Merge pull request #24645 from Mic92/stage-2

Stage-2 cleanup

nixos/modules/system/boot/readonly-mountpoint.c

@@ -1,20 +0,0 @@
-#include <sys/statvfs.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-int main(int argc, char ** argv) {
-	struct statvfs stat;
-	if (argc != 2) {
-		fprintf(stderr, "Usage: %s PATH", argv[0]);
-		exit(2);
-	}
-	if (statvfs(argv[1], &stat) != 0) {
-		perror("statvfs");
-		exit(3);
-	}
-	if (stat.f_flag & ST_RDONLY)
-		exit(0);
-	else
-		exit(1);
-}
-

nixos/modules/system/boot/stage-2-init.sh

@@ -2,7 +2,22 @@
 
 systemConfig=@systemConfig@
 
-export HOME=/root
+export HOME=/root PATH="@path@"
+
+
+# Process the kernel command line.
+for o in $(</proc/cmdline); do
+    case $o in
+        boot.debugtrace)
+            # Show each command.
+            set -x
+            ;;
+        resume=*)
+            set -- $(IFS==; echo $o)
+            resumeDevice=$2
+            ;;
+    esac
+done
 
 
 # Print a greeting.
@@ -11,21 +26,6 @@ echo -e "\e[1;32m<<< NixOS Stage 2 >>>\e[0m"
 echo
 
 
-# Set the PATH.
-setPath() {
-    local dirs="$1"
-    export PATH=/empty
-    for i in $dirs; do
-        PATH=$PATH:$i/bin
-        if test -e $i/sbin; then
-            PATH=$PATH:$i/sbin
-        fi
-    done
-}
-
-setPath "@path@"
-
-
 # Normally, stage 1 mounts the root filesystem read/writable.
 # However, in some environments, stage 2 is executed directly, and the
 # root is read-only.  So make it writable here.
@@ -61,7 +61,9 @@ echo "booting system configuration $systemConfig" > /dev/kmsg
 chown -f 0:30000 /nix/store
 chmod -f 1775 /nix/store
 if [ -n "@readOnlyStore@" ]; then
-    if ! readonly-mountpoint /nix/store; then
+    if ! [[ "$(findmnt --noheadings --output OPTIONS /nix/store)" =~ ro(,|$) ]]; then
+        # FIXME when linux < 4.5 is EOL, switch to atomic bind mounts
+        #mount /nix/store /nix/store -o bind,remount,ro
         mount --bind /nix/store /nix/store
         mount -o remount,ro,bind /nix/store
     fi
@@ -75,31 +77,12 @@ rm -f /etc/mtab* # not that we care about stale locks
 ln -s /proc/mounts /etc/mtab
 
 
-# Process the kernel command line.
-for o in $(cat /proc/cmdline); do
-    case $o in
-        boot.debugtrace)
-            # Show each command.
-            set -x
-            ;;
-        resume=*)
-            set -- $(IFS==; echo $o)
-            resumeDevice=$2
-            ;;
-    esac
-done
-
-
 # More special file systems, initialise required directories.
 [ -e /proc/bus/usb ] && mount -t usbfs usbfs /proc/bus/usb # UML doesn't have USB by default
 mkdir -m 01777 -p /tmp
-mkdir -m 0755 -p /var /var/log /var/lib /var/db
-mkdir -m 0755 -p /nix/var
-mkdir -m 0700 -p /root
-chmod 0700 /root
-mkdir -m 0755 -p /bin # for the /bin/sh symlink
-mkdir -m 0755 -p /home
-mkdir -m 0755 -p /etc/nixos
+mkdir -m 0755 -p /var/{log,lib,db} /nix/var /etc/nixos/ \
+    /run/lock /home /bin # for the /bin/sh symlink
+install -m 0700 -d /root
 
 
 # Miscellaneous boot time cleanup.
@@ -111,9 +94,6 @@ rm -f /etc/{group,passwd,shadow}.lock
 rm -rf /nix/var/nix/gcroots/tmp /nix/var/nix/temproots
 
 
-mkdir -m 0755 -p /run/lock
-
-
 # For backwards compatibility, symlink /var/run to /run, and /var/lock
 # to /run/lock.
 ln -s /run /var/run
@@ -127,8 +107,8 @@ fi
 
 
 # Use /etc/resolv.conf supplied by systemd-nspawn, if applicable.
-if [ -n "@useHostResolvConf@" -a -e /etc/resolv.conf ]; then
-    cat /etc/resolv.conf | resolvconf -m 1000 -a host
+if [ -n "@useHostResolvConf@" ] && [ -e /etc/resolv.conf ]; then
+    resolvconf -m 1000 -a host </etc/resolv.conf
 fi
 
 # Log the script output to /dev/kmsg or /run/log/stage-2-init.log.

nixos/modules/system/boot/stage-2.nix

@@ -7,15 +7,6 @@ let
   kernel = config.boot.kernelPackages.kernel;
   activateConfiguration = config.system.activationScripts.script;
 
-  readonlyMountpoint = pkgs.stdenv.mkDerivation {
-    name = "readonly-mountpoint";
-    unpackPhase = "true";
-    installPhase = ''
-      mkdir -p $out/bin
-      cc -O3 ${./readonly-mountpoint.c} -o $out/bin/readonly-mountpoint
-    '';
-  };
-
   bootStage2 = pkgs.substituteAll {
     src = ./stage-2-init.sh;
     shellDebug = "${pkgs.bashInteractive}/bin/bash";
@@ -23,11 +14,11 @@ let
     inherit (config.nix) readOnlyStore;
     inherit (config.networking) useHostResolvConf;
     inherit (config.system.build) earlyMountScript;
-    path =
-      [ pkgs.coreutils
-        pkgs.utillinux
-        pkgs.openresolv
-      ] ++ optional config.nix.readOnlyStore readonlyMountpoint;
+    path = lib.makeBinPath [
+      pkgs.coreutils
+      pkgs.utillinux
+      pkgs.openresolv
+    ];
     postBootCommands = pkgs.writeText "local-cmds"
       ''
         ${config.boot.postBootCommands}