[ros-kernel] Re: XFS Filesystem?

[Phillip S. <ps...@cf...>]

Any effort to port a unix filesystem to reactos would not fit semantically 
into the OS right.  Specifically, even a unix with ACLs does not fit into 
the NT security model.  Unix ACLs still only allow specifying 
read/write/execute permissions to be set on security entities, and I doubt 
that the security identifier is more than just a 32 bit integer, which is 
not enough to represent an NT SID, which is typically 128 bits ( though it 
can be of any length ).  NTFS stores arbitrary security descriptors which 
allows it to hold current and future NT security descriptors.  NT security 
descriptors are extensible, and MS has already added capabilities to 
specify how a given ACE is to be applied: to the directory, files in the 
directory, children directories, files in those directories, or all of the 
above.  In theory it is possible to extend security descriptors to use 
mandatory access control, which is to specify to whom what permissions may 
be granted by those with rights to modify the ACL.  An inherited rights 
mask like netware has is also possible.  I'd also like to have deleted file 
salvage/purge support like netware.

In short, a unix filesystem won't port well to reactos due to differing 
semantics.  NTFS really is a very powerful and highly extensible 
filesystem, whose capabilities are not fully exploited by Microsoft's 
current OSes.  I'd like to have reactos exploit more of these capabilities, 
though with win2k it seems that MS is beginning to exploit some of them 
with things like reparse points, which allow EFS and offline files.  Named 
data streams are also used to store extra information on the file 
properties tab in explorer for the author of the file, subject, etc.  NTFS 
can even index files by such extended information instead of just the name 
of the file, as is currently done.  NTFS performance could also be much 
better than MIcrosoft's implementations: performance problems ( such as 
being prone to fragmentation ) are due to the driver, not the on disk 
filesystem.

At 09:27 AM 9/24/2001 -0700, you wrote:
>SGI's XFS filesystem is available as an Open-Source project (GPL) for
>Linux.  How difficult is it to port a Linux filesystem driver to
>ReactOS?
>
>This filesystem has journaling capabilities, and may be of benefit to
>many users.  I believe it has ACL support, as well.
>
>Thus, it may be worth consideration for a future project within
>ReactOS, if it can be ported easily enough.
>
>=====
>=======
>Frank D. Engel, Jr.
>Please note my new address: fd...@ya...

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