Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs updates from Al Viro:
 "This the bunch that sat in -next + lock_parent() fix.  This is the
  minimal set; there's more pending stuff.

  In particular, I really hope to get acct.c fixes merged this cycle -
  we need that to deal sanely with delayed-mntput stuff.  In the next
  pile, hopefully - that series is fairly short and localized
  (kernel/acct.c, fs/super.c and fs/namespace.c).  In this pile: more
  iov_iter work.  Most of prereqs for ->splice_write with sane locking
  order are there and Kent's dio rewrite would also fit nicely on top of
  this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (70 commits)
  lock_parent: don't step on stale ->d_parent of all-but-freed one
  kill generic_file_splice_write()
  ceph: switch to iter_file_splice_write()
  shmem: switch to iter_file_splice_write()
  nfs: switch to iter_splice_write_file()
  fs/splice.c: remove unneeded exports
  ocfs2: switch to iter_file_splice_write()
  ->splice_write() via ->write_iter()
  bio_vec-backed iov_iter
  optimize copy_page_{to,from}_iter()
  bury generic_file_aio_{read,write}
  lustre: get rid of messing with iovecs
  ceph: switch to ->write_iter()
  ceph_sync_direct_write: stop poking into iov_iter guts
  ceph_sync_read: stop poking into iov_iter guts
  new helper: copy_page_from_iter()
  fuse: switch to ->write_iter()
  btrfs: switch to ->write_iter()
  ocfs2: switch to ->write_iter()
  xfs: switch to ->write_iter()
  ...

2 files changed, 12 insertions, 6 deletions

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index eba790134253..b18dd1779029 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -196,8 +196,7 @@ prototypes:
         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
         int (*releasepage) (struct page *, int);
         void (*freepage)(struct page *);
-        int (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
-                        loff_t offset, unsigned long nr_segs);
+        int (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
         int (*get_xip_mem)(struct address_space *, pgoff_t, int, void **,
                                 unsigned long *);
         int (*migratepage)(struct address_space *, struct page *, struct page *);
@@ -431,6 +430,8 @@ prototypes:
         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
         ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
         ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+        ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
+        ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
         int (*iterate) (struct file *, struct dir_context *);
         unsigned int (*poll) (struct file *, struct poll_table_struct *);
         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 617f6d70c077..a1d0d7a30165 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -589,8 +589,7 @@ struct address_space_operations {
         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
         int (*releasepage) (struct page *, int);
         void (*freepage)(struct page *);
-        ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
-                        loff_t offset, unsigned long nr_segs);
+        ssize_t (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
         struct page* (*get_xip_page)(struct address_space *, sector_t,
                         int);
         /* migrate the contents of a page to the specified target */
@@ -807,6 +806,8 @@ struct file_operations {
         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
         ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
         ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+        ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
+        ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
         int (*iterate) (struct file *, struct dir_context *);
         unsigned int (*poll) (struct file *, struct poll_table_struct *);
         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
@@ -837,11 +838,15 @@ otherwise noted.
 
   read: called by read(2) and related system calls
 
-  aio_read: called by io_submit(2) and other asynchronous I/O operations
+  aio_read: vectored, possibly asynchronous read
+
+  read_iter: possibly asynchronous read with iov_iter as destination
 
   write: called by write(2) and related system calls
 
-  aio_write: called by io_submit(2) and other asynchronous I/O operations
+  aio_write: vectored, possibly asynchronous write
+
+  write_iter: possibly asynchronous write with iov_iter as source
 
   iterate: called when the VFS needs to read the directory contents