[v1] netconsole: Add taskname sysdata support

[PATCH net-next 4/7] netconsole: add configfs controls for taskname sysdata feature

Posted by Breno Leitao 11 months, 3 weeks ago

Add configfs interface to enable/disable the taskname sysdata feature.
This adds the following functionality:

The implementation follows the same pattern as the existing CPU number
feature, ensuring consistent behavior and error handling across sysdata
features.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 drivers/net/netconsole.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 1b109f46512ffb7628c6b34c6efdfc301376dd53..5a29144ae37ee7b487b1a252b0f2ce8574f9cefa 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -426,6 +426,20 @@ static ssize_t sysdata_cpu_nr_enabled_show(struct config_item *item, char *buf)
 	return sysfs_emit(buf, "%d\n", cpu_nr_enabled);
 }
 
+/* configfs helper to display if taskname sysdata feature is enabled */
+static ssize_t sysdata_taskname_enabled_show(struct config_item *item,
+					     char *buf)
+{
+	struct netconsole_target *nt = to_target(item->ci_parent);
+	bool taskname_enabled;
+
+	mutex_lock(&dynamic_netconsole_mutex);
+	taskname_enabled = !!(nt->sysdata_fields & SYSDATA_TASKNAME);
+	mutex_unlock(&dynamic_netconsole_mutex);
+
+	return sysfs_emit(buf, "%d\n", taskname_enabled);
+}
+
 /*
  * This one is special -- targets created through the configfs interface
  * are not enabled (and the corresponding netpoll activated) by default.
@@ -841,6 +855,40 @@ static void disable_sysdata_feature(struct netconsole_target *nt,
 	nt->extradata_complete[nt->userdata_length] = 0;
 }
 
+static ssize_t sysdata_taskname_enabled_store(struct config_item *item,
+					      const char *buf, size_t count)
+{
+	struct netconsole_target *nt = to_target(item->ci_parent);
+	bool taskname_enabled, curr;
+	ssize_t ret;
+
+	ret = kstrtobool(buf, &taskname_enabled);
+	if (ret)
+		return ret;
+
+	mutex_lock(&dynamic_netconsole_mutex);
+	curr = nt->sysdata_fields & SYSDATA_TASKNAME;
+	if (taskname_enabled == curr)
+		goto unlock_ok;
+
+	if (taskname_enabled &&
+	    count_extradata_entries(nt) >= MAX_EXTRADATA_ITEMS) {
+		ret = -ENOSPC;
+		goto unlock;
+	}
+
+	if (taskname_enabled)
+		nt->sysdata_fields |= SYSDATA_TASKNAME;
+	else
+		disable_sysdata_feature(nt, SYSDATA_TASKNAME);
+
+unlock_ok:
+	ret = strnlen(buf, count);
+unlock:
+	mutex_unlock(&dynamic_netconsole_mutex);
+	return ret;
+}
+
 /* configfs helper to sysdata cpu_nr feature */
 static ssize_t sysdata_cpu_nr_enabled_store(struct config_item *item,
 					    const char *buf, size_t count)
@@ -886,6 +934,7 @@ static ssize_t sysdata_cpu_nr_enabled_store(struct config_item *item,
 
 CONFIGFS_ATTR(userdatum_, value);
 CONFIGFS_ATTR(sysdata_, cpu_nr_enabled);
+CONFIGFS_ATTR(sysdata_, taskname_enabled);
 
 static struct configfs_attribute *userdatum_attrs[] = {
 	&userdatum_attr_value,
@@ -946,6 +995,7 @@ static void userdatum_drop(struct config_group *group, struct config_item *item)
 
 static struct configfs_attribute *userdata_attrs[] = {
 	&sysdata_attr_cpu_nr_enabled,
+	&sysdata_attr_taskname_enabled,
 	NULL,
 };
 

-- 
2.43.5

Re: [PATCH net-next 4/7] netconsole: add configfs controls for taskname sysdata feature

Posted by Paolo Abeni 11 months, 2 weeks ago

On 2/21/25 2:52 PM, Breno Leitao wrote:
> Add configfs interface to enable/disable the taskname sysdata feature.
> This adds the following functionality:
> 
> The implementation follows the same pattern as the existing CPU number
> feature, ensuring consistent behavior and error handling across sysdata
> features.
> 
> Signed-off-by: Breno Leitao <leitao@debian.org>
> ---
>  drivers/net/netconsole.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
> 
> diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> index 1b109f46512ffb7628c6b34c6efdfc301376dd53..5a29144ae37ee7b487b1a252b0f2ce8574f9cefa 100644
> --- a/drivers/net/netconsole.c
> +++ b/drivers/net/netconsole.c
> @@ -426,6 +426,20 @@ static ssize_t sysdata_cpu_nr_enabled_show(struct config_item *item, char *buf)
>  	return sysfs_emit(buf, "%d\n", cpu_nr_enabled);
>  }
>  
> +/* configfs helper to display if taskname sysdata feature is enabled */
> +static ssize_t sysdata_taskname_enabled_show(struct config_item *item,
> +					     char *buf)
> +{
> +	struct netconsole_target *nt = to_target(item->ci_parent);
> +	bool taskname_enabled;
> +
> +	mutex_lock(&dynamic_netconsole_mutex);
> +	taskname_enabled = !!(nt->sysdata_fields & SYSDATA_TASKNAME);
> +	mutex_unlock(&dynamic_netconsole_mutex);
> +
> +	return sysfs_emit(buf, "%d\n", taskname_enabled);
> +}
> +
>  /*
>   * This one is special -- targets created through the configfs interface
>   * are not enabled (and the corresponding netpoll activated) by default.
> @@ -841,6 +855,40 @@ static void disable_sysdata_feature(struct netconsole_target *nt,
>  	nt->extradata_complete[nt->userdata_length] = 0;
>  }
>  
> +static ssize_t sysdata_taskname_enabled_store(struct config_item *item,
> +					      const char *buf, size_t count)
> +{
> +	struct netconsole_target *nt = to_target(item->ci_parent);
> +	bool taskname_enabled, curr;
> +	ssize_t ret;
> +
> +	ret = kstrtobool(buf, &taskname_enabled);
> +	if (ret)
> +		return ret;
> +
> +	mutex_lock(&dynamic_netconsole_mutex);
> +	curr = nt->sysdata_fields & SYSDATA_TASKNAME;

Minor nit:
	curr = !!(nt->sysdata_fields & SYSDATA_TASKNAME);

would be preferable, and more robust if later on other SYSDATA_ bits are
added, 'moving down' SYSDATA_TASKNAME definition.

Also it would be more consistent with previous usage in
`sysdata_taskname_enabled_show()`

Cheers,

Paolo

Re: [PATCH net-next 4/7] netconsole: add configfs controls for taskname sysdata feature

Posted by Breno Leitao 11 months, 2 weeks ago

On Tue, Feb 25, 2025 at 12:41:50PM +0100, Paolo Abeni wrote:
> On 2/21/25 2:52 PM, Breno Leitao wrote:
> > Add configfs interface to enable/disable the taskname sysdata feature.
> > This adds the following functionality:
> > 
> > The implementation follows the same pattern as the existing CPU number
> > feature, ensuring consistent behavior and error handling across sysdata
> > features.
> > 
> > Signed-off-by: Breno Leitao <leitao@debian.org>
> > ---
> >  drivers/net/netconsole.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 50 insertions(+)
> > 
> > diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> > index 1b109f46512ffb7628c6b34c6efdfc301376dd53..5a29144ae37ee7b487b1a252b0f2ce8574f9cefa 100644
> > --- a/drivers/net/netconsole.c
> > +++ b/drivers/net/netconsole.c
> > @@ -426,6 +426,20 @@ static ssize_t sysdata_cpu_nr_enabled_show(struct config_item *item, char *buf)
> >  	return sysfs_emit(buf, "%d\n", cpu_nr_enabled);
> >  }
> >  
> > +/* configfs helper to display if taskname sysdata feature is enabled */
> > +static ssize_t sysdata_taskname_enabled_show(struct config_item *item,
> > +					     char *buf)
> > +{
> > +	struct netconsole_target *nt = to_target(item->ci_parent);
> > +	bool taskname_enabled;
> > +
> > +	mutex_lock(&dynamic_netconsole_mutex);
> > +	taskname_enabled = !!(nt->sysdata_fields & SYSDATA_TASKNAME);
> > +	mutex_unlock(&dynamic_netconsole_mutex);
> > +
> > +	return sysfs_emit(buf, "%d\n", taskname_enabled);
> > +}
> > +
> >  /*
> >   * This one is special -- targets created through the configfs interface
> >   * are not enabled (and the corresponding netpoll activated) by default.
> > @@ -841,6 +855,40 @@ static void disable_sysdata_feature(struct netconsole_target *nt,
> >  	nt->extradata_complete[nt->userdata_length] = 0;
> >  }
> >  
> > +static ssize_t sysdata_taskname_enabled_store(struct config_item *item,
> > +					      const char *buf, size_t count)
> > +{
> > +	struct netconsole_target *nt = to_target(item->ci_parent);
> > +	bool taskname_enabled, curr;
> > +	ssize_t ret;
> > +
> > +	ret = kstrtobool(buf, &taskname_enabled);
> > +	if (ret)
> > +		return ret;
> > +
> > +	mutex_lock(&dynamic_netconsole_mutex);
> > +	curr = nt->sysdata_fields & SYSDATA_TASKNAME;
> 
> Minor nit:
> 	curr = !!(nt->sysdata_fields & SYSDATA_TASKNAME);
> 
> would be preferable, and more robust if later on other SYSDATA_ bits are
> added, 'moving down' SYSDATA_TASKNAME definition.
> 
> Also it would be more consistent with previous usage in
> `sysdata_taskname_enabled_show()`

Good point, in fact. I will update!

Thanks for the review,
--breno

Re: [PATCH net-next 4/7] netconsole: add configfs controls for taskname sysdata feature

Posted by Simon Horman 11 months, 2 weeks ago

On Fri, Feb 21, 2025 at 05:52:09AM -0800, Breno Leitao wrote:
> Add configfs interface to enable/disable the taskname sysdata feature.
> This adds the following functionality:
> 
> The implementation follows the same pattern as the existing CPU number
> feature, ensuring consistent behavior and error handling across sysdata
> features.
> 
> Signed-off-by: Breno Leitao <leitao@debian.org>

Reviewed-by: Simon Horman <horms@kernel.org>

[PATCH net-next 1/7] netconsole: prefix CPU_NR sysdata feature with SYSDATA_
[PATCH net-next 2/7] netconsole: refactor CPU number formatting into separate function
[PATCH net-next 3/7] netconsole: add taskname to extradata entry count
[PATCH net-next 4/7] netconsole: add configfs controls for taskname sysdata feature
[PATCH net-next 5/7] netconsole: add task name to extra data fields
[PATCH net-next 6/7] netconsole: docs: document the task name feature
[PATCH net-next 7/7] netconsole: selftest: add task name append testing