Pull vfs updates from Al Viro:

 - more ->d_init() stuff (work.dcache)

 - pathname resolution cleanups (work.namei)

 - a few missing iov_iter primitives - copy_from_iter_full() and
   friends. Either copy the full requested amount, advance the iterator
   and return true, or fail, return false and do _not_ advance the
   iterator. Quite a few open-coded callers converted (and became more
   readable and harder to fuck up that way) (work.iov_iter)

 - several assorted patches, the big one being logfs removal

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  logfs: remove from tree
  vfs: fix put_compat_statfs64() does not handle errors
  namei: fold should_follow_link() with the step into not-followed link
  namei: pass both WALK_GET and WALK_MORE to should_follow_link()
  namei: invert WALK_PUT logics
  namei: shift interpretation of LOOKUP_FOLLOW inside should_follow_link()
  namei: saner calling conventions for mountpoint_last()
  namei.c: get rid of user_path_parent()
  switch getfrag callbacks to ..._full() primitives
  make skb_add_data,{_nocache}() and skb_copy_to_page_nocache() advance only on success
  [iov_iter] new primitives - copy_from_iter_full() and friends
  don't open-code file_inode()
  ceph: switch to use of ->d_init()
  ceph: unify dentry_operations instances
  lustre: switch to use of ->d_init()

copy_from_iter_full(), copy_from_iter_full_nocache() and
csum_and_copy_from_iter_full() - counterparts of copy_from_iter()
et.al., advancing iterator only in case of successful full copy
and returning whether it had been successful or not.

Convert some obvious users.  *NOTE* - do not blindly assume that
something is a good candidate for those unless you are sure that
not advancing iov_iter in failure case is the right thing in
this case.  Anything that does short read/short write kind of
stuff (or is in a loop, etc.) is unlikely to be a good one.

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

Move READ and WRITE to kernel.h and don't define them in terms of block
layer ops; they are our generic data direction indicators these days
and have no more resemblance with the block layer ops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Pull splice fixups from Al Viro:
 "A couple of fixups for interaction of pipe-backed iov_iter with
  O_DIRECT reads + constification of a couple of primitives in uio.h
  missed by previous rounds.

  Kudos to davej - his fuzzing has caught those bugs"

* 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [btrfs] fix check_direct_IO() for non-iovec iterators
  constify iov_iter_count() and iter_is_iovec()
  fix ITER_PIPE interaction with direct_IO

Pull misc vfs updates from Al Viro:
 "Assorted misc bits and pieces.

  There are several single-topic branches left after this (rename2
  series from Miklos, current_time series from Deepa Dinamani, xattr
  series from Andreas, uaccess stuff from from me) and I'd prefer to
  send those separately"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
  proc: switch auxv to use of __mem_open()
  hpfs: support FIEMAP
  cifs: get rid of unused arguments of CIFSSMBWrite()
  posix_acl: uapi header split
  posix_acl: xattr representation cleanups
  fs/aio.c: eliminate redundant loads in put_aio_ring_file
  fs/internal.h: add const to ns_dentry_operations declaration
  compat: remove compat_printk()
  fs/buffer.c: make __getblk_slow() static
  proc: unsigned file descriptors
  fs/file: more unsigned file descriptors
  fs: compat: remove redundant check of nr_segs
  cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
  cifs: don't use memcpy() to copy struct iov_iter
  get rid of separate multipage fault-in primitives
  fs: Avoid premature clearing of capabilities
  fs: Give dentry to inode_change_ok() instead of inode
  fuse: Propagate dentry down to inode_change_ok()
  ceph: Propagate dentry down to inode_change_ok()
  xfs: Propagate dentry down to inode_change_ok()
  ...

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

iov_iter variant for passing data into pipe.  copy_to_iter()
copies data into page(s) it has allocated and stuffs them into
the pipe; copy_page_to_iter() stuffs there a reference to the
page given to it.  Both will try to coalesce if possible.
iov_iter_zero() is similar to copy_to_iter(); iov_iter_get_pages()
and friends will do as copy_to_iter() would have and return the
pages where the data would've been copied.  iov_iter_advance()
will truncate everything past the spot it has advanced to.

New primitive: iov_iter_pipe(), used for initializing those.
pipe should be locked all along.

Running out of space acts as fault would for iovec-backed ones;
in other words, giving it to ->read_iter() may result in short
read if the pipe overflows, or -EFAULT if it happens with nothing
copied there.

In other words, ->read_iter() on those acts pretty much like
->splice_read().  Moreover, all generic_file_splice_read() users,
as well as many other ->splice_read() instances can be switched
to that scheme - that'll happen in the next commit.

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

* the only remaining callers of "short" fault-ins are just as happy with generic
variants (both in lib/iov_iter.c); switch them to multipage variants, kill the
"short" ones
* rename the multipage variants to now available plain ones.
* get rid of compat macro defining iov_iter_fault_in_multipage_readable by
expanding it in its only user.

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

... by turning it into what used to be multipages counterpart

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

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