fuse_ioctl_copy_user(): don't open-code copy_page_{to,from}_iter()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

1 files changed, 7 insertions, 23 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 3988b43c2f5a..4c1db6ce7c48 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2339,31 +2339,15 @@ 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 copied;
 
-                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;
-
-                        iov_iter_advance(&ii, copy);
-                        todo -= copy;
-                        kaddr += copy;
-                }
+                if (!to_user)
+                        copied = copy_page_from_iter(page, 0, PAGE_SIZE, &ii);
+                else
+                        copied = copy_page_to_iter(page, 0, PAGE_SIZE, &ii);
 
-                kunmap(page);
+                if (unlikely(copied != PAGE_SIZE && iov_iter_count(&ii)))
+                        return -EFAULT;
         }
 
         return 0;