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474 commits

Author SHA1 Message Date
Junio C Hamano 0f5e885173 Merge branch 'rc/fetch-refetch'
"git fetch --refetch" learned to fetch everything without telling
the other side what we already have, which is useful when you
cannot trust what you have in the local object store.

* rc/fetch-refetch:
  docs: mention --refetch fetch option
  fetch: after refetch, encourage auto gc repacking
  t5615-partial-clone: add test for fetch --refetch
  fetch: add --refetch option
  builtin/fetch-pack: add --refetch option
  fetch-pack: add refetch
  fetch-negotiator: add specific noop initializer
2022-04-04 10:56:23 -07:00
Robert Coup 7390f05a3c fetch: after refetch, encourage auto gc repacking
After invoking `fetch --refetch`, the object db will likely contain many
duplicate objects. If auto-maintenance is enabled, invoke it with
appropriate settings to encourage repacking/consolidation.

* gc.autoPackLimit: unless this is set to 0 (disabled), override the
  value to 1 to force pack consolidation.
* maintenance.incremental-repack.auto: unless this is set to 0, override
  the value to -1 to force incremental repacking.

Signed-off-by: Robert Coup <robert@coup.net.nz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-28 10:25:53 -07:00
Robert Coup 3c7bab06e1 fetch: add --refetch option
Teach fetch and transports the --refetch option to force a full fetch
without negotiating common commits with the remote. Use when applying a
new partial clone filter to refetch all matching objects.

Signed-off-by: Robert Coup <robert@coup.net.nz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-28 10:25:52 -07:00
Junio C Hamano dd9ff30dff Merge branch 'gc/recursive-fetch-with-unused-submodules'
When "git fetch --recurse-submodules" grabbed submodule commits
that would be needed to recursively check out newly fetched commits
in the superproject, it only paid attention to submodules that are
in the current checkout of the superproject.  We now do so for all
submodules that have been run "git submodule init" on.

* gc/recursive-fetch-with-unused-submodules:
  submodule: fix latent check_has_commit() bug
  fetch: fetch unpopulated, changed submodules
  submodule: move logic into fetch_task_create()
  submodule: extract get_fetch_task()
  submodule: store new submodule commits oid_array in a struct
  submodule: inline submodule_commits() into caller
  submodule: make static functions read submodules from commits
  t5526: create superproject commits with test helper
  t5526: stop asserting on stderr literally
  t5526: introduce test helper to assert on fetches
2022-03-25 16:38:25 -07:00
Junio C Hamano 6969ac64bf Merge branch 'ps/fetch-mirror-optim'
Various optimization for "git fetch".

* ps/fetch-mirror-optim:
  refs/files-backend: optimize reading of symbolic refs
  remote: read symbolic refs via `refs_read_symbolic_ref()`
  refs: add ability for backends to special-case reading of symbolic refs
  fetch: avoid lookup of commits when not appending to FETCH_HEAD
  upload-pack: look up "want" lines via commit-graph
2022-03-16 17:53:07 -07:00
Glen Choo b90d9f7632 fetch: fetch unpopulated, changed submodules
"git fetch --recurse-submodules" only considers populated
submodules (i.e. submodules that can be found by iterating the index),
which makes "git fetch" behave differently based on which commit is
checked out. As a result, even if the user has initialized all submodules
correctly, they may not fetch the necessary submodule commits, and
commands like "git checkout --recurse-submodules" might fail.

Teach "git fetch" to fetch cloned, changed submodules regardless of
whether they are populated. This is in addition to the current behavior
of fetching populated submodules (which is always attempted regardless
of what was fetched in the superproject, or even if nothing was fetched
in the superproject).

A submodule may be encountered multiple times (via the list of
populated submodules or via the list of changed submodules). When this
happens, "git fetch" only reads the 'populated copy' and ignores the
'changed copy'. Amend the verify_fetch_result() test helper so that we
can assert on which 'copy' is being read.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 16:08:59 -07:00
Junio C Hamano 851d2f0ab1 Merge branch 'ps/fetch-atomic'
"git fetch" can make two separate fetches, but ref updates coming
from them were in two separate ref transactions under "--atomic",
which has been corrected.

* ps/fetch-atomic:
  fetch: make `--atomic` flag cover pruning of refs
  fetch: make `--atomic` flag cover backfilling of tags
  refs: add interface to iterate over queued transactional updates
  fetch: report errors when backfilling tags fails
  fetch: control lifecycle of FETCH_HEAD in a single place
  fetch: backfill tags before setting upstream
  fetch: increase test coverage of fetches
2022-03-13 22:56:16 +00:00
Patrick Steinhardt 8e55634b47 fetch: avoid lookup of commits when not appending to FETCH_HEAD
When fetching from a remote repository we will by default write what has
been fetched into the special FETCH_HEAD reference. The order in which
references are written depends on whether the reference is for merge or
not, which, despite some other conditions, is also determined based on
whether the old object ID the reference is being updated from actually
exists in the repository.

To write FETCH_HEAD we thus loop through all references thrice: once for
the references that are about to be merged, once for the references that
are not for merge, and finally for all references that are ignored. For
every iteration, we then look up the old object ID to determine whether
the referenced object exists so that we can label it as "not-for-merge"
if it doesn't exist. It goes without saying that this can be expensive
in case where we are fetching a lot of references.

While this is hard to avoid in the case where we're writing FETCH_HEAD,
users can in fact ask us to skip this work via `--no-write-fetch-head`.
In that case, we do not care for the result of those lookups at all
because we don't have to order writes to FETCH_HEAD in the first place.

Skip this busywork in case we're not writing to FETCH_HEAD. The
following benchmark performs a mirror-fetch in a repository with about
two million references via `git fetch --prune --no-write-fetch-head
+refs/*:refs/*`:

    Benchmark 1: HEAD~
      Time (mean ± σ):     75.388 s ±  1.942 s    [User: 71.103 s, System: 8.953 s]
      Range (min … max):   73.184 s … 76.845 s    3 runs

    Benchmark 2: HEAD
      Time (mean ± σ):     69.486 s ±  1.016 s    [User: 65.941 s, System: 8.806 s]
      Range (min … max):   68.864 s … 70.659 s    3 runs

    Summary
      'HEAD' ran
        1.08 ± 0.03 times faster than 'HEAD~'

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01 10:13:46 -08:00
Junio C Hamano 34363403a2 Merge branch 'ps/fetch-atomic' into ps/fetch-mirror-optim
* ps/fetch-atomic:
  fetch: make `--atomic` flag cover pruning of refs
  fetch: make `--atomic` flag cover backfilling of tags
  refs: add interface to iterate over queued transactional updates
  fetch: report errors when backfilling tags fails
  fetch: control lifecycle of FETCH_HEAD in a single place
  fetch: backfill tags before setting upstream
  fetch: increase test coverage of fetches
2022-03-01 10:11:00 -08:00
Junio C Hamano d21d5ddfe6 Merge branch 'ja/i18n-common-messages'
Unify more messages to help l10n.

* ja/i18n-common-messages:
  i18n: fix some misformated placeholders in command synopsis
  i18n: remove from i18n strings that do not hold translatable parts
  i18n: factorize "invalid value" messages
  i18n: factorize more 'incompatible options' messages
2022-02-25 15:47:35 -08:00
Junio C Hamano 68fd3b35f7 Merge branch 'ps/fetch-optim-with-commit-graph'
A couple of optimization to "git fetch".

* ps/fetch-optim-with-commit-graph:
  fetch: skip computing output width when not printing anything
  fetch-pack: use commit-graph when computing cutoff
2022-02-23 16:58:03 -08:00
Junio C Hamano c5973cb98f Merge branch 'js/short-help-outside-repo-fix'
"git cmd -h" outside a repository should error out cleanly for many
commands, but instead it hit a BUG(), which has been corrected.

* js/short-help-outside-repo-fix:
  t0012: verify that built-ins handle `-h` even without gitdir
  checkout/fetch/pull/pack-objects: allow `-h` outside a repository
2022-02-18 13:53:30 -08:00
Junio C Hamano 18636afdce Merge branch 'ab/release-transport-ls-refs-options'
* ab/release-transport-ls-refs-options:
  ls-remote & transport API: release "struct transport_ls_refs_options"
2022-02-18 13:53:29 -08:00
Patrick Steinhardt 583bc41923 fetch: make --atomic flag cover pruning of refs
When fetching with the `--prune` flag we will delete any local
references matching the fetch refspec which have disappeared on the
remote. This step is not currently covered by the `--atomic` flag: we
delete branches even though updating of local references has failed,
which means that the fetch is not an all-or-nothing operation.

Fix this bug by passing in the global transaction into `prune_refs()`:
if one is given, then we'll only queue up deletions and not commit them
right away.

This change also improves performance when pruning many branches in a
repository with a big packed-refs file: every references is pruned in
its own transaction, which means that we potentially have to rewrite
the packed-refs files for every single reference we're about to prune.

The following benchmark demonstrates this: it performs a pruning fetch
from a repository with a single reference into a repository with 100k
references, which causes us to prune all but one reference. This is of
course a very artificial setup, but serves to demonstrate the impact of
only having to write the packed-refs file once:

    Benchmark 1: git fetch --prune --atomic +refs/*:refs/* (HEAD~)
      Time (mean ± σ):      2.366 s ±  0.021 s    [User: 0.858 s, System: 1.508 s]
      Range (min … max):    2.328 s …  2.407 s    10 runs

    Benchmark 2: git fetch --prune --atomic +refs/*:refs/* (HEAD)
      Time (mean ± σ):      1.369 s ±  0.017 s    [User: 0.715 s, System: 0.641 s]
      Range (min … max):    1.346 s …  1.400 s    10 runs

    Summary
      'git fetch --prune --atomic +refs/*:refs/* (HEAD)' ran
        1.73 ± 0.03 times faster than 'git fetch --prune --atomic +refs/*:refs/* (HEAD~)'

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-17 11:19:44 -08:00
Patrick Steinhardt b3a804663c fetch: make --atomic flag cover backfilling of tags
When fetching references from a remote we by default also fetch all tags
which point into the history we have fetched. This is a separate step
performed after updating local references because it requires us to walk
over the history on the client-side to determine whether the remote has
announced any tags which point to one of the fetched commits.

This backfilling of tags isn't covered by the `--atomic` flag: right
now, it only applies to the step where we update our local references.
This is an oversight at the time the flag was introduced: its purpose is
to either update all references or none, but right now we happily update
local references even in the case where backfilling failed.

Fix this by pulling up creation of the reference transaction such that
we can pass the same transaction to both the code which updates local
references and to the code which backfills tags. This allows us to only
commit the transaction in case both actions succeed.

Note that we also have to start passing the transaction into
`find_non_local_tags()`: this function is responsible for finding all
tags which we need to backfill. Right now, it will happily return tags
which have already been updated with our local references. But when we
use a single transaction for both local references and backfilling then
it may happen that we try to queue the same reference update twice to
the transaction, which consequently triggers a bug. We thus have to skip
over any tags which have already been queued.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-17 11:19:44 -08:00
Patrick Steinhardt 62091b4c87 fetch: report errors when backfilling tags fails
When the backfilling of tags fails we do not report this error to the
caller, but only report it implicitly at a later point when reporting
updated references. This leaves callers unable to act upon the
information of whether the backfilling succeeded or not.

Refactor the function to return an error code and pass it up the
callstack. This causes us to correctly propagate the error back to the
user of git-fetch(1).

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-17 11:19:44 -08:00
Patrick Steinhardt 2983cec0f2 fetch: control lifecycle of FETCH_HEAD in a single place
There are two different locations where we're appending to FETCH_HEAD:
first when storing updated references, and second when backfilling tags.
Both times we open the file, append to it and then commit it into place,
which is essentially duplicate work.

Improve the lifecycle of updating FETCH_HEAD by opening and committing
it once in `do_fetch()`, where we pass the structure down to the code
which wants to append to it.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-17 11:19:43 -08:00
Patrick Steinhardt efbade0660 fetch: backfill tags before setting upstream
The fetch code flow is a bit hard to understand right now:

    1. We optionally prune all references which have vanished on the
       remote side.
    2. We fetch and update all other references locally.
    3. We update the upstream branch in the gitconfig.
    4. We backfill tags pointing into the history we have just fetched.

It is quite confusing that we fetch objects and update references in
both (2) and (4), which is further stressed by the point that we use a
`skip` goto label to jump from (3) to (4) in case we fail to update the
gitconfig as expected.

Reorder the code to first update all local references, and only after we
have done so update the upstream branch information. This improves the
code flow and furthermore makes it easier to refactor the way we update
references together.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-17 11:19:43 -08:00
Junio C Hamano c73d46b3a8 Merge branch 'tg/fetch-prune-exit-code-fix'
When "git fetch --prune" failed to prune the refs it wanted to
prune, the command issued error messages but exited with exit
status 0, which has been corrected.

* tg/fetch-prune-exit-code-fix:
  fetch --prune: exit with error if pruning fails
2022-02-11 16:56:01 -08:00
Junio C Hamano b855f5045e Merge branch 'rc/negotiate-only-typofix'
Typofix.

* rc/negotiate-only-typofix:
  fetch: fix negotiate-only error message
2022-02-11 16:55:59 -08:00
Patrick Steinhardt b18aaaa5e9 fetch: skip computing output width when not printing anything
When updating references via git-fetch(1), then by default we report to
the user which references have been changed. This output is formatted in
a nice table such that the different columns are aligned. Because the
first column contains abbreviated object IDs we thus need to iterate
over all refs which have changed and compute the minimum length for
their respective abbreviated hashes. While this effort makes sense in
most cases, it is wasteful when the user passes the `--quiet` flag: we
don't print the summary, but still compute the length.

Skip computing the summary width when the user asked for us to be quiet.
This gives us a speedup of nearly 10% when doing a mirror-fetch in a
repository with thousands of references being updated:

    Benchmark 1: git fetch --quiet +refs/*:refs/* (HEAD~)
      Time (mean ± σ):     96.078 s ±  0.508 s    [User: 91.378 s, System: 10.870 s]
      Range (min … max):   95.449 s … 96.760 s    5 runs

    Benchmark 2: git fetch --quiet +refs/*:refs/* (HEAD)
      Time (mean ± σ):     88.214 s ±  0.192 s    [User: 83.274 s, System: 10.978 s]
      Range (min … max):   87.998 s … 88.446 s    5 runs

    Summary
      'git fetch --quiet +refs/*:refs/* (HEAD)' ran
        1.09 ± 0.01 times faster than 'git fetch --quiet +refs/*:refs/* (HEAD~)'

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-10 09:59:38 -08:00
Junio C Hamano 472a219f8d Merge branch 'gc/fetch-negotiate-only-early-return'
"git fetch --negotiate-only" is an internal command used by "git
push" to figure out which part of our history is missing from the
other side.  It should never recurse into submodules even when
fetch.recursesubmodules configuration variable is set, nor it
should trigger "gc".  The code has been tightened up to ensure it
only does common ancestry discovery and nothing else.

* gc/fetch-negotiate-only-early-return:
  fetch: help translators by reusing the same message template
  fetch --negotiate-only: do not update submodules
  fetch: skip tasks related to fetching objects
  fetch: use goto cleanup in cmd_fetch()
2022-02-09 14:20:59 -08:00
Johannes Schindelin 059fda1902 checkout/fetch/pull/pack-objects: allow -h outside a repository
When we taught these commands about the sparse index, we did not account
for the fact that the `cmd_*()` functions _can_ be called without a
gitdir, namely when `-h` is passed to show the usage.

A plausible approach to address this is to move the
`prepare_repo_settings()` calls right after the `parse_options()` calls:
The latter will never return when it handles `-h`, and therefore it is
safe to assume that we have a `gitdir` at that point, as long as the
built-in is marked with the `RUN_SETUP` flag.

However, it is unfortunately not that simple. In `cmd_pack_objects()`,
for example, the repo settings need to be fully populated so that the
command-line options `--sparse`/`--no-sparse` can override them, not the
other way round.

Therefore, we choose to imitate the strategy taken in `cmd_diff()`,
where we simply do not bother to prepare and initialize the repo
settings unless we have a `gitdir`.

This fixes https://github.com/git-for-windows/git/issues/3688

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-08 09:54:44 -08:00
Ævar Arnfjörð Bjarmason f36d4f8316 ls-remote & transport API: release "struct transport_ls_refs_options"
Fix a memory leak in codepaths that use the "struct
transport_ls_refs_options" API. Since the introduction of the struct
in 39835409d1 (connect, transport: encapsulate arg in struct,
2021-02-05) the caller has been responsible for freeing it.

That commit in turn migrated code originally added in
402c47d939 (clone: send ref-prefixes when using protocol v2,
2018-07-20) and b4be74105f (ls-remote: pass ref prefixes when
requesting a remote's refs, 2018-03-15). Only some of those codepaths
were releasing the allocated resources of the struct, now all of them
will.

Mark the "t/t5511-refspec.sh" test as passing when git is compiled
with SANITIZE=leak. They'll now be listed as running under the
"GIT_TEST_PASSING_SANITIZE_LEAK=true" test mode (the "linux-leaks" CI
target). Previously 24/47 tests would fail.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-06 18:02:34 -08:00
Jean-Noël Avila 1a8aea857e i18n: factorize "invalid value" messages
Use the same message when an invalid value is passed to a command line
option or a configuration variable.

Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-04 13:58:28 -08:00
Thomas Gummerer c9e04d905e fetch --prune: exit with error if pruning fails
When pruning refs fails, we print an error to stderr, but still
exit 0 from 'git fetch'.  Since this is a genuine error, fetch
should be exiting with some non-zero exit code.  Make it so.

The --prune option was introduced in f360d844de ("builtin-fetch: add
--prune option", 2009-11-10).  Unfortunately it's unclear from that
commit whether ignoring the exit code was an oversight or
intentional, but it feels like an oversight.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-31 11:18:37 -08:00
Robert Coup 2826ffad8c fetch: fix negotiate-only error message
The error message when invoking a negotiate-only fetch without providing
any tips incorrectly refers to a --negotiate-tip=* argument. Fix this to
use the actual argument, --negotiation-tip=*.

Signed-off-by: Robert Coup <robert@coup.net.nz>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-28 15:02:04 -08:00
Junio C Hamano de4eaae63a fetch: help translators by reusing the same message template
Follow the example set by 12909b6b (i18n: turn "options are
incompatible" into "cannot be used together", 2022-01-05) and use
the same message string to reduce the need for translation.

Reported-by: Jiang Xin <worldhello.net@gmail.com>
Helped-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-20 15:04:53 -08:00
Glen Choo 386c076a86 fetch --negotiate-only: do not update submodules
`git fetch --negotiate-only` is an implementation detail of push
negotiation and, unlike most `git fetch` invocations, does not actually
update the main repository. Thus it should not update submodules even
if submodule recursion is enabled.

This is not just slow, it is wrong e.g. push negotiation with
"submodule.recurse=true" will cause submodules to be updated because it
invokes `git fetch --negotiate-only`.

Fix this by disabling submodule recursion if --negotiate-only was given.
Since this makes --negotiate-only and --recurse-submodules incompatible,
check for this invalid combination and die.

This does not use the "goto cleanup" introduced in the previous commit
because we want to recurse through submodules whenever a ref is fetched,
and this can happen without introducing new objects.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-18 16:22:58 -08:00
Glen Choo 135a12bc14 fetch: skip tasks related to fetching objects
cmd_fetch() does the following with the assumption that objects are
fetched:

* Run gc
* Write commit graphs (if enabled by fetch.writeCommitGraph=true)

However, neither of these tasks makes sense if objects are not fetched
e.g. `git fetch --negotiate-only` never fetches objects.

Speed up cmd_fetch() by bailing out early if we know for certain that
objects will not be fetched. cmd_fetch() can bail out early whenever
objects are not fetched, but for now this only considers
--negotiate-only.

The same optimization does not apply to `git fetch --dry-run` because
that actually fetches objects; the dry run refers to not updating refs.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-18 16:22:57 -08:00
Glen Choo bec587d4c1 fetch: use goto cleanup in cmd_fetch()
Replace an early return with 'goto cleanup' in cmd_fetch() so that the
string_list is always cleared (the string_list_clear() call is purely
cleanup; the string_list is not reused). This makes cleanup consistent
so that a subsequent commit can use 'goto cleanup' to bail out early.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-18 16:22:53 -08:00
Junio C Hamano 12f82b0dd7 Merge branch 'ps/lockfile-cleanup-fix'
Some lockfile code called free() in signal-death code path, which
has been corrected.

* ps/lockfile-cleanup-fix:
  fetch: fix deadlock when cleaning up lockfiles in async signals
2022-01-12 15:11:43 -08:00
Junio C Hamano c17de5a505 Merge branch 'ja/i18n-similar-messages'
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"
2022-01-10 11:52:56 -08:00
Junio C Hamano 3c0e417827 Merge branch 'ds/fetch-pull-with-sparse-index'
"git fetch" and "git pull" are now declared sparse-index clean.
Also "git ls-files" learns the "--sparse" option to help debugging.

* ds/fetch-pull-with-sparse-index:
  test-read-cache: remove --table, --expand options
  t1091/t3705: remove 'test-tool read-cache --table'
  t1092: replace 'read-cache --table' with 'ls-files --sparse'
  ls-files: add --sparse option
  fetch/pull: use the sparse index
2022-01-10 11:52:50 -08:00
Patrick Steinhardt 58d4d7f1c5 fetch: fix deadlock when cleaning up lockfiles in async signals
When fetching packfiles, we write a bunch of lockfiles for the packfiles
we're writing into the repository. In order to not leave behind any
cruft in case we exit or receive a signal, we register both an exit
handler as well as signal handlers for common signals like SIGINT. These
handlers will then unlink the locks and free the data structure tracking
them. We have observed a deadlock in this logic though:

    (gdb) bt
    #0  __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:95
    #1  0x00007f4932bea2cd in _int_free (av=0x7f4932f2eb20 <main_arena>, p=0x3e3e4200, have_lock=0) at malloc.c:3969
    #2  0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
    #3  0x0000000000662ab1 in string_list_clear ()
    #4  0x000000000044f5bc in unlock_pack_on_signal ()
    #5  <signal handler called>
    #6  _int_free (av=0x7f4932f2eb20 <main_arena>, p=<optimized out>, have_lock=0) at malloc.c:4024
    #7  0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
    #8  0x000000000065afd5 in strbuf_release ()
    #9  0x000000000066ddb9 in delete_tempfile ()
    #10 0x0000000000610d0b in files_transaction_cleanup.isra ()
    #11 0x0000000000611718 in files_transaction_abort ()
    #12 0x000000000060d2ef in ref_transaction_abort ()
    #13 0x000000000060d441 in ref_transaction_prepare ()
    #14 0x000000000060e0b5 in ref_transaction_commit ()
    #15 0x00000000004511c2 in fetch_and_consume_refs ()
    #16 0x000000000045279a in cmd_fetch ()
    #17 0x0000000000407c48 in handle_builtin ()
    #18 0x0000000000408df2 in cmd_main ()
    #19 0x00000000004078b5 in main ()

The process was killed with a signal, which caused the signal handler to
kick in and try free the data structures after we have unlinked the
locks. It then deadlocks while calling free(3P).

The root cause of this is that it is not allowed to call certain
functions in async-signal handlers, as specified by signal-safety(7).
Next to most I/O functions, this list of disallowed functions also
includes memory-handling functions like malloc(3P) and free(3P) because
they may not be reentrant. As a result, if we execute such functions in
the signal handler, then they may operate on inconistent state and fail
in unexpected ways.

Fix this bug by not calling non-async-signal-safe functions when running
in the signal handler. We're about to re-raise the signal anyway and
will thus exit, so it's not much of a problem to keep the string list of
lockfiles untouched. Note that it's fine though to call unlink(2), so
we'll still clean up the lockfiles correctly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-07 13:49:19 -08:00
Jean-Noël Avila c4904377ba i18n: standardize "cannot open" and "cannot read"
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-05 13:29:23 -08:00
Jean-Noël Avila 43ea635c35 i18n: refactor "foo and bar are mutually exclusive"
Use static strings for constant parts of the sentences. They are all
turned into "cannot be used together".

Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-05 13:29:23 -08:00
Junio C Hamano dcaf17c75d Merge branch 'ab/fetch-set-upstream-while-detached'
"git fetch --set-upstream" did not check if there is a current
branch, leading to a segfault when it is run on a detached HEAD,
which has been corrected.

* ab/fetch-set-upstream-while-detached:
  pull, fetch: fix segfault in --set-upstream option
2021-12-22 22:48:10 -08:00
Derrick Stolee 5a4e0547e2 fetch/pull: use the sparse index
The 'git fetch' and 'git pull' commands parse the index in order to
determine if submodules exist. Without command_requires_full_index=0,
this will expand a sparse index, causing slow performance even when
there is no new data to fetch.

The .gitmodules file will never be inside a sparse directory entry, and
even if it was, the index_name_pos() method would expand the sparse
index if needed as we search for the path by name. These commands do not
iterate over the index, which is the typical thing we are careful about
when integrating with the sparse index.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-22 11:42:39 -08:00
Ævar Arnfjörð Bjarmason 17baeaf82d pull, fetch: fix segfault in --set-upstream option
Fix a segfault in the --set-upstream option added in
24bc1a1292 (pull, fetch: add --set-upstream option, 2019-08-19) added
in v2.24.0.

The code added there did not do the same checking we do for "git
branch" itself since 8efb8899cf (branch: segfault fixes and
validation, 2013-02-23), which in turn fixed the same sort of segfault
I'm fixing now in "git branch --set-upstream-to", see
6183d826ba (branch: introduce --set-upstream-to, 2012-08-20).

The warning message I'm adding here is an amalgamation of the error
added for "git branch" in 8efb8899cf, and the error output
install_branch_config() itself emits, i.e. it trims "refs/heads/" from
the name and says "branch X on remote", not "branch refs/heads/X on
remote".

I think it would make more sense to simply die() here, but in the
other checks for --set-upstream added in 24bc1a1292 we issue a
warning() instead. Let's do the same here for consistency for now.

There was an earlier submitted alternate way of fixing this in [1],
due to that patch breaking threading with the original report at [2] I
didn't notice it before authoring this version. I think the more
detailed warning message here is better, and we should also have tests
for this behavior.

The --no-rebase option to "git pull" is needed as of the recently
merged 7d0daf3f12 (Merge branch 'en/pull-conflicting-options',
2021-08-30).

1. https://lore.kernel.org/git/20210706162238.575988-1-clemens@endorphin.org/
2. https://lore.kernel.org/git/CAG6gW_uHhfNiHGQDgGmb1byMqBA7xa8kuH1mP-wAPEe5Tmi2Ew@mail.gmail.com/

Reported-by: Clemens Fruhwirth <clemens@endorphin.org>
Reported-by: Jan Pokorný <poki@fnusa.cz>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 15:19:28 -08:00
Anders Kaseorg 8bc1f39f41 fetch: protect branches checked out in all worktrees
Refuse to fetch into the currently checked out branch of any working
tree, not just the current one.

Fixes this previously reported bug:

https://lore.kernel.org/git/cb957174-5e9a-5603-ea9e-ac9b58a2eaad@mathema.de/

As a side effect of using find_shared_symref, we’ll also refuse the
fetch when we’re on a detached HEAD because we’re rebasing or bisecting
on the branch in question. This seems like a sensible change.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 22:18:25 -08:00
Anders Kaseorg 66996bea9b fetch: lowercase error messages
Documentation/CodingGuidelines says “do not end error messages with a
full stop” and “do not capitalize the first word”.  Clean up existing
messages, some of which we will be touching in later steps in the
series, that deviate from these rules in this file, as a preparation for
the main part of the topic.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 22:18:24 -08:00
Junio C Hamano c042ad5ad5 Merge branch 'js/run-command-close-packs'
The run-command API has been updated so that the callers can easily
ask the file descriptors open for packfiles to be closed immediately
before spawning commands that may trigger auto-gc.

* js/run-command-close-packs:
  Close object store closer to spawning child processes
  run_auto_maintenance(): implicitly close the object store
  run-command: offer to close the object store before running
  run-command: prettify the `RUN_COMMAND_*` flags
  pull: release packs before fetching
  commit-graph: when closing the graph, also release the slab
2021-09-20 15:20:45 -07:00
Junio C Hamano deec8aa2d0 Merge branch 'ps/fetch-optim'
Optimize code that handles large number of refs in the "git fetch"
code path.

* ps/fetch-optim:
  fetch: avoid second connectivity check if we already have all objects
  fetch: merge fetching and consuming refs
  fetch: refactor fetch refs to be more extendable
  fetch-pack: optimize loading of refs via commit graph
  connected: refactor iterator to return next object ID directly
  fetch: avoid unpacking headers in object existence check
  fetch: speed up lookup of want refs via commit-graph
2021-09-20 15:20:39 -07:00
Junio C Hamano fd0d7036e0 Merge branch 'ab/retire-advice-config'
Code clean up to migrate callers from older advice_config[] based
API to newer advice_if_enabled() and advice_enabled() API.

* ab/retire-advice-config:
  advice: move advice.graftFileDeprecated squashing to commit.[ch]
  advice: remove use of global advice_add_embedded_repo
  advice: remove read uses of most global `advice_` variables
  advice: add enum variants for missing advice variables
2021-09-10 11:46:29 -07:00
Junio C Hamano 87d4aed743 Merge branch 'ps/fetch-omit-formatting-under-quiet'
"git fetch --quiet" optimization to avoid useless computation of
info that will never be displayed.

* ps/fetch-omit-formatting-under-quiet:
  fetch: skip formatting updated refs with `--quiet`
2021-09-10 11:46:20 -07:00
Johannes Schindelin 5a22a334cb run_auto_maintenance(): implicitly close the object store
Before spawning the auto maintenance, we need to make sure that we
release all open file handles to all the `.pack` files (and MIDX files
and commit-graph files and...) so that the maintenance process has the
freedom to delete those files.

So far, we did this manually every time before calling
`run_auto_maintenance()`. With the new `close_object_store` flag, we can
do that implicitly in that function, which is more robust because future
callers won't be able to forget to close the object store.

Note: this changes behavior slightly, as we previously _always_ closed
the object store, but now we only close the object store when actually
running the auto maintenance. In practice, this should not matter (if
anything, it might speed up operations where auto maintenance is
disabled).

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 12:56:11 -07:00
Patrick Steinhardt caff8b7340 fetch: avoid second connectivity check if we already have all objects
When fetching refs, we are doing two connectivity checks:

    - The first one is done such that we can skip fetching refs in the
      case where we already have all objects referenced by the updated
      set of refs.

    - The second one verifies that we have all objects after we have
      fetched objects.

We always execute both connectivity checks, but this is wasteful in case
the first connectivity check already notices that we have all objects
locally available.

Skip the second connectivity check in case we already had all objects
available. This gives us a nice speedup when doing a mirror-fetch in a
repository with about 2.3M refs where the fetching repo already has all
objects:

    Benchmark #1: HEAD~: git-fetch
      Time (mean ± σ):     30.025 s ±  0.081 s    [User: 27.070 s, System: 4.933 s]
      Range (min … max):   29.900 s … 30.111 s    5 runs

    Benchmark #2: HEAD: git-fetch
      Time (mean ± σ):     25.574 s ±  0.177 s    [User: 22.855 s, System: 4.683 s]
      Range (min … max):   25.399 s … 25.765 s    5 runs

    Summary
      'HEAD: git-fetch' ran
        1.17 ± 0.01 times faster than 'HEAD~: git-fetch'

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-01 12:43:56 -07:00
Patrick Steinhardt 1c7d1ab6f4 fetch: merge fetching and consuming refs
The functions `fetch_refs()` and `consume_refs()` must always be called
together such that we first obtain all missing objects and then update
our local refs to match the remote refs. In a subsequent patch, we'll
further require that `fetch_refs()` must always be called before
`consume_refs()` such that it can correctly assert that we have all
objects after the fetch given that we're about to move the connectivity
check.

Make this requirement explicit by merging both functions into a single
`fetch_and_consume_refs()` function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-01 12:43:56 -07:00
Patrick Steinhardt 284b2ce8fc fetch: refactor fetch refs to be more extendable
Refactor `fetch_refs()` code to make it more extendable by explicitly
handling error cases. The refactored code should behave the same.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-01 12:43:56 -07:00