Pull bugzilla-5452 into release branch

[sfrench/cifs-2.6.git] / drivers / md / raid10.c

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index ab90a6d1202043f7d332fe5f613be414845f1107..1440935414e63825adfb5278d2aad8d0be6e1822 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1117,8 +1117,7 @@ static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
        for (i=0; i<conf->copies; i++)
                if (r10_bio->devs[i].bio == bio)
                        break;
-       if (i == conf->copies)
-               BUG();
+       BUG_ON(i == conf->copies);
        update_head_pos(i, r10_bio);
        d = r10_bio->devs[i].devnum;
 
@@ -1408,43 +1407,54 @@ static void raid10d(mddev_t *mddev)
                                if (s > (PAGE_SIZE>>9))
                                        s = PAGE_SIZE >> 9;
 
+                               rcu_read_lock();
                                do {
                                        int d = r10_bio->devs[sl].devnum;
-                                       rdev = conf->mirrors[d].rdev;
+                                       rdev = rcu_dereference(conf->mirrors[d].rdev);
                                        if (rdev &&
-                                           test_bit(In_sync, &rdev->flags) &&
-                                           sync_page_io(rdev->bdev,
-                                                        r10_bio->devs[sl].addr +
-                                                        sect + rdev->data_offset,
-                                                        s<<9,
-                                                        conf->tmppage, READ))
-                                               success = 1;
-                                       else {
-                                               sl++;
-                                               if (sl == conf->copies)
-                                                       sl = 0;
+                                           test_bit(In_sync, &rdev->flags)) {
+                                               atomic_inc(&rdev->nr_pending);
+                                               rcu_read_unlock();
+                                               success = sync_page_io(rdev->bdev,
+                                                                      r10_bio->devs[sl].addr +
+                                                                      sect + rdev->data_offset,
+                                                                      s<<9,
+                                                                      conf->tmppage, READ);
+                                               rdev_dec_pending(rdev, mddev);
+                                               rcu_read_lock();
+                                               if (success)
+                                                       break;
                                        }
+                                       sl++;
+                                       if (sl == conf->copies)
+                                               sl = 0;
                                } while (!success && sl != r10_bio->read_slot);
+                               rcu_read_unlock();
 
                                if (success) {
                                        int start = sl;
                                        /* write it back and re-read */
+                                       rcu_read_lock();
                                        while (sl != r10_bio->read_slot) {
                                                int d;
                                                if (sl==0)
                                                        sl = conf->copies;
                                                sl--;
                                                d = r10_bio->devs[sl].devnum;
-                                               rdev = conf->mirrors[d].rdev;
-                                               atomic_add(s, &rdev->corrected_errors);
+                                               rdev = rcu_dereference(conf->mirrors[d].rdev);
                                                if (rdev &&
                                                    test_bit(In_sync, &rdev->flags)) {
+                                                       atomic_inc(&rdev->nr_pending);
+                                                       rcu_read_unlock();
+                                                       atomic_add(s, &rdev->corrected_errors);
                                                        if (sync_page_io(rdev->bdev,
                                                                         r10_bio->devs[sl].addr +
                                                                         sect + rdev->data_offset,
                                                                         s<<9, conf->tmppage, WRITE) == 0)
                                                                /* Well, this device is dead */
                                                                md_error(mddev, rdev);
+                                                       rdev_dec_pending(rdev, mddev);
+                                                       rcu_read_lock();
                                                }
                                        }
                                        sl = start;
@@ -1454,17 +1464,22 @@ static void raid10d(mddev_t *mddev)
                                                        sl = conf->copies;
                                                sl--;
                                                d = r10_bio->devs[sl].devnum;
-                                               rdev = conf->mirrors[d].rdev;
+                                               rdev = rcu_dereference(conf->mirrors[d].rdev);
                                                if (rdev &&
                                                    test_bit(In_sync, &rdev->flags)) {
+                                                       atomic_inc(&rdev->nr_pending);
+                                                       rcu_read_unlock();
                                                        if (sync_page_io(rdev->bdev,
                                                                         r10_bio->devs[sl].addr +
                                                                         sect + rdev->data_offset,
                                                                         s<<9, conf->tmppage, READ) == 0)
                                                                /* Well, this device is dead */
                                                                md_error(mddev, rdev);
+                                                       rdev_dec_pending(rdev, mddev);
+                                                       rcu_read_lock();
                                                }
                                        }
+                                       rcu_read_unlock();
                                } else {
                                        /* Cannot read from anywhere -- bye bye array */
                                        md_error(mddev, conf->mirrors[r10_bio->devs[r10_bio->read_slot].devnum].rdev);
@@ -1518,8 +1533,7 @@ static int init_resync(conf_t *conf)
        int buffs;
 
        buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
-       if (conf->r10buf_pool)
-               BUG();
+       BUG_ON(conf->r10buf_pool);
        conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
        if (!conf->r10buf_pool)
                return -ENOMEM;