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<title>user/sven/linux.git/include/trace/events, branch v5.0.15</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2019-04-20T07:17:04Z</updated>
<entry>
<title>rxrpc: Fix client call connect/disconnect race</title>
<updated>2019-04-20T07:17:04Z</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2019-03-08T12:48:39Z</published>
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<id>urn:sha1:4fb70c2107e99b897d68b0bd820bebad6e5b1614</id>
<content type='text'>
[ Upstream commit 930c9f9125c85b5134b3e711bc252ecc094708e3 ]

rxrpc_disconnect_client_call() reads the call's connection ID protocol
value (call-&gt;cid) as part of that function's variable declarations.  This
is bad because it's not inside the locked section and so may race with
someone granting use of the channel to the call.

This manifests as an assertion failure (see below) where the call in the
presumed channel (0 because call-&gt;cid wasn't set when we read it) doesn't
match the call attached to the channel we were actually granted (if 1, 2 or
3).

Fix this by moving the read and dependent calculations inside of the
channel_lock section.  Also, only set the channel number and pointer
variables if cid is not zero (ie. unset).

This problem can be induced by injecting an occasional error in
rxrpc_wait_for_channel() before the call to schedule().

Make two further changes also:

 (1) Add a trace for wait failure in rxrpc_connect_call().

 (2) Drop channel_lock before BUG'ing in the case of the assertion failure.

The failure causes a trace akin to the following:

rxrpc: Assertion failed - 18446612685268945920(0xffff8880beab8c00) == 18446612685268621312(0xffff8880bea69800) is false
------------[ cut here ]------------
kernel BUG at net/rxrpc/conn_client.c:824!
...
RIP: 0010:rxrpc_disconnect_client_call+0x2bf/0x99d
...
Call Trace:
 rxrpc_connect_call+0x902/0x9b3
 ? wake_up_q+0x54/0x54
 rxrpc_new_client_call+0x3a0/0x751
 ? rxrpc_kernel_begin_call+0x141/0x1bc
 ? afs_alloc_call+0x1b5/0x1b5
 rxrpc_kernel_begin_call+0x141/0x1bc
 afs_make_call+0x20c/0x525
 ? afs_alloc_call+0x1b5/0x1b5
 ? __lock_is_held+0x40/0x71
 ? lockdep_init_map+0xaf/0x193
 ? lockdep_init_map+0xaf/0x193
 ? __lock_is_held+0x40/0x71
 ? yfs_fs_fetch_data+0x33b/0x34a
 yfs_fs_fetch_data+0x33b/0x34a
 afs_fetch_data+0xdc/0x3b7
 afs_read_dir+0x52d/0x97f
 afs_dir_iterate+0xa0/0x661
 ? iterate_dir+0x63/0x141
 iterate_dir+0xa2/0x141
 ksys_getdents64+0x9f/0x11b
 ? filldir+0x111/0x111
 ? do_syscall_64+0x3e/0x1a0
 __x64_sys_getdents64+0x16/0x19
 do_syscall_64+0x7d/0x1a0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 45025bceef17 ("rxrpc: Improve management and caching of client connection objects")
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Reviewed-by: Marc Dionne &lt;marc.dionne@auristor.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>afs: Fix race in async call refcounting</title>
<updated>2019-01-17T15:17:28Z</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2019-01-10T15:40:50Z</published>
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<id>urn:sha1:34fa47612bfe5d7de7fcaf658a6952b6aeec3b13</id>
<content type='text'>
There's a race between afs_make_call() and afs_wake_up_async_call() in the
case that an error is returned from rxrpc_kernel_send_data() after it has
queued the final packet.

afs_make_call() will try and clean up the mess, but the call state may have
been moved on thereby causing afs_process_async_call() to also try and to
delete the call.

Fix this by:

 (1) Getting an extra ref for an asynchronous call for the call itself to
     hold.  This makes sure the call doesn't evaporate on us accidentally
     and will allow the call to be retained by the caller in a future
     patch.  The ref is released on leaving afs_make_call() or
     afs_wait_for_call_to_complete().

 (2) In the event of an error from rxrpc_kernel_send_data():

     (a) Don't set the call state to AFS_CALL_COMPLETE until *after* the
     	 call has been aborted and ended.  This prevents
     	 afs_deliver_to_call() from doing anything with any notifications
     	 it gets.

     (b) Explicitly end the call immediately to prevent further callbacks.

     (c) Cancel any queued async_work and wait for the work if it's
     	 executing.  This allows us to be sure the race won't recur when we
     	 change the state.  We put the work queue's ref on the call if we
     	 managed to cancel it.

     (d) Put the call's ref that we got in (1).  This belongs to us as long
     	 as the call is in state AFS_CALL_CL_REQUESTING.

Fixes: 341f741f04be ("afs: Refcount the afs_call struct")
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs</title>
<updated>2019-01-03T00:35:23Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-01-03T00:35:23Z</published>
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<id>urn:sha1:e6b92572808467f35fd159d47c45b650de29e722</id>
<content type='text'>
Pull NFS client updates from Anna Schumaker:
 "Stable bugfixes:
   - xprtrdma: Yet another double DMA-unmap # v4.20

  Features:
   - Allow some /proc/sys/sunrpc entries without CONFIG_SUNRPC_DEBUG
   - Per-xprt rdma receive workqueues
   - Drop support for FMR memory registration
   - Make port= mount option optional for RDMA mounts

  Other bugfixes and cleanups:
   - Remove unused nfs4_xdev_fs_type declaration
   - Fix comments for behavior that has changed
   - Remove generic RPC credentials by switching to 'struct cred'
   - Fix crossing mountpoints with different auth flavors
   - Various xprtrdma fixes from testing and auditing the close code
   - Fixes for disconnect issues when using xprtrdma with krb5
   - Clean up and improve xprtrdma trace points
   - Fix NFS v4.2 async copy reboot recovery"

* tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (63 commits)
  sunrpc: convert to DEFINE_SHOW_ATTRIBUTE
  sunrpc: Add xprt after nfs4_test_session_trunk()
  sunrpc: convert unnecessary GFP_ATOMIC to GFP_NOFS
  sunrpc: handle ENOMEM in rpcb_getport_async
  NFS: remove unnecessary test for IS_ERR(cred)
  xprtrdma: Prevent leak of rpcrdma_rep objects
  NFSv4.2 fix async copy reboot recovery
  xprtrdma: Don't leak freed MRs
  xprtrdma: Add documenting comment for rpcrdma_buffer_destroy
  xprtrdma: Replace outdated comment for rpcrdma_ep_post
  xprtrdma: Update comments in frwr_op_send
  SUNRPC: Fix some kernel doc complaints
  SUNRPC: Simplify defining common RPC trace events
  NFS: Fix NFSv4 symbolic trace point output
  xprtrdma: Trace mapping, alloc, and dereg failures
  xprtrdma: Add trace points for calls to transport switch methods
  xprtrdma: Relocate the xprtrdma_mr_map trace points
  xprtrdma: Clean up of xprtrdma chunk trace points
  xprtrdma: Remove unused fields from rpcrdma_ia
  xprtrdma: Cull dprintk() call sites
  ...
</content>
</entry>
<entry>
<title>Merge tag 'nfsd-4.21' of git://linux-nfs.org/~bfields/linux</title>
<updated>2019-01-03T00:21:50Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-01-03T00:21:50Z</published>
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<id>urn:sha1:e45428a436765fcd154d461a2739b5640916dc00</id>
<content type='text'>
Pull nfsd updates from Bruce Fields:
 "Thanks to Vasily Averin for fixing a use-after-free in the
  containerized NFSv4.2 client, and cleaning up some convoluted
  backchannel server code in the process.

  Otherwise, miscellaneous smaller bugfixes and cleanup"

* tag 'nfsd-4.21' of git://linux-nfs.org/~bfields/linux: (25 commits)
  nfs: fixed broken compilation in nfs_callback_up_net()
  nfs: minor typo in nfs4_callback_up_net()
  sunrpc: fix debug message in svc_create_xprt()
  sunrpc: make visible processing error in bc_svc_process()
  sunrpc: remove unused xpo_prep_reply_hdr callback
  sunrpc: remove svc_rdma_bc_class
  sunrpc: remove svc_tcp_bc_class
  sunrpc: remove unused bc_up operation from rpc_xprt_ops
  sunrpc: replace svc_serv-&gt;sv_bc_xprt by boolean flag
  sunrpc: use-after-free in svc_process_common()
  sunrpc: use SVC_NET() in svcauth_gss_* functions
  nfsd: drop useless LIST_HEAD
  lockd: Show pid of lockd for remote locks
  NFSD remove OP_CACHEME from 4.2 op_flags
  nfsd: Return EPERM, not EACCES, in some SETATTR cases
  sunrpc: fix cache_head leak due to queued request
  nfsd: clean up indentation, increase indentation in switch statement
  svcrdma: Optimize the logic that selects the R_key to invalidate
  nfsd: fix a warning in __cld_pipe_upcall()
  nfsd4: fix crash on writing v4_end_grace before nfsd startup
  ...
</content>
</entry>
<entry>
<title>xprtrdma: Prevent leak of rpcrdma_rep objects</title>
<updated>2019-01-02T17:05:19Z</updated>
<author>
<name>Chuck Lever</name>
<email>chuck.lever@oracle.com</email>
</author>
<published>2018-12-07T16:11:44Z</published>
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<id>urn:sha1:07e10308ee5da8e6132e0b737ece1c99dd651fb6</id>
<content type='text'>
If a reply has been processed but the RPC is later retransmitted
anyway, the req-&gt;rl_reply field still contains the only pointer to
the old rpcrdma rep. When the next reply comes in, the reply handler
will stomp on the rl_reply field, leaking the old rep.

A trace event is added to capture such leaks.

This problem seems to be worsened by the restructuring of the RPC
Call path in v4.20. Fully addressing this issue will require at
least a re-architecture of the disconnect logic, which is not
appropriate during -rc.

Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
</content>
</entry>
<entry>
<title>SUNRPC: Simplify defining common RPC trace events</title>
<updated>2019-01-02T17:05:18Z</updated>
<author>
<name>Chuck Lever</name>
<email>chuck.lever@oracle.com</email>
</author>
<published>2018-12-19T16:00:16Z</published>
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<id>urn:sha1:dc5820bd21d84ee34770b0a1e2fca9378f8f7456</id>
<content type='text'>
Clean up, no functional change is expected.

Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
</content>
</entry>
<entry>
<title>xprtrdma: Trace mapping, alloc, and dereg failures</title>
<updated>2019-01-02T17:05:18Z</updated>
<author>
<name>Chuck Lever</name>
<email>chuck.lever@oracle.com</email>
</author>
<published>2018-12-19T16:00:06Z</published>
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<id>urn:sha1:53b2c1cb9b3cd901a200ddbbf08c77eabf1ab3e9</id>
<content type='text'>
These are rare, but can be helpful at tracking down DMAR and other
problems.

Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
</content>
</entry>
<entry>
<title>xprtrdma: Add trace points for calls to transport switch methods</title>
<updated>2019-01-02T17:05:18Z</updated>
<author>
<name>Chuck Lever</name>
<email>chuck.lever@oracle.com</email>
</author>
<published>2018-12-19T16:00:00Z</published>
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<id>urn:sha1:395069fc37e7a76280b176c0327d1ead6ca29838</id>
<content type='text'>
Name them "trace_xprtrdma_op_*" so they can be easily enabled as a
group. No trace point is added where the generic layer already has
observability.

Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
</content>
</entry>
<entry>
<title>xprtrdma: Clean up of xprtrdma chunk trace points</title>
<updated>2019-01-02T17:05:18Z</updated>
<author>
<name>Chuck Lever</name>
<email>chuck.lever@oracle.com</email>
</author>
<published>2018-12-19T15:59:49Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=aba11831794356ff58da69de46a125e6335eb9ca'/>
<id>urn:sha1:aba11831794356ff58da69de46a125e6335eb9ca</id>
<content type='text'>
The chunk-related trace points capture nearly the same information
as the MR-related trace points.

Also, rename them so globbing can be used to enable or disable
these trace points more easily.

Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
</content>
</entry>
<entry>
<title>xprtrdma: Refactor Receive accounting</title>
<updated>2019-01-02T17:05:16Z</updated>
<author>
<name>Chuck Lever</name>
<email>chuck.lever@oracle.com</email>
</author>
<published>2018-12-19T15:58:24Z</published>
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<id>urn:sha1:6ceea36890a01aa626ce08487eecc5fb43e749b1</id>
<content type='text'>
Clean up: Divide the work cleanly:

- rpcrdma_wc_receive is responsible only for RDMA Receives
- rpcrdma_reply_handler is responsible only for RPC Replies
- the posted send and receive counts both belong in rpcrdma_ep

Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
</content>
</entry>
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