On Apr 9 22:30, Brian Inglis via Cygwin wrote: > On 2024-04-09 15:14, Corinna Vinschen via Cygwin wrote: > > On Apr 5 04:26, Martin Wege via Cygwin wrote: > > > On Fri, Apr 5, 2024 at 2:05 AM Martin Wege <martin.l.w...@gmail.com> > > > wrote: > > > > I have problems with debugging, so a quick help would be appreciated, > > > > as I cannot figure this out after several hours of digging. > > > > > > > > Cygwin /usr/bin/stat returns "Birth: -" for some files. Which value > > > > must the CreationTime member of FILE_BASIC_INFORMATION have to cause > > > > /usr/bin/stat ti return "-"? 0, -1, or something else? > > > > > > In a related matter: > > > The Win32 FILE_BASIC_INFORMATION structure defines four time values: > > > > > > LARGE_INTEGER CreationTime; > > > LARGE_INTEGER LastAccessTime; > > > LARGE_INTEGER LastWriteTime; > > > LARGE_INTEGER ChangeTime; > > > > > > How can a filesystem indicate if it does not support a particular > > > timestamp, such as ChangeTime? Should ChangeTime.QuadPart then be -1, > > > -2 or 0, or another value? > > > > I'm not aware of a filesystem not supporting ChangeTime, that is, > > st_ctime. Usually only CreationTime (st_birthtime) is missing. > > R/O media like CD/DVD-R or FS w/o write support?
Oh yes, that makes sense, CDFS and the likes of them. > > I think setting the timestamp to 0 works for indicating that this kind > > of timestamp is not supported. Cygwin is handling Windows timestamps > > this way, but I can't find this in documentation ATM. > > See upthread?: > > Caller or application can set 0 to mean keep/return current value, caller or > driver can set -1 to mean don't update/return current value: > > https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/wdm/ns-wdm-_file_basic_information#remarks I'm aware of that. This remarks session is copy/pasted in other MSFT articles, too. But it doesn't really answer Martin's question. It describes what a consumer (application or driver) is supposed to set the timestamps to when passing timestamps to a filesystem driver via ZwSetInformationFile (or its friends on the lower OS levels). It does *not* describe the other direction of the call stack, i. e., what a filesystem driver is supposed to set a timestamp to, if its underlying filesystem doesn't support this kind of timestamp. And that's the direction Martin is asking about. Corinna -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
