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.

Cc: Jeremy Linton <jlin...@tributary.com>
Cc: Kay Sievers <k...@vrfy.org>
Cc: Doug Gilbert <dgilb...@interlog.com>
Cc: Kai Makisara <kai.makis...@kolumbus.fi>
Signed-off-by: Hannes Reinecke <h...@suse.de>
---
 drivers/scsi/scsi.c        | 79 ++++++++++++++++++++++++++++++++++++++++++----
 drivers/scsi/scsi_scan.c   |  3 ++
 drivers/scsi/scsi_sysfs.c  | 39 ++++++++++++++++++++++-
 include/scsi/scsi.h        |  4 ++-
 include/scsi/scsi_device.h |  3 ++
 5 files changed, 119 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index d8afec8..e4cd88d 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -954,7 +954,7 @@ EXPORT_SYMBOL(scsi_track_queue_full);
  * This is an internal helper function.  You probably want to use
  * scsi_get_vpd_page instead.
  *
- * Returns 0 on success or a negative error number.
+ * Returns size of the vpg page on success or a negative error number.
  */
 static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
                                                        u8 page, unsigned len)
@@ -962,6 +962,9 @@ static int scsi_vpd_inquiry(struct scsi_device *sdev, 
unsigned char *buffer,
        int result;
        unsigned char cmd[16];
 
+       if (len < 4)
+               return -EINVAL;
+
        cmd[0] = INQUIRY;
        cmd[1] = 1;             /* EVPD */
        cmd[2] = page;
@@ -982,7 +985,7 @@ static int scsi_vpd_inquiry(struct scsi_device *sdev, 
unsigned char *buffer,
        if (buffer[1] != page)
                return -EIO;
 
-       return 0;
+       return (buffer[2] << 8) + buffer[3] + 4;
 }
 
 /**
@@ -1009,18 +1012,18 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 
page, unsigned char *buf,
 
        /* Ask for all the pages supported by this device */
        result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
-       if (result)
+       if (result < 4)
                goto fail;
 
        /* If the user actually wanted this page, we can skip the rest */
        if (page == 0)
                return 0;
 
-       for (i = 0; i < min((int)buf[3], buf_len - 4); i++)
-               if (buf[i + 4] == page)
+       for (i = 4; i < min(result, buf_len); i++)
+               if (buf[i] == page)
                        goto found;
 
-       if (i < buf[3] && i >= buf_len - 4)
+       if (i < result && i >= buf_len)
                /* ran off the end of the buffer, give us benefit of doubt */
                goto found;
        /* The device claims it doesn't support the requested page */
@@ -1028,7 +1031,7 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, 
unsigned char *buf,
 
  found:
        result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
-       if (result)
+       if (result < 0)
                goto fail;
 
        return 0;
@@ -1039,6 +1042,68 @@ 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) 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 = 255;
+       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] == 0x83) {
+                       pg83_supported = 1;
+               }
+       }
+       kfree(vpd_buf);
+
+       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)
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 307a811..154bb5e 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -929,6 +929,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned 
char *inq_result,
        if (*bflags & BLIST_SKIP_VPD_PAGES)
                sdev->skip_vpd_pages = 1;
 
+       if (sdev->scsi_level >= SCSI_3)
+               scsi_attach_vpd(sdev);
+
        transport_configure_device(&sdev->sdev_gendev);
 
        if (sdev->host->hostt->slave_configure) {
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 196e59a..ca19448 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -415,6 +415,7 @@ static void scsi_device_dev_release_usercontext(struct 
work_struct *work)
 
        scsi_target_reap(scsi_target(sdev));
 
+       kfree(sdev->vpd_pg83);
        kfree(sdev->inquiry);
        kfree(sdev);
 
@@ -755,7 +756,38 @@ static DEVICE_ATTR(queue_type, S_IRUGO | S_IWUSR, 
show_queue_type_field,
                   store_queue_type_field);
 
 static ssize_t
-show_iostat_counterbits(struct device *dev, struct device_attribute *attr,     
                        char *buf)
+show_vpd_pg(const unsigned char *pg_buf, int pg_len, char *buf)
+{
+       int len = 0, i;
+
+       if (!pg_buf)
+               return -EINVAL;
+
+       len = 0;
+       for (i = 0; i < pg_len; i += 16) {
+               hex_dump_to_buffer(pg_buf + i, pg_len, 16, 1,
+                                  buf + len, PAGE_SIZE, false);
+               strcat(buf + len, "\n");
+               len += strlen(buf + len);
+       }
+       return len;
+}
+
+#define sdev_vpd_pg_attr(page) \
+static ssize_t                                            \
+show_vpd_##page(struct device *dev, struct device_attribute *attr, \
+               char *buf)                                              \
+{                                                                      \
+       struct scsi_device *sdev = to_scsi_device(dev);                 \
+       return show_vpd_pg(sdev->vpd_##page, sdev->vpd_##page##_len, buf); \
+}                                                                      \
+static DEVICE_ATTR(vpd_##page, S_IRUGO, show_vpd_##page, NULL);
+
+sdev_vpd_pg_attr(pg83);
+
+static ssize_t
+show_iostat_counterbits(struct device *dev, struct device_attribute *attr,
+                       char *buf)
 {
        return snprintf(buf, 20, "%d\n", (int)sizeof(atomic_t) * 8);
 }
@@ -905,6 +937,10 @@ static umode_t scsi_sdev_attr_is_visible(struct kobject 
*kobj,
            !sdev->host->hostt->change_queue_type)
                return S_IRUGO;
 
+       if (attr == &dev_attr_vpd_pg83.attr &&
+           !sdev->vpd_pg83)
+               return 0;
+
        return attr->mode;
 }
 
@@ -930,6 +966,7 @@ static struct attribute *scsi_sdev_attrs[] = {
        &dev_attr_queue_depth.attr,
        &dev_attr_queue_type.attr,
        &dev_attr_queue_ramp_up_period.attr,
+       &dev_attr_vpd_pg83.attr,
        REF_EVT(media_change),
        REF_EVT(inquiry_change_reported),
        REF_EVT(capacity_change_reported),
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 0a4edfe..8fd13bb 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -334,7 +334,7 @@ static inline int scsi_status_is_good(int status)
 #define TYPE_OSD            0x11
 #define TYPE_NO_LUN         0x7f
 
-/* SCSI protocols; these are taken from SPC-3 section 7.5 */
+/* SCSI protocols; these are taken from SPC-4 section 7.6 */
 enum scsi_protocol {
        SCSI_PROTOCOL_FCP = 0,  /* Fibre Channel */
        SCSI_PROTOCOL_SPI = 1,  /* parallel SCSI */
@@ -345,6 +345,8 @@ enum scsi_protocol {
        SCSI_PROTOCOL_SAS = 6,
        SCSI_PROTOCOL_ADT = 7,  /* Media Changers */
        SCSI_PROTOCOL_ATA = 8,
+       SCSI_PROTOCOL_UAS = 9,
+       SCSI_PROTOCOL_SOP = 0xa,
        SCSI_PROTOCOL_UNSPEC = 0xf, /* No specific protocol */
 };
 
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index dcb2b73..b99ed35 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -113,6 +113,8 @@ struct scsi_device {
        const char * vendor;            /* [back_compat] point into 'inquiry' 
... */
        const char * model;             /* ... after scan; point to static 
string */
        const char * rev;               /* ... "nullnullnullnull" before scan */
+       unsigned char vpd_pg83_len;
+       unsigned char *vpd_pg83;
        struct scsi_target      *sdev_target;   /* used only for single_lun */
 
        unsigned int    sdev_bflags; /* black/white flags as also found in
@@ -308,6 +310,7 @@ extern int scsi_add_device(struct Scsi_Host *host, uint 
channel,
 extern int scsi_register_device_handler(struct scsi_device_handler *scsi_dh);
 extern void scsi_remove_device(struct scsi_device *);
 extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh);
+void scsi_attach_vpd(struct scsi_device *sdev);
 
 extern int scsi_device_get(struct scsi_device *);
 extern void scsi_device_put(struct scsi_device *);
-- 
1.7.12.4

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