vfs_init.c revision 30354
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 1.28 1997/09/21 04:22:59 dyson 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#include <vm/vm_zone.h> 50 51static void vfs_op_init __P((void)); 52 53static void vfsinit __P((void *)); 54SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL) 55 56MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes"); 57 58/* 59 * Sigh, such primitive tools are these... 60 */ 61#if 0 62#define DODEBUG(A) A 63#else 64#define DODEBUG(A) 65#endif 66 67struct vfsconf void_vfsconf; 68 69extern struct linker_set vfs_opv_descs_; 70#define vfs_opv_descs ((struct vnodeopv_desc **)vfs_opv_descs_.ls_items) 71 72extern struct linker_set vfs_set; 73 74extern struct vnodeop_desc *vfs_op_descs[]; 75 /* and the operations they perform */ 76 77/* 78 * Zone for namei 79 */ 80struct vm_zone *namei_zone; 81 82/* 83 * A miscellaneous routine. 84 * A generic "default" routine that just returns an error. 85 */ 86int 87vn_default_error() 88{ 89 90 return (EOPNOTSUPP); 91} 92 93/* 94 * vfs_init.c 95 * 96 * Allocate and fill in operations vectors. 97 * 98 * An undocumented feature of this approach to defining operations is that 99 * there can be multiple entries in vfs_opv_descs for the same operations 100 * vector. This allows third parties to extend the set of operations 101 * supported by another layer in a binary compatibile way. For example, 102 * assume that NFS needed to be modified to support Ficus. NFS has an entry 103 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 104 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 105 * listing those new operations Ficus adds to NFS, all without modifying the 106 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 107 * that is a(whole)nother story.) This is a feature. 108 * 109 * Without an explicit reserve area, however, you must replace vnode_if.c 110 * and vnode_if.h when you do this, or you will be derefrencing of the 111 * end of vfs_op_descs[]. This is a flaw in the use of a structure 112 * pointer array rather than an agregate to define vfs_op_descs. So 113 * it's not a very dynamic "feature". 114 */ 115void 116vfs_opv_init(struct vnodeopv_desc **them) 117{ 118 int i, j, k; 119 vop_t ***opv_desc_vector_p; 120 vop_t **opv_desc_vector; 121 struct vnodeopv_entry_desc *opve_descp; 122 123 /* 124 * Allocate the dynamic vectors and fill them in. 125 */ 126 for (i=0; them[i]; i++) { 127 opv_desc_vector_p = them[i]->opv_desc_vector_p; 128 /* 129 * Allocate and init the vector, if it needs it. 130 * Also handle backwards compatibility. 131 */ 132 if (*opv_desc_vector_p == NULL) { 133 /* XXX - shouldn't be M_VNODE */ 134 MALLOC(*opv_desc_vector_p, vop_t **, 135 vfs_opv_numops * sizeof(vop_t *), M_VNODE, 136 M_WAITOK); 137 bzero(*opv_desc_vector_p, 138 vfs_opv_numops * sizeof(vop_t *)); 139 DODEBUG(printf("vector at %x allocated\n", 140 opv_desc_vector_p)); 141 } 142 opv_desc_vector = *opv_desc_vector_p; 143 for (j=0; them[i]->opv_desc_ops[j].opve_op; j++) { 144 opve_descp = &(them[i]->opv_desc_ops[j]); 145 146 /* 147 * Sanity check: is this operation listed 148 * in the list of operations? We check this 149 * by seeing if its offest is zero. Since 150 * the default routine should always be listed 151 * first, it should be the only one with a zero 152 * offset. Any other operation with a zero 153 * offset is probably not listed in 154 * vfs_op_descs, and so is probably an error. 155 * 156 * A panic here means the layer programmer 157 * has committed the all-too common bug 158 * of adding a new operation to the layer's 159 * list of vnode operations but 160 * not adding the operation to the system-wide 161 * list of supported operations. 162 */ 163 if (opve_descp->opve_op->vdesc_offset == 0 && 164 opve_descp->opve_op->vdesc_offset != 165 VOFFSET(vop_default)) { 166 printf("operation %s not listed in %s.\n", 167 opve_descp->opve_op->vdesc_name, 168 "vfs_op_descs"); 169 panic ("vfs_opv_init: bad operation"); 170 } 171 /* 172 * Fill in this entry. 173 */ 174 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 175 opve_descp->opve_impl; 176 } 177 } 178 /* 179 * Finally, go back and replace unfilled routines 180 * with their default. (Sigh, an O(n^3) algorithm. I 181 * could make it better, but that'd be work, and n is small.) 182 */ 183 for (i = 0; them[i]; i++) { 184 opv_desc_vector = *(them[i]->opv_desc_vector_p); 185 /* 186 * Force every operations vector to have a default routine. 187 */ 188 if (opv_desc_vector[VOFFSET(vop_default)]==NULL) { 189 panic("vfs_opv_init: operation vector without default routine."); 190 } 191 for (k = 0; k<vfs_opv_numops; k++) 192 if (opv_desc_vector[k] == NULL) 193 opv_desc_vector[k] = 194 opv_desc_vector[VOFFSET(vop_default)]; 195 } 196} 197 198/* 199 * Initialize known vnode operations vectors. 200 */ 201static void 202vfs_op_init() 203{ 204 int i; 205 206 DODEBUG(printf("Vnode_interface_init.\n")); 207 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 208 /* 209 * Set all vnode vectors to a well known value. 210 */ 211 for (i = 0; vfs_opv_descs[i]; i++) 212 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 213 /* 214 * assign each op to its offset 215 * 216 * XXX This should not be needed, but is because the per 217 * XXX FS ops tables are not sorted according to the 218 * XXX vnodeop_desc's offset in vfs_op_descs. This 219 * XXX is the same reason we have to take the hit for 220 * XXX the static inline function calls instead of using 221 * XXX simple macro references. 222 */ 223 for (i = 0; i < vfs_opv_numops; i++) 224 vfs_op_descs[i]->vdesc_offset = i; 225} 226 227/* 228 * Routines having to do with the management of the vnode table. 229 */ 230extern struct vnodeops dead_vnodeops; 231extern struct vnodeops spec_vnodeops; 232struct vattr va_null; 233 234/* 235 * Initialize the vnode structures and initialize each file system type. 236 */ 237/* ARGSUSED*/ 238static void 239vfsinit(dummy) 240 void *dummy; 241{ 242 struct vfsconf **vfc; 243 int maxtypenum; 244 245 namei_zone = zinit("NAMEI", MAXPATHLEN, 0, 0, 2); 246 247 /* 248 * Initialize the vnode table 249 */ 250 vntblinit(); 251 /* 252 * Initialize the vnode name cache 253 */ 254 nchinit(); 255 /* 256 * Build vnode operation vectors. 257 */ 258 vfs_op_init(); 259 vfs_opv_init(vfs_opv_descs); /* finish the job */ 260 /* 261 * Initialize each file system type. 262 */ 263 vattr_null(&va_null); 264 maxtypenum = 0; 265 vfc = (struct vfsconf **)vfs_set.ls_items; 266 vfsconf = *vfc; /* simulate Lite2 vfsconf array */ 267 while (*vfc) { 268 struct vfsconf *vfsp = *vfc; 269 270 vfc++; 271 vfsp->vfc_next = *vfc; 272 if (maxtypenum <= vfsp->vfc_typenum) 273 maxtypenum = vfsp->vfc_typenum + 1; 274 (*vfsp->vfc_vfsops->vfs_init)(vfsp); 275 } 276 /* next vfc_typenum to be used */ 277 maxvfsconf = maxtypenum; 278} 279 280/* 281 * kernel related system variables. 282 */ 283 284/* 285 * This goop is here to support a loadable NFS module... grumble... 286 */ 287int (*lease_check_hook) __P((struct vop_lease_args *)) 288 = 0; 289void (*lease_updatetime) __P((int)) 290 = 0; 291 292int 293lease_check(ap) 294 struct vop_lease_args /* { 295 struct vnode *a_vp; 296 struct proc *a_p; 297 struct ucred *a_cred; 298 int a_flag; 299 } */ *ap; 300{ 301 if (lease_check_hook) 302 return (*lease_check_hook)(ap); 303 else 304 return 0; 305} 306