scsi: core: Put .shost_dev in failure path if host state changes to RUNNING

scsi_host_dev_release() only frees dev_name when host state is
SHOST_CREATED. After host state has changed to SHOST_RUNNING,
scsi_host_dev_release() no longer cleans up.

Fix this by doing a put_device(&shost->shost_dev) in the failure path when
host state is SHOST_RUNNING. Move get_device(&shost->shost_gendev) before
device_add(&shost->shost_dev) so that scsi_host_cls_release() can do a put
on this reference.

Link: https://lore.kernel.org/r/[email protected]
Cc: Bart Van Assche <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Reported-by: John Garry <[email protected]>
Tested-by: John Garry <[email protected]>
Reviewed-by: John Garry <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: Ming Lei

drivers/scsi/hosts.c

@@ -254,12 +254,11 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
 
 	device_enable_async_suspend(&shost->shost_dev);
 
+	get_device(&shost->shost_gendev);
 	error = device_add(&shost->shost_dev);
 	if (error)
 		goto out_del_gendev;
 
-	get_device(&shost->shost_gendev);
-
 	if (shost->transportt->host_size) {
 		shost->shost_data = kzalloc(shost->transportt->host_size,
 					 GFP_KERNEL);
@@ -297,6 +296,11 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
  out_del_dev:
 	device_del(&shost->shost_dev);
  out_del_gendev:
+	/*
+	 * Host state is SHOST_RUNNING so we have to explicitly release
+	 * ->shost_dev.
+	 */
+	put_device(&shost->shost_dev);
 	device_del(&shost->shost_gendev);
  out_disable_runtime_pm:
 	device_disable_async_suspend(&shost->shost_gendev);