barrier(bi))) { bio_endio(bi, bi->bi_size, -EOPNOTSUPP); @@ -1555,20 +1762,77 @@ static int make_request (request_queue_t *q, struct bio * bi) for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { DEFINE_WAIT(w); - - new_sector = raid5_compute_sector(logical_sector, - raid_disks, data_disks, &dd_idx, &pd_idx, conf); + int disks; + retry: + prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); + if (likely(conf->expand_progress == MaxSector)) + disks = conf->raid_disks; + else { + /* spinlock is needed as expand_progress may be + * 64bit on a 32bit platform, and so it might be + * possible to see a half-updated value + * Ofcourse expand_progress could change after + * the lock is dropped, so once we get a reference + * to the stripe that we think it is, we will have + * to check again. + */ + spin_lock_irq(&conf->device_lock); + disks = conf->raid_disks; + if (logical_sector >= conf->expand_progress) + disks = conf->previous_raid_disks; + else { + if (logical_sector >= conf->expand_lo) { + spin_unlock_irq(&conf->device_lock); + schedule(); + goto retry; + } + } + spin_unlock_irq(&conf->device_lock); + } + new_sector = raid5_compute_sector(logical_sector, disks, disks - 1, + &dd_idx, &pd_idx, conf); PRINTK("raid5: make_request, sector %llu logical %llu\n", (unsigned long long)new_sector, (unsigned long long)logical_sector); - retry: - prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); - sh = get_active_stripe(conf, new_sector, pd_idx, (bi->bi_rw&RWA_MASK)); + sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK)); if (sh) { - if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { - /* Add failed due to overlap. Flush everything + if (unlikely(conf->expand_progress != MaxSector)) { + /* expansion might have moved on while waiting for a + * stripe, so we must do the range check again. + * Expansion could still move past after this + * test, but as we are holding a reference to + * 'sh', we know that if that happens, + * STRIPE_EXPANDING will get set and the expansion + * won't proceed until we finish with the stripe. + */ + int must_retry = 0; + spin_lock_irq(&conf->device_lock); + if (logical_sector < conf->expand_progress && + disks == conf->previous_raid_disks) + /* mismatch, need to try again */ + must_retry = 1; + spin_unlock_irq(&conf->device_lock); + if (must_retry) { + release_stripe(sh); + goto retry; + } + } + /* FIXME what if we get a false positive because these + * are being updated. + */ + if (logical_sector >= mddev->suspend_lo && + logical_sector < mddev->suspend_hi) { + release_stripe(sh); + schedule(); + goto retry; + } + + if (test_bit(STRIPE_EXPANDING, &sh->state) || + !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { + /* Stripe is busy expanding or + * add failed due to overlap. Flush everything * and wait a while */ raid5_unplug_device(mddev->queue); @@ -1580,7 +1844,6 @@ static int make_request (request_queue_t *q, struct bio * bi) raid5_plug_device(conf); handle_stripe(sh); release_stripe(sh); - } else { /* cannot get stripe for read-ahead, just give-up */ clear_bit(BIO_UPTODATE, &bi->bi_flags); @@ -1590,7 +1853,9 @@ static int make_request (request_queue_t *q, struct bio * bi) } spin_lock_irq(&conf->device_lock); - if (--bi->bi_phys_segments == 0) { + remaining = --bi->bi_phys_segments; + spin_unlock_irq(&conf->device_lock); + if (remaining == 0) { int bytes = bi->bi_size; if ( bio_data_dir(bi) == WRITE ) @@ -1598,7 +1863,6 @@ static int make_request (request_queue_t *q, struct bio * bi) bi->bi_size = 0; bi->bi_end_io(bi, bytes, 0); } - spin_unlock_irq(&conf->device_lock); return 0; } @@ -1607,12 +1871,8 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i { raid5_conf_t *conf = (raid5_conf_t *) mddev->private; struct stripe_head *sh; - int sectors_per_chunk = conf->chunk_size >> 9; - sector_t x; - unsigned long stripe; - int chunk_offset; - int dd_idx, pd_idx; - sector_t first_sector; + int pd_idx; + sector_t first_sector, last_sector; int raid_disks = conf->raid_disks; int data_disks = raid_disks-1; sector_t max_sector = mddev->size << 1; @@ -1621,6 +1881,10 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i if (sector_nr >= max_sector) { /* just being told to finish up .. nothing much to do */ unplug_slaves(mddev); + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { + end_reshape(conf); + return 0; + } if (mddev->curr_resync < max_sector) /* aborted */ bitmap_end_sync(mddev->bitmap, mddev->curr_resync, @@ -1631,6 +1895,123 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i return 0; } + + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { + /* reshaping is quite different to recovery/resync so it is + * handled quite separately ... here. + * + * On each call to sync_request, we gather one chunk worth of + * destination stripes and flag them as expanding. + * Then we find all the source stripes and request reads. + * As the reads complete, handle_stripe will copy the data + * into the destination stripe and release that stripe. + */ + int i; + int dd_idx; + sector_t writepos, safepos, gap; + + if (sector_nr == 0 && + conf->expand_progress != 0) { + /* restarting in the middle, skip the initial sectors */ + sector_nr = conf->expand_progress; + sector_div(sector_nr, conf->raid_disks-1); + *skipped = 1; + return sector_nr; + } + + /* we update the metadata when there is more than 3Meg + * in the block range (that is rather arbitrary, should + * probably be time based) or when the data about to be + * copied would over-write the source of the data at + * the front of the range. + * i.e. one new_stripe forward from expand_progress new_maps + * to after where expand_lo old_maps to + */ + writepos = conf->expand_progress + + conf->chunk_size/512*(conf->raid_disks-1); + sector_div(writepos, conf->raid_disks-1); + safepos = conf->expand_lo; + sector_div(safepos, conf->previous_raid_disks-1); + gap = conf->expand_progress - conf->expand_lo; + + if (writepos >= safepos || + gap > (conf->raid_disks-1)*3000*2 /*3Meg*/) { + /* Cannot proceed until we've updated the superblock... */ + wait_event(conf->wait_for_overlap, + atomic_read(&conf->reshape_stripes)==0); + mddev->reshape_position = conf->expand_progress; + mddev->sb_dirty = 1; + md_wakeup_thread(mddev->thread); + wait_event(mddev->sb_wait, mddev->sb_dirty == 0 || + kthread_should_stop()); + spin_lock_irq(&conf->device_lock); + conf->expand_lo = mddev->reshape_position; + spin_unlock_irq(&conf->device_lock); + wake_up(&conf->wait_for_overlap); + } + + for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) { + int j; + int skipped = 0; + pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks); + sh = get_active_stripe(conf, sector_nr+i, + conf->raid_disks, pd_idx, 0); + set_bit(STRIPE_EXPANDING, &sh->state); + atomic_inc(&conf->reshape_stripes); + /* If any of this stripe is beyond the end of the old + * array, then we need to zero those blocks + */ + for (j=sh->disks; j--;) { + sector_t s; + if (j == sh->pd_idx) + continue; + s = compute_blocknr(sh, j); + if (s < (mddev->array_size<<1)) { + skipped = 1; + continue; + } + memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); + set_bit(R5_Expanded, &sh->dev[j].flags); + set_bit(R5_UPTODATE, &sh->dev[j].flags); + } + if (!skipped) { + set_bit(STRIPE_EXPAND_READY, &sh->state); + set_bit(STRIPE_HANDLE, &sh->state); + } + release_stripe(sh); + } + spin_lock_irq(&conf->device_lock); + conf->expand_progress = (sector_nr + i)*(conf->raid_disks-1); + spin_unlock_irq(&conf->device_lock); + /* Ok, those stripe are ready. We can start scheduling + * reads on the source stripes. + * The source stripes are determined by mapping the first and last + * block on the destination stripes. + */ + raid_disks = conf->previous_raid_disks; + data_disks = raid_disks - 1; + first_sector = + raid5_compute_sector(sector_nr*(conf->raid_disks-1), + raid_disks, data_disks, + &dd_idx, &pd_idx, conf); + last_sector = + raid5_compute_sector((sector_nr+conf->chunk_size/512) + *(conf->raid_disks-1) -1, + raid_disks, data_disks, + &dd_idx, &pd_idx, conf); + if (last_sector >= (mddev->size<<1)) + last_sector = (mddev->size<<1)-1; + while (first_sector <= last_sector) { + pd_idx = stripe_to_pdidx(first_sector, conf, conf->previous_raid_disks); + sh = get_active_stripe(conf, first_sector, + conf->previous_raid_disks, pd_idx, 0); + set_bit(STRIPE_EXPAND_SOURCE, &sh->state); + set_bit(STRIPE_HANDLE, &sh->state); + release_stripe(sh); + first_sector += STRIPE_SECTORS; + } + return conf->chunk_size>>9; + } /* if there is 1 or more failed drives and we are trying * to resync, then assert that we are finished, because there is * nothing we can do. @@ -1649,16 +2030,10 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ } - x = sector_nr; - chunk_offset = sector_div(x, sectors_per_chunk); - stripe = x; - BUG_ON(x != stripe); - - first_sector = raid5_compute_sector((sector_t)stripe*data_disks*sectors_per_chunk - + chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf); - sh = get_active_stripe(conf, sector_nr, pd_idx, 1); + pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks); + sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1); if (sh == NULL) { - sh = get_active_stripe(conf, sector_nr, pd_idx, 0); + sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0); /* make sure we don't swamp the stripe cache if someone else * is trying to get access */ @@ -1822,11 +2197,64 @@ static int run(mddev_t *mddev) return -EIO; } - mddev->private = kzalloc(sizeof (raid5_conf_t) - + mddev->raid_disks * sizeof(struct disk_info), - GFP_KERNEL); + if (mddev->reshape_position != MaxSector) { + /* Check that we can continue the reshape. + * Currently only disks can change, it must + * increase, and we must be past the point where + * a stripe over-writes itself + */ + sector_t here_new, here_old; + int old_disks; + + if (mddev->new_level != mddev->level || + mddev->new_layout != mddev->layout || + mddev->new_chunk != mddev->chunk_size) { + printk(KERN_ERR "raid5: %s: unsupported reshape required - aborting.\n", + mdname(mddev)); + return -EINVAL; + } + if (mddev->delta_disks <= 0) { + printk(KERN_ERR "raid5: %s: unsupported reshape (reduce disks) required - aborting.\n", + mdname(mddev)); + return -EINVAL; + } + old_disks = mddev->raid_disks - mddev->delta_disks; + /* reshape_position must be on a new-stripe boundary, and one + * further up in new geometry must map after here in old geometry. + */ + here_new = mddev->reshape_position; + if (sector_div(here_new, (mddev->chunk_size>>9)*(mddev->raid_disks-1))) { + printk(KERN_ERR "raid5: reshape_position not on a stripe boundary\n"); + return -EINVAL; + } + /* here_new is the stripe we will write to */ + here_old = mddev->reshape_position; + sector_div(here_old, (mddev->chunk_size>>9)*(old_disks-1)); + /* here_old is the first stripe that we might need to read from */ + if (here_new >= here_old) { + /* Reading from the same stripe as writing to - bad */ + printk(KERN_ERR "raid5: reshape_position too early for auto-recovery - aborting.\n"); + return -EINVAL; + } + printk(KERN_INFO "raid5: reshape will continue\n"); + /* OK, we should be able to continue; */ + } + + + mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL); if ((conf = mddev->private) == NULL) goto abort; + if (mddev->reshape_position == MaxSector) { + conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks; + } else { + conf->raid_disks = mddev->raid_disks; + conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; + } + + conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info), + GFP_KERNEL); + if (!conf->disks) + goto abort; conf->mddev = mddev; @@ -1847,7 +2275,7 @@ static int run(mddev_t *mddev) ITERATE_RDEV(mddev,rdev,tmp) { raid_disk = rdev->raid_disk; - if (raid_disk >= mddev->raid_disks + if (raid_disk >= conf->raid_disks || raid_disk < 0) continue; disk = conf->disks + raid_disk; @@ -1863,7 +2291,6 @@ static int run(mddev_t *mddev) } } - conf->raid_disks = mddev->raid_disks; /* * 0 for a fully functional array, 1 for a degraded array. */ @@ -1873,6 +2300,7 @@ static int run(mddev_t *mddev) conf->level = mddev->level; conf->algorithm = mddev->layout; conf->max_nr_stripes = NR_STRIPES; + conf->expand_progress = mddev->reshape_position; /* device size must be a multiple of chunk size */ mddev->size &= ~(mddev->chunk_size/1024 -1); @@ -1945,6 +2373,21 @@ static int run(mddev_t *mddev) print_raid5_conf(conf); + if (conf->expand_progress != MaxSector) { + printk("...ok start reshape thread\n"); + conf->expand_lo = conf->expand_progress; + atomic_set(&conf->reshape_stripes, 0); + clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); + clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); + set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); + set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); + mddev->sync_thread = md_register_thread(md_do_sync, mddev, + "%s_reshape"); + /* FIXME if md_register_thread fails?? */ + md_wakeup_thread(mddev->sync_thread); + + } + /* read-ahead size must cover two whole stripes, which is * 2 * (n-1) * chunksize where 'n' is the number of raid devices */ @@ -1960,12 +2403,13 @@ static int run(mddev_t *mddev) mddev->queue->unplug_fn = raid5_unplug_device; mddev->queue->issue_flush_fn = raid5_issue_flush; + mddev->array_size = mddev->size * (conf->previous_raid_disks - 1); - mddev->array_size = mddev->size * (mddev->raid_disks - 1); return 0; abort: if (conf) { print_raid5_conf(conf); + kfree(conf->disks); kfree(conf->stripe_hashtbl); kfree(conf); } @@ -1986,6 +2430,7 @@ static int stop(mddev_t *mddev) kfree(conf->stripe_hashtbl); blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); + kfree(conf->disks); kfree(conf); mddev->private = NULL; return 0; @@ -2001,7 +2446,7 @@ static void print_sh (struct stripe_head *sh) printk("sh %llu, count %d.\n", (unsigned long long)sh->sector, atomic_read(&sh->count)); printk("sh %llu, ", (unsigned long long)sh->sector); - for (i = 0; i < sh->raid_conf->raid_disks; i++) { + for (i = 0; i < sh->disks; i++) { printk("(cache%d: %p %ld) ", i, sh->dev[i].page, sh->dev[i].flags); } @@ -2132,7 +2577,7 @@ static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) /* * find the disk ... */ - for (disk=0; disk < mddev->raid_disks; disk++) + for (disk=0; disk < conf->raid_disks; disk++) if ((p=conf->disks + disk)->rdev == NULL) { clear_bit(In_sync, &rdev->flags); rdev->raid_disk = disk; @@ -2168,11 +2613,146 @@ static int raid5_resize(mddev_t *mddev, sector_t sectors) return 0; } +#ifdef CONFIG_MD_RAID5_RESHAPE +static int raid5_check_reshape(mddev_t *mddev) +{ + raid5_conf_t *conf = mddev_to_conf(mddev); + int err; + + if (mddev->delta_disks < 0 || + mddev->new_level != mddev->level) + return -EINVAL; /* Cannot shrink array or change level yet */ + if (mddev->delta_disks == 0) + return 0; /* nothing to do */ + + /* Can only proceed if there are plenty of stripe_heads. + * We need a minimum of one full stripe,, and for sensible progress + * it is best to have about 4 times that. + * If we require 4 times, then the default 256 4K stripe_heads will + * allow for chunk sizes up to 256K, which is probably OK. + * If the chunk size is greater, user-space should request more + * stripe_heads first. + */ + if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes || + (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) { + printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n", + (mddev->chunk_size / STRIPE_SIZE)*4); + return -ENOSPC; + } + + err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks); + if (err) + return err; + + /* looks like we might be able to manage this */ + return 0; +} + +static int raid5_start_reshape(mddev_t *mddev) +{ + raid5_conf_t *conf = mddev_to_conf(mddev); + mdk_rdev_t *rdev; + struct list_head *rtmp; + int spares = 0; + int added_devices = 0; + + if (mddev->degraded || + test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) + return -EBUSY; + + ITERATE_RDEV(mddev, rdev, rtmp) + if (rdev->raid_disk < 0 && + !test_bit(Faulty, &rdev->flags)) + spares++; + + if (spares < mddev->delta_disks-1) + /* Not enough devices even to make a degraded array + * of that size + */ + return -EINVAL; + + atomic_set(&conf->reshape_stripes, 0); + spin_lock_irq(&conf->device_lock); + conf->previous_raid_disks = conf->raid_disks; + conf->raid_disks += mddev->delta_disks; + conf->expand_progress = 0; + conf->expand_lo = 0; + spin_unlock_irq(&conf->device_lock); + + /* Add some new drives, as many as will fit. + * We know there are enough to make the newly sized array work. + */ + ITERATE_RDEV(mddev, rdev, rtmp) + if (rdev->raid_disk < 0 && + !test_bit(Faulty, &rdev->flags)) { + if (raid5_add_disk(mddev, rdev)) { + char nm[20]; + set_bit(In_sync, &rdev->flags); + conf->working_disks++; + added_devices++; + sprintf(nm, "rd%d", rdev->raid_disk); + sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); + } else + break; + } + + mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices; + mddev->raid_disks = conf->raid_disks; + mddev->reshape_position = 0; + mddev->sb_dirty = 1; + + clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); + clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); + set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); + set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); + mddev->sync_thread = md_register_thread(md_do_sync, mddev, + "%s_reshape"); + if (!mddev->sync_thread) { + mddev->recovery = 0; + spin_lock_irq(&conf->device_lock); + mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; + conf->expand_progress = MaxSector; + spin_unlock_irq(&conf->device_lock); + return -EAGAIN; + } + md_wakeup_thread(mddev->sync_thread); + md_new_event(mddev); + return 0; +} +#endif + +static void end_reshape(raid5_conf_t *conf) +{ + struct block_device *bdev; + + if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { + conf->mddev->array_size = conf->mddev->size * (conf->raid_disks-1); + set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1); + conf->mddev->changed = 1; + + bdev = bdget_disk(conf->mddev->gendisk, 0); + if (bdev) { + mutex_lock(&bdev->bd_inode->i_mutex); + i_size_write(bdev->bd_inode, conf->mddev->array_size << 10); + mutex_unlock(&bdev->bd_inode->i_mutex); + bdput(bdev); + } + spin_lock_irq(&conf->device_lock); + conf->expand_progress = MaxSector; + spin_unlock_irq(&conf->device_lock); + conf->mddev->reshape_position = MaxSector; + } +} + static void raid5_quiesce(mddev_t *mddev, int state) { raid5_conf_t *conf = mddev_to_conf(mddev); switch(state) { + case 2: /* resume for a suspend */ + wake_up(&conf->wait_for_overlap); + break; + case 1: /* stop all writes */ spin_lock_irq(&conf->device_lock); conf->quiesce = 1; @@ -2186,6 +2766,7 @@ static void raid5_quiesce(mddev_t *mddev, int state) spin_lock_irq(&conf->device_lock); conf->quiesce = 0; wake_up(&conf->wait_for_stripe); + wake_up(&conf->wait_for_overlap); spin_unlock_irq(&conf->device_lock); break; } @@ -2206,6 +2787,10 @@ static struct mdk_personality raid5_personality = .spare_active = raid5_spare_active, .sync_request = sync_request, .resize = raid5_resize, +#ifdef CONFIG_MD_RAID5_RESHAPE + .check_reshape = raid5_check_reshape, + .start_reshape = raid5_start_reshape, +#endif .quiesce = raid5_quiesce, }; |