vfs_subr.c revision 137506
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: head/sys/kern/vfs_subr.c 137506 2004-11-10 07:17:28Z phk $"); 43 44#include "opt_ddb.h" 45#include "opt_mac.h" 46 47#include <sys/param.h> 48#include <sys/systm.h> 49#include <sys/bio.h> 50#include <sys/buf.h> 51#include <sys/conf.h> 52#include <sys/event.h> 53#include <sys/eventhandler.h> 54#include <sys/extattr.h> 55#include <sys/fcntl.h> 56#include <sys/kdb.h> 57#include <sys/kernel.h> 58#include <sys/kthread.h> 59#include <sys/mac.h> 60#include <sys/malloc.h> 61#include <sys/mount.h> 62#include <sys/namei.h> 63#include <sys/reboot.h> 64#include <sys/sleepqueue.h> 65#include <sys/stat.h> 66#include <sys/sysctl.h> 67#include <sys/syslog.h> 68#include <sys/vmmeter.h> 69#include <sys/vnode.h> 70 71#include <vm/vm.h> 72#include <vm/vm_object.h> 73#include <vm/vm_extern.h> 74#include <vm/pmap.h> 75#include <vm/vm_map.h> 76#include <vm/vm_page.h> 77#include <vm/vm_kern.h> 78#include <vm/uma.h> 79 80static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 81 82static void addalias(struct vnode *vp, struct cdev *nvp_rdev); 83static void delmntque(struct vnode *vp); 84static void insmntque(struct vnode *vp, struct mount *mp); 85static void vclean(struct vnode *vp, int flags, struct thread *td); 86static void vlruvp(struct vnode *vp); 87static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, 88 int slpflag, int slptimeo, int *errorp); 89static void syncer_shutdown(void *arg, int howto); 90static int vtryrecycle(struct vnode *vp); 91static void vx_lock(struct vnode *vp); 92static void vx_unlock(struct vnode *vp); 93static void vgonechrl(struct vnode *vp, struct thread *td); 94 95 96/* 97 * Number of vnodes in existence. Increased whenever getnewvnode() 98 * allocates a new vnode, never decreased. 99 */ 100static unsigned long numvnodes; 101 102SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 103 104/* 105 * Conversion tables for conversion from vnode types to inode formats 106 * and back. 107 */ 108enum vtype iftovt_tab[16] = { 109 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 110 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 111}; 112int vttoif_tab[9] = { 113 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 114 S_IFSOCK, S_IFIFO, S_IFMT, 115}; 116 117/* 118 * List of vnodes that are ready for recycling. 119 */ 120static TAILQ_HEAD(freelst, vnode) vnode_free_list; 121 122/* 123 * Minimum number of free vnodes. If there are fewer than this free vnodes, 124 * getnewvnode() will return a newly allocated vnode. 125 */ 126static u_long wantfreevnodes = 25; 127SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 128/* Number of vnodes in the free list. */ 129static u_long freevnodes; 130SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 131 132/* 133 * Various variables used for debugging the new implementation of 134 * reassignbuf(). 135 * XXX these are probably of (very) limited utility now. 136 */ 137static int reassignbufcalls; 138SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 139static int nameileafonly; 140SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 141 142/* 143 * Cache for the mount type id assigned to NFS. This is used for 144 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 145 */ 146int nfs_mount_type = -1; 147 148/* To keep more than one thread at a time from running vfs_getnewfsid */ 149static struct mtx mntid_mtx; 150 151/* 152 * Lock for any access to the following: 153 * vnode_free_list 154 * numvnodes 155 * freevnodes 156 */ 157static struct mtx vnode_free_list_mtx; 158 159/* Publicly exported FS */ 160struct nfs_public nfs_pub; 161 162/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 163static uma_zone_t vnode_zone; 164static uma_zone_t vnodepoll_zone; 165 166/* Set to 1 to print out reclaim of active vnodes */ 167int prtactive; 168 169/* 170 * The workitem queue. 171 * 172 * It is useful to delay writes of file data and filesystem metadata 173 * for tens of seconds so that quickly created and deleted files need 174 * not waste disk bandwidth being created and removed. To realize this, 175 * we append vnodes to a "workitem" queue. When running with a soft 176 * updates implementation, most pending metadata dependencies should 177 * not wait for more than a few seconds. Thus, mounted on block devices 178 * are delayed only about a half the time that file data is delayed. 179 * Similarly, directory updates are more critical, so are only delayed 180 * about a third the time that file data is delayed. Thus, there are 181 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 182 * one each second (driven off the filesystem syncer process). The 183 * syncer_delayno variable indicates the next queue that is to be processed. 184 * Items that need to be processed soon are placed in this queue: 185 * 186 * syncer_workitem_pending[syncer_delayno] 187 * 188 * A delay of fifteen seconds is done by placing the request fifteen 189 * entries later in the queue: 190 * 191 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 192 * 193 */ 194static int syncer_delayno; 195static long syncer_mask; 196LIST_HEAD(synclist, bufobj); 197static struct synclist *syncer_workitem_pending; 198/* 199 * The sync_mtx protects: 200 * bo->bo_synclist 201 * sync_vnode_count 202 * syncer_delayno 203 * syncer_state 204 * syncer_workitem_pending 205 * syncer_worklist_len 206 * rushjob 207 */ 208static struct mtx sync_mtx; 209 210#define SYNCER_MAXDELAY 32 211static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 212static int syncdelay = 30; /* max time to delay syncing data */ 213static int filedelay = 30; /* time to delay syncing files */ 214SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 215static int dirdelay = 29; /* time to delay syncing directories */ 216SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 217static int metadelay = 28; /* time to delay syncing metadata */ 218SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 219static int rushjob; /* number of slots to run ASAP */ 220static int stat_rush_requests; /* number of times I/O speeded up */ 221SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 222 223/* 224 * When shutting down the syncer, run it at four times normal speed. 225 */ 226#define SYNCER_SHUTDOWN_SPEEDUP 4 227static int sync_vnode_count; 228static int syncer_worklist_len; 229static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 230 syncer_state; 231 232/* 233 * Number of vnodes we want to exist at any one time. This is mostly used 234 * to size hash tables in vnode-related code. It is normally not used in 235 * getnewvnode(), as wantfreevnodes is normally nonzero.) 236 * 237 * XXX desiredvnodes is historical cruft and should not exist. 238 */ 239int desiredvnodes; 240SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 241 &desiredvnodes, 0, "Maximum number of vnodes"); 242static int minvnodes; 243SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 244 &minvnodes, 0, "Minimum number of vnodes"); 245static int vnlru_nowhere; 246SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 247 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 248 249/* Hook for calling soft updates. */ 250int (*softdep_process_worklist_hook)(struct mount *); 251 252/* 253 * Initialize the vnode management data structures. 254 */ 255#ifndef MAXVNODES_MAX 256#define MAXVNODES_MAX 100000 257#endif 258static void 259vntblinit(void *dummy __unused) 260{ 261 262 /* 263 * Desiredvnodes is a function of the physical memory size and 264 * the kernel's heap size. Specifically, desiredvnodes scales 265 * in proportion to the physical memory size until two fifths 266 * of the kernel's heap size is consumed by vnodes and vm 267 * objects. 268 */ 269 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / 270 (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); 271 if (desiredvnodes > MAXVNODES_MAX) { 272 if (bootverbose) 273 printf("Reducing kern.maxvnodes %d -> %d\n", 274 desiredvnodes, MAXVNODES_MAX); 275 desiredvnodes = MAXVNODES_MAX; 276 } 277 minvnodes = desiredvnodes / 4; 278 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 279 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 280 TAILQ_INIT(&vnode_free_list); 281 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 282 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 283 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 284 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 285 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 286 /* 287 * Initialize the filesystem syncer. 288 */ 289 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 290 &syncer_mask); 291 syncer_maxdelay = syncer_mask + 1; 292 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 293} 294SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 295 296 297/* 298 * Mark a mount point as busy. Used to synchronize access and to delay 299 * unmounting. Interlock is not released on failure. 300 */ 301int 302vfs_busy(mp, flags, interlkp, td) 303 struct mount *mp; 304 int flags; 305 struct mtx *interlkp; 306 struct thread *td; 307{ 308 int lkflags; 309 310 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 311 if (flags & LK_NOWAIT) 312 return (ENOENT); 313 mp->mnt_kern_flag |= MNTK_MWAIT; 314 /* 315 * Since all busy locks are shared except the exclusive 316 * lock granted when unmounting, the only place that a 317 * wakeup needs to be done is at the release of the 318 * exclusive lock at the end of dounmount. 319 */ 320 msleep(mp, interlkp, PVFS, "vfs_busy", 0); 321 return (ENOENT); 322 } 323 lkflags = LK_SHARED | LK_NOPAUSE; 324 if (interlkp) 325 lkflags |= LK_INTERLOCK; 326 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 327 panic("vfs_busy: unexpected lock failure"); 328 return (0); 329} 330 331/* 332 * Free a busy filesystem. 333 */ 334void 335vfs_unbusy(mp, td) 336 struct mount *mp; 337 struct thread *td; 338{ 339 340 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 341} 342 343/* 344 * Lookup a mount point by filesystem identifier. 345 */ 346struct mount * 347vfs_getvfs(fsid) 348 fsid_t *fsid; 349{ 350 register struct mount *mp; 351 352 mtx_lock(&mountlist_mtx); 353 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 354 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 355 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 356 mtx_unlock(&mountlist_mtx); 357 return (mp); 358 } 359 } 360 mtx_unlock(&mountlist_mtx); 361 return ((struct mount *) 0); 362} 363 364/* 365 * Check if a user can access priveledged mount options. 366 */ 367int 368vfs_suser(struct mount *mp, struct thread *td) 369{ 370 int error; 371 372 if ((mp->mnt_flag & MNT_USER) == 0 || 373 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 374 if ((error = suser(td)) != 0) 375 return (error); 376 } 377 return (0); 378} 379 380/* 381 * Get a new unique fsid. Try to make its val[0] unique, since this value 382 * will be used to create fake device numbers for stat(). Also try (but 383 * not so hard) make its val[0] unique mod 2^16, since some emulators only 384 * support 16-bit device numbers. We end up with unique val[0]'s for the 385 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 386 * 387 * Keep in mind that several mounts may be running in parallel. Starting 388 * the search one past where the previous search terminated is both a 389 * micro-optimization and a defense against returning the same fsid to 390 * different mounts. 391 */ 392void 393vfs_getnewfsid(mp) 394 struct mount *mp; 395{ 396 static u_int16_t mntid_base; 397 fsid_t tfsid; 398 int mtype; 399 400 mtx_lock(&mntid_mtx); 401 mtype = mp->mnt_vfc->vfc_typenum; 402 tfsid.val[1] = mtype; 403 mtype = (mtype & 0xFF) << 24; 404 for (;;) { 405 tfsid.val[0] = makedev(255, 406 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 407 mntid_base++; 408 if (vfs_getvfs(&tfsid) == NULL) 409 break; 410 } 411 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 412 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 413 mtx_unlock(&mntid_mtx); 414} 415 416/* 417 * Knob to control the precision of file timestamps: 418 * 419 * 0 = seconds only; nanoseconds zeroed. 420 * 1 = seconds and nanoseconds, accurate within 1/HZ. 421 * 2 = seconds and nanoseconds, truncated to microseconds. 422 * >=3 = seconds and nanoseconds, maximum precision. 423 */ 424enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 425 426static int timestamp_precision = TSP_SEC; 427SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 428 ×tamp_precision, 0, ""); 429 430/* 431 * Get a current timestamp. 432 */ 433void 434vfs_timestamp(tsp) 435 struct timespec *tsp; 436{ 437 struct timeval tv; 438 439 switch (timestamp_precision) { 440 case TSP_SEC: 441 tsp->tv_sec = time_second; 442 tsp->tv_nsec = 0; 443 break; 444 case TSP_HZ: 445 getnanotime(tsp); 446 break; 447 case TSP_USEC: 448 microtime(&tv); 449 TIMEVAL_TO_TIMESPEC(&tv, tsp); 450 break; 451 case TSP_NSEC: 452 default: 453 nanotime(tsp); 454 break; 455 } 456} 457 458/* 459 * Set vnode attributes to VNOVAL 460 */ 461void 462vattr_null(vap) 463 register struct vattr *vap; 464{ 465 466 vap->va_type = VNON; 467 vap->va_size = VNOVAL; 468 vap->va_bytes = VNOVAL; 469 vap->va_mode = VNOVAL; 470 vap->va_nlink = VNOVAL; 471 vap->va_uid = VNOVAL; 472 vap->va_gid = VNOVAL; 473 vap->va_fsid = VNOVAL; 474 vap->va_fileid = VNOVAL; 475 vap->va_blocksize = VNOVAL; 476 vap->va_rdev = VNOVAL; 477 vap->va_atime.tv_sec = VNOVAL; 478 vap->va_atime.tv_nsec = VNOVAL; 479 vap->va_mtime.tv_sec = VNOVAL; 480 vap->va_mtime.tv_nsec = VNOVAL; 481 vap->va_ctime.tv_sec = VNOVAL; 482 vap->va_ctime.tv_nsec = VNOVAL; 483 vap->va_birthtime.tv_sec = VNOVAL; 484 vap->va_birthtime.tv_nsec = VNOVAL; 485 vap->va_flags = VNOVAL; 486 vap->va_gen = VNOVAL; 487 vap->va_vaflags = 0; 488} 489 490/* 491 * This routine is called when we have too many vnodes. It attempts 492 * to free <count> vnodes and will potentially free vnodes that still 493 * have VM backing store (VM backing store is typically the cause 494 * of a vnode blowout so we want to do this). Therefore, this operation 495 * is not considered cheap. 496 * 497 * A number of conditions may prevent a vnode from being reclaimed. 498 * the buffer cache may have references on the vnode, a directory 499 * vnode may still have references due to the namei cache representing 500 * underlying files, or the vnode may be in active use. It is not 501 * desireable to reuse such vnodes. These conditions may cause the 502 * number of vnodes to reach some minimum value regardless of what 503 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 504 */ 505static int 506vlrureclaim(struct mount *mp) 507{ 508 struct vnode *vp; 509 int done; 510 int trigger; 511 int usevnodes; 512 int count; 513 514 /* 515 * Calculate the trigger point, don't allow user 516 * screwups to blow us up. This prevents us from 517 * recycling vnodes with lots of resident pages. We 518 * aren't trying to free memory, we are trying to 519 * free vnodes. 520 */ 521 usevnodes = desiredvnodes; 522 if (usevnodes <= 0) 523 usevnodes = 1; 524 trigger = cnt.v_page_count * 2 / usevnodes; 525 526 done = 0; 527 MNT_ILOCK(mp); 528 count = mp->mnt_nvnodelistsize / 10 + 1; 529 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 530 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 531 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 532 533 if (vp->v_type != VNON && 534 vp->v_type != VBAD && 535 VI_TRYLOCK(vp)) { 536 if (VMIGHTFREE(vp) && /* critical path opt */ 537 (vp->v_object == NULL || 538 vp->v_object->resident_page_count < trigger)) { 539 MNT_IUNLOCK(mp); 540 vgonel(vp, curthread); 541 done++; 542 MNT_ILOCK(mp); 543 } else 544 VI_UNLOCK(vp); 545 } 546 --count; 547 } 548 MNT_IUNLOCK(mp); 549 return done; 550} 551 552/* 553 * Attempt to recycle vnodes in a context that is always safe to block. 554 * Calling vlrurecycle() from the bowels of filesystem code has some 555 * interesting deadlock problems. 556 */ 557static struct proc *vnlruproc; 558static int vnlruproc_sig; 559 560static void 561vnlru_proc(void) 562{ 563 struct mount *mp, *nmp; 564 int done; 565 struct proc *p = vnlruproc; 566 struct thread *td = FIRST_THREAD_IN_PROC(p); 567 568 mtx_lock(&Giant); 569 570 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 571 SHUTDOWN_PRI_FIRST); 572 573 for (;;) { 574 kthread_suspend_check(p); 575 mtx_lock(&vnode_free_list_mtx); 576 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 577 mtx_unlock(&vnode_free_list_mtx); 578 vnlruproc_sig = 0; 579 wakeup(&vnlruproc_sig); 580 tsleep(vnlruproc, PVFS, "vlruwt", hz); 581 continue; 582 } 583 mtx_unlock(&vnode_free_list_mtx); 584 done = 0; 585 mtx_lock(&mountlist_mtx); 586 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 587 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 588 nmp = TAILQ_NEXT(mp, mnt_list); 589 continue; 590 } 591 done += vlrureclaim(mp); 592 mtx_lock(&mountlist_mtx); 593 nmp = TAILQ_NEXT(mp, mnt_list); 594 vfs_unbusy(mp, td); 595 } 596 mtx_unlock(&mountlist_mtx); 597 if (done == 0) { 598#if 0 599 /* These messages are temporary debugging aids */ 600 if (vnlru_nowhere < 5) 601 printf("vnlru process getting nowhere..\n"); 602 else if (vnlru_nowhere == 5) 603 printf("vnlru process messages stopped.\n"); 604#endif 605 vnlru_nowhere++; 606 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 607 } 608 } 609} 610 611static struct kproc_desc vnlru_kp = { 612 "vnlru", 613 vnlru_proc, 614 &vnlruproc 615}; 616SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 617 618 619/* 620 * Routines having to do with the management of the vnode table. 621 */ 622 623/* 624 * Check to see if a free vnode can be recycled. If it can, 625 * recycle it and return it with the vnode interlock held. 626 */ 627static int 628vtryrecycle(struct vnode *vp) 629{ 630 struct thread *td = curthread; 631 vm_object_t object; 632 struct mount *vnmp; 633 int error; 634 635 /* Don't recycle if we can't get the interlock */ 636 if (!VI_TRYLOCK(vp)) 637 return (EWOULDBLOCK); 638 /* 639 * This vnode may found and locked via some other list, if so we 640 * can't recycle it yet. 641 */ 642 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 643 return (EWOULDBLOCK); 644 /* 645 * Don't recycle if its filesystem is being suspended. 646 */ 647 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 648 VOP_UNLOCK(vp, 0, td); 649 return (EBUSY); 650 } 651 652 /* 653 * Don't recycle if we still have cached pages. 654 */ 655 if (VOP_GETVOBJECT(vp, &object) == 0) { 656 VM_OBJECT_LOCK(object); 657 if (object->resident_page_count || 658 object->ref_count) { 659 VM_OBJECT_UNLOCK(object); 660 error = EBUSY; 661 goto done; 662 } 663 VM_OBJECT_UNLOCK(object); 664 } 665 if (LIST_FIRST(&vp->v_cache_src)) { 666 /* 667 * note: nameileafonly sysctl is temporary, 668 * for debugging only, and will eventually be 669 * removed. 670 */ 671 if (nameileafonly > 0) { 672 /* 673 * Do not reuse namei-cached directory 674 * vnodes that have cached 675 * subdirectories. 676 */ 677 if (cache_leaf_test(vp) < 0) { 678 error = EISDIR; 679 goto done; 680 } 681 } else if (nameileafonly < 0 || 682 vmiodirenable == 0) { 683 /* 684 * Do not reuse namei-cached directory 685 * vnodes if nameileafonly is -1 or 686 * if VMIO backing for directories is 687 * turned off (otherwise we reuse them 688 * too quickly). 689 */ 690 error = EBUSY; 691 goto done; 692 } 693 } 694 /* 695 * If we got this far, we need to acquire the interlock and see if 696 * anyone picked up this vnode from another list. If not, we will 697 * mark it with XLOCK via vgonel() so that anyone who does find it 698 * will skip over it. 699 */ 700 VI_LOCK(vp); 701 if (VSHOULDBUSY(vp) && (vp->v_iflag & VI_XLOCK) == 0) { 702 VI_UNLOCK(vp); 703 error = EBUSY; 704 goto done; 705 } 706 mtx_lock(&vnode_free_list_mtx); 707 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 708 vp->v_iflag &= ~VI_FREE; 709 mtx_unlock(&vnode_free_list_mtx); 710 vp->v_iflag |= VI_DOOMED; 711 if ((vp->v_type != VBAD) || (vp->v_data != NULL)) { 712 VOP_UNLOCK(vp, 0, td); 713 vgonel(vp, td); 714 VI_LOCK(vp); 715 } else 716 VOP_UNLOCK(vp, 0, td); 717 vn_finished_write(vnmp); 718 return (0); 719done: 720 VOP_UNLOCK(vp, 0, td); 721 vn_finished_write(vnmp); 722 return (error); 723} 724 725/* 726 * Return the next vnode from the free list. 727 */ 728int 729getnewvnode(tag, mp, vops, vpp) 730 const char *tag; 731 struct mount *mp; 732 vop_t **vops; 733 struct vnode **vpp; 734{ 735 struct vnode *vp = NULL; 736 struct vpollinfo *pollinfo = NULL; 737 struct bufobj *bo; 738 739 mtx_lock(&vnode_free_list_mtx); 740 741 /* 742 * Try to reuse vnodes if we hit the max. This situation only 743 * occurs in certain large-memory (2G+) situations. We cannot 744 * attempt to directly reclaim vnodes due to nasty recursion 745 * problems. 746 */ 747 while (numvnodes - freevnodes > desiredvnodes) { 748 if (vnlruproc_sig == 0) { 749 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 750 wakeup(vnlruproc); 751 } 752 mtx_unlock(&vnode_free_list_mtx); 753 tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); 754 mtx_lock(&vnode_free_list_mtx); 755 } 756 757 /* 758 * Attempt to reuse a vnode already on the free list, allocating 759 * a new vnode if we can't find one or if we have not reached a 760 * good minimum for good LRU performance. 761 */ 762 763 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 764 int error; 765 int count; 766 767 for (count = 0; count < freevnodes; count++) { 768 vp = TAILQ_FIRST(&vnode_free_list); 769 770 KASSERT(vp->v_usecount == 0 && 771 (vp->v_iflag & VI_DOINGINACT) == 0, 772 ("getnewvnode: free vnode isn't")); 773 774 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 775 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 776 mtx_unlock(&vnode_free_list_mtx); 777 error = vtryrecycle(vp); 778 mtx_lock(&vnode_free_list_mtx); 779 if (error == 0) 780 break; 781 vp = NULL; 782 } 783 } 784 if (vp) { 785 freevnodes--; 786 bo = &vp->v_bufobj; 787 mtx_unlock(&vnode_free_list_mtx); 788 789#ifdef INVARIANTS 790 { 791 if (vp->v_data) 792 printf("cleaned vnode isn't, " 793 "address %p, inode %p\n", 794 vp, vp->v_data); 795 if (bo->bo_numoutput) 796 panic("Clean vnode has pending I/O's"); 797 if (vp->v_writecount != 0) 798 panic("Non-zero write count"); 799 } 800#endif 801 if ((pollinfo = vp->v_pollinfo) != NULL) { 802 /* 803 * To avoid lock order reversals, the call to 804 * uma_zfree() must be delayed until the vnode 805 * interlock is released. 806 */ 807 vp->v_pollinfo = NULL; 808 } 809#ifdef MAC 810 mac_destroy_vnode(vp); 811#endif 812 vp->v_iflag = 0; 813 vp->v_vflag = 0; 814 vp->v_lastw = 0; 815 vp->v_lasta = 0; 816 vp->v_cstart = 0; 817 vp->v_clen = 0; 818 vp->v_socket = 0; 819 lockdestroy(vp->v_vnlock); 820 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 821 KASSERT(bo->bo_clean.bv_cnt == 0, ("cleanbufcnt not 0")); 822 KASSERT(bo->bo_clean.bv_root == NULL, ("cleanblkroot not NULL")); 823 KASSERT(bo->bo_dirty.bv_cnt == 0, ("dirtybufcnt not 0")); 824 KASSERT(bo->bo_dirty.bv_root == NULL, ("dirtyblkroot not NULL")); 825 } else { 826 numvnodes++; 827 mtx_unlock(&vnode_free_list_mtx); 828 829 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 830 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 831 VI_LOCK(vp); 832 vp->v_dd = vp; 833 bo = &vp->v_bufobj; 834 bo->__bo_vnode = vp; 835 bo->bo_mtx = &vp->v_interlock; 836 vp->v_vnlock = &vp->v_lock; 837 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 838 cache_purge(vp); /* Sets up v_id. */ 839 LIST_INIT(&vp->v_cache_src); 840 TAILQ_INIT(&vp->v_cache_dst); 841 } 842 843 TAILQ_INIT(&bo->bo_clean.bv_hd); 844 TAILQ_INIT(&bo->bo_dirty.bv_hd); 845 bo->bo_ops = &buf_ops_bio; 846 bo->bo_private = vp; 847 vp->v_type = VNON; 848 vp->v_tag = tag; 849 vp->v_op = vops; 850 *vpp = vp; 851 vp->v_usecount = 1; 852 vp->v_data = 0; 853 vp->v_cachedid = -1; 854 VI_UNLOCK(vp); 855 if (pollinfo != NULL) { 856 knlist_destroy(&pollinfo->vpi_selinfo.si_note); 857 mtx_destroy(&pollinfo->vpi_lock); 858 uma_zfree(vnodepoll_zone, pollinfo); 859 } 860#ifdef MAC 861 mac_init_vnode(vp); 862 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 863 mac_associate_vnode_singlelabel(mp, vp); 864 else if (mp == NULL) 865 printf("NULL mp in getnewvnode()\n"); 866#endif 867 delmntque(vp); 868 if (mp != NULL) { 869 insmntque(vp, mp); 870 bo->bo_bsize = mp->mnt_stat.f_iosize; 871 } 872 873 return (0); 874} 875 876/* 877 * Delete from old mount point vnode list, if on one. 878 */ 879static void 880delmntque(struct vnode *vp) 881{ 882 struct mount *mp; 883 884 if (vp->v_mount == NULL) 885 return; 886 mp = vp->v_mount; 887 MNT_ILOCK(mp); 888 vp->v_mount = NULL; 889 KASSERT(mp->mnt_nvnodelistsize > 0, 890 ("bad mount point vnode list size")); 891 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 892 mp->mnt_nvnodelistsize--; 893 MNT_IUNLOCK(mp); 894} 895 896/* 897 * Insert into list of vnodes for the new mount point, if available. 898 */ 899static void 900insmntque(struct vnode *vp, struct mount *mp) 901{ 902 903 vp->v_mount = mp; 904 KASSERT(mp != NULL, ("Don't call insmntque(foo, NULL)")); 905 MNT_ILOCK(vp->v_mount); 906 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 907 mp->mnt_nvnodelistsize++; 908 MNT_IUNLOCK(vp->v_mount); 909} 910 911/* 912 * Flush out and invalidate all buffers associated with a vnode. 913 * Called with the underlying object locked. 914 */ 915int 916vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 917 struct vnode *vp; 918 int flags; 919 struct ucred *cred; 920 struct thread *td; 921 int slpflag, slptimeo; 922{ 923 struct buf *blist; 924 int error; 925 vm_object_t object; 926 struct bufobj *bo; 927 928 GIANT_REQUIRED; 929 930 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 931 932 bo = &vp->v_bufobj; 933 BO_LOCK(bo); 934 if (flags & V_SAVE) { 935 error = bufobj_wwait(bo, slpflag, slptimeo); 936 if (error) { 937 VI_UNLOCK(vp); 938 return (error); 939 } 940 if (bo->bo_dirty.bv_cnt > 0) { 941 VI_UNLOCK(vp); 942 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 943 return (error); 944 /* 945 * XXX We could save a lock/unlock if this was only 946 * enabled under INVARIANTS 947 */ 948 VI_LOCK(vp); 949 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 950 panic("vinvalbuf: dirty bufs"); 951 } 952 } 953 /* 954 * If you alter this loop please notice that interlock is dropped and 955 * reacquired in flushbuflist. Special care is needed to ensure that 956 * no race conditions occur from this. 957 */ 958 for (error = 0;;) { 959 blist = TAILQ_FIRST(&vp->v_bufobj.bo_clean.bv_hd); 960 if (blist != NULL && 961 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 962 if (error) 963 break; 964 continue; 965 } 966 blist = TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd); 967 if (blist != NULL && 968 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 969 if (error) 970 break; 971 continue; 972 } 973 break; 974 } 975 if (error) { 976 VI_UNLOCK(vp); 977 return (error); 978 } 979 980 /* 981 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 982 * have write I/O in-progress but if there is a VM object then the 983 * VM object can also have read-I/O in-progress. 984 */ 985 do { 986 bufobj_wwait(bo, 0, 0); 987 VI_UNLOCK(vp); 988 if (VOP_GETVOBJECT(vp, &object) == 0) { 989 VM_OBJECT_LOCK(object); 990 vm_object_pip_wait(object, "vnvlbx"); 991 VM_OBJECT_UNLOCK(object); 992 } 993 VI_LOCK(vp); 994 } while (bo->bo_numoutput > 0); 995 VI_UNLOCK(vp); 996 997 /* 998 * Destroy the copy in the VM cache, too. 999 */ 1000 if (VOP_GETVOBJECT(vp, &object) == 0) { 1001 VM_OBJECT_LOCK(object); 1002 vm_object_page_remove(object, 0, 0, 1003 (flags & V_SAVE) ? TRUE : FALSE); 1004 VM_OBJECT_UNLOCK(object); 1005 } 1006 1007#ifdef INVARIANTS 1008 VI_LOCK(vp); 1009 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1010 (vp->v_bufobj.bo_dirty.bv_cnt > 0 || 1011 vp->v_bufobj.bo_clean.bv_cnt > 0)) 1012 panic("vinvalbuf: flush failed"); 1013 VI_UNLOCK(vp); 1014#endif 1015 return (0); 1016} 1017 1018/* 1019 * Flush out buffers on the specified list. 1020 * 1021 */ 1022static int 1023flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) 1024 struct buf *blist; 1025 int flags; 1026 struct vnode *vp; 1027 int slpflag, slptimeo; 1028 int *errorp; 1029{ 1030 struct buf *bp, *nbp; 1031 int found, error; 1032 1033 ASSERT_VI_LOCKED(vp, "flushbuflist"); 1034 1035 for (found = 0, bp = blist; bp; bp = nbp) { 1036 nbp = TAILQ_NEXT(bp, b_bobufs); 1037 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1038 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1039 continue; 1040 } 1041 found += 1; 1042 error = BUF_TIMELOCK(bp, 1043 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), 1044 "flushbuf", slpflag, slptimeo); 1045 if (error) { 1046 if (error != ENOLCK) 1047 *errorp = error; 1048 goto done; 1049 } 1050 /* 1051 * XXX Since there are no node locks for NFS, I 1052 * believe there is a slight chance that a delayed 1053 * write will occur while sleeping just above, so 1054 * check for it. Note that vfs_bio_awrite expects 1055 * buffers to reside on a queue, while bwrite and 1056 * brelse do not. 1057 */ 1058 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1059 (flags & V_SAVE)) { 1060 1061 if (bp->b_vp == vp) { 1062 if (bp->b_flags & B_CLUSTEROK) { 1063 vfs_bio_awrite(bp); 1064 } else { 1065 bremfree(bp); 1066 bp->b_flags |= B_ASYNC; 1067 bwrite(bp); 1068 } 1069 } else { 1070 bremfree(bp); 1071 (void) bwrite(bp); 1072 } 1073 goto done; 1074 } 1075 bremfree(bp); 1076 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1077 bp->b_flags &= ~B_ASYNC; 1078 brelse(bp); 1079 VI_LOCK(vp); 1080 } 1081 return (found); 1082done: 1083 VI_LOCK(vp); 1084 return (found); 1085} 1086 1087/* 1088 * Truncate a file's buffer and pages to a specified length. This 1089 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1090 * sync activity. 1091 */ 1092int 1093vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td, off_t length, int blksize) 1094{ 1095 struct buf *bp, *nbp; 1096 int anyfreed; 1097 int trunclbn; 1098 struct bufobj *bo; 1099 1100 /* 1101 * Round up to the *next* lbn. 1102 */ 1103 trunclbn = (length + blksize - 1) / blksize; 1104 1105 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1106restart: 1107 VI_LOCK(vp); 1108 bo = &vp->v_bufobj; 1109 anyfreed = 1; 1110 for (;anyfreed;) { 1111 anyfreed = 0; 1112 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1113 if (bp->b_lblkno < trunclbn) 1114 continue; 1115 if (BUF_LOCK(bp, 1116 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1117 VI_MTX(vp)) == ENOLCK) 1118 goto restart; 1119 1120 bremfree(bp); 1121 bp->b_flags |= (B_INVAL | B_RELBUF); 1122 bp->b_flags &= ~B_ASYNC; 1123 brelse(bp); 1124 anyfreed = 1; 1125 1126 if (nbp != NULL && 1127 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1128 (nbp->b_vp != vp) || 1129 (nbp->b_flags & B_DELWRI))) { 1130 goto restart; 1131 } 1132 VI_LOCK(vp); 1133 } 1134 1135 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1136 if (bp->b_lblkno < trunclbn) 1137 continue; 1138 if (BUF_LOCK(bp, 1139 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1140 VI_MTX(vp)) == ENOLCK) 1141 goto restart; 1142 bremfree(bp); 1143 bp->b_flags |= (B_INVAL | B_RELBUF); 1144 bp->b_flags &= ~B_ASYNC; 1145 brelse(bp); 1146 anyfreed = 1; 1147 if (nbp != NULL && 1148 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1149 (nbp->b_vp != vp) || 1150 (nbp->b_flags & B_DELWRI) == 0)) { 1151 goto restart; 1152 } 1153 VI_LOCK(vp); 1154 } 1155 } 1156 1157 if (length > 0) { 1158restartsync: 1159 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1160 if (bp->b_lblkno > 0) 1161 continue; 1162 /* 1163 * Since we hold the vnode lock this should only 1164 * fail if we're racing with the buf daemon. 1165 */ 1166 if (BUF_LOCK(bp, 1167 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1168 VI_MTX(vp)) == ENOLCK) { 1169 goto restart; 1170 } 1171 KASSERT((bp->b_flags & B_DELWRI), 1172 ("buf(%p) on dirty queue without DELWRI", bp)); 1173 1174 bremfree(bp); 1175 bawrite(bp); 1176 VI_LOCK(vp); 1177 goto restartsync; 1178 } 1179 } 1180 1181 bufobj_wwait(bo, 0, 0); 1182 VI_UNLOCK(vp); 1183 vnode_pager_setsize(vp, length); 1184 1185 return (0); 1186} 1187 1188/* 1189 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1190 * a vnode. 1191 * 1192 * NOTE: We have to deal with the special case of a background bitmap 1193 * buffer, a situation where two buffers will have the same logical 1194 * block offset. We want (1) only the foreground buffer to be accessed 1195 * in a lookup and (2) must differentiate between the foreground and 1196 * background buffer in the splay tree algorithm because the splay 1197 * tree cannot normally handle multiple entities with the same 'index'. 1198 * We accomplish this by adding differentiating flags to the splay tree's 1199 * numerical domain. 1200 */ 1201static 1202struct buf * 1203buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1204{ 1205 struct buf dummy; 1206 struct buf *lefttreemax, *righttreemin, *y; 1207 1208 if (root == NULL) 1209 return (NULL); 1210 lefttreemax = righttreemin = &dummy; 1211 for (;;) { 1212 if (lblkno < root->b_lblkno || 1213 (lblkno == root->b_lblkno && 1214 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1215 if ((y = root->b_left) == NULL) 1216 break; 1217 if (lblkno < y->b_lblkno) { 1218 /* Rotate right. */ 1219 root->b_left = y->b_right; 1220 y->b_right = root; 1221 root = y; 1222 if ((y = root->b_left) == NULL) 1223 break; 1224 } 1225 /* Link into the new root's right tree. */ 1226 righttreemin->b_left = root; 1227 righttreemin = root; 1228 } else if (lblkno > root->b_lblkno || 1229 (lblkno == root->b_lblkno && 1230 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1231 if ((y = root->b_right) == NULL) 1232 break; 1233 if (lblkno > y->b_lblkno) { 1234 /* Rotate left. */ 1235 root->b_right = y->b_left; 1236 y->b_left = root; 1237 root = y; 1238 if ((y = root->b_right) == NULL) 1239 break; 1240 } 1241 /* Link into the new root's left tree. */ 1242 lefttreemax->b_right = root; 1243 lefttreemax = root; 1244 } else { 1245 break; 1246 } 1247 root = y; 1248 } 1249 /* Assemble the new root. */ 1250 lefttreemax->b_right = root->b_left; 1251 righttreemin->b_left = root->b_right; 1252 root->b_left = dummy.b_right; 1253 root->b_right = dummy.b_left; 1254 return (root); 1255} 1256 1257static void 1258buf_vlist_remove(struct buf *bp) 1259{ 1260 struct buf *root; 1261 struct bufv *bv; 1262 1263 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1264 ASSERT_BO_LOCKED(bp->b_bufobj); 1265 if (bp->b_xflags & BX_VNDIRTY) 1266 bv = &bp->b_bufobj->bo_dirty; 1267 else 1268 bv = &bp->b_bufobj->bo_clean; 1269 if (bp != bv->bv_root) { 1270 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1271 KASSERT(root == bp, ("splay lookup failed in remove")); 1272 } 1273 if (bp->b_left == NULL) { 1274 root = bp->b_right; 1275 } else { 1276 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1277 root->b_right = bp->b_right; 1278 } 1279 bv->bv_root = root; 1280 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1281 bv->bv_cnt--; 1282 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1283} 1284 1285/* 1286 * Add the buffer to the sorted clean or dirty block list using a 1287 * splay tree algorithm. 1288 * 1289 * NOTE: xflags is passed as a constant, optimizing this inline function! 1290 */ 1291static void 1292buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1293{ 1294 struct buf *root; 1295 struct bufv *bv; 1296 1297 ASSERT_BO_LOCKED(bo); 1298 bp->b_xflags |= xflags; 1299 if (xflags & BX_VNDIRTY) 1300 bv = &bo->bo_dirty; 1301 else 1302 bv = &bo->bo_clean; 1303 1304 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1305 if (root == NULL) { 1306 bp->b_left = NULL; 1307 bp->b_right = NULL; 1308 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1309 } else if (bp->b_lblkno < root->b_lblkno || 1310 (bp->b_lblkno == root->b_lblkno && 1311 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1312 bp->b_left = root->b_left; 1313 bp->b_right = root; 1314 root->b_left = NULL; 1315 TAILQ_INSERT_BEFORE(root, bp, b_bobufs); 1316 } else { 1317 bp->b_right = root->b_right; 1318 bp->b_left = root; 1319 root->b_right = NULL; 1320 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs); 1321 } 1322 bv->bv_cnt++; 1323 bv->bv_root = bp; 1324} 1325 1326/* 1327 * Lookup a buffer using the splay tree. Note that we specifically avoid 1328 * shadow buffers used in background bitmap writes. 1329 * 1330 * This code isn't quite efficient as it could be because we are maintaining 1331 * two sorted lists and do not know which list the block resides in. 1332 * 1333 * During a "make buildworld" the desired buffer is found at one of 1334 * the roots more than 60% of the time. Thus, checking both roots 1335 * before performing either splay eliminates unnecessary splays on the 1336 * first tree splayed. 1337 */ 1338struct buf * 1339gbincore(struct bufobj *bo, daddr_t lblkno) 1340{ 1341 struct buf *bp; 1342 1343 GIANT_REQUIRED; 1344 1345 ASSERT_BO_LOCKED(bo); 1346 if ((bp = bo->bo_clean.bv_root) != NULL && 1347 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1348 return (bp); 1349 if ((bp = bo->bo_dirty.bv_root) != NULL && 1350 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1351 return (bp); 1352 if ((bp = bo->bo_clean.bv_root) != NULL) { 1353 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp); 1354 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1355 return (bp); 1356 } 1357 if ((bp = bo->bo_dirty.bv_root) != NULL) { 1358 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp); 1359 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1360 return (bp); 1361 } 1362 return (NULL); 1363} 1364 1365/* 1366 * Associate a buffer with a vnode. 1367 */ 1368void 1369bgetvp(struct vnode *vp, struct buf *bp) 1370{ 1371 1372 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1373 1374 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1375 ("bgetvp: bp already attached! %p", bp)); 1376 1377 ASSERT_VI_LOCKED(vp, "bgetvp"); 1378 vholdl(vp); 1379 bp->b_vp = vp; 1380 bp->b_bufobj = &vp->v_bufobj; 1381 /* 1382 * Insert onto list for new vnode. 1383 */ 1384 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN); 1385} 1386 1387/* 1388 * Disassociate a buffer from a vnode. 1389 */ 1390void 1391brelvp(struct buf *bp) 1392{ 1393 struct bufobj *bo; 1394 struct vnode *vp; 1395 1396 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1397 1398 /* 1399 * Delete from old vnode list, if on one. 1400 */ 1401 vp = bp->b_vp; /* XXX */ 1402 bo = bp->b_bufobj; 1403 BO_LOCK(bo); 1404 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1405 buf_vlist_remove(bp); 1406 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1407 bo->bo_flag &= ~BO_ONWORKLST; 1408 mtx_lock(&sync_mtx); 1409 LIST_REMOVE(bo, bo_synclist); 1410 syncer_worklist_len--; 1411 mtx_unlock(&sync_mtx); 1412 } 1413 vdropl(vp); 1414 bp->b_vp = NULL; 1415 bp->b_bufobj = NULL; 1416 BO_UNLOCK(bo); 1417} 1418 1419/* 1420 * Add an item to the syncer work queue. 1421 */ 1422static void 1423vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 1424{ 1425 int slot; 1426 1427 ASSERT_BO_LOCKED(bo); 1428 1429 mtx_lock(&sync_mtx); 1430 if (bo->bo_flag & BO_ONWORKLST) 1431 LIST_REMOVE(bo, bo_synclist); 1432 else { 1433 bo->bo_flag |= BO_ONWORKLST; 1434 syncer_worklist_len++; 1435 } 1436 1437 if (delay > syncer_maxdelay - 2) 1438 delay = syncer_maxdelay - 2; 1439 slot = (syncer_delayno + delay) & syncer_mask; 1440 1441 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 1442 mtx_unlock(&sync_mtx); 1443} 1444 1445static int 1446sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1447{ 1448 int error, len; 1449 1450 mtx_lock(&sync_mtx); 1451 len = syncer_worklist_len - sync_vnode_count; 1452 mtx_unlock(&sync_mtx); 1453 error = SYSCTL_OUT(req, &len, sizeof(len)); 1454 return (error); 1455} 1456 1457SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1458 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1459 1460struct proc *updateproc; 1461static void sched_sync(void); 1462static struct kproc_desc up_kp = { 1463 "syncer", 1464 sched_sync, 1465 &updateproc 1466}; 1467SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1468 1469/* 1470 * System filesystem synchronizer daemon. 1471 */ 1472static void 1473sched_sync(void) 1474{ 1475 struct synclist *next; 1476 struct synclist *slp; 1477 struct vnode *vp; 1478 struct bufobj *bo; 1479 struct mount *mp; 1480 long starttime; 1481 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); 1482 static int dummychan; 1483 int last_work_seen; 1484 int net_worklist_len; 1485 int syncer_final_iter; 1486 int first_printf; 1487 1488 mtx_lock(&Giant); 1489 last_work_seen = 0; 1490 syncer_final_iter = 0; 1491 first_printf = 1; 1492 syncer_state = SYNCER_RUNNING; 1493 starttime = time_second; 1494 1495 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 1496 SHUTDOWN_PRI_LAST); 1497 1498 for (;;) { 1499 mtx_lock(&sync_mtx); 1500 if (syncer_state == SYNCER_FINAL_DELAY && 1501 syncer_final_iter == 0) { 1502 mtx_unlock(&sync_mtx); 1503 kthread_suspend_check(td->td_proc); 1504 mtx_lock(&sync_mtx); 1505 } 1506 net_worklist_len = syncer_worklist_len - sync_vnode_count; 1507 if (syncer_state != SYNCER_RUNNING && 1508 starttime != time_second) { 1509 if (first_printf) { 1510 printf("\nSyncing disks, vnodes remaining..."); 1511 first_printf = 0; 1512 } 1513 printf("%d ", net_worklist_len); 1514 } 1515 starttime = time_second; 1516 1517 /* 1518 * Push files whose dirty time has expired. Be careful 1519 * of interrupt race on slp queue. 1520 * 1521 * Skip over empty worklist slots when shutting down. 1522 */ 1523 do { 1524 slp = &syncer_workitem_pending[syncer_delayno]; 1525 syncer_delayno += 1; 1526 if (syncer_delayno == syncer_maxdelay) 1527 syncer_delayno = 0; 1528 next = &syncer_workitem_pending[syncer_delayno]; 1529 /* 1530 * If the worklist has wrapped since the 1531 * it was emptied of all but syncer vnodes, 1532 * switch to the FINAL_DELAY state and run 1533 * for one more second. 1534 */ 1535 if (syncer_state == SYNCER_SHUTTING_DOWN && 1536 net_worklist_len == 0 && 1537 last_work_seen == syncer_delayno) { 1538 syncer_state = SYNCER_FINAL_DELAY; 1539 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 1540 } 1541 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 1542 syncer_worklist_len > 0); 1543 1544 /* 1545 * Keep track of the last time there was anything 1546 * on the worklist other than syncer vnodes. 1547 * Return to the SHUTTING_DOWN state if any 1548 * new work appears. 1549 */ 1550 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 1551 last_work_seen = syncer_delayno; 1552 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 1553 syncer_state = SYNCER_SHUTTING_DOWN; 1554 while ((bo = LIST_FIRST(slp)) != NULL) { 1555 vp = bo->__bo_vnode; /* XXX */ 1556 if (VOP_ISLOCKED(vp, NULL) != 0 || 1557 vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1558 LIST_REMOVE(bo, bo_synclist); 1559 LIST_INSERT_HEAD(next, bo, bo_synclist); 1560 continue; 1561 } 1562 if (VI_TRYLOCK(vp) == 0) { 1563 LIST_REMOVE(bo, bo_synclist); 1564 LIST_INSERT_HEAD(next, bo, bo_synclist); 1565 vn_finished_write(mp); 1566 continue; 1567 } 1568 /* 1569 * We use vhold in case the vnode does not 1570 * successfully sync. vhold prevents the vnode from 1571 * going away when we unlock the sync_mtx so that 1572 * we can acquire the vnode interlock. 1573 */ 1574 vholdl(vp); 1575 mtx_unlock(&sync_mtx); 1576 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td); 1577 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1578 VOP_UNLOCK(vp, 0, td); 1579 vn_finished_write(mp); 1580 VI_LOCK(vp); 1581 if ((bo->bo_flag & BO_ONWORKLST) != 0) { 1582 /* 1583 * Put us back on the worklist. The worklist 1584 * routine will remove us from our current 1585 * position and then add us back in at a later 1586 * position. 1587 */ 1588 vn_syncer_add_to_worklist(bo, syncdelay); 1589 } 1590 vdropl(vp); 1591 VI_UNLOCK(vp); 1592 mtx_lock(&sync_mtx); 1593 } 1594 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 1595 syncer_final_iter--; 1596 mtx_unlock(&sync_mtx); 1597 1598 /* 1599 * Do soft update processing. 1600 */ 1601 if (softdep_process_worklist_hook != NULL) 1602 (*softdep_process_worklist_hook)(NULL); 1603 1604 /* 1605 * The variable rushjob allows the kernel to speed up the 1606 * processing of the filesystem syncer process. A rushjob 1607 * value of N tells the filesystem syncer to process the next 1608 * N seconds worth of work on its queue ASAP. Currently rushjob 1609 * is used by the soft update code to speed up the filesystem 1610 * syncer process when the incore state is getting so far 1611 * ahead of the disk that the kernel memory pool is being 1612 * threatened with exhaustion. 1613 */ 1614 mtx_lock(&sync_mtx); 1615 if (rushjob > 0) { 1616 rushjob -= 1; 1617 mtx_unlock(&sync_mtx); 1618 continue; 1619 } 1620 mtx_unlock(&sync_mtx); 1621 /* 1622 * Just sleep for a short period if time between 1623 * iterations when shutting down to allow some I/O 1624 * to happen. 1625 * 1626 * If it has taken us less than a second to process the 1627 * current work, then wait. Otherwise start right over 1628 * again. We can still lose time if any single round 1629 * takes more than two seconds, but it does not really 1630 * matter as we are just trying to generally pace the 1631 * filesystem activity. 1632 */ 1633 if (syncer_state != SYNCER_RUNNING) 1634 tsleep(&dummychan, PPAUSE, "syncfnl", 1635 hz / SYNCER_SHUTDOWN_SPEEDUP); 1636 else if (time_second == starttime) 1637 tsleep(&lbolt, PPAUSE, "syncer", 0); 1638 } 1639} 1640 1641/* 1642 * Request the syncer daemon to speed up its work. 1643 * We never push it to speed up more than half of its 1644 * normal turn time, otherwise it could take over the cpu. 1645 */ 1646int 1647speedup_syncer() 1648{ 1649 struct thread *td; 1650 int ret = 0; 1651 1652 td = FIRST_THREAD_IN_PROC(updateproc); 1653 sleepq_remove(td, &lbolt); 1654 mtx_lock(&sync_mtx); 1655 if (rushjob < syncdelay / 2) { 1656 rushjob += 1; 1657 stat_rush_requests += 1; 1658 ret = 1; 1659 } 1660 mtx_unlock(&sync_mtx); 1661 return (ret); 1662} 1663 1664/* 1665 * Tell the syncer to speed up its work and run though its work 1666 * list several times, then tell it to shut down. 1667 */ 1668static void 1669syncer_shutdown(void *arg, int howto) 1670{ 1671 struct thread *td; 1672 1673 if (howto & RB_NOSYNC) 1674 return; 1675 td = FIRST_THREAD_IN_PROC(updateproc); 1676 sleepq_remove(td, &lbolt); 1677 mtx_lock(&sync_mtx); 1678 syncer_state = SYNCER_SHUTTING_DOWN; 1679 rushjob = 0; 1680 mtx_unlock(&sync_mtx); 1681 kproc_shutdown(arg, howto); 1682} 1683 1684/* 1685 * Associate a p-buffer with a vnode. 1686 * 1687 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1688 * with the buffer. i.e. the bp has not been linked into the vnode or 1689 * ref-counted. 1690 */ 1691void 1692pbgetvp(vp, bp) 1693 register struct vnode *vp; 1694 register struct buf *bp; 1695{ 1696 1697 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1698 1699 bp->b_vp = vp; 1700 bp->b_flags |= B_PAGING; 1701 bp->b_bufobj = &vp->v_bufobj; 1702} 1703 1704/* 1705 * Disassociate a p-buffer from a vnode. 1706 */ 1707void 1708pbrelvp(bp) 1709 register struct buf *bp; 1710{ 1711 1712 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1713 KASSERT(bp->b_bufobj != NULL, ("pbrelvp: NULL bufobj")); 1714 1715 /* XXX REMOVE ME */ 1716 BO_LOCK(bp->b_bufobj); 1717 if (TAILQ_NEXT(bp, b_bobufs) != NULL) { 1718 panic( 1719 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1720 bp, 1721 (int)bp->b_flags 1722 ); 1723 } 1724 BO_UNLOCK(bp->b_bufobj); 1725 bp->b_vp = NULL; 1726 bp->b_bufobj = NULL; 1727 bp->b_flags &= ~B_PAGING; 1728} 1729 1730/* 1731 * Reassign a buffer from one vnode to another. 1732 * Used to assign file specific control information 1733 * (indirect blocks) to the vnode to which they belong. 1734 */ 1735void 1736reassignbuf(struct buf *bp) 1737{ 1738 struct vnode *vp; 1739 struct bufobj *bo; 1740 int delay; 1741 1742 vp = bp->b_vp; 1743 bo = bp->b_bufobj; 1744 ++reassignbufcalls; 1745 1746 /* 1747 * B_PAGING flagged buffers cannot be reassigned because their vp 1748 * is not fully linked in. 1749 */ 1750 if (bp->b_flags & B_PAGING) 1751 panic("cannot reassign paging buffer"); 1752 1753 /* 1754 * Delete from old vnode list, if on one. 1755 */ 1756 VI_LOCK(vp); 1757 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1758 buf_vlist_remove(bp); 1759 /* 1760 * If dirty, put on list of dirty buffers; otherwise insert onto list 1761 * of clean buffers. 1762 */ 1763 if (bp->b_flags & B_DELWRI) { 1764 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 1765 switch (vp->v_type) { 1766 case VDIR: 1767 delay = dirdelay; 1768 break; 1769 case VCHR: 1770 delay = metadelay; 1771 break; 1772 default: 1773 delay = filedelay; 1774 } 1775 vn_syncer_add_to_worklist(bo, delay); 1776 } 1777 buf_vlist_add(bp, bo, BX_VNDIRTY); 1778 } else { 1779 buf_vlist_add(bp, bo, BX_VNCLEAN); 1780 1781 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1782 mtx_lock(&sync_mtx); 1783 LIST_REMOVE(bo, bo_synclist); 1784 syncer_worklist_len--; 1785 mtx_unlock(&sync_mtx); 1786 bo->bo_flag &= ~BO_ONWORKLST; 1787 } 1788 } 1789 VI_UNLOCK(vp); 1790} 1791 1792/* 1793 * Create a vnode for a device. 1794 * Used for mounting the root filesystem. 1795 */ 1796int 1797bdevvp(dev, vpp) 1798 struct cdev *dev; 1799 struct vnode **vpp; 1800{ 1801 register struct vnode *vp; 1802 struct vnode *nvp; 1803 int error; 1804 1805 if (dev == NULL) { 1806 *vpp = NULLVP; 1807 return (ENXIO); 1808 } 1809 if (vfinddev(dev, vpp)) 1810 return (0); 1811 1812 error = getnewvnode("none", (struct mount *)0, devfs_specop_p, &nvp); 1813 if (error) { 1814 *vpp = NULLVP; 1815 return (error); 1816 } 1817 vp = nvp; 1818 vp->v_type = VCHR; 1819 vp->v_bufobj.bo_bsize = DEV_BSIZE; 1820 addalias(vp, dev); 1821 *vpp = vp; 1822 return (0); 1823} 1824 1825static void 1826v_incr_usecount(struct vnode *vp, int delta) 1827{ 1828 1829 vp->v_usecount += delta; 1830 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1831 dev_lock(); 1832 vp->v_rdev->si_usecount += delta; 1833 dev_unlock(); 1834 } 1835} 1836 1837/* 1838 * Add vnode to the alias list hung off the struct cdev *. 1839 * 1840 * The reason for this gunk is that multiple vnodes can reference 1841 * the same physical device, so checking vp->v_usecount to see 1842 * how many users there are is inadequate; the v_usecount for 1843 * the vnodes need to be accumulated. vcount() does that. 1844 */ 1845struct vnode * 1846addaliasu(nvp, nvp_rdev) 1847 struct vnode *nvp; 1848 dev_t nvp_rdev; 1849{ 1850 struct vnode *ovp; 1851 vop_t **ops; 1852 struct cdev *dev; 1853 1854 if (nvp->v_type == VBLK) 1855 return (nvp); 1856 if (nvp->v_type != VCHR) 1857 panic("addaliasu on non-special vnode"); 1858 dev = findcdev(nvp_rdev); 1859 if (dev == NULL) 1860 return (nvp); 1861 /* 1862 * Check to see if we have a bdevvp vnode with no associated 1863 * filesystem. If so, we want to associate the filesystem of 1864 * the new newly instigated vnode with the bdevvp vnode and 1865 * discard the newly created vnode rather than leaving the 1866 * bdevvp vnode lying around with no associated filesystem. 1867 */ 1868 if (vfinddev(dev, &ovp) == 0 || ovp->v_data != NULL) { 1869 addalias(nvp, dev); 1870 return (nvp); 1871 } 1872 /* 1873 * Discard unneeded vnode, but save its node specific data. 1874 * Note that if there is a lock, it is carried over in the 1875 * node specific data to the replacement vnode. 1876 */ 1877 vref(ovp); 1878 ovp->v_data = nvp->v_data; 1879 ovp->v_tag = nvp->v_tag; 1880 nvp->v_data = NULL; 1881 lockdestroy(ovp->v_vnlock); 1882 lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, 1883 nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); 1884 ops = ovp->v_op; 1885 ovp->v_op = nvp->v_op; 1886 if (VOP_ISLOCKED(nvp, curthread)) { 1887 VOP_UNLOCK(nvp, 0, curthread); 1888 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 1889 } 1890 nvp->v_op = ops; 1891 delmntque(ovp); 1892 insmntque(ovp, nvp->v_mount); 1893 vrele(nvp); 1894 vgone(nvp); 1895 return (ovp); 1896} 1897 1898/* This is a local helper function that do the same as addaliasu, but for a 1899 * struct cdev *instead of an dev_t. */ 1900static void 1901addalias(nvp, dev) 1902 struct vnode *nvp; 1903 struct cdev *dev; 1904{ 1905 1906 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 1907 VI_LOCK(nvp); 1908 dev_lock(); 1909 dev->si_refcount++; 1910 nvp->v_rdev = dev; 1911 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 1912 dev->si_usecount += nvp->v_usecount; 1913 dev_unlock(); 1914 VI_UNLOCK(nvp); 1915} 1916 1917/* 1918 * Grab a particular vnode from the free list, increment its 1919 * reference count and lock it. The vnode lock bit is set if the 1920 * vnode is being eliminated in vgone. The process is awakened 1921 * when the transition is completed, and an error returned to 1922 * indicate that the vnode is no longer usable (possibly having 1923 * been changed to a new filesystem type). 1924 */ 1925int 1926vget(vp, flags, td) 1927 register struct vnode *vp; 1928 int flags; 1929 struct thread *td; 1930{ 1931 int error; 1932 1933 /* 1934 * If the vnode is in the process of being cleaned out for 1935 * another use, we wait for the cleaning to finish and then 1936 * return failure. Cleaning is determined by checking that 1937 * the VI_XLOCK flag is set. 1938 */ 1939 if ((flags & LK_INTERLOCK) == 0) 1940 VI_LOCK(vp); 1941 if (vp->v_iflag & VI_XLOCK && vp->v_vxthread != curthread) { 1942 if ((flags & LK_NOWAIT) == 0) { 1943 vp->v_iflag |= VI_XWANT; 1944 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); 1945 return (ENOENT); 1946 } 1947 VI_UNLOCK(vp); 1948 return (EBUSY); 1949 } 1950 1951 v_incr_usecount(vp, 1); 1952 1953 if (VSHOULDBUSY(vp)) 1954 vbusy(vp); 1955 if (flags & LK_TYPE_MASK) { 1956 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 1957 /* 1958 * must expand vrele here because we do not want 1959 * to call VOP_INACTIVE if the reference count 1960 * drops back to zero since it was never really 1961 * active. We must remove it from the free list 1962 * before sleeping so that multiple processes do 1963 * not try to recycle it. 1964 */ 1965 VI_LOCK(vp); 1966 v_incr_usecount(vp, -1); 1967 if (VSHOULDFREE(vp)) 1968 vfree(vp); 1969 else 1970 vlruvp(vp); 1971 VI_UNLOCK(vp); 1972 } 1973 return (error); 1974 } 1975 VI_UNLOCK(vp); 1976 return (0); 1977} 1978 1979/* 1980 * Increase the reference count of a vnode. 1981 */ 1982void 1983vref(struct vnode *vp) 1984{ 1985 1986 VI_LOCK(vp); 1987 v_incr_usecount(vp, 1); 1988 VI_UNLOCK(vp); 1989} 1990 1991/* 1992 * Return reference count of a vnode. 1993 * 1994 * The results of this call are only guaranteed when some mechanism other 1995 * than the VI lock is used to stop other processes from gaining references 1996 * to the vnode. This may be the case if the caller holds the only reference. 1997 * This is also useful when stale data is acceptable as race conditions may 1998 * be accounted for by some other means. 1999 */ 2000int 2001vrefcnt(struct vnode *vp) 2002{ 2003 int usecnt; 2004 2005 VI_LOCK(vp); 2006 usecnt = vp->v_usecount; 2007 VI_UNLOCK(vp); 2008 2009 return (usecnt); 2010} 2011 2012 2013/* 2014 * Vnode put/release. 2015 * If count drops to zero, call inactive routine and return to freelist. 2016 */ 2017void 2018vrele(vp) 2019 struct vnode *vp; 2020{ 2021 struct thread *td = curthread; /* XXX */ 2022 2023 GIANT_REQUIRED; 2024 2025 KASSERT(vp != NULL, ("vrele: null vp")); 2026 2027 VI_LOCK(vp); 2028 2029 /* Skip this v_writecount check if we're going to panic below. */ 2030 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2031 ("vrele: missed vn_close")); 2032 2033 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2034 vp->v_usecount == 1)) { 2035 v_incr_usecount(vp, -1); 2036 VI_UNLOCK(vp); 2037 2038 return; 2039 } 2040 2041 if (vp->v_usecount == 1) { 2042 v_incr_usecount(vp, -1); 2043 /* 2044 * We must call VOP_INACTIVE with the node locked. Mark 2045 * as VI_DOINGINACT to avoid recursion. 2046 */ 2047 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 2048 VI_LOCK(vp); 2049 vp->v_iflag |= VI_DOINGINACT; 2050 VI_UNLOCK(vp); 2051 VOP_INACTIVE(vp, td); 2052 VI_LOCK(vp); 2053 KASSERT(vp->v_iflag & VI_DOINGINACT, 2054 ("vrele: lost VI_DOINGINACT")); 2055 vp->v_iflag &= ~VI_DOINGINACT; 2056 } else 2057 VI_LOCK(vp); 2058 if (VSHOULDFREE(vp)) 2059 vfree(vp); 2060 else 2061 vlruvp(vp); 2062 VI_UNLOCK(vp); 2063 2064 } else { 2065#ifdef DIAGNOSTIC 2066 vprint("vrele: negative ref count", vp); 2067#endif 2068 VI_UNLOCK(vp); 2069 panic("vrele: negative ref cnt"); 2070 } 2071} 2072 2073/* 2074 * Release an already locked vnode. This give the same effects as 2075 * unlock+vrele(), but takes less time and avoids releasing and 2076 * re-aquiring the lock (as vrele() aquires the lock internally.) 2077 */ 2078void 2079vput(vp) 2080 struct vnode *vp; 2081{ 2082 struct thread *td = curthread; /* XXX */ 2083 2084 GIANT_REQUIRED; 2085 2086 KASSERT(vp != NULL, ("vput: null vp")); 2087 VI_LOCK(vp); 2088 /* Skip this v_writecount check if we're going to panic below. */ 2089 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2090 ("vput: missed vn_close")); 2091 2092 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2093 vp->v_usecount == 1)) { 2094 v_incr_usecount(vp, -1); 2095 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2096 return; 2097 } 2098 2099 if (vp->v_usecount == 1) { 2100 v_incr_usecount(vp, -1); 2101 /* 2102 * We must call VOP_INACTIVE with the node locked, so 2103 * we just need to release the vnode mutex. Mark as 2104 * as VI_DOINGINACT to avoid recursion. 2105 */ 2106 vp->v_iflag |= VI_DOINGINACT; 2107 VI_UNLOCK(vp); 2108 VOP_INACTIVE(vp, td); 2109 VI_LOCK(vp); 2110 KASSERT(vp->v_iflag & VI_DOINGINACT, 2111 ("vput: lost VI_DOINGINACT")); 2112 vp->v_iflag &= ~VI_DOINGINACT; 2113 if (VSHOULDFREE(vp)) 2114 vfree(vp); 2115 else 2116 vlruvp(vp); 2117 VI_UNLOCK(vp); 2118 2119 } else { 2120#ifdef DIAGNOSTIC 2121 vprint("vput: negative ref count", vp); 2122#endif 2123 panic("vput: negative ref cnt"); 2124 } 2125} 2126 2127/* 2128 * Somebody doesn't want the vnode recycled. 2129 */ 2130void 2131vhold(struct vnode *vp) 2132{ 2133 2134 VI_LOCK(vp); 2135 vholdl(vp); 2136 VI_UNLOCK(vp); 2137} 2138 2139void 2140vholdl(struct vnode *vp) 2141{ 2142 2143 vp->v_holdcnt++; 2144 if (VSHOULDBUSY(vp)) 2145 vbusy(vp); 2146} 2147 2148/* 2149 * Note that there is one less who cares about this vnode. vdrop() is the 2150 * opposite of vhold(). 2151 */ 2152void 2153vdrop(struct vnode *vp) 2154{ 2155 2156 VI_LOCK(vp); 2157 vdropl(vp); 2158 VI_UNLOCK(vp); 2159} 2160 2161void 2162vdropl(vp) 2163 register struct vnode *vp; 2164{ 2165 2166 if (vp->v_holdcnt <= 0) 2167 panic("vdrop: holdcnt"); 2168 vp->v_holdcnt--; 2169 if (VSHOULDFREE(vp)) 2170 vfree(vp); 2171 else 2172 vlruvp(vp); 2173} 2174 2175/* 2176 * Remove any vnodes in the vnode table belonging to mount point mp. 2177 * 2178 * If FORCECLOSE is not specified, there should not be any active ones, 2179 * return error if any are found (nb: this is a user error, not a 2180 * system error). If FORCECLOSE is specified, detach any active vnodes 2181 * that are found. 2182 * 2183 * If WRITECLOSE is set, only flush out regular file vnodes open for 2184 * writing. 2185 * 2186 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2187 * 2188 * `rootrefs' specifies the base reference count for the root vnode 2189 * of this filesystem. The root vnode is considered busy if its 2190 * v_usecount exceeds this value. On a successful return, vflush(, td) 2191 * will call vrele() on the root vnode exactly rootrefs times. 2192 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2193 * be zero. 2194 */ 2195#ifdef DIAGNOSTIC 2196static int busyprt = 0; /* print out busy vnodes */ 2197SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2198#endif 2199 2200int 2201vflush(mp, rootrefs, flags, td) 2202 struct mount *mp; 2203 int rootrefs; 2204 int flags; 2205 struct thread *td; 2206{ 2207 struct vnode *vp, *nvp, *rootvp = NULL; 2208 struct vattr vattr; 2209 int busy = 0, error; 2210 2211 if (rootrefs > 0) { 2212 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2213 ("vflush: bad args")); 2214 /* 2215 * Get the filesystem root vnode. We can vput() it 2216 * immediately, since with rootrefs > 0, it won't go away. 2217 */ 2218 if ((error = VFS_ROOT(mp, &rootvp, td)) != 0) 2219 return (error); 2220 vput(rootvp); 2221 2222 } 2223 MNT_ILOCK(mp); 2224loop: 2225 MNT_VNODE_FOREACH(vp, mp, nvp) { 2226 2227 VI_LOCK(vp); 2228 MNT_IUNLOCK(mp); 2229 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td); 2230 if (error) { 2231 MNT_ILOCK(mp); 2232 goto loop; 2233 } 2234 /* 2235 * Skip over a vnodes marked VV_SYSTEM. 2236 */ 2237 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2238 VOP_UNLOCK(vp, 0, td); 2239 MNT_ILOCK(mp); 2240 continue; 2241 } 2242 /* 2243 * If WRITECLOSE is set, flush out unlinked but still open 2244 * files (even if open only for reading) and regular file 2245 * vnodes open for writing. 2246 */ 2247 if (flags & WRITECLOSE) { 2248 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2249 VI_LOCK(vp); 2250 2251 if ((vp->v_type == VNON || 2252 (error == 0 && vattr.va_nlink > 0)) && 2253 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2254 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2255 MNT_ILOCK(mp); 2256 continue; 2257 } 2258 } else 2259 VI_LOCK(vp); 2260 2261 VOP_UNLOCK(vp, 0, td); 2262 2263 /* 2264 * With v_usecount == 0, all we need to do is clear out the 2265 * vnode data structures and we are done. 2266 */ 2267 if (vp->v_usecount == 0) { 2268 vgonel(vp, td); 2269 MNT_ILOCK(mp); 2270 continue; 2271 } 2272 2273 /* 2274 * If FORCECLOSE is set, forcibly close the vnode. For block 2275 * or character devices, revert to an anonymous device. For 2276 * all other files, just kill them. 2277 */ 2278 if (flags & FORCECLOSE) { 2279 if (vp->v_type != VCHR) 2280 vgonel(vp, td); 2281 else 2282 vgonechrl(vp, td); 2283 MNT_ILOCK(mp); 2284 continue; 2285 } 2286#ifdef DIAGNOSTIC 2287 if (busyprt) 2288 vprint("vflush: busy vnode", vp); 2289#endif 2290 VI_UNLOCK(vp); 2291 MNT_ILOCK(mp); 2292 busy++; 2293 } 2294 MNT_IUNLOCK(mp); 2295 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2296 /* 2297 * If just the root vnode is busy, and if its refcount 2298 * is equal to `rootrefs', then go ahead and kill it. 2299 */ 2300 VI_LOCK(rootvp); 2301 KASSERT(busy > 0, ("vflush: not busy")); 2302 KASSERT(rootvp->v_usecount >= rootrefs, 2303 ("vflush: usecount %d < rootrefs %d", 2304 rootvp->v_usecount, rootrefs)); 2305 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2306 vgonel(rootvp, td); 2307 busy = 0; 2308 } else 2309 VI_UNLOCK(rootvp); 2310 } 2311 if (busy) 2312 return (EBUSY); 2313 for (; rootrefs > 0; rootrefs--) 2314 vrele(rootvp); 2315 return (0); 2316} 2317 2318/* 2319 * This moves a now (likely recyclable) vnode to the end of the 2320 * mountlist. XXX However, it is temporarily disabled until we 2321 * can clean up ffs_sync() and friends, which have loop restart 2322 * conditions which this code causes to operate O(N^2). 2323 */ 2324static void 2325vlruvp(struct vnode *vp) 2326{ 2327#if 0 2328 struct mount *mp; 2329 2330 if ((mp = vp->v_mount) != NULL) { 2331 MNT_ILOCK(mp); 2332 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2333 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2334 MNT_IUNLOCK(mp); 2335 } 2336#endif 2337} 2338 2339static void 2340vx_lock(struct vnode *vp) 2341{ 2342 2343 ASSERT_VI_LOCKED(vp, "vx_lock"); 2344 2345 /* 2346 * Prevent the vnode from being recycled or brought into use while we 2347 * clean it out. 2348 */ 2349 if (vp->v_iflag & VI_XLOCK) 2350 panic("vclean: deadlock"); 2351 vp->v_iflag |= VI_XLOCK; 2352 vp->v_vxthread = curthread; 2353} 2354 2355static void 2356vx_unlock(struct vnode *vp) 2357{ 2358 ASSERT_VI_LOCKED(vp, "vx_unlock"); 2359 vp->v_iflag &= ~VI_XLOCK; 2360 vp->v_vxthread = NULL; 2361 if (vp->v_iflag & VI_XWANT) { 2362 vp->v_iflag &= ~VI_XWANT; 2363 wakeup(vp); 2364 } 2365} 2366 2367/* 2368 * Disassociate the underlying filesystem from a vnode. 2369 */ 2370static void 2371vclean(vp, flags, td) 2372 struct vnode *vp; 2373 int flags; 2374 struct thread *td; 2375{ 2376 int active; 2377 2378 ASSERT_VI_LOCKED(vp, "vclean"); 2379 /* 2380 * Check to see if the vnode is in use. If so we have to reference it 2381 * before we clean it out so that its count cannot fall to zero and 2382 * generate a race against ourselves to recycle it. 2383 */ 2384 if ((active = vp->v_usecount)) 2385 v_incr_usecount(vp, 1); 2386 2387 /* 2388 * Even if the count is zero, the VOP_INACTIVE routine may still 2389 * have the object locked while it cleans it out. The VOP_LOCK 2390 * ensures that the VOP_INACTIVE routine is done with its work. 2391 * For active vnodes, it ensures that no other activity can 2392 * occur while the underlying object is being cleaned out. 2393 */ 2394 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2395 2396 /* 2397 * Clean out any buffers associated with the vnode. 2398 * If the flush fails, just toss the buffers. 2399 */ 2400 if (flags & DOCLOSE) { 2401 struct buf *bp; 2402 bp = TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd); 2403 if (bp != NULL) 2404 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2405 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2406 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2407 } 2408 2409 VOP_DESTROYVOBJECT(vp); 2410 2411 /* 2412 * Any other processes trying to obtain this lock must first 2413 * wait for VXLOCK to clear, then call the new lock operation. 2414 */ 2415 VOP_UNLOCK(vp, 0, td); 2416 2417 /* 2418 * If purging an active vnode, it must be closed and 2419 * deactivated before being reclaimed. Note that the 2420 * VOP_INACTIVE will unlock the vnode. 2421 */ 2422 if (active) { 2423 if (flags & DOCLOSE) 2424 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2425 VI_LOCK(vp); 2426 if ((vp->v_iflag & VI_DOINGINACT) == 0) { 2427 vp->v_iflag |= VI_DOINGINACT; 2428 VI_UNLOCK(vp); 2429 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2430 panic("vclean: cannot relock."); 2431 VOP_INACTIVE(vp, td); 2432 VI_LOCK(vp); 2433 KASSERT(vp->v_iflag & VI_DOINGINACT, 2434 ("vclean: lost VI_DOINGINACT")); 2435 vp->v_iflag &= ~VI_DOINGINACT; 2436 } 2437 VI_UNLOCK(vp); 2438 } 2439 /* 2440 * Reclaim the vnode. 2441 */ 2442 if (VOP_RECLAIM(vp, td)) 2443 panic("vclean: cannot reclaim"); 2444 2445 if (active) { 2446 /* 2447 * Inline copy of vrele() since VOP_INACTIVE 2448 * has already been called. 2449 */ 2450 VI_LOCK(vp); 2451 v_incr_usecount(vp, -1); 2452 if (vp->v_usecount <= 0) { 2453#ifdef INVARIANTS 2454 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2455 vprint("vclean: bad ref count", vp); 2456 panic("vclean: ref cnt"); 2457 } 2458#endif 2459 if (VSHOULDFREE(vp)) 2460 vfree(vp); 2461 } 2462 VI_UNLOCK(vp); 2463 } 2464 /* 2465 * Delete from old mount point vnode list. 2466 */ 2467 delmntque(vp); 2468 cache_purge(vp); 2469 VI_LOCK(vp); 2470 if (VSHOULDFREE(vp)) 2471 vfree(vp); 2472 2473 /* 2474 * Done with purge, reset to the standard lock and 2475 * notify sleepers of the grim news. 2476 */ 2477 vp->v_vnlock = &vp->v_lock; 2478 vp->v_op = dead_vnodeop_p; 2479 if (vp->v_pollinfo != NULL) 2480 vn_pollgone(vp); 2481 vp->v_tag = "none"; 2482} 2483 2484/* 2485 * Eliminate all activity associated with the requested vnode 2486 * and with all vnodes aliased to the requested vnode. 2487 */ 2488int 2489vop_revoke(ap) 2490 struct vop_revoke_args /* { 2491 struct vnode *a_vp; 2492 int a_flags; 2493 } */ *ap; 2494{ 2495 struct vnode *vp, *vq; 2496 struct cdev *dev; 2497 2498 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2499 vp = ap->a_vp; 2500 KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); 2501 2502 VI_LOCK(vp); 2503 /* 2504 * If a vgone (or vclean) is already in progress, 2505 * wait until it is done and return. 2506 */ 2507 if (vp->v_iflag & VI_XLOCK) { 2508 vp->v_iflag |= VI_XWANT; 2509 msleep(vp, VI_MTX(vp), PINOD | PDROP, 2510 "vop_revokeall", 0); 2511 return (0); 2512 } 2513 VI_UNLOCK(vp); 2514 dev = vp->v_rdev; 2515 for (;;) { 2516 dev_lock(); 2517 vq = SLIST_FIRST(&dev->si_hlist); 2518 dev_unlock(); 2519 if (vq == NULL) 2520 break; 2521 vgone(vq); 2522 } 2523 return (0); 2524} 2525 2526/* 2527 * Recycle an unused vnode to the front of the free list. 2528 * Release the passed interlock if the vnode will be recycled. 2529 */ 2530int 2531vrecycle(vp, inter_lkp, td) 2532 struct vnode *vp; 2533 struct mtx *inter_lkp; 2534 struct thread *td; 2535{ 2536 2537 VI_LOCK(vp); 2538 if (vp->v_usecount == 0) { 2539 if (inter_lkp) { 2540 mtx_unlock(inter_lkp); 2541 } 2542 vgonel(vp, td); 2543 return (1); 2544 } 2545 VI_UNLOCK(vp); 2546 return (0); 2547} 2548 2549/* 2550 * Eliminate all activity associated with a vnode 2551 * in preparation for reuse. 2552 */ 2553void 2554vgone(vp) 2555 register struct vnode *vp; 2556{ 2557 struct thread *td = curthread; /* XXX */ 2558 2559 VI_LOCK(vp); 2560 vgonel(vp, td); 2561} 2562 2563/* 2564 * Disassociate a character device from the its underlying filesystem and 2565 * attach it to spec. This is for use when the chr device is still active 2566 * and the filesystem is going away. 2567 */ 2568static void 2569vgonechrl(struct vnode *vp, struct thread *td) 2570{ 2571 ASSERT_VI_LOCKED(vp, "vgonechrl"); 2572 vx_lock(vp); 2573 /* 2574 * This is a custom version of vclean() which does not tearm down 2575 * the bufs or vm objects held by this vnode. This allows filesystems 2576 * to continue using devices which were discovered via another 2577 * filesystem that has been unmounted. 2578 */ 2579 if (vp->v_usecount != 0) { 2580 v_incr_usecount(vp, 1); 2581 /* 2582 * Ensure that no other activity can occur while the 2583 * underlying object is being cleaned out. 2584 */ 2585 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2586 /* 2587 * Any other processes trying to obtain this lock must first 2588 * wait for VXLOCK to clear, then call the new lock operation. 2589 */ 2590 VOP_UNLOCK(vp, 0, td); 2591 vp->v_vnlock = &vp->v_lock; 2592 vp->v_tag = "orphanchr"; 2593 vp->v_op = devfs_specop_p; 2594 delmntque(vp); 2595 cache_purge(vp); 2596 vrele(vp); 2597 VI_LOCK(vp); 2598 } else 2599 vclean(vp, 0, td); 2600 vp->v_op = devfs_specop_p; 2601 vx_unlock(vp); 2602 VI_UNLOCK(vp); 2603} 2604 2605/* 2606 * vgone, with the vp interlock held. 2607 */ 2608void 2609vgonel(vp, td) 2610 struct vnode *vp; 2611 struct thread *td; 2612{ 2613 /* 2614 * If a vgone (or vclean) is already in progress, 2615 * wait until it is done and return. 2616 */ 2617 ASSERT_VI_LOCKED(vp, "vgonel"); 2618 if (vp->v_iflag & VI_XLOCK) { 2619 vp->v_iflag |= VI_XWANT; 2620 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); 2621 return; 2622 } 2623 vx_lock(vp); 2624 2625 /* 2626 * Clean out the filesystem specific data. 2627 */ 2628 vclean(vp, DOCLOSE, td); 2629 VI_UNLOCK(vp); 2630 2631 /* 2632 * If special device, remove it from special device alias list 2633 * if it is on one. 2634 */ 2635 VI_LOCK(vp); 2636 if (vp->v_type == VCHR && vp->v_rdev != NULL) 2637 dev_rel(vp); 2638 2639 /* 2640 * If it is on the freelist and not already at the head, 2641 * move it to the head of the list. The test of the 2642 * VDOOMED flag and the reference count of zero is because 2643 * it will be removed from the free list by getnewvnode, 2644 * but will not have its reference count incremented until 2645 * after calling vgone. If the reference count were 2646 * incremented first, vgone would (incorrectly) try to 2647 * close the previous instance of the underlying object. 2648 */ 2649 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2650 mtx_lock(&vnode_free_list_mtx); 2651 if (vp->v_iflag & VI_FREE) { 2652 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2653 } else { 2654 vp->v_iflag |= VI_FREE; 2655 freevnodes++; 2656 } 2657 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2658 mtx_unlock(&vnode_free_list_mtx); 2659 } 2660 2661 vp->v_type = VBAD; 2662 vx_unlock(vp); 2663 VI_UNLOCK(vp); 2664} 2665 2666/* 2667 * Lookup a vnode by device number. 2668 */ 2669int 2670vfinddev(dev, vpp) 2671 struct cdev *dev; 2672 struct vnode **vpp; 2673{ 2674 struct vnode *vp; 2675 2676 dev_lock(); 2677 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2678 *vpp = vp; 2679 dev_unlock(); 2680 return (1); 2681 } 2682 dev_unlock(); 2683 return (0); 2684} 2685 2686/* 2687 * Calculate the total number of references to a special device. 2688 */ 2689int 2690vcount(vp) 2691 struct vnode *vp; 2692{ 2693 int count; 2694 2695 dev_lock(); 2696 count = vp->v_rdev->si_usecount; 2697 dev_unlock(); 2698 return (count); 2699} 2700 2701/* 2702 * Same as above, but using the struct cdev *as argument 2703 */ 2704int 2705count_dev(dev) 2706 struct cdev *dev; 2707{ 2708 int count; 2709 2710 dev_lock(); 2711 count = dev->si_usecount; 2712 dev_unlock(); 2713 return(count); 2714} 2715 2716/* 2717 * Print out a description of a vnode. 2718 */ 2719static char *typename[] = 2720{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2721 2722void 2723vprint(label, vp) 2724 char *label; 2725 struct vnode *vp; 2726{ 2727 char buf[96]; 2728 2729 if (label != NULL) 2730 printf("%s: %p: ", label, (void *)vp); 2731 else 2732 printf("%p: ", (void *)vp); 2733 printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", 2734 vp->v_tag, typename[vp->v_type], vp->v_usecount, 2735 vp->v_writecount, vp->v_holdcnt); 2736 buf[0] = '\0'; 2737 if (vp->v_vflag & VV_ROOT) 2738 strcat(buf, "|VV_ROOT"); 2739 if (vp->v_vflag & VV_TEXT) 2740 strcat(buf, "|VV_TEXT"); 2741 if (vp->v_vflag & VV_SYSTEM) 2742 strcat(buf, "|VV_SYSTEM"); 2743 if (vp->v_iflag & VI_XLOCK) 2744 strcat(buf, "|VI_XLOCK"); 2745 if (vp->v_iflag & VI_XWANT) 2746 strcat(buf, "|VI_XWANT"); 2747 if (vp->v_iflag & VI_DOOMED) 2748 strcat(buf, "|VI_DOOMED"); 2749 if (vp->v_iflag & VI_FREE) 2750 strcat(buf, "|VI_FREE"); 2751 if (vp->v_vflag & VV_OBJBUF) 2752 strcat(buf, "|VV_OBJBUF"); 2753 if (buf[0] != '\0') 2754 printf(" flags (%s),", &buf[1]); 2755 lockmgr_printinfo(vp->v_vnlock); 2756 printf("\n"); 2757 if (vp->v_data != NULL) 2758 VOP_PRINT(vp); 2759} 2760 2761#ifdef DDB 2762#include <ddb/ddb.h> 2763/* 2764 * List all of the locked vnodes in the system. 2765 * Called when debugging the kernel. 2766 */ 2767DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2768{ 2769 struct mount *mp, *nmp; 2770 struct vnode *vp; 2771 2772 /* 2773 * Note: because this is DDB, we can't obey the locking semantics 2774 * for these structures, which means we could catch an inconsistent 2775 * state and dereference a nasty pointer. Not much to be done 2776 * about that. 2777 */ 2778 printf("Locked vnodes\n"); 2779 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2780 nmp = TAILQ_NEXT(mp, mnt_list); 2781 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2782 if (VOP_ISLOCKED(vp, NULL)) 2783 vprint(NULL, vp); 2784 } 2785 nmp = TAILQ_NEXT(mp, mnt_list); 2786 } 2787} 2788#endif 2789 2790/* 2791 * Fill in a struct xvfsconf based on a struct vfsconf. 2792 */ 2793static void 2794vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2795{ 2796 2797 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2798 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2799 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2800 xvfsp->vfc_flags = vfsp->vfc_flags; 2801 /* 2802 * These are unused in userland, we keep them 2803 * to not break binary compatibility. 2804 */ 2805 xvfsp->vfc_vfsops = NULL; 2806 xvfsp->vfc_next = NULL; 2807} 2808 2809/* 2810 * Top level filesystem related information gathering. 2811 */ 2812static int 2813sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2814{ 2815 struct vfsconf *vfsp; 2816 struct xvfsconf xvfsp; 2817 int error; 2818 2819 error = 0; 2820 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2821 vfsconf2x(vfsp, &xvfsp); 2822 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); 2823 if (error) 2824 break; 2825 } 2826 return (error); 2827} 2828 2829SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2830 "S,xvfsconf", "List of all configured filesystems"); 2831 2832#ifndef BURN_BRIDGES 2833static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2834 2835static int 2836vfs_sysctl(SYSCTL_HANDLER_ARGS) 2837{ 2838 int *name = (int *)arg1 - 1; /* XXX */ 2839 u_int namelen = arg2 + 1; /* XXX */ 2840 struct vfsconf *vfsp; 2841 struct xvfsconf xvfsp; 2842 2843 printf("WARNING: userland calling deprecated sysctl, " 2844 "please rebuild world\n"); 2845 2846#if 1 || defined(COMPAT_PRELITE2) 2847 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2848 if (namelen == 1) 2849 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2850#endif 2851 2852 switch (name[1]) { 2853 case VFS_MAXTYPENUM: 2854 if (namelen != 2) 2855 return (ENOTDIR); 2856 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2857 case VFS_CONF: 2858 if (namelen != 3) 2859 return (ENOTDIR); /* overloaded */ 2860 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 2861 if (vfsp->vfc_typenum == name[2]) 2862 break; 2863 if (vfsp == NULL) 2864 return (EOPNOTSUPP); 2865 vfsconf2x(vfsp, &xvfsp); 2866 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2867 } 2868 return (EOPNOTSUPP); 2869} 2870 2871SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 2872 "Generic filesystem"); 2873 2874#if 1 || defined(COMPAT_PRELITE2) 2875 2876static int 2877sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2878{ 2879 int error; 2880 struct vfsconf *vfsp; 2881 struct ovfsconf ovfs; 2882 2883 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2884 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2885 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2886 ovfs.vfc_index = vfsp->vfc_typenum; 2887 ovfs.vfc_refcount = vfsp->vfc_refcount; 2888 ovfs.vfc_flags = vfsp->vfc_flags; 2889 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2890 if (error) 2891 return error; 2892 } 2893 return 0; 2894} 2895 2896#endif /* 1 || COMPAT_PRELITE2 */ 2897#endif /* !BURN_BRIDGES */ 2898 2899#define KINFO_VNODESLOP 10 2900#ifdef notyet 2901/* 2902 * Dump vnode list (via sysctl). 2903 */ 2904/* ARGSUSED */ 2905static int 2906sysctl_vnode(SYSCTL_HANDLER_ARGS) 2907{ 2908 struct xvnode *xvn; 2909 struct thread *td = req->td; 2910 struct mount *mp; 2911 struct vnode *vp; 2912 int error, len, n; 2913 2914 /* 2915 * Stale numvnodes access is not fatal here. 2916 */ 2917 req->lock = 0; 2918 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 2919 if (!req->oldptr) 2920 /* Make an estimate */ 2921 return (SYSCTL_OUT(req, 0, len)); 2922 2923 error = sysctl_wire_old_buffer(req, 0); 2924 if (error != 0) 2925 return (error); 2926 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 2927 n = 0; 2928 mtx_lock(&mountlist_mtx); 2929 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2930 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 2931 continue; 2932 MNT_ILOCK(mp); 2933 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2934 if (n == len) 2935 break; 2936 vref(vp); 2937 xvn[n].xv_size = sizeof *xvn; 2938 xvn[n].xv_vnode = vp; 2939#define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 2940 XV_COPY(usecount); 2941 XV_COPY(writecount); 2942 XV_COPY(holdcnt); 2943 XV_COPY(id); 2944 XV_COPY(mount); 2945 XV_COPY(numoutput); 2946 XV_COPY(type); 2947#undef XV_COPY 2948 xvn[n].xv_flag = vp->v_vflag; 2949 2950 switch (vp->v_type) { 2951 case VREG: 2952 case VDIR: 2953 case VLNK: 2954 xvn[n].xv_ino = vp->v_cachedid; 2955 break; 2956 case VBLK: 2957 case VCHR: 2958 if (vp->v_rdev == NULL) { 2959 vrele(vp); 2960 continue; 2961 } 2962 xvn[n].xv_dev = dev2udev(vp->v_rdev); 2963 break; 2964 case VSOCK: 2965 xvn[n].xv_socket = vp->v_socket; 2966 break; 2967 case VFIFO: 2968 xvn[n].xv_fifo = vp->v_fifoinfo; 2969 break; 2970 case VNON: 2971 case VBAD: 2972 default: 2973 /* shouldn't happen? */ 2974 vrele(vp); 2975 continue; 2976 } 2977 vrele(vp); 2978 ++n; 2979 } 2980 MNT_IUNLOCK(mp); 2981 mtx_lock(&mountlist_mtx); 2982 vfs_unbusy(mp, td); 2983 if (n == len) 2984 break; 2985 } 2986 mtx_unlock(&mountlist_mtx); 2987 2988 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 2989 free(xvn, M_TEMP); 2990 return (error); 2991} 2992 2993SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2994 0, 0, sysctl_vnode, "S,xvnode", ""); 2995#endif 2996 2997/* 2998 * Unmount all filesystems. The list is traversed in reverse order 2999 * of mounting to avoid dependencies. 3000 */ 3001void 3002vfs_unmountall() 3003{ 3004 struct mount *mp; 3005 struct thread *td; 3006 int error; 3007 3008 if (curthread != NULL) 3009 td = curthread; 3010 else 3011 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 3012 /* 3013 * Since this only runs when rebooting, it is not interlocked. 3014 */ 3015 while(!TAILQ_EMPTY(&mountlist)) { 3016 mp = TAILQ_LAST(&mountlist, mntlist); 3017 error = dounmount(mp, MNT_FORCE, td); 3018 if (error) { 3019 TAILQ_REMOVE(&mountlist, mp, mnt_list); 3020 printf("unmount of %s failed (", 3021 mp->mnt_stat.f_mntonname); 3022 if (error == EBUSY) 3023 printf("BUSY)\n"); 3024 else 3025 printf("%d)\n", error); 3026 } else { 3027 /* The unmount has removed mp from the mountlist */ 3028 } 3029 } 3030} 3031 3032/* 3033 * perform msync on all vnodes under a mount point 3034 * the mount point must be locked. 3035 */ 3036void 3037vfs_msync(struct mount *mp, int flags) 3038{ 3039 struct vnode *vp, *nvp; 3040 struct vm_object *obj; 3041 int tries; 3042 3043 GIANT_REQUIRED; 3044 3045 tries = 5; 3046 MNT_ILOCK(mp); 3047loop: 3048 TAILQ_FOREACH_SAFE(vp, &mp->mnt_nvnodelist, v_nmntvnodes, nvp) { 3049 if (vp->v_mount != mp) { 3050 if (--tries > 0) 3051 goto loop; 3052 break; 3053 } 3054 3055 VI_LOCK(vp); 3056 if (vp->v_iflag & VI_XLOCK) { 3057 VI_UNLOCK(vp); 3058 continue; 3059 } 3060 3061 if ((vp->v_iflag & VI_OBJDIRTY) && 3062 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 3063 MNT_IUNLOCK(mp); 3064 if (!vget(vp, 3065 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3066 curthread)) { 3067 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3068 vput(vp); 3069 MNT_ILOCK(mp); 3070 continue; 3071 } 3072 3073 if (VOP_GETVOBJECT(vp, &obj) == 0) { 3074 VM_OBJECT_LOCK(obj); 3075 vm_object_page_clean(obj, 0, 0, 3076 flags == MNT_WAIT ? 3077 OBJPC_SYNC : OBJPC_NOSYNC); 3078 VM_OBJECT_UNLOCK(obj); 3079 } 3080 vput(vp); 3081 } 3082 MNT_ILOCK(mp); 3083 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3084 if (--tries > 0) 3085 goto loop; 3086 break; 3087 } 3088 } else 3089 VI_UNLOCK(vp); 3090 } 3091 MNT_IUNLOCK(mp); 3092} 3093 3094/* 3095 * Create the VM object needed for VMIO and mmap support. This 3096 * is done for all VREG files in the system. Some filesystems might 3097 * afford the additional metadata buffering capability of the 3098 * VMIO code by making the device node be VMIO mode also. 3099 * 3100 * vp must be locked when vfs_object_create is called. 3101 */ 3102int 3103vfs_object_create(struct vnode *vp, struct thread *td, struct ucred *cred) 3104{ 3105 3106 GIANT_REQUIRED; 3107 return (VOP_CREATEVOBJECT(vp, cred, td)); 3108} 3109 3110/* 3111 * Mark a vnode as free, putting it up for recycling. 3112 */ 3113void 3114vfree(struct vnode *vp) 3115{ 3116 3117 ASSERT_VI_LOCKED(vp, "vfree"); 3118 mtx_lock(&vnode_free_list_mtx); 3119 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3120 if (vp->v_iflag & VI_AGE) { 3121 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3122 } else { 3123 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3124 } 3125 freevnodes++; 3126 mtx_unlock(&vnode_free_list_mtx); 3127 vp->v_iflag &= ~VI_AGE; 3128 vp->v_iflag |= VI_FREE; 3129} 3130 3131/* 3132 * Opposite of vfree() - mark a vnode as in use. 3133 */ 3134void 3135vbusy(struct vnode *vp) 3136{ 3137 3138 ASSERT_VI_LOCKED(vp, "vbusy"); 3139 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3140 3141 mtx_lock(&vnode_free_list_mtx); 3142 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3143 freevnodes--; 3144 mtx_unlock(&vnode_free_list_mtx); 3145 3146 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3147} 3148 3149/* 3150 * Initalize per-vnode helper structure to hold poll-related state. 3151 */ 3152void 3153v_addpollinfo(struct vnode *vp) 3154{ 3155 struct vpollinfo *vi; 3156 3157 vi = uma_zalloc(vnodepoll_zone, M_WAITOK); 3158 if (vp->v_pollinfo != NULL) { 3159 uma_zfree(vnodepoll_zone, vi); 3160 return; 3161 } 3162 vp->v_pollinfo = vi; 3163 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3164 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, 3165 &vp->v_pollinfo->vpi_lock); 3166} 3167 3168/* 3169 * Record a process's interest in events which might happen to 3170 * a vnode. Because poll uses the historic select-style interface 3171 * internally, this routine serves as both the ``check for any 3172 * pending events'' and the ``record my interest in future events'' 3173 * functions. (These are done together, while the lock is held, 3174 * to avoid race conditions.) 3175 */ 3176int 3177vn_pollrecord(vp, td, events) 3178 struct vnode *vp; 3179 struct thread *td; 3180 short events; 3181{ 3182 3183 if (vp->v_pollinfo == NULL) 3184 v_addpollinfo(vp); 3185 mtx_lock(&vp->v_pollinfo->vpi_lock); 3186 if (vp->v_pollinfo->vpi_revents & events) { 3187 /* 3188 * This leaves events we are not interested 3189 * in available for the other process which 3190 * which presumably had requested them 3191 * (otherwise they would never have been 3192 * recorded). 3193 */ 3194 events &= vp->v_pollinfo->vpi_revents; 3195 vp->v_pollinfo->vpi_revents &= ~events; 3196 3197 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3198 return events; 3199 } 3200 vp->v_pollinfo->vpi_events |= events; 3201 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3202 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3203 return 0; 3204} 3205 3206/* 3207 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3208 * it is possible for us to miss an event due to race conditions, but 3209 * that condition is expected to be rare, so for the moment it is the 3210 * preferred interface. 3211 */ 3212void 3213vn_pollevent(vp, events) 3214 struct vnode *vp; 3215 short events; 3216{ 3217 3218 if (vp->v_pollinfo == NULL) 3219 v_addpollinfo(vp); 3220 mtx_lock(&vp->v_pollinfo->vpi_lock); 3221 if (vp->v_pollinfo->vpi_events & events) { 3222 /* 3223 * We clear vpi_events so that we don't 3224 * call selwakeup() twice if two events are 3225 * posted before the polling process(es) is 3226 * awakened. This also ensures that we take at 3227 * most one selwakeup() if the polling process 3228 * is no longer interested. However, it does 3229 * mean that only one event can be noticed at 3230 * a time. (Perhaps we should only clear those 3231 * event bits which we note?) XXX 3232 */ 3233 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3234 vp->v_pollinfo->vpi_revents |= events; 3235 selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); 3236 } 3237 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3238} 3239 3240/* 3241 * Wake up anyone polling on vp because it is being revoked. 3242 * This depends on dead_poll() returning POLLHUP for correct 3243 * behavior. 3244 */ 3245void 3246vn_pollgone(vp) 3247 struct vnode *vp; 3248{ 3249 3250 mtx_lock(&vp->v_pollinfo->vpi_lock); 3251 VN_KNOTE_LOCKED(vp, NOTE_REVOKE); 3252 if (vp->v_pollinfo->vpi_events) { 3253 vp->v_pollinfo->vpi_events = 0; 3254 selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); 3255 } 3256 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3257} 3258 3259 3260 3261/* 3262 * Routine to create and manage a filesystem syncer vnode. 3263 */ 3264#define sync_close ((int (*)(struct vop_close_args *))nullop) 3265static int sync_fsync(struct vop_fsync_args *); 3266static int sync_inactive(struct vop_inactive_args *); 3267static int sync_reclaim(struct vop_reclaim_args *); 3268 3269static vop_t **sync_vnodeop_p; 3270static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3271 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3272 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3273 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3274 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3275 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3276 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3277 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3278 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3279 { NULL, NULL } 3280}; 3281static struct vnodeopv_desc sync_vnodeop_opv_desc = 3282 { &sync_vnodeop_p, sync_vnodeop_entries }; 3283 3284VNODEOP_SET(sync_vnodeop_opv_desc); 3285 3286/* 3287 * Create a new filesystem syncer vnode for the specified mount point. 3288 */ 3289int 3290vfs_allocate_syncvnode(mp) 3291 struct mount *mp; 3292{ 3293 struct vnode *vp; 3294 static long start, incr, next; 3295 int error; 3296 3297 /* Allocate a new vnode */ 3298 if ((error = getnewvnode("syncer", mp, sync_vnodeop_p, &vp)) != 0) { 3299 mp->mnt_syncer = NULL; 3300 return (error); 3301 } 3302 vp->v_type = VNON; 3303 /* 3304 * Place the vnode onto the syncer worklist. We attempt to 3305 * scatter them about on the list so that they will go off 3306 * at evenly distributed times even if all the filesystems 3307 * are mounted at once. 3308 */ 3309 next += incr; 3310 if (next == 0 || next > syncer_maxdelay) { 3311 start /= 2; 3312 incr /= 2; 3313 if (start == 0) { 3314 start = syncer_maxdelay / 2; 3315 incr = syncer_maxdelay; 3316 } 3317 next = start; 3318 } 3319 VI_LOCK(vp); 3320 vn_syncer_add_to_worklist(&vp->v_bufobj, 3321 syncdelay > 0 ? next % syncdelay : 0); 3322 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 3323 mtx_lock(&sync_mtx); 3324 sync_vnode_count++; 3325 mtx_unlock(&sync_mtx); 3326 VI_UNLOCK(vp); 3327 mp->mnt_syncer = vp; 3328 return (0); 3329} 3330 3331/* 3332 * Do a lazy sync of the filesystem. 3333 */ 3334static int 3335sync_fsync(ap) 3336 struct vop_fsync_args /* { 3337 struct vnode *a_vp; 3338 struct ucred *a_cred; 3339 int a_waitfor; 3340 struct thread *a_td; 3341 } */ *ap; 3342{ 3343 struct vnode *syncvp = ap->a_vp; 3344 struct mount *mp = syncvp->v_mount; 3345 struct thread *td = ap->a_td; 3346 int error, asyncflag; 3347 struct bufobj *bo; 3348 3349 /* 3350 * We only need to do something if this is a lazy evaluation. 3351 */ 3352 if (ap->a_waitfor != MNT_LAZY) 3353 return (0); 3354 3355 /* 3356 * Move ourselves to the back of the sync list. 3357 */ 3358 bo = &syncvp->v_bufobj; 3359 BO_LOCK(bo); 3360 vn_syncer_add_to_worklist(bo, syncdelay); 3361 BO_UNLOCK(bo); 3362 3363 /* 3364 * Walk the list of vnodes pushing all that are dirty and 3365 * not already on the sync list. 3366 */ 3367 mtx_lock(&mountlist_mtx); 3368 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3369 mtx_unlock(&mountlist_mtx); 3370 return (0); 3371 } 3372 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3373 vfs_unbusy(mp, td); 3374 return (0); 3375 } 3376 asyncflag = mp->mnt_flag & MNT_ASYNC; 3377 mp->mnt_flag &= ~MNT_ASYNC; 3378 vfs_msync(mp, MNT_NOWAIT); 3379 error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3380 if (asyncflag) 3381 mp->mnt_flag |= MNT_ASYNC; 3382 vn_finished_write(mp); 3383 vfs_unbusy(mp, td); 3384 return (error); 3385} 3386 3387/* 3388 * The syncer vnode is no referenced. 3389 */ 3390static int 3391sync_inactive(ap) 3392 struct vop_inactive_args /* { 3393 struct vnode *a_vp; 3394 struct thread *a_td; 3395 } */ *ap; 3396{ 3397 3398 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3399 vgone(ap->a_vp); 3400 return (0); 3401} 3402 3403/* 3404 * The syncer vnode is no longer needed and is being decommissioned. 3405 * 3406 * Modifications to the worklist must be protected by sync_mtx. 3407 */ 3408static int 3409sync_reclaim(ap) 3410 struct vop_reclaim_args /* { 3411 struct vnode *a_vp; 3412 } */ *ap; 3413{ 3414 struct vnode *vp = ap->a_vp; 3415 struct bufobj *bo; 3416 3417 VI_LOCK(vp); 3418 bo = &vp->v_bufobj; 3419 vp->v_mount->mnt_syncer = NULL; 3420 if (bo->bo_flag & BO_ONWORKLST) { 3421 mtx_lock(&sync_mtx); 3422 LIST_REMOVE(bo, bo_synclist); 3423 syncer_worklist_len--; 3424 sync_vnode_count--; 3425 mtx_unlock(&sync_mtx); 3426 bo->bo_flag &= ~BO_ONWORKLST; 3427 } 3428 VI_UNLOCK(vp); 3429 3430 return (0); 3431} 3432 3433/* 3434 * Check if vnode represents a disk device 3435 */ 3436int 3437vn_isdisk(vp, errp) 3438 struct vnode *vp; 3439 int *errp; 3440{ 3441 int error; 3442 3443 error = 0; 3444 dev_lock(); 3445 if (vp->v_type != VCHR) 3446 error = ENOTBLK; 3447 else if (vp->v_rdev == NULL) 3448 error = ENXIO; 3449 else if (vp->v_rdev->si_devsw == NULL) 3450 error = ENXIO; 3451 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 3452 error = ENOTBLK; 3453 dev_unlock(); 3454 if (errp != NULL) 3455 *errp = error; 3456 return (error == 0); 3457} 3458 3459/* 3460 * Free data allocated by namei(); see namei(9) for details. 3461 */ 3462void 3463NDFREE(ndp, flags) 3464 struct nameidata *ndp; 3465 const u_int flags; 3466{ 3467 3468 if (!(flags & NDF_NO_FREE_PNBUF) && 3469 (ndp->ni_cnd.cn_flags & HASBUF)) { 3470 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3471 ndp->ni_cnd.cn_flags &= ~HASBUF; 3472 } 3473 if (!(flags & NDF_NO_DVP_UNLOCK) && 3474 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3475 ndp->ni_dvp != ndp->ni_vp) 3476 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3477 if (!(flags & NDF_NO_DVP_RELE) && 3478 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3479 vrele(ndp->ni_dvp); 3480 ndp->ni_dvp = NULL; 3481 } 3482 if (!(flags & NDF_NO_VP_UNLOCK) && 3483 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3484 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3485 if (!(flags & NDF_NO_VP_RELE) && 3486 ndp->ni_vp) { 3487 vrele(ndp->ni_vp); 3488 ndp->ni_vp = NULL; 3489 } 3490 if (!(flags & NDF_NO_STARTDIR_RELE) && 3491 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3492 vrele(ndp->ni_startdir); 3493 ndp->ni_startdir = NULL; 3494 } 3495} 3496 3497/* 3498 * Common filesystem object access control check routine. Accepts a 3499 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3500 * and optional call-by-reference privused argument allowing vaccess() 3501 * to indicate to the caller whether privilege was used to satisfy the 3502 * request (obsoleted). Returns 0 on success, or an errno on failure. 3503 */ 3504int 3505vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3506 enum vtype type; 3507 mode_t file_mode; 3508 uid_t file_uid; 3509 gid_t file_gid; 3510 mode_t acc_mode; 3511 struct ucred *cred; 3512 int *privused; 3513{ 3514 mode_t dac_granted; 3515#ifdef CAPABILITIES 3516 mode_t cap_granted; 3517#endif 3518 3519 /* 3520 * Look for a normal, non-privileged way to access the file/directory 3521 * as requested. If it exists, go with that. 3522 */ 3523 3524 if (privused != NULL) 3525 *privused = 0; 3526 3527 dac_granted = 0; 3528 3529 /* Check the owner. */ 3530 if (cred->cr_uid == file_uid) { 3531 dac_granted |= VADMIN; 3532 if (file_mode & S_IXUSR) 3533 dac_granted |= VEXEC; 3534 if (file_mode & S_IRUSR) 3535 dac_granted |= VREAD; 3536 if (file_mode & S_IWUSR) 3537 dac_granted |= (VWRITE | VAPPEND); 3538 3539 if ((acc_mode & dac_granted) == acc_mode) 3540 return (0); 3541 3542 goto privcheck; 3543 } 3544 3545 /* Otherwise, check the groups (first match) */ 3546 if (groupmember(file_gid, cred)) { 3547 if (file_mode & S_IXGRP) 3548 dac_granted |= VEXEC; 3549 if (file_mode & S_IRGRP) 3550 dac_granted |= VREAD; 3551 if (file_mode & S_IWGRP) 3552 dac_granted |= (VWRITE | VAPPEND); 3553 3554 if ((acc_mode & dac_granted) == acc_mode) 3555 return (0); 3556 3557 goto privcheck; 3558 } 3559 3560 /* Otherwise, check everyone else. */ 3561 if (file_mode & S_IXOTH) 3562 dac_granted |= VEXEC; 3563 if (file_mode & S_IROTH) 3564 dac_granted |= VREAD; 3565 if (file_mode & S_IWOTH) 3566 dac_granted |= (VWRITE | VAPPEND); 3567 if ((acc_mode & dac_granted) == acc_mode) 3568 return (0); 3569 3570privcheck: 3571 if (!suser_cred(cred, SUSER_ALLOWJAIL)) { 3572 /* XXX audit: privilege used */ 3573 if (privused != NULL) 3574 *privused = 1; 3575 return (0); 3576 } 3577 3578#ifdef CAPABILITIES 3579 /* 3580 * Build a capability mask to determine if the set of capabilities 3581 * satisfies the requirements when combined with the granted mask 3582 * from above. 3583 * For each capability, if the capability is required, bitwise 3584 * or the request type onto the cap_granted mask. 3585 */ 3586 cap_granted = 0; 3587 3588 if (type == VDIR) { 3589 /* 3590 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3591 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3592 */ 3593 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3594 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) 3595 cap_granted |= VEXEC; 3596 } else { 3597 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3598 !cap_check(cred, NULL, CAP_DAC_EXECUTE, SUSER_ALLOWJAIL)) 3599 cap_granted |= VEXEC; 3600 } 3601 3602 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3603 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) 3604 cap_granted |= VREAD; 3605 3606 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3607 !cap_check(cred, NULL, CAP_DAC_WRITE, SUSER_ALLOWJAIL)) 3608 cap_granted |= (VWRITE | VAPPEND); 3609 3610 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3611 !cap_check(cred, NULL, CAP_FOWNER, SUSER_ALLOWJAIL)) 3612 cap_granted |= VADMIN; 3613 3614 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3615 /* XXX audit: privilege used */ 3616 if (privused != NULL) 3617 *privused = 1; 3618 return (0); 3619 } 3620#endif 3621 3622 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3623} 3624 3625/* 3626 * Credential check based on process requesting service, and per-attribute 3627 * permissions. 3628 */ 3629int 3630extattr_check_cred(struct vnode *vp, int attrnamespace, 3631 struct ucred *cred, struct thread *td, int access) 3632{ 3633 3634 /* 3635 * Kernel-invoked always succeeds. 3636 */ 3637 if (cred == NOCRED) 3638 return (0); 3639 3640 /* 3641 * Do not allow privileged processes in jail to directly 3642 * manipulate system attributes. 3643 * 3644 * XXX What capability should apply here? 3645 * Probably CAP_SYS_SETFFLAG. 3646 */ 3647 switch (attrnamespace) { 3648 case EXTATTR_NAMESPACE_SYSTEM: 3649 /* Potentially should be: return (EPERM); */ 3650 return (suser_cred(cred, 0)); 3651 case EXTATTR_NAMESPACE_USER: 3652 return (VOP_ACCESS(vp, access, cred, td)); 3653 default: 3654 return (EPERM); 3655 } 3656} 3657 3658#ifdef DEBUG_VFS_LOCKS 3659/* 3660 * This only exists to supress warnings from unlocked specfs accesses. It is 3661 * no longer ok to have an unlocked VFS. 3662 */ 3663#define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 3664 3665int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3666SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, ""); 3667 3668int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3669SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, ""); 3670 3671int vfs_badlock_print = 1; /* Print lock violations. */ 3672SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, ""); 3673 3674#ifdef KDB 3675int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 3676SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, ""); 3677#endif 3678 3679static void 3680vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3681{ 3682 3683#ifdef KDB 3684 if (vfs_badlock_backtrace) 3685 kdb_backtrace(); 3686#endif 3687 if (vfs_badlock_print) 3688 printf("%s: %p %s\n", str, (void *)vp, msg); 3689 if (vfs_badlock_ddb) 3690 kdb_enter("lock violation"); 3691} 3692 3693void 3694assert_vi_locked(struct vnode *vp, const char *str) 3695{ 3696 3697 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3698 vfs_badlock("interlock is not locked but should be", str, vp); 3699} 3700 3701void 3702assert_vi_unlocked(struct vnode *vp, const char *str) 3703{ 3704 3705 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3706 vfs_badlock("interlock is locked but should not be", str, vp); 3707} 3708 3709void 3710assert_vop_locked(struct vnode *vp, const char *str) 3711{ 3712 3713 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0) 3714 vfs_badlock("is not locked but should be", str, vp); 3715} 3716 3717void 3718assert_vop_unlocked(struct vnode *vp, const char *str) 3719{ 3720 3721 if (vp && !IGNORE_LOCK(vp) && 3722 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 3723 vfs_badlock("is locked but should not be", str, vp); 3724} 3725 3726#if 0 3727void 3728assert_vop_elocked(struct vnode *vp, const char *str) 3729{ 3730 3731 if (vp && !IGNORE_LOCK(vp) && 3732 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 3733 vfs_badlock("is not exclusive locked but should be", str, vp); 3734} 3735 3736void 3737assert_vop_elocked_other(struct vnode *vp, const char *str) 3738{ 3739 3740 if (vp && !IGNORE_LOCK(vp) && 3741 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 3742 vfs_badlock("is not exclusive locked by another thread", 3743 str, vp); 3744} 3745 3746void 3747assert_vop_slocked(struct vnode *vp, const char *str) 3748{ 3749 3750 if (vp && !IGNORE_LOCK(vp) && 3751 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 3752 vfs_badlock("is not locked shared but should be", str, vp); 3753} 3754#endif /* 0 */ 3755 3756void 3757vop_rename_pre(void *ap) 3758{ 3759 struct vop_rename_args *a = ap; 3760 3761 if (a->a_tvp) 3762 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3763 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3764 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3765 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3766 3767 /* Check the source (from). */ 3768 if (a->a_tdvp != a->a_fdvp) 3769 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3770 if (a->a_tvp != a->a_fvp) 3771 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked"); 3772 3773 /* Check the target. */ 3774 if (a->a_tvp) 3775 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3776 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3777} 3778 3779void 3780vop_strategy_pre(void *ap) 3781{ 3782 struct vop_strategy_args *a; 3783 struct buf *bp; 3784 3785 a = ap; 3786 bp = a->a_bp; 3787 3788 /* 3789 * Cluster ops lock their component buffers but not the IO container. 3790 */ 3791 if ((bp->b_flags & B_CLUSTER) != 0) 3792 return; 3793 3794 if (BUF_REFCNT(bp) < 1) { 3795 if (vfs_badlock_print) 3796 printf( 3797 "VOP_STRATEGY: bp is not locked but should be\n"); 3798 if (vfs_badlock_ddb) 3799 kdb_enter("lock violation"); 3800 } 3801} 3802 3803void 3804vop_lookup_pre(void *ap) 3805{ 3806 struct vop_lookup_args *a; 3807 struct vnode *dvp; 3808 3809 a = ap; 3810 dvp = a->a_dvp; 3811 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3812 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3813} 3814 3815void 3816vop_lookup_post(void *ap, int rc) 3817{ 3818 struct vop_lookup_args *a; 3819 struct componentname *cnp; 3820 struct vnode *dvp; 3821 struct vnode *vp; 3822 int flags; 3823 3824 a = ap; 3825 dvp = a->a_dvp; 3826 cnp = a->a_cnp; 3827 vp = *(a->a_vpp); 3828 flags = cnp->cn_flags; 3829 3830 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3831 3832 /* 3833 * If this is the last path component for this lookup and LOCKPARENT 3834 * is set, OR if there is an error the directory has to be locked. 3835 */ 3836 if ((flags & LOCKPARENT) && (flags & ISLASTCN)) 3837 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); 3838 else if (rc != 0) 3839 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); 3840 else if (dvp != vp) 3841 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); 3842 if (flags & PDIRUNLOCK) 3843 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); 3844} 3845 3846void 3847vop_lock_pre(void *ap) 3848{ 3849 struct vop_lock_args *a = ap; 3850 3851 if ((a->a_flags & LK_INTERLOCK) == 0) 3852 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3853 else 3854 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3855} 3856 3857void 3858vop_lock_post(void *ap, int rc) 3859{ 3860 struct vop_lock_args *a = ap; 3861 3862 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3863 if (rc == 0) 3864 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3865} 3866 3867void 3868vop_unlock_pre(void *ap) 3869{ 3870 struct vop_unlock_args *a = ap; 3871 3872 if (a->a_flags & LK_INTERLOCK) 3873 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 3874 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 3875} 3876 3877void 3878vop_unlock_post(void *ap, int rc) 3879{ 3880 struct vop_unlock_args *a = ap; 3881 3882 if (a->a_flags & LK_INTERLOCK) 3883 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 3884} 3885#endif /* DEBUG_VFS_LOCKS */ 3886 3887static struct knlist fs_knlist; 3888 3889static void 3890vfs_event_init(void *arg) 3891{ 3892 knlist_init(&fs_knlist, NULL); 3893} 3894/* XXX - correct order? */ 3895SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 3896 3897void 3898vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused) 3899{ 3900 3901 KNOTE_UNLOCKED(&fs_knlist, event); 3902} 3903 3904static int filt_fsattach(struct knote *kn); 3905static void filt_fsdetach(struct knote *kn); 3906static int filt_fsevent(struct knote *kn, long hint); 3907 3908struct filterops fs_filtops = 3909 { 0, filt_fsattach, filt_fsdetach, filt_fsevent }; 3910 3911static int 3912filt_fsattach(struct knote *kn) 3913{ 3914 3915 kn->kn_flags |= EV_CLEAR; 3916 knlist_add(&fs_knlist, kn, 0); 3917 return (0); 3918} 3919 3920static void 3921filt_fsdetach(struct knote *kn) 3922{ 3923 3924 knlist_remove(&fs_knlist, kn, 0); 3925} 3926 3927static int 3928filt_fsevent(struct knote *kn, long hint) 3929{ 3930 3931 kn->kn_fflags |= hint; 3932 return (kn->kn_fflags != 0); 3933} 3934 3935static int 3936sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 3937{ 3938 struct vfsidctl vc; 3939 int error; 3940 struct mount *mp; 3941 3942 error = SYSCTL_IN(req, &vc, sizeof(vc)); 3943 if (error) 3944 return (error); 3945 if (vc.vc_vers != VFS_CTL_VERS1) 3946 return (EINVAL); 3947 mp = vfs_getvfs(&vc.vc_fsid); 3948 if (mp == NULL) 3949 return (ENOENT); 3950 /* ensure that a specific sysctl goes to the right filesystem. */ 3951 if (strcmp(vc.vc_fstypename, "*") != 0 && 3952 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 3953 return (EINVAL); 3954 } 3955 VCTLTOREQ(&vc, req); 3956 return (VFS_SYSCTL(mp, vc.vc_op, req)); 3957} 3958 3959SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, 3960 NULL, 0, sysctl_vfs_ctl, "", "Sysctl by fsid"); 3961 3962/* 3963 * Function to initialize a va_filerev field sensibly. 3964 * XXX: Wouldn't a random number make a lot more sense ?? 3965 */ 3966u_quad_t 3967init_va_filerev(void) 3968{ 3969 struct bintime bt; 3970 3971 getbinuptime(&bt); 3972 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 3973} 3974