Create trace2_initialize_clock() and call from main() to capture
process start time in isolation and before other sub-systems are
ready.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `xutftowcs_path` function canonicalizes absolute paths using GetFullPathNameW.
This canonicalization may change the length of the string (e.g. getting rid of \.\),
which breaks callers that pass the template string in a strbuf and expect the
length of the string to remain the same.
In my particular case, the tmp-objdir code is passing a strbuf to mkdtemp and is
breaking since the strbuf.len is no longer synchronized with strlen(strbuf.buf).
Signed-off-by: Neeraj K. Singh <neerajsi@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Previously, we did not install any handler for Ctrl+C, but now we really
want to because the MSYS2 runtime learned the trick to call the
ConsoleCtrlHandler when Ctrl+C was pressed.
With this, hitting Ctrl+C while `git log` is running will only terminate
the Git process, but not the pager. This finally matches the behavior on
Linux and on macOS.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The TerminateProcess() function does not actually leave the child
processes any chance to perform any cleanup operations. This is bad
insofar as Git itself expects its signal handlers to run.
A symptom is e.g. a left-behind .lock file that would not be left behind
if the same operation was run, say, on Linux.
To remedy this situation, we use an obscure trick: we inject a thread
into the process that needs to be killed and to let that thread run the
ExitProcess() function with the desired exit status. Thanks J Wyman for
describing this trick.
The advantage is that the ExitProcess() function lets the atexit
handlers run. While this is still different from what Git expects (i.e.
running a signal handler), in practice Git sets up signal handlers and
atexit handlers that call the same code to clean up after itself.
In case that the gentle method to terminate the process failed, we still
fall back to calling TerminateProcess(), but in that case we now also
make sure that processes spawned by the spawned process are terminated;
TerminateProcess() does not give the spawned process a chance to do so
itself.
Please note that this change only affects how Git for Windows tries to
terminate processes spawned by Git's own executables. Third-party
software that *calls* Git and wants to terminate it *still* need to make
sure to imitate this gentle method, otherwise this patch will not have
any effect.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
On Windows, symbolic links have a type: a "file symlink" must point at
a file, and a "directory symlink" must point at a directory. If the
type of symlink does not match its target, it doesn't work.
Git does not record the type of symlink in the index or in a tree. On
checkout it'll guess the type, which only works if the target exists
at the time the symlink is created. This may often not be the case,
for example when the link points at a directory inside a submodule.
By specifying `symlink=file` or `symlink=dir` the user can specify what
type of symlink Git should create, so Git doesn't have to rely on
unreliable heuristics.
Signed-off-by: Bert Belder <bertbelder@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
On Windows, symbolic links actually have a type depending on the target:
it can be a file or a directory.
In certain circumstances, this poses problems, e.g. when a symbolic link
is supposed to point into a submodule that is not checked out, so there
is no way for Git to auto-detect the type.
To help with that, we will add support over the course of the next
commits to specify that symlink type via the Git attributes. This
requires an index_state, though, something that Git for Windows'
`symlink()` replacement cannot know about because the function signature
is defined by the POSIX standard and not ours to change.
So let's introduce a helper function to create symbolic links that
*does* know about the index_state.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
BusyBox comes with a ton of applets ("applet" being the identical
concept to Git's "builtins"). And similar to Git's builtins, the applets
can be called via `busybox <command>`, or the BusyBox executable can be
copied/hard-linked to the command name.
The similarities do not end here. Just as with Git's builtins, it is
problematic that BusyBox' hard-linked applets cannot easily be put into
a .zip file: .zip archives have no concept of hard-links and therefore
would store identical copies (and also extract identical copies,
"inflating" the archive unnecessarily).
To counteract that issue, MinGit already ships without hard-linked
copies of the builtins, and the plan is to do the same with BusyBox'
applets: simply ship busybox.exe as single executable, without
hard-linked applets.
To accommodate that, Git is being taught by this commit a very special
trick, exploiting the fact that it is possible to call an executable
with a command-line whose argv[0] is different from the executable's
name: when `sh` is to be spawned, and no `sh` is found in the PATH, but
busybox.exe is, use that executable (with unchanged argv).
Likewise, if any executable to be spawned is not on the PATH, but
busybox.exe is found, parse the output of `busybox.exe --help` to find
out what applets are included, and if the command matches an included
applet name, use busybox.exe to execute it.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The main idea of this patch is that even if we have to look up the
absolute path of the script, if only the basename was specified as
argv[0], then we should use that basename on the command line, too, not
the absolute path.
This patch will also help with the upcoming patch where we automatically
substitute "sh ..." by "busybox sh ..." if "sh" is not in the PATH but
"busybox" is: we will do that by substituting the actual executable, but
still keep prepending "sh" to the command line.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
... even if they may look like them.
As looking up the target of the "symbolic link" (just to see whether it
starts with `/ContainerMappedDirectories/`) is pretty expensive, we
do it when we can be *really* sure that there is a possibility that this
might be the case.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: JiSeop Moon <zcube@zcube.kr>
In preparation for making this function a bit more complicated (to allow
for special-casing the `ContainerMappedDirectories` in Windows
containers, which look like a symbolic link, but are not), let's move it
out of the header.
Signed-off-by: JiSeop Moon <zcube@zcube.kr>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When creating directories via `safe_create_leading_directories()`, we
might encounter an already-existing directory which is not
readable by the current user. To handle that situation, Git's code calls
`stat()` to determine whether we're looking at a directory.
In such a case, `CreateFile()` will fail, though, no matter what, and
consequently `mingw_stat()` will fail, too. But POSIX semantics seem to
still allow `stat()` to go forward.
So let's call `mingw_lstat()` for the rescue if we fail to get a file
handle due to denied permission in `mingw_stat()`, and fill the stat
info that way.
We need to be careful to not allow this to go forward in case that we're
looking at a symbolic link: to resolve the link, we would still have to
create a file handle, and we just found out that we cannot. Therefore,
`stat()` still needs to fail with `EACCES` in that case.
This fixes https://github.com/git-for-windows/git/issues/2531.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
It is a known issue that a rename() can fail with an "Access denied"
error at times, when copying followed by deleting the original file
works. Let's just fall back to that behavior.
Signed-off-by: JiSeop Moon <zcube@zcube.kr>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
With Windows 10 Build 14972 in Developer Mode, a new flag is supported
by CreateSymbolicLink() to create symbolic links even when running
outside of an elevated session (which was previously required).
This new flag is called SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE and
has the numeric value 0x02.
Previous Windows 10 versions will not understand that flag and return an
ERROR_INVALID_PARAMETER, therefore we have to be careful to try passing
that flag only when the build number indicates that it is supported.
For more information about the new flag, see this blog post:
https://blogs.windows.com/buildingapps/2016/12/02/symlinks-windows-10/
This patch is loosely based on the patch submitted by Samuel D. Leslie
as https://github.com/git-for-windows/git/pull/1184.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This will come in handy in the next commit.
Signed-off-by: JiSeop Moon <zcube@zcube.kr>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Symlinks on Windows have a flag that indicates whether the target is a file
or a directory. Symlinks of wrong type simply don't work. This even affects
core Win32 APIs (e.g. DeleteFile() refuses to delete directory symlinks).
However, CreateFile() with FILE_FLAG_BACKUP_SEMANTICS doesn't seem to care.
Check the target type by first creating a tentative file symlink, opening
it, and checking the type of the resulting handle. If it is a directory,
recreate the symlink with the directory flag set.
It is possible to create symlinks before the target exists (or in case of
symlinks to symlinks: before the target type is known). If this happens,
create a tentative file symlink and postpone the directory decision: keep
a list of phantom symlinks to be processed whenever a new directory is
created in mingw_mkdir().
Limitations: This algorithm may fail if a link target changes from file to
directory or vice versa, or if the target directory is created in another
process.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Implement symlink() that always creates file symlinks. Fails with ENOSYS
if symlinks are disabled or unsupported.
Note: CreateSymbolicLinkW() was introduced with symlink support in Windows
Vista. For compatibility with Windows XP, we need to load it dynamically
and fail gracefully if it isnt's available.
Signed-off-by: Karsten Blees <blees@dcon.de>
This commit fixes mingw_lstat by computing the proper size for symlinks
according to POSIX. POSIX specifies that upon successful return from
lstat: "the value of the st_size member shall be set to the length of
the pathname contained in the symbolic link not including any
terminating null byte".
Prior to this commit the mingw_lstat function returned a fixed size of
4096. This caused problems in git repositories that were accessed by
git for Cygwin or git for WSL. For example, doing `git reset --hard`
using git for Windows would update the size of symlinks in the index
to be 4096; at a later time git for Cygwin or git for WSL would find
that symlinks have changed size during `git status`. Vice versa doing
`git reset --hard` in git for Cygwin or git for WSL would update the
size of symlinks in the index with the correct value, only for git for
Windows to find incorrectly at a later time that the size had changed.
Signed-off-by: Bill Zissimopoulos <billziss@navimatics.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Implement readlink() by reading NTFS reparse points. Works for symlinks
and directory junctions. If symlinks are disabled, fail with ENOSYS.
Signed-off-by: Karsten Blees <blees@dcon.de>
If symlinks are enabled, resolve all symlinks when changing directories,
as required by POSIX.
Note: Git's real_path() function bases its link resolution algorithm on
this property of chdir(). Unfortunately, the current directory on Windows
is limited to only MAX_PATH (260) characters. Therefore using symlinks and
long paths in combination may be problematic.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
MSVCRT's _wrename() cannot rename symlinks over existing files: it returns
success without doing anything. Newer MSVCR*.dll versions probably do not
have this problem: according to CRT sources, they just call MoveFileEx()
with the MOVEFILE_COPY_ALLOWED flag.
Get rid of _wrename() and call MoveFileEx() with proper error handling.
Signed-off-by: Karsten Blees <blees@dcon.de>
_wunlink() / DeleteFileW() refuses to delete symlinks to directories. If
_wunlink() fails with ERROR_ACCESS_DENIED, try _wrmdir() as well.
Signed-off-by: Karsten Blees <blees@dcon.de>
Symlinks on Windows don't work the same way as on Unix systems. E.g. there
are different types of symlinks for directories and files, creating
symlinks requires administrative privileges etc.
By default, disable symlink support on Windows. I.e. users explicitly have
to enable it with 'git config [--system|--global] core.symlinks true'.
The test suite ignores system / global config files. Allow testing *with*
symlink support by checking if native symlinks are enabled in MSys2 (via
'MSYS=winsymlinks:nativestrict').
Reminder: This would need to be changed if / when we find a way to run the
test suite in a non-MSys-based shell (e.g. dash).
Signed-off-by: Karsten Blees <blees@dcon.de>
The retry pattern is duplicated in three places. It also seems to be too
hard to use: mingw_unlink() and mingw_rmdir() duplicate the code to retry,
and both of them do so incompletely. They also do not restore errno if the
user answers 'no'.
Introduce a retry_ask_yes_no() helper function that handles retry with
small delay, asking the user, and restoring errno.
mingw_unlink: include _wchmod in the retry loop (which may fail if the
file is locked exclusively).
mingw_rmdir: include special error handling in the retry loop.
Signed-off-by: Karsten Blees <blees@dcon.de>
Git typically doesn't trust the stat.st_size member of symlinks (e.g. see
strbuf_readlink()). However, some functions take shortcuts if st_size is 0
(e.g. diff_populate_filespec()).
In mingw_lstat() and fscache_lstat(), make sure to return an adequate size.
The extra overhead of opening and reading the reparse point to calculate
the exact size is not necessary, as git doesn't rely on the value anyway.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Move S_IFLNK detection to file_attr_to_st_mode() and reuse it in fscache.
Implement DT_LNK detection in dirent.c and the fscache readdir version.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When obtaining lstat information for reparse points, we need to call
FindFirstFile() in addition to GetFileInformationEx() to obtain the type
of the reparse point (symlink, mount point etc.). However, currently there
is no error handling whatsoever if FindFirstFile() fails.
Call FindFirstFile() before modifying the stat *buf output parameter and
error out if the call fails.
Note: The FindFirstFile() return value includes all the data that we get
from GetFileAttributesEx(), so we could replace GetFileAttributesEx() with
FindFirstFile(). We don't do that because GetFileAttributesEx() is about
twice as fast for single files. I.e. we only pay the extra cost of calling
FindFirstFile() in the rare case that we encounter a reparse point.
Note: The indentation of the remaining reparse point code will be fixed in
the next patch.
Signed-off-by: Karsten Blees <blees@dcon.de>
With the new mingw_stat() implementation, do_lstat() is only called from
mingw_lstat() (with follow == 0). Remove the extra function and the old
mingw_stat()-specific (follow == 1) logic.
Signed-off-by: Karsten Blees <blees@dcon.de>
With respect to symlinks, the current stat() implementation is almost the
same as lstat(): except for the file type (st_mode & S_IFMT), it returns
information about the link rather than the target.
Implement stat by opening the file with as little permissions as possible
and calling GetFileInformationByHandle on it. This way, all link resoltion
is handled by the Windows file system layer.
If symlinks are disabled, use lstat() as before, but fail with ELOOP if a
symlink would have to be resolved.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
GetFileAttributes cannot handle paths with trailing dir separator. The
current [l]stat implementation calls GetFileAttributes twice if the path
has trailing slashes (first with the original path passed to [l]stat, and
and a second time with a path copy with trailing '/' removed).
With Unicode conversion, we get the length of the path for free and also
have a (wide char) buffer that can be modified.
Remove trailing directory separators before calling the Win32 API.
Signed-off-by: Karsten Blees <blees@dcon.de>
Windows paths are typically limited to MAX_PATH = 260 characters, even
though the underlying NTFS file system supports paths up to 32,767 chars.
This limitation is also evident in Windows Explorer, cmd.exe and many
other applications (including IDEs).
Particularly annoying is that most Windows APIs return bogus error codes
if a relative path only barely exceeds MAX_PATH in conjunction with the
current directory, e.g. ERROR_PATH_NOT_FOUND / ENOENT instead of the
infinitely more helpful ERROR_FILENAME_EXCED_RANGE / ENAMETOOLONG.
Many Windows wide char APIs support longer than MAX_PATH paths through the
file namespace prefix ('\\?\' or '\\?\UNC\') followed by an absolute path.
Notable exceptions include functions dealing with executables and the
current directory (CreateProcess, LoadLibrary, Get/SetCurrentDirectory) as
well as the entire shell API (ShellExecute, SHGetSpecialFolderPath...).
Introduce a handle_long_path function to check the length of a specified
path properly (and fail with ENAMETOOLONG), and to optionally expand long
paths using the '\\?\' file namespace prefix. Short paths will not be
modified, so we don't need to worry about device names (NUL, CON, AUX).
Contrary to MSDN docs, the GetFullPathNameW function doesn't seem to be
limited to MAX_PATH (at least not on Win7), so we can use it to do the
heavy lifting of the conversion (translate '/' to '\', eliminate '.' and
'..', and make an absolute path).
Add long path error checking to xutftowcs_path for APIs with hard MAX_PATH
limit.
Add a new MAX_LONG_PATH constant and xutftowcs_long_path function for APIs
that support long paths.
While improved error checking is always active, long paths support must be
explicitly enabled via 'core.longpaths' option. This is to prevent end
users to shoot themselves in the foot by checking out files that Windows
Explorer, cmd/bash or their favorite IDE cannot handle.
Test suite:
Test the case is when the full pathname length of a dir is close
to 260 (MAX_PATH).
Bug report and an original reproducer by Andrey Rogozhnikov:
https://github.com/msysgit/git/pull/122#issuecomment-43604199
[jes: adjusted test number to avoid conflicts, added support for
chdir(), etc]
Thanks-to: Martin W. Kirst <maki@bitkings.de>
Thanks-to: Doug Kelly <dougk.ff7@gmail.com>
Original-test-by: Andrey Rogozhnikov <rogozhnikov.andrey@gmail.com>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When FSCache is active, we can cache the reparse tag and use it directly
to determine whether a path refers to an NTFS junction, without any
additional, costly I/O.
Note: this change only makes a difference with the next commit, which
will make use of the FSCache in `git clean` (contingent on
`core.fscache` set, of course).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
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>
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>
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>
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>
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.
Jeff Hostetler
Victoria Dye
Johannes Schindelin
Neeraj K. Singh
Bert Belder
JiSeop Moon
Karsten Blees
Bill Zissimopoulos
Ben Peart
Derrick Stolee