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 */ 40 41 /* 42 * External virtual filesystem routines 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include "opt_ddb.h" 49 #include "opt_mac.h" 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/bio.h> 54 #include <sys/buf.h> 55 #include <sys/conf.h> 56 #include <sys/eventhandler.h> 57 #include <sys/extattr.h> 58 #include <sys/fcntl.h> 59 #include <sys/kernel.h> 60 #include <sys/kthread.h> 61 #include <sys/mac.h> 62 #include <sys/malloc.h> 63 #include <sys/mount.h> 64 #include <sys/namei.h> 65 #include <sys/stat.h> 66 #include <sys/sysctl.h> 67 #include <sys/syslog.h> 68 #include <sys/vmmeter.h> 69 #include <sys/vnode.h> 70 71 #include <vm/vm.h> 72 #include <vm/vm_object.h> 73 #include <vm/vm_extern.h> 74 #include <vm/pmap.h> 75 #include <vm/vm_map.h> 76 #include <vm/vm_page.h> 77 #include <vm/vm_kern.h> 78 #include <vm/uma.h> 79 80 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 81 82 static void addalias(struct vnode *vp, dev_t nvp_rdev); 83 static void insmntque(struct vnode *vp, struct mount *mp); 84 static void vclean(struct vnode *vp, int flags, struct thread *td); 85 static void vlruvp(struct vnode *vp); 86 static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, 87 int slpflag, int slptimeo, int *errorp); 88 static int vcanrecycle(struct vnode *vp, struct mount **vnmpp); 89 90 91 /* 92 * Number of vnodes in existence. Increased whenever getnewvnode() 93 * allocates a new vnode, never decreased. 94 */ 95 static unsigned long numvnodes; 96 97 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 98 99 /* 100 * Conversion tables for conversion from vnode types to inode formats 101 * and back. 102 */ 103 enum vtype iftovt_tab[16] = { 104 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 105 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 106 }; 107 int vttoif_tab[9] = { 108 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 109 S_IFSOCK, S_IFIFO, S_IFMT, 110 }; 111 112 /* 113 * List of vnodes that are ready for recycling. 114 */ 115 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 116 117 /* 118 * Minimum number of free vnodes. If there are fewer than this free vnodes, 119 * getnewvnode() will return a newly allocated vnode. 120 */ 121 static u_long wantfreevnodes = 25; 122 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 123 /* Number of vnodes in the free list. */ 124 static u_long freevnodes; 125 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 126 127 /* 128 * Various variables used for debugging the new implementation of 129 * reassignbuf(). 130 * XXX these are probably of (very) limited utility now. 131 */ 132 static int reassignbufcalls; 133 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 134 static int nameileafonly; 135 SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 136 137 /* 138 * Cache for the mount type id assigned to NFS. This is used for 139 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 140 */ 141 int nfs_mount_type = -1; 142 143 /* To keep more than one thread at a time from running vfs_getnewfsid */ 144 static struct mtx mntid_mtx; 145 146 /* 147 * Lock for any access to the following: 148 * vnode_free_list 149 * numvnodes 150 * freevnodes 151 */ 152 static struct mtx vnode_free_list_mtx; 153 154 /* 155 * For any iteration/modification of dev->si_hlist (linked through 156 * v_specnext) 157 */ 158 static struct mtx spechash_mtx; 159 160 /* Publicly exported FS */ 161 struct nfs_public nfs_pub; 162 163 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 164 static uma_zone_t vnode_zone; 165 static uma_zone_t vnodepoll_zone; 166 167 /* Set to 1 to print out reclaim of active vnodes */ 168 int prtactive; 169 170 /* 171 * The workitem queue. 172 * 173 * It is useful to delay writes of file data and filesystem metadata 174 * for tens of seconds so that quickly created and deleted files need 175 * not waste disk bandwidth being created and removed. To realize this, 176 * we append vnodes to a "workitem" queue. When running with a soft 177 * updates implementation, most pending metadata dependencies should 178 * not wait for more than a few seconds. Thus, mounted on block devices 179 * are delayed only about a half the time that file data is delayed. 180 * Similarly, directory updates are more critical, so are only delayed 181 * about a third the time that file data is delayed. Thus, there are 182 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 183 * one each second (driven off the filesystem syncer process). The 184 * syncer_delayno variable indicates the next queue that is to be processed. 185 * Items that need to be processed soon are placed in this queue: 186 * 187 * syncer_workitem_pending[syncer_delayno] 188 * 189 * A delay of fifteen seconds is done by placing the request fifteen 190 * entries later in the queue: 191 * 192 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 193 * 194 */ 195 static int syncer_delayno; 196 static long syncer_mask; 197 LIST_HEAD(synclist, vnode); 198 static struct synclist *syncer_workitem_pending; 199 /* 200 * The sync_mtx protects: 201 * vp->v_synclist 202 * syncer_delayno 203 * syncer_workitem_pending 204 * rushjob 205 */ 206 static struct mtx sync_mtx; 207 208 #define SYNCER_MAXDELAY 32 209 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 210 static int syncdelay = 30; /* max time to delay syncing data */ 211 static int filedelay = 30; /* time to delay syncing files */ 212 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 213 static int dirdelay = 29; /* time to delay syncing directories */ 214 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 215 static int metadelay = 28; /* time to delay syncing metadata */ 216 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 217 static int rushjob; /* number of slots to run ASAP */ 218 static int stat_rush_requests; /* number of times I/O speeded up */ 219 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 220 221 /* 222 * Number of vnodes we want to exist at any one time. This is mostly used 223 * to size hash tables in vnode-related code. It is normally not used in 224 * getnewvnode(), as wantfreevnodes is normally nonzero.) 225 * 226 * XXX desiredvnodes is historical cruft and should not exist. 227 */ 228 int desiredvnodes; 229 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 230 &desiredvnodes, 0, "Maximum number of vnodes"); 231 static int minvnodes; 232 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 233 &minvnodes, 0, "Minimum number of vnodes"); 234 static int vnlru_nowhere; 235 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0, 236 "Number of times the vnlru process ran without success"); 237 238 /* Hook for calling soft updates */ 239 int (*softdep_process_worklist_hook)(struct mount *); 240 241 /* 242 * This only exists to supress warnings from unlocked specfs accesses. It is 243 * no longer ok to have an unlocked VFS. 244 */ 245 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 246 247 /* Print lock violations */ 248 int vfs_badlock_print = 1; 249 250 /* Panic on violation */ 251 int vfs_badlock_panic = 1; 252 253 /* Check for interlock across VOPs */ 254 int vfs_badlock_mutex = 1; 255 256 static void 257 vfs_badlock(char *msg, char *str, struct vnode *vp) 258 { 259 if (vfs_badlock_print) 260 printf("%s: %p %s\n", str, vp, msg); 261 if (vfs_badlock_panic) 262 Debugger("Lock violation.\n"); 263 } 264 265 void 266 assert_vi_unlocked(struct vnode *vp, char *str) 267 { 268 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 269 vfs_badlock("interlock is locked but should not be", str, vp); 270 } 271 272 void 273 assert_vi_locked(struct vnode *vp, char *str) 274 { 275 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 276 vfs_badlock("interlock is not locked but should be", str, vp); 277 } 278 279 void 280 assert_vop_locked(struct vnode *vp, char *str) 281 { 282 if (vp && !IGNORE_LOCK(vp) && !VOP_ISLOCKED(vp, NULL)) 283 vfs_badlock("is not locked but should be", str, vp); 284 } 285 286 void 287 assert_vop_unlocked(struct vnode *vp, char *str) 288 { 289 if (vp && !IGNORE_LOCK(vp) && 290 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 291 vfs_badlock("is locked but should not be", str, vp); 292 } 293 294 void 295 assert_vop_elocked(struct vnode *vp, char *str) 296 { 297 if (vp && !IGNORE_LOCK(vp) && 298 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 299 vfs_badlock("is not exclusive locked but should be", str, vp); 300 } 301 302 void 303 assert_vop_elocked_other(struct vnode *vp, char *str) 304 { 305 if (vp && !IGNORE_LOCK(vp) && 306 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 307 vfs_badlock("is not exclusive locked by another thread", 308 str, vp); 309 } 310 311 void 312 assert_vop_slocked(struct vnode *vp, char *str) 313 { 314 if (vp && !IGNORE_LOCK(vp) && 315 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 316 vfs_badlock("is not locked shared but should be", str, vp); 317 } 318 319 void 320 vop_rename_pre(void *ap) 321 { 322 struct vop_rename_args *a = ap; 323 324 if (a->a_tvp) 325 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 326 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 327 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 328 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 329 330 /* Check the source (from) */ 331 if (a->a_tdvp != a->a_fdvp) 332 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked.\n"); 333 if (a->a_tvp != a->a_fvp) 334 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked.\n"); 335 336 /* Check the target */ 337 if (a->a_tvp) 338 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked.\n"); 339 340 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked.\n"); 341 } 342 343 void 344 vop_strategy_pre(void *ap) 345 { 346 struct vop_strategy_args *a = ap; 347 struct buf *bp; 348 349 bp = a->a_bp; 350 351 /* 352 * Cluster ops lock their component buffers but not the IO container. 353 */ 354 if ((bp->b_flags & B_CLUSTER) != 0) 355 return; 356 357 if (BUF_REFCNT(bp) < 1) { 358 if (vfs_badlock_print) 359 printf("VOP_STRATEGY: bp is not locked but should be.\n"); 360 if (vfs_badlock_panic) 361 Debugger("Lock violation.\n"); 362 } 363 } 364 365 void 366 vop_lookup_pre(void *ap) 367 { 368 struct vop_lookup_args *a = ap; 369 struct vnode *dvp; 370 371 dvp = a->a_dvp; 372 373 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 374 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 375 } 376 377 void 378 vop_lookup_post(void *ap, int rc) 379 { 380 struct vop_lookup_args *a = ap; 381 struct componentname *cnp; 382 struct vnode *dvp; 383 struct vnode *vp; 384 int flags; 385 386 dvp = a->a_dvp; 387 cnp = a->a_cnp; 388 vp = *(a->a_vpp); 389 flags = cnp->cn_flags; 390 391 392 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 393 /* 394 * If this is the last path component for this lookup and LOCPARENT 395 * is set, OR if there is an error the directory has to be locked. 396 */ 397 if ((flags & LOCKPARENT) && (flags & ISLASTCN)) 398 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); 399 else if (rc != 0) 400 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); 401 else if (dvp != vp) 402 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); 403 404 if (flags & PDIRUNLOCK) 405 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); 406 } 407 408 void 409 vop_unlock_pre(void *ap) 410 { 411 struct vop_unlock_args *a = ap; 412 413 if (a->a_flags & LK_INTERLOCK) 414 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 415 416 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 417 } 418 419 void 420 vop_unlock_post(void *ap, int rc) 421 { 422 struct vop_unlock_args *a = ap; 423 424 if (a->a_flags & LK_INTERLOCK) 425 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 426 } 427 428 void 429 vop_lock_pre(void *ap) 430 { 431 struct vop_lock_args *a = ap; 432 433 if ((a->a_flags & LK_INTERLOCK) == 0) 434 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 435 else 436 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 437 } 438 439 void 440 vop_lock_post(void *ap, int rc) 441 { 442 struct vop_lock_args *a; 443 444 a = ap; 445 446 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 447 if (rc == 0) 448 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 449 } 450 451 void 452 v_addpollinfo(struct vnode *vp) 453 { 454 vp->v_pollinfo = uma_zalloc(vnodepoll_zone, M_WAITOK); 455 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 456 } 457 458 /* 459 * Initialize the vnode management data structures. 460 */ 461 static void 462 vntblinit(void *dummy __unused) 463 { 464 465 /* 466 * Desiredvnodes is a function of the physical memory size and 467 * the kernel's heap size. Specifically, desiredvnodes scales 468 * in proportion to the physical memory size until two fifths 469 * of the kernel's heap size is consumed by vnodes and vm 470 * objects. 471 */ 472 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / 473 (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); 474 minvnodes = desiredvnodes / 4; 475 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 476 mtx_init(&mntvnode_mtx, "mntvnode", NULL, MTX_DEF); 477 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 478 mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); 479 TAILQ_INIT(&vnode_free_list); 480 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 481 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 482 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 483 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 484 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 485 /* 486 * Initialize the filesystem syncer. 487 */ 488 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 489 &syncer_mask); 490 syncer_maxdelay = syncer_mask + 1; 491 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 492 } 493 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 494 495 496 /* 497 * Mark a mount point as busy. Used to synchronize access and to delay 498 * unmounting. Interlock is not released on failure. 499 */ 500 int 501 vfs_busy(mp, flags, interlkp, td) 502 struct mount *mp; 503 int flags; 504 struct mtx *interlkp; 505 struct thread *td; 506 { 507 int lkflags; 508 509 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 510 if (flags & LK_NOWAIT) 511 return (ENOENT); 512 mp->mnt_kern_flag |= MNTK_MWAIT; 513 /* 514 * Since all busy locks are shared except the exclusive 515 * lock granted when unmounting, the only place that a 516 * wakeup needs to be done is at the release of the 517 * exclusive lock at the end of dounmount. 518 */ 519 msleep(mp, interlkp, PVFS, "vfs_busy", 0); 520 return (ENOENT); 521 } 522 lkflags = LK_SHARED | LK_NOPAUSE; 523 if (interlkp) 524 lkflags |= LK_INTERLOCK; 525 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 526 panic("vfs_busy: unexpected lock failure"); 527 return (0); 528 } 529 530 /* 531 * Free a busy filesystem. 532 */ 533 void 534 vfs_unbusy(mp, td) 535 struct mount *mp; 536 struct thread *td; 537 { 538 539 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 540 } 541 542 /* 543 * Lookup a mount point by filesystem identifier. 544 */ 545 struct mount * 546 vfs_getvfs(fsid) 547 fsid_t *fsid; 548 { 549 register struct mount *mp; 550 551 mtx_lock(&mountlist_mtx); 552 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 553 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 554 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 555 mtx_unlock(&mountlist_mtx); 556 return (mp); 557 } 558 } 559 mtx_unlock(&mountlist_mtx); 560 return ((struct mount *) 0); 561 } 562 563 /* 564 * Get a new unique fsid. Try to make its val[0] unique, since this value 565 * will be used to create fake device numbers for stat(). Also try (but 566 * not so hard) make its val[0] unique mod 2^16, since some emulators only 567 * support 16-bit device numbers. We end up with unique val[0]'s for the 568 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 569 * 570 * Keep in mind that several mounts may be running in parallel. Starting 571 * the search one past where the previous search terminated is both a 572 * micro-optimization and a defense against returning the same fsid to 573 * different mounts. 574 */ 575 void 576 vfs_getnewfsid(mp) 577 struct mount *mp; 578 { 579 static u_int16_t mntid_base; 580 fsid_t tfsid; 581 int mtype; 582 583 mtx_lock(&mntid_mtx); 584 mtype = mp->mnt_vfc->vfc_typenum; 585 tfsid.val[1] = mtype; 586 mtype = (mtype & 0xFF) << 24; 587 for (;;) { 588 tfsid.val[0] = makeudev(255, 589 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 590 mntid_base++; 591 if (vfs_getvfs(&tfsid) == NULL) 592 break; 593 } 594 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 595 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 596 mtx_unlock(&mntid_mtx); 597 } 598 599 /* 600 * Knob to control the precision of file timestamps: 601 * 602 * 0 = seconds only; nanoseconds zeroed. 603 * 1 = seconds and nanoseconds, accurate within 1/HZ. 604 * 2 = seconds and nanoseconds, truncated to microseconds. 605 * >=3 = seconds and nanoseconds, maximum precision. 606 */ 607 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 608 609 static int timestamp_precision = TSP_SEC; 610 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 611 ×tamp_precision, 0, ""); 612 613 /* 614 * Get a current timestamp. 615 */ 616 void 617 vfs_timestamp(tsp) 618 struct timespec *tsp; 619 { 620 struct timeval tv; 621 622 switch (timestamp_precision) { 623 case TSP_SEC: 624 tsp->tv_sec = time_second; 625 tsp->tv_nsec = 0; 626 break; 627 case TSP_HZ: 628 getnanotime(tsp); 629 break; 630 case TSP_USEC: 631 microtime(&tv); 632 TIMEVAL_TO_TIMESPEC(&tv, tsp); 633 break; 634 case TSP_NSEC: 635 default: 636 nanotime(tsp); 637 break; 638 } 639 } 640 641 /* 642 * Set vnode attributes to VNOVAL 643 */ 644 void 645 vattr_null(vap) 646 register struct vattr *vap; 647 { 648 649 vap->va_type = VNON; 650 vap->va_size = VNOVAL; 651 vap->va_bytes = VNOVAL; 652 vap->va_mode = VNOVAL; 653 vap->va_nlink = VNOVAL; 654 vap->va_uid = VNOVAL; 655 vap->va_gid = VNOVAL; 656 vap->va_fsid = VNOVAL; 657 vap->va_fileid = VNOVAL; 658 vap->va_blocksize = VNOVAL; 659 vap->va_rdev = VNOVAL; 660 vap->va_atime.tv_sec = VNOVAL; 661 vap->va_atime.tv_nsec = VNOVAL; 662 vap->va_mtime.tv_sec = VNOVAL; 663 vap->va_mtime.tv_nsec = VNOVAL; 664 vap->va_ctime.tv_sec = VNOVAL; 665 vap->va_ctime.tv_nsec = VNOVAL; 666 vap->va_birthtime.tv_sec = VNOVAL; 667 vap->va_birthtime.tv_nsec = VNOVAL; 668 vap->va_flags = VNOVAL; 669 vap->va_gen = VNOVAL; 670 vap->va_vaflags = 0; 671 } 672 673 /* 674 * This routine is called when we have too many vnodes. It attempts 675 * to free <count> vnodes and will potentially free vnodes that still 676 * have VM backing store (VM backing store is typically the cause 677 * of a vnode blowout so we want to do this). Therefore, this operation 678 * is not considered cheap. 679 * 680 * A number of conditions may prevent a vnode from being reclaimed. 681 * the buffer cache may have references on the vnode, a directory 682 * vnode may still have references due to the namei cache representing 683 * underlying files, or the vnode may be in active use. It is not 684 * desireable to reuse such vnodes. These conditions may cause the 685 * number of vnodes to reach some minimum value regardless of what 686 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 687 */ 688 static int 689 vlrureclaim(struct mount *mp) 690 { 691 struct vnode *vp; 692 int done; 693 int trigger; 694 int usevnodes; 695 int count; 696 697 /* 698 * Calculate the trigger point, don't allow user 699 * screwups to blow us up. This prevents us from 700 * recycling vnodes with lots of resident pages. We 701 * aren't trying to free memory, we are trying to 702 * free vnodes. 703 */ 704 usevnodes = desiredvnodes; 705 if (usevnodes <= 0) 706 usevnodes = 1; 707 trigger = cnt.v_page_count * 2 / usevnodes; 708 709 done = 0; 710 mtx_lock(&mntvnode_mtx); 711 count = mp->mnt_nvnodelistsize / 10 + 1; 712 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 713 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 714 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 715 716 if (vp->v_type != VNON && 717 vp->v_type != VBAD && 718 VI_TRYLOCK(vp)) { 719 if (VMIGHTFREE(vp) && /* critical path opt */ 720 (vp->v_object == NULL || 721 vp->v_object->resident_page_count < trigger)) { 722 mtx_unlock(&mntvnode_mtx); 723 vgonel(vp, curthread); 724 done++; 725 mtx_lock(&mntvnode_mtx); 726 } else 727 VI_UNLOCK(vp); 728 } 729 --count; 730 } 731 mtx_unlock(&mntvnode_mtx); 732 return done; 733 } 734 735 /* 736 * Attempt to recycle vnodes in a context that is always safe to block. 737 * Calling vlrurecycle() from the bowels of filesystem code has some 738 * interesting deadlock problems. 739 */ 740 static struct proc *vnlruproc; 741 static int vnlruproc_sig; 742 743 static void 744 vnlru_proc(void) 745 { 746 struct mount *mp, *nmp; 747 int s; 748 int done; 749 struct proc *p = vnlruproc; 750 struct thread *td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ 751 752 mtx_lock(&Giant); 753 754 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 755 SHUTDOWN_PRI_FIRST); 756 757 s = splbio(); 758 for (;;) { 759 kthread_suspend_check(p); 760 mtx_lock(&vnode_free_list_mtx); 761 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 762 mtx_unlock(&vnode_free_list_mtx); 763 vnlruproc_sig = 0; 764 wakeup(&vnlruproc_sig); 765 tsleep(vnlruproc, PVFS, "vlruwt", hz); 766 continue; 767 } 768 mtx_unlock(&vnode_free_list_mtx); 769 done = 0; 770 mtx_lock(&mountlist_mtx); 771 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 772 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 773 nmp = TAILQ_NEXT(mp, mnt_list); 774 continue; 775 } 776 done += vlrureclaim(mp); 777 mtx_lock(&mountlist_mtx); 778 nmp = TAILQ_NEXT(mp, mnt_list); 779 vfs_unbusy(mp, td); 780 } 781 mtx_unlock(&mountlist_mtx); 782 if (done == 0) { 783 #if 0 784 /* These messages are temporary debugging aids */ 785 if (vnlru_nowhere < 5) 786 printf("vnlru process getting nowhere..\n"); 787 else if (vnlru_nowhere == 5) 788 printf("vnlru process messages stopped.\n"); 789 #endif 790 vnlru_nowhere++; 791 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 792 } 793 } 794 splx(s); 795 } 796 797 static struct kproc_desc vnlru_kp = { 798 "vnlru", 799 vnlru_proc, 800 &vnlruproc 801 }; 802 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 803 804 805 /* 806 * Routines having to do with the management of the vnode table. 807 */ 808 809 /* 810 * Check to see if a free vnode can be recycled. If it can, 811 * return it locked with the vn lock, but not interlock. Also 812 * get the vn_start_write lock. Otherwise indicate the error. 813 */ 814 static int 815 vcanrecycle(struct vnode *vp, struct mount **vnmpp) 816 { 817 struct thread *td = curthread; 818 vm_object_t object; 819 int error; 820 821 /* Don't recycle if we can't get the interlock */ 822 if (!VI_TRYLOCK(vp)) 823 return (EWOULDBLOCK); 824 825 /* We should be able to immediately acquire this */ 826 /* XXX This looks like it should panic if it fails */ 827 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td) != 0) { 828 if (VOP_ISLOCKED(vp, td)) 829 panic("vcanrecycle: locked vnode"); 830 return (EWOULDBLOCK); 831 } 832 833 /* 834 * Don't recycle if its filesystem is being suspended. 835 */ 836 if (vn_start_write(vp, vnmpp, V_NOWAIT) != 0) { 837 error = EBUSY; 838 goto done; 839 } 840 841 /* 842 * Don't recycle if we still have cached pages. 843 */ 844 if (VOP_GETVOBJECT(vp, &object) == 0) { 845 VM_OBJECT_LOCK(object); 846 if (object->resident_page_count || 847 object->ref_count) { 848 VM_OBJECT_UNLOCK(object); 849 error = EBUSY; 850 goto done; 851 } 852 VM_OBJECT_UNLOCK(object); 853 } 854 if (LIST_FIRST(&vp->v_cache_src)) { 855 /* 856 * note: nameileafonly sysctl is temporary, 857 * for debugging only, and will eventually be 858 * removed. 859 */ 860 if (nameileafonly > 0) { 861 /* 862 * Do not reuse namei-cached directory 863 * vnodes that have cached 864 * subdirectories. 865 */ 866 if (cache_leaf_test(vp) < 0) { 867 error = EISDIR; 868 goto done; 869 } 870 } else if (nameileafonly < 0 || 871 vmiodirenable == 0) { 872 /* 873 * Do not reuse namei-cached directory 874 * vnodes if nameileafonly is -1 or 875 * if VMIO backing for directories is 876 * turned off (otherwise we reuse them 877 * too quickly). 878 */ 879 error = EBUSY; 880 goto done; 881 } 882 } 883 return (0); 884 done: 885 VOP_UNLOCK(vp, 0, td); 886 return (error); 887 } 888 889 /* 890 * Return the next vnode from the free list. 891 */ 892 int 893 getnewvnode(tag, mp, vops, vpp) 894 const char *tag; 895 struct mount *mp; 896 vop_t **vops; 897 struct vnode **vpp; 898 { 899 struct thread *td = curthread; /* XXX */ 900 struct vnode *vp = NULL; 901 struct vpollinfo *pollinfo = NULL; 902 struct mount *vnmp; 903 904 mtx_lock(&vnode_free_list_mtx); 905 906 /* 907 * Try to reuse vnodes if we hit the max. This situation only 908 * occurs in certain large-memory (2G+) situations. We cannot 909 * attempt to directly reclaim vnodes due to nasty recursion 910 * problems. 911 */ 912 while (numvnodes - freevnodes > desiredvnodes) { 913 if (vnlruproc_sig == 0) { 914 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 915 wakeup(vnlruproc); 916 } 917 mtx_unlock(&vnode_free_list_mtx); 918 tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); 919 mtx_lock(&vnode_free_list_mtx); 920 } 921 922 /* 923 * Attempt to reuse a vnode already on the free list, allocating 924 * a new vnode if we can't find one or if we have not reached a 925 * good minimum for good LRU performance. 926 */ 927 928 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 929 int error; 930 int count; 931 932 for (count = 0; count < freevnodes; count++) { 933 vp = TAILQ_FIRST(&vnode_free_list); 934 935 KASSERT(vp->v_usecount == 0 && 936 (vp->v_iflag & VI_DOINGINACT) == 0, 937 ("getnewvnode: free vnode isn't")); 938 939 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 940 /* 941 * We have to drop the free list mtx to avoid lock 942 * order reversals with interlock. 943 */ 944 mtx_unlock(&vnode_free_list_mtx); 945 error = vcanrecycle(vp, &vnmp); 946 mtx_lock(&vnode_free_list_mtx); 947 if (error == 0) 948 break; 949 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 950 vp = NULL; 951 } 952 } 953 if (vp) { 954 freevnodes--; 955 mtx_unlock(&vnode_free_list_mtx); 956 957 cache_purge(vp); 958 VI_LOCK(vp); 959 vp->v_iflag |= VI_DOOMED; 960 vp->v_iflag &= ~VI_FREE; 961 if (vp->v_type != VBAD) { 962 VOP_UNLOCK(vp, 0, td); 963 vgonel(vp, td); 964 VI_LOCK(vp); 965 } else { 966 VOP_UNLOCK(vp, 0, td); 967 } 968 vn_finished_write(vnmp); 969 970 #ifdef INVARIANTS 971 { 972 if (vp->v_data) 973 panic("cleaned vnode isn't"); 974 if (vp->v_numoutput) 975 panic("Clean vnode has pending I/O's"); 976 if (vp->v_writecount != 0) 977 panic("Non-zero write count"); 978 } 979 #endif 980 if ((pollinfo = vp->v_pollinfo) != NULL) { 981 /* 982 * To avoid lock order reversals, the call to 983 * uma_zfree() must be delayed until the vnode 984 * interlock is released. 985 */ 986 vp->v_pollinfo = NULL; 987 } 988 #ifdef MAC 989 mac_destroy_vnode(vp); 990 #endif 991 vp->v_iflag = 0; 992 vp->v_vflag = 0; 993 vp->v_lastw = 0; 994 vp->v_lasta = 0; 995 vp->v_cstart = 0; 996 vp->v_clen = 0; 997 vp->v_socket = 0; 998 lockdestroy(vp->v_vnlock); 999 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 1000 KASSERT(vp->v_cleanbufcnt == 0, ("cleanbufcnt not 0")); 1001 KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); 1002 KASSERT(vp->v_dirtybufcnt == 0, ("dirtybufcnt not 0")); 1003 KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); 1004 } else { 1005 numvnodes++; 1006 mtx_unlock(&vnode_free_list_mtx); 1007 1008 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 1009 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 1010 VI_LOCK(vp); 1011 vp->v_dd = vp; 1012 vp->v_vnlock = &vp->v_lock; 1013 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 1014 cache_purge(vp); 1015 LIST_INIT(&vp->v_cache_src); 1016 TAILQ_INIT(&vp->v_cache_dst); 1017 } 1018 1019 TAILQ_INIT(&vp->v_cleanblkhd); 1020 TAILQ_INIT(&vp->v_dirtyblkhd); 1021 vp->v_type = VNON; 1022 vp->v_tag = tag; 1023 vp->v_op = vops; 1024 *vpp = vp; 1025 vp->v_usecount = 1; 1026 vp->v_data = 0; 1027 vp->v_cachedid = -1; 1028 VI_UNLOCK(vp); 1029 if (pollinfo != NULL) { 1030 mtx_destroy(&pollinfo->vpi_lock); 1031 uma_zfree(vnodepoll_zone, pollinfo); 1032 } 1033 #ifdef MAC 1034 mac_init_vnode(vp); 1035 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1036 mac_associate_vnode_singlelabel(mp, vp); 1037 #endif 1038 insmntque(vp, mp); 1039 1040 return (0); 1041 } 1042 1043 /* 1044 * Move a vnode from one mount queue to another. 1045 */ 1046 static void 1047 insmntque(vp, mp) 1048 register struct vnode *vp; 1049 register struct mount *mp; 1050 { 1051 1052 mtx_lock(&mntvnode_mtx); 1053 /* 1054 * Delete from old mount point vnode list, if on one. 1055 */ 1056 if (vp->v_mount != NULL) { 1057 KASSERT(vp->v_mount->mnt_nvnodelistsize > 0, 1058 ("bad mount point vnode list size")); 1059 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 1060 vp->v_mount->mnt_nvnodelistsize--; 1061 } 1062 /* 1063 * Insert into list of vnodes for the new mount point, if available. 1064 */ 1065 if ((vp->v_mount = mp) == NULL) { 1066 mtx_unlock(&mntvnode_mtx); 1067 return; 1068 } 1069 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1070 mp->mnt_nvnodelistsize++; 1071 mtx_unlock(&mntvnode_mtx); 1072 } 1073 1074 /* 1075 * Update outstanding I/O count and do wakeup if requested. 1076 */ 1077 void 1078 vwakeup(bp) 1079 register struct buf *bp; 1080 { 1081 register struct vnode *vp; 1082 1083 bp->b_flags &= ~B_WRITEINPROG; 1084 if ((vp = bp->b_vp)) { 1085 VI_LOCK(vp); 1086 vp->v_numoutput--; 1087 if (vp->v_numoutput < 0) 1088 panic("vwakeup: neg numoutput"); 1089 if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) { 1090 vp->v_iflag &= ~VI_BWAIT; 1091 wakeup(&vp->v_numoutput); 1092 } 1093 VI_UNLOCK(vp); 1094 } 1095 } 1096 1097 /* 1098 * Flush out and invalidate all buffers associated with a vnode. 1099 * Called with the underlying object locked. 1100 */ 1101 int 1102 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 1103 struct vnode *vp; 1104 int flags; 1105 struct ucred *cred; 1106 struct thread *td; 1107 int slpflag, slptimeo; 1108 { 1109 struct buf *blist; 1110 int s, error; 1111 vm_object_t object; 1112 1113 GIANT_REQUIRED; 1114 1115 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1116 1117 VI_LOCK(vp); 1118 if (flags & V_SAVE) { 1119 s = splbio(); 1120 while (vp->v_numoutput) { 1121 vp->v_iflag |= VI_BWAIT; 1122 error = msleep(&vp->v_numoutput, VI_MTX(vp), 1123 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 1124 if (error) { 1125 VI_UNLOCK(vp); 1126 splx(s); 1127 return (error); 1128 } 1129 } 1130 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1131 splx(s); 1132 VI_UNLOCK(vp); 1133 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 1134 return (error); 1135 /* 1136 * XXX We could save a lock/unlock if this was only 1137 * enabled under INVARIANTS 1138 */ 1139 VI_LOCK(vp); 1140 s = splbio(); 1141 if (vp->v_numoutput > 0 || 1142 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 1143 panic("vinvalbuf: dirty bufs"); 1144 } 1145 splx(s); 1146 } 1147 s = splbio(); 1148 /* 1149 * If you alter this loop please notice that interlock is dropped and 1150 * reacquired in flushbuflist. Special care is needed to ensure that 1151 * no race conditions occur from this. 1152 */ 1153 for (error = 0;;) { 1154 if ((blist = TAILQ_FIRST(&vp->v_cleanblkhd)) != 0 && 1155 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 1156 if (error) 1157 break; 1158 continue; 1159 } 1160 if ((blist = TAILQ_FIRST(&vp->v_dirtyblkhd)) != 0 && 1161 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 1162 if (error) 1163 break; 1164 continue; 1165 } 1166 break; 1167 } 1168 if (error) { 1169 splx(s); 1170 VI_UNLOCK(vp); 1171 return (error); 1172 } 1173 1174 /* 1175 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1176 * have write I/O in-progress but if there is a VM object then the 1177 * VM object can also have read-I/O in-progress. 1178 */ 1179 do { 1180 while (vp->v_numoutput > 0) { 1181 vp->v_iflag |= VI_BWAIT; 1182 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0); 1183 } 1184 VI_UNLOCK(vp); 1185 if (VOP_GETVOBJECT(vp, &object) == 0) { 1186 VM_OBJECT_LOCK(object); 1187 vm_object_pip_wait(object, "vnvlbx"); 1188 VM_OBJECT_UNLOCK(object); 1189 } 1190 VI_LOCK(vp); 1191 } while (vp->v_numoutput > 0); 1192 VI_UNLOCK(vp); 1193 1194 splx(s); 1195 1196 /* 1197 * Destroy the copy in the VM cache, too. 1198 */ 1199 if (VOP_GETVOBJECT(vp, &object) == 0) { 1200 VM_OBJECT_LOCK(object); 1201 vm_object_page_remove(object, 0, 0, 1202 (flags & V_SAVE) ? TRUE : FALSE); 1203 VM_OBJECT_UNLOCK(object); 1204 } 1205 1206 #ifdef INVARIANTS 1207 VI_LOCK(vp); 1208 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1209 (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || 1210 !TAILQ_EMPTY(&vp->v_cleanblkhd))) 1211 panic("vinvalbuf: flush failed"); 1212 VI_UNLOCK(vp); 1213 #endif 1214 return (0); 1215 } 1216 1217 /* 1218 * Flush out buffers on the specified list. 1219 * 1220 */ 1221 static int 1222 flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) 1223 struct buf *blist; 1224 int flags; 1225 struct vnode *vp; 1226 int slpflag, slptimeo; 1227 int *errorp; 1228 { 1229 struct buf *bp, *nbp; 1230 int found, error; 1231 1232 ASSERT_VI_LOCKED(vp, "flushbuflist"); 1233 1234 for (found = 0, bp = blist; bp; bp = nbp) { 1235 nbp = TAILQ_NEXT(bp, b_vnbufs); 1236 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1237 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1238 continue; 1239 } 1240 found += 1; 1241 error = BUF_TIMELOCK(bp, 1242 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), 1243 "flushbuf", slpflag, slptimeo); 1244 if (error) { 1245 if (error != ENOLCK) 1246 *errorp = error; 1247 goto done; 1248 } 1249 /* 1250 * XXX Since there are no node locks for NFS, I 1251 * believe there is a slight chance that a delayed 1252 * write will occur while sleeping just above, so 1253 * check for it. Note that vfs_bio_awrite expects 1254 * buffers to reside on a queue, while BUF_WRITE and 1255 * brelse do not. 1256 */ 1257 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1258 (flags & V_SAVE)) { 1259 1260 if (bp->b_vp == vp) { 1261 if (bp->b_flags & B_CLUSTEROK) { 1262 vfs_bio_awrite(bp); 1263 } else { 1264 bremfree(bp); 1265 bp->b_flags |= B_ASYNC; 1266 BUF_WRITE(bp); 1267 } 1268 } else { 1269 bremfree(bp); 1270 (void) BUF_WRITE(bp); 1271 } 1272 goto done; 1273 } 1274 bremfree(bp); 1275 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1276 bp->b_flags &= ~B_ASYNC; 1277 brelse(bp); 1278 VI_LOCK(vp); 1279 } 1280 return (found); 1281 done: 1282 VI_LOCK(vp); 1283 return (found); 1284 } 1285 1286 /* 1287 * Truncate a file's buffer and pages to a specified length. This 1288 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1289 * sync activity. 1290 */ 1291 int 1292 vtruncbuf(vp, cred, td, length, blksize) 1293 register struct vnode *vp; 1294 struct ucred *cred; 1295 struct thread *td; 1296 off_t length; 1297 int blksize; 1298 { 1299 register struct buf *bp; 1300 struct buf *nbp; 1301 int s, anyfreed; 1302 int trunclbn; 1303 1304 /* 1305 * Round up to the *next* lbn. 1306 */ 1307 trunclbn = (length + blksize - 1) / blksize; 1308 1309 s = splbio(); 1310 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1311 restart: 1312 VI_LOCK(vp); 1313 anyfreed = 1; 1314 for (;anyfreed;) { 1315 anyfreed = 0; 1316 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 1317 nbp = TAILQ_NEXT(bp, b_vnbufs); 1318 if (bp->b_lblkno >= trunclbn) { 1319 if (BUF_LOCK(bp, 1320 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1321 VI_MTX(vp)) == ENOLCK) 1322 goto restart; 1323 1324 bremfree(bp); 1325 bp->b_flags |= (B_INVAL | B_RELBUF); 1326 bp->b_flags &= ~B_ASYNC; 1327 brelse(bp); 1328 anyfreed = 1; 1329 1330 if (nbp && 1331 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1332 (nbp->b_vp != vp) || 1333 (nbp->b_flags & B_DELWRI))) { 1334 goto restart; 1335 } 1336 VI_LOCK(vp); 1337 } 1338 } 1339 1340 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1341 nbp = TAILQ_NEXT(bp, b_vnbufs); 1342 if (bp->b_lblkno >= trunclbn) { 1343 if (BUF_LOCK(bp, 1344 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1345 VI_MTX(vp)) == ENOLCK) 1346 goto restart; 1347 bremfree(bp); 1348 bp->b_flags |= (B_INVAL | B_RELBUF); 1349 bp->b_flags &= ~B_ASYNC; 1350 brelse(bp); 1351 anyfreed = 1; 1352 if (nbp && 1353 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1354 (nbp->b_vp != vp) || 1355 (nbp->b_flags & B_DELWRI) == 0)) { 1356 goto restart; 1357 } 1358 VI_LOCK(vp); 1359 } 1360 } 1361 } 1362 1363 if (length > 0) { 1364 restartsync: 1365 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1366 nbp = TAILQ_NEXT(bp, b_vnbufs); 1367 if (bp->b_lblkno > 0) 1368 continue; 1369 /* 1370 * Since we hold the vnode lock this should only 1371 * fail if we're racing with the buf daemon. 1372 */ 1373 if (BUF_LOCK(bp, 1374 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1375 VI_MTX(vp)) == ENOLCK) { 1376 goto restart; 1377 } 1378 KASSERT((bp->b_flags & B_DELWRI), 1379 ("buf(%p) on dirty queue without DELWRI.", bp)); 1380 1381 bremfree(bp); 1382 bawrite(bp); 1383 VI_LOCK(vp); 1384 goto restartsync; 1385 } 1386 } 1387 1388 while (vp->v_numoutput > 0) { 1389 vp->v_iflag |= VI_BWAIT; 1390 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0); 1391 } 1392 VI_UNLOCK(vp); 1393 splx(s); 1394 1395 vnode_pager_setsize(vp, length); 1396 1397 return (0); 1398 } 1399 1400 /* 1401 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1402 * a vnode. 1403 * 1404 * NOTE: We have to deal with the special case of a background bitmap 1405 * buffer, a situation where two buffers will have the same logical 1406 * block offset. We want (1) only the foreground buffer to be accessed 1407 * in a lookup and (2) must differentiate between the foreground and 1408 * background buffer in the splay tree algorithm because the splay 1409 * tree cannot normally handle multiple entities with the same 'index'. 1410 * We accomplish this by adding differentiating flags to the splay tree's 1411 * numerical domain. 1412 */ 1413 static 1414 struct buf * 1415 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1416 { 1417 struct buf dummy; 1418 struct buf *lefttreemax, *righttreemin, *y; 1419 1420 if (root == NULL) 1421 return (NULL); 1422 lefttreemax = righttreemin = &dummy; 1423 for (;;) { 1424 if (lblkno < root->b_lblkno || 1425 (lblkno == root->b_lblkno && 1426 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1427 if ((y = root->b_left) == NULL) 1428 break; 1429 if (lblkno < y->b_lblkno) { 1430 /* Rotate right. */ 1431 root->b_left = y->b_right; 1432 y->b_right = root; 1433 root = y; 1434 if ((y = root->b_left) == NULL) 1435 break; 1436 } 1437 /* Link into the new root's right tree. */ 1438 righttreemin->b_left = root; 1439 righttreemin = root; 1440 } else if (lblkno > root->b_lblkno || 1441 (lblkno == root->b_lblkno && 1442 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1443 if ((y = root->b_right) == NULL) 1444 break; 1445 if (lblkno > y->b_lblkno) { 1446 /* Rotate left. */ 1447 root->b_right = y->b_left; 1448 y->b_left = root; 1449 root = y; 1450 if ((y = root->b_right) == NULL) 1451 break; 1452 } 1453 /* Link into the new root's left tree. */ 1454 lefttreemax->b_right = root; 1455 lefttreemax = root; 1456 } else { 1457 break; 1458 } 1459 root = y; 1460 } 1461 /* Assemble the new root. */ 1462 lefttreemax->b_right = root->b_left; 1463 righttreemin->b_left = root->b_right; 1464 root->b_left = dummy.b_right; 1465 root->b_right = dummy.b_left; 1466 return (root); 1467 } 1468 1469 static 1470 void 1471 buf_vlist_remove(struct buf *bp) 1472 { 1473 struct vnode *vp = bp->b_vp; 1474 struct buf *root; 1475 1476 ASSERT_VI_LOCKED(vp, "buf_vlist_remove"); 1477 if (bp->b_xflags & BX_VNDIRTY) { 1478 if (bp != vp->v_dirtyblkroot) { 1479 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1480 KASSERT(root == bp, ("splay lookup failed during dirty 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_dirtyblkroot = root; 1489 TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); 1490 vp->v_dirtybufcnt--; 1491 } else { 1492 /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ 1493 if (bp != vp->v_cleanblkroot) { 1494 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1495 KASSERT(root == bp, ("splay lookup failed during clean remove")); 1496 } 1497 if (bp->b_left == NULL) { 1498 root = bp->b_right; 1499 } else { 1500 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1501 root->b_right = bp->b_right; 1502 } 1503 vp->v_cleanblkroot = root; 1504 TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); 1505 vp->v_cleanbufcnt--; 1506 } 1507 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1508 } 1509 1510 /* 1511 * Add the buffer to the sorted clean or dirty block list using a 1512 * splay tree algorithm. 1513 * 1514 * NOTE: xflags is passed as a constant, optimizing this inline function! 1515 */ 1516 static 1517 void 1518 buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) 1519 { 1520 struct buf *root; 1521 1522 ASSERT_VI_LOCKED(vp, "buf_vlist_add"); 1523 bp->b_xflags |= xflags; 1524 if (xflags & BX_VNDIRTY) { 1525 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1526 if (root == NULL) { 1527 bp->b_left = NULL; 1528 bp->b_right = NULL; 1529 TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); 1530 } else if (bp->b_lblkno < root->b_lblkno || 1531 (bp->b_lblkno == root->b_lblkno && 1532 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1533 bp->b_left = root->b_left; 1534 bp->b_right = root; 1535 root->b_left = NULL; 1536 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1537 } else { 1538 bp->b_right = root->b_right; 1539 bp->b_left = root; 1540 root->b_right = NULL; 1541 TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, 1542 root, bp, b_vnbufs); 1543 } 1544 vp->v_dirtybufcnt++; 1545 vp->v_dirtyblkroot = bp; 1546 } else { 1547 /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ 1548 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1549 if (root == NULL) { 1550 bp->b_left = NULL; 1551 bp->b_right = NULL; 1552 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1553 } else if (bp->b_lblkno < root->b_lblkno || 1554 (bp->b_lblkno == root->b_lblkno && 1555 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1556 bp->b_left = root->b_left; 1557 bp->b_right = root; 1558 root->b_left = NULL; 1559 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1560 } else { 1561 bp->b_right = root->b_right; 1562 bp->b_left = root; 1563 root->b_right = NULL; 1564 TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, 1565 root, bp, b_vnbufs); 1566 } 1567 vp->v_cleanbufcnt++; 1568 vp->v_cleanblkroot = bp; 1569 } 1570 } 1571 1572 /* 1573 * Lookup a buffer using the splay tree. Note that we specifically avoid 1574 * shadow buffers used in background bitmap writes. 1575 * 1576 * This code isn't quite efficient as it could be because we are maintaining 1577 * two sorted lists and do not know which list the block resides in. 1578 * 1579 * During a "make buildworld" the desired buffer is found at one of 1580 * the roots more than 60% of the time. Thus, checking both roots 1581 * before performing either splay eliminates unnecessary splays on the 1582 * first tree splayed. 1583 */ 1584 struct buf * 1585 gbincore(struct vnode *vp, daddr_t lblkno) 1586 { 1587 struct buf *bp; 1588 1589 GIANT_REQUIRED; 1590 1591 ASSERT_VI_LOCKED(vp, "gbincore"); 1592 if ((bp = vp->v_cleanblkroot) != NULL && 1593 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1594 return (bp); 1595 if ((bp = vp->v_dirtyblkroot) != NULL && 1596 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1597 return (bp); 1598 if ((bp = vp->v_cleanblkroot) != NULL) { 1599 vp->v_cleanblkroot = bp = buf_splay(lblkno, 0, bp); 1600 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1601 return (bp); 1602 } 1603 if ((bp = vp->v_dirtyblkroot) != NULL) { 1604 vp->v_dirtyblkroot = bp = buf_splay(lblkno, 0, bp); 1605 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1606 return (bp); 1607 } 1608 return (NULL); 1609 } 1610 1611 /* 1612 * Associate a buffer with a vnode. 1613 */ 1614 void 1615 bgetvp(vp, bp) 1616 register struct vnode *vp; 1617 register struct buf *bp; 1618 { 1619 int s; 1620 1621 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1622 1623 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1624 ("bgetvp: bp already attached! %p", bp)); 1625 1626 ASSERT_VI_LOCKED(vp, "bgetvp"); 1627 vholdl(vp); 1628 bp->b_vp = vp; 1629 bp->b_dev = vn_todev(vp); 1630 /* 1631 * Insert onto list for new vnode. 1632 */ 1633 s = splbio(); 1634 buf_vlist_add(bp, vp, BX_VNCLEAN); 1635 splx(s); 1636 } 1637 1638 /* 1639 * Disassociate a buffer from a vnode. 1640 */ 1641 void 1642 brelvp(bp) 1643 register struct buf *bp; 1644 { 1645 struct vnode *vp; 1646 int s; 1647 1648 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1649 1650 /* 1651 * Delete from old vnode list, if on one. 1652 */ 1653 vp = bp->b_vp; 1654 s = splbio(); 1655 VI_LOCK(vp); 1656 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1657 buf_vlist_remove(bp); 1658 if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1659 vp->v_iflag &= ~VI_ONWORKLST; 1660 mtx_lock(&sync_mtx); 1661 LIST_REMOVE(vp, v_synclist); 1662 mtx_unlock(&sync_mtx); 1663 } 1664 vdropl(vp); 1665 VI_UNLOCK(vp); 1666 bp->b_vp = (struct vnode *) 0; 1667 if (bp->b_object) 1668 bp->b_object = NULL; 1669 splx(s); 1670 } 1671 1672 /* 1673 * Add an item to the syncer work queue. 1674 */ 1675 static void 1676 vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1677 { 1678 int s, slot; 1679 1680 s = splbio(); 1681 ASSERT_VI_LOCKED(vp, "vn_syncer_add_to_worklist"); 1682 1683 mtx_lock(&sync_mtx); 1684 if (vp->v_iflag & VI_ONWORKLST) 1685 LIST_REMOVE(vp, v_synclist); 1686 else 1687 vp->v_iflag |= VI_ONWORKLST; 1688 1689 if (delay > syncer_maxdelay - 2) 1690 delay = syncer_maxdelay - 2; 1691 slot = (syncer_delayno + delay) & syncer_mask; 1692 1693 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1694 mtx_unlock(&sync_mtx); 1695 1696 splx(s); 1697 } 1698 1699 struct proc *updateproc; 1700 static void sched_sync(void); 1701 static struct kproc_desc up_kp = { 1702 "syncer", 1703 sched_sync, 1704 &updateproc 1705 }; 1706 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1707 1708 /* 1709 * System filesystem synchronizer daemon. 1710 */ 1711 static void 1712 sched_sync(void) 1713 { 1714 struct synclist *slp; 1715 struct vnode *vp; 1716 struct mount *mp; 1717 long starttime; 1718 int s; 1719 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); /* XXXKSE */ 1720 1721 mtx_lock(&Giant); 1722 1723 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, 1724 SHUTDOWN_PRI_LAST); 1725 1726 for (;;) { 1727 kthread_suspend_check(td->td_proc); 1728 1729 starttime = time_second; 1730 1731 /* 1732 * Push files whose dirty time has expired. Be careful 1733 * of interrupt race on slp queue. 1734 */ 1735 s = splbio(); 1736 mtx_lock(&sync_mtx); 1737 slp = &syncer_workitem_pending[syncer_delayno]; 1738 syncer_delayno += 1; 1739 if (syncer_delayno == syncer_maxdelay) 1740 syncer_delayno = 0; 1741 splx(s); 1742 1743 while ((vp = LIST_FIRST(slp)) != NULL) { 1744 mtx_unlock(&sync_mtx); 1745 if (VOP_ISLOCKED(vp, NULL) == 0 && 1746 vn_start_write(vp, &mp, V_NOWAIT) == 0) { 1747 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1748 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1749 VOP_UNLOCK(vp, 0, td); 1750 vn_finished_write(mp); 1751 } 1752 s = splbio(); 1753 mtx_lock(&sync_mtx); 1754 if (LIST_FIRST(slp) == vp) { 1755 mtx_unlock(&sync_mtx); 1756 /* 1757 * Note: VFS vnodes can remain on the 1758 * worklist too with no dirty blocks, but 1759 * since sync_fsync() moves it to a different 1760 * slot we are safe. 1761 */ 1762 VI_LOCK(vp); 1763 if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && 1764 !vn_isdisk(vp, NULL)) { 1765 panic("sched_sync: fsync failed " 1766 "vp %p tag %s", vp, vp->v_tag); 1767 } 1768 /* 1769 * Put us back on the worklist. The worklist 1770 * routine will remove us from our current 1771 * position and then add us back in at a later 1772 * position. 1773 */ 1774 vn_syncer_add_to_worklist(vp, syncdelay); 1775 VI_UNLOCK(vp); 1776 mtx_lock(&sync_mtx); 1777 } 1778 splx(s); 1779 } 1780 mtx_unlock(&sync_mtx); 1781 1782 /* 1783 * Do soft update processing. 1784 */ 1785 if (softdep_process_worklist_hook != NULL) 1786 (*softdep_process_worklist_hook)(NULL); 1787 1788 /* 1789 * The variable rushjob allows the kernel to speed up the 1790 * processing of the filesystem syncer process. A rushjob 1791 * value of N tells the filesystem syncer to process the next 1792 * N seconds worth of work on its queue ASAP. Currently rushjob 1793 * is used by the soft update code to speed up the filesystem 1794 * syncer process when the incore state is getting so far 1795 * ahead of the disk that the kernel memory pool is being 1796 * threatened with exhaustion. 1797 */ 1798 mtx_lock(&sync_mtx); 1799 if (rushjob > 0) { 1800 rushjob -= 1; 1801 mtx_unlock(&sync_mtx); 1802 continue; 1803 } 1804 mtx_unlock(&sync_mtx); 1805 /* 1806 * If it has taken us less than a second to process the 1807 * current work, then wait. Otherwise start right over 1808 * again. We can still lose time if any single round 1809 * takes more than two seconds, but it does not really 1810 * matter as we are just trying to generally pace the 1811 * filesystem activity. 1812 */ 1813 if (time_second == starttime) 1814 tsleep(&lbolt, PPAUSE, "syncer", 0); 1815 } 1816 } 1817 1818 /* 1819 * Request the syncer daemon to speed up its work. 1820 * We never push it to speed up more than half of its 1821 * normal turn time, otherwise it could take over the cpu. 1822 * XXXKSE only one update? 1823 */ 1824 int 1825 speedup_syncer() 1826 { 1827 struct thread *td; 1828 int ret = 0; 1829 1830 td = FIRST_THREAD_IN_PROC(updateproc); 1831 mtx_lock_spin(&sched_lock); 1832 if (td->td_wchan == &lbolt) { 1833 unsleep(td); 1834 TD_CLR_SLEEPING(td); 1835 setrunnable(td); 1836 } 1837 mtx_unlock_spin(&sched_lock); 1838 mtx_lock(&sync_mtx); 1839 if (rushjob < syncdelay / 2) { 1840 rushjob += 1; 1841 stat_rush_requests += 1; 1842 ret = 1; 1843 } 1844 mtx_unlock(&sync_mtx); 1845 return (ret); 1846 } 1847 1848 /* 1849 * Associate a p-buffer with a vnode. 1850 * 1851 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1852 * with the buffer. i.e. the bp has not been linked into the vnode or 1853 * ref-counted. 1854 */ 1855 void 1856 pbgetvp(vp, bp) 1857 register struct vnode *vp; 1858 register struct buf *bp; 1859 { 1860 1861 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1862 1863 bp->b_vp = vp; 1864 bp->b_flags |= B_PAGING; 1865 bp->b_dev = vn_todev(vp); 1866 } 1867 1868 /* 1869 * Disassociate a p-buffer from a vnode. 1870 */ 1871 void 1872 pbrelvp(bp) 1873 register struct buf *bp; 1874 { 1875 1876 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1877 1878 /* XXX REMOVE ME */ 1879 VI_LOCK(bp->b_vp); 1880 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1881 panic( 1882 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1883 bp, 1884 (int)bp->b_flags 1885 ); 1886 } 1887 VI_UNLOCK(bp->b_vp); 1888 bp->b_vp = (struct vnode *) 0; 1889 bp->b_flags &= ~B_PAGING; 1890 } 1891 1892 /* 1893 * Reassign a buffer from one vnode to another. 1894 * Used to assign file specific control information 1895 * (indirect blocks) to the vnode to which they belong. 1896 */ 1897 void 1898 reassignbuf(bp, newvp) 1899 register struct buf *bp; 1900 register struct vnode *newvp; 1901 { 1902 int delay; 1903 int s; 1904 1905 if (newvp == NULL) { 1906 printf("reassignbuf: NULL"); 1907 return; 1908 } 1909 ++reassignbufcalls; 1910 1911 /* 1912 * B_PAGING flagged buffers cannot be reassigned because their vp 1913 * is not fully linked in. 1914 */ 1915 if (bp->b_flags & B_PAGING) 1916 panic("cannot reassign paging buffer"); 1917 1918 s = splbio(); 1919 /* 1920 * Delete from old vnode list, if on one. 1921 */ 1922 VI_LOCK(bp->b_vp); 1923 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1924 buf_vlist_remove(bp); 1925 if (bp->b_vp != newvp) { 1926 vdropl(bp->b_vp); 1927 bp->b_vp = NULL; /* for clarification */ 1928 } 1929 } 1930 VI_UNLOCK(bp->b_vp); 1931 /* 1932 * If dirty, put on list of dirty buffers; otherwise insert onto list 1933 * of clean buffers. 1934 */ 1935 VI_LOCK(newvp); 1936 if (bp->b_flags & B_DELWRI) { 1937 if ((newvp->v_iflag & VI_ONWORKLST) == 0) { 1938 switch (newvp->v_type) { 1939 case VDIR: 1940 delay = dirdelay; 1941 break; 1942 case VCHR: 1943 if (newvp->v_rdev->si_mountpoint != NULL) { 1944 delay = metadelay; 1945 break; 1946 } 1947 /* FALLTHROUGH */ 1948 default: 1949 delay = filedelay; 1950 } 1951 vn_syncer_add_to_worklist(newvp, delay); 1952 } 1953 buf_vlist_add(bp, newvp, BX_VNDIRTY); 1954 } else { 1955 buf_vlist_add(bp, newvp, BX_VNCLEAN); 1956 1957 if ((newvp->v_iflag & VI_ONWORKLST) && 1958 TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { 1959 mtx_lock(&sync_mtx); 1960 LIST_REMOVE(newvp, v_synclist); 1961 mtx_unlock(&sync_mtx); 1962 newvp->v_iflag &= ~VI_ONWORKLST; 1963 } 1964 } 1965 if (bp->b_vp != newvp) { 1966 bp->b_vp = newvp; 1967 vholdl(bp->b_vp); 1968 } 1969 VI_UNLOCK(newvp); 1970 splx(s); 1971 } 1972 1973 /* 1974 * Create a vnode for a device. 1975 * Used for mounting the root filesystem. 1976 */ 1977 int 1978 bdevvp(dev, vpp) 1979 dev_t dev; 1980 struct vnode **vpp; 1981 { 1982 register struct vnode *vp; 1983 struct vnode *nvp; 1984 int error; 1985 1986 if (dev == NODEV) { 1987 *vpp = NULLVP; 1988 return (ENXIO); 1989 } 1990 if (vfinddev(dev, VCHR, vpp)) 1991 return (0); 1992 error = getnewvnode("none", (struct mount *)0, spec_vnodeop_p, &nvp); 1993 if (error) { 1994 *vpp = NULLVP; 1995 return (error); 1996 } 1997 vp = nvp; 1998 vp->v_type = VCHR; 1999 addalias(vp, dev); 2000 *vpp = vp; 2001 return (0); 2002 } 2003 2004 static void 2005 v_incr_usecount(struct vnode *vp, int delta) 2006 { 2007 vp->v_usecount += delta; 2008 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2009 mtx_lock(&spechash_mtx); 2010 vp->v_rdev->si_usecount += delta; 2011 mtx_unlock(&spechash_mtx); 2012 } 2013 } 2014 2015 /* 2016 * Add vnode to the alias list hung off the dev_t. 2017 * 2018 * The reason for this gunk is that multiple vnodes can reference 2019 * the same physical device, so checking vp->v_usecount to see 2020 * how many users there are is inadequate; the v_usecount for 2021 * the vnodes need to be accumulated. vcount() does that. 2022 */ 2023 struct vnode * 2024 addaliasu(nvp, nvp_rdev) 2025 struct vnode *nvp; 2026 udev_t nvp_rdev; 2027 { 2028 struct vnode *ovp; 2029 vop_t **ops; 2030 dev_t dev; 2031 2032 if (nvp->v_type == VBLK) 2033 return (nvp); 2034 if (nvp->v_type != VCHR) 2035 panic("addaliasu on non-special vnode"); 2036 dev = udev2dev(nvp_rdev, 0); 2037 /* 2038 * Check to see if we have a bdevvp vnode with no associated 2039 * filesystem. If so, we want to associate the filesystem of 2040 * the new newly instigated vnode with the bdevvp vnode and 2041 * discard the newly created vnode rather than leaving the 2042 * bdevvp vnode lying around with no associated filesystem. 2043 */ 2044 if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { 2045 addalias(nvp, dev); 2046 return (nvp); 2047 } 2048 /* 2049 * Discard unneeded vnode, but save its node specific data. 2050 * Note that if there is a lock, it is carried over in the 2051 * node specific data to the replacement vnode. 2052 */ 2053 vref(ovp); 2054 ovp->v_data = nvp->v_data; 2055 ovp->v_tag = nvp->v_tag; 2056 nvp->v_data = NULL; 2057 lockdestroy(ovp->v_vnlock); 2058 lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, 2059 nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); 2060 ops = ovp->v_op; 2061 ovp->v_op = nvp->v_op; 2062 if (VOP_ISLOCKED(nvp, curthread)) { 2063 VOP_UNLOCK(nvp, 0, curthread); 2064 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 2065 } 2066 nvp->v_op = ops; 2067 insmntque(ovp, nvp->v_mount); 2068 vrele(nvp); 2069 vgone(nvp); 2070 return (ovp); 2071 } 2072 2073 /* This is a local helper function that do the same as addaliasu, but for a 2074 * dev_t instead of an udev_t. */ 2075 static void 2076 addalias(nvp, dev) 2077 struct vnode *nvp; 2078 dev_t dev; 2079 { 2080 2081 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 2082 nvp->v_rdev = dev; 2083 VI_LOCK(nvp); 2084 mtx_lock(&spechash_mtx); 2085 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 2086 dev->si_usecount += nvp->v_usecount; 2087 mtx_unlock(&spechash_mtx); 2088 VI_UNLOCK(nvp); 2089 } 2090 2091 /* 2092 * Grab a particular vnode from the free list, increment its 2093 * reference count and lock it. The vnode lock bit is set if the 2094 * vnode is being eliminated in vgone. The process is awakened 2095 * when the transition is completed, and an error returned to 2096 * indicate that the vnode is no longer usable (possibly having 2097 * been changed to a new filesystem type). 2098 */ 2099 int 2100 vget(vp, flags, td) 2101 register struct vnode *vp; 2102 int flags; 2103 struct thread *td; 2104 { 2105 int error; 2106 2107 /* 2108 * If the vnode is in the process of being cleaned out for 2109 * another use, we wait for the cleaning to finish and then 2110 * return failure. Cleaning is determined by checking that 2111 * the VI_XLOCK flag is set. 2112 */ 2113 if ((flags & LK_INTERLOCK) == 0) 2114 VI_LOCK(vp); 2115 if (vp->v_iflag & VI_XLOCK && vp->v_vxproc != curthread) { 2116 vp->v_iflag |= VI_XWANT; 2117 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); 2118 return (ENOENT); 2119 } 2120 2121 v_incr_usecount(vp, 1); 2122 2123 if (VSHOULDBUSY(vp)) 2124 vbusy(vp); 2125 if (flags & LK_TYPE_MASK) { 2126 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 2127 /* 2128 * must expand vrele here because we do not want 2129 * to call VOP_INACTIVE if the reference count 2130 * drops back to zero since it was never really 2131 * active. We must remove it from the free list 2132 * before sleeping so that multiple processes do 2133 * not try to recycle it. 2134 */ 2135 VI_LOCK(vp); 2136 v_incr_usecount(vp, -1); 2137 if (VSHOULDFREE(vp)) 2138 vfree(vp); 2139 else 2140 vlruvp(vp); 2141 VI_UNLOCK(vp); 2142 } 2143 return (error); 2144 } 2145 VI_UNLOCK(vp); 2146 return (0); 2147 } 2148 2149 /* 2150 * Increase the reference count of a vnode. 2151 */ 2152 void 2153 vref(struct vnode *vp) 2154 { 2155 VI_LOCK(vp); 2156 v_incr_usecount(vp, 1); 2157 VI_UNLOCK(vp); 2158 } 2159 2160 /* 2161 * Return reference count of a vnode. 2162 * 2163 * The results of this call are only guaranteed when some mechanism other 2164 * than the VI lock is used to stop other processes from gaining references 2165 * to the vnode. This may be the case if the caller holds the only reference. 2166 * This is also useful when stale data is acceptable as race conditions may 2167 * be accounted for by some other means. 2168 */ 2169 int 2170 vrefcnt(struct vnode *vp) 2171 { 2172 int usecnt; 2173 2174 VI_LOCK(vp); 2175 usecnt = vp->v_usecount; 2176 VI_UNLOCK(vp); 2177 2178 return (usecnt); 2179 } 2180 2181 2182 /* 2183 * Vnode put/release. 2184 * If count drops to zero, call inactive routine and return to freelist. 2185 */ 2186 void 2187 vrele(vp) 2188 struct vnode *vp; 2189 { 2190 struct thread *td = curthread; /* XXX */ 2191 2192 KASSERT(vp != NULL, ("vrele: null vp")); 2193 2194 VI_LOCK(vp); 2195 2196 /* Skip this v_writecount check if we're going to panic below. */ 2197 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2198 ("vrele: missed vn_close")); 2199 2200 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2201 vp->v_usecount == 1)) { 2202 v_incr_usecount(vp, -1); 2203 VI_UNLOCK(vp); 2204 2205 return; 2206 } 2207 2208 if (vp->v_usecount == 1) { 2209 v_incr_usecount(vp, -1); 2210 /* 2211 * We must call VOP_INACTIVE with the node locked. Mark 2212 * as VI_DOINGINACT to avoid recursion. 2213 */ 2214 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 2215 VI_LOCK(vp); 2216 vp->v_iflag |= VI_DOINGINACT; 2217 VI_UNLOCK(vp); 2218 VOP_INACTIVE(vp, td); 2219 VI_LOCK(vp); 2220 KASSERT(vp->v_iflag & VI_DOINGINACT, 2221 ("vrele: lost VI_DOINGINACT")); 2222 vp->v_iflag &= ~VI_DOINGINACT; 2223 } else 2224 VI_LOCK(vp); 2225 if (VSHOULDFREE(vp)) 2226 vfree(vp); 2227 else 2228 vlruvp(vp); 2229 VI_UNLOCK(vp); 2230 2231 } else { 2232 #ifdef DIAGNOSTIC 2233 vprint("vrele: negative ref count", vp); 2234 #endif 2235 VI_UNLOCK(vp); 2236 panic("vrele: negative ref cnt"); 2237 } 2238 } 2239 2240 /* 2241 * Release an already locked vnode. This give the same effects as 2242 * unlock+vrele(), but takes less time and avoids releasing and 2243 * re-aquiring the lock (as vrele() aquires the lock internally.) 2244 */ 2245 void 2246 vput(vp) 2247 struct vnode *vp; 2248 { 2249 struct thread *td = curthread; /* XXX */ 2250 2251 GIANT_REQUIRED; 2252 2253 KASSERT(vp != NULL, ("vput: null vp")); 2254 VI_LOCK(vp); 2255 /* Skip this v_writecount check if we're going to panic below. */ 2256 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2257 ("vput: missed vn_close")); 2258 2259 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2260 vp->v_usecount == 1)) { 2261 v_incr_usecount(vp, -1); 2262 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2263 return; 2264 } 2265 2266 if (vp->v_usecount == 1) { 2267 v_incr_usecount(vp, -1); 2268 /* 2269 * We must call VOP_INACTIVE with the node locked, so 2270 * we just need to release the vnode mutex. Mark as 2271 * as VI_DOINGINACT to avoid recursion. 2272 */ 2273 vp->v_iflag |= VI_DOINGINACT; 2274 VI_UNLOCK(vp); 2275 VOP_INACTIVE(vp, td); 2276 VI_LOCK(vp); 2277 KASSERT(vp->v_iflag & VI_DOINGINACT, 2278 ("vput: lost VI_DOINGINACT")); 2279 vp->v_iflag &= ~VI_DOINGINACT; 2280 if (VSHOULDFREE(vp)) 2281 vfree(vp); 2282 else 2283 vlruvp(vp); 2284 VI_UNLOCK(vp); 2285 2286 } else { 2287 #ifdef DIAGNOSTIC 2288 vprint("vput: negative ref count", vp); 2289 #endif 2290 panic("vput: negative ref cnt"); 2291 } 2292 } 2293 2294 /* 2295 * Somebody doesn't want the vnode recycled. 2296 */ 2297 void 2298 vhold(struct vnode *vp) 2299 { 2300 VI_LOCK(vp); 2301 vholdl(vp); 2302 VI_UNLOCK(vp); 2303 } 2304 2305 void 2306 vholdl(vp) 2307 register struct vnode *vp; 2308 { 2309 int s; 2310 2311 s = splbio(); 2312 vp->v_holdcnt++; 2313 if (VSHOULDBUSY(vp)) 2314 vbusy(vp); 2315 splx(s); 2316 } 2317 2318 /* 2319 * Note that there is one less who cares about this vnode. vdrop() is the 2320 * opposite of vhold(). 2321 */ 2322 void 2323 vdrop(struct vnode *vp) 2324 { 2325 VI_LOCK(vp); 2326 vdropl(vp); 2327 VI_UNLOCK(vp); 2328 } 2329 2330 void 2331 vdropl(vp) 2332 register struct vnode *vp; 2333 { 2334 int s; 2335 2336 s = splbio(); 2337 if (vp->v_holdcnt <= 0) 2338 panic("vdrop: holdcnt"); 2339 vp->v_holdcnt--; 2340 if (VSHOULDFREE(vp)) 2341 vfree(vp); 2342 else 2343 vlruvp(vp); 2344 splx(s); 2345 } 2346 2347 /* 2348 * Remove any vnodes in the vnode table belonging to mount point mp. 2349 * 2350 * If FORCECLOSE is not specified, there should not be any active ones, 2351 * return error if any are found (nb: this is a user error, not a 2352 * system error). If FORCECLOSE is specified, detach any active vnodes 2353 * that are found. 2354 * 2355 * If WRITECLOSE is set, only flush out regular file vnodes open for 2356 * writing. 2357 * 2358 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2359 * 2360 * `rootrefs' specifies the base reference count for the root vnode 2361 * of this filesystem. The root vnode is considered busy if its 2362 * v_usecount exceeds this value. On a successful return, vflush() 2363 * will call vrele() on the root vnode exactly rootrefs times. 2364 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2365 * be zero. 2366 */ 2367 #ifdef DIAGNOSTIC 2368 static int busyprt = 0; /* print out busy vnodes */ 2369 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2370 #endif 2371 2372 int 2373 vflush(mp, rootrefs, flags) 2374 struct mount *mp; 2375 int rootrefs; 2376 int flags; 2377 { 2378 struct thread *td = curthread; /* XXX */ 2379 struct vnode *vp, *nvp, *rootvp = NULL; 2380 struct vattr vattr; 2381 int busy = 0, error; 2382 2383 if (rootrefs > 0) { 2384 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2385 ("vflush: bad args")); 2386 /* 2387 * Get the filesystem root vnode. We can vput() it 2388 * immediately, since with rootrefs > 0, it won't go away. 2389 */ 2390 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 2391 return (error); 2392 vput(rootvp); 2393 2394 } 2395 mtx_lock(&mntvnode_mtx); 2396 loop: 2397 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 2398 /* 2399 * Make sure this vnode wasn't reclaimed in getnewvnode(). 2400 * Start over if it has (it won't be on the list anymore). 2401 */ 2402 if (vp->v_mount != mp) 2403 goto loop; 2404 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2405 2406 VI_LOCK(vp); 2407 mtx_unlock(&mntvnode_mtx); 2408 vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY, td); 2409 /* 2410 * This vnode could have been reclaimed while we were 2411 * waiting for the lock since we are not holding a 2412 * reference. 2413 * Start over if the vnode was reclaimed. 2414 */ 2415 if (vp->v_mount != mp) { 2416 VOP_UNLOCK(vp, 0, td); 2417 mtx_lock(&mntvnode_mtx); 2418 goto loop; 2419 } 2420 /* 2421 * Skip over a vnodes marked VV_SYSTEM. 2422 */ 2423 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2424 VOP_UNLOCK(vp, 0, td); 2425 mtx_lock(&mntvnode_mtx); 2426 continue; 2427 } 2428 /* 2429 * If WRITECLOSE is set, flush out unlinked but still open 2430 * files (even if open only for reading) and regular file 2431 * vnodes open for writing. 2432 */ 2433 if (flags & WRITECLOSE) { 2434 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2435 VI_LOCK(vp); 2436 2437 if ((vp->v_type == VNON || 2438 (error == 0 && vattr.va_nlink > 0)) && 2439 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2440 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2441 mtx_lock(&mntvnode_mtx); 2442 continue; 2443 } 2444 } else 2445 VI_LOCK(vp); 2446 2447 VOP_UNLOCK(vp, 0, td); 2448 2449 /* 2450 * With v_usecount == 0, all we need to do is clear out the 2451 * vnode data structures and we are done. 2452 */ 2453 if (vp->v_usecount == 0) { 2454 vgonel(vp, td); 2455 mtx_lock(&mntvnode_mtx); 2456 continue; 2457 } 2458 2459 /* 2460 * If FORCECLOSE is set, forcibly close the vnode. For block 2461 * or character devices, revert to an anonymous device. For 2462 * all other files, just kill them. 2463 */ 2464 if (flags & FORCECLOSE) { 2465 if (vp->v_type != VCHR) { 2466 vgonel(vp, td); 2467 } else { 2468 vclean(vp, 0, td); 2469 VI_UNLOCK(vp); 2470 vp->v_op = spec_vnodeop_p; 2471 insmntque(vp, (struct mount *) 0); 2472 } 2473 mtx_lock(&mntvnode_mtx); 2474 continue; 2475 } 2476 #ifdef DIAGNOSTIC 2477 if (busyprt) 2478 vprint("vflush: busy vnode", vp); 2479 #endif 2480 VI_UNLOCK(vp); 2481 mtx_lock(&mntvnode_mtx); 2482 busy++; 2483 } 2484 mtx_unlock(&mntvnode_mtx); 2485 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2486 /* 2487 * If just the root vnode is busy, and if its refcount 2488 * is equal to `rootrefs', then go ahead and kill it. 2489 */ 2490 VI_LOCK(rootvp); 2491 KASSERT(busy > 0, ("vflush: not busy")); 2492 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 2493 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2494 vgonel(rootvp, td); 2495 busy = 0; 2496 } else 2497 VI_UNLOCK(rootvp); 2498 } 2499 if (busy) 2500 return (EBUSY); 2501 for (; rootrefs > 0; rootrefs--) 2502 vrele(rootvp); 2503 return (0); 2504 } 2505 2506 /* 2507 * This moves a now (likely recyclable) vnode to the end of the 2508 * mountlist. XXX However, it is temporarily disabled until we 2509 * can clean up ffs_sync() and friends, which have loop restart 2510 * conditions which this code causes to operate O(N^2). 2511 */ 2512 static void 2513 vlruvp(struct vnode *vp) 2514 { 2515 #if 0 2516 struct mount *mp; 2517 2518 if ((mp = vp->v_mount) != NULL) { 2519 mtx_lock(&mntvnode_mtx); 2520 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2521 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2522 mtx_unlock(&mntvnode_mtx); 2523 } 2524 #endif 2525 } 2526 2527 /* 2528 * Disassociate the underlying filesystem from a vnode. 2529 */ 2530 static void 2531 vclean(vp, flags, td) 2532 struct vnode *vp; 2533 int flags; 2534 struct thread *td; 2535 { 2536 int active; 2537 2538 ASSERT_VI_LOCKED(vp, "vclean"); 2539 /* 2540 * Check to see if the vnode is in use. If so we have to reference it 2541 * before we clean it out so that its count cannot fall to zero and 2542 * generate a race against ourselves to recycle it. 2543 */ 2544 if ((active = vp->v_usecount)) 2545 v_incr_usecount(vp, 1); 2546 2547 /* 2548 * Prevent the vnode from being recycled or brought into use while we 2549 * clean it out. 2550 */ 2551 if (vp->v_iflag & VI_XLOCK) 2552 panic("vclean: deadlock"); 2553 vp->v_iflag |= VI_XLOCK; 2554 vp->v_vxproc = curthread; 2555 /* 2556 * Even if the count is zero, the VOP_INACTIVE routine may still 2557 * have the object locked while it cleans it out. The VOP_LOCK 2558 * ensures that the VOP_INACTIVE routine is done with its work. 2559 * For active vnodes, it ensures that no other activity can 2560 * occur while the underlying object is being cleaned out. 2561 */ 2562 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2563 2564 /* 2565 * Clean out any buffers associated with the vnode. 2566 * If the flush fails, just toss the buffers. 2567 */ 2568 if (flags & DOCLOSE) { 2569 struct buf *bp; 2570 VI_LOCK(vp); 2571 bp = TAILQ_FIRST(&vp->v_dirtyblkhd); 2572 VI_UNLOCK(vp); 2573 if (bp != NULL) 2574 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2575 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2576 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2577 } 2578 2579 VOP_DESTROYVOBJECT(vp); 2580 2581 /* 2582 * Any other processes trying to obtain this lock must first 2583 * wait for VXLOCK to clear, then call the new lock operation. 2584 */ 2585 VOP_UNLOCK(vp, 0, td); 2586 2587 /* 2588 * If purging an active vnode, it must be closed and 2589 * deactivated before being reclaimed. Note that the 2590 * VOP_INACTIVE will unlock the vnode. 2591 */ 2592 if (active) { 2593 if (flags & DOCLOSE) 2594 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2595 VI_LOCK(vp); 2596 if ((vp->v_iflag & VI_DOINGINACT) == 0) { 2597 vp->v_iflag |= VI_DOINGINACT; 2598 VI_UNLOCK(vp); 2599 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2600 panic("vclean: cannot relock."); 2601 VOP_INACTIVE(vp, td); 2602 VI_LOCK(vp); 2603 KASSERT(vp->v_iflag & VI_DOINGINACT, 2604 ("vclean: lost VI_DOINGINACT")); 2605 vp->v_iflag &= ~VI_DOINGINACT; 2606 } 2607 VI_UNLOCK(vp); 2608 } 2609 2610 /* 2611 * Reclaim the vnode. 2612 */ 2613 if (VOP_RECLAIM(vp, td)) 2614 panic("vclean: cannot reclaim"); 2615 2616 if (active) { 2617 /* 2618 * Inline copy of vrele() since VOP_INACTIVE 2619 * has already been called. 2620 */ 2621 VI_LOCK(vp); 2622 v_incr_usecount(vp, -1); 2623 if (vp->v_usecount <= 0) { 2624 #ifdef DIAGNOSTIC 2625 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2626 vprint("vclean: bad ref count", vp); 2627 panic("vclean: ref cnt"); 2628 } 2629 #endif 2630 vfree(vp); 2631 } 2632 VI_UNLOCK(vp); 2633 } 2634 2635 cache_purge(vp); 2636 VI_LOCK(vp); 2637 if (VSHOULDFREE(vp)) 2638 vfree(vp); 2639 2640 /* 2641 * Done with purge, reset to the standard lock and 2642 * notify sleepers of the grim news. 2643 */ 2644 vp->v_vnlock = &vp->v_lock; 2645 vp->v_op = dead_vnodeop_p; 2646 if (vp->v_pollinfo != NULL) 2647 vn_pollgone(vp); 2648 vp->v_tag = "none"; 2649 vp->v_iflag &= ~VI_XLOCK; 2650 vp->v_vxproc = NULL; 2651 if (vp->v_iflag & VI_XWANT) { 2652 vp->v_iflag &= ~VI_XWANT; 2653 wakeup(vp); 2654 } 2655 } 2656 2657 /* 2658 * Eliminate all activity associated with the requested vnode 2659 * and with all vnodes aliased to the requested vnode. 2660 */ 2661 int 2662 vop_revoke(ap) 2663 struct vop_revoke_args /* { 2664 struct vnode *a_vp; 2665 int a_flags; 2666 } */ *ap; 2667 { 2668 struct vnode *vp, *vq; 2669 dev_t dev; 2670 2671 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2672 vp = ap->a_vp; 2673 KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); 2674 2675 VI_LOCK(vp); 2676 /* 2677 * If a vgone (or vclean) is already in progress, 2678 * wait until it is done and return. 2679 */ 2680 if (vp->v_iflag & VI_XLOCK) { 2681 vp->v_iflag |= VI_XWANT; 2682 msleep(vp, VI_MTX(vp), PINOD | PDROP, 2683 "vop_revokeall", 0); 2684 return (0); 2685 } 2686 VI_UNLOCK(vp); 2687 dev = vp->v_rdev; 2688 for (;;) { 2689 mtx_lock(&spechash_mtx); 2690 vq = SLIST_FIRST(&dev->si_hlist); 2691 mtx_unlock(&spechash_mtx); 2692 if (!vq) 2693 break; 2694 vgone(vq); 2695 } 2696 return (0); 2697 } 2698 2699 /* 2700 * Recycle an unused vnode to the front of the free list. 2701 * Release the passed interlock if the vnode will be recycled. 2702 */ 2703 int 2704 vrecycle(vp, inter_lkp, td) 2705 struct vnode *vp; 2706 struct mtx *inter_lkp; 2707 struct thread *td; 2708 { 2709 2710 VI_LOCK(vp); 2711 if (vp->v_usecount == 0) { 2712 if (inter_lkp) { 2713 mtx_unlock(inter_lkp); 2714 } 2715 vgonel(vp, td); 2716 return (1); 2717 } 2718 VI_UNLOCK(vp); 2719 return (0); 2720 } 2721 2722 /* 2723 * Eliminate all activity associated with a vnode 2724 * in preparation for reuse. 2725 */ 2726 void 2727 vgone(vp) 2728 register struct vnode *vp; 2729 { 2730 struct thread *td = curthread; /* XXX */ 2731 2732 VI_LOCK(vp); 2733 vgonel(vp, td); 2734 } 2735 2736 /* 2737 * vgone, with the vp interlock held. 2738 */ 2739 void 2740 vgonel(vp, td) 2741 struct vnode *vp; 2742 struct thread *td; 2743 { 2744 int s; 2745 2746 /* 2747 * If a vgone (or vclean) is already in progress, 2748 * wait until it is done and return. 2749 */ 2750 ASSERT_VI_LOCKED(vp, "vgonel"); 2751 if (vp->v_iflag & VI_XLOCK) { 2752 vp->v_iflag |= VI_XWANT; 2753 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); 2754 return; 2755 } 2756 2757 /* 2758 * Clean out the filesystem specific data. 2759 */ 2760 vclean(vp, DOCLOSE, td); 2761 VI_UNLOCK(vp); 2762 2763 /* 2764 * Delete from old mount point vnode list, if on one. 2765 */ 2766 if (vp->v_mount != NULL) 2767 insmntque(vp, (struct mount *)0); 2768 /* 2769 * If special device, remove it from special device alias list 2770 * if it is on one. 2771 */ 2772 if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { 2773 VI_LOCK(vp); 2774 mtx_lock(&spechash_mtx); 2775 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2776 vp->v_rdev->si_usecount -= vp->v_usecount; 2777 mtx_unlock(&spechash_mtx); 2778 VI_UNLOCK(vp); 2779 vp->v_rdev = NULL; 2780 } 2781 2782 /* 2783 * If it is on the freelist and not already at the head, 2784 * move it to the head of the list. The test of the 2785 * VDOOMED flag and the reference count of zero is because 2786 * it will be removed from the free list by getnewvnode, 2787 * but will not have its reference count incremented until 2788 * after calling vgone. If the reference count were 2789 * incremented first, vgone would (incorrectly) try to 2790 * close the previous instance of the underlying object. 2791 */ 2792 VI_LOCK(vp); 2793 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2794 s = splbio(); 2795 mtx_lock(&vnode_free_list_mtx); 2796 if (vp->v_iflag & VI_FREE) { 2797 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2798 } else { 2799 vp->v_iflag |= VI_FREE; 2800 freevnodes++; 2801 } 2802 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2803 mtx_unlock(&vnode_free_list_mtx); 2804 splx(s); 2805 } 2806 2807 vp->v_type = VBAD; 2808 VI_UNLOCK(vp); 2809 } 2810 2811 /* 2812 * Lookup a vnode by device number. 2813 */ 2814 int 2815 vfinddev(dev, type, vpp) 2816 dev_t dev; 2817 enum vtype type; 2818 struct vnode **vpp; 2819 { 2820 struct vnode *vp; 2821 2822 mtx_lock(&spechash_mtx); 2823 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2824 if (type == vp->v_type) { 2825 *vpp = vp; 2826 mtx_unlock(&spechash_mtx); 2827 return (1); 2828 } 2829 } 2830 mtx_unlock(&spechash_mtx); 2831 return (0); 2832 } 2833 2834 /* 2835 * Calculate the total number of references to a special device. 2836 */ 2837 int 2838 vcount(vp) 2839 struct vnode *vp; 2840 { 2841 int count; 2842 2843 mtx_lock(&spechash_mtx); 2844 count = vp->v_rdev->si_usecount; 2845 mtx_unlock(&spechash_mtx); 2846 return (count); 2847 } 2848 2849 /* 2850 * Same as above, but using the dev_t as argument 2851 */ 2852 int 2853 count_dev(dev) 2854 dev_t dev; 2855 { 2856 struct vnode *vp; 2857 2858 vp = SLIST_FIRST(&dev->si_hlist); 2859 if (vp == NULL) 2860 return (0); 2861 return(vcount(vp)); 2862 } 2863 2864 /* 2865 * Print out a description of a vnode. 2866 */ 2867 static char *typename[] = 2868 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2869 2870 void 2871 vprint(label, vp) 2872 char *label; 2873 struct vnode *vp; 2874 { 2875 char buf[96]; 2876 2877 if (label != NULL) 2878 printf("%s: %p: ", label, (void *)vp); 2879 else 2880 printf("%p: ", (void *)vp); 2881 printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", 2882 vp->v_tag, typename[vp->v_type], vp->v_usecount, 2883 vp->v_writecount, vp->v_holdcnt); 2884 buf[0] = '\0'; 2885 if (vp->v_vflag & VV_ROOT) 2886 strcat(buf, "|VV_ROOT"); 2887 if (vp->v_vflag & VV_TEXT) 2888 strcat(buf, "|VV_TEXT"); 2889 if (vp->v_vflag & VV_SYSTEM) 2890 strcat(buf, "|VV_SYSTEM"); 2891 if (vp->v_iflag & VI_XLOCK) 2892 strcat(buf, "|VI_XLOCK"); 2893 if (vp->v_iflag & VI_XWANT) 2894 strcat(buf, "|VI_XWANT"); 2895 if (vp->v_iflag & VI_BWAIT) 2896 strcat(buf, "|VI_BWAIT"); 2897 if (vp->v_iflag & VI_DOOMED) 2898 strcat(buf, "|VI_DOOMED"); 2899 if (vp->v_iflag & VI_FREE) 2900 strcat(buf, "|VI_FREE"); 2901 if (vp->v_vflag & VV_OBJBUF) 2902 strcat(buf, "|VV_OBJBUF"); 2903 if (buf[0] != '\0') 2904 printf(" flags (%s),", &buf[1]); 2905 lockmgr_printinfo(vp->v_vnlock); 2906 printf("\n"); 2907 if (vp->v_data != NULL) 2908 VOP_PRINT(vp); 2909 } 2910 2911 #ifdef DDB 2912 #include <ddb/ddb.h> 2913 /* 2914 * List all of the locked vnodes in the system. 2915 * Called when debugging the kernel. 2916 */ 2917 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2918 { 2919 struct mount *mp, *nmp; 2920 struct vnode *vp; 2921 2922 /* 2923 * Note: because this is DDB, we can't obey the locking semantics 2924 * for these structures, which means we could catch an inconsistent 2925 * state and dereference a nasty pointer. Not much to be done 2926 * about that. 2927 */ 2928 printf("Locked vnodes\n"); 2929 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2930 nmp = TAILQ_NEXT(mp, mnt_list); 2931 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2932 if (VOP_ISLOCKED(vp, NULL)) 2933 vprint(NULL, vp); 2934 } 2935 nmp = TAILQ_NEXT(mp, mnt_list); 2936 } 2937 } 2938 #endif 2939 2940 /* 2941 * Fill in a struct xvfsconf based on a struct vfsconf. 2942 */ 2943 static void 2944 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2945 { 2946 2947 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2948 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2949 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2950 xvfsp->vfc_flags = vfsp->vfc_flags; 2951 /* 2952 * These are unused in userland, we keep them 2953 * to not break binary compatibility. 2954 */ 2955 xvfsp->vfc_vfsops = NULL; 2956 xvfsp->vfc_next = NULL; 2957 } 2958 2959 static int 2960 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2961 { 2962 struct vfsconf *vfsp; 2963 struct xvfsconf *xvfsp; 2964 int cnt, error, i; 2965 2966 cnt = 0; 2967 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 2968 cnt++; 2969 xvfsp = malloc(sizeof(struct xvfsconf) * cnt, M_TEMP, M_WAITOK); 2970 /* 2971 * Handle the race that we will have here when struct vfsconf 2972 * will be locked down by using both cnt and checking vfc_next 2973 * against NULL to determine the end of the loop. The race will 2974 * happen because we will have to unlock before calling malloc(). 2975 * We are protected by Giant for now. 2976 */ 2977 i = 0; 2978 for (vfsp = vfsconf; vfsp != NULL && i < cnt; vfsp = vfsp->vfc_next) { 2979 vfsconf2x(vfsp, xvfsp + i); 2980 i++; 2981 } 2982 error = SYSCTL_OUT(req, xvfsp, sizeof(struct xvfsconf) * i); 2983 free(xvfsp, M_TEMP); 2984 return (error); 2985 } 2986 2987 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2988 "S,xvfsconf", "List of all configured filesystems"); 2989 2990 /* 2991 * Top level filesystem related information gathering. 2992 */ 2993 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2994 2995 static int 2996 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2997 { 2998 int *name = (int *)arg1 - 1; /* XXX */ 2999 u_int namelen = arg2 + 1; /* XXX */ 3000 struct vfsconf *vfsp; 3001 struct xvfsconf xvfsp; 3002 3003 printf("WARNING: userland calling deprecated sysctl, " 3004 "please rebuild world\n"); 3005 3006 #if 1 || defined(COMPAT_PRELITE2) 3007 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3008 if (namelen == 1) 3009 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3010 #endif 3011 3012 switch (name[1]) { 3013 case VFS_MAXTYPENUM: 3014 if (namelen != 2) 3015 return (ENOTDIR); 3016 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3017 case VFS_CONF: 3018 if (namelen != 3) 3019 return (ENOTDIR); /* overloaded */ 3020 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 3021 if (vfsp->vfc_typenum == name[2]) 3022 break; 3023 if (vfsp == NULL) 3024 return (EOPNOTSUPP); 3025 vfsconf2x(vfsp, &xvfsp); 3026 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3027 } 3028 return (EOPNOTSUPP); 3029 } 3030 3031 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 3032 "Generic filesystem"); 3033 3034 #if 1 || defined(COMPAT_PRELITE2) 3035 3036 static int 3037 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3038 { 3039 int error; 3040 struct vfsconf *vfsp; 3041 struct ovfsconf ovfs; 3042 3043 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 3044 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3045 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3046 ovfs.vfc_index = vfsp->vfc_typenum; 3047 ovfs.vfc_refcount = vfsp->vfc_refcount; 3048 ovfs.vfc_flags = vfsp->vfc_flags; 3049 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3050 if (error) 3051 return error; 3052 } 3053 return 0; 3054 } 3055 3056 #endif /* 1 || COMPAT_PRELITE2 */ 3057 3058 #define KINFO_VNODESLOP 10 3059 #ifdef notyet 3060 /* 3061 * Dump vnode list (via sysctl). 3062 */ 3063 /* ARGSUSED */ 3064 static int 3065 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3066 { 3067 struct xvnode *xvn; 3068 struct thread *td = req->td; 3069 struct mount *mp; 3070 struct vnode *vp; 3071 int error, len, n; 3072 3073 /* 3074 * Stale numvnodes access is not fatal here. 3075 */ 3076 req->lock = 0; 3077 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3078 if (!req->oldptr) 3079 /* Make an estimate */ 3080 return (SYSCTL_OUT(req, 0, len)); 3081 3082 sysctl_wire_old_buffer(req, 0); 3083 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3084 n = 0; 3085 mtx_lock(&mountlist_mtx); 3086 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3087 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 3088 continue; 3089 mtx_lock(&mntvnode_mtx); 3090 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3091 if (n == len) 3092 break; 3093 vref(vp); 3094 xvn[n].xv_size = sizeof *xvn; 3095 xvn[n].xv_vnode = vp; 3096 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3097 XV_COPY(usecount); 3098 XV_COPY(writecount); 3099 XV_COPY(holdcnt); 3100 XV_COPY(id); 3101 XV_COPY(mount); 3102 XV_COPY(numoutput); 3103 XV_COPY(type); 3104 #undef XV_COPY 3105 xvn[n].xv_flag = vp->v_vflag; 3106 3107 switch (vp->v_type) { 3108 case VREG: 3109 case VDIR: 3110 case VLNK: 3111 xvn[n].xv_dev = vp->v_cachedfs; 3112 xvn[n].xv_ino = vp->v_cachedid; 3113 break; 3114 case VBLK: 3115 case VCHR: 3116 if (vp->v_rdev == NULL) { 3117 vrele(vp); 3118 continue; 3119 } 3120 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3121 break; 3122 case VSOCK: 3123 xvn[n].xv_socket = vp->v_socket; 3124 break; 3125 case VFIFO: 3126 xvn[n].xv_fifo = vp->v_fifoinfo; 3127 break; 3128 case VNON: 3129 case VBAD: 3130 default: 3131 /* shouldn't happen? */ 3132 vrele(vp); 3133 continue; 3134 } 3135 vrele(vp); 3136 ++n; 3137 } 3138 mtx_unlock(&mntvnode_mtx); 3139 mtx_lock(&mountlist_mtx); 3140 vfs_unbusy(mp, td); 3141 if (n == len) 3142 break; 3143 } 3144 mtx_unlock(&mountlist_mtx); 3145 3146 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3147 free(xvn, M_TEMP); 3148 return (error); 3149 } 3150 3151 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 3152 0, 0, sysctl_vnode, "S,xvnode", ""); 3153 #endif 3154 3155 /* 3156 * Check to see if a filesystem is mounted on a block device. 3157 */ 3158 int 3159 vfs_mountedon(vp) 3160 struct vnode *vp; 3161 { 3162 3163 if (vp->v_rdev->si_mountpoint != NULL) 3164 return (EBUSY); 3165 return (0); 3166 } 3167 3168 /* 3169 * Unmount all filesystems. The list is traversed in reverse order 3170 * of mounting to avoid dependencies. 3171 */ 3172 void 3173 vfs_unmountall() 3174 { 3175 struct mount *mp; 3176 struct thread *td; 3177 int error; 3178 3179 if (curthread != NULL) 3180 td = curthread; 3181 else 3182 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 3183 /* 3184 * Since this only runs when rebooting, it is not interlocked. 3185 */ 3186 while(!TAILQ_EMPTY(&mountlist)) { 3187 mp = TAILQ_LAST(&mountlist, mntlist); 3188 error = dounmount(mp, MNT_FORCE, td); 3189 if (error) { 3190 TAILQ_REMOVE(&mountlist, mp, mnt_list); 3191 printf("unmount of %s failed (", 3192 mp->mnt_stat.f_mntonname); 3193 if (error == EBUSY) 3194 printf("BUSY)\n"); 3195 else 3196 printf("%d)\n", error); 3197 } else { 3198 /* The unmount has removed mp from the mountlist */ 3199 } 3200 } 3201 } 3202 3203 /* 3204 * perform msync on all vnodes under a mount point 3205 * the mount point must be locked. 3206 */ 3207 void 3208 vfs_msync(struct mount *mp, int flags) 3209 { 3210 struct vnode *vp, *nvp; 3211 struct vm_object *obj; 3212 int tries; 3213 3214 GIANT_REQUIRED; 3215 3216 tries = 5; 3217 mtx_lock(&mntvnode_mtx); 3218 loop: 3219 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 3220 if (vp->v_mount != mp) { 3221 if (--tries > 0) 3222 goto loop; 3223 break; 3224 } 3225 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 3226 3227 VI_LOCK(vp); 3228 if (vp->v_iflag & VI_XLOCK) { /* XXX: what if MNT_WAIT? */ 3229 VI_UNLOCK(vp); 3230 continue; 3231 } 3232 3233 if ((vp->v_iflag & VI_OBJDIRTY) && 3234 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 3235 mtx_unlock(&mntvnode_mtx); 3236 if (!vget(vp, 3237 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3238 curthread)) { 3239 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3240 vput(vp); 3241 mtx_lock(&mntvnode_mtx); 3242 continue; 3243 } 3244 3245 if (VOP_GETVOBJECT(vp, &obj) == 0) { 3246 VM_OBJECT_LOCK(obj); 3247 vm_object_page_clean(obj, 0, 0, 3248 flags == MNT_WAIT ? 3249 OBJPC_SYNC : OBJPC_NOSYNC); 3250 VM_OBJECT_UNLOCK(obj); 3251 } 3252 vput(vp); 3253 } 3254 mtx_lock(&mntvnode_mtx); 3255 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3256 if (--tries > 0) 3257 goto loop; 3258 break; 3259 } 3260 } else 3261 VI_UNLOCK(vp); 3262 } 3263 mtx_unlock(&mntvnode_mtx); 3264 } 3265 3266 /* 3267 * Create the VM object needed for VMIO and mmap support. This 3268 * is done for all VREG files in the system. Some filesystems might 3269 * afford the additional metadata buffering capability of the 3270 * VMIO code by making the device node be VMIO mode also. 3271 * 3272 * vp must be locked when vfs_object_create is called. 3273 */ 3274 int 3275 vfs_object_create(vp, td, cred) 3276 struct vnode *vp; 3277 struct thread *td; 3278 struct ucred *cred; 3279 { 3280 GIANT_REQUIRED; 3281 return (VOP_CREATEVOBJECT(vp, cred, td)); 3282 } 3283 3284 /* 3285 * Mark a vnode as free, putting it up for recycling. 3286 */ 3287 void 3288 vfree(vp) 3289 struct vnode *vp; 3290 { 3291 int s; 3292 3293 ASSERT_VI_LOCKED(vp, "vfree"); 3294 s = splbio(); 3295 mtx_lock(&vnode_free_list_mtx); 3296 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3297 if (vp->v_iflag & VI_AGE) { 3298 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3299 } else { 3300 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3301 } 3302 freevnodes++; 3303 mtx_unlock(&vnode_free_list_mtx); 3304 vp->v_iflag &= ~VI_AGE; 3305 vp->v_iflag |= VI_FREE; 3306 splx(s); 3307 } 3308 3309 /* 3310 * Opposite of vfree() - mark a vnode as in use. 3311 */ 3312 void 3313 vbusy(vp) 3314 struct vnode *vp; 3315 { 3316 int s; 3317 3318 s = splbio(); 3319 ASSERT_VI_LOCKED(vp, "vbusy"); 3320 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3321 3322 mtx_lock(&vnode_free_list_mtx); 3323 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3324 freevnodes--; 3325 mtx_unlock(&vnode_free_list_mtx); 3326 3327 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3328 splx(s); 3329 } 3330 3331 /* 3332 * Record a process's interest in events which might happen to 3333 * a vnode. Because poll uses the historic select-style interface 3334 * internally, this routine serves as both the ``check for any 3335 * pending events'' and the ``record my interest in future events'' 3336 * functions. (These are done together, while the lock is held, 3337 * to avoid race conditions.) 3338 */ 3339 int 3340 vn_pollrecord(vp, td, events) 3341 struct vnode *vp; 3342 struct thread *td; 3343 short events; 3344 { 3345 3346 if (vp->v_pollinfo == NULL) 3347 v_addpollinfo(vp); 3348 mtx_lock(&vp->v_pollinfo->vpi_lock); 3349 if (vp->v_pollinfo->vpi_revents & events) { 3350 /* 3351 * This leaves events we are not interested 3352 * in available for the other process which 3353 * which presumably had requested them 3354 * (otherwise they would never have been 3355 * recorded). 3356 */ 3357 events &= vp->v_pollinfo->vpi_revents; 3358 vp->v_pollinfo->vpi_revents &= ~events; 3359 3360 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3361 return events; 3362 } 3363 vp->v_pollinfo->vpi_events |= events; 3364 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3365 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3366 return 0; 3367 } 3368 3369 /* 3370 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3371 * it is possible for us to miss an event due to race conditions, but 3372 * that condition is expected to be rare, so for the moment it is the 3373 * preferred interface. 3374 */ 3375 void 3376 vn_pollevent(vp, events) 3377 struct vnode *vp; 3378 short events; 3379 { 3380 3381 if (vp->v_pollinfo == NULL) 3382 v_addpollinfo(vp); 3383 mtx_lock(&vp->v_pollinfo->vpi_lock); 3384 if (vp->v_pollinfo->vpi_events & events) { 3385 /* 3386 * We clear vpi_events so that we don't 3387 * call selwakeup() twice if two events are 3388 * posted before the polling process(es) is 3389 * awakened. This also ensures that we take at 3390 * most one selwakeup() if the polling process 3391 * is no longer interested. However, it does 3392 * mean that only one event can be noticed at 3393 * a time. (Perhaps we should only clear those 3394 * event bits which we note?) XXX 3395 */ 3396 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3397 vp->v_pollinfo->vpi_revents |= events; 3398 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3399 } 3400 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3401 } 3402 3403 /* 3404 * Wake up anyone polling on vp because it is being revoked. 3405 * This depends on dead_poll() returning POLLHUP for correct 3406 * behavior. 3407 */ 3408 void 3409 vn_pollgone(vp) 3410 struct vnode *vp; 3411 { 3412 3413 mtx_lock(&vp->v_pollinfo->vpi_lock); 3414 VN_KNOTE(vp, NOTE_REVOKE); 3415 if (vp->v_pollinfo->vpi_events) { 3416 vp->v_pollinfo->vpi_events = 0; 3417 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3418 } 3419 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3420 } 3421 3422 3423 3424 /* 3425 * Routine to create and manage a filesystem syncer vnode. 3426 */ 3427 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3428 static int sync_fsync(struct vop_fsync_args *); 3429 static int sync_inactive(struct vop_inactive_args *); 3430 static int sync_reclaim(struct vop_reclaim_args *); 3431 3432 static vop_t **sync_vnodeop_p; 3433 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3434 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3435 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3436 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3437 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3438 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3439 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3440 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3441 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3442 { NULL, NULL } 3443 }; 3444 static struct vnodeopv_desc sync_vnodeop_opv_desc = 3445 { &sync_vnodeop_p, sync_vnodeop_entries }; 3446 3447 VNODEOP_SET(sync_vnodeop_opv_desc); 3448 3449 /* 3450 * Create a new filesystem syncer vnode for the specified mount point. 3451 */ 3452 int 3453 vfs_allocate_syncvnode(mp) 3454 struct mount *mp; 3455 { 3456 struct vnode *vp; 3457 static long start, incr, next; 3458 int error; 3459 3460 /* Allocate a new vnode */ 3461 if ((error = getnewvnode("syncer", mp, sync_vnodeop_p, &vp)) != 0) { 3462 mp->mnt_syncer = NULL; 3463 return (error); 3464 } 3465 vp->v_type = VNON; 3466 /* 3467 * Place the vnode onto the syncer worklist. We attempt to 3468 * scatter them about on the list so that they will go off 3469 * at evenly distributed times even if all the filesystems 3470 * are mounted at once. 3471 */ 3472 next += incr; 3473 if (next == 0 || next > syncer_maxdelay) { 3474 start /= 2; 3475 incr /= 2; 3476 if (start == 0) { 3477 start = syncer_maxdelay / 2; 3478 incr = syncer_maxdelay; 3479 } 3480 next = start; 3481 } 3482 VI_LOCK(vp); 3483 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 3484 VI_UNLOCK(vp); 3485 mp->mnt_syncer = vp; 3486 return (0); 3487 } 3488 3489 /* 3490 * Do a lazy sync of the filesystem. 3491 */ 3492 static int 3493 sync_fsync(ap) 3494 struct vop_fsync_args /* { 3495 struct vnode *a_vp; 3496 struct ucred *a_cred; 3497 int a_waitfor; 3498 struct thread *a_td; 3499 } */ *ap; 3500 { 3501 struct vnode *syncvp = ap->a_vp; 3502 struct mount *mp = syncvp->v_mount; 3503 struct thread *td = ap->a_td; 3504 int error, asyncflag; 3505 3506 /* 3507 * We only need to do something if this is a lazy evaluation. 3508 */ 3509 if (ap->a_waitfor != MNT_LAZY) 3510 return (0); 3511 3512 /* 3513 * Move ourselves to the back of the sync list. 3514 */ 3515 VI_LOCK(syncvp); 3516 vn_syncer_add_to_worklist(syncvp, syncdelay); 3517 VI_UNLOCK(syncvp); 3518 3519 /* 3520 * Walk the list of vnodes pushing all that are dirty and 3521 * not already on the sync list. 3522 */ 3523 mtx_lock(&mountlist_mtx); 3524 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3525 mtx_unlock(&mountlist_mtx); 3526 return (0); 3527 } 3528 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3529 vfs_unbusy(mp, td); 3530 return (0); 3531 } 3532 asyncflag = mp->mnt_flag & MNT_ASYNC; 3533 mp->mnt_flag &= ~MNT_ASYNC; 3534 vfs_msync(mp, MNT_NOWAIT); 3535 error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3536 if (asyncflag) 3537 mp->mnt_flag |= MNT_ASYNC; 3538 vn_finished_write(mp); 3539 vfs_unbusy(mp, td); 3540 return (error); 3541 } 3542 3543 /* 3544 * The syncer vnode is no referenced. 3545 */ 3546 static int 3547 sync_inactive(ap) 3548 struct vop_inactive_args /* { 3549 struct vnode *a_vp; 3550 struct thread *a_td; 3551 } */ *ap; 3552 { 3553 3554 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3555 vgone(ap->a_vp); 3556 return (0); 3557 } 3558 3559 /* 3560 * The syncer vnode is no longer needed and is being decommissioned. 3561 * 3562 * Modifications to the worklist must be protected at splbio(). 3563 */ 3564 static int 3565 sync_reclaim(ap) 3566 struct vop_reclaim_args /* { 3567 struct vnode *a_vp; 3568 } */ *ap; 3569 { 3570 struct vnode *vp = ap->a_vp; 3571 int s; 3572 3573 s = splbio(); 3574 vp->v_mount->mnt_syncer = NULL; 3575 VI_LOCK(vp); 3576 if (vp->v_iflag & VI_ONWORKLST) { 3577 mtx_lock(&sync_mtx); 3578 LIST_REMOVE(vp, v_synclist); 3579 mtx_unlock(&sync_mtx); 3580 vp->v_iflag &= ~VI_ONWORKLST; 3581 } 3582 VI_UNLOCK(vp); 3583 splx(s); 3584 3585 return (0); 3586 } 3587 3588 /* 3589 * extract the dev_t from a VCHR 3590 */ 3591 dev_t 3592 vn_todev(vp) 3593 struct vnode *vp; 3594 { 3595 if (vp->v_type != VCHR) 3596 return (NODEV); 3597 return (vp->v_rdev); 3598 } 3599 3600 /* 3601 * Check if vnode represents a disk device 3602 */ 3603 int 3604 vn_isdisk(vp, errp) 3605 struct vnode *vp; 3606 int *errp; 3607 { 3608 struct cdevsw *cdevsw; 3609 3610 if (vp->v_type != VCHR) { 3611 if (errp != NULL) 3612 *errp = ENOTBLK; 3613 return (0); 3614 } 3615 if (vp->v_rdev == NULL) { 3616 if (errp != NULL) 3617 *errp = ENXIO; 3618 return (0); 3619 } 3620 cdevsw = devsw(vp->v_rdev); 3621 if (cdevsw == NULL) { 3622 if (errp != NULL) 3623 *errp = ENXIO; 3624 return (0); 3625 } 3626 if (!(cdevsw->d_flags & D_DISK)) { 3627 if (errp != NULL) 3628 *errp = ENOTBLK; 3629 return (0); 3630 } 3631 if (errp != NULL) 3632 *errp = 0; 3633 return (1); 3634 } 3635 3636 /* 3637 * Free data allocated by namei(); see namei(9) for details. 3638 */ 3639 void 3640 NDFREE(ndp, flags) 3641 struct nameidata *ndp; 3642 const u_int flags; 3643 { 3644 if (!(flags & NDF_NO_FREE_PNBUF) && 3645 (ndp->ni_cnd.cn_flags & HASBUF)) { 3646 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3647 ndp->ni_cnd.cn_flags &= ~HASBUF; 3648 } 3649 if (!(flags & NDF_NO_DVP_UNLOCK) && 3650 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3651 ndp->ni_dvp != ndp->ni_vp) 3652 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3653 if (!(flags & NDF_NO_DVP_RELE) && 3654 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3655 vrele(ndp->ni_dvp); 3656 ndp->ni_dvp = NULL; 3657 } 3658 if (!(flags & NDF_NO_VP_UNLOCK) && 3659 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3660 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3661 if (!(flags & NDF_NO_VP_RELE) && 3662 ndp->ni_vp) { 3663 vrele(ndp->ni_vp); 3664 ndp->ni_vp = NULL; 3665 } 3666 if (!(flags & NDF_NO_STARTDIR_RELE) && 3667 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3668 vrele(ndp->ni_startdir); 3669 ndp->ni_startdir = NULL; 3670 } 3671 } 3672 3673 /* 3674 * Common filesystem object access control check routine. Accepts a 3675 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3676 * and optional call-by-reference privused argument allowing vaccess() 3677 * to indicate to the caller whether privilege was used to satisfy the 3678 * request (obsoleted). Returns 0 on success, or an errno on failure. 3679 */ 3680 int 3681 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3682 enum vtype type; 3683 mode_t file_mode; 3684 uid_t file_uid; 3685 gid_t file_gid; 3686 mode_t acc_mode; 3687 struct ucred *cred; 3688 int *privused; 3689 { 3690 mode_t dac_granted; 3691 #ifdef CAPABILITIES 3692 mode_t cap_granted; 3693 #endif 3694 3695 /* 3696 * Look for a normal, non-privileged way to access the file/directory 3697 * as requested. If it exists, go with that. 3698 */ 3699 3700 if (privused != NULL) 3701 *privused = 0; 3702 3703 dac_granted = 0; 3704 3705 /* Check the owner. */ 3706 if (cred->cr_uid == file_uid) { 3707 dac_granted |= VADMIN; 3708 if (file_mode & S_IXUSR) 3709 dac_granted |= VEXEC; 3710 if (file_mode & S_IRUSR) 3711 dac_granted |= VREAD; 3712 if (file_mode & S_IWUSR) 3713 dac_granted |= (VWRITE | VAPPEND); 3714 3715 if ((acc_mode & dac_granted) == acc_mode) 3716 return (0); 3717 3718 goto privcheck; 3719 } 3720 3721 /* Otherwise, check the groups (first match) */ 3722 if (groupmember(file_gid, cred)) { 3723 if (file_mode & S_IXGRP) 3724 dac_granted |= VEXEC; 3725 if (file_mode & S_IRGRP) 3726 dac_granted |= VREAD; 3727 if (file_mode & S_IWGRP) 3728 dac_granted |= (VWRITE | VAPPEND); 3729 3730 if ((acc_mode & dac_granted) == acc_mode) 3731 return (0); 3732 3733 goto privcheck; 3734 } 3735 3736 /* Otherwise, check everyone else. */ 3737 if (file_mode & S_IXOTH) 3738 dac_granted |= VEXEC; 3739 if (file_mode & S_IROTH) 3740 dac_granted |= VREAD; 3741 if (file_mode & S_IWOTH) 3742 dac_granted |= (VWRITE | VAPPEND); 3743 if ((acc_mode & dac_granted) == acc_mode) 3744 return (0); 3745 3746 privcheck: 3747 if (!suser_cred(cred, PRISON_ROOT)) { 3748 /* XXX audit: privilege used */ 3749 if (privused != NULL) 3750 *privused = 1; 3751 return (0); 3752 } 3753 3754 #ifdef CAPABILITIES 3755 /* 3756 * Build a capability mask to determine if the set of capabilities 3757 * satisfies the requirements when combined with the granted mask 3758 * from above. 3759 * For each capability, if the capability is required, bitwise 3760 * or the request type onto the cap_granted mask. 3761 */ 3762 cap_granted = 0; 3763 3764 if (type == VDIR) { 3765 /* 3766 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3767 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3768 */ 3769 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3770 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3771 cap_granted |= VEXEC; 3772 } else { 3773 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3774 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3775 cap_granted |= VEXEC; 3776 } 3777 3778 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3779 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3780 cap_granted |= VREAD; 3781 3782 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3783 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3784 cap_granted |= (VWRITE | VAPPEND); 3785 3786 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3787 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3788 cap_granted |= VADMIN; 3789 3790 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3791 /* XXX audit: privilege used */ 3792 if (privused != NULL) 3793 *privused = 1; 3794 return (0); 3795 } 3796 #endif 3797 3798 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3799 } 3800 3801 /* 3802 * Credential check based on process requesting service, and per-attribute 3803 * permissions. 3804 */ 3805 int 3806 extattr_check_cred(struct vnode *vp, int attrnamespace, 3807 struct ucred *cred, struct thread *td, int access) 3808 { 3809 3810 /* 3811 * Kernel-invoked always succeeds. 3812 */ 3813 if (cred == NOCRED) 3814 return (0); 3815 3816 /* 3817 * Do not allow privileged processes in jail to directly 3818 * manipulate system attributes. 3819 * 3820 * XXX What capability should apply here? 3821 * Probably CAP_SYS_SETFFLAG. 3822 */ 3823 switch (attrnamespace) { 3824 case EXTATTR_NAMESPACE_SYSTEM: 3825 /* Potentially should be: return (EPERM); */ 3826 return (suser_cred(cred, 0)); 3827 case EXTATTR_NAMESPACE_USER: 3828 return (VOP_ACCESS(vp, access, cred, td)); 3829 default: 3830 return (EPERM); 3831 } 3832 } 3833