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 * $FreeBSD$ 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 53 MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes"); 54 55 /* 56 * XXX this bloat just exands the sysctl__vfs linker set a little so that 57 * we can attach sysctls for VFS modules without expanding the linker set. 58 * Currently (1998/09/06), only one VFS uses sysctls, so 2 extra linker 59 * set slots are more than sufficient. 60 */ 61 static int mod_xx; 62 SYSCTL_INT(_vfs, OID_AUTO, mod0, CTLFLAG_RD, &mod_xx, 0, ""); 63 SYSCTL_INT(_vfs, OID_AUTO, mod1, CTLFLAG_RD, &mod_xx, 0, ""); 64 65 /* 66 * Zone for namei 67 */ 68 struct vm_zone *namei_zone; 69 70 /* 71 * vfs_init() will set maxvfsconf 72 * to the highest defined type number. 73 */ 74 int maxvfsconf; 75 struct vfsconf *vfsconf; 76 77 /* 78 * vfs_init.c 79 * 80 * Allocate and fill in operations vectors. 81 * 82 * An undocumented feature of this approach to defining operations is that 83 * there can be multiple entries in vfs_opv_descs for the same operations 84 * vector. This allows third parties to extend the set of operations 85 * supported by another layer in a binary compatibile way. For example, 86 * assume that NFS needed to be modified to support Ficus. NFS has an entry 87 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 88 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 89 * listing those new operations Ficus adds to NFS, all without modifying the 90 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 91 * that is a(whole)nother story.) This is a feature. 92 */ 93 94 /* Table of known vnodeop vectors (list of VFS vnode vectors) */ 95 static const struct vnodeopv_desc **vnodeopv_descs; 96 static int vnodeopv_num; 97 98 /* Table of known descs (list of vnode op handlers "vop_access_desc") */ 99 static struct vnodeop_desc **vfs_op_descs; 100 static int *vfs_op_desc_refs; /* reference counts */ 101 static int num_op_descs; 102 static int vfs_opv_numops; 103 104 static void 105 vfs_opv_recalc(void) 106 { 107 int i, j; 108 vop_t ***opv_desc_vector_p; 109 vop_t **opv_desc_vector; 110 struct vnodeopv_entry_desc *opve_descp; 111 const struct vnodeopv_desc *opv; 112 113 if (vfs_op_descs == NULL) 114 panic("vfs_opv_recalc called with null vfs_op_descs"); 115 116 /* 117 * Run through and make sure all known descs have an offset 118 * 119 * vop_default_desc is hardwired at offset 1, and offset 0 120 * is a panic sanity check. 121 */ 122 vfs_opv_numops = 0; 123 for (i = 0; i < num_op_descs; i++) 124 if (vfs_opv_numops < (vfs_op_descs[i]->vdesc_offset + 1)) 125 vfs_opv_numops = vfs_op_descs[i]->vdesc_offset + 1; 126 for (i = 0; i < num_op_descs; i++) 127 if (vfs_op_descs[i]->vdesc_offset == 0) 128 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops++; 129 /* 130 * Allocate and fill in the vectors 131 */ 132 for (i = 0; i < vnodeopv_num; i++) { 133 opv = vnodeopv_descs[i]; 134 opv_desc_vector_p = opv->opv_desc_vector_p; 135 if (*opv_desc_vector_p) 136 FREE(*opv_desc_vector_p, M_VNODE); 137 MALLOC(*opv_desc_vector_p, vop_t **, 138 vfs_opv_numops * sizeof(vop_t *), M_VNODE, M_WAITOK); 139 if (*opv_desc_vector_p == NULL) 140 panic("no memory for vop_t ** vector"); 141 bzero(*opv_desc_vector_p, vfs_opv_numops * sizeof(vop_t *)); 142 143 /* Fill in, with slot 0 being panic */ 144 opv_desc_vector = *opv_desc_vector_p; 145 opv_desc_vector[0] = (vop_t *)vop_panic; 146 for (j = 0; opv->opv_desc_ops[j].opve_op; j++) { 147 opve_descp = &(opv->opv_desc_ops[j]); 148 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 149 opve_descp->opve_impl; 150 } 151 152 /* Replace unfilled routines with their default (slot 1). */ 153 opv_desc_vector = *(opv->opv_desc_vector_p); 154 if (opv_desc_vector[1] == NULL) 155 panic("vfs_opv_recalc: vector without a default."); 156 for (j = 0; j < vfs_opv_numops; j++) 157 if (opv_desc_vector[j] == NULL) 158 opv_desc_vector[j] = opv_desc_vector[1]; 159 } 160 } 161 162 void 163 vfs_add_vnodeops(const void *data) 164 { 165 const struct vnodeopv_desc *opv; 166 const struct vnodeopv_desc **newopv; 167 struct vnodeop_desc **newop; 168 int *newref; 169 vop_t **opv_desc_vector; 170 struct vnodeop_desc *desc; 171 int i, j; 172 173 opv = (const struct vnodeopv_desc *)data; 174 MALLOC(newopv, const struct vnodeopv_desc **, 175 (vnodeopv_num + 1) * sizeof(*newopv), M_VNODE, M_WAITOK); 176 if (newopv == NULL) 177 panic("vfs_add_vnodeops: no memory"); 178 if (vnodeopv_descs) { 179 bcopy(vnodeopv_descs, newopv, vnodeopv_num * sizeof(*newopv)); 180 FREE(vnodeopv_descs, M_VNODE); 181 } 182 newopv[vnodeopv_num] = opv; 183 vnodeopv_descs = newopv; 184 vnodeopv_num++; 185 186 /* See if we have turned up a new vnode op desc */ 187 opv_desc_vector = *(opv->opv_desc_vector_p); 188 for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) { 189 for (j = 0; j < num_op_descs; j++) { 190 if (desc == vfs_op_descs[j]) { 191 /* found it, increase reference count */ 192 vfs_op_desc_refs[j]++; 193 break; 194 } 195 } 196 if (j == num_op_descs) { 197 /* not found, new entry */ 198 MALLOC(newop, struct vnodeop_desc **, 199 (num_op_descs + 1) * sizeof(*newop), 200 M_VNODE, M_WAITOK); 201 if (newop == NULL) 202 panic("vfs_add_vnodeops: no memory for desc"); 203 /* new reference count (for unload) */ 204 MALLOC(newref, int *, 205 (num_op_descs + 1) * sizeof(*newref), 206 M_VNODE, M_WAITOK); 207 if (newref == NULL) 208 panic("vfs_add_vnodeops: no memory for refs"); 209 if (vfs_op_descs) { 210 bcopy(vfs_op_descs, newop, 211 num_op_descs * sizeof(*newop)); 212 FREE(vfs_op_descs, M_VNODE); 213 } 214 if (vfs_op_desc_refs) { 215 bcopy(vfs_op_desc_refs, newref, 216 num_op_descs * sizeof(*newref)); 217 FREE(vfs_op_desc_refs, M_VNODE); 218 } 219 newop[num_op_descs] = desc; 220 newref[num_op_descs] = 1; 221 vfs_op_descs = newop; 222 vfs_op_desc_refs = newref; 223 num_op_descs++; 224 } 225 } 226 vfs_opv_recalc(); 227 } 228 229 void 230 vfs_rm_vnodeops(const void *data) 231 { 232 const struct vnodeopv_desc *opv; 233 const struct vnodeopv_desc **newopv; 234 struct vnodeop_desc **newop; 235 int *newref; 236 vop_t **opv_desc_vector; 237 struct vnodeop_desc *desc; 238 int i, j, k; 239 240 opv = (const struct vnodeopv_desc *)data; 241 /* Lower ref counts on descs in the table and release if zero */ 242 opv_desc_vector = *(opv->opv_desc_vector_p); 243 for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) { 244 for (j = 0; j < num_op_descs; j++) { 245 if (desc == vfs_op_descs[j]) { 246 /* found it, decrease reference count */ 247 vfs_op_desc_refs[j]--; 248 break; 249 } 250 } 251 for (j = 0; j < num_op_descs; j++) { 252 if (vfs_op_desc_refs[j] > 0) 253 continue; 254 if (vfs_op_desc_refs[j] < 0) 255 panic("vfs_remove_vnodeops: negative refcnt"); 256 MALLOC(newop, struct vnodeop_desc **, 257 (num_op_descs - 1) * sizeof(*newop), 258 M_VNODE, M_WAITOK); 259 if (newop == NULL) 260 panic("vfs_remove_vnodeops: no memory for desc"); 261 /* new reference count (for unload) */ 262 MALLOC(newref, int *, 263 (num_op_descs - 1) * sizeof(*newref), 264 M_VNODE, M_WAITOK); 265 if (newref == NULL) 266 panic("vfs_remove_vnodeops: no memory for refs"); 267 for (k = j; k < (num_op_descs - 1); k++) { 268 vfs_op_descs[k] = vfs_op_descs[k + 1]; 269 vfs_op_desc_refs[k] = vfs_op_desc_refs[k + 1]; 270 } 271 bcopy(vfs_op_descs, newop, 272 (num_op_descs - 1) * sizeof(*newop)); 273 bcopy(vfs_op_desc_refs, newref, 274 (num_op_descs - 1) * sizeof(*newref)); 275 FREE(vfs_op_descs, M_VNODE); 276 FREE(vfs_op_desc_refs, M_VNODE); 277 vfs_op_descs = newop; 278 vfs_op_desc_refs = newref; 279 num_op_descs--; 280 } 281 } 282 283 for (i = 0; i < vnodeopv_num; i++) { 284 if (vnodeopv_descs[i] == opv) { 285 for (j = i; j < (vnodeopv_num - 1); j++) 286 vnodeopv_descs[j] = vnodeopv_descs[j + 1]; 287 break; 288 } 289 } 290 if (i == vnodeopv_num) 291 panic("vfs_remove_vnodeops: opv not found"); 292 MALLOC(newopv, const struct vnodeopv_desc **, 293 (vnodeopv_num - 1) * sizeof(*newopv), M_VNODE, M_WAITOK); 294 if (newopv == NULL) 295 panic("vfs_remove_vnodeops: no memory"); 296 bcopy(vnodeopv_descs, newopv, (vnodeopv_num - 1) * sizeof(*newopv)); 297 FREE(vnodeopv_descs, M_VNODE); 298 vnodeopv_descs = newopv; 299 vnodeopv_num--; 300 301 vfs_opv_recalc(); 302 } 303 304 /* 305 * Routines having to do with the management of the vnode table. 306 */ 307 struct vattr va_null; 308 309 /* 310 * Initialize the vnode structures and initialize each file system type. 311 */ 312 /* ARGSUSED*/ 313 static void 314 vfsinit(void *dummy) 315 { 316 317 namei_zone = zinit("NAMEI", MAXPATHLEN, 0, 0, 2); 318 319 /* 320 * Initialize the vnode table 321 */ 322 vntblinit(); 323 /* 324 * Initialize the vnode name cache 325 */ 326 nchinit(); 327 /* 328 * Initialize each file system type. 329 * Vfs type numbers must be distinct from VFS_GENERIC (and VFS_VFSCONF). 330 */ 331 vattr_null(&va_null); 332 maxvfsconf = VFS_GENERIC + 1; 333 } 334 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL) 335 336 int 337 vfs_register(struct vfsconf *vfc) 338 { 339 struct sysctl_oid *oidp; 340 struct vfsconf *vfsp; 341 342 vfsp = NULL; 343 if (vfsconf) 344 for (vfsp = vfsconf; vfsp->vfc_next; vfsp = vfsp->vfc_next) 345 if (strcmp(vfc->vfc_name, vfsp->vfc_name) == 0) 346 return EEXIST; 347 348 vfc->vfc_typenum = maxvfsconf++; 349 if (vfsp) 350 vfsp->vfc_next = vfc; 351 else 352 vfsconf = vfc; 353 vfc->vfc_next = NULL; 354 355 /* 356 * If this filesystem has a sysctl node under vfs 357 * (i.e. vfs.xxfs), then change the oid number of that node to 358 * match the filesystem's type number. This allows user code 359 * which uses the type number to read sysctl variables defined 360 * by the filesystem to continue working. Since the oids are 361 * in a sorted list, we need to make sure the order is 362 * preserved by re-registering the oid after modifying its 363 * number. 364 */ 365 for (oidp = SLIST_FIRST(&sysctl__vfs_children); oidp; 366 oidp = SLIST_NEXT(oidp, oid_link)) 367 if (strcmp(oidp->oid_name, vfc->vfc_name) == 0) { 368 sysctl_unregister_oid(oidp); 369 oidp->oid_number = vfc->vfc_typenum; 370 sysctl_register_oid(oidp); 371 } 372 373 /* 374 * Call init function for this VFS... 375 */ 376 (*(vfc->vfc_vfsops->vfs_init))(vfc); 377 378 return 0; 379 } 380 381 382 int 383 vfs_unregister(struct vfsconf *vfc) 384 { 385 struct vfsconf *vfsp, *prev_vfsp; 386 int error, i, maxtypenum; 387 388 i = vfc->vfc_typenum; 389 390 prev_vfsp = NULL; 391 for (vfsp = vfsconf; vfsp; 392 prev_vfsp = vfsp, vfsp = vfsp->vfc_next) { 393 if (!strcmp(vfc->vfc_name, vfsp->vfc_name)) 394 break; 395 } 396 if (vfsp == NULL) 397 return EINVAL; 398 if (vfsp->vfc_refcount) 399 return EBUSY; 400 if (vfc->vfc_vfsops->vfs_uninit != NULL) { 401 error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp); 402 if (error) 403 return (error); 404 } 405 if (prev_vfsp) 406 prev_vfsp->vfc_next = vfsp->vfc_next; 407 else 408 vfsconf = vfsp->vfc_next; 409 maxtypenum = VFS_GENERIC; 410 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 411 if (maxtypenum < vfsp->vfc_typenum) 412 maxtypenum = vfsp->vfc_typenum; 413 maxvfsconf = maxtypenum + 1; 414 return 0; 415 } 416 417 int 418 vfs_modevent(module_t mod, int type, void *data) 419 { 420 struct vfsconf *vfc; 421 int error = 0; 422 423 vfc = (struct vfsconf *)data; 424 425 switch (type) { 426 case MOD_LOAD: 427 if (vfc) 428 error = vfs_register(vfc); 429 break; 430 431 case MOD_UNLOAD: 432 if (vfc) 433 error = vfs_unregister(vfc); 434 break; 435 default: /* including MOD_SHUTDOWN */ 436 break; 437 } 438 return (error); 439 } 440