diff options
Diffstat (limited to 'drivers/md/raid5.c')
| -rw-r--r-- | drivers/md/raid5.c | 8528 |
1 files changed, 8528 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c new file mode 100644 index 000000000..c7bda4b0b --- /dev/null +++ b/drivers/md/raid5.c @@ -0,0 +1,8528 @@ +/* + * 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 <linux/nodemask.h> +#include <linux/flex_array.h> + +#include <trace/events/block.h> +#include <linux/list_sort.h> + +#include "md.h" +#include "raid5.h" +#include "raid0.h" +#include "md-bitmap.h" +#include "raid5-log.h" + +#define UNSUPPORTED_MDDEV_FLAGS (1L << MD_FAILFAST_SUPPORTED) + +#define cpu_to_group(cpu) cpu_to_node(cpu) +#define ANY_GROUP NUMA_NO_NODE + +static bool devices_handle_discard_safely = false; +module_param(devices_handle_discard_safely, bool, 0644); +MODULE_PARM_DESC(devices_handle_discard_safely, + "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions"); +static struct workqueue_struct *raid5_wq; + +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]; +} + +static inline int stripe_hash_locks_hash(sector_t sect) +{ + return (sect >> STRIPE_SHIFT) & STRIPE_HASH_LOCKS_MASK; +} + +static inline void lock_device_hash_lock(struct r5conf *conf, int hash) +{ + spin_lock_irq(conf->hash_locks + hash); + spin_lock(&conf->device_lock); +} + +static inline void unlock_device_hash_lock(struct r5conf *conf, int hash) +{ + spin_unlock(&conf->device_lock); + spin_unlock_irq(conf->hash_locks + hash); +} + +static inline void lock_all_device_hash_locks_irq(struct r5conf *conf) +{ + int i; + spin_lock_irq(conf->hash_locks); + for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++) + spin_lock_nest_lock(conf->hash_locks + i, conf->hash_locks); + spin_lock(&conf->device_lock); +} + +static inline void unlock_all_device_hash_locks_irq(struct r5conf *conf) +{ + int i; + spin_unlock(&conf->device_lock); + for (i = NR_STRIPE_HASH_LOCKS - 1; i; i--) + spin_unlock(conf->hash_locks + i); + spin_unlock_irq(conf->hash_locks); +} + +/* 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 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 bool stripe_is_lowprio(struct stripe_head *sh) +{ + return (test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state) || + test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) && + !test_bit(STRIPE_R5C_CACHING, &sh->state); +} + +static void raid5_wakeup_stripe_thread(struct stripe_head *sh) +{ + struct r5conf *conf = sh->raid_conf; + struct r5worker_group *group; + int thread_cnt; + int i, cpu = sh->cpu; + + if (!cpu_online(cpu)) { + cpu = cpumask_any(cpu_online_mask); + sh->cpu = cpu; + } + + if (list_empty(&sh->lru)) { + struct r5worker_group *group; + group = conf->worker_groups + cpu_to_group(cpu); + if (stripe_is_lowprio(sh)) + list_add_tail(&sh->lru, &group->loprio_list); + else + list_add_tail(&sh->lru, &group->handle_list); + group->stripes_cnt++; + sh->group = group; + } + + if (conf->worker_cnt_per_group == 0) { + md_wakeup_thread(conf->mddev->thread); + return; + } + + group = conf->worker_groups + cpu_to_group(sh->cpu); + + group->workers[0].working = true; + /* at least one worker should run to avoid race */ + queue_work_on(sh->cpu, raid5_wq, &group->workers[0].work); + + thread_cnt = group->stripes_cnt / MAX_STRIPE_BATCH - 1; + /* wakeup more workers */ + for (i = 1; i < conf->worker_cnt_per_group && thread_cnt > 0; i++) { + if (group->workers[i].working == false) { + group->workers[i].working = true; + queue_work_on(sh->cpu, raid5_wq, + &group->workers[i].work); + thread_cnt--; + } + } +} + +static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh, + struct list_head *temp_inactive_list) +{ + int i; + int injournal = 0; /* number of date pages with R5_InJournal */ + + BUG_ON(!list_empty(&sh->lru)); + BUG_ON(atomic_read(&conf->active_stripes)==0); + + if (r5c_is_writeback(conf->log)) + for (i = sh->disks; i--; ) + if (test_bit(R5_InJournal, &sh->dev[i].flags)) + injournal++; + /* + * In the following cases, the stripe cannot be released to cached + * lists. Therefore, we make the stripe write out and set + * STRIPE_HANDLE: + * 1. when quiesce in r5c write back; + * 2. when resync is requested fot the stripe. + */ + if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) || + (conf->quiesce && r5c_is_writeback(conf->log) && + !test_bit(STRIPE_HANDLE, &sh->state) && injournal != 0)) { + if (test_bit(STRIPE_R5C_CACHING, &sh->state)) + r5c_make_stripe_write_out(sh); + set_bit(STRIPE_HANDLE, &sh->state); + } + + 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); + if (conf->worker_cnt_per_group == 0) { + if (stripe_is_lowprio(sh)) + list_add_tail(&sh->lru, + &conf->loprio_list); + else + list_add_tail(&sh->lru, + &conf->handle_list); + } else { + raid5_wakeup_stripe_thread(sh); + return; + } + } + 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)) { + if (!r5c_is_writeback(conf->log)) + list_add_tail(&sh->lru, temp_inactive_list); + else { + WARN_ON(test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags)); + if (injournal == 0) + list_add_tail(&sh->lru, temp_inactive_list); + else if (injournal == conf->raid_disks - conf->max_degraded) { + /* full stripe */ + if (!test_and_set_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) + atomic_inc(&conf->r5c_cached_full_stripes); + if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) + atomic_dec(&conf->r5c_cached_partial_stripes); + list_add_tail(&sh->lru, &conf->r5c_full_stripe_list); + r5c_check_cached_full_stripe(conf); + } else + /* + * STRIPE_R5C_PARTIAL_STRIPE is set in + * r5c_try_caching_write(). No need to + * set it again. + */ + list_add_tail(&sh->lru, &conf->r5c_partial_stripe_list); + } + } + } +} + +static void __release_stripe(struct r5conf *conf, struct stripe_head *sh, + struct list_head *temp_inactive_list) +{ + if (atomic_dec_and_test(&sh->count)) + do_release_stripe(conf, sh, temp_inactive_list); +} + +/* + * @hash could be NR_STRIPE_HASH_LOCKS, then we have a list of inactive_list + * + * Be careful: Only one task can add/delete stripes from temp_inactive_list at + * given time. Adding stripes only takes device lock, while deleting stripes + * only takes hash lock. + */ +static void release_inactive_stripe_list(struct r5conf *conf, + struct list_head *temp_inactive_list, + int hash) +{ + int size; + bool do_wakeup = false; + unsigned long flags; + + if (hash == NR_STRIPE_HASH_LOCKS) { + size = NR_STRIPE_HASH_LOCKS; + hash = NR_STRIPE_HASH_LOCKS - 1; + } else + size = 1; + while (size) { + struct list_head *list = &temp_inactive_list[size - 1]; + + /* + * We don't hold any lock here yet, raid5_get_active_stripe() might + * remove stripes from the list + */ + if (!list_empty_careful(list)) { + spin_lock_irqsave(conf->hash_locks + hash, flags); + if (list_empty(conf->inactive_list + hash) && + !list_empty(list)) + atomic_dec(&conf->empty_inactive_list_nr); + list_splice_tail_init(list, conf->inactive_list + hash); + do_wakeup = true; + spin_unlock_irqrestore(conf->hash_locks + hash, flags); + } + size--; + hash--; + } + + if (do_wakeup) { + wake_up(&conf->wait_for_stripe); + if (atomic_read(&conf->active_stripes) == 0) + wake_up(&conf->wait_for_quiescent); + if (conf->retry_read_aligned) + md_wakeup_thread(conf->mddev->thread); + } +} + +/* should hold conf->device_lock already */ +static int release_stripe_list(struct r5conf *conf, + struct list_head *temp_inactive_list) +{ + struct stripe_head *sh, *t; + int count = 0; + struct llist_node *head; + + head = llist_del_all(&conf->released_stripes); + head = llist_reverse_order(head); + llist_for_each_entry_safe(sh, t, head, release_list) { + int hash; + + /* sh could be readded after STRIPE_ON_RELEASE_LIST is cleard */ + smp_mb(); + clear_bit(STRIPE_ON_RELEASE_LIST, &sh->state); + /* + * Don't worry the bit is set here, because if the bit is set + * again, the count is always > 1. This is true for + * STRIPE_ON_UNPLUG_LIST bit too. + */ + hash = sh->hash_lock_index; + __release_stripe(conf, sh, &temp_inactive_list[hash]); + count++; + } + + return count; +} + +void raid5_release_stripe(struct stripe_head *sh) +{ + struct r5conf *conf = sh->raid_conf; + unsigned long flags; + struct list_head list; + int hash; + bool wakeup; + + /* Avoid release_list until the last reference. + */ + if (atomic_add_unless(&sh->count, -1, 1)) + return; + + if (unlikely(!conf->mddev->thread) || + test_and_set_bit(STRIPE_ON_RELEASE_LIST, &sh->state)) + goto slow_path; + wakeup = llist_add(&sh->release_list, &conf->released_stripes); + if (wakeup) + md_wakeup_thread(conf->mddev->thread); + return; +slow_path: + /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */ + if (atomic_dec_and_lock_irqsave(&sh->count, &conf->device_lock, flags)) { + INIT_LIST_HEAD(&list); + hash = sh->hash_lock_index; + do_release_stripe(conf, sh, &list); + spin_unlock_irqrestore(&conf->device_lock, flags); + release_inactive_stripe_list(conf, &list, hash); + } +} + +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, int hash) +{ + struct stripe_head *sh = NULL; + struct list_head *first; + + if (list_empty(conf->inactive_list + hash)) + goto out; + first = (conf->inactive_list + hash)->next; + sh = list_entry(first, struct stripe_head, lru); + list_del_init(first); + remove_hash(sh); + atomic_inc(&conf->active_stripes); + BUG_ON(hash != sh->hash_lock_index); + if (list_empty(conf->inactive_list + hash)) + atomic_inc(&conf->empty_inactive_list_nr); +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++) { + WARN_ON(sh->dev[i].page != sh->dev[i].orig_page); + p = sh->dev[i].page; + if (!p) + continue; + sh->dev[i].page = NULL; + put_page(p); + } +} + +static int grow_buffers(struct stripe_head *sh, gfp_t gfp) +{ + int i; + int num = sh->raid_conf->pool_size; + + for (i = 0; i < num; i++) { + struct page *page; + + if (!(page = alloc_page(gfp))) { + return 1; + } + sh->dev[i].page = page; + sh->dev[i].orig_page = page; + } + + return 0; +} + +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, seq; + + BUG_ON(atomic_read(&sh->count) != 0); + BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); + BUG_ON(stripe_operations_active(sh)); + BUG_ON(sh->batch_head); + + pr_debug("init_stripe called, stripe %llu\n", + (unsigned long long)sector); +retry: + seq = read_seqcount_begin(&conf->gen_lock); + 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)) { + pr_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; + dev->sector = raid5_compute_blocknr(sh, i, previous); + } + if (read_seqcount_retry(&conf->gen_lock, seq)) + goto retry; + sh->overwrite_disks = 0; + insert_hash(conf, sh); + sh->cpu = smp_processor_id(); + set_bit(STRIPE_BATCH_READY, &sh->state); +} + +static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector, + short generation) +{ + struct stripe_head *sh; + + pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); + hlist_for_each_entry(sh, 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. + */ +int raid5_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)) + rdev = rcu_dereference(conf->disks[i].replacement); + 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)) + rdev = rcu_dereference(conf->disks[i].replacement); + 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 = raid5_calc_degraded(conf); + if (degraded > conf->max_degraded) + return 1; + return 0; +} + +struct stripe_head * +raid5_get_active_stripe(struct r5conf *conf, sector_t sector, + int previous, int noblock, int noquiesce) +{ + struct stripe_head *sh; + int hash = stripe_hash_locks_hash(sector); + int inc_empty_inactive_list_flag; + + pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector); + + spin_lock_irq(conf->hash_locks + hash); + + do { + wait_event_lock_irq(conf->wait_for_quiescent, + conf->quiesce == 0 || noquiesce, + *(conf->hash_locks + hash)); + sh = __find_stripe(conf, sector, conf->generation - previous); + if (!sh) { + if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) { + sh = get_free_stripe(conf, hash); + if (!sh && !test_bit(R5_DID_ALLOC, + &conf->cache_state)) + set_bit(R5_ALLOC_MORE, + &conf->cache_state); + } + if (noblock && sh == NULL) + break; + + r5c_check_stripe_cache_usage(conf); + if (!sh) { + set_bit(R5_INACTIVE_BLOCKED, + &conf->cache_state); + r5l_wake_reclaim(conf->log, 0); + wait_event_lock_irq( + conf->wait_for_stripe, + !list_empty(conf->inactive_list + hash) && + (atomic_read(&conf->active_stripes) + < (conf->max_nr_stripes * 3 / 4) + || !test_bit(R5_INACTIVE_BLOCKED, + &conf->cache_state)), + *(conf->hash_locks + hash)); + clear_bit(R5_INACTIVE_BLOCKED, + &conf->cache_state); + } else { + init_stripe(sh, sector, previous); + atomic_inc(&sh->count); + } + } else if (!atomic_inc_not_zero(&sh->count)) { + spin_lock(&conf->device_lock); + if (!atomic_read(&sh->count)) { + if (!test_bit(STRIPE_HANDLE, &sh->state)) + atomic_inc(&conf->active_stripes); + BUG_ON(list_empty(&sh->lru) && + !test_bit(STRIPE_EXPANDING, &sh->state)); + inc_empty_inactive_list_flag = 0; + if (!list_empty(conf->inactive_list + hash)) + inc_empty_inactive_list_flag = 1; + list_del_init(&sh->lru); + if (list_empty(conf->inactive_list + hash) && inc_empty_inactive_list_flag) + atomic_inc(&conf->empty_inactive_list_nr); + if (sh->group) { + sh->group->stripes_cnt--; + sh->group = NULL; + } + } + atomic_inc(&sh->count); + spin_unlock(&conf->device_lock); + } + } while (sh == NULL); + + spin_unlock_irq(conf->hash_locks + hash); + return sh; +} + +static bool is_full_stripe_write(struct stripe_head *sh) +{ + BUG_ON(sh->overwrite_disks > (sh->disks - sh->raid_conf->max_degraded)); + return sh->overwrite_disks == (sh->disks - sh->raid_conf->max_degraded); +} + +static void lock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2) +{ + if (sh1 > sh2) { + spin_lock_irq(&sh2->stripe_lock); + spin_lock_nested(&sh1->stripe_lock, 1); + } else { + spin_lock_irq(&sh1->stripe_lock); + spin_lock_nested(&sh2->stripe_lock, 1); + } +} + +static void unlock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2) +{ + spin_unlock(&sh1->stripe_lock); + spin_unlock_irq(&sh2->stripe_lock); +} + +/* Only freshly new full stripe normal write stripe can be added to a batch list */ +static bool stripe_can_batch(struct stripe_head *sh) +{ + struct r5conf *conf = sh->raid_conf; + + if (raid5_has_log(conf) || raid5_has_ppl(conf)) + return false; + return test_bit(STRIPE_BATCH_READY, &sh->state) && + !test_bit(STRIPE_BITMAP_PENDING, &sh->state) && + is_full_stripe_write(sh); +} + +/* we only do back search */ +static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh) +{ + struct stripe_head *head; + sector_t head_sector, tmp_sec; + int hash; + int dd_idx; + int inc_empty_inactive_list_flag; + + /* Don't cross chunks, so stripe pd_idx/qd_idx is the same */ + tmp_sec = sh->sector; + if (!sector_div(tmp_sec, conf->chunk_sectors)) + return; + head_sector = sh->sector - STRIPE_SECTORS; + + hash = stripe_hash_locks_hash(head_sector); + spin_lock_irq(conf->hash_locks + hash); + head = __find_stripe(conf, head_sector, conf->generation); + if (head && !atomic_inc_not_zero(&head->count)) { + spin_lock(&conf->device_lock); + if (!atomic_read(&head->count)) { + if (!test_bit(STRIPE_HANDLE, &head->state)) + atomic_inc(&conf->active_stripes); + BUG_ON(list_empty(&head->lru) && + !test_bit(STRIPE_EXPANDING, &head->state)); + inc_empty_inactive_list_flag = 0; + if (!list_empty(conf->inactive_list + hash)) + inc_empty_inactive_list_flag = 1; + list_del_init(&head->lru); + if (list_empty(conf->inactive_list + hash) && inc_empty_inactive_list_flag) + atomic_inc(&conf->empty_inactive_list_nr); + if (head->group) { + head->group->stripes_cnt--; + head->group = NULL; + } + } + atomic_inc(&head->count); + spin_unlock(&conf->device_lock); + } + spin_unlock_irq(conf->hash_locks + hash); + + if (!head) + return; + if (!stripe_can_batch(head)) + goto out; + + lock_two_stripes(head, sh); + /* clear_batch_ready clear the flag */ + if (!stripe_can_batch(head) || !stripe_can_batch(sh)) + goto unlock_out; + + if (sh->batch_head) + goto unlock_out; + + dd_idx = 0; + while (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx) + dd_idx++; + if (head->dev[dd_idx].towrite->bi_opf != sh->dev[dd_idx].towrite->bi_opf || + bio_op(head->dev[dd_idx].towrite) != bio_op(sh->dev[dd_idx].towrite)) + goto unlock_out; + + if (head->batch_head) { + spin_lock(&head->batch_head->batch_lock); + /* This batch list is already running */ + if (!stripe_can_batch(head)) { + spin_unlock(&head->batch_head->batch_lock); + goto unlock_out; + } + /* + * We must assign batch_head of this stripe within the + * batch_lock, otherwise clear_batch_ready of batch head + * stripe could clear BATCH_READY bit of this stripe and + * this stripe->batch_head doesn't get assigned, which + * could confuse clear_batch_ready for this stripe + */ + sh->batch_head = head->batch_head; + + /* + * at this point, head's BATCH_READY could be cleared, but we + * can still add the stripe to batch list + */ + list_add(&sh->batch_list, &head->batch_list); + spin_unlock(&head->batch_head->batch_lock); + } else { + head->batch_head = head; + sh->batch_head = head->batch_head; + spin_lock(&head->batch_lock); + list_add_tail(&sh->batch_list, &head->batch_list); + spin_unlock(&head->batch_lock); + } + + 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); + + if (test_and_clear_bit(STRIPE_BIT_DELAY, &sh->state)) { + int seq = sh->bm_seq; + if (test_bit(STRIPE_BIT_DELAY, &sh->batch_head->state) && + sh->batch_head->bm_seq > seq) + seq = sh->batch_head->bm_seq; + set_bit(STRIPE_BIT_DELAY, &sh->batch_head->state); + sh->batch_head->bm_seq = seq; + } + + atomic_inc(&sh->count); +unlock_out: + unlock_two_stripes(head, sh); +out: + raid5_release_stripe(head); +} + +/* 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 dispatch_bio_list(struct bio_list *tmp) +{ + struct bio *bio; + + while ((bio = bio_list_pop(tmp))) + generic_make_request(bio); +} + +static int cmp_stripe(void *priv, struct list_head *a, struct list_head *b) +{ + const struct r5pending_data *da = list_entry(a, + struct r5pending_data, sibling); + const struct r5pending_data *db = list_entry(b, + struct r5pending_data, sibling); + if (da->sector > db->sector) + return 1; + if (da->sector < db->sector) + return -1; + return 0; +} + +static void dispatch_defer_bios(struct r5conf *conf, int target, + struct bio_list *list) +{ + struct r5pending_data *data; + struct list_head *first, *next = NULL; + int cnt = 0; + + if (conf->pending_data_cnt == 0) + return; + + list_sort(NULL, &conf->pending_list, cmp_stripe); + + first = conf->pending_list.next; + + /* temporarily move the head */ + if (conf->next_pending_data) + list_move_tail(&conf->pending_list, + &conf->next_pending_data->sibling); + + while (!list_empty(&conf->pending_list)) { + data = list_first_entry(&conf->pending_list, + struct r5pending_data, sibling); + if (&data->sibling == first) + first = data->sibling.next; + next = data->sibling.next; + + bio_list_merge(list, &data->bios); + list_move(&data->sibling, &conf->free_list); + cnt++; + if (cnt >= target) + break; + } + conf->pending_data_cnt -= cnt; + BUG_ON(conf->pending_data_cnt < 0 || cnt < target); + + if (next != &conf->pending_list) + conf->next_pending_data = list_entry(next, + struct r5pending_data, sibling); + else + conf->next_pending_data = NULL; + /* list isn't empty */ + if (first != &conf->pending_list) + list_move_tail(&conf->pending_list, first); +} + +static void flush_deferred_bios(struct r5conf *conf) +{ + struct bio_list tmp = BIO_EMPTY_LIST; + + if (conf->pending_data_cnt == 0) + return; + + spin_lock(&conf->pending_bios_lock); + dispatch_defer_bios(conf, conf->pending_data_cnt, &tmp); + BUG_ON(conf->pending_data_cnt != 0); + spin_unlock(&conf->pending_bios_lock); + + dispatch_bio_list(&tmp); +} + +static void defer_issue_bios(struct r5conf *conf, sector_t sector, + struct bio_list *bios) +{ + struct bio_list tmp = BIO_EMPTY_LIST; + struct r5pending_data *ent; + + spin_lock(&conf->pending_bios_lock); + ent = list_first_entry(&conf->free_list, struct r5pending_data, + sibling); + list_move_tail(&ent->sibling, &conf->pending_list); + ent->sector = sector; + bio_list_init(&ent->bios); + bio_list_merge(&ent->bios, bios); + conf->pending_data_cnt++; + if (conf->pending_data_cnt >= PENDING_IO_MAX) + dispatch_defer_bios(conf, PENDING_IO_ONE_FLUSH, &tmp); + + spin_unlock(&conf->pending_bios_lock); + + dispatch_bio_list(&tmp); +} + +static void +raid5_end_read_request(struct bio *bi); +static void +raid5_end_write_request(struct bio *bi); + +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; + struct stripe_head *head_sh = sh; + struct bio_list pending_bios = BIO_EMPTY_LIST; + bool should_defer; + + might_sleep(); + + if (log_stripe(sh, s) == 0) + return; + + should_defer = conf->batch_bio_dispatch && conf->group_cnt; + + for (i = disks; i--; ) { + int op, op_flags = 0; + int replace_only = 0; + struct bio *bi, *rbi; + struct md_rdev *rdev, *rrdev = NULL; + + sh = head_sh; + if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) { + op = REQ_OP_WRITE; + if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags)) + op_flags = REQ_FUA; + if (test_bit(R5_Discard, &sh->dev[i].flags)) + op = REQ_OP_DISCARD; + } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) + op = REQ_OP_READ; + else if (test_and_clear_bit(R5_WantReplace, + &sh->dev[i].flags)) { + op = REQ_OP_WRITE; + replace_only = 1; + } else + continue; + if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags)) + op_flags |= REQ_SYNC; + +again: + bi = &sh->dev[i].req; + rbi = &sh->dev[i].rreq; /* For writing to replacement */ + + 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 (op_is_write(op)) { + if (replace_only) + rdev = NULL; + if (rdev == rrdev) + /* We raced and saw duplicates */ + rrdev = NULL; + } else { + if (test_bit(R5_ReadRepl, &head_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 (op_is_write(op) && 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->sb_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); + + bio_set_dev(bi, rdev->bdev); + bio_set_op_attrs(bi, op, op_flags); + bi->bi_end_io = op_is_write(op) + ? raid5_end_write_request + : raid5_end_read_request; + bi->bi_private = sh; + + pr_debug("%s: for %llu schedule op %d on disc %d\n", + __func__, (unsigned long long)sh->sector, + bi->bi_opf, i); + atomic_inc(&sh->count); + if (sh != head_sh) + atomic_inc(&head_sh->count); + if (use_new_offset(conf, sh)) + bi->bi_iter.bi_sector = (sh->sector + + rdev->new_data_offset); + else + bi->bi_iter.bi_sector = (sh->sector + + rdev->data_offset); + if (test_bit(R5_ReadNoMerge, &head_sh->dev[i].flags)) + bi->bi_opf |= REQ_NOMERGE; + + if (test_bit(R5_SkipCopy, &sh->dev[i].flags)) + WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags)); + + if (!op_is_write(op) && + test_bit(R5_InJournal, &sh->dev[i].flags)) + /* + * issuing read for a page in journal, this + * must be preparing for prexor in rmw; read + * the data into orig_page + */ + sh->dev[i].vec.bv_page = sh->dev[i].orig_page; + else + sh->dev[i].vec.bv_page = sh->dev[i].page; + bi->bi_vcnt = 1; + bi->bi_io_vec[0].bv_len = STRIPE_SIZE; + bi->bi_io_vec[0].bv_offset = 0; + bi->bi_iter.bi_size = STRIPE_SIZE; + bi->bi_write_hint = sh->dev[i].write_hint; + if (!rrdev) + sh->dev[i].write_hint = RWF_WRITE_LIFE_NOT_SET; + /* + * If this is discard request, set bi_vcnt 0. We don't + * want to confuse SCSI because SCSI will replace payload + */ + if (op == REQ_OP_DISCARD) + bi->bi_vcnt = 0; + if (rrdev) + set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags); + + if (conf->mddev->gendisk) + trace_block_bio_remap(bi->bi_disk->queue, + bi, disk_devt(conf->mddev->gendisk), + sh->dev[i].sector); + if (should_defer && op_is_write(op)) + bio_list_add(&pending_bios, bi); + else + 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); + + bio_set_dev(rbi, rrdev->bdev); + bio_set_op_attrs(rbi, op, op_flags); + BUG_ON(!op_is_write(op)); + rbi->bi_end_io = raid5_end_write_request; + rbi->bi_private = sh; + + pr_debug("%s: for %llu schedule op %d on " + "replacement disc %d\n", + __func__, (unsigned long long)sh->sector, + rbi->bi_opf, i); + atomic_inc(&sh->count); + if (sh != head_sh) + atomic_inc(&head_sh->count); + if (use_new_offset(conf, sh)) + rbi->bi_iter.bi_sector = (sh->sector + + rrdev->new_data_offset); + else + rbi->bi_iter.bi_sector = (sh->sector + + rrdev->data_offset); + if (test_bit(R5_SkipCopy, &sh->dev[i].flags)) + WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags)); + sh->dev[i].rvec.bv_page = sh->dev[i].page; + rbi->bi_vcnt = 1; + rbi->bi_io_vec[0].bv_len = STRIPE_SIZE; + rbi->bi_io_vec[0].bv_offset = 0; + rbi->bi_iter.bi_size = STRIPE_SIZE; + rbi->bi_write_hint = sh->dev[i].write_hint; + sh->dev[i].write_hint = RWF_WRITE_LIFE_NOT_SET; + /* + * If this is discard request, set bi_vcnt 0. We don't + * want to confuse SCSI because SCSI will replace payload + */ + if (op == REQ_OP_DISCARD) + rbi->bi_vcnt = 0; + if (conf->mddev->gendisk) + trace_block_bio_remap(rbi->bi_disk->queue, + rbi, disk_devt(conf->mddev->gendisk), + sh->dev[i].sector); + if (should_defer && op_is_write(op)) + bio_list_add(&pending_bios, rbi); + else + generic_make_request(rbi); + } + if (!rdev && !rrdev) { + if (op_is_write(op)) + set_bit(STRIPE_DEGRADED, &sh->state); + pr_debug("skip op %d on disc %d for sector %llu\n", + bi->bi_opf, i, (unsigned long long)sh->sector); + clear_bit(R5_LOCKED, &sh->dev[i].flags); + set_bit(STRIPE_HANDLE, &sh->state); + } + + if (!head_sh->batch_head) + continue; + sh = list_first_entry(&sh->batch_list, struct stripe_head, + batch_list); + if (sh != head_sh) + goto again; + } + + if (should_defer && !bio_list_empty(&pending_bios)) + defer_issue_bios(conf, head_sh->sector, &pending_bios); +} + +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 stripe_head *sh, int no_skipcopy) +{ + struct bio_vec bvl; + struct bvec_iter iter; + struct page *bio_page; + int page_offset; + struct async_submit_ctl submit; + enum async_tx_flags flags = 0; + + if (bio->bi_iter.bi_sector >= sector) + page_offset = (signed)(bio->bi_iter.bi_sector - sector) * 512; + else + page_offset = (signed)(sector - bio->bi_iter.bi_sector) * -512; + + if (frombio) + flags |= ASYNC_TX_FENCE; + init_async_submit(&submit, flags, tx, NULL, NULL, NULL); + + bio_for_each_segment(bvl, bio, iter) { + 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) { + if (sh->raid_conf->skip_copy && + b_offset == 0 && page_offset == 0 && + clen == STRIPE_SIZE && + !no_skipcopy) + *page = bio_page; + else + 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; + 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_iter.bi_sector < + dev->sector + STRIPE_SECTORS) { + rbi2 = r5_next_bio(rbi, dev->sector); + bio_endio(rbi); + rbi = rbi2; + } + } + } + clear_bit(STRIPE_BIOFILL_RUN, &sh->state); + + set_bit(STRIPE_HANDLE, &sh->state); + raid5_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; + + BUG_ON(sh->batch_head); + 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_iter.bi_sector < + dev->sector + STRIPE_SECTORS) { + tx = async_copy_data(0, rbi, &dev->page, + dev->sector, tx, sh, 0); + 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); + raid5_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, int i) +{ + void *addr; + + addr = flex_array_get(percpu->scribble, i); + return addr + sizeof(struct page *) * (sh->disks + 2); +} + +/* return a pointer to the address conversion region of the scribble buffer */ +static struct page **to_addr_page(struct raid5_percpu *percpu, int i) +{ + void *addr; + + addr = flex_array_get(percpu->scribble, i); + return addr; +} + +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 = to_addr_page(percpu, 0); + 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; + + BUG_ON(sh->batch_head); + + 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, 0)); + 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 srctype) +{ + 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); + struct r5dev *dev = &sh->dev[i]; + + if (i == sh->qd_idx || i == sh->pd_idx || + (srctype == SYNDROME_SRC_ALL) || + (srctype == SYNDROME_SRC_WANT_DRAIN && + (test_bit(R5_Wantdrain, &dev->flags) || + test_bit(R5_InJournal, &dev->flags))) || + (srctype == SYNDROME_SRC_WRITTEN && + (dev->written || + test_bit(R5_InJournal, &dev->flags)))) { + if (test_bit(R5_InJournal, &dev->flags)) + srcs[slot] = sh->dev[i].orig_page; + else + 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 = to_addr_page(percpu, 0); + 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; + + BUG_ON(sh->batch_head); + 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, SYNDROME_SRC_ALL); + 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, 0)); + 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, 0)); + 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 = to_addr_page(percpu, 0); + struct async_submit_ctl submit; + + BUG_ON(sh->batch_head); + 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, 0)); + 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, 0)); + tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, + &submit); + + count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_ALL); + init_async_submit(&submit, ASYNC_TX_FENCE, tx, + ops_complete_compute, sh, + to_addr_conv(sh, percpu, 0)); + 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, 0)); + 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); + + if (r5c_is_writeback(sh->raid_conf->log)) + /* + * raid5-cache write back uses orig_page during prexor. + * After prexor, it is time to free orig_page + */ + r5c_release_extra_page(sh); +} + +static struct dma_async_tx_descriptor * +ops_run_prexor5(struct stripe_head *sh, struct raid5_percpu *percpu, + struct dma_async_tx_descriptor *tx) +{ + int disks = sh->disks; + struct page **xor_srcs = to_addr_page(percpu, 0); + 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; + + BUG_ON(sh->batch_head); + 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_InJournal, &dev->flags)) + xor_srcs[count++] = dev->orig_page; + else 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, 0)); + tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); + + return tx; +} + +static struct dma_async_tx_descriptor * +ops_run_prexor6(struct stripe_head *sh, struct raid5_percpu *percpu, + struct dma_async_tx_descriptor *tx) +{ + struct page **blocks = to_addr_page(percpu, 0); + int count; + struct async_submit_ctl submit; + + pr_debug("%s: stripe %llu\n", __func__, + (unsigned long long)sh->sector); + + count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_WANT_DRAIN); + + init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_PQ_XOR_DST, tx, + ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0)); + tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); + + return tx; +} + +static struct dma_async_tx_descriptor * +ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) +{ + struct r5conf *conf = sh->raid_conf; + int disks = sh->disks; + int i; + struct stripe_head *head_sh = sh; + + pr_debug("%s: stripe %llu\n", __func__, + (unsigned long long)sh->sector); + + for (i = disks; i--; ) { + struct r5dev *dev; + struct bio *chosen; + + sh = head_sh; + if (test_and_clear_bit(R5_Wantdrain, &head_sh->dev[i].flags)) { + struct bio *wbi; + +again: + dev = &sh->dev[i]; + /* + * clear R5_InJournal, so when rewriting a page in + * journal, it is not skipped by r5l_log_stripe() + */ + clear_bit(R5_InJournal, &dev->flags); + spin_lock_irq(&sh->stripe_lock); + chosen = dev->towrite; + dev->towrite = NULL; + sh->overwrite_disks = 0; + BUG_ON(dev->written); + wbi = dev->written = chosen; + spin_unlock_irq(&sh->stripe_lock); + WARN_ON(dev->page != dev->orig_page); + + while (wbi && wbi->bi_iter.bi_sector < + dev->sector + STRIPE_SECTORS) { + if (wbi->bi_opf & REQ_FUA) + set_bit(R5_WantFUA, &dev->flags); + if (wbi->bi_opf & REQ_SYNC) + set_bit(R5_SyncIO, &dev->flags); + if (bio_op(wbi) == REQ_OP_DISCARD) + set_bit(R5_Discard, &dev->flags); + else { + tx = async_copy_data(1, wbi, &dev->page, + dev->sector, tx, sh, + r5c_is_writeback(conf->log)); + if (dev->page != dev->orig_page && + !r5c_is_writeback(conf->log)) { + set_bit(R5_SkipCopy, &dev->flags); + clear_bit(R5_UPTODATE, &dev->flags); + clear_bit(R5_OVERWRITE, &dev->flags); + } + } + wbi = r5_next_bio(wbi, dev->sector); + } + + if (head_sh->batch_head) { + sh = list_first_entry(&sh->batch_list, + struct stripe_head, + batch_list); + if (sh == head_sh) + continue; + goto again; + } + } + } + + 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, discard = 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); + discard |= test_bit(R5_Discard, &sh->dev[i].flags); + } + + for (i = disks; i--; ) { + struct r5dev *dev = &sh->dev[i]; + + if (dev->written || i == pd_idx || i == qd_idx) { + if (!discard && !test_bit(R5_SkipCopy, &dev->flags)) { + set_bit(R5_UPTODATE, &dev->flags); + if (test_bit(STRIPE_EXPAND_READY, &sh->state)) + set_bit(R5_Expanded, &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); + raid5_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; + struct async_submit_ctl submit; + int count, pd_idx = sh->pd_idx, i; + struct page *xor_dest; + int prexor = 0; + unsigned long flags; + int j = 0; + struct stripe_head *head_sh = sh; + int last_stripe; + + pr_debug("%s: stripe %llu\n", __func__, + (unsigned long long)sh->sector); + + for (i = 0; i < sh->disks; i++) { + if (pd_idx == i) + continue; + if (!test_bit(R5_Discard, &sh->dev[i].flags)) + break; + } + if (i >= sh->disks) { + atomic_inc(&sh->count); + set_bit(R5_Discard, &sh->dev[pd_idx].flags); + ops_complete_reconstruct(sh); + return; + } +again: + count = 0; + xor_srcs = to_addr_page(percpu, j); + /* check if prexor is active which means only process blocks + * that are part of a read-modify-write (written) + */ + if (head_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 (head_sh->dev[i].written || + test_bit(R5_InJournal, &head_sh->dev[i].flags)) + 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 + */ + last_stripe = !head_sh->batch_head || + list_first_entry(&sh->batch_list, + struct stripe_head, batch_list) == head_sh; + if (last_stripe) { + flags = ASYNC_TX_ACK | + (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); + + atomic_inc(&head_sh->count); + init_async_submit(&submit, flags, tx, ops_complete_reconstruct, head_sh, + to_addr_conv(sh, percpu, j)); + } else { + flags = prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST; + init_async_submit(&submit, flags, tx, NULL, NULL, + to_addr_conv(sh, percpu, j)); + } + + 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); + if (!last_stripe) { + j++; + sh = list_first_entry(&sh->batch_list, struct stripe_head, + batch_list); + goto again; + } +} + +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; + int count, i, j = 0; + struct stripe_head *head_sh = sh; + int last_stripe; + int synflags; + unsigned long txflags; + + pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); + + for (i = 0; i < sh->disks; i++) { + if (sh->pd_idx == i || sh->qd_idx == i) + continue; + if (!test_bit(R5_Discard, &sh->dev[i].flags)) + break; + } + if (i >= sh->disks) { + atomic_inc(&sh->count); + set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags); + set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags); + ops_complete_reconstruct(sh); + return; + } + +again: + blocks = to_addr_page(percpu, j); + + if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) { + synflags = SYNDROME_SRC_WRITTEN; + txflags = ASYNC_TX_ACK | ASYNC_TX_PQ_XOR_DST; + } else { + synflags = SYNDROME_SRC_ALL; + txflags = ASYNC_TX_ACK; + } + + count = set_syndrome_sources(blocks, sh, synflags); + last_stripe = !head_sh->batch_head || + list_first_entry(&sh->batch_list, + struct stripe_head, batch_list) == head_sh; + + if (last_stripe) { + atomic_inc(&head_sh->count); + init_async_submit(&submit, txflags, tx, ops_complete_reconstruct, + head_sh, to_addr_conv(sh, percpu, j)); + } else + init_async_submit(&submit, 0, tx, NULL, NULL, + to_addr_conv(sh, percpu, j)); + tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); + if (!last_stripe) { + j++; + sh = list_first_entry(&sh->batch_list, struct stripe_head, + batch_list); + goto again; + } +} + +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); + raid5_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 = to_addr_page(percpu, 0); + 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); + + BUG_ON(sh->batch_head); + 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, 0)); + 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 = to_addr_page(percpu, 0); + struct async_submit_ctl submit; + int count; + + pr_debug("%s: stripe %llu checkp: %d\n", __func__, + (unsigned long long)sh->sector, checkp); + + BUG_ON(sh->batch_head); + count = set_syndrome_sources(srcs, sh, SYNDROME_SRC_ALL); + 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, 0)); + 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)) { + if (level < 6) + tx = ops_run_prexor5(sh, percpu, tx); + else + tx = ops_run_prexor6(sh, percpu, tx); + } + + if (test_bit(STRIPE_OP_PARTIAL_PARITY, &ops_request)) + tx = ops_run_partial_parity(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 && !sh->batch_head) + 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(); +} + +static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh) +{ + if (sh->ppl_page) + __free_page(sh->ppl_page); + kmem_cache_free(sc, sh); +} + +static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp, + int disks, struct r5conf *conf) +{ + struct stripe_head *sh; + int i; + + sh = kmem_cache_zalloc(sc, gfp); + if (sh) { + spin_lock_init(&sh->stripe_lock); + spin_lock_init(&sh->batch_lock); + INIT_LIST_HEAD(&sh->batch_list); + INIT_LIST_HEAD(&sh->lru); + INIT_LIST_HEAD(&sh->r5c); + INIT_LIST_HEAD(&sh->log_list); + atomic_set(&sh->count, 1); + sh->raid_conf = conf; + sh->log_start = MaxSector; + for (i = 0; i < disks; i++) { + struct r5dev *dev = &sh->dev[i]; + + bio_init(&dev->req, &dev->vec, 1); + bio_init(&dev->rreq, &dev->rvec, 1); + } + + if (raid5_has_ppl(conf)) { + sh->ppl_page = alloc_page(gfp); + if (!sh->ppl_page) { + free_stripe(sc, sh); + sh = NULL; + } + } + } + return sh; +} +static int grow_one_stripe(struct r5conf *conf, gfp_t gfp) +{ + struct stripe_head *sh; + + sh = alloc_stripe(conf->slab_cache, gfp, conf->pool_size, conf); + if (!sh) + return 0; + + if (grow_buffers(sh, gfp)) { + shrink_buffers(sh); + free_stripe(conf->slab_cache, sh); + return 0; + } + sh->hash_lock_index = + conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS; + /* we just created an active stripe so... */ + atomic_inc(&conf->active_stripes); + + raid5_release_stripe(sh); + conf->max_nr_stripes++; + return 1; +} + +static int grow_stripes(struct r5conf *conf, int num) +{ + struct kmem_cache *sc; + size_t namelen = sizeof(conf->cache_name[0]); + int devs = max(conf->raid_disks, conf->previous_raid_disks); + + if (conf->mddev->gendisk) + snprintf(conf->cache_name[0], namelen, + "raid%d-%s", conf->level, mdname(conf->mddev)); + else + snprintf(conf->cache_name[0], namelen, + "raid%d-%p", conf->level, conf->mddev); + snprintf(conf->cache_name[1], namelen, "%.27s-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, GFP_KERNEL)) + 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 struct flex_array *scribble_alloc(int num, int cnt, gfp_t flags) +{ + struct flex_array *ret; + size_t len; + + len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2); + ret = flex_array_alloc(len, cnt, flags); + if (!ret) + return NULL; + /* always prealloc all elements, so no locking is required */ + if (flex_array_prealloc(ret, 0, cnt, flags)) { + flex_array_free(ret); + return NULL; + } + return ret; +} + +static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors) +{ + unsigned long cpu; + int err = 0; + + /* + * Never shrink. And mddev_suspend() could deadlock if this is called + * from raid5d. In that case, scribble_disks and scribble_sectors + * should equal to new_disks and new_sectors + */ + if (conf->scribble_disks >= new_disks && + conf->scribble_sectors >= new_sectors) + return 0; + mddev_suspend(conf->mddev); + get_online_cpus(); + for_each_present_cpu(cpu) { + struct raid5_percpu *percpu; + struct flex_array *scribble; + + percpu = per_cpu_ptr(conf->percpu, cpu); + scribble = scribble_alloc(new_disks, + new_sectors / STRIPE_SECTORS, + GFP_NOIO); + + if (scribble) { + flex_array_free(percpu->scribble); + percpu->scribble = scribble; + } else { + err = -ENOMEM; + break; + } + } + put_online_cpus(); + mddev_resume(conf->mddev); + if (!err) { + conf->scribble_disks = new_disks; + conf->scribble_sectors = new_sectors; + } + return err; +} + +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 transfer 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 failure status - no need to clean anything up. + * 4/ allocate new pages for the new slots in the new stripe_heads. + * If this fails, we don't bother trying the shrink the + * stripe_heads down again, we just leave them as they are. + * As each stripe_head is processed the new one is released into + * active service. + * + * Once step2 is started, we cannot afford to wait for a write, + * so we use GFP_NOIO allocations. + */ + struct stripe_head *osh, *nsh; + LIST_HEAD(newstripes); + struct disk_info *ndisks; + int err = 0; + struct kmem_cache *sc; + int i; + int hash, cnt; + + md_allow_write(conf->mddev); + + /* Step 1 */ + sc = kmem_cache_create(conf->cache_name[1-conf->active_name], + sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), + 0, 0, NULL); + if (!sc) + return -ENOMEM; + + /* Need to ensure auto-resizing doesn't interfere */ + mutex_lock(&conf->cache_size_mutex); + + for (i = conf->max_nr_stripes; i; i--) { + nsh = alloc_stripe(sc, GFP_KERNEL, newsize, conf); + if (!nsh) + break; + + 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); + free_stripe(sc, nsh); + } + kmem_cache_destroy(sc); + mutex_unlock(&conf->cache_size_mutex); + return -ENOMEM; + } + /* Step 2 - Must use GFP_NOIO now. + * OK, we have enough stripes, start collecting inactive + * stripes and copying them over + */ + hash = 0; + cnt = 0; + list_for_each_entry(nsh, &newstripes, lru) { + lock_device_hash_lock(conf, hash); + wait_event_cmd(conf->wait_for_stripe, + !list_empty(conf->inactive_list + hash), + unlock_device_hash_lock(conf, hash), + lock_device_hash_lock(conf, hash)); + osh = get_free_stripe(conf, hash); + unlock_device_hash_lock(conf, hash); + + for(i=0; i<conf->pool_size; i++) { + nsh->dev[i].page = osh->dev[i].page; + nsh->dev[i].orig_page = osh->dev[i].page; + } + nsh->hash_lock_index = hash; + free_stripe(conf->slab_cache, osh); + cnt++; + if (cnt >= conf->max_nr_stripes / NR_STRIPE_HASH_LOCKS + + !!((conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS) > hash)) { + hash++; + cnt = 0; + } + } + 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 = kcalloc(newsize, sizeof(struct disk_info), GFP_NOIO); + if (ndisks) { + for (i = 0; i < conf->pool_size; i++) + ndisks[i] = conf->disks[i]; + + for (i = conf->pool_size; i < newsize; i++) { + ndisks[i].extra_page = alloc_page(GFP_NOIO); + if (!ndisks[i].extra_page) + err = -ENOMEM; + } + + if (err) { + for (i = conf->pool_size; i < newsize; i++) + if (ndisks[i].extra_page) + put_page(ndisks[i].extra_page); + kfree(ndisks); + } else { + kfree(conf->disks); + conf->disks = ndisks; + } + } else + err = -ENOMEM; + + conf->slab_cache = sc; + conf->active_name = 1-conf->active_name; + + /* 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; + nsh->dev[i].orig_page = p; + if (!p) + err = -ENOMEM; + } + raid5_release_stripe(nsh); + } + /* critical section pass, GFP_NOIO no longer needed */ + + if (!err) + conf->pool_size = newsize; + mutex_unlock(&conf->cache_size_mutex); + + return err; +} + +static int drop_one_stripe(struct r5conf *conf) +{ + struct stripe_head *sh; + int hash = (conf->max_nr_stripes - 1) & STRIPE_HASH_LOCKS_MASK; + + spin_lock_irq(conf->hash_locks + hash); + sh = get_free_stripe(conf, hash); + spin_unlock_irq(conf->hash_locks + hash); + if (!sh) + return 0; + BUG_ON(atomic_read(&sh->count)); + shrink_buffers(sh); + free_stripe(conf->slab_cache, sh); + atomic_dec(&conf->active_stripes); + conf->max_nr_stripes--; + return 1; +} + +static void shrink_stripes(struct r5conf *conf) +{ + while (conf->max_nr_stripes && + drop_one_stripe(conf)) + ; + + kmem_cache_destroy(conf->slab_cache); + conf->slab_cache = NULL; +} + +static void raid5_end_read_request(struct bio * bi) +{ + struct stripe_head *sh = bi->bi_private; + struct r5conf *conf = sh->raid_conf; + int disks = sh->disks, i; + 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, error %d.\n", + (unsigned long long)sh->sector, i, atomic_read(&sh->count), + bi->bi_status); + if (i == disks) { + bio_reset(bi); + 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 (!bi->bi_status) { + 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 + */ + pr_info_ratelimited( + "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 (test_bit(R5_InJournal, &sh->dev[i].flags)) + /* + * end read for a page in journal, this + * must be preparing for prexor in rmw + */ + set_bit(R5_OrigPageUPTDODATE, &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); + if (!(bi->bi_status == BLK_STS_PROTECTION)) + atomic_inc(&rdev->read_errors); + if (test_bit(R5_ReadRepl, &sh->dev[i].flags)) + pr_warn_ratelimited( + "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; + pr_warn_ratelimited( + "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; + pr_warn_ratelimited( + "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) + pr_warn("md/raid:%s: Too many read errors, failing device %s.\n", + mdname(conf->mddev), bdn); + else + retry = 1; + if (set_bad && test_bit(In_sync, &rdev->flags) + && !test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) + retry = 1; + if (retry) + if (sh->qd_idx >= 0 && sh->pd_idx == i) + set_bit(R5_ReadError, &sh->dev[i].flags); + else 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); + bio_reset(bi); + clear_bit(R5_LOCKED, &sh->dev[i].flags); + set_bit(STRIPE_HANDLE, &sh->state); + raid5_release_stripe(sh); +} + +static void raid5_end_write_request(struct bio *bi) +{ + struct stripe_head *sh = bi->bi_private; + struct r5conf *conf = sh->raid_conf; + int disks = sh->disks, i; + struct md_rdev *uninitialized_var(rdev); + 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, error: %d.\n", + (unsigned long long)sh->sector, i, atomic_read(&sh->count), + bi->bi_status); + if (i == disks) { + bio_reset(bi); + BUG(); + return; + } + + if (replacement) { + if (bi->bi_status) + 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 (bi->bi_status) { + set_bit(STRIPE_DEGRADED, &sh->state); + 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); + if (test_bit(R5_ReadError, &sh->dev[i].flags)) + /* That was a successful write so make + * sure it looks like we already did + * a re-write. + */ + set_bit(R5_ReWrite, &sh->dev[i].flags); + } + } + rdev_dec_pending(rdev, conf->mddev); + + if (sh->batch_head && bi->bi_status && !replacement) + set_bit(STRIPE_BATCH_ERR, &sh->batch_head->state); + + bio_reset(bi); + 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); + raid5_release_stripe(sh); + + if (sh->batch_head && sh != sh->batch_head) + raid5_release_stripe(sh->batch_head); +} + +static void raid5_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); + set_bit(Faulty, &rdev->flags); + clear_bit(In_sync, &rdev->flags); + mddev->degraded = raid5_calc_degraded(conf); + spin_unlock_irqrestore(&conf->device_lock, flags); + set_bit(MD_RECOVERY_INTR, &mddev->recovery); + + set_bit(Blocked, &rdev->flags); + set_mask_bits(&mddev->sb_flags, 0, + BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); + pr_crit("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); + r5c_update_on_rdev_error(mddev, rdev); +} + +/* + * Input: a 'big' sector number, + * Output: index of the data and parity disk, and the sector # in them. + */ +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; +} + +sector_t raid5_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) { + pr_warn("md/raid:%s: compute_blocknr: map not correct\n", + mdname(conf->mddev)); + return 0; + } + return r_sector; +} + +/* + * There are cases where we want handle_stripe_dirtying() and + * schedule_reconstruction() to delay towrite to some dev of a stripe. + * + * This function checks whether we want to delay the towrite. Specifically, + * we delay the towrite when: + * + * 1. degraded stripe has a non-overwrite to the missing dev, AND this + * stripe has data in journal (for other devices). + * + * In this case, when reading data for the non-overwrite dev, it is + * necessary to handle complex rmw of write back cache (prexor with + * orig_page, and xor with page). To keep read path simple, we would + * like to flush data in journal to RAID disks first, so complex rmw + * is handled in the write patch (handle_stripe_dirtying). + * + * 2. when journal space is critical (R5C_LOG_CRITICAL=1) + * + * It is important to be able to flush all stripes in raid5-cache. + * Therefore, we need reserve some space on the journal device for + * these flushes. If flush operation includes pending writes to the + * stripe, we need to reserve (conf->raid_disk + 1) pages per stripe + * for the flush out. If we exclude these pending writes from flush + * operation, we only need (conf->max_degraded + 1) pages per stripe. + * Therefore, excluding pending writes in these cases enables more + * efficient use of the journal device. + * + * Note: To make sure the stripe makes progress, we only delay + * towrite for stripes with data already in journal (injournal > 0). + * When LOG_CRITICAL, stripes with injournal == 0 will be sent to + * no_space_stripes list. + * + * 3. during journal failure + * In journal failure, we try to flush all cached data to raid disks + * based on data in stripe cache. The array is read-only to upper + * layers, so we would skip all pending writes. + * + */ +static inline bool delay_towrite(struct r5conf *conf, + struct r5dev *dev, + struct stripe_head_state *s) +{ + /* case 1 above */ + if (!test_bit(R5_OVERWRITE, &dev->flags) && + !test_bit(R5_Insync, &dev->flags) && s->injournal) + return true; + /* case 2 above */ + if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) && + s->injournal > 0) + return true; + /* case 3 above */ + if (s->log_failed && s->injournal) + return true; + return false; +} + +static void +schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, + int rcw, int expand) +{ + int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx, disks = sh->disks; + struct r5conf *conf = sh->raid_conf; + int level = conf->level; + + if (rcw) { + /* + * In some cases, handle_stripe_dirtying initially decided to + * run rmw and allocates extra page for prexor. However, rcw is + * cheaper later on. We need to free the extra page now, + * because we won't be able to do that in ops_complete_prexor(). + */ + r5c_release_extra_page(sh); + + for (i = disks; i--; ) { + struct r5dev *dev = &sh->dev[i]; + + if (dev->towrite && !delay_towrite(conf, dev, s)) { + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantdrain, &dev->flags); + if (!expand) + clear_bit(R5_UPTODATE, &dev->flags); + s->locked++; + } else if (test_bit(R5_InJournal, &dev->flags)) { + set_bit(R5_LOCKED, &dev->flags); + s->locked++; + } + } + /* 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) { + if (!s->locked) + /* False alarm, nothing to do */ + return; + 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); + + 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(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || + test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); + BUG_ON(level == 6 && + (!(test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags) || + test_bit(R5_Wantcompute, &sh->dev[qd_idx].flags)))); + + for (i = disks; i--; ) { + struct r5dev *dev = &sh->dev[i]; + if (i == pd_idx || i == qd_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++; + } else if (test_bit(R5_InJournal, &dev->flags)) { + set_bit(R5_LOCKED, &dev->flags); + s->locked++; + } + } + if (!s->locked) + /* False alarm - nothing to do */ + return; + 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); + } + + /* 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++; + } + + if (raid5_has_ppl(sh->raid_conf) && sh->ppl_page && + test_bit(STRIPE_OP_BIODRAIN, &s->ops_request) && + !test_bit(STRIPE_FULL_WRITE, &sh->state) && + test_bit(R5_Insync, &sh->dev[pd_idx].flags)) + set_bit(STRIPE_OP_PARTIAL_PARITY, &s->ops_request); + + 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, int previous) +{ + 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_iter.bi_sector, + (unsigned long long)sh->sector); + + spin_lock_irq(&sh->stripe_lock); + sh->dev[dd_idx].write_hint = bi->bi_write_hint; + /* Don't allow new IO added to stripes in batch list */ + if (sh->batch_head) + goto overlap; + if (forwrite) { + bip = &sh->dev[dd_idx].towrite; + if (*bip == NULL) + firstwrite = 1; + } else + bip = &sh->dev[dd_idx].toread; + while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector) { + if (bio_end_sector(*bip) > bi->bi_iter.bi_sector) + goto overlap; + bip = & (*bip)->bi_next; + } + if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi)) + goto overlap; + + if (forwrite && raid5_has_ppl(conf)) { + /* + * With PPL only writes to consecutive data chunks within a + * stripe are allowed because for a single stripe_head we can + * only have one PPL entry at a time, which describes one data + * range. Not really an overlap, but wait_for_overlap can be + * used to handle this. + */ + sector_t sector; + sector_t first = 0; + sector_t last = 0; + int count = 0; + int i; + + for (i = 0; i < sh->disks; i++) { + if (i != sh->pd_idx && + (i == dd_idx || sh->dev[i].towrite)) { + sector = sh->dev[i].sector; + if (count == 0 || sector < first) + first = sector; + if (sector > last) + last = sector; + count++; + } + } + + if (first + conf->chunk_sectors * (count - 1) != last) + goto overlap; + } + + if (!forwrite || previous) + clear_bit(STRIPE_BATCH_READY, &sh->state); + + BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); + if (*bip) + bi->bi_next = *bip; + *bip = bi; + bio_inc_remaining(bi); + md_write_inc(conf->mddev, 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_iter.bi_sector <= sector; + bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { + if (bio_end_sector(bi) >= sector) + sector = bio_end_sector(bi); + } + if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) + if (!test_and_set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags)) + sh->overwrite_disks++; + } + + pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", + (unsigned long long)(*bip)->bi_iter.bi_sector, + (unsigned long long)sh->sector, dd_idx); + + if (conf->mddev->bitmap && firstwrite) { + /* Cannot hold spinlock over bitmap_startwrite, + * but must ensure this isn't added to a batch until + * we have added to the bitmap and set bm_seq. + * So set STRIPE_BITMAP_PENDING to prevent + * batching. + * If multiple add_stripe_bio() calls race here they + * much all set STRIPE_BITMAP_PENDING. So only the first one + * to complete "bitmap_startwrite" gets to set + * STRIPE_BIT_DELAY. This is important as once a stripe + * is added to a batch, STRIPE_BIT_DELAY cannot be changed + * any more. + */ + set_bit(STRIPE_BITMAP_PENDING, &sh->state); + spin_unlock_irq(&sh->stripe_lock); + md_bitmap_startwrite(conf->mddev->bitmap, sh->sector, + STRIPE_SECTORS, 0); + spin_lock_irq(&sh->stripe_lock); + clear_bit(STRIPE_BITMAP_PENDING, &sh->state); + if (!sh->batch_head) { + sh->bm_seq = conf->seq_flush+1; + set_bit(STRIPE_BIT_DELAY, &sh->state); + } + } + spin_unlock_irq(&sh->stripe_lock); + + if (stripe_can_batch(sh)) + stripe_add_to_batch_list(conf, sh); + 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) +{ + int i; + BUG_ON(sh->batch_head); + 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) && + !test_bit(Faulty, &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; + sh->overwrite_disks = 0; + spin_unlock_irq(&sh->stripe_lock); + if (bi) + bitmap_end = 1; + + log_stripe_write_finished(sh); + + if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) + wake_up(&conf->wait_for_overlap); + + while (bi && bi->bi_iter.bi_sector < + sh->dev[i].sector + STRIPE_SECTORS) { + struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); + + md_write_end(conf->mddev); + bio_io_error(bi); + bi = nextbi; + } + if (bitmap_end) + md_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 (test_and_clear_bit(R5_SkipCopy, &sh->dev[i].flags)) { + WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags)); + sh->dev[i].page = sh->dev[i].orig_page; + } + + if (bi) bitmap_end = 1; + while (bi && bi->bi_iter.bi_sector < + sh->dev[i].sector + STRIPE_SECTORS) { + struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); + + md_write_end(conf->mddev); + bio_io_error(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) && + s->failed > conf->max_degraded && + (!test_bit(R5_Insync, &sh->dev[i].flags) || + test_bit(R5_ReadError, &sh->dev[i].flags))) { + spin_lock_irq(&sh->stripe_lock); + bi = sh->dev[i].toread; + sh->dev[i].toread = NULL; + spin_unlock_irq(&sh->stripe_lock); + 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_iter.bi_sector < + sh->dev[i].sector + STRIPE_SECTORS) { + struct bio *nextbi = + r5_next_bio(bi, sh->dev[i].sector); + + bio_io_error(bi); + bi = nextbi; + } + } + if (bitmap_end) + md_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); + } + s->to_write = 0; + s->written = 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_failed_sync(struct r5conf *conf, struct stripe_head *sh, + struct stripe_head_state *s) +{ + int abort = 0; + int i; + + BUG_ON(sh->batch_head); + clear_bit(STRIPE_SYNCING, &sh->state); + if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags)) + wake_up(&conf->wait_for_overlap); + 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 + */ + rcu_read_lock(); + 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) + && !test_bit(In_sync, &rdev->flags) + && !rdev_set_badblocks(rdev, sh->sector, + STRIPE_SECTORS, 0)) + abort = 1; + rdev = rcu_dereference(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; + } + rcu_read_unlock(); + 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; + + rcu_read_lock(); + rdev = rcu_dereference(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; + rcu_read_unlock(); + return rv; +} + +static int need_this_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]] }; + int i; + + + if (test_bit(R5_LOCKED, &dev->flags) || + test_bit(R5_UPTODATE, &dev->flags)) + /* No point reading this as we already have it or have + * decided to get it. + */ + return 0; + + if (dev->toread || + (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags))) + /* We need this block to directly satisfy a request */ + return 1; + + if (s->syncing || s->expanding || + (s->replacing && want_replace(sh, disk_idx))) + /* When syncing, or expanding we read everything. + * When replacing, we need the replaced block. + */ + return 1; + + if ((s->failed >= 1 && fdev[0]->toread) || + (s->failed >= 2 && fdev[1]->toread)) + /* If we want to read from a failed device, then + * we need to actually read every other device. + */ + return 1; + + /* Sometimes neither read-modify-write nor reconstruct-write + * cycles can work. In those cases we read every block we + * can. Then the parity-update is certain to have enough to + * work with. + * This can only be a problem when we need to write something, + * and some device has failed. If either of those tests + * fail we need look no further. + */ + if (!s->failed || !s->to_write) + return 0; + + if (test_bit(R5_Insync, &dev->flags) && + !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + /* Pre-reads at not permitted until after short delay + * to gather multiple requests. However if this + * device is no Insync, the block could only be computed + * and there is no need to delay that. + */ + return 0; + + for (i = 0; i < s->failed && i < 2; i++) { + if (fdev[i]->towrite && + !test_bit(R5_UPTODATE, &fdev[i]->flags) && + !test_bit(R5_OVERWRITE, &fdev[i]->flags)) + /* If we have a partial write to a failed + * device, then we will need to reconstruct + * the content of that device, so all other + * devices must be read. + */ + return 1; + } + + /* If we are forced to do a reconstruct-write, either because + * the current RAID6 implementation only supports that, or + * because parity cannot be trusted and we are currently + * recovering it, there is extra need to be careful. + * If one of the devices that we would need to read, because + * it is not being overwritten (and maybe not written at all) + * is missing/faulty, then we need to read everything we can. + */ + if (sh->raid_conf->level != 6 && + sh->raid_conf->rmw_level != PARITY_DISABLE_RMW && + sh->sector < sh->raid_conf->mddev->recovery_cp) + /* reconstruct-write isn't being forced */ + return 0; + for (i = 0; i < s->failed && i < 2; i++) { + if (s->failed_num[i] != sh->pd_idx && + s->failed_num[i] != sh->qd_idx && + !test_bit(R5_UPTODATE, &fdev[i]->flags) && + !test_bit(R5_OVERWRITE, &fdev[i]->flags)) + return 1; + } + + return 0; +} + +/* 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]; + + /* is the data in this block needed, and can we get it? */ + if (need_this_block(sh, s, disk_idx, disks)) { + /* 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)); + BUG_ON(sh->batch_head); + + /* + * In the raid6 case if the only non-uptodate disk is P + * then we already trusted P to compute the other failed + * drives. It is safe to compute rather than re-read P. + * In other cases we only compute blocks from failed + * devices, otherwise check/repair might fail to detect + * a real inconsistency. + */ + + if ((s->uptodate == disks - 1) && + ((sh->qd_idx >= 0 && sh->pd_idx == disk_idx) || + (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 degraded stripe with data in journal, do not handle + * read requests yet, instead, flush the stripe to raid + * disks first, this avoids handling complex rmw of write + * back cache (prexor with orig_page, and then xor with + * page) in the read path + */ + if (s->injournal && s->failed) { + if (test_bit(STRIPE_R5C_CACHING, &sh->state)) + r5c_make_stripe_write_out(sh); + goto out; + } + + for (i = disks; i--; ) + if (fetch_block(sh, s, i, disks)) + break; + } +out: + set_bit(STRIPE_HANDLE, &sh->state); +} + +static void break_stripe_batch_list(struct stripe_head *head_sh, + unsigned long handle_flags); +/* 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) +{ + int i; + struct r5dev *dev; + int discard_pending = 0; + struct stripe_head *head_sh = sh; + bool do_endio = false; + + 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) || + test_bit(R5_Discard, &dev->flags) || + test_bit(R5_SkipCopy, &dev->flags))) { + /* We can return any write requests */ + struct bio *wbi, *wbi2; + pr_debug("Return write for disc %d\n", i); + if (test_and_clear_bit(R5_Discard, &dev->flags)) + clear_bit(R5_UPTODATE, &dev->flags); + if (test_and_clear_bit(R5_SkipCopy, &dev->flags)) { + WARN_ON(test_bit(R5_UPTODATE, &dev->flags)); + } + do_endio = true; + +returnbi: + dev->page = dev->orig_page; + wbi = dev->written; + dev->written = NULL; + while (wbi && wbi->bi_iter.bi_sector < + dev->sector + STRIPE_SECTORS) { + wbi2 = r5_next_bio(wbi, dev->sector); + md_write_end(conf->mddev); + bio_endio(wbi); + wbi = wbi2; + } + md_bitmap_endwrite(conf->mddev->bitmap, sh->sector, + STRIPE_SECTORS, + !test_bit(STRIPE_DEGRADED, &sh->state), + 0); + if (head_sh->batch_head) { + sh = list_first_entry(&sh->batch_list, + struct stripe_head, + batch_list); + if (sh != head_sh) { + dev = &sh->dev[i]; + goto returnbi; + } + } + sh = head_sh; + dev = &sh->dev[i]; + } else if (test_bit(R5_Discard, &dev->flags)) + discard_pending = 1; + } + + log_stripe_write_finished(sh); + + if (!discard_pending && + test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) { + int hash; + clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags); + clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags); + if (sh->qd_idx >= 0) { + clear_bit(R5_Discard, &sh->dev[sh->qd_idx].flags); + clear_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags); + } + /* now that discard is done we can proceed with any sync */ + clear_bit(STRIPE_DISCARD, &sh->state); + /* + * SCSI discard will change some bio fields and the stripe has + * no updated data, so remove it from hash list and the stripe + * will be reinitialized + */ +unhash: + hash = sh->hash_lock_index; + spin_lock_irq(conf->hash_locks + hash); + remove_hash(sh); + spin_unlock_irq(conf->hash_locks + hash); + if (head_sh->batch_head) { + sh = list_first_entry(&sh->batch_list, + struct stripe_head, batch_list); + if (sh != head_sh) + goto unhash; + } + sh = head_sh; + + if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state)) + set_bit(STRIPE_HANDLE, &sh->state); + + } + + 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); + + if (head_sh->batch_head && do_endio) + break_stripe_batch_list(head_sh, STRIPE_EXPAND_SYNC_FLAGS); +} + +/* + * For RMW in write back cache, we need extra page in prexor to store the + * old data. This page is stored in dev->orig_page. + * + * This function checks whether we have data for prexor. The exact logic + * is: + * R5_UPTODATE && (!R5_InJournal || R5_OrigPageUPTDODATE) + */ +static inline bool uptodate_for_rmw(struct r5dev *dev) +{ + return (test_bit(R5_UPTODATE, &dev->flags)) && + (!test_bit(R5_InJournal, &dev->flags) || + test_bit(R5_OrigPageUPTDODATE, &dev->flags)); +} + +static int handle_stripe_dirtying(struct r5conf *conf, + struct stripe_head *sh, + struct stripe_head_state *s, + int disks) +{ + int rmw = 0, rcw = 0, i; + sector_t recovery_cp = conf->mddev->recovery_cp; + + /* Check whether resync is now happening or should start. + * If yes, then the array is dirty (after unclean shutdown or + * initial creation), so parity in some stripes might be inconsistent. + * In this case, we need to always do reconstruct-write, to ensure + * that in case of drive failure or read-error correction, we + * generate correct data from the parity. + */ + if (conf->rmw_level == PARITY_DISABLE_RMW || + (recovery_cp < MaxSector && sh->sector >= recovery_cp && + s->failed == 0)) { + /* Calculate the real rcw later - for now make it + * look like rcw is cheaper + */ + rcw = 1; rmw = 2; + pr_debug("force RCW rmw_level=%u, recovery_cp=%llu sh->sector=%llu\n", + conf->rmw_level, (unsigned long long)recovery_cp, + (unsigned long long)sh->sector); + } 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 && !delay_towrite(conf, dev, s)) || + i == sh->pd_idx || i == sh->qd_idx || + test_bit(R5_InJournal, &dev->flags)) && + !test_bit(R5_LOCKED, &dev->flags) && + !(uptodate_for_rmw(dev) || + 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 && i != sh->qd_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 state 0x%lx, rmw=%d rcw=%d\n", + (unsigned long long)sh->sector, sh->state, rmw, rcw); + set_bit(STRIPE_HANDLE, &sh->state); + if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_PREFER_RMW)) && rmw > 0) { + /* prefer read-modify-write, but need to get some data */ + if (conf->mddev->queue) + blk_add_trace_msg(conf->mddev->queue, + "raid5 rmw %llu %d", + (unsigned long long)sh->sector, rmw); + for (i = disks; i--; ) { + struct r5dev *dev = &sh->dev[i]; + if (test_bit(R5_InJournal, &dev->flags) && + dev->page == dev->orig_page && + !test_bit(R5_LOCKED, &sh->dev[sh->pd_idx].flags)) { + /* alloc page for prexor */ + struct page *p = alloc_page(GFP_NOIO); + + if (p) { + dev->orig_page = p; + continue; + } + + /* + * alloc_page() failed, try use + * disk_info->extra_page + */ + if (!test_and_set_bit(R5C_EXTRA_PAGE_IN_USE, + &conf->cache_state)) { + r5c_use_extra_page(sh); + break; + } + + /* extra_page in use, add to delayed_list */ + set_bit(STRIPE_DELAYED, &sh->state); + s->waiting_extra_page = 1; + return -EAGAIN; + } + } + + for (i = disks; i--; ) { + struct r5dev *dev = &sh->dev[i]; + if (((dev->towrite && !delay_towrite(conf, dev, s)) || + i == sh->pd_idx || i == sh->qd_idx || + test_bit(R5_InJournal, &dev->flags)) && + !test_bit(R5_LOCKED, &dev->flags) && + !(uptodate_for_rmw(dev) || + 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 == rmw && conf->rmw_level != PARITY_PREFER_RMW)) && rcw > 0) { + /* want reconstruct write, but need to get some data */ + int qread =0; + 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(R5_Wantcompute, &dev->flags))) { + rcw++; + if (test_bit(R5_Insync, &dev->flags) && + 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++; + qread++; + } else { + set_bit(STRIPE_DELAYED, &sh->state); + set_bit(STRIPE_HANDLE, &sh->state); + } + } + } + if (rcw && conf->mddev->queue) + blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d", + (unsigned long long)sh->sector, + rcw, qread, test_bit(STRIPE_DELAYED, &sh->state)); + } + + if (rcw > disks && rmw > disks && + !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + set_bit(STRIPE_DELAYED, &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. raid_run_ops only + * handles the case where compute block and reconstruct 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_reconstruction(sh, s, rcw == 0, 0); + return 0; +} + +static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh, + struct stripe_head_state *s, int disks) +{ + struct r5dev *dev = NULL; + + BUG_ON(sh->batch_head); + 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[0]]; + /* 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 & SUM_CHECK_P_RESULT) == 0) + /* parity is correct (on disc, + * not in buffer any more) + */ + set_bit(STRIPE_INSYNC, &sh->state); + else { + atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches); + if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) { + /* don't try to repair!! */ + set_bit(STRIPE_INSYNC, &sh->state); + pr_warn_ratelimited("%s: mismatch sector in range " + "%llu-%llu\n", mdname(conf->mddev), + (unsigned long long) sh->sector, + (unsigned long long) sh->sector + + STRIPE_SECTORS); + } 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; + sh->ops.target2 = -1; + s->uptodate++; + } + } + break; + case check_state_compute_run: + break; + default: + pr_err("%s: unknown check_state: %d sector: %llu\n", + __func__, sh->check_state, + (unsigned long long) sh->sector); + BUG(); + } +} + +static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh, + struct stripe_head_state *s, + int disks) +{ + int pd_idx = sh->pd_idx; + int qd_idx = sh->qd_idx; + struct r5dev *dev; + + BUG_ON(sh->batch_head); + set_bit(STRIPE_HANDLE, &sh->state); + + BUG_ON(s->failed > 2); + + /* 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 + */ + + switch (sh->check_state) { + case check_state_idle: + /* start a new check operation if there are < 2 failures */ + if (s->failed == s->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). + */ + sh->check_state = check_state_run; + } + if (!s->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 + */ + if (sh->check_state == check_state_run) + sh->check_state = check_state_run_pq; + else + sh->check_state = check_state_run_q; + } + + /* discard potentially stale zero_sum_result */ + sh->ops.zero_sum_result = 0; + + if (sh->check_state == check_state_run) { + /* async_xor_zero_sum destroys the contents of P */ + clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); + s->uptodate--; + } + if (sh->check_state >= check_state_run && + sh->check_state <= check_state_run_pq) { + /* async_syndrome_zero_sum preserves P and Q, so + * no need to mark them !uptodate here + */ + set_bit(STRIPE_OP_CHECK, &s->ops_request); + break; + } + + /* we have 2-disk failure */ + BUG_ON(s->failed != 2); + /* fall through */ + case check_state_compute_result: + sh->check_state = check_state_idle; + + /* check that a write has not made the stripe insync */ + if (test_bit(STRIPE_INSYNC, &sh->state)) + break; + + /* now write out any block on a failed drive, + * or P or Q if they were recomputed + */ + dev = NULL; + if (s->failed == 2) { + dev = &sh->dev[s->failed_num[1]]; + s->locked++; + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantwrite, &dev->flags); + } + if (s->failed >= 1) { + dev = &sh->dev[s->failed_num[0]]; + s->locked++; + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantwrite, &dev->flags); + } + if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { + dev = &sh->dev[pd_idx]; + s->locked++; + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantwrite, &dev->flags); + } + if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { + dev = &sh->dev[qd_idx]; + s->locked++; + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantwrite, &dev->flags); + } + if (WARN_ONCE(dev && !test_bit(R5_UPTODATE, &dev->flags), + "%s: disk%td not up to date\n", + mdname(conf->mddev), + dev - (struct r5dev *) &sh->dev)) { + clear_bit(R5_LOCKED, &dev->flags); + clear_bit(R5_Wantwrite, &dev->flags); + s->locked--; + } + clear_bit(STRIPE_DEGRADED, &sh->state); + + set_bit(STRIPE_INSYNC, &sh->state); + break; + case check_state_run: + case check_state_run_q: + case check_state_run_pq: + break; /* we will be called again upon completion */ + case check_state_check_result: + sh->check_state = check_state_idle; + + /* 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) { + /* both parities are correct */ + if (!s->failed) + set_bit(STRIPE_INSYNC, &sh->state); + else { + /* in contrast to the raid5 case we can validate + * parity, but still have a failure to write + * back + */ + sh->check_state = check_state_compute_result; + /* Returning at this point means that we may go + * off and bring p and/or q uptodate again so + * we make sure to check zero_sum_result again + * to verify if p or q need writeback + */ + } + } else { + atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches); + if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) { + /* don't try to repair!! */ + set_bit(STRIPE_INSYNC, &sh->state); + pr_warn_ratelimited("%s: mismatch sector in range " + "%llu-%llu\n", mdname(conf->mddev), + (unsigned long long) sh->sector, + (unsigned long long) sh->sector + + STRIPE_SECTORS); + } else { + int *target = &sh->ops.target; + + sh->ops.target = -1; + sh->ops.target2 = -1; + sh->check_state = check_state_compute_run; + set_bit(STRIPE_COMPUTE_RUN, &sh->state); + set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); + if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { + set_bit(R5_Wantcompute, + &sh->dev[pd_idx].flags); + *target = pd_idx; + target = &sh->ops.target2; + s->uptodate++; + } + if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { + set_bit(R5_Wantcompute, + &sh->dev[qd_idx].flags); + *target = qd_idx; + s->uptodate++; + } + } + } + break; + case check_state_compute_run: + break; + default: + pr_warn("%s: unknown check_state: %d sector: %llu\n", + __func__, sh->check_state, + (unsigned long long) sh->sector); + BUG(); + } +} + +static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh) +{ + 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; + BUG_ON(sh->batch_head); + clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); + for (i = 0; i < sh->disks; i++) + if (i != sh->pd_idx && i != sh->qd_idx) { + int dd_idx, j; + struct stripe_head *sh2; + struct async_submit_ctl submit; + + sector_t bn = raid5_compute_blocknr(sh, i, 1); + sector_t s = raid5_compute_sector(conf, bn, 0, + &dd_idx, NULL); + sh2 = raid5_get_active_stripe(conf, s, 0, 1, 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 */ + raid5_release_stripe(sh2); + continue; + } + + /* place all the copies on one channel */ + init_async_submit(&submit, 0, tx, NULL, NULL, NULL); + tx = async_memcpy(sh2->dev[dd_idx].page, + sh->dev[i].page, 0, 0, STRIPE_SIZE, + &submit); + + 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 && + j != sh2->qd_idx && + !test_bit(R5_Expanded, &sh2->dev[j].flags)) + break; + if (j == conf->raid_disks) { + set_bit(STRIPE_EXPAND_READY, &sh2->state); + set_bit(STRIPE_HANDLE, &sh2->state); + } + raid5_release_stripe(sh2); + + } + /* done submitting copies, wait for them to complete */ + async_tx_quiesce(&tx); +} + +/* + * handle_stripe - do things to a stripe. + * + * We lock the stripe by setting STRIPE_ACTIVE and then examine the + * state of various bits to see what needs to be done. + * Possible results: + * return some read requests which now have data + * return some write requests which are safely on storage + * schedule a read on some buffers + * schedule a write of some buffers + * return confirmation of parity correctness + * + */ + +static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s) +{ + struct r5conf *conf = sh->raid_conf; + int disks = sh->disks; + struct r5dev *dev; + int i; + int do_recovery = 0; + + memset(s, 0, sizeof(*s)); + + s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state) && !sh->batch_head; + s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state) && !sh->batch_head; + s->failed_num[0] = -1; + s->failed_num[1] = -1; + s->log_failed = r5l_log_disk_error(conf); + + /* Now to look around and see what can be done */ + rcu_read_lock(); + for (i=disks; i--; ) { + struct md_rdev *rdev; + sector_t first_bad; + int bad_sectors; + int is_bad = 0; + + dev = &sh->dev[i]; + + 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 + * + * 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++; + BUG_ON(s->compute > 2); + } + + 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++; + /* Prefer to use the replacement for reads, but only + * if it is recovered enough and has no bad blocks. + */ + rdev = rcu_dereference(conf->disks[i].replacement); + if (rdev && !test_bit(Faulty, &rdev->flags) && + rdev->recovery_offset >= sh->sector + STRIPE_SECTORS && + !is_badblock(rdev, sh->sector, STRIPE_SECTORS, + &first_bad, &bad_sectors)) + set_bit(R5_ReadRepl, &dev->flags); + else { + if (rdev && !test_bit(Faulty, &rdev->flags)) + set_bit(R5_NeedReplace, &dev->flags); + else + clear_bit(R5_NeedReplace, &dev->flags); + rdev = rcu_dereference(conf->disks[i].rdev); + clear_bit(R5_ReadRepl, &dev->flags); + } + if (rdev && test_bit(Faulty, &rdev->flags)) + rdev = NULL; + if (rdev) { + is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS, + &first_bad, &bad_sectors); + if (s->blocked_rdev == NULL + && (test_bit(Blocked, &rdev->flags) + || is_bad < 0)) { + if (is_bad < 0) + set_bit(BlockedBadBlocks, + &rdev->flags); + s->blocked_rdev = rdev; + atomic_inc(&rdev->nr_pending); + } + } + clear_bit(R5_Insync, &dev->flags); + if (!rdev) + /* Not in-sync */; + else if (is_bad) { + /* also not in-sync */ + if (!test_bit(WriteErrorSeen, &rdev->flags) && + test_bit(R5_UPTODATE, &dev->flags)) { + /* treat as in-sync, but with a read error + * which we can now try to correct + */ + set_bit(R5_Insync, &dev->flags); + set_bit(R5_ReadError, &dev->flags); + } + } else if (test_bit(In_sync, &rdev->flags)) + set_bit(R5_Insync, &dev->flags); + else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) + /* in sync if before recovery_offset */ + set_bit(R5_Insync, &dev->flags); + else if (test_bit(R5_UPTODATE, &dev->flags) && + test_bit(R5_Expanded, &dev->flags)) + /* If we've reshaped into here, we assume it is Insync. + * We will shortly update recovery_offset to make + * it official. + */ + set_bit(R5_Insync, &dev->flags); + + if (test_bit(R5_WriteError, &dev->flags)) { + /* This flag does not apply to '.replacement' + * only to .rdev, so make sure to check that*/ + struct md_rdev *rdev2 = rcu_dereference( + conf->disks[i].rdev); + if (rdev2 == rdev) + clear_bit(R5_Insync, &dev->flags); + if (rdev2 && !test_bit(Faulty, &rdev2->flags)) { + s->handle_bad_blocks = 1; + atomic_inc(&rdev2->nr_pending); + } else + clear_bit(R5_WriteError, &dev->flags); + } + if (test_bit(R5_MadeGood, &dev->flags)) { + /* This flag does not apply to '.replacement' + * only to .rdev, so make sure to check that*/ + struct md_rdev *rdev2 = rcu_dereference( + conf->disks[i].rdev); + if (rdev2 && !test_bit(Faulty, &rdev2->flags)) { + s->handle_bad_blocks = 1; + atomic_inc(&rdev2->nr_pending); + } else + clear_bit(R5_MadeGood, &dev->flags); + } + if (test_bit(R5_MadeGoodRepl, &dev->flags)) { + struct md_rdev *rdev2 = rcu_dereference( + conf->disks[i].replacement); + if (rdev2 && !test_bit(Faulty, &rdev2->flags)) { + s->handle_bad_blocks = 1; + atomic_inc(&rdev2->nr_pending); + } else + clear_bit(R5_MadeGoodRepl, &dev->flags); + } + if (!test_bit(R5_Insync, &dev->flags)) { + /* The ReadError flag will just be confusing now */ + clear_bit(R5_ReadError, &dev->flags); + clear_bit(R5_ReWrite, &dev->flags); + } + if (test_bit(R5_ReadError, &dev->flags)) + clear_bit(R5_Insync, &dev->flags); + if (!test_bit(R5_Insync, &dev->flags)) { + if (s->failed < 2) + s->failed_num[s->failed] = i; + s->failed++; + if (rdev && !test_bit(Faulty, &rdev->flags)) + do_recovery = 1; + else if (!rdev) { + rdev = rcu_dereference( + conf->disks[i].replacement); + if (rdev && !test_bit(Faulty, &rdev->flags)) + do_recovery = 1; + } + } + + if (test_bit(R5_InJournal, &dev->flags)) + s->injournal++; + if (test_bit(R5_InJournal, &dev->flags) && dev->written) + s->just_cached++; + } + if (test_bit(STRIPE_SYNCING, &sh->state)) { + /* If there is a failed device being replaced, + * we must be recovering. + * else if we are after recovery_cp, we must be syncing + * else if MD_RECOVERY_REQUESTED is set, we also are syncing. + * else we can only be replacing + * sync and recovery both need to read all devices, and so + * use the same flag. + */ + if (do_recovery || + sh->sector >= conf->mddev->recovery_cp || + test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery))) + s->syncing = 1; + else + s->replacing = 1; + } + rcu_read_unlock(); +} + +static int clear_batch_ready(struct stripe_head *sh) +{ + /* Return '1' if this is a member of batch, or + * '0' if it is a lone stripe or a head which can now be + * handled. + */ + struct stripe_head *tmp; + if (!test_and_clear_bit(STRIPE_BATCH_READY, &sh->state)) + return (sh->batch_head && sh->batch_head != sh); + spin_lock(&sh->stripe_lock); + if (!sh->batch_head) { + spin_unlock(&sh->stripe_lock); + return 0; + } + + /* + * this stripe could be added to a batch list before we check + * BATCH_READY, skips it + */ + if (sh->batch_head != sh) { + spin_unlock(&sh->stripe_lock); + return 1; + } + spin_lock(&sh->batch_lock); + list_for_each_entry(tmp, &sh->batch_list, batch_list) + clear_bit(STRIPE_BATCH_READY, &tmp->state); + spin_unlock(&sh->batch_lock); + spin_unlock(&sh->stripe_lock); + + /* + * BATCH_READY is cleared, no new stripes can be added. + * batch_list can be accessed without lock + */ + return 0; +} + +static void break_stripe_batch_list(struct stripe_head *head_sh, + unsigned long handle_flags) +{ + struct stripe_head *sh, *next; + int i; + int do_wakeup = 0; + + list_for_each_entry_safe(sh, next, &head_sh->batch_list, batch_list) { + + list_del_init(&sh->batch_list); + + WARN_ONCE(sh->state & ((1 << STRIPE_ACTIVE) | + (1 << STRIPE_SYNCING) | + (1 << STRIPE_REPLACED) | + (1 << STRIPE_DELAYED) | + (1 << STRIPE_BIT_DELAY) | + (1 << STRIPE_FULL_WRITE) | + (1 << STRIPE_BIOFILL_RUN) | + (1 << STRIPE_COMPUTE_RUN) | + (1 << STRIPE_OPS_REQ_PENDING) | + (1 << STRIPE_DISCARD) | + (1 << STRIPE_BATCH_READY) | + (1 << STRIPE_BATCH_ERR) | + (1 << STRIPE_BITMAP_PENDING)), + "stripe state: %lx\n", sh->state); + WARN_ONCE(head_sh->state & ((1 << STRIPE_DISCARD) | + (1 << STRIPE_REPLACED)), + "head stripe state: %lx\n", head_sh->state); + + set_mask_bits(&sh->state, ~(STRIPE_EXPAND_SYNC_FLAGS | + (1 << STRIPE_PREREAD_ACTIVE) | + (1 << STRIPE_DEGRADED) | + (1 << STRIPE_ON_UNPLUG_LIST)), + head_sh->state & (1 << STRIPE_INSYNC)); + + sh->check_state = head_sh->check_state; + sh->reconstruct_state = head_sh->reconstruct_state; + spin_lock_irq(&sh->stripe_lock); + sh->batch_head = NULL; + spin_unlock_irq(&sh->stripe_lock); + for (i = 0; i < sh->disks; i++) { + if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) + do_wakeup = 1; + sh->dev[i].flags = head_sh->dev[i].flags & + (~((1 << R5_WriteError) | (1 << R5_Overlap))); + } + if (handle_flags == 0 || + sh->state & handle_flags) + set_bit(STRIPE_HANDLE, &sh->state); + raid5_release_stripe(sh); + } + spin_lock_irq(&head_sh->stripe_lock); + head_sh->batch_head = NULL; + spin_unlock_irq(&head_sh->stripe_lock); + for (i = 0; i < head_sh->disks; i++) + if (test_and_clear_bit(R5_Overlap, &head_sh->dev[i].flags)) + do_wakeup = 1; + if (head_sh->state & handle_flags) + set_bit(STRIPE_HANDLE, &head_sh->state); + + if (do_wakeup) + wake_up(&head_sh->raid_conf->wait_for_overlap); +} + +static void handle_stripe(struct stripe_head *sh) +{ + struct stripe_head_state s; + struct r5conf *conf = sh->raid_conf; + int i; + int prexor; + int disks = sh->disks; + struct r5dev *pdev, *qdev; + + clear_bit(STRIPE_HANDLE, &sh->state); + if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) { + /* already being handled, ensure it gets handled + * again when current action finishes */ + set_bit(STRIPE_HANDLE, &sh->state); + return; + } + + if (clear_batch_ready(sh) ) { + clear_bit_unlock(STRIPE_ACTIVE, &sh->state); + return; + } + + if (test_and_clear_bit(STRIPE_BATCH_ERR, &sh->state)) + break_stripe_batch_list(sh, 0); + + if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) && !sh->batch_head) { + spin_lock(&sh->stripe_lock); + /* + * Cannot process 'sync' concurrently with 'discard'. + * Flush data in r5cache before 'sync'. + */ + if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) && + !test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state) && + !test_bit(STRIPE_DISCARD, &sh->state) && + test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { + set_bit(STRIPE_SYNCING, &sh->state); + clear_bit(STRIPE_INSYNC, &sh->state); + clear_bit(STRIPE_REPLACED, &sh->state); + } + spin_unlock(&sh->stripe_lock); + } + clear_bit(STRIPE_DELAYED, &sh->state); + + pr_debug("handling stripe %llu, state=%#lx cnt=%d, " + "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n", + (unsigned long long)sh->sector, sh->state, + atomic_read(&sh->count), sh->pd_idx, sh->qd_idx, + sh->check_state, sh->reconstruct_state); + + analyse_stripe(sh, &s); + + if (test_bit(STRIPE_LOG_TRAPPED, &sh->state)) + goto finish; + + if (s.handle_bad_blocks || + test_bit(MD_SB_CHANGE_PENDING, &conf->mddev->sb_flags)) { + set_bit(STRIPE_HANDLE, &sh->state); + goto finish; + } + + if (unlikely(s.blocked_rdev)) { + if (s.syncing || s.expanding || s.expanded || + s.replacing || s.to_write || s.written) { + set_bit(STRIPE_HANDLE, &sh->state); + goto finish; + } + /* There is nothing for the blocked_rdev to block */ + rdev_dec_pending(s.blocked_rdev, conf->mddev); + s.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,%d\n", + s.locked, s.uptodate, s.to_read, s.to_write, s.failed, + s.failed_num[0], s.failed_num[1]); + /* + * check if the array has lost more than max_degraded devices and, + * if so, some requests might need to be failed. + * + * When journal device failed (log_failed), we will only process + * the stripe if there is data need write to raid disks + */ + if (s.failed > conf->max_degraded || + (s.log_failed && s.injournal == 0)) { + sh->check_state = 0; + sh->reconstruct_state = 0; + break_stripe_batch_list(sh, 0); + if (s.to_read+s.to_write+s.written) + handle_failed_stripe(conf, sh, &s, disks); + if (s.syncing + s.replacing) + handle_failed_sync(conf, sh, &s); + } + + /* 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) && + !test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)); + BUG_ON(sh->qd_idx >= 0 && + !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags) && + !test_bit(R5_Discard, &sh->dev[sh->qd_idx].flags)); + for (i = disks; i--; ) { + struct r5dev *dev = &sh->dev[i]; + if (test_bit(R5_LOCKED, &dev->flags) && + (i == sh->pd_idx || i == sh->qd_idx || + dev->written || test_bit(R5_InJournal, + &dev->flags))) { + pr_debug("Writing block %d\n", i); + set_bit(R5_Wantwrite, &dev->flags); + if (prexor) + continue; + if (s.failed > 1) + continue; + if (!test_bit(R5_Insync, &dev->flags) || + ((i == sh->pd_idx || i == sh->qd_idx) && + s.failed == 0)) + set_bit(STRIPE_INSYNC, &sh->state); + } + } + if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + s.dec_preread_active = 1; + } + + /* + * might be able to return some write requests if the parity blocks + * are safe, or on a failed drive + */ + pdev = &sh->dev[sh->pd_idx]; + s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx) + || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx); + qdev = &sh->dev[sh->qd_idx]; + s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx) + || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx) + || conf->level < 6; + + if (s.written && + (s.p_failed || ((test_bit(R5_Insync, &pdev->flags) + && !test_bit(R5_LOCKED, &pdev->flags) + && (test_bit(R5_UPTODATE, &pdev->flags) || + test_bit(R5_Discard, &pdev->flags))))) && + (s.q_failed || ((test_bit(R5_Insync, &qdev->flags) + && !test_bit(R5_LOCKED, &qdev->flags) + && (test_bit(R5_UPTODATE, &qdev->flags) || + test_bit(R5_Discard, &qdev->flags)))))) + handle_stripe_clean_event(conf, sh, disks); + + if (s.just_cached) + r5c_handle_cached_data_endio(conf, sh, disks); + log_stripe_write_finished(sh); + + /* 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 + s.compute < disks)) + || s.replacing + || s.expanding) + handle_stripe_fill(sh, &s, disks); + + /* + * When the stripe finishes full journal write cycle (write to journal + * and raid disk), this is the clean up procedure so it is ready for + * next operation. + */ + r5c_finish_stripe_write_out(conf, sh, &s); + + /* + * Now to consider new write requests, cache write back 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. + * 3/ A r5c cache log write is in flight. + */ + + if (!sh->reconstruct_state && !sh->check_state && !sh->log_io) { + if (!r5c_is_writeback(conf->log)) { + if (s.to_write) + handle_stripe_dirtying(conf, sh, &s, disks); + } else { /* write back cache */ + int ret = 0; + + /* First, try handle writes in caching phase */ + if (s.to_write) + ret = r5c_try_caching_write(conf, sh, &s, + disks); + /* + * If caching phase failed: ret == -EAGAIN + * OR + * stripe under reclaim: !caching && injournal + * + * fall back to handle_stripe_dirtying() + */ + if (ret == -EAGAIN || + /* stripe under reclaim: !caching && injournal */ + (!test_bit(STRIPE_R5C_CACHING, &sh->state) && + s.injournal > 0)) { + ret = handle_stripe_dirtying(conf, sh, &s, + disks); + if (ret == -EAGAIN) + goto finish; + } + } + } + + /* 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))) { + if (conf->level == 6) + handle_parity_checks6(conf, sh, &s, disks); + else + handle_parity_checks5(conf, sh, &s, disks); + } + + if ((s.replacing || s.syncing) && s.locked == 0 + && !test_bit(STRIPE_COMPUTE_RUN, &sh->state) + && !test_bit(STRIPE_REPLACED, &sh->state)) { + /* Write out to replacement devices where possible */ + for (i = 0; i < conf->raid_disks; i++) + if (test_bit(R5_NeedReplace, &sh->dev[i].flags)) { + WARN_ON(!test_bit(R5_UPTODATE, &sh->dev[i].flags)); + set_bit(R5_WantReplace, &sh->dev[i].flags); + set_bit(R5_LOCKED, &sh->dev[i].flags); + s.locked++; + } + if (s.replacing) + set_bit(STRIPE_INSYNC, &sh->state); + set_bit(STRIPE_REPLACED, &sh->state); + } + if ((s.syncing || s.replacing) && s.locked == 0 && + !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && + test_bit(STRIPE_INSYNC, &sh->state)) { + md_done_sync(conf->mddev, STRIPE_SECTORS, 1); + clear_bit(STRIPE_SYNCING, &sh->state); + if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags)) + wake_up(&conf->wait_for_overlap); + } + + /* If the failed drives are just a ReadError, then we might need + * to progress the repair/check process + */ + if (s.failed <= conf->max_degraded && !conf->mddev->ro) + for (i = 0; i < s.failed; i++) { + struct r5dev *dev = &sh->dev[s.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); + 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) { + struct stripe_head *sh_src + = raid5_get_active_stripe(conf, sh->sector, 1, 1, 1); + if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) { + /* sh cannot be written until sh_src has been read. + * so arrange for sh to be delayed a little + */ + set_bit(STRIPE_DELAYED, &sh->state); + set_bit(STRIPE_HANDLE, &sh->state); + if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, + &sh_src->state)) + atomic_inc(&conf->preread_active_stripes); + raid5_release_stripe(sh_src); + goto finish; + } + if (sh_src) + raid5_release_stripe(sh_src); + + 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; + stripe_set_idx(sh->sector, conf, 0, sh); + schedule_reconstruction(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); + +finish: + /* wait for this device to become unblocked */ + if (unlikely(s.blocked_rdev)) { + if (conf->mddev->external) + md_wait_for_blocked_rdev(s.blocked_rdev, + conf->mddev); + else + /* Internal metadata will immediately + * be written by raid5d, so we don't + * need to wait here. + */ + rdev_dec_pending(s.blocked_rdev, + conf->mddev); + } + + if (s.handle_bad_blocks) + for (i = disks; i--; ) { + struct md_rdev *rdev; + struct r5dev *dev = &sh->dev[i]; + if (test_and_clear_bit(R5_WriteError, &dev->flags)) { + /* We own a safe reference to the rdev */ + rdev = conf->disks[i].rdev; + if (!rdev_set_badblocks(rdev, sh->sector, + STRIPE_SECTORS, 0)) + md_error(conf->mddev, rdev); + rdev_dec_pending(rdev, conf->mddev); + } + if (test_and_clear_bit(R5_MadeGood, &dev->flags)) { + rdev = conf->disks[i].rdev; + rdev_clear_badblocks(rdev, sh->sector, + STRIPE_SECTORS, 0); + rdev_dec_pending(rdev, conf->mddev); + } + if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) { + rdev = conf->disks[i].replacement; + if (!rdev) + /* rdev have been moved down */ + rdev = conf->disks[i].rdev; + rdev_clear_badblocks(rdev, sh->sector, + STRIPE_SECTORS, 0); + rdev_dec_pending(rdev, conf->mddev); + } + } + + if (s.ops_request) + raid_run_ops(sh, s.ops_request); + + ops_run_io(sh, &s); + + if (s.dec_preread_active) { + /* We delay this until after ops_run_io so that if make_request + * is waiting on a flush, it won't continue until the writes + * have actually been submitted. + */ + atomic_dec(&conf->preread_active_stripes); + if (atomic_read(&conf->preread_active_stripes) < + IO_THRESHOLD) + md_wakeup_thread(conf->mddev->thread); + } + + clear_bit_unlock(STRIPE_ACTIVE, &sh->state); +} + +static void raid5_activate_delayed(struct r5conf *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); + raid5_wakeup_stripe_thread(sh); + } + } +} + +static void activate_bit_delay(struct r5conf *conf, + struct list_head *temp_inactive_list) +{ + /* 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); + int hash; + list_del_init(&sh->lru); + atomic_inc(&sh->count); + hash = sh->hash_lock_index; + __release_stripe(conf, sh, &temp_inactive_list[hash]); + } +} + +static int raid5_congested(struct mddev *mddev, int bits) +{ + struct r5conf *conf = mddev->private; + + /* No difference between reads and writes. Just check + * how busy the stripe_cache is + */ + + if (test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) + return 1; + + /* Also checks whether there is pressure on r5cache log space */ + if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) + return 1; + if (conf->quiesce) + return 1; + if (atomic_read(&conf->empty_inactive_list_nr)) + return 1; + + return 0; +} + +static int in_chunk_boundary(struct mddev *mddev, struct bio *bio) +{ + struct r5conf *conf = mddev->private; + sector_t sector = bio->bi_iter.bi_sector; + unsigned int chunk_sectors; + unsigned int bio_sectors = bio_sectors(bio); + + WARN_ON_ONCE(bio->bi_partno); + + chunk_sectors = min(conf->chunk_sectors, conf->prev_chunk_sectors); + 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,struct r5conf *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(struct r5conf *conf, + unsigned int *offset) +{ + struct bio *bi; + + bi = conf->retry_read_aligned; + if (bi) { + *offset = conf->retry_read_offset; + 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; + *offset = 0; + } + + 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) +{ + struct bio* raid_bi = bi->bi_private; + struct mddev *mddev; + struct r5conf *conf; + struct md_rdev *rdev; + blk_status_t error = bi->bi_status; + + bio_put(bi); + + rdev = (void*)raid_bi->bi_next; + raid_bi->bi_next = NULL; + mddev = rdev->mddev; + conf = mddev->private; + + rdev_dec_pending(rdev, conf->mddev); + + if (!error) { + bio_endio(raid_bi); + if (atomic_dec_and_test(&conf->active_aligned_reads)) + wake_up(&conf->wait_for_quiescent); + return; + } + + pr_debug("raid5_align_endio : io error...handing IO for a retry\n"); + + add_bio_to_retry(raid_bi, conf); +} + +static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio) +{ + struct r5conf *conf = mddev->private; + int dd_idx; + struct bio* align_bi; + struct md_rdev *rdev; + sector_t end_sector; + + if (!in_chunk_boundary(mddev, raid_bio)) { + pr_debug("%s: non aligned\n", __func__); + return 0; + } + /* + * use bio_clone_fast to make a copy of the bio + */ + align_bi = bio_clone_fast(raid_bio, GFP_NOIO, &mddev->bio_set); + 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_iter.bi_sector = + raid5_compute_sector(conf, raid_bio->bi_iter.bi_sector, + 0, &dd_idx, NULL); + + end_sector = bio_end_sector(align_bi); + rcu_read_lock(); + rdev = rcu_dereference(conf->disks[dd_idx].replacement); + if (!rdev || test_bit(Faulty, &rdev->flags) || + rdev->recovery_offset < end_sector) { + rdev = rcu_dereference(conf->disks[dd_idx].rdev); + if (rdev && + (test_bit(Faulty, &rdev->flags) || + !(test_bit(In_sync, &rdev->flags) || + rdev->recovery_offset >= end_sector))) + rdev = NULL; + } + + if (r5c_big_stripe_cached(conf, align_bi->bi_iter.bi_sector)) { + rcu_read_unlock(); + bio_put(align_bi); + return 0; + } + + if (rdev) { + sector_t first_bad; + int bad_sectors; + + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + raid_bio->bi_next = (void*)rdev; + bio_set_dev(align_bi, rdev->bdev); + bio_clear_flag(align_bi, BIO_SEG_VALID); + + if (is_badblock(rdev, align_bi->bi_iter.bi_sector, + bio_sectors(align_bi), + &first_bad, &bad_sectors)) { + bio_put(align_bi); + rdev_dec_pending(rdev, mddev); + return 0; + } + + /* No reshape active, so we can trust rdev->data_offset */ + align_bi->bi_iter.bi_sector += rdev->data_offset; + + spin_lock_irq(&conf->device_lock); + wait_event_lock_irq(conf->wait_for_quiescent, + conf->quiesce == 0, + conf->device_lock); + atomic_inc(&conf->active_aligned_reads); + spin_unlock_irq(&conf->device_lock); + + if (mddev->gendisk) + trace_block_bio_remap(align_bi->bi_disk->queue, + align_bi, disk_devt(mddev->gendisk), + raid_bio->bi_iter.bi_sector); + generic_make_request(align_bi); + return 1; + } else { + rcu_read_unlock(); + bio_put(align_bi); + return 0; + } +} + +static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio) +{ + struct bio *split; + sector_t sector = raid_bio->bi_iter.bi_sector; + unsigned chunk_sects = mddev->chunk_sectors; + unsigned sectors = chunk_sects - (sector & (chunk_sects-1)); + + if (sectors < bio_sectors(raid_bio)) { + struct r5conf *conf = mddev->private; + split = bio_split(raid_bio, sectors, GFP_NOIO, &conf->bio_split); + bio_chain(split, raid_bio); + generic_make_request(raid_bio); + raid_bio = split; + } + + if (!raid5_read_one_chunk(mddev, raid_bio)) + return raid_bio; + + return NULL; +} + +/* __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(struct r5conf *conf, int group) +{ + struct stripe_head *sh, *tmp; + struct list_head *handle_list = NULL; + struct r5worker_group *wg; + bool second_try = !r5c_is_writeback(conf->log) && + !r5l_log_disk_error(conf); + bool try_loprio = test_bit(R5C_LOG_TIGHT, &conf->cache_state) || + r5l_log_disk_error(conf); + +again: + wg = NULL; + sh = NULL; + if (conf->worker_cnt_per_group == 0) { + handle_list = try_loprio ? &conf->loprio_list : + &conf->handle_list; + } else if (group != ANY_GROUP) { + handle_list = try_loprio ? &conf->worker_groups[group].loprio_list : + &conf->worker_groups[group].handle_list; + wg = &conf->worker_groups[group]; + } else { + int i; + for (i = 0; i < conf->group_cnt; i++) { + handle_list = try_loprio ? &conf->worker_groups[i].loprio_list : + &conf->worker_groups[i].handle_list; + wg = &conf->worker_groups[i]; + if (!list_empty(handle_list)) + break; + } + } + + pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n", + __func__, + list_empty(handle_list) ? "empty" : "busy", + list_empty(&conf->hold_list) ? "empty" : "busy", + atomic_read(&conf->pending_full_writes), conf->bypass_count); + + if (!list_empty(handle_list)) { + sh = list_entry(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)) { + + list_for_each_entry(tmp, &conf->hold_list, lru) { + if (conf->worker_cnt_per_group == 0 || + group == ANY_GROUP || + !cpu_online(tmp->cpu) || + cpu_to_group(tmp->cpu) == group) { + sh = tmp; + break; + } + } + + if (sh) { + conf->bypass_count -= conf->bypass_threshold; + if (conf->bypass_count < 0) + conf->bypass_count = 0; + } + wg = NULL; + } + + if (!sh) { + if (second_try) + return NULL; + second_try = true; + try_loprio = !try_loprio; + goto again; + } + + if (wg) { + wg->stripes_cnt--; + sh->group = NULL; + } + list_del_init(&sh->lru); + BUG_ON(atomic_inc_return(&sh->count) != 1); + return sh; +} + +struct raid5_plug_cb { + struct blk_plug_cb cb; + struct list_head list; + struct list_head temp_inactive_list[NR_STRIPE_HASH_LOCKS]; +}; + +static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule) +{ + struct raid5_plug_cb *cb = container_of( + blk_cb, struct raid5_plug_cb, cb); + struct stripe_head *sh; + struct mddev *mddev = cb->cb.data; + struct r5conf *conf = mddev->private; + int cnt = 0; + int hash; + + if (cb->list.next && !list_empty(&cb->list)) { + spin_lock_irq(&conf->device_lock); + while (!list_empty(&cb->list)) { + sh = list_first_entry(&cb->list, struct stripe_head, lru); + list_del_init(&sh->lru); + /* + * avoid race release_stripe_plug() sees + * STRIPE_ON_UNPLUG_LIST clear but the stripe + * is still in our list + */ + smp_mb__before_atomic(); + clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state); + /* + * STRIPE_ON_RELEASE_LIST could be set here. In that + * case, the count is always > 1 here + */ + hash = sh->hash_lock_index; + __release_stripe(conf, sh, &cb->temp_inactive_list[hash]); + cnt++; + } + spin_unlock_irq(&conf->device_lock); + } + release_inactive_stripe_list(conf, cb->temp_inactive_list, + NR_STRIPE_HASH_LOCKS); + if (mddev->queue) + trace_block_unplug(mddev->queue, cnt, !from_schedule); + kfree(cb); +} + +static void release_stripe_plug(struct mddev *mddev, + struct stripe_head *sh) +{ + struct blk_plug_cb *blk_cb = blk_check_plugged( + raid5_unplug, mddev, + sizeof(struct raid5_plug_cb)); + struct raid5_plug_cb *cb; + + if (!blk_cb) { + raid5_release_stripe(sh); + return; + } + + cb = container_of(blk_cb, struct raid5_plug_cb, cb); + + if (cb->list.next == NULL) { + int i; + INIT_LIST_HEAD(&cb->list); + for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) + INIT_LIST_HEAD(cb->temp_inactive_list + i); + } + + if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST, &sh->state)) + list_add_tail(&sh->lru, &cb->list); + else + raid5_release_stripe(sh); +} + +static void make_discard_request(struct mddev *mddev, struct bio *bi) +{ + struct r5conf *conf = mddev->private; + sector_t logical_sector, last_sector; + struct stripe_head *sh; + int stripe_sectors; + + if (mddev->reshape_position != MaxSector) + /* Skip discard while reshape is happening */ + return; + + logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1); + last_sector = bi->bi_iter.bi_sector + (bi->bi_iter.bi_size>>9); + + bi->bi_next = NULL; + + stripe_sectors = conf->chunk_sectors * + (conf->raid_disks - conf->max_degraded); + logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector, + stripe_sectors); + sector_div(last_sector, stripe_sectors); + + logical_sector *= conf->chunk_sectors; + last_sector *= conf->chunk_sectors; + + for (; logical_sector < last_sector; + logical_sector += STRIPE_SECTORS) { + DEFINE_WAIT(w); + int d; + again: + sh = raid5_get_active_stripe(conf, logical_sector, 0, 0, 0); + prepare_to_wait(&conf->wait_for_overlap, &w, + TASK_UNINTERRUPTIBLE); + set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags); + if (test_bit(STRIPE_SYNCING, &sh->state)) { + raid5_release_stripe(sh); + schedule(); + goto again; + } + clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags); + spin_lock_irq(&sh->stripe_lock); + for (d = 0; d < conf->raid_disks; d++) { + if (d == sh->pd_idx || d == sh->qd_idx) + continue; + if (sh->dev[d].towrite || sh->dev[d].toread) { + set_bit(R5_Overlap, &sh->dev[d].flags); + spin_unlock_irq(&sh->stripe_lock); + raid5_release_stripe(sh); + schedule(); + goto again; + } + } + set_bit(STRIPE_DISCARD, &sh->state); + finish_wait(&conf->wait_for_overlap, &w); + sh->overwrite_disks = 0; + for (d = 0; d < conf->raid_disks; d++) { + if (d == sh->pd_idx || d == sh->qd_idx) + continue; + sh->dev[d].towrite = bi; + set_bit(R5_OVERWRITE, &sh->dev[d].flags); + bio_inc_remaining(bi); + md_write_inc(mddev, bi); + sh->overwrite_disks++; + } + spin_unlock_irq(&sh->stripe_lock); + if (conf->mddev->bitmap) { + for (d = 0; + d < conf->raid_disks - conf->max_degraded; + d++) + md_bitmap_startwrite(mddev->bitmap, + sh->sector, + STRIPE_SECTORS, + 0); + sh->bm_seq = conf->seq_flush + 1; + set_bit(STRIPE_BIT_DELAY, &sh->state); + } + + set_bit(STRIPE_HANDLE, &sh->state); + clear_bit(STRIPE_DELAYED, &sh->state); + if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + atomic_inc(&conf->preread_active_stripes); + release_stripe_plug(mddev, sh); + } + + bio_endio(bi); +} + +static bool raid5_make_request(struct mddev *mddev, struct bio * bi) +{ + struct r5conf *conf = mddev->private; + int dd_idx; + sector_t new_sector; + sector_t logical_sector, last_sector; + struct stripe_head *sh; + const int rw = bio_data_dir(bi); + DEFINE_WAIT(w); + bool do_prepare; + bool do_flush = false; + + if (unlikely(bi->bi_opf & REQ_PREFLUSH)) { + int ret = log_handle_flush_request(conf, bi); + + if (ret == 0) + return true; + if (ret == -ENODEV) { + if (md_flush_request(mddev, bi)) + return true; + } + /* ret == -EAGAIN, fallback */ + /* + * if r5l_handle_flush_request() didn't clear REQ_PREFLUSH, + * we need to flush journal device + */ + do_flush = bi->bi_opf & REQ_PREFLUSH; + } + + if (!md_write_start(mddev, bi)) + return false; + /* + * If array is degraded, better not do chunk aligned read because + * later we might have to read it again in order to reconstruct + * data on failed drives. + */ + if (rw == READ && mddev->degraded == 0 && + mddev->reshape_position == MaxSector) { + bi = chunk_aligned_read(mddev, bi); + if (!bi) + return true; + } + + if (unlikely(bio_op(bi) == REQ_OP_DISCARD)) { + make_discard_request(mddev, bi); + md_write_end(mddev); + return true; + } + + logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1); + last_sector = bio_end_sector(bi); + bi->bi_next = NULL; + + prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); + for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { + int previous; + int seq; + + do_prepare = false; + retry: + seq = read_seqcount_begin(&conf->gen_lock); + previous = 0; + if (do_prepare) + prepare_to_wait(&conf->wait_for_overlap, &w, + TASK_UNINTERRUPTIBLE); + if (unlikely(conf->reshape_progress != MaxSector)) { + /* spinlock is needed as reshape_progress may be + * 64bit on a 32bit platform, and so it might be + * possible to see a half-updated value + * Of course reshape_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); + if (mddev->reshape_backwards + ? logical_sector < conf->reshape_progress + : logical_sector >= conf->reshape_progress) { + previous = 1; + } else { + if (mddev->reshape_backwards + ? logical_sector < conf->reshape_safe + : logical_sector >= conf->reshape_safe) { + spin_unlock_irq(&conf->device_lock); + schedule(); + do_prepare = true; + goto retry; + } + } + spin_unlock_irq(&conf->device_lock); + } + + new_sector = raid5_compute_sector(conf, logical_sector, + previous, + &dd_idx, NULL); + pr_debug("raid456: raid5_make_request, sector %llu logical %llu\n", + (unsigned long long)new_sector, + (unsigned long long)logical_sector); + + sh = raid5_get_active_stripe(conf, new_sector, previous, + (bi->bi_opf & REQ_RAHEAD), 0); + if (sh) { + if (unlikely(previous)) { + /* 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 (mddev->reshape_backwards + ? logical_sector >= conf->reshape_progress + : logical_sector < conf->reshape_progress) + /* mismatch, need to try again */ + must_retry = 1; + spin_unlock_irq(&conf->device_lock); + if (must_retry) { + raid5_release_stripe(sh); + schedule(); + do_prepare = true; + goto retry; + } + } + if (read_seqcount_retry(&conf->gen_lock, seq)) { + /* Might have got the wrong stripe_head + * by accident + */ + raid5_release_stripe(sh); + goto retry; + } + + if (test_bit(STRIPE_EXPANDING, &sh->state) || + !add_stripe_bio(sh, bi, dd_idx, rw, previous)) { + /* Stripe is busy expanding or + * add failed due to overlap. Flush everything + * and wait a while + */ + md_wakeup_thread(mddev->thread); + raid5_release_stripe(sh); + schedule(); + do_prepare = true; + goto retry; + } + if (do_flush) { + set_bit(STRIPE_R5C_PREFLUSH, &sh->state); + /* we only need flush for one stripe */ + do_flush = false; + } + + if (!sh->batch_head || sh == sh->batch_head) + set_bit(STRIPE_HANDLE, &sh->state); + clear_bit(STRIPE_DELAYED, &sh->state); + if ((!sh->batch_head || sh == sh->batch_head) && + (bi->bi_opf & REQ_SYNC) && + !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + atomic_inc(&conf->preread_active_stripes); + release_stripe_plug(mddev, sh); + } else { + /* cannot get stripe for read-ahead, just give-up */ + bi->bi_status = BLK_STS_IOERR; + break; + } + } + finish_wait(&conf->wait_for_overlap, &w); + + if (rw == WRITE) + md_write_end(mddev); + bio_endio(bi); + return true; +} + +static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks); + +static sector_t reshape_request(struct mddev *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. + */ + struct r5conf *conf = mddev->private; + struct stripe_head *sh; + struct md_rdev *rdev; + 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, readpos, safepos; + sector_t stripe_addr; + int reshape_sectors; + struct list_head stripes; + sector_t retn; + + if (sector_nr == 0) { + /* If restarting in the middle, skip the initial sectors */ + if (mddev->reshape_backwards && + conf->reshape_progress < raid5_size(mddev, 0, 0)) { + sector_nr = raid5_size(mddev, 0, 0) + - conf->reshape_progress; + } else if (mddev->reshape_backwards && + conf->reshape_progress == MaxSector) { + /* shouldn't happen, but just in case, finish up.*/ + sector_nr = MaxSector; + } else if (!mddev->reshape_backwards && + conf->reshape_progress > 0) + sector_nr = conf->reshape_progress; + sector_div(sector_nr, new_data_disks); + if (sector_nr) { + mddev->curr_resync_completed = sector_nr; + sysfs_notify(&mddev->kobj, NULL, "sync_completed"); + *skipped = 1; + retn = sector_nr; + goto finish; + } + } + + /* We need to process a full chunk at a time. + * If old and new chunk sizes differ, we need to process the + * largest of these + */ + + reshape_sectors = max(conf->chunk_sectors, conf->prev_chunk_sectors); + + /* We update the metadata at least every 10 seconds, 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 + * along from reshape_progress new_maps to after where + * reshape_safe old_maps to + */ + writepos = conf->reshape_progress; + sector_div(writepos, new_data_disks); + readpos = conf->reshape_progress; + sector_div(readpos, data_disks); + safepos = conf->reshape_safe; + sector_div(safepos, data_disks); + if (mddev->reshape_backwards) { + BUG_ON(writepos < reshape_sectors); + writepos -= reshape_sectors; + readpos += reshape_sectors; + safepos += reshape_sectors; + } else { + writepos += reshape_sectors; + /* readpos and safepos are worst-case calculations. + * A negative number is overly pessimistic, and causes + * obvious problems for unsigned storage. So clip to 0. + */ + readpos -= min_t(sector_t, reshape_sectors, readpos); + safepos -= min_t(sector_t, reshape_sectors, safepos); + } + + /* Having calculated the 'writepos' possibly use it + * to set 'stripe_addr' which is where we will write to. + */ + if (mddev->reshape_backwards) { + BUG_ON(conf->reshape_progress == 0); + stripe_addr = writepos; + BUG_ON((mddev->dev_sectors & + ~((sector_t)reshape_sectors - 1)) + - reshape_sectors - stripe_addr + != sector_nr); + } else { + BUG_ON(writepos != sector_nr + reshape_sectors); + stripe_addr = sector_nr; + } + + /* 'writepos' is the most advanced device address we might write. + * 'readpos' is the least advanced device address we might read. + * 'safepos' is the least address recorded in the metadata as having + * been reshaped. + * If there is a min_offset_diff, these are adjusted either by + * increasing the safepos/readpos if diff is negative, or + * increasing writepos if diff is positive. + * If 'readpos' is then behind 'writepos', there is no way that we can + * ensure safety in the face of a crash - that must be done by userspace + * making a backup of the data. So in that case there is no particular + * rush to update metadata. + * Otherwise if 'safepos' is behind 'writepos', then we really need to + * update the metadata to advance 'safepos' to match 'readpos' so that + * we can be safe in the event of a crash. + * So we insist on updating metadata if safepos is behind writepos and + * readpos is beyond writepos. + * In any case, update the metadata every 10 seconds. + * Maybe that number should be configurable, but I'm not sure it is + * worth it.... maybe it could be a multiple of safemode_delay??? + */ + if (conf->min_offset_diff < 0) { + safepos += -conf->min_offset_diff; + readpos += -conf->min_offset_diff; + } else + writepos += conf->min_offset_diff; + + if ((mddev->reshape_backwards + ? (safepos > writepos && readpos < writepos) + : (safepos < writepos && readpos > writepos)) || + time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) { + /* Cannot proceed until we've updated the superblock... */ + wait_event(conf->wait_for_overlap, + atomic_read(&conf->reshape_stripes)==0 + || test_bit(MD_RECOVERY_INTR, &mddev->recovery)); + if (atomic_read(&conf->reshape_stripes) != 0) + return 0; + mddev->reshape_position = conf->reshape_progress; + mddev->curr_resync_completed = sector_nr; + if (!mddev->reshape_backwards) + /* Can update recovery_offset */ + rdev_for_each(rdev, mddev) + if (rdev->raid_disk >= 0 && + !test_bit(Journal, &rdev->flags) && + !test_bit(In_sync, &rdev->flags) && + rdev->recovery_offset < sector_nr) + rdev->recovery_offset = sector_nr; + + conf->reshape_checkpoint = jiffies; + set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); + md_wakeup_thread(mddev->thread); + wait_event(mddev->sb_wait, mddev->sb_flags == 0 || + test_bit(MD_RECOVERY_INTR, &mddev->recovery)); + if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) + return 0; + spin_lock_irq(&conf->device_lock); + conf->reshape_safe = mddev->reshape_position; + spin_unlock_irq(&conf->device_lock); + wake_up(&conf->wait_for_overlap); + sysfs_notify(&mddev->kobj, NULL, "sync_completed"); + } + + INIT_LIST_HEAD(&stripes); + for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) { + int j; + int skipped_disk = 0; + sh = raid5_get_active_stripe(conf, stripe_addr+i, 0, 0, 1); + 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 == sh->qd_idx) + continue; + s = raid5_compute_blocknr(sh, j, 0); + if (s < raid5_size(mddev, 0, 0)) { + skipped_disk = 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_disk) { + set_bit(STRIPE_EXPAND_READY, &sh->state); + set_bit(STRIPE_HANDLE, &sh->state); + } + list_add(&sh->lru, &stripes); + } + spin_lock_irq(&conf->device_lock); + if (mddev->reshape_backwards) + conf->reshape_progress -= reshape_sectors * new_data_disks; + else + conf->reshape_progress += reshape_sectors * 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(conf, stripe_addr*(new_data_disks), + 1, &dd_idx, NULL); + last_sector = + raid5_compute_sector(conf, ((stripe_addr+reshape_sectors) + * new_data_disks - 1), + 1, &dd_idx, NULL); + if (last_sector >= mddev->dev_sectors) + last_sector = mddev->dev_sectors - 1; + while (first_sector <= last_sector) { + sh = raid5_get_active_stripe(conf, first_sector, 1, 0, 1); + set_bit(STRIPE_EXPAND_SOURCE, &sh->state); + set_bit(STRIPE_HANDLE, &sh->state); + raid5_release_stripe(sh); + first_sector += STRIPE_SECTORS; + } + /* Now that the sources are clearly marked, we can release + * the destination stripes + */ + while (!list_empty(&stripes)) { + sh = list_entry(stripes.next, struct stripe_head, lru); + list_del_init(&sh->lru); + raid5_release_stripe(sh); + } + /* If this takes us to the resync_max point where we have to pause, + * then we need to write out the superblock. + */ + sector_nr += reshape_sectors; + retn = reshape_sectors; +finish: + if (mddev->curr_resync_completed > mddev->resync_max || + (sector_nr - mddev->curr_resync_completed) * 2 + >= mddev->resync_max - mddev->curr_resync_completed) { + /* Cannot proceed until we've updated the superblock... */ + wait_event(conf->wait_for_overlap, + atomic_read(&conf->reshape_stripes) == 0 + || test_bit(MD_RECOVERY_INTR, &mddev->recovery)); + if (atomic_read(&conf->reshape_stripes) != 0) + goto ret; + mddev->reshape_position = conf->reshape_progress; + mddev->curr_resync_completed = sector_nr; + if (!mddev->reshape_backwards) + /* Can update recovery_offset */ + rdev_for_each(rdev, mddev) + if (rdev->raid_disk >= 0 && + !test_bit(Journal, &rdev->flags) && + !test_bit(In_sync, &rdev->flags) && + rdev->recovery_offset < sector_nr) + rdev->recovery_offset = sector_nr; + conf->reshape_checkpoint = jiffies; + set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); + md_wakeup_thread(mddev->thread); + wait_event(mddev->sb_wait, + !test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags) + || test_bit(MD_RECOVERY_INTR, &mddev->recovery)); + if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) + goto ret; + spin_lock_irq(&conf->device_lock); + conf->reshape_safe = mddev->reshape_position; + spin_unlock_irq(&conf->device_lock); + wake_up(&conf->wait_for_overlap); + sysfs_notify(&mddev->kobj, NULL, "sync_completed"); + } +ret: + return retn; +} + +static inline sector_t raid5_sync_request(struct mddev *mddev, sector_t sector_nr, + int *skipped) +{ + struct r5conf *conf = mddev->private; + struct stripe_head *sh; + sector_t max_sector = mddev->dev_sectors; + sector_t sync_blocks; + int still_degraded = 0; + int i; + + if (sector_nr >= max_sector) { + /* just being told to finish up .. nothing much to do */ + + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { + end_reshape(conf); + return 0; + } + + if (mddev->curr_resync < max_sector) /* aborted */ + md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync, + &sync_blocks, 1); + else /* completed sync */ + conf->fullsync = 0; + md_bitmap_close_sync(mddev->bitmap); + + return 0; + } + + /* Allow raid5_quiesce to complete */ + wait_event(conf->wait_for_overlap, conf->quiesce != 2); + + 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->dev_sectors - sector_nr; + *skipped = 1; + return rv; + } + if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && + !conf->fullsync && + !md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && + 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 */ + } + + md_bitmap_cond_end_sync(mddev->bitmap, sector_nr, false); + + sh = raid5_get_active_stripe(conf, sector_nr, 0, 1, 0); + if (sh == NULL) { + sh = raid5_get_active_stripe(conf, sector_nr, 0, 0, 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 + * Note in case of > 1 drive failures it's possible we're rebuilding + * one drive while leaving another faulty drive in array. + */ + rcu_read_lock(); + for (i = 0; i < conf->raid_disks; i++) { + struct md_rdev *rdev = READ_ONCE(conf->disks[i].rdev); + + if (rdev == NULL || test_bit(Faulty, &rdev->flags)) + still_degraded = 1; + } + rcu_read_unlock(); + + md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); + + set_bit(STRIPE_SYNC_REQUESTED, &sh->state); + set_bit(STRIPE_HANDLE, &sh->state); + + raid5_release_stripe(sh); + + return STRIPE_SECTORS; +} + +static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio, + unsigned int offset) +{ + /* 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; + sector_t sector, logical_sector, last_sector; + int scnt = 0; + int handled = 0; + + logical_sector = raid_bio->bi_iter.bi_sector & + ~((sector_t)STRIPE_SECTORS-1); + sector = raid5_compute_sector(conf, logical_sector, + 0, &dd_idx, NULL); + last_sector = bio_end_sector(raid_bio); + + for (; logical_sector < last_sector; + logical_sector += STRIPE_SECTORS, + sector += STRIPE_SECTORS, + scnt++) { + + if (scnt < offset) + /* already done this stripe */ + continue; + + sh = raid5_get_active_stripe(conf, sector, 0, 1, 1); + + if (!sh) { + /* failed to get a stripe - must wait */ + conf->retry_read_aligned = raid_bio; + conf->retry_read_offset = scnt; + return handled; + } + + if (!add_stripe_bio(sh, raid_bio, dd_idx, 0, 0)) { + raid5_release_stripe(sh); + conf->retry_read_aligned = raid_bio; + conf->retry_read_offset = scnt; + return handled; + } + + set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags); + handle_stripe(sh); + raid5_release_stripe(sh); + handled++; + } + + bio_endio(raid_bio); + + if (atomic_dec_and_test(&conf->active_aligned_reads)) + wake_up(&conf->wait_for_quiescent); + return handled; +} + +static int handle_active_stripes(struct r5conf *conf, int group, + struct r5worker *worker, + struct list_head *temp_inactive_list) +{ + struct stripe_head *batch[MAX_STRIPE_BATCH], *sh; + int i, batch_size = 0, hash; + bool release_inactive = false; + + while (batch_size < MAX_STRIPE_BATCH && + (sh = __get_priority_stripe(conf, group)) != NULL) + batch[batch_size++] = sh; + + if (batch_size == 0) { + for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) + if (!list_empty(temp_inactive_list + i)) + break; + if (i == NR_STRIPE_HASH_LOCKS) { + spin_unlock_irq(&conf->device_lock); + log_flush_stripe_to_raid(conf); + spin_lock_irq(&conf->device_lock); + return batch_size; + } + release_inactive = true; + } + spin_unlock_irq(&conf->device_lock); + + release_inactive_stripe_list(conf, temp_inactive_list, + NR_STRIPE_HASH_LOCKS); + + r5l_flush_stripe_to_raid(conf->log); + if (release_inactive) { + spin_lock_irq(&conf->device_lock); + return 0; + } + + for (i = 0; i < batch_size; i++) + handle_stripe(batch[i]); + log_write_stripe_run(conf); + + cond_resched(); + + spin_lock_irq(&conf->device_lock); + for (i = 0; i < batch_size; i++) { + hash = batch[i]->hash_lock_index; + __release_stripe(conf, batch[i], &temp_inactive_list[hash]); + } + return batch_size; +} + +static void raid5_do_work(struct work_struct *work) +{ + struct r5worker *worker = container_of(work, struct r5worker, work); + struct r5worker_group *group = worker->group; + struct r5conf *conf = group->conf; + struct mddev *mddev = conf->mddev; + int group_id = group - conf->worker_groups; + int handled; + struct blk_plug plug; + + pr_debug("+++ raid5worker active\n"); + + blk_start_plug(&plug); + handled = 0; + spin_lock_irq(&conf->device_lock); + while (1) { + int batch_size, released; + + released = release_stripe_list(conf, worker->temp_inactive_list); + + batch_size = handle_active_stripes(conf, group_id, worker, + worker->temp_inactive_list); + worker->working = false; + if (!batch_size && !released) + break; + handled += batch_size; + wait_event_lock_irq(mddev->sb_wait, + !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags), + conf->device_lock); + } + pr_debug("%d stripes handled\n", handled); + + spin_unlock_irq(&conf->device_lock); + + flush_deferred_bios(conf); + + r5l_flush_stripe_to_raid(conf->log); + + async_tx_issue_pending_all(); + blk_finish_plug(&plug); + + pr_debug("--- raid5worker inactive\n"); +} + +/* + * 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(struct md_thread *thread) +{ + struct mddev *mddev = thread->mddev; + struct r5conf *conf = mddev->private; + int handled; + struct blk_plug plug; + + pr_debug("+++ raid5d active\n"); + + md_check_recovery(mddev); + + blk_start_plug(&plug); + handled = 0; + spin_lock_irq(&conf->device_lock); + while (1) { + struct bio *bio; + int batch_size, released; + unsigned int offset; + + released = release_stripe_list(conf, conf->temp_inactive_list); + if (released) + clear_bit(R5_DID_ALLOC, &conf->cache_state); + + if ( + !list_empty(&conf->bitmap_list)) { + /* Now is a good time to flush some bitmap updates */ + conf->seq_flush++; + spin_unlock_irq(&conf->device_lock); + md_bitmap_unplug(mddev->bitmap); + spin_lock_irq(&conf->device_lock); + conf->seq_write = conf->seq_flush; + activate_bit_delay(conf, conf->temp_inactive_list); + } + raid5_activate_delayed(conf); + + while ((bio = remove_bio_from_retry(conf, &offset))) { + int ok; + spin_unlock_irq(&conf->device_lock); + ok = retry_aligned_read(conf, bio, offset); + spin_lock_irq(&conf->device_lock); + if (!ok) + break; + handled++; + } + + batch_size = handle_active_stripes(conf, ANY_GROUP, NULL, + conf->temp_inactive_list); + if (!batch_size && !released) + break; + handled += batch_size; + + if (mddev->sb_flags & ~(1 << MD_SB_CHANGE_PENDING)) { + spin_unlock_irq(&conf->device_lock); + md_check_recovery(mddev); + spin_lock_irq(&conf->device_lock); + } + } + pr_debug("%d stripes handled\n", handled); + + spin_unlock_irq(&conf->device_lock); + if (test_and_clear_bit(R5_ALLOC_MORE, &conf->cache_state) && + mutex_trylock(&conf->cache_size_mutex)) { + grow_one_stripe(conf, __GFP_NOWARN); + /* Set flag even if allocation failed. This helps + * slow down allocation requests when mem is short + */ + set_bit(R5_DID_ALLOC, &conf->cache_state); + mutex_unlock(&conf->cache_size_mutex); + } + + flush_deferred_bios(conf); + + r5l_flush_stripe_to_raid(conf->log); + + async_tx_issue_pending_all(); + blk_finish_plug(&plug); + + pr_debug("--- raid5d inactive\n"); +} + +static ssize_t +raid5_show_stripe_cache_size(struct mddev *mddev, char *page) +{ + struct r5conf *conf; + int ret = 0; + spin_lock(&mddev->lock); + conf = mddev->private; + if (conf) + ret = sprintf(page, "%d\n", conf->min_nr_stripes); + spin_unlock(&mddev->lock); + return ret; +} + +int +raid5_set_cache_size(struct mddev *mddev, int size) +{ + int result = 0; + struct r5conf *conf = mddev->private; + + if (size <= 16 || size > 32768) + return -EINVAL; + + conf->min_nr_stripes = size; + mutex_lock(&conf->cache_size_mutex); + while (size < conf->max_nr_stripes && + drop_one_stripe(conf)) + ; + mutex_unlock(&conf->cache_size_mutex); + + md_allow_write(mddev); + + mutex_lock(&conf->cache_size_mutex); + while (size > conf->max_nr_stripes) + if (!grow_one_stripe(conf, GFP_KERNEL)) { + conf->min_nr_stripes = conf->max_nr_stripes; + result = -ENOMEM; + break; + } + mutex_unlock(&conf->cache_size_mutex); + + return result; +} +EXPORT_SYMBOL(raid5_set_cache_size); + +static ssize_t +raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len) +{ + struct r5conf *conf; + unsigned long new; + int err; + + if (len >= PAGE_SIZE) + return -EINVAL; + if (kstrtoul(page, 10, &new)) + return -EINVAL; + err = mddev_lock(mddev); + if (err) + return err; + conf = mddev->private; + if (!conf) + err = -ENODEV; + else + err = raid5_set_cache_size(mddev, new); + mddev_unlock(mddev); + + return err ?: 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_rmw_level(struct mddev *mddev, char *page) +{ + struct r5conf *conf = mddev->private; + if (conf) + return sprintf(page, "%d\n", conf->rmw_level); + else + return 0; +} + +static ssize_t +raid5_store_rmw_level(struct mddev *mddev, const char *page, size_t len) +{ + struct r5conf *conf = mddev->private; + unsigned long new; + + if (!conf) + return -ENODEV; + + if (len >= PAGE_SIZE) + return -EINVAL; + + if (kstrtoul(page, 10, &new)) + return -EINVAL; + + if (new != PARITY_DISABLE_RMW && !raid6_call.xor_syndrome) + return -EINVAL; + + if (new != PARITY_DISABLE_RMW && + new != PARITY_ENABLE_RMW && + new != PARITY_PREFER_RMW) + return -EINVAL; + + conf->rmw_level = new; + return len; +} + +static struct md_sysfs_entry +raid5_rmw_level = __ATTR(rmw_level, S_IRUGO | S_IWUSR, + raid5_show_rmw_level, + raid5_store_rmw_level); + + +static ssize_t +raid5_show_preread_threshold(struct mddev *mddev, char *page) +{ + struct r5conf *conf; + int ret = 0; + spin_lock(&mddev->lock); + conf = mddev->private; + if (conf) + ret = sprintf(page, "%d\n", conf->bypass_threshold); + spin_unlock(&mddev->lock); + return ret; +} + +static ssize_t +raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len) +{ + struct r5conf *conf; + unsigned long new; + int err; + + if (len >= PAGE_SIZE) + return -EINVAL; + if (kstrtoul(page, 10, &new)) + return -EINVAL; + + err = mddev_lock(mddev); + if (err) + return err; + conf = mddev->private; + if (!conf) + err = -ENODEV; + else if (new > conf->min_nr_stripes) + err = -EINVAL; + else + conf->bypass_threshold = new; + mddev_unlock(mddev); + return err ?: 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 +raid5_show_skip_copy(struct mddev *mddev, char *page) +{ + struct r5conf *conf; + int ret = 0; + spin_lock(&mddev->lock); + conf = mddev->private; + if (conf) + ret = sprintf(page, "%d\n", conf->skip_copy); + spin_unlock(&mddev->lock); + return ret; +} + +static ssize_t +raid5_store_skip_copy(struct mddev *mddev, const char *page, size_t len) +{ + struct r5conf *conf; + unsigned long new; + int err; + + if (len >= PAGE_SIZE) + return -EINVAL; + if (kstrtoul(page, 10, &new)) + return -EINVAL; + new = !!new; + + err = mddev_lock(mddev); + if (err) + return err; + conf = mddev->private; + if (!conf) + err = -ENODEV; + else if (new != conf->skip_copy) { + mddev_suspend(mddev); + conf->skip_copy = new; + if (new) + mddev->queue->backing_dev_info->capabilities |= + BDI_CAP_STABLE_WRITES; + else + mddev->queue->backing_dev_info->capabilities &= + ~BDI_CAP_STABLE_WRITES; + mddev_resume(mddev); + } + mddev_unlock(mddev); + return err ?: len; +} + +static struct md_sysfs_entry +raid5_skip_copy = __ATTR(skip_copy, S_IRUGO | S_IWUSR, + raid5_show_skip_copy, + raid5_store_skip_copy); + +static ssize_t +stripe_cache_active_show(struct mddev *mddev, char *page) +{ + struct r5conf *conf = mddev->private; + 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 ssize_t +raid5_show_group_thread_cnt(struct mddev *mddev, char *page) +{ + struct r5conf *conf; + int ret = 0; + spin_lock(&mddev->lock); + conf = mddev->private; + if (conf) + ret = sprintf(page, "%d\n", conf->worker_cnt_per_group); + spin_unlock(&mddev->lock); + return ret; +} + +static int alloc_thread_groups(struct r5conf *conf, int cnt, + int *group_cnt, + int *worker_cnt_per_group, + struct r5worker_group **worker_groups); +static ssize_t +raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len) +{ + struct r5conf *conf; + unsigned int new; + int err; + struct r5worker_group *new_groups, *old_groups; + int group_cnt, worker_cnt_per_group; + + if (len >= PAGE_SIZE) + return -EINVAL; + if (kstrtouint(page, 10, &new)) + return -EINVAL; + /* 8192 should be big enough */ + if (new > 8192) + return -EINVAL; + + err = mddev_lock(mddev); + if (err) + return err; + conf = mddev->private; + if (!conf) + err = -ENODEV; + else if (new != conf->worker_cnt_per_group) { + mddev_suspend(mddev); + + old_groups = conf->worker_groups; + if (old_groups) + flush_workqueue(raid5_wq); + + err = alloc_thread_groups(conf, new, + &group_cnt, &worker_cnt_per_group, + &new_groups); + if (!err) { + spin_lock_irq(&conf->device_lock); + conf->group_cnt = group_cnt; + conf->worker_cnt_per_group = worker_cnt_per_group; + conf->worker_groups = new_groups; + spin_unlock_irq(&conf->device_lock); + + if (old_groups) + kfree(old_groups[0].workers); + kfree(old_groups); + } + mddev_resume(mddev); + } + mddev_unlock(mddev); + + return err ?: len; +} + +static struct md_sysfs_entry +raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR, + raid5_show_group_thread_cnt, + raid5_store_group_thread_cnt); + +static struct attribute *raid5_attrs[] = { + &raid5_stripecache_size.attr, + &raid5_stripecache_active.attr, + &raid5_preread_bypass_threshold.attr, + &raid5_group_thread_cnt.attr, + &raid5_skip_copy.attr, + &raid5_rmw_level.attr, + &r5c_journal_mode.attr, + NULL, +}; +static struct attribute_group raid5_attrs_group = { + .name = NULL, + .attrs = raid5_attrs, +}; + +static int alloc_thread_groups(struct r5conf *conf, int cnt, + int *group_cnt, + int *worker_cnt_per_group, + struct r5worker_group **worker_groups) +{ + int i, j, k; + ssize_t size; + struct r5worker *workers; + + *worker_cnt_per_group = cnt; + if (cnt == 0) { + *group_cnt = 0; + *worker_groups = NULL; + return 0; + } + *group_cnt = num_possible_nodes(); + size = sizeof(struct r5worker) * cnt; + workers = kcalloc(size, *group_cnt, GFP_NOIO); + *worker_groups = kcalloc(*group_cnt, sizeof(struct r5worker_group), + GFP_NOIO); + if (!*worker_groups || !workers) { + kfree(workers); + kfree(*worker_groups); + return -ENOMEM; + } + + for (i = 0; i < *group_cnt; i++) { + struct r5worker_group *group; + + group = &(*worker_groups)[i]; + INIT_LIST_HEAD(&group->handle_list); + INIT_LIST_HEAD(&group->loprio_list); + group->conf = conf; + group->workers = workers + i * cnt; + + for (j = 0; j < cnt; j++) { + struct r5worker *worker = group->workers + j; + worker->group = group; + INIT_WORK(&worker->work, raid5_do_work); + + for (k = 0; k < NR_STRIPE_HASH_LOCKS; k++) + INIT_LIST_HEAD(worker->temp_inactive_list + k); + } + } + + return 0; +} + +static void free_thread_groups(struct r5conf *conf) +{ + if (conf->worker_groups) + kfree(conf->worker_groups[0].workers); + kfree(conf->worker_groups); + conf->worker_groups = NULL; +} + +static sector_t +raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks) +{ + struct r5conf *conf = mddev->private; + + if (!sectors) + sectors = mddev->dev_sectors; + if (!raid_disks) + /* size is defined by the smallest of previous and new size */ + raid_disks = min(conf->raid_disks, conf->previous_raid_disks); + + sectors &= ~((sector_t)conf->chunk_sectors - 1); + sectors &= ~((sector_t)conf->prev_chunk_sectors - 1); + return sectors * (raid_disks - conf->max_degraded); +} + +static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu) +{ + safe_put_page(percpu->spare_page); + if (percpu->scribble) + flex_array_free(percpu->scribble); + percpu->spare_page = NULL; + percpu->scribble = NULL; +} + +static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu) +{ + if (conf->level == 6 && !percpu->spare_page) + percpu->spare_page = alloc_page(GFP_KERNEL); + if (!percpu->scribble) + percpu->scribble = scribble_alloc(max(conf->raid_disks, + conf->previous_raid_disks), + max(conf->chunk_sectors, + conf->prev_chunk_sectors) + / STRIPE_SECTORS, + GFP_KERNEL); + + if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) { + free_scratch_buffer(conf, percpu); + return -ENOMEM; + } + + return 0; +} + +static int raid456_cpu_dead(unsigned int cpu, struct hlist_node *node) +{ + struct r5conf *conf = hlist_entry_safe(node, struct r5conf, node); + + free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu)); + return 0; +} + +static void raid5_free_percpu(struct r5conf *conf) +{ + if (!conf->percpu) + return; + + cpuhp_state_remove_instance(CPUHP_MD_RAID5_PREPARE, &conf->node); + free_percpu(conf->percpu); +} + +static void free_conf(struct r5conf *conf) +{ + int i; + + log_exit(conf); + + unregister_shrinker(&conf->shrinker); + free_thread_groups(conf); + shrink_stripes(conf); + raid5_free_percpu(conf); + for (i = 0; i < conf->pool_size; i++) + if (conf->disks[i].extra_page) + put_page(conf->disks[i].extra_page); + kfree(conf->disks); + bioset_exit(&conf->bio_split); + kfree(conf->stripe_hashtbl); + kfree(conf->pending_data); + kfree(conf); +} + +static int raid456_cpu_up_prepare(unsigned int cpu, struct hlist_node *node) +{ + struct r5conf *conf = hlist_entry_safe(node, struct r5conf, node); + struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu); + + if (alloc_scratch_buffer(conf, percpu)) { + pr_warn("%s: failed memory allocation for cpu%u\n", + __func__, cpu); + return -ENOMEM; + } + return 0; +} + +static int raid5_alloc_percpu(struct r5conf *conf) +{ + int err = 0; + + conf->percpu = alloc_percpu(struct raid5_percpu); + if (!conf->percpu) + return -ENOMEM; + + err = cpuhp_state_add_instance(CPUHP_MD_RAID5_PREPARE, &conf->node); + if (!err) { + conf->scribble_disks = max(conf->raid_disks, + conf->previous_raid_disks); + conf->scribble_sectors = max(conf->chunk_sectors, + conf->prev_chunk_sectors); + } + return err; +} + +static unsigned long raid5_cache_scan(struct shrinker *shrink, + struct shrink_control *sc) +{ + struct r5conf *conf = container_of(shrink, struct r5conf, shrinker); + unsigned long ret = SHRINK_STOP; + + if (mutex_trylock(&conf->cache_size_mutex)) { + ret= 0; + while (ret < sc->nr_to_scan && + conf->max_nr_stripes > conf->min_nr_stripes) { + if (drop_one_stripe(conf) == 0) { + ret = SHRINK_STOP; + break; + } + ret++; + } + mutex_unlock(&conf->cache_size_mutex); + } + return ret; +} + +static unsigned long raid5_cache_count(struct shrinker *shrink, + struct shrink_control *sc) +{ + struct r5conf *conf = container_of(shrink, struct r5conf, shrinker); + + if (conf->max_nr_stripes < conf->min_nr_stripes) + /* unlikely, but not impossible */ + return 0; + return conf->max_nr_stripes - conf->min_nr_stripes; +} + +static struct r5conf *setup_conf(struct mddev *mddev) +{ + struct r5conf *conf; + int raid_disk, memory, max_disks; + struct md_rdev *rdev; + struct disk_info *disk; + char pers_name[6]; + int i; + int group_cnt, worker_cnt_per_group; + struct r5worker_group *new_group; + int ret; + + if (mddev->new_level != 5 + && mddev->new_level != 4 + && mddev->new_level != 6) { + pr_warn("md/raid:%s: raid level not set to 4/5/6 (%d)\n", + mdname(mddev), mddev->new_level); + return ERR_PTR(-EIO); + } + if ((mddev->new_level == 5 + && !algorithm_valid_raid5(mddev->new_layout)) || + (mddev->new_level == 6 + && !algorithm_valid_raid6(mddev->new_layout))) { + pr_warn("md/raid:%s: layout %d not supported\n", + mdname(mddev), mddev->new_layout); + return ERR_PTR(-EIO); + } + if (mddev->new_level == 6 && mddev->raid_disks < 4) { + pr_warn("md/raid:%s: not enough configured devices (%d, minimum 4)\n", + mdname(mddev), mddev->raid_disks); + return ERR_PTR(-EINVAL); + } + + if (!mddev->new_chunk_sectors || + (mddev->new_chunk_sectors << 9) % PAGE_SIZE || + !is_power_of_2(mddev->new_chunk_sectors)) { + pr_warn("md/raid:%s: invalid chunk size %d\n", + mdname(mddev), mddev->new_chunk_sectors << 9); + return ERR_PTR(-EINVAL); + } + + conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL); + if (conf == NULL) + goto abort; + INIT_LIST_HEAD(&conf->free_list); + INIT_LIST_HEAD(&conf->pending_list); + conf->pending_data = kcalloc(PENDING_IO_MAX, + sizeof(struct r5pending_data), + GFP_KERNEL); + if (!conf->pending_data) + goto abort; + for (i = 0; i < PENDING_IO_MAX; i++) + list_add(&conf->pending_data[i].sibling, &conf->free_list); + /* Don't enable multi-threading by default*/ + if (!alloc_thread_groups(conf, 0, &group_cnt, &worker_cnt_per_group, + &new_group)) { + conf->group_cnt = group_cnt; + conf->worker_cnt_per_group = worker_cnt_per_group; + conf->worker_groups = new_group; + } else + goto abort; + spin_lock_init(&conf->device_lock); + seqcount_init(&conf->gen_lock); + mutex_init(&conf->cache_size_mutex); + init_waitqueue_head(&conf->wait_for_quiescent); + init_waitqueue_head(&conf->wait_for_stripe); + init_waitqueue_head(&conf->wait_for_overlap); + INIT_LIST_HEAD(&conf->handle_list); + INIT_LIST_HEAD(&conf->loprio_list); + INIT_LIST_HEAD(&conf->hold_list); + INIT_LIST_HEAD(&conf->delayed_list); + INIT_LIST_HEAD(&conf->bitmap_list); + init_llist_head(&conf->released_stripes); + atomic_set(&conf->active_stripes, 0); + atomic_set(&conf->preread_active_stripes, 0); + atomic_set(&conf->active_aligned_reads, 0); + spin_lock_init(&conf->pending_bios_lock); + conf->batch_bio_dispatch = true; + rdev_for_each(rdev, mddev) { + if (test_bit(Journal, &rdev->flags)) + continue; + if (blk_queue_nonrot(bdev_get_queue(rdev->bdev))) { + conf->batch_bio_dispatch = false; + break; + } + } + + conf->bypass_threshold = BYPASS_THRESHOLD; + conf->recovery_disabled = mddev->recovery_disabled - 1; + + conf->raid_disks = mddev->raid_disks; + if (mddev->reshape_position == MaxSector) + conf->previous_raid_disks = mddev->raid_disks; + else + conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; + max_disks = max(conf->raid_disks, conf->previous_raid_disks); + + conf->disks = kcalloc(max_disks, sizeof(struct disk_info), + GFP_KERNEL); + + if (!conf->disks) + goto abort; + + for (i = 0; i < max_disks; i++) { + conf->disks[i].extra_page = alloc_page(GFP_KERNEL); + if (!conf->disks[i].extra_page) + goto abort; + } + + ret = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0); + if (ret) + goto abort; + conf->mddev = mddev; + + if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) + goto abort; + + /* We init hash_locks[0] separately to that it can be used + * as the reference lock in the spin_lock_nest_lock() call + * in lock_all_device_hash_locks_irq in order to convince + * lockdep that we know what we are doing. + */ + spin_lock_init(conf->hash_locks); + for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++) + spin_lock_init(conf->hash_locks + i); + + for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) + INIT_LIST_HEAD(conf->inactive_list + i); + + for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) + INIT_LIST_HEAD(conf->temp_inactive_list + i); + + atomic_set(&conf->r5c_cached_full_stripes, 0); + INIT_LIST_HEAD(&conf->r5c_full_stripe_list); + atomic_set(&conf->r5c_cached_partial_stripes, 0); + INIT_LIST_HEAD(&conf->r5c_partial_stripe_list); + atomic_set(&conf->r5c_flushing_full_stripes, 0); + atomic_set(&conf->r5c_flushing_partial_stripes, 0); + + conf->level = mddev->new_level; + conf->chunk_sectors = mddev->new_chunk_sectors; + if (raid5_alloc_percpu(conf) != 0) + goto abort; + + pr_debug("raid456: run(%s) called.\n", mdname(mddev)); + + rdev_for_each(rdev, mddev) { + raid_disk = rdev->raid_disk; + if (raid_disk >= max_disks + || raid_disk < 0 || test_bit(Journal, &rdev->flags)) + continue; + disk = conf->disks + raid_disk; + + if (test_bit(Replacement, &rdev->flags)) { + if (disk->replacement) + goto abort; + disk->replacement = rdev; + } else { + if (disk->rdev) + goto abort; + disk->rdev = rdev; + } + + if (test_bit(In_sync, &rdev->flags)) { + char b[BDEVNAME_SIZE]; + pr_info("md/raid:%s: device %s operational as raid disk %d\n", + mdname(mddev), bdevname(rdev->bdev, b), raid_disk); + } else if (rdev->saved_raid_disk != raid_disk) + /* Cannot rely on bitmap to complete recovery */ + conf->fullsync = 1; + } + + conf->level = mddev->new_level; + if (conf->level == 6) { + conf->max_degraded = 2; + if (raid6_call.xor_syndrome) + conf->rmw_level = PARITY_ENABLE_RMW; + else + conf->rmw_level = PARITY_DISABLE_RMW; + } else { + conf->max_degraded = 1; + conf->rmw_level = PARITY_ENABLE_RMW; + } + conf->algorithm = mddev->new_layout; + conf->reshape_progress = mddev->reshape_position; + if (conf->reshape_progress != MaxSector) { + conf->prev_chunk_sectors = mddev->chunk_sectors; + conf->prev_algo = mddev->layout; + } else { + conf->prev_chunk_sectors = conf->chunk_sectors; + conf->prev_algo = conf->algorithm; + } + + conf->min_nr_stripes = NR_STRIPES; + if (mddev->reshape_position != MaxSector) { + int stripes = max_t(int, + ((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4, + ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4); + conf->min_nr_stripes = max(NR_STRIPES, stripes); + if (conf->min_nr_stripes != NR_STRIPES) + pr_info("md/raid:%s: force stripe size %d for reshape\n", + mdname(mddev), conf->min_nr_stripes); + } + memory = conf->min_nr_stripes * (sizeof(struct stripe_head) + + max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; + atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS); + if (grow_stripes(conf, conf->min_nr_stripes)) { + pr_warn("md/raid:%s: couldn't allocate %dkB for buffers\n", + mdname(mddev), memory); + goto abort; + } else + pr_debug("md/raid:%s: allocated %dkB\n", mdname(mddev), memory); + /* + * Losing a stripe head costs more than the time to refill it, + * it reduces the queue depth and so can hurt throughput. + * So set it rather large, scaled by number of devices. + */ + conf->shrinker.seeks = DEFAULT_SEEKS * conf->raid_disks * 4; + conf->shrinker.scan_objects = raid5_cache_scan; + conf->shrinker.count_objects = raid5_cache_count; + conf->shrinker.batch = 128; + conf->shrinker.flags = 0; + if (register_shrinker(&conf->shrinker)) { + pr_warn("md/raid:%s: couldn't register shrinker.\n", + mdname(mddev)); + goto abort; + } + + sprintf(pers_name, "raid%d", mddev->new_level); + conf->thread = md_register_thread(raid5d, mddev, pers_name); + if (!conf->thread) { + pr_warn("md/raid:%s: couldn't allocate thread.\n", + mdname(mddev)); + goto abort; + } + + return conf; + + abort: + if (conf) { + free_conf(conf); + return ERR_PTR(-EIO); + } else + return ERR_PTR(-ENOMEM); +} + +static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded) +{ + switch (algo) { + case ALGORITHM_PARITY_0: + if (raid_disk < max_degraded) + return 1; + break; + case ALGORITHM_PARITY_N: + if (raid_disk >= raid_disks - max_degraded) + return 1; + break; + case ALGORITHM_PARITY_0_6: + if (raid_disk == 0 || + raid_disk == raid_disks - 1) + return 1; + break; + case ALGORITHM_LEFT_ASYMMETRIC_6: + case ALGORITHM_RIGHT_ASYMMETRIC_6: + case ALGORITHM_LEFT_SYMMETRIC_6: + case ALGORITHM_RIGHT_SYMMETRIC_6: + if (raid_disk == raid_disks - 1) + return 1; + } + return 0; +} + +static int raid5_run(struct mddev *mddev) +{ + struct r5conf *conf; + int working_disks = 0; + int dirty_parity_disks = 0; + struct md_rdev *rdev; + struct md_rdev *journal_dev = NULL; + sector_t reshape_offset = 0; + int i; + long long min_offset_diff = 0; + int first = 1; + + if (mddev_init_writes_pending(mddev) < 0) + return -ENOMEM; + + if (mddev->recovery_cp != MaxSector) + pr_notice("md/raid:%s: not clean -- starting background reconstruction\n", + mdname(mddev)); + + rdev_for_each(rdev, mddev) { + long long diff; + + if (test_bit(Journal, &rdev->flags)) { + journal_dev = rdev; + continue; + } + if (rdev->raid_disk < 0) + continue; + diff = (rdev->new_data_offset - rdev->data_offset); + if (first) { + min_offset_diff = diff; + first = 0; + } else if (mddev->reshape_backwards && + diff < min_offset_diff) + min_offset_diff = diff; + else if (!mddev->reshape_backwards && + diff > min_offset_diff) + min_offset_diff = diff; + } + + if ((test_bit(MD_HAS_JOURNAL, &mddev->flags) || journal_dev) && + (mddev->bitmap_info.offset || mddev->bitmap_info.file)) { + pr_notice("md/raid:%s: array cannot have both journal and bitmap\n", + mdname(mddev)); + return -EINVAL; + } + + if (mddev->reshape_position != MaxSector) { + /* Check that we can continue the reshape. + * Difficulties arise if the stripe we would write to + * next is at or after the stripe we would read from next. + * For a reshape that changes the number of devices, this + * is only possible for a very short time, and mdadm makes + * sure that time appears to have past before assembling + * the array. So we fail if that time hasn't passed. + * For a reshape that keeps the number of devices the same + * mdadm must be monitoring the reshape can keeping the + * critical areas read-only and backed up. It will start + * the array in read-only mode, so we check for that. + */ + sector_t here_new, here_old; + int old_disks; + int max_degraded = (mddev->level == 6 ? 2 : 1); + int chunk_sectors; + int new_data_disks; + + if (journal_dev) { + pr_warn("md/raid:%s: don't support reshape with journal - aborting.\n", + mdname(mddev)); + return -EINVAL; + } + + if (mddev->new_level != mddev->level) { + pr_warn("md/raid:%s: unsupported reshape 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. + * If the chunk sizes are different, then as we perform reshape + * in units of the largest of the two, reshape_position needs + * be a multiple of the largest chunk size times new data disks. + */ + here_new = mddev->reshape_position; + chunk_sectors = max(mddev->chunk_sectors, mddev->new_chunk_sectors); + new_data_disks = mddev->raid_disks - max_degraded; + if (sector_div(here_new, chunk_sectors * new_data_disks)) { + pr_warn("md/raid:%s: reshape_position not on a stripe boundary\n", + mdname(mddev)); + return -EINVAL; + } + reshape_offset = here_new * chunk_sectors; + /* here_new is the stripe we will write to */ + here_old = mddev->reshape_position; + sector_div(here_old, chunk_sectors * (old_disks-max_degraded)); + /* here_old is the first stripe that we might need to read + * from */ + if (mddev->delta_disks == 0) { + /* We cannot be sure it is safe to start an in-place + * reshape. It is only safe if user-space is monitoring + * and taking constant backups. + * mdadm always starts a situation like this in + * readonly mode so it can take control before + * allowing any writes. So just check for that. + */ + if (abs(min_offset_diff) >= mddev->chunk_sectors && + abs(min_offset_diff) >= mddev->new_chunk_sectors) + /* not really in-place - so OK */; + else if (mddev->ro == 0) { + pr_warn("md/raid:%s: in-place reshape must be started in read-only mode - aborting\n", + mdname(mddev)); + return -EINVAL; + } + } else if (mddev->reshape_backwards + ? (here_new * chunk_sectors + min_offset_diff <= + here_old * chunk_sectors) + : (here_new * chunk_sectors >= + here_old * chunk_sectors + (-min_offset_diff))) { + /* Reading from the same stripe as writing to - bad */ + pr_warn("md/raid:%s: reshape_position too early for auto-recovery - aborting.\n", + mdname(mddev)); + return -EINVAL; + } + pr_debug("md/raid:%s: reshape will continue\n", mdname(mddev)); + /* OK, we should be able to continue; */ + } else { + BUG_ON(mddev->level != mddev->new_level); + BUG_ON(mddev->layout != mddev->new_layout); + BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors); + BUG_ON(mddev->delta_disks != 0); + } + + if (test_bit(MD_HAS_JOURNAL, &mddev->flags) && + test_bit(MD_HAS_PPL, &mddev->flags)) { + pr_warn("md/raid:%s: using journal device and PPL not allowed - disabling PPL\n", + mdname(mddev)); + clear_bit(MD_HAS_PPL, &mddev->flags); + clear_bit(MD_HAS_MULTIPLE_PPLS, &mddev->flags); + } + + if (mddev->private == NULL) + conf = setup_conf(mddev); + else + conf = mddev->private; + + if (IS_ERR(conf)) + return PTR_ERR(conf); + + if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) { + if (!journal_dev) { + pr_warn("md/raid:%s: journal disk is missing, force array readonly\n", + mdname(mddev)); + mddev->ro = 1; + set_disk_ro(mddev->gendisk, 1); + } else if (mddev->recovery_cp == MaxSector) + set_bit(MD_JOURNAL_CLEAN, &mddev->flags); + } + + conf->min_offset_diff = min_offset_diff; + mddev->thread = conf->thread; + conf->thread = NULL; + mddev->private = conf; + + for (i = 0; i < conf->raid_disks && conf->previous_raid_disks; + i++) { + rdev = conf->disks[i].rdev; + if (!rdev && conf->disks[i].replacement) { + /* The replacement is all we have yet */ + rdev = conf->disks[i].replacement; + conf->disks[i].replacement = NULL; + clear_bit(Replacement, &rdev->flags); + conf->disks[i].rdev = rdev; + } + if (!rdev) + continue; + if (conf->disks[i].replacement && + conf->reshape_progress != MaxSector) { + /* replacements and reshape simply do not mix. */ + pr_warn("md: cannot handle concurrent replacement and reshape.\n"); + goto abort; + } + if (test_bit(In_sync, &rdev->flags)) { + working_disks++; + continue; + } + /* This disc is not fully in-sync. However if it + * just stored parity (beyond the recovery_offset), + * when we don't need to be concerned about the + * array being dirty. + * When reshape goes 'backwards', we never have + * partially completed devices, so we only need + * to worry about reshape going forwards. + */ + /* Hack because v0.91 doesn't store recovery_offset properly. */ + if (mddev->major_version == 0 && + mddev->minor_version > 90) + rdev->recovery_offset = reshape_offset; + + if (rdev->recovery_offset < reshape_offset) { + /* We need to check old and new layout */ + if (!only_parity(rdev->raid_disk, + conf->algorithm, + conf->raid_disks, + conf->max_degraded)) + continue; + } + if (!only_parity(rdev->raid_disk, + conf->prev_algo, + conf->previous_raid_disks, + conf->max_degraded)) + continue; + dirty_parity_disks++; + } + + /* + * 0 for a fully functional array, 1 or 2 for a degraded array. + */ + mddev->degraded = raid5_calc_degraded(conf); + + if (has_failed(conf)) { + pr_crit("md/raid:%s: not enough operational devices (%d/%d failed)\n", + mdname(mddev), mddev->degraded, conf->raid_disks); + goto abort; + } + + /* device size must be a multiple of chunk size */ + mddev->dev_sectors &= ~(mddev->chunk_sectors - 1); + mddev->resync_max_sectors = mddev->dev_sectors; + + if (mddev->degraded > dirty_parity_disks && + mddev->recovery_cp != MaxSector) { + if (test_bit(MD_HAS_PPL, &mddev->flags)) + pr_crit("md/raid:%s: starting dirty degraded array with PPL.\n", + mdname(mddev)); + else if (mddev->ok_start_degraded) + pr_crit("md/raid:%s: starting dirty degraded array - data corruption possible.\n", + mdname(mddev)); + else { + pr_crit("md/raid:%s: cannot start dirty degraded array.\n", + mdname(mddev)); + goto abort; + } + } + + pr_info("md/raid:%s: raid level %d active with %d out of %d devices, algorithm %d\n", + mdname(mddev), conf->level, + mddev->raid_disks-mddev->degraded, mddev->raid_disks, + mddev->new_layout); + + print_raid5_conf(conf); + + if (conf->reshape_progress != MaxSector) { + conf->reshape_safe = conf->reshape_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, + "reshape"); + if (!mddev->sync_thread) + goto abort; + } + + /* Ok, everything is just fine now */ + if (mddev->to_remove == &raid5_attrs_group) + mddev->to_remove = NULL; + else if (mddev->kobj.sd && + sysfs_create_group(&mddev->kobj, &raid5_attrs_group)) + pr_warn("raid5: failed to create sysfs attributes for %s\n", + mdname(mddev)); + md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); + + if (mddev->queue) { + int chunk_size; + /* 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_sectors << 9) / PAGE_SIZE); + if (mddev->queue->backing_dev_info->ra_pages < 2 * stripe) + mddev->queue->backing_dev_info->ra_pages = 2 * stripe; + + chunk_size = mddev->chunk_sectors << 9; + blk_queue_io_min(mddev->queue, chunk_size); + blk_queue_io_opt(mddev->queue, chunk_size * + (conf->raid_disks - conf->max_degraded)); + mddev->queue->limits.raid_partial_stripes_expensive = 1; + /* + * We can only discard a whole stripe. It doesn't make sense to + * discard data disk but write parity disk + */ + stripe = stripe * PAGE_SIZE; + /* Round up to power of 2, as discard handling + * currently assumes that */ + while ((stripe-1) & stripe) + stripe = (stripe | (stripe-1)) + 1; + mddev->queue->limits.discard_alignment = stripe; + mddev->queue->limits.discard_granularity = stripe; + + blk_queue_max_write_same_sectors(mddev->queue, 0); + blk_queue_max_write_zeroes_sectors(mddev->queue, 0); + + rdev_for_each(rdev, mddev) { + disk_stack_limits(mddev->gendisk, rdev->bdev, + rdev->data_offset << 9); + disk_stack_limits(mddev->gendisk, rdev->bdev, + rdev->new_data_offset << 9); + } + + /* + * zeroing is required, otherwise data + * could be lost. Consider a scenario: discard a stripe + * (the stripe could be inconsistent if + * discard_zeroes_data is 0); write one disk of the + * stripe (the stripe could be inconsistent again + * depending on which disks are used to calculate + * parity); the disk is broken; The stripe data of this + * disk is lost. + * + * We only allow DISCARD if the sysadmin has confirmed that + * only safe devices are in use by setting a module parameter. + * A better idea might be to turn DISCARD into WRITE_ZEROES + * requests, as that is required to be safe. + */ + if (devices_handle_discard_safely && + mddev->queue->limits.max_discard_sectors >= (stripe >> 9) && + mddev->queue->limits.discard_granularity >= stripe) + blk_queue_flag_set(QUEUE_FLAG_DISCARD, + mddev->queue); + else + blk_queue_flag_clear(QUEUE_FLAG_DISCARD, + mddev->queue); + + blk_queue_max_hw_sectors(mddev->queue, UINT_MAX); + } + + if (log_init(conf, journal_dev, raid5_has_ppl(conf))) + goto abort; + + return 0; +abort: + md_unregister_thread(&mddev->thread); + print_raid5_conf(conf); + free_conf(conf); + mddev->private = NULL; + pr_warn("md/raid:%s: failed to run raid set.\n", mdname(mddev)); + return -EIO; +} + +static void raid5_free(struct mddev *mddev, void *priv) +{ + struct r5conf *conf = priv; + + free_conf(conf); + mddev->to_remove = &raid5_attrs_group; +} + +static void raid5_status(struct seq_file *seq, struct mddev *mddev) +{ + struct r5conf *conf = mddev->private; + int i; + + seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level, + conf->chunk_sectors / 2, mddev->layout); + seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); + rcu_read_lock(); + for (i = 0; i < conf->raid_disks; i++) { + struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); + seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); + } + rcu_read_unlock(); + seq_printf (seq, "]"); +} + +static void print_raid5_conf (struct r5conf *conf) +{ + int i; + struct disk_info *tmp; + + pr_debug("RAID conf printout:\n"); + if (!conf) { + pr_debug("(conf==NULL)\n"); + return; + } + pr_debug(" --- level:%d rd:%d wd:%d\n", conf->level, + 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) + pr_debug(" disk %d, o:%d, dev:%s\n", + i, !test_bit(Faulty, &tmp->rdev->flags), + bdevname(tmp->rdev->bdev, b)); + } +} + +static int raid5_spare_active(struct mddev *mddev) +{ + int i; + struct r5conf *conf = mddev->private; + struct disk_info *tmp; + int count = 0; + unsigned long flags; + + for (i = 0; i < conf->raid_disks; i++) { + tmp = conf->disks + i; + if (tmp->replacement + && tmp->replacement->recovery_offset == MaxSector + && !test_bit(Faulty, &tmp->replacement->flags) + && !test_and_set_bit(In_sync, &tmp->replacement->flags)) { + /* Replacement has just become active. */ + if (!tmp->rdev + || !test_and_clear_bit(In_sync, &tmp->rdev->flags)) + count++; + if (tmp->rdev) { + /* Replaced device not technically faulty, + * but we need to be sure it gets removed + * and never re-added. + */ + set_bit(Faulty, &tmp->rdev->flags); + sysfs_notify_dirent_safe( + tmp->rdev->sysfs_state); + } + sysfs_notify_dirent_safe(tmp->replacement->sysfs_state); + } else if (tmp->rdev + && tmp->rdev->recovery_offset == MaxSector + && !test_bit(Faulty, &tmp->rdev->flags) + && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { + count++; + sysfs_notify_dirent_safe(tmp->rdev->sysfs_state); + } + } + spin_lock_irqsave(&conf->device_lock, flags); + mddev->degraded = raid5_calc_degraded(conf); + spin_unlock_irqrestore(&conf->device_lock, flags); + print_raid5_conf(conf); + return count; +} + +static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev) +{ + struct r5conf *conf = mddev->private; + int err = 0; + int number = rdev->raid_disk; + struct md_rdev **rdevp; + struct disk_info *p = conf->disks + number; + + print_raid5_conf(conf); + if (test_bit(Journal, &rdev->flags) && conf->log) { + /* + * we can't wait pending write here, as this is called in + * raid5d, wait will deadlock. + * neilb: there is no locking about new writes here, + * so this cannot be safe. + */ + if (atomic_read(&conf->active_stripes) || + atomic_read(&conf->r5c_cached_full_stripes) || + atomic_read(&conf->r5c_cached_partial_stripes)) { + return -EBUSY; + } + log_exit(conf); + return 0; + } + if (rdev == p->rdev) + rdevp = &p->rdev; + else if (rdev == p->replacement) + rdevp = &p->replacement; + else + return 0; + + if (number >= conf->raid_disks && + conf->reshape_progress == MaxSector) + clear_bit(In_sync, &rdev->flags); + + 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->recovery_disabled != conf->recovery_disabled && + !has_failed(conf) && + (!p->replacement || p->replacement == rdev) && + number < conf->raid_disks) { + err = -EBUSY; + goto abort; + } + *rdevp = NULL; + if (!test_bit(RemoveSynchronized, &rdev->flags)) { + synchronize_rcu(); + if (atomic_read(&rdev->nr_pending)) { + /* lost the race, try later */ + err = -EBUSY; + *rdevp = rdev; + } + } + if (!err) { + err = log_modify(conf, rdev, false); + if (err) + goto abort; + } + if (p->replacement) { + /* We must have just cleared 'rdev' */ + p->rdev = p->replacement; + clear_bit(Replacement, &p->replacement->flags); + smp_mb(); /* Make sure other CPUs may see both as identical + * but will never see neither - if they are careful + */ + p->replacement = NULL; + + if (!err) + err = log_modify(conf, p->rdev, true); + } + + clear_bit(WantReplacement, &rdev->flags); +abort: + + print_raid5_conf(conf); + return err; +} + +static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev) +{ + struct r5conf *conf = mddev->private; + int ret, err = -EEXIST; + int disk; + struct disk_info *p; + int first = 0; + int last = conf->raid_disks - 1; + + if (test_bit(Journal, &rdev->flags)) { + if (conf->log) + return -EBUSY; + + rdev->raid_disk = 0; + /* + * The array is in readonly mode if journal is missing, so no + * write requests running. We should be safe + */ + ret = log_init(conf, rdev, false); + if (ret) + return ret; + + ret = r5l_start(conf->log); + if (ret) + return ret; + + return 0; + } + if (mddev->recovery_disabled == conf->recovery_disabled) + return -EBUSY; + + if (rdev->saved_raid_disk < 0 && has_failed(conf)) + /* 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) + first = rdev->saved_raid_disk; + + for (disk = first; disk <= last; disk++) { + p = conf->disks + disk; + if (p->rdev == NULL) { + clear_bit(In_sync, &rdev->flags); + rdev->raid_disk = disk; + if (rdev->saved_raid_disk != disk) + conf->fullsync = 1; + rcu_assign_pointer(p->rdev, rdev); + + err = log_modify(conf, rdev, true); + + goto out; + } + } + for (disk = first; disk <= last; disk++) { + p = conf->disks + disk; + if (test_bit(WantReplacement, &p->rdev->flags) && + p->replacement == NULL) { + clear_bit(In_sync, &rdev->flags); + set_bit(Replacement, &rdev->flags); + rdev->raid_disk = disk; + err = 0; + conf->fullsync = 1; + rcu_assign_pointer(p->replacement, rdev); + break; + } + } +out: + print_raid5_conf(conf); + return err; +} + +static int raid5_resize(struct mddev *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. + */ + sector_t newsize; + struct r5conf *conf = mddev->private; + + if (raid5_has_log(conf) || raid5_has_ppl(conf)) + return -EINVAL; + sectors &= ~((sector_t)conf->chunk_sectors - 1); + newsize = raid5_size(mddev, sectors, mddev->raid_disks); + if (mddev->external_size && + mddev->array_sectors > newsize) + return -EINVAL; + if (mddev->bitmap) { + int ret = md_bitmap_resize(mddev->bitmap, sectors, 0, 0); + if (ret) + return ret; + } + md_set_array_sectors(mddev, newsize); + if (sectors > mddev->dev_sectors && + mddev->recovery_cp > mddev->dev_sectors) { + mddev->recovery_cp = mddev->dev_sectors; + set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + } + mddev->dev_sectors = sectors; + mddev->resync_max_sectors = sectors; + return 0; +} + +static int check_stripe_cache(struct mddev *mddev) +{ + /* 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. + */ + struct r5conf *conf = mddev->private; + if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4 + > conf->min_nr_stripes || + ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4 + > conf->min_nr_stripes) { + pr_warn("md/raid:%s: reshape: not enough stripes. Needed %lu\n", + mdname(mddev), + ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9) + / STRIPE_SIZE)*4); + return 0; + } + return 1; +} + +static int check_reshape(struct mddev *mddev) +{ + struct r5conf *conf = mddev->private; + + if (raid5_has_log(conf) || raid5_has_ppl(conf)) + return -EINVAL; + if (mddev->delta_disks == 0 && + mddev->new_layout == mddev->layout && + mddev->new_chunk_sectors == mddev->chunk_sectors) + return 0; /* nothing to do */ + if (has_failed(conf)) + return -EINVAL; + if (mddev->delta_disks < 0 && mddev->reshape_position == MaxSector) { + /* We might be able to shrink, but the devices must + * be made bigger first. + * For raid6, 4 is the minimum size. + * Otherwise 2 is the minimum + */ + int min = 2; + if (mddev->level == 6) + min = 4; + if (mddev->raid_disks + mddev->delta_disks < min) + return -EINVAL; + } + + if (!check_stripe_cache(mddev)) + return -ENOSPC; + + if (mddev->new_chunk_sectors > mddev->chunk_sectors || + mddev->delta_disks > 0) + if (resize_chunks(conf, + conf->previous_raid_disks + + max(0, mddev->delta_disks), + max(mddev->new_chunk_sectors, + mddev->chunk_sectors) + ) < 0) + return -ENOMEM; + + if (conf->previous_raid_disks + mddev->delta_disks <= conf->pool_size) + return 0; /* never bother to shrink */ + return resize_stripes(conf, (conf->previous_raid_disks + + mddev->delta_disks)); +} + +static int raid5_start_reshape(struct mddev *mddev) +{ + struct r5conf *conf = mddev->private; + struct md_rdev *rdev; + int spares = 0; + unsigned long flags; + + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) + return -EBUSY; + + if (!check_stripe_cache(mddev)) + return -ENOSPC; + + if (has_failed(conf)) + return -EINVAL; + + rdev_for_each(rdev, mddev) { + if (!test_bit(In_sync, &rdev->flags) + && !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; + + /* Refuse to reduce size of the array. Any reductions in + * array size must be through explicit setting of array_size + * attribute. + */ + if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks) + < mddev->array_sectors) { + pr_warn("md/raid:%s: array size must be reduced before number of disks\n", + mdname(mddev)); + return -EINVAL; + } + + atomic_set(&conf->reshape_stripes, 0); + spin_lock_irq(&conf->device_lock); + write_seqcount_begin(&conf->gen_lock); + conf->previous_raid_disks = conf->raid_disks; + conf->raid_disks += mddev->delta_disks; + conf->prev_chunk_sectors = conf->chunk_sectors; + conf->chunk_sectors = mddev->new_chunk_sectors; + conf->prev_algo = conf->algorithm; + conf->algorithm = mddev->new_layout; + conf->generation++; + /* Code that selects data_offset needs to see the generation update + * if reshape_progress has been set - so a memory barrier needed. + */ + smp_mb(); + if (mddev->reshape_backwards) + conf->reshape_progress = raid5_size(mddev, 0, 0); + else + conf->reshape_progress = 0; + conf->reshape_safe = conf->reshape_progress; + write_seqcount_end(&conf->gen_lock); + spin_unlock_irq(&conf->device_lock); + + /* Now make sure any requests that proceeded on the assumption + * the reshape wasn't running - like Discard or Read - have + * completed. + */ + mddev_suspend(mddev); + mddev_resume(mddev); + + /* Add some new drives, as many as will fit. + * We know there are enough to make the newly sized array work. + * Don't add devices if we are reducing the number of + * devices in the array. This is because it is not possible + * to correctly record the "partially reconstructed" state of + * such devices during the reshape and confusion could result. + */ + if (mddev->delta_disks >= 0) { + rdev_for_each(rdev, mddev) + if (rdev->raid_disk < 0 && + !test_bit(Faulty, &rdev->flags)) { + if (raid5_add_disk(mddev, rdev) == 0) { + if (rdev->raid_disk + >= conf->previous_raid_disks) + set_bit(In_sync, &rdev->flags); + else + rdev->recovery_offset = 0; + + if (sysfs_link_rdev(mddev, rdev)) + /* Failure here is OK */; + } + } else if (rdev->raid_disk >= conf->previous_raid_disks + && !test_bit(Faulty, &rdev->flags)) { + /* This is a spare that was manually added */ + set_bit(In_sync, &rdev->flags); + } + + /* When a reshape changes the number of devices, + * ->degraded is measured against the larger of the + * pre and post number of devices. + */ + spin_lock_irqsave(&conf->device_lock, flags); + mddev->degraded = raid5_calc_degraded(conf); + spin_unlock_irqrestore(&conf->device_lock, flags); + } + mddev->raid_disks = conf->raid_disks; + mddev->reshape_position = conf->reshape_progress; + set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); + + clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); + clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); + clear_bit(MD_RECOVERY_DONE, &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, + "reshape"); + if (!mddev->sync_thread) { + mddev->recovery = 0; + spin_lock_irq(&conf->device_lock); + write_seqcount_begin(&conf->gen_lock); + mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; + mddev->new_chunk_sectors = + conf->chunk_sectors = conf->prev_chunk_sectors; + mddev->new_layout = conf->algorithm = conf->prev_algo; + rdev_for_each(rdev, mddev) + rdev->new_data_offset = rdev->data_offset; + smp_wmb(); + conf->generation --; + conf->reshape_progress = MaxSector; + mddev->reshape_position = MaxSector; + write_seqcount_end(&conf->gen_lock); + spin_unlock_irq(&conf->device_lock); + return -EAGAIN; + } + conf->reshape_checkpoint = jiffies; + md_wakeup_thread(mddev->sync_thread); + md_new_event(mddev); + return 0; +} + +/* This is called from the reshape thread and should make any + * changes needed in 'conf' + */ +static void end_reshape(struct r5conf *conf) +{ + + if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { + struct md_rdev *rdev; + + spin_lock_irq(&conf->device_lock); + conf->previous_raid_disks = conf->raid_disks; + md_finish_reshape(conf->mddev); + smp_wmb(); + conf->reshape_progress = MaxSector; + conf->mddev->reshape_position = MaxSector; + rdev_for_each(rdev, conf->mddev) + if (rdev->raid_disk >= 0 && + !test_bit(Journal, &rdev->flags) && + !test_bit(In_sync, &rdev->flags)) + rdev->recovery_offset = MaxSector; + spin_unlock_irq(&conf->device_lock); + wake_up(&conf->wait_for_overlap); + + /* read-ahead size must cover two whole stripes, which is + * 2 * (datadisks) * chunksize where 'n' is the number of raid devices + */ + if (conf->mddev->queue) { + int data_disks = conf->raid_disks - conf->max_degraded; + int stripe = data_disks * ((conf->chunk_sectors << 9) + / PAGE_SIZE); + if (conf->mddev->queue->backing_dev_info->ra_pages < 2 * stripe) + conf->mddev->queue->backing_dev_info->ra_pages = 2 * stripe; + } + } +} + +/* This is called from the raid5d thread with mddev_lock held. + * It makes config changes to the device. + */ +static void raid5_finish_reshape(struct mddev *mddev) +{ + struct r5conf *conf = mddev->private; + + if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) { + + if (mddev->delta_disks <= 0) { + int d; + spin_lock_irq(&conf->device_lock); + mddev->degraded = raid5_calc_degraded(conf); + spin_unlock_irq(&conf->device_lock); + for (d = conf->raid_disks ; + d < conf->raid_disks - mddev->delta_disks; + d++) { + struct md_rdev *rdev = conf->disks[d].rdev; + if (rdev) + clear_bit(In_sync, &rdev->flags); + rdev = conf->disks[d].replacement; + if (rdev) + clear_bit(In_sync, &rdev->flags); + } + } + mddev->layout = conf->algorithm; + mddev->chunk_sectors = conf->chunk_sectors; + mddev->reshape_position = MaxSector; + mddev->delta_disks = 0; + mddev->reshape_backwards = 0; + } +} + +static void raid5_quiesce(struct mddev *mddev, int quiesce) +{ + struct r5conf *conf = mddev->private; + + if (quiesce) { + /* stop all writes */ + lock_all_device_hash_locks_irq(conf); + /* '2' tells resync/reshape to pause so that all + * active stripes can drain + */ + r5c_flush_cache(conf, INT_MAX); + conf->quiesce = 2; + wait_event_cmd(conf->wait_for_quiescent, + atomic_read(&conf->active_stripes) == 0 && + atomic_read(&conf->active_aligned_reads) == 0, + unlock_all_device_hash_locks_irq(conf), + lock_all_device_hash_locks_irq(conf)); + conf->quiesce = 1; + unlock_all_device_hash_locks_irq(conf); + /* allow reshape to continue */ + wake_up(&conf->wait_for_overlap); + } else { + /* re-enable writes */ + lock_all_device_hash_locks_irq(conf); + conf->quiesce = 0; + wake_up(&conf->wait_for_quiescent); + wake_up(&conf->wait_for_overlap); + unlock_all_device_hash_locks_irq(conf); + } + log_quiesce(conf, quiesce); +} + +static void *raid45_takeover_raid0(struct mddev *mddev, int level) +{ + struct r0conf *raid0_conf = mddev->private; + sector_t sectors; + + /* for raid0 takeover only one zone is supported */ + if (raid0_conf->nr_strip_zones > 1) { + pr_warn("md/raid:%s: cannot takeover raid0 with more than one zone.\n", + mdname(mddev)); + return ERR_PTR(-EINVAL); + } + + sectors = raid0_conf->strip_zone[0].zone_end; + sector_div(sectors, raid0_conf->strip_zone[0].nb_dev); + mddev->dev_sectors = sectors; + mddev->new_level = level; + mddev->new_layout = ALGORITHM_PARITY_N; + mddev->new_chunk_sectors = mddev->chunk_sectors; + mddev->raid_disks += 1; + mddev->delta_disks = 1; + /* make sure it will be not marked as dirty */ + mddev->recovery_cp = MaxSector; + + return setup_conf(mddev); +} + +static void *raid5_takeover_raid1(struct mddev *mddev) +{ + int chunksect; + void *ret; + + if (mddev->raid_disks != 2 || + mddev->degraded > 1) + return ERR_PTR(-EINVAL); + + /* Should check if there are write-behind devices? */ + + chunksect = 64*2; /* 64K by default */ + + /* The array must be an exact multiple of chunksize */ + while (chunksect && (mddev->array_sectors & (chunksect-1))) + chunksect >>= 1; + + if ((chunksect<<9) < STRIPE_SIZE) + /* array size does not allow a suitable chunk size */ + return ERR_PTR(-EINVAL); + + mddev->new_level = 5; + mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC; + mddev->new_chunk_sectors = chunksect; + + ret = setup_conf(mddev); + if (!IS_ERR(ret)) + mddev_clear_unsupported_flags(mddev, + UNSUPPORTED_MDDEV_FLAGS); + return ret; +} + +static void *raid5_takeover_raid6(struct mddev *mddev) +{ + int new_layout; + + switch (mddev->layout) { + case ALGORITHM_LEFT_ASYMMETRIC_6: + new_layout = ALGORITHM_LEFT_ASYMMETRIC; + break; + case ALGORITHM_RIGHT_ASYMMETRIC_6: + new_layout = ALGORITHM_RIGHT_ASYMMETRIC; + break; + case ALGORITHM_LEFT_SYMMETRIC_6: + new_layout = ALGORITHM_LEFT_SYMMETRIC; + break; + case ALGORITHM_RIGHT_SYMMETRIC_6: + new_layout = ALGORITHM_RIGHT_SYMMETRIC; + break; + case ALGORITHM_PARITY_0_6: + new_layout = ALGORITHM_PARITY_0; + break; + case ALGORITHM_PARITY_N: + new_layout = ALGORITHM_PARITY_N; + break; + default: + return ERR_PTR(-EINVAL); + } + mddev->new_level = 5; + mddev->new_layout = new_layout; + mddev->delta_disks = -1; + mddev->raid_disks -= 1; + return setup_conf(mddev); +} + +static int raid5_check_reshape(struct mddev *mddev) +{ + /* For a 2-drive array, the layout and chunk size can be changed + * immediately as not restriping is needed. + * For larger arrays we record the new value - after validation + * to be used by a reshape pass. + */ + struct r5conf *conf = mddev->private; + int new_chunk = mddev->new_chunk_sectors; + + if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout)) + return -EINVAL; + if (new_chunk > 0) { + if (!is_power_of_2(new_chunk)) + return -EINVAL; + if (new_chunk < (PAGE_SIZE>>9)) + return -EINVAL; + if (mddev->array_sectors & (new_chunk-1)) + /* not factor of array size */ + return -EINVAL; + } + + /* They look valid */ + + if (mddev->raid_disks == 2) { + /* can make the change immediately */ + if (mddev->new_layout >= 0) { + conf->algorithm = mddev->new_layout; + mddev->layout = mddev->new_layout; + } + if (new_chunk > 0) { + conf->chunk_sectors = new_chunk ; + mddev->chunk_sectors = new_chunk; + } + set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); + md_wakeup_thread(mddev->thread); + } + return check_reshape(mddev); +} + +static int raid6_check_reshape(struct mddev *mddev) +{ + int new_chunk = mddev->new_chunk_sectors; + + if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout)) + return -EINVAL; + if (new_chunk > 0) { + if (!is_power_of_2(new_chunk)) + return -EINVAL; + if (new_chunk < (PAGE_SIZE >> 9)) + return -EINVAL; + if (mddev->array_sectors & (new_chunk-1)) + /* not factor of array size */ + return -EINVAL; + } + + /* They look valid */ + return check_reshape(mddev); +} + +static void *raid5_takeover(struct mddev *mddev) +{ + /* raid5 can take over: + * raid0 - if there is only one strip zone - make it a raid4 layout + * raid1 - if there are two drives. We need to know the chunk size + * raid4 - trivial - just use a raid4 layout. + * raid6 - Providing it is a *_6 layout + */ + if (mddev->level == 0) + return raid45_takeover_raid0(mddev, 5); + if (mddev->level == 1) + return raid5_takeover_raid1(mddev); + if (mddev->level == 4) { + mddev->new_layout = ALGORITHM_PARITY_N; + mddev->new_level = 5; + return setup_conf(mddev); + } + if (mddev->level == 6) + return raid5_takeover_raid6(mddev); + + return ERR_PTR(-EINVAL); +} + +static void *raid4_takeover(struct mddev *mddev) +{ + /* raid4 can take over: + * raid0 - if there is only one strip zone + * raid5 - if layout is right + */ + if (mddev->level == 0) + return raid45_takeover_raid0(mddev, 4); + if (mddev->level == 5 && + mddev->layout == ALGORITHM_PARITY_N) { + mddev->new_layout = 0; + mddev->new_level = 4; + return setup_conf(mddev); + } + return ERR_PTR(-EINVAL); +} + +static struct md_personality raid5_personality; + +static void *raid6_takeover(struct mddev *mddev) +{ + /* Currently can only take over a raid5. We map the + * personality to an equivalent raid6 personality + * with the Q block at the end. + */ + int new_layout; + + if (mddev->pers != &raid5_personality) + return ERR_PTR(-EINVAL); + if (mddev->degraded > 1) + return ERR_PTR(-EINVAL); + if (mddev->raid_disks > 253) + return ERR_PTR(-EINVAL); + if (mddev->raid_disks < 3) + return ERR_PTR(-EINVAL); + + switch (mddev->layout) { + case ALGORITHM_LEFT_ASYMMETRIC: + new_layout = ALGORITHM_LEFT_ASYMMETRIC_6; + break; + case ALGORITHM_RIGHT_ASYMMETRIC: + new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6; + break; + case ALGORITHM_LEFT_SYMMETRIC: + new_layout = ALGORITHM_LEFT_SYMMETRIC_6; + break; + case ALGORITHM_RIGHT_SYMMETRIC: + new_layout = ALGORITHM_RIGHT_SYMMETRIC_6; + break; + case ALGORITHM_PARITY_0: + new_layout = ALGORITHM_PARITY_0_6; + break; + case ALGORITHM_PARITY_N: + new_layout = ALGORITHM_PARITY_N; + break; + default: + return ERR_PTR(-EINVAL); + } + mddev->new_level = 6; + mddev->new_layout = new_layout; + mddev->delta_disks = 1; + mddev->raid_disks += 1; + return setup_conf(mddev); +} + +static int raid5_change_consistency_policy(struct mddev *mddev, const char *buf) +{ + struct r5conf *conf; + int err; + + err = mddev_lock(mddev); + if (err) + return err; + conf = mddev->private; + if (!conf) { + mddev_unlock(mddev); + return -ENODEV; + } + + if (strncmp(buf, "ppl", 3) == 0) { + /* ppl only works with RAID 5 */ + if (!raid5_has_ppl(conf) && conf->level == 5) { + err = log_init(conf, NULL, true); + if (!err) { + err = resize_stripes(conf, conf->pool_size); + if (err) + log_exit(conf); + } + } else + err = -EINVAL; + } else if (strncmp(buf, "resync", 6) == 0) { + if (raid5_has_ppl(conf)) { + mddev_suspend(mddev); + log_exit(conf); + mddev_resume(mddev); + err = resize_stripes(conf, conf->pool_size); + } else if (test_bit(MD_HAS_JOURNAL, &conf->mddev->flags) && + r5l_log_disk_error(conf)) { + bool journal_dev_exists = false; + struct md_rdev *rdev; + + rdev_for_each(rdev, mddev) + if (test_bit(Journal, &rdev->flags)) { + journal_dev_exists = true; + break; + } + + if (!journal_dev_exists) { + mddev_suspend(mddev); + clear_bit(MD_HAS_JOURNAL, &mddev->flags); + mddev_resume(mddev); + } else /* need remove journal device first */ + err = -EBUSY; + } else + err = -EINVAL; + } else { + err = -EINVAL; + } + + if (!err) + md_update_sb(mddev, 1); + + mddev_unlock(mddev); + + return err; +} + +static int raid5_start(struct mddev *mddev) +{ + struct r5conf *conf = mddev->private; + + return r5l_start(conf->log); +} + +static struct md_personality raid6_personality = +{ + .name = "raid6", + .level = 6, + .owner = THIS_MODULE, + .make_request = raid5_make_request, + .run = raid5_run, + .start = raid5_start, + .free = raid5_free, + .status = raid5_status, + .error_handler = raid5_error, + .hot_add_disk = raid5_add_disk, + .hot_remove_disk= raid5_remove_disk, + .spare_active = raid5_spare_active, + .sync_request = raid5_sync_request, + .resize = raid5_resize, + .size = raid5_size, + .check_reshape = raid6_check_reshape, + .start_reshape = raid5_start_reshape, + .finish_reshape = raid5_finish_reshape, + .quiesce = raid5_quiesce, + .takeover = raid6_takeover, + .congested = raid5_congested, + .change_consistency_policy = raid5_change_consistency_policy, +}; +static struct md_personality raid5_personality = +{ + .name = "raid5", + .level = 5, + .owner = THIS_MODULE, + .make_request = raid5_make_request, + .run = raid5_run, + .start = raid5_start, + .free = raid5_free, + .status = raid5_status, + .error_handler = raid5_error, + .hot_add_disk = raid5_add_disk, + .hot_remove_disk= raid5_remove_disk, + .spare_active = raid5_spare_active, + .sync_request = raid5_sync_request, + .resize = raid5_resize, + .size = raid5_size, + .check_reshape = raid5_check_reshape, + .start_reshape = raid5_start_reshape, + .finish_reshape = raid5_finish_reshape, + .quiesce = raid5_quiesce, + .takeover = raid5_takeover, + .congested = raid5_congested, + .change_consistency_policy = raid5_change_consistency_policy, +}; + +static struct md_personality raid4_personality = +{ + .name = "raid4", + .level = 4, + .owner = THIS_MODULE, + .make_request = raid5_make_request, + .run = raid5_run, + .start = raid5_start, + .free = raid5_free, + .status = raid5_status, + .error_handler = raid5_error, + .hot_add_disk = raid5_add_disk, + .hot_remove_disk= raid5_remove_disk, + .spare_active = raid5_spare_active, + .sync_request = raid5_sync_request, + .resize = raid5_resize, + .size = raid5_size, + .check_reshape = raid5_check_reshape, + .start_reshape = raid5_start_reshape, + .finish_reshape = raid5_finish_reshape, + .quiesce = raid5_quiesce, + .takeover = raid4_takeover, + .congested = raid5_congested, + .change_consistency_policy = raid5_change_consistency_policy, +}; + +static int __init raid5_init(void) +{ + int ret; + + raid5_wq = alloc_workqueue("raid5wq", + WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE|WQ_SYSFS, 0); + if (!raid5_wq) + return -ENOMEM; + + ret = cpuhp_setup_state_multi(CPUHP_MD_RAID5_PREPARE, + "md/raid5:prepare", + raid456_cpu_up_prepare, + raid456_cpu_dead); + if (ret) { + destroy_workqueue(raid5_wq); + return ret; + } + 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); + cpuhp_remove_multi_state(CPUHP_MD_RAID5_PREPARE); + destroy_workqueue(raid5_wq); +} + +module_init(raid5_init); +module_exit(raid5_exit); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD"); +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"); |