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-rw-r--r--drivers/md/raid5.c9177
1 files changed, 9177 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
new file mode 100644
index 000000000..e4564ca1f
--- /dev/null
+++ b/drivers/md/raid5.c
@@ -0,0 +1,9177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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!
+ */
+
+/*
+ * 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/delay.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 <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
+
+#define RAID5_MAX_REQ_STRIPES 256
+
+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 >> RAID5_STRIPE_SHIFT(conf)) & HASH_MASK;
+ return &conf->stripe_hashtbl[hash];
+}
+
+static inline int stripe_hash_locks_hash(struct r5conf *conf, sector_t sect)
+{
+ return (sect >> RAID5_STRIPE_SHIFT(conf)) & STRIPE_HASH_LOCKS_MASK;
+}
+
+static inline void lock_device_hash_lock(struct r5conf *conf, int hash)
+ __acquires(&conf->device_lock)
+{
+ spin_lock_irq(conf->hash_locks + hash);
+ spin_lock(&conf->device_lock);
+}
+
+static inline void unlock_device_hash_lock(struct r5conf *conf, int hash)
+ __releases(&conf->device_lock)
+{
+ spin_unlock(&conf->device_lock);
+ spin_unlock_irq(conf->hash_locks + hash);
+}
+
+static inline void lock_all_device_hash_locks_irq(struct r5conf *conf)
+ __acquires(&conf->device_lock)
+{
+ 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)
+ __releases(&conf->device_lock)
+{
+ 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)
+ __must_hold(&sh->raid_conf->device_lock)
+{
+ 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)
+ __must_hold(&conf->device_lock)
+{
+ 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)
+ __must_hold(&conf->device_lock)
+{
+ 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);
+ }
+}
+
+static int release_stripe_list(struct r5conf *conf,
+ struct list_head *temp_inactive_list)
+ __must_hold(&conf->device_lock)
+{
+ 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;
+}
+
+#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
+static void free_stripe_pages(struct stripe_head *sh)
+{
+ int i;
+ struct page *p;
+
+ /* Have not allocate page pool */
+ if (!sh->pages)
+ return;
+
+ for (i = 0; i < sh->nr_pages; i++) {
+ p = sh->pages[i];
+ if (p)
+ put_page(p);
+ sh->pages[i] = NULL;
+ }
+}
+
+static int alloc_stripe_pages(struct stripe_head *sh, gfp_t gfp)
+{
+ int i;
+ struct page *p;
+
+ for (i = 0; i < sh->nr_pages; i++) {
+ /* The page have allocated. */
+ if (sh->pages[i])
+ continue;
+
+ p = alloc_page(gfp);
+ if (!p) {
+ free_stripe_pages(sh);
+ return -ENOMEM;
+ }
+ sh->pages[i] = p;
+ }
+ return 0;
+}
+
+static int
+init_stripe_shared_pages(struct stripe_head *sh, struct r5conf *conf, int disks)
+{
+ int nr_pages, cnt;
+
+ if (sh->pages)
+ return 0;
+
+ /* Each of the sh->dev[i] need one conf->stripe_size */
+ cnt = PAGE_SIZE / conf->stripe_size;
+ nr_pages = (disks + cnt - 1) / cnt;
+
+ sh->pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
+ if (!sh->pages)
+ return -ENOMEM;
+ sh->nr_pages = nr_pages;
+ sh->stripes_per_page = cnt;
+ return 0;
+}
+#endif
+
+static void shrink_buffers(struct stripe_head *sh)
+{
+ int i;
+ int num = sh->raid_conf->pool_size;
+
+#if PAGE_SIZE == DEFAULT_STRIPE_SIZE
+ for (i = 0; i < num ; i++) {
+ struct page *p;
+
+ 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);
+ }
+#else
+ for (i = 0; i < num; i++)
+ sh->dev[i].page = NULL;
+ free_stripe_pages(sh); /* Free pages */
+#endif
+}
+
+static int grow_buffers(struct stripe_head *sh, gfp_t gfp)
+{
+ int i;
+ int num = sh->raid_conf->pool_size;
+
+#if PAGE_SIZE == DEFAULT_STRIPE_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;
+ sh->dev[i].offset = 0;
+ }
+#else
+ if (alloc_stripe_pages(sh, gfp))
+ return -ENOMEM;
+
+ for (i = 0; i < num; i++) {
+ sh->dev[i].page = raid5_get_dev_page(sh, i);
+ sh->dev[i].orig_page = sh->dev[i].page;
+ sh->dev[i].offset = raid5_get_page_offset(sh, i);
+ }
+#endif
+ 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;
+}
+
+static struct stripe_head *find_get_stripe(struct r5conf *conf,
+ sector_t sector, short generation, int hash)
+{
+ int inc_empty_inactive_list_flag;
+ struct stripe_head *sh;
+
+ sh = __find_stripe(conf, sector, generation);
+ if (!sh)
+ return NULL;
+
+ if (atomic_inc_not_zero(&sh->count))
+ return sh;
+
+ /*
+ * Slow path. The reference count is zero which means the stripe must
+ * be on a list (sh->lru). Must remove the stripe from the list that
+ * references it with the device_lock held.
+ */
+
+ 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);
+
+ return sh;
+}
+
+/*
+ * 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.
+ *
+ * Most calls to this function hold &conf->device_lock. Calls
+ * in raid5_run() do not require the lock as no other threads
+ * have been started yet.
+ */
+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 bool has_failed(struct r5conf *conf)
+{
+ int degraded = conf->mddev->degraded;
+
+ if (test_bit(MD_BROKEN, &conf->mddev->flags))
+ return true;
+
+ if (conf->mddev->reshape_position != MaxSector)
+ degraded = raid5_calc_degraded(conf);
+
+ return degraded > conf->max_degraded;
+}
+
+enum stripe_result {
+ STRIPE_SUCCESS = 0,
+ STRIPE_RETRY,
+ STRIPE_SCHEDULE_AND_RETRY,
+ STRIPE_FAIL,
+};
+
+struct stripe_request_ctx {
+ /* a reference to the last stripe_head for batching */
+ struct stripe_head *batch_last;
+
+ /* first sector in the request */
+ sector_t first_sector;
+
+ /* last sector in the request */
+ sector_t last_sector;
+
+ /*
+ * bitmap to track stripe sectors that have been added to stripes
+ * add one to account for unaligned requests
+ */
+ DECLARE_BITMAP(sectors_to_do, RAID5_MAX_REQ_STRIPES + 1);
+
+ /* the request had REQ_PREFLUSH, cleared after the first stripe_head */
+ bool do_flush;
+};
+
+/*
+ * Block until another thread clears R5_INACTIVE_BLOCKED or
+ * there are fewer than 3/4 the maximum number of active stripes
+ * and there is an inactive stripe available.
+ */
+static bool is_inactive_blocked(struct r5conf *conf, int hash)
+{
+ if (list_empty(conf->inactive_list + hash))
+ return false;
+
+ if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
+ return true;
+
+ return (atomic_read(&conf->active_stripes) <
+ (conf->max_nr_stripes * 3 / 4));
+}
+
+struct stripe_head *raid5_get_active_stripe(struct r5conf *conf,
+ struct stripe_request_ctx *ctx, sector_t sector,
+ unsigned int flags)
+{
+ struct stripe_head *sh;
+ int hash = stripe_hash_locks_hash(conf, sector);
+ int previous = !!(flags & R5_GAS_PREVIOUS);
+
+ pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
+
+ spin_lock_irq(conf->hash_locks + hash);
+
+ for (;;) {
+ if (!(flags & R5_GAS_NOQUIESCE) && conf->quiesce) {
+ /*
+ * Must release the reference to batch_last before
+ * waiting, on quiesce, otherwise the batch_last will
+ * hold a reference to a stripe and raid5_quiesce()
+ * will deadlock waiting for active_stripes to go to
+ * zero.
+ */
+ if (ctx && ctx->batch_last) {
+ raid5_release_stripe(ctx->batch_last);
+ ctx->batch_last = NULL;
+ }
+
+ wait_event_lock_irq(conf->wait_for_quiescent,
+ !conf->quiesce,
+ *(conf->hash_locks + hash));
+ }
+
+ sh = find_get_stripe(conf, sector, conf->generation - previous,
+ hash);
+ if (sh)
+ break;
+
+ if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) {
+ sh = get_free_stripe(conf, hash);
+ if (sh) {
+ r5c_check_stripe_cache_usage(conf);
+ init_stripe(sh, sector, previous);
+ atomic_inc(&sh->count);
+ break;
+ }
+
+ if (!test_bit(R5_DID_ALLOC, &conf->cache_state))
+ set_bit(R5_ALLOC_MORE, &conf->cache_state);
+ }
+
+ if (flags & R5_GAS_NOBLOCK)
+ break;
+
+ set_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
+ r5l_wake_reclaim(conf->log, 0);
+
+ /* release batch_last before wait to avoid risk of deadlock */
+ if (ctx && ctx->batch_last) {
+ raid5_release_stripe(ctx->batch_last);
+ ctx->batch_last = NULL;
+ }
+
+ wait_event_lock_irq(conf->wait_for_stripe,
+ is_inactive_blocked(conf, hash),
+ *(conf->hash_locks + hash));
+ clear_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
+ }
+
+ 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)
+ __acquires(&sh1->stripe_lock)
+ __acquires(&sh2->stripe_lock)
+{
+ 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)
+ __releases(&sh1->stripe_lock)
+ __releases(&sh2->stripe_lock)
+{
+ 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 *last_sh)
+{
+ struct stripe_head *head;
+ sector_t head_sector, tmp_sec;
+ int hash;
+ int dd_idx;
+
+ /* 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 - RAID5_STRIPE_SECTORS(conf);
+
+ if (last_sh && head_sector == last_sh->sector) {
+ head = last_sh;
+ atomic_inc(&head->count);
+ } else {
+ hash = stripe_hash_locks_hash(conf, head_sector);
+ spin_lock_irq(conf->hash_locks + hash);
+ head = find_get_stripe(conf, head_sector, conf->generation,
+ hash);
+ 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)))
+ submit_bio_noacct(bio);
+}
+
+static int cmp_stripe(void *priv, const struct list_head *a,
+ const 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;
+ struct r5dev *dev;
+ 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--; ) {
+ enum req_op op;
+ blk_opf_t 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:
+ dev = &sh->dev[i];
+ bi = &dev->req;
+ rbi = &dev->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, RAID5_STRIPE_SECTORS(conf),
+ &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, RAID5_STRIPE_SECTORS(conf));
+
+ set_bit(STRIPE_IO_STARTED, &sh->state);
+
+ bio_init(bi, rdev->bdev, &dev->vec, 1, 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 = RAID5_STRIPE_SIZE(conf);
+ bi->bi_io_vec[0].bv_offset = sh->dev[i].offset;
+ bi->bi_iter.bi_size = RAID5_STRIPE_SIZE(conf);
+ /*
+ * 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,
+ disk_devt(conf->mddev->gendisk),
+ sh->dev[i].sector);
+ if (should_defer && op_is_write(op))
+ bio_list_add(&pending_bios, bi);
+ else
+ submit_bio_noacct(bi);
+ }
+ if (rrdev) {
+ if (s->syncing || s->expanding || s->expanded
+ || s->replacing)
+ md_sync_acct(rrdev->bdev, RAID5_STRIPE_SECTORS(conf));
+
+ set_bit(STRIPE_IO_STARTED, &sh->state);
+
+ bio_init(rbi, rrdev->bdev, &dev->rvec, 1, 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 = RAID5_STRIPE_SIZE(conf);
+ rbi->bi_io_vec[0].bv_offset = sh->dev[i].offset;
+ rbi->bi_iter.bi_size = RAID5_STRIPE_SIZE(conf);
+ /*
+ * 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,
+ disk_devt(conf->mddev->gendisk),
+ sh->dev[i].sector);
+ if (should_defer && op_is_write(op))
+ bio_list_add(&pending_bios, rbi);
+ else
+ submit_bio_noacct(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,
+ unsigned int poff, 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;
+ struct r5conf *conf = sh->raid_conf;
+
+ 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 > RAID5_STRIPE_SIZE(conf))
+ clen = RAID5_STRIPE_SIZE(conf) - page_offset;
+ else
+ clen = len;
+
+ if (clen > 0) {
+ b_offset += bvl.bv_offset;
+ bio_page = bvl.bv_page;
+ if (frombio) {
+ if (conf->skip_copy &&
+ b_offset == 0 && page_offset == 0 &&
+ clen == RAID5_STRIPE_SIZE(conf) &&
+ !no_skipcopy)
+ *page = bio_page;
+ else
+ tx = async_memcpy(*page, bio_page, page_offset + poff,
+ b_offset, clen, &submit);
+ } else
+ tx = async_memcpy(bio_page, *page, b_offset,
+ page_offset + poff, 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;
+ struct r5conf *conf = sh->raid_conf;
+
+ 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 + RAID5_STRIPE_SECTORS(conf)) {
+ rbi2 = r5_next_bio(conf, 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;
+ struct r5conf *conf = sh->raid_conf;
+
+ 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 + RAID5_STRIPE_SECTORS(conf)) {
+ tx = async_copy_data(0, rbi, &dev->page,
+ dev->offset,
+ dev->sector, tx, sh, 0);
+ rbi = r5_next_bio(conf, 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 struct page **to_addr_page(struct raid5_percpu *percpu, int i)
+{
+ return percpu->scribble + i * percpu->scribble_obj_size;
+}
+
+/* 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)
+{
+ return (void *) (to_addr_page(percpu, i) + sh->disks + 2);
+}
+
+/*
+ * Return a pointer to record offset address.
+ */
+static unsigned int *
+to_addr_offs(struct stripe_head *sh, struct raid5_percpu *percpu)
+{
+ return (unsigned int *) (to_addr_conv(sh, percpu, 0) + sh->disks + 2);
+}
+
+static struct dma_async_tx_descriptor *
+ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
+{
+ int disks = sh->disks;
+ struct page **xor_srcs = to_addr_page(percpu, 0);
+ unsigned int *off_srcs = to_addr_offs(sh, percpu);
+ int target = sh->ops.target;
+ struct r5dev *tgt = &sh->dev[target];
+ struct page *xor_dest = tgt->page;
+ unsigned int off_dest = tgt->offset;
+ 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) {
+ off_srcs[count] = sh->dev[i].offset;
+ 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], off_dest, off_srcs[0],
+ RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
+ else
+ tx = async_xor_offs(xor_dest, off_dest, xor_srcs, off_srcs, count,
+ RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
+
+ return tx;
+}
+
+/* set_syndrome_sources - populate source buffers for gen_syndrome
+ * @srcs - (struct page *) array of size sh->disks
+ * @offs - (unsigned int) array of offset for each page
+ * @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,
+ unsigned int *offs,
+ 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;
+ /*
+ * For R5_InJournal, PAGE_SIZE must be 4KB and will
+ * not shared page. In that case, dev[i].offset
+ * is 0.
+ */
+ offs[slot] = sh->dev[i].offset;
+ }
+ 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);
+ unsigned int *offs = to_addr_offs(sh, percpu);
+ 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;
+ unsigned int dest_off;
+ 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;
+ dest_off = tgt->offset;
+
+ atomic_inc(&sh->count);
+
+ if (target == qd_idx) {
+ count = set_syndrome_sources(blocks, offs, 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, offs, count+2,
+ RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
+ } else {
+ /* Compute any data- or p-drive using XOR */
+ count = 0;
+ for (i = disks; i-- ; ) {
+ if (i == target || i == qd_idx)
+ continue;
+ offs[count] = sh->dev[i].offset;
+ 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_offs(dest, dest_off, blocks, offs, count,
+ RAID5_STRIPE_SIZE(sh->raid_conf), &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);
+ unsigned int *offs = to_addr_offs(sh, percpu);
+ 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++) {
+ offs[i] = 0;
+ blocks[i] = NULL;
+ }
+ count = 0;
+ i = d0_idx;
+ do {
+ int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
+
+ offs[slot] = sh->dev[i].offset;
+ 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, offs, syndrome_disks+2,
+ RAID5_STRIPE_SIZE(sh->raid_conf),
+ &submit);
+ } else {
+ struct page *dest;
+ unsigned int dest_off;
+ 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;
+ offs[count] = sh->dev[i].offset;
+ blocks[count++] = sh->dev[i].page;
+ }
+ dest = sh->dev[data_target].page;
+ dest_off = sh->dev[data_target].offset;
+ init_async_submit(&submit,
+ ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
+ NULL, NULL, NULL,
+ to_addr_conv(sh, percpu, 0));
+ tx = async_xor_offs(dest, dest_off, blocks, offs, count,
+ RAID5_STRIPE_SIZE(sh->raid_conf),
+ &submit);
+
+ count = set_syndrome_sources(blocks, offs, 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, offs, count+2,
+ RAID5_STRIPE_SIZE(sh->raid_conf),
+ &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,
+ RAID5_STRIPE_SIZE(sh->raid_conf),
+ faila,
+ blocks, offs, &submit);
+ } else {
+ /* We're missing D+D. */
+ return async_raid6_2data_recov(syndrome_disks+2,
+ RAID5_STRIPE_SIZE(sh->raid_conf),
+ faila, failb,
+ blocks, offs, &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);
+ unsigned int *off_srcs = to_addr_offs(sh, percpu);
+ int count = 0, pd_idx = sh->pd_idx, i;
+ struct async_submit_ctl submit;
+
+ /* existing parity data subtracted */
+ unsigned int off_dest = off_srcs[count] = sh->dev[pd_idx].offset;
+ 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)) {
+ /*
+ * For this case, PAGE_SIZE must be equal to 4KB and
+ * page offset is zero.
+ */
+ off_srcs[count] = dev->offset;
+ xor_srcs[count++] = dev->orig_page;
+ } else if (test_bit(R5_Wantdrain, &dev->flags)) {
+ off_srcs[count] = dev->offset;
+ 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_offs(xor_dest, off_dest, xor_srcs, off_srcs, count,
+ RAID5_STRIPE_SIZE(sh->raid_conf), &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);
+ unsigned int *offs = to_addr_offs(sh, percpu);
+ int count;
+ struct async_submit_ctl submit;
+
+ pr_debug("%s: stripe %llu\n", __func__,
+ (unsigned long long)sh->sector);
+
+ count = set_syndrome_sources(blocks, offs, 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, offs, count+2,
+ RAID5_STRIPE_SIZE(sh->raid_conf), &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 + RAID5_STRIPE_SECTORS(conf)) {
+ 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->offset,
+ 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(conf, 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;
+ unsigned int *off_srcs;
+ struct async_submit_ctl submit;
+ int count, pd_idx = sh->pd_idx, i;
+ struct page *xor_dest;
+ unsigned int off_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);
+ off_srcs = to_addr_offs(sh, percpu);
+ /* 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;
+ off_dest = off_srcs[count] = sh->dev[pd_idx].offset;
+ 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)) {
+ off_srcs[count] = dev->offset;
+ xor_srcs[count++] = dev->page;
+ }
+ }
+ } else {
+ xor_dest = sh->dev[pd_idx].page;
+ off_dest = sh->dev[pd_idx].offset;
+ for (i = disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ if (i != pd_idx) {
+ off_srcs[count] = dev->offset;
+ 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], off_dest, off_srcs[0],
+ RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
+ else
+ tx = async_xor_offs(xor_dest, off_dest, xor_srcs, off_srcs, count,
+ RAID5_STRIPE_SIZE(sh->raid_conf), &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;
+ unsigned int *offs;
+ 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);
+ offs = to_addr_offs(sh, percpu);
+
+ 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, offs, 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, offs, count+2,
+ RAID5_STRIPE_SIZE(sh->raid_conf), &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;
+ unsigned int off_dest;
+ struct page **xor_srcs = to_addr_page(percpu, 0);
+ unsigned int *off_srcs = to_addr_offs(sh, percpu);
+ 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;
+ off_dest = sh->dev[pd_idx].offset;
+ off_srcs[count] = off_dest;
+ xor_srcs[count++] = xor_dest;
+ for (i = disks; i--; ) {
+ if (i == pd_idx || i == qd_idx)
+ continue;
+ off_srcs[count] = sh->dev[i].offset;
+ 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_offs(xor_dest, off_dest, xor_srcs, off_srcs, count,
+ RAID5_STRIPE_SIZE(sh->raid_conf),
+ &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);
+ unsigned int *offs = to_addr_offs(sh, percpu);
+ 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, offs, 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, offs, count+2,
+ RAID5_STRIPE_SIZE(sh->raid_conf),
+ &sh->ops.zero_sum_result, percpu->spare_page, 0, &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;
+
+ local_lock(&conf->percpu->lock);
+ percpu = this_cpu_ptr(conf->percpu);
+ 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);
+ }
+ }
+ local_unlock(&conf->percpu->lock);
+}
+
+static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh)
+{
+#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
+ kfree(sh->pages);
+#endif
+ 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;
+
+ 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;
+
+ if (raid5_has_ppl(conf)) {
+ sh->ppl_page = alloc_page(gfp);
+ if (!sh->ppl_page) {
+ free_stripe(sc, sh);
+ return NULL;
+ }
+ }
+#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
+ if (init_stripe_shared_pages(sh, conf, disks)) {
+ free_stripe(sc, sh);
+ return NULL;
+ }
+#endif
+ }
+ 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_alloc - allocate percpu scribble buffer for required size
+ * of the scribble region
+ * @percpu: from for_each_present_cpu() of the caller
+ * @num: total number of disks in the array
+ * @cnt: scribble objs count for required size of the scribble region
+ *
+ * The scribble buffer 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 int scribble_alloc(struct raid5_percpu *percpu,
+ int num, int cnt)
+{
+ size_t obj_size =
+ sizeof(struct page *) * (num + 2) +
+ sizeof(addr_conv_t) * (num + 2) +
+ sizeof(unsigned int) * (num + 2);
+ void *scribble;
+
+ /*
+ * If here is in raid array suspend context, it is in memalloc noio
+ * context as well, there is no potential recursive memory reclaim
+ * I/Os with the GFP_KERNEL flag.
+ */
+ scribble = kvmalloc_array(cnt, obj_size, GFP_KERNEL);
+ if (!scribble)
+ return -ENOMEM;
+
+ kvfree(percpu->scribble);
+
+ percpu->scribble = scribble;
+ percpu->scribble_obj_size = obj_size;
+ return 0;
+}
+
+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);
+ cpus_read_lock();
+
+ for_each_present_cpu(cpu) {
+ struct raid5_percpu *percpu;
+
+ percpu = per_cpu_ptr(conf->percpu, cpu);
+ err = scribble_alloc(percpu, new_disks,
+ new_sectors / RAID5_STRIPE_SECTORS(conf));
+ if (err)
+ break;
+ }
+
+ cpus_read_unlock();
+ 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);
+
+#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
+ for (i = 0; i < osh->nr_pages; i++) {
+ nsh->pages[i] = osh->pages[i];
+ osh->pages[i] = NULL;
+ }
+#endif
+ 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->dev[i].offset = osh->dev[i].offset;
+ }
+ 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);
+
+#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
+ for (i = 0; i < nsh->nr_pages; i++) {
+ if (nsh->pages[i])
+ continue;
+ nsh->pages[i] = alloc_page(GFP_NOIO);
+ if (!nsh->pages[i])
+ err = -ENOMEM;
+ }
+
+ for (i = conf->raid_disks; i < newsize; i++) {
+ if (nsh->dev[i].page)
+ continue;
+ nsh->dev[i].page = raid5_get_dev_page(nsh, i);
+ nsh->dev[i].orig_page = nsh->dev[i].page;
+ nsh->dev[i].offset = raid5_get_page_offset(nsh, i);
+ }
+#else
+ 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;
+ nsh->dev[i].offset = 0;
+ if (!p)
+ err = -ENOMEM;
+ }
+#endif
+ 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;
+}
+
+/*
+ * This helper wraps rcu_dereference_protected() and can be used when
+ * it is known that the nr_pending of the rdev is elevated.
+ */
+static struct md_rdev *rdev_pend_deref(struct md_rdev __rcu *rdev)
+{
+ return rcu_dereference_protected(rdev,
+ atomic_read(&rcu_access_pointer(rdev)->nr_pending));
+}
+
+/*
+ * This helper wraps rcu_dereference_protected() and should be used
+ * when it is known that the mddev_lock() is held. This is safe
+ * seeing raid5_remove_disk() has the same lock held.
+ */
+static struct md_rdev *rdev_mdlock_deref(struct mddev *mddev,
+ struct md_rdev __rcu *rdev)
+{
+ return rcu_dereference_protected(rdev,
+ lockdep_is_held(&mddev->reconfig_mutex));
+}
+
+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;
+ 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) {
+ 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 = rdev_pend_deref(conf->disks[i].replacement);
+ if (!rdev)
+ rdev = rdev_pend_deref(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 %pg)\n",
+ mdname(conf->mddev), RAID5_STRIPE_SECTORS(conf),
+ (unsigned long long)s,
+ rdev->bdev);
+ atomic_add(RAID5_STRIPE_SECTORS(conf), &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 {
+ 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 %pg).\n",
+ mdname(conf->mddev),
+ (unsigned long long)s,
+ rdev->bdev);
+ else if (conf->mddev->degraded >= conf->max_degraded) {
+ set_bad = 1;
+ pr_warn_ratelimited(
+ "md/raid:%s: read error not correctable (sector %llu on %pg).\n",
+ mdname(conf->mddev),
+ (unsigned long long)s,
+ rdev->bdev);
+ } 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 %pg).\n",
+ mdname(conf->mddev),
+ (unsigned long long)s,
+ rdev->bdev);
+ } else if (atomic_read(&rdev->read_errors)
+ > conf->max_nr_stripes) {
+ if (!test_bit(Faulty, &rdev->flags)) {
+ pr_warn("md/raid:%s: %d read_errors > %d stripes\n",
+ mdname(conf->mddev),
+ atomic_read(&rdev->read_errors),
+ conf->max_nr_stripes);
+ pr_warn("md/raid:%s: Too many read errors, failing device %pg.\n",
+ mdname(conf->mddev), rdev->bdev);
+ }
+ } 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, RAID5_STRIPE_SECTORS(conf), 0)))
+ md_error(conf->mddev, rdev);
+ }
+ }
+ rdev_dec_pending(rdev, conf->mddev);
+ bio_uninit(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 *rdev;
+ sector_t first_bad;
+ int bad_sectors;
+ int replacement = 0;
+
+ for (i = 0 ; i < disks; i++) {
+ if (bi == &sh->dev[i].req) {
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
+ break;
+ }
+ if (bi == &sh->dev[i].rreq) {
+ rdev = rdev_pend_deref(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 = rdev_pend_deref(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) {
+ BUG();
+ return;
+ }
+
+ if (replacement) {
+ if (bi->bi_status)
+ md_error(conf->mddev, rdev);
+ else if (is_badblock(rdev, sh->sector,
+ RAID5_STRIPE_SECTORS(conf),
+ &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,
+ RAID5_STRIPE_SECTORS(conf),
+ &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_uninit(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);
+
+ if (sh->batch_head && sh != sh->batch_head)
+ raid5_release_stripe(sh->batch_head);
+ raid5_release_stripe(sh);
+}
+
+static void raid5_error(struct mddev *mddev, struct md_rdev *rdev)
+{
+ struct r5conf *conf = mddev->private;
+ unsigned long flags;
+ pr_debug("raid456: error called\n");
+
+ pr_crit("md/raid:%s: Disk failure on %pg, disabling device.\n",
+ mdname(mddev), rdev->bdev);
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ set_bit(Faulty, &rdev->flags);
+ clear_bit(In_sync, &rdev->flags);
+ mddev->degraded = raid5_calc_degraded(conf);
+
+ if (has_failed(conf)) {
+ set_bit(MD_BROKEN, &conf->mddev->flags);
+ conf->recovery_disabled = mddev->recovery_disabled;
+
+ pr_crit("md/raid:%s: Cannot continue operation (%d/%d failed).\n",
+ mdname(mddev), mddev->degraded, conf->raid_disks);
+ } else {
+ pr_crit("md/raid:%s: Operation continuing on %d devices.\n",
+ mdname(mddev), conf->raid_disks - mddev->degraded);
+ }
+
+ 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));
+ 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);
+}
+
+static bool stripe_bio_overlaps(struct stripe_head *sh, struct bio *bi,
+ int dd_idx, int forwrite)
+{
+ struct r5conf *conf = sh->raid_conf;
+ struct bio **bip;
+
+ pr_debug("checking bi b#%llu to stripe s#%llu\n",
+ bi->bi_iter.bi_sector, sh->sector);
+
+ /* Don't allow new IO added to stripes in batch list */
+ if (sh->batch_head)
+ return true;
+
+ if (forwrite)
+ bip = &sh->dev[dd_idx].towrite;
+ 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)
+ return true;
+ bip = &(*bip)->bi_next;
+ }
+
+ if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi))
+ return true;
+
+ 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)
+ return true;
+ }
+
+ return false;
+}
+
+static void __add_stripe_bio(struct stripe_head *sh, struct bio *bi,
+ int dd_idx, int forwrite, int previous)
+{
+ struct r5conf *conf = sh->raid_conf;
+ struct bio **bip;
+ int firstwrite = 0;
+
+ if (forwrite) {
+ bip = &sh->dev[dd_idx].towrite;
+ if (!*bip)
+ firstwrite = 1;
+ } else {
+ bip = &sh->dev[dd_idx].toread;
+ }
+
+ while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector)
+ bip = &(*bip)->bi_next;
+
+ 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 + RAID5_STRIPE_SECTORS(conf) &&
+ bi && bi->bi_iter.bi_sector <= sector;
+ bi = r5_next_bio(conf, bi, sh->dev[dd_idx].sector)) {
+ if (bio_end_sector(bi) >= sector)
+ sector = bio_end_sector(bi);
+ }
+ if (sector >= sh->dev[dd_idx].sector + RAID5_STRIPE_SECTORS(conf))
+ 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, logical %llu\n",
+ (*bip)->bi_iter.bi_sector, sh->sector, dd_idx,
+ sh->dev[dd_idx].sector);
+
+ 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,
+ RAID5_STRIPE_SECTORS(conf), 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);
+ }
+ }
+}
+
+/*
+ * Each stripe/dev can have one or more bios attached.
+ * toread/towrite point to the first in a chain.
+ * The bi_next chain must be in order.
+ */
+static bool add_stripe_bio(struct stripe_head *sh, struct bio *bi,
+ int dd_idx, int forwrite, int previous)
+{
+ spin_lock_irq(&sh->stripe_lock);
+
+ if (stripe_bio_overlaps(sh, bi, dd_idx, forwrite)) {
+ set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
+ spin_unlock_irq(&sh->stripe_lock);
+ return false;
+ }
+
+ __add_stripe_bio(sh, bi, dd_idx, forwrite, previous);
+ spin_unlock_irq(&sh->stripe_lock);
+ return true;
+}
+
+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,
+ RAID5_STRIPE_SECTORS(conf), 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 + RAID5_STRIPE_SECTORS(conf)) {
+ struct bio *nextbi = r5_next_bio(conf, 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,
+ RAID5_STRIPE_SECTORS(conf), 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 + RAID5_STRIPE_SECTORS(conf)) {
+ struct bio *bi2 = r5_next_bio(conf, 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 + RAID5_STRIPE_SECTORS(conf)) {
+ struct bio *nextbi =
+ r5_next_bio(conf, bi, sh->dev[i].sector);
+
+ bio_io_error(bi);
+ bi = nextbi;
+ }
+ }
+ if (bitmap_end)
+ md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
+ RAID5_STRIPE_SECTORS(conf), 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,
+ RAID5_STRIPE_SECTORS(conf), 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,
+ RAID5_STRIPE_SECTORS(conf), 0))
+ abort = 1;
+ }
+ rcu_read_unlock();
+ if (abort)
+ conf->recovery_disabled =
+ conf->mddev->recovery_disabled;
+ }
+ md_done_sync(conf->mddev, RAID5_STRIPE_SECTORS(conf), !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;
+ bool force_rcw = (sh->raid_conf->rmw_level == PARITY_DISABLE_RMW);
+
+
+ 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 (s->failed >= 2 &&
+ (fdev[i]->towrite ||
+ s->failed_num[i] == sh->pd_idx ||
+ s->failed_num[i] == sh->qd_idx) &&
+ !test_bit(R5_UPTODATE, &fdev[i]->flags))
+ /* In max degraded raid6, If the failed disk is P, Q,
+ * or we want to read the failed disk, we need to do
+ * reconstruct-write.
+ */
+ force_rcw = true;
+ }
+
+ /* If we are forced to do a reconstruct-write, 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 (!force_rcw &&
+ 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->to_read && 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 + RAID5_STRIPE_SECTORS(conf)) {
+ wbi2 = r5_next_bio(conf, wbi, dev->sector);
+ md_write_end(conf->mddev);
+ bio_endio(wbi);
+ wbi = wbi2;
+ }
+ md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
+ RAID5_STRIPE_SECTORS(conf),
+ !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);
+ }
+ }
+ }
+ 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);
+ }
+ }
+ 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]];
+ fallthrough;
+ 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(RAID5_STRIPE_SECTORS(conf), &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 +
+ RAID5_STRIPE_SECTORS(conf));
+ } 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);
+ fallthrough;
+ 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(RAID5_STRIPE_SECTORS(conf), &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 +
+ RAID5_STRIPE_SECTORS(conf));
+ } 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, NULL, s,
+ R5_GAS_NOBLOCK | R5_GAS_NOQUIESCE);
+ 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, sh2->dev[dd_idx].offset,
+ sh->dev[i].offset, RAID5_STRIPE_SIZE(conf),
+ &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 + RAID5_STRIPE_SECTORS(conf) &&
+ !is_badblock(rdev, sh->sector, RAID5_STRIPE_SECTORS(conf),
+ &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, RAID5_STRIPE_SECTORS(conf),
+ &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 + RAID5_STRIPE_SECTORS(conf) <= 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();
+}
+
+/*
+ * 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.
+ */
+static int clear_batch_ready(struct stripe_head *sh)
+{
+ 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_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);
+
+ /*
+ * handle_stripe should not continue handle the batched stripe, only
+ * the head of batch list or lone stripe can continue. Otherwise we
+ * could see break_stripe_batch_list warns about the STRIPE_ACTIVE
+ * is set for the batched stripe.
+ */
+ if (clear_batch_ready(sh))
+ return;
+
+ 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 (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, RAID5_STRIPE_SECTORS(conf), 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);
+ } 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, NULL, sh->sector,
+ R5_GAS_PREVIOUS | R5_GAS_NOBLOCK |
+ R5_GAS_NOQUIESCE);
+ 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, RAID5_STRIPE_SECTORS(conf), 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 = rdev_pend_deref(conf->disks[i].rdev);
+ if (!rdev_set_badblocks(rdev, sh->sector,
+ RAID5_STRIPE_SECTORS(conf), 0))
+ md_error(conf->mddev, rdev);
+ rdev_dec_pending(rdev, conf->mddev);
+ }
+ if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
+ rdev_clear_badblocks(rdev, sh->sector,
+ RAID5_STRIPE_SECTORS(conf), 0);
+ rdev_dec_pending(rdev, conf->mddev);
+ }
+ if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
+ rdev = rdev_pend_deref(conf->disks[i].replacement);
+ if (!rdev)
+ /* rdev have been moved down */
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
+ rdev_clear_badblocks(rdev, sh->sector,
+ RAID5_STRIPE_SECTORS(conf), 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)
+ __must_hold(&conf->device_lock)
+{
+ 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)
+ __must_hold(&conf->device_lock)
+{
+ 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 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);
+
+ 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 md_io_acct *md_io_acct = bi->bi_private;
+ struct bio *raid_bi = md_io_acct->orig_bio;
+ struct mddev *mddev;
+ struct r5conf *conf;
+ struct md_rdev *rdev;
+ blk_status_t error = bi->bi_status;
+ unsigned long start_time = md_io_acct->start_time;
+
+ 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) {
+ if (blk_queue_io_stat(raid_bi->bi_bdev->bd_disk->queue))
+ bio_end_io_acct(raid_bi, start_time);
+ 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;
+ struct bio *align_bio;
+ struct md_rdev *rdev;
+ sector_t sector, end_sector, first_bad;
+ int bad_sectors, dd_idx;
+ struct md_io_acct *md_io_acct;
+ bool did_inc;
+
+ if (!in_chunk_boundary(mddev, raid_bio)) {
+ pr_debug("%s: non aligned\n", __func__);
+ return 0;
+ }
+
+ sector = raid5_compute_sector(conf, raid_bio->bi_iter.bi_sector, 0,
+ &dd_idx, NULL);
+ end_sector = sector + bio_sectors(raid_bio);
+
+ rcu_read_lock();
+ if (r5c_big_stripe_cached(conf, sector))
+ goto out_rcu_unlock;
+
+ 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)
+ goto out_rcu_unlock;
+ if (test_bit(Faulty, &rdev->flags) ||
+ !(test_bit(In_sync, &rdev->flags) ||
+ rdev->recovery_offset >= end_sector))
+ goto out_rcu_unlock;
+ }
+
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+
+ if (is_badblock(rdev, sector, bio_sectors(raid_bio), &first_bad,
+ &bad_sectors)) {
+ rdev_dec_pending(rdev, mddev);
+ return 0;
+ }
+
+ align_bio = bio_alloc_clone(rdev->bdev, raid_bio, GFP_NOIO,
+ &mddev->io_acct_set);
+ md_io_acct = container_of(align_bio, struct md_io_acct, bio_clone);
+ raid_bio->bi_next = (void *)rdev;
+ if (blk_queue_io_stat(raid_bio->bi_bdev->bd_disk->queue))
+ md_io_acct->start_time = bio_start_io_acct(raid_bio);
+ md_io_acct->orig_bio = raid_bio;
+
+ align_bio->bi_end_io = raid5_align_endio;
+ align_bio->bi_private = md_io_acct;
+ align_bio->bi_iter.bi_sector = sector;
+
+ /* No reshape active, so we can trust rdev->data_offset */
+ align_bio->bi_iter.bi_sector += rdev->data_offset;
+
+ did_inc = false;
+ if (conf->quiesce == 0) {
+ atomic_inc(&conf->active_aligned_reads);
+ did_inc = true;
+ }
+ /* need a memory barrier to detect the race with raid5_quiesce() */
+ if (!did_inc || smp_load_acquire(&conf->quiesce) != 0) {
+ /* quiesce is in progress, so we need to undo io activation and wait
+ * for it to finish
+ */
+ if (did_inc && atomic_dec_and_test(&conf->active_aligned_reads))
+ wake_up(&conf->wait_for_quiescent);
+ 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_bio, disk_devt(mddev->gendisk),
+ raid_bio->bi_iter.bi_sector);
+ submit_bio_noacct(align_bio);
+ return 1;
+
+out_rcu_unlock:
+ rcu_read_unlock();
+ 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);
+ submit_bio_noacct(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)
+ __must_hold(&conf->device_lock)
+{
+ 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;
+
+ /* We need to handle this when io_uring supports discard/trim */
+ if (WARN_ON_ONCE(bi->bi_opf & REQ_NOWAIT))
+ return;
+
+ if (mddev->reshape_position != MaxSector)
+ /* Skip discard while reshape is happening */
+ return;
+
+ logical_sector = bi->bi_iter.bi_sector & ~((sector_t)RAID5_STRIPE_SECTORS(conf)-1);
+ last_sector = bio_end_sector(bi);
+
+ 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 += RAID5_STRIPE_SECTORS(conf)) {
+ DEFINE_WAIT(w);
+ int d;
+ again:
+ sh = raid5_get_active_stripe(conf, NULL, logical_sector, 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,
+ RAID5_STRIPE_SECTORS(conf),
+ 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 ahead_of_reshape(struct mddev *mddev, sector_t sector,
+ sector_t reshape_sector)
+{
+ return mddev->reshape_backwards ? sector < reshape_sector :
+ sector >= reshape_sector;
+}
+
+static bool range_ahead_of_reshape(struct mddev *mddev, sector_t min,
+ sector_t max, sector_t reshape_sector)
+{
+ return mddev->reshape_backwards ? max < reshape_sector :
+ min >= reshape_sector;
+}
+
+static bool stripe_ahead_of_reshape(struct mddev *mddev, struct r5conf *conf,
+ struct stripe_head *sh)
+{
+ sector_t max_sector = 0, min_sector = MaxSector;
+ bool ret = false;
+ int dd_idx;
+
+ for (dd_idx = 0; dd_idx < sh->disks; dd_idx++) {
+ if (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
+ continue;
+
+ min_sector = min(min_sector, sh->dev[dd_idx].sector);
+ max_sector = max(max_sector, sh->dev[dd_idx].sector);
+ }
+
+ spin_lock_irq(&conf->device_lock);
+
+ if (!range_ahead_of_reshape(mddev, min_sector, max_sector,
+ conf->reshape_progress))
+ /* mismatch, need to try again */
+ ret = true;
+
+ spin_unlock_irq(&conf->device_lock);
+
+ return ret;
+}
+
+static int add_all_stripe_bios(struct r5conf *conf,
+ struct stripe_request_ctx *ctx, struct stripe_head *sh,
+ struct bio *bi, int forwrite, int previous)
+{
+ int dd_idx;
+ int ret = 1;
+
+ spin_lock_irq(&sh->stripe_lock);
+
+ for (dd_idx = 0; dd_idx < sh->disks; dd_idx++) {
+ struct r5dev *dev = &sh->dev[dd_idx];
+
+ if (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
+ continue;
+
+ if (dev->sector < ctx->first_sector ||
+ dev->sector >= ctx->last_sector)
+ continue;
+
+ if (stripe_bio_overlaps(sh, bi, dd_idx, forwrite)) {
+ set_bit(R5_Overlap, &dev->flags);
+ ret = 0;
+ continue;
+ }
+ }
+
+ if (!ret)
+ goto out;
+
+ for (dd_idx = 0; dd_idx < sh->disks; dd_idx++) {
+ struct r5dev *dev = &sh->dev[dd_idx];
+
+ if (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
+ continue;
+
+ if (dev->sector < ctx->first_sector ||
+ dev->sector >= ctx->last_sector)
+ continue;
+
+ __add_stripe_bio(sh, bi, dd_idx, forwrite, previous);
+ clear_bit((dev->sector - ctx->first_sector) >>
+ RAID5_STRIPE_SHIFT(conf), ctx->sectors_to_do);
+ }
+
+out:
+ spin_unlock_irq(&sh->stripe_lock);
+ return ret;
+}
+
+static enum stripe_result make_stripe_request(struct mddev *mddev,
+ struct r5conf *conf, struct stripe_request_ctx *ctx,
+ sector_t logical_sector, struct bio *bi)
+{
+ const int rw = bio_data_dir(bi);
+ enum stripe_result ret;
+ struct stripe_head *sh;
+ sector_t new_sector;
+ int previous = 0, flags = 0;
+ int seq, dd_idx;
+
+ seq = read_seqcount_begin(&conf->gen_lock);
+
+ 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 (ahead_of_reshape(mddev, logical_sector,
+ conf->reshape_progress)) {
+ previous = 1;
+ } else {
+ if (ahead_of_reshape(mddev, logical_sector,
+ conf->reshape_safe)) {
+ spin_unlock_irq(&conf->device_lock);
+ return STRIPE_SCHEDULE_AND_RETRY;
+ }
+ }
+ spin_unlock_irq(&conf->device_lock);
+ }
+
+ new_sector = raid5_compute_sector(conf, logical_sector, previous,
+ &dd_idx, NULL);
+ pr_debug("raid456: %s, sector %llu logical %llu\n", __func__,
+ new_sector, logical_sector);
+
+ if (previous)
+ flags |= R5_GAS_PREVIOUS;
+ if (bi->bi_opf & REQ_RAHEAD)
+ flags |= R5_GAS_NOBLOCK;
+ sh = raid5_get_active_stripe(conf, ctx, new_sector, flags);
+ if (unlikely(!sh)) {
+ /* cannot get stripe, just give-up */
+ bi->bi_status = BLK_STS_IOERR;
+ return STRIPE_FAIL;
+ }
+
+ if (unlikely(previous) &&
+ stripe_ahead_of_reshape(mddev, conf, sh)) {
+ /*
+ * Expansion moved on while waiting for a stripe.
+ * 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.
+ */
+ ret = STRIPE_SCHEDULE_AND_RETRY;
+ goto out_release;
+ }
+
+ if (read_seqcount_retry(&conf->gen_lock, seq)) {
+ /* Might have got the wrong stripe_head by accident */
+ ret = STRIPE_RETRY;
+ goto out_release;
+ }
+
+ if (test_bit(STRIPE_EXPANDING, &sh->state) ||
+ !add_all_stripe_bios(conf, ctx, sh, bi, rw, previous)) {
+ /*
+ * Stripe is busy expanding or add failed due to
+ * overlap. Flush everything and wait a while.
+ */
+ md_wakeup_thread(mddev->thread);
+ ret = STRIPE_SCHEDULE_AND_RETRY;
+ goto out_release;
+ }
+
+ if (stripe_can_batch(sh)) {
+ stripe_add_to_batch_list(conf, sh, ctx->batch_last);
+ if (ctx->batch_last)
+ raid5_release_stripe(ctx->batch_last);
+ atomic_inc(&sh->count);
+ ctx->batch_last = sh;
+ }
+
+ if (ctx->do_flush) {
+ set_bit(STRIPE_R5C_PREFLUSH, &sh->state);
+ /* we only need flush for one stripe */
+ ctx->do_flush = false;
+ }
+
+ 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);
+ return STRIPE_SUCCESS;
+
+out_release:
+ raid5_release_stripe(sh);
+ return ret;
+}
+
+/*
+ * If the bio covers multiple data disks, find sector within the bio that has
+ * the lowest chunk offset in the first chunk.
+ */
+static sector_t raid5_bio_lowest_chunk_sector(struct r5conf *conf,
+ struct bio *bi)
+{
+ int sectors_per_chunk = conf->chunk_sectors;
+ int raid_disks = conf->raid_disks;
+ int dd_idx;
+ struct stripe_head sh;
+ unsigned int chunk_offset;
+ sector_t r_sector = bi->bi_iter.bi_sector & ~((sector_t)RAID5_STRIPE_SECTORS(conf)-1);
+ sector_t sector;
+
+ /* We pass in fake stripe_head to get back parity disk numbers */
+ sector = raid5_compute_sector(conf, r_sector, 0, &dd_idx, &sh);
+ chunk_offset = sector_div(sector, sectors_per_chunk);
+ if (sectors_per_chunk - chunk_offset >= bio_sectors(bi))
+ return r_sector;
+ /*
+ * Bio crosses to the next data disk. Check whether it's in the same
+ * chunk.
+ */
+ dd_idx++;
+ while (dd_idx == sh.pd_idx || dd_idx == sh.qd_idx)
+ dd_idx++;
+ if (dd_idx >= raid_disks)
+ return r_sector;
+ return r_sector + sectors_per_chunk - chunk_offset;
+}
+
+static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
+{
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ struct r5conf *conf = mddev->private;
+ sector_t logical_sector;
+ struct stripe_request_ctx ctx = {};
+ const int rw = bio_data_dir(bi);
+ enum stripe_result res;
+ int s, stripe_cnt;
+
+ 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
+ */
+ ctx.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)RAID5_STRIPE_SECTORS(conf)-1);
+ ctx.first_sector = logical_sector;
+ ctx.last_sector = bio_end_sector(bi);
+ bi->bi_next = NULL;
+
+ stripe_cnt = DIV_ROUND_UP_SECTOR_T(ctx.last_sector - logical_sector,
+ RAID5_STRIPE_SECTORS(conf));
+ bitmap_set(ctx.sectors_to_do, 0, stripe_cnt);
+
+ pr_debug("raid456: %s, logical %llu to %llu\n", __func__,
+ bi->bi_iter.bi_sector, ctx.last_sector);
+
+ /* Bail out if conflicts with reshape and REQ_NOWAIT is set */
+ if ((bi->bi_opf & REQ_NOWAIT) &&
+ (conf->reshape_progress != MaxSector) &&
+ !ahead_of_reshape(mddev, logical_sector, conf->reshape_progress) &&
+ ahead_of_reshape(mddev, logical_sector, conf->reshape_safe)) {
+ bio_wouldblock_error(bi);
+ if (rw == WRITE)
+ md_write_end(mddev);
+ return true;
+ }
+ md_account_bio(mddev, &bi);
+
+ /*
+ * Lets start with the stripe with the lowest chunk offset in the first
+ * chunk. That has the best chances of creating IOs adjacent to
+ * previous IOs in case of sequential IO and thus creates the most
+ * sequential IO pattern. We don't bother with the optimization when
+ * reshaping as the performance benefit is not worth the complexity.
+ */
+ if (likely(conf->reshape_progress == MaxSector))
+ logical_sector = raid5_bio_lowest_chunk_sector(conf, bi);
+ s = (logical_sector - ctx.first_sector) >> RAID5_STRIPE_SHIFT(conf);
+
+ add_wait_queue(&conf->wait_for_overlap, &wait);
+ while (1) {
+ res = make_stripe_request(mddev, conf, &ctx, logical_sector,
+ bi);
+ if (res == STRIPE_FAIL)
+ break;
+
+ if (res == STRIPE_RETRY)
+ continue;
+
+ if (res == STRIPE_SCHEDULE_AND_RETRY) {
+ /*
+ * Must release the reference to batch_last before
+ * scheduling and waiting for work to be done,
+ * otherwise the batch_last stripe head could prevent
+ * raid5_activate_delayed() from making progress
+ * and thus deadlocking.
+ */
+ if (ctx.batch_last) {
+ raid5_release_stripe(ctx.batch_last);
+ ctx.batch_last = NULL;
+ }
+
+ wait_woken(&wait, TASK_UNINTERRUPTIBLE,
+ MAX_SCHEDULE_TIMEOUT);
+ continue;
+ }
+
+ s = find_next_bit_wrap(ctx.sectors_to_do, stripe_cnt, s);
+ if (s == stripe_cnt)
+ break;
+
+ logical_sector = ctx.first_sector +
+ (s << RAID5_STRIPE_SHIFT(conf));
+ }
+ remove_wait_queue(&conf->wait_for_overlap, &wait);
+
+ if (ctx.batch_last)
+ raid5_release_stripe(ctx.batch_last);
+
+ 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_dirent_safe(mddev->sysfs_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_dirent_safe(mddev->sysfs_completed);
+ }
+
+ INIT_LIST_HEAD(&stripes);
+ for (i = 0; i < reshape_sectors; i += RAID5_STRIPE_SECTORS(conf)) {
+ int j;
+ int skipped_disk = 0;
+ sh = raid5_get_active_stripe(conf, NULL, stripe_addr+i,
+ R5_GAS_NOQUIESCE);
+ 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, RAID5_STRIPE_SIZE(conf));
+ 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, NULL, first_sector,
+ R5_GAS_PREVIOUS | R5_GAS_NOQUIESCE);
+ set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
+ set_bit(STRIPE_HANDLE, &sh->state);
+ raid5_release_stripe(sh);
+ first_sector += RAID5_STRIPE_SECTORS(conf);
+ }
+ /* 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_dirent_safe(mddev->sysfs_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 >= RAID5_STRIPE_SECTORS(conf)) {
+ /* we can skip this block, and probably more */
+ do_div(sync_blocks, RAID5_STRIPE_SECTORS(conf));
+ *skipped = 1;
+ /* keep things rounded to whole stripes */
+ return sync_blocks * RAID5_STRIPE_SECTORS(conf);
+ }
+
+ md_bitmap_cond_end_sync(mddev->bitmap, sector_nr, false);
+
+ sh = raid5_get_active_stripe(conf, NULL, sector_nr,
+ R5_GAS_NOBLOCK);
+ if (sh == NULL) {
+ sh = raid5_get_active_stripe(conf, NULL, sector_nr, 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 = rcu_dereference(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 RAID5_STRIPE_SECTORS(conf);
+}
+
+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)RAID5_STRIPE_SECTORS(conf)-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 += RAID5_STRIPE_SECTORS(conf),
+ sector += RAID5_STRIPE_SECTORS(conf),
+ scnt++) {
+
+ if (scnt < offset)
+ /* already done this stripe */
+ continue;
+
+ sh = raid5_get_active_stripe(conf, NULL, sector,
+ R5_GAS_NOBLOCK | R5_GAS_NOQUIESCE);
+ 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)
+ __must_hold(&conf->device_lock)
+{
+ 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);
+
+ /*
+ * Waiting on MD_SB_CHANGE_PENDING below may deadlock
+ * seeing md_check_recovery() is needed to clear
+ * the flag when using mdmon.
+ */
+ continue;
+ }
+
+ 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);
+ 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_stripe_size(struct mddev *mddev, char *page)
+{
+ struct r5conf *conf;
+ int ret = 0;
+
+ spin_lock(&mddev->lock);
+ conf = mddev->private;
+ if (conf)
+ ret = sprintf(page, "%lu\n", RAID5_STRIPE_SIZE(conf));
+ spin_unlock(&mddev->lock);
+ return ret;
+}
+
+#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
+static ssize_t
+raid5_store_stripe_size(struct mddev *mddev, const char *page, size_t len)
+{
+ struct r5conf *conf;
+ unsigned long new;
+ int err;
+ int size;
+
+ if (len >= PAGE_SIZE)
+ return -EINVAL;
+ if (kstrtoul(page, 10, &new))
+ return -EINVAL;
+
+ /*
+ * The value should not be bigger than PAGE_SIZE. It requires to
+ * be multiple of DEFAULT_STRIPE_SIZE and the value should be power
+ * of two.
+ */
+ if (new % DEFAULT_STRIPE_SIZE != 0 ||
+ new > PAGE_SIZE || new == 0 ||
+ new != roundup_pow_of_two(new))
+ return -EINVAL;
+
+ err = mddev_lock(mddev);
+ if (err)
+ return err;
+
+ conf = mddev->private;
+ if (!conf) {
+ err = -ENODEV;
+ goto out_unlock;
+ }
+
+ if (new == conf->stripe_size)
+ goto out_unlock;
+
+ pr_debug("md/raid: change stripe_size from %lu to %lu\n",
+ conf->stripe_size, new);
+
+ if (mddev->sync_thread ||
+ test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
+ mddev->reshape_position != MaxSector ||
+ mddev->sysfs_active) {
+ err = -EBUSY;
+ goto out_unlock;
+ }
+
+ mddev_suspend(mddev);
+ mutex_lock(&conf->cache_size_mutex);
+ size = conf->max_nr_stripes;
+
+ shrink_stripes(conf);
+
+ conf->stripe_size = new;
+ conf->stripe_shift = ilog2(new) - 9;
+ conf->stripe_sectors = new >> 9;
+ if (grow_stripes(conf, size)) {
+ pr_warn("md/raid:%s: couldn't allocate buffers\n",
+ mdname(mddev));
+ err = -ENOMEM;
+ }
+ mutex_unlock(&conf->cache_size_mutex);
+ mddev_resume(mddev);
+
+out_unlock:
+ mddev_unlock(mddev);
+ return err ?: len;
+}
+
+static struct md_sysfs_entry
+raid5_stripe_size = __ATTR(stripe_size, 0644,
+ raid5_show_stripe_size,
+ raid5_store_stripe_size);
+#else
+static struct md_sysfs_entry
+raid5_stripe_size = __ATTR(stripe_size, 0444,
+ raid5_show_stripe_size,
+ NULL);
+#endif
+
+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) {
+ struct request_queue *q = mddev->queue;
+
+ mddev_suspend(mddev);
+ conf->skip_copy = new;
+ if (new)
+ blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
+ else
+ blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
+ 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,
+ 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;
+
+ 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, &new_groups);
+ if (!err) {
+ spin_lock_irq(&conf->device_lock);
+ conf->group_cnt = group_cnt;
+ conf->worker_cnt_per_group = new;
+ 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,
+ &raid5_stripe_size.attr,
+ &r5c_journal_mode.attr,
+ &ppl_write_hint.attr,
+ NULL,
+};
+static const struct attribute_group raid5_attrs_group = {
+ .name = NULL,
+ .attrs = raid5_attrs,
+};
+
+static int alloc_thread_groups(struct r5conf *conf, int cnt, int *group_cnt,
+ struct r5worker_group **worker_groups)
+{
+ int i, j, k;
+ ssize_t size;
+ struct r5worker *workers;
+
+ 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);
+ percpu->spare_page = NULL;
+ kvfree(percpu->scribble);
+ 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->spare_page)
+ return -ENOMEM;
+ }
+
+ if (scribble_alloc(percpu,
+ max(conf->raid_disks,
+ conf->previous_raid_disks),
+ max(conf->chunk_sectors,
+ conf->prev_chunk_sectors)
+ / RAID5_STRIPE_SECTORS(conf))) {
+ free_scratch_buffer(conf, percpu);
+ return -ENOMEM;
+ }
+
+ local_lock_init(&percpu->lock);
+ 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;
+ struct r5worker_group *new_group;
+ int ret = -ENOMEM;
+
+ 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;
+
+#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
+ conf->stripe_size = DEFAULT_STRIPE_SIZE;
+ conf->stripe_shift = ilog2(DEFAULT_STRIPE_SIZE) - 9;
+ conf->stripe_sectors = DEFAULT_STRIPE_SIZE >> 9;
+#endif
+ 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, &new_group)) {
+ conf->group_cnt = group_cnt;
+ conf->worker_cnt_per_group = 0;
+ conf->worker_groups = new_group;
+ } else
+ goto abort;
+ spin_lock_init(&conf->device_lock);
+ seqcount_spinlock_init(&conf->gen_lock, &conf->device_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 (bdev_nonrot(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;
+
+ ret = -ENOMEM;
+ conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!conf->stripe_hashtbl)
+ 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;
+ ret = raid5_alloc_percpu(conf);
+ if (ret)
+ goto abort;
+
+ pr_debug("raid456: run(%s) called.\n", mdname(mddev));
+
+ ret = -EIO;
+ 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;
+ RCU_INIT_POINTER(disk->replacement, rdev);
+ } else {
+ if (disk->rdev)
+ goto abort;
+ RCU_INIT_POINTER(disk->rdev, rdev);
+ }
+
+ if (test_bit(In_sync, &rdev->flags)) {
+ pr_info("md/raid:%s: device %pg operational as raid disk %d\n",
+ mdname(mddev), rdev->bdev, 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) / RAID5_STRIPE_SIZE(conf)) * 4,
+ ((mddev->new_chunk_sectors << 9) / RAID5_STRIPE_SIZE(conf)) * 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);
+ ret = -ENOMEM;
+ 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;
+ ret = register_shrinker(&conf->shrinker, "md-raid5:%s", mdname(mddev));
+ if (ret) {
+ 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));
+ ret = -ENOMEM;
+ goto abort;
+ }
+
+ return conf;
+
+ abort:
+ if (conf)
+ free_conf(conf);
+ return ERR_PTR(ret);
+}
+
+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 void raid5_set_io_opt(struct r5conf *conf)
+{
+ blk_queue_io_opt(conf->mddev->queue, (conf->chunk_sectors << 9) *
+ (conf->raid_disks - conf->max_degraded));
+}
+
+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, ret = 0;
+ long long min_offset_diff = 0;
+ int first = 1;
+
+ if (acct_bioset_init(mddev)) {
+ pr_err("md/raid456:%s: alloc acct bioset failed.\n", mdname(mddev));
+ return -ENOMEM;
+ }
+
+ if (mddev_init_writes_pending(mddev) < 0) {
+ ret = -ENOMEM;
+ goto exit_acct_set;
+ }
+
+ 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));
+ ret = -EINVAL;
+ goto exit_acct_set;
+ }
+
+ 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));
+ ret = -EINVAL;
+ goto exit_acct_set;
+ }
+
+ if (mddev->new_level != mddev->level) {
+ pr_warn("md/raid:%s: unsupported reshape required - aborting.\n",
+ mdname(mddev));
+ ret = -EINVAL;
+ goto exit_acct_set;
+ }
+ 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));
+ ret = -EINVAL;
+ goto exit_acct_set;
+ }
+ 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));
+ ret = -EINVAL;
+ goto exit_acct_set;
+ }
+ } 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));
+ ret = -EINVAL;
+ goto exit_acct_set;
+ }
+ 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)) {
+ ret = PTR_ERR(conf);
+ goto exit_acct_set;
+ }
+
+ 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 = rdev_mdlock_deref(mddev, conf->disks[i].rdev);
+ if (!rdev && conf->disks[i].replacement) {
+ /* The replacement is all we have yet */
+ rdev = rdev_mdlock_deref(mddev,
+ conf->disks[i].replacement);
+ conf->disks[i].replacement = NULL;
+ clear_bit(Replacement, &rdev->flags);
+ rcu_assign_pointer(conf->disks[i].rdev, rdev);
+ }
+ if (!rdev)
+ continue;
+ if (rcu_access_pointer(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 &= ~((sector_t)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);
+
+ chunk_size = mddev->chunk_sectors << 9;
+ blk_queue_io_min(mddev->queue, chunk_size);
+ raid5_set_io_opt(conf);
+ 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;
+ stripe = roundup_pow_of_two(stripe);
+ mddev->queue->limits.discard_granularity = stripe;
+
+ 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_max_discard_sectors(mddev->queue, 0);
+
+ /*
+ * Requests require having a bitmap for each stripe.
+ * Limit the max sectors based on this.
+ */
+ blk_queue_max_hw_sectors(mddev->queue,
+ RAID5_MAX_REQ_STRIPES << RAID5_STRIPE_SHIFT(conf));
+
+ /* No restrictions on the number of segments in the request */
+ blk_queue_max_segments(mddev->queue, USHRT_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));
+ ret = -EIO;
+exit_acct_set:
+ acct_bioset_exit(mddev);
+ return ret;
+}
+
+static void raid5_free(struct mddev *mddev, void *priv)
+{
+ struct r5conf *conf = priv;
+
+ free_conf(conf);
+ acct_bioset_exit(mddev);
+ 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)
+{
+ struct md_rdev *rdev;
+ int i;
+
+ 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);
+
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks; i++) {
+ rdev = rcu_dereference(conf->disks[i].rdev);
+ if (rdev)
+ pr_debug(" disk %d, o:%d, dev:%pg\n",
+ i, !test_bit(Faulty, &rdev->flags),
+ rdev->bdev);
+ }
+ rcu_read_unlock();
+}
+
+static int raid5_spare_active(struct mddev *mddev)
+{
+ int i;
+ struct r5conf *conf = mddev->private;
+ struct md_rdev *rdev, *replacement;
+ int count = 0;
+ unsigned long flags;
+
+ for (i = 0; i < conf->raid_disks; i++) {
+ rdev = rdev_mdlock_deref(mddev, conf->disks[i].rdev);
+ replacement = rdev_mdlock_deref(mddev,
+ conf->disks[i].replacement);
+ if (replacement
+ && replacement->recovery_offset == MaxSector
+ && !test_bit(Faulty, &replacement->flags)
+ && !test_and_set_bit(In_sync, &replacement->flags)) {
+ /* Replacement has just become active. */
+ if (!rdev
+ || !test_and_clear_bit(In_sync, &rdev->flags))
+ count++;
+ if (rdev) {
+ /* Replaced device not technically faulty,
+ * but we need to be sure it gets removed
+ * and never re-added.
+ */
+ set_bit(Faulty, &rdev->flags);
+ sysfs_notify_dirent_safe(
+ rdev->sysfs_state);
+ }
+ sysfs_notify_dirent_safe(replacement->sysfs_state);
+ } else if (rdev
+ && rdev->recovery_offset == MaxSector
+ && !test_bit(Faulty, &rdev->flags)
+ && !test_and_set_bit(In_sync, &rdev->flags)) {
+ count++;
+ sysfs_notify_dirent_safe(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 __rcu **rdevp;
+ struct disk_info *p;
+ struct md_rdev *tmp;
+
+ 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 (unlikely(number >= conf->pool_size))
+ return 0;
+ p = conf->disks + number;
+ if (rdev == rcu_access_pointer(p->rdev))
+ rdevp = &p->rdev;
+ else if (rdev == rcu_access_pointer(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) &&
+ (!rcu_access_pointer(p->replacement) ||
+ rcu_access_pointer(p->replacement) == rdev) &&
+ number < conf->raid_disks) {
+ err = -EBUSY;
+ goto abort;
+ }
+ *rdevp = NULL;
+ if (!test_bit(RemoveSynchronized, &rdev->flags)) {
+ lockdep_assert_held(&mddev->reconfig_mutex);
+ synchronize_rcu();
+ if (atomic_read(&rdev->nr_pending)) {
+ /* lost the race, try later */
+ err = -EBUSY;
+ rcu_assign_pointer(*rdevp, rdev);
+ }
+ }
+ if (!err) {
+ err = log_modify(conf, rdev, false);
+ if (err)
+ goto abort;
+ }
+
+ tmp = rcu_access_pointer(p->replacement);
+ if (tmp) {
+ /* We must have just cleared 'rdev' */
+ rcu_assign_pointer(p->rdev, tmp);
+ clear_bit(Replacement, &tmp->flags);
+ smp_mb(); /* Make sure other CPUs may see both as identical
+ * but will never see neither - if they are careful
+ */
+ rcu_assign_pointer(p->replacement, NULL);
+
+ if (!err)
+ err = log_modify(conf, tmp, 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;
+ struct md_rdev *tmp;
+ 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 >= first &&
+ rdev->saved_raid_disk <= last &&
+ 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;
+ tmp = rdev_mdlock_deref(mddev, p->rdev);
+ if (test_bit(WantReplacement, &tmp->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) / RAID5_STRIPE_SIZE(conf)) * 4
+ > conf->min_nr_stripes ||
+ ((mddev->new_chunk_sectors << 9) / RAID5_STRIPE_SIZE(conf)) * 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)
+ / RAID5_STRIPE_SIZE(conf))*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;
+
+ /* Failure here is OK */
+ sysfs_link_rdev(mddev, rdev);
+ }
+ } 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();
+ 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);
+
+ if (conf->mddev->queue)
+ raid5_set_io_opt(conf);
+ }
+}
+
+/* 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;
+ struct md_rdev *rdev;
+
+ 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++) {
+ rdev = rdev_mdlock_deref(mddev,
+ conf->disks[d].rdev);
+ if (rdev)
+ clear_bit(In_sync, &rdev->flags);
+ rdev = rdev_mdlock_deref(mddev,
+ 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);
+ /* need a memory barrier to make sure read_one_chunk() sees
+ * quiesce started and reverts to slow (locked) path.
+ */
+ smp_store_release(&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) < RAID5_STRIPE_SIZE((struct r5conf *)mddev->private))
+ /* 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) {
+ mddev_suspend(mddev);
+ log_exit(conf);
+ mddev_resume(mddev);
+ }
+ }
+ } 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,
+ .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,
+ .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,
+ .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");