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228 Commits

Author SHA1 Message Date
Elijah Newren
baf889c2cd sparse-index.h: move declarations for sparse-index.c from cache.h
Note in particular that this reverses the decision made in 118a2e8bde
("cache: move ensure_full_index() to cache.h", 2021-04-01).

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21 13:39:53 -07:00
Derrick Stolee
cf9cd8b55c fsck: use local repository
In 0d30feef3c (fsck: create scaffolding for rev-index checks,
2023-04-17) and later 5a6072f631 (fsck: validate .rev file header,
2023-04-17), the check_pack_rev_indexes() method was created with a
'struct repository *r' parameter. However, this parameter was unused and
instead 'the_repository' was used in its place.

Fix this situation with the obvious replacement.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-02 08:48:23 -07:00
Derrick Stolee
756f1bcd29 fsck: verify checksums of all .bitmap files
If a filesystem-level corruption occurs in a .bitmap file, Git can react
poorly. This could take the form of a run-time error due to failing to
parse an EWAH bitmap or be more subtle such as returning the wrong set
of objects to a fetch or clone.

A natural first response to either of these kinds of errors is to run
'git fsck' to see if any files are corrupt. This currently ignores all
.bitmap files.

Add checks to 'git fsck' for all .bitmap files that are currently
associated with a multi-pack-index or pack file. Verify their checksums
using the hashfile API.

We iterate through all multi-pack-indexes and pack-files to be sure to
check all .bitmap files, not just the one that would be read by the
process. For example, a multi-pack-index bitmap overrules a pack-bitmap.
However, if the multi-pack-index is removed, the pack-bitmap may be
selected instead. Be thorough to include every file that could become
active in such a way. This includes checking files in alternates.

There is potential that we could extend this effort to check the
structure of the reachability bitmaps themselves, but it is very
expensive to do so. At minimum, it's as expensive as generating the
bitmaps in the first place, and that's assuming that we don't use the
trivial algorithm of verifying each bitmap individually. The trivial
algorithm will result in quadratic behavior (number of objects times
number of bitmapped commits) while the bitmap building operation
constructs a lattice of commits to build bitmaps incrementally and then
generate the final bitmaps from a subset of those commits.

If we were to extend 'git fsck' to check .bitmap file contents more
closely like this, then we would likely want to hide it behind an option
that signals the user is more willing to do expensive operations such as
this.

For testing, set up a repository with a pack-bitmap _and_ a
multi-pack-index bitmap. This requires some file movement to avoid
deleting the pack-bitmap during the repack that creates the
multi-pack-index bitmap. We can then verify that 'git fsck' is checking
all files, not just the "active" bitmap.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-02 08:48:22 -07:00
Junio C Hamano
a02675ad90 Merge branch 'ds/fsck-pack-revindex'
"git fsck" learned to validate the on-disk pack reverse index files.

* ds/fsck-pack-revindex:
  fsck: validate .rev file header
  fsck: check rev-index position values
  fsck: check rev-index checksums
  fsck: create scaffolding for rev-index checks
2023-04-27 16:00:59 -07:00
Derrick Stolee
5a6072f631 fsck: validate .rev file header
While parsing a .rev file, we check the header information to be sure it
makes sense. This happens before doing any additional validation such as
a checksum or value check. In order to differentiate between a bad
header and a non-existent file, we need to update the API for loading a
reverse index.

Make load_pack_revindex_from_disk() non-static and specify that a
positive value means "the file does not exist" while other errors during
parsing are negative values. Since an invalid header prevents setting up
the structures we would use for further validations, we can stop at that
point.

The place where we can distinguish between a missing file and a corrupt
file is inside load_revindex_from_disk(), which is used both by pack
rev-indexes and multi-pack-index rev-indexes. Some tests in t5326
demonstrate that it is critical to take some conditions to allow
positive error signals.

Add tests that check the three header values.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-17 14:39:05 -07:00
Derrick Stolee
0d30feef3c fsck: create scaffolding for rev-index checks
The 'fsck' builtin checks many of Git's on-disk data structures, but
does not currently validate the pack rev-index files (a .rev file to
pair with a .pack and .idx file).

Before doing a more-involved check process, create the scaffolding
within builtin/fsck.c to have a new error type and add that error type
when the API method verify_pack_revindex() returns an error. That method
does nothing currently, but we will add checks to it in later changes.

For now, check that 'git fsck' succeeds without any errors in the normal
case. Future checks will be paired with tests that corrupt the .rev file
appropriately.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-17 14:39:04 -07:00
Elijah Newren
87bed17907 object-file.h: move declarations for object-file.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11 08:52:10 -07:00
Elijah Newren
dabab1d6e6 object-name.h: move declarations for object-name.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11 08:52:09 -07:00
Junio C Hamano
6047b28eb7 Merge branch 'en/header-split-cleanup'
Split key function and data structure definitions out of cache.h to
new header files and adjust the users.

* en/header-split-cleanup:
  csum-file.h: remove unnecessary inclusion of cache.h
  write-or-die.h: move declarations for write-or-die.c functions from cache.h
  treewide: remove cache.h inclusion due to setup.h changes
  setup.h: move declarations for setup.c functions from cache.h
  treewide: remove cache.h inclusion due to environment.h changes
  environment.h: move declarations for environment.c functions from cache.h
  treewide: remove unnecessary includes of cache.h
  wrapper.h: move declarations for wrapper.c functions from cache.h
  path.h: move function declarations for path.c functions from cache.h
  cache.h: remove expand_user_path()
  abspath.h: move absolute path functions from cache.h
  environment: move comment_line_char from cache.h
  treewide: remove unnecessary cache.h inclusion from several sources
  treewide: remove unnecessary inclusion of gettext.h
  treewide: be explicit about dependence on gettext.h
  treewide: remove unnecessary cache.h inclusion from a few headers
2023-04-06 13:38:31 -07:00
Junio C Hamano
72871b198f Merge branch 'ab/remove-implicit-use-of-the-repository'
Code clean-up around the use of the_repository.

* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-06 13:38:30 -07:00
Junio C Hamano
e7dca80692 Merge branch 'ab/remove-implicit-use-of-the-repository' into en/header-split-cache-h
* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-04 08:25:52 -07:00
Ævar Arnfjörð Bjarmason
d850b7a545 cocci: apply the "cache.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"cache.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:36 -07:00
Elijah Newren
f394e093df treewide: be explicit about dependence on gettext.h
Dozens of files made use of gettext functions, without explicitly
including gettext.h.  This made it more difficult to find which files
could remove a dependence on cache.h.  Make C files explicitly include
gettext.h if they are using it.

However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:51 -07:00
Junio C Hamano
d0732a8120 Merge branch 'jk/unused-post-2.39-part2'
More work towards -Wunused.

* jk/unused-post-2.39-part2: (21 commits)
  help: mark unused parameter in git_unknown_cmd_config()
  run_processes_parallel: mark unused callback parameters
  userformat_want_item(): mark unused parameter
  for_each_commit_graft(): mark unused callback parameter
  rewrite_parents(): mark unused callback parameter
  fetch-pack: mark unused parameter in callback function
  notes: mark unused callback parameters
  prio-queue: mark unused parameters in comparison functions
  for_each_object: mark unused callback parameters
  list-objects: mark unused callback parameters
  mark unused parameters in signal handlers
  run-command: mark error routine parameters as unused
  mark "pointless" data pointers in callbacks
  ref-filter: mark unused callback parameters
  http-backend: mark unused parameters in virtual functions
  http-backend: mark argc/argv unused
  object-name: mark unused parameters in disambiguate callbacks
  serve: mark unused parameters in virtual functions
  serve: use repository pointer to get config
  ls-refs: drop config caching
  ...
2023-03-17 14:03:09 -07:00
Junio C Hamano
88cc8ed8bc Merge branch 'en/header-cleanup'
Code clean-up to clarify the rule that "git-compat-util.h" must be
the first to be included.

* en/header-cleanup:
  diff.h: remove unnecessary include of object.h
  Remove unnecessary includes of builtin.h
  treewide: replace cache.h with more direct headers, where possible
  replace-object.h: move read_replace_refs declaration from cache.h to here
  object-store.h: move struct object_info from cache.h
  dir.h: refactor to no longer need to include cache.h
  object.h: stop depending on cache.h; make cache.h depend on object.h
  ident.h: move ident-related declarations out of cache.h
  pretty.h: move has_non_ascii() declaration from commit.h
  cache.h: remove dependence on hex.h; make other files include it explicitly
  hex.h: move some hex-related declarations from cache.h
  hash.h: move some oid-related declarations from cache.h
  alloc.h: move ALLOC_GROW() functions from cache.h
  treewide: remove unnecessary cache.h includes in source files
  treewide: remove unnecessary cache.h includes
  treewide: remove unnecessary git-compat-util.h includes in headers
  treewide: ensure one of the appropriate headers is sourced first
2023-03-17 14:03:09 -07:00
Jeff King
8d3e7eac52 fsck: check even zero-entry index files
In fb64ca526a (fsck: check index files in all worktrees, 2023-02-24), we
swapped out a call to vanilla repo_read_index() for a series of
read_index_from() calls, one per worktree. The code for the latter was
copied from add_index_objects_to_pending(), which checks for a positive
return value from the index reading function, and we do the same here in
fsck now.

But this is probably the wrong thing. I had interpreted the check as
"don't operate on the index struct if there was an error". But in
reality, if there is an error then the index-reading code will simply
die (which admittedly is not great for fsck, but that is not a new
problem).

The return value here is actually the number of entries read. So it
makes sense for add_index_objects_to_pending() to ignore a zero-entry
index (there is nothing to add). But for fsck, we would still want to
check any extensions, etc (though presumably it is unlikely to have them
in an empty index, I don't think it's impossible).

So we should ignore the return value from read_index_from() entirely.
This matches the behavior before fb64ca526a, when we ignored the return
value from repo_read_index().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-27 07:36:36 -08:00
Jeff King
592ec63b38 fsck: mention file path for index errors
If we encounter an error in an index file, we may say something like:

  error: 1234abcd: invalid sha1 pointer in resolve-undo

But if you have multiple worktrees, each with its own index, it can be
very helpful to know which file had the problem. So let's pass that path
down through the various index-fsck functions and use it where
appropriate. After this patch you should get something like:

  error: 1234abcd: invalid sha1 pointer in resolve-undo of .git/worktrees/wt/index

That's a bit verbose, but since the point is that you shouldn't see this
normally, we're better to err on the side of more details.

I've also added the index filename to the name used by "fsck
--name-objects", which will show up if we find the object to be missing,
etc. This is bending the rules a little there, as the option claims to
write names that can be fed to rev-parse. But there is no revision
syntax to access the index of another worktree, so the best we can do is
make up something that a human will probably understand.

I did take care to retain the existing ":file" syntax for the current
worktree. So the uglier output should kick in only when it's actually
necessary. See the included tests for examples of both forms.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-24 09:32:23 -08:00
Jeff King
fb64ca526a fsck: check index files in all worktrees
We check the index file for the main worktree, but completely ignore the
index files in other worktrees. These should be checked, too, as they
are part of the repository state (and in particular, errors in those
index files may cause repo-wide operations like "git gc" to complain).

Reported-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-24 09:32:23 -08:00
Jeff King
8840069a37 fsck: factor out index fsck
The code to fsck an index operates directly on the_index. Let's move it
into its own function in preparation for handling the index files from
other worktrees.

Since we now have only a single reference to the_index, let's drop
our USE_THE_INDEX_VARIABLE definition and just use the_repository.index
directly. That's a minor cleanup, but also ensures that we didn't miss
any references when moving the code into fsck_index().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-24 09:30:58 -08:00
Jeff King
be252d3349 for_each_object: mark unused callback parameters
The for_each_{loose,packed}_object interface uses callback functions,
but not every callback needs all of the parameters. Mark the unused ones
to satisfy -Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-24 09:13:31 -08:00
Elijah Newren
cbeab74713 replace-object.h: move read_replace_refs declaration from cache.h to here
Adjust several files to be more explicit about their dependency on
replace-objects to accommodate this change.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:30 -08:00
Elijah Newren
41771fa435 cache.h: remove dependence on hex.h; make other files include it explicitly
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:29 -08:00
Ævar Arnfjörð Bjarmason
07047d6829 cocci: apply "pending" index-compatibility to some "builtin/*.c"
Apply "index-compatibility.pending.cocci" rule to "builtin/*", but
exclude those where we conflict with in-flight changes.

As a result some of them end up using only "the_index", so let's have
them use the more narrow "USE_THE_INDEX_VARIABLE" rather than
"USE_THE_INDEX_COMPATIBILITY_MACROS".

Manual changes not made by coccinelle, that were squashed in:

* Whitespace-wrap argument lists for repo_hold_locked_index(),
  repo_read_index_preload() and repo_refresh_and_write_index(), in cases
  where the line became too long after the transformation.
* Change "refresh_cache()" to "refresh_index()" in a comment in
  "builtin/update-index.c".
* For those whose call was followed by perror("<macro-name>"), change
  it to perror("<function-name>"), referring to the new function.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-21 12:06:15 +09:00
Ævar Arnfjörð Bjarmason
dc594180d9 cocci & cache.h: apply variable section of "pending" index-compatibility
Mostly apply the part of "index-compatibility.pending.cocci" that
renames the global variables like "active_nr", which are a shorthand
to referencing (in that case) a struct member as "the_index.cache_nr".

In doing so move more of "index-compatibility.pending.cocci" to
"index-compatibility.cocci".

In the case of "active_nr" we'd have a textual conflict with
"ab/various-leak-fixes" in "next"[1]. Let's exclude that specific case
while moving the rule over from "pending".

1. 407b94280f (commit: discard partial cache before (re-)reading it,
   2022-11-08)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-21 12:06:15 +09:00
Junio C Hamano
7b9b634ca5 Merge branch 'ab/doc-synopsis-and-cmd-usage'
The short-help text shown by "git cmd -h" and the synopsis text
shown at the beginning of "git help cmd" have been made more
consistent.

* ab/doc-synopsis-and-cmd-usage: (34 commits)
  tests: assert consistent whitespace in -h output
  tests: start asserting that *.txt SYNOPSIS matches -h output
  doc txt & -h consistency: make "worktree" consistent
  worktree: define subcommand -h in terms of command -h
  reflog doc: list real subcommands up-front
  doc txt & -h consistency: make "commit" consistent
  doc txt & -h consistency: make "diff-tree" consistent
  doc txt & -h consistency: use "[<label>...]" for "zero or more"
  doc txt & -h consistency: make "annotate" consistent
  doc txt & -h consistency: make "stash" consistent
  doc txt & -h consistency: add missing options
  doc txt & -h consistency: use "git foo" form, not "git-foo"
  doc txt & -h consistency: make "bundle" consistent
  doc txt & -h consistency: make "read-tree" consistent
  doc txt & -h consistency: make "rerere" consistent
  doc txt & -h consistency: add missing options and labels
  doc txt & -h consistency: make output order consistent
  doc txt & -h consistency: add or fix optional "--" syntax
  doc txt & -h consistency: fix mismatching labels
  doc SYNOPSIS & -h: use "-" to separate words in labels, not "_"
  ...
2022-10-28 11:26:54 -07:00
Ævar Arnfjörð Bjarmason
d9054a19ed doc txt & -h consistency: add missing options
Change those built-in commands that were attempting to exhaustively
list the options in the "-h" output to actually do so, and always
have *.txt documentation know about the exhaustive list of options.

Let's also fix the documentation and -h output for those built-in
commands where the *.txt and -h output was a mismatch of missing
options on both sides.

In the case of "interpret-trailers" fixing the missing options reveals
that the *.txt version was implicitly claiming that the command had
two operating modes, which a look at the -h version (and studying the
documentation) will show is not the case.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-13 09:32:57 -07:00
Junio C Hamano
fdbfac60fd Merge branch 'jk/fsck-on-diet'
"git fsck" failed to release contents of tree objects already used
from the memory, which has been fixed.

* jk/fsck-on-diet:
  parse_object_buffer(): respect save_commit_buffer
  fsck: turn off save_commit_buffer
  fsck: free tree buffers after walking unreachable objects
2022-10-10 10:08:39 -07:00
Jeff King
51b27747e5 parse_object_buffer(): respect save_commit_buffer
If the global variable "save_commit_buffer" is set to 0, then
parse_commit() will throw away the commit object data after parsing it,
rather than sticking it into a commit slab. This goes all the way back
to 60ab26de99 ([PATCH] Avoid wasting memory in git-rev-list,
2005-09-15).

But there's another code path which may similarly stash the buffer:
parse_object_buffer(). This is where we end up if we parse a commit via
parse_object(), and it's used directly in a few other code paths like
git-fsck.

The original goal of 60ab26de99 was avoiding extra memory usage for
rev-list. And there it's not all that important to catch parse_object().
We use that function only for looking at the tips of the traversal, and
the majority of the commits are parsed by following parent links, where
we use parse_commit() directly. So we were wasting some memory, but only
a small portion.

It's much easier to see the effect with fsck. Since we now turn off
save_commit_buffer by default there, we _should_ be able to drop the
freeing of the commit buffer in fsck_obj(). But if we do so (taking the
first hunk of this patch without the rest), then the peak heap of "git
fsck" in a clone of git.git goes from 136MB to 194MB. Teaching
parse_object_buffer() to respect save_commit_buffer brings that down to
134.5MB (it's hard to tell from massif's output, but I suspect the
savings comes from avoiding the overhead of the mostly-empty commit
slab).

Other programs should see a small improvement. Both "rev-list --all" and
"fsck --connectivity-only" improve by a few hundred kilobytes, as they'd
avoid loading the tip objects of their traversals.

Most importantly, no code should be hurt by doing this. Any program that
turns off save_commit_buffer is already making the assumption that any
commit it sees may need to have its object data loaded on demand, as it
doesn't know which ones were parsed by parse_commit() versus
parse_object(). Not to mention that anything parsed by the commit graph
may be in the same boat, even if save_commit_buffer was not disabled.

This should be the only spot that needs to be fixed. Grepping for
set_commit_buffer() shows that this and parse_commit() are the only
relevant calls.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-22 11:40:47 -07:00
Jeff King
069e445256 fsck: turn off save_commit_buffer
When parsing a commit, the default behavior is to stuff the original
buffer into a commit_slab (which takes ownership of it). But for a tool
like fsck, this isn't useful. While we may look at the buffer further as
part of fsck_commit(), we'll always do so through a separate pointer;
attaching the buffer to the slab doesn't help.

Worse, it means we have to remember to free the commit buffer in all
call paths. We do so in fsck_obj(), which covers a regular "git fsck".
But with "--connectivity-only", we forget to do so in both
traverse_one_object(), which covers reachable objects, and
mark_unreachable_referents(), which covers unreachable ones. As a
result, that mode ends up storing an uncompressed copy of every commit
on the heap at once.

We could teach the code paths for --connectivity-only to also free
commit buffers. But there's an even easier fix: we can just turn off the
save_commit_buffer flag, and then we won't attach them to the commits in
the first place.

This reduces the peak heap of running "git fsck --connectivity-only" in
a clone of linux.git from ~2GB to ~1GB. According to massif, the
remaining memory goes where you'd expect: the object structs themselves,
the obj_hash containing them, and the delta base cache.

Note that we'll leave the call to free commit buffers in fsck_obj() for
now; it's not quite redundant because of a related bug that we'll fix in
a subsequent commit.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-22 11:40:11 -07:00
Jeff King
fbce4fa9ae fsck: free tree buffers after walking unreachable objects
After calling fsck_walk(), a tree object struct may be left in the
parsed state, with the full tree contents available via tree->buffer.
It's the responsibility of the caller to free these when it's done with
the object to avoid having many trees allocated at once.

In a regular "git fsck", we hit fsck_walk() only from fsck_obj(), which
does call free_tree_buffer(). Likewise for "--connectivity-only", we see
most objects via traverse_one_object(), which makes a similar call.

The exception is in mark_unreachable_referents(). When using both
"--connectivity-only" and "--dangling" (the latter of which is the
default), we walk all of the unreachable objects, and there we forget to
free. Most cases would not notice this, because they don't have a lot of
unreachable objects, but you can make a pathological case like this:

  git clone --bare /path/to/linux.git repo.git
  cd repo.git
  rm packed-refs ;# now everything is unreachable!
  git fsck --connectivity-only

That ends up with peak heap usage ~18GB, which is (not coincidentally)
close to the size of all uncompressed trees in the repository. After
this patch, the peak heap is only ~2GB.

A few things to note:

  - it might seem like fsck_walk(), if it is parsing the trees, should
    be responsible for freeing them. But the situation is quite tricky.
    In the non-connectivity mode, after we call fsck_walk() we then
    proceed with fsck_object() which actually does the type-specific
    sanity checks on the object contents. We do pass our own separate
    buffer to fsck_object(), but there's a catch: our earlier call to
    parse_object_buffer() may have attached that buffer to the object
    struct! So by freeing it, we leave the rest of the code with a
    dangling pointer.

    Likewise, the call to fsck_walk() in index-pack is subtle. It
    attaches a buffer to the tree object that must not be freed! And
    so rather than calling free_tree_buffer(), it actually detaches it
    by setting tree->buffer to NULL.

    These cases would _probably_ be fixable by having fsck_walk() free
    the tree buffer only when it was the one who allocated it via
    parse_tree(). But that would still leave the callers responsible for
    freeing other cases, so they wouldn't be simplified. While the
    current semantics for fsck_walk() make it easy to accidentally leak
    in new callers, at least they are simple to explain, and it's not a
    function that's likely to get a lot of new call-sites.

    And in any case, it's probably sensible to fix the leak first with
    this simple patch, and try any more complicated refactoring
    separately.

  - a careful reader may notice that fsck_obj() also frees commit
    buffers, but neither the call in traverse_one_object() nor the one
    touched in this patch does so. And indeed, this is another problem
    for --connectivity-only (and accounts for most of the 2GB heap after
    this patch), but it's one we'll fix in a separate commit.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-22 11:30:06 -07:00
Ævar Arnfjörð Bjarmason
5cf88fd8b0 git-compat-util.h: use "UNUSED", not "UNUSED(var)"
As reported in [1] the "UNUSED(var)" macro introduced in
2174b8c75d (Merge branch 'jk/unused-annotation' into next,
2022-08-24) breaks coccinelle's parsing of our sources in files where
it occurs.

Let's instead partially go with the approach suggested in [2] of
making this not take an argument. As noted in [1] "coccinelle" will
ignore such tokens in argument lists that it doesn't know about, and
it's less of a surprise to syntax highlighters.

This undoes the "help us notice when a parameter marked as unused is
actually use" part of 9b24034754 (git-compat-util: add UNUSED macro,
2022-08-19), a subsequent commit will further tweak the macro to
implement a replacement for that functionality.

1. https://lore.kernel.org/git/220825.86ilmg4mil.gmgdl@evledraar.gmail.com/
2. https://lore.kernel.org/git/220819.868rnk54ju.gmgdl@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-01 10:49:48 -07:00
Jeff King
c006e9fa59 refs: mark unused reflog callback parameters
Functions used with for_each_reflog_ent() need to conform to a
particular interface, but not every function needs all of the
parameters. Mark the unused ones to make -Wunused-parameter happy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 12:18:54 -07:00
Jeff King
63e14ee2d6 refs: mark unused each_ref_fn parameters
Functions used with for_each_ref(), etc, need to conform to the
each_ref_fn interface. But most of them don't need every parameter;
let's annotate the unused ones to quiet -Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 12:18:54 -07:00
Junio C Hamano
e0ad13977a fsck: do not dereference NULL while checking resolve-undo data
When we found an invalid object recorded in the resolve-undo data,
we would have ended up dereferencing NULL while fsck.  Reporting the
problem and going on to the next object is the right thing to do
here.

Noticed by SZEDER Gábor.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-11 16:26:33 -07:00
Junio C Hamano
5a5ea141e7 revision: mark blobs needed for resolve-undo as reachable
The resolve-undo extension was added to the index in cfc5789a
(resolve-undo: record resolved conflicts in a new index extension
section, 2009-12-25).  This extension records the blob object names
and their modes of conflicted paths when the path gets resolved
(e.g. with "git add"), to allow "undoing" the resolution with
"checkout -m path".  These blob objects should be guarded from
garbage-collection while we have the resolve-undo information in the
index (otherwise unresolve operation may try to use a blob object
that has already been pruned away).

But the code called from mark_reachable_objects() for the index
forgets to do so.  Teach add_index_objects_to_pending() helper to
also add objects referred to by the resolve-undo extension.

Also make matching changes to "fsck", which has code that is fairly
similar to the reachability stuff, but have parallel implementations
for all these stuff, which may (or may not) someday want to be unified.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-09 16:45:07 -07:00
Ævar Arnfjörð Bjarmason
2b7098936c run-command API users: use strvec_pushl(), not argv construction
Change a pattern of hardcoding an "argv" array size, populating it and
assigning to the "argv" member of "struct child_process" to instead
use "strvec_pushl()" to add data to the "args" member.

This implements the same behavior as before in fewer lines of code,
and moves us further towards being able to remove the "argv" member in
a subsequent commit.

Since we've entirely removed the "argv" variable(s) we can be sure
that no potential logic errors of the type discussed in a preceding
commit are being introduced here, i.e. ones where the local "argv" was
being modified after the assignment to "struct child_process"'s
"argv".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-25 22:15:07 -08:00
Junio C Hamano
2c0fa66bc8 Merge branch 'ab/fsck-unexpected-type'
Regression fix.

* ab/fsck-unexpected-type:
  object-file: free(*contents) only in read_loose_object() caller
  object-file: fix SEGV on free() regression in v2.34.0-rc2
2021-11-12 15:29:25 -08:00
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>
2021-11-11 13:40:43 -08:00
Junio C Hamano
7afb458e91 Merge branch 'gc/use-repo-settings'
It is wrong to read some settings directly from the config
subsystem, as things like feature.experimental can affect their
default values.

* gc/use-repo-settings:
  gc: perform incremental repack when implictly enabled
  fsck: verify multi-pack-index when implictly enabled
  fsck: verify commit graph when implicitly enabled
2021-11-01 13:48:08 -07:00
Junio C Hamano
061a21d36d Merge branch 'ab/fsck-unexpected-type'
"git fsck" has been taught to report mismatch between expected and
actual types of an object better.

* ab/fsck-unexpected-type:
  fsck: report invalid object type-path combinations
  fsck: don't hard die on invalid object types
  object-file.c: stop dying in parse_loose_header()
  object-file.c: return ULHR_TOO_LONG on "header too long"
  object-file.c: use "enum" return type for unpack_loose_header()
  object-file.c: simplify unpack_loose_short_header()
  object-file.c: make parse_loose_header_extended() public
  object-file.c: return -1, not "status" from unpack_loose_header()
  object-file.c: don't set "typep" when returning non-zero
  cat-file tests: test for current --allow-unknown-type behavior
  cat-file tests: add corrupt loose object test
  cat-file tests: test for missing/bogus object with -t, -s and -p
  cat-file tests: move bogus_* variable declarations earlier
  fsck tests: test for garbage appended to a loose object
  fsck tests: test current hash/type mismatch behavior
  fsck tests: refactor one test to use a sub-repo
  fsck tests: add test for fsck-ing an unknown type
2021-10-25 16:06:56 -07:00
Glen Choo
dc5570872f fsck: verify multi-pack-index when implictly enabled
Like the previous commit, change fsck to check the
"core_multi_pack_index" variable set in "repo-settings.c" instead of
reading the "core.multiPackIndex" config variable. This fixes a bug
where we wouldn't verify midx if the config key was missing. This bug
was introduced in 18e449f86b (midx: enable core.multiPackIndex by
default, 2020-09-25) where core.multiPackIndex was turned on by default.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-15 14:30:08 -07:00
Glen Choo
f30e4d854b fsck: verify commit graph when implicitly enabled
Change fsck to check the "core_commit_graph" variable set in
"repo-settings.c" instead of reading the "core.commitGraph" variable.
This fixes a bug where we wouldn't verify the commit-graph if the
config key was missing. This bug was introduced in
31b1de6a09 (commit-graph: turn on commit-graph by default, 2019-08-13),
where core.commitGraph was turned on by default.

Add tests to "t5318-commit-graph.sh" to verify that fsck checks the
commit-graph as expected for the 3 values of core.commitGraph. Also,
disable GIT_TEST_COMMIT_GRAPH in t/t0410-partial-clone.sh because some
test cases use fsck in ways that assume that commit-graph checking is
disabled.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-15 14:30:07 -07:00
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>
2021-10-01 15:06:01 -07:00
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>
2021-10-01 15:06:01 -07:00
Junio C Hamano
ed125c4f07 Merge branch 'ab/fsck-api-cleanup'
Last minute compilation fix.

* ab/fsck-api-cleanup:
  builtin/fsck.c: don't conflate "int" and "enum" in callback
2021-06-02 07:34:27 +09:00
Ævar Arnfjörð Bjarmason
28abf260a5 builtin/fsck.c: don't conflate "int" and "enum" in callback
Fix a warning on AIX's xlc compiler that's been emitted since my
a1aad71601 (fsck.h: use "enum object_type" instead of "int",
2021-03-28):

    "builtin/fsck.c", line 805.32: 1506-068 (W) Operation between
    types "int(*)(struct object*,enum object_type,void*,struct
    fsck_options*)" and "int(*)(struct object*,int,void*,struct
    fsck_options*)" is not allowed.

I.e. it complains about us assigning a function with a prototype "int"
where we're expecting "enum object_type".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-02 05:59:15 +09:00
Junio C Hamano
8e97852919 Merge branch 'ds/sparse-index-protections'
Builds on top of the sparse-index infrastructure to mark operations
that are not ready to mark with the sparse index, causing them to
fall back on fully-populated index that they always have worked with.

* ds/sparse-index-protections: (47 commits)
  name-hash: use expand_to_path()
  sparse-index: expand_to_path()
  name-hash: don't add directories to name_hash
  revision: ensure full index
  resolve-undo: ensure full index
  read-cache: ensure full index
  pathspec: ensure full index
  merge-recursive: ensure full index
  entry: ensure full index
  dir: ensure full index
  update-index: ensure full index
  stash: ensure full index
  rm: ensure full index
  merge-index: ensure full index
  ls-files: ensure full index
  grep: ensure full index
  fsck: ensure full index
  difftool: ensure full index
  commit: ensure full index
  checkout: ensure full index
  ...
2021-04-30 13:50:26 +09:00
Derrick Stolee
2227ea175f fsck: ensure full index
When verifying all blobs reachable from the index, ensure that a sparse
index has been expanded to a full one to avoid missing some blobs.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-14 13:47:11 -07:00
Jeff King
45a187cc34 lookup_unknown_object(): take a repository argument
All of the other lookup_foo() functions take a repository argument, but
lookup_unknown_object() was never converted, and it uses the_repository
internally. Let's fix that.

We could leave a wrapper that uses the_repository, but there aren't that
many calls, so we'll just convert them all. I looked briefly at each
site to see if we had a repository struct (besides the_repository) we
could pass, but none of them do (so this conversion to pass
the_repository is a pure noop in each case, though it does take us one
step closer to eventually getting rid of the_repository).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-13 13:18:46 -07:00
Ævar Arnfjörð Bjarmason
394d5d31b0 fsck.c: pass along the fsck_msg_id in the fsck_error callback
Change the fsck_error callback to also pass along the
fsck_msg_id. Before this change the only way to get the message id was
to parse it back out of the "message".

Let's pass it down explicitly for the benefit of callers that might
want to use it, as discussed in [1].

Passing the msg_type is now redundant, as you can always get it back
from the msg_id, but I'm not changing that convention. It's really
common to need the msg_type, and the report() function itself (which
calls "fsck_error") needs to call fsck_msg_type() to discover
it. Let's not needlessly re-do that work in the user callback.

1. https://lore.kernel.org/git/87blcja2ha.fsf@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-28 19:03:10 -07:00