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* [PATCH] clear garbage after CDBs on SG_IO
@ 2006-11-16  0:52 Tejun Heo
  2006-11-16  1:52 ` Jeff Garzik
  2006-11-16  8:49 ` Andrew Morton
  0 siblings, 2 replies; 4+ messages in thread
From: Tejun Heo @ 2006-11-16  0:52 UTC (permalink / raw)
  To: Andrew Morton, Jens Axboe, dougg; +Cc: mfluhr, alan, jgarzik, linux-ide

ATAPI devices transfer fixed number of bytes for CDBs (12 or 16).
Some ATAPI devices choke when shorter CDB is used and the left bytes
contain garbage.  Block SG_IO cleared left bytes but SCSI SG_IO
didn't.  This patch makes SCSI SG_IO clear it and simplify CDB
clearing in block SG_IO.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Mathieu Fluhr <mfluhr@nero.com>

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 2dc3264..cac7f18 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -286,9 +286,8 @@ static int sg_io(struct file *file, requ
 	 * fill in request structure
 	 */
 	rq->cmd_len = hdr->cmd_len;
+	memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
 	memcpy(rq->cmd, cmd, hdr->cmd_len);
-	if (sizeof(rq->cmd) != hdr->cmd_len)
-		memset(rq->cmd + hdr->cmd_len, 0, sizeof(rq->cmd) - hdr->cmd_len);
 
 	memset(sense, 0, sizeof(sense));
 	rq->sense = sense;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d2c02df..3ac4890 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -410,6 +410,7 @@ int scsi_execute_async(struct scsi_devic
 		goto free_req;
 
 	req->cmd_len = cmd_len;
+	memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
 	memcpy(req->cmd, cmd, req->cmd_len);
 	req->sense = sioc->sense;
 	req->sense_len = 0;

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] clear garbage after CDBs on SG_IO
  2006-11-16  0:52 [PATCH] clear garbage after CDBs on SG_IO Tejun Heo
@ 2006-11-16  1:52 ` Jeff Garzik
  2006-11-16  8:49 ` Andrew Morton
  1 sibling, 0 replies; 4+ messages in thread
From: Jeff Garzik @ 2006-11-16  1:52 UTC (permalink / raw)
  To: Tejun Heo; +Cc: Andrew Morton, Jens Axboe, dougg, mfluhr, alan, linux-ide

Tejun Heo wrote:
> ATAPI devices transfer fixed number of bytes for CDBs (12 or 16).
> Some ATAPI devices choke when shorter CDB is used and the left bytes
> contain garbage.  Block SG_IO cleared left bytes but SCSI SG_IO
> didn't.  This patch makes SCSI SG_IO clear it and simplify CDB
> clearing in block SG_IO.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>
> Cc: Mathieu Fluhr <mfluhr@nero.com>

ACK



^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] clear garbage after CDBs on SG_IO
  2006-11-16  0:52 [PATCH] clear garbage after CDBs on SG_IO Tejun Heo
  2006-11-16  1:52 ` Jeff Garzik
@ 2006-11-16  8:49 ` Andrew Morton
  2006-11-16 11:47   ` Tejun Heo
  1 sibling, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2006-11-16  8:49 UTC (permalink / raw)
  To: Tejun Heo; +Cc: Jens Axboe, dougg, mfluhr, alan, jgarzik, linux-ide

On Thu, 16 Nov 2006 09:52:27 +0900
Tejun Heo <htejun@gmail.com> wrote:

> ATAPI devices transfer fixed number of bytes for CDBs (12 or 16).
> Some ATAPI devices choke when shorter CDB is used and the left bytes
> contain garbage.  Block SG_IO cleared left bytes but SCSI SG_IO
> didn't.  This patch makes SCSI SG_IO clear it and simplify CDB
> clearing in block SG_IO.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>
> Cc: Mathieu Fluhr <mfluhr@nero.com>
> 
> diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
> index 2dc3264..cac7f18 100644
> --- a/block/scsi_ioctl.c
> +++ b/block/scsi_ioctl.c
> @@ -286,9 +286,8 @@ static int sg_io(struct file *file, requ
>  	 * fill in request structure
>  	 */
>  	rq->cmd_len = hdr->cmd_len;
> +	memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */

s/req/rq/ makes the compiler happier there.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] clear garbage after CDBs on SG_IO
  2006-11-16  8:49 ` Andrew Morton
@ 2006-11-16 11:47   ` Tejun Heo
  0 siblings, 0 replies; 4+ messages in thread
From: Tejun Heo @ 2006-11-16 11:47 UTC (permalink / raw)
  To: Andrew Morton; +Cc: Jens Axboe, dougg, mfluhr, alan, jgarzik, linux-ide

Andrew Morton wrote:
> On Thu, 16 Nov 2006 09:52:27 +0900
> Tejun Heo <htejun@gmail.com> wrote:
> 
>> ATAPI devices transfer fixed number of bytes for CDBs (12 or 16).
>> Some ATAPI devices choke when shorter CDB is used and the left bytes
>> contain garbage.  Block SG_IO cleared left bytes but SCSI SG_IO
>> didn't.  This patch makes SCSI SG_IO clear it and simplify CDB
>> clearing in block SG_IO.
>>
>> Signed-off-by: Tejun Heo <htejun@gmail.com>
>> Cc: Mathieu Fluhr <mfluhr@nero.com>
>>
>> diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
>> index 2dc3264..cac7f18 100644
>> --- a/block/scsi_ioctl.c
>> +++ b/block/scsi_ioctl.c
>> @@ -286,9 +286,8 @@ static int sg_io(struct file *file, requ
>>  	 * fill in request structure
>>  	 */
>>  	rq->cmd_len = hdr->cmd_len;
>> +	memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
> 
> s/req/rq/ makes the compiler happier there.

Yeap, apparently.  Sorry.  Last minute copy and paste w/ comment. 
Arggh... No change is ever safe.

-- 
tejun

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2006-11-16 11:47 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2006-11-16  0:52 [PATCH] clear garbage after CDBs on SG_IO Tejun Heo
2006-11-16  1:52 ` Jeff Garzik
2006-11-16  8:49 ` Andrew Morton
2006-11-16 11:47   ` Tejun Heo

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