From a9267a4ec624df9cb95918def9c42f76b44de474 Mon Sep 17 00:00:00 2001
From: Stefan Schantl <stefan.schantl@ipfire.org>
Date: Sun, 5 May 2024 16:54:06 +0200
Subject: [PATCH] filesystem-functions.pl: Add btrfs_subvolume_snapshot()
 function

Function which calls the btrfs binary to create a snapshot.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>
---
 config/cfgroot/filesystem-functions.pl | 33 ++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/config/cfgroot/filesystem-functions.pl b/config/cfgroot/filesystem-functions.pl
index 02c2e146f..d48cbe1f6 100644
--- a/config/cfgroot/filesystem-functions.pl
+++ b/config/cfgroot/filesystem-functions.pl
@@ -37,6 +37,9 @@ my $uuid_dir = "/dev/disk/by-uuid";
 # Location where the btrfs binary lives.
 my $btrfs_bin = "/usr/bin/btrfs";
 
+# Directory where BTRFS snapshots will be stored.
+my $btrfs_snapshot_dir = "/.snapshots/";
+
 #
 ## Function which returns a lot of details about the known devices
 ## as a hash of hashes.
@@ -581,4 +584,34 @@ sub btrfs_subvolume_list ($) {
 	return @output;
 }
 
+#
+## Function which calls the subvolume snapshot feature of the btrfs tool to create a snapshot.
+##
+## Possible argument:
+##	name: The name of the snapshot
+##	source: If it is different than "/"
+##	target: If it is different than the defined "$btrfs_snapshot_dir"
+#
+sub btrfs_subvolume_snapshot ($$$) {
+	my ($name, $source, $target) = @_;
+
+	# Default to "/" if no source has been given.
+	$source //= "/";
+
+	# Default to snapshot dir if no target has been specified.
+	$target //= "$btrfs_snapshot_dir";
+
+	# Generate destination path.
+	my $destination = "$target" . "$name";
+
+	# Call the btrfs binary to create the snapshot.
+	my $ret = &General::system("$btrfs_bin", "subvolume", "snapshot", "$source", "$destination");
+
+	# Return the error code if there was one.
+	return $ret if($ret);
+
+	# Return nothing on success.
+	return;
+}
+
 1;
-- 
2.39.5