[ros-dev] IFS wrapper project proposal draft

Tue Apr 5 10:57:32 UTC 2011

AFAIK only NTFS has this root; JFS has been around for a while in the AIX  
systems. It was ported to OS/2 Warp 4.5 later on.

Well at least they're both better than all that  
ext1/ext2/ext3/ext4/extπ/whatever gibberish. The biggest problem is (and  
it has actually happened to me before) these guys can run out of "inodes"  
and what not.

On Tue, 05 Apr 2011 19:40:09 +1000, Love Nystrom <love.nystrom at gmail.com>  
wrote:

> Hi Adam,
>
> Thanks for the pointer.
> JFS may be a viable alternative to NTFS indeed, they probably have the  
> same
> root (HPFS)?
>
> The bulk of porting it to ReactOS will probably be "un-porting" it's  
> Linux
> kernel dependency patches.
> I'm fetching the whole CVS repository from SourceForge right now, but I'm
> not sure when
> I will get the time to start eyeballing it .. I should be doing RL stuff
> today but find my butt
> glued to the chair again
> (Water_stoppage==Shower_impossible==I_refuse_to_go_public)!
>
> Peace
> // Love
>
> On Tue, Apr 5, 2011 at 3:02 PM, Adam <geekdundee at gmail.com> wrote:
>
>> I would also recommend looking at porting JFS - the sources are  
>> available.
>> This is the file system that IBM originally used in OS/2 Warp 4.5X (and  
>> also
>> AIX if I am not mistaken) and is a very solid file system. Something IBM
>> seemed to be doing right.
>>
>> I am not sure about all the details of it, but AFAIK it also supports
>> things like ACLs too.
>>
>>
>> On Tue, 05 Apr 2011 17:56:40 +1000, Love Nystrom  
>> <love.nystrom at gmail.com>
>> wrote:
>>
>>  Hi Bryan,
>>>
>>> Just like Aleksey, I would welcome an effort to simplify IFS
>>> implementation.
>>>
>>> Seen as NTFS is (and always will be?) not well documented, I've been
>>> thinking about
>>> supporting some alternative, OSS, journaling file system in ReactOS,  
>>> e.g.
>>> ReiserFS,
>>> to allow us to provide the (relative) fail-safety of file transaction
>>> journaling that NTFS has.
>>> Also, hopefully, to enable us to implement NT's access privilege
>>> system (Security) on files.
>>>
>>> So far, it remains just a thought, since I can't allocate the time to
>>> adapt
>>> e.g ReiserFS to
>>> an NT IFS, and if I'm not mistaken, our IFS implementation has
>>> shortcomings
>>> of it's own
>>> which You may need to address as well in implementing Your proposal.
>>>
>>> In addition to "Windows NT File System Internals" I would also  
>>> recommend
>>> "Windows Internals, 4th Edition" for additional/complementary insight.
>>> Especially Ch.12 "File Systems", but Ch.8-12 are all relevant, and the
>>> whole
>>> book is strongly recommended (by everyone, I think).
>>>
>>> It will be a BIG job I think (thesis big), and I hope You have the
>>> structural
>>> "common sense" to make it a success, and not a mess ;).
>>> It would be most welcome !
>>>
>>> Comment Your code scrupulously :)
>>>
>>> Best Regards
>>> // Love
>>>
>>> On Sun, Apr 3, 2011 at 1:55 PM, <ros-dev-request at reactos.org> wrote:
>>>
>>>  ---------- Forwarded message ----------
>>>> From: Bryan Donlan <bdonlan at gmail.com>
>>>> To: ReactOS Development List <ros-dev at reactos.org>
>>>> Date: Sat, 2 Apr 2011 18:26:23 -0400
>>>> Subject: [ros-dev] [GSoC] IFS wrapper project proposal draft
>>>> Hello,
>>>>
>>>> After reading the ReactOS GSoC ideas page, I became interested in the
>>>> IFS wrapper driver project idea[1], and would appreciate any comments
>>>> on my project proposal before I formally submit it.
>>>>
>>>> First, a bit about me. I am a student in a dual-major program,
>>>> studying Computer Science and Japanese at the University of
>>>> Massachusetts at Amherst. I have had some experience in kernel
>>>> development previously; as part of an internship at a research project
>>>> at my University, I wrote some network flow analysis code running in
>>>> the Linux kernel. While filesystem work will be a first for me, I
>>>> think it will be an interesting leaning experience. I am fluent in
>>>> English and Japanese, and am in the UTC-0400 timezone (TZ=US/Eastern).
>>>> My freenode username is bd_, and my myReactOS username is bdonlan.
>>>>
>>>> In preparation for writing this proposal, I obtained a copy of the
>>>> "Windows NT File System Internals: A Developer's Guide" book from
>>>> O'Reilly. Although a bit dated, it has been enourmously helpful in
>>>> helping me get an idea of what I'm getting into.
>>>>
>>>> My goal in this project will be to write a library to significantly
>>>> simplify writing a NT File System Driver. Although writing a
>>>> kernel-mode filesystem will never be as easy as with, eg, FUSE, it
>>>> should be possible to abstract away many of the idiosyncracies of the
>>>> NT filesystem API, at least. For example, the wrapper library may
>>>> handle:
>>>> * Automatically queueing asynchronous filesystem operations on a  
>>>> worker
>>>> thread
>>>> * Parsing paths and invoking a FS-supplied traversal function for each
>>>> directory element
>>>> * Interfacing with the NT cache manager, including flushing data from
>>>> the cache when a non-cached operation is performed on a cached file,
>>>> and establishing cache maps for the underlying device for a disk-based
>>>> file system
>>>> * Providing a common implementation of byte range locks and oplocks,
>>>> and disabling fast I/O when they are in use
>>>> * Caching directory entry lookups
>>>> * Performing typical input validation/security checks needed by all NT
>>>> filesystems
>>>> * Helper tools may also be provided to load pseudo-filesystems
>>>> (filesystems with neither network nor disk backing) on an ad-hoc basis
>>>>
>>>> Essentially, the library should make it easy for the filesystem
>>>> designer to focus on the actual filesystem, rather than the NT IFS
>>>> interfaces - a read call would be able to skip all the preparation and
>>>> checks, and directly go to perform the actual I/O.
>>>>
>>>> Major milestones for the project may include:
>>>> - Prepare a sketch of the API and callbacks for the IFS helper library
>>>> (subject to change if necessary)
>>>> - Implement enough of the wrapper library to implement a simple
>>>> pseudo-filesystem demonstrating non-cached reads and writes
>>>> - Add support for cached reads/writes (interaction with the cache
>>>> manager, caching for on-disk metadata)
>>>> - Demonstrate a disk-based filesystem without metadata update support
>>>> (MINIX FS or FAT?)
>>>> - Demonstrate a disk-based filesystem with full read-write support
>>>> - If time allows, add support for ancillary features, such as byte
>>>> locks, oplocks, and notify watchers.
>>>>
>>>> The interfaces exposed by the filesystem library will of course be
>>>> clearly documented. Filesystems needing more advanced support will
>>>> also be able to override any IFS callbacks they choose.
>>>>
>>>> I have an existing consulting commitment that will take some of my
>>>> time, but I expect to be able to put in 20-30 hours of work per week
>>>> into this project. Further, I hereby swear that I have not used nor
>>>> seen the source code to any version of the Windows operating system
>>>> nor any Microsoft product that may be related to the proposed project
>>>> that is under a license incompatible with contribution to ReactOS,
>>>> including but not limited to the leaked Windows 2000 source code and
>>>> the Windows Research Kernel.
>>>>
>>>> I would appreciate any comments on my proposal before formally
>>>> submitting it to the GSoC site.
>>>>
>>>> Thanks,
>>>>
>>>> Bryan Donlan
>>>>
>>>>
>>>>
>>
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