1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 35 */ 36 37 /* 38 * External virtual filesystem routines 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_ddb.h" 45 #include "opt_mac.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/conf.h> 52 #include <sys/event.h> 53 #include <sys/eventhandler.h> 54 #include <sys/extattr.h> 55 #include <sys/fcntl.h> 56 #include <sys/kdb.h> 57 #include <sys/kernel.h> 58 #include <sys/kthread.h> 59 #include <sys/mac.h> 60 #include <sys/malloc.h> 61 #include <sys/mount.h> 62 #include <sys/namei.h> 63 #include <sys/reboot.h> 64 #include <sys/sleepqueue.h> 65 #include <sys/stat.h> 66 #include <sys/sysctl.h> 67 #include <sys/syslog.h> 68 #include <sys/vmmeter.h> 69 #include <sys/vnode.h> 70 71 #include <vm/vm.h> 72 #include <vm/vm_object.h> 73 #include <vm/vm_extern.h> 74 #include <vm/pmap.h> 75 #include <vm/vm_map.h> 76 #include <vm/vm_page.h> 77 #include <vm/vm_kern.h> 78 #include <vm/uma.h> 79 80 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 81 82 static void addalias(struct vnode *vp, struct cdev *nvp_rdev); 83 static void delmntque(struct vnode *vp); 84 static void insmntque(struct vnode *vp, struct mount *mp); 85 static void vclean(struct vnode *vp, int flags, struct thread *td); 86 static void vlruvp(struct vnode *vp); 87 static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, 88 int slpflag, int slptimeo, int *errorp); 89 static void syncer_shutdown(void *arg, int howto); 90 static int vtryrecycle(struct vnode *vp); 91 static void vx_lock(struct vnode *vp); 92 static void vx_unlock(struct vnode *vp); 93 static void vgonechrl(struct vnode *vp, struct thread *td); 94 95 96 /* 97 * Number of vnodes in existence. Increased whenever getnewvnode() 98 * allocates a new vnode, never decreased. 99 */ 100 static unsigned long numvnodes; 101 102 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 103 104 /* 105 * Conversion tables for conversion from vnode types to inode formats 106 * and back. 107 */ 108 enum vtype iftovt_tab[16] = { 109 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 110 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 111 }; 112 int vttoif_tab[9] = { 113 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 114 S_IFSOCK, S_IFIFO, S_IFMT, 115 }; 116 117 /* 118 * List of vnodes that are ready for recycling. 119 */ 120 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 121 122 /* 123 * Minimum number of free vnodes. If there are fewer than this free vnodes, 124 * getnewvnode() will return a newly allocated vnode. 125 */ 126 static u_long wantfreevnodes = 25; 127 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 128 /* Number of vnodes in the free list. */ 129 static u_long freevnodes; 130 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 131 132 /* 133 * Various variables used for debugging the new implementation of 134 * reassignbuf(). 135 * XXX these are probably of (very) limited utility now. 136 */ 137 static int reassignbufcalls; 138 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 139 static int nameileafonly; 140 SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 141 142 /* 143 * Cache for the mount type id assigned to NFS. This is used for 144 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 145 */ 146 int nfs_mount_type = -1; 147 148 /* To keep more than one thread at a time from running vfs_getnewfsid */ 149 static struct mtx mntid_mtx; 150 151 /* 152 * Lock for any access to the following: 153 * vnode_free_list 154 * numvnodes 155 * freevnodes 156 */ 157 static struct mtx vnode_free_list_mtx; 158 159 /* 160 * For any iteration/modification of dev->si_hlist (linked through 161 * v_specnext) 162 */ 163 static struct mtx spechash_mtx; 164 165 /* Publicly exported FS */ 166 struct nfs_public nfs_pub; 167 168 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 169 static uma_zone_t vnode_zone; 170 static uma_zone_t vnodepoll_zone; 171 172 /* Set to 1 to print out reclaim of active vnodes */ 173 int prtactive; 174 175 /* 176 * The workitem queue. 177 * 178 * It is useful to delay writes of file data and filesystem metadata 179 * for tens of seconds so that quickly created and deleted files need 180 * not waste disk bandwidth being created and removed. To realize this, 181 * we append vnodes to a "workitem" queue. When running with a soft 182 * updates implementation, most pending metadata dependencies should 183 * not wait for more than a few seconds. Thus, mounted on block devices 184 * are delayed only about a half the time that file data is delayed. 185 * Similarly, directory updates are more critical, so are only delayed 186 * about a third the time that file data is delayed. Thus, there are 187 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 188 * one each second (driven off the filesystem syncer process). The 189 * syncer_delayno variable indicates the next queue that is to be processed. 190 * Items that need to be processed soon are placed in this queue: 191 * 192 * syncer_workitem_pending[syncer_delayno] 193 * 194 * A delay of fifteen seconds is done by placing the request fifteen 195 * entries later in the queue: 196 * 197 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 198 * 199 */ 200 static int syncer_delayno; 201 static long syncer_mask; 202 LIST_HEAD(synclist, vnode); 203 static struct synclist *syncer_workitem_pending; 204 /* 205 * The sync_mtx protects: 206 * vp->v_synclist 207 * sync_vnode_count 208 * syncer_delayno 209 * syncer_state 210 * syncer_workitem_pending 211 * syncer_worklist_len 212 * rushjob 213 */ 214 static struct mtx sync_mtx; 215 216 #define SYNCER_MAXDELAY 32 217 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 218 static int syncdelay = 30; /* max time to delay syncing data */ 219 static int filedelay = 30; /* time to delay syncing files */ 220 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 221 static int dirdelay = 29; /* time to delay syncing directories */ 222 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 223 static int metadelay = 28; /* time to delay syncing metadata */ 224 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 225 static int rushjob; /* number of slots to run ASAP */ 226 static int stat_rush_requests; /* number of times I/O speeded up */ 227 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 228 229 /* 230 * When shutting down the syncer, run it at four times normal speed. 231 */ 232 #define SYNCER_SHUTDOWN_SPEEDUP 4 233 static int sync_vnode_count; 234 static int syncer_worklist_len; 235 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 236 syncer_state; 237 238 /* 239 * Number of vnodes we want to exist at any one time. This is mostly used 240 * to size hash tables in vnode-related code. It is normally not used in 241 * getnewvnode(), as wantfreevnodes is normally nonzero.) 242 * 243 * XXX desiredvnodes is historical cruft and should not exist. 244 */ 245 int desiredvnodes; 246 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 247 &desiredvnodes, 0, "Maximum number of vnodes"); 248 static int minvnodes; 249 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 250 &minvnodes, 0, "Minimum number of vnodes"); 251 static int vnlru_nowhere; 252 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 253 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 254 255 /* Hook for calling soft updates. */ 256 int (*softdep_process_worklist_hook)(struct mount *); 257 258 /* 259 * Initialize the vnode management data structures. 260 */ 261 #ifndef MAXVNODES_MAX 262 #define MAXVNODES_MAX 100000 263 #endif 264 static void 265 vntblinit(void *dummy __unused) 266 { 267 268 /* 269 * Desiredvnodes is a function of the physical memory size and 270 * the kernel's heap size. Specifically, desiredvnodes scales 271 * in proportion to the physical memory size until two fifths 272 * of the kernel's heap size is consumed by vnodes and vm 273 * objects. 274 */ 275 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / 276 (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); 277 if (desiredvnodes > MAXVNODES_MAX) { 278 if (bootverbose) 279 printf("Reducing kern.maxvnodes %d -> %d\n", 280 desiredvnodes, MAXVNODES_MAX); 281 desiredvnodes = MAXVNODES_MAX; 282 } 283 minvnodes = desiredvnodes / 4; 284 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 285 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 286 mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); 287 TAILQ_INIT(&vnode_free_list); 288 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 289 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 290 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 291 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 292 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 293 /* 294 * Initialize the filesystem syncer. 295 */ 296 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 297 &syncer_mask); 298 syncer_maxdelay = syncer_mask + 1; 299 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 300 } 301 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 302 303 304 /* 305 * Mark a mount point as busy. Used to synchronize access and to delay 306 * unmounting. Interlock is not released on failure. 307 */ 308 int 309 vfs_busy(mp, flags, interlkp, td) 310 struct mount *mp; 311 int flags; 312 struct mtx *interlkp; 313 struct thread *td; 314 { 315 int lkflags; 316 317 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 318 if (flags & LK_NOWAIT) 319 return (ENOENT); 320 mp->mnt_kern_flag |= MNTK_MWAIT; 321 /* 322 * Since all busy locks are shared except the exclusive 323 * lock granted when unmounting, the only place that a 324 * wakeup needs to be done is at the release of the 325 * exclusive lock at the end of dounmount. 326 */ 327 msleep(mp, interlkp, PVFS, "vfs_busy", 0); 328 return (ENOENT); 329 } 330 lkflags = LK_SHARED | LK_NOPAUSE; 331 if (interlkp) 332 lkflags |= LK_INTERLOCK; 333 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 334 panic("vfs_busy: unexpected lock failure"); 335 return (0); 336 } 337 338 /* 339 * Free a busy filesystem. 340 */ 341 void 342 vfs_unbusy(mp, td) 343 struct mount *mp; 344 struct thread *td; 345 { 346 347 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 348 } 349 350 /* 351 * Lookup a mount point by filesystem identifier. 352 */ 353 struct mount * 354 vfs_getvfs(fsid) 355 fsid_t *fsid; 356 { 357 register struct mount *mp; 358 359 mtx_lock(&mountlist_mtx); 360 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 361 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 362 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 363 mtx_unlock(&mountlist_mtx); 364 return (mp); 365 } 366 } 367 mtx_unlock(&mountlist_mtx); 368 return ((struct mount *) 0); 369 } 370 371 /* 372 * Check if a user can access priveledged mount options. 373 */ 374 int 375 vfs_suser(struct mount *mp, struct thread *td) 376 { 377 int error; 378 379 if ((mp->mnt_flag & MNT_USER) == 0 || 380 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 381 if ((error = suser(td)) != 0) 382 return (error); 383 } 384 return (0); 385 } 386 387 /* 388 * Get a new unique fsid. Try to make its val[0] unique, since this value 389 * will be used to create fake device numbers for stat(). Also try (but 390 * not so hard) make its val[0] unique mod 2^16, since some emulators only 391 * support 16-bit device numbers. We end up with unique val[0]'s for the 392 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 393 * 394 * Keep in mind that several mounts may be running in parallel. Starting 395 * the search one past where the previous search terminated is both a 396 * micro-optimization and a defense against returning the same fsid to 397 * different mounts. 398 */ 399 void 400 vfs_getnewfsid(mp) 401 struct mount *mp; 402 { 403 static u_int16_t mntid_base; 404 fsid_t tfsid; 405 int mtype; 406 407 mtx_lock(&mntid_mtx); 408 mtype = mp->mnt_vfc->vfc_typenum; 409 tfsid.val[1] = mtype; 410 mtype = (mtype & 0xFF) << 24; 411 for (;;) { 412 tfsid.val[0] = makedev(255, 413 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 414 mntid_base++; 415 if (vfs_getvfs(&tfsid) == NULL) 416 break; 417 } 418 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 419 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 420 mtx_unlock(&mntid_mtx); 421 } 422 423 /* 424 * Knob to control the precision of file timestamps: 425 * 426 * 0 = seconds only; nanoseconds zeroed. 427 * 1 = seconds and nanoseconds, accurate within 1/HZ. 428 * 2 = seconds and nanoseconds, truncated to microseconds. 429 * >=3 = seconds and nanoseconds, maximum precision. 430 */ 431 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 432 433 static int timestamp_precision = TSP_SEC; 434 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 435 ×tamp_precision, 0, ""); 436 437 /* 438 * Get a current timestamp. 439 */ 440 void 441 vfs_timestamp(tsp) 442 struct timespec *tsp; 443 { 444 struct timeval tv; 445 446 switch (timestamp_precision) { 447 case TSP_SEC: 448 tsp->tv_sec = time_second; 449 tsp->tv_nsec = 0; 450 break; 451 case TSP_HZ: 452 getnanotime(tsp); 453 break; 454 case TSP_USEC: 455 microtime(&tv); 456 TIMEVAL_TO_TIMESPEC(&tv, tsp); 457 break; 458 case TSP_NSEC: 459 default: 460 nanotime(tsp); 461 break; 462 } 463 } 464 465 /* 466 * Set vnode attributes to VNOVAL 467 */ 468 void 469 vattr_null(vap) 470 register struct vattr *vap; 471 { 472 473 vap->va_type = VNON; 474 vap->va_size = VNOVAL; 475 vap->va_bytes = VNOVAL; 476 vap->va_mode = VNOVAL; 477 vap->va_nlink = VNOVAL; 478 vap->va_uid = VNOVAL; 479 vap->va_gid = VNOVAL; 480 vap->va_fsid = VNOVAL; 481 vap->va_fileid = VNOVAL; 482 vap->va_blocksize = VNOVAL; 483 vap->va_rdev = VNOVAL; 484 vap->va_atime.tv_sec = VNOVAL; 485 vap->va_atime.tv_nsec = VNOVAL; 486 vap->va_mtime.tv_sec = VNOVAL; 487 vap->va_mtime.tv_nsec = VNOVAL; 488 vap->va_ctime.tv_sec = VNOVAL; 489 vap->va_ctime.tv_nsec = VNOVAL; 490 vap->va_birthtime.tv_sec = VNOVAL; 491 vap->va_birthtime.tv_nsec = VNOVAL; 492 vap->va_flags = VNOVAL; 493 vap->va_gen = VNOVAL; 494 vap->va_vaflags = 0; 495 } 496 497 /* 498 * This routine is called when we have too many vnodes. It attempts 499 * to free <count> vnodes and will potentially free vnodes that still 500 * have VM backing store (VM backing store is typically the cause 501 * of a vnode blowout so we want to do this). Therefore, this operation 502 * is not considered cheap. 503 * 504 * A number of conditions may prevent a vnode from being reclaimed. 505 * the buffer cache may have references on the vnode, a directory 506 * vnode may still have references due to the namei cache representing 507 * underlying files, or the vnode may be in active use. It is not 508 * desireable to reuse such vnodes. These conditions may cause the 509 * number of vnodes to reach some minimum value regardless of what 510 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 511 */ 512 static int 513 vlrureclaim(struct mount *mp) 514 { 515 struct vnode *vp; 516 int done; 517 int trigger; 518 int usevnodes; 519 int count; 520 521 /* 522 * Calculate the trigger point, don't allow user 523 * screwups to blow us up. This prevents us from 524 * recycling vnodes with lots of resident pages. We 525 * aren't trying to free memory, we are trying to 526 * free vnodes. 527 */ 528 usevnodes = desiredvnodes; 529 if (usevnodes <= 0) 530 usevnodes = 1; 531 trigger = cnt.v_page_count * 2 / usevnodes; 532 533 done = 0; 534 MNT_ILOCK(mp); 535 count = mp->mnt_nvnodelistsize / 10 + 1; 536 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 537 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 538 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 539 540 if (vp->v_type != VNON && 541 vp->v_type != VBAD && 542 VI_TRYLOCK(vp)) { 543 if (VMIGHTFREE(vp) && /* critical path opt */ 544 (vp->v_object == NULL || 545 vp->v_object->resident_page_count < trigger)) { 546 MNT_IUNLOCK(mp); 547 vgonel(vp, curthread); 548 done++; 549 MNT_ILOCK(mp); 550 } else 551 VI_UNLOCK(vp); 552 } 553 --count; 554 } 555 MNT_IUNLOCK(mp); 556 return done; 557 } 558 559 /* 560 * Attempt to recycle vnodes in a context that is always safe to block. 561 * Calling vlrurecycle() from the bowels of filesystem code has some 562 * interesting deadlock problems. 563 */ 564 static struct proc *vnlruproc; 565 static int vnlruproc_sig; 566 567 static void 568 vnlru_proc(void) 569 { 570 struct mount *mp, *nmp; 571 int done; 572 struct proc *p = vnlruproc; 573 struct thread *td = FIRST_THREAD_IN_PROC(p); 574 575 mtx_lock(&Giant); 576 577 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 578 SHUTDOWN_PRI_FIRST); 579 580 for (;;) { 581 kthread_suspend_check(p); 582 mtx_lock(&vnode_free_list_mtx); 583 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 584 mtx_unlock(&vnode_free_list_mtx); 585 vnlruproc_sig = 0; 586 wakeup(&vnlruproc_sig); 587 tsleep(vnlruproc, PVFS, "vlruwt", hz); 588 continue; 589 } 590 mtx_unlock(&vnode_free_list_mtx); 591 done = 0; 592 mtx_lock(&mountlist_mtx); 593 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 594 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 595 nmp = TAILQ_NEXT(mp, mnt_list); 596 continue; 597 } 598 done += vlrureclaim(mp); 599 mtx_lock(&mountlist_mtx); 600 nmp = TAILQ_NEXT(mp, mnt_list); 601 vfs_unbusy(mp, td); 602 } 603 mtx_unlock(&mountlist_mtx); 604 if (done == 0) { 605 #if 0 606 /* These messages are temporary debugging aids */ 607 if (vnlru_nowhere < 5) 608 printf("vnlru process getting nowhere..\n"); 609 else if (vnlru_nowhere == 5) 610 printf("vnlru process messages stopped.\n"); 611 #endif 612 vnlru_nowhere++; 613 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 614 } 615 } 616 } 617 618 static struct kproc_desc vnlru_kp = { 619 "vnlru", 620 vnlru_proc, 621 &vnlruproc 622 }; 623 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 624 625 626 /* 627 * Routines having to do with the management of the vnode table. 628 */ 629 630 /* 631 * Check to see if a free vnode can be recycled. If it can, 632 * recycle it and return it with the vnode interlock held. 633 */ 634 static int 635 vtryrecycle(struct vnode *vp) 636 { 637 struct thread *td = curthread; 638 vm_object_t object; 639 struct mount *vnmp; 640 int error; 641 642 /* Don't recycle if we can't get the interlock */ 643 if (!VI_TRYLOCK(vp)) 644 return (EWOULDBLOCK); 645 /* 646 * This vnode may found and locked via some other list, if so we 647 * can't recycle it yet. 648 */ 649 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 650 return (EWOULDBLOCK); 651 /* 652 * Don't recycle if its filesystem is being suspended. 653 */ 654 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 655 VOP_UNLOCK(vp, 0, td); 656 return (EBUSY); 657 } 658 659 /* 660 * Don't recycle if we still have cached pages. 661 */ 662 if (VOP_GETVOBJECT(vp, &object) == 0) { 663 VM_OBJECT_LOCK(object); 664 if (object->resident_page_count || 665 object->ref_count) { 666 VM_OBJECT_UNLOCK(object); 667 error = EBUSY; 668 goto done; 669 } 670 VM_OBJECT_UNLOCK(object); 671 } 672 if (LIST_FIRST(&vp->v_cache_src)) { 673 /* 674 * note: nameileafonly sysctl is temporary, 675 * for debugging only, and will eventually be 676 * removed. 677 */ 678 if (nameileafonly > 0) { 679 /* 680 * Do not reuse namei-cached directory 681 * vnodes that have cached 682 * subdirectories. 683 */ 684 if (cache_leaf_test(vp) < 0) { 685 error = EISDIR; 686 goto done; 687 } 688 } else if (nameileafonly < 0 || 689 vmiodirenable == 0) { 690 /* 691 * Do not reuse namei-cached directory 692 * vnodes if nameileafonly is -1 or 693 * if VMIO backing for directories is 694 * turned off (otherwise we reuse them 695 * too quickly). 696 */ 697 error = EBUSY; 698 goto done; 699 } 700 } 701 /* 702 * If we got this far, we need to acquire the interlock and see if 703 * anyone picked up this vnode from another list. If not, we will 704 * mark it with XLOCK via vgonel() so that anyone who does find it 705 * will skip over it. 706 */ 707 VI_LOCK(vp); 708 if (VSHOULDBUSY(vp) && (vp->v_iflag & VI_XLOCK) == 0) { 709 VI_UNLOCK(vp); 710 error = EBUSY; 711 goto done; 712 } 713 mtx_lock(&vnode_free_list_mtx); 714 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 715 vp->v_iflag &= ~VI_FREE; 716 mtx_unlock(&vnode_free_list_mtx); 717 vp->v_iflag |= VI_DOOMED; 718 if (vp->v_type != VBAD) { 719 VOP_UNLOCK(vp, 0, td); 720 vgonel(vp, td); 721 VI_LOCK(vp); 722 } else 723 VOP_UNLOCK(vp, 0, td); 724 vn_finished_write(vnmp); 725 return (0); 726 done: 727 VOP_UNLOCK(vp, 0, td); 728 vn_finished_write(vnmp); 729 return (error); 730 } 731 732 /* 733 * Return the next vnode from the free list. 734 */ 735 int 736 getnewvnode(tag, mp, vops, vpp) 737 const char *tag; 738 struct mount *mp; 739 vop_t **vops; 740 struct vnode **vpp; 741 { 742 struct vnode *vp = NULL; 743 struct vpollinfo *pollinfo = NULL; 744 745 mtx_lock(&vnode_free_list_mtx); 746 747 /* 748 * Try to reuse vnodes if we hit the max. This situation only 749 * occurs in certain large-memory (2G+) situations. We cannot 750 * attempt to directly reclaim vnodes due to nasty recursion 751 * problems. 752 */ 753 while (numvnodes - freevnodes > desiredvnodes) { 754 if (vnlruproc_sig == 0) { 755 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 756 wakeup(vnlruproc); 757 } 758 mtx_unlock(&vnode_free_list_mtx); 759 tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); 760 mtx_lock(&vnode_free_list_mtx); 761 } 762 763 /* 764 * Attempt to reuse a vnode already on the free list, allocating 765 * a new vnode if we can't find one or if we have not reached a 766 * good minimum for good LRU performance. 767 */ 768 769 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 770 int error; 771 int count; 772 773 for (count = 0; count < freevnodes; count++) { 774 vp = TAILQ_FIRST(&vnode_free_list); 775 776 KASSERT(vp->v_usecount == 0 && 777 (vp->v_iflag & VI_DOINGINACT) == 0, 778 ("getnewvnode: free vnode isn't")); 779 780 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 781 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 782 mtx_unlock(&vnode_free_list_mtx); 783 error = vtryrecycle(vp); 784 mtx_lock(&vnode_free_list_mtx); 785 if (error == 0) 786 break; 787 vp = NULL; 788 } 789 } 790 if (vp) { 791 freevnodes--; 792 mtx_unlock(&vnode_free_list_mtx); 793 794 #ifdef INVARIANTS 795 { 796 if (vp->v_data) 797 panic("cleaned vnode isn't"); 798 if (vp->v_numoutput) 799 panic("Clean vnode has pending I/O's"); 800 if (vp->v_writecount != 0) 801 panic("Non-zero write count"); 802 } 803 #endif 804 if ((pollinfo = vp->v_pollinfo) != NULL) { 805 /* 806 * To avoid lock order reversals, the call to 807 * uma_zfree() must be delayed until the vnode 808 * interlock is released. 809 */ 810 vp->v_pollinfo = NULL; 811 } 812 #ifdef MAC 813 mac_destroy_vnode(vp); 814 #endif 815 vp->v_iflag = 0; 816 vp->v_vflag = 0; 817 vp->v_lastw = 0; 818 vp->v_lasta = 0; 819 vp->v_cstart = 0; 820 vp->v_clen = 0; 821 vp->v_socket = 0; 822 lockdestroy(vp->v_vnlock); 823 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 824 KASSERT(vp->v_cleanbufcnt == 0, ("cleanbufcnt not 0")); 825 KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); 826 KASSERT(vp->v_dirtybufcnt == 0, ("dirtybufcnt not 0")); 827 KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); 828 } else { 829 numvnodes++; 830 mtx_unlock(&vnode_free_list_mtx); 831 832 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 833 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 834 VI_LOCK(vp); 835 vp->v_dd = vp; 836 vp->v_vnlock = &vp->v_lock; 837 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 838 cache_purge(vp); /* Sets up v_id. */ 839 LIST_INIT(&vp->v_cache_src); 840 TAILQ_INIT(&vp->v_cache_dst); 841 } 842 843 TAILQ_INIT(&vp->v_cleanblkhd); 844 TAILQ_INIT(&vp->v_dirtyblkhd); 845 vp->v_type = VNON; 846 vp->v_tag = tag; 847 vp->v_op = vops; 848 *vpp = vp; 849 vp->v_usecount = 1; 850 vp->v_data = 0; 851 vp->v_cachedid = -1; 852 VI_UNLOCK(vp); 853 if (pollinfo != NULL) { 854 knlist_destroy(&pollinfo->vpi_selinfo.si_note); 855 mtx_destroy(&pollinfo->vpi_lock); 856 uma_zfree(vnodepoll_zone, pollinfo); 857 } 858 #ifdef MAC 859 mac_init_vnode(vp); 860 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 861 mac_associate_vnode_singlelabel(mp, vp); 862 #endif 863 delmntque(vp); 864 if (mp != NULL) { 865 insmntque(vp, mp); 866 vp->v_bsize = mp->mnt_stat.f_iosize; 867 } 868 869 return (0); 870 } 871 872 /* 873 * Delete from old mount point vnode list, if on one. 874 */ 875 static void 876 delmntque(struct vnode *vp) 877 { 878 struct mount *mp; 879 880 if (vp->v_mount == NULL) 881 return; 882 mp = vp->v_mount; 883 MNT_ILOCK(mp); 884 vp->v_mount = NULL; 885 KASSERT(mp->mnt_nvnodelistsize > 0, 886 ("bad mount point vnode list size")); 887 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 888 mp->mnt_nvnodelistsize--; 889 MNT_IUNLOCK(mp); 890 } 891 892 /* 893 * Insert into list of vnodes for the new mount point, if available. 894 */ 895 static void 896 insmntque(struct vnode *vp, struct mount *mp) 897 { 898 899 vp->v_mount = mp; 900 KASSERT(mp != NULL, ("Don't call insmntque(foo, NULL)")); 901 MNT_ILOCK(vp->v_mount); 902 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 903 mp->mnt_nvnodelistsize++; 904 MNT_IUNLOCK(vp->v_mount); 905 } 906 907 /* 908 * Update outstanding I/O count and do wakeup if requested. 909 */ 910 void 911 vwakeup(bp) 912 register struct buf *bp; 913 { 914 register struct vnode *vp; 915 916 bp->b_flags &= ~B_WRITEINPROG; 917 if ((vp = bp->b_vp)) { 918 VI_LOCK(vp); 919 vp->v_numoutput--; 920 if (vp->v_numoutput < 0) 921 panic("vwakeup: neg numoutput"); 922 if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) { 923 vp->v_iflag &= ~VI_BWAIT; 924 wakeup(&vp->v_numoutput); 925 } 926 VI_UNLOCK(vp); 927 } 928 } 929 930 /* 931 * Flush out and invalidate all buffers associated with a vnode. 932 * Called with the underlying object locked. 933 */ 934 int 935 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 936 struct vnode *vp; 937 int flags; 938 struct ucred *cred; 939 struct thread *td; 940 int slpflag, slptimeo; 941 { 942 struct buf *blist; 943 int error; 944 vm_object_t object; 945 946 GIANT_REQUIRED; 947 948 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 949 950 VI_LOCK(vp); 951 if (flags & V_SAVE) { 952 while (vp->v_numoutput) { 953 vp->v_iflag |= VI_BWAIT; 954 error = msleep(&vp->v_numoutput, VI_MTX(vp), 955 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 956 if (error) { 957 VI_UNLOCK(vp); 958 return (error); 959 } 960 } 961 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 962 VI_UNLOCK(vp); 963 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 964 return (error); 965 /* 966 * XXX We could save a lock/unlock if this was only 967 * enabled under INVARIANTS 968 */ 969 VI_LOCK(vp); 970 if (vp->v_numoutput > 0 || 971 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 972 panic("vinvalbuf: dirty bufs"); 973 } 974 } 975 /* 976 * If you alter this loop please notice that interlock is dropped and 977 * reacquired in flushbuflist. Special care is needed to ensure that 978 * no race conditions occur from this. 979 */ 980 for (error = 0;;) { 981 if ((blist = TAILQ_FIRST(&vp->v_cleanblkhd)) != 0 && 982 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 983 if (error) 984 break; 985 continue; 986 } 987 if ((blist = TAILQ_FIRST(&vp->v_dirtyblkhd)) != 0 && 988 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 989 if (error) 990 break; 991 continue; 992 } 993 break; 994 } 995 if (error) { 996 VI_UNLOCK(vp); 997 return (error); 998 } 999 1000 /* 1001 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1002 * have write I/O in-progress but if there is a VM object then the 1003 * VM object can also have read-I/O in-progress. 1004 */ 1005 do { 1006 while (vp->v_numoutput > 0) { 1007 vp->v_iflag |= VI_BWAIT; 1008 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0); 1009 } 1010 VI_UNLOCK(vp); 1011 if (VOP_GETVOBJECT(vp, &object) == 0) { 1012 VM_OBJECT_LOCK(object); 1013 vm_object_pip_wait(object, "vnvlbx"); 1014 VM_OBJECT_UNLOCK(object); 1015 } 1016 VI_LOCK(vp); 1017 } while (vp->v_numoutput > 0); 1018 VI_UNLOCK(vp); 1019 1020 /* 1021 * Destroy the copy in the VM cache, too. 1022 */ 1023 if (VOP_GETVOBJECT(vp, &object) == 0) { 1024 VM_OBJECT_LOCK(object); 1025 vm_object_page_remove(object, 0, 0, 1026 (flags & V_SAVE) ? TRUE : FALSE); 1027 VM_OBJECT_UNLOCK(object); 1028 } 1029 1030 #ifdef INVARIANTS 1031 VI_LOCK(vp); 1032 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1033 (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || 1034 !TAILQ_EMPTY(&vp->v_cleanblkhd))) 1035 panic("vinvalbuf: flush failed"); 1036 VI_UNLOCK(vp); 1037 #endif 1038 return (0); 1039 } 1040 1041 /* 1042 * Flush out buffers on the specified list. 1043 * 1044 */ 1045 static int 1046 flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) 1047 struct buf *blist; 1048 int flags; 1049 struct vnode *vp; 1050 int slpflag, slptimeo; 1051 int *errorp; 1052 { 1053 struct buf *bp, *nbp; 1054 int found, error; 1055 1056 ASSERT_VI_LOCKED(vp, "flushbuflist"); 1057 1058 for (found = 0, bp = blist; bp; bp = nbp) { 1059 nbp = TAILQ_NEXT(bp, b_vnbufs); 1060 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1061 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1062 continue; 1063 } 1064 found += 1; 1065 error = BUF_TIMELOCK(bp, 1066 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), 1067 "flushbuf", slpflag, slptimeo); 1068 if (error) { 1069 if (error != ENOLCK) 1070 *errorp = error; 1071 goto done; 1072 } 1073 /* 1074 * XXX Since there are no node locks for NFS, I 1075 * believe there is a slight chance that a delayed 1076 * write will occur while sleeping just above, so 1077 * check for it. Note that vfs_bio_awrite expects 1078 * buffers to reside on a queue, while bwrite and 1079 * brelse do not. 1080 */ 1081 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1082 (flags & V_SAVE)) { 1083 1084 if (bp->b_vp == vp) { 1085 if (bp->b_flags & B_CLUSTEROK) { 1086 vfs_bio_awrite(bp); 1087 } else { 1088 bremfree(bp); 1089 bp->b_flags |= B_ASYNC; 1090 bwrite(bp); 1091 } 1092 } else { 1093 bremfree(bp); 1094 (void) bwrite(bp); 1095 } 1096 goto done; 1097 } 1098 bremfree(bp); 1099 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1100 bp->b_flags &= ~B_ASYNC; 1101 brelse(bp); 1102 VI_LOCK(vp); 1103 } 1104 return (found); 1105 done: 1106 VI_LOCK(vp); 1107 return (found); 1108 } 1109 1110 /* 1111 * Truncate a file's buffer and pages to a specified length. This 1112 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1113 * sync activity. 1114 */ 1115 int 1116 vtruncbuf(vp, cred, td, length, blksize) 1117 register struct vnode *vp; 1118 struct ucred *cred; 1119 struct thread *td; 1120 off_t length; 1121 int blksize; 1122 { 1123 register struct buf *bp; 1124 struct buf *nbp; 1125 int anyfreed; 1126 int trunclbn; 1127 1128 /* 1129 * Round up to the *next* lbn. 1130 */ 1131 trunclbn = (length + blksize - 1) / blksize; 1132 1133 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1134 restart: 1135 VI_LOCK(vp); 1136 anyfreed = 1; 1137 for (;anyfreed;) { 1138 anyfreed = 0; 1139 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 1140 nbp = TAILQ_NEXT(bp, b_vnbufs); 1141 if (bp->b_lblkno >= trunclbn) { 1142 if (BUF_LOCK(bp, 1143 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1144 VI_MTX(vp)) == ENOLCK) 1145 goto restart; 1146 1147 bremfree(bp); 1148 bp->b_flags |= (B_INVAL | B_RELBUF); 1149 bp->b_flags &= ~B_ASYNC; 1150 brelse(bp); 1151 anyfreed = 1; 1152 1153 if (nbp && 1154 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1155 (nbp->b_vp != vp) || 1156 (nbp->b_flags & B_DELWRI))) { 1157 goto restart; 1158 } 1159 VI_LOCK(vp); 1160 } 1161 } 1162 1163 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1164 nbp = TAILQ_NEXT(bp, b_vnbufs); 1165 if (bp->b_lblkno >= trunclbn) { 1166 if (BUF_LOCK(bp, 1167 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1168 VI_MTX(vp)) == ENOLCK) 1169 goto restart; 1170 bremfree(bp); 1171 bp->b_flags |= (B_INVAL | B_RELBUF); 1172 bp->b_flags &= ~B_ASYNC; 1173 brelse(bp); 1174 anyfreed = 1; 1175 if (nbp && 1176 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1177 (nbp->b_vp != vp) || 1178 (nbp->b_flags & B_DELWRI) == 0)) { 1179 goto restart; 1180 } 1181 VI_LOCK(vp); 1182 } 1183 } 1184 } 1185 1186 if (length > 0) { 1187 restartsync: 1188 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1189 nbp = TAILQ_NEXT(bp, b_vnbufs); 1190 if (bp->b_lblkno > 0) 1191 continue; 1192 /* 1193 * Since we hold the vnode lock this should only 1194 * fail if we're racing with the buf daemon. 1195 */ 1196 if (BUF_LOCK(bp, 1197 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1198 VI_MTX(vp)) == ENOLCK) { 1199 goto restart; 1200 } 1201 KASSERT((bp->b_flags & B_DELWRI), 1202 ("buf(%p) on dirty queue without DELWRI", bp)); 1203 1204 bremfree(bp); 1205 bawrite(bp); 1206 VI_LOCK(vp); 1207 goto restartsync; 1208 } 1209 } 1210 1211 while (vp->v_numoutput > 0) { 1212 vp->v_iflag |= VI_BWAIT; 1213 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0); 1214 } 1215 VI_UNLOCK(vp); 1216 vnode_pager_setsize(vp, length); 1217 1218 return (0); 1219 } 1220 1221 /* 1222 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1223 * a vnode. 1224 * 1225 * NOTE: We have to deal with the special case of a background bitmap 1226 * buffer, a situation where two buffers will have the same logical 1227 * block offset. We want (1) only the foreground buffer to be accessed 1228 * in a lookup and (2) must differentiate between the foreground and 1229 * background buffer in the splay tree algorithm because the splay 1230 * tree cannot normally handle multiple entities with the same 'index'. 1231 * We accomplish this by adding differentiating flags to the splay tree's 1232 * numerical domain. 1233 */ 1234 static 1235 struct buf * 1236 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1237 { 1238 struct buf dummy; 1239 struct buf *lefttreemax, *righttreemin, *y; 1240 1241 if (root == NULL) 1242 return (NULL); 1243 lefttreemax = righttreemin = &dummy; 1244 for (;;) { 1245 if (lblkno < root->b_lblkno || 1246 (lblkno == root->b_lblkno && 1247 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1248 if ((y = root->b_left) == NULL) 1249 break; 1250 if (lblkno < y->b_lblkno) { 1251 /* Rotate right. */ 1252 root->b_left = y->b_right; 1253 y->b_right = root; 1254 root = y; 1255 if ((y = root->b_left) == NULL) 1256 break; 1257 } 1258 /* Link into the new root's right tree. */ 1259 righttreemin->b_left = root; 1260 righttreemin = root; 1261 } else if (lblkno > root->b_lblkno || 1262 (lblkno == root->b_lblkno && 1263 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1264 if ((y = root->b_right) == NULL) 1265 break; 1266 if (lblkno > y->b_lblkno) { 1267 /* Rotate left. */ 1268 root->b_right = y->b_left; 1269 y->b_left = root; 1270 root = y; 1271 if ((y = root->b_right) == NULL) 1272 break; 1273 } 1274 /* Link into the new root's left tree. */ 1275 lefttreemax->b_right = root; 1276 lefttreemax = root; 1277 } else { 1278 break; 1279 } 1280 root = y; 1281 } 1282 /* Assemble the new root. */ 1283 lefttreemax->b_right = root->b_left; 1284 righttreemin->b_left = root->b_right; 1285 root->b_left = dummy.b_right; 1286 root->b_right = dummy.b_left; 1287 return (root); 1288 } 1289 1290 static 1291 void 1292 buf_vlist_remove(struct buf *bp) 1293 { 1294 struct vnode *vp = bp->b_vp; 1295 struct buf *root; 1296 1297 ASSERT_VI_LOCKED(vp, "buf_vlist_remove"); 1298 if (bp->b_xflags & BX_VNDIRTY) { 1299 if (bp != vp->v_dirtyblkroot) { 1300 root = buf_splay(bp->b_lblkno, bp->b_xflags, 1301 vp->v_dirtyblkroot); 1302 KASSERT(root == bp, 1303 ("splay lookup failed during dirty remove")); 1304 } 1305 if (bp->b_left == NULL) { 1306 root = bp->b_right; 1307 } else { 1308 root = buf_splay(bp->b_lblkno, bp->b_xflags, 1309 bp->b_left); 1310 root->b_right = bp->b_right; 1311 } 1312 vp->v_dirtyblkroot = root; 1313 TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); 1314 vp->v_dirtybufcnt--; 1315 } else { 1316 /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ 1317 if (bp != vp->v_cleanblkroot) { 1318 root = buf_splay(bp->b_lblkno, bp->b_xflags, 1319 vp->v_cleanblkroot); 1320 KASSERT(root == bp, 1321 ("splay lookup failed during clean remove")); 1322 } 1323 if (bp->b_left == NULL) { 1324 root = bp->b_right; 1325 } else { 1326 root = buf_splay(bp->b_lblkno, bp->b_xflags, 1327 bp->b_left); 1328 root->b_right = bp->b_right; 1329 } 1330 vp->v_cleanblkroot = root; 1331 TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); 1332 vp->v_cleanbufcnt--; 1333 } 1334 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1335 } 1336 1337 /* 1338 * Add the buffer to the sorted clean or dirty block list using a 1339 * splay tree algorithm. 1340 * 1341 * NOTE: xflags is passed as a constant, optimizing this inline function! 1342 */ 1343 static 1344 void 1345 buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) 1346 { 1347 struct buf *root; 1348 1349 ASSERT_VI_LOCKED(vp, "buf_vlist_add"); 1350 bp->b_xflags |= xflags; 1351 if (xflags & BX_VNDIRTY) { 1352 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1353 if (root == NULL) { 1354 bp->b_left = NULL; 1355 bp->b_right = NULL; 1356 TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); 1357 } else if (bp->b_lblkno < root->b_lblkno || 1358 (bp->b_lblkno == root->b_lblkno && 1359 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1360 bp->b_left = root->b_left; 1361 bp->b_right = root; 1362 root->b_left = NULL; 1363 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1364 } else { 1365 bp->b_right = root->b_right; 1366 bp->b_left = root; 1367 root->b_right = NULL; 1368 TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, 1369 root, bp, b_vnbufs); 1370 } 1371 vp->v_dirtybufcnt++; 1372 vp->v_dirtyblkroot = bp; 1373 } else { 1374 /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ 1375 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1376 if (root == NULL) { 1377 bp->b_left = NULL; 1378 bp->b_right = NULL; 1379 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1380 } else if (bp->b_lblkno < root->b_lblkno || 1381 (bp->b_lblkno == root->b_lblkno && 1382 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1383 bp->b_left = root->b_left; 1384 bp->b_right = root; 1385 root->b_left = NULL; 1386 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1387 } else { 1388 bp->b_right = root->b_right; 1389 bp->b_left = root; 1390 root->b_right = NULL; 1391 TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, 1392 root, bp, b_vnbufs); 1393 } 1394 vp->v_cleanbufcnt++; 1395 vp->v_cleanblkroot = bp; 1396 } 1397 } 1398 1399 /* 1400 * Lookup a buffer using the splay tree. Note that we specifically avoid 1401 * shadow buffers used in background bitmap writes. 1402 * 1403 * This code isn't quite efficient as it could be because we are maintaining 1404 * two sorted lists and do not know which list the block resides in. 1405 * 1406 * During a "make buildworld" the desired buffer is found at one of 1407 * the roots more than 60% of the time. Thus, checking both roots 1408 * before performing either splay eliminates unnecessary splays on the 1409 * first tree splayed. 1410 */ 1411 struct buf * 1412 gbincore(struct vnode *vp, daddr_t lblkno) 1413 { 1414 struct buf *bp; 1415 1416 GIANT_REQUIRED; 1417 1418 ASSERT_VI_LOCKED(vp, "gbincore"); 1419 if ((bp = vp->v_cleanblkroot) != NULL && 1420 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1421 return (bp); 1422 if ((bp = vp->v_dirtyblkroot) != NULL && 1423 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1424 return (bp); 1425 if ((bp = vp->v_cleanblkroot) != NULL) { 1426 vp->v_cleanblkroot = bp = buf_splay(lblkno, 0, bp); 1427 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1428 return (bp); 1429 } 1430 if ((bp = vp->v_dirtyblkroot) != NULL) { 1431 vp->v_dirtyblkroot = bp = buf_splay(lblkno, 0, bp); 1432 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1433 return (bp); 1434 } 1435 return (NULL); 1436 } 1437 1438 /* 1439 * Associate a buffer with a vnode. 1440 */ 1441 void 1442 bgetvp(vp, bp) 1443 register struct vnode *vp; 1444 register struct buf *bp; 1445 { 1446 1447 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1448 1449 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1450 ("bgetvp: bp already attached! %p", bp)); 1451 1452 ASSERT_VI_LOCKED(vp, "bgetvp"); 1453 vholdl(vp); 1454 bp->b_vp = vp; 1455 bp->b_dev = vn_todev(vp); 1456 /* 1457 * Insert onto list for new vnode. 1458 */ 1459 buf_vlist_add(bp, vp, BX_VNCLEAN); 1460 } 1461 1462 /* 1463 * Disassociate a buffer from a vnode. 1464 */ 1465 void 1466 brelvp(bp) 1467 register struct buf *bp; 1468 { 1469 struct vnode *vp; 1470 1471 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1472 1473 /* 1474 * Delete from old vnode list, if on one. 1475 */ 1476 vp = bp->b_vp; 1477 VI_LOCK(vp); 1478 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1479 buf_vlist_remove(bp); 1480 if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1481 vp->v_iflag &= ~VI_ONWORKLST; 1482 mtx_lock(&sync_mtx); 1483 LIST_REMOVE(vp, v_synclist); 1484 syncer_worklist_len--; 1485 mtx_unlock(&sync_mtx); 1486 } 1487 vdropl(vp); 1488 bp->b_vp = (struct vnode *) 0; 1489 if (bp->b_object) 1490 bp->b_object = NULL; 1491 VI_UNLOCK(vp); 1492 } 1493 1494 /* 1495 * Add an item to the syncer work queue. 1496 */ 1497 static void 1498 vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1499 { 1500 int slot; 1501 1502 ASSERT_VI_LOCKED(vp, "vn_syncer_add_to_worklist"); 1503 1504 mtx_lock(&sync_mtx); 1505 if (vp->v_iflag & VI_ONWORKLST) 1506 LIST_REMOVE(vp, v_synclist); 1507 else { 1508 vp->v_iflag |= VI_ONWORKLST; 1509 syncer_worklist_len++; 1510 } 1511 1512 if (delay > syncer_maxdelay - 2) 1513 delay = syncer_maxdelay - 2; 1514 slot = (syncer_delayno + delay) & syncer_mask; 1515 1516 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1517 mtx_unlock(&sync_mtx); 1518 } 1519 1520 static int 1521 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1522 { 1523 int error, len; 1524 1525 mtx_lock(&sync_mtx); 1526 len = syncer_worklist_len - sync_vnode_count; 1527 mtx_unlock(&sync_mtx); 1528 error = SYSCTL_OUT(req, &len, sizeof(len)); 1529 return (error); 1530 } 1531 1532 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1533 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1534 1535 struct proc *updateproc; 1536 static void sched_sync(void); 1537 static struct kproc_desc up_kp = { 1538 "syncer", 1539 sched_sync, 1540 &updateproc 1541 }; 1542 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1543 1544 /* 1545 * System filesystem synchronizer daemon. 1546 */ 1547 static void 1548 sched_sync(void) 1549 { 1550 struct synclist *next; 1551 struct synclist *slp; 1552 struct vnode *vp; 1553 struct mount *mp; 1554 long starttime; 1555 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); 1556 static int dummychan; 1557 int last_work_seen; 1558 int net_worklist_len; 1559 int syncer_final_iter; 1560 int first_printf; 1561 1562 mtx_lock(&Giant); 1563 last_work_seen = 0; 1564 syncer_final_iter = 0; 1565 first_printf = 1; 1566 syncer_state = SYNCER_RUNNING; 1567 starttime = time_second; 1568 1569 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 1570 SHUTDOWN_PRI_LAST); 1571 1572 for (;;) { 1573 mtx_lock(&sync_mtx); 1574 if (syncer_state == SYNCER_FINAL_DELAY && 1575 syncer_final_iter == 0) { 1576 mtx_unlock(&sync_mtx); 1577 kthread_suspend_check(td->td_proc); 1578 mtx_lock(&sync_mtx); 1579 } 1580 net_worklist_len = syncer_worklist_len - sync_vnode_count; 1581 if (syncer_state != SYNCER_RUNNING && 1582 starttime != time_second) { 1583 if (first_printf) { 1584 printf("\nSyncing disks, vnodes remaining..."); 1585 first_printf = 0; 1586 } 1587 printf("%d ", net_worklist_len); 1588 } 1589 starttime = time_second; 1590 1591 /* 1592 * Push files whose dirty time has expired. Be careful 1593 * of interrupt race on slp queue. 1594 * 1595 * Skip over empty worklist slots when shutting down. 1596 */ 1597 do { 1598 slp = &syncer_workitem_pending[syncer_delayno]; 1599 syncer_delayno += 1; 1600 if (syncer_delayno == syncer_maxdelay) 1601 syncer_delayno = 0; 1602 next = &syncer_workitem_pending[syncer_delayno]; 1603 /* 1604 * If the worklist has wrapped since the 1605 * it was emptied of all but syncer vnodes, 1606 * switch to the FINAL_DELAY state and run 1607 * for one more second. 1608 */ 1609 if (syncer_state == SYNCER_SHUTTING_DOWN && 1610 net_worklist_len == 0 && 1611 last_work_seen == syncer_delayno) { 1612 syncer_state = SYNCER_FINAL_DELAY; 1613 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 1614 } 1615 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 1616 syncer_worklist_len > 0); 1617 1618 /* 1619 * Keep track of the last time there was anything 1620 * on the worklist other than syncer vnodes. 1621 * Return to the SHUTTING_DOWN state if any 1622 * new work appears. 1623 */ 1624 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 1625 last_work_seen = syncer_delayno; 1626 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 1627 syncer_state = SYNCER_SHUTTING_DOWN; 1628 while ((vp = LIST_FIRST(slp)) != NULL) { 1629 if (VOP_ISLOCKED(vp, NULL) != 0 || 1630 vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1631 LIST_REMOVE(vp, v_synclist); 1632 LIST_INSERT_HEAD(next, vp, v_synclist); 1633 continue; 1634 } 1635 if (VI_TRYLOCK(vp) == 0) { 1636 LIST_REMOVE(vp, v_synclist); 1637 LIST_INSERT_HEAD(next, vp, v_synclist); 1638 vn_finished_write(mp); 1639 continue; 1640 } 1641 /* 1642 * We use vhold in case the vnode does not 1643 * successfully sync. vhold prevents the vnode from 1644 * going away when we unlock the sync_mtx so that 1645 * we can acquire the vnode interlock. 1646 */ 1647 vholdl(vp); 1648 mtx_unlock(&sync_mtx); 1649 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td); 1650 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1651 VOP_UNLOCK(vp, 0, td); 1652 vn_finished_write(mp); 1653 VI_LOCK(vp); 1654 if ((vp->v_iflag & VI_ONWORKLST) != 0) { 1655 /* 1656 * Put us back on the worklist. The worklist 1657 * routine will remove us from our current 1658 * position and then add us back in at a later 1659 * position. 1660 */ 1661 vn_syncer_add_to_worklist(vp, syncdelay); 1662 } 1663 vdropl(vp); 1664 VI_UNLOCK(vp); 1665 mtx_lock(&sync_mtx); 1666 } 1667 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 1668 syncer_final_iter--; 1669 mtx_unlock(&sync_mtx); 1670 1671 /* 1672 * Do soft update processing. 1673 */ 1674 if (softdep_process_worklist_hook != NULL) 1675 (*softdep_process_worklist_hook)(NULL); 1676 1677 /* 1678 * The variable rushjob allows the kernel to speed up the 1679 * processing of the filesystem syncer process. A rushjob 1680 * value of N tells the filesystem syncer to process the next 1681 * N seconds worth of work on its queue ASAP. Currently rushjob 1682 * is used by the soft update code to speed up the filesystem 1683 * syncer process when the incore state is getting so far 1684 * ahead of the disk that the kernel memory pool is being 1685 * threatened with exhaustion. 1686 */ 1687 mtx_lock(&sync_mtx); 1688 if (rushjob > 0) { 1689 rushjob -= 1; 1690 mtx_unlock(&sync_mtx); 1691 continue; 1692 } 1693 mtx_unlock(&sync_mtx); 1694 /* 1695 * Just sleep for a short period if time between 1696 * iterations when shutting down to allow some I/O 1697 * to happen. 1698 * 1699 * If it has taken us less than a second to process the 1700 * current work, then wait. Otherwise start right over 1701 * again. We can still lose time if any single round 1702 * takes more than two seconds, but it does not really 1703 * matter as we are just trying to generally pace the 1704 * filesystem activity. 1705 */ 1706 if (syncer_state != SYNCER_RUNNING) 1707 tsleep(&dummychan, PPAUSE, "syncfnl", 1708 hz / SYNCER_SHUTDOWN_SPEEDUP); 1709 else if (time_second == starttime) 1710 tsleep(&lbolt, PPAUSE, "syncer", 0); 1711 } 1712 } 1713 1714 /* 1715 * Request the syncer daemon to speed up its work. 1716 * We never push it to speed up more than half of its 1717 * normal turn time, otherwise it could take over the cpu. 1718 */ 1719 int 1720 speedup_syncer() 1721 { 1722 struct thread *td; 1723 int ret = 0; 1724 1725 td = FIRST_THREAD_IN_PROC(updateproc); 1726 sleepq_remove(td, &lbolt); 1727 mtx_lock(&sync_mtx); 1728 if (rushjob < syncdelay / 2) { 1729 rushjob += 1; 1730 stat_rush_requests += 1; 1731 ret = 1; 1732 } 1733 mtx_unlock(&sync_mtx); 1734 return (ret); 1735 } 1736 1737 /* 1738 * Tell the syncer to speed up its work and run though its work 1739 * list several times, then tell it to shut down. 1740 */ 1741 static void 1742 syncer_shutdown(void *arg, int howto) 1743 { 1744 struct thread *td; 1745 1746 if (howto & RB_NOSYNC) 1747 return; 1748 td = FIRST_THREAD_IN_PROC(updateproc); 1749 sleepq_remove(td, &lbolt); 1750 mtx_lock(&sync_mtx); 1751 syncer_state = SYNCER_SHUTTING_DOWN; 1752 rushjob = 0; 1753 mtx_unlock(&sync_mtx); 1754 kproc_shutdown(arg, howto); 1755 } 1756 1757 /* 1758 * Associate a p-buffer with a vnode. 1759 * 1760 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1761 * with the buffer. i.e. the bp has not been linked into the vnode or 1762 * ref-counted. 1763 */ 1764 void 1765 pbgetvp(vp, bp) 1766 register struct vnode *vp; 1767 register struct buf *bp; 1768 { 1769 1770 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1771 1772 bp->b_vp = vp; 1773 bp->b_object = vp->v_object; 1774 bp->b_flags |= B_PAGING; 1775 bp->b_dev = vn_todev(vp); 1776 } 1777 1778 /* 1779 * Disassociate a p-buffer from a vnode. 1780 */ 1781 void 1782 pbrelvp(bp) 1783 register struct buf *bp; 1784 { 1785 1786 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1787 1788 /* XXX REMOVE ME */ 1789 VI_LOCK(bp->b_vp); 1790 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1791 panic( 1792 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1793 bp, 1794 (int)bp->b_flags 1795 ); 1796 } 1797 VI_UNLOCK(bp->b_vp); 1798 bp->b_vp = (struct vnode *) 0; 1799 bp->b_object = NULL; 1800 bp->b_flags &= ~B_PAGING; 1801 } 1802 1803 /* 1804 * Reassign a buffer from one vnode to another. 1805 * Used to assign file specific control information 1806 * (indirect blocks) to the vnode to which they belong. 1807 */ 1808 void 1809 reassignbuf(struct buf *bp) 1810 { 1811 struct vnode *vp; 1812 int delay; 1813 1814 vp = bp->b_vp; 1815 ++reassignbufcalls; 1816 1817 /* 1818 * B_PAGING flagged buffers cannot be reassigned because their vp 1819 * is not fully linked in. 1820 */ 1821 if (bp->b_flags & B_PAGING) 1822 panic("cannot reassign paging buffer"); 1823 1824 /* 1825 * Delete from old vnode list, if on one. 1826 */ 1827 VI_LOCK(vp); 1828 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1829 buf_vlist_remove(bp); 1830 /* 1831 * If dirty, put on list of dirty buffers; otherwise insert onto list 1832 * of clean buffers. 1833 */ 1834 if (bp->b_flags & B_DELWRI) { 1835 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 1836 switch (vp->v_type) { 1837 case VDIR: 1838 delay = dirdelay; 1839 break; 1840 case VCHR: 1841 delay = metadelay; 1842 break; 1843 default: 1844 delay = filedelay; 1845 } 1846 vn_syncer_add_to_worklist(vp, delay); 1847 } 1848 buf_vlist_add(bp, vp, BX_VNDIRTY); 1849 } else { 1850 buf_vlist_add(bp, vp, BX_VNCLEAN); 1851 1852 if ((vp->v_iflag & VI_ONWORKLST) && 1853 TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1854 mtx_lock(&sync_mtx); 1855 LIST_REMOVE(vp, v_synclist); 1856 syncer_worklist_len--; 1857 mtx_unlock(&sync_mtx); 1858 vp->v_iflag &= ~VI_ONWORKLST; 1859 } 1860 } 1861 VI_UNLOCK(vp); 1862 } 1863 1864 /* 1865 * Create a vnode for a device. 1866 * Used for mounting the root filesystem. 1867 */ 1868 int 1869 bdevvp(dev, vpp) 1870 struct cdev *dev; 1871 struct vnode **vpp; 1872 { 1873 register struct vnode *vp; 1874 struct vnode *nvp; 1875 int error; 1876 1877 if (dev == NULL) { 1878 *vpp = NULLVP; 1879 return (ENXIO); 1880 } 1881 if (vfinddev(dev, vpp)) 1882 return (0); 1883 1884 error = getnewvnode("none", (struct mount *)0, spec_vnodeop_p, &nvp); 1885 if (error) { 1886 *vpp = NULLVP; 1887 return (error); 1888 } 1889 vp = nvp; 1890 vp->v_type = VCHR; 1891 vp->v_bsize = DEV_BSIZE; 1892 addalias(vp, dev); 1893 *vpp = vp; 1894 return (0); 1895 } 1896 1897 static void 1898 v_incr_usecount(struct vnode *vp, int delta) 1899 { 1900 1901 vp->v_usecount += delta; 1902 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1903 mtx_lock(&spechash_mtx); 1904 vp->v_rdev->si_usecount += delta; 1905 mtx_unlock(&spechash_mtx); 1906 } 1907 } 1908 1909 /* 1910 * Add vnode to the alias list hung off the struct cdev *. 1911 * 1912 * The reason for this gunk is that multiple vnodes can reference 1913 * the same physical device, so checking vp->v_usecount to see 1914 * how many users there are is inadequate; the v_usecount for 1915 * the vnodes need to be accumulated. vcount() does that. 1916 */ 1917 struct vnode * 1918 addaliasu(nvp, nvp_rdev) 1919 struct vnode *nvp; 1920 dev_t nvp_rdev; 1921 { 1922 struct vnode *ovp; 1923 vop_t **ops; 1924 struct cdev *dev; 1925 1926 if (nvp->v_type == VBLK) 1927 return (nvp); 1928 if (nvp->v_type != VCHR) 1929 panic("addaliasu on non-special vnode"); 1930 dev = findcdev(nvp_rdev); 1931 if (dev == NULL) 1932 return (nvp); 1933 /* 1934 * Check to see if we have a bdevvp vnode with no associated 1935 * filesystem. If so, we want to associate the filesystem of 1936 * the new newly instigated vnode with the bdevvp vnode and 1937 * discard the newly created vnode rather than leaving the 1938 * bdevvp vnode lying around with no associated filesystem. 1939 */ 1940 if (vfinddev(dev, &ovp) == 0 || ovp->v_data != NULL) { 1941 addalias(nvp, dev); 1942 return (nvp); 1943 } 1944 /* 1945 * Discard unneeded vnode, but save its node specific data. 1946 * Note that if there is a lock, it is carried over in the 1947 * node specific data to the replacement vnode. 1948 */ 1949 vref(ovp); 1950 ovp->v_data = nvp->v_data; 1951 ovp->v_tag = nvp->v_tag; 1952 nvp->v_data = NULL; 1953 lockdestroy(ovp->v_vnlock); 1954 lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, 1955 nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); 1956 ops = ovp->v_op; 1957 ovp->v_op = nvp->v_op; 1958 if (VOP_ISLOCKED(nvp, curthread)) { 1959 VOP_UNLOCK(nvp, 0, curthread); 1960 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 1961 } 1962 nvp->v_op = ops; 1963 delmntque(ovp); 1964 insmntque(ovp, nvp->v_mount); 1965 vrele(nvp); 1966 vgone(nvp); 1967 return (ovp); 1968 } 1969 1970 /* This is a local helper function that do the same as addaliasu, but for a 1971 * struct cdev *instead of an dev_t. */ 1972 static void 1973 addalias(nvp, dev) 1974 struct vnode *nvp; 1975 struct cdev *dev; 1976 { 1977 1978 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 1979 dev_ref(dev); 1980 nvp->v_rdev = dev; 1981 VI_LOCK(nvp); 1982 mtx_lock(&spechash_mtx); 1983 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 1984 dev->si_usecount += nvp->v_usecount; 1985 mtx_unlock(&spechash_mtx); 1986 VI_UNLOCK(nvp); 1987 } 1988 1989 /* 1990 * Grab a particular vnode from the free list, increment its 1991 * reference count and lock it. The vnode lock bit is set if the 1992 * vnode is being eliminated in vgone. The process is awakened 1993 * when the transition is completed, and an error returned to 1994 * indicate that the vnode is no longer usable (possibly having 1995 * been changed to a new filesystem type). 1996 */ 1997 int 1998 vget(vp, flags, td) 1999 register struct vnode *vp; 2000 int flags; 2001 struct thread *td; 2002 { 2003 int error; 2004 2005 /* 2006 * If the vnode is in the process of being cleaned out for 2007 * another use, we wait for the cleaning to finish and then 2008 * return failure. Cleaning is determined by checking that 2009 * the VI_XLOCK flag is set. 2010 */ 2011 if ((flags & LK_INTERLOCK) == 0) 2012 VI_LOCK(vp); 2013 if (vp->v_iflag & VI_XLOCK && vp->v_vxthread != curthread) { 2014 if ((flags & LK_NOWAIT) == 0) { 2015 vp->v_iflag |= VI_XWANT; 2016 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); 2017 return (ENOENT); 2018 } 2019 VI_UNLOCK(vp); 2020 return (EBUSY); 2021 } 2022 2023 v_incr_usecount(vp, 1); 2024 2025 if (VSHOULDBUSY(vp)) 2026 vbusy(vp); 2027 if (flags & LK_TYPE_MASK) { 2028 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 2029 /* 2030 * must expand vrele here because we do not want 2031 * to call VOP_INACTIVE if the reference count 2032 * drops back to zero since it was never really 2033 * active. We must remove it from the free list 2034 * before sleeping so that multiple processes do 2035 * not try to recycle it. 2036 */ 2037 VI_LOCK(vp); 2038 v_incr_usecount(vp, -1); 2039 if (VSHOULDFREE(vp)) 2040 vfree(vp); 2041 else 2042 vlruvp(vp); 2043 VI_UNLOCK(vp); 2044 } 2045 return (error); 2046 } 2047 VI_UNLOCK(vp); 2048 return (0); 2049 } 2050 2051 /* 2052 * Increase the reference count of a vnode. 2053 */ 2054 void 2055 vref(struct vnode *vp) 2056 { 2057 2058 VI_LOCK(vp); 2059 v_incr_usecount(vp, 1); 2060 VI_UNLOCK(vp); 2061 } 2062 2063 /* 2064 * Return reference count of a vnode. 2065 * 2066 * The results of this call are only guaranteed when some mechanism other 2067 * than the VI lock is used to stop other processes from gaining references 2068 * to the vnode. This may be the case if the caller holds the only reference. 2069 * This is also useful when stale data is acceptable as race conditions may 2070 * be accounted for by some other means. 2071 */ 2072 int 2073 vrefcnt(struct vnode *vp) 2074 { 2075 int usecnt; 2076 2077 VI_LOCK(vp); 2078 usecnt = vp->v_usecount; 2079 VI_UNLOCK(vp); 2080 2081 return (usecnt); 2082 } 2083 2084 2085 /* 2086 * Vnode put/release. 2087 * If count drops to zero, call inactive routine and return to freelist. 2088 */ 2089 void 2090 vrele(vp) 2091 struct vnode *vp; 2092 { 2093 struct thread *td = curthread; /* XXX */ 2094 2095 GIANT_REQUIRED; 2096 2097 KASSERT(vp != NULL, ("vrele: null vp")); 2098 2099 VI_LOCK(vp); 2100 2101 /* Skip this v_writecount check if we're going to panic below. */ 2102 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2103 ("vrele: missed vn_close")); 2104 2105 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2106 vp->v_usecount == 1)) { 2107 v_incr_usecount(vp, -1); 2108 VI_UNLOCK(vp); 2109 2110 return; 2111 } 2112 2113 if (vp->v_usecount == 1) { 2114 v_incr_usecount(vp, -1); 2115 /* 2116 * We must call VOP_INACTIVE with the node locked. Mark 2117 * as VI_DOINGINACT to avoid recursion. 2118 */ 2119 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 2120 VI_LOCK(vp); 2121 vp->v_iflag |= VI_DOINGINACT; 2122 VI_UNLOCK(vp); 2123 VOP_INACTIVE(vp, td); 2124 VI_LOCK(vp); 2125 KASSERT(vp->v_iflag & VI_DOINGINACT, 2126 ("vrele: lost VI_DOINGINACT")); 2127 vp->v_iflag &= ~VI_DOINGINACT; 2128 } else 2129 VI_LOCK(vp); 2130 if (VSHOULDFREE(vp)) 2131 vfree(vp); 2132 else 2133 vlruvp(vp); 2134 VI_UNLOCK(vp); 2135 2136 } else { 2137 #ifdef DIAGNOSTIC 2138 vprint("vrele: negative ref count", vp); 2139 #endif 2140 VI_UNLOCK(vp); 2141 panic("vrele: negative ref cnt"); 2142 } 2143 } 2144 2145 /* 2146 * Release an already locked vnode. This give the same effects as 2147 * unlock+vrele(), but takes less time and avoids releasing and 2148 * re-aquiring the lock (as vrele() aquires the lock internally.) 2149 */ 2150 void 2151 vput(vp) 2152 struct vnode *vp; 2153 { 2154 struct thread *td = curthread; /* XXX */ 2155 2156 GIANT_REQUIRED; 2157 2158 KASSERT(vp != NULL, ("vput: null vp")); 2159 VI_LOCK(vp); 2160 /* Skip this v_writecount check if we're going to panic below. */ 2161 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2162 ("vput: missed vn_close")); 2163 2164 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2165 vp->v_usecount == 1)) { 2166 v_incr_usecount(vp, -1); 2167 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2168 return; 2169 } 2170 2171 if (vp->v_usecount == 1) { 2172 v_incr_usecount(vp, -1); 2173 /* 2174 * We must call VOP_INACTIVE with the node locked, so 2175 * we just need to release the vnode mutex. Mark as 2176 * as VI_DOINGINACT to avoid recursion. 2177 */ 2178 vp->v_iflag |= VI_DOINGINACT; 2179 VI_UNLOCK(vp); 2180 VOP_INACTIVE(vp, td); 2181 VI_LOCK(vp); 2182 KASSERT(vp->v_iflag & VI_DOINGINACT, 2183 ("vput: lost VI_DOINGINACT")); 2184 vp->v_iflag &= ~VI_DOINGINACT; 2185 if (VSHOULDFREE(vp)) 2186 vfree(vp); 2187 else 2188 vlruvp(vp); 2189 VI_UNLOCK(vp); 2190 2191 } else { 2192 #ifdef DIAGNOSTIC 2193 vprint("vput: negative ref count", vp); 2194 #endif 2195 panic("vput: negative ref cnt"); 2196 } 2197 } 2198 2199 /* 2200 * Somebody doesn't want the vnode recycled. 2201 */ 2202 void 2203 vhold(struct vnode *vp) 2204 { 2205 2206 VI_LOCK(vp); 2207 vholdl(vp); 2208 VI_UNLOCK(vp); 2209 } 2210 2211 void 2212 vholdl(vp) 2213 register struct vnode *vp; 2214 { 2215 2216 vp->v_holdcnt++; 2217 if (VSHOULDBUSY(vp)) 2218 vbusy(vp); 2219 } 2220 2221 /* 2222 * Note that there is one less who cares about this vnode. vdrop() is the 2223 * opposite of vhold(). 2224 */ 2225 void 2226 vdrop(struct vnode *vp) 2227 { 2228 2229 VI_LOCK(vp); 2230 vdropl(vp); 2231 VI_UNLOCK(vp); 2232 } 2233 2234 void 2235 vdropl(vp) 2236 register struct vnode *vp; 2237 { 2238 2239 if (vp->v_holdcnt <= 0) 2240 panic("vdrop: holdcnt"); 2241 vp->v_holdcnt--; 2242 if (VSHOULDFREE(vp)) 2243 vfree(vp); 2244 else 2245 vlruvp(vp); 2246 } 2247 2248 /* 2249 * Remove any vnodes in the vnode table belonging to mount point mp. 2250 * 2251 * If FORCECLOSE is not specified, there should not be any active ones, 2252 * return error if any are found (nb: this is a user error, not a 2253 * system error). If FORCECLOSE is specified, detach any active vnodes 2254 * that are found. 2255 * 2256 * If WRITECLOSE is set, only flush out regular file vnodes open for 2257 * writing. 2258 * 2259 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2260 * 2261 * `rootrefs' specifies the base reference count for the root vnode 2262 * of this filesystem. The root vnode is considered busy if its 2263 * v_usecount exceeds this value. On a successful return, vflush(, td) 2264 * will call vrele() on the root vnode exactly rootrefs times. 2265 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2266 * be zero. 2267 */ 2268 #ifdef DIAGNOSTIC 2269 static int busyprt = 0; /* print out busy vnodes */ 2270 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2271 #endif 2272 2273 int 2274 vflush(mp, rootrefs, flags, td) 2275 struct mount *mp; 2276 int rootrefs; 2277 int flags; 2278 struct thread *td; 2279 { 2280 struct vnode *vp, *nvp, *rootvp = NULL; 2281 struct vattr vattr; 2282 int busy = 0, error; 2283 2284 if (rootrefs > 0) { 2285 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2286 ("vflush: bad args")); 2287 /* 2288 * Get the filesystem root vnode. We can vput() it 2289 * immediately, since with rootrefs > 0, it won't go away. 2290 */ 2291 if ((error = VFS_ROOT(mp, &rootvp, td)) != 0) 2292 return (error); 2293 vput(rootvp); 2294 2295 } 2296 MNT_ILOCK(mp); 2297 loop: 2298 MNT_VNODE_FOREACH(vp, mp, nvp) { 2299 2300 VI_LOCK(vp); 2301 MNT_IUNLOCK(mp); 2302 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td); 2303 if (error) { 2304 MNT_ILOCK(mp); 2305 goto loop; 2306 } 2307 /* 2308 * Skip over a vnodes marked VV_SYSTEM. 2309 */ 2310 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2311 VOP_UNLOCK(vp, 0, td); 2312 MNT_ILOCK(mp); 2313 continue; 2314 } 2315 /* 2316 * If WRITECLOSE is set, flush out unlinked but still open 2317 * files (even if open only for reading) and regular file 2318 * vnodes open for writing. 2319 */ 2320 if (flags & WRITECLOSE) { 2321 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2322 VI_LOCK(vp); 2323 2324 if ((vp->v_type == VNON || 2325 (error == 0 && vattr.va_nlink > 0)) && 2326 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2327 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2328 MNT_ILOCK(mp); 2329 continue; 2330 } 2331 } else 2332 VI_LOCK(vp); 2333 2334 VOP_UNLOCK(vp, 0, td); 2335 2336 /* 2337 * With v_usecount == 0, all we need to do is clear out the 2338 * vnode data structures and we are done. 2339 */ 2340 if (vp->v_usecount == 0) { 2341 vgonel(vp, td); 2342 MNT_ILOCK(mp); 2343 continue; 2344 } 2345 2346 /* 2347 * If FORCECLOSE is set, forcibly close the vnode. For block 2348 * or character devices, revert to an anonymous device. For 2349 * all other files, just kill them. 2350 */ 2351 if (flags & FORCECLOSE) { 2352 if (vp->v_type != VCHR) 2353 vgonel(vp, td); 2354 else 2355 vgonechrl(vp, td); 2356 MNT_ILOCK(mp); 2357 continue; 2358 } 2359 #ifdef DIAGNOSTIC 2360 if (busyprt) 2361 vprint("vflush: busy vnode", vp); 2362 #endif 2363 VI_UNLOCK(vp); 2364 MNT_ILOCK(mp); 2365 busy++; 2366 } 2367 MNT_IUNLOCK(mp); 2368 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2369 /* 2370 * If just the root vnode is busy, and if its refcount 2371 * is equal to `rootrefs', then go ahead and kill it. 2372 */ 2373 VI_LOCK(rootvp); 2374 KASSERT(busy > 0, ("vflush: not busy")); 2375 KASSERT(rootvp->v_usecount >= rootrefs, 2376 ("vflush: usecount %d < rootrefs %d", 2377 rootvp->v_usecount, rootrefs)); 2378 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2379 vgonel(rootvp, td); 2380 busy = 0; 2381 } else 2382 VI_UNLOCK(rootvp); 2383 } 2384 if (busy) 2385 return (EBUSY); 2386 for (; rootrefs > 0; rootrefs--) 2387 vrele(rootvp); 2388 return (0); 2389 } 2390 2391 /* 2392 * This moves a now (likely recyclable) vnode to the end of the 2393 * mountlist. XXX However, it is temporarily disabled until we 2394 * can clean up ffs_sync() and friends, which have loop restart 2395 * conditions which this code causes to operate O(N^2). 2396 */ 2397 static void 2398 vlruvp(struct vnode *vp) 2399 { 2400 #if 0 2401 struct mount *mp; 2402 2403 if ((mp = vp->v_mount) != NULL) { 2404 MNT_ILOCK(mp); 2405 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2406 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2407 MNT_IUNLOCK(mp); 2408 } 2409 #endif 2410 } 2411 2412 static void 2413 vx_lock(struct vnode *vp) 2414 { 2415 2416 ASSERT_VI_LOCKED(vp, "vx_lock"); 2417 2418 /* 2419 * Prevent the vnode from being recycled or brought into use while we 2420 * clean it out. 2421 */ 2422 if (vp->v_iflag & VI_XLOCK) 2423 panic("vclean: deadlock"); 2424 vp->v_iflag |= VI_XLOCK; 2425 vp->v_vxthread = curthread; 2426 } 2427 2428 static void 2429 vx_unlock(struct vnode *vp) 2430 { 2431 ASSERT_VI_LOCKED(vp, "vx_unlock"); 2432 vp->v_iflag &= ~VI_XLOCK; 2433 vp->v_vxthread = NULL; 2434 if (vp->v_iflag & VI_XWANT) { 2435 vp->v_iflag &= ~VI_XWANT; 2436 wakeup(vp); 2437 } 2438 } 2439 2440 /* 2441 * Disassociate the underlying filesystem from a vnode. 2442 */ 2443 static void 2444 vclean(vp, flags, td) 2445 struct vnode *vp; 2446 int flags; 2447 struct thread *td; 2448 { 2449 int active; 2450 2451 ASSERT_VI_LOCKED(vp, "vclean"); 2452 /* 2453 * Check to see if the vnode is in use. If so we have to reference it 2454 * before we clean it out so that its count cannot fall to zero and 2455 * generate a race against ourselves to recycle it. 2456 */ 2457 if ((active = vp->v_usecount)) 2458 v_incr_usecount(vp, 1); 2459 2460 /* 2461 * Even if the count is zero, the VOP_INACTIVE routine may still 2462 * have the object locked while it cleans it out. The VOP_LOCK 2463 * ensures that the VOP_INACTIVE routine is done with its work. 2464 * For active vnodes, it ensures that no other activity can 2465 * occur while the underlying object is being cleaned out. 2466 */ 2467 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2468 2469 /* 2470 * Clean out any buffers associated with the vnode. 2471 * If the flush fails, just toss the buffers. 2472 */ 2473 if (flags & DOCLOSE) { 2474 struct buf *bp; 2475 bp = TAILQ_FIRST(&vp->v_dirtyblkhd); 2476 if (bp != NULL) 2477 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2478 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2479 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2480 } 2481 2482 VOP_DESTROYVOBJECT(vp); 2483 2484 /* 2485 * Any other processes trying to obtain this lock must first 2486 * wait for VXLOCK to clear, then call the new lock operation. 2487 */ 2488 VOP_UNLOCK(vp, 0, td); 2489 2490 /* 2491 * If purging an active vnode, it must be closed and 2492 * deactivated before being reclaimed. Note that the 2493 * VOP_INACTIVE will unlock the vnode. 2494 */ 2495 if (active) { 2496 if (flags & DOCLOSE) 2497 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2498 VI_LOCK(vp); 2499 if ((vp->v_iflag & VI_DOINGINACT) == 0) { 2500 vp->v_iflag |= VI_DOINGINACT; 2501 VI_UNLOCK(vp); 2502 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2503 panic("vclean: cannot relock."); 2504 VOP_INACTIVE(vp, td); 2505 VI_LOCK(vp); 2506 KASSERT(vp->v_iflag & VI_DOINGINACT, 2507 ("vclean: lost VI_DOINGINACT")); 2508 vp->v_iflag &= ~VI_DOINGINACT; 2509 } 2510 VI_UNLOCK(vp); 2511 } 2512 /* 2513 * Reclaim the vnode. 2514 */ 2515 if (VOP_RECLAIM(vp, td)) 2516 panic("vclean: cannot reclaim"); 2517 2518 if (active) { 2519 /* 2520 * Inline copy of vrele() since VOP_INACTIVE 2521 * has already been called. 2522 */ 2523 VI_LOCK(vp); 2524 v_incr_usecount(vp, -1); 2525 if (vp->v_usecount <= 0) { 2526 #ifdef INVARIANTS 2527 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2528 vprint("vclean: bad ref count", vp); 2529 panic("vclean: ref cnt"); 2530 } 2531 #endif 2532 if (VSHOULDFREE(vp)) 2533 vfree(vp); 2534 } 2535 VI_UNLOCK(vp); 2536 } 2537 /* 2538 * Delete from old mount point vnode list. 2539 */ 2540 delmntque(vp); 2541 cache_purge(vp); 2542 VI_LOCK(vp); 2543 if (VSHOULDFREE(vp)) 2544 vfree(vp); 2545 2546 /* 2547 * Done with purge, reset to the standard lock and 2548 * notify sleepers of the grim news. 2549 */ 2550 vp->v_vnlock = &vp->v_lock; 2551 vp->v_op = dead_vnodeop_p; 2552 if (vp->v_pollinfo != NULL) 2553 vn_pollgone(vp); 2554 vp->v_tag = "none"; 2555 } 2556 2557 /* 2558 * Eliminate all activity associated with the requested vnode 2559 * and with all vnodes aliased to the requested vnode. 2560 */ 2561 int 2562 vop_revoke(ap) 2563 struct vop_revoke_args /* { 2564 struct vnode *a_vp; 2565 int a_flags; 2566 } */ *ap; 2567 { 2568 struct vnode *vp, *vq; 2569 struct cdev *dev; 2570 2571 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2572 vp = ap->a_vp; 2573 KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); 2574 2575 VI_LOCK(vp); 2576 /* 2577 * If a vgone (or vclean) is already in progress, 2578 * wait until it is done and return. 2579 */ 2580 if (vp->v_iflag & VI_XLOCK) { 2581 vp->v_iflag |= VI_XWANT; 2582 msleep(vp, VI_MTX(vp), PINOD | PDROP, 2583 "vop_revokeall", 0); 2584 return (0); 2585 } 2586 VI_UNLOCK(vp); 2587 dev = vp->v_rdev; 2588 for (;;) { 2589 mtx_lock(&spechash_mtx); 2590 vq = SLIST_FIRST(&dev->si_hlist); 2591 mtx_unlock(&spechash_mtx); 2592 if (vq == NULL) 2593 break; 2594 vgone(vq); 2595 } 2596 return (0); 2597 } 2598 2599 /* 2600 * Recycle an unused vnode to the front of the free list. 2601 * Release the passed interlock if the vnode will be recycled. 2602 */ 2603 int 2604 vrecycle(vp, inter_lkp, td) 2605 struct vnode *vp; 2606 struct mtx *inter_lkp; 2607 struct thread *td; 2608 { 2609 2610 VI_LOCK(vp); 2611 if (vp->v_usecount == 0) { 2612 if (inter_lkp) { 2613 mtx_unlock(inter_lkp); 2614 } 2615 vgonel(vp, td); 2616 return (1); 2617 } 2618 VI_UNLOCK(vp); 2619 return (0); 2620 } 2621 2622 /* 2623 * Eliminate all activity associated with a vnode 2624 * in preparation for reuse. 2625 */ 2626 void 2627 vgone(vp) 2628 register struct vnode *vp; 2629 { 2630 struct thread *td = curthread; /* XXX */ 2631 2632 VI_LOCK(vp); 2633 vgonel(vp, td); 2634 } 2635 2636 /* 2637 * Disassociate a character device from the its underlying filesystem and 2638 * attach it to spec. This is for use when the chr device is still active 2639 * and the filesystem is going away. 2640 */ 2641 static void 2642 vgonechrl(struct vnode *vp, struct thread *td) 2643 { 2644 ASSERT_VI_LOCKED(vp, "vgonechrl"); 2645 vx_lock(vp); 2646 /* 2647 * This is a custom version of vclean() which does not tearm down 2648 * the bufs or vm objects held by this vnode. This allows filesystems 2649 * to continue using devices which were discovered via another 2650 * filesystem that has been unmounted. 2651 */ 2652 if (vp->v_usecount != 0) { 2653 v_incr_usecount(vp, 1); 2654 /* 2655 * Ensure that no other activity can occur while the 2656 * underlying object is being cleaned out. 2657 */ 2658 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2659 /* 2660 * Any other processes trying to obtain this lock must first 2661 * wait for VXLOCK to clear, then call the new lock operation. 2662 */ 2663 VOP_UNLOCK(vp, 0, td); 2664 vp->v_vnlock = &vp->v_lock; 2665 vp->v_tag = "orphanchr"; 2666 vp->v_op = spec_vnodeop_p; 2667 delmntque(vp); 2668 cache_purge(vp); 2669 vrele(vp); 2670 VI_LOCK(vp); 2671 } else 2672 vclean(vp, 0, td); 2673 vp->v_op = spec_vnodeop_p; 2674 vx_unlock(vp); 2675 VI_UNLOCK(vp); 2676 } 2677 2678 /* 2679 * vgone, with the vp interlock held. 2680 */ 2681 void 2682 vgonel(vp, td) 2683 struct vnode *vp; 2684 struct thread *td; 2685 { 2686 /* 2687 * If a vgone (or vclean) is already in progress, 2688 * wait until it is done and return. 2689 */ 2690 ASSERT_VI_LOCKED(vp, "vgonel"); 2691 if (vp->v_iflag & VI_XLOCK) { 2692 vp->v_iflag |= VI_XWANT; 2693 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); 2694 return; 2695 } 2696 vx_lock(vp); 2697 2698 /* 2699 * Clean out the filesystem specific data. 2700 */ 2701 vclean(vp, DOCLOSE, td); 2702 VI_UNLOCK(vp); 2703 2704 /* 2705 * If special device, remove it from special device alias list 2706 * if it is on one. 2707 */ 2708 VI_LOCK(vp); 2709 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2710 mtx_lock(&spechash_mtx); 2711 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2712 vp->v_rdev->si_usecount -= vp->v_usecount; 2713 mtx_unlock(&spechash_mtx); 2714 dev_rel(vp->v_rdev); 2715 vp->v_rdev = NULL; 2716 } 2717 2718 /* 2719 * If it is on the freelist and not already at the head, 2720 * move it to the head of the list. The test of the 2721 * VDOOMED flag and the reference count of zero is because 2722 * it will be removed from the free list by getnewvnode, 2723 * but will not have its reference count incremented until 2724 * after calling vgone. If the reference count were 2725 * incremented first, vgone would (incorrectly) try to 2726 * close the previous instance of the underlying object. 2727 */ 2728 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2729 mtx_lock(&vnode_free_list_mtx); 2730 if (vp->v_iflag & VI_FREE) { 2731 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2732 } else { 2733 vp->v_iflag |= VI_FREE; 2734 freevnodes++; 2735 } 2736 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2737 mtx_unlock(&vnode_free_list_mtx); 2738 } 2739 2740 vp->v_type = VBAD; 2741 vx_unlock(vp); 2742 VI_UNLOCK(vp); 2743 } 2744 2745 /* 2746 * Lookup a vnode by device number. 2747 */ 2748 int 2749 vfinddev(dev, vpp) 2750 struct cdev *dev; 2751 struct vnode **vpp; 2752 { 2753 struct vnode *vp; 2754 2755 mtx_lock(&spechash_mtx); 2756 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2757 *vpp = vp; 2758 mtx_unlock(&spechash_mtx); 2759 return (1); 2760 } 2761 mtx_unlock(&spechash_mtx); 2762 return (0); 2763 } 2764 2765 /* 2766 * Calculate the total number of references to a special device. 2767 */ 2768 int 2769 vcount(vp) 2770 struct vnode *vp; 2771 { 2772 int count; 2773 2774 mtx_lock(&spechash_mtx); 2775 count = vp->v_rdev->si_usecount; 2776 mtx_unlock(&spechash_mtx); 2777 return (count); 2778 } 2779 2780 /* 2781 * Same as above, but using the struct cdev *as argument 2782 */ 2783 int 2784 count_dev(dev) 2785 struct cdev *dev; 2786 { 2787 int count; 2788 2789 mtx_lock(&spechash_mtx); 2790 count = dev->si_usecount; 2791 mtx_unlock(&spechash_mtx); 2792 return(count); 2793 } 2794 2795 /* 2796 * Print out a description of a vnode. 2797 */ 2798 static char *typename[] = 2799 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2800 2801 void 2802 vprint(label, vp) 2803 char *label; 2804 struct vnode *vp; 2805 { 2806 char buf[96]; 2807 2808 if (label != NULL) 2809 printf("%s: %p: ", label, (void *)vp); 2810 else 2811 printf("%p: ", (void *)vp); 2812 printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", 2813 vp->v_tag, typename[vp->v_type], vp->v_usecount, 2814 vp->v_writecount, vp->v_holdcnt); 2815 buf[0] = '\0'; 2816 if (vp->v_vflag & VV_ROOT) 2817 strcat(buf, "|VV_ROOT"); 2818 if (vp->v_vflag & VV_TEXT) 2819 strcat(buf, "|VV_TEXT"); 2820 if (vp->v_vflag & VV_SYSTEM) 2821 strcat(buf, "|VV_SYSTEM"); 2822 if (vp->v_iflag & VI_XLOCK) 2823 strcat(buf, "|VI_XLOCK"); 2824 if (vp->v_iflag & VI_XWANT) 2825 strcat(buf, "|VI_XWANT"); 2826 if (vp->v_iflag & VI_BWAIT) 2827 strcat(buf, "|VI_BWAIT"); 2828 if (vp->v_iflag & VI_DOOMED) 2829 strcat(buf, "|VI_DOOMED"); 2830 if (vp->v_iflag & VI_FREE) 2831 strcat(buf, "|VI_FREE"); 2832 if (vp->v_vflag & VV_OBJBUF) 2833 strcat(buf, "|VV_OBJBUF"); 2834 if (buf[0] != '\0') 2835 printf(" flags (%s),", &buf[1]); 2836 lockmgr_printinfo(vp->v_vnlock); 2837 printf("\n"); 2838 if (vp->v_data != NULL) 2839 VOP_PRINT(vp); 2840 } 2841 2842 #ifdef DDB 2843 #include <ddb/ddb.h> 2844 /* 2845 * List all of the locked vnodes in the system. 2846 * Called when debugging the kernel. 2847 */ 2848 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2849 { 2850 struct mount *mp, *nmp; 2851 struct vnode *vp; 2852 2853 /* 2854 * Note: because this is DDB, we can't obey the locking semantics 2855 * for these structures, which means we could catch an inconsistent 2856 * state and dereference a nasty pointer. Not much to be done 2857 * about that. 2858 */ 2859 printf("Locked vnodes\n"); 2860 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2861 nmp = TAILQ_NEXT(mp, mnt_list); 2862 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2863 if (VOP_ISLOCKED(vp, NULL)) 2864 vprint(NULL, vp); 2865 } 2866 nmp = TAILQ_NEXT(mp, mnt_list); 2867 } 2868 } 2869 #endif 2870 2871 /* 2872 * Fill in a struct xvfsconf based on a struct vfsconf. 2873 */ 2874 static void 2875 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2876 { 2877 2878 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2879 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2880 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2881 xvfsp->vfc_flags = vfsp->vfc_flags; 2882 /* 2883 * These are unused in userland, we keep them 2884 * to not break binary compatibility. 2885 */ 2886 xvfsp->vfc_vfsops = NULL; 2887 xvfsp->vfc_next = NULL; 2888 } 2889 2890 /* 2891 * Top level filesystem related information gathering. 2892 */ 2893 static int 2894 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2895 { 2896 struct vfsconf *vfsp; 2897 struct xvfsconf xvfsp; 2898 int error; 2899 2900 error = 0; 2901 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2902 vfsconf2x(vfsp, &xvfsp); 2903 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); 2904 if (error) 2905 break; 2906 } 2907 return (error); 2908 } 2909 2910 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2911 "S,xvfsconf", "List of all configured filesystems"); 2912 2913 #ifndef BURN_BRIDGES 2914 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2915 2916 static int 2917 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2918 { 2919 int *name = (int *)arg1 - 1; /* XXX */ 2920 u_int namelen = arg2 + 1; /* XXX */ 2921 struct vfsconf *vfsp; 2922 struct xvfsconf xvfsp; 2923 2924 printf("WARNING: userland calling deprecated sysctl, " 2925 "please rebuild world\n"); 2926 2927 #if 1 || defined(COMPAT_PRELITE2) 2928 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2929 if (namelen == 1) 2930 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2931 #endif 2932 2933 switch (name[1]) { 2934 case VFS_MAXTYPENUM: 2935 if (namelen != 2) 2936 return (ENOTDIR); 2937 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2938 case VFS_CONF: 2939 if (namelen != 3) 2940 return (ENOTDIR); /* overloaded */ 2941 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 2942 if (vfsp->vfc_typenum == name[2]) 2943 break; 2944 if (vfsp == NULL) 2945 return (EOPNOTSUPP); 2946 vfsconf2x(vfsp, &xvfsp); 2947 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2948 } 2949 return (EOPNOTSUPP); 2950 } 2951 2952 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 2953 "Generic filesystem"); 2954 2955 #if 1 || defined(COMPAT_PRELITE2) 2956 2957 static int 2958 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2959 { 2960 int error; 2961 struct vfsconf *vfsp; 2962 struct ovfsconf ovfs; 2963 2964 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2965 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2966 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2967 ovfs.vfc_index = vfsp->vfc_typenum; 2968 ovfs.vfc_refcount = vfsp->vfc_refcount; 2969 ovfs.vfc_flags = vfsp->vfc_flags; 2970 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2971 if (error) 2972 return error; 2973 } 2974 return 0; 2975 } 2976 2977 #endif /* 1 || COMPAT_PRELITE2 */ 2978 #endif /* !BURN_BRIDGES */ 2979 2980 #define KINFO_VNODESLOP 10 2981 #ifdef notyet 2982 /* 2983 * Dump vnode list (via sysctl). 2984 */ 2985 /* ARGSUSED */ 2986 static int 2987 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2988 { 2989 struct xvnode *xvn; 2990 struct thread *td = req->td; 2991 struct mount *mp; 2992 struct vnode *vp; 2993 int error, len, n; 2994 2995 /* 2996 * Stale numvnodes access is not fatal here. 2997 */ 2998 req->lock = 0; 2999 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3000 if (!req->oldptr) 3001 /* Make an estimate */ 3002 return (SYSCTL_OUT(req, 0, len)); 3003 3004 error = sysctl_wire_old_buffer(req, 0); 3005 if (error != 0) 3006 return (error); 3007 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3008 n = 0; 3009 mtx_lock(&mountlist_mtx); 3010 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3011 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 3012 continue; 3013 MNT_ILOCK(mp); 3014 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3015 if (n == len) 3016 break; 3017 vref(vp); 3018 xvn[n].xv_size = sizeof *xvn; 3019 xvn[n].xv_vnode = vp; 3020 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3021 XV_COPY(usecount); 3022 XV_COPY(writecount); 3023 XV_COPY(holdcnt); 3024 XV_COPY(id); 3025 XV_COPY(mount); 3026 XV_COPY(numoutput); 3027 XV_COPY(type); 3028 #undef XV_COPY 3029 xvn[n].xv_flag = vp->v_vflag; 3030 3031 switch (vp->v_type) { 3032 case VREG: 3033 case VDIR: 3034 case VLNK: 3035 xvn[n].xv_dev = vp->v_cachedfs; 3036 xvn[n].xv_ino = vp->v_cachedid; 3037 break; 3038 case VBLK: 3039 case VCHR: 3040 if (vp->v_rdev == NULL) { 3041 vrele(vp); 3042 continue; 3043 } 3044 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3045 break; 3046 case VSOCK: 3047 xvn[n].xv_socket = vp->v_socket; 3048 break; 3049 case VFIFO: 3050 xvn[n].xv_fifo = vp->v_fifoinfo; 3051 break; 3052 case VNON: 3053 case VBAD: 3054 default: 3055 /* shouldn't happen? */ 3056 vrele(vp); 3057 continue; 3058 } 3059 vrele(vp); 3060 ++n; 3061 } 3062 MNT_IUNLOCK(mp); 3063 mtx_lock(&mountlist_mtx); 3064 vfs_unbusy(mp, td); 3065 if (n == len) 3066 break; 3067 } 3068 mtx_unlock(&mountlist_mtx); 3069 3070 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3071 free(xvn, M_TEMP); 3072 return (error); 3073 } 3074 3075 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 3076 0, 0, sysctl_vnode, "S,xvnode", ""); 3077 #endif 3078 3079 /* 3080 * Check to see if a filesystem is mounted on a block device. 3081 */ 3082 int 3083 vfs_mountedon(vp) 3084 struct vnode *vp; 3085 { 3086 3087 if (vp->v_rdev->si_mountpoint != NULL) 3088 return (EBUSY); 3089 return (0); 3090 } 3091 3092 /* 3093 * Unmount all filesystems. The list is traversed in reverse order 3094 * of mounting to avoid dependencies. 3095 */ 3096 void 3097 vfs_unmountall() 3098 { 3099 struct mount *mp; 3100 struct thread *td; 3101 int error; 3102 3103 if (curthread != NULL) 3104 td = curthread; 3105 else 3106 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 3107 /* 3108 * Since this only runs when rebooting, it is not interlocked. 3109 */ 3110 while(!TAILQ_EMPTY(&mountlist)) { 3111 mp = TAILQ_LAST(&mountlist, mntlist); 3112 error = dounmount(mp, MNT_FORCE, td); 3113 if (error) { 3114 TAILQ_REMOVE(&mountlist, mp, mnt_list); 3115 printf("unmount of %s failed (", 3116 mp->mnt_stat.f_mntonname); 3117 if (error == EBUSY) 3118 printf("BUSY)\n"); 3119 else 3120 printf("%d)\n", error); 3121 } else { 3122 /* The unmount has removed mp from the mountlist */ 3123 } 3124 } 3125 } 3126 3127 /* 3128 * perform msync on all vnodes under a mount point 3129 * the mount point must be locked. 3130 */ 3131 void 3132 vfs_msync(struct mount *mp, int flags) 3133 { 3134 struct vnode *vp, *nvp; 3135 struct vm_object *obj; 3136 int tries; 3137 3138 GIANT_REQUIRED; 3139 3140 tries = 5; 3141 MNT_ILOCK(mp); 3142 loop: 3143 TAILQ_FOREACH_SAFE(vp, &mp->mnt_nvnodelist, v_nmntvnodes, nvp) { 3144 if (vp->v_mount != mp) { 3145 if (--tries > 0) 3146 goto loop; 3147 break; 3148 } 3149 3150 VI_LOCK(vp); 3151 if (vp->v_iflag & VI_XLOCK) { 3152 VI_UNLOCK(vp); 3153 continue; 3154 } 3155 3156 if ((vp->v_iflag & VI_OBJDIRTY) && 3157 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 3158 MNT_IUNLOCK(mp); 3159 if (!vget(vp, 3160 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3161 curthread)) { 3162 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3163 vput(vp); 3164 MNT_ILOCK(mp); 3165 continue; 3166 } 3167 3168 if (VOP_GETVOBJECT(vp, &obj) == 0) { 3169 VM_OBJECT_LOCK(obj); 3170 vm_object_page_clean(obj, 0, 0, 3171 flags == MNT_WAIT ? 3172 OBJPC_SYNC : OBJPC_NOSYNC); 3173 VM_OBJECT_UNLOCK(obj); 3174 } 3175 vput(vp); 3176 } 3177 MNT_ILOCK(mp); 3178 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3179 if (--tries > 0) 3180 goto loop; 3181 break; 3182 } 3183 } else 3184 VI_UNLOCK(vp); 3185 } 3186 MNT_IUNLOCK(mp); 3187 } 3188 3189 /* 3190 * Create the VM object needed for VMIO and mmap support. This 3191 * is done for all VREG files in the system. Some filesystems might 3192 * afford the additional metadata buffering capability of the 3193 * VMIO code by making the device node be VMIO mode also. 3194 * 3195 * vp must be locked when vfs_object_create is called. 3196 */ 3197 int 3198 vfs_object_create(vp, td, cred) 3199 struct vnode *vp; 3200 struct thread *td; 3201 struct ucred *cred; 3202 { 3203 3204 GIANT_REQUIRED; 3205 return (VOP_CREATEVOBJECT(vp, cred, td)); 3206 } 3207 3208 /* 3209 * Mark a vnode as free, putting it up for recycling. 3210 */ 3211 void 3212 vfree(vp) 3213 struct vnode *vp; 3214 { 3215 3216 ASSERT_VI_LOCKED(vp, "vfree"); 3217 mtx_lock(&vnode_free_list_mtx); 3218 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3219 if (vp->v_iflag & VI_AGE) { 3220 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3221 } else { 3222 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3223 } 3224 freevnodes++; 3225 mtx_unlock(&vnode_free_list_mtx); 3226 vp->v_iflag &= ~VI_AGE; 3227 vp->v_iflag |= VI_FREE; 3228 } 3229 3230 /* 3231 * Opposite of vfree() - mark a vnode as in use. 3232 */ 3233 void 3234 vbusy(vp) 3235 struct vnode *vp; 3236 { 3237 3238 ASSERT_VI_LOCKED(vp, "vbusy"); 3239 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3240 3241 mtx_lock(&vnode_free_list_mtx); 3242 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3243 freevnodes--; 3244 mtx_unlock(&vnode_free_list_mtx); 3245 3246 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3247 } 3248 3249 /* 3250 * Initalize per-vnode helper structure to hold poll-related state. 3251 */ 3252 void 3253 v_addpollinfo(struct vnode *vp) 3254 { 3255 struct vpollinfo *vi; 3256 3257 vi = uma_zalloc(vnodepoll_zone, M_WAITOK); 3258 if (vp->v_pollinfo != NULL) { 3259 uma_zfree(vnodepoll_zone, vi); 3260 return; 3261 } 3262 vp->v_pollinfo = vi; 3263 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3264 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, 3265 &vp->v_pollinfo->vpi_lock); 3266 } 3267 3268 /* 3269 * Record a process's interest in events which might happen to 3270 * a vnode. Because poll uses the historic select-style interface 3271 * internally, this routine serves as both the ``check for any 3272 * pending events'' and the ``record my interest in future events'' 3273 * functions. (These are done together, while the lock is held, 3274 * to avoid race conditions.) 3275 */ 3276 int 3277 vn_pollrecord(vp, td, events) 3278 struct vnode *vp; 3279 struct thread *td; 3280 short events; 3281 { 3282 3283 if (vp->v_pollinfo == NULL) 3284 v_addpollinfo(vp); 3285 mtx_lock(&vp->v_pollinfo->vpi_lock); 3286 if (vp->v_pollinfo->vpi_revents & events) { 3287 /* 3288 * This leaves events we are not interested 3289 * in available for the other process which 3290 * which presumably had requested them 3291 * (otherwise they would never have been 3292 * recorded). 3293 */ 3294 events &= vp->v_pollinfo->vpi_revents; 3295 vp->v_pollinfo->vpi_revents &= ~events; 3296 3297 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3298 return events; 3299 } 3300 vp->v_pollinfo->vpi_events |= events; 3301 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3302 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3303 return 0; 3304 } 3305 3306 /* 3307 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3308 * it is possible for us to miss an event due to race conditions, but 3309 * that condition is expected to be rare, so for the moment it is the 3310 * preferred interface. 3311 */ 3312 void 3313 vn_pollevent(vp, events) 3314 struct vnode *vp; 3315 short events; 3316 { 3317 3318 if (vp->v_pollinfo == NULL) 3319 v_addpollinfo(vp); 3320 mtx_lock(&vp->v_pollinfo->vpi_lock); 3321 if (vp->v_pollinfo->vpi_events & events) { 3322 /* 3323 * We clear vpi_events so that we don't 3324 * call selwakeup() twice if two events are 3325 * posted before the polling process(es) is 3326 * awakened. This also ensures that we take at 3327 * most one selwakeup() if the polling process 3328 * is no longer interested. However, it does 3329 * mean that only one event can be noticed at 3330 * a time. (Perhaps we should only clear those 3331 * event bits which we note?) XXX 3332 */ 3333 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3334 vp->v_pollinfo->vpi_revents |= events; 3335 selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); 3336 } 3337 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3338 } 3339 3340 /* 3341 * Wake up anyone polling on vp because it is being revoked. 3342 * This depends on dead_poll() returning POLLHUP for correct 3343 * behavior. 3344 */ 3345 void 3346 vn_pollgone(vp) 3347 struct vnode *vp; 3348 { 3349 3350 mtx_lock(&vp->v_pollinfo->vpi_lock); 3351 VN_KNOTE_LOCKED(vp, NOTE_REVOKE); 3352 if (vp->v_pollinfo->vpi_events) { 3353 vp->v_pollinfo->vpi_events = 0; 3354 selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); 3355 } 3356 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3357 } 3358 3359 3360 3361 /* 3362 * Routine to create and manage a filesystem syncer vnode. 3363 */ 3364 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3365 static int sync_fsync(struct vop_fsync_args *); 3366 static int sync_inactive(struct vop_inactive_args *); 3367 static int sync_reclaim(struct vop_reclaim_args *); 3368 3369 static vop_t **sync_vnodeop_p; 3370 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3371 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3372 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3373 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3374 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3375 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3376 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3377 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3378 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3379 { NULL, NULL } 3380 }; 3381 static struct vnodeopv_desc sync_vnodeop_opv_desc = 3382 { &sync_vnodeop_p, sync_vnodeop_entries }; 3383 3384 VNODEOP_SET(sync_vnodeop_opv_desc); 3385 3386 /* 3387 * Create a new filesystem syncer vnode for the specified mount point. 3388 */ 3389 int 3390 vfs_allocate_syncvnode(mp) 3391 struct mount *mp; 3392 { 3393 struct vnode *vp; 3394 static long start, incr, next; 3395 int error; 3396 3397 /* Allocate a new vnode */ 3398 if ((error = getnewvnode("syncer", mp, sync_vnodeop_p, &vp)) != 0) { 3399 mp->mnt_syncer = NULL; 3400 return (error); 3401 } 3402 vp->v_type = VNON; 3403 /* 3404 * Place the vnode onto the syncer worklist. We attempt to 3405 * scatter them about on the list so that they will go off 3406 * at evenly distributed times even if all the filesystems 3407 * are mounted at once. 3408 */ 3409 next += incr; 3410 if (next == 0 || next > syncer_maxdelay) { 3411 start /= 2; 3412 incr /= 2; 3413 if (start == 0) { 3414 start = syncer_maxdelay / 2; 3415 incr = syncer_maxdelay; 3416 } 3417 next = start; 3418 } 3419 VI_LOCK(vp); 3420 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 3421 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 3422 mtx_lock(&sync_mtx); 3423 sync_vnode_count++; 3424 mtx_unlock(&sync_mtx); 3425 VI_UNLOCK(vp); 3426 mp->mnt_syncer = vp; 3427 return (0); 3428 } 3429 3430 /* 3431 * Do a lazy sync of the filesystem. 3432 */ 3433 static int 3434 sync_fsync(ap) 3435 struct vop_fsync_args /* { 3436 struct vnode *a_vp; 3437 struct ucred *a_cred; 3438 int a_waitfor; 3439 struct thread *a_td; 3440 } */ *ap; 3441 { 3442 struct vnode *syncvp = ap->a_vp; 3443 struct mount *mp = syncvp->v_mount; 3444 struct thread *td = ap->a_td; 3445 int error, asyncflag; 3446 3447 /* 3448 * We only need to do something if this is a lazy evaluation. 3449 */ 3450 if (ap->a_waitfor != MNT_LAZY) 3451 return (0); 3452 3453 /* 3454 * Move ourselves to the back of the sync list. 3455 */ 3456 VI_LOCK(syncvp); 3457 vn_syncer_add_to_worklist(syncvp, syncdelay); 3458 VI_UNLOCK(syncvp); 3459 3460 /* 3461 * Walk the list of vnodes pushing all that are dirty and 3462 * not already on the sync list. 3463 */ 3464 mtx_lock(&mountlist_mtx); 3465 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3466 mtx_unlock(&mountlist_mtx); 3467 return (0); 3468 } 3469 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3470 vfs_unbusy(mp, td); 3471 return (0); 3472 } 3473 asyncflag = mp->mnt_flag & MNT_ASYNC; 3474 mp->mnt_flag &= ~MNT_ASYNC; 3475 vfs_msync(mp, MNT_NOWAIT); 3476 error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3477 if (asyncflag) 3478 mp->mnt_flag |= MNT_ASYNC; 3479 vn_finished_write(mp); 3480 vfs_unbusy(mp, td); 3481 return (error); 3482 } 3483 3484 /* 3485 * The syncer vnode is no referenced. 3486 */ 3487 static int 3488 sync_inactive(ap) 3489 struct vop_inactive_args /* { 3490 struct vnode *a_vp; 3491 struct thread *a_td; 3492 } */ *ap; 3493 { 3494 3495 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3496 vgone(ap->a_vp); 3497 return (0); 3498 } 3499 3500 /* 3501 * The syncer vnode is no longer needed and is being decommissioned. 3502 * 3503 * Modifications to the worklist must be protected by sync_mtx. 3504 */ 3505 static int 3506 sync_reclaim(ap) 3507 struct vop_reclaim_args /* { 3508 struct vnode *a_vp; 3509 } */ *ap; 3510 { 3511 struct vnode *vp = ap->a_vp; 3512 3513 VI_LOCK(vp); 3514 vp->v_mount->mnt_syncer = NULL; 3515 if (vp->v_iflag & VI_ONWORKLST) { 3516 mtx_lock(&sync_mtx); 3517 LIST_REMOVE(vp, v_synclist); 3518 syncer_worklist_len--; 3519 sync_vnode_count--; 3520 mtx_unlock(&sync_mtx); 3521 vp->v_iflag &= ~VI_ONWORKLST; 3522 } 3523 VI_UNLOCK(vp); 3524 3525 return (0); 3526 } 3527 3528 /* 3529 * extract the struct cdev *from a VCHR 3530 */ 3531 struct cdev * 3532 vn_todev(vp) 3533 struct vnode *vp; 3534 { 3535 3536 if (vp->v_type != VCHR) 3537 return (NULL); 3538 return (vp->v_rdev); 3539 } 3540 3541 /* 3542 * Check if vnode represents a disk device 3543 */ 3544 int 3545 vn_isdisk(vp, errp) 3546 struct vnode *vp; 3547 int *errp; 3548 { 3549 int error; 3550 3551 error = 0; 3552 if (vp->v_type != VCHR) 3553 error = ENOTBLK; 3554 else if (vp->v_rdev == NULL) 3555 error = ENXIO; 3556 else if (!(devsw(vp->v_rdev)->d_flags & D_DISK)) 3557 error = ENOTBLK; 3558 if (errp != NULL) 3559 *errp = error; 3560 return (error == 0); 3561 } 3562 3563 /* 3564 * Free data allocated by namei(); see namei(9) for details. 3565 */ 3566 void 3567 NDFREE(ndp, flags) 3568 struct nameidata *ndp; 3569 const u_int flags; 3570 { 3571 3572 if (!(flags & NDF_NO_FREE_PNBUF) && 3573 (ndp->ni_cnd.cn_flags & HASBUF)) { 3574 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3575 ndp->ni_cnd.cn_flags &= ~HASBUF; 3576 } 3577 if (!(flags & NDF_NO_DVP_UNLOCK) && 3578 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3579 ndp->ni_dvp != ndp->ni_vp) 3580 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3581 if (!(flags & NDF_NO_DVP_RELE) && 3582 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3583 vrele(ndp->ni_dvp); 3584 ndp->ni_dvp = NULL; 3585 } 3586 if (!(flags & NDF_NO_VP_UNLOCK) && 3587 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3588 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3589 if (!(flags & NDF_NO_VP_RELE) && 3590 ndp->ni_vp) { 3591 vrele(ndp->ni_vp); 3592 ndp->ni_vp = NULL; 3593 } 3594 if (!(flags & NDF_NO_STARTDIR_RELE) && 3595 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3596 vrele(ndp->ni_startdir); 3597 ndp->ni_startdir = NULL; 3598 } 3599 } 3600 3601 /* 3602 * Common filesystem object access control check routine. Accepts a 3603 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3604 * and optional call-by-reference privused argument allowing vaccess() 3605 * to indicate to the caller whether privilege was used to satisfy the 3606 * request (obsoleted). Returns 0 on success, or an errno on failure. 3607 */ 3608 int 3609 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3610 enum vtype type; 3611 mode_t file_mode; 3612 uid_t file_uid; 3613 gid_t file_gid; 3614 mode_t acc_mode; 3615 struct ucred *cred; 3616 int *privused; 3617 { 3618 mode_t dac_granted; 3619 #ifdef CAPABILITIES 3620 mode_t cap_granted; 3621 #endif 3622 3623 /* 3624 * Look for a normal, non-privileged way to access the file/directory 3625 * as requested. If it exists, go with that. 3626 */ 3627 3628 if (privused != NULL) 3629 *privused = 0; 3630 3631 dac_granted = 0; 3632 3633 /* Check the owner. */ 3634 if (cred->cr_uid == file_uid) { 3635 dac_granted |= VADMIN; 3636 if (file_mode & S_IXUSR) 3637 dac_granted |= VEXEC; 3638 if (file_mode & S_IRUSR) 3639 dac_granted |= VREAD; 3640 if (file_mode & S_IWUSR) 3641 dac_granted |= (VWRITE | VAPPEND); 3642 3643 if ((acc_mode & dac_granted) == acc_mode) 3644 return (0); 3645 3646 goto privcheck; 3647 } 3648 3649 /* Otherwise, check the groups (first match) */ 3650 if (groupmember(file_gid, cred)) { 3651 if (file_mode & S_IXGRP) 3652 dac_granted |= VEXEC; 3653 if (file_mode & S_IRGRP) 3654 dac_granted |= VREAD; 3655 if (file_mode & S_IWGRP) 3656 dac_granted |= (VWRITE | VAPPEND); 3657 3658 if ((acc_mode & dac_granted) == acc_mode) 3659 return (0); 3660 3661 goto privcheck; 3662 } 3663 3664 /* Otherwise, check everyone else. */ 3665 if (file_mode & S_IXOTH) 3666 dac_granted |= VEXEC; 3667 if (file_mode & S_IROTH) 3668 dac_granted |= VREAD; 3669 if (file_mode & S_IWOTH) 3670 dac_granted |= (VWRITE | VAPPEND); 3671 if ((acc_mode & dac_granted) == acc_mode) 3672 return (0); 3673 3674 privcheck: 3675 if (!suser_cred(cred, SUSER_ALLOWJAIL)) { 3676 /* XXX audit: privilege used */ 3677 if (privused != NULL) 3678 *privused = 1; 3679 return (0); 3680 } 3681 3682 #ifdef CAPABILITIES 3683 /* 3684 * Build a capability mask to determine if the set of capabilities 3685 * satisfies the requirements when combined with the granted mask 3686 * from above. 3687 * For each capability, if the capability is required, bitwise 3688 * or the request type onto the cap_granted mask. 3689 */ 3690 cap_granted = 0; 3691 3692 if (type == VDIR) { 3693 /* 3694 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3695 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3696 */ 3697 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3698 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) 3699 cap_granted |= VEXEC; 3700 } else { 3701 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3702 !cap_check(cred, NULL, CAP_DAC_EXECUTE, SUSER_ALLOWJAIL)) 3703 cap_granted |= VEXEC; 3704 } 3705 3706 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3707 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) 3708 cap_granted |= VREAD; 3709 3710 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3711 !cap_check(cred, NULL, CAP_DAC_WRITE, SUSER_ALLOWJAIL)) 3712 cap_granted |= (VWRITE | VAPPEND); 3713 3714 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3715 !cap_check(cred, NULL, CAP_FOWNER, SUSER_ALLOWJAIL)) 3716 cap_granted |= VADMIN; 3717 3718 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3719 /* XXX audit: privilege used */ 3720 if (privused != NULL) 3721 *privused = 1; 3722 return (0); 3723 } 3724 #endif 3725 3726 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3727 } 3728 3729 /* 3730 * Credential check based on process requesting service, and per-attribute 3731 * permissions. 3732 */ 3733 int 3734 extattr_check_cred(struct vnode *vp, int attrnamespace, 3735 struct ucred *cred, struct thread *td, int access) 3736 { 3737 3738 /* 3739 * Kernel-invoked always succeeds. 3740 */ 3741 if (cred == NOCRED) 3742 return (0); 3743 3744 /* 3745 * Do not allow privileged processes in jail to directly 3746 * manipulate system attributes. 3747 * 3748 * XXX What capability should apply here? 3749 * Probably CAP_SYS_SETFFLAG. 3750 */ 3751 switch (attrnamespace) { 3752 case EXTATTR_NAMESPACE_SYSTEM: 3753 /* Potentially should be: return (EPERM); */ 3754 return (suser_cred(cred, 0)); 3755 case EXTATTR_NAMESPACE_USER: 3756 return (VOP_ACCESS(vp, access, cred, td)); 3757 default: 3758 return (EPERM); 3759 } 3760 } 3761 3762 #ifdef DEBUG_VFS_LOCKS 3763 /* 3764 * This only exists to supress warnings from unlocked specfs accesses. It is 3765 * no longer ok to have an unlocked VFS. 3766 */ 3767 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 3768 3769 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3770 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, ""); 3771 3772 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3773 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, ""); 3774 3775 int vfs_badlock_print = 1; /* Print lock violations. */ 3776 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, ""); 3777 3778 #ifdef KDB 3779 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 3780 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, ""); 3781 #endif 3782 3783 static void 3784 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3785 { 3786 3787 #ifdef KDB 3788 if (vfs_badlock_backtrace) 3789 kdb_backtrace(); 3790 #endif 3791 if (vfs_badlock_print) 3792 printf("%s: %p %s\n", str, (void *)vp, msg); 3793 if (vfs_badlock_ddb) 3794 kdb_enter("lock violation"); 3795 } 3796 3797 void 3798 assert_vi_locked(struct vnode *vp, const char *str) 3799 { 3800 3801 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3802 vfs_badlock("interlock is not locked but should be", str, vp); 3803 } 3804 3805 void 3806 assert_vi_unlocked(struct vnode *vp, const char *str) 3807 { 3808 3809 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3810 vfs_badlock("interlock is locked but should not be", str, vp); 3811 } 3812 3813 void 3814 assert_vop_locked(struct vnode *vp, const char *str) 3815 { 3816 3817 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0) 3818 vfs_badlock("is not locked but should be", str, vp); 3819 } 3820 3821 void 3822 assert_vop_unlocked(struct vnode *vp, const char *str) 3823 { 3824 3825 if (vp && !IGNORE_LOCK(vp) && 3826 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 3827 vfs_badlock("is locked but should not be", str, vp); 3828 } 3829 3830 #if 0 3831 void 3832 assert_vop_elocked(struct vnode *vp, const char *str) 3833 { 3834 3835 if (vp && !IGNORE_LOCK(vp) && 3836 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 3837 vfs_badlock("is not exclusive locked but should be", str, vp); 3838 } 3839 3840 void 3841 assert_vop_elocked_other(struct vnode *vp, const char *str) 3842 { 3843 3844 if (vp && !IGNORE_LOCK(vp) && 3845 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 3846 vfs_badlock("is not exclusive locked by another thread", 3847 str, vp); 3848 } 3849 3850 void 3851 assert_vop_slocked(struct vnode *vp, const char *str) 3852 { 3853 3854 if (vp && !IGNORE_LOCK(vp) && 3855 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 3856 vfs_badlock("is not locked shared but should be", str, vp); 3857 } 3858 #endif /* 0 */ 3859 3860 void 3861 vop_rename_pre(void *ap) 3862 { 3863 struct vop_rename_args *a = ap; 3864 3865 if (a->a_tvp) 3866 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3867 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3868 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3869 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3870 3871 /* Check the source (from). */ 3872 if (a->a_tdvp != a->a_fdvp) 3873 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3874 if (a->a_tvp != a->a_fvp) 3875 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked"); 3876 3877 /* Check the target. */ 3878 if (a->a_tvp) 3879 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3880 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3881 } 3882 3883 void 3884 vop_strategy_pre(void *ap) 3885 { 3886 struct vop_strategy_args *a; 3887 struct buf *bp; 3888 3889 a = ap; 3890 bp = a->a_bp; 3891 3892 /* 3893 * Cluster ops lock their component buffers but not the IO container. 3894 */ 3895 if ((bp->b_flags & B_CLUSTER) != 0) 3896 return; 3897 3898 if (BUF_REFCNT(bp) < 1) { 3899 if (vfs_badlock_print) 3900 printf( 3901 "VOP_STRATEGY: bp is not locked but should be\n"); 3902 if (vfs_badlock_ddb) 3903 kdb_enter("lock violation"); 3904 } 3905 } 3906 3907 void 3908 vop_lookup_pre(void *ap) 3909 { 3910 struct vop_lookup_args *a; 3911 struct vnode *dvp; 3912 3913 a = ap; 3914 dvp = a->a_dvp; 3915 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3916 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3917 } 3918 3919 void 3920 vop_lookup_post(void *ap, int rc) 3921 { 3922 struct vop_lookup_args *a; 3923 struct componentname *cnp; 3924 struct vnode *dvp; 3925 struct vnode *vp; 3926 int flags; 3927 3928 a = ap; 3929 dvp = a->a_dvp; 3930 cnp = a->a_cnp; 3931 vp = *(a->a_vpp); 3932 flags = cnp->cn_flags; 3933 3934 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3935 3936 /* 3937 * If this is the last path component for this lookup and LOCKPARENT 3938 * is set, OR if there is an error the directory has to be locked. 3939 */ 3940 if ((flags & LOCKPARENT) && (flags & ISLASTCN)) 3941 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); 3942 else if (rc != 0) 3943 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); 3944 else if (dvp != vp) 3945 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); 3946 if (flags & PDIRUNLOCK) 3947 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); 3948 } 3949 3950 void 3951 vop_lock_pre(void *ap) 3952 { 3953 struct vop_lock_args *a = ap; 3954 3955 if ((a->a_flags & LK_INTERLOCK) == 0) 3956 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3957 else 3958 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3959 } 3960 3961 void 3962 vop_lock_post(void *ap, int rc) 3963 { 3964 struct vop_lock_args *a = ap; 3965 3966 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3967 if (rc == 0) 3968 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3969 } 3970 3971 void 3972 vop_unlock_pre(void *ap) 3973 { 3974 struct vop_unlock_args *a = ap; 3975 3976 if (a->a_flags & LK_INTERLOCK) 3977 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 3978 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 3979 } 3980 3981 void 3982 vop_unlock_post(void *ap, int rc) 3983 { 3984 struct vop_unlock_args *a = ap; 3985 3986 if (a->a_flags & LK_INTERLOCK) 3987 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 3988 } 3989 #endif /* DEBUG_VFS_LOCKS */ 3990 3991 static struct knlist fs_knlist; 3992 3993 static void 3994 vfs_event_init(void *arg) 3995 { 3996 knlist_init(&fs_knlist, NULL); 3997 } 3998 /* XXX - correct order? */ 3999 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 4000 4001 void 4002 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused) 4003 { 4004 4005 KNOTE_UNLOCKED(&fs_knlist, event); 4006 } 4007 4008 static int filt_fsattach(struct knote *kn); 4009 static void filt_fsdetach(struct knote *kn); 4010 static int filt_fsevent(struct knote *kn, long hint); 4011 4012 struct filterops fs_filtops = 4013 { 0, filt_fsattach, filt_fsdetach, filt_fsevent }; 4014 4015 static int 4016 filt_fsattach(struct knote *kn) 4017 { 4018 4019 kn->kn_flags |= EV_CLEAR; 4020 knlist_add(&fs_knlist, kn, 0); 4021 return (0); 4022 } 4023 4024 static void 4025 filt_fsdetach(struct knote *kn) 4026 { 4027 4028 knlist_remove(&fs_knlist, kn, 0); 4029 } 4030 4031 static int 4032 filt_fsevent(struct knote *kn, long hint) 4033 { 4034 4035 kn->kn_fflags |= hint; 4036 return (kn->kn_fflags != 0); 4037 } 4038 4039 static int 4040 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 4041 { 4042 struct vfsidctl vc; 4043 int error; 4044 struct mount *mp; 4045 4046 error = SYSCTL_IN(req, &vc, sizeof(vc)); 4047 if (error) 4048 return (error); 4049 if (vc.vc_vers != VFS_CTL_VERS1) 4050 return (EINVAL); 4051 mp = vfs_getvfs(&vc.vc_fsid); 4052 if (mp == NULL) 4053 return (ENOENT); 4054 /* ensure that a specific sysctl goes to the right filesystem. */ 4055 if (strcmp(vc.vc_fstypename, "*") != 0 && 4056 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 4057 return (EINVAL); 4058 } 4059 VCTLTOREQ(&vc, req); 4060 return (VFS_SYSCTL(mp, vc.vc_op, req)); 4061 } 4062 4063 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, 4064 NULL, 0, sysctl_vfs_ctl, "", "Sysctl by fsid"); 4065