From bedb539662380d6a120db1e8dbb63b55d2ecac2c Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Wed, 11 Dec 2013 22:00:33 -0500

Subject: [PATCH] nspawn: complain and continue if machine has same id

If --link-journal=host or --link-journal=guest is used, this totally

cannot work and we exit with an error. If however --link-journal=auto

or --link-journal=no is used, just display a warning.

Having the same machine id can happen if booting from the same

filesystem as the host. Since other things mostly function correctly,

let's allow that.

https://bugs.freedesktop.org/show_bug.cgi?id=68369

---

 src/nspawn/nspawn.c | 23 +++++++++++++++++++----

 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c

index 7346253..618f9c3 100644

--- a/src/nspawn/nspawn.c

+++ b/src/nspawn/nspawn.c

@@ -811,14 +811,11 @@ static int setup_hostname(void) {

 }

 static int setup_journal(const char *directory) {

-        sd_id128_t machine_id;

+        sd_id128_t machine_id, this_id;

         _cleanup_free_ char *p = NULL, *b = NULL, *q = NULL, *d = NULL;

         char *id;

         int r;

-        if (arg_link_journal == LINK_NO)

-                return 0;

-

         p = strappend(directory, "/etc/machine-id");

         if (!p)

                 return log_oom();

@@ -842,6 +839,24 @@ static int setup_journal(const char *directory) {

                 return r;

         }

+        r = sd_id128_get_machine(&this_id);

+        if (r < 0) {

+                log_error("Failed to retrieve machine ID: %s", strerror(-r));

+                return r;

+        }

+

+        if (sd_id128_equal(machine_id, this_id)) {

+                log_full(arg_link_journal == LINK_AUTO ? LOG_WARNING : LOG_ERR,

+                         "Host and machine ids are equal (%s): refusing to link journals", id);

+                if (arg_link_journal == LINK_AUTO)

+                        return 0;

+                return

+                        -EEXIST;

+        }

+

+        if (arg_link_journal == LINK_NO)

+                return 0;

+

         free(p);

         p = strappend("/var/log/journal/", id);

         q = strjoin(directory, "/var/log/journal/", id, NULL);