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From: web@farpoint.austin.ibm.com (Bill Baker)
Newsgroups: comp.unix.aix
Subject: Re: vn_ routines
Message-ID: <5866@awdprime.UUCP>
Date: 12 Mar 91 21:46:15 GMT
References: <1991Mar8.002636.4940@nmt.edu>
Sender: news@awdprime.UUCP
Organization: IBM AWD, Austin
Lines: 29

>Does anyone know where all the vn_ routines are kept? Only two of them are
>described as "kernel services", the rest are all "subroutines". But ld can't
>find them in the standard libraries, and despite doing "ar t" on all the .a
>files in /lib and /usr/lib, none of them show up anywhere.

>Ruth Milner
>Systems Manager                     NRAO/VLA                    Socorro NM
>                            rmilner@zia.aoc.nrao.edu

My apologies for the confusing documentation.  The vn_ routines described
in the documentation are an attempt to define the entry points for a new file
system type that you would write.  For example, if you were writing a dos
file system to run in AIX, you would have to define routines like dos_rdwr,
dos_rele, dos_lookup, and so on.  These routines would be called from the
AIX logical file system via a pointer in the vnode.

If you want to do file system I/O from a kernel extension, I'd recommend
the fp_ interfaces.  They roughly correspond to the system calls.  These
are only callable from a kernel extension.  If you're writing applications,
you're stuck with the system call interfaces (normal read, write, ...).

Hope it helps,
web

-- 
Bill Baker             Internet: web@glasnost.austin.ibm.com
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