From a4a9549421d3d4417cb1d6629b6dbe4605a10e61 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 00:17:56 +0200 Subject: [PATCH] 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 b19005c0e4bf83..d4aad9d49eb60d 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -935,6 +935,7 @@ 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 = { 0 }; wchar_t wfilename[MAX_LONG_PATH]; int wlen = xutftowcs_long_path(wfilename, file_name); if (wlen < 0) @@ -949,6 +950,13 @@ 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; @@ -961,20 +969,16 @@ int mingw_lstat(const char *file_name, struct stat *buf) filetime_to_timespec(&(fdata.ftLastWriteTime), &(buf->st_mtim)); filetime_to_timespec(&(fdata.ftCreationTime), &(buf->st_ctim)); 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: