Introduce vfs_byname() function to find things on it. Staticize vfs_nmount() function under the name vfs_donmount(). Various cleanups.
531 lines
16 KiB
C
531 lines
16 KiB
C
/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed
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* to Berkeley by John Heidemann of the UCLA Ficus project.
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*
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* Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)vfs_init.c 8.3 (Berkeley) 1/4/94
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/mount.h>
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#include <sys/sysctl.h>
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#include <sys/vnode.h>
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#include <sys/malloc.h>
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MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes");
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/*
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* The highest defined VFS number.
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*/
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int maxvfsconf = VFS_GENERIC + 1;
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/*
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* Single-linked list of configured VFSes.
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* New entries are added/deleted by vfs_register()/vfs_unregister()
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*/
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struct vfsconfhead vfsconf = TAILQ_HEAD_INITIALIZER(vfsconf);
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/*
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* vfs_init.c
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*
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* Allocate and fill in operations vectors.
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*
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* An undocumented feature of this approach to defining operations is that
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* there can be multiple entries in vfs_opv_descs for the same operations
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* vector. This allows third parties to extend the set of operations
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* supported by another layer in a binary compatibile way. For example,
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* assume that NFS needed to be modified to support Ficus. NFS has an entry
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* (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by
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* default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions)
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* listing those new operations Ficus adds to NFS, all without modifying the
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* NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but
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* that is a(whole)nother story.) This is a feature.
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*/
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/* Table of known vnodeop vectors (list of VFS vnode vectors) */
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static const struct vnodeopv_desc **vnodeopv_descs;
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static int vnodeopv_num;
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/* Table of known descs (list of vnode op handlers "vop_access_desc") */
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static struct vnodeop_desc **vfs_op_descs;
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/* Reference counts for vfs_op_descs */
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static int *vfs_op_desc_refs;
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/* Number of descriptions */
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static int num_op_descs;
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/* Number of entries in each description */
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static int vfs_opv_numops = 64;
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/* Allow this number to be tuned at boot */
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TUNABLE_INT("vfs.opv_numops", &vfs_opv_numops);
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SYSCTL_INT(_vfs, OID_AUTO, opv_numops, CTLFLAG_RDTUN, &vfs_opv_numops,
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0, "Maximum number of operations in vop_t vector");
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static int int_cmp(const void *a, const void *b);
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static int
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int_cmp(const void *a, const void *b)
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{
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return(*(const int *)a - *(const int *)b);
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}
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/*
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* Recalculate the operations vector/description (those parts of it that can
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* be recalculated, that is.)
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* Always allocate operations vector large enough to hold vfs_opv_numops
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* entries. The vector is never freed or deallocated once it is initialized,
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* so that vnodes might safely reference it through their v_op pointer without
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* vector changing suddenly from under them.
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*/
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static void
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vfs_opv_recalc(void)
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{
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int i, j, k;
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int *vfs_op_offsets;
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vop_t ***opv_desc_vector_p;
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vop_t **opv_desc_vector;
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struct vnodeopv_entry_desc *opve_descp;
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const struct vnodeopv_desc *opv;
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if (vfs_op_descs == NULL)
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panic("vfs_opv_recalc called with null vfs_op_descs");
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/*
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* Allocate and initialize temporary array to store
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* offsets. Sort it to put all uninitialized entries
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* first and to make holes in existing offset sequence
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* detectable.
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*/
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MALLOC(vfs_op_offsets, int *,
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num_op_descs * sizeof(int), M_TEMP, M_WAITOK);
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if (vfs_op_offsets == NULL)
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panic("vfs_opv_recalc: no memory");
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for (i = 0; i < num_op_descs; i++)
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vfs_op_offsets[i] = vfs_op_descs[i]->vdesc_offset;
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qsort(vfs_op_offsets, num_op_descs, sizeof(int), int_cmp);
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/*
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* Run through and make sure all known descs have an offset.
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* Use vfs_op_offsets to locate holes in offset sequence and
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* reuse them.
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* vop_default_desc is hardwired at offset 1, and offset 0
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* is a panic sanity check.
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*/
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j = 1; k = 1;
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for (i = 0; i < num_op_descs; i++) {
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if (vfs_op_descs[i]->vdesc_offset != 0)
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continue;
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/*
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* Look at two adjacent entries vfs_op_offsets[j - 1] and
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* vfs_op_offsets[j] and see if we can fit a new offset
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* number in between. If not, look at the next pair until
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* hole is found or the end of the vfs_op_offsets vector is
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* reached. j has been initialized to 1 above so that
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* referencing (j-1)-th element is safe and the loop will
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* never execute if num_op_descs is 1. For each new value s
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* of i the j loop pick up from where previous iteration has
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* left off. When the last hole has been consumed or if no
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* hole has been found, we will start allocating new numbers
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* starting from the biggest already available offset + 1.
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*/
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for (; j < num_op_descs; j++) {
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if (vfs_op_offsets[j - 1] < k && vfs_op_offsets[j] > k)
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break;
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k = vfs_op_offsets[j] + 1;
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}
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vfs_op_descs[i]->vdesc_offset = k++;
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}
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FREE(vfs_op_offsets, M_TEMP);
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/* Panic if new vops will cause vector overflow */
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if (k > vfs_opv_numops)
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panic("VFS: Ran out of vop_t vector entries. %d entries required, only %d available.\n", k, vfs_opv_numops);
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/*
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* Allocate and fill in the vectors
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*/
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for (i = 0; i < vnodeopv_num; i++) {
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opv = vnodeopv_descs[i];
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opv_desc_vector_p = opv->opv_desc_vector_p;
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if (*opv_desc_vector_p == NULL)
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MALLOC(*opv_desc_vector_p, vop_t **,
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vfs_opv_numops * sizeof(vop_t *), M_VNODE,
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M_WAITOK | M_ZERO);
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/* Fill in, with slot 0 being to return EOPNOTSUPP */
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opv_desc_vector = *opv_desc_vector_p;
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opv_desc_vector[0] = (vop_t *)vop_eopnotsupp;
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for (j = 0; opv->opv_desc_ops[j].opve_op; j++) {
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opve_descp = &(opv->opv_desc_ops[j]);
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opv_desc_vector[opve_descp->opve_op->vdesc_offset] =
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opve_descp->opve_impl;
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}
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/* Replace unfilled routines with their default (slot 1). */
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opv_desc_vector = *(opv->opv_desc_vector_p);
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if (opv_desc_vector[1] == NULL)
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panic("vfs_opv_recalc: vector without a default.");
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for (j = 0; j < vfs_opv_numops; j++)
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if (opv_desc_vector[j] == NULL)
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opv_desc_vector[j] = opv_desc_vector[1];
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}
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}
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/* Add a set of vnode operations (a description) to the table above. */
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void
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vfs_add_vnodeops(const void *data)
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{
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const struct vnodeopv_desc *opv;
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const struct vnodeopv_desc **newopv;
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struct vnodeop_desc **newop;
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int *newref;
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struct vnodeop_desc *desc;
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int i, j;
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opv = (const struct vnodeopv_desc *)data;
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MALLOC(newopv, const struct vnodeopv_desc **,
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(vnodeopv_num + 1) * sizeof(*newopv), M_VNODE, M_WAITOK);
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if (vnodeopv_descs) {
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bcopy(vnodeopv_descs, newopv, vnodeopv_num * sizeof(*newopv));
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FREE(vnodeopv_descs, M_VNODE);
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}
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newopv[vnodeopv_num] = opv;
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vnodeopv_descs = newopv;
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vnodeopv_num++;
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/* See if we have turned up a new vnode op desc */
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for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) {
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for (j = 0; j < num_op_descs; j++) {
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if (desc == vfs_op_descs[j]) {
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/* found it, increase reference count */
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vfs_op_desc_refs[j]++;
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break;
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}
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}
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if (j == num_op_descs) {
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/* not found, new entry */
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MALLOC(newop, struct vnodeop_desc **,
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(num_op_descs + 1) * sizeof(*newop),
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M_VNODE, M_WAITOK);
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/* new reference count (for unload) */
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MALLOC(newref, int *,
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(num_op_descs + 1) * sizeof(*newref),
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M_VNODE, M_WAITOK);
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if (vfs_op_descs) {
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bcopy(vfs_op_descs, newop,
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num_op_descs * sizeof(*newop));
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FREE(vfs_op_descs, M_VNODE);
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}
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if (vfs_op_desc_refs) {
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bcopy(vfs_op_desc_refs, newref,
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num_op_descs * sizeof(*newref));
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FREE(vfs_op_desc_refs, M_VNODE);
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}
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newop[num_op_descs] = desc;
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newref[num_op_descs] = 1;
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vfs_op_descs = newop;
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vfs_op_desc_refs = newref;
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num_op_descs++;
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}
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}
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vfs_opv_recalc();
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}
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/* Remove a vnode type from the vnode description table above. */
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void
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vfs_rm_vnodeops(const void *data)
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{
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const struct vnodeopv_desc *opv;
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const struct vnodeopv_desc **newopv;
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struct vnodeop_desc **newop;
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int *newref;
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vop_t **opv_desc_vector;
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struct vnodeop_desc *desc;
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int i, j, k;
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opv = (const struct vnodeopv_desc *)data;
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/* Lower ref counts on descs in the table and release if zero */
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for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) {
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for (j = 0; j < num_op_descs; j++) {
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if (desc == vfs_op_descs[j]) {
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/* found it, decrease reference count */
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vfs_op_desc_refs[j]--;
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break;
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}
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}
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for (j = 0; j < num_op_descs; j++) {
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if (vfs_op_desc_refs[j] > 0)
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continue;
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if (vfs_op_desc_refs[j] < 0)
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panic("vfs_remove_vnodeops: negative refcnt");
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/* Entry is going away - replace it with defaultop */
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for (k = 0; k < vnodeopv_num; k++) {
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opv_desc_vector =
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*(vnodeopv_descs[k]->opv_desc_vector_p);
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if (opv_desc_vector != NULL)
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opv_desc_vector[desc->vdesc_offset] =
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opv_desc_vector[1];
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}
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MALLOC(newop, struct vnodeop_desc **,
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(num_op_descs - 1) * sizeof(*newop),
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M_VNODE, M_WAITOK);
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/* new reference count (for unload) */
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MALLOC(newref, int *,
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(num_op_descs - 1) * sizeof(*newref),
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M_VNODE, M_WAITOK);
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for (k = j; k < (num_op_descs - 1); k++) {
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vfs_op_descs[k] = vfs_op_descs[k + 1];
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vfs_op_desc_refs[k] = vfs_op_desc_refs[k + 1];
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}
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bcopy(vfs_op_descs, newop,
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(num_op_descs - 1) * sizeof(*newop));
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bcopy(vfs_op_desc_refs, newref,
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(num_op_descs - 1) * sizeof(*newref));
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FREE(vfs_op_descs, M_VNODE);
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FREE(vfs_op_desc_refs, M_VNODE);
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vfs_op_descs = newop;
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vfs_op_desc_refs = newref;
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num_op_descs--;
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}
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}
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for (i = 0; i < vnodeopv_num; i++) {
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if (vnodeopv_descs[i] == opv) {
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for (j = i; j < (vnodeopv_num - 1); j++)
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vnodeopv_descs[j] = vnodeopv_descs[j + 1];
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break;
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}
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}
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if (i == vnodeopv_num)
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panic("vfs_remove_vnodeops: opv not found");
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opv_desc_vector = *(opv->opv_desc_vector_p);
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if (opv_desc_vector != NULL)
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FREE(opv_desc_vector, M_VNODE);
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MALLOC(newopv, const struct vnodeopv_desc **,
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(vnodeopv_num - 1) * sizeof(*newopv), M_VNODE, M_WAITOK);
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bcopy(vnodeopv_descs, newopv, (vnodeopv_num - 1) * sizeof(*newopv));
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FREE(vnodeopv_descs, M_VNODE);
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vnodeopv_descs = newopv;
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vnodeopv_num--;
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vfs_opv_recalc();
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}
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/*
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* Routines having to do with the management of the vnode table.
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*/
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struct vattr va_null;
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struct vfsconf *
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vfs_byname(const char *name)
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{
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struct vfsconf *vfsp;
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TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
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if (!strcmp(name, vfsp->vfc_name))
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return (vfsp);
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return (NULL);
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}
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/*
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* Initialize the vnode structures and initialize each filesystem type.
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*/
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/* ARGSUSED*/
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static void
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vfsinit(void *dummy)
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{
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vattr_null(&va_null);
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}
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SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL)
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/* Register a new filesystem type in the global table */
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int
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vfs_register(struct vfsconf *vfc)
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{
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struct sysctl_oid *oidp;
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struct vfsops *vfsops;
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if (vfs_byname(vfc->vfc_name) != NULL)
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return EEXIST;
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vfc->vfc_typenum = maxvfsconf++;
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TAILQ_INSERT_TAIL(&vfsconf, vfc, vfc_list);
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/*
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* If this filesystem has a sysctl node under vfs
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* (i.e. vfs.xxfs), then change the oid number of that node to
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* match the filesystem's type number. This allows user code
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* which uses the type number to read sysctl variables defined
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* by the filesystem to continue working. Since the oids are
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* in a sorted list, we need to make sure the order is
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* preserved by re-registering the oid after modifying its
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* number.
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*/
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SLIST_FOREACH(oidp, &sysctl__vfs_children, oid_link)
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if (strcmp(oidp->oid_name, vfc->vfc_name) == 0) {
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sysctl_unregister_oid(oidp);
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oidp->oid_number = vfc->vfc_typenum;
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sysctl_register_oid(oidp);
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}
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/*
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* Initialise unused ``struct vfsops'' fields, to use
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* the vfs_std*() functions. Note, we need the mount
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* and unmount operations, at the least. The check
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* for vfsops available is just a debugging aid.
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*/
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KASSERT(vfc->vfc_vfsops != NULL,
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("Filesystem %s has no vfsops", vfc->vfc_name));
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/*
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* Check the mount and unmount operations.
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*/
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vfsops = vfc->vfc_vfsops;
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KASSERT(vfsops->vfs_mount != NULL || vfsops->vfs_nmount != NULL,
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("Filesystem %s has no (n)mount op", vfc->vfc_name));
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KASSERT(vfsops->vfs_unmount != NULL,
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("Filesystem %s has no unmount op", vfc->vfc_name));
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if (vfsops->vfs_start == NULL)
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/* make a file system operational */
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vfsops->vfs_start = vfs_stdstart;
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if (vfsops->vfs_root == NULL)
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/* return file system's root vnode */
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vfsops->vfs_root = vfs_stdroot;
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if (vfsops->vfs_quotactl == NULL)
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/* quota control */
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vfsops->vfs_quotactl = vfs_stdquotactl;
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if (vfsops->vfs_statfs == NULL)
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/* return file system's status */
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vfsops->vfs_statfs = vfs_stdstatfs;
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if (vfsops->vfs_sync == NULL)
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/*
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* flush unwritten data (nosync)
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* file systems can use vfs_stdsync
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* explicitly by setting it in the
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* vfsop vector.
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*/
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vfsops->vfs_sync = vfs_stdnosync;
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if (vfsops->vfs_vget == NULL)
|
|
/* convert an inode number to a vnode */
|
|
vfsops->vfs_vget = vfs_stdvget;
|
|
if (vfsops->vfs_fhtovp == NULL)
|
|
/* turn an NFS file handle into a vnode */
|
|
vfsops->vfs_fhtovp = vfs_stdfhtovp;
|
|
if (vfsops->vfs_checkexp == NULL)
|
|
/* check if file system is exported */
|
|
vfsops->vfs_checkexp = vfs_stdcheckexp;
|
|
if (vfsops->vfs_vptofh == NULL)
|
|
/* turn a vnode into an NFS file handle */
|
|
vfsops->vfs_vptofh = vfs_stdvptofh;
|
|
if (vfsops->vfs_init == NULL)
|
|
/* file system specific initialisation */
|
|
vfsops->vfs_init = vfs_stdinit;
|
|
if (vfsops->vfs_uninit == NULL)
|
|
/* file system specific uninitialisation */
|
|
vfsops->vfs_uninit = vfs_stduninit;
|
|
if (vfsops->vfs_extattrctl == NULL)
|
|
/* extended attribute control */
|
|
vfsops->vfs_extattrctl = vfs_stdextattrctl;
|
|
if (vfsops->vfs_sysctl == NULL)
|
|
vfsops->vfs_sysctl = vfs_stdsysctl;
|
|
|
|
/*
|
|
* Call init function for this VFS...
|
|
*/
|
|
(*(vfc->vfc_vfsops->vfs_init))(vfc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Remove registration of a filesystem type */
|
|
int
|
|
vfs_unregister(struct vfsconf *vfc)
|
|
{
|
|
struct vfsconf *vfsp;
|
|
int error, i, maxtypenum;
|
|
|
|
i = vfc->vfc_typenum;
|
|
|
|
vfsp = vfs_byname(vfc->vfc_name);
|
|
if (vfsp == NULL)
|
|
return EINVAL;
|
|
if (vfsp->vfc_refcount)
|
|
return EBUSY;
|
|
if (vfc->vfc_vfsops->vfs_uninit != NULL) {
|
|
error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp);
|
|
if (error)
|
|
return (error);
|
|
}
|
|
TAILQ_REMOVE(&vfsconf, vfsp, vfc_list);
|
|
maxtypenum = VFS_GENERIC;
|
|
TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
|
|
if (maxtypenum < vfsp->vfc_typenum)
|
|
maxtypenum = vfsp->vfc_typenum;
|
|
maxvfsconf = maxtypenum + 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Standard kernel module handling code for filesystem modules.
|
|
* Referenced from VFS_SET().
|
|
*/
|
|
int
|
|
vfs_modevent(module_t mod, int type, void *data)
|
|
{
|
|
struct vfsconf *vfc;
|
|
int error = 0;
|
|
|
|
vfc = (struct vfsconf *)data;
|
|
|
|
switch (type) {
|
|
case MOD_LOAD:
|
|
if (vfc)
|
|
error = vfs_register(vfc);
|
|
break;
|
|
|
|
case MOD_UNLOAD:
|
|
if (vfc)
|
|
error = vfs_unregister(vfc);
|
|
break;
|
|
default:
|
|
error = EOPNOTSUPP;
|
|
break;
|
|
}
|
|
return (error);
|
|
}
|