3 files changed, 72 insertions, 0 deletions

diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index b58374daff32..db9375f501ab 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -55,6 +55,7 @@ struct md_cluster_info {
         int slot_number;
         struct completion completion;
         struct dlm_lock_resource *bitmap_lockres;
+        struct dlm_lock_resource **other_bitmap_lockres;
         struct dlm_lock_resource *resync_lockres;
         struct list_head suspend_list;
         spinlock_t suspend_lock;
@@ -803,6 +804,7 @@ static void resync_bitmap(struct mddev *mddev)
                         __func__, __LINE__, err);
 }
 
+static void unlock_all_bitmaps(struct mddev *mddev);
 static int leave(struct mddev *mddev)
 {
         struct md_cluster_info *cinfo = mddev->cluster_info;
@@ -823,6 +825,7 @@ static int leave(struct mddev *mddev)
         lockres_free(cinfo->ack_lockres);
         lockres_free(cinfo->no_new_dev_lockres);
         lockres_free(cinfo->bitmap_lockres);
+        unlock_all_bitmaps(mddev);
         dlm_release_lockspace(cinfo->lockspace, 2);
         return 0;
 }
@@ -1000,6 +1003,58 @@ static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
         return sendmsg(cinfo, &cmsg);
 }
 
+static int lock_all_bitmaps(struct mddev *mddev)
+{
+        int slot, my_slot, ret, held = 1, i = 0;
+        char str[64];
+        struct md_cluster_info *cinfo = mddev->cluster_info;
+
+        cinfo->other_bitmap_lockres = kzalloc((mddev->bitmap_info.nodes - 1) *
+                                             sizeof(struct dlm_lock_resource *),
+                                             GFP_KERNEL);
+        if (!cinfo->other_bitmap_lockres) {
+                pr_err("md: can't alloc mem for other bitmap locks\n");
+                return 0;
+        }
+
+        my_slot = slot_number(mddev);
+        for (slot = 0; slot < mddev->bitmap_info.nodes; slot++) {
+                if (slot == my_slot)
+                        continue;
+
+                memset(str, '\0', 64);
+                snprintf(str, 64, "bitmap%04d", slot);
+                cinfo->other_bitmap_lockres[i] = lockres_init(mddev, str, NULL, 1);
+                if (!cinfo->other_bitmap_lockres[i])
+                        return -ENOMEM;
+
+                cinfo->other_bitmap_lockres[i]->flags |= DLM_LKF_NOQUEUE;
+                ret = dlm_lock_sync(cinfo->other_bitmap_lockres[i], DLM_LOCK_PW);
+                if (ret)
+                        held = -1;
+                i++;
+        }
+
+        return held;
+}
+
+static void unlock_all_bitmaps(struct mddev *mddev)
+{
+        struct md_cluster_info *cinfo = mddev->cluster_info;
+        int i;
+
+        /* release other node's bitmap lock if they are existed */
+        if (cinfo->other_bitmap_lockres) {
+                for (i = 0; i < mddev->bitmap_info.nodes - 1; i++) {
+                        if (cinfo->other_bitmap_lockres[i]) {
+                                dlm_unlock_sync(cinfo->other_bitmap_lockres[i]);
+                                lockres_free(cinfo->other_bitmap_lockres[i]);
+                        }
+                }
+                kfree(cinfo->other_bitmap_lockres);
+        }
+}
+
 static int gather_bitmaps(struct md_rdev *rdev)
 {
         int sn, err;
@@ -1045,6 +1100,8 @@ static struct md_cluster_operations cluster_ops = {
         .new_disk_ack = new_disk_ack,
         .remove_disk = remove_disk,
         .gather_bitmaps = gather_bitmaps,
+        .lock_all_bitmaps = lock_all_bitmaps,
+        .unlock_all_bitmaps = unlock_all_bitmaps,
 };
 
 static int __init cluster_init(void)
diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h
index e75ea2613184..45ce6c97d8bd 100644
--- a/drivers/md/md-cluster.h
+++ b/drivers/md/md-cluster.h
@@ -24,6 +24,8 @@ struct md_cluster_operations {
         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);
+        int (*lock_all_bitmaps)(struct mddev *mddev);
+        void (*unlock_all_bitmaps)(struct mddev *mddev);
 };
 
 #endif /* _MD_CLUSTER_H */
diff --git a/drivers/md/md.c b/drivers/md/md.c
index f2f855c203e5..495d8aa0a0d2 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6599,6 +6599,19 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
                                 rv = -EINVAL;
                                 goto err;
                         }
+                        if (mddev->bitmap_info.nodes) {
+                                /* hold PW on all the bitmap lock */
+                                if (md_cluster_ops->lock_all_bitmaps(mddev) <= 0) {
+                                        printk("md: can't change bitmap to none since the"
+                                               " array is in use by more than one node\n");
+                                        rv = -EPERM;
+                                        md_cluster_ops->unlock_all_bitmaps(mddev);
+                                        goto err;
+                                }
+
+                                mddev->bitmap_info.nodes = 0;
+                                md_cluster_ops->leave(mddev);
+                        }
                         mddev->pers->quiesce(mddev, 1);
                         bitmap_destroy(mddev);
                         mddev->pers->quiesce(mddev, 0);