vfs_init.c revision 41056
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 1.38 1998/11/04 03:18:10 peter 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 53MALLOC_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 */ 61extern struct linker_set sysctl__vfs; 62static int mod_xx; 63SYSCTL_INT(_vfs, OID_AUTO, mod0, CTLFLAG_RD, &mod_xx, 0, ""); 64SYSCTL_INT(_vfs, OID_AUTO, mod1, CTLFLAG_RD, &mod_xx, 0, ""); 65 66/* 67 * Zone for namei 68 */ 69struct vm_zone *namei_zone; 70 71/* 72 * vfs_init.c 73 * 74 * Allocate and fill in operations vectors. 75 * 76 * An undocumented feature of this approach to defining operations is that 77 * there can be multiple entries in vfs_opv_descs for the same operations 78 * vector. This allows third parties to extend the set of operations 79 * supported by another layer in a binary compatibile way. For example, 80 * assume that NFS needed to be modified to support Ficus. NFS has an entry 81 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 82 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 83 * listing those new operations Ficus adds to NFS, all without modifying the 84 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 85 * that is a(whole)nother story.) This is a feature. 86 */ 87 88/* Table of known vnodeop vectors (list of VFS vnode vectors) */ 89static struct vnodeopv_desc **vnodeopv_descs; 90static int vnodeopv_num; 91 92/* Table of known descs (list of vnode op handlers "vop_access_desc") */ 93static struct vnodeop_desc **vfs_op_descs; 94static int *vfs_op_desc_refs; /* reference counts */ 95static int num_op_descs; 96static int vfs_opv_numops; 97 98static void 99vfs_opv_recalc(void) 100{ 101 int i, j; 102 vop_t ***opv_desc_vector_p; 103 vop_t **opv_desc_vector; 104 struct vnodeopv_entry_desc *opve_descp; 105 struct vnodeopv_desc *opv; 106 107 if (vfs_op_descs == NULL) 108 panic("vfs_opv_recalc called with null vfs_op_descs"); 109 110 /* 111 * Run through and make sure all known descs have an offset 112 * 113 * vop_default_desc is hardwired at offset 1, and offset 0 114 * is a panic sanity check. 115 */ 116 vfs_opv_numops = 0; 117 for (i = 0; i < num_op_descs; i++) 118 if (vfs_opv_numops < (vfs_op_descs[i]->vdesc_offset + 1)) 119 vfs_opv_numops = vfs_op_descs[i]->vdesc_offset + 1; 120 for (i = 0; i < num_op_descs; i++) 121 if (vfs_op_descs[i]->vdesc_offset == 0) 122 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops++; 123 /* 124 * Allocate and fill in the vectors 125 */ 126 for (i = 0; i < vnodeopv_num; i++) { 127 opv = vnodeopv_descs[i]; 128 opv_desc_vector_p = opv->opv_desc_vector_p; 129 if (*opv_desc_vector_p) 130 FREE(*opv_desc_vector_p, M_VNODE); 131 MALLOC(*opv_desc_vector_p, vop_t **, 132 vfs_opv_numops * sizeof(vop_t *), M_VNODE, M_WAITOK); 133 if (*opv_desc_vector_p == NULL) 134 panic("no memory for vop_t ** vector"); 135 bzero(*opv_desc_vector_p, vfs_opv_numops * sizeof(vop_t *)); 136 137 /* Fill in, with slot 0 being panic */ 138 opv_desc_vector = *opv_desc_vector_p; 139 opv_desc_vector[0] = (vop_t *)vop_panic; 140 for (j = 0; opv->opv_desc_ops[j].opve_op; j++) { 141 opve_descp = &(opv->opv_desc_ops[j]); 142 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 143 opve_descp->opve_impl; 144 } 145 146 /* Replace unfilled routines with their default (slot 1). */ 147 opv_desc_vector = *(opv->opv_desc_vector_p); 148 if (opv_desc_vector[1] == NULL) 149 panic("vfs_opv_recalc: vector without a default."); 150 for (j = 0; j < vfs_opv_numops; j++) 151 if (opv_desc_vector[j] == NULL) 152 opv_desc_vector[j] = opv_desc_vector[1]; 153 } 154} 155 156void 157vfs_add_vnodeops(void *data) 158{ 159 struct vnodeopv_desc *opv; 160 struct vnodeopv_desc **newopv; 161 struct vnodeop_desc **newop; 162 int *newref; 163 vop_t **opv_desc_vector; 164 struct vnodeop_desc *desc; 165 struct vnodeopv_entry_desc *opve_descp; 166 int i, j, k; 167 168 opv = (struct vnodeopv_desc *)data; 169 MALLOC(newopv, struct vnodeopv_desc **, 170 (vnodeopv_num + 1) * sizeof(*newopv), M_VNODE, M_WAITOK); 171 if (newopv == NULL) 172 panic("vfs_add_vnodeops: no memory"); 173 if (vnodeopv_descs) { 174 bcopy(vnodeopv_descs, newopv, vnodeopv_num * sizeof(*newopv)); 175 FREE(vnodeopv_descs, M_VNODE); 176 } 177 newopv[vnodeopv_num] = opv; 178 vnodeopv_descs = newopv; 179 vnodeopv_num++; 180 181 /* See if we have turned up a new vnode op desc */ 182 opv_desc_vector = *(opv->opv_desc_vector_p); 183 for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) { 184 for (j = 0; j < num_op_descs; j++) { 185 if (desc == vfs_op_descs[j]) { 186 /* found it, increase reference count */ 187 vfs_op_desc_refs[j]++; 188 break; 189 } 190 } 191 if (j == num_op_descs) { 192 /* not found, new entry */ 193 MALLOC(newop, struct vnodeop_desc **, 194 (num_op_descs + 1) * sizeof(*newop), 195 M_VNODE, M_WAITOK); 196 if (newop == NULL) 197 panic("vfs_add_vnodeops: no memory for desc"); 198 /* new reference count (for unload) */ 199 MALLOC(newref, int *, 200 (num_op_descs + 1) * sizeof(*newref), 201 M_VNODE, M_WAITOK); 202 if (newref == NULL) 203 panic("vfs_add_vnodeops: no memory for refs"); 204 if (vfs_op_descs) { 205 bcopy(vfs_op_descs, newop, 206 num_op_descs * sizeof(*newop)); 207 FREE(vfs_op_descs, M_VNODE); 208 } 209 if (vfs_op_desc_refs) { 210 bcopy(vfs_op_desc_refs, newref, 211 num_op_descs * sizeof(*newref)); 212 FREE(vfs_op_desc_refs, M_VNODE); 213 } 214 newop[num_op_descs] = desc; 215 newref[num_op_descs] = 1; 216 vfs_op_descs = newop; 217 vfs_op_desc_refs = newref; 218 num_op_descs++; 219 } 220 } 221 vfs_opv_recalc(); 222} 223 224void 225vfs_rm_vnodeops(void *data) 226{ 227 struct vnodeopv_desc *opv; 228 struct vnodeopv_desc **newopv; 229 struct vnodeop_desc **newop; 230 int *newref; 231 vop_t **opv_desc_vector; 232 struct vnodeop_desc *desc; 233 struct vnodeopv_entry_desc *opve_descp; 234 int i, j, k; 235 236 opv = (struct vnodeopv_desc *)data; 237 /* Lower ref counts on descs in the table and release if zero */ 238 opv_desc_vector = *(opv->opv_desc_vector_p); 239 for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) { 240 for (j = 0; j < num_op_descs; j++) { 241 if (desc == vfs_op_descs[j]) { 242 /* found it, decrease reference count */ 243 vfs_op_desc_refs[j]--; 244 break; 245 } 246 } 247 for (j = 0; j < num_op_descs; j++) { 248 if (vfs_op_desc_refs[j] > 0) 249 continue; 250 if (vfs_op_desc_refs[j] < 0) 251 panic("vfs_remove_vnodeops: negative refcnt"); 252 MALLOC(newop, struct vnodeop_desc **, 253 (num_op_descs - 1) * sizeof(*newop), 254 M_VNODE, M_WAITOK); 255 if (newop == NULL) 256 panic("vfs_remove_vnodeops: no memory for desc"); 257 /* new reference count (for unload) */ 258 MALLOC(newref, int *, 259 (num_op_descs - 1) * sizeof(*newref), 260 M_VNODE, M_WAITOK); 261 if (newref == NULL) 262 panic("vfs_remove_vnodeops: no memory for refs"); 263 for (k = j; k < (num_op_descs - 1); k++) { 264 vfs_op_descs[k] = vfs_op_descs[k + 1]; 265 vfs_op_desc_refs[k] = vfs_op_desc_refs[k + 1]; 266 } 267 bcopy(vfs_op_descs, newop, 268 (num_op_descs - 1) * sizeof(*newop)); 269 bcopy(vfs_op_desc_refs, newref, 270 (num_op_descs - 1) * sizeof(*newref)); 271 FREE(vfs_op_descs, M_VNODE); 272 FREE(vfs_op_desc_refs, M_VNODE); 273 vfs_op_descs = newop; 274 vfs_op_desc_refs = newref; 275 num_op_descs--; 276 } 277 } 278 279 for (i = 0; i < vnodeopv_num; i++) { 280 if (vnodeopv_descs[i] == opv) { 281 for (j = i; j < (vnodeopv_num - 1); j++) 282 vnodeopv_descs[j] = vnodeopv_descs[j + 1]; 283 break; 284 } 285 } 286 if (i == vnodeopv_num) 287 panic("vfs_remove_vnodeops: opv not found"); 288 MALLOC(newopv, struct vnodeopv_desc **, 289 (vnodeopv_num - 1) * sizeof(*newopv), M_VNODE, M_WAITOK); 290 if (newopv == NULL) 291 panic("vfs_remove_vnodeops: no memory"); 292 bcopy(vnodeopv_descs, newopv, (vnodeopv_num - 1) * sizeof(*newopv)); 293 FREE(vnodeopv_descs, M_VNODE); 294 vnodeopv_descs = newopv; 295 vnodeopv_num--; 296 297 vfs_opv_recalc(); 298} 299 300/* 301 * Routines having to do with the management of the vnode table. 302 */ 303struct vattr va_null; 304 305/* 306 * Initialize the vnode structures and initialize each file system type. 307 */ 308/* ARGSUSED*/ 309static void 310vfsinit(void *dummy) 311{ 312 313 namei_zone = zinit("NAMEI", MAXPATHLEN, 0, 0, 2); 314 315 /* 316 * Initialize the vnode table 317 */ 318 vntblinit(); 319 /* 320 * Initialize the vnode name cache 321 */ 322 nchinit(); 323 /* 324 * Initialize each file system type. 325 * Vfs type numbers must be distinct from VFS_GENERIC (and VFS_VFSCONF). 326 */ 327 vattr_null(&va_null); 328 maxvfsconf = VFS_GENERIC + 1; 329} 330SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL) 331 332int 333vfs_register(struct vfsconf *vfc) 334{ 335 struct linker_set *l; 336 struct sysctl_oid **oidpp; 337 struct vfsconf *vfsp; 338 int i, exists; 339 340 vfsp = NULL; 341 l = &sysctl__vfs; 342 if (vfsconf) 343 for (vfsp = vfsconf; vfsp->vfc_next; vfsp = vfsp->vfc_next) 344 if (!strcmp(vfc->vfc_name, vfsp->vfc_name)) 345 return EEXIST; 346 347 vfc->vfc_typenum = maxvfsconf++; 348 if (vfc->vfc_vfsops->vfs_oid != NULL) { 349 /* 350 * Attach the oid to the "vfs" node of the sysctl tree if 351 * it isn't already there (it will be there for statically 352 * configured vfs's). 353 */ 354 exists = 0; 355 for (i = l->ls_length, 356 oidpp = (struct sysctl_oid **)l->ls_items; 357 i-- != 0; oidpp++) 358 if (*oidpp == vfc->vfc_vfsops->vfs_oid) { 359 exists = 1; 360 break; 361 } 362 if (exists == 0) 363 for (i = l->ls_length, 364 oidpp = (struct sysctl_oid **)l->ls_items; 365 i-- != 0; oidpp++) { 366 if (*oidpp == NULL || 367 *oidpp == &sysctl___vfs_mod0 || 368 *oidpp == &sysctl___vfs_mod1) { 369 *oidpp = vfc->vfc_vfsops->vfs_oid; 370 break; 371 } 372 } 373 374 vfc->vfc_vfsops->vfs_oid->oid_number = vfc->vfc_typenum; 375 sysctl_order_all(); 376 } 377 if (vfsp) 378 vfsp->vfc_next = vfc; 379 else 380 vfsconf = vfc; 381 vfc->vfc_next = NULL; 382 383 /* 384 * Call init function for this VFS... 385 */ 386 (*(vfc->vfc_vfsops->vfs_init))(vfc); 387 388 return 0; 389} 390 391 392int 393vfs_unregister(struct vfsconf *vfc) 394{ 395 struct linker_set *l; 396 struct sysctl_oid **oidpp; 397 struct vfsconf *vfsp, *prev_vfsp; 398 int error, i, maxtypenum; 399 400 i = vfc->vfc_typenum; 401 402 prev_vfsp = NULL; 403 for (vfsp = vfsconf; vfsp; 404 prev_vfsp = vfsp, vfsp = vfsp->vfc_next) { 405 if (!strcmp(vfc->vfc_name, vfsp->vfc_name)) 406 break; 407 } 408 if (vfsp == NULL) 409 return EINVAL; 410 if (vfsp->vfc_refcount) 411 return EBUSY; 412 if (vfc->vfc_vfsops->vfs_uninit != NULL) { 413 error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp); 414 if (error) 415 return (error); 416 } 417 if (prev_vfsp) 418 prev_vfsp->vfc_next = vfsp->vfc_next; 419 else 420 vfsconf = vfsp->vfc_next; 421 if (vfsp->vfc_vfsops->vfs_oid != NULL) { 422 l = &sysctl__vfs; 423 for (i = l->ls_length, 424 oidpp = (struct sysctl_oid **)l->ls_items; 425 i--; oidpp++) { 426 if (*oidpp == vfsp->vfc_vfsops->vfs_oid) { 427 *oidpp = NULL; 428 sysctl_order_all(); 429 break; 430 } 431 } 432 } 433 maxtypenum = VFS_GENERIC; 434 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 435 if (maxtypenum < vfsp->vfc_typenum) 436 maxtypenum = vfsp->vfc_typenum; 437 maxvfsconf = maxtypenum + 1; 438 return 0; 439} 440 441int 442vfs_modevent(module_t mod, modeventtype_t type, void *data) 443{ 444 struct vfsconf *vfc; 445 struct vnodeopv_desc *opv; 446 int i; 447 int error = 0; 448 449 vfc = (struct vfsconf *)data; 450 451 switch (type) { 452 case MOD_LOAD: 453 if (vfc) 454 error = vfs_register(vfc); 455 break; 456 457 case MOD_UNLOAD: 458 if (vfc) 459 error = vfs_unregister(vfc); 460 break; 461 default: /* including MOD_SHUTDOWN */ 462 break; 463 } 464 return (error); 465} 466