nixos: Fix detection of btrfs root volume

Regression introduced by 801c920. Since then, the btrfsSimple subtest of the installer VM test fails with: Btrfs did not return a path for the subvolume at / The reason for this is that the output for "btrfs subvol show" has changed between version 4.8.2 and 4.13.1. For example the output of "btrfs subvol show /" in version 4.8.2 was: / is toplevel subvolume In version 4.13.1, the output now is the following and thus the regular expressions used in nixos-generate-config.pl and install-grub.pl now match (which results in the error mentioned above): / Name: <FS_TREE> UUID: - Parent UUID: - Received UUID: - Creation time: - Subvolume ID: 5 Generation: 287270 Gen at creation: 0 Parent ID: 0 Top level ID: 0 Flags: - Snapshot(s): In order to fix this I've changed nixos-generate-config.pl and install-grub.pl, because both use "btrfs subvol show" in a similar vein, so the regex for parsing the output now doesn't match anymore whenever the volume path is "/", which should result in the same behaviour as we had with btrfs-progs version 4.8.2. Tested against the btrfsSimple, btrfsSubvols and btrfsSubvolDefault subtests of the installer VM test and they all succeed now. Signed-off-by: aszlig <aszlig@redmoonstudios.org>
NixOS · Oct 11, 2017 · f4e7425 · f4e7425
1 parent d1e1ee7
commit f4e7425
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diff --git a/nixos/modules/installer/tools/nixos-generate-config.pl b/nixos/modules/installer/tools/nixos-generate-config.pl
@@ -402,7 +402,7 @@ sub in {
         if ($status != 0 || join("", @info) =~ /ERROR:/) {
             die "Failed to retrieve subvolume info for $mountPoint\n";
         }
-        my @ids = join("", @info) =~ m/Subvolume ID:[ \t\n]*([0-9]*)/;
+        my @ids = join("\n", @info) =~ m/^(?!\/\n).*Subvolume ID:[ \t\n]*([0-9]+)/s;
         if ($#ids > 0) {
             die "Btrfs subvol name for $mountPoint listed multiple times in mount\n"
         } elsif ($#ids == 0) {

diff --git a/nixos/modules/system/boot/loader/grub/install-grub.pl b/nixos/modules/system/boot/loader/grub/install-grub.pl
@@ -197,7 +197,7 @@ sub GrubFs {
                 if ($status != 0) {
                     die "Failed to retrieve subvolume info for @{[$fs->mount]}\n";
                 }
-                my @ids = join("", @id_info) =~ m/Subvolume ID:[ \t\n]*([^ \t\n]*)/;
+                my @ids = join("\n", @id_info) =~ m/^(?!\/\n).*Subvolume ID:[ \t\n]*([0-9]+)/s;
                 if ($#ids > 0) {
                     die "Btrfs subvol name for @{[$fs->device]} listed multiple times in mount\n"
                 } elsif ($#ids == 0) {