Implement snbk snapshot metadata update

diff --git a/client/snbk/BackupConfig.cc b/client/snbk/BackupConfig.cc
index 3cb8e1ee7334b343c97da06d529913a7b0a63edb..5195da1b2280da2caca611391b5ba79f040c5848 100644 (file)
--- a/client/snbk/BackupConfig.cc
+++ b/client/snbk/BackupConfig.cc
@@ -76,6 +76,7 @@ namespace snapper
        get_child_value(json_file.get_root(), "target-mkdir-bin", target_mkdir_bin);
        get_child_value(json_file.get_root(), "target-rm-bin", target_rm_bin);
        get_child_value(json_file.get_root(), "target-rmdir-bin", target_rmdir_bin);
+       get_child_value(json_file.get_root(), "target-sha256sum-bin", target_sha256sum_bin);
     }
 
 

diff --git a/client/snbk/BackupConfig.h b/client/snbk/BackupConfig.h
index 9c573aab0e3cb3cbf686f0469e258743546519c6..f8c390157d763929ad4ca6ab6ed84c29b6230987 100644 (file)
--- a/client/snbk/BackupConfig.h
+++ b/client/snbk/BackupConfig.h
@@ -79,6 +79,7 @@ namespace snapper
        string target_mkdir_bin = MKDIR_BIN;
        string target_rm_bin = RM_BIN;
        string target_rmdir_bin = RMDIR_BIN;
+       string target_sha256sum_bin = SHA256SUM_BIN;
 
     private:
 

diff --git a/client/snbk/CmdFileHash.cc b/client/snbk/CmdFileHash.cc
new file mode 100644 (file)
index 0000000..a857c1b
--- /dev/null
+++ b/client/snbk/CmdFileHash.cc
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2026 SUSE LLC
+ *
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, contact Novell, Inc.
+ *
+ * To contact Novell about this file by physical or electronic mail, you may
+ * find current contact information at www.novell.com.
+ */
+
+
+#include <boost/algorithm/string.hpp>
+
+#include <snapper/Exception.h>
+#include <snapper/LoggerImpl.h>
+#include <snapper/SystemCmd.h>
+
+#include "../utils/text.h"
+
+#include "CmdFileHash.h"
+
+
+namespace snapper
+{
+
+
+    CmdFileHash::CmdFileHash(const Shell& shell, const string& chksum_bin,
+                             const string& path)
+        : path(path)
+    {
+       SystemCmd::Args cmd_args = { chksum_bin, "--", path };
+       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);
+       }
+       else
+       {
+           parse(cmd.get_stdout());
+       }
+
+       y2mil(*this);
+    }
+
+
+    const string& CmdFileHash::get_hash() const { return hash; }
+
+    void CmdFileHash::parse(const vector<string>& lines)
+    {
+       for (const string& line : lines)
+       {
+           vector<string> parts;
+           boost::split(parts, line, boost::is_any_of(" "), boost::token_compress_on);
+           if (parts.size() != 2)
+           {
+               y2err("Invalid hash string: " << line);
+               SN_THROW(Exception(_("Invalid hash output format.")));
+           }
+
+           hash = parts[0];
+           break;
+       }
+    }
+
+
+    std::ostream& operator<<(std::ostream& s, const CmdFileHash& cmd_filehash)
+    {
+       s << "path: " << cmd_filehash.path << " hash: " << cmd_filehash.hash << '\n';
+
+       return s;
+    }
+
+
+} // namespace snapper

diff --git a/client/snbk/CmdFileHash.h b/client/snbk/CmdFileHash.h
new file mode 100644 (file)
index 0000000..8325dbc
--- /dev/null
+++ b/client/snbk/CmdFileHash.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2026 SUSE LLC
+ *
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, contact Novell, Inc.
+ *
+ * To contact Novell about this file by physical or electronic mail, you may
+ * find current contact information at www.novell.com.
+ */
+
+
+#ifndef SNAPPER_CMD_FILE_HASH_H
+#define SNAPPER_CMD_FILE_HASH_H
+
+
+#include "Shell.h"
+
+
+namespace snapper
+{
+    using std::string;
+
+
+    /**
+     * Find the hash of the file at the given path.
+     * If an error occurs, the hash is set to an empty string.
+     */
+    class CmdFileHash
+    {
+    public:
+
+       CmdFileHash(const Shell& shell, const string& chksum_bin, const string& path);
+
+       const string& get_hash() const;
+
+       friend std::ostream& operator<<(std::ostream& s, const CmdFileHash& cmd_filehash);
+
+    private:
+
+       const string path;
+       string hash;
+
+       void parse(const std::vector<string>& lines);
+    };
+
+
+} // namespace snapper
+
+
+#endif

diff --git a/client/snbk/Makefile.am b/client/snbk/Makefile.am
index 42e34c60f7a04e47d9d84aea840e007439bba3a4..91f6dfd875c12cb95d9efc9ee823c23442d62373 100644 (file)
--- a/client/snbk/Makefile.am
+++ b/client/snbk/Makefile.am
@@ -22,6 +22,7 @@ snbk_SOURCES =                                                \
        Shell.cc                Shell.h                 \
        CmdBtrfs.cc             CmdBtrfs.h              \
        CmdLs.cc                CmdLs.h                 \
+       CmdFileHash.cc          CmdFileHash.h           \
        JsonFile.cc             JsonFile.h              \
        utils.cc                utils.h                 \
        TreeView.cc             TreeView.h

diff --git a/client/snbk/TheBigThing.cc b/client/snbk/TheBigThing.cc
index dcec671ab790929e483c066e436d4691b3bf7bfe..812cf807b233e98fcc72be2cf4f25146add6a2fb 100644 (file)
--- a/client/snbk/TheBigThing.cc
+++ b/client/snbk/TheBigThing.cc
@@ -34,6 +34,7 @@
 
 #include "CmdBtrfs.h"
 #include "CmdLs.h"
+#include "CmdFileHash.h"
 #include "BackupConfig.h"
 #include "TheBigThing.h"
 
@@ -57,7 +58,8 @@ namespace snapper
            bool is_valid() const override
            {
                return it->source_state == TheBigThing::SourceState::READ_ONLY &&
-                      it->target_state == TheBigThing::TargetState::VALID;
+                      (it->target_state == TheBigThing::TargetState::VALID ||
+                       it->target_state == TheBigThing::TargetState::LEGACY);
            }
 
        protected:
@@ -129,7 +131,7 @@ namespace snapper
 
 
     const vector<string> EnumInfo<TheBigThing::TargetState>::names({
-       "missing", "valid", "invalid"
+       "missing", "valid", "invalid", "legacy"
     });
 
 
@@ -156,53 +158,8 @@ namespace snapper
            SN_THROW(Exception(_("'mkdir' failed.")));
        }
 
-       // Copy info.xml to the destination.
-       switch (backup_config.target_mode)
-       {
-           case BackupConfig::TargetMode::LOCAL:
-           {
-               SystemCmd::Args cmd2_args = { CP_BIN, "--",
-                                             src_spec.snapshot_dir + "/info.xml",
-                                             dst_spec.snapshot_dir + "/" };
-               SystemCmd cmd2(shellify(src_spec.shell, cmd2_args));
-               if (cmd2.retcode() != 0)
-               {
-                   y2err("command '" << cmd2.cmd() << "' failed: " << cmd2.retcode());
-                   for (const string& tmp : cmd2.get_stdout())
-                       y2err(tmp);
-                   for (const string& tmp : cmd2.get_stderr())
-                       y2err(tmp);
-
-                   SN_THROW(Exception(_("'cp info.xml' failed.")));
-               }
-           }
-           break;
-
-           case BackupConfig::TargetMode::SSH_PUSH:
-           {
-               SystemCmd::Args cmd2_args = { SCP_BIN };
-               if (backup_config.ssh_port != 0)
-                   cmd2_args << "-P" << to_string(backup_config.ssh_port);
-               if (!backup_config.ssh_identity.empty())
-                   cmd2_args << "-i" << backup_config.ssh_identity;
-               cmd2_args << "--"
-                         << src_spec.remote_host + src_spec.snapshot_dir + "/info.xml"
-                         << dst_spec.remote_host + dst_spec.snapshot_dir + "/";
-
-               SystemCmd cmd2(cmd2_args);
-               if (cmd2.retcode() != 0)
-               {
-                   y2err("command '" << cmd2.cmd() << "' failed: " << cmd2.retcode());
-                   for (const string& tmp : cmd2.get_stdout())
-                       y2err(tmp);
-                   for (const string& tmp : cmd2.get_stderr())
-                       y2err(tmp);
-
-                   SN_THROW(Exception(_("'scp info.xml' failed.")));
-               }
-           }
-           break;
-       };
+       // Copy snapshot metadata to the destination
+       copy_metadata(backup_config, the_big_things, copy_specs);
 
        // Copy snapshot to the destination.
        const int proto = the_big_things.proto();
@@ -242,24 +199,97 @@ namespace snapper
     }
 
 
+    void
+    TheBigThing::copy_metadata(const BackupConfig& backup_config,
+                               TheBigThings& the_big_things,
+                               const pair<CopySpec, CopySpec>& copy_specs)
+    {
+       // Unpack copy specification
+       const CopySpec& src_spec = copy_specs.first;
+       const CopySpec& dst_spec = copy_specs.second;
+
+       // Copy info.xml to the destination.
+       switch (backup_config.target_mode)
+       {
+           case BackupConfig::TargetMode::LOCAL:
+           {
+               SystemCmd::Args cmd_args = { CP_BIN, "--",
+                                            src_spec.snapshot_dir + "/info.xml",
+                                            dst_spec.snapshot_dir + "/" };
+               SystemCmd cmd(shellify(src_spec.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(_("'cp info.xml' failed.")));
+               }
+           }
+           break;
+
+           case BackupConfig::TargetMode::SSH_PUSH:
+           {
+               SystemCmd::Args cmd_args = { SCP_BIN };
+               if (backup_config.ssh_port != 0)
+                   cmd_args << "-P" << to_string(backup_config.ssh_port);
+               if (!backup_config.ssh_identity.empty())
+                   cmd_args << "-i" << backup_config.ssh_identity;
+               cmd_args << "--"
+                        << src_spec.remote_host + src_spec.snapshot_dir + "/info.xml"
+                        << dst_spec.remote_host + dst_spec.snapshot_dir + "/";
+
+               SystemCmd cmd(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(_("'scp info.xml' failed.")));
+               }
+           }
+           break;
+       };
+    }
+
+
     void
     TheBigThing::transfer(const BackupConfig& backup_config, TheBigThings& the_big_things,
                          bool quiet)
     {
-       if (!quiet)
-           cout << sformat(_("Transferring snapshot %d."), num) << '\n';
-
        if (source_state == SourceState::MISSING)
            SN_THROW(Exception(_("Snapshot not on source.")));
        else if (source_state == SourceState::READ_WRITE)
            SN_THROW(Exception(_("Cannot transfer a read-write snapshot.")));
 
-       if (target_state != TargetState::MISSING)
-           SN_THROW(Exception(_("Snapshot already on target.")));
-
-       // Copy the snapshot from the source to the target
-       copy(backup_config, the_big_things,
-            make_copy_specs(backup_config, the_big_things, CopyMode::SOURCE_TO_TARGET));
+       auto copy_specs =
+           make_copy_specs(backup_config, the_big_things, CopyMode::SOURCE_TO_TARGET);
+       switch (target_state)
+       {
+           case TargetState::INVALID:
+           case TargetState::VALID:
+               SN_THROW(Exception(_("Snapshot already on target.")));
+               __builtin_unreachable();
+
+           case TargetState::MISSING:
+               // Copy the snapshot from the source to the target
+               if (!quiet)
+                   cout << sformat(_("Transferring snapshot %d."), num) << '\n';
+               copy(backup_config, the_big_things, copy_specs);
+               break;
+
+           case TargetState::LEGACY:
+               // Overwrite the snapshot metadata on the target
+               if (!quiet)
+                   cout << sformat(_("Updating metadata of snapshot %d."), num) << '\n';
+               copy_metadata(backup_config, the_big_things, copy_specs);
+               break;
+       }
 
        target_state = TargetState::VALID;
     }
@@ -486,6 +516,11 @@ namespace snapper
            the_big_thing.source_received_uuid = extra.get_received_uuid();
            the_big_thing.source_creation_time = extra.get_creation_time();
 
+           // Find the hash of info.xml
+           CmdFileHash cmd_filehash(shell_source, SHA256SUM_BIN,
+                                    source_snapshot_dir(snapper, num) + "/info.xml");
+           the_big_thing.source_meta_hash = cmd_filehash.get_hash();
+
            the_big_things.push_back(the_big_thing);
        }
     }
@@ -581,6 +616,19 @@ namespace snapper
                it->target_parent_uuid = extra.get_parent_uuid();
                it->target_received_uuid = extra.get_received_uuid();
                it->target_creation_time = extra.get_creation_time();
+
+               // Find the hash of info.xml
+               CmdFileHash cmd_filehash(shell_target, backup_config.target_sha256sum_bin,
+                                        target_snapshot_dir(backup_config, num) +
+                                            "/info.xml");
+               it->target_meta_hash = cmd_filehash.get_hash();
+
+               if (it->source_state == TheBigThing::SourceState::READ_ONLY &&
+                   it->target_state == TheBigThing::TargetState::VALID &&
+                   it->source_meta_hash != it->target_meta_hash)
+               {
+                   it->target_state = TheBigThing::TargetState::LEGACY;
+               }
            }
            catch (const Exception& e)
            {
@@ -605,7 +653,8 @@ namespace snapper
                    the_big_thing.remove(backup_config, quiet);
                }
 
-               if (the_big_thing.target_state == TheBigThing::TargetState::MISSING)
+               if (the_big_thing.target_state == TheBigThing::TargetState::MISSING ||
+                   the_big_thing.target_state == TheBigThing::TargetState::LEGACY)
                {
                    the_big_thing.transfer(backup_config, *this, quiet);
                }

diff --git a/client/snbk/TheBigThing.h b/client/snbk/TheBigThing.h
index 7901467eaebed79d9a5330d4faa1c54e0d728a7d..b42eb809c2de5a4c2e66c80b82fb3336da0d994b 100644 (file)
--- a/client/snbk/TheBigThing.h
+++ b/client/snbk/TheBigThing.h
@@ -53,7 +53,18 @@ namespace snapper
        // snapshots on target are always read-only if valid
 
        enum class SourceState { MISSING, READ_ONLY, READ_WRITE };
-       enum class TargetState { MISSING, VALID, INVALID };
+       enum class TargetState
+       {
+           MISSING,
+           VALID,
+           INVALID,
+
+           /**
+            * Indicates that the snapshot has been transferred to the target, but the
+            * source snapshot's metadata has changed since the transfer.
+            */
+           LEGACY
+       };
 
        TheBigThing(unsigned int num) : num(num) {}
 
@@ -72,11 +83,13 @@ namespace snapper
        string source_parent_uuid;
        string source_received_uuid;
        string source_creation_time;
+       string source_meta_hash;
 
        string target_uuid;
        string target_parent_uuid;
        string target_received_uuid;
        string target_creation_time;
+       string target_meta_hash;
 
     private:
 
@@ -116,6 +129,9 @@ namespace snapper
 
        void copy(const BackupConfig& backup_config, TheBigThings& the_big_things,
                  const pair<CopySpec, CopySpec>& copy_specs);
+       void copy_metadata(const BackupConfig& backup_config,
+                          TheBigThings& the_big_things,
+                          const pair<CopySpec, CopySpec>& copy_specs);
 
     };
 

diff --git a/configure.ac b/configure.ac
index d999faa0cb6d1bb2ebcb7f9bde6d4a90c066aee8..f15bf28ed908272905c07b0a24e20c6fc069bc64 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -41,6 +41,7 @@ AC_PATH_PROG([LVS_BIN], [lvs], [/sbin/lvs])
 AC_PATH_PROG([MKDIR_BIN], [mkdir], [/bin/mkdir])
 AC_PATH_PROG([RM_BIN], [rm], [/bin/rm])
 AC_PATH_PROG([RMDIR_BIN], [rmdir], [/bin/rmdir])
+AC_PATH_PROG([SHA256SUM_BIN], [sha256sum], [/usr/bin/sha256sum])
 AC_PATH_PROG([TOUCH_BIN], [touch], [/usr/bin/touch])
 
 AC_DEFINE_UNQUOTED([BTRFS_BIN], ["$BTRFS_BIN"], [Path of btrfs program.])
@@ -58,6 +59,7 @@ AC_DEFINE_UNQUOTED([LVS_BIN], ["$LVS_BIN"], [Path of lvs program.])
 AC_DEFINE_UNQUOTED([MKDIR_BIN], ["$MKDIR_BIN"], [Path of mkdir program.])
 AC_DEFINE_UNQUOTED([RM_BIN], ["$RM_BIN"], [Path of rm program.])
 AC_DEFINE_UNQUOTED([RMDIR_BIN], ["$RMDIR_BIN"], [Path of rmdir program.])
+AC_DEFINE_UNQUOTED([SHA256SUM_BIN], ["$SHA256SUM_BIN"], [Path of sha256sum program.])
 AC_DEFINE_UNQUOTED([TOUCH_BIN], ["$TOUCH_BIN"], [Path of touch program.])
 
 CFLAGS="${CFLAGS} -std=c99 -Wall -Wextra -Wformat -Wmissing-prototypes -Wno-unused-parameter"

diff --git a/doc/snbk.xml.in b/doc/snbk.xml.in
index 1b95061351c10c26e287f91ebea7a3a6933732bc..93c632883a5e422d20d8e9d0bc2977741d862496 100644 (file)
--- a/doc/snbk.xml.in
+++ b/doc/snbk.xml.in
@@ -103,6 +103,14 @@
            transfer the snapshot again.</para>
           </glossdef>
         </glossentry>
+       <glossentry>
+         <glossterm>legacy</glossterm>
+         <glossdef>
+           <para>The snapshot is valid, but the source snapshot's metadata has changed
+           since the transfer. The next transfer command will update the snapshot's
+           metadata on the target.</para>
+         </glossdef>
+       </glossentry>
       </glosslist>
     </refsect2>