vfs_init.c revision 29290
1/* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed 6 * to Berkeley by John Heidemann of the UCLA Ficus project. 7 * 8 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 39 * $Id: vfs_init.c,v 1.26 1997/08/02 14:31:44 bde Exp $ 40 */ 41 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/kernel.h> 46#include <sys/mount.h> 47#include <sys/vnode.h> 48#include <sys/malloc.h> 49 50static void vfs_op_init __P((void)); 51 52static void vfsinit __P((void *)); 53SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL) 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 64struct vfsconf void_vfsconf; 65 66extern struct linker_set vfs_opv_descs_; 67#define vfs_opv_descs ((struct vnodeopv_desc **)vfs_opv_descs_.ls_items) 68 69extern struct linker_set vfs_set; 70 71extern struct vnodeop_desc *vfs_op_descs[]; 72 /* and the operations they perform */ 73 74/* 75 * A miscellaneous routine. 76 * A generic "default" routine that just returns an error. 77 */ 78int 79vn_default_error() 80{ 81 82 return (EOPNOTSUPP); 83} 84 85/* 86 * vfs_init.c 87 * 88 * Allocate and fill in operations vectors. 89 * 90 * An undocumented feature of this approach to defining operations is that 91 * there can be multiple entries in vfs_opv_descs for the same operations 92 * vector. This allows third parties to extend the set of operations 93 * supported by another layer in a binary compatibile way. For example, 94 * assume that NFS needed to be modified to support Ficus. NFS has an entry 95 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 96 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 97 * listing those new operations Ficus adds to NFS, all without modifying the 98 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 99 * that is a(whole)nother story.) This is a feature. 100 * 101 * Without an explicit reserve area, however, you must replace vnode_if.c 102 * and vnode_if.h when you do this, or you will be derefrencing of the 103 * end of vfs_op_descs[]. This is a flaw in the use of a structure 104 * pointer array rather than an agregate to define vfs_op_descs. So 105 * it's not a very dynamic "feature". 106 */ 107void 108vfs_opv_init(struct vnodeopv_desc **them) 109{ 110 int i, j, k; 111 vop_t ***opv_desc_vector_p; 112 vop_t **opv_desc_vector; 113 struct vnodeopv_entry_desc *opve_descp; 114 115 /* 116 * Allocate the dynamic vectors and fill them in. 117 */ 118 for (i=0; them[i]; i++) { 119 opv_desc_vector_p = them[i]->opv_desc_vector_p; 120 /* 121 * Allocate and init the vector, if it needs it. 122 * Also handle backwards compatibility. 123 */ 124 if (*opv_desc_vector_p == NULL) { 125 /* XXX - shouldn't be M_VNODE */ 126 MALLOC(*opv_desc_vector_p, vop_t **, 127 vfs_opv_numops * sizeof(vop_t *), M_VNODE, 128 M_WAITOK); 129 bzero(*opv_desc_vector_p, 130 vfs_opv_numops * sizeof(vop_t *)); 131 DODEBUG(printf("vector at %x allocated\n", 132 opv_desc_vector_p)); 133 } 134 opv_desc_vector = *opv_desc_vector_p; 135 for (j=0; them[i]->opv_desc_ops[j].opve_op; j++) { 136 opve_descp = &(them[i]->opv_desc_ops[j]); 137 138 /* 139 * Sanity check: is this operation listed 140 * in the list of operations? We check this 141 * by seeing if its offest is zero. Since 142 * the default routine should always be listed 143 * first, it should be the only one with a zero 144 * offset. Any other operation with a zero 145 * offset is probably not listed in 146 * vfs_op_descs, and so is probably an error. 147 * 148 * A panic here means the layer programmer 149 * has committed the all-too common bug 150 * of adding a new operation to the layer's 151 * list of vnode operations but 152 * not adding the operation to the system-wide 153 * list of supported operations. 154 */ 155 if (opve_descp->opve_op->vdesc_offset == 0 && 156 opve_descp->opve_op->vdesc_offset != 157 VOFFSET(vop_default)) { 158 printf("operation %s not listed in %s.\n", 159 opve_descp->opve_op->vdesc_name, 160 "vfs_op_descs"); 161 panic ("vfs_opv_init: bad operation"); 162 } 163 /* 164 * Fill in this entry. 165 */ 166 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 167 opve_descp->opve_impl; 168 } 169 } 170 /* 171 * Finally, go back and replace unfilled routines 172 * with their default. (Sigh, an O(n^3) algorithm. I 173 * could make it better, but that'd be work, and n is small.) 174 */ 175 for (i = 0; them[i]; i++) { 176 opv_desc_vector = *(them[i]->opv_desc_vector_p); 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 (k = 0; k<vfs_opv_numops; k++) 184 if (opv_desc_vector[k] == NULL) 185 opv_desc_vector[k] = 186 opv_desc_vector[VOFFSET(vop_default)]; 187 } 188} 189 190/* 191 * Initialize known vnode operations vectors. 192 */ 193static void 194vfs_op_init() 195{ 196 int i; 197 198 DODEBUG(printf("Vnode_interface_init.\n")); 199 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 200 /* 201 * Set all vnode vectors to a well known value. 202 */ 203 for (i = 0; vfs_opv_descs[i]; i++) 204 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 205 /* 206 * assign each op to its offset 207 * 208 * XXX This should not be needed, but is because the per 209 * XXX FS ops tables are not sorted according to the 210 * XXX vnodeop_desc's offset in vfs_op_descs. This 211 * XXX is the same reason we have to take the hit for 212 * XXX the static inline function calls instead of using 213 * XXX simple macro references. 214 */ 215 for (i = 0; i < vfs_opv_numops; i++) 216 vfs_op_descs[i]->vdesc_offset = i; 217} 218 219/* 220 * Routines having to do with the management of the vnode table. 221 */ 222extern struct vnodeops dead_vnodeops; 223extern struct vnodeops spec_vnodeops; 224struct vattr va_null; 225 226/* 227 * Initialize the vnode structures and initialize each file system type. 228 */ 229/* ARGSUSED*/ 230static void 231vfsinit(dummy) 232 void *dummy; 233{ 234 struct vfsconf **vfc; 235 int maxtypenum; 236 237 /* 238 * Initialize the vnode table 239 */ 240 vntblinit(); 241 /* 242 * Initialize the vnode name cache 243 */ 244 nchinit(); 245 /* 246 * Build vnode operation vectors. 247 */ 248 vfs_op_init(); 249 vfs_opv_init(vfs_opv_descs); /* finish the job */ 250 /* 251 * Initialize each file system type. 252 */ 253 vattr_null(&va_null); 254 maxtypenum = 0; 255 vfc = (struct vfsconf **)vfs_set.ls_items; 256 vfsconf = *vfc; /* simulate Lite2 vfsconf array */ 257 while (*vfc) { 258 struct vfsconf *vfsp = *vfc; 259 260 vfc++; 261 vfsp->vfc_next = *vfc; 262 if (maxtypenum <= vfsp->vfc_typenum) 263 maxtypenum = vfsp->vfc_typenum + 1; 264 (*vfsp->vfc_vfsops->vfs_init)(vfsp); 265 } 266 /* next vfc_typenum to be used */ 267 maxvfsconf = maxtypenum; 268} 269 270/* 271 * kernel related system variables. 272 */ 273 274/* 275 * This goop is here to support a loadable NFS module... grumble... 276 */ 277int (*lease_check_hook) __P((struct vop_lease_args *)) 278 = 0; 279void (*lease_updatetime) __P((int)) 280 = 0; 281 282int 283lease_check(ap) 284 struct vop_lease_args /* { 285 struct vnode *a_vp; 286 struct proc *a_p; 287 struct ucred *a_cred; 288 int a_flag; 289 } */ *ap; 290{ 291 if (lease_check_hook) 292 return (*lease_check_hook)(ap); 293 else 294 return 0; 295} 296