* Cygwin /usr/bin/stat returns "Birth: -", which value in FILE_BASIC_INFORMATION.CreationTime causes that?
@ 2024-04-05 0:05 Martin Wege
2024-04-05 0:54 ` Brian Inglis
2024-04-05 2:26 ` Win32 FILE_BASIC_INFORMATION.*Time.QuadPart - which value should be used if filesystem does not support it, so Cygwin /usr/bin/stat lists the value as '-'? Martin Wege
0 siblings, 2 replies; 8+ messages in thread
From: Martin Wege @ 2024-04-05 0:05 UTC (permalink / raw)
To: cygwin
Hello,
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?
Thanks,
Martin
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Cygwin /usr/bin/stat returns "Birth: -", which value in FILE_BASIC_INFORMATION.CreationTime causes that?
2024-04-05 0:05 Cygwin /usr/bin/stat returns "Birth: -", which value in FILE_BASIC_INFORMATION.CreationTime causes that? Martin Wege
@ 2024-04-05 0:54 ` Brian Inglis
2024-04-05 1:08 ` Martin Wege
2024-04-05 2:26 ` Win32 FILE_BASIC_INFORMATION.*Time.QuadPart - which value should be used if filesystem does not support it, so Cygwin /usr/bin/stat lists the value as '-'? Martin Wege
1 sibling, 1 reply; 8+ messages in thread
From: Brian Inglis @ 2024-04-05 0:54 UTC (permalink / raw)
To: cygwin
On 2024-04-04 18:05, Martin Wege via Cygwin 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?
https://git.savannah.gnu.org/cgit/coreutils.git/tree/src/stat.c#n1618
=> tv_nsec < 0
https://cygwin.com/git?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/fhandler/disk_file.cc#l414
https://cygwin.com/git/?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/times.cc#l283
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Cygwin /usr/bin/stat returns "Birth: -", which value in FILE_BASIC_INFORMATION.CreationTime causes that?
2024-04-05 0:54 ` Brian Inglis
@ 2024-04-05 1:08 ` Martin Wege
2024-04-05 15:51 ` Brian Inglis
0 siblings, 1 reply; 8+ messages in thread
From: Martin Wege @ 2024-04-05 1:08 UTC (permalink / raw)
To: cygwin
On Fri, Apr 5, 2024 at 2:55 AM Brian Inglis via Cygwin
<cygwin@cygwin.com> wrote:
>
> On 2024-04-04 18:05, Martin Wege via Cygwin 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?
>
> https://git.savannah.gnu.org/cgit/coreutils.git/tree/src/stat.c#n1618
>
> => tv_nsec < 0
>
> https://cygwin.com/git?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/fhandler/disk_file.cc#l414
>
> https://cygwin.com/git/?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/times.cc#l283
Thank you
But how can tv_nsec become negative (tv_nsec < 0)? That can only
happen if BasicInformation.CreationTime.QuadPart is negative, right?
Thanks,
Martin
^ permalink raw reply [flat|nested] 8+ messages in thread
* Win32 FILE_BASIC_INFORMATION.*Time.QuadPart - which value should be used if filesystem does not support it, so Cygwin /usr/bin/stat lists the value as '-'?
2024-04-05 0:05 Cygwin /usr/bin/stat returns "Birth: -", which value in FILE_BASIC_INFORMATION.CreationTime causes that? Martin Wege
2024-04-05 0:54 ` Brian Inglis
@ 2024-04-05 2:26 ` Martin Wege
2024-04-09 21:14 ` Corinna Vinschen
1 sibling, 1 reply; 8+ messages in thread
From: Martin Wege @ 2024-04-05 2:26 UTC (permalink / raw)
To: cygwin
On Fri, Apr 5, 2024 at 2:05 AM Martin Wege <martin.l.wege@gmail.com> wrote:
>
> Hello,
>
> 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?
Thanks,
Martin
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Cygwin /usr/bin/stat returns "Birth: -", which value in FILE_BASIC_INFORMATION.CreationTime causes that?
2024-04-05 1:08 ` Martin Wege
@ 2024-04-05 15:51 ` Brian Inglis
0 siblings, 0 replies; 8+ messages in thread
From: Brian Inglis @ 2024-04-05 15:51 UTC (permalink / raw)
To: cygwin
On 2024-04-04 19:08, Martin Wege via Cygwin wrote:
> On Fri, Apr 5, 2024 at 2:55 AM Brian Inglis via Cygwin
> <cygwin@cygwin.com> wrote:
>>
>> On 2024-04-04 18:05, Martin Wege via Cygwin 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?
>>
>> https://git.savannah.gnu.org/cgit/coreutils.git/tree/src/stat.c#n1618
>>
>> => tv_nsec < 0
>>
>> https://cygwin.com/git?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/fhandler/disk_file.cc#l414
>>
>> https://cygwin.com/git/?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/times.cc#l283
>
> Thank you
>
> But how can tv_nsec become negative (tv_nsec < 0)? That can only
> happen if BasicInformation.CreationTime.QuadPart is negative, right?
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
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Win32 FILE_BASIC_INFORMATION.*Time.QuadPart - which value should be used if filesystem does not support it, so Cygwin /usr/bin/stat lists the value as '-'?
2024-04-05 2:26 ` Win32 FILE_BASIC_INFORMATION.*Time.QuadPart - which value should be used if filesystem does not support it, so Cygwin /usr/bin/stat lists the value as '-'? Martin Wege
@ 2024-04-09 21:14 ` Corinna Vinschen
2024-04-10 4:30 ` Brian Inglis
0 siblings, 1 reply; 8+ messages in thread
From: Corinna Vinschen @ 2024-04-09 21:14 UTC (permalink / raw)
To: cygwin
On Apr 5 04:26, Martin Wege via Cygwin wrote:
> On Fri, Apr 5, 2024 at 2:05 AM Martin Wege <martin.l.wege@gmail.com> wrote:
> >
> > Hello,
> >
> > 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.
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.
But the FS driver can also just fill the CreationTime field with the
same value as LastWriteTime or ChangeTime. MSFT NFS does that.
Corinna
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Win32 FILE_BASIC_INFORMATION.*Time.QuadPart - which value should be used if filesystem does not support it, so Cygwin /usr/bin/stat lists the value as '-'?
2024-04-09 21:14 ` Corinna Vinschen
@ 2024-04-10 4:30 ` Brian Inglis
2024-04-10 7:59 ` Corinna Vinschen
0 siblings, 1 reply; 8+ messages in thread
From: Brian Inglis @ 2024-04-10 4:30 UTC (permalink / raw)
To: cygwin
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.wege@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?
> 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
> But the FS driver can also just fill the CreationTime field with the
> same value as LastWriteTime or ChangeTime. MSFT NFS does that.
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Win32 FILE_BASIC_INFORMATION.*Time.QuadPart - which value should be used if filesystem does not support it, so Cygwin /usr/bin/stat lists the value as '-'?
2024-04-10 4:30 ` Brian Inglis
@ 2024-04-10 7:59 ` Corinna Vinschen
0 siblings, 0 replies; 8+ messages in thread
From: Corinna Vinschen @ 2024-04-10 7:59 UTC (permalink / raw)
To: cygwin
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.wege@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
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2024-04-10 7:59 UTC | newest]
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2024-04-05 0:05 Cygwin /usr/bin/stat returns "Birth: -", which value in FILE_BASIC_INFORMATION.CreationTime causes that? Martin Wege
2024-04-05 0:54 ` Brian Inglis
2024-04-05 1:08 ` Martin Wege
2024-04-05 15:51 ` Brian Inglis
2024-04-05 2:26 ` Win32 FILE_BASIC_INFORMATION.*Time.QuadPart - which value should be used if filesystem does not support it, so Cygwin /usr/bin/stat lists the value as '-'? Martin Wege
2024-04-09 21:14 ` Corinna Vinschen
2024-04-10 4:30 ` Brian Inglis
2024-04-10 7:59 ` Corinna Vinschen
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