From e90c5bc2cd420acc7b9f762b2bf6e7497b2c2b8e Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Mon, 11 May 2015 19:54:23 +0200 Subject: [PATCH 01/21] strbuf_readlink: don't call readlink twice if hint is the exact link size strbuf_readlink() calls readlink() twice if the hint argument specifies the exact size of the link target (e.g. by passing stat.st_size as returned by lstat()). This is necessary because 'readlink(..., hint) == hint' could mean that the buffer was too small. Use hint + 1 as buffer size to prevent this. Signed-off-by: Karsten Blees --- strbuf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/strbuf.c b/strbuf.c index f3bd5719c6..3a847f5ca4 100644 --- a/strbuf.c +++ b/strbuf.c @@ -420,12 +420,12 @@ int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) while (hint < STRBUF_MAXLINK) { int len; - strbuf_grow(sb, hint); - len = readlink(path, sb->buf, hint); + strbuf_grow(sb, hint + 1); + len = readlink(path, sb->buf, hint + 1); if (len < 0) { if (errno != ERANGE) break; - } else if (len < hint) { + } else if (len <= hint) { strbuf_setlen(sb, len); return 0; } From e1fcdf60073df218b0ff5ae38f84e204375f163a Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Mon, 11 May 2015 22:15:40 +0200 Subject: [PATCH 02/21] strbuf_readlink: support link targets that exceed PATH_MAX strbuf_readlink() refuses to read link targets that exceed PATH_MAX (even if a sufficient size was specified by the caller). As some platforms support longer paths, remove this restriction (similar to strbuf_getcwd()). Signed-off-by: Karsten Blees --- strbuf.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/strbuf.c b/strbuf.c index 3a847f5ca4..989144b7bd 100644 --- a/strbuf.c +++ b/strbuf.c @@ -408,8 +408,6 @@ ssize_t strbuf_write(struct strbuf *sb, FILE *f) } -#define STRBUF_MAXLINK (2*PATH_MAX) - int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) { size_t oldalloc = sb->alloc; @@ -417,7 +415,7 @@ int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) if (hint < 32) hint = 32; - while (hint < STRBUF_MAXLINK) { + for (;; hint *= 2) { int len; strbuf_grow(sb, hint + 1); @@ -429,9 +427,6 @@ int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) strbuf_setlen(sb, len); return 0; } - - /* .. the buffer was too small - try again */ - hint *= 2; } if (oldalloc == 0) strbuf_release(sb); From b8555433c03d9191c6f68538d4ca777b7499e640 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Mon, 11 May 2015 19:58:14 +0200 Subject: [PATCH 03/21] lockfile.c: use is_dir_sep() instead of hardcoded '/' checks Signed-off-by: Karsten Blees --- lockfile.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lockfile.c b/lockfile.c index 9268cdf325..65d6d8cd64 100644 --- a/lockfile.c +++ b/lockfile.c @@ -17,14 +17,14 @@ static void trim_last_path_component(struct strbuf *path) int i = path->len; /* back up past trailing slashes, if any */ - while (i && path->buf[i - 1] == '/') + while (i && is_dir_sep(path->buf[i - 1])) i--; /* * then go backwards until a slash, or the beginning of the * string */ - while (i && path->buf[i - 1] != '/') + while (i && !is_dir_sep(path->buf[i - 1])) i--; strbuf_setlen(path, i); From 5f701da4d1cffaaacb095c694d7dbc6e14a13d4e Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 12 May 2015 11:09:01 +0200 Subject: [PATCH 04/21] Win32: don't call GetFileAttributes twice in mingw_lstat() 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 --- compat/mingw.c | 48 ++++++++++++------------------------------------ 1 file changed, 12 insertions(+), 36 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 79666ab33d..b96c23afd0 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -565,9 +565,18 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf) { WIN32_FILE_ATTRIBUTE_DATA fdata; wchar_t wfilename[MAX_LONG_PATH]; - if (xutftowcs_long_path(wfilename, file_name) < 0) + int wlen = xutftowcs_long_path(wfilename, file_name); + if (wlen < 0) return -1; + /* strip trailing '/', or GetFileAttributes will fail */ + while (wlen && is_dir_sep(wfilename[wlen - 1])) + wfilename[--wlen] = 0; + if (!wlen) { + errno = ENOENT; + return -1; + } + if (GetFileAttributesExW(wfilename, GetFileExInfoStandard, &fdata)) { buf->st_ino = 0; buf->st_gid = 0; @@ -627,48 +636,15 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf) return -1; } -/* We provide our own lstat/fstat functions, since the provided - * lstat/fstat functions are so slow. These stat functions are - * tailored for Git's usage (read: fast), and are not meant to be - * complete. Note that Git stat()s are redirected to mingw_lstat() - * too, since Windows doesn't really handle symlinks that well. - */ -static int do_stat_internal(int follow, const char *file_name, struct stat *buf) -{ - int namelen; - char alt_name[MAX_LONG_PATH]; - - if (!do_lstat(follow, file_name, buf)) - return 0; - - /* if file_name ended in a '/', Windows returned ENOENT; - * try again without trailing slashes - */ - if (errno != ENOENT) - return -1; - - namelen = strlen(file_name); - if (namelen && file_name[namelen-1] != '/') - return -1; - while (namelen && file_name[namelen-1] == '/') - --namelen; - if (!namelen || namelen >= MAX_LONG_PATH) - return -1; - - memcpy(alt_name, file_name, namelen); - alt_name[namelen] = 0; - return do_lstat(follow, alt_name, buf); -} - int (*lstat)(const char *file_name, struct stat *buf) = mingw_lstat; int mingw_lstat(const char *file_name, struct stat *buf) { - return do_stat_internal(0, file_name, buf); + return do_lstat(0, file_name, buf); } int mingw_stat(const char *file_name, struct stat *buf) { - return do_stat_internal(1, file_name, buf); + return do_lstat(1, file_name, buf); } int mingw_fstat(int fd, struct stat *buf) From 5aad51e34dc9861dea6ba7995fdcc12fb0ce50e8 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sat, 16 May 2015 01:18:14 +0200 Subject: [PATCH 05/21] Win32: implement stat() with symlink support 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 --- compat/mingw.c | 64 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 48 insertions(+), 16 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index b96c23afd0..513da4e0eb 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -642,16 +642,60 @@ int mingw_lstat(const char *file_name, struct stat *buf) { return do_lstat(0, file_name, buf); } + +static int get_file_info_by_handle(HANDLE hnd, struct stat *buf) +{ + BY_HANDLE_FILE_INFORMATION fdata; + if (!GetFileInformationByHandle(hnd, &fdata)) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + buf->st_ino = 0; + buf->st_dev = buf->st_rdev = 0; /* not used by Git */ + buf->st_gid = buf->st_uid = 0; + buf->st_nlink = 1; + buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes); + buf->st_size = fdata.nFileSizeLow | (((off_t) fdata.nFileSizeHigh) << 32); + buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime)); + buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime)); + buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime)); + return 0; +} + int mingw_stat(const char *file_name, struct stat *buf) { - return do_lstat(1, file_name, buf); + wchar_t wfile_name[MAX_LONG_PATH]; + HANDLE hnd; + int result; + + /* if symlinks are disabled, use lstat() (without following links) */ + if (!has_symlinks) { + result = lstat(file_name, buf); + if (!result && S_ISLNK(buf->st_mode)) { + errno = ELOOP; + return -1; + } + return result; + } + + /* otherwise just open the file and let Windows resolve the links */ + if (xutftowcs_long_path(wfile_name, file_name) < 0) + return -1; + hnd = CreateFileW(wfile_name, 0, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, + OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); + if (hnd == INVALID_HANDLE_VALUE) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + result = get_file_info_by_handle(hnd, buf); + CloseHandle(hnd); + return result; } int mingw_fstat(int fd, struct stat *buf) { HANDLE fh = (HANDLE)_get_osfhandle(fd); - BY_HANDLE_FILE_INFORMATION fdata; - if (fh == INVALID_HANDLE_VALUE) { errno = EBADF; return -1; @@ -660,20 +704,8 @@ int mingw_fstat(int fd, struct stat *buf) if (GetFileType(fh) != FILE_TYPE_DISK) return _fstati64(fd, buf); - if (GetFileInformationByHandle(fh, &fdata)) { - buf->st_ino = 0; - buf->st_gid = 0; - buf->st_uid = 0; - buf->st_nlink = 1; - buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes); - buf->st_size = fdata.nFileSizeLow | - (((off_t)fdata.nFileSizeHigh)<<32); - buf->st_dev = buf->st_rdev = 0; /* not used by Git */ - buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime)); - buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime)); - buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime)); + if (!get_file_info_by_handle(fh, buf)) return 0; - } errno = EBADF; return -1; } From 106e6401a617ccf0867e0b8dacbbf36c141bea0f Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 12 May 2015 00:58:39 +0200 Subject: [PATCH 06/21] Win32: remove separate do_lstat() function 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 --- compat/mingw.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 513da4e0eb..3d2164cde8 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -554,14 +554,7 @@ static int has_valid_directory_prefix(wchar_t *wfilename) return 1; } -/* We keep the do_lstat code in a separate function to avoid recursion. - * When a path ends with a slash, the stat will fail with ENOENT. In - * this case, we strip the trailing slashes and stat again. - * - * If follow is true then act like stat() and report on the link - * target. Otherwise report on the link itself. - */ -static int do_lstat(int follow, const char *file_name, struct stat *buf) +int mingw_lstat(const char *file_name, struct stat *buf) { WIN32_FILE_ATTRIBUTE_DATA fdata; wchar_t wfilename[MAX_LONG_PATH]; @@ -595,13 +588,7 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf) if (handle != INVALID_HANDLE_VALUE) { if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) && (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) { - if (follow) { - char buffer[MAXIMUM_REPARSE_DATA_BUFFER_SIZE]; - buf->st_size = readlink(file_name, buffer, MAXIMUM_REPARSE_DATA_BUFFER_SIZE); - } else { - buf->st_mode = S_IFLNK; - } - buf->st_mode |= S_IREAD; + buf->st_mode = S_IFLNK | S_IREAD; if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) buf->st_mode |= S_IWRITE; } @@ -638,11 +625,6 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf) int (*lstat)(const char *file_name, struct stat *buf) = mingw_lstat; -int mingw_lstat(const char *file_name, struct stat *buf) -{ - return do_lstat(0, file_name, buf); -} - static int get_file_info_by_handle(HANDLE hnd, struct stat *buf) { BY_HANDLE_FILE_INFORMATION fdata; From 4361fd521751d0b3387f698b37f2795acc250a2a Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 00:17:56 +0200 Subject: [PATCH 07/21] Win32: let mingw_lstat() error early upon problems with reparse points 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 --- compat/mingw.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 3d2164cde8..197cc6ad6d 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -557,6 +557,7 @@ static int has_valid_directory_prefix(wchar_t *wfilename) int mingw_lstat(const char *file_name, struct stat *buf) { WIN32_FILE_ATTRIBUTE_DATA fdata; + WIN32_FIND_DATAW findbuf; wchar_t wfilename[MAX_LONG_PATH]; int wlen = xutftowcs_long_path(wfilename, file_name); if (wlen < 0) @@ -571,6 +572,13 @@ int mingw_lstat(const char *file_name, struct stat *buf) } if (GetFileAttributesExW(wfilename, GetFileExInfoStandard, &fdata)) { + /* for reparse points, use FindFirstFile to get the reparse tag */ + if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { + HANDLE handle = FindFirstFileW(wfilename, &findbuf); + if (handle == INVALID_HANDLE_VALUE) + goto error; + FindClose(handle); + } buf->st_ino = 0; buf->st_gid = 0; buf->st_uid = 0; @@ -583,20 +591,16 @@ int mingw_lstat(const char *file_name, struct stat *buf) buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime)); buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime)); if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { - WIN32_FIND_DATAW findbuf; - HANDLE handle = FindFirstFileW(wfilename, &findbuf); - if (handle != INVALID_HANDLE_VALUE) { if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) && (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) { buf->st_mode = S_IFLNK | S_IREAD; if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) buf->st_mode |= S_IWRITE; } - FindClose(handle); - } } return 0; } +error: switch (GetLastError()) { case ERROR_ACCESS_DENIED: case ERROR_SHARING_VIOLATION: From 8a01496707ba26081a2d6b5fe5bdcd85fb8dfd8c Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 12 May 2015 01:59:19 +0200 Subject: [PATCH 08/21] 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 --- compat/mingw.c | 13 +++---------- compat/win32.h | 6 ++++-- compat/win32/dirent.c | 5 ++++- compat/win32/fscache.c | 6 ++++-- 4 files changed, 15 insertions(+), 15 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 197cc6ad6d..f8a4a9ac40 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -583,21 +583,14 @@ int mingw_lstat(const char *file_name, struct stat *buf) buf->st_gid = 0; buf->st_uid = 0; buf->st_nlink = 1; - buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes); + buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, + findbuf.dwReserved0); buf->st_size = fdata.nFileSizeLow | (((off_t)fdata.nFileSizeHigh)<<32); buf->st_dev = buf->st_rdev = 0; /* not used by Git */ buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime)); buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime)); buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime)); - if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { - if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) && - (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) { - buf->st_mode = S_IFLNK | S_IREAD; - if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) - buf->st_mode |= S_IWRITE; - } - } return 0; } error: @@ -640,7 +633,7 @@ static int get_file_info_by_handle(HANDLE hnd, struct stat *buf) buf->st_dev = buf->st_rdev = 0; /* not used by Git */ buf->st_gid = buf->st_uid = 0; buf->st_nlink = 1; - buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes); + buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, 0); buf->st_size = fdata.nFileSizeLow | (((off_t) fdata.nFileSizeHigh) << 32); buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime)); buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime)); diff --git a/compat/win32.h b/compat/win32.h index a97e880757..671bcc81f9 100644 --- a/compat/win32.h +++ b/compat/win32.h @@ -6,10 +6,12 @@ #include #endif -static inline int file_attr_to_st_mode (DWORD attr) +static inline int file_attr_to_st_mode (DWORD attr, DWORD tag) { int fMode = S_IREAD; - if (attr & FILE_ATTRIBUTE_DIRECTORY) + if ((attr & FILE_ATTRIBUTE_REPARSE_POINT) && tag == IO_REPARSE_TAG_SYMLINK) + fMode |= S_IFLNK; + else if (attr & FILE_ATTRIBUTE_DIRECTORY) fMode |= S_IFDIR; else fMode |= S_IFREG; diff --git a/compat/win32/dirent.c b/compat/win32/dirent.c index b3bd8d7af7..8c654d722b 100644 --- a/compat/win32/dirent.c +++ b/compat/win32/dirent.c @@ -16,7 +16,10 @@ static inline void finddata2dirent(struct dirent *ent, WIN32_FIND_DATAW *fdata) xwcstoutf(ent->d_name, fdata->cFileName, MAX_PATH * 3); /* Set file type, based on WIN32_FIND_DATA */ - if (fdata->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) + if ((fdata->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) + && fdata->dwReserved0 == IO_REPARSE_TAG_SYMLINK) + ent->d_type = DT_LNK; + else if (fdata->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ent->d_type = DT_DIR; else ent->d_type = DT_REG; diff --git a/compat/win32/fscache.c b/compat/win32/fscache.c index 63d522f49a..cda7b835aa 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -147,7 +147,8 @@ static struct fsentry *fseentry_create_entry(struct fsentry *list, fse = fsentry_alloc(list, buf, len); - fse->st_mode = file_attr_to_st_mode(fdata->dwFileAttributes); + fse->st_mode = file_attr_to_st_mode(fdata->dwFileAttributes, + fdata->dwReserved0); fse->st_size = (((off64_t) (fdata->nFileSizeHigh)) << 32) | fdata->nFileSizeLow; fse->st_atime = filetime_to_time_t(&(fdata->ftLastAccessTime)); @@ -456,7 +457,8 @@ static struct dirent *fscache_readdir(DIR *base_dir) if (!next) return NULL; dir->pfsentry = next; - dir->dirent.d_type = S_ISDIR(next->st_mode) ? DT_DIR : DT_REG; + dir->dirent.d_type = S_ISREG(next->st_mode) ? DT_REG : + S_ISDIR(next->st_mode) ? DT_DIR : DT_LNK; dir->dirent.d_name = (char*) next->name; return &(dir->dirent); } From b09e9abd19e984f2f4d0153ff68636c36e1b85ae Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sat, 16 May 2015 01:11:37 +0200 Subject: [PATCH 09/21] Win32: lstat(): return adequate stat.st_size for symlinks 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 --- compat/mingw.c | 4 ++-- compat/win32/fscache.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index f8a4a9ac40..2118e61ccf 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -585,8 +585,8 @@ int mingw_lstat(const char *file_name, struct stat *buf) buf->st_nlink = 1; buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, findbuf.dwReserved0); - buf->st_size = fdata.nFileSizeLow | - (((off_t)fdata.nFileSizeHigh)<<32); + buf->st_size = S_ISLNK(buf->st_mode) ? MAX_LONG_PATH : + fdata.nFileSizeLow | (((off_t) fdata.nFileSizeHigh) << 32); buf->st_dev = buf->st_rdev = 0; /* not used by Git */ buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime)); buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime)); diff --git a/compat/win32/fscache.c b/compat/win32/fscache.c index cda7b835aa..d23d3a4a27 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -149,8 +149,8 @@ static struct fsentry *fseentry_create_entry(struct fsentry *list, fse->st_mode = file_attr_to_st_mode(fdata->dwFileAttributes, fdata->dwReserved0); - fse->st_size = (((off64_t) (fdata->nFileSizeHigh)) << 32) - | fdata->nFileSizeLow; + fse->st_size = S_ISLNK(fse->st_mode) ? MAX_LONG_PATH : + fdata->nFileSizeLow | (((off_t) fdata->nFileSizeHigh) << 32); fse->st_atime = filetime_to_time_t(&(fdata->ftLastAccessTime)); fse->st_mtime = filetime_to_time_t(&(fdata->ftLastWriteTime)); fse->st_ctime = filetime_to_time_t(&(fdata->ftCreationTime)); From 00f0f478cf37fdfeea25d9db1d17dbdd09fedf59 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Mon, 25 Aug 2014 21:58:44 +0200 Subject: [PATCH 10/21] Win32: simplify loading of DLL functions Dynamic loading of DLL functions is duplicated in several places. Add a set of macros to simplify the process. Signed-off-by: Karsten Blees --- compat/mingw.c | 20 +++++++------------- compat/win32.h | 38 ++++++++++++++++++++++++++++++++++++++ compat/winansi.c | 14 +++++--------- 3 files changed, 50 insertions(+), 22 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 2118e61ccf..82b85c62a5 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -1978,24 +1978,18 @@ int mingw_raise(int sig) int link(const char *oldpath, const char *newpath) { - typedef BOOL (WINAPI *T)(LPCWSTR, LPCWSTR, LPSECURITY_ATTRIBUTES); - static T create_hard_link = NULL; + DECLARE_PROC_ADDR(kernel32.dll, BOOL, CreateHardLinkW, + LPCWSTR, LPCWSTR, LPSECURITY_ATTRIBUTES); wchar_t woldpath[MAX_LONG_PATH], wnewpath[MAX_LONG_PATH]; + + if (!INIT_PROC_ADDR(CreateHardLinkW)) + return -1; + if (xutftowcs_long_path(woldpath, oldpath) < 0 || xutftowcs_long_path(wnewpath, newpath) < 0) return -1; - if (!create_hard_link) { - create_hard_link = (T) GetProcAddress( - GetModuleHandle("kernel32.dll"), "CreateHardLinkW"); - if (!create_hard_link) - create_hard_link = (T)-1; - } - if (create_hard_link == (T)-1) { - errno = ENOSYS; - return -1; - } - if (!create_hard_link(wnewpath, woldpath, NULL)) { + if (!CreateHardLinkW(wnewpath, woldpath, NULL)) { errno = err_win_to_posix(GetLastError()); return -1; } diff --git a/compat/win32.h b/compat/win32.h index 671bcc81f9..79a86ec6c9 100644 --- a/compat/win32.h +++ b/compat/win32.h @@ -40,4 +40,42 @@ static inline int get_file_attr(const char *fname, WIN32_FILE_ATTRIBUTE_DATA *fd } } +/* simplify loading of DLL functions */ + +struct proc_addr { + const char *const dll; + const char *const function; + FARPROC pfunction; + unsigned initialized : 1; +}; + +/* Declares a function to be loaded dynamically from a DLL. */ +#define DECLARE_PROC_ADDR(dll, rettype, function, ...) \ + static struct proc_addr proc_addr_##function = \ + { #dll, #function, NULL, 0 }; \ + static rettype (WINAPI *function)(__VA_ARGS__) + +/* + * Loads a function from a DLL (once-only). + * Returns non-NULL function pointer on success. + * Returns NULL + errno == ENOSYS on failure. + */ +#define INIT_PROC_ADDR(function) (function = get_proc_addr(&proc_addr_##function)) + +static inline void *get_proc_addr(struct proc_addr *proc) +{ + /* only do this once */ + if (!proc->initialized) { + HANDLE hnd; + proc->initialized = 1; + hnd = LoadLibraryA(proc->dll); + if (hnd) + proc->pfunction = GetProcAddress(hnd, proc->function); + } + /* set ENOSYS if DLL or function was not found */ + if (!proc->pfunction) + errno = ENOSYS; + return proc->pfunction; +} + #endif diff --git a/compat/winansi.c b/compat/winansi.c index 54af2c5cf0..a3b7208fd8 100644 --- a/compat/winansi.c +++ b/compat/winansi.c @@ -6,6 +6,7 @@ #include "../git-compat-util.h" #include #include +#include "win32.h" /* ANSI codes used by git: m, K @@ -35,26 +36,21 @@ typedef struct _CONSOLE_FONT_INFOEX { #endif #endif -typedef BOOL (WINAPI *PGETCURRENTCONSOLEFONTEX)(HANDLE, BOOL, - PCONSOLE_FONT_INFOEX); - static void warn_if_raster_font(void) { DWORD fontFamily = 0; - PGETCURRENTCONSOLEFONTEX pGetCurrentConsoleFontEx; + DECLARE_PROC_ADDR(kernel32.dll, BOOL, GetCurrentConsoleFontEx, + HANDLE, BOOL, PCONSOLE_FONT_INFOEX); /* don't bother if output was ascii only */ if (!non_ascii_used) return; /* GetCurrentConsoleFontEx is available since Vista */ - pGetCurrentConsoleFontEx = (PGETCURRENTCONSOLEFONTEX) GetProcAddress( - GetModuleHandle("kernel32.dll"), - "GetCurrentConsoleFontEx"); - if (pGetCurrentConsoleFontEx) { + if (INIT_PROC_ADDR(GetCurrentConsoleFontEx)) { CONSOLE_FONT_INFOEX cfi; cfi.cbSize = sizeof(cfi); - if (pGetCurrentConsoleFontEx(console, 0, &cfi)) + if (GetCurrentConsoleFontEx(console, 0, &cfi)) fontFamily = cfi.FontFamily; } else { /* pre-Vista: check default console font in registry */ From 9afdee12cf812554604e63bf504b70b4493fa544 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 19 May 2015 21:48:55 +0200 Subject: [PATCH 11/21] Win32: factor out retry logic 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 --- compat/mingw.c | 98 ++++++++++++++++++++++---------------------------- 1 file changed, 43 insertions(+), 55 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 82b85c62a5..093e460726 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -8,8 +8,6 @@ #define HCAST(type, handle) ((type)(intptr_t)handle) -static const int delay[] = { 0, 1, 10, 20, 40 }; - int err_win_to_posix(DWORD winerr) { int error = ENOSYS; @@ -172,15 +170,12 @@ static int read_yes_no_answer(void) return -1; } -static int ask_yes_no_if_possible(const char *format, ...) +static int ask_yes_no_if_possible(const char *format, va_list args) { char question[4096]; const char *retry_hook[] = { NULL, NULL, NULL }; - va_list args; - va_start(args, format); vsnprintf(question, sizeof(question), format, args); - va_end(args); if ((retry_hook[0] = mingw_getenv("GIT_ASK_YESNO"))) { retry_hook[1] = question; @@ -202,33 +197,48 @@ static int ask_yes_no_if_possible(const char *format, ...) } } +static int retry_ask_yes_no(int *tries, const char *format, ...) +{ + static const int delay[] = { 0, 1, 10, 20, 40 }; + va_list args; + int result, saved_errno = errno; + + if ((*tries) < ARRAY_SIZE(delay)) { + /* + * We assume that some other process had the file open at the wrong + * moment and retry. In order to give the other process a higher + * chance to complete its operation, we give up our time slice now. + * If we have to retry again, we do sleep a bit. + */ + Sleep(delay[*tries]); + (*tries)++; + return 1; + } + + va_start(args, format); + result = ask_yes_no_if_possible(format, args); + va_end(args); + errno = saved_errno; + return result; +} + int mingw_unlink(const char *pathname) { - int ret, tries = 0; + int tries = 0; wchar_t wpathname[MAX_LONG_PATH]; if (xutftowcs_long_path(wpathname, pathname) < 0) return -1; - /* read-only files cannot be removed */ - _wchmod(wpathname, 0666); - while ((ret = _wunlink(wpathname)) == -1 && tries < ARRAY_SIZE(delay)) { + do { + /* read-only files cannot be removed */ + _wchmod(wpathname, 0666); + if (!_wunlink(wpathname)) + return 0; if (!is_file_in_use_error(GetLastError())) break; - /* - * We assume that some other process had the source or - * destination file open at the wrong moment and retry. - * In order to give the other process a higher chance to - * complete its operation, we give up our time slice now. - * If we have to retry again, we do sleep a bit. - */ - Sleep(delay[tries]); - tries++; - } - while (ret == -1 && is_file_in_use_error(GetLastError()) && - ask_yes_no_if_possible("Unlink of file '%s' failed. " - "Should I try again?", pathname)) - ret = _wunlink(wpathname); - return ret; + } while (retry_ask_yes_no(&tries, "Unlink of file '%s' failed. " + "Should I try again?", pathname)); + return -1; } static int is_dir_empty(const wchar_t *wpath) @@ -255,12 +265,14 @@ static int is_dir_empty(const wchar_t *wpath) int mingw_rmdir(const char *pathname) { - int ret, tries = 0; + int tries = 0; wchar_t wpathname[MAX_LONG_PATH]; if (xutftowcs_long_path(wpathname, pathname) < 0) return -1; - while ((ret = _wrmdir(wpathname)) == -1 && tries < ARRAY_SIZE(delay)) { + do { + if (!_wrmdir(wpathname)) + return 0; if (!is_file_in_use_error(GetLastError())) errno = err_win_to_posix(GetLastError()); if (errno != EACCES) @@ -269,21 +281,9 @@ int mingw_rmdir(const char *pathname) errno = ENOTEMPTY; break; } - /* - * We assume that some other process had the source or - * destination file open at the wrong moment and retry. - * In order to give the other process a higher chance to - * complete its operation, we give up our time slice now. - * If we have to retry again, we do sleep a bit. - */ - Sleep(delay[tries]); - tries++; - } - while (ret == -1 && errno == EACCES && is_file_in_use_error(GetLastError()) && - ask_yes_no_if_possible("Deletion of directory '%s' failed. " - "Should I try again?", pathname)) - ret = _wrmdir(wpathname); - return ret; + } while (retry_ask_yes_no(&tries, "Deletion of directory '%s' failed. " + "Should I try again?", pathname)); + return -1; } static inline int needs_hiding(const char *path) @@ -1776,20 +1776,8 @@ repeat: SetFileAttributesW(wpnew, attrs); } } - if (tries < ARRAY_SIZE(delay) && gle == ERROR_ACCESS_DENIED) { - /* - * We assume that some other process had the source or - * destination file open at the wrong moment and retry. - * In order to give the other process a higher chance to - * complete its operation, we give up our time slice now. - * If we have to retry again, we do sleep a bit. - */ - Sleep(delay[tries]); - tries++; - goto repeat; - } if (gle == ERROR_ACCESS_DENIED && - ask_yes_no_if_possible("Rename from '%s' to '%s' failed. " + retry_ask_yes_no(&tries, "Rename from '%s' to '%s' failed. " "Should I try again?", pold, pnew)) goto repeat; From 1203a08038bf4ed8952a51b73656b4abc5cf1031 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:55:05 +0200 Subject: [PATCH 12/21] Win32: change default of 'core.symlinks' to false 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 --- compat/mingw.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index 093e460726..15fb66c0fd 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2199,6 +2199,15 @@ static void setup_windows_environment(void) if (!tmp && (tmp = getenv("USERPROFILE"))) setenv("HOME", tmp, 1); } + + /* + * Change 'core.symlinks' default to false, unless native symlinks are + * enabled in MSys2 (via 'MSYS=winsymlinks:nativestrict'). Thus we can + * run the test suite (which doesn't obey config files) with or without + * symlink support. + */ + if (!(tmp = getenv("MSYS")) || !strstr(tmp, "winsymlinks:nativestrict")) + has_symlinks = 0; } int handle_long_path(wchar_t *path, int len, int max_path, int expand) From ac0fbcc1c6d66c6231740de7ba43b30b36adf533 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sat, 16 May 2015 00:32:03 +0200 Subject: [PATCH 13/21] Win32: add symlink-specific error codes Signed-off-by: Karsten Blees --- compat/mingw.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index 15fb66c0fd..3f3abfbf97 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -70,6 +70,7 @@ int err_win_to_posix(DWORD winerr) case ERROR_INVALID_PARAMETER: error = EINVAL; break; case ERROR_INVALID_PASSWORD: error = EPERM; break; case ERROR_INVALID_PRIMARY_GROUP: error = EINVAL; break; + case ERROR_INVALID_REPARSE_DATA: error = EINVAL; break; case ERROR_INVALID_SIGNAL_NUMBER: error = EINVAL; break; case ERROR_INVALID_TARGET_HANDLE: error = EIO; break; case ERROR_INVALID_WORKSTATION: error = EACCES; break; @@ -84,6 +85,7 @@ int err_win_to_posix(DWORD winerr) case ERROR_NEGATIVE_SEEK: error = ESPIPE; break; case ERROR_NOACCESS: error = EFAULT; break; case ERROR_NONE_MAPPED: error = EINVAL; break; + case ERROR_NOT_A_REPARSE_POINT: error = EINVAL; break; case ERROR_NOT_ENOUGH_MEMORY: error = ENOMEM; break; case ERROR_NOT_READY: error = EAGAIN; break; case ERROR_NOT_SAME_DEVICE: error = EXDEV; break; @@ -104,6 +106,9 @@ int err_win_to_posix(DWORD winerr) case ERROR_PIPE_NOT_CONNECTED: error = EPIPE; break; case ERROR_PRIVILEGE_NOT_HELD: error = EACCES; break; case ERROR_READ_FAULT: error = EIO; break; + case ERROR_REPARSE_ATTRIBUTE_CONFLICT: error = EINVAL; break; + case ERROR_REPARSE_TAG_INVALID: error = EINVAL; break; + case ERROR_REPARSE_TAG_MISMATCH: error = EINVAL; break; case ERROR_SEEK: error = EIO; break; case ERROR_SEEK_ON_DEVICE: error = ESPIPE; break; case ERROR_SHARING_BUFFER_EXCEEDED: error = ENFILE; break; From b3b96ee3ec41669c4468bb2be931c4444ef58f2b Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:06:10 +0200 Subject: [PATCH 14/21] Win32: mingw_unlink: support symlinks to directories _wunlink() / DeleteFileW() refuses to delete symlinks to directories. If _wunlink() fails with ERROR_ACCESS_DENIED, try _wrmdir() as well. Signed-off-by: Karsten Blees --- compat/mingw.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index 3f3abfbf97..a1de7f17e1 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -241,6 +241,13 @@ int mingw_unlink(const char *pathname) return 0; if (!is_file_in_use_error(GetLastError())) break; + /* + * _wunlink() / DeleteFileW() for directory symlinks fails with + * ERROR_ACCESS_DENIED (EACCES), so try _wrmdir() as well. This is the + * same error we get if a file is in use (already checked above). + */ + if (!_wrmdir(wpathname)) + return 0; } while (retry_ask_yes_no(&tries, "Unlink of file '%s' failed. " "Should I try again?", pathname)); return -1; From a9178c8faace2cc51bf8c7f58f634b471e663d02 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 19 May 2015 22:42:48 +0200 Subject: [PATCH 15/21] Win32: mingw_rename: support renaming symlinks 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 --- compat/mingw.c | 39 +++++++++++++++++---------------------- 1 file changed, 17 insertions(+), 22 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index a1de7f17e1..af7143b8a1 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -1748,28 +1748,29 @@ int mingw_accept(int sockfd1, struct sockaddr *sa, socklen_t *sz) #undef rename int mingw_rename(const char *pold, const char *pnew) { - DWORD attrs, gle; + DWORD attrs = INVALID_FILE_ATTRIBUTES, gle; int tries = 0; wchar_t wpold[MAX_LONG_PATH], wpnew[MAX_LONG_PATH]; if (xutftowcs_long_path(wpold, pold) < 0 || xutftowcs_long_path(wpnew, pnew) < 0) return -1; - /* - * Try native rename() first to get errno right. - * It is based on MoveFile(), which cannot overwrite existing files. - */ - if (!_wrename(wpold, wpnew)) - return 0; - if (errno != EEXIST) - return -1; repeat: - if (MoveFileExW(wpold, wpnew, MOVEFILE_REPLACE_EXISTING)) + if (MoveFileExW(wpold, wpnew, + MOVEFILE_REPLACE_EXISTING | MOVEFILE_COPY_ALLOWED)) return 0; - /* TODO: translate more errors */ gle = GetLastError(); - if (gle == ERROR_ACCESS_DENIED && - (attrs = GetFileAttributesW(wpnew)) != INVALID_FILE_ATTRIBUTES) { + + /* revert file attributes on failure */ + if (attrs != INVALID_FILE_ATTRIBUTES) + SetFileAttributesW(wpnew, attrs); + + if (!is_file_in_use_error(gle)) { + errno = err_win_to_posix(gle); + return -1; + } + + if ((attrs = GetFileAttributesW(wpnew)) != INVALID_FILE_ATTRIBUTES) { if (attrs & FILE_ATTRIBUTE_DIRECTORY) { DWORD attrsold = GetFileAttributesW(wpold); if (attrsold == INVALID_FILE_ATTRIBUTES || @@ -1780,16 +1781,10 @@ repeat: return -1; } if ((attrs & FILE_ATTRIBUTE_READONLY) && - SetFileAttributesW(wpnew, attrs & ~FILE_ATTRIBUTE_READONLY)) { - if (MoveFileExW(wpold, wpnew, MOVEFILE_REPLACE_EXISTING)) - return 0; - gle = GetLastError(); - /* revert file attributes on failure */ - SetFileAttributesW(wpnew, attrs); - } + SetFileAttributesW(wpnew, attrs & ~FILE_ATTRIBUTE_READONLY)) + goto repeat; } - if (gle == ERROR_ACCESS_DENIED && - retry_ask_yes_no(&tries, "Rename from '%s' to '%s' failed. " + if (retry_ask_yes_no(&tries, "Rename from '%s' to '%s' failed. " "Should I try again?", pold, pnew)) goto repeat; From 934d10af06a87536e6a831367b2ba3c6ad15801b Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:17:31 +0200 Subject: [PATCH 16/21] Win32: mingw_chdir: change to symlink-resolved directory 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. Note: GetFinalPathNameByHandleW() was introduced with symlink support in Windows Vista. Thus, for compatibility with Windows XP, we need to load it dynamically and behave gracefully if it isnt's available. Signed-off-by: Karsten Blees --- compat/mingw.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index af7143b8a1..c6adb67f9c 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -227,6 +227,34 @@ static int retry_ask_yes_no(int *tries, const char *format, ...) return result; } +/* Normalizes NT paths as returned by some low-level APIs. */ +static wchar_t *normalize_ntpath(wchar_t *wbuf) +{ + int i; + /* fix absolute path prefixes */ + if (wbuf[0] == '\\') { + /* strip NT namespace prefixes */ + if (!wcsncmp(wbuf, L"\\??\\", 4) || + !wcsncmp(wbuf, L"\\\\?\\", 4)) + wbuf += 4; + else if (!wcsnicmp(wbuf, L"\\DosDevices\\", 12)) + wbuf += 12; + /* replace remaining '...UNC\' with '\\' */ + if (!wcsnicmp(wbuf, L"UNC\\", 4)) { + wbuf += 2; + *wbuf = '\\'; + } + } + /* convert backslashes to slashes */ + for (i = 0; wbuf[i]; i++) + if (wbuf[i] == '\\') + wbuf[i] = '/'; + /* remove potential trailing slashes */ + while (i && wbuf[i - 1] == '/') + wbuf[--i] = 0; + return wbuf; +} + int mingw_unlink(const char *pathname) { int tries = 0; @@ -517,10 +545,29 @@ static int current_directory_len = 0; int mingw_chdir(const char *dirname) { int result; + DECLARE_PROC_ADDR(kernel32.dll, DWORD, GetFinalPathNameByHandleW, + HANDLE, LPWSTR, DWORD, DWORD); wchar_t wdirname[MAX_LONG_PATH]; if (xutftowcs_long_path(wdirname, dirname) < 0) return -1; - result = _wchdir(wdirname); + + if (has_symlinks && INIT_PROC_ADDR(GetFinalPathNameByHandleW)) { + HANDLE hnd = CreateFileW(wdirname, 0, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, + OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); + if (hnd == INVALID_HANDLE_VALUE) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + if (!GetFinalPathNameByHandleW(hnd, wdirname, ARRAY_SIZE(wdirname), 0)) { + errno = err_win_to_posix(GetLastError()); + CloseHandle(hnd); + return -1; + } + CloseHandle(hnd); + } + + result = _wchdir(normalize_ntpath(wdirname)); current_directory_len = GetCurrentDirectoryW(0, NULL); return result; } From 883a9f6d39d4087a9b5075de093126d17195754a Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:24:41 +0200 Subject: [PATCH 17/21] Win32: implement readlink() 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 --- compat/mingw.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++ compat/mingw.h | 3 +- 2 files changed, 102 insertions(+), 2 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index c6adb67f9c..a37bd2bec3 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2,6 +2,7 @@ #include "win32.h" #include #include +#include #include "../strbuf.h" #include "../run-command.h" #include "../cache.h" @@ -2038,6 +2039,106 @@ int link(const char *oldpath, const char *newpath) return 0; } +#ifndef _WINNT_H +/* + * The REPARSE_DATA_BUFFER structure is defined in the Windows DDK (in + * ntifs.h) and in MSYS1's winnt.h (which defines _WINNT_H). So define + * it ourselves if we are on MSYS2 (whose winnt.h defines _WINNT_). + */ +typedef struct _REPARSE_DATA_BUFFER { + DWORD ReparseTag; + WORD ReparseDataLength; + WORD Reserved; + _ANONYMOUS_UNION union { + struct { + WORD SubstituteNameOffset; + WORD SubstituteNameLength; + WORD PrintNameOffset; + WORD PrintNameLength; + ULONG Flags; + WCHAR PathBuffer[1]; + } SymbolicLinkReparseBuffer; + struct { + WORD SubstituteNameOffset; + WORD SubstituteNameLength; + WORD PrintNameOffset; + WORD PrintNameLength; + WCHAR PathBuffer[1]; + } MountPointReparseBuffer; + struct { + BYTE DataBuffer[1]; + } GenericReparseBuffer; + } DUMMYUNIONNAME; +} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER; +#endif + +int readlink(const char *path, char *buf, size_t bufsiz) +{ + HANDLE handle; + WCHAR wpath[MAX_LONG_PATH], *wbuf; + REPARSE_DATA_BUFFER *b = alloca(MAXIMUM_REPARSE_DATA_BUFFER_SIZE); + DWORD dummy; + char tmpbuf[MAX_LONG_PATH]; + int len; + + /* fail if symlinks are disabled */ + if (!has_symlinks) { + errno = ENOSYS; + return -1; + } + + if (xutftowcs_long_path(wpath, path) < 0) + return -1; + + /* read reparse point data */ + handle = CreateFileW(wpath, 0, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, + OPEN_EXISTING, + FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT, NULL); + if (handle == INVALID_HANDLE_VALUE) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + if (!DeviceIoControl(handle, FSCTL_GET_REPARSE_POINT, NULL, 0, b, + MAXIMUM_REPARSE_DATA_BUFFER_SIZE, &dummy, NULL)) { + errno = err_win_to_posix(GetLastError()); + CloseHandle(handle); + return -1; + } + CloseHandle(handle); + + /* get target path for symlinks or mount points (aka 'junctions') */ + switch (b->ReparseTag) { + case IO_REPARSE_TAG_SYMLINK: + wbuf = (WCHAR*) (((char*) b->SymbolicLinkReparseBuffer.PathBuffer) + + b->SymbolicLinkReparseBuffer.SubstituteNameOffset); + *(WCHAR*) (((char*) wbuf) + + b->SymbolicLinkReparseBuffer.SubstituteNameLength) = 0; + break; + case IO_REPARSE_TAG_MOUNT_POINT: + wbuf = (WCHAR*) (((char*) b->MountPointReparseBuffer.PathBuffer) + + b->MountPointReparseBuffer.SubstituteNameOffset); + *(WCHAR*) (((char*) wbuf) + + b->MountPointReparseBuffer.SubstituteNameLength) = 0; + break; + default: + errno = EINVAL; + return -1; + } + + /* + * Adapt to strange readlink() API: Copy up to bufsiz *bytes*, potentially + * cutting off a UTF-8 sequence. Insufficient bufsize is *not* a failure + * condition. There is no conversion function that produces invalid UTF-8, + * so convert to a (hopefully large enough) temporary buffer, then memcpy + * the requested number of bytes (including '\0' for robustness). + */ + if ((len = xwcstoutf(tmpbuf, normalize_ntpath(wbuf), MAX_LONG_PATH)) < 0) + return -1; + memcpy(buf, tmpbuf, min(bufsiz, len + 1)); + return min(bufsiz, len); +} + pid_t waitpid(pid_t pid, int *status, int options) { HANDLE h = OpenProcess(SYNCHRONIZE | PROCESS_QUERY_INFORMATION, diff --git a/compat/mingw.h b/compat/mingw.h index 7166679779..270828f2d8 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -117,8 +117,6 @@ struct utsname { * trivial stubs */ -static inline int readlink(const char *path, char *buf, size_t bufsiz) -{ errno = ENOSYS; return -1; } static inline int symlink(const char *oldpath, const char *newpath) { errno = ENOSYS; return -1; } static inline int fchmod(int fildes, mode_t mode) @@ -212,6 +210,7 @@ int setitimer(int type, struct itimerval *in, struct itimerval *out); int sigaction(int sig, struct sigaction *in, struct sigaction *out); int link(const char *oldpath, const char *newpath); int uname(struct utsname *buf); +int readlink(const char *path, char *buf, size_t bufsiz); /* * replacements of existing functions From 43d3e06259c272fe036cc0c229d64e278e466717 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:32:03 +0200 Subject: [PATCH 18/21] Win32: implement basic symlink() functionality (file symlinks only) 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 --- compat/mingw.c | 31 +++++++++++++++++++++++++++++++ compat/mingw.h | 3 +-- 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index a37bd2bec3..da2b109235 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -228,6 +228,9 @@ static int retry_ask_yes_no(int *tries, const char *format, ...) return result; } + +DECLARE_PROC_ADDR(kernel32.dll, BOOL, CreateSymbolicLinkW, LPCWSTR, LPCWSTR, DWORD); + /* Normalizes NT paths as returned by some low-level APIs. */ static wchar_t *normalize_ntpath(wchar_t *wbuf) { @@ -2039,6 +2042,34 @@ int link(const char *oldpath, const char *newpath) return 0; } +int symlink(const char *target, const char *link) +{ + wchar_t wtarget[MAX_LONG_PATH], wlink[MAX_LONG_PATH]; + int len; + + /* fail if symlinks are disabled or API is not supported (WinXP) */ + if (!has_symlinks || !INIT_PROC_ADDR(CreateSymbolicLinkW)) { + errno = ENOSYS; + return -1; + } + + if ((len = xutftowcs_long_path(wtarget, target)) < 0 + || xutftowcs_long_path(wlink, link) < 0) + return -1; + + /* convert target dir separators to backslashes */ + while (len--) + if (wtarget[len] == '/') + wtarget[len] = '\\'; + + /* create file symlink */ + if (!CreateSymbolicLinkW(wlink, wtarget, 0)) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + return 0; +} + #ifndef _WINNT_H /* * The REPARSE_DATA_BUFFER structure is defined in the Windows DDK (in diff --git a/compat/mingw.h b/compat/mingw.h index 270828f2d8..b0a979440a 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -117,8 +117,6 @@ struct utsname { * trivial stubs */ -static inline int symlink(const char *oldpath, const char *newpath) -{ errno = ENOSYS; return -1; } static inline int fchmod(int fildes, mode_t mode) { errno = ENOSYS; return -1; } #ifndef __MINGW64_VERSION_MAJOR @@ -210,6 +208,7 @@ int setitimer(int type, struct itimerval *in, struct itimerval *out); int sigaction(int sig, struct sigaction *in, struct sigaction *out); int link(const char *oldpath, const char *newpath); int uname(struct utsname *buf); +int symlink(const char *target, const char *link); int readlink(const char *path, char *buf, size_t bufsiz); /* From 040ce290f457705f38f85e2d11394e6709c6adfd Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:48:35 +0200 Subject: [PATCH 19/21] Win32: symlink: add support for symlinks to directories 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 --- compat/mingw.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index da2b109235..331c74a2e0 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -231,6 +231,88 @@ static int retry_ask_yes_no(int *tries, const char *format, ...) DECLARE_PROC_ADDR(kernel32.dll, BOOL, CreateSymbolicLinkW, LPCWSTR, LPCWSTR, DWORD); +enum phantom_symlink_result { + PHANTOM_SYMLINK_RETRY, + PHANTOM_SYMLINK_DONE, + PHANTOM_SYMLINK_DIRECTORY +}; + +/* + * Changes a file symlink to a directory symlink if the target exists and is a + * directory. + */ +static enum phantom_symlink_result process_phantom_symlink( + const wchar_t *wtarget, const wchar_t *wlink) { + HANDLE hnd; + BY_HANDLE_FILE_INFORMATION fdata; + + /* check that wlink is still a file symlink */ + if ((GetFileAttributesW(wlink) + & (FILE_ATTRIBUTE_REPARSE_POINT | FILE_ATTRIBUTE_DIRECTORY)) + != FILE_ATTRIBUTE_REPARSE_POINT) + return PHANTOM_SYMLINK_DONE; + + /* let Windows resolve the link by opening it */ + hnd = CreateFileW(wlink, 0, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, + OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); + if (hnd == INVALID_HANDLE_VALUE) { + errno = err_win_to_posix(GetLastError()); + return PHANTOM_SYMLINK_RETRY; + } + + if (!GetFileInformationByHandle(hnd, &fdata)) { + errno = err_win_to_posix(GetLastError()); + CloseHandle(hnd); + return PHANTOM_SYMLINK_RETRY; + } + CloseHandle(hnd); + + /* if target exists and is a file, we're done */ + if (!(fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) + return PHANTOM_SYMLINK_DONE; + + /* otherwise recreate the symlink with directory flag */ + if (DeleteFileW(wlink) && CreateSymbolicLinkW(wlink, wtarget, 1)) + return PHANTOM_SYMLINK_DIRECTORY; + + errno = err_win_to_posix(GetLastError()); + return PHANTOM_SYMLINK_RETRY; +} + +/* keep track of newly created symlinks to non-existing targets */ +struct phantom_symlink_info { + struct phantom_symlink_info *next; + wchar_t *wlink; + wchar_t *wtarget; +}; + +static struct phantom_symlink_info *phantom_symlinks = NULL; +static CRITICAL_SECTION phantom_symlinks_cs; + +static void process_phantom_symlinks(void) +{ + struct phantom_symlink_info *current, **psi; + EnterCriticalSection(&phantom_symlinks_cs); + /* process phantom symlinks list */ + psi = &phantom_symlinks; + while ((current = *psi)) { + enum phantom_symlink_result result = process_phantom_symlink( + current->wtarget, current->wlink); + if (result == PHANTOM_SYMLINK_RETRY) { + psi = ¤t->next; + } else { + /* symlink was processed, remove from list */ + *psi = current->next; + free(current); + /* if symlink was a directory, start over */ + if (result == PHANTOM_SYMLINK_DIRECTORY) + psi = &phantom_symlinks; + } + } + LeaveCriticalSection(&phantom_symlinks_cs); +} + /* Normalizes NT paths as returned by some low-level APIs. */ static wchar_t *normalize_ntpath(wchar_t *wbuf) { @@ -383,6 +465,8 @@ int mingw_mkdir(const char *path, int mode) return -1; ret = _wmkdir(wpath); + if (!ret) + process_phantom_symlinks(); if (!ret && needs_hiding(path)) return set_hidden_flag(wpath, 1); return ret; @@ -2067,6 +2151,42 @@ int symlink(const char *target, const char *link) errno = err_win_to_posix(GetLastError()); return -1; } + + /* convert to directory symlink if target exists */ + switch (process_phantom_symlink(wtarget, wlink)) { + case PHANTOM_SYMLINK_RETRY: { + /* if target doesn't exist, add to phantom symlinks list */ + wchar_t wfullpath[MAX_LONG_PATH]; + struct phantom_symlink_info *psi; + + /* convert to absolute path to be independent of cwd */ + len = GetFullPathNameW(wlink, MAX_LONG_PATH, wfullpath, NULL); + if (!len || len >= MAX_LONG_PATH) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + + /* over-allocate and fill phantom_smlink_info structure */ + psi = xmalloc(sizeof(struct phantom_symlink_info) + + sizeof(wchar_t) * (len + wcslen(wtarget) + 2)); + psi->wlink = (wchar_t *)(psi + 1); + wcscpy(psi->wlink, wfullpath); + psi->wtarget = psi->wlink + len + 1; + wcscpy(psi->wtarget, wtarget); + + EnterCriticalSection(&phantom_symlinks_cs); + psi->next = phantom_symlinks; + phantom_symlinks = psi; + LeaveCriticalSection(&phantom_symlinks_cs); + break; + } + case PHANTOM_SYMLINK_DIRECTORY: + /* if we created a dir symlink, process other phantom symlinks */ + process_phantom_symlinks(); + break; + default: + break; + } return 0; } @@ -2551,6 +2671,7 @@ void mingw_startup(void) /* initialize critical section for waitpid pinfo_t list */ InitializeCriticalSection(&pinfo_cs); + InitializeCriticalSection(&phantom_symlinks_cs); /* set up default file mode and file modes for stdin/out/err */ _fmode = _O_BINARY; From d6894122f49cac07d27d050e65a7d93ca3102e41 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Fri, 19 Jun 2015 21:00:46 +0000 Subject: [PATCH 20/21] mingw: keep trailing slashes for _wchdir() and readlink() This is needed so that `_wchdir()` can be used with drive root directories, e.g. C:\ (`_wchdir("C:")` fails to switch the directory to the root directory). This fixes https://github.com/msysgit/git/issues/359 (in Git for Windows 2.x only, though). Likewise, `readlink()`'s semantics require a trailing slash for symbolic links pointing to directories. Otherwise all checked out symbolic links pointing to directories would be marked as modified even directly after a fresh clone. This fixes https://github.com/git-for-windows/git/issues/210 Signed-off-by: Johannes Schindelin --- compat/mingw.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 331c74a2e0..d7aefdc298 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -335,9 +335,6 @@ static wchar_t *normalize_ntpath(wchar_t *wbuf) for (i = 0; wbuf[i]; i++) if (wbuf[i] == '\\') wbuf[i] = '/'; - /* remove potential trailing slashes */ - while (i && wbuf[i - 1] == '/') - wbuf[--i] = 0; return wbuf; } From 6905984ec88717ab2009630b7058520307259c87 Mon Sep 17 00:00:00 2001 From: lchiocca Date: Mon, 22 Jun 2015 10:29:43 +0200 Subject: [PATCH 21/21] The stat() function should be independent of core.symlinks The contract for the stat() and lstat() function is: > stat(): stats the file pointed to by path and fills in buf. > lstat(): is identical to stat(), except that if path is a symbolic link, > then the link itself is stat-ed, not the file that it refers to. stat() should always return the statistics of the file or directory a symbolic link is pointing to. The lstat() function is used to get the stats for the symlink. Hence the check should not be there. Signed-off-by: Loris Chiocca --- compat/mingw.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index d7aefdc298..6df3c8a86e 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -791,17 +791,7 @@ int mingw_stat(const char *file_name, struct stat *buf) HANDLE hnd; int result; - /* if symlinks are disabled, use lstat() (without following links) */ - if (!has_symlinks) { - result = lstat(file_name, buf); - if (!result && S_ISLNK(buf->st_mode)) { - errno = ELOOP; - return -1; - } - return result; - } - - /* otherwise just open the file and let Windows resolve the links */ + /* open the file and let Windows resolve the links */ if (xutftowcs_long_path(wfile_name, file_name) < 0) return -1; hnd = CreateFileW(wfile_name, 0,