<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/include/trace/events/rxrpc.h, branch dev-4.18</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-4.18</id>
<link rel='self' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-4.18'/>
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<updated>2018-11-04T13:51:42+00:00</updated>
<entry>
<title>rxrpc: Fix error distribution</title>
<updated>2018-11-04T13:51:42+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-09-27T14:13:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=18cb92701a5d4d254d3000d888db7c5b0f2b68b5'/>
<id>urn:sha1:18cb92701a5d4d254d3000d888db7c5b0f2b68b5</id>
<content type='text'>
[ Upstream commit f334430316e7fd37c4821ebec627e27714bb5d76 ]

Fix error distribution by immediately delivering the errors to all the
affected calls rather than deferring them to a worker thread.  The problem
with the latter is that retries and things can happen in the meantime when we
want to stop that sooner.

To this end:

 (1) Stop the error distributor from removing calls from the error_targets
     list so that peer-&gt;lock isn't needed to synchronise against other adds
     and removals.

 (2) Require the peer's error_targets list to be accessed with RCU, thereby
     avoiding the need to take peer-&gt;lock over distribution.

 (3) Don't attempt to affect a call's state if it is already marked complete.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rxrpc: Fix handling of call quietly cancelled out on server</title>
<updated>2018-06-04T20:06:26+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-06-03T01:17:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=1a025028d400b23477341aa7ec2ce55f8b39b554'/>
<id>urn:sha1:1a025028d400b23477341aa7ec2ce55f8b39b554</id>
<content type='text'>
Sometimes an in-progress call will stop responding on the fileserver when
the fileserver quietly cancels the call with an internally marked abort
(RX_CALL_DEAD), without sending an ABORT to the client.

This causes the client's call to eventually expire from lack of incoming
packets directed its way, which currently leads to it being cancelled
locally with ETIME.  Note that it's not currently clear as to why this
happens as it's really hard to reproduce.

The rotation policy implement by kAFS, however, doesn't differentiate
between ETIME meaning we didn't get any response from the server and ETIME
meaning the call got cancelled mid-flow.  The latter leads to an oops when
fetching data as the rotation partially resets the afs_read descriptor,
which can result in a cleared page pointer being dereferenced because that
page has already been filled.

Handle this by the following means:

 (1) Set a flag on a call when we receive a packet for it.

 (2) Store the highest packet serial number so far received for a call
     (bearing in mind this may wrap).

 (3) If, when the "not received anything recently" timeout expires on a
     call, we've received at least one packet for a call and the connection
     as a whole has received packets more recently than that call, then
     cancel the call locally with ECONNRESET rather than ETIME.

     This indicates that the call was definitely in progress on the server.

 (4) In kAFS, if the rotation algorithm sees ECONNRESET rather than ETIME,
     don't try the next server, but rather abort the call.

     This avoids the oops as we don't try to reuse the afs_read struct.
     Rather, as-yet ungotten pages will be reread at a later data.

Also:

 (5) Add an rxrpc tracepoint to log detection of the call being reset.

Without this, I occasionally see an oops like the following:

    general protection fault: 0000 [#1] SMP PTI
    ...
    RIP: 0010:_copy_to_iter+0x204/0x310
    RSP: 0018:ffff8800cae0f828 EFLAGS: 00010206
    RAX: 0000000000000560 RBX: 0000000000000560 RCX: 0000000000000560
    RDX: ffff8800cae0f968 RSI: ffff8800d58b3312 RDI: 0005080000000000
    RBP: ffff8800cae0f968 R08: 0000000000000560 R09: ffff8800ca00f400
    R10: ffff8800c36f28d4 R11: 00000000000008c4 R12: ffff8800cae0f958
    R13: 0000000000000560 R14: ffff8800d58b3312 R15: 0000000000000560
    FS:  00007fdaef108080(0000) GS:ffff8800ca680000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007fb28a8fa000 CR3: 00000000d2a76002 CR4: 00000000001606e0
    Call Trace:
     skb_copy_datagram_iter+0x14e/0x289
     rxrpc_recvmsg_data.isra.0+0x6f3/0xf68
     ? trace_buffer_unlock_commit_regs+0x4f/0x89
     rxrpc_kernel_recv_data+0x149/0x421
     afs_extract_data+0x1e0/0x798
     ? afs_wait_for_call_to_complete+0xc9/0x52e
     afs_deliver_fs_fetch_data+0x33a/0x5ab
     afs_deliver_to_call+0x1ee/0x5e0
     ? afs_wait_for_call_to_complete+0xc9/0x52e
     afs_wait_for_call_to_complete+0x12b/0x52e
     ? wake_up_q+0x54/0x54
     afs_make_call+0x287/0x462
     ? afs_fs_fetch_data+0x3e6/0x3ed
     ? rcu_read_lock_sched_held+0x5d/0x63
     afs_fs_fetch_data+0x3e6/0x3ed
     afs_fetch_data+0xbb/0x14a
     afs_readpages+0x317/0x40d
     __do_page_cache_readahead+0x203/0x2ba
     ? ondemand_readahead+0x3a7/0x3c1
     ondemand_readahead+0x3a7/0x3c1
     generic_file_buffered_read+0x18b/0x62f
     __vfs_read+0xdb/0xfe
     vfs_read+0xb2/0x137
     ksys_read+0x50/0x8c
     do_syscall_64+0x7d/0x1a0
     entry_SYSCALL_64_after_hwframe+0x49/0xbe

Note the weird value in RDI which is a result of trying to kmap() a NULL
page pointer.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>rxrpc: Trace UDP transmission failure</title>
<updated>2018-05-10T22:26:01+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-05-10T22:26:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=6b47fe1d1ca3aec3a1a8623439c22fbf51016cd8'/>
<id>urn:sha1:6b47fe1d1ca3aec3a1a8623439c22fbf51016cd8</id>
<content type='text'>
Add a tracepoint to log transmission failure from the UDP transport socket
being used by AF_RXRPC.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
<entry>
<title>rxrpc: Add a tracepoint to log ICMP/ICMP6 and error messages</title>
<updated>2018-05-10T22:26:01+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-05-10T22:26:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=494337c918403db5743af0348d963cafb9b20cee'/>
<id>urn:sha1:494337c918403db5743af0348d963cafb9b20cee</id>
<content type='text'>
Add a tracepoint to log received ICMP/ICMP6 events and other error
messages.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
<entry>
<title>rxrpc: Add a tracepoint to track rxrpc_peer refcounting</title>
<updated>2018-03-30T20:05:38+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-03-30T20:05:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=1159d4b496f57d5b8ee27c8b90b9d01c332e2e11'/>
<id>urn:sha1:1159d4b496f57d5b8ee27c8b90b9d01c332e2e11</id>
<content type='text'>
Add a tracepoint to track reference counting on the rxrpc_peer struct.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
<entry>
<title>rxrpc: Add a tracepoint to track rxrpc_local refcounting</title>
<updated>2018-03-30T20:05:28+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-03-30T20:05:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=09d2bf595db4b4075ea721acd61e180d6bb18f88'/>
<id>urn:sha1:09d2bf595db4b4075ea721acd61e180d6bb18f88</id>
<content type='text'>
Add a tracepoint to track reference counting on the rxrpc_local struct.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
<entry>
<title>rxrpc: Trace call completion</title>
<updated>2018-03-27T22:08:20+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-03-27T22:08:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=1bae5d229532b4e8dfd5728cb3b8373bc9eec9eb'/>
<id>urn:sha1:1bae5d229532b4e8dfd5728cb3b8373bc9eec9eb</id>
<content type='text'>
Add a tracepoint to track rxrpc calls moving into the completed state and
to log the completion type and the recorded error value and abort code.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
<entry>
<title>rxrpc, afs: Use debug_ids rather than pointers in traces</title>
<updated>2018-03-27T22:03:00+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-03-27T22:03:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=a25e21f0bcd25673b91b97b9805db33350feec0f'/>
<id>urn:sha1:a25e21f0bcd25673b91b97b9805db33350feec0f</id>
<content type='text'>
In rxrpc and afs, use the debug_ids that are monotonically allocated to
various objects as they're allocated rather than pointers as kernel
pointers are now hashed making them less useful.  Further, the debug ids
aren't reused anywhere nearly as quickly.

In addition, allow kernel services that use rxrpc, such as afs, to take
numbers from the rxrpc counter, assign them to their own call struct and
pass them in to rxrpc for both client and service calls so that the trace
lines for each will have the same ID tag.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
<entry>
<title>rxrpc: Trace resend</title>
<updated>2018-03-27T22:02:47+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-03-27T22:02:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=827efed6a66ef8a1c071400b5952fee4a5ffedf9'/>
<id>urn:sha1:827efed6a66ef8a1c071400b5952fee4a5ffedf9</id>
<content type='text'>
Add a tracepoint to trace packet resend events and to dump the Tx
annotation buffer for added illumination.

Signed-off-by: David Howells &lt;dhowells@rdhat.com&gt;
</content>
</entry>
<entry>
<title>rxrpc: Fix service endpoint expiry</title>
<updated>2017-11-24T10:18:42+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-11-24T10:18:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=f859ab61875978eeaa539740ff7f7d91f5d60006'/>
<id>urn:sha1:f859ab61875978eeaa539740ff7f7d91f5d60006</id>
<content type='text'>
RxRPC service endpoints expire like they're supposed to by the following
means:

 (1) Mark dead rxrpc_net structs (with -&gt;live) rather than twiddling the
     global service conn timeout, otherwise the first rxrpc_net struct to
     die will cause connections on all others to expire immediately from
     then on.

 (2) Mark local service endpoints for which the socket has been closed
     (-&gt;service_closed) so that the expiration timeout can be much
     shortened for service and client connections going through that
     endpoint.

 (3) rxrpc_put_service_conn() needs to schedule the reaper when the usage
     count reaches 1, not 0, as idle conns have a 1 count.

 (4) The accumulator for the earliest time we might want to schedule for
     should be initialised to jiffies + MAX_JIFFY_OFFSET, not ULONG_MAX as
     the comparison functions use signed arithmetic.

 (5) Simplify the expiration handling, adding the expiration value to the
     idle timestamp each time rather than keeping track of the time in the
     past before which the idle timestamp must go to be expired.  This is
     much easier to read.

 (6) Ignore the timeouts if the net namespace is dead.

 (7) Restart the service reaper work item rather the client reaper.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
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