diff options
Diffstat (limited to 'drivers/md/raid6main.c')
| -rw-r--r-- | drivers/md/raid6main.c | 2427 |
1 files changed, 0 insertions, 2427 deletions
diff --git a/drivers/md/raid6main.c b/drivers/md/raid6main.c deleted file mode 100644 index e53d2d9..0000000 --- a/drivers/md/raid6main.c +++ /dev/null @@ -1,2427 +0,0 @@ -/* - * raid6main.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-6 management functions. This code is derived from raid5.c. - * Last merge from raid5.c bkcvs version 1.79 (kernel 2.6.1). - * - * 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 - * the Free Software Foundation; either version 2, or (at your option) - * any later version. - * - * You should have received a copy of the GNU General Public License - * (for example /usr/src/linux/COPYING); if not, write to the Free - * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - */ - - -#include <linux/config.h> -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/highmem.h> -#include <linux/bitops.h> -#include <asm/atomic.h> -#include "raid6.h" - -#include <linux/raid/bitmap.h> - -/* - * Stripe cache - */ - -#define NR_STRIPES 256 -#define STRIPE_SIZE PAGE_SIZE -#define STRIPE_SHIFT (PAGE_SHIFT - 9) -#define STRIPE_SECTORS (STRIPE_SIZE>>9) -#define IO_THRESHOLD 1 -#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) -#define HASH_MASK (NR_HASH - 1) - -#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) - -/* bio's attached to a stripe+device for I/O are linked together in bi_sector - * order without overlap. There may be several bio's per stripe+device, and - * a bio could span several devices. - * When walking this list for a particular stripe+device, we must never proceed - * beyond a bio that extends past this device, as the next bio might no longer - * be valid. - * This macro is used to determine the 'next' bio in the list, given the sector - * of the current stripe+device - */ -#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) -/* - * The following can be used to debug the driver - */ -#define RAID6_DEBUG 0 /* Extremely verbose printk */ -#define RAID6_PARANOIA 1 /* Check spinlocks */ -#define RAID6_DUMPSTATE 0 /* Include stripe cache state in /proc/mdstat */ -#if RAID6_PARANOIA && defined(CONFIG_SMP) -# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) -#else -# define CHECK_DEVLOCK() -#endif - -#define PRINTK(x...) ((void)(RAID6_DEBUG && printk(KERN_DEBUG x))) -#if RAID6_DEBUG -#undef inline -#undef __inline__ -#define inline -#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_raid6_conf (raid6_conf_t *conf); - -static void __release_stripe(raid6_conf_t *conf, struct stripe_head *sh) -{ - if (atomic_dec_and_test(&sh->count)) { - 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)) - list_add_tail(&sh->lru, &conf->delayed_list); - else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && - conf->seq_write == sh->bm_seq) - list_add_tail(&sh->lru, &conf->bitmap_list); - else { - clear_bit(STRIPE_BIT_DELAY, &sh->state); - list_add_tail(&sh->lru, &conf->handle_list); - } - md_wakeup_thread(conf->mddev->thread); - } else { - 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); - } - 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)) - wake_up(&conf->wait_for_stripe); - } - } -} -static void release_stripe(struct stripe_head *sh) -{ - raid6_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); -} - -static inline void remove_hash(struct stripe_head *sh) -{ - PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); - - hlist_del_init(&sh->hash); -} - -static inline void insert_hash(raid6_conf_t *conf, struct stripe_head *sh) -{ - struct hlist_head *hp = stripe_hash(conf, sh->sector); - - PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); - - CHECK_DEVLOCK(); - hlist_add_head(&sh->hash, hp); -} - - -/* find an idle stripe, make sure it is unhashed, and return it. */ -static struct stripe_head *get_free_stripe(raid6_conf_t *conf) -{ - struct stripe_head *sh = NULL; - struct list_head *first; - - CHECK_DEVLOCK(); - if (list_empty(&conf->inactive_list)) - goto out; - first = conf->inactive_list.next; - sh = list_entry(first, struct stripe_head, lru); - list_del_init(first); - remove_hash(sh); - atomic_inc(&conf->active_stripes); -out: - return sh; -} - -static void shrink_buffers(struct stripe_head *sh, int num) -{ - struct page *p; - int i; - - for (i=0; i<num ; i++) { - p = sh->dev[i].page; - if (!p) - continue; - sh->dev[i].page = NULL; - put_page(p); - } -} - -static int grow_buffers(struct stripe_head *sh, int num) -{ - int i; - - for (i=0; i<num; i++) { - struct page *page; - - if (!(page = alloc_page(GFP_KERNEL))) { - return 1; - } - sh->dev[i].page = page; - } - return 0; -} - -static void raid6_build_block (struct stripe_head *sh, int i); - -static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx) -{ - raid6_conf_t *conf = sh->raid_conf; - int disks = conf->raid_disks, i; - - 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--; ) { - struct r5dev *dev = &sh->dev[i]; - - if (dev->toread || dev->towrite || dev->written || - test_bit(R5_LOCKED, &dev->flags)) { - PRINTK("sector=%llx i=%d %p %p %p %d\n", - (unsigned long long)sh->sector, i, dev->toread, - dev->towrite, dev->written, - test_bit(R5_LOCKED, &dev->flags)); - BUG(); - } - dev->flags = 0; - raid6_build_block(sh, i); - } - insert_hash(conf, sh); -} - -static struct stripe_head *__find_stripe(raid6_conf_t *conf, sector_t sector) -{ - struct stripe_head *sh; - struct hlist_node *hn; - - 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) - return sh; - PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); - return NULL; -} - -static void unplug_slaves(mddev_t *mddev); - -static struct stripe_head *get_active_stripe(raid6_conf_t *conf, sector_t sector, - int pd_idx, int noblock) -{ - struct stripe_head *sh; - - PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector); - - spin_lock_irq(&conf->device_lock); - - do { - wait_event_lock_irq(conf->wait_for_stripe, - conf->quiesce == 0, - conf->device_lock, /* nothing */); - sh = __find_stripe(conf, sector); - if (!sh) { - if (!conf->inactive_blocked) - sh = get_free_stripe(conf); - if (noblock && sh == NULL) - break; - if (!sh) { - conf->inactive_blocked = 1; - wait_event_lock_irq(conf->wait_for_stripe, - !list_empty(&conf->inactive_list) && - (atomic_read(&conf->active_stripes) - < (conf->max_nr_stripes *3/4) - || !conf->inactive_blocked), - conf->device_lock, - unplug_slaves(conf->mddev); - ); - conf->inactive_blocked = 0; - } else - init_stripe(sh, sector, pd_idx); - } else { - if (atomic_read(&sh->count)) { - BUG_ON(!list_empty(&sh->lru)); - } else { - if (!test_bit(STRIPE_HANDLE, &sh->state)) - atomic_inc(&conf->active_stripes); - BUG_ON(list_empty(&sh->lru)); - list_del_init(&sh->lru); - } - } - } while (sh == NULL); - - if (sh) - atomic_inc(&sh->count); - - spin_unlock_irq(&conf->device_lock); - return sh; -} - -static int grow_one_stripe(raid6_conf_t *conf) -{ - struct stripe_head *sh; - sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); - if (!sh) - return 0; - memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev)); - sh->raid_conf = conf; - spin_lock_init(&sh->lock); - - if (grow_buffers(sh, conf->raid_disks)) { - shrink_buffers(sh, conf->raid_disks); - kmem_cache_free(conf->slab_cache, sh); - return 0; - } - /* we just created an active stripe so... */ - atomic_set(&sh->count, 1); - atomic_inc(&conf->active_stripes); - INIT_LIST_HEAD(&sh->lru); - release_stripe(sh); - return 1; -} - -static int grow_stripes(raid6_conf_t *conf, int num) -{ - kmem_cache_t *sc; - int devs = conf->raid_disks; - - sprintf(conf->cache_name[0], "raid6/%s", mdname(conf->mddev)); - - sc = kmem_cache_create(conf->cache_name[0], - sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), - 0, 0, NULL, NULL); - if (!sc) - return 1; - conf->slab_cache = sc; - while (num--) - if (!grow_one_stripe(conf)) - return 1; - return 0; -} - -static int drop_one_stripe(raid6_conf_t *conf) -{ - struct stripe_head *sh; - spin_lock_irq(&conf->device_lock); - sh = get_free_stripe(conf); - spin_unlock_irq(&conf->device_lock); - if (!sh) - return 0; - BUG_ON(atomic_read(&sh->count)); - shrink_buffers(sh, conf->raid_disks); - kmem_cache_free(conf->slab_cache, sh); - atomic_dec(&conf->active_stripes); - return 1; -} - -static void shrink_stripes(raid6_conf_t *conf) -{ - while (drop_one_stripe(conf)) - ; - - if (conf->slab_cache) - kmem_cache_destroy(conf->slab_cache); - conf->slab_cache = NULL; -} - -static int raid6_end_read_request(struct bio * bi, unsigned int bytes_done, - int error) -{ - struct stripe_head *sh = bi->bi_private; - raid6_conf_t *conf = sh->raid_conf; - int disks = conf->raid_disks, i; - int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); - - if (bi->bi_size) - return 1; - - for (i=0 ; i<disks; i++) - if (bi == &sh->dev[i].req) - break; - - PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n", - (unsigned long long)sh->sector, i, atomic_read(&sh->count), - uptodate); - if (i == disks) { - BUG(); - return 0; - } - - 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 "raid6: read error corrected!!\n"); - 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 { - int retry = 0; - clear_bit(R5_UPTODATE, &sh->dev[i].flags); - atomic_inc(&conf->disks[i].rdev->read_errors); - if (conf->mddev->degraded) - printk(KERN_WARNING "raid6: read error not correctable.\n"); - else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) - /* Oh, no!!! */ - printk(KERN_WARNING "raid6: read error NOT corrected!!\n"); - else if (atomic_read(&conf->disks[i].rdev->read_errors) - > conf->max_nr_stripes) - printk(KERN_WARNING - "raid6: Too many read errors, failing device.\n"); - else - retry = 1; - if (retry) - set_bit(R5_ReadError, &sh->dev[i].flags); - 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); - } - } - 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); - return 0; -} - -static int raid6_end_write_request (struct bio *bi, unsigned int bytes_done, - int error) -{ - struct stripe_head *sh = bi->bi_private; - raid6_conf_t *conf = sh->raid_conf; - int disks = conf->raid_disks, i; - unsigned long flags; - int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); - - if (bi->bi_size) - return 1; - - for (i=0 ; i<disks; i++) - if (bi == &sh->dev[i].req) - break; - - PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", - (unsigned long long)sh->sector, i, atomic_read(&sh->count), - uptodate); - if (i == disks) { - BUG(); - return 0; - } - - spin_lock_irqsave(&conf->device_lock, flags); - if (!uptodate) - md_error(conf->mddev, conf->disks[i].rdev); - - rdev_dec_pending(conf->disks[i].rdev, conf->mddev); - - 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); - return 0; -} - - -static sector_t compute_blocknr(struct stripe_head *sh, int i); - -static void raid6_build_block (struct stripe_head *sh, int i) -{ - struct r5dev *dev = &sh->dev[i]; - int pd_idx = sh->pd_idx; - int qd_idx = raid6_next_disk(pd_idx, sh->raid_conf->raid_disks); - - bio_init(&dev->req); - dev->req.bi_io_vec = &dev->vec; - dev->req.bi_vcnt++; - dev->req.bi_max_vecs++; - dev->vec.bv_page = dev->page; - dev->vec.bv_len = STRIPE_SIZE; - dev->vec.bv_offset = 0; - - dev->req.bi_sector = sh->sector; - dev->req.bi_private = sh; - - dev->flags = 0; - if (i != pd_idx && i != qd_idx) - dev->sector = compute_blocknr(sh, i); -} - -static void error(mddev_t *mddev, mdk_rdev_t *rdev) -{ - char b[BDEVNAME_SIZE]; - raid6_conf_t *conf = (raid6_conf_t *) mddev->private; - PRINTK("raid6: error called\n"); - - if (!test_bit(Faulty, &rdev->flags)) { - mddev->sb_dirty = 1; - if (test_bit(In_sync, &rdev->flags)) { - conf->working_disks--; - mddev->degraded++; - conf->failed_disks++; - clear_bit(In_sync, &rdev->flags); - /* - * if recovery was running, make sure it aborts. - */ - set_bit(MD_RECOVERY_ERR, &mddev->recovery); - } - set_bit(Faulty, &rdev->flags); - printk (KERN_ALERT - "raid6: Disk failure on %s, disabling device." - " Operation continuing on %d devices\n", - bdevname(rdev->bdev,b), conf->working_disks); - } -} - -/* - * Input: a 'big' sector number, - * Output: index of the data and parity disk, and the sector # in them. - */ -static sector_t raid6_compute_sector(sector_t r_sector, unsigned int raid_disks, - unsigned int data_disks, unsigned int * dd_idx, - unsigned int * pd_idx, raid6_conf_t *conf) -{ - long stripe; - unsigned long chunk_number; - unsigned int chunk_offset; - sector_t new_sector; - int sectors_per_chunk = conf->chunk_size >> 9; - - /* First compute the information on this sector */ - - /* - * Compute the chunk number and the sector offset inside the chunk - */ - chunk_offset = sector_div(r_sector, sectors_per_chunk); - chunk_number = r_sector; - if ( r_sector != chunk_number ) { - printk(KERN_CRIT "raid6: ERROR: r_sector = %llu, chunk_number = %lu\n", - (unsigned long long)r_sector, (unsigned long)chunk_number); - BUG(); - } - - /* - * Compute the stripe number - */ - stripe = chunk_number / data_disks; - - /* - * Compute the data disk and parity disk indexes inside the stripe - */ - *dd_idx = chunk_number % data_disks; - - /* - * Select the parity disk based on the user selected algorithm. - */ - - /**** 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); - } - - PRINTK("raid6: chunk_number = %lu, pd_idx = %u, dd_idx = %u\n", - chunk_number, *pd_idx, *dd_idx); - - /* - * Finally, compute the new sector number - */ - new_sector = (sector_t) stripe * sectors_per_chunk + chunk_offset; - return new_sector; -} - - -static sector_t compute_blocknr(struct stripe_head *sh, int i) -{ - raid6_conf_t *conf = sh->raid_conf; - int raid_disks = conf->raid_disks, data_disks = raid_disks - 2; - sector_t new_sector = sh->sector, check; - int sectors_per_chunk = conf->chunk_size >> 9; - sector_t stripe; - int chunk_offset; - int chunk_number, dummy1, dummy2, dd_idx = i; - sector_t r_sector; - int i0 = i; - - chunk_offset = sector_div(new_sector, sectors_per_chunk); - stripe = new_sector; - if ( new_sector != stripe ) { - printk(KERN_CRIT "raid6: ERROR: new_sector = %llu, stripe = %lu\n", - (unsigned long long)new_sector, (unsigned long)stripe); - BUG(); - } - - 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); - } - - PRINTK("raid6: compute_blocknr: pd_idx = %u, i0 = %u, i = %u\n", sh->pd_idx, i0, i); - - chunk_number = stripe * data_disks + i; - r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; - - check = raid6_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); - if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { - printk(KERN_CRIT "raid6: compute_blocknr: map not correct\n"); - return 0; - } - return r_sector; -} - - - -/* - * 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, - sector_t sector) -{ - char *pa = page_address(page); - struct bio_vec *bvl; - int i; - int page_offset; - - if (bio->bi_sector >= sector) - page_offset = (signed)(bio->bi_sector - sector) * 512; - else - page_offset = (signed)(sector - bio->bi_sector) * -512; - bio_for_each_segment(bvl, bio, i) { - int len = bio_iovec_idx(bio,i)->bv_len; - int clen; - int b_offset = 0; - - if (page_offset < 0) { - b_offset = -page_offset; - page_offset += b_offset; - len -= b_offset; - } - - 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) - memcpy(pa+page_offset, ba+b_offset, clen); - else - memcpy(ba+b_offset, pa+page_offset, clen); - __bio_kunmap_atomic(ba, KM_USER0); - } - if (clen < len) /* hit end of page */ - break; - page_offset += len; - } -} - -#define check_xor() do { \ - if (count == MAX_XOR_BLOCKS) { \ - xor_block(count, STRIPE_SIZE, ptr); \ - count = 1; \ - } \ - } while(0) - -/* Compute P and Q syndromes */ -static void compute_parity(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_parity(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_parity(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_parity(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. - * 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) -{ - struct bio **bip; - raid6_conf_t *conf = sh->raid_conf; - int firstwrite=0; - - PRINTK("adding bh b#%llu to stripe s#%llu\n", - (unsigned long long)bi->bi_sector, - (unsigned long long)sh->sector); - - - spin_lock(&sh->lock); - spin_lock_irq(&conf->device_lock); - if (forwrite) { - bip = &sh->dev[dd_idx].towrite; - if (*bip == NULL && sh->dev[dd_idx].written == NULL) - firstwrite = 1; - } else - bip = &sh->dev[dd_idx].toread; - while (*bip && (*bip)->bi_sector < bi->bi_sector) { - if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) - goto overlap; - bip = &(*bip)->bi_next; - } - if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) - goto overlap; - - BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); - if (*bip) - bi->bi_next = *bip; - *bip = bi; - bi->bi_phys_segments ++; - spin_unlock_irq(&conf->device_lock); - spin_unlock(&sh->lock); - - PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n", - (unsigned long long)bi->bi_sector, - (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); - set_bit(STRIPE_BIT_DELAY, &sh->state); - } - - if (forwrite) { - /* check if page is covered */ - sector_t sector = sh->dev[dd_idx].sector; - for (bi=sh->dev[dd_idx].towrite; - sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && - bi && bi->bi_sector <= sector; - bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { - if (bi->bi_sector + (bi->bi_size>>9) >= sector) - sector = bi->bi_sector + (bi->bi_size>>9); - } - if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) - set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); - } - return 1; - - overlap: - set_bit(R5_Overlap, &sh->dev[dd_idx].flags); - spin_unlock_irq(&conf->device_lock); - spin_unlock(&sh->lock); - return 0; -} - - -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); -} -/* - * handle_stripe - do things to a stripe. - * - * We lock the stripe and then examine the state of various bits - * to see what needs to be done. - * Possible results: - * return some read request which now have data - * return some write requests which are safely on disc - * schedule a read on some buffers - * schedule a write of some buffers - * return confirmation of parity correctness - * - * Parity calculations are done inside the stripe lock - * buffers are taken off read_list or write_list, and bh_cache buffers - * get BH_Lock set before the stripe lock is released. - * - */ - -static void handle_stripe(struct stripe_head *sh, struct page *tmp_page) -{ - 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; - - 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); -#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); - } - } - } - 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) -#if 0 - || sh->bh_page[i] != bh->b_page -#endif - ) && - !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_parity(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_parity(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; i<failed;i++) { - dev = &sh->dev[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, 0); - } - 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; - else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) - rw = 0; - else - continue; - - bi = &sh->dev[i].req; - - bi->bi_rw = rw; - if (rw) - bi->bi_end_io = raid6_end_write_request; - else - bi->bi_end_io = raid6_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 == 1) - 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 raid6_activate_delayed(raid6_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(raid6_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); - } -} - -static void unplug_slaves(mddev_t *mddev) -{ - raid6_conf_t *conf = mddev_to_conf(mddev); - int i; - - rcu_read_lock(); - for (i=0; i<mddev->raid_disks; i++) { - mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); - if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { - request_queue_t *r_queue = bdev_get_queue(rdev->bdev); - - atomic_inc(&rdev->nr_pending); - rcu_read_unlock(); - - if (r_queue->unplug_fn) - r_queue->unplug_fn(r_queue); - - rdev_dec_pending(rdev, mddev); - rcu_read_lock(); - } - } - rcu_read_unlock(); -} - -static void raid6_unplug_device(request_queue_t *q) -{ - mddev_t *mddev = q->queuedata; - raid6_conf_t *conf = mddev_to_conf(mddev); - unsigned long flags; - - spin_lock_irqsave(&conf->device_lock, flags); - - if (blk_remove_plug(q)) { - conf->seq_flush++; - raid6_activate_delayed(conf); - } - md_wakeup_thread(mddev->thread); - - spin_unlock_irqrestore(&conf->device_lock, flags); - - unplug_slaves(mddev); -} - -static int raid6_issue_flush(request_queue_t *q, struct gendisk *disk, - sector_t *error_sector) -{ - mddev_t *mddev = q->queuedata; - raid6_conf_t *conf = mddev_to_conf(mddev); - int i, ret = 0; - - rcu_read_lock(); - for (i=0; i<mddev->raid_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 inline void raid6_plug_device(raid6_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) -{ - mddev_t *mddev = q->queuedata; - raid6_conf_t *conf = mddev_to_conf(mddev); - const unsigned int raid_disks = conf->raid_disks; - const unsigned int data_disks = raid_disks - 2; - 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); - - if (unlikely(bio_barrier(bi))) { - bio_endio(bi, bi->bi_size, -EOPNOTSUPP); - return 0; - } - - md_write_start(mddev, bi); - - disk_stat_inc(mddev->gendisk, ios[rw]); - disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); - - logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); - last_sector = bi->bi_sector + (bi->bi_size>>9); - - bi->bi_next = NULL; - bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ - - for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { - DEFINE_WAIT(w); - - new_sector = raid6_compute_sector(logical_sector, - raid_disks, data_disks, &dd_idx, &pd_idx, conf); - - PRINTK("raid6: 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)); - if (sh) { - if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { - /* Add failed due to overlap. Flush everything - * and wait a while - */ - raid6_unplug_device(mddev->queue); - release_stripe(sh); - schedule(); - goto retry; - } - finish_wait(&conf->wait_for_overlap, &w); - raid6_plug_device(conf); - handle_stripe(sh, NULL); - release_stripe(sh); - } else { - /* cannot get stripe for read-ahead, just give-up */ - clear_bit(BIO_UPTODATE, &bi->bi_flags); - finish_wait(&conf->wait_for_overlap, &w); - break; - } - - } - spin_lock_irq(&conf->device_lock); - if (--bi->bi_phys_segments == 0) { - int bytes = bi->bi_size; - - if (rw == WRITE ) - md_write_end(mddev); - bi->bi_size = 0; - bi->bi_end_io(bi, bytes, 0); - } - spin_unlock_irq(&conf->device_lock); - return 0; -} - -/* FIXME go_faster isn't used */ -static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) -{ - raid6_conf_t *conf = (raid6_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 raid_disks = conf->raid_disks; - int data_disks = raid_disks - 2; - 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 (mddev->curr_resync < max_sector) /* aborted */ - bitmap_end_sync(mddev->bitmap, mddev->curr_resync, - &sync_blocks, 1); - else /* completed sync */ - conf->fullsync = 0; - bitmap_close_sync(mddev->bitmap); - - return 0; - } - /* if there are 2 or more failed drives and we are trying - * to resync, then assert that we are finished, because there is - * nothing we can do. - */ - if (mddev->degraded >= 2 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { - sector_t rv = (mddev->size << 1) - sector_nr; - *skipped = 1; - return rv; - } - if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && - !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && - !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { - /* we can skip this block, and probably more */ - sync_blocks /= STRIPE_SECTORS; - *skipped = 1; - 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 = raid6_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); - if (sh == NULL) { - sh = get_active_stripe(conf, sector_nr, pd_idx, 0); - /* make sure we don't swamp the stripe cache if someone else - * is trying to get access - */ - schedule_timeout_uninterruptible(1); - } - /* 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; i<mddev->raid_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, NULL); - release_stripe(sh); - - return STRIPE_SECTORS; -} - -/* - * This is our raid6 kernel thread. - * - * We scan the hash table for stripes which can be handled now. - * During the scan, completed stripes are saved for us by the interrupt - * handler, so that they will not have to wait for our next wakeup. - */ -static void raid6d (mddev_t *mddev) -{ - struct stripe_head *sh; - raid6_conf_t *conf = mddev_to_conf(mddev); - int handled; - - PRINTK("+++ raid6d active\n"); - - md_check_recovery(mddev); - - handled = 0; - spin_lock_irq(&conf->device_lock); - while (1) { - struct list_head *first; - - if (conf->seq_flush - conf->seq_write > 0) { - int seq = conf->seq_flush; - spin_unlock_irq(&conf->device_lock); - bitmap_unplug(mddev->bitmap); - spin_lock_irq(&conf->device_lock); - conf->seq_write = seq; - activate_bit_delay(conf); - } - - if (list_empty(&conf->handle_list) && - atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD && - !blk_queue_plugged(mddev->queue) && - !list_empty(&conf->delayed_list)) - raid6_activate_delayed(conf); - - if (list_empty(&conf->handle_list)) - break; - - first = conf->handle_list.next; - sh = list_entry(first, struct stripe_head, lru); - - list_del_init(first); - atomic_inc(&sh->count); - BUG_ON(atomic_read(&sh->count)!= 1); - spin_unlock_irq(&conf->device_lock); - - handled++; - handle_stripe(sh, conf->spare_page); - release_stripe(sh); - - spin_lock_irq(&conf->device_lock); - } - PRINTK("%d stripes handled\n", handled); - - spin_unlock_irq(&conf->device_lock); - - unplug_slaves(mddev); - - PRINTK("--- raid6d inactive\n"); -} - -static ssize_t -raid6_show_stripe_cache_size(mddev_t *mddev, char *page) -{ - raid6_conf_t *conf = mddev_to_conf(mddev); - if (conf) - return sprintf(page, "%d\n", conf->max_nr_stripes); - else - return 0; -} - -static ssize_t -raid6_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) -{ - raid6_conf_t *conf = mddev_to_conf(mddev); - char *end; - int new; - if (len >= PAGE_SIZE) - return -EINVAL; - if (!conf) - return -ENODEV; - - new = simple_strtoul(page, &end, 10); - if (!*page || (*end && *end != '\n') ) - return -EINVAL; - if (new <= 16 || new > 32768) - return -EINVAL; - while (new < conf->max_nr_stripes) { - if (drop_one_stripe(conf)) - conf->max_nr_stripes--; - else - break; - } - while (new > conf->max_nr_stripes) { - if (grow_one_stripe(conf)) - conf->max_nr_stripes++; - else break; - } - return len; -} - -static struct md_sysfs_entry -raid6_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, - raid6_show_stripe_cache_size, - raid6_store_stripe_cache_size); - -static ssize_t -stripe_cache_active_show(mddev_t *mddev, char *page) -{ - raid6_conf_t *conf = mddev_to_conf(mddev); - if (conf) - return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); - else - return 0; -} - -static struct md_sysfs_entry -raid6_stripecache_active = __ATTR_RO(stripe_cache_active); - -static struct attribute *raid6_attrs[] = { - &raid6_stripecache_size.attr, - &raid6_stripecache_active.attr, - NULL, -}; -static struct attribute_group raid6_attrs_group = { - .name = NULL, - .attrs = raid6_attrs, -}; - -static int run(mddev_t *mddev) -{ - raid6_conf_t *conf; - int raid_disk, memory; - mdk_rdev_t *rdev; - struct disk_info *disk; - struct list_head *tmp; - - if (mddev->level != 6) { - PRINTK("raid6: %s: raid level not set to 6 (%d)\n", mdname(mddev), mddev->level); - return -EIO; - } - - mddev->private = kzalloc(sizeof (raid6_conf_t), GFP_KERNEL); - if ((conf = mddev->private) == NULL) - goto abort; - conf->disks = kzalloc(mddev->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; - - 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); - INIT_LIST_HEAD(&conf->handle_list); - INIT_LIST_HEAD(&conf->delayed_list); - INIT_LIST_HEAD(&conf->bitmap_list); - INIT_LIST_HEAD(&conf->inactive_list); - atomic_set(&conf->active_stripes, 0); - atomic_set(&conf->preread_active_stripes, 0); - - PRINTK("raid6: run(%s) called.\n", mdname(mddev)); - - ITERATE_RDEV(mddev,rdev,tmp) { - raid_disk = rdev->raid_disk; - if (raid_disk >= mddev->raid_disks - || raid_disk < 0) - continue; - disk = conf->disks + raid_disk; - - disk->rdev = rdev; - - if (test_bit(In_sync, &rdev->flags)) { - char b[BDEVNAME_SIZE]; - printk(KERN_INFO "raid6: device %s operational as raid" - " disk %d\n", bdevname(rdev->bdev,b), - raid_disk); - conf->working_disks++; - } - } - - conf->raid_disks = mddev->raid_disks; - - /* - * 0 for a fully functional array, 1 or 2 for a degraded array. - */ - mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; - conf->mddev = mddev; - conf->chunk_size = mddev->chunk_size; - conf->level = mddev->level; - conf->algorithm = mddev->layout; - conf->max_nr_stripes = NR_STRIPES; - - /* 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->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 "raid6: invalid chunk size %d for %s\n", - conf->chunk_size, mdname(mddev)); - goto abort; - } - if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { - printk(KERN_ERR - "raid6: unsupported parity algorithm %d for %s\n", - conf->algorithm, mdname(mddev)); - goto abort; - } - if (mddev->degraded > 2) { - printk(KERN_ERR "raid6: not enough operational devices for %s" - " (%d/%d failed)\n", - mdname(mddev), conf->failed_disks, conf->raid_disks); - goto abort; - } - - if (mddev->degraded > 0 && - mddev->recovery_cp != MaxSector) { - if (mddev->ok_start_degraded) - printk(KERN_WARNING "raid6: starting dirty degraded array:%s" - "- data corruption possible.\n", - mdname(mddev)); - else { - printk(KERN_ERR "raid6: cannot start dirty degraded array" - " for %s\n", mdname(mddev)); - goto abort; - } - } - - { - mddev->thread = md_register_thread(raid6d, mddev, "%s_raid6"); - if (!mddev->thread) { - printk(KERN_ERR - "raid6: couldn't allocate thread for %s\n", - mdname(mddev)); - goto abort; - } - } - - memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + - conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; - if (grow_stripes(conf, conf->max_nr_stripes)) { - printk(KERN_ERR - "raid6: couldn't allocate %dkB for buffers\n", memory); - shrink_stripes(conf); - md_unregister_thread(mddev->thread); - goto abort; - } else - printk(KERN_INFO "raid6: allocated %dkB for %s\n", - memory, mdname(mddev)); - - if (mddev->degraded == 0) - printk(KERN_INFO "raid6: raid level %d set %s active with %d out of %d" - " devices, algorithm %d\n", conf->level, mdname(mddev), - mddev->raid_disks-mddev->degraded, mddev->raid_disks, - conf->algorithm); - else - printk(KERN_ALERT "raid6: raid level %d set %s active with %d" - " out of %d devices, algorithm %d\n", conf->level, - mdname(mddev), mddev->raid_disks - mddev->degraded, - mddev->raid_disks, conf->algorithm); - - print_raid6_conf(conf); - - /* read-ahead size must cover two whole stripes, which is - * 2 * (n-2) * chunksize where 'n' is the number of raid devices - */ - { - int stripe = (mddev->raid_disks-2) * - (mddev->chunk_size / PAGE_SIZE); - if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) - mddev->queue->backing_dev_info.ra_pages = 2 * stripe; - } - - /* Ok, everything is just fine now */ - sysfs_create_group(&mddev->kobj, &raid6_attrs_group); - - mddev->array_size = mddev->size * (mddev->raid_disks - 2); - - mddev->queue->unplug_fn = raid6_unplug_device; - mddev->queue->issue_flush_fn = raid6_issue_flush; - return 0; -abort: - if (conf) { - print_raid6_conf(conf); - safe_put_page(conf->spare_page); - kfree(conf->stripe_hashtbl); - kfree(conf->disks); - kfree(conf); - } - mddev->private = NULL; - printk(KERN_ALERT "raid6: failed to run raid set %s\n", mdname(mddev)); - return -EIO; -} - - - -static int stop (mddev_t *mddev) -{ - raid6_conf_t *conf = (raid6_conf_t *) mddev->private; - - md_unregister_thread(mddev->thread); - mddev->thread = NULL; - shrink_stripes(conf); - kfree(conf->stripe_hashtbl); - blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ - sysfs_remove_group(&mddev->kobj, &raid6_attrs_group); - kfree(conf); - mddev->private = NULL; - return 0; -} - -#if RAID6_DUMPSTATE -static void print_sh (struct seq_file *seq, struct stripe_head *sh) -{ - int i; - - 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->raid_conf->raid_disks; i++) { - seq_printf(seq, "(cache%d: %p %ld) ", - i, sh->dev[i].page, sh->dev[i].flags); - } - seq_printf(seq, "\n"); -} - -static void printall (struct seq_file *seq, raid6_conf_t *conf) -{ - struct stripe_head *sh; - struct hlist_node *hn; - int i; - - spin_lock_irq(&conf->device_lock); - for (i = 0; i < NR_HASH; i++) { - sh = conf->stripe_hashtbl[i]; - hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { - if (sh->raid_conf != conf) - continue; - print_sh(seq, sh); - } - } - spin_unlock_irq(&conf->device_lock); -} -#endif - -static void status (struct seq_file *seq, mddev_t *mddev) -{ - raid6_conf_t *conf = (raid6_conf_t *) mddev->private; - 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); - 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 RAID6_DUMPSTATE - seq_printf (seq, "\n"); - printall(seq, conf); -#endif -} - -static void print_raid6_conf (raid6_conf_t *conf) -{ - int i; - struct disk_info *tmp; - - printk("RAID6 conf printout:\n"); - if (!conf) { - printk("(conf==NULL)\n"); - return; - } - printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, - conf->working_disks, conf->failed_disks); - - for (i = 0; i < conf->raid_disks; i++) { - char b[BDEVNAME_SIZE]; - tmp = conf->disks + i; - if (tmp->rdev) - printk(" disk %d, o:%d, dev:%s\n", - i, !test_bit(Faulty, &tmp->rdev->flags), - bdevname(tmp->rdev->bdev,b)); - } -} - -static int raid6_spare_active(mddev_t *mddev) -{ - int i; - raid6_conf_t *conf = mddev->private; - struct disk_info *tmp; - - for (i = 0; i < conf->raid_disks; i++) { - tmp = conf->disks + i; - if (tmp->rdev - && !test_bit(Faulty, &tmp->rdev->flags) - && !test_bit(In_sync, &tmp->rdev->flags)) { - mddev->degraded--; - conf->failed_disks--; - conf->working_disks++; - set_bit(In_sync, &tmp->rdev->flags); - } - } - print_raid6_conf(conf); - return 0; -} - -static int raid6_remove_disk(mddev_t *mddev, int number) -{ - raid6_conf_t *conf = mddev->private; - int err = 0; - mdk_rdev_t *rdev; - struct disk_info *p = conf->disks + number; - - print_raid6_conf(conf); - rdev = p->rdev; - if (rdev) { - if (test_bit(In_sync, &rdev->flags) || - atomic_read(&rdev->nr_pending)) { - err = -EBUSY; - goto abort; - } - p->rdev = NULL; - synchronize_rcu(); - if (atomic_read(&rdev->nr_pending)) { - /* lost the race, try later */ - err = -EBUSY; - p->rdev = rdev; - } - } - -abort: - - print_raid6_conf(conf); - return err; -} - -static int raid6_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) -{ - raid6_conf_t *conf = mddev->private; - int found = 0; - int disk; - struct disk_info *p; - - if (mddev->degraded > 2) - /* no point adding a device */ - return 0; - /* - * find the disk ... but prefer rdev->saved_raid_disk - * if possible. - */ - if (rdev->saved_raid_disk >= 0 && - conf->disks[rdev->saved_raid_disk].rdev == NULL) - disk = rdev->saved_raid_disk; - else - disk = 0; - for ( ; disk < mddev->raid_disks; disk++) - if ((p=conf->disks + disk)->rdev == NULL) { - clear_bit(In_sync, &rdev->flags); - rdev->raid_disk = disk; - found = 1; - if (rdev->saved_raid_disk != disk) - conf->fullsync = 1; - rcu_assign_pointer(p->rdev, rdev); - break; - } - print_raid6_conf(conf); - return found; -} - -static int raid6_resize(mddev_t *mddev, sector_t sectors) -{ - /* no resync is happening, and there is enough space - * on all devices, so we can resize. - * We need to make sure resync covers any new space. - * If the array is shrinking we should possibly wait until - * any io in the removed space completes, but it hardly seems - * worth it. - */ - sectors &= ~((sector_t)mddev->chunk_size/512 - 1); - mddev->array_size = (sectors * (mddev->raid_disks-2))>>1; - set_capacity(mddev->gendisk, mddev->array_size << 1); - mddev->changed = 1; - if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { - mddev->recovery_cp = mddev->size << 1; - set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); - } - mddev->size = sectors /2; - mddev->resync_max_sectors = sectors; - return 0; -} - -static void raid6_quiesce(mddev_t *mddev, int state) -{ - raid6_conf_t *conf = mddev_to_conf(mddev); - - switch(state) { - 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, - conf->device_lock, /* nothing */); - spin_unlock_irq(&conf->device_lock); - break; - - case 0: /* re-enable writes */ - spin_lock_irq(&conf->device_lock); - conf->quiesce = 0; - wake_up(&conf->wait_for_stripe); - 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 = raid6_add_disk, - .hot_remove_disk= raid6_remove_disk, - .spare_active = raid6_spare_active, - .sync_request = sync_request, - .resize = raid6_resize, - .quiesce = raid6_quiesce, -}; - -static int __init raid6_init(void) -{ - int e; - - e = raid6_select_algo(); - if ( e ) - return e; - - return register_md_personality(&raid6_personality); -} - -static void raid6_exit (void) -{ - unregister_md_personality(&raid6_personality); -} - -module_init(raid6_init); -module_exit(raid6_exit); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("md-personality-8"); /* RAID6 */ -MODULE_ALIAS("md-raid6"); -MODULE_ALIAS("md-level-6"); |