diff options
Diffstat (limited to 'compat/mingw.c')
| -rw-r--r-- | compat/mingw.c | 157 |
1 files changed, 151 insertions, 6 deletions
diff --git a/compat/mingw.c b/compat/mingw.c index 0ff550cef3..63f36c893b 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -502,7 +502,7 @@ static int mingw_open_append(wchar_t const *wfilename, int oflags, ...) * to append to the file. */ handle = CreateFileW(wfilename, FILE_APPEND_DATA, - FILE_SHARE_WRITE | FILE_SHARE_READ, + FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE, NULL, create, FILE_ATTRIBUTE_NORMAL, NULL); if (handle == INVALID_HANDLE_VALUE) { DWORD err = GetLastError(); @@ -533,6 +533,70 @@ static int mingw_open_append(wchar_t const *wfilename, int oflags, ...) } /* + * Ideally, we'd use `_wopen()` to implement this functionality so that we + * don't have to reimplement it, but unfortunately we do not have tight control + * over the share mode there. And while `_wsopen()` and friends exist that give + * us _some_ control over the share mode, this family of functions doesn't give + * us the ability to enable FILE_SHARE_DELETE, either. But this is a strict + * requirement for us though so that we can unlink or rename over files that + * are held open by another process. + * + * We are thus forced to implement our own emulation of `open()`. To make our + * life simpler we only implement basic support for this, namely opening + * existing files for reading and/or writing. This means that newly created + * files won't have their sharing mode set up correctly, but for now I couldn't + * find any case where this matters. We may have to revisit that in the future + * though based on our needs. + */ +static int mingw_open_existing(const wchar_t *filename, int oflags, ...) +{ + SECURITY_ATTRIBUTES security_attributes = { + .nLength = sizeof(security_attributes), + .bInheritHandle = !(oflags & O_NOINHERIT), + }; + HANDLE handle; + DWORD access; + int fd; + + /* We only support basic flags. */ + if (oflags & ~(O_ACCMODE | O_NOINHERIT)) { + errno = ENOSYS; + return -1; + } + + switch (oflags & O_ACCMODE) { + case O_RDWR: + access = GENERIC_READ | GENERIC_WRITE; + break; + case O_WRONLY: + access = GENERIC_WRITE; + break; + default: + access = GENERIC_READ; + break; + } + + handle = CreateFileW(filename, access, + FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE, + &security_attributes, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); + if (handle == INVALID_HANDLE_VALUE) { + DWORD err = GetLastError(); + + /* See `mingw_open_append()` for why we have this conversion. */ + if (err == ERROR_INVALID_PARAMETER) + err = ERROR_PATH_NOT_FOUND; + + errno = err_win_to_posix(err); + return -1; + } + + fd = _open_osfhandle((intptr_t)handle, oflags | O_BINARY); + if (fd < 0) + CloseHandle(handle); + return fd; +} + +/* * Does the pathname map to the local named pipe filesystem? * That is, does it have a "//./pipe/" prefix? */ @@ -567,6 +631,8 @@ int mingw_open (const char *filename, int oflags, ...) if ((oflags & O_APPEND) && !is_local_named_pipe_path(filename)) open_fn = mingw_open_append; + else if (!(oflags & ~(O_ACCMODE | O_NOINHERIT))) + open_fn = mingw_open_existing; else open_fn = _wopen; @@ -1006,7 +1072,7 @@ int mingw_utime (const char *file_name, const struct utimbuf *times) osfilehandle = CreateFileW(wfilename, FILE_WRITE_ATTRIBUTES, - 0 /*FileShare.None*/, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, OPEN_EXISTING, (attrs != INVALID_FILE_ATTRIBUTES && @@ -2155,10 +2221,16 @@ int mingw_accept(int sockfd1, struct sockaddr *sa, socklen_t *sz) #undef rename int mingw_rename(const char *pold, const char *pnew) { + static int supports_file_rename_info_ex = 1; DWORD attrs, gle; int tries = 0; wchar_t wpold[MAX_PATH], wpnew[MAX_PATH]; - if (xutftowcs_path(wpold, pold) < 0 || xutftowcs_path(wpnew, pnew) < 0) + int wpnew_len; + + if (xutftowcs_path(wpold, pold) < 0) + return -1; + wpnew_len = xutftowcs_path(wpnew, pnew); + if (wpnew_len < 0) return -1; /* @@ -2169,11 +2241,84 @@ int mingw_rename(const char *pold, const char *pnew) return 0; if (errno != EEXIST) return -1; + repeat: - if (MoveFileExW(wpold, wpnew, MOVEFILE_REPLACE_EXISTING)) - return 0; + if (supports_file_rename_info_ex) { + /* + * Our minimum required Windows version is still set to Windows + * Vista. We thus have to declare required infrastructure for + * FileRenameInfoEx ourselves until we bump _WIN32_WINNT to + * 0x0A00. Furthermore, we have to handle cases where the + * FileRenameInfoEx call isn't supported yet. + */ +#define FILE_RENAME_FLAG_REPLACE_IF_EXISTS 0x00000001 +#define FILE_RENAME_FLAG_POSIX_SEMANTICS 0x00000002 + FILE_INFO_BY_HANDLE_CLASS FileRenameInfoEx = 22; + struct { + /* + * This is usually an unnamed union, but that is not + * part of ISO C99. We thus inline the field, as we + * really only care for the Flags field anyway. + */ + DWORD Flags; + HANDLE RootDirectory; + DWORD FileNameLength; + /* + * The actual structure is defined with a single-character + * flex array so that the structure has to be allocated on + * the heap. As we declare this structure ourselves though + * we can avoid the allocation and define FileName to have + * MAX_PATH bytes. + */ + WCHAR FileName[MAX_PATH]; + } rename_info = { 0 }; + HANDLE old_handle = INVALID_HANDLE_VALUE; + BOOL success; + + old_handle = CreateFileW(wpold, DELETE, + FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE, + NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); + if (old_handle == INVALID_HANDLE_VALUE) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + + rename_info.Flags = FILE_RENAME_FLAG_REPLACE_IF_EXISTS | + FILE_RENAME_FLAG_POSIX_SEMANTICS; + rename_info.FileNameLength = wpnew_len * sizeof(WCHAR); + memcpy(rename_info.FileName, wpnew, wpnew_len * sizeof(WCHAR)); + + success = SetFileInformationByHandle(old_handle, FileRenameInfoEx, + &rename_info, sizeof(rename_info)); + gle = GetLastError(); + CloseHandle(old_handle); + if (success) + return 0; + + /* + * When we see ERROR_INVALID_PARAMETER we can assume that the + * current system doesn't support FileRenameInfoEx. Keep us + * from using it in future calls and retry. + */ + if (gle == ERROR_INVALID_PARAMETER) { + supports_file_rename_info_ex = 0; + goto repeat; + } + + /* + * In theory, we shouldn't get ERROR_ACCESS_DENIED because we + * always open files with FILE_SHARE_DELETE But in practice we + * cannot assume that Git is the only one accessing files, and + * other applications may not set FILE_SHARE_DELETE. So we have + * to retry. + */ + } else { + if (MoveFileExW(wpold, wpnew, MOVEFILE_REPLACE_EXISTING)) + return 0; + gle = GetLastError(); + } + /* TODO: translate more errors */ - gle = GetLastError(); if (gle == ERROR_ACCESS_DENIED && (attrs = GetFileAttributesW(wpnew)) != INVALID_FILE_ATTRIBUTES) { if (attrs & FILE_ATTRIBUTE_DIRECTORY) { |