fuse: switch to iov_iter_get_pages()

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

1 files changed, 12 insertions, 21 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 10e9fcd8fe55..7db564d18dc6 100644
--- 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)