From: Dave Kleikamp <dave.kleikamp@oracle.com>
Date: Fri, 14 Jun 2013 20:54:11 +0000 (-0500)
Subject: fuse: convert fuse to use iov_iter_copy_[to|from]_user
X-Git-Tag: next-20130822~107^2~28
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=efc83637e4c48fda97e3c045d773834c86ea1572;p=karo-tx-linux.git

fuse: convert fuse to use iov_iter_copy_[to|from]_user

A future patch hides the internals of struct iov_iter, so fuse should
be using the supported interface.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Acked-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: fuse-devel@lists.sourceforge.net
---

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 5c121fe19c5f..633766ce6a16 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1861,30 +1861,17 @@ static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
 	while (iov_iter_count(&ii)) {
 		struct page *page = pages[page_idx++];
 		size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
-		void *kaddr;
+		size_t left;
 
-		kaddr = kmap(page);
-
-		while (todo) {
-			char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
-			size_t iov_len = ii.iov->iov_len - ii.iov_offset;
-			size_t copy = min(todo, iov_len);
-			size_t left;
-
-			if (!to_user)
-				left = copy_from_user(kaddr, uaddr, copy);
-			else
-				left = copy_to_user(uaddr, kaddr, copy);
-
-			if (unlikely(left))
-				return -EFAULT;
+		if (!to_user)
+			left = iov_iter_copy_from_user(page, &ii, 0, todo);
+		else
+			left = iov_iter_copy_to_user(page, &ii, 0, todo);
 
-			iov_iter_advance(&ii, copy);
-			todo -= copy;
-			kaddr += copy;
-		}
+		if (unlikely(left))
+			return -EFAULT;
 
-		kunmap(page);
+		iov_iter_advance(&ii, todo);
 	}
 
 	return 0;