vfs_init.c revision 1541
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 */ 40 41 42#include <sys/param.h> 43#include <sys/mount.h> 44#include <sys/time.h> 45#include <sys/vnode.h> 46#include <sys/stat.h> 47#include <sys/namei.h> 48#include <sys/ucred.h> 49#include <sys/buf.h> 50#include <sys/errno.h> 51#include <sys/malloc.h> 52 53/* 54 * Sigh, such primitive tools are these... 55 */ 56#if 0 57#define DODEBUG(A) A 58#else 59#define DODEBUG(A) 60#endif 61 62extern struct vnodeopv_desc *vfs_opv_descs[]; 63 /* a list of lists of vnodeops defns */ 64extern struct vnodeop_desc *vfs_op_descs[]; 65 /* and the operations they perform */ 66/* 67 * This code doesn't work if the defn is **vnodop_defns with cc. 68 * The problem is because of the compiler sometimes putting in an 69 * extra level of indirection for arrays. It's an interesting 70 * "feature" of C. 71 */ 72int vfs_opv_numops; 73 74typedef (*PFI)(); /* the standard Pointer to a Function returning an Int */ 75 76/* 77 * A miscellaneous routine. 78 * A generic "default" routine that just returns an error. 79 */ 80int 81vn_default_error() 82{ 83 84 return (EOPNOTSUPP); 85} 86 87/* 88 * vfs_init.c 89 * 90 * Allocate and fill in operations vectors. 91 * 92 * An undocumented feature of this approach to defining operations is that 93 * there can be multiple entries in vfs_opv_descs for the same operations 94 * vector. This allows third parties to extend the set of operations 95 * supported by another layer in a binary compatibile way. For example, 96 * assume that NFS needed to be modified to support Ficus. NFS has an entry 97 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 98 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 99 * listing those new operations Ficus adds to NFS, all without modifying the 100 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 101 * that is a(whole)nother story.) This is a feature. 102 */ 103void 104vfs_opv_init() 105{ 106 int i, j, k; 107 int (***opv_desc_vector_p)(); 108 int (**opv_desc_vector)(); 109 struct vnodeopv_entry_desc *opve_descp; 110 111 /* 112 * Allocate the dynamic vectors and fill them in. 113 */ 114 for (i=0; vfs_opv_descs[i]; i++) { 115 opv_desc_vector_p = vfs_opv_descs[i]->opv_desc_vector_p; 116 /* 117 * Allocate and init the vector, if it needs it. 118 * Also handle backwards compatibility. 119 */ 120 if (*opv_desc_vector_p == NULL) { 121 /* XXX - shouldn't be M_VNODE */ 122 MALLOC(*opv_desc_vector_p, PFI*, 123 vfs_opv_numops*sizeof(PFI), M_VNODE, M_WAITOK); 124 bzero (*opv_desc_vector_p, vfs_opv_numops*sizeof(PFI)); 125 DODEBUG(printf("vector at %x allocated\n", 126 opv_desc_vector_p)); 127 } 128 opv_desc_vector = *opv_desc_vector_p; 129 for (j=0; vfs_opv_descs[i]->opv_desc_ops[j].opve_op; j++) { 130 opve_descp = &(vfs_opv_descs[i]->opv_desc_ops[j]); 131 132 /* 133 * Sanity check: is this operation listed 134 * in the list of operations? We check this 135 * by seeing if its offest is zero. Since 136 * the default routine should always be listed 137 * first, it should be the only one with a zero 138 * offset. Any other operation with a zero 139 * offset is probably not listed in 140 * vfs_op_descs, and so is probably an error. 141 * 142 * A panic here means the layer programmer 143 * has committed the all-too common bug 144 * of adding a new operation to the layer's 145 * list of vnode operations but 146 * not adding the operation to the system-wide 147 * list of supported operations. 148 */ 149 if (opve_descp->opve_op->vdesc_offset == 0 && 150 opve_descp->opve_op->vdesc_offset != 151 VOFFSET(vop_default)) { 152 printf("operation %s not listed in %s.\n", 153 opve_descp->opve_op->vdesc_name, 154 "vfs_op_descs"); 155 panic ("vfs_opv_init: bad operation"); 156 } 157 /* 158 * Fill in this entry. 159 */ 160 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 161 opve_descp->opve_impl; 162 } 163 } 164 /* 165 * Finally, go back and replace unfilled routines 166 * with their default. (Sigh, an O(n^3) algorithm. I 167 * could make it better, but that'd be work, and n is small.) 168 */ 169 for (i = 0; vfs_opv_descs[i]; i++) { 170 opv_desc_vector = *(vfs_opv_descs[i]->opv_desc_vector_p); 171 /* 172 * Force every operations vector to have a default routine. 173 */ 174 if (opv_desc_vector[VOFFSET(vop_default)]==NULL) { 175 panic("vfs_opv_init: operation vector without default routine."); 176 } 177 for (k = 0; k<vfs_opv_numops; k++) 178 if (opv_desc_vector[k] == NULL) 179 opv_desc_vector[k] = 180 opv_desc_vector[VOFFSET(vop_default)]; 181 } 182} 183 184/* 185 * Initialize known vnode operations vectors. 186 */ 187void 188vfs_op_init() 189{ 190 int i; 191 192 DODEBUG(printf("Vnode_interface_init.\n")); 193 /* 194 * Set all vnode vectors to a well known value. 195 */ 196 for (i = 0; vfs_opv_descs[i]; i++) 197 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 198 /* 199 * Figure out how many ops there are by counting the table, 200 * and assign each its offset. 201 */ 202 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 203 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 204 vfs_opv_numops++; 205 } 206 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 207} 208 209/* 210 * Routines having to do with the management of the vnode table. 211 */ 212extern struct vnodeops dead_vnodeops; 213extern struct vnodeops spec_vnodeops; 214extern void vclean(); 215struct vattr va_null; 216 217/* 218 * Initialize the vnode structures and initialize each file system type. 219 */ 220vfsinit() 221{ 222 struct vfsops **vfsp; 223 224 /* 225 * Initialize the vnode table 226 */ 227 vntblinit(); 228 /* 229 * Initialize the vnode name cache 230 */ 231 nchinit(); 232 /* 233 * Build vnode operation vectors. 234 */ 235 vfs_op_init(); 236 vfs_opv_init(); /* finish the job */ 237 /* 238 * Initialize each file system type. 239 */ 240 vattr_null(&va_null); 241 for (vfsp = &vfssw[0]; vfsp <= &vfssw[MOUNT_MAXTYPE]; vfsp++) { 242 if (*vfsp == NULL) 243 continue; 244 (*(*vfsp)->vfs_init)(); 245 } 246} 247