bonding: no longer use RTNL in bonding_show_queue_id()

Annotate lockless reads of slave->queue_id.

Annotate writes of slave->queue_id.

Switch bonding_show_queue_id() to rcu_read_lock()
and bond_for_each_slave_rcu().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Link: https://lore.kernel.org/r/20240408190437.2214473-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 08e9bdbf450afdc103931249259c58a08665dc02..b3a7d60c3a5ca60be1d9eed184ec1dad593a182b 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -5245,7 +5245,7 @@ static inline int bond_slave_override(struct bonding *bond,
 
        /* Find out if any slaves have the same mapping as this skb. */
        bond_for_each_slave_rcu(bond, slave, iter) {
-               if (slave->queue_id == skb_get_queue_mapping(skb)) {
+               if (READ_ONCE(slave->queue_id) == skb_get_queue_mapping(skb)) {
                        if (bond_slave_is_up(slave) &&
                            slave->link == BOND_LINK_UP) {
                                bond_dev_queue_xmit(bond, skb, slave->dev);

diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
index 29b4c3d1b9b6ff873fe067e80bedf7cb681d18f1..2a6a424806aa603ad8a00ca797e9e22d38bd0435 100644 (file)
--- a/drivers/net/bonding/bond_netlink.c
+++ b/drivers/net/bonding/bond_netlink.c
@@ -51,7 +51,8 @@ static int bond_fill_slave_info(struct sk_buff *skb,
                    slave_dev->addr_len, slave->perm_hwaddr))
                goto nla_put_failure;
 
-       if (nla_put_u16(skb, IFLA_BOND_SLAVE_QUEUE_ID, slave->queue_id))
+       if (nla_put_u16(skb, IFLA_BOND_SLAVE_QUEUE_ID,
+                       READ_ONCE(slave->queue_id)))
                goto nla_put_failure;
 
        if (nla_put_s32(skb, IFLA_BOND_SLAVE_PRIO, slave->prio))

diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index 4cdbc7e084f4b4cb3b150656aa765531806d8ad9..0cacd7027e352dbf3204d82b7ce1672469a186de 100644 (file)
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -1589,7 +1589,7 @@ static int bond_option_queue_id_set(struct bonding *bond,
                goto err_no_cmd;
 
        /* Actually set the qids for the slave */
-       update_slave->queue_id = qid;
+       WRITE_ONCE(update_slave->queue_id, qid);
 
 out:
        return ret;

diff --git a/drivers/net/bonding/bond_procfs.c b/drivers/net/bonding/bond_procfs.c
index 43be458422b3f9448d96383b0fb140837562f446..7edf72ec816abd8b66917bdecd2c93d237629ffa 100644 (file)
--- a/drivers/net/bonding/bond_procfs.c
+++ b/drivers/net/bonding/bond_procfs.c
@@ -209,7 +209,7 @@ static void bond_info_show_slave(struct seq_file *seq,
 
        seq_printf(seq, "Permanent HW addr: %*phC\n",
                   slave->dev->addr_len, slave->perm_hwaddr);
-       seq_printf(seq, "Slave queue ID: %d\n", slave->queue_id);
+       seq_printf(seq, "Slave queue ID: %d\n", READ_ONCE(slave->queue_id));
 
        if (BOND_MODE(bond) == BOND_MODE_8023AD) {
                const struct port *port = &SLAVE_AD_INFO(slave)->port;

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 75ee7ca369034ef6fa58fc9399b566dd7044fedc..1e13bb17051567e2b5d9451ceef47f2cf1a588ec 100644 (file)
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -625,10 +625,9 @@ static ssize_t bonding_show_queue_id(struct device *d,
        struct slave *slave;
        int res = 0;
 
-       if (!rtnl_trylock())
-               return restart_syscall();
+       rcu_read_lock();
 
-       bond_for_each_slave(bond, slave, iter) {
+       bond_for_each_slave_rcu(bond, slave, iter) {
                if (res > (PAGE_SIZE - IFNAMSIZ - 6)) {
                        /* not enough space for another interface_name:queue_id pair */
                        if ((PAGE_SIZE - res) > 10)
@@ -637,12 +636,13 @@ static ssize_t bonding_show_queue_id(struct device *d,
                        break;
                }
                res += sysfs_emit_at(buf, res, "%s:%d ",
-                                    slave->dev->name, slave->queue_id);
+                                    slave->dev->name,
+                                    READ_ONCE(slave->queue_id));
        }
        if (res)
                buf[res-1] = '\n'; /* eat the leftover space */
 
-       rtnl_unlock();
+       rcu_read_unlock();
 
        return res;
 }

diff --git a/drivers/net/bonding/bond_sysfs_slave.c b/drivers/net/bonding/bond_sysfs_slave.c
index 313866f2c0e49ac96299ffea307b1613955713ec..36d0e8440b5b94464b3226ce1a04f32361de5aa6 100644 (file)
--- a/drivers/net/bonding/bond_sysfs_slave.c
+++ b/drivers/net/bonding/bond_sysfs_slave.c
@@ -53,7 +53,7 @@ static SLAVE_ATTR_RO(perm_hwaddr);
 
 static ssize_t queue_id_show(struct slave *slave, char *buf)
 {
-       return sysfs_emit(buf, "%d\n", slave->queue_id);
+       return sysfs_emit(buf, "%d\n", READ_ONCE(slave->queue_id));
 }
 static SLAVE_ATTR_RO(queue_id);