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