From: Martin Wilck <mwilck@xxxxxxxx>
The current implementation of scsi_vpd_lun_id() uses the designator
length as an implicit measure of priority. This works most of the
time, but not always. For example, some Hitachi storage arrays return
this in VPD 0x83:
VPD INQUIRY: Device Identification page
Designation descriptor number 1, descriptor length: 24
designator_type: T10 vendor identification, code_set: ASCII
associated with the Addressed logical unit
vendor id: HITACHI
vendor specific: 5030C3502025
Designation descriptor number 2, descriptor length: 6
designator_type: vendor specific [0x0], code_set: Binary
associated with the Target port
vendor specific: 08 03
Designation descriptor number 3, descriptor length: 20
designator_type: NAA, code_set: Binary
associated with the Addressed logical unit
NAA 6, IEEE Company_id: 0x60e8
Vendor Specific Identifier: 0x7c35000
Vendor Specific Identifier Extension: 0x30c35000002025
[0x60060e8007c350000030c35000002025]
The current code would use the first descriptor, because it's longer
than the NAA descriptor. But this is wrong, the kernel is supposed
to prefer NAA descriptors over T10 vendor ID. Designator length
should only be used to compare designators of the same type.
This patch addresses the issue by separating designator priority and
length.
Fixes: 9983bed3907c ("scsi: Add scsi_vpd_lun_id()")
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
drivers/scsi/scsi_lib.c | 126 +++++++++++++++++++++++++++-------------
1 file changed, 86 insertions(+), 40 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 60c7a7d74852..293ee1af62c3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2949,6 +2949,78 @@ void sdev_enable_disk_events(struct scsi_device *sdev)
}
EXPORT_SYMBOL(sdev_enable_disk_events);
+static unsigned char designator_prio(const unsigned char *d)
+{
+ if (d[1] & 0x30)
+ /* not associated with LUN */
+ return 0;
+
+ if (d[3] == 0)
+ /* invalid length */
+ return 0;
+
+ /*
+ * Order of preference for lun descriptor:
+ * - SCSI name string
+ * - NAA IEEE Registered Extended
+ * - EUI-64 based 16-byte
+ * - EUI-64 based 12-byte
+ * - NAA IEEE Registered
+ * - NAA IEEE Extended
+ * - EUI-64 based 8-byte
+ * - SCSI name string (truncated)
+ * - T10 Vendor ID
+ * as longer descriptors reduce the likelyhood
+ * of identification clashes.
+ */
+
+ switch (d[1] & 0xf) {
+ case 8:
+ /* SCSI name string, variable-length UTF-8 */
+ return 9;
+ case 3:
+ switch (d[4] >> 4) {
+ case 6:
+ /* NAA registered extended */
+ return 8;
+ case 5:
+ /* NAA registered */
+ return 5;
+ case 4:
+ /* NAA extended */
+ return 4;
+ case 3:
+ /* NAA locally assigned */
+ return 1;
+ default:
+ break;
+ }
+ break;
+ case 2:
+ switch (d[3]) {
+ case 16:
+ /* EUI64-based, 16 byte */
+ return 7;
+ case 12:
+ /* EUI64-based, 12 byte */
+ return 6;
+ case 8:
+ /* EUI64-based, 8 byte */
+ return 3;
+ default:
+ break;
+ }
+ break;
+ case 1:
+ /* T10 vendor ID */
+ return 1;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
/**
* scsi_vpd_lun_id - return a unique device identification
* @sdev: SCSI device
@@ -2965,7 +3037,7 @@ EXPORT_SYMBOL(sdev_enable_disk_events);
*/
int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
{
- u8 cur_id_type = 0xff;
+ u8 cur_id_prio = 0;
u8 cur_id_size = 0;
const unsigned char *d, *cur_id_str;
const struct scsi_vpd *vpd_pg83;
@@ -2978,20 +3050,6 @@ int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
return -ENXIO;
}
- /*
- * Look for the correct descriptor.
- * Order of preference for lun descriptor:
- * - SCSI name string
- * - NAA IEEE Registered Extended
- * - EUI-64 based 16-byte
- * - EUI-64 based 12-byte
- * - NAA IEEE Registered
- * - NAA IEEE Extended
- * - T10 Vendor ID
- * as longer descriptors reduce the likelyhood
- * of identification clashes.
- */
-
/* The id string must be at least 20 bytes + terminating NULL byte */
if (id_len < 21) {
rcu_read_unlock();
@@ -3001,8 +3059,9 @@ int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
memset(id, 0, id_len);
d = vpd_pg83->data + 4;
while (d < vpd_pg83->data + vpd_pg83->len) {
- /* Skip designators not referring to the LUN */
- if ((d[1] & 0x30) != 0x00)
+ u8 prio = designator_prio(d);
+
+ if (prio == 0 || cur_id_prio > prio)
goto next_desig;
switch (d[1] & 0xf) {
@@ -3010,28 +3069,19 @@ int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
/* T10 Vendor ID */
if (cur_id_size > d[3])
break;
- /* Prefer anything */
- if (cur_id_type > 0x01 && cur_id_type != 0xff)
- break;
+ cur_id_prio = prio;
cur_id_size = d[3];
if (cur_id_size + 4 > id_len)
cur_id_size = id_len - 4;
cur_id_str = d + 4;
- cur_id_type = d[1] & 0xf;
id_size = snprintf(id, id_len, "t10.%*pE",
cur_id_size, cur_id_str);
break;
case 0x2:
/* EUI-64 */
- if (cur_id_size > d[3])
- break;
- /* Prefer NAA IEEE Registered Extended */
- if (cur_id_type == 0x3 &&
- cur_id_size == d[3])
- break;
+ cur_id_prio = prio;
cur_id_size = d[3];
cur_id_str = d + 4;
- cur_id_type = d[1] & 0xf;
switch (cur_id_size) {
case 8:
id_size = snprintf(id, id_len,
@@ -3049,17 +3099,14 @@ int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
cur_id_str);
break;
default:
- cur_id_size = 0;
break;
}
break;
case 0x3:
/* NAA */
- if (cur_id_size > d[3])
- break;
+ cur_id_prio = prio;
cur_id_size = d[3];
cur_id_str = d + 4;
- cur_id_type = d[1] & 0xf;
switch (cur_id_size) {
case 8:
id_size = snprintf(id, id_len,
@@ -3072,26 +3119,25 @@ int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
cur_id_str);
break;
default:
- cur_id_size = 0;
break;
}
break;
case 0x8:
/* SCSI name string */
- if (cur_id_size + 4 > d[3])
+ if (cur_id_size > d[3])
break;
/* Prefer others for truncated descriptor */
- if (cur_id_size && d[3] > id_len)
- break;
+ if (d[3] > id_len) {
+ prio = 2;
+ if (cur_id_prio > prio)
+ break;
+ }
+ cur_id_prio = prio;
cur_id_size = id_size = d[3];
cur_id_str = d + 4;
- cur_id_type = d[1] & 0xf;
if (cur_id_size >= id_len)
cur_id_size = id_len - 1;
memcpy(id, cur_id_str, cur_id_size);
- /* Decrease priority for truncated descriptor */
- if (cur_id_size != id_size)
- cur_id_size = 6;
break;
default:
break;
--
2.29.0
