threads / patch / 54046

patchfetch-pack: make packfile URIs work with transfer.fsckobjects

Subject: [PATCH] fetch-pack: make packfile URIs work with transfer.fsckobjects

## tl;dr

8 messages between Aug 14, 2020 and Aug 17, 2020. Diffs are folded; open one to read it.

replies: 7people: 3as markdown or json

Jonathan Tan· Aug 14, 2020, 19:32 UTC · lore

When fetching with packfile URIs and transfer.fsckobjects=1, use the --fsck-objects instead of the --strict flag when invoking index-pack so that links are not checked, only objects. This is because incomplete links are expected. (A subsequent connectivity check will be done when all the packs have been downloaded regardless of whether transfer.fsckobjects is set.)

This is similar to 98a2ea46c2 ("fetch-pack: do not check links for partial fetch", 2018-03-15), but for packfile URIs instead of partial clones.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
The subject is longer than 50 characters but I couldn't find a way to
shorten it, especially since I think it's important to mention packfile
URIs and transfer.fsckobjects. Any suggestions appreciated.
---
 fetch-pack.c           |  2 +-
 t/t5702-protocol-v2.sh | 53 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
Show changes to 2 files +54 −1

fetch-pack.c, t/t5702-protocol-v2.sh

diff --git a/fetch-pack.c b/fetch-pack.c
index 7f20eca4f8..66631d0034 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -892,7 +892,7 @@ static int get_pack(struct fetch_pack_args *args,
 	    : transfer_fsck_objects >= 0
 	    ? transfer_fsck_objects
 	    : 0) {
-		if (args->from_promisor)
+		if (args->from_promisor || !only_packfile)
 			/*
 			 * We cannot use --strict in index-pack because it
 			 * checks both broken objects and links, but we only
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 5a60fbe3ed..8c6c67b10d 100755
--- a/t/t5702-protocol-v2.sh
+++ b/t/t5702-protocol-v2.sh
@@ -883,6 +883,59 @@ test_expect_success 'fetching with valid packfile URI but invalid hash fails' '
 	test_i18ngrep "pack downloaded from.*does not match expected hash" err
 '
 
+test_expect_success 'packfile-uri with transfer.fsckobjects' '
+	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	rm -rf "$P" http_child log &&
+
+	git init "$P" &&
+	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
+
+	echo my-blob >"$P/my-blob" &&
+	git -C "$P" add my-blob &&
+	git -C "$P" commit -m x &&
+
+	configure_exclusion "$P" my-blob >h &&
+
+	sane_unset GIT_TEST_SIDEBAND_ALL &&
+	git -c protocol.version=2 -c transfer.fsckobjects=1 \
+		-c fetch.uriprotocols=http,https \
+		clone "$HTTPD_URL/smart/http_parent" http_child &&
+
+	# Ensure that there are exactly 4 files (2 .pack and 2 .idx).
+	ls http_child/.git/objects/pack/* >filelist &&
+	test_line_count = 4 filelist
+'
+
+test_expect_success 'packfile-uri with transfer.fsckobjects fails on bad object' '
+	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	rm -rf "$P" http_child log &&
+
+	git init "$P" &&
+	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
+
+	cat >bogus-commit <<EOF &&
+tree $EMPTY_TREE
+author Bugs Bunny 1234567890 +0000
+committer Bugs Bunny <bugs@bun.ni> 1234567890 +0000
+
+This commit object intentionally broken
+EOF
+	BOGUS=$(git -C "$P" hash-object -t commit -w --stdin <bogus-commit) &&
+	git -C "$P" branch bogus-branch "$BOGUS" &&
+
+	echo my-blob >"$P/my-blob" &&
+	git -C "$P" add my-blob &&
+	git -C "$P" commit -m x &&
+
+	configure_exclusion "$P" my-blob >h &&
+
+	sane_unset GIT_TEST_SIDEBAND_ALL &&
+	test_must_fail git -c protocol.version=2 -c transfer.fsckobjects=1 \
+		-c fetch.uriprotocols=http,https \
+		clone "$HTTPD_URL/smart/http_parent" http_child 2>error &&
+	test_i18ngrep "invalid author/committer line - missing email" error
+'
+
 # DO NOT add non-httpd-specific tests here, because the last part of this
 # test script is only executed when httpd is available and enabled.
 
-- 
2.28.0.220.ged08abb693-goog
Junio C Hamano· Aug 14, 2020, 19:59 UTC · re: Jonathan Tan · lore

Re: [PATCH] fetch-pack: make packfile URIs work with transfer.fsckobjects

Jonathan Tan <jonathantanmy@google.com> writes:
Show 6 quoted lines
> When fetching with packfile URIs and transfer.fsckobjects=1, use the
> --fsck-objects instead of the --strict flag when invoking index-pack so
> that links are not checked, only objects. This is because incomplete
> links are expected. (A subsequent connectivity check will be done when
> all the packs have been downloaded regardless of whether
> transfer.fsckobjects is set.)

Good reasoning. The change looks surprisingly small, thanks to the existing need already.

I realize that the code's quality (from readability and discoverability's point of view) has deteriorated in this area quite a lot over the past few years, though. The "from_promisor" field is set when fetch-pack is run with the corresponding command line option, but the option is documented nowhere, so it is not immediately obvious why the new need can be fulfilled by just piggybacking on the existing codepath. The meaning of the only_packfile parameter get_pack() takes is never explained anywhere, either.

Show 13 quoted lines
> diff --git a/fetch-pack.c b/fetch-pack.c
> index 7f20eca4f8..66631d0034 100644
> --- a/fetch-pack.c
> +++ b/fetch-pack.c
> @@ -892,7 +892,7 @@ static int get_pack(struct fetch_pack_args *args,
>  	    : transfer_fsck_objects >= 0
>  	    ? transfer_fsck_objects
>  	    : 0) {
> -		if (args->from_promisor)
> +		if (args->from_promisor || !only_packfile)
>  			/*
>  			 * We cannot use --strict in index-pack because it
>  			 * checks both broken objects and links, but we only

I think this is a good way to work around the "we do not have full set of objects until we grab out-of-line packfiles, but we process the in-protocol packdata before we grab them, so we cannot validate yet" problem. My guess is that "only_packfile" means "after reading this packfile, the repository should be fully complete and we can afford to check for connectivity", which would be always true for protocol below v2 that lack the packfile-uri extension (hence the call to get_pack() in do_fetch_pack() passes hardcoded 1 in this parameter). The v2 codepath in do_fetch_pack_v2() calls get_pack() with true only when there is no packfile-uri, so we loosen the validation when we know we will further grab one or more packfiles out of line.

Show 20 quoted lines
> +test_expect_success 'packfile-uri with transfer.fsckobjects' '
> +	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
> +	rm -rf "$P" http_child log &&
> +
> +	git init "$P" &&
> +	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
> +
> +	echo my-blob >"$P/my-blob" &&
> +	git -C "$P" add my-blob &&
> +	git -C "$P" commit -m x &&
> +
> +	configure_exclusion "$P" my-blob >h &&
> +
> +	sane_unset GIT_TEST_SIDEBAND_ALL &&
> +	git -c protocol.version=2 -c transfer.fsckobjects=1 \
> +		-c fetch.uriprotocols=http,https \
> +		clone "$HTTPD_URL/smart/http_parent" http_child &&
> +
> +	# Ensure that there are exactly 4 files (2 .pack and 2 .idx).
> +	ls http_child/.git/objects/pack/* >filelist &&
Subtle but correct.
Show 17 quoted lines
> +	test_line_count = 4 filelist
> +'
> +
> +test_expect_success 'packfile-uri with transfer.fsckobjects fails on bad object' '
> +	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
> +	rm -rf "$P" http_child log &&
> +
> +	git init "$P" &&
> +	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
> +
> +	cat >bogus-commit <<EOF &&
> +tree $EMPTY_TREE
> +author Bugs Bunny 1234567890 +0000
> +committer Bugs Bunny <bugs@bun.ni> 1234567890 +0000
> +
> +This commit object intentionally broken
> +EOF
Use <<-EOF for readablity, please.
Show 18 quoted lines
> +	BOGUS=$(git -C "$P" hash-object -t commit -w --stdin <bogus-commit) &&
> +	git -C "$P" branch bogus-branch "$BOGUS" &&
> +
> +	echo my-blob >"$P/my-blob" &&
> +	git -C "$P" add my-blob &&
> +	git -C "$P" commit -m x &&
> +
> +	configure_exclusion "$P" my-blob >h &&
> +
> +	sane_unset GIT_TEST_SIDEBAND_ALL &&
> +	test_must_fail git -c protocol.version=2 -c transfer.fsckobjects=1 \
> +		-c fetch.uriprotocols=http,https \
> +		clone "$HTTPD_URL/smart/http_parent" http_child 2>error &&
> +	test_i18ngrep "invalid author/committer line - missing email" error
> +'
> +
>  # DO NOT add non-httpd-specific tests here, because the last part of this
>  # test script is only executed when httpd is available and enabled.
Jonathan Tan· Aug 17, 2020, 19:48 UTC · re: Jonathan Tan · lore

[PATCH v2 0/3] make packfile URIs work with transfer.fsckobjects

Thanks, Junio, for taking a look.
Differences from v1:
 - Added 2 patches that document parts that Junio mentioned were
   underdocumented [1]. I'm not sure about only_packfile, since it's
   narrowly scoped (just an argument in a static function) but I've
   included it anyway.
 - Used <<-EOF instead of <<EOF.
[1] https://lore.kernel.org/git/xmqq8sehvw13.fsf@gitster.c.googlers.com/
Jonathan Tan (3):
  (various): document from_promisor parameter
  fetch-pack: document only_packfile in get_pack()
  fetch-pack: make packfile URIs work with transfer.fsckobjects
 fetch-pack.c           |  6 ++++-
 fetch-pack.h           |  8 +++++++
 remote-curl.c          |  3 +++
 t/t5702-protocol-v2.sh | 53 ++++++++++++++++++++++++++++++++++++++++++
 transport.h            |  3 +++
 5 files changed, 72 insertions(+), 1 deletion(-)
-- 
2.28.0.220.ged08abb693-goog
Jonathan Tan· Aug 17, 2020, 19:48 UTC · re: Jonathan Tan · lore

[PATCH v2 3/3] fetch-pack: make packfile URIs work with transfer.fsckobjects

When fetching with packfile URIs and transfer.fsckobjects=1, use the --fsck-objects instead of the --strict flag when invoking index-pack so that links are not checked, only objects. This is because incomplete links are expected. (A subsequent connectivity check will be done when all the packs have been downloaded regardless of whether transfer.fsckobjects is set.)

This is similar to 98a2ea46c2 ("fetch-pack: do not check links for partial fetch", 2018-03-15), but for packfile URIs instead of partial clones.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
The subject is longer than 50 characters but I couldn't find a way to
shorten it, especially since I think it's important to mention packfile
URIs and transfer.fsckobjects. Any suggestions appreciated.
---
 fetch-pack.c           |  2 +-
 t/t5702-protocol-v2.sh | 53 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
Show changes to 2 files +54 −1

fetch-pack.c, t/t5702-protocol-v2.sh

diff --git a/fetch-pack.c b/fetch-pack.c
index 289121038e..0f1a84c061 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -896,7 +896,7 @@ static int get_pack(struct fetch_pack_args *args,
 	    : transfer_fsck_objects >= 0
 	    ? transfer_fsck_objects
 	    : 0) {
-		if (args->from_promisor)
+		if (args->from_promisor || !only_packfile)
 			/*
 			 * We cannot use --strict in index-pack because it
 			 * checks both broken objects and links, but we only
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 5a60fbe3ed..8c6c67b10d 100755
--- a/t/t5702-protocol-v2.sh
+++ b/t/t5702-protocol-v2.sh
@@ -883,6 +883,59 @@ test_expect_success 'fetching with valid packfile URI but invalid hash fails' '
 	test_i18ngrep "pack downloaded from.*does not match expected hash" err
 '
 
+test_expect_success 'packfile-uri with transfer.fsckobjects' '
+	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	rm -rf "$P" http_child log &&
+
+	git init "$P" &&
+	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
+
+	echo my-blob >"$P/my-blob" &&
+	git -C "$P" add my-blob &&
+	git -C "$P" commit -m x &&
+
+	configure_exclusion "$P" my-blob >h &&
+
+	sane_unset GIT_TEST_SIDEBAND_ALL &&
+	git -c protocol.version=2 -c transfer.fsckobjects=1 \
+		-c fetch.uriprotocols=http,https \
+		clone "$HTTPD_URL/smart/http_parent" http_child &&
+
+	# Ensure that there are exactly 4 files (2 .pack and 2 .idx).
+	ls http_child/.git/objects/pack/* >filelist &&
+	test_line_count = 4 filelist
+'
+
+test_expect_success 'packfile-uri with transfer.fsckobjects fails on bad object' '
+	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	rm -rf "$P" http_child log &&
+
+	git init "$P" &&
+	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
+
+	cat >bogus-commit <<EOF &&
+tree $EMPTY_TREE
+author Bugs Bunny 1234567890 +0000
+committer Bugs Bunny <bugs@bun.ni> 1234567890 +0000
+
+This commit object intentionally broken
+EOF
+	BOGUS=$(git -C "$P" hash-object -t commit -w --stdin <bogus-commit) &&
+	git -C "$P" branch bogus-branch "$BOGUS" &&
+
+	echo my-blob >"$P/my-blob" &&
+	git -C "$P" add my-blob &&
+	git -C "$P" commit -m x &&
+
+	configure_exclusion "$P" my-blob >h &&
+
+	sane_unset GIT_TEST_SIDEBAND_ALL &&
+	test_must_fail git -c protocol.version=2 -c transfer.fsckobjects=1 \
+		-c fetch.uriprotocols=http,https \
+		clone "$HTTPD_URL/smart/http_parent" http_child 2>error &&
+	test_i18ngrep "invalid author/committer line - missing email" error
+'
+
 # DO NOT add non-httpd-specific tests here, because the last part of this
 # test script is only executed when httpd is available and enabled.
 
-- 
2.28.0.220.ged08abb693-goog
Eric Sunshine· Aug 17, 2020, 19:52 UTC · re: Jonathan Tan · lore

Re: [PATCH v2 3/3] fetch-pack: make packfile URIs work with transfer.fsckobjects

On Mon, Aug 17, 2020 at 3:49 PM Jonathan Tan <jonathantanmy@google.com> wrote:
Show 14 quoted lines
> +test_expect_success 'packfile-uri with transfer.fsckobjects fails on bad object' '
> +       P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
> +       rm -rf "$P" http_child log &&
> +
> +       git init "$P" &&
> +       git -C "$P" config "uploadpack.allowsidebandall" "true" &&
> +
> +       cat >bogus-commit <<EOF &&
> +tree $EMPTY_TREE
> +author Bugs Bunny 1234567890 +0000
> +committer Bugs Bunny <bugs@bun.ni> 1234567890 +0000
> +
> +This commit object intentionally broken
> +EOF

The v2 cover letter says that this now uses <<-EOF so the here-doc body can be indented, but that doesn't seem to be the case.

Jonathan Tan· Aug 17, 2020, 20:22 UTC · re: Eric Sunshine · lore

Re: [PATCH v2 3/3] fetch-pack: make packfile URIs work with transfer.fsckobjects

Show 18 quoted lines
> On Mon, Aug 17, 2020 at 3:49 PM Jonathan Tan <jonathantanmy@google.com> wrote:
> > +test_expect_success 'packfile-uri with transfer.fsckobjects fails on bad object' '
> > +       P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
> > +       rm -rf "$P" http_child log &&
> > +
> > +       git init "$P" &&
> > +       git -C "$P" config "uploadpack.allowsidebandall" "true" &&
> > +
> > +       cat >bogus-commit <<EOF &&
> > +tree $EMPTY_TREE
> > +author Bugs Bunny 1234567890 +0000
> > +committer Bugs Bunny <bugs@bun.ni> 1234567890 +0000
> > +
> > +This commit object intentionally broken
> > +EOF
> 
> The v2 cover letter says that this now uses <<-EOF so the here-doc
> body can be indented, but that doesn't seem to be the case.

Ah, good catch. I forgot to amend my commit. If Junio doesn't do it locally then I will send out a v3.

Jonathan Tan· Aug 17, 2020, 19:48 UTC · re: Jonathan Tan · lore

[PATCH v2 2/3] fetch-pack: document only_packfile in get_pack()

dd4b732df7 ("upload-pack: send part of packfile response as uri", 2020-06-10) added the "only_packfile" parameter to get_pack() but did not document it. Add documentation.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 fetch-pack.c | 4 ++++
 1 file changed, 4 insertions(+)
Show changes to fetch-pack.c +4 −0
diff --git a/fetch-pack.c b/fetch-pack.c
index 7f20eca4f8..289121038e 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -794,6 +794,10 @@ static void write_promisor_file(const char *keep_name,
 	strbuf_release(&promisor_name);
 }
 
+/*
+ * Pass 1 as "only_packfile" if the pack received is the only pack in this
+ * fetch request (that is, if there were no packfile URIs provided).
+ */
 static int get_pack(struct fetch_pack_args *args,
 		    int xd[2], struct string_list *pack_lockfiles,
 		    int only_packfile,
-- 
2.28.0.220.ged08abb693-goog
Jonathan Tan· Aug 17, 2020, 19:48 UTC · re: Jonathan Tan · lore

[PATCH v2 1/3] (various): document from_promisor parameter

88e2f9ed8e ("introduce fetch-object: fetch one promisor object", 2017-12-05) plumbed through the from_promisor parameter but did not document it everywhere it appeared. Add the documentation.

(It also plumbed through the no_dependents parameter, but I have left that alone because it is being removed in a commit under review [1].)

[1] https://lore.kernel.org/git/e8f16d69089a5011c355d5939c56fa53b7a1eb2d.1597184949.git.jonathantanmy@google.com/
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 fetch-pack.h  | 8 ++++++++
 remote-curl.c | 3 +++
 transport.h   | 3 +++
 3 files changed, 14 insertions(+)
Show changes to 3 files +14 −0

fetch-pack.h, remote-curl.c, transport.h

diff --git a/fetch-pack.h b/fetch-pack.h
index 85d1e39fe7..5e747daea8 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -40,6 +40,14 @@ struct fetch_pack_args {
 	unsigned cloning:1;
 	unsigned update_shallow:1;
 	unsigned deepen:1;
+
+	/*
+	 * Indicate that the remote of this request is a promisor remote. The
+	 * pack received does not need all referred-to objects to be present in
+	 * the local object store, and fetch-pack will store the pack received
+	 * together with a ".promisor" file indicating that the aforementioned
+	 * pack is a promisor pack.
+	 */
 	unsigned from_promisor:1;
 
 	/*
diff --git a/remote-curl.c b/remote-curl.c
index 62b3a45cde..0c1833dcb6 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -39,7 +39,10 @@ struct options {
 		/* One of the SEND_PACK_PUSH_CERT_* constants. */
 		push_cert : 2,
 		deepen_relative : 1,
+
+		/* see documentation of corresponding flag in fetch-pack.h */
 		from_promisor : 1,
+
 		no_dependents : 1,
 		atomic : 1,
 		object_format : 1;
diff --git a/transport.h b/transport.h
index 1be4013dec..298d9eedc9 100644
--- a/transport.h
+++ b/transport.h
@@ -15,7 +15,10 @@ struct git_transport_options {
 	unsigned self_contained_and_connected : 1;
 	unsigned update_shallow : 1;
 	unsigned deepen_relative : 1;
+
+	/* see documentation of corresponding flag in fetch-pack.h */
 	unsigned from_promisor : 1;
+
 	unsigned no_dependents : 1;
 
 	/*
-- 
2.28.0.220.ged08abb693-goog

← back to recent threads