vfs_subr.c revision 114945
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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 39 * $FreeBSD: head/sys/kern/vfs_subr.c 114945 2003-05-12 14:37:47Z rwatson $ 40 */ 41 42/* 43 * External virtual filesystem routines 44 */ 45#include "opt_ddb.h" 46#include "opt_mac.h" 47 48#include <sys/param.h> 49#include <sys/systm.h> 50#include <sys/bio.h> 51#include <sys/buf.h> 52#include <sys/conf.h> 53#include <sys/eventhandler.h> 54#include <sys/extattr.h> 55#include <sys/fcntl.h> 56#include <sys/kernel.h> 57#include <sys/kthread.h> 58#include <sys/mac.h> 59#include <sys/malloc.h> 60#include <sys/mount.h> 61#include <sys/namei.h> 62#include <sys/stat.h> 63#include <sys/sysctl.h> 64#include <sys/syslog.h> 65#include <sys/vmmeter.h> 66#include <sys/vnode.h> 67 68#include <vm/vm.h> 69#include <vm/vm_object.h> 70#include <vm/vm_extern.h> 71#include <vm/pmap.h> 72#include <vm/vm_map.h> 73#include <vm/vm_page.h> 74#include <vm/uma.h> 75 76static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 77 78static void addalias(struct vnode *vp, dev_t nvp_rdev); 79static void insmntque(struct vnode *vp, struct mount *mp); 80static void vclean(struct vnode *vp, int flags, struct thread *td); 81static void vlruvp(struct vnode *vp); 82static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, 83 int slpflag, int slptimeo, int *errorp); 84static int vcanrecycle(struct vnode *vp, struct mount **vnmpp); 85 86 87/* 88 * Number of vnodes in existence. Increased whenever getnewvnode() 89 * allocates a new vnode, never decreased. 90 */ 91static unsigned long numvnodes; 92 93SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 94 95/* 96 * Conversion tables for conversion from vnode types to inode formats 97 * and back. 98 */ 99enum vtype iftovt_tab[16] = { 100 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 101 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 102}; 103int vttoif_tab[9] = { 104 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 105 S_IFSOCK, S_IFIFO, S_IFMT, 106}; 107 108/* 109 * List of vnodes that are ready for recycling. 110 */ 111static TAILQ_HEAD(freelst, vnode) vnode_free_list; 112 113/* 114 * Minimum number of free vnodes. If there are fewer than this free vnodes, 115 * getnewvnode() will return a newly allocated vnode. 116 */ 117static u_long wantfreevnodes = 25; 118SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 119/* Number of vnodes in the free list. */ 120static u_long freevnodes; 121SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 122 123/* 124 * Various variables used for debugging the new implementation of 125 * reassignbuf(). 126 * XXX these are probably of (very) limited utility now. 127 */ 128static int reassignbufcalls; 129SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 130static int nameileafonly; 131SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 132 133/* 134 * Cache for the mount type id assigned to NFS. This is used for 135 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 136 */ 137int nfs_mount_type = -1; 138 139/* To keep more than one thread at a time from running vfs_getnewfsid */ 140static struct mtx mntid_mtx; 141 142/* 143 * Lock for any access to the following: 144 * vnode_free_list 145 * numvnodes 146 * freevnodes 147 */ 148static struct mtx vnode_free_list_mtx; 149 150/* 151 * For any iteration/modification of dev->si_hlist (linked through 152 * v_specnext) 153 */ 154static struct mtx spechash_mtx; 155 156/* Publicly exported FS */ 157struct nfs_public nfs_pub; 158 159/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 160static uma_zone_t vnode_zone; 161static uma_zone_t vnodepoll_zone; 162 163/* Set to 1 to print out reclaim of active vnodes */ 164int prtactive; 165 166/* 167 * The workitem queue. 168 * 169 * It is useful to delay writes of file data and filesystem metadata 170 * for tens of seconds so that quickly created and deleted files need 171 * not waste disk bandwidth being created and removed. To realize this, 172 * we append vnodes to a "workitem" queue. When running with a soft 173 * updates implementation, most pending metadata dependencies should 174 * not wait for more than a few seconds. Thus, mounted on block devices 175 * are delayed only about a half the time that file data is delayed. 176 * Similarly, directory updates are more critical, so are only delayed 177 * about a third the time that file data is delayed. Thus, there are 178 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 179 * one each second (driven off the filesystem syncer process). The 180 * syncer_delayno variable indicates the next queue that is to be processed. 181 * Items that need to be processed soon are placed in this queue: 182 * 183 * syncer_workitem_pending[syncer_delayno] 184 * 185 * A delay of fifteen seconds is done by placing the request fifteen 186 * entries later in the queue: 187 * 188 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 189 * 190 */ 191static int syncer_delayno; 192static long syncer_mask; 193LIST_HEAD(synclist, vnode); 194static struct synclist *syncer_workitem_pending; 195/* 196 * The sync_mtx protects: 197 * vp->v_synclist 198 * syncer_delayno 199 * syncer_workitem_pending 200 * rushjob 201 */ 202static struct mtx sync_mtx; 203 204#define SYNCER_MAXDELAY 32 205static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 206static int syncdelay = 30; /* max time to delay syncing data */ 207static int filedelay = 30; /* time to delay syncing files */ 208SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 209static int dirdelay = 29; /* time to delay syncing directories */ 210SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 211static int metadelay = 28; /* time to delay syncing metadata */ 212SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 213static int rushjob; /* number of slots to run ASAP */ 214static int stat_rush_requests; /* number of times I/O speeded up */ 215SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 216 217/* 218 * Number of vnodes we want to exist at any one time. This is mostly used 219 * to size hash tables in vnode-related code. It is normally not used in 220 * getnewvnode(), as wantfreevnodes is normally nonzero.) 221 * 222 * XXX desiredvnodes is historical cruft and should not exist. 223 */ 224int desiredvnodes; 225SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 226 &desiredvnodes, 0, "Maximum number of vnodes"); 227static int minvnodes; 228SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 229 &minvnodes, 0, "Minimum number of vnodes"); 230static int vnlru_nowhere; 231SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0, 232 "Number of times the vnlru process ran without success"); 233 234/* Hook for calling soft updates */ 235int (*softdep_process_worklist_hook)(struct mount *); 236 237/* 238 * This only exists to supress warnings from unlocked specfs accesses. It is 239 * no longer ok to have an unlocked VFS. 240 */ 241#define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 242 243/* Print lock violations */ 244int vfs_badlock_print = 1; 245 246/* Panic on violation */ 247int vfs_badlock_panic = 1; 248 249/* Check for interlock across VOPs */ 250int vfs_badlock_mutex = 1; 251 252static void 253vfs_badlock(char *msg, char *str, struct vnode *vp) 254{ 255 if (vfs_badlock_print) 256 printf("%s: %p %s\n", str, vp, msg); 257 if (vfs_badlock_panic) 258 Debugger("Lock violation.\n"); 259} 260 261void 262assert_vi_unlocked(struct vnode *vp, char *str) 263{ 264 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 265 vfs_badlock("interlock is locked but should not be", str, vp); 266} 267 268void 269assert_vi_locked(struct vnode *vp, char *str) 270{ 271 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 272 vfs_badlock("interlock is not locked but should be", str, vp); 273} 274 275void 276assert_vop_locked(struct vnode *vp, char *str) 277{ 278 if (vp && !IGNORE_LOCK(vp) && !VOP_ISLOCKED(vp, NULL)) 279 vfs_badlock("is not locked but should be", str, vp); 280} 281 282void 283assert_vop_unlocked(struct vnode *vp, char *str) 284{ 285 if (vp && !IGNORE_LOCK(vp) && 286 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 287 vfs_badlock("is locked but should not be", str, vp); 288} 289 290void 291assert_vop_elocked(struct vnode *vp, char *str) 292{ 293 if (vp && !IGNORE_LOCK(vp) && 294 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 295 vfs_badlock("is not exclusive locked but should be", str, vp); 296} 297 298void 299assert_vop_elocked_other(struct vnode *vp, char *str) 300{ 301 if (vp && !IGNORE_LOCK(vp) && 302 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 303 vfs_badlock("is not exclusive locked by another thread", 304 str, vp); 305} 306 307void 308assert_vop_slocked(struct vnode *vp, char *str) 309{ 310 if (vp && !IGNORE_LOCK(vp) && 311 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 312 vfs_badlock("is not locked shared but should be", str, vp); 313} 314 315void 316vop_rename_pre(void *ap) 317{ 318 struct vop_rename_args *a = ap; 319 320 if (a->a_tvp) 321 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 322 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 323 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 324 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 325 326 /* Check the source (from) */ 327 if (a->a_tdvp != a->a_fdvp) 328 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked.\n"); 329 if (a->a_tvp != a->a_fvp) 330 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked.\n"); 331 332 /* Check the target */ 333 if (a->a_tvp) 334 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked.\n"); 335 336 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked.\n"); 337} 338 339void 340vop_strategy_pre(void *ap) 341{ 342 struct vop_strategy_args *a = ap; 343 struct buf *bp; 344 345 bp = a->a_bp; 346 347 /* 348 * Cluster ops lock their component buffers but not the IO container. 349 */ 350 if ((bp->b_flags & B_CLUSTER) != 0) 351 return; 352 353 if (BUF_REFCNT(bp) < 1) { 354 if (vfs_badlock_print) 355 printf("VOP_STRATEGY: bp is not locked but should be.\n"); 356 if (vfs_badlock_panic) 357 Debugger("Lock violation.\n"); 358 } 359} 360 361void 362vop_lookup_pre(void *ap) 363{ 364 struct vop_lookup_args *a = ap; 365 struct vnode *dvp; 366 367 dvp = a->a_dvp; 368 369 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 370 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 371} 372 373void 374vop_lookup_post(void *ap, int rc) 375{ 376 struct vop_lookup_args *a = ap; 377 struct componentname *cnp; 378 struct vnode *dvp; 379 struct vnode *vp; 380 int flags; 381 382 dvp = a->a_dvp; 383 cnp = a->a_cnp; 384 vp = *(a->a_vpp); 385 flags = cnp->cn_flags; 386 387 388 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 389 /* 390 * If this is the last path component for this lookup and LOCPARENT 391 * is set, OR if there is an error the directory has to be locked. 392 */ 393 if ((flags & LOCKPARENT) && (flags & ISLASTCN)) 394 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); 395 else if (rc != 0) 396 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); 397 else if (dvp != vp) 398 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); 399 400 if (flags & PDIRUNLOCK) 401 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); 402} 403 404void 405vop_unlock_pre(void *ap) 406{ 407 struct vop_unlock_args *a = ap; 408 409 if (a->a_flags & LK_INTERLOCK) 410 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 411 412 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 413} 414 415void 416vop_unlock_post(void *ap, int rc) 417{ 418 struct vop_unlock_args *a = ap; 419 420 if (a->a_flags & LK_INTERLOCK) 421 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 422} 423 424void 425vop_lock_pre(void *ap) 426{ 427 struct vop_lock_args *a = ap; 428 429 if ((a->a_flags & LK_INTERLOCK) == 0) 430 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 431 else 432 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 433} 434 435void 436vop_lock_post(void *ap, int rc) 437{ 438 struct vop_lock_args *a; 439 440 a = ap; 441 442 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 443 if (rc == 0) 444 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 445} 446 447void 448v_addpollinfo(struct vnode *vp) 449{ 450 vp->v_pollinfo = uma_zalloc(vnodepoll_zone, M_WAITOK); 451 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 452} 453 454/* 455 * Initialize the vnode management data structures. 456 */ 457static void 458vntblinit(void *dummy __unused) 459{ 460 461 desiredvnodes = maxproc + cnt.v_page_count / 4; 462 minvnodes = desiredvnodes / 4; 463 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 464 mtx_init(&mntvnode_mtx, "mntvnode", NULL, MTX_DEF); 465 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 466 mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); 467 TAILQ_INIT(&vnode_free_list); 468 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 469 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 470 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 471 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 472 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 473 /* 474 * Initialize the filesystem syncer. 475 */ 476 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 477 &syncer_mask); 478 syncer_maxdelay = syncer_mask + 1; 479 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 480} 481SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 482 483 484/* 485 * Mark a mount point as busy. Used to synchronize access and to delay 486 * unmounting. Interlock is not released on failure. 487 */ 488int 489vfs_busy(mp, flags, interlkp, td) 490 struct mount *mp; 491 int flags; 492 struct mtx *interlkp; 493 struct thread *td; 494{ 495 int lkflags; 496 497 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 498 if (flags & LK_NOWAIT) 499 return (ENOENT); 500 mp->mnt_kern_flag |= MNTK_MWAIT; 501 /* 502 * Since all busy locks are shared except the exclusive 503 * lock granted when unmounting, the only place that a 504 * wakeup needs to be done is at the release of the 505 * exclusive lock at the end of dounmount. 506 */ 507 msleep(mp, interlkp, PVFS, "vfs_busy", 0); 508 return (ENOENT); 509 } 510 lkflags = LK_SHARED | LK_NOPAUSE; 511 if (interlkp) 512 lkflags |= LK_INTERLOCK; 513 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 514 panic("vfs_busy: unexpected lock failure"); 515 return (0); 516} 517 518/* 519 * Free a busy filesystem. 520 */ 521void 522vfs_unbusy(mp, td) 523 struct mount *mp; 524 struct thread *td; 525{ 526 527 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 528} 529 530/* 531 * Lookup a mount point by filesystem identifier. 532 */ 533struct mount * 534vfs_getvfs(fsid) 535 fsid_t *fsid; 536{ 537 register struct mount *mp; 538 539 mtx_lock(&mountlist_mtx); 540 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 541 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 542 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 543 mtx_unlock(&mountlist_mtx); 544 return (mp); 545 } 546 } 547 mtx_unlock(&mountlist_mtx); 548 return ((struct mount *) 0); 549} 550 551/* 552 * Get a new unique fsid. Try to make its val[0] unique, since this value 553 * will be used to create fake device numbers for stat(). Also try (but 554 * not so hard) make its val[0] unique mod 2^16, since some emulators only 555 * support 16-bit device numbers. We end up with unique val[0]'s for the 556 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 557 * 558 * Keep in mind that several mounts may be running in parallel. Starting 559 * the search one past where the previous search terminated is both a 560 * micro-optimization and a defense against returning the same fsid to 561 * different mounts. 562 */ 563void 564vfs_getnewfsid(mp) 565 struct mount *mp; 566{ 567 static u_int16_t mntid_base; 568 fsid_t tfsid; 569 int mtype; 570 571 mtx_lock(&mntid_mtx); 572 mtype = mp->mnt_vfc->vfc_typenum; 573 tfsid.val[1] = mtype; 574 mtype = (mtype & 0xFF) << 24; 575 for (;;) { 576 tfsid.val[0] = makeudev(255, 577 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 578 mntid_base++; 579 if (vfs_getvfs(&tfsid) == NULL) 580 break; 581 } 582 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 583 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 584 mtx_unlock(&mntid_mtx); 585} 586 587/* 588 * Knob to control the precision of file timestamps: 589 * 590 * 0 = seconds only; nanoseconds zeroed. 591 * 1 = seconds and nanoseconds, accurate within 1/HZ. 592 * 2 = seconds and nanoseconds, truncated to microseconds. 593 * >=3 = seconds and nanoseconds, maximum precision. 594 */ 595enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 596 597static int timestamp_precision = TSP_SEC; 598SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 599 ×tamp_precision, 0, ""); 600 601/* 602 * Get a current timestamp. 603 */ 604void 605vfs_timestamp(tsp) 606 struct timespec *tsp; 607{ 608 struct timeval tv; 609 610 switch (timestamp_precision) { 611 case TSP_SEC: 612 tsp->tv_sec = time_second; 613 tsp->tv_nsec = 0; 614 break; 615 case TSP_HZ: 616 getnanotime(tsp); 617 break; 618 case TSP_USEC: 619 microtime(&tv); 620 TIMEVAL_TO_TIMESPEC(&tv, tsp); 621 break; 622 case TSP_NSEC: 623 default: 624 nanotime(tsp); 625 break; 626 } 627} 628 629/* 630 * Set vnode attributes to VNOVAL 631 */ 632void 633vattr_null(vap) 634 register struct vattr *vap; 635{ 636 637 vap->va_type = VNON; 638 vap->va_size = VNOVAL; 639 vap->va_bytes = VNOVAL; 640 vap->va_mode = VNOVAL; 641 vap->va_nlink = VNOVAL; 642 vap->va_uid = VNOVAL; 643 vap->va_gid = VNOVAL; 644 vap->va_fsid = VNOVAL; 645 vap->va_fileid = VNOVAL; 646 vap->va_blocksize = VNOVAL; 647 vap->va_rdev = VNOVAL; 648 vap->va_atime.tv_sec = VNOVAL; 649 vap->va_atime.tv_nsec = VNOVAL; 650 vap->va_mtime.tv_sec = VNOVAL; 651 vap->va_mtime.tv_nsec = VNOVAL; 652 vap->va_ctime.tv_sec = VNOVAL; 653 vap->va_ctime.tv_nsec = VNOVAL; 654 vap->va_birthtime.tv_sec = VNOVAL; 655 vap->va_birthtime.tv_nsec = VNOVAL; 656 vap->va_flags = VNOVAL; 657 vap->va_gen = VNOVAL; 658 vap->va_vaflags = 0; 659} 660 661/* 662 * This routine is called when we have too many vnodes. It attempts 663 * to free <count> vnodes and will potentially free vnodes that still 664 * have VM backing store (VM backing store is typically the cause 665 * of a vnode blowout so we want to do this). Therefore, this operation 666 * is not considered cheap. 667 * 668 * A number of conditions may prevent a vnode from being reclaimed. 669 * the buffer cache may have references on the vnode, a directory 670 * vnode may still have references due to the namei cache representing 671 * underlying files, or the vnode may be in active use. It is not 672 * desireable to reuse such vnodes. These conditions may cause the 673 * number of vnodes to reach some minimum value regardless of what 674 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 675 */ 676static int 677vlrureclaim(struct mount *mp) 678{ 679 struct vnode *vp; 680 int done; 681 int trigger; 682 int usevnodes; 683 int count; 684 685 /* 686 * Calculate the trigger point, don't allow user 687 * screwups to blow us up. This prevents us from 688 * recycling vnodes with lots of resident pages. We 689 * aren't trying to free memory, we are trying to 690 * free vnodes. 691 */ 692 usevnodes = desiredvnodes; 693 if (usevnodes <= 0) 694 usevnodes = 1; 695 trigger = cnt.v_page_count * 2 / usevnodes; 696 697 done = 0; 698 mtx_lock(&mntvnode_mtx); 699 count = mp->mnt_nvnodelistsize / 10 + 1; 700 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 701 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 702 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 703 704 if (vp->v_type != VNON && 705 vp->v_type != VBAD && 706 VI_TRYLOCK(vp)) { 707 if (VMIGHTFREE(vp) && /* critical path opt */ 708 (vp->v_object == NULL || 709 vp->v_object->resident_page_count < trigger)) { 710 mtx_unlock(&mntvnode_mtx); 711 vgonel(vp, curthread); 712 done++; 713 mtx_lock(&mntvnode_mtx); 714 } else 715 VI_UNLOCK(vp); 716 } 717 --count; 718 } 719 mtx_unlock(&mntvnode_mtx); 720 return done; 721} 722 723/* 724 * Attempt to recycle vnodes in a context that is always safe to block. 725 * Calling vlrurecycle() from the bowels of filesystem code has some 726 * interesting deadlock problems. 727 */ 728static struct proc *vnlruproc; 729static int vnlruproc_sig; 730 731static void 732vnlru_proc(void) 733{ 734 struct mount *mp, *nmp; 735 int s; 736 int done; 737 struct proc *p = vnlruproc; 738 struct thread *td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ 739 740 mtx_lock(&Giant); 741 742 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 743 SHUTDOWN_PRI_FIRST); 744 745 s = splbio(); 746 for (;;) { 747 kthread_suspend_check(p); 748 mtx_lock(&vnode_free_list_mtx); 749 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 750 mtx_unlock(&vnode_free_list_mtx); 751 vnlruproc_sig = 0; 752 wakeup(&vnlruproc_sig); 753 tsleep(vnlruproc, PVFS, "vlruwt", hz); 754 continue; 755 } 756 mtx_unlock(&vnode_free_list_mtx); 757 done = 0; 758 mtx_lock(&mountlist_mtx); 759 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 760 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 761 nmp = TAILQ_NEXT(mp, mnt_list); 762 continue; 763 } 764 done += vlrureclaim(mp); 765 mtx_lock(&mountlist_mtx); 766 nmp = TAILQ_NEXT(mp, mnt_list); 767 vfs_unbusy(mp, td); 768 } 769 mtx_unlock(&mountlist_mtx); 770 if (done == 0) { 771#if 0 772 /* These messages are temporary debugging aids */ 773 if (vnlru_nowhere < 5) 774 printf("vnlru process getting nowhere..\n"); 775 else if (vnlru_nowhere == 5) 776 printf("vnlru process messages stopped.\n"); 777#endif 778 vnlru_nowhere++; 779 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 780 } 781 } 782 splx(s); 783} 784 785static struct kproc_desc vnlru_kp = { 786 "vnlru", 787 vnlru_proc, 788 &vnlruproc 789}; 790SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 791 792 793/* 794 * Routines having to do with the management of the vnode table. 795 */ 796 797/* 798 * Check to see if a free vnode can be recycled. If it can, 799 * return it locked with the vn lock, but not interlock. Also 800 * get the vn_start_write lock. Otherwise indicate the error. 801 */ 802static int 803vcanrecycle(struct vnode *vp, struct mount **vnmpp) 804{ 805 struct thread *td = curthread; 806 vm_object_t object; 807 int error; 808 809 /* Don't recycle if we can't get the interlock */ 810 if (!VI_TRYLOCK(vp)) 811 return (EWOULDBLOCK); 812 813 /* We should be able to immediately acquire this */ 814 /* XXX This looks like it should panic if it fails */ 815 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td) != 0) { 816 if (VOP_ISLOCKED(vp, td)) 817 panic("vcanrecycle: locked vnode"); 818 return (EWOULDBLOCK); 819 } 820 821 /* 822 * Don't recycle if its filesystem is being suspended. 823 */ 824 if (vn_start_write(vp, vnmpp, V_NOWAIT) != 0) { 825 error = EBUSY; 826 goto done; 827 } 828 829 /* 830 * Don't recycle if we still have cached pages. 831 */ 832 if (VOP_GETVOBJECT(vp, &object) == 0) { 833 VM_OBJECT_LOCK(object); 834 if (object->resident_page_count || 835 object->ref_count) { 836 VM_OBJECT_UNLOCK(object); 837 error = EBUSY; 838 goto done; 839 } 840 VM_OBJECT_UNLOCK(object); 841 } 842 if (LIST_FIRST(&vp->v_cache_src)) { 843 /* 844 * note: nameileafonly sysctl is temporary, 845 * for debugging only, and will eventually be 846 * removed. 847 */ 848 if (nameileafonly > 0) { 849 /* 850 * Do not reuse namei-cached directory 851 * vnodes that have cached 852 * subdirectories. 853 */ 854 if (cache_leaf_test(vp) < 0) { 855 error = EISDIR; 856 goto done; 857 } 858 } else if (nameileafonly < 0 || 859 vmiodirenable == 0) { 860 /* 861 * Do not reuse namei-cached directory 862 * vnodes if nameileafonly is -1 or 863 * if VMIO backing for directories is 864 * turned off (otherwise we reuse them 865 * too quickly). 866 */ 867 error = EBUSY; 868 goto done; 869 } 870 } 871 return (0); 872done: 873 VOP_UNLOCK(vp, 0, td); 874 return (error); 875} 876 877/* 878 * Return the next vnode from the free list. 879 */ 880int 881getnewvnode(tag, mp, vops, vpp) 882 const char *tag; 883 struct mount *mp; 884 vop_t **vops; 885 struct vnode **vpp; 886{ 887 int s; 888 struct thread *td = curthread; /* XXX */ 889 struct vnode *vp = NULL; 890 struct vpollinfo *pollinfo = NULL; 891 struct mount *vnmp; 892 893 s = splbio(); 894 mtx_lock(&vnode_free_list_mtx); 895 896 /* 897 * Try to reuse vnodes if we hit the max. This situation only 898 * occurs in certain large-memory (2G+) situations. We cannot 899 * attempt to directly reclaim vnodes due to nasty recursion 900 * problems. 901 */ 902 while (numvnodes - freevnodes > desiredvnodes) { 903 if (vnlruproc_sig == 0) { 904 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 905 wakeup(vnlruproc); 906 } 907 mtx_unlock(&vnode_free_list_mtx); 908 tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); 909 mtx_lock(&vnode_free_list_mtx); 910 } 911 912 /* 913 * Attempt to reuse a vnode already on the free list, allocating 914 * a new vnode if we can't find one or if we have not reached a 915 * good minimum for good LRU performance. 916 */ 917 918 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 919 int error; 920 int count; 921 922 for (count = 0; count < freevnodes; count++) { 923 vp = TAILQ_FIRST(&vnode_free_list); 924 925 KASSERT(vp->v_usecount == 0 && 926 (vp->v_iflag & VI_DOINGINACT) == 0, 927 ("getnewvnode: free vnode isn't")); 928 929 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 930 /* 931 * We have to drop the free list mtx to avoid lock 932 * order reversals with interlock. 933 */ 934 mtx_unlock(&vnode_free_list_mtx); 935 error = vcanrecycle(vp, &vnmp); 936 mtx_lock(&vnode_free_list_mtx); 937 if (error == 0) 938 break; 939 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 940 vp = NULL; 941 } 942 } 943 if (vp) { 944 freevnodes--; 945 mtx_unlock(&vnode_free_list_mtx); 946 947 cache_purge(vp); 948 VI_LOCK(vp); 949 vp->v_iflag |= VI_DOOMED; 950 vp->v_iflag &= ~VI_FREE; 951 if (vp->v_type != VBAD) { 952 VOP_UNLOCK(vp, 0, td); 953 vgonel(vp, td); 954 VI_LOCK(vp); 955 } else { 956 VOP_UNLOCK(vp, 0, td); 957 } 958 vn_finished_write(vnmp); 959 960#ifdef INVARIANTS 961 { 962 if (vp->v_data) 963 panic("cleaned vnode isn't"); 964 if (vp->v_numoutput) 965 panic("Clean vnode has pending I/O's"); 966 if (vp->v_writecount != 0) 967 panic("Non-zero write count"); 968 } 969#endif 970 if ((pollinfo = vp->v_pollinfo) != NULL) { 971 /* 972 * To avoid lock order reversals, the call to 973 * uma_zfree() must be delayed until the vnode 974 * interlock is released. 975 */ 976 vp->v_pollinfo = NULL; 977 } 978#ifdef MAC 979 mac_destroy_vnode(vp); 980#endif 981 vp->v_iflag = 0; 982 vp->v_vflag = 0; 983 vp->v_lastw = 0; 984 vp->v_lasta = 0; 985 vp->v_cstart = 0; 986 vp->v_clen = 0; 987 vp->v_socket = 0; 988 lockdestroy(vp->v_vnlock); 989 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 990 KASSERT(vp->v_cleanbufcnt == 0, ("cleanbufcnt not 0")); 991 KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); 992 KASSERT(vp->v_dirtybufcnt == 0, ("dirtybufcnt not 0")); 993 KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); 994 } else { 995 numvnodes++; 996 mtx_unlock(&vnode_free_list_mtx); 997 998 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 999 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 1000 VI_LOCK(vp); 1001 vp->v_dd = vp; 1002 vp->v_vnlock = &vp->v_lock; 1003 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 1004 cache_purge(vp); 1005 LIST_INIT(&vp->v_cache_src); 1006 TAILQ_INIT(&vp->v_cache_dst); 1007 } 1008 1009 TAILQ_INIT(&vp->v_cleanblkhd); 1010 TAILQ_INIT(&vp->v_dirtyblkhd); 1011 vp->v_type = VNON; 1012 vp->v_tag = tag; 1013 vp->v_op = vops; 1014 *vpp = vp; 1015 vp->v_usecount = 1; 1016 vp->v_data = 0; 1017 vp->v_cachedid = -1; 1018 VI_UNLOCK(vp); 1019 if (pollinfo != NULL) { 1020 mtx_destroy(&pollinfo->vpi_lock); 1021 uma_zfree(vnodepoll_zone, pollinfo); 1022 } 1023#ifdef MAC 1024 mac_init_vnode(vp); 1025 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1026 mac_associate_vnode_singlelabel(mp, vp); 1027#endif 1028 insmntque(vp, mp); 1029 1030 return (0); 1031} 1032 1033/* 1034 * Move a vnode from one mount queue to another. 1035 */ 1036static void 1037insmntque(vp, mp) 1038 register struct vnode *vp; 1039 register struct mount *mp; 1040{ 1041 1042 mtx_lock(&mntvnode_mtx); 1043 /* 1044 * Delete from old mount point vnode list, if on one. 1045 */ 1046 if (vp->v_mount != NULL) { 1047 KASSERT(vp->v_mount->mnt_nvnodelistsize > 0, 1048 ("bad mount point vnode list size")); 1049 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 1050 vp->v_mount->mnt_nvnodelistsize--; 1051 } 1052 /* 1053 * Insert into list of vnodes for the new mount point, if available. 1054 */ 1055 if ((vp->v_mount = mp) == NULL) { 1056 mtx_unlock(&mntvnode_mtx); 1057 return; 1058 } 1059 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1060 mp->mnt_nvnodelistsize++; 1061 mtx_unlock(&mntvnode_mtx); 1062} 1063 1064/* 1065 * Update outstanding I/O count and do wakeup if requested. 1066 */ 1067void 1068vwakeup(bp) 1069 register struct buf *bp; 1070{ 1071 register struct vnode *vp; 1072 1073 bp->b_flags &= ~B_WRITEINPROG; 1074 if ((vp = bp->b_vp)) { 1075 VI_LOCK(vp); 1076 vp->v_numoutput--; 1077 if (vp->v_numoutput < 0) 1078 panic("vwakeup: neg numoutput"); 1079 if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) { 1080 vp->v_iflag &= ~VI_BWAIT; 1081 wakeup(&vp->v_numoutput); 1082 } 1083 VI_UNLOCK(vp); 1084 } 1085} 1086 1087/* 1088 * Flush out and invalidate all buffers associated with a vnode. 1089 * Called with the underlying object locked. 1090 */ 1091int 1092vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 1093 struct vnode *vp; 1094 int flags; 1095 struct ucred *cred; 1096 struct thread *td; 1097 int slpflag, slptimeo; 1098{ 1099 struct buf *blist; 1100 int s, error; 1101 vm_object_t object; 1102 1103 GIANT_REQUIRED; 1104 1105 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1106 1107 VI_LOCK(vp); 1108 if (flags & V_SAVE) { 1109 s = splbio(); 1110 while (vp->v_numoutput) { 1111 vp->v_iflag |= VI_BWAIT; 1112 error = msleep(&vp->v_numoutput, VI_MTX(vp), 1113 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 1114 if (error) { 1115 VI_UNLOCK(vp); 1116 splx(s); 1117 return (error); 1118 } 1119 } 1120 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1121 splx(s); 1122 VI_UNLOCK(vp); 1123 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 1124 return (error); 1125 /* 1126 * XXX We could save a lock/unlock if this was only 1127 * enabled under INVARIANTS 1128 */ 1129 VI_LOCK(vp); 1130 s = splbio(); 1131 if (vp->v_numoutput > 0 || 1132 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 1133 panic("vinvalbuf: dirty bufs"); 1134 } 1135 splx(s); 1136 } 1137 s = splbio(); 1138 /* 1139 * If you alter this loop please notice that interlock is dropped and 1140 * reacquired in flushbuflist. Special care is needed to ensure that 1141 * no race conditions occur from this. 1142 */ 1143 for (error = 0;;) { 1144 if ((blist = TAILQ_FIRST(&vp->v_cleanblkhd)) != 0 && 1145 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 1146 if (error) 1147 break; 1148 continue; 1149 } 1150 if ((blist = TAILQ_FIRST(&vp->v_dirtyblkhd)) != 0 && 1151 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 1152 if (error) 1153 break; 1154 continue; 1155 } 1156 break; 1157 } 1158 if (error) { 1159 splx(s); 1160 VI_UNLOCK(vp); 1161 return (error); 1162 } 1163 1164 /* 1165 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1166 * have write I/O in-progress but if there is a VM object then the 1167 * VM object can also have read-I/O in-progress. 1168 */ 1169 do { 1170 while (vp->v_numoutput > 0) { 1171 vp->v_iflag |= VI_BWAIT; 1172 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0); 1173 } 1174 VI_UNLOCK(vp); 1175 if (VOP_GETVOBJECT(vp, &object) == 0) { 1176 VM_OBJECT_LOCK(object); 1177 vm_object_pip_wait(object, "vnvlbx"); 1178 VM_OBJECT_UNLOCK(object); 1179 } 1180 VI_LOCK(vp); 1181 } while (vp->v_numoutput > 0); 1182 VI_UNLOCK(vp); 1183 1184 splx(s); 1185 1186 /* 1187 * Destroy the copy in the VM cache, too. 1188 */ 1189 if (VOP_GETVOBJECT(vp, &object) == 0) { 1190 VM_OBJECT_LOCK(object); 1191 vm_object_page_remove(object, 0, 0, 1192 (flags & V_SAVE) ? TRUE : FALSE); 1193 VM_OBJECT_UNLOCK(object); 1194 } 1195 1196#ifdef INVARIANTS 1197 VI_LOCK(vp); 1198 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1199 (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || 1200 !TAILQ_EMPTY(&vp->v_cleanblkhd))) 1201 panic("vinvalbuf: flush failed"); 1202 VI_UNLOCK(vp); 1203#endif 1204 return (0); 1205} 1206 1207/* 1208 * Flush out buffers on the specified list. 1209 * 1210 */ 1211static int 1212flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) 1213 struct buf *blist; 1214 int flags; 1215 struct vnode *vp; 1216 int slpflag, slptimeo; 1217 int *errorp; 1218{ 1219 struct buf *bp, *nbp; 1220 int found, error; 1221 1222 ASSERT_VI_LOCKED(vp, "flushbuflist"); 1223 1224 for (found = 0, bp = blist; bp; bp = nbp) { 1225 nbp = TAILQ_NEXT(bp, b_vnbufs); 1226 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1227 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1228 continue; 1229 } 1230 found += 1; 1231 error = BUF_TIMELOCK(bp, 1232 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), 1233 "flushbuf", slpflag, slptimeo); 1234 if (error) { 1235 if (error != ENOLCK) 1236 *errorp = error; 1237 goto done; 1238 } 1239 /* 1240 * XXX Since there are no node locks for NFS, I 1241 * believe there is a slight chance that a delayed 1242 * write will occur while sleeping just above, so 1243 * check for it. Note that vfs_bio_awrite expects 1244 * buffers to reside on a queue, while BUF_WRITE and 1245 * brelse do not. 1246 */ 1247 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1248 (flags & V_SAVE)) { 1249 1250 if (bp->b_vp == vp) { 1251 if (bp->b_flags & B_CLUSTEROK) { 1252 vfs_bio_awrite(bp); 1253 } else { 1254 bremfree(bp); 1255 bp->b_flags |= B_ASYNC; 1256 BUF_WRITE(bp); 1257 } 1258 } else { 1259 bremfree(bp); 1260 (void) BUF_WRITE(bp); 1261 } 1262 goto done; 1263 } 1264 bremfree(bp); 1265 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1266 bp->b_flags &= ~B_ASYNC; 1267 brelse(bp); 1268 VI_LOCK(vp); 1269 } 1270 return (found); 1271done: 1272 VI_LOCK(vp); 1273 return (found); 1274} 1275 1276/* 1277 * Truncate a file's buffer and pages to a specified length. This 1278 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1279 * sync activity. 1280 */ 1281int 1282vtruncbuf(vp, cred, td, length, blksize) 1283 register struct vnode *vp; 1284 struct ucred *cred; 1285 struct thread *td; 1286 off_t length; 1287 int blksize; 1288{ 1289 register struct buf *bp; 1290 struct buf *nbp; 1291 int s, anyfreed; 1292 int trunclbn; 1293 1294 /* 1295 * Round up to the *next* lbn. 1296 */ 1297 trunclbn = (length + blksize - 1) / blksize; 1298 1299 s = splbio(); 1300 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1301restart: 1302 VI_LOCK(vp); 1303 anyfreed = 1; 1304 for (;anyfreed;) { 1305 anyfreed = 0; 1306 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 1307 nbp = TAILQ_NEXT(bp, b_vnbufs); 1308 if (bp->b_lblkno >= trunclbn) { 1309 if (BUF_LOCK(bp, 1310 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1311 VI_MTX(vp)) == ENOLCK) 1312 goto restart; 1313 1314 bremfree(bp); 1315 bp->b_flags |= (B_INVAL | B_RELBUF); 1316 bp->b_flags &= ~B_ASYNC; 1317 brelse(bp); 1318 anyfreed = 1; 1319 1320 if (nbp && 1321 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1322 (nbp->b_vp != vp) || 1323 (nbp->b_flags & B_DELWRI))) { 1324 goto restart; 1325 } 1326 VI_LOCK(vp); 1327 } 1328 } 1329 1330 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1331 nbp = TAILQ_NEXT(bp, b_vnbufs); 1332 if (bp->b_lblkno >= trunclbn) { 1333 if (BUF_LOCK(bp, 1334 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1335 VI_MTX(vp)) == ENOLCK) 1336 goto restart; 1337 bremfree(bp); 1338 bp->b_flags |= (B_INVAL | B_RELBUF); 1339 bp->b_flags &= ~B_ASYNC; 1340 brelse(bp); 1341 anyfreed = 1; 1342 if (nbp && 1343 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1344 (nbp->b_vp != vp) || 1345 (nbp->b_flags & B_DELWRI) == 0)) { 1346 goto restart; 1347 } 1348 VI_LOCK(vp); 1349 } 1350 } 1351 } 1352 1353 if (length > 0) { 1354restartsync: 1355 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1356 nbp = TAILQ_NEXT(bp, b_vnbufs); 1357 if (bp->b_lblkno > 0) 1358 continue; 1359 /* 1360 * Since we hold the vnode lock this should only 1361 * fail if we're racing with the buf daemon. 1362 */ 1363 if (BUF_LOCK(bp, 1364 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1365 VI_MTX(vp)) == ENOLCK) { 1366 goto restart; 1367 } 1368 KASSERT((bp->b_flags & B_DELWRI), 1369 ("buf(%p) on dirty queue without DELWRI.", bp)); 1370 1371 bremfree(bp); 1372 bawrite(bp); 1373 VI_LOCK(vp); 1374 goto restartsync; 1375 } 1376 } 1377 1378 while (vp->v_numoutput > 0) { 1379 vp->v_iflag |= VI_BWAIT; 1380 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0); 1381 } 1382 VI_UNLOCK(vp); 1383 splx(s); 1384 1385 vnode_pager_setsize(vp, length); 1386 1387 return (0); 1388} 1389 1390/* 1391 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1392 * a vnode. 1393 * 1394 * NOTE: We have to deal with the special case of a background bitmap 1395 * buffer, a situation where two buffers will have the same logical 1396 * block offset. We want (1) only the foreground buffer to be accessed 1397 * in a lookup and (2) must differentiate between the foreground and 1398 * background buffer in the splay tree algorithm because the splay 1399 * tree cannot normally handle multiple entities with the same 'index'. 1400 * We accomplish this by adding differentiating flags to the splay tree's 1401 * numerical domain. 1402 */ 1403static 1404struct buf * 1405buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1406{ 1407 struct buf dummy; 1408 struct buf *lefttreemax, *righttreemin, *y; 1409 1410 if (root == NULL) 1411 return (NULL); 1412 lefttreemax = righttreemin = &dummy; 1413 for (;;) { 1414 if (lblkno < root->b_lblkno || 1415 (lblkno == root->b_lblkno && 1416 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1417 if ((y = root->b_left) == NULL) 1418 break; 1419 if (lblkno < y->b_lblkno) { 1420 /* Rotate right. */ 1421 root->b_left = y->b_right; 1422 y->b_right = root; 1423 root = y; 1424 if ((y = root->b_left) == NULL) 1425 break; 1426 } 1427 /* Link into the new root's right tree. */ 1428 righttreemin->b_left = root; 1429 righttreemin = root; 1430 } else if (lblkno > root->b_lblkno || 1431 (lblkno == root->b_lblkno && 1432 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1433 if ((y = root->b_right) == NULL) 1434 break; 1435 if (lblkno > y->b_lblkno) { 1436 /* Rotate left. */ 1437 root->b_right = y->b_left; 1438 y->b_left = root; 1439 root = y; 1440 if ((y = root->b_right) == NULL) 1441 break; 1442 } 1443 /* Link into the new root's left tree. */ 1444 lefttreemax->b_right = root; 1445 lefttreemax = root; 1446 } else { 1447 break; 1448 } 1449 root = y; 1450 } 1451 /* Assemble the new root. */ 1452 lefttreemax->b_right = root->b_left; 1453 righttreemin->b_left = root->b_right; 1454 root->b_left = dummy.b_right; 1455 root->b_right = dummy.b_left; 1456 return (root); 1457} 1458 1459static 1460void 1461buf_vlist_remove(struct buf *bp) 1462{ 1463 struct vnode *vp = bp->b_vp; 1464 struct buf *root; 1465 1466 ASSERT_VI_LOCKED(vp, "buf_vlist_remove"); 1467 if (bp->b_xflags & BX_VNDIRTY) { 1468 if (bp != vp->v_dirtyblkroot) { 1469 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1470 KASSERT(root == bp, ("splay lookup failed during dirty remove")); 1471 } 1472 if (bp->b_left == NULL) { 1473 root = bp->b_right; 1474 } else { 1475 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1476 root->b_right = bp->b_right; 1477 } 1478 vp->v_dirtyblkroot = root; 1479 TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); 1480 vp->v_dirtybufcnt--; 1481 } else { 1482 /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ 1483 if (bp != vp->v_cleanblkroot) { 1484 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1485 KASSERT(root == bp, ("splay lookup failed during clean remove")); 1486 } 1487 if (bp->b_left == NULL) { 1488 root = bp->b_right; 1489 } else { 1490 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1491 root->b_right = bp->b_right; 1492 } 1493 vp->v_cleanblkroot = root; 1494 TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); 1495 vp->v_cleanbufcnt--; 1496 } 1497 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1498} 1499 1500/* 1501 * Add the buffer to the sorted clean or dirty block list using a 1502 * splay tree algorithm. 1503 * 1504 * NOTE: xflags is passed as a constant, optimizing this inline function! 1505 */ 1506static 1507void 1508buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) 1509{ 1510 struct buf *root; 1511 1512 ASSERT_VI_LOCKED(vp, "buf_vlist_add"); 1513 bp->b_xflags |= xflags; 1514 if (xflags & BX_VNDIRTY) { 1515 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1516 if (root == NULL) { 1517 bp->b_left = NULL; 1518 bp->b_right = NULL; 1519 TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); 1520 } else if (bp->b_lblkno < root->b_lblkno || 1521 (bp->b_lblkno == root->b_lblkno && 1522 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1523 bp->b_left = root->b_left; 1524 bp->b_right = root; 1525 root->b_left = NULL; 1526 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1527 } else { 1528 bp->b_right = root->b_right; 1529 bp->b_left = root; 1530 root->b_right = NULL; 1531 TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, 1532 root, bp, b_vnbufs); 1533 } 1534 vp->v_dirtybufcnt++; 1535 vp->v_dirtyblkroot = bp; 1536 } else { 1537 /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ 1538 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1539 if (root == NULL) { 1540 bp->b_left = NULL; 1541 bp->b_right = NULL; 1542 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1543 } else if (bp->b_lblkno < root->b_lblkno || 1544 (bp->b_lblkno == root->b_lblkno && 1545 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1546 bp->b_left = root->b_left; 1547 bp->b_right = root; 1548 root->b_left = NULL; 1549 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1550 } else { 1551 bp->b_right = root->b_right; 1552 bp->b_left = root; 1553 root->b_right = NULL; 1554 TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, 1555 root, bp, b_vnbufs); 1556 } 1557 vp->v_cleanbufcnt++; 1558 vp->v_cleanblkroot = bp; 1559 } 1560} 1561 1562/* 1563 * Lookup a buffer using the splay tree. Note that we specifically avoid 1564 * shadow buffers used in background bitmap writes. 1565 * 1566 * This code isn't quite efficient as it could be because we are maintaining 1567 * two sorted lists and do not know which list the block resides in. 1568 */ 1569struct buf * 1570gbincore(struct vnode *vp, daddr_t lblkno) 1571{ 1572 struct buf *bp; 1573 1574 GIANT_REQUIRED; 1575 1576 ASSERT_VI_LOCKED(vp, "gbincore"); 1577 bp = vp->v_cleanblkroot = buf_splay(lblkno, 0, vp->v_cleanblkroot); 1578 if (bp && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1579 return(bp); 1580 bp = vp->v_dirtyblkroot = buf_splay(lblkno, 0, vp->v_dirtyblkroot); 1581 if (bp && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1582 return(bp); 1583 return(NULL); 1584} 1585 1586/* 1587 * Associate a buffer with a vnode. 1588 */ 1589void 1590bgetvp(vp, bp) 1591 register struct vnode *vp; 1592 register struct buf *bp; 1593{ 1594 int s; 1595 1596 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1597 1598 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1599 ("bgetvp: bp already attached! %p", bp)); 1600 1601 ASSERT_VI_LOCKED(vp, "bgetvp"); 1602 vholdl(vp); 1603 bp->b_vp = vp; 1604 bp->b_dev = vn_todev(vp); 1605 /* 1606 * Insert onto list for new vnode. 1607 */ 1608 s = splbio(); 1609 buf_vlist_add(bp, vp, BX_VNCLEAN); 1610 splx(s); 1611} 1612 1613/* 1614 * Disassociate a buffer from a vnode. 1615 */ 1616void 1617brelvp(bp) 1618 register struct buf *bp; 1619{ 1620 struct vnode *vp; 1621 int s; 1622 1623 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1624 1625 /* 1626 * Delete from old vnode list, if on one. 1627 */ 1628 vp = bp->b_vp; 1629 s = splbio(); 1630 VI_LOCK(vp); 1631 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1632 buf_vlist_remove(bp); 1633 if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1634 vp->v_iflag &= ~VI_ONWORKLST; 1635 mtx_lock(&sync_mtx); 1636 LIST_REMOVE(vp, v_synclist); 1637 mtx_unlock(&sync_mtx); 1638 } 1639 vdropl(vp); 1640 VI_UNLOCK(vp); 1641 bp->b_vp = (struct vnode *) 0; 1642 if (bp->b_object) 1643 bp->b_object = NULL; 1644 splx(s); 1645} 1646 1647/* 1648 * Add an item to the syncer work queue. 1649 */ 1650static void 1651vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1652{ 1653 int s, slot; 1654 1655 s = splbio(); 1656 ASSERT_VI_LOCKED(vp, "vn_syncer_add_to_worklist"); 1657 1658 mtx_lock(&sync_mtx); 1659 if (vp->v_iflag & VI_ONWORKLST) 1660 LIST_REMOVE(vp, v_synclist); 1661 else 1662 vp->v_iflag |= VI_ONWORKLST; 1663 1664 if (delay > syncer_maxdelay - 2) 1665 delay = syncer_maxdelay - 2; 1666 slot = (syncer_delayno + delay) & syncer_mask; 1667 1668 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1669 mtx_unlock(&sync_mtx); 1670 1671 splx(s); 1672} 1673 1674struct proc *updateproc; 1675static void sched_sync(void); 1676static struct kproc_desc up_kp = { 1677 "syncer", 1678 sched_sync, 1679 &updateproc 1680}; 1681SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1682 1683/* 1684 * System filesystem synchronizer daemon. 1685 */ 1686static void 1687sched_sync(void) 1688{ 1689 struct synclist *slp; 1690 struct vnode *vp; 1691 struct mount *mp; 1692 long starttime; 1693 int s; 1694 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); /* XXXKSE */ 1695 1696 mtx_lock(&Giant); 1697 1698 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, 1699 SHUTDOWN_PRI_LAST); 1700 1701 for (;;) { 1702 kthread_suspend_check(td->td_proc); 1703 1704 starttime = time_second; 1705 1706 /* 1707 * Push files whose dirty time has expired. Be careful 1708 * of interrupt race on slp queue. 1709 */ 1710 s = splbio(); 1711 mtx_lock(&sync_mtx); 1712 slp = &syncer_workitem_pending[syncer_delayno]; 1713 syncer_delayno += 1; 1714 if (syncer_delayno == syncer_maxdelay) 1715 syncer_delayno = 0; 1716 splx(s); 1717 1718 while ((vp = LIST_FIRST(slp)) != NULL) { 1719 mtx_unlock(&sync_mtx); 1720 if (VOP_ISLOCKED(vp, NULL) == 0 && 1721 vn_start_write(vp, &mp, V_NOWAIT) == 0) { 1722 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1723 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1724 VOP_UNLOCK(vp, 0, td); 1725 vn_finished_write(mp); 1726 } 1727 s = splbio(); 1728 mtx_lock(&sync_mtx); 1729 if (LIST_FIRST(slp) == vp) { 1730 mtx_unlock(&sync_mtx); 1731 /* 1732 * Note: VFS vnodes can remain on the 1733 * worklist too with no dirty blocks, but 1734 * since sync_fsync() moves it to a different 1735 * slot we are safe. 1736 */ 1737 VI_LOCK(vp); 1738 if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && 1739 !vn_isdisk(vp, NULL)) { 1740 panic("sched_sync: fsync failed " 1741 "vp %p tag %s", vp, vp->v_tag); 1742 } 1743 /* 1744 * Put us back on the worklist. The worklist 1745 * routine will remove us from our current 1746 * position and then add us back in at a later 1747 * position. 1748 */ 1749 vn_syncer_add_to_worklist(vp, syncdelay); 1750 VI_UNLOCK(vp); 1751 mtx_lock(&sync_mtx); 1752 } 1753 splx(s); 1754 } 1755 mtx_unlock(&sync_mtx); 1756 1757 /* 1758 * Do soft update processing. 1759 */ 1760 if (softdep_process_worklist_hook != NULL) 1761 (*softdep_process_worklist_hook)(NULL); 1762 1763 /* 1764 * The variable rushjob allows the kernel to speed up the 1765 * processing of the filesystem syncer process. A rushjob 1766 * value of N tells the filesystem syncer to process the next 1767 * N seconds worth of work on its queue ASAP. Currently rushjob 1768 * is used by the soft update code to speed up the filesystem 1769 * syncer process when the incore state is getting so far 1770 * ahead of the disk that the kernel memory pool is being 1771 * threatened with exhaustion. 1772 */ 1773 mtx_lock(&sync_mtx); 1774 if (rushjob > 0) { 1775 rushjob -= 1; 1776 mtx_unlock(&sync_mtx); 1777 continue; 1778 } 1779 mtx_unlock(&sync_mtx); 1780 /* 1781 * If it has taken us less than a second to process the 1782 * current work, then wait. Otherwise start right over 1783 * again. We can still lose time if any single round 1784 * takes more than two seconds, but it does not really 1785 * matter as we are just trying to generally pace the 1786 * filesystem activity. 1787 */ 1788 if (time_second == starttime) 1789 tsleep(&lbolt, PPAUSE, "syncer", 0); 1790 } 1791} 1792 1793/* 1794 * Request the syncer daemon to speed up its work. 1795 * We never push it to speed up more than half of its 1796 * normal turn time, otherwise it could take over the cpu. 1797 * XXXKSE only one update? 1798 */ 1799int 1800speedup_syncer() 1801{ 1802 struct thread *td; 1803 int ret = 0; 1804 1805 td = FIRST_THREAD_IN_PROC(updateproc); 1806 mtx_lock_spin(&sched_lock); 1807 if (td->td_wchan == &lbolt) { 1808 unsleep(td); 1809 TD_CLR_SLEEPING(td); 1810 setrunnable(td); 1811 } 1812 mtx_unlock_spin(&sched_lock); 1813 mtx_lock(&sync_mtx); 1814 if (rushjob < syncdelay / 2) { 1815 rushjob += 1; 1816 stat_rush_requests += 1; 1817 ret = 1; 1818 } 1819 mtx_unlock(&sync_mtx); 1820 return (ret); 1821} 1822 1823/* 1824 * Associate a p-buffer with a vnode. 1825 * 1826 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1827 * with the buffer. i.e. the bp has not been linked into the vnode or 1828 * ref-counted. 1829 */ 1830void 1831pbgetvp(vp, bp) 1832 register struct vnode *vp; 1833 register struct buf *bp; 1834{ 1835 1836 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1837 1838 bp->b_vp = vp; 1839 bp->b_flags |= B_PAGING; 1840 bp->b_dev = vn_todev(vp); 1841} 1842 1843/* 1844 * Disassociate a p-buffer from a vnode. 1845 */ 1846void 1847pbrelvp(bp) 1848 register struct buf *bp; 1849{ 1850 1851 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1852 1853 /* XXX REMOVE ME */ 1854 VI_LOCK(bp->b_vp); 1855 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1856 panic( 1857 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1858 bp, 1859 (int)bp->b_flags 1860 ); 1861 } 1862 VI_UNLOCK(bp->b_vp); 1863 bp->b_vp = (struct vnode *) 0; 1864 bp->b_flags &= ~B_PAGING; 1865} 1866 1867/* 1868 * Reassign a buffer from one vnode to another. 1869 * Used to assign file specific control information 1870 * (indirect blocks) to the vnode to which they belong. 1871 */ 1872void 1873reassignbuf(bp, newvp) 1874 register struct buf *bp; 1875 register struct vnode *newvp; 1876{ 1877 int delay; 1878 int s; 1879 1880 if (newvp == NULL) { 1881 printf("reassignbuf: NULL"); 1882 return; 1883 } 1884 ++reassignbufcalls; 1885 1886 /* 1887 * B_PAGING flagged buffers cannot be reassigned because their vp 1888 * is not fully linked in. 1889 */ 1890 if (bp->b_flags & B_PAGING) 1891 panic("cannot reassign paging buffer"); 1892 1893 s = splbio(); 1894 /* 1895 * Delete from old vnode list, if on one. 1896 */ 1897 VI_LOCK(bp->b_vp); 1898 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1899 buf_vlist_remove(bp); 1900 if (bp->b_vp != newvp) { 1901 vdropl(bp->b_vp); 1902 bp->b_vp = NULL; /* for clarification */ 1903 } 1904 } 1905 VI_UNLOCK(bp->b_vp); 1906 /* 1907 * If dirty, put on list of dirty buffers; otherwise insert onto list 1908 * of clean buffers. 1909 */ 1910 VI_LOCK(newvp); 1911 if (bp->b_flags & B_DELWRI) { 1912 if ((newvp->v_iflag & VI_ONWORKLST) == 0) { 1913 switch (newvp->v_type) { 1914 case VDIR: 1915 delay = dirdelay; 1916 break; 1917 case VCHR: 1918 if (newvp->v_rdev->si_mountpoint != NULL) { 1919 delay = metadelay; 1920 break; 1921 } 1922 /* FALLTHROUGH */ 1923 default: 1924 delay = filedelay; 1925 } 1926 vn_syncer_add_to_worklist(newvp, delay); 1927 } 1928 buf_vlist_add(bp, newvp, BX_VNDIRTY); 1929 } else { 1930 buf_vlist_add(bp, newvp, BX_VNCLEAN); 1931 1932 if ((newvp->v_iflag & VI_ONWORKLST) && 1933 TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { 1934 mtx_lock(&sync_mtx); 1935 LIST_REMOVE(newvp, v_synclist); 1936 mtx_unlock(&sync_mtx); 1937 newvp->v_iflag &= ~VI_ONWORKLST; 1938 } 1939 } 1940 if (bp->b_vp != newvp) { 1941 bp->b_vp = newvp; 1942 vholdl(bp->b_vp); 1943 } 1944 VI_UNLOCK(newvp); 1945 splx(s); 1946} 1947 1948/* 1949 * Create a vnode for a device. 1950 * Used for mounting the root filesystem. 1951 */ 1952int 1953bdevvp(dev, vpp) 1954 dev_t dev; 1955 struct vnode **vpp; 1956{ 1957 register struct vnode *vp; 1958 struct vnode *nvp; 1959 int error; 1960 1961 if (dev == NODEV) { 1962 *vpp = NULLVP; 1963 return (ENXIO); 1964 } 1965 if (vfinddev(dev, VCHR, vpp)) 1966 return (0); 1967 error = getnewvnode("none", (struct mount *)0, spec_vnodeop_p, &nvp); 1968 if (error) { 1969 *vpp = NULLVP; 1970 return (error); 1971 } 1972 vp = nvp; 1973 vp->v_type = VCHR; 1974 addalias(vp, dev); 1975 *vpp = vp; 1976 return (0); 1977} 1978 1979static void 1980v_incr_usecount(struct vnode *vp, int delta) 1981{ 1982 vp->v_usecount += delta; 1983 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1984 mtx_lock(&spechash_mtx); 1985 vp->v_rdev->si_usecount += delta; 1986 mtx_unlock(&spechash_mtx); 1987 } 1988} 1989 1990/* 1991 * Add vnode to the alias list hung off the dev_t. 1992 * 1993 * The reason for this gunk is that multiple vnodes can reference 1994 * the same physical device, so checking vp->v_usecount to see 1995 * how many users there are is inadequate; the v_usecount for 1996 * the vnodes need to be accumulated. vcount() does that. 1997 */ 1998struct vnode * 1999addaliasu(nvp, nvp_rdev) 2000 struct vnode *nvp; 2001 udev_t nvp_rdev; 2002{ 2003 struct vnode *ovp; 2004 vop_t **ops; 2005 dev_t dev; 2006 2007 if (nvp->v_type == VBLK) 2008 return (nvp); 2009 if (nvp->v_type != VCHR) 2010 panic("addaliasu on non-special vnode"); 2011 dev = udev2dev(nvp_rdev, 0); 2012 /* 2013 * Check to see if we have a bdevvp vnode with no associated 2014 * filesystem. If so, we want to associate the filesystem of 2015 * the new newly instigated vnode with the bdevvp vnode and 2016 * discard the newly created vnode rather than leaving the 2017 * bdevvp vnode lying around with no associated filesystem. 2018 */ 2019 if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { 2020 addalias(nvp, dev); 2021 return (nvp); 2022 } 2023 /* 2024 * Discard unneeded vnode, but save its node specific data. 2025 * Note that if there is a lock, it is carried over in the 2026 * node specific data to the replacement vnode. 2027 */ 2028 vref(ovp); 2029 ovp->v_data = nvp->v_data; 2030 ovp->v_tag = nvp->v_tag; 2031 nvp->v_data = NULL; 2032 lockdestroy(ovp->v_vnlock); 2033 lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, 2034 nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); 2035 ops = ovp->v_op; 2036 ovp->v_op = nvp->v_op; 2037 if (VOP_ISLOCKED(nvp, curthread)) { 2038 VOP_UNLOCK(nvp, 0, curthread); 2039 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 2040 } 2041 nvp->v_op = ops; 2042 insmntque(ovp, nvp->v_mount); 2043 vrele(nvp); 2044 vgone(nvp); 2045 return (ovp); 2046} 2047 2048/* This is a local helper function that do the same as addaliasu, but for a 2049 * dev_t instead of an udev_t. */ 2050static void 2051addalias(nvp, dev) 2052 struct vnode *nvp; 2053 dev_t dev; 2054{ 2055 2056 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 2057 nvp->v_rdev = dev; 2058 VI_LOCK(nvp); 2059 mtx_lock(&spechash_mtx); 2060 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 2061 dev->si_usecount += nvp->v_usecount; 2062 mtx_unlock(&spechash_mtx); 2063 VI_UNLOCK(nvp); 2064} 2065 2066/* 2067 * Grab a particular vnode from the free list, increment its 2068 * reference count and lock it. The vnode lock bit is set if the 2069 * vnode is being eliminated in vgone. The process is awakened 2070 * when the transition is completed, and an error returned to 2071 * indicate that the vnode is no longer usable (possibly having 2072 * been changed to a new filesystem type). 2073 */ 2074int 2075vget(vp, flags, td) 2076 register struct vnode *vp; 2077 int flags; 2078 struct thread *td; 2079{ 2080 int error; 2081 2082 /* 2083 * If the vnode is in the process of being cleaned out for 2084 * another use, we wait for the cleaning to finish and then 2085 * return failure. Cleaning is determined by checking that 2086 * the VI_XLOCK flag is set. 2087 */ 2088 if ((flags & LK_INTERLOCK) == 0) 2089 VI_LOCK(vp); 2090 if (vp->v_iflag & VI_XLOCK && vp->v_vxproc != curthread) { 2091 vp->v_iflag |= VI_XWANT; 2092 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); 2093 return (ENOENT); 2094 } 2095 2096 v_incr_usecount(vp, 1); 2097 2098 if (VSHOULDBUSY(vp)) 2099 vbusy(vp); 2100 if (flags & LK_TYPE_MASK) { 2101 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 2102 /* 2103 * must expand vrele here because we do not want 2104 * to call VOP_INACTIVE if the reference count 2105 * drops back to zero since it was never really 2106 * active. We must remove it from the free list 2107 * before sleeping so that multiple processes do 2108 * not try to recycle it. 2109 */ 2110 VI_LOCK(vp); 2111 v_incr_usecount(vp, -1); 2112 if (VSHOULDFREE(vp)) 2113 vfree(vp); 2114 else 2115 vlruvp(vp); 2116 VI_UNLOCK(vp); 2117 } 2118 return (error); 2119 } 2120 VI_UNLOCK(vp); 2121 return (0); 2122} 2123 2124/* 2125 * Increase the reference count of a vnode. 2126 */ 2127void 2128vref(struct vnode *vp) 2129{ 2130 VI_LOCK(vp); 2131 v_incr_usecount(vp, 1); 2132 VI_UNLOCK(vp); 2133} 2134 2135/* 2136 * Return reference count of a vnode. 2137 * 2138 * The results of this call are only guaranteed when some mechanism other 2139 * than the VI lock is used to stop other processes from gaining references 2140 * to the vnode. This may be the case if the caller holds the only reference. 2141 * This is also useful when stale data is acceptable as race conditions may 2142 * be accounted for by some other means. 2143 */ 2144int 2145vrefcnt(struct vnode *vp) 2146{ 2147 int usecnt; 2148 2149 VI_LOCK(vp); 2150 usecnt = vp->v_usecount; 2151 VI_UNLOCK(vp); 2152 2153 return (usecnt); 2154} 2155 2156 2157/* 2158 * Vnode put/release. 2159 * If count drops to zero, call inactive routine and return to freelist. 2160 */ 2161void 2162vrele(vp) 2163 struct vnode *vp; 2164{ 2165 struct thread *td = curthread; /* XXX */ 2166 2167 KASSERT(vp != NULL, ("vrele: null vp")); 2168 2169 VI_LOCK(vp); 2170 2171 /* Skip this v_writecount check if we're going to panic below. */ 2172 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2173 ("vrele: missed vn_close")); 2174 2175 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2176 vp->v_usecount == 1)) { 2177 v_incr_usecount(vp, -1); 2178 VI_UNLOCK(vp); 2179 2180 return; 2181 } 2182 2183 if (vp->v_usecount == 1) { 2184 v_incr_usecount(vp, -1); 2185 /* 2186 * We must call VOP_INACTIVE with the node locked. Mark 2187 * as VI_DOINGINACT to avoid recursion. 2188 */ 2189 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 2190 VI_LOCK(vp); 2191 vp->v_iflag |= VI_DOINGINACT; 2192 VI_UNLOCK(vp); 2193 VOP_INACTIVE(vp, td); 2194 VI_LOCK(vp); 2195 KASSERT(vp->v_iflag & VI_DOINGINACT, 2196 ("vrele: lost VI_DOINGINACT")); 2197 vp->v_iflag &= ~VI_DOINGINACT; 2198 VI_UNLOCK(vp); 2199 } 2200 VI_LOCK(vp); 2201 if (VSHOULDFREE(vp)) 2202 vfree(vp); 2203 else 2204 vlruvp(vp); 2205 VI_UNLOCK(vp); 2206 2207 } else { 2208#ifdef DIAGNOSTIC 2209 vprint("vrele: negative ref count", vp); 2210#endif 2211 VI_UNLOCK(vp); 2212 panic("vrele: negative ref cnt"); 2213 } 2214} 2215 2216/* 2217 * Release an already locked vnode. This give the same effects as 2218 * unlock+vrele(), but takes less time and avoids releasing and 2219 * re-aquiring the lock (as vrele() aquires the lock internally.) 2220 */ 2221void 2222vput(vp) 2223 struct vnode *vp; 2224{ 2225 struct thread *td = curthread; /* XXX */ 2226 2227 GIANT_REQUIRED; 2228 2229 KASSERT(vp != NULL, ("vput: null vp")); 2230 VI_LOCK(vp); 2231 /* Skip this v_writecount check if we're going to panic below. */ 2232 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2233 ("vput: missed vn_close")); 2234 2235 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2236 vp->v_usecount == 1)) { 2237 v_incr_usecount(vp, -1); 2238 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2239 return; 2240 } 2241 2242 if (vp->v_usecount == 1) { 2243 v_incr_usecount(vp, -1); 2244 /* 2245 * We must call VOP_INACTIVE with the node locked, so 2246 * we just need to release the vnode mutex. Mark as 2247 * as VI_DOINGINACT to avoid recursion. 2248 */ 2249 vp->v_iflag |= VI_DOINGINACT; 2250 VI_UNLOCK(vp); 2251 VOP_INACTIVE(vp, td); 2252 VI_LOCK(vp); 2253 KASSERT(vp->v_iflag & VI_DOINGINACT, 2254 ("vput: lost VI_DOINGINACT")); 2255 vp->v_iflag &= ~VI_DOINGINACT; 2256 if (VSHOULDFREE(vp)) 2257 vfree(vp); 2258 else 2259 vlruvp(vp); 2260 VI_UNLOCK(vp); 2261 2262 } else { 2263#ifdef DIAGNOSTIC 2264 vprint("vput: negative ref count", vp); 2265#endif 2266 panic("vput: negative ref cnt"); 2267 } 2268} 2269 2270/* 2271 * Somebody doesn't want the vnode recycled. 2272 */ 2273void 2274vhold(struct vnode *vp) 2275{ 2276 VI_LOCK(vp); 2277 vholdl(vp); 2278 VI_UNLOCK(vp); 2279} 2280 2281void 2282vholdl(vp) 2283 register struct vnode *vp; 2284{ 2285 int s; 2286 2287 s = splbio(); 2288 vp->v_holdcnt++; 2289 if (VSHOULDBUSY(vp)) 2290 vbusy(vp); 2291 splx(s); 2292} 2293 2294/* 2295 * Note that there is one less who cares about this vnode. vdrop() is the 2296 * opposite of vhold(). 2297 */ 2298void 2299vdrop(struct vnode *vp) 2300{ 2301 VI_LOCK(vp); 2302 vdropl(vp); 2303 VI_UNLOCK(vp); 2304} 2305 2306void 2307vdropl(vp) 2308 register struct vnode *vp; 2309{ 2310 int s; 2311 2312 s = splbio(); 2313 if (vp->v_holdcnt <= 0) 2314 panic("vdrop: holdcnt"); 2315 vp->v_holdcnt--; 2316 if (VSHOULDFREE(vp)) 2317 vfree(vp); 2318 else 2319 vlruvp(vp); 2320 splx(s); 2321} 2322 2323/* 2324 * Remove any vnodes in the vnode table belonging to mount point mp. 2325 * 2326 * If FORCECLOSE is not specified, there should not be any active ones, 2327 * return error if any are found (nb: this is a user error, not a 2328 * system error). If FORCECLOSE is specified, detach any active vnodes 2329 * that are found. 2330 * 2331 * If WRITECLOSE is set, only flush out regular file vnodes open for 2332 * writing. 2333 * 2334 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2335 * 2336 * `rootrefs' specifies the base reference count for the root vnode 2337 * of this filesystem. The root vnode is considered busy if its 2338 * v_usecount exceeds this value. On a successful return, vflush() 2339 * will call vrele() on the root vnode exactly rootrefs times. 2340 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2341 * be zero. 2342 */ 2343#ifdef DIAGNOSTIC 2344static int busyprt = 0; /* print out busy vnodes */ 2345SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2346#endif 2347 2348int 2349vflush(mp, rootrefs, flags) 2350 struct mount *mp; 2351 int rootrefs; 2352 int flags; 2353{ 2354 struct thread *td = curthread; /* XXX */ 2355 struct vnode *vp, *nvp, *rootvp = NULL; 2356 struct vattr vattr; 2357 int busy = 0, error; 2358 2359 if (rootrefs > 0) { 2360 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2361 ("vflush: bad args")); 2362 /* 2363 * Get the filesystem root vnode. We can vput() it 2364 * immediately, since with rootrefs > 0, it won't go away. 2365 */ 2366 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 2367 return (error); 2368 vput(rootvp); 2369 2370 } 2371 mtx_lock(&mntvnode_mtx); 2372loop: 2373 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 2374 /* 2375 * Make sure this vnode wasn't reclaimed in getnewvnode(). 2376 * Start over if it has (it won't be on the list anymore). 2377 */ 2378 if (vp->v_mount != mp) 2379 goto loop; 2380 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2381 2382 VI_LOCK(vp); 2383 mtx_unlock(&mntvnode_mtx); 2384 vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY, td); 2385 /* 2386 * Skip over a vnodes marked VV_SYSTEM. 2387 */ 2388 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2389 VOP_UNLOCK(vp, 0, td); 2390 mtx_lock(&mntvnode_mtx); 2391 continue; 2392 } 2393 /* 2394 * If WRITECLOSE is set, flush out unlinked but still open 2395 * files (even if open only for reading) and regular file 2396 * vnodes open for writing. 2397 */ 2398 if (flags & WRITECLOSE) { 2399 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2400 VI_LOCK(vp); 2401 2402 if ((vp->v_type == VNON || 2403 (error == 0 && vattr.va_nlink > 0)) && 2404 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2405 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2406 mtx_lock(&mntvnode_mtx); 2407 continue; 2408 } 2409 } else 2410 VI_LOCK(vp); 2411 2412 VOP_UNLOCK(vp, 0, td); 2413 2414 /* 2415 * With v_usecount == 0, all we need to do is clear out the 2416 * vnode data structures and we are done. 2417 */ 2418 if (vp->v_usecount == 0) { 2419 vgonel(vp, td); 2420 mtx_lock(&mntvnode_mtx); 2421 continue; 2422 } 2423 2424 /* 2425 * If FORCECLOSE is set, forcibly close the vnode. For block 2426 * or character devices, revert to an anonymous device. For 2427 * all other files, just kill them. 2428 */ 2429 if (flags & FORCECLOSE) { 2430 if (vp->v_type != VCHR) { 2431 vgonel(vp, td); 2432 } else { 2433 vclean(vp, 0, td); 2434 VI_UNLOCK(vp); 2435 vp->v_op = spec_vnodeop_p; 2436 insmntque(vp, (struct mount *) 0); 2437 } 2438 mtx_lock(&mntvnode_mtx); 2439 continue; 2440 } 2441#ifdef DIAGNOSTIC 2442 if (busyprt) 2443 vprint("vflush: busy vnode", vp); 2444#endif 2445 VI_UNLOCK(vp); 2446 mtx_lock(&mntvnode_mtx); 2447 busy++; 2448 } 2449 mtx_unlock(&mntvnode_mtx); 2450 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2451 /* 2452 * If just the root vnode is busy, and if its refcount 2453 * is equal to `rootrefs', then go ahead and kill it. 2454 */ 2455 VI_LOCK(rootvp); 2456 KASSERT(busy > 0, ("vflush: not busy")); 2457 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 2458 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2459 vgonel(rootvp, td); 2460 busy = 0; 2461 } else 2462 VI_UNLOCK(rootvp); 2463 } 2464 if (busy) 2465 return (EBUSY); 2466 for (; rootrefs > 0; rootrefs--) 2467 vrele(rootvp); 2468 return (0); 2469} 2470 2471/* 2472 * This moves a now (likely recyclable) vnode to the end of the 2473 * mountlist. XXX However, it is temporarily disabled until we 2474 * can clean up ffs_sync() and friends, which have loop restart 2475 * conditions which this code causes to operate O(N^2). 2476 */ 2477static void 2478vlruvp(struct vnode *vp) 2479{ 2480#if 0 2481 struct mount *mp; 2482 2483 if ((mp = vp->v_mount) != NULL) { 2484 mtx_lock(&mntvnode_mtx); 2485 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2486 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2487 mtx_unlock(&mntvnode_mtx); 2488 } 2489#endif 2490} 2491 2492/* 2493 * Disassociate the underlying filesystem from a vnode. 2494 */ 2495static void 2496vclean(vp, flags, td) 2497 struct vnode *vp; 2498 int flags; 2499 struct thread *td; 2500{ 2501 int active; 2502 2503 ASSERT_VI_LOCKED(vp, "vclean"); 2504 /* 2505 * Check to see if the vnode is in use. If so we have to reference it 2506 * before we clean it out so that its count cannot fall to zero and 2507 * generate a race against ourselves to recycle it. 2508 */ 2509 if ((active = vp->v_usecount)) 2510 v_incr_usecount(vp, 1); 2511 2512 /* 2513 * Prevent the vnode from being recycled or brought into use while we 2514 * clean it out. 2515 */ 2516 if (vp->v_iflag & VI_XLOCK) 2517 panic("vclean: deadlock"); 2518 vp->v_iflag |= VI_XLOCK; 2519 vp->v_vxproc = curthread; 2520 /* 2521 * Even if the count is zero, the VOP_INACTIVE routine may still 2522 * have the object locked while it cleans it out. The VOP_LOCK 2523 * ensures that the VOP_INACTIVE routine is done with its work. 2524 * For active vnodes, it ensures that no other activity can 2525 * occur while the underlying object is being cleaned out. 2526 */ 2527 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2528 2529 /* 2530 * Clean out any buffers associated with the vnode. 2531 * If the flush fails, just toss the buffers. 2532 */ 2533 if (flags & DOCLOSE) { 2534 struct buf *bp; 2535 VI_LOCK(vp); 2536 bp = TAILQ_FIRST(&vp->v_dirtyblkhd); 2537 VI_UNLOCK(vp); 2538 if (bp != NULL) 2539 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2540 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2541 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2542 } 2543 2544 VOP_DESTROYVOBJECT(vp); 2545 2546 /* 2547 * Any other processes trying to obtain this lock must first 2548 * wait for VXLOCK to clear, then call the new lock operation. 2549 */ 2550 VOP_UNLOCK(vp, 0, td); 2551 2552 /* 2553 * If purging an active vnode, it must be closed and 2554 * deactivated before being reclaimed. Note that the 2555 * VOP_INACTIVE will unlock the vnode. 2556 */ 2557 if (active) { 2558 if (flags & DOCLOSE) 2559 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2560 VI_LOCK(vp); 2561 if ((vp->v_iflag & VI_DOINGINACT) == 0) { 2562 vp->v_iflag |= VI_DOINGINACT; 2563 VI_UNLOCK(vp); 2564 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2565 panic("vclean: cannot relock."); 2566 VOP_INACTIVE(vp, td); 2567 VI_LOCK(vp); 2568 KASSERT(vp->v_iflag & VI_DOINGINACT, 2569 ("vclean: lost VI_DOINGINACT")); 2570 vp->v_iflag &= ~VI_DOINGINACT; 2571 } 2572 VI_UNLOCK(vp); 2573 } 2574 2575 /* 2576 * Reclaim the vnode. 2577 */ 2578 if (VOP_RECLAIM(vp, td)) 2579 panic("vclean: cannot reclaim"); 2580 2581 if (active) { 2582 /* 2583 * Inline copy of vrele() since VOP_INACTIVE 2584 * has already been called. 2585 */ 2586 VI_LOCK(vp); 2587 v_incr_usecount(vp, -1); 2588 if (vp->v_usecount <= 0) { 2589#ifdef DIAGNOSTIC 2590 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2591 vprint("vclean: bad ref count", vp); 2592 panic("vclean: ref cnt"); 2593 } 2594#endif 2595 vfree(vp); 2596 } 2597 VI_UNLOCK(vp); 2598 } 2599 2600 cache_purge(vp); 2601 VI_LOCK(vp); 2602 if (VSHOULDFREE(vp)) 2603 vfree(vp); 2604 2605 /* 2606 * Done with purge, reset to the standard lock and 2607 * notify sleepers of the grim news. 2608 */ 2609 vp->v_vnlock = &vp->v_lock; 2610 vp->v_op = dead_vnodeop_p; 2611 if (vp->v_pollinfo != NULL) 2612 vn_pollgone(vp); 2613 vp->v_tag = "none"; 2614 vp->v_iflag &= ~VI_XLOCK; 2615 vp->v_vxproc = NULL; 2616 if (vp->v_iflag & VI_XWANT) { 2617 vp->v_iflag &= ~VI_XWANT; 2618 wakeup(vp); 2619 } 2620} 2621 2622/* 2623 * Eliminate all activity associated with the requested vnode 2624 * and with all vnodes aliased to the requested vnode. 2625 */ 2626int 2627vop_revoke(ap) 2628 struct vop_revoke_args /* { 2629 struct vnode *a_vp; 2630 int a_flags; 2631 } */ *ap; 2632{ 2633 struct vnode *vp, *vq; 2634 dev_t dev; 2635 2636 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2637 vp = ap->a_vp; 2638 KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); 2639 2640 VI_LOCK(vp); 2641 /* 2642 * If a vgone (or vclean) is already in progress, 2643 * wait until it is done and return. 2644 */ 2645 if (vp->v_iflag & VI_XLOCK) { 2646 vp->v_iflag |= VI_XWANT; 2647 msleep(vp, VI_MTX(vp), PINOD | PDROP, 2648 "vop_revokeall", 0); 2649 return (0); 2650 } 2651 VI_UNLOCK(vp); 2652 dev = vp->v_rdev; 2653 for (;;) { 2654 mtx_lock(&spechash_mtx); 2655 vq = SLIST_FIRST(&dev->si_hlist); 2656 mtx_unlock(&spechash_mtx); 2657 if (!vq) 2658 break; 2659 vgone(vq); 2660 } 2661 return (0); 2662} 2663 2664/* 2665 * Recycle an unused vnode to the front of the free list. 2666 * Release the passed interlock if the vnode will be recycled. 2667 */ 2668int 2669vrecycle(vp, inter_lkp, td) 2670 struct vnode *vp; 2671 struct mtx *inter_lkp; 2672 struct thread *td; 2673{ 2674 2675 VI_LOCK(vp); 2676 if (vp->v_usecount == 0) { 2677 if (inter_lkp) { 2678 mtx_unlock(inter_lkp); 2679 } 2680 vgonel(vp, td); 2681 return (1); 2682 } 2683 VI_UNLOCK(vp); 2684 return (0); 2685} 2686 2687/* 2688 * Eliminate all activity associated with a vnode 2689 * in preparation for reuse. 2690 */ 2691void 2692vgone(vp) 2693 register struct vnode *vp; 2694{ 2695 struct thread *td = curthread; /* XXX */ 2696 2697 VI_LOCK(vp); 2698 vgonel(vp, td); 2699} 2700 2701/* 2702 * vgone, with the vp interlock held. 2703 */ 2704void 2705vgonel(vp, td) 2706 struct vnode *vp; 2707 struct thread *td; 2708{ 2709 int s; 2710 2711 /* 2712 * If a vgone (or vclean) is already in progress, 2713 * wait until it is done and return. 2714 */ 2715 ASSERT_VI_LOCKED(vp, "vgonel"); 2716 if (vp->v_iflag & VI_XLOCK) { 2717 vp->v_iflag |= VI_XWANT; 2718 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); 2719 return; 2720 } 2721 2722 /* 2723 * Clean out the filesystem specific data. 2724 */ 2725 vclean(vp, DOCLOSE, td); 2726 VI_UNLOCK(vp); 2727 2728 /* 2729 * Delete from old mount point vnode list, if on one. 2730 */ 2731 if (vp->v_mount != NULL) 2732 insmntque(vp, (struct mount *)0); 2733 /* 2734 * If special device, remove it from special device alias list 2735 * if it is on one. 2736 */ 2737 if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { 2738 VI_LOCK(vp); 2739 mtx_lock(&spechash_mtx); 2740 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2741 vp->v_rdev->si_usecount -= vp->v_usecount; 2742 mtx_unlock(&spechash_mtx); 2743 VI_UNLOCK(vp); 2744 vp->v_rdev = NULL; 2745 } 2746 2747 /* 2748 * If it is on the freelist and not already at the head, 2749 * move it to the head of the list. The test of the 2750 * VDOOMED flag and the reference count of zero is because 2751 * it will be removed from the free list by getnewvnode, 2752 * but will not have its reference count incremented until 2753 * after calling vgone. If the reference count were 2754 * incremented first, vgone would (incorrectly) try to 2755 * close the previous instance of the underlying object. 2756 */ 2757 VI_LOCK(vp); 2758 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2759 s = splbio(); 2760 mtx_lock(&vnode_free_list_mtx); 2761 if (vp->v_iflag & VI_FREE) { 2762 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2763 } else { 2764 vp->v_iflag |= VI_FREE; 2765 freevnodes++; 2766 } 2767 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2768 mtx_unlock(&vnode_free_list_mtx); 2769 splx(s); 2770 } 2771 2772 vp->v_type = VBAD; 2773 VI_UNLOCK(vp); 2774} 2775 2776/* 2777 * Lookup a vnode by device number. 2778 */ 2779int 2780vfinddev(dev, type, vpp) 2781 dev_t dev; 2782 enum vtype type; 2783 struct vnode **vpp; 2784{ 2785 struct vnode *vp; 2786 2787 mtx_lock(&spechash_mtx); 2788 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2789 if (type == vp->v_type) { 2790 *vpp = vp; 2791 mtx_unlock(&spechash_mtx); 2792 return (1); 2793 } 2794 } 2795 mtx_unlock(&spechash_mtx); 2796 return (0); 2797} 2798 2799/* 2800 * Calculate the total number of references to a special device. 2801 */ 2802int 2803vcount(vp) 2804 struct vnode *vp; 2805{ 2806 int count; 2807 2808 mtx_lock(&spechash_mtx); 2809 count = vp->v_rdev->si_usecount; 2810 mtx_unlock(&spechash_mtx); 2811 return (count); 2812} 2813 2814/* 2815 * Same as above, but using the dev_t as argument 2816 */ 2817int 2818count_dev(dev) 2819 dev_t dev; 2820{ 2821 struct vnode *vp; 2822 2823 vp = SLIST_FIRST(&dev->si_hlist); 2824 if (vp == NULL) 2825 return (0); 2826 return(vcount(vp)); 2827} 2828 2829/* 2830 * Print out a description of a vnode. 2831 */ 2832static char *typename[] = 2833{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2834 2835void 2836vprint(label, vp) 2837 char *label; 2838 struct vnode *vp; 2839{ 2840 char buf[96]; 2841 2842 if (label != NULL) 2843 printf("%s: %p: ", label, (void *)vp); 2844 else 2845 printf("%p: ", (void *)vp); 2846 printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", 2847 vp->v_tag, typename[vp->v_type], vp->v_usecount, 2848 vp->v_writecount, vp->v_holdcnt); 2849 buf[0] = '\0'; 2850 if (vp->v_vflag & VV_ROOT) 2851 strcat(buf, "|VV_ROOT"); 2852 if (vp->v_vflag & VV_TEXT) 2853 strcat(buf, "|VV_TEXT"); 2854 if (vp->v_vflag & VV_SYSTEM) 2855 strcat(buf, "|VV_SYSTEM"); 2856 if (vp->v_iflag & VI_XLOCK) 2857 strcat(buf, "|VI_XLOCK"); 2858 if (vp->v_iflag & VI_XWANT) 2859 strcat(buf, "|VI_XWANT"); 2860 if (vp->v_iflag & VI_BWAIT) 2861 strcat(buf, "|VI_BWAIT"); 2862 if (vp->v_iflag & VI_DOOMED) 2863 strcat(buf, "|VI_DOOMED"); 2864 if (vp->v_iflag & VI_FREE) 2865 strcat(buf, "|VI_FREE"); 2866 if (vp->v_vflag & VV_OBJBUF) 2867 strcat(buf, "|VV_OBJBUF"); 2868 if (buf[0] != '\0') 2869 printf(" flags (%s),", &buf[1]); 2870 lockmgr_printinfo(vp->v_vnlock); 2871 printf("\n"); 2872 if (vp->v_data != NULL) 2873 VOP_PRINT(vp); 2874} 2875 2876#ifdef DDB 2877#include <ddb/ddb.h> 2878/* 2879 * List all of the locked vnodes in the system. 2880 * Called when debugging the kernel. 2881 */ 2882DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2883{ 2884 struct mount *mp, *nmp; 2885 struct vnode *vp; 2886 2887 /* 2888 * Note: because this is DDB, we can't obey the locking semantics 2889 * for these structures, which means we could catch an inconsistent 2890 * state and dereference a nasty pointer. Not much to be done 2891 * about that. 2892 */ 2893 printf("Locked vnodes\n"); 2894 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2895 nmp = TAILQ_NEXT(mp, mnt_list); 2896 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2897 if (VOP_ISLOCKED(vp, NULL)) 2898 vprint(NULL, vp); 2899 } 2900 nmp = TAILQ_NEXT(mp, mnt_list); 2901 } 2902} 2903#endif 2904 2905/* 2906 * Fill in a struct xvfsconf based on a struct vfsconf. 2907 */ 2908static void 2909vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2910{ 2911 2912 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2913 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2914 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2915 xvfsp->vfc_flags = vfsp->vfc_flags; 2916 /* 2917 * These are unused in userland, we keep them 2918 * to not break binary compatibility. 2919 */ 2920 xvfsp->vfc_vfsops = NULL; 2921 xvfsp->vfc_next = NULL; 2922} 2923 2924static int 2925sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2926{ 2927 struct vfsconf *vfsp; 2928 struct xvfsconf *xvfsp; 2929 int cnt, error, i; 2930 2931 cnt = 0; 2932 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 2933 cnt++; 2934 xvfsp = malloc(sizeof(struct xvfsconf) * cnt, M_TEMP, M_WAITOK); 2935 /* 2936 * Handle the race that we will have here when struct vfsconf 2937 * will be locked down by using both cnt and checking vfc_next 2938 * against NULL to determine the end of the loop. The race will 2939 * happen because we will have to unlock before calling malloc(). 2940 * We are protected by Giant for now. 2941 */ 2942 i = 0; 2943 for (vfsp = vfsconf; vfsp != NULL && i < cnt; vfsp = vfsp->vfc_next) { 2944 vfsconf2x(vfsp, xvfsp + i); 2945 i++; 2946 } 2947 error = SYSCTL_OUT(req, xvfsp, sizeof(struct xvfsconf) * i); 2948 free(xvfsp, M_TEMP); 2949 return (error); 2950} 2951 2952SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2953 "S,xvfsconf", "List of all configured filesystems"); 2954 2955/* 2956 * Top level filesystem related information gathering. 2957 */ 2958static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2959 2960static int 2961vfs_sysctl(SYSCTL_HANDLER_ARGS) 2962{ 2963 int *name = (int *)arg1 - 1; /* XXX */ 2964 u_int namelen = arg2 + 1; /* XXX */ 2965 struct vfsconf *vfsp; 2966 struct xvfsconf xvfsp; 2967 2968 printf("WARNING: userland calling deprecated sysctl, " 2969 "please rebuild world\n"); 2970 2971#if 1 || defined(COMPAT_PRELITE2) 2972 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2973 if (namelen == 1) 2974 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2975#endif 2976 2977 switch (name[1]) { 2978 case VFS_MAXTYPENUM: 2979 if (namelen != 2) 2980 return (ENOTDIR); 2981 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2982 case VFS_CONF: 2983 if (namelen != 3) 2984 return (ENOTDIR); /* overloaded */ 2985 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2986 if (vfsp->vfc_typenum == name[2]) 2987 break; 2988 if (vfsp == NULL) 2989 return (EOPNOTSUPP); 2990 vfsconf2x(vfsp, &xvfsp); 2991 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2992 } 2993 return (EOPNOTSUPP); 2994} 2995 2996SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 2997 "Generic filesystem"); 2998 2999#if 1 || defined(COMPAT_PRELITE2) 3000 3001static int 3002sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3003{ 3004 int error; 3005 struct vfsconf *vfsp; 3006 struct ovfsconf ovfs; 3007 3008 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 3009 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3010 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3011 ovfs.vfc_index = vfsp->vfc_typenum; 3012 ovfs.vfc_refcount = vfsp->vfc_refcount; 3013 ovfs.vfc_flags = vfsp->vfc_flags; 3014 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3015 if (error) 3016 return error; 3017 } 3018 return 0; 3019} 3020 3021#endif /* 1 || COMPAT_PRELITE2 */ 3022 3023#define KINFO_VNODESLOP 10 3024#ifdef notyet 3025/* 3026 * Dump vnode list (via sysctl). 3027 */ 3028/* ARGSUSED */ 3029static int 3030sysctl_vnode(SYSCTL_HANDLER_ARGS) 3031{ 3032 struct xvnode *xvn; 3033 struct thread *td = req->td; 3034 struct mount *mp; 3035 struct vnode *vp; 3036 int error, len, n; 3037 3038 /* 3039 * Stale numvnodes access is not fatal here. 3040 */ 3041 req->lock = 0; 3042 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3043 if (!req->oldptr) 3044 /* Make an estimate */ 3045 return (SYSCTL_OUT(req, 0, len)); 3046 3047 sysctl_wire_old_buffer(req, 0); 3048 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3049 n = 0; 3050 mtx_lock(&mountlist_mtx); 3051 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3052 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 3053 continue; 3054 mtx_lock(&mntvnode_mtx); 3055 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3056 if (n == len) 3057 break; 3058 vref(vp); 3059 xvn[n].xv_size = sizeof *xvn; 3060 xvn[n].xv_vnode = vp; 3061#define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3062 XV_COPY(usecount); 3063 XV_COPY(writecount); 3064 XV_COPY(holdcnt); 3065 XV_COPY(id); 3066 XV_COPY(mount); 3067 XV_COPY(numoutput); 3068 XV_COPY(type); 3069#undef XV_COPY 3070 xvn[n].xv_flag = vp->v_vflag; 3071 3072 switch (vp->v_type) { 3073 case VREG: 3074 case VDIR: 3075 case VLNK: 3076 xvn[n].xv_dev = vp->v_cachedfs; 3077 xvn[n].xv_ino = vp->v_cachedid; 3078 break; 3079 case VBLK: 3080 case VCHR: 3081 if (vp->v_rdev == NULL) { 3082 vrele(vp); 3083 continue; 3084 } 3085 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3086 break; 3087 case VSOCK: 3088 xvn[n].xv_socket = vp->v_socket; 3089 break; 3090 case VFIFO: 3091 xvn[n].xv_fifo = vp->v_fifoinfo; 3092 break; 3093 case VNON: 3094 case VBAD: 3095 default: 3096 /* shouldn't happen? */ 3097 vrele(vp); 3098 continue; 3099 } 3100 vrele(vp); 3101 ++n; 3102 } 3103 mtx_unlock(&mntvnode_mtx); 3104 mtx_lock(&mountlist_mtx); 3105 vfs_unbusy(mp, td); 3106 if (n == len) 3107 break; 3108 } 3109 mtx_unlock(&mountlist_mtx); 3110 3111 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3112 free(xvn, M_TEMP); 3113 return (error); 3114} 3115 3116SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 3117 0, 0, sysctl_vnode, "S,xvnode", ""); 3118#endif 3119 3120/* 3121 * Check to see if a filesystem is mounted on a block device. 3122 */ 3123int 3124vfs_mountedon(vp) 3125 struct vnode *vp; 3126{ 3127 3128 if (vp->v_rdev->si_mountpoint != NULL) 3129 return (EBUSY); 3130 return (0); 3131} 3132 3133/* 3134 * Unmount all filesystems. The list is traversed in reverse order 3135 * of mounting to avoid dependencies. 3136 */ 3137void 3138vfs_unmountall() 3139{ 3140 struct mount *mp; 3141 struct thread *td; 3142 int error; 3143 3144 if (curthread != NULL) 3145 td = curthread; 3146 else 3147 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 3148 /* 3149 * Since this only runs when rebooting, it is not interlocked. 3150 */ 3151 while(!TAILQ_EMPTY(&mountlist)) { 3152 mp = TAILQ_LAST(&mountlist, mntlist); 3153 error = dounmount(mp, MNT_FORCE, td); 3154 if (error) { 3155 TAILQ_REMOVE(&mountlist, mp, mnt_list); 3156 printf("unmount of %s failed (", 3157 mp->mnt_stat.f_mntonname); 3158 if (error == EBUSY) 3159 printf("BUSY)\n"); 3160 else 3161 printf("%d)\n", error); 3162 } else { 3163 /* The unmount has removed mp from the mountlist */ 3164 } 3165 } 3166} 3167 3168/* 3169 * perform msync on all vnodes under a mount point 3170 * the mount point must be locked. 3171 */ 3172void 3173vfs_msync(struct mount *mp, int flags) 3174{ 3175 struct vnode *vp, *nvp; 3176 struct vm_object *obj; 3177 int tries; 3178 3179 GIANT_REQUIRED; 3180 3181 tries = 5; 3182 mtx_lock(&mntvnode_mtx); 3183loop: 3184 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 3185 if (vp->v_mount != mp) { 3186 if (--tries > 0) 3187 goto loop; 3188 break; 3189 } 3190 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 3191 3192 VI_LOCK(vp); 3193 if (vp->v_iflag & VI_XLOCK) { /* XXX: what if MNT_WAIT? */ 3194 VI_UNLOCK(vp); 3195 continue; 3196 } 3197 3198 if ((vp->v_iflag & VI_OBJDIRTY) && 3199 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 3200 mtx_unlock(&mntvnode_mtx); 3201 if (!vget(vp, 3202 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3203 curthread)) { 3204 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3205 vput(vp); 3206 mtx_lock(&mntvnode_mtx); 3207 continue; 3208 } 3209 3210 if (VOP_GETVOBJECT(vp, &obj) == 0) { 3211 VM_OBJECT_LOCK(obj); 3212 vm_object_page_clean(obj, 0, 0, 3213 flags == MNT_WAIT ? 3214 OBJPC_SYNC : OBJPC_NOSYNC); 3215 VM_OBJECT_UNLOCK(obj); 3216 } 3217 vput(vp); 3218 } 3219 mtx_lock(&mntvnode_mtx); 3220 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3221 if (--tries > 0) 3222 goto loop; 3223 break; 3224 } 3225 } else 3226 VI_UNLOCK(vp); 3227 } 3228 mtx_unlock(&mntvnode_mtx); 3229} 3230 3231/* 3232 * Create the VM object needed for VMIO and mmap support. This 3233 * is done for all VREG files in the system. Some filesystems might 3234 * afford the additional metadata buffering capability of the 3235 * VMIO code by making the device node be VMIO mode also. 3236 * 3237 * vp must be locked when vfs_object_create is called. 3238 */ 3239int 3240vfs_object_create(vp, td, cred) 3241 struct vnode *vp; 3242 struct thread *td; 3243 struct ucred *cred; 3244{ 3245 GIANT_REQUIRED; 3246 return (VOP_CREATEVOBJECT(vp, cred, td)); 3247} 3248 3249/* 3250 * Mark a vnode as free, putting it up for recycling. 3251 */ 3252void 3253vfree(vp) 3254 struct vnode *vp; 3255{ 3256 int s; 3257 3258 ASSERT_VI_LOCKED(vp, "vfree"); 3259 s = splbio(); 3260 mtx_lock(&vnode_free_list_mtx); 3261 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3262 if (vp->v_iflag & VI_AGE) { 3263 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3264 } else { 3265 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3266 } 3267 freevnodes++; 3268 mtx_unlock(&vnode_free_list_mtx); 3269 vp->v_iflag &= ~VI_AGE; 3270 vp->v_iflag |= VI_FREE; 3271 splx(s); 3272} 3273 3274/* 3275 * Opposite of vfree() - mark a vnode as in use. 3276 */ 3277void 3278vbusy(vp) 3279 struct vnode *vp; 3280{ 3281 int s; 3282 3283 s = splbio(); 3284 ASSERT_VI_LOCKED(vp, "vbusy"); 3285 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3286 3287 mtx_lock(&vnode_free_list_mtx); 3288 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3289 freevnodes--; 3290 mtx_unlock(&vnode_free_list_mtx); 3291 3292 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3293 splx(s); 3294} 3295 3296/* 3297 * Record a process's interest in events which might happen to 3298 * a vnode. Because poll uses the historic select-style interface 3299 * internally, this routine serves as both the ``check for any 3300 * pending events'' and the ``record my interest in future events'' 3301 * functions. (These are done together, while the lock is held, 3302 * to avoid race conditions.) 3303 */ 3304int 3305vn_pollrecord(vp, td, events) 3306 struct vnode *vp; 3307 struct thread *td; 3308 short events; 3309{ 3310 3311 if (vp->v_pollinfo == NULL) 3312 v_addpollinfo(vp); 3313 mtx_lock(&vp->v_pollinfo->vpi_lock); 3314 if (vp->v_pollinfo->vpi_revents & events) { 3315 /* 3316 * This leaves events we are not interested 3317 * in available for the other process which 3318 * which presumably had requested them 3319 * (otherwise they would never have been 3320 * recorded). 3321 */ 3322 events &= vp->v_pollinfo->vpi_revents; 3323 vp->v_pollinfo->vpi_revents &= ~events; 3324 3325 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3326 return events; 3327 } 3328 vp->v_pollinfo->vpi_events |= events; 3329 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3330 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3331 return 0; 3332} 3333 3334/* 3335 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3336 * it is possible for us to miss an event due to race conditions, but 3337 * that condition is expected to be rare, so for the moment it is the 3338 * preferred interface. 3339 */ 3340void 3341vn_pollevent(vp, events) 3342 struct vnode *vp; 3343 short events; 3344{ 3345 3346 if (vp->v_pollinfo == NULL) 3347 v_addpollinfo(vp); 3348 mtx_lock(&vp->v_pollinfo->vpi_lock); 3349 if (vp->v_pollinfo->vpi_events & events) { 3350 /* 3351 * We clear vpi_events so that we don't 3352 * call selwakeup() twice if two events are 3353 * posted before the polling process(es) is 3354 * awakened. This also ensures that we take at 3355 * most one selwakeup() if the polling process 3356 * is no longer interested. However, it does 3357 * mean that only one event can be noticed at 3358 * a time. (Perhaps we should only clear those 3359 * event bits which we note?) XXX 3360 */ 3361 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3362 vp->v_pollinfo->vpi_revents |= events; 3363 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3364 } 3365 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3366} 3367 3368/* 3369 * Wake up anyone polling on vp because it is being revoked. 3370 * This depends on dead_poll() returning POLLHUP for correct 3371 * behavior. 3372 */ 3373void 3374vn_pollgone(vp) 3375 struct vnode *vp; 3376{ 3377 3378 mtx_lock(&vp->v_pollinfo->vpi_lock); 3379 VN_KNOTE(vp, NOTE_REVOKE); 3380 if (vp->v_pollinfo->vpi_events) { 3381 vp->v_pollinfo->vpi_events = 0; 3382 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3383 } 3384 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3385} 3386 3387 3388 3389/* 3390 * Routine to create and manage a filesystem syncer vnode. 3391 */ 3392#define sync_close ((int (*)(struct vop_close_args *))nullop) 3393static int sync_fsync(struct vop_fsync_args *); 3394static int sync_inactive(struct vop_inactive_args *); 3395static int sync_reclaim(struct vop_reclaim_args *); 3396 3397static vop_t **sync_vnodeop_p; 3398static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3399 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3400 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3401 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3402 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3403 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3404 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3405 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3406 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3407 { NULL, NULL } 3408}; 3409static struct vnodeopv_desc sync_vnodeop_opv_desc = 3410 { &sync_vnodeop_p, sync_vnodeop_entries }; 3411 3412VNODEOP_SET(sync_vnodeop_opv_desc); 3413 3414/* 3415 * Create a new filesystem syncer vnode for the specified mount point. 3416 */ 3417int 3418vfs_allocate_syncvnode(mp) 3419 struct mount *mp; 3420{ 3421 struct vnode *vp; 3422 static long start, incr, next; 3423 int error; 3424 3425 /* Allocate a new vnode */ 3426 if ((error = getnewvnode("syncer", mp, sync_vnodeop_p, &vp)) != 0) { 3427 mp->mnt_syncer = NULL; 3428 return (error); 3429 } 3430 vp->v_type = VNON; 3431 /* 3432 * Place the vnode onto the syncer worklist. We attempt to 3433 * scatter them about on the list so that they will go off 3434 * at evenly distributed times even if all the filesystems 3435 * are mounted at once. 3436 */ 3437 next += incr; 3438 if (next == 0 || next > syncer_maxdelay) { 3439 start /= 2; 3440 incr /= 2; 3441 if (start == 0) { 3442 start = syncer_maxdelay / 2; 3443 incr = syncer_maxdelay; 3444 } 3445 next = start; 3446 } 3447 VI_LOCK(vp); 3448 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 3449 VI_UNLOCK(vp); 3450 mp->mnt_syncer = vp; 3451 return (0); 3452} 3453 3454/* 3455 * Do a lazy sync of the filesystem. 3456 */ 3457static int 3458sync_fsync(ap) 3459 struct vop_fsync_args /* { 3460 struct vnode *a_vp; 3461 struct ucred *a_cred; 3462 int a_waitfor; 3463 struct thread *a_td; 3464 } */ *ap; 3465{ 3466 struct vnode *syncvp = ap->a_vp; 3467 struct mount *mp = syncvp->v_mount; 3468 struct thread *td = ap->a_td; 3469 int error, asyncflag; 3470 3471 /* 3472 * We only need to do something if this is a lazy evaluation. 3473 */ 3474 if (ap->a_waitfor != MNT_LAZY) 3475 return (0); 3476 3477 /* 3478 * Move ourselves to the back of the sync list. 3479 */ 3480 VI_LOCK(syncvp); 3481 vn_syncer_add_to_worklist(syncvp, syncdelay); 3482 VI_UNLOCK(syncvp); 3483 3484 /* 3485 * Walk the list of vnodes pushing all that are dirty and 3486 * not already on the sync list. 3487 */ 3488 mtx_lock(&mountlist_mtx); 3489 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3490 mtx_unlock(&mountlist_mtx); 3491 return (0); 3492 } 3493 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3494 vfs_unbusy(mp, td); 3495 return (0); 3496 } 3497 asyncflag = mp->mnt_flag & MNT_ASYNC; 3498 mp->mnt_flag &= ~MNT_ASYNC; 3499 vfs_msync(mp, MNT_NOWAIT); 3500 error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3501 if (asyncflag) 3502 mp->mnt_flag |= MNT_ASYNC; 3503 vn_finished_write(mp); 3504 vfs_unbusy(mp, td); 3505 return (error); 3506} 3507 3508/* 3509 * The syncer vnode is no referenced. 3510 */ 3511static int 3512sync_inactive(ap) 3513 struct vop_inactive_args /* { 3514 struct vnode *a_vp; 3515 struct thread *a_td; 3516 } */ *ap; 3517{ 3518 3519 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3520 vgone(ap->a_vp); 3521 return (0); 3522} 3523 3524/* 3525 * The syncer vnode is no longer needed and is being decommissioned. 3526 * 3527 * Modifications to the worklist must be protected at splbio(). 3528 */ 3529static int 3530sync_reclaim(ap) 3531 struct vop_reclaim_args /* { 3532 struct vnode *a_vp; 3533 } */ *ap; 3534{ 3535 struct vnode *vp = ap->a_vp; 3536 int s; 3537 3538 s = splbio(); 3539 vp->v_mount->mnt_syncer = NULL; 3540 VI_LOCK(vp); 3541 if (vp->v_iflag & VI_ONWORKLST) { 3542 mtx_lock(&sync_mtx); 3543 LIST_REMOVE(vp, v_synclist); 3544 mtx_unlock(&sync_mtx); 3545 vp->v_iflag &= ~VI_ONWORKLST; 3546 } 3547 VI_UNLOCK(vp); 3548 splx(s); 3549 3550 return (0); 3551} 3552 3553/* 3554 * extract the dev_t from a VCHR 3555 */ 3556dev_t 3557vn_todev(vp) 3558 struct vnode *vp; 3559{ 3560 if (vp->v_type != VCHR) 3561 return (NODEV); 3562 return (vp->v_rdev); 3563} 3564 3565/* 3566 * Check if vnode represents a disk device 3567 */ 3568int 3569vn_isdisk(vp, errp) 3570 struct vnode *vp; 3571 int *errp; 3572{ 3573 struct cdevsw *cdevsw; 3574 3575 if (vp->v_type != VCHR) { 3576 if (errp != NULL) 3577 *errp = ENOTBLK; 3578 return (0); 3579 } 3580 if (vp->v_rdev == NULL) { 3581 if (errp != NULL) 3582 *errp = ENXIO; 3583 return (0); 3584 } 3585 cdevsw = devsw(vp->v_rdev); 3586 if (cdevsw == NULL) { 3587 if (errp != NULL) 3588 *errp = ENXIO; 3589 return (0); 3590 } 3591 if (!(cdevsw->d_flags & D_DISK)) { 3592 if (errp != NULL) 3593 *errp = ENOTBLK; 3594 return (0); 3595 } 3596 if (errp != NULL) 3597 *errp = 0; 3598 return (1); 3599} 3600 3601/* 3602 * Free data allocated by namei(); see namei(9) for details. 3603 */ 3604void 3605NDFREE(ndp, flags) 3606 struct nameidata *ndp; 3607 const uint flags; 3608{ 3609 if (!(flags & NDF_NO_FREE_PNBUF) && 3610 (ndp->ni_cnd.cn_flags & HASBUF)) { 3611 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3612 ndp->ni_cnd.cn_flags &= ~HASBUF; 3613 } 3614 if (!(flags & NDF_NO_DVP_UNLOCK) && 3615 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3616 ndp->ni_dvp != ndp->ni_vp) 3617 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3618 if (!(flags & NDF_NO_DVP_RELE) && 3619 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3620 vrele(ndp->ni_dvp); 3621 ndp->ni_dvp = NULL; 3622 } 3623 if (!(flags & NDF_NO_VP_UNLOCK) && 3624 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3625 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3626 if (!(flags & NDF_NO_VP_RELE) && 3627 ndp->ni_vp) { 3628 vrele(ndp->ni_vp); 3629 ndp->ni_vp = NULL; 3630 } 3631 if (!(flags & NDF_NO_STARTDIR_RELE) && 3632 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3633 vrele(ndp->ni_startdir); 3634 ndp->ni_startdir = NULL; 3635 } 3636} 3637 3638/* 3639 * Common filesystem object access control check routine. Accepts a 3640 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3641 * and optional call-by-reference privused argument allowing vaccess() 3642 * to indicate to the caller whether privilege was used to satisfy the 3643 * request (obsoleted). Returns 0 on success, or an errno on failure. 3644 */ 3645int 3646vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3647 enum vtype type; 3648 mode_t file_mode; 3649 uid_t file_uid; 3650 gid_t file_gid; 3651 mode_t acc_mode; 3652 struct ucred *cred; 3653 int *privused; 3654{ 3655 mode_t dac_granted; 3656#ifdef CAPABILITIES 3657 mode_t cap_granted; 3658#endif 3659 3660 /* 3661 * Look for a normal, non-privileged way to access the file/directory 3662 * as requested. If it exists, go with that. 3663 */ 3664 3665 if (privused != NULL) 3666 *privused = 0; 3667 3668 dac_granted = 0; 3669 3670 /* Check the owner. */ 3671 if (cred->cr_uid == file_uid) { 3672 dac_granted |= VADMIN; 3673 if (file_mode & S_IXUSR) 3674 dac_granted |= VEXEC; 3675 if (file_mode & S_IRUSR) 3676 dac_granted |= VREAD; 3677 if (file_mode & S_IWUSR) 3678 dac_granted |= (VWRITE | VAPPEND); 3679 3680 if ((acc_mode & dac_granted) == acc_mode) 3681 return (0); 3682 3683 goto privcheck; 3684 } 3685 3686 /* Otherwise, check the groups (first match) */ 3687 if (groupmember(file_gid, cred)) { 3688 if (file_mode & S_IXGRP) 3689 dac_granted |= VEXEC; 3690 if (file_mode & S_IRGRP) 3691 dac_granted |= VREAD; 3692 if (file_mode & S_IWGRP) 3693 dac_granted |= (VWRITE | VAPPEND); 3694 3695 if ((acc_mode & dac_granted) == acc_mode) 3696 return (0); 3697 3698 goto privcheck; 3699 } 3700 3701 /* Otherwise, check everyone else. */ 3702 if (file_mode & S_IXOTH) 3703 dac_granted |= VEXEC; 3704 if (file_mode & S_IROTH) 3705 dac_granted |= VREAD; 3706 if (file_mode & S_IWOTH) 3707 dac_granted |= (VWRITE | VAPPEND); 3708 if ((acc_mode & dac_granted) == acc_mode) 3709 return (0); 3710 3711privcheck: 3712 if (!suser_cred(cred, PRISON_ROOT)) { 3713 /* XXX audit: privilege used */ 3714 if (privused != NULL) 3715 *privused = 1; 3716 return (0); 3717 } 3718 3719#ifdef CAPABILITIES 3720 /* 3721 * Build a capability mask to determine if the set of capabilities 3722 * satisfies the requirements when combined with the granted mask 3723 * from above. 3724 * For each capability, if the capability is required, bitwise 3725 * or the request type onto the cap_granted mask. 3726 */ 3727 cap_granted = 0; 3728 3729 if (type == VDIR) { 3730 /* 3731 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3732 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3733 */ 3734 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3735 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3736 cap_granted |= VEXEC; 3737 } else { 3738 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3739 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3740 cap_granted |= VEXEC; 3741 } 3742 3743 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3744 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3745 cap_granted |= VREAD; 3746 3747 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3748 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3749 cap_granted |= (VWRITE | VAPPEND); 3750 3751 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3752 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3753 cap_granted |= VADMIN; 3754 3755 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3756 /* XXX audit: privilege used */ 3757 if (privused != NULL) 3758 *privused = 1; 3759 return (0); 3760 } 3761#endif 3762 3763 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3764} 3765 3766/* 3767 * Credential check based on process requesting service, and per-attribute 3768 * permissions. 3769 */ 3770int 3771extattr_check_cred(struct vnode *vp, int attrnamespace, 3772 struct ucred *cred, struct thread *td, int access) 3773{ 3774 3775 /* 3776 * Kernel-invoked always succeeds. 3777 */ 3778 if (cred == NOCRED) 3779 return (0); 3780 3781 /* 3782 * Do not allow privileged processes in jail to directly 3783 * manipulate system attributes. 3784 * 3785 * XXX What capability should apply here? 3786 * Probably CAP_SYS_SETFFLAG. 3787 */ 3788 switch (attrnamespace) { 3789 case EXTATTR_NAMESPACE_SYSTEM: 3790 /* Potentially should be: return (EPERM); */ 3791 return (suser_cred(cred, 0)); 3792 case EXTATTR_NAMESPACE_USER: 3793 return (VOP_ACCESS(vp, access, cred, td)); 3794 default: 3795 return (EPERM); 3796 } 3797} 3798