X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=8caac7b597fb0f3393c77e1ad2fce3fabdb91bb3;hp=41505b2ca79bac962510704a22c65fbea92ba2df;hb=825c6fe5eb362437aa46faa52b683a62eede9a13;hpb=36fcd77e02cedf300e2f45f2449e7e091ef5a7ab

diff --git a/src/shared/util.c b/src/shared/util.c
index 41505b2ca..8caac7b59 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -54,6 +54,8 @@
 #include <glob.h>
 #include <grp.h>
 #include <sys/mman.h>
+#include <sys/vfs.h>
+#include <linux/magic.h>
 
 #include "macro.h"
 #include "util.h"
@@ -5738,9 +5740,24 @@ bool is_valid_documentation_url(const char *url) {
 
 bool in_initrd(void) {
         static int saved = -1;
+        struct statfs s;
 
-        if (saved < 0)
-                saved = access("/etc/initrd-release", F_OK) >= 0;
+        if (saved >= 0)
+                return saved;
+
+        /* We make two checks here:
+         *
+         * 1. the flag file /etc/initrd-release must exist
+         * 2. the root file system must be a memory file system
+         *
+         * The second check is extra paranoia, since misdetecting an
+         * initrd can have bad bad consequences due the initrd
+         * emptying when transititioning to the main systemd.
+         */
+
+        saved = access("/etc/initrd-release", F_OK) >= 0 &&
+                statfs("/", &s) >= 0 &&
+                (s.f_type == TMPFS_MAGIC || s.f_type == RAMFS_MAGIC);
 
         return saved;
 }