mm: gup: use get_user_pages_fast instead of get_user_pages_unlocked

Just an optimization, where possible use get_user_pages_fast.

drivers/scsi/st.c

@@ -4552,13 +4552,10 @@ static int sgl_map_user_pages(struct st_buffer *STbp,
 
         /* Try to fault in all of the necessary pages */
         /* rw==READ means read from drive, write into memory area */
-	res = get_user_pages_unlocked(
-		current,
-		current->mm,
+	res = get_user_pages_fast(
 		uaddr,
 		nr_pages,
 		rw == READ,
-		0, /* don't force */
 		pages);
 
 	/* Errors and no page mapped should return here */

drivers/video/fbdev/pvr2fb.c

@@ -686,8 +686,7 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
 	if (!pages)
 		return -ENOMEM;
 
-	ret = get_user_pages_unlocked(current, current->mm, (unsigned long)buf,
-				      nr_pages, WRITE, 0, pages);
+	ret = get_user_pages_fast((unsigned long)buf, nr_pages, WRITE, pages);
 
 	if (ret < nr_pages) {
 		nr_pages = ret;

net/ceph/pagevec.c

@@ -24,9 +24,10 @@ struct page **ceph_get_direct_page_vector(const void __user *data,
 		return ERR_PTR(-ENOMEM);
 
 	while (got < num_pages) {
-		rc = get_user_pages_unlocked(current, current->mm,
-		    (unsigned long)data + ((unsigned long)got * PAGE_SIZE),
-		    num_pages - got, write_page, 0, pages + got);
+		rc = get_user_pages_fast((unsigned long)data +
+					 ((unsigned long)got * PAGE_SIZE),
+					 num_pages - got,
+					 write_page, pages + got);
 		if (rc < 0)
 			break;
 		BUG_ON(rc == 0);