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