net: convert some netlink netdev iterators to depend on the xarray

Reap the benefits of easier iteration thanks to the xarray.
Convert just the genetlink ones, those are easier to test.

Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230726185530.2247698-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 32a4cdf37dd470fea5914c51bd6415429b592bd0..84c36a7f873fd97b1a5cfa5cf1eebebd2ea50f45 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3016,6 +3016,9 @@ extern rwlock_t                           dev_base_lock;          /* Device list lock */
                        if (netdev_master_upper_dev_get_rcu(slave) == (bond))
 #define net_device_entry(lh)   list_entry(lh, struct net_device, dev_list)
 
+#define for_each_netdev_dump(net, d, ifindex)                          \
+       xa_for_each_start(&(net)->dev_by_index, (ifindex), (d), (ifindex))
+
 static inline struct net_device *next_net_device(struct net_device *dev)
 {
        struct list_head *lh;

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 65ef4867fc495b44b3eec63783a63b4359d1b9a2..797c813c7c77bcf3ec80f872bca7985cc9aa55b2 100644 (file)
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -101,43 +101,22 @@ int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 {
        struct net *net = sock_net(skb->sk);
        struct net_device *netdev;
-       int idx = 0, s_idx;
-       int h, s_h;
-       int err;
-
-       s_h = cb->args[0];
-       s_idx = cb->args[1];
+       int err = 0;
 
        rtnl_lock();
-
-       for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
-               struct hlist_head *head;
-
-               idx = 0;
-               head = &net->dev_index_head[h];
-               hlist_for_each_entry(netdev, head, index_hlist) {
-                       if (idx < s_idx)
-                               goto cont;
-                       err = netdev_nl_dev_fill(netdev, skb,
-                                                NETLINK_CB(cb->skb).portid,
-                                                cb->nlh->nlmsg_seq, 0,
-                                                NETDEV_CMD_DEV_GET);
-                       if (err < 0)
-                               break;
-cont:
-                       idx++;
-               }
+       for_each_netdev_dump(net, netdev, cb->args[0]) {
+               err = netdev_nl_dev_fill(netdev, skb,
+                                        NETLINK_CB(cb->skb).portid,
+                                        cb->nlh->nlmsg_seq, 0,
+                                        NETDEV_CMD_DEV_GET);
+               if (err < 0)
+                       break;
        }
-
        rtnl_unlock();
 
        if (err != -EMSGSIZE)
                return err;
 
-       cb->args[1] = idx;
-       cb->args[0] = h;
-       cb->seq = net->dev_base_seq;
-
        return skb->len;
 }
 

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 39a459b0111b4e0c4d1b6960a1f8af1371b409a6..ae344f1b0bbd1b0592e2756da90bdd3fff53a5f7 100644 (file)
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -252,8 +252,7 @@ int ethnl_multicast(struct sk_buff *skb, struct net_device *dev)
  * @ops:        request ops of currently processed message type
  * @req_info:   parsed request header of processed request
  * @reply_data: data needed to compose the reply
- * @pos_hash:   saved iteration position - hashbucket
- * @pos_idx:    saved iteration position - index
+ * @pos_ifindex: saved iteration position - ifindex
  *
  * These parameters are kept in struct netlink_callback as context preserved
  * between iterations. They are initialized by ethnl_default_start() and used
@@ -263,8 +262,7 @@ struct ethnl_dump_ctx {
        const struct ethnl_request_ops  *ops;
        struct ethnl_req_info           *req_info;
        struct ethnl_reply_data         *reply_data;
-       int                             pos_hash;
-       int                             pos_idx;
+       unsigned long                   pos_ifindex;
 };
 
 static const struct ethnl_request_ops *
@@ -490,55 +488,27 @@ static int ethnl_default_dumpit(struct sk_buff *skb,
 {
        struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
        struct net *net = sock_net(skb->sk);
-       int s_idx = ctx->pos_idx;
-       int h, idx = 0;
+       struct net_device *dev;
        int ret = 0;
 
        rtnl_lock();
-       for (h = ctx->pos_hash; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
-               struct hlist_head *head;
-               struct net_device *dev;
-               unsigned int seq;
-
-               head = &net->dev_index_head[h];
-
-restart_chain:
-               seq = net->dev_base_seq;
-               cb->seq = seq;
-               idx = 0;
-               hlist_for_each_entry(dev, head, index_hlist) {
-                       if (idx < s_idx)
-                               goto cont;
-                       dev_hold(dev);
-                       rtnl_unlock();
-
-                       ret = ethnl_default_dump_one(skb, dev, ctx, cb);
-                       dev_put(dev);
-                       if (ret < 0) {
-                               if (ret == -EOPNOTSUPP)
-                                       goto lock_and_cont;
-                               if (likely(skb->len))
-                                       ret = skb->len;
-                               goto out;
-                       }
-lock_and_cont:
-                       rtnl_lock();
-                       if (net->dev_base_seq != seq) {
-                               s_idx = idx + 1;
-                               goto restart_chain;
-                       }
-cont:
-                       idx++;
-               }
+       for_each_netdev_dump(net, dev, ctx->pos_ifindex) {
+               dev_hold(dev);
+               rtnl_unlock();
+
+               ret = ethnl_default_dump_one(skb, dev, ctx, cb);
+
+               rtnl_lock();
+               dev_put(dev);
 
+               if (ret < 0 && ret != -EOPNOTSUPP) {
+                       if (likely(skb->len))
+                               ret = skb->len;
+                       break;
+               }
        }
        rtnl_unlock();
 
-out:
-       ctx->pos_hash = h;
-       ctx->pos_idx = idx;
-       nl_dump_check_consistent(cb, nlmsg_hdr(skb));
-
        return ret;
 }
 
@@ -584,8 +554,7 @@ static int ethnl_default_start(struct netlink_callback *cb)
        ctx->ops = ops;
        ctx->req_info = req_info;
        ctx->reply_data = reply_data;
-       ctx->pos_hash = 0;
-       ctx->pos_idx = 0;
+       ctx->pos_ifindex = 0;
 
        return 0;
 

diff --git a/net/ethtool/tunnels.c b/net/ethtool/tunnels.c
index 67fb414ca859b75b5a0c9f2cd20a1f4a4045f5be..05f752557b5e02f144fe33d632499214e77fb72d 100644 (file)
--- a/net/ethtool/tunnels.c
+++ b/net/ethtool/tunnels.c
@@ -212,8 +212,7 @@ err_unlock_rtnl:
 
 struct ethnl_tunnel_info_dump_ctx {
        struct ethnl_req_info   req_info;
-       int                     pos_hash;
-       int                     pos_idx;
+       unsigned long           ifindex;
 };
 
 int ethnl_tunnel_info_start(struct netlink_callback *cb)
@@ -243,57 +242,39 @@ int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 {
        struct ethnl_tunnel_info_dump_ctx *ctx = (void *)cb->ctx;
        struct net *net = sock_net(skb->sk);
-       int s_idx = ctx->pos_idx;
-       int h, idx = 0;
+       struct net_device *dev;
        int ret = 0;
        void *ehdr;
 
        rtnl_lock();
-       cb->seq = net->dev_base_seq;
-       for (h = ctx->pos_hash; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
-               struct hlist_head *head;
-               struct net_device *dev;
-
-               head = &net->dev_index_head[h];
-               idx = 0;
-               hlist_for_each_entry(dev, head, index_hlist) {
-                       if (idx < s_idx)
-                               goto cont;
-
-                       ehdr = ethnl_dump_put(skb, cb,
-                                             ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY);
-                       if (!ehdr) {
-                               ret = -EMSGSIZE;
-                               goto out;
-                       }
-
-                       ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_TUNNEL_INFO_HEADER);
-                       if (ret < 0) {
-                               genlmsg_cancel(skb, ehdr);
-                               goto out;
-                       }
-
-                       ctx->req_info.dev = dev;
-                       ret = ethnl_tunnel_info_fill_reply(&ctx->req_info, skb);
-                       ctx->req_info.dev = NULL;
-                       if (ret < 0) {
-                               genlmsg_cancel(skb, ehdr);
-                               if (ret == -EOPNOTSUPP)
-                                       goto cont;
-                               goto out;
-                       }
-                       genlmsg_end(skb, ehdr);
-cont:
-                       idx++;
+       for_each_netdev_dump(net, dev, ctx->ifindex) {
+               ehdr = ethnl_dump_put(skb, cb,
+                                     ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY);
+               if (!ehdr) {
+                       ret = -EMSGSIZE;
+                       break;
                }
+
+               ret = ethnl_fill_reply_header(skb, dev,
+                                             ETHTOOL_A_TUNNEL_INFO_HEADER);
+               if (ret < 0) {
+                       genlmsg_cancel(skb, ehdr);
+                       break;
+               }
+
+               ctx->req_info.dev = dev;
+               ret = ethnl_tunnel_info_fill_reply(&ctx->req_info, skb);
+               ctx->req_info.dev = NULL;
+               if (ret < 0) {
+                       genlmsg_cancel(skb, ehdr);
+                       if (ret == -EOPNOTSUPP)
+                               continue;
+                       break;
+               }
+               genlmsg_end(skb, ehdr);
        }
-out:
        rtnl_unlock();
 
-       ctx->pos_hash = h;
-       ctx->pos_idx = idx;
-       nl_dump_check_consistent(cb, nlmsg_hdr(skb));
-
        if (ret == -EMSGSIZE && skb->len)
                return skb->len;
        return ret;