From d7dac083414eb5bb99a6d2ed53dc2c1b405224e5 Mon Sep 17 00:00:00 2001 From: Antoine Tenart Date: Tue, 7 Dec 2021 15:57:24 +0100 Subject: net-sysfs: update the queue counts in the unregistration path When updating Rx and Tx queue kobjects, the queue count should always be updated to match the queue kobjects count. This was not done in the net device unregistration path, fix it. Tracking all queue count updates will allow in a following up patch to detect illegal updates. Signed-off-by: Antoine Tenart Signed-off-by: Jakub Kicinski --- net/core/net-sysfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 3b2cdbbdc858..33f408c24205 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1808,6 +1808,9 @@ static void remove_queue_kobjects(struct net_device *dev) net_rx_queue_update_kobjects(dev, real_rx, 0); netdev_queue_update_kobjects(dev, real_tx, 0); + + dev->real_num_rx_queues = 0; + dev->real_num_tx_queues = 0; #ifdef CONFIG_SYSFS kset_unregister(dev->queues_kset); #endif -- cgit v1.2.3 From 5f1c802ca69b3c076eea5fabc8839ffa5ddd8c8f Mon Sep 17 00:00:00 2001 From: Antoine Tenart Date: Tue, 7 Dec 2021 15:57:25 +0100 Subject: net-sysfs: warn if new queue objects are being created during device unregistration Calling netdev_queue_update_kobjects is allowed during device unregistration since commit 5c56580b74e5 ("net: Adjust TX queue kobjects if number of queues changes during unregister"). But this is solely to allow queue unregistrations. Any path attempting to add new queues after a device started its unregistration should be fixed. This patch adds a warning to detect such illegal use. Signed-off-by: Antoine Tenart Signed-off-by: Jakub Kicinski --- net/core/net-sysfs.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 33f408c24205..53ea262ecafd 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1694,6 +1694,13 @@ netdev_queue_update_kobjects(struct net_device *dev, int old_num, int new_num) int i; int error = 0; + /* Tx queue kobjects are allowed to be updated when a device is being + * unregistered, but solely to remove queues from qdiscs. Any path + * adding queues should be fixed. + */ + WARN(dev->reg_state == NETREG_UNREGISTERING && new_num > old_num, + "New queues can't be registered after device unregistration."); + for (i = old_num; i < new_num; i++) { error = netdev_queue_add_kobject(dev, i); if (error) { -- cgit v1.2.3