On Wednesday, April 23 2014, "Corinna Vinschen" wrote to "cygwin at cygwin.com"
saying:
> Rather than calling GetFileInformationByHandle, try this
>
> #include <winternl.h>
>
> [...]
>
> NTSTATUS status;
> IO_STATUS_BLOCK io;
> FILE_NETWORK_OPEN_INFORMATION fnoi;
>
> status = NtQueryInformationFile (file, &io, &fnoi, sizeof fnoi,
> FileNetworkOpenInformation);
> if (!NT_SUCCESS (status))
> {
> fprintf (stderr, "NtQueryInformationFile: 0x%08x\n", status);
> [...]
> }
> printf("%s: NtQueryInformationFile: nFileSize=%" PRIu64 "\n",
> argv[i], fnoi.EndOfFile.QuadPart);
>
> Maybe that's really the problem. If so, either the EndOfFile info
> is wrong, or (more likely) the call to NtQueryInformationFile returns
> with a non-0 status code, which would be interesting to know. It's
> probably not STATUS_INVALID_PARAMETER, otherwise you probably wouldn't
> have seen a problem at all.
>
> Replacing the above call with
>
> FILE_STANDARD_INFORMATION fsi;
> status = NtQueryInformationFile (file, &io, &fsi, sizeof fsi,
> FileStandardInformation);
> [...]
> printf("%s: NtQueryInformationFile: nFileSize=%" PRIu64 "\n",
> argv[i], fsi.EndOfFile.QuadPart);
>
> should then give the correct result.
Okay, looks like FileNetworkOpenInformation is succeeding, but returning a
bad EndOfFile value.
$ ./win32-size-test 'z:\foo'
z:\foo: NtQueryInformationFile(FileNetworkOpenInformation): EndOfFile=0
z:\foo: NtQueryInformationFile(FileStandardInformation): EndOfFile=12
$ gdb --quiet --args ./win32-size-test.exe 'z:\foo'
Reading symbols from /cygdrive/z/Emacs-Modtime/win32-size-test.exe...done.
(gdb) break 82
Breakpoint 1 at 0x100401400: file win32-size-test.c, line 82.
(gdb) run
Starting program: /cygdrive/z/Emacs-Modtime/win32-size-test.exe z:\\foo
[New Thread 10540.0x48dc]
[New Thread 10540.0x39d4]
z:\\foo: NtQueryInformationFile(FileNetworkOpenInformation): EndOfFile=0
z:\\foo: NtQueryInformationFile(FileStandardInformation): EndOfFile=12
Breakpoint 1, main (argc=2, argv=0x22aaf0) at win32-size-test.c:82
82 if (!CloseHandle(file)) {
(gdb) p fnoi
$1 = {CreationTime = {{LowPart = 1493948928, HighPart = 30367507}, u = {
LowPart = 1493948928, HighPart = 30367507},
QuadPart = 130427450920000000}, LastAccessTime = {{LowPart = 1493948928,
HighPart = 30367507}, u = {LowPart = 1493948928, HighPart = 30367507},
QuadPart = 130427450920000000}, LastWriteTime = {{LowPart = 1493948928,
HighPart = 30367507}, u = {LowPart = 1493948928, HighPart = 30367507},
QuadPart = 130427450920000000}, ChangeTime = {{LowPart = 1493948928,
HighPart = 30367507}, u = {LowPart = 1493948928, HighPart = 30367507},
QuadPart = 130427450920000000}, AllocationSize = {{LowPart = 12,
HighPart = 0}, u = {LowPart = 12, HighPart = 0}, QuadPart = 12},
EndOfFile = {{LowPart = 0, HighPart = 0}, u = {LowPart = 0, HighPart = 0},
QuadPart = 0}, FileAttributes = 128}
(gdb) p fsi
$2 = {AllocationSize = {{LowPart = 12, HighPart = 0}, u = {LowPart = 12,
HighPart = 0}, QuadPart = 12}, EndOfFile = {{LowPart = 12,
HighPart = 0}, u = {LowPart = 12, HighPart = 0}, QuadPart = 12},
NumberOfLinks = 1, DeletePending = 0 '\000', Directory = 0 '\000'}
At this point this is looking pretty clearly like a Parallels Tools bug.
I'll report it to them.
> Also, to add handling for the Parallels filesystem to Cygwin, I'd
> need the info printed by the getVolInfo tool from the csih package:
>
> $ /usr/lib/csih/getVolInfo /cygdrive/z
$ /usr/lib/csih/getVolInfo.exe /cygdrive/z/
Device Type : 7
Characteristics : 10
Volume Name : <Shared Folders>
Serial Number : 0
Max Filenamelength : 255
Filesystemname : <PrlSF>
Flags : 3
FILE_CASE_SENSITIVE_SEARCH : TRUE
FILE_CASE_PRESERVED_NAMES : TRUE
FILE_UNICODE_ON_DISK : FALSE
FILE_PERSISTENT_ACLS : FALSE
FILE_FILE_COMPRESSION : FALSE
FILE_VOLUME_QUOTAS : FALSE
FILE_SUPPORTS_SPARSE_FILES : FALSE
FILE_SUPPORTS_REPARSE_POINTS: FALSE
FILE_SUPPORTS_REMOTE_STORAGE: FALSE
FILE_VOLUME_IS_COMPRESSED : FALSE
FILE_SUPPORTS_OBJECT_IDS : FALSE
FILE_SUPPORTS_ENCRYPTION : FALSE
FILE_NAMED_STREAMS : FALSE
FILE_READ_ONLY_VOLUME : FALSE
FILE_SEQUENTIAL_WRITE_ONCE : FALSE
FILE_SUPPORTS_TRANSACTIONS : FALSE
Here's my test code. Compiles with either Cygwin or mingw64 GCC, but not
classic mingw or Visual Studio due to missing headers/declarations. Link
with -lntdll.
#include <windows.h>
#include <stdio.h>
#include <inttypes.h>
#include <winternl.h>
#if __LP64__
#define PRIuDWORD "u"
#define PRIxDWORD "x"
#else
#define PRIuDWORD "lu"
#define PRIxDWORD "lx"
#endif
static const char* geterr(DWORD err)
{
static char msg[1024];
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS |
FORMAT_MESSAGE_MAX_WIDTH_MASK, NULL, err,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPSTR)msg, sizeof(msg), NULL);
return msg;
}
int main(int argc, char* argv[])
{
int i;
int exitstatus = 0;
for (i = 1; i < argc; i++) {
HANDLE file;
DWORD err, bytesWritten;
NTSTATUS ntstatus;
IO_STATUS_BLOCK io;
FILE_NETWORK_OPEN_INFORMATION fnoi;
FILE_STANDARD_INFORMATION fsi;
file = CreateFileA(argv[i], GENERIC_WRITE, FILE_SHARE_WRITE,
NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
if (file == INVALID_HANDLE_VALUE) {
err = GetLastError();
fprintf(stderr, "%s: CreateFile: %s (err 0x%08"
PRIxDWORD")\n", argv[i],
geterr(err), err);
exitstatus++;
continue;
}
if (!WriteFile(file, "Hello world!\n", 12, &bytesWritten, NULL)
||
bytesWritten != 12) {
err = GetLastError();
fprintf(stderr, "%s: WriteFile: %s (err 0x%08"
PRIxDWORD ")\n", argv[i],
geterr(err), err);
CloseHandle(file);
exitstatus++;
continue;
}
ntstatus = NtQueryInformationFile (file, &io, &fnoi, sizeof
fnoi,
FileNetworkOpenInformation);
if (!NT_SUCCESS (ntstatus)) {
fprintf (stderr, "%s:
NtQueryInformationFile(FileNetworkOpenInformation): %s (err 0x%08" PRIxDWORD
")\n",
argv[i], geterr(ntstatus), ntstatus);
}
else {
printf("%s:
NtQueryInformationFile(FileNetworkOpenInformation): EndOfFile=%" PRIu64 "\n",
argv[i], (uint64_t)fnoi.EndOfFile.QuadPart);
}
ntstatus = NtQueryInformationFile (file, &io, &fsi, sizeof fsi,
FileStandardInformation);
if (!NT_SUCCESS (ntstatus)) {
fprintf (stderr, "%s:
NtQueryInformationFile(FileStandardInformation): %s (err 0x%08" PRIxDWORD ")\n",
argv[i], geterr(ntstatus), ntstatus);
}
else {
printf("%s:
NtQueryInformationFile(FileStandardInformation): EndOfFile=%" PRIu64 "\n",
argv[i], (uint64_t)fsi.EndOfFile.QuadPart);
}
if (!CloseHandle(file)) {
err = GetLastError();
fprintf(stderr, "%s: CloseHandle: %s (err %" PRIxDWORD
")\n", argv[i],
geterr(err), err);
exitstatus++;
continue;
}
}
return exitstatus;
}
--
Jonathan Lennox
lennox at cs.columbia.edu
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