If nothing else this simplifies the nfs4_state_shutdown_net logic a tad.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Once we've unhashed the delegation, it's only hanging around for the
benefit of an oustanding recall, which only needs the encoded
filehandle, stateid, and dl_retries counter.  No point keeping the file
around any longer, or keeping it hashed.

This also fixes a race: calls to idr_remove should really be serialized
by the caller, but the nfs4_put_delegation call from the callback code
isn't taking the state lock.

(Better might be to cancel the callback before destroying the
delegation, and remove any need for reference counting--but I don't see
an easy way to cancel an rpc call.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

If kmalloc() fails in cache_open(), module cd->owner left locked.
The patch adds module_put(cd->owner) on this path.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

when create /proc/fs/nfs/exports error, we should remove /proc/fs/nfs,
if don't do it, it maybe cause Memory leak.
Signed-off-by: fanchaoting <fanchaoting@cn.fujitsu.com>
Reviewed-by: chendt.fnst <chendt.fnst@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

we should return error status directly when nfs4_preprocess_stateid_op
return error.
Signed-off-by: fanchaoting <fanchaoting@cn.fujitsu.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

We only ever traverse the hash chains in the forward direction, so a
double pointer list head isn't really necessary.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This changes session destruction to be similar to client destruction in
that attempts to destroy a session while in use (which should be rare
corner cases) result in DELAY.  This simplifies things somewhat and
helps meet a coming 4.2 requirement.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

When a setclientid_confirm or create_session confirms a client after a
client reboot, it also destroys any previous state held by that client.

The shutdown of that previous state must be careful not to free the
client out from under threads processing other requests that refer to
the client.

This is a particular problem in the NFSv4.1 case when we hold a
reference to a session (hence a client) throughout compound processing.

The server attempts to handle this by unhashing the client at the time
it's destroyed, then delaying the final free to the end.  But this still
leaves some races in the current code.

I believe it's simpler just to fail the attempt to destroy the client by
returning NFS4ERR_DELAY.  This is a case that should never happen
anyway.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The locking here is very fiddly, and there's no reason for us to be
setting cstate->session, since this is the only op in the compound.
Let's just take the state lock and drop the reference counting.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

destroy_session uses the session and client without continuously holding
any reference or locks.

Put the whole thing under the state lock for now.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

I'm not sure what the check for clientid expiry was meant to do here.

The check for a matching session is redundant given the previous check
for state: a client without state is, in particular, a client without
sessions.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

E.g. printk's that just report the return value from an op are
uninteresting as we already do that in the main proc_compound loop.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This should never happen.

(Note: the comparable case in setclientid_confirm *can* happen, since
updating a client record can result in both confirmed and unconfirmed
records with the same clientid.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFS4_OO_PURGE_CLOSE is not handled properly. To avoid memory leak, nfs4
stateid which is pointed by oo_last_closed_stid is freed in nfsd4_close(),
but NFS4_OO_PURGE_CLOSE isn't cleared meanwhile. So the stateid released in
THIS close procedure may be freed immediately in the coming encoding function.
Sorry that Signed-off-by was forgotten in last version.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

lk_rflags is never used anywhere, and rflags is not defined in struct
nfsd4_lock.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Once we drop the lock here there's nothing keeping the client around:
the only lock still held is the xpt_lock on this socket, but this socket
no longer has any connection with the client so there's no way for other
code to know we're still using the client.

The solution is simple: all nfsd4_probe_callback does is set a few
variables and queue some work, so there's no reason we can't just keep
it under the lock.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Dropping the session's reference count after the client's means we leave
a window where the session's se_client pointer is NULL.  An xpt_user
callback that encounters such a session may then crash:

[  303.956011] BUG: unable to handle kernel NULL pointer dereference at 0000000000000318
[  303.959061] IP: [<ffffffff81481a8e>] _raw_spin_lock+0x1e/0x40
[  303.959061] PGD 37811067 PUD 3d498067 PMD 0
[  303.959061] Oops: 0002 [#8] PREEMPT SMP
[  303.959061] Modules linked in: md5 nfsd auth_rpcgss nfs_acl snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc microcode psmouse snd_timer serio_raw pcspkr evdev snd soundcore i2c_piix4 i2c_core intel_agp intel_gtt processor button nfs lockd sunrpc fscache ata_generic pata_acpi ata_piix uhci_hcd libata btrfs usbcore usb_common crc32c scsi_mod libcrc32c zlib_deflate floppy virtio_balloon virtio_net virtio_pci virtio_blk virtio_ring virtio
[  303.959061] CPU 0
[  303.959061] Pid: 264, comm: nfsd Tainted: G      D      3.8.0-ARCH+ #156 Bochs Bochs
[  303.959061] RIP: 0010:[<ffffffff81481a8e>]  [<ffffffff81481a8e>] _raw_spin_lock+0x1e/0x40
[  303.959061] RSP: 0018:ffff880037877dd8  EFLAGS: 00010202
[  303.959061] RAX: 0000000000000100 RBX: ffff880037a2b698 RCX: ffff88003d879278
[  303.959061] RDX: ffff88003d879278 RSI: dead000000100100 RDI: 0000000000000318
[  303.959061] RBP: ffff880037877dd8 R08: ffff88003c5a0f00 R09: 0000000000000002
[  303.959061] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
[  303.959061] R13: 0000000000000318 R14: ffff880037a2b680 R15: ffff88003c1cbe00
[  303.959061] FS:  0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
[  303.959061] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  303.959061] CR2: 0000000000000318 CR3: 000000003d49c000 CR4: 00000000000006f0
[  303.959061] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  303.959061] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  303.959061] Process nfsd (pid: 264, threadinfo ffff880037876000, task ffff88003c1fd0a0)
[  303.959061] Stack:
[  303.959061]  ffff880037877e08 ffffffffa03772ec ffff88003d879000 ffff88003d879278
[  303.959061]  ffff88003d879080 0000000000000000 ffff880037877e38 ffffffffa0222a1f
[  303.959061]  0000000000107ac0 ffff88003c22e000 ffff88003d879000 ffff88003c1cbe00
[  303.959061] Call Trace:
[  303.959061]  [<ffffffffa03772ec>] nfsd4_conn_lost+0x3c/0xa0 [nfsd]
[  303.959061]  [<ffffffffa0222a1f>] svc_delete_xprt+0x10f/0x180 [sunrpc]
[  303.959061]  [<ffffffffa0223d96>] svc_recv+0xe6/0x580 [sunrpc]
[  303.959061]  [<ffffffffa03587c5>] nfsd+0xb5/0x140 [nfsd]
[  303.959061]  [<ffffffffa0358710>] ? nfsd_destroy+0x90/0x90 [nfsd]
[  303.959061]  [<ffffffff8107ae00>] kthread+0xc0/0xd0
[  303.959061]  [<ffffffff81010000>] ? perf_trace_xen_mmu_set_pte_at+0x50/0x100
[  303.959061]  [<ffffffff8107ad40>] ? kthread_freezable_should_stop+0x70/0x70
[  303.959061]  [<ffffffff814898ec>] ret_from_fork+0x7c/0xb0
[  303.959061]  [<ffffffff8107ad40>] ? kthread_freezable_should_stop+0x70/0x70
[  303.959061] Code: ff ff 5d c3 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 65 48 8b 04 25 f0 c6 00 00 48 89 e5 83 80 44 e0 ff ff 01 b8 00 01 00 00 <3e> 66 0f c1 07 0f b6 d4 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f
[  303.959061] RIP  [<ffffffff81481a8e>] _raw_spin_lock+0x1e/0x40
[  303.959061]  RSP <ffff880037877dd8>
[  303.959061] CR2: 0000000000000318
[  304.001218] ---[ end trace 2d809cd4a7931f5a ]---
[  304.001903] note: nfsd[264] exited with preempt_count 2
Reported-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

If a client sets an owner (or group_owner or acl) attribute on open for
create, and the mapping of that owner to an id fails, then we return
BAD_OWNER.  But BAD_OWNER is a seqid-mutating error, so we can't
shortcut the open processing that case: we have to at least look up the
owner so we can find the seqid to bump.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This BUG_ON just crashes the thread a little earlier than it would
otherwise--it doesn't seem useful.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

We've now increased the size of the duplicate reply cache by quite a
bit, but the number of hash buckets has not changed. So, we've gone from
an average hash chain length of 16 in the old code to 4096 when the
cache is its largest. Change the code to scale out the number of buckets
with the max size of the cache.

At the same time, we also need to fix the hash function since the
existing one isn't really suitable when there are more than 256 buckets.
Move instead to use the stock hash_32 function for this. Testing on a
machine that had 2048 buckets showed that this gave a smaller
longest:average ratio than the existing hash function:

The formula here is longest hash bucket searched divided by average
number of entries per bucket at the time that we saw that longest
bucket:

    old hash: 68/(39258/2048) == 3.547404
    hash_32:  45/(33773/2048) == 2.728807
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The typical case with the DRC is a cache miss, so if we keep track of
the max number of entries that we've ever walked over in a search, then
we should have a reasonable estimate of the longest hash chain that
we've ever seen.

With that, we'll also keep track of the total size of the cache when we
see the longest chain. In the case of a tie, we prefer to track the
smallest total cache size in order to properly gauge the worst-case
ratio of max vs. avg chain length.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

For presenting statistics relating to duplicate reply cache.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Break out the function that compares the rqstp and checksum against a
reply cache entry. While we're at it, track the efficacy of the checksum
over the NFS data by tracking the cases where we would have incorrectly
matched a DRC entry if we had not tracked it or the length.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The most common case is to do a search of the cache, followed by an
insert. In the case where we have to allocate an entry off the slab,
then we end up having to redo the search, which is wasteful.

Better optimize the code for the common case by eliminating the initial
search of the cache and always preallocating an entry. In the case of a
cache hit, we'll end up just freeing that entry but that's preferable to
an extra search.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Since we only enforce an upper bound, not a lower bound, a "negative"
length can get through here.

The symptom seen was a warning when we attempt to a kmalloc with an
excessive size.
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

vfs_writev() updates the offset argument - but the code then passes the
offset to vfs_fsync_range(). Since offset now points to the offset after
what was just written, this is probably not what was intended

Introduced by face1502 "nfsd: use
vfs_fsync_range(), not O_SYNC, for stable writes".
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: stable@vger.kernel.org
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

If we end up doing "goto out_nomem" in this function, we'll call
nfsd_reply_cache_shutdown. That will attempt to walk the LRU list and
free entries, but that list may not be initialized yet if the server is
starting up for the first time. It's also possible for the shrinker to
kick in before we've initialized the LRU list.

Rearrange the initialization so that the LRU list_head and cache size
are initialized before doing any of the allocations that might fail.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

It's not safe to call hlist_del() on a newly initialized hlist_node.
That leads to a NULL pointer dereference. Only do that if the entry
is hashed.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Commit 1d9d8639 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") introduces a link failure since
perf_restore_debug_store() is only defined for CONFIG_CPU_SUP_INTEL:

	arch/x86/power/built-in.o: In function `restore_processor_state':
	(.text+0x45c): undefined reference to `perf_restore_debug_store'

Fix it by defining the dummy function appropriately.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 1d9d8639 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") fixed a crash when doing PEBS performance profiling
after resuming, but in using init_debug_store_on_cpu() to restore the
DS_AREA mtrr it also resulted in a new WARN_ON() triggering.

init_debug_store_on_cpu() uses "wrmsr_on_cpu()", which in turn uses CPU
cross-calls to do the MSR update.  Which is not really valid at the
early resume stage, and the warning is quite reasonable.  Now, it all
happens to _work_, for the simple reason that smp_call_function_single()
ends up just doing the call directly on the CPU when the CPU number
matches, but we really should just do the wrmsr() directly instead.

This duplicates the wrmsr() logic, but hopefully we can just remove the
wrmsr_on_cpu() version eventually.
Reported-and-tested-by: Parag Warudkar <parag.lkml@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull btrfs fixes from Chris Mason:
 "Eric's rcu barrier patch fixes a long standing problem with our
  unmount code hanging on to devices in workqueue helpers.  Liu Bo
  nailed down a difficult assertion for in-memory extent mappings."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix warning of free_extent_map
  Btrfs: fix warning when creating snapshots
  Btrfs: return as soon as possible when edquot happens
  Btrfs: return EIO if we have extent tree corruption
  btrfs: use rcu_barrier() to wait for bdev puts at unmount
  Btrfs: remove btrfs_try_spin_lock
  Btrfs: get better concurrency for snapshot-aware defrag work

Users report that an extent map's list is still linked when it's actually
going to be freed from cache.

The story is that

a) when we're going to drop an extent map and may split this large one into
smaller ems, and if this large one is flagged as EXTENT_FLAG_LOGGING which means
that it's on the list to be logged, then the smaller ems split from it will also
be flagged as EXTENT_FLAG_LOGGING, and this is _not_ expected.

b) we'll keep ems from unlinking the list and freeing when they are flagged with
EXTENT_FLAG_LOGGING, because the log code holds one reference.

The end result is the warning, but the truth is that we set the flag
EXTENT_FLAG_LOGGING only during fsync.

So clear flag EXTENT_FLAG_LOGGING for extent maps split from a large one.
Reported-by: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Pull kbuild fix from Michal Marek:
 "One fix for for make headers_install/headers_check to not require make
  3.81.  The requirement has been accidentally introduced in 3.7."

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: fix make headers_check with make 3.80

Pull OpenRISC bug fixes from Jonas Bonn:

 - The GPIO descriptor work has exposed how broken the non-GPIOLIB bits
   for OpenRISC were.  We now require GPIOLIB as this is the preferred
   way forward.

 - The system.h split introduced a bug in llist.h for arches using
   asm-generic/cmpxchg.h directly, which is currently only OpenRISC.
   The patch here moves two defines from asm-generic/atomic.h to
   asm-generic/cmpxchg.h to make things work as they should.

 - The VIRT_TO_BUS selector was added for OpenRISC, but OpenRISC does
   not have the virt_to_bus methods, so there's a patch to remove it
   again.

* tag 'for-3.9-rc3' of git://openrisc.net/jonas/linux:
  openrisc: remove HAVE_VIRT_TO_BUS
  asm-generic: move cmpxchg*_local defs to cmpxchg.h
  openrisc: require gpiolib

Pull char/misc fixes from Greg Kroah-Hartman:
 "Here are some tiny fixes for the w1 drivers and the final removal
  patch for getting rid of CONFIG_EXPERIMENTAL (all users of it are now
  gone from your tree, this just drops the Kconfig item itself.)

  All have been in the linux-next tree for a while"

* tag 'char-misc-3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  final removal of CONFIG_EXPERIMENTAL
  w1: fix oops when w1_search is called from netlink connector
  w1-gpio: fix unused variable warning
  w1-gpio: remove erroneous __exit and __exit_p()
  ARM: w1-gpio: fix erroneous gpio requests