[PATCH net 0/5] rxrpc: Miscellaneous fixes

[PATCH net 0/5] rxrpc: Miscellaneous fixes

[David Howells]

Here are some fixes for AF_RXRPC:

 (1) Fix listen() allowing preallocation to overrun the prealloc buffer.

 (2) Prevent resending the request if we've seen the reply starting to
     arrive.

 (3) Fix accidental sharing of ACK state between transmission and
     reception.

 (4) Ignore ACKs in which ack.previousPacket regresses.  This indicates the
     highest DATA number so far seen, so should not be seen to go
     backwards.

 (5) Fix the determination of when to generate an IDLE-type ACK,
     simplifying it so that we generate one if we have more than two DATA
     packets that aren't hard-acked (consumed) or soft-acked (in the rx
     buffer, but could be discarded and re-requested).

The patches are tagged here:

	git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
	rxrpc-fixes-20220521

and can also be found on the following branch:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-fixes

Tested-by: kafs-testing+fedora34_64checkkafs-build-495@auristor.com

Changes
=======
ver #2)
 - Rebased onto net/master
 - Dropped the IPv6 checksum patch as it's already upstream.

David

Link: https://lore.kernel.org/r/165306442115.34086.1818959430525328753.stgit@warthog.procyon.org.uk/ # v1
---
David Howells (5):
      rxrpc: Fix listen() setting the bar too high for the prealloc rings
      rxrpc: Don't try to resend the request if we're receiving the reply
      rxrpc: Fix overlapping ACK accounting
      rxrpc: Don't let ack.previousPacket regress
      rxrpc: Fix decision on when to generate an IDLE ACK


 include/trace/events/rxrpc.h |  2 +-
 net/rxrpc/ar-internal.h      | 13 +++++++------
 net/rxrpc/call_event.c       |  3 ++-
 net/rxrpc/input.c            | 31 ++++++++++++++++++++-----------
 net/rxrpc/output.c           | 20 ++++++++++++--------
 net/rxrpc/recvmsg.c          |  8 +++-----
 net/rxrpc/sysctl.c           |  4 ++--
 7 files changed, 47 insertions(+), 34 deletions(-)

[PATCH net 1/5] rxrpc: Fix listen() setting the bar too high for the prealloc rings

[David Howells]

AF_RXRPC's listen() handler lets you set the backlog up to 32 (if you bump
up the sysctl), but whilst the preallocation circular buffers have 32 slots
in them, one of them has to be a dead slot because we're using CIRC_CNT().

This means that listen(rxrpc_sock, 32) will cause an oops when the socket
is closed because rxrpc_service_prealloc_one() allocated one too many calls
and rxrpc_discard_prealloc() won't then be able to get rid of them because
it'll think the ring is empty.  rxrpc_release_calls_on_socket() then tries
to abort them, but oopses because call->peer isn't yet set.

Fix this by setting the maximum backlog to RXRPC_BACKLOG_MAX - 1 to match
the ring capacity.

 BUG: kernel NULL pointer dereference, address: 0000000000000086
 ...
 RIP: 0010:rxrpc_send_abort_packet+0x73/0x240 [rxrpc]
 Call Trace:
  <TASK>
  ? __wake_up_common_lock+0x7a/0x90
  ? rxrpc_notify_socket+0x8e/0x140 [rxrpc]
  ? rxrpc_abort_call+0x4c/0x60 [rxrpc]
  rxrpc_release_calls_on_socket+0x107/0x1a0 [rxrpc]
  rxrpc_release+0xc9/0x1c0 [rxrpc]
  __sock_release+0x37/0xa0
  sock_close+0x11/0x20
  __fput+0x89/0x240
  task_work_run+0x59/0x90
  do_exit+0x319/0xaa0

Fixes: 00e907127e6f ("rxrpc: Preallocate peers, conns and calls for incoming service requests")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Link: https://lists.infradead.org/pipermail/linux-afs/2022-March/005079.html
---

 net/rxrpc/sysctl.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/rxrpc/sysctl.c b/net/rxrpc/sysctl.c
index 540351d6a5f4..555e0910786b 100644
--- a/net/rxrpc/sysctl.c
+++ b/net/rxrpc/sysctl.c
@@ -12,7 +12,7 @@
 
 static struct ctl_table_header *rxrpc_sysctl_reg_table;
 static const unsigned int four = 4;
-static const unsigned int thirtytwo = 32;
+static const unsigned int max_backlog = RXRPC_BACKLOG_MAX - 1;
 static const unsigned int n_65535 = 65535;
 static const unsigned int n_max_acks = RXRPC_RXTX_BUFF_SIZE - 1;
 static const unsigned long one_jiffy = 1;
@@ -89,7 +89,7 @@ static struct ctl_table rxrpc_sysctl_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= (void *)&four,
-		.extra2		= (void *)&thirtytwo,
+		.extra2		= (void *)&max_backlog,
 	},
 	{
 		.procname	= "rx_window_size",

[PATCH net 2/5] rxrpc: Don't try to resend the request if we're receiving the reply

[David Howells]

rxrpc has a timer to trigger resending of unacked data packets in a call.
This is not cancelled when a client call switches to the receive phase on
the basis that most calls don't last long enough for it to ever expire.
However, if it *does* expire after we've started to receive the reply, we
shouldn't then go into trying to retransmit or pinging the server to find
out if an ack got lost.

Fix this by skipping the resend code if we're into receiving the reply to a
client call.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
---

 net/rxrpc/call_event.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 22e05de5d1ca..31761084a76f 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -406,7 +406,8 @@ void rxrpc_process_call(struct work_struct *work)
 		goto recheck_state;
 	}
 
-	if (test_and_clear_bit(RXRPC_CALL_EV_RESEND, &call->events)) {
+	if (test_and_clear_bit(RXRPC_CALL_EV_RESEND, &call->events) &&
+	    call->state != RXRPC_CALL_CLIENT_RECV_REPLY) {
 		rxrpc_resend(call, now);
 		goto recheck_state;
 	}

[PATCH net 3/5] rxrpc: Fix overlapping ACK accounting

[David Howells]

Fix accidental overlapping of Rx-phase ACK accounting with Tx-phase ACK
accounting through variables shared between the two.  call->acks_* members
refer to ACKs received in the Tx phase and call->ackr_* members to ACKs
sent/to be sent during the Rx phase.

Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
---

 net/rxrpc/ar-internal.h |    7 ++++---
 net/rxrpc/input.c       |   16 ++++++++--------
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 969e532f77a9..9a9688c41d4d 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -676,10 +676,9 @@ struct rxrpc_call {
 
 	spinlock_t		input_lock;	/* Lock for packet input to this call */
 
-	/* receive-phase ACK management */
+	/* Receive-phase ACK management (ACKs we send). */
 	u8			ackr_reason;	/* reason to ACK */
 	rxrpc_serial_t		ackr_serial;	/* serial of packet being ACK'd */
-	rxrpc_serial_t		ackr_first_seq;	/* first sequence number received */
 	rxrpc_seq_t		ackr_prev_seq;	/* previous sequence number received */
 	rxrpc_seq_t		ackr_consumed;	/* Highest packet shown consumed */
 	rxrpc_seq_t		ackr_seen;	/* Highest packet shown seen */
@@ -692,8 +691,10 @@ struct rxrpc_call {
 #define RXRPC_CALL_RTT_AVAIL_MASK	0xf
 #define RXRPC_CALL_RTT_PEND_SHIFT	8
 
-	/* transmission-phase ACK management */
+	/* Transmission-phase ACK management (ACKs we've received). */
 	ktime_t			acks_latest_ts;	/* Timestamp of latest ACK received */
+	rxrpc_seq_t		acks_first_seq;	/* first sequence number received */
+	rxrpc_seq_t		acks_prev_seq;	/* previous sequence number received */
 	rxrpc_seq_t		acks_lowest_nak; /* Lowest NACK in the buffer (or ==tx_hard_ack) */
 	rxrpc_seq_t		acks_lost_top;	/* tx_top at the time lost-ack ping sent */
 	rxrpc_serial_t		acks_lost_ping;	/* Serial number of probe ACK */
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index dc201363f2c4..f11673cda217 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -812,7 +812,7 @@ static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
 static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
 			       rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt)
 {
-	rxrpc_seq_t base = READ_ONCE(call->ackr_first_seq);
+	rxrpc_seq_t base = READ_ONCE(call->acks_first_seq);
 
 	if (after(first_pkt, base))
 		return true; /* The window advanced */
@@ -820,7 +820,7 @@ static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
 	if (before(first_pkt, base))
 		return false; /* firstPacket regressed */
 
-	if (after_eq(prev_pkt, call->ackr_prev_seq))
+	if (after_eq(prev_pkt, call->acks_prev_seq))
 		return true; /* previousPacket hasn't regressed. */
 
 	/* Some rx implementations put a serial number in previousPacket. */
@@ -906,8 +906,8 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	/* Discard any out-of-order or duplicate ACKs (outside lock). */
 	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
 		trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
-					   first_soft_ack, call->ackr_first_seq,
-					   prev_pkt, call->ackr_prev_seq);
+					   first_soft_ack, call->acks_first_seq,
+					   prev_pkt, call->acks_prev_seq);
 		return;
 	}
 
@@ -922,14 +922,14 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	/* Discard any out-of-order or duplicate ACKs (inside lock). */
 	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
 		trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
-					   first_soft_ack, call->ackr_first_seq,
-					   prev_pkt, call->ackr_prev_seq);
+					   first_soft_ack, call->acks_first_seq,
+					   prev_pkt, call->acks_prev_seq);
 		goto out;
 	}
 	call->acks_latest_ts = skb->tstamp;
 
-	call->ackr_first_seq = first_soft_ack;
-	call->ackr_prev_seq = prev_pkt;
+	call->acks_first_seq = first_soft_ack;
+	call->acks_prev_seq = prev_pkt;
 
 	/* Parse rwind and mtu sizes if provided. */
 	if (buf.info.rxMTU)

[PATCH net 4/5] rxrpc: Don't let ack.previousPacket regress

[David Howells]

The previousPacket field in the rx ACK packet should never go backwards -
it's now the highest DATA sequence number received, not the last on
received (it used to be used for out of sequence detection).

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
---

 net/rxrpc/ar-internal.h |    4 ++--
 net/rxrpc/input.c       |    4 +++-
 net/rxrpc/output.c      |    2 +-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 9a9688c41d4d..8465985a4cb6 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -679,7 +679,7 @@ struct rxrpc_call {
 	/* Receive-phase ACK management (ACKs we send). */
 	u8			ackr_reason;	/* reason to ACK */
 	rxrpc_serial_t		ackr_serial;	/* serial of packet being ACK'd */
-	rxrpc_seq_t		ackr_prev_seq;	/* previous sequence number received */
+	rxrpc_seq_t		ackr_highest_seq; /* Higest sequence number received */
 	rxrpc_seq_t		ackr_consumed;	/* Highest packet shown consumed */
 	rxrpc_seq_t		ackr_seen;	/* Highest packet shown seen */
 
@@ -694,7 +694,7 @@ struct rxrpc_call {
 	/* Transmission-phase ACK management (ACKs we've received). */
 	ktime_t			acks_latest_ts;	/* Timestamp of latest ACK received */
 	rxrpc_seq_t		acks_first_seq;	/* first sequence number received */
-	rxrpc_seq_t		acks_prev_seq;	/* previous sequence number received */
+	rxrpc_seq_t		acks_prev_seq;	/* Highest previousPacket received */
 	rxrpc_seq_t		acks_lowest_nak; /* Lowest NACK in the buffer (or ==tx_hard_ack) */
 	rxrpc_seq_t		acks_lost_top;	/* tx_top at the time lost-ack ping sent */
 	rxrpc_serial_t		acks_lost_ping;	/* Serial number of probe ACK */
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index f11673cda217..2e61545ad8ca 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -453,7 +453,6 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 	    !rxrpc_receiving_reply(call))
 		goto unlock;
 
-	call->ackr_prev_seq = seq0;
 	hard_ack = READ_ONCE(call->rx_hard_ack);
 
 	nr_subpackets = sp->nr_subpackets;
@@ -534,6 +533,9 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 			ack_serial = serial;
 		}
 
+		if (after(seq0, call->ackr_highest_seq))
+			call->ackr_highest_seq = seq0;
+
 		/* Queue the packet.  We use a couple of memory barriers here as need
 		 * to make sure that rx_top is perceived to be set after the buffer
 		 * pointer and that the buffer pointer is set after the annotation and
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index a45c83f22236..46aae9b7006f 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -89,7 +89,7 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
 	pkt->ack.bufferSpace	= htons(8);
 	pkt->ack.maxSkew	= htons(0);
 	pkt->ack.firstPacket	= htonl(hard_ack + 1);
-	pkt->ack.previousPacket	= htonl(call->ackr_prev_seq);
+	pkt->ack.previousPacket	= htonl(call->ackr_highest_seq);
 	pkt->ack.serial		= htonl(serial);
 	pkt->ack.reason		= reason;
 	pkt->ack.nAcks		= top - hard_ack;

[PATCH net 5/5] rxrpc: Fix decision on when to generate an IDLE ACK

[David Howells]

Fix the decision on when to generate an IDLE ACK by keeping a count of the
number of packets we've received, but not yet soft-ACK'd, and the number of
packets we've processed, but not yet hard-ACK'd, rather than trying to keep
track of which DATA sequence numbers correspond to those points.

We then generate an ACK when either counter exceeds 2.  The counters are
both cleared when we transcribe the information into any sort of ACK packet
for transmission.  IDLE and DELAY ACKs are skipped if both counters are 0
(ie. no change).

Fixes: 805b21b929e2 ("rxrpc: Send an ACK after every few DATA packets we receive")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
---

 include/trace/events/rxrpc.h |    2 +-
 net/rxrpc/ar-internal.h      |    4 ++--
 net/rxrpc/input.c            |   11 +++++++++--
 net/rxrpc/output.c           |   18 +++++++++++-------
 net/rxrpc/recvmsg.c          |    8 +++-----
 5 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 4a3ab0ed6e06..1c714336b863 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -1509,7 +1509,7 @@ TRACE_EVENT(rxrpc_call_reset,
 		    __entry->call_serial = call->rx_serial;
 		    __entry->conn_serial = call->conn->hi_serial;
 		    __entry->tx_seq = call->tx_hard_ack;
-		    __entry->rx_seq = call->ackr_seen;
+		    __entry->rx_seq = call->rx_hard_ack;
 			   ),
 
 	    TP_printk("c=%08x %08x:%08x r=%08x/%08x tx=%08x rx=%08x",
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 8465985a4cb6..dce056adb78c 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -680,8 +680,8 @@ struct rxrpc_call {
 	u8			ackr_reason;	/* reason to ACK */
 	rxrpc_serial_t		ackr_serial;	/* serial of packet being ACK'd */
 	rxrpc_seq_t		ackr_highest_seq; /* Higest sequence number received */
-	rxrpc_seq_t		ackr_consumed;	/* Highest packet shown consumed */
-	rxrpc_seq_t		ackr_seen;	/* Highest packet shown seen */
+	atomic_t		ackr_nr_unacked; /* Number of unacked packets */
+	atomic_t		ackr_nr_consumed; /* Number of packets needing hard ACK */
 
 	/* RTT management */
 	rxrpc_serial_t		rtt_serial[4];	/* Serial number of DATA or PING sent */
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 2e61545ad8ca..1145cb14d86f 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -412,8 +412,8 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	enum rxrpc_call_state state;
-	unsigned int j, nr_subpackets;
-	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
+	unsigned int j, nr_subpackets, nr_unacked = 0;
+	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = serial;
 	rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack;
 	bool immediate_ack = false, jumbo_bad = false;
 	u8 ack = 0;
@@ -569,6 +569,8 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 			sp = NULL;
 		}
 
+		nr_unacked++;
+
 		if (last) {
 			set_bit(RXRPC_CALL_RX_LAST, &call->flags);
 			if (!ack) {
@@ -588,9 +590,14 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 			}
 			call->rx_expect_next = seq + 1;
 		}
+		if (!ack)
+			ack_serial = serial;
 	}
 
 ack:
+	if (atomic_add_return(nr_unacked, &call->ackr_nr_unacked) > 2 && !ack)
+		ack = RXRPC_ACK_IDLE;
+
 	if (ack)
 		rxrpc_propose_ACK(call, ack, ack_serial,
 				  immediate_ack, true,
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 46aae9b7006f..9683617db704 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -74,11 +74,18 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
 				 u8 reason)
 {
 	rxrpc_serial_t serial;
+	unsigned int tmp;
 	rxrpc_seq_t hard_ack, top, seq;
 	int ix;
 	u32 mtu, jmax;
 	u8 *ackp = pkt->acks;
 
+	tmp = atomic_xchg(&call->ackr_nr_unacked, 0);
+	tmp |= atomic_xchg(&call->ackr_nr_consumed, 0);
+	if (!tmp && (reason == RXRPC_ACK_DELAY ||
+		     reason == RXRPC_ACK_IDLE))
+		return 0;
+
 	/* Barrier against rxrpc_input_data(). */
 	serial = call->ackr_serial;
 	hard_ack = READ_ONCE(call->rx_hard_ack);
@@ -223,6 +230,10 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
 	n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
 
 	spin_unlock_bh(&call->lock);
+	if (n == 0) {
+		kfree(pkt);
+		return 0;
+	}
 
 	iov[0].iov_base	= pkt;
 	iov[0].iov_len	= sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
@@ -259,13 +270,6 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
 					  ntohl(pkt->ack.serial),
 					  false, true,
 					  rxrpc_propose_ack_retry_tx);
-		} else {
-			spin_lock_bh(&call->lock);
-			if (after(hard_ack, call->ackr_consumed))
-				call->ackr_consumed = hard_ack;
-			if (after(top, call->ackr_seen))
-				call->ackr_seen = top;
-			spin_unlock_bh(&call->lock);
 		}
 
 		rxrpc_set_keepalive(call);
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index eca6dda26c77..250f23bc1c07 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -260,11 +260,9 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
 		rxrpc_end_rx_phase(call, serial);
 	} else {
 		/* Check to see if there's an ACK that needs sending. */
-		if (after_eq(hard_ack, call->ackr_consumed + 2) ||
-		    after_eq(top, call->ackr_seen + 2) ||
-		    (hard_ack == top && after(hard_ack, call->ackr_consumed)))
-			rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial,
-					  true, true,
+		if (atomic_inc_return(&call->ackr_nr_consumed) > 2)
+			rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, serial,
+					  true, false,
 					  rxrpc_propose_ack_rotate_rx);
 		if (call->ackr_reason && call->ackr_reason != RXRPC_ACK_DELAY)
 			rxrpc_send_ack_packet(call, false, NULL);

Re: [PATCH net 0/5] rxrpc: Miscellaneous fixes

[David Miller]

From: David Howells <dhowells@redhat.com>
Date: Sat, 21 May 2022 09:02:58 +0100

> 
> Here are some fixes for AF_RXRPC:
> 
>  (1) Fix listen() allowing preallocation to overrun the prealloc buffer.
> 
>  (2) Prevent resending the request if we've seen the reply starting to
>      arrive.
> 
>  (3) Fix accidental sharing of ACK state between transmission and
>      reception.
> 
>  (4) Ignore ACKs in which ack.previousPacket regresses.  This indicates the
>      highest DATA number so far seen, so should not be seen to go
>      backwards.
> 
>  (5) Fix the determination of when to generate an IDLE-type ACK,
>      simplifying it so that we generate one if we have more than two DATA
>      packets that aren't hard-acked (consumed) or soft-acked (in the rx
>      buffer, but could be discarded and re-requested).
> 
> The patches are tagged here:
> 
> 	git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
> 	rxrpc-fixes-20220521
> 
> and can also be found on the following branch:
> 
> 	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-fixes

I tried to pull from this url and it does not work, just fyi...

So I applied the series instead.

> Tested-by: kafs-testing+fedora34_64checkkafs-build-495@auristor.com

Thank you.

Re: [PATCH net 0/5] rxrpc: Miscellaneous fixes

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Sat, 21 May 2022 09:02:58 +0100 you wrote:
> Here are some fixes for AF_RXRPC:
> 
>  (1) Fix listen() allowing preallocation to overrun the prealloc buffer.
> 
>  (2) Prevent resending the request if we've seen the reply starting to
>      arrive.
> 
> [...]

Here is the summary with links:
  - [net,1/5] rxrpc: Fix listen() setting the bar too high for the prealloc rings
    https://git.kernel.org/netdev/net/c/88e22159750b
  - [net,2/5] rxrpc: Don't try to resend the request if we're receiving the reply
    https://git.kernel.org/netdev/net/c/114af61f88fb
  - [net,3/5] rxrpc: Fix overlapping ACK accounting
    https://git.kernel.org/netdev/net/c/8940ba3cfe48
  - [net,4/5] rxrpc: Don't let ack.previousPacket regress
    https://git.kernel.org/netdev/net/c/81524b631253
  - [net,5/5] rxrpc: Fix decision on when to generate an IDLE ACK
    https://git.kernel.org/netdev/net/c/9a3dedcf1809

You are awesome, thank you!
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Deet-doot-dot, I am a bot.
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[PATCH net 0/5] rxrpc: Miscellaneous fixes

[David Howells]

Here some miscellaneous fixes for AF_RXRPC:

 (1) Fix the congestion control algorithm to start cwnd at 4 and to not cut
     ssthresh when the peer cuts its rwind size.

 (2) Only transmit a single ACK for all the DATA packets glued together
     into a jumbo packet to reduce the number of ACKs being generated.

 (3) Clean up the generation of flags in the protocol header when creating
     a packet for transmission.  This means we don't carry the old
     REQUEST-ACK bit around from previous transmissions, will make it
     easier to fix the MORE-PACKETS flag and make it easier to do jumbo
     packet assembly in future.

 (4) Fix how the MORE-PACKETS flag is driven.  We shouldn't be setting it
     in sendmsg() as the packet is then queued and the bit is left in that
     state, no matter how long it takes us to transmit the packet - and
     will still be in that state if the packet is retransmitted.

 (5) Request an ACK on an impending transmission stall due to the app layer
     not feeding us new data fast enough.  If we don't request an ACK, we
     may have to hold on to the packet buffers for a significant amount of
     time until the receiver gets bored and sends us an ACK anyway.

David

---
The patches can be found here also:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-fixes

David Howells (5):
  rxrpc: Fix congestion control algorithm
  rxrpc: Only transmit one ACK per jumbo packet received
  rxrpc: Clean up Tx header flags generation handling
  rxrpc: Change how the MORE-PACKETS rxrpc wire header flag is driven
  rxrpc: Request an ACK on impending Tx stall

 include/trace/events/rxrpc.h |  2 +-
 net/rxrpc/ar-internal.h      |  2 +-
 net/rxrpc/call_object.c      |  7 +-----
 net/rxrpc/input.c            | 49 +++++++++++++++++++++++++-----------
 net/rxrpc/output.c           | 26 ++++++++++++++-----
 net/rxrpc/proc.c             |  6 ++---
 net/rxrpc/sendmsg.c          |  3 ---
 7 files changed, 61 insertions(+), 34 deletions(-)

Re: [PATCH net 0/5] rxrpc: Miscellaneous fixes

[Jakub Kicinski]

On Fri,  3 May 2024 16:07:38 +0100 David Howells wrote:
> Here some miscellaneous fixes for AF_RXRPC:
> 
>  (1) Fix the congestion control algorithm to start cwnd at 4 and to not cut
>      ssthresh when the peer cuts its rwind size.
> 
>  (2) Only transmit a single ACK for all the DATA packets glued together
>      into a jumbo packet to reduce the number of ACKs being generated.
> 
>  (3) Clean up the generation of flags in the protocol header when creating
>      a packet for transmission.  This means we don't carry the old
>      REQUEST-ACK bit around from previous transmissions, will make it
>      easier to fix the MORE-PACKETS flag and make it easier to do jumbo
>      packet assembly in future.
> 
>  (4) Fix how the MORE-PACKETS flag is driven.  We shouldn't be setting it
>      in sendmsg() as the packet is then queued and the bit is left in that
>      state, no matter how long it takes us to transmit the packet - and
>      will still be in that state if the packet is retransmitted.
> 
>  (5) Request an ACK on an impending transmission stall due to the app layer
>      not feeding us new data fast enough.  If we don't request an ACK, we
>      may have to hold on to the packet buffers for a significant amount of
>      time until the receiver gets bored and sends us an ACK anyway.

Looks like these got marked as Rejected in patchwork.
I think either because lore is confused and attaches an exchange with
DaveM from 2022 to them (?) or because I mentioned to DaveM that I'm
not sure these are fixes. So let me ask - on a scale of 1 to 10, how
convinced are you that these should go to Linus this week rather than
being categorized as general improvements and go during the merge
window (without the Fixes tags)?

Re: [PATCH net 0/5] rxrpc: Miscellaneous fixes

[Jeffrey Altman]

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> On May 7, 2024, at 8:44 PM, Jakub Kicinski <kuba@kernel.org> wrote:
> 
> On Fri,  3 May 2024 16:07:38 +0100 David Howells wrote:
>> Here some miscellaneous fixes for AF_RXRPC:
>> 
>> (1) Fix the congestion control algorithm to start cwnd at 4 and to not cut
>>  ssthresh when the peer cuts its rwind size.
>> 
>> (2) Only transmit a single ACK for all the DATA packets glued together
>>  into a jumbo packet to reduce the number of ACKs being generated.
>> 
>> (3) Clean up the generation of flags in the protocol header when creating
>>  a packet for transmission.  This means we don't carry the old
>>  REQUEST-ACK bit around from previous transmissions, will make it
>>  easier to fix the MORE-PACKETS flag and make it easier to do jumbo
>>  packet assembly in future.
>> 
>> (4) Fix how the MORE-PACKETS flag is driven.  We shouldn't be setting it
>>  in sendmsg() as the packet is then queued and the bit is left in that
>>  state, no matter how long it takes us to transmit the packet - and
>>  will still be in that state if the packet is retransmitted.
>> 
>> (5) Request an ACK on an impending transmission stall due to the app layer
>>  not feeding us new data fast enough.  If we don't request an ACK, we
>>  may have to hold on to the packet buffers for a significant amount of
>>  time until the receiver gets bored and sends us an ACK anyway.
> 
> Looks like these got marked as Rejected in patchwork.
> I think either because lore is confused and attaches an exchange with
> DaveM from 2022 to them (?) or because I mentioned to DaveM that I'm
> not sure these are fixes. So let me ask - on a scale of 1 to 10, how
> convinced are you that these should go to Linus this week rather than
> being categorized as general improvements and go during the merge
> window (without the Fixes tags)?

Jakub,

In my opinion, the first two patches in the series I believe are important to back port to the stable branches.

Reviewed-by: Jeffrey Altman <jaltman@auristor.com <mailto:jaltman@auristor.com>>

Jeffrey




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Re: [PATCH net 0/5] rxrpc: Miscellaneous fixes

[Jakub Kicinski]

On Wed, 8 May 2024 01:57:43 -0600 Jeffrey Altman wrote:
> > Looks like these got marked as Rejected in patchwork.
> > I think either because lore is confused and attaches an exchange with
> > DaveM from 2022 to them (?) or because I mentioned to DaveM that I'm
> > not sure these are fixes. So let me ask - on a scale of 1 to 10, how
> > convinced are you that these should go to Linus this week rather than
> > being categorized as general improvements and go during the merge
> > window (without the Fixes tags)?  
> 
> Jakub,
> 
> In my opinion, the first two patches in the series I believe are important to back port to the stable branches.
> 
> Reviewed-by: Jeffrey Altman <jaltman@auristor.com <mailto:jaltman@auristor.com>>

Are they regressions? Seems possible from the Fixes tag but unclear
from the text of the commit messages.

In any case, taking the first two may be a reasonable compromise.
Does it sounds good to you, David?

Re: [PATCH net 0/5] rxrpc: Miscellaneous fixes

[David Howells]

Jakub Kicinski <kuba@kernel.org> wrote:

> Looks like these got marked as Rejected in patchwork.
> I think either because lore is confused and attaches an exchange with
> DaveM from 2022 to them (?) or because I mentioned to DaveM that I'm
> not sure these are fixes. So let me ask - on a scale of 1 to 10, how
> convinced are you that these should go to Linus this week rather than
> being categorized as general improvements and go during the merge
> window (without the Fixes tags)?

Ah, sorry.  I marked them rejected as I put myself as cc: not S-o-b on one of
them, but then got distracted and didn't get around to reposting them.  And
Jeff mentioned that the use of the MORE-PACKETS flag is not exactly
consistent between various implementations.

So if you could take just the first two for the moment?

Thanks,
David

Re: [PATCH net 0/5] rxrpc: Miscellaneous fixes

[Jakub Kicinski]

On Wed, 08 May 2024 15:00:28 +0100 David Howells wrote:
> Jakub Kicinski <kuba@kernel.org> wrote:
> 
> > Looks like these got marked as Rejected in patchwork.
> > I think either because lore is confused and attaches an exchange with
> > DaveM from 2022 to them (?) or because I mentioned to DaveM that I'm
> > not sure these are fixes. So let me ask - on a scale of 1 to 10, how
> > convinced are you that these should go to Linus this week rather than
> > being categorized as general improvements and go during the merge
> > window (without the Fixes tags)?  
> 
> Ah, sorry.  I marked them rejected as I put myself as cc: not S-o-b on one of
> them, but then got distracted and didn't get around to reposting them.  And
> Jeff mentioned that the use of the MORE-PACKETS flag is not exactly
> consistent between various implementations.

Ah, mystery solved :)

> So if you could take just the first two for the moment?

Done!

Re: [PATCH net 0/5] rxrpc: Miscellaneous fixes

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri,  3 May 2024 16:07:38 +0100 you wrote:
> Here some miscellaneous fixes for AF_RXRPC:
> 
>  (1) Fix the congestion control algorithm to start cwnd at 4 and to not cut
>      ssthresh when the peer cuts its rwind size.
> 
>  (2) Only transmit a single ACK for all the DATA packets glued together
>      into a jumbo packet to reduce the number of ACKs being generated.
> 
> [...]

Here is the summary with links:
  - [net,1/5] rxrpc: Fix congestion control algorithm
    https://git.kernel.org/netdev/net/c/ba4e103848d3
  - [net,2/5] rxrpc: Only transmit one ACK per jumbo packet received
    https://git.kernel.org/netdev/net/c/012b7206918d
  - [net,3/5] rxrpc: Clean up Tx header flags generation handling
    (no matching commit)
  - [net,4/5] rxrpc: Change how the MORE-PACKETS rxrpc wire header flag is driven
    (no matching commit)
  - [net,5/5] rxrpc: Request an ACK on impending Tx stall
    (no matching commit)

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html