Commit Graph

336 Commits

Author SHA1 Message Date
Junio C Hamano
eae47db865 Merge branch 'rs/fetch-pack-invalid-lockfile'
"fetch-pack" could pass NULL pointer to unlink(2) when it sees an
invalid filename; the error checking has been tightened to make
this impossible.

* rs/fetch-pack-invalid-lockfile:
  fetch-pack: disregard invalid pack lockfiles
2020-12-08 15:11:20 -08:00
René Scharfe
6031af387e fetch-pack: disregard invalid pack lockfiles
9da69a6539 (fetch-pack: support more than one pack lockfile, 2020-06-10)
started to use a string_list for pack lockfile names instead of a single
string pointer.  It removed a NULL check from transport_unlock_pack() as
well, which is the function that eventually deletes these lockfiles and
releases their name strings.

index_pack_lockfile() can return NULL if it doesn't like the contents it
reads from the file descriptor passed to it.  unlink(2) is declared to
not accept NULL pointers (at least with glibc).  Undefined Behavior
Sanitizer together with Address Sanitizer detects a case where a NULL
lockfile name is passed to unlink(2) by transport_unlock_pack() in t1060
(make SANITIZE=address,undefined; cd t; ./t1060-object-corruption.sh).

Reinstate the NULL check to avoid undefined behavior, but put it right
at the source, so that the number of items in the string_list reflects
the number of valid lockfiles.

Signed-off-by: René Scharfe <l.s.r@web.de>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-30 14:35:00 -08:00
Josh Steadmon
1e905bbc00 fetch-pack: advertise session ID in capabilities
When the server sent a session-id capability and transfer.advertiseSID
is true, advertise fetch-pack's own session ID back to the server.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 18:26:53 -08:00
Junio C Hamano
b4100f366c Merge branch 'jt/lazy-fetch'
Updates to on-demand fetching code in lazily cloned repositories.

* jt/lazy-fetch:
  fetch: no FETCH_HEAD display if --no-write-fetch-head
  fetch-pack: remove no_dependents code
  promisor-remote: lazy-fetch objects in subprocess
  fetch-pack: do not lazy-fetch during ref iteration
  fetch: only populate existing_refs if needed
  fetch: avoid reading submodule config until needed
  fetch: allow refspecs specified through stdin
  negotiator/noop: add noop fetch negotiator
2020-09-03 12:37:04 -07:00
Junio C Hamano
bdccf5e086 Merge branch 'jt/fetch-pack-loosen-validation-with-packfile-uri'
Bugfix for "git fetch" when the packfile URI capability is in use.

* jt/fetch-pack-loosen-validation-with-packfile-uri:
  fetch-pack: make packfile URIs work with transfer.fsckobjects
  fetch-pack: document only_packfile in get_pack()
  (various): document from_promisor parameter
2020-09-03 12:37:01 -07:00
Jonathan Tan
0bd96bea2f 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>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-24 17:34:24 -07:00
Jonathan Tan
ece9aea2c1 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>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-24 17:31:09 -07:00
Jonathan Tan
1b03df5f1e fetch-pack: in partial clone, pass --promisor
When fetching a pack from a promisor remote, the corresponding .promisor
file needs to be created. "fetch-pack" originally did this by passing
"--promisor" to "index-pack", but in 5374a290aa ("fetch-pack: write
fetched refs to .promisor", 2019-10-16), "fetch-pack" was taught to do
this itself instead, because it needed to store ref information in the
.promisor file.

This causes a problem with superprojects when transfer.fsckobjects is
set, because in the current implementation, it is "index-pack" that
calls fsck_finish() to check the objects; before 5374a290aa,
fsck_finish() would see that .gitmodules is a promisor object and
tolerate it being missing, but after, there is no .promisor file (at the
time of the invocation of fsck_finish() by "index-pack") to tell it that
.gitmodules is a promisor object, so it returns an error.

Therefore, teach "fetch-pack" to pass "--promisor" to index pack once
again. "fetch-pack" will subsequently overwrite this file with the ref
information.

An alternative is to instead move object checking to "fetch-pack", and
let "index-pack" only index the files. However, since "index-pack" has
to inflate objects in order to index them, it seems reasonable to also
let it check the objects (which also require inflated files).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-20 13:18:27 -07:00
Jonathan Tan
9dfa8dbeee fetch-pack: remove no_dependents code
Now that Git has switched to using a subprocess to lazy-fetch missing
objects, remove the no_dependents code as it is no longer used.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 16:46:53 -07:00
Jonathan Tan
5c3b801dab fetch-pack: do not lazy-fetch during ref iteration
In order to determine negotiation tips, "fetch-pack" iterates over all
refs and dereferences all annotated tags found. This causes the
existence of targets of refs and annotated tags to be checked. Avoiding
this is especially important when we use "git fetch" (which invokes
"fetch-pack") to perform lazy fetches in a partial clone because a
target of such a ref or annotated tag may need to be itself lazy-fetched
(and otherwise causing an infinite loop).

Therefore, teach "fetch-pack" not to lazy fetch whenever iterating over
refs. This is done by using the raw form of ref iteration and by
dereferencing tags ourselves.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 13:25:05 -07:00
Jeff King
f6d8942b1f strvec: fix indentation in renamed calls
Code which split an argv_array call across multiple lines, like:

  argv_array_pushl(&args, "one argument",
                   "another argument", "and more",
		   NULL);

was recently mechanically renamed to use strvec, which results in
mis-matched indentation like:

  strvec_pushl(&args, "one argument",
                   "another argument", "and more",
		   NULL);

Let's fix these up to align the arguments with the opening paren. I did
this manually by sifting through the results of:

  git jump grep 'strvec_.*,$'

and liberally applying my editor's auto-format. Most of the changes are
of the form shown above, though I also normalized a few that had
originally used a single-tab indentation (rather than our usual style of
aligning with the open paren). I also rewrapped a couple of obvious
cases (e.g., where previously too-long lines became short enough to fit
on one), but I wasn't aggressive about it. In cases broken to three or
more lines, the grouping of arguments is sometimes meaningful, and it
wasn't worth my time or reviewer time to ponder each case individually.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Jeff King
ef8d7ac42a strvec: convert more callers away from argv_array name
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).

This patch converts remaining files from the first half of the alphabet,
to keep the diff to a manageable size.

The conversion was done purely mechanically with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe '
    s/ARGV_ARRAY/STRVEC/g;
    s/argv_array/strvec/g;
  '

and then selectively staging files with "git add '[abcdefghjkl]*'".
We'll deal with any indentation/style fallouts separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Junio C Hamano
12210859da Merge branch 'bc/sha-256-part-2'
SHA-256 migration work continues.

* bc/sha-256-part-2: (44 commits)
  remote-testgit: adapt for object-format
  bundle: detect hash algorithm when reading refs
  t5300: pass --object-format to git index-pack
  t5704: send object-format capability with SHA-256
  t5703: use object-format serve option
  t5702: offer an object-format capability in the test
  t/helper: initialize the repository for test-sha1-array
  remote-curl: avoid truncating refs with ls-remote
  t1050: pass algorithm to index-pack when outside repo
  builtin/index-pack: add option to specify hash algorithm
  remote-curl: detect algorithm for dumb HTTP by size
  builtin/ls-remote: initialize repository based on fetch
  t5500: make hash independent
  serve: advertise object-format capability for protocol v2
  connect: parse v2 refs with correct hash algorithm
  connect: pass full packet reader when parsing v2 refs
  Documentation/technical: document object-format for protocol v2
  t1302: expect repo format version 1 for SHA-256
  builtin/show-index: provide options to determine hash algo
  t5302: modernize test formatting
  ...
2020-07-06 22:09:13 -07:00
Junio C Hamano
34e849b05a Merge branch 'jt/cdn-offload'
The "fetch/clone" protocol has been updated to allow the server to
instruct the clients to grab pre-packaged packfile(s) in addition
to the packed object data coming over the wire.

* jt/cdn-offload:
  upload-pack: fix a sparse '0 as NULL pointer' warning
  upload-pack: send part of packfile response as uri
  fetch-pack: support more than one pack lockfile
  upload-pack: refactor reading of pack-objects out
  Documentation: add Packfile URIs design doc
  Documentation: order protocol v2 sections
  http-fetch: support fetching packfiles by URL
  http-fetch: refactor into function
  http: refactor finish_http_pack_request()
  http: use --stdin when indexing dumb HTTP pack
2020-06-25 12:27:47 -07:00
Jonathan Tan
dd4b732df7 upload-pack: send part of packfile response as uri
Teach upload-pack to send part of its packfile response as URIs.

An administrator may configure a repository with one or more
"uploadpack.blobpackfileuri" lines, each line containing an OID, a pack
hash, and a URI. A client may configure fetch.uriprotocols to be a
comma-separated list of protocols that it is willing to use to fetch
additional packfiles - this list will be sent to the server. Whenever an
object with one of those OIDs would appear in the packfile transmitted
by upload-pack, the server may exclude that object, and instead send the
URI. The client will then download the packs referred to by those URIs
before performing the connectivity check.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-10 18:06:34 -07:00
Jonathan Tan
9da69a6539 fetch-pack: support more than one pack lockfile
Whenever a fetch results in a packfile being downloaded, a .keep file is
generated, so that the packfile can be preserved (from, say, a running
"git repack") until refs are written referring to the contents of the
packfile.

In a subsequent patch, a successful fetch using protocol v2 may result
in more than one .keep file being generated. Therefore, teach
fetch_pack() and the transport mechanism to support multiple .keep
files.

Implementation notes:

 - builtin/fetch-pack.c normally does not generate .keep files, and thus
   is unaffected by this or future changes. However, it has an
   undocumented "--lock-pack" feature, used by remote-curl.c when
   implementing the "fetch" remote helper command. In keeping with the
   remote helper protocol, only one "lock" line will ever be written;
   the rest will result in warnings to stderr. However, in practice,
   warnings will never be written because the remote-curl.c "fetch" is
   only used for protocol v0/v1 (which will not generate multiple .keep
   files). (Protocol v2 uses the "stateless-connect" command, not the
   "fetch" command.)

 - connected.c has an optimization in that connectivity checks on a ref
   need not be done if the target object is in a pack known to be
   self-contained and connected. If there are multiple packfiles, this
   optimization can no longer be done.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-10 18:06:34 -07:00
brian m. carlson
4b831208bb fetch-pack: parse and advertise the object-format capability
Parse the server's object-format capability and respond accordingly,
dying if there is a mismatch.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-27 10:07:06 -07:00
brian m. carlson
48bf141589 fetch-pack: detect when the server doesn't support our hash
Detect when the server doesn't support our hash algorithm and abort.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-27 10:07:06 -07:00
Denton Liu
b0df0c16ea stateless-connect: send response end packet
Currently, remote-curl acts as a proxy and blindly forwards packets
between an HTTP server and fetch-pack. In the case of a stateless RPC
connection where the connection is terminated before the transaction is
complete, remote-curl will blindly forward the packets before waiting on
more input from fetch-pack. Meanwhile, fetch-pack will read the
transaction and continue reading, expecting more input to continue the
transaction. This results in a deadlock between the two processes.

This can be seen in the following command which does not terminate:

	$ git -c protocol.version=2 clone https://github.com/git/git.git --shallow-since=20151012
	Cloning into 'git'...

whereas the v1 version does terminate as expected:

	$ git -c protocol.version=1 clone https://github.com/git/git.git --shallow-since=20151012
	Cloning into 'git'...
	fatal: the remote end hung up unexpectedly

Instead of blindly forwarding packets, make remote-curl insert a
response end packet after proxying the responses from the remote server
when using stateless_connect(). On the RPC client side, ensure that each
response ends as described.

A separate control packet is chosen because we need to be able to
differentiate between what the remote server sends and remote-curl's
control packets. By ensuring in the remote-curl code that a server
cannot send response end packets, we prevent a malicious server from
being able to perform a denial of service attack in which they spoof a
response end packet and cause the described deadlock to happen.

Reported-by: Force Charlie <charlieio@outlook.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-24 16:26:00 -07:00
Junio C Hamano
896833b268 Merge branch 'tb/shallow-cleanup'
Code cleanup.

* tb/shallow-cleanup:
  shallow: use struct 'shallow_lock' for additional safety
  shallow.h: document '{commit,rollback}_shallow_file'
  shallow: extract a header file for shallow-related functions
  commit: make 'commit_graft_pos' non-static
2020-05-13 12:19:18 -07:00
Junio C Hamano
0b07eecf6e Merge branch 'jt/v2-fetch-nego-fix'
The upload-pack protocol v2 gave up too early before finding a
common ancestor, resulting in a wasteful fetch from a fork of a
project.  This has been corrected to match the behaviour of v0
protocol.

* jt/v2-fetch-nego-fix:
  fetch-pack: in protocol v2, reset in_vain upon ACK
  fetch-pack: in protocol v2, in_vain only after ACK
  fetch-pack: return enum from process_acks()
2020-05-01 13:40:00 -07:00
Junio C Hamano
2b4ff3d3dc Merge branch 'tb/reset-shallow'
Fix in-core inconsistency after fetching into a shallow repository
that broke the code to write out commit-graph.

* tb/reset-shallow:
  shallow.c: use '{commit,rollback}_shallow_file'
  t5537: use test_write_lines and indented heredocs for readability
2020-05-01 13:39:51 -07:00
Taylor Blau
cac4b8e22e shallow: use struct 'shallow_lock' for additional safety
In previous patches, the functions 'commit_shallow_file' and
'rollback_shallow_file' were introduced to reset the shallowness
validity checks on a repository after potentially modifying
'.git/shallow'.

These functions can be made safer by wrapping the 'struct lockfile *' in
a new type, 'shallow_lock', so that they cannot be called with a raw
lock (and potentially misused by other code that happens to possess a
lockfile, but has nothing to do with shallowness).

This patch introduces that type as a thin wrapper around 'struct
lockfile', and updates the two aforementioned functions and their
callers to use it.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-30 14:19:13 -07:00
Taylor Blau
120ad2b0f1 shallow: extract a header file for shallow-related functions
There are many functions in commit.h that are more related to shallow
repositories than they are to any sort of generic commit machinery.
Likely this began when there were only a few shallow-related functions,
and commit.h seemed a reasonable enough place to put them.

But, now there are a good number of shallow-related functions, and
placing them all in 'commit.h' doesn't make sense.

This patch extracts a 'shallow.h', which takes all of the declarations
from 'commit.h' for functions which already exist in 'shallow.c'. We
will bring the remaining shallow-related functions defined in 'commit.c'
in a subsequent patch.

For now, move only the ones that already are implemented in 'shallow.c',
and update the necessary includes.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-30 14:19:13 -07:00
Jonathan Tan
2f0a093dd6 fetch-pack: in protocol v2, reset in_vain upon ACK
In the function process_acks() in fetch-pack.c, the variable
received_ack is meant to track that an ACK was received, but it was
never set. This results in negotiation terminating prematurely through
the in_vain counter, when the counter should have been reset upon every
ACK.

Therefore, reset the in_vain counter upon every ACK.

Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-28 09:55:06 -07:00
Jonathan Tan
4fa3f00abb fetch-pack: in protocol v2, in_vain only after ACK
When fetching, Git stops negotiation when it has sent at least
MAX_IN_VAIN (which is 256) "have" lines without having any of them
ACK-ed. But this is supposed to trigger only after the first ACK, as
pack-protocol.txt says:

  However, the 256 limit *only* turns on in the canonical client
  implementation if we have received at least one "ACK %s continue"
  during a prior round.  This helps to ensure that at least one common
  ancestor is found before we give up entirely.

The code path for protocol v0 observes this, but not protocol v2,
resulting in shorter negotiation rounds but significantly larger
packfiles. Teach the code path for protocol v2 to check this criterion
only after at least one ACK was received.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-28 09:55:02 -07:00
Jonathan Tan
d1185aa6fa fetch-pack: return enum from process_acks()
process_acks() returns 0, 1, or 2, depending on whether "ready" was
received and if not, whether at least one commit was found to be common.
Replace these magic numbers with a documented enum.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-28 09:54:48 -07:00
Taylor Blau
37b9dcabfc shallow.c: use '{commit,rollback}_shallow_file'
In bd0b42aed3 (fetch-pack: do not take shallow lock unnecessarily,
2019-01-10), the author noted that 'is_repository_shallow' produces
visible side-effect(s) by setting 'is_shallow' and 'shallow_stat'.

This is a problem for e.g., fetching with '--update-shallow' in a
shallow repository with 'fetch.writeCommitGraph' enabled, since the
update to '.git/shallow' will cause Git to think that the repository
isn't shallow when it is, thereby circumventing the commit-graph
compatibility check.

This causes problems in shallow repositories with at least shallow refs
that have at least one ancestor (since the client won't have those
objects, and therefore can't take the reachability closure over commits
when writing a commit-graph).

Address this by introducing thin wrappers over 'commit_lock_file' and
'rollback_lock_file' for use specifically when the lock is held over
'.git/shallow'. These wrappers (appropriately called
'commit_shallow_file' and 'rollback_shallow_file') call into their
respective functions in 'lockfile.h', but additionally reset validity
checks used by the shallow machinery.

Replace each instance of 'commit_lock_file' and 'rollback_lock_file'
with 'commit_shallow_file' and 'rollback_shallow_file' when the lock
being held is over the '.git/shallow' file.

As a result, 'prune_shallow' can now only be called once (since
'check_shallow_file_for_update' will die after calling
'reset_repository_shallow'). But, this is OK since we only call
'prune_shallow' at most once per process.

Helped-by: Jonathan Tan <jonathantanmy@google.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-24 13:56:39 -07:00
Jeff King
fe299ec5ae oid_array: rename source file from sha1-array
We renamed the actual data structure in 910650d2f8 (Rename sha1_array to
oid_array, 2017-03-31), but the file is still called sha1-array. Besides
being slightly confusing, it makes it more annoying to grep for leftover
occurrences of "sha1" in various files, because the header is included
in so many places.

Let's complete the transition by renaming the source and header files
(and fixing up a few comment references).

I kept the "-" in the name, as that seems to be our style; cf.
fc1395f4a4 (sha1_file.c: rename to use dash in file name, 2018-04-10).
We also have oidmap.h and oidset.h without any punctuation, but those
are "struct oidmap" and "struct oidset" in the code. We _could_ make
this "oidarray" to match, but somehow it looks uglier to me because of
the length of "array" (plus it would be a very invasive patch for little
gain).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-30 10:59:08 -07:00
Junio C Hamano
76c68246c6 Merge branch 'ec/fetch-mark-common-refs-trace2'
Trace2 annotation.

* ec/fetch-mark-common-refs-trace2:
  fetch: add trace2 instrumentation
2019-12-05 12:52:44 -08:00
Junio C Hamano
fce9e836d3 Merge branch 'jt/fetch-remove-lazy-fetch-plugging'
"git fetch" codepath had a big "do not lazily fetch missing objects
when I ask if something exists" switch.  This has been corrected by
marking the "does this thing exist?" calls with "if not please do not
lazily fetch it" flag.

* jt/fetch-remove-lazy-fetch-plugging:
  promisor-remote: remove fetch_if_missing=0
  clone: remove fetch_if_missing=0
  fetch: remove fetch_if_missing=0
2019-12-01 09:04:38 -08:00
Erik Chen
9e5afdf997 fetch: add trace2 instrumentation
Add trace2 regions to fetch-pack.c to better track time spent in the various
phases of a fetch:

    * parsing remote refs and finding a cutoff
    * marking local refs as complete
    * marking complete remote refs as common

All stages could potentially be slow for repositories with many refs.

Signed-off-by: Erik Chen <erikchen@chromium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-20 10:06:40 +09:00
Jonathan Tan
603960b50e promisor-remote: remove fetch_if_missing=0
Commit 6462d5eb9a ("fetch: remove fetch_if_missing=0", 2019-11-08)
strove to remove the need for fetch_if_missing=0 from the fetching
mechanism, so it is plausible to attempt removing fetch_if_missing=0
from the lazy-fetching mechanism in promisor-remote as well.

But doing so reveals a bug - when the server does not send an object
pointed to by a tag object, an infinite loop occurs: Git attempts to
fetch the missing object, which causes a deferencing of all refs (for
negotiation), which causes a lazy fetch of that missing object, and so
on. This bug is because of unnecessary use of the fetch negotiator
during lazy fetching - it is not used after initialization, but it is
still initialized (which causes the dereferencing of all refs).

Thus, when the negotiator is not used during fetching, refrain from
initializing it. Then, remove fetch_if_missing from promisor-remote.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-13 11:50:58 +09:00
Junio C Hamano
026587c793 Merge branch 'jt/fetch-pack-record-refs-in-the-dot-promisor'
Debugging support for lazy cloning has been a bit improved.

* jt/fetch-pack-record-refs-in-the-dot-promisor:
  fetch-pack: write fetched refs to .promisor
2019-11-10 18:02:10 +09:00
Jonathan Tan
6462d5eb9a fetch: remove fetch_if_missing=0
In fetch_pack() (and all functions it calls), pass
OBJECT_INFO_SKIP_FETCH_OBJECT whenever we query an object that could be
a tree or blob that we do not want to be lazy-fetched even if it is
absent. Thus, the only lazy-fetches occurring for trees and blobs are
when resolving deltas.

Thus, we can remove fetch_if_missing=0 from builtin/fetch.c. Remove
this, and also add a test ensuring that such objects are not
lazy-fetched. (We might be able to remove fetch_if_missing=0 from other
places too, but I have limited myself to builtin/fetch.c in this commit
because I have not written tests for the other commands yet.)

Note that commits and tags may still be lazy-fetched. I limited myself
to objects that could be trees or blobs here because Git does not
support creating such commit- and tag-excluding clones yet, and even if
such a clone were manually created, Git does not have good support for
fetching a single commit (when fetching a commit, it and all its
ancestors would be sent).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-08 15:26:44 +09:00
Jonathan Tan
5374a290aa fetch-pack: write fetched refs to .promisor
The specification of promisor packfiles (in partial-clone.txt) states
that the .promisor files that accompany packfiles do not matter (just
like .keep files), so whenever a packfile is fetched from the promisor
remote, Git has been writing empty .promisor files. But these files
could contain more useful information.

So instead of writing empty files, write the refs fetched to these
files. This makes it easier to debug issues with partial clones, as we
can identify what refs (and their associated hashes) were fetched at the
time the packfile was downloaded, and if necessary, compare those hashes
against what the promisor remote reports now.

This is implemented by teaching fetch-pack to write its own non-empty
.promisor file whenever it knows the name of the pack's lockfile. This
covers the case wherein the user runs "git fetch" with an internal
protocol or HTTP protocol v2 (fetch_refs_via_pack() in transport.c sets
lock_pack) and with HTTP protocol v0/v1 (fetch_git() in remote-curl.c
passes "--lock-pack" to "fetch-pack").

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Acked-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-16 11:07:51 +09:00
Junio C Hamano
3b9ec27919 Merge branch 'js/trace2-fetch-push'
Dev support.

* js/trace2-fetch-push:
  transport: push codepath can take arbitrary repository
  push: add trace2 instrumentation
  fetch: add trace2 instrumentation
2019-10-15 13:48:03 +09:00
Junio C Hamano
676278f8ea Merge branch 'bc/object-id-part17'
Preparation for SHA-256 upgrade continues.

* bc/object-id-part17: (26 commits)
  midx: switch to using the_hash_algo
  builtin/show-index: replace sha1_to_hex
  rerere: replace sha1_to_hex
  builtin/receive-pack: replace sha1_to_hex
  builtin/index-pack: replace sha1_to_hex
  packfile: replace sha1_to_hex
  wt-status: convert struct wt_status to object_id
  cache: remove null_sha1
  builtin/worktree: switch null_sha1 to null_oid
  builtin/repack: write object IDs of the proper length
  pack-write: use hash_to_hex when writing checksums
  sequencer: convert to use the_hash_algo
  bisect: switch to using the_hash_algo
  sha1-lookup: switch hard-coded constants to the_hash_algo
  config: use the_hash_algo in abbrev comparison
  combine-diff: replace GIT_SHA1_HEXSZ with the_hash_algo
  bundle: switch to use the_hash_algo
  connected: switch GIT_SHA1_HEXSZ to the_hash_algo
  show-index: switch hard-coded constants to the_hash_algo
  blame: remove needless comparison with GIT_SHA1_HEXSZ
  ...
2019-10-11 14:24:46 +09:00
Josh Steadmon
5fc31180d8 fetch: add trace2 instrumentation
Add trace2 regions to fetch-pack.c and builtins/fetch.c to better track
time spent in the various phases of a fetch:

* listing refs
* negotiation for protocol versions v0-v2
* fetching refs
* consuming refs

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-03 10:13:17 +09:00
Junio C Hamano
627b826834 Merge branch 'md/list-objects-filter-combo'
The list-objects-filter API (used to create a sparse/lazy clone)
learned to take a combined filter specification.

* md/list-objects-filter-combo:
  list-objects-filter-options: make parser void
  list-objects-filter-options: clean up use of ALLOC_GROW
  list-objects-filter-options: allow mult. --filter
  strbuf: give URL-encoding API a char predicate fn
  list-objects-filter-options: make filter_spec a string_list
  list-objects-filter-options: move error check up
  list-objects-filter: implement composite filters
  list-objects-filter-options: always supply *errbuf
  list-objects-filter: put omits set in filter struct
  list-objects-filter: encapsulate filter components
2019-09-18 11:50:09 -07:00
brian m. carlson
f6af19a9ad fetch-pack: use parse_oid_hex
Instead of hard-coding constants, use parse_oid_hex to compute a pointer
and use it in further parsing operations.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-19 15:04:57 -07:00
Derrick Stolee
aaf633c2ad repo-settings: create feature.experimental setting
The 'feature.experimental' setting includes config options that are
not committed to become defaults, but could use additional testing.

Update the following config settings to take new defaults, and to
use the repo_settings struct if not already using them:

* 'pack.useSparse=true'

* 'fetch.negotiationAlgorithm=skipping'

In the case of fetch.negotiationAlgorithm, the existing logic
would load the config option only when about to use the setting,
so had a die() statement on an unknown string value. This is
removed as now the config is parsed under prepare_repo_settings().
In general, this die() is probably misplaced and not valuable.
A test was removed that checked this die() statement executed.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-13 13:33:55 -07:00
Junio C Hamano
b49d337bfb Merge branch 'nd/fetch-capability-tweak'
Protocol capabilities that go over wire should never be translated,
but it was incorrectly marked for translation, which has been
corrected.  The output of protocol capabilities for debugging has
been tweaked a bit.

* nd/fetch-capability-tweak:
  fetch-pack: print server version at the top in -v -v
  fetch-pack: print all relevant supported capabilities with -v -v
  fetch-pack: move capability names out of i18n strings
2019-07-09 15:25:43 -07:00
Matthew DeVore
cf9ceb5a12 list-objects-filter-options: make filter_spec a string_list
Make the filter_spec string a string_list rather than a raw C string.
The list of strings must be concatted together to make a complete
filter_spec. A future patch will use this capability to build "combine:"
filter specs gradually.

A strbuf would seem to be a more natural choice for this object, but it
unfortunately requires initialization besides just zero'ing out the
memory.  This results in all container structs, and all containers of
those structs, etc., to also require initialization. Initializing them
all would be more cumbersome that simply using a string_list, which
behaves properly when its contents are zero'd.

For the purposes of code simplification, change behavior in how filter
specs are conveyed over the protocol: do not normalize the tree:<depth>
filter specs since there should be no server in existence that supports
tree:# but not tree:#k etc.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-28 08:41:53 -07:00
Nguyễn Thái Ngọc Duy
0e04297101 fetch-pack: print server version at the top in -v -v
Before the previous patch, the server version is printed after all the
"Server supports" lines. The previous one puts the version in the middle
of "Server supports" group.

Instead of moving it to the bottom, I move it to the top. Version may
stand out more at the top as we will have even more debug out after
capabilities.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 14:01:00 -07:00
Nguyễn Thái Ngọc Duy
5a88583b0b fetch-pack: print all relevant supported capabilities with -v -v
When we check if some capability is supported, we do print something in
verbose mode. Some capabilities are not printed though (and it made me
think it's not supported; I was more used to GIT_TRACE_PACKET) so let's
print them all.

It's a bit more code. And one could argue for printing all supported
capabilities the server sends us. But I think it's still valuable this
way because we see the capabilities that the client cares about.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 14:00:59 -07:00
Nguyễn Thái Ngọc Duy
0778b2931c fetch-pack: move capability names out of i18n strings
This reduces the work on translators since they only have one string to
translate (and I think it's still enough context to translate). It also
makes sure no capability name is translated by accident.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 14:00:59 -07:00
Jeff King
d0229abd93 object: convert lookup_object() to use object_id
There are no callers left of lookup_object() that aren't just passing us
the "hash" member of a "struct object_id". Let's take the whole struct,
which gets us closer to removing all raw sha1 variables.  It also
matches the existing conversions of lookup_blob(), etc.

The conversions of callers were done by hand, but they're all mechanical
one-liners.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:18:09 -07:00
Junio C Hamano
0e5387cd02 Merge branch 'jt/clone-server-option'
A brown-paper-bag bugfix to a change already in 'master'.

* jt/clone-server-option:
  fetch-pack: send server options after command
2019-05-30 10:50:46 -07:00
Jonathan Tan
5b204b7df3 fetch-pack: send server options after command
Currently, if any server options are specified during a protocol v2
fetch, server options will be sent before "command=fetch". Write server
options to the request buffer in send_fetch_request() so that the
components of the request are sent in the correct order.

The protocol documentation states that the command must come first. The
Git server implementation in serve.c (see process_request() in that
file) tolerates any order of command and capability, which is perhaps
why we haven't noticed this. This was noticed when testing against a
JGit server implementation, which follows the documentation in this
regard.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Acked-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-28 11:01:07 -07:00