check: handle Ctrl-C at safe boundaries (#7893)

src/borg/archive.py

@@ -32,7 +32,7 @@
 from .helpers import BackupOSError, BackupPermissionError, BackupFileNotFoundError, BackupIOError
 from .helpers import HardLinkManager
 from .helpers import ChunkIteratorFileWrapper, open_item
-from .helpers import Error, IntegrityError, set_ec
+from .helpers import Error, IntegrityError, set_ec, sig_int
 from .platform import uid2user, user2uid, gid2group, group2gid, get_birthtime_ns
 from .helpers import parse_timestamp, archive_ts_now, CompressionSpec
 from .helpers import OutputTimestamp, format_timedelta, format_file_size, file_status, FileSize
@@ -1924,12 +1924,24 @@ def check(
                 rebuild_manifest = True
         if rebuild_manifest:
             self.manifest = self.rebuild_manifest()
-        if find_lost_archives:
-            self.rebuild_archives_directory()
-        self.rebuild_archives(
-            match=match, first=first, last=last, sort_by=sort_by, older=older, oldest=oldest, newer=newer, newest=newest
-        )
+        # On Ctrl-C, skip the remaining scans.
+        if not sig_int:
+            if find_lost_archives:
+                self.rebuild_archives_directory()
+            self.rebuild_archives(
+                match=match,
+                first=first,
+                last=last,
+                sort_by=sort_by,
+                older=older,
+                oldest=oldest,
+                newer=newer,
+                newest=newest,
+            )
+        # finish() writes the manifest and a consistent chunk index; run it on Ctrl-C too (#9850).
         self.finish()
+        if sig_int:
+            raise Error("Got Ctrl-C / SIGINT.")
         if self.error_found:
             logger.error("Archive consistency check complete, problems found.")
         else:
@@ -1977,12 +1989,16 @@ def verify_data(self):
         logger.info("Starting cryptographic data integrity verification...")
         chunks_count = len(self.chunks)
         errors = 0
+        verified = 0  # chunks actually verified
         defect_chunks = []
         pi = ProgressIndicatorPercent(
             total=chunks_count, msg="Verifying data %6.2f%%", step=0.01, msgid="check.verify_data"
         )
         for chunk_id, _ in self.chunks.iteritems():
+            if sig_int:
+                break
             pi.show()
+            verified += 1
             try:
                 encrypted_data = self.repository.get(chunk_id)
             except (Repository.ObjectNotFound, IntegrityErrorBase) as err:
@@ -2038,11 +2054,20 @@ def verify_data(self):
                 for defect_chunk in defect_chunks:
                     logger.debug("chunk %s is defect.", bin_to_hex(defect_chunk))
         log = logger.error if errors else logger.info
-        log(
-            "Finished cryptographic data integrity verification, verified %d chunks with %d integrity errors.",
-            chunks_count,
-            errors,
-        )
+        if sig_int:
+            log(
+                "Interrupted cryptographic data integrity verification, "
+                "verified %d of %d chunks with %d integrity errors.",
+                verified,
+                chunks_count,
+                errors,
+            )
+        else:
+            log(
+                "Finished cryptographic data integrity verification, verified %d chunks with %d integrity errors.",
+                verified,
+                errors,
+            )
 
     def rebuild_manifest(self):
         """Rebuild the manifest object."""
@@ -2078,6 +2103,8 @@ def valid_archive(obj):
             msgid="check.rebuild_archives_directory",
         )
         for chunk_id, _ in self.chunks.iteritems():
+            if sig_int:
+                break
             pi.show()
             cdata = self.repository.get(chunk_id, read_data=False)  # only get metadata
             try:
@@ -2123,7 +2150,10 @@ def valid_archive(obj):
                         logger.warning(f"Would create archives directory entry for {name} {archive_id_hex}.")
 
         pi.finish()
-        logger.info("Rebuilding missing archives directory entries completed.")
+        if sig_int:
+            logger.info("Rebuilding missing archives directory entries interrupted.")
+        else:
+            logger.info("Rebuilding missing archives directory entries completed.")
 
     def rebuild_archives(
         self, first=0, last=0, sort_by="", match=None, older=None, newer=None, oldest=None, newest=None
@@ -2271,6 +2301,9 @@ def valid_item(obj):
             total=num_archives, msg="Checking archives %3.1f%%", step=0.1, msgid="check.rebuild_archives"
         )
         for i, info in enumerate(archive_infos):
+            if sig_int:
+                # Break only between archives, as --repair rewrites each archive as a whole.
+                break
             pi.show(i)
             archive_id, archive_id_hex = info.id, bin_to_hex(info.id)
             try:

src/borg/archiver/check_cmd.py

@@ -3,8 +3,8 @@
 from ._common import with_repository, Highlander
 from ..archive import ArchiveChecker
 from ..constants import *  # NOQA
-from ..helpers import set_ec, EXIT_WARNING, CancelledByUser, CommandError, IntegrityError
-from ..helpers import yes, ArchiveFormatter
+from ..helpers import set_ec, EXIT_WARNING, CancelledByUser, CommandError, Error, IntegrityError
+from ..helpers import yes, ArchiveFormatter, sig_int
 from ..helpers.argparsing import ArgumentParser
 
 from ..logger import create_logger
@@ -66,6 +66,8 @@ def do_check(self, args, repository):
         if not args.archives_only:
             if not repository.check(repair=args.repair, max_duration=args.max_duration):
                 set_ec(EXIT_WARNING)
+            if sig_int:  # repository check interrupted; skip the archive check
+                raise Error("Got Ctrl-C / SIGINT.")
         if not args.repo_only and not archive_checker.check(
             repository,
             verify_data=args.verify_data,
@@ -160,6 +162,14 @@ def build_parser_check(self, subparsers, common_parser, mid_common_parser):
         formatted by giving a custom format using ``--format`` (see the ``borg repo-list``
         description for more details about the format string).
 
+        If the ``borg check`` process receives a SIGINT signal (Ctrl-C), it stops at the
+        next safe boundary (a pack boundary during the repository check, an archive boundary
+        during the archive check), leaving the repository and its chunk index in a consistent
+        state. A partial repository check (``--max-duration``) saves its progress so a later
+        partial check resumes where it stopped; a full check restarts from the beginning.
+        With ``--repair``, an interrupted archive check may leave some archives already
+        repaired and others not yet processed, so run ``borg check --repair`` again to finish.
+
         About repair mode
         +++++++++++++++++
 

src/borg/repository.py

@@ -877,6 +877,10 @@ def store_list(namespace):
             pack_infos = store_list("packs")
             pack_pi = ProgressIndicatorPercent(total=len(pack_infos), msg="Checking packs %3.0f%%", msgid="check.packs")
             for info in pack_infos:
+                if sig_int:  # on Ctrl-C, persist checked packs, then stop
+                    logger.info(f"Interrupted repository check, {len(tracker)} packs checked so far.")
+                    tracker.save()
+                    break
                 self._lock_refresh()
                 pack_pi.show(increase=1)  # advance for skipped packs too, so the bar tracks packs/, not work done
                 pack_id = hex_to_bin(info.name)
@@ -913,7 +917,10 @@ def store_list(namespace):
             f"Checked {index_files} index files ({index_errors} errors) and {pack_files} packs ({pack_errors} errors)."
         )
         if objs_errors == 0:
-            logger.info(f"Finished {mode} repository check, no problems found.")
+            if sig_int:
+                logger.info(f"Interrupted {mode} repository check, no problems found so far.")
+            else:
+                logger.info(f"Finished {mode} repository check, no problems found.")
         elif repair:
             logger.error(f"Finished {mode} repository check, errors found (repository repair not implemented).")
         else:

src/borg/testsuite/archiver/check_cmd_test.py

@@ -6,11 +6,11 @@
 
 import pytest
 
-from ...archive import ChunkBuffer
+from ...archive import ArchiveChecker, ChunkBuffer
 from ...constants import *  # NOQA
-from ...helpers import bin_to_hex, msgpack, CommandError, IntegrityError
-from ...manifest import Manifest
-from ...repository import Repository
+from ...helpers import bin_to_hex, msgpack, CommandError, Error, IntegrityError, sig_int
+from ...manifest import Archives, Manifest
+from ...repository import PackTracker, Repository
 from ..repository_test import fchunk, corrupt_chunk_on_disk
 from . import (
     cmd,
@@ -74,6 +74,96 @@ def test_check_usage(archivers, request):
     assert "archive2" in output
 
 
+def test_check_soft_interrupt(archivers, request, monkeypatch):
+    """A mid-run Ctrl-C stops both check phases at a safe boundary (#7893): the repository check persists
+    its progress for a later partial check to resume, the archive check runs finish() and then raises.
+    The check is read-only, so a normal check still passes afterwards."""
+    archiver = request.getfixturevalue(archivers)
+    check_cmd_setup(archiver)  # produces many packs
+
+    # repository check: interrupt after a few packs.
+    with Repository(archiver.repository_path, exclusive=True) as repository:
+        orig_hash = repository.store.hash
+        hash_calls = 0
+
+        def hash_then_interrupt(key):
+            nonlocal hash_calls
+            hash_calls += 1
+            result = orig_hash(key)
+            if hash_calls == 5:  # trip mid-run, after several packs
+                sig_int._sig_int_triggered = True
+            return result
+
+        monkeypatch.setattr(repository.store, "hash", hash_then_interrupt)
+        try:
+            assert repository.check() is True  # interrupted, no errors found
+        finally:
+            sig_int._sig_int_triggered = False
+        assert len(PackTracker.load(repository.store)) > 0  # the verified packs were persisted
+
+    # a partial check resumes the saved cycle.
+    output = cmd(archiver, "check", "-v", "--repository-only", "--max-duration=600", exit_code=0)
+    assert "Continuing check cycle" in output
+
+    # archive check: interrupt verify_data after 3 chunks.
+    with Repository(archiver.repository_path, exclusive=True) as repository:
+        orig_get = repository.get
+        get_calls = 0
+        interrupted_after = None
+
+        def get_then_interrupt(*args, **kwargs):
+            nonlocal get_calls, interrupted_after
+            get_calls += 1
+            if get_calls == 3:  # trip mid-loop, after 3 chunks
+                sig_int._sig_int_triggered = True
+                interrupted_after = get_calls
+            return orig_get(*args, **kwargs)
+
+        monkeypatch.setattr(repository, "get", get_then_interrupt)
+        try:
+            with pytest.raises(Error, match="Got Ctrl-C"):
+                ArchiveChecker().check(repository, verify_data=True, sort_by="ts", format="{archive} {time} {id}")
+        finally:
+            sig_int._sig_int_triggered = False
+        assert interrupted_after == 3  # the loop stopped mid-run, after verifying 3 chunks
+
+    # nothing changed, so a normal check passes.
+    cmd(archiver, "check", exit_code=0)
+
+
+def test_check_repair_soft_interrupt(archivers, request, monkeypatch):
+    """A Ctrl-C after the first archive of a --repair archive check stops at the archive boundary, runs
+    finish() (dropping the chunk index, writing the manifest), then raises. No archive is lost, and a
+    second --repair finishes the job so a following check reports the repository consistent."""
+    archiver = request.getfixturevalue(archivers)
+    check_cmd_setup(archiver)  # two archives
+
+    orig_create = Archives.create
+
+    def create_then_interrupt(self, *args, **kwargs):
+        orig_create(self, *args, **kwargs)
+        sig_int._sig_int_triggered = True  # one Ctrl-C after the first archive was rebuilt
+
+    monkeypatch.setattr(Archives, "create", create_then_interrupt)
+    try:
+        with Repository(archiver.repository_path, exclusive=True) as repository:
+            with pytest.raises(Error, match="Got Ctrl-C"):
+                ArchiveChecker().check(repository, repair=True, sort_by="ts", format="{archive} {time} {id}")
+    finally:
+        sig_int._sig_int_triggered = False  # reset the global flag for the following tests
+    # restore the real method; monkeypatch.undo() would also drop the autouse env (BORG_TESTONLY_WEAKEN_KDF).
+    monkeypatch.setattr(Archives, "create", orig_create)
+
+    # both archives survive the interrupt between archives.
+    output = cmd(archiver, "repo-list", exit_code=0)
+    assert "archive1" in output
+    assert "archive2" in output
+
+    # a second --repair finishes the job; a plain check then finds no problems.
+    cmd(archiver, "check", "--repair", exit_code=0)
+    cmd(archiver, "check", exit_code=0)
+
+
 def test_date_matching(archivers, request):
     archiver = request.getfixturevalue(archivers)
     check_cmd_setup(archiver)