1 /* $OpenBSD: vfs_init.c,v 1.22 2008/05/16 17:37:52 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 /* a list of lists of vnodeops defns */ 54 extern struct vnodeopv_desc *vfs_opv_descs[]; 55 56 /* and the operations they perform */ 57 extern struct vnodeop_desc *vfs_op_descs[]; 58 59 struct pool namei_pool; 60 61 /* 62 * This code doesn't work if the defn is **vnodop_defns with cc. 63 * The problem is because of the compiler sometimes putting in an 64 * extra level of indirection for arrays. It's an interesting 65 * "feature" of C. 66 */ 67 int vfs_opv_numops; 68 69 typedef int (*PFI)(void *); 70 71 /* 72 * vfs_init.c 73 * 74 * Allocate and fill in operations vectors. 75 * 76 * An undocumented feature of this approach to defining operations is that 77 * there can be multiple entries in vfs_opv_descs for the same operations 78 * vector. This allows third parties to extend the set of operations 79 * supported by another layer in a binary compatibile way. For example, 80 * assume that NFS needed to be modified to support Ficus. NFS has an entry 81 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 82 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 83 * listing those new operations Ficus adds to NFS, all without modifying the 84 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 85 * that is a(whole)nother story.) This is a feature. 86 */ 87 88 /* 89 * Allocate and init the vector, if it needs it. 90 * Also handle backwards compatibility. 91 */ 92 void 93 vfs_opv_init_explicit(struct vnodeopv_desc *vfs_opv_desc) 94 { 95 int (**opv_desc_vector)(void *); 96 struct vnodeopv_entry_desc *opve_descp; 97 98 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 99 100 if (opv_desc_vector == NULL) { 101 /* XXX - shouldn't be M_VNODE */ 102 opv_desc_vector = malloc(vfs_opv_numops * sizeof(PFI), 103 M_VNODE, M_WAITOK|M_ZERO); 104 *(vfs_opv_desc->opv_desc_vector_p) = opv_desc_vector; 105 } 106 107 for (opve_descp = vfs_opv_desc->opv_desc_ops; 108 opve_descp->opve_op; opve_descp++) { 109 /* 110 * Sanity check: is this operation listed 111 * in the list of operations? We check this 112 * by seeing if its offset is zero. Since 113 * the default routine should always be listed 114 * first, it should be the only one with a zero 115 * offset. Any other operation with a zero 116 * offset is probably not listed in 117 * vfs_op_descs, and so is probably an error. 118 * 119 * A panic here means the layer programmer 120 * has committed the all-too common bug 121 * of adding a new operation to the layer's 122 * list of vnode operations but 123 * not adding the operation to the system-wide 124 * list of supported operations. 125 */ 126 if (opve_descp->opve_op->vdesc_offset == 0 && 127 opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) { 128 printf("operation %s not listed in %s.\n", 129 opve_descp->opve_op->vdesc_name, "vfs_op_descs"); 130 panic ("vfs_opv_init: bad operation"); 131 } 132 133 /* 134 * Fill in this entry. 135 */ 136 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 137 opve_descp->opve_impl; 138 } 139 } 140 141 void 142 vfs_opv_init_default(struct vnodeopv_desc *vfs_opv_desc) 143 { 144 int j; 145 int (**opv_desc_vector)(void *); 146 147 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 148 149 /* 150 * Force every operations vector to have a default routine. 151 */ 152 if (opv_desc_vector[VOFFSET(vop_default)] == NULL) 153 panic("vfs_opv_init: operation vector without default routine."); 154 155 for (j = 0; j < vfs_opv_numops; j++) 156 if (opv_desc_vector[j] == NULL) 157 opv_desc_vector[j] = 158 opv_desc_vector[VOFFSET(vop_default)]; 159 } 160 161 void 162 vfs_opv_init(void) 163 { 164 int i; 165 166 /* 167 * Allocate the dynamic vectors and fill them in. 168 */ 169 for (i = 0; vfs_opv_descs[i]; i++) 170 vfs_opv_init_explicit(vfs_opv_descs[i]); 171 172 /* 173 * Finally, go back and replace unfilled routines 174 * with their default. 175 */ 176 for (i = 0; vfs_opv_descs[i]; i++) 177 vfs_opv_init_default(vfs_opv_descs[i]); 178 } 179 180 /* 181 * Initialize known vnode operations vectors. 182 */ 183 void 184 vfs_op_init(void) 185 { 186 int i; 187 188 /* 189 * Set all vnode vectors to a well known value. 190 */ 191 for (i = 0; vfs_opv_descs[i]; i++) 192 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 193 /* 194 * Figure out how many ops there are by counting the table, 195 * and assign each its offset. 196 */ 197 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 198 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 199 vfs_opv_numops++; 200 } 201 } 202 203 204 /* 205 * Initialize the vnode structures and initialize each file system type. 206 */ 207 void 208 vfsinit(void) 209 { 210 int i; 211 struct vfsconf *vfsconflist; 212 int vfsconflistlen; 213 214 pool_init(&namei_pool, MAXPATHLEN, 0, 0, 0, "namei", 215 &pool_allocator_nointr); 216 217 /* 218 * Initialize the vnode table 219 */ 220 vntblinit(); 221 /* 222 * Initialize the vnode name cache 223 */ 224 nchinit(); 225 /* 226 * Build vnode operation vectors. 227 */ 228 vfs_op_init(); 229 vfs_opv_init(); /* finish the job */ 230 231 /* 232 * Stop using vfsconf and maxvfsconf as a temporary storage, 233 * set them to their correct values now. 234 */ 235 vfsconflist = vfsconf; 236 vfsconflistlen = maxvfsconf; 237 vfsconf = NULL; 238 maxvfsconf = 0; 239 240 for (i = 0; i < vfsconflistlen; i++) 241 vfs_register(&vfsconflist[i]); 242 } 243