diff options
| -rw-r--r-- | src/port/open.c | 4 | ||||
| -rw-r--r-- | src/port/win32stat.c | 177 |
2 files changed, 49 insertions, 132 deletions
diff --git a/src/port/open.c b/src/port/open.c index 14c6debba91..4bd11ca9d90 100644 --- a/src/port/open.c +++ b/src/port/open.c @@ -157,9 +157,9 @@ pgwin32_open(const char *fileName, int fileFlags,...) { if (loops < 10) { - struct stat st; + struct microsoft_native_stat st; - if (stat(fileName, &st) != 0) + if (microsoft_native_stat(fileName, &st) != 0) { pg_usleep(100000); loops++; diff --git a/src/port/win32stat.c b/src/port/win32stat.c index 2ad8ee13595..0257956f46b 100644 --- a/src/port/win32stat.c +++ b/src/port/win32stat.c @@ -19,53 +19,6 @@ #include <windows.h> /* - * In order to support MinGW and MSVC2013 we use NtQueryInformationFile as an - * alternative for GetFileInformationByHandleEx. It is loaded from the ntdll - * library. - */ -#if _WIN32_WINNT < 0x0600 -#include <winternl.h> - -#if !defined(__MINGW32__) && !defined(__MINGW64__) -/* MinGW includes this in <winternl.h>, but it is missing in MSVC */ -typedef struct _FILE_STANDARD_INFORMATION -{ - LARGE_INTEGER AllocationSize; - LARGE_INTEGER EndOfFile; - ULONG NumberOfLinks; - BOOLEAN DeletePending; - BOOLEAN Directory; -} FILE_STANDARD_INFORMATION; -#define FileStandardInformation 5 -#endif /* !defined(__MINGW32__) && - * !defined(__MINGW64__) */ - -typedef NTSTATUS (NTAPI * PFN_NTQUERYINFORMATIONFILE) - (IN HANDLE FileHandle, - OUT PIO_STATUS_BLOCK IoStatusBlock, - OUT PVOID FileInformation, - IN ULONG Length, - IN FILE_INFORMATION_CLASS FileInformationClass); - -static PFN_NTQUERYINFORMATIONFILE _NtQueryInformationFile = NULL; - -static HMODULE ntdll = NULL; - -/* - * Load DLL file just once regardless of how many functions we load/call in it. - */ -static void -LoadNtdll(void) -{ - if (ntdll != NULL) - return; - ntdll = LoadLibraryEx("ntdll.dll", NULL, 0); -} - -#endif /* _WIN32_WINNT < 0x0600 */ - - -/* * Convert a FILETIME struct into a 64 bit time_t. */ static __time64_t @@ -163,115 +116,79 @@ _pgstat64(const char *name, struct stat *buf) { /* * We must use a handle so lstat() returns the information of the target - * file. To have a reliable test for ERROR_DELETE_PENDING, we use - * NtQueryInformationFile from Windows 2000 or - * GetFileInformationByHandleEx from Server 2008 / Vista. + * file. To have a reliable test for ERROR_DELETE_PENDING, this uses a + * method similar to open() with a loop using stat() and some waits when + * facing ERROR_ACCESS_DENIED. */ SECURITY_ATTRIBUTES sa; HANDLE hFile; int ret; -#if _WIN32_WINNT < 0x0600 - IO_STATUS_BLOCK ioStatus; - FILE_STANDARD_INFORMATION standardInfo; -#else - FILE_STANDARD_INFO standardInfo; -#endif + int loops = 0; if (name == NULL || buf == NULL) { errno = EINVAL; return -1; } - /* fast not-exists check */ if (GetFileAttributes(name) == INVALID_FILE_ATTRIBUTES) { - _dosmaperr(GetLastError()); - return -1; - } - - /* get a file handle as lightweight as we can */ - sa.nLength = sizeof(SECURITY_ATTRIBUTES); - sa.bInheritHandle = TRUE; - sa.lpSecurityDescriptor = NULL; - hFile = CreateFile(name, - GENERIC_READ, - (FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE), - &sa, - OPEN_EXISTING, - (FILE_FLAG_NO_BUFFERING | FILE_FLAG_BACKUP_SEMANTICS | - FILE_FLAG_OVERLAPPED), - NULL); - if (hFile == INVALID_HANDLE_VALUE) - { DWORD err = GetLastError(); - CloseHandle(hFile); - _dosmaperr(err); - return -1; - } - - memset(&standardInfo, 0, sizeof(standardInfo)); - -#if _WIN32_WINNT < 0x0600 - if (_NtQueryInformationFile == NULL) - { - /* First time through: load ntdll.dll and find NtQueryInformationFile */ - LoadNtdll(); - if (ntdll == NULL) - { - DWORD err = GetLastError(); - - CloseHandle(hFile); - _dosmaperr(err); - return -1; - } - - _NtQueryInformationFile = (PFN_NTQUERYINFORMATIONFILE) (pg_funcptr_t) - GetProcAddress(ntdll, "NtQueryInformationFile"); - if (_NtQueryInformationFile == NULL) + if (err != ERROR_ACCESS_DENIED) { - DWORD err = GetLastError(); - - CloseHandle(hFile); _dosmaperr(err); return -1; } } - if (!NT_SUCCESS(_NtQueryInformationFile(hFile, &ioStatus, &standardInfo, - sizeof(standardInfo), - FileStandardInformation))) - { - DWORD err = GetLastError(); - - CloseHandle(hFile); - _dosmaperr(err); - return -1; - } -#else - if (!GetFileInformationByHandleEx(hFile, FileStandardInfo, &standardInfo, - sizeof(standardInfo))) + /* get a file handle as lightweight as we can */ + sa.nLength = sizeof(SECURITY_ATTRIBUTES); + sa.bInheritHandle = TRUE; + sa.lpSecurityDescriptor = NULL; + while ((hFile = CreateFile(name, + GENERIC_READ, + (FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE), + &sa, + OPEN_EXISTING, + (FILE_FLAG_NO_BUFFERING | FILE_FLAG_BACKUP_SEMANTICS | + FILE_FLAG_OVERLAPPED), + NULL)) == INVALID_HANDLE_VALUE) { DWORD err = GetLastError(); - CloseHandle(hFile); - _dosmaperr(err); - return -1; - } -#endif /* _WIN32_WINNT < 0x0600 */ - - if (standardInfo.DeletePending) - { /* - * File has been deleted, but is not gone from the filesystem yet. - * This can happen when some process with FILE_SHARE_DELETE has it - * open, and it will be fully removed once that handle is closed. - * Meanwhile, we can't open it, so indicate that the file just doesn't - * exist. + * ERROR_ACCESS_DENIED is returned if the file is deleted but not yet + * gone (Windows NT status code is STATUS_DELETE_PENDING). In that + * case we want to wait a bit and try again, giving up after 1 second + * (since this condition should never persist very long). However, + * there are other commonly-hit cases that return ERROR_ACCESS_DENIED, + * so care is needed. In particular that happens if we try to open a + * directory, or of course if there's an actual file-permissions + * problem. To distinguish these cases, try a stat(). In the + * delete-pending case, it will either also get STATUS_DELETE_PENDING, + * or it will see the file as gone and fail with ENOENT. In other + * cases it will usually succeed. The only somewhat-likely case where + * this coding will uselessly wait is if there's a permissions problem + * with a containing directory, which we hope will never happen in any + * performance-critical code paths. */ - CloseHandle(hFile); - errno = ENOENT; + if (err == ERROR_ACCESS_DENIED) + { + if (loops < 10) + { + struct microsoft_native_stat st; + + if (microsoft_native_stat(name, &st) != 0) + { + pg_usleep(100000); + loops++; + continue; + } + } + } + + _dosmaperr(err); return -1; } |