1 files changed, 92 insertions, 90 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 94829804ab7f..81abefc172d9 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -156,13 +156,16 @@ static inline int raid6_next_disk(int disk, int raid_disks)
 static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
                              int *count, int syndrome_disks)
 {
-        int slot;
+        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;
-        slot = (*count)++;
+        if (!sh->ddf_layout)
+                (*count)++;
         return slot;
 }
 
@@ -717,7 +720,7 @@ static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
         int i;
 
         for (i = 0; i < disks; i++)
-                srcs[i] = (void *)raid6_empty_zero_page;
+                srcs[i] = NULL;
 
         count = 0;
         i = d0_idx;
@@ -727,9 +730,8 @@ static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
                 srcs[slot] = sh->dev[i].page;
                 i = raid6_next_disk(i, disks);
         } while (i != d0_idx);
-        BUG_ON(count != syndrome_disks);
 
-        return count;
+        return syndrome_disks;
 }
 
 static struct dma_async_tx_descriptor *
@@ -814,7 +816,7 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
          * slot number conversion for 'faila' and 'failb'
          */
         for (i = 0; i < disks ; i++)
-                blocks[i] = (void *)raid6_empty_zero_page;
+                blocks[i] = NULL;
         count = 0;
         i = d0_idx;
         do {
@@ -828,7 +830,6 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
                         failb = slot;
                 i = raid6_next_disk(i, disks);
         } while (i != d0_idx);
-        BUG_ON(count != syndrome_disks);
 
         BUG_ON(faila == failb);
         if (failb < faila)
@@ -845,7 +846,7 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
                         init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
                                           ops_complete_compute, sh,
                                           to_addr_conv(sh, percpu));
-                        return async_gen_syndrome(blocks, 0, count+2,
+                        return async_gen_syndrome(blocks, 0, syndrome_disks+2,
                                                   STRIPE_SIZE, &submit);
                 } else {
                         struct page *dest;
@@ -1139,7 +1140,7 @@ static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu
                            &sh->ops.zero_sum_result, percpu->spare_page, &submit);
 }
 
-static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
+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;
@@ -1204,22 +1205,55 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
         put_cpu();
 }
 
+#ifdef CONFIG_MULTICORE_RAID456
+static void async_run_ops(void *param, async_cookie_t cookie)
+{
+        struct stripe_head *sh = param;
+        unsigned long ops_request = sh->ops.request;
+
+        clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state);
+        wake_up(&sh->ops.wait_for_ops);
+
+        __raid_run_ops(sh, ops_request);
+        release_stripe(sh);
+}
+
+static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
+{
+        /* since handle_stripe can be called outside of raid5d context
+         * we need to ensure sh->ops.request is de-staged before another
+         * request arrives
+         */
+        wait_event(sh->ops.wait_for_ops,
+                   !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state));
+        sh->ops.request = ops_request;
+
+        atomic_inc(&sh->count);
+        async_schedule(async_run_ops, sh);
+}
+#else
+#define raid_run_ops __raid_run_ops
+#endif
+
 static int grow_one_stripe(raid5_conf_t *conf)
 {
         struct stripe_head *sh;
+        int disks = max(conf->raid_disks, conf->previous_raid_disks);
         sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
         if (!sh)
                 return 0;
-        memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
+        memset(sh, 0, sizeof(*sh) + (disks-1)*sizeof(struct r5dev));
         sh->raid_conf = conf;
         spin_lock_init(&sh->lock);
+        #ifdef CONFIG_MULTICORE_RAID456
+        init_waitqueue_head(&sh->ops.wait_for_ops);
+        #endif
 
-        if (grow_buffers(sh, conf->raid_disks)) {
-                shrink_buffers(sh, conf->raid_disks);
+        if (grow_buffers(sh, disks)) {
+                shrink_buffers(sh, disks);
                 kmem_cache_free(conf->slab_cache, sh);
                 return 0;
         }
-        sh->disks = conf->raid_disks;
         /* we just created an active stripe so... */
         atomic_set(&sh->count, 1);
         atomic_inc(&conf->active_stripes);
@@ -1231,7 +1265,7 @@ static int grow_one_stripe(raid5_conf_t *conf)
 static int grow_stripes(raid5_conf_t *conf, int num)
 {
         struct kmem_cache *sc;
-        int devs = conf->raid_disks;
+        int devs = max(conf->raid_disks, conf->previous_raid_disks);
 
         sprintf(conf->cache_name[0],
                 "raid%d-%s", conf->level, mdname(conf->mddev));
@@ -1329,6 +1363,9 @@ static int resize_stripes(raid5_conf_t *conf, int newsize)
 
                 nsh->raid_conf = conf;
                 spin_lock_init(&nsh->lock);
+                #ifdef CONFIG_MULTICORE_RAID456
+                init_waitqueue_head(&nsh->ops.wait_for_ops);
+                #endif
 
                 list_add(&nsh->lru, &newstripes);
         }
@@ -1899,10 +1936,15 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
                 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 if (i > sh->pd_idx)
-                                i -= 2; /* D D Q P D */
+                        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:
@@ -2896,7 +2938,7 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
  *
  */
 
-static bool handle_stripe5(struct stripe_head *sh)
+static void handle_stripe5(struct stripe_head *sh)
 {
         raid5_conf_t *conf = sh->raid_conf;
         int disks = sh->disks, i;
@@ -3167,11 +3209,9 @@ static bool handle_stripe5(struct stripe_head *sh)
         ops_run_io(sh, &s);
 
         return_io(return_bi);
-
-        return blocked_rdev == NULL;
 }
 
-static bool handle_stripe6(struct stripe_head *sh)
+static void handle_stripe6(struct stripe_head *sh)
 {
         raid5_conf_t *conf = sh->raid_conf;
         int disks = sh->disks;
@@ -3455,17 +3495,14 @@ static bool handle_stripe6(struct stripe_head *sh)
         ops_run_io(sh, &s);
 
         return_io(return_bi);
-
-        return blocked_rdev == NULL;
 }
 
-/* returns true if the stripe was handled */
-static bool handle_stripe(struct stripe_head *sh)
+static void handle_stripe(struct stripe_head *sh)
 {
         if (sh->raid_conf->level == 6)
-                return handle_stripe6(sh);
+                handle_stripe6(sh);
         else
-                return handle_stripe5(sh);
+                handle_stripe5(sh);
 }
 
 static void raid5_activate_delayed(raid5_conf_t *conf)
@@ -3503,9 +3540,10 @@ static void unplug_slaves(mddev_t *mddev)
 {
         raid5_conf_t *conf = mddev->private;
         int i;
+        int devs = max(conf->raid_disks, conf->previous_raid_disks);
 
         rcu_read_lock();
-        for (i = 0; i < conf->raid_disks; i++) {
+        for (i = 0; i < devs; i++) {
                 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
                 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
                         struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
@@ -4277,9 +4315,7 @@ static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *ski
         clear_bit(STRIPE_INSYNC, &sh->state);
         spin_unlock(&sh->lock);
 
-        /* wait for any blocked device to be handled */
-        while (unlikely(!handle_stripe(sh)))
-                ;
+        handle_stripe(sh);
         release_stripe(sh);
 
         return STRIPE_SECTORS;
@@ -4349,37 +4385,6 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
         return handled;
 }
 
-#ifdef CONFIG_MULTICORE_RAID456
-static void __process_stripe(void *param, async_cookie_t cookie)
-{
-        struct stripe_head *sh = param;
-
-        handle_stripe(sh);
-        release_stripe(sh);
-}
-
-static void process_stripe(struct stripe_head *sh, struct list_head *domain)
-{
-        async_schedule_domain(__process_stripe, sh, domain);
-}
-
-static void synchronize_stripe_processing(struct list_head *domain)
-{
-        async_synchronize_full_domain(domain);
-}
-#else
-static void process_stripe(struct stripe_head *sh, struct list_head *domain)
-{
-        handle_stripe(sh);
-        release_stripe(sh);
-        cond_resched();
-}
-
-static void synchronize_stripe_processing(struct list_head *domain)
-{
-}
-#endif
-
 
 /*
  * This is our raid5 kernel thread.
@@ -4393,7 +4398,6 @@ static void raid5d(mddev_t *mddev)
         struct stripe_head *sh;
         raid5_conf_t *conf = mddev->private;
         int handled;
-        LIST_HEAD(raid_domain);
 
         pr_debug("+++ raid5d active\n");
 
@@ -4430,7 +4434,9 @@ static void raid5d(mddev_t *mddev)
                 spin_unlock_irq(&conf->device_lock);
                 
                 handled++;
-                process_stripe(sh, &raid_domain);
+                handle_stripe(sh);
+                release_stripe(sh);
+                cond_resched();
 
                 spin_lock_irq(&conf->device_lock);
         }
@@ -4438,7 +4444,6 @@ static void raid5d(mddev_t *mddev)
 
         spin_unlock_irq(&conf->device_lock);
 
-        synchronize_stripe_processing(&raid_domain);
         async_tx_issue_pending_all();
         unplug_slaves(mddev);
 
@@ -4558,13 +4563,9 @@ raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
 
         if (!sectors)
                 sectors = mddev->dev_sectors;
-        if (!raid_disks) {
+        if (!raid_disks)
                 /* size is defined by the smallest of previous and new size */
-                if (conf->raid_disks < conf->previous_raid_disks)
-                        raid_disks = conf->raid_disks;
-                else
-                        raid_disks = conf->previous_raid_disks;
-        }
+                raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
 
         sectors &= ~((sector_t)mddev->chunk_sectors - 1);
         sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
@@ -4665,7 +4666,7 @@ static int raid5_alloc_percpu(raid5_conf_t *conf)
                         }
                         per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
                 }
-                scribble = kmalloc(scribble_len(conf->raid_disks), GFP_KERNEL);
+                scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
                 if (!scribble) {
                         err = -ENOMEM;
                         break;
@@ -4686,7 +4687,7 @@ static int raid5_alloc_percpu(raid5_conf_t *conf)
 static raid5_conf_t *setup_conf(mddev_t *mddev)
 {
         raid5_conf_t *conf;
-        int raid_disk, memory;
+        int raid_disk, memory, max_disks;
         mdk_rdev_t *rdev;
         struct disk_info *disk;
 
@@ -4722,15 +4723,28 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
         conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
         if (conf == NULL)
                 goto abort;
+        spin_lock_init(&conf->device_lock);
+        init_waitqueue_head(&conf->wait_for_stripe);
+        init_waitqueue_head(&conf->wait_for_overlap);
+        INIT_LIST_HEAD(&conf->handle_list);
+        INIT_LIST_HEAD(&conf->hold_list);
+        INIT_LIST_HEAD(&conf->delayed_list);
+        INIT_LIST_HEAD(&conf->bitmap_list);
+        INIT_LIST_HEAD(&conf->inactive_list);
+        atomic_set(&conf->active_stripes, 0);
+        atomic_set(&conf->preread_active_stripes, 0);
+        atomic_set(&conf->active_aligned_reads, 0);
+        conf->bypass_threshold = BYPASS_THRESHOLD;
 
         conf->raid_disks = mddev->raid_disks;
-        conf->scribble_len = scribble_len(conf->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->scribble_len = scribble_len(max_disks);
 
-        conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
+        conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
                               GFP_KERNEL);
         if (!conf->disks)
                 goto abort;
@@ -4744,24 +4758,11 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
         if (raid5_alloc_percpu(conf) != 0)
                 goto abort;
 
-        spin_lock_init(&conf->device_lock);
-        init_waitqueue_head(&conf->wait_for_stripe);
-        init_waitqueue_head(&conf->wait_for_overlap);
-        INIT_LIST_HEAD(&conf->handle_list);
-        INIT_LIST_HEAD(&conf->hold_list);
-        INIT_LIST_HEAD(&conf->delayed_list);
-        INIT_LIST_HEAD(&conf->bitmap_list);
-        INIT_LIST_HEAD(&conf->inactive_list);
-        atomic_set(&conf->active_stripes, 0);
-        atomic_set(&conf->preread_active_stripes, 0);
-        atomic_set(&conf->active_aligned_reads, 0);
-        conf->bypass_threshold = BYPASS_THRESHOLD;
-
         pr_debug("raid5: run(%s) called.\n", mdname(mddev));
 
         list_for_each_entry(rdev, &mddev->disks, same_set) {
                 raid_disk = rdev->raid_disk;
-                if (raid_disk >= conf->raid_disks
+                if (raid_disk >= max_disks
                     || raid_disk < 0)
                         continue;
                 disk = conf->disks + raid_disk;
@@ -4793,7 +4794,7 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
         }
 
         memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
-                 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
+                 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
         if (grow_stripes(conf, conf->max_nr_stripes)) {
                 printk(KERN_ERR
                         "raid5: couldn't allocate %dkB for buffers\n", memory);
@@ -4918,7 +4919,8 @@ static int run(mddev_t *mddev)
                     test_bit(In_sync, &rdev->flags))
                         working_disks++;
 
-        mddev->degraded = conf->raid_disks - working_disks;
+        mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks)
+                           - working_disks);
 
         if (mddev->degraded > conf->max_degraded) {
                 printk(KERN_ERR "raid5: not enough operational devices for %s"