linux-toradex.git/include/linux/sunrpc/clnt.h, branch v5.17-rc5

SUNRPC: Per-rpc_clnt task PIDs

2021-10-10T09:05:54+00:00

The current range of RPC task PIDs is 0..65535. That's not adequate
for distinguishing tasks across multiple rpc_clnts running high
throughput workloads.

To help relieve this situation and to reduce the bottleneck of
having a single atomic for assigning all RPC task PIDs, assign task
PIDs per rpc_clnt.

Signed-off-by: Chuck Lever 
Signed-off-by: Trond Myklebust

SUNRPC enforce creation of no more than max_connect xprts

2021-08-27T20:37:29+00:00

If we are adding new transports via rpc_clnt_test_and_add_xprt()
then check if we've reached the limit. Currently only pnfs path
adds transports via that function but this is done in
preparation when the client would add new transports when
session trunking is detected. A warning is logged if the
limit is reached.

Signed-off-by: Olga Kornievskaia 
Signed-off-by: Anna Schumaker

SUNRPC: Convert rpc_client refcount to use refcount_t

2021-08-09T20:57:04+00:00

There are now tools in the refcount library that allow us to convert the
client shutdown code.

Reported-by: Xiyu Yang 
Signed-off-by: Trond Myklebust 
Signed-off-by: Anna Schumaker

sunrpc: Create per-rpc_clnt sysfs kobjects

2021-07-08T18:03:23+00:00

These will eventually have files placed under them for sysfs operations.

Signed-off-by: Anna Schumaker 
Signed-off-by: Olga Kornievskaia 
Signed-off-by: Trond Myklebust

NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION

2020-04-28T19:58:38+00:00

Currently, if the client sends BIND_CONN_TO_SESSION with
NFS4_CDFC4_FORE_OR_BOTH but only gets NFS4_CDFS4_FORE back it ignores
that it wasn't able to enable a backchannel.

To make sure, the client sends BIND_CONN_TO_SESSION as the first
operation on the connections (ie., no other session compounds haven't
been sent before), and if the client's request to bind the backchannel
is not satisfied, then reset the connection and retry.

Cc: stable@vger.kernel.org
Signed-off-by: Olga Kornievskaia 
Signed-off-by: Trond Myklebust

SUNRPC: defer slow parts of rpc_free_client() to a workqueue.

2020-04-28T19:58:38+00:00

The rpciod workqueue is on the write-out path for freeing dirty memory,
so it is important that it never block waiting for memory to be
allocated - this can lead to a deadlock.

rpc_execute() - which is often called by an rpciod work item - calls
rcp_task_release_client() which can lead to rpc_free_client().

rpc_free_client() makes two calls which could potentially block wating
for memory allocation.

rpc_clnt_debugfs_unregister() calls into debugfs and will block while
any of the debugfs files are being accessed.  In particular it can block
while any of the 'open' methods are being called and all of these use
malloc for one thing or another.  So this can deadlock if the memory
allocation waits for NFS to complete some writes via rpciod.

rpc_clnt_remove_pipedir() can take the inode_lock() and while it isn't
obvious that memory allocations can happen while the lock it held, it is
safer to assume they might and to not let rpciod call
rpc_clnt_remove_pipedir().

So this patch moves these two calls (together with the final kfree() and
rpciod_down()) into a work-item to be run from the system work-queue.
rpciod can continue its important work, and the final stages of the free
can happen whenever they happen.

I have seen this deadlock on a 4.12 based kernel where debugfs used
synchronize_srcu() when removing objects.  synchronize_srcu() requires a
workqueue and there were no free workther threads and none could be
allocated.  While debugsfs no longer uses SRCU, I believe the deadlock
is still possible.

Signed-off-by: NeilBrown 
Signed-off-by: Trond Myklebust

Merge tag 'nfsd-5.5' of git://linux-nfs.org/~bfields/linux

2019-12-08T00:56:00+00:00

Pull nfsd updates from Bruce Fields:
 "This is a relatively quiet cycle for nfsd, mainly various bugfixes.

  Possibly most interesting is Trond's fixes for some callback races
  that were due to my incomplete understanding of rpc client shutdown.
  Unfortunately at the last minute I've started noticing a new
  intermittent failure to send callbacks. As the logic seems basically
  correct, I'm leaving Trond's patches in for now, and hope to find a
  fix in the next week so I don't have to revert those patches"

* tag 'nfsd-5.5' of git://linux-nfs.org/~bfields/linux: (24 commits)
  nfsd: depend on CRYPTO_MD5 for legacy client tracking
  NFSD fixing possible null pointer derefering in copy offload
  nfsd: check for EBUSY from vfs_rmdir/vfs_unink.
  nfsd: Ensure CLONE persists data and metadata changes to the target file
  SUNRPC: Fix backchannel latency metrics
  nfsd: restore NFSv3 ACL support
  nfsd: v4 support requires CRYPTO_SHA256
  nfsd: Fix cld_net->cn_tfm initialization
  lockd: remove __KERNEL__ ifdefs
  sunrpc: remove __KERNEL__ ifdefs
  race in exportfs_decode_fh()
  nfsd: Drop LIST_HEAD where the variable it declares is never used.
  nfsd: document callback_wq serialization of callback code
  nfsd: mark cb path down on unknown errors
  nfsd: Fix races between nfsd4_cb_release() and nfsd4_shutdown_callback()
  nfsd: minor 4.1 callback cleanup
  SUNRPC: Fix svcauth_gss_proxy_init()
  SUNRPC: Trace gssproxy upcall results
  sunrpc: fix crash when cache_head become valid before update
  nfsd: remove private bin2hex implementation
  ...

sunrpc: remove KERNEL ifdefs

2019-11-12T16:43:29+00:00

Remove the __KERNEL__ ifdefs from the non-UAPI sunrpc headers,
as those can't be included from user space programs.

Signed-off-by: Christoph Hellwig 
Signed-off-by: J. Bruce Fields

NFSv4.1: Don't rebind to the same source port when reconnecting to the server

2019-11-04T02:28:45+00:00

NFSv2, v3 and NFSv4 servers often have duplicate replay caches that look
at the source port when deciding whether or not an RPC call is a replay
of a previous call. This requires clients to perform strange TCP gymnastics
in order to ensure that when they reconnect to the server, they bind
to the same source port.

NFSv4.1 and NFSv4.2 have sessions that provide proper replay semantics,
that do not look at the source port of the connection. This patch therefore
ensures they can ignore the rebind requirement.

Signed-off-by: Trond Myklebust

SUNRPC: Fix up backchannel slot table accounting

2019-07-18T05:12:59+00:00

Add a per-transport maximum limit in the socket case, and add
helpers to allow the NFSv4 code to discover that limit.

Signed-off-by: Trond Myklebust