From 94f9a80db599dcc298f3058e5cf2bb60c4972228 Mon Sep 17 00:00:00 2001

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

Date: Thu, 24 Nov 2022 13:58:39 +0100

Subject: [PATCH] Revert "initrd: extend SYSTEMD_IN_INITRD to accept non-ramfs

 rootfs"

This reverts commit 1f22621ba33f8089d2ae5fbcaf8b3970dd68aaf0.

This is a replacement for b1fd5cd4eda02a323db93d7daa97f5138f89677d. See that

commit for details.

Related: #2138081

---

 docs/ENVIRONMENT.md | 10 +++-------

 src/basic/util.c    | 47 ++++++++-------------------------------------

 2 files changed, 11 insertions(+), 46 deletions(-)

diff --git a/docs/ENVIRONMENT.md b/docs/ENVIRONMENT.md

index a840dd0c90..ab3add6031 100644

--- a/docs/ENVIRONMENT.md

+++ b/docs/ENVIRONMENT.md

@@ -73,13 +73,9 @@ All tools:

   (relevant in particular for the system manager and `systemd-hostnamed`).

   Must be a valid hostname (either a single label or a FQDN).

-* `$SYSTEMD_IN_INITRD=[auto|lenient|0|1]` — if set, specifies initrd detection

-  method. Defaults to `auto`. Behavior is defined as follows:

-  `auto`: Checks if `/etc/initrd-release` exists, and a temporary fs is mounted

-          on `/`. If both conditions meet, then it's in initrd.

-  `lenient`: Similar to `auto`, but the rootfs check is skipped.

-  `0|1`: Simply overrides initrd detection. This is useful for debugging and

-         testing initrd-only programs in the main system.

+* `$SYSTEMD_IN_INITRD` — takes a boolean. If set, overrides initrd detection.

+  This is useful for debugging and testing initrd-only programs in the main

+  system.

 * `$SYSTEMD_BUS_TIMEOUT=SECS` — specifies the maximum time to wait for method call

   completion. If no time unit is specified, assumes seconds. The usual other units

diff --git a/src/basic/util.c b/src/basic/util.c

index d7ef382737..981f917fab 100644

--- a/src/basic/util.c

+++ b/src/basic/util.c

@@ -52,13 +52,11 @@ int prot_from_flags(int flags) {

 bool in_initrd(void) {

         int r;

-        const char *e;

-        bool lenient = false;

         if (saved_in_initrd >= 0)

                 return saved_in_initrd;

-        /* We have two checks here:

+        /* 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

@@ -66,46 +64,17 @@ 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 boolean value, then the boolean

-         * value is returned.

          */

-        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");

+        r = getenv_bool_secure("SYSTEMD_IN_INITRD");

+        if (r < 0 && r != -ENXIO)

+                log_debug_errno(r, "Failed to parse $SYSTEMD_IN_INITRD, ignoring: %m");

+        if (r >= 0)

                 saved_in_initrd = r > 0;

-        }

-

-        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;

-        }

+        else

+                saved_in_initrd = access("/etc/initrd-release", F_OK) >= 0 &&

+                                  path_is_temporary_fs("/") > 0;

         return saved_in_initrd;

 }