They aren't very good to inline, since they already call external
functions (the spinlock code), and we're going to create rather more
complicated versions of them that can do the reference count updates
locklessly.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This moves __d_rcu_to_refcount() from <linux/dcache.h> into fs/namei.c
and re-implements it using the lockref infrastructure instead.  It also
adds a lot of comments about what is actually going on, because turning
a dentry that was looked up using RCU into a long-lived reference
counted entry is one of the more subtle parts of the rcu walk.

We also used to be _particularly_ subtle in unlazy_walk() where we
re-validate both the dentry and its parent using the same sequence
count.  We used to do it by nesting the locks and then verifying the
sequence count just once.

That was silly, because nested locking is expensive, but the sequence
count check is not.  So this just re-validates the dentry and the parent
separately, avoiding the nested locking, and making the lockref lookup
possible.
Acked-by: Waiman Long <waiman.long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A valid parent pointer is always going to have a non-zero reference
count, but if we look up the parent optimistically without locking, we
have to protect against the (very unlikely) race against renaming
changing the parent from under us.

We do that by using lockref_get_not_zero(), and then re-checking the
parent pointer after getting a valid reference.

[ This is a re-implementation of a chunk from the original patch by
  Waiman Long: "dcache: Enable lockless update of dentry's refcount".
  I've completely rewritten the patch-series and split it up, but I'm
  attributing this part to Waiman as it's close enough to his earlier
  patch  - Linus ]
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This behaves like "lockref_get_not_zero()", but instead of doing nothing
if the count was zero, it returns with the lock held.

This allows callers to revalidate the lockref-protected data structure
if required even if the count was zero to begin with, and possibly
increment the count if it passes muster.

In particular, the dentry code wants this when it wants to turn an
RCU-protected dentry into a stable refcounted one: if the dentry count
it zero, but the sequence number still validates the dentry, we can take
a reference to it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This just replaces the dentry count/lock combination with the lockref
structure that contains both a count and a spinlock, and does the
mechanical conversion to use the lockref infrastructure.

There are no semantic changes here, it's purely syntactic.  The
reference lockref implementation uses the spinlock exactly the same way
that the old dcache code did, and the bulk of this patch is just
expanding the internal "d_count" use in the dcache code to use
"d_lockref.count" instead.

This is purely preparation for the real change to make the reference
count updates be lockless during the 3.12 merge window.

[ As with the previous commit, this is a rewritten version of a concept
  originally from Waiman, so credit goes to him, blame for any errors
  goes to me.

  Waiman's patch had some semantic differences for taking advantage of
  the lockless update in dget_parent(), while this patch is
  intentionally a pure search-and-replace change with no semantic
  changes.     - Linus ]
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This introduces a new "lockref" structure that supports the concept of
lockless updates of reference counts that still honor an attached
spinlock.

NOTE! This reference implementation is not the optimized lockless
version, rather it is the fallback implementation using standard
spinlocks.  The actual optimized versions will be merged into 3.12, but
I wanted to get the infrastructure in place and document the new
interfaces.

[ Also note that this particular commit is drastically cut-down minimal
  version of the original patch by Waiman.  In order to properly credit
  the original author I'm marking Waiman as the author here, but in the
  end this patch bears little resemblance to the patch by Waiman.  So
  blame any errors on me editing things down to the point where I can
  introduce the infrastructure before the merge window for 3.12 actually
  opens.     - Linus ]
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit bb2314b4.

It wasn't necessarily wrong per se, but we're still busily discussing
the exact details of this all, so I'm going to revert it for now.

It's true that you can already do flink() through /proc and that flink()
isn't new.  But as Brad Spengler points out, some secure environments do
not mount proc, and flink adds a new interface that can avoid path
lookup of the source for those kinds of environments.

We may re-do this (and even mark it for stable backporting back in 3.11
and possibly earlier) once the whole discussion about the interface is done.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull regmap fixes from Mark Brown:
 "Two changes here:

   - Fix a bug in the rbtree code which could cause it to create two
     different cache entries for the same register by adding a single
     register at a time to the cache.  This isn't awesome for
     performance but it's non-invasive which we need for this late in
     the release cycle and the I/O costs we're trying to avoid are high.

   - Add another header used in the !CONFIG_REGMAP stubs where we had
     been relying on implicit inclusion"

* tag 'regmap-v3.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: rbtree: Fix overlapping rbnodes.
  regmap: Add another missing header for !CONFIG_REGMAP stubs

Pull powerpc fixes from Ben Herrenschmidt:
 "Here are 3 bug fixes that should probably go into 3.11 since I'm also
  tagging them for stable.

  Once fixes our old /proc/powerpc/lparcfg file which provides partition
  informations when running under our hypervisor and also acts as a
  user-triggerable Oops when hot :-(

  The other two respectively are a one liner to fix a HVSI protocol
  handshake problem causing the console to fail to show up on a bunch of
  machines until we reach userspace, which I deem annoying enough to
  warrant going to stable, and a nasty gcc miscompile causing us to pass
  virtual instead of physical addresses to the firmware under some
  circumstances"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/hvsi: Increase handshake timeout from 200ms to 400ms.
  powerpc: Work around gcc miscompilation of __pa() on 64-bit
  powerpc: Don't Oops when accessing /proc/powerpc/lparcfg without hypervisor

Dave reported corrupted swap entries

 | [ 4588.541886] swap_free: Unused swap offset entry 00002d15
 | [ 4588.541952] BUG: Bad page map in process trinity-kid12  pte:005a2a80 pmd:22c01f067

and Hugh pointed that in move_ptes _PAGE_SOFT_DIRTY bit set regardless
the type of entry pte consists of.  The trick here is that when we carry
soft dirty status in swap entries we are to use _PAGE_SWP_SOFT_DIRTY
instead, because this is the only place in pte which can be used for own
needs without intersecting with bits owned by swap entry type/offset.
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Analyzed-by: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This solves a problem observed in kexec'ed kernel where 200ms timeout is
too short and bootconsole fails to initialize. Console did eventually
become workable but much later into the boot process.

Observed timeout was around 260ms, but I decided to make it a little bigger
for more reliability.

This has been tested on Power7 machine with Petitboot as a primary
bootloader and PowerNV firmware.

CC: <stable@vger.kernel.org>
Signed-off-by: Eugene Surovegin <surovegin@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

On 64-bit, __pa(&static_var) gets miscompiled by recent versions of
gcc as something like:

        addis 3,2,.LANCHOR1+4611686018427387904@toc@ha
        addi 3,3,.LANCHOR1+4611686018427387904@toc@l

This ends up effectively ignoring the offset, since its bottom 32 bits
are zero, and means that the result of __pa() still has 0xC in the top
nibble.  This happens with gcc 4.8.1, at least.

To work around this, for 64-bit we make __pa() use an AND operator,
and for symmetry, we make __va() use an OR operator.  Using an AND
operator rather than a subtraction ends up with slightly shorter code
since it can be done with a single clrldi instruction, whereas it
takes three instructions to form the constant (-PAGE_OFFSET) and add
it on.  (Note that MEMORY_START is always 0 on 64-bit.)

CC: <stable@vger.kernel.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

/proc/powerpc/lparcfg is an ancient facility (though still actively used)
which allows access to some informations relative to the partition when
running underneath a PAPR compliant hypervisor.

It makes no sense on non-pseries machines. However, currently, not only
can it be created on these if the kernel has pseries support, but accessing
it on such a machine will crash due to trying to do hypervisor calls.

In fact, it should also not do HV calls on older pseries that didn't have
an hypervisor either.

Finally, it has the plumbing to be a module but is a "bool" Kconfig option.

This fixes the whole lot by turning it into a machine_device_initcall
that is only created on pseries, and adding the necessary hypervisor
check before calling the H_GET_EM_PARMS hypercall

CC: <stable@vger.kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Pull USB bugfix from Greg KH:
 "Here is a single bugfix that resolves the "can not build the OHCI
  driver with CONFIG_PM disabled" problem that lots of people have been
  reporting with 3.11-rc7.  Sorry about that one, it missed my build
  tests, and it seems, a number of others as well.

  Thank goodness for Guenter :)"

* tag 'usb-3.11-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: OHCI: fix build error related to ohci_suspend/resume

Pull jfs fix from Dave Kleikamp:
 "One JFS patch to fix an incompatibility with NFSv4 resulting in the
  nfs client reporting a readdir loop"

* tag 'jfs-3.11-rc8' of git://github.com/kleikamp/linux-shaggy:
  jfs: fix readdir cookie incompatibility with NFSv4

Commit 9a11899c (USB: OHCI: add missing PCI PM callbacks to
ohci-pci.c) added missing ohci_suspend and ohci_resume callback
pointers, but forgot that these callbacks are declared and defined
only when CONFIG_PM is enabled.

This patch adds a preprocessor conditional to avoid build errors when
PM is disabled.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Meelis Roos <mroos@linux.ee>,
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull staging fixes from Greg KH:
 "Here are two tiny staging tree fixes (well, one is for an iio driver,
  but those updates come through the staging tree due to dependancies)

  One fixes a problem with an IIO driver, and the other fixes a bug in
  the comedi driver core"

* tag 'staging-3.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: comedi: bug-fix NULL pointer dereference on failed attach
  iio: adjd_s311: Fix non-scan mode data read

Pull USB fixes from Greg KH:
 "Here are two USB fixes for 3.11-rc7

  One fixes a reported regression in the OHCI driver, and the other
  fixes a reported build breakage in the USB phy drivers"

* tag 'usb-3.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: phy: fix build breakage
  USB: OHCI: add missing PCI PM callbacks to ohci-pci.c

Pull ARM fixes from Russell King:
 "This round of fixes is smaller than previous: a couple more updates
  for the security fixes, and a one-liner kexec fix"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7816/1: CONFIG_KUSER_HELPERS: fix help text
  ARM: 7815/1: kexec: offline non panic CPUs on Kdump panic
  ARM: 7819/1: fiq: Cast the first argument of flush_icache_range()

Pull vfs fixes from Al Viro:
 "Assorted fixes from the last week or so"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  VFS: collect_mounts() should return an ERR_PTR
  bfs: iget_locked() doesn't return an ERR_PTR
  efs: iget_locked() doesn't return an ERR_PTR()
  proc: kill the extra proc_readfd_common()->dir_emit_dots()
  cope with potentially long ->d_dname() output for shmem/hugetlb

Pull ACPI fix from Rafael Wysocki:
 "I really hoped that it wouldn't be necessary to change anything in
  ACPI at this point, but it turns out that we need to revert one more
  ACPI video commit causing trouble.

  This reverts a change in the ACPI video driver that caused the ACPI
  backlight initialization to be carried out even if acpi_backlight=vendor
  is passed in the kernel command line which turns out to break things
  at least on one system"

* tag 'acpi-3.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "ACPI / video: Always call acpi_video_init_brightness() on init"

Pull SCSI fixes from James Bottomley:
 "This is a set of small bug fixes for lpfc and zfcp and a fix for a
  fairly nasty bug in sg where a process which cancels I/O completes in
  a kernel thread which would then try to write back to the now gone
  userspace and end up writing to a random kernel address instead"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  [SCSI] zfcp: remove access control tables interface (keep sysfs files)
  [SCSI] zfcp: fix schedule-inside-lock in scsi_device list loops
  [SCSI] zfcp: fix lock imbalance by reworking request queue locking
  [SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal
  [SCSI] lpfc: Don't force CONFIG_GENERIC_CSUM on

For a search buffer, 2 byte aligned, strchr() was returning pointer
outside of buffer (buf - 1)

------------->8----------------
    // Input buffer (default 4 byte aigned)
    char *buffer = "1AA_";

    // actual search start (to mimick 2 byte alignment)
    char *current_line = &(buffer[2]);

    // Character to search for
    char c = 'A';

    char *c_pos = strchr(current_line, c);

    printf("%s\n", c_pos) --> 'AA_' as oppose to 'A_'
------------->8----------------
Reported-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Debugged-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Cc: <stable@vger.kernel.org> # [3.9 and 3.10]
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: Joern Rennecke  <joern.rennecke@embecosm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This should actually be returning an ERR_PTR on error instead of NULL.
That was how it was designed and all the callers expect it.

[AV: actually, that's what "VFS: Make clone_mnt()/copy_tree()/collect_mounts()
return errors" missed - originally collect_mounts() was expected to return
NULL on failure]

Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

iget_locked() returns a NULL on error, it doesn't return an ERR_PTR.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The iget_locked() function returns NULL on error and never an ERR_PTR.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

proc_readfd_common() does dir_emit_dots() twice in a row,
we need to do this only once.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

dynamic_dname() is both too much and too little for those - the
output may be well in excess of 64 bytes dynamic_dname() assumes
to be enough (thanks to ashmem feeding really long names to
shmem_file_setup()) and vsnprintf() is an overkill for those
guys.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull libata fixes from Tejun Heo:
 "This contains three commits all of which are updates for specific
  devices which aren't too widespread.  Pretty limited scope and nothing
  too interesting or dangerous"

* 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  sata_fsl: save irqs while coalescing
  libata: apply behavioral quirks to sil3826 PMP
  sata, highbank: fix ordering of SGPIO signals

Pull cgroup fix from Tejun Heo:
 "A late fix for cgroup.

  This fixes a behavior regression visible to userland which was created
  by a commit merged during -rc1.  While the behavior change isn't too
  likely to be noticeable, the fix is relatively low risk and we'll need
  to backport it through -stable anyway if the bug gets released"

* 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: fix a regression in validating config change

Pull drm fixes from Dave Airlie:
 "Ben was on holidays for a week so a few nouveau regression fixes
  backed up, but they all seem necessary.

  Otherwise one i915 and one gma500 fix"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  gma500: Fix SDVO turning off randomly
  drm/nv04/disp: fix framebuffer pin refcounting
  drm/nouveau/mc: fix race condition between constructor and request_irq()
  drm/nouveau: fix reclocking on nv40
  drm/nouveau/ltcg: fix allocating memory as free
  drm/nouveau/ltcg: fix ltcg memory initialization after suspend
  drm/nouveau/fb: fix null derefs in nv49 and nv4e init
  drm/i915: Invalidate TLBs for the rings after a reset

Commit 94ae9843 (usb: phy: rename all phy drivers to phy-$name-usb.c)
renamed drivers/usb/phy/otg_fsm.h to drivers/usb/phy/phy-fsm-usb.h
but changed drivers/usb/phy/phy-fsm-usb.c to include not existing
"phy-otg-fsm.h" instead of new "phy-fsm-usb.h". This breaks building:
  ...
  drivers/usb/phy/phy-fsm-usb.c:32:25: fatal error: phy-otg-fsm.h: No such file or directory
  compilation terminated.
  make[3]: *** [drivers/usb/phy/phy-fsm-usb.o] Error 1

This commit also missed to modify drivers/usb/phy/phy-fsl-usb.h
to include new "phy-fsm-usb.h" instead of "otg_fsm.h" resulting
in another build breakage:
  ...
  In file included from drivers/usb/phy/phy-fsl-usb.c:46:0:
  drivers/usb/phy/phy-fsl-usb.h:18:21: fatal error: otg_fsm.h: No such file or directory
  compilation terminated.
  make[3]: *** [drivers/usb/phy/phy-fsl-usb.o] Error 1

Fix both issues.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: stable <stable@vger.kernel.org> # 3.10+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit c1117afb (USB: OHCI: make ohci-pci a separate driver)
neglected to preserve the entries for the pci_suspend and pci_resume
driver callbacks.  As a result, OHCI controllers don't work properly
during suspend and after hibernation.

This patch adds the missing callbacks to the driver.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Steve Cotton <steve@s.cotton.clara.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit dcd7b8bd ("staging: comedi: put
module _after_ detach" by myself) reversed a couple of calls in
`comedi_device_attach()` when recovering from an error returned by the
low-level driver's 'attach' handler.  Unfortunately, that introduced a
NULL pointer dereference bug as `dev->driver` is NULL after the call to
`comedi_device_detach()`.   We still have a pointer to the low-level
comedi driver structure in the `driv` variable, so use that instead.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge networking fixes from David Miller:

 1) Revert Johannes Berg's genetlink locking fix, because it causes
    regressions.

    Johannes and Pravin Shelar are working on fixing things properly.

 2) Do not drop ipv6 ICMP messages without a redirected header option,
    they are legal.  From Duan Jiong.

 3) Missing error return propagation in probing of via-ircc driver.
    From Alexey Khoroshilov.

 4) Do not clear out broadcast/multicast/unicast/WOL bits in r8169 when
    initializing, from Peter Wu.

 5) realtek phy driver programs wrong interrupt status bit, from
    Giuseppe CAVALLARO.

 6) Fix statistics regression in AF_PACKET code, from Willem de Bruijn.

 7) Bridge code uses wrong bitmap length, from Toshiaki Makita.

 8) SFC driver uses wrong indexes to look up MAC filters, from Ben
    Hutchings.

 9) Don't pass stack buffers into usb control operations in hso driver,
    from Daniel Gimpelevich.

10) Multiple ipv6 fragmentation headers in one packet is illegal and
    such packets should be dropped, from Hannes Frederic Sowa.

11) When TCP sockets are "repaired" as part of checkpoint/restart, the
    timestamp field of SKBs need to be refreshed otherwise RTOs can be
    wildly off.  From Andrey Vagin.

12) Fix memcpy args (uses 'address of pointer' instead of 'pointer') in
    hostp driver.  From Dan Carpenter.

13) nl80211hdr_put() doesn't return an ERR_PTR, but some code believes
    it does.  From Dan Carpenter.

14) Fix regression in wireless SME disconnects, from Johannes Berg.

15) Don't use a stack buffer for DMA in zd1201 USB wireless driver, from
    Jussi Kivilinna.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (33 commits)
  ipv4: expose IPV4_DEVCONF
  ipv6: handle Redirect ICMP Message with no Redirected Header option
  be2net: fix disabling TX in be_close()
  Revert "genetlink: fix family dump race"
  hso: Fix stack corruption on some architectures
  hso: Earlier catch of error condition
  sfc: Fix lookup of default RX MAC filters when steered using ethtool
  bridge: Use the correct bit length for bitmap functions in the VLAN code
  packet: restore packet statistics tp_packets to include drops
  net: phy: rtl8211: fix interrupt on status link change
  r8169: remember WOL preferences on driver load
  via-ircc: don't return zero if via_ircc_open() failed
  macvtap: Ignore tap features when VNET_HDR is off
  macvtap: Correctly set tap features when IFF_VNET_HDR is disabled.
  macvtap: simplify usage of tap_features
  tcp: set timestamps for restored skb-s
  bnx2x: set VF DMAE when first function has 0 supported VFs
  bnx2x: Protect against VFs' ndos when SR-IOV is disabled
  bnx2x: prevent VF benign attentions
  bnx2x: Consider DCBX remote error
  ...

Merge fixes from Andrew Morton:
 "A few fixes.  One is a licensing change and I don't do licensing, so
  please eyeball that one"

Licensing eye-balled.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  lib/lz4: correct the LZ4 license
  memcg: get rid of swapaccount leftovers
  nilfs2: fix issue with counting number of bio requests for BIO_EOPNOTSUPP error detection
  nilfs2: remove double bio_put() in nilfs_end_bio_write() for BIO_EOPNOTSUPP error
  drivers/platform/olpc/olpc-ec.c: initialise earlier

The LZ4 code is listed as using the "BSD 2-Clause License".
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Acked-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: Chanho Min <chanho.min@lge.com>
Cc: Richard Yao <ryao@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ The 2-clause BSD can be just converted into GPL, but that's rude and
  pointless, so don't do it   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The swapaccount kernel parameter without any values has been removed by
commit a2c8990a ("memsw: remove noswapaccount kernel parameter") but
it seems that we didn't get rid of all the left overs.

Make sure that menuconfig help text and kernel-parameters.txt are clear
about value for the paramter and remove the stalled comment which is not
very much useful on its own.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Gergely Risko <gergely@risko.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix the issue with improper counting number of flying bio requests for
BIO_EOPNOTSUPP error detection case.

The sb_nbio must be incremented exactly the same number of times as
complete() function was called (or will be called) because
nilfs_segbuf_wait() will call wail_for_completion() for the number of
times set to sb_nbio:

  do {
      wait_for_completion(&segbuf->sb_bio_event);
  } while (--segbuf->sb_nbio > 0);

Two functions complete() and wait_for_completion() must be called the
same number of times for the same sb_bio_event.  Otherwise,
wait_for_completion() will hang or leak.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>