how to use paging reads and writes

NTFSD
1

hi,

i am trying to use paging reads and writes to access a file. although i have
not encountered any error through the rdr, i have encountered the
STATUS_NOT_IMPLEMENTED error with NTFS and FAT. is there some rules to using
paging io? like offset must be in certain boundary?

Ho Mun Chuen
@@ “Not everything that counts can be counted;
<” )~ and not everything that can be counted counts"
//\ … Albert Einstein

2

At the very least paging I/O writes must begin on a sector boundary, and
must end on a sector boundary if the ending offset is less than the
current valid data length. Rule of thumb is to align your offset and
length to the sector boundary.

  • Nicholas Ryan

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Ho Mun Chuen
Sent: Wednesday, November 27, 2002 12:05 AM
To: File Systems Developers
Subject: [ntfsd] how to use paging reads and writes

hi,

i am trying to use paging reads and writes to access a file.
although i have not encountered any error through the rdr, i
have encountered the STATUS_NOT_IMPLEMENTED error with NTFS
and FAT. is there some rules to using paging io? like offset
must be in certain boundary?

Ho Mun Chuen
@@ “Not everything that counts can be counted;
<” )~ and not everything that can be counted counts"
//\ … Albert Einstein

You are currently subscribed to ntfsd as: xxxxx@nryan.com
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3

thanks, i suspected so. i had no problem initially with paging io of 512
bytes.

Ho Mun Chuen
@@ “Not everything that counts can be counted;
<” )~ and not everything that can be counted counts"
//\ … Albert Einstein
----- Original Message -----
From: “Nicholas Ryan”
To: “File Systems Developers”
Sent: Wednesday, November 27, 2002 4:59 PM
Subject: [ntfsd] RE: how to use paging reads and writes

At the very least paging I/O writes must begin on a sector boundary, and
must end on a sector boundary if the ending offset is less than the
current valid data length. Rule of thumb is to align your offset and
length to the sector boundary.

- Nicholas Ryan

> -----Original Message-----
> From: xxxxx@lists.osr.com
> [mailto:xxxxx@lists.osr.com] On Behalf Of Ho Mun Chuen
> Sent: Wednesday, November 27, 2002 12:05 AM
> To: File Systems Developers
> Subject: [ntfsd] how to use paging reads and writes
>
>
> hi,
>
> i am trying to use paging reads and writes to access a file.
> although i have not encountered any error through the rdr, i
> have encountered the STATUS_NOT_IMPLEMENTED error with NTFS
> and FAT. is there some rules to using paging io? like offset
> must be in certain boundary?
>
> Ho Mun Chuen
> @@ “Not everything that counts can be counted;
> <” )~ and not everything that can be counted counts"
> //\ … Albert Einstein
>
>
>
>
> —
> You are currently subscribed to ntfsd as: xxxxx@nryan.com
> To unsubscribe send a blank email to %%email.unsub%%
>

—
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