1 files changed, 34 insertions, 8 deletions

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 3b7083b8ecbb..74a05561b620 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -76,6 +76,7 @@ struct link_dead_args {
 #define NBD_HAS_CONFIG_REF              4
 #define NBD_BOUND                       5
 #define NBD_DESTROY_ON_DISCONNECT       6
+#define NBD_DISCONNECT_ON_CLOSE         7
 
 struct nbd_config {
         u32 flags;
@@ -138,6 +139,7 @@ static void nbd_config_put(struct nbd_device *nbd);
 static void nbd_connect_reply(struct genl_info *info, int index);
 static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info);
 static void nbd_dead_link_work(struct work_struct *work);
+static void nbd_disconnect_and_put(struct nbd_device *nbd);
 
 static inline struct device *nbd_to_dev(struct nbd_device *nbd)
 {
@@ -1305,6 +1307,12 @@ out:
 static void nbd_release(struct gendisk *disk, fmode_t mode)
 {
         struct nbd_device *nbd = disk->private_data;
+        struct block_device *bdev = bdget_disk(disk, 0);
+
+        if (test_bit(NBD_DISCONNECT_ON_CLOSE, &nbd->config->runtime_flags) &&
+                        bdev->bd_openers == 0)
+                nbd_disconnect_and_put(nbd);
+
         nbd_config_put(nbd);
         nbd_put(nbd);
 }
@@ -1705,6 +1713,10 @@ again:
                                 &config->runtime_flags);
                         put_dev = true;
                 }
+                if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
+                        set_bit(NBD_DISCONNECT_ON_CLOSE,
+                                &config->runtime_flags);
+                }
         }
 
         if (info->attrs[NBD_ATTR_SOCKETS]) {
@@ -1749,6 +1761,17 @@ out:
         return ret;
 }
 
+static void nbd_disconnect_and_put(struct nbd_device *nbd)
+{
+        mutex_lock(&nbd->config_lock);
+        nbd_disconnect(nbd);
+        nbd_clear_sock(nbd);
+        mutex_unlock(&nbd->config_lock);
+        if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
+                               &nbd->config->runtime_flags))
+                nbd_config_put(nbd);
+}
+
 static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
 {
         struct nbd_device *nbd;
@@ -1781,13 +1804,7 @@ static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
                 nbd_put(nbd);
                 return 0;
         }
-        mutex_lock(&nbd->config_lock);
-        nbd_disconnect(nbd);
-        nbd_clear_sock(nbd);
-        mutex_unlock(&nbd->config_lock);
-        if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
-                               &nbd->config->runtime_flags))
-                nbd_config_put(nbd);
+        nbd_disconnect_and_put(nbd);
         nbd_config_put(nbd);
         nbd_put(nbd);
         return 0;
@@ -1798,7 +1815,7 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
         struct nbd_device *nbd = NULL;
         struct nbd_config *config;
         int index;
-        int ret = -EINVAL;
+        int ret = 0;
         bool put_dev = false;
 
         if (!netlink_capable(skb, CAP_SYS_ADMIN))
@@ -1838,6 +1855,7 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
             !nbd->task_recv) {
                 dev_err(nbd_to_dev(nbd),
                         "not configured, cannot reconfigure\n");
+                ret = -EINVAL;
                 goto out;
         }
 
@@ -1862,6 +1880,14 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
                                                &config->runtime_flags))
                                 refcount_inc(&nbd->refs);
                 }
+
+                if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
+                        set_bit(NBD_DISCONNECT_ON_CLOSE,
+                                        &config->runtime_flags);
+                } else {
+                        clear_bit(NBD_DISCONNECT_ON_CLOSE,
+                                        &config->runtime_flags);
+                }
         }
 
         if (info->attrs[NBD_ATTR_SOCKETS]) {