Commit Graph

384 Commits

Author SHA1 Message Date
Ben Peart
31d40058eb fscache: make fscache_enable() thread safe
The recent change to make fscache thread specific relied on fscache_enable()
being called first from the primary thread before being called in parallel
from worker threads.  Make that more robust and protect it with a critical
section to avoid any issues.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ben Peart <benpeart@microsoft.com>
2025-01-11 17:53:49 +01:00
Karsten Blees
6d933f6fce mingw: add infrastructure for read-only file system level caches
Add a macro to mark code sections that only read from the file system,
along with a config option and documentation.

This facilitates implementation of relatively simple file system level
caches without the need to synchronize with the file system.

Enable read-only sections for 'git status' and preload_index.

Signed-off-by: Karsten Blees <blees@dcon.de>
2025-01-11 17:53:47 +01:00
Karsten Blees
4d6c9ae3c6 Win32: make the lstat implementation pluggable
Emulating the POSIX lstat API on Windows via GetFileAttributes[Ex] is quite
slow. Windows operating system APIs seem to be much better at scanning the
status of entire directories than checking single files. A caching
implementation may improve performance by bulk-reading entire directories
or reusing data obtained via opendir / readdir.

Make the lstat implementation pluggable so that it can be switched at
runtime, e.g. based on a config option.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:53:47 +01:00
Karsten Blees
8765262b7e Win32: make FILETIME conversion functions public
We will use them in the upcoming "FSCache" patches (to accelerate
sequential lstat() calls).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:53:47 +01:00
Johannes Schindelin
e96b511cd5 credential-cache: handle ECONNREFUSED gracefully (#5329)
I should probably add some tests for this.
2025-01-11 17:53:46 +01:00
Johannes Schindelin
c6d0e624c7 Additional error checks for issuing the windows.appendAtomically warning (#4528)
Another (hopefully clean) PR for showing the error warning about atomic
append on windows after failure on APFS, which returns EBADF not EINVAL.

Signed-off-by: David Lomas <dl3@pale-eds.co.uk>
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
2025-01-11 17:53:43 +01:00
Johannes Schindelin
eb10a5f045 Merge branch 'fsync-object-files-always'
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:53:40 +01:00
Johannes Schindelin
9443af7220 Merge branch 'optionally-dont-append-atomically-on-windows'
Fix append failure issue under remote directories #2753

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:53:40 +01:00
Johannes Schindelin
9c2fbec993 Merge pull request #3751 from rkitover/native-term
mingw: set $env:TERM=xterm-256color for newer OSes
2025-01-11 17:53:40 +01:00
Derrick Stolee
88b418e77f Merge pull request #3791: Various fixes around safe.directory
The first three commits are rebased versions of those in gitgitgadget/git#1215. These allow the following:

1. Fix `git config --global foo.bar <path>` from allowing the `<path>`. As a bonus, users with a config value starting with `/` will not get a warning about "old-style" paths needing a "`%(prefix)/`".

2. When in WSL, the path starts with `/` so it needs to be interpolated properly. Update the warning to include `%(prefix)/` to get the right value for WSL users. (This is specifically for using Git for Windows from Git Bash, but in a WSL directory.)

3. When using WSL, the ownership check fails and reports an error message. This is noisy, and happens even if the user has marked the path with `safe.directory`. Remove that error message.
2025-01-11 17:53:40 +01:00
Johannes Schindelin
8b1def008c Merge pull request #3165 from dscho/increase-allowed-length-of-interpreter-path
mingw: allow for longer paths in `parse_interpreter()`
2025-01-11 17:53:38 +01:00
Johannes Schindelin
ed17cfbe36 Merge pull request #2506 from dscho/issue-2283
Allow running Git directly from `C:\Program Files\Git\mingw64\bin\git.exe`
2025-01-11 17:53:36 +01:00
Johannes Schindelin
b337de4bd4 Merge pull request #2504 from dscho/access-repo-via-junction
Handle `git add <file>` where <file> traverses an NTFS junction
2025-01-11 17:53:35 +01:00
Johannes Schindelin
d713b0d095 Merge pull request #2488 from bmueller84/master
mingw: fix fatal error working on mapped network drives on Windows
2025-01-11 17:53:35 +01:00
Johannes Schindelin
6239a8f50a Merge pull request #2449 from dscho/mingw-getcwd-and-symlinks
Do resolve symlinks in `getcwd()`
2025-01-11 17:53:35 +01:00
Johannes Schindelin
eafefa0f9c Merge branch 'dont-clean-junctions'
This topic branch teaches `git clean` to respect NTFS junctions and Unix
bind mounts: it will now stop at those boundaries.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:49:44 +01:00
Matthias Aßhauer
fd6b18f186 compat/mingw: drop outdated comment
This comment has been true for the longest time; The combination of the
two preceding commits made it incorrect, so let's drop that comment.

Signed-off-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:43:52 +01:00
Matthias Aßhauer
78e72dcb91 compat/mingw: handle WSA errors in strerror
We map WSAGetLastError() errors to errno errors in winsock_error_to_errno(),
but the MSVC strerror() implementation only produces "Unknown error" for
most of them. Produce some more meaningful error messages in these
cases.

Our builds for ARM64 link against the newer UCRT strerror() that does know
these errors, so we won't change the strerror() used there.

The wording of the messages is copied from glibc strerror() messages.

Reported-by: M Hickford <mirth.hickford@gmail.com>
Signed-off-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:43:46 +01:00
Johannes Schindelin
5c9651358f mingw: make sure errno is set correctly when socket operations fail
The winsock2 library provides functions that work on different data
types than file descriptors, therefore we wrap them.

But that is not the only difference: they also do not set `errno` but
expect the callers to enquire about errors via `WSAGetLastError()`.

Let's translate that into appropriate `errno` values whenever the socket
operations fail so that Git's code base does not have to change its
expectations.

This closes https://github.com/git-for-windows/git/issues/2404

Helped-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:43:32 +01:00
David Lomas
171878e1b3 mingw: suggest windows.appendAtomically in more cases
When running Git for Windows on a remote APFS filesystem, it would
appear that the `mingw_open_append()`/`write()` combination would fail
almost exactly like on some CIFS-mounted shares as had been reported in
https://github.com/git-for-windows/git/issues/2753, albeit with a
different `errno` value.

Let's handle that `errno` value just the same, by suggesting to set
`windows.appendAtomically=false`.

Signed-off-by: David Lomas <dl3@pale-eds.co.uk>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:35 +01:00
Johannes Schindelin
3f98d1317a mingw: change core.fsyncObjectFiles = 1 by default
From the documentation of said setting:

	This boolean will enable fsync() when writing object files.

	This is a total waste of time and effort on a filesystem that
	orders data writes properly, but can be useful for filesystems
	that do not use journalling (traditional UNIX filesystems) or
	that only journal metadata and not file contents (OS X’s HFS+,
	or Linux ext3 with "data=writeback").

The most common file system on Windows (NTFS) does not guarantee that
order, therefore a sudden loss of power (or any other event causing an
unclean shutdown) would cause corrupt files (i.e. files filled with
NULs). Therefore we need to change the default.

Note that the documentation makes it sound as if this causes really bad
performance. In reality, writing loose objects is something that is done
only rarely, and only a handful of files at a time.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:33 +01:00
孙卓识
cadcb6dd24 Add config option windows.appendAtomically
Atomic append on windows is only supported on local disk files, and it may
cause errors in other situations, e.g. network file system. If that is the
case, this config option should be used to turn atomic append off.

Co-Authored-By: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: 孙卓识 <sunzhuoshi@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:33 +01:00
Rafael Kitover
c71eebaae7 mingw: $env:TERM="xterm-256color" for newer OSes
For Windows builds >= 15063 set $env:TERM to "xterm-256color" instead of
"cygwin" because they have a more capable console system that supports
this. Also set $env:COLORTERM="truecolor" if unset.

$env:TERM is initialized so that ANSI colors in color.c work, see
29a3963484 (Win32: patch Windows environment on startup, 2012-01-15).

See git-for-windows/git#3629 regarding problems caused by always setting
$env:TERM="cygwin".

This is the same heuristic used by the Cygwin runtime.

Signed-off-by: Rafael Kitover <rkitover@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:33 +01:00
Derrick Stolee
307bb0547e compat/mingw.c: do not warn when failing to get owner
In the case of Git for Windows (say, in a Git Bash window) running in a
Windows Subsystem for Linux (WSL) directory, the GetNamedSecurityInfoW()
call in is_path_owned_By_current_side() returns an error code other than
ERROR_SUCCESS. This is consistent behavior across this boundary.

In these cases, the owner would always be different because the WSL
owner is a different entity than the Windows user.

The change here is to suppress the error message that looks like this:

  error: failed to get owner for '//wsl.localhost/...' (1)

Before this change, this warning happens for every Git command,
regardless of whether the directory is marked with safe.directory.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
2025-01-11 17:19:32 +01:00
Johannes Schindelin
1e95a2f612 mingw: allow for longer paths in parse_interpreter()
As reported in https://github.com/newren/git-filter-repo/pull/225, it
looks like 99 bytes is not really sufficient to represent e.g. the full
path to Python when installed via Windows Store (and this path is used
in the hasb bang line when installing scripts via `pip`).

Let's increase it to what is probably the maximum sensible path size:
MAX_PATH. This makes `parse_interpreter()` in line with what
`lookup_prog()` handles.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Vilius Šumskas <vilius@sumskas.eu>
2025-01-11 17:19:31 +01:00
Johannes Schindelin
3db90c39c0 mingw: ignore HOMEDRIVE/HOMEPATH if it points to Windows' system directory
Internally, Git expects the environment variable `HOME` to be set, and
to point to the current user's home directory.

This environment variable is not set by default on Windows, and
therefore Git tries its best to construct one if it finds `HOME` unset.

There are actually two different approaches Git tries: first, it looks
at `HOMEDRIVE`/`HOMEPATH` because this is widely used in corporate
environments with roaming profiles, and a user generally wants their
global Git settings to be in a roaming profile.

Only when `HOMEDRIVE`/`HOMEPATH` is either unset or does not point to a
valid location, Git will fall back to using `USERPROFILE` instead.

However, starting with Windows Vista, for secondary logons and services,
the environment variables `HOMEDRIVE`/`HOMEPATH` point to Windows'
system directory (usually `C:\Windows\system32`).

That is undesirable, and that location is usually write-protected anyway.

So let's verify that the `HOMEDRIVE`/`HOMEPATH` combo does not point to
Windows' system directory before using it, falling back to `USERPROFILE`
if it does.

This fixes git-for-windows#2709

Initial-Path-by: Ivan Pozdeev <vano@mail.mipt.ru>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:28 +01:00
Johannes Schindelin
132f4314d1 mingw: implement a platform-specific strbuf_realpath()
There is a Win32 API function to resolve symbolic links, and we can use
that instead of resolving them manually. Even better, this function also
resolves NTFS junction points (which are somewhat similar to bind
mounts).

This fixes https://github.com/git-for-windows/git/issues/2481.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:28 +01:00
Bjoern Mueller
2b6f2917bb mingw: fix fatal error working on mapped network drives on Windows
In 1e64d18 (mingw: do resolve symlinks in `getcwd()`) a problem was
introduced that causes git for Windows to stop working with certain
mapped network drives (in particular, drives that are mapped to
locations with long path names). Error message was "fatal: Unable to
read current working directory: No such file or directory". Present
change fixes this issue as discussed in
https://github.com/git-for-windows/git/issues/2480

Signed-off-by: Bjoern Mueller <bjoernm@gmx.de>
2025-01-11 17:19:28 +01:00
Johannes Schindelin
d7476fc7eb mingw: do resolve symlinks in getcwd()
As pointed out in https://github.com/git-for-windows/git/issues/1676,
the `git rev-parse --is-inside-work-tree` command currently fails when
the current directory's path contains symbolic links.

The underlying reason for this bug is that `getcwd()` is supposed to
resolve symbolic links, but our `mingw_getcwd()` implementation did not.

We do have all the building blocks for that, though: the
`GetFinalPathByHandleW()` function will resolve symbolic links. However,
we only called that function if `GetLongPathNameW()` failed, for
historical reasons: the latter function was supported for a long time,
but the former API function was introduced only with Windows Vista, and
we used to support also Windows XP. With that support having been
dropped, we are free to call the symbolic link-resolving function right
away.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:28 +01:00
Johannes Schindelin
345d8dd1b6 mingw: allow git.exe to be used instead of the "Git wrapper"
Git for Windows wants to add `git.exe` to the users' `PATH`, without
cluttering the latter with unnecessary executables such as `wish.exe`.
To that end, it invented the concept of its "Git wrapper", i.e. a tiny
executable located in `C:\Program Files\Git\cmd\git.exe` (originally a
CMD script) whose sole purpose is to set up a couple of environment
variables and then spawn the _actual_ `git.exe` (which nowadays lives in
`C:\Program Files\Git\mingw64\bin\git.exe` for 64-bit, and the obvious
equivalent for 32-bit installations).

Currently, the following environment variables are set unless already
initialized:

- `MSYSTEM`, to make sure that the MSYS2 Bash and the MSYS2 Perl
  interpreter behave as expected, and

- `PLINK_PROTOCOL`, to force PuTTY's `plink.exe` to use the SSH
  protocol instead of Telnet,

- `PATH`, to make sure that the `bin` folder in the user's home
  directory, as well as the `/mingw64/bin` and the `/usr/bin`
  directories are included. The trick here is that the `/mingw64/bin/`
  and `/usr/bin/` directories are relative to the top-level installation
  directory of Git for Windows (which the included Bash interprets as
  `/`, i.e. as the MSYS pseudo root directory).

Using the absence of `MSYSTEM` as a tell-tale, we can detect in
`git.exe` whether these environment variables have been initialized
properly. Therefore we can call `C:\Program Files\Git\mingw64\bin\git`
in-place after this change, without having to call Git through the Git
wrapper.

Obviously, above-mentioned directories must be _prepended_ to the `PATH`
variable, otherwise we risk picking up executables from unrelated Git
installations. We do that by constructing the new `PATH` value from
scratch, appending `$HOME/bin` (if `HOME` is set), then the MSYS2 system
directories, and then appending the original `PATH`.

Side note: this modification of the `PATH` variable is independent of
the modification necessary to reach the executables and scripts in
`/mingw64/libexec/git-core/`, i.e. the `GIT_EXEC_PATH`. That
modification is still performed by Git, elsewhere, long after making the
changes described above.

While we _still_ cannot simply hard-link `mingw64\bin\git.exe` to `cmd`
(because the former depends on a couple of `.dll` files that are only in
`mingw64\bin`, i.e. calling `...\cmd\git.exe` would fail to load due to
missing dependencies), at least we can now avoid that extra process of
running the Git wrapper (which then has to wait for the spawned
`git.exe` to finish) by calling `...\mingw64\bin\git.exe` directly, via
its absolute path.

Testing this is in Git's test suite tricky: we set up a "new" MSYS
pseudo-root and copy the `git.exe` file into the appropriate location,
then verify that `MSYSTEM` is set properly, and also that the `PATH` is
modified so that scripts can be found in `$HOME/bin`, `/mingw64/bin/`
and `/usr/bin/`.

This addresses https://github.com/git-for-windows/git/issues/2283

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:28 +01:00
Johannes Schindelin
0cb219f0a4 mingw: ensure valid CTYPE
A change between versions 2.4.1 and 2.6.0 of the MSYS2 runtime modified
how Cygwin's runtime (and hence Git for Windows' MSYS2 runtime
derivative) handles locales: d16a56306d (Consolidate wctomb/mbtowc calls
for POSIX-1.2008, 2016-07-20).

An unintended side-effect is that "cold-calling" into the POSIX
emulation will start with a locale based on the current code page,
something that Git for Windows is very ill-prepared for, as it expects
to be able to pass a command-line containing non-ASCII characters to the
shell without having those characters munged.

One symptom of this behavior: when `git clone` or `git fetch` shell out
to call `git-upload-pack` with a path that contains non-ASCII
characters, the shell tried to interpret the entire command-line
(including command-line parameters) as executable path, which obviously
must fail.

This fixes https://github.com/git-for-windows/git/issues/1036

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:28 +01:00
Johannes Schindelin
e75cb3b514 mingw: allow absolute paths without drive prefix
When specifying an absolute path without a drive prefix, we convert that
path internally. Let's make sure that we handle that case properly, too
;-)

This fixes the command

	git clone https://github.com/git-for-windows/git \G4W

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:08 +01:00
Johannes Schindelin
c2b8b3d3d9 clean: do not traverse mount points
It seems to be not exactly rare on Windows to install NTFS junction
points (the equivalent of "bind mounts" on Linux/Unix) in worktrees,
e.g. to map some development tools into a subdirectory.

In such a scenario, it is pretty horrible if `git clean -dfx` traverses
into the mapped directory and starts to "clean up".

Let's just not do that. Let's make sure before we traverse into a
directory that it is not a mount point (or junction).

This addresses https://github.com/git-for-windows/git/issues/607

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-01-11 17:19:08 +01:00
Junio C Hamano
c4cc685a62 Merge branch 'js/mingw-rename-fix'
Update the way rename() emulation on Windows handle directories to
correct an earlier attempt to do the same.

* js/mingw-rename-fix:
  mingw_rename: do support directory renames
2024-12-23 09:32:16 -08:00
Johannes Schindelin
b30404dfc0 mingw_rename: do support directory renames
In 391bceae43 (compat/mingw: support POSIX semantics for atomic
renames, 2024-10-27), we taught the `mingw_rename()` function to respect
POSIX semantics, but we did so only as a fallback after `_wrename()`
fails.

This hid a bug in the implementation that was not caught by Git's test
suite: The `CreateFileW()` function _can_ open handles to directories,
but not when asked to use the `FILE_ATTRIBUTE_NORMAL` flag, as that flag
only is allowed for files.

Let's fix this by using the common `FILE_FLAG_BACKUP_SEMANTICS` flag
that can be used for opening handles to directories, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-17 12:06:59 -08:00
Patrick Steinhardt
41f43b8243 global: mark code units that generate warnings with -Wsign-compare
Mark code units that generate warnings with `-Wsign-compare`. This
allows for a structured approach to get rid of all such warnings over
time in a way that can be easily measured.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-06 20:20:02 +09:00
Junio C Hamano
183ea3eabf Merge branch 'ps/mingw-rename'
The MinGW compatibility layer has been taught to support POSIX
semantics for atomic renames when other process(es) have a file
opened at the destination path.

* ps/mingw-rename:
  compat/mingw: support POSIX semantics for atomic renames
  compat/mingw: allow deletion of most opened files
  compat/mingw: share file handles created via `CreateFileW()`
2024-11-13 08:35:34 +09:00
Patrick Steinhardt
391bceae43 compat/mingw: support POSIX semantics for atomic renames
By default, Windows restricts access to files when those files have been
opened by another process. As explained in the preceding commits, these
restrictions can be loosened such that reads, writes and/or deletes of
files with open handles _are_ allowed.

While we set up those sharing flags in most relevant code paths now, we
still don't properly handle POSIX-style atomic renames in case the
target path is open. This is failure demonstrated by t0610, where one of
our tests spawns concurrent writes in a reftable-enabled repository and
expects all of them to succeed. This test fails most of the time because
the process that has acquired the "tables.list" lock is unable to rename
it into place while other processes are busy reading that file.

Windows 10 has introduced the `FILE_RENAME_FLAG_POSIX_SEMANTICS` flag
that allows us to fix this usecase [1]. When set, it is possible to
rename a file over a preexisting file even when the target file still
has handles open. Those handles must have been opened with the
`FILE_SHARE_DELETE` flag, which we have ensured in the preceding
commits.

Careful readers might have noticed that [1] does not mention the above
flag, but instead mentions `FILE_RENAME_POSIX_SEMANTICS`. This flag is
not for use with `SetFileInformationByHandle()` though, which is what we
use. And while the `FILE_RENAME_FLAG_POSIX_SEMANTICS` flag exists, it is
not documented on [2] or anywhere else as far as I can tell.

Unfortunately, we still support Windows systems older than Windows 10
that do not yet have this new flag. Our `_WIN32_WINNT` SDK version still
targets 0x0600, which is Windows Vista and later. And even though that
Windows version is out-of-support, bumping the SDK version all the way
to 0x0A00, which is Windows 10 and later, is not an option as it would
make it impossible to compile on Windows 8.1, which is still supported.
Instead, we have to manually declare the relevant infrastructure to make
this feature available and have fallback logic in place in case we run
on a Windows version that does not yet have this flag.

On another note: `mingw_rename()` has a retry loop that is used in case
deleting a file failed because it's still open in another process. One
might be pressed to not use this loop anymore when we can use POSIX
semantics. But unfortunately, we have to keep it around due to our
dependence on the `FILE_SHARE_DELETE` flag. While we know to set that
sharing flag now, other applications may not do so and may thus still
cause sharing violations when we try to rename a file.

This fixes concurrent writes in the reftable backend as demonstrated in
t0610, but may also end up fixing other usecases where Git wants to
perform renames.

[1]: https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/ntifs/ns-ntifs-_file_rename_information
[2]: https://learn.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-file_rename_info

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-11-06 00:15:25 -08:00
Patrick Steinhardt
a270cb1540 compat/mingw: allow deletion of most opened files
On Windows, we emulate open(3p) via `mingw_open()`. This function
implements handling of some platform-specific quirks that are required
to make it behave as closely as possible like open(3p) would, but for
most cases we just call the Windows-specific `_wopen()` function.

This function has a major downside though: it does not allow us to
specify the sharing mode. While there is `_wsopen()` that allows us to
pass sharing flags, those sharing flags are not the same `FILE_SHARE_*`
flags as `CreateFileW()` accepts. Instead, `_wsopen()` only allows
concurrent read- and write-access, but does not allow for concurrent
deletions. Unfortunately though, we have to allow concurrent deletions
if we want to have POSIX-style atomic renames on top of an existing file
that has open file handles.

Implement a new function that emulates open(3p) for existing files via
`CreateFileW()` such that we can set the required sharing flags.

While we have the same issue when calling open(3p) with `O_CREAT`,
implementing that mode would be more complex due to the required
permission handling. Furthermore, atomic updates via renames typically
write to exclusive lockfile and then perform the rename, and thus we
don't have to handle the case where the locked path has been created
with `O_CREATE`. So while it would be nice to have proper POSIX
semantics in all paths, we instead aim for a minimum viable fix here.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2024-10-27 19:51:35 -04:00
Patrick Steinhardt
b0b65ec593 compat/mingw: share file handles created via CreateFileW()
Unless told otherwise, Windows will keep other processes from reading,
writing and deleting files when one has an open handle that was created
via `CreateFileW()`. This behaviour can be altered via `FILE_SHARE_*`
flags:

  - `FILE_SHARE_READ` allows a concurrent process to open the file for
    reading.

  - `FILE_SHARE_WRITE` allows a concurrent process to open the file for
    writing.

  - `FILE_SHARE_DELETE` allows a concurrent process to delete the file
    or to replace it via an atomic rename.

This sharing mechanism is quite important in the context of Git, as we
assume POSIX semantics all over the place. But there are two callsites
where we don't pass all three of these flags:

  - We don't set `FILE_SHARE_DELETE` when creating a file for appending
    via `mingw_open_append()`. This makes it impossible to delete the
    file from another process or to replace it via an atomic rename. The
    function was introduced via d641097589 (mingw: enable atomic
    O_APPEND, 2018-08-13) and has been using `FILE_SHARE_READ |
    FILE_SHARE_WRITE` since the inception. There aren't any indicators
    that the omission of `FILE_SHARE_DELETE` was intentional.

  - We don't set any sharing flags in `mingw_utime()`, which changes the
    access and modification of a file. This makes it impossible to
    perform any kind of operation on this file at all from another
    process. While we only open the file for a short amount of time to
    update its timestamps, this still opens us up for a race condition
    with another process.

    `mingw_utime()` was originally implemented via `_wopen()`, which
    doesn't give you full control over the sharing mode. Instead, it
    calls `_wsopen()` with `_SH_DENYNO`, which ultimately translates to
    `FILE_SHARE_READ | FILE_SHARE_WRITE`. It was then refactored via
    090a3085bc (t/helper/test-chmtime: update mingw to support chmtime
    on directories, 2022-03-02) to use `CreateFileW()`, but we stopped
    setting any sharing flags at all, which seems like an unintentional
    side effect. By restoring `FILE_SHARE_READ | FILE_SHARE_WRITE` we
    thus fix this and get back the old behaviour of `_wopen()`.

    The fact that we didn't set the equivalent of `FILE_SHARE_DELETE`
    can be explained, as well: neither `_wopen()` nor `_wsopen()` allow
    you to do so. So overall, it doesn't seem intentional that we didn't
    allow deletions here, either.

Adapt both of these callsites to pass all three sharing flags.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2024-10-27 19:51:35 -04:00
Sören Krecker
386d372031 mingw.c: Fix complier warnings for a 64 bit msvc
Remove some complier warnings from msvc in compat/mingw.c for value
truncation from 64 bit to 32 bit integers.

Compiling compat/mingw.c under a 64 bit version of msvc produces
warnings. An "int" is 32 bit, and ssize_t or size_t should be 64 bit
long. Prepare compat/vcbuild/include/unistd.h to have a 64 bit type
_ssize_t, when _WIN64 is defined and 32 bit otherwise.

Further down in this include file, as before, ssize_t is defined as
_ssize_t, if needed.

Use size_t instead of int for all variables that hold the result of
strlen() or wcslen() (which cannot be negative).

Use ssize_t to hold the return value of read().

Signed-off-by: Sören Krecker <soekkle@freenet.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2024-10-17 14:42:27 -04:00
Junio C Hamano
3eb6679959 Merge branch 'ps/environ-wo-the-repository'
Code clean-up.

* ps/environ-wo-the-repository: (21 commits)
  environment: stop storing "core.notesRef" globally
  environment: stop storing "core.warnAmbiguousRefs" globally
  environment: stop storing "core.preferSymlinkRefs" globally
  environment: stop storing "core.logAllRefUpdates" globally
  refs: stop modifying global `log_all_ref_updates` variable
  branch: stop modifying `log_all_ref_updates` variable
  repo-settings: track defaults close to `struct repo_settings`
  repo-settings: split out declarations into a standalone header
  environment: guard state depending on a repository
  environment: reorder header to split out `the_repository`-free section
  environment: move `set_git_dir()` and related into setup layer
  environment: make `get_git_namespace()` self-contained
  environment: move object database functions into object layer
  config: make dependency on repo in `read_early_config()` explicit
  config: document `read_early_config()` and `read_very_early_config()`
  environment: make `get_git_work_tree()` accept a repository
  environment: make `get_graft_file()` accept a repository
  environment: make `get_index_file()` accept a repository
  environment: make `get_object_directory()` accept a repository
  environment: make `get_git_common_dir()` accept a repository
  ...
2024-09-23 10:35:05 -07:00
Patrick Steinhardt
673af418d0 environment: guard state depending on a repository
In "environment.h" we have quite a lot of functions and variables that
either explicitly or implicitly depend on `the_repository`.

The implicit set of stateful declarations includes for example variables
which get populated when parsing a repository's Git configuration. This
set of variables is broken by design, as their state often depends on
the last repository config that has been parsed. So they may or may not
represent the state of `the_repository`.

Fixing that is quite a big undertaking, and later patches in this series
will demonstrate a solution for a first small set of those variables. So
for now, let's guard these with `USE_THE_REPOSITORY_VARIABLE` so that
callers are aware of the implicit dependency.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-12 10:15:42 -07:00
Jeff King
b652382d76 compat: mark unused parameters in win32/mingw functions
The compat/ directory contains many stub functions, wrappers, and so on
that have to conform to a specific interface, but don't necessarily need
to use all of their parameters. Let's mark them to avoid complaints from
-Wunused-parameter.

This was done mostly via guess-and-check with the Windows build in
GitHub CI. I also confirmed that the win+VS build is similarly happy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-28 09:51:18 -07:00
Johannes Schindelin
f1ed769a3b mingw(is_msys2_sh): handle forward slashes in the sh.exe path, too
Whether the full path to the MSYS2 Bash is specified using backslashes
or forward slashes, in either case the command-line arguments need to be
quoted in the MSYS2-specific manner instead of using regular Win32
command-line quoting rules.

In preparation for `prepare_shell_cmd()` to use the full path to
`sh.exe` (with forward slashes for consistency), let's teach the
`is_msys2_sh()` function about this; Otherwise 5580.4 'clone with
backslashed path' would fail once `prepare_shell_cmd()` uses the full
path instead of merely `sh`.

This patch relies on the just-introduced fix where `fspathcmp()` handles
backslashes and forward slashes as equivalent on Windows.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-07-13 16:23:37 -07:00
Junio C Hamano
424a13db64 Merge branch 'js/mingw-remove-unused-extern-decl'
An unused extern declaration for mingw has been removed to prevent
it from causing build failure.

* js/mingw-remove-unused-extern-decl:
  mingw: drop bogus (and unneeded) declaration of `_pgmptr`
2024-06-27 09:19:58 -07:00
Johannes Schindelin
3c295c87c2 mingw: drop bogus (and unneeded) declaration of _pgmptr
In 08809c09aa (mingw: add a helper function to attach GDB to the
current process, 2020-02-13), I added a declaration that was not needed.
Back then, that did not matter, but now that the declaration of that
symbol was changed in mingw-w64's headers, it causes the following
compile error:

      CC compat/mingw.o
  compat/mingw.c: In function 'open_in_gdb':
  compat/mingw.c:35:9: error: function declaration isn't a prototype [-Werror=strict-prototypes]
     35 |         extern char *_pgmptr;
        |         ^~~~~~
  In file included from C:/git-sdk-64/usr/src/git/build-installers/mingw64/lib/gcc/x86_64-w64-mingw32/14.1.0/include/mm_malloc.h:27,
                   from C:/git-sdk-64/usr/src/git/build-installers/mingw64/lib/gcc/x86_64-w64-mingw32/14.1.0/include/xmmintrin.h:34,
                   from C:/git-sdk-64/usr/src/git/build-installers/mingw64/lib/gcc/x86_64-w64-mingw32/14.1.0/include/immintrin.h:31,
                   from C:/git-sdk-64/usr/src/git/build-installers/mingw64/lib/gcc/x86_64-w64-mingw32/14.1.0/include/x86intrin.h:32,
                   from C:/git-sdk-64/usr/src/git/build-installers/mingw64/include/winnt.h:1658,
                   from C:/git-sdk-64/usr/src/git/build-installers/mingw64/include/minwindef.h:163,
                   from C:/git-sdk-64/usr/src/git/build-installers/mingw64/include/windef.h:9,
                   from C:/git-sdk-64/usr/src/git/build-installers/mingw64/include/windows.h:69,
                   from C:/git-sdk-64/usr/src/git/build-installers/mingw64/include/winsock2.h:23,
                   from compat/../git-compat-util.h:215,
                   from compat/mingw.c:1:
  compat/mingw.c:35:22: error: '__p__pgmptr' redeclared without dllimport attribute: previous dllimport ignored [-Werror=attributes]
     35 |         extern char *_pgmptr;
        |                      ^~~~~~~

Let's just drop the declaration and get rid of this compile error.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-20 10:59:42 -07:00
Patrick Steinhardt
e7b40195ae compat/win32: fix const-correctness with string constants
Adjust various places in our Win32 compatibility layer where we are not
assigning string constants to `const char *` variables.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-07 10:30:52 -07:00
Mike Hommey
395c130fd8 win32: fix building with NO_UNIX_SOCKETS
After 2406bf5f (Win32: detect unix socket support at runtime,
2024-04-03), it fails with:

compat/mingw.c:4160:5: error: no previous prototype for function 'mingw_have_unix_sockets' [-Werror,-Wmissing-prototypes]
   4160 | int mingw_have_unix_sockets(void)
        |     ^

because the prototype is behind `ifndef NO_UNIX_SOCKETS`.

Signed-off-by: Mike Hommey <mh@glandium.org>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-03 08:42:50 -07:00
Matthias Aßhauer
2406bf5fc5 Win32: detect unix socket support at runtime
Windows 10 build 17063 introduced support for unix sockets to Windows.
bb390b1 (git-compat-util: include declaration for unix sockets in
windows, 2021-09-14) introduced a way to build git with unix socket
support on Windows, but you still had to decide at build time which
Windows version the compiled executable was supposed to run on.

We can detect at runtime wether the operating system supports unix
sockets and act accordingly for all supported Windows versions.

This fixes https://github.com/git-for-windows/git/issues/3892

Signed-off-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-03 14:54:28 -07:00