fsnotify: Add debug printing of the target link

Convenient for debug.

 | (00.005999)   3857: fsnotify:           Restore inotify watch for 0x00800002:0x0000000000000002 (via /proc/self/fd/5 -> /)
 | (00.005999)   3857: fsnotify:           Restore inotify watch for 0x00800002:0x0000000000083a93 (via /home/criu/test/zdtm/live/static/inotify-removed (deleted).cr.1.ghost)
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

fsnotify.c

@@ -208,13 +208,23 @@ static char *get_mark_path(const char *who, struct file_remap *remap,
 		}
 		snprintf(buf, size, "/proc/self/fd/%d", *target);
 		path = buf;
+
+		if (log_get_loglevel() >= LOG_DEBUG) {
+			char link[PATH_MAX];
+
+			if (read_fd_link(*target, link, sizeof(link)) < 0)
+				link[0] = '\0';
+
+			pr_debug("\t\tRestore %s watch for 0x%08x:0x%016lx (via %s -> %s)\n",
+				 who, s_dev, i_ino, path, link);
+		}
 	} else {
 		*target = -1;
 		path = remap->path;
-	}
 
-	pr_debug("\t\tRestore %s watch for 0x%08x:0x%016lx (via %s)\n",
-		 who, s_dev, i_ino, path);
+		pr_debug("\t\tRestore %s watch for 0x%08x:0x%016lx (via %s)\n",
+			 who, s_dev, i_ino, path);
+	}
 
 err:
 	close_safe(&mntfd);