| Message ID | 20201023122113.35517-1-colin.king@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | vsock: ratelimit unknown ioctl error message | expand |
On Fri, Oct 23, 2020 at 01:21:13PM +0100, Colin King wrote: >From: Colin Ian King <colin.king@canonical.com> > >When exercising the kernel with stress-ng with some ioctl tests the >"Unknown ioctl" error message is spamming the kernel log at a high >rate. Rate limit this message to reduce the noise. > >Signed-off-by: Colin Ian King <colin.king@canonical.com> >--- > net/vmw_vsock/af_vsock.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >index 9e93bc201cc0..b8feb9223454 100644 >--- a/net/vmw_vsock/af_vsock.c >+++ b/net/vmw_vsock/af_vsock.c >@@ -2072,7 +2072,7 @@ static long vsock_dev_do_ioctl(struct file *filp, > break; > > default: >- pr_err("Unknown ioctl %d\n", cmd); >+ pr_err_ratelimited("Unknown ioctl %d\n", cmd); Make sense, or maybe can we remove the error message returning only the -EINVAL? Both cases are fine for me: Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> > retval = -EINVAL; > } > >-- >2.27.0 >
On Fri, 23 Oct 2020 16:09:47 +0200 Stefano Garzarella wrote: > On Fri, Oct 23, 2020 at 01:21:13PM +0100, Colin King wrote: > >From: Colin Ian King <colin.king@canonical.com> > > > >When exercising the kernel with stress-ng with some ioctl tests the > >"Unknown ioctl" error message is spamming the kernel log at a high > >rate. Rate limit this message to reduce the noise. > > > >Signed-off-by: Colin Ian King <colin.king@canonical.com> > >--- > > net/vmw_vsock/af_vsock.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c > >index 9e93bc201cc0..b8feb9223454 100644 > >--- a/net/vmw_vsock/af_vsock.c > >+++ b/net/vmw_vsock/af_vsock.c > >@@ -2072,7 +2072,7 @@ static long vsock_dev_do_ioctl(struct file *filp, > > break; > > > > default: > >- pr_err("Unknown ioctl %d\n", cmd); > >+ pr_err_ratelimited("Unknown ioctl %d\n", cmd); > > Make sense, or maybe can we remove the error message returning only the > -EINVAL? +1 > Both cases are fine for me: > Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
From: Stefano Garzarella > Sent: 23 October 2020 15:10 > > On Fri, Oct 23, 2020 at 01:21:13PM +0100, Colin King wrote: > >From: Colin Ian King <colin.king@canonical.com> > > > >When exercising the kernel with stress-ng with some ioctl tests the > >"Unknown ioctl" error message is spamming the kernel log at a high > >rate. Rate limit this message to reduce the noise. > > > >Signed-off-by: Colin Ian King <colin.king@canonical.com> > >--- > > net/vmw_vsock/af_vsock.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c > >index 9e93bc201cc0..b8feb9223454 100644 > >--- a/net/vmw_vsock/af_vsock.c > >+++ b/net/vmw_vsock/af_vsock.c > >@@ -2072,7 +2072,7 @@ static long vsock_dev_do_ioctl(struct file *filp, > > break; > > > > default: > >- pr_err("Unknown ioctl %d\n", cmd); > >+ pr_err_ratelimited("Unknown ioctl %d\n", cmd); > > Make sense, or maybe can we remove the error message returning only the > -EINVAL? Isn't the canonical error for unknown ioctl codes -ENOTTY? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On Fri, Oct 23, 2020 at 09:30:59PM +0000, David Laight wrote: > >From: Stefano Garzarella >> Sent: 23 October 2020 15:10 >> >> On Fri, Oct 23, 2020 at 01:21:13PM +0100, Colin King wrote: >> >From: Colin Ian King <colin.king@canonical.com> >> > >> >When exercising the kernel with stress-ng with some ioctl tests the >> >"Unknown ioctl" error message is spamming the kernel log at a high >> >rate. Rate limit this message to reduce the noise. >> > >> >Signed-off-by: Colin Ian King <colin.king@canonical.com> >> >--- >> > net/vmw_vsock/af_vsock.c | 2 +- >> > 1 file changed, 1 insertion(+), 1 deletion(-) >> > >> >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >> >index 9e93bc201cc0..b8feb9223454 100644 >> >--- a/net/vmw_vsock/af_vsock.c >> >+++ b/net/vmw_vsock/af_vsock.c >> >@@ -2072,7 +2072,7 @@ static long vsock_dev_do_ioctl(struct file *filp, >> > break; >> > >> > default: >> >- pr_err("Unknown ioctl %d\n", cmd); >> >+ pr_err_ratelimited("Unknown ioctl %d\n", cmd); >> >> Make sense, or maybe can we remove the error message returning only the >> -EINVAL? > >Isn't the canonical error for unknown ioctl codes -ENOTTY? > Oh, thanks for pointing that out! I had not paid attention to the error returned, but looking at it I noticed that perhaps the most appropriate would be -ENOIOCTLCMD. In the ioctl syscall we return -ENOTTY, if the callback returns -ENOIOCTLCMD. What do you think? Stefano
From: Stefano Garzarella > Sent: 26 October 2020 08:43 ... > >Isn't the canonical error for unknown ioctl codes -ENOTTY? > > > > Oh, thanks for pointing that out! > > I had not paid attention to the error returned, but looking at it I > noticed that perhaps the most appropriate would be -ENOIOCTLCMD. > In the ioctl syscall we return -ENOTTY, if the callback returns > -ENOIOCTLCMD. > > What do you think? It is 729 v 443 in favour of ENOTTY (based on grep). No idea where ENOIOCTLCMD comes from, but ENOTTY probably goes back to the early 1970s. The fact that the ioctl wrapper converts the value is a good hint that userspace expects ENOTTY. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On Mon, Oct 26, 2020 at 09:13:23AM +0000, David Laight wrote: >From: Stefano Garzarella >> Sent: 26 October 2020 08:43 >... >> >Isn't the canonical error for unknown ioctl codes -ENOTTY? >> > >> >> Oh, thanks for pointing that out! >> >> I had not paid attention to the error returned, but looking at it I >> noticed that perhaps the most appropriate would be -ENOIOCTLCMD. >> In the ioctl syscall we return -ENOTTY, if the callback returns >> -ENOIOCTLCMD. >> >> What do you think? > >It is 729 v 443 in favour of ENOTTY (based on grep). Under net/ it is 6 vs 83 in favour of ENOIOCTLCMD. > >No idea where ENOIOCTLCMD comes from, but ENOTTY probably >goes back to the early 1970s. Me too. > >The fact that the ioctl wrapper converts the value is a good >hint that userspace expects ENOTTY. Agree on that, but since we are not interfacing directly with userspace, I think it is better to return the more specific error (ENOIOCTLCMD). Thanks, Stefano
From: Stefano Garzarella > Sent: 26 October 2020 09:39 > > On Mon, Oct 26, 2020 at 09:13:23AM +0000, David Laight wrote: > >From: Stefano Garzarella > >> Sent: 26 October 2020 08:43 > >... > >> >Isn't the canonical error for unknown ioctl codes -ENOTTY? > >> > > >> > >> Oh, thanks for pointing that out! > >> > >> I had not paid attention to the error returned, but looking at it I > >> noticed that perhaps the most appropriate would be -ENOIOCTLCMD. > >> In the ioctl syscall we return -ENOTTY, if the callback returns > >> -ENOIOCTLCMD. > >> > >> What do you think? > > > >It is 729 v 443 in favour of ENOTTY (based on grep). > > Under net/ it is 6 vs 83 in favour of ENOIOCTLCMD. > > > > >No idea where ENOIOCTLCMD comes from, but ENOTTY probably > >goes back to the early 1970s. > > Me too. > > > > >The fact that the ioctl wrapper converts the value is a good > >hint that userspace expects ENOTTY. > > Agree on that, but since we are not interfacing directly with userspace, > I think it is better to return the more specific error (ENOIOCTLCMD). I bet Linux thought it could use a different error code then found that 'unknown ioctl' was spelt ENOTTY. Back in the old days error values were probably almost unique. strerror(EAGIAN) was "No more processes" for a long time! David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On Mon, Oct 26, 2020 at 09:46:17AM +0000, David Laight wrote: >From: Stefano Garzarella >> Sent: 26 October 2020 09:39 >> >> On Mon, Oct 26, 2020 at 09:13:23AM +0000, David Laight wrote: >> >From: Stefano Garzarella >> >> Sent: 26 October 2020 08:43 >> >... >> >> >Isn't the canonical error for unknown ioctl codes -ENOTTY? >> >> > >> >> >> >> Oh, thanks for pointing that out! >> >> >> >> I had not paid attention to the error returned, but looking at it I >> >> noticed that perhaps the most appropriate would be -ENOIOCTLCMD. >> >> In the ioctl syscall we return -ENOTTY, if the callback returns >> >> -ENOIOCTLCMD. >> >> >> >> What do you think? >> > >> >It is 729 v 443 in favour of ENOTTY (based on grep). >> >> Under net/ it is 6 vs 83 in favour of ENOIOCTLCMD. >> >> > >> >No idea where ENOIOCTLCMD comes from, but ENOTTY probably >> >goes back to the early 1970s. >> >> Me too. >> >> > >> >The fact that the ioctl wrapper converts the value is a good >> >hint that userspace expects ENOTTY. >> >> Agree on that, but since we are not interfacing directly with userspace, >> I think it is better to return the more specific error (ENOIOCTLCMD). > >I bet Linux thought it could use a different error code then >found that 'unknown ioctl' was spelt ENOTTY. It could be :-) Anyway, as you pointed out, I think we should change the -EINVAL with -ENOTTY or -ENOIOCTLCMD. @Jakub what do you suggest? Thanks, Stefano
On Mon, 26 Oct 2020 11:01:12 +0100 Stefano Garzarella wrote: > On Mon, Oct 26, 2020 at 09:46:17AM +0000, David Laight wrote: > >From: Stefano Garzarella > >> Sent: 26 October 2020 09:39 > >> > >> On Mon, Oct 26, 2020 at 09:13:23AM +0000, David Laight wrote: > >> >From: Stefano Garzarella > >> >> Sent: 26 October 2020 08:43 > >> >... > >> >> >Isn't the canonical error for unknown ioctl codes -ENOTTY? > >> >> > > >> >> > >> >> Oh, thanks for pointing that out! > >> >> > >> >> I had not paid attention to the error returned, but looking at it I > >> >> noticed that perhaps the most appropriate would be -ENOIOCTLCMD. > >> >> In the ioctl syscall we return -ENOTTY, if the callback returns > >> >> -ENOIOCTLCMD. > >> >> > >> >> What do you think? > >> > > >> >It is 729 v 443 in favour of ENOTTY (based on grep). > >> > >> Under net/ it is 6 vs 83 in favour of ENOIOCTLCMD. > >> > >> > > >> >No idea where ENOIOCTLCMD comes from, but ENOTTY probably > >> >goes back to the early 1970s. > >> > >> Me too. > >> > >> > > >> >The fact that the ioctl wrapper converts the value is a good > >> >hint that userspace expects ENOTTY. > >> > >> Agree on that, but since we are not interfacing directly with userspace, > >> I think it is better to return the more specific error (ENOIOCTLCMD). > > > >I bet Linux thought it could use a different error code then > >found that 'unknown ioctl' was spelt ENOTTY. > > It could be :-) > > Anyway, as you pointed out, I think we should change the -EINVAL with > -ENOTTY or -ENOIOCTLCMD. > > @Jakub what do you suggest? ENOIOCTLCMD is a kernel-internal high return code (515) which should be returned by the driver, but it's then caught inside the core and translated to ENOTTY which is then returned to user space. So you're both right, I guess? But the driver should use ENOIOCTLCMD.
On Mon, Oct 26, 2020 at 10:55:48AM -0700, Jakub Kicinski wrote: >On Mon, 26 Oct 2020 11:01:12 +0100 Stefano Garzarella wrote: >> On Mon, Oct 26, 2020 at 09:46:17AM +0000, David Laight wrote: >> >From: Stefano Garzarella >> >> Sent: 26 October 2020 09:39 >> >> >> >> On Mon, Oct 26, 2020 at 09:13:23AM +0000, David Laight wrote: >> >> >From: Stefano Garzarella >> >> >> Sent: 26 October 2020 08:43 >> >> >... >> >> >> >Isn't the canonical error for unknown ioctl codes -ENOTTY? >> >> >> > >> >> >> >> >> >> Oh, thanks for pointing that out! >> >> >> >> >> >> I had not paid attention to the error returned, but looking at it I >> >> >> noticed that perhaps the most appropriate would be -ENOIOCTLCMD. >> >> >> In the ioctl syscall we return -ENOTTY, if the callback returns >> >> >> -ENOIOCTLCMD. >> >> >> >> >> >> What do you think? >> >> > >> >> >It is 729 v 443 in favour of ENOTTY (based on grep). >> >> >> >> Under net/ it is 6 vs 83 in favour of ENOIOCTLCMD. >> >> >> >> > >> >> >No idea where ENOIOCTLCMD comes from, but ENOTTY probably >> >> >goes back to the early 1970s. >> >> >> >> Me too. >> >> >> >> > >> >> >The fact that the ioctl wrapper converts the value is a good >> >> >hint that userspace expects ENOTTY. >> >> >> >> Agree on that, but since we are not interfacing directly with userspace, >> >> I think it is better to return the more specific error (ENOIOCTLCMD). >> > >> >I bet Linux thought it could use a different error code then >> >found that 'unknown ioctl' was spelt ENOTTY. >> >> It could be :-) >> >> Anyway, as you pointed out, I think we should change the -EINVAL with >> -ENOTTY or -ENOIOCTLCMD. >> >> @Jakub what do you suggest? > >ENOIOCTLCMD is a kernel-internal high return code (515) which should >be returned by the driver, but it's then caught inside the core and >translated to ENOTTY which is then returned to user space. > >So you're both right, I guess? But the driver should use ENOIOCTLCMD. > Thanks for clarify! @Colin, can you send a v2 removing the error message and updating the return value? Thanks, Stefano
On Mon, 26 Oct 2020 19:24:57 +0100 Stefano Garzarella wrote: > @Colin, can you send a v2 removing the error message and updating the > return value? Not as a single patch, please, these are two different changes.
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 9e93bc201cc0..b8feb9223454 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -2072,7 +2072,7 @@ static long vsock_dev_do_ioctl(struct file *filp, break; default: - pr_err("Unknown ioctl %d\n", cmd); + pr_err_ratelimited("Unknown ioctl %d\n", cmd); retval = -EINVAL; }