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