- support sending compressed data in snbk

client/snbk/BackupConfig.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024 SUSE LLC
+ * Copyright (c) [2024-2025] SUSE LLC
  *
  * All Rights Reserved.
  *
@@ -70,6 +70,10 @@ namespace snapper
 	    get_child_value(json_file.get_root(), "ssh-identity", ssh_identity);
 	}
 
+	get_child_value(json_file.get_root(), "send-compressed-data", send_compressed_data);
+	get_child_nodes(json_file.get_root(), "send-options", send_options);
+	get_child_nodes(json_file.get_root(), "receive-options", receive_options);
+
 	get_child_value(json_file.get_root(), "target-btrfs-bin", target_btrfs_bin);
 	get_child_value(json_file.get_root(), "target-findmnt-bin", target_findmnt_bin);
 	get_child_value(json_file.get_root(), "target-mkdir-bin", target_mkdir_bin);

client/snbk/BackupConfig.h

@@ -70,6 +70,10 @@ namespace snapper
 	Shell get_source_shell() const;
 	Shell get_target_shell() const;
 
+	bool send_compressed_data = true;
+	vector<string> send_options;
+	vector<string> receive_options;
+
 	string target_btrfs_bin = BTRFS_BIN;
 	string target_findmnt_bin = FINDMNT_BIN;
 	string target_mkdir_bin = MKDIR_BIN;

client/snbk/CmdBtrfs.cc

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) [2004-2015] Novell, Inc.
- * Copyright (c) [2017-2024] SUSE LLC
+ * Copyright (c) [2017-2025] SUSE LLC
  *
  * All Rights Reserved.
  *
@@ -21,6 +21,7 @@
  */
 
 
+#include <sys/utsname.h>
 #include <cstring>
 #include <regex>
 #include <boost/algorithm/string.hpp>
@@ -259,4 +260,88 @@ namespace snapper
 	return s;
     }
 
+
+    void
+    CmdBtrfsVersion::query_version()
+    {
+	if (did_set_version)
+	    return;
+
+	SystemCmd::Args cmd_args = { btrfs_bin, "--version" };
+	SystemCmd cmd(shellify(shell, cmd_args));
+
+	if (cmd.retcode() != 0)
+	{
+	    y2err("command '" << cmd.cmd() << "' failed: " << cmd.retcode());
+	    for (const string& tmp : cmd.get_stdout())
+		y2err(tmp);
+	    for (const string& tmp : cmd.get_stderr())
+		y2err(tmp);
+
+	    SN_THROW(Exception("'btrfs --version' failed"));
+	}
+
+	parse_version(cmd.get_stdout()[0]);
+    }
+
+
+    void
+    CmdBtrfsVersion::parse_version(const string& version)
+    {
+	// example versions: "5.14 " (yes, with a trailing space), "6.0", "6.0.2"
+	const regex version_rx("btrfs-progs v([0-9]+)\\.([0-9]+)(\\.([0-9]+))?( )*", regex::extended);
+
+	smatch match;
+
+	if (!regex_match(version, match, version_rx))
+	    SN_THROW(Exception("failed to parse btrfs version '" + version + "'"));
+
+	major = stoi(match[1]);
+	minor = stoi(match[2]);
+	patchlevel = match[4].length() == 0 ? 0 : stoi(match[4]);
+
+	y2mil("major:" << major << " minor:" << minor << " patchlevel:" << patchlevel);
+
+	did_set_version = true;
+    }
+
+
+    int
+    CmdBtrfsVersion::supported_proto()
+    {
+	query_version();
+
+	if (major >= 6)
+	    return 2;
+
+	return 1;
+    }
+
+
+    int
+    Uname::supported_proto()
+    {
+	const regex release_rx("^([0-9]+)\\.([0-9]+).*", regex::extended);
+
+	struct utsname buffer;
+
+	if (uname(&buffer) < 0)
+	    SN_THROW(Exception("syscall uname failed"));
+
+	cmatch match;
+
+	if (!regex_match(buffer.release, match, release_rx))
+	    SN_THROW(Exception("failed to parse uname release '" + string(buffer.release) + "'"));
+
+	int major = stoi(match[1]);
+	int minor = stoi(match[2]);
+
+	y2mil("major:" << major << " minor:" << minor);
+
+	if (major >= 6)
+	    return 2;
+
+	return 1;
+    }
+
 }

client/snbk/CmdBtrfs.h

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) [2004-2015] Novell, Inc.
- * Copyright (c) [2017-2024] SUSE LLC
+ * Copyright (c) [2017-2025] SUSE LLC
  *
  * All Rights Reserved.
  *
@@ -116,6 +116,45 @@ namespace snapper
 
     };
 
+
+    /**
+     * Lazy query of btrfs command version.
+     */
+    class CmdBtrfsVersion
+    {
+    public:
+
+	CmdBtrfsVersion(const string& btrfs_bin, const Shell& shell)
+	    : btrfs_bin(btrfs_bin), shell(shell)
+	{}
+
+	int supported_proto();
+
+    private:
+
+	void query_version();
+	void parse_version(const string& version);
+
+	const string btrfs_bin;
+	const Shell shell;
+
+	bool did_set_version = false;
+
+	int major = 0;
+	int minor = 0;
+	int patchlevel = 0;
+
+    };
+
+
+    class Uname
+    {
+    public:
+
+	static int supported_proto();
+
+    };
+
 }
 
 #endif

client/snbk/JsonFile.cc

@@ -20,7 +20,7 @@
  */
 
 
-#include <stdio.h>
+#include <cstdio>
 #include <sys/stat.h>
 #include <functional>
 #include <memory>
@@ -187,6 +187,28 @@ namespace snapper
     }
 
 
+    bool
+    get_child_nodes(json_object* parent, const char* name, vector<string>& values)
+    {
+	vector<json_object*> children;
+
+	if (!get_child_nodes(parent, name, children))
+	    return false;
+
+	values.clear();
+
+	for (json_object* child : children)
+	{
+	    if (!json_object_is_type(child, json_type_string))
+		return false;
+
+	    values.push_back(json_object_get_string(child));
+	}
+
+	return true;
+    }
+
+
     bool
     get_child_nodes(json_object* parent, const char* name, vector<json_object*>& children)
     {

client/snbk/JsonFile.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) [2017-2024] SUSE LLC
+ * Copyright (c) [2017-2025] SUSE LLC
  *
  * All Rights Reserved.
  *
@@ -68,6 +68,9 @@ namespace snapper
     get_child_value(json_object* parent, const char* name, Type& value);
 
 
+    bool
+    get_child_nodes(json_object* parent, const char* name, vector<string>& values);
+
     bool
     get_child_nodes(json_object* parent, const char* name, vector<json_object*>& children);
 

client/snbk/TheBigThing.cc

@@ -57,7 +57,7 @@ namespace snapper
 
 
     void
-    TheBigThing::transfer(const BackupConfig& backup_config, const TheBigThings& the_big_things,
+    TheBigThing::transfer(const BackupConfig& backup_config, TheBigThings& the_big_things,
 			  bool quiet)
     {
 	if (!quiet)
@@ -137,16 +137,29 @@ namespace snapper
 
 	// Copy snapshot to target.
 
+	const int proto = std::min({
+	    Uname::supported_proto(),
+	    the_big_things.source_btrfs_version.supported_proto(),
+	    the_big_things.target_btrfs_version.supported_proto()
+	});
+
 	TheBigThings::const_iterator it1 = the_big_things.find_send_parent(*this);
 
 	SystemCmd::Args cmd3a_args = { BTRFS_BIN, "send" };
+	if (proto >= 2)
+	    cmd3a_args << "--proto" << to_string(proto);
+	if (backup_config.send_compressed_data && proto >= 2)
+	    cmd3a_args << "--compressed-data";
+	cmd3a_args << backup_config.send_options;
+
 	if (it1 != the_big_things.end())
 	    cmd3a_args << "-p" << backup_config.source_path + "/" SNAPSHOTS_NAME "/" +
 		to_string(it1->num) + "/" SNAPSHOT_NAME;
 	cmd3a_args << "--" << backup_config.source_path + "/" SNAPSHOTS_NAME "/" + num_string + "/" SNAPSHOT_NAME;
 
-	SystemCmd::Args cmd3b_args = { backup_config.target_btrfs_bin, "receive", "--",
-	    backup_config.target_path + "/" + num_string };
+	SystemCmd::Args cmd3b_args = { backup_config.target_btrfs_bin, "receive" };
+	cmd3b_args << backup_config.receive_options;
+	cmd3b_args << "--" << backup_config.target_path + "/" + num_string;
 
 	y2deb("source: " << cmd3a_args.get_values());
 	y2deb("target: " << cmd3b_args.get_values());
@@ -238,7 +251,9 @@ namespace snapper
 
 
     TheBigThings::TheBigThings(const BackupConfig& backup_config, ProxySnappers* snappers, bool verbose)
-	: snapper(snappers->getSnapper(backup_config.config)), locker(snapper)
+	: source_btrfs_version(BTRFS_BIN, backup_config.get_source_shell()),
+	  target_btrfs_version(backup_config.target_btrfs_bin, backup_config.get_target_shell()),
+	  snapper(snappers->getSnapper(backup_config.config)), locker(snapper)
     {
 	if (backup_config.source_path != snapper->getConfig().getSubvolume())
 	{

client/snbk/TheBigThing.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024 SUSE LLC
+ * Copyright (c) [2024-2025] SUSE LLC
  *
  * All Rights Reserved.
  *
@@ -29,6 +29,8 @@
 #include "../proxy/proxy.h"
 #include "../proxy/locker.h"
 
+#include "CmdBtrfs.h"
+
 
 namespace snapper
 {
@@ -52,7 +54,7 @@ namespace snapper
 
 	TheBigThing(unsigned int num) : num(num) {}
 
-	void transfer(const BackupConfig& backup_config, const TheBigThings& the_big_things, bool quiet);
+	void transfer(const BackupConfig& backup_config, TheBigThings& the_big_things, bool quiet);
 
 	void remove(const BackupConfig& backup_config, bool quiet);
 
@@ -110,6 +112,9 @@ namespace snapper
 	 */
 	const_iterator find_send_parent(const TheBigThing& the_big_thing) const;
 
+	CmdBtrfsVersion source_btrfs_version;
+	CmdBtrfsVersion target_btrfs_version;
+
     private:
 
 	const ProxySnapper* snapper;

doc/snapper-backup-configs.xml.in

@@ -2,13 +2,13 @@
 <refentry id='snapper-backup-configs5'>
 
   <refentryinfo>
-    <date>2025-04-09</date>
+    <date>2025-10-07</date>
   </refentryinfo>
 
   <refmeta>
     <refentrytitle>snapper-backup-configs</refentrytitle>
     <manvolnum>5</manvolnum>
-    <refmiscinfo class='date'>2025-04-09</refmiscinfo>
+    <refmiscinfo class='date'>2025-10-07</refmiscinfo>
     <refmiscinfo class='version'>@VERSION@</refmiscinfo>
     <refmiscinfo class='manual'>Filesystem Snapshot Management</refmiscinfo>
   </refmeta>
@@ -102,6 +102,33 @@
 	</listitem>
       </varlistentry>
 
+      <varlistentry>
+	<term><option>send-compressed-data</option></term>
+	<listitem>
+	  <para>Per default snbk will add the option --compressed-data iff
+	  supported by the source and target system. This can be disable by
+	  setting this value to false.</para>
+	</listitem>
+      </varlistentry>
+
+      <varlistentry>
+	<term><option>send-options</option></term>
+	<listitem>
+	  <para>Extra options for the btrfs send command as an array
+	  of strings. Optional.</para>
+	  <para>Per default snbk automatically adds --proto and --compressed-data
+	  iff supported by both the source and target.</para>
+	</listitem>
+      </varlistentry>
+
+      <varlistentry>
+	<term><option>receive-options</option></term>
+	<listitem>
+	  <para>Extra options for the btrfs receive command as an
+	  array of strings. Optional.</para>
+	</listitem>
+      </varlistentry>
+
       <varlistentry>
 	<term><option>target-btrfs-bin</option></term>
 	<listitem>

package/snapper.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue Oct 07 14:42:16 CEST 2025 - aschnell@suse.com
+
+- support sending compressed data in snbk
+  (gh#openSUSE/snapper#1059)
+
 -------------------------------------------------------------------
 Wed Sep 24 16:12:34 CEST 2025 - aschnell@suse.com
 

scripts/snbk-btrfs

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+if [ "$#" -eq 1 ] && [ "$1" == "--version" ]; then
+    exec sudo /usr/sbin/btrfs --version
+fi
+
 if [ "$#" -lt 3 ]; then
     echo "Usage: $0 <group> [subcommand] [options] -- /backup/..."
     exit 1