Re: [BUG] net_cls: Panic occured when net_cls subsystem use
From: Jarek Poplawski <hidden>
Date: 2009-06-02 21:11:03
On Tue, Jun 02, 2009 at 09:16:27AM -0400, jamal wrote: ...
Thanks for the courtesy. I note Dave already swallowed Minoru's patch; so lets move from there. Yes, there's a possibility of a regression - I (and so are you) are only recently evolved humans; we are not perfect... yet ;-> So i would agree with Minoru testing your patch as plan B in case the applied one starts causing trouble. BTW, ok - here's a quick untested, uncompiled fix to the u32 classifier to fix the first rock (which you already worked around in your changes to the included patch). No rush to submit for now..
Thanks for your courtesy as well. Alas, I'm not sure I can fully understand the current patch. You seem to redefine the ->get() method usage, so it looks for handle only for configured tp's. It might be right but I need more time to check this.
On the second rock you threw so violently, after some reflection, I think it is ok to send a replace twice with different priorities. The second one will be added and the old not deleted, but if the user has chosen the correct priority, then things will work out just fine. And if they want they have to explicitly delete the one they dont want. It is also not illegal to do a "replace" for installing instead of "add". So the only other things left to do from this exercise are (no rush in any of them): a) remove all "buckets" from underneath other classifiers b) get consistency across all classifiers in usage of setup API If you want to do this - go ahead; else i plan on tackling it probably when stable 2.6.31 kicks in.
I definitely prefer you doing this and me asking "rude" questions.;-) Cheers, Jarek P.
quoted hunk ↗ jump to hunk
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 07372f6..5ad0b98 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c@@ -249,6 +249,9 @@ static unsigned long u32_get(struct tcf_proto *tp, u32 handle) struct tc_u_hnode *ht; struct tc_u_common *tp_c = tp->data; + if (!tp_c) + return 0; + if (TC_U32_HTID(handle) == TC_U32_ROOT) ht = tp->root; else@@ -311,7 +314,6 @@ static int u32_init(struct tcf_proto *tp) root_ht->tp_c = tp_c; tp->root = root_ht; - tp->data = tp_c; return 0; }@@ -524,7 +526,7 @@ static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle, struct nlattr **tca, unsigned long *arg) { - struct tc_u_common *tp_c = tp->data; + struct tc_u_common *tp_c = tp->root->tp_c; struct tc_u_hnode *ht; struct tc_u_knode *n; struct tc_u32_sel *s;@@ -540,6 +542,7 @@ static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle, if (err < 0) return err; + tp->data = tp_c; if ((n = (struct tc_u_knode*)*arg) != NULL) { if (TC_U32_KEY(n->handle) == 0) return -EINVAL;