net: sched: wrap doit/dumpit methods

In preparation for grabbing netdev instance lock around qdisc
operations, introduce tc_xxx wrappers that lookup netdev
and call respective __tc_xxx helper to do the actual work.
No functional changes.

Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Saeed Mahameed <saeed@kernel.org>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-4-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index e3e91cf867eb99e41bac93ec30f6af3de777ce56..21940f3ae66f9adc16ccda25f264151ce1dd1b8f 100644 (file)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1505,27 +1505,18 @@ const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
  * Delete/get qdisc.
  */
 
-static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
-                       struct netlink_ext_ack *extack)
+static int __tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
+                         struct netlink_ext_ack *extack,
+                         struct net_device *dev,
+                         struct nlattr *tca[TCA_MAX + 1],
+                         struct tcmsg *tcm)
 {
        struct net *net = sock_net(skb->sk);
-       struct tcmsg *tcm = nlmsg_data(n);
-       struct nlattr *tca[TCA_MAX + 1];
-       struct net_device *dev;
-       u32 clid;
        struct Qdisc *q = NULL;
        struct Qdisc *p = NULL;
+       u32 clid;
        int err;
 
-       err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
-                                    rtm_tca_policy, extack);
-       if (err < 0)
-               return err;
-
-       dev = __dev_get_by_index(net, tcm->tcm_ifindex);
-       if (!dev)
-               return -ENODEV;
-
        clid = tcm->tcm_parent;
        if (clid) {
                if (clid != TC_H_ROOT) {
@@ -1582,6 +1573,27 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
        return 0;
 }
 
+static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
+                       struct netlink_ext_ack *extack)
+{
+       struct net *net = sock_net(skb->sk);
+       struct tcmsg *tcm = nlmsg_data(n);
+       struct nlattr *tca[TCA_MAX + 1];
+       struct net_device *dev;
+       int err;
+
+       err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
+                                    rtm_tca_policy, extack);
+       if (err < 0)
+               return err;
+
+       dev = __dev_get_by_index(net, tcm->tcm_ifindex);
+       if (!dev)
+               return -ENODEV;
+
+       return __tc_get_qdisc(skb, n, extack, dev, tca, tcm);
+}
+
 static bool req_create_or_replace(struct nlmsghdr *n)
 {
        return (n->nlmsg_flags & NLM_F_CREATE &&
@@ -1601,35 +1613,19 @@ static bool req_change(struct nlmsghdr *n)
                !(n->nlmsg_flags & NLM_F_EXCL));
 }
 
-/*
- * Create/change qdisc.
- */
-static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
-                          struct netlink_ext_ack *extack)
+static int __tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
+                            struct netlink_ext_ack *extack,
+                            struct net_device *dev,
+                            struct nlattr *tca[TCA_MAX + 1],
+                            struct tcmsg *tcm,
+                            bool *replay)
 {
-       struct net *net = sock_net(skb->sk);
-       struct tcmsg *tcm;
-       struct nlattr *tca[TCA_MAX + 1];
-       struct net_device *dev;
+       struct Qdisc *q = NULL;
+       struct Qdisc *p = NULL;
        u32 clid;
-       struct Qdisc *q, *p;
        int err;
 
-replay:
-       /* Reinit, just in case something touches this. */
-       err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
-                                    rtm_tca_policy, extack);
-       if (err < 0)
-               return err;
-
-       tcm = nlmsg_data(n);
        clid = tcm->tcm_parent;
-       q = p = NULL;
-
-       dev = __dev_get_by_index(net, tcm->tcm_ifindex);
-       if (!dev)
-               return -ENODEV;
-
 
        if (clid) {
                if (clid != TC_H_ROOT) {
@@ -1755,7 +1751,7 @@ replay:
        }
        err = qdisc_change(q, tca, extack);
        if (err == 0)
-               qdisc_notify(net, skb, n, clid, NULL, q, extack);
+               qdisc_notify(sock_net(skb->sk), skb, n, clid, NULL, q, extack);
        return err;
 
 create_n_graft:
@@ -1788,8 +1784,10 @@ create_n_graft2:
                                 tca, &err, extack);
        }
        if (q == NULL) {
-               if (err == -EAGAIN)
-                       goto replay;
+               if (err == -EAGAIN) {
+                       *replay = true;
+                       return 0;
+               }
                return err;
        }
 
@@ -1804,6 +1802,39 @@ graft:
        return 0;
 }
 
+/*
+ * Create/change qdisc.
+ */
+static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
+                          struct netlink_ext_ack *extack)
+{
+       struct net *net = sock_net(skb->sk);
+       struct nlattr *tca[TCA_MAX + 1];
+       struct net_device *dev;
+       struct tcmsg *tcm;
+       bool replay;
+       int err;
+
+replay:
+       /* Reinit, just in case something touches this. */
+       err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
+                                    rtm_tca_policy, extack);
+       if (err < 0)
+               return err;
+
+       tcm = nlmsg_data(n);
+       dev = __dev_get_by_index(net, tcm->tcm_ifindex);
+       if (!dev)
+               return -ENODEV;
+
+       replay = false;
+       err = __tc_modify_qdisc(skb, n, extack, dev, tca, tcm, &replay);
+       if (replay)
+               goto replay;
+
+       return err;
+}
+
 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
                              struct netlink_callback *cb,
                              int *q_idx_p, int s_q_idx, bool recur,
@@ -2135,15 +2166,15 @@ static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
 
 #endif
 
-static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
-                        struct netlink_ext_ack *extack)
+static int __tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
+                          struct netlink_ext_ack *extack,
+                          struct net_device *dev,
+                          struct nlattr *tca[TCA_MAX + 1],
+                          struct tcmsg *tcm)
 {
        struct net *net = sock_net(skb->sk);
-       struct tcmsg *tcm = nlmsg_data(n);
-       struct nlattr *tca[TCA_MAX + 1];
-       struct net_device *dev;
-       struct Qdisc *q = NULL;
        const struct Qdisc_class_ops *cops;
+       struct Qdisc *q = NULL;
        unsigned long cl = 0;
        unsigned long new_cl;
        u32 portid;
@@ -2151,15 +2182,6 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
        u32 qid;
        int err;
 
-       err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
-                                    rtm_tca_policy, extack);
-       if (err < 0)
-               return err;
-
-       dev = __dev_get_by_index(net, tcm->tcm_ifindex);
-       if (!dev)
-               return -ENODEV;
-
        /*
           parent == TC_H_UNSPEC - unspecified parent.
           parent == TC_H_ROOT   - class is root, which has no parent.
@@ -2268,6 +2290,27 @@ out:
        return err;
 }
 
+static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
+                        struct netlink_ext_ack *extack)
+{
+       struct net *net = sock_net(skb->sk);
+       struct tcmsg *tcm = nlmsg_data(n);
+       struct nlattr *tca[TCA_MAX + 1];
+       struct net_device *dev;
+       int err;
+
+       err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
+                                    rtm_tca_policy, extack);
+       if (err < 0)
+               return err;
+
+       dev = __dev_get_by_index(net, tcm->tcm_ifindex);
+       if (!dev)
+               return -ENODEV;
+
+       return __tc_ctl_tclass(skb, n, extack, dev, tca, tcm);
+}
+
 struct qdisc_dump_args {
        struct qdisc_walker     w;
        struct sk_buff          *skb;
@@ -2344,20 +2387,12 @@ static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
        return 0;
 }
 
-static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
+static int __tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb,
+                           struct tcmsg *tcm, struct net_device *dev)
 {
-       struct tcmsg *tcm = nlmsg_data(cb->nlh);
-       struct net *net = sock_net(skb->sk);
        struct netdev_queue *dev_queue;
-       struct net_device *dev;
        int t, s_t;
 
-       if (nlmsg_len(cb->nlh) < sizeof(*tcm))
-               return 0;
-       dev = dev_get_by_index(net, tcm->tcm_ifindex);
-       if (!dev)
-               return 0;
-
        s_t = cb->args[0];
        t = 0;
 
@@ -2374,10 +2409,30 @@ static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
 done:
        cb->args[0] = t;
 
-       dev_put(dev);
        return skb->len;
 }
 
+static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       struct tcmsg *tcm = nlmsg_data(cb->nlh);
+       struct net *net = sock_net(skb->sk);
+       struct net_device *dev;
+       int err;
+
+       if (nlmsg_len(cb->nlh) < sizeof(*tcm))
+               return 0;
+
+       dev = dev_get_by_index(net, tcm->tcm_ifindex);
+       if (!dev)
+               return 0;
+
+       err = __tc_dump_tclass(skb, cb, tcm, dev);
+
+       dev_put(dev);
+
+       return err;
+}
+
 #ifdef CONFIG_PROC_FS
 static int psched_show(struct seq_file *seq, void *v)
 {