kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
Jeff King	2a4aed42ec	fetch-pack: ignore SIGPIPE when writing to index-pack When fetching, we send the incoming pack to index-pack (or unpack-objects) via the sideband demuxer. If index-pack hits an error (e.g., because an object fails fsck), then it will die immediately. This may cause us to get SIGPIPE on the fetch, as we're still trying to write pack contents from the sideband demuxer (which is typically a thread, and thus takes down the whole fetch process). You can see this in action with: ./t5702-protocol-v2.sh --stress --run=59 which ends with (wrapped for readability): test_must_fail: died by signal 13: git -c protocol.version=2 \ -c transfer.fsckobjects=1 -c fetch.uriprotocols=http,https \ clone http://127.0.0.1:5708/smart/http_parent http_child not ok 59 - packfile-uri with transfer.fsckobjects fails on bad object This is mostly cosmetic. The actual error of interest (in this case, the object that failed the fsck check) comes from index-pack straight to stderr, so the user still sees it. They _might_ even see fetch-pack complaining about index-pack failing, because the main thread is racing with the sideband-demuxer. But they'll definitely see the signal death in the exit code, which is what the test is complaining about. We can make this more predictable by just ignoring SIGPIPE. The sideband demuxer uses write_or_die(), so it will notice and stop (gracefully, because we hook die_routine() to exit just the thread). And during this section we're not writing anywhere else where we'd be concerned about SIGPIPE preventing us from wasting effort writing to nowhere. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ivan Frade	88e9b1e3fc	fetch-pack: redact packfile urls in traces In some setups, packfile uris act as bearer token. It is not recommended to expose them plainly in logs, although in special circunstances (e.g. debug) it makes sense to write them. Redact the packfile URL paths by default, unless the GIT_TRACE_REDACT variable is set to false. This mimics the redacting of the Authorization header in HTTP. Signed-off-by: Ivan Frade <ifrade@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Patrick Steinhardt	62b5a35a33	fetch-pack: optimize loading of refs via commit graph In order to negotiate a packfile, we need to dereference refs to see which commits we have in common with the remote. To do so, we first look up the object's type -- if it's a tag, we peel until we hit a non-tag object. If we hit a commit eventually, then we return that commit. In case the object ID points to a commit directly, we can avoid the initial lookup of the object type by opportunistically looking up the commit via the commit-graph, if available, which gives us a slight speed bump of about 2% in a huge repository with about 2.3M refs: Benchmark #1: HEAD~: git-fetch Time (mean ± σ): 31.634 s ± 0.258 s [User: 28.400 s, System: 5.090 s] Range (min … max): 31.280 s … 31.896 s 5 runs Benchmark #2: HEAD: git-fetch Time (mean ± σ): 31.129 s ± 0.543 s [User: 27.976 s, System: 5.056 s] Range (min … max): 30.172 s … 31.479 s 5 runs Summary 'HEAD: git-fetch' ran 1.02 ± 0.02 times faster than 'HEAD~: git-fetch' In case this fails, we fall back to the old code which peels the objects to a commit. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Patrick Steinhardt	9fec7b2130	connected: refactor iterator to return next object ID directly The object ID iterator used by the connectivity checks returns the next object ID via an out-parameter and then uses a return code to indicate whether an item was found. This is a bit roundabout: instead of a separate error code, we can just return the next object ID directly and use `NULL` pointers as indicator that the iterator got no items left. Furthermore, this avoids a copy of the object ID. Refactor the iterator and all its implementations to return object IDs directly. This brings a tiny performance improvement when doing a mirror-fetch of a repository with about 2.3M refs: Benchmark #1: 328dc58b49919c43897240f2eabfa30be2ce32a4~: git-fetch Time (mean ± σ): 30.110 s ± 0.148 s [User: 27.161 s, System: 5.075 s] Range (min … max): 29.934 s … 30.406 s 10 runs Benchmark #2: 328dc58b49919c43897240f2eabfa30be2ce32a4: git-fetch Time (mean ± σ): 29.899 s ± 0.109 s [User: 26.916 s, System: 5.104 s] Range (min … max): 29.696 s … 29.996 s 10 runs Summary '328dc58b49919c43897240f2eabfa30be2ce32a4: git-fetch' ran 1.01 ± 0.01 times faster than '328dc58b49919c43897240f2eabfa30be2ce32a4~: git-fetch' While this 1% speedup could be labelled as statistically insignificant, the speedup is consistent on my machine. Furthermore, this is an end to end test, so it is expected that the improvement in the connectivity check itself is more significant. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Patrick Steinhardt	3e5e6c6e94	fetch-pack: speed up loading of refs via commit graph When doing reference negotiation, git-fetch-pack(1) is loading all refs from disk in order to determine which commits it has in common with the remote repository. This can be quite expensive in repositories with many references though: in a real-world repository with around 2.2 million refs, fetching a single commit by its ID takes around 44 seconds. Dominating the loading time is decompression and parsing of the objects which are referenced by commits. Given the fact that we only care about commits (or tags which can be peeled to one) in this context, there is thus an easy performance win by switching the parsing logic to make use of the commit graph in case we have one available. Like this, we avoid hitting the object database to parse these commits but instead only load them from the commit-graph. This results in a significant performance boost when executing git-fetch in said repository with 2.2 million refs: Benchmark #1: HEAD~: git fetch $remote $commit Time (mean ± σ): 44.168 s ± 0.341 s [User: 42.985 s, System: 1.106 s] Range (min … max): 43.565 s … 44.577 s 10 runs Benchmark #2: HEAD: git fetch $remote $commit Time (mean ± σ): 19.498 s ± 0.724 s [User: 18.751 s, System: 0.690 s] Range (min … max): 18.629 s … 20.454 s 10 runs Summary 'HEAD: git fetch $remote $commit' ran 2.27 ± 0.09 times faster than 'HEAD~: git fetch $remote $commit' Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jeff King	ae1a7eefff	fetch-pack: signal v2 server that we are done making requests When fetching with the v0 protocol over ssh (or a local upload-pack with pipes), the server closes the connection as soon as it is finished sending the pack. So even though the client may still be operating on the data via index-pack (e.g., resolving deltas, checking connectivity, etc), the server has released all resources. With the v2 protocol, however, the server considers the ssh session only as a transport, with individual requests coming over it. After sending the pack, it goes back to its main loop, waiting for another request to come from the client. As a result, the ssh session hangs around until the client process ends, which may be much later (because resolving deltas, etc, may consume a lot of CPU). This is bad for two reasons: - it's consuming resources on the server to leave open a connection that won't see any more use - if something bad happens to the ssh connection in the meantime (say, it gets killed by the network because it's idle, as happened in a real-world report), then ssh will exit non-zero, and we'll propagate the error up the stack. The server is correct here not to hang up after serving the pack. The v2 protocol's design is meant to allow multiple requests like this, and hanging up would be the wrong thing for a hypothetical client which was planning to make more requests (though in practice, the git.git client never would, and I doubt any other implementations would either). The right thing is instead for the client to signal to the server that it's not interested in making more requests. We can do that by closing the pipe descriptor we use to write to ssh. This will propagate to the server upload-pack as an EOF when it tries to read the next request (and then it will close its half, and the whole connection will go away). It's important to do this "half duplex" shutdown, because we have to do it _before_ we actually receive the pack. This is an artifact of the way fetch-pack and index-pack (or unpack-objects) interact. We hand the connection off to index-pack (really, a sideband demuxer which feeds it), and then wait until it returns. And it doesn't do that until it has resolved all of the deltas in the pack, even though it was done reading from the server long before. So just closing the connection fully after index-pack returns would be too late; we'd have held it open much longer than was necessary. And teaching index-pack to close the connection is awkward. It's not even seeing the whole conversation (the sideband demuxer is, but it doesn't actually know what's in the packets, or when the end comes). Note that this close() is happening deep within the transport code. It's possible that a caller would want to perform other operations over the same ssh transport after receiving the pack. But as of the current code, none of the callers do, and there haven't been discussions of any plans to change this. If we need to support that later, we can probably do so by passing down a flag for "you're the last request on the transport; it's OK to close" instead of the code just assuming that's true. The description above all discusses v2 ssh, so it's worth thinking about how this interacts with other protocols: - in v0 protocols, we could do the same half-duplex shutdown (it just goes into the v0 do_fetch_pack() instead). This does work, but since it doesn't have the same persistence problem in the first place, there's little reason to change it at this point. - local fetches against git-upload-pack on the same machine will behave the same as ssh (they are talking over two pipes, and see EOF on their input pipe) - fetches against git-daemon will run this same code, and close one of the descriptors. In practice, this won't do anything, since there our two descriptors are dups of each other, and not part of a half-duplex pair. The right thing would probably be to call shutdown(SHUT_WR) on it. I didn't bother with that here. It doesn't face the same error-code problem (since it's just a TCP connection), so it's really only an optimization problem. And git:// is not that widely used these days, and has less impact on server resources than an ssh termination. - v2 http doesn't suffer from this problem in the first place, as our pipes terminate at a local git-remote-https, which is passing data along as individual requests via curl. Probably curl is keeping the TCP/TLS connection open for more requests, and we might be able to tell it manually "hey, we are done making requests now". But I think that's much less important. It again doesn't suffer from the error-code problem, and HTTP keepalive is pretty well understood (importantly, the timeouts can be set low, because clients like curl know how to reconnect for subsequent requests if necessary). So it's probably not worth figuring out how to tell curl that we're done (though if we do, this patch is probably the first step anyway; fetch-pack closes the pipe back to remote-https, which would be the signal that it should tell curl we're done). The code is pretty straightforward. We close the pipe at the right moment, and set it to -1 to mark it as invalid. I modified the later cleanup code to avoid calling close(-1). That's not strictly necessary, since close(-1) is a noop, but hopefully makes things a bit more obvious to a reader. I suspect that trying to call more transport functions after the close() (e.g., calling transport_fetch_refs() again) would fail, as it's not smart enough to realize we need to re-open the ssh connection. But that's already true when v0 is in use. And no current callers want to do that (and again, the solution is probably a flag in the transport code to keep things open, which can be added later). There's no test here, as the situation it covers is inherently racy (the question is when upload-pack exits, compared to when index-pack finishes resolving deltas and exits). The rather gross shell snippet below does recreate the problematic situation; when run on a sufficiently-large repository (git.git works fine), it kills an "idle" upload-pack while the client is resolving deltas, leading to a failed clone. ( git clone --no-local --progress . foo.git 2>&1 echo >&2 "clone exit code=$?" ) \| tr '\r' '\n' \| while read line do case "$done,$line" in ,Resolving*) echo "hit resolving deltas; killing upload-pack" killall -9 git-upload-pack done=t ;; esac done Reported-by: Greg Pflaum <greg.pflaum@pnp-hcl.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	9c1e657a8f	fetch: teach independent negotiation (no packfile) Currently, the packfile negotiation step within a Git fetch cannot be done independent of sending the packfile, even though there is at least one application wherein this is useful. Therefore, make it possible for this negotiation step to be done independently. A subsequent commit will use this for one such application - push negotiation. This feature is for protocol v2 only. (An implementation for protocol v0 would require a separate implementation in the fetch, transport, and transport helper code.) In the protocol, the main hindrance towards independent negotiation is that the server can unilaterally decide to send the packfile. This is solved by a "wait-for-done" argument: the server will then wait for the client to say "done". In practice, the client will never say it; instead it will cease requests once it is satisfied. In the client, the main change lies in the transport and transport helper code. fetch_refs_via_pack() performs everything needed - protocol version and capability checks, and the negotiation itself. There are 2 code paths that do not go through fetch_refs_via_pack() that needed to be individually excluded: the bundle transport (excluded through requiring smart_options, which the bundle transport doesn't support) and transport helpers that do not support takeover. If or when we support independent negotiation for protocol v0, we will need to modify these 2 code paths to support it. But for now, report failure if independent negotiation is requested in these cases. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	6871d0cec6	fetch-pack: refactor command and capability write A subsequent commit will need this functionality independent of the rest of send_fetch_request(), so put this into its own function. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	57c3451b2e	fetch-pack: refactor add_haves() A subsequent commit will need part, but not all, of the functionality in add_haves(), so move some of its functionality to its sole caller send_fetch_request(). Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	8102570374	fetch-pack: refactor process_acks() A subsequent commit will need part, but not all, of the functionality in process_acks(), so move some of its functionality to its sole caller do_fetch_pack_v2(). As a side effect, the resulting code is also shorter. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	81ed96a9b2	fetch-pack: buffer object-format with other args In send_fetch_request(), "object-format" is written directly to the file descriptor, as opposed to the other arguments, which are buffered. Buffer "object-format" as well. "object-format" must be buffered; in particular, it must appear after "command=fetch" in the request. This divergence was introduced in `4b831208bb` ("fetch-pack: parse and advertise the object-format capability", 2020-05-27), perhaps as an oversight (the surrounding code at the point of this commit has already been using a request buffer.) Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Li Linchao	4fe788b1b0	builtin/clone.c: add --reject-shallow option In some scenarios, users may want more history than the repository offered for cloning, which happens to be a shallow repository, can give them. But because users don't know it is a shallow repository until they download it to local, we may want to refuse to clone this kind of repository, without creating any unnecessary files. The '--depth=x' option cannot be used as a solution; the source may be deep enough to give us 'x' commits when cloned, but the user may later need to deepen the history to arbitrary depth. Teach '--reject-shallow' option to "git clone" to abort as soon as we find out that we are cloning from a shallow repository. Signed-off-by: Li Linchao <lilinchao@oschina.cn> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Ævar Arnfjörð Bjarmason	3745e2693d	fetch-pack: use new fsck API to printing dangling submodules Refactor the check added in `5476e1efde` (fetch-pack: print and use dangling .gitmodules, 2021-02-22) to make use of us now passing the "msg_id" to the user defined "error_func". We can now compare against the FSCK_MSG_GITMODULES_MISSING instead of parsing the generated message. Let's also replace register_found_gitmodules() with directly manipulating the "gitmodules_found" member. A recent commit moved it into "fsck_options" so we could do this here. I'm sticking this callback in fsck.c. Perhaps in the future we'd like to accumulate such callbacks into another file (maybe fsck-cb.c, similar to parse-options-cb.c?), but while we've got just the one let's just put it into fsck.c. A better alternative in this case would be some library some more obvious library shared by fetch-pack.c ad builtin/index-pack.c, but there isn't such a thing. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Ævar Arnfjörð Bjarmason	c96e184cae	fetch-pack: use file-scope static struct for fsck_options Change code added in `5476e1efde` (fetch-pack: print and use dangling .gitmodules, 2021-02-22) so that we use a file-scoped "static struct fsck_options" instead of defining one in the "fsck_gitmodules_oids()" function. We use this pattern in all of builtin/{fsck,index-pack,mktag,unpack-objects}.c. It's odd to see fetch-pack be the odd one out. One might think that we're using other fsck_options structs in fetch-pack, or doing on fsck twice there, but we're not. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Ævar Arnfjörð Bjarmason	c15087d17b	fsck.c: move gitmodules_{found,done} into fsck_options Move the gitmodules_{found,done} static variables added in `159e7b080b` (fsck: detect gitmodules files, 2018-05-02) into the fsck_options struct. It makes sense to keep all the context in the same place. This requires changing the recently added register_found_gitmodules() function added in `5476e1efde` (fetch-pack: print and use dangling .gitmodules, 2021-02-22) to take fsck_options. That function will be removed in a subsequent commit, but as it'll require the new gitmodules_found attribute of "fsck_options" we need this intermediate step first. An earlier version of this patch removed the small amount of duplication we now have between FSCK_OPTIONS_{DEFAULT,STRICT} with a FSCK_OPTIONS_COMMON macro. I don't think such de-duplication is worth it for this amount of copy/pasting. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
René Scharfe	ca56dadb4b	use CALLOC_ARRAY Add and apply a semantic patch for converting code that open-codes CALLOC_ARRAY to use it instead. It shortens the code and infers the element size automatically. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	2aec3bc4b6	fetch-pack: do not mix --pack_header and packfile uri When fetching (as opposed to cloning) from a repository with packfile URIs enabled, an error like this may occur: fatal: pack has bad object at offset 12: unknown object type 5 fatal: finish_http_pack_request gave result -1 fatal: fetch-pack: expected keep then TAB at start of http-fetch output This bug was introduced in `b664e9ffa1` ("fetch-pack: with packfile URIs, use index-pack arg", 2021-02-22), when the index-pack args used when processing the inline packfile of a fetch response and when processing packfile URIs were unified. This bug happens because fetch, by default, partially reads (and consumes) the header of the inline packfile to determine if it should store the downloaded objects as a packfile or loose objects, and thus passes --pack_header=<...> to index-pack to inform it that some bytes are missing. However, when it subsequently fetches the additional packfiles linked by URIs, it reuses the same index-pack arguments, thus wrongly passing --index-pack-arg=--pack_header=<...> when no bytes are missing. This does not happen when cloning because "git clone" always passes do_keep, which instructs the fetch mechanism to always retain the packfile, eliminating the need to read the header. There are a few ways to fix this, including filtering out pack_header arguments when downloading the additional packfiles, but I decided to stick to always using index-pack throughout when packfile URIs are present - thus, Git no longer needs to read the bytes, and no longer needs --pack_header here. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	5476e1efde	fetch-pack: print and use dangling .gitmodules Teach index-pack to print dangling .gitmodules links after its "keep" or "pack" line instead of declaring an error, and teach fetch-pack to check such lines printed. This allows the tree side of the .gitmodules link to be in one packfile and the blob side to be in another without failing the fsck check, because it is now fetch-pack which checks such objects after all packfiles have been downloaded and indexed (and not index-pack on an individual packfile, as it is before this commit). Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	b664e9ffa1	fetch-pack: with packfile URIs, use index-pack arg Unify the index-pack arguments used when processing the inline pack and when downloading packfiles referenced by URIs. This is done by teaching get_pack() to also store the index-pack arguments whenever at least one packfile URI is given, and then when processing the packfile URI(s), using the stored arguments. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	27e35ba6c6	http-fetch: allow custom index-pack args This is the next step in teaching fetch-pack to pass its index-pack arguments when processing packfiles referenced by URIs. The "--keep" in fetch-pack.c will be replaced with a full message in a subsequent commit. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Christian Couder	33add2ad7d	fetch-pack: refactor writing promisor file Let's replace the 2 different pieces of code that write a promisor file in 'builtin/repack.c' and 'fetch-pack.c' with a new function called 'write_promisor_file()' in 'pack-write.c' and 'pack.h'. This might also help us in the future, if we want to put back the ref names and associated hashes that were in the promisor files we are repacking in 'builtin/repack.c' as suggested by a NEEDSWORK comment just above the code we are refactoring. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Christian Couder	9d7fa3be31	fetch-pack: rename helper to create_promisor_file() As we are going to refactor the code that actually writes the promisor file into a separate function in a following commit, let's rename the current write_promisor_file() function to create_promisor_file(). Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
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>	4 years ago
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>	4 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	6 years ago
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>	6 years ago
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>	6 years ago

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365 Commits (22597af97d67660fb3f0dba538a1f02b1ba94243)