This is the mail archive of the cygwin mailing list for the Cygwin project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: BUG: Bad call to GetFileSze in ext2fsprogs lib/ext2fs/getsize.c

On Tue, Sep 14, 2004 at 10:32:47AM -0700, Earl Chew wrote:
>Earl Chew wrote:
>>The call to GetFileSize() doesn't match the Microsoft documentation,
>>and invariably mis-sizes the disk image as zero.
>A couple of comments regarding your recent changes:
>a. GetFileSize() returns the bits 32-63 of the file size in
>   the 2nd parameter. I think code like this is more better:
>	DWORD high_filesize;
>	filesize = GetFileSize(dev, &high_filesize);
>	if (filesize != INVALID_FILE_SIZE || GetLastError() != NO_ERROR)
>		*retblocks (((unsigned long long) high_filesize << 32)
>                            + filesize) / blocksize;
>b. Use of CreateFile() causes problems because win32 doesn't know
>   about the cygwin mount points. Code like this is more flexible:
>	fd = open(file, O_RDONLY | O_BINARY);
>	if (fd == -1)
>	    return EBADF;
>	dev = (HANDLE) get_osfhandle(fd);
>	...
>	close(fd);
>c. Similarly, code in unix_io.c needs to force binary mode to
>   avoid getting incorrect results when cygwin decides the image
>   is text!
>	open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY;
>	#ifdef O_BINARY
>	open_flags |= O_BINARY;
>	#endif

Let me again point out that a cygwin program shouldn't be doing *ANY OF

It shouldn't be calling GetFileSize and it shouldn't be calling


Unsubscribe info:
Problem reports:

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]