md/raid10: pull the code that wait for blocked dev into one function
[sfrench/cifs-2.6.git] / drivers / md / raid10.c
index 5fa390880f85f891eff92dad628f8575850a31cc..16ddf41b56ef52c72b0a037aae5f0141672ce3d4 100644 (file)
@@ -1273,12 +1273,77 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
        }
 }
 
+static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
+{
+       int i;
+       struct r10conf *conf = mddev->private;
+       struct md_rdev *blocked_rdev;
+
+retry_wait:
+       blocked_rdev = NULL;
+       rcu_read_lock();
+       for (i = 0; i < conf->copies; i++) {
+               struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+               struct md_rdev *rrdev = rcu_dereference(
+                       conf->mirrors[i].replacement);
+               if (rdev == rrdev)
+                       rrdev = NULL;
+               if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+                       atomic_inc(&rdev->nr_pending);
+                       blocked_rdev = rdev;
+                       break;
+               }
+               if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
+                       atomic_inc(&rrdev->nr_pending);
+                       blocked_rdev = rrdev;
+                       break;
+               }
+
+               if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
+                       sector_t first_bad;
+                       sector_t dev_sector = r10_bio->devs[i].addr;
+                       int bad_sectors;
+                       int is_bad;
+
+                       /*
+                        * Discard request doesn't care the write result
+                        * so it doesn't need to wait blocked disk here.
+                        */
+                       if (!r10_bio->sectors)
+                               continue;
+
+                       is_bad = is_badblock(rdev, dev_sector, r10_bio->sectors,
+                                            &first_bad, &bad_sectors);
+                       if (is_bad < 0) {
+                               /*
+                                * Mustn't write here until the bad block
+                                * is acknowledged
+                                */
+                               atomic_inc(&rdev->nr_pending);
+                               set_bit(BlockedBadBlocks, &rdev->flags);
+                               blocked_rdev = rdev;
+                               break;
+                       }
+               }
+       }
+       rcu_read_unlock();
+
+       if (unlikely(blocked_rdev)) {
+               /* Have to wait for this device to get unblocked, then retry */
+               allow_barrier(conf);
+               raid10_log(conf->mddev, "%s wait rdev %d blocked",
+                               __func__, blocked_rdev->raid_disk);
+               md_wait_for_blocked_rdev(blocked_rdev, mddev);
+               wait_barrier(conf);
+               goto retry_wait;
+       }
+}
+
 static void raid10_write_request(struct mddev *mddev, struct bio *bio,
                                 struct r10bio *r10_bio)
 {
        struct r10conf *conf = mddev->private;
        int i;
-       struct md_rdev *blocked_rdev;
        sector_t sectors;
        int max_sectors;
 
@@ -1336,8 +1401,9 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
 
        r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
        raid10_find_phys(conf, r10_bio);
-retry_write:
-       blocked_rdev = NULL;
+
+       wait_blocked_dev(mddev, r10_bio);
+
        rcu_read_lock();
        max_sectors = r10_bio->sectors;
 
@@ -1348,16 +1414,6 @@ retry_write:
                        conf->mirrors[d].replacement);
                if (rdev == rrdev)
                        rrdev = NULL;
-               if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
-                       atomic_inc(&rdev->nr_pending);
-                       blocked_rdev = rdev;
-                       break;
-               }
-               if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
-                       atomic_inc(&rrdev->nr_pending);
-                       blocked_rdev = rrdev;
-                       break;
-               }
                if (rdev && (test_bit(Faulty, &rdev->flags)))
                        rdev = NULL;
                if (rrdev && (test_bit(Faulty, &rrdev->flags)))
@@ -1378,15 +1434,6 @@ retry_write:
 
                        is_bad = is_badblock(rdev, dev_sector, max_sectors,
                                             &first_bad, &bad_sectors);
-                       if (is_bad < 0) {
-                               /* Mustn't write here until the bad block
-                                * is acknowledged
-                                */
-                               atomic_inc(&rdev->nr_pending);
-                               set_bit(BlockedBadBlocks, &rdev->flags);
-                               blocked_rdev = rdev;
-                               break;
-                       }
                        if (is_bad && first_bad <= dev_sector) {
                                /* Cannot write here at all */
                                bad_sectors -= (dev_sector - first_bad);
@@ -1422,35 +1469,6 @@ retry_write:
        }
        rcu_read_unlock();
 
-       if (unlikely(blocked_rdev)) {
-               /* Have to wait for this device to get unblocked, then retry */
-               int j;
-               int d;
-
-               for (j = 0; j < i; j++) {
-                       if (r10_bio->devs[j].bio) {
-                               d = r10_bio->devs[j].devnum;
-                               rdev_dec_pending(conf->mirrors[d].rdev, mddev);
-                       }
-                       if (r10_bio->devs[j].repl_bio) {
-                               struct md_rdev *rdev;
-                               d = r10_bio->devs[j].devnum;
-                               rdev = conf->mirrors[d].replacement;
-                               if (!rdev) {
-                                       /* Race with remove_disk */
-                                       smp_mb();
-                                       rdev = conf->mirrors[d].rdev;
-                               }
-                               rdev_dec_pending(rdev, mddev);
-                       }
-               }
-               allow_barrier(conf);
-               raid10_log(conf->mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
-               md_wait_for_blocked_rdev(blocked_rdev, mddev);
-               wait_barrier(conf);
-               goto retry_write;
-       }
-
        if (max_sectors < r10_bio->sectors)
                r10_bio->sectors = max_sectors;