vfs_init.c revision 91690
11541Srgrimes/* 21541Srgrimes * Copyright (c) 1989, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * This code is derived from software contributed 61541Srgrimes * to Berkeley by John Heidemann of the UCLA Ficus project. 71541Srgrimes * 81541Srgrimes * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 91541Srgrimes * 101541Srgrimes * Redistribution and use in source and binary forms, with or without 111541Srgrimes * modification, are permitted provided that the following conditions 121541Srgrimes * are met: 131541Srgrimes * 1. Redistributions of source code must retain the above copyright 141541Srgrimes * notice, this list of conditions and the following disclaimer. 151541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 161541Srgrimes * notice, this list of conditions and the following disclaimer in the 171541Srgrimes * documentation and/or other materials provided with the distribution. 181541Srgrimes * 3. All advertising materials mentioning features or use of this software 191541Srgrimes * must display the following acknowledgement: 201541Srgrimes * This product includes software developed by the University of 211541Srgrimes * California, Berkeley and its contributors. 221541Srgrimes * 4. Neither the name of the University nor the names of its contributors 231541Srgrimes * may be used to endorse or promote products derived from this software 241541Srgrimes * without specific prior written permission. 251541Srgrimes * 261541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 271541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 281541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 291541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 301541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 311541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 321541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 331541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 341541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 351541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 361541Srgrimes * SUCH DAMAGE. 371541Srgrimes * 381541Srgrimes * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 3950477Speter * $FreeBSD: head/sys/kern/vfs_init.c 91690 2002-03-05 15:38:49Z eivind $ 401541Srgrimes */ 411541Srgrimes 421541Srgrimes 431541Srgrimes#include <sys/param.h> 442112Swollman#include <sys/systm.h> 452946Swollman#include <sys/kernel.h> 461541Srgrimes#include <sys/mount.h> 4738869Sbde#include <sys/sysctl.h> 481541Srgrimes#include <sys/vnode.h> 491541Srgrimes#include <sys/malloc.h> 5029653Sdyson#include <vm/vm_zone.h> 511541Srgrimes 5212577Sbde 5330354SphkMALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes"); 5430354Sphk 5510358Sjulian/* 5669664Speter * The highest defined VFS number. 5729653Sdyson */ 5869664Speterint maxvfsconf = VFS_GENERIC + 1; 5991690Seivind 6091690Seivind/* 6191690Seivind * Single-linked list of configured VFSes. 6291690Seivind * New entries are added/deleted by vfs_register()/vfs_unregister() 6391690Seivind */ 6452780Smsmithstruct vfsconf *vfsconf; 6552780Smsmith 6652780Smsmith/* 671541Srgrimes * vfs_init.c 681541Srgrimes * 691541Srgrimes * Allocate and fill in operations vectors. 701541Srgrimes * 711541Srgrimes * An undocumented feature of this approach to defining operations is that 721541Srgrimes * there can be multiple entries in vfs_opv_descs for the same operations 731541Srgrimes * vector. This allows third parties to extend the set of operations 741541Srgrimes * supported by another layer in a binary compatibile way. For example, 751541Srgrimes * assume that NFS needed to be modified to support Ficus. NFS has an entry 761541Srgrimes * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 771541Srgrimes * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 781541Srgrimes * listing those new operations Ficus adds to NFS, all without modifying the 791541Srgrimes * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 801541Srgrimes * that is a(whole)nother story.) This is a feature. 811541Srgrimes */ 8241056Speter 8341056Speter/* Table of known vnodeop vectors (list of VFS vnode vectors) */ 8443311Sdillonstatic const struct vnodeopv_desc **vnodeopv_descs; 8541056Speterstatic int vnodeopv_num; 8641056Speter 8741056Speter/* Table of known descs (list of vnode op handlers "vop_access_desc") */ 8841056Speterstatic struct vnodeop_desc **vfs_op_descs; 8991690Seivind/* Reference counts for vfs_op_descs */ 9091690Seivindstatic int *vfs_op_desc_refs; 9191690Seivind/* Number of descriptions */ 9241056Speterstatic int num_op_descs; 9391690Seivind/* Number of entries in each description */ 9441056Speterstatic int vfs_opv_numops; 9541056Speter 9691690Seivind/* 9791690Seivind * Recalculate the operations vector/description (those parts of it that can 9891690Seivind * be recalculated, that is.) 9991690Seivind * XXX It may be preferable to replace this function with an invariant check 10091690Seivind * and a set of functions that should keep the table invariant. 10191690Seivind */ 10241056Speterstatic void 10341056Spetervfs_opv_recalc(void) 1041541Srgrimes{ 10541056Speter int i, j; 10612158Sbde vop_t ***opv_desc_vector_p; 10712158Sbde vop_t **opv_desc_vector; 1081541Srgrimes struct vnodeopv_entry_desc *opve_descp; 10943311Sdillon const struct vnodeopv_desc *opv; 1101541Srgrimes 11141056Speter if (vfs_op_descs == NULL) 11241056Speter panic("vfs_opv_recalc called with null vfs_op_descs"); 11341056Speter 1141541Srgrimes /* 11541056Speter * Run through and make sure all known descs have an offset 11641056Speter * 11741056Speter * vop_default_desc is hardwired at offset 1, and offset 0 11841056Speter * is a panic sanity check. 1191541Srgrimes */ 12041056Speter vfs_opv_numops = 0; 12141056Speter for (i = 0; i < num_op_descs; i++) 12241056Speter if (vfs_opv_numops < (vfs_op_descs[i]->vdesc_offset + 1)) 12341056Speter vfs_opv_numops = vfs_op_descs[i]->vdesc_offset + 1; 12441056Speter for (i = 0; i < num_op_descs; i++) 12541056Speter if (vfs_op_descs[i]->vdesc_offset == 0) 12641056Speter vfs_op_descs[i]->vdesc_offset = vfs_opv_numops++; 12740435Speter /* 12841056Speter * Allocate and fill in the vectors 12940435Speter */ 13041056Speter for (i = 0; i < vnodeopv_num; i++) { 13141056Speter opv = vnodeopv_descs[i]; 13241056Speter opv_desc_vector_p = opv->opv_desc_vector_p; 13341056Speter if (*opv_desc_vector_p) 13441056Speter FREE(*opv_desc_vector_p, M_VNODE); 13540435Speter MALLOC(*opv_desc_vector_p, vop_t **, 13669781Sdwmalone vfs_opv_numops * sizeof(vop_t *), M_VNODE, 13769781Sdwmalone M_WAITOK | M_ZERO); 13841056Speter if (*opv_desc_vector_p == NULL) 13941056Speter panic("no memory for vop_t ** vector"); 14041056Speter 14165527Speter /* Fill in, with slot 0 being to return EOPNOTSUPP */ 14241056Speter opv_desc_vector = *opv_desc_vector_p; 14365527Speter opv_desc_vector[0] = (vop_t *)vop_eopnotsupp; 14441056Speter for (j = 0; opv->opv_desc_ops[j].opve_op; j++) { 14541056Speter opve_descp = &(opv->opv_desc_ops[j]); 14641056Speter opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 14741056Speter opve_descp->opve_impl; 14841056Speter } 14941056Speter 15041056Speter /* Replace unfilled routines with their default (slot 1). */ 15141056Speter opv_desc_vector = *(opv->opv_desc_vector_p); 15241056Speter if (opv_desc_vector[1] == NULL) 15341056Speter panic("vfs_opv_recalc: vector without a default."); 15441056Speter for (j = 0; j < vfs_opv_numops; j++) 15541056Speter if (opv_desc_vector[j] == NULL) 15641056Speter opv_desc_vector[j] = opv_desc_vector[1]; 15740435Speter } 15841056Speter} 15940435Speter 16091690Seivind/* Add a set of vnode operations (a description) to the table above. */ 16141056Spetervoid 16243311Sdillonvfs_add_vnodeops(const void *data) 16341056Speter{ 16443311Sdillon const struct vnodeopv_desc *opv; 16543311Sdillon const struct vnodeopv_desc **newopv; 16641056Speter struct vnodeop_desc **newop; 16741056Speter int *newref; 16841056Speter vop_t **opv_desc_vector; 16941056Speter struct vnodeop_desc *desc; 17041591Sarchie int i, j; 17141056Speter 17243311Sdillon opv = (const struct vnodeopv_desc *)data; 17343311Sdillon MALLOC(newopv, const struct vnodeopv_desc **, 17441056Speter (vnodeopv_num + 1) * sizeof(*newopv), M_VNODE, M_WAITOK); 17541056Speter if (newopv == NULL) 17641056Speter panic("vfs_add_vnodeops: no memory"); 17741056Speter if (vnodeopv_descs) { 17841056Speter bcopy(vnodeopv_descs, newopv, vnodeopv_num * sizeof(*newopv)); 17941056Speter FREE(vnodeopv_descs, M_VNODE); 18041056Speter } 18141056Speter newopv[vnodeopv_num] = opv; 18241056Speter vnodeopv_descs = newopv; 18341056Speter vnodeopv_num++; 18441056Speter 18541056Speter /* See if we have turned up a new vnode op desc */ 18641056Speter opv_desc_vector = *(opv->opv_desc_vector_p); 18741056Speter for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) { 18841056Speter for (j = 0; j < num_op_descs; j++) { 18941056Speter if (desc == vfs_op_descs[j]) { 19041056Speter /* found it, increase reference count */ 19141056Speter vfs_op_desc_refs[j]++; 19241056Speter break; 19341056Speter } 1941541Srgrimes } 19541056Speter if (j == num_op_descs) { 19641056Speter /* not found, new entry */ 19741056Speter MALLOC(newop, struct vnodeop_desc **, 19841056Speter (num_op_descs + 1) * sizeof(*newop), 19941056Speter M_VNODE, M_WAITOK); 20041056Speter if (newop == NULL) 20141056Speter panic("vfs_add_vnodeops: no memory for desc"); 20241056Speter /* new reference count (for unload) */ 20341056Speter MALLOC(newref, int *, 20441056Speter (num_op_descs + 1) * sizeof(*newref), 20541056Speter M_VNODE, M_WAITOK); 20641056Speter if (newref == NULL) 20741056Speter panic("vfs_add_vnodeops: no memory for refs"); 20841056Speter if (vfs_op_descs) { 20941056Speter bcopy(vfs_op_descs, newop, 21041056Speter num_op_descs * sizeof(*newop)); 21141056Speter FREE(vfs_op_descs, M_VNODE); 21241056Speter } 21341056Speter if (vfs_op_desc_refs) { 21441056Speter bcopy(vfs_op_desc_refs, newref, 21541056Speter num_op_descs * sizeof(*newref)); 21641056Speter FREE(vfs_op_desc_refs, M_VNODE); 21741056Speter } 21841056Speter newop[num_op_descs] = desc; 21941056Speter newref[num_op_descs] = 1; 22041056Speter vfs_op_descs = newop; 22141056Speter vfs_op_desc_refs = newref; 22241056Speter num_op_descs++; 22341056Speter } 2241541Srgrimes } 22541056Speter vfs_opv_recalc(); 2261541Srgrimes} 2271541Srgrimes 22891690Seivind/* Remove a vnode type from the vnode description table above. */ 22941056Spetervoid 23043311Sdillonvfs_rm_vnodeops(const void *data) 2311541Srgrimes{ 23243311Sdillon const struct vnodeopv_desc *opv; 23343311Sdillon const struct vnodeopv_desc **newopv; 23441056Speter struct vnodeop_desc **newop; 23541056Speter int *newref; 23641056Speter vop_t **opv_desc_vector; 23741056Speter struct vnodeop_desc *desc; 23841056Speter int i, j, k; 2391541Srgrimes 24043351Sdillon opv = (const struct vnodeopv_desc *)data; 24141056Speter /* Lower ref counts on descs in the table and release if zero */ 24241056Speter opv_desc_vector = *(opv->opv_desc_vector_p); 24341056Speter for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) { 24441056Speter for (j = 0; j < num_op_descs; j++) { 24541056Speter if (desc == vfs_op_descs[j]) { 24641056Speter /* found it, decrease reference count */ 24741056Speter vfs_op_desc_refs[j]--; 24841056Speter break; 24941056Speter } 25041056Speter } 25141056Speter for (j = 0; j < num_op_descs; j++) { 25241056Speter if (vfs_op_desc_refs[j] > 0) 25341056Speter continue; 25441056Speter if (vfs_op_desc_refs[j] < 0) 25541056Speter panic("vfs_remove_vnodeops: negative refcnt"); 25641056Speter MALLOC(newop, struct vnodeop_desc **, 25741056Speter (num_op_descs - 1) * sizeof(*newop), 25841056Speter M_VNODE, M_WAITOK); 25941056Speter if (newop == NULL) 26041056Speter panic("vfs_remove_vnodeops: no memory for desc"); 26141056Speter /* new reference count (for unload) */ 26241056Speter MALLOC(newref, int *, 26341056Speter (num_op_descs - 1) * sizeof(*newref), 26441056Speter M_VNODE, M_WAITOK); 26541056Speter if (newref == NULL) 26641056Speter panic("vfs_remove_vnodeops: no memory for refs"); 26741056Speter for (k = j; k < (num_op_descs - 1); k++) { 26841056Speter vfs_op_descs[k] = vfs_op_descs[k + 1]; 26941056Speter vfs_op_desc_refs[k] = vfs_op_desc_refs[k + 1]; 27041056Speter } 27141056Speter bcopy(vfs_op_descs, newop, 27241056Speter (num_op_descs - 1) * sizeof(*newop)); 27341056Speter bcopy(vfs_op_desc_refs, newref, 27441056Speter (num_op_descs - 1) * sizeof(*newref)); 27541056Speter FREE(vfs_op_descs, M_VNODE); 27641056Speter FREE(vfs_op_desc_refs, M_VNODE); 27741056Speter vfs_op_descs = newop; 27841056Speter vfs_op_desc_refs = newref; 27941056Speter num_op_descs--; 28041056Speter } 28141056Speter } 28241056Speter 28341056Speter for (i = 0; i < vnodeopv_num; i++) { 28441056Speter if (vnodeopv_descs[i] == opv) { 28541056Speter for (j = i; j < (vnodeopv_num - 1); j++) 28641056Speter vnodeopv_descs[j] = vnodeopv_descs[j + 1]; 28741056Speter break; 28841056Speter } 28941056Speter } 29041056Speter if (i == vnodeopv_num) 29141056Speter panic("vfs_remove_vnodeops: opv not found"); 29243311Sdillon MALLOC(newopv, const struct vnodeopv_desc **, 29341056Speter (vnodeopv_num - 1) * sizeof(*newopv), M_VNODE, M_WAITOK); 29441056Speter if (newopv == NULL) 29541056Speter panic("vfs_remove_vnodeops: no memory"); 29641056Speter bcopy(vnodeopv_descs, newopv, (vnodeopv_num - 1) * sizeof(*newopv)); 29741056Speter FREE(vnodeopv_descs, M_VNODE); 29841056Speter vnodeopv_descs = newopv; 29941056Speter vnodeopv_num--; 30041056Speter 30141056Speter vfs_opv_recalc(); 3021541Srgrimes} 3031541Srgrimes 3041541Srgrimes/* 3051541Srgrimes * Routines having to do with the management of the vnode table. 3061541Srgrimes */ 3071541Srgrimesstruct vattr va_null; 3081541Srgrimes 3091541Srgrimes/* 3101541Srgrimes * Initialize the vnode structures and initialize each file system type. 3111541Srgrimes */ 31210358Sjulian/* ARGSUSED*/ 31310358Sjulianstatic void 31441056Spetervfsinit(void *dummy) 3151541Srgrimes{ 3161541Srgrimes 3171541Srgrimes vattr_null(&va_null); 31840435Speter} 31941056SpeterSYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL) 32040435Speter 32191690Seivind/* Register a new file system type in the global table */ 32240435Speterint 32341056Spetervfs_register(struct vfsconf *vfc) 32440435Speter{ 32544549Sdfr struct sysctl_oid *oidp; 32640435Speter struct vfsconf *vfsp; 32740435Speter 32840435Speter vfsp = NULL; 32940435Speter if (vfsconf) 33040435Speter for (vfsp = vfsconf; vfsp->vfc_next; vfsp = vfsp->vfc_next) 33144549Sdfr if (strcmp(vfc->vfc_name, vfsp->vfc_name) == 0) 33240435Speter return EEXIST; 33340435Speter 33440435Speter vfc->vfc_typenum = maxvfsconf++; 33540435Speter if (vfsp) 33640435Speter vfsp->vfc_next = vfc; 33740435Speter else 33840435Speter vfsconf = vfc; 33940435Speter vfc->vfc_next = NULL; 34040435Speter 34140435Speter /* 34244549Sdfr * If this filesystem has a sysctl node under vfs 34344549Sdfr * (i.e. vfs.xxfs), then change the oid number of that node to 34444549Sdfr * match the filesystem's type number. This allows user code 34544549Sdfr * which uses the type number to read sysctl variables defined 34644549Sdfr * by the filesystem to continue working. Since the oids are 34744549Sdfr * in a sorted list, we need to make sure the order is 34844549Sdfr * preserved by re-registering the oid after modifying its 34944549Sdfr * number. 35044549Sdfr */ 35172012Sphk SLIST_FOREACH(oidp, &sysctl__vfs_children, oid_link) 35244549Sdfr if (strcmp(oidp->oid_name, vfc->vfc_name) == 0) { 35344549Sdfr sysctl_unregister_oid(oidp); 35444549Sdfr oidp->oid_number = vfc->vfc_typenum; 35544549Sdfr sysctl_register_oid(oidp); 35644549Sdfr } 35744549Sdfr 35844549Sdfr /* 35940435Speter * Call init function for this VFS... 36040435Speter */ 36140435Speter (*(vfc->vfc_vfsops->vfs_init))(vfc); 36240435Speter 36340435Speter return 0; 3641541Srgrimes} 3652946Swollman 36640435Speter 36791690Seivind/* Remove registration of a file system type */ 36840435Speterint 36941056Spetervfs_unregister(struct vfsconf *vfc) 37040435Speter{ 37140435Speter struct vfsconf *vfsp, *prev_vfsp; 37240435Speter int error, i, maxtypenum; 37340435Speter 37440435Speter i = vfc->vfc_typenum; 37540435Speter 37640435Speter prev_vfsp = NULL; 37740435Speter for (vfsp = vfsconf; vfsp; 37840435Speter prev_vfsp = vfsp, vfsp = vfsp->vfc_next) { 37940435Speter if (!strcmp(vfc->vfc_name, vfsp->vfc_name)) 38040435Speter break; 38140435Speter } 38240435Speter if (vfsp == NULL) 38340435Speter return EINVAL; 38440435Speter if (vfsp->vfc_refcount) 38540435Speter return EBUSY; 38640435Speter if (vfc->vfc_vfsops->vfs_uninit != NULL) { 38740435Speter error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp); 38840435Speter if (error) 38940435Speter return (error); 39040435Speter } 39140435Speter if (prev_vfsp) 39240435Speter prev_vfsp->vfc_next = vfsp->vfc_next; 39340435Speter else 39440435Speter vfsconf = vfsp->vfc_next; 39540435Speter maxtypenum = VFS_GENERIC; 39640435Speter for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 39740435Speter if (maxtypenum < vfsp->vfc_typenum) 39840435Speter maxtypenum = vfsp->vfc_typenum; 39940435Speter maxvfsconf = maxtypenum + 1; 40040435Speter return 0; 40140435Speter} 40241056Speter 40391690Seivind/* 40491690Seivind * Standard kernel module handling code for file system modules. 40591690Seivind * Referenced from VFS_SET(). 40691690Seivind */ 40741056Speterint 40841170Sbdevfs_modevent(module_t mod, int type, void *data) 40941056Speter{ 41041056Speter struct vfsconf *vfc; 41141056Speter int error = 0; 41241056Speter 41341056Speter vfc = (struct vfsconf *)data; 41441056Speter 41541056Speter switch (type) { 41641056Speter case MOD_LOAD: 41741056Speter if (vfc) 41841056Speter error = vfs_register(vfc); 41941056Speter break; 42041056Speter 42141056Speter case MOD_UNLOAD: 42241056Speter if (vfc) 42341056Speter error = vfs_unregister(vfc); 42441056Speter break; 42541056Speter default: /* including MOD_SHUTDOWN */ 42641056Speter break; 42741056Speter } 42841056Speter return (error); 42941056Speter} 430