scsi: Export SCSI Inquiry data to sysfs

Export the RAW SCSI Inquiry to sysfs as binfile. This way the data can be used
by userland without the need to have and ioctl or use the sg_inq tool.

Here is an example of the provided data

linux:~ # hexdump /sys/class/scsi_device/1\:0\:0\:0/device/inquiry
0000000 8005 3205 001f 0000 4551 554d 2020 2020
0000010 4551 554d 4420 4456 522d 4d4f 2020 2020
0000020 2e32 2e33
0000024
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_sysfs.c

@@ -773,6 +773,29 @@ static struct bin_attribute dev_attr_vpd_##_page = {		\
 sdev_vpd_pg_attr(pg83);
 sdev_vpd_pg_attr(pg80);
 
+static ssize_t show_inquiry(struct file *filep, struct kobject *kobj,
+			    struct bin_attribute *bin_attr,
+			    char *buf, loff_t off, size_t count)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct scsi_device *sdev = to_scsi_device(dev);
+
+	if (!sdev->inquiry)
+		return -EINVAL;
+
+	return memory_read_from_buffer(buf, count, &off, sdev->inquiry,
+				       sdev->inquiry_len);
+}
+
+static struct bin_attribute dev_attr_inquiry = {
+	.attr = {
+		.name = "inquiry",
+		.mode = S_IRUGO,
+	},
+	.size = 0,
+	.read = show_inquiry,
+};
+
 static ssize_t
 show_iostat_counterbits(struct device *dev, struct device_attribute *attr,
 			char *buf)
@@ -957,6 +980,7 @@ static struct attribute *scsi_sdev_attrs[] = {
 static struct bin_attribute *scsi_sdev_bin_attrs[] = {
 	&dev_attr_vpd_pg83,
 	&dev_attr_vpd_pg80,
+	&dev_attr_inquiry,
 	NULL
 };
 static struct attribute_group scsi_sdev_attr_group = {