git/upload-pack.c, branch v2.31.2

Merge branch 'ak/corrected-commit-date'

2021-02-18T01:21:40Z

The commit-graph learned to use corrected commit dates instead of the generation number to help topological revision traversal. * ak/corrected-commit-date: doc: add corrected commit date info commit-reach: use corrected commit dates in paint_down_to_common() commit-graph: use generation v2 only if entire chain does commit-graph: implement generation data chunk commit-graph: implement corrected commit date commit-graph: return 64-bit generation number commit-graph: add a slab to store topological levels t6600-test-reach: generalize *_three_modes commit-graph: consolidate fill_commit_graph_info revision: parse parent in indegree_walk_step() commit-graph: fix regression when computing Bloom filters

Merge branch 'jv/upload-pack-filter-spec-quotefix'

2021-02-12T22:21:04Z

Fix in passing custom args from "git clone" to "upload-pack" on the other side. * jv/upload-pack-filter-spec-quotefix: t5544: clarify 'hook works with partial clone' test upload-pack.c: fix filter spec quoting bug

upload-pack.c: fix filter spec quoting bug

2021-01-28T17:40:24Z

Fix a bug in upload-pack.c that occurs when you combine partial clone and uploadpack.packObjectsHook. You can reproduce it as follows: git clone -u 'git -c uploadpack.allowfilter '\ '-c uploadpack.packobjectshook=env '\ 'upload-pack' --filter=blob:none --no-local \ src.git dst.git Be careful with the line endings because this has a long quoted string as the -u argument. The error I get when I run this is: Cloning into '/tmp/broken'... remote: fatal: invalid filter-spec ''blob:none'' error: git upload-pack: git-pack-objects died with error. fatal: git upload-pack: aborting due to possible repository corruption on the remote side. remote: aborting due to possible repository corruption on the remote side. fatal: early EOF fatal: index-pack failed The problem is caused by unneeded quoting. This bug was already present in 10ac85c785 (upload-pack: add object filtering for partial clone, 2017-12-08) when the server side filter support was introduced. In fact, in 10ac85c785 this was broken regardless of uploadpack.packObjectsHook. Then in 0b6069fe0a (fetch-pack: test support excluding large blobs, 2017-12-08) the quoting was removed but only behind a conditional that depends on whether uploadpack.packObjectsHook is set. Because uploadpack.packObjectsHook is apparently rarely used, nobody noticed the problematic quoting could still happen. Remove the conditional quoting and add a test for partial clone in t5544-pack-objects-hook. Signed-off-by: Jacob Vosmaer Signed-off-by: Junio C Hamano

refs: switch peel_ref() to peel_iterated_oid()

2021-01-21T23:51:31Z

The peel_ref() interface is confusing and error-prone: - it's typically used by ref iteration callbacks that have both a refname and oid. But since they pass only the refname, we may load the ref value from the filesystem again. This is inefficient, but also means we are open to a race if somebody simultaneously updates the ref. E.g., this: int some_ref_cb(const char *refname, const struct object_id *oid, ...) { if (!peel_ref(refname, &peeled)) printf("%s peels to %s", oid_to_hex(oid), oid_to_hex(&peeled); } could print nonsense. It is correct to say "refname peels to..." (you may see the "before" value or the "after" value, either of which is consistent), but mentioning both oids may be mixing before/after values. Worse, whether this is possible depends on whether the optimization to read from the current iterator value kicks in. So it is actually not possible with: for_each_ref(some_ref_cb); but it _is_ possible with: head_ref(some_ref_cb); which does not use the iterator mechanism (though in practice, HEAD should never peel to anything, so this may not be triggerable). - it must take a fully-qualified refname for the read_ref_full() code path to work. Yet we routinely pass it partial refnames from callbacks to for_each_tag_ref(), etc. This happens to work when iterating because there we do not call read_ref_full() at all, and only use the passed refname to check if it is the same as the iterator. But the requirements for the function parameters are quite unclear. Instead of taking a refname, let's instead take an oid. That fixes both problems. It's a little funny for a "ref" function not to involve refs at all. The key thing is that it's optimizing under the hood based on having access to the ref iterator. So let's change the name to make it clear why you'd want this function versus just peel_object(). There are two other directions I considered but rejected: - we could pass the peel information into the each_ref_fn callback. However, we don't know if the caller actually wants it or not. For packed-refs, providing it is essentially free. But for loose refs, we actually have to peel the object, which would be wasteful in most cases. We could likewise pass in a flag to the callback indicating whether the peeled information is known, but that complicates those callbacks, as they then have to decide whether to manually peel themselves. Plus it requires changing the interface of every callback, whether they care about peeling or not, and there are many of them. - we could make a function to return the peeled value of the current iterated ref (computing it if necessary), and BUG() otherwise. I.e.: int peel_current_iterated_ref(struct object_id *out); Each of the current callers is an each_ref_fn callback, so they'd mostly be happy. But: - we use those callbacks with functions like head_ref(), which do not use the iteration code. So we'd need to handle the fallback case there, anyway. - it's possible that a caller would want to call into generic code that sometimes is used during iteration and sometimes not. This encapsulates the logic to do the fast thing when possible, and fallback when necessary. The implementation is mostly obvious, but I want to call out a few things in the patch: - the test-tool coverage for peel_ref() is now meaningless, as it all collapses to a single peel_object() call (arguably they were pretty uninteresting before; the tricky part of that function is the fast-path we see during iteration, but these calls didn't trigger that). I've just dropped it entirely, though note that some other tests relied on the tags we created; I've moved that creation to the tests where it matters. - we no longer need to take a ref_store parameter, since we'd never look up a ref now. We do still rely on a global "current iterator" variable which _could_ be kept per-ref-store. But in practice this is only useful if there are multiple recursive iterations, at which point the more appropriate solution is probably a stack of iterators. No caller used the actual ref-store parameter anyway (they all call the wrapper that passes the_repository). - the original only kicked in the optimization when the "refname" pointer matched (i.e., not string comparison). We do likewise with the "oid" parameter here, but fall back to doing an actual oideq() call. This in theory lets us kick in the optimization more often, though in practice no current caller cares. It should never be wrong, though (peeling is a property of an object, so two refs pointing to the same object would peel identically). - the original took care not to touch the peeled out-parameter unless we found something to put in it. But no caller cares about this, and anyway, it is enforced by peel_object() itself (and even in the optimized iterator case, that's where we eventually end up). We can shorten the code and avoid an extra copy by just passing the out-parameter through the stack. Signed-off-by: Jeff King Reviewed-by: Taylor Blau Signed-off-by: Junio C Hamano

commit-graph: return 64-bit generation number

2021-01-19T00:21:18Z

In a preparatory step for introducing corrected commit dates, let's return timestamp_t values from commit_graph_generation(), use timestamp_t for local variables and define GENERATION_NUMBER_INFINITY as (2 ^ 63 - 1) instead. We rename GENERATION_NUMBER_MAX to GENERATION_NUMBER_V1_MAX to represent the largest topological level we can store in the commit data chunk. With corrected commit dates implemented, we will have two such *_MAX variables to denote the largest offset and largest topological level that can be stored. Signed-off-by: Abhishek Kumar Reviewed-by: Taylor Blau Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano

Merge branch 'tb/partial-clone-filters-fix'

2020-12-17T23:06:40Z

Fix potential server side resource deallocation issues when responding to a partial clone request. * tb/partial-clone-filters-fix: upload-pack.c: don't free allowed_filters util pointers builtin/clone.c: don't ignore transport_fetch_refs() errors

Merge branch 'jk/multi-line-indent-style-fix'

2020-12-14T18:21:38Z

Style fix. * jk/multi-line-indent-style-fix: style: indent multiline "if" conditions to align

Merge branch 'jk/check-config-parsing-error-in-upload-pack'

2020-12-14T18:21:37Z

Tighten error checking in the codepath that responds to "git fetch". * jk/check-config-parsing-error-in-upload-pack: upload-pack: propagate return value from object filter config callback

Merge branch 'js/trace2-session-id'

2020-12-08T23:11:20Z

The transport layer was taught to optionally exchange the session ID assigned by the trace2 subsystem during fetch/push transactions. * js/trace2-session-id: receive-pack: log received client session ID send-pack: advertise session ID in capabilities upload-pack, serve: log received client session ID fetch-pack: advertise session ID in capabilities transport: log received server session ID serve: advertise session ID in v2 capabilities receive-pack: advertise session ID in v0 capabilities upload-pack: advertise session ID in v0 capabilities trace2: add a public function for getting the SID docs: new transfer.advertiseSID option docs: new capability to advertise session IDs

upload-pack.c: don't free allowed_filters util pointers

2020-12-03T20:42:33Z

To keep track of which object filters are allowed or not, 'git upload-pack' stores the name of each filter in a string_list, and sets it ->util pointer to be either 0 or 1, indicating whether it is banned or allowed. Later on, we attempt to clear that list, but we incorrectly ask for the util pointers to be free()'d, too. This behavior (introduced back in 6dd3456a8c (upload-pack.c: allow banning certain object filter(s), 2020-08-03)) leads to an invalid free, and causes us to crash. In order to trigger this, one needs to fetch from a server that (a) has at least one object filter allowed, and (b) issue a fetch that contains a subset of the allowed filters (i.e., we cannot ask for a banned filter, since this causes us to die() before we hit the bogus string_list_clear()). In that case, whatever banned filters exist will cause a noop free() (since those ->util pointers are set to 0), but the first allowed filter we try to free will crash us. We never noticed this in the tests because we didn't have an example of setting 'uploadPackFilter' configuration variables and then following up with a valid fetch. The first new 'git clone' prevents further regression here. For good measure on top, add a test which checks the same behavior at a tree depth greater than 0. Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano