Text 2585, 60 rader
Skriven 2011-04-02 18:59:49 av Jonathan de Boyne Pollard
Ärende: Re: formatting to FAT32
===============================
Gecko/20110303 Thunderbird/3.1.9
comp.os.os2.misc,comp.os.os2.beta,comp.os.os2.utilities,comp.os.os2.programmer.misc

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comp.os.os2.utilities:157 comp.os.os2.programmer.misc:2072
From: Jonathan de Boyne Pollard <J.deBoynePollard-newsgroups@NTLWorld.COM>

> And what do you think about sector-mode of HPFS ? Is it also not any 
> use at all because it is not independent of filesystem format ?
>

It's certainly not desirable.  I'd much prefer everything to use the 
"new" (if something from 1999 can be called that any more) OS/2 4.5 
"raw" paradigm where possible.  Open with DosOpenL, seek around with 
DosSetFilePtrL, and read and write with DosRead/DosWrite.  No magic 
filesystem-specific FSCtls or IOCtls at all.

> I think, you'd better make an abstraction layer for an unified access 
> to the volume using DASD.
>

I *have* an abstraction layer.  That's why filesystem-specific bodges 
are undesirable.  The abstraction layer has no knowledge of filesystem 
format, and it's a godawful bodge to put it in, especially when it's 
clear from the Toolkit doco that OS/2 4.5 was aiming for a nice clean 
universal interface free from filesystem-specific bodges.

>> How close are you to making ordinary sector-level access with 
>> DosSetFilePtr/DosRead/DosWrite just work as it ought?
>>
> If you read all the threads, you coulud know that 
> DosSetFilePtr()/DosRead() worked as expected, but DosWrite().
>

No, they *do not* work as expected.  (And there was no thread from 2005 
that actually stated otherwise.  Indeed, we have you yourself saying 
that "I don't know what the cause is." and "HPFS386 also has a similar 
problem." and "I'll look into [it] more.".)  DosSetFilePtr() still 
returns ERROR_SEEK, just as it did in 2005.  It's returning ERROR_SEEK 
for Mark Dodel, and it's returning ERROR_SEEK for Andy WIllis.  They've 
both independently sent me logs showing this.  (I instrumented CHKVOL to 
print out the return code from the system call.)  Andy Willis has also 
kindly tested DosSetFilePtrL and that returns ERROR_SEEK too.  Working 
on the assumption that they both have the latest release of the FAT32 
filesystem driver, which I have no reason to doubt, this problem has 
*not* been fixed and the calls do *not* work as they ought to.  And we 
even have you stating that HPFS386.IFS, also lacking the FS_CHGFILEPTRL 
entrypoint, has the same problem.

Mark Dodel has confirmed that this is FAT32.IFS causing this, by the 
simple expedient of disabling the filesystem driver and using CHKVOL 
/FS:FAT, which uses the same access method for reading/writing the 
volume contents (it being filesystem-agnostic and all).  That worked, he 
told me.  DosSetFilePtr() didn't return ERROR_SEEK.  And Allan Holm has 
provided a useful datum, since he has managed to get things to work with 
the FAT32.IFS driver installed, but on a ~4GiB volume.


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