util: Move reopen_fd_as to reopen_fd_as_safe

[avagin@: Drop redundant fcntl call, and err variable]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>

include/util.h

@@ -164,11 +164,14 @@ extern void printk_vma(struct vma_area *vma_area);
 #define pr_info_registers(regs)		printk_registers(regs)
 #define pr_info_siginfo(siginfo)	printk_siginfo(siginfo)
 
-extern int reopen_fd_as(int new_fd, int old_fd);
 extern int move_img_fd(int *img_fd, int want_fd);
 extern int parse_maps(pid_t pid, struct list_head *vma_area_list, bool use_map_files);
 extern int close_safe(int *fd);
 
+extern int reopen_fd_as_safe(int new_fd, int old_fd, bool allow_reuse_fd);
+#define reopen_fd_as(new_fd, old_fd)		reopen_fd_as_safe(new_fd, old_fd, false)
+#define reopen_fd_as_nocheck(new_fd, old_fd)	reopen_fd_as_safe(new_fd, old_fd, true)
+
 extern void hex_dump(void *addr, unsigned long len);
 
 extern DIR *opendir_proc(char *fmt, ...);

util.c

@@ -128,24 +128,29 @@ int close_safe(int *fd)
 	return ret;
 }
 
-int reopen_fd_as(int new_fd, int old_fd)
+int reopen_fd_as_safe(int new_fd, int old_fd, bool allow_reuse_fd)
 {
+	int tmp;
+
 	if (old_fd != new_fd) {
-		int tmp;
-		tmp = fcntl(new_fd, F_GETFD);
-		if (tmp != -1 || errno != EBADF) {
-			/* Standard descriptors may be reused */
-			if (new_fd < 3)
-				pr_warning("fd=%d is already used\n", new_fd);
-			else {
-				pr_perror("fd=%d is already used\n", new_fd);
-				return -1;
+
+		if (!allow_reuse_fd) {
+			if (fcntl(new_fd, F_GETFD) != -1 || errno != EBADF) {
+				if (new_fd < 3) {
+					/*
+					 * Standart descriptors.
+					 */
+					pr_warning("fd = %d is already used\n", new_fd);
+				} else {
+					pr_err("fd = %d is already used\n", new_fd);
+					return -1;
+				}
 			}
 		}
 
 		tmp = dup2(old_fd, new_fd);
 		if (tmp < 0) {
-			pr_perror("Dup on %d -> %d failed\n", old_fd, new_fd);
+			pr_perror("Dup %d -> %d failed\n", old_fd, new_fd);
 			return tmp;
 		}