1 files changed, 41 insertions, 5 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 62ebb1bc72be..5bd1e9ec899d 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -538,7 +538,8 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
         }
 
 
-        current_distance = abs(this_sector - conf->mirrors[disk].head_position);
+        current_distance = abs(r10_bio->devs[slot].addr -
+                               conf->mirrors[disk].head_position);
 
         /* Find the disk whose head is closest */
 
@@ -668,6 +669,11 @@ static int make_request(request_queue_t *q, struct bio * bio)
         int i;
         int chunk_sects = conf->chunk_mask + 1;
 
+        if (unlikely(bio_barrier(bio))) {
+                bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
+                return 0;
+        }
+
         /* If this request crosses a chunk boundary, we need to
          * split it.  This will only happen for 1 PAGE (or less) requests.
          */
@@ -900,6 +906,27 @@ static void close_sync(conf_t *conf)
         conf->r10buf_pool = NULL;
 }
 
+/* check if there are enough drives for
+ * every block to appear on atleast one
+ */
+static int enough(conf_t *conf)
+{
+        int first = 0;
+
+        do {
+                int n = conf->copies;
+                int cnt = 0;
+                while (n--) {
+                        if (conf->mirrors[first].rdev)
+                                cnt++;
+                        first = (first+1) % conf->raid_disks;
+                }
+                if (cnt == 0)
+                        return 0;
+        } while (first != 0);
+        return 1;
+}
+
 static int raid10_spare_active(mddev_t *mddev)
 {
         int i;
@@ -938,6 +965,8 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
                  * very different from resync
                  */
                 return 0;
+        if (!enough(conf))
+                return 0;
 
         for (mirror=0; mirror < mddev->raid_disks; mirror++)
                 if ( !(p=conf->mirrors+mirror)->rdev) {
@@ -1445,7 +1474,13 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                                         }
                                 }
                                 if (j == conf->copies) {
-                                        BUG();
+                                        /* Cannot recover, so abort the recovery */
+                                        put_buf(r10_bio);
+                                        r10_bio = rb2;
+                                        if (!test_and_set_bit(MD_RECOVERY_ERR, &mddev->recovery))
+                                                printk(KERN_INFO "raid10: %s: insufficient working devices for recovery.\n",
+                                                       mdname(mddev));
+                                        break;
                                 }
                         }
                 if (biolist == NULL) {
@@ -1678,9 +1713,10 @@ static int run(mddev_t *mddev)
         init_waitqueue_head(&conf->wait_idle);
         init_waitqueue_head(&conf->wait_resume);
 
-        if (!conf->working_disks) {
-                printk(KERN_ERR "raid10: no operational mirrors for %s\n",
-                        mdname(mddev));
+        /* need to check that every block has at least one working mirror */
+        if (!enough(conf)) {
+                printk(KERN_ERR "raid10: not enough operational mirrors for %s\n",
+                       mdname(mddev));
                 goto out_free_conf;
         }