linux.git/net/rxrpc, branch v6.9

rxrpc: Only transmit one ACK per jumbo packet received

2024-05-08T15:05:03+00:00

Only generate one ACK packet for all the subpackets in a jumbo packet.  If
we would like to generate more than one ACK, we prioritise them base on
their reason code, in the order, highest first:

   OutOfSeq > NoSpace > ExceedsWin > Duplicate > Requested > Delay > Idle

For the first four, we reference the lowest offending subpacket; for the
last three, the highest.

This reduces the number of ACKs we end up transmitting to one per UDP
packet transmitted to reduce network loading and packet parsing.

Fixes: 5d7edbc9231e ("rxrpc: Get rid of the Rx ring")
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Reviewed-by: Jeffrey Altman >
Link: https://lore.kernel.org/r/20240503150749.1001323-3-dhowells@redhat.com
Signed-off-by: Jakub Kicinski

rxrpc: Fix congestion control algorithm

2024-05-08T15:05:03+00:00

Make the following fixes to the congestion control algorithm:

 (1) Don't vary the cwnd starting value by the size of RXRPC_TX_SMSS since
     that's currently held constant - set to the size of a jumbo subpacket
     payload so that we can create jumbo packets on the fly.  The current
     code invariably picks 3 as the starting value.

     Further, the starting cwnd needs to be an even number because we ack
     every other packet, so set it to 4.

 (2) Don't cut ssthresh when we see an ACK come from the peer with a
     receive window (rwind) less than ssthresh.  ssthresh keeps track of
     characteristics of the connection whereas rwind may be reduced by the
     peer for any reason - and may be reduced to 0.

Fixes: 1fc4fa2ac93d ("rxrpc: Fix congestion management")
Fixes: 0851115090a3 ("rxrpc: Reduce ssthresh to peer's receive window")
Signed-off-by: David Howells 
Suggested-by: Simon Wilkinson 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Reviewed-by: Jeffrey Altman >
Link: https://lore.kernel.org/r/20240503150749.1001323-2-dhowells@redhat.com
Signed-off-by: Jakub Kicinski

rxrpc: Clients must accept conn from any address

2024-05-01T21:49:56+00:00

The find connection logic of Transarc's Rx was modified in the mid-1990s
to support multi-homed servers which might send a response packet from
an address other than the destination address in the received packet.
The rules for accepting a packet by an Rx initiator (RX_CLIENT_CONNECTION)
were altered to permit acceptance of a packet from any address provided
that the port number was unchanged and all of the connection identifiers
matched (Epoch, CID, SecurityClass, ...).

This change applies the same rules to the Linux implementation which makes
it consistent with IBM AFS 3.6, Arla, OpenAFS and AuriStorFS.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: Jeffrey Altman 
Acked-by: David Howells 
Signed-off-by: Marc Dionne 
Link: https://lore.kernel.org/r/20240419163057.4141728-1-marc.dionne@auristor.com
Signed-off-by: Jakub Kicinski

rxrpc: Fix using alignmask being zero for __page_frag_alloc_align()

2024-05-01T01:30:43+00:00

rxrpc_alloc_data_txbuf() may be called with data_align being
zero in none_alloc_txbuf() and rxkad_alloc_txbuf(), data_align
is supposed to be an order-based alignment value, but zero is
not a valid order-based alignment value, and '~(data_align - 1)'
doesn't result in a valid mask-based alignment value for
__page_frag_alloc_align().

Fix it by passing a valid order-based alignment value in
none_alloc_txbuf() and rxkad_alloc_txbuf().

Also use page_frag_alloc_align() expecting an order-based
alignment value in rxrpc_alloc_data_txbuf() to avoid doing the
alignment converting operation and to catch possible invalid
alignment value in the future. Remove the 'if (data_align)'
checking too, as it is always true for a valid order-based
alignment value.

Fixes: 6b2536462fd4 ("rxrpc: Fix use of changed alignment param to page_frag_alloc_align()")
Fixes: 49489bb03a50 ("rxrpc: Do zerocopy using MSG_SPLICE_PAGES and page frags")
CC: Alexander Duyck 
Signed-off-by: Yunsheng Lin 
Acked-by: David Howells 
Link: https://lore.kernel.org/r/20240428111640.27306-1-linyunsheng@huawei.com
Signed-off-by: Jakub Kicinski

rxrpc: Fix error check on ->alloc_txbuf()

2024-03-14T12:09:53+00:00

rxrpc_alloc_*_txbuf() and ->alloc_txbuf() return NULL to indicate no
memory, but rxrpc_send_data() uses IS_ERR().

Fix rxrpc_send_data() to check for NULL only and set -ENOMEM if it sees
that.

Fixes: 49489bb03a50 ("rxrpc: Do zerocopy using MSG_SPLICE_PAGES and page frags")
Signed-off-by: David Howells 
Reported-by: Marc Dionne 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Signed-off-by: Paolo Abeni

rxrpc: Fix use of changed alignment param to page_frag_alloc_align()

2024-03-14T12:09:52+00:00

Commit 411c5f36805c ("mm/page_alloc: modify page_frag_alloc_align() to
accept align as an argument") changed the way page_frag_alloc_align()
worked, but it didn't fix AF_RXRPC as that use of that allocator function
hadn't been merged yet at the time.  Now, when the AFS filesystem is used,
this results in:

  WARNING: CPU: 4 PID: 379 at include/linux/gfp.h:323 rxrpc_alloc_data_txbuf+0x9d/0x2b0 [rxrpc]

Fix this by using __page_frag_alloc_align() instead.

Note that it might be better to use an order-based alignment rather than a
mask-based alignment.

Fixes: 49489bb03a50 ("rxrpc: Do zerocopy using MSG_SPLICE_PAGES and page frags")
Signed-off-by: David Howells 
Reported-by: Marc Dionne 
cc: Yunsheng Lin 
cc: Alexander Duyck 
cc: Michael S. Tsirkin 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Signed-off-by: Paolo Abeni

rxrpc: Extract useful fields from a received ACK to skb priv data

2024-03-05T23:35:26+00:00

Extract useful fields from a received ACK packet into the skb private data
early on in the process of parsing incoming packets.  This makes the ACK
fields available even before we've matched the ACK up to a call and will
allow us to deal with path MTU discovery probe responses even after the
relevant call has been completed.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

rxrpc: Clean up the resend algorithm

2024-03-05T23:35:26+00:00

Clean up the DATA packet resending algorithm to retransmit packets as we
come across them whilst walking the transmission buffer rather than queuing
them for retransmission at the end.  This can be done as ACK parsing - and
thus the discarding of successful packets - is now done in the same thread
rather than separately in softirq context and a locked section is no longer
required.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

rxrpc: Record probes after transmission and reduce number of time-gets

2024-03-05T23:35:25+00:00

Move the recording of a successfully transmitted DATA or ACK packet that
will provide RTT probing to after the transmission.  With the I/O thread
model, this can be done because parsing of the responding ACK can no longer
race with the post-transmission code.

Move the various timeout-settings done after successfully transmitting a
DATA packet into rxrpc_tstamp_data_packets() and eliminate a number of
calls to get the current time.

As a consequence we no longer need to cancel a proposed RTT probe on
transmission failure.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

rxrpc: Use ktimes for call timeout tracking and set the timer lazily

2024-03-05T23:35:25+00:00

Track the call timeouts as ktimes rather than jiffies as the latter's
granularity is too high and only set the timer at the end of the event
handling function.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org