From: Jakub Narebski <jnareb@gmail.com>
To: Derrick Stolee <dstolee@microsoft.com>
Cc: "git\@vger.kernel.org" <git@vger.kernel.org>,
"gitster\@pobox.com" <gitster@pobox.com>,
"stolee\@gmail.com" <stolee@gmail.com>,
"avarab\@gmail.com" <avarab@gmail.com>,
"marten.agren\@gmail.com" <marten.agren@gmail.com>,
"peff\@peff.net" <peff@peff.net>
Subject: Re: [PATCH v3 16/20] commit-graph: verify contents match checksum
Date: Sat, 02 Jun 2018 17:52:40 +0200 [thread overview]
Message-ID: <86muwdtcc7.fsf@gmail.com> (raw)
In-Reply-To: <20180524162504.158394-17-dstolee@microsoft.com> (Derrick Stolee's message of "Thu, 24 May 2018 16:26:01 +0000")
Derrick Stolee <dstolee@microsoft.com> writes:
> The commit-graph file ends with a SHA1 hash of the previous contents. If
> a commit-graph file has errors but the checksum hash is correct, then we
> know that the problem is a bug in Git and not simply file corruption
> after-the-fact.
>
> Compute the checksum right away so it is the first error that appears,
> and make the message translatable since this error can be "corrected" by
> a user by simply deleting the file and recomputing. The rest of the
> errors are useful only to developers.
Should we then provide --quiet / --verbose options, so that ordinary
user is not flooded with error messages meant for power users and Git
developers, then?
>
> Be sure to continue checking the rest of the file data if the checksum
> is wrong. This is important for our tests, as we break the checksum as
> we modify bytes of the commit-graph file.
Well, we could have used sha1sum program, or test-sha1 helper to fix the
checksum after corrupting the commit-graph file...
>
> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
> ---
> commit-graph.c | 16 ++++++++++++++--
> t/t5318-commit-graph.sh | 6 ++++++
> 2 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/commit-graph.c b/commit-graph.c
> index d2b291aca2..a33600c584 100644
> --- a/commit-graph.c
> +++ b/commit-graph.c
> @@ -841,6 +841,7 @@ void write_commit_graph(const char *obj_dir,
> oids.nr = 0;
> }
>
> +#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
> static int verify_commit_graph_error;
>
> static void graph_report(const char *fmt, ...)
> @@ -860,7 +861,9 @@ static void graph_report(const char *fmt, ...)
> int verify_commit_graph(struct commit_graph *g)
> {
> uint32_t i, cur_fanout_pos = 0;
> - struct object_id prev_oid, cur_oid;
> + struct object_id prev_oid, cur_oid, checksum;
> + struct hashfile *f;
> + int devnull;
>
> if (!g) {
> graph_report("no commit-graph file loaded");
> @@ -879,6 +882,15 @@ int verify_commit_graph(struct commit_graph *g)
> if (verify_commit_graph_error)
> return verify_commit_graph_error;
>
> + devnull = open("/dev/null", O_WRONLY);
> + f = hashfd(devnull, NULL);
> + hashwrite(f, g->data, g->data_len - g->hash_len);
> + finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
> + if (hashcmp(checksum.hash, g->data + g->data_len - g->hash_len)) {
> + graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
> + verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
> + }
Is it the best way of calculating the SHA-1 checksum that out internal
APIs provide? Is it how SHA-1 checksum is calculated and checked for
packfiles?
> +
> for (i = 0; i < g->num_commits; i++) {
> struct commit *graph_commit;
>
> @@ -916,7 +928,7 @@ int verify_commit_graph(struct commit_graph *g)
> cur_fanout_pos++;
> }
>
> - if (verify_commit_graph_error)
> + if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
> return verify_commit_graph_error;
So if we detected that checksum do not match, but we have not found an
error, we say that it is all right?
>
> for (i = 0; i < g->num_commits; i++) {
> diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
> index 240aef6add..2680a2ebff 100755
> --- a/t/t5318-commit-graph.sh
> +++ b/t/t5318-commit-graph.sh
> @@ -279,6 +279,7 @@ GRAPH_COMMIT_DATA_WIDTH=`expr $HASH_LEN + 16`
> GRAPH_OCTOPUS_DATA_OFFSET=`expr $GRAPH_COMMIT_DATA_OFFSET + \
> $GRAPH_COMMIT_DATA_WIDTH \* $NUM_COMMITS`
> GRAPH_BYTE_OCTOPUS=`expr $GRAPH_OCTOPUS_DATA_OFFSET + 4`
> +GRAPH_BYTE_FOOTER=`expr $GRAPH_OCTOPUS_DATA_OFFSET + 4 \* $NUM_OCTOPUS_EDGES`
>
> # usage: corrupt_graph_and_verify <position> <data> <string>
> # Manipulates the commit-graph file at the position
> @@ -388,4 +389,9 @@ test_expect_success 'detect incorrect parent for octopus merge' '
> "invalid parent"
> '
>
> +test_expect_success 'detect invalid checksum hash' '
> + corrupt_graph_and_verify $GRAPH_BYTE_FOOTER "\00" \
> + "incorrect checksum"
This would not work under GETTEXT_POISON, as the message is marked as
translatable, but corrupt_graph_and_verify uses 'grep' and not
'test_i18grep' from t/test-lib-functions.sh
> +'
If it is pure checksum corruption, wouldn't this fail because it is not
a failure (exit code is 0)?
> +
> test_done
next prev parent reply other threads:[~2018-06-02 15:52 UTC|newest]
Thread overview: 149+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-17 18:10 [RFC PATCH 00/12] Integrate commit-graph into 'fsck' and 'gc' Derrick Stolee
2018-04-17 18:10 ` [RFC PATCH 01/12] fixup! commit-graph: always load commit-graph information Derrick Stolee
2018-04-17 18:10 ` [RFC PATCH 02/12] commit-graph: add 'check' subcommand Derrick Stolee
2018-04-19 13:24 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 03/12] commit-graph: check file header information Derrick Stolee
2018-04-19 15:58 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 04/12] commit-graph: parse commit from chosen graph Derrick Stolee
2018-04-19 17:21 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 06/12] commit: force commit to parse from object database Derrick Stolee
2018-04-20 12:13 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 05/12] commit-graph: check fanout and lookup table Derrick Stolee
2018-04-20 7:27 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 07/12] commit-graph: load a root tree from specific graph Derrick Stolee
2018-04-20 12:18 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 08/12] commit-graph: verify commit contents against odb Derrick Stolee
2018-04-20 16:47 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 10/12] commit-graph: add '--reachable' option Derrick Stolee
2018-04-20 17:17 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 09/12] fsck: check commit-graph Derrick Stolee
2018-04-20 16:59 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 12/12] commit-graph: update design document Derrick Stolee
2018-04-20 19:10 ` Jakub Narebski
2018-04-17 18:10 ` [RFC PATCH 11/12] gc: automatically write commit-graph files Derrick Stolee
2018-04-20 17:34 ` Jakub Narebski
2018-04-20 18:33 ` Ævar Arnfjörð Bjarmason
2018-04-17 18:50 ` [RFC PATCH 00/12] Integrate commit-graph into 'fsck' and 'gc' Derrick Stolee
2018-05-10 17:34 ` [PATCH 00/12] Integrate commit-graph into fsck, gc, and fetch Derrick Stolee
2018-05-10 17:34 ` [PATCH 01/12] commit-graph: add 'verify' subcommand Derrick Stolee
2018-05-10 18:15 ` Martin Ågren
2018-05-10 17:34 ` [PATCH 02/12] commit-graph: verify file header information Derrick Stolee
2018-05-10 18:21 ` Martin Ågren
2018-05-10 17:34 ` [PATCH 03/12] commit-graph: parse commit from chosen graph Derrick Stolee
2018-05-10 17:34 ` [PATCH 04/12] commit-graph: verify fanout and lookup table Derrick Stolee
2018-05-10 18:29 ` Martin Ågren
2018-05-11 15:17 ` Derrick Stolee
2018-05-10 17:34 ` [PATCH 05/12] commit: force commit to parse from object database Derrick Stolee
2018-05-10 17:34 ` [PATCH 06/12] commit-graph: load a root tree from specific graph Derrick Stolee
2018-05-10 17:34 ` [PATCH 07/12] commit-graph: verify commit contents against odb Derrick Stolee
2018-05-10 17:34 ` [PATCH 08/12] fsck: verify commit-graph Derrick Stolee
2018-05-10 17:34 ` [PATCH 09/12] commit-graph: add '--reachable' option Derrick Stolee
2018-05-10 17:34 ` [PATCH 10/12] gc: automatically write commit-graph files Derrick Stolee
2018-05-10 17:34 ` [PATCH 11/12] fetch: compute commit-graph by default Derrick Stolee
2018-05-10 17:34 ` [PATCH 12/12] commit-graph: update design document Derrick Stolee
2018-05-10 19:05 ` [PATCH 00/12] Integrate commit-graph into fsck, gc, and fetch Martin Ågren
2018-05-10 19:22 ` Stefan Beller
2018-05-11 17:23 ` Derrick Stolee
2018-05-11 17:30 ` Martin Ågren
2018-05-10 19:17 ` Ævar Arnfjörð Bjarmason
2018-05-11 17:23 ` Derrick Stolee
2018-05-11 21:15 ` [PATCH v2 00/12] Integrate commit-graph into fsck and gc Derrick Stolee
2018-05-11 21:15 ` [PATCH v2 01/12] commit-graph: add 'verify' subcommand Derrick Stolee
2018-05-12 13:31 ` Martin Ågren
2018-05-14 13:27 ` Derrick Stolee
2018-05-20 12:10 ` Jakub Narebski
2018-05-11 21:15 ` [PATCH v2 02/12] commit-graph: verify file header information Derrick Stolee
2018-05-12 13:35 ` Martin Ågren
2018-05-14 13:31 ` Derrick Stolee
2018-05-20 20:00 ` Jakub Narebski
2018-05-11 21:15 ` [PATCH v2 03/12] commit-graph: test that 'verify' finds corruption Derrick Stolee
2018-05-12 13:43 ` Martin Ågren
2018-05-21 18:53 ` Jakub Narebski
2018-05-24 16:28 ` Derrick Stolee
2018-05-11 21:15 ` [PATCH v2 04/12] commit-graph: parse commit from chosen graph Derrick Stolee
2018-05-12 20:50 ` Martin Ågren
2018-05-11 21:15 ` [PATCH v2 05/12] commit-graph: verify fanout and lookup table Derrick Stolee
2018-05-11 21:15 ` [PATCH v2 06/12] commit: force commit to parse from object database Derrick Stolee
2018-05-12 20:54 ` Martin Ågren
2018-05-11 21:15 ` [PATCH v2 07/12] commit-graph: load a root tree from specific graph Derrick Stolee
2018-05-12 20:55 ` Martin Ågren
2018-05-11 21:15 ` [PATCH v2 08/12] commit-graph: verify commit contents against odb Derrick Stolee
2018-05-12 21:17 ` Martin Ågren
2018-05-14 13:44 ` Derrick Stolee
2018-05-15 21:12 ` Martin Ågren
2018-05-11 21:15 ` [PATCH v2 09/12] fsck: verify commit-graph Derrick Stolee
2018-05-17 18:13 ` Martin Ågren
2018-05-11 21:15 ` [PATCH v2 11/12] gc: automatically write commit-graph files Derrick Stolee
2018-05-17 18:20 ` Martin Ågren
2018-05-11 21:15 ` [PATCH v2 10/12] commit-graph: add '--reachable' option Derrick Stolee
2018-05-17 18:16 ` Martin Ågren
2018-05-11 21:15 ` [PATCH v2 12/12] commit-graph: update design document Derrick Stolee
2018-05-24 16:25 ` [PATCH v3 00/20] Integrate commit-graph into 'fsck' and 'gc' Derrick Stolee
2018-05-24 16:25 ` [PATCH v3 01/20] commit-graph: UNLEAK before die() Derrick Stolee
2018-05-24 22:47 ` Stefan Beller
2018-05-25 0:08 ` Derrick Stolee
2018-05-24 16:25 ` [PATCH v3 02/20] commit-graph: fix GRAPH_MIN_SIZE Derrick Stolee
2018-05-26 18:46 ` Jakub Narebski
2018-05-26 20:30 ` brian m. carlson
2018-06-02 19:43 ` Jakub Narebski
2018-05-24 16:25 ` [PATCH v3 03/20] commit-graph: parse commit from chosen graph Derrick Stolee
2018-05-27 10:23 ` Jakub Narebski
2018-05-29 12:31 ` Derrick Stolee
2018-05-24 16:25 ` [PATCH v3 04/20] commit: force commit to parse from object database Derrick Stolee
2018-05-27 18:04 ` Jakub Narebski
2018-05-24 16:25 ` [PATCH v3 05/20] commit-graph: load a root tree from specific graph Derrick Stolee
2018-05-27 19:12 ` Jakub Narebski
2018-05-24 16:25 ` [PATCH v3 06/20] commit-graph: add 'verify' subcommand Derrick Stolee
2018-05-27 22:55 ` Jakub Narebski
2018-05-30 16:07 ` Derrick Stolee
2018-06-02 21:19 ` Jakub Narebski
2018-06-04 11:30 ` Derrick Stolee
2018-05-24 16:25 ` [PATCH v3 07/20] commit-graph: verify catches corrupt signature Derrick Stolee
2018-05-28 14:05 ` Jakub Narebski
2018-05-29 12:43 ` Derrick Stolee
2018-06-02 22:30 ` Jakub Narebski
2018-05-24 16:25 ` [PATCH v3 08/20] commit-graph: verify required chunks are present Derrick Stolee
2018-05-28 17:11 ` Jakub Narebski
2018-05-24 16:25 ` [PATCH v3 09/20] commit-graph: verify corrupt OID fanout and lookup Derrick Stolee
2018-05-30 13:34 ` Jakub Narebski
2018-05-30 16:18 ` Derrick Stolee
2018-06-02 4:38 ` Duy Nguyen
2018-06-04 11:32 ` Derrick Stolee
2018-06-04 14:42 ` Duy Nguyen
2018-05-24 16:25 ` [PATCH v3 10/20] commit-graph: verify objects exist Derrick Stolee
2018-05-30 19:22 ` Jakub Narebski
2018-05-31 12:53 ` Derrick Stolee
2018-05-24 16:25 ` [PATCH v3 11/20] commit-graph: verify root tree OIDs Derrick Stolee
2018-05-30 22:24 ` Jakub Narebski
2018-05-31 13:16 ` Derrick Stolee
2018-06-02 22:50 ` Jakub Narebski
2018-05-24 16:25 ` [PATCH v3 12/20] commit-graph: verify parent list Derrick Stolee
2018-06-01 23:21 ` Jakub Narebski
2018-05-24 16:25 ` [PATCH v3 13/20] commit-graph: verify generation number Derrick Stolee
2018-06-02 12:23 ` Jakub Narebski
2018-06-04 11:47 ` Derrick Stolee
2018-05-24 16:25 ` [PATCH v3 14/20] commit-graph: verify commit date Derrick Stolee
2018-06-02 12:29 ` Jakub Narebski
2018-05-24 16:25 ` [PATCH v3 15/20] commit-graph: test for corrupted octopus edge Derrick Stolee
2018-06-02 12:39 ` Jakub Narebski
2018-06-04 13:08 ` Derrick Stolee
2018-05-24 16:26 ` [PATCH v3 16/20] commit-graph: verify contents match checksum Derrick Stolee
2018-05-30 12:35 ` SZEDER Gábor
2018-06-02 15:52 ` Jakub Narebski [this message]
2018-06-04 11:55 ` Derrick Stolee
2018-05-24 16:26 ` [PATCH v3 17/20] fsck: verify commit-graph Derrick Stolee
2018-06-02 16:17 ` Jakub Narebski
2018-06-04 11:59 ` Derrick Stolee
2018-05-24 16:26 ` [PATCH v3 18/20] commit-graph: add '--reachable' option Derrick Stolee
2018-06-02 17:34 ` Jakub Narebski
2018-06-04 12:44 ` Derrick Stolee
2018-05-24 16:26 ` [PATCH v3 19/20] gc: automatically write commit-graph files Derrick Stolee
2018-06-02 18:03 ` Jakub Narebski
2018-06-04 12:51 ` Derrick Stolee
2018-05-24 16:26 ` [PATCH v3 20/20] commit-graph: update design document Derrick Stolee
2018-06-02 18:27 ` Jakub Narebski
2018-05-24 21:15 ` [PATCH v3 00/20] Integrate commit-graph into 'fsck' and 'gc' Ævar Arnfjörð Bjarmason
2018-05-25 4:11 ` Junio C Hamano
2018-05-29 4:27 ` Junio C Hamano
2018-05-29 12:37 ` Derrick Stolee
2018-05-29 13:41 ` Junio C Hamano
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