diff mbox series

[net-next,3/4] ipv6: add (struct uncached_list)->quarantine list

Message ID 20220210214231.2420942-4-eric.dumazet@gmail.com (mailing list archive)
State Accepted
Commit ba55ef81637c61e52772bcd4e5fba10ec7190d2a
Delegated to: Netdev Maintainers
Headers show
Series ipv6: remove addrconf reliance on loopback | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/cc_maintainers warning 2 maintainers not CCed: dsahern@kernel.org yoshfuji@linux-ipv6.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch warning WARNING: Possible repeated word: 'can'
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet Feb. 10, 2022, 9:42 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

This is an optimization to keep the per-cpu lists as short as possible:

Whenever rt6_uncached_list_flush_dev() changes one rt6_info
matching the disappearing device, it can can transfer the object
to a quarantine list, waiting for a final rt6_uncached_list_del().

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv6/route.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 5fc1a1de9481c859adc332746ccfcf237db6541f..6690666c9b0e32e7e801ac481876ea4aa31e4ead 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -130,6 +130,7 @@  static struct fib6_info *rt6_get_route_info(struct net *net,
 struct uncached_list {
 	spinlock_t		lock;
 	struct list_head	head;
+	struct list_head	quarantine;
 };
 
 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
@@ -151,7 +152,7 @@  void rt6_uncached_list_del(struct rt6_info *rt)
 		struct uncached_list *ul = rt->rt6i_uncached_list;
 
 		spin_lock_bh(&ul->lock);
-		list_del(&rt->rt6i_uncached);
+		list_del_init(&rt->rt6i_uncached);
 		spin_unlock_bh(&ul->lock);
 	}
 }
@@ -162,16 +163,21 @@  static void rt6_uncached_list_flush_dev(struct net_device *dev)
 
 	for_each_possible_cpu(cpu) {
 		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
-		struct rt6_info *rt;
+		struct rt6_info *rt, *safe;
+
+		if (list_empty(&ul->head))
+			continue;
 
 		spin_lock_bh(&ul->lock);
-		list_for_each_entry(rt, &ul->head, rt6i_uncached) {
+		list_for_each_entry_safe(rt, safe, &ul->head, rt6i_uncached) {
 			struct inet6_dev *rt_idev = rt->rt6i_idev;
 			struct net_device *rt_dev = rt->dst.dev;
+			bool handled = false;
 
 			if (rt_idev->dev == dev) {
 				rt->rt6i_idev = in6_dev_get(blackhole_netdev);
 				in6_dev_put(rt_idev);
+				handled = true;
 			}
 
 			if (rt_dev == dev) {
@@ -179,7 +185,11 @@  static void rt6_uncached_list_flush_dev(struct net_device *dev)
 				dev_replace_track(rt_dev, blackhole_netdev,
 						  &rt->dst.dev_tracker,
 						  GFP_ATOMIC);
+				handled = true;
 			}
+			if (handled)
+				list_move(&rt->rt6i_uncached,
+					  &ul->quarantine);
 		}
 		spin_unlock_bh(&ul->lock);
 	}
@@ -6721,6 +6731,7 @@  int __init ip6_route_init(void)
 		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 
 		INIT_LIST_HEAD(&ul->head);
+		INIT_LIST_HEAD(&ul->quarantine);
 		spin_lock_init(&ul->lock);
 	}