X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fmd%2Fraid5.c;h=11c3d7bfa797e8777c5b2bdf47d9ec6f68c7da74;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=2dba305daf3c887799453caefae8d5a36535de4b;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 2dba305da..11c3d7bfa 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2,8 +2,11 @@ * raid5.c : Multiple Devices driver for Linux * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman * Copyright (C) 1999, 2000 Ingo Molnar + * Copyright (C) 2002, 2003 H. Peter Anvin * - * RAID-5 management functions. + * RAID-4/5/6 management functions. + * Thanks to Penguin Computing for making the RAID-6 development possible + * by donating a test server! * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -15,14 +18,38 @@ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +/* + * BITMAP UNPLUGGING: + * + * The sequencing for updating the bitmap reliably is a little + * subtle (and I got it wrong the first time) so it deserves some + * explanation. + * + * We group bitmap updates into batches. Each batch has a number. + * We may write out several batches at once, but that isn't very important. + * conf->bm_write is the number of the last batch successfully written. + * conf->bm_flush is the number of the last batch that was closed to + * new additions. + * When we discover that we will need to write to any block in a stripe + * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq + * the number of the batch it will be in. This is bm_flush+1. + * When we are ready to do a write, if that batch hasn't been written yet, + * we plug the array and queue the stripe for later. + * When an unplug happens, we increment bm_flush, thus closing the current + * batch. + * When we notice that bm_flush > bm_write, we write out all pending updates + * to the bitmap, and advance bm_write to where bm_flush was. + * This may occasionally write a bit out twice, but is sure never to + * miss any bits. + */ -#include #include #include -#include #include #include +#include #include +#include "raid6.h" #include @@ -67,22 +94,32 @@ #define __inline__ #endif +#if !RAID6_USE_EMPTY_ZERO_PAGE +/* In .bss so it's zeroed */ +const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); +#endif + +static inline int raid6_next_disk(int disk, int raid_disks) +{ + disk++; + return (disk < raid_disks) ? disk : 0; +} static void print_raid5_conf (raid5_conf_t *conf); static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) { if (atomic_dec_and_test(&sh->count)) { - if (!list_empty(&sh->lru)) - BUG(); - if (atomic_read(&conf->active_stripes)==0) - BUG(); + BUG_ON(!list_empty(&sh->lru)); + BUG_ON(atomic_read(&conf->active_stripes)==0); if (test_bit(STRIPE_HANDLE, &sh->state)) { - if (test_bit(STRIPE_DELAYED, &sh->state)) + if (test_bit(STRIPE_DELAYED, &sh->state)) { list_add_tail(&sh->lru, &conf->delayed_list); - else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && - conf->seq_write == sh->bm_seq) + blk_plug_device(conf->mddev->queue); + } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && + sh->bm_seq - conf->seq_write > 0) { list_add_tail(&sh->lru, &conf->bitmap_list); - else { + blk_plug_device(conf->mddev->queue); + } else { clear_bit(STRIPE_BIT_DELAY, &sh->state); list_add_tail(&sh->lru, &conf->handle_list); } @@ -93,11 +130,13 @@ 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); + if (conf->retry_read_aligned) + md_wakeup_thread(conf->mddev->thread); + } } } } @@ -105,7 +144,7 @@ static void release_stripe(struct stripe_head *sh) { raid5_conf_t *conf = sh->raid_conf; unsigned long flags; - + spin_lock_irqsave(&conf->device_lock, flags); __release_stripe(conf, sh); spin_unlock_irqrestore(&conf->device_lock, flags); @@ -118,7 +157,7 @@ static inline void remove_hash(struct stripe_head *sh) hlist_del_init(&sh->hash); } -static void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) +static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) { struct hlist_head *hp = stripe_hash(conf, sh->sector); @@ -178,27 +217,27 @@ 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(); - if (test_bit(STRIPE_HANDLE, &sh->state)) - BUG(); + BUG_ON(atomic_read(&sh->count) != 0); + BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); CHECK_DEVLOCK(); PRINTK("init_stripe called, stripe %llu\n", (unsigned long long)sh->sector); remove_hash(sh); - + sh->sector = sector; 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 +254,7 @@ 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 +262,7 @@ 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 +271,8 @@ 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 +284,7 @@ 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); @@ -259,19 +298,19 @@ 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); + raid5_unplug_device(conf->mddev->queue) ); 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)) - BUG(); + BUG_ON(!list_empty(&sh->lru)); } else { if (!test_bit(STRIPE_HANDLE, &sh->state)) atomic_inc(&conf->active_stripes); - if (list_empty(&sh->lru)) + if (list_empty(&sh->lru) && + !test_bit(STRIPE_EXPANDING, &sh->state)) BUG(); list_del_init(&sh->lru); } @@ -300,6 +339,7 @@ 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); @@ -310,24 +350,150 @@ static int grow_one_stripe(raid5_conf_t *conf) static int grow_stripes(raid5_conf_t *conf, int num) { - kmem_cache_t *sc; + struct kmem_cache *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; - while (num--) { + conf->pool_size = devs; + while (num--) if (!grow_one_stripe(conf)) return 1; - } 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; + struct kmem_cache *sc; + int i; + + if (newsize <= conf->pool_size) + return 0; /* never bother to shrink */ + + md_allow_write(conf->mddev); + + /* 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; ipool_size; i++) + nsh->dev[i].page = osh->dev[i].page; + for( ; idev[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; iraid_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; @@ -337,9 +503,8 @@ static int drop_one_stripe(raid5_conf_t *conf) spin_unlock_irq(&conf->device_lock); if (!sh) return 0; - if (atomic_read(&sh->count)) - BUG(); - shrink_buffers(sh, conf->raid_disks); + BUG_ON(atomic_read(&sh->count)); + shrink_buffers(sh, conf->pool_size); kmem_cache_free(conf->slab_cache, sh); atomic_dec(&conf->active_stripes); return 1; @@ -360,8 +525,10 @@ 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); + char b[BDEVNAME_SIZE]; + mdk_rdev_t *rdev; if (bi->bi_size) return 1; @@ -379,55 +546,41 @@ static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done, } if (uptodate) { -#if 0 - struct bio *bio; - unsigned long flags; - spin_lock_irqsave(&conf->device_lock, flags); - /* we can return a buffer if we bypassed the cache or - * if the top buffer is not in highmem. If there are - * multiple buffers, leave the extra work to - * handle_stripe - */ - buffer = sh->bh_read[i]; - if (buffer && - (!PageHighMem(buffer->b_page) - || buffer->b_page == bh->b_page ) - ) { - sh->bh_read[i] = buffer->b_reqnext; - buffer->b_reqnext = NULL; - } else - buffer = NULL; - spin_unlock_irqrestore(&conf->device_lock, flags); - if (sh->bh_page[i]==bh->b_page) - set_buffer_uptodate(bh); - if (buffer) { - if (buffer->b_page != bh->b_page) - memcpy(buffer->b_data, bh->b_data, bh->b_size); - buffer->b_end_io(buffer, 1); - } -#else set_bit(R5_UPTODATE, &sh->dev[i].flags); -#endif if (test_bit(R5_ReadError, &sh->dev[i].flags)) { - printk(KERN_INFO "raid5: read error corrected!!\n"); + rdev = conf->disks[i].rdev; + printk(KERN_INFO "raid5:%s: read error corrected (%lu sectors at %llu on %s)\n", + mdname(conf->mddev), STRIPE_SECTORS, + (unsigned long long)sh->sector + rdev->data_offset, + bdevname(rdev->bdev, b)); clear_bit(R5_ReadError, &sh->dev[i].flags); clear_bit(R5_ReWrite, &sh->dev[i].flags); } if (atomic_read(&conf->disks[i].rdev->read_errors)) atomic_set(&conf->disks[i].rdev->read_errors, 0); } else { + const char *bdn = bdevname(conf->disks[i].rdev->bdev, b); int retry = 0; + rdev = conf->disks[i].rdev; + clear_bit(R5_UPTODATE, &sh->dev[i].flags); - atomic_inc(&conf->disks[i].rdev->read_errors); + atomic_inc(&rdev->read_errors); if (conf->mddev->degraded) - printk(KERN_WARNING "raid5: read error not correctable.\n"); + printk(KERN_WARNING "raid5:%s: read error not correctable (sector %llu on %s).\n", + mdname(conf->mddev), + (unsigned long long)sh->sector + rdev->data_offset, + bdn); else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) /* Oh, no!!! */ - printk(KERN_WARNING "raid5: read error NOT corrected!!\n"); - else if (atomic_read(&conf->disks[i].rdev->read_errors) + printk(KERN_WARNING "raid5:%s: read error NOT corrected!! (sector %llu on %s).\n", + mdname(conf->mddev), + (unsigned long long)sh->sector + rdev->data_offset, + bdn); + else if (atomic_read(&rdev->read_errors) > conf->max_nr_stripes) printk(KERN_WARNING - "raid5: Too many read errors, failing device.\n"); + "raid5:%s: Too many read errors, failing device %s.\n", + mdname(conf->mddev), bdn); else retry = 1; if (retry) @@ -435,18 +588,10 @@ static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done, else { clear_bit(R5_ReadError, &sh->dev[i].flags); clear_bit(R5_ReWrite, &sh->dev[i].flags); - md_error(conf->mddev, conf->disks[i].rdev); + md_error(conf->mddev, rdev); } } rdev_dec_pending(conf->disks[i].rdev, conf->mddev); -#if 0 - /* must restore b_page before unlocking buffer... */ - if (sh->bh_page[i] != bh->b_page) { - bh->b_page = sh->bh_page[i]; - bh->b_data = page_address(bh->b_page); - clear_buffer_uptodate(bh); - } -#endif clear_bit(R5_LOCKED, &sh->dev[i].flags); set_bit(STRIPE_HANDLE, &sh->state); release_stripe(sh); @@ -458,8 +603,7 @@ 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; - unsigned long flags; + int disks = sh->disks, i; int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); if (bi->bi_size) @@ -477,7 +621,6 @@ static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done, return 0; } - spin_lock_irqsave(&conf->device_lock, flags); if (!uptodate) md_error(conf->mddev, conf->disks[i].rdev); @@ -485,8 +628,7 @@ static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done, clear_bit(R5_LOCKED, &sh->dev[i].flags); set_bit(STRIPE_HANDLE, &sh->state); - __release_stripe(conf, sh); - spin_unlock_irqrestore(&conf->device_lock, flags); + release_stripe(sh); return 0; } @@ -509,8 +651,7 @@ static void raid5_build_block (struct stripe_head *sh, int i) dev->req.bi_private = sh; dev->flags = 0; - if (i != sh->pd_idx) - dev->sector = compute_blocknr(sh, i); + dev->sector = compute_blocknr(sh, i); } static void error(mddev_t *mddev, mdk_rdev_t *rdev) @@ -520,12 +661,12 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev) PRINTK("raid5: error called\n"); if (!test_bit(Faulty, &rdev->flags)) { - mddev->sb_dirty = 1; - if (test_bit(In_sync, &rdev->flags)) { - conf->working_disks--; + set_bit(MD_CHANGE_DEVS, &mddev->flags); + if (test_and_clear_bit(In_sync, &rdev->flags)) { + unsigned long flags; + spin_lock_irqsave(&conf->device_lock, flags); mddev->degraded++; - conf->failed_disks++; - clear_bit(In_sync, &rdev->flags); + spin_unlock_irqrestore(&conf->device_lock, flags); /* * if recovery was running, make sure it aborts. */ @@ -535,9 +676,9 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev) printk (KERN_ALERT "raid5: Disk failure on %s, disabling device." " Operation continuing on %d devices\n", - bdevname(rdev->bdev,b), conf->working_disks); + bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded); } -} +} /* * Input: a 'big' sector number, @@ -575,9 +716,12 @@ static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks, /* * Select the parity disk based on the user selected algorithm. */ - if (conf->level == 4) + switch(conf->level) { + case 4: *pd_idx = data_disks; - else switch (conf->algorithm) { + break; + case 5: + switch (conf->algorithm) { case ALGORITHM_LEFT_ASYMMETRIC: *pd_idx = data_disks - stripe % raid_disks; if (*dd_idx >= *pd_idx) @@ -599,6 +743,39 @@ static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks, default: printk(KERN_ERR "raid5: unsupported algorithm %d\n", conf->algorithm); + } + break; + case 6: + + /**** FIX THIS ****/ + switch (conf->algorithm) { + case ALGORITHM_LEFT_ASYMMETRIC: + *pd_idx = raid_disks - 1 - (stripe % raid_disks); + if (*pd_idx == raid_disks-1) + (*dd_idx)++; /* Q D D D P */ + else if (*dd_idx >= *pd_idx) + (*dd_idx) += 2; /* D D P Q D */ + break; + case ALGORITHM_RIGHT_ASYMMETRIC: + *pd_idx = stripe % raid_disks; + if (*pd_idx == raid_disks-1) + (*dd_idx)++; /* Q D D D P */ + else if (*dd_idx >= *pd_idx) + (*dd_idx) += 2; /* D D P Q D */ + break; + case ALGORITHM_LEFT_SYMMETRIC: + *pd_idx = raid_disks - 1 - (stripe % raid_disks); + *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; + break; + case ALGORITHM_RIGHT_SYMMETRIC: + *pd_idx = stripe % raid_disks; + *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; + break; + default: + printk (KERN_CRIT "raid6: unsupported algorithm %d\n", + conf->algorithm); + } + break; } /* @@ -612,7 +789,8 @@ 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; + int data_disks = raid_disks - conf->max_degraded; sector_t new_sector = sh->sector, check; int sectors_per_chunk = conf->chunk_size >> 9; sector_t stripe; @@ -620,12 +798,17 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i) int chunk_number, dummy1, dummy2, dd_idx = i; sector_t r_sector; + chunk_offset = sector_div(new_sector, sectors_per_chunk); stripe = new_sector; BUG_ON(new_sector != stripe); - - switch (conf->algorithm) { + if (i == sh->pd_idx) + return 0; + switch(conf->level) { + case 4: break; + case 5: + switch (conf->algorithm) { case ALGORITHM_LEFT_ASYMMETRIC: case ALGORITHM_RIGHT_ASYMMETRIC: if (i > sh->pd_idx) @@ -639,7 +822,36 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i) break; default: printk(KERN_ERR "raid5: unsupported algorithm %d\n", + conf->algorithm); + } + break; + case 6: + if (i == raid6_next_disk(sh->pd_idx, raid_disks)) + return 0; /* It is the Q disk */ + switch (conf->algorithm) { + case ALGORITHM_LEFT_ASYMMETRIC: + case ALGORITHM_RIGHT_ASYMMETRIC: + if (sh->pd_idx == raid_disks-1) + i--; /* Q D D D P */ + else if (i > sh->pd_idx) + i -= 2; /* D D P Q D */ + break; + case ALGORITHM_LEFT_SYMMETRIC: + case ALGORITHM_RIGHT_SYMMETRIC: + if (sh->pd_idx == raid_disks-1) + i--; /* Q D D D P */ + else { + /* D D P Q D */ + if (i < sh->pd_idx) + i += raid_disks; + i -= (sh->pd_idx + 2); + } + break; + default: + printk (KERN_CRIT "raid6: unsupported algorithm %d\n", conf->algorithm); + } + break; } chunk_number = stripe * data_disks + i; @@ -656,10 +868,11 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i) /* - * Copy data between a page in the stripe cache, and a bio. - * There are no alignment or size guarantees between the page or the - * bio except that there is some overlap. - * All iovecs in the bio must be considered. + * Copy data between a page in the stripe cache, and one or more bion + * The page could align with the middle of the bio, or there could be + * several bion, each with several bio_vecs, which cover part of the page + * Multiple bion are linked together on bi_next. There may be extras + * at the end of this list. We ignore them. */ static void copy_data(int frombio, struct bio *bio, struct page *page, @@ -688,7 +901,7 @@ static void copy_data(int frombio, struct bio *bio, if (len > 0 && page_offset + len > STRIPE_SIZE) clen = STRIPE_SIZE - page_offset; else clen = len; - + if (clen > 0) { char *ba = __bio_kmap_atomic(bio, i, KM_USER0); if (frombio) @@ -713,8 +926,7 @@ 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", @@ -741,22 +953,21 @@ static void compute_block(struct stripe_head *sh, int dd_idx) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); } -static void compute_parity(struct stripe_head *sh, int method) +static void compute_parity5(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; - PRINTK("compute_parity, stripe %llu, method %d\n", + PRINTK("compute_parity5, stripe %llu, method %d\n", (unsigned long long)sh->sector, method); count = 1; ptr[0] = page_address(sh->dev[pd_idx].page); switch(method) { case READ_MODIFY_WRITE: - if (!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags)) - BUG(); + BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags)); for (i=disks ; i-- ;) { if (i==pd_idx) continue; @@ -769,7 +980,7 @@ static void compute_parity(struct stripe_head *sh, int method) if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) wake_up(&conf->wait_for_overlap); - if (sh->dev[i].written) BUG(); + BUG_ON(sh->dev[i].written); sh->dev[i].written = chosen; check_xor(); } @@ -785,7 +996,7 @@ static void compute_parity(struct stripe_head *sh, int method) if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) wake_up(&conf->wait_for_overlap); - if (sh->dev[i].written) BUG(); + BUG_ON(sh->dev[i].written); sh->dev[i].written = chosen; } break; @@ -836,9 +1047,195 @@ static void compute_parity(struct stripe_head *sh, int method) clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); } +static void compute_parity6(struct stripe_head *sh, int method) +{ + raid6_conf_t *conf = sh->raid_conf; + int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count; + struct bio *chosen; + /**** FIX THIS: This could be very bad if disks is close to 256 ****/ + void *ptrs[disks]; + + qd_idx = raid6_next_disk(pd_idx, disks); + d0_idx = raid6_next_disk(qd_idx, disks); + + PRINTK("compute_parity, stripe %llu, method %d\n", + (unsigned long long)sh->sector, method); + + switch(method) { + case READ_MODIFY_WRITE: + BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */ + case RECONSTRUCT_WRITE: + for (i= disks; i-- ;) + if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) { + chosen = sh->dev[i].towrite; + sh->dev[i].towrite = NULL; + + if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) + wake_up(&conf->wait_for_overlap); + + BUG_ON(sh->dev[i].written); + sh->dev[i].written = chosen; + } + break; + case CHECK_PARITY: + BUG(); /* Not implemented yet */ + } + + for (i = disks; i--;) + if (sh->dev[i].written) { + sector_t sector = sh->dev[i].sector; + struct bio *wbi = sh->dev[i].written; + while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { + copy_data(1, wbi, sh->dev[i].page, sector); + wbi = r5_next_bio(wbi, sector); + } + + set_bit(R5_LOCKED, &sh->dev[i].flags); + set_bit(R5_UPTODATE, &sh->dev[i].flags); + } + +// switch(method) { +// case RECONSTRUCT_WRITE: +// case CHECK_PARITY: +// case UPDATE_PARITY: + /* Note that unlike RAID-5, the ordering of the disks matters greatly. */ + /* FIX: Is this ordering of drives even remotely optimal? */ + count = 0; + i = d0_idx; + do { + ptrs[count++] = page_address(sh->dev[i].page); + if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags)) + printk("block %d/%d not uptodate on parity calc\n", i,count); + i = raid6_next_disk(i, disks); + } while ( i != d0_idx ); +// break; +// } + + raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs); + + switch(method) { + case RECONSTRUCT_WRITE: + set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); + set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); + set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); + set_bit(R5_LOCKED, &sh->dev[qd_idx].flags); + break; + case UPDATE_PARITY: + set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); + set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); + break; + } +} + + +/* Compute one missing block */ +static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero) +{ + raid6_conf_t *conf = sh->raid_conf; + int i, count, disks = conf->raid_disks; + void *ptr[MAX_XOR_BLOCKS], *p; + int pd_idx = sh->pd_idx; + int qd_idx = raid6_next_disk(pd_idx, disks); + + PRINTK("compute_block_1, stripe %llu, idx %d\n", + (unsigned long long)sh->sector, dd_idx); + + if ( dd_idx == qd_idx ) { + /* We're actually computing the Q drive */ + compute_parity6(sh, UPDATE_PARITY); + } else { + ptr[0] = page_address(sh->dev[dd_idx].page); + if (!nozero) memset(ptr[0], 0, STRIPE_SIZE); + count = 1; + for (i = disks ; i--; ) { + if (i == dd_idx || i == qd_idx) + continue; + p = page_address(sh->dev[i].page); + if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) + ptr[count++] = p; + else + printk("compute_block() %d, stripe %llu, %d" + " not present\n", dd_idx, + (unsigned long long)sh->sector, i); + + check_xor(); + } + if (count != 1) + xor_block(count, STRIPE_SIZE, ptr); + if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); + else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); + } +} + +/* Compute two missing blocks */ +static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2) +{ + raid6_conf_t *conf = sh->raid_conf; + int i, count, disks = conf->raid_disks; + int pd_idx = sh->pd_idx; + int qd_idx = raid6_next_disk(pd_idx, disks); + int d0_idx = raid6_next_disk(qd_idx, disks); + int faila, failb; + + /* faila and failb are disk numbers relative to d0_idx */ + /* pd_idx become disks-2 and qd_idx become disks-1 */ + faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx; + failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx; + + BUG_ON(faila == failb); + if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; } + + PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n", + (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb); + + if ( failb == disks-1 ) { + /* Q disk is one of the missing disks */ + if ( faila == disks-2 ) { + /* Missing P+Q, just recompute */ + compute_parity6(sh, UPDATE_PARITY); + return; + } else { + /* We're missing D+Q; recompute D from P */ + compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0); + compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */ + return; + } + } + + /* We're missing D+P or D+D; build pointer table */ + { + /**** FIX THIS: This could be very bad if disks is close to 256 ****/ + void *ptrs[disks]; + + count = 0; + i = d0_idx; + do { + ptrs[count++] = page_address(sh->dev[i].page); + i = raid6_next_disk(i, disks); + if (i != dd_idx1 && i != dd_idx2 && + !test_bit(R5_UPTODATE, &sh->dev[i].flags)) + printk("compute_2 with missing block %d/%d\n", count, i); + } while ( i != d0_idx ); + + if ( failb == disks-2 ) { + /* We're missing D+P. */ + raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs); + } else { + /* We're missing D+D. */ + raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs); + } + + /* Both the above update both missing blocks */ + set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags); + set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags); + } +} + + + /* * Each stripe/dev can have one or more bion attached. - * toread/towrite point to the first in a chain. + * toread/towrite point to the first in a chain. * The bi_next chain must be in order. */ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) @@ -868,8 +1265,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) goto overlap; - if (*bip && bi->bi_next && (*bip) != bi->bi_next) - BUG(); + BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); if (*bip) bi->bi_next = *bip; *bip = bi; @@ -882,9 +1278,9 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in (unsigned long long)sh->sector, dd_idx); if (conf->mddev->bitmap && firstwrite) { - sh->bm_seq = conf->seq_write; bitmap_startwrite(conf->mddev->bitmap, sh->sector, STRIPE_SECTORS, 0); + sh->bm_seq = conf->seq_flush+1; set_bit(STRIPE_BIT_DELAY, &sh->state); } @@ -910,6 +1306,28 @@ 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 page_is_zero(struct page *p) +{ + char *a = page_address(p); + return ((*(u32*)a) == 0 && + memcmp(a, a+4, STRIPE_SIZE-4)==0); +} + +static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks) +{ + int sectors_per_chunk = conf->chunk_size >> 9; + int pd_idx, dd_idx; + int chunk_offset = sector_div(stripe, sectors_per_chunk); + + raid5_compute_sector(stripe * (disks - conf->max_degraded) + *sectors_per_chunk + chunk_offset, + disks, disks - conf->max_degraded, + &dd_idx, &pd_idx, conf); + return pd_idx; +} + /* * handle_stripe - do things to a stripe. @@ -929,14 +1347,14 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in * */ -static void handle_stripe(struct stripe_head *sh) +static void handle_stripe5(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 +1369,8 @@ 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 +1563,14 @@ 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)))) ) @@ -1164,15 +1585,6 @@ static void handle_stripe(struct stripe_head *sh) } else if (test_bit(R5_Insync, &dev->flags)) { set_bit(R5_LOCKED, &dev->flags); set_bit(R5_Wantread, &dev->flags); -#if 0 - /* if I am just reading this block and we don't have - a failed drive, or any pending writes then sidestep the cache */ - if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && - ! syncing && !failed && !to_write) { - sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; - sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; - } -#endif locked++; PRINTK("Reading block %d (sync=%d)\n", i, syncing); @@ -1190,9 +1602,6 @@ static void handle_stripe(struct stripe_head *sh) dev = &sh->dev[i]; if ((dev->towrite || i == sh->pd_idx) && (!test_bit(R5_LOCKED, &dev->flags) -#if 0 -|| sh->bh_page[i]!=bh->b_page -#endif ) && !test_bit(R5_UPTODATE, &dev->flags)) { if (test_bit(R5_Insync, &dev->flags) @@ -1204,9 +1613,6 @@ static void handle_stripe(struct stripe_head *sh) /* Would I have to read this buffer for reconstruct_write */ if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && (!test_bit(R5_LOCKED, &dev->flags) -#if 0 -|| sh->bh_page[i] != bh->b_page -#endif ) && !test_bit(R5_UPTODATE, &dev->flags)) { if (test_bit(R5_Insync, &dev->flags)) rcw++; @@ -1258,7 +1664,7 @@ static void handle_stripe(struct stripe_head *sh) if (locked == 0 && (rcw == 0 ||rmw == 0) && !test_bit(STRIPE_BIT_DELAY, &sh->state)) { PRINTK("Computing parity...\n"); - compute_parity(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE); + compute_parity5(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE); /* now every locked buffer is ready to be written */ for (i=disks; i--;) if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { @@ -1285,14 +1691,10 @@ static void handle_stripe(struct stripe_head *sh) !test_bit(STRIPE_INSYNC, &sh->state)) { set_bit(STRIPE_HANDLE, &sh->state); if (failed == 0) { - char *pagea; - if (uptodate != disks) - BUG(); - compute_parity(sh, CHECK_PARITY); + BUG_ON(uptodate != disks); + compute_parity5(sh, CHECK_PARITY); uptodate--; - pagea = page_address(sh->dev[sh->pd_idx].page); - if ((*(u32*)pagea) == 0 && - !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) { + if (page_is_zero(sh->dev[sh->pd_idx].page)) { /* parity is correct (on disc, not in buffer any more) */ set_bit(STRIPE_INSYNC, &sh->state); } else { @@ -1339,11 +1741,75 @@ 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_parity5(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; jraid_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); @@ -1354,23 +1820,25 @@ static void handle_stripe(struct stripe_head *sh) return_bi = bi->bi_next; bi->bi_next = NULL; bi->bi_size = 0; - bi->bi_end_io(bi, bytes, 0); + bi->bi_end_io(bi, bytes, + test_bit(BIO_UPTODATE, &bi->bi_flags) + ? 0 : -EIO); } for (i=disks; i-- ;) { int rw; struct bio *bi; mdk_rdev_t *rdev; if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) - rw = 1; + rw = WRITE; else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) - rw = 0; + rw = READ; else continue; bi = &sh->dev[i].req; bi->bi_rw = rw; - if (rw) + if (rw == WRITE) bi->bi_end_io = raid5_end_write_request; else bi->bi_end_io = raid5_end_read_request; @@ -1384,7 +1852,7 @@ 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; @@ -1406,7 +1874,7 @@ static void handle_stripe(struct stripe_head *sh) atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); generic_make_request(bi); } else { - if (rw == 1) + if (rw == WRITE) set_bit(STRIPE_DEGRADED, &sh->state); PRINTK("skip op %ld on disc %d for sector %llu\n", bi->bi_rw, i, (unsigned long long)sh->sector); @@ -1416,32 +1884,585 @@ static void handle_stripe(struct stripe_head *sh) } } -static void raid5_activate_delayed(raid5_conf_t *conf) +static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page) { - if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { - while (!list_empty(&conf->delayed_list)) { - struct list_head *l = conf->delayed_list.next; - struct stripe_head *sh; - sh = list_entry(l, struct stripe_head, lru); - list_del_init(l); - clear_bit(STRIPE_DELAYED, &sh->state); - if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) - atomic_inc(&conf->preread_active_stripes); - list_add_tail(&sh->lru, &conf->handle_list); - } - } -} + raid6_conf_t *conf = sh->raid_conf; + int disks = conf->raid_disks; + struct bio *return_bi= NULL; + struct bio *bi; + int i; + int syncing; + int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; + int non_overwrite = 0; + int failed_num[2] = {0, 0}; + struct r5dev *dev, *pdev, *qdev; + int pd_idx = sh->pd_idx; + int qd_idx = raid6_next_disk(pd_idx, disks); + int p_failed, q_failed; -static void activate_bit_delay(raid5_conf_t *conf) -{ - /* device_lock is held */ - struct list_head head; - list_add(&head, &conf->bitmap_list); - list_del_init(&conf->bitmap_list); - while (!list_empty(&head)) { - struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); - list_del_init(&sh->lru); - atomic_inc(&sh->count); + PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n", + (unsigned long long)sh->sector, sh->state, atomic_read(&sh->count), + pd_idx, qd_idx); + + spin_lock(&sh->lock); + clear_bit(STRIPE_HANDLE, &sh->state); + clear_bit(STRIPE_DELAYED, &sh->state); + + syncing = test_bit(STRIPE_SYNCING, &sh->state); + /* Now to look around and see what can be done */ + + rcu_read_lock(); + for (i=disks; i--; ) { + mdk_rdev_t *rdev; + dev = &sh->dev[i]; + clear_bit(R5_Insync, &dev->flags); + + PRINTK("check %d: state 0x%lx read %p write %p written %p\n", + i, dev->flags, dev->toread, dev->towrite, dev->written); + /* maybe we can reply to a read */ + if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { + struct bio *rbi, *rbi2; + PRINTK("Return read for disc %d\n", i); + spin_lock_irq(&conf->device_lock); + rbi = dev->toread; + dev->toread = NULL; + if (test_and_clear_bit(R5_Overlap, &dev->flags)) + wake_up(&conf->wait_for_overlap); + spin_unlock_irq(&conf->device_lock); + while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { + copy_data(0, rbi, dev->page, dev->sector); + rbi2 = r5_next_bio(rbi, dev->sector); + spin_lock_irq(&conf->device_lock); + if (--rbi->bi_phys_segments == 0) { + rbi->bi_next = return_bi; + return_bi = rbi; + } + spin_unlock_irq(&conf->device_lock); + rbi = rbi2; + } + } + + /* now count some things */ + if (test_bit(R5_LOCKED, &dev->flags)) locked++; + if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; + + + if (dev->toread) to_read++; + if (dev->towrite) { + to_write++; + if (!test_bit(R5_OVERWRITE, &dev->flags)) + non_overwrite++; + } + if (dev->written) written++; + rdev = rcu_dereference(conf->disks[i].rdev); + if (!rdev || !test_bit(In_sync, &rdev->flags)) { + /* The ReadError flag will just be confusing now */ + clear_bit(R5_ReadError, &dev->flags); + clear_bit(R5_ReWrite, &dev->flags); + } + if (!rdev || !test_bit(In_sync, &rdev->flags) + || test_bit(R5_ReadError, &dev->flags)) { + if ( failed < 2 ) + failed_num[failed] = i; + failed++; + } else + set_bit(R5_Insync, &dev->flags); + } + rcu_read_unlock(); + PRINTK("locked=%d uptodate=%d to_read=%d" + " to_write=%d failed=%d failed_num=%d,%d\n", + locked, uptodate, to_read, to_write, failed, + failed_num[0], failed_num[1]); + /* check if the array has lost >2 devices and, if so, some requests might + * need to be failed + */ + if (failed > 2 && to_read+to_write+written) { + for (i=disks; i--; ) { + int bitmap_end = 0; + + if (test_bit(R5_ReadError, &sh->dev[i].flags)) { + mdk_rdev_t *rdev; + rcu_read_lock(); + rdev = rcu_dereference(conf->disks[i].rdev); + if (rdev && test_bit(In_sync, &rdev->flags)) + /* multiple read failures in one stripe */ + md_error(conf->mddev, rdev); + rcu_read_unlock(); + } + + spin_lock_irq(&conf->device_lock); + /* fail all writes first */ + bi = sh->dev[i].towrite; + sh->dev[i].towrite = NULL; + if (bi) { to_write--; bitmap_end = 1; } + + if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) + wake_up(&conf->wait_for_overlap); + + while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ + struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); + clear_bit(BIO_UPTODATE, &bi->bi_flags); + if (--bi->bi_phys_segments == 0) { + md_write_end(conf->mddev); + bi->bi_next = return_bi; + return_bi = bi; + } + bi = nextbi; + } + /* and fail all 'written' */ + bi = sh->dev[i].written; + sh->dev[i].written = NULL; + if (bi) bitmap_end = 1; + while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { + struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); + clear_bit(BIO_UPTODATE, &bi->bi_flags); + if (--bi->bi_phys_segments == 0) { + md_write_end(conf->mddev); + bi->bi_next = return_bi; + return_bi = bi; + } + bi = bi2; + } + + /* fail any reads if this device is non-operational */ + if (!test_bit(R5_Insync, &sh->dev[i].flags) || + test_bit(R5_ReadError, &sh->dev[i].flags)) { + bi = sh->dev[i].toread; + sh->dev[i].toread = NULL; + if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) + wake_up(&conf->wait_for_overlap); + if (bi) to_read--; + while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ + struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); + clear_bit(BIO_UPTODATE, &bi->bi_flags); + if (--bi->bi_phys_segments == 0) { + bi->bi_next = return_bi; + return_bi = bi; + } + bi = nextbi; + } + } + spin_unlock_irq(&conf->device_lock); + if (bitmap_end) + bitmap_endwrite(conf->mddev->bitmap, sh->sector, + STRIPE_SECTORS, 0, 0); + } + } + if (failed > 2 && syncing) { + md_done_sync(conf->mddev, STRIPE_SECTORS,0); + clear_bit(STRIPE_SYNCING, &sh->state); + syncing = 0; + } + + /* + * might be able to return some write requests if the parity blocks + * are safe, or on a failed drive + */ + pdev = &sh->dev[pd_idx]; + p_failed = (failed >= 1 && failed_num[0] == pd_idx) + || (failed >= 2 && failed_num[1] == pd_idx); + qdev = &sh->dev[qd_idx]; + q_failed = (failed >= 1 && failed_num[0] == qd_idx) + || (failed >= 2 && failed_num[1] == qd_idx); + + if ( written && + ( p_failed || ((test_bit(R5_Insync, &pdev->flags) + && !test_bit(R5_LOCKED, &pdev->flags) + && test_bit(R5_UPTODATE, &pdev->flags))) ) && + ( q_failed || ((test_bit(R5_Insync, &qdev->flags) + && !test_bit(R5_LOCKED, &qdev->flags) + && test_bit(R5_UPTODATE, &qdev->flags))) ) ) { + /* any written block on an uptodate or failed drive can be + * returned. Note that if we 'wrote' to a failed drive, + * it will be UPTODATE, but never LOCKED, so we don't need + * to test 'failed' directly. + */ + for (i=disks; i--; ) + if (sh->dev[i].written) { + dev = &sh->dev[i]; + if (!test_bit(R5_LOCKED, &dev->flags) && + test_bit(R5_UPTODATE, &dev->flags) ) { + /* We can return any write requests */ + int bitmap_end = 0; + struct bio *wbi, *wbi2; + PRINTK("Return write for stripe %llu disc %d\n", + (unsigned long long)sh->sector, i); + spin_lock_irq(&conf->device_lock); + wbi = dev->written; + dev->written = NULL; + while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { + wbi2 = r5_next_bio(wbi, dev->sector); + if (--wbi->bi_phys_segments == 0) { + md_write_end(conf->mddev); + wbi->bi_next = return_bi; + return_bi = wbi; + } + wbi = wbi2; + } + if (dev->towrite == NULL) + bitmap_end = 1; + spin_unlock_irq(&conf->device_lock); + if (bitmap_end) + bitmap_endwrite(conf->mddev->bitmap, sh->sector, + STRIPE_SECTORS, + !test_bit(STRIPE_DEGRADED, &sh->state), 0); + } + } + } + + /* Now we might consider reading some blocks, either to check/generate + * parity, or to satisfy requests + * or to load a block that is being partially written. + */ + if (to_read || non_overwrite || (to_write && failed) || (syncing && (uptodate < disks))) { + 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 || + (failed >= 1 && (sh->dev[failed_num[0]].toread || to_write)) || + (failed >= 2 && (sh->dev[failed_num[1]].toread || to_write)) + ) + ) { + /* we would like to get this block, possibly + * by computing it, but we might not be able to + */ + if (uptodate == disks-1) { + PRINTK("Computing stripe %llu block %d\n", + (unsigned long long)sh->sector, i); + compute_block_1(sh, i, 0); + uptodate++; + } else if ( uptodate == disks-2 && failed >= 2 ) { + /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */ + int other; + for (other=disks; other--;) { + if ( other == i ) + continue; + if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) ) + break; + } + BUG_ON(other < 0); + PRINTK("Computing stripe %llu blocks %d,%d\n", + (unsigned long long)sh->sector, i, other); + compute_block_2(sh, i, other); + uptodate += 2; + } else if (test_bit(R5_Insync, &dev->flags)) { + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantread, &dev->flags); + locked++; + PRINTK("Reading block %d (sync=%d)\n", + i, syncing); + } + } + } + set_bit(STRIPE_HANDLE, &sh->state); + } + + /* now to consider writing and what else, if anything should be read */ + if (to_write) { + int rcw=0, must_compute=0; + for (i=disks ; i--;) { + dev = &sh->dev[i]; + /* Would I have to read this buffer for reconstruct_write */ + if (!test_bit(R5_OVERWRITE, &dev->flags) + && i != pd_idx && i != qd_idx + && (!test_bit(R5_LOCKED, &dev->flags) + ) && + !test_bit(R5_UPTODATE, &dev->flags)) { + if (test_bit(R5_Insync, &dev->flags)) rcw++; + else { + PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags); + must_compute++; + } + } + } + PRINTK("for sector %llu, rcw=%d, must_compute=%d\n", + (unsigned long long)sh->sector, rcw, must_compute); + set_bit(STRIPE_HANDLE, &sh->state); + + if (rcw > 0) + /* want reconstruct write, but need to get some data */ + for (i=disks; i--;) { + dev = &sh->dev[i]; + if (!test_bit(R5_OVERWRITE, &dev->flags) + && !(failed == 0 && (i == pd_idx || i == qd_idx)) + && !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && + test_bit(R5_Insync, &dev->flags)) { + if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + { + PRINTK("Read_old stripe %llu block %d for Reconstruct\n", + (unsigned long long)sh->sector, i); + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantread, &dev->flags); + locked++; + } else { + PRINTK("Request delayed stripe %llu block %d for Reconstruct\n", + (unsigned long long)sh->sector, i); + set_bit(STRIPE_DELAYED, &sh->state); + set_bit(STRIPE_HANDLE, &sh->state); + } + } + } + /* now if nothing is locked, and if we have enough data, we can start a write request */ + if (locked == 0 && rcw == 0 && + !test_bit(STRIPE_BIT_DELAY, &sh->state)) { + if ( must_compute > 0 ) { + /* We have failed blocks and need to compute them */ + switch ( failed ) { + case 0: BUG(); + case 1: compute_block_1(sh, failed_num[0], 0); break; + case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break; + default: BUG(); /* This request should have been failed? */ + } + } + + PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector); + compute_parity6(sh, RECONSTRUCT_WRITE); + /* now every locked buffer is ready to be written */ + for (i=disks; i--;) + if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { + PRINTK("Writing stripe %llu block %d\n", + (unsigned long long)sh->sector, i); + locked++; + set_bit(R5_Wantwrite, &sh->dev[i].flags); + } + /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */ + set_bit(STRIPE_INSYNC, &sh->state); + + if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { + atomic_dec(&conf->preread_active_stripes); + if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) + md_wakeup_thread(conf->mddev->thread); + } + } + } + + /* maybe we need to check and possibly fix the parity for this stripe + * Any reads will already have been scheduled, so we just see if enough data + * is available + */ + if (syncing && locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) { + int update_p = 0, update_q = 0; + struct r5dev *dev; + + set_bit(STRIPE_HANDLE, &sh->state); + + BUG_ON(failed>2); + BUG_ON(uptodate < disks); + /* Want to check and possibly repair P and Q. + * However there could be one 'failed' device, in which + * case we can only check one of them, possibly using the + * other to generate missing data + */ + + /* If !tmp_page, we cannot do the calculations, + * but as we have set STRIPE_HANDLE, we will soon be called + * by stripe_handle with a tmp_page - just wait until then. + */ + if (tmp_page) { + if (failed == q_failed) { + /* The only possible failed device holds 'Q', so it makes + * sense to check P (If anything else were failed, we would + * have used P to recreate it). + */ + compute_block_1(sh, pd_idx, 1); + if (!page_is_zero(sh->dev[pd_idx].page)) { + compute_block_1(sh,pd_idx,0); + update_p = 1; + } + } + if (!q_failed && failed < 2) { + /* q is not failed, and we didn't use it to generate + * anything, so it makes sense to check it + */ + memcpy(page_address(tmp_page), + page_address(sh->dev[qd_idx].page), + STRIPE_SIZE); + compute_parity6(sh, UPDATE_PARITY); + if (memcmp(page_address(tmp_page), + page_address(sh->dev[qd_idx].page), + STRIPE_SIZE)!= 0) { + clear_bit(STRIPE_INSYNC, &sh->state); + update_q = 1; + } + } + if (update_p || update_q) { + conf->mddev->resync_mismatches += STRIPE_SECTORS; + if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) + /* don't try to repair!! */ + update_p = update_q = 0; + } + + /* now write out any block on a failed drive, + * or P or Q if they need it + */ + + if (failed == 2) { + dev = &sh->dev[failed_num[1]]; + locked++; + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantwrite, &dev->flags); + } + if (failed >= 1) { + dev = &sh->dev[failed_num[0]]; + locked++; + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantwrite, &dev->flags); + } + + if (update_p) { + dev = &sh->dev[pd_idx]; + locked ++; + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantwrite, &dev->flags); + } + if (update_q) { + dev = &sh->dev[qd_idx]; + locked++; + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantwrite, &dev->flags); + } + clear_bit(STRIPE_DEGRADED, &sh->state); + + set_bit(STRIPE_INSYNC, &sh->state); + } + } + + if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { + md_done_sync(conf->mddev, STRIPE_SECTORS,1); + clear_bit(STRIPE_SYNCING, &sh->state); + } + + /* If the failed drives are just a ReadError, then we might need + * to progress the repair/check process + */ + if (failed <= 2 && ! conf->mddev->ro) + for (i=0; idev[failed_num[i]]; + if (test_bit(R5_ReadError, &dev->flags) + && !test_bit(R5_LOCKED, &dev->flags) + && test_bit(R5_UPTODATE, &dev->flags) + ) { + if (!test_bit(R5_ReWrite, &dev->flags)) { + set_bit(R5_Wantwrite, &dev->flags); + set_bit(R5_ReWrite, &dev->flags); + set_bit(R5_LOCKED, &dev->flags); + } else { + /* let's read it back */ + set_bit(R5_Wantread, &dev->flags); + set_bit(R5_LOCKED, &dev->flags); + } + } + } + spin_unlock(&sh->lock); + + while ((bi=return_bi)) { + int bytes = bi->bi_size; + + return_bi = bi->bi_next; + bi->bi_next = NULL; + bi->bi_size = 0; + bi->bi_end_io(bi, bytes, + test_bit(BIO_UPTODATE, &bi->bi_flags) + ? 0 : -EIO); + } + for (i=disks; i-- ;) { + int rw; + struct bio *bi; + mdk_rdev_t *rdev; + if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) + rw = WRITE; + else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) + rw = READ; + else + continue; + + bi = &sh->dev[i].req; + + bi->bi_rw = rw; + if (rw == WRITE) + bi->bi_end_io = raid5_end_write_request; + else + bi->bi_end_io = raid5_end_read_request; + + rcu_read_lock(); + rdev = rcu_dereference(conf->disks[i].rdev); + if (rdev && test_bit(Faulty, &rdev->flags)) + rdev = NULL; + if (rdev) + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + + if (rdev) { + if (syncing) + md_sync_acct(rdev->bdev, STRIPE_SECTORS); + + bi->bi_bdev = rdev->bdev; + PRINTK("for %llu schedule op %ld on disc %d\n", + (unsigned long long)sh->sector, bi->bi_rw, i); + atomic_inc(&sh->count); + bi->bi_sector = sh->sector + rdev->data_offset; + bi->bi_flags = 1 << BIO_UPTODATE; + bi->bi_vcnt = 1; + bi->bi_max_vecs = 1; + bi->bi_idx = 0; + bi->bi_io_vec = &sh->dev[i].vec; + bi->bi_io_vec[0].bv_len = STRIPE_SIZE; + bi->bi_io_vec[0].bv_offset = 0; + bi->bi_size = STRIPE_SIZE; + bi->bi_next = NULL; + if (rw == WRITE && + test_bit(R5_ReWrite, &sh->dev[i].flags)) + atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); + generic_make_request(bi); + } else { + if (rw == WRITE) + set_bit(STRIPE_DEGRADED, &sh->state); + PRINTK("skip op %ld on disc %d for sector %llu\n", + bi->bi_rw, i, (unsigned long long)sh->sector); + clear_bit(R5_LOCKED, &sh->dev[i].flags); + set_bit(STRIPE_HANDLE, &sh->state); + } + } +} + +static void handle_stripe(struct stripe_head *sh, struct page *tmp_page) +{ + if (sh->raid_conf->level == 6) + handle_stripe6(sh, tmp_page); + else + handle_stripe5(sh); +} + + + +static void raid5_activate_delayed(raid5_conf_t *conf) +{ + if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { + while (!list_empty(&conf->delayed_list)) { + struct list_head *l = conf->delayed_list.next; + struct stripe_head *sh; + sh = list_entry(l, struct stripe_head, lru); + list_del_init(l); + clear_bit(STRIPE_DELAYED, &sh->state); + if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + atomic_inc(&conf->preread_active_stripes); + list_add_tail(&sh->lru, &conf->handle_list); + } + } +} + +static void activate_bit_delay(raid5_conf_t *conf) +{ + /* device_lock is held */ + struct list_head head; + list_add(&head, &conf->bitmap_list); + list_del_init(&conf->bitmap_list); + while (!list_empty(&head)) { + struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); + list_del_init(&sh->lru); + atomic_inc(&sh->count); __release_stripe(conf, sh); } } @@ -1484,59 +2505,271 @@ static void raid5_unplug_device(request_queue_t *q) } md_wakeup_thread(mddev->thread); - spin_unlock_irqrestore(&conf->device_lock, flags); + spin_unlock_irqrestore(&conf->device_lock, flags); + + unplug_slaves(mddev); +} + +static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk, + sector_t *error_sector) +{ + mddev_t *mddev = q->queuedata; + raid5_conf_t *conf = mddev_to_conf(mddev); + int i, ret = 0; + + rcu_read_lock(); + for (i=0; iraid_disks && ret == 0; i++) { + mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); + if (rdev && !test_bit(Faulty, &rdev->flags)) { + struct block_device *bdev = rdev->bdev; + request_queue_t *r_queue = bdev_get_queue(bdev); + + if (!r_queue->issue_flush_fn) + ret = -EOPNOTSUPP; + else { + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, + error_sector); + rdev_dec_pending(rdev, mddev); + rcu_read_lock(); + } + } + } + rcu_read_unlock(); + return ret; +} + +static int raid5_congested(void *data, int bits) +{ + mddev_t *mddev = data; + raid5_conf_t *conf = mddev_to_conf(mddev); + + /* No difference between reads and writes. Just check + * how busy the stripe_cache is + */ + if (conf->inactive_blocked) + return 1; + if (conf->quiesce) + return 1; + if (list_empty_careful(&conf->inactive_list)) + return 1; + + return 0; +} + +/* We want read requests to align with chunks where possible, + * but write requests don't need to. + */ +static int raid5_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec) +{ + mddev_t *mddev = q->queuedata; + sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); + int max; + unsigned int chunk_sectors = mddev->chunk_size >> 9; + unsigned int bio_sectors = bio->bi_size >> 9; + + if (bio_data_dir(bio) == WRITE) + return biovec->bv_len; /* always allow writes to be mergeable */ + + max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; + if (max < 0) max = 0; + if (max <= biovec->bv_len && bio_sectors == 0) + return biovec->bv_len; + else + return max; +} + + +static int in_chunk_boundary(mddev_t *mddev, struct bio *bio) +{ + sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); + unsigned int chunk_sectors = mddev->chunk_size >> 9; + unsigned int bio_sectors = bio->bi_size >> 9; + + return chunk_sectors >= + ((sector & (chunk_sectors - 1)) + bio_sectors); +} + +/* + * add bio to the retry LIFO ( in O(1) ... we are in interrupt ) + * later sampled by raid5d. + */ +static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf) +{ + unsigned long flags; + + spin_lock_irqsave(&conf->device_lock, flags); + + bi->bi_next = conf->retry_read_aligned_list; + conf->retry_read_aligned_list = bi; + + spin_unlock_irqrestore(&conf->device_lock, flags); + md_wakeup_thread(conf->mddev->thread); +} + + +static struct bio *remove_bio_from_retry(raid5_conf_t *conf) +{ + struct bio *bi; + + bi = conf->retry_read_aligned; + if (bi) { + conf->retry_read_aligned = NULL; + return bi; + } + bi = conf->retry_read_aligned_list; + if(bi) { + conf->retry_read_aligned_list = bi->bi_next; + bi->bi_next = NULL; + bi->bi_phys_segments = 1; /* biased count of active stripes */ + bi->bi_hw_segments = 0; /* count of processed stripes */ + } + + return bi; +} + + +/* + * The "raid5_align_endio" should check if the read succeeded and if it + * did, call bio_endio on the original bio (having bio_put the new bio + * first). + * If the read failed.. + */ +static int raid5_align_endio(struct bio *bi, unsigned int bytes, int error) +{ + struct bio* raid_bi = bi->bi_private; + mddev_t *mddev; + raid5_conf_t *conf; + int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); + mdk_rdev_t *rdev; + + if (bi->bi_size) + return 1; + bio_put(bi); + + mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata; + conf = mddev_to_conf(mddev); + rdev = (void*)raid_bi->bi_next; + raid_bi->bi_next = NULL; + + rdev_dec_pending(rdev, conf->mddev); + + if (!error && uptodate) { + bio_endio(raid_bi, bytes, 0); + if (atomic_dec_and_test(&conf->active_aligned_reads)) + wake_up(&conf->wait_for_stripe); + return 0; + } + + + PRINTK("raid5_align_endio : io error...handing IO for a retry\n"); + + add_bio_to_retry(raid_bi, conf); + return 0; +} + +static int bio_fits_rdev(struct bio *bi) +{ + request_queue_t *q = bdev_get_queue(bi->bi_bdev); + + if ((bi->bi_size>>9) > q->max_sectors) + return 0; + blk_recount_segments(q, bi); + if (bi->bi_phys_segments > q->max_phys_segments || + bi->bi_hw_segments > q->max_hw_segments) + return 0; - unplug_slaves(mddev); + if (q->merge_bvec_fn) + /* it's too hard to apply the merge_bvec_fn at this stage, + * just just give up + */ + return 0; + + return 1; } -static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk, - sector_t *error_sector) + +static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio) { mddev_t *mddev = q->queuedata; raid5_conf_t *conf = mddev_to_conf(mddev); - int i, ret = 0; + const unsigned int raid_disks = conf->raid_disks; + const unsigned int data_disks = raid_disks - conf->max_degraded; + unsigned int dd_idx, pd_idx; + struct bio* align_bi; + mdk_rdev_t *rdev; - rcu_read_lock(); - for (i=0; iraid_disks && ret == 0; i++) { - mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); - if (rdev && !test_bit(Faulty, &rdev->flags)) { - struct block_device *bdev = rdev->bdev; - request_queue_t *r_queue = bdev_get_queue(bdev); + if (!in_chunk_boundary(mddev, raid_bio)) { + PRINTK("chunk_aligned_read : non aligned\n"); + return 0; + } + /* + * use bio_clone to make a copy of the bio + */ + align_bi = bio_clone(raid_bio, GFP_NOIO); + if (!align_bi) + return 0; + /* + * set bi_end_io to a new function, and set bi_private to the + * original bio. + */ + align_bi->bi_end_io = raid5_align_endio; + align_bi->bi_private = raid_bio; + /* + * compute position + */ + align_bi->bi_sector = raid5_compute_sector(raid_bio->bi_sector, + raid_disks, + data_disks, + &dd_idx, + &pd_idx, + conf); - if (!r_queue->issue_flush_fn) - ret = -EOPNOTSUPP; - else { - atomic_inc(&rdev->nr_pending); - rcu_read_unlock(); - ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, - error_sector); - rdev_dec_pending(rdev, mddev); - rcu_read_lock(); - } + rcu_read_lock(); + rdev = rcu_dereference(conf->disks[dd_idx].rdev); + if (rdev && test_bit(In_sync, &rdev->flags)) { + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + raid_bio->bi_next = (void*)rdev; + align_bi->bi_bdev = rdev->bdev; + align_bi->bi_flags &= ~(1 << BIO_SEG_VALID); + align_bi->bi_sector += rdev->data_offset; + + if (!bio_fits_rdev(align_bi)) { + /* too big in some way */ + bio_put(align_bi); + rdev_dec_pending(rdev, mddev); + return 0; } + + spin_lock_irq(&conf->device_lock); + wait_event_lock_irq(conf->wait_for_stripe, + conf->quiesce == 0, + conf->device_lock, /* nothing */); + atomic_inc(&conf->active_aligned_reads); + spin_unlock_irq(&conf->device_lock); + + generic_make_request(align_bi); + return 1; + } else { + rcu_read_unlock(); + bio_put(align_bi); + return 0; } - rcu_read_unlock(); - return ret; } -static inline void raid5_plug_device(raid5_conf_t *conf) -{ - spin_lock_irq(&conf->device_lock); - blk_plug_device(conf->mddev->queue); - 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); @@ -1548,6 +2781,11 @@ static int make_request (request_queue_t *q, struct bio * bi) disk_stat_inc(mddev->gendisk, ios[rw]); disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); + if (rw == READ && + mddev->reshape_position == MaxSector && + chunk_aligned_read(q,bi)) + return 0; + logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); last_sector = bi->bi_sector + (bi->bi_size>>9); bi->bi_next = NULL; @@ -1555,20 +2793,79 @@ 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, data_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); + } + data_disks = disks - conf->max_degraded; + + new_sector = raid5_compute_sector(logical_sector, disks, data_disks, + &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); @@ -1577,10 +2874,8 @@ static int make_request (request_queue_t *q, struct bio * bi) goto retry; } finish_wait(&conf->wait_for_overlap, &w); - raid5_plug_device(conf); - handle_stripe(sh); + handle_stripe(sh, NULL); release_stripe(sh); - } else { /* cannot get stripe for read-ahead, just give-up */ clear_bit(BIO_UPTODATE, &bi->bi_flags); @@ -1590,52 +2885,184 @@ 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 ) + if ( rw == WRITE ) md_write_end(mddev); bi->bi_size = 0; - bi->bi_end_io(bi, bytes, 0); + bi->bi_end_io(bi, bytes, + test_bit(BIO_UPTODATE, &bi->bi_flags) + ? 0 : -EIO); } - spin_unlock_irq(&conf->device_lock); return 0; } +static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped) +{ + /* 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. + */ + raid5_conf_t *conf = (raid5_conf_t *) mddev->private; + struct stripe_head *sh; + int pd_idx; + sector_t first_sector, last_sector; + int raid_disks; + int data_disks; + 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; + set_bit(MD_CHANGE_DEVS, &mddev->flags); + md_wakeup_thread(mddev->thread); + wait_event(mddev->sb_wait, mddev->flags == 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; +} + /* FIXME go_faster isn't used */ -static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) +static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) { 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; int raid_disks = conf->raid_disks; - int data_disks = raid_disks-1; sector_t max_sector = mddev->size << 1; int sync_blocks; + int still_degraded = 0; + int 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, &sync_blocks, 1); - else /* compelted sync */ + else /* completed sync */ conf->fullsync = 0; bitmap_close_sync(mddev->bitmap); return 0; } - /* if there is 1 or more failed drives and we are trying + + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) + return reshape_request(mddev, sector_nr, skipped); + + /* if there is too many failed drives and we are trying * to resync, then assert that we are finished, because there is * nothing we can do. */ - if (mddev->degraded >= 1 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { + if (mddev->degraded >= conf->max_degraded && + test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { sector_t rv = (mddev->size << 1) - sector_nr; *skipped = 1; return rv; @@ -1649,33 +3076,112 @@ 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 + * is trying to get access */ schedule_timeout_uninterruptible(1); } - bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 0); - spin_lock(&sh->lock); + /* Need to check if array will still be degraded after recovery/resync + * We don't need to check the 'failed' flag as when that gets set, + * recovery aborts. + */ + for (i=0; iraid_disks; i++) + if (conf->disks[i].rdev == NULL) + still_degraded = 1; + + bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); + + spin_lock(&sh->lock); set_bit(STRIPE_SYNCING, &sh->state); clear_bit(STRIPE_INSYNC, &sh->state); spin_unlock(&sh->lock); - handle_stripe(sh); + handle_stripe(sh, NULL); release_stripe(sh); return STRIPE_SECTORS; } +static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) +{ + /* We may not be able to submit a whole bio at once as there + * may not be enough stripe_heads available. + * We cannot pre-allocate enough stripe_heads as we may need + * more than exist in the cache (if we allow ever large chunks). + * So we do one stripe head at a time and record in + * ->bi_hw_segments how many have been done. + * + * We *know* that this entire raid_bio is in one chunk, so + * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. + */ + struct stripe_head *sh; + int dd_idx, pd_idx; + sector_t sector, logical_sector, last_sector; + int scnt = 0; + int remaining; + int handled = 0; + + logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); + sector = raid5_compute_sector( logical_sector, + conf->raid_disks, + conf->raid_disks - conf->max_degraded, + &dd_idx, + &pd_idx, + conf); + last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); + + for (; logical_sector < last_sector; + logical_sector += STRIPE_SECTORS, + sector += STRIPE_SECTORS, + scnt++) { + + if (scnt < raid_bio->bi_hw_segments) + /* already done this stripe */ + continue; + + sh = get_active_stripe(conf, sector, conf->raid_disks, pd_idx, 1); + + if (!sh) { + /* failed to get a stripe - must wait */ + raid_bio->bi_hw_segments = scnt; + conf->retry_read_aligned = raid_bio; + return handled; + } + + set_bit(R5_ReadError, &sh->dev[dd_idx].flags); + if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { + release_stripe(sh); + raid_bio->bi_hw_segments = scnt; + conf->retry_read_aligned = raid_bio; + return handled; + } + + handle_stripe(sh, NULL); + release_stripe(sh); + handled++; + } + spin_lock_irq(&conf->device_lock); + remaining = --raid_bio->bi_phys_segments; + spin_unlock_irq(&conf->device_lock); + if (remaining == 0) { + int bytes = raid_bio->bi_size; + + raid_bio->bi_size = 0; + raid_bio->bi_end_io(raid_bio, bytes, + test_bit(BIO_UPTODATE, &raid_bio->bi_flags) + ? 0 : -EIO); + } + if (atomic_dec_and_test(&conf->active_aligned_reads)) + wake_up(&conf->wait_for_stripe); + return handled; +} + + + /* * This is our raid5 kernel thread. * @@ -1697,8 +3203,9 @@ static void raid5d (mddev_t *mddev) spin_lock_irq(&conf->device_lock); while (1) { struct list_head *first; + struct bio *bio; - if (conf->seq_flush - conf->seq_write > 0) { + if (conf->seq_flush != conf->seq_write) { int seq = conf->seq_flush; spin_unlock_irq(&conf->device_lock); bitmap_unplug(mddev->bitmap); @@ -1713,6 +3220,16 @@ static void raid5d (mddev_t *mddev) !list_empty(&conf->delayed_list)) raid5_activate_delayed(conf); + while ((bio = remove_bio_from_retry(conf))) { + int ok; + spin_unlock_irq(&conf->device_lock); + ok = retry_aligned_read(conf, bio); + spin_lock_irq(&conf->device_lock); + if (!ok) + break; + handled++; + } + if (list_empty(&conf->handle_list)) break; @@ -1721,12 +3238,11 @@ static void raid5d (mddev_t *mddev) list_del_init(first); atomic_inc(&sh->count); - if (atomic_read(&sh->count)!= 1) - BUG(); + BUG_ON(atomic_read(&sh->count)!= 1); spin_unlock_irq(&conf->device_lock); handled++; - handle_stripe(sh); + handle_stripe(sh, conf->spare_page); release_stripe(sh); spin_lock_irq(&conf->device_lock); @@ -1772,6 +3288,7 @@ raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) else break; } + md_allow_write(mddev); while (new > conf->max_nr_stripes) { if (grow_one_stripe(conf)) conf->max_nr_stripes++; @@ -1815,24 +3332,83 @@ static int run(mddev_t *mddev) mdk_rdev_t *rdev; struct disk_info *disk; struct list_head *tmp; + int working_disks = 0; - if (mddev->level != 5 && mddev->level != 4) { - printk(KERN_ERR "raid5: %s: raid level not set to 4/5 (%d)\n", + if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) { + printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n", mdname(mddev), mddev->level); 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; if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) goto abort; + if (mddev->level == 6) { + conf->spare_page = alloc_page(GFP_KERNEL); + if (!conf->spare_page) + goto abort; + } spin_lock_init(&conf->device_lock); init_waitqueue_head(&conf->wait_for_stripe); init_waitqueue_head(&conf->wait_for_overlap); @@ -1842,12 +3418,13 @@ static int run(mddev_t *mddev) INIT_LIST_HEAD(&conf->inactive_list); atomic_set(&conf->active_stripes, 0); atomic_set(&conf->preread_active_stripes, 0); + atomic_set(&conf->active_aligned_reads, 0); PRINTK("raid5: run(%s) called.\n", mdname(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; @@ -1859,25 +3436,34 @@ static int run(mddev_t *mddev) printk(KERN_INFO "raid5: device %s operational as raid" " disk %d\n", bdevname(rdev->bdev,b), raid_disk); - conf->working_disks++; + working_disks++; } } - conf->raid_disks = mddev->raid_disks; /* - * 0 for a fully functional array, 1 for a degraded array. + * 0 for a fully functional array, 1 or 2 for a degraded array. */ - mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; + mddev->degraded = conf->raid_disks - working_disks; conf->mddev = mddev; conf->chunk_size = mddev->chunk_size; conf->level = mddev->level; + if (conf->level == 6) + conf->max_degraded = 2; + else + conf->max_degraded = 1; 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); mddev->resync_max_sectors = mddev->size << 1; + if (conf->level == 6 && conf->raid_disks < 4) { + printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n", + mdname(mddev), conf->raid_disks); + goto abort; + } if (!conf->chunk_size || conf->chunk_size % 4) { printk(KERN_ERR "raid5: invalid chunk size %d for %s\n", conf->chunk_size, mdname(mddev)); @@ -1889,14 +3475,14 @@ static int run(mddev_t *mddev) conf->algorithm, mdname(mddev)); goto abort; } - if (mddev->degraded > 1) { + if (mddev->degraded > conf->max_degraded) { printk(KERN_ERR "raid5: not enough operational devices for %s" " (%d/%d failed)\n", - mdname(mddev), conf->failed_disks, conf->raid_disks); + mdname(mddev), mddev->degraded, conf->raid_disks); goto abort; } - if (mddev->degraded == 1 && + if (mddev->degraded > 0 && mddev->recovery_cp != MaxSector) { if (mddev->ok_start_degraded) printk(KERN_WARNING @@ -1945,12 +3531,25 @@ 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"); + } + /* read-ahead size must cover two whole stripes, which is - * 2 * (n-1) * chunksize where 'n' is the number of raid devices + * 2 * (datadisks) * chunksize where 'n' is the number of raid devices */ { - int stripe = (mddev->raid_disks-1) * mddev->chunk_size - / PAGE_SIZE; + int data_disks = conf->previous_raid_disks - conf->max_degraded; + int stripe = data_disks * + (mddev->chunk_size / PAGE_SIZE); if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) mddev->queue->backing_dev_info.ra_pages = 2 * stripe; } @@ -1960,12 +3559,20 @@ static int run(mddev_t *mddev) mddev->queue->unplug_fn = raid5_unplug_device; mddev->queue->issue_flush_fn = raid5_issue_flush; + mddev->queue->backing_dev_info.congested_fn = raid5_congested; + mddev->queue->backing_dev_info.congested_data = mddev; + + mddev->array_size = mddev->size * (conf->previous_raid_disks - + conf->max_degraded); + + blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); - mddev->array_size = mddev->size * (mddev->raid_disks - 1); return 0; abort: if (conf) { print_raid5_conf(conf); + safe_put_page(conf->spare_page); + kfree(conf->disks); kfree(conf->stripe_hashtbl); kfree(conf); } @@ -1986,29 +3593,30 @@ 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; } #if RAID5_DEBUG -static void print_sh (struct stripe_head *sh) +static void print_sh (struct seq_file *seq, struct stripe_head *sh) { int i; - printk("sh %llu, pd_idx %d, state %ld.\n", - (unsigned long long)sh->sector, sh->pd_idx, sh->state); - 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++) { - printk("(cache%d: %p %ld) ", - i, sh->dev[i].page, sh->dev[i].flags); + seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", + (unsigned long long)sh->sector, sh->pd_idx, sh->state); + seq_printf(seq, "sh %llu, count %d.\n", + (unsigned long long)sh->sector, atomic_read(&sh->count)); + seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); + for (i = 0; i < sh->disks; i++) { + seq_printf(seq, "(cache%d: %p %ld) ", + i, sh->dev[i].page, sh->dev[i].flags); } - printk("\n"); + seq_printf(seq, "\n"); } -static void printall (raid5_conf_t *conf) +static void printall (struct seq_file *seq, raid5_conf_t *conf) { struct stripe_head *sh; struct hlist_node *hn; @@ -2019,7 +3627,7 @@ static void printall (raid5_conf_t *conf) hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { if (sh->raid_conf != conf) continue; - print_sh(sh); + print_sh(seq, sh); } } spin_unlock_irq(&conf->device_lock); @@ -2032,16 +3640,15 @@ static void status (struct seq_file *seq, mddev_t *mddev) int i; seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); - seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); + seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); for (i = 0; i < conf->raid_disks; i++) seq_printf (seq, "%s", conf->disks[i].rdev && test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); seq_printf (seq, "]"); #if RAID5_DEBUG -#define D(x) \ - seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x)) - printall(conf); + seq_printf (seq, "\n"); + printall(seq, conf); #endif } @@ -2055,8 +3662,8 @@ static void print_raid5_conf (raid5_conf_t *conf) printk("(conf==NULL)\n"); return; } - printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, - conf->working_disks, conf->failed_disks); + printk(" --- rd:%d wd:%d\n", conf->raid_disks, + conf->raid_disks - conf->mddev->degraded); for (i = 0; i < conf->raid_disks; i++) { char b[BDEVNAME_SIZE]; @@ -2078,11 +3685,11 @@ static int raid5_spare_active(mddev_t *mddev) tmp = conf->disks + i; if (tmp->rdev && !test_bit(Faulty, &tmp->rdev->flags) - && !test_bit(In_sync, &tmp->rdev->flags)) { + && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { + unsigned long flags; + spin_lock_irqsave(&conf->device_lock, flags); mddev->degraded--; - conf->failed_disks--; - conf->working_disks++; - set_bit(In_sync, &tmp->rdev->flags); + spin_unlock_irqrestore(&conf->device_lock, flags); } } print_raid5_conf(conf); @@ -2125,14 +3732,20 @@ static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) int disk; struct disk_info *p; - if (mddev->degraded > 1) + if (mddev->degraded > conf->max_degraded) /* no point adding a device */ return 0; /* - * find the disk ... + * find the disk ... but prefer rdev->saved_raid_disk + * if possible. */ - for (disk=0; disk < mddev->raid_disks; disk++) + if (rdev->saved_raid_disk >= 0 && + conf->disks[rdev->saved_raid_disk].rdev == NULL) + disk = rdev->saved_raid_disk; + else + disk = 0; + for ( ; disk < conf->raid_disks; disk++) if ((p=conf->disks + disk)->rdev == NULL) { clear_bit(In_sync, &rdev->flags); rdev->raid_disk = disk; @@ -2155,8 +3768,10 @@ static int raid5_resize(mddev_t *mddev, sector_t sectors) * any io in the removed space completes, but it hardly seems * worth it. */ + raid5_conf_t *conf = mddev_to_conf(mddev); + sectors &= ~((sector_t)mddev->chunk_size/512 - 1); - mddev->array_size = (sectors * (mddev->raid_disks-1))>>1; + mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1; set_capacity(mddev->gendisk, mddev->array_size << 1); mddev->changed = 1; if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { @@ -2168,16 +3783,166 @@ 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; + unsigned long flags; + + 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); + added_devices++; + rdev->recovery_offset = 0; + sprintf(nm, "rd%d", rdev->raid_disk); + sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); + } else + break; + } + + spin_lock_irqsave(&conf->device_lock, flags); + mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices; + spin_unlock_irqrestore(&conf->device_lock, flags); + mddev->raid_disks = conf->raid_disks; + mddev->reshape_position = 0; + set_bit(MD_CHANGE_DEVS, &mddev->flags); + + 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, (loff_t)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; + + /* read-ahead size must cover two whole stripes, which is + * 2 * (datadisks) * chunksize where 'n' is the number of raid devices + */ + { + int data_disks = conf->previous_raid_disks - conf->max_degraded; + int stripe = data_disks * + (conf->mddev->chunk_size / PAGE_SIZE); + if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) + conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; + } + } +} + 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; wait_event_lock_irq(conf->wait_for_stripe, - atomic_read(&conf->active_stripes) == 0, + atomic_read(&conf->active_stripes) == 0 && + atomic_read(&conf->active_aligned_reads) == 0, conf->device_lock, /* nothing */); spin_unlock_irq(&conf->device_lock); break; @@ -2186,11 +3951,29 @@ 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; } } +static struct mdk_personality raid6_personality = +{ + .name = "raid6", + .level = 6, + .owner = THIS_MODULE, + .make_request = make_request, + .run = run, + .stop = stop, + .status = status, + .error_handler = error, + .hot_add_disk = raid5_add_disk, + .hot_remove_disk= raid5_remove_disk, + .spare_active = raid5_spare_active, + .sync_request = sync_request, + .resize = raid5_resize, + .quiesce = raid5_quiesce, +}; static struct mdk_personality raid5_personality = { .name = "raid5", @@ -2206,6 +3989,10 @@ 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, }; @@ -2229,6 +4016,12 @@ static struct mdk_personality raid4_personality = static int __init raid5_init(void) { + int e; + + e = raid6_select_algo(); + if ( e ) + return e; + register_md_personality(&raid6_personality); register_md_personality(&raid5_personality); register_md_personality(&raid4_personality); return 0; @@ -2236,6 +4029,7 @@ static int __init raid5_init(void) static void raid5_exit(void) { + unregister_md_personality(&raid6_personality); unregister_md_personality(&raid5_personality); unregister_md_personality(&raid4_personality); } @@ -2248,3 +4042,10 @@ MODULE_ALIAS("md-raid5"); MODULE_ALIAS("md-raid4"); MODULE_ALIAS("md-level-5"); MODULE_ALIAS("md-level-4"); +MODULE_ALIAS("md-personality-8"); /* RAID6 */ +MODULE_ALIAS("md-raid6"); +MODULE_ALIAS("md-level-6"); + +/* This used to be two separate modules, they were: */ +MODULE_ALIAS("raid5"); +MODULE_ALIAS("raid6");