Merge pull request #18124 from ryncsn/initrd

initrd: add an env variable to accept non-ramfs rootfs

1 files changed, 39 insertions, 10 deletions

diff --git a/src/basic/util.c b/src/basic/util.c
index 7c708eb3be..d24d52190c 100644
--- a/src/basic/util.c
+++ b/src/basic/util.c
@@ -52,13 +52,14 @@ int prot_from_flags(int flags) {
 }
 
 bool in_initrd(void) {
-        struct statfs s;
         int r;
+        const char *e;
+        bool lenient = false;
 
         if (saved_in_initrd >= 0)
                 return saved_in_initrd;
 
-        /* We make two checks here:
+        /* We have two checks here:
          *
          * 1. the flag file /etc/initrd-release must exist
          * 2. the root file system must be a memory file system
@@ -66,18 +67,46 @@ bool in_initrd(void) {
          * The second check is extra paranoia, since misdetecting an
          * initrd can have bad consequences due the initrd
          * emptying when transititioning to the main systemd.
+         *
+         * If env var $SYSTEMD_IN_INITRD is not set or set to "auto",
+         * both checks are used. If it's set to "lenient", only check
+         * 1 is used. If set to a booleen value, then the boolean
+         * value is returned.
          */
 
-        r = getenv_bool_secure("SYSTEMD_IN_INITRD");
-        if (r < 0 && r != -ENXIO)
-                log_debug_errno(r, "Failed to parse $SYSTEMD_IN_INITRD, ignoring: %m");
+        e = secure_getenv("SYSTEMD_IN_INITRD");
+        if (e) {
+                if (streq(e, "lenient"))
+                        lenient = true;
+                else if (!streq(e, "auto")) {
+                        r = parse_boolean(e);
+                        if (r >= 0) {
+                                saved_in_initrd = r > 0;
+                                return saved_in_initrd;
+                        }
+                        log_debug_errno(r, "Failed to parse $SYSTEMD_IN_INITRD, ignoring: %m");
+                }
+        }
+
+        if (!lenient) {
+                r = path_is_temporary_fs("/");
+                if (r < 0)
+                        log_debug_errno(r, "Couldn't determine if / is a temporary file system: %m");
 
-        if (r >= 0)
                 saved_in_initrd = r > 0;
-        else
-                saved_in_initrd = access("/etc/initrd-release", F_OK) >= 0 &&
-                                  statfs("/", &s) >= 0 &&
-                                  is_temporary_fs(&s);
+        }
+
+        r = access("/etc/initrd-release", F_OK);
+        if (r >= 0) {
+                if (saved_in_initrd == 0)
+                        log_debug("/etc/initrd-release exists, but it's not an initrd.");
+                else
+                        saved_in_initrd = 1;
+        } else {
+                if (errno != ENOENT)
+                        log_debug_errno(errno, "Failed to test if /etc/initrd-release exists: %m");
+                saved_in_initrd = 0;
+        }
 
         return saved_in_initrd;
 }