fuse: switch to iov_iter_get_pages()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index aa509f62a4af08223e08477ccef4d98a4e12548c..c00f00172c4b7cd82e66ae899a9319c989a7c845 100644 (file)
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1294,7 +1294,7 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
        size_t nbytes = 0;  /* # bytes already packed in req */
 
        /* Special case for kernel I/O: can copy directly into the buffer */
-       if (segment_eq(get_fs(), KERNEL_DS)) {
+       if (ii->type & REQ_KERNEL) {
                unsigned long user_addr = fuse_get_user_addr(ii);
                size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
 
@@ -1310,35 +1310,26 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
 
        while (nbytes < *nbytesp && req->num_pages < req->max_pages) {
                unsigned npages;
-               unsigned long user_addr = fuse_get_user_addr(ii);
-               unsigned offset = user_addr & ~PAGE_MASK;
-               size_t frag_size = fuse_get_frag_size(ii, *nbytesp - nbytes);
-               int ret;
-
+               size_t start, end, frag_size;
                unsigned n = req->max_pages - req->num_pages;
-               frag_size = min_t(size_t, frag_size, n << PAGE_SHIFT);
-
-               npages = (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
-               npages = clamp(npages, 1U, n);
-
-               ret = get_user_pages_fast(user_addr, npages, !write,
-                                         &req->pages[req->num_pages]);
+               ssize_t ret = iov_iter_get_pages(ii,
+                                       &req->pages[req->num_pages],
+                                       n * PAGE_SIZE, &start);
                if (ret < 0)
                        return ret;
 
-               npages = ret;
-               frag_size = min_t(size_t, frag_size,
-                                 (npages << PAGE_SHIFT) - offset);
-               iov_iter_advance(ii, frag_size);
+               iov_iter_advance(ii, ret);
+               nbytes += ret;
 
-               req->page_descs[req->num_pages].offset = offset;
+               ret += start;
+               npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE;
+
+               req->page_descs[req->num_pages].offset = start;
                fuse_page_descs_length_init(req, req->num_pages, npages);
 
                req->num_pages += npages;
                req->page_descs[req->num_pages - 1].length -=
-                       (npages << PAGE_SHIFT) - offset - frag_size;
-
-               nbytes += frag_size;
+                       (PAGE_SIZE - ret) & (PAGE_SIZE - 1);
        }
 
        if (write)