Pull ARM SoC driver update from Kevin Hilman:
 "This contains the ARM SoC related driver updates for v3.12.  The only
  thing this cycle are core PM updates and CPUidle support for ARM's TC2
  big.LITTLE development platform"

* tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  cpuidle: big.LITTLE: vexpress-TC2 CPU idle driver
  ARM: vexpress: tc2: disable GIC CPU IF in tc2_pm_suspend
  drivers: irq-chip: irq-gic: introduce gic_cpu_if_down()

Pull clock framework changes from Michael Turquette:
 "The common clk framework changes for 3.12 are dominated by clock
  driver patches, both new drivers and fixes to existing.  A high
  percentage of these are for Samsung platforms like Exynos.  Core
  framework fixes and some new features like automagical clock
  re-parenting round out the patches"

* tag 'clk-for-linus-3.12' of git://git.linaro.org/people/mturquette/linux: (102 commits)
  clk: only call get_parent if there is one
  clk: samsung: exynos5250: Simplify registration of PLL rate tables
  clk: samsung: exynos4: Register PLL rate tables for Exynos4x12
  clk: samsung: exynos4: Register PLL rate tables for Exynos4210
  clk: samsung: exynos4: Reorder registration of mout_vpllsrc
  clk: samsung: pll: Add support for rate configuration of PLL46xx
  clk: samsung: pll: Use new registration method for PLL46xx
  clk: samsung: pll: Add support for rate configuration of PLL45xx
  clk: samsung: pll: Use new registration method for PLL45xx
  clk: samsung: exynos4: Rename exynos4_plls to exynos4x12_plls
  clk: samsung: exynos4: Remove checks for DT node
  clk: samsung: exynos4: Remove unused static clkdev aliases
  clk: samsung: Modify _get_rate() helper to use __clk_lookup()
  clk: samsung: exynos4: Use separate aliases for cpufreq related clocks
  clocksource: samsung_pwm_timer: Get clock from device tree
  ARM: dts: exynos4: Specify PWM clocks in PWM node
  pwm: samsung: Update DT bindings documentation to cover clocks
  clk: Move symbol export to proper location
  clk: fix new_parent dereference before null check
  clk: wm831x: Initialise wm831x pointer on init
  ...

Pull tracing updates from Steven Rostedt:
 "Not much changes for the 3.12 merge window.  The major tracing changes
  are still in flux, and will have to wait for 3.13.

  The changes for 3.12 are mostly clean ups and minor fixes.

  H Peter Anvin added a check to x86_32 static function tracing that
  helps a small segment of the kernel community.

  Oleg Nesterov had a few changes from 3.11, but were mostly clean ups
  and not worth pushing in the -rc time frame.

  Li Zefan had small clean up with annotating a raw_init with __init.

  I fixed a slight race in updating function callbacks, but the race is
  so small and the bug that happens when it occurs is so minor it's not
  even worth pushing to stable.

  The only real enhancement is from Alexander Z Lam that made the
  tracing_cpumask work for trace buffer instances, instead of them all
  sharing a global cpumask"

* tag 'trace-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/rcu: Do not trace debug_lockdep_rcu_enabled()
  x86-32, ftrace: Fix static ftrace when early microcode is enabled
  ftrace: Fix a slight race in modifying what function callback gets traced
  tracing: Make tracing_cpumask available for all instances
  tracing: Kill the !CONFIG_MODULES code in trace_events.c
  tracing: Don't pass file_operations array to event_create_dir()
  tracing: Kill trace_create_file_ops() and friends
  tracing/syscalls: Annotate raw_init function with __init

In __clk_init(), after a clock is mostly initialized, a scan is done
of the orphan clocks to see if the clock being registered is the
parent of any of them.

This code assumes that any clock that provides a get_parent method
actually has at least one parent, and that's not a valid assumption.

As a result, an orphan clock with no parent can return *something*
as the parent index, and that value is blindly used to dereference
the orphan's parent_names[] array (which will be ZERO_SIZE_PTR or
NULL).

Fix this by ensuring get_parent is only called for orphans with at
least one parent.
Signed-off-by: NAlex Elder <elder@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Pull xfs updates from Ben Myers:
 "For 3.12-rc1 there are a number of bugfixes in addition to work to
  ease usage of shared code between libxfs and the kernel, the rest of
  the work to enable project and group quotas to be used simultaneously,
  performance optimisations in the log and the CIL, directory entry file
  type support, fixes for log space reservations, some spelling/grammar
  cleanups, and the addition of user namespace support.

   - introduce readahead to log recovery
   - add directory entry file type support
   - fix a number of spelling errors in comments
   - introduce new Q_XGETQSTATV quotactl for project quotas
   - add USER_NS support
   - log space reservation rework
   - CIL optimisations
  - kernel/userspace libxfs rework"

* tag 'xfs-for-linus-v3.12-rc1' of git://oss.sgi.com/xfs/xfs: (112 commits)
  xfs: XFS_MOUNT_QUOTA_ALL needed by userspace
  xfs: dtype changed xfs_dir2_sfe_put_ino to xfs_dir3_sfe_put_ino
  Fix wrong flag ASSERT in xfs_attr_shortform_getvalue
  xfs: finish removing IOP_* macros.
  xfs: inode log reservations are too small
  xfs: check correct status variable for xfs_inobt_get_rec() call
  xfs: inode buffers may not be valid during recovery readahead
  xfs: check LSN ordering for v5 superblocks during recovery
  xfs: btree block LSN escaping to disk uninitialised
  XFS: Assertion failed: first <= last && last < BBTOB(bp->b_length), file: fs/xfs/xfs_trans_buf.c, line: 568
  xfs: fix bad dquot buffer size in log recovery readahead
  xfs: don't account buffer cancellation during log recovery readahead
  xfs: check for underflow in xfs_iformat_fork()
  xfs: xfs_dir3_sfe_put_ino can be static
  xfs: introduce object readahead to log recovery
  xfs: Simplify xfs_ail_min() with list_first_entry_or_null()
  xfs: Register hotcpu notifier after initialization
  xfs: add xfs sb v4 support for dirent filetype field
  xfs: Add write support for dirent filetype field
  xfs: Add read-only support for dirent filetype field
  ...

Not using the return value can in the generic case be racy, so it's
in general good practice to check the return value instead.

This also resolved the warning caused on ARM and other architectures:

  fs/direct-io.c: In function 'sb_init_dio_done_wq':
  fs/direct-io.c:557:2: warning: value computed is not used [-Wunused-value]
Signed-off-by: NOlof Johansson <olof@lixom.net>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: H Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull mtd updates from David Woodhouse:
 - factor out common code from MTD tests
 - nand-gpio cleanup and portability to non-ARM
 - m25p80 support for 4-byte addressing chips, other new chips
 - pxa3xx cleanup and support for new platforms
 - remove obsolete alauda, octagon-5066 drivers
 - erase/write support for bcm47xxsflash
 - improve detection of ECC requirements for NAND, controller setup
 - NFC acceleration support for atmel-nand, read/write via SRAM
 - etc

* tag 'for-linus-20130909' of git://git.infradead.org/linux-mtd: (184 commits)
  mtd: chips: Add support for PMC SPI Flash chips in m25p80.c
  mtd: ofpart: use for_each_child_of_node() macro
  mtd: mtdswap: replace strict_strtoul() with kstrtoul()
  mtd cs553x_nand: use kzalloc() instead of memset
  mtd: atmel_nand: fix error return code in atmel_nand_probe()
  mtd: bcm47xxsflash: writing support
  mtd: bcm47xxsflash: implement erasing support
  mtd: bcm47xxsflash: convert to module_platform_driver instead of init/exit
  mtd: bcm47xxsflash: convert kzalloc to avoid invalid access
  mtd: remove alauda driver
  mtd: nand: mxc_nand: mark 'const' properly
  mtd: maps: cfi_flagadm: add missing __iomem annotation
  mtd: spear_smi: add missing __iomem annotation
  mtd: r852: Staticize local symbols
  mtd: nandsim: Staticize local symbols
  mtd: impa7: add missing __iomem annotation
  mtd: sm_ftl: Staticize local symbols
  mtd: m25p80: add support for mr25h10
  mtd: m25p80: make CONFIG_M25PXX_USE_FAST_READ safe to enable
  mtd: m25p80: Pass flags through CAT25_INFO macro
  ...

Pull firewire updates from Stefan Richter:

 - Fix a regression since 3.2 inclusive: The subsystem workqueue
   deadlocked between transaction completion handling and bus reset
   handling if the worker pool could not be increased in time.

 - janitorial updates

* tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: ohci: Fix deadlock at bus reset
  firewire: ohci: Change module_pci_driver to module_init/module_exit
  firewire: ohci: beautify some macro definitions
  firewire: ohci: change confusing name of a struct member
  firewire: core: typecast from gfp_t to bool more safely
  firewire: WQ_NON_REENTRANT is meaningless and going away

Pull DMA mapping update from Marek Szyprowski:
 "This contains an addition of Device Tree support for reserved memory
  regions (Contiguous Memory Allocator is one of the drivers for it) and
  changes required by the KVM extensions for PowerPC architectue"

* 'for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: init: add support for reserved memory defined by device tree
  drivers: of: add initialization code for dma reserved memory
  drivers: of: add function to scan fdt nodes given by path
  drivers: dma-contiguous: clean source code and prepare for device tree

Pull virtio update from Rusty Russell:
 "More console fixes; these are the theoretical ones which didn't get
  CC:stable.  But for that reason, I did a merge with master partway
  through to avoid an unnecessary conflict.

  Also: a fun lguest bug turns out if you don't clear the TF flag when
  trapping Bad Things happen to the guest kernel as the stack
  overflows..."

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio_pci: pm: Use CONFIG_PM_SLEEP instead of CONFIG_PM
  lguest: fix GPF in guest when using gdb.
  lguest: fix guest kernel stack overflow when TF bit set.
  lguest: fix BUG_ON() in invalid guest page table.
  virtio: console: prevent use-after-free of port name in port unplug
  virtio: console: cleanup an error message
  virtio: console: fix locking around send_sigio_to_port()
  virtio: console: add locking in port unplug path
  virtio: console: add locks around buffer removal in port unplug path
  tools/lguest: offer VIRTIO_F_ANY_LAYOUT for net device.
  virtio tools: add .gitignore
  lguest: Point to the right directory for the lguest launcher

Pull VFIO update from Alex Williamson:
 "VFIO updates include safer default file flags for VFIO device fds, an
  external user interface exported to allow other modules to hold
  references to VFIO groups, a fix to test for extended config space on
  PCIe and PCI-x, and new hot reset interfaces for PCI devices which
  allows the user to do PCI bus/slot resets when all of the devices
  affected by the reset are owned by the user.

  For this last feature, the PCI bus reset interface, I depend on
  changes already merged from Bjorn's PCI pull request.  I therefore
  merged my tree up to commit cb3e4330, which I think was the correct
  action, but as Stephen Rothwell noted, I failed to provide a commit
  message indicating why the merge was required.  Sorry for that.
  Thanks, Alex"

* tag 'vfio-v3.12-rc0' of git://github.com/awilliam/linux-vfio:
  vfio: fix documentation
  vfio-pci: PCI hot reset interface
  vfio-pci: Test for extended config space
  vfio-pci: Use fdget() rather than eventfd_fget()
  vfio: Add O_CLOEXEC flag to vfio device fd
  vfio: use get_unused_fd_flags(0) instead of get_unused_fd()
  vfio: add external user support

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

   - Fix NFSv4 recovery so that it doesn't recover lost locks in cases
     such as lease loss due to a network partition, where doing so may
     result in data corruption.  Add a kernel parameter to control
     choice of legacy behaviour or not.
   - Performance improvements when 2 processes are writing to the same
     file.
   - Flush data to disk when an RPCSEC_GSS session timeout is imminent.
   - Implement NFSv4.1 SP4_MACH_CRED state protection to prevent other
     NFS clients from being able to manipulate our lease and file
     locking state.
   - Allow sharing of RPCSEC_GSS caches between different rpc clients.
   - Fix the broken NFSv4 security auto-negotiation between client and
     server.
   - Fix rmdir() to wait for outstanding sillyrename unlinks to complete
   - Add a tracepoint framework for debugging NFSv4 state recovery
     issues.
   - Add tracing to the generic NFS layer.
   - Add tracing for the SUNRPC socket connection state.
   - Clean up the rpc_pipefs mount/umount event management.
   - Merge more patches from Chuck in preparation for NFSv4 migration
     support"

* tag 'nfs-for-3.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (107 commits)
  NFSv4: use mach cred for SECINFO_NO_NAME w/ integrity
  NFS: nfs_compare_super shouldn't check the auth flavour unless 'sec=' was set
  NFSv4: Allow security autonegotiation for submounts
  NFSv4: Disallow security negotiation for lookups when 'sec=' is specified
  NFSv4: Fix security auto-negotiation
  NFS: Clean up nfs_parse_security_flavors()
  NFS: Clean up the auth flavour array mess
  NFSv4.1 Use MDS auth flavor for data server connection
  NFS: Don't check lock owner compatability unless file is locked (part 2)
  NFS: Don't check lock owner compatibility in writes unless file is locked
  nfs4: Map NFS4ERR_WRONG_CRED to EPERM
  nfs4.1: Add SP4_MACH_CRED write and commit support
  nfs4.1: Add SP4_MACH_CRED stateid support
  nfs4.1: Add SP4_MACH_CRED secinfo support
  nfs4.1: Add SP4_MACH_CRED cleanup support
  nfs4.1: Add state protection handler
  nfs4.1: Minimal SP4_MACH_CRED implementation
  SUNRPC: Replace pointer values with task->tk_pid and rpc_clnt->cl_clid
  SUNRPC: Add an identifier for struct rpc_clnt
  SUNRPC: Ensure rpc_task->tk_pid is available for tracepoints
  ...

Pull fuse bugfixes from Miklos Szeredi:
 "Just a bunch of bugfixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: use list_for_each_entry() for list traversing
  fuse: readdir: check for slash in names
  fuse: hotfix truncate_pagecache() issue
  fuse: invalidate inode attributes on xattr modification
  fuse: postpone end_page_writeback() in fuse_writepage_locked()

Pull GFS2 updates from Steven Whitehouse:
 "This is possibly the smallest ever set of GFS2 patches for a merge
  window.  Also, most of them are bug fixes this time.

  Two of my three patches (moving gfs2_sync_meta and merging the two
  writepage implementations) are clean ups with the third (taking the
  glock ref in examine_bucket) being a fix for a difficult to hit race
  condition.

  The removal of an unused memory barrier is a clean up from Bob
  Peterson, and the "spectator" relates to a rarely used mount option.
  Ben Marzinski's patch fixes a corner case where the incorrect inode
  flags were being set, resulting in incorrect behaviour on fsync"

* tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
  GFS2: dirty inode correctly in gfs2_write_end
  GFS2: Don't flag consistency error if first mounter is a spectator
  GFS2: Remove unnecessary memory barrier
  GFS2: Merge ordered and writeback writepage
  GFS2: Take glock reference in examine_bucket()
  GFS2: Move gfs2_sync_meta to lops.c

Pull ceph updates from Sage Weil:
 "This includes both the first pile of Ceph patches (which I sent to
  torvalds@vger, sigh) and a few new patches that add support for
  fscache for Ceph.  That includes a few fscache core fixes that David
  Howells asked go through the Ceph tree.  (Thanks go to Milosz Tanski
  for putting this feature together)

  This first batch of patches (included here) had (has) several
  important RBD bug fixes, hole punch support, several different
  cleanups in the page cache interactions, improvements in the truncate
  code (new truncate mutex to avoid shenanigans with i_mutex), and a
  series of fixes in the synchronous striping read/write code.

  On top of that is a random collection of small fixes all across the
  tree (error code checks and error path cleanup, obsolete wq flags,
  etc)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (43 commits)
  ceph: use d_invalidate() to invalidate aliases
  ceph: remove ceph_lookup_inode()
  ceph: trivial buildbot warnings fix
  ceph: Do not do invalidate if the filesystem is mounted nofsc
  ceph: page still marked private_2
  ceph: ceph_readpage_to_fscache didn't check if marked
  ceph: clean PgPrivate2 on returning from readpages
  ceph: use fscache as a local presisent cache
  fscache: Netfs function for cleanup post readpages
  FS-Cache: Fix heading in documentation
  CacheFiles: Implement interface to check cache consistency
  FS-Cache: Add interface to check consistency of a cached object
  rbd: fix null dereference in dout
  rbd: fix buffer size for writes to images with snapshots
  libceph: use pg_num_mask instead of pgp_num_mask for pg.seed calc
  rbd: fix I/O error propagation for reads
  ceph: use vfs __set_page_dirty_nobuffers interface instead of doing it inside filesystem
  ceph: allow sync_read/write return partial successed size of read/write.
  ceph: fix bugs about handling short-read for sync read mode.
  ceph: remove useless variable revoked_rdcache
  ...

Pull metag architecture changes from James Hogan:
 - Device tree updates for TZ1090 GPIO drivers merged via GPIO tree.
 - Add driver for ImgTec PDC irqchip as found in TZ1090 SoC.
 - Add linux-metag mailing list to MAINTAINERS file.

* tag 'metag-for-v3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
  irq-imgpdc: add ImgTec PDC irqchip driver
  MAINTAINERS: add linux-metag mailing list
  metag: tz1090: instantiate gpio-tz1090-pdc
  metag: tz1090: select and instantiate gpio-tz1090
  metag: tz1090: select and instantiate irq-imgpdc

Pull ARC changes from Vineet Gupta:

 - ARC MM changes:
    - preparation for MMUv4 (accomodate new PTE bits, new cmds)
    - Rework the ASID allocation algorithm to remove asid-mm reverse map
 - Boilerplate code consolidation in Exception Handlers
 - Disable FRAME_POINTER for ARC
 - Unaligned Access Emulation for Big-Endian from Noam
 - Bunch of fixes (udelay, missing accessors) from Mischa

* tag 'arc-v3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: fix new Section mismatches in build (post __cpuinit cleanup)
  Kconfig.debug: Add FRAME_POINTER anti-dependency for ARC
  ARC: Fix __udelay calculation
  ARC: remove console_verbose() from setup_arch()
  ARC: Add read*_relaxed to asm/io.h
  ARC: Handle un-aligned user space access in BE.
  ARC: [ASID] Track ASID allocation cycles/generations
  ARC: [ASID] activate_mm() == switch_mm()
  ARC: [ASID] get_new_mmu_context() to conditionally allocate new ASID
  ARC: [ASID] Refactor the TLB paranoid debug code
  ARC: [ASID] Remove legacy/unused debug code
  ARC: No need to flush the TLB in early boot
  ARC: MMUv4 preps/3 - Abstract out TLB Insert/Delete
  ARC: MMUv4 preps/2 - Reshuffle PTE bits
  ARC: MMUv4 preps/1 - Fold PTE K/U access flags
  ARC: Code cosmetics (Nothing semantical)
  ARC: Entry Handler tweaks: Optimize away redundant IRQ_DISABLE_SAVE
  ARC: Exception Handlers Code consolidation
  ARC: Add some .gitignore entries

Pull m68knommu fixes from Greg Ungerer:
 "Just a small collection of cleanups and fixes this time, no big
  changes.  The most interresting are to make the m68k and m68knommu
  consistently use CONFIG_IOMAP, clean out some unused board config
  options and flush the cache on signal stack creation"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68k: remove 16 unused boards in Kconfig.machine
  m68k: define 'VM_DATA_DEFAULT_FLAGS' no matter whether has 'NOMMU' or not
  m68knommu: user generic iomap to support ioread*/iowrite*
  m68k/coldfire: flush cache when creating the signal stack frame
  m68knommu: Mark functions only called from setup_arch() __init

Pull UML updates from Richard Weinberger:
 "This pile contains mostly fixes and improvements for issues identified
  by Richard W M Jones while adding UML as backend to libguestfs"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Add irq chip um/mask handlers
  um: prctl: Do not include linux/ptrace.h
  um: Run UML in it's own session.
  um: Cleanup SIGTERM handling
  um: ubd: Introduce submit_request()
  um: ubd: Add REQ_FLUSH suppport
  um: Implement probe_kernel_read()
  um: hostfs: Fix writeback

This is the fix that the last two commits indirectly led up to - making
sure that we don't call dput() in a bad context on the dentries we've
looked up in RCU mode after the sequence count validation fails.

This basically expands d_rcu_to_refcount() into the callers, and then
fixes the callers to delay the dput() in the failure case until _after_
we've dropped all locks and are no longer in an RCU-locked region.

The case of 'complete_walk()' was trivial, since its failure case did
the unlock_rcu_walk() directly after the call to d_rcu_to_refcount(),
and as such that is just a pure expansion of the function with a trivial
movement of the resulting dput() to after 'unlock_rcu_walk()'.

In contrast, the unlazy_walk() case was much more complicated, because
not only does convert two different dentries from RCU to be reference
counted, but it used to not call unlock_rcu_walk() at all, and instead
just returned an error and let the caller clean everything up in
"terminate_walk()".

Happily, one of the dentries in question (called "parent" inside
unlazy_walk()) is the dentry of "nd->path", which terminate_walk() wants
a refcount to anyway for the non-RCU case.

So what the new and improved unlazy_walk() does is to first turn that
dentry into a refcounted one, and once that is set up, the error cases
can continue to use the terminate_walk() helper for cleanup, but for the
non-RCU case.  Which makes it possible to drop out of RCU mode if we
actually hit the sequence number failure case.
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The virtio_pci_freeze/restore are defined under CONFIG_PM but is used
by SET_SYSTEM_SLEEP_PM_OPS macro, which is defined under
CONFIG_PM_SLEEP. So if CONFIG_PM_SLEEP is not cofigured but
CONFIG_PM_RUNTIME is, the following warning message appeared:

drivers/virtio/virtio_pci.c:770:12: warning: ‘virtio_pci_freeze’ defined but not used [-Wunused-function]
 static int virtio_pci_freeze(struct device *dev)
            ^
drivers/virtio/virtio_pci.c:790:12: warning: ‘virtio_pci_restore’ defined but not used [-Wunused-function]
 static int virtio_pci_restore(struct device *dev)
            ^
Fix it by changing CONFIG_PM to CONFIG_PM_SLEEP.
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This simplifies the RCU to refcounting code in particular.

I was originally intending to leave this for later, but walking through
all the dput() logic (see previous commit), I realized that the dput()
"might_sleep()" check was misleadingly weak.  And I removed it as
misleading, both for performance profiling and for debugging.

However, the might_sleep() debugging case is actually true: the final
dput() can indeed sleep, if the inode of the dentry that you are
releasing ends up sleeping at iput time (see dentry_iput()).  So the
problem with the might_sleep() in dput() wasn't that it wasn't true, it
was that it wasn't actually testing and triggering on the interesting
case.

In particular, just about *any* dput() can indeed sleep, if you happen
to race with another thread deleting the file in question, and you then
lose the race to the be the last dput() for that file.  But because it's
a very rare race, the debugging code would never trigger it in practice.

Why is this problematic? The new d_rcu_to_refcount() (see commit
15570086: "vfs: reimplement d_rcu_to_refcount() using
lockref_get_or_lock()") does a dput() for the failure case, and it does
it under the RCU lock.  So potentially sleeping really is a bug.

But there's no way I'm going to fix this with the previous complicated
"lockref_get_or_lock()" interface.  And rather than revert to the old
and crufty nested dentry locking code (which did get this right by
delaying the reference count updates until they were verified to be
safe), let's make forward progress.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is me being a bit OCD after all the dentry optimization work this
merge window: profiles end up showing 'dput()' as a rather expensive
operation, and there were two unrelated bad reasons for that.

The first reason was reading d_lockref.count for debugging purposes,
which touches the lockref cacheline (for reads) before really need to.
More importantly, the debugging test in question is _wrong_, and has
hidden bugs.  It's true that we can only sleep when the count goes down
to zero, but the test as-is hides the much more subtle bug that happens
if we race with somebody else deleting the file.

Anyway we _will_ touch that cacheline, but let's do it for a write and
in the right routine (ie in "lockref_put_or_lock()") which annotates the
costs better.  So remove the misleading debug code.

The other was an unnecessary access to the cacheline that contains the
d_lru list, just to check whether we already were on the LRU list or
not.  This is exactly what we have d_flags for, so that we can avoid
touching extra cache lines for the common case.  So just add another bit
for "is this dentry on the LRU".

Finally, mark the tests properly likely/unlikely, so that the common
fast-paths are dense in the instruction stream.

This makes the profiles look much saner.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull NVM Express driver update from Matthew Wilcox.

* git://git.infradead.org/users/willy/linux-nvme:
  NVMe: Merge issue on character device bring-up
  NVMe: Handle ioremap failure
  NVMe: Add pci suspend/resume driver callbacks
  NVMe: Use normal shutdown
  NVMe: Separate controller init from disk discovery
  NVMe: Separate queue alloc/free from create/delete
  NVMe: Group pci related actions in functions
  NVMe: Disk stats for read/write commands only
  NVMe: Bring up cdev on set feature failure
  NVMe: Fix checkpatch issues
  NVMe: Namespace IDs are unsigned
  NVMe: Update nvme_id_power_state with latest spec
  NVMe: Split header file into user-visible and kernel-visible pieces
  NVMe: Call nvme_process_cq from submission path
  NVMe: Remove "process_cq did something" message
  NVMe: Return correct value from interrupt handler
  NVMe: Disk IO statistics
  NVMe: Restructure MSI / MSI-X setup
  NVMe: Use kzalloc instead of kmalloc+memset

Pull NTB (non-transparent bridge) updates from Jon Mason:
 "NTB driver bug fixes to address issues in NTB-RP enablement, spad,
  debugfs, and USD/DSD identification.

  Add a workaround on Xeon NTB devices for b2bdoorbell errata.  Also,
  add new NTB driver features to support 32bit x86, DMA engine support,
  and NTB-RP support.

  Finally, a few clean-ups and update to MAINTAINERS for the NTB git
  tree and wiki location"

* tag 'ntb-3.12' of git://github.com/jonmason/ntb:
  ntb: clean up unnecessary MSI/MSI-X capability find
  MAINTAINERS: Add Website and Git Tree for NTB
  NTB: Update Version
  NTB: Comment Fix
  NTB: Remove unused variable
  NTB: Remove References of non-B2B BWD HW
  NTB: NTB-RP support
  NTB: Rename Variables for NTB-RP
  NTB: Use DMA Engine to Transmit and Receive
  NTB: Enable 32bit Support
  NTB: Update Device IDs
  NTB: BWD Link Recovery
  NTB: Xeon Errata Workaround
  NTB: Correct debugfs to work with more than 1 NTB Device
  NTB: Correct USD/DSD Identification
  NTB: Correct Number of Scratch Pad Registers
  NTB: Add Error Handling in ntb_device_setup

Pull MFD (multi-function device) updates from Samuel Ortiz:
 "For the 3.12 merge window we have one new driver for the DA9063 PMIC
  from Dialog Semiconductor.

  Besides that driver we also have:

   - Device tree support for the s2mps11 driver

   - More devm_* conversion for the pm8921, max89xx, menelaus, tps65010,
     wl1273 and pcf50633-adc drivers.

   - A conversion to threaded IRQ and IRQ domain for the twl6030 driver.

   - A fairly big update for the rtsx driver: Better power saving
     support, better vendor settings handling, and a few fixes.

   - Support for a couple more boards (COMe-bHL6 and COMe-cTH6) for the
     Kontron driver.

   - A conversion to the dev_get_platdata() API for all MFD drivers.

   - A removal of non-DT (legacy) support for the twl6040 driver.

   - A few fixes and additions (Mic detect level) to the wm5110 register
     tables.

   - Regmap support for the davinci_voicecodec driver.

   - The usual bunch of minor cleanups and janitorial fixes"

* tag 'mfd-3.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-next: (81 commits)
  mfd: ucb1x00-core: Rewrite ucb1x00_add_dev()
  mfd: ab8500-debugfs: Apply a check for -ENOMEM after allocating memory for event name
  mfd: ab8500-debugfs: Apply a check for -ENOMEM after allocating memory for sysfs
  mfd: timberdale: Use module_pci_driver
  mfd: timberdale: Remove redundant break
  mfd: timberdale: Staticize local variables
  mfd: ab8500-debugfs: Staticize local variables
  mfd: db8500-prcmu: Staticize clk_mgt
  mfd: db8500-prcmu: Use ANSI function declaration
  mfd: omap-usb-host: Staticize usbhs_driver_name
  mfd: 88pm805: Fix potential NULL pdata dereference
  mfd: 88pm800: Fix potential NULL pdata dereference
  mfd: twl6040: Use regmap for register cache
  mfd: davinci_voicecodec: Provide a regmap for register I/O
  mfd: davinci_voicecodec: Remove unused read and write functions
  mmc: memstick: rtsx: Modify copyright comments
  mmc: rtsx: Clear SD_CLK toggle enable bit if switching voltage fail
  mfd: mmc: rtsx: Change default tx phase
  mfd: pcf50633-adc: Use devm_*() functions
  mfd: rtsx: Copyright modifications
  ...

Pull misc kbuild updates from Michal Marek:
 "In the kbuild misc branch, I have:
   - make rpm-pkg updates, most importantly the rpm package now calls
     /sbin/installkernel
   - make deb-pkg: debuginfo split, correct kernel image path for
     parisc, mips and powerpc and a couple more minor fixes
   - New coccinelle check"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  scripts/checkkconfigsymbols.sh: replace echo -e with printf
  Provide version number for Debian firmware package
  coccinelle: replace 0/1 with false/true in functions returning bool
  deb-pkg: add a hook argument to match debian hooks parameters
  deb-pkg: fix installed image path on parisc, mips and powerpc
  deb-pkg: split debug symbols in their own package
  deb-pkg: use KCONFIG_CONFIG instead of .config file directly
  rpm-pkg: add generation of kernel-devel
  rpm-pkg: install firmware files in kernel relative directory
  rpm-pkg: add %post section to create initramfs and grub hooks

Pull kbuild update from Michal Marek:
 "Only these two commits are in the kbuild branch this time:
   - Using filechk for include/config/kernel.release
   - Cleanup in scripts/sortextable.c"

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Do not overwrite include/config/kernel.release needlessly
  scripts: remove unused function in sortextable.c

The only actual current lockref user (dcache) uses zero reference counts
even for perfectly live dentries, because it's a cache: there may not be
any users, but that doesn't mean that we want to throw away the dentry.

At the same time, the dentry cache does have a notion of a truly "dead"
dentry that we must not even increment the reference count of, because
we have pruned it and it is not valid.

Currently that distinction is not visible in the lockref itself, and the
dentry cache validation uses "lockref_get_or_lock()" to either get a new
reference to a dentry that already had existing references (and thus
cannot be dead), or get the dentry lock so that we can then verify the
dentry and increment the reference count under the lock if that
verification was successful.

That's all somewhat complicated.

This adds the concept of being "dead" to the lockref itself, by simply
using a count that is negative.  This allows a usage scenario where we
can increment the refcount of a dentry without having to validate it,
and pushing the special "we killed it" case into the lockref code.

The dentry code itself doesn't actually use this yet, and it's probably
too late in the merge window to do that code (the dentry_kill() code
with its "should I decrement the count" logic really is pretty complex
code), but let's introduce the concept at the lockref level now.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 97431204 introduced a regression
that causes SECINFO_NO_NAME to fail without sending an RPC if:

 1) the nfs_client's rpc_client is using krb5i/p (now tried by default)
 2) the current user doesn't have valid kerberos credentials

This situation is quite common - as of now a sec=sys mount would use
krb5i for the nfs_client's rpc_client and a user would hardly be faulted
for not having run kinit.

The solution is to use the machine cred when trying to use an integrity
protected auth flavor for SECINFO_NO_NAME.

Older servers may not support using the machine cred or an integrity
protected auth flavor for SECINFO_NO_NAME in every circumstance, so we fall
back to using the user's cred and the filesystem's auth flavor in this case.

We run into another problem when running against linux nfs servers -
they return NFS4ERR_WRONGSEC when using integrity auth flavor (unless the
mount is also that flavor) even though that is not a valid error for
SECINFO*.  Even though it's against spec, handle WRONGSEC errors on
SECINFO_NO_NAME by falling back to using the user cred and the
filesystem's auth flavor.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Also don't worry about obsolete mount flags...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The code got rewritten, but the comments got copied as-is from older
versions, and as a result the argument name in the comment didn't
actually match the code any more.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In cases where the parent super block was not mounted with a 'sec=' line,
allow autonegotiation of security for the submounts.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Ensure that nfs4_proc_lookup_common respects the NFS_MOUNT_SECFLAVOUR
flag.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Pull vfs pile 2 (of many) from Al Viro:
 "Mostly Miklos' series this time"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  constify dcache.c inlined helpers where possible
  fuse: drop dentry on failed revalidate
  fuse: clean up return in fuse_dentry_revalidate()
  fuse: use d_materialise_unique()
  sysfs: use check_submounts_and_drop()
  nfs: use check_submounts_and_drop()
  gfs2: use check_submounts_and_drop()
  afs: use check_submounts_and_drop()
  vfs: check unlinked ancestors before mount
  vfs: check submounts and drop atomically
  vfs: add d_walk()
  vfs: restructure d_genocide()

Pull namespace changes from Eric Biederman:
 "This is an assorted mishmash of small cleanups, enhancements and bug
  fixes.

  The major theme is user namespace mount restrictions.  nsown_capable
  is killed as it encourages not thinking about details that need to be
  considered.  A very hard to hit pid namespace exiting bug was finally
  tracked and fixed.  A couple of cleanups to the basic namespace
  infrastructure.

  Finally there is an enhancement that makes per user namespace
  capabilities usable as capabilities, and an enhancement that allows
  the per userns root to nice other processes in the user namespace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns:  Kill nsown_capable it makes the wrong thing easy
  capabilities: allow nice if we are privileged
  pidns: Don't have unshare(CLONE_NEWPID) imply CLONE_THREAD
  userns: Allow PR_CAPBSET_DROP in a user namespace.
  namespaces: Simplify copy_namespaces so it is clear what is going on.
  pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeup
  sysfs: Restrict mounting sysfs
  userns: Better restrictions on when proc and sysfs can be mounted
  vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces
  kernel/nsproxy.c: Improving a snippet of code.
  proc: Restrict mounting the proc filesystem
  vfs: Lock in place mounts from more privileged users

Pull security subsystem updates from James Morris:
 "Nothing major for this kernel, just maintenance updates"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (21 commits)
  apparmor: add the ability to report a sha1 hash of loaded policy
  apparmor: export set of capabilities supported by the apparmor module
  apparmor: add the profile introspection file to interface
  apparmor: add an optional profile attachment string for profiles
  apparmor: add interface files for profiles and namespaces
  apparmor: allow setting any profile into the unconfined state
  apparmor: make free_profile available outside of policy.c
  apparmor: rework namespace free path
  apparmor: update how unconfined is handled
  apparmor: change how profile replacement update is done
  apparmor: convert profile lists to RCU based locking
  apparmor: provide base for multiple profiles to be replaced at once
  apparmor: add a features/policy dir to interface
  apparmor: enable users to query whether apparmor is enabled
  apparmor: remove minimum size check for vmalloc()
  Smack: parse multiple rules per write to load2, up to PAGE_SIZE-1 bytes
  Smack: network label match fix
  security: smack: add a hash table to quicken smk_find_entry()
  security: smack: fix memleak in smk_write_rules_list()
  xattr: Constify ->name member of "struct xattr".
  ...

Pull crypto update from Herbert Xu:
 "Here is the crypto update for 3.12:

   - Added MODULE_SOFTDEP to allow pre-loading of modules.
   - Reinstated crct10dif driver using the module softdep feature.
   - Allow via rng driver to be auto-loaded.

   - Split large input data when necessary in nx.
   - Handle zero length messages correctly for GCM/XCBC in nx.
   - Handle SHA-2 chunks bigger than block size properly in nx.

   - Handle unaligned lengths in omap-aes.
   - Added SHA384/SHA512 to omap-sham.
   - Added OMAP5/AM43XX SHAM support.
   - Added OMAP4 TRNG support.

   - Misc fixes"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (66 commits)
  Reinstate "crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework"
  hwrng: via - Add MODULE_DEVICE_TABLE
  crypto: fcrypt - Fix bitoperation for compilation with clang
  crypto: nx - fix SHA-2 for chunks bigger than block size
  crypto: nx - fix GCM for zero length messages
  crypto: nx - fix XCBC for zero length messages
  crypto: nx - fix limits to sg lists for AES-CCM
  crypto: nx - fix limits to sg lists for AES-XCBC
  crypto: nx - fix limits to sg lists for AES-GCM
  crypto: nx - fix limits to sg lists for AES-CTR
  crypto: nx - fix limits to sg lists for AES-CBC
  crypto: nx - fix limits to sg lists for AES-ECB
  crypto: nx - add offset to nx_build_sg_lists()
  padata - Register hotcpu notifier after initialization
  padata - share code between CPU_ONLINE and CPU_DOWN_FAILED, same to CPU_DOWN_PREPARE and CPU_UP_CANCELED
  hwrng: omap - reorder OMAP TRNG driver code
  crypto: omap-sham - correct dma burst size
  crypto: omap-sham - Enable Polling mode if DMA fails
  crypto: tegra-aes - bitwise vs logical and
  crypto: sahara - checking the wrong variable
  ...

Pull networking fixes from David Miller:
 "A quick set of fixes, some to deal with fallout from yesterday's
  net-next merge.

   1) Fix compilation of bnx2x driver with CONFIG_BNX2X_SRIOV disabled,
      from Dmitry Kravkov.

   2) Fix a bnx2x regression caused by one of Dave Jones's mistaken
      braces changes, from Eilon Greenstein.

   3) Add some protective filtering in the netlink tap code, from Daniel
      Borkmann.

   4) Fix TCP congestion window growth regression after timeouts, from
      Yuchung Cheng.

   5) Correctly adjust TCP's rcv_ssthresh for out of order packets, from
      Eric Dumazet"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  tcp: properly increase rcv_ssthresh for ofo packets
  net: add documentation for BQL helpers
  mlx5: remove unused MLX5_DEBUG param in Kconfig
  bnx2x: Restore a call to config_init
  bnx2x: fix broken compilation with CONFIG_BNX2X_SRIOV is not set
  tcp: fix no cwnd growth after timeout
  net: netlink: filter particular protocols from analyzers

NFSv4 security auto-negotiation has been broken since
commit 4580a92d (NFS:
Use server-recommended security flavor by default (NFSv3))
because nfs4_try_mount() will automatically select AUTH_SYS
if it sees no auth flavours.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>