vfs_init.c revision 39975
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 1.33 1998/09/05 17:13:27 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/sysctl.h> 48#include <sys/vnode.h> 49#include <sys/malloc.h> 50#include <vm/vm_zone.h> 51 52static void vfs_op_init __P((void)); 53 54static void vfsinit __P((void *)); 55SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL) 56 57MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes"); 58 59/* 60 * Sigh, such primitive tools are these... 61 */ 62#if 0 63#define DODEBUG(A) A 64#else 65#define DODEBUG(A) 66#endif 67 68static struct vfsconf void_vfsconf; 69 70extern struct linker_set vfs_opv_descs_; 71#define vfs_opv_descs ((struct vnodeopv_desc **)vfs_opv_descs_.ls_items) 72 73extern struct linker_set vfs_set; 74 75extern struct vnodeop_desc *vfs_op_descs[]; 76 /* and the operations they perform */ 77 78/* 79 * Zone for namei 80 */ 81struct vm_zone *namei_zone; 82 83/* 84 * vfs_init.c 85 * 86 * Allocate and fill in operations vectors. 87 * 88 * An undocumented feature of this approach to defining operations is that 89 * there can be multiple entries in vfs_opv_descs for the same operations 90 * vector. This allows third parties to extend the set of operations 91 * supported by another layer in a binary compatibile way. For example, 92 * assume that NFS needed to be modified to support Ficus. NFS has an entry 93 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 94 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 95 * listing those new operations Ficus adds to NFS, all without modifying the 96 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 97 * that is a(whole)nother story.) This is a feature. 98 * 99 * Without an explicit reserve area, however, you must replace vnode_if.c 100 * and vnode_if.h when you do this, or you will be derefrencing of the 101 * end of vfs_op_descs[]. This is a flaw in the use of a structure 102 * pointer array rather than an agregate to define vfs_op_descs. So 103 * it's not a very dynamic "feature". 104 */ 105void 106vfs_opv_init(struct vnodeopv_desc **them) 107{ 108 int i, j, k; 109 vop_t ***opv_desc_vector_p; 110 vop_t **opv_desc_vector; 111 struct vnodeopv_entry_desc *opve_descp; 112 113 /* 114 * Allocate the dynamic vectors and fill them in. 115 */ 116 for (i=0; them[i]; i++) { 117 opv_desc_vector_p = them[i]->opv_desc_vector_p; 118 /* 119 * Allocate and init the vector, if it needs it. 120 * Also handle backwards compatibility. 121 */ 122 if (*opv_desc_vector_p == NULL) { 123 /* XXX - shouldn't be M_VNODE */ 124 MALLOC(*opv_desc_vector_p, vop_t **, 125 vfs_opv_numops * sizeof(vop_t *), M_VNODE, 126 M_WAITOK); 127 bzero(*opv_desc_vector_p, 128 vfs_opv_numops * sizeof(vop_t *)); 129 DODEBUG(printf("vector at %x allocated\n", 130 opv_desc_vector_p)); 131 } 132 opv_desc_vector = *opv_desc_vector_p; 133 for (j=0; them[i]->opv_desc_ops[j].opve_op; j++) { 134 opve_descp = &(them[i]->opv_desc_ops[j]); 135 136 /* 137 * Sanity check: is this operation listed 138 * in the list of operations? We check this 139 * by seeing if its offest is zero. Since 140 * the default routine should always be listed 141 * first, it should be the only one with a zero 142 * offset. Any other operation with a zero 143 * offset is probably not listed in 144 * vfs_op_descs, and so is probably an error. 145 * 146 * A panic here means the layer programmer 147 * has committed the all-too common bug 148 * of adding a new operation to the layer's 149 * list of vnode operations but 150 * not adding the operation to the system-wide 151 * list of supported operations. 152 */ 153 if (opve_descp->opve_op->vdesc_offset == 0 && 154 opve_descp->opve_op->vdesc_offset != 155 VOFFSET(vop_default)) { 156 printf("operation %s not listed in %s.\n", 157 opve_descp->opve_op->vdesc_name, 158 "vfs_op_descs"); 159 panic ("vfs_opv_init: bad operation"); 160 } 161 /* 162 * Fill in this entry. 163 */ 164 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 165 opve_descp->opve_impl; 166 } 167 } 168 /* 169 * Finally, go back and replace unfilled routines 170 * with their default. (Sigh, an O(n^3) algorithm. I 171 * could make it better, but that'd be work, and n is small.) 172 */ 173 for (i = 0; them[i]; i++) { 174 opv_desc_vector = *(them[i]->opv_desc_vector_p); 175 /* 176 * Force every operations vector to have a default routine. 177 */ 178 if (opv_desc_vector[VOFFSET(vop_default)]==NULL) { 179 panic("vfs_opv_init: operation vector without default routine."); 180 } 181 for (k = 0; k<vfs_opv_numops; k++) 182 if (opv_desc_vector[k] == NULL) 183 opv_desc_vector[k] = 184 opv_desc_vector[VOFFSET(vop_default)]; 185 } 186} 187 188/* 189 * Initialize known vnode operations vectors. 190 */ 191static void 192vfs_op_init() 193{ 194 int i; 195 196 DODEBUG(printf("Vnode_interface_init.\n")); 197 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 198 /* 199 * Set all vnode vectors to a well known value. 200 */ 201 for (i = 0; vfs_opv_descs[i]; i++) 202 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 203 /* 204 * assign each op to its offset 205 * 206 * XXX This should not be needed, but is because the per 207 * XXX FS ops tables are not sorted according to the 208 * XXX vnodeop_desc's offset in vfs_op_descs. This 209 * XXX is the same reason we have to take the hit for 210 * XXX the static inline function calls instead of using 211 * XXX simple macro references. 212 */ 213 for (i = 0; i < vfs_opv_numops; i++) 214 vfs_op_descs[i]->vdesc_offset = i; 215} 216 217/* 218 * Routines having to do with the management of the vnode table. 219 */ 220extern struct vnodeops dead_vnodeops; 221extern struct vnodeops spec_vnodeops; 222struct vattr va_null; 223 224/* 225 * Initialize the vnode structures and initialize each file system type. 226 */ 227/* ARGSUSED*/ 228static void 229vfsinit(dummy) 230 void *dummy; 231{ 232 struct vfsconf **vfc, *vfsp; 233 int maxtypenum; 234 235 namei_zone = zinit("NAMEI", MAXPATHLEN, 0, 0, 2); 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 * Vfs type numbers must be distinct from VFS_GENERIC (and VFS_VFSCONF). 253 */ 254 vattr_null(&va_null); 255 maxtypenum = VFS_GENERIC + 1; 256 vfc = (struct vfsconf **)vfs_set.ls_items; 257 vfsconf = *vfc; 258 for (; *vfc != NULL; maxtypenum++, vfc++) { 259 vfsp = *vfc; 260 vfsp->vfc_next = *(vfc + 1); 261 vfsp->vfc_typenum = maxtypenum; 262 if (vfsp->vfc_vfsops->vfs_oid != NULL) { 263 vfsp->vfc_vfsops->vfs_oid->oid_number = maxtypenum; 264 sysctl_order_all(); 265 } 266 (*vfsp->vfc_vfsops->vfs_init)(vfsp); 267 } 268 /* next vfc_typenum to be used */ 269 maxvfsconf = maxtypenum; 270} 271 272