fuse: general infrastructure for pages[] of variable size

The patch removes inline array of FUSE_MAX_PAGES_PER_REQ page pointers from
fuse_req. Instead of that, req->pages may now point either to small inline
array or to an array allocated dynamically.

This essentially means that all callers of fuse_request_alloc[_nofs] should
pass the number of pages needed explicitly.

The patch doesn't make any logic changes.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 6f7d574..9a937f0 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1037,12 +1037,12 @@
 	/* only now - we want root dentry with NULL ->d_op */
 	sb->s_d_op = &fuse_dentry_operations;
 
-	init_req = fuse_request_alloc();
+	init_req = fuse_request_alloc(0);
 	if (!init_req)
 		goto err_put_root;
 
 	if (is_bdev) {
-		fc->destroy_req = fuse_request_alloc();
+		fc->destroy_req = fuse_request_alloc(0);
 		if (!fc->destroy_req)
 			goto err_free_init_req;
 	}