From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon, 10 Oct 2016 20:38:49 +0000 (-0700)
Subject: Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git... 
X-Git-Tag: v4.9-rc1~56
X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=fed41f7d039bad02f94cad9059e4b14cd81d13f2

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

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
---

fed41f7d039bad02f94cad9059e4b14cd81d13f2
diff --cc mm/filemap.c
index 2f7b7783bd6b,6b965efe215e..849f459ad078
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@@ -1935,13 -1915,12 +1935,13 @@@ generic_file_read_iter(struct kiocb *io
  		size = i_size_read(inode);
  		retval = filemap_write_and_wait_range(mapping, iocb->ki_pos,
  					iocb->ki_pos + count - 1);
 -		if (!retval) {
 -			struct iov_iter data = *iter;
 -			retval = mapping->a_ops->direct_IO(iocb, &data);
 -		}
 +		if (retval < 0)
 +			goto out;
  
 +		file_accessed(file);
 +
 +		retval = mapping->a_ops->direct_IO(iocb, &data);
- 		if (retval > 0) {
+ 		if (retval >= 0) {
  			iocb->ki_pos += retval;
  			iov_iter_advance(iter, retval);
  		}