| /* |
| * 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-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 |
| * 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. |
| */ |
| |
| /* |
| * 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 <linux/blkdev.h> |
| #include <linux/raid/md_k.h> |
| #include <linux/kthread.h> |
| #include <linux/async_tx.h> |
| #include <linux/seq_file.h> |
| #include "raid5.h" |
| #include "raid6.h" |
| #include "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 BYPASS_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 RAID5_PARANOIA 1 |
| #if RAID5_PARANOIA && defined(CONFIG_SMP) |
| # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) |
| #else |
| # define CHECK_DEVLOCK() |
| #endif |
| |
| #ifdef DEBUG |
| #define inline |
| #define __inline__ |
| #endif |
| |
| #define printk_rl(args...) ((void) (printk_ratelimit() && printk(args))) |
| |
| #if !RAID6_USE_EMPTY_ZERO_PAGE |
| /* In .bss so it's zeroed */ |
| const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); |
| #endif |
| |
| /* |
| * We maintain a biased count of active stripes in the bottom 16 bits of |
| * bi_phys_segments, and a count of processed stripes in the upper 16 bits |
| */ |
| static inline int raid5_bi_phys_segments(struct bio *bio) |
| { |
| return bio->bi_phys_segments & 0xffff; |
| } |
| |
| static inline int raid5_bi_hw_segments(struct bio *bio) |
| { |
| return (bio->bi_phys_segments >> 16) & 0xffff; |
| } |
| |
| static inline int raid5_dec_bi_phys_segments(struct bio *bio) |
| { |
| --bio->bi_phys_segments; |
| return raid5_bi_phys_segments(bio); |
| } |
| |
| static inline int raid5_dec_bi_hw_segments(struct bio *bio) |
| { |
| unsigned short val = raid5_bi_hw_segments(bio); |
| |
| --val; |
| bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio); |
| return val; |
| } |
| |
| static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt) |
| { |
| bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16); |
| } |
| |
| static inline int raid6_next_disk(int disk, int raid_disks) |
| { |
| disk++; |
| return (disk < raid_disks) ? disk : 0; |
| } |
| |
| static void return_io(struct bio *return_bi) |
| { |
| struct bio *bi = return_bi; |
| while (bi) { |
| |
| return_bi = bi->bi_next; |
| bi->bi_next = NULL; |
| bi->bi_size = 0; |
| bio_endio(bi, 0); |
| bi = return_bi; |
| } |
| } |
| |
| static void print_raid5_conf (raid5_conf_t *conf); |
| |
| static int stripe_operations_active(struct stripe_head *sh) |
| { |
| return sh->check_state || sh->reconstruct_state || |
| test_bit(STRIPE_BIOFILL_RUN, &sh->state) || |
| test_bit(STRIPE_COMPUTE_RUN, &sh->state); |
| } |
| |
| static void __release_stripe(raid5_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); |
| 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); |
| blk_plug_device(conf->mddev->queue); |
| } else { |
| clear_bit(STRIPE_BIT_DELAY, &sh->state); |
| list_add_tail(&sh->lru, &conf->handle_list); |
| } |
| md_wakeup_thread(conf->mddev->thread); |
| } else { |
| BUG_ON(stripe_operations_active(sh)); |
| 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); |
| } |
| atomic_dec(&conf->active_stripes); |
| 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); |
| } |
| } |
| } |
| } |
| 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); |
| } |
| |
| static inline void remove_hash(struct stripe_head *sh) |
| { |
| pr_debug("remove_hash(), stripe %llu\n", |
| (unsigned long long)sh->sector); |
| |
| hlist_del_init(&sh->hash); |
| } |
| |
| static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) |
| { |
| struct hlist_head *hp = stripe_hash(conf, sh->sector); |
| |
| pr_debug("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(raid5_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 raid5_build_block(struct stripe_head *sh, int i); |
| |
| static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks) |
| { |
| raid5_conf_t *conf = sh->raid_conf; |
| int i; |
| |
| BUG_ON(atomic_read(&sh->count) != 0); |
| BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); |
| BUG_ON(stripe_operations_active(sh)); |
| |
| CHECK_DEVLOCK(); |
| pr_debug("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; |
| |
| sh->disks = disks; |
| |
| for (i = sh->disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| |
| if (dev->toread || dev->read || dev->towrite || dev->written || |
| test_bit(R5_LOCKED, &dev->flags)) { |
| printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n", |
| (unsigned long long)sh->sector, i, dev->toread, |
| dev->read, dev->towrite, dev->written, |
| test_bit(R5_LOCKED, &dev->flags)); |
| BUG(); |
| } |
| dev->flags = 0; |
| raid5_build_block(sh, i); |
| } |
| insert_hash(conf, sh); |
| } |
| |
| static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks) |
| { |
| struct stripe_head *sh; |
| struct hlist_node *hn; |
| |
| CHECK_DEVLOCK(); |
| pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); |
| hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) |
| if (sh->sector == sector && sh->disks == disks) |
| return sh; |
| pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); |
| return NULL; |
| } |
| |
| static void unplug_slaves(mddev_t *mddev); |
| static void raid5_unplug_device(struct request_queue *q); |
| |
| 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; |
| |
| pr_debug("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, disks); |
| 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, |
| raid5_unplug_device(conf->mddev->queue) |
| ); |
| conf->inactive_blocked = 0; |
| } else |
| init_stripe(sh, sector, pd_idx, disks); |
| } 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); |
| if (list_empty(&sh->lru) && |
| !test_bit(STRIPE_EXPANDING, &sh->state)) |
| BUG(); |
| list_del_init(&sh->lru); |
| } |
| } |
| } while (sh == NULL); |
| |
| if (sh) |
| atomic_inc(&sh->count); |
| |
| spin_unlock_irq(&conf->device_lock); |
| return sh; |
| } |
| |
| static void |
| raid5_end_read_request(struct bio *bi, int error); |
| static void |
| raid5_end_write_request(struct bio *bi, int error); |
| |
| static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) |
| { |
| raid5_conf_t *conf = sh->raid_conf; |
| int i, disks = sh->disks; |
| |
| might_sleep(); |
| |
| 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 (s->syncing || s->expanding || s->expanded) |
| md_sync_acct(rdev->bdev, STRIPE_SECTORS); |
| |
| set_bit(STRIPE_IO_STARTED, &sh->state); |
| |
| bi->bi_bdev = rdev->bdev; |
| pr_debug("%s: for %llu schedule op %ld on disc %d\n", |
| __func__, (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); |
| pr_debug("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 struct dma_async_tx_descriptor * |
| async_copy_data(int frombio, struct bio *bio, struct page *page, |
| sector_t sector, struct dma_async_tx_descriptor *tx) |
| { |
| struct bio_vec *bvl; |
| struct page *bio_page; |
| 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) { |
| b_offset += bio_iovec_idx(bio, i)->bv_offset; |
| bio_page = bio_iovec_idx(bio, i)->bv_page; |
| if (frombio) |
| tx = async_memcpy(page, bio_page, page_offset, |
| b_offset, clen, |
| ASYNC_TX_DEP_ACK, |
| tx, NULL, NULL); |
| else |
| tx = async_memcpy(bio_page, page, b_offset, |
| page_offset, clen, |
| ASYNC_TX_DEP_ACK, |
| tx, NULL, NULL); |
| } |
| if (clen < len) /* hit end of page */ |
| break; |
| page_offset += len; |
| } |
| |
| return tx; |
| } |
| |
| static void ops_complete_biofill(void *stripe_head_ref) |
| { |
| struct stripe_head *sh = stripe_head_ref; |
| struct bio *return_bi = NULL; |
| raid5_conf_t *conf = sh->raid_conf; |
| int i; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| /* clear completed biofills */ |
| spin_lock_irq(&conf->device_lock); |
| for (i = sh->disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| |
| /* acknowledge completion of a biofill operation */ |
| /* and check if we need to reply to a read request, |
| * new R5_Wantfill requests are held off until |
| * !STRIPE_BIOFILL_RUN |
| */ |
| if (test_and_clear_bit(R5_Wantfill, &dev->flags)) { |
| struct bio *rbi, *rbi2; |
| |
| BUG_ON(!dev->read); |
| rbi = dev->read; |
| dev->read = NULL; |
| while (rbi && rbi->bi_sector < |
| dev->sector + STRIPE_SECTORS) { |
| rbi2 = r5_next_bio(rbi, dev->sector); |
| if (!raid5_dec_bi_phys_segments(rbi)) { |
| rbi->bi_next = return_bi; |
| return_bi = rbi; |
| } |
| rbi = rbi2; |
| } |
| } |
| } |
| spin_unlock_irq(&conf->device_lock); |
| clear_bit(STRIPE_BIOFILL_RUN, &sh->state); |
| |
| return_io(return_bi); |
| |
| set_bit(STRIPE_HANDLE, &sh->state); |
| release_stripe(sh); |
| } |
| |
| static void ops_run_biofill(struct stripe_head *sh) |
| { |
| struct dma_async_tx_descriptor *tx = NULL; |
| raid5_conf_t *conf = sh->raid_conf; |
| int i; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| for (i = sh->disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (test_bit(R5_Wantfill, &dev->flags)) { |
| struct bio *rbi; |
| spin_lock_irq(&conf->device_lock); |
| dev->read = rbi = dev->toread; |
| dev->toread = NULL; |
| spin_unlock_irq(&conf->device_lock); |
| while (rbi && rbi->bi_sector < |
| dev->sector + STRIPE_SECTORS) { |
| tx = async_copy_data(0, rbi, dev->page, |
| dev->sector, tx); |
| rbi = r5_next_bio(rbi, dev->sector); |
| } |
| } |
| } |
| |
| atomic_inc(&sh->count); |
| async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx, |
| ops_complete_biofill, sh); |
| } |
| |
| static void ops_complete_compute5(void *stripe_head_ref) |
| { |
| struct stripe_head *sh = stripe_head_ref; |
| int target = sh->ops.target; |
| struct r5dev *tgt = &sh->dev[target]; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| set_bit(R5_UPTODATE, &tgt->flags); |
| BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
| clear_bit(R5_Wantcompute, &tgt->flags); |
| clear_bit(STRIPE_COMPUTE_RUN, &sh->state); |
| if (sh->check_state == check_state_compute_run) |
| sh->check_state = check_state_compute_result; |
| set_bit(STRIPE_HANDLE, &sh->state); |
| release_stripe(sh); |
| } |
| |
| static struct dma_async_tx_descriptor *ops_run_compute5(struct stripe_head *sh) |
| { |
| /* kernel stack size limits the total number of disks */ |
| int disks = sh->disks; |
| struct page *xor_srcs[disks]; |
| int target = sh->ops.target; |
| struct r5dev *tgt = &sh->dev[target]; |
| struct page *xor_dest = tgt->page; |
| int count = 0; |
| struct dma_async_tx_descriptor *tx; |
| int i; |
| |
| pr_debug("%s: stripe %llu block: %d\n", |
| __func__, (unsigned long long)sh->sector, target); |
| BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
| |
| for (i = disks; i--; ) |
| if (i != target) |
| xor_srcs[count++] = sh->dev[i].page; |
| |
| atomic_inc(&sh->count); |
| |
| if (unlikely(count == 1)) |
| tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, |
| 0, NULL, ops_complete_compute5, sh); |
| else |
| tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, |
| ASYNC_TX_XOR_ZERO_DST, NULL, |
| ops_complete_compute5, sh); |
| |
| return tx; |
| } |
| |
| static void ops_complete_prexor(void *stripe_head_ref) |
| { |
| struct stripe_head *sh = stripe_head_ref; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| } |
| |
| static struct dma_async_tx_descriptor * |
| ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) |
| { |
| /* kernel stack size limits the total number of disks */ |
| int disks = sh->disks; |
| struct page *xor_srcs[disks]; |
| int count = 0, pd_idx = sh->pd_idx, i; |
| |
| /* existing parity data subtracted */ |
| struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| /* Only process blocks that are known to be uptodate */ |
| if (test_bit(R5_Wantdrain, &dev->flags)) |
| xor_srcs[count++] = dev->page; |
| } |
| |
| tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, |
| ASYNC_TX_DEP_ACK | ASYNC_TX_XOR_DROP_DST, tx, |
| ops_complete_prexor, sh); |
| |
| return tx; |
| } |
| |
| static struct dma_async_tx_descriptor * |
| ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) |
| { |
| int disks = sh->disks; |
| int i; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| struct bio *chosen; |
| |
| if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) { |
| struct bio *wbi; |
| |
| spin_lock(&sh->lock); |
| chosen = dev->towrite; |
| dev->towrite = NULL; |
| BUG_ON(dev->written); |
| wbi = dev->written = chosen; |
| spin_unlock(&sh->lock); |
| |
| while (wbi && wbi->bi_sector < |
| dev->sector + STRIPE_SECTORS) { |
| tx = async_copy_data(1, wbi, dev->page, |
| dev->sector, tx); |
| wbi = r5_next_bio(wbi, dev->sector); |
| } |
| } |
| } |
| |
| return tx; |
| } |
| |
| static void ops_complete_postxor(void *stripe_head_ref) |
| { |
| struct stripe_head *sh = stripe_head_ref; |
| int disks = sh->disks, i, pd_idx = sh->pd_idx; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (dev->written || i == pd_idx) |
| set_bit(R5_UPTODATE, &dev->flags); |
| } |
| |
| if (sh->reconstruct_state == reconstruct_state_drain_run) |
| sh->reconstruct_state = reconstruct_state_drain_result; |
| else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) |
| sh->reconstruct_state = reconstruct_state_prexor_drain_result; |
| else { |
| BUG_ON(sh->reconstruct_state != reconstruct_state_run); |
| sh->reconstruct_state = reconstruct_state_result; |
| } |
| |
| set_bit(STRIPE_HANDLE, &sh->state); |
| release_stripe(sh); |
| } |
| |
| static void |
| ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) |
| { |
| /* kernel stack size limits the total number of disks */ |
| int disks = sh->disks; |
| struct page *xor_srcs[disks]; |
| |
| int count = 0, pd_idx = sh->pd_idx, i; |
| struct page *xor_dest; |
| int prexor = 0; |
| unsigned long flags; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| /* check if prexor is active which means only process blocks |
| * that are part of a read-modify-write (written) |
| */ |
| if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) { |
| prexor = 1; |
| xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (dev->written) |
| xor_srcs[count++] = dev->page; |
| } |
| } else { |
| xor_dest = sh->dev[pd_idx].page; |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (i != pd_idx) |
| xor_srcs[count++] = dev->page; |
| } |
| } |
| |
| /* 1/ if we prexor'd then the dest is reused as a source |
| * 2/ if we did not prexor then we are redoing the parity |
| * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST |
| * for the synchronous xor case |
| */ |
| flags = ASYNC_TX_DEP_ACK | ASYNC_TX_ACK | |
| (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); |
| |
| atomic_inc(&sh->count); |
| |
| if (unlikely(count == 1)) { |
| flags &= ~(ASYNC_TX_XOR_DROP_DST | ASYNC_TX_XOR_ZERO_DST); |
| tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, |
| flags, tx, ops_complete_postxor, sh); |
| } else |
| tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, |
| flags, tx, ops_complete_postxor, sh); |
| } |
| |
| static void ops_complete_check(void *stripe_head_ref) |
| { |
| struct stripe_head *sh = stripe_head_ref; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| sh->check_state = check_state_check_result; |
| set_bit(STRIPE_HANDLE, &sh->state); |
| release_stripe(sh); |
| } |
| |
| static void ops_run_check(struct stripe_head *sh) |
| { |
| /* kernel stack size limits the total number of disks */ |
| int disks = sh->disks; |
| struct page *xor_srcs[disks]; |
| struct dma_async_tx_descriptor *tx; |
| |
| int count = 0, pd_idx = sh->pd_idx, i; |
| struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (i != pd_idx) |
| xor_srcs[count++] = dev->page; |
| } |
| |
| tx = async_xor_zero_sum(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, |
| &sh->ops.zero_sum_result, 0, NULL, NULL, NULL); |
| |
| atomic_inc(&sh->count); |
| tx = async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx, |
| ops_complete_check, sh); |
| } |
| |
| static void raid5_run_ops(struct stripe_head *sh, unsigned long ops_request) |
| { |
| int overlap_clear = 0, i, disks = sh->disks; |
| struct dma_async_tx_descriptor *tx = NULL; |
| |
| if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { |
| ops_run_biofill(sh); |
| overlap_clear++; |
| } |
| |
| if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) { |
| tx = ops_run_compute5(sh); |
| /* terminate the chain if postxor is not set to be run */ |
| if (tx && !test_bit(STRIPE_OP_POSTXOR, &ops_request)) |
| async_tx_ack(tx); |
| } |
| |
| if (test_bit(STRIPE_OP_PREXOR, &ops_request)) |
| tx = ops_run_prexor(sh, tx); |
| |
| if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { |
| tx = ops_run_biodrain(sh, tx); |
| overlap_clear++; |
| } |
| |
| if (test_bit(STRIPE_OP_POSTXOR, &ops_request)) |
| ops_run_postxor(sh, tx); |
| |
| if (test_bit(STRIPE_OP_CHECK, &ops_request)) |
| ops_run_check(sh); |
| |
| if (overlap_clear) |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (test_and_clear_bit(R5_Overlap, &dev->flags)) |
| wake_up(&sh->raid_conf->wait_for_overlap); |
| } |
| } |
| |
| static int grow_one_stripe(raid5_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; |
| } |
| sh->disks = conf->raid_disks; |
| /* 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(raid5_conf_t *conf, int num) |
| { |
| struct kmem_cache *sc; |
| int devs = conf->raid_disks; |
| |
| 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); |
| if (!sc) |
| return 1; |
| conf->slab_cache = sc; |
| 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; |
| struct kmem_cache *sc; |
| int i; |
| |
| if (newsize <= conf->pool_size) |
| return 0; /* never bother to shrink */ |
| |
| err = md_allow_write(conf->mddev); |
| if (err) |
| return err; |
| |
| /* 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); |
| if (!sc) |
| return -ENOMEM; |
| |
| for (i = conf->max_nr_stripes; i; i--) { |
| nsh = kmem_cache_alloc(sc, GFP_KERNEL); |
| if (!nsh) |
| break; |
| |
| memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev)); |
| |
| nsh->raid_conf = conf; |
| spin_lock_init(&nsh->lock); |
| |
| list_add(&nsh->lru, &newstripes); |
| } |
| if (i) { |
| /* didn't get enough, give up */ |
| while (!list_empty(&newstripes)) { |
| nsh = list_entry(newstripes.next, struct stripe_head, lru); |
| list_del(&nsh->lru); |
| kmem_cache_free(sc, nsh); |
| } |
| kmem_cache_destroy(sc); |
| return -ENOMEM; |
| } |
| /* Step 2 - Must use GFP_NOIO now. |
| * OK, we have enough stripes, start collecting inactive |
| * stripes and copying them over |
| */ |
| list_for_each_entry(nsh, &newstripes, lru) { |
| spin_lock_irq(&conf->device_lock); |
| wait_event_lock_irq(conf->wait_for_stripe, |
| !list_empty(&conf->inactive_list), |
| conf->device_lock, |
| unplug_slaves(conf->mddev) |
| ); |
| osh = get_free_stripe(conf); |
| spin_unlock_irq(&conf->device_lock); |
| atomic_set(&nsh->count, 1); |
| for(i=0; i<conf->pool_size; i++) |
| nsh->dev[i].page = osh->dev[i].page; |
| for( ; i<newsize; i++) |
| nsh->dev[i].page = NULL; |
| kmem_cache_free(conf->slab_cache, osh); |
| } |
| kmem_cache_destroy(conf->slab_cache); |
| |
| /* Step 3. |
| * At this point, we are holding all the stripes so the array |
| * is completely stalled, so now is a good time to resize |
| * conf->disks. |
| */ |
| ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); |
| if (ndisks) { |
| for (i=0; i<conf->raid_disks; i++) |
| ndisks[i] = conf->disks[i]; |
| kfree(conf->disks); |
| conf->disks = ndisks; |
| } else |
| err = -ENOMEM; |
| |
| /* Step 4, return new stripes to service */ |
| while(!list_empty(&newstripes)) { |
| nsh = list_entry(newstripes.next, struct stripe_head, lru); |
| list_del_init(&nsh->lru); |
| for (i=conf->raid_disks; i < newsize; i++) |
| if (nsh->dev[i].page == NULL) { |
| struct page *p = alloc_page(GFP_NOIO); |
| nsh->dev[i].page = p; |
| if (!p) |
| err = -ENOMEM; |
| } |
| release_stripe(nsh); |
| } |
| /* critical section pass, GFP_NOIO no longer needed */ |
| |
| conf->slab_cache = sc; |
| conf->active_name = 1-conf->active_name; |
| conf->pool_size = newsize; |
| return err; |
| } |
| #endif |
| |
| static int drop_one_stripe(raid5_conf_t *conf) |
| { |
| struct stripe_head *sh; |
| |
| 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->pool_size); |
| kmem_cache_free(conf->slab_cache, sh); |
| atomic_dec(&conf->active_stripes); |
| return 1; |
| } |
| |
| static void shrink_stripes(raid5_conf_t *conf) |
| { |
| while (drop_one_stripe(conf)) |
| ; |
| |
| if (conf->slab_cache) |
| kmem_cache_destroy(conf->slab_cache); |
| conf->slab_cache = NULL; |
| } |
| |
| static void raid5_end_read_request(struct bio * bi, int error) |
| { |
| struct stripe_head *sh = bi->bi_private; |
| raid5_conf_t *conf = sh->raid_conf; |
| int disks = sh->disks, i; |
| int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
| char b[BDEVNAME_SIZE]; |
| mdk_rdev_t *rdev; |
| |
| |
| for (i=0 ; i<disks; i++) |
| if (bi == &sh->dev[i].req) |
| break; |
| |
| pr_debug("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; |
| } |
| |
| if (uptodate) { |
| set_bit(R5_UPTODATE, &sh->dev[i].flags); |
| if (test_bit(R5_ReadError, &sh->dev[i].flags)) { |
| rdev = conf->disks[i].rdev; |
| printk_rl(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(&rdev->read_errors); |
| if (conf->mddev->degraded) |
| printk_rl(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_rl(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:%s: Too many read errors, failing device %s.\n", |
| mdname(conf->mddev), bdn); |
| 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, 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(sh); |
| } |
| |
| static void raid5_end_write_request(struct bio *bi, int error) |
| { |
| struct stripe_head *sh = bi->bi_private; |
| raid5_conf_t *conf = sh->raid_conf; |
| int disks = sh->disks, i; |
| int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
| |
| for (i=0 ; i<disks; i++) |
| if (bi == &sh->dev[i].req) |
| break; |
| |
| pr_debug("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; |
| } |
| |
| 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(sh); |
| } |
| |
| |
| static sector_t compute_blocknr(struct stripe_head *sh, int i); |
| |
| static void raid5_build_block(struct stripe_head *sh, int i) |
| { |
| struct r5dev *dev = &sh->dev[i]; |
| |
| 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; |
| dev->sector = compute_blocknr(sh, i); |
| } |
| |
| static void error(mddev_t *mddev, mdk_rdev_t *rdev) |
| { |
| char b[BDEVNAME_SIZE]; |
| raid5_conf_t *conf = (raid5_conf_t *) mddev->private; |
| pr_debug("raid5: error called\n"); |
| |
| if (!test_bit(Faulty, &rdev->flags)) { |
| 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++; |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| /* |
| * if recovery was running, make sure it aborts. |
| */ |
| set_bit(MD_RECOVERY_INTR, &mddev->recovery); |
| } |
| set_bit(Faulty, &rdev->flags); |
| printk(KERN_ALERT |
| "raid5: Disk failure on %s, disabling device.\n" |
| "raid5: Operation continuing on %d devices.\n", |
| bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded); |
| } |
| } |
| |
| /* |
| * Input: a 'big' sector number, |
| * Output: index of the data and parity disk, and the sector # in them. |
| */ |
| static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks, |
| unsigned int data_disks, unsigned int * dd_idx, |
| unsigned int * pd_idx, raid5_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; |
| BUG_ON(r_sector != chunk_number); |
| |
| /* |
| * 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. |
| */ |
| switch(conf->level) { |
| case 4: |
| *pd_idx = data_disks; |
| break; |
| case 5: |
| switch (conf->algorithm) { |
| case ALGORITHM_LEFT_ASYMMETRIC: |
| *pd_idx = data_disks - stripe % raid_disks; |
| if (*dd_idx >= *pd_idx) |
| (*dd_idx)++; |
| break; |
| case ALGORITHM_RIGHT_ASYMMETRIC: |
| *pd_idx = stripe % raid_disks; |
| if (*dd_idx >= *pd_idx) |
| (*dd_idx)++; |
| break; |
| case ALGORITHM_LEFT_SYMMETRIC: |
| *pd_idx = data_disks - stripe % raid_disks; |
| *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; |
| break; |
| case ALGORITHM_RIGHT_SYMMETRIC: |
| *pd_idx = stripe % raid_disks; |
| *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; |
| break; |
| 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; |
| } |
| |
| /* |
| * 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) |
| { |
| raid5_conf_t *conf = sh->raid_conf; |
| 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; |
| int chunk_offset; |
| 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); |
| |
| 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) |
| i--; |
| break; |
| case ALGORITHM_LEFT_SYMMETRIC: |
| case ALGORITHM_RIGHT_SYMMETRIC: |
| if (i < sh->pd_idx) |
| i += raid_disks; |
| i -= (sh->pd_idx + 1); |
| 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; |
| r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; |
| |
| check = raid5_compute_sector(r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); |
| if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { |
| printk(KERN_ERR "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_blocks(count, STRIPE_SIZE, dest, ptr);\ |
| count = 0; \ |
| } \ |
| } while(0) |
| |
| static void compute_parity6(struct stripe_head *sh, int method) |
| { |
| raid5_conf_t *conf = sh->raid_conf; |
| int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = sh->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); |
| |
| pr_debug("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) |
| { |
| int i, count, disks = sh->disks; |
| void *ptr[MAX_XOR_BLOCKS], *dest, *p; |
| int pd_idx = sh->pd_idx; |
| int qd_idx = raid6_next_disk(pd_idx, disks); |
| |
| pr_debug("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 { |
| dest = page_address(sh->dev[dd_idx].page); |
| if (!nozero) memset(dest, 0, STRIPE_SIZE); |
| count = 0; |
| 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) |
| xor_blocks(count, STRIPE_SIZE, dest, 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) |
| { |
| int i, count, disks = sh->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; } |
| |
| pr_debug("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); |
| } |
| } |
| |
| static void |
| schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s, |
| int rcw, int expand) |
| { |
| int i, pd_idx = sh->pd_idx, disks = sh->disks; |
| |
| if (rcw) { |
| /* if we are not expanding this is a proper write request, and |
| * there will be bios with new data to be drained into the |
| * stripe cache |
| */ |
| if (!expand) { |
| sh->reconstruct_state = reconstruct_state_drain_run; |
| set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); |
| } else |
| sh->reconstruct_state = reconstruct_state_run; |
| |
| set_bit(STRIPE_OP_POSTXOR, &s->ops_request); |
| |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| |
| if (dev->towrite) { |
| set_bit(R5_LOCKED, &dev->flags); |
| set_bit(R5_Wantdrain, &dev->flags); |
| if (!expand) |
| clear_bit(R5_UPTODATE, &dev->flags); |
| s->locked++; |
| } |
| } |
| if (s->locked + 1 == disks) |
| if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) |
| atomic_inc(&sh->raid_conf->pending_full_writes); |
| } else { |
| BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || |
| test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); |
| |
| sh->reconstruct_state = reconstruct_state_prexor_drain_run; |
| set_bit(STRIPE_OP_PREXOR, &s->ops_request); |
| set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); |
| set_bit(STRIPE_OP_POSTXOR, &s->ops_request); |
| |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (i == pd_idx) |
| continue; |
| |
| if (dev->towrite && |
| (test_bit(R5_UPTODATE, &dev->flags) || |
| test_bit(R5_Wantcompute, &dev->flags))) { |
| set_bit(R5_Wantdrain, &dev->flags); |
| set_bit(R5_LOCKED, &dev->flags); |
| clear_bit(R5_UPTODATE, &dev->flags); |
| s->locked++; |
| } |
| } |
| } |
| |
| /* keep the parity disk locked while asynchronous operations |
| * are in flight |
| */ |
| set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); |
| clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); |
| s->locked++; |
| |
| pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n", |
| __func__, (unsigned long long)sh->sector, |
| s->locked, s->ops_request); |
| } |
| |
| /* |
| * 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; |
| raid5_conf_t *conf = sh->raid_conf; |
| int firstwrite=0; |
| |
| pr_debug("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); |
| |
| pr_debug("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) { |
| bitmap_startwrite(conf->mddev->bitmap, sh->sector, |
| STRIPE_SECTORS, 0); |
| sh->bm_seq = conf->seq_flush+1; |
| 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 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; |
| } |
| |
| static void |
| handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh, |
| struct stripe_head_state *s, int disks, |
| struct bio **return_bi) |
| { |
| int i; |
| for (i = disks; i--; ) { |
| struct bio *bi; |
| 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) { |
| s->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 (!raid5_dec_bi_phys_segments(bi)) { |
| 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 (!raid5_dec_bi_phys_segments(bi)) { |
| md_write_end(conf->mddev); |
| bi->bi_next = *return_bi; |
| *return_bi = bi; |
| } |
| bi = bi2; |
| } |
| |
| /* fail any reads if this device is non-operational and |
| * the data has not reached the cache yet. |
| */ |
| if (!test_bit(R5_Wantfill, &sh->dev[i].flags) && |
| (!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) s->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 (!raid5_dec_bi_phys_segments(bi)) { |
| 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 (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) |
| if (atomic_dec_and_test(&conf->pending_full_writes)) |
| md_wakeup_thread(conf->mddev->thread); |
| } |
| |
| /* fetch_block5 - checks the given member device to see if its data needs |
| * to be read or computed to satisfy a request. |
| * |
| * Returns 1 when no more member devices need to be checked, otherwise returns |
| * 0 to tell the loop in handle_stripe_fill5 to continue |
| */ |
| static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s, |
| int disk_idx, int disks) |
| { |
| struct r5dev *dev = &sh->dev[disk_idx]; |
| struct r5dev *failed_dev = &sh->dev[s->failed_num]; |
| |
| /* is the data in this block needed, and can we get it? */ |
| if (!test_bit(R5_LOCKED, &dev->flags) && |
| !test_bit(R5_UPTODATE, &dev->flags) && |
| (dev->toread || |
| (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || |
| s->syncing || s->expanding || |
| (s->failed && |
| (failed_dev->toread || |
| (failed_dev->towrite && |
| !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) { |
| /* We would like to get this block, possibly by computing it, |
| * otherwise read it if the backing disk is insync |
| */ |
| if ((s->uptodate == disks - 1) && |
| (s->failed && disk_idx == s->failed_num)) { |
| set_bit(STRIPE_COMPUTE_RUN, &sh->state); |
| set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); |
| set_bit(R5_Wantcompute, &dev->flags); |
| sh->ops.target = disk_idx; |
| s->req_compute = 1; |
| /* Careful: from this point on 'uptodate' is in the eye |
| * of raid5_run_ops which services 'compute' operations |
| * before writes. R5_Wantcompute flags a block that will |
| * be R5_UPTODATE by the time it is needed for a |
| * subsequent operation. |
| */ |
| s->uptodate++; |
| return 1; /* uptodate + compute == disks */ |
| } else if (test_bit(R5_Insync, &dev->flags)) { |
| set_bit(R5_LOCKED, &dev->flags); |
| set_bit(R5_Wantread, &dev->flags); |
| s->locked++; |
| pr_debug("Reading block %d (sync=%d)\n", disk_idx, |
| s->syncing); |
| } |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * handle_stripe_fill5 - read or compute data to satisfy pending requests. |
| */ |
| static void handle_stripe_fill5(struct stripe_head *sh, |
| struct stripe_head_state *s, int disks) |
| { |
| int i; |
| |
| /* look for blocks to read/compute, skip this if a compute |
| * is already in flight, or if the stripe contents are in the |
| * midst of changing due to a write |
| */ |
| if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && |
| !sh->reconstruct_state) |
| for (i = disks; i--; ) |
| if (fetch_block5(sh, s, i, disks)) |
| break; |
| set_bit(STRIPE_HANDLE, &sh->state); |
| } |
| |
| static void handle_stripe_fill6(struct stripe_head *sh, |
| struct stripe_head_state *s, struct r6_state *r6s, |
| int disks) |
| { |
| int i; |
| for (i = disks; i--; ) { |
| struct r5dev *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)) || |
| s->syncing || s->expanding || |
| (s->failed >= 1 && |
| (sh->dev[r6s->failed_num[0]].toread || |
| s->to_write)) || |
| (s->failed >= 2 && |
| (sh->dev[r6s->failed_num[1]].toread || |
| s->to_write)))) { |
| /* we would like to get this block, possibly |
| * by computing it, but we might not be able to |
| */ |
| if ((s->uptodate == disks - 1) && |
| (s->failed && (i == r6s->failed_num[0] || |
| i == r6s->failed_num[1]))) { |
| pr_debug("Computing stripe %llu block %d\n", |
| (unsigned long long)sh->sector, i); |
| compute_block_1(sh, i, 0); |
| s->uptodate++; |
| } else if ( s->uptodate == disks-2 && s->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); |
| pr_debug("Computing stripe %llu blocks %d,%d\n", |
| (unsigned long long)sh->sector, |
| i, other); |
| compute_block_2(sh, i, other); |
| s->uptodate += 2; |
| } else if (test_bit(R5_Insync, &dev->flags)) { |
| set_bit(R5_LOCKED, &dev->flags); |
| set_bit(R5_Wantread, &dev->flags); |
| s->locked++; |
| pr_debug("Reading block %d (sync=%d)\n", |
| i, s->syncing); |
| } |
| } |
| } |
| set_bit(STRIPE_HANDLE, &sh->state); |
| } |
| |
| |
| /* handle_stripe_clean_event |
| * 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. |
| */ |
| static void handle_stripe_clean_event(raid5_conf_t *conf, |
| struct stripe_head *sh, int disks, struct bio **return_bi) |
| { |
| int i; |
| struct r5dev *dev; |
| |
| 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 */ |
| struct bio *wbi, *wbi2; |
| int bitmap_end = 0; |
| pr_debug("Return write for disc %d\n", 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 (!raid5_dec_bi_phys_segments(wbi)) { |
| 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); |
| } |
| } |
| |
| if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) |
| if (atomic_dec_and_test(&conf->pending_full_writes)) |
| md_wakeup_thread(conf->mddev->thread); |
| } |
| |
| static void handle_stripe_dirtying5(raid5_conf_t *conf, |
| struct stripe_head *sh, struct stripe_head_state *s, int disks) |
| { |
| int rmw = 0, rcw = 0, i; |
| for (i = disks; i--; ) { |
| /* would I have to read this buffer for read_modify_write */ |
| struct r5dev *dev = &sh->dev[i]; |
| if ((dev->towrite || i == sh->pd_idx) && |
| !test_bit(R5_LOCKED, &dev->flags) && |
| !(test_bit(R5_UPTODATE, &dev->flags) || |
| test_bit(R5_Wantcompute, &dev->flags))) { |
| if (test_bit(R5_Insync, &dev->flags)) |
| rmw++; |
| else |
| rmw += 2*disks; /* cannot read it */ |
| } |
| /* 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) && |
| !(test_bit(R5_UPTODATE, &dev->flags) || |
| test_bit(R5_Wantcompute, &dev->flags))) { |
| if (test_bit(R5_Insync, &dev->flags)) rcw++; |
| else |
| rcw += 2*disks; |
| } |
| } |
| pr_debug("for sector %llu, rmw=%d rcw=%d\n", |
| (unsigned long long)sh->sector, rmw, rcw); |
| set_bit(STRIPE_HANDLE, &sh->state); |
| if (rmw < rcw && rmw > 0) |
| /* prefer read-modify-write, but need to get some data */ |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if ((dev->towrite || i == sh->pd_idx) && |
| !test_bit(R5_LOCKED, &dev->flags) && |
| !(test_bit(R5_UPTODATE, &dev->flags) || |
| test_bit(R5_Wantcompute, &dev->flags)) && |
| test_bit(R5_Insync, &dev->flags)) { |
| if ( |
| test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
| pr_debug("Read_old block " |
| "%d for r-m-w\n", i); |
| set_bit(R5_LOCKED, &dev->flags); |
| set_bit(R5_Wantread, &dev->flags); |
| s->locked++; |
| } else { |
| set_bit(STRIPE_DELAYED, &sh->state); |
| set_bit(STRIPE_HANDLE, &sh->state); |
| } |
| } |
| } |
| if (rcw <= rmw && rcw > 0) |
| /* want reconstruct write, but need to get some data */ |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (!test_bit(R5_OVERWRITE, &dev->flags) && |
| i != sh->pd_idx && |
| !test_bit(R5_LOCKED, &dev->flags) && |
| !(test_bit(R5_UPTODATE, &dev->flags) || |
| test_bit(R5_Wantcompute, &dev->flags)) && |
| test_bit(R5_Insync, &dev->flags)) { |
| if ( |
| test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
| pr_debug("Read_old block " |
| "%d for Reconstruct\n", i); |
| set_bit(R5_LOCKED, &dev->flags); |
| set_bit(R5_Wantread, &dev->flags); |
| s->locked++; |
| } else { |
| 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 |
| */ |
| /* since handle_stripe can be called at any time we need to handle the |
| * case where a compute block operation has been submitted and then a |
| * subsequent call wants to start a write request. raid5_run_ops only |
| * handles the case where compute block and postxor are requested |
| * simultaneously. If this is not the case then new writes need to be |
| * held off until the compute completes. |
| */ |
| if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && |
| (s->locked == 0 && (rcw == 0 || rmw == 0) && |
| !test_bit(STRIPE_BIT_DELAY, &sh->state))) |
| schedule_reconstruction5(sh, s, rcw == 0, 0); |
| } |
| |
| static void handle_stripe_dirtying6(raid5_conf_t *conf, |
| struct stripe_head *sh, struct stripe_head_state *s, |
| struct r6_state *r6s, int disks) |
| { |
| int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i; |
| int qd_idx = r6s->qd_idx; |
| for (i = disks; i--; ) { |
| struct r5dev *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 { |
| pr_debug("raid6: must_compute: " |
| "disk %d flags=%#lx\n", i, dev->flags); |
| must_compute++; |
| } |
| } |
| } |
| pr_debug("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--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (!test_bit(R5_OVERWRITE, &dev->flags) |
| && !(s->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)) { |
| pr_debug("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); |
| s->locked++; |
| } else { |
| pr_debug("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 (s->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 (s->failed) { |
| case 0: |
| BUG(); |
| case 1: |
| compute_block_1(sh, r6s->failed_num[0], 0); |
| break; |
| case 2: |
| compute_block_2(sh, r6s->failed_num[0], |
| r6s->failed_num[1]); |
| break; |
| default: /* This request should have been failed? */ |
| BUG(); |
| } |
| } |
| |
| pr_debug("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)) { |
| pr_debug("Writing stripe %llu block %d\n", |
| (unsigned long long)sh->sector, i); |
| s->locked++; |
| set_bit(R5_Wantwrite, &sh->dev[i].flags); |
| } |
| if (s->locked == disks) |
| if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) |
| atomic_inc(&conf->pending_full_writes); |
| /* 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); |
| } |
| } |
| } |
| |
| static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh, |
| struct stripe_head_state *s, int disks) |
| { |
| struct r5dev *dev = NULL; |
| |
| set_bit(STRIPE_HANDLE, &sh->state); |
| |
| switch (sh->check_state) { |
| case check_state_idle: |
| /* start a new check operation if there are no failures */ |
| if (s->failed == 0) { |
| BUG_ON(s->uptodate != disks); |
| sh->check_state = check_state_run; |
| set_bit(STRIPE_OP_CHECK, &s->ops_request); |
| clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags); |
| s->uptodate--; |
| break; |
| } |
| dev = &sh->dev[s->failed_num]; |
| /* fall through */ |
| case check_state_compute_result: |
| sh->check_state = check_state_idle; |
| if (!dev) |
| dev = &sh->dev[sh->pd_idx]; |
| |
| /* check that a write has not made the stripe insync */ |
| if (test_bit(STRIPE_INSYNC, &sh->state)) |
| break; |
| |
| /* either failed parity check, or recovery is happening */ |
| BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); |
| BUG_ON(s->uptodate != disks); |
| |
| set_bit(R5_LOCKED, &dev->flags); |
| s->locked++; |
| set_bit(R5_Wantwrite, &dev->flags); |
| |
| clear_bit(STRIPE_DEGRADED, &sh->state); |
| set_bit(STRIPE_INSYNC, &sh->state); |
| break; |
| case check_state_run: |
| break; /* we will be called again upon completion */ |
| case check_state_check_result: |
| sh->check_state = check_state_idle; |
| |
| /* if a failure occurred during the check operation, leave |
| * STRIPE_INSYNC not set and let the stripe be handled again |
| */ |
| if (s->failed) |
| break; |
| |
| /* handle a successful check operation, if parity is correct |
| * we are done. Otherwise update the mismatch count and repair |
| * parity if !MD_RECOVERY_CHECK |
| */ |
| if (sh->ops.zero_sum_result == 0) |
| /* parity is correct (on disc, |
| * not in buffer any more) |
| */ |
| set_bit(STRIPE_INSYNC, &sh->state); |
| else { |
| conf->mddev->resync_mismatches += STRIPE_SECTORS; |
| if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) |
| /* don't try to repair!! */ |
| set_bit(STRIPE_INSYNC, &sh->state); |
| else { |
| sh->check_state = check_state_compute_run; |
| set_bit(STRIPE_COMPUTE_RUN, &sh->state); |
| set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); |
| set_bit(R5_Wantcompute, |
| &sh->dev[sh->pd_idx].flags); |
| sh->ops.target = sh->pd_idx; |
| s->uptodate++; |
| } |
| } |
| break; |
| case check_state_compute_run: |
| break; |
| default: |
| printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", |
| __func__, sh->check_state, |
| (unsigned long long) sh->sector); |
| BUG(); |
| } |
| } |
| |
| |
| static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh, |
| struct stripe_head_state *s, |
| struct r6_state *r6s, struct page *tmp_page, |
| int disks) |
| { |
| int update_p = 0, update_q = 0; |
| struct r5dev *dev; |
| int pd_idx = sh->pd_idx; |
| int qd_idx = r6s->qd_idx; |
| |
| set_bit(STRIPE_HANDLE, &sh->state); |
| |
| BUG_ON(s->failed > 2); |
| BUG_ON(s->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 (s->failed == r6s->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 (!r6s->q_failed && s->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 (s->failed == 2) { |
| dev = &sh->dev[r6s->failed_num[1]]; |
| s->locked++; |
| set_bit(R5_LOCKED, &dev->flags); |
| set_bit(R5_Wantwrite, &dev->flags); |
| } |
| if (s->failed >= 1) { |
| dev = &sh->dev[r6s->failed_num[0]]; |
| s->locked++; |
| set_bit(R5_LOCKED, &dev->flags); |
| set_bit(R5_Wantwrite, &dev->flags); |
| } |
| |
| if (update_p) { |
| dev = &sh->dev[pd_idx]; |
| s->locked++; |
| set_bit(R5_LOCKED, &dev->flags); |
| set_bit(R5_Wantwrite, &dev->flags); |
| } |
| if (update_q) { |
| dev = &sh->dev[qd_idx]; |
| s->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); |
| } |
| } |
| |
| static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh, |
| struct r6_state *r6s) |
| { |
| int i; |
| |
| /* We have read all the blocks in this stripe and now we need to |
| * copy some of them into a target stripe for expand. |
| */ |
| struct dma_async_tx_descriptor *tx = NULL; |
| clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); |
| for (i = 0; i < sh->disks; i++) |
| if (i != sh->pd_idx && (!r6s || i != r6s->qd_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 - |
| conf->max_degraded, &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; |
| } |
| |
| /* place all the copies on one channel */ |
| tx = async_memcpy(sh2->dev[dd_idx].page, |
| sh->dev[i].page, 0, 0, STRIPE_SIZE, |
| ASYNC_TX_DEP_ACK, tx, NULL, NULL); |
| |
| set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); |
| set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); |
| for (j = 0; j < conf->raid_disks; j++) |
| if (j != sh2->pd_idx && |
| (!r6s || j != raid6_next_disk(sh2->pd_idx, |
| sh2->disks)) && |
| !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); |
| |
| } |
| /* done submitting copies, wait for them to complete */ |
| if (tx) { |
| async_tx_ack(tx); |
| dma_wait_for_async_tx(tx); |
| } |
| } |
| |
| |
| /* |
| * 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 |
| * |
| * buffers are taken off read_list or write_list, and bh_cache buffers |
| * get BH_Lock set before the stripe lock is released. |
| * |
| */ |
| |
| static bool handle_stripe5(struct stripe_head *sh) |
| { |
| raid5_conf_t *conf = sh->raid_conf; |
| int disks = sh->disks, i; |
| struct bio *return_bi = NULL; |
| struct stripe_head_state s; |
| struct r5dev *dev; |
| mdk_rdev_t *blocked_rdev = NULL; |
| int prexor; |
| |
| memset(&s, 0, sizeof(s)); |
| pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d " |
| "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state, |
| atomic_read(&sh->count), sh->pd_idx, sh->check_state, |
| sh->reconstruct_state); |
| |
| spin_lock(&sh->lock); |
| clear_bit(STRIPE_HANDLE, &sh->state); |
| clear_bit(STRIPE_DELAYED, &sh->state); |
| |
| s.syncing = test_bit(STRIPE_SYNCING, &sh->state); |
| s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); |
| s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); |
| |
| /* Now to look around and see what can be done */ |
| rcu_read_lock(); |
| for (i=disks; i--; ) { |
| mdk_rdev_t *rdev; |
| struct r5dev *dev = &sh->dev[i]; |
| clear_bit(R5_Insync, &dev->flags); |
| |
| pr_debug("check %d: state 0x%lx toread %p read %p write %p " |
| "written %p\n", i, dev->flags, dev->toread, dev->read, |
| dev->towrite, dev->written); |
| |
| /* maybe we can request a biofill operation |
| * |
| * new wantfill requests are only permitted while |
| * ops_complete_biofill is guaranteed to be inactive |
| */ |
| if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && |
| !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) |
| set_bit(R5_Wantfill, &dev->flags); |
| |
| /* now count some things */ |
| if (test_bit(R5_LOCKED, &dev->flags)) s.locked++; |
| if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++; |
| if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++; |
| |
| if (test_bit(R5_Wantfill, &dev->flags)) |
| s.to_fill++; |
| else if (dev->toread) |
| s.to_read++; |
| if (dev->towrite) { |
| s.to_write++; |
| if (!test_bit(R5_OVERWRITE, &dev->flags)) |
| s.non_overwrite++; |
| } |
| if (dev->written) |
| s.written++; |
| rdev = rcu_dereference(conf->disks[i].rdev); |
| if (blocked_rdev == NULL && |
| rdev && unlikely(test_bit(Blocked, &rdev->flags))) { |
| blocked_rdev = rdev; |
| atomic_inc(&rdev->nr_pending); |
| } |
| 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)) { |
| s.failed++; |
| s.failed_num = i; |
| } else |
| set_bit(R5_Insync, &dev->flags); |
| } |
| rcu_read_unlock(); |
| |
| if (unlikely(blocked_rdev)) { |
| if (s.syncing || s.expanding || s.expanded || |
| s.to_write || s.written) { |
| set_bit(STRIPE_HANDLE, &sh->state); |
| goto unlock; |
| } |
| /* There is nothing for the blocked_rdev to block */ |
| rdev_dec_pending(blocked_rdev, conf->mddev); |
| blocked_rdev = NULL; |
| } |
| |
| if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { |
| set_bit(STRIPE_OP_BIOFILL, &s.ops_request); |
| set_bit(STRIPE_BIOFILL_RUN, &sh->state); |
| } |
| |
| pr_debug("locked=%d uptodate=%d to_read=%d" |
| " to_write=%d failed=%d failed_num=%d\n", |
| s.locked, s.uptodate, s.to_read, s.to_write, |
| s.failed, s.failed_num); |
| /* check if the array has lost two devices and, if so, some requests might |
| * need to be failed |
| */ |
| if (s.failed > 1 && s.to_read+s.to_write+s.written) |
| handle_failed_stripe(conf, sh, &s, disks, &return_bi); |
| if (s.failed > 1 && s.syncing) { |
| md_done_sync(conf->mddev, STRIPE_SECTORS,0); |
| clear_bit(STRIPE_SYNCING, &sh->state); |
| s.syncing = 0; |
| } |
| |
| /* might be able to return some write requests if the parity block |
| * is safe, or on a failed drive |
| */ |
| dev = &sh->dev[sh->pd_idx]; |
| if ( s.written && |
| ((test_bit(R5_Insync, &dev->flags) && |
| !test_bit(R5_LOCKED, &dev->flags) && |
| test_bit(R5_UPTODATE, &dev->flags)) || |
| (s.failed == 1 && s.failed_num == sh->pd_idx))) |
| handle_stripe_clean_event(conf, sh, disks, &return_bi); |
| |
| /* 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 (s.to_read || s.non_overwrite || |
| (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding) |
| handle_stripe_fill5(sh, &s, disks); |
| |
| /* Now we check to see if any write operations have recently |
| * completed |
| */ |
| prexor = 0; |
| if (sh->reconstruct_state == reconstruct_state_prexor_drain_result) |
| prexor = 1; |
| if (sh->reconstruct_state == reconstruct_state_drain_result || |
| sh->reconstruct_state == reconstruct_state_prexor_drain_result) { |
| sh->reconstruct_state = reconstruct_state_idle; |
| |
| /* All the 'written' buffers and the parity block are ready to |
| * be written back to disk |
| */ |
| BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags)); |
| for (i = disks; i--; ) { |
| dev = &sh->dev[i]; |
| if (test_bit(R5_LOCKED, &dev->flags) && |
| (i == sh->pd_idx || dev->written)) { |
| pr_debug("Writing block %d\n", i); |
| set_bit(R5_Wantwrite, &dev->flags); |
| if (prexor) |
| continue; |
| if (!test_bit(R5_Insync, &dev->flags) || |
| (i == sh->pd_idx && s.failed == 0)) |
| 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); |
| } |
| } |
| |
| /* Now to consider new write requests and what else, if anything |
| * should be read. We do not handle new writes when: |
| * 1/ A 'write' operation (copy+xor) is already in flight. |
| * 2/ A 'check' operation is in flight, as it may clobber the parity |
| * block. |
| */ |
| if (s.to_write && !sh->reconstruct_state && !sh->check_state) |
| handle_stripe_dirtying5(conf, sh, &s, disks); |
| |
| /* 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. The parity check is held off while parity |
| * dependent operations are in flight. |
| */ |
| if (sh->check_state || |
| (s.syncing && s.locked == 0 && |
| !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && |
| !test_bit(STRIPE_INSYNC, &sh->state))) |
| handle_parity_checks5(conf, sh, &s, disks); |
| |
| if (s.syncing && s.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 drive is just a ReadError, then we might need to progress |
| * the repair/check process |
| */ |
| if (s.failed == 1 && !conf->mddev->ro && |
| test_bit(R5_ReadError, &sh->dev[s.failed_num].flags) |
| && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags) |
| && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags) |
| ) { |
| dev = &sh->dev[s.failed_num]; |
| 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); |
| s.locked++; |
| } else { |
| /* let's read it back */ |
| set_bit(R5_Wantread, &dev->flags); |
| set_bit(R5_LOCKED, &dev->flags); |
| s.locked++; |
| } |
| } |
| |
| /* Finish reconstruct operations initiated by the expansion process */ |
| if (sh->reconstruct_state == reconstruct_state_result) { |
| sh->reconstruct_state = reconstruct_state_idle; |
| clear_bit(STRIPE_EXPANDING, &sh->state); |
| for (i = conf->raid_disks; i--; ) { |
| set_bit(R5_Wantwrite, &sh->dev[i].flags); |
| set_bit(R5_LOCKED, &sh->dev[i].flags); |
| s.locked++; |
| } |
| } |
| |
| if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && |
| !sh->reconstruct_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); |
| schedule_reconstruction5(sh, &s, 1, 1); |
| } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { |
| 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 (s.expanding && s.locked == 0 && |
| !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) |
| handle_stripe_expansion(conf, sh, NULL); |
| |
| unlock: |
| spin_unlock(&sh->lock); |
| |
| /* wait for this device to become unblocked */ |
| if (unlikely(blocked_rdev)) |
| md_wait_for_blocked_rdev(blocked_rdev, conf->mddev); |
| |
| if (s.ops_request) |
| raid5_run_ops(sh, s.ops_request); |
| |
| ops_run_io(sh, &s); |
| |
| return_io(return_bi); |
| |
| return blocked_rdev == NULL; |
| } |
| |
| static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page) |
| { |
| raid5_conf_t *conf = sh->raid_conf; |
| int disks = sh->disks; |
| struct bio *return_bi = NULL; |
| int i, pd_idx = sh->pd_idx; |
| struct stripe_head_state s; |
| struct r6_state r6s; |
| struct r5dev *dev, *pdev, *qdev; |
| mdk_rdev_t *blocked_rdev = NULL; |
| |
| r6s.qd_idx = raid6_next_disk(pd_idx, disks); |
| pr_debug("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, r6s.qd_idx); |
| memset(&s, 0, sizeof(s)); |
| |
| spin_lock(&sh->lock); |
| clear_bit(STRIPE_HANDLE, &sh->state); |
| clear_bit(STRIPE_DELAYED, &sh->state); |
| |
| s.syncing = test_bit(STRIPE_SYNCING, &sh->state); |
| s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); |
| s.expanded = test_bit(STRIPE_EXPAND_READY, &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); |
| |
| pr_debug("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; |
| pr_debug("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 (!raid5_dec_bi_phys_segments(rbi)) { |
| 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)) s.locked++; |
| if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++; |
| |
| |
| if (dev->toread) |
| s.to_read++; |
| if (dev->towrite) { |
| s.to_write++; |
| if (!test_bit(R5_OVERWRITE, &dev->flags)) |
| s.non_overwrite++; |
| } |
| if (dev->written) |
| s.written++; |
| rdev = rcu_dereference(conf->disks[i].rdev); |
| if (blocked_rdev == NULL && |
| rdev && unlikely(test_bit(Blocked, &rdev->flags))) { |
| blocked_rdev = rdev; |
| atomic_inc(&rdev->nr_pending); |
| } |
| 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 (s.failed < 2) |
| r6s.failed_num[s.failed] = i; |
| s.failed++; |
| } else |
| set_bit(R5_Insync, &dev->flags); |
| } |
| rcu_read_unlock(); |
| |
| if (unlikely(blocked_rdev)) { |
| if (s.syncing || s.expanding || s.expanded || |
| s.to_write || s.written) { |
| set_bit(STRIPE_HANDLE, &sh->state); |
| goto unlock; |
| } |
| /* There is nothing for the blocked_rdev to block */ |
| rdev_dec_pending(blocked_rdev, conf->mddev); |
| blocked_rdev = NULL; |
| } |
| |
| pr_debug("locked=%d uptodate=%d to_read=%d" |
| " to_write=%d failed=%d failed_num=%d,%d\n", |
| s.locked, s.uptodate, s.to_read, s.to_write, s.failed, |
| r6s.failed_num[0], r6s.failed_num[1]); |
| /* check if the array has lost >2 devices and, if so, some requests |
| * might need to be failed |
| */ |
| if (s.failed > 2 && s.to_read+s.to_write+s.written) |
| handle_failed_stripe(conf, sh, &s, disks, &return_bi); |
| if (s.failed > 2 && s.syncing) { |
| md_done_sync(conf->mddev, STRIPE_SECTORS,0); |
| clear_bit(STRIPE_SYNCING, &sh->state); |
| s.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]; |
| r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx) |
| || (s.failed >= 2 && r6s.failed_num[1] == pd_idx); |
| qdev = &sh->dev[r6s.qd_idx]; |
| r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == r6s.qd_idx) |
| || (s.failed >= 2 && r6s.failed_num[1] == r6s.qd_idx); |
| |
| if ( s.written && |
| ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags) |
| && !test_bit(R5_LOCKED, &pdev->flags) |
| && test_bit(R5_UPTODATE, &pdev->flags)))) && |
| ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags) |
| && !test_bit(R5_LOCKED, &qdev->flags) |
| && test_bit(R5_UPTODATE, &qdev->flags))))) |
| handle_stripe_clean_event(conf, sh, disks, &return_bi); |
| |
| /* 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 (s.to_read || s.non_overwrite || (s.to_write && s.failed) || |
| (s.syncing && (s.uptodate < disks)) || s.expanding) |
| handle_stripe_fill6(sh, &s, &r6s, disks); |
| |
| /* now to consider writing and what else, if anything should be read */ |
| if (s.to_write) |
| handle_stripe_dirtying6(conf, sh, &s, &r6s, disks); |
| |
| /* 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 (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) |
| handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks); |
| |
| if (s.syncing && s.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 (s.failed <= 2 && !conf->mddev->ro) |
| for (i = 0; i < s.failed; i++) { |
| dev = &sh->dev[r6s.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); |
| } |
| } |
| } |
| |
| if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) { |
| /* Need to write out all blocks after computing P&Q */ |
| sh->disks = conf->raid_disks; |
| sh->pd_idx = stripe_to_pdidx(sh->sector, conf, |
| conf->raid_disks); |
| compute_parity6(sh, RECONSTRUCT_WRITE); |
| for (i = conf->raid_disks ; i-- ; ) { |
| set_bit(R5_LOCKED, &sh->dev[i].flags); |
| s.locked++; |
| set_bit(R5_Wantwrite, &sh->dev[i].flags); |
| } |
| clear_bit(STRIPE_EXPANDING, &sh->state); |
| } else if (s.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 (s.expanding && s.locked == 0 && |
| !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) |
| handle_stripe_expansion(conf, sh, &r6s); |
| |
| unlock: |
| spin_unlock(&sh->lock); |
| |
| /* wait for this device to become unblocked */ |
| if (unlikely(blocked_rdev)) |
| md_wait_for_blocked_rdev(blocked_rdev, conf->mddev); |
| |
| ops_run_io(sh, &s); |
| |
| return_io(return_bi); |
| |
| return blocked_rdev == NULL; |
| } |
| |
| /* returns true if the stripe was handled */ |
| static bool handle_stripe(struct stripe_head *sh, struct page *tmp_page) |
| { |
| if (sh->raid_conf->level == 6) |
| return handle_stripe6(sh, tmp_page); |
| else |
| return 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->hold_list); |
| } |
| } else |
| blk_plug_device(conf->mddev->queue); |
| } |
| |
| 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); |
| } |
| } |
| |
| static void unplug_slaves(mddev_t *mddev) |
| { |
| raid5_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)) { |
| struct request_queue *r_queue = bdev_get_queue(rdev->bdev); |
| |
| atomic_inc(&rdev->nr_pending); |
| rcu_read_unlock(); |
| |
| blk_unplug(r_queue); |
| |
| rdev_dec_pending(rdev, mddev); |
| rcu_read_lock(); |
| } |
| } |
| rcu_read_unlock(); |
| } |
| |
| static void raid5_unplug_device(struct request_queue *q) |
| { |
| mddev_t *mddev = q->queuedata; |
| raid5_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++; |
| raid5_activate_delayed(conf); |
| } |
| md_wakeup_thread(mddev->thread); |
| |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| |
| unplug_slaves(mddev); |
| } |
| |
| 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(struct request_queue *q, |
| struct bvec_merge_data *bvm, |
| struct bio_vec *biovec) |
| { |
| mddev_t *mddev = q->queuedata; |
| sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); |
| int max; |
| unsigned int chunk_sectors = mddev->chunk_size >> 9; |
| unsigned int bio_sectors = bvm->bi_size >> 9; |
| |
| if ((bvm->bi_rw & 1) == 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; |
| /* |
| * this sets the active strip count to 1 and the processed |
| * strip count to zero (upper 8 bits) |
| */ |
| bi->bi_phys_segments = 1; /* biased count of active 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 void raid5_align_endio(struct bio *bi, 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; |
| |
| 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, 0); |
| if (atomic_dec_and_test(&conf->active_aligned_reads)) |
| wake_up(&conf->wait_for_stripe); |
| return; |
| } |
| |
| |
| pr_debug("raid5_align_endio : io error...handing IO for a retry\n"); |
| |
| add_bio_to_retry(raid_bi, conf); |
| } |
| |
| static int bio_fits_rdev(struct bio *bi) |
| { |
| struct request_queue *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) |
| return 0; |
| |
| 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 chunk_aligned_read(struct request_queue *q, struct bio * raid_bio) |
| { |
| 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 - conf->max_degraded; |
| unsigned int dd_idx, pd_idx; |
| struct bio* align_bi; |
| mdk_rdev_t *rdev; |
| |
| if (!in_chunk_boundary(mddev, raid_bio)) { |
| pr_debug("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); |
| |
| 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; |
| } |
| } |
| |
| /* __get_priority_stripe - get the next stripe to process |
| * |
| * Full stripe writes are allowed to pass preread active stripes up until |
| * the bypass_threshold is exceeded. In general the bypass_count |
| * increments when the handle_list is handled before the hold_list; however, it |
| * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a |
| * stripe with in flight i/o. The bypass_count will be reset when the |
| * head of the hold_list has changed, i.e. the head was promoted to the |
| * handle_list. |
| */ |
| static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf) |
| { |
| struct stripe_head *sh; |
| |
| pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n", |
| __func__, |
| list_empty(&conf->handle_list) ? "empty" : "busy", |
| list_empty(&conf->hold_list) ? "empty" : "busy", |
| atomic_read(&conf->pending_full_writes), conf->bypass_count); |
| |
| if (!list_empty(&conf->handle_list)) { |
| sh = list_entry(conf->handle_list.next, typeof(*sh), lru); |
| |
| if (list_empty(&conf->hold_list)) |
| conf->bypass_count = 0; |
| else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) { |
| if (conf->hold_list.next == conf->last_hold) |
| conf->bypass_count++; |
| else { |
| conf->last_hold = conf->hold_list.next; |
| conf->bypass_count -= conf->bypass_threshold; |
| if (conf->bypass_count < 0) |
| conf->bypass_count = 0; |
| } |
| } |
| } else if (!list_empty(&conf->hold_list) && |
| ((conf->bypass_threshold && |
| conf->bypass_count > conf->bypass_threshold) || |
| atomic_read(&conf->pending_full_writes) == 0)) { |
| sh = list_entry(conf->hold_list.next, |
| typeof(*sh), lru); |
| conf->bypass_count -= conf->bypass_threshold; |
| if (conf->bypass_count < 0) |
| conf->bypass_count = 0; |
| } else |
| return NULL; |
| |
| list_del_init(&sh->lru); |
| atomic_inc(&sh->count); |
| BUG_ON(atomic_read(&sh->count) != 1); |
| return sh; |
| } |
| |
| static int make_request(struct request_queue *q, struct bio * bi) |
| { |
| mddev_t *mddev = q->queuedata; |
| raid5_conf_t *conf = mddev_to_conf(mddev); |
| 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 cpu, remaining; |
| |
| if (unlikely(bio_barrier(bi))) { |
| bio_endio(bi, -EOPNOTSUPP); |
| return 0; |
| } |
| |
| md_write_start(mddev, bi); |
| |
| cpu = part_stat_lock(); |
| part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]); |
| part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], |
| bio_sectors(bi)); |
| part_stat_unlock(); |
| |
| 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; |
| bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ |
| |
| for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { |
| DEFINE_WAIT(w); |
| 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); |
| pr_debug("raid5: make_request, sector %llu logical %llu\n", |
| (unsigned long long)new_sector, |
| (unsigned long long)logical_sector); |
| |
| sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK)); |
| if (sh) { |
| 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); |
| release_stripe(sh); |
| schedule(); |
| goto retry; |
| } |
| finish_wait(&conf->wait_for_overlap, &w); |
| set_bit(STRIPE_HANDLE, &sh->state); |
| clear_bit(STRIPE_DELAYED, &sh->state); |
| 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); |
| remaining = raid5_dec_bi_phys_segments(bi); |
| spin_unlock_irq(&conf->device_lock); |
| if (remaining == 0) { |
| |
| if ( rw == WRITE ) |
| md_write_end(mddev); |
| |
| bio_endio(bi, 0); |
| } |
| 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 = conf->previous_raid_disks; |
| int data_disks = raid_disks - conf->max_degraded; |
| int new_data_disks = conf->raid_disks - conf->max_degraded; |
| 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, new_data_disks); |
| *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*(new_data_disks); |
| sector_div(writepos, new_data_disks); |
| safepos = conf->expand_lo; |
| sector_div(safepos, data_disks); |
| gap = conf->expand_progress - conf->expand_lo; |
| |
| if (writepos >= safepos || |
| gap > (new_data_disks)*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; |
| if (conf->level == 6 && |
| j == raid6_next_disk(sh->pd_idx, sh->disks)) |
| continue; |
| s = compute_blocknr(sh, j); |
| if (s < mddev->array_sectors) { |
| 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) * new_data_disks; |
| 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. |
| */ |
| first_sector = |
| raid5_compute_sector(sector_nr*(new_data_disks), |
| raid_disks, data_disks, |
| &dd_idx, &pd_idx, conf); |
| last_sector = |
| raid5_compute_sector((sector_nr+conf->chunk_size/512) |
| *(new_data_disks) -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; |
| } |
| /* If this takes us to the resync_max point where we have to pause, |
| * then we need to write out the superblock. |
| */ |
| sector_nr += conf->chunk_size>>9; |
| if (sector_nr >= mddev->resync_max) { |
| /* 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, |
| !test_bit(MD_CHANGE_DEVS, &mddev->flags) |
| || 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); |
| } |
| return conf->chunk_size>>9; |
| } |
| |
| /* FIXME go_faster isn't used */ |
| 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 pd_idx; |
| int raid_disks = conf->raid_disks; |
| 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 /* completed sync */ |
| conf->fullsync = 0; |
| bitmap_close_sync(mddev->bitmap); |
| |
| return 0; |
| } |
| |
| if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) |
| return reshape_request(mddev, sector_nr, skipped); |
| |
| /* No need to check resync_max as we never do more than one |
| * stripe, and as resync_max will always be on a chunk boundary, |
| * if the check in md_do_sync didn't fire, there is no chance |
| * of overstepping resync_max here |
| */ |
| |
| /* 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 >= conf->max_degraded && |
| 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 */ |
| } |
| |
| |
| bitmap_cond_end_sync(mddev->bitmap, sector_nr); |
| |
| 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, raid_disks, 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); |
| |
| /* wait for any blocked device to be handled */ |
| while(unlikely(!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 < raid5_bi_hw_segments(raid_bio)) |
| /* 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 */ |
| raid5_set_bi_hw_segments(raid_bio, 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); |
| raid5_set_bi_hw_segments(raid_bio, scnt); |
| conf->retry_read_aligned = raid_bio; |
| return handled; |
| } |
| |
| handle_stripe(sh, NULL); |
| release_stripe(sh); |
| handled++; |
| } |
| spin_lock_irq(&conf->device_lock); |
| remaining = raid5_dec_bi_phys_segments(raid_bio); |
| spin_unlock_irq(&conf->device_lock); |
| if (remaining == 0) |
| bio_endio(raid_bio, 0); |
| if (atomic_dec_and_test(&conf->active_aligned_reads)) |
| wake_up(&conf->wait_for_stripe); |
| return handled; |
| } |
| |
| |
| |
| /* |
| * This is our raid5 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 raid5d(mddev_t *mddev) |
| { |
| struct stripe_head *sh; |
| raid5_conf_t *conf = mddev_to_conf(mddev); |
| int handled; |
| |
| pr_debug("+++ raid5d active\n"); |
| |
| md_check_recovery(mddev); |
| |
| handled = 0; |
| spin_lock_irq(&conf->device_lock); |
| while (1) { |
| struct bio *bio; |
| |
| if (conf->seq_flush != conf->seq_write) { |
| 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); |
| } |
| |
| 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++; |
| } |
| |
| sh = __get_priority_stripe(conf); |
| |
| if (!sh) |
| break; |
| spin_unlock_irq(&conf->device_lock); |
| |
| handled++; |
| handle_stripe(sh, conf->spare_page); |
| release_stripe(sh); |
| |
| spin_lock_irq(&conf->device_lock); |
| } |
| pr_debug("%d stripes handled\n", handled); |
| |
| spin_unlock_irq(&conf->device_lock); |
| |
| async_tx_issue_pending_all(); |
| unplug_slaves(mddev); |
| |
| pr_debug("--- raid5d inactive\n"); |
| } |
| |
| static ssize_t |
| raid5_show_stripe_cache_size(mddev_t *mddev, char *page) |
| { |
| raid5_conf_t *conf = mddev_to_conf(mddev); |
| if (conf) |
| return sprintf(page, "%d\n", conf->max_nr_stripes); |
| else |
| return 0; |
| } |
| |
| static ssize_t |
| raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) |
| { |
| raid5_conf_t *conf = mddev_to_conf(mddev); |
| unsigned long new; |
| int err; |
| |
| if (len >= PAGE_SIZE) |
| return -EINVAL; |
| if (!conf) |
| return -ENODEV; |
| |
| if (strict_strtoul(page, 10, &new)) |
| 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; |
| } |
| err = md_allow_write(mddev); |
| if (err) |
| return err; |
| while (new > conf->max_nr_stripes) { |
| if (grow_one_stripe(conf)) |
| conf->max_nr_stripes++; |
| else break; |
| } |
| return len; |
| } |
| |
| static struct md_sysfs_entry |
| raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, |
| raid5_show_stripe_cache_size, |
| raid5_store_stripe_cache_size); |
| |
| static ssize_t |
| raid5_show_preread_threshold(mddev_t *mddev, char *page) |
| { |
| raid5_conf_t *conf = mddev_to_conf(mddev); |
| if (conf) |
| return sprintf(page, "%d\n", conf->bypass_threshold); |
| else |
| return 0; |
| } |
| |
| static ssize_t |
| raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len) |
| { |
| raid5_conf_t *conf = mddev_to_conf(mddev); |
| unsigned long new; |
| if (len >= PAGE_SIZE) |
| return -EINVAL; |
| if (!conf) |
| return -ENODEV; |
| |
| if (strict_strtoul(page, 10, &new)) |
| return -EINVAL; |
| if (new > conf->max_nr_stripes) |
| return -EINVAL; |
| conf->bypass_threshold = new; |
| return len; |
| } |
| |
| static struct md_sysfs_entry |
| raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold, |
| S_IRUGO | S_IWUSR, |
| raid5_show_preread_threshold, |
| raid5_store_preread_threshold); |
| |
| static ssize_t |
| stripe_cache_active_show(mddev_t *mddev, char *page) |
| { |
| raid5_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 |
| raid5_stripecache_active = __ATTR_RO(stripe_cache_active); |
| |
| static struct attribute *raid5_attrs[] = { |
| &raid5_stripecache_size.attr, |
| &raid5_stripecache_active.attr, |
| &raid5_preread_bypass_threshold.attr, |
| NULL, |
| }; |
| static struct attribute_group raid5_attrs_group = { |
| .name = NULL, |
| .attrs = raid5_attrs, |
| }; |
| |
| static int run(mddev_t *mddev) |
| { |
| raid5_conf_t *conf; |
| int raid_disk, memory; |
| mdk_rdev_t *rdev; |
| struct disk_info *disk; |
| int working_disks = 0; |
| |
| 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; |
| } |
| |
| if (mddev->chunk_size < PAGE_SIZE) { |
| printk(KERN_ERR "md/raid5: chunk_size must be at least " |
| "PAGE_SIZE but %d < %ld\n", |
| mddev->chunk_size, PAGE_SIZE); |
| return -EINVAL; |
| } |
| |
| 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; |
| int max_degraded = (mddev->level == 5 ? 1 : 2); |
| |
| 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 - max_degraded))) { |
| 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-max_degraded)); |
| /* 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); |
| mddev->queue->queue_lock = &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->hold_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); |
| atomic_set(&conf->active_aligned_reads, 0); |
| conf->bypass_threshold = BYPASS_THRESHOLD; |
| |
| pr_debug("raid5: run(%s) called.\n", mdname(mddev)); |
| |
| list_for_each_entry(rdev, &mddev->disks, same_set) { |
| raid_disk = rdev->raid_disk; |
| if (raid_disk >= conf->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 "raid5: device %s operational as raid" |
| " disk %d\n", bdevname(rdev->bdev,b), |
| raid_disk); |
| working_disks++; |
| } else |
| /* Cannot rely on bitmap to complete recovery */ |
| conf->fullsync = 1; |
| } |
| |
| /* |
| * 0 for a fully functional array, 1 or 2 for a degraded array. |
| */ |
| 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)); |
| goto abort; |
| } |
| if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { |
| printk(KERN_ERR |
| "raid5: unsupported parity algorithm %d for %s\n", |
| conf->algorithm, mdname(mddev)); |
| goto abort; |
| } |
| if (mddev->degraded > conf->max_degraded) { |
| printk(KERN_ERR "raid5: not enough operational devices for %s" |
| " (%d/%d failed)\n", |
| mdname(mddev), mddev->degraded, conf->raid_disks); |
| goto abort; |
| } |
| |
| if (mddev->degraded > 0 && |
| mddev->recovery_cp != MaxSector) { |
| if (mddev->ok_start_degraded) |
| printk(KERN_WARNING |
| "raid5: starting dirty degraded array: %s" |
| "- data corruption possible.\n", |
| mdname(mddev)); |
| else { |
| printk(KERN_ERR |
| "raid5: cannot start dirty degraded array for %s\n", |
| mdname(mddev)); |
| goto abort; |
| } |
| } |
| |
| { |
| mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5"); |
| if (!mddev->thread) { |
| printk(KERN_ERR |
| "raid5: 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 |
| "raid5: couldn't allocate %dkB for buffers\n", memory); |
| shrink_stripes(conf); |
| md_unregister_thread(mddev->thread); |
| goto abort; |
| } else |
| printk(KERN_INFO "raid5: allocated %dkB for %s\n", |
| memory, mdname(mddev)); |
| |
| if (mddev->degraded == 0) |
| printk("raid5: 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 "raid5: 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_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 * (datadisks) * chunksize where 'n' is the number of raid devices |
| */ |
| { |
| 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; |
| } |
| |
| /* Ok, everything is just fine now */ |
| if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group)) |
| printk(KERN_WARNING |
| "raid5: failed to create sysfs attributes for %s\n", |
| mdname(mddev)); |
| |
| mddev->queue->unplug_fn = raid5_unplug_device; |
| mddev->queue->backing_dev_info.congested_data = mddev; |
| mddev->queue->backing_dev_info.congested_fn = raid5_congested; |
| |
| mddev->array_sectors = 2 * mddev->size * (conf->previous_raid_disks - |
| conf->max_degraded); |
| |
| blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); |
| |
| return 0; |
| abort: |
| if (conf) { |
| print_raid5_conf(conf); |
| safe_put_page(conf->spare_page); |
| kfree(conf->disks); |
| kfree(conf->stripe_hashtbl); |
| kfree(conf); |
| } |
| mddev->private = NULL; |
| printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev)); |
| return -EIO; |
| } |
| |
| |
| |
| static int stop(mddev_t *mddev) |
| { |
| raid5_conf_t *conf = (raid5_conf_t *) mddev->private; |
| |
| md_unregister_thread(mddev->thread); |
| mddev->thread = NULL; |
| shrink_stripes(conf); |
| kfree(conf->stripe_hashtbl); |
| mddev->queue->backing_dev_info.congested_fn = NULL; |
| 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; |
| } |
| |
| #ifdef DEBUG |
| 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->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, raid5_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++) { |
| 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) |
| { |
| raid5_conf_t *conf = (raid5_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->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, "]"); |
| #ifdef DEBUG |
| seq_printf (seq, "\n"); |
| printall(seq, conf); |
| #endif |
| } |
| |
| static void print_raid5_conf (raid5_conf_t *conf) |
| { |
| int i; |
| struct disk_info *tmp; |
| |
| printk("RAID5 conf printout:\n"); |
| if (!conf) { |
| printk("(conf==NULL)\n"); |
| return; |
| } |
| 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]; |
| 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 raid5_spare_active(mddev_t *mddev) |
| { |
| int i; |
| raid5_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_and_set_bit(In_sync, &tmp->rdev->flags)) { |
| unsigned long flags; |
| spin_lock_irqsave(&conf->device_lock, flags); |
| mddev->degraded--; |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| } |
| } |
| print_raid5_conf(conf); |
| return 0; |
| } |
| |
| static int raid5_remove_disk(mddev_t *mddev, int number) |
| { |
| raid5_conf_t *conf = mddev->private; |
| int err = 0; |
| mdk_rdev_t *rdev; |
| struct disk_info *p = conf->disks + number; |
| |
| print_raid5_conf(conf); |
| rdev = p->rdev; |
| if (rdev) { |
| if (test_bit(In_sync, &rdev->flags) || |
| atomic_read(&rdev->nr_pending)) { |
| err = -EBUSY; |
| goto abort; |
| } |
| /* Only remove non-faulty devices if recovery |
| * isn't possible. |
| */ |
| if (!test_bit(Faulty, &rdev->flags) && |
| mddev->degraded <= conf->max_degraded) { |
| 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_raid5_conf(conf); |
| return err; |
| } |
| |
| static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) |
| { |
| raid5_conf_t *conf = mddev->private; |
| int err = -EEXIST; |
| int disk; |
| struct disk_info *p; |
| int first = 0; |
| int last = conf->raid_disks - 1; |
| |
| if (mddev->degraded > conf->max_degraded) |
| /* no point adding a device */ |
| return -EINVAL; |
| |
| if (rdev->raid_disk >= 0) |
| first = last = rdev->raid_disk; |
| |
| /* |
| * find the disk ... but prefer rdev->saved_raid_disk |
| * if possible. |
| */ |
| if (rdev->saved_raid_disk >= 0 && |
| rdev->saved_raid_disk >= first && |
| conf->disks[rdev->saved_raid_disk].rdev == NULL) |
| disk = rdev->saved_raid_disk; |
| else |
| disk = first; |
| for ( ; disk <= last ; disk++) |
| if ((p=conf->disks + disk)->rdev == NULL) { |
| clear_bit(In_sync, &rdev->flags); |
| rdev->raid_disk = disk; |
| err = 0; |
| if (rdev->saved_raid_disk != disk) |
| conf->fullsync = 1; |
| rcu_assign_pointer(p->rdev, rdev); |
| break; |
| } |
| print_raid5_conf(conf); |
| return err; |
| } |
| |
| static int raid5_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. |
| */ |
| raid5_conf_t *conf = mddev_to_conf(mddev); |
| |
| sectors &= ~((sector_t)mddev->chunk_size/512 - 1); |
| mddev->array_sectors = sectors * (mddev->raid_disks |
| - conf->max_degraded); |
| set_capacity(mddev->gendisk, mddev->array_sectors); |
| 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; |
| } |
| |
| #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 */ |
| if (mddev->bitmap) |
| /* Cannot grow a bitmap yet */ |
| return -EBUSY; |
| |
| /* 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; |
| |
| if (mddev->degraded > conf->max_degraded) |
| return -EINVAL; |
| /* 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; |
| int spares = 0; |
| int added_devices = 0; |
| unsigned long flags; |
| |
| if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) |
| return -EBUSY; |
| |
| list_for_each_entry(rdev, &mddev->disks, same_set) |
| if (rdev->raid_disk < 0 && |
| !test_bit(Faulty, &rdev->flags)) |
| spares++; |
| |
| if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded) |
| /* 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. |
| */ |
| list_for_each_entry(rdev, &mddev->disks, same_set) |
| if (rdev->raid_disk < 0 && |
| !test_bit(Faulty, &rdev->flags)) { |
| if (raid5_add_disk(mddev, rdev) == 0) { |
| char nm[20]; |
| set_bit(In_sync, &rdev->flags); |
| added_devices++; |
| rdev->recovery_offset = 0; |
| sprintf(nm, "rd%d", rdev->raid_disk); |
| if (sysfs_create_link(&mddev->kobj, |
| &rdev->kobj, nm)) |
| printk(KERN_WARNING |
| "raid5: failed to create " |
| " link %s for %s\n", |
| nm, mdname(mddev)); |
| } 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_sectors = 2 * conf->mddev->size * |
| (conf->raid_disks - conf->max_degraded); |
| set_capacity(conf->mddev->gendisk, conf->mddev->array_sectors); |
| 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_sectors << 9); |
| 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_aligned_reads) == 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); |
| 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, |
| #ifdef CONFIG_MD_RAID5_RESHAPE |
| .check_reshape = raid5_check_reshape, |
| .start_reshape = raid5_start_reshape, |
| #endif |
| .quiesce = raid5_quiesce, |
| }; |
| static struct mdk_personality raid5_personality = |
| { |
| .name = "raid5", |
| .level = 5, |
| .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, |
| #ifdef CONFIG_MD_RAID5_RESHAPE |
| .check_reshape = raid5_check_reshape, |
| .start_reshape = raid5_start_reshape, |
| #endif |
| .quiesce = raid5_quiesce, |
| }; |
| |
| static struct mdk_personality raid4_personality = |
| { |
| .name = "raid4", |
| .level = 4, |
| .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, |
| #ifdef CONFIG_MD_RAID5_RESHAPE |
| .check_reshape = raid5_check_reshape, |
| .start_reshape = raid5_start_reshape, |
| #endif |
| .quiesce = raid5_quiesce, |
| }; |
| |
| 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; |
| } |
| |
| static void raid5_exit(void) |
| { |
| unregister_md_personality(&raid6_personality); |
| unregister_md_personality(&raid5_personality); |
| unregister_md_personality(&raid4_personality); |
| } |
| |
| module_init(raid5_init); |
| module_exit(raid5_exit); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("md-personality-4"); /* RAID5 */ |
| 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"); |