In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-nfs@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

svcrdma needs 259 pages allocated to receive 1MB NFSv4.0 WRITE requests:

 - 1 page for the transport header and head iovec
 - 256 pages for the data payload
 - 1 page for the trailing GETATTR request (since NFSD XDR decoding
   does not look for a tail iovec, the GETATTR is stuck at the end
   of the rqstp->rq_arg.pages list)
 - 1 page for building the reply xdr_buf

But RPCSVC_MAXPAGES is already 259 (on x86_64). The problem is that
svc_alloc_arg never allocates that many pages. To address this:

1. The final element of rq_pages always points to NULL. To
   accommodate up to 259 pages in rq_pages, add an extra element
   to rq_pages for the array termination sentinel.

2. Adjust the calculation of "pages" to match how RPCSVC_MAXPAGES
   is calculated, so it can go up to 259. Bruce noted that the
   calculation assumes sv_max_mesg is a multiple of PAGE_SIZE,
   which might not always be true. I didn't change this assumption.

3. Change the loop boundaries to allow 259 pages to be allocated.

Additional clean-up: WARN_ON_ONCE adds an extra conditional branch,
which is basically never taken. And there's no need to dump the
stack here because svc_alloc_arg has only one caller.

Keeping that NULL "array termination sentinel"; there doesn't appear to
be any code that depends on it, only code in nfsd_splice_actor() which
needs the 259th element to be initialized to *something*.  So it's
possible we could just keep the array at 259 elements and drop that
final NULL, but we're being conservative for now.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The inet6addr_chain is an atomic notifier chain, so we can't call
anything that might sleep (like lock_sock)... instead of closing the
socket from svc_age_temp_xprts_now (which is called by the notifier
function), just have the rpc service threads do it instead.

Cc: stable@vger.kernel.org
Fixes: c3d4879e "sunrpc: Add a function to close..."
Signed-off-by: NScott Mayhew <smayhew@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This fixes the following panic that can occur with NFSoRDMA.

general protection fault: 0000 [#1] SMP
Modules linked in: rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi
scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp
scsi_tgt ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm
mlx5_ib ib_core intel_powerclamp coretemp kvm_intel kvm sg ioatdma
ipmi_devintf ipmi_ssif dcdbas iTCO_wdt iTCO_vendor_support pcspkr
irqbypass sb_edac shpchp dca crc32_pclmul ghash_clmulni_intel edac_core
lpc_ich aesni_intel lrw gf128mul glue_helper ablk_helper mei_me mei
ipmi_si cryptd wmi ipmi_msghandler acpi_pad acpi_power_meter nfsd
auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod
crc_t10dif crct10dif_generic mgag200 i2c_algo_bit drm_kms_helper
syscopyarea sysfillrect sysimgblt ahci fb_sys_fops ttm libahci mlx5_core
tg3 crct10dif_pclmul drm crct10dif_common
ptp i2c_core libata crc32c_intel pps_core fjes dm_mirror dm_region_hash
dm_log dm_mod
CPU: 1 PID: 120 Comm: kworker/1:1 Not tainted 3.10.0-514.el7.x86_64 #1
Hardware name: Dell Inc. PowerEdge R320/0KM5PX, BIOS 2.4.2 01/29/2015
Workqueue: events check_lifetime
task: ffff88031f506dd0 ti: ffff88031f584000 task.ti: ffff88031f584000
RIP: 0010:[<ffffffff8168d847>]  [<ffffffff8168d847>]
_raw_spin_lock_bh+0x17/0x50
RSP: 0018:ffff88031f587ba8  EFLAGS: 00010206
RAX: 0000000000020000 RBX: 20041fac02080072 RCX: ffff88031f587fd8
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 20041fac02080072
RBP: ffff88031f587bb0 R08: 0000000000000008 R09: ffffffff8155be77
R10: ffff880322a59b00 R11: ffffea000bf39f00 R12: 20041fac02080072
R13: 000000000000000d R14: ffff8800c4fbd800 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff880322a40000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3c52d4547e CR3: 00000000019ba000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
20041fac02080002 ffff88031f587bd0 ffffffff81557830 20041fac02080002
ffff88031f587c78 ffff88031f587c40 ffffffff8155ae08 000000010157df32
0000000800000001 ffff88031f587c20 ffffffff81096acb ffffffff81aa37d0
Call Trace:
[<ffffffff81557830>] lock_sock_nested+0x20/0x50
[<ffffffff8155ae08>] sock_setsockopt+0x78/0x940
[<ffffffff81096acb>] ? lock_timer_base.isra.33+0x2b/0x50
[<ffffffff8155397d>] kernel_setsockopt+0x4d/0x50
[<ffffffffa0386284>] svc_age_temp_xprts_now+0x174/0x1e0 [sunrpc]
[<ffffffffa03b681d>] nfsd_inetaddr_event+0x9d/0xd0 [nfsd]
[<ffffffff81691ebc>] notifier_call_chain+0x4c/0x70
[<ffffffff810b687d>] __blocking_notifier_call_chain+0x4d/0x70
[<ffffffff810b68b6>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff815e8538>] __inet_del_ifa+0x168/0x2d0
[<ffffffff815e8cef>] check_lifetime+0x25f/0x270
[<ffffffff810a7f3b>] process_one_work+0x17b/0x470
[<ffffffff810a8d76>] worker_thread+0x126/0x410
[<ffffffff810a8c50>] ? rescuer_thread+0x460/0x460
[<ffffffff810b052f>] kthread+0xcf/0xe0
[<ffffffff810b0460>] ? kthread_create_on_node+0x140/0x140
[<ffffffff81696418>] ret_from_fork+0x58/0x90
[<ffffffff810b0460>] ? kthread_create_on_node+0x140/0x140
Code: ca 75 f1 5d c3 0f 1f 80 00 00 00 00 eb d9 66 0f 1f 44 00 00 0f 1f
44 00 00 55 48 89 e5 53 48 89 fb e8 7e 04 a0 ff b8 00 00 02 00 <f0> 0f
c1 03 89 c2 c1 ea 10 66 39 c2 75 03 5b 5d c3 83 e2 fe 0f
RIP  [<ffffffff8168d847>] _raw_spin_lock_bh+0x17/0x50
RSP <ffff88031f587ba8>
Signed-off-by: NScott Mayhew <smayhew@redhat.com>
Fixes: c3d4879e ("sunrpc: Add a function to close temporary transports immediately")
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Allow the user to limit the number of requests serviced through a single
connection, to help prevent faster clients from starving slower clients.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Dropping and/or deferring requests has an impact on performance. Let's
make sure we can trace those events.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Add a tracepoint to track when the processing of incoming RPC data gets
deferred due to out-of-space issues on the outgoing transport.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The spec allows backchannels for multiple clients to share the same tcp
connection.  When that happens, we need to use the same xprt for all of
them.  Similarly, we need the same xps.

This fixes list corruption introduced by the multipath code.

Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NTrond Myklebust <trondmy@primarydata.com>

This should fix failures like:

	# rpc.nfsd --rdma
	rpc.nfsd: Unable to request RDMA services: Protocol not supported
Reported-by: NSteve Dickson <steved@redhat.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Add a function svc_age_temp_xprts_now() to close temporary transports
whose xpt_local matches the address passed in server_addr immediately
instead of waiting for them to be closed by the timer function.

The function is intended to be used by notifier_blocks that will be
added to nfsd and lockd that will run when an ip address is deleted.

This will eliminate the ACK storms and client hangs that occur in
HA-NFS configurations where nfsd & lockd is left running on the cluster
nodes all the time and the NFS 'service' is migrated back and forth
within a short timeframe.
Signed-off-by: NScott Mayhew <smayhew@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

For now, all services use svc_xprt_do_enqueue, but once we add
workqueue-based service support, we'll need to do something different.
Signed-off-by: NShirley Ma <shirley.ma@oracle.com>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The BKL is completely out of the picture in the lockd and sunrpc code
these days. Update the antiquated comments that refer to it.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...move the WARN_ON_ONCE inside the following if block since they use
the same condition.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

These were useful when I was tracking down a race condition between
svc_xprt_do_enqueue and svc_get_next_xprt.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Testing has shown that the pool->sp_lock can be a bottleneck on a busy
server. Every time data is received on a socket, the server must take
that lock in order to dequeue a thread from the sp_threads list.

Address this problem by eliminating the sp_threads list (which contains
threads that are currently idle) and replacing it with a RQ_BUSY flag in
svc_rqst. This allows us to walk the sp_all_threads list under the
rcu_read_lock and find a suitable thread for the xprt by doing a
test_and_set_bit.

Note that we do still have a potential atomicity problem however with
this approach.  We don't want svc_xprt_do_enqueue to set the
rqst->rq_xprt pointer unless a test_and_set_bit of RQ_BUSY returned
zero (which indicates that the thread was idle). But, by the time we
check that, the bit could be flipped by a waking thread.

To address this, we acquire a new per-rqst spinlock (rq_lock) and take
that before doing the test_and_set_bit. If that returns false, then we
can set rq_xprt and drop the spinlock. Then, when the thread wakes up,
it must set the bit under the same spinlock and can trust that if it was
already set then the rq_xprt is also properly set.

With this scheme, the case where we have an idle thread no longer needs
to take the highly contended pool->sp_lock at all, and that removes the
bottleneck.

That still leaves one issue: What of the case where we walk the whole
sp_all_threads list and don't find an idle thread? Because the search is
lockess, it's possible for the queueing to race with a thread that is
going to sleep. To address that, we queue the xprt and then search again.

If we find an idle thread at that point, we can't attach the xprt to it
directly since that might race with a different thread waking up and
finding it.  All we can do is wake the idle thread back up and let it
attempt to find the now-queued xprt.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NChris Worley <chris.worley@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In a later patch, we'll be removing some spinlocking around the socket
and thread queueing code in order to fix some contention problems. At
that point, the stats counters will no longer be protected by the
sp_lock.

Change the counters to atomic_long_t fields, except for the
"sockets_queued" counter which will still be manipulated under a
spinlock.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NChris Worley <chris.worley@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The way that svc_wake_up works is a bit inefficient. It walks all of the
available pools for a service and either wakes up a task in each one or
sets the SP_TASK_PENDING flag in each one.

When svc_wake_up is called, there is no need to wake up more than one
thread to do this work. In practice, only lockd currently uses this
function and it's single threaded anyway. Thus, this just boils down to
doing a wake up of a thread in pool 0 or setting a single flag.

Eliminate the for loop in this function and change it to just operate on
pool 0. Also update the comments that sit above it and get rid of some
code that has been commented out for years now.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In a later patch, we'll want to be able to handle this flag without
holding the sp_lock. Change this field to an unsigned long flags
field, and declare a new flag in it that can be managed with atomic
bitops.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In a later patch, we're going to need some atomic bit flags. Since that
field will need to be an unsigned long, we mitigate that space
consumption by migrating some other bitflags to the new field. Start
with the rq_secure flag.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

All it does is indicate whether a xprt has already been deleted from
a list or not, which is unnecessary since we use list_del_init and it's
always set and checked under the sv_lock anyway.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...just around svc_send, svc_recv and svc_process for now.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

current_task appears to be x86-only, oops.

Let's just delete this check entirely:

Any developer that adds a new user without setting rq_task will get a
crash the first time they test it.  I also don't think there are
normally any important locks held here, and I can't see any other reason
why killing a server thread would bring the whole box down.

So the effort to fail gracefully here looks like overkill.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Fixes: 983c6844 "SUNRPC: get rid of the request wait queue"
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Just move the transport locking out of the spin lock protected area
altogether.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We should definitely not be exiting svc_get_next_xprt() with the
thread enqueued. Fix this by ensuring that we fall through to
the dequeue.
Also move the test itself outside the spin lock protected section.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We're always _only_ waking up tasks from within the sp_threads list, so
we know that they are enqueued and alive. The rq_wait waitqueue is just
a distraction with extra atomic semantics.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We already determined that there was enough wspace when we
called svc_xprt_enqueue.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Ensure that all calls to svc_xprt_enqueue() except svc_xprt_received()
check the value of XPT_BUSY, before attempting to grab spinlocks etc.
This is to avoid situations such as the following "perf" trace,
which shows heavy contention on the pool spinlock:

    54.15%            nfsd  [kernel.kallsyms]        [k] _raw_spin_lock_bh
                      |
                      --- _raw_spin_lock_bh
                         |
                         |--71.43%-- svc_xprt_enqueue
                         |          |
                         |          |--50.31%-- svc_reserve
                         |          |
                         |          |--31.35%-- svc_xprt_received
                         |          |
                         |          |--18.34%-- svc_tcp_data_ready
...
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

After this we can handle for example getattr of very large ACLs.

Read, readdir, readlink are still special cases with their own limits.

Also we can't handle a new operation starting close to the end of a
page.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If the accept() call fails, we need to put the module reference.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

An NFS/RDMA client's source port is meaningless for RDMA transports.
The transport layer typically sets the source port value on the
connection to a random ephemeral port.

Currently, NFS server administrators must specify the "insecure"
export option to enable clients to access exports via RDMA.

But this means NFS clients can access such an export via IP using an
ephemeral port, which may not be desirable.

This patch eliminates the need to specify the "insecure" export
option to allow NFS/RDMA clients access to an export.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=250Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Mark functions as static in net/sunrpc/svc_xprt.c because they are not
used outside this file.

This eliminates the following warning in net/sunrpc/svc_xprt.c:
net/sunrpc/svc_xprt.c:574:5: warning: no previous prototype for ‘svc_alloc_arg’ [-Wmissing-prototypes]
net/sunrpc/svc_xprt.c:615:18: warning: no previous prototype for ‘svc_get_next_xprt’ [-Wmissing-prototypes]
net/sunrpc/svc_xprt.c:694:6: warning: no previous prototype for ‘svc_add_new_temp_xprt’ [-Wmissing-prototypes]
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Mark functions as static in net/sunrpc/svc_xprt.c because they are not
used outside this file.

This eliminates the following warning in net/sunrpc/svc_xprt.c:
net/sunrpc/svc_xprt.c:574:5: warning: no previous prototype for ‘svc_alloc_arg’ [-Wmissing-prototypes]
net/sunrpc/svc_xprt.c:615:18: warning: no previous prototype for ‘svc_get_next_xprt’ [-Wmissing-prototypes]
net/sunrpc/svc_xprt.c:694:6: warning: no previous prototype for ‘svc_add_new_temp_xprt’ [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rewrite server shutdown to remove the assumption that there are no
longer any threads running (no longer true, for example, when shutting
down the service in one network namespace while it's still running in
others).

Do that by doing what we'd do in normal circumstances: just CLOSE each
socket, then enqueue it.

Since there may not be threads to handle the resulting queued xprts,
also run a simplified version of the svc_recv() loop run by a server to
clean up any closed xprts afterwards.

Cc: stable@kernel.org
Tested-by: NJason Tibbitts <tibbs@math.uh.edu>
Tested-by: NPaweł Sikora <pawel.sikora@agmk.net>
Acked-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

svc_age_temp_xprts expires xprts in a two-step process: first it takes
the sv_lock and moves the xprts to expire off their server-wide list
(sv_tempsocks or sv_permsocks) to a local list.  Then it drops the
sv_lock and enqueues and puts each one.

I see no reason for this: svc_xprt_enqueue() will take sp_lock, but the
sv_lock and sp_lock are not otherwise nested anywhere (and documentation
at the top of this file claims it's correct to nest these with sp_lock
inside.)

Cc: stable@kernel.org
Tested-by: NJason Tibbitts <tibbs@math.uh.edu>
Tested-by: NPaweł Sikora <pawel.sikora@agmk.net>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>