Commit Graph

8 Commits

Author SHA1 Message Date
Johannes Schindelin
40b59862f1 Win32: teach fscache and dirent about symlinks
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>
2017-10-29 16:46:05 +01:00
Johannes Schindelin
3a855b23e3 Win32: support long paths
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]

Thanks-to: Martin W. Kirst <maki@bitkings.de>
Thanks-to: Doug Kelly <dougk.ff7@gmail.com>
Signed-off-by: Karsten Blees <blees@dcon.de>
Original-test-by: Andrey Rogozhnikov <rogozhnikov.andrey@gmail.com>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-29 16:45:38 +01:00
Karsten Blees
c46534ee6b Win32: Make the dirent implementation pluggable
Emulating the POSIX dirent API on Windows via FindFirstFile/FindNextFile is
pretty staightforward, however, most of the information provided in the
WIN32_FIND_DATA structure is thrown away in the process. A more
sophisticated implementation may cache this data, e.g. for later reuse in
calls to lstat.

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

Define a base DIR structure with pointers to readdir/closedir that match
the opendir implementation (i.e. similar to vtable pointers in OOP).
Define readdir/closedir so that they call the function pointers in the DIR
structure. This allows to choose the opendir implementation on a
call-by-call basis.

Move the fixed sized dirent.d_name buffer to the dirent-specific DIR
structure, as d_name may be implementation specific (e.g. a caching
implementation may just set d_name to point into the cache instead of
copying the entire file name string).

Signed-off-by: Karsten Blees <blees@dcon.de>
2017-10-29 16:45:37 +01:00
Karsten Blees
ad2106ac30 Win32: dirent.c: Move opendir down
Move opendir down in preparation for the next patch.

Signed-off-by: Karsten Blees <blees@dcon.de>
2017-10-29 16:45:37 +01:00
Karsten Blees
0217569bb2 Win32: Unicode file name support (dirent)
Changes opendir/readdir to use Windows Unicode APIs and convert between
UTF-8/UTF-16.

Removes parameter checks that are already covered by xutftowcs_path. This
changes detection of ENAMETOOLONG from MAX_PATH - 2 to MAX_PATH (matching
is_dir_empty in mingw.c). If name + "/*" or the resulting absolute path is
too long, FindFirstFile fails and errno is set through err_win_to_posix.

Increases the size of dirent.d_name to accommodate the full
WIN32_FIND_DATA.cFileName converted to UTF-8 (UTF-16 to UTF-8 conversion
may grow by factor three in the worst case).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-15 11:19:09 -07:00
Karsten Blees
d8890ce726 Win32 dirent: improve dirent implementation
Improve the dirent implementation by removing the relics that were once
necessary to plug into the now unused MinGW runtime, in preparation for
Unicode file name support.

Move FindFirstFile to opendir, and FindClose to closedir, with the
following implications:
- DIR.dd_name is no longer needed
- chdir(one); opendir(relative); chdir(two); readdir() works as expected
  (i.e. lists one/relative instead of two/relative)
- DIR.dd_handle is a valid handle for the entire lifetime of the DIR struct
- thus, all checks for dd_handle == INVALID_HANDLE_VALUE and dd_handle == 0
  have been removed
- the special case that the directory has been fully read (which was
  previously explicitly tracked with dd_handle == INVALID_HANDLE_VALUE &&
  dd_stat != 0) is now handled implicitly by the FindNextFile error
  handling code (if a client continues to call readdir after receiving
  NULL, FindNextFile will continue to fail with ERROR_NO_MORE_FILES, to
  the same effect)
- extracting dirent data from WIN32_FIND_DATA is needed in two places, so
  moved to its own method
- GetFileAttributes is no longer needed. The same information can be
  obtained from the FindFirstFile error code, which is ERROR_DIRECTORY if
  the name is NOT a directory (-> ENOTDIR), otherwise we can use
  err_win_to_posix (e.g. ERROR_PATH_NOT_FOUND -> ENOENT). The
  ERROR_DIRECTORY case could be fixed in err_win_to_posix, but this
  probably breaks other functionality.

Removes the ERROR_NO_MORE_FILES check after FindFirstFile (this was
fortunately a NOOP (searching for '*' always finds '.' and '..'),
otherwise the subsequent code would have copied data from an uninitialized
buffer).

Changes malloc to git support function xmalloc, so opendir will die() if
out of memory, rather than failing with ENOMEM and letting git work on
incomplete directory listings (error handling in dir.c is quite sparse).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-09 15:10:53 -07:00
Karsten Blees
a8248f4a8d Win32 dirent: clarify #include directives
Git-compat-util.h is two dirs up, and already includes <dirent.h> (which
is the same as "dirent.h" due to -Icompat/win32 in the Makefile).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-09 15:10:53 -07:00
Erik Faye-Lund
d1b6e6e015 win32: use our own dirent.h
The mingw-runtime implemenation of opendir, readdir and closedir
sets errno to 0 on success, something that POSIX explicitly
forbids. 3ba7a06 ("A loose object is not corrupt if it cannot be
read due to EMFILE") introduce a dependency on this behaviour,
leading to a broken "git clone" on Windows.

compat/mingw.c contains an implementation of readdir, and
compat/msvc.c contains implementations of opendir and closedir.

Move these to compat/win32/dirent.[ch], and change to our own DIR
structure at the same time.

This provides a generic Win32-implementation of opendir, readdir
and closedir which works on both MinGW and MSVC and does not reset
errno, and as a result git clone is working again on Windows.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-11-23 16:06:50 -08:00