linux-toradex.git/net/rxrpc/local_object.c, branch v6.5

rxrpc: Remove local->defrag_sem

2023-01-31T16:38:35+00:00

We no longer need local->defrag_sem as all DATA packet transmission is now
done from one thread, so remove it.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Allow a delay to be injected into packet reception

2023-01-31T16:38:09+00:00

If CONFIG_AF_RXRPC_DEBUG_RX_DELAY=y, then a delay is injected between
packets and errors being received and them being made available to the
processing code, thereby allowing the RTT to be artificially increased.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Move client call connection to the I/O thread

2023-01-06T09:43:33+00:00

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 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Move the client conn cache management to the I/O thread

2023-01-06T09:43:33+00:00

Move the management of the client connection cache to the I/O thread rather
than managing it from the namespace as an aggregate across all the local
endpoints within the namespace.

This will allow a load of locking to be got rid of in a future patch as
only the I/O thread will be looking at the this.

The downside is that the total number of cached connections on the system
can get higher because the limit is now per-local rather than per-netns.
We can, however, keep the number of client conns in use across the entire
netfs and use that to reduce the expiration time of idle connection.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Make the set of connection IDs per local endpoint

2023-01-06T09:43:32+00:00

Make the set of connection IDs per local endpoint so that endpoints don't
cause each other's connections to get dismissed.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Implement a mechanism to send an event notification to a connection

2023-01-06T09:43:31+00:00

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 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Stash the network namespace pointer in rxrpc_local

2023-01-06T09:43:31+00:00

Stash the network namespace pointer in the rxrpc_local struct in addition
to a pointer to the rxrpc-specific net namespace info.  Use this to remove
some places where the socket is passed as a parameter.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Fix I/O thread startup getting skipped

2022-12-19T09:51:31+00:00

When starting a kthread, the __kthread_create_on_node() function, as called
from kthread_run(), waits for a completion to indicate that the task_struct
(or failure state) of the new kernel thread is available before continuing.

This does not wait, however, for the thread function to be invoked and,
indeed, will skip it if kthread_stop() gets called before it gets there.

If this happens, though, kthread_run() will have returned successfully,
indicating that the thread was started and returning the task_struct
pointer.  The actual error indication is returned by kthread_stop().

Note that this is ambiguous, as the caller cannot tell whether the -EINTR
error code came from kthread() or from the thread function.

This was encountered in the new rxrpc I/O thread, where if the system is
being pounded hard by, say, syzbot, the check of KTHREAD_SHOULD_STOP can be
delayed long enough for kthread_stop() to get called when rxrpc releases a
socket - and this causes an oops because the I/O thread function doesn't
get started and thus doesn't remove the rxrpc_local struct from the
local_endpoints list.

Fix this by using a completion to wait for the thread to actually enter
rxrpc_io_thread().  This makes sure the thread can't be prematurely
stopped and makes sure the relied-upon cleanup is done.

Fixes: a275da62e8c1 ("rxrpc: Create a per-local endpoint receive queue and I/O thread")
Reported-by: syzbot+3538a6a72efa8b059c38@syzkaller.appspotmail.com
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: Hillf Danton 
Link: https://lore.kernel.org/r/000000000000229f1505ef2b6159@google.com/
Signed-off-by: David S. Miller

rxrpc: Fix NULL deref in rxrpc_unuse_local()

2022-12-19T09:51:31+00:00

Fix rxrpc_unuse_local() to get the debug_id *after* checking to see if
local is NULL.

Fixes: a2cf3264f331 ("rxrpc: Fold __rxrpc_unuse_local() into rxrpc_unuse_local()")
Reported-by: syzbot+3538a6a72efa8b059c38@syzkaller.appspotmail.com
Signed-off-by: David Howells 
Tested-by: syzbot+3538a6a72efa8b059c38@syzkaller.appspotmail.com
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller

rxrpc: Transmit ACKs at the point of generation

2022-12-01T13:36:43+00:00

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 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org