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* rxrpc: Fix missing locking causing hanging callsDavid Howells12 days1-0/+1
| | | | | | | | | | | | | | | | | | | If a call gets aborted (e.g. because kafs saw a signal) between it being queued for connection and the I/O thread picking up the call, the abort will be prioritised over the connection and it will be removed from local->new_client_calls by rxrpc_disconnect_client_call() without a lock being held. This may cause other calls on the list to disappear if a race occurs. Fix this by taking the client_call_lock when removing a call from whatever list its ->wait_link happens to be on. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Reported-by: Marc Dionne <marc.dionne@auristor.com> Fixes: 9d35d880e0e4 ("rxrpc: Move client call connection to the I/O thread") Link: https://patch.msgid.link/726660.1730898202@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* rxrpc: Use ktimes for call timeout tracking and set the timer lazilyDavid Howells2024-03-051-81/+93
| | | | | | | | | | | | | | | 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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
* rxrpc: Differentiate PING ACK transmission traces.David Howells2024-03-051-0/+2
| | | | | | | | | | | | | | There are three points that transmit PING ACKs and all of them use the same trace string. Change two of them to use different strings. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
* rxrpc: Fix the names of the fields in the ACK trailer structDavid Howells2024-02-291-1/+1
| | | | | | | | | | | | | | | | | From AFS-3.3 a trailer containing extra info was added to the ACK packet format - but AF_RXRPC has the names of some of the fields mixed up compared to other AFS implementations. Rename the struct and the fields to make them match. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
* rxrpc: Convert rxrpc_txbuf::flags into a mask and don't use atomicsDavid Howells2024-02-291-7/+5
| | | | | | | | | | | | | | | | | | Convert the transmission buffer flags into a mask and use | and & rather than bitops functions (atomic ops are not required as only the I/O thread can manipulate them once submitted for transmission). The bottom byte can then correspond directly to the Rx protocol header flags. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
* rxrpc: Record the Tx serial in the rxrpc_txbuf and retransmit traceDavid Howells2024-02-291-3/+7
| | | | | | | | | | | | | | | | | | Each Rx protocol packet contains a per-connection monotonically increasing serial number used to correlate outgoing messages with their replies - something that can be used for RTT calculation. Note this value in the rxrpc_txbuf struct in addition to the wire header and then log it in the rxrpc_retransmit trace for reference. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
* rxrpc: Fix counting of new acks and nacksDavid Howells2024-02-051-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc, afs: Allow afs to pin rxrpc_peer objectsDavid Howells2023-12-241-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change rxrpc's API such that: (1) A new function, rxrpc_kernel_lookup_peer(), is provided to look up an rxrpc_peer record for a remote address and a corresponding function, rxrpc_kernel_put_peer(), is provided to dispose of it again. (2) When setting up a call, the rxrpc_peer object used during a call is now passed in rather than being set up by rxrpc_connect_call(). For afs, this meenat passing it to rxrpc_kernel_begin_call() rather than the full address (the service ID then has to be passed in as a separate parameter). (3) A new function, rxrpc_kernel_remote_addr(), is added so that afs can get a pointer to the transport address for display purposed, and another, rxrpc_kernel_remote_srx(), to gain a pointer to the full rxrpc address. (4) The function to retrieve the RTT from a call, rxrpc_kernel_get_srtt(), is then altered to take a peer. This now returns the RTT or -1 if there are insufficient samples. (5) Rename rxrpc_kernel_get_peer() to rxrpc_kernel_call_get_peer(). (6) Provide a new function, rxrpc_kernel_get_peer(), to get a ref on a peer the caller already has. This allows the afs filesystem to pin the rxrpc_peer records that it is using, allowing faster lookups and pointer comparisons rather than comparing sockaddr_rxrpc contents. It also makes it easier to get hold of the RTT. The following changes are made to afs: (1) The addr_list struct's addrs[] elements now hold a peer struct pointer and a service ID rather than a sockaddr_rxrpc. (2) When displaying the transport address, rxrpc_kernel_remote_addr() is used. (3) The port arg is removed from afs_alloc_addrlist() since it's always overridden. (4) afs_merge_fs_addr4() and afs_merge_fs_addr6() do peer lookup and may now return an error that must be handled. (5) afs_find_server() now takes a peer pointer to specify the address. (6) afs_find_server(), afs_compare_fs_alists() and afs_merge_fs_addr[46]{} now do peer pointer comparison rather than address comparison. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Fix RTT determination to use any ACK as a sourceDavid Howells2023-11-171-1/+1
| | | | | | | | | | | | | | | | | | | Fix RTT determination to be able to use any type of ACK as the response from which RTT can be calculated provided its ack.serial is non-zero and matches the serial number of an outgoing DATA or ACK packet. This shouldn't be limited to REQUESTED-type ACKs as these can have other types substituted for them for things like duplicate or out-of-order packets. Fixes: 4700c4d80b7b ("rxrpc: Fix loss of RTT samples due to interposed ACK") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Fix overproduction of wakeups to recvmsg()David Howells2023-02-201-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix three cases of overproduction of wakeups: (1) rxrpc_input_split_jumbo() conditionally notifies the app that there's data for recvmsg() to collect if it queues some data - and then its only caller, rxrpc_input_data(), goes and wakes up recvmsg() anyway. Fix the rxrpc_input_data() to only do the wakeup in failure cases. (2) If a DATA packet is received for a call by the I/O thread whilst recvmsg() is busy draining the call's rx queue in the app thread, the call will left on the recvmsg() queue for recvmsg() to pick up, even though there isn't any data on it. This can cause an unexpected recvmsg() with a 0 return and no MSG_EOR set after the reply has been posted to a service call. Fix this by discarding pending calls from the recvmsg() queue that don't need servicing yet. (3) Not-yet-completed calls get requeued after having data read from them, even if they have no data to read. Fix this by only requeuing them if they have data waiting on them; if they don't, the I/O thread will requeue them when data arrives or they fail. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/3386149.1676497685@warthog.procyon.org.uk Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* rxrpc: Trace ack.rwindDavid Howells2023-02-071-4/+7
| | | | | | | | | Log ack.rwind in the rxrpc_tx_ack tracepoint. This value is useful to see as it represents flow-control information to the peer. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Change rx_packet tracepoint to display securityIndex not type twiceDavid Howells2023-01-311-3/+2
| | | | | | | | | | | Change the rx_packet tracepoint to display the securityIndex from the packet header instead of displaying the type in numeric form. There's no need for the latter, as the display of the type in symbolic form will fall back automatically to displaying the hex value if no symbol is available. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Simplify ACK handlingDavid Howells2023-01-311-0/+36
| | | | | | | | | | | | | | | | | | Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: De-atomic call->ackr_window and call->ackr_nr_unackedDavid Howells2023-01-311-4/+6
| | | | | | | | | | | | call->ackr_window doesn't need to be atomic as ACK generation and ACK transmission are now done in the same thread, so drop the atomic64 handling and split it into two separate members. Similarly, call->ackr_nr_unacked doesn't need to be atomic now either. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Generate extra pings for RTT during heavy-receive callDavid Howells2023-01-311-1/+2
| | | | | | | | | | | | | When doing a call that has a single transmitted data packet and a massive amount of received data packets, we only ping for one RTT sample, which means we don't get a good reading on it. Fix this by converting occasional IDLE ACKs into PING ACKs to elicit a response. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Shrink the tabulation in the rxrpc trace header a bitDavid Howells2023-01-311-98/+98
| | | | | | | Shrink the tabulation in the rxrpc trace header a bit to allow for fields with long type names that have been removed. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Remove whitespace before ')' in trace headerDavid Howells2023-01-311-213/+213
| | | | | | | Work around checkpatch warnings in the rxrpc trace header by removing whitespace before ')' on lines defining the trace record struct. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix trace stringDavid Howells2023-01-301-1/+1
| | | | | | | | | Fix a trace string to indicate that it's discarding the local endpoint for a preallocated peer, not a preallocated connection. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Move client call connection to the I/O threadDavid Howells2023-01-061-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Move the connection setup of client calls to the I/O thread so that a whole load of locking and barrierage can be eliminated. This necessitates the app thread waiting for connection to complete before it can begin encrypting data. This also completes the fix for a race that exists between call connection and call disconnection whereby the data transmission code adds the call to the peer error distribution list after the call has been disconnected (say by the rxrpc socket getting closed). The fix is to complete the process of moving call connection, data transmission and call disconnection into the I/O thread and thus forcibly serialising them. Note that the issue may predate the overhaul to an I/O thread model that were included in the merge window for v6.2, but the timing is very much changed by the change given below. Fixes: cf37b5987508 ("rxrpc: Move DATA transmission into call processor work item") Reported-by: syzbot+c22650d2844392afdcfd@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Set up a connection bundle from a call, not rxrpc_conn_parametersDavid Howells2023-01-061-2/+1
| | | | | | | | | | Use the information now stored in struct rxrpc_call to configure the connection bundle and thence the connection, rather than using the rxrpc_conn_parameters struct. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Offload the completion of service conn security to the I/O threadDavid Howells2023-01-061-0/+2
| | | | | | | | | | | | | | | | Offload the completion of the challenge/response cycle on a service connection to the I/O thread. After the RESPONSE packet has been successfully decrypted and verified by the work queue, offloading the changing of the call states to the I/O thread makes iteration over the conn's channel list simpler. Do this by marking the RESPONSE skbuff and putting it onto the receive queue for the I/O thread to collect. We put it on the front of the queue as we've already received the packet for it. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Tidy up abort generation infrastructureDavid Howells2023-01-061-29/+111
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Clean up connection abortDavid Howells2023-01-061-0/+2
| | | | | | | | | | | Clean up connection abort, using the connection state_lock to gate access to change that state, and use an rxrpc_call_completion value to indicate the difference between local and remote aborts as these can be pasted directly into the call state. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Implement a mechanism to send an event notification to a connectionDavid Howells2023-01-061-3/+2
| | | | | | | | | | | | | | Provide a means by which an event notification can be sent to a connection through such that the I/O thread can pick it up and handle it rather than doing it in a separate workqueue. This is then used to move the deferred final ACK of a call into the I/O thread rather than a separate work queue as part of the drive to do all transmission from the I/O thread. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Only disconnect calls in the I/O threadDavid Howells2023-01-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Only perform call disconnection in the I/O thread to reduce the locking requirement. This is the first part of a fix for a race that exists between call connection and call disconnection whereby the data transmission code adds the call to the peer error distribution list after the call has been disconnected (say by the rxrpc socket getting closed). The fix is to complete the process of moving call connection, data transmission and call disconnection into the I/O thread and thus forcibly serialising them. Note that the issue may predate the overhaul to an I/O thread model that were included in the merge window for v6.2, but the timing is very much changed by the change given below. Fixes: cf37b5987508 ("rxrpc: Move DATA transmission into call processor work item") Reported-by: syzbot+c22650d2844392afdcfd@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Only set/transmit aborts in the I/O threadDavid Howells2023-01-061-0/+1
| | | | | | | | | | | | | | Only set the abort call completion state in the I/O thread and only transmit ABORT packets from there. rxrpc_abort_call() can then be made to actually send the packet. Further, ABORT packets should only be sent if the call has been exposed to the network (ie. at least one attempted DATA transmission has occurred for it). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Make the local endpoint hold a ref on a connected callDavid Howells2023-01-061-0/+3
| | | | | | | | | | | Make the local endpoint and it's I/O thread hold a reference on a connected call until that call is disconnected. Without this, we're reliant on either the AF_RXRPC socket to hold a ref (which is dropped when the call is released) or a queued work item to hold a ref (the work item is being replaced with the I/O thread). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Fix a couple of potential use-after-freesDavid Howells2022-12-281-3/+3
| | | | | | | | | | | | | | | At the end of rxrpc_recvmsg(), if a call is found, the call is put and then a trace line is emitted referencing that call in a couple of places - but the call may have been deallocated by the time those traces happen. Fix this by stashing the call debug_id in a variable and passing that to the tracepoint rather than the call pointer. Fixes: 849979051cbc ("rxrpc: Add a tracepoint to follow what recvmsg does") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Fix switched parameters in peer tracingDavid Howells2022-12-191-1/+1
| | | | | | | | | | | Fix the switched parameters on rxrpc_alloc_peer() and rxrpc_get_peer(). The ref argument and the why argument got mixed. Fixes: 47c810a79844 ("rxrpc: trace: Don't use __builtin_return_address for rxrpc_peer tracing") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Transmit ACKs at the point of generationDavid Howells2022-12-011-3/+0
| | | | | | | | | | For ACKs generated inside the I/O thread, transmit the ACK at the point of generation. Where the ACK is generated outside of the I/O thread, it's offloaded to the I/O thread to transmit it. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Trace/count transmission underflows and cwnd resetsDavid Howells2022-12-011-0/+38
| | | | | | | | | | | | | Add a tracepoint to log when a cwnd reset occurs due to lack of transmission on a call. Add stat counters to count transmission underflows (ie. when we have tx window space, but sendmsg doesn't manage to keep up), cwnd resets and transmission failures. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Make the I/O thread take over the call and local processor workDavid Howells2022-12-011-22/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Simplify skbuff accounting in receive pathDavid Howells2022-12-011-1/+2
| | | | | | | | | | | | | | | A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Move DATA transmission into call processor work itemDavid Howells2022-12-011-1/+5
| | | | | | | | | | | | | | | | | | | Move DATA transmission into the call processor work item. In a future patch, this will be called from the I/O thread rather than being itsown work item. This will allow DATA transmission to be driven directly by incoming ACKs, pokes and timers as those are processed. The Tx queue is also split: The queue of packets prepared by sendmsg is now places in call->tx_sendmsg and the packet dispatcher decants the packets into call->tx_buffer as space becomes available in the transmission window. This allows sendmsg to run ahead of the available space to try and prevent an underflow in transmission. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Copy client call parameters into rxrpc_call earlierDavid Howells2022-12-011-0/+3
| | | | | | | | | | Copy client call parameters into rxrpc_call earlier so that that can be used to convey them to the connection code - which can then be offloaded to the I/O thread. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Implement a mechanism to send an event notification to a callDavid Howells2022-12-011-0/+52
| | | | | | | | | | Provide a means by which an event notification can be sent to a call such that the I/O thread can process it rather than it being done in a separate workqueue. This will allow a lot of locking to be removed. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Don't hold a ref for connection workqueueDavid Howells2022-12-011-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, rxrpc gives the connection's work item a ref on the connection when it queues it - and this is called from the timer expiration function. The problem comes when queue_work() fails (ie. the work item is already queued): the timer routine must put the ref - but this may cause the cleanup code to run. This has the unfortunate effect that the cleanup code may then be run in softirq context - which means that any spinlocks it might need to touch have to be guarded to disable softirqs (ie. they need a "_bh" suffix). (1) Don't give a ref to the work item. (2) Simplify handling of service connections by adding a separate active count so that the refcount isn't also used for this. (3) Connection destruction for both client and service connections can then be cleaned up by putting rxrpc_put_connection() out of line and making a tidy progression through the destruction code (offloaded to a workqueue if put from softirq or processor function context). The RCU part of the cleanup then only deals with the freeing at the end. (4) Make rxrpc_queue_conn() return immediately if it sees the active count is -1 rather then queuing the connection. (5) Make sure that the cleanup routine waits for the work item to complete. (6) Stash the rxrpc_net pointer in the conn struct so that the rcu free routine can use it, even if the local endpoint has been freed. Unfortunately, neither the timer nor the work item can simply get around the problem by just using refcount_inc_not_zero() as the waits would still have to be done, and there would still be the possibility of having to put the ref in the expiration function. Note the connection work item is mostly going to go away with the main event work being transferred to the I/O thread, so the wait in (6) will become obsolete. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Don't hold a ref for call timer or workqueueDavid Howells2022-12-011-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, rxrpc gives the call timer a ref on the call when it starts it and this is passed along to the workqueue by the timer expiration function. The problem comes when queue_work() fails (ie. the work item is already queued): the timer routine must put the ref - but this may cause the cleanup code to run. This has the unfortunate effect that the cleanup code may then be run in softirq context - which means that any spinlocks it might need to touch have to be guarded to disable softirqs (ie. they need a "_bh" suffix). Fix this by: (1) Don't give a ref to the timer. (2) Making the expiration function not do anything if the refcount is 0. Note that this is more of an optimisation. (3) Make sure that the cleanup routine waits for timer to complete. However, this has a consequence that timer cannot give a ref to the work item. Therefore the following fixes are also necessary: (4) Don't give a ref to the work item. (5) Make the work item return asap if it sees the ref count is 0. (6) Make sure that the cleanup routine waits for the work item to complete. Unfortunately, neither the timer nor the work item can simply get around the problem by just using refcount_inc_not_zero() as the waits would still have to be done, and there would still be the possibility of having to put the ref in the expiration function. Note the call work item is going to go away with the work being transferred to the I/O thread, so the wait in (6) will become obsolete. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: trace: Don't use __builtin_return_address for sk_buff tracingDavid Howells2022-12-011-24/+33
| | | | | | | | | In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the sk_buff tracepoint. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Trace rxrpc_bundle refcountDavid Howells2022-12-011-0/+34
| | | | | | | | Add a tracepoint for the rxrpc_bundle refcounting. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: trace: Don't use __builtin_return_address for rxrpc_call tracingDavid Howells2022-12-011-34/+49
| | | | | | | | | In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_call tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: trace: Don't use __builtin_return_address for rxrpc_conn tracingDavid Howells2022-12-011-21/+37
| | | | | | | | | In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_conn tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: trace: Don't use __builtin_return_address for rxrpc_peer tracingDavid Howells2022-12-011-17/+26
| | | | | | | | | In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_peer tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: trace: Don't use __builtin_return_address for rxrpc_local tracingDavid Howells2022-12-011-13/+36
| | | | | | | | | In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_local tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Remove the [k_]proto() debugging macrosDavid Howells2022-12-011-0/+60
| | | | | | | | | Remove the kproto() and _proto() debugging macros in preference to using tracepoints for this. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Fix congestion managementDavid Howells2022-11-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | rxrpc has a problem in its congestion management in that it saves the congestion window size (cwnd) from one call to another, but if this is 0 at the time is saved, then the next call may not actually manage to ever transmit anything. To this end: (1) Don't save cwnd between calls, but rather reset back down to the initial cwnd and re-enter slow-start if data transmission is idle for more than an RTT. (2) Preserve ssthresh instead, as that is a handy estimate of pipe capacity. Knowing roughly when to stop slow start and enter congestion avoidance can reduce the tendency to overshoot and drop larger amounts of packets when probing. In future, cwind growth also needs to be constrained when the window isn't being filled due to being application limited. Reported-by: Simon Wilkinson <sxw@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Save last ACK's SACK table rather than marking txbufsDavid Howells2022-11-081-3/+4
| | | | | | | | | | | | | | | | | | | | Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Don't use a ring buffer for call Tx queueDavid Howells2022-11-081-38/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Get rid of the Rx ringDavid Howells2022-11-081-8/+11
| | | | | | | | | | | | | | | | | | | | | Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* rxrpc: Clone received jumbo subpackets and queue separatelyDavid Howells2022-11-081-7/+5
| | | | | | | | | | | | | | | | | | | | Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org