1 /* $NetBSD: vfs_init.c,v 1.4 1995/03/19 23:45:01 mycroft 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 55 /* 56 * Sigh, such primitive tools are these... 57 */ 58 #if 0 59 #define DODEBUG(A) A 60 #else 61 #define DODEBUG(A) 62 #endif 63 64 extern struct vnodeopv_desc *vfs_opv_descs[]; 65 /* a list of lists of vnodeops defns */ 66 extern struct vnodeop_desc *vfs_op_descs[]; 67 /* and the operations they perform */ 68 /* 69 * This code doesn't work if the defn is **vnodop_defns with cc. 70 * The problem is because of the compiler sometimes putting in an 71 * extra level of indirection for arrays. It's an interesting 72 * "feature" of C. 73 */ 74 int vfs_opv_numops; 75 76 typedef (*PFI)(); /* the standard Pointer to a Function returning an Int */ 77 78 /* 79 * A miscellaneous routine. 80 * A generic "default" routine that just returns an error. 81 */ 82 int 83 vn_default_error() 84 { 85 86 return (EOPNOTSUPP); 87 } 88 89 /* 90 * vfs_init.c 91 * 92 * Allocate and fill in operations vectors. 93 * 94 * An undocumented feature of this approach to defining operations is that 95 * there can be multiple entries in vfs_opv_descs for the same operations 96 * vector. This allows third parties to extend the set of operations 97 * supported by another layer in a binary compatibile way. For example, 98 * assume that NFS needed to be modified to support Ficus. NFS has an entry 99 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 100 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 101 * listing those new operations Ficus adds to NFS, all without modifying the 102 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 103 * that is a(whole)nother story.) This is a feature. 104 */ 105 106 /* 107 * Allocate and init the vector, if it needs it. 108 * Also handle backwards compatibility. 109 */ 110 void 111 vfs_opv_init_explicit(vfs_opv_desc) 112 struct vnodeopv_desc *vfs_opv_desc; 113 { 114 int (**opv_desc_vector)(); 115 struct vnodeopv_entry_desc *opve_descp; 116 117 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 118 119 if (opv_desc_vector == NULL) { 120 /* XXX - shouldn't be M_VNODE */ 121 MALLOC(opv_desc_vector, PFI *, 122 vfs_opv_numops * sizeof(PFI), M_VNODE, M_WAITOK); 123 bzero(opv_desc_vector, vfs_opv_numops * sizeof(PFI)); 124 *(vfs_opv_desc->opv_desc_vector_p) = opv_desc_vector; 125 DODEBUG(printf("vector at %p allocated\n", 126 opv_desc_vector_p)); 127 } 128 129 for (opve_descp = vfs_opv_desc->opv_desc_ops; 130 opve_descp->opve_op; 131 opve_descp++) { 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 != VOFFSET(vop_default)) { 151 printf("operation %s not listed in %s.\n", 152 opve_descp->opve_op->vdesc_name, "vfs_op_descs"); 153 panic ("vfs_opv_init: bad operation"); 154 } 155 156 /* 157 * Fill in this entry. 158 */ 159 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 160 opve_descp->opve_impl; 161 } 162 } 163 164 void 165 vfs_opv_init_default(vfs_opv_desc) 166 struct vnodeopv_desc *vfs_opv_desc; 167 { 168 int j; 169 int (**opv_desc_vector)(); 170 struct vnodeopv_entry_desc *opve_descp; 171 172 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 173 174 /* 175 * Force every operations vector to have a default routine. 176 */ 177 if (opv_desc_vector[VOFFSET(vop_default)] == NULL) 178 panic("vfs_opv_init: operation vector without default routine."); 179 180 for (j = 0; j < vfs_opv_numops; j++) 181 if (opv_desc_vector[j] == NULL) 182 opv_desc_vector[j] = 183 opv_desc_vector[VOFFSET(vop_default)]; 184 } 185 186 void 187 vfs_opv_init() 188 { 189 int i; 190 191 /* 192 * Allocate the dynamic vectors and fill them in. 193 */ 194 for (i = 0; vfs_opv_descs[i]; i++) 195 vfs_opv_init_explicit(vfs_opv_descs[i]); 196 197 /* 198 * Finally, go back and replace unfilled routines 199 * with their default. 200 */ 201 for (i = 0; vfs_opv_descs[i]; i++) 202 vfs_opv_init_default(vfs_opv_descs[i]); 203 } 204 205 /* 206 * Initialize known vnode operations vectors. 207 */ 208 void 209 vfs_op_init() 210 { 211 int i; 212 213 DODEBUG(printf("Vnode_interface_init.\n")); 214 /* 215 * Set all vnode vectors to a well known value. 216 */ 217 for (i = 0; vfs_opv_descs[i]; i++) 218 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 219 /* 220 * Figure out how many ops there are by counting the table, 221 * and assign each its offset. 222 */ 223 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 224 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 225 vfs_opv_numops++; 226 } 227 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 228 } 229 230 /* 231 * Routines having to do with the management of the vnode table. 232 */ 233 extern struct vnodeops dead_vnodeops; 234 extern struct vnodeops spec_vnodeops; 235 extern void vclean(); 236 struct vattr va_null; 237 238 /* 239 * Initialize the vnode structures and initialize each file system type. 240 */ 241 vfsinit() 242 { 243 struct vfsops **vfsp; 244 245 /* 246 * Initialize the vnode table 247 */ 248 vntblinit(); 249 /* 250 * Initialize the vnode name cache 251 */ 252 nchinit(); 253 /* 254 * Build vnode operation vectors. 255 */ 256 vfs_op_init(); 257 vfs_opv_init(); /* finish the job */ 258 /* 259 * Initialize each file system type. 260 */ 261 vattr_null(&va_null); 262 for (vfsp = &vfssw[0]; vfsp < &vfssw[nvfssw]; vfsp++) { 263 if (*vfsp == NULL) 264 continue; 265 (*(*vfsp)->vfs_init)(); 266 } 267 } 268