[patch 1/1] scsi: Disable short inquiry log by default

[patch 1/1] scsi: Disable short inquiry log by default

[brking]

If a scsi device reports less than 36 bytes of standard inquiry
data, scsi core logs a KERN_INFO printk indicating this. It was
observed that this results in lots of clutter in the log on
systems with devices that respond to a SCSI Inquiry with PQ=3 or
PQ=1 with less than 36 bytes of inquiry data, such as ibmvscsi.
Disable this log by default.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
---

 drivers/scsi/scsi_scan.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN drivers/scsi/scsi_scan.c~scsi_scan_short_inq_log drivers/scsi/scsi_scan.c
--- linux-2.6/drivers/scsi/scsi_scan.c~scsi_scan_short_inq_log	2007-04-02 15:10:46.000000000 -0500
+++ linux-2.6-bjking1/drivers/scsi/scsi_scan.c	2007-04-02 15:13:39.000000000 -0500
@@ -662,8 +662,8 @@ static int scsi_probe_lun(struct scsi_de
 	 * strings.
 	 */
 	if (sdev->inquiry_len < 36) {
-		printk(KERN_INFO "scsi scan: INQUIRY result too short (%d),"
-				" using 36\n", sdev->inquiry_len);
+		SCSI_LOG_SCAN_BUS(1, printk(KERN_INFO "scsi scan: INQUIRY result too"
+					    " short (%d), using 36\n", sdev->inquiry_len));
 		sdev->inquiry_len = 36;
 	}
 
_

Re: [patch 1/1] scsi: Disable short inquiry log by default

[Matthew Wilcox]

On Mon, Apr 02, 2007 at 04:20:22PM -0500, brking@linux.vnet.ibm.com wrote:
>  	if (sdev->inquiry_len < 36) {
> -		printk(KERN_INFO "scsi scan: INQUIRY result too short (%d),"
> -				" using 36\n", sdev->inquiry_len);
> +		SCSI_LOG_SCAN_BUS(1, printk(KERN_INFO "scsi scan: INQUIRY result too"
> +					    " short (%d), using 36\n", sdev->inquiry_len));
>  		sdev->inquiry_len = 36;

The wrapping's a bit awkward.  How about:
+		SCSI_LOG_SCAN_BUS(1, printk(KERN_INFO "scsi scan: INQUIRY "
+					"result too short (%d), using 36\n",
+					sdev->inquiry_len);

Re: [patch 1/1] scsi: Disable short inquiry log by default

[James Bottomley]

On Mon, 2007-04-02 at 16:20 -0500, brking@linux.vnet.ibm.com wrote:
> If a scsi device reports less than 36 bytes of standard inquiry
> data, scsi core logs a KERN_INFO printk indicating this. It was
> observed that this results in lots of clutter in the log on
> systems with devices that respond to a SCSI Inquiry with PQ=3 or
> PQ=1 with less than 36 bytes of inquiry data, such as ibmvscsi.
> Disable this log by default.

It shouldn't be doing this ... the standards are pretty clear, say SPC-3
section 6.4.2

"The standard INQUIRY data shall contain at least 36 bytes"

Horrible things happen when this rule is violated (as it is by some
badly constructed devices), so I'd really like to leave the print in so
we know what we're debugging.

Can't you fix ibmvscsi to be standards compliant?

James

Re: [patch 1/1] scsi: Disable short inquiry log by default

[Brian King]

James Bottomley wrote:
> On Mon, 2007-04-02 at 16:20 -0500, brking@linux.vnet.ibm.com wrote:
>> If a scsi device reports less than 36 bytes of standard inquiry
>> data, scsi core logs a KERN_INFO printk indicating this. It was
>> observed that this results in lots of clutter in the log on
>> systems with devices that respond to a SCSI Inquiry with PQ=3 or
>> PQ=1 with less than 36 bytes of inquiry data, such as ibmvscsi.
>> Disable this log by default.
> 
> It shouldn't be doing this ... the standards are pretty clear, say SPC-3
> section 6.4.2
> 
> "The standard INQUIRY data shall contain at least 36 bytes"
> 
> Horrible things happen when this rule is violated (as it is by some
> badly constructed devices), so I'd really like to leave the print in so
> we know what we're debugging.
> 
> Can't you fix ibmvscsi to be standards compliant?

James,

You can drop this patch. I've verified that the current ibmvscsi server
does not do this. I wasn't using the latest ibmvscsi server implementation.

Brian

-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center