rnbd-srv: Convert to use bdev_open_by_path()

Convert rnbd-srv to use bdev_open_by_path() and pass the handle
around.

CC: Jack Wang <jinpu.wang@ionos.com>
CC: "Md. Haris Iqbal" <haris.iqbal@ionos.com>
Acked-by: "Md. Haris Iqbal" <haris.iqbal@ionos.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230927093442.25915-6-jack@suse.czSigned-off-by: Christian Brauner <brauner@kernel.org>

drivers/block/rnbd/rnbd-srv.c

@@ -145,7 +145,7 @@ static int process_rdma(struct rnbd_srv_session *srv_sess,
 	priv->sess_dev = sess_dev;
 	priv->id = id;
 
-	bio = bio_alloc(sess_dev->bdev, 1,
+	bio = bio_alloc(sess_dev->bdev_handle->bdev, 1,
 			rnbd_to_bio_flags(le32_to_cpu(msg->rw)), GFP_KERNEL);
 	if (bio_add_page(bio, virt_to_page(data), datalen,
 			offset_in_page(data)) != datalen) {
@@ -219,7 +219,7 @@ void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id)
 	rnbd_put_sess_dev(sess_dev);
 	wait_for_completion(&dc); /* wait for inflights to drop to zero */
 
-	blkdev_put(sess_dev->bdev, NULL);
+	bdev_release(sess_dev->bdev_handle);
 	mutex_lock(&sess_dev->dev->lock);
 	list_del(&sess_dev->dev_list);
 	if (!sess_dev->readonly)
@@ -534,7 +534,7 @@ rnbd_srv_get_or_create_srv_dev(struct block_device *bdev,
 static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
 					struct rnbd_srv_sess_dev *sess_dev)
 {
-	struct block_device *bdev = sess_dev->bdev;
+	struct block_device *bdev = sess_dev->bdev_handle->bdev;
 
 	rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP);
 	rsp->device_id = cpu_to_le32(sess_dev->device_id);
@@ -559,7 +559,7 @@ static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
 static struct rnbd_srv_sess_dev *
 rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess,
 			      const struct rnbd_msg_open *open_msg,
-			      struct block_device *bdev, bool readonly,
+			      struct bdev_handle *handle, bool readonly,
 			      struct rnbd_srv_dev *srv_dev)
 {
 	struct rnbd_srv_sess_dev *sdev = rnbd_sess_dev_alloc(srv_sess);
@@ -571,7 +571,7 @@ rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess,
 
 	strscpy(sdev->pathname, open_msg->dev_name, sizeof(sdev->pathname));
 
-	sdev->bdev		= bdev;
+	sdev->bdev_handle	= handle;
 	sdev->sess		= srv_sess;
 	sdev->dev		= srv_dev;
 	sdev->readonly		= readonly;
@@ -676,7 +676,7 @@ static int process_msg_open(struct rnbd_srv_session *srv_sess,
 	struct rnbd_srv_dev *srv_dev;
 	struct rnbd_srv_sess_dev *srv_sess_dev;
 	const struct rnbd_msg_open *open_msg = msg;
-	struct block_device *bdev;
+	struct bdev_handle *bdev_handle;
 	blk_mode_t open_flags = BLK_OPEN_READ;
 	char *full_path;
 	struct rnbd_msg_open_rsp *rsp = data;
@@ -714,15 +714,15 @@ static int process_msg_open(struct rnbd_srv_session *srv_sess,
 		goto reject;
 	}
 
-	bdev = blkdev_get_by_path(full_path, open_flags, NULL, NULL);
-	if (IS_ERR(bdev)) {
-		ret = PTR_ERR(bdev);
+	bdev_handle = bdev_open_by_path(full_path, open_flags, NULL, NULL);
+	if (IS_ERR(bdev_handle)) {
+		ret = PTR_ERR(bdev_handle);
 		pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %d\n",
 		       full_path, srv_sess->sessname, ret);
 		goto free_path;
 	}
 
-	srv_dev = rnbd_srv_get_or_create_srv_dev(bdev, srv_sess,
+	srv_dev = rnbd_srv_get_or_create_srv_dev(bdev_handle->bdev, srv_sess,
 						  open_msg->access_mode);
 	if (IS_ERR(srv_dev)) {
 		pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %ld\n",
@@ -731,7 +731,8 @@ static int process_msg_open(struct rnbd_srv_session *srv_sess,
 		goto blkdev_put;
 	}
 
-	srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg, bdev,
+	srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
+				bdev_handle,
 				open_msg->access_mode == RNBD_ACCESS_RO,
 				srv_dev);
 	if (IS_ERR(srv_sess_dev)) {
@@ -747,7 +748,7 @@ static int process_msg_open(struct rnbd_srv_session *srv_sess,
 	 */
 	mutex_lock(&srv_dev->lock);
 	if (!srv_dev->dev_kobj.state_in_sysfs) {
-		ret = rnbd_srv_create_dev_sysfs(srv_dev, bdev);
+		ret = rnbd_srv_create_dev_sysfs(srv_dev, bdev_handle->bdev);
 		if (ret) {
 			mutex_unlock(&srv_dev->lock);
 			rnbd_srv_err(srv_sess_dev,
@@ -790,7 +791,7 @@ static int process_msg_open(struct rnbd_srv_session *srv_sess,
 	}
 	rnbd_put_srv_dev(srv_dev);
 blkdev_put:
-	blkdev_put(bdev, NULL);
+	bdev_release(bdev_handle);
 free_path:
 	kfree(full_path);
 reject:

drivers/block/rnbd/rnbd-srv.h

@@ -46,7 +46,7 @@ struct rnbd_srv_dev {
 struct rnbd_srv_sess_dev {
 	/* Entry inside rnbd_srv_dev struct */
 	struct list_head		dev_list;
-	struct block_device		*bdev;
+	struct bdev_handle		*bdev_handle;
 	struct rnbd_srv_session		*sess;
 	struct rnbd_srv_dev		*dev;
 	struct kobject                  kobj;