From 17957a163a16836c3539cc1ef2830a2c5cc0e2d1 Mon Sep 17 00:00:00 2001
From: Axel Burri <axel@tty0.ch>
Date: Fri, 4 Jan 2019 17:32:01 +0100
Subject: [PATCH] btrbk: trigger autofs mount while resolving mountpoints

If resolved mount point has fs_type=autofs, trigger automount by
calling "btrfs subvolume show" on the mount point, and check mountinfo
again.
---
 ChangeLog |  1 +
 btrbk     | 17 +++++++++++++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 22407e6..6581c74 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 btrbk-master
 
   * Bump dependency >= btrfs-progs-4.12 (as of btrbk-0.27.0).
+  * Trigger autofs mount while resolving mountpoints (close #259).
 
 btrbk-0.27.1
 
diff --git a/btrbk b/btrbk
index 30023da..b4acb95 100755
--- a/btrbk
+++ b/btrbk
@@ -1847,9 +1847,10 @@ sub system_mkdir($)
 }
 
 
-sub btrfs_mountpoint($)
+sub btrfs_mountpoint
 {
   my $vol = shift // die;
+  my $autofs_retry = shift;
 
   DEBUG "Resolving btrfs mount point for: $vol->{PRINT}";
 
@@ -1891,7 +1892,19 @@ sub btrfs_mountpoint($)
     return undef;
   }
   TRACE "resolved mount point (mount_source=$mountpoint->{mount_source}, subvolid=" . ($mountpoint->{MNTOPS}->{subvolid} // '<undef>') . "): $mountpoint->{mount_point}";
-  unless($mountpoint->{fs_type} eq 'btrfs') {
+
+  # handle autofs
+  if($mountpoint->{fs_type} eq 'autofs') {
+    if($autofs_retry) {
+      DEBUG "non-btrfs autofs mount point for: $vol->{PRINT}";
+      return undef;
+    }
+    DEBUG "autofs mount point found, triggering automount on $mountpoint->{mount_point} for: $vol->{PRINT}";
+    btrfs_subvolume_show(vinfo($vol->{URL_PREFIX} . $mountpoint->{mount_point}, $vol->{CONFIG}));
+    $mountinfo_cache{$host} = undef;
+    return btrfs_mountpoint($vol, 1);
+  }
+  elsif($mountpoint->{fs_type} ne 'btrfs') {
     DEBUG "No btrfs mount point found for: $vol->{PRINT}";
     return undef;
   }