[PATCH 4/4] midx: report checksum mismatches during 'verify'
- From
Taylor Blau <me@ttaylorr.com>
- Date
- Jun 23, 2021, 18:39 UTC
- Message-ID
- <94e9de44e3b52513c5ab48aecd74f809dc34cbe3.1624473543.git.me@ttaylorr.com>
- In-Reply-To
- <cover.1624473543.git.me@ttaylorr.com>
'git multi-pack-index verify' inspects the data in an existing MIDX for correctness by checking that the recorded object offsets are correct, and so on.
But it does not check that the file's trailing checksum matches the data that it records. So, if an on-disk corruption happened to occur in the final few bytes (and all other data was recorded correctly), we would:
- get a clean result from 'git multi-pack-index verify', but
- be unable to reuse the existing MIDX when writing a new one (since
we now check for checksum mismatches before reusing a MIDX)Teach the 'verify' sub-command to recognize corruption in the checksum by calling midx_checksum_valid().
Suggested-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> --- midx.c | 3 +++ t/t5319-multi-pack-index.sh | 5 +++++ 2 files changed, 8 insertions(+)
diff --git a/midx.c b/midx.c index a12cbbf928..9a35b0255d 100644 --- a/midx.c +++ b/midx.c @@ -1228,6 +1228,9 @@ int verify_midx_file(struct repository *r, const char *object_dir, unsigned flag return result; } + if (!midx_checksum_valid(m)) + midx_report(_("incorrect checksum")); + if (flags & MIDX_PROGRESS) progress = start_delayed_progress(_("Looking for referenced packfiles"), m->num_packs); diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh index d582f370c4..7609f1ea64 100755 --- a/t/t5319-multi-pack-index.sh +++ b/t/t5319-multi-pack-index.sh @@ -418,6 +418,11 @@ test_expect_success 'corrupt MIDX is not reused' ' git multi-pack-index verify ' +test_expect_success 'verify incorrect checksum' ' + pos=$(($(wc -c <$objdir/pack/multi-pack-index) - 1)) && + corrupt_midx_and_verify $pos "\377" $objdir "incorrect checksum" +' + test_expect_success 'repack progress off for redirected stderr' ' GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir repack 2>err && test_line_count = 0 err
-- 2.31.1.163.ga65ce7f831