Don't let a blocked_rdev interfere with read request in raid5/6

[linux-2.6] / drivers / md / raid5.c

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 17e0953c3c06b1d004cc608d8cfd4621f886b76e..224de022e7c5d6574cf46747947b3c9e326c8632 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2568,10 +2568,10 @@ static bool handle_stripe5(struct stripe_head *sh)
                if (dev->written)
                        s.written++;
                rdev = rcu_dereference(conf->disks[i].rdev);
-               if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+               if (blocked_rdev == NULL &&
+                   rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
                        blocked_rdev = rdev;
                        atomic_inc(&rdev->nr_pending);
-                       break;
                }
                if (!rdev || !test_bit(In_sync, &rdev->flags)) {
                        /* The ReadError flag will just be confusing now */
@@ -2588,8 +2588,14 @@ static bool handle_stripe5(struct stripe_head *sh)
        rcu_read_unlock();
 
        if (unlikely(blocked_rdev)) {
-               set_bit(STRIPE_HANDLE, &sh->state);
-               goto unlock;
+               if (s.syncing || s.expanding || s.expanded ||
+                   s.to_write || s.written) {
+                       set_bit(STRIPE_HANDLE, &sh->state);
+                       goto unlock;
+               }
+               /* There is nothing for the blocked_rdev to block */
+               rdev_dec_pending(blocked_rdev, conf->mddev);
+               blocked_rdev = NULL;
        }
 
        if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
@@ -2832,10 +2838,10 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
                if (dev->written)
                        s.written++;
                rdev = rcu_dereference(conf->disks[i].rdev);
-               if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+               if (blocked_rdev == NULL &&
+                   rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
                        blocked_rdev = rdev;
                        atomic_inc(&rdev->nr_pending);
-                       break;
                }
                if (!rdev || !test_bit(In_sync, &rdev->flags)) {
                        /* The ReadError flag will just be confusing now */
@@ -2853,9 +2859,16 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
        rcu_read_unlock();
 
        if (unlikely(blocked_rdev)) {
-               set_bit(STRIPE_HANDLE, &sh->state);
-               goto unlock;
+               if (s.syncing || s.expanding || s.expanded ||
+                   s.to_write || s.written) {
+                       set_bit(STRIPE_HANDLE, &sh->state);
+                       goto unlock;
+               }
+               /* There is nothing for the blocked_rdev to block */
+               rdev_dec_pending(blocked_rdev, conf->mddev);
+               blocked_rdev = NULL;
        }
+
        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,