kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
Neeraj Singh	ecd81dfc79	tmp-objdir: disable ref updates when replacing the primary odb When creating a subprocess with a temporary ODB, we set the GIT_QUARANTINE_ENVIRONMENT env var to tell child Git processes not to update refs, since the tmp-objdir may go away. Introduce a similar mechanism for in-process temporary ODBs when we call tmp_objdir_replace_primary_odb. Now both mechanisms set the disable_ref_updates flag on the odb, which is queried by the ref_transaction_prepare function. Peff's test case [1] was invoking ref updates via the cachetextconv setting. That particular code silently does nothing when a ref update is forbidden. See the call to notes_cache_put in fill_textconv where errors are ignored. [1] https://lore.kernel.org/git/YVOn3hDsb5pnxR53@coredump.intra.peff.net/ Reported-by: Jeff King <peff@peff.net> Signed-off-by: Neeraj Singh <neerajsi@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Neeraj Singh	b3cecf49ea	tmp-objdir: new API for creating temporary writable databases The tmp_objdir API provides the ability to create temporary object directories, but was designed with the goal of having subprocesses access these object stores, followed by the main process migrating objects from it to the main object store or just deleting it. The subprocesses would view it as their primary datastore and write to it. Here we add the tmp_objdir_replace_primary_odb function that replaces the current process's writable "main" object directory with the specified one. The previous main object directory is restored in either tmp_objdir_migrate or tmp_objdir_destroy. For the --remerge-diff usecase, add a new `will_destroy` flag in `struct object_database` to mark ephemeral object databases that do not require fsync durability. Add 'git prune' support for removing temporary object databases, and make sure that they have a name starting with tmp_ and containing an operation-specific name. Based-on-patch-by: Elijah Newren <newren@gmail.com> Signed-off-by: Neeraj Singh <neerajsi@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Philip Oakley	26de1fc0c9	object-file.c: LLP64 compatibility, upcast unity for left shift Visual Studio reports C4334 "was 64-bit shift intended" warning because of size miss-match. Promote unity to the matching type to fit with the assignment. Signed-off-by: Philip Oakley <philipoakley@iee.email> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	c7c4bdeccf	run-command API: remove "env" member, always use "env_array" Remove the "env" member from "struct child_process" in favor of always using the "env_array". As with the preceding removal of "argv" in favor of "args" this gets rid of current and future oddities around memory management at the API boundary (see the amended API docs). For some of the conversions we can replace patterns like: child.env = env->v; With: strvec_pushv(&child.env_array, env->v); But for others we need to guard the strvec_pushv() with a NULL check, since we're not passing in the "v" member of a "struct strvec", e.g. in the case of tmp_objdir_env()'s return value. Ideally we'd rename the "env_array" member to simply "env" as a follow-up, since it and "args" are now inconsistent in not having an "_array" suffix, and seemingly without any good reason, unless we look at the history of how they came to be. But as we've currently got 122 in-tree hits for a "git grep env_array" let's leave that for now (and possibly forever). Doing that rename would be too disruptive. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	16235e3b14	object-file: free(*contents) only in read_loose_object() caller In the preceding commit a free() of uninitialized memory regression in `96e41f58fe` (fsck: report invalid object type-path combinations, 2021-10-01) was fixed, but we'd still have an issue with leaking memory from fsck_loose(). Let's fix that issue too. That issue was introduced in my `31deb28f5e` (fsck: don't hard die on invalid object types, 2021-10-01). It can be reproduced under SANITIZE=leak with the test I added in `093fffdfbe` (fsck tests: add test for fsck-ing an unknown type, 2021-10-01): ./t1450-fsck.sh --run=84 -vixd In some sense it's not a problem, we lost the same amount of memory in terms of things malloc'd and not free'd. It just moved from the "still reachable" to "definitely lost" column in valgrind(1) nomenclature[1], since we'd have die()'d before. But now that we don't hard die() anymore in the library let's properly free() it. Doing so makes this code much easier to follow, since we'll now have one function owning the freeing of the "contents" variable, not two. For context on that memory management pattern the read_loose_object() function was added in `f6371f9210` (sha1_file: add read_loose_object() function, 2017-01-13) and subsequently used in `c68b489e56` (fsck: parse loose object paths directly, 2017-01-13). The pattern of it being the task of both sides to free() the memory has been there in this form since its inception. 1. https://valgrind.org/docs/manual/mc-manual.html#mc-manual.leaks Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	168a937bbc	object-file: fix SEGV on free() regression in v2.34.0-rc2 Fix a regression introduced in my `96e41f58fe` (fsck: report invalid object type-path combinations, 2021-10-01). When fsck-ing blobs larger than core.bigFileThreshold, we'd free() a pointer to uninitialized memory. This issue would have been caught by SANITIZE=address, but since it involves core.bigFileThreshold, none of the existing tests in our test suite covered it. Running them with the "big_file_threshold" in "environment.c" changed to say "6" would have shown this failure, but let's add a dedicated test for this scenario based on Han Xin's report[1]. The bug was introduced between v9 and v10[2] of the fsck series merged in `061a21d36d` (Merge branch 'ab/fsck-unexpected-type', 2021-10-25). 1. https://lore.kernel.org/git/20211111030302.75694-1-hanxin.hx@alibaba-inc.com/ 2. https://lore.kernel.org/git/cover-v10-00.17-00000000000-20211001T091051Z-avarab@gmail.com/ Reported-by: Han Xin <chiyutianyi@gmail.com> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Matt Cooper	d6a09e795d	odb: guard against data loss checking out a huge file This introduces an additional guard for platforms where `unsigned long` and `size_t` are not of the same size. If the size of an object in the database would overflow `unsigned long`, instead we now exit with an error. A complete fix will have to update _many_ other functions throughout the codebase to use `size_t` instead of `unsigned long`. It will have to be implemented at some stage. This commit puts in a stop-gap for the time being. Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Matt Cooper <vtbassmatt@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	4ef91a2d79	commit: fix duplication regression in permission error output Fix a regression in the error output emitted when .git/objects can't be written to. Before `9c4d6c0297` (cache-tree: Write updated cache-tree after commit, 2014-07-13) we'd emit only one "insufficient permission" error, now we'll do so again. The cause is rather straightforward, we've got WRITE_TREE_SILENT for the use-case of wanting to prepare an index silently, quieting any permission etc. error output. Then when we attempt to update to that (possibly broken) index we'll run into the same errors again. But with `9c4d6c0297` the gap between the cache-tree API and the object store wasn't closed in terms of asking write_object_file() to be silent. I.e. post-9c4d6c0297b the first call is to prepare_index(), and after that we'll call prepare_to_commit(). We only want verbose error output from the latter. So let's add and use that facility with a corresponding HASH_SILENT flag, its only user is cache-tree.c's update_one(), which will set it if its "WRITE_TREE_SILENT" flag is set. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Jonathan Tan	eef71904ff	object-file: only register submodule ODB if needed In `a35e03dee0` ("submodule: lazily add submodule ODBs as alternates", 2021-09-08), Git was taught to add all known submodule ODBs as alternates when attempting to read an object that doesn't exist, as a fallback for when a submodule object is read as if it were in the_repository. However, this behavior wasn't restricted to happen only when reading from the_repository. Fix this. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	96e41f58fe	fsck: report invalid object type-path combinations Improve the error that's emitted in cases where we find a loose object we parse, but which isn't at the location we expect it to be. Before this change we'd prefix the error with a not-a-OID derived from the path at which the object was found, due to an emergent behavior in how we'd end up with an "OID" in these codepaths. Now we'll instead say what object we hashed, and what path it was found at. Before this patch series e.g.: $ git hash-object --stdin -w -t blob </dev/null `e69de29bb2` $ mv objects/e6/ objects/e7 Would emit ("[...]" used to abbreviate the OIDs): git fsck error: hash mismatch for ./objects/e7/9d[...] (expected e79d[...]) error: e79d[...]: object corrupt or missing: ./objects/e7/9d[...] Now we'll instead emit: error: e69d[...]: hash-path mismatch, found at: ./objects/e7/9d[...] Furthermore, we'll do the right thing when the object type and its location are bad. I.e. this case: $ git hash-object --stdin -w -t garbage --literally </dev/null 8315a83d2acc4c174aed59430f9a9c4ed926440f $ mv objects/83 objects/84 As noted in an earlier commits we'd simply die early in those cases, until preceding commits fixed the hard die on invalid object type: $ git fsck fatal: invalid object type Now we'll instead emit sensible error messages: $ git fsck error: 8315[...]: hash-path mismatch, found at: ./objects/84/15[...] error: 8315[...]: object is of unknown type 'garbage': ./objects/84/15[...] In both fsck.c and object-file.c we're using null_oid as a sentinel value for checking whether we got far enough to be certain that the issue was indeed this OID mismatch. We need to add the "object corrupt or missing" special-case to deal with cases where read_loose_object() will return an error before completing check_object_signature(), e.g. if we have an error in unpack_loose_rest() because we find garbage after the valid gzip content: $ git hash-object --stdin -w -t blob </dev/null `e69de29bb2` $ chmod 755 objects/e6/9de29bb2d1d6434b8b29ae775ad8c2e48c5391 $ echo garbage >>objects/e6/9de29bb2d1d6434b8b29ae775ad8c2e48c5391 $ git fsck error: garbage at end of loose object 'e69d[...]' error: unable to unpack contents of ./objects/e6/9d[...] error: e69d[...]: object corrupt or missing: ./objects/e6/9d[...] There is currently some weird messaging in the edge case when the two are combined, i.e. because we're not explicitly passing along an error state about this specific scenario from check_stream_oid() via read_loose_object() we'll end up printing the null OID if an object is of an unknown type and it can't be unpacked by zlib, e.g.: $ git hash-object --stdin -w -t garbage --literally </dev/null 8315a83d2acc4c174aed59430f9a9c4ed926440f $ chmod 755 objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f $ echo garbage >>objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f $ /usr/bin/git fsck fatal: invalid object type $ ~/g/git/git fsck error: garbage at end of loose object '8315a83d2acc4c174aed59430f9a9c4ed926440f' error: unable to unpack contents of ./objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f error: 8315a83d2acc4c174aed59430f9a9c4ed926440f: object corrupt or missing: ./objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f error: 0000000000000000000000000000000000000000: object is of unknown type 'garbage': ./objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f [...] I think it's OK to leave that for future improvements, which would involve enum-ifying more error state as we've done with "enum unpack_loose_header_result" in preceding commits. In these increasingly more obscure cases the worst that can happen is that we'll get slightly nonsensical or inapplicable error messages. There's other such potential edge cases, all of which might produce some confusing messaging, but still be handled correctly as far as passing along errors goes. E.g. if check_object_signature() returns and oideq(real_oid, null_oid()) is true, which could happen if it returns -1 due to the read_istream() call having failed. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	31deb28f5e	fsck: don't hard die on invalid object types Change the error fsck emits on invalid object types, such as: $ git hash-object --stdin -w -t garbage --literally </dev/null <OID> From the very ungraceful error of: $ git fsck fatal: invalid object type $ To: $ git fsck error: <OID>: object is of unknown type 'garbage': <OID_PATH> [ other fsck output ] We'll still exit with non-zero, but now we'll finish the rest of the traversal. The tests that's being added here asserts that we'll still complain about other fsck issues (e.g. an unrelated dangling blob). To do this we need to pass down the "OBJECT_INFO_ALLOW_UNKNOWN_TYPE" flag from read_loose_object() through to parse_loose_header(). Since the read_loose_object() function is only used in builtin/fsck.c we can simply change it to accept a "struct object_info" (which contains the OBJECT_INFO_ALLOW_UNKNOWN_TYPE in its flags). See `f6371f9210` (sha1_file: add read_loose_object() function, 2017-01-13) for the introduction of read_loose_object(). Since we'll need a "struct strbuf" to hold the "type_name" let's pass it to the for_each_loose_file_in_objdir() callback to avoid allocating a new one for each loose object in the iteration. It also makes the memory management simpler than sticking it in fsck_loose() itself, as we'll only need to strbuf_reset() it, with no need to do a strbuf_release() before each "return". Before this commit we'd never check the "type" if read_loose_object() failed, but now we do. We therefore need to initialize it to OBJ_NONE to be able to tell the difference between e.g. its unpack_loose_header() having failed, and us getting past that and into parse_loose_header(). Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	dccb32bf01	object-file.c: stop dying in parse_loose_header() Make parse_loose_header() return error codes and data instead of invoking die() by itself. For now we'll move the relevant die() call to loose_object_info() and read_loose_object() to keep this change smaller. In a subsequent commit we'll make read_loose_object() return an error code instead of dying. We should also address the "allow_unknown" case (should be moved to builtin/cat-file.c), but for now I'll be leaving it. For making parse_loose_header() not die() change its prototype to accept a "struct object_info " instead of the "unsigned long sizep" it accepted before. Its callers can now check the populated populated "oi->typep". Because of this we don't need to pass in the "unsigned int flags" which we used for OBJECT_INFO_ALLOW_UNKNOWN_TYPE, we can instead do that check in loose_object_info(). This also refactors some confusing control flow around the "status" variable. In some cases we set it to the return value of "error()", i.e. -1, and later checked if "status < 0" was true. Since `93cff9a978` (sha1_loose_object_info: return error for corrupted objects, 2017-04-01) the return value of loose_object_info() (then named sha1_loose_object_info()) had been a "status" variable that be any negative value, as we were expecting to return the "enum object_type". The only negative type happens to be OBJ_BAD, but the code still assumed that more might be added. This was then used later in e.g. `c84a1f3ed4` (sha1_file: refactor read_object, 2017-06-21). Now that parse_loose_header() will return 0 on success instead of the type (which it'll stick into the "struct object_info") we don't need to conflate these two cases in its callers. Since parse_loose_header() doesn't need to return an arbitrary "status" we only need to treat its "ret < 0" specially, but can idiomatically overwrite it with our own error() return. This along with having made unpack_loose_header() return an "enum unpack_loose_header_result" in an earlier commit means that we can move the previously nested if/else cases mostly into the "ULHR_OK" branch of the "switch" statement. We should be less silent if we reach that "status = -1" branch, which happens if we've got trailing garbage in loose objects, see `f6371f9210` (sha1_file: add read_loose_object() function, 2017-01-13) for a better way to handle it. For now let's punt on it, a subsequent commit will address that edge case. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	5848fb11ac	object-file.c: return ULHR_TOO_LONG on "header too long" Split up the return code for "header too long" from the generic negative return value unpack_loose_header() returns, and report via error() if we exceed MAX_HEADER_LEN. As a test added earlier in this series in t1006-cat-file.sh shows we'll correctly emit zlib errors from zlib.c already in this case, so we have no need to carry those return codes further down the stack. Let's instead just return ULHR_TOO_LONG saying we ran into the MAX_HEADER_LEN limit, or other negative values for "unable to unpack <OID> header". Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	3b6a8db3b0	object-file.c: use "enum" return type for unpack_loose_header() In a preceding commit we changed and documented unpack_loose_header() from its previous behavior of returning any negative value or zero, to only -1 or 0. Let's add an "enum unpack_loose_header_result" type and use it for these return values, and have the compiler assert that we're exhaustively covering all of them. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	01cab97679	object-file.c: simplify unpack_loose_short_header() Combine the unpack_loose_short_header(), unpack_loose_header_to_strbuf() and unpack_loose_header() functions into one. The unpack_loose_header_to_strbuf() function was added in `46f034483e` (sha1_file: support reading from a loose object of unknown type, 2015-05-03). Its code was mostly copy/pasted between it and both of unpack_loose_header() and unpack_loose_short_header(). We now have a single unpack_loose_header() function which accepts an optional "struct strbuf *" instead. I think the remaining unpack_loose_header() function could be further simplified, we're carrying some complexity just to be able to emit a garbage type longer than MAX_HEADER_LEN, we could alternatively just say "we found a garbage type <first 32 bytes>..." instead. But let's leave the current behavior in place for now. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	ddb3474b66	object-file.c: make parse_loose_header_extended() public Make the parse_loose_header_extended() function public and remove the parse_loose_header() wrapper. The only direct user of it outside of object-file.c itself was in streaming.c, that caller can simply pass the required "struct object-info *" instead. This change is being done in preparation for teaching read_loose_object() to accept a flag to pass to parse_loose_header(). It isn't strictly necessary for that change, we could simply use parse_loose_header_extended() there, but will leave the API in a better end state. It would be a better end-state to have already moved the declaration of these functions to object-store.h to avoid the forward declaration of "struct object_info" in cache.h, but let's leave that cleanup for some other time. 1. https://lore.kernel.org/git/patch-v6-09.22-5b9278e7bb4-20210907T104559Z-avarab@gmail.com/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	bfff2c4833	object-file.c: return -1, not "status" from unpack_loose_header() Return a -1 when git_inflate() fails instead of whatever Z_* status we'd get from zlib.c. This makes no difference to any error we report, but makes it more obvious that we don't care about the specific zlib error codes here. See `d21f842690` (unpack_sha1_header(): detect malformed object header, 2016-09-25) for the commit that added the "return status" code. As far as I can tell there was never a real reason (e.g. different reporting) for carrying down the "status" as opposed to "-1". At the time that `d21f842690` was written there was a corresponding "ret < Z_OK" check right after the unpack_sha1_header() call (the "unpack_sha1_header()" function was later rename to our current "unpack_loose_header()"). However, that check was removed in `c84a1f3ed4` (sha1_file: refactor read_object, 2017-06-21) without changing the corresponding return code. So let's do the minor cleanup of also changing this function to return a -1. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
Ævar Arnfjörð Bjarmason	74ad250a1c	object-file.c: don't set "typep" when returning non-zero When the loose_object_info() function returns an error stop faking up the "oi->typep" to OBJ_BAD. Let the return value of the function itself suffice. This code cleanup simplifies subsequent changes. That we set this at all is a relic from the past. Before `052fe5eaca` (sha1_loose_object_info: make type lookup optional, 2013-07-12) we would always return the type_from_string(type) via the parse_sha1_header() function, or -1 (i.e. OBJ_BAD) if we couldn't parse it. Then in a combination of `46f034483e` (sha1_file: support reading from a loose object of unknown type, 2015-05-03) and `b3ea7dd32d` (sha1_loose_object_info: handle errors from unpack_sha1_rest, 2017-10-05) our API drifted even further towards conflating the two again. Having read the code paths involved carefully I think this is OK. We are just about to return -1, and we have only one caller: do_oid_object_info_extended(). That function will in turn go on to return -1 when we return -1 here. This might be introducing a subtle bug where a caller of oid_object_info_extended() would inspect its "typep" and expect a meaningful value if the function returned -1. Such a problem would not occur for its simpler oid_object_info() sister function. That one always returns the "enum object_type", which in the case of -1 would be the OBJ_BAD. Having read the code for all the callers of these functions I don't believe any such bug is being introduced here, and in any case we'd likely already have such a bug for the "sizep" member (although blindly checking "typep" first would be a more common case). Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	3 years ago
René Scharfe	7407d733a4	packfile: convert has_packed_and_bad() to object_id The single caller has a full object ID, so pass it on instead of just its hash member. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
René Scharfe	751530de5d	packfile: convert mark_bad_packed_object() to object_id All callers have full object IDs, so pass them on instead of just their hash member. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	a35e03dee0	submodule: lazily add submodule ODBs as alternates Teach Git to add submodule ODBs as alternates to the object store of the_repository only upon the first access of an object not in the_repository, and not when add_submodule_odb() is called. This provides a means of gradually migrating from accessing a submodule's object through alternates to accessing a submodule's object by explicitly passing its repository object. Any Git command can declare that it might access submodule objects by calling add_submodule_odb() (as they do now), but the submodule ODBs themselves will not be added until needed, so individual commands and/or combinations of arguments can be migrated one by one. [The advantage of explicit repository-object passing is code clarity (it is clear which repository an object read is from), performance (there is no need to linearly search through all submodule ODBs whenever an object is accessed from any repository, whether superproject or submodule), and the possibility of future features like partial clone submodules (which right now is not possible because if an object is missing, we do not know which repository to lazy-fetch into).] This commit also introduces an environment variable that a test may set to make the actual registration of alternates fatal, in order to demonstrate that its codepaths do not need this registration. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Reviewed-by: Emily Shaffer <emilyshaffer@google.com> Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Han-Wen Nienhuys	27f3796ac1	hash.h: provide constants for the hash IDs This will simplify referencing them from code that is not deeply integrated with Git, in particular, the reftable library. Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Taylor Blau	f57a739691	midx: avoid opening multiple MIDXs when writing Opening multiple instance of the same MIDX can lead to problems like two separate packed_git structures which represent the same pack being added to the repository's object store. The above scenario can happen because prepare_midx_pack() checks if `m->packs[pack_int_id]` is NULL in order to determine if a pack has been opened and installed in the repository before. But a caller can construct two copies of the same MIDX by calling get_multi_pack_index() and load_multi_pack_index() since the former manipulates the object store directly but the latter is a lower-level routine which allocates a new MIDX for each call. So if prepare_midx_pack() is called on multiple MIDXs with the same pack_int_id, then that pack will be installed twice in the object store's packed_git pointer. This can lead to problems in, for e.g., the pack-bitmap code, which does something like the following (in pack-bitmap.c:open_pack_bitmap()): struct bitmap_index bitmap_git = ...; for (p = get_all_packs(r); p; p = p->next) { if (open_pack_bitmap_1(bitmap_git, p) == 0) ret = 0; } which is a problem if two copies of the same pack exist in the packed_git list because pack-bitmap.c:open_pack_bitmap_1() contains a conditional like the following: if (bitmap_git->pack \|\| bitmap_git->midx) { / ignore extra bitmap file; we can only handle one / warning("ignoring extra bitmap file: %s", packfile->pack_name); close(fd); return -1; } Avoid this scenario by not letting write_midx_internal() open a MIDX that isn't also pointed at by the object store. So long as this is the case, other routines should prefer to open MIDXs with get_multi_pack_index() or reprepare_packed_git() instead of creating instances on their own. Because get_multi_pack_index() returns `r->object_store->multi_pack_index` if it is non-NULL, we'll only have one instance of a MIDX open at one time, avoiding these problems. To encourage this, drop the `struct multi_pack_index ` parameter from `write_midx_internal()`, and rely instead on the `object_dir` to find (or initialize) the correct MIDX instance. Likewise, replace the call to `close_midx()` with `close_object_store()`, since we're about to replace the MIDX with a new one and should invalidate the object store's memory of any MIDX that might have existed beforehand. Note that this now forbids passing object directories that don't belong to alternate repositories over `--object-dir`, since before we would have happily opened a MIDX in any directory, but now restrict ourselves to only those reachable by `r->objects->multi_pack_index` (and alternate MIDXs that we can see by walking the `next` pointer). As far as I can tell, supporting arbitrary directories with `--object-dir` was a historical accident, since even the documentation says `<alt>` when referring to the value passed to this option. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Ævar Arnfjörð Bjarmason	3fa2e91d17	refs file backend: move raceproof_create_file() here Move the raceproof_create_file() API added to cache.h and object-file.c in `177978f56a` (raceproof_create_file(): new function, 2017-01-06) to its only user, refs/files-backend.c. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
René Scharfe	581a3bb155	object-file: use unsigned arithmetic with bit mask `33f379eee6` (make object_directory.loose_objects_subdir_seen a bitmap, 2021-07-07) replaced a wasteful 256-byte array with a 32-byte array and bit operations. The mask calculation shifts a literal 1 of type int left by anything between 0 and 31. UndefinedBehaviorSanitizer doesn't like that and reports: object-file.c:2477:18: runtime error: left shift of 1 by 31 places cannot be represented in type 'int' Make sure to use an unsigned 1 instead to avoid the issue. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Eric Wong	92d8ed8ac1	oidtree: a crit-bit tree for odb_loose_cache This saves 8K per `struct object_directory', meaning it saves around 800MB in my case involving 100K alternates (half or more of those alternates are unlikely to hold loose objects). This is implemented in two parts: a generic, allocation-free `cbtree' and the `oidtree' wrapper on top of it. The latter provides allocation using alloc_state as a memory pool to improve locality and reduce free(3) overhead. Unlike oid-array, the crit-bit tree does not require sorting. Performance is bound by the key length, for oidtree that is fixed at sizeof(struct object_id). There's no need to have 256 oidtrees to mitigate the O(n log n) overhead like we did with oid-array. Being a prefix trie, it is natively suited for expanding short object IDs via prefix-limited iteration in `find_short_object_filename'. On my busy workstation, p4205 performance seems to be roughly unchanged (+/-8%). Startup with 100K total alternates with no loose objects seems around 10-20% faster on a hot cache. (800MB in memory savings means more memory for the kernel FS cache). The generic cbtree implementation does impose some extra overhead for oidtree in that it uses memcmp(3) on "struct object_id" so it wastes cycles comparing 12 extra bytes on SHA-1 repositories. I've not yet explored reducing this overhead, but I expect there are many places in our code base where we'd want to investigate this. More information on crit-bit trees: https://cr.yp.to/critbit.html Signed-off-by: Eric Wong <e@80x24.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Eric Wong	33f379eee6	make object_directory.loose_objects_subdir_seen a bitmap There's no point in using 8 bits per-directory when 1 bit will do. This saves us 224 bytes per object directory, which ends up being 22MB when dealing with 100K alternates. Signed-off-by: Eric Wong <e@80x24.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Eric Wong	407532f82d	avoid strlen via strbuf_addstr in link_alt_odb_entry We can save a few milliseconds (across 100K odbs) by using strbuf_addbuf() instead of strbuf_addstr() by passing `entry' as a strbuf pointer rather than a "const char *". Signed-off-by: Eric Wong <e@80x24.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Eric Wong	cf2dc1c238	speed up alt_odb_usable() with many alternates With many alternates, the duplicate check in alt_odb_usable() wastes many cycles doing repeated fspathcmp() on every existing alternate. Use a khash to speed up lookups by odb->path. Since the kh_put_* API uses the supplied key without duplicating it, we also take advantage of it to replace both xstrdup() and strbuf_release() in link_alt_odb_entry() with strbuf_detach() to avoid the allocation and copy. In a test repository with 50K alternates and each of those 50K alternates having one alternate each (for a total of 100K total alternates); this speeds up lookup of a non-existent blob from over 16 minutes to roughly 2.7 seconds on my busy workstation. Note: all underlying git object directories were small and unpacked with only loose objects and no packs. Having to load packs increases times significantly. Signed-off-by: Eric Wong <e@80x24.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Eric Wong	dc05929411	xmmap: inform Linux users of tuning knobs on ENOMEM Linux users may benefit from additional information on how to avoid ENOMEM from mmap despite the system having enough RAM to accomodate them. We can't reliably unmap pack windows to work around the issue since malloc and other library routines may mmap without our knowledge. Signed-off-by: Eric Wong <e@80x24.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	ef830cc434	promisor-remote: teach lazy-fetch in any repo This is one step towards supporting partial clone submodules. Even after this patch, we will still lack partial clone submodules support, primarily because a lot of Git code that accesses submodule objects does so by adding their object stores as alternates, meaning that any lazy fetches that would occur in the submodule would be done based on the config of the superproject, not of the submodule. This also prevents testing of the functionality in this patch by user-facing commands. So for now, test this mechanism using a test helper. Besides that, there is some code that uses the wrapper functions like has_promisor_remote(). Those will need to be checked to see if they could support the non-wrapper functions instead (and thus support any repository, not just the_repository). Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Elijah Newren	906fc557b7	dir: introduce readdir_skip_dot_and_dotdot() helper Many places in the code were doing while ((d = readdir(dir)) != NULL) { if (is_dot_or_dotdot(d->d_name)) continue; ...process d... } Introduce a readdir_skip_dot_and_dotdot() helper to make that a one-liner: while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) { ...process d... } This helper particularly simplifies checks for empty directories. Also use this helper in read_cached_dir() so that our statistics are consistent across platforms. (In other words, read_cached_dir() should have been using is_dot_or_dotdot() and skipping such entries, but did not and left it to treat_path() to detect and mark such entries as path_none.) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Junio C Hamano	1df046bcff	Revert "dir: introduce readdir_skip_dot_and_dotdot() helper" This reverts commit `b548f0f156`, to be replaced with a reworked version.	4 years ago
Elijah Newren	b548f0f156	dir: introduce readdir_skip_dot_and_dotdot() helper Many places in the code were doing while ((d = readdir(dir)) != NULL) { if (is_dot_or_dotdot(d->d_name)) continue; ...process d... } Introduce a readdir_skip_dot_and_dotdot() helper to make that a one-liner: while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) { ...process d... } This helper particularly simplifies checks for empty directories. Also use this helper in read_cached_dir() so that our statistics are consistent across platforms. (In other words, read_cached_dir() should have been using is_dot_or_dotdot() and skipping such entries, but did not and left it to treat_path() to detect and mark such entries as path_none.) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
brian m. carlson	14228447c9	hash: provide per-algorithm null OIDs Up until recently, object IDs did not have an algorithm member, only a hash. Consequently, it was possible to share one null (all-zeros) object ID among all hash algorithms. Now that we're going to be handling objects from multiple hash algorithms, it's important to make sure that all object IDs have a correct algorithm field. Introduce a per-algorithm null OID, and add it to struct hash_algo. Introduce a wrapper function as well, and use it everywhere we used to use the null_oid constant. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
brian m. carlson	5a6dce70d7	hash: set, copy, and use algo field in struct object_id Now that struct object_id has an algorithm field, we should populate it. This will allow us to handle object IDs in any supported algorithm and distinguish between them. Ensure that the field is written whenever we write an object ID by storing it explicitly every time we write an object. Set values for the empty blob and tree values as well. In addition, use the algorithm field to compare object IDs. Note that because we zero-initialize struct object_id in many places throughout the codebase, we default to the default algorithm in cases where the algorithm field is zero rather than explicitly initialize all of those locations. This leads to a branch on every comparison, but the alternative is to compare the entire buffer each time and padding the buffer for SHA-1. That alternative ranges up to 3.9% worse than this approach on the perf t0001, t1450, and t1451. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
brian m. carlson	5951bf467e	Use the final_oid_fn to finalize hashing of object IDs When we're hashing a value which is going to be an object ID, we want to zero-pad that value if necessary. To do so, use the final_oid_fn instead of the final_fn anytime we're going to create an object ID to ensure we perform this operation. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
brian m. carlson	ab795f0d77	hash: add a function to finalize object IDs To avoid the penalty of having to branch in hash comparison functions, we'll want to always compare the full hash member in a struct object_id, which will require that SHA-1 object IDs be zero-padded. To do so, add a function which finalizes a hash context and writes it into an object ID that performs this padding. Move the definition of struct object_id and the constant definitions higher up so we they are available for us to use. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> 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
Martin Ågren	bc62692757	hash-lookup: rename from sha1-lookup Change all remnants of "sha1" in hash-lookup.c and .h and rename them to reflect that we're not just able to handle SHA-1 these days. Signed-off-by: Martin Ågren <martin.agren@gmail.com> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Martin Ågren	e5afd4449d	object-file.c: rename from sha1-file.c Drop the last remnant of "sha1" in this file and rename it to reflect that we're not just able to handle SHA-1 these days. Signed-off-by: Martin Ågren <martin.agren@gmail.com> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Matheus Tavares	eb3c027e17	apply: don't use core.sharedRepository to create working tree files core.sharedRepository defines which permissions Git should set when creating files in $GIT_DIR, so that the repository may be shared with other users. But (in its current form) the setting shouldn't affect how files are created in the working tree. This is not respected by apply and am (which uses apply), when creating leading directories: $ cat d.patch diff --git a/d/f b/d/f new file mode 100644 index 0000000..e69de29 Apply without the setting: $ umask 0077 $ git apply d.patch $ ls -ld d drwx------ Apply with the setting: $ umask 0077 $ git -c core.sharedRepository=0770 apply d.patch $ ls -ld d drwxrws--- Only the leading directories are affected. That's because they are created with safe_create_leading_directories(), which calls adjust_shared_perm() to set the directories' permissions based on core.sharedRepository. To fix that, let's introduce a variant of this function that ignores the setting, and use it in apply. Also add a regression test and a note in the function documentation about the use of each variant according to the destination (working tree or git dir). Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jonathan Tan	1d8d9cb620	sha1-file: introduce no-lazy-fetch has_object() There have been a few bugs wherein Git fetches missing objects whenever the existence of an object is checked, even though it does not need to perform such a fetch. To resolve these bugs, we could look at all the places that has_object_file() (or a similar function) is used. As a first step, introduce a new function has_object() that checks for the existence of an object, with a default behavior of not fetching if the object is missing and the repository is a partial clone. As we verify each has_object_file() (or similar) usage, we can replace it with has_object(), and we will know that we are done when we can delete has_object_file() (and the other similar functions). Also, the new function has_object() has more appropriate defaults: besides not fetching, it also does not recheck packed storage. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Jeff King	c972bf4cf5	strvec: convert remaining 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 all of the remaining files, as the resulting diff is reasonably sized. 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; ' 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	a64d2aae5a	sha1-file: make pretend_object_file() not prefetch When pretend_object_file() is invoked with an object that does not exist (as is the typical case), there is no need to fetch anything from the promisor remote, because the caller already knows what the object is supposed to contain. Therefore, suppress the fetch. (The OBJECT_INFO_QUICK flag is added for the same reason.) This was noticed at $DAYJOB when "blame" was run on a file that had uncommitted modifications. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
luciano.rocha@booking.com	312cd76130	freshen_file(): use NULL `times' for implicit current-time Update freshen_file() to use a NULL `times', semantically equivalent to the currently setup, with an explicit `actime' and `modtime' set to the "current time", but with the advantage that it works with other files not owned by the current user. Fixes an issue on shared repos with a split index, where eventually a user's operation creates a shared index, and another user will later do an operation that will try to update its freshness, but will instead raise a warning: $ git status warning: could not freshen shared index '.git/sharedindex.bd736fa10e0519593fefdb2aec253534470865b2' Signed-off-by: Luciano Miguel Ferreira Rocha <luciano.rocha@booking.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Alexandr Miloslavskiy	4530a85b4c	real_path_if_valid(): remove unsafe API This commit continues the work started with previous commit. Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Jeff King	b99b6bcc57	packed_object_info(): use object_id for returning delta base If a caller sets the object_info.delta_base_sha1 to a non-NULL pointer, we'll write the oid of the object's delta base to it. But we can increase our type safety by switching this to a real object_id struct. All of our callers are just pointing into the hash member of an object_id anyway, so there's no inconvenience. Note that we do still keep it as a pointer-to-struct, because the NULL sentinel value tells us whether the caller is even interested in the information. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
brian m. carlson	768e30ea27	hash: implement and use a context cloning function For all of our SHA-1 implementations and most of our SHA-256 implementations, the hash context we use is a real struct. For these implementations, it's possible to copy a hash context by making a copy of the struct. However, for our libgcrypt implementation, our hash context is a pointer. Consequently, copying it does not lead to an independent hash context like we intended. Fortunately, however, libgcrypt provides us with a handy function to copy hash contexts. Let's add a cloning function to the hash algorithm API, and use it in the one place we need to make a hash context copy. With this change, our libgcrypt SHA-256 implementation is fully functional with all of our other hash implementations. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Matheus Tavares	b98d188581	sha1-file: allow check_object_signature() to handle any repo Some callers of check_object_signature() can work on arbitrary repositories, but the repo does not get passed to this function. Instead, the_repository is always used internally. To fix possible inconsistencies, allow the function to receive a struct repository and make those callers pass on the repo being handled. Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago

1 2

55 Commits (544d93bc3b459f6e40526acdcf36a14c3d5dfec6)