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2019-10-28fsck: only provide oid/type in fsck_error callbackJeff King
None of the callbacks actually care about having a "struct object"; they're happy with just the oid and type information. So let's give ourselves more flexibility to avoid having a "struct object" by just passing the broken-down fields. Note that the callback already takes a "type" field for the fsck message type. We'll rename that to "msg_type" (and use "object_type" for the object type) to make the distinction explicit. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: use oids rather than objects for object_name APIJeff King
We don't actually care about having object structs; we only need to look up decorations by oid. Let's accept this more limited form, which will give our callers more flexibility. Note that the decoration API we rely on uses object structs itself (even though it only looks at their oids). We can solve this by switching to a kh_oid_map (we could also use the hashmap oidmap, but it's more awkward for the simple case of just storing a void pointer). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: unify object-name codeJeff King
Commit 90cf590f53 (fsck: optionally show more helpful info for broken links, 2016-07-17) added a system for decorating objects with names. The code is split across builtin/fsck.c (which gives the initial names) and fsck.c (which adds to the names as it traverses the object graph). This leads to some duplication, where both sites have near-identical describe_object() functions (the difference being that the one in builtin/fsck.c uses a circular array of buffers to allow multiple calls in a single printf). Let's provide a unified object_name API for fsck. That lets us drop the duplication, as well as making the interface boundaries more clear (which will let us refactor the implementation more in a future patch). We'll leave describe_object() in builtin/fsck.c as a thin wrapper around the new API, as it relies on a static global to make its many callers a bit shorter. We'll also convert the bare add_decoration() calls in builtin/fsck.c to put_object_name(). This fixes two minor bugs: 1. We leak many small strings. add_decoration() has a last-one-wins approach: it updates the decoration to the new string and returns the old one. But we ignore the return value, leaking the old string. This is quite common to trigger, since we look at reflogs: the tip of any ref will be described both by looking at the actual ref, as well as the latest reflog entry. So we'd always end up leaking one of those strings. 2. The last-one-wins approach gives us lousy names. For instance, we first look at all of the refs, and then all of the reflogs. So rather than seeing "refs/heads/master", we're likely to overwrite it with "HEAD@{12345678}". We're generally better off using the first name we find. And indeed, the test in t1450 expects this ugly HEAD@{} name. After this patch, we've switched to using fsck_put_object_name()'s first-one-wins semantics, and we output the more human-friendly "refs/tags/julius" (and the test is updated accordingly). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: require an actual buffer for non-blobsJeff King
The fsck_object() function takes in a buffer, but also a "struct object". The rules for using these vary between types: - for a commit, we'll use the provided buffer; if it's NULL, we'll fall back to get_commit_buffer(), which loads from either an in-memory cache or from disk. If the latter fails, we'd die(), which is non-ideal for fsck. - for a tag, a NULL buffer will fall back to loading the object from disk (and failure would lead to an fsck error) - for a tree, we _never_ look at the provided buffer, and always use tree->buffer - for a blob, we usually don't look at the buffer at all, unless it has been marked as a .gitmodule file. In that case we check the buffer given to us, or assume a NULL buffer is a very large blob (and complain about it) This is much more complex than it needs to be. It turns out that nobody ever feeds a NULL buffer that isn't a blob: - git-fsck calls fsck_object() only from fsck_obj(). That in turn is called by one of: - fsck_obj_buffer(), which is a callback to verify_pack(), which unpacks everything except large blobs into a buffer (see pack-check.c, lines 131-141). - fsck_loose(), which hits a BUG() on non-blobs with a NULL buffer (builtin/fsck.c, lines 639-640) And in either case, we'll have just called parse_object_buffer() anyway, which would segfault on a NULL buffer for commits or tags (not for trees, but it would install a NULL tree->buffer which would later cause a segfault) - git-index-pack asserts that the buffer is non-NULL unless the object is a blob (see builtin/index-pack.c, line 832) - git-unpack-objects always writes a non-NULL buffer into its obj_buffer hash, which is then fed to fsck_object(). (There is actually a funny thing here where it does not store blob buffers at all, nor does it call fsck on them; it does check any needed blobs via fsck_finish() though). Let's make the rules simpler, which reduces the amount of code and gives us more flexibility in refactoring the fsck code. The new rules are: - only blobs are allowed to pass a NULL buffer - we always use the provided buffer, never pulling information from the object struct We don't have to adjust any callers, because they were already adhering to these. Note that we do drop a few fsck identifiers for missing tags, but that was all dead code (because nobody passed a NULL tag buffer). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-12fsck: use oidset instead of oid_array for skipListRené Scharfe
Change the implementation of the skipList feature to use oidset instead of oid_array to store SHA-1s for later lookup. This list is parsed once on startup by fsck, fetch-pack or receive-pack depending on the *.skipList config in use. I.e. only once per invocation, but note that for "clone --recurse-submodules" each submodule will re-parse the list, in addition to the main project, and it will be re-parsed when checking .gitmodules blobs, see fb16287719 ("fsck: check skiplist for object in fsck_blob()", 2018-06-27). Memory usage is a bit higher, but we don't need to keep track of the sort order anymore. Embed the oidset into struct fsck_options to make its ownership clear (no hidden sharing) and avoid unnecessary pointer indirection. The cumulative impact on performance of this & the preceding change, using the test setup described in the previous commit: Test HEAD~2 HEAD~ HEAD ---------------------------------------------------------------------------------------------------------------- 1450.3: fsck with 0 skipped bad commits 7.70(7.31+0.38) 7.72(7.33+0.38) +0.3% 7.70(7.30+0.40) +0.0% 1450.5: fsck with 1 skipped bad commits 7.84(7.47+0.37) 7.69(7.32+0.36) -1.9% 7.71(7.29+0.41) -1.7% 1450.7: fsck with 10 skipped bad commits 7.81(7.40+0.40) 7.94(7.57+0.36) +1.7% 7.92(7.55+0.37) +1.4% 1450.9: fsck with 100 skipped bad commits 7.81(7.42+0.38) 7.95(7.53+0.41) +1.8% 7.83(7.42+0.41) +0.3% 1450.11: fsck with 1000 skipped bad commits 7.99(7.62+0.36) 7.90(7.50+0.40) -1.1% 7.86(7.49+0.37) -1.6% 1450.13: fsck with 10000 skipped bad commits 7.98(7.57+0.40) 7.94(7.53+0.40) -0.5% 7.90(7.45+0.44) -1.0% 1450.15: fsck with 100000 skipped bad commits 7.97(7.57+0.39) 8.03(7.67+0.36) +0.8% 7.84(7.43+0.41) -1.6% 1450.17: fsck with 1000000 skipped bad commits 7.72(7.22+0.50) 7.28(7.07+0.20) -5.7% 7.13(6.87+0.25) -7.6% Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-15Add missing includes and forward declarationsElijah Newren
I looped over the toplevel header files, creating a temporary two-line C program for each consisting of #include "git-compat-util.h" #include $HEADER This patch is the result of manually fixing errors in compiling those tiny programs. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-22fsck: detect gitmodules filesJeff King
In preparation for performing fsck checks on .gitmodules files, this commit plumbs in the actual detection of the files. Note that unlike most other fsck checks, this cannot be a property of a single object: we must know that the object is found at a ".gitmodules" path at the root tree of a commit. Since the fsck code only sees one object at a time, we have to mark the related objects to fit the puzzle together. When we see a commit we mark its tree as a root tree, and when we see a root tree with a .gitmodules file, we mark the corresponding blob to be checked. In an ideal world, we'd check the objects in topological order: commits followed by trees followed by blobs. In that case we can avoid ever loading an object twice, since all markings would be complete by the time we get to the marked objects. And indeed, if we are checking a single packfile, this is the order in which Git will generally write the objects. But we can't count on that: 1. git-fsck may show us the objects in arbitrary order (loose objects are fed in sha1 order, but we may also have multiple packs, and we process each pack fully in sequence). 2. The type ordering is just what git-pack-objects happens to write now. The pack format does not require a specific order, and it's possible that future versions of Git (or a custom version trying to fool official Git's fsck checks!) may order it differently. 3. We may not even be fscking all of the relevant objects at once. Consider pushing with transfer.fsckObjects, where one push adds a blob at path "foo", and then a second push adds the same blob at path ".gitmodules". The blob is not part of the second push at all, but we need to mark and check it. So in the general case, we need to make up to three passes over the objects: once to make sure we've seen all commits, then once to cover any trees we might have missed, and then a final pass to cover any .gitmodules blobs we found in the second pass. We can simplify things a bit by loosening the requirement that we find .gitmodules only at root trees. Technically a file like "subdir/.gitmodules" is not parsed by Git, but it's not unreasonable for us to declare that Git is aware of all ".gitmodules" files and make them eligible for checking. That lets us drop the root-tree requirement, which eliminates one pass entirely. And it makes our worst case much better: instead of potentially queueing every root tree to be re-examined, the worst case is that we queue each unique .gitmodules blob for a second look. This patch just adds the boilerplate to find .gitmodules files. The actual content checks will come in a subsequent commit. Signed-off-by: Jeff King <peff@peff.net>
2017-03-31Rename sha1_array to oid_arraybrian m. carlson
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>
2016-07-18fsck: give the error function a chance to see the fsck_optionsJohannes Schindelin
We will need this in the next commit, where fsck will be taught to optionally name the objects when reporting issues about them. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-18fsck_walk(): optionally name objects on the goJohannes Schindelin
If fsck_options->name_objects is initialized, and if it already has name(s) for the object(s) that are to be the starting point(s) for fsck_walk(), then that function will now add names for the objects that were walked. This will be highly useful for teaching git-fsck to identify root causes for broken links, which is the task for the next patch in this series. Note that this patch opts for decorating the objects with plain strings instead of full-blown structs (à la `struct rev_name` in the code of the `git name-rev` command), for several reasons: - the code is much simpler than if it had to work with structs that describe arbitrarily long names such as "master~14^2~5:builtin/am.c", - the string processing is actually quite light-weight compared to the rest of fsck's operation, - the caller of fsck_walk() is expected to provide names for the starting points, and using plain and simple strings is just the easiest way to do that. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-23fsck: git receive-pack: support excluding objects from fsck'ingJohannes Schindelin
The optional new config option `receive.fsck.skipList` specifies the path to a file listing the names, i.e. SHA-1s, one per line, of objects that are to be ignored by `git receive-pack` when `receive.fsckObjects = true`. This is extremely handy in case of legacy repositories where it would cause more pain to change incorrect objects than to live with them (e.g. a duplicate 'author' line in an early commit object). The intended use case is for server administrators to inspect objects that are reported by `git push` as being too problematic to enter the repository, and to add the objects' SHA-1 to a (preferably sorted) file when the objects are legitimate, i.e. when it is determined that those problematic objects should be allowed to enter the server. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-23fsck: optionally ignore specific fsck issues completelyJohannes Schindelin
An fsck issue in a legacy repository might be so common that one would like not to bother the user with mentioning it at all. With this change, that is possible by setting the respective message type to "ignore". This change "abuses" the missingEmail=warn test to verify that "ignore" is also accepted and works correctly. And while at it, it makes sure that multiple options work, too (they are passed to unpack-objects or index-pack as a comma-separated list via the --strict=... command-line option). Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-23fsck (receive-pack): allow demoting errors to warningsJohannes Schindelin
For example, missing emails in commit and tag objects can be demoted to mere warnings with git config receive.fsck.missingemail=warn The value is actually a comma-separated list. In case that the same key is listed in multiple receive.fsck.<msg-id> lines in the config, the latter configuration wins (this can happen for example when both $HOME/.gitconfig and .git/config contain message type settings). As git receive-pack does not actually perform the checks, it hands off the setting to index-pack or unpack-objects in the form of an optional argument to the --strict option. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-23fsck: offer a function to demote fsck errors to warningsJohannes Schindelin
There are legacy repositories out there whose older commits and tags have issues that prevent pushing them when 'receive.fsckObjects' is set. One real-life example is a commit object that has been hand-crafted to list two authors. Often, it is not possible to fix those issues without disrupting the work with said repositories, yet it is still desirable to perform checks by setting `receive.fsckObjects = true`. This commit is the first step to allow demoting specific fsck issues to mere warnings. The `fsck_set_msg_types()` function added by this commit parses a list of settings in the form: missingemail=warn,badname=warn,... Unfortunately, the FSCK_WARN/FSCK_ERROR flag is only really heeded by git fsck so far, but other call paths (e.g. git index-pack --strict) error out *always* no matter what type was specified. Therefore, we need to take extra care to set all message types to FSCK_ERROR by default in those cases. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22fsck: introduce identifiers for fsck messagesJohannes Schindelin
Instead of specifying whether a message by the fsck machinery constitutes an error or a warning, let's specify an identifier relating to the concrete problem that was encountered. This is necessary for upcoming support to be able to demote certain errors to warnings. In the process, simplify the requirements on the calling code: instead of having to handle full-blown varargs in every callback, we now send a string buffer ready to be used by the callback. We could use a simple enum for the message IDs here, but we want to guarantee that the enum values are associated with the appropriate message types (i.e. error or warning?). Besides, we want to introduce a parser in the next commit that maps the string representation to the enum value, hence we use the slightly ugly preprocessor construct that is extensible for use with said parser. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22fsck: introduce fsck optionsJohannes Schindelin
Just like the diff machinery, we are about to introduce more settings, therefore it makes sense to carry them around as a (pointer to a) struct containing all of them. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-10fsck_object(): allow passing object data separately from the object itselfJohannes Schindelin
When fsck'ing an incoming pack, we need to fsck objects that cannot be read via read_sha1_file() because they are not local yet (and might even be rejected if transfer.fsckobjects is set to 'true'). For commits, there is a hack in place: we basically cache commit objects' buffers anyway, but the same is not true, say, for tag objects. By refactoring fsck_object() to take the object buffer and size as optional arguments -- optional, because we still fall back to the previous method to look at the cached commit objects if the caller passes NULL -- we prepare the machinery for the upcoming handling of tag objects. The assumption that such buffers are inherently NUL terminated is now wrong, of course, hence we pass the size of the buffer so that we can add a sanity check later, to prevent running past the end of the buffer. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-11-16Check the format of more printf-type functionsTarmigan Casebolt
We already have these checks in many printf-type functions that have prototypes which are in header files. Add these same checks to some more prototypes in header functions and to static functions in .c files. cc: Miklos Vajna <vmiklos@frugalware.org> Signed-off-by: Tarmigan Casebolt <tarmigan+git@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-04-23Fix typos / spelling in commentsMike Ralphson
Signed-off-by: Mike Ralphson <mike@abacus.co.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-26add common fsck error printing functionMartin Koegler
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-26builtin-fsck: move common object checking code to fsck.cMartin Koegler
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-26add generic, type aware object chain walkerMartin Koegler
The requirements are: * it may not crash on NULL pointers * a callback function is needed, as index-pack/unpack-objects need to do different things * the type information is needed to check the expected <-> real type and print better error messages Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>