Hi,
we are developing a file system filter driver for NTFS 5 being part of an
HFS solution. File stubs are detected in IRP_MJ_CREATE, actual restore is
done in IRP_MJ_READ/_WRITE. If we open a stub’s properties menu using MS
Explorer, XP version, stubs are restored - meaning that file content data
has been accessed.
What exactly does MS Explorer try to read, e.g. extended NTFS attributes in
XP/W2003? Is there any way for a file system filter driver to distinguish
these calls from ‘normal’ IRP_MJ_READ/_WRITE?
If you set FILE_ATTRIBUTE_OFFLINE on the file when you make the file a
stub, explorer and most if not all shell extensions, don’t read from the
file anymore, but just access the attributes/properties. Also you get
the additional benefit that timeouts over SMB network accesses are
increased for such files from the default 30secs to default of 5
minutes+.
Ravi
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of sdo
Sent: Wednesday, December 08, 2004 10:25 AM
To: Windows File Systems Devs Interest List
Subject: [ntfsd] Hfs filter driver
Hi,
we are developing a file system filter driver for NTFS 5 being part of
an HFS solution. File stubs are detected in IRP_MJ_CREATE, actual
restore is done in IRP_MJ_READ/_WRITE. If we open a stub’s properties
menu using MS Explorer, XP version, stubs are restored - meaning that
file content data has been accessed.
What exactly does MS Explorer try to read, e.g. extended NTFS attributes
in XP/W2003? Is there any way for a file system filter driver to
distinguish these calls from ‘normal’ IRP_MJ_READ/_WRITE?
Hi Ravi,
thank you for your answer. Stub files have already set the offline bit, to
be
a bit more precise: Stubs are sparse files with some reparse data attached.
A stub’s file attributes are identical with the original file’s attributes
with offline
(and sparse) bits added.
When properties of stub files are accessed with W2000 Exploror, everything
works as expected, i.e. no IRP_MJ_READ/_WRITE is seen by the filter driver -
but using XP and W2003 Explorer triggers file restoration.
We have the vague idea that newer Explorer versions try to read additional
file description attributes, e.g. information used in the property’s
‘Summary’
tabpage (Title, Subject, Author,…).
Has anybody heard about such a XP and W2003 Explorer behaviour, or are
there other hints regarding this problem?
Thanks for helping, sdo
“Ravisankar Pudipeddi” wrote in message news:xxxxx@ntfsd… If you set FILE_ATTRIBUTE_OFFLINE on the file when you make the file a stub, explorer and most if not all shell extensions, don’t read from the file anymore, but just access the attributes/properties. Also you get the additional benefit that timeouts over SMB network accesses are increased for such files from the default 30secs to default of 5 minutes+.
Ravi
-----Original Message----- From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of sdo Sent: Wednesday, December 08, 2004 10:25 AM To: Windows File Systems Devs Interest List Subject: [ntfsd] Hfs filter driver
Hi, we are developing a file system filter driver for NTFS 5 being part of an HFS solution. File stubs are detected in IRP_MJ_CREATE, actual restore is done in IRP_MJ_READ/_WRITE. If we open a stub’s properties menu using MS Explorer, XP version, stubs are restored - meaning that file content data has been accessed. What exactly does MS Explorer try to read, e.g. extended NTFS attributes in XP/W2003? Is there any way for a file system filter driver to distinguish these calls from ‘normal’ IRP_MJ_READ/_WRITE?