| /* |
| * 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->seq_write is the number of the last batch successfully written. |
| * conf->seq_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 seq_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/kthread.h> |
| #include <linux/raid/pq.h> |
| #include <linux/async_tx.h> |
| #include <linux/module.h> |
| #include <linux/async.h> |
| #include <linux/seq_file.h> |
| #include <linux/cpu.h> |
| #include <linux/slab.h> |
| #include <linux/ratelimit.h> |
| #include "md.h" |
| #include "raid5.h" |
| #include "raid0.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) |
| |
| static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect) |
| { |
| int hash = (sect >> STRIPE_SHIFT) & HASH_MASK; |
| return &conf->stripe_hashtbl[hash]; |
| } |
| |
| /* 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 function is used to determine the 'next' bio in the list, given the sector |
| * of the current stripe+device |
| */ |
| static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector) |
| { |
| int sectors = bio->bi_size >> 9; |
| if (bio->bi_sector + sectors < sector + STRIPE_SECTORS) |
| return bio->bi_next; |
| else |
| return NULL; |
| } |
| |
| /* |
| * 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_processed_stripes(struct bio *bio) |
| { |
| atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; |
| return (atomic_read(segments) >> 16) & 0xffff; |
| } |
| |
| static inline int raid5_dec_bi_active_stripes(struct bio *bio) |
| { |
| atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; |
| return atomic_sub_return(1, segments) & 0xffff; |
| } |
| |
| static inline void raid5_inc_bi_active_stripes(struct bio *bio) |
| { |
| atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; |
| atomic_inc(segments); |
| } |
| |
| static inline void raid5_set_bi_processed_stripes(struct bio *bio, |
| unsigned int cnt) |
| { |
| atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; |
| int old, new; |
| |
| do { |
| old = atomic_read(segments); |
| new = (old & 0xffff) | (cnt << 16); |
| } while (atomic_cmpxchg(segments, old, new) != old); |
| } |
| |
| static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt) |
| { |
| atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; |
| atomic_set(segments, cnt); |
| } |
| |
| /* Find first data disk in a raid6 stripe */ |
| static inline int raid6_d0(struct stripe_head *sh) |
| { |
| if (sh->ddf_layout) |
| /* ddf always start from first device */ |
| return 0; |
| /* md starts just after Q block */ |
| if (sh->qd_idx == sh->disks - 1) |
| return 0; |
| else |
| return sh->qd_idx + 1; |
| } |
| static inline int raid6_next_disk(int disk, int raid_disks) |
| { |
| disk++; |
| return (disk < raid_disks) ? disk : 0; |
| } |
| |
| /* When walking through the disks in a raid5, starting at raid6_d0, |
| * We need to map each disk to a 'slot', where the data disks are slot |
| * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk |
| * is raid_disks-1. This help does that mapping. |
| */ |
| static int raid6_idx_to_slot(int idx, struct stripe_head *sh, |
| int *count, int syndrome_disks) |
| { |
| int slot = *count; |
| |
| if (sh->ddf_layout) |
| (*count)++; |
| if (idx == sh->pd_idx) |
| return syndrome_disks; |
| if (idx == sh->qd_idx) |
| return syndrome_disks + 1; |
| if (!sh->ddf_layout) |
| (*count)++; |
| return slot; |
| } |
| |
| 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 (struct r5conf *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 do_release_stripe(struct r5conf *conf, struct stripe_head *sh) |
| { |
| 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) && |
| !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) |
| list_add_tail(&sh->lru, &conf->delayed_list); |
| else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && |
| sh->bm_seq - conf->seq_write > 0) |
| list_add_tail(&sh->lru, &conf->bitmap_list); |
| else { |
| clear_bit(STRIPE_DELAYED, &sh->state); |
| 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)) |
| if (atomic_dec_return(&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 r5conf *conf, struct stripe_head *sh) |
| { |
| if (atomic_dec_and_test(&sh->count)) |
| do_release_stripe(conf, sh); |
| } |
| |
| static void release_stripe(struct stripe_head *sh) |
| { |
| struct r5conf *conf = sh->raid_conf; |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) { |
| do_release_stripe(conf, sh); |
| spin_unlock(&conf->device_lock); |
| } |
| local_irq_restore(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(struct r5conf *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); |
| |
| 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(struct r5conf *conf) |
| { |
| struct stripe_head *sh = NULL; |
| struct list_head *first; |
| |
| 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) |
| { |
| struct page *p; |
| int i; |
| int num = sh->raid_conf->pool_size; |
| |
| 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 i; |
| int num = sh->raid_conf->pool_size; |
| |
| 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, int previous); |
| static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous, |
| struct stripe_head *sh); |
| |
| static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) |
| { |
| struct r5conf *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)); |
| |
| pr_debug("init_stripe called, stripe %llu\n", |
| (unsigned long long)sh->sector); |
| |
| remove_hash(sh); |
| |
| sh->generation = conf->generation - previous; |
| sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks; |
| sh->sector = sector; |
| stripe_set_idx(sector, conf, previous, sh); |
| sh->state = 0; |
| |
| |
| 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)); |
| WARN_ON(1); |
| } |
| dev->flags = 0; |
| raid5_build_block(sh, i, previous); |
| } |
| insert_hash(conf, sh); |
| } |
| |
| static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector, |
| short generation) |
| { |
| struct stripe_head *sh; |
| struct hlist_node *hn; |
| |
| 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->generation == generation) |
| return sh; |
| pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); |
| return NULL; |
| } |
| |
| /* |
| * Need to check if array has failed when deciding whether to: |
| * - start an array |
| * - remove non-faulty devices |
| * - add a spare |
| * - allow a reshape |
| * This determination is simple when no reshape is happening. |
| * However if there is a reshape, we need to carefully check |
| * both the before and after sections. |
| * This is because some failed devices may only affect one |
| * of the two sections, and some non-in_sync devices may |
| * be insync in the section most affected by failed devices. |
| */ |
| static int calc_degraded(struct r5conf *conf) |
| { |
| int degraded, degraded2; |
| int i; |
| |
| rcu_read_lock(); |
| degraded = 0; |
| for (i = 0; i < conf->previous_raid_disks; i++) { |
| struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); |
| if (!rdev || test_bit(Faulty, &rdev->flags)) |
| degraded++; |
| else if (test_bit(In_sync, &rdev->flags)) |
| ; |
| else |
| /* not in-sync or faulty. |
| * If the reshape increases the number of devices, |
| * this is being recovered by the reshape, so |
| * this 'previous' section is not in_sync. |
| * If the number of devices is being reduced however, |
| * the device can only be part of the array if |
| * we are reverting a reshape, so this section will |
| * be in-sync. |
| */ |
| if (conf->raid_disks >= conf->previous_raid_disks) |
| degraded++; |
| } |
| rcu_read_unlock(); |
| if (conf->raid_disks == conf->previous_raid_disks) |
| return degraded; |
| rcu_read_lock(); |
| degraded2 = 0; |
| for (i = 0; i < conf->raid_disks; i++) { |
| struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); |
| if (!rdev || test_bit(Faulty, &rdev->flags)) |
| degraded2++; |
| else if (test_bit(In_sync, &rdev->flags)) |
| ; |
| else |
| /* not in-sync or faulty. |
| * If reshape increases the number of devices, this |
| * section has already been recovered, else it |
| * almost certainly hasn't. |
| */ |
| if (conf->raid_disks <= conf->previous_raid_disks) |
| degraded2++; |
| } |
| rcu_read_unlock(); |
| if (degraded2 > degraded) |
| return degraded2; |
| return degraded; |
| } |
| |
| static int has_failed(struct r5conf *conf) |
| { |
| int degraded; |
| |
| if (conf->mddev->reshape_position == MaxSector) |
| return conf->mddev->degraded > conf->max_degraded; |
| |
| degraded = calc_degraded(conf); |
| if (degraded > conf->max_degraded) |
| return 1; |
| return 0; |
| } |
| |
| static struct stripe_head * |
| get_active_stripe(struct r5conf *conf, sector_t sector, |
| int previous, int noblock, int noquiesce) |
| { |
| 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 || noquiesce, |
| conf->device_lock, /* nothing */); |
| sh = __find_stripe(conf, sector, conf->generation - previous); |
| 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, |
| ); |
| conf->inactive_blocked = 0; |
| } else |
| init_stripe(sh, sector, previous); |
| } else { |
| if (atomic_read(&sh->count)) { |
| BUG_ON(!list_empty(&sh->lru) |
| && !test_bit(STRIPE_EXPANDING, &sh->state) |
| && !test_bit(STRIPE_ON_UNPLUG_LIST, &sh->state)); |
| } 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; |
| } |
| |
| /* Determine if 'data_offset' or 'new_data_offset' should be used |
| * in this stripe_head. |
| */ |
| static int use_new_offset(struct r5conf *conf, struct stripe_head *sh) |
| { |
| sector_t progress = conf->reshape_progress; |
| /* Need a memory barrier to make sure we see the value |
| * of conf->generation, or ->data_offset that was set before |
| * reshape_progress was updated. |
| */ |
| smp_rmb(); |
| if (progress == MaxSector) |
| return 0; |
| if (sh->generation == conf->generation - 1) |
| return 0; |
| /* We are in a reshape, and this is a new-generation stripe, |
| * so use new_data_offset. |
| */ |
| return 1; |
| } |
| |
| 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) |
| { |
| struct r5conf *conf = sh->raid_conf; |
| int i, disks = sh->disks; |
| |
| might_sleep(); |
| |
| for (i = disks; i--; ) { |
| int rw; |
| int replace_only = 0; |
| struct bio *bi, *rbi; |
| struct md_rdev *rdev, *rrdev = NULL; |
| if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) { |
| if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags)) |
| rw = WRITE_FUA; |
| else |
| rw = WRITE; |
| } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) |
| rw = READ; |
| else if (test_and_clear_bit(R5_WantReplace, |
| &sh->dev[i].flags)) { |
| rw = WRITE; |
| replace_only = 1; |
| } else |
| continue; |
| if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags)) |
| rw |= REQ_SYNC; |
| |
| bi = &sh->dev[i].req; |
| rbi = &sh->dev[i].rreq; /* For writing to replacement */ |
| |
| bi->bi_rw = rw; |
| rbi->bi_rw = rw; |
| if (rw & WRITE) { |
| bi->bi_end_io = raid5_end_write_request; |
| rbi->bi_end_io = raid5_end_write_request; |
| } else |
| bi->bi_end_io = raid5_end_read_request; |
| |
| rcu_read_lock(); |
| rrdev = rcu_dereference(conf->disks[i].replacement); |
| smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */ |
| rdev = rcu_dereference(conf->disks[i].rdev); |
| if (!rdev) { |
| rdev = rrdev; |
| rrdev = NULL; |
| } |
| if (rw & WRITE) { |
| if (replace_only) |
| rdev = NULL; |
| if (rdev == rrdev) |
| /* We raced and saw duplicates */ |
| rrdev = NULL; |
| } else { |
| if (test_bit(R5_ReadRepl, &sh->dev[i].flags) && rrdev) |
| rdev = rrdev; |
| rrdev = NULL; |
| } |
| |
| if (rdev && test_bit(Faulty, &rdev->flags)) |
| rdev = NULL; |
| if (rdev) |
| atomic_inc(&rdev->nr_pending); |
| if (rrdev && test_bit(Faulty, &rrdev->flags)) |
| rrdev = NULL; |
| if (rrdev) |
| atomic_inc(&rrdev->nr_pending); |
| rcu_read_unlock(); |
| |
| /* We have already checked bad blocks for reads. Now |
| * need to check for writes. We never accept write errors |
| * on the replacement, so we don't to check rrdev. |
| */ |
| while ((rw & WRITE) && rdev && |
| test_bit(WriteErrorSeen, &rdev->flags)) { |
| sector_t first_bad; |
| int bad_sectors; |
| int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS, |
| &first_bad, &bad_sectors); |
| if (!bad) |
| break; |
| |
| if (bad < 0) { |
| set_bit(BlockedBadBlocks, &rdev->flags); |
| if (!conf->mddev->external && |
| conf->mddev->flags) { |
| /* It is very unlikely, but we might |
| * still need to write out the |
| * bad block log - better give it |
| * a chance*/ |
| md_check_recovery(conf->mddev); |
| } |
| /* |
| * Because md_wait_for_blocked_rdev |
| * will dec nr_pending, we must |
| * increment it first. |
| */ |
| atomic_inc(&rdev->nr_pending); |
| md_wait_for_blocked_rdev(rdev, conf->mddev); |
| } else { |
| /* Acknowledged bad block - skip the write */ |
| rdev_dec_pending(rdev, conf->mddev); |
| rdev = NULL; |
| } |
| } |
| |
| if (rdev) { |
| if (s->syncing || s->expanding || s->expanded |
| || s->replacing) |
| 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); |
| if (use_new_offset(conf, sh)) |
| bi->bi_sector = (sh->sector |
| + rdev->new_data_offset); |
| else |
| bi->bi_sector = (sh->sector |
| + rdev->data_offset); |
| if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) |
| bi->bi_rw |= REQ_FLUSH; |
| |
| bi->bi_flags = 1 << BIO_UPTODATE; |
| bi->bi_idx = 0; |
| 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 (rrdev) |
| set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags); |
| generic_make_request(bi); |
| } |
| if (rrdev) { |
| if (s->syncing || s->expanding || s->expanded |
| || s->replacing) |
| md_sync_acct(rrdev->bdev, STRIPE_SECTORS); |
| |
| set_bit(STRIPE_IO_STARTED, &sh->state); |
| |
| rbi->bi_bdev = rrdev->bdev; |
| pr_debug("%s: for %llu schedule op %ld on " |
| "replacement disc %d\n", |
| __func__, (unsigned long long)sh->sector, |
| rbi->bi_rw, i); |
| atomic_inc(&sh->count); |
| if (use_new_offset(conf, sh)) |
| rbi->bi_sector = (sh->sector |
| + rrdev->new_data_offset); |
| else |
| rbi->bi_sector = (sh->sector |
| + rrdev->data_offset); |
| rbi->bi_flags = 1 << BIO_UPTODATE; |
| rbi->bi_idx = 0; |
| rbi->bi_io_vec[0].bv_len = STRIPE_SIZE; |
| rbi->bi_io_vec[0].bv_offset = 0; |
| rbi->bi_size = STRIPE_SIZE; |
| rbi->bi_next = NULL; |
| generic_make_request(rbi); |
| } |
| if (!rdev && !rrdev) { |
| 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; |
| struct async_submit_ctl submit; |
| enum async_tx_flags flags = 0; |
| |
| if (bio->bi_sector >= sector) |
| page_offset = (signed)(bio->bi_sector - sector) * 512; |
| else |
| page_offset = (signed)(sector - bio->bi_sector) * -512; |
| |
| if (frombio) |
| flags |= ASYNC_TX_FENCE; |
| init_async_submit(&submit, flags, tx, NULL, NULL, NULL); |
| |
| bio_for_each_segment(bvl, bio, i) { |
| int len = bvl->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 += bvl->bv_offset; |
| bio_page = bvl->bv_page; |
| if (frombio) |
| tx = async_memcpy(page, bio_page, page_offset, |
| b_offset, clen, &submit); |
| else |
| tx = async_memcpy(bio_page, page, b_offset, |
| page_offset, clen, &submit); |
| } |
| /* chain the operations */ |
| submit.depend_tx = tx; |
| |
| 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; |
| int i; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| /* clear completed biofills */ |
| 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_active_stripes(rbi)) { |
| rbi->bi_next = return_bi; |
| return_bi = rbi; |
| } |
| rbi = rbi2; |
| } |
| } |
| } |
| 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; |
| struct async_submit_ctl submit; |
| 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(&sh->stripe_lock); |
| dev->read = rbi = dev->toread; |
| dev->toread = NULL; |
| spin_unlock_irq(&sh->stripe_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); |
| init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL); |
| async_trigger_callback(&submit); |
| } |
| |
| static void mark_target_uptodate(struct stripe_head *sh, int target) |
| { |
| struct r5dev *tgt; |
| |
| if (target < 0) |
| return; |
| |
| tgt = &sh->dev[target]; |
| set_bit(R5_UPTODATE, &tgt->flags); |
| BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
| clear_bit(R5_Wantcompute, &tgt->flags); |
| } |
| |
| static void ops_complete_compute(void *stripe_head_ref) |
| { |
| struct stripe_head *sh = stripe_head_ref; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| /* mark the computed target(s) as uptodate */ |
| mark_target_uptodate(sh, sh->ops.target); |
| mark_target_uptodate(sh, sh->ops.target2); |
| |
| 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); |
| } |
| |
| /* return a pointer to the address conversion region of the scribble buffer */ |
| static addr_conv_t *to_addr_conv(struct stripe_head *sh, |
| struct raid5_percpu *percpu) |
| { |
| return percpu->scribble + sizeof(struct page *) * (sh->disks + 2); |
| } |
| |
| static struct dma_async_tx_descriptor * |
| ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) |
| { |
| int disks = sh->disks; |
| struct page **xor_srcs = percpu->scribble; |
| 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; |
| struct async_submit_ctl submit; |
| 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); |
| |
| init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL, |
| ops_complete_compute, sh, to_addr_conv(sh, percpu)); |
| if (unlikely(count == 1)) |
| tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); |
| else |
| tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); |
| |
| return tx; |
| } |
| |
| /* set_syndrome_sources - populate source buffers for gen_syndrome |
| * @srcs - (struct page *) array of size sh->disks |
| * @sh - stripe_head to parse |
| * |
| * Populates srcs in proper layout order for the stripe and returns the |
| * 'count' of sources to be used in a call to async_gen_syndrome. The P |
| * destination buffer is recorded in srcs[count] and the Q destination |
| * is recorded in srcs[count+1]]. |
| */ |
| static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh) |
| { |
| int disks = sh->disks; |
| int syndrome_disks = sh->ddf_layout ? disks : (disks - 2); |
| int d0_idx = raid6_d0(sh); |
| int count; |
| int i; |
| |
| for (i = 0; i < disks; i++) |
| srcs[i] = NULL; |
| |
| count = 0; |
| i = d0_idx; |
| do { |
| int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); |
| |
| srcs[slot] = sh->dev[i].page; |
| i = raid6_next_disk(i, disks); |
| } while (i != d0_idx); |
| |
| return syndrome_disks; |
| } |
| |
| static struct dma_async_tx_descriptor * |
| ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu) |
| { |
| int disks = sh->disks; |
| struct page **blocks = percpu->scribble; |
| int target; |
| int qd_idx = sh->qd_idx; |
| struct dma_async_tx_descriptor *tx; |
| struct async_submit_ctl submit; |
| struct r5dev *tgt; |
| struct page *dest; |
| int i; |
| int count; |
| |
| if (sh->ops.target < 0) |
| target = sh->ops.target2; |
| else if (sh->ops.target2 < 0) |
| target = sh->ops.target; |
| else |
| /* we should only have one valid target */ |
| BUG(); |
| BUG_ON(target < 0); |
| pr_debug("%s: stripe %llu block: %d\n", |
| __func__, (unsigned long long)sh->sector, target); |
| |
| tgt = &sh->dev[target]; |
| BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
| dest = tgt->page; |
| |
| atomic_inc(&sh->count); |
| |
| if (target == qd_idx) { |
| count = set_syndrome_sources(blocks, sh); |
| blocks[count] = NULL; /* regenerating p is not necessary */ |
| BUG_ON(blocks[count+1] != dest); /* q should already be set */ |
| init_async_submit(&submit, ASYNC_TX_FENCE, NULL, |
| ops_complete_compute, sh, |
| to_addr_conv(sh, percpu)); |
| tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); |
| } else { |
| /* Compute any data- or p-drive using XOR */ |
| count = 0; |
| for (i = disks; i-- ; ) { |
| if (i == target || i == qd_idx) |
| continue; |
| blocks[count++] = sh->dev[i].page; |
| } |
| |
| init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, |
| NULL, ops_complete_compute, sh, |
| to_addr_conv(sh, percpu)); |
| tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit); |
| } |
| |
| return tx; |
| } |
| |
| static struct dma_async_tx_descriptor * |
| ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) |
| { |
| int i, count, disks = sh->disks; |
| int syndrome_disks = sh->ddf_layout ? disks : disks-2; |
| int d0_idx = raid6_d0(sh); |
| int faila = -1, failb = -1; |
| int target = sh->ops.target; |
| int target2 = sh->ops.target2; |
| struct r5dev *tgt = &sh->dev[target]; |
| struct r5dev *tgt2 = &sh->dev[target2]; |
| struct dma_async_tx_descriptor *tx; |
| struct page **blocks = percpu->scribble; |
| struct async_submit_ctl submit; |
| |
| pr_debug("%s: stripe %llu block1: %d block2: %d\n", |
| __func__, (unsigned long long)sh->sector, target, target2); |
| BUG_ON(target < 0 || target2 < 0); |
| BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); |
| BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags)); |
| |
| /* we need to open-code set_syndrome_sources to handle the |
| * slot number conversion for 'faila' and 'failb' |
| */ |
| for (i = 0; i < disks ; i++) |
| blocks[i] = NULL; |
| count = 0; |
| i = d0_idx; |
| do { |
| int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); |
| |
| blocks[slot] = sh->dev[i].page; |
| |
| if (i == target) |
| faila = slot; |
| if (i == target2) |
| failb = slot; |
| i = raid6_next_disk(i, disks); |
| } while (i != d0_idx); |
| |
| BUG_ON(faila == failb); |
| if (failb < faila) |
| swap(faila, failb); |
| pr_debug("%s: stripe: %llu faila: %d failb: %d\n", |
| __func__, (unsigned long long)sh->sector, faila, failb); |
| |
| atomic_inc(&sh->count); |
| |
| if (failb == syndrome_disks+1) { |
| /* Q disk is one of the missing disks */ |
| if (faila == syndrome_disks) { |
| /* Missing P+Q, just recompute */ |
| init_async_submit(&submit, ASYNC_TX_FENCE, NULL, |
| ops_complete_compute, sh, |
| to_addr_conv(sh, percpu)); |
| return async_gen_syndrome(blocks, 0, syndrome_disks+2, |
| STRIPE_SIZE, &submit); |
| } else { |
| struct page *dest; |
| int data_target; |
| int qd_idx = sh->qd_idx; |
| |
| /* Missing D+Q: recompute D from P, then recompute Q */ |
| if (target == qd_idx) |
| data_target = target2; |
| else |
| data_target = target; |
| |
| count = 0; |
| for (i = disks; i-- ; ) { |
| if (i == data_target || i == qd_idx) |
| continue; |
| blocks[count++] = sh->dev[i].page; |
| } |
| dest = sh->dev[data_target].page; |
| init_async_submit(&submit, |
| ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, |
| NULL, NULL, NULL, |
| to_addr_conv(sh, percpu)); |
| tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, |
| &submit); |
| |
| count = set_syndrome_sources(blocks, sh); |
| init_async_submit(&submit, ASYNC_TX_FENCE, tx, |
| ops_complete_compute, sh, |
| to_addr_conv(sh, percpu)); |
| return async_gen_syndrome(blocks, 0, count+2, |
| STRIPE_SIZE, &submit); |
| } |
| } else { |
| init_async_submit(&submit, ASYNC_TX_FENCE, NULL, |
| ops_complete_compute, sh, |
| to_addr_conv(sh, percpu)); |
| if (failb == syndrome_disks) { |
| /* We're missing D+P. */ |
| return async_raid6_datap_recov(syndrome_disks+2, |
| STRIPE_SIZE, faila, |
| blocks, &submit); |
| } else { |
| /* We're missing D+D. */ |
| return async_raid6_2data_recov(syndrome_disks+2, |
| STRIPE_SIZE, faila, failb, |
| blocks, &submit); |
| } |
| } |
| } |
| |
| |
| 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 raid5_percpu *percpu, |
| struct dma_async_tx_descriptor *tx) |
| { |
| int disks = sh->disks; |
| struct page **xor_srcs = percpu->scribble; |
| int count = 0, pd_idx = sh->pd_idx, i; |
| struct async_submit_ctl submit; |
| |
| /* 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; |
| } |
| |
| init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
| ops_complete_prexor, sh, to_addr_conv(sh, percpu)); |
| tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); |
| |
| 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_irq(&sh->stripe_lock); |
| chosen = dev->towrite; |
| dev->towrite = NULL; |
| BUG_ON(dev->written); |
| wbi = dev->written = chosen; |
| spin_unlock_irq(&sh->stripe_lock); |
| |
| while (wbi && wbi->bi_sector < |
| dev->sector + STRIPE_SECTORS) { |
| if (wbi->bi_rw & REQ_FUA) |
| set_bit(R5_WantFUA, &dev->flags); |
| if (wbi->bi_rw & REQ_SYNC) |
| set_bit(R5_SyncIO, &dev->flags); |
| tx = async_copy_data(1, wbi, dev->page, |
| dev->sector, tx); |
| wbi = r5_next_bio(wbi, dev->sector); |
| } |
| } |
| } |
| |
| return tx; |
| } |
| |
| static void ops_complete_reconstruct(void *stripe_head_ref) |
| { |
| struct stripe_head *sh = stripe_head_ref; |
| int disks = sh->disks; |
| int pd_idx = sh->pd_idx; |
| int qd_idx = sh->qd_idx; |
| int i; |
| bool fua = false, sync = false; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| for (i = disks; i--; ) { |
| fua |= test_bit(R5_WantFUA, &sh->dev[i].flags); |
| sync |= test_bit(R5_SyncIO, &sh->dev[i].flags); |
| } |
| |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| |
| if (dev->written || i == pd_idx || i == qd_idx) { |
| set_bit(R5_UPTODATE, &dev->flags); |
| if (fua) |
| set_bit(R5_WantFUA, &dev->flags); |
| if (sync) |
| set_bit(R5_SyncIO, &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_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, |
| struct dma_async_tx_descriptor *tx) |
| { |
| int disks = sh->disks; |
| struct page **xor_srcs = percpu->scribble; |
| struct async_submit_ctl submit; |
| 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_ACK | |
| (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); |
| |
| atomic_inc(&sh->count); |
| |
| init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh, |
| to_addr_conv(sh, percpu)); |
| if (unlikely(count == 1)) |
| tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); |
| else |
| tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); |
| } |
| |
| static void |
| ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu, |
| struct dma_async_tx_descriptor *tx) |
| { |
| struct async_submit_ctl submit; |
| struct page **blocks = percpu->scribble; |
| int count; |
| |
| pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); |
| |
| count = set_syndrome_sources(blocks, sh); |
| |
| atomic_inc(&sh->count); |
| |
| init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct, |
| sh, to_addr_conv(sh, percpu)); |
| async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); |
| } |
| |
| 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_p(struct stripe_head *sh, struct raid5_percpu *percpu) |
| { |
| int disks = sh->disks; |
| int pd_idx = sh->pd_idx; |
| int qd_idx = sh->qd_idx; |
| struct page *xor_dest; |
| struct page **xor_srcs = percpu->scribble; |
| struct dma_async_tx_descriptor *tx; |
| struct async_submit_ctl submit; |
| int count; |
| int i; |
| |
| pr_debug("%s: stripe %llu\n", __func__, |
| (unsigned long long)sh->sector); |
| |
| count = 0; |
| xor_dest = sh->dev[pd_idx].page; |
| xor_srcs[count++] = xor_dest; |
| for (i = disks; i--; ) { |
| if (i == pd_idx || i == qd_idx) |
| continue; |
| xor_srcs[count++] = sh->dev[i].page; |
| } |
| |
| init_async_submit(&submit, 0, NULL, NULL, NULL, |
| to_addr_conv(sh, percpu)); |
| tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, |
| &sh->ops.zero_sum_result, &submit); |
| |
| atomic_inc(&sh->count); |
| init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL); |
| tx = async_trigger_callback(&submit); |
| } |
| |
| static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp) |
| { |
| struct page **srcs = percpu->scribble; |
| struct async_submit_ctl submit; |
| int count; |
| |
| pr_debug("%s: stripe %llu checkp: %d\n", __func__, |
| (unsigned long long)sh->sector, checkp); |
| |
| count = set_syndrome_sources(srcs, sh); |
| if (!checkp) |
| srcs[count] = NULL; |
| |
| atomic_inc(&sh->count); |
| init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check, |
| sh, to_addr_conv(sh, percpu)); |
| async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE, |
| &sh->ops.zero_sum_result, percpu->spare_page, &submit); |
| } |
| |
| static void __raid_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; |
| struct r5conf *conf = sh->raid_conf; |
| int level = conf->level; |
| struct raid5_percpu *percpu; |
| unsigned long cpu; |
| |
| cpu = get_cpu(); |
| percpu = per_cpu_ptr(conf->percpu, cpu); |
| if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { |
| ops_run_biofill(sh); |
| overlap_clear++; |
| } |
| |
| if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) { |
| if (level < 6) |
| tx = ops_run_compute5(sh, percpu); |
| else { |
| if (sh->ops.target2 < 0 || sh->ops.target < 0) |
| tx = ops_run_compute6_1(sh, percpu); |
| else |
| tx = ops_run_compute6_2(sh, percpu); |
| } |
| /* terminate the chain if reconstruct is not set to be run */ |
| if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) |
| async_tx_ack(tx); |
| } |
| |
| if (test_bit(STRIPE_OP_PREXOR, &ops_request)) |
| tx = ops_run_prexor(sh, percpu, tx); |
| |
| if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { |
| tx = ops_run_biodrain(sh, tx); |
| overlap_clear++; |
| } |
| |
| if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) { |
| if (level < 6) |
| ops_run_reconstruct5(sh, percpu, tx); |
| else |
| ops_run_reconstruct6(sh, percpu, tx); |
| } |
| |
| if (test_bit(STRIPE_OP_CHECK, &ops_request)) { |
| if (sh->check_state == check_state_run) |
| ops_run_check_p(sh, percpu); |
| else if (sh->check_state == check_state_run_q) |
| ops_run_check_pq(sh, percpu, 0); |
| else if (sh->check_state == check_state_run_pq) |
| ops_run_check_pq(sh, percpu, 1); |
| else |
| BUG(); |
| } |
| |
| 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); |
| } |
| put_cpu(); |
| } |
| |
| #ifdef CONFIG_MULTICORE_RAID456 |
| static void async_run_ops(void *param, async_cookie_t cookie) |
| { |
| struct stripe_head *sh = param; |
| unsigned long ops_request = sh->ops.request; |
| |
| clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state); |
| wake_up(&sh->ops.wait_for_ops); |
| |
| __raid_run_ops(sh, ops_request); |
| release_stripe(sh); |
| } |
| |
| static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) |
| { |
| /* since handle_stripe can be called outside of raid5d context |
| * we need to ensure sh->ops.request is de-staged before another |
| * request arrives |
| */ |
| wait_event(sh->ops.wait_for_ops, |
| !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state)); |
| sh->ops.request = ops_request; |
| |
| atomic_inc(&sh->count); |
| async_schedule(async_run_ops, sh); |
| } |
| #else |
| #define raid_run_ops __raid_run_ops |
| #endif |
| |
| static int grow_one_stripe(struct r5conf *conf) |
| { |
| struct stripe_head *sh; |
| sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL); |
| if (!sh) |
| return 0; |
| |
| sh->raid_conf = conf; |
| #ifdef CONFIG_MULTICORE_RAID456 |
| init_waitqueue_head(&sh->ops.wait_for_ops); |
| #endif |
| |
| spin_lock_init(&sh->stripe_lock); |
| |
| if (grow_buffers(sh)) { |
| shrink_buffers(sh); |
| kmem_cache_free(conf->slab_cache, sh); |
| return 0; |
| } |
| /* we just created an active stripe so... */ |
| atomic_set(&sh->count, 1); |
| atomic_inc(&conf->active_stripes); |
| INIT_LIST_HEAD(&sh->lru); |
| release_stripe(sh); |
| return 1; |
| } |
| |
| static int grow_stripes(struct r5conf *conf, int num) |
| { |
| struct kmem_cache *sc; |
| int devs = max(conf->raid_disks, conf->previous_raid_disks); |
| |
| if (conf->mddev->gendisk) |
| sprintf(conf->cache_name[0], |
| "raid%d-%s", conf->level, mdname(conf->mddev)); |
| else |
| sprintf(conf->cache_name[0], |
| "raid%d-%p", conf->level, conf->mddev); |
| sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]); |
| |
| 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; |
| } |
| |
| /** |
| * scribble_len - return the required size of the scribble region |
| * @num - total number of disks in the array |
| * |
| * The size must be enough to contain: |
| * 1/ a struct page pointer for each device in the array +2 |
| * 2/ room to convert each entry in (1) to its corresponding dma |
| * (dma_map_page()) or page (page_address()) address. |
| * |
| * Note: the +2 is for the destination buffers of the ddf/raid6 case where we |
| * calculate over all devices (not just the data blocks), using zeros in place |
| * of the P and Q blocks. |
| */ |
| static size_t scribble_len(int num) |
| { |
| size_t len; |
| |
| len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2); |
| |
| return len; |
| } |
| |
| static int resize_stripes(struct r5conf *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; |
| unsigned long cpu; |
| 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_zalloc(sc, GFP_KERNEL); |
| if (!nsh) |
| break; |
| |
| nsh->raid_conf = conf; |
| #ifdef CONFIG_MULTICORE_RAID456 |
| init_waitqueue_head(&nsh->ops.wait_for_ops); |
| #endif |
| |
| 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, |
| ); |
| 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 and the scribble region |
| */ |
| 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; |
| |
| get_online_cpus(); |
| conf->scribble_len = scribble_len(newsize); |
| for_each_present_cpu(cpu) { |
| struct raid5_percpu *percpu; |
| void *scribble; |
| |
| percpu = per_cpu_ptr(conf->percpu, cpu); |
| scribble = kmalloc(conf->scribble_len, GFP_NOIO); |
| |
| if (scribble) { |
| kfree(percpu->scribble); |
| percpu->scribble = scribble; |
| } else { |
| err = -ENOMEM; |
| break; |
| } |
| } |
| put_online_cpus(); |
| |
| /* Step 4, return new stripes to service */ |
| while(!list_empty(&newstripes)) { |
| nsh = list_entry(newstripes.next, struct stripe_head, lru); |
| list_del_init(&nsh->lru); |
| |
| for (i=conf->raid_disks; i < newsize; i++) |
| if (nsh->dev[i].page == NULL) { |
| struct page *p = alloc_page(GFP_NOIO); |
| nsh->dev[i].page = p; |
| if (!p) |
| err = -ENOMEM; |
| } |
| release_stripe(nsh); |
| } |
| /* critical section pass, GFP_NOIO no longer needed */ |
| |
| conf->slab_cache = sc; |
| conf->active_name = 1-conf->active_name; |
| conf->pool_size = newsize; |
| return err; |
| } |
| |
| static int drop_one_stripe(struct r5conf *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); |
| kmem_cache_free(conf->slab_cache, sh); |
| atomic_dec(&conf->active_stripes); |
| return 1; |
| } |
| |
| static void shrink_stripes(struct r5conf *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; |
| struct r5conf *conf = sh->raid_conf; |
| int disks = sh->disks, i; |
| int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
| char b[BDEVNAME_SIZE]; |
| struct md_rdev *rdev = NULL; |
| sector_t s; |
| |
| 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 (test_bit(R5_ReadRepl, &sh->dev[i].flags)) |
| /* If replacement finished while this request was outstanding, |
| * 'replacement' might be NULL already. |
| * In that case it moved down to 'rdev'. |
| * rdev is not removed until all requests are finished. |
| */ |
| rdev = conf->disks[i].replacement; |
| if (!rdev) |
| rdev = conf->disks[i].rdev; |
| |
| if (use_new_offset(conf, sh)) |
| s = sh->sector + rdev->new_data_offset; |
| else |
| s = sh->sector + rdev->data_offset; |
| if (uptodate) { |
| set_bit(R5_UPTODATE, &sh->dev[i].flags); |
| if (test_bit(R5_ReadError, &sh->dev[i].flags)) { |
| /* Note that this cannot happen on a |
| * replacement device. We just fail those on |
| * any error |
| */ |
| printk_ratelimited( |
| KERN_INFO |
| "md/raid:%s: read error corrected" |
| " (%lu sectors at %llu on %s)\n", |
| mdname(conf->mddev), STRIPE_SECTORS, |
| (unsigned long long)s, |
| bdevname(rdev->bdev, b)); |
| atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); |
| clear_bit(R5_ReadError, &sh->dev[i].flags); |
| clear_bit(R5_ReWrite, &sh->dev[i].flags); |
| } else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) |
| clear_bit(R5_ReadNoMerge, &sh->dev[i].flags); |
| |
| if (atomic_read(&rdev->read_errors)) |
| atomic_set(&rdev->read_errors, 0); |
| } else { |
| const char *bdn = bdevname(rdev->bdev, b); |
| int retry = 0; |
| int set_bad = 0; |
| |
| clear_bit(R5_UPTODATE, &sh->dev[i].flags); |
| atomic_inc(&rdev->read_errors); |
| if (test_bit(R5_ReadRepl, &sh->dev[i].flags)) |
| printk_ratelimited( |
| KERN_WARNING |
| "md/raid:%s: read error on replacement device " |
| "(sector %llu on %s).\n", |
| mdname(conf->mddev), |
| (unsigned long long)s, |
| bdn); |
| else if (conf->mddev->degraded >= conf->max_degraded) { |
| set_bad = 1; |
| printk_ratelimited( |
| KERN_WARNING |
| "md/raid:%s: read error not correctable " |
| "(sector %llu on %s).\n", |
| mdname(conf->mddev), |
| (unsigned long long)s, |
| bdn); |
| } else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) { |
| /* Oh, no!!! */ |
| set_bad = 1; |
| printk_ratelimited( |
| KERN_WARNING |
| "md/raid:%s: read error NOT corrected!! " |
| "(sector %llu on %s).\n", |
| mdname(conf->mddev), |
| (unsigned long long)s, |
| bdn); |
| } else if (atomic_read(&rdev->read_errors) |
| > conf->max_nr_stripes) |
| printk(KERN_WARNING |
| "md/raid:%s: Too many read errors, failing device %s.\n", |
| mdname(conf->mddev), bdn); |
| else |
| retry = 1; |
| if (retry) |
| if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) { |
| set_bit(R5_ReadError, &sh->dev[i].flags); |
| clear_bit(R5_ReadNoMerge, &sh->dev[i].flags); |
| } else |
| set_bit(R5_ReadNoMerge, &sh->dev[i].flags); |
| else { |
| clear_bit(R5_ReadError, &sh->dev[i].flags); |
| clear_bit(R5_ReWrite, &sh->dev[i].flags); |
| if (!(set_bad |
| && test_bit(In_sync, &rdev->flags) |
| && rdev_set_badblocks( |
| rdev, sh->sector, STRIPE_SECTORS, 0))) |
| md_error(conf->mddev, rdev); |
| } |
| } |
| rdev_dec_pending(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; |
| struct r5conf *conf = sh->raid_conf; |
| int disks = sh->disks, i; |
| struct md_rdev *uninitialized_var(rdev); |
| int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
| sector_t first_bad; |
| int bad_sectors; |
| int replacement = 0; |
| |
| for (i = 0 ; i < disks; i++) { |
| if (bi == &sh->dev[i].req) { |
| rdev = conf->disks[i].rdev; |
| break; |
| } |
| if (bi == &sh->dev[i].rreq) { |
| rdev = conf->disks[i].replacement; |
| if (rdev) |
| replacement = 1; |
| else |
| /* rdev was removed and 'replacement' |
| * replaced it. rdev is not removed |
| * until all requests are finished. |
| */ |
| rdev = conf->disks[i].rdev; |
| 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 (replacement) { |
| if (!uptodate) |
| md_error(conf->mddev, rdev); |
| else if (is_badblock(rdev, sh->sector, |
| STRIPE_SECTORS, |
| &first_bad, &bad_sectors)) |
| set_bit(R5_MadeGoodRepl, &sh->dev[i].flags); |
| } else { |
| if (!uptodate) { |
| set_bit(WriteErrorSeen, &rdev->flags); |
| set_bit(R5_WriteError, &sh->dev[i].flags); |
| if (!test_and_set_bit(WantReplacement, &rdev->flags)) |
| set_bit(MD_RECOVERY_NEEDED, |
| &rdev->mddev->recovery); |
| } else if (is_badblock(rdev, sh->sector, |
| STRIPE_SECTORS, |
| &first_bad, &bad_sectors)) |
| set_bit(R5_MadeGood, &sh->dev[i].flags); |
| } |
| rdev_dec_pending(rdev, conf->mddev); |
| |
| if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags)) |
| 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, int previous); |
| |
| static void raid5_build_block(struct stripe_head *sh, int i, int previous) |
| { |
| 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->req.bi_private = sh; |
| dev->vec.bv_page = dev->page; |
| |
| bio_init(&dev->rreq); |
| dev->rreq.bi_io_vec = &dev->rvec; |
| dev->rreq.bi_vcnt++; |
| dev->rreq.bi_max_vecs++; |
| dev->rreq.bi_private = sh; |
| dev->rvec.bv_page = dev->page; |
| |
| dev->flags = 0; |
| dev->sector = compute_blocknr(sh, i, previous); |
| } |
| |
| static void error(struct mddev *mddev, struct md_rdev *rdev) |
| { |
| char b[BDEVNAME_SIZE]; |
| struct r5conf *conf = mddev->private; |
| unsigned long flags; |
| pr_debug("raid456: error called\n"); |
| |
| spin_lock_irqsave(&conf->device_lock, flags); |
| clear_bit(In_sync, &rdev->flags); |
| mddev->degraded = calc_degraded(conf); |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| set_bit(MD_RECOVERY_INTR, &mddev->recovery); |
| |
| set_bit(Blocked, &rdev->flags); |
| set_bit(Faulty, &rdev->flags); |
| set_bit(MD_CHANGE_DEVS, &mddev->flags); |
| printk(KERN_ALERT |
| "md/raid:%s: Disk failure on %s, disabling device.\n" |
| "md/raid:%s: Operation continuing on %d devices.\n", |
| mdname(mddev), |
| bdevname(rdev->bdev, b), |
| mdname(mddev), |
| 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(struct r5conf *conf, sector_t r_sector, |
| int previous, int *dd_idx, |
| struct stripe_head *sh) |
| { |
| sector_t stripe, stripe2; |
| sector_t chunk_number; |
| unsigned int chunk_offset; |
| int pd_idx, qd_idx; |
| int ddf_layout = 0; |
| sector_t new_sector; |
| int algorithm = previous ? conf->prev_algo |
| : conf->algorithm; |
| int sectors_per_chunk = previous ? conf->prev_chunk_sectors |
| : conf->chunk_sectors; |
| int raid_disks = previous ? conf->previous_raid_disks |
| : conf->raid_disks; |
| int data_disks = raid_disks - conf->max_degraded; |
| |
| /* 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; |
| |
| /* |
| * Compute the stripe number |
| */ |
| stripe = chunk_number; |
| *dd_idx = sector_div(stripe, data_disks); |
| stripe2 = stripe; |
| /* |
| * Select the parity disk based on the user selected algorithm. |
| */ |
| pd_idx = qd_idx = -1; |
| switch(conf->level) { |
| case 4: |
| pd_idx = data_disks; |
| break; |
| case 5: |
| switch (algorithm) { |
| case ALGORITHM_LEFT_ASYMMETRIC: |
| pd_idx = data_disks - sector_div(stripe2, raid_disks); |
| if (*dd_idx >= pd_idx) |
| (*dd_idx)++; |
| break; |
| case ALGORITHM_RIGHT_ASYMMETRIC: |
| pd_idx = sector_div(stripe2, raid_disks); |
| if (*dd_idx >= pd_idx) |
| (*dd_idx)++; |
| break; |
| case ALGORITHM_LEFT_SYMMETRIC: |
| pd_idx = data_disks - sector_div(stripe2, raid_disks); |
| *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; |
| break; |
| case ALGORITHM_RIGHT_SYMMETRIC: |
| pd_idx = sector_div(stripe2, raid_disks); |
| *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; |
| break; |
| case ALGORITHM_PARITY_0: |
| pd_idx = 0; |
| (*dd_idx)++; |
| break; |
| case ALGORITHM_PARITY_N: |
| pd_idx = data_disks; |
| break; |
| default: |
| BUG(); |
| } |
| break; |
| case 6: |
| |
| switch (algorithm) { |
| case ALGORITHM_LEFT_ASYMMETRIC: |
| pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); |
| qd_idx = pd_idx + 1; |
| if (pd_idx == raid_disks-1) { |
| (*dd_idx)++; /* Q D D D P */ |
| qd_idx = 0; |
| } else if (*dd_idx >= pd_idx) |
| (*dd_idx) += 2; /* D D P Q D */ |
| break; |
| case ALGORITHM_RIGHT_ASYMMETRIC: |
| pd_idx = sector_div(stripe2, raid_disks); |
| qd_idx = pd_idx + 1; |
| if (pd_idx == raid_disks-1) { |
| (*dd_idx)++; /* Q D D D P */ |
| qd_idx = 0; |
| } else if (*dd_idx >= pd_idx) |
| (*dd_idx) += 2; /* D D P Q D */ |
| break; |
| case ALGORITHM_LEFT_SYMMETRIC: |
| pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); |
| qd_idx = (pd_idx + 1) % raid_disks; |
| *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; |
| break; |
| case ALGORITHM_RIGHT_SYMMETRIC: |
| pd_idx = sector_div(stripe2, raid_disks); |
| qd_idx = (pd_idx + 1) % raid_disks; |
| *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; |
| break; |
| |
| case ALGORITHM_PARITY_0: |
| pd_idx = 0; |
| qd_idx = 1; |
| (*dd_idx) += 2; |
| break; |
| case ALGORITHM_PARITY_N: |
| pd_idx = data_disks; |
| qd_idx = data_disks + 1; |
| break; |
| |
| case ALGORITHM_ROTATING_ZERO_RESTART: |
| /* Exactly the same as RIGHT_ASYMMETRIC, but or |
| * of blocks for computing Q is different. |
| */ |
| pd_idx = sector_div(stripe2, raid_disks); |
| qd_idx = pd_idx + 1; |
| if (pd_idx == raid_disks-1) { |
| (*dd_idx)++; /* Q D D D P */ |
| qd_idx = 0; |
| } else if (*dd_idx >= pd_idx) |
| (*dd_idx) += 2; /* D D P Q D */ |
| ddf_layout = 1; |
| break; |
| |
| case ALGORITHM_ROTATING_N_RESTART: |
| /* Same a left_asymmetric, by first stripe is |
| * D D D P Q rather than |
| * Q D D D P |
| */ |
| stripe2 += 1; |
| pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); |
| qd_idx = pd_idx + 1; |
| if (pd_idx == raid_disks-1) { |
| (*dd_idx)++; /* Q D D D P */ |
| qd_idx = 0; |
| } else if (*dd_idx >= pd_idx) |
| (*dd_idx) += 2; /* D D P Q D */ |
| ddf_layout = 1; |
| break; |
| |
| case ALGORITHM_ROTATING_N_CONTINUE: |
| /* Same as left_symmetric but Q is before P */ |
| pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); |
| qd_idx = (pd_idx + raid_disks - 1) % raid_disks; |
| *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; |
| ddf_layout = 1; |
| break; |
| |
| case ALGORITHM_LEFT_ASYMMETRIC_6: |
| /* RAID5 left_asymmetric, with Q on last device */ |
| pd_idx = data_disks - sector_div(stripe2, raid_disks-1); |
| if (*dd_idx >= pd_idx) |
| (*dd_idx)++; |
| qd_idx = raid_disks - 1; |
| break; |
| |
| case ALGORITHM_RIGHT_ASYMMETRIC_6: |
| pd_idx = sector_div(stripe2, raid_disks-1); |
| if (*dd_idx >= pd_idx) |
| (*dd_idx)++; |
| qd_idx = raid_disks - 1; |
| break; |
| |
| case ALGORITHM_LEFT_SYMMETRIC_6: |
| pd_idx = data_disks - sector_div(stripe2, raid_disks-1); |
| *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); |
| qd_idx = raid_disks - 1; |
| break; |
| |
| case ALGORITHM_RIGHT_SYMMETRIC_6: |
| pd_idx = sector_div(stripe2, raid_disks-1); |
| *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); |
| qd_idx = raid_disks - 1; |
| break; |
| |
| case ALGORITHM_PARITY_0_6: |
| pd_idx = 0; |
| (*dd_idx)++; |
| qd_idx = raid_disks - 1; |
| break; |
| |
| default: |
| BUG(); |
| } |
| break; |
| } |
| |
| if (sh) { |
| sh->pd_idx = pd_idx; |
| sh->qd_idx = qd_idx; |
| sh->ddf_layout = ddf_layout; |
| } |
| /* |
| * 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, int previous) |
| { |
| struct r5conf *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 = previous ? conf->prev_chunk_sectors |
| : conf->chunk_sectors; |
| int algorithm = previous ? conf->prev_algo |
| : conf->algorithm; |
| sector_t stripe; |
| int chunk_offset; |
| sector_t chunk_number; |
| int dummy1, dd_idx = i; |
| sector_t r_sector; |
| struct stripe_head sh2; |
| |
| |
| chunk_offset = sector_div(new_sector, sectors_per_chunk); |
| stripe = new_sector; |
| |
| if (i == sh->pd_idx) |
| return 0; |
| switch(conf->level) { |
| case 4: break; |
| case 5: |
| switch (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; |
| case ALGORITHM_PARITY_0: |
| i -= 1; |
| break; |
| case ALGORITHM_PARITY_N: |
| break; |
| default: |
| BUG(); |
| } |
| break; |
| case 6: |
| if (i == sh->qd_idx) |
| return 0; /* It is the Q disk */ |
| switch (algorithm) { |
| case ALGORITHM_LEFT_ASYMMETRIC: |
| case ALGORITHM_RIGHT_ASYMMETRIC: |
| case ALGORITHM_ROTATING_ZERO_RESTART: |
| case ALGORITHM_ROTATING_N_RESTART: |
| 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; |
| case ALGORITHM_PARITY_0: |
| i -= 2; |
| break; |
| case ALGORITHM_PARITY_N: |
| break; |
| case ALGORITHM_ROTATING_N_CONTINUE: |
| /* Like left_symmetric, but P is before Q */ |
| if (sh->pd_idx == 0) |
| i--; /* P D D D Q */ |
| else { |
| /* D D Q P D */ |
| if (i < sh->pd_idx) |
| i += raid_disks; |
| i -= (sh->pd_idx + 1); |
| } |
| break; |
| case ALGORITHM_LEFT_ASYMMETRIC_6: |
| case ALGORITHM_RIGHT_ASYMMETRIC_6: |
| if (i > sh->pd_idx) |
| i--; |
| break; |
| case ALGORITHM_LEFT_SYMMETRIC_6: |
| case ALGORITHM_RIGHT_SYMMETRIC_6: |
| if (i < sh->pd_idx) |
| i += data_disks + 1; |
| i -= (sh->pd_idx + 1); |
| break; |
| case ALGORITHM_PARITY_0_6: |
| i -= 1; |
| break; |
| default: |
| BUG(); |
| } |
| break; |
| } |
| |
| chunk_number = stripe * data_disks + i; |
| r_sector = chunk_number * sectors_per_chunk + chunk_offset; |
| |
| check = raid5_compute_sector(conf, r_sector, |
| previous, &dummy1, &sh2); |
| if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx |
| || sh2.qd_idx != sh->qd_idx) { |
| printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n", |
| mdname(conf->mddev)); |
| return 0; |
| } |
| return r_sector; |
| } |
| |
| |
| static void |
| schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, |
| int rcw, int expand) |
| { |
| int i, pd_idx = sh->pd_idx, disks = sh->disks; |
| struct r5conf *conf = sh->raid_conf; |
| int level = conf->level; |
| |
| 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_RECONSTRUCT, &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 + conf->max_degraded == disks) |
| if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) |
| atomic_inc(&conf->pending_full_writes); |
| } else { |
| BUG_ON(level == 6); |
| 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_RECONSTRUCT, &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(s) 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++; |
| |
| if (level == 6) { |
| int qd_idx = sh->qd_idx; |
| struct r5dev *dev = &sh->dev[qd_idx]; |
| |
| set_bit(R5_LOCKED, &dev->flags); |
| clear_bit(R5_UPTODATE, &dev->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; |
| struct r5conf *conf = sh->raid_conf; |
| int firstwrite=0; |
| |
| pr_debug("adding bi b#%llu to stripe s#%llu\n", |
| (unsigned long long)bi->bi_sector, |
| (unsigned long long)sh->sector); |
| |
| /* |
| * If several bio share a stripe. The bio bi_phys_segments acts as a |
| * reference count to avoid race. The reference count should already be |
| * increased before this function is called (for example, in |
| * make_request()), so other bio sharing this stripe will not free the |
| * stripe. If a stripe is owned by one stripe, the stripe lock will |
| * protect it. |
| */ |
| spin_lock_irq(&sh->stripe_lock); |
| if (forwrite) { |
| bip = &sh->dev[dd_idx].towrite; |
| if (*bip == 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; |
| raid5_inc_bi_active_stripes(bi); |
| |
| 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); |
| } |
| spin_unlock_irq(&sh->stripe_lock); |
| |
| pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", |
| (unsigned long long)(*bip)->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); |
| } |
| return 1; |
| |
| overlap: |
| set_bit(R5_Overlap, &sh->dev[dd_idx].flags); |
| spin_unlock_irq(&sh->stripe_lock); |
| return 0; |
| } |
| |
| static void end_reshape(struct r5conf *conf); |
| |
| static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous, |
| struct stripe_head *sh) |
| { |
| int sectors_per_chunk = |
| previous ? conf->prev_chunk_sectors : conf->chunk_sectors; |
| int dd_idx; |
| int chunk_offset = sector_div(stripe, sectors_per_chunk); |
| int disks = previous ? conf->previous_raid_disks : conf->raid_disks; |
| |
| raid5_compute_sector(conf, |
| stripe * (disks - conf->max_degraded) |
| *sectors_per_chunk + chunk_offset, |
| previous, |
| &dd_idx, sh); |
| } |
| |
| static void |
| handle_failed_stripe(struct r5conf *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)) { |
| struct md_rdev *rdev; |
| rcu_read_lock(); |
| rdev = rcu_dereference(conf->disks[i].rdev); |
| if (rdev && test_bit(In_sync, &rdev->flags)) |
| atomic_inc(&rdev->nr_pending); |
| else |
| rdev = NULL; |
| rcu_read_unlock(); |
| if (rdev) { |
| if (!rdev_set_badblocks( |
| rdev, |
| sh->sector, |
| STRIPE_SECTORS, 0)) |
| md_error(conf->mddev, rdev); |
| rdev_dec_pending(rdev, conf->mddev); |
| } |
| } |
| spin_lock_irq(&sh->stripe_lock); |
| /* fail all writes first */ |
| bi = sh->dev[i].towrite; |
| sh->dev[i].towrite = NULL; |
| spin_unlock_irq(&sh->stripe_lock); |
| 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_active_stripes(bi)) { |
| md_write_end(conf->mddev); |
| bi->bi_next = *return_bi; |
| *return_bi = bi; |
| } |
| bi = nextbi; |
| } |
| if (bitmap_end) |
| bitmap_endwrite(conf->mddev->bitmap, sh->sector, |
| STRIPE_SECTORS, 0, 0); |
| bitmap_end = 0; |
| /* 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_active_stripes(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_active_stripes(bi)) { |
| bi->bi_next = *return_bi; |
| *return_bi = bi; |
| } |
| bi = nextbi; |
| } |
| } |
| if (bitmap_end) |
| bitmap_endwrite(conf->mddev->bitmap, sh->sector, |
| STRIPE_SECTORS, 0, 0); |
| /* If we were in the middle of a write the parity block might |
| * still be locked - so just clear all R5_LOCKED flags |
| */ |
| clear_bit(R5_LOCKED, &sh->dev[i].flags); |
| } |
| |
| 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_failed_sync(struct r5conf *conf, struct stripe_head *sh, |
| struct stripe_head_state *s) |
| { |
| int abort = 0; |
| int i; |
| |
| clear_bit(STRIPE_SYNCING, &sh->state); |
| s->syncing = 0; |
| s->replacing = 0; |
| /* There is nothing more to do for sync/check/repair. |
| * Don't even need to abort as that is handled elsewhere |
| * if needed, and not always wanted e.g. if there is a known |
| * bad block here. |
| * For recover/replace we need to record a bad block on all |
| * non-sync devices, or abort the recovery |
| */ |
| if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) { |
| /* During recovery devices cannot be removed, so |
| * locking and refcounting of rdevs is not needed |
| */ |
| for (i = 0; i < conf->raid_disks; i++) { |
| struct md_rdev *rdev = conf->disks[i].rdev; |
| if (rdev |
| && !test_bit(Faulty, &rdev->flags) |
| && !test_bit(In_sync, &rdev->flags) |
| && !rdev_set_badblocks(rdev, sh->sector, |
| STRIPE_SECTORS, 0)) |
| abort = 1; |
| rdev = conf->disks[i].replacement; |
| if (rdev |
| && !test_bit(Faulty, &rdev->flags) |
| && !test_bit(In_sync, &rdev->flags) |
| && !rdev_set_badblocks(rdev, sh->sector, |
| STRIPE_SECTORS, 0)) |
| abort = 1; |
| } |
| if (abort) |
| conf->recovery_disabled = |
| conf->mddev->recovery_disabled; |
| } |
| md_done_sync(conf->mddev, STRIPE_SECTORS, !abort); |
| } |
| |
| static int want_replace(struct stripe_head *sh, int disk_idx) |
| { |
| struct md_rdev *rdev; |
| int rv = 0; |
| /* Doing recovery so rcu locking not required */ |
| rdev = sh->raid_conf->disks[disk_idx].replacement; |
| if (rdev |
| && !test_bit(Faulty, &rdev->flags) |
| && !test_bit(In_sync, &rdev->flags) |
| && (rdev->recovery_offset <= sh->sector |
| || rdev->mddev->recovery_cp <= sh->sector)) |
| rv = 1; |
| |
| return rv; |
| } |
| |
| /* fetch_block - 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_fill to continue |
| */ |
| static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s, |
| int disk_idx, int disks) |
| { |
| struct r5dev *dev = &sh->dev[disk_idx]; |
| struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]], |
| &sh->dev[s->failed_num[1]] }; |
| |
| /* 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->replacing && want_replace(sh, disk_idx)) || |
| (s->failed >= 1 && fdev[0]->toread) || |
| (s->failed >= 2 && fdev[1]->toread) || |
| (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite && |
| !test_bit(R5_OVERWRITE, &fdev[0]->flags)) || |
| (sh->raid_conf->level == 6 && s->failed && s->to_write))) { |
| /* we would like to get this block, possibly by computing it, |
| * otherwise read it if the backing disk is insync |
| */ |
| BUG_ON(test_bit(R5_Wantcompute, &dev->flags)); |
| BUG_ON(test_bit(R5_Wantread, &dev->flags)); |
| if ((s->uptodate == disks - 1) && |
| (s->failed && (disk_idx == s->failed_num[0] || |
| disk_idx == s->failed_num[1]))) { |
| /* have disk failed, and we're requested to fetch it; |
| * do compute it |
| */ |
| pr_debug("Computing stripe %llu block %d\n", |
| (unsigned long long)sh->sector, disk_idx); |
| 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; |
| sh->ops.target2 = -1; /* no 2nd target */ |
| s->req_compute = 1; |
| /* Careful: from this point on 'uptodate' is in the eye |
| * of raid_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; |
| } 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 == disk_idx) |
| 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, |
| disk_idx, other); |
| set_bit(STRIPE_COMPUTE_RUN, &sh->state); |
| set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); |
| set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags); |
| set_bit(R5_Wantcompute, &sh->dev[other].flags); |
| sh->ops.target = disk_idx; |
| sh->ops.target2 = other; |
| s->uptodate += 2; |
| s->req_compute = 1; |
| return 1; |
| } 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_fill - read or compute data to satisfy pending requests. |
| */ |
| static void handle_stripe_fill(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_block(sh, s, i, disks)) |
| break; |
| 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(struct r5conf *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; |
| pr_debug("Return write for disc %d\n", i); |
| 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_active_stripes(wbi)) { |
| md_write_end(conf->mddev); |
| wbi->bi_next = *return_bi; |
| *return_bi = wbi; |
| } |
| wbi = wbi2; |
| } |
| 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_dirtying(struct r5conf *conf, |
| struct stripe_head *sh, |
| struct stripe_head_state *s, |
| int disks) |
| { |
| int rmw = 0, rcw = 0, i; |
| if (conf->max_degraded == 2) { |
| /* RAID6 requires 'rcw' in current implementation |
| * Calculate the real rcw later - for now fake it |
| * look like rcw is cheaper |
| */ |
| rcw = 1; rmw = 2; |
| } else 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 */ |
| rcw = 0; |
| for (i = disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| if (!test_bit(R5_OVERWRITE, &dev->flags) && |
| i != sh->pd_idx && i != sh->qd_idx && |
| !test_bit(R5_LOCKED, &dev->flags) && |
| !(test_bit(R5_UPTODATE, &dev->flags) || |
| test_bit |