[SCSI] Add EVPD page 0x83 and 0x80 to sysfs

EVPD page 0x83 is used to uniquely identify the device.
So instead of having each and every program issue a separate
SG_IO call to retrieve this information it does make far more
sense to display it in sysfs.

Some older devices (most notably tapes) will only report reliable
information in page 0x80 (Unit Serial Number). So export this
in the sysfs attribute 'vpd_pg80'.

[jejb: checkpatch fix]
[hare: attach after transport configure]
[fengguang.wu@intel.com: spotted problems with the original now fixed]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index b2526ad7b9a1..1d98ac960887 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -1030,6 +1030,93 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
 EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
 
 /**
+ * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
+ * @sdev: The device to ask
+ *
+ * Attach the 'Device Identification' VPD page (0x83) and the
+ * 'Unit Serial Number' VPD page (0x80) to a SCSI device
+ * structure. This information can be used to identify the device
+ * uniquely.
+ */
+void scsi_attach_vpd(struct scsi_device *sdev)
+{
+        int result, i;
+        int vpd_len = SCSI_VPD_PG_LEN;
+        int pg80_supported = 0;
+        int pg83_supported = 0;
+        unsigned char *vpd_buf;
+
+        if (sdev->skip_vpd_pages)
+                return;
+retry_pg0:
+        vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
+        if (!vpd_buf)
+                return;
+
+        /* Ask for all the pages supported by this device */
+        result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
+        if (result < 0) {
+                kfree(vpd_buf);
+                return;
+        }
+        if (result > vpd_len) {
+                vpd_len = result;
+                kfree(vpd_buf);
+                goto retry_pg0;
+        }
+
+        for (i = 4; i < result; i++) {
+                if (vpd_buf[i] == 0x80)
+                        pg80_supported = 1;
+                if (vpd_buf[i] == 0x83)
+                        pg83_supported = 1;
+        }
+        kfree(vpd_buf);
+        vpd_len = SCSI_VPD_PG_LEN;
+
+        if (pg80_supported) {
+retry_pg80:
+                vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
+                if (!vpd_buf)
+                        return;
+
+                result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
+                if (result < 0) {
+                        kfree(vpd_buf);
+                        return;
+                }
+                if (result > vpd_len) {
+                        vpd_len = result;
+                        kfree(vpd_buf);
+                        goto retry_pg80;
+                }
+                sdev->vpd_pg80_len = result;
+                sdev->vpd_pg80 = vpd_buf;
+                vpd_len = SCSI_VPD_PG_LEN;
+        }
+
+        if (pg83_supported) {
+retry_pg83:
+                vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
+                if (!vpd_buf)
+                        return;
+
+                result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
+                if (result < 0) {
+                        kfree(vpd_buf);
+                        return;
+                }
+                if (result > vpd_len) {
+                        vpd_len = result;
+                        kfree(vpd_buf);
+                        goto retry_pg83;
+                }
+                sdev->vpd_pg83_len = result;
+                sdev->vpd_pg83 = vpd_buf;
+        }
+}
+
+/**
  * scsi_report_opcode - Find out if a given command opcode is supported
  * @sdev:       scsi device to query
  * @buffer:     scratch buffer (must be at least 20 bytes long)