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 1.37 1998/10/25 17:44:52 phk 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 52 static void vfs_op_init __P((void)); 53 54 static void vfsinit __P((void *)); 55 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL) 56 57 MALLOC_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 68 extern struct vnodeop_desc *vfs_op_descs[]; 69 /* and the operations they perform */ 70 71 /* 72 * XXX this bloat just exands the sysctl__vfs linker set a little so that 73 * we can attach sysctls for VFS modules without expanding the linker set. 74 * Currently (1998/09/06), only one VFS uses sysctls, so 2 extra linker 75 * set slots are more than sufficient. 76 */ 77 extern struct linker_set sysctl__vfs; 78 static int mod_xx; 79 SYSCTL_INT(_vfs, OID_AUTO, mod0, CTLFLAG_RD, &mod_xx, 0, ""); 80 SYSCTL_INT(_vfs, OID_AUTO, mod1, CTLFLAG_RD, &mod_xx, 0, ""); 81 82 /* 83 * Zone for namei 84 */ 85 struct vm_zone *namei_zone; 86 87 /* 88 * vfs_init.c 89 * 90 * Allocate and fill in operations vectors. 91 * 92 * An undocumented feature of this approach to defining operations is that 93 * there can be multiple entries in vfs_opv_descs for the same operations 94 * vector. This allows third parties to extend the set of operations 95 * supported by another layer in a binary compatibile way. For example, 96 * assume that NFS needed to be modified to support Ficus. NFS has an entry 97 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 98 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 99 * listing those new operations Ficus adds to NFS, all without modifying the 100 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 101 * that is a(whole)nother story.) This is a feature. 102 * 103 * Without an explicit reserve area, however, you must replace vnode_if.c 104 * and vnode_if.h when you do this, or you will be derefrencing of the 105 * end of vfs_op_descs[]. This is a flaw in the use of a structure 106 * pointer array rather than an agregate to define vfs_op_descs. So 107 * it's not a very dynamic "feature". 108 */ 109 void 110 vfs_opv_init(struct vnodeopv_desc *opv) 111 { 112 int j; 113 vop_t ***opv_desc_vector_p; 114 vop_t **opv_desc_vector; 115 struct vnodeopv_entry_desc *opve_descp; 116 int default_vector; 117 118 default_vector = VOFFSET(vop_default); 119 /* 120 * Allocate the dynamic vectors and fill them in. 121 */ 122 opv_desc_vector_p = opv->opv_desc_vector_p; 123 /* 124 * Allocate and init the vector, if it needs it. 125 * Also handle backwards compatibility. 126 */ 127 if (*opv_desc_vector_p == NULL) { 128 /* XXX - shouldn't be M_VNODE */ 129 MALLOC(*opv_desc_vector_p, vop_t **, 130 vfs_opv_numops * sizeof(vop_t *), M_VNODE, M_WAITOK); 131 bzero(*opv_desc_vector_p, 132 vfs_opv_numops * sizeof(vop_t *)); 133 DODEBUG(printf("vector at %x allocated\n", 134 opv_desc_vector_p)); 135 } 136 opv_desc_vector = *opv_desc_vector_p; 137 for (j = 0; opv->opv_desc_ops[j].opve_op; j++) { 138 opve_descp = &(opv->opv_desc_ops[j]); 139 140 /* 141 * Sanity check: is this operation listed 142 * in the list of operations? We check this 143 * by seeing if its offest is zero. Since 144 * the default routine should always be listed 145 * first, it should be the only one with a zero 146 * offset. Any other operation with a zero 147 * offset is probably not listed in 148 * vfs_op_descs, and so is probably an error. 149 * 150 * A panic here means the layer programmer 151 * has committed the all-too common bug 152 * of adding a new operation to the layer's 153 * list of vnode operations but 154 * not adding the operation to the system-wide 155 * list of supported operations. 156 */ 157 if (opve_descp->opve_op->vdesc_offset == 0 && 158 opve_descp->opve_op->vdesc_offset != default_vector) { 159 printf("operation %s not listed in vfs_op_descs[].\n", 160 opve_descp->opve_op->vdesc_name); 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 * Finally, go back and replace unfilled routines with their default. 171 */ 172 opv_desc_vector = *(opv->opv_desc_vector_p); 173 if (opv_desc_vector[default_vector] == NULL) 174 panic("vfs_opv_init: operation vector without a default."); 175 for (j = 0; j < vfs_opv_numops; j++) 176 if (opv_desc_vector[j] == NULL) 177 opv_desc_vector[j] = opv_desc_vector[default_vector]; 178 } 179 180 /* 181 * Initialize known vnode operations vectors. 182 */ 183 static void 184 vfs_op_init() 185 { 186 int i; 187 188 DODEBUG(printf("Vnode_interface_init.\n")); 189 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 190 /* 191 * assign each op to its offset 192 * 193 * XXX This should not be needed, but is because the per 194 * XXX FS ops tables are not sorted according to the 195 * XXX vnodeop_desc's offset in vfs_op_descs. This 196 * XXX is the same reason we have to take the hit for 197 * XXX the static inline function calls instead of using 198 * XXX simple macro references. 199 */ 200 for (i = 0; i < vfs_opv_numops; i++) 201 vfs_op_descs[i]->vdesc_offset = i; 202 } 203 204 /* 205 * Routines having to do with the management of the vnode table. 206 */ 207 extern struct vnodeops dead_vnodeops; 208 extern struct vnodeops spec_vnodeops; 209 struct vattr va_null; 210 211 /* 212 * Initialize the vnode structures and initialize each file system type. 213 */ 214 /* ARGSUSED*/ 215 static void 216 vfsinit(dummy) 217 void *dummy; 218 { 219 220 namei_zone = zinit("NAMEI", MAXPATHLEN, 0, 0, 2); 221 222 /* 223 * Initialize the vnode table 224 */ 225 vntblinit(); 226 /* 227 * Initialize the vnode name cache 228 */ 229 nchinit(); 230 /* 231 * Build vnode operation vectors. 232 */ 233 vfs_op_init(); 234 /* 235 * Initialize each file system type. 236 * Vfs type numbers must be distinct from VFS_GENERIC (and VFS_VFSCONF). 237 */ 238 vattr_null(&va_null); 239 maxvfsconf = VFS_GENERIC + 1; 240 } 241 242 int 243 vfs_register(vfc) 244 struct vfsconf *vfc; 245 { 246 struct linker_set *l; 247 struct sysctl_oid **oidpp; 248 struct vfsconf *vfsp; 249 int i, exists; 250 251 vfsp = NULL; 252 l = &sysctl__vfs; 253 if (vfsconf) 254 for (vfsp = vfsconf; vfsp->vfc_next; vfsp = vfsp->vfc_next) 255 if (!strcmp(vfc->vfc_name, vfsp->vfc_name)) 256 return EEXIST; 257 258 vfc->vfc_typenum = maxvfsconf++; 259 if (vfc->vfc_vfsops->vfs_oid != NULL) { 260 /* 261 * Attach the oid to the "vfs" node of the sysctl tree if 262 * it isn't already there (it will be there for statically 263 * configured vfs's). 264 */ 265 exists = 0; 266 for (i = l->ls_length, 267 oidpp = (struct sysctl_oid **)l->ls_items; 268 i-- != 0; oidpp++) 269 if (*oidpp == vfc->vfc_vfsops->vfs_oid) { 270 exists = 1; 271 break; 272 } 273 if (exists == 0) 274 for (i = l->ls_length, 275 oidpp = (struct sysctl_oid **)l->ls_items; 276 i-- != 0; oidpp++) { 277 if (*oidpp == NULL || 278 *oidpp == &sysctl___vfs_mod0 || 279 *oidpp == &sysctl___vfs_mod1) { 280 *oidpp = vfc->vfc_vfsops->vfs_oid; 281 break; 282 } 283 } 284 285 vfc->vfc_vfsops->vfs_oid->oid_number = vfc->vfc_typenum; 286 sysctl_order_all(); 287 } 288 if (vfsp) 289 vfsp->vfc_next = vfc; 290 else 291 vfsconf = vfc; 292 vfc->vfc_next = NULL; 293 294 /* 295 * Call init function for this VFS... 296 */ 297 (*(vfc->vfc_vfsops->vfs_init))(vfc); 298 299 return 0; 300 } 301 302 303 /* 304 * To be called at SI_SUB_VFS, SECOND, for each VFS before any are registered. 305 */ 306 void 307 vfs_mod_opv_init(handle) 308 void *handle; 309 { 310 struct vnodeopv_desc *opv; 311 312 opv = (struct vnodeopv_desc *)handle; 313 *(opv->opv_desc_vector_p) = NULL; 314 315 /* XXX there is a memory leak on unload here */ 316 vfs_opv_init(opv); 317 } 318 319 int 320 vfs_unregister(vfc) 321 struct vfsconf *vfc; 322 { 323 struct linker_set *l; 324 struct sysctl_oid **oidpp; 325 struct vfsconf *vfsp, *prev_vfsp; 326 int error, i, maxtypenum; 327 328 i = vfc->vfc_typenum; 329 330 prev_vfsp = NULL; 331 for (vfsp = vfsconf; vfsp; 332 prev_vfsp = vfsp, vfsp = vfsp->vfc_next) { 333 if (!strcmp(vfc->vfc_name, vfsp->vfc_name)) 334 break; 335 } 336 if (vfsp == NULL) 337 return EINVAL; 338 if (vfsp->vfc_refcount) 339 return EBUSY; 340 if (vfc->vfc_vfsops->vfs_uninit != NULL) { 341 error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp); 342 if (error) 343 return (error); 344 } 345 if (prev_vfsp) 346 prev_vfsp->vfc_next = vfsp->vfc_next; 347 else 348 vfsconf = vfsp->vfc_next; 349 if (vfsp->vfc_vfsops->vfs_oid != NULL) { 350 l = &sysctl__vfs; 351 for (i = l->ls_length, 352 oidpp = (struct sysctl_oid **)l->ls_items; 353 i--; oidpp++) { 354 if (*oidpp == vfsp->vfc_vfsops->vfs_oid) { 355 *oidpp = NULL; 356 sysctl_order_all(); 357 break; 358 } 359 } 360 } 361 maxtypenum = VFS_GENERIC; 362 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 363 if (maxtypenum < vfsp->vfc_typenum) 364 maxtypenum = vfsp->vfc_typenum; 365 maxvfsconf = maxtypenum + 1; 366 return 0; 367 } 368