From 85a6fabdd3e43cfab0fc6359e9f2a9e368d4a3ed Mon Sep 17 00:00:00 2001

From: Michal Schmidt <mschmidt@redhat.com>

Date: Mon, 16 Mar 2015 22:04:21 +0100

Subject: [PATCH] core/namespace: fix path sorting

The comparison function we use for qsorting paths is overly indifferent.

Consider these 3 paths for sorting:

 /foo

 /bar

 /foo/foo

qsort() may compare:

 "/foo" with "/bar" => 0, indifference

 "/bar" with "/foo/foo" => 0, indifference

and assume transitively that "/foo" and "/foo/foo" are also indifferent.

But this is wrong, we want "/foo" sorted before "/foo/foo".

The comparison function must be transitive.

Use path_compare(), which behaves properly.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1184016

(cherry picked from commit a0827e2b123010c46cfe4f03eebba57d92f9efc4)

---

 src/core/namespace.c | 12 ++++--------

 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/core/namespace.c b/src/core/namespace.c

index 4fecd32363..d4f1c86211 100644

--- a/src/core/namespace.c

+++ b/src/core/namespace.c

@@ -91,9 +91,11 @@ static int append_mounts(BindMount **p, char **strv, MountMode mode) {

 static int mount_path_compare(const void *a, const void *b) {

         const BindMount *p = a, *q = b;

+        int d;

-        if (path_equal(p->path, q->path)) {

+        d = path_compare(p->path, q->path);

+        if (!d) {

                 /* If the paths are equal, check the mode */

                 if (p->mode < q->mode)

                         return -1;

@@ -105,13 +107,7 @@ static int mount_path_compare(const void *a, const void *b) {

         }

         /* If the paths are not equal, then order prefixes first */

-        if (path_startswith(p->path, q->path))

-                return 1;

-

-        if (path_startswith(q->path, p->path))

-                return -1;

-

-        return 0;

+        return d;

 }

 static void drop_duplicates(BindMount *m, unsigned *n) {