This patch (as1507) adds a skip_vpd_pages flag to struct scsi_device
and a no_report_luns flag to struct scsi_target. The first is used to
control whether sd will look at VPD pages for information on block
provisioning, limits, and characteristics. The second prevents
scsi_report_lun_scan() from issuing a REPORT LUNS command.
The patch also modifies usb-storage to set the new flag bits for all
USB devices and targets, and to stop adjusting the scsi_level value.
Historically we have seen that USB mass-storage devices often don't
support VPD pages or REPORT LUNS properly. Until now we have avoided
these things by setting the scsi_level to SCSI_2 for all USB devices.
But this has the side effect of storing the LUN bits into the second
byte of each CDB, and now we have a report of a device which doesn't
like that. The best solution is to stop abusing scsi_level and
instead have separate flags for VPD pages and REPORT LUNS.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Perry Wagle <wagle@xxxxxxx>
CC: Matthew Dharm <mdharm-usb@xxxxxxxxxxxxxxxxxx>
---
drivers/scsi/scsi_scan.c | 4 ++++
drivers/scsi/sd.c | 2 +-
drivers/usb/storage/scsiglue.c | 26 ++++++++++++++++----------
include/scsi/scsi_device.h | 3 +++
4 files changed, 24 insertions(+), 11 deletions(-)
Index: usb-3.2/include/scsi/scsi_device.h
===================================================================
--- usb-3.2.orig/include/scsi/scsi_device.h
+++ usb-3.2/include/scsi/scsi_device.h
@@ -136,6 +136,7 @@ struct scsi_device {
unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
unsigned skip_ms_page_8:1; /* do not use MODE SENSE page 0x08 */
unsigned skip_ms_page_3f:1; /* do not use MODE SENSE page 0x3f */
+ unsigned skip_vpd_pages:1; /* do not read VPD pages */
unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
unsigned no_start_on_add:1; /* do not issue start on add */
unsigned allow_restart:1; /* issue START_UNIT in error handler */
@@ -249,6 +250,8 @@ struct scsi_target {
* for the device at a time. */
unsigned int pdt_1f_for_no_lun:1; /* PDT = 0x1f
* means no lun present. */
+ unsigned int no_report_luns:1; /* Don't use
+ * REPORT LUNS for scanning. */
/* commands actually active on LLD. protected by host lock. */
unsigned int target_busy;
/*
Index: usb-3.2/drivers/scsi/scsi_scan.c
===================================================================
--- usb-3.2.orig/drivers/scsi/scsi_scan.c
+++ usb-3.2/drivers/scsi/scsi_scan.c
@@ -1295,6 +1295,7 @@ EXPORT_SYMBOL(int_to_scsilun);
* LUNs even if it's older than SCSI-3.
* If BLIST_NOREPORTLUN is set, return 1 always.
* If BLIST_NOLUN is set, return 0 always.
+ * If starget->no_report_luns is set, return 1 always.
*
* Return:
* 0: scan completed (or no memory, so further scanning is futile)
@@ -1321,6 +1322,7 @@ static int scsi_report_lun_scan(struct s
* Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
* Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
* support more than 8 LUNs.
+ * Don't attempt if the target doesn't support REPORT LUNS.
*/
if (bflags & BLIST_NOREPORTLUN)
return 1;
@@ -1332,6 +1334,8 @@ static int scsi_report_lun_scan(struct s
return 1;
if (bflags & BLIST_NOLUN)
return 0;
+ if (starget->no_report_luns)
+ return 1;
if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
sdev = scsi_alloc_sdev(starget, 0, NULL);
Index: usb-3.2/drivers/scsi/sd.c
===================================================================
--- usb-3.2.orig/drivers/scsi/sd.c
+++ usb-3.2/drivers/scsi/sd.c
@@ -2341,7 +2341,7 @@ static int sd_try_extended_inquiry(struc
* some USB ones crash on receiving them, and the pages
* we currently ask for are for SPC-3 and beyond
*/
- if (sdp->scsi_level > SCSI_SPC_2)
+ if (sdp->scsi_level > SCSI_SPC_2 && !sdp->skip_vpd_pages)
return 1;
return 0;
}
Index: usb-3.2/drivers/usb/storage/scsiglue.c
===================================================================
--- usb-3.2.orig/drivers/usb/storage/scsiglue.c
+++ usb-3.2/drivers/usb/storage/scsiglue.c
@@ -197,6 +197,9 @@ static int slave_configure(struct scsi_d
* page x08, so we will skip it. */
sdev->skip_ms_page_8 = 1;
+ /* Some devices don't handle VPD pages correctly */
+ sdev->skip_vpd_pages = 1;
+
/* Some disks return the total number of blocks in response
* to READ CAPACITY rather than the highest block number.
* If this device makes that mistake, tell the sd driver. */
@@ -217,16 +220,6 @@ static int slave_configure(struct scsi_d
if (sdev->scsi_level > SCSI_SPC_2)
us->fflags |= US_FL_SANE_SENSE;
- /* Some devices report a SCSI revision level above 2 but are
- * unable to handle the REPORT LUNS command (for which
- * support is mandatory at level 3). Since we already have
- * a Get-Max-LUN request, we won't lose much by setting the
- * revision level down to 2. The only devices that would be
- * affected are those with sparse LUNs. */
- if (sdev->scsi_level > SCSI_2)
- sdev->sdev_target->scsi_level =
- sdev->scsi_level = SCSI_2;
-
/* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
* Hardware Error) when any low-level error occurs,
* recoverable or not. Setting this flag tells the SCSI
@@ -283,6 +276,18 @@ static int slave_configure(struct scsi_d
return 0;
}
+static int target_alloc(struct scsi_target *starget)
+{
+ /*
+ * Some USB drives don't support REPORT LUNS, even though they
+ * report a SCSI revision level above 2. Tell the SCSI layer
+ * not to issue that command; it will perform a normal sequential
+ * scan instead.
+ */
+ starget->no_report_luns = 1;
+ return 0;
+}
+
/* queue a command */
/* This is always called with scsi_lock(host) held */
static int queuecommand_lck(struct scsi_cmnd *srb,
@@ -546,6 +551,7 @@ struct scsi_host_template usb_stor_host_
.slave_alloc = slave_alloc,
.slave_configure = slave_configure,
+ .target_alloc = target_alloc,
/* lots of sg segments can be handled */
.sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS,
--
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