include/linux/netdevice.h | 2 +- net/core/net-sysfs.c | 68 +++++++++++++++++++++++---------------- 2 files changed, 42 insertions(+), 28 deletions(-)
phys_port_id_show, phys_port_name_show and phys_switch_id_show would
return -EOPNOTSUPP if the netdev didn't implement the corresponding
method.
There is no point in creating these files if they are unsupported.
Put these attributes in netdev_phys_group and implement the is_visible
method. make phys_(port_id, port_name, switch_id) invisible if the netdev
dosen't implement the corresponding method.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
v2: Remove worthless comments
v1: https://lore.kernel.org/all/20250515130205.3274-1-yajun.deng@linux.dev/
---
include/linux/netdevice.h | 2 +-
net/core/net-sysfs.c | 68 +++++++++++++++++++++++----------------
2 files changed, 42 insertions(+), 28 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 32a1e41636a9..efbcc4836498 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2384,7 +2384,7 @@ struct net_device {
struct dm_hw_stat_delta __rcu *dm_private;
#endif
struct device dev;
- const struct attribute_group *sysfs_groups[4];
+ const struct attribute_group *sysfs_groups[5];
const struct attribute_group *sysfs_rx_queue_group;
const struct rtnl_link_ops *rtnl_link_ops;
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 1ace0cd01adc..f626dcd66d03 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -641,12 +641,6 @@ static ssize_t phys_port_id_show(struct device *dev,
struct netdev_phys_item_id ppid;
ssize_t ret;
- /* The check is also done in dev_get_phys_port_id; this helps returning
- * early without hitting the locking section below.
- */
- if (!netdev->netdev_ops->ndo_get_phys_port_id)
- return -EOPNOTSUPP;
-
ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev);
if (ret)
return ret;
@@ -659,7 +653,8 @@ static ssize_t phys_port_id_show(struct device *dev,
return ret;
}
-static DEVICE_ATTR_RO(phys_port_id);
+static struct device_attribute dev_attr_phys_port_id =
+ __ATTR(phys_port_id, 0444, phys_port_id_show, NULL);
static ssize_t phys_port_name_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -668,13 +663,6 @@ static ssize_t phys_port_name_show(struct device *dev,
char name[IFNAMSIZ];
ssize_t ret;
- /* The checks are also done in dev_get_phys_port_name; this helps
- * returning early without hitting the locking section below.
- */
- if (!netdev->netdev_ops->ndo_get_phys_port_name &&
- !netdev->devlink_port)
- return -EOPNOTSUPP;
-
ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev);
if (ret)
return ret;
@@ -687,7 +675,8 @@ static ssize_t phys_port_name_show(struct device *dev,
return ret;
}
-static DEVICE_ATTR_RO(phys_port_name);
+static struct device_attribute dev_attr_phys_port_name =
+ __ATTR(phys_port_name, 0444, phys_port_name_show, NULL);
static ssize_t phys_switch_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -696,14 +685,6 @@ static ssize_t phys_switch_id_show(struct device *dev,
struct netdev_phys_item_id ppid = { };
ssize_t ret;
- /* The checks are also done in dev_get_phys_port_name; this helps
- * returning early without hitting the locking section below. This works
- * because recurse is false when calling dev_get_port_parent_id.
- */
- if (!netdev->netdev_ops->ndo_get_port_parent_id &&
- !netdev->devlink_port)
- return -EOPNOTSUPP;
-
ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev);
if (ret)
return ret;
@@ -716,7 +697,42 @@ static ssize_t phys_switch_id_show(struct device *dev,
return ret;
}
-static DEVICE_ATTR_RO(phys_switch_id);
+static struct device_attribute dev_attr_phys_switch_id =
+ __ATTR(phys_switch_id, 0444, phys_switch_id_show, NULL);
+
+static struct attribute *netdev_phys_attrs[] __ro_after_init = {
+ &dev_attr_phys_port_id.attr,
+ &dev_attr_phys_port_name.attr,
+ &dev_attr_phys_switch_id.attr,
+ NULL,
+};
+
+static umode_t netdev_phys_is_visible(struct kobject *kobj,
+ struct attribute *attr, int index)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct net_device *netdev = to_net_dev(dev);
+
+ if (attr == &dev_attr_phys_port_id.attr) {
+ if (!netdev->netdev_ops->ndo_get_phys_port_id)
+ return 0;
+ } else if (attr == &dev_attr_phys_port_name.attr) {
+ if (!netdev->netdev_ops->ndo_get_phys_port_name &&
+ !netdev->devlink_port)
+ return 0;
+ } else if (attr == &dev_attr_phys_switch_id.attr) {
+ if (!netdev->netdev_ops->ndo_get_port_parent_id &&
+ !netdev->devlink_port)
+ return 0;
+ }
+
+ return attr->mode;
+}
+
+static const struct attribute_group netdev_phys_group = {
+ .attrs = netdev_phys_attrs,
+ .is_visible = netdev_phys_is_visible,
+};
static ssize_t threaded_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -783,9 +799,6 @@ static struct attribute *net_class_attrs[] __ro_after_init = {
&dev_attr_tx_queue_len.attr,
&dev_attr_gro_flush_timeout.attr,
&dev_attr_napi_defer_hard_irqs.attr,
- &dev_attr_phys_port_id.attr,
- &dev_attr_phys_port_name.attr,
- &dev_attr_phys_switch_id.attr,
&dev_attr_proto_down.attr,
&dev_attr_carrier_up_count.attr,
&dev_attr_carrier_down_count.attr,
@@ -2328,6 +2341,7 @@ int netdev_register_kobject(struct net_device *ndev)
groups++;
*groups++ = &netstat_group;
+ *groups++ = &netdev_phys_group;
if (wireless_group_needed(ndev))
*groups++ = &wireless_group;
--
2.25.1On 5/21/25 4:08 PM, Yajun Deng wrote: > phys_port_id_show, phys_port_name_show and phys_switch_id_show would > return -EOPNOTSUPP if the netdev didn't implement the corresponding > method. > > There is no point in creating these files if they are unsupported. > > Put these attributes in netdev_phys_group and implement the is_visible > method. make phys_(port_id, port_name, switch_id) invisible if the netdev > dosen't implement the corresponding method. > > Signed-off-by: Yajun Deng <yajun.deng@linux.dev> I fear that some orchestration infra depends on the files existence - i.e. scripts don't tolerate the files absence, deal only with I/O errors after open. It feel a bit too dangerous to merge a change that could break user-space this late. Let's defer it to the beginning of the next cycle. Paolo
May 27, 2025 at 2:08 PM, "Paolo Abeni" <pabeni@redhat.com> wrote: > > On 5/21/25 4:08 PM, Yajun Deng wrote: > > > > > phys_port_id_show, phys_port_name_show and phys_switch_id_show would > > > > return -EOPNOTSUPP if the netdev didn't implement the corresponding > > > > method. > > > > > > > > There is no point in creating these files if they are unsupported. > > > > > > > > Put these attributes in netdev_phys_group and implement the is_visible > > > > method. make phys_(port_id, port_name, switch_id) invisible if the netdev > > > > dosen't implement the corresponding method. > > > > > > > > Signed-off-by: Yajun Deng <yajun.deng@linux.dev> > > > > I fear that some orchestration infra depends on the files existence - > > i.e. scripts don't tolerate the files absence, deal only with I/O errors > > after open. > > It feel a bit too dangerous to merge a change that could break > > user-space this late. Let's defer it to the beginning of the next cycle. > Ping. > Paolo >
On 6/12/25 10:51 AM, Yajun Deng wrote: > May 27, 2025 at 2:08 PM, "Paolo Abeni" <pabeni@redhat.com> wrote: >> On 5/21/25 4:08 PM, Yajun Deng wrote: >>> phys_port_id_show, phys_port_name_show and phys_switch_id_show would >>> >>> return -EOPNOTSUPP if the netdev didn't implement the corresponding >>> >>> method. >>> >>> >>> >>> There is no point in creating these files if they are unsupported. >>> >>> >>> >>> Put these attributes in netdev_phys_group and implement the is_visible >>> >>> method. make phys_(port_id, port_name, switch_id) invisible if the netdev >>> >>> dosen't implement the corresponding method. >>> >>> >>> >>> Signed-off-by: Yajun Deng <yajun.deng@linux.dev> >>> >> >> I fear that some orchestration infra depends on the files existence - >> >> i.e. scripts don't tolerate the files absence, deal only with I/O errors >> >> after open. >> >> It feel a bit too dangerous to merge a change that could break >> >> user-space this late. Let's defer it to the beginning of the next cycle. >> > > Ping. I was likely not clear. The above means you should re-submit the patch now. /P
On Wed, May 21, 2025 at 10:08:24PM +0800, Yajun Deng wrote: > phys_port_id_show, phys_port_name_show and phys_switch_id_show would > return -EOPNOTSUPP if the netdev didn't implement the corresponding > method. > > There is no point in creating these files if they are unsupported. > > Put these attributes in netdev_phys_group and implement the is_visible > method. make phys_(port_id, port_name, switch_id) invisible if the netdev > dosen't implement the corresponding method. > > Signed-off-by: Yajun Deng <yajun.deng@linux.dev> > --- > v2: Remove worthless comments > v1: https://lore.kernel.org/all/20250515130205.3274-1-yajun.deng@linux.dev/ Reviewed-by: Simon Horman <horms@kernel.org> FWIIW, I had the same thought that Jakub related in his review of v1. "I'm slightly worried some user space depends on the files existing, but maybe ENOENT vs EOPNOTSUPP doesn't make a big difference.| ...
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