From bb047ddd145860ff24820320a21f03cf8c071b22 Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Tue, 13 Feb 2018 12:00:16 +0100 Subject: net: sched: don't set q pointer for shared blocks It is pointless to set block->q for block which are shared among multiple qdiscs. So remove the assignment in that case. Do a bit of code reshuffle to make block->index initialized at that point so we can use tcf_block_shared() helper. Reported-by: Cong Wang Fixes: 4861738775d7 ("net: sched: introduce shared filter blocks infrastructure") Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- net/sched/cls_api.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) (limited to 'net/sched/cls_api.c') diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 2bc1bc23d42e..a7dc7271042a 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -376,17 +376,12 @@ struct tcf_net { static unsigned int tcf_net_id; static int tcf_block_insert(struct tcf_block *block, struct net *net, - u32 block_index, struct netlink_ext_ack *extack) + struct netlink_ext_ack *extack) { struct tcf_net *tn = net_generic(net, tcf_net_id); - int err; - err = idr_alloc_u32(&tn->idr, block, &block_index, block_index, - GFP_KERNEL); - if (err) - return err; - block->index = block_index; - return 0; + return idr_alloc_u32(&tn->idr, block, &block->index, block->index, + GFP_KERNEL); } static void tcf_block_remove(struct tcf_block *block, struct net *net) @@ -397,6 +392,7 @@ static void tcf_block_remove(struct tcf_block *block, struct net *net) } static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q, + u32 block_index, struct netlink_ext_ack *extack) { struct tcf_block *block; @@ -419,10 +415,13 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q, err = -ENOMEM; goto err_chain_create; } - block->net = qdisc_net(q); block->refcnt = 1; block->net = net; - block->q = q; + block->index = block_index; + + /* Don't store q pointer for blocks which are shared */ + if (!tcf_block_shared(block)) + block->q = q; return block; err_chain_create: @@ -518,13 +517,12 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q, } if (!block) { - block = tcf_block_create(net, q, extack); + block = tcf_block_create(net, q, ei->block_index, extack); if (IS_ERR(block)) return PTR_ERR(block); created = true; - if (ei->block_index) { - err = tcf_block_insert(block, net, - ei->block_index, extack); + if (tcf_block_shared(block)) { + err = tcf_block_insert(block, net, extack); if (err) goto err_block_insert; } -- cgit v1.2.3 From 5ae437ad5a2ed573b1ebb04e0afa70b8869f88dd Mon Sep 17 00:00:00 2001 From: Roman Kapl Date: Mon, 19 Feb 2018 21:32:51 +0100 Subject: net: sched: report if filter is too large to dump So far, if the filter was too large to fit in the allocated skb, the kernel did not return any error and stopped dumping. Modify the dumper so that it returns -EMSGSIZE when a filter fails to dump and it is the first filter in the skb. If we are not first, we will get a next chance with more room. I understand this is pretty near to being an API change, but the original design (silent truncation) can be considered a bug. Note: The error case can happen pretty easily if you create a filter with 32 actions and have 4kb pages. Also recent versions of iproute try to be clever with their buffer allocation size, which in turn leads to Signed-off-by: Roman Kapl Acked-by: Jiri Pirko Acked-by: Cong Wang Signed-off-by: David S. Miller --- net/sched/cls_api.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'net/sched/cls_api.c') diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index a7dc7271042a..247b7cc20c13 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -1397,13 +1397,18 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) nla_get_u32(tca[TCA_CHAIN]) != chain->index) continue; if (!tcf_chain_dump(chain, q, parent, skb, cb, - index_start, &index)) + index_start, &index)) { + err = -EMSGSIZE; break; + } } cb->args[0] = index; out: + /* If we did no progress, the error (EMSGSIZE) is real */ + if (skb->len == 0 && err) + return err; return skb->len; } -- cgit v1.2.3