5 files changed, 71 insertions, 13 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index e98db04eb4f9..2bc56e2a3526 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1851,7 +1851,7 @@ EXPORT_SYMBOL_GPL(bitmap_load);
  * to our bitmap
  */
 int bitmap_copy_from_slot(struct mddev *mddev, int slot,
-                sector_t *low, sector_t *high)
+                sector_t *low, sector_t *high, bool clear_bits)
 {
         int rv = 0, i, j;
         sector_t block, lo = 0, hi = 0;
@@ -1882,14 +1882,16 @@ int bitmap_copy_from_slot(struct mddev *mddev, int slot,
                 }
         }
 
-        bitmap_update_sb(bitmap);
-        /* Setting this for the ev_page should be enough.
-         * And we do not require both write_all and PAGE_DIRT either
-         */
-        for (i = 0; i < bitmap->storage.file_pages; i++)
-                set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
-        bitmap_write_all(bitmap);
-        bitmap_unplug(bitmap);
+        if (clear_bits) {
+                bitmap_update_sb(bitmap);
+                /* Setting this for the ev_page should be enough.
+                 * And we do not require both write_all and PAGE_DIRT either
+                 */
+                for (i = 0; i < bitmap->storage.file_pages; i++)
+                        set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
+                bitmap_write_all(bitmap);
+                bitmap_unplug(bitmap);
+        }
         *low = lo;
         *high = hi;
 err:
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index 4aabc74ef7b9..f1f4dd01090d 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -263,7 +263,7 @@ void bitmap_daemon_work(struct mddev *mddev);
 int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
                   int chunksize, int init);
 int bitmap_copy_from_slot(struct mddev *mddev, int slot,
-                                sector_t *lo, sector_t *hi);
+                                sector_t *lo, sector_t *hi, bool clear_bits);
 #endif
 
 #endif
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index 30b41b70db17..fcfc4b9b2672 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -73,6 +73,7 @@ enum msg_type {
         RESYNCING,
         NEWDISK,
         REMOVE,
+        RE_ADD,
 };
 
 struct cluster_msg {
@@ -253,7 +254,7 @@ static void recover_bitmaps(struct md_thread *thread)
                                         str, ret);
                         goto clear_bit;
                 }
-                ret = bitmap_copy_from_slot(mddev, slot, &lo, &hi);
+                ret = bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
                 if (ret) {
                         pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
                         goto dlm_unlock;
@@ -412,6 +413,16 @@ static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
                 pr_warn("%s: %d Could not find disk(%d) to REMOVE\n", __func__, __LINE__, msg->raid_slot);
 }
 
+static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
+{
+        struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev, msg->raid_slot);
+
+        if (rdev && test_bit(Faulty, &rdev->flags))
+                clear_bit(Faulty, &rdev->flags);
+        else
+                pr_warn("%s: %d Could not find disk(%d) which is faulty", __func__, __LINE__, msg->raid_slot);
+}
+
 static void process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
 {
         switch (msg->type) {
@@ -436,6 +447,11 @@ static void process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
                         __func__, __LINE__, msg->slot);
                 process_remove_disk(mddev, msg);
                 break;
+        case RE_ADD:
+                pr_info("%s: %d Received RE_ADD from %d\n",
+                        __func__, __LINE__, msg->slot);
+                process_readd_disk(mddev, msg);
+                break;
         default:
                 pr_warn("%s:%d Received unknown message from %d\n",
                         __func__, __LINE__, msg->slot);
@@ -883,6 +899,35 @@ static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
         return __sendmsg(cinfo, &cmsg);
 }
 
+static int gather_bitmaps(struct md_rdev *rdev)
+{
+        int sn, err;
+        sector_t lo, hi;
+        struct cluster_msg cmsg;
+        struct mddev *mddev = rdev->mddev;
+        struct md_cluster_info *cinfo = mddev->cluster_info;
+
+        cmsg.type = RE_ADD;
+        cmsg.raid_slot = rdev->desc_nr;
+        err = sendmsg(cinfo, &cmsg);
+        if (err)
+                goto out;
+
+        for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
+                if (sn == (cinfo->slot_number - 1))
+                        continue;
+                err = bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
+                if (err) {
+                        pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
+                        goto out;
+                }
+                if ((hi > 0) && (lo < mddev->recovery_cp))
+                        mddev->recovery_cp = lo;
+        }
+out:
+        return err;
+}
+
 static struct md_cluster_operations cluster_ops = {
         .join   = join,
         .leave  = leave,
@@ -898,6 +943,7 @@ static struct md_cluster_operations cluster_ops = {
         .add_new_disk_finish = add_new_disk_finish,
         .new_disk_ack = new_disk_ack,
         .remove_disk = remove_disk,
+        .gather_bitmaps = gather_bitmaps,
 };
 
 static int __init cluster_init(void)
diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h
index 71e51432c1f4..6817ee00e053 100644
--- a/drivers/md/md-cluster.h
+++ b/drivers/md/md-cluster.h
@@ -23,6 +23,7 @@ struct md_cluster_operations {
         int (*add_new_disk_finish)(struct mddev *mddev);
         int (*new_disk_ack)(struct mddev *mddev, bool ack);
         int (*remove_disk)(struct mddev *mddev, struct md_rdev *rdev);
+        int (*gather_bitmaps)(struct md_rdev *rdev);
 };
 
 #endif /* _MD_CLUSTER_H */
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 429e95e9a942..d9cac48db2fc 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2596,8 +2596,17 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
                 }
         } else if (cmd_match(buf, "re-add")) {
                 if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1)) {
-                        clear_bit(Faulty, &rdev->flags);
-                        err = add_bound_rdev(rdev);
+                        /* clear_bit is performed _after_ all the devices
+                         * have their local Faulty bit cleared. If any writes
+                         * happen in the meantime in the local node, they
+                         * will land in the local bitmap, which will be synced
+                         * by this node eventually
+                         */
+                        if (!mddev_is_clustered(rdev->mddev) ||
+                            (err = md_cluster_ops->gather_bitmaps(rdev)) == 0) {
+                                clear_bit(Faulty, &rdev->flags);
+                                err = add_bound_rdev(rdev);
+                        }
                 } else
                         err = -EBUSY;
         }