Граф коммитов

22 Коммитов

Автор SHA1 Сообщение Дата
Jeff King 5afc4b1dc6 fsck: only provide oid/type in fsck_error callback
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>
2019-10-28 14:05:18 +09:00
Jeff King 733902905d fsck: use oids rather than objects for object_name API
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>
2019-10-28 14:05:18 +09:00
Jeff King a59cfb3230 fsck: unify object-name code
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>
2019-10-28 14:05:17 +09:00
Jeff King 23a173a761 fsck: require an actual buffer for non-blobs
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>
2019-10-28 14:05:17 +09:00
René Scharfe 3b41fb0cb2 fsck: use oidset instead of oid_array for skipList
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>
2018-09-12 15:17:46 -07:00
Elijah Newren ef3ca95475 Add missing includes and forward declarations
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>
2018-08-15 11:52:09 -07:00
Jeff King 159e7b080b fsck: detect gitmodules files
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>
2018-05-21 23:55:12 -04:00
brian m. carlson 910650d2f8 Rename sha1_array to oid_array
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>
2017-03-31 08:33:56 -07:00
Johannes Schindelin 1cd772cc41 fsck: give the error function a chance to see the fsck_options
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>
2016-07-18 11:35:00 -07:00
Johannes Schindelin 7b35efd734 fsck_walk(): optionally name objects on the go
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>
2016-07-18 11:35:00 -07:00
Johannes Schindelin cd94c6f91e fsck: git receive-pack: support excluding objects from fsck'ing
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>
2015-06-23 14:27:37 -07:00
Johannes Schindelin efaba7cc77 fsck: optionally ignore specific fsck issues completely
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>
2015-06-23 14:27:36 -07:00
Johannes Schindelin 5d477a334a fsck (receive-pack): allow demoting errors to warnings
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>
2015-06-23 14:27:34 -07:00
Johannes Schindelin 0282f4dced fsck: offer a function to demote fsck errors to warnings
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>
2015-06-23 14:26:46 -07:00
Johannes Schindelin c99ba492f1 fsck: introduce identifiers for fsck messages
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>
2015-06-22 10:24:27 -07:00
Johannes Schindelin 22410549fc fsck: introduce fsck options
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>
2015-06-22 10:23:32 -07:00
Johannes Schindelin 90a398bbd7 fsck_object(): allow passing object data separately from the object itself
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>
2014-09-10 13:54:21 -07:00
Tarmigan Casebolt 28bea9e534 Check the format of more printf-type functions
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>
2009-11-15 18:24:58 -08:00
Mike Ralphson 3ea3c215c0 Fix typos / spelling in comments
Signed-off-by: Mike Ralphson <mike@abacus.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-04-22 19:02:12 -07:00
Martin Koegler d6ffc8d784 add common fsck error printing function
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-25 23:57:35 -08:00
Martin Koegler ba002f3b28 builtin-fsck: move common object checking code to fsck.c
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-25 23:57:35 -08:00
Martin Koegler 355885d531 add generic, type aware object chain walker
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>
2008-02-25 23:57:34 -08:00