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 VI_UNLOCK(vp); 2224 } 2225 VI_LOCK(vp); 2226 if (VSHOULDFREE(vp)) 2227 vfree(vp); 2228 else 2229 vlruvp(vp); 2230 VI_UNLOCK(vp); 2231 2232 } else { 2233 #ifdef DIAGNOSTIC 2234 vprint("vrele: negative ref count", vp); 2235 #endif 2236 VI_UNLOCK(vp); 2237 panic("vrele: negative ref cnt"); 2238 } 2239 } 2240 2241 /* 2242 * Release an already locked vnode. This give the same effects as 2243 * unlock+vrele(), but takes less time and avoids releasing and 2244 * re-aquiring the lock (as vrele() aquires the lock internally.) 2245 */ 2246 void 2247 vput(vp) 2248 struct vnode *vp; 2249 { 2250 struct thread *td = curthread; /* XXX */ 2251 2252 GIANT_REQUIRED; 2253 2254 KASSERT(vp != NULL, ("vput: null vp")); 2255 VI_LOCK(vp); 2256 /* Skip this v_writecount check if we're going to panic below. */ 2257 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2258 ("vput: missed vn_close")); 2259 2260 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2261 vp->v_usecount == 1)) { 2262 v_incr_usecount(vp, -1); 2263 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2264 return; 2265 } 2266 2267 if (vp->v_usecount == 1) { 2268 v_incr_usecount(vp, -1); 2269 /* 2270 * We must call VOP_INACTIVE with the node locked, so 2271 * we just need to release the vnode mutex. Mark as 2272 * as VI_DOINGINACT to avoid recursion. 2273 */ 2274 vp->v_iflag |= VI_DOINGINACT; 2275 VI_UNLOCK(vp); 2276 VOP_INACTIVE(vp, td); 2277 VI_LOCK(vp); 2278 KASSERT(vp->v_iflag & VI_DOINGINACT, 2279 ("vput: lost VI_DOINGINACT")); 2280 vp->v_iflag &= ~VI_DOINGINACT; 2281 if (VSHOULDFREE(vp)) 2282 vfree(vp); 2283 else 2284 vlruvp(vp); 2285 VI_UNLOCK(vp); 2286 2287 } else { 2288 #ifdef DIAGNOSTIC 2289 vprint("vput: negative ref count", vp); 2290 #endif 2291 panic("vput: negative ref cnt"); 2292 } 2293 } 2294 2295 /* 2296 * Somebody doesn't want the vnode recycled. 2297 */ 2298 void 2299 vhold(struct vnode *vp) 2300 { 2301 VI_LOCK(vp); 2302 vholdl(vp); 2303 VI_UNLOCK(vp); 2304 } 2305 2306 void 2307 vholdl(vp) 2308 register struct vnode *vp; 2309 { 2310 int s; 2311 2312 s = splbio(); 2313 vp->v_holdcnt++; 2314 if (VSHOULDBUSY(vp)) 2315 vbusy(vp); 2316 splx(s); 2317 } 2318 2319 /* 2320 * Note that there is one less who cares about this vnode. vdrop() is the 2321 * opposite of vhold(). 2322 */ 2323 void 2324 vdrop(struct vnode *vp) 2325 { 2326 VI_LOCK(vp); 2327 vdropl(vp); 2328 VI_UNLOCK(vp); 2329 } 2330 2331 void 2332 vdropl(vp) 2333 register struct vnode *vp; 2334 { 2335 int s; 2336 2337 s = splbio(); 2338 if (vp->v_holdcnt <= 0) 2339 panic("vdrop: holdcnt"); 2340 vp->v_holdcnt--; 2341 if (VSHOULDFREE(vp)) 2342 vfree(vp); 2343 else 2344 vlruvp(vp); 2345 splx(s); 2346 } 2347 2348 /* 2349 * Remove any vnodes in the vnode table belonging to mount point mp. 2350 * 2351 * If FORCECLOSE is not specified, there should not be any active ones, 2352 * return error if any are found (nb: this is a user error, not a 2353 * system error). If FORCECLOSE is specified, detach any active vnodes 2354 * that are found. 2355 * 2356 * If WRITECLOSE is set, only flush out regular file vnodes open for 2357 * writing. 2358 * 2359 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2360 * 2361 * `rootrefs' specifies the base reference count for the root vnode 2362 * of this filesystem. The root vnode is considered busy if its 2363 * v_usecount exceeds this value. On a successful return, vflush() 2364 * will call vrele() on the root vnode exactly rootrefs times. 2365 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2366 * be zero. 2367 */ 2368 #ifdef DIAGNOSTIC 2369 static int busyprt = 0; /* print out busy vnodes */ 2370 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2371 #endif 2372 2373 int 2374 vflush(mp, rootrefs, flags) 2375 struct mount *mp; 2376 int rootrefs; 2377 int flags; 2378 { 2379 struct thread *td = curthread; /* XXX */ 2380 struct vnode *vp, *nvp, *rootvp = NULL; 2381 struct vattr vattr; 2382 int busy = 0, error; 2383 2384 if (rootrefs > 0) { 2385 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2386 ("vflush: bad args")); 2387 /* 2388 * Get the filesystem root vnode. We can vput() it 2389 * immediately, since with rootrefs > 0, it won't go away. 2390 */ 2391 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 2392 return (error); 2393 vput(rootvp); 2394 2395 } 2396 mtx_lock(&mntvnode_mtx); 2397 loop: 2398 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 2399 /* 2400 * Make sure this vnode wasn't reclaimed in getnewvnode(). 2401 * Start over if it has (it won't be on the list anymore). 2402 */ 2403 if (vp->v_mount != mp) 2404 goto loop; 2405 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2406 2407 VI_LOCK(vp); 2408 mtx_unlock(&mntvnode_mtx); 2409 vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY, td); 2410 /* 2411 * This vnode could have been reclaimed while we were 2412 * waiting for the lock since we are not holding a 2413 * reference. 2414 * Start over if the vnode was reclaimed. 2415 */ 2416 if (vp->v_mount != mp) { 2417 VOP_UNLOCK(vp, 0, td); 2418 mtx_lock(&mntvnode_mtx); 2419 goto loop; 2420 } 2421 /* 2422 * Skip over a vnodes marked VV_SYSTEM. 2423 */ 2424 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2425 VOP_UNLOCK(vp, 0, td); 2426 mtx_lock(&mntvnode_mtx); 2427 continue; 2428 } 2429 /* 2430 * If WRITECLOSE is set, flush out unlinked but still open 2431 * files (even if open only for reading) and regular file 2432 * vnodes open for writing. 2433 */ 2434 if (flags & WRITECLOSE) { 2435 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2436 VI_LOCK(vp); 2437 2438 if ((vp->v_type == VNON || 2439 (error == 0 && vattr.va_nlink > 0)) && 2440 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2441 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2442 mtx_lock(&mntvnode_mtx); 2443 continue; 2444 } 2445 } else 2446 VI_LOCK(vp); 2447 2448 VOP_UNLOCK(vp, 0, td); 2449 2450 /* 2451 * With v_usecount == 0, all we need to do is clear out the 2452 * vnode data structures and we are done. 2453 */ 2454 if (vp->v_usecount == 0) { 2455 vgonel(vp, td); 2456 mtx_lock(&mntvnode_mtx); 2457 continue; 2458 } 2459 2460 /* 2461 * If FORCECLOSE is set, forcibly close the vnode. For block 2462 * or character devices, revert to an anonymous device. For 2463 * all other files, just kill them. 2464 */ 2465 if (flags & FORCECLOSE) { 2466 if (vp->v_type != VCHR) { 2467 vgonel(vp, td); 2468 } else { 2469 vclean(vp, 0, td); 2470 VI_UNLOCK(vp); 2471 vp->v_op = spec_vnodeop_p; 2472 insmntque(vp, (struct mount *) 0); 2473 } 2474 mtx_lock(&mntvnode_mtx); 2475 continue; 2476 } 2477 #ifdef DIAGNOSTIC 2478 if (busyprt) 2479 vprint("vflush: busy vnode", vp); 2480 #endif 2481 VI_UNLOCK(vp); 2482 mtx_lock(&mntvnode_mtx); 2483 busy++; 2484 } 2485 mtx_unlock(&mntvnode_mtx); 2486 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2487 /* 2488 * If just the root vnode is busy, and if its refcount 2489 * is equal to `rootrefs', then go ahead and kill it. 2490 */ 2491 VI_LOCK(rootvp); 2492 KASSERT(busy > 0, ("vflush: not busy")); 2493 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 2494 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2495 vgonel(rootvp, td); 2496 busy = 0; 2497 } else 2498 VI_UNLOCK(rootvp); 2499 } 2500 if (busy) 2501 return (EBUSY); 2502 for (; rootrefs > 0; rootrefs--) 2503 vrele(rootvp); 2504 return (0); 2505 } 2506 2507 /* 2508 * This moves a now (likely recyclable) vnode to the end of the 2509 * mountlist. XXX However, it is temporarily disabled until we 2510 * can clean up ffs_sync() and friends, which have loop restart 2511 * conditions which this code causes to operate O(N^2). 2512 */ 2513 static void 2514 vlruvp(struct vnode *vp) 2515 { 2516 #if 0 2517 struct mount *mp; 2518 2519 if ((mp = vp->v_mount) != NULL) { 2520 mtx_lock(&mntvnode_mtx); 2521 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2522 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2523 mtx_unlock(&mntvnode_mtx); 2524 } 2525 #endif 2526 } 2527 2528 /* 2529 * Disassociate the underlying filesystem from a vnode. 2530 */ 2531 static void 2532 vclean(vp, flags, td) 2533 struct vnode *vp; 2534 int flags; 2535 struct thread *td; 2536 { 2537 int active; 2538 2539 ASSERT_VI_LOCKED(vp, "vclean"); 2540 /* 2541 * Check to see if the vnode is in use. If so we have to reference it 2542 * before we clean it out so that its count cannot fall to zero and 2543 * generate a race against ourselves to recycle it. 2544 */ 2545 if ((active = vp->v_usecount)) 2546 v_incr_usecount(vp, 1); 2547 2548 /* 2549 * Prevent the vnode from being recycled or brought into use while we 2550 * clean it out. 2551 */ 2552 if (vp->v_iflag & VI_XLOCK) 2553 panic("vclean: deadlock"); 2554 vp->v_iflag |= VI_XLOCK; 2555 vp->v_vxproc = curthread; 2556 /* 2557 * Even if the count is zero, the VOP_INACTIVE routine may still 2558 * have the object locked while it cleans it out. The VOP_LOCK 2559 * ensures that the VOP_INACTIVE routine is done with its work. 2560 * For active vnodes, it ensures that no other activity can 2561 * occur while the underlying object is being cleaned out. 2562 */ 2563 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2564 2565 /* 2566 * Clean out any buffers associated with the vnode. 2567 * If the flush fails, just toss the buffers. 2568 */ 2569 if (flags & DOCLOSE) { 2570 struct buf *bp; 2571 VI_LOCK(vp); 2572 bp = TAILQ_FIRST(&vp->v_dirtyblkhd); 2573 VI_UNLOCK(vp); 2574 if (bp != NULL) 2575 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2576 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2577 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2578 } 2579 2580 VOP_DESTROYVOBJECT(vp); 2581 2582 /* 2583 * Any other processes trying to obtain this lock must first 2584 * wait for VXLOCK to clear, then call the new lock operation. 2585 */ 2586 VOP_UNLOCK(vp, 0, td); 2587 2588 /* 2589 * If purging an active vnode, it must be closed and 2590 * deactivated before being reclaimed. Note that the 2591 * VOP_INACTIVE will unlock the vnode. 2592 */ 2593 if (active) { 2594 if (flags & DOCLOSE) 2595 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2596 VI_LOCK(vp); 2597 if ((vp->v_iflag & VI_DOINGINACT) == 0) { 2598 vp->v_iflag |= VI_DOINGINACT; 2599 VI_UNLOCK(vp); 2600 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2601 panic("vclean: cannot relock."); 2602 VOP_INACTIVE(vp, td); 2603 VI_LOCK(vp); 2604 KASSERT(vp->v_iflag & VI_DOINGINACT, 2605 ("vclean: lost VI_DOINGINACT")); 2606 vp->v_iflag &= ~VI_DOINGINACT; 2607 } 2608 VI_UNLOCK(vp); 2609 } 2610 2611 /* 2612 * Reclaim the vnode. 2613 */ 2614 if (VOP_RECLAIM(vp, td)) 2615 panic("vclean: cannot reclaim"); 2616 2617 if (active) { 2618 /* 2619 * Inline copy of vrele() since VOP_INACTIVE 2620 * has already been called. 2621 */ 2622 VI_LOCK(vp); 2623 v_incr_usecount(vp, -1); 2624 if (vp->v_usecount <= 0) { 2625 #ifdef DIAGNOSTIC 2626 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2627 vprint("vclean: bad ref count", vp); 2628 panic("vclean: ref cnt"); 2629 } 2630 #endif 2631 vfree(vp); 2632 } 2633 VI_UNLOCK(vp); 2634 } 2635 2636 cache_purge(vp); 2637 VI_LOCK(vp); 2638 if (VSHOULDFREE(vp)) 2639 vfree(vp); 2640 2641 /* 2642 * Done with purge, reset to the standard lock and 2643 * notify sleepers of the grim news. 2644 */ 2645 vp->v_vnlock = &vp->v_lock; 2646 vp->v_op = dead_vnodeop_p; 2647 if (vp->v_pollinfo != NULL) 2648 vn_pollgone(vp); 2649 vp->v_tag = "none"; 2650 vp->v_iflag &= ~VI_XLOCK; 2651 vp->v_vxproc = NULL; 2652 if (vp->v_iflag & VI_XWANT) { 2653 vp->v_iflag &= ~VI_XWANT; 2654 wakeup(vp); 2655 } 2656 } 2657 2658 /* 2659 * Eliminate all activity associated with the requested vnode 2660 * and with all vnodes aliased to the requested vnode. 2661 */ 2662 int 2663 vop_revoke(ap) 2664 struct vop_revoke_args /* { 2665 struct vnode *a_vp; 2666 int a_flags; 2667 } */ *ap; 2668 { 2669 struct vnode *vp, *vq; 2670 dev_t dev; 2671 2672 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2673 vp = ap->a_vp; 2674 KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); 2675 2676 VI_LOCK(vp); 2677 /* 2678 * If a vgone (or vclean) is already in progress, 2679 * wait until it is done and return. 2680 */ 2681 if (vp->v_iflag & VI_XLOCK) { 2682 vp->v_iflag |= VI_XWANT; 2683 msleep(vp, VI_MTX(vp), PINOD | PDROP, 2684 "vop_revokeall", 0); 2685 return (0); 2686 } 2687 VI_UNLOCK(vp); 2688 dev = vp->v_rdev; 2689 for (;;) { 2690 mtx_lock(&spechash_mtx); 2691 vq = SLIST_FIRST(&dev->si_hlist); 2692 mtx_unlock(&spechash_mtx); 2693 if (!vq) 2694 break; 2695 vgone(vq); 2696 } 2697 return (0); 2698 } 2699 2700 /* 2701 * Recycle an unused vnode to the front of the free list. 2702 * Release the passed interlock if the vnode will be recycled. 2703 */ 2704 int 2705 vrecycle(vp, inter_lkp, td) 2706 struct vnode *vp; 2707 struct mtx *inter_lkp; 2708 struct thread *td; 2709 { 2710 2711 VI_LOCK(vp); 2712 if (vp->v_usecount == 0) { 2713 if (inter_lkp) { 2714 mtx_unlock(inter_lkp); 2715 } 2716 vgonel(vp, td); 2717 return (1); 2718 } 2719 VI_UNLOCK(vp); 2720 return (0); 2721 } 2722 2723 /* 2724 * Eliminate all activity associated with a vnode 2725 * in preparation for reuse. 2726 */ 2727 void 2728 vgone(vp) 2729 register struct vnode *vp; 2730 { 2731 struct thread *td = curthread; /* XXX */ 2732 2733 VI_LOCK(vp); 2734 vgonel(vp, td); 2735 } 2736 2737 /* 2738 * vgone, with the vp interlock held. 2739 */ 2740 void 2741 vgonel(vp, td) 2742 struct vnode *vp; 2743 struct thread *td; 2744 { 2745 int s; 2746 2747 /* 2748 * If a vgone (or vclean) is already in progress, 2749 * wait until it is done and return. 2750 */ 2751 ASSERT_VI_LOCKED(vp, "vgonel"); 2752 if (vp->v_iflag & VI_XLOCK) { 2753 vp->v_iflag |= VI_XWANT; 2754 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); 2755 return; 2756 } 2757 2758 /* 2759 * Clean out the filesystem specific data. 2760 */ 2761 vclean(vp, DOCLOSE, td); 2762 VI_UNLOCK(vp); 2763 2764 /* 2765 * Delete from old mount point vnode list, if on one. 2766 */ 2767 if (vp->v_mount != NULL) 2768 insmntque(vp, (struct mount *)0); 2769 /* 2770 * If special device, remove it from special device alias list 2771 * if it is on one. 2772 */ 2773 if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { 2774 VI_LOCK(vp); 2775 mtx_lock(&spechash_mtx); 2776 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2777 vp->v_rdev->si_usecount -= vp->v_usecount; 2778 mtx_unlock(&spechash_mtx); 2779 VI_UNLOCK(vp); 2780 vp->v_rdev = NULL; 2781 } 2782 2783 /* 2784 * If it is on the freelist and not already at the head, 2785 * move it to the head of the list. The test of the 2786 * VDOOMED flag and the reference count of zero is because 2787 * it will be removed from the free list by getnewvnode, 2788 * but will not have its reference count incremented until 2789 * after calling vgone. If the reference count were 2790 * incremented first, vgone would (incorrectly) try to 2791 * close the previous instance of the underlying object. 2792 */ 2793 VI_LOCK(vp); 2794 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2795 s = splbio(); 2796 mtx_lock(&vnode_free_list_mtx); 2797 if (vp->v_iflag & VI_FREE) { 2798 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2799 } else { 2800 vp->v_iflag |= VI_FREE; 2801 freevnodes++; 2802 } 2803 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2804 mtx_unlock(&vnode_free_list_mtx); 2805 splx(s); 2806 } 2807 2808 vp->v_type = VBAD; 2809 VI_UNLOCK(vp); 2810 } 2811 2812 /* 2813 * Lookup a vnode by device number. 2814 */ 2815 int 2816 vfinddev(dev, type, vpp) 2817 dev_t dev; 2818 enum vtype type; 2819 struct vnode **vpp; 2820 { 2821 struct vnode *vp; 2822 2823 mtx_lock(&spechash_mtx); 2824 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2825 if (type == vp->v_type) { 2826 *vpp = vp; 2827 mtx_unlock(&spechash_mtx); 2828 return (1); 2829 } 2830 } 2831 mtx_unlock(&spechash_mtx); 2832 return (0); 2833 } 2834 2835 /* 2836 * Calculate the total number of references to a special device. 2837 */ 2838 int 2839 vcount(vp) 2840 struct vnode *vp; 2841 { 2842 int count; 2843 2844 mtx_lock(&spechash_mtx); 2845 count = vp->v_rdev->si_usecount; 2846 mtx_unlock(&spechash_mtx); 2847 return (count); 2848 } 2849 2850 /* 2851 * Same as above, but using the dev_t as argument 2852 */ 2853 int 2854 count_dev(dev) 2855 dev_t dev; 2856 { 2857 struct vnode *vp; 2858 2859 vp = SLIST_FIRST(&dev->si_hlist); 2860 if (vp == NULL) 2861 return (0); 2862 return(vcount(vp)); 2863 } 2864 2865 /* 2866 * Print out a description of a vnode. 2867 */ 2868 static char *typename[] = 2869 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2870 2871 void 2872 vprint(label, vp) 2873 char *label; 2874 struct vnode *vp; 2875 { 2876 char buf[96]; 2877 2878 if (label != NULL) 2879 printf("%s: %p: ", label, (void *)vp); 2880 else 2881 printf("%p: ", (void *)vp); 2882 printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", 2883 vp->v_tag, typename[vp->v_type], vp->v_usecount, 2884 vp->v_writecount, vp->v_holdcnt); 2885 buf[0] = '\0'; 2886 if (vp->v_vflag & VV_ROOT) 2887 strcat(buf, "|VV_ROOT"); 2888 if (vp->v_vflag & VV_TEXT) 2889 strcat(buf, "|VV_TEXT"); 2890 if (vp->v_vflag & VV_SYSTEM) 2891 strcat(buf, "|VV_SYSTEM"); 2892 if (vp->v_iflag & VI_XLOCK) 2893 strcat(buf, "|VI_XLOCK"); 2894 if (vp->v_iflag & VI_XWANT) 2895 strcat(buf, "|VI_XWANT"); 2896 if (vp->v_iflag & VI_BWAIT) 2897 strcat(buf, "|VI_BWAIT"); 2898 if (vp->v_iflag & VI_DOOMED) 2899 strcat(buf, "|VI_DOOMED"); 2900 if (vp->v_iflag & VI_FREE) 2901 strcat(buf, "|VI_FREE"); 2902 if (vp->v_vflag & VV_OBJBUF) 2903 strcat(buf, "|VV_OBJBUF"); 2904 if (buf[0] != '\0') 2905 printf(" flags (%s),", &buf[1]); 2906 lockmgr_printinfo(vp->v_vnlock); 2907 printf("\n"); 2908 if (vp->v_data != NULL) 2909 VOP_PRINT(vp); 2910 } 2911 2912 #ifdef DDB 2913 #include <ddb/ddb.h> 2914 /* 2915 * List all of the locked vnodes in the system. 2916 * Called when debugging the kernel. 2917 */ 2918 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2919 { 2920 struct mount *mp, *nmp; 2921 struct vnode *vp; 2922 2923 /* 2924 * Note: because this is DDB, we can't obey the locking semantics 2925 * for these structures, which means we could catch an inconsistent 2926 * state and dereference a nasty pointer. Not much to be done 2927 * about that. 2928 */ 2929 printf("Locked vnodes\n"); 2930 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2931 nmp = TAILQ_NEXT(mp, mnt_list); 2932 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2933 if (VOP_ISLOCKED(vp, NULL)) 2934 vprint(NULL, vp); 2935 } 2936 nmp = TAILQ_NEXT(mp, mnt_list); 2937 } 2938 } 2939 #endif 2940 2941 /* 2942 * Fill in a struct xvfsconf based on a struct vfsconf. 2943 */ 2944 static void 2945 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2946 { 2947 2948 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2949 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2950 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2951 xvfsp->vfc_flags = vfsp->vfc_flags; 2952 /* 2953 * These are unused in userland, we keep them 2954 * to not break binary compatibility. 2955 */ 2956 xvfsp->vfc_vfsops = NULL; 2957 xvfsp->vfc_next = NULL; 2958 } 2959 2960 static int 2961 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2962 { 2963 struct vfsconf *vfsp; 2964 struct xvfsconf *xvfsp; 2965 int cnt, error, i; 2966 2967 cnt = 0; 2968 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 2969 cnt++; 2970 xvfsp = malloc(sizeof(struct xvfsconf) * cnt, M_TEMP, M_WAITOK); 2971 /* 2972 * Handle the race that we will have here when struct vfsconf 2973 * will be locked down by using both cnt and checking vfc_next 2974 * against NULL to determine the end of the loop. The race will 2975 * happen because we will have to unlock before calling malloc(). 2976 * We are protected by Giant for now. 2977 */ 2978 i = 0; 2979 for (vfsp = vfsconf; vfsp != NULL && i < cnt; vfsp = vfsp->vfc_next) { 2980 vfsconf2x(vfsp, xvfsp + i); 2981 i++; 2982 } 2983 error = SYSCTL_OUT(req, xvfsp, sizeof(struct xvfsconf) * i); 2984 free(xvfsp, M_TEMP); 2985 return (error); 2986 } 2987 2988 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2989 "S,xvfsconf", "List of all configured filesystems"); 2990 2991 /* 2992 * Top level filesystem related information gathering. 2993 */ 2994 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2995 2996 static int 2997 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2998 { 2999 int *name = (int *)arg1 - 1; /* XXX */ 3000 u_int namelen = arg2 + 1; /* XXX */ 3001 struct vfsconf *vfsp; 3002 struct xvfsconf xvfsp; 3003 3004 printf("WARNING: userland calling deprecated sysctl, " 3005 "please rebuild world\n"); 3006 3007 #if 1 || defined(COMPAT_PRELITE2) 3008 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3009 if (namelen == 1) 3010 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3011 #endif 3012 3013 switch (name[1]) { 3014 case VFS_MAXTYPENUM: 3015 if (namelen != 2) 3016 return (ENOTDIR); 3017 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3018 case VFS_CONF: 3019 if (namelen != 3) 3020 return (ENOTDIR); /* overloaded */ 3021 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 3022 if (vfsp->vfc_typenum == name[2]) 3023 break; 3024 if (vfsp == NULL) 3025 return (EOPNOTSUPP); 3026 vfsconf2x(vfsp, &xvfsp); 3027 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3028 } 3029 return (EOPNOTSUPP); 3030 } 3031 3032 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 3033 "Generic filesystem"); 3034 3035 #if 1 || defined(COMPAT_PRELITE2) 3036 3037 static int 3038 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3039 { 3040 int error; 3041 struct vfsconf *vfsp; 3042 struct ovfsconf ovfs; 3043 3044 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 3045 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3046 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3047 ovfs.vfc_index = vfsp->vfc_typenum; 3048 ovfs.vfc_refcount = vfsp->vfc_refcount; 3049 ovfs.vfc_flags = vfsp->vfc_flags; 3050 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3051 if (error) 3052 return error; 3053 } 3054 return 0; 3055 } 3056 3057 #endif /* 1 || COMPAT_PRELITE2 */ 3058 3059 #define KINFO_VNODESLOP 10 3060 #ifdef notyet 3061 /* 3062 * Dump vnode list (via sysctl). 3063 */ 3064 /* ARGSUSED */ 3065 static int 3066 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3067 { 3068 struct xvnode *xvn; 3069 struct thread *td = req->td; 3070 struct mount *mp; 3071 struct vnode *vp; 3072 int error, len, n; 3073 3074 /* 3075 * Stale numvnodes access is not fatal here. 3076 */ 3077 req->lock = 0; 3078 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3079 if (!req->oldptr) 3080 /* Make an estimate */ 3081 return (SYSCTL_OUT(req, 0, len)); 3082 3083 sysctl_wire_old_buffer(req, 0); 3084 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3085 n = 0; 3086 mtx_lock(&mountlist_mtx); 3087 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3088 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 3089 continue; 3090 mtx_lock(&mntvnode_mtx); 3091 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3092 if (n == len) 3093 break; 3094 vref(vp); 3095 xvn[n].xv_size = sizeof *xvn; 3096 xvn[n].xv_vnode = vp; 3097 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3098 XV_COPY(usecount); 3099 XV_COPY(writecount); 3100 XV_COPY(holdcnt); 3101 XV_COPY(id); 3102 XV_COPY(mount); 3103 XV_COPY(numoutput); 3104 XV_COPY(type); 3105 #undef XV_COPY 3106 xvn[n].xv_flag = vp->v_vflag; 3107 3108 switch (vp->v_type) { 3109 case VREG: 3110 case VDIR: 3111 case VLNK: 3112 xvn[n].xv_dev = vp->v_cachedfs; 3113 xvn[n].xv_ino = vp->v_cachedid; 3114 break; 3115 case VBLK: 3116 case VCHR: 3117 if (vp->v_rdev == NULL) { 3118 vrele(vp); 3119 continue; 3120 } 3121 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3122 break; 3123 case VSOCK: 3124 xvn[n].xv_socket = vp->v_socket; 3125 break; 3126 case VFIFO: 3127 xvn[n].xv_fifo = vp->v_fifoinfo; 3128 break; 3129 case VNON: 3130 case VBAD: 3131 default: 3132 /* shouldn't happen? */ 3133 vrele(vp); 3134 continue; 3135 } 3136 vrele(vp); 3137 ++n; 3138 } 3139 mtx_unlock(&mntvnode_mtx); 3140 mtx_lock(&mountlist_mtx); 3141 vfs_unbusy(mp, td); 3142 if (n == len) 3143 break; 3144 } 3145 mtx_unlock(&mountlist_mtx); 3146 3147 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3148 free(xvn, M_TEMP); 3149 return (error); 3150 } 3151 3152 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 3153 0, 0, sysctl_vnode, "S,xvnode", ""); 3154 #endif 3155 3156 /* 3157 * Check to see if a filesystem is mounted on a block device. 3158 */ 3159 int 3160 vfs_mountedon(vp) 3161 struct vnode *vp; 3162 { 3163 3164 if (vp->v_rdev->si_mountpoint != NULL) 3165 return (EBUSY); 3166 return (0); 3167 } 3168 3169 /* 3170 * Unmount all filesystems. The list is traversed in reverse order 3171 * of mounting to avoid dependencies. 3172 */ 3173 void 3174 vfs_unmountall() 3175 { 3176 struct mount *mp; 3177 struct thread *td; 3178 int error; 3179 3180 if (curthread != NULL) 3181 td = curthread; 3182 else 3183 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 3184 /* 3185 * Since this only runs when rebooting, it is not interlocked. 3186 */ 3187 while(!TAILQ_EMPTY(&mountlist)) { 3188 mp = TAILQ_LAST(&mountlist, mntlist); 3189 error = dounmount(mp, MNT_FORCE, td); 3190 if (error) { 3191 TAILQ_REMOVE(&mountlist, mp, mnt_list); 3192 printf("unmount of %s failed (", 3193 mp->mnt_stat.f_mntonname); 3194 if (error == EBUSY) 3195 printf("BUSY)\n"); 3196 else 3197 printf("%d)\n", error); 3198 } else { 3199 /* The unmount has removed mp from the mountlist */ 3200 } 3201 } 3202 } 3203 3204 /* 3205 * perform msync on all vnodes under a mount point 3206 * the mount point must be locked. 3207 */ 3208 void 3209 vfs_msync(struct mount *mp, int flags) 3210 { 3211 struct vnode *vp, *nvp; 3212 struct vm_object *obj; 3213 int tries; 3214 3215 GIANT_REQUIRED; 3216 3217 tries = 5; 3218 mtx_lock(&mntvnode_mtx); 3219 loop: 3220 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 3221 if (vp->v_mount != mp) { 3222 if (--tries > 0) 3223 goto loop; 3224 break; 3225 } 3226 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 3227 3228 VI_LOCK(vp); 3229 if (vp->v_iflag & VI_XLOCK) { /* XXX: what if MNT_WAIT? */ 3230 VI_UNLOCK(vp); 3231 continue; 3232 } 3233 3234 if ((vp->v_iflag & VI_OBJDIRTY) && 3235 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 3236 mtx_unlock(&mntvnode_mtx); 3237 if (!vget(vp, 3238 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3239 curthread)) { 3240 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3241 vput(vp); 3242 mtx_lock(&mntvnode_mtx); 3243 continue; 3244 } 3245 3246 if (VOP_GETVOBJECT(vp, &obj) == 0) { 3247 VM_OBJECT_LOCK(obj); 3248 vm_object_page_clean(obj, 0, 0, 3249 flags == MNT_WAIT ? 3250 OBJPC_SYNC : OBJPC_NOSYNC); 3251 VM_OBJECT_UNLOCK(obj); 3252 } 3253 vput(vp); 3254 } 3255 mtx_lock(&mntvnode_mtx); 3256 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3257 if (--tries > 0) 3258 goto loop; 3259 break; 3260 } 3261 } else 3262 VI_UNLOCK(vp); 3263 } 3264 mtx_unlock(&mntvnode_mtx); 3265 } 3266 3267 /* 3268 * Create the VM object needed for VMIO and mmap support. This 3269 * is done for all VREG files in the system. Some filesystems might 3270 * afford the additional metadata buffering capability of the 3271 * VMIO code by making the device node be VMIO mode also. 3272 * 3273 * vp must be locked when vfs_object_create is called. 3274 */ 3275 int 3276 vfs_object_create(vp, td, cred) 3277 struct vnode *vp; 3278 struct thread *td; 3279 struct ucred *cred; 3280 { 3281 GIANT_REQUIRED; 3282 return (VOP_CREATEVOBJECT(vp, cred, td)); 3283 } 3284 3285 /* 3286 * Mark a vnode as free, putting it up for recycling. 3287 */ 3288 void 3289 vfree(vp) 3290 struct vnode *vp; 3291 { 3292 int s; 3293 3294 ASSERT_VI_LOCKED(vp, "vfree"); 3295 s = splbio(); 3296 mtx_lock(&vnode_free_list_mtx); 3297 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3298 if (vp->v_iflag & VI_AGE) { 3299 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3300 } else { 3301 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3302 } 3303 freevnodes++; 3304 mtx_unlock(&vnode_free_list_mtx); 3305 vp->v_iflag &= ~VI_AGE; 3306 vp->v_iflag |= VI_FREE; 3307 splx(s); 3308 } 3309 3310 /* 3311 * Opposite of vfree() - mark a vnode as in use. 3312 */ 3313 void 3314 vbusy(vp) 3315 struct vnode *vp; 3316 { 3317 int s; 3318 3319 s = splbio(); 3320 ASSERT_VI_LOCKED(vp, "vbusy"); 3321 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3322 3323 mtx_lock(&vnode_free_list_mtx); 3324 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3325 freevnodes--; 3326 mtx_unlock(&vnode_free_list_mtx); 3327 3328 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3329 splx(s); 3330 } 3331 3332 /* 3333 * Record a process's interest in events which might happen to 3334 * a vnode. Because poll uses the historic select-style interface 3335 * internally, this routine serves as both the ``check for any 3336 * pending events'' and the ``record my interest in future events'' 3337 * functions. (These are done together, while the lock is held, 3338 * to avoid race conditions.) 3339 */ 3340 int 3341 vn_pollrecord(vp, td, events) 3342 struct vnode *vp; 3343 struct thread *td; 3344 short events; 3345 { 3346 3347 if (vp->v_pollinfo == NULL) 3348 v_addpollinfo(vp); 3349 mtx_lock(&vp->v_pollinfo->vpi_lock); 3350 if (vp->v_pollinfo->vpi_revents & events) { 3351 /* 3352 * This leaves events we are not interested 3353 * in available for the other process which 3354 * which presumably had requested them 3355 * (otherwise they would never have been 3356 * recorded). 3357 */ 3358 events &= vp->v_pollinfo->vpi_revents; 3359 vp->v_pollinfo->vpi_revents &= ~events; 3360 3361 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3362 return events; 3363 } 3364 vp->v_pollinfo->vpi_events |= events; 3365 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3366 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3367 return 0; 3368 } 3369 3370 /* 3371 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3372 * it is possible for us to miss an event due to race conditions, but 3373 * that condition is expected to be rare, so for the moment it is the 3374 * preferred interface. 3375 */ 3376 void 3377 vn_pollevent(vp, events) 3378 struct vnode *vp; 3379 short events; 3380 { 3381 3382 if (vp->v_pollinfo == NULL) 3383 v_addpollinfo(vp); 3384 mtx_lock(&vp->v_pollinfo->vpi_lock); 3385 if (vp->v_pollinfo->vpi_events & events) { 3386 /* 3387 * We clear vpi_events so that we don't 3388 * call selwakeup() twice if two events are 3389 * posted before the polling process(es) is 3390 * awakened. This also ensures that we take at 3391 * most one selwakeup() if the polling process 3392 * is no longer interested. However, it does 3393 * mean that only one event can be noticed at 3394 * a time. (Perhaps we should only clear those 3395 * event bits which we note?) XXX 3396 */ 3397 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3398 vp->v_pollinfo->vpi_revents |= events; 3399 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3400 } 3401 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3402 } 3403 3404 /* 3405 * Wake up anyone polling on vp because it is being revoked. 3406 * This depends on dead_poll() returning POLLHUP for correct 3407 * behavior. 3408 */ 3409 void 3410 vn_pollgone(vp) 3411 struct vnode *vp; 3412 { 3413 3414 mtx_lock(&vp->v_pollinfo->vpi_lock); 3415 VN_KNOTE(vp, NOTE_REVOKE); 3416 if (vp->v_pollinfo->vpi_events) { 3417 vp->v_pollinfo->vpi_events = 0; 3418 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3419 } 3420 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3421 } 3422 3423 3424 3425 /* 3426 * Routine to create and manage a filesystem syncer vnode. 3427 */ 3428 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3429 static int sync_fsync(struct vop_fsync_args *); 3430 static int sync_inactive(struct vop_inactive_args *); 3431 static int sync_reclaim(struct vop_reclaim_args *); 3432 3433 static vop_t **sync_vnodeop_p; 3434 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3435 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3436 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3437 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3438 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3439 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3440 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3441 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3442 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3443 { NULL, NULL } 3444 }; 3445 static struct vnodeopv_desc sync_vnodeop_opv_desc = 3446 { &sync_vnodeop_p, sync_vnodeop_entries }; 3447 3448 VNODEOP_SET(sync_vnodeop_opv_desc); 3449 3450 /* 3451 * Create a new filesystem syncer vnode for the specified mount point. 3452 */ 3453 int 3454 vfs_allocate_syncvnode(mp) 3455 struct mount *mp; 3456 { 3457 struct vnode *vp; 3458 static long start, incr, next; 3459 int error; 3460 3461 /* Allocate a new vnode */ 3462 if ((error = getnewvnode("syncer", mp, sync_vnodeop_p, &vp)) != 0) { 3463 mp->mnt_syncer = NULL; 3464 return (error); 3465 } 3466 vp->v_type = VNON; 3467 /* 3468 * Place the vnode onto the syncer worklist. We attempt to 3469 * scatter them about on the list so that they will go off 3470 * at evenly distributed times even if all the filesystems 3471 * are mounted at once. 3472 */ 3473 next += incr; 3474 if (next == 0 || next > syncer_maxdelay) { 3475 start /= 2; 3476 incr /= 2; 3477 if (start == 0) { 3478 start = syncer_maxdelay / 2; 3479 incr = syncer_maxdelay; 3480 } 3481 next = start; 3482 } 3483 VI_LOCK(vp); 3484 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 3485 VI_UNLOCK(vp); 3486 mp->mnt_syncer = vp; 3487 return (0); 3488 } 3489 3490 /* 3491 * Do a lazy sync of the filesystem. 3492 */ 3493 static int 3494 sync_fsync(ap) 3495 struct vop_fsync_args /* { 3496 struct vnode *a_vp; 3497 struct ucred *a_cred; 3498 int a_waitfor; 3499 struct thread *a_td; 3500 } */ *ap; 3501 { 3502 struct vnode *syncvp = ap->a_vp; 3503 struct mount *mp = syncvp->v_mount; 3504 struct thread *td = ap->a_td; 3505 int error, asyncflag; 3506 3507 /* 3508 * We only need to do something if this is a lazy evaluation. 3509 */ 3510 if (ap->a_waitfor != MNT_LAZY) 3511 return (0); 3512 3513 /* 3514 * Move ourselves to the back of the sync list. 3515 */ 3516 VI_LOCK(syncvp); 3517 vn_syncer_add_to_worklist(syncvp, syncdelay); 3518 VI_UNLOCK(syncvp); 3519 3520 /* 3521 * Walk the list of vnodes pushing all that are dirty and 3522 * not already on the sync list. 3523 */ 3524 mtx_lock(&mountlist_mtx); 3525 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3526 mtx_unlock(&mountlist_mtx); 3527 return (0); 3528 } 3529 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3530 vfs_unbusy(mp, td); 3531 return (0); 3532 } 3533 asyncflag = mp->mnt_flag & MNT_ASYNC; 3534 mp->mnt_flag &= ~MNT_ASYNC; 3535 vfs_msync(mp, MNT_NOWAIT); 3536 error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3537 if (asyncflag) 3538 mp->mnt_flag |= MNT_ASYNC; 3539 vn_finished_write(mp); 3540 vfs_unbusy(mp, td); 3541 return (error); 3542 } 3543 3544 /* 3545 * The syncer vnode is no referenced. 3546 */ 3547 static int 3548 sync_inactive(ap) 3549 struct vop_inactive_args /* { 3550 struct vnode *a_vp; 3551 struct thread *a_td; 3552 } */ *ap; 3553 { 3554 3555 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3556 vgone(ap->a_vp); 3557 return (0); 3558 } 3559 3560 /* 3561 * The syncer vnode is no longer needed and is being decommissioned. 3562 * 3563 * Modifications to the worklist must be protected at splbio(). 3564 */ 3565 static int 3566 sync_reclaim(ap) 3567 struct vop_reclaim_args /* { 3568 struct vnode *a_vp; 3569 } */ *ap; 3570 { 3571 struct vnode *vp = ap->a_vp; 3572 int s; 3573 3574 s = splbio(); 3575 vp->v_mount->mnt_syncer = NULL; 3576 VI_LOCK(vp); 3577 if (vp->v_iflag & VI_ONWORKLST) { 3578 mtx_lock(&sync_mtx); 3579 LIST_REMOVE(vp, v_synclist); 3580 mtx_unlock(&sync_mtx); 3581 vp->v_iflag &= ~VI_ONWORKLST; 3582 } 3583 VI_UNLOCK(vp); 3584 splx(s); 3585 3586 return (0); 3587 } 3588 3589 /* 3590 * extract the dev_t from a VCHR 3591 */ 3592 dev_t 3593 vn_todev(vp) 3594 struct vnode *vp; 3595 { 3596 if (vp->v_type != VCHR) 3597 return (NODEV); 3598 return (vp->v_rdev); 3599 } 3600 3601 /* 3602 * Check if vnode represents a disk device 3603 */ 3604 int 3605 vn_isdisk(vp, errp) 3606 struct vnode *vp; 3607 int *errp; 3608 { 3609 struct cdevsw *cdevsw; 3610 3611 if (vp->v_type != VCHR) { 3612 if (errp != NULL) 3613 *errp = ENOTBLK; 3614 return (0); 3615 } 3616 if (vp->v_rdev == NULL) { 3617 if (errp != NULL) 3618 *errp = ENXIO; 3619 return (0); 3620 } 3621 cdevsw = devsw(vp->v_rdev); 3622 if (cdevsw == NULL) { 3623 if (errp != NULL) 3624 *errp = ENXIO; 3625 return (0); 3626 } 3627 if (!(cdevsw->d_flags & D_DISK)) { 3628 if (errp != NULL) 3629 *errp = ENOTBLK; 3630 return (0); 3631 } 3632 if (errp != NULL) 3633 *errp = 0; 3634 return (1); 3635 } 3636 3637 /* 3638 * Free data allocated by namei(); see namei(9) for details. 3639 */ 3640 void 3641 NDFREE(ndp, flags) 3642 struct nameidata *ndp; 3643 const uint flags; 3644 { 3645 if (!(flags & NDF_NO_FREE_PNBUF) && 3646 (ndp->ni_cnd.cn_flags & HASBUF)) { 3647 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3648 ndp->ni_cnd.cn_flags &= ~HASBUF; 3649 } 3650 if (!(flags & NDF_NO_DVP_UNLOCK) && 3651 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3652 ndp->ni_dvp != ndp->ni_vp) 3653 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3654 if (!(flags & NDF_NO_DVP_RELE) && 3655 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3656 vrele(ndp->ni_dvp); 3657 ndp->ni_dvp = NULL; 3658 } 3659 if (!(flags & NDF_NO_VP_UNLOCK) && 3660 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3661 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3662 if (!(flags & NDF_NO_VP_RELE) && 3663 ndp->ni_vp) { 3664 vrele(ndp->ni_vp); 3665 ndp->ni_vp = NULL; 3666 } 3667 if (!(flags & NDF_NO_STARTDIR_RELE) && 3668 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3669 vrele(ndp->ni_startdir); 3670 ndp->ni_startdir = NULL; 3671 } 3672 } 3673 3674 /* 3675 * Common filesystem object access control check routine. Accepts a 3676 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3677 * and optional call-by-reference privused argument allowing vaccess() 3678 * to indicate to the caller whether privilege was used to satisfy the 3679 * request (obsoleted). Returns 0 on success, or an errno on failure. 3680 */ 3681 int 3682 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3683 enum vtype type; 3684 mode_t file_mode; 3685 uid_t file_uid; 3686 gid_t file_gid; 3687 mode_t acc_mode; 3688 struct ucred *cred; 3689 int *privused; 3690 { 3691 mode_t dac_granted; 3692 #ifdef CAPABILITIES 3693 mode_t cap_granted; 3694 #endif 3695 3696 /* 3697 * Look for a normal, non-privileged way to access the file/directory 3698 * as requested. If it exists, go with that. 3699 */ 3700 3701 if (privused != NULL) 3702 *privused = 0; 3703 3704 dac_granted = 0; 3705 3706 /* Check the owner. */ 3707 if (cred->cr_uid == file_uid) { 3708 dac_granted |= VADMIN; 3709 if (file_mode & S_IXUSR) 3710 dac_granted |= VEXEC; 3711 if (file_mode & S_IRUSR) 3712 dac_granted |= VREAD; 3713 if (file_mode & S_IWUSR) 3714 dac_granted |= (VWRITE | VAPPEND); 3715 3716 if ((acc_mode & dac_granted) == acc_mode) 3717 return (0); 3718 3719 goto privcheck; 3720 } 3721 3722 /* Otherwise, check the groups (first match) */ 3723 if (groupmember(file_gid, cred)) { 3724 if (file_mode & S_IXGRP) 3725 dac_granted |= VEXEC; 3726 if (file_mode & S_IRGRP) 3727 dac_granted |= VREAD; 3728 if (file_mode & S_IWGRP) 3729 dac_granted |= (VWRITE | VAPPEND); 3730 3731 if ((acc_mode & dac_granted) == acc_mode) 3732 return (0); 3733 3734 goto privcheck; 3735 } 3736 3737 /* Otherwise, check everyone else. */ 3738 if (file_mode & S_IXOTH) 3739 dac_granted |= VEXEC; 3740 if (file_mode & S_IROTH) 3741 dac_granted |= VREAD; 3742 if (file_mode & S_IWOTH) 3743 dac_granted |= (VWRITE | VAPPEND); 3744 if ((acc_mode & dac_granted) == acc_mode) 3745 return (0); 3746 3747 privcheck: 3748 if (!suser_cred(cred, PRISON_ROOT)) { 3749 /* XXX audit: privilege used */ 3750 if (privused != NULL) 3751 *privused = 1; 3752 return (0); 3753 } 3754 3755 #ifdef CAPABILITIES 3756 /* 3757 * Build a capability mask to determine if the set of capabilities 3758 * satisfies the requirements when combined with the granted mask 3759 * from above. 3760 * For each capability, if the capability is required, bitwise 3761 * or the request type onto the cap_granted mask. 3762 */ 3763 cap_granted = 0; 3764 3765 if (type == VDIR) { 3766 /* 3767 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3768 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3769 */ 3770 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3771 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3772 cap_granted |= VEXEC; 3773 } else { 3774 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3775 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3776 cap_granted |= VEXEC; 3777 } 3778 3779 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3780 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3781 cap_granted |= VREAD; 3782 3783 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3784 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3785 cap_granted |= (VWRITE | VAPPEND); 3786 3787 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3788 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3789 cap_granted |= VADMIN; 3790 3791 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3792 /* XXX audit: privilege used */ 3793 if (privused != NULL) 3794 *privused = 1; 3795 return (0); 3796 } 3797 #endif 3798 3799 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3800 } 3801 3802 /* 3803 * Credential check based on process requesting service, and per-attribute 3804 * permissions. 3805 */ 3806 int 3807 extattr_check_cred(struct vnode *vp, int attrnamespace, 3808 struct ucred *cred, struct thread *td, int access) 3809 { 3810 3811 /* 3812 * Kernel-invoked always succeeds. 3813 */ 3814 if (cred == NOCRED) 3815 return (0); 3816 3817 /* 3818 * Do not allow privileged processes in jail to directly 3819 * manipulate system attributes. 3820 * 3821 * XXX What capability should apply here? 3822 * Probably CAP_SYS_SETFFLAG. 3823 */ 3824 switch (attrnamespace) { 3825 case EXTATTR_NAMESPACE_SYSTEM: 3826 /* Potentially should be: return (EPERM); */ 3827 return (suser_cred(cred, 0)); 3828 case EXTATTR_NAMESPACE_USER: 3829 return (VOP_ACCESS(vp, access, cred, td)); 3830 default: 3831 return (EPERM); 3832 } 3833 } 3834