fsck: add fsck.mode and fsck.repair credentials support

Maybe useful when kernel command line is hard to change, e.g. when UKI
is used.

man/systemd-fsck@.service.xml

@@ -110,6 +110,34 @@
     </variablelist>
   </refsect1>
 
+  <refsect1>
+    <title>Credentials</title>
+
+    <para><command>systemd-fsck</command> supports the service credentials logic as implemented by
+    <varname>ImportCredential=</varname>/<varname>LoadCredential=</varname>/<varname>SetCredential=</varname>
+    (see <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+    details). The following credentials are used when passed in:</para>
+
+    <variablelist class='system-credentials'>
+      <varlistentry>
+        <term><varname>fsck.mode</varname></term>
+        <term><varname>fsck.repair</varname></term>
+
+        <listitem>
+          <para>The contents of the credentials are parsed as same as the kernel command line options with
+          the same name. See above for more details.</para>
+
+          <xi:include href="version-info.xml" xpointer="v258"/>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+
+    <para>Note that by default the <filename>systemd-fsck@.service</filename>,
+    <filename>systemd-fsck-root.service</filename>, and <filename>systemd-fsck-usr.service</filename> unit
+    files are set up to inherit both <varname>fsck.mode</varname> and <varname>fsck.repair</varname>
+    credentials from the service manager.</para>
+  </refsect1>
+
   <refsect1>
     <title>See Also</title>
     <para><simplelist type="inline">

man/systemd.system-credentials.xml

@@ -510,6 +510,20 @@
           <xi:include href="version-info.xml" xpointer="v258"/>
         </listitem>
       </varlistentry>
+
+      <varlistentry>
+        <term><varname>fsck.*</varname></term>
+
+        <listitem>
+          <para>Read by <filename>systemd-fsck@.service</filename>,
+          <filename>systemd-fsck-root.service</filename>, and <filename>systemd-fsck-usr.service</filename>.
+          See
+          <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+          for more details.</para>
+
+          <xi:include href="version-info.xml" xpointer="v258"/>
+        </listitem>
+      </varlistentry>
     </variablelist>
   </refsect1>
 

src/fsck/fsck.c

@@ -16,6 +16,7 @@
 #include "bus-error.h"
 #include "bus-locator.h"
 #include "bus-util.h"
+#include "creds-util.h"
 #include "device-util.h"
 #include "fd-util.h"
 #include "fs-util.h"
@@ -129,6 +130,31 @@ static int parse_proc_cmdline_item(const char *key, const char *value, void *dat
         return 0;
 }
 
+static void parse_credentials(void) {
+        _cleanup_free_ char *value = NULL;
+        int r;
+
+        r = read_credential("fsck.mode", (void**) &value, /* ret_size = */ NULL);
+        if (r < 0)
+                log_debug_errno(r, "Failed to read credential 'fsck.mode', ignoring: %m");
+        else {
+                arg_mode = fsck_mode_from_string(value);
+                if (arg_mode < 0)
+                        log_warning_errno(arg_mode, "Invalid 'fsck.mode' credential, ignoring: %s", value);
+        }
+
+        value = mfree(value);
+
+        r = read_credential("fsck.repair", (void**) &value, /* ret_size = */ NULL);
+        if (r < 0)
+                log_debug_errno(r, "Failed to read credential 'fsck.repair', ignoring: %m");
+        else {
+                arg_repair = fsck_repair_from_string(value);
+                if (arg_repair < 0)
+                        log_warning_errno(arg_repair, "Invalid 'fsck.repair' credential, ignoring: %s", value);
+        }
+}
+
 static double percent(int pass, unsigned long cur, unsigned long max) {
         /* Values stolen from e2fsck */
 
@@ -256,6 +282,8 @@ static int run(int argc, char *argv[]) {
         if (r < 0)
                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 
+        parse_credentials();
+
         bool show_progress = access("/run/systemd/show-status", F_OK) >= 0;
 
         if (arg_mode == FSCK_SKIP)

src/shared/generator.c

@@ -250,7 +250,8 @@ static int write_fsck_sysroot_service(
                 "Type=oneshot\n"
                 "RemainAfterExit=yes\n"
                 "ExecStart=" SYSTEMD_FSCK_PATH " %6$s\n"
-                "TimeoutSec=infinity\n",
+                "TimeoutSec=infinity\n"
+                "ImportCredential=fsck.*\n",
                 escaped,
                 unit,
                 device,

test/test-fstab-generator/test-12-dev-sdx.expected/systemd-fsck-root.service

@@ -15,3 +15,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/lib/systemd/systemd-fsck /dev/sdx1
 TimeoutSec=infinity
+ImportCredential=fsck.*

test/test-fstab-generator/test-13-label.expected/systemd-fsck-root.service

@@ -15,3 +15,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/lib/systemd/systemd-fsck /dev/disk/by-label/Root
 TimeoutSec=infinity
+ImportCredential=fsck.*

test/test-fstab-generator/test-14-uuid.expected/systemd-fsck-root.service

@@ -15,3 +15,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/lib/systemd/systemd-fsck /dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
 TimeoutSec=infinity
+ImportCredential=fsck.*

test/test-fstab-generator/test-15-partuuid.expected/systemd-fsck-root.service

@@ -15,3 +15,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/lib/systemd/systemd-fsck /dev/disk/by-partuuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
 TimeoutSec=infinity
+ImportCredential=fsck.*

test/test-fstab-generator/test-17-initrd-sysroot.fstab.expected/systemd-fsck-root.service

@@ -15,3 +15,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/lib/systemd/systemd-fsck /dev/sdx1
 TimeoutSec=infinity
+ImportCredential=fsck.*

test/test-fstab-generator/test-18-options.fstab.expected/systemd-fsck-root.service

@@ -15,3 +15,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/lib/systemd/systemd-fsck /dev/sdx1
 TimeoutSec=infinity
+ImportCredential=fsck.*

test/test-fstab-generator/test-19-mounts-from-cmdline.expected/systemd-fsck-root.service

@@ -15,3 +15,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/lib/systemd/systemd-fsck /dev/sdx1
 TimeoutSec=infinity
+ImportCredential=fsck.*

test/test-fstab-generator/test-19-mounts-from-cmdline.expected/systemd-fsck-usr.service

@@ -15,3 +15,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/lib/systemd/systemd-fsck /dev/sdx5
 TimeoutSec=infinity
+ImportCredential=fsck.*

units/systemd-fsck-root.service.in

@@ -22,3 +22,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart={{LIBEXECDIR}}/systemd-fsck
 TimeoutSec=infinity
+ImportCredential=fsck.*

units/systemd-fsck@.service.in

@@ -22,3 +22,4 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart={{LIBEXECDIR}}/systemd-fsck %f
 TimeoutSec=infinity
+ImportCredential=fsck.*