Changes in peer_object.c

40e8b52f - afs: Use the per-peer app data provided by rxrpc

Thu, 23 Jan 2025 11:01:55 +0000

afs: Use the per-peer app data provided by rxrpcMake use of the per-peer application data that rxrpc now allows theapplication to store on the rxrpc_peer struct to hold a back pointer to theafs_server record that peer represents an endpoint for.Then, when a call comes in to the AFS cache manager, this can be used tomap it to the correct server record rather than having to use aUUID-to-server mapping table and having to do an additional lookup.Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.orgcc: linux-fsdevel@vger.kernel.orgLink: https://lore.kernel.org/r/20250224234154.2014840-14-dhowells@redhat.com/ # v1Link: https://lore.kernel.org/r/20250310094206.801057-10-dhowells@redhat.com/ # v4 List of files: /linux-6.15/net/rxrpc/peer_object.c

f3a123b2 - rxrpc: Allow the app to store private data on peer structs

Thu, 23 Jan 2025 09:00:33 +0000

rxrpc: Allow the app to store private data on peer structsProvide a way for the application (e.g. the afs filesystem) to storeprivate data on the rxrpc_peer structs for later retrieval via the callobject.This will allow afs to store a pointer to the afs_server object on therxrpc_peer struct, thereby obviating the need for afs to keep lookup tablesby which it can associate an incoming call with server that transmitted it.Signed-off-by: David Howells cc: Marc Dionne cc: Jakub Kicinski cc: "David S. Miller" cc: Eric Dumazet cc: Paolo Abeni cc: Simon Horman cc: linux-afs@lists.infradead.orgcc: linux-fsdevel@vger.kernel.orgcc: netdev@vger.kernel.orgLink: https://lore.kernel.org/r/20250224234154.2014840-13-dhowells@redhat.com/ # v1Link: https://lore.kernel.org/r/20250310094206.801057-9-dhowells@redhat.com/ # v4 List of files: /linux-6.15/net/rxrpc/peer_object.c

71f54091 - rxrpc: Fix locking issues with the peer record hash

Tue, 18 Feb 2025 19:22:46 +0000

rxrpc: Fix locking issues with the peer record hashrxrpc_new_incoming_peer() can't use spin_lock_bh() whilst its caller hasinterrupts disabled. WARNING: CPU: 0 PID: 1550 at kernel/softirq.c:369 __local_bh_enable_ip+0x46/0xd0 ... Call Trace: rxrpc_alloc_incoming_call+0x1b0/0x400 rxrpc_new_incoming_call+0x1dd/0x5e0 rxrpc_input_packet+0x84a/0x920 rxrpc_io_thread+0x40d/0xb40 kthread+0x2ec/0x300 ret_from_fork+0x24/0x40 ret_from_fork_asm+0x1a/0x30 irq event stamp: 1811 hardirqs last enabled at (1809): _raw_spin_unlock_irq+0x24/0x50 hardirqs last disabled at (1810): _raw_read_lock_irq+0x17/0x70 softirqs last enabled at (1182): handle_softirqs+0x3ee/0x430 softirqs last disabled at (1811): rxrpc_new_incoming_peer+0x56/0x120Fix this by using a plain spin_lock() instead. IRQs are held, so softirqscan't happen.Fixes: a2ea9a907260 ("rxrpc: Use irq-disabling spinlocks between app and I/O thread")Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.orgLink: https://patch.msgid.link/20250218192250.296870-4-dhowells@redhat.comSigned-off-by: Jakub Kicinski List of files: /linux-6.15/net/rxrpc/peer_object.c

833fefa0 - rxrpc: peer->mtu_lock is redundant

Tue, 18 Feb 2025 19:22:45 +0000

rxrpc: peer->mtu_lock is redundantThe peer->mtu_lock is only used to lock around writes to peer->max_data -and nothing else; further, all such writes take place in the I/O thread andthe lock is only ever write-locked and never read-locked.In a couple of places, the write_seqcount_begin() is wrapped inpreempt_disable/enable(), but not in all places. This can cause lockdep tocomplain:WARNING: CPU: 0 PID: 1549 at include/linux/seqlock.h:221 rxrpc_input_ack_trailer+0x305/0x430...RIP: 0010:rxrpc_input_ack_trailer+0x305/0x430Fix this by just getting rid of the lock.Fixes: eeaedc5449d9 ("rxrpc: Implement path-MTU probing using padded PING ACKs (RFC8899)")Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.orgLink: https://patch.msgid.link/20250218192250.296870-3-dhowells@redhat.comSigned-off-by: Jakub Kicinski List of files: /linux-6.15/net/rxrpc/peer_object.c

79d458c1 - rxrpc, afs: Fix peer hash locking vs RCU callback

Thu, 23 Jan 2025 08:59:12 +0000

rxrpc, afs: Fix peer hash locking vs RCU callbackIn its address list, afs now retains pointers to and refs on one or morerxrpc_peer objects. The address list is freed under RCU and at this time,it puts the refs on those peers.Now, when an rxrpc_peer object runs out of refs, it gets removed from thepeer hash table and, for that, rxrpc has to take a spinlock. However, itis now being called from afs's RCU cleanup, which takes place in BHcontext - but it is just taking an ordinary spinlock.The put may also be called from non-BH context, and so there exists thepossibility of deadlock if the BH-based RCU cleanup happens whilst the hashspinlock is held. This led to the attached lockdep complaint.Fix this by changing spinlocks of rxnet->peer_hash_lock back toBH-disabling locks. ================================ WARNING: inconsistent lock state 6.13.0-rc5-build2+ #1223 Tainted: G E -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff88810babe228 (&rxnet->peer_hash_lock){+.?.}-{3:3}, at: rxrpc_put_peer+0xcb/0x180 {SOFTIRQ-ON-W} state was registered at: mark_usage+0x164/0x180 __lock_acquire+0x544/0x990 lock_acquire.part.0+0x103/0x280 _raw_spin_lock+0x2f/0x40 rxrpc_peer_keepalive_worker+0x144/0x440 process_one_work+0x486/0x7c0 process_scheduled_works+0x73/0x90 worker_thread+0x1c8/0x2a0 kthread+0x19b/0x1b0 ret_from_fork+0x24/0x40 ret_from_fork_asm+0x1a/0x30 irq event stamp: 972402 hardirqs last enabled at (972402): [] _raw_spin_unlock_irqrestore+0x2e/0x50 hardirqs last disabled at (972401): [] _raw_spin_lock_irqsave+0x18/0x60 softirqs last enabled at (972300): [] handle_softirqs+0x3ee/0x430 softirqs last disabled at (972313): [] __irq_exit_rcu+0x44/0x110 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&rxnet->peer_hash_lock); lock(&rxnet->peer_hash_lock); *** DEADLOCK *** 1 lock held by swapper/1/0: #0: ffffffff83576be0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire+0x7/0x30 stack backtrace: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G E 6.13.0-rc5-build2+ #1223 Tainted: [E]=UNSIGNED_MODULE Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Call Trace: dump_stack_lvl+0x57/0x80 print_usage_bug.part.0+0x227/0x240 valid_state+0x53/0x70 mark_lock_irq+0xa5/0x2f0 mark_lock+0xf7/0x170 mark_usage+0xe1/0x180 __lock_acquire+0x544/0x990 lock_acquire.part.0+0x103/0x280 _raw_spin_lock+0x2f/0x40 rxrpc_put_peer+0xcb/0x180 afs_free_addrlist+0x46/0x90 [kafs] rcu_do_batch+0x2d2/0x640 rcu_core+0x2f7/0x350 handle_softirqs+0x1ee/0x430 __irq_exit_rcu+0x44/0x110 irq_exit_rcu+0xa/0x30 sysvec_apic_timer_interrupt+0x7f/0xa0 Fixes: 72904d7b9bfb ("rxrpc, afs: Allow afs to pin rxrpc_peer objects")Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.orgLink: https://patch.msgid.link/2095618.1737622752@warthog.procyon.org.ukSigned-off-by: Jakub Kicinski List of files: /linux-6.15/net/rxrpc/peer_object.c

b40ef2b8 - rxrpc: Manage RTT per-call rather than per-peer

Wed, 04 Dec 2024 07:47:05 +0000

rxrpc: Manage RTT per-call rather than per-peerManage the determination of RTT on a per-call (ie. per-RPC op) basis ratherthan on a per-peer basis, averaging across all calls going to that peer.The problem is that the RTT measurements from the initial packets on a callmay be off because the server may do some setting up (such as getting alock on a file) before accepting the rest of the data in the RPC and,further, the RTT may be affected by server-side file operations, forinstance if a large amount of data is being written or read.Note: When handling the FS.StoreData-type RPCs, for example, the serveruses the userStatus field in the header of ACK packets as supplementaryflow control to aid in managing this. AF_RXRPC does not yet support this,but it should be added.Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.orgSigned-off-by: Jakub Kicinski List of files: /linux-6.15/net/rxrpc/peer_object.c

a2ea9a90 - rxrpc: Use irq-disabling spinlocks between app and I/O thread

Wed, 04 Dec 2024 07:47:01 +0000

rxrpc: Use irq-disabling spinlocks between app and I/O threadWhere a spinlock is used by both the application thread and the I/O thread,use irq-disabling locking so that an interrupt taken on the app threaddoesn't also slow down the I/O thread.Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.orgSigned-off-by: Jakub Kicinski List of files: /linux-6.15/net/rxrpc/peer_object.c

eeaedc54 - rxrpc: Implement path-MTU probing using padded PING ACKs (RFC8899)

Wed, 04 Dec 2024 07:46:37 +0000

rxrpc: Implement path-MTU probing using padded PING ACKs (RFC8899)Implement path-MTU probing (along the lines of RFC8899) by padding some ofthe PING ACKs we send. PING ACKs get their own individual responses quiteapart from the acking of data (though, as ACKs, they fulfil that rolealso).The probing concentrates on packet sizes that correspond how manysubpackets can be stuffed inside a jumbo packet as jumbo DATA packets arejust aggregations of individual DATA packets and can be split easily forretransmission purposes.If we want to perform probing, we advertise this by setting the maximumnumber of jumbo subpackets to 0 in the ack trailer when we send an ACK andsee if the peer is also advertising the service. This is interpreted bynon-supporting Rx stacks as an indication that jumbo packets aren'tsupported.The MTU sizes advertised in the ACK trailer AF_RXRPC transmits are peggedat a maximum of 1444 unless pmtud is supported by both sides.Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.orgLink: https://patch.msgid.link/20241204074710.990092-10-dhowells@redhat.comSigned-off-by: Jakub Kicinski List of files: /linux-6.15/net/rxrpc/peer_object.c

72904d7b - rxrpc, afs: Allow afs to pin rxrpc_peer objects

Thu, 19 Oct 2023 11:55:11 +0000

rxrpc, afs: Allow afs to pin rxrpc_peer objectsChange 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 isusing, allowing faster lookups and pointer comparisons rather thancomparing sockaddr_rxrpc contents. It also makes it easier to get hold ofthe 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 cc: Marc Dionne cc: linux-afs@lists.infradead.org List of files: /linux-6.15/net/rxrpc/peer_object.c

8a758d98 - rxrpc: Stash the network namespace pointer in rxrpc_local

Thu, 20 Oct 2022 22:17:06 +0000

rxrpc: Stash the network namespace pointer in rxrpc_localStash the network namespace pointer in the rxrpc_local struct in additionto a pointer to the rxrpc-specific net namespace info. Use this to removesome places where the socket is passed as a parameter.Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org List of files: /linux-6.15/net/rxrpc/peer_object.c

c838f1a7 - rxrpc: Fix switched parameters in peer tracing

Thu, 15 Dec 2022 16:20:30 +0000

rxrpc: Fix switched parameters in peer tracingFix 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 cc: Marc Dionne cc: linux-afs@lists.infradead.orgSigned-off-by: David S. Miller List of files: /linux-6.15/net/rxrpc/peer_object.c

608aecd1 - rxrpc: Fix locking issues in rxrpc_put_peer_locked()

Thu, 15 Dec 2022 16:20:21 +0000

rxrpc: Fix locking issues in rxrpc_put_peer_locked()Now that rxrpc_put_local() may call kthread_stop(), it can't be calledunder spinlock as it might sleep. This can cause a problem in the peerkeepalive code in rxrpc as it tries to avoid dropping the peer_hash_lockfrom the point it needs to re-add peer->keepalive_link to going round theloop again in rxrpc_peer_keepalive_dispatch().Fix this by just dropping the lock when we don't need it and accepting thatwe'll have to take it again. This code is only called about every 20s foreach peer, so not very often.This allows rxrpc_put_peer_unlocked() to be removed also.If triggered, this bug produces an oops like the following, as reproducedby a syzbot reproducer for a different oops[1]:BUG: sleeping function called from invalid context at kernel/sched/completion.c:101...RCU nest depth: 0, expected: 03 locks held by kworker/u9:0/50: #0: ffff88810e74a138 ((wq_completion)krxrpcd){+.+.}-{0:0}, at: process_one_work+0x294/0x636 #1: ffff8881013a7e20 ((work_completion)(&rxnet->peer_keepalive_work)){+.+.}-{0:0}, at: process_one_work+0x294/0x636 #2: ffff88817d366390 (&rxnet->peer_hash_lock){+.+.}-{2:2}, at: rxrpc_peer_keepalive_dispatch+0x2bd/0x35f...Call Trace: dump_stack_lvl+0x4c/0x5f __might_resched+0x2cf/0x2f2 __wait_for_common+0x87/0x1e8 kthread_stop+0x14d/0x255 rxrpc_peer_keepalive_dispatch+0x333/0x35f rxrpc_peer_keepalive_worker+0x2e9/0x449 process_one_work+0x3c1/0x636 worker_thread+0x25f/0x359 kthread+0x1a6/0x1b5 ret_from_fork+0x1f/0x30Fixes: a275da62e8c1 ("rxrpc: Create a per-local endpoint receive queue and I/O thread")Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.orgLink: https://lore.kernel.org/r/0000000000002b4a9f05ef2b616f@google.com/ [1]Signed-off-by: David S. Miller List of files: /linux-6.15/net/rxrpc/peer_object.c

3dd9c8b5 - rxrpc: Remove the _bh annotation from all the spinlocks

Fri, 24 Jan 2020 10:21:15 +0000

rxrpc: Remove the _bh annotation from all the spinlocksNone of the spinlocks in rxrpc need a _bh annotation now as the RCUcallback routines no longer take spinlocks and the bulk of the packetwrangling code is now run in the I/O thread, not softirq context.Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org List of files: /linux-6.15/net/rxrpc/peer_object.c

47c810a7 - rxrpc: trace: Don't use __builtin_return_address for rxrpc_peer tracing

Fri, 21 Oct 2022 12:39:34 +0000

rxrpc: trace: Don't use __builtin_return_address for rxrpc_peer tracingIn rxrpc tracing, use enums to generate lists of points of interest ratherthan __builtin_return_address() for the rxrpc_peer tracepointSigned-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org List of files: /linux-6.15/net/rxrpc/peer_object.c

0fde882f - rxrpc: trace: Don't use __builtin_return_address for rxrpc_local tracing

Fri, 21 Oct 2022 12:00:34 +0000

rxrpc: trace: Don't use __builtin_return_address for rxrpc_local tracingIn rxrpc tracing, use enums to generate lists of points of interest ratherthan __builtin_return_address() for the rxrpc_local tracepointSigned-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org List of files: /linux-6.15/net/rxrpc/peer_object.c

e969c92c - rxrpc: Remove the [_k]net() debugging macros

Thu, 20 Oct 2022 11:04:20 +0000

rxrpc: Remove the [_k]net() debugging macrosRemove the _net() and knet() debugging macros in favour of tracepoints.Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org List of files: /linux-6.15/net/rxrpc/peer_object.c

1fc4fa2a - rxrpc: Fix congestion management

Mon, 03 Oct 2022 17:49:11 +0000

rxrpc: Fix congestion managementrxrpc has a problem in its congestion management in that it saves thecongestion window size (cwnd) from one call to another, but if this is 0 atthe time is saved, then the next call may not actually manage to evertransmit 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'tbeing filled due to being application limited.Reported-by: Simon Wilkinson cc: Marc Dionne cc: linux-afs@lists.infradead.org List of files: /linux-6.15/net/rxrpc/peer_object.c

a0575429 - rxrpc: Use refcount_t rather than atomic_t

Sat, 21 May 2022 07:45:22 +0000

rxrpc: Use refcount_t rather than atomic_tMove to using refcount_t rather than atomic_t for refcounts in rxrpc.Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.orgSigned-off-by: David S. Miller List of files: /linux-6.15/net/rxrpc/peer_object.c

beacff50 - rxrpc: Fix rxrpc_local leak in rxrpc_lookup_peer()

Sun, 21 Nov 2021 04:16:08 +0000

rxrpc: Fix rxrpc_local leak in rxrpc_lookup_peer()Need to call rxrpc_put_local() for peer candidate before kfree() as itholds a ref to rxrpc_local.[DH: v2: Changed to abstract the peer freeing code out into a function]Fixes: 9ebeddef58c4 ("rxrpc: rxrpc_peer needs to hold a ref on the rxrpc_local record")Signed-off-by: Eiichi Tsukata Signed-off-by: David Howells Reviewed-by: Marc Dionne cc: linux-afs@lists.infradead.orgLink: https://lore.kernel.org/all/20211121041608.133740-2-eiichi.tsukata@nutanix.com/ # v1 List of files: /linux-6.15/net/rxrpc/peer_object.c

1d4adfaf - rxrpc: Make rxrpc_kernel_get_srtt() indicate validity

Thu, 20 Aug 2020 14:13:00 +0000

rxrpc: Make rxrpc_kernel_get_srtt() indicate validityFix rxrpc_kernel_get_srtt() to indicate the validity of the returnedsmoothed RTT. If we haven't had any valid samples yet, the SRTT isn'tuseful.Fixes: c410bf01933e ("rxrpc: Fix the excessive initial retransmission timeout")Signed-off-by: David Howells List of files: /linux-6.15/net/rxrpc/peer_object.c