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>

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 82a66466a24c5a0c47661ac9effc6ce3b2a5df1b..fa466d88a6b9b7a9764417ace3b5df66abe018ec 100644 (file)
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1637,30 +1637,17 @@ 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;