9af5dd68e4
we intend for the user to be able to unload them later via kldunload(2) instead of calling linker_load_module() and then directly adjusting the ref count on the linker file structure. This makes the resulting consumer code simpler and cleaner and better hides the linker internals making it possible to sanely lock the linker.
304 lines
8.6 KiB
C
304 lines
8.6 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/linker.h>
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#include <sys/mount.h>
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#include <sys/proc.h>
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#include <sys/syscallsubr.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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static int vfs_register(struct vfsconf *);
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static int vfs_unregister(struct vfsconf *);
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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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* A Zen vnode attribute structure.
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*
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* Initialized when the first filesystem registers by vfs_register().
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*/
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struct vattr va_null;
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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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/*
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* Routines having to do with the management of the vnode table.
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*/
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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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if (!strcmp(name, "ffs"))
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name = "ufs";
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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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struct vfsconf *
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vfs_byname_kld(const char *fstype, struct thread *td, int *error)
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{
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struct vfsconf *vfsp;
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int fileid;
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vfsp = vfs_byname(fstype);
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if (vfsp != NULL)
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return (vfsp);
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/* Only load modules for root (very important!). */
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*error = suser(td);
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if (*error)
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return (NULL);
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*error = securelevel_gt(td->td_ucred, 0);
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if (*error)
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return (NULL);
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*error = kern_kldload(td, fstype, &fileid);
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if (*error)
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return (NULL);
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/* Look up again to see if the VFS was loaded. */
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vfsp = vfs_byname(fstype);
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if (vfsp == NULL) {
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(void)kern_kldunload(td, fileid, LINKER_UNLOAD_FORCE);
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*error = ENODEV;
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return (NULL);
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}
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return (vfsp);
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}
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/* Register a new filesystem type in the global table */
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static 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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static int once;
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if (!once) {
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vattr_null(&va_null);
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once = 1;
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}
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if (vfc->vfc_version != VFS_VERSION) {
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printf("ERROR: filesystem %s, unsupported ABI version %x\n",
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vfc->vfc_name, vfc->vfc_version);
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return (EINVAL);
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}
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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,
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("Filesystem %s has no 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_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)
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/* convert an inode number to a vnode */
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vfsops->vfs_vget = vfs_stdvget;
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if (vfsops->vfs_fhtovp == NULL)
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/* turn an NFS file handle into a vnode */
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vfsops->vfs_fhtovp = vfs_stdfhtovp;
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if (vfsops->vfs_checkexp == NULL)
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/* check if file system is exported */
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vfsops->vfs_checkexp = vfs_stdcheckexp;
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if (vfsops->vfs_vptofh == NULL)
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/* turn a vnode into an NFS file handle */
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vfsops->vfs_vptofh = vfs_stdvptofh;
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if (vfsops->vfs_init == NULL)
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/* file system specific initialisation */
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vfsops->vfs_init = vfs_stdinit;
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if (vfsops->vfs_uninit == NULL)
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/* file system specific uninitialisation */
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vfsops->vfs_uninit = vfs_stduninit;
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if (vfsops->vfs_extattrctl == NULL)
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/* extended attribute control */
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vfsops->vfs_extattrctl = vfs_stdextattrctl;
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if (vfsops->vfs_sysctl == NULL)
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vfsops->vfs_sysctl = vfs_stdsysctl;
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/*
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* Call init function for this VFS...
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*/
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(*(vfc->vfc_vfsops->vfs_init))(vfc);
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return 0;
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}
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/* Remove registration of a filesystem type */
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static int
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vfs_unregister(struct vfsconf *vfc)
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{
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struct vfsconf *vfsp;
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int error, i, maxtypenum;
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i = vfc->vfc_typenum;
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vfsp = vfs_byname(vfc->vfc_name);
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if (vfsp == NULL)
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return EINVAL;
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if (vfsp->vfc_refcount)
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return EBUSY;
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if (vfc->vfc_vfsops->vfs_uninit != NULL) {
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error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp);
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if (error)
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return (error);
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}
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TAILQ_REMOVE(&vfsconf, vfsp, vfc_list);
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maxtypenum = VFS_GENERIC;
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TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
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if (maxtypenum < vfsp->vfc_typenum)
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maxtypenum = vfsp->vfc_typenum;
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maxvfsconf = maxtypenum + 1;
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return 0;
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}
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/*
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* Standard kernel module handling code for filesystem modules.
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* Referenced from VFS_SET().
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*/
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int
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vfs_modevent(module_t mod, int type, void *data)
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{
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struct vfsconf *vfc;
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int error = 0;
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vfc = (struct vfsconf *)data;
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switch (type) {
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case MOD_LOAD:
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if (vfc)
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error = vfs_register(vfc);
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break;
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case MOD_UNLOAD:
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if (vfc)
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error = vfs_unregister(vfc);
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break;
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default:
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error = EOPNOTSUPP;
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break;
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}
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return (error);
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}
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