vfs_default.c revision 31561
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 */ 39 40#include <sys/param.h> 41#include <sys/systm.h> 42#include <sys/kernel.h> 43#include <sys/lock.h> 44#include <sys/malloc.h> 45#include <sys/unistd.h> 46#include <sys/vnode.h> 47#include <sys/poll.h> 48 49static int vop_nostrategy __P((struct vop_strategy_args *)); 50 51/* 52 * This vnode table stores what we want to do if the filesystem doesn't 53 * implement a particular VOP. 54 * 55 * If there is no specific entry here, we will return EOPNOTSUPP. 56 * 57 */ 58 59vop_t **default_vnodeop_p; 60static struct vnodeopv_entry_desc default_vnodeop_entries[] = { 61 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 62 { &vop_abortop_desc, (vop_t *) vop_null }, 63 { &vop_advlock_desc, (vop_t *) vop_einval }, 64 { &vop_bwrite_desc, (vop_t *) vop_stdbwrite }, 65 { &vop_close_desc, (vop_t *) vop_null }, 66 { &vop_fsync_desc, (vop_t *) vop_null }, 67 { &vop_ioctl_desc, (vop_t *) vop_enotty }, 68 { &vop_islocked_desc, (vop_t *) vop_noislocked }, 69 { &vop_lease_desc, (vop_t *) vop_null }, 70 { &vop_lock_desc, (vop_t *) vop_nolock }, 71 { &vop_mmap_desc, (vop_t *) vop_einval }, 72 { &vop_open_desc, (vop_t *) vop_null }, 73 { &vop_pathconf_desc, (vop_t *) vop_einval }, 74 { &vop_poll_desc, (vop_t *) vop_nopoll }, 75 { &vop_readlink_desc, (vop_t *) vop_einval }, 76 { &vop_reallocblks_desc, (vop_t *) vop_eopnotsupp }, 77 { &vop_revoke_desc, (vop_t *) vop_revoke }, 78 { &vop_strategy_desc, (vop_t *) vop_nostrategy }, 79 { &vop_unlock_desc, (vop_t *) vop_nounlock }, 80 { NULL, NULL } 81}; 82 83static struct vnodeopv_desc default_vnodeop_opv_desc = 84 { &default_vnodeop_p, default_vnodeop_entries }; 85 86VNODEOP_SET(default_vnodeop_opv_desc); 87 88int 89vop_eopnotsupp(struct vop_generic_args *ap) 90{ 91 /* 92 printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name); 93 */ 94 95 return (EOPNOTSUPP); 96} 97 98int 99vop_ebadf(struct vop_generic_args *ap) 100{ 101 102 return (EBADF); 103} 104 105int 106vop_enotty(struct vop_generic_args *ap) 107{ 108 109 return (ENOTTY); 110} 111 112int 113vop_einval(struct vop_generic_args *ap) 114{ 115 116 return (EINVAL); 117} 118 119int 120vop_null(struct vop_generic_args *ap) 121{ 122 123 return (0); 124} 125 126int 127vop_defaultop(struct vop_generic_args *ap) 128{ 129 130 return (VOCALL(default_vnodeop_p, ap->a_desc->vdesc_offset, ap)); 131} 132 133static int 134vop_nostrategy (struct vop_strategy_args *ap) 135{ 136 printf("No strategy for buffer at %p\n", ap->a_bp); 137 vprint("", ap->a_bp->b_vp); 138 ap->a_bp->b_flags |= B_ERROR; 139 ap->a_bp->b_error = EOPNOTSUPP; 140 biodone(ap->a_bp); 141 return (EOPNOTSUPP); 142} 143 144int 145vop_stdpathconf(ap) 146 struct vop_pathconf_args /* { 147 struct vnode *a_vp; 148 int a_name; 149 int *a_retval; 150 } */ *ap; 151{ 152 153 switch (ap->a_name) { 154 case _PC_LINK_MAX: 155 *ap->a_retval = LINK_MAX; 156 return (0); 157 case _PC_MAX_CANON: 158 *ap->a_retval = MAX_CANON; 159 return (0); 160 case _PC_MAX_INPUT: 161 *ap->a_retval = MAX_INPUT; 162 return (0); 163 case _PC_PIPE_BUF: 164 *ap->a_retval = PIPE_BUF; 165 return (0); 166 case _PC_CHOWN_RESTRICTED: 167 *ap->a_retval = 1; 168 return (0); 169 case _PC_VDISABLE: 170 *ap->a_retval = _POSIX_VDISABLE; 171 return (0); 172 default: 173 return (EINVAL); 174 } 175 /* NOTREACHED */ 176} 177 178/* 179 * Standard lock, unlock and islocked functions. 180 * 181 * These depend on the lock structure being the first element in the 182 * inode, ie: vp->v_data points to the the lock! 183 */ 184int 185vop_stdlock(ap) 186 struct vop_lock_args /* { 187 struct vnode *a_vp; 188 int a_flags; 189 struct proc *a_p; 190 } */ *ap; 191{ 192 struct lock *l = (struct lock*)ap->a_vp->v_data; 193 194 return (lockmgr(l, ap->a_flags, &ap->a_vp->v_interlock, ap->a_p)); 195} 196 197int 198vop_stdunlock(ap) 199 struct vop_unlock_args /* { 200 struct vnode *a_vp; 201 int a_flags; 202 struct proc *a_p; 203 } */ *ap; 204{ 205 struct lock *l = (struct lock*)ap->a_vp->v_data; 206 207 return (lockmgr(l, ap->a_flags | LK_RELEASE, &ap->a_vp->v_interlock, 208 ap->a_p)); 209} 210 211int 212vop_stdislocked(ap) 213 struct vop_islocked_args /* { 214 struct vnode *a_vp; 215 } */ *ap; 216{ 217 struct lock *l = (struct lock*)ap->a_vp->v_data; 218 219 return (lockstatus(l)); 220} 221 222/* 223 * Return true for select/poll. 224 */ 225int 226vop_nopoll(ap) 227 struct vop_poll_args /* { 228 struct vnode *a_vp; 229 int a_events; 230 struct ucred *a_cred; 231 struct proc *a_p; 232 } */ *ap; 233{ 234 235 /* 236 * Just return what we were asked for. 237 */ 238 return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 239} 240 241int 242vop_stdbwrite(ap) 243 struct vop_bwrite_args *ap; 244{ 245 return (bwrite(ap->a_bp)); 246} 247 248/* 249 * Stubs to use when there is no locking to be done on the underlying object. 250 * A minimal shared lock is necessary to ensure that the underlying object 251 * is not revoked while an operation is in progress. So, an active shared 252 * count is maintained in an auxillary vnode lock structure. 253 */ 254int 255vop_sharedlock(ap) 256 struct vop_lock_args /* { 257 struct vnode *a_vp; 258 int a_flags; 259 struct proc *a_p; 260 } */ *ap; 261{ 262 /* 263 * This code cannot be used until all the non-locking filesystems 264 * (notably NFS) are converted to properly lock and release nodes. 265 * Also, certain vnode operations change the locking state within 266 * the operation (create, mknod, remove, link, rename, mkdir, rmdir, 267 * and symlink). Ideally these operations should not change the 268 * lock state, but should be changed to let the caller of the 269 * function unlock them. Otherwise all intermediate vnode layers 270 * (such as union, umapfs, etc) must catch these functions to do 271 * the necessary locking at their layer. Note that the inactive 272 * and lookup operations also change their lock state, but this 273 * cannot be avoided, so these two operations will always need 274 * to be handled in intermediate layers. 275 */ 276 struct vnode *vp = ap->a_vp; 277 int vnflags, flags = ap->a_flags; 278 279 if (vp->v_vnlock == NULL) { 280 if ((flags & LK_TYPE_MASK) == LK_DRAIN) 281 return (0); 282 MALLOC(vp->v_vnlock, struct lock *, sizeof(struct lock), 283 M_VNODE, M_WAITOK); 284 lockinit(vp->v_vnlock, PVFS, "vnlock", 0, 0); 285 } 286 switch (flags & LK_TYPE_MASK) { 287 case LK_DRAIN: 288 vnflags = LK_DRAIN; 289 break; 290 case LK_EXCLUSIVE: 291#ifdef DEBUG_VFS_LOCKS 292 /* 293 * Normally, we use shared locks here, but that confuses 294 * the locking assertions. 295 */ 296 vnflags = LK_EXCLUSIVE; 297 break; 298#endif 299 case LK_SHARED: 300 vnflags = LK_SHARED; 301 break; 302 case LK_UPGRADE: 303 case LK_EXCLUPGRADE: 304 case LK_DOWNGRADE: 305 return (0); 306 case LK_RELEASE: 307 default: 308 panic("vop_sharedlock: bad operation %d", flags & LK_TYPE_MASK); 309 } 310 if (flags & LK_INTERLOCK) 311 vnflags |= LK_INTERLOCK; 312 return(lockmgr(vp->v_vnlock, vnflags, &vp->v_interlock, ap->a_p)); 313} 314 315/* 316 * Stubs to use when there is no locking to be done on the underlying object. 317 * A minimal shared lock is necessary to ensure that the underlying object 318 * is not revoked while an operation is in progress. So, an active shared 319 * count is maintained in an auxillary vnode lock structure. 320 */ 321int 322vop_nolock(ap) 323 struct vop_lock_args /* { 324 struct vnode *a_vp; 325 int a_flags; 326 struct proc *a_p; 327 } */ *ap; 328{ 329#ifdef notyet 330 /* 331 * This code cannot be used until all the non-locking filesystems 332 * (notably NFS) are converted to properly lock and release nodes. 333 * Also, certain vnode operations change the locking state within 334 * the operation (create, mknod, remove, link, rename, mkdir, rmdir, 335 * and symlink). Ideally these operations should not change the 336 * lock state, but should be changed to let the caller of the 337 * function unlock them. Otherwise all intermediate vnode layers 338 * (such as union, umapfs, etc) must catch these functions to do 339 * the necessary locking at their layer. Note that the inactive 340 * and lookup operations also change their lock state, but this 341 * cannot be avoided, so these two operations will always need 342 * to be handled in intermediate layers. 343 */ 344 struct vnode *vp = ap->a_vp; 345 int vnflags, flags = ap->a_flags; 346 347 if (vp->v_vnlock == NULL) { 348 if ((flags & LK_TYPE_MASK) == LK_DRAIN) 349 return (0); 350 MALLOC(vp->v_vnlock, struct lock *, sizeof(struct lock), 351 M_VNODE, M_WAITOK); 352 lockinit(vp->v_vnlock, PVFS, "vnlock", 0, 0); 353 } 354 switch (flags & LK_TYPE_MASK) { 355 case LK_DRAIN: 356 vnflags = LK_DRAIN; 357 break; 358 case LK_EXCLUSIVE: 359 case LK_SHARED: 360 vnflags = LK_SHARED; 361 break; 362 case LK_UPGRADE: 363 case LK_EXCLUPGRADE: 364 case LK_DOWNGRADE: 365 return (0); 366 case LK_RELEASE: 367 default: 368 panic("vop_nolock: bad operation %d", flags & LK_TYPE_MASK); 369 } 370 if (flags & LK_INTERLOCK) 371 vnflags |= LK_INTERLOCK; 372 return(lockmgr(vp->v_vnlock, vnflags, &vp->v_interlock, ap->a_p)); 373#else /* for now */ 374 /* 375 * Since we are not using the lock manager, we must clear 376 * the interlock here. 377 */ 378 if (ap->a_flags & LK_INTERLOCK) 379 simple_unlock(&ap->a_vp->v_interlock); 380 return (0); 381#endif 382} 383 384/* 385 * Do the inverse of vop_nolock, handling the interlock in a compatible way. 386 */ 387int 388vop_nounlock(ap) 389 struct vop_unlock_args /* { 390 struct vnode *a_vp; 391 int a_flags; 392 struct proc *a_p; 393 } */ *ap; 394{ 395 struct vnode *vp = ap->a_vp; 396 397 if (vp->v_vnlock == NULL) { 398 if (ap->a_flags & LK_INTERLOCK) 399 simple_unlock(&ap->a_vp->v_interlock); 400 return (0); 401 } 402 return (lockmgr(vp->v_vnlock, LK_RELEASE | ap->a_flags, 403 &ap->a_vp->v_interlock, ap->a_p)); 404} 405 406/* 407 * Return whether or not the node is in use. 408 */ 409int 410vop_noislocked(ap) 411 struct vop_islocked_args /* { 412 struct vnode *a_vp; 413 } */ *ap; 414{ 415 struct vnode *vp = ap->a_vp; 416 417 if (vp->v_vnlock == NULL) 418 return (0); 419 return (lockstatus(vp->v_vnlock)); 420} 421 422