vfs_init.c revision 1817
1/* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed 6 * to Berkeley by John Heidemann of the UCLA Ficus project. 7 * 8 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 39 * $Id$ 40 */ 41 42 43#include <sys/param.h> 44#include <sys/mount.h> 45#include <sys/time.h> 46#include <sys/vnode.h> 47#include <sys/stat.h> 48#include <sys/namei.h> 49#include <sys/ucred.h> 50#include <sys/buf.h> 51#include <sys/errno.h> 52#include <sys/malloc.h> 53 54/* 55 * Sigh, such primitive tools are these... 56 */ 57#if 0 58#define DODEBUG(A) A 59#else 60#define DODEBUG(A) 61#endif 62 63extern struct vnodeopv_desc *vfs_opv_descs[]; 64 /* a list of lists of vnodeops defns */ 65extern struct vnodeop_desc *vfs_op_descs[]; 66 /* and the operations they perform */ 67/* 68 * This code doesn't work if the defn is **vnodop_defns with cc. 69 * The problem is because of the compiler sometimes putting in an 70 * extra level of indirection for arrays. It's an interesting 71 * "feature" of C. 72 */ 73int vfs_opv_numops; 74 75typedef (*PFI)(); /* the standard Pointer to a Function returning an Int */ 76 77/* 78 * A miscellaneous routine. 79 * A generic "default" routine that just returns an error. 80 */ 81int 82vn_default_error() 83{ 84 85 return (EOPNOTSUPP); 86} 87 88/* 89 * vfs_init.c 90 * 91 * Allocate and fill in operations vectors. 92 * 93 * An undocumented feature of this approach to defining operations is that 94 * there can be multiple entries in vfs_opv_descs for the same operations 95 * vector. This allows third parties to extend the set of operations 96 * supported by another layer in a binary compatibile way. For example, 97 * assume that NFS needed to be modified to support Ficus. NFS has an entry 98 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 99 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 100 * listing those new operations Ficus adds to NFS, all without modifying the 101 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 102 * that is a(whole)nother story.) This is a feature. 103 */ 104void 105vfs_opv_init() 106{ 107 int i, j, k; 108 int (***opv_desc_vector_p)(); 109 int (**opv_desc_vector)(); 110 struct vnodeopv_entry_desc *opve_descp; 111 112 /* 113 * Allocate the dynamic vectors and fill them in. 114 */ 115 for (i=0; vfs_opv_descs[i]; i++) { 116 opv_desc_vector_p = vfs_opv_descs[i]->opv_desc_vector_p; 117 /* 118 * Allocate and init the vector, if it needs it. 119 * Also handle backwards compatibility. 120 */ 121 if (*opv_desc_vector_p == NULL) { 122 /* XXX - shouldn't be M_VNODE */ 123 MALLOC(*opv_desc_vector_p, PFI*, 124 vfs_opv_numops*sizeof(PFI), M_VNODE, M_WAITOK); 125 bzero (*opv_desc_vector_p, vfs_opv_numops*sizeof(PFI)); 126 DODEBUG(printf("vector at %x allocated\n", 127 opv_desc_vector_p)); 128 } 129 opv_desc_vector = *opv_desc_vector_p; 130 for (j=0; vfs_opv_descs[i]->opv_desc_ops[j].opve_op; j++) { 131 opve_descp = &(vfs_opv_descs[i]->opv_desc_ops[j]); 132 133 /* 134 * Sanity check: is this operation listed 135 * in the list of operations? We check this 136 * by seeing if its offest is zero. Since 137 * the default routine should always be listed 138 * first, it should be the only one with a zero 139 * offset. Any other operation with a zero 140 * offset is probably not listed in 141 * vfs_op_descs, and so is probably an error. 142 * 143 * A panic here means the layer programmer 144 * has committed the all-too common bug 145 * of adding a new operation to the layer's 146 * list of vnode operations but 147 * not adding the operation to the system-wide 148 * list of supported operations. 149 */ 150 if (opve_descp->opve_op->vdesc_offset == 0 && 151 opve_descp->opve_op->vdesc_offset != 152 VOFFSET(vop_default)) { 153 printf("operation %s not listed in %s.\n", 154 opve_descp->opve_op->vdesc_name, 155 "vfs_op_descs"); 156 panic ("vfs_opv_init: bad operation"); 157 } 158 /* 159 * Fill in this entry. 160 */ 161 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 162 opve_descp->opve_impl; 163 } 164 } 165 /* 166 * Finally, go back and replace unfilled routines 167 * with their default. (Sigh, an O(n^3) algorithm. I 168 * could make it better, but that'd be work, and n is small.) 169 */ 170 for (i = 0; vfs_opv_descs[i]; i++) { 171 opv_desc_vector = *(vfs_opv_descs[i]->opv_desc_vector_p); 172 /* 173 * Force every operations vector to have a default routine. 174 */ 175 if (opv_desc_vector[VOFFSET(vop_default)]==NULL) { 176 panic("vfs_opv_init: operation vector without default routine."); 177 } 178 for (k = 0; k<vfs_opv_numops; k++) 179 if (opv_desc_vector[k] == NULL) 180 opv_desc_vector[k] = 181 opv_desc_vector[VOFFSET(vop_default)]; 182 } 183} 184 185/* 186 * Initialize known vnode operations vectors. 187 */ 188void 189vfs_op_init() 190{ 191 int i; 192 193 DODEBUG(printf("Vnode_interface_init.\n")); 194 /* 195 * Set all vnode vectors to a well known value. 196 */ 197 for (i = 0; vfs_opv_descs[i]; i++) 198 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 199 /* 200 * Figure out how many ops there are by counting the table, 201 * and assign each its offset. 202 */ 203 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 204 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 205 vfs_opv_numops++; 206 } 207 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 208} 209 210/* 211 * Routines having to do with the management of the vnode table. 212 */ 213extern struct vnodeops dead_vnodeops; 214extern struct vnodeops spec_vnodeops; 215extern void vclean(); 216struct vattr va_null; 217 218/* 219 * Initialize the vnode structures and initialize each file system type. 220 */ 221void 222vfsinit() 223{ 224 struct vfsops **vfsp; 225 226 /* 227 * Initialize the vnode table 228 */ 229 vntblinit(); 230 /* 231 * Initialize the vnode name cache 232 */ 233 nchinit(); 234 /* 235 * Build vnode operation vectors. 236 */ 237 vfs_op_init(); 238 vfs_opv_init(); /* finish the job */ 239 /* 240 * Initialize each file system type. 241 */ 242 vattr_null(&va_null); 243 for (vfsp = &vfssw[0]; vfsp <= &vfssw[MOUNT_MAXTYPE]; vfsp++) { 244 if (*vfsp == NULL) 245 continue; 246 (*(*vfsp)->vfs_init)(); 247 } 248} 249