This allows us to replace includes of cache.h with includes of the much
smaller alloc.h in many places. It does mean that we also need to add
includes of alloc.h in a number of C files.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In cmd_repack() when we hit an error, replace "return ret" with "goto
cleanup" to ensure we free the necessary data structures.
Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various leak fixes.
* ab/various-leak-fixes:
built-ins: use free() not UNLEAK() if trivial, rm dead code
revert: fix parse_options_concat() leak
cherry-pick: free "struct replay_opts" members
rebase: don't leak on "--abort"
connected.c: free the "struct packed_git"
sequencer.c: fix "opts->strategy" leak in read_strategy_opts()
ls-files: fix a --with-tree memory leak
revision API: call graph_clear() in release_revisions()
unpack-file: fix ancient leak in create_temp_file()
built-ins & libs & helpers: add/move destructors, fix leaks
dir.c: free "ident" and "exclude_per_dir" in "struct untracked_cache"
read-cache.c: clear and free "sparse_checkout_patterns"
commit: discard partial cache before (re-)reading it
{reset,merge}: call discard_index() before returning
tests: mark tests as passing with SANITIZE=leak
Fix various leaks in built-ins, libraries and a test helper here we
were missing a call to strbuf_release(), string_list_clear() etc, or
were calling them after a potential "return".
Comments on individual changes:
- builtin/checkout.c: Fix a memory leak that was introduced in [1]. A
sibling leak introduced in [2] was recently fixed in [3]. As with [3]
we should be using the wt_status_state_free_buffers() API introduced
in [4].
- builtin/repack.c: Fix a leak that's been here since this use of
"strbuf_release()" was added in a1bbc6c017 (repack: rewrite the shell
script in C, 2013-09-15). We don't use the variable for anything
except this loop, so we can instead free it right afterwards.
- builtin/rev-parse: Fix a leak that's been here since this code was
added in 21d4783538 (Add a parseopt mode to git-rev-parse to bring
parse-options to shell scripts., 2007-11-04).
- builtin/stash.c: Fix a couple of leaks that have been here since
this code was added in d4788af875 (stash: convert create to builtin,
2019-02-25), we strbuf_release()'d only some of the "struct strbuf" we
allocated earlier in the function, let's release all of them.
- ref-filter.c: Fix a leak in 482c119186 (gpg-interface: improve
interface for parsing tags, 2021-02-11), we don't use the "payload"
variable that we ask parse_signature() to populate for us, so let's
free it.
- t/helper/test-fake-ssh.c: Fix a leak that's been here since this
code was added in 3064d5a38c (mingw: fix t5601-clone.sh,
2016-01-27). Let's free the "struct strbuf" as soon as we don't need
it anymore.
1. c45f0f525d (switch: reject if some operation is in progress,
2019-03-29)
2. 2708ce62d2 (branch: sort detached HEAD based on a flag,
2021-01-07)
3. abcac2e19f (ref-filter.c: fix a leak in get_head_description,
2022-09-25)
4. 962dd7ebc3 (wt-status: introduce wt_status_state_free_buffers(),
2020-09-27).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
"git repack" learns to send cruft objects out of the way into
packfiles outside the repository.
* tb/repack-expire-to:
builtin/repack.c: implement `--expire-to` for storing pruned objects
builtin/repack.c: write cruft packs to arbitrary locations
builtin/repack.c: pass "cruft_expiration" to `write_cruft_pack`
builtin/repack.c: pass "out" to `prepare_pack_objects`
The way "git repack" creared temporary files when it received a
signal was prone to deadlocking, which has been corrected.
* jk/repack-tempfile-cleanup:
t7700: annotate cruft-pack failure with ok=sigpipe
repack: drop remove_temporary_files()
repack: use tempfiles for signal cleanup
repack: expand error message for missing pack files
repack: populate extension bits incrementally
repack: convert "names" util bitfield to array
When creating a multi-pack bitmap, remove per-pack bitmap files
unconditionally as they will never be consulted.
* tb/remove-unused-pack-bitmap:
builtin/repack.c: remove redundant pack-based bitmaps
When pruning objects with `--cruft`, `git repack` offers some
flexibility when selecting the set of which objects are pruned via the
`--cruft-expiration` option.
This is useful for expiring objects which are older than the grace
period, making races where to-be-pruned objects become reachable and
then ancestors of freshly pushed objects, leaving the repository in a
corrupt state after pruning substantially less likely [1].
But in practice, such races are impossible to avoid entirely, no matter
how long the grace period is. To prevent this race, it is often
advisable to temporarily put a repository into a read-only state. But in
practice, this is not always practical, and so some middle ground would
be nice.
This patch introduces a new option, `--expire-to`, which teaches `git
repack` to write an additional cruft pack containing just the objects
which were pruned from the repository. The caller can specify a
directory outside of the current repository as the destination for this
second cruft pack.
This makes it possible to prune objects from a repository, while still
holding onto a supplemental copy of them outside of the original
repository. Having this copy on-disk makes it substantially easier to
recover objects when the aforementioned race is encountered.
`--expire-to` is implemented in a somewhat convoluted manner, which is
to take advantage of the fact that the first time `write_cruft_pack()`
is called, it adds the name of the cruft pack to the `names` string
list. That means the second time we call `write_cruft_pack()`, objects
in the previously-written cruft pack will be excluded.
As long as the caller ensures that no objects are expired during the
second pass, this is sufficient to generate a cruft pack containing all
objects which don't appear in any of the new packs written by `git
repack`, including the cruft pack. In other words, all of the objects
which are about to be pruned from the repository.
It is important to note that the destination in `--expire-to` does not
necessarily need to be a Git repository (though it can be) Notably, the
expired packs do not contain all ancestors of expired objects. So if the
source repository contains something like:
<unreachable>
/
C1 --- C2
\
refs/heads/master
where C2 is unreachable, but has a parent (C1) which is reachable, and
C2 would be pruned, then the expiry pack will contain only C2, not C1.
[1]: https://lore.kernel.org/git/20190319001829.GL29661@sigill.intra.peff.net/
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the following commit, a new write_cruft_pack() caller will be added
which wants to write a cruft pack to an arbitrary location. Prepare for
this by adding a parameter which controls the destination of the cruft
pack.
For now, provide "packtmp" so that this commit does not change any
behavior.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`builtin/repack.c`'s `write_cruft_pack()` is used to generate the cruft
pack when `--cruft` is supplied. It uses a static variable
"cruft_expiration" which is filled in by option parsing.
A future patch will add an `--expire-to` option which allows `git
repack` to write a cruft pack containing the pruned objects out to a
separate repository. In order to implement this functionality, some
callers will have to pass a value for `cruft_expiration` different than
the one filled out by option parsing.
Prepare for this by teaching `write_cruft_pack` to take a
"cruft_expiration" parameter, instead of reading a single static
variable.
The (sole) existing caller of `write_cruft_pack()` will pass the value
for "cruft_expiration" filled in by option parsing, retaining existing
behavior. This means that we can make the variable local to
`cmd_repack()`, and eliminate the static declaration.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`builtin/repack.c`'s `prepare_pack_objects()` is used to prepare a set
of arguments to a `pack-objects` process which will generate a desired
pack.
A future patch will add an `--expire-to` option which allows `git
repack` to write a cruft pack containing the pruned objects out to a
separate repository. Prepare for this by teaching that function to write
packs to an arbitrary location specified by the caller.
All existing callers of `prepare_pack_objects()` will pass `packtmp` for
`out`, retaining the existing behavior.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After we've successfully finished the repack, we call
remove_temporary_files(), which looks for and removes any files matching
".tmp-$$-pack-*", where $$ is the pid of the current process. But this
is pointless. If we make it this far in the process, we've already
renamed these tempfiles into place, and there is nothing left to delete.
Nor is there a point in trying to call it to clean up when we _aren't_
successful. It's not safe for using in a signal handler, and the
previous commit already handed that job over to the tempfile API.
It might seem like it would be useful to clean up stray .tmp files left
by other invocations of git-repack. But it won't clean those files; it
only matches ones with its pid, and leaves the rest. Fortunately, those
are cleaned up naturally by successive calls to git-repack; we'll
consider .tmp-*.pack the same as normal packfiles, so "repack -ad", etc,
will roll up their contents and eventually delete them.
The one case that could matter is if pack-objects generates an extension
we don't know about, like ".tmp-pack-$$-$hash.some-new-ext". The current
code will quietly delete such a file, while after this patch we'd leave
it in place. In practice this doesn't happen, and would be indicative of
a bug. Leaving the file as cruft is arguably a better behavior, as it
means somebody is more likely to eventually notice and fix the bug. If
we really wanted to be paranoid, we could scan for and warn about such
files, but that seems like overkill.
There's nothing to test with regard to the removal of this function. It
was doing nothing, so the behavior should be the same. However, we can
verify (and protect) our assumption that "repack -ad" will eventually
remove stray files by adding a test for that.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When git-repack exits due to a signal, it tries to clean up by calling
its remove_temporary_files() function, which walks through the packs dir
looking for ".tmp-$$-pack-*" files to delete (where "$$" is the pid of
the current process).
The biggest problem here is that remove_temporary_files() is not safe to
call in a signal handler. It uses opendir(), which isn't on the POSIX
async-signal-safe list. The details will be platform-specific, but a
likely issue is that it needs to allocate memory; if we receive a signal
while inside malloc(), etc, we'll conflict on the allocator lock and
deadlock with ourselves.
We can fix this by just cleaning up the files directly, without walking
the directory. We already know the complete list of .tmp-* files that
were generated, because we recorded them via populate_pack_exts(). When
we find files there, we can use register_tempfile() to record the
filenames. If we receive a signal, then the tempfile API will clean them
up for us, and it's async-safe and pretty battle-tested.
Note that this is slightly racier than the existing scheme. We don't
record the filenames until pack-objects tells us the hash over stdout.
So during the period between it generating the file and reporting the
hash, we'd fail to clean up. However, that period is very small. During
most of the pack generation process pack-objects is using its own
internal tempfiles. It's only at the very end that it moves them into
the names git-repack expects, and then it immediately reports the name
to us. Given that cleanup like this is best effort (after all, we may
get SIGKILL), this level of race is acceptable.
When we register the tempfiles, we'll record them locally and use the
result to call rename_tempfile(), rather than renaming by hand. This
isn't strictly necessary, as once we've renamed the files they're gone,
and the tempfile API's cleanup unlink() would simply become a pointless
noop. But managing the lifetimes of the tempfile objects is the cleanest
thing to do, and the tempfile pointers naturally fill the same role as
the old booleans.
This patch also fixes another small problem. We only hook signals, and
don't set up an atexit handler. So if we see an error that causes us to
die(), we'll leave the .tmp-* files in place. But since the tempfile API
handles this for us, this is now fixed for free. The new test covers
this by stimulating a failure of pack-objects when generating a cruft
pack. Before this patch, the .tmp-* file for the main pack would have
been left, but now we correctly clean it up.
Two small subtleties on the implementation:
- in the renaming loop, we can stop re-constructing fname_old; we only
use it when we have a tempfile to rename, so we can just ask the
tempfile for its path (which, barring bugs, should be identical)
- when renaming fails, our error message mentions fname_old. But since
a failed rename_tempfile() invalidates the tempfile struct, we'll
lose access to that string. Instead, let's mention the destination
filename, which is what most other callers do.
Reported-by: Jan Pokorný <poki@fnusa.cz>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If pack-objects tells us it generated pack $hash, we expect to find
.tmp-$$-pack-$hash.pack, .idx, .rev, and so on. Some of these files are
optional, but others are not. For the required ones, we'll bail with an
error if any of them is missing.
The error message is just "missing required file", which is a bit vague.
We should be more clear that it is not the user's fault, but rather that
the sub-pgoram we called is not operating as expected. In practice,
nobody should ever see this message, as it would generally only be
caused by a bug in Git.
It probably doesn't make sense to convert this to a BUG(), though, as
there are other (unlikely) possibilities, such as somebody else racily
deleting the files, filesystem errors causing stat() to fail, and so on.
A nice side effect here is that we stop relying on fname_old in this
code path, which will let us deal with it only in the first part of the
conditional.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After generating the main pack and then any additional cruft packs, we
iterate over the "names" list (which contains hashes of packs generated
by pack-objects), and call populate_pack_exts() for each.
There's one small problem with this. In repack_promisor_objects(), we
may add entries to "names" and call populate_pack_exts() for them.
Calling it again is mostly just wasteful, as we'll stat() the filename
with each possible extension, get the same result, and just overwrite
our bits.
So we could drop the call there, and leave the final loop to populate
all of the bits. But instead, this patch does the reverse: drops the
final loop, and teaches the other two sites to populate the bits as they
add entries.
This makes the code easier to reason about, as you never have to worry
about when the util field is valid; it is always valid for each entry.
It also serves my ulterior purpose: recording the generated filenames as
soon as possible will make it easier for a future patch to use them for
cleaning up from a failed operation.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We keep a string_list "names" containing the hashes of packs generated
on our behalf by pack-objects. The util field of each item is treated as
a bitfield that tells us which extensions (.pack, .idx, .rev, etc) are
present for each name.
Let's switch this to allocating a real array. That will give us room in
a future patch to store more data than just a single bit per extension.
And it makes the code a little easier to read, as we avoid casting back
and forth between uintptr_t and a void pointer.
Since the only thing we're storing is an array, we could just allocate
it directly. But instead I've put it into a named struct here. That
further increases readability around the casts, and in particular helps
differentiate us from other string_lists in the same file which use
their util field differently. E.g., the existing_*_packs lists still do
bit-twiddling, but their bits have different meaning than the ones in
"names". This makes it hard to grep around the code to see how the util
fields are used; now you can look for "generated_pack_data".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`git repack` supports a `--pack-kept-objects` flag which more or less
translates to whether or not we pass `--honor-pack-keep` down to `git
pack-objects` when assembling a new pack.
This behavior has existed since ee34a2bead (repack: add
`repack.packKeptObjects` config var, 2014-03-03). In that commit, the
documentation was extended to say:
[...] Note that we still do not delete `.keep` packs after
`pack-objects` finishes.
Unfortunately, this is not the case when `--pack-kept-objects` is
combined with a `--geometric` repack. When doing a geometric repack, we
include `.keep` packs when enumerating available packs only when
`pack_kept_objects` is set.
So this all works fine when `--no-pack-kept-objects` (or similar) is
given. Kept packs are excluded from the geometric roll-up, so when we go
to delete redundant packs (with `-d`), no `.keep` packs appear "below
the split" in our geometric progression.
But when `--pack-kept-objects` is given, things can go awry. Namely,
when a kept pack is included in the list of packs tracked by the
`pack_geometry` struct *and* part of the pack roll-up, we will delete
the `.keep` pack when we shouldn't.
Note that this *doesn't* result in object corruption, since the `.keep`
pack's objects are still present in the new pack. But the `.keep` pack
itself is removed, which violates our promise from back in ee34a2bead.
But there's more. Because `repack` computes the geometric roll-up
independently from selecting which packs belong in a MIDX (with
`--write-midx`), this can lead to odd behavior. Consider when a `.keep`
pack appears below the geometric split (ie., its objects will be part of
the new pack we generate).
We'll write a MIDX containing the new pack along with the existing
`.keep` pack. But because the `.keep` pack appears below the geometric
split line, we'll (incorrectly) try to remove it. While this doesn't
corrupt the repository, it does cause us to remove the MIDX we just
wrote, since removing that pack would invalidate the new MIDX.
Funny enough, this behavior became far less noticeable after e4d0c11c04
(repack: respect kept objects with '--write-midx -b', 2021-12-20), which
made `pack_kept_objects` be enabled by default only when we were writing
a non-MIDX bitmap.
But e4d0c11c04 didn't resolve this bug, it just made it harder to notice
unless callers explicitly passed `--pack-kept-objects`.
The solution is to avoid trying to remove `.keep` packs during
`--geometric` repacks, even when they appear below the geometric split
line, which is the approach this patch implements.
Co-authored-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we write a MIDX bitmap after repacking, it is possible that the
repository would be left in a state with both pack- and multi-pack
reachability bitmaps.
This can occur, for instance, if a pack that was kept (either by having
a .keep file, or during a geometric repack in which it is not rolled up)
has a bitmap file, and the repack wrote a multi-pack index and bitmap.
When loading a reachability bitmap for the repository, the multi-pack
one is always preferred, so the pack-based one is redundant. Let's
remove it unconditionally, even if '-d' isn't passed, since there is no
practical reason to keep both around. The patch below does just that.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
Generalize the newly added "unused.cocci" rule to find more than just
"struct strbuf", let's have it find the same unused patterns for
"struct string_list", as well as other code that uses
similar-looking *_{release,clear,free}() and {release,clear,free}_*()
functions.
We're intentionally loose in accepting e.g. a "strbuf_init(&sb)"
followed by a "string_list_clear(&sb, 0)". It's assumed that the
compiler will catch any such invalid code, i.e. that our
constructors/destructors don't take a "void *".
See [1] for example of code that would be covered by the
"get_worktrees()" part of this rule. We'd still need work that the
series is based on (we were passing "worktrees" to a function), but
could now do the change in [1] automatically.
1. https://lore.kernel.org/git/Yq6eJFUPPTv%2Fzc0o@coredump.intra.peff.net/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some config variables are combinations of multiple words, and we
typically write them in camelCase forms in manpage and translatable
strings. It's not easy to find mismatches for these camelCase config
variables during code reviews, but occasionally they are identified
during localization translations.
To check for mismatched config variables, I introduced a new feature
in the helper program for localization[^1]. The following mismatched
config variables have been identified by running the helper program,
such as "git-po-helper check-pot".
Lowercase in manpage should use camelCase:
* Documentation/config/http.txt: http.pinnedpubkey
Lowercase in translable strings should use camelCase:
* builtin/fast-import.c: pack.indexversion
* builtin/gc.c: gc.logexpiry
* builtin/index-pack.c: pack.indexversion
* builtin/pack-objects.c: pack.indexversion
* builtin/repack.c: pack.writebitmaps
* commit.c: i18n.commitencoding
* gpg-interface.c: user.signingkey
* http.c: http.postbuffer
* submodule-config.c: submodule.fetchjobs
Mismatched camelCases, choose the former:
* Documentation/config/transfer.txt: transfer.credentialsInUrl
remote.c: transfer.credentialsInURL
[^1]: https://github.com/git-l10n/git-po-helper
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A mechanism to pack unreachable objects into a "cruft pack",
instead of ejecting them into loose form to be reclaimed later, has
been introduced.
* tb/cruft-packs:
sha1-file.c: don't freshen cruft packs
builtin/gc.c: conditionally avoid pruning objects via loose
builtin/repack.c: add cruft packs to MIDX during geometric repack
builtin/repack.c: use named flags for existing_packs
builtin/repack.c: allow configuring cruft pack generation
builtin/repack.c: support generating a cruft pack
builtin/pack-objects.c: --cruft with expiration
reachable: report precise timestamps from objects in cruft packs
reachable: add options to add_unseen_recent_objects_to_traversal
builtin/pack-objects.c: --cruft without expiration
builtin/pack-objects.c: return from create_object_entry()
t/helper: add 'pack-mtimes' test-tool
pack-mtimes: support writing pack .mtimes files
chunk-format.h: extract oid_version()
pack-write: pass 'struct packing_data' to 'stage_tmp_packfiles'
pack-mtimes: support reading .mtimes files
Documentation/technical: add cruft-packs.txt
When using cruft packs, the following race can occur when a geometric
repack that writes a MIDX bitmap takes place afterwords:
- First, create an unreachable object and do an all-into-one cruft
repack which stores that object in the repository's cruft pack.
- Then make that object reachable.
- Finally, do a geometric repack and write a MIDX bitmap.
Assuming that we are sufficiently unlucky as to select a commit from the
MIDX which reaches that object for bitmapping, then the `git
multi-pack-index` process will complain that that object is missing.
The reason is because we don't include cruft packs in the MIDX when
doing a geometric repack. Since the "make that object reachable" doesn't
necessarily mean that we'll create a new copy of that object in one of
the packs that will get rolled up as part of a geometric repack, it's
possible that the MIDX won't see any copies of that now-reachable
object.
Of course, it's desirable to avoid including cruft packs in the MIDX
because it causes the MIDX to store a bunch of objects which are likely
to get thrown away. But excluding that pack does open us up to the above
race.
This patch demonstrates the bug, and resolves it by including cruft
packs in the MIDX even when doing a geometric repack.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use the `util` pointer for items in the `existing_packs` string list
to indicate which packs are going to be deleted. Since that has so far
been the only use of that `util` pointer, we just set it to 0 or 1.
But we're going to add an additional state to this field in the next
patch, so prepare for that by adding a #define for the first bit so we
can more expressively inspect the flags state.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In servers which set the pack.window configuration to a large value, we
can wind up spending quite a lot of time finding new bases when breaking
delta chains between reachable and unreachable objects while generating
a cruft pack.
Introduce a handful of `repack.cruft*` configuration variables to
control the parameters used by pack-objects when generating a cruft
pack.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Expose a way to split the contents of a repository into a main and cruft
pack when doing an all-into-one repack with `git repack --cruft -d`, and
a complementary configuration variable.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To store the individual mtimes of objects in a cruft pack, introduce a
new `.mtimes` format that can optionally accompany a single pack in the
repository.
The format is defined in Documentation/technical/pack-format.txt, and
stores a 4-byte network order timestamp for each object in name (index)
order.
This patch prepares for cruft packs by defining the `.mtimes` format,
and introducing a basic API that callers can use to read out individual
mtimes.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous patch demonstrates a scenario where the list of packs
written by `pack-objects` (and stored in the `names` string_list) is
out-of-order, and can thus cause us to delete packs we shouldn't.
This patch resolves that bug by ensuring that `names` is sorted in all
cases, not just when
delete_redundant && pack_everything & ALL_INTO_ONE
is true.
Because we did sort `names` in that case (which, prior to `--geometric`
repacks, was the only time we would actually delete packs, this is only
a bug for `--geometric` repacks.
It would be sufficient to only sort `names` when `delete_redundant` is
set to a non-zero value. But sorting a small list of strings is cheap,
and it is defensive against future calls to `string_list_has_string()`
on this list.
Co-discovered-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update 'repack' to ignore packs named on the command line with the
'--keep-pack' option. Specifically, modify 'init_pack_geometry()' to treat
command line-kept packs the same way it treats packs with an on-disk '.keep'
file (that is, skip the pack and do not include it in the 'geometry'
structure).
Without this handling, a '--keep-pack' pack would be included in the
'geometry' structure. If the pack is *before* the geometry split line (with
at least one other pack and/or loose objects present), 'repack' assumes the
pack's contents are "rolled up" into another pack via 'pack-objects'.
However, because the internally-invoked 'pack-objects' properly excludes
'--keep-pack' objects, any new pack it creates will not contain the kept
objects. Finally, 'repack' deletes the '--keep-pack' as "redundant" (since
it assumes 'pack-objects' created a new pack with its contents), resulting
in possible object loss and repository corruption.
Add a test ensuring that '--keep-pack' packs are now appropriately handled.
Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By default, git-repack(1) will update server info that is required by
the dumb HTTP transport. This can be skipped by passing the `-n` flag,
but what we're noticably missing is a config option to permanently
disable updating this information.
Add a new option "repack.updateServerInfo" which can be used to disable
the logic. Most hosting providers have turned off the dumb HTTP protocol
anyway, and on the client-side it woudln't typically be useful either.
Giving a persistent way to disable this feature thus makes quite some
sense to avoid wasting compute cycles and storage.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By default, git-repack(1) runs `update_server_info()` to generate info
required for the dumb HTTP protocol. This can be disabled via the `-n`
flag, which then sets the `no_update_server_info` flag. Further down the
code this leads to some double-negation logic, which is about to become
more confusing as we're about to add a new config which allows the user
to permanently disable generation of the info.
Refactor the code to avoid the double-negation and add some tests which
verify that the flag continues to work as expected.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar message templates have been consolidated so that
translators need to work on fewer number of messages.
* ja/i18n-similar-messages:
i18n: turn even more messages into "cannot be used together" ones
i18n: ref-filter: factorize "%(foo) atom used without %(bar) atom"
i18n: factorize "--foo outside a repository"
i18n: refactor "unrecognized %(foo) argument" strings
i18n: factorize "no directory given for --foo"
i18n: factorize "--foo requires --bar" and the like
i18n: tag.c factorize i18n strings
i18n: standardize "cannot open" and "cannot read"
i18n: turn "options are incompatible" into "cannot be used together"
i18n: refactor "%s, %s and %s are mutually exclusive"
i18n: refactor "foo and bar are mutually exclusive"
While testing some ideas in 'git repack', I ran it with '--quiet' and
discovered that some progress output was still shown. Specifically, the
output for writing the multi-pack-index showed the progress.
The 'show_progress' variable in cmd_repack() is initialized with
isatty(2) and is not modified at all by the '--quiet' flag. The
'--quiet' flag modifies the po_args.quiet option which is translated
into a '--quiet' flag for the 'git pack-objects' child process. However,
'show_progress' is used to directly send progress information to the
multi-pack-index writing logic which does not use a child process.
The fix here is to modify 'show_progress' to be false if po_opts.quiet
is true, and isatty(2) otherwise. This new expectation simplifies a
later condition that checks both.
Update the documentation to make it clear that '-q' will disable all
progress in addition to ensuring the 'git pack-objects' child process
will receive the flag.
Use 'test_terminal' to check that this works to get around the isatty(2)
check.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Historically, we needed a single packfile in order to have reachability
bitmaps. This introduced logic that when 'git repack' had a '-b' option
that we should stop sending the '--honor-pack-keep' option to the 'git
pack-objects' child process, ensuring that we create a packfile
containing all reachable objects.
In the world of multi-pack-index bitmaps, we no longer need to repack
all objects into a single pack to have valid bitmaps. Thus, we should
continue sending the '--honor-pack-keep' flag to 'git pack-objects'.
The fix is very simple: only disable the flag when writing bitmaps but
also _not_ writing the multi-pack-index.
This opens the door to new repacking strategies that might want to keep
some historical set of objects in a stable pack-file while only
repacking more recent objects.
To test, create a new 'test_subcommand_inexact' helper that is more
flexible than 'test_subcommand'. This allows us to look for the
--honor-pack-keep flag without over-indexing on the exact set of
arguments.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On platforms where ulong is shorter than size_t, code paths that
shifted 1 or 1U to the left lacked the necessary cast to size_t,
which have been corrected.
* po/size-t-for-vs:
object-file.c: LLP64 compatibility, upcast unity for left shift
diffcore-delta.c: LLP64 compatibility, upcast unity for left shift
repack.c: LLP64 compatibility, upcast unity for left shift
Visual Studio reports C4334 "was 64-bit shift intended" warning
because of size mismatch.
Promote unity to the matching type to fit with the `&` operator.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`git repack` invokes a handful of child processes: one to write the
actual pack, and optionally ones to repack promisor objects and update
the MIDX.
Most of these are freed automatically by calling `start_command()` (which
invokes it on error) and `finish_command()` which calls it
automatically.
But repack_promisor_objects() can initialize a child_process, populate
its array of arguments, and then return from the function before even
calling start_command().
Make sure that the prepared list of arguments is freed by calling
child_process_clear() ourselves to avoid leaking memory along this path.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git repack" has been taught to generate multi-pack reachability
bitmaps.
* tb/repack-write-midx:
test-read-midx: fix leak of bitmap_index struct
builtin/repack.c: pass `--refs-snapshot` when writing bitmaps
builtin/repack.c: make largest pack preferred
builtin/repack.c: support writing a MIDX while repacking
builtin/repack.c: extract showing progress to a variable
builtin/repack.c: rename variables that deal with non-kept packs
builtin/repack.c: keep track of existing packs unconditionally
midx: preliminary support for `--refs-snapshot`
builtin/multi-pack-index.c: support `--stdin-packs` mode
midx: expose `write_midx_file_only()` publicly
To prevent the race described in an earlier patch, generate and pass a
reference snapshot to the multi-pack bitmap code, if we are writing one
from `git repack`.
This patch is mostly limited to creating a temporary file, and then
calling for_each_ref(). Except we try to minimize duplicates, since
doing so can drastically reduce the size in network-of-forks style
repositories. In the kernel's fork network (the repository containing
all objects from the kernel and all its forks), deduplicating the
references drops the snapshot size from 934 MB to just 12 MB.
But since we're handling duplicates in this way, we have to make sure
that we preferred references (those listed in pack.preferBitmapTips)
before non-preferred ones (to avoid recording an object which is pointed
at by a preferred tip as non-preferred).
We accomplish this by doing separate passes over the references: first
visiting each prefix in pack.preferBitmapTips, and then over the rest of
the references.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When repacking into a geometric series and writing a multi-pack bitmap,
it is beneficial to have the largest resulting pack be the preferred
object source in the bitmap's MIDX, since selecting the large packs can
lead to fewer broken delta chains and better compression.
Teach 'git repack' to identify this pack and pass it to the MIDX write
machinery in order to mark it as preferred.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach `git repack` a new `--write-midx` option for callers that wish to
persist a multi-pack index in their repository while repacking.
There are two existing alternatives to this new flag, but they don't
cover our particular use-case. These alternatives are:
- Call 'git multi-pack-index write' after running 'git repack', or
- Set 'GIT_TEST_MULTI_PACK_INDEX=1' in your environment when running
'git repack'.
The former works, but introduces a gap in bitmap coverage between
repacking and writing a new MIDX (since the repack may have deleted a
pack included in the existing MIDX, invalidating it altogether).
Setting the 'GIT_TEST_' environment variable is obviously unsupported.
In fact, even if it were supported officially, it still wouldn't work,
because it generates the MIDX *after* redundant packs have been dropped,
leading to the same issue as above.
Introduce a new option which eliminates this race by teaching `git
repack` to generate the MIDX at the critical point: after the new packs
have been written and moved into place, but before the redundant packs
have been removed.
This option is compatible with `git repack`'s '--bitmap' option (it
changes the interpretation to be: "write a bitmap corresponding to the
MIDX after one has been generated").
There is a little bit of additional noise in the patch below to avoid
repeating ourselves when selecting which packs to delete. Instead of a
single loop as before (where we iterate over 'existing_packs', decide if
a pack is worth deleting, and if so, delete it), we have two loops (the
first where we decide which ones are worth deleting, and the second
where we actually do the deleting). This makes it so we have a single
check we can make consistently when (1) telling the MIDX which packs we
want to exclude, and (2) actually unlinking the redundant packs.
There is also a tiny change to short-circuit the body of
write_midx_included_packs() when no packs remain in the case of an empty
repository. The MIDX code does not handle this, so avoid trying to
generate a MIDX covering zero packs in the first place.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We only ask whether stderr is a tty before calling
'prune_packed_objects()', but the subsequent patch will add another use.
Extract this check into a variable so that both can use it without
having to call 'isatty()' twice.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new variable `existing_kept_packs` (and corresponding parameter
`fname_kept_list`) added by the previous patch make it seem like
`existing_packs` and `fname_list` are each subsets of the other two
respectively.
In reality, each pair is disjoint: one stores the packs without .keep
files, and the other stores the packs with .keep files. Rename each to
more clearly reflect this.
Suggested-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to be able to write a multi-pack index during repacking, `git
repack` must keep track of which packs it wants to write into the MIDX.
This set is the union of existing packs which will not be deleted,
new pack(s) generated as a result of the repack, and .keep packs.
Prior to this patch, `git repack` populated the list of existing packs
only when repacking all-into-one (i.e., with `-A` or `-a`), but we will
soon need to know this list when repacking when writing a MIDX without
a-i-o.
Populate the list of existing packs unconditionally, and guard removing
packs from that list only when repacking a-i-o.
Additionally, keep track of filenames of kept packs separately, since
this, too, will be used in an upcoming patch.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To figure out which commits we can write a bitmap for, the multi-pack
index/bitmap code does a reachability traversal, marking any commit
which can be found in the MIDX as eligible to receive a bitmap.
This approach will cause a problem when multi-pack bitmaps are able to
be generated from `git repack`, since the reference tips can change
during the repack. Even though we ignore commits that don't exist in
the MIDX (when doing a scan of the ref tips), it's possible that a
commit in the MIDX reaches something that isn't.
This can happen when a multi-pack index contains some pack which refers
to loose objects (e.g., if a pack was pushed after starting the repack
but before generating the MIDX which depends on an object which is
stored as loose in the repository, and by definition isn't included in
the multi-pack index).
By taking a snapshot of the references before we start repacking, we can
close that race window. In the above scenario (where we have a packed
object pointing at a loose one), we'll either (a) take a snapshot of the
references before seeing the packed one, or (b) take it after, at which
point we can guarantee that the loose object will be packed and included
in the MIDX.
This patch does just that. It writes a temporary "reference snapshot",
which is a list of OIDs that are at the ref tips before writing a
multi-pack bitmap. References that are "preferred" (i.e,. are a suffix
of at least one value of the 'pack.preferBitmapTips' configuration) are
marked with a special '+'.
The format is simple: one line per commit at each tip, with an optional
'+' at the beginning (for preferred references, as described above).
When provided, the reference snapshot is used to drive bitmap selection
instead of the MIDX code doing its own traversal. When it isn't
provided, the usual traversal takes place instead.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that GIT_REF_PARANOIA is the default, we don't need to selectively
enable it for destructive operations. In fact, it's harmful to do so,
because it overrides any GIT_REF_PARANOIA=0 setting that the user may
have provided (because they're trying to work around some corruption).
With these uses gone, we can further clean up the ref_paranoia global,
and make it a static variable inside the refs code.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren
Ævar Arnfjörð Bjarmason
Junio C Hamano
Taylor Blau
Jeff King
Jiang Xin
Victoria Dye
Patrick Steinhardt
Jean-Noël Avila
Derrick Stolee
Philip Oakley