hi,
i want to find out the name of the underlying file system from my filter driver. for example, i want to know whether the actual file system is FAT or NTFS. how do i do this ?
tia.
-gautam
Well the minifilter tells you on the instance callback. And since
mini-filters are so much easier that regular filters, one assumes you are
using a min-filter.
–
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
http://www.windrvr.com
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wrote in message news:xxxxx@ntfsd…
> hi,
>
> i want to find out the name of the underlying file system from my filter
> driver. for example, i want to know whether the actual file system is FAT
> or NTFS. how do i do this ?
>
> tia.
>
> -gautam
>
>
>
oops, i must have mentioned that my filter driver is a legacy driver.
i am not on the mini-filter band wagon yet 
In the case or a legacy filter, you’d create a
IRP_MJ_QUERY_VOLUME_INFORMATION IRP with
IrpSp->Parameters.QueryVolume.FsInformationClass set to
FILE_FS_ATTRIBUTE_INFORMATION. Much more information is available in the DDK
and WDK docs.
The information in this IRP is returned by the filesystem itself, so it can
tell you what it wants to tell you. As an aside (and a personal pet peeve of
sorts), it’s quite common for Microsoft (and other legacy filters) code to
refuse to work over your file system if it doesn’t return NTFS or FAT (with
R2 of Win2k3 server, many of the utilities [DFS-R, FSRM, etc.] don’t work
unless you’re NTFS, period). Note that the code doesn’t look at the
capabilities bits that exist in the buffer (i.e., support for alternate data
streams, etc.), just whether or not you’re named NTFS. This is a pain for
those of us who write file systems that aren’t NTFS but have most of the
same capabilities.
The mini-filter model has other mechanisms in place to tell you what the
file system is (the instance setup callback you can create in when you
register your filter.). This mechanism can’t be spoofed , which cause a
whole new set of problems for third party filesystems. To their credit, the
mini-filter folks (thanks, Neil!) are expanding the filesystems that they
recognize so this is less of an issue with Vista and Longhorn than in the
past (the callback used to return FLT_FSTYPE_UNKNOWN for any but a very
limited set of filesystems). Many (most) of the Microsoft mini-filters still
refuse to load over anything but a filesystem that returns FLT_FSTYPE_NTFS,
though.
…dave
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@gmail.com
Sent: Wednesday, September 06, 2006 11:35 AM
To: Windows File Systems Devs Interest List
Subject: RE:[ntfsd] name of lower file system
oops, i must have mentioned that my filter driver is a legacy driver.
i am not on the mini-filter band wagon yet
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@exmsft.com To unsubscribe
send a blank email to xxxxx@lists.osr.com
thanks dave,
it seems that everyone is now using minifilter to write there filter drivers. however, the service pack requrement for mini-filters is the only reason that has stopped me from going the mini-filter way.
after all, who likes to bang head for simple things like getting file names, or using dirty hacks to prevent re-entrancy.
i wish minifilter library were a separate add-on/ redistributable for os like windows 2000 …separate from the service packs.
Yes, it is available as a redistributable (actually, a hotfix).
See “A hotfix is available to add the new Filter Manager feature to
computers that are running Windows 2000 Service Pack 4”.
http://support.microsoft.com/default.aspx?scid=kb;en-us;905590&sd=rss&spid=3
071
Ken
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@gmail.com
Sent: Thursday, September 07, 2006 2:54 PM
To: Windows File Systems Devs Interest List
Subject: RE:[ntfsd] name of lower file system
thanks dave,
it seems that everyone is now using minifilter to write there filter
drivers. however, the service pack requrement for mini-filters is the only
reason that has stopped me from going the mini-filter way.
after all, who likes to bang head for simple things like getting file names,
or using dirty hacks to prevent re-entrancy.
i wish minifilter library were a separate add-on/ redistributable for os
like windows 2000 …separate from the service packs.
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@comcast.net
To unsubscribe send a blank email to xxxxx@lists.osr.com
Send the IRP_MJ_QUERY_VOLUME_INFORMATION down.
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
----- Original Message -----
From:
To: “Windows File Systems Devs Interest List”
Sent: Wednesday, September 06, 2006 10:25 PM
Subject: [ntfsd] name of lower file system
> hi,
>
> i want to find out the name of the underlying file system from my filter
driver. for example, i want to know whether the actual file system is FAT or
NTFS. how do i do this ?
>
> tia.
>
> -gautam
>
>
>
> —
> Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com