net sched: fix race in mirred device removal

This fixes hang when target device of mirred packet classifier action is removed. If a mirror or redirection action is configured to cause packets to go to another device, the classifier holds a ref count, but was assuming the adminstrator cleaned up all redirections before removing. The fix is to add a notifier and cleanup during unregister. The new list is implicitly protected by RTNL mutex because it is held during filter add/delete as well as notifier.

stephen hemminger committed 16 years ago

Commit 3b879561 parent 76ac21f2 files · +41 −3Browse files

Showing the changes to include/net (1 of 2 files). Show all

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include/net/tc_act/tc_mirred.h+1−0

@@ -9,6 +9,7 @@ struct tcf_mirred { · 8 unmodified lines
9	9	int tcfm_ifindex;
10	10	int tcfm_ok_push;
11	11	struct net_device *tcfm_dev;
	12	+ struct list_head tcfm_list;
12	13	};
13	14	#define to_mirred(pc) \
14	15	container_of(pc, struct tcf_mirred, common)