From 26de022b5655b47a427ab325673e1cb1cb54d524 Mon Sep 17 00:00:00 2001
From: Thomas Lamprecht <t.lamprecht@proxmox.com>
Date: Fri, 19 Feb 2021 15:21:16 +0100
Subject: [PATCH] zpool: activate: move mount check out and make program flow
 easier

Early return when mounted heuristics returns true, that allows to get
rid of an indentation level.

Moving the heuristic out makes the activate method smaller and easier
to grasp

Best viewed with ignoring whitespace changes (`git show -w`).

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
---
 PVE/Storage/ZFSPoolPlugin.pm | 49 ++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 24 deletions(-)

diff --git a/PVE/Storage/ZFSPoolPlugin.pm b/PVE/Storage/ZFSPoolPlugin.pm
index c734429..fe65ae4 100644
--- a/PVE/Storage/ZFSPoolPlugin.pm
+++ b/PVE/Storage/ZFSPoolPlugin.pm
@@ -522,6 +522,21 @@ sub volume_snapshot_list {
     return $snaps;
 }
 
+my sub dataset_mounted_heuristic {
+    my ($dataset) = @_;
+
+    my $mounts = PVE::ProcFSTools::parse_proc_mounts();
+    for my $mp (@$mounts) {
+	my ($what, $dir, $fs) = $mp->@*;
+	next if $fs ne 'zfs';
+	# check for root-dataset or any child-dataset (root-dataset could have 'canmount=off')
+	# If any child is mounted heuristically assume that `zfs mount -a` was successful
+	next if $what !~ m!^$dataset(?:/|$)!;
+	return 1;
+    }
+    return 0;
+}
+
 sub activate_storage {
     my ($class, $storeid, $scfg, $cache) = @_;
 
@@ -529,19 +544,7 @@ sub activate_storage {
     my $dataset = $scfg->{pool};
     my $pool = ($dataset =~ s!/.*$!!r);
 
-    my $dataset_mounted = sub {
-	my $mounts = PVE::ProcFSTools::parse_proc_mounts();
-	foreach my $mp (@$mounts) {
-	    my ($what, $dir, $fs) = @$mp;
-	    next if $fs ne 'zfs';
-	    # check for root-dataset of storage or any child-dataset.
-	    # root-dataset could have 'canmount=off'. If any child is mounted
-	    # heuristically assume that `zfs mount -a` was successful
-	    next if $what !~ m!^$dataset(?:/|$)!;
-	    return 1;
-	}
-	return 0;
-    };
+    return 1 if dataset_mounted_heuristic($dataset); # early return
 
     my $pool_imported = sub {
 	my @param = ('-o', 'name', '-H', $pool);
@@ -551,19 +554,17 @@ sub activate_storage {
 	return defined($res) && $res =~ m/$pool/;
     };
 
-    if (!$dataset_mounted->()) {
-	if (!$pool_imported->()) {
-	    # import can only be done if not yet imported!
-	    my @param = ('-d', '/dev/disk/by-id/', '-o', 'cachefile=none', $pool);
-	    eval { $class->zfs_request($scfg, undef, 'zpool_import', @param) };
-	    if (my $err = $@) {
-		# just could've raced with another import, so recheck if it is imported
-		die "could not activate storage '$storeid', $err\n" if !$pool_imported->();
-	    }
+    if (!$pool_imported->()) {
+	# import can only be done if not yet imported!
+	my @param = ('-d', '/dev/disk/by-id/', '-o', 'cachefile=none', $pool);
+	eval { $class->zfs_request($scfg, undef, 'zpool_import', @param) };
+	if (my $err = $@) {
+	    # just could've raced with another import, so recheck if it is imported
+	    die "could not activate storage '$storeid', $err\n" if !$pool_imported->();
 	}
-	eval { $class->zfs_request($scfg, undef, 'mount', '-a') };
-	die "could not activate storage '$storeid', $@\n" if $@;
     }
+    eval { $class->zfs_request($scfg, undef, 'mount', '-a') };
+    die "could not activate storage '$storeid', $@\n" if $@;
     return 1;
 }