diff mbox series

[v2,net-next,04/14] ipv6: use xarray iterator to implement inet6_dump_ifinfo()

Message ID 20240222105021.1943116-5-edumazet@google.com (mailing list archive)
State Accepted
Commit ac14ad9755d4f8f286fd2cd710aa5dcf9a3c777a
Delegated to: Netdev Maintainers
Headers show
Series rtnetlink: reduce RTNL pressure for dumps | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 940 this patch: 940
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 957 this patch: 957
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 957 this patch: 957
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 69 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-02-23--03-00 (tests: 1457)

Commit Message

Eric Dumazet Feb. 22, 2024, 10:50 a.m. UTC 
Prepare inet6_dump_ifinfo() to run with RCU protection
instead of RTNL and use for_each_netdev_dump() interface.

Also properly return 0 at the end of a dump, avoiding
an extra recvmsg() system call and RTNL acquisition.

Note that RTNL-less dumps need core changes, coming later
in the series.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
---
 net/ipv6/addrconf.c | 46 +++++++++++++++++++--------------------------
 1 file changed, 19 insertions(+), 27 deletions(-)

Comments

Donald Hunter Feb. 23, 2024, 2:42 p.m. UTC | #1 
Eric Dumazet <edumazet@google.com> writes:

> Prepare inet6_dump_ifinfo() to run with RCU protection
> instead of RTNL and use for_each_netdev_dump() interface.
>
> Also properly return 0 at the end of a dump, avoiding
> an extra recvmsg() system call and RTNL acquisition.
>
> Note that RTNL-less dumps need core changes, coming later
> in the series.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reviewed-by: Ido Schimmel <idosch@nvidia.com>

Nice to see cleaner code with for_each_netdev_dump().

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
diff mbox series

Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index df3c6feea74e2d95144140eceb6df5cef2dce1f4..8994ddc6c859e6bc68303e6e61663baf330aee00 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -6117,50 +6117,42 @@  static int inet6_valid_dump_ifinfo(const struct nlmsghdr *nlh,
 static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct net *net = sock_net(skb->sk);
-	int h, s_h;
-	int idx = 0, s_idx;
+	struct {
+		unsigned long ifindex;
+	} *ctx = (void *)cb->ctx;
 	struct net_device *dev;
 	struct inet6_dev *idev;
-	struct hlist_head *head;
+	int err;
 
 	/* only requests using strict checking can pass data to
 	 * influence the dump
 	 */
 	if (cb->strict_check) {
-		int err = inet6_valid_dump_ifinfo(cb->nlh, cb->extack);
+		err = inet6_valid_dump_ifinfo(cb->nlh, cb->extack);
 
 		if (err < 0)
 			return err;
 	}
 
-	s_h = cb->args[0];
-	s_idx = cb->args[1];
-
+	err = 0;
 	rcu_read_lock();
-	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
-		idx = 0;
-		head = &net->dev_index_head[h];
-		hlist_for_each_entry_rcu(dev, head, index_hlist) {
-			if (idx < s_idx)
-				goto cont;
-			idev = __in6_dev_get(dev);
-			if (!idev)
-				goto cont;
-			if (inet6_fill_ifinfo(skb, idev,
-					      NETLINK_CB(cb->skb).portid,
-					      cb->nlh->nlmsg_seq,
-					      RTM_NEWLINK, NLM_F_MULTI) < 0)
-				goto out;
-cont:
-			idx++;
+	for_each_netdev_dump(net, dev, ctx->ifindex) {
+		idev = __in6_dev_get(dev);
+		if (!idev)
+			continue;
+		err = inet6_fill_ifinfo(skb, idev,
+					NETLINK_CB(cb->skb).portid,
+					cb->nlh->nlmsg_seq,
+					RTM_NEWLINK, NLM_F_MULTI);
+		if (err < 0) {
+			if (likely(skb->len))
+				err = skb->len;
+			break;
 		}
 	}
-out:
 	rcu_read_unlock();
-	cb->args[1] = idx;
-	cb->args[0] = h;
 
-	return skb->len;
+	return err;
 }
 
 void inet6_ifinfo_notify(int event, struct inet6_dev *idev)