Re: [PATCH 5/5] transport-helper: fix sync issue on crashes
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Apr 14, 2014, 21:25 UTC
- Message-ID
- <xmqq38hfmwml.fsf@gitster.dls.corp.google.com>
- In-Reply-To
- <1397334812-12215-6-git-send-email-felipe.contreras@gmail.com>
Felipe Contreras <felipe.contreras@gmail.com> writes:
Show 14 quoted lines
> When a remote helper crashes while pushing we should revert back to the
> state before the push, however, it's possible that `git fast-export`
> already finished its job, and therefore has exported the marks already.
>
> This creates a synchronization problem because from that moment on
> `git fast-{import,export}` will have marks that the remote helper is not
> aware of and all further commands fail (if those marks are referenced).
>
> The fix is to tell `git fast-export` to export to a temporary file, and
> only after the remote helper has finishes successfully, move to the
> final destination.
>
> Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
> ---This seems to be based on a somewhat older codebase; I tried to be careful while adjusting the patch to the current codebase, but please give it an eyeball to see if I didn't make any silly mistake when I push today's integration result out in a few hours.
Thanks.
Show 70 quoted lines
> t/t5801-remote-helpers.sh | 17 ++++++++++++++++-
> transport-helper.c | 13 +++++++++++--
> 2 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/t/t5801-remote-helpers.sh b/t/t5801-remote-helpers.sh
> index 613f69a..cf7fd43 100755
> --- a/t/t5801-remote-helpers.sh
> +++ b/t/t5801-remote-helpers.sh
> @@ -207,6 +207,17 @@ test_expect_success 'push update refs failure' '
> )
> '
>
> +clean_mark () {
> + cut -f 2 -d ' ' $1 | git cat-file --batch-check | grep commit | sort > $(basename $1)
> +}
> +
> +cmp_marks () {
> + test_when_finished "rm -rf git.marks testgit.marks" &&
> + clean_mark .git/testgit/$1/git.marks &&
> + clean_mark .git/testgit/$1/testgit.marks &&
> + test_cmp git.marks testgit.marks
> +}
> +
> test_expect_success 'proper failure checks for fetching' '
> (GIT_REMOTE_TESTGIT_FAILURE=1 &&
> export GIT_REMOTE_TESTGIT_FAILURE &&
> @@ -221,7 +232,11 @@ test_expect_success 'proper failure checks for pushing' '
> (GIT_REMOTE_TESTGIT_FAILURE=1 &&
> export GIT_REMOTE_TESTGIT_FAILURE &&
> cd local &&
> - test_must_fail git push --all
> + git checkout -b crash master &&
> + echo crash >> file &&
> + git commit -a -m crash &&
> + test_must_fail git push --all &&
> + cmp_marks origin
> )
> '
>
> diff --git a/transport-helper.c b/transport-helper.c
> index 2747f98..090c863 100644
> --- a/transport-helper.c
> +++ b/transport-helper.c
> @@ -434,7 +434,7 @@ static int get_exporter(struct transport *transport,
> fastexport->argv[argc++] = data->signed_tags ?
> "--signed-tags=verbatim" : "--signed-tags=warn-strip";
> if (data->export_marks) {
> - strbuf_addf(&tmp, "--export-marks=%s", data->export_marks);
> + strbuf_addf(&tmp, "--export-marks=%s.tmp", data->export_marks);
> fastexport->argv[argc++] = strbuf_detach(&tmp, NULL);
> }
> if (data->import_marks) {
> @@ -901,7 +901,16 @@ static int push_refs_with_export(struct transport *transport,
>
> if (finish_command(&exporter))
> die("Error while running fast-export");
> - return push_update_refs_status(data, remote_refs);
> + if (push_update_refs_status(data, remote_refs))
> + return 1;
> +
> + if (data->export_marks) {
> + strbuf_addf(&buf, "%s.tmp", data->export_marks);
> + rename(buf.buf, data->export_marks);
> + strbuf_release(&buf);
> + }
> +
> + return 0;
> }
>
> static int push_refs(struct transport *transport,