vfs_default.c revision 33964
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/mount.h> 48#include <sys/poll.h> 49 50/* 51 * VFS operations 52 */ 53 54/* 55 * Complement to all vpp returning ops. 56 * XXX - initially only to get rid of WILLRELE. 57 */ 58/* ARGSUSED */ 59int 60vfs_vrele(mp, vp) 61 struct mount *mp; 62 struct vnode *vp; 63{ 64 vrele(vp); 65 return (0); 66} 67 68/* 69 * vnode operations 70 */ 71 72static int vop_nostrategy __P((struct vop_strategy_args *)); 73 74/* 75 * This vnode table stores what we want to do if the filesystem doesn't 76 * implement a particular VOP. 77 * 78 * If there is no specific entry here, we will return EOPNOTSUPP. 79 * 80 */ 81 82vop_t **default_vnodeop_p; 83static struct vnodeopv_entry_desc default_vnodeop_entries[] = { 84 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 85 { &vop_abortop_desc, (vop_t *) vop_null }, 86 { &vop_advlock_desc, (vop_t *) vop_einval }, 87 { &vop_bwrite_desc, (vop_t *) vop_stdbwrite }, 88 { &vop_close_desc, (vop_t *) vop_null }, 89 { &vop_fsync_desc, (vop_t *) vop_null }, 90 { &vop_ioctl_desc, (vop_t *) vop_enotty }, 91 { &vop_islocked_desc, (vop_t *) vop_noislocked }, 92 { &vop_lease_desc, (vop_t *) vop_null }, 93 { &vop_lock_desc, (vop_t *) vop_nolock }, 94 { &vop_mmap_desc, (vop_t *) vop_einval }, 95 { &vop_open_desc, (vop_t *) vop_null }, 96 { &vop_pathconf_desc, (vop_t *) vop_einval }, 97 { &vop_poll_desc, (vop_t *) vop_nopoll }, 98 { &vop_readlink_desc, (vop_t *) vop_einval }, 99 { &vop_reallocblks_desc, (vop_t *) vop_eopnotsupp }, 100 { &vop_revoke_desc, (vop_t *) vop_revoke }, 101 { &vop_strategy_desc, (vop_t *) vop_nostrategy }, 102 { &vop_unlock_desc, (vop_t *) vop_nounlock }, 103 { NULL, NULL } 104}; 105 106static struct vnodeopv_desc default_vnodeop_opv_desc = 107 { &default_vnodeop_p, default_vnodeop_entries }; 108 109VNODEOP_SET(default_vnodeop_opv_desc); 110 111int 112vop_eopnotsupp(struct vop_generic_args *ap) 113{ 114 /* 115 printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name); 116 */ 117 118 return (EOPNOTSUPP); 119} 120 121int 122vop_ebadf(struct vop_generic_args *ap) 123{ 124 125 return (EBADF); 126} 127 128int 129vop_enotty(struct vop_generic_args *ap) 130{ 131 132 return (ENOTTY); 133} 134 135int 136vop_einval(struct vop_generic_args *ap) 137{ 138 139 return (EINVAL); 140} 141 142int 143vop_null(struct vop_generic_args *ap) 144{ 145 146 return (0); 147} 148 149int 150vop_defaultop(struct vop_generic_args *ap) 151{ 152 153 return (VOCALL(default_vnodeop_p, ap->a_desc->vdesc_offset, ap)); 154} 155 156static int 157vop_nostrategy (struct vop_strategy_args *ap) 158{ 159 printf("No strategy for buffer at %p\n", ap->a_bp); 160 vprint("", ap->a_bp->b_vp); 161 ap->a_bp->b_flags |= B_ERROR; 162 ap->a_bp->b_error = EOPNOTSUPP; 163 biodone(ap->a_bp); 164 return (EOPNOTSUPP); 165} 166 167int 168vop_stdpathconf(ap) 169 struct vop_pathconf_args /* { 170 struct vnode *a_vp; 171 int a_name; 172 int *a_retval; 173 } */ *ap; 174{ 175 176 switch (ap->a_name) { 177 case _PC_LINK_MAX: 178 *ap->a_retval = LINK_MAX; 179 return (0); 180 case _PC_MAX_CANON: 181 *ap->a_retval = MAX_CANON; 182 return (0); 183 case _PC_MAX_INPUT: 184 *ap->a_retval = MAX_INPUT; 185 return (0); 186 case _PC_PIPE_BUF: 187 *ap->a_retval = PIPE_BUF; 188 return (0); 189 case _PC_CHOWN_RESTRICTED: 190 *ap->a_retval = 1; 191 return (0); 192 case _PC_VDISABLE: 193 *ap->a_retval = _POSIX_VDISABLE; 194 return (0); 195 default: 196 return (EINVAL); 197 } 198 /* NOTREACHED */ 199} 200 201/* 202 * Standard lock, unlock and islocked functions. 203 * 204 * These depend on the lock structure being the first element in the 205 * inode, ie: vp->v_data points to the the lock! 206 */ 207int 208vop_stdlock(ap) 209 struct vop_lock_args /* { 210 struct vnode *a_vp; 211 int a_flags; 212 struct proc *a_p; 213 } */ *ap; 214{ 215 struct lock *l; 216 217 if ((l = (struct lock *)ap->a_vp->v_data) == NULL) { 218 if (ap->a_flags & LK_INTERLOCK) 219 simple_unlock(&ap->a_vp->v_interlock); 220 return 0; 221 } 222 223 return (lockmgr(l, ap->a_flags, &ap->a_vp->v_interlock, ap->a_p)); 224} 225 226int 227vop_stdunlock(ap) 228 struct vop_unlock_args /* { 229 struct vnode *a_vp; 230 int a_flags; 231 struct proc *a_p; 232 } */ *ap; 233{ 234 struct lock *l; 235 236 if ((l = (struct lock *)ap->a_vp->v_data) == NULL) { 237 if (ap->a_flags & LK_INTERLOCK) 238 simple_unlock(&ap->a_vp->v_interlock); 239 return 0; 240 } 241 242 return (lockmgr(l, ap->a_flags | LK_RELEASE, &ap->a_vp->v_interlock, 243 ap->a_p)); 244} 245 246int 247vop_stdislocked(ap) 248 struct vop_islocked_args /* { 249 struct vnode *a_vp; 250 } */ *ap; 251{ 252 struct lock *l; 253 254 if ((l = (struct lock *)ap->a_vp->v_data) == NULL) 255 return 0; 256 257 return (lockstatus(l)); 258} 259 260/* 261 * Return true for select/poll. 262 */ 263int 264vop_nopoll(ap) 265 struct vop_poll_args /* { 266 struct vnode *a_vp; 267 int a_events; 268 struct ucred *a_cred; 269 struct proc *a_p; 270 } */ *ap; 271{ 272 /* 273 * Return true for read/write. If the user asked for something 274 * special, return POLLNVAL, so that clients have a way of 275 * determining reliably whether or not the extended 276 * functionality is present without hard-coding knowledge 277 * of specific filesystem implementations. 278 */ 279 if (ap->a_events & ~POLLSTANDARD) 280 return (POLLNVAL); 281 282 return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 283} 284 285/* 286 * Implement poll for local filesystems that support it. 287 */ 288int 289vop_stdpoll(ap) 290 struct vop_poll_args /* { 291 struct vnode *a_vp; 292 int a_events; 293 struct ucred *a_cred; 294 struct proc *a_p; 295 } */ *ap; 296{ 297 if ((ap->a_events & ~POLLSTANDARD) == 0) 298 return (ap->a_events & (POLLRDNORM|POLLWRNORM)); 299 return (vn_pollrecord(ap->a_vp, ap->a_p, ap->a_events)); 300} 301 302int 303vop_stdbwrite(ap) 304 struct vop_bwrite_args *ap; 305{ 306 return (bwrite(ap->a_bp)); 307} 308 309/* 310 * Stubs to use when there is no locking to be done on the underlying object. 311 * A minimal shared lock is necessary to ensure that the underlying object 312 * is not revoked while an operation is in progress. So, an active shared 313 * count is maintained in an auxillary vnode lock structure. 314 */ 315int 316vop_sharedlock(ap) 317 struct vop_lock_args /* { 318 struct vnode *a_vp; 319 int a_flags; 320 struct proc *a_p; 321 } */ *ap; 322{ 323 /* 324 * This code cannot be used until all the non-locking filesystems 325 * (notably NFS) are converted to properly lock and release nodes. 326 * Also, certain vnode operations change the locking state within 327 * the operation (create, mknod, remove, link, rename, mkdir, rmdir, 328 * and symlink). Ideally these operations should not change the 329 * lock state, but should be changed to let the caller of the 330 * function unlock them. Otherwise all intermediate vnode layers 331 * (such as union, umapfs, etc) must catch these functions to do 332 * the necessary locking at their layer. Note that the inactive 333 * and lookup operations also change their lock state, but this 334 * cannot be avoided, so these two operations will always need 335 * to be handled in intermediate layers. 336 */ 337 struct vnode *vp = ap->a_vp; 338 int vnflags, flags = ap->a_flags; 339 340 if (vp->v_vnlock == NULL) { 341 if ((flags & LK_TYPE_MASK) == LK_DRAIN) 342 return (0); 343 MALLOC(vp->v_vnlock, struct lock *, sizeof(struct lock), 344 M_VNODE, M_WAITOK); 345 lockinit(vp->v_vnlock, PVFS, "vnlock", 0, 0); 346 } 347 switch (flags & LK_TYPE_MASK) { 348 case LK_DRAIN: 349 vnflags = LK_DRAIN; 350 break; 351 case LK_EXCLUSIVE: 352#ifdef DEBUG_VFS_LOCKS 353 /* 354 * Normally, we use shared locks here, but that confuses 355 * the locking assertions. 356 */ 357 vnflags = LK_EXCLUSIVE; 358 break; 359#endif 360 case LK_SHARED: 361 vnflags = LK_SHARED; 362 break; 363 case LK_UPGRADE: 364 case LK_EXCLUPGRADE: 365 case LK_DOWNGRADE: 366 return (0); 367 case LK_RELEASE: 368 default: 369 panic("vop_sharedlock: bad operation %d", flags & LK_TYPE_MASK); 370 } 371 if (flags & LK_INTERLOCK) 372 vnflags |= LK_INTERLOCK; 373 return(lockmgr(vp->v_vnlock, vnflags, &vp->v_interlock, ap->a_p)); 374} 375 376/* 377 * Stubs to use when there is no locking to be done on the underlying object. 378 * A minimal shared lock is necessary to ensure that the underlying object 379 * is not revoked while an operation is in progress. So, an active shared 380 * count is maintained in an auxillary vnode lock structure. 381 */ 382int 383vop_nolock(ap) 384 struct vop_lock_args /* { 385 struct vnode *a_vp; 386 int a_flags; 387 struct proc *a_p; 388 } */ *ap; 389{ 390#ifdef notyet 391 /* 392 * This code cannot be used until all the non-locking filesystems 393 * (notably NFS) are converted to properly lock and release nodes. 394 * Also, certain vnode operations change the locking state within 395 * the operation (create, mknod, remove, link, rename, mkdir, rmdir, 396 * and symlink). Ideally these operations should not change the 397 * lock state, but should be changed to let the caller of the 398 * function unlock them. Otherwise all intermediate vnode layers 399 * (such as union, umapfs, etc) must catch these functions to do 400 * the necessary locking at their layer. Note that the inactive 401 * and lookup operations also change their lock state, but this 402 * cannot be avoided, so these two operations will always need 403 * to be handled in intermediate layers. 404 */ 405 struct vnode *vp = ap->a_vp; 406 int vnflags, flags = ap->a_flags; 407 408 if (vp->v_vnlock == NULL) { 409 if ((flags & LK_TYPE_MASK) == LK_DRAIN) 410 return (0); 411 MALLOC(vp->v_vnlock, struct lock *, sizeof(struct lock), 412 M_VNODE, M_WAITOK); 413 lockinit(vp->v_vnlock, PVFS, "vnlock", 0, 0); 414 } 415 switch (flags & LK_TYPE_MASK) { 416 case LK_DRAIN: 417 vnflags = LK_DRAIN; 418 break; 419 case LK_EXCLUSIVE: 420 case LK_SHARED: 421 vnflags = LK_SHARED; 422 break; 423 case LK_UPGRADE: 424 case LK_EXCLUPGRADE: 425 case LK_DOWNGRADE: 426 return (0); 427 case LK_RELEASE: 428 default: 429 panic("vop_nolock: bad operation %d", flags & LK_TYPE_MASK); 430 } 431 if (flags & LK_INTERLOCK) 432 vnflags |= LK_INTERLOCK; 433 return(lockmgr(vp->v_vnlock, vnflags, &vp->v_interlock, ap->a_p)); 434#else /* for now */ 435 /* 436 * Since we are not using the lock manager, we must clear 437 * the interlock here. 438 */ 439 if (ap->a_flags & LK_INTERLOCK) 440 simple_unlock(&ap->a_vp->v_interlock); 441 return (0); 442#endif 443} 444 445/* 446 * Do the inverse of vop_nolock, handling the interlock in a compatible way. 447 */ 448int 449vop_nounlock(ap) 450 struct vop_unlock_args /* { 451 struct vnode *a_vp; 452 int a_flags; 453 struct proc *a_p; 454 } */ *ap; 455{ 456 struct vnode *vp = ap->a_vp; 457 458 if (vp->v_vnlock == NULL) { 459 if (ap->a_flags & LK_INTERLOCK) 460 simple_unlock(&ap->a_vp->v_interlock); 461 return (0); 462 } 463 return (lockmgr(vp->v_vnlock, LK_RELEASE | ap->a_flags, 464 &ap->a_vp->v_interlock, ap->a_p)); 465} 466 467/* 468 * Return whether or not the node is in use. 469 */ 470int 471vop_noislocked(ap) 472 struct vop_islocked_args /* { 473 struct vnode *a_vp; 474 } */ *ap; 475{ 476 struct vnode *vp = ap->a_vp; 477 478 if (vp->v_vnlock == NULL) 479 return (0); 480 return (lockstatus(vp->v_vnlock)); 481} 482 483