[PATCH AUTOSEL 6.12 429/486] net-sysfs: remove rtnl_trylock from queue attributes

From: Antoine Tenart atenart@kernel.org

[ Upstream commit b0b6fcfa6ad8433e22b050c72cfbeec2548744b9 ]

Similar to the commit removing remove rtnl_trylock from device attributes we here apply the same technique to networking queues.

Signed-off-by: Antoine Tenart atenart@kernel.org Link: https://patch.msgid.link/20250204170314.146022-5-atenart@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/net-sysfs.c | 147 ++++++++++++++++++++++++++----------------- 1 file changed, 89 insertions(+), 58 deletions(-)

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 05cf5347f25e8..b398a2e0c243d 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1213,9 +1213,11 @@ static int net_rx_queue_change_owner(struct net_device *dev, int num, */ struct netdev_queue_attribute { struct attribute attr; - ssize_t (*show)(struct netdev_queue *queue, char *buf); - ssize_t (*store)(struct netdev_queue *queue, - const char *buf, size_t len); + ssize_t (*show)(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf); + ssize_t (*store)(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, const char *buf, + size_t len); }; #define to_netdev_queue_attr(_attr) \ container_of(_attr, struct netdev_queue_attribute, attr) @@ -1232,7 +1234,7 @@ static ssize_t netdev_queue_attr_show(struct kobject *kobj, if (!attribute->show) return -EIO;

- return attribute->show(queue, buf); + return attribute->show(kobj, attr, queue, buf); }

static ssize_t netdev_queue_attr_store(struct kobject *kobj, @@ -1246,7 +1248,7 @@ static ssize_t netdev_queue_attr_store(struct kobject *kobj, if (!attribute->store) return -EIO;

- return attribute->store(queue, buf, count); + return attribute->store(kobj, attr, queue, buf, count); }

static const struct sysfs_ops netdev_queue_sysfs_ops = { @@ -1254,7 +1256,8 @@ static const struct sysfs_ops netdev_queue_sysfs_ops = { .store = netdev_queue_attr_store, };

-static ssize_t tx_timeout_show(struct netdev_queue *queue, char *buf) +static ssize_t tx_timeout_show(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { unsigned long trans_timeout = atomic_long_read(&queue->trans_timeout);

@@ -1272,18 +1275,18 @@ static unsigned int get_netdev_queue_index(struct netdev_queue *queue) return i; }

-static ssize_t traffic_class_show(struct netdev_queue *queue, - char *buf) +static ssize_t traffic_class_show(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { struct net_device *dev = queue->dev; - int num_tc, tc; - int index; + int num_tc, tc, index, ret;

if (!netif_is_multiqueue(dev)) return -ENOENT;

- if (!rtnl_trylock()) - return restart_syscall(); + ret = sysfs_rtnl_lock(kobj, attr, queue->dev); + if (ret) + return ret;

index = get_netdev_queue_index(queue);

@@ -1310,24 +1313,25 @@ static ssize_t traffic_class_show(struct netdev_queue *queue, }

#ifdef CONFIG_XPS -static ssize_t tx_maxrate_show(struct netdev_queue *queue, - char *buf) +static ssize_t tx_maxrate_show(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { return sysfs_emit(buf, "%lu\n", queue->tx_maxrate); }

-static ssize_t tx_maxrate_store(struct netdev_queue *queue, - const char *buf, size_t len) +static ssize_t tx_maxrate_store(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, const char *buf, + size_t len) { - struct net_device *dev = queue->dev; int err, index = get_netdev_queue_index(queue); + struct net_device *dev = queue->dev; u32 rate = 0;

if (!capable(CAP_NET_ADMIN)) return -EPERM;

/* The check is also done later; this helps returning early without - * hitting the trylock/restart below. + * hitting the locking section below. */ if (!dev->netdev_ops->ndo_set_tx_maxrate) return -EOPNOTSUPP; @@ -1336,18 +1340,21 @@ static ssize_t tx_maxrate_store(struct netdev_queue *queue, if (err < 0) return err;

- if (!rtnl_trylock()) - return restart_syscall(); + err = sysfs_rtnl_lock(kobj, attr, dev); + if (err) + return err;

err = -EOPNOTSUPP; if (dev->netdev_ops->ndo_set_tx_maxrate) err = dev->netdev_ops->ndo_set_tx_maxrate(dev, index, rate);

- rtnl_unlock(); if (!err) { queue->tx_maxrate = rate; + rtnl_unlock(); return len; } + + rtnl_unlock(); return err; }

@@ -1391,16 +1398,17 @@ static ssize_t bql_set(const char *buf, const size_t count, return count; }

-static ssize_t bql_show_hold_time(struct netdev_queue *queue, - char *buf) +static ssize_t bql_show_hold_time(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { struct dql *dql = &queue->dql;

return sysfs_emit(buf, "%u\n", jiffies_to_msecs(dql->slack_hold_time)); }

-static ssize_t bql_set_hold_time(struct netdev_queue *queue, - const char *buf, size_t len) +static ssize_t bql_set_hold_time(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, const char *buf, + size_t len) { struct dql *dql = &queue->dql; unsigned int value; @@ -1419,15 +1427,17 @@ static struct netdev_queue_attribute bql_hold_time_attribute __ro_after_init = __ATTR(hold_time, 0644, bql_show_hold_time, bql_set_hold_time);

-static ssize_t bql_show_stall_thrs(struct netdev_queue *queue, char *buf) +static ssize_t bql_show_stall_thrs(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { struct dql *dql = &queue->dql;

return sysfs_emit(buf, "%u\n", jiffies_to_msecs(dql->stall_thrs)); }

-static ssize_t bql_set_stall_thrs(struct netdev_queue *queue, - const char *buf, size_t len) +static ssize_t bql_set_stall_thrs(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, const char *buf, + size_t len) { struct dql *dql = &queue->dql; unsigned int value; @@ -1453,13 +1463,15 @@ static ssize_t bql_set_stall_thrs(struct netdev_queue *queue, static struct netdev_queue_attribute bql_stall_thrs_attribute __ro_after_init = __ATTR(stall_thrs, 0644, bql_show_stall_thrs, bql_set_stall_thrs);

-static ssize_t bql_show_stall_max(struct netdev_queue *queue, char *buf) +static ssize_t bql_show_stall_max(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { return sysfs_emit(buf, "%u\n", READ_ONCE(queue->dql.stall_max)); }

-static ssize_t bql_set_stall_max(struct netdev_queue *queue, - const char *buf, size_t len) +static ssize_t bql_set_stall_max(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, const char *buf, + size_t len) { WRITE_ONCE(queue->dql.stall_max, 0); return len; @@ -1468,7 +1480,8 @@ static ssize_t bql_set_stall_max(struct netdev_queue *queue, static struct netdev_queue_attribute bql_stall_max_attribute __ro_after_init = __ATTR(stall_max, 0644, bql_show_stall_max, bql_set_stall_max);

-static ssize_t bql_show_stall_cnt(struct netdev_queue *queue, char *buf) +static ssize_t bql_show_stall_cnt(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { struct dql *dql = &queue->dql;

@@ -1478,8 +1491,8 @@ static ssize_t bql_show_stall_cnt(struct netdev_queue *queue, char *buf) static struct netdev_queue_attribute bql_stall_cnt_attribute __ro_after_init = __ATTR(stall_cnt, 0444, bql_show_stall_cnt, NULL);

-static ssize_t bql_show_inflight(struct netdev_queue *queue, - char *buf) +static ssize_t bql_show_inflight(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { struct dql *dql = &queue->dql;

@@ -1490,13 +1503,16 @@ static struct netdev_queue_attribute bql_inflight_attribute __ro_after_init = __ATTR(inflight, 0444, bql_show_inflight, NULL);

#define BQL_ATTR(NAME, FIELD) \ -static ssize_t bql_show_ ## NAME(struct netdev_queue *queue, \ - char *buf) \ +static ssize_t bql_show_ ## NAME(struct kobject *kobj, \ + struct attribute *attr, \ + struct netdev_queue *queue, char *buf) \ { \ return bql_show(buf, queue->dql.FIELD); \ } \ \ -static ssize_t bql_set_ ## NAME(struct netdev_queue *queue, \ +static ssize_t bql_set_ ## NAME(struct kobject *kobj, \ + struct attribute *attr, \ + struct netdev_queue *queue, \ const char *buf, size_t len) \ { \ return bql_set(buf, len, &queue->dql.FIELD); \ @@ -1582,19 +1598,21 @@ static ssize_t xps_queue_show(struct net_device *dev, unsigned int index, return len < PAGE_SIZE ? len : -EINVAL; }

-static ssize_t xps_cpus_show(struct netdev_queue *queue, char *buf) +static ssize_t xps_cpus_show(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { struct net_device *dev = queue->dev; unsigned int index; - int len, tc; + int len, tc, ret;

if (!netif_is_multiqueue(dev)) return -ENOENT;

index = get_netdev_queue_index(queue);

- if (!rtnl_trylock()) - return restart_syscall(); + ret = sysfs_rtnl_lock(kobj, attr, queue->dev); + if (ret) + return ret;

/* If queue belongs to subordinate dev use its map */ dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev; @@ -1605,18 +1623,21 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue, char *buf) return -EINVAL; }

- /* Make sure the subordinate device can't be freed */ - get_device(&dev->dev); + /* Increase the net device refcnt to make sure it won't be freed while + * xps_queue_show is running. + */ + dev_hold(dev); rtnl_unlock();

len = xps_queue_show(dev, index, tc, buf, XPS_CPUS);

- put_device(&dev->dev); + dev_put(dev); return len; }

-static ssize_t xps_cpus_store(struct netdev_queue *queue, - const char *buf, size_t len) +static ssize_t xps_cpus_store(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, const char *buf, + size_t len) { struct net_device *dev = queue->dev; unsigned int index; @@ -1640,9 +1661,10 @@ static ssize_t xps_cpus_store(struct netdev_queue *queue, return err; }

- if (!rtnl_trylock()) { + err = sysfs_rtnl_lock(kobj, attr, dev); + if (err) { free_cpumask_var(mask); - return restart_syscall(); + return err; }

err = netif_set_xps_queue(dev, mask, index); @@ -1656,26 +1678,34 @@ static ssize_t xps_cpus_store(struct netdev_queue *queue, static struct netdev_queue_attribute xps_cpus_attribute __ro_after_init = __ATTR_RW(xps_cpus);

-static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) +static ssize_t xps_rxqs_show(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, char *buf) { struct net_device *dev = queue->dev; unsigned int index; - int tc; + int tc, ret;

index = get_netdev_queue_index(queue);

- if (!rtnl_trylock()) - return restart_syscall(); + ret = sysfs_rtnl_lock(kobj, attr, dev); + if (ret) + return ret;

tc = netdev_txq_to_tc(dev, index); + + /* Increase the net device refcnt to make sure it won't be freed while + * xps_queue_show is running. + */ + dev_hold(dev); rtnl_unlock(); - if (tc < 0) - return -EINVAL;

- return xps_queue_show(dev, index, tc, buf, XPS_RXQS); + ret = tc >= 0 ? xps_queue_show(dev, index, tc, buf, XPS_RXQS) : -EINVAL; + dev_put(dev); + return ret; }

-static ssize_t xps_rxqs_store(struct netdev_queue *queue, const char *buf, +static ssize_t xps_rxqs_store(struct kobject *kobj, struct attribute *attr, + struct netdev_queue *queue, const char *buf, size_t len) { struct net_device *dev = queue->dev; @@ -1699,9 +1729,10 @@ static ssize_t xps_rxqs_store(struct netdev_queue *queue, const char *buf, return err; }

- if (!rtnl_trylock()) { + err = sysfs_rtnl_lock(kobj, attr, dev); + if (err) { bitmap_free(mask); - return restart_syscall(); + return err; }

cpus_read_lock();