Commit Graph

768 Commits

Author SHA1 Message Date
Junio C Hamano
777f548b5a Merge branch 'gc/bare-repo-discovery'
Allow configuration files in "protected" scopes to include other
configuration files.

* gc/bare-repo-discovery:
  config: respect includes in protected config
2022-10-25 17:11:44 -07:00
Glen Choo
ecec57b3c9 config: respect includes in protected config
Protected config is implemented by reading a fixed set of paths,
which ignores config [include]-s. Replace this implementation with a
call to config_with_options(), which handles [include]-s and saves us
from duplicating the logic of 1) identifying which paths to read and 2)
reading command line config.

As a result, git_configset_add_parameters() is unused, so remove it. It
was introduced alongside protected config in 5b3c650777 (config: learn
`git_protected_config()`, 2022-07-14) as a way to handle command line
config.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-13 11:39:46 -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
02c3c59e62 hashmap: mark unused callback parameters
Hashmap comparison functions must conform to a particular callback
interface, but many don't use all of their parameters. Especially the
void cmp_data pointer, but some do not use keydata either (because they
can easily form a full struct to pass when doing lookups). Let's mark
these 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 12:18:55 -07:00
Jeff King
783a86c142 config: mark unused callback parameters
The callback passed to git_config() must conform to a particular
interface. But most callbacks don't actually look at the extra "void
*data" parameter. Let's mark the unused parameters to make
-Wunused-parameter happy.

Note there's one unusual case here in get_remote_default() where we
actually ignore the "value" parameter. That's because it's only checking
whether the option is found at all, and not parsing its value.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 12:18:55 -07:00
Glen Choo
776f184893 config.c: NULL check when reading protected config
In read_protected_config(), check whether each file name is NULL before
attempting to read it, and add a BUG() call to
git_config_from_file_with_options() to make this error easier to catch
in the future.

The NULL checks mirror what do_git_config_sequence() does (which
read_protected_config() is modeled after). Without these NULL checks,
multiple tests fail with "make SANITIZE=address", e.g. in the final test
of t4010, xdg_config is NULL causing us to call fopen(NULL).

Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-26 23:46:01 -07:00
Glen Choo
5b3c650777 config: learn git_protected_config()
`uploadpack.packObjectsHook` is the only 'protected configuration only'
variable today, but we've noted that `safe.directory` and the upcoming
`safe.bareRepository` should also be 'protected configuration only'. So,
for consistency, we'd like to have a single implementation for protected
configuration.

The primary constraints are:

1. Reading from protected configuration should be fast. Nearly all "git"
   commands inside a bare repository will read both `safe.directory` and
   `safe.bareRepository`, so we cannot afford to be slow.

2. Protected configuration must be readable when the gitdir is not
   known. `safe.directory` and `safe.bareRepository` both affect
   repository discovery and the gitdir is not known at that point [1].

The chosen implementation in this commit is to read protected
configuration and cache the values in a global configset. This is
similar to the caching behavior we get with the_repository->config.

Introduce git_protected_config(), which reads protected configuration
and caches them in the global configset protected_config. Then, refactor
`uploadpack.packObjectsHook` to use git_protected_config().

The protected configuration functions are named similarly to their
non-protected counterparts, e.g. git_protected_config_check_init() vs
git_config_check_init().

In light of constraint 1, this implementation can still be improved.
git_protected_config() iterates through every variable in
protected_config, which is wasteful, but it makes the conversion simple
because it matches existing patterns. We will likely implement constant
time lookup functions for protected configuration in a future series
(such functions already exist for non-protected configuration, i.e.
repo_config_get_*()).

An alternative that avoids introducing another configset is to continue
to read all config using git_config(), but only accept values that have
the correct config scope [2]. This technically fulfills constraint 2,
because git_config() simply ignores the local and worktree config when
the gitdir is not known. However, this would read incomplete config into
the_repository->config, which would need to be reset when the gitdir is
known and git_config() needs to read the local and worktree config.
Resetting the_repository->config might be reasonable while we only have
these 'protected configuration only' variables, but it's not clear
whether this extends well to future variables.

[1] In this case, we do have a candidate gitdir though, so with a little
refactoring, it might be possible to provide a gitdir.
[2] This is how `uploadpack.packObjectsHook` was implemented prior to
this commit.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-14 15:08:29 -07:00
Junio C Hamano
83937e9592 Merge branch 'ns/batch-fsync'
Introduce a filesystem-dependent mechanism to optimize the way the
bits for many loose object files are ensured to hit the disk
platter.

* ns/batch-fsync:
  core.fsyncmethod: performance tests for batch mode
  t/perf: add iteration setup mechanism to perf-lib
  core.fsyncmethod: tests for batch mode
  test-lib-functions: add parsing helpers for ls-files and ls-tree
  core.fsync: use batch mode and sync loose objects by default on Windows
  unpack-objects: use the bulk-checkin infrastructure
  update-index: use the bulk-checkin infrastructure
  builtin/add: add ODB transaction around add_files_to_cache
  cache-tree: use ODB transaction around writing a tree
  core.fsyncmethod: batched disk flushes for loose-objects
  bulk-checkin: rebrand plug/unplug APIs as 'odb transactions'
  bulk-checkin: rename 'state' variable and separate 'plugged' boolean
2022-06-03 14:30:34 -07:00
Junio C Hamano
f49c478f62 Merge branch 'tk/simple-autosetupmerge'
"git -c branch.autosetupmerge=simple branch $A $B" will set the $B
as $A's upstream only when $A and $B shares the same name, and "git
-c push.default=simple" on branch $A would push to update the
branch $A at the remote $B came from.  Also more places use the
sole remote, if exists, before defaulting to 'origin'.

* tk/simple-autosetupmerge:
  push: new config option "push.autoSetupRemote" supports "simple" push
  push: default to single remote even when not named origin
  branch: new autosetupmerge option 'simple' for matching branches
2022-05-26 14:51:30 -07:00
Junio C Hamano
538dc459a0 Merge branch 'ep/maint-equals-null-cocci'
Introduce and apply coccinelle rule to discourage an explicit
comparison between a pointer and NULL, and applies the clean-up to
the maintenance track.

* ep/maint-equals-null-cocci:
  tree-wide: apply equals-null.cocci
  tree-wide: apply equals-null.cocci
  contrib/coccinnelle: add equals-null.cocci
2022-05-20 15:26:59 -07:00
Junio C Hamano
2b0a58d164 Merge branch 'ep/maint-equals-null-cocci' for maint-2.35
* ep/maint-equals-null-cocci:
  tree-wide: apply equals-null.cocci
  contrib/coccinnelle: add equals-null.cocci
2022-05-02 10:06:04 -07:00
Junio C Hamano
afe8a9070b tree-wide: apply equals-null.cocci
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-02 09:50:37 -07:00
Tao Klerks
bdaf1dfae7 branch: new autosetupmerge option 'simple' for matching branches
With the default push.default option, "simple", beginners are
protected from accidentally pushing to the "wrong" branch in
centralized workflows: if the remote tracking branch they would push
to does not have the same name as the local branch, and they try to do
a "default push", they get an error and explanation with options.

There is a particular centralized workflow where this often happens:
a user branches to a new local topic branch from an existing
remote branch, eg with "checkout -b feature1 origin/master". With
the default branch.autosetupmerge configuration (value "true"), git
will automatically add origin/master as the upstream tracking branch.

When the user pushes with a default "git push", with the intention of
pushing their (new) topic branch to the remote, they get an error, and
(amongst other things) a suggestion to run "git push origin HEAD".

If they follow this suggestion the push succeeds, but on subsequent
default pushes they continue to get an error - so eventually they
figure out to add "-u" to change the tracking branch, or they spelunk
the push.default config doc as proposed and set it to "current", or
some GUI tooling does one or the other of these things for them.

When one of their coworkers later works on the same topic branch,
they don't get any of that "weirdness". They just "git checkout
feature1" and everything works exactly as they expect, with the shared
remote branch set up as remote tracking branch, and push and pull
working out of the box.

The "stable state" for this way of working is that local branches have
the same-name remote tracking branch (origin/feature1 in this
example), and multiple people can work on that remote feature branch
at the same time, trusting "git pull" to merge or rebase as required
for them to be able to push their interim changes to that same feature
branch on that same remote.

(merging from the upstream "master" branch, and merging back to it,
are separate more involved processes in this flow).

There is a problem in this flow/way of working, however, which is that
the first user, when they first branched from origin/master, ended up
with the "wrong" remote tracking branch (different from the stable
state). For a while, before they pushed (and maybe longer, if they
don't use -u/--set-upstream), their "git pull" wasn't getting other
users' changes to the feature branch - it was getting any changes from
the remote "master" branch instead (a completely different class of
changes!)

An experienced git user might say "well yeah, that's what it means to
have the remote tracking branch set to origin/master!" - but the
original user above didn't *ask* to have the remote master branch
added as remote tracking branch - that just happened automatically
when they branched their feature branch. They didn't necessarily even
notice or understand the meaning of the "set up to track 'origin/master'"
message when they created the branch - especially if they are using a
GUI.

Looking at how to fix this, you might think "OK, so disable auto setup
of remote tracking - set branch.autosetupmerge to false" - but that
will inconvenience the *second* user in this story - the one who just
wanted to start working on the topic branch. The first and second
users swap roles at different points in time of course - they should
both have a sane configuration that does the right thing in both
situations.

Make this "branches have the same name locally as on the remote"
workflow less painful / more obvious by introducing a new
branch.autosetupmerge option called "simple", to match the same-name
"push.default" option that makes similar assumptions.

This new option automatically sets up tracking in a *subset* of the
current default situations: when the original ref is a remote tracking
branch *and* has the same branch name on the remote (as the new local
branch name).

Update the error displayed when the 'push.default=simple' configuration
rejects a mismatching-upstream-name default push, to offer this new
branch.autosetupmerge option that will prevent this class of error.

With this new configuration, in the example situation above, the first
user does *not* get origin/master set up as the tracking branch for
the new local branch. If they "git pull" in their new local-only
branch, they get an error explaining there is no upstream branch -
which makes sense and is helpful. If they "git push", they get an
error explaining how to push *and* suggesting they specify
--set-upstream - which is exactly the right thing to do for them.

This new option is likely not appropriate for users intentionally
implementing a "triangular workflow" with a shared upstream tracking
branch, that they "git pull" in and a "private" feature branch that
they push/force-push to just for remote safe-keeping until they are
ready to push up to the shared branch explicitly/separately. Such
users are likely to prefer keeping the current default
merge.autosetupmerge=true behavior, and change their push.default to
"current".

Also extend the existing branch tests with three new cases testing
this option - the obvious matching-name and non-matching-name cases,
and also a non-matching-ref-type case. The matching-name case needs to
temporarily create an independent repo to fetch from, as the general
strategy of using the local repo as the remote in these tests
precludes locally branching with the same name as in the "remote".

Signed-off-by: Tao Klerks <tao@klerks.biz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-29 11:20:55 -07:00
Neeraj Singh
8a94d83349 core.fsync: use batch mode and sync loose objects by default on Windows
Git for Windows has defaulted to core.fsyncObjectFiles=true since
September 2017. We turn on syncing of loose object files with batch mode
in upstream Git so that we can get broad coverage of the new code
upstream.

We don't actually do fsyncs in the most of the test suite, since
GIT_TEST_FSYNC is set to 0. However, we do exercise all of the
surrounding batch mode code since GIT_TEST_FSYNC merely makes the
maybe_fsync wrapper always appear to succeed.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-06 13:13:26 -07:00
Neeraj Singh
c0f4752ed2 core.fsyncmethod: batched disk flushes for loose-objects
When adding many objects to a repo with `core.fsync=loose-object`,
the cost of fsync'ing each object file can become prohibitive.

One major source of the cost of fsync is the implied flush of the
hardware writeback cache within the disk drive. This commit introduces
a new `core.fsyncMethod=batch` option that batches up hardware flushes.
It hooks into the bulk-checkin odb-transaction functionality, takes
advantage of tmp-objdir, and uses the writeout-only support code.

When the new mode is enabled, we do the following for each new object:
1a. Create the object in a tmp-objdir.
2a. Issue a pagecache writeback request and wait for it to complete.

At the end of the entire transaction when unplugging bulk checkin:
1b. Issue an fsync against a dummy file to flush the log and hardware
   writeback cache, which should by now have seen the tmp-objdir writes.
2b. Rename all of the tmp-objdir files to their final names.
3b. When updating the index and/or refs, we assume that Git will issue
   another fsync internal to that operation. This is not the default
   today, but the user now has the option of syncing the index and there
   is a separate patch series to implement syncing of refs.

On a filesystem with a singular journal that is updated during name
operations (e.g. create, link, rename, etc), such as NTFS, HFS+, or XFS
we would expect the fsync to trigger a journal writeout so that this
sequence is enough to ensure that the user's data is durable by the time
the git command returns. This sequence also ensures that no object files
appear in the main object store unless they are fsync-durable.

Batch mode is only enabled if core.fsync includes loose-objects. If
the legacy core.fsyncObjectFiles setting is enabled, but core.fsync does
not include loose-objects, we will use file-by-file fsyncing.

In step (1a) of the sequence, the tmp-objdir is created lazily to avoid
work if no loose objects are ever added to the ODB. We use a tmp-objdir
to maintain the invariant that no loose-objects are visible in the main
ODB unless they are properly fsync-durable. This is important since
future ODB operations that try to create an object with specific
contents will silently drop the new data if an object with the target
hash exists without checking that the loose-object contents match the
hash. Only a full git-fsck would restore the ODB to a functional state
where dataloss doesn't occur.

In step (1b) of the sequence, we issue a fsync against a dummy file
created specifically for the purpose. This method has a little higher
cost than using one of the input object files, but makes adding new
callers of this mechanism easier, since we don't need to figure out
which object file is "last" or risk sharing violations by caching the fd
of the last object file.

_Performance numbers_:

Linux - Hyper-V VM running Kernel 5.11 (Ubuntu 20.04) on a fast SSD.
Mac - macOS 11.5.1 running on a Mac mini on a 1TB Apple SSD.
Windows - Same host as Linux, a preview version of Windows 11.

Adding 500 files to the repo with 'git add' Times reported in seconds.

object file syncing | Linux | Mac   | Windows
--------------------|-------|-------|--------
           disabled | 0.06  |  0.35 | 0.61
              fsync | 1.88  | 11.18 | 2.47
              batch | 0.15  |  0.41 | 1.53

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-06 13:13:01 -07:00
Junio C Hamano
fca85986bb Merge branch 'ns/core-fsyncmethod' into ns/batch-fsync
* ns/core-fsyncmethod:
  configure.ac: fix HAVE_SYNC_FILE_RANGE definition
  core.fsyncmethod: correctly camel-case warning message
  core.fsync: fix incorrect expression for default configuration
  core.fsync: documentation and user-friendly aggregate options
  core.fsync: new option to harden the index
  core.fsync: add configuration parsing
  core.fsync: introduce granular fsync control infrastructure
  core.fsyncmethod: add writeout-only mode
  wrapper: make inclusion of Windows csprng header tightly scoped
2022-04-06 13:01:54 -07:00
Junio C Hamano
439c1e6d5d Merge branch 'jh/builtin-fsmonitor-part2'
Built-in fsmonitor (part 2).

* jh/builtin-fsmonitor-part2: (30 commits)
  t7527: test status with untracked-cache and fsmonitor--daemon
  fsmonitor: force update index after large responses
  fsmonitor--daemon: use a cookie file to sync with file system
  fsmonitor--daemon: periodically truncate list of modified files
  t/perf/p7519: add fsmonitor--daemon test cases
  t/perf/p7519: speed up test on Windows
  t/perf/p7519: fix coding style
  t/helper/test-chmtime: skip directories on Windows
  t/perf: avoid copying builtin fsmonitor files into test repo
  t7527: create test for fsmonitor--daemon
  t/helper/fsmonitor-client: create IPC client to talk to FSMonitor Daemon
  help: include fsmonitor--daemon feature flag in version info
  fsmonitor--daemon: implement handle_client callback
  compat/fsmonitor/fsm-listen-darwin: implement FSEvent listener on MacOS
  compat/fsmonitor/fsm-listen-darwin: add MacOS header files for FSEvent
  compat/fsmonitor/fsm-listen-win32: implement FSMonitor backend on Windows
  fsmonitor--daemon: create token-based changed path cache
  fsmonitor--daemon: define token-ids
  fsmonitor--daemon: add pathname classification
  fsmonitor--daemon: implement 'start' command
  ...
2022-04-04 10:56:24 -07:00
Junio C Hamano
27dd460799 Merge branch 'ns/core-fsyncmethod'
A couple of fix-up to a topic that is now in 'master'.

* ns/core-fsyncmethod:
  core.fsyncmethod: correctly camel-case warning message
  core.fsync: fix incorrect expression for default configuration
2022-04-04 10:56:22 -07:00
Neeraj Singh
f12f3b9807 core.fsyncmethod: correctly camel-case warning message
The warning for an unrecognized fsyncMethod was not
camel-cased.

Reported-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-30 14:46:08 -07:00
Jeff Hostetler
1e0ea5c431 fsmonitor: config settings are repository-specific
Move fsmonitor config settings to a new and opaque
`struct fsmonitor_settings` structure.  Add a lazily-loaded pointer
to this into `struct repo_settings`

Create an `enum fsmonitor_mode` type in `struct fsmonitor_settings` to
represent the state of fsmonitor.  This lets us represent which, if
any, fsmonitor provider (hook or IPC) is enabled.

Create `fsm_settings__get_*()` getters to lazily look up fsmonitor-
related config settings.

Get rid of the `core_fsmonitor` global variable.  Move the code to
lookup the existing `core.fsmonitor` config value into the fsmonitor
settings.

Create a hook pathname variable in `struct fsmonitor-settings` and
only set it when in hook mode.

Extend the definition of `core.fsmonitor` to be either a boolean
or a hook pathname.  When true, the builtin FSMonitor is used.
When false or unset, no FSMonitor (neither builtin nor hook) is
used.

The existing `core_fsmonitor` global variable was used to store the
pathname to the fsmonitor hook *and* it was used as a boolean to see
if fsmonitor was enabled.  This dual usage and global visibility leads
to confusion when we add the IPC-based provider.  So lets hide the
details in fsmonitor-settings.c and let it decide which provider to
use in the case of multiple settings.  This avoids cluttering up
repo-settings.c with these private details.

A future commit in builtin-fsmonitor series will add the ability to
disqualify worktrees for various reasons, such as being mounted from a
remote volume, where fsmonitor should not be started.  Having the
config settings hidden in fsmonitor-settings.c allows such worktree
restrictions to override the config values used.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:15 -07:00
Patrick Steinhardt
bc22d845c4 core.fsync: new option to harden references
When writing both loose and packed references to disk we first create a
lockfile, write the updated values into that lockfile, and on commit we
rename the file into place. According to filesystem developers, this
behaviour is broken because applications should always sync data to disk
before doing the final rename to ensure data consistency [1][2][3]. If
applications fail to do this correctly, a hard crash of the machine can
easily result in corrupted on-disk data.

This kind of corruption can in fact be easily observed with Git when the
machine hard-resets shortly after writing references to disk. On
machines with ext4, this will likely lead to the "empty files" problem:
the file has been renamed, but its data has not been synced to disk. The
result is that the reference is corrupt, and in the worst case this can
lead to data loss.

Implement a new option to harden references so that users and admins can
avoid this scenario by syncing locked loose and packed references to
disk before we rename them into place.

[1]: https://thunk.org/tytso/blog/2009/03/15/dont-fear-the-fsync/
[2]: https://btrfs.wiki.kernel.org/index.php/FAQ (What are the crash guarantees of overwrite-by-rename)
[3]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/ext4.rst (see auto_da_alloc)

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-15 13:30:58 -07:00
Junio C Hamano
0099792400 Merge branch 'ns/core-fsyncmethod' into ps/fsync-refs
* ns/core-fsyncmethod:
  core.fsync: documentation and user-friendly aggregate options
  core.fsync: new option to harden the index
  core.fsync: add configuration parsing
  core.fsync: introduce granular fsync control infrastructure
  core.fsyncmethod: add writeout-only mode
  wrapper: make inclusion of Windows csprng header tightly scoped
2022-03-15 13:30:37 -07:00
Neeraj Singh
b9f5d0358d core.fsync: documentation and user-friendly aggregate options
This commit adds aggregate options for the core.fsync setting that are
more user-friendly. These options are specified in terms of 'levels of
safety', indicating which Git operations are considered to be sync
points for durability.

The new documentation is also included here in its entirety for ease of
review.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-15 12:32:55 -07:00
Neeraj Singh
ba95e96d4c core.fsync: new option to harden the index
This commit introduces the new ability for the user to harden
the index. In the event of a system crash, the index must be
durable for the user to actually find a file that has been added
to the repo and then deleted from the working tree.

We use the presence of the COMMIT_LOCK flag and absence of the
alternate_index_output as a proxy for determining whether we're
updating the persistent index of the repo or some temporary
index. We don't sync these temporary indexes.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-10 15:10:22 -08:00
Neeraj Singh
844a8ad4f8 core.fsync: add configuration parsing
This change introduces code to parse the core.fsync setting and
configure the fsync_components variable.

core.fsync is configured as a comma-separated list of component names to
sync. Each time a core.fsync variable is encountered in the
configuration heirarchy, we start off with a clean state with the
platform default value. Passing 'none' resets the value to indicate
nothing will be synced. We gather all negative and positive entries from
the comma separated list and then compute the new value by removing all
the negative entries and adding all of the positive entries.

We issue a warning for components that are not recognized so that the
configuration code is compatible with configs from future versions of
Git with more repo components.

Complete documentation for the new setting is included in a later patch
in the series so that it can be reviewed once in final form.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-10 15:10:22 -08:00
Neeraj Singh
abf38abec2 core.fsyncmethod: add writeout-only mode
This commit introduces the `core.fsyncMethod` configuration
knob, which can currently be set to `fsync` or `writeout-only`.

The new writeout-only mode attempts to tell the operating system to
flush its in-memory page cache to the storage hardware without issuing a
CACHE_FLUSH command to the storage controller.

Writeout-only fsync is significantly faster than a vanilla fsync on
common hardware, since data is written to a disk-side cache rather than
all the way to a durable medium. Later changes in this patch series will
take advantage of this primitive to implement batching of hardware
flushes.

When git_fsync is called with FSYNC_WRITEOUT_ONLY, it may fail and the
caller is expected to do an ordinary fsync as needed.

On Apple platforms, the fsync system call does not issue a CACHE_FLUSH
directive to the storage controller. This change updates fsync to do
fcntl(F_FULLFSYNC) to make fsync actually durable. We maintain parity
with existing behavior on Apple platforms by setting the default value
of the new core.fsyncMethod option.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-10 15:10:22 -08:00
Junio C Hamano
82386b4496 Merge branch 'en/present-despite-skipped'
In sparse-checkouts, files mis-marked as missing from the working tree
could lead to later problems.  Such files were hard to discover, and
harder to correct.  Automatically detecting and correcting the marking
of such files has been added to avoid these problems.

* en/present-despite-skipped:
  repo_read_index: add config to expect files outside sparse patterns
  Accelerate clear_skip_worktree_from_present_files() by caching
  Update documentation related to sparsity and the skip-worktree bit
  repo_read_index: clear SKIP_WORKTREE bit from files present in worktree
  unpack-trees: fix accidental loss of user changes
  t1011: add testcase demonstrating accidental loss of user modifications
2022-03-09 13:38:23 -08:00
Elijah Newren
ecc7c8841d repo_read_index: add config to expect files outside sparse patterns
Typically with sparse checkouts, we expect files outside the sparsity
patterns to be marked as SKIP_WORKTREE and be missing from the working
tree.  Sometimes this expectation would be violated however; including
in cases such as:
  * users grabbing files from elsewhere and writing them to the worktree
    (perhaps by editing a cached copy in an editor, copying/renaming, or
     even untarring)
  * various git commands having incomplete or no support for the
    SKIP_WORKTREE bit[1,2]
  * users attempting to "abort" a sparse-checkout operation with a
    not-so-early Ctrl+C (updating $GIT_DIR/info/sparse-checkout and the
    working tree is not atomic)[3].
When the SKIP_WORKTREE bit in the index did not reflect the presence of
the file in the working tree, it traditionally caused confusion and was
difficult to detect and recover from.  So, in a sparse checkout, since
af6a51875a (repo_read_index: clear SKIP_WORKTREE bit from files present
in worktree, 2022-01-14), Git automatically clears the SKIP_WORKTREE
bit at index read time for entries corresponding to files that are
present in the working tree.

There is another workflow, however, where it is expected that paths
outside the sparsity patterns appear to exist in the working tree and
that they do not lose the SKIP_WORKTREE bit, at least until they get
modified.  A Git-aware virtual file system[4] takes advantage of its
position as a file system driver to expose all files in the working
tree, fetch them on demand using partial clone on access, and tell Git
to pay attention to them on demand by updating the sparse checkout
pattern on writes.  This means that commands like "git status" only have
to examine files that have potentially been modified, whereas commands
like "ls" are able to show the entire codebase without requiring manual
updates to the sparse checkout pattern.

Thus since af6a51875a, Git with such Git-aware virtual file systems
unsets the SKIP_WORKTREE bit for all files and commands like "git
status" have to fetch and examine them all.

Introduce a configuration setting sparse.expectFilesOutsideOfPatterns to
allow limiting the tracked set of files to a small set once again.  A
Git-aware virtual file system or other application that wants to
maintain files outside of the sparse checkout can set this in a
repository to instruct Git not to check for the presence of
SKIP_WORKTREE files.  The setting defaults to false, so most users of
sparse checkout will still get the benefit of an automatically updating
index to recover from the variety of difficult issues detailed in
af6a51875a for paths with SKIP_WORKTREE set despite the path being
present.

[1] https://lore.kernel.org/git/xmqqbmb1a7ga.fsf@gitster-ct.c.googlers.com/
[2] The three long paragraphs in the middle of
    https://lore.kernel.org/git/CABPp-BH9tju7WVm=QZDOvaMDdZbpNXrVWQdN-jmfN8wC6YVhmw@mail.gmail.com/
[3] https://lore.kernel.org/git/CABPp-BFnFpzwGC11TLoLs8YK5yiisA5D5-fFjXnJsbESVDwZsA@mail.gmail.com/
[4] such as the vfsd described in
https://lore.kernel.org/git/20220207190320.2960362-1-jonathantanmy@google.com/

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01 23:37:48 -08:00
Junio C Hamano
0a01df08c0 Merge branch 'ab/date-mode-release'
Plug (some) memory leaks around parse_date_format().

* ab/date-mode-release:
  date API: add and use a date_mode_release()
  date API: add basic API docs
  date API: provide and use a DATE_MODE_INIT
  date API: create a date.h, split from cache.h
  cache.h: remove always unused show_date_human() declaration
2022-02-25 15:47:36 -08:00
Junio C Hamano
6249ce2d1b Merge branch 'ds/sparse-checkout-requires-per-worktree-config'
"git sparse-checkout" wants to work with per-worktree configuration,
but did not work well in a worktree attached to a bare repository.

* ds/sparse-checkout-requires-per-worktree-config:
  config: make git_configset_get_string_tmp() private
  worktree: copy sparse-checkout patterns and config on add
  sparse-checkout: set worktree-config correctly
  config: add repo_config_set_worktree_gently()
  worktree: create init_worktree_config()
  Documentation: add extensions.worktreeConfig details
2022-02-25 15:47:33 -08:00
Ævar Arnfjörð Bjarmason
88c7b4c3c8 date API: create a date.h, split from cache.h
Move the declaration of the date.c functions from cache.h, and adjust
the relevant users to include the new date.h header.

The show_ident_date() function belonged in pretty.h (it's defined in
pretty.c), its two users outside of pretty.c didn't strictly need to
include pretty.h, as they get it indirectly, but let's add it to them
anyway.

Similarly, the change to "builtin/{fast-import,show-branch,tag}.c"
isn't needed as far as the compiler is concerned, but since they all
use the "DATE_MODE()" macro we now define in date.h, let's have them
include it.

We could simply include this new header in "cache.h", but as this
change shows these functions weren't common enough to warrant
including in it in the first place. By moving them out of cache.h
changes to this API will no longer cause a (mostly) full re-build of
the project when "make" is run.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-16 09:40:00 -08:00
Junio C Hamano
13ce8f9f14 Merge branch 'jt/conditional-config-on-remote-url'
The conditional inclusion mechanism of configuration files using
"[includeIf <condition>]" learns to base its decision on the
URL of the remote repository the repository interacts with.

* jt/conditional-config-on-remote-url:
  config: include file if remote URL matches a glob
  config: make git_config_include() static
2022-02-09 14:20:59 -08:00
Derrick Stolee
3ce1138272 config: make git_configset_get_string_tmp() private
This method was created in f1de981e8 (config: fix leaks from
git_config_get_string_const(), 2020-08-14) but its only use was in the
repo_config_get_string_tmp() method, also declared in config.h and
implemented in config.c. Since this is otherwise unused and is a very
similar implementation to git_configset_get_value(), let's remove this
declaration.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-08 09:49:21 -08:00
Derrick Stolee
fe18733927 config: add repo_config_set_worktree_gently()
Some config settings, such as those for sparse-checkout, are likely
intended to only apply to one worktree at a time. To make this write
easier, add a new config API method, repo_config_set_worktree_gently().

This method will attempt to write to the worktree-specific config, but
will instead write to the common config file if worktree config is not
enabled.  The next change will introduce a consumer of this method.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-08 09:49:20 -08:00
Jonathan Tan
399b198489 config: include file if remote URL matches a glob
This is a feature that supports config file inclusion conditional on
whether the repo has a remote with a URL that matches a glob.

Similar to my previous work on remote-suggested hooks [1], the main
motivation is to allow remote repo administrators to provide recommended
configs in a way that can be consumed more easily (e.g. through a
package installable by a package manager - it could, for example,
contain a file to be included conditionally and a post-install script
that adds the include directive to the system-wide config file).

In order to do this, Git reruns the config parsing mechanism upon
noticing the first URL-conditional include in order to find all remote
URLs, and these remote URLs are then used to determine if that first and
all subsequent includes are executed. Remote URLs are not allowed to be
configued in any URL-conditionally-included file.

[1] https://lore.kernel.org/git/cover.1623881977.git.jonathantanmy@google.com/

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-18 13:55:53 -08:00
Jonathan Tan
ed69e11b89 config: make git_config_include() static
It is not used from outside the file in which it is declared.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-18 13:55:53 -08:00
Junio C Hamano
0669bdf4eb Merge branch 'js/branch-track-inherit'
"git -c branch.autosetupmerge=inherit branch new old" makes "new"
to have the same upstream as the "old" branch, instead of marking
"old" itself as its upstream.

* js/branch-track-inherit:
  config: require lowercase for branch.*.autosetupmerge
  branch: add flags and config to inherit tracking
  branch: accept multiple upstream branches for tracking
2022-01-10 11:52:54 -08:00
Josh Steadmon
44f14a9d24 config: require lowercase for branch.*.autosetupmerge
Although we only documented that branch.*.autosetupmerge would accept
"always" as a value, the actual implementation would accept any
combination of upper- or lower-case. Fix this to be consistent with
documentation and with other values of this config variable.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-20 22:40:21 -08:00
Josh Steadmon
d3115660b4 branch: add flags and config to inherit tracking
It can be helpful when creating a new branch to use the existing
tracking configuration from the branch point. However, there is
currently not a method to automatically do so.

Teach git-{branch,checkout,switch} an "inherit" argument to the
"--track" option. When this is set, creating a new branch will cause the
tracking configuration to default to the configuration of the branch
point, if set.

For example, if branch "main" tracks "origin/main", and we run
`git checkout --track=inherit -b feature main`, then branch "feature"
will track "origin/main". Thus, `git status` will show us how far
ahead/behind we are from origin, and `git pull` will pull from origin.

This is particularly useful when creating branches across many
submodules, such as with `git submodule foreach ...` (or if running with
a patch such as [1], which we use at $job), as it avoids having to
manually set tracking info for each submodule.

Since we've added an argument to "--track", also add "--track=direct" as
another way to explicitly get the original "--track" behavior ("--track"
without an argument still works as well).

Finally, teach branch.autoSetupMerge a new "inherit" option. When this
is set, "--track=inherit" becomes the default behavior.

[1]: https://lore.kernel.org/git/20180927221603.148025-1-sbeller@google.com/

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-20 22:40:21 -08:00
Ævar Arnfjörð Bjarmason
f5c39c3268 config API: use get_error_routine(), not vreportf()
Change the git_die_config() function added in 5a80e97c82 (config: add
`git_die_config()` to the config-set API, 2014-08-07) to use the
public callbacks in the usage.[ch] API instead of the the underlying
vreportf() function.

In preceding commits the rest of the vreportf() users outside of
usage.c was migrated to die_message(), so we can now make it "static".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:25:16 -08:00
Ævar Arnfjörð Bjarmason
25ad722126 config.c: don't leak memory in handle_path_include()
Fix a memory leak in the error() path in handle_path_include(), this
allows us to run t1305-config-include.sh under SANITIZE=leak,
previously 4 tests there would fail. This fixes up a leak in
9b25a0b52e (config: add include directive, 2012-02-06).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-21 16:26:45 -07:00
Ævar Arnfjörð Bjarmason
73c5f67071 config.c: remove unused git_config_key_is_valid()
The git_config_key_is_valid() function got left behind in a
refactoring in a9bcf6586d (alias: use the early config machinery to
expand aliases, 2017-06-14),

It previously had two users when it was added in 9e9de18f1a (config:
silence warnings for command names with invalid keys, 2015-08-24), and
after 6a1e1bc0a1 (pager: use callbacks instead of configset,
2016-09-12) only one remained.

By removing it we can get rid of the "quiet" branches in this
function, as well as cases where "store_key" is NULL, for which there
are no other users.

Out of the 5 callers of git_config_parse_key() only one needs to pass
a non-NULL "size_t *baselen_", so we could remove the third parameter
from the public interface. I did not find that potential
simplification to be worthwhile.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 14:54:15 -07:00
Junio C Hamano
e3b77a2d03 Merge branch 'rs/drop-core-compression-vars'
Code clean-up.

* rs/drop-core-compression-vars:
  compression: drop write-only core_compression_* variables
2021-09-23 13:44:46 -07:00
Junio C Hamano
11e5d0a262 Merge branch 'jt/grep-wo-submodule-odb-as-alternate'
The code to make "git grep" recurse into submodules has been
updated to migrate away from the "add submodule's object store as
an alternate object store" mechanism (which is suboptimal).

* jt/grep-wo-submodule-odb-as-alternate:
  t7814: show lack of alternate ODB-adding
  submodule-config: pass repo upon blob config read
  grep: add repository to OID grep sources
  grep: allocate subrepos on heap
  grep: read submodule entry with explicit repo
  grep: typesafe versions of grep_source_init
  grep: use submodule-ODB-as-alternate lazy-addition
  submodule: lazily add submodule ODBs as alternates
2021-09-20 15:20:39 -07:00
René Scharfe
8f0f110156 compression: drop write-only core_compression_* variables
Since 8de7eeb54b (compression: unify pack.compression configuration
parsing, 2016-11-15) the variables core_compression_level and
core_compression_seen are only set, but never read.  Remove them.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-12 16:23:28 -07:00
Jonathan Tan
e3e8bf046e submodule-config: pass repo upon blob config read
When reading the config of a submodule, if reading from a blob, read
using an explicitly specified repository instead of by adding the
submodule's ODB as an alternate and then reading an object from
the_repository.

This makes the "grep --recurse-submodules with submodules without
.gitmodules in the working tree" test in t7814 work when
GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB is true.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-08 11:48:09 -07:00
Junio C Hamano
aab0eeaba5 Merge branch 'js/expand-runtime-prefix'
Pathname expansion (like "~username/") learned a way to specify a
location relative to Git installation (e.g. its $sharedir which is
$(prefix)/share), with "%(prefix)".

* js/expand-runtime-prefix:
  expand_user_path: allow in-flight topics to keep using the old name
  interpolate_path(): allow specifying paths relative to the runtime prefix
  Use a better name for the function interpolating paths
  expand_user_path(): clarify the role of the `real_home` parameter
  expand_user_path(): remove stale part of the comment
  tests: exercise the RUNTIME_PREFIX feature
2021-08-24 15:32:38 -07:00
Johannes Schindelin
a03b097d63 Use a better name for the function interpolating paths
It is not immediately clear what `expand_user_path()` means, so let's
rename it to `interpolate_path()`. This also opens the path for
interpolating more than just a home directory.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-26 12:17:16 -07:00
Junio C Hamano
8e62a85352 Merge branch 'ds/gender-neutral-doc'
Update the documentation not to assume users are of certain gender
and adds to guidelines to do so.

* ds/gender-neutral-doc:
  *: fix typos
  comments: avoid using the gender of our users
  doc: avoid using the gender of other people
2021-07-16 17:42:53 -07:00
Junio C Hamano
bd4232fac3 Merge branch 'ab/struct-init'
Code cleanup around struct_type_init() functions.

* ab/struct-init:
  string-list.h users: change to use *_{nodup,dup}()
  string-list.[ch]: add a string_list_init_{nodup,dup}()
  dir.[ch]: replace dir_init() with DIR_INIT
  *.c *_init(): define in terms of corresponding *_INIT macro
  *.h: move some *_INIT to designated initializers
2021-07-16 17:42:53 -07:00