1 /* $OpenBSD: vfs_init.c,v 1.9 1999/02/19 18:02:48 art 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) __P((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) __P((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 MALLOC(opv_desc_vector, PFI *, 126 vfs_opv_numops * sizeof(PFI), 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; 135 opve_descp++) { 136 /* 137 * Sanity check: is this operation listed 138 * in the list of operations? We check this 139 * by seeing if its offest is zero. Since 140 * the default routine should always be listed 141 * first, it should be the only one with a zero 142 * offset. Any other operation with a zero 143 * offset is probably not listed in 144 * vfs_op_descs, and so is probably an error. 145 * 146 * A panic here means the layer programmer 147 * has committed the all-too common bug 148 * of adding a new operation to the layer's 149 * list of vnode operations but 150 * not adding the operation to the system-wide 151 * list of supported operations. 152 */ 153 if (opve_descp->opve_op->vdesc_offset == 0 && 154 opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) { 155 printf("operation %s not listed in %s.\n", 156 opve_descp->opve_op->vdesc_name, "vfs_op_descs"); 157 panic ("vfs_opv_init: bad operation"); 158 } 159 160 /* 161 * Fill in this entry. 162 */ 163 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 164 opve_descp->opve_impl; 165 } 166 } 167 168 void 169 vfs_opv_init_default(vfs_opv_desc) 170 struct vnodeopv_desc *vfs_opv_desc; 171 { 172 int j; 173 int (**opv_desc_vector) __P((void *)); 174 175 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 176 177 /* 178 * Force every operations vector to have a default routine. 179 */ 180 if (opv_desc_vector[VOFFSET(vop_default)] == NULL) 181 panic("vfs_opv_init: operation vector without default routine."); 182 183 for (j = 0; j < vfs_opv_numops; j++) 184 if (opv_desc_vector[j] == NULL) 185 opv_desc_vector[j] = 186 opv_desc_vector[VOFFSET(vop_default)]; 187 } 188 189 void 190 vfs_opv_init() 191 { 192 int i; 193 194 /* 195 * Allocate the dynamic vectors and fill them in. 196 */ 197 for (i = 0; vfs_opv_descs[i]; i++) 198 vfs_opv_init_explicit(vfs_opv_descs[i]); 199 200 /* 201 * Finally, go back and replace unfilled routines 202 * with their default. 203 */ 204 for (i = 0; vfs_opv_descs[i]; i++) 205 vfs_opv_init_default(vfs_opv_descs[i]); 206 } 207 208 /* 209 * Initialize known vnode operations vectors. 210 */ 211 void 212 vfs_op_init() 213 { 214 int i; 215 216 DODEBUG(printf("Vnode_interface_init.\n")); 217 /* 218 * Set all vnode vectors to a well known value. 219 */ 220 for (i = 0; vfs_opv_descs[i]; i++) 221 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 222 /* 223 * Figure out how many ops there are by counting the table, 224 * and assign each its offset. 225 */ 226 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 227 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 228 vfs_opv_numops++; 229 } 230 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 231 } 232 233 /* 234 * Routines having to do with the management of the vnode table. 235 */ 236 extern struct vnodeops dead_vnodeops; 237 extern struct vnodeops spec_vnodeops; 238 struct vattr va_null; 239 240 /* 241 * Initialize the vnode structures and initialize each file system type. 242 */ 243 void 244 vfsinit() 245 { 246 int i; 247 struct vfsconf *vfsconflist; 248 int vfsconflistlen; 249 250 /* 251 * Initialize the vnode table 252 */ 253 vntblinit(); 254 /* 255 * Initialize the vnode name cache 256 */ 257 nchinit(); 258 /* 259 * Build vnode operation vectors. 260 */ 261 vfs_op_init(); 262 vfs_opv_init(); /* finish the job */ 263 /* 264 * Initialize each file system type. 265 */ 266 vattr_null(&va_null); 267 268 /* 269 * Stop using vfsconf and maxvfsconf as a temporary storage, 270 * set them to their correct values now. 271 */ 272 vfsconflist = vfsconf; 273 vfsconflistlen = maxvfsconf; 274 vfsconf = NULL; 275 maxvfsconf = 0; 276 277 for (i = 0; i < vfsconflistlen; i++) 278 vfs_register(&vfsconflist[i]); 279 } 280