Andrew Lukoshko
b3393f484c
Drop the 211.7.x security-ahead patches superseded by the RHEL 211.8.1..211.16.1 backports (1100-1104), add those backports (1106-1161) from centos-stream-10 and upstream linux-6.12.y. Keep the smb cifs.spnego ahead-fix (1105). Bump to 211.16.1.
90 lines
2.8 KiB
Diff
90 lines
2.8 KiB
Diff
From ff57186b2cc39766672c4c0332323933e5faaa88 Mon Sep 17 00:00:00 2001
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From: William Liu <will@willsroot.io>
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Date: Tue, 19 Aug 2025 03:36:28 +0000
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Subject: [PATCH] net/sched: Make cake_enqueue return NET_XMIT_CN when past
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buffer_limit
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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[ Upstream commit 15de71d06a400f7fdc15bf377a2552b0ec437cf5 ]
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The following setup can trigger a WARNING in htb_activate due to
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the condition: !cl->leaf.q->q.qlen
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tc qdisc del dev lo root
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tc qdisc add dev lo root handle 1: htb default 1
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tc class add dev lo parent 1: classid 1:1 \
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htb rate 64bit
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tc qdisc add dev lo parent 1:1 handle f: \
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cake memlimit 1b
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ping -I lo -f -c1 -s64 -W0.001 127.0.0.1
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This is because the low memlimit leads to a low buffer_limit, which
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causes packet dropping. However, cake_enqueue still returns
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NET_XMIT_SUCCESS, causing htb_enqueue to call htb_activate with an
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empty child qdisc. We should return NET_XMIT_CN when packets are
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dropped from the same tin and flow.
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I do not believe return value of NET_XMIT_CN is necessary for packet
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drops in the case of ack filtering, as that is meant to optimize
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performance, not to signal congestion.
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Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
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Signed-off-by: William Liu <will@willsroot.io>
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Reviewed-by: Savino Dicanosa <savy@syst3mfailure.io>
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Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
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Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
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Link: https://patch.msgid.link/20250819033601.579821-1-will@willsroot.io
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Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Signed-off-by: Sasha Levin <sashal@kernel.org>
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diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
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index 2c2e2a67f3b2..6cbe8a7a0e5c 100644
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--- a/net/sched/sch_cake.c
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+++ b/net/sched/sch_cake.c
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@@ -1745,7 +1745,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
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ktime_t now = ktime_get();
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struct cake_tin_data *b;
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struct cake_flow *flow;
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- u32 idx;
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+ u32 idx, tin;
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/* choose flow to insert into */
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idx = cake_classify(sch, &b, skb, q->flow_mode, &ret);
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@@ -1755,6 +1755,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
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__qdisc_drop(skb, to_free);
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return ret;
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}
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+ tin = (u32)(b - q->tins);
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idx--;
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flow = &b->flows[idx];
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@@ -1922,13 +1923,22 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
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q->buffer_max_used = q->buffer_used;
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if (q->buffer_used > q->buffer_limit) {
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+ bool same_flow = false;
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u32 dropped = 0;
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+ u32 drop_id;
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while (q->buffer_used > q->buffer_limit) {
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dropped++;
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- cake_drop(sch, to_free);
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+ drop_id = cake_drop(sch, to_free);
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+
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+ if ((drop_id >> 16) == tin &&
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+ (drop_id & 0xFFFF) == idx)
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+ same_flow = true;
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}
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b->drop_overlimit += dropped;
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+
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+ if (same_flow)
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+ return NET_XMIT_CN;
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}
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return NET_XMIT_SUCCESS;
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}
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--
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2.50.1 (Apple Git-155)
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