>>>>> "Alan" == Alan Stern <st...@rowland.harvard.edu> writes:

Alan,

Alan> It was introduced by commit 98dcc2946adb (SCSI: sd: Update WRITE
Alan> SAME heuristics).  This commit adds a call to scsi_get_vpd_page()
Alan> in sd_read_write_same() without first checking
Alan> sd_try_extended_inquiry().  As noted in the latter routine, VPD
Alan> inquiries will crash some devices.

Is REPORT SUPPORTED OPERATION CODES generally safe on USB devices?

The reason I didn't wrap the WRITE SAME heuristics in
sd_try_extended_inquiry() like I have done with most of the other VPDs
is that there are a ton of older SPI/SAS/FC devices that support WRITE
SAME just fine.


Alan> As far as the stable kernels are concerned, the best thing for now
Alan> may simply be to revert it.

No go. The above commit fixes issues for somebody else.

I could add an explicit check to the sd_read_write_same() function. But
how about we do the following instead?

-- 
Martin K. Petersen      Oracle Linux Engineering


SCSI: Don't attempt to send extended INQUIRY command if skip_vpd_pages is set

If a device has the skip_vpd_pages flag set we should simply fail the
scsi_get_vpd_page() call.

Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
Cc: Alan Stern <st...@rowland.harvard.edu>
Cc: sta...@vger.kernel.org
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 3b1ea34..eaa808e 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -1031,6 +1031,9 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, 
unsigned char *buf,
 {
        int i, result;
 
+       if (sdev->skip_vpd_pages)
+               goto fail;
+
        /* Ask for all the pages supported by this device */
        result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
        if (result)
--
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