1 /* $OpenBSD: vfs_init.c,v 1.12 2002/03/14 01:27:06 millert Exp $ */ 2 /* $NetBSD: vfs_init.c,v 1.6 1996/02/09 19:00:58 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed 9 * to Berkeley by John Heidemann of the UCLA Ficus project. 10 * 11 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 42 */ 43 44 45 #include <sys/param.h> 46 #include <sys/mount.h> 47 #include <sys/time.h> 48 #include <sys/vnode.h> 49 #include <sys/stat.h> 50 #include <sys/namei.h> 51 #include <sys/ucred.h> 52 #include <sys/buf.h> 53 #include <sys/errno.h> 54 #include <sys/malloc.h> 55 #include <sys/systm.h> 56 57 /* 58 * Sigh, such primitive tools are these... 59 */ 60 #if 0 61 #define DODEBUG(A) A 62 #else 63 #define DODEBUG(A) 64 #endif 65 66 extern struct vnodeopv_desc *vfs_opv_descs[]; 67 /* a list of lists of vnodeops defns */ 68 extern struct vnodeop_desc *vfs_op_descs[]; 69 /* and the operations they perform */ 70 /* 71 * This code doesn't work if the defn is **vnodop_defns with cc. 72 * The problem is because of the compiler sometimes putting in an 73 * extra level of indirection for arrays. It's an interesting 74 * "feature" of C. 75 */ 76 int vfs_opv_numops; 77 78 typedef int (*PFI)(void *); 79 80 /* 81 * A miscellaneous routine. 82 * A generic "default" routine that just returns an error. 83 */ 84 /*ARGSUSED*/ 85 int 86 vn_default_error(v) 87 void *v; 88 { 89 90 return (EOPNOTSUPP); 91 } 92 93 /* 94 * vfs_init.c 95 * 96 * Allocate and fill in operations vectors. 97 * 98 * An undocumented feature of this approach to defining operations is that 99 * there can be multiple entries in vfs_opv_descs for the same operations 100 * vector. This allows third parties to extend the set of operations 101 * supported by another layer in a binary compatibile way. For example, 102 * assume that NFS needed to be modified to support Ficus. NFS has an entry 103 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 104 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 105 * listing those new operations Ficus adds to NFS, all without modifying the 106 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 107 * that is a(whole)nother story.) This is a feature. 108 */ 109 110 /* 111 * Allocate and init the vector, if it needs it. 112 * Also handle backwards compatibility. 113 */ 114 void 115 vfs_opv_init_explicit(vfs_opv_desc) 116 struct vnodeopv_desc *vfs_opv_desc; 117 { 118 int (**opv_desc_vector)(void *); 119 struct vnodeopv_entry_desc *opve_descp; 120 121 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 122 123 if (opv_desc_vector == NULL) { 124 /* XXX - shouldn't be M_VNODE */ 125 opv_desc_vector = malloc(vfs_opv_numops * sizeof(PFI), 126 M_VNODE, M_WAITOK); 127 bzero(opv_desc_vector, vfs_opv_numops * sizeof(PFI)); 128 *(vfs_opv_desc->opv_desc_vector_p) = opv_desc_vector; 129 DODEBUG(printf("vector at %p allocated\n", 130 opv_desc_vector_p)); 131 } 132 133 for (opve_descp = vfs_opv_desc->opv_desc_ops; 134 opve_descp->opve_op; 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)(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 int i; 246 struct vfsconf *vfsconflist; 247 int vfsconflistlen; 248 249 /* 250 * Initialize the vnode table 251 */ 252 vntblinit(); 253 /* 254 * Initialize the vnode name cache 255 */ 256 nchinit(); 257 /* 258 * Build vnode operation vectors. 259 */ 260 vfs_op_init(); 261 vfs_opv_init(); /* finish the job */ 262 /* 263 * Initialize each file system type. 264 */ 265 vattr_null(&va_null); 266 267 /* 268 * Stop using vfsconf and maxvfsconf as a temporary storage, 269 * set them to their correct values now. 270 */ 271 vfsconflist = vfsconf; 272 vfsconflistlen = maxvfsconf; 273 vfsconf = NULL; 274 maxvfsconf = 0; 275 276 for (i = 0; i < vfsconflistlen; i++) 277 vfs_register(&vfsconflist[i]); 278 } 279