Pull Ceph updates from Sage Weil:
 "The two main changes are aio support in CephFS, and a series that
  fixes several issues in the authentication key timeout/renewal code.

  On top of that are a variety of cleanups and minor bug fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  libceph: remove outdated comment
  libceph: kill off ceph_x_ticket_handler::validity
  libceph: invalidate AUTH in addition to a service ticket
  libceph: fix authorizer invalidation, take 2
  libceph: clear messenger auth_retry flag if we fault
  libceph: fix ceph_msg_revoke()
  libceph: use list_for_each_entry_safe
  ceph: use i_size_{read,write} to get/set i_size
  ceph: re-send AIO write request when getting -EOLDSNAP error
  ceph: Asynchronous IO support
  ceph: Avoid to propagate the invalid page point
  ceph: fix double page_unlock() in page_mkwrite()
  rbd: delete an unnecessary check before rbd_dev_destroy()
  libceph: use list_next_entry instead of list_entry_next
  ceph: ceph_frag_contains_value can be boolean
  ceph: remove unused functions in ceph_frag.h

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cap message from MDS can update i_size. In that case, we don't
hold i_mutex. So it's unsafe to directly access inode->i_size
while holding i_mutex.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

When receiving -EOLDSNAP from OSD, we need to re-send corresponding
write request. Due to locking issue, we can send new request inside
another OSD request's complete callback. So we use worker to re-send
request for AIO write.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

The basic idea of AIO support is simple, just call kiocb::ki_complete()
in OSD request's complete callback. But there are several special cases.

when IO span multiple objects, we need to wait until all OSD requests
are complete, then call kiocb::ki_complete(). Error handling in this case
is tricky too. For simplify, AIO both span multiple objects and extends
i_size are not allowed.

Another special case is check EOF for reading (other client can write to
the file and extend i_size concurrently). For simplify, the direct-IO/AIO
code path does do the check, fallback to normal syn read instead.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

The variant pagep will still get the invalid page point, although ceph
fails in function ceph_update_writeable_page.

To fix this issue, Assigne the page to pagep until there is no failure
in function ceph_update_writeable_page.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Signed-off-by: Yan, Zheng <zyan@redhat.com>

ceph_update_writeable_page() unlocks the page on errors, so
page_mkwrite() should not unlock the page again.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable->full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull vfs xattr updates from Al Viro:
 "Andreas' xattr cleanup series.

  It's a followup to his xattr work that went in last cycle; -0.5KLoC"

* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  xattr handlers: Simplify list operation
  ocfs2: Replace list xattr handler operations
  nfs: Move call to security_inode_listsecurity into nfs_listxattr
  xfs: Change how listxattr generates synthetic attributes
  tmpfs: listxattr should include POSIX ACL xattrs
  tmpfs: Use xattr handler infrastructure
  btrfs: Use xattr handler infrastructure
  vfs: Distinguish between full xattr names and proper prefixes
  posix acls: Remove duplicate xattr name definitions
  gfs2: Remove gfs2_xattr_acl_chmod
  vfs: Remove vfs_xattr_cmp

new method: ->get_link(); replacement of ->follow_link().  The differences
are:
	* inode and dentry are passed separately
	* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
	* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.

It's a flagday change - the old method is gone, all in-tree instances
converted.  Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode.  That'll change
in the next commits.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>