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/* $OpenBSD: vfs_init.c,v 1.23 2008/05/16 17:45:37 thib Exp $ */
/* $NetBSD: vfs_init.c,v 1.6 1996/02/09 19:00:58 christos Exp $ */
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed
* to Berkeley by John Heidemann of the UCLA Ficus project.
*
* Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_init.c 8.3 (Berkeley) 1/4/94
*/
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/namei.h>
#include <sys/ucred.h>
#include <sys/buf.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/systm.h>
/* a list of lists of vnodeops defns */
extern struct vnodeopv_desc *vfs_opv_descs[];
/* and the operations they perform */
extern struct vnodeop_desc *vfs_op_descs[];
struct pool namei_pool;
/*
* This code doesn't work if the defn is **vnodop_defns with cc.
* The problem is because of the compiler sometimes putting in an
* extra level of indirection for arrays. It's an interesting
* "feature" of C.
*/
int vfs_opv_numops;
typedef int (*PFI)(void *);
/*
* vfs_init.c
*
* Allocate and fill in operations vectors.
*
* An undocumented feature of this approach to defining operations is that
* there can be multiple entries in vfs_opv_descs for the same operations
* vector. This allows third parties to extend the set of operations
* supported by another layer in a binary compatibile way. For example,
* assume that NFS needed to be modified to support Ficus. NFS has an entry
* (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by
* default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions)
* listing those new operations Ficus adds to NFS, all without modifying the
* NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but
* that is a(whole)nother story.) This is a feature.
*/
/*
* Allocate and init the vector, if it needs it.
* Also handle backwards compatibility.
*/
void
vfs_opv_init_explicit(struct vnodeopv_desc *vfs_opv_desc)
{
int (**opv_desc_vector)(void *);
struct vnodeopv_entry_desc *opve_descp;
opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
if (opv_desc_vector == NULL) {
/* XXX - shouldn't be M_VNODE */
opv_desc_vector = malloc(vfs_opv_numops * sizeof(PFI),
M_VNODE, M_WAITOK|M_ZERO);
*(vfs_opv_desc->opv_desc_vector_p) = opv_desc_vector;
}
for (opve_descp = vfs_opv_desc->opv_desc_ops;
opve_descp->opve_op; opve_descp++) {
/*
* Sanity check: is this operation listed
* in the list of operations? We check this
* by seeing if its offset is zero. Since
* the default routine should always be listed
* first, it should be the only one with a zero
* offset. Any other operation with a zero
* offset is probably not listed in
* vfs_op_descs, and so is probably an error.
*
* A panic here means the layer programmer
* has committed the all-too common bug
* of adding a new operation to the layer's
* list of vnode operations but
* not adding the operation to the system-wide
* list of supported operations.
*/
if (opve_descp->opve_op->vdesc_offset == 0 &&
opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) {
printf("operation %s not listed in %s.\n",
opve_descp->opve_op->vdesc_name, "vfs_op_descs");
panic ("vfs_opv_init: bad operation");
}
/*
* Fill in this entry.
*/
opv_desc_vector[opve_descp->opve_op->vdesc_offset] =
opve_descp->opve_impl;
}
}
void
vfs_opv_init_default(struct vnodeopv_desc *vfs_opv_desc)
{
int j;
int (**opv_desc_vector)(void *);
opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
/*
* Force every operations vector to have a default routine.
*/
if (opv_desc_vector[VOFFSET(vop_default)] == NULL)
panic("vfs_opv_init: operation vector without default routine.");
for (j = 0; j < vfs_opv_numops; j++)
if (opv_desc_vector[j] == NULL)
opv_desc_vector[j] =
opv_desc_vector[VOFFSET(vop_default)];
}
/* Initialize known vnode operations vectors. */
void
vfs_op_init(void)
{
int i;
/* Set all vnode vectors to a well known value. */
for (i = 0; vfs_opv_descs[i]; i++)
*(vfs_opv_descs[i]->opv_desc_vector_p) = NULL;
/*
* Figure out how many ops there are by counting the table,
* and assign each its offset.
*/
for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) {
vfs_op_descs[i]->vdesc_offset = vfs_opv_numops;
vfs_opv_numops++;
}
/* Allocate the dynamic vectors and fill them in. */
for (i = 0; vfs_opv_descs[i]; i++)
vfs_opv_init_explicit(vfs_opv_descs[i]);
/*
* Finally, go back and replace unfilled routines
* with their default.
*/
for (i = 0; vfs_opv_descs[i]; i++)
vfs_opv_init_default(vfs_opv_descs[i]);
}
/*
* Initialize the vnode structures and initialize each file system type.
*/
void
vfsinit(void)
{
int i;
struct vfsconf *vfsconflist;
int vfsconflistlen;
pool_init(&namei_pool, MAXPATHLEN, 0, 0, 0, "namei",
&pool_allocator_nointr);
/*
* Initialize the vnode table
*/
vntblinit();
/*
* Initialize the vnode name cache
*/
nchinit();
/*
* Build vnode operation vectors.
*/
vfs_op_init();
/*
* Stop using vfsconf and maxvfsconf as a temporary storage,
* set them to their correct values now.
*/
vfsconflist = vfsconf;
vfsconflistlen = maxvfsconf;
vfsconf = NULL;
maxvfsconf = 0;
for (i = 0; i < vfsconflistlen; i++)
vfs_register(&vfsconflist[i]);
}
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