Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng->ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Kernel source files need not include <linux/kconfig.h> explicitly
because the top Makefile forces to include it with:

  -include $(srctree)/include/linux/kconfig.h

This commit removes explicit includes except the following:

  * arch/s390/include/asm/facilities_src.h
  * tools/testing/radix-tree/linux/kernel.h

These two are used for host programs.

Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the lockd service fails to start up then we need to be sure that the
notifier blocks are not registered, otherwise a subsequent start of the
service could cause the same notifier to be registered twice, leading to
soft lockups.
Signed-off-by: NScott Mayhew <smayhew@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 0751ddf7 "lockd: Register callbacks on the inetaddr_chain..."
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

it's not needed for file_operations of inodes located on fs defined
in the hosting module and for file_operations that go into procfs.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The nlmsvc_binding structure is never modified, so declare it as const.

Done with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Use to_delayed_work() instead of open-coding it.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Register callbacks on inetaddr_chain and inet6addr_chain to trigger
cleanup of lockd transport sockets when an ip address is deleted.
Signed-off-by: NScott Mayhew <smayhew@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Currently we have reference-counted per-net NSM RPC client
which created on the first monitor request and destroyed
after the last unmonitor request. It's needed because
RPC client need to know 'utsname()->nodename', but utsname()
might be NULL when nsm_unmonitor() called.

So instead of holding the rpc client we could just save nodename
in struct nlm_host and pass it to the rpc_create().
Thus ther is no need in keeping rpc client until last
unmonitor request. We could create separate RPC clients
for each monitor/unmonitor requests.
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Instead of having users check for FL_POSIX or FL_FLOCK to call the correct
locks API function, use the check within locks_lock_inode_wait().  This
allows for some later cleanup.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>

Commit cb7323ff ("lockd: create and use per-net NSM
 RPC clients on MON/UNMON requests") introduced per-net
NSM RPC clients. Unfortunately this doesn't make any sense
without per-net nsm_handle.

E.g. the following scenario could happen
Two hosts (X and Y) in different namespaces (A and B) share
the same nsm struct.

1. nsm_monitor(host_X) called => NSM rpc client created,
	nsm->sm_monitored bit set.
2. nsm_mointor(host-Y) called => nsm->sm_monitored already set,
	we just exit. Thus in namespace B ln->nsm_clnt == NULL.
3. host X destroyed => nsm->sm_count decremented to 1
4. host Y destroyed => nsm_unmonitor() => nsm_mon_unmon() => NULL-ptr
	dereference of *ln->nsm_clnt

So this could be fixed by making per-net nsm_handles list,
instead of global. Thus different net namespaces will not be able
share the same nsm_handle.
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

NLM locks don't conflict with NFSv4 share reservations, so we're not
going to learn anything new by watiting for them.

They do conflict with NFSv4 locks and with delegations.
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>

In later patches we'll need to abstract out more operations on a
per-service level, besides sv_shutdown and sv_function.

Declare a new svc_serv_ops struct to hold these operations, and move
sv_shutdown into this struct.
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>

Commit f895b252 ("sunrpc: eliminate RPC_DEBUG") introduced
use of IS_ENABLED() in a uapi header which leads to a build
failure for userspace apps trying to use <linux/nfsd/debug.h>:

   linux/nfsd/debug.h:18:15: error: missing binary operator before token "("
  #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
                ^

Since this was only used to define NFSD_DEBUG if CONFIG_SUNRPC_DEBUG
is enabled, replace instances of NFSD_DEBUG with CONFIG_SUNRPC_DEBUG.

Cc: stable@vger.kernel.org
Fixes: f895b252 "sunrpc: eliminate RPC_DEBUG"
Signed-off-by: NMark Salter <msalter@redhat.com>
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Fix an Oopsable condition when nsm_mon_unmon is called as part of the
namespace cleanup, which now apparently happens after the utsname
has been freed.

Link: http://lkml.kernel.org/r/20150125220604.090121ae@neptune.homeReported-by: NBruno Prémont <bonbons@linux-vserver.org>
Cc: stable@vger.kernel.org # 3.18
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.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>

We can now add a dedicated spinlock without expanding struct inode.
Change to using that to protect the various i_flctx lists.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Acked-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Acked-by: NChristoph Hellwig <hch@lst.de>

Remove the function nlm_encode_fh() that is not used anywhere.

This was partially found by using a static code analysis program called cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This commit fixes a race whereby nlmclnt_init() first starts the lockd
daemon, and then calls nlm_bind_host() with the expectation that
nlmsvc_timeout has already been initialised. Unfortunately, there is no
no synchronisation between lockd() and lockd_up() to guarantee that this
is the case.

Fix is to move the initialisation of nlmsvc_timeout into lockd_create_svc

Fixes: 9a1b6bf8 ("LOCKD: Don't call utsname()->nodename...")
Cc: Bruce Fields <bfields@fieldses.org>
Cc: stable@vger.kernel.org # 3.10.x
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Currently all svc_create callers pass in NULL for the shutdown parm,
which then gets fixed up to be svc_rpcb_cleanup if the service uses
rpcbind.

Simplify this by instead having the the only caller that requires it
(lockd) pass in svc_rpcb_cleanup and get rid of the special casing.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

LOCKD_DEBUG is always the same value as CONFIG_SUNRPC_DEBUG, so we can
just use it instead.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When lockd can't talk to a remote statd, it'll spew a warning message
to the ring buffer. If the application is really hammering on locks
however, it's possible for that message to spam the logs. Ratelimit it
to minimize the potential for harm.
Reported-by: NIan Collier <imc@cs.ox.ac.uk>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If rpc.statd is restarted, upcalls to monitor hosts can fail with
ECONNREFUSED.  In that case force a lookup of statd's new port and retry the
upcall.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Add a new procfile that will allow a (privileged) userland process to
end the NLM grace period early. The basic idea here will be to have
sm-notify write to this file, if it sent out no NOTIFY requests when
it runs. In that situation, we can generally expect that there will be
no reclaim requests so the grace period can be lifted early.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>

Currently, all of the grace period handling is part of lockd. Eventually
though we'd like to be able to build v4-only servers, at which point
we'll need to put all of this elsewhere.

Move the code itself into fs/nfs_common and have it build a grace.ko
module. Then, rejigger the Kconfig options so that both nfsd and lockd
enable it automatically.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>

As Kinglong points out, the nlm_block->b_fl field is no longer used at
all. Also, vfs_test_lock in the generic locking code will only return
FILE_LOCK_DEFERRED if FL_SLEEP is set, and it isn't here.

The only other place that returns that value is the DLM lock code, but
it only does that in dlm_posix_lock, never in dlm_posix_get.

Remove all of the deferred locking code from the testlock codepath
since it doesn't appear to ever be used anyway.

I do have a small concern that this might cause a behavior change in the
case where you have a block already sitting on the list when the
testlock request comes in, but that looks like it doesn't really work
properly anyway. I think it's best to just pass that down to
vfs_test_lock and let the filesystem report that instead of trying to
infer what's going on with the lock by looking at an existing block.

Cc: cluster-devel@redhat.com
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NKinglong Mee <kinglongmee@gmail.com>

Commit d5b9026a ([PATCH] knfsd: locks: flag NFSv4-owned locks) using
fl_lmops field in file_lock for checking nfsd4 lockowner.

But, commit 1a747ee0 (locks: don't call ->copy_lock methods on return
of conflicting locks) causes the fl_lmops of conflock always be NULL.

Also, commit 0996905f (lockd: posix_test_lock() should not call
locks_copy_lock()) caused the fl_lmops of conflock always be NULL too.

Make sure copy the private information by fl_copy_lock() in struct
file_lock_operations, merge __locks_copy_lock() to fl_copy_lock().

Jeff advice, "Set fl_lmops on conflocks, but don't set fl_ops.
fl_ops are superfluous, since they are callbacks into the filesystem.
There should be no need to bother the filesystem at all with info
in a conflock. But, lock _ownership_ matters for conflocks and that's
indicated by the fl_lmops. So you really do want to copy the fl_lmops
for conflocks I think."

v5: add missing calling of locks_release_private() in nlmsvc_testlock()
v4: only copy fl_lmops for conflock, don't copy fl_ops
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>

This argument is always NULL so don't pass it around.

[jlayton: remove dependencies on previous patches in series]
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>

Nikita Yuschenko reported that booting a kernel with init=/bin/sh and
then nfs mounting without portmap or rpcbind running using a busybox
mount resulted in:

  # mount -t nfs 10.30.130.21:/opt /mnt
  svc: failed to register lockdv1 RPC service (errno 111).
  lockd_up: makesock failed, error=-111
  Unable to handle kernel paging request for data at address 0x00000030
  Faulting instruction address: 0xc055e65c
  Oops: Kernel access of bad area, sig: 11 [#1]
  MPC85xx CDS
  Modules linked in:
  CPU: 0 PID: 1338 Comm: mount Not tainted 3.10.44.cge #117
  task: cf29cea0 ti: cf35c000 task.ti: cf35c000
  NIP: c055e65c LR: c0566490 CTR: c055e648
  REGS: cf35dad0 TRAP: 0300   Not tainted  (3.10.44.cge)
  MSR: 00029000 <CE,EE,ME>  CR: 22442488  XER: 20000000
  DEAR: 00000030, ESR: 00000000

  GPR00: c05606f4 cf35db80 cf29cea0 cf0ded80 cf0dedb8 00000001 1dec3086
  00000000
  GPR08: 00000000 c07b1640 00000007 1dec3086 22442482 100b9758 00000000
  10090ae8
  GPR16: 00000000 000186a5 00000000 00000000 100c3018 bfa46edc 100b0000
  bfa46ef0
  GPR24: cf386ae0 c07834f0 00000000 c0565f88 00000001 cf0dedb8 00000000
  cf0ded80
  NIP [c055e65c] call_start+0x14/0x34
  LR [c0566490] __rpc_execute+0x70/0x250
  Call Trace:
  [cf35db80] [00000080] 0x80 (unreliable)
  [cf35dbb0] [c05606f4] rpc_run_task+0x9c/0xc4
  [cf35dbc0] [c0560840] rpc_call_sync+0x50/0xb8
  [cf35dbf0] [c056ee90] rpcb_register_call+0x54/0x84
  [cf35dc10] [c056f24c] rpcb_register+0xf8/0x10c
  [cf35dc70] [c0569e18] svc_unregister.isra.23+0x100/0x108
  [cf35dc90] [c0569e38] svc_rpcb_cleanup+0x18/0x30
  [cf35dca0] [c0198c5c] lockd_up+0x1dc/0x2e0
  [cf35dcd0] [c0195348] nlmclnt_init+0x2c/0xc8
  [cf35dcf0] [c015bb5c] nfs_start_lockd+0x98/0xec
  [cf35dd20] [c015ce6c] nfs_create_server+0x1e8/0x3f4
  [cf35dd90] [c0171590] nfs3_create_server+0x10/0x44
  [cf35dda0] [c016528c] nfs_try_mount+0x158/0x1e4
  [cf35de20] [c01670d0] nfs_fs_mount+0x434/0x8c8
  [cf35de70] [c00cd3bc] mount_fs+0x20/0xbc
  [cf35de90] [c00e4f88] vfs_kern_mount+0x50/0x104
  [cf35dec0] [c00e6e0c] do_mount+0x1d0/0x8e0
  [cf35df10] [c00e75ac] SyS_mount+0x90/0xd0
  [cf35df40] [c000ccf4] ret_from_syscall+0x0/0x3c

The addition of svc_shutdown_net() resulted in two calls to
svc_rpcb_cleanup(); the second is no longer necessary and crashes when
it calls rpcb_register_call with clnt=NULL.
Reported-by: NNikita Yushchenko <nyushchenko@dev.rtsoft.ru>
Fixes: 679b033d "lockd: ensure we tear down any live sockets when socket creation fails during lockd_up"
Cc: stable@vger.kernel.org
Acked-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This fixes an Oopsable race when starting lockd.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NJeff Layton <jlayton@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>

Replace the ever recurring:
        ts = ktime_get_ts();
        ns = timespec_to_ns(&ts);
with
        ns = ktime_get_ns();
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

This typedef is unnecessary and should just be removed.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are no legitimate users outside of fs/nfsd, so move it there.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The only real user of this header is fs/nfsd/nfsfh.h, so merge the
two.  Various lockѕ source files used it to indirectly get other
sunrpc or nfs headers, so fix those up.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

When building without CONFIG_SYSCTL, the compiler saw an unused
label. This moves the label into the #ifdef it is used under.

fs/lockd/svc.c: In function ‘init_nlm’:
fs/lockd/svc.c:626:1: warning: label ‘err_sysctl’ defined but not used [-Wunused-label]
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We had a Fedora ABRT report with a stack trace like this:

kernel BUG at net/sunrpc/svc.c:550!
invalid opcode: 0000 [#1] SMP
[...]
CPU: 2 PID: 913 Comm: rpc.nfsd Not tainted 3.13.6-200.fc20.x86_64 #1
Hardware name: Hewlett-Packard HP ProBook 4740s/1846, BIOS 68IRR Ver. F.40 01/29/2013
task: ffff880146b00000 ti: ffff88003f9b8000 task.ti: ffff88003f9b8000
RIP: 0010:[<ffffffffa0305fa8>]  [<ffffffffa0305fa8>] svc_destroy+0x128/0x130 [sunrpc]
RSP: 0018:ffff88003f9b9de0  EFLAGS: 00010206
RAX: ffff88003f829628 RBX: ffff88003f829600 RCX: 00000000000041ee
RDX: 0000000000000000 RSI: 0000000000000286 RDI: 0000000000000286
RBP: ffff88003f9b9de8 R08: 0000000000017360 R09: ffff88014fa97360
R10: ffffffff8114ce57 R11: ffffea00051c9c00 R12: ffff88003f829600
R13: 00000000ffffff9e R14: ffffffff81cc7cc0 R15: 0000000000000000
FS:  00007f4fde284840(0000) GS:ffff88014fa80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4fdf5192f8 CR3: 00000000a569a000 CR4: 00000000001407e0
Stack:
 ffff88003f792300 ffff88003f9b9e18 ffffffffa02de02a 0000000000000000
 ffffffff81cc7cc0 ffff88003f9cb000 0000000000000008 ffff88003f9b9e60
 ffffffffa033bb35 ffffffff8131c86c ffff88003f9cb000 ffff8800a5715008
Call Trace:
 [<ffffffffa02de02a>] lockd_up+0xaa/0x330 [lockd]
 [<ffffffffa033bb35>] nfsd_svc+0x1b5/0x2f0 [nfsd]
 [<ffffffff8131c86c>] ? simple_strtoull+0x2c/0x50
 [<ffffffffa033c630>] ? write_pool_threads+0x280/0x280 [nfsd]
 [<ffffffffa033c6bb>] write_threads+0x8b/0xf0 [nfsd]
 [<ffffffff8114efa4>] ? __get_free_pages+0x14/0x50
 [<ffffffff8114eff6>] ? get_zeroed_page+0x16/0x20
 [<ffffffff811dec51>] ? simple_transaction_get+0xb1/0xd0
 [<ffffffffa033c098>] nfsctl_transaction_write+0x48/0x80 [nfsd]
 [<ffffffff811b8b34>] vfs_write+0xb4/0x1f0
 [<ffffffff811c3f99>] ? putname+0x29/0x40
 [<ffffffff811b9569>] SyS_write+0x49/0xa0
 [<ffffffff810fc2a6>] ? __audit_syscall_exit+0x1f6/0x2a0
 [<ffffffff816962e9>] system_call_fastpath+0x16/0x1b
Code: 31 c0 e8 82 db 37 e1 e9 2a ff ff ff 48 8b 07 8b 57 14 48 c7 c7 d5 c6 31 a0 48 8b 70 20 31 c0 e8 65 db 37 e1 e9 f4 fe ff ff 0f 0b <0f> 0b 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55
RIP  [<ffffffffa0305fa8>] svc_destroy+0x128/0x130 [sunrpc]
 RSP <ffff88003f9b9de0>

Evidently, we created some lockd sockets and then failed to create
others. make_socks then returned an error and we tried to tear down the
svc, but svc->sv_permsocks was not empty so we ended up tripping over
the BUG() in svc_destroy().

Fix this by ensuring that we tear down any live sockets we created when
socket creation is going to return an error.

Fixes: 786185b5 (SUNRPC: move per-net operations from...)
Reported-by: NRaphos <raphoszap@laposte.net>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If an NFS client attempts to get a lock (using NLM) and the lock is
not available, the server will remember the request and when the lock
becomes available it will send a GRANT request to the client to
provide the lock.

If the client already held an adjacent lock, the GRANT callback will
report the union of the existing and new locks, which can confuse the
client.

This happens because __posix_lock_file (called by vfs_lock_file)
updates the passed-in file_lock structure when adjacent or
over-lapping locks are found.

To avoid this problem we take a copy of the two fields that can
be changed (fl_start and fl_end) before the call and restore them
afterwards.
An alternate would be to allocate a 'struct file_lock', initialise it,
use locks_copy_lock() to take a copy, then locks_release_private()
after the vfs_lock_file() call.  But that is a lot more work.
Reported-by: NOlaf Kirch <okir@suse.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

--
v1 had a couple of issues (large on-stack struct and didn't really work properly).
This version is much better tested.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>