[PATCH] scsi_logging: print cdb into new line after opcode

[PATCH] scsi_logging: print cdb into new line after opcode

[Martin Kepplinger]

The current log message results in a line like the following where
the first byte is duplicated, giving a wrong impression:

sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28 28 00 00 00 60 40 00 00 01 00

Print the cdb into a new line in any case, not only when cmd_len is
greater than 16. The above example error will then read:

sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28
28 00 01 c0 09 00 00 00 08 00

Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
---
 drivers/scsi/scsi_logging.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/scsi_logging.c b/drivers/scsi/scsi_logging.c
index 8ea44c6595ef..0081d3936f83 100644
--- a/drivers/scsi/scsi_logging.c
+++ b/drivers/scsi/scsi_logging.c
@@ -200,10 +200,11 @@ void scsi_print_command(struct scsi_cmnd *cmd)
 	if (off >= logbuf_len)
 		goto out_printk;
 
+	/* Print opcode in one line and use separate lines for CDB */
+	off += scnprintf(logbuf + off, logbuf_len - off, "\n");
+
 	/* print out all bytes in cdb */
 	if (cmd->cmd_len > 16) {
-		/* Print opcode in one line and use separate lines for CDB */
-		off += scnprintf(logbuf + off, logbuf_len - off, "\n");
 		dev_printk(KERN_INFO, &cmd->device->sdev_gendev, "%s", logbuf);
 		for (k = 0; k < cmd->cmd_len; k += 16) {
 			size_t linelen = min(cmd->cmd_len - k, 16);
@@ -224,7 +225,6 @@ void scsi_print_command(struct scsi_cmnd *cmd)
 		goto out;
 	}
 	if (!WARN_ON(off > logbuf_len - 49)) {
-		off += scnprintf(logbuf + off, logbuf_len - off, " ");
 		hex_dump_to_buffer(cmd->cmnd, cmd->cmd_len, 16, 1,
 				   logbuf + off, logbuf_len - off,
 				   false);
-- 
2.20.1

Re: [PATCH] scsi_logging: print cdb into new line after opcode

[Ewan D. Milne]

On Fri, 2021-01-22 at 09:39 +0100, Martin Kepplinger wrote:
> The current log message results in a line like the following where
> the first byte is duplicated, giving a wrong impression:
> 
> sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28 28 00 00 00 60 40 00 00 01
> 00
> 
> Print the cdb into a new line in any case, not only when cmd_len is
> greater than 16. The above example error will then read:
> 
> sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28
> 28 00 01 c0 09 00 00 00 08 00
> 
> Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
> ---
>  drivers/scsi/scsi_logging.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_logging.c
> b/drivers/scsi/scsi_logging.c
> index 8ea44c6595ef..0081d3936f83 100644
> --- a/drivers/scsi/scsi_logging.c
> +++ b/drivers/scsi/scsi_logging.c
> @@ -200,10 +200,11 @@ void scsi_print_command(struct scsi_cmnd *cmd)
>  	if (off >= logbuf_len)
>  		goto out_printk;
>  
> +	/* Print opcode in one line and use separate lines for CDB */
> +	off += scnprintf(logbuf + off, logbuf_len - off, "\n");
> +
>  	/* print out all bytes in cdb */
>  	if (cmd->cmd_len > 16) {
> -		/* Print opcode in one line and use separate lines for
> CDB */
> -		off += scnprintf(logbuf + off, logbuf_len - off, "\n");
>  		dev_printk(KERN_INFO, &cmd->device->sdev_gendev, "%s",
> logbuf);
>  		for (k = 0; k < cmd->cmd_len; k += 16) {
>  			size_t linelen = min(cmd->cmd_len - k, 16);
> @@ -224,7 +225,6 @@ void scsi_print_command(struct scsi_cmnd *cmd)
>  		goto out;
>  	}
>  	if (!WARN_ON(off > logbuf_len - 49)) {
> -		off += scnprintf(logbuf + off, logbuf_len - off, " ");
>  		hex_dump_to_buffer(cmd->cmnd, cmd->cmd_len, 16, 1,
>  				   logbuf + off, logbuf_len - off,
>  				   false);

I'd rather we not change this.

-Ewan

Re: [PATCH] scsi_logging: print cdb into new line after opcode

[Martin K. Petersen]

Ewan,

>> sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28 28 00 00 00 60 40 00 00 01
>> 00
>> 
>> Print the cdb into a new line in any case, not only when cmd_len is
>> greater than 16. The above example error will then read:
>> 
>> sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28
>> 28 00 01 c0 09 00 00 00 08 00
>
> I'd rather we not change this.

I agree. While the current format is suboptimal, there are lots of
things out there parsing these error messages.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi_logging: print cdb into new line after opcode

[Martin Kepplinger]

On 23.01.21 04:09, Martin K. Petersen wrote:
> 
> Ewan,
> 
>>> sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28 28 00 00 00 60 40 00 00 01
>>> 00
>>>
>>> Print the cdb into a new line in any case, not only when cmd_len is
>>> greater than 16. The above example error will then read:
>>>
>>> sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28
>>> 28 00 01 c0 09 00 00 00 08 00
>>
>> I'd rather we not change this.
> 
> I agree. While the current format is suboptimal, there are lots of
> things out there parsing these error messages.
> 

hi Ewan, hi Martin,

That's totally fine. I had this on my list since Douglas suggested to 
change this during a discussion back in july and I basically wanted to 
get opinions:
https://lore.kernel.org/linux-scsi/31f1ec62-7047-a34b-fdcb-5ea2a2104292@interlog.com/

thanks,
                                  martin