The virtnet_send_command_reply() function returns true on success or
false on failure. The "ok" variable is true/false depending on whether
it succeeds or not. It's up to the caller to translate the true/false
into -EINVAL on failure or zero for success.
The bug is that __virtnet_get_hw_stats() returns false for both
errors and success. It's not a bug, but it is confusing that the caller
virtnet_get_hw_stats() uses an "ok" variable to store negative error
codes.
Fix the bug and clean things up so that it's clear that
__virtnet_get_hw_stats() returns zero on success or negative error codes
on failure.
Fixes: 941168f8b40e ("virtio_net: support device stats")
Signed-off-by: Dan Carpenter <[email protected]>
---
drivers/net/virtio_net.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 218a446c4c27..4fc0fcdad259 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -4016,7 +4016,7 @@ static int __virtnet_get_hw_stats(struct virtnet_info *vi,
&sgs_out, &sgs_in);
if (!ok)
- return ok;
+ return -EINVAL;
for (p = reply; p - reply < res_size; p += le16_to_cpu(hdr->size)) {
hdr = p;
@@ -4053,7 +4053,7 @@ static int virtnet_get_hw_stats(struct virtnet_info *vi,
struct virtio_net_ctrl_queue_stats *req;
bool enable_cvq;
void *reply;
- int ok;
+ int err;
if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_DEVICE_STATS))
return 0;
@@ -4100,12 +4100,12 @@ static int virtnet_get_hw_stats(struct virtnet_info *vi,
if (enable_cvq)
virtnet_make_stat_req(vi, ctx, req, vi->max_queue_pairs * 2, &j);
- ok = __virtnet_get_hw_stats(vi, ctx, req, sizeof(*req) * j, reply, res_size);
+ err = __virtnet_get_hw_stats(vi, ctx, req, sizeof(*req) * j, reply, res_size);
kfree(req);
kfree(reply);
- return ok;
+ return err;
}
static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
On Fri, May 10, 2024 at 03:50:45PM +0300, Dan Carpenter wrote:
> The virtnet_send_command_reply() function returns true on success or
> false on failure. The "ok" variable is true/false depending on whether
> it succeeds or not. It's up to the caller to translate the true/false
> into -EINVAL on failure or zero for success.
>
> The bug is that __virtnet_get_hw_stats() returns false for both
> errors and success. It's not a bug, but it is confusing that the caller
> virtnet_get_hw_stats() uses an "ok" variable to store negative error
> codes.
>
> Fix the bug and clean things up so that it's clear that
> __virtnet_get_hw_stats() returns zero on success or negative error codes
> on failure.
>
> Fixes: 941168f8b40e ("virtio_net: support device stats")
> Signed-off-by: Dan Carpenter <[email protected]>
Hi Dan, all,
Strictly this is doing two things. But I agree that the "ok" variable in
virtnet_get_hw_stats() was very confusing, and I'm not sure how long it
would have taken me to grasp the fix without that change being here too.
Reviewed-by: Simon Horman <[email protected]>
On Fri, May 10, 2024 at 03:50:45PM +0300, Dan Carpenter wrote:
> The virtnet_send_command_reply() function returns true on success or
> false on failure. The "ok" variable is true/false depending on whether
> it succeeds or not. It's up to the caller to translate the true/false
> into -EINVAL on failure or zero for success.
>
> The bug is that __virtnet_get_hw_stats() returns false for both
> errors and success. It's not a bug, but it is confusing that the caller
> virtnet_get_hw_stats() uses an "ok" variable to store negative error
> codes.
The bug is ... It's not a bug ....
I think what you are trying to say is that the error isn't
really handled anyway, except for printing a warning,
so it's not a big deal.
Right?
I don't know why can't get_ethtool_stats fail - we should
probably fix that.
> Fix the bug and clean things up so that it's clear that
> __virtnet_get_hw_stats() returns zero on success or negative error codes
> on failure.
>
> Fixes: 941168f8b40e ("virtio_net: support device stats")
> Signed-off-by: Dan Carpenter <[email protected]>
> ---
> drivers/net/virtio_net.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 218a446c4c27..4fc0fcdad259 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -4016,7 +4016,7 @@ static int __virtnet_get_hw_stats(struct virtnet_info *vi,
> &sgs_out, &sgs_in);
>
> if (!ok)
> - return ok;
> + return -EINVAL;
>
> for (p = reply; p - reply < res_size; p += le16_to_cpu(hdr->size)) {
> hdr = p;
> @@ -4053,7 +4053,7 @@ static int virtnet_get_hw_stats(struct virtnet_info *vi,
> struct virtio_net_ctrl_queue_stats *req;
> bool enable_cvq;
> void *reply;
> - int ok;
> + int err;
>
> if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_DEVICE_STATS))
> return 0;
> @@ -4100,12 +4100,12 @@ static int virtnet_get_hw_stats(struct virtnet_info *vi,
> if (enable_cvq)
> virtnet_make_stat_req(vi, ctx, req, vi->max_queue_pairs * 2, &j);
>
> - ok = __virtnet_get_hw_stats(vi, ctx, req, sizeof(*req) * j, reply, res_size);
> + err = __virtnet_get_hw_stats(vi, ctx, req, sizeof(*req) * j, reply, res_size);
>
> kfree(req);
> kfree(reply);
>
> - return ok;
> + return err;
> }
>
> static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
On Fri, 10 May 2024 15:50:45 +0300, Dan Carpenter <[email protected]> wrote:
> The virtnet_send_command_reply() function returns true on success or
> false on failure. The "ok" variable is true/false depending on whether
> it succeeds or not. It's up to the caller to translate the true/false
> into -EINVAL on failure or zero for success.
>
> The bug is that __virtnet_get_hw_stats() returns false for both
> errors and success. It's not a bug, but it is confusing that the caller
> virtnet_get_hw_stats() uses an "ok" variable to store negative error
> codes.
>
> Fix the bug and clean things up so that it's clear that
> __virtnet_get_hw_stats() returns zero on success or negative error codes
> on failure.
>
> Fixes: 941168f8b40e ("virtio_net: support device stats")
> Signed-off-by: Dan Carpenter <[email protected]>
That confused me too.
Reviewed-by: Xuan Zhuo <[email protected]>
Thanks.
> ---
> drivers/net/virtio_net.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 218a446c4c27..4fc0fcdad259 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -4016,7 +4016,7 @@ static int __virtnet_get_hw_stats(struct virtnet_info *vi,
> &sgs_out, &sgs_in);
>
> if (!ok)
> - return ok;
> + return -EINVAL;
>
> for (p = reply; p - reply < res_size; p += le16_to_cpu(hdr->size)) {
> hdr = p;
> @@ -4053,7 +4053,7 @@ static int virtnet_get_hw_stats(struct virtnet_info *vi,
> struct virtio_net_ctrl_queue_stats *req;
> bool enable_cvq;
> void *reply;
> - int ok;
> + int err;
>
> if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_DEVICE_STATS))
> return 0;
> @@ -4100,12 +4100,12 @@ static int virtnet_get_hw_stats(struct virtnet_info *vi,
> if (enable_cvq)
> virtnet_make_stat_req(vi, ctx, req, vi->max_queue_pairs * 2, &j);
>
> - ok = __virtnet_get_hw_stats(vi, ctx, req, sizeof(*req) * j, reply, res_size);
> + err = __virtnet_get_hw_stats(vi, ctx, req, sizeof(*req) * j, reply, res_size);
>
> kfree(req);
> kfree(reply);
>
> - return ok;
> + return err;
> }
>
> static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
>
On Sun, May 12, 2024 at 12:01:55PM -0400, Michael S. Tsirkin wrote:
> On Fri, May 10, 2024 at 03:50:45PM +0300, Dan Carpenter wrote:
> > The virtnet_send_command_reply() function returns true on success or
> > false on failure. The "ok" variable is true/false depending on whether
> > it succeeds or not. It's up to the caller to translate the true/false
> > into -EINVAL on failure or zero for success.
> >
> > The bug is that __virtnet_get_hw_stats() returns false for both
> > errors and success. It's not a bug, but it is confusing that the caller
> > virtnet_get_hw_stats() uses an "ok" variable to store negative error
> > codes.
>
> The bug is ... It's not a bug ....
>
> I think what you are trying to say is that the error isn't
> really handled anyway, except for printing a warning,
> so it's not a big deal.
>
> Right?
>
No, I'm sorry, that was confusing. The change to __virtnet_get_hw_stats()
is a bugfix but the change to virtnet_get_hw_stats() was not a bugfix.
I viewed this all as really one thing, because it's cleaning up the
error codes which happens to fix a bug. It seems very related. At the
same time, I can also see how people would disagree.
I'm traveling until May 23. I can resend this. Probably as two patches
for simpler review.
regards,
dan carpenter
On Wed, May 15, 2024 at 04:50:48PM +0200, Dan Carpenter wrote:
> On Sun, May 12, 2024 at 12:01:55PM -0400, Michael S. Tsirkin wrote:
> > On Fri, May 10, 2024 at 03:50:45PM +0300, Dan Carpenter wrote:
> > > The virtnet_send_command_reply() function returns true on success or
> > > false on failure. The "ok" variable is true/false depending on whether
> > > it succeeds or not. It's up to the caller to translate the true/false
> > > into -EINVAL on failure or zero for success.
> > >
> > > The bug is that __virtnet_get_hw_stats() returns false for both
> > > errors and success. It's not a bug, but it is confusing that the caller
> > > virtnet_get_hw_stats() uses an "ok" variable to store negative error
> > > codes.
> >
> > The bug is ... It's not a bug ....
> >
> > I think what you are trying to say is that the error isn't
> > really handled anyway, except for printing a warning,
> > so it's not a big deal.
> >
> > Right?
> >
>
> No, I'm sorry, that was confusing. The change to __virtnet_get_hw_stats()
> is a bugfix but the change to virtnet_get_hw_stats() was not a bugfix.
> I viewed this all as really one thing, because it's cleaning up the
> error codes which happens to fix a bug. It seems very related. At the
> same time, I can also see how people would disagree.
>
> I'm traveling until May 23. I can resend this. Probably as two patches
> for simpler review.
>
> regards,
> dan carpenter
>
Yea, no rush - bugfixes are fine after 23. And it's ok to combine into
one - we don't want inconsistent code - just please write a clear
commit log message.
--
MST