proc: warn on non-existing proc entries

* warn if creation goes on to non-existent directory
* warn if removal goes on from non-existing directory
* warn if non-existing proc entry is removed

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/generic.c

@@ -312,8 +312,10 @@ static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
 			if (proc_match(len, cp, de))
 				break;
 		}
-		if (!de)
+		if (!de) {
+			WARN(1, "name '%s'\n", name);
 			return -ENOENT;
+		}
 		cp += len + 1;
 	}
 	*residual = cp;
@@ -818,8 +820,10 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
 		}
 	}
 	spin_unlock(&proc_subdir_lock);
-	if (!de)
+	if (!de) {
+		WARN(1, "name '%s'\n", name);
 		return;
+	}
 
 	spin_lock(&de->pde_unload_lock);
 	/*