3 files changed, 43 insertions, 12 deletions

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 478aa86fc1f2..a94ee45440b3 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -385,17 +385,16 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
 	struct nbd_device *nbd = cmd->nbd;
 	struct nbd_config *config;
 
+	if (!mutex_trylock(&cmd->lock))
+		return BLK_EH_RESET_TIMER;
+
 	if (!refcount_inc_not_zero(&nbd->config_refs)) {
 		cmd->status = BLK_STS_TIMEOUT;
+		mutex_unlock(&cmd->lock);
 		goto done;
 	}
 	config = nbd->config;
 
-	if (!mutex_trylock(&cmd->lock)) {
-		nbd_config_put(nbd);
-		return BLK_EH_RESET_TIMER;
-	}
-
 	if (config->num_connections > 1) {
 		dev_err_ratelimited(nbd_to_dev(nbd),
 				    "Connection timed out, retrying (%d/%d alive)\n",
@@ -711,6 +710,12 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
 		ret = -ENOENT;
 		goto out;
 	}
+	if (cmd->status != BLK_STS_OK) {
+		dev_err(disk_to_dev(nbd->disk), "Command already handled %p\n",
+			req);
+		ret = -ENOENT;
+		goto out;
+	}
 	if (test_bit(NBD_CMD_REQUEUED, &cmd->flags)) {
 		dev_err(disk_to_dev(nbd->disk), "Raced with timeout on req %p\n",
 			req);
@@ -792,7 +797,10 @@ static bool nbd_clear_req(struct request *req, void *data, bool reserved)
 {
 	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
 
+	mutex_lock(&cmd->lock);
 	cmd->status = BLK_STS_IOERR;
+	mutex_unlock(&cmd->lock);
+
 	blk_mq_complete_request(req);
 	return true;
 }
@@ -972,6 +980,25 @@ static blk_status_t nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
 	return ret;
 }
 
+static struct socket *nbd_get_socket(struct nbd_device *nbd, unsigned long fd,
+				     int *err)
+{
+	struct socket *sock;
+
+	*err = 0;
+	sock = sockfd_lookup(fd, err);
+	if (!sock)
+		return NULL;
+
+	if (sock->ops->shutdown == sock_no_shutdown) {
+		dev_err(disk_to_dev(nbd->disk), "Unsupported socket: shutdown callout must be supported.\n");
+		*err = -EINVAL;
+		return NULL;
+	}
+
+	return sock;
+}
+
 static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
 			  bool netlink)
 {
@@ -981,7 +1008,7 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
 	struct nbd_sock *nsock;
 	int err;
 
-	sock = sockfd_lookup(arg, &err);
+	sock = nbd_get_socket(nbd, arg, &err);
 	if (!sock)
 		return err;
 
@@ -1033,7 +1060,7 @@ static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg)
 	int i;
 	int err;
 
-	sock = sockfd_lookup(arg, &err);
+	sock = nbd_get_socket(nbd, arg, &err);
 	if (!sock)
 		return err;
 
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 7c4350c0fb77..39136675dae5 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -6639,10 +6639,13 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
 	queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
 	ret = wait_for_completion_killable_timeout(&rbd_dev->acquire_wait,
 			    ceph_timeout_jiffies(rbd_dev->opts->lock_timeout));
-	if (ret > 0)
+	if (ret > 0) {
 		ret = rbd_dev->acquire_err;
-	else if (!ret)
-		ret = -ETIMEDOUT;
+	} else {
+		cancel_delayed_work_sync(&rbd_dev->lock_dwork);
+		if (!ret)
+			ret = -ETIMEDOUT;
+	}
 
 	if (ret) {
 		rbd_warn(rbd_dev, "failed to acquire exclusive lock: %ld", ret);
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index d58a359a6622..4285e75e52c3 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -413,13 +413,14 @@ static void reset_bdev(struct zram *zram)
 static ssize_t backing_dev_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
+	struct file *file;
 	struct zram *zram = dev_to_zram(dev);
-	struct file *file = zram->backing_dev;
 	char *p;
 	ssize_t ret;
 
 	down_read(&zram->init_lock);
-	if (!zram->backing_dev) {
+	file = zram->backing_dev;
+	if (!file) {
 		memcpy(buf, "none\n", 5);
 		up_read(&zram->init_lock);
 		return 5;