Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull VFS splice updates from Al Viro:
 "There's a bunch of branches this cycle, both mine and from other folks
  and I'd rather send pull requests separately.

  This one is the conversion of ->splice_read() to ITER_PIPE iov_iter
  (and introduction of such). Gets rid of a lot of code in fs/splice.c
  and elsewhere; there will be followups, but these are for the next
  cycle...  Some pipe/splice-related cleanups from Miklos in the same
  branch as well"

* 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  pipe: fix comment in pipe_buf_operations
  pipe: add pipe_buf_steal() helper
  pipe: add pipe_buf_confirm() helper
  pipe: add pipe_buf_release() helper
  pipe: add pipe_buf_get() helper
  relay: simplify relay_file_read()
  switch default_file_splice_read() to use of pipe-backed iov_iter
  switch generic_file_splice_read() to use of ->read_iter()
  new iov_iter flavour: pipe-backed
  fuse_dev_splice_read(): switch to add_to_pipe()
  skb_splice_bits(): get rid of callback
  new helper: add_to_pipe()
  splice: lift pipe_lock out of splice_to_pipe()
  splice: switch get_iovec_page_array() to iov_iter
  splice_to_pipe(): don't open-code wakeup_pipe_readers()
  consistent treatment of EFAULT on O_DIRECT read/write

1 files changed, 11 insertions, 3 deletions

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 75b4aaf31a9d..b5ebe6dca404 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -13,6 +13,7 @@
 #include <uapi/linux/uio.h>
 
 struct page;
+struct pipe_inode_info;
 
 struct kvec {
 	void *iov_base; /* and that should *never* hold a userland pointer */
@@ -23,6 +24,7 @@ enum {
 	ITER_IOVEC = 0,
 	ITER_KVEC = 2,
 	ITER_BVEC = 4,
+	ITER_PIPE = 8,
 };
 
 struct iov_iter {
@@ -33,8 +35,12 @@ struct iov_iter {
 		const struct iovec *iov;
 		const struct kvec *kvec;
 		const struct bio_vec *bvec;
+		struct pipe_inode_info *pipe;
+	};
+	union {
+		unsigned long nr_segs;
+		int idx;
 	};
-	unsigned long nr_segs;
 };
 
 /*
@@ -64,7 +70,7 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
 }
 
 #define iov_for_each(iov, iter, start)				\
-	if (!((start).type & ITER_BVEC))			\
+	if (!((start).type & (ITER_BVEC | ITER_PIPE)))		\
 	for (iter = (start);					\
 	     (iter).count &&					\
 	     ((iov = iov_iter_iovec(&(iter))), 1);		\
@@ -94,6 +100,8 @@ void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec,
 			unsigned long nr_segs, size_t count);
 void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec,
 			unsigned long nr_segs, size_t count);
+void iov_iter_pipe(struct iov_iter *i, int direction, struct pipe_inode_info *pipe,
+			size_t count);
 ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
 			size_t maxsize, unsigned maxpages, size_t *start);
 ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
@@ -109,7 +117,7 @@ static inline size_t iov_iter_count(struct iov_iter *i)
 
 static inline bool iter_is_iovec(struct iov_iter *i)
 {
-	return !(i->type & (ITER_BVEC | ITER_KVEC));
+	return !(i->type & (ITER_BVEC | ITER_KVEC | ITER_PIPE));
 }
 
 /*