dax: Use copy_from_iter_nocache

Matthew Wilcox · Al Viro · commit 872eb127e3a6 · 2015-07-04T15:56:56.000-04:00
When userspace does a write, there's no need for the written data to
pollute the CPU cache.  This matches the original XIP code.

Signed-off-by: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
diff --git a/fs/dax.c b/fs/dax.c
@@ -155,7 +155,7 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
 		}
 
 		if (iov_iter_rw(iter) == WRITE)
-			len = copy_from_iter(addr, max - pos, iter);
+			len = copy_from_iter_nocache(addr, max - pos, iter);
 		else if (!hole)
 			len = copy_to_iter(addr, max - pos, iter);
 		else

Original file line number	Diff line number	Diff line change
`@@ -155,7 +155,7 @@ static ssize_t dax_io(struct inode inode, struct iov_iter iter,`
`155`	`155`	`}`
`156`	`156`
`157`	`157`	`if (iov_iter_rw(iter) == WRITE)`
`158`		`- len = copy_from_iter(addr, max - pos, iter);`
	`158`	`+ len = copy_from_iter_nocache(addr, max - pos, iter);`
`159`	`159`	`else if (!hole)`
`160`	`160`	`len = copy_to_iter(addr, max - pos, iter);`
`161`	`161`	`else`