flushing of cache when doing nocache read

NTFSD
1

hi,

i read from the OSR doc in the wxp ifs kit that for nocache read, the cache
will be ignored. but when i do a nocache read from my fsfd, the ntfs fsd
will do a ccflushcache… is this expected?

thanks!

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

2

Look at the fastfat source for an explanation. Here is the comment:

//
// If this is a noncached transfer and is not a paging I/O,
and
// the file has a data section, then we will do a flush
here
// to avoid stale data problems. Note that we must flush
before
// acquiring the Fcb shared since the write may try to
acquire
// it exclusive.
//

  • Nicholas Ryan

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Ho Mun Chuen
Sent: Wednesday, October 09, 2002 8:48 PM
To: File Systems Developers
Subject: [ntfsd] flushing of cache when doing nocache read

hi,

i read from the OSR doc in the wxp ifs kit that for nocache
read, the cache will be ignored. but when i do a nocache read
from my fsfd, the ntfs fsd will do a ccflushcache… is this expected?

thanks!

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!

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: Thursday, October 10, 2002 11:59 AM
Subject: [ntfsd] RE: flushing of cache when doing nocache read

Look at the fastfat source for an explanation. Here is the comment:

//
// If this is a noncached transfer and is not a paging I/O,
and
// the file has a data section, then we will do a flush
here
// to avoid stale data problems. Note that we must flush
before
// acquiring the Fcb shared since the write may try to
acquire
// it exclusive.
//

- Nicholas Ryan

> -----Original Message-----
> From: xxxxx@lists.osr.com
> [mailto:xxxxx@lists.osr.com] On Behalf Of Ho Mun Chuen
> Sent: Wednesday, October 09, 2002 8:48 PM
> To: File Systems Developers
> Subject: [ntfsd] flushing of cache when doing nocache read
>
>
> hi,
>
> i read from the OSR doc in the wxp ifs kit that for nocache
> read, the cache will be ignored. but when i do a nocache read
> from my fsfd, the ntfs fsd will do a ccflushcache… is this expected?
>
> thanks!
>
> 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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