There is no point in flooding logs with warnings or especially crashing
the system if we fail to create a cache for a memcg.  In this case we
will be accounting the memcg allocation to the root cgroup until we
succeed to create its own cache, but it isn't that critical.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kmem_cache_dup() is only called from memcg_create_kmem_cache().  The
latter, in fact, does nothing besides this, so let's fold
kmem_cache_dup() into memcg_create_kmem_cache().

This patch also makes the memcg_cache_mutex private to
memcg_create_kmem_cache(), because it is not used anywhere else.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We obtain a per-memcg cache from a root kmem_cache by dereferencing an
entry of the root cache's memcg_params::memcg_caches array.  If we find
no cache for a memcg there on allocation, we initiate the memcg cache
creation (see memcg_kmem_get_cache()).  The cache creation proceeds
asynchronously in memcg_create_kmem_cache() in order to avoid lock
clashes, so there can be several threads trying to create the same
kmem_cache concurrently, but only one of them may succeed.  However, due
to a race in the code, it is not always true.  The point is that the
memcg_caches array can be relocated when we activate kmem accounting for
a memcg (see memcg_update_all_caches(), memcg_update_cache_size()).  If
memcg_update_cache_size() and memcg_create_kmem_cache() proceed
concurrently as described below, we can leak a kmem_cache.

Asume two threads schedule creation of the same kmem_cache.  One of them
successfully creates it.  Another one should fail then, but if
memcg_create_kmem_cache() interleaves with memcg_update_cache_size() as
follows, it won't:

  memcg_create_kmem_cache()             memcg_update_cache_size()
  (called w/o mutexes held)             (called with slab_mutex,
                                         set_limit_mutex held)
  -------------------------             -------------------------

  mutex_lock(&memcg_cache_mutex)

                                        s->memcg_params=kzalloc(...)

  new_cachep=cache_from_memcg_idx(cachep,idx)
  // new_cachep==NULL => proceed to creation

                                        s->memcg_params->memcg_caches[i]
                                            =cur_params->memcg_caches[i]

  // kmem_cache_create_memcg takes slab_mutex
  // so we will hang around until
  // memcg_update_cache_size finishes, but
  // nothing will prevent it from succeeding so
  // memcg_caches[idx] will be overwritten in
  // memcg_register_cache!

  new_cachep = kmem_cache_create_memcg(...)
  mutex_unlock(&memcg_cache_mutex)

Let's fix this by moving the check for existence of the memcg cache to
kmem_cache_create_memcg() to be called under the slab_mutex and make it
return NULL if so.

A similar race is possible when destroying a memcg cache (see
kmem_cache_destroy()).  Since memcg_unregister_cache(), which clears the
pointer in the memcg_caches array, is called w/o protection, we can race
with memcg_update_cache_size() and omit clearing the pointer.  Therefore
memcg_unregister_cache() should be moved before we release the
slab_mutex.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All caches of the same memory cgroup are linked in the memcg_slab_caches
list via kmem_cache::memcg_params::list.  This list is traversed, for
example, when we read memory.kmem.slabinfo.

Since the list actually consists of memcg_cache_params objects, we have
to convert an element of the list to a kmem_cache object using
memcg_params_to_cache(), which obtains the pointer to the cache from the
memcg_params::memcg_caches array of the corresponding root cache.  That
said the pointer to a kmem_cache in its parent's memcg_params must be
initialized before adding the cache to the list, and cleared only after
it has been unlinked.  Currently it is vice-versa, which can result in a
NULL ptr dereference while traversing the memcg_slab_caches list.  This
patch restores the correct order.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Each root kmem_cache has pointers to per-memcg caches stored in its
memcg_params::memcg_caches array.  Whenever we want to allocate a slab
for a memcg, we access this array to get per-memcg cache to allocate
from (see memcg_kmem_get_cache()).  The access must be lock-free for
performance reasons, so we should use barriers to assert the kmem_cache
is up-to-date.

First, we should place a write barrier immediately before setting the
pointer to it in the memcg_caches array in order to make sure nobody
will see a partially initialized object.  Second, we should issue a read
barrier before dereferencing the pointer to conform to the write
barrier.

However, currently the barrier usage looks rather strange.  We have a
write barrier *after* setting the pointer and a read barrier *before*
reading the pointer, which is incorrect.  This patch fixes this.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, we have rather a messy function set relating to per-memcg
kmem cache initialization/destruction.

Per-memcg caches are created in memcg_create_kmem_cache().  This
function calls kmem_cache_create_memcg() to allocate and initialize a
kmem cache and then "registers" the new cache in the
memcg_params::memcg_caches array of the parent cache.

During its work-flow, kmem_cache_create_memcg() executes the following
memcg-related functions:

 - memcg_alloc_cache_params(), to initialize memcg_params of the newly
   created cache;
 - memcg_cache_list_add(), to add the new cache to the memcg_slab_caches
   list.

On the other hand, kmem_cache_destroy() called on a cache destruction
only calls memcg_release_cache(), which does all the work: it cleans the
reference to the cache in its parent's memcg_params::memcg_caches,
removes the cache from the memcg_slab_caches list, and frees
memcg_params.

Such an inconsistency between destruction and initialization paths make
the code difficult to read, so let's clean this up a bit.

This patch moves all the code relating to registration of per-memcg
caches (adding to memcg list, setting the pointer to a cache from its
parent) to the newly created memcg_register_cache() and
memcg_unregister_cache() functions making the initialization and
destruction paths look symmetrical.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We do not free the cache's memcg_params if __kmem_cache_create fails.
Fix this.

Plus, rename memcg_register_cache() to memcg_alloc_cache_params(),
because it actually does not register the cache anywhere, but simply
initialize kmem_cache::memcg_params.

[akpm@linux-foundation.org: fix build]
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently kmem_cache_create_memcg() backoffs on failure inside
conditionals, without using gotos.  This results in the rollback code
duplication, which makes the function look cumbersome even though on
error we should only free the allocated cache.  Since in the next patch
I am going to add yet another rollback function call on error path
there, let's employ labels instead of conditionals for undoing any
changes on failure to keep things clean.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Reviewed-by: NPekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Most of the VM_BUG_ON assertions are performed on a page.  Usually, when
one of these assertions fails we'll get a BUG_ON with a call stack and
the registers.

I've recently noticed based on the requests to add a small piece of code
that dumps the page to various VM_BUG_ON sites that the page dump is
quite useful to people debugging issues in mm.

This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what
VM_BUG_ON() does, also dumps the page before executing the actual
BUG_ON.

[akpm@linux-foundation.org: fix up includes]
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

stable_page_flags() checks !PageHuge && PageTransCompound && PageLRU to
know that a specified page is thp or not.  But sometimes it's not enough
and we fail to detect thp when the thp is on pagevec.  This happens only
for a few seconds after LRU list operations, but it makes it difficult
to control our applications depending on this flag.

So this patch adds another check PageAnon to detect thps on pagevec.  It
might not give the future extensibility for thp pagecache, but it's OK
at least for now.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The vmalloc was introduced by 33327948 ("memcgroup: use vmalloc for
mem_cgroup allocation"), because at that time MAX_NUMNODES was used for
defining the per-node array in the mem_cgroup structure so that the
structure could be huge even if the system had the only NUMA node.

The situation was significantly improved by commit 45cf7ebd ("memcg:
reduce the size of struct memcg 244-fold"), which made the size of the
mem_cgroup structure calculated dynamically depending on the real number
of NUMA nodes installed on the system (nr_node_ids), so now there is no
point in using vmalloc here: the structure is allocated rarely and on
most systems its size is about 1K.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit ff6a6da6 ("mm: accelerate munlock() treatment of THP
pages") munlock skips tail pages of a munlocked THP page.  There is some
attempt to prevent bad consequences of racing with a THP page split, but
code inspection indicates that there are two problems that may lead to a
non-fatal, yet wrong outcome.

First, __split_huge_page_refcount() copies flags including PageMlocked
from the head page to the tail pages.  Clearing PageMlocked by
munlock_vma_page() in the middle of this operation might result in part
of tail pages left with PageMlocked flag.  As the head page still
appears to be a THP page until all tail pages are processed,
munlock_vma_page() might think it munlocked the whole THP page and skip
all the former tail pages.  Before ff6a6da6, those pages would be
cleared in further iterations of munlock_vma_pages_range(), but NR_MLOCK
would still become undercounted (related the next point).

Second, NR_MLOCK accounting is based on call to hpage_nr_pages() after
the PageMlocked is cleared.  The accounting might also become
inconsistent due to race with __split_huge_page_refcount()

- undercount when HUGE_PMD_NR is subtracted, but some tail pages are
  left with PageMlocked set and counted again (only possible before
  ff6a6da6)

- overcount when hpage_nr_pages() sees a normal page (split has already
  finished), but the parallel split has meanwhile cleared PageMlocked from
  additional tail pages

This patch prevents both problems via extending the scope of lru_lock in
munlock_vma_page().  This is convenient because:

- __split_huge_page_refcount() takes lru_lock for its whole operation

- munlock_vma_page() typically takes lru_lock anyway for page isolation

As this becomes a second function where page isolation is done with
lru_lock already held, factor this out to a new
__munlock_isolate_lru_page() function and clean up the code around.

[akpm@linux-foundation.org: avoid a coding-style ugly]
Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bad_page() is cool in that it prints out a bunch of data about the page.
But, I can never remember which page flags are good and which are bad,
or whether ->index or ->mapping is required to be NULL.

This patch allows bad/dump_page() callers to specify a string about why
they are dumping the page and adds explanation strings to a number of
places.  It also adds a 'bad_flags' argument to bad_page(), which it
then dumps out separately from the flags which are actually set.

This way, the messages will show specifically why the page was bad,
*specifically* which flags it is complaining about, if it was a page
flag combination which was the problem.

[akpm@linux-foundation.org: switch to pr_alert]
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: NChristoph Lameter <cl@linux.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "compressor" and "enabled" params are currently hidden, this changes
them to read-only, so userspace can tell if zswap is enabled or not and
see what compressor is in use.
Signed-off-by: NDan Streetman <ddstreet@ieee.org>
Cc: Vladimir Murzin <murzin.v@gmail.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Weijie Yang <weijie.yang@samsung.com>
Acked-by: NSeth Jennings <sjennings@variantweb.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/vm/locking is a blast from the past.  In the entire git
history, it has had precisely Three modifications.  Two of those look to
be pure renames, and the third was from 2005.

The doc contains such gems as:

> The page_table_lock is grabbed while holding the
> kernel_lock spinning monitor.

> Page stealers hold kernel_lock to protect against a bunch of
> races.

Or this which talks about mmap_sem:

> 4. The exception to this rule is expand_stack, which just
>    takes the read lock and the page_table_lock, this is ok
>    because it doesn't really modify fields anybody relies on.

expand_stack() doesn't take any locks any more directly, and the
mmap_sem acquisition was long ago moved up in to the page fault code
itself.

It could be argued that we need to rewrite this, but it is dangerous to
leave it as-is.  It will confuse more people than it helps.
Signed-off-by: NDave Hansen <dave.hansen@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sort the exception table at build-time rather than during boot.

Microblaze is the same case as AARCH64 that's why EM_MICROBLAZE
conditional check was added to allow cross-compilation on machines which
are not running the latest libc-dev.

Inspired by AARCH64 commit adace895 ("arm64: extable: sort the
exception table at build time").
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Acked-by: NDavid Daney <david.daney@cavium.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

  drivers/staging/comedi/drivers/das6402.c: In function 'intr_handler':
  drivers/staging/comedi/drivers/das6402.c:164:3: error: implicit declaration of function 'outw_p' [-Werror=implicit-function-declaration]
  drivers/staging/speakup/speakup_dtlk.c: In function 'synth_probe':
  drivers/staging/speakup/speakup_dtlk.c:362:2: error: implicit declaration of function 'inw_p' [-Werror=implicit-function-declaration]
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull UDF & jbd fixes from Jan Kara:
 "A cleanup of JBD log messages and UDF fix of a lockdep warning"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: Fix lockdep warning from udf_symlink()
  jbd: Revise KERN_EMERG error messages

The associative array code creates unnecessary and potentially
problematic global variable 'status'.  Remove it since never used.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull fuse update from Miklos Szeredi:
 "This contains a fix for a potential use-after-module-unload bug
  noticed by Al and caching improvements for read-only fuse filesystems
  by Andrew Gallagher"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: support clients that don't implement 'open'
  fuse: don't invalidate attrs when not using atime
  fuse: fix SetPageUptodate() condition in STORE
  fuse: fix pipe_buf_operations

Pull f2fs updates from Jaegeuk Kim:
 "In this round, a couple of sysfs entries were introduced to tune the
  f2fs at runtime.

  In addition, f2fs starts to support inline_data and improves the
  read/write performance in some workloads by refactoring bio-related
  flows.

  This patch-set includes the following major enhancement patches.
   - support inline_data
   - refactor bio operations such as merge operations and rw type
     assignment
   - enhance the direct IO path
   - enhance bio operations
   - truncate a node page when it becomes obsolete
   - add sysfs entries: small_discards, max_victim_search, and
     in-place-update
   - add a sysfs entry to control max_victim_search

  The other bug fixes are as follows.
   - fix a bug in truncate_partial_nodes
   - avoid warnings during sparse and build process
   - fix error handling flows
   - fix potential bit overflows

  And, there are a bunch of cleanups"

* tag 'for-f2fs-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (95 commits)
  f2fs: drop obsolete node page when it is truncated
  f2fs: introduce NODE_MAPPING for code consistency
  f2fs: remove the orphan block page array
  f2fs: add help function META_MAPPING
  f2fs: move a branch for code redability
  f2fs: call mark_inode_dirty to flush dirty pages
  f2fs: clean checkpatch warnings
  f2fs: missing REQ_META and REQ_PRIO when sync_meta_pages(META_FLUSH)
  f2fs: avoid f2fs_balance_fs call during pageout
  f2fs: add delimiter to seperate name and value in debug phrase
  f2fs: use spinlock rather than mutex for better speed
  f2fs: move alloc new orphan node out of lock protection region
  f2fs: move grabing orphan pages out of protection region
  f2fs: remove the needless parameter of f2fs_wait_on_page_writeback
  f2fs: update documents and a MAINTAINERS entry
  f2fs: add a sysfs entry to control max_victim_search
  f2fs: improve write performance under frequent fsync calls
  f2fs: avoid to read inline data except first page
  f2fs: avoid to left uninitialized data in page when read inline data
  f2fs: fix truncate_partial_nodes bug
  ...

Pull xfs update from Ben Myers:
 "This is primarily bug fixes, many of which you already have.  New
  stuff includes a series to decouple the in-memory and on-disk log
  format, helpers in the area of inode clusters, and i_version handling.

  We decided to try to use more topic branches this release, so there
  are some merge commits in there on account of that.  I'm afraid I
  didn't do a good job of putting meaningful comments in the first
  couple of merges.  Sorry about that.  I think I have the hang of it
  now.

  For 3.14-rc1 there are fixes in the areas of remote attributes,
  discard, growfs, memory leaks in recovery, directory v2, quotas, the
  MAINTAINERS file, allocation alignment, extent list locking, and in
  xfs_bmapi_allocate.  There are cleanups in xfs_setsize_buftarg,
  removing unused macros, quotas, setattr, and freeing of inode
  clusters.  The in-memory and on-disk log format have been decoupled, a
  common helper to calculate the number of blocks in an inode cluster
  has been added, and handling of i_version has been pulled into the
  filesystems that use it.

   - cleanup in xfs_setsize_buftarg
   - removal of remaining unused flags for vop toss/flush/flushinval
   - fix for memory corruption in xfs_attrlist_by_handle
   - fix for out-of-date comment in xfs_trans_dqlockedjoin
   - fix for discard if range length is less than one block
   - fix for overrun of agfl buffer using growfs on v4 superblock
     filesystems
   - pull i_version handling out into the filesystems that use it
   - don't leak recovery items on error
   - fix for memory leak in xfs_dir2_node_removename
   - several cleanups for quotas
   - fix bad assertion in xfs_qm_vop_create_dqattach
   - cleanup for xfs_setattr_mode, and add xfs_setattr_time
   - fix quota assert in xfs_setattr_nonsize
   - fix an infinite loop when turning off group/project quota before
     user quota
   - fix for temporary buffer allocation failure in xfs_dir2_block_to_sf
     with large directory block sizes
   - fix Dave's email address in MAINTAINERS
   - cleanup calculation of freed inode cluster blocks
   - fix alignment of initial file allocations to match filesystem
     geometry
   - decouple in-memory and on-disk log format
   - introduce a common helper to calculate the number of filesystem
     blocks in an inode cluster
   - fixes for extent list locking
   - fix for off-by-one in xfs_attr3_rmt_verify
   - fix for missing destroy_work_on_stack in xfs_bmapi_allocate"

* tag 'xfs-for-linus-v3.14-rc1' of git://oss.sgi.com/xfs/xfs: (51 commits)
  xfs: Calling destroy_work_on_stack() to pair with INIT_WORK_ONSTACK()
  xfs: fix off-by-one error in xfs_attr3_rmt_verify
  xfs: assert that we hold the ilock for extent map access
  xfs: use xfs_ilock_attr_map_shared in xfs_attr_list_int
  xfs: use xfs_ilock_attr_map_shared in xfs_attr_get
  xfs: use xfs_ilock_data_map_shared in xfs_qm_dqiterate
  xfs: use xfs_ilock_data_map_shared in xfs_qm_dqtobp
  xfs: take the ilock around xfs_bmapi_read in xfs_zero_remaining_bytes
  xfs: reinstate the ilock in xfs_readdir
  xfs: add xfs_ilock_attr_map_shared
  xfs: rename xfs_ilock_map_shared
  xfs: remove xfs_iunlock_map_shared
  xfs: no need to lock the inode in xfs_find_handle
  xfs: use xfs_icluster_size_fsb in xfs_imap
  xfs: use xfs_icluster_size_fsb in xfs_ifree_cluster
  xfs: use xfs_icluster_size_fsb in xfs_ialloc_inode_init
  xfs: use xfs_icluster_size_fsb in xfs_bulkstat
  xfs: introduce a common helper xfs_icluster_size_fsb
  xfs: get rid of XFS_IALLOC_BLOCKS macros
  xfs: get rid of XFS_INODE_CLUSTER_SIZE macros
  ...

Pull module updates from Rusty Russell.

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  module: Add missing newline in printk call.
  module: fix coding style
  export: declare ksymtab symbols
  module.h: Remove unnecessary semicolon
  params: improve standard definitions
  Add Documentation/module-signing.txt file

Pull virtio update from Rusty Russell:
 "A few simple fixes.  Quiet cycle"

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  drivers: virtio: Mark function virtballoon_migratepage() as static in virtio_balloon.c
  virtio-scsi: Fix hotcpu_notifier use-after-free with virtscsi_freeze
  virtio: pci: remove unnecessary pci_set_drvdata()

Pull Xen updates from Konrad Rzeszutek Wilk:
 "Two major features that Xen community is excited about:

  The first is event channel scalability by David Vrabel - we switch
  over from an two-level per-cpu bitmap of events (IRQs) - to an FIFO
  queue with priorities.  This lets us be able to handle more events,
  have lower latency, and better scalability.  Good stuff.

  The other is PVH by Mukesh Rathor.  In short, PV is a mode where the
  kernel lets the hypervisor program page-tables, segments, etc.  With
  EPT/NPT capabilities in current processors, the overhead of doing this
  in an HVM (Hardware Virtual Machine) container is much lower than the
  hypervisor doing it for us.

  In short we let a PV guest run without doing page-table, segment,
  syscall, etc updates through the hypervisor - instead it is all done
  within the guest container.  It is a "hybrid" PV - hence the 'PVH'
  name - a PV guest within an HVM container.

  The major benefits are less code to deal with - for example we only
  use one function from the the pv_mmu_ops (which has 39 function
  calls); faster performance for syscall (no context switches into the
  hypervisor); less traps on various operations; etc.

  It is still being baked - the ABI is not yet set in stone.  But it is
  pretty awesome and we are excited about it.

  Lastly, there are some changes to ARM code - you should get a simple
  conflict which has been resolved in #linux-next.

  In short, this pull has awesome features.

  Features:
   - FIFO event channels.  Key advantages: support for over 100,000
     events (2^17), 16 different event priorities, improved fairness in
     event latency through the use of FIFOs.
   - Xen PVH support.  "It’s a fully PV kernel mode, running with
     paravirtualized disk and network, paravirtualized interrupts and
     timers, no emulated devices of any kind (and thus no qemu), no BIOS
     or legacy boot — but instead of requiring PV MMU, it uses the HVM
     hardware extensions to virtualize the pagetables, as well as system
     calls and other privileged operations." (from "The
     Paravirtualization Spectrum, Part 2: From poles to a spectrum")

  Bug-fixes:
   - Fixes in balloon driver (refactor and make it work under ARM)
   - Allow xenfb to be used in HVM guests.
   - Allow xen_platform_pci=0 to work properly.
   - Refactors in event channels"

* tag 'stable/for-linus-3.14-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (52 commits)
  xen/pvh: Set X86_CR0_WP and others in CR0 (v2)
  MAINTAINERS: add git repository for Xen
  xen/pvh: Use 'depend' instead of 'select'.
  xen: delete new instances of __cpuinit usage
  xen/fb: allow xenfb initialization for hvm guests
  xen/evtchn_fifo: fix error return code in evtchn_fifo_setup()
  xen-platform: fix error return code in platform_pci_init()
  xen/pvh: remove duplicated include from enlighten.c
  xen/pvh: Fix compile issues with xen_pvh_domain()
  xen: Use dev_is_pci() to check whether it is pci device
  xen/grant-table: Force to use v1 of grants.
  xen/pvh: Support ParaVirtualized Hardware extensions (v3).
  xen/pvh: Piggyback on PVHVM XenBus.
  xen/pvh: Piggyback on PVHVM for grant driver (v4)
  xen/grant: Implement an grant frame array struct (v3).
  xen/grant-table: Refactor gnttab_init
  xen/grants: Remove gnttab_max_grant_frames dependency on gnttab_init.
  xen/pvh: Piggyback on PVHVM for event channels (v2)
  xen/pvh: Update E820 to work with PVH (v2)
  xen/pvh: Secondary VCPU bringup (non-bootup CPUs)
  ...

Pull KVM updates from Paolo Bonzini:
 "First round of KVM updates for 3.14; PPC parts will come next week.

  Nothing major here, just bugfixes all over the place.  The most
  interesting part is the ARM guys' virtualized interrupt controller
  overhaul, which lets userspace get/set the state and thus enables
  migration of ARM VMs"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (67 commits)
  kvm: make KVM_MMU_AUDIT help text more readable
  KVM: s390: Fix memory access error detection
  KVM: nVMX: Update guest activity state field on L2 exits
  KVM: nVMX: Fix nested_run_pending on activity state HLT
  KVM: nVMX: Clean up handling of VMX-related MSRs
  KVM: nVMX: Add tracepoints for nested_vmexit and nested_vmexit_inject
  KVM: nVMX: Pass vmexit parameters to nested_vmx_vmexit
  KVM: nVMX: Leave VMX mode on clearing of feature control MSR
  KVM: VMX: Fix DR6 update on #DB exception
  KVM: SVM: Fix reading of DR6
  KVM: x86: Sync DR7 on KVM_SET_DEBUGREGS
  add support for Hyper-V reference time counter
  KVM: remove useless write to vcpu->hv_clock.tsc_timestamp
  KVM: x86: fix tsc catchup issue with tsc scaling
  KVM: x86: limit PIT timer frequency
  KVM: x86: handle invalid root_hpa everywhere
  kvm: Provide kvm_vcpu_eligible_for_directed_yield() stub
  kvm: vfio: silence GCC warning
  KVM: ARM: Remove duplicate include
  arm/arm64: KVM: relax the requirements of VMA alignment for THP
  ...

Pull trivial tree updates from Jiri Kosina:
 "Usual rocket science stuff from trivial.git"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  neighbour.h: fix comment
  sched: Fix warning on make htmldocs caused by wait.h
  slab: struct kmem_cache is protected by slab_mutex
  doc: Fix typo in USB Gadget Documentation
  of/Kconfig: Spelling s/one/once/
  mkregtable: Fix sscanf handling
  lp5523, lp8501: comment improvements
  thermal: rcar: comment spelling
  treewide: fix comments and printk msgs
  IXP4xx: remove '1 &&' from a condition check in ixp4xx_restart()
  Documentation: update /proc/uptime field description
  Documentation: Fix size parameter for snprintf
  arm: fix comment header and macro name
  asm-generic: uaccess: Spelling s/a ny/any/
  mtd: onenand: fix comment header
  doc: driver-model/platform.txt: fix a typo
  drivers: fix typo in DEVTMPFS_MOUNT Kconfig help text
  doc: Fix typo (acces_process_vm -> access_process_vm)
  treewide: Fix typos in printk
  drivers/gpu/drm/qxl/Kconfig: reformat the help text
  ...

Pull HID updates from Jiri Kosina:

 - quite some work on hid-sony driver in order to have DualShock 4
   device properly supported, from Frank Praznik

 - fixed support for suspending I2C conntected devices, from Mika
   Westerberg

 - regression fix for 0xff05 usage on Microsoft Ergonomy, from Jiri
   Kosina

 - support for Synaptics HD touchscreen, from AceLan Kao

 - workaround for USB 3.0 problem for logitech-dj connected devices,
   from Benjamin Tisssoires

 - support for Logitech Dual Action pads, from Vitaly Katraew

 - quite a few other assorted fixes and device ID additions

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (33 commits)
  HID: sony: Use colors for the Dualshock 4 LED names
  HID: sony: Add annotated HID descriptor for the Dualshock 4
  HID: sony: Cache the output report for the Dualshock 4
  HID: sony: Map gyroscopes and accelerometers to axes
  HID: sony: Fix spacing in the device definitions.
  HID: sony: Use standard output reports instead of raw reports to send data to the Dualshock 4.
  HID: sony: Use separate identifiers for USB and Bluetooth connected Dualshock 4 controllers.
  HID: hid-holtek-mouse: add new a070 mouse
  HID: hid-sensor-hub: Fix buggy report descriptors
  HID: logitech-dj: Fix USB 3.0 issue
  HID: sony: Rename worker function
  HID: sony: Add LED controls for the Dualshock 4
  HID: sony: Add force-feedback support for the Dualshock 4
  HID: hidraw: make comment more accurate and nicer
  HID: sony: fix error return code
  HID: input: fix input sysfs path for hid devices
  HID: debug: add labels for some new buttons
  HID: remove SIS entries from hid_have_special_driver[]
  HID: microsoft: no fallthrough in MS ergonomy 0xff05 usage
  HID: add support for SiS multitouch panel in the touch monitor LG 23ET83V
  ...

Pull device-mapper changes from Mike Snitzer:
 "A lot of attention was paid to improving the thin-provisioning
  target's handling of metadata operation failures and running out of
  space.  A new 'error_if_no_space' feature was added to allow users to
  error IOs rather than queue them when either the data or metadata
  space is exhausted.

  Additional fixes/features include:
   - a few fixes to properly support thin metadata device resizing
   - a solution for reliably waiting for a DM device's embedded kobject
     to be released before destroying the device
   - old dm-snapshot is updated to use the dm-bufio interface to take
     advantage of readahead capabilities that improve snapshot
     activation
   - new dm-cache target tunables to control how quickly data is
     promoted to the cache (fast) device
   - improved write efficiency of cluster mirror target by combining
     userspace flush and mark requests"

* tag 'dm-3.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (35 commits)
  dm log userspace: allow mark requests to piggyback on flush requests
  dm space map metadata: fix bug in resizing of thin metadata
  dm cache: add policy name to status output
  dm thin: fix pool feature parsing
  dm sysfs: fix a module unload race
  dm snapshot: use dm-bufio prefetch
  dm snapshot: use dm-bufio
  dm snapshot: prepare for switch to using dm-bufio
  dm snapshot: use GFP_KERNEL when initializing exceptions
  dm cache: add block sizes and total cache blocks to status output
  dm btree: add dm_btree_find_lowest_key
  dm space map metadata: fix extending the space map
  dm space map common: make sure new space is used during extend
  dm: wait until embedded kobject is released before destroying a device
  dm: remove pointless kobject comparison in dm_get_from_kobject
  dm snapshot: call destroy_work_on_stack() to pair with INIT_WORK_ONSTACK()
  dm cache policy mq: introduce three promotion threshold tunables
  dm cache policy mq: use list_del_init instead of list_del + INIT_LIST_HEAD
  dm thin: fix set_pool_mode exposed pool operation races
  dm thin: eliminate the no_free_space flag
  ...

Pull SCSI updates from James Bottomley:
 "This patch set is a lot of driver updates for qla4xxx, bfa, hpsa,
  qla2xxx.  It also removes the aic7xxx_old driver (which has been
  deprecated for nearly a decade) and adds support for deadlines in
  error handling"

* tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (75 commits)
  [SCSI] hpsa: allow SCSI mid layer to handle unit attention
  [SCSI] hpsa: do not require board "not ready" status after hard reset
  [SCSI] hpsa: enable unit attention reporting
  [SCSI] hpsa: rename scsi prefetch field
  [SCSI] hpsa: use workqueue instead of kernel thread for lockup detection
  [SCSI] ipr: increase dump size in ipr driver
  [SCSI] mac_scsi: Fix crash on out of memory
  [SCSI] st: fix enlarge_buffer
  [SCSI] qla1280: Annotate timer on stack so object debug does not complain
  [SCSI] qla4xxx: Update driver version to 5.04.00-k3
  [SCSI] qla4xxx: Recreate chap data list during get chap operation
  [SCSI] qla4xxx: Add support for ISCSI_PARAM_LOCAL_IPADDR sysfs attr
  [SCSI] libiscsi: Add local_ipaddr parameter in iscsi_conn struct
  [SCSI] scsi_transport_iscsi: Export ISCSI_PARAM_LOCAL_IPADDR attr for iscsi_connection
  [SCSI] qla4xxx: Add host statistics support
  [SCSI] scsi_transport_iscsi: Add host statistics support
  [SCSI] qla4xxx: Added support for Diagnostics MBOX command
  [SCSI] bfa: Driver version upgrade to 3.2.23.0
  [SCSI] bfa: change FC_ELS_TOV to 20sec
  [SCSI] bfa: Observed auto D-port mode instead of manual
  ...

Pull PCI updates from Bjorn Helgaas:
 "PCI changes for the v3.14 merge window:

  Resource management
    - Change pci_bus_region addresses to dma_addr_t (Bjorn Helgaas)
    - Support 64-bit AGP BARs (Bjorn Helgaas, Yinghai Lu)
    - Add pci_bus_address() to get bus address of a BAR (Bjorn Helgaas)
    - Use pci_resource_start() for CPU address of AGP BARs (Bjorn Helgaas)
    - Enforce bus address limits in resource allocation (Yinghai Lu)
    - Allocate 64-bit BARs above 4G when possible (Yinghai Lu)
    - Convert pcibios_resource_to_bus() to take pci_bus, not pci_dev (Yinghai Lu)

  PCI device hotplug
    - Major rescan/remove locking update (Rafael J. Wysocki)
    - Make ioapic builtin only (not modular) (Yinghai Lu)
    - Fix release/free issues (Yinghai Lu)
    - Clean up pciehp (Bjorn Helgaas)
    - Announce pciehp slot info during enumeration (Bjorn Helgaas)

  MSI
    - Add pci_msi_vec_count(), pci_msix_vec_count() (Alexander Gordeev)
    - Add pci_enable_msi_range(), pci_enable_msix_range() (Alexander Gordeev)
    - Deprecate "tri-state" interfaces: fail/success/fail+info (Alexander Gordeev)
    - Export MSI mode using attributes, not kobjects (Greg Kroah-Hartman)
    - Drop "irq" param from *_restore_msi_irqs() (DuanZhenzhong)

  SR-IOV
    - Clear NumVFs when disabling SR-IOV in sriov_init() (ethan.zhao)

  Virtualization
    - Add support for save/restore of extended capabilities (Alex Williamson)
    - Add Virtual Channel to save/restore support (Alex Williamson)
    - Never treat a VF as a multifunction device (Alex Williamson)
    - Add pci_try_reset_function(), et al (Alex Williamson)

  AER
    - Ignore non-PCIe error sources (Betty Dall)
    - Support ACPI HEST error sources for domains other than 0 (Betty Dall)
    - Consolidate HEST error source parsers (Bjorn Helgaas)
    - Add a TLP header print helper (Borislav Petkov)

  Freescale i.MX6
    - Remove unnecessary code (Fabio Estevam)
    - Make reset-gpio optional (Marek Vasut)
    - Report "link up" only after link training completes (Marek Vasut)
    - Start link in Gen1 before negotiating for Gen2 mode (Marek Vasut)
    - Fix PCIe startup code (Richard Zhu)

  Marvell MVEBU
    - Remove duplicate of_clk_get_by_name() call (Andrew Lunn)
    - Drop writes to bridge Secondary Status register (Jason Gunthorpe)
    - Obey bridge PCI_COMMAND_MEM and PCI_COMMAND_IO bits (Jason Gunthorpe)
    - Support a bridge with no IO port window (Jason Gunthorpe)
    - Use max_t() instead of max(resource_size_t,) (Jingoo Han)
    - Remove redundant of_match_ptr (Sachin Kamat)
    - Call pci_ioremap_io() at startup instead of dynamically (Thomas Petazzoni)

  NVIDIA Tegra
    - Disable Gen2 for Tegra20 and Tegra30 (Eric Brower)

  Renesas R-Car
    - Add runtime PM support (Valentine Barshak)
    - Fix rcar_pci_probe() return value check (Wei Yongjun)

  Synopsys DesignWare
    - Fix crash in dw_msi_teardown_irq() (Bjørn Erik Nilsen)
    - Remove redundant call to pci_write_config_word() (Bjørn Erik Nilsen)
    - Fix missing MSI IRQs (Harro Haan)
    - Add dw_pcie prefix before cfg_read/write (Pratyush Anand)
    - Fix I/O transfers by using CPU (not realio) address (Pratyush Anand)
    - Whitespace cleanup (Jingoo Han)

  EISA
    - Call put_device() if device_register() fails (Levente Kurusa)
    - Revert EISA initialization breakage ((Bjorn Helgaas)

  Miscellaneous
    - Remove unused code, including PCIe 3.0 interfaces (Stephen Hemminger)
    - Prevent bus conflicts while checking for bridge apertures (Bjorn Helgaas)
    - Stop clearing bridge Secondary Status when setting up I/O aperture (Bjorn Helgaas)
    - Use dev_is_pci() to identify PCI devices (Yijing Wang)
    - Deprecate DEFINE_PCI_DEVICE_TABLE (Joe Perches)
    - Update documentation 00-INDEX (Erik Ekman)"

* tag 'pci-v3.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (119 commits)
  Revert "EISA: Initialize device before its resources"
  Revert "EISA: Log device resources in dmesg"
  vfio-pci: Use pci "try" reset interface
  PCI: Check parent kobject in pci_destroy_dev()
  xen/pcifront: Use global PCI rescan-remove locking
  powerpc/eeh: Use global PCI rescan-remove locking
  PCI: Fix pci_check_and_unmask_intx() comment typos
  PCI: Add pci_try_reset_function(), pci_try_reset_slot(), pci_try_reset_bus()
  MPT / PCI: Use pci_stop_and_remove_bus_device_locked()
  platform / x86: Use global PCI rescan-remove locking
  PCI: hotplug: Use global PCI rescan-remove locking
  pcmcia: Use global PCI rescan-remove locking
  ACPI / hotplug / PCI: Use global PCI rescan-remove locking
  ACPI / PCI: Use global PCI rescan-remove locking in PCI root hotplug
  PCI: Add global pci_lock_rescan_remove()
  PCI: Cleanup pci.h whitespace
  PCI: Reorder so actual code comes before stubs
  PCI/AER: Support ACPI HEST AER error sources for PCI domains other than 0
  ACPICA: Add helper macros to extract bus/segment numbers from HEST table.
  PCI: Make local functions static
  ...

Pull tracing updates from Steven Rostedt:
 "This pull request has a new feature to ftrace, namely the trace event
  triggers by Tom Zanussi.  A trigger is a way to enable an action when
  an event is hit.  The actions are:

   o  trace on/off - enable or disable tracing
   o  snapshot     - save the current trace buffer in the snapshot
   o  stacktrace   - dump the current stack trace to the ringbuffer
   o  enable/disable events - enable or disable another event

  Namhyung Kim added updates to the tracing uprobes code.  Having the
  uprobes add support for fetch methods.

  The rest are various bug fixes with the new code, and minor ones for
  the old code"

* tag 'trace-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (38 commits)
  tracing: Fix buggered tee(2) on tracing_pipe
  tracing: Have trace buffer point back to trace_array
  ftrace: Fix synchronization location disabling and freeing ftrace_ops
  ftrace: Have function graph only trace based on global_ops filters
  ftrace: Synchronize setting function_trace_op with ftrace_trace_function
  tracing: Show available event triggers when no trigger is set
  tracing: Consolidate event trigger code
  tracing: Fix counter for traceon/off event triggers
  tracing: Remove double-underscore naming in syscall trigger invocations
  tracing/kprobes: Add trace event trigger invocations
  tracing/probes: Fix build break on !CONFIG_KPROBE_EVENT
  tracing/uprobes: Add @+file_offset fetch method
  uprobes: Allocate ->utask before handler_chain() for tracing handlers
  tracing/uprobes: Add support for full argument access methods
  tracing/uprobes: Fetch args before reserving a ring buffer
  tracing/uprobes: Pass 'is_return' to traceprobe_parse_probe_arg()
  tracing/probes: Implement 'memory' fetch method for uprobes
  tracing/probes: Add fetch{,_size} member into deref fetch method
  tracing/probes: Move 'symbol' fetch method to kprobes
  tracing/probes: Implement 'stack' fetch method for uprobes
  ...

If a node page is trucated, we'd better drop the page in the node_inode's page
cache for better memory footprint.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

open/release operations require userspace transitions to keep track
of the open count and to perform any FS-specific setup.  However,
for some purely read-only FSs which don't need to perform any setup
at open/release time, we can avoid the performance overhead of
calling into userspace for open/release calls.

This patch adds the necessary support to the fuse kernel modules to prevent
open/release operations from hitting in userspace. When the client returns
ENOSYS, we avoid sending the subsequent release to userspace, and also
remember this so that future opens also don't trigger a userspace
operation.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

Various read operations (e.g. readlink, readdir) invalidate the cached
attrs for atime changes.  This patch adds a new function
'fuse_invalidate_atime', which checks for a read-only super block and
avoids the attr invalidation in that case.
Signed-off-by: NAndrew Gallagher <andrewjcg@fb.com>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

As noticed by Coverity the "num != 0" condition never triggers.  Instead it
should check for a complete page.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

Having this struct in module memory could Oops when if the module is
unloaded while the buffer still persists in a pipe.

Since sock_pipe_buf_ops is essentially the same as fuse_dev_pipe_buf_steal
merge them into nosteal_pipe_buf_ops (this is the same as
default_pipe_buf_ops except stealing the page from the buffer is not
allowed).
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org

Merge branches 'for-3.13/upstream-fixes', 'for-3.14/i2c-hid', 'for-3.14/sensor-hub', 'for-3.14/sony' and 'for-3.14/upstream' into for-linus

This patch adds NODE_MAPPING which is similar as META_MAPPING introduced by
Gu Zheng.

Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>