If we're using cifsacl, then we don't want to override the uid/gid with
the current uid/gid, since that would prevent you from being able to
upcall for this info.
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

...and make those symbols static in cifsacl.c. Nothing outside
of that file refers to them.
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

The format specifiers are for signed values, but these are unsigned.
Given that '-' is a delimiter between fields, I don't think you'd get
what you'd expect if you got a value here that would overflow the sign
bit.

The version and authority fields are 8 bit values so use a "hh" length
modifier there. The subauths are 32 bit values, so there's no need to
use a "l" length modifier there.
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

According to several places on the Internet and the samba winbind code,
this is hard limited to 15 in windows, not 5. This does balloon out
the allocation of each by 40 bytes, but I don't see any alternative.

Also, rename it to SID_MAX_SUB_AUTHORITIES to match the alleged name
of this constant in the windows header files

Finally, rename SIDLEN to SID_STRING_MAX, fix the value to reflect
the change to SID_MAX_SUB_AUTHORITIES and document how it was
determined.
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

...and lift the restriction in id_to_sid upcall that the size must be
at least as big as a full cifs_sid.
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

..nothing outside of cifsacl.c calls it. Also fix the incorrect
comment on the function. It returns 0 when they match.
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

...instead of hardcoding in '5' and '6' all over the place.
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Add a label we can goto on error, and get rid of some excess indentation.
Also move to kernel-style comments.
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Most of these are unsigned ints, so we should be passing "uint" to
module_param. Also, get rid of the extra "(bool)" in the description
of enable_oplocks.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

We had planned to upgrade to ntlmv2 security a few releases ago,
and have been warning users in dmesg on mount about the impending
upgrade, but had to make a change (to use nltmssp with ntlmv2) due
to testing issues with some non-Windows, non-Samba servers.

The approach in this patch is simpler than earlier patches,
and changes the default authentication mechanism to ntlmv2
password hashes (encapsulated in ntlmssp) from ntlm (ntlm is
too weak for current use and ntlmv2 has been broadly
supported for many, many years).
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NJeff Layton <jlayton@redhat.com>

READ is zero so the "rw & READ" test is always false.  The intended test
was "((rw & RW_MASK) == READ)".
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull module fixes from Rusty Russell:
 "Module signing build fixes for blackfin and metag"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  modsign: add symbol prefix to certificate list
  linux/kernel.h: define SYMBOL_PREFIX

Pull UBI changes from Artem Bityutskiy:
 "Fixes for 2 brown-paperbag bugs introduced this merge window by the
  fastmap code:

   1.  The UBI background thread got stuck when a bit-flip happened
       because free LEBs was not removed from the "free" tree when we
       started using it.
   2.  I/O debugging checks did not work because we called a sleeping
       function in atomic context."

* tag 'upstream-3.7-rc9' of git://git.infradead.org/linux-ubi:
  UBI: dont call ubi_self_check_all_ff() in __wl_get_peb()
  UBI: remove PEB from free tree in get_peb_for_wl()

Pull workqueue fixes from Tejun Heo:
 "So, safe fixes my ass.

  Commit 8852aac2 ("workqueue: mod_delayed_work_on() shouldn't queue
  timer on 0 delay") had the side-effect of performing delayed_work
  sanity checks even when @delay is 0, which should be fine for any sane
  use cases.

  Unfortunately, megaraid was being overly ingenious.  It seemingly
  wanted to use cancel_delayed_work_sync() before cancel_work_sync() was
  introduced, but didn't want to waste the space for full delayed_work
  as it was only going to use 0 @delay.  So, it only allocated space for
  struct work_struct and then cast it to struct delayed_work and passed
  it into delayed_work functions - truly awesome engineering tradeoff to
  save some bytes.

  Xiaotian fixed it by making megraid allocate full delayed_work for
  now.  It should be converted to use work_struct and cancel_work_sync()
  but I think we better do that after 3.7.

  I added another commit to change BUG_ON()s in __queue_delayed_work()
  to WARN_ON_ONCE()s so that the kernel doesn't crash even if there are
  more such abuses."

* 'for-3.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s
  megaraid: fix BUG_ON() from incorrect use of delayed work

Pull sparc fixes from David Miller:
 "Two small fixes for Sparc, nobody uses sparc, so these are low risk :-)

   1) Piggyback is too picky about the symbol types that _start and _end
      have in the final kernel image, and it thus breaks with newer
      binutils.  Future proof by getting rid of the symbol type checks.

   2) exit_group() should kill register windows on sparc64 the same way
      we do for plain exit().  Thanks to Al Viro for spotting this."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: Fix piggyback with newer binutils.
  sparc64: exit_group should kill register windows just like plain exit.

The block device access simplification that avoided accessing the (racy)
block size information (commit bbec0270: "blkdev_max_block: make
private to fs/buffer.c") no longer checks the maximum block size in the
block mapping path.

That was _almost_ as simple as just removing the code entirely, because
the readers and writers all check the size of the device anyway, so
under normal circumstances it "just worked".

However, the block size may be such that the end of the device may
straddle one single buffer_head.  At which point we may still want to
access the end of the device, but the buffer we use to access it
partially extends past the end.

The 'bd_set_size()' function intentionally sets the block size to avoid
this, but mounting the device - or setting the block size by hand to
some other value - can modify that block size.

So instead, teach 'submit_bh()' about the special case of the buffer
head straddling the end of the device, and turning such an access into a
smaller IO access, avoiding the problem.

This, btw, also means that unlike before, we can now access the whole
device regardless of device block size setting.  So now, even if the
device size is only 512-byte aligned, we can read and write even the
last sector even when having a much bigger block size for accessing the
rest of the device.

So with this, we could now get rid of the 'bd_set_size()' block size
code entirely - resulting in faster IO for the common case - but that
would be a separate patch.
Reported-and-tested-by: NRomain Francoise <romain@orebokech.com>
Reporeted-and-tested-by: NMeelis Roos <mroos@linux.ee>
Reported-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

8852aac2 ("workqueue: mod_delayed_work_on() shouldn't queue timer on
0 delay") unexpectedly uncovered a very nasty abuse of delayed_work in
megaraid - it allocated work_struct, casted it to delayed_work and
then pass that into queue_delayed_work().

Previously, this was okay because 0 @delay short-circuited to
queue_work() before doing anything with delayed_work.  8852aac2
moved 0 @delay test into __queue_delayed_work() after sanity check on
delayed_work making megaraid trigger BUG_ON().

Although megaraid is already fixed by c1d390d8 ("megaraid: fix
BUG_ON() from incorrect use of delayed work"), this patch converts
BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s so that such
abusers, if there are more, trigger warning but don't crash the
machine.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Xiaotian Feng <xtfeng@gmail.com>

megaraid use INIT_WORK to declare a hotplug_work, but cast the
hotplug_work from work_struct to delayed_work and
schedule_delayed_work on it.  This is very dangerous, as other part of
delayed_work might be kernel memories allocated by others.

With commit 8852aac2 ("workqueue: mod_delayed_work_on() shouldn't queue
timer on 0 delay"), schedule_delayed_work() will check dwork->timer
before queue_work even when @delay is 0, this causes megaraid code to
hit the BUG_ON() in workqueue code.  Change megaraid code to use
delayed work.
Signed-off-by: NXiaotian Feng <dannyfeng@tencent.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org

As ubi_self_check_all_ff() might sleep we are not allowed
to call it from atomic context.
For now we call it only from ubi_wl_get_peb().
There are some code paths where it would also make sense,
but these paths are currently atomic and only enabled
when fastmap is used.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

If UBI is built without fastmap, get_peb_for_wl() has to
remove the PEB manially from the free tree.
Otherwise the requested PEB lives in two trees.
Reported-by: NZach Sadecki <zsadecki@itwatchdogs.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Newer versions of binutils mark '_end' as 'B' instead of 'A' for
whatever reason.

To be honest, the piggyback code doesn't actually care what kind
of symbol _start and _end are, it just wants to find them and
record the address.

So remove the type from the match strings.
Reported-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull EDAC fixes from Mauro Carvalho Chehab:
 "One EDAC core fix, and a few driver fixes (i7300, i9275x, i7core)."

* git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac:
  i7core_edac: fix panic when accessing sysfs files
  i7300_edac: Fix error flag testing
  edac: Fix the dimm filling for csrows-based layouts
  i82975x_edac: Fix dimm label initialization

Pull media fixes from Mauro Carvalho Chehab:
 "Some driver fixes for s5p/exynos (mostly race fixes)"

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] s5p-mfc: Handle multi-frame input buffer
  [media] s5p-mfc: Bug fix of timestamp/timecode copy mechanism
  [media] exynos-gsc: Add missing video device vfl_dir flag initialization
  [media] exynos-gsc: Fix settings for input and output image RGB type
  [media] exynos-gsc: Don't use mutex_lock_interruptible() in device release()
  [media] fimc-lite: Don't use mutex_lock_interruptible() in device release()
  [media] s5p-fimc: Don't use mutex_lock_interruptible() in device release()
  [media] s5p-fimc: Prevent race conditions during subdevs registration

In commit 9d73fc2d ("open*(2) compat fixes (s390, arm64)") I said:
>
> 	The usual rules for open()/openat()/open_by_handle_at() are
> 1) native 32bit - don't force O_LARGEFILE in flags
> 2) native 64bit - force O_LARGEFILE in flags
> 3) compat on 64bit host - as for native 32bit
> 4) native 32bit ABI for 64bit system (mips/n32, x86/x32) - as for native 64bit
>
> There are only two exceptions - s390 compat has open() forcing O_LARGEFILE and
> arm64 compat has open_by_handle_at() doing the same thing.  The same binaries
> on native host (s390/31 and arm resp.) will *not* force O_LARGEFILE, so IMO
> both are emulation bugs.

Three exceptions, actually - parisc open() is another case like that.
Native 32bit won't force O_LARGEFILE, the same binary on parisc64 will.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 800d4d30.

Between commits 8323f26c ("sched: Fix race in task_group()") and
800d4d30 ("sched, autogroup: Stop going ahead if autogroup is
disabled"), autogroup is a wreck.

With both applied, all you have to do to crash a box is disable
autogroup during boot up, then reboot..  boom, NULL pointer dereference
due to commit 800d4d30 not allowing autogroup to move things, and
commit 8323f26c making that the only way to switch runqueues:

  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [<ffffffff81063ac0>] effective_load.isra.43+0x50/0x90
  Pid: 7047, comm: systemd-user-se Not tainted 3.6.8-smp #7 MEDIONPC MS-7502/MS-7502
  RIP: effective_load.isra.43+0x50/0x90
  Process systemd-user-se (pid: 7047, threadinfo ffff880221dde000, task ffff88022618b3a0)
  Call Trace:
    select_task_rq_fair+0x255/0x780
    try_to_wake_up+0x156/0x2c0
    wake_up_state+0xb/0x10
    signal_wake_up+0x28/0x40
    complete_signal+0x1d6/0x250
    __send_signal+0x170/0x310
    send_signal+0x40/0x80
    do_send_sig_info+0x47/0x90
    group_send_sig_info+0x4a/0x70
    kill_pid_info+0x3a/0x60
    sys_kill+0x97/0x1a0
    ? vfs_read+0x120/0x160
    ? sys_read+0x45/0x90
    system_call_fastpath+0x16/0x1b
  Code: 49 0f af 41 50 31 d2 49 f7 f0 48 83 f8 01 48 0f 46 c6 48 2b 07 48 8b bf 40 01 00 00 48 85 ff 74 3a 45 31 c0 48 8b 8f 50 01 00 00 <48> 8b 11 4c 8b 89 80 00 00 00 49 89 d2 48 01 d0 45 8b 59 58 4c
  RIP  [<ffffffff81063ac0>] effective_load.isra.43+0x50/0x90
   RSP <ffff880221ddfbd8>
  CR2: 0000000000000000
Signed-off-by: NMike Galbraith <efault@gmx.de>
Acked-by: NIngo Molnar <mingo@kernel.org>
Cc: Yong Zhang <yong.zhang0@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Merge 'block-dev' branch.

I was going to just mark everything here for stable and leave it to the
3.8 merge window, but having decided on doing another -rc, I migth as
well merge it now.

This removes the bd_block_size_semaphore semaphore that was added in
this release to fix a race condition between block size changes and
block IO, and replaces it with atomicity guaratees in fs/buffer.c
instead, along with simplifying fs/block-dev.c.

This removes more lines than it adds, makes the code generally simpler,
and avoids the latency/rt issues that the block size semaphore
introduced for mount.

I'm not happy with the timing, but it wouldn't be much better doing this
during the merge window and then having some delayed back-port of it
into stable.

* block-dev:
  blkdev_max_block: make private to fs/buffer.c
  direct-io: don't read inode->i_blkbits multiple times
  blockdev: remove bd_block_size_semaphore again
  fs/buffer.c: make block-size be per-page and protected by the page lock

Add the arch symbol prefix (if applicable) to the asm definition of
modsign_certificate_list and modsign_certificate_list_end. This uses the
recently defined SYMBOL_PREFIX which is derived from
CONFIG_SYMBOL_PREFIX.

This fixes the build of module signing on the blackfin and metag
architectures.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Define SYMBOL_PREFIX to be the same as CONFIG_SYMBOL_PREFIX if set by
the architecture, or "" otherwise. This avoids the need for ugly #ifdefs
whenever symbols are referenced in asm blocks.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Pull networking fixes from David Miller:

 1) 8139cp leaks memory in error paths, from Francois Romieu.

 2) do_tcp_sendpages() cannot handle order > 0 pages, but they can
    certainly arrive there now, fix from Eric Dumazet.

 3) Race condition and sysfs fixes in bonding from Nikolay Aleksandrov.

 4) Remain-on-Channel fix in mac80211 from Felix Liao.

 5) CCK rate calculation fix in iwlwifi, from Emmanuel Grumbach.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  8139cp: fix coherent mapping leak in error path.
  tcp: fix crashes in do_tcp_sendpages()
  bonding: fix race condition in bonding_store_slaves_active
  bonding: make arp_ip_target parameter checks consistent with sysfs
  bonding: fix miimon and arp_interval delayed work race conditions
  mac80211: fix remain-on-channel (non-)cancelling
  iwlwifi: fix the basic CCK rates calculation

Pull md bugfix from NeilBrown:
 "Single bugfix for raid1/raid10.

  Fixes a recently introduced deadlock."

* tag 'md-3.7-fixes' of git://neil.brown.name/md:
  md/raid1{,0}: fix deadlock in bitmap_unplug.

The usual rules for open()/openat()/open_by_handle_at() are
 1) native 32bit - don't force O_LARGEFILE in flags
 2) native 64bit - force O_LARGEFILE in flags
 3) compat on 64bit host - as for native 32bit
 4) native 32bit ABI for 64bit system (mips/n32, x86/x32) - as for
    native 64bit

There are only two exceptions - s390 compat has open() forcing
O_LARGEFILE and arm64 compat has open_by_handle_at() doing the same
thing.  The same binaries on native host (s390/31 and arm resp.) will
*not* force O_LARGEFILE, so IMO both are emulation bugs.

Objections? The fix is obvious...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull  late workqueue fixes from Tejun Heo:
 "Unfortunately, I have two really late fixes.  One was for a
  long-standing bug and queued for 3.8 but I found out about a
  regression introduced during 3.7-rc1 two days ago, so I'm sending out
  the two fixes together.

  The first (long-standing) one is rescuer_thread() entering exit path
  w/ TASK_INTERRUPTIBLE.  It only triggers on workqueue destructions
  which isn't very frequent and the exit path can usually survive being
  called with TASK_INTERRUPT, so it was hidden pretty well.  Apparently,
  if you're reiserfs, this could lead to the exiting kthread sleeping
  indefinitely holding a mutex, which is never good.

  The fix is simple - restoring TASK_RUNNING before returning from the
  kthread function.

  The second one is introduced by the new mod_delayed_work().
  mod_delayed_work() was missing special case handling for 0 delay.
  Instead of queueing the work item immediately, it queued the timer
  which expires on the closest next tick.  Some users of the new
  function converted from "[__]cancel_delayed_work() +
  queue_delayed_work()" combination became unhappy with the extra delay.

  Block unplugging led to noticeably higher number of context switches
  and intel 6250 wireless failed to associate with WPA-Enterprise
  network.  The fix, again, is fairly simple.  The 0 delay special case
  logic from queue_delayed_work_on() should be moved to
  __queue_delayed_work() which is shared by both queue_delayed_work_on()
  and mod_delayed_work_on().

  The first one is difficult to trigger and the failure mode for the
  latter isn't completely catastrophic, so missing these two for 3.7
  wouldn't make it a disastrous release, but both bugs are nasty and the
  fixes are fairly safe"

* 'for-3.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: mod_delayed_work_on() shouldn't queue timer on 0 delay
  workqueue: exit rescuer_thread() as TASK_RUNNING

cp_open
[...]
        rc = cp_alloc_rings(cp);
        if (rc)
                return rc;

cp_alloc_rings
[...]
        mem = dma_alloc_coherent(&cp->pdev->dev, CP_RING_BYTES,
                                 &cp->ring_dma, GFP_KERNEL);

- cp_alloc_rings never frees the coherent mapping it allocates
- neither do cp_open when cp_alloc_rings fails
Signed-off-by: NFrancois Romieu <romieu@fr.zoreil.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Recent network changes allowed high order pages being used
for skb fragments.

This uncovered a bug in do_tcp_sendpages() which was assuming its caller
provided an array of order-0 page pointers.

We only have to deal with a single page in this function, and its order
is irrelevant.
Reported-by: NWilly Tarreau <w@1wt.eu>
Tested-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

8376fe22 ("workqueue: implement mod_delayed_work[_on]()")
implemented mod_delayed_work[_on]() using the improved
try_to_grab_pending().  The function is later used, among others, to
replace [__]candel_delayed_work() + queue_delayed_work() combinations.

Unfortunately, a delayed_work item w/ zero @delay is handled slightly
differently by mod_delayed_work_on() compared to
queue_delayed_work_on().  The latter skips timer altogether and
directly queues it using queue_work_on() while the former schedules
timer which will expire on the closest tick.  This means, when @delay
is zero, that [__]cancel_delayed_work() + queue_delayed_work_on()
makes the target item immediately executable while
mod_delayed_work_on() may induce delay of upto a full tick.

This somewhat subtle difference breaks some of the converted users.
e.g. block queue plugging uses delayed_work for deferred processing
and uses mod_delayed_work_on() when the queue needs to be immediately
unplugged.  The above problem manifested as noticeably higher number
of context switches under certain circumstances.

The difference in behavior was caused by missing special case handling
for 0 delay in mod_delayed_work_on() compared to
queue_delayed_work_on().  Joonsoo Kim posted a patch to add it -
("workqueue: optimize mod_delayed_work_on() when @delay == 0")[1].
The patch was queued for 3.8 but it was described as optimization and
I missed that it was a correctness issue.

As both queue_delayed_work_on() and mod_delayed_work_on() use
__queue_delayed_work() for queueing, it seems that the better approach
is to move the 0 delay special handling to the function instead of
duplicating it in mod_delayed_work_on().

Fix the problem by moving 0 delay special case handling from
queue_delayed_work_on() to __queue_delayed_work().  This replaces
Joonsoo's patch.

[1] http://thread.gmane.org/gmane.linux.kernel/1379011/focus=1379012Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-and-tested-by: NAnders Kaseorg <andersk@MIT.EDU>
Reported-and-tested-by: NZlatko Calusic <zlatko.calusic@iskon.hr>
LKML-Reference: <alpine.DEB.2.00.1211280953350.26602@dr-wily.mit.edu>
LKML-Reference: <50A78AA9.5040904@iskon.hr>
Cc: Joonsoo Kim <js1304@gmail.com>

A rescue thread exiting TASK_INTERRUPTIBLE can lead to a task scheduling
off, never to be seen again.  In the case where this occurred, an exiting
thread hit reiserfs homebrew conditional resched while holding a mutex,
bringing the box to its knees.

PID: 18105  TASK: ffff8807fd412180  CPU: 5   COMMAND: "kdmflush"
 #0 [ffff8808157e7670] schedule at ffffffff8143f489
 #1 [ffff8808157e77b8] reiserfs_get_block at ffffffffa038ab2d [reiserfs]
 #2 [ffff8808157e79a8] __block_write_begin at ffffffff8117fb14
 #3 [ffff8808157e7a98] reiserfs_write_begin at ffffffffa0388695 [reiserfs]
 #4 [ffff8808157e7ad8] generic_perform_write at ffffffff810ee9e2
 #5 [ffff8808157e7b58] generic_file_buffered_write at ffffffff810eeb41
 #6 [ffff8808157e7ba8] __generic_file_aio_write at ffffffff810f1a3a
 #7 [ffff8808157e7c58] generic_file_aio_write at ffffffff810f1c88
 #8 [ffff8808157e7cc8] do_sync_write at ffffffff8114f850
 #9 [ffff8808157e7dd8] do_acct_process at ffffffff810a268f
    [exception RIP: kernel_thread_helper]
    RIP: ffffffff8144a5c0  RSP: ffff8808157e7f58  RFLAGS: 00000202
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: 0000000000000000
    RDX: 0000000000000000  RSI: ffffffff8107af60  RDI: ffff8803ee491d18
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000000  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
Signed-off-by: NMike Galbraith <mgalbraith@suse.de>
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

Pull vfs fixes from Al Viro:
 "A bunch of fixes; the last one is this cycle regression, the rest are
  -stable fodder."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix off-by-one in argument passed by iterate_fd() to callbacks
  lookup_one_len: don't accept . and ..
  cifs: get rid of blind d_drop() in readdir
  nfs_lookup_revalidate(): fix a leak
  don't do blind d_drop() in nfs_prime_dcache()