When I use cdparanoia my logs get spammed a lot by
printk: 464 messages suppressed.
sg_write: data in/out 30576/30576 bytes for SCSI command 0xbe--guessing data in;
program cdparanoia not setting count and/or reply_len properly
printk: 1078 messages suppressed.
and many more of those. With this patch the message is only printed once
for a command in a row.
Signed-off-by: Andi Kleen <[email protected]>
---
drivers/scsi/sg.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
Index: linux/drivers/scsi/sg.c
===================================================================
--- linux.orig/drivers/scsi/sg.c
+++ linux/drivers/scsi/sg.c
@@ -602,8 +602,9 @@ sg_write(struct file *filp, const char _
* but is is possible that the app intended SG_DXFER_TO_DEV, because there
* is a non-zero input_size, so emit a warning.
*/
- if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
- if (printk_ratelimit())
+ if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
+ static char cmd[TASK_COMM_LEN];
+ if (printk_ratelimit() && strcmp(current->comm, cmd)) {
printk(KERN_WARNING
"sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
"guessing data in;\n" KERN_WARNING " "
@@ -611,6 +612,9 @@ sg_write(struct file *filp, const char _
old_hdr.reply_len - (int)SZ_SG_HEADER,
input_size, (unsigned int) cmnd[0],
current->comm);
+ strcpy(cmd, current->comm);
+ }
+ }
k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
return (k < 0) ? k : count;
}
On Wed, 2008-01-02 at 07:03 +0100, Andi Kleen wrote:
> When I use cdparanoia my logs get spammed a lot by
>
> printk: 464 messages suppressed.
> sg_write: data in/out 30576/30576 bytes for SCSI command 0xbe--guessing data in;
> program cdparanoia not setting count and/or reply_len properly
> printk: 1078 messages suppressed.
>
> and many more of those. With this patch the message is only printed once
> for a command in a row.
My reaction is that the intent of these warnings is to try to get people
to fix broken applications, so I'm not sure any action is appropriate;
however, it's Doug's driver, so I'll defer to him.
Even if he does say yes, though, your patch looks wrong. It's still
going to spew the
printk: 1078 messages suppressed.
to the log because they come from printk_ratelimit(). So all you've
done is halved the volume of flow to the logs and left a dangling printk
suppressed message that keeps spewing, so I don't think the patch even
does what you describe it as doing ... if you reverse the order of the
operands in the if() it will ...
James
> to the log because they come from printk_ratelimit(). So all you've
> done is halved the volume of flow to the logs and left a dangling printk
> suppressed message that keeps spewing, so I don't think the patch even
> does what you describe it as doing ... if you reverse the order of the
> operands in the if() it will ...
Here's an updated patch with the reversed order.
-Andi
---
Only print SCSI data direction warning once for a command v2
When I use cdparanoia my logs get spammed a lot by
printk: 464 messages suppressed.
sg_write: data in/out 30576/30576 bytes for SCSI command 0xbe--guessing data in;
program cdparanoia not setting count and/or reply_len properly
printk: 1078 messages suppressed.
and many more of those. With this patch the message is only printed once
for a command in a row.
v1->v2: Prevent rate limit messages too (pointed out by jejb)
Signed-off-by: Andi Kleen <[email protected]>
---
drivers/scsi/sg.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
Index: linux/drivers/scsi/sg.c
===================================================================
--- linux.orig/drivers/scsi/sg.c
+++ linux/drivers/scsi/sg.c
@@ -602,8 +602,9 @@ sg_write(struct file *filp, const char _
* but is is possible that the app intended SG_DXFER_TO_DEV, because there
* is a non-zero input_size, so emit a warning.
*/
- if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
- if (printk_ratelimit())
+ if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
+ static char cmd[TASK_COMM_LEN];
+ if (strcmp(current->comm, cmd) && printk_ratelimit()) {
printk(KERN_WARNING
"sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
"guessing data in;\n" KERN_WARNING " "
@@ -611,6 +612,9 @@ sg_write(struct file *filp, const char _
old_hdr.reply_len - (int)SZ_SG_HEADER,
input_size, (unsigned int) cmnd[0],
current->comm);
+ strcpy(cmd, current->comm);
+ }
+ }
k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
return (k < 0) ? k : count;
}
Andi Kleen wrote:
>> to the log because they come from printk_ratelimit(). So all you've
>> done is halved the volume of flow to the logs and left a dangling printk
>> suppressed message that keeps spewing, so I don't think the patch even
>> does what you describe it as doing ... if you reverse the order of the
>> operands in the if() it will ...
>
> Here's an updated patch with the reversed order.
>
> -Andi
>
> ---
>
> Only print SCSI data direction warning once for a command v2
>
> When I use cdparanoia my logs get spammed a lot by
>
> printk: 464 messages suppressed.
> sg_write: data in/out 30576/30576 bytes for SCSI command 0xbe--guessing data in;
> program cdparanoia not setting count and/or reply_len properly
> printk: 1078 messages suppressed.
>
> and many more of those. With this patch the message is only printed once
> for a command in a row.
>
> v1->v2: Prevent rate limit messages too (pointed out by jejb)
>
> Signed-off-by: Andi Kleen <[email protected]>
>
> ---
> drivers/scsi/sg.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> Index: linux/drivers/scsi/sg.c
> ===================================================================
> --- linux.orig/drivers/scsi/sg.c
> +++ linux/drivers/scsi/sg.c
> @@ -602,8 +602,9 @@ sg_write(struct file *filp, const char _
> * but is is possible that the app intended SG_DXFER_TO_DEV, because there
> * is a non-zero input_size, so emit a warning.
> */
> - if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
> - if (printk_ratelimit())
> + if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
> + static char cmd[TASK_COMM_LEN];
> + if (strcmp(current->comm, cmd) && printk_ratelimit()) {
> printk(KERN_WARNING
> "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
> "guessing data in;\n" KERN_WARNING " "
> @@ -611,6 +612,9 @@ sg_write(struct file *filp, const char _
> old_hdr.reply_len - (int)SZ_SG_HEADER,
> input_size, (unsigned int) cmnd[0],
> current->comm);
> + strcpy(cmd, current->comm);
> + }
> + }
> k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
> return (k < 0) ? k : count;
> }
>
>
Signed-off-by: Douglas Gilbert <[email protected]>