From 5aa2be25e7de16f4d3ff3b322cf8c35574e712c5 Mon Sep 17 00:00:00 2001

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

Date: Wed, 16 Mar 2022 09:51:24 +0100

Subject: [PATCH] =?UTF-8?q?shared/install:=20also=20remove=20symlinks=20li?=

 =?UTF-8?q?ke=20.wants/foo@one.service=20=E2=86=92=20../foo@one.service?=

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So far 'systemctl enable' would create absolute links to the target template

name. And we would remove such symlinks just fine. But the user may create

symlinks manually in a different form. In particular, symlinks for instanced

units *must* have the instance in the source name, and then it is natural to

also include it in the target name (.wants/foo@one.service → ../foo@one.service

rather than .wants/foo@one.service → ../foo@.service). We would choke on such

links, or not remove them at all. A test is added:

before:

+ build-rawhide/systemctl --root=/tmp/systemctl-test.001xda disable templ1@.service

Removed "/tmp/systemctl-test.001xda/etc/systemd/system/services.target.wants/templ1@seven.service".

Removed "/tmp/systemctl-test.001xda/etc/systemd/system/services.target.wants/templ1@six.service".

Removed "/tmp/systemctl-test.001xda/etc/systemd/system/services.target.wants/templ1@five.service".

Removed "/tmp/systemctl-test.001xda/etc/systemd/system/services.target.wants/templ1@four.service".

Removed "/tmp/systemctl-test.001xda/etc/systemd/system/services.target.wants/templ1@three.service".

Failed to disable unit, refusing to operate on linked unit file /tmp/systemctl-test.001xda/etc/systemd/system/services.target.wants/templ1@two.service.

Failed to disable unit, refusing to operate on linked unit file /tmp/systemctl-test.001xda/etc/systemd/system/services.target.wants/templ1@two.service.

after:

+ build-rawhide/systemctl --root=/tmp/systemctl-test.QVP0ev disable templ1@.service

Removed "/tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@seven.service".

Removed "/tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@six.service".

Removed "/tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@five.service".

Removed "/tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@four.service".

Removed "/tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@three.service".

Removed "/tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@two.service".

Removed "/tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@one.service".

+ test '!' -h /tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@one.service

+ test '!' -h /tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@two.service

+ test '!' -h /tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@three.service

+ test '!' -h /tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@four.service

+ test '!' -h /tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@five.service

+ test '!' -h /tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@six.service

+ test '!' -h /tmp/systemctl-test.QVP0ev/etc/systemd/system/services.target.wants/templ1@seven.service

(cherry picked from commit 9f61c9f79e0f77044b71ef2ba5edde20e15c6ad2)

Related: #2082131

---

 src/shared/install.c          | 16 +++++++++++++---

 test/test-systemctl-enable.sh | 20 ++++++++++++++++++++

 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/shared/install.c b/src/shared/install.c

index 08a9892260..43955519ae 100644

--- a/src/shared/install.c

+++ b/src/shared/install.c

@@ -612,13 +612,23 @@ static int remove_marked_symlinks_fd(

                         path_simplify(p);

                         /* We remove all links pointing to a file or path that is marked, as well as all

-                         * files sharing the same name as a file that is marked. Do path chasing only if

-                         * we don't already know that we want to remove the symlink. */

+                         * files sharing the same name as a file that is marked, and files sharing the same

+                         * name after the instance has been removed. Do path chasing only if we don't already

+                         * know that we want to remove the symlink. */

                         found = set_contains(remove_symlinks_to, de->d_name);

                         if (!found) {

-                                _cleanup_free_ char *dest = NULL;

+                                _cleanup_free_ char *template = NULL;

+

+                                q = unit_name_template(de->d_name, &template);

+                                if (q < 0 && q != -EINVAL)

+                                        return q;

+                                if (q >= 0)

+                                        found = set_contains(remove_symlinks_to, template);

+                        }

+                        if (!found) {

+                                _cleanup_free_ char *dest = NULL;

                                 q = chase_symlinks(p, lp->root_dir, CHASE_NONEXISTENT, &dest, NULL);

                                 if (q == -ENOENT)

diff --git a/test/test-systemctl-enable.sh b/test/test-systemctl-enable.sh

index 220ebfdab7..4462fb386e 100644

--- a/test/test-systemctl-enable.sh

+++ b/test/test-systemctl-enable.sh

@@ -333,6 +333,26 @@ test ! -h "$root/etc/systemd/system/other@templ1.target.requires/templ1@one.serv

 test ! -h "$root/etc/systemd/system/services.target.wants/templ1@two.service"

 test ! -h "$root/etc/systemd/system/other@templ1.target.requires/templ1@two.service"

+: -------removal of relative enablement symlinks--------------

+test ! -h "$root/etc/systemd/system/services.target.wants/templ1@.service"

+ln -s '../templ1@one.service' "$root/etc/systemd/system/services.target.wants/templ1@one.service"

+ln -s 'templ1@two.service' "$root/etc/systemd/system/services.target.wants/templ1@two.service"

+ln -s '../templ1@.service' "$root/etc/systemd/system/services.target.wants/templ1@three.service"

+ln -s 'templ1@.service' "$root/etc/systemd/system/services.target.wants/templ1@four.service"

+ln -s '/usr/lib/systemd/system/templ1@.service' "$root/etc/systemd/system/services.target.wants/templ1@five.service"

+ln -s '/etc/systemd/system/templ1@.service' "$root/etc/systemd/system/services.target.wants/templ1@six.service"

+ln -s '/run/system/templ1@.service' "$root/etc/systemd/system/services.target.wants/templ1@seven.service"

+

+# this should remove all links

+"$systemctl" --root="$root" disable 'templ1@.service'

+test ! -h "$root/etc/systemd/system/services.target.wants/templ1@one.service"

+test ! -h "$root/etc/systemd/system/services.target.wants/templ1@two.service"

+test ! -h "$root/etc/systemd/system/services.target.wants/templ1@three.service"

+test ! -h "$root/etc/systemd/system/services.target.wants/templ1@four.service"

+test ! -h "$root/etc/systemd/system/services.target.wants/templ1@five.service"

+test ! -h "$root/etc/systemd/system/services.target.wants/templ1@six.service"

+test ! -h "$root/etc/systemd/system/services.target.wants/templ1@seven.service"

+

 : -------template enablement for another template-------------

 cat >"$root/etc/systemd/system/templ2@.service" <

 [Install]