FSCTL_GET_RETRIEVAL_POINTERS on Non NTFS volumes

Hi,

Does FSCTL_GET_RETRIEVAL_POINTERS FSCT work for non NTFS
volumes? I have been trying to get the LCN’s for a file on FAT 32 volumes,
the fsctl succeeds, but when I ReadFile() from the LCN (offset =
LCN*sectors/cluster*bytes/sector)
the data is not of the actual file. The same thing works well on NTFS
volume. Am I missing
something?

TIA,

-Farooque Khan
http://farooque.150m.com

Hey,
In fat all LCN counting starts from Starting data area i.e. after FAT.your
formula for fat should be
StartingDataSector *bytes/sector+LCN*sectors/cluster*bytes/sector.
regards,
Johri.


“Farooque Khan” wrote in message
news:xxxxx@ntfsd…
> Hi,
>
> Does FSCTL_GET_RETRIEVAL_POINTERS FSCT work for non NTFS
> volumes? I have been trying to get the LCN’s for a file on FAT 32
volumes,
> the fsctl succeeds, but when I ReadFile() from the LCN (offset =
> LCNsectors/clusterbytes/sector)
> the data is not of the actual file. The same thing works well on NTFS
> volume. Am I missing
> something?
>
> TIA,
>
>
> –
>
> -Farooque Khan
> http://farooque.150m.com
>
>
>
>
>
>

thanks,

-Farooque Khan
http://farooque.150m.com

“Amritanshu” wrote in message
news:xxxxx@ntfsd…
> Hey,
> In fat all LCN counting starts from Starting data area i.e. after FAT.your
> formula for fat should be
> StartingDataSector bytes/sector+LCNsectors/clusterbytes/sector.
> regards,
> Johri.
>
> ______________
> “Farooque Khan” wrote in message
> news:xxxxx@ntfsd…
> > Hi,
> >
> > Does FSCTL_GET_RETRIEVAL_POINTERS FSCT work for non NTFS
> > volumes? I have been trying to get the LCN’s for a file on FAT 32
> volumes,
> > the fsctl succeeds, but when I ReadFile() from the LCN (offset =
> > LCN
sectors/cluster*bytes/sector)
> > the data is not of the actual file. The same thing works well on NTFS
> > volume. Am I missing
> > something?
> >
> > TIA,
> >
> >
> > –
> >
> > -Farooque Khan
> > http://farooque.150m.com
> >
> >
> >
> >
> >
> >
>
>
>

Hi, how can I find out the StartingDataSector, is it just
the size of FAT table?

Thanks again,

-Farooque Khan
http://farooque.150m.com

“Amritanshu” wrote in message
news:xxxxx@ntfsd…
> Hey,
> In fat all LCN counting starts from Starting data area i.e. after FAT.your
> formula for fat should be
> StartingDataSector bytes/sector+LCNsectors/clusterbytes/sector.
> regards,
> Johri.
>
> ______________
> “Farooque Khan” wrote in message
> news:xxxxx@ntfsd…
> > Hi,
> >
> > Does FSCTL_GET_RETRIEVAL_POINTERS FSCT work for non NTFS
> > volumes? I have been trying to get the LCN’s for a file on FAT 32
> volumes,
> > the fsctl succeeds, but when I ReadFile() from the LCN (offset =
> > LCN
sectors/cluster*bytes/sector)
> > the data is not of the actual file. The same thing works well on NTFS
> > volume. Am I missing
> > something?
> >
> > TIA,
> >
> >
> > –
> >
> > -Farooque Khan
> > http://farooque.150m.com
> >
> >
> >
> >
> >
> >
>
>
>

You need to calculate it based on the type of FAT(16 or 32) you get the
values from Bios Parameter Block of the volume the data structures are well
known
http://www.ntfs.com/fat-systems.htm
check the link out this might help


“Farooque Khan” wrote in message
news:xxxxx@ntfsd…
> Hi, how can I find out the StartingDataSector, is it just
> the size of FAT table?
>
> Thanks again,
>
> –
>
> -Farooque Khan
> http://farooque.150m.com
>
>
>
>
> “Amritanshu” wrote in message
> news:xxxxx@ntfsd…
> > Hey,
> > In fat all LCN counting starts from Starting data area i.e. after
FAT.your
> > formula for fat should be
> > StartingDataSector bytes/sector+LCNsectors/clusterbytes/sector.
> > regards,
> > Johri.
> >
> > ______________
> > “Farooque Khan” wrote in message
> > news:xxxxx@ntfsd…
> > > Hi,
> > >
> > > Does FSCTL_GET_RETRIEVAL_POINTERS FSCT work for non NTFS
> > > volumes? I have been trying to get the LCN’s for a file on FAT 32
> > volumes,
> > > the fsctl succeeds, but when I ReadFile() from the LCN (offset =
> > > LCN
sectors/cluster*bytes/sector)
> > > the data is not of the actual file. The same thing works well on NTFS
> > > volume. Am I missing
> > > something?
> > >
> > > TIA,
> > >
> > >
> > > –
> > >
> > > -Farooque Khan
> > > http://farooque.150m.com
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
>
>
>

thanks, it works now!

Regards,

-Farooque Khan
http://farooque.150m.com

“Amritanshu” wrote in message
news:xxxxx@ntfsd…
>
> You need to calculate it based on the type of FAT(16 or 32) you get the
> values from Bios Parameter Block of the volume the data structures are
well
> known
> http://www.ntfs.com/fat-systems.htm
> check the link out this might help
> _________________
> “Farooque Khan” wrote in message
> news:xxxxx@ntfsd…
> > Hi, how can I find out the StartingDataSector, is it just
> > the size of FAT table?
> >
> > Thanks again,
> >
> > –
> >
> > -Farooque Khan
> > http://farooque.150m.com
> >
> >
> >
> >
> > “Amritanshu” wrote in message
> > news:xxxxx@ntfsd…
> > > Hey,
> > > In fat all LCN counting starts from Starting data area i.e. after
> FAT.your
> > > formula for fat should be
> > > StartingDataSector bytes/sector+LCNsectors/cluster*bytes/sector.
> > > regards,
> > > Johri.
> > >
> > >

> > > “Farooque Khan” wrote in message
> > > news:xxxxx@ntfsd…
> > > > Hi,
> > > >
> > > > Does FSCTL_GET_RETRIEVAL_POINTERS FSCT work for non NTFS
> > > > volumes? I have been trying to get the LCN’s for a file on FAT 32
> > > volumes,
> > > > the fsctl succeeds, but when I ReadFile() from the LCN (offset =
> > > > LCNsectors/clusterbytes/sector)
> > > > the data is not of the actual file. The same thing works well on
NTFS
> > > > volume. Am I missing
> > > > something?
> > > >
> > > > TIA,
> > > >
> > > >
> > > > –
> > > >
> > > > -Farooque Khan
> > > > http://farooque.150m.com
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> >
> >
> >
>
>
>