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mirror of https://git.FreeBSD.org/src.git synced 2024-12-22 11:17:19 +00:00
freebsd/sys/kern/vfs_init.c
1997-10-26 20:26:33 +00:00

269 lines
8.2 KiB
C

/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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
* $Id: vfs_init.c,v 1.30 1997/10/16 10:47:57 phk Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <vm/vm_zone.h>
static void vfs_op_init __P((void));
static void vfsinit __P((void *));
SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL)
MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes");
/*
* Sigh, such primitive tools are these...
*/
#if 0
#define DODEBUG(A) A
#else
#define DODEBUG(A)
#endif
struct vfsconf void_vfsconf;
extern struct linker_set vfs_opv_descs_;
#define vfs_opv_descs ((struct vnodeopv_desc **)vfs_opv_descs_.ls_items)
extern struct linker_set vfs_set;
extern struct vnodeop_desc *vfs_op_descs[];
/* and the operations they perform */
/*
* Zone for namei
*/
struct vm_zone *namei_zone;
/*
* 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.
*
* Without an explicit reserve area, however, you must replace vnode_if.c
* and vnode_if.h when you do this, or you will be derefrencing of the
* end of vfs_op_descs[]. This is a flaw in the use of a structure
* pointer array rather than an agregate to define vfs_op_descs. So
* it's not a very dynamic "feature".
*/
void
vfs_opv_init(struct vnodeopv_desc **them)
{
int i, j, k;
vop_t ***opv_desc_vector_p;
vop_t **opv_desc_vector;
struct vnodeopv_entry_desc *opve_descp;
/*
* Allocate the dynamic vectors and fill them in.
*/
for (i=0; them[i]; i++) {
opv_desc_vector_p = them[i]->opv_desc_vector_p;
/*
* Allocate and init the vector, if it needs it.
* Also handle backwards compatibility.
*/
if (*opv_desc_vector_p == NULL) {
/* XXX - shouldn't be M_VNODE */
MALLOC(*opv_desc_vector_p, vop_t **,
vfs_opv_numops * sizeof(vop_t *), M_VNODE,
M_WAITOK);
bzero(*opv_desc_vector_p,
vfs_opv_numops * sizeof(vop_t *));
DODEBUG(printf("vector at %x allocated\n",
opv_desc_vector_p));
}
opv_desc_vector = *opv_desc_vector_p;
for (j=0; them[i]->opv_desc_ops[j].opve_op; j++) {
opve_descp = &(them[i]->opv_desc_ops[j]);
/*
* Sanity check: is this operation listed
* in the list of operations? We check this
* by seeing if its offest 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;
}
}
/*
* Finally, go back and replace unfilled routines
* with their default. (Sigh, an O(n^3) algorithm. I
* could make it better, but that'd be work, and n is small.)
*/
for (i = 0; them[i]; i++) {
opv_desc_vector = *(them[i]->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 (k = 0; k<vfs_opv_numops; k++)
if (opv_desc_vector[k] == NULL)
opv_desc_vector[k] =
opv_desc_vector[VOFFSET(vop_default)];
}
}
/*
* Initialize known vnode operations vectors.
*/
static void
vfs_op_init()
{
int i;
DODEBUG(printf("Vnode_interface_init.\n"));
DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops));
/*
* 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;
/*
* assign each op to its offset
*
* XXX This should not be needed, but is because the per
* XXX FS ops tables are not sorted according to the
* XXX vnodeop_desc's offset in vfs_op_descs. This
* XXX is the same reason we have to take the hit for
* XXX the static inline function calls instead of using
* XXX simple macro references.
*/
for (i = 0; i < vfs_opv_numops; i++)
vfs_op_descs[i]->vdesc_offset = i;
}
/*
* Routines having to do with the management of the vnode table.
*/
extern struct vnodeops dead_vnodeops;
extern struct vnodeops spec_vnodeops;
struct vattr va_null;
/*
* Initialize the vnode structures and initialize each file system type.
*/
/* ARGSUSED*/
static void
vfsinit(dummy)
void *dummy;
{
struct vfsconf **vfc;
int maxtypenum;
namei_zone = zinit("NAMEI", MAXPATHLEN, 0, 0, 2);
/*
* Initialize the vnode table
*/
vntblinit();
/*
* Initialize the vnode name cache
*/
nchinit();
/*
* Build vnode operation vectors.
*/
vfs_op_init();
vfs_opv_init(vfs_opv_descs); /* finish the job */
/*
* Initialize each file system type.
*/
vattr_null(&va_null);
maxtypenum = 0;
vfc = (struct vfsconf **)vfs_set.ls_items;
vfsconf = *vfc; /* simulate Lite2 vfsconf array */
while (*vfc) {
struct vfsconf *vfsp = *vfc;
vfc++;
vfsp->vfc_next = *vfc;
if (maxtypenum <= vfsp->vfc_typenum)
maxtypenum = vfsp->vfc_typenum + 1;
(*vfsp->vfc_vfsops->vfs_init)(vfsp);
}
/* next vfc_typenum to be used */
maxvfsconf = maxtypenum;
}