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Date: Wed, 2 Apr 1997 18:20:42 -0500 (EST)
From: "Peter M. Chen" <pmchen@eecs.umich.edu>
Message-Id: <199704022320.SAA19709@life.eecs.umich.edu>
To: freebsd-hackers@freebsd.org
Subject: VOP_PUTPAGES
Sender: owner-hackers@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

I feel stupid for asking this, but what does VOP_PUTPAGES call?  I tried
tracing through the maze of macros but ended up at vp->v_op[0], which I
think is an error function.

VOP_PUTPAGES (kern/vnode_if.h) calls
    VCALL(vp, VOFFSET(vop_putpages), &a)

    which becomes
    VOCALL(vp->v_op, VOFFSET(vop_putpages),&a)

    which becomes
    ( *(vp->v_op[VOFFSET(vop_putpages)])) (&a)

    which becomes
    ( *(vp->v_op[((&vop_putpages_desc)->vdesc_offset) ])) (&a)

    which becomes
    ( *(vp->v_op[0])) (&a)

I'm interested in the paging out behavior of files.  E.g. a file block that
has been mmap'ed and dirtied needs to be written back to its file.

Thanks,
  Pete