1 /* $OpenBSD: vfs_init.c,v 1.19 2007/05/29 16:25:07 thib 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 #include <sys/param.h> 41 #include <sys/mount.h> 42 #include <sys/time.h> 43 #include <sys/vnode.h> 44 #include <sys/stat.h> 45 #include <sys/namei.h> 46 #include <sys/ucred.h> 47 #include <sys/buf.h> 48 #include <sys/errno.h> 49 #include <sys/malloc.h> 50 #include <sys/pool.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(void *v) 83 { 84 85 return (EOPNOTSUPP); 86 } 87 88 /* 89 * vfs_init.c 90 * 91 * Allocate and fill in operations vectors. 92 * 93 * An undocumented feature of this approach to defining operations is that 94 * there can be multiple entries in vfs_opv_descs for the same operations 95 * vector. This allows third parties to extend the set of operations 96 * supported by another layer in a binary compatibile way. For example, 97 * assume that NFS needed to be modified to support Ficus. NFS has an entry 98 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 99 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 100 * listing those new operations Ficus adds to NFS, all without modifying the 101 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 102 * that is a(whole)nother story.) This is a feature. 103 */ 104 105 /* 106 * Allocate and init the vector, if it needs it. 107 * Also handle backwards compatibility. 108 */ 109 void 110 vfs_opv_init_explicit(struct vnodeopv_desc *vfs_opv_desc) 111 { 112 int (**opv_desc_vector)(void *); 113 struct vnodeopv_entry_desc *opve_descp; 114 115 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 116 117 if (opv_desc_vector == NULL) { 118 /* XXX - shouldn't be M_VNODE */ 119 opv_desc_vector = malloc(vfs_opv_numops * sizeof(PFI), 120 M_VNODE, M_WAITOK); 121 bzero(opv_desc_vector, vfs_opv_numops * sizeof(PFI)); 122 *(vfs_opv_desc->opv_desc_vector_p) = opv_desc_vector; 123 DODEBUG(printf("vector at %p allocated\n", 124 opv_desc_vector)); 125 } 126 127 for (opve_descp = vfs_opv_desc->opv_desc_ops; 128 opve_descp->opve_op; opve_descp++) { 129 /* 130 * Sanity check: is this operation listed 131 * in the list of operations? We check this 132 * by seeing if its offset is zero. Since 133 * the default routine should always be listed 134 * first, it should be the only one with a zero 135 * offset. Any other operation with a zero 136 * offset is probably not listed in 137 * vfs_op_descs, and so is probably an error. 138 * 139 * A panic here means the layer programmer 140 * has committed the all-too common bug 141 * of adding a new operation to the layer's 142 * list of vnode operations but 143 * not adding the operation to the system-wide 144 * list of supported operations. 145 */ 146 if (opve_descp->opve_op->vdesc_offset == 0 && 147 opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) { 148 printf("operation %s not listed in %s.\n", 149 opve_descp->opve_op->vdesc_name, "vfs_op_descs"); 150 panic ("vfs_opv_init: bad operation"); 151 } 152 153 /* 154 * Fill in this entry. 155 */ 156 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 157 opve_descp->opve_impl; 158 } 159 } 160 161 void 162 vfs_opv_init_default(struct vnodeopv_desc *vfs_opv_desc) 163 { 164 int j; 165 int (**opv_desc_vector)(void *); 166 167 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 168 169 /* 170 * Force every operations vector to have a default routine. 171 */ 172 if (opv_desc_vector[VOFFSET(vop_default)] == NULL) 173 panic("vfs_opv_init: operation vector without default routine."); 174 175 for (j = 0; j < vfs_opv_numops; j++) 176 if (opv_desc_vector[j] == NULL) 177 opv_desc_vector[j] = 178 opv_desc_vector[VOFFSET(vop_default)]; 179 } 180 181 void 182 vfs_opv_init(void) 183 { 184 int i; 185 186 /* 187 * Allocate the dynamic vectors and fill them in. 188 */ 189 for (i = 0; vfs_opv_descs[i]; i++) 190 vfs_opv_init_explicit(vfs_opv_descs[i]); 191 192 /* 193 * Finally, go back and replace unfilled routines 194 * with their default. 195 */ 196 for (i = 0; vfs_opv_descs[i]; i++) 197 vfs_opv_init_default(vfs_opv_descs[i]); 198 } 199 200 /* 201 * Initialize known vnode operations vectors. 202 */ 203 void 204 vfs_op_init(void) 205 { 206 int i; 207 208 DODEBUG(printf("Vnode_interface_init.\n")); 209 /* 210 * Set all vnode vectors to a well known value. 211 */ 212 for (i = 0; vfs_opv_descs[i]; i++) 213 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 214 /* 215 * Figure out how many ops there are by counting the table, 216 * and assign each its offset. 217 */ 218 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 219 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 220 vfs_opv_numops++; 221 } 222 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 223 } 224 225 /* 226 * Routines having to do with the management of the vnode table. 227 */ 228 struct pool namei_pool; 229 230 /* 231 * Initialize the vnode structures and initialize each file system type. 232 */ 233 void 234 vfsinit(void) 235 { 236 int i; 237 struct vfsconf *vfsconflist; 238 int vfsconflistlen; 239 240 pool_init(&namei_pool, MAXPATHLEN, 0, 0, 0, "namei", 241 &pool_allocator_nointr); 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 /* 258 * Stop using vfsconf and maxvfsconf as a temporary storage, 259 * set them to their correct values now. 260 */ 261 vfsconflist = vfsconf; 262 vfsconflistlen = maxvfsconf; 263 vfsconf = NULL; 264 maxvfsconf = 0; 265 266 for (i = 0; i < vfsconflistlen; i++) 267 vfs_register(&vfsconflist[i]); 268 } 269