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, take; 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 wakeup(&vnlruproc_sig); 756 tsleep(vnlruproc, PVFS, "vlruwt", hz); 757 continue; 758 } 759 mtx_unlock(&vnode_free_list_mtx); 760 done = 0; 761 mtx_lock(&mountlist_mtx); 762 take = 0; 763 TAILQ_FOREACH(mp, &mountlist, mnt_list) 764 take++; 765 take = desiredvnodes / (take * 10); 766 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 767 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 768 nmp = TAILQ_NEXT(mp, mnt_list); 769 continue; 770 } 771 done += vlrureclaim(mp, take); 772 mtx_lock(&mountlist_mtx); 773 nmp = TAILQ_NEXT(mp, mnt_list); 774 vfs_unbusy(mp, td); 775 } 776 mtx_unlock(&mountlist_mtx); 777 if (done == 0) { 778 #if 0 779 /* These messages are temporary debugging aids */ 780 if (vnlru_nowhere < 5) 781 printf("vnlru process getting nowhere..\n"); 782 else if (vnlru_nowhere == 5) 783 printf("vnlru process messages stopped.\n"); 784 #endif 785 vnlru_nowhere++; 786 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 787 } 788 } 789 splx(s); 790 } 791 792 static struct kproc_desc vnlru_kp = { 793 "vnlru", 794 vnlru_proc, 795 &vnlruproc 796 }; 797 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 798 799 800 /* 801 * Routines having to do with the management of the vnode table. 802 */ 803 804 /* 805 * Check to see if a free vnode can be recycled. If it can, 806 * return it locked with the vn lock, but not interlock. Also 807 * get the vn_start_write lock. Otherwise indicate the error. 808 */ 809 static int 810 vcanrecycle(struct vnode *vp, struct mount **vnmpp) 811 { 812 struct thread *td = curthread; 813 vm_object_t object; 814 int error; 815 816 /* Don't recycle if we can't get the interlock */ 817 if (!VI_TRYLOCK(vp)) 818 return (EWOULDBLOCK); 819 820 /* We should be able to immediately acquire this */ 821 /* XXX This looks like it should panic if it fails */ 822 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td) != 0) { 823 if (VOP_ISLOCKED(vp, td)) 824 panic("vcanrecycle: locked vnode"); 825 return (EWOULDBLOCK); 826 } 827 828 /* 829 * Don't recycle if its filesystem is being suspended. 830 */ 831 if (vn_start_write(vp, vnmpp, V_NOWAIT) != 0) { 832 error = EBUSY; 833 goto done; 834 } 835 836 /* 837 * Don't recycle if we still have cached pages. 838 */ 839 if (VOP_GETVOBJECT(vp, &object) == 0 && 840 (object->resident_page_count || 841 object->ref_count)) { 842 error = EBUSY; 843 goto done; 844 } 845 if (LIST_FIRST(&vp->v_cache_src)) { 846 /* 847 * note: nameileafonly sysctl is temporary, 848 * for debugging only, and will eventually be 849 * removed. 850 */ 851 if (nameileafonly > 0) { 852 /* 853 * Do not reuse namei-cached directory 854 * vnodes that have cached 855 * subdirectories. 856 */ 857 if (cache_leaf_test(vp) < 0) { 858 error = EISDIR; 859 goto done; 860 } 861 } else if (nameileafonly < 0 || 862 vmiodirenable == 0) { 863 /* 864 * Do not reuse namei-cached directory 865 * vnodes if nameileafonly is -1 or 866 * if VMIO backing for directories is 867 * turned off (otherwise we reuse them 868 * too quickly). 869 */ 870 error = EBUSY; 871 goto done; 872 } 873 } 874 return (0); 875 done: 876 VOP_UNLOCK(vp, 0, td); 877 return (error); 878 } 879 880 /* 881 * Return the next vnode from the free list. 882 */ 883 int 884 getnewvnode(tag, mp, vops, vpp) 885 const char *tag; 886 struct mount *mp; 887 vop_t **vops; 888 struct vnode **vpp; 889 { 890 int s; 891 struct thread *td = curthread; /* XXX */ 892 struct vnode *vp = NULL; 893 struct vpollinfo *pollinfo = NULL; 894 struct mount *vnmp; 895 896 s = splbio(); 897 mtx_lock(&vnode_free_list_mtx); 898 899 /* 900 * Try to reuse vnodes if we hit the max. This situation only 901 * occurs in certain large-memory (2G+) situations. We cannot 902 * attempt to directly reclaim vnodes due to nasty recursion 903 * problems. 904 */ 905 while (numvnodes - freevnodes > desiredvnodes) { 906 if (vnlruproc_sig == 0) { 907 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 908 wakeup(vnlruproc); 909 } 910 mtx_unlock(&vnode_free_list_mtx); 911 tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); 912 mtx_lock(&vnode_free_list_mtx); 913 } 914 915 /* 916 * Attempt to reuse a vnode already on the free list, allocating 917 * a new vnode if we can't find one or if we have not reached a 918 * good minimum for good LRU performance. 919 */ 920 921 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 922 int error; 923 int count; 924 925 for (count = 0; count < freevnodes; count++) { 926 vp = TAILQ_FIRST(&vnode_free_list); 927 928 KASSERT(vp->v_usecount == 0 && 929 (vp->v_iflag & VI_DOINGINACT) == 0, 930 ("getnewvnode: free vnode isn't")); 931 932 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 933 /* 934 * We have to drop the free list mtx to avoid lock 935 * order reversals with interlock. 936 */ 937 mtx_unlock(&vnode_free_list_mtx); 938 error = vcanrecycle(vp, &vnmp); 939 mtx_lock(&vnode_free_list_mtx); 940 if (error == 0) 941 break; 942 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 943 vp = NULL; 944 } 945 } 946 if (vp) { 947 freevnodes--; 948 mtx_unlock(&vnode_free_list_mtx); 949 950 cache_purge(vp); 951 VI_LOCK(vp); 952 vp->v_iflag |= VI_DOOMED; 953 vp->v_iflag &= ~VI_FREE; 954 if (vp->v_type != VBAD) { 955 VOP_UNLOCK(vp, 0, td); 956 vgonel(vp, td); 957 VI_LOCK(vp); 958 } else { 959 VOP_UNLOCK(vp, 0, td); 960 } 961 vn_finished_write(vnmp); 962 963 #ifdef INVARIANTS 964 { 965 if (vp->v_data) 966 panic("cleaned vnode isn't"); 967 if (vp->v_numoutput) 968 panic("Clean vnode has pending I/O's"); 969 if (vp->v_writecount != 0) 970 panic("Non-zero write count"); 971 } 972 #endif 973 if ((pollinfo = vp->v_pollinfo) != NULL) { 974 /* 975 * To avoid lock order reversals, the call to 976 * uma_zfree() must be delayed until the vnode 977 * interlock is released. 978 */ 979 vp->v_pollinfo = NULL; 980 } 981 #ifdef MAC 982 mac_destroy_vnode(vp); 983 #endif 984 vp->v_iflag = 0; 985 vp->v_vflag = 0; 986 vp->v_lastw = 0; 987 vp->v_lasta = 0; 988 vp->v_cstart = 0; 989 vp->v_clen = 0; 990 vp->v_socket = 0; 991 lockdestroy(vp->v_vnlock); 992 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 993 KASSERT(vp->v_cleanbufcnt == 0, ("cleanbufcnt not 0")); 994 KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); 995 KASSERT(vp->v_dirtybufcnt == 0, ("dirtybufcnt not 0")); 996 KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); 997 } else { 998 numvnodes++; 999 mtx_unlock(&vnode_free_list_mtx); 1000 1001 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 1002 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 1003 VI_LOCK(vp); 1004 vp->v_dd = vp; 1005 vp->v_vnlock = &vp->v_lock; 1006 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 1007 cache_purge(vp); 1008 LIST_INIT(&vp->v_cache_src); 1009 TAILQ_INIT(&vp->v_cache_dst); 1010 } 1011 1012 TAILQ_INIT(&vp->v_cleanblkhd); 1013 TAILQ_INIT(&vp->v_dirtyblkhd); 1014 vp->v_type = VNON; 1015 vp->v_tag = tag; 1016 vp->v_op = vops; 1017 *vpp = vp; 1018 vp->v_usecount = 1; 1019 vp->v_data = 0; 1020 vp->v_cachedid = -1; 1021 VI_UNLOCK(vp); 1022 if (pollinfo != NULL) { 1023 mtx_destroy(&pollinfo->vpi_lock); 1024 uma_zfree(vnodepoll_zone, pollinfo); 1025 } 1026 #ifdef MAC 1027 mac_init_vnode(vp); 1028 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1029 mac_associate_vnode_singlelabel(mp, vp); 1030 #endif 1031 insmntque(vp, mp); 1032 1033 return (0); 1034 } 1035 1036 /* 1037 * Move a vnode from one mount queue to another. 1038 */ 1039 static void 1040 insmntque(vp, mp) 1041 register struct vnode *vp; 1042 register struct mount *mp; 1043 { 1044 1045 mtx_lock(&mntvnode_mtx); 1046 /* 1047 * Delete from old mount point vnode list, if on one. 1048 */ 1049 if (vp->v_mount != NULL) 1050 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 1051 /* 1052 * Insert into list of vnodes for the new mount point, if available. 1053 */ 1054 if ((vp->v_mount = mp) == NULL) { 1055 mtx_unlock(&mntvnode_mtx); 1056 return; 1057 } 1058 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1059 mtx_unlock(&mntvnode_mtx); 1060 } 1061 1062 /* 1063 * Update outstanding I/O count and do wakeup if requested. 1064 */ 1065 void 1066 vwakeup(bp) 1067 register struct buf *bp; 1068 { 1069 register struct vnode *vp; 1070 1071 bp->b_flags &= ~B_WRITEINPROG; 1072 if ((vp = bp->b_vp)) { 1073 VI_LOCK(vp); 1074 vp->v_numoutput--; 1075 if (vp->v_numoutput < 0) 1076 panic("vwakeup: neg numoutput"); 1077 if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) { 1078 vp->v_iflag &= ~VI_BWAIT; 1079 wakeup(&vp->v_numoutput); 1080 } 1081 VI_UNLOCK(vp); 1082 } 1083 } 1084 1085 /* 1086 * Flush out and invalidate all buffers associated with a vnode. 1087 * Called with the underlying object locked. 1088 */ 1089 int 1090 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 1091 struct vnode *vp; 1092 int flags; 1093 struct ucred *cred; 1094 struct thread *td; 1095 int slpflag, slptimeo; 1096 { 1097 struct buf *blist; 1098 int s, error; 1099 vm_object_t object; 1100 1101 GIANT_REQUIRED; 1102 1103 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1104 1105 VI_LOCK(vp); 1106 if (flags & V_SAVE) { 1107 s = splbio(); 1108 while (vp->v_numoutput) { 1109 vp->v_iflag |= VI_BWAIT; 1110 error = msleep(&vp->v_numoutput, VI_MTX(vp), 1111 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 1112 if (error) { 1113 VI_UNLOCK(vp); 1114 splx(s); 1115 return (error); 1116 } 1117 } 1118 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1119 splx(s); 1120 VI_UNLOCK(vp); 1121 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 1122 return (error); 1123 /* 1124 * XXX We could save a lock/unlock if this was only 1125 * enabled under INVARIANTS 1126 */ 1127 VI_LOCK(vp); 1128 s = splbio(); 1129 if (vp->v_numoutput > 0 || 1130 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 1131 panic("vinvalbuf: dirty bufs"); 1132 } 1133 splx(s); 1134 } 1135 s = splbio(); 1136 /* 1137 * If you alter this loop please notice that interlock is dropped and 1138 * reacquired in flushbuflist. Special care is needed to ensure that 1139 * no race conditions occur from this. 1140 */ 1141 for (error = 0;;) { 1142 if ((blist = TAILQ_FIRST(&vp->v_cleanblkhd)) != 0 && 1143 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 1144 if (error) 1145 break; 1146 continue; 1147 } 1148 if ((blist = TAILQ_FIRST(&vp->v_dirtyblkhd)) != 0 && 1149 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 1150 if (error) 1151 break; 1152 continue; 1153 } 1154 break; 1155 } 1156 if (error) { 1157 splx(s); 1158 VI_UNLOCK(vp); 1159 return (error); 1160 } 1161 1162 /* 1163 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1164 * have write I/O in-progress but if there is a VM object then the 1165 * VM object can also have read-I/O in-progress. 1166 */ 1167 do { 1168 while (vp->v_numoutput > 0) { 1169 vp->v_iflag |= VI_BWAIT; 1170 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0); 1171 } 1172 VI_UNLOCK(vp); 1173 if (VOP_GETVOBJECT(vp, &object) == 0) { 1174 while (object->paging_in_progress) 1175 vm_object_pip_sleep(object, "vnvlbx"); 1176 } 1177 VI_LOCK(vp); 1178 } while (vp->v_numoutput > 0); 1179 VI_UNLOCK(vp); 1180 1181 splx(s); 1182 1183 /* 1184 * Destroy the copy in the VM cache, too. 1185 */ 1186 if (VOP_GETVOBJECT(vp, &object) == 0) { 1187 vm_object_lock(object); 1188 vm_object_page_remove(object, 0, 0, 1189 (flags & V_SAVE) ? TRUE : FALSE); 1190 vm_object_unlock(object); 1191 } 1192 1193 #ifdef INVARIANTS 1194 VI_LOCK(vp); 1195 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1196 (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || 1197 !TAILQ_EMPTY(&vp->v_cleanblkhd))) 1198 panic("vinvalbuf: flush failed"); 1199 VI_UNLOCK(vp); 1200 #endif 1201 return (0); 1202 } 1203 1204 /* 1205 * Flush out buffers on the specified list. 1206 * 1207 */ 1208 static int 1209 flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) 1210 struct buf *blist; 1211 int flags; 1212 struct vnode *vp; 1213 int slpflag, slptimeo; 1214 int *errorp; 1215 { 1216 struct buf *bp, *nbp; 1217 int found, error; 1218 1219 ASSERT_VI_LOCKED(vp, "flushbuflist"); 1220 1221 for (found = 0, bp = blist; bp; bp = nbp) { 1222 nbp = TAILQ_NEXT(bp, b_vnbufs); 1223 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1224 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1225 continue; 1226 } 1227 found += 1; 1228 error = BUF_TIMELOCK(bp, 1229 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), 1230 "flushbuf", slpflag, slptimeo); 1231 if (error) { 1232 if (error != ENOLCK) 1233 *errorp = error; 1234 goto done; 1235 } 1236 /* 1237 * XXX Since there are no node locks for NFS, I 1238 * believe there is a slight chance that a delayed 1239 * write will occur while sleeping just above, so 1240 * check for it. Note that vfs_bio_awrite expects 1241 * buffers to reside on a queue, while BUF_WRITE and 1242 * brelse do not. 1243 */ 1244 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1245 (flags & V_SAVE)) { 1246 1247 if (bp->b_vp == vp) { 1248 if (bp->b_flags & B_CLUSTEROK) { 1249 BUF_UNLOCK(bp); 1250 vfs_bio_awrite(bp); 1251 } else { 1252 bremfree(bp); 1253 bp->b_flags |= B_ASYNC; 1254 BUF_WRITE(bp); 1255 } 1256 } else { 1257 bremfree(bp); 1258 (void) BUF_WRITE(bp); 1259 } 1260 goto done; 1261 } 1262 bremfree(bp); 1263 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1264 bp->b_flags &= ~B_ASYNC; 1265 brelse(bp); 1266 VI_LOCK(vp); 1267 } 1268 return (found); 1269 done: 1270 VI_LOCK(vp); 1271 return (found); 1272 } 1273 1274 /* 1275 * Truncate a file's buffer and pages to a specified length. This 1276 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1277 * sync activity. 1278 */ 1279 int 1280 vtruncbuf(vp, cred, td, length, blksize) 1281 register struct vnode *vp; 1282 struct ucred *cred; 1283 struct thread *td; 1284 off_t length; 1285 int blksize; 1286 { 1287 register struct buf *bp; 1288 struct buf *nbp; 1289 int s, anyfreed; 1290 int trunclbn; 1291 1292 /* 1293 * Round up to the *next* lbn. 1294 */ 1295 trunclbn = (length + blksize - 1) / blksize; 1296 1297 s = splbio(); 1298 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1299 restart: 1300 VI_LOCK(vp); 1301 anyfreed = 1; 1302 for (;anyfreed;) { 1303 anyfreed = 0; 1304 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 1305 nbp = TAILQ_NEXT(bp, b_vnbufs); 1306 if (bp->b_lblkno >= trunclbn) { 1307 if (BUF_LOCK(bp, 1308 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1309 VI_MTX(vp)) == ENOLCK) 1310 goto restart; 1311 1312 bremfree(bp); 1313 bp->b_flags |= (B_INVAL | B_RELBUF); 1314 bp->b_flags &= ~B_ASYNC; 1315 brelse(bp); 1316 anyfreed = 1; 1317 1318 if (nbp && 1319 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1320 (nbp->b_vp != vp) || 1321 (nbp->b_flags & B_DELWRI))) { 1322 goto restart; 1323 } 1324 VI_LOCK(vp); 1325 } 1326 } 1327 1328 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1329 nbp = TAILQ_NEXT(bp, b_vnbufs); 1330 if (bp->b_lblkno >= trunclbn) { 1331 if (BUF_LOCK(bp, 1332 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1333 VI_MTX(vp)) == ENOLCK) 1334 goto restart; 1335 bremfree(bp); 1336 bp->b_flags |= (B_INVAL | B_RELBUF); 1337 bp->b_flags &= ~B_ASYNC; 1338 brelse(bp); 1339 anyfreed = 1; 1340 if (nbp && 1341 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1342 (nbp->b_vp != vp) || 1343 (nbp->b_flags & B_DELWRI) == 0)) { 1344 goto restart; 1345 } 1346 VI_LOCK(vp); 1347 } 1348 } 1349 } 1350 1351 if (length > 0) { 1352 restartsync: 1353 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1354 nbp = TAILQ_NEXT(bp, b_vnbufs); 1355 if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) { 1356 if (BUF_LOCK(bp, 1357 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1358 VI_MTX(vp)) == ENOLCK) 1359 goto restart; 1360 bremfree(bp); 1361 if (bp->b_vp == vp) 1362 bp->b_flags |= B_ASYNC; 1363 else 1364 bp->b_flags &= ~B_ASYNC; 1365 1366 BUF_WRITE(bp); 1367 VI_LOCK(vp); 1368 goto restartsync; 1369 } 1370 } 1371 } 1372 1373 while (vp->v_numoutput > 0) { 1374 vp->v_iflag |= VI_BWAIT; 1375 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0); 1376 } 1377 VI_UNLOCK(vp); 1378 splx(s); 1379 1380 vnode_pager_setsize(vp, length); 1381 1382 return (0); 1383 } 1384 1385 /* 1386 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1387 * a vnode. 1388 * 1389 * NOTE: We have to deal with the special case of a background bitmap 1390 * buffer, a situation where two buffers will have the same logical 1391 * block offset. We want (1) only the foreground buffer to be accessed 1392 * in a lookup and (2) must differentiate between the foreground and 1393 * background buffer in the splay tree algorithm because the splay 1394 * tree cannot normally handle multiple entities with the same 'index'. 1395 * We accomplish this by adding differentiating flags to the splay tree's 1396 * numerical domain. 1397 */ 1398 static 1399 struct buf * 1400 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1401 { 1402 struct buf dummy; 1403 struct buf *lefttreemax, *righttreemin, *y; 1404 1405 if (root == NULL) 1406 return (NULL); 1407 lefttreemax = righttreemin = &dummy; 1408 for (;;) { 1409 if (lblkno < root->b_lblkno || 1410 (lblkno == root->b_lblkno && 1411 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1412 if ((y = root->b_left) == NULL) 1413 break; 1414 if (lblkno < y->b_lblkno) { 1415 /* Rotate right. */ 1416 root->b_left = y->b_right; 1417 y->b_right = root; 1418 root = y; 1419 if ((y = root->b_left) == NULL) 1420 break; 1421 } 1422 /* Link into the new root's right tree. */ 1423 righttreemin->b_left = root; 1424 righttreemin = root; 1425 } else if (lblkno > root->b_lblkno || 1426 (lblkno == root->b_lblkno && 1427 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1428 if ((y = root->b_right) == NULL) 1429 break; 1430 if (lblkno > y->b_lblkno) { 1431 /* Rotate left. */ 1432 root->b_right = y->b_left; 1433 y->b_left = root; 1434 root = y; 1435 if ((y = root->b_right) == NULL) 1436 break; 1437 } 1438 /* Link into the new root's left tree. */ 1439 lefttreemax->b_right = root; 1440 lefttreemax = root; 1441 } else { 1442 break; 1443 } 1444 root = y; 1445 } 1446 /* Assemble the new root. */ 1447 lefttreemax->b_right = root->b_left; 1448 righttreemin->b_left = root->b_right; 1449 root->b_left = dummy.b_right; 1450 root->b_right = dummy.b_left; 1451 return (root); 1452 } 1453 1454 static 1455 void 1456 buf_vlist_remove(struct buf *bp) 1457 { 1458 struct vnode *vp = bp->b_vp; 1459 struct buf *root; 1460 1461 ASSERT_VI_LOCKED(vp, "buf_vlist_remove"); 1462 if (bp->b_xflags & BX_VNDIRTY) { 1463 if (bp != vp->v_dirtyblkroot) { 1464 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1465 KASSERT(root == bp, ("splay lookup failed during dirty remove")); 1466 } 1467 if (bp->b_left == NULL) { 1468 root = bp->b_right; 1469 } else { 1470 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1471 root->b_right = bp->b_right; 1472 } 1473 vp->v_dirtyblkroot = root; 1474 TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); 1475 vp->v_dirtybufcnt--; 1476 } else { 1477 /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ 1478 if (bp != vp->v_cleanblkroot) { 1479 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1480 KASSERT(root == bp, ("splay lookup failed during clean remove")); 1481 } 1482 if (bp->b_left == NULL) { 1483 root = bp->b_right; 1484 } else { 1485 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1486 root->b_right = bp->b_right; 1487 } 1488 vp->v_cleanblkroot = root; 1489 TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); 1490 vp->v_cleanbufcnt--; 1491 } 1492 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1493 } 1494 1495 /* 1496 * Add the buffer to the sorted clean or dirty block list using a 1497 * splay tree algorithm. 1498 * 1499 * NOTE: xflags is passed as a constant, optimizing this inline function! 1500 */ 1501 static 1502 void 1503 buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) 1504 { 1505 struct buf *root; 1506 1507 ASSERT_VI_LOCKED(vp, "buf_vlist_add"); 1508 bp->b_xflags |= xflags; 1509 if (xflags & BX_VNDIRTY) { 1510 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1511 if (root == NULL) { 1512 bp->b_left = NULL; 1513 bp->b_right = NULL; 1514 TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); 1515 } else if (bp->b_lblkno < root->b_lblkno || 1516 (bp->b_lblkno == root->b_lblkno && 1517 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1518 bp->b_left = root->b_left; 1519 bp->b_right = root; 1520 root->b_left = NULL; 1521 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1522 } else { 1523 bp->b_right = root->b_right; 1524 bp->b_left = root; 1525 root->b_right = NULL; 1526 TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, 1527 root, bp, b_vnbufs); 1528 } 1529 vp->v_dirtybufcnt++; 1530 vp->v_dirtyblkroot = bp; 1531 } else { 1532 /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ 1533 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1534 if (root == NULL) { 1535 bp->b_left = NULL; 1536 bp->b_right = NULL; 1537 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1538 } else if (bp->b_lblkno < root->b_lblkno || 1539 (bp->b_lblkno == root->b_lblkno && 1540 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1541 bp->b_left = root->b_left; 1542 bp->b_right = root; 1543 root->b_left = NULL; 1544 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1545 } else { 1546 bp->b_right = root->b_right; 1547 bp->b_left = root; 1548 root->b_right = NULL; 1549 TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, 1550 root, bp, b_vnbufs); 1551 } 1552 vp->v_cleanbufcnt++; 1553 vp->v_cleanblkroot = bp; 1554 } 1555 } 1556 1557 /* 1558 * Lookup a buffer using the splay tree. Note that we specifically avoid 1559 * shadow buffers used in background bitmap writes. 1560 * 1561 * This code isn't quite efficient as it could be because we are maintaining 1562 * two sorted lists and do not know which list the block resides in. 1563 */ 1564 struct buf * 1565 gbincore(struct vnode *vp, daddr_t lblkno) 1566 { 1567 struct buf *bp; 1568 1569 GIANT_REQUIRED; 1570 1571 ASSERT_VI_LOCKED(vp, "gbincore"); 1572 bp = vp->v_cleanblkroot = buf_splay(lblkno, 0, vp->v_cleanblkroot); 1573 if (bp && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1574 return(bp); 1575 bp = vp->v_dirtyblkroot = buf_splay(lblkno, 0, vp->v_dirtyblkroot); 1576 if (bp && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1577 return(bp); 1578 return(NULL); 1579 } 1580 1581 /* 1582 * Associate a buffer with a vnode. 1583 */ 1584 void 1585 bgetvp(vp, bp) 1586 register struct vnode *vp; 1587 register struct buf *bp; 1588 { 1589 int s; 1590 1591 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1592 1593 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1594 ("bgetvp: bp already attached! %p", bp)); 1595 1596 ASSERT_VI_LOCKED(vp, "bgetvp"); 1597 vholdl(vp); 1598 bp->b_vp = vp; 1599 bp->b_dev = vn_todev(vp); 1600 /* 1601 * Insert onto list for new vnode. 1602 */ 1603 s = splbio(); 1604 buf_vlist_add(bp, vp, BX_VNCLEAN); 1605 splx(s); 1606 } 1607 1608 /* 1609 * Disassociate a buffer from a vnode. 1610 */ 1611 void 1612 brelvp(bp) 1613 register struct buf *bp; 1614 { 1615 struct vnode *vp; 1616 int s; 1617 1618 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1619 1620 /* 1621 * Delete from old vnode list, if on one. 1622 */ 1623 vp = bp->b_vp; 1624 s = splbio(); 1625 VI_LOCK(vp); 1626 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1627 buf_vlist_remove(bp); 1628 if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1629 vp->v_iflag &= ~VI_ONWORKLST; 1630 mtx_lock(&sync_mtx); 1631 LIST_REMOVE(vp, v_synclist); 1632 mtx_unlock(&sync_mtx); 1633 } 1634 vdropl(vp); 1635 VI_UNLOCK(vp); 1636 bp->b_vp = (struct vnode *) 0; 1637 if (bp->b_object) 1638 bp->b_object = NULL; 1639 splx(s); 1640 } 1641 1642 /* 1643 * Add an item to the syncer work queue. 1644 */ 1645 static void 1646 vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1647 { 1648 int s, slot; 1649 1650 s = splbio(); 1651 ASSERT_VI_LOCKED(vp, "vn_syncer_add_to_worklist"); 1652 1653 mtx_lock(&sync_mtx); 1654 if (vp->v_iflag & VI_ONWORKLST) 1655 LIST_REMOVE(vp, v_synclist); 1656 else 1657 vp->v_iflag |= VI_ONWORKLST; 1658 1659 if (delay > syncer_maxdelay - 2) 1660 delay = syncer_maxdelay - 2; 1661 slot = (syncer_delayno + delay) & syncer_mask; 1662 1663 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1664 mtx_unlock(&sync_mtx); 1665 1666 splx(s); 1667 } 1668 1669 struct proc *updateproc; 1670 static void sched_sync(void); 1671 static struct kproc_desc up_kp = { 1672 "syncer", 1673 sched_sync, 1674 &updateproc 1675 }; 1676 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1677 1678 /* 1679 * System filesystem synchronizer daemon. 1680 */ 1681 static void 1682 sched_sync(void) 1683 { 1684 struct synclist *slp; 1685 struct vnode *vp; 1686 struct mount *mp; 1687 long starttime; 1688 int s; 1689 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); /* XXXKSE */ 1690 1691 mtx_lock(&Giant); 1692 1693 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, 1694 SHUTDOWN_PRI_LAST); 1695 1696 for (;;) { 1697 kthread_suspend_check(td->td_proc); 1698 1699 starttime = time_second; 1700 1701 /* 1702 * Push files whose dirty time has expired. Be careful 1703 * of interrupt race on slp queue. 1704 */ 1705 s = splbio(); 1706 mtx_lock(&sync_mtx); 1707 slp = &syncer_workitem_pending[syncer_delayno]; 1708 syncer_delayno += 1; 1709 if (syncer_delayno == syncer_maxdelay) 1710 syncer_delayno = 0; 1711 splx(s); 1712 1713 while ((vp = LIST_FIRST(slp)) != NULL) { 1714 mtx_unlock(&sync_mtx); 1715 if (VOP_ISLOCKED(vp, NULL) == 0 && 1716 vn_start_write(vp, &mp, V_NOWAIT) == 0) { 1717 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1718 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1719 VOP_UNLOCK(vp, 0, td); 1720 vn_finished_write(mp); 1721 } 1722 s = splbio(); 1723 mtx_lock(&sync_mtx); 1724 if (LIST_FIRST(slp) == vp) { 1725 mtx_unlock(&sync_mtx); 1726 /* 1727 * Note: VFS vnodes can remain on the 1728 * worklist too with no dirty blocks, but 1729 * since sync_fsync() moves it to a different 1730 * slot we are safe. 1731 */ 1732 VI_LOCK(vp); 1733 if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && 1734 !vn_isdisk(vp, NULL)) { 1735 panic("sched_sync: fsync failed " 1736 "vp %p tag %s", vp, vp->v_tag); 1737 } 1738 /* 1739 * Put us back on the worklist. The worklist 1740 * routine will remove us from our current 1741 * position and then add us back in at a later 1742 * position. 1743 */ 1744 vn_syncer_add_to_worklist(vp, syncdelay); 1745 VI_UNLOCK(vp); 1746 mtx_lock(&sync_mtx); 1747 } 1748 splx(s); 1749 } 1750 mtx_unlock(&sync_mtx); 1751 1752 /* 1753 * Do soft update processing. 1754 */ 1755 if (softdep_process_worklist_hook != NULL) 1756 (*softdep_process_worklist_hook)(NULL); 1757 1758 /* 1759 * The variable rushjob allows the kernel to speed up the 1760 * processing of the filesystem syncer process. A rushjob 1761 * value of N tells the filesystem syncer to process the next 1762 * N seconds worth of work on its queue ASAP. Currently rushjob 1763 * is used by the soft update code to speed up the filesystem 1764 * syncer process when the incore state is getting so far 1765 * ahead of the disk that the kernel memory pool is being 1766 * threatened with exhaustion. 1767 */ 1768 mtx_lock(&sync_mtx); 1769 if (rushjob > 0) { 1770 rushjob -= 1; 1771 mtx_unlock(&sync_mtx); 1772 continue; 1773 } 1774 mtx_unlock(&sync_mtx); 1775 /* 1776 * If it has taken us less than a second to process the 1777 * current work, then wait. Otherwise start right over 1778 * again. We can still lose time if any single round 1779 * takes more than two seconds, but it does not really 1780 * matter as we are just trying to generally pace the 1781 * filesystem activity. 1782 */ 1783 if (time_second == starttime) 1784 tsleep(&lbolt, PPAUSE, "syncer", 0); 1785 } 1786 } 1787 1788 /* 1789 * Request the syncer daemon to speed up its work. 1790 * We never push it to speed up more than half of its 1791 * normal turn time, otherwise it could take over the cpu. 1792 * XXXKSE only one update? 1793 */ 1794 int 1795 speedup_syncer() 1796 { 1797 struct thread *td; 1798 int ret = 0; 1799 1800 td = FIRST_THREAD_IN_PROC(updateproc); 1801 mtx_lock_spin(&sched_lock); 1802 if (td->td_wchan == &lbolt) { 1803 unsleep(td); 1804 TD_CLR_SLEEPING(td); 1805 setrunnable(td); 1806 } 1807 mtx_unlock_spin(&sched_lock); 1808 mtx_lock(&sync_mtx); 1809 if (rushjob < syncdelay / 2) { 1810 rushjob += 1; 1811 stat_rush_requests += 1; 1812 ret = 1; 1813 } 1814 mtx_unlock(&sync_mtx); 1815 return (ret); 1816 } 1817 1818 /* 1819 * Associate a p-buffer with a vnode. 1820 * 1821 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1822 * with the buffer. i.e. the bp has not been linked into the vnode or 1823 * ref-counted. 1824 */ 1825 void 1826 pbgetvp(vp, bp) 1827 register struct vnode *vp; 1828 register struct buf *bp; 1829 { 1830 1831 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1832 1833 bp->b_vp = vp; 1834 bp->b_flags |= B_PAGING; 1835 bp->b_dev = vn_todev(vp); 1836 } 1837 1838 /* 1839 * Disassociate a p-buffer from a vnode. 1840 */ 1841 void 1842 pbrelvp(bp) 1843 register struct buf *bp; 1844 { 1845 1846 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1847 1848 /* XXX REMOVE ME */ 1849 VI_LOCK(bp->b_vp); 1850 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1851 panic( 1852 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1853 bp, 1854 (int)bp->b_flags 1855 ); 1856 } 1857 VI_UNLOCK(bp->b_vp); 1858 bp->b_vp = (struct vnode *) 0; 1859 bp->b_flags &= ~B_PAGING; 1860 } 1861 1862 /* 1863 * Reassign a buffer from one vnode to another. 1864 * Used to assign file specific control information 1865 * (indirect blocks) to the vnode to which they belong. 1866 */ 1867 void 1868 reassignbuf(bp, newvp) 1869 register struct buf *bp; 1870 register struct vnode *newvp; 1871 { 1872 int delay; 1873 int s; 1874 1875 if (newvp == NULL) { 1876 printf("reassignbuf: NULL"); 1877 return; 1878 } 1879 ++reassignbufcalls; 1880 1881 /* 1882 * B_PAGING flagged buffers cannot be reassigned because their vp 1883 * is not fully linked in. 1884 */ 1885 if (bp->b_flags & B_PAGING) 1886 panic("cannot reassign paging buffer"); 1887 1888 s = splbio(); 1889 /* 1890 * Delete from old vnode list, if on one. 1891 */ 1892 VI_LOCK(bp->b_vp); 1893 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1894 buf_vlist_remove(bp); 1895 if (bp->b_vp != newvp) { 1896 vdropl(bp->b_vp); 1897 bp->b_vp = NULL; /* for clarification */ 1898 } 1899 } 1900 VI_UNLOCK(bp->b_vp); 1901 /* 1902 * If dirty, put on list of dirty buffers; otherwise insert onto list 1903 * of clean buffers. 1904 */ 1905 VI_LOCK(newvp); 1906 if (bp->b_flags & B_DELWRI) { 1907 if ((newvp->v_iflag & VI_ONWORKLST) == 0) { 1908 switch (newvp->v_type) { 1909 case VDIR: 1910 delay = dirdelay; 1911 break; 1912 case VCHR: 1913 if (newvp->v_rdev->si_mountpoint != NULL) { 1914 delay = metadelay; 1915 break; 1916 } 1917 /* FALLTHROUGH */ 1918 default: 1919 delay = filedelay; 1920 } 1921 vn_syncer_add_to_worklist(newvp, delay); 1922 } 1923 buf_vlist_add(bp, newvp, BX_VNDIRTY); 1924 } else { 1925 buf_vlist_add(bp, newvp, BX_VNCLEAN); 1926 1927 if ((newvp->v_iflag & VI_ONWORKLST) && 1928 TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { 1929 mtx_lock(&sync_mtx); 1930 LIST_REMOVE(newvp, v_synclist); 1931 mtx_unlock(&sync_mtx); 1932 newvp->v_iflag &= ~VI_ONWORKLST; 1933 } 1934 } 1935 if (bp->b_vp != newvp) { 1936 bp->b_vp = newvp; 1937 vholdl(bp->b_vp); 1938 } 1939 VI_UNLOCK(newvp); 1940 splx(s); 1941 } 1942 1943 /* 1944 * Create a vnode for a device. 1945 * Used for mounting the root filesystem. 1946 */ 1947 int 1948 bdevvp(dev, vpp) 1949 dev_t dev; 1950 struct vnode **vpp; 1951 { 1952 register struct vnode *vp; 1953 struct vnode *nvp; 1954 int error; 1955 1956 if (dev == NODEV) { 1957 *vpp = NULLVP; 1958 return (ENXIO); 1959 } 1960 if (vfinddev(dev, VCHR, vpp)) 1961 return (0); 1962 error = getnewvnode("none", (struct mount *)0, spec_vnodeop_p, &nvp); 1963 if (error) { 1964 *vpp = NULLVP; 1965 return (error); 1966 } 1967 vp = nvp; 1968 vp->v_type = VCHR; 1969 addalias(vp, dev); 1970 *vpp = vp; 1971 return (0); 1972 } 1973 1974 static void 1975 v_incr_usecount(struct vnode *vp, int delta) 1976 { 1977 vp->v_usecount += delta; 1978 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1979 mtx_lock(&spechash_mtx); 1980 vp->v_rdev->si_usecount += delta; 1981 mtx_unlock(&spechash_mtx); 1982 } 1983 } 1984 1985 /* 1986 * Add vnode to the alias list hung off the dev_t. 1987 * 1988 * The reason for this gunk is that multiple vnodes can reference 1989 * the same physical device, so checking vp->v_usecount to see 1990 * how many users there are is inadequate; the v_usecount for 1991 * the vnodes need to be accumulated. vcount() does that. 1992 */ 1993 struct vnode * 1994 addaliasu(nvp, nvp_rdev) 1995 struct vnode *nvp; 1996 udev_t nvp_rdev; 1997 { 1998 struct vnode *ovp; 1999 vop_t **ops; 2000 dev_t dev; 2001 2002 if (nvp->v_type == VBLK) 2003 return (nvp); 2004 if (nvp->v_type != VCHR) 2005 panic("addaliasu on non-special vnode"); 2006 dev = udev2dev(nvp_rdev, 0); 2007 /* 2008 * Check to see if we have a bdevvp vnode with no associated 2009 * filesystem. If so, we want to associate the filesystem of 2010 * the new newly instigated vnode with the bdevvp vnode and 2011 * discard the newly created vnode rather than leaving the 2012 * bdevvp vnode lying around with no associated filesystem. 2013 */ 2014 if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { 2015 addalias(nvp, dev); 2016 return (nvp); 2017 } 2018 /* 2019 * Discard unneeded vnode, but save its node specific data. 2020 * Note that if there is a lock, it is carried over in the 2021 * node specific data to the replacement vnode. 2022 */ 2023 vref(ovp); 2024 ovp->v_data = nvp->v_data; 2025 ovp->v_tag = nvp->v_tag; 2026 nvp->v_data = NULL; 2027 lockdestroy(ovp->v_vnlock); 2028 lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, 2029 nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); 2030 ops = ovp->v_op; 2031 ovp->v_op = nvp->v_op; 2032 if (VOP_ISLOCKED(nvp, curthread)) { 2033 VOP_UNLOCK(nvp, 0, curthread); 2034 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 2035 } 2036 nvp->v_op = ops; 2037 insmntque(ovp, nvp->v_mount); 2038 vrele(nvp); 2039 vgone(nvp); 2040 return (ovp); 2041 } 2042 2043 /* This is a local helper function that do the same as addaliasu, but for a 2044 * dev_t instead of an udev_t. */ 2045 static void 2046 addalias(nvp, dev) 2047 struct vnode *nvp; 2048 dev_t dev; 2049 { 2050 2051 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 2052 nvp->v_rdev = dev; 2053 VI_LOCK(nvp); 2054 mtx_lock(&spechash_mtx); 2055 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 2056 dev->si_usecount += nvp->v_usecount; 2057 mtx_unlock(&spechash_mtx); 2058 VI_UNLOCK(nvp); 2059 } 2060 2061 /* 2062 * Grab a particular vnode from the free list, increment its 2063 * reference count and lock it. The vnode lock bit is set if the 2064 * vnode is being eliminated in vgone. The process is awakened 2065 * when the transition is completed, and an error returned to 2066 * indicate that the vnode is no longer usable (possibly having 2067 * been changed to a new filesystem type). 2068 */ 2069 int 2070 vget(vp, flags, td) 2071 register struct vnode *vp; 2072 int flags; 2073 struct thread *td; 2074 { 2075 int error; 2076 2077 /* 2078 * If the vnode is in the process of being cleaned out for 2079 * another use, we wait for the cleaning to finish and then 2080 * return failure. Cleaning is determined by checking that 2081 * the VI_XLOCK flag is set. 2082 */ 2083 if ((flags & LK_INTERLOCK) == 0) 2084 VI_LOCK(vp); 2085 if (vp->v_iflag & VI_XLOCK && vp->v_vxproc != curthread) { 2086 vp->v_iflag |= VI_XWANT; 2087 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); 2088 return (ENOENT); 2089 } 2090 2091 v_incr_usecount(vp, 1); 2092 2093 if (VSHOULDBUSY(vp)) 2094 vbusy(vp); 2095 if (flags & LK_TYPE_MASK) { 2096 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 2097 /* 2098 * must expand vrele here because we do not want 2099 * to call VOP_INACTIVE if the reference count 2100 * drops back to zero since it was never really 2101 * active. We must remove it from the free list 2102 * before sleeping so that multiple processes do 2103 * not try to recycle it. 2104 */ 2105 VI_LOCK(vp); 2106 v_incr_usecount(vp, -1); 2107 if (VSHOULDFREE(vp)) 2108 vfree(vp); 2109 else 2110 vlruvp(vp); 2111 VI_UNLOCK(vp); 2112 } 2113 return (error); 2114 } 2115 VI_UNLOCK(vp); 2116 return (0); 2117 } 2118 2119 /* 2120 * Increase the reference count of a vnode. 2121 */ 2122 void 2123 vref(struct vnode *vp) 2124 { 2125 VI_LOCK(vp); 2126 v_incr_usecount(vp, 1); 2127 VI_UNLOCK(vp); 2128 } 2129 2130 /* 2131 * Return reference count of a vnode. 2132 * 2133 * The results of this call are only guaranteed when some mechanism other 2134 * than the VI lock is used to stop other processes from gaining references 2135 * to the vnode. This may be the case if the caller holds the only reference. 2136 * This is also useful when stale data is acceptable as race conditions may 2137 * be accounted for by some other means. 2138 */ 2139 int 2140 vrefcnt(struct vnode *vp) 2141 { 2142 int usecnt; 2143 2144 VI_LOCK(vp); 2145 usecnt = vp->v_usecount; 2146 VI_UNLOCK(vp); 2147 2148 return (usecnt); 2149 } 2150 2151 2152 /* 2153 * Vnode put/release. 2154 * If count drops to zero, call inactive routine and return to freelist. 2155 */ 2156 void 2157 vrele(vp) 2158 struct vnode *vp; 2159 { 2160 struct thread *td = curthread; /* XXX */ 2161 2162 KASSERT(vp != NULL, ("vrele: null vp")); 2163 2164 VI_LOCK(vp); 2165 2166 /* Skip this v_writecount check if we're going to panic below. */ 2167 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2168 ("vrele: missed vn_close")); 2169 2170 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2171 vp->v_usecount == 1)) { 2172 v_incr_usecount(vp, -1); 2173 VI_UNLOCK(vp); 2174 2175 return; 2176 } 2177 2178 if (vp->v_usecount == 1) { 2179 v_incr_usecount(vp, -1); 2180 /* 2181 * We must call VOP_INACTIVE with the node locked. Mark 2182 * as VI_DOINGINACT to avoid recursion. 2183 */ 2184 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 2185 VI_LOCK(vp); 2186 vp->v_iflag |= VI_DOINGINACT; 2187 VI_UNLOCK(vp); 2188 VOP_INACTIVE(vp, td); 2189 VI_LOCK(vp); 2190 KASSERT(vp->v_iflag & VI_DOINGINACT, 2191 ("vrele: lost VI_DOINGINACT")); 2192 vp->v_iflag &= ~VI_DOINGINACT; 2193 VI_UNLOCK(vp); 2194 } 2195 VI_LOCK(vp); 2196 if (VSHOULDFREE(vp)) 2197 vfree(vp); 2198 else 2199 vlruvp(vp); 2200 VI_UNLOCK(vp); 2201 2202 } else { 2203 #ifdef DIAGNOSTIC 2204 vprint("vrele: negative ref count", vp); 2205 #endif 2206 VI_UNLOCK(vp); 2207 panic("vrele: negative ref cnt"); 2208 } 2209 } 2210 2211 /* 2212 * Release an already locked vnode. This give the same effects as 2213 * unlock+vrele(), but takes less time and avoids releasing and 2214 * re-aquiring the lock (as vrele() aquires the lock internally.) 2215 */ 2216 void 2217 vput(vp) 2218 struct vnode *vp; 2219 { 2220 struct thread *td = curthread; /* XXX */ 2221 2222 GIANT_REQUIRED; 2223 2224 KASSERT(vp != NULL, ("vput: null vp")); 2225 VI_LOCK(vp); 2226 /* Skip this v_writecount check if we're going to panic below. */ 2227 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2228 ("vput: missed vn_close")); 2229 2230 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2231 vp->v_usecount == 1)) { 2232 v_incr_usecount(vp, -1); 2233 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2234 return; 2235 } 2236 2237 if (vp->v_usecount == 1) { 2238 v_incr_usecount(vp, -1); 2239 /* 2240 * We must call VOP_INACTIVE with the node locked, so 2241 * we just need to release the vnode mutex. Mark as 2242 * as VI_DOINGINACT to avoid recursion. 2243 */ 2244 vp->v_iflag |= VI_DOINGINACT; 2245 VI_UNLOCK(vp); 2246 VOP_INACTIVE(vp, td); 2247 VI_LOCK(vp); 2248 KASSERT(vp->v_iflag & VI_DOINGINACT, 2249 ("vput: lost VI_DOINGINACT")); 2250 vp->v_iflag &= ~VI_DOINGINACT; 2251 if (VSHOULDFREE(vp)) 2252 vfree(vp); 2253 else 2254 vlruvp(vp); 2255 VI_UNLOCK(vp); 2256 2257 } else { 2258 #ifdef DIAGNOSTIC 2259 vprint("vput: negative ref count", vp); 2260 #endif 2261 panic("vput: negative ref cnt"); 2262 } 2263 } 2264 2265 /* 2266 * Somebody doesn't want the vnode recycled. 2267 */ 2268 void 2269 vhold(struct vnode *vp) 2270 { 2271 VI_LOCK(vp); 2272 vholdl(vp); 2273 VI_UNLOCK(vp); 2274 } 2275 2276 void 2277 vholdl(vp) 2278 register struct vnode *vp; 2279 { 2280 int s; 2281 2282 s = splbio(); 2283 vp->v_holdcnt++; 2284 if (VSHOULDBUSY(vp)) 2285 vbusy(vp); 2286 splx(s); 2287 } 2288 2289 /* 2290 * Note that there is one less who cares about this vnode. vdrop() is the 2291 * opposite of vhold(). 2292 */ 2293 void 2294 vdrop(struct vnode *vp) 2295 { 2296 VI_LOCK(vp); 2297 vdropl(vp); 2298 VI_UNLOCK(vp); 2299 } 2300 2301 void 2302 vdropl(vp) 2303 register struct vnode *vp; 2304 { 2305 int s; 2306 2307 s = splbio(); 2308 if (vp->v_holdcnt <= 0) 2309 panic("vdrop: holdcnt"); 2310 vp->v_holdcnt--; 2311 if (VSHOULDFREE(vp)) 2312 vfree(vp); 2313 else 2314 vlruvp(vp); 2315 splx(s); 2316 } 2317 2318 /* 2319 * Remove any vnodes in the vnode table belonging to mount point mp. 2320 * 2321 * If FORCECLOSE is not specified, there should not be any active ones, 2322 * return error if any are found (nb: this is a user error, not a 2323 * system error). If FORCECLOSE is specified, detach any active vnodes 2324 * that are found. 2325 * 2326 * If WRITECLOSE is set, only flush out regular file vnodes open for 2327 * writing. 2328 * 2329 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2330 * 2331 * `rootrefs' specifies the base reference count for the root vnode 2332 * of this filesystem. The root vnode is considered busy if its 2333 * v_usecount exceeds this value. On a successful return, vflush() 2334 * will call vrele() on the root vnode exactly rootrefs times. 2335 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2336 * be zero. 2337 */ 2338 #ifdef DIAGNOSTIC 2339 static int busyprt = 0; /* print out busy vnodes */ 2340 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2341 #endif 2342 2343 int 2344 vflush(mp, rootrefs, flags) 2345 struct mount *mp; 2346 int rootrefs; 2347 int flags; 2348 { 2349 struct thread *td = curthread; /* XXX */ 2350 struct vnode *vp, *nvp, *rootvp = NULL; 2351 struct vattr vattr; 2352 int busy = 0, error; 2353 2354 if (rootrefs > 0) { 2355 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2356 ("vflush: bad args")); 2357 /* 2358 * Get the filesystem root vnode. We can vput() it 2359 * immediately, since with rootrefs > 0, it won't go away. 2360 */ 2361 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 2362 return (error); 2363 vput(rootvp); 2364 2365 } 2366 mtx_lock(&mntvnode_mtx); 2367 loop: 2368 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 2369 /* 2370 * Make sure this vnode wasn't reclaimed in getnewvnode(). 2371 * Start over if it has (it won't be on the list anymore). 2372 */ 2373 if (vp->v_mount != mp) 2374 goto loop; 2375 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2376 2377 VI_LOCK(vp); 2378 mtx_unlock(&mntvnode_mtx); 2379 vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY, td); 2380 /* 2381 * Skip over a vnodes marked VV_SYSTEM. 2382 */ 2383 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2384 VOP_UNLOCK(vp, 0, td); 2385 mtx_lock(&mntvnode_mtx); 2386 continue; 2387 } 2388 /* 2389 * If WRITECLOSE is set, flush out unlinked but still open 2390 * files (even if open only for reading) and regular file 2391 * vnodes open for writing. 2392 */ 2393 if (flags & WRITECLOSE) { 2394 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2395 VI_LOCK(vp); 2396 2397 if ((vp->v_type == VNON || 2398 (error == 0 && vattr.va_nlink > 0)) && 2399 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2400 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2401 mtx_lock(&mntvnode_mtx); 2402 continue; 2403 } 2404 } else 2405 VI_LOCK(vp); 2406 2407 VOP_UNLOCK(vp, 0, td); 2408 2409 /* 2410 * With v_usecount == 0, all we need to do is clear out the 2411 * vnode data structures and we are done. 2412 */ 2413 if (vp->v_usecount == 0) { 2414 vgonel(vp, td); 2415 mtx_lock(&mntvnode_mtx); 2416 continue; 2417 } 2418 2419 /* 2420 * If FORCECLOSE is set, forcibly close the vnode. For block 2421 * or character devices, revert to an anonymous device. For 2422 * all other files, just kill them. 2423 */ 2424 if (flags & FORCECLOSE) { 2425 if (vp->v_type != VCHR) { 2426 vgonel(vp, td); 2427 } else { 2428 vclean(vp, 0, td); 2429 VI_UNLOCK(vp); 2430 vp->v_op = spec_vnodeop_p; 2431 insmntque(vp, (struct mount *) 0); 2432 } 2433 mtx_lock(&mntvnode_mtx); 2434 continue; 2435 } 2436 #ifdef DIAGNOSTIC 2437 if (busyprt) 2438 vprint("vflush: busy vnode", vp); 2439 #endif 2440 VI_UNLOCK(vp); 2441 mtx_lock(&mntvnode_mtx); 2442 busy++; 2443 } 2444 mtx_unlock(&mntvnode_mtx); 2445 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2446 /* 2447 * If just the root vnode is busy, and if its refcount 2448 * is equal to `rootrefs', then go ahead and kill it. 2449 */ 2450 VI_LOCK(rootvp); 2451 KASSERT(busy > 0, ("vflush: not busy")); 2452 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 2453 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2454 vgonel(rootvp, td); 2455 busy = 0; 2456 } else 2457 VI_UNLOCK(rootvp); 2458 } 2459 if (busy) 2460 return (EBUSY); 2461 for (; rootrefs > 0; rootrefs--) 2462 vrele(rootvp); 2463 return (0); 2464 } 2465 2466 /* 2467 * This moves a now (likely recyclable) vnode to the end of the 2468 * mountlist. XXX However, it is temporarily disabled until we 2469 * can clean up ffs_sync() and friends, which have loop restart 2470 * conditions which this code causes to operate O(N^2). 2471 */ 2472 static void 2473 vlruvp(struct vnode *vp) 2474 { 2475 #if 0 2476 struct mount *mp; 2477 2478 if ((mp = vp->v_mount) != NULL) { 2479 mtx_lock(&mntvnode_mtx); 2480 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2481 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2482 mtx_unlock(&mntvnode_mtx); 2483 } 2484 #endif 2485 } 2486 2487 /* 2488 * Disassociate the underlying filesystem from a vnode. 2489 */ 2490 static void 2491 vclean(vp, flags, td) 2492 struct vnode *vp; 2493 int flags; 2494 struct thread *td; 2495 { 2496 int active; 2497 2498 ASSERT_VI_LOCKED(vp, "vclean"); 2499 /* 2500 * Check to see if the vnode is in use. If so we have to reference it 2501 * before we clean it out so that its count cannot fall to zero and 2502 * generate a race against ourselves to recycle it. 2503 */ 2504 if ((active = vp->v_usecount)) 2505 v_incr_usecount(vp, 1); 2506 2507 /* 2508 * Prevent the vnode from being recycled or brought into use while we 2509 * clean it out. 2510 */ 2511 if (vp->v_iflag & VI_XLOCK) 2512 panic("vclean: deadlock"); 2513 vp->v_iflag |= VI_XLOCK; 2514 vp->v_vxproc = curthread; 2515 /* 2516 * Even if the count is zero, the VOP_INACTIVE routine may still 2517 * have the object locked while it cleans it out. The VOP_LOCK 2518 * ensures that the VOP_INACTIVE routine is done with its work. 2519 * For active vnodes, it ensures that no other activity can 2520 * occur while the underlying object is being cleaned out. 2521 */ 2522 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2523 2524 /* 2525 * Clean out any buffers associated with the vnode. 2526 * If the flush fails, just toss the buffers. 2527 */ 2528 if (flags & DOCLOSE) { 2529 struct buf *bp; 2530 VI_LOCK(vp); 2531 bp = TAILQ_FIRST(&vp->v_dirtyblkhd); 2532 VI_UNLOCK(vp); 2533 if (bp != NULL) 2534 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2535 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2536 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2537 } 2538 2539 VOP_DESTROYVOBJECT(vp); 2540 2541 /* 2542 * Any other processes trying to obtain this lock must first 2543 * wait for VXLOCK to clear, then call the new lock operation. 2544 */ 2545 VOP_UNLOCK(vp, 0, td); 2546 2547 /* 2548 * If purging an active vnode, it must be closed and 2549 * deactivated before being reclaimed. Note that the 2550 * VOP_INACTIVE will unlock the vnode. 2551 */ 2552 if (active) { 2553 if (flags & DOCLOSE) 2554 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2555 VI_LOCK(vp); 2556 if ((vp->v_iflag & VI_DOINGINACT) == 0) { 2557 vp->v_iflag |= VI_DOINGINACT; 2558 VI_UNLOCK(vp); 2559 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2560 panic("vclean: cannot relock."); 2561 VOP_INACTIVE(vp, td); 2562 VI_LOCK(vp); 2563 KASSERT(vp->v_iflag & VI_DOINGINACT, 2564 ("vclean: lost VI_DOINGINACT")); 2565 vp->v_iflag &= ~VI_DOINGINACT; 2566 } 2567 VI_UNLOCK(vp); 2568 } 2569 2570 /* 2571 * Reclaim the vnode. 2572 */ 2573 if (VOP_RECLAIM(vp, td)) 2574 panic("vclean: cannot reclaim"); 2575 2576 if (active) { 2577 /* 2578 * Inline copy of vrele() since VOP_INACTIVE 2579 * has already been called. 2580 */ 2581 VI_LOCK(vp); 2582 v_incr_usecount(vp, -1); 2583 if (vp->v_usecount <= 0) { 2584 #ifdef DIAGNOSTIC 2585 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2586 vprint("vclean: bad ref count", vp); 2587 panic("vclean: ref cnt"); 2588 } 2589 #endif 2590 vfree(vp); 2591 } 2592 VI_UNLOCK(vp); 2593 } 2594 2595 cache_purge(vp); 2596 VI_LOCK(vp); 2597 if (VSHOULDFREE(vp)) 2598 vfree(vp); 2599 2600 /* 2601 * Done with purge, reset to the standard lock and 2602 * notify sleepers of the grim news. 2603 */ 2604 vp->v_vnlock = &vp->v_lock; 2605 vp->v_op = dead_vnodeop_p; 2606 if (vp->v_pollinfo != NULL) 2607 vn_pollgone(vp); 2608 vp->v_tag = "none"; 2609 vp->v_iflag &= ~VI_XLOCK; 2610 vp->v_vxproc = NULL; 2611 if (vp->v_iflag & VI_XWANT) { 2612 vp->v_iflag &= ~VI_XWANT; 2613 wakeup(vp); 2614 } 2615 } 2616 2617 /* 2618 * Eliminate all activity associated with the requested vnode 2619 * and with all vnodes aliased to the requested vnode. 2620 */ 2621 int 2622 vop_revoke(ap) 2623 struct vop_revoke_args /* { 2624 struct vnode *a_vp; 2625 int a_flags; 2626 } */ *ap; 2627 { 2628 struct vnode *vp, *vq; 2629 dev_t dev; 2630 2631 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2632 vp = ap->a_vp; 2633 KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); 2634 2635 VI_LOCK(vp); 2636 /* 2637 * If a vgone (or vclean) is already in progress, 2638 * wait until it is done and return. 2639 */ 2640 if (vp->v_iflag & VI_XLOCK) { 2641 vp->v_iflag |= VI_XWANT; 2642 msleep(vp, VI_MTX(vp), PINOD | PDROP, 2643 "vop_revokeall", 0); 2644 return (0); 2645 } 2646 VI_UNLOCK(vp); 2647 dev = vp->v_rdev; 2648 for (;;) { 2649 mtx_lock(&spechash_mtx); 2650 vq = SLIST_FIRST(&dev->si_hlist); 2651 mtx_unlock(&spechash_mtx); 2652 if (!vq) 2653 break; 2654 vgone(vq); 2655 } 2656 return (0); 2657 } 2658 2659 /* 2660 * Recycle an unused vnode to the front of the free list. 2661 * Release the passed interlock if the vnode will be recycled. 2662 */ 2663 int 2664 vrecycle(vp, inter_lkp, td) 2665 struct vnode *vp; 2666 struct mtx *inter_lkp; 2667 struct thread *td; 2668 { 2669 2670 VI_LOCK(vp); 2671 if (vp->v_usecount == 0) { 2672 if (inter_lkp) { 2673 mtx_unlock(inter_lkp); 2674 } 2675 vgonel(vp, td); 2676 return (1); 2677 } 2678 VI_UNLOCK(vp); 2679 return (0); 2680 } 2681 2682 /* 2683 * Eliminate all activity associated with a vnode 2684 * in preparation for reuse. 2685 */ 2686 void 2687 vgone(vp) 2688 register struct vnode *vp; 2689 { 2690 struct thread *td = curthread; /* XXX */ 2691 2692 VI_LOCK(vp); 2693 vgonel(vp, td); 2694 } 2695 2696 /* 2697 * vgone, with the vp interlock held. 2698 */ 2699 void 2700 vgonel(vp, td) 2701 struct vnode *vp; 2702 struct thread *td; 2703 { 2704 int s; 2705 2706 /* 2707 * If a vgone (or vclean) is already in progress, 2708 * wait until it is done and return. 2709 */ 2710 ASSERT_VI_LOCKED(vp, "vgonel"); 2711 if (vp->v_iflag & VI_XLOCK) { 2712 vp->v_iflag |= VI_XWANT; 2713 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); 2714 return; 2715 } 2716 2717 /* 2718 * Clean out the filesystem specific data. 2719 */ 2720 vclean(vp, DOCLOSE, td); 2721 VI_UNLOCK(vp); 2722 2723 /* 2724 * Delete from old mount point vnode list, if on one. 2725 */ 2726 if (vp->v_mount != NULL) 2727 insmntque(vp, (struct mount *)0); 2728 /* 2729 * If special device, remove it from special device alias list 2730 * if it is on one. 2731 */ 2732 if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { 2733 VI_LOCK(vp); 2734 mtx_lock(&spechash_mtx); 2735 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2736 vp->v_rdev->si_usecount -= vp->v_usecount; 2737 mtx_unlock(&spechash_mtx); 2738 VI_UNLOCK(vp); 2739 vp->v_rdev = NULL; 2740 } 2741 2742 /* 2743 * If it is on the freelist and not already at the head, 2744 * move it to the head of the list. The test of the 2745 * VDOOMED flag and the reference count of zero is because 2746 * it will be removed from the free list by getnewvnode, 2747 * but will not have its reference count incremented until 2748 * after calling vgone. If the reference count were 2749 * incremented first, vgone would (incorrectly) try to 2750 * close the previous instance of the underlying object. 2751 */ 2752 VI_LOCK(vp); 2753 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2754 s = splbio(); 2755 mtx_lock(&vnode_free_list_mtx); 2756 if (vp->v_iflag & VI_FREE) { 2757 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2758 } else { 2759 vp->v_iflag |= VI_FREE; 2760 freevnodes++; 2761 } 2762 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2763 mtx_unlock(&vnode_free_list_mtx); 2764 splx(s); 2765 } 2766 2767 vp->v_type = VBAD; 2768 VI_UNLOCK(vp); 2769 } 2770 2771 /* 2772 * Lookup a vnode by device number. 2773 */ 2774 int 2775 vfinddev(dev, type, vpp) 2776 dev_t dev; 2777 enum vtype type; 2778 struct vnode **vpp; 2779 { 2780 struct vnode *vp; 2781 2782 mtx_lock(&spechash_mtx); 2783 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2784 if (type == vp->v_type) { 2785 *vpp = vp; 2786 mtx_unlock(&spechash_mtx); 2787 return (1); 2788 } 2789 } 2790 mtx_unlock(&spechash_mtx); 2791 return (0); 2792 } 2793 2794 /* 2795 * Calculate the total number of references to a special device. 2796 */ 2797 int 2798 vcount(vp) 2799 struct vnode *vp; 2800 { 2801 int count; 2802 2803 mtx_lock(&spechash_mtx); 2804 count = vp->v_rdev->si_usecount; 2805 mtx_unlock(&spechash_mtx); 2806 return (count); 2807 } 2808 2809 /* 2810 * Same as above, but using the dev_t as argument 2811 */ 2812 int 2813 count_dev(dev) 2814 dev_t dev; 2815 { 2816 struct vnode *vp; 2817 2818 vp = SLIST_FIRST(&dev->si_hlist); 2819 if (vp == NULL) 2820 return (0); 2821 return(vcount(vp)); 2822 } 2823 2824 /* 2825 * Print out a description of a vnode. 2826 */ 2827 static char *typename[] = 2828 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2829 2830 void 2831 vprint(label, vp) 2832 char *label; 2833 struct vnode *vp; 2834 { 2835 char buf[96]; 2836 2837 if (label != NULL) 2838 printf("%s: %p: ", label, (void *)vp); 2839 else 2840 printf("%p: ", (void *)vp); 2841 printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", 2842 vp->v_tag, typename[vp->v_type], vp->v_usecount, 2843 vp->v_writecount, vp->v_holdcnt); 2844 buf[0] = '\0'; 2845 if (vp->v_vflag & VV_ROOT) 2846 strcat(buf, "|VV_ROOT"); 2847 if (vp->v_vflag & VV_TEXT) 2848 strcat(buf, "|VV_TEXT"); 2849 if (vp->v_vflag & VV_SYSTEM) 2850 strcat(buf, "|VV_SYSTEM"); 2851 if (vp->v_iflag & VI_XLOCK) 2852 strcat(buf, "|VI_XLOCK"); 2853 if (vp->v_iflag & VI_XWANT) 2854 strcat(buf, "|VI_XWANT"); 2855 if (vp->v_iflag & VI_BWAIT) 2856 strcat(buf, "|VI_BWAIT"); 2857 if (vp->v_iflag & VI_DOOMED) 2858 strcat(buf, "|VI_DOOMED"); 2859 if (vp->v_iflag & VI_FREE) 2860 strcat(buf, "|VI_FREE"); 2861 if (vp->v_vflag & VV_OBJBUF) 2862 strcat(buf, "|VV_OBJBUF"); 2863 if (buf[0] != '\0') 2864 printf(" flags (%s),", &buf[1]); 2865 lockmgr_printinfo(vp->v_vnlock); 2866 printf("\n"); 2867 if (vp->v_data != NULL) { 2868 printf("\t"); 2869 VOP_PRINT(vp); 2870 } 2871 } 2872 2873 #ifdef DDB 2874 #include <ddb/ddb.h> 2875 /* 2876 * List all of the locked vnodes in the system. 2877 * Called when debugging the kernel. 2878 */ 2879 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2880 { 2881 struct thread *td = curthread; /* XXX */ 2882 struct mount *mp, *nmp; 2883 struct vnode *vp; 2884 2885 printf("Locked vnodes\n"); 2886 mtx_lock(&mountlist_mtx); 2887 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2888 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 2889 nmp = TAILQ_NEXT(mp, mnt_list); 2890 continue; 2891 } 2892 mtx_lock(&mntvnode_mtx); 2893 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2894 if (VOP_ISLOCKED(vp, NULL)) 2895 vprint((char *)0, vp); 2896 } 2897 mtx_unlock(&mntvnode_mtx); 2898 mtx_lock(&mountlist_mtx); 2899 nmp = TAILQ_NEXT(mp, mnt_list); 2900 vfs_unbusy(mp, td); 2901 } 2902 mtx_unlock(&mountlist_mtx); 2903 } 2904 #endif 2905 2906 /* 2907 * Fill in a struct xvfsconf based on a struct vfsconf. 2908 */ 2909 static void 2910 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2911 { 2912 2913 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2914 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2915 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2916 xvfsp->vfc_flags = vfsp->vfc_flags; 2917 /* 2918 * These are unused in userland, we keep them 2919 * to not break binary compatibility. 2920 */ 2921 xvfsp->vfc_vfsops = NULL; 2922 xvfsp->vfc_next = NULL; 2923 } 2924 2925 static int 2926 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2927 { 2928 struct vfsconf *vfsp; 2929 struct xvfsconf *xvfsp; 2930 int cnt, error, i; 2931 2932 cnt = 0; 2933 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 2934 cnt++; 2935 xvfsp = malloc(sizeof(struct xvfsconf) * cnt, M_TEMP, M_WAITOK); 2936 /* 2937 * Handle the race that we will have here when struct vfsconf 2938 * will be locked down by using both cnt and checking vfc_next 2939 * against NULL to determine the end of the loop. The race will 2940 * happen because we will have to unlock before calling malloc(). 2941 * We are protected by Giant for now. 2942 */ 2943 i = 0; 2944 for (vfsp = vfsconf; vfsp != NULL && i < cnt; vfsp = vfsp->vfc_next) { 2945 vfsconf2x(vfsp, xvfsp + i); 2946 i++; 2947 } 2948 error = SYSCTL_OUT(req, xvfsp, sizeof(struct xvfsconf) * i); 2949 free(xvfsp, M_TEMP); 2950 return (error); 2951 } 2952 2953 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2954 "S,xvfsconf", "List of all configured filesystems"); 2955 2956 /* 2957 * Top level filesystem related information gathering. 2958 */ 2959 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2960 2961 static int 2962 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2963 { 2964 int *name = (int *)arg1 - 1; /* XXX */ 2965 u_int namelen = arg2 + 1; /* XXX */ 2966 struct vfsconf *vfsp; 2967 struct xvfsconf xvfsp; 2968 2969 printf("WARNING: userland calling deprecated sysctl, " 2970 "please rebuild world\n"); 2971 2972 #if 1 || defined(COMPAT_PRELITE2) 2973 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2974 if (namelen == 1) 2975 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2976 #endif 2977 2978 switch (name[1]) { 2979 case VFS_MAXTYPENUM: 2980 if (namelen != 2) 2981 return (ENOTDIR); 2982 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2983 case VFS_CONF: 2984 if (namelen != 3) 2985 return (ENOTDIR); /* overloaded */ 2986 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2987 if (vfsp->vfc_typenum == name[2]) 2988 break; 2989 if (vfsp == NULL) 2990 return (EOPNOTSUPP); 2991 vfsconf2x(vfsp, &xvfsp); 2992 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2993 } 2994 return (EOPNOTSUPP); 2995 } 2996 2997 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 2998 "Generic filesystem"); 2999 3000 #if 1 || defined(COMPAT_PRELITE2) 3001 3002 static int 3003 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3004 { 3005 int error; 3006 struct vfsconf *vfsp; 3007 struct ovfsconf ovfs; 3008 3009 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 3010 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3011 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3012 ovfs.vfc_index = vfsp->vfc_typenum; 3013 ovfs.vfc_refcount = vfsp->vfc_refcount; 3014 ovfs.vfc_flags = vfsp->vfc_flags; 3015 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3016 if (error) 3017 return error; 3018 } 3019 return 0; 3020 } 3021 3022 #endif /* 1 || COMPAT_PRELITE2 */ 3023 3024 #define KINFO_VNODESLOP 10 3025 #ifdef notyet 3026 /* 3027 * Dump vnode list (via sysctl). 3028 */ 3029 /* ARGSUSED */ 3030 static int 3031 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3032 { 3033 struct xvnode *xvn; 3034 struct thread *td = req->td; 3035 struct mount *mp; 3036 struct vnode *vp; 3037 int error, len, n; 3038 3039 /* 3040 * Stale numvnodes access is not fatal here. 3041 */ 3042 req->lock = 0; 3043 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3044 if (!req->oldptr) 3045 /* Make an estimate */ 3046 return (SYSCTL_OUT(req, 0, len)); 3047 3048 sysctl_wire_old_buffer(req, 0); 3049 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3050 n = 0; 3051 mtx_lock(&mountlist_mtx); 3052 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3053 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 3054 continue; 3055 mtx_lock(&mntvnode_mtx); 3056 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3057 if (n == len) 3058 break; 3059 vref(vp); 3060 xvn[n].xv_size = sizeof *xvn; 3061 xvn[n].xv_vnode = vp; 3062 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3063 XV_COPY(usecount); 3064 XV_COPY(writecount); 3065 XV_COPY(holdcnt); 3066 XV_COPY(id); 3067 XV_COPY(mount); 3068 XV_COPY(numoutput); 3069 XV_COPY(type); 3070 #undef XV_COPY 3071 xvn[n].xv_flag = vp->v_vflag; 3072 3073 switch (vp->v_type) { 3074 case VREG: 3075 case VDIR: 3076 case VLNK: 3077 xvn[n].xv_dev = vp->v_cachedfs; 3078 xvn[n].xv_ino = vp->v_cachedid; 3079 break; 3080 case VBLK: 3081 case VCHR: 3082 if (vp->v_rdev == NULL) { 3083 vrele(vp); 3084 continue; 3085 } 3086 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3087 break; 3088 case VSOCK: 3089 xvn[n].xv_socket = vp->v_socket; 3090 break; 3091 case VFIFO: 3092 xvn[n].xv_fifo = vp->v_fifoinfo; 3093 break; 3094 case VNON: 3095 case VBAD: 3096 default: 3097 /* shouldn't happen? */ 3098 vrele(vp); 3099 continue; 3100 } 3101 vrele(vp); 3102 ++n; 3103 } 3104 mtx_unlock(&mntvnode_mtx); 3105 mtx_lock(&mountlist_mtx); 3106 vfs_unbusy(mp, td); 3107 if (n == len) 3108 break; 3109 } 3110 mtx_unlock(&mountlist_mtx); 3111 3112 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3113 free(xvn, M_TEMP); 3114 return (error); 3115 } 3116 3117 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 3118 0, 0, sysctl_vnode, "S,xvnode", ""); 3119 #endif 3120 3121 /* 3122 * Check to see if a filesystem is mounted on a block device. 3123 */ 3124 int 3125 vfs_mountedon(vp) 3126 struct vnode *vp; 3127 { 3128 3129 if (vp->v_rdev->si_mountpoint != NULL) 3130 return (EBUSY); 3131 return (0); 3132 } 3133 3134 /* 3135 * Unmount all filesystems. The list is traversed in reverse order 3136 * of mounting to avoid dependencies. 3137 */ 3138 void 3139 vfs_unmountall() 3140 { 3141 struct mount *mp; 3142 struct thread *td; 3143 int error; 3144 3145 if (curthread != NULL) 3146 td = curthread; 3147 else 3148 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 3149 /* 3150 * Since this only runs when rebooting, it is not interlocked. 3151 */ 3152 while(!TAILQ_EMPTY(&mountlist)) { 3153 mp = TAILQ_LAST(&mountlist, mntlist); 3154 error = dounmount(mp, MNT_FORCE, td); 3155 if (error) { 3156 TAILQ_REMOVE(&mountlist, mp, mnt_list); 3157 printf("unmount of %s failed (", 3158 mp->mnt_stat.f_mntonname); 3159 if (error == EBUSY) 3160 printf("BUSY)\n"); 3161 else 3162 printf("%d)\n", error); 3163 } else { 3164 /* The unmount has removed mp from the mountlist */ 3165 } 3166 } 3167 } 3168 3169 /* 3170 * perform msync on all vnodes under a mount point 3171 * the mount point must be locked. 3172 */ 3173 void 3174 vfs_msync(struct mount *mp, int flags) 3175 { 3176 struct vnode *vp, *nvp; 3177 struct vm_object *obj; 3178 int tries; 3179 3180 GIANT_REQUIRED; 3181 3182 tries = 5; 3183 mtx_lock(&mntvnode_mtx); 3184 loop: 3185 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 3186 if (vp->v_mount != mp) { 3187 if (--tries > 0) 3188 goto loop; 3189 break; 3190 } 3191 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 3192 3193 VI_LOCK(vp); 3194 if (vp->v_iflag & VI_XLOCK) { /* XXX: what if MNT_WAIT? */ 3195 VI_UNLOCK(vp); 3196 continue; 3197 } 3198 3199 if ((vp->v_iflag & VI_OBJDIRTY) && 3200 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 3201 mtx_unlock(&mntvnode_mtx); 3202 if (!vget(vp, 3203 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3204 curthread)) { 3205 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3206 vput(vp); 3207 mtx_lock(&mntvnode_mtx); 3208 continue; 3209 } 3210 3211 if (VOP_GETVOBJECT(vp, &obj) == 0) { 3212 vm_object_page_clean(obj, 0, 0, 3213 flags == MNT_WAIT ? 3214 OBJPC_SYNC : OBJPC_NOSYNC); 3215 } 3216 vput(vp); 3217 } 3218 mtx_lock(&mntvnode_mtx); 3219 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3220 if (--tries > 0) 3221 goto loop; 3222 break; 3223 } 3224 } else 3225 VI_UNLOCK(vp); 3226 } 3227 mtx_unlock(&mntvnode_mtx); 3228 } 3229 3230 /* 3231 * Create the VM object needed for VMIO and mmap support. This 3232 * is done for all VREG files in the system. Some filesystems might 3233 * afford the additional metadata buffering capability of the 3234 * VMIO code by making the device node be VMIO mode also. 3235 * 3236 * vp must be locked when vfs_object_create is called. 3237 */ 3238 int 3239 vfs_object_create(vp, td, cred) 3240 struct vnode *vp; 3241 struct thread *td; 3242 struct ucred *cred; 3243 { 3244 GIANT_REQUIRED; 3245 return (VOP_CREATEVOBJECT(vp, cred, td)); 3246 } 3247 3248 /* 3249 * Mark a vnode as free, putting it up for recycling. 3250 */ 3251 void 3252 vfree(vp) 3253 struct vnode *vp; 3254 { 3255 int s; 3256 3257 ASSERT_VI_LOCKED(vp, "vfree"); 3258 s = splbio(); 3259 mtx_lock(&vnode_free_list_mtx); 3260 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3261 if (vp->v_iflag & VI_AGE) { 3262 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3263 } else { 3264 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3265 } 3266 freevnodes++; 3267 mtx_unlock(&vnode_free_list_mtx); 3268 vp->v_iflag &= ~VI_AGE; 3269 vp->v_iflag |= VI_FREE; 3270 splx(s); 3271 } 3272 3273 /* 3274 * Opposite of vfree() - mark a vnode as in use. 3275 */ 3276 void 3277 vbusy(vp) 3278 struct vnode *vp; 3279 { 3280 int s; 3281 3282 s = splbio(); 3283 ASSERT_VI_LOCKED(vp, "vbusy"); 3284 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3285 3286 mtx_lock(&vnode_free_list_mtx); 3287 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3288 freevnodes--; 3289 mtx_unlock(&vnode_free_list_mtx); 3290 3291 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3292 splx(s); 3293 } 3294 3295 /* 3296 * Record a process's interest in events which might happen to 3297 * a vnode. Because poll uses the historic select-style interface 3298 * internally, this routine serves as both the ``check for any 3299 * pending events'' and the ``record my interest in future events'' 3300 * functions. (These are done together, while the lock is held, 3301 * to avoid race conditions.) 3302 */ 3303 int 3304 vn_pollrecord(vp, td, events) 3305 struct vnode *vp; 3306 struct thread *td; 3307 short events; 3308 { 3309 3310 if (vp->v_pollinfo == NULL) 3311 v_addpollinfo(vp); 3312 mtx_lock(&vp->v_pollinfo->vpi_lock); 3313 if (vp->v_pollinfo->vpi_revents & events) { 3314 /* 3315 * This leaves events we are not interested 3316 * in available for the other process which 3317 * which presumably had requested them 3318 * (otherwise they would never have been 3319 * recorded). 3320 */ 3321 events &= vp->v_pollinfo->vpi_revents; 3322 vp->v_pollinfo->vpi_revents &= ~events; 3323 3324 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3325 return events; 3326 } 3327 vp->v_pollinfo->vpi_events |= events; 3328 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3329 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3330 return 0; 3331 } 3332 3333 /* 3334 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3335 * it is possible for us to miss an event due to race conditions, but 3336 * that condition is expected to be rare, so for the moment it is the 3337 * preferred interface. 3338 */ 3339 void 3340 vn_pollevent(vp, events) 3341 struct vnode *vp; 3342 short events; 3343 { 3344 3345 if (vp->v_pollinfo == NULL) 3346 v_addpollinfo(vp); 3347 mtx_lock(&vp->v_pollinfo->vpi_lock); 3348 if (vp->v_pollinfo->vpi_events & events) { 3349 /* 3350 * We clear vpi_events so that we don't 3351 * call selwakeup() twice if two events are 3352 * posted before the polling process(es) is 3353 * awakened. This also ensures that we take at 3354 * most one selwakeup() if the polling process 3355 * is no longer interested. However, it does 3356 * mean that only one event can be noticed at 3357 * a time. (Perhaps we should only clear those 3358 * event bits which we note?) XXX 3359 */ 3360 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3361 vp->v_pollinfo->vpi_revents |= events; 3362 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3363 } 3364 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3365 } 3366 3367 /* 3368 * Wake up anyone polling on vp because it is being revoked. 3369 * This depends on dead_poll() returning POLLHUP for correct 3370 * behavior. 3371 */ 3372 void 3373 vn_pollgone(vp) 3374 struct vnode *vp; 3375 { 3376 3377 mtx_lock(&vp->v_pollinfo->vpi_lock); 3378 VN_KNOTE(vp, NOTE_REVOKE); 3379 if (vp->v_pollinfo->vpi_events) { 3380 vp->v_pollinfo->vpi_events = 0; 3381 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3382 } 3383 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3384 } 3385 3386 3387 3388 /* 3389 * Routine to create and manage a filesystem syncer vnode. 3390 */ 3391 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3392 static int sync_fsync(struct vop_fsync_args *); 3393 static int sync_inactive(struct vop_inactive_args *); 3394 static int sync_reclaim(struct vop_reclaim_args *); 3395 static int sync_print(struct vop_print_args *); 3396 3397 static vop_t **sync_vnodeop_p; 3398 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3399 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3400 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3401 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3402 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3403 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3404 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3405 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3406 { &vop_print_desc, (vop_t *) sync_print }, /* print */ 3407 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3408 { NULL, NULL } 3409 }; 3410 static struct vnodeopv_desc sync_vnodeop_opv_desc = 3411 { &sync_vnodeop_p, sync_vnodeop_entries }; 3412 3413 VNODEOP_SET(sync_vnodeop_opv_desc); 3414 3415 /* 3416 * Create a new filesystem syncer vnode for the specified mount point. 3417 */ 3418 int 3419 vfs_allocate_syncvnode(mp) 3420 struct mount *mp; 3421 { 3422 struct vnode *vp; 3423 static long start, incr, next; 3424 int error; 3425 3426 /* Allocate a new vnode */ 3427 if ((error = getnewvnode("vfs", mp, sync_vnodeop_p, &vp)) != 0) { 3428 mp->mnt_syncer = NULL; 3429 return (error); 3430 } 3431 vp->v_type = VNON; 3432 /* 3433 * Place the vnode onto the syncer worklist. We attempt to 3434 * scatter them about on the list so that they will go off 3435 * at evenly distributed times even if all the filesystems 3436 * are mounted at once. 3437 */ 3438 next += incr; 3439 if (next == 0 || next > syncer_maxdelay) { 3440 start /= 2; 3441 incr /= 2; 3442 if (start == 0) { 3443 start = syncer_maxdelay / 2; 3444 incr = syncer_maxdelay; 3445 } 3446 next = start; 3447 } 3448 VI_LOCK(vp); 3449 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 3450 VI_UNLOCK(vp); 3451 mp->mnt_syncer = vp; 3452 return (0); 3453 } 3454 3455 /* 3456 * Do a lazy sync of the filesystem. 3457 */ 3458 static int 3459 sync_fsync(ap) 3460 struct vop_fsync_args /* { 3461 struct vnode *a_vp; 3462 struct ucred *a_cred; 3463 int a_waitfor; 3464 struct thread *a_td; 3465 } */ *ap; 3466 { 3467 struct vnode *syncvp = ap->a_vp; 3468 struct mount *mp = syncvp->v_mount; 3469 struct thread *td = ap->a_td; 3470 int error, asyncflag; 3471 3472 /* 3473 * We only need to do something if this is a lazy evaluation. 3474 */ 3475 if (ap->a_waitfor != MNT_LAZY) 3476 return (0); 3477 3478 /* 3479 * Move ourselves to the back of the sync list. 3480 */ 3481 VI_LOCK(syncvp); 3482 vn_syncer_add_to_worklist(syncvp, syncdelay); 3483 VI_UNLOCK(syncvp); 3484 3485 /* 3486 * Walk the list of vnodes pushing all that are dirty and 3487 * not already on the sync list. 3488 */ 3489 mtx_lock(&mountlist_mtx); 3490 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3491 mtx_unlock(&mountlist_mtx); 3492 return (0); 3493 } 3494 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3495 vfs_unbusy(mp, td); 3496 return (0); 3497 } 3498 asyncflag = mp->mnt_flag & MNT_ASYNC; 3499 mp->mnt_flag &= ~MNT_ASYNC; 3500 vfs_msync(mp, MNT_NOWAIT); 3501 error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3502 if (asyncflag) 3503 mp->mnt_flag |= MNT_ASYNC; 3504 vn_finished_write(mp); 3505 vfs_unbusy(mp, td); 3506 return (error); 3507 } 3508 3509 /* 3510 * The syncer vnode is no referenced. 3511 */ 3512 static int 3513 sync_inactive(ap) 3514 struct vop_inactive_args /* { 3515 struct vnode *a_vp; 3516 struct thread *a_td; 3517 } */ *ap; 3518 { 3519 3520 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3521 vgone(ap->a_vp); 3522 return (0); 3523 } 3524 3525 /* 3526 * The syncer vnode is no longer needed and is being decommissioned. 3527 * 3528 * Modifications to the worklist must be protected at splbio(). 3529 */ 3530 static int 3531 sync_reclaim(ap) 3532 struct vop_reclaim_args /* { 3533 struct vnode *a_vp; 3534 } */ *ap; 3535 { 3536 struct vnode *vp = ap->a_vp; 3537 int s; 3538 3539 s = splbio(); 3540 vp->v_mount->mnt_syncer = NULL; 3541 VI_LOCK(vp); 3542 if (vp->v_iflag & VI_ONWORKLST) { 3543 mtx_lock(&sync_mtx); 3544 LIST_REMOVE(vp, v_synclist); 3545 mtx_unlock(&sync_mtx); 3546 vp->v_iflag &= ~VI_ONWORKLST; 3547 } 3548 VI_UNLOCK(vp); 3549 splx(s); 3550 3551 return (0); 3552 } 3553 3554 /* 3555 * Print out a syncer vnode. 3556 */ 3557 static int 3558 sync_print(ap) 3559 struct vop_print_args /* { 3560 struct vnode *a_vp; 3561 } */ *ap; 3562 { 3563 struct vnode *vp = ap->a_vp; 3564 3565 printf("syncer vnode"); 3566 if (vp->v_vnlock != NULL) 3567 lockmgr_printinfo(vp->v_vnlock); 3568 printf("\n"); 3569 return (0); 3570 } 3571 3572 /* 3573 * extract the dev_t from a VCHR 3574 */ 3575 dev_t 3576 vn_todev(vp) 3577 struct vnode *vp; 3578 { 3579 if (vp->v_type != VCHR) 3580 return (NODEV); 3581 return (vp->v_rdev); 3582 } 3583 3584 /* 3585 * Check if vnode represents a disk device 3586 */ 3587 int 3588 vn_isdisk(vp, errp) 3589 struct vnode *vp; 3590 int *errp; 3591 { 3592 struct cdevsw *cdevsw; 3593 3594 if (vp->v_type != VCHR) { 3595 if (errp != NULL) 3596 *errp = ENOTBLK; 3597 return (0); 3598 } 3599 if (vp->v_rdev == NULL) { 3600 if (errp != NULL) 3601 *errp = ENXIO; 3602 return (0); 3603 } 3604 cdevsw = devsw(vp->v_rdev); 3605 if (cdevsw == NULL) { 3606 if (errp != NULL) 3607 *errp = ENXIO; 3608 return (0); 3609 } 3610 if (!(cdevsw->d_flags & D_DISK)) { 3611 if (errp != NULL) 3612 *errp = ENOTBLK; 3613 return (0); 3614 } 3615 if (errp != NULL) 3616 *errp = 0; 3617 return (1); 3618 } 3619 3620 /* 3621 * Free data allocated by namei(); see namei(9) for details. 3622 */ 3623 void 3624 NDFREE(ndp, flags) 3625 struct nameidata *ndp; 3626 const uint flags; 3627 { 3628 if (!(flags & NDF_NO_FREE_PNBUF) && 3629 (ndp->ni_cnd.cn_flags & HASBUF)) { 3630 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3631 ndp->ni_cnd.cn_flags &= ~HASBUF; 3632 } 3633 if (!(flags & NDF_NO_DVP_UNLOCK) && 3634 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3635 ndp->ni_dvp != ndp->ni_vp) 3636 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3637 if (!(flags & NDF_NO_DVP_RELE) && 3638 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3639 vrele(ndp->ni_dvp); 3640 ndp->ni_dvp = NULL; 3641 } 3642 if (!(flags & NDF_NO_VP_UNLOCK) && 3643 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3644 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3645 if (!(flags & NDF_NO_VP_RELE) && 3646 ndp->ni_vp) { 3647 vrele(ndp->ni_vp); 3648 ndp->ni_vp = NULL; 3649 } 3650 if (!(flags & NDF_NO_STARTDIR_RELE) && 3651 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3652 vrele(ndp->ni_startdir); 3653 ndp->ni_startdir = NULL; 3654 } 3655 } 3656 3657 /* 3658 * Common filesystem object access control check routine. Accepts a 3659 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3660 * and optional call-by-reference privused argument allowing vaccess() 3661 * to indicate to the caller whether privilege was used to satisfy the 3662 * request (obsoleted). Returns 0 on success, or an errno on failure. 3663 */ 3664 int 3665 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3666 enum vtype type; 3667 mode_t file_mode; 3668 uid_t file_uid; 3669 gid_t file_gid; 3670 mode_t acc_mode; 3671 struct ucred *cred; 3672 int *privused; 3673 { 3674 mode_t dac_granted; 3675 #ifdef CAPABILITIES 3676 mode_t cap_granted; 3677 #endif 3678 3679 /* 3680 * Look for a normal, non-privileged way to access the file/directory 3681 * as requested. If it exists, go with that. 3682 */ 3683 3684 if (privused != NULL) 3685 *privused = 0; 3686 3687 dac_granted = 0; 3688 3689 /* Check the owner. */ 3690 if (cred->cr_uid == file_uid) { 3691 dac_granted |= VADMIN; 3692 if (file_mode & S_IXUSR) 3693 dac_granted |= VEXEC; 3694 if (file_mode & S_IRUSR) 3695 dac_granted |= VREAD; 3696 if (file_mode & S_IWUSR) 3697 dac_granted |= (VWRITE | VAPPEND); 3698 3699 if ((acc_mode & dac_granted) == acc_mode) 3700 return (0); 3701 3702 goto privcheck; 3703 } 3704 3705 /* Otherwise, check the groups (first match) */ 3706 if (groupmember(file_gid, cred)) { 3707 if (file_mode & S_IXGRP) 3708 dac_granted |= VEXEC; 3709 if (file_mode & S_IRGRP) 3710 dac_granted |= VREAD; 3711 if (file_mode & S_IWGRP) 3712 dac_granted |= (VWRITE | VAPPEND); 3713 3714 if ((acc_mode & dac_granted) == acc_mode) 3715 return (0); 3716 3717 goto privcheck; 3718 } 3719 3720 /* Otherwise, check everyone else. */ 3721 if (file_mode & S_IXOTH) 3722 dac_granted |= VEXEC; 3723 if (file_mode & S_IROTH) 3724 dac_granted |= VREAD; 3725 if (file_mode & S_IWOTH) 3726 dac_granted |= (VWRITE | VAPPEND); 3727 if ((acc_mode & dac_granted) == acc_mode) 3728 return (0); 3729 3730 privcheck: 3731 if (!suser_cred(cred, PRISON_ROOT)) { 3732 /* XXX audit: privilege used */ 3733 if (privused != NULL) 3734 *privused = 1; 3735 return (0); 3736 } 3737 3738 #ifdef CAPABILITIES 3739 /* 3740 * Build a capability mask to determine if the set of capabilities 3741 * satisfies the requirements when combined with the granted mask 3742 * from above. 3743 * For each capability, if the capability is required, bitwise 3744 * or the request type onto the cap_granted mask. 3745 */ 3746 cap_granted = 0; 3747 3748 if (type == VDIR) { 3749 /* 3750 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3751 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3752 */ 3753 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3754 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3755 cap_granted |= VEXEC; 3756 } else { 3757 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3758 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3759 cap_granted |= VEXEC; 3760 } 3761 3762 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3763 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3764 cap_granted |= VREAD; 3765 3766 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3767 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3768 cap_granted |= (VWRITE | VAPPEND); 3769 3770 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3771 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3772 cap_granted |= VADMIN; 3773 3774 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3775 /* XXX audit: privilege used */ 3776 if (privused != NULL) 3777 *privused = 1; 3778 return (0); 3779 } 3780 #endif 3781 3782 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3783 } 3784 3785 /* 3786 * Credential check based on process requesting service, and per-attribute 3787 * permissions. 3788 */ 3789 int 3790 extattr_check_cred(struct vnode *vp, int attrnamespace, 3791 struct ucred *cred, struct thread *td, int access) 3792 { 3793 3794 /* 3795 * Kernel-invoked always succeeds. 3796 */ 3797 if (cred == NOCRED) 3798 return (0); 3799 3800 /* 3801 * Do not allow privileged processes in jail to directly 3802 * manipulate system attributes. 3803 * 3804 * XXX What capability should apply here? 3805 * Probably CAP_SYS_SETFFLAG. 3806 */ 3807 switch (attrnamespace) { 3808 case EXTATTR_NAMESPACE_SYSTEM: 3809 /* Potentially should be: return (EPERM); */ 3810 return (suser_cred(cred, 0)); 3811 case EXTATTR_NAMESPACE_USER: 3812 return (VOP_ACCESS(vp, access, cred, td)); 3813 default: 3814 return (EPERM); 3815 } 3816 } 3817