1 /* $OpenBSD: vfs_init.c,v 1.15 2003/07/24 22:00:24 mickey 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. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 38 */ 39 40 41 #include <sys/param.h> 42 #include <sys/mount.h> 43 #include <sys/time.h> 44 #include <sys/vnode.h> 45 #include <sys/stat.h> 46 #include <sys/namei.h> 47 #include <sys/ucred.h> 48 #include <sys/buf.h> 49 #include <sys/errno.h> 50 #include <sys/malloc.h> 51 #include <sys/systm.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 62 extern struct vnodeopv_desc *vfs_opv_descs[]; 63 /* a list of lists of vnodeops defns */ 64 extern 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 */ 72 int vfs_opv_numops; 73 74 typedef int (*PFI)(void *); 75 76 /* 77 * A miscellaneous routine. 78 * A generic "default" routine that just returns an error. 79 */ 80 /*ARGSUSED*/ 81 int 82 vn_default_error(v) 83 void *v; 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)(void *); 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 opv_desc_vector = malloc(vfs_opv_numops * sizeof(PFI), 122 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)); 127 } 128 129 for (opve_descp = vfs_opv_desc->opv_desc_ops; 130 opve_descp->opve_op; opve_descp++) { 131 /* 132 * Sanity check: is this operation listed 133 * in the list of operations? We check this 134 * by seeing if its offest is zero. Since 135 * the default routine should always be listed 136 * first, it should be the only one with a zero 137 * offset. Any other operation with a zero 138 * offset is probably not listed in 139 * vfs_op_descs, and so is probably an error. 140 * 141 * A panic here means the layer programmer 142 * has committed the all-too common bug 143 * of adding a new operation to the layer's 144 * list of vnode operations but 145 * not adding the operation to the system-wide 146 * list of supported operations. 147 */ 148 if (opve_descp->opve_op->vdesc_offset == 0 && 149 opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) { 150 printf("operation %s not listed in %s.\n", 151 opve_descp->opve_op->vdesc_name, "vfs_op_descs"); 152 panic ("vfs_opv_init: bad operation"); 153 } 154 155 /* 156 * Fill in this entry. 157 */ 158 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 159 opve_descp->opve_impl; 160 } 161 } 162 163 void 164 vfs_opv_init_default(vfs_opv_desc) 165 struct vnodeopv_desc *vfs_opv_desc; 166 { 167 int j; 168 int (**opv_desc_vector)(void *); 169 170 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 171 172 /* 173 * Force every operations vector to have a default routine. 174 */ 175 if (opv_desc_vector[VOFFSET(vop_default)] == NULL) 176 panic("vfs_opv_init: operation vector without default routine."); 177 178 for (j = 0; j < vfs_opv_numops; j++) 179 if (opv_desc_vector[j] == NULL) 180 opv_desc_vector[j] = 181 opv_desc_vector[VOFFSET(vop_default)]; 182 } 183 184 void 185 vfs_opv_init() 186 { 187 int i; 188 189 /* 190 * Allocate the dynamic vectors and fill them in. 191 */ 192 for (i = 0; vfs_opv_descs[i]; i++) 193 vfs_opv_init_explicit(vfs_opv_descs[i]); 194 195 /* 196 * Finally, go back and replace unfilled routines 197 * with their default. 198 */ 199 for (i = 0; vfs_opv_descs[i]; i++) 200 vfs_opv_init_default(vfs_opv_descs[i]); 201 } 202 203 /* 204 * Initialize known vnode operations vectors. 205 */ 206 void 207 vfs_op_init() 208 { 209 int i; 210 211 DODEBUG(printf("Vnode_interface_init.\n")); 212 /* 213 * Set all vnode vectors to a well known value. 214 */ 215 for (i = 0; vfs_opv_descs[i]; i++) 216 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 217 /* 218 * Figure out how many ops there are by counting the table, 219 * and assign each its offset. 220 */ 221 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 222 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 223 vfs_opv_numops++; 224 } 225 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 226 } 227 228 /* 229 * Routines having to do with the management of the vnode table. 230 */ 231 struct vattr va_null; 232 233 /* 234 * Initialize the vnode structures and initialize each file system type. 235 */ 236 void 237 vfsinit() 238 { 239 int i; 240 struct vfsconf *vfsconflist; 241 int vfsconflistlen; 242 243 /* 244 * Initialize the vnode table 245 */ 246 vntblinit(); 247 /* 248 * Initialize the vnode name cache 249 */ 250 nchinit(); 251 /* 252 * Build vnode operation vectors. 253 */ 254 vfs_op_init(); 255 vfs_opv_init(); /* finish the job */ 256 /* 257 * Initialize each file system type. 258 */ 259 vattr_null(&va_null); 260 261 /* 262 * Stop using vfsconf and maxvfsconf as a temporary storage, 263 * set them to their correct values now. 264 */ 265 vfsconflist = vfsconf; 266 vfsconflistlen = maxvfsconf; 267 vfsconf = NULL; 268 maxvfsconf = 0; 269 270 for (i = 0; i < vfsconflistlen; i++) 271 vfs_register(&vfsconflist[i]); 272 } 273