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 51 52 MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes"); 53 54 /* 55 * The highest defined VFS number. 56 */ 57 int maxvfsconf = VFS_GENERIC + 1; 58 59 /* 60 * Single-linked list of configured VFSes. 61 * New entries are added/deleted by vfs_register()/vfs_unregister() 62 */ 63 struct vfsconf *vfsconf; 64 65 /* 66 * vfs_init.c 67 * 68 * Allocate and fill in operations vectors. 69 * 70 * An undocumented feature of this approach to defining operations is that 71 * there can be multiple entries in vfs_opv_descs for the same operations 72 * vector. This allows third parties to extend the set of operations 73 * supported by another layer in a binary compatibile way. For example, 74 * assume that NFS needed to be modified to support Ficus. NFS has an entry 75 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 76 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 77 * listing those new operations Ficus adds to NFS, all without modifying the 78 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 79 * that is a(whole)nother story.) This is a feature. 80 */ 81 82 /* Table of known vnodeop vectors (list of VFS vnode vectors) */ 83 static const struct vnodeopv_desc **vnodeopv_descs; 84 static int vnodeopv_num; 85 86 /* Table of known descs (list of vnode op handlers "vop_access_desc") */ 87 static struct vnodeop_desc **vfs_op_descs; 88 /* Reference counts for vfs_op_descs */ 89 static int *vfs_op_desc_refs; 90 /* Number of descriptions */ 91 static int num_op_descs; 92 /* Number of entries in each description */ 93 static int vfs_opv_numops; 94 95 /* 96 * Recalculate the operations vector/description (those parts of it that can 97 * be recalculated, that is.) 98 * XXX It may be preferable to replace this function with an invariant check 99 * and a set of functions that should keep the table invariant. 100 */ 101 static void 102 vfs_opv_recalc(void) 103 { 104 int i, j; 105 vop_t ***opv_desc_vector_p; 106 vop_t **opv_desc_vector; 107 struct vnodeopv_entry_desc *opve_descp; 108 const struct vnodeopv_desc *opv; 109 110 if (vfs_op_descs == NULL) 111 panic("vfs_opv_recalc called with null vfs_op_descs"); 112 113 /* 114 * Run through and make sure all known descs have an offset 115 * 116 * vop_default_desc is hardwired at offset 1, and offset 0 117 * is a panic sanity check. 118 */ 119 vfs_opv_numops = 0; 120 for (i = 0; i < num_op_descs; i++) 121 if (vfs_opv_numops < (vfs_op_descs[i]->vdesc_offset + 1)) 122 vfs_opv_numops = vfs_op_descs[i]->vdesc_offset + 1; 123 for (i = 0; i < num_op_descs; i++) 124 if (vfs_op_descs[i]->vdesc_offset == 0) 125 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops++; 126 /* 127 * Allocate and fill in the vectors 128 */ 129 for (i = 0; i < vnodeopv_num; i++) { 130 opv = vnodeopv_descs[i]; 131 opv_desc_vector_p = opv->opv_desc_vector_p; 132 if (*opv_desc_vector_p) 133 FREE(*opv_desc_vector_p, M_VNODE); 134 MALLOC(*opv_desc_vector_p, vop_t **, 135 vfs_opv_numops * sizeof(vop_t *), M_VNODE, 136 M_WAITOK | M_ZERO); 137 if (*opv_desc_vector_p == NULL) 138 panic("no memory for vop_t ** vector"); 139 140 /* Fill in, with slot 0 being to return EOPNOTSUPP */ 141 opv_desc_vector = *opv_desc_vector_p; 142 opv_desc_vector[0] = (vop_t *)vop_eopnotsupp; 143 for (j = 0; opv->opv_desc_ops[j].opve_op; j++) { 144 opve_descp = &(opv->opv_desc_ops[j]); 145 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 146 opve_descp->opve_impl; 147 } 148 149 /* Replace unfilled routines with their default (slot 1). */ 150 opv_desc_vector = *(opv->opv_desc_vector_p); 151 if (opv_desc_vector[1] == NULL) 152 panic("vfs_opv_recalc: vector without a default."); 153 for (j = 0; j < vfs_opv_numops; j++) 154 if (opv_desc_vector[j] == NULL) 155 opv_desc_vector[j] = opv_desc_vector[1]; 156 } 157 } 158 159 /* Add a set of vnode operations (a description) to the table above. */ 160 void 161 vfs_add_vnodeops(const void *data) 162 { 163 const struct vnodeopv_desc *opv; 164 const struct vnodeopv_desc **newopv; 165 struct vnodeop_desc **newop; 166 int *newref; 167 vop_t **opv_desc_vector; 168 struct vnodeop_desc *desc; 169 int i, j; 170 171 opv = (const struct vnodeopv_desc *)data; 172 MALLOC(newopv, const struct vnodeopv_desc **, 173 (vnodeopv_num + 1) * sizeof(*newopv), M_VNODE, M_WAITOK); 174 if (newopv == NULL) 175 panic("vfs_add_vnodeops: no memory"); 176 if (vnodeopv_descs) { 177 bcopy(vnodeopv_descs, newopv, vnodeopv_num * sizeof(*newopv)); 178 FREE(vnodeopv_descs, M_VNODE); 179 } 180 newopv[vnodeopv_num] = opv; 181 vnodeopv_descs = newopv; 182 vnodeopv_num++; 183 184 /* See if we have turned up a new vnode op desc */ 185 opv_desc_vector = *(opv->opv_desc_vector_p); 186 for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) { 187 for (j = 0; j < num_op_descs; j++) { 188 if (desc == vfs_op_descs[j]) { 189 /* found it, increase reference count */ 190 vfs_op_desc_refs[j]++; 191 break; 192 } 193 } 194 if (j == num_op_descs) { 195 /* not found, new entry */ 196 MALLOC(newop, struct vnodeop_desc **, 197 (num_op_descs + 1) * sizeof(*newop), 198 M_VNODE, M_WAITOK); 199 if (newop == NULL) 200 panic("vfs_add_vnodeops: no memory for desc"); 201 /* new reference count (for unload) */ 202 MALLOC(newref, int *, 203 (num_op_descs + 1) * sizeof(*newref), 204 M_VNODE, M_WAITOK); 205 if (newref == NULL) 206 panic("vfs_add_vnodeops: no memory for refs"); 207 if (vfs_op_descs) { 208 bcopy(vfs_op_descs, newop, 209 num_op_descs * sizeof(*newop)); 210 FREE(vfs_op_descs, M_VNODE); 211 } 212 if (vfs_op_desc_refs) { 213 bcopy(vfs_op_desc_refs, newref, 214 num_op_descs * sizeof(*newref)); 215 FREE(vfs_op_desc_refs, M_VNODE); 216 } 217 newop[num_op_descs] = desc; 218 newref[num_op_descs] = 1; 219 vfs_op_descs = newop; 220 vfs_op_desc_refs = newref; 221 num_op_descs++; 222 } 223 } 224 vfs_opv_recalc(); 225 } 226 227 /* Remove a vnode type from the vnode description table above. */ 228 void 229 vfs_rm_vnodeops(const void *data) 230 { 231 const struct vnodeopv_desc *opv; 232 const struct vnodeopv_desc **newopv; 233 struct vnodeop_desc **newop; 234 int *newref; 235 vop_t **opv_desc_vector; 236 struct vnodeop_desc *desc; 237 int i, j, k; 238 239 opv = (const struct vnodeopv_desc *)data; 240 /* Lower ref counts on descs in the table and release if zero */ 241 opv_desc_vector = *(opv->opv_desc_vector_p); 242 for (i = 0; (desc = opv->opv_desc_ops[i].opve_op); i++) { 243 for (j = 0; j < num_op_descs; j++) { 244 if (desc == vfs_op_descs[j]) { 245 /* found it, decrease reference count */ 246 vfs_op_desc_refs[j]--; 247 break; 248 } 249 } 250 for (j = 0; j < num_op_descs; j++) { 251 if (vfs_op_desc_refs[j] > 0) 252 continue; 253 if (vfs_op_desc_refs[j] < 0) 254 panic("vfs_remove_vnodeops: negative refcnt"); 255 MALLOC(newop, struct vnodeop_desc **, 256 (num_op_descs - 1) * sizeof(*newop), 257 M_VNODE, M_WAITOK); 258 if (newop == NULL) 259 panic("vfs_remove_vnodeops: no memory for desc"); 260 /* new reference count (for unload) */ 261 MALLOC(newref, int *, 262 (num_op_descs - 1) * sizeof(*newref), 263 M_VNODE, M_WAITOK); 264 if (newref == NULL) 265 panic("vfs_remove_vnodeops: no memory for refs"); 266 for (k = j; k < (num_op_descs - 1); k++) { 267 vfs_op_descs[k] = vfs_op_descs[k + 1]; 268 vfs_op_desc_refs[k] = vfs_op_desc_refs[k + 1]; 269 } 270 bcopy(vfs_op_descs, newop, 271 (num_op_descs - 1) * sizeof(*newop)); 272 bcopy(vfs_op_desc_refs, newref, 273 (num_op_descs - 1) * sizeof(*newref)); 274 FREE(vfs_op_descs, M_VNODE); 275 FREE(vfs_op_desc_refs, M_VNODE); 276 vfs_op_descs = newop; 277 vfs_op_desc_refs = newref; 278 num_op_descs--; 279 } 280 } 281 282 for (i = 0; i < vnodeopv_num; i++) { 283 if (vnodeopv_descs[i] == opv) { 284 for (j = i; j < (vnodeopv_num - 1); j++) 285 vnodeopv_descs[j] = vnodeopv_descs[j + 1]; 286 break; 287 } 288 } 289 if (i == vnodeopv_num) 290 panic("vfs_remove_vnodeops: opv not found"); 291 MALLOC(newopv, const struct vnodeopv_desc **, 292 (vnodeopv_num - 1) * sizeof(*newopv), M_VNODE, M_WAITOK); 293 if (newopv == NULL) 294 panic("vfs_remove_vnodeops: no memory"); 295 bcopy(vnodeopv_descs, newopv, (vnodeopv_num - 1) * sizeof(*newopv)); 296 FREE(vnodeopv_descs, M_VNODE); 297 vnodeopv_descs = newopv; 298 vnodeopv_num--; 299 300 vfs_opv_recalc(); 301 } 302 303 /* 304 * Routines having to do with the management of the vnode table. 305 */ 306 struct vattr va_null; 307 308 /* 309 * Initialize the vnode structures and initialize each file system type. 310 */ 311 /* ARGSUSED*/ 312 static void 313 vfsinit(void *dummy) 314 { 315 316 vattr_null(&va_null); 317 } 318 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL) 319 320 /* Register a new file system type in the global table */ 321 int 322 vfs_register(struct vfsconf *vfc) 323 { 324 struct sysctl_oid *oidp; 325 struct vfsconf *vfsp; 326 327 vfsp = NULL; 328 if (vfsconf) 329 for (vfsp = vfsconf; vfsp->vfc_next; vfsp = vfsp->vfc_next) 330 if (strcmp(vfc->vfc_name, vfsp->vfc_name) == 0) 331 return EEXIST; 332 333 vfc->vfc_typenum = maxvfsconf++; 334 if (vfsp) 335 vfsp->vfc_next = vfc; 336 else 337 vfsconf = vfc; 338 vfc->vfc_next = NULL; 339 340 /* 341 * If this filesystem has a sysctl node under vfs 342 * (i.e. vfs.xxfs), then change the oid number of that node to 343 * match the filesystem's type number. This allows user code 344 * which uses the type number to read sysctl variables defined 345 * by the filesystem to continue working. Since the oids are 346 * in a sorted list, we need to make sure the order is 347 * preserved by re-registering the oid after modifying its 348 * number. 349 */ 350 SLIST_FOREACH(oidp, &sysctl__vfs_children, oid_link) 351 if (strcmp(oidp->oid_name, vfc->vfc_name) == 0) { 352 sysctl_unregister_oid(oidp); 353 oidp->oid_number = vfc->vfc_typenum; 354 sysctl_register_oid(oidp); 355 } 356 357 /* 358 * Call init function for this VFS... 359 */ 360 (*(vfc->vfc_vfsops->vfs_init))(vfc); 361 362 return 0; 363 } 364 365 366 /* Remove registration of a file system type */ 367 int 368 vfs_unregister(struct vfsconf *vfc) 369 { 370 struct vfsconf *vfsp, *prev_vfsp; 371 int error, i, maxtypenum; 372 373 i = vfc->vfc_typenum; 374 375 prev_vfsp = NULL; 376 for (vfsp = vfsconf; vfsp; 377 prev_vfsp = vfsp, vfsp = vfsp->vfc_next) { 378 if (!strcmp(vfc->vfc_name, vfsp->vfc_name)) 379 break; 380 } 381 if (vfsp == NULL) 382 return EINVAL; 383 if (vfsp->vfc_refcount) 384 return EBUSY; 385 if (vfc->vfc_vfsops->vfs_uninit != NULL) { 386 error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp); 387 if (error) 388 return (error); 389 } 390 if (prev_vfsp) 391 prev_vfsp->vfc_next = vfsp->vfc_next; 392 else 393 vfsconf = vfsp->vfc_next; 394 maxtypenum = VFS_GENERIC; 395 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 396 if (maxtypenum < vfsp->vfc_typenum) 397 maxtypenum = vfsp->vfc_typenum; 398 maxvfsconf = maxtypenum + 1; 399 return 0; 400 } 401 402 /* 403 * Standard kernel module handling code for file system modules. 404 * Referenced from VFS_SET(). 405 */ 406 int 407 vfs_modevent(module_t mod, int type, void *data) 408 { 409 struct vfsconf *vfc; 410 int error = 0; 411 412 vfc = (struct vfsconf *)data; 413 414 switch (type) { 415 case MOD_LOAD: 416 if (vfc) 417 error = vfs_register(vfc); 418 break; 419 420 case MOD_UNLOAD: 421 if (vfc) 422 error = vfs_unregister(vfc); 423 break; 424 default: /* including MOD_SHUTDOWN */ 425 break; 426 } 427 return (error); 428 } 429