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>
"git push --atomic" used to show failures for refs that weren't
even pushed, which has been corrected.
* jx/atomic-push:
transport-helper: new method reject_atomic_push()
transport-helper: mark failure for atomic push
send-pack: mark failure of atomic push properly
t5543: never report what we do not push
send-pack: fix inconsistent porcelain output
Add new method in transport-helper to reject all references if any
reference is failed for atomic push.
This method is reused in "send-pack.c" and "transport-helper.c", one for
SSH, git and file protocols, and the other for HTTP protocol.
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When pushing with SSH or other smart protocol, references are validated
by function `check_to_send_update()` before they are sent in commands
to `send_pack()` of "receve-pack". For atomic push, if a reference is
rejected after the validation, only references pushed by user should be
marked as failure, instead of report failure on all remote references.
Commit v2.22.0-1-g3bca1e7f9f (transport-helper: enforce atomic in
push_refs_with_push, 2019-07-11) wanted to fix report issue of HTTP
protocol, but marked all remote references failure for atomic push.
In order to fix the issue of status report for SSH or other built-in
smart protocol, revert part of that commit and add additional status
for function `atomic_push_failure()`. The additional status for it
except the "REF_STATUS_EXPECTING_REPORT" status are:
- REF_STATUS_NONE : Not marked as "REF_STATUS_EXPECTING_REPORT" yet.
- REF_STATUS_OK : Assume OK for dryrun or status_report is disabled.
This fix won't resolve the issue of status report in transport-helper
for HTTP or other protocols, and breaks test case in t5541. Will fix
it in additional commit.
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The porcelain output of a failed `git-push` command is inconsistent for
different protocols. For example, the following `git-push` command
may fail due to the failure of the `pre-receive` hook.
git push --porcelain origin HEAD:refs/heads/master
For SSH protocol, the porcelain output does not end with a "Done"
message:
To <URL/of/upstream.git>
! HEAD:refs/heads/master [remote rejected] (pre-receive hook declined)
While for HTTP protocol, the porcelain output does end with a "Done"
message:
To <URL/of/upstream.git>
! HEAD:refs/heads/master [remote rejected] (pre-receive hook declined)
Done
The following code at the end of function `send_pack()` indicates that
`send_pack()` should not return an error if some references are rejected
in porcelain mode.
int send_pack(...)
... ...
if (args->porcelain)
return 0;
for (ref = remote_refs; ref; ref = ref->next) {
switch (ref->status) {
case REF_STATUS_NONE:
case REF_STATUS_UPTODATE:
case REF_STATUS_OK:
break;
default:
return -1;
}
}
return 0;
}
So if atomic push failed, must check the porcelain mode before return
an error. And `receive_status()` should not return an error for a
failed updated reference, because `send_pack()` will check them instead.
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Performance tweak on "git push" into a repository with many refs
that point at objects we have never heard of.
* jk/send-pack-check-negative-with-quick:
send-pack: use OBJECT_INFO_QUICK to check negative objects
Error handling after "git push" finishes sending the packdata and
waits for the response to the remote side has been improved.
* jk/send-pack-remote-failure:
send-pack: check remote ref status on pack-objects failure
When pushing, we feed pack-objects a list of both positive and negative
objects. The positive objects are what we want to send, and the negative
objects are what the other side told us they have, which we can use to
limit the size of the push.
Before passing along a negative object, send_pack() will make sure we
actually have it (since we only know about it because the remote
mentioned it, not because it's one of our refs). So it's expected that
some of these objects will be missing on the local side. But looking for
a missing object is more expensive than one that we have: it triggers
reprepare_packed_git() to handle a racy repack, plus it has to explore
every alternate's loose object tree (which can be slow if you have a lot
of them, or have a high-latency filesystem).
This isn't usually a big problem, since repositories you're pushing to
don't generally have a large number of refs that are unrelated to what
the client has. But there's no reason such a setup is wrong, and it
currently performs poorly.
We can fix this by using OBJECT_INFO_QUICK, which tells the lookup
code that we expect objects to be missing. Notably, it will not re-scan
the packs, and it will use the loose cache from 61c7711cfe (sha1-file:
use loose object cache for quick existence check, 2018-11-12).
The downside is that in the rare case that we race with a local repack,
we might fail to feed some objects to pack-objects, making the resulting
push larger. But we'd never produce an invalid or incorrect push, just a
less optimal one. That seems like a reasonable tradeoff, and we already
do similar things on the fetch side (e.g., when marking COMPLETE
commits).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we're pushing a pack and our local pack-objects fails, we enter an
error code path that does a few things:
1. Set the status of every ref to REF_STATUS_NONE
2. Call receive_unpack_status() to try to get an error report from
the other side
3. Return an error to the caller
If pack-objects failed because the connection to the server dropped,
there's not much more we can do than report the hangup. And indeed, step
2 will try to read a packet from the other side, which will die() in the
packet-reading code with "the remote end hung up unexpectedly".
But if the connection _didn't_ die, then the most common issue is that
the remote index-pack or unpack-objects complained about our pack (we
could also have a local pack-objects error, but this ends up being the
same; we'd send an incomplete pack and the remote side would complain).
In that case we do report the error from the other side (because of step
2), but we fail to say anything further about the refs. The issue is
two-fold:
- in step 1, the "NONE" status is not "we saw an error, so we have no
status". It generally means "this ref did not match our refspecs, so
we didn't try to push it". So when we print out the push status
table, we won't mention any refs at all!
But even if we had a status enum for "pack-objects error", we
wouldn't want to blindly set it for every ref. For example, in a
non-atomic push we might have rejected some refs already on the
client side (e.g., REF_STATUS_REJECT_NODELETE) and we'd want to
report that.
- in step 2, we read just the unpack status. But receive-pack will
also tell us about each ref (usually that it rejected them because
of the unpacker error).
So a much better strategy is to leave the ref status fields as they are
(usually EXPECTING_REPORT) and then actually receive (and print) the
full per-ref status.
This case is actually covered in the test suite, as t5504.8, which
writes a pack that will be rejected by the remote unpack-objects. But
it's racy. Because our pack is small, most of the time pack-objects
manages to write the whole thing before the remote rejects it, and so it
returns success and we print out the errors from the remote. But very
occasionally (or when run under --stress) it goes slow enough to see a
failure in writing, and git-push reports nothing for the refs.
With this patch, the test should behave consistently.
There shouldn't be any downside to this approach. If we really did see
the connection drop, we'd already die in receive_unpack_status(), and
we'll continue to do so. If the connection drops _after_ we get the
unpack status but before we see any ref status, we'll still print the
remote unpacker error, but will now say "remote end hung up" instead of
returning the error up the call-stack. But as discussed, we weren't
showing anything more useful than that with the current code. And
anyway, that case is quite unlikely (the connection dropping at that
point would have to be unrelated to the pack-objects error, because of
the ordering of events).
In the future we might want to handle packet-read errors ourself instead
of dying, which would print a full ref status table even for hangups.
But in the meantime, this patch should be a strict improvement.
Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When building the packfile to be sent, send_pack() is given a list of
remote refs to be used as exclusions. For each ref, it first checks if
the ref exists locally, and if it does, passes it with a "^" prefix to
pack-objects. However, in a partial clone, the check may trigger a lazy
fetch.
The additional commit ancestry information obtained during such fetches
may show that certain objects that would have been sent are already
known to the server, resulting in a smaller pack being sent. But this is
at the cost of fetching from many possibly unrelated refs, and the lazy
fetches do not help at all in the typical case where the client is
up-to-date with the upstream of the branch being pushed.
Ensure that these lazy fetches do not occur.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The only remaining callers of has_sha1_file() actually have an object_id
already. They can use the "object" variant, rather than dereferencing
the hash themselves.
The code changes here were completely generated by the included
coccinelle patch.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the Git pack protocol definition, an error packet may appear only in
a certain context. However, servers can face a runtime error (e.g. I/O
error) at an arbitrary timing. This patch changes the protocol to allow
an error packet to be sent instead of any packet.
Without this protocol spec change, when a server cannot process a
request, there's no way to tell that to a client. Since the server
cannot produce a valid response, it would be forced to cut a connection
without telling why. With this protocol spec change, the server can be
more gentle in this situation. An old client may see these error packets
as an unexpected packet, but this is not worse than having an unexpected
EOF.
Following this protocol spec change, the error packet handling code is
moved to pkt-line.c. Implementation wise, this implementation uses
pkt-line to communicate with a subprocess. Since this is not a part of
Git protocol, it's possible that a packet that is not supposed to be an
error packet is mistakenly parsed as an error packet. This error packet
handling is enabled only for the Git pack protocol parsing code
considering this.
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By using and sharing a packet_reader while handling a Git pack protocol
request, the same reader option is used throughout the code. This makes
it easy to set a reader option to the request parsing code.
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On systems that do not support multithread, start_async() is
implemented with fork(). This implementation details unfortunately
leak out at least in send-pack.c [1].
To keep the code base clean of NO_PTHREADS, move the this #ifdef back
to run-command.c. The new wrapper function async_with_fork() at least
helps suggest that this special "close()" is related to async in fork
mode.
[1] 09c9957cf7 (send-pack: avoid deadlock when pack-object dies early
- 2011-04-25)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow callers of is_repository_shallow
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This should make these functions easier to find and cache.h less
overwhelming to read.
In particular, this moves:
- read_object_file
- oid_object_info
- write_object_file
As a result, most of the codebase needs to #include object-store.h.
In this patch the #include is only added to files that would fail to
compile otherwise. It would be better to #include wherever
identifiers from the header are used. That can happen later
when we have better tooling for it.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the remaining function, feed_object, to use struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The packet_read_line() function will die if it sees any
protocol or socket errors. But it will return NULL for a
flush packet; some callers which are not expecting this may
dereference NULL if they get an unexpected flush. This would
involve the other side breaking protocol, but we should
flag the error rather than segfault.
Signed-off-by: Jon Simons <jon@jonsimons.org>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Avoid a magic number of NULL placeholder values and a magic index by
constructing the command line for pack-objects using the embedded
argv_array of the child_process. The resulting code is shorter and
easier to extend.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Gcc 7 adds -Wimplicit-fallthrough, which can warn when a
switch case falls through to the next case. The general idea
is that the compiler can't tell if this was intentional or
not, so you should annotate any intentional fall-throughs as
such, leaving it to complain about any unannotated ones.
There's a GNU __attribute__ which can be used for
annotation, but of course we'd have to #ifdef it away on
non-gcc compilers. Gcc will also recognize
specially-formatted comments, which matches our current
practice. Let's extend that practice to all of the
unannotated sites (which I did look over and verify that
they were behaving as intended).
Ideally in each case we'd actually give some reasons in the
comment about why we're falling through, or what we're
falling through to. And gcc does support that with
-Wimplicit-fallthrough=2, which relaxes the comment pattern
matching to anything that contains "fallthrough" (or a
variety of spelling variants). However, this isn't the
default for -Wimplicit-fallthrough, nor for -Wextra. In the
name of simplicity, it's probably better for us to support
the default level, which requires "fallthrough" to be the
only thing in the comment (modulo some window dressing like
"else" and some punctuation; see the gcc manual for the
complete set of patterns).
This patch suppresses all warnings due to
-Wimplicit-fallthrough. We might eventually want to add that
to the DEVELOPER Makefile knob, but we should probably wait
until gcc 7 is more widely adopted (since earlier versions
will complain about the unknown warning type).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stop including config.h by default in cache.h. Instead only include
config.h in those files which require use of the config system.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Conversion from unsigned char [40] to struct object_id continues.
* bc/object-id:
Documentation: update and rename api-sha1-array.txt
Rename sha1_array to oid_array
Convert sha1_array_for_each_unique and for_each_abbrev to object_id
Convert sha1_array_lookup to take struct object_id
Convert remaining callers of sha1_array_lookup to object_id
Make sha1_array_append take a struct object_id *
sha1-array: convert internal storage for struct sha1_array to object_id
builtin/pull: convert to struct object_id
submodule: convert check_for_new_submodule_commits to object_id
sha1_name: convert disambiguate_hint_fn to take object_id
sha1_name: convert struct disambiguate_state to object_id
test-sha1-array: convert most code to struct object_id
parse-options-cb: convert sha1_array_append caller to struct object_id
fsck: convert init_skiplist to struct object_id
builtin/receive-pack: convert portions to struct object_id
builtin/pull: convert portions to struct object_id
builtin/diff: convert to struct object_id
Convert GIT_SHA1_RAWSZ used for allocation to GIT_MAX_RAWSZ
Convert GIT_SHA1_HEXSZ used for allocation to GIT_MAX_HEXSZ
Define new hash-size constants for allocating memory
Since this structure handles an array of object IDs, rename it to struct
oid_array. Also rename the accessor functions and the initialization
constant.
This commit was produced mechanically by providing non-Documentation
files to the following Perl one-liners:
perl -pi -E 's/struct sha1_array/struct oid_array/g'
perl -pi -E 's/\bsha1_array_/oid_array_/g'
perl -pi -E 's/SHA1_ARRAY_INIT/OID_ARRAY_INIT/g'
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the internal storage for struct sha1_array use an array of struct
object_id internally. Update the users of this struct which inspect its
internals.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Recently we started passing the "--push-options" through the
external remote helper interface; now the "smart HTTP" remote
helper understands what to do with the passed information.
* sb/push-options-via-transport:
remote-curl: allow push options
send-pack: send push options correctly in stateless-rpc case
"git send-pack --stateless-rpc" puts each request in a sequence of pkt-lines
followed by a flush-pkt. The push option code forgot about this and sends push
options and their terminating delimiter as ordinary pkt-lines that get their
length header stripped off by remote-curl before being sent to the server.
The result is multiple malformed requests, which the server rejects.
Fortunately send-pack --stateless-rpc already is aware of this "pkt-line within
pkt-line" framing for the update commands that precede push options. Handle
push options the same way.
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If our pack-objects sub-process dies of a signal, then it
likely didn't have a chance to write anything useful to
stderr. The user may be left scratching their head why the
push failed. Let's detect this situation and write something
to stderr.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the local pack-objects of a push fails, we'll tell the
user about it. But one likely cause is that the remote
index-pack stopped reading for some reason (because it
didn't like our input, or encountered another error). In
that case we'd expect the remote to report more details to
us via the "unpack ..." status line. However, the current
code just hangs up completely, and the user never sees it.
Instead, let's call receive_unpack_status(), which will
complain on stderr with whatever reason the remote told us.
Note that if our pack-objects fails because the connection
was severed or the remote just crashed entirely, then our
packet_read_line() call may fail with "the remote end hung
up unexpectedly". That's OK. It's a more accurate
description than what we get now (which is just "some refs
failed to push").
This should be safe from any deadlocks. At the point we make
this call we'll have closed the writing end of the
connection to the server (either by handing it off to
a pack-objects which exited, explicitly in the stateless_rpc
case, or by doing a half-duplex shutdown for a socket). So
there should be no chance that the other side is waiting
for the rest of our pack-objects input.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the remote tells us that the "unpack" step failed, we
show an error message. However, unless you are familiar with
the internals of send-pack and receive-pack, it was not
clear that this represented an error on the remote side.
Let's re-word to make that more obvious.
Likewise, when we got an unexpected packet from the other
end, we complained with a vague message but did not actually
show the packet. Let's fix that.
And finally, neither message was marked for translation. The
message from the remote probably won't be translated, but
there's no reason we can't do better for the local half.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This avoids repeating ourselves, and the use of magic
numbers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After sending the pack, we call receive_status() which gets
both the "unpack" line and the ref status. Let's break these
into two functions so we can call the first part
independently.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
d64ea0f83b ("git-compat-util: add xstrdup_or_null helper",
2015-01-12) added a handy wrapper that allows us to get a duplicate
of a string or NULL if the original is NULL, but a handful of
codepath predate its introduction or just weren't aware of it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace uses of strbuf_addf() for adding strings with more lightweight
strbuf_addstr() calls.
In http-push.c it becomes easier to see what's going on without having
to verfiy that the definition of PROPFIND_ALL_REQUEST doesn't contain
any format specifiers.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This implements everything that is required on the client side to make use
of push options from the porcelain push command.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We start a pack-objects process and then write all of the
positive and negative sha1s to it over a pipe. We do so by
formatting each item into a fixed-size buffer and then
writing each individually. This has two drawbacks:
1. There's some manual computation of the buffer size,
which is not immediately obvious is correct (though it
is).
2. We write() once per sha1, which means a lot more system
calls than are necessary.
We can solve both by wrapping the pipe descriptor in a stdio
handle; this is the same technique used by upload-pack when
serving fetches.
Note that we can also simplify and improve the error
handling here. The original detected a single write error
and broke out of the loop (presumably to avoid writing the
error message over and over), but never actually acted on
seeing an error; we just fed truncated input and took
whatever pack-objects returned.
In practice, this probably didn't matter, as the likely
errors would be caused by pack-objects dying (and we'd
probably just die with SIGPIPE anyway). But we can easily
make this simpler and more robust; the stdio handle keeps an
error flag, which we can check at the end.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we get an error from pack-objects, we may exit
send_pack() early, before reading the server's status
response. In such a case, we may racily see SIGPIPE from our
async demuxer (which is trying to write that status back to
us), and we'd prefer to continue pushing the error up the
call stack, rather than taking down the whole process with
signal death.
This is safe to do because our demuxer just calls
recv_sideband, whose data writes are all done with
write_or_die(), which will notice SIGPIPE.
We do also write sideband 2 to stderr, and we would no
longer die on SIGPIPE there (if it were piped in the first
place, and if the piped program went away). But that's
probably a good thing, as it likewise should not abort the
push process at all (neither immediately by signal, nor
eventually by reporting failure back to the main thread).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This fixes a deadlock on the client side when pushing a
large number of refs from a corrupted repo. There's a
reproduction script below, but let's start with a
human-readable explanation.
The client side of a push goes something like this:
1. Start an async process to demux sideband coming from
the server.
2. Run pack-objects to send the actual pack, and wait for
its status via finish_command().
3. If pack-objects failed, abort immediately.
4. If pack-objects succeeded, read the per-ref status from
the server, which is actually coming over a pipe from
the demux process started in step 1.
We run finish_async() to wait for and clean up the demux
process in two places. In step 3, if we see an error, we
want it to end early. And after step 4, it should be done
writing any data and we are just cleaning it up.
Let's focus on the error case first. We hand the output
descriptor to the server over to pack-objects. So by the
time it has returned an error to us, it has closed the
descriptor and the server has gotten EOF. The server will
mark all refs as failed with "unpacker error" and send us
back the status for each (followed by EOF).
This status goes to the demuxer thread, which relays it over
a pipe to the main thread. But the main thread never even
tries reading the status. It's trying to bail because of the
pack-objects error, and is waiting for the demuxer thread to
finish. If there are a small number of refs, that's OK; the
demuxer thread writes into the pipe buffer, sees EOF from
the server, and quits. But if there are a large number of
refs, it may block on write() back to the main thread,
leading to a deadlock (the main thread is waiting for the
demuxer to finish, the demuxer is waiting for the main
thread to read).
We can break this deadlock by closing the pipe between the
demuxer and the main thread before calling finish_async().
Then the demuxer gets a write() error and exits.
The non-error case usually just works, because we will have
read all of the data from the other side. We do close
demux.out already, but we only do so _after_ calling
finish_async(). This is OK because there shouldn't be any
more data coming from the server. But technically we've only
read to a flush packet, and a broken or malicious server
could be sending more cruft. In such a case, we would hit
the same deadlock. Closing the pipe first doesn't affect the
normal case, and means that for a cruft-sending server,
we'll notice a write() error rather than deadlocking.
Note that when write() sees this error, we'll actually
deliver SIGPIPE to the thread, which will take down the
whole process (unless we're compiled with NO_PTHREADS). This
isn't ideal, but it's an improvement over the status quo,
which is deadlocking. And SIGPIPE handling in async threads
is a bigger problem that we can deal with separately.
A simple reproduction for the error case is below. It's
technically racy (we could exit the main process and take
down the async thread with us before it even reads the
status), though in practice it seems to fail pretty
consistently.
git init repo &&
cd repo &&
# make some commits; we need two so we can simulate corruption
# in the history later.
git commit --allow-empty -m one &&
one=$(git rev-parse HEAD) &&
git commit --allow-empty -m two &&
two=$(git rev-parse HEAD) &&
# now make a ton of refs; our goal here is to overflow the pipe buffer
# when reporting the ref status, which will cause the demuxer to block
# on write()
for i in $(seq 20000); do
echo "create refs/heads/this-is-a-really-long-branch-name-$i $two"
done |
git update-ref --stdin &&
# now make a corruption in the history such that pack-objects will fail
rm -vf .git/objects/$(echo $one | sed 's}..}&/}') &&
# and then push the result
git init --bare dst.git &&
git push --mirror dst.git
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use struct object_id in three fields in struct ref and convert all the
necessary places that use it.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
The client side codepaths in "git push" have been cleaned up
and the user can request to perform an optional "signed push",
i.e. sign only when the other end accepts signed push.
* db/push-sign-if-asked:
push: add a config option push.gpgSign for default signed pushes
push: support signing pushes iff the server supports it
builtin/send-pack.c: use parse_options API
config.c: rename git_config_maybe_bool_text and export it as git_parse_maybe_bool
transport: remove git_transport_options.push_cert
gitremote-helpers.txt: document pushcert option
Documentation/git-send-pack.txt: document --signed
Documentation/git-send-pack.txt: wrap long synopsis line
Documentation/git-push.txt: document when --signed may fail
Add a new flag --sign=true (or --sign=false), which means the same
thing as the original --signed (or --no-signed). Give it a third
value --sign=if-asked to tell push and send-pack to send a push
certificate if and only if the server advertised a push cert nonce.
If not, warn the user that their push may not be as secure as they
thought.
Signed-off-by: Dave Borowitz <dborowitz@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Identify parts of the code that knows that we use SHA-1 hash to
name our objects too much, and use (1) symbolic constants instead
of hardcoded 20 as byte count and/or (2) use struct object_id
instead of unsigned char [20] for object names.
* bc/object-id:
apply: convert threeway_stage to object_id
patch-id: convert to use struct object_id
commit: convert parts to struct object_id
diff: convert struct combine_diff_path to object_id
bulk-checkin.c: convert to use struct object_id
zip: use GIT_SHA1_HEXSZ for trailers
archive.c: convert to use struct object_id
bisect.c: convert leaf functions to use struct object_id
define utility functions for object IDs
define a structure for object IDs
The "git push --signed" protocol extension did not limit what the
"nonce" that is a server-chosen string can contain or how long it
can be, which was unnecessarily lax. Limit both the length and the
alphabet to a reasonably small space that can still have enough
entropy.
* jc/push-cert:
push --signed: tighten what the receiving end can ask to sign
Instead of blindly trusting the receiving side to give us a sensible
nonce to sign, limit the length (max 256 bytes) and the alphabet
(alnum and a few selected punctuations, enough to encode in base64)
that can be used in nonce.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
