feat: add Ceph RBD support;add RAW image checksum support

libvirtnbdbackup/backup/disk.py

@@ -31,6 +31,9 @@
 from libvirtnbdbackup.backup import server
 from libvirtnbdbackup.backup import target
 from libvirtnbdbackup.backup.metadata import backupChecksum
+from libvirtnbdbackup.backup.metadata import adler32_full_file
+from libvirtnbdbackup.backup.metadata import write_checksum_sidecar
+from libvirtnbdbackup.backup.metadata import _fsync_file
 from libvirtnbdbackup import extenthandler
 from libvirtnbdbackup.qemu import util as qemu
 from libvirtnbdbackup.qemu.exceptions import ProcessError
@@ -208,24 +211,33 @@ def backup(  # pylint: disable=too-many-arguments,too-many-branches, too-many-lo
         if args.compress:
             dStream.writeCompressionTrailer(writer, compressedSizes)
 
-    progressBar.close()
+        progressBar.close()
     writer.close()
     connection.disconnect()
 
     if args.offline is True and virtClient.remoteHost == "":
         logging.info("Stopping NBD Service.")
         lib.killProc(nbdProc.pid)
-
     if args.offline is True:
         lib.remove(args, nbdProc.pidFile)
 
     if not args.stdout:
         if args.noprogress is True:
-            logging.info(
-                "Backup of disk [%s] finished, file: [%s]", disk.target, targetFile
-            )
+            logging.info("Backup of disk [%s] finished, file: [%s]", disk.target, targetFile)
+
+        # finalize filename before checksumming
         partialfile.rename(targetFilePartial, targetFile)
-    if streamType != "raw":
-        backupChecksum(fileStream, targetFile)
+        _fsync_file(targetFile)
 
+        if streamType == "raw":
+            logging.info("RAW path: computing full-file Adler32 for %s", targetFile)
+            checksum = adler32_full_file(targetFile)
+            logging.info("RAW path: Adler32=%d", checksum)
+            write_checksum_sidecar(targetFile, checksum)
+        else:
+            logging.info("STREAM path: writing stream metadata checksum for %s", targetFile)
+            backupChecksum(fileStream, targetFile)
+
+    # Always return (even when args.stdout is True)
     return backupSize, True
+

libvirtnbdbackup/backup/metadata.py

@@ -15,7 +15,7 @@
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <https://www.gnu.org/licenses/>.
 """
-import os
+import os, zlib
 import logging
 from argparse import Namespace
 from typing import List, Union
@@ -31,6 +31,33 @@
 
 log = logging.getLogger()
 
+def adler32_full_file(path: str, bufsize: int = 8 * 1024 * 1024) -> int:
+    """
+    Compute Adler-32 over the entire file, matching virtnbdrestore's verify path.
+    """
+    csum = 1  # zlib.adler32 seed
+    with open(path, "rb") as f:
+        for chunk in iter(lambda: f.read(bufsize), b""):
+            csum = zlib.adler32(chunk, csum)
+    return csum & 0xFFFFFFFF
+
+def _fsync_file(path: str) -> None:
+    try:
+        with open(path, "rb", buffering=0) as f:
+            os.fsync(f.fileno())
+    except Exception:
+        pass
+
+def write_checksum_sidecar(target_file: str, crc: int) -> None:
+    sidecar = f"{target_file}.chksum"
+    with open(sidecar, "w") as fh:
+        fh.write(f"{crc}\n")
+    try:
+        with open(sidecar, "rb", buffering=0) as f:
+            os.fsync(f.fileno())
+    except Exception:
+        pass
+
 
 def backupChecksum(fileStream, targetFile):
     """Save the calculated adler32 checksum, it can be verified
@@ -144,4 +171,4 @@ def addFiles(args: Namespace, configFile: Union[str, None], zipStream, logFile:
         zipStream.zipStream.write(diskInfo, os.path.basename(diskInfo))
 
     log.info("Adding backup log [%s] to zipfile", logFile)
-    zipStream.zipStream.write(logFile, logFile)
+    zipStream.zipStream.write(logFile, logFile)