1 /* $NetBSD: vfs_init.c,v 1.6 1996/02/09 19:00:58 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed 8 * to Berkeley by John Heidemann of the UCLA Ficus project. 9 * 10 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 41 */ 42 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 #include <sys/time.h> 47 #include <sys/vnode.h> 48 #include <sys/stat.h> 49 #include <sys/namei.h> 50 #include <sys/ucred.h> 51 #include <sys/buf.h> 52 #include <sys/errno.h> 53 #include <sys/malloc.h> 54 #include <sys/systm.h> 55 56 /* 57 * Sigh, such primitive tools are these... 58 */ 59 #if 0 60 #define DODEBUG(A) A 61 #else 62 #define DODEBUG(A) 63 #endif 64 65 extern struct vnodeopv_desc *vfs_opv_descs[]; 66 /* a list of lists of vnodeops defns */ 67 extern struct vnodeop_desc *vfs_op_descs[]; 68 /* and the operations they perform */ 69 /* 70 * This code doesn't work if the defn is **vnodop_defns with cc. 71 * The problem is because of the compiler sometimes putting in an 72 * extra level of indirection for arrays. It's an interesting 73 * "feature" of C. 74 */ 75 int vfs_opv_numops; 76 77 typedef (*PFI) __P((void *)); 78 79 /* 80 * A miscellaneous routine. 81 * A generic "default" routine that just returns an error. 82 */ 83 /*ARGSUSED*/ 84 int 85 vn_default_error(v) 86 void *v; 87 { 88 89 return (EOPNOTSUPP); 90 } 91 92 /* 93 * vfs_init.c 94 * 95 * Allocate and fill in operations vectors. 96 * 97 * An undocumented feature of this approach to defining operations is that 98 * there can be multiple entries in vfs_opv_descs for the same operations 99 * vector. This allows third parties to extend the set of operations 100 * supported by another layer in a binary compatibile way. For example, 101 * assume that NFS needed to be modified to support Ficus. NFS has an entry 102 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 103 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 104 * listing those new operations Ficus adds to NFS, all without modifying the 105 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 106 * that is a(whole)nother story.) This is a feature. 107 */ 108 109 /* 110 * Allocate and init the vector, if it needs it. 111 * Also handle backwards compatibility. 112 */ 113 void 114 vfs_opv_init_explicit(vfs_opv_desc) 115 struct vnodeopv_desc *vfs_opv_desc; 116 { 117 int (**opv_desc_vector) __P((void *)); 118 struct vnodeopv_entry_desc *opve_descp; 119 120 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 121 122 if (opv_desc_vector == NULL) { 123 /* XXX - shouldn't be M_VNODE */ 124 MALLOC(opv_desc_vector, PFI *, 125 vfs_opv_numops * sizeof(PFI), M_VNODE, M_WAITOK); 126 bzero(opv_desc_vector, vfs_opv_numops * sizeof(PFI)); 127 *(vfs_opv_desc->opv_desc_vector_p) = opv_desc_vector; 128 DODEBUG(printf("vector at %p allocated\n", 129 opv_desc_vector_p)); 130 } 131 132 for (opve_descp = vfs_opv_desc->opv_desc_ops; 133 opve_descp->opve_op; 134 opve_descp++) { 135 /* 136 * Sanity check: is this operation listed 137 * in the list of operations? We check this 138 * by seeing if its offest is zero. Since 139 * the default routine should always be listed 140 * first, it should be the only one with a zero 141 * offset. Any other operation with a zero 142 * offset is probably not listed in 143 * vfs_op_descs, and so is probably an error. 144 * 145 * A panic here means the layer programmer 146 * has committed the all-too common bug 147 * of adding a new operation to the layer's 148 * list of vnode operations but 149 * not adding the operation to the system-wide 150 * list of supported operations. 151 */ 152 if (opve_descp->opve_op->vdesc_offset == 0 && 153 opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) { 154 printf("operation %s not listed in %s.\n", 155 opve_descp->opve_op->vdesc_name, "vfs_op_descs"); 156 panic ("vfs_opv_init: bad operation"); 157 } 158 159 /* 160 * Fill in this entry. 161 */ 162 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 163 opve_descp->opve_impl; 164 } 165 } 166 167 void 168 vfs_opv_init_default(vfs_opv_desc) 169 struct vnodeopv_desc *vfs_opv_desc; 170 { 171 int j; 172 int (**opv_desc_vector) __P((void *)); 173 174 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 175 176 /* 177 * Force every operations vector to have a default routine. 178 */ 179 if (opv_desc_vector[VOFFSET(vop_default)] == NULL) 180 panic("vfs_opv_init: operation vector without default routine."); 181 182 for (j = 0; j < vfs_opv_numops; j++) 183 if (opv_desc_vector[j] == NULL) 184 opv_desc_vector[j] = 185 opv_desc_vector[VOFFSET(vop_default)]; 186 } 187 188 void 189 vfs_opv_init() 190 { 191 int i; 192 193 /* 194 * Allocate the dynamic vectors and fill them in. 195 */ 196 for (i = 0; vfs_opv_descs[i]; i++) 197 vfs_opv_init_explicit(vfs_opv_descs[i]); 198 199 /* 200 * Finally, go back and replace unfilled routines 201 * with their default. 202 */ 203 for (i = 0; vfs_opv_descs[i]; i++) 204 vfs_opv_init_default(vfs_opv_descs[i]); 205 } 206 207 /* 208 * Initialize known vnode operations vectors. 209 */ 210 void 211 vfs_op_init() 212 { 213 int i; 214 215 DODEBUG(printf("Vnode_interface_init.\n")); 216 /* 217 * Set all vnode vectors to a well known value. 218 */ 219 for (i = 0; vfs_opv_descs[i]; i++) 220 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 221 /* 222 * Figure out how many ops there are by counting the table, 223 * and assign each its offset. 224 */ 225 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 226 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 227 vfs_opv_numops++; 228 } 229 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 230 } 231 232 /* 233 * Routines having to do with the management of the vnode table. 234 */ 235 extern struct vnodeops dead_vnodeops; 236 extern struct vnodeops spec_vnodeops; 237 struct vattr va_null; 238 239 /* 240 * Initialize the vnode structures and initialize each file system type. 241 */ 242 void 243 vfsinit() 244 { 245 struct vfsops **vfsp; 246 247 /* 248 * Initialize the vnode table 249 */ 250 vntblinit(); 251 /* 252 * Initialize the vnode name cache 253 */ 254 nchinit(); 255 /* 256 * Build vnode operation vectors. 257 */ 258 vfs_op_init(); 259 vfs_opv_init(); /* finish the job */ 260 /* 261 * Initialize each file system type. 262 */ 263 vattr_null(&va_null); 264 for (vfsp = &vfssw[0]; vfsp < &vfssw[nvfssw]; vfsp++) { 265 if (*vfsp == NULL) 266 continue; 267 (*(*vfsp)->vfs_init)(); 268 } 269 } 270