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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 35 */ 36 37 /* 38 * External virtual filesystem routines 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_ddb.h" 45 #include "opt_mac.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/conf.h> 52 #include <sys/event.h> 53 #include <sys/eventhandler.h> 54 #include <sys/extattr.h> 55 #include <sys/fcntl.h> 56 #include <sys/kdb.h> 57 #include <sys/kernel.h> 58 #include <sys/kthread.h> 59 #include <sys/mac.h> 60 #include <sys/malloc.h> 61 #include <sys/mount.h> 62 #include <sys/namei.h> 63 #include <sys/reboot.h> 64 #include <sys/sleepqueue.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, struct cdev *nvp_rdev); 83 static void delmntque(struct vnode *vp); 84 static void insmntque(struct vnode *vp, struct mount *mp); 85 static void vclean(struct vnode *vp, int flags, struct thread *td); 86 static void vlruvp(struct vnode *vp); 87 static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, 88 int slpflag, int slptimeo, int *errorp); 89 static void syncer_shutdown(void *arg, int howto); 90 static int vtryrecycle(struct vnode *vp); 91 static void vx_lock(struct vnode *vp); 92 static void vx_unlock(struct vnode *vp); 93 static void vgonechrl(struct vnode *vp, struct thread *td); 94 95 96 /* 97 * Number of vnodes in existence. Increased whenever getnewvnode() 98 * allocates a new vnode, never decreased. 99 */ 100 static unsigned long numvnodes; 101 102 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 103 104 /* 105 * Conversion tables for conversion from vnode types to inode formats 106 * and back. 107 */ 108 enum vtype iftovt_tab[16] = { 109 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 110 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 111 }; 112 int vttoif_tab[9] = { 113 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 114 S_IFSOCK, S_IFIFO, S_IFMT, 115 }; 116 117 /* 118 * List of vnodes that are ready for recycling. 119 */ 120 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 121 122 /* 123 * Minimum number of free vnodes. If there are fewer than this free vnodes, 124 * getnewvnode() will return a newly allocated vnode. 125 */ 126 static u_long wantfreevnodes = 25; 127 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 128 /* Number of vnodes in the free list. */ 129 static u_long freevnodes; 130 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 131 132 /* 133 * Various variables used for debugging the new implementation of 134 * reassignbuf(). 135 * XXX these are probably of (very) limited utility now. 136 */ 137 static int reassignbufcalls; 138 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 139 static int nameileafonly; 140 SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 141 142 /* 143 * Cache for the mount type id assigned to NFS. This is used for 144 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 145 */ 146 int nfs_mount_type = -1; 147 148 /* To keep more than one thread at a time from running vfs_getnewfsid */ 149 static struct mtx mntid_mtx; 150 151 /* 152 * Lock for any access to the following: 153 * vnode_free_list 154 * numvnodes 155 * freevnodes 156 */ 157 static struct mtx vnode_free_list_mtx; 158 159 /* Publicly exported FS */ 160 struct nfs_public nfs_pub; 161 162 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 163 static uma_zone_t vnode_zone; 164 static uma_zone_t vnodepoll_zone; 165 166 /* Set to 1 to print out reclaim of active vnodes */ 167 int prtactive; 168 169 /* 170 * The workitem queue. 171 * 172 * It is useful to delay writes of file data and filesystem metadata 173 * for tens of seconds so that quickly created and deleted files need 174 * not waste disk bandwidth being created and removed. To realize this, 175 * we append vnodes to a "workitem" queue. When running with a soft 176 * updates implementation, most pending metadata dependencies should 177 * not wait for more than a few seconds. Thus, mounted on block devices 178 * are delayed only about a half the time that file data is delayed. 179 * Similarly, directory updates are more critical, so are only delayed 180 * about a third the time that file data is delayed. Thus, there are 181 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 182 * one each second (driven off the filesystem syncer process). The 183 * syncer_delayno variable indicates the next queue that is to be processed. 184 * Items that need to be processed soon are placed in this queue: 185 * 186 * syncer_workitem_pending[syncer_delayno] 187 * 188 * A delay of fifteen seconds is done by placing the request fifteen 189 * entries later in the queue: 190 * 191 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 192 * 193 */ 194 static int syncer_delayno; 195 static long syncer_mask; 196 LIST_HEAD(synclist, bufobj); 197 static struct synclist *syncer_workitem_pending; 198 /* 199 * The sync_mtx protects: 200 * bo->bo_synclist 201 * sync_vnode_count 202 * syncer_delayno 203 * syncer_state 204 * syncer_workitem_pending 205 * syncer_worklist_len 206 * rushjob 207 */ 208 static struct mtx sync_mtx; 209 210 #define SYNCER_MAXDELAY 32 211 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 212 static int syncdelay = 30; /* max time to delay syncing data */ 213 static int filedelay = 30; /* time to delay syncing files */ 214 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 215 static int dirdelay = 29; /* time to delay syncing directories */ 216 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 217 static int metadelay = 28; /* time to delay syncing metadata */ 218 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 219 static int rushjob; /* number of slots to run ASAP */ 220 static int stat_rush_requests; /* number of times I/O speeded up */ 221 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 222 223 /* 224 * When shutting down the syncer, run it at four times normal speed. 225 */ 226 #define SYNCER_SHUTDOWN_SPEEDUP 4 227 static int sync_vnode_count; 228 static int syncer_worklist_len; 229 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 230 syncer_state; 231 232 /* 233 * Number of vnodes we want to exist at any one time. This is mostly used 234 * to size hash tables in vnode-related code. It is normally not used in 235 * getnewvnode(), as wantfreevnodes is normally nonzero.) 236 * 237 * XXX desiredvnodes is historical cruft and should not exist. 238 */ 239 int desiredvnodes; 240 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 241 &desiredvnodes, 0, "Maximum number of vnodes"); 242 static int minvnodes; 243 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 244 &minvnodes, 0, "Minimum number of vnodes"); 245 static int vnlru_nowhere; 246 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 247 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 248 249 /* Hook for calling soft updates. */ 250 int (*softdep_process_worklist_hook)(struct mount *); 251 252 /* 253 * Initialize the vnode management data structures. 254 */ 255 #ifndef MAXVNODES_MAX 256 #define MAXVNODES_MAX 100000 257 #endif 258 static void 259 vntblinit(void *dummy __unused) 260 { 261 262 /* 263 * Desiredvnodes is a function of the physical memory size and 264 * the kernel's heap size. Specifically, desiredvnodes scales 265 * in proportion to the physical memory size until two fifths 266 * of the kernel's heap size is consumed by vnodes and vm 267 * objects. 268 */ 269 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / 270 (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); 271 if (desiredvnodes > MAXVNODES_MAX) { 272 if (bootverbose) 273 printf("Reducing kern.maxvnodes %d -> %d\n", 274 desiredvnodes, MAXVNODES_MAX); 275 desiredvnodes = MAXVNODES_MAX; 276 } 277 minvnodes = desiredvnodes / 4; 278 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 279 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 280 TAILQ_INIT(&vnode_free_list); 281 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 282 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 283 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 284 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 285 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 286 /* 287 * Initialize the filesystem syncer. 288 */ 289 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 290 &syncer_mask); 291 syncer_maxdelay = syncer_mask + 1; 292 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 293 } 294 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 295 296 297 /* 298 * Mark a mount point as busy. Used to synchronize access and to delay 299 * unmounting. Interlock is not released on failure. 300 */ 301 int 302 vfs_busy(mp, flags, interlkp, td) 303 struct mount *mp; 304 int flags; 305 struct mtx *interlkp; 306 struct thread *td; 307 { 308 int lkflags; 309 310 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 311 if (flags & LK_NOWAIT) 312 return (ENOENT); 313 mp->mnt_kern_flag |= MNTK_MWAIT; 314 /* 315 * Since all busy locks are shared except the exclusive 316 * lock granted when unmounting, the only place that a 317 * wakeup needs to be done is at the release of the 318 * exclusive lock at the end of dounmount. 319 */ 320 msleep(mp, interlkp, PVFS, "vfs_busy", 0); 321 return (ENOENT); 322 } 323 lkflags = LK_SHARED | LK_NOPAUSE; 324 if (interlkp) 325 lkflags |= LK_INTERLOCK; 326 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 327 panic("vfs_busy: unexpected lock failure"); 328 return (0); 329 } 330 331 /* 332 * Free a busy filesystem. 333 */ 334 void 335 vfs_unbusy(mp, td) 336 struct mount *mp; 337 struct thread *td; 338 { 339 340 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 341 } 342 343 /* 344 * Lookup a mount point by filesystem identifier. 345 */ 346 struct mount * 347 vfs_getvfs(fsid) 348 fsid_t *fsid; 349 { 350 register struct mount *mp; 351 352 mtx_lock(&mountlist_mtx); 353 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 354 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 355 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 356 mtx_unlock(&mountlist_mtx); 357 return (mp); 358 } 359 } 360 mtx_unlock(&mountlist_mtx); 361 return ((struct mount *) 0); 362 } 363 364 /* 365 * Check if a user can access priveledged mount options. 366 */ 367 int 368 vfs_suser(struct mount *mp, struct thread *td) 369 { 370 int error; 371 372 if ((mp->mnt_flag & MNT_USER) == 0 || 373 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 374 if ((error = suser(td)) != 0) 375 return (error); 376 } 377 return (0); 378 } 379 380 /* 381 * Get a new unique fsid. Try to make its val[0] unique, since this value 382 * will be used to create fake device numbers for stat(). Also try (but 383 * not so hard) make its val[0] unique mod 2^16, since some emulators only 384 * support 16-bit device numbers. We end up with unique val[0]'s for the 385 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 386 * 387 * Keep in mind that several mounts may be running in parallel. Starting 388 * the search one past where the previous search terminated is both a 389 * micro-optimization and a defense against returning the same fsid to 390 * different mounts. 391 */ 392 void 393 vfs_getnewfsid(mp) 394 struct mount *mp; 395 { 396 static u_int16_t mntid_base; 397 fsid_t tfsid; 398 int mtype; 399 400 mtx_lock(&mntid_mtx); 401 mtype = mp->mnt_vfc->vfc_typenum; 402 tfsid.val[1] = mtype; 403 mtype = (mtype & 0xFF) << 24; 404 for (;;) { 405 tfsid.val[0] = makedev(255, 406 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 407 mntid_base++; 408 if (vfs_getvfs(&tfsid) == NULL) 409 break; 410 } 411 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 412 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 413 mtx_unlock(&mntid_mtx); 414 } 415 416 /* 417 * Knob to control the precision of file timestamps: 418 * 419 * 0 = seconds only; nanoseconds zeroed. 420 * 1 = seconds and nanoseconds, accurate within 1/HZ. 421 * 2 = seconds and nanoseconds, truncated to microseconds. 422 * >=3 = seconds and nanoseconds, maximum precision. 423 */ 424 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 425 426 static int timestamp_precision = TSP_SEC; 427 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 428 ×tamp_precision, 0, ""); 429 430 /* 431 * Get a current timestamp. 432 */ 433 void 434 vfs_timestamp(tsp) 435 struct timespec *tsp; 436 { 437 struct timeval tv; 438 439 switch (timestamp_precision) { 440 case TSP_SEC: 441 tsp->tv_sec = time_second; 442 tsp->tv_nsec = 0; 443 break; 444 case TSP_HZ: 445 getnanotime(tsp); 446 break; 447 case TSP_USEC: 448 microtime(&tv); 449 TIMEVAL_TO_TIMESPEC(&tv, tsp); 450 break; 451 case TSP_NSEC: 452 default: 453 nanotime(tsp); 454 break; 455 } 456 } 457 458 /* 459 * Set vnode attributes to VNOVAL 460 */ 461 void 462 vattr_null(vap) 463 register struct vattr *vap; 464 { 465 466 vap->va_type = VNON; 467 vap->va_size = VNOVAL; 468 vap->va_bytes = VNOVAL; 469 vap->va_mode = VNOVAL; 470 vap->va_nlink = VNOVAL; 471 vap->va_uid = VNOVAL; 472 vap->va_gid = VNOVAL; 473 vap->va_fsid = VNOVAL; 474 vap->va_fileid = VNOVAL; 475 vap->va_blocksize = VNOVAL; 476 vap->va_rdev = VNOVAL; 477 vap->va_atime.tv_sec = VNOVAL; 478 vap->va_atime.tv_nsec = VNOVAL; 479 vap->va_mtime.tv_sec = VNOVAL; 480 vap->va_mtime.tv_nsec = VNOVAL; 481 vap->va_ctime.tv_sec = VNOVAL; 482 vap->va_ctime.tv_nsec = VNOVAL; 483 vap->va_birthtime.tv_sec = VNOVAL; 484 vap->va_birthtime.tv_nsec = VNOVAL; 485 vap->va_flags = VNOVAL; 486 vap->va_gen = VNOVAL; 487 vap->va_vaflags = 0; 488 } 489 490 /* 491 * This routine is called when we have too many vnodes. It attempts 492 * to free <count> vnodes and will potentially free vnodes that still 493 * have VM backing store (VM backing store is typically the cause 494 * of a vnode blowout so we want to do this). Therefore, this operation 495 * is not considered cheap. 496 * 497 * A number of conditions may prevent a vnode from being reclaimed. 498 * the buffer cache may have references on the vnode, a directory 499 * vnode may still have references due to the namei cache representing 500 * underlying files, or the vnode may be in active use. It is not 501 * desireable to reuse such vnodes. These conditions may cause the 502 * number of vnodes to reach some minimum value regardless of what 503 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 504 */ 505 static int 506 vlrureclaim(struct mount *mp) 507 { 508 struct vnode *vp; 509 int done; 510 int trigger; 511 int usevnodes; 512 int count; 513 514 /* 515 * Calculate the trigger point, don't allow user 516 * screwups to blow us up. This prevents us from 517 * recycling vnodes with lots of resident pages. We 518 * aren't trying to free memory, we are trying to 519 * free vnodes. 520 */ 521 usevnodes = desiredvnodes; 522 if (usevnodes <= 0) 523 usevnodes = 1; 524 trigger = cnt.v_page_count * 2 / usevnodes; 525 526 done = 0; 527 MNT_ILOCK(mp); 528 count = mp->mnt_nvnodelistsize / 10 + 1; 529 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 530 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 531 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 532 533 if (vp->v_type != VNON && 534 vp->v_type != VBAD && 535 VI_TRYLOCK(vp)) { 536 if (VMIGHTFREE(vp) && /* critical path opt */ 537 (vp->v_object == NULL || 538 vp->v_object->resident_page_count < trigger)) { 539 MNT_IUNLOCK(mp); 540 vgonel(vp, curthread); 541 done++; 542 MNT_ILOCK(mp); 543 } else 544 VI_UNLOCK(vp); 545 } 546 --count; 547 } 548 MNT_IUNLOCK(mp); 549 return done; 550 } 551 552 /* 553 * Attempt to recycle vnodes in a context that is always safe to block. 554 * Calling vlrurecycle() from the bowels of filesystem code has some 555 * interesting deadlock problems. 556 */ 557 static struct proc *vnlruproc; 558 static int vnlruproc_sig; 559 560 static void 561 vnlru_proc(void) 562 { 563 struct mount *mp, *nmp; 564 int done; 565 struct proc *p = vnlruproc; 566 struct thread *td = FIRST_THREAD_IN_PROC(p); 567 568 mtx_lock(&Giant); 569 570 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 571 SHUTDOWN_PRI_FIRST); 572 573 for (;;) { 574 kthread_suspend_check(p); 575 mtx_lock(&vnode_free_list_mtx); 576 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 577 mtx_unlock(&vnode_free_list_mtx); 578 vnlruproc_sig = 0; 579 wakeup(&vnlruproc_sig); 580 tsleep(vnlruproc, PVFS, "vlruwt", hz); 581 continue; 582 } 583 mtx_unlock(&vnode_free_list_mtx); 584 done = 0; 585 mtx_lock(&mountlist_mtx); 586 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 587 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 588 nmp = TAILQ_NEXT(mp, mnt_list); 589 continue; 590 } 591 done += vlrureclaim(mp); 592 mtx_lock(&mountlist_mtx); 593 nmp = TAILQ_NEXT(mp, mnt_list); 594 vfs_unbusy(mp, td); 595 } 596 mtx_unlock(&mountlist_mtx); 597 if (done == 0) { 598 #if 0 599 /* These messages are temporary debugging aids */ 600 if (vnlru_nowhere < 5) 601 printf("vnlru process getting nowhere..\n"); 602 else if (vnlru_nowhere == 5) 603 printf("vnlru process messages stopped.\n"); 604 #endif 605 vnlru_nowhere++; 606 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 607 } 608 } 609 } 610 611 static struct kproc_desc vnlru_kp = { 612 "vnlru", 613 vnlru_proc, 614 &vnlruproc 615 }; 616 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 617 618 619 /* 620 * Routines having to do with the management of the vnode table. 621 */ 622 623 /* 624 * Check to see if a free vnode can be recycled. If it can, 625 * recycle it and return it with the vnode interlock held. 626 */ 627 static int 628 vtryrecycle(struct vnode *vp) 629 { 630 struct thread *td = curthread; 631 vm_object_t object; 632 struct mount *vnmp; 633 int error; 634 635 /* Don't recycle if we can't get the interlock */ 636 if (!VI_TRYLOCK(vp)) 637 return (EWOULDBLOCK); 638 /* 639 * This vnode may found and locked via some other list, if so we 640 * can't recycle it yet. 641 */ 642 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 643 return (EWOULDBLOCK); 644 /* 645 * Don't recycle if its filesystem is being suspended. 646 */ 647 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 648 VOP_UNLOCK(vp, 0, td); 649 return (EBUSY); 650 } 651 652 /* 653 * Don't recycle if we still have cached pages. 654 */ 655 if (VOP_GETVOBJECT(vp, &object) == 0) { 656 VM_OBJECT_LOCK(object); 657 if (object->resident_page_count || 658 object->ref_count) { 659 VM_OBJECT_UNLOCK(object); 660 error = EBUSY; 661 goto done; 662 } 663 VM_OBJECT_UNLOCK(object); 664 } 665 if (LIST_FIRST(&vp->v_cache_src)) { 666 /* 667 * note: nameileafonly sysctl is temporary, 668 * for debugging only, and will eventually be 669 * removed. 670 */ 671 if (nameileafonly > 0) { 672 /* 673 * Do not reuse namei-cached directory 674 * vnodes that have cached 675 * subdirectories. 676 */ 677 if (cache_leaf_test(vp) < 0) { 678 error = EISDIR; 679 goto done; 680 } 681 } else if (nameileafonly < 0 || 682 vmiodirenable == 0) { 683 /* 684 * Do not reuse namei-cached directory 685 * vnodes if nameileafonly is -1 or 686 * if VMIO backing for directories is 687 * turned off (otherwise we reuse them 688 * too quickly). 689 */ 690 error = EBUSY; 691 goto done; 692 } 693 } 694 /* 695 * If we got this far, we need to acquire the interlock and see if 696 * anyone picked up this vnode from another list. If not, we will 697 * mark it with XLOCK via vgonel() so that anyone who does find it 698 * will skip over it. 699 */ 700 VI_LOCK(vp); 701 if (VSHOULDBUSY(vp) && (vp->v_iflag & VI_XLOCK) == 0) { 702 VI_UNLOCK(vp); 703 error = EBUSY; 704 goto done; 705 } 706 mtx_lock(&vnode_free_list_mtx); 707 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 708 vp->v_iflag &= ~VI_FREE; 709 mtx_unlock(&vnode_free_list_mtx); 710 vp->v_iflag |= VI_DOOMED; 711 if ((vp->v_type != VBAD) || (vp->v_data != NULL)) { 712 VOP_UNLOCK(vp, 0, td); 713 vgonel(vp, td); 714 VI_LOCK(vp); 715 } else 716 VOP_UNLOCK(vp, 0, td); 717 vn_finished_write(vnmp); 718 return (0); 719 done: 720 VOP_UNLOCK(vp, 0, td); 721 vn_finished_write(vnmp); 722 return (error); 723 } 724 725 /* 726 * Return the next vnode from the free list. 727 */ 728 int 729 getnewvnode(tag, mp, vops, vpp) 730 const char *tag; 731 struct mount *mp; 732 vop_t **vops; 733 struct vnode **vpp; 734 { 735 struct vnode *vp = NULL; 736 struct vpollinfo *pollinfo = NULL; 737 struct bufobj *bo; 738 739 mtx_lock(&vnode_free_list_mtx); 740 741 /* 742 * Try to reuse vnodes if we hit the max. This situation only 743 * occurs in certain large-memory (2G+) situations. We cannot 744 * attempt to directly reclaim vnodes due to nasty recursion 745 * problems. 746 */ 747 while (numvnodes - freevnodes > desiredvnodes) { 748 if (vnlruproc_sig == 0) { 749 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 750 wakeup(vnlruproc); 751 } 752 mtx_unlock(&vnode_free_list_mtx); 753 tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); 754 mtx_lock(&vnode_free_list_mtx); 755 } 756 757 /* 758 * Attempt to reuse a vnode already on the free list, allocating 759 * a new vnode if we can't find one or if we have not reached a 760 * good minimum for good LRU performance. 761 */ 762 763 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 764 int error; 765 int count; 766 767 for (count = 0; count < freevnodes; count++) { 768 vp = TAILQ_FIRST(&vnode_free_list); 769 770 KASSERT(vp->v_usecount == 0 && 771 (vp->v_iflag & VI_DOINGINACT) == 0, 772 ("getnewvnode: free vnode isn't")); 773 774 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 775 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 776 mtx_unlock(&vnode_free_list_mtx); 777 error = vtryrecycle(vp); 778 mtx_lock(&vnode_free_list_mtx); 779 if (error == 0) 780 break; 781 vp = NULL; 782 } 783 } 784 if (vp) { 785 freevnodes--; 786 bo = &vp->v_bufobj; 787 mtx_unlock(&vnode_free_list_mtx); 788 789 #ifdef INVARIANTS 790 { 791 if (vp->v_data) 792 printf("cleaned vnode isn't, " 793 "address %p, inode %p\n", 794 vp, vp->v_data); 795 if (bo->bo_numoutput) 796 panic("Clean vnode has pending I/O's"); 797 if (vp->v_writecount != 0) 798 panic("Non-zero write count"); 799 } 800 #endif 801 if ((pollinfo = vp->v_pollinfo) != NULL) { 802 /* 803 * To avoid lock order reversals, the call to 804 * uma_zfree() must be delayed until the vnode 805 * interlock is released. 806 */ 807 vp->v_pollinfo = NULL; 808 } 809 #ifdef MAC 810 mac_destroy_vnode(vp); 811 #endif 812 vp->v_iflag = 0; 813 vp->v_vflag = 0; 814 vp->v_lastw = 0; 815 vp->v_lasta = 0; 816 vp->v_cstart = 0; 817 vp->v_clen = 0; 818 vp->v_socket = 0; 819 lockdestroy(vp->v_vnlock); 820 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 821 KASSERT(bo->bo_clean.bv_cnt == 0, ("cleanbufcnt not 0")); 822 KASSERT(bo->bo_clean.bv_root == NULL, ("cleanblkroot not NULL")); 823 KASSERT(bo->bo_dirty.bv_cnt == 0, ("dirtybufcnt not 0")); 824 KASSERT(bo->bo_dirty.bv_root == NULL, ("dirtyblkroot not NULL")); 825 } else { 826 numvnodes++; 827 mtx_unlock(&vnode_free_list_mtx); 828 829 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 830 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 831 VI_LOCK(vp); 832 vp->v_dd = vp; 833 bo = &vp->v_bufobj; 834 bo->__bo_vnode = vp; 835 bo->bo_mtx = &vp->v_interlock; 836 vp->v_vnlock = &vp->v_lock; 837 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 838 cache_purge(vp); /* Sets up v_id. */ 839 LIST_INIT(&vp->v_cache_src); 840 TAILQ_INIT(&vp->v_cache_dst); 841 } 842 843 TAILQ_INIT(&bo->bo_clean.bv_hd); 844 TAILQ_INIT(&bo->bo_dirty.bv_hd); 845 bo->bo_ops = &buf_ops_bio; 846 bo->bo_private = vp; 847 vp->v_type = VNON; 848 vp->v_tag = tag; 849 vp->v_op = vops; 850 *vpp = vp; 851 vp->v_usecount = 1; 852 vp->v_data = 0; 853 VI_UNLOCK(vp); 854 if (pollinfo != NULL) { 855 knlist_destroy(&pollinfo->vpi_selinfo.si_note); 856 mtx_destroy(&pollinfo->vpi_lock); 857 uma_zfree(vnodepoll_zone, pollinfo); 858 } 859 #ifdef MAC 860 mac_init_vnode(vp); 861 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 862 mac_associate_vnode_singlelabel(mp, vp); 863 else if (mp == NULL) 864 printf("NULL mp in getnewvnode()\n"); 865 #endif 866 delmntque(vp); 867 if (mp != NULL) { 868 insmntque(vp, mp); 869 bo->bo_bsize = mp->mnt_stat.f_iosize; 870 } 871 872 return (0); 873 } 874 875 /* 876 * Delete from old mount point vnode list, if on one. 877 */ 878 static void 879 delmntque(struct vnode *vp) 880 { 881 struct mount *mp; 882 883 if (vp->v_mount == NULL) 884 return; 885 mp = vp->v_mount; 886 MNT_ILOCK(mp); 887 vp->v_mount = NULL; 888 KASSERT(mp->mnt_nvnodelistsize > 0, 889 ("bad mount point vnode list size")); 890 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 891 mp->mnt_nvnodelistsize--; 892 MNT_IUNLOCK(mp); 893 } 894 895 /* 896 * Insert into list of vnodes for the new mount point, if available. 897 */ 898 static void 899 insmntque(struct vnode *vp, struct mount *mp) 900 { 901 902 vp->v_mount = mp; 903 KASSERT(mp != NULL, ("Don't call insmntque(foo, NULL)")); 904 MNT_ILOCK(vp->v_mount); 905 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 906 mp->mnt_nvnodelistsize++; 907 MNT_IUNLOCK(vp->v_mount); 908 } 909 910 /* 911 * Flush out and invalidate all buffers associated with a vnode. 912 * Called with the underlying object locked. 913 */ 914 int 915 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 916 struct vnode *vp; 917 int flags; 918 struct ucred *cred; 919 struct thread *td; 920 int slpflag, slptimeo; 921 { 922 struct buf *blist; 923 int error; 924 vm_object_t object; 925 struct bufobj *bo; 926 927 GIANT_REQUIRED; 928 929 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 930 931 bo = &vp->v_bufobj; 932 BO_LOCK(bo); 933 if (flags & V_SAVE) { 934 error = bufobj_wwait(bo, slpflag, slptimeo); 935 if (error) { 936 VI_UNLOCK(vp); 937 return (error); 938 } 939 if (bo->bo_dirty.bv_cnt > 0) { 940 VI_UNLOCK(vp); 941 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 942 return (error); 943 /* 944 * XXX We could save a lock/unlock if this was only 945 * enabled under INVARIANTS 946 */ 947 VI_LOCK(vp); 948 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 949 panic("vinvalbuf: dirty bufs"); 950 } 951 } 952 /* 953 * If you alter this loop please notice that interlock is dropped and 954 * reacquired in flushbuflist. Special care is needed to ensure that 955 * no race conditions occur from this. 956 */ 957 for (error = 0;;) { 958 blist = TAILQ_FIRST(&vp->v_bufobj.bo_clean.bv_hd); 959 if (blist != NULL && 960 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 961 if (error) 962 break; 963 continue; 964 } 965 blist = TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd); 966 if (blist != NULL && 967 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 968 if (error) 969 break; 970 continue; 971 } 972 break; 973 } 974 if (error) { 975 VI_UNLOCK(vp); 976 return (error); 977 } 978 979 /* 980 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 981 * have write I/O in-progress but if there is a VM object then the 982 * VM object can also have read-I/O in-progress. 983 */ 984 do { 985 bufobj_wwait(bo, 0, 0); 986 VI_UNLOCK(vp); 987 if (VOP_GETVOBJECT(vp, &object) == 0) { 988 VM_OBJECT_LOCK(object); 989 vm_object_pip_wait(object, "vnvlbx"); 990 VM_OBJECT_UNLOCK(object); 991 } 992 VI_LOCK(vp); 993 } while (bo->bo_numoutput > 0); 994 VI_UNLOCK(vp); 995 996 /* 997 * Destroy the copy in the VM cache, too. 998 */ 999 if (VOP_GETVOBJECT(vp, &object) == 0) { 1000 VM_OBJECT_LOCK(object); 1001 vm_object_page_remove(object, 0, 0, 1002 (flags & V_SAVE) ? TRUE : FALSE); 1003 VM_OBJECT_UNLOCK(object); 1004 } 1005 1006 #ifdef INVARIANTS 1007 VI_LOCK(vp); 1008 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1009 (vp->v_bufobj.bo_dirty.bv_cnt > 0 || 1010 vp->v_bufobj.bo_clean.bv_cnt > 0)) 1011 panic("vinvalbuf: flush failed"); 1012 VI_UNLOCK(vp); 1013 #endif 1014 return (0); 1015 } 1016 1017 /* 1018 * Flush out buffers on the specified list. 1019 * 1020 */ 1021 static int 1022 flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) 1023 struct buf *blist; 1024 int flags; 1025 struct vnode *vp; 1026 int slpflag, slptimeo; 1027 int *errorp; 1028 { 1029 struct buf *bp, *nbp; 1030 int found, error; 1031 1032 ASSERT_VI_LOCKED(vp, "flushbuflist"); 1033 1034 for (found = 0, bp = blist; bp; bp = nbp) { 1035 nbp = TAILQ_NEXT(bp, b_bobufs); 1036 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1037 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1038 continue; 1039 } 1040 found += 1; 1041 error = BUF_TIMELOCK(bp, 1042 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), 1043 "flushbuf", slpflag, slptimeo); 1044 if (error) { 1045 if (error != ENOLCK) 1046 *errorp = error; 1047 goto done; 1048 } 1049 /* 1050 * XXX Since there are no node locks for NFS, I 1051 * believe there is a slight chance that a delayed 1052 * write will occur while sleeping just above, so 1053 * check for it. Note that vfs_bio_awrite expects 1054 * buffers to reside on a queue, while bwrite and 1055 * brelse do not. 1056 */ 1057 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1058 (flags & V_SAVE)) { 1059 1060 if (bp->b_vp == vp) { 1061 if (bp->b_flags & B_CLUSTEROK) { 1062 vfs_bio_awrite(bp); 1063 } else { 1064 bremfree(bp); 1065 bp->b_flags |= B_ASYNC; 1066 bwrite(bp); 1067 } 1068 } else { 1069 bremfree(bp); 1070 (void) bwrite(bp); 1071 } 1072 goto done; 1073 } 1074 bremfree(bp); 1075 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1076 bp->b_flags &= ~B_ASYNC; 1077 brelse(bp); 1078 VI_LOCK(vp); 1079 } 1080 return (found); 1081 done: 1082 VI_LOCK(vp); 1083 return (found); 1084 } 1085 1086 /* 1087 * Truncate a file's buffer and pages to a specified length. This 1088 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1089 * sync activity. 1090 */ 1091 int 1092 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td, off_t length, int blksize) 1093 { 1094 struct buf *bp, *nbp; 1095 int anyfreed; 1096 int trunclbn; 1097 struct bufobj *bo; 1098 1099 /* 1100 * Round up to the *next* lbn. 1101 */ 1102 trunclbn = (length + blksize - 1) / blksize; 1103 1104 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1105 restart: 1106 VI_LOCK(vp); 1107 bo = &vp->v_bufobj; 1108 anyfreed = 1; 1109 for (;anyfreed;) { 1110 anyfreed = 0; 1111 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1112 if (bp->b_lblkno < trunclbn) 1113 continue; 1114 if (BUF_LOCK(bp, 1115 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1116 VI_MTX(vp)) == ENOLCK) 1117 goto restart; 1118 1119 bremfree(bp); 1120 bp->b_flags |= (B_INVAL | B_RELBUF); 1121 bp->b_flags &= ~B_ASYNC; 1122 brelse(bp); 1123 anyfreed = 1; 1124 1125 if (nbp != NULL && 1126 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1127 (nbp->b_vp != vp) || 1128 (nbp->b_flags & B_DELWRI))) { 1129 goto restart; 1130 } 1131 VI_LOCK(vp); 1132 } 1133 1134 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1135 if (bp->b_lblkno < trunclbn) 1136 continue; 1137 if (BUF_LOCK(bp, 1138 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1139 VI_MTX(vp)) == ENOLCK) 1140 goto restart; 1141 bremfree(bp); 1142 bp->b_flags |= (B_INVAL | B_RELBUF); 1143 bp->b_flags &= ~B_ASYNC; 1144 brelse(bp); 1145 anyfreed = 1; 1146 if (nbp != NULL && 1147 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1148 (nbp->b_vp != vp) || 1149 (nbp->b_flags & B_DELWRI) == 0)) { 1150 goto restart; 1151 } 1152 VI_LOCK(vp); 1153 } 1154 } 1155 1156 if (length > 0) { 1157 restartsync: 1158 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1159 if (bp->b_lblkno > 0) 1160 continue; 1161 /* 1162 * Since we hold the vnode lock this should only 1163 * fail if we're racing with the buf daemon. 1164 */ 1165 if (BUF_LOCK(bp, 1166 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1167 VI_MTX(vp)) == ENOLCK) { 1168 goto restart; 1169 } 1170 KASSERT((bp->b_flags & B_DELWRI), 1171 ("buf(%p) on dirty queue without DELWRI", bp)); 1172 1173 bremfree(bp); 1174 bawrite(bp); 1175 VI_LOCK(vp); 1176 goto restartsync; 1177 } 1178 } 1179 1180 bufobj_wwait(bo, 0, 0); 1181 VI_UNLOCK(vp); 1182 vnode_pager_setsize(vp, length); 1183 1184 return (0); 1185 } 1186 1187 /* 1188 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1189 * a vnode. 1190 * 1191 * NOTE: We have to deal with the special case of a background bitmap 1192 * buffer, a situation where two buffers will have the same logical 1193 * block offset. We want (1) only the foreground buffer to be accessed 1194 * in a lookup and (2) must differentiate between the foreground and 1195 * background buffer in the splay tree algorithm because the splay 1196 * tree cannot normally handle multiple entities with the same 'index'. 1197 * We accomplish this by adding differentiating flags to the splay tree's 1198 * numerical domain. 1199 */ 1200 static 1201 struct buf * 1202 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1203 { 1204 struct buf dummy; 1205 struct buf *lefttreemax, *righttreemin, *y; 1206 1207 if (root == NULL) 1208 return (NULL); 1209 lefttreemax = righttreemin = &dummy; 1210 for (;;) { 1211 if (lblkno < root->b_lblkno || 1212 (lblkno == root->b_lblkno && 1213 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1214 if ((y = root->b_left) == NULL) 1215 break; 1216 if (lblkno < y->b_lblkno) { 1217 /* Rotate right. */ 1218 root->b_left = y->b_right; 1219 y->b_right = root; 1220 root = y; 1221 if ((y = root->b_left) == NULL) 1222 break; 1223 } 1224 /* Link into the new root's right tree. */ 1225 righttreemin->b_left = root; 1226 righttreemin = root; 1227 } else if (lblkno > root->b_lblkno || 1228 (lblkno == root->b_lblkno && 1229 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1230 if ((y = root->b_right) == NULL) 1231 break; 1232 if (lblkno > y->b_lblkno) { 1233 /* Rotate left. */ 1234 root->b_right = y->b_left; 1235 y->b_left = root; 1236 root = y; 1237 if ((y = root->b_right) == NULL) 1238 break; 1239 } 1240 /* Link into the new root's left tree. */ 1241 lefttreemax->b_right = root; 1242 lefttreemax = root; 1243 } else { 1244 break; 1245 } 1246 root = y; 1247 } 1248 /* Assemble the new root. */ 1249 lefttreemax->b_right = root->b_left; 1250 righttreemin->b_left = root->b_right; 1251 root->b_left = dummy.b_right; 1252 root->b_right = dummy.b_left; 1253 return (root); 1254 } 1255 1256 static void 1257 buf_vlist_remove(struct buf *bp) 1258 { 1259 struct buf *root; 1260 struct bufv *bv; 1261 1262 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1263 ASSERT_BO_LOCKED(bp->b_bufobj); 1264 if (bp->b_xflags & BX_VNDIRTY) 1265 bv = &bp->b_bufobj->bo_dirty; 1266 else 1267 bv = &bp->b_bufobj->bo_clean; 1268 if (bp != bv->bv_root) { 1269 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1270 KASSERT(root == bp, ("splay lookup failed in remove")); 1271 } 1272 if (bp->b_left == NULL) { 1273 root = bp->b_right; 1274 } else { 1275 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1276 root->b_right = bp->b_right; 1277 } 1278 bv->bv_root = root; 1279 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1280 bv->bv_cnt--; 1281 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1282 } 1283 1284 /* 1285 * Add the buffer to the sorted clean or dirty block list using a 1286 * splay tree algorithm. 1287 * 1288 * NOTE: xflags is passed as a constant, optimizing this inline function! 1289 */ 1290 static void 1291 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1292 { 1293 struct buf *root; 1294 struct bufv *bv; 1295 1296 ASSERT_BO_LOCKED(bo); 1297 bp->b_xflags |= xflags; 1298 if (xflags & BX_VNDIRTY) 1299 bv = &bo->bo_dirty; 1300 else 1301 bv = &bo->bo_clean; 1302 1303 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1304 if (root == NULL) { 1305 bp->b_left = NULL; 1306 bp->b_right = NULL; 1307 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1308 } else if (bp->b_lblkno < root->b_lblkno || 1309 (bp->b_lblkno == root->b_lblkno && 1310 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1311 bp->b_left = root->b_left; 1312 bp->b_right = root; 1313 root->b_left = NULL; 1314 TAILQ_INSERT_BEFORE(root, bp, b_bobufs); 1315 } else { 1316 bp->b_right = root->b_right; 1317 bp->b_left = root; 1318 root->b_right = NULL; 1319 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs); 1320 } 1321 bv->bv_cnt++; 1322 bv->bv_root = bp; 1323 } 1324 1325 /* 1326 * Lookup a buffer using the splay tree. Note that we specifically avoid 1327 * shadow buffers used in background bitmap writes. 1328 * 1329 * This code isn't quite efficient as it could be because we are maintaining 1330 * two sorted lists and do not know which list the block resides in. 1331 * 1332 * During a "make buildworld" the desired buffer is found at one of 1333 * the roots more than 60% of the time. Thus, checking both roots 1334 * before performing either splay eliminates unnecessary splays on the 1335 * first tree splayed. 1336 */ 1337 struct buf * 1338 gbincore(struct bufobj *bo, daddr_t lblkno) 1339 { 1340 struct buf *bp; 1341 1342 GIANT_REQUIRED; 1343 1344 ASSERT_BO_LOCKED(bo); 1345 if ((bp = bo->bo_clean.bv_root) != NULL && 1346 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1347 return (bp); 1348 if ((bp = bo->bo_dirty.bv_root) != NULL && 1349 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1350 return (bp); 1351 if ((bp = bo->bo_clean.bv_root) != NULL) { 1352 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp); 1353 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1354 return (bp); 1355 } 1356 if ((bp = bo->bo_dirty.bv_root) != NULL) { 1357 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp); 1358 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1359 return (bp); 1360 } 1361 return (NULL); 1362 } 1363 1364 /* 1365 * Associate a buffer with a vnode. 1366 */ 1367 void 1368 bgetvp(struct vnode *vp, struct buf *bp) 1369 { 1370 1371 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1372 1373 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1374 ("bgetvp: bp already attached! %p", bp)); 1375 1376 ASSERT_VI_LOCKED(vp, "bgetvp"); 1377 vholdl(vp); 1378 bp->b_vp = vp; 1379 bp->b_bufobj = &vp->v_bufobj; 1380 /* 1381 * Insert onto list for new vnode. 1382 */ 1383 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN); 1384 } 1385 1386 /* 1387 * Disassociate a buffer from a vnode. 1388 */ 1389 void 1390 brelvp(struct buf *bp) 1391 { 1392 struct bufobj *bo; 1393 struct vnode *vp; 1394 1395 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1396 1397 /* 1398 * Delete from old vnode list, if on one. 1399 */ 1400 vp = bp->b_vp; /* XXX */ 1401 bo = bp->b_bufobj; 1402 BO_LOCK(bo); 1403 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1404 buf_vlist_remove(bp); 1405 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1406 bo->bo_flag &= ~BO_ONWORKLST; 1407 mtx_lock(&sync_mtx); 1408 LIST_REMOVE(bo, bo_synclist); 1409 syncer_worklist_len--; 1410 mtx_unlock(&sync_mtx); 1411 } 1412 vdropl(vp); 1413 bp->b_vp = NULL; 1414 bp->b_bufobj = NULL; 1415 BO_UNLOCK(bo); 1416 } 1417 1418 /* 1419 * Add an item to the syncer work queue. 1420 */ 1421 static void 1422 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 1423 { 1424 int slot; 1425 1426 ASSERT_BO_LOCKED(bo); 1427 1428 mtx_lock(&sync_mtx); 1429 if (bo->bo_flag & BO_ONWORKLST) 1430 LIST_REMOVE(bo, bo_synclist); 1431 else { 1432 bo->bo_flag |= BO_ONWORKLST; 1433 syncer_worklist_len++; 1434 } 1435 1436 if (delay > syncer_maxdelay - 2) 1437 delay = syncer_maxdelay - 2; 1438 slot = (syncer_delayno + delay) & syncer_mask; 1439 1440 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 1441 mtx_unlock(&sync_mtx); 1442 } 1443 1444 static int 1445 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1446 { 1447 int error, len; 1448 1449 mtx_lock(&sync_mtx); 1450 len = syncer_worklist_len - sync_vnode_count; 1451 mtx_unlock(&sync_mtx); 1452 error = SYSCTL_OUT(req, &len, sizeof(len)); 1453 return (error); 1454 } 1455 1456 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1457 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1458 1459 struct proc *updateproc; 1460 static void sched_sync(void); 1461 static struct kproc_desc up_kp = { 1462 "syncer", 1463 sched_sync, 1464 &updateproc 1465 }; 1466 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1467 1468 static int 1469 sync_vnode(struct bufobj *bo, struct thread *td) 1470 { 1471 struct vnode *vp; 1472 struct mount *mp; 1473 1474 vp = bo->__bo_vnode; /* XXX */ 1475 if (VOP_ISLOCKED(vp, NULL) != 0) 1476 return (1); 1477 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) 1478 return (1); 1479 if (VI_TRYLOCK(vp) == 0) { 1480 vn_finished_write(mp); 1481 return (1); 1482 } 1483 /* 1484 * We use vhold in case the vnode does not 1485 * successfully sync. vhold prevents the vnode from 1486 * going away when we unlock the sync_mtx so that 1487 * we can acquire the vnode interlock. 1488 */ 1489 vholdl(vp); 1490 mtx_unlock(&sync_mtx); 1491 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td); 1492 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1493 VOP_UNLOCK(vp, 0, td); 1494 vn_finished_write(mp); 1495 VI_LOCK(vp); 1496 if ((bo->bo_flag & BO_ONWORKLST) != 0) { 1497 /* 1498 * Put us back on the worklist. The worklist 1499 * routine will remove us from our current 1500 * position and then add us back in at a later 1501 * position. 1502 */ 1503 vn_syncer_add_to_worklist(bo, syncdelay); 1504 } 1505 vdropl(vp); 1506 VI_UNLOCK(vp); 1507 mtx_lock(&sync_mtx); 1508 return (0); 1509 } 1510 1511 /* 1512 * System filesystem synchronizer daemon. 1513 */ 1514 static void 1515 sched_sync(void) 1516 { 1517 struct synclist *next; 1518 struct synclist *slp; 1519 struct bufobj *bo; 1520 long starttime; 1521 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); 1522 static int dummychan; 1523 int last_work_seen; 1524 int net_worklist_len; 1525 int syncer_final_iter; 1526 int first_printf; 1527 int error; 1528 1529 mtx_lock(&Giant); 1530 last_work_seen = 0; 1531 syncer_final_iter = 0; 1532 first_printf = 1; 1533 syncer_state = SYNCER_RUNNING; 1534 starttime = time_second; 1535 1536 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 1537 SHUTDOWN_PRI_LAST); 1538 1539 for (;;) { 1540 mtx_lock(&sync_mtx); 1541 if (syncer_state == SYNCER_FINAL_DELAY && 1542 syncer_final_iter == 0) { 1543 mtx_unlock(&sync_mtx); 1544 kthread_suspend_check(td->td_proc); 1545 mtx_lock(&sync_mtx); 1546 } 1547 net_worklist_len = syncer_worklist_len - sync_vnode_count; 1548 if (syncer_state != SYNCER_RUNNING && 1549 starttime != time_second) { 1550 if (first_printf) { 1551 printf("\nSyncing disks, vnodes remaining..."); 1552 first_printf = 0; 1553 } 1554 printf("%d ", net_worklist_len); 1555 } 1556 starttime = time_second; 1557 1558 /* 1559 * Push files whose dirty time has expired. Be careful 1560 * of interrupt race on slp queue. 1561 * 1562 * Skip over empty worklist slots when shutting down. 1563 */ 1564 do { 1565 slp = &syncer_workitem_pending[syncer_delayno]; 1566 syncer_delayno += 1; 1567 if (syncer_delayno == syncer_maxdelay) 1568 syncer_delayno = 0; 1569 next = &syncer_workitem_pending[syncer_delayno]; 1570 /* 1571 * If the worklist has wrapped since the 1572 * it was emptied of all but syncer vnodes, 1573 * switch to the FINAL_DELAY state and run 1574 * for one more second. 1575 */ 1576 if (syncer_state == SYNCER_SHUTTING_DOWN && 1577 net_worklist_len == 0 && 1578 last_work_seen == syncer_delayno) { 1579 syncer_state = SYNCER_FINAL_DELAY; 1580 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 1581 } 1582 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 1583 syncer_worklist_len > 0); 1584 1585 /* 1586 * Keep track of the last time there was anything 1587 * on the worklist other than syncer vnodes. 1588 * Return to the SHUTTING_DOWN state if any 1589 * new work appears. 1590 */ 1591 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 1592 last_work_seen = syncer_delayno; 1593 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 1594 syncer_state = SYNCER_SHUTTING_DOWN; 1595 while ((bo = LIST_FIRST(slp)) != NULL) { 1596 error = sync_vnode(bo, td); 1597 if (error == 1) { 1598 LIST_REMOVE(bo, bo_synclist); 1599 LIST_INSERT_HEAD(next, bo, bo_synclist); 1600 continue; 1601 } 1602 } 1603 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 1604 syncer_final_iter--; 1605 mtx_unlock(&sync_mtx); 1606 1607 /* 1608 * Do soft update processing. 1609 */ 1610 if (softdep_process_worklist_hook != NULL) 1611 (*softdep_process_worklist_hook)(NULL); 1612 1613 /* 1614 * The variable rushjob allows the kernel to speed up the 1615 * processing of the filesystem syncer process. A rushjob 1616 * value of N tells the filesystem syncer to process the next 1617 * N seconds worth of work on its queue ASAP. Currently rushjob 1618 * is used by the soft update code to speed up the filesystem 1619 * syncer process when the incore state is getting so far 1620 * ahead of the disk that the kernel memory pool is being 1621 * threatened with exhaustion. 1622 */ 1623 mtx_lock(&sync_mtx); 1624 if (rushjob > 0) { 1625 rushjob -= 1; 1626 mtx_unlock(&sync_mtx); 1627 continue; 1628 } 1629 mtx_unlock(&sync_mtx); 1630 /* 1631 * Just sleep for a short period if time between 1632 * iterations when shutting down to allow some I/O 1633 * to happen. 1634 * 1635 * If it has taken us less than a second to process the 1636 * current work, then wait. Otherwise start right over 1637 * again. We can still lose time if any single round 1638 * takes more than two seconds, but it does not really 1639 * matter as we are just trying to generally pace the 1640 * filesystem activity. 1641 */ 1642 if (syncer_state != SYNCER_RUNNING) 1643 tsleep(&dummychan, PPAUSE, "syncfnl", 1644 hz / SYNCER_SHUTDOWN_SPEEDUP); 1645 else if (time_second == starttime) 1646 tsleep(&lbolt, PPAUSE, "syncer", 0); 1647 } 1648 } 1649 1650 /* 1651 * Request the syncer daemon to speed up its work. 1652 * We never push it to speed up more than half of its 1653 * normal turn time, otherwise it could take over the cpu. 1654 */ 1655 int 1656 speedup_syncer() 1657 { 1658 struct thread *td; 1659 int ret = 0; 1660 1661 td = FIRST_THREAD_IN_PROC(updateproc); 1662 sleepq_remove(td, &lbolt); 1663 mtx_lock(&sync_mtx); 1664 if (rushjob < syncdelay / 2) { 1665 rushjob += 1; 1666 stat_rush_requests += 1; 1667 ret = 1; 1668 } 1669 mtx_unlock(&sync_mtx); 1670 return (ret); 1671 } 1672 1673 /* 1674 * Tell the syncer to speed up its work and run though its work 1675 * list several times, then tell it to shut down. 1676 */ 1677 static void 1678 syncer_shutdown(void *arg, int howto) 1679 { 1680 struct thread *td; 1681 1682 if (howto & RB_NOSYNC) 1683 return; 1684 td = FIRST_THREAD_IN_PROC(updateproc); 1685 sleepq_remove(td, &lbolt); 1686 mtx_lock(&sync_mtx); 1687 syncer_state = SYNCER_SHUTTING_DOWN; 1688 rushjob = 0; 1689 mtx_unlock(&sync_mtx); 1690 kproc_shutdown(arg, howto); 1691 } 1692 1693 /* 1694 * Reassign a buffer from one vnode to another. 1695 * Used to assign file specific control information 1696 * (indirect blocks) to the vnode to which they belong. 1697 */ 1698 void 1699 reassignbuf(struct buf *bp) 1700 { 1701 struct vnode *vp; 1702 struct bufobj *bo; 1703 int delay; 1704 1705 vp = bp->b_vp; 1706 bo = bp->b_bufobj; 1707 ++reassignbufcalls; 1708 1709 /* 1710 * B_PAGING flagged buffers cannot be reassigned because their vp 1711 * is not fully linked in. 1712 */ 1713 if (bp->b_flags & B_PAGING) 1714 panic("cannot reassign paging buffer"); 1715 1716 /* 1717 * Delete from old vnode list, if on one. 1718 */ 1719 VI_LOCK(vp); 1720 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1721 buf_vlist_remove(bp); 1722 /* 1723 * If dirty, put on list of dirty buffers; otherwise insert onto list 1724 * of clean buffers. 1725 */ 1726 if (bp->b_flags & B_DELWRI) { 1727 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 1728 switch (vp->v_type) { 1729 case VDIR: 1730 delay = dirdelay; 1731 break; 1732 case VCHR: 1733 delay = metadelay; 1734 break; 1735 default: 1736 delay = filedelay; 1737 } 1738 vn_syncer_add_to_worklist(bo, delay); 1739 } 1740 buf_vlist_add(bp, bo, BX_VNDIRTY); 1741 } else { 1742 buf_vlist_add(bp, bo, BX_VNCLEAN); 1743 1744 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1745 mtx_lock(&sync_mtx); 1746 LIST_REMOVE(bo, bo_synclist); 1747 syncer_worklist_len--; 1748 mtx_unlock(&sync_mtx); 1749 bo->bo_flag &= ~BO_ONWORKLST; 1750 } 1751 } 1752 VI_UNLOCK(vp); 1753 } 1754 1755 /* 1756 * Create a vnode for a device. 1757 * Used for mounting the root filesystem. 1758 */ 1759 int 1760 bdevvp(dev, vpp) 1761 struct cdev *dev; 1762 struct vnode **vpp; 1763 { 1764 register struct vnode *vp; 1765 struct vnode *nvp; 1766 int error; 1767 1768 if (dev == NULL) { 1769 *vpp = NULLVP; 1770 return (ENXIO); 1771 } 1772 if (vfinddev(dev, vpp)) 1773 return (0); 1774 1775 error = getnewvnode("none", (struct mount *)0, devfs_specop_p, &nvp); 1776 if (error) { 1777 *vpp = NULLVP; 1778 return (error); 1779 } 1780 vp = nvp; 1781 vp->v_type = VCHR; 1782 vp->v_bufobj.bo_bsize = DEV_BSIZE; 1783 addalias(vp, dev); 1784 *vpp = vp; 1785 return (0); 1786 } 1787 1788 static void 1789 v_incr_usecount(struct vnode *vp, int delta) 1790 { 1791 1792 vp->v_usecount += delta; 1793 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1794 dev_lock(); 1795 vp->v_rdev->si_usecount += delta; 1796 dev_unlock(); 1797 } 1798 } 1799 1800 /* 1801 * Add vnode to the alias list hung off the struct cdev *. 1802 * 1803 * The reason for this gunk is that multiple vnodes can reference 1804 * the same physical device, so checking vp->v_usecount to see 1805 * how many users there are is inadequate; the v_usecount for 1806 * the vnodes need to be accumulated. vcount() does that. 1807 */ 1808 struct vnode * 1809 addaliasu(nvp, nvp_rdev) 1810 struct vnode *nvp; 1811 dev_t nvp_rdev; 1812 { 1813 struct vnode *ovp; 1814 vop_t **ops; 1815 struct cdev *dev; 1816 1817 if (nvp->v_type == VBLK) 1818 return (nvp); 1819 if (nvp->v_type != VCHR) 1820 panic("addaliasu on non-special vnode"); 1821 dev = findcdev(nvp_rdev); 1822 if (dev == NULL) 1823 return (nvp); 1824 /* 1825 * Check to see if we have a bdevvp vnode with no associated 1826 * filesystem. If so, we want to associate the filesystem of 1827 * the new newly instigated vnode with the bdevvp vnode and 1828 * discard the newly created vnode rather than leaving the 1829 * bdevvp vnode lying around with no associated filesystem. 1830 */ 1831 if (vfinddev(dev, &ovp) == 0 || ovp->v_data != NULL) { 1832 addalias(nvp, dev); 1833 return (nvp); 1834 } 1835 /* 1836 * Discard unneeded vnode, but save its node specific data. 1837 * Note that if there is a lock, it is carried over in the 1838 * node specific data to the replacement vnode. 1839 */ 1840 vref(ovp); 1841 ovp->v_data = nvp->v_data; 1842 ovp->v_tag = nvp->v_tag; 1843 nvp->v_data = NULL; 1844 lockdestroy(ovp->v_vnlock); 1845 lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, 1846 nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); 1847 ops = ovp->v_op; 1848 ovp->v_op = nvp->v_op; 1849 if (VOP_ISLOCKED(nvp, curthread)) { 1850 VOP_UNLOCK(nvp, 0, curthread); 1851 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 1852 } 1853 nvp->v_op = ops; 1854 delmntque(ovp); 1855 insmntque(ovp, nvp->v_mount); 1856 vrele(nvp); 1857 vgone(nvp); 1858 return (ovp); 1859 } 1860 1861 /* This is a local helper function that do the same as addaliasu, but for a 1862 * struct cdev *instead of an dev_t. */ 1863 static void 1864 addalias(nvp, dev) 1865 struct vnode *nvp; 1866 struct cdev *dev; 1867 { 1868 1869 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 1870 VI_LOCK(nvp); 1871 dev_lock(); 1872 dev->si_refcount++; 1873 nvp->v_rdev = dev; 1874 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 1875 dev->si_usecount += nvp->v_usecount; 1876 dev_unlock(); 1877 VI_UNLOCK(nvp); 1878 } 1879 1880 /* 1881 * Grab a particular vnode from the free list, increment its 1882 * reference count and lock it. The vnode lock bit is set if the 1883 * vnode is being eliminated in vgone. The process is awakened 1884 * when the transition is completed, and an error returned to 1885 * indicate that the vnode is no longer usable (possibly having 1886 * been changed to a new filesystem type). 1887 */ 1888 int 1889 vget(vp, flags, td) 1890 register struct vnode *vp; 1891 int flags; 1892 struct thread *td; 1893 { 1894 int error; 1895 1896 /* 1897 * If the vnode is in the process of being cleaned out for 1898 * another use, we wait for the cleaning to finish and then 1899 * return failure. Cleaning is determined by checking that 1900 * the VI_XLOCK flag is set. 1901 */ 1902 if ((flags & LK_INTERLOCK) == 0) 1903 VI_LOCK(vp); 1904 if (vp->v_iflag & VI_XLOCK && vp->v_vxthread != curthread) { 1905 if ((flags & LK_NOWAIT) == 0) { 1906 vp->v_iflag |= VI_XWANT; 1907 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); 1908 return (ENOENT); 1909 } 1910 VI_UNLOCK(vp); 1911 return (EBUSY); 1912 } 1913 1914 v_incr_usecount(vp, 1); 1915 1916 if (VSHOULDBUSY(vp)) 1917 vbusy(vp); 1918 if (flags & LK_TYPE_MASK) { 1919 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 1920 /* 1921 * must expand vrele here because we do not want 1922 * to call VOP_INACTIVE if the reference count 1923 * drops back to zero since it was never really 1924 * active. We must remove it from the free list 1925 * before sleeping so that multiple processes do 1926 * not try to recycle it. 1927 */ 1928 VI_LOCK(vp); 1929 v_incr_usecount(vp, -1); 1930 if (VSHOULDFREE(vp)) 1931 vfree(vp); 1932 else 1933 vlruvp(vp); 1934 VI_UNLOCK(vp); 1935 } 1936 return (error); 1937 } 1938 VI_UNLOCK(vp); 1939 return (0); 1940 } 1941 1942 /* 1943 * Increase the reference count of a vnode. 1944 */ 1945 void 1946 vref(struct vnode *vp) 1947 { 1948 1949 VI_LOCK(vp); 1950 v_incr_usecount(vp, 1); 1951 VI_UNLOCK(vp); 1952 } 1953 1954 /* 1955 * Return reference count of a vnode. 1956 * 1957 * The results of this call are only guaranteed when some mechanism other 1958 * than the VI lock is used to stop other processes from gaining references 1959 * to the vnode. This may be the case if the caller holds the only reference. 1960 * This is also useful when stale data is acceptable as race conditions may 1961 * be accounted for by some other means. 1962 */ 1963 int 1964 vrefcnt(struct vnode *vp) 1965 { 1966 int usecnt; 1967 1968 VI_LOCK(vp); 1969 usecnt = vp->v_usecount; 1970 VI_UNLOCK(vp); 1971 1972 return (usecnt); 1973 } 1974 1975 1976 /* 1977 * Vnode put/release. 1978 * If count drops to zero, call inactive routine and return to freelist. 1979 */ 1980 void 1981 vrele(vp) 1982 struct vnode *vp; 1983 { 1984 struct thread *td = curthread; /* XXX */ 1985 1986 GIANT_REQUIRED; 1987 1988 KASSERT(vp != NULL, ("vrele: null vp")); 1989 1990 VI_LOCK(vp); 1991 1992 /* Skip this v_writecount check if we're going to panic below. */ 1993 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 1994 ("vrele: missed vn_close")); 1995 1996 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 1997 vp->v_usecount == 1)) { 1998 v_incr_usecount(vp, -1); 1999 VI_UNLOCK(vp); 2000 2001 return; 2002 } 2003 2004 if (vp->v_usecount == 1) { 2005 v_incr_usecount(vp, -1); 2006 /* 2007 * We must call VOP_INACTIVE with the node locked. Mark 2008 * as VI_DOINGINACT to avoid recursion. 2009 */ 2010 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 2011 VI_LOCK(vp); 2012 vp->v_iflag |= VI_DOINGINACT; 2013 VI_UNLOCK(vp); 2014 VOP_INACTIVE(vp, td); 2015 VI_LOCK(vp); 2016 KASSERT(vp->v_iflag & VI_DOINGINACT, 2017 ("vrele: lost VI_DOINGINACT")); 2018 vp->v_iflag &= ~VI_DOINGINACT; 2019 } else 2020 VI_LOCK(vp); 2021 if (VSHOULDFREE(vp)) 2022 vfree(vp); 2023 else 2024 vlruvp(vp); 2025 VI_UNLOCK(vp); 2026 2027 } else { 2028 #ifdef DIAGNOSTIC 2029 vprint("vrele: negative ref count", vp); 2030 #endif 2031 VI_UNLOCK(vp); 2032 panic("vrele: negative ref cnt"); 2033 } 2034 } 2035 2036 /* 2037 * Release an already locked vnode. This give the same effects as 2038 * unlock+vrele(), but takes less time and avoids releasing and 2039 * re-aquiring the lock (as vrele() aquires the lock internally.) 2040 */ 2041 void 2042 vput(vp) 2043 struct vnode *vp; 2044 { 2045 struct thread *td = curthread; /* XXX */ 2046 2047 GIANT_REQUIRED; 2048 2049 KASSERT(vp != NULL, ("vput: null vp")); 2050 VI_LOCK(vp); 2051 /* Skip this v_writecount check if we're going to panic below. */ 2052 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2053 ("vput: missed vn_close")); 2054 2055 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2056 vp->v_usecount == 1)) { 2057 v_incr_usecount(vp, -1); 2058 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2059 return; 2060 } 2061 2062 if (vp->v_usecount == 1) { 2063 v_incr_usecount(vp, -1); 2064 /* 2065 * We must call VOP_INACTIVE with the node locked, so 2066 * we just need to release the vnode mutex. Mark as 2067 * as VI_DOINGINACT to avoid recursion. 2068 */ 2069 vp->v_iflag |= VI_DOINGINACT; 2070 VI_UNLOCK(vp); 2071 VOP_INACTIVE(vp, td); 2072 VI_LOCK(vp); 2073 KASSERT(vp->v_iflag & VI_DOINGINACT, 2074 ("vput: lost VI_DOINGINACT")); 2075 vp->v_iflag &= ~VI_DOINGINACT; 2076 if (VSHOULDFREE(vp)) 2077 vfree(vp); 2078 else 2079 vlruvp(vp); 2080 VI_UNLOCK(vp); 2081 2082 } else { 2083 #ifdef DIAGNOSTIC 2084 vprint("vput: negative ref count", vp); 2085 #endif 2086 panic("vput: negative ref cnt"); 2087 } 2088 } 2089 2090 /* 2091 * Somebody doesn't want the vnode recycled. 2092 */ 2093 void 2094 vhold(struct vnode *vp) 2095 { 2096 2097 VI_LOCK(vp); 2098 vholdl(vp); 2099 VI_UNLOCK(vp); 2100 } 2101 2102 void 2103 vholdl(struct vnode *vp) 2104 { 2105 2106 vp->v_holdcnt++; 2107 if (VSHOULDBUSY(vp)) 2108 vbusy(vp); 2109 } 2110 2111 /* 2112 * Note that there is one less who cares about this vnode. vdrop() is the 2113 * opposite of vhold(). 2114 */ 2115 void 2116 vdrop(struct vnode *vp) 2117 { 2118 2119 VI_LOCK(vp); 2120 vdropl(vp); 2121 VI_UNLOCK(vp); 2122 } 2123 2124 void 2125 vdropl(vp) 2126 register struct vnode *vp; 2127 { 2128 2129 if (vp->v_holdcnt <= 0) 2130 panic("vdrop: holdcnt"); 2131 vp->v_holdcnt--; 2132 if (VSHOULDFREE(vp)) 2133 vfree(vp); 2134 else 2135 vlruvp(vp); 2136 } 2137 2138 /* 2139 * Remove any vnodes in the vnode table belonging to mount point mp. 2140 * 2141 * If FORCECLOSE is not specified, there should not be any active ones, 2142 * return error if any are found (nb: this is a user error, not a 2143 * system error). If FORCECLOSE is specified, detach any active vnodes 2144 * that are found. 2145 * 2146 * If WRITECLOSE is set, only flush out regular file vnodes open for 2147 * writing. 2148 * 2149 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2150 * 2151 * `rootrefs' specifies the base reference count for the root vnode 2152 * of this filesystem. The root vnode is considered busy if its 2153 * v_usecount exceeds this value. On a successful return, vflush(, td) 2154 * will call vrele() on the root vnode exactly rootrefs times. 2155 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2156 * be zero. 2157 */ 2158 #ifdef DIAGNOSTIC 2159 static int busyprt = 0; /* print out busy vnodes */ 2160 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2161 #endif 2162 2163 int 2164 vflush(mp, rootrefs, flags, td) 2165 struct mount *mp; 2166 int rootrefs; 2167 int flags; 2168 struct thread *td; 2169 { 2170 struct vnode *vp, *nvp, *rootvp = NULL; 2171 struct vattr vattr; 2172 int busy = 0, error; 2173 2174 if (rootrefs > 0) { 2175 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2176 ("vflush: bad args")); 2177 /* 2178 * Get the filesystem root vnode. We can vput() it 2179 * immediately, since with rootrefs > 0, it won't go away. 2180 */ 2181 if ((error = VFS_ROOT(mp, &rootvp, td)) != 0) 2182 return (error); 2183 vput(rootvp); 2184 2185 } 2186 MNT_ILOCK(mp); 2187 loop: 2188 MNT_VNODE_FOREACH(vp, mp, nvp) { 2189 2190 VI_LOCK(vp); 2191 MNT_IUNLOCK(mp); 2192 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td); 2193 if (error) { 2194 MNT_ILOCK(mp); 2195 goto loop; 2196 } 2197 /* 2198 * Skip over a vnodes marked VV_SYSTEM. 2199 */ 2200 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2201 VOP_UNLOCK(vp, 0, td); 2202 MNT_ILOCK(mp); 2203 continue; 2204 } 2205 /* 2206 * If WRITECLOSE is set, flush out unlinked but still open 2207 * files (even if open only for reading) and regular file 2208 * vnodes open for writing. 2209 */ 2210 if (flags & WRITECLOSE) { 2211 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2212 VI_LOCK(vp); 2213 2214 if ((vp->v_type == VNON || 2215 (error == 0 && vattr.va_nlink > 0)) && 2216 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2217 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2218 MNT_ILOCK(mp); 2219 continue; 2220 } 2221 } else 2222 VI_LOCK(vp); 2223 2224 VOP_UNLOCK(vp, 0, td); 2225 2226 /* 2227 * With v_usecount == 0, all we need to do is clear out the 2228 * vnode data structures and we are done. 2229 */ 2230 if (vp->v_usecount == 0) { 2231 vgonel(vp, td); 2232 MNT_ILOCK(mp); 2233 continue; 2234 } 2235 2236 /* 2237 * If FORCECLOSE is set, forcibly close the vnode. For block 2238 * or character devices, revert to an anonymous device. For 2239 * all other files, just kill them. 2240 */ 2241 if (flags & FORCECLOSE) { 2242 if (vp->v_type != VCHR) 2243 vgonel(vp, td); 2244 else 2245 vgonechrl(vp, td); 2246 MNT_ILOCK(mp); 2247 continue; 2248 } 2249 #ifdef DIAGNOSTIC 2250 if (busyprt) 2251 vprint("vflush: busy vnode", vp); 2252 #endif 2253 VI_UNLOCK(vp); 2254 MNT_ILOCK(mp); 2255 busy++; 2256 } 2257 MNT_IUNLOCK(mp); 2258 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2259 /* 2260 * If just the root vnode is busy, and if its refcount 2261 * is equal to `rootrefs', then go ahead and kill it. 2262 */ 2263 VI_LOCK(rootvp); 2264 KASSERT(busy > 0, ("vflush: not busy")); 2265 KASSERT(rootvp->v_usecount >= rootrefs, 2266 ("vflush: usecount %d < rootrefs %d", 2267 rootvp->v_usecount, rootrefs)); 2268 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2269 vgonel(rootvp, td); 2270 busy = 0; 2271 } else 2272 VI_UNLOCK(rootvp); 2273 } 2274 if (busy) 2275 return (EBUSY); 2276 for (; rootrefs > 0; rootrefs--) 2277 vrele(rootvp); 2278 return (0); 2279 } 2280 2281 /* 2282 * This moves a now (likely recyclable) vnode to the end of the 2283 * mountlist. XXX However, it is temporarily disabled until we 2284 * can clean up ffs_sync() and friends, which have loop restart 2285 * conditions which this code causes to operate O(N^2). 2286 */ 2287 static void 2288 vlruvp(struct vnode *vp) 2289 { 2290 #if 0 2291 struct mount *mp; 2292 2293 if ((mp = vp->v_mount) != NULL) { 2294 MNT_ILOCK(mp); 2295 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2296 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2297 MNT_IUNLOCK(mp); 2298 } 2299 #endif 2300 } 2301 2302 static void 2303 vx_lock(struct vnode *vp) 2304 { 2305 2306 ASSERT_VI_LOCKED(vp, "vx_lock"); 2307 2308 /* 2309 * Prevent the vnode from being recycled or brought into use while we 2310 * clean it out. 2311 */ 2312 if (vp->v_iflag & VI_XLOCK) 2313 panic("vclean: deadlock"); 2314 vp->v_iflag |= VI_XLOCK; 2315 vp->v_vxthread = curthread; 2316 } 2317 2318 static void 2319 vx_unlock(struct vnode *vp) 2320 { 2321 ASSERT_VI_LOCKED(vp, "vx_unlock"); 2322 vp->v_iflag &= ~VI_XLOCK; 2323 vp->v_vxthread = NULL; 2324 if (vp->v_iflag & VI_XWANT) { 2325 vp->v_iflag &= ~VI_XWANT; 2326 wakeup(vp); 2327 } 2328 } 2329 2330 /* 2331 * Disassociate the underlying filesystem from a vnode. 2332 */ 2333 static void 2334 vclean(vp, flags, td) 2335 struct vnode *vp; 2336 int flags; 2337 struct thread *td; 2338 { 2339 int active; 2340 2341 ASSERT_VI_LOCKED(vp, "vclean"); 2342 /* 2343 * Check to see if the vnode is in use. If so we have to reference it 2344 * before we clean it out so that its count cannot fall to zero and 2345 * generate a race against ourselves to recycle it. 2346 */ 2347 if ((active = vp->v_usecount)) 2348 v_incr_usecount(vp, 1); 2349 2350 /* 2351 * Even if the count is zero, the VOP_INACTIVE routine may still 2352 * have the object locked while it cleans it out. The VOP_LOCK 2353 * ensures that the VOP_INACTIVE routine is done with its work. 2354 * For active vnodes, it ensures that no other activity can 2355 * occur while the underlying object is being cleaned out. 2356 */ 2357 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2358 2359 /* 2360 * Clean out any buffers associated with the vnode. 2361 * If the flush fails, just toss the buffers. 2362 */ 2363 if (flags & DOCLOSE) { 2364 struct buf *bp; 2365 bp = TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd); 2366 if (bp != NULL) 2367 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2368 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2369 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2370 } 2371 2372 VOP_DESTROYVOBJECT(vp); 2373 2374 /* 2375 * Any other processes trying to obtain this lock must first 2376 * wait for VXLOCK to clear, then call the new lock operation. 2377 */ 2378 VOP_UNLOCK(vp, 0, td); 2379 2380 /* 2381 * If purging an active vnode, it must be closed and 2382 * deactivated before being reclaimed. Note that the 2383 * VOP_INACTIVE will unlock the vnode. 2384 */ 2385 if (active) { 2386 if (flags & DOCLOSE) 2387 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2388 VI_LOCK(vp); 2389 if ((vp->v_iflag & VI_DOINGINACT) == 0) { 2390 vp->v_iflag |= VI_DOINGINACT; 2391 VI_UNLOCK(vp); 2392 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2393 panic("vclean: cannot relock."); 2394 VOP_INACTIVE(vp, td); 2395 VI_LOCK(vp); 2396 KASSERT(vp->v_iflag & VI_DOINGINACT, 2397 ("vclean: lost VI_DOINGINACT")); 2398 vp->v_iflag &= ~VI_DOINGINACT; 2399 } 2400 VI_UNLOCK(vp); 2401 } 2402 /* 2403 * Reclaim the vnode. 2404 */ 2405 if (VOP_RECLAIM(vp, td)) 2406 panic("vclean: cannot reclaim"); 2407 2408 if (active) { 2409 /* 2410 * Inline copy of vrele() since VOP_INACTIVE 2411 * has already been called. 2412 */ 2413 VI_LOCK(vp); 2414 v_incr_usecount(vp, -1); 2415 if (vp->v_usecount <= 0) { 2416 #ifdef INVARIANTS 2417 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2418 vprint("vclean: bad ref count", vp); 2419 panic("vclean: ref cnt"); 2420 } 2421 #endif 2422 if (VSHOULDFREE(vp)) 2423 vfree(vp); 2424 } 2425 VI_UNLOCK(vp); 2426 } 2427 /* 2428 * Delete from old mount point vnode list. 2429 */ 2430 delmntque(vp); 2431 cache_purge(vp); 2432 VI_LOCK(vp); 2433 if (VSHOULDFREE(vp)) 2434 vfree(vp); 2435 2436 /* 2437 * Done with purge, reset to the standard lock and 2438 * notify sleepers of the grim news. 2439 */ 2440 vp->v_vnlock = &vp->v_lock; 2441 vp->v_op = dead_vnodeop_p; 2442 if (vp->v_pollinfo != NULL) 2443 vn_pollgone(vp); 2444 vp->v_tag = "none"; 2445 } 2446 2447 /* 2448 * Recycle an unused vnode to the front of the free list. 2449 * Release the passed interlock if the vnode will be recycled. 2450 */ 2451 int 2452 vrecycle(vp, inter_lkp, td) 2453 struct vnode *vp; 2454 struct mtx *inter_lkp; 2455 struct thread *td; 2456 { 2457 2458 VI_LOCK(vp); 2459 if (vp->v_usecount == 0) { 2460 if (inter_lkp) { 2461 mtx_unlock(inter_lkp); 2462 } 2463 vgonel(vp, td); 2464 return (1); 2465 } 2466 VI_UNLOCK(vp); 2467 return (0); 2468 } 2469 2470 /* 2471 * Eliminate all activity associated with a vnode 2472 * in preparation for reuse. 2473 */ 2474 void 2475 vgone(vp) 2476 register struct vnode *vp; 2477 { 2478 struct thread *td = curthread; /* XXX */ 2479 2480 VI_LOCK(vp); 2481 vgonel(vp, td); 2482 } 2483 2484 /* 2485 * Disassociate a character device from the its underlying filesystem and 2486 * attach it to spec. This is for use when the chr device is still active 2487 * and the filesystem is going away. 2488 */ 2489 static void 2490 vgonechrl(struct vnode *vp, struct thread *td) 2491 { 2492 ASSERT_VI_LOCKED(vp, "vgonechrl"); 2493 vx_lock(vp); 2494 /* 2495 * This is a custom version of vclean() which does not tearm down 2496 * the bufs or vm objects held by this vnode. This allows filesystems 2497 * to continue using devices which were discovered via another 2498 * filesystem that has been unmounted. 2499 */ 2500 if (vp->v_usecount != 0) { 2501 v_incr_usecount(vp, 1); 2502 /* 2503 * Ensure that no other activity can occur while the 2504 * underlying object is being cleaned out. 2505 */ 2506 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2507 /* 2508 * Any other processes trying to obtain this lock must first 2509 * wait for VXLOCK to clear, then call the new lock operation. 2510 */ 2511 VOP_UNLOCK(vp, 0, td); 2512 vp->v_vnlock = &vp->v_lock; 2513 vp->v_tag = "orphanchr"; 2514 vp->v_op = devfs_specop_p; 2515 delmntque(vp); 2516 cache_purge(vp); 2517 vrele(vp); 2518 VI_LOCK(vp); 2519 } else 2520 vclean(vp, 0, td); 2521 vp->v_op = devfs_specop_p; 2522 vx_unlock(vp); 2523 VI_UNLOCK(vp); 2524 } 2525 2526 /* 2527 * vgone, with the vp interlock held. 2528 */ 2529 void 2530 vgonel(vp, td) 2531 struct vnode *vp; 2532 struct thread *td; 2533 { 2534 /* 2535 * If a vgone (or vclean) is already in progress, 2536 * wait until it is done and return. 2537 */ 2538 ASSERT_VI_LOCKED(vp, "vgonel"); 2539 if (vp->v_iflag & VI_XLOCK) { 2540 vp->v_iflag |= VI_XWANT; 2541 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); 2542 return; 2543 } 2544 vx_lock(vp); 2545 2546 /* 2547 * Clean out the filesystem specific data. 2548 */ 2549 vclean(vp, DOCLOSE, td); 2550 VI_UNLOCK(vp); 2551 2552 /* 2553 * If special device, remove it from special device alias list 2554 * if it is on one. 2555 */ 2556 VI_LOCK(vp); 2557 if (vp->v_type == VCHR && vp->v_rdev != NULL) 2558 dev_rel(vp); 2559 2560 /* 2561 * If it is on the freelist and not already at the head, 2562 * move it to the head of the list. The test of the 2563 * VDOOMED flag and the reference count of zero is because 2564 * it will be removed from the free list by getnewvnode, 2565 * but will not have its reference count incremented until 2566 * after calling vgone. If the reference count were 2567 * incremented first, vgone would (incorrectly) try to 2568 * close the previous instance of the underlying object. 2569 */ 2570 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2571 mtx_lock(&vnode_free_list_mtx); 2572 if (vp->v_iflag & VI_FREE) { 2573 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2574 } else { 2575 vp->v_iflag |= VI_FREE; 2576 freevnodes++; 2577 } 2578 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2579 mtx_unlock(&vnode_free_list_mtx); 2580 } 2581 2582 vp->v_type = VBAD; 2583 vx_unlock(vp); 2584 VI_UNLOCK(vp); 2585 } 2586 2587 /* 2588 * Lookup a vnode by device number. 2589 */ 2590 int 2591 vfinddev(dev, vpp) 2592 struct cdev *dev; 2593 struct vnode **vpp; 2594 { 2595 struct vnode *vp; 2596 2597 dev_lock(); 2598 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2599 *vpp = vp; 2600 dev_unlock(); 2601 return (1); 2602 } 2603 dev_unlock(); 2604 return (0); 2605 } 2606 2607 /* 2608 * Calculate the total number of references to a special device. 2609 */ 2610 int 2611 vcount(vp) 2612 struct vnode *vp; 2613 { 2614 int count; 2615 2616 dev_lock(); 2617 count = vp->v_rdev->si_usecount; 2618 dev_unlock(); 2619 return (count); 2620 } 2621 2622 /* 2623 * Same as above, but using the struct cdev *as argument 2624 */ 2625 int 2626 count_dev(dev) 2627 struct cdev *dev; 2628 { 2629 int count; 2630 2631 dev_lock(); 2632 count = dev->si_usecount; 2633 dev_unlock(); 2634 return(count); 2635 } 2636 2637 /* 2638 * Print out a description of a vnode. 2639 */ 2640 static char *typename[] = 2641 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2642 2643 void 2644 vprint(label, vp) 2645 char *label; 2646 struct vnode *vp; 2647 { 2648 char buf[96]; 2649 2650 if (label != NULL) 2651 printf("%s: %p: ", label, (void *)vp); 2652 else 2653 printf("%p: ", (void *)vp); 2654 printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", 2655 vp->v_tag, typename[vp->v_type], vp->v_usecount, 2656 vp->v_writecount, vp->v_holdcnt); 2657 buf[0] = '\0'; 2658 if (vp->v_vflag & VV_ROOT) 2659 strcat(buf, "|VV_ROOT"); 2660 if (vp->v_vflag & VV_TEXT) 2661 strcat(buf, "|VV_TEXT"); 2662 if (vp->v_vflag & VV_SYSTEM) 2663 strcat(buf, "|VV_SYSTEM"); 2664 if (vp->v_iflag & VI_XLOCK) 2665 strcat(buf, "|VI_XLOCK"); 2666 if (vp->v_iflag & VI_XWANT) 2667 strcat(buf, "|VI_XWANT"); 2668 if (vp->v_iflag & VI_DOOMED) 2669 strcat(buf, "|VI_DOOMED"); 2670 if (vp->v_iflag & VI_FREE) 2671 strcat(buf, "|VI_FREE"); 2672 if (vp->v_vflag & VV_OBJBUF) 2673 strcat(buf, "|VV_OBJBUF"); 2674 if (buf[0] != '\0') 2675 printf(" flags (%s),", &buf[1]); 2676 lockmgr_printinfo(vp->v_vnlock); 2677 printf("\n"); 2678 if (vp->v_data != NULL) 2679 VOP_PRINT(vp); 2680 } 2681 2682 #ifdef DDB 2683 #include <ddb/ddb.h> 2684 /* 2685 * List all of the locked vnodes in the system. 2686 * Called when debugging the kernel. 2687 */ 2688 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2689 { 2690 struct mount *mp, *nmp; 2691 struct vnode *vp; 2692 2693 /* 2694 * Note: because this is DDB, we can't obey the locking semantics 2695 * for these structures, which means we could catch an inconsistent 2696 * state and dereference a nasty pointer. Not much to be done 2697 * about that. 2698 */ 2699 printf("Locked vnodes\n"); 2700 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2701 nmp = TAILQ_NEXT(mp, mnt_list); 2702 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2703 if (VOP_ISLOCKED(vp, NULL)) 2704 vprint(NULL, vp); 2705 } 2706 nmp = TAILQ_NEXT(mp, mnt_list); 2707 } 2708 } 2709 #endif 2710 2711 /* 2712 * Fill in a struct xvfsconf based on a struct vfsconf. 2713 */ 2714 static void 2715 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2716 { 2717 2718 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2719 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2720 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2721 xvfsp->vfc_flags = vfsp->vfc_flags; 2722 /* 2723 * These are unused in userland, we keep them 2724 * to not break binary compatibility. 2725 */ 2726 xvfsp->vfc_vfsops = NULL; 2727 xvfsp->vfc_next = NULL; 2728 } 2729 2730 /* 2731 * Top level filesystem related information gathering. 2732 */ 2733 static int 2734 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2735 { 2736 struct vfsconf *vfsp; 2737 struct xvfsconf xvfsp; 2738 int error; 2739 2740 error = 0; 2741 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2742 vfsconf2x(vfsp, &xvfsp); 2743 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); 2744 if (error) 2745 break; 2746 } 2747 return (error); 2748 } 2749 2750 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2751 "S,xvfsconf", "List of all configured filesystems"); 2752 2753 #ifndef BURN_BRIDGES 2754 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2755 2756 static int 2757 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2758 { 2759 int *name = (int *)arg1 - 1; /* XXX */ 2760 u_int namelen = arg2 + 1; /* XXX */ 2761 struct vfsconf *vfsp; 2762 struct xvfsconf xvfsp; 2763 2764 printf("WARNING: userland calling deprecated sysctl, " 2765 "please rebuild world\n"); 2766 2767 #if 1 || defined(COMPAT_PRELITE2) 2768 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2769 if (namelen == 1) 2770 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2771 #endif 2772 2773 switch (name[1]) { 2774 case VFS_MAXTYPENUM: 2775 if (namelen != 2) 2776 return (ENOTDIR); 2777 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2778 case VFS_CONF: 2779 if (namelen != 3) 2780 return (ENOTDIR); /* overloaded */ 2781 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 2782 if (vfsp->vfc_typenum == name[2]) 2783 break; 2784 if (vfsp == NULL) 2785 return (EOPNOTSUPP); 2786 vfsconf2x(vfsp, &xvfsp); 2787 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2788 } 2789 return (EOPNOTSUPP); 2790 } 2791 2792 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 2793 "Generic filesystem"); 2794 2795 #if 1 || defined(COMPAT_PRELITE2) 2796 2797 static int 2798 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2799 { 2800 int error; 2801 struct vfsconf *vfsp; 2802 struct ovfsconf ovfs; 2803 2804 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2805 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2806 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2807 ovfs.vfc_index = vfsp->vfc_typenum; 2808 ovfs.vfc_refcount = vfsp->vfc_refcount; 2809 ovfs.vfc_flags = vfsp->vfc_flags; 2810 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2811 if (error) 2812 return error; 2813 } 2814 return 0; 2815 } 2816 2817 #endif /* 1 || COMPAT_PRELITE2 */ 2818 #endif /* !BURN_BRIDGES */ 2819 2820 #define KINFO_VNODESLOP 10 2821 #ifdef notyet 2822 /* 2823 * Dump vnode list (via sysctl). 2824 */ 2825 /* ARGSUSED */ 2826 static int 2827 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2828 { 2829 struct xvnode *xvn; 2830 struct thread *td = req->td; 2831 struct mount *mp; 2832 struct vnode *vp; 2833 int error, len, n; 2834 2835 /* 2836 * Stale numvnodes access is not fatal here. 2837 */ 2838 req->lock = 0; 2839 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 2840 if (!req->oldptr) 2841 /* Make an estimate */ 2842 return (SYSCTL_OUT(req, 0, len)); 2843 2844 error = sysctl_wire_old_buffer(req, 0); 2845 if (error != 0) 2846 return (error); 2847 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 2848 n = 0; 2849 mtx_lock(&mountlist_mtx); 2850 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2851 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 2852 continue; 2853 MNT_ILOCK(mp); 2854 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2855 if (n == len) 2856 break; 2857 vref(vp); 2858 xvn[n].xv_size = sizeof *xvn; 2859 xvn[n].xv_vnode = vp; 2860 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 2861 XV_COPY(usecount); 2862 XV_COPY(writecount); 2863 XV_COPY(holdcnt); 2864 XV_COPY(id); 2865 XV_COPY(mount); 2866 XV_COPY(numoutput); 2867 XV_COPY(type); 2868 #undef XV_COPY 2869 xvn[n].xv_flag = vp->v_vflag; 2870 2871 switch (vp->v_type) { 2872 case VREG: 2873 case VDIR: 2874 case VLNK: 2875 break; 2876 case VBLK: 2877 case VCHR: 2878 if (vp->v_rdev == NULL) { 2879 vrele(vp); 2880 continue; 2881 } 2882 xvn[n].xv_dev = dev2udev(vp->v_rdev); 2883 break; 2884 case VSOCK: 2885 xvn[n].xv_socket = vp->v_socket; 2886 break; 2887 case VFIFO: 2888 xvn[n].xv_fifo = vp->v_fifoinfo; 2889 break; 2890 case VNON: 2891 case VBAD: 2892 default: 2893 /* shouldn't happen? */ 2894 vrele(vp); 2895 continue; 2896 } 2897 vrele(vp); 2898 ++n; 2899 } 2900 MNT_IUNLOCK(mp); 2901 mtx_lock(&mountlist_mtx); 2902 vfs_unbusy(mp, td); 2903 if (n == len) 2904 break; 2905 } 2906 mtx_unlock(&mountlist_mtx); 2907 2908 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 2909 free(xvn, M_TEMP); 2910 return (error); 2911 } 2912 2913 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2914 0, 0, sysctl_vnode, "S,xvnode", ""); 2915 #endif 2916 2917 /* 2918 * Unmount all filesystems. The list is traversed in reverse order 2919 * of mounting to avoid dependencies. 2920 */ 2921 void 2922 vfs_unmountall() 2923 { 2924 struct mount *mp; 2925 struct thread *td; 2926 int error; 2927 2928 if (curthread != NULL) 2929 td = curthread; 2930 else 2931 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 2932 /* 2933 * Since this only runs when rebooting, it is not interlocked. 2934 */ 2935 while(!TAILQ_EMPTY(&mountlist)) { 2936 mp = TAILQ_LAST(&mountlist, mntlist); 2937 error = dounmount(mp, MNT_FORCE, td); 2938 if (error) { 2939 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2940 printf("unmount of %s failed (", 2941 mp->mnt_stat.f_mntonname); 2942 if (error == EBUSY) 2943 printf("BUSY)\n"); 2944 else 2945 printf("%d)\n", error); 2946 } else { 2947 /* The unmount has removed mp from the mountlist */ 2948 } 2949 } 2950 } 2951 2952 /* 2953 * perform msync on all vnodes under a mount point 2954 * the mount point must be locked. 2955 */ 2956 void 2957 vfs_msync(struct mount *mp, int flags) 2958 { 2959 struct vnode *vp, *nvp; 2960 struct vm_object *obj; 2961 int tries; 2962 2963 GIANT_REQUIRED; 2964 2965 tries = 5; 2966 MNT_ILOCK(mp); 2967 loop: 2968 TAILQ_FOREACH_SAFE(vp, &mp->mnt_nvnodelist, v_nmntvnodes, nvp) { 2969 if (vp->v_mount != mp) { 2970 if (--tries > 0) 2971 goto loop; 2972 break; 2973 } 2974 2975 VI_LOCK(vp); 2976 if (vp->v_iflag & VI_XLOCK) { 2977 VI_UNLOCK(vp); 2978 continue; 2979 } 2980 2981 if ((vp->v_iflag & VI_OBJDIRTY) && 2982 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 2983 MNT_IUNLOCK(mp); 2984 if (!vget(vp, 2985 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 2986 curthread)) { 2987 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 2988 vput(vp); 2989 MNT_ILOCK(mp); 2990 continue; 2991 } 2992 2993 if (VOP_GETVOBJECT(vp, &obj) == 0) { 2994 VM_OBJECT_LOCK(obj); 2995 vm_object_page_clean(obj, 0, 0, 2996 flags == MNT_WAIT ? 2997 OBJPC_SYNC : OBJPC_NOSYNC); 2998 VM_OBJECT_UNLOCK(obj); 2999 } 3000 vput(vp); 3001 } 3002 MNT_ILOCK(mp); 3003 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3004 if (--tries > 0) 3005 goto loop; 3006 break; 3007 } 3008 } else 3009 VI_UNLOCK(vp); 3010 } 3011 MNT_IUNLOCK(mp); 3012 } 3013 3014 /* 3015 * Create the VM object needed for VMIO and mmap support. This 3016 * is done for all VREG files in the system. Some filesystems might 3017 * afford the additional metadata buffering capability of the 3018 * VMIO code by making the device node be VMIO mode also. 3019 * 3020 * vp must be locked when vfs_object_create is called. 3021 */ 3022 int 3023 vfs_object_create(struct vnode *vp, struct thread *td, struct ucred *cred) 3024 { 3025 3026 GIANT_REQUIRED; 3027 return (VOP_CREATEVOBJECT(vp, cred, td)); 3028 } 3029 3030 /* 3031 * Mark a vnode as free, putting it up for recycling. 3032 */ 3033 void 3034 vfree(struct vnode *vp) 3035 { 3036 3037 ASSERT_VI_LOCKED(vp, "vfree"); 3038 mtx_lock(&vnode_free_list_mtx); 3039 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3040 if (vp->v_iflag & VI_AGE) { 3041 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3042 } else { 3043 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3044 } 3045 freevnodes++; 3046 mtx_unlock(&vnode_free_list_mtx); 3047 vp->v_iflag &= ~VI_AGE; 3048 vp->v_iflag |= VI_FREE; 3049 } 3050 3051 /* 3052 * Opposite of vfree() - mark a vnode as in use. 3053 */ 3054 void 3055 vbusy(struct vnode *vp) 3056 { 3057 3058 ASSERT_VI_LOCKED(vp, "vbusy"); 3059 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3060 3061 mtx_lock(&vnode_free_list_mtx); 3062 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3063 freevnodes--; 3064 mtx_unlock(&vnode_free_list_mtx); 3065 3066 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3067 } 3068 3069 /* 3070 * Initalize per-vnode helper structure to hold poll-related state. 3071 */ 3072 void 3073 v_addpollinfo(struct vnode *vp) 3074 { 3075 struct vpollinfo *vi; 3076 3077 vi = uma_zalloc(vnodepoll_zone, M_WAITOK); 3078 if (vp->v_pollinfo != NULL) { 3079 uma_zfree(vnodepoll_zone, vi); 3080 return; 3081 } 3082 vp->v_pollinfo = vi; 3083 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3084 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, 3085 &vp->v_pollinfo->vpi_lock); 3086 } 3087 3088 /* 3089 * Record a process's interest in events which might happen to 3090 * a vnode. Because poll uses the historic select-style interface 3091 * internally, this routine serves as both the ``check for any 3092 * pending events'' and the ``record my interest in future events'' 3093 * functions. (These are done together, while the lock is held, 3094 * to avoid race conditions.) 3095 */ 3096 int 3097 vn_pollrecord(vp, td, events) 3098 struct vnode *vp; 3099 struct thread *td; 3100 short events; 3101 { 3102 3103 if (vp->v_pollinfo == NULL) 3104 v_addpollinfo(vp); 3105 mtx_lock(&vp->v_pollinfo->vpi_lock); 3106 if (vp->v_pollinfo->vpi_revents & events) { 3107 /* 3108 * This leaves events we are not interested 3109 * in available for the other process which 3110 * which presumably had requested them 3111 * (otherwise they would never have been 3112 * recorded). 3113 */ 3114 events &= vp->v_pollinfo->vpi_revents; 3115 vp->v_pollinfo->vpi_revents &= ~events; 3116 3117 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3118 return events; 3119 } 3120 vp->v_pollinfo->vpi_events |= events; 3121 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3122 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3123 return 0; 3124 } 3125 3126 /* 3127 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3128 * it is possible for us to miss an event due to race conditions, but 3129 * that condition is expected to be rare, so for the moment it is the 3130 * preferred interface. 3131 */ 3132 void 3133 vn_pollevent(vp, events) 3134 struct vnode *vp; 3135 short events; 3136 { 3137 3138 if (vp->v_pollinfo == NULL) 3139 v_addpollinfo(vp); 3140 mtx_lock(&vp->v_pollinfo->vpi_lock); 3141 if (vp->v_pollinfo->vpi_events & events) { 3142 /* 3143 * We clear vpi_events so that we don't 3144 * call selwakeup() twice if two events are 3145 * posted before the polling process(es) is 3146 * awakened. This also ensures that we take at 3147 * most one selwakeup() if the polling process 3148 * is no longer interested. However, it does 3149 * mean that only one event can be noticed at 3150 * a time. (Perhaps we should only clear those 3151 * event bits which we note?) XXX 3152 */ 3153 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3154 vp->v_pollinfo->vpi_revents |= events; 3155 selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); 3156 } 3157 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3158 } 3159 3160 /* 3161 * Wake up anyone polling on vp because it is being revoked. 3162 * This depends on dead_poll() returning POLLHUP for correct 3163 * behavior. 3164 */ 3165 void 3166 vn_pollgone(vp) 3167 struct vnode *vp; 3168 { 3169 3170 mtx_lock(&vp->v_pollinfo->vpi_lock); 3171 VN_KNOTE_LOCKED(vp, NOTE_REVOKE); 3172 if (vp->v_pollinfo->vpi_events) { 3173 vp->v_pollinfo->vpi_events = 0; 3174 selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); 3175 } 3176 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3177 } 3178 3179 3180 3181 /* 3182 * Routine to create and manage a filesystem syncer vnode. 3183 */ 3184 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3185 static int sync_fsync(struct vop_fsync_args *); 3186 static int sync_inactive(struct vop_inactive_args *); 3187 static int sync_reclaim(struct vop_reclaim_args *); 3188 3189 static vop_t **sync_vnodeop_p; 3190 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3191 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3192 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3193 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3194 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3195 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3196 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3197 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3198 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3199 { NULL, NULL } 3200 }; 3201 static struct vnodeopv_desc sync_vnodeop_opv_desc = 3202 { &sync_vnodeop_p, sync_vnodeop_entries }; 3203 3204 VNODEOP_SET(sync_vnodeop_opv_desc); 3205 3206 /* 3207 * Create a new filesystem syncer vnode for the specified mount point. 3208 */ 3209 int 3210 vfs_allocate_syncvnode(mp) 3211 struct mount *mp; 3212 { 3213 struct vnode *vp; 3214 static long start, incr, next; 3215 int error; 3216 3217 /* Allocate a new vnode */ 3218 if ((error = getnewvnode("syncer", mp, sync_vnodeop_p, &vp)) != 0) { 3219 mp->mnt_syncer = NULL; 3220 return (error); 3221 } 3222 vp->v_type = VNON; 3223 /* 3224 * Place the vnode onto the syncer worklist. We attempt to 3225 * scatter them about on the list so that they will go off 3226 * at evenly distributed times even if all the filesystems 3227 * are mounted at once. 3228 */ 3229 next += incr; 3230 if (next == 0 || next > syncer_maxdelay) { 3231 start /= 2; 3232 incr /= 2; 3233 if (start == 0) { 3234 start = syncer_maxdelay / 2; 3235 incr = syncer_maxdelay; 3236 } 3237 next = start; 3238 } 3239 VI_LOCK(vp); 3240 vn_syncer_add_to_worklist(&vp->v_bufobj, 3241 syncdelay > 0 ? next % syncdelay : 0); 3242 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 3243 mtx_lock(&sync_mtx); 3244 sync_vnode_count++; 3245 mtx_unlock(&sync_mtx); 3246 VI_UNLOCK(vp); 3247 mp->mnt_syncer = vp; 3248 return (0); 3249 } 3250 3251 /* 3252 * Do a lazy sync of the filesystem. 3253 */ 3254 static int 3255 sync_fsync(ap) 3256 struct vop_fsync_args /* { 3257 struct vnode *a_vp; 3258 struct ucred *a_cred; 3259 int a_waitfor; 3260 struct thread *a_td; 3261 } */ *ap; 3262 { 3263 struct vnode *syncvp = ap->a_vp; 3264 struct mount *mp = syncvp->v_mount; 3265 struct thread *td = ap->a_td; 3266 int error, asyncflag; 3267 struct bufobj *bo; 3268 3269 /* 3270 * We only need to do something if this is a lazy evaluation. 3271 */ 3272 if (ap->a_waitfor != MNT_LAZY) 3273 return (0); 3274 3275 /* 3276 * Move ourselves to the back of the sync list. 3277 */ 3278 bo = &syncvp->v_bufobj; 3279 BO_LOCK(bo); 3280 vn_syncer_add_to_worklist(bo, syncdelay); 3281 BO_UNLOCK(bo); 3282 3283 /* 3284 * Walk the list of vnodes pushing all that are dirty and 3285 * not already on the sync list. 3286 */ 3287 mtx_lock(&mountlist_mtx); 3288 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3289 mtx_unlock(&mountlist_mtx); 3290 return (0); 3291 } 3292 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3293 vfs_unbusy(mp, td); 3294 return (0); 3295 } 3296 asyncflag = mp->mnt_flag & MNT_ASYNC; 3297 mp->mnt_flag &= ~MNT_ASYNC; 3298 vfs_msync(mp, MNT_NOWAIT); 3299 error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3300 if (asyncflag) 3301 mp->mnt_flag |= MNT_ASYNC; 3302 vn_finished_write(mp); 3303 vfs_unbusy(mp, td); 3304 return (error); 3305 } 3306 3307 /* 3308 * The syncer vnode is no referenced. 3309 */ 3310 static int 3311 sync_inactive(ap) 3312 struct vop_inactive_args /* { 3313 struct vnode *a_vp; 3314 struct thread *a_td; 3315 } */ *ap; 3316 { 3317 3318 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3319 vgone(ap->a_vp); 3320 return (0); 3321 } 3322 3323 /* 3324 * The syncer vnode is no longer needed and is being decommissioned. 3325 * 3326 * Modifications to the worklist must be protected by sync_mtx. 3327 */ 3328 static int 3329 sync_reclaim(ap) 3330 struct vop_reclaim_args /* { 3331 struct vnode *a_vp; 3332 } */ *ap; 3333 { 3334 struct vnode *vp = ap->a_vp; 3335 struct bufobj *bo; 3336 3337 VI_LOCK(vp); 3338 bo = &vp->v_bufobj; 3339 vp->v_mount->mnt_syncer = NULL; 3340 if (bo->bo_flag & BO_ONWORKLST) { 3341 mtx_lock(&sync_mtx); 3342 LIST_REMOVE(bo, bo_synclist); 3343 syncer_worklist_len--; 3344 sync_vnode_count--; 3345 mtx_unlock(&sync_mtx); 3346 bo->bo_flag &= ~BO_ONWORKLST; 3347 } 3348 VI_UNLOCK(vp); 3349 3350 return (0); 3351 } 3352 3353 /* 3354 * Check if vnode represents a disk device 3355 */ 3356 int 3357 vn_isdisk(vp, errp) 3358 struct vnode *vp; 3359 int *errp; 3360 { 3361 int error; 3362 3363 error = 0; 3364 dev_lock(); 3365 if (vp->v_type != VCHR) 3366 error = ENOTBLK; 3367 else if (vp->v_rdev == NULL) 3368 error = ENXIO; 3369 else if (vp->v_rdev->si_devsw == NULL) 3370 error = ENXIO; 3371 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 3372 error = ENOTBLK; 3373 dev_unlock(); 3374 if (errp != NULL) 3375 *errp = error; 3376 return (error == 0); 3377 } 3378 3379 /* 3380 * Free data allocated by namei(); see namei(9) for details. 3381 */ 3382 void 3383 NDFREE(ndp, flags) 3384 struct nameidata *ndp; 3385 const u_int flags; 3386 { 3387 3388 if (!(flags & NDF_NO_FREE_PNBUF) && 3389 (ndp->ni_cnd.cn_flags & HASBUF)) { 3390 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3391 ndp->ni_cnd.cn_flags &= ~HASBUF; 3392 } 3393 if (!(flags & NDF_NO_DVP_UNLOCK) && 3394 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3395 ndp->ni_dvp != ndp->ni_vp) 3396 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3397 if (!(flags & NDF_NO_DVP_RELE) && 3398 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3399 vrele(ndp->ni_dvp); 3400 ndp->ni_dvp = NULL; 3401 } 3402 if (!(flags & NDF_NO_VP_UNLOCK) && 3403 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3404 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3405 if (!(flags & NDF_NO_VP_RELE) && 3406 ndp->ni_vp) { 3407 vrele(ndp->ni_vp); 3408 ndp->ni_vp = NULL; 3409 } 3410 if (!(flags & NDF_NO_STARTDIR_RELE) && 3411 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3412 vrele(ndp->ni_startdir); 3413 ndp->ni_startdir = NULL; 3414 } 3415 } 3416 3417 /* 3418 * Common filesystem object access control check routine. Accepts a 3419 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3420 * and optional call-by-reference privused argument allowing vaccess() 3421 * to indicate to the caller whether privilege was used to satisfy the 3422 * request (obsoleted). Returns 0 on success, or an errno on failure. 3423 */ 3424 int 3425 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3426 enum vtype type; 3427 mode_t file_mode; 3428 uid_t file_uid; 3429 gid_t file_gid; 3430 mode_t acc_mode; 3431 struct ucred *cred; 3432 int *privused; 3433 { 3434 mode_t dac_granted; 3435 #ifdef CAPABILITIES 3436 mode_t cap_granted; 3437 #endif 3438 3439 /* 3440 * Look for a normal, non-privileged way to access the file/directory 3441 * as requested. If it exists, go with that. 3442 */ 3443 3444 if (privused != NULL) 3445 *privused = 0; 3446 3447 dac_granted = 0; 3448 3449 /* Check the owner. */ 3450 if (cred->cr_uid == file_uid) { 3451 dac_granted |= VADMIN; 3452 if (file_mode & S_IXUSR) 3453 dac_granted |= VEXEC; 3454 if (file_mode & S_IRUSR) 3455 dac_granted |= VREAD; 3456 if (file_mode & S_IWUSR) 3457 dac_granted |= (VWRITE | VAPPEND); 3458 3459 if ((acc_mode & dac_granted) == acc_mode) 3460 return (0); 3461 3462 goto privcheck; 3463 } 3464 3465 /* Otherwise, check the groups (first match) */ 3466 if (groupmember(file_gid, cred)) { 3467 if (file_mode & S_IXGRP) 3468 dac_granted |= VEXEC; 3469 if (file_mode & S_IRGRP) 3470 dac_granted |= VREAD; 3471 if (file_mode & S_IWGRP) 3472 dac_granted |= (VWRITE | VAPPEND); 3473 3474 if ((acc_mode & dac_granted) == acc_mode) 3475 return (0); 3476 3477 goto privcheck; 3478 } 3479 3480 /* Otherwise, check everyone else. */ 3481 if (file_mode & S_IXOTH) 3482 dac_granted |= VEXEC; 3483 if (file_mode & S_IROTH) 3484 dac_granted |= VREAD; 3485 if (file_mode & S_IWOTH) 3486 dac_granted |= (VWRITE | VAPPEND); 3487 if ((acc_mode & dac_granted) == acc_mode) 3488 return (0); 3489 3490 privcheck: 3491 if (!suser_cred(cred, SUSER_ALLOWJAIL)) { 3492 /* XXX audit: privilege used */ 3493 if (privused != NULL) 3494 *privused = 1; 3495 return (0); 3496 } 3497 3498 #ifdef CAPABILITIES 3499 /* 3500 * Build a capability mask to determine if the set of capabilities 3501 * satisfies the requirements when combined with the granted mask 3502 * from above. 3503 * For each capability, if the capability is required, bitwise 3504 * or the request type onto the cap_granted mask. 3505 */ 3506 cap_granted = 0; 3507 3508 if (type == VDIR) { 3509 /* 3510 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3511 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3512 */ 3513 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3514 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) 3515 cap_granted |= VEXEC; 3516 } else { 3517 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3518 !cap_check(cred, NULL, CAP_DAC_EXECUTE, SUSER_ALLOWJAIL)) 3519 cap_granted |= VEXEC; 3520 } 3521 3522 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3523 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) 3524 cap_granted |= VREAD; 3525 3526 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3527 !cap_check(cred, NULL, CAP_DAC_WRITE, SUSER_ALLOWJAIL)) 3528 cap_granted |= (VWRITE | VAPPEND); 3529 3530 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3531 !cap_check(cred, NULL, CAP_FOWNER, SUSER_ALLOWJAIL)) 3532 cap_granted |= VADMIN; 3533 3534 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3535 /* XXX audit: privilege used */ 3536 if (privused != NULL) 3537 *privused = 1; 3538 return (0); 3539 } 3540 #endif 3541 3542 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3543 } 3544 3545 /* 3546 * Credential check based on process requesting service, and per-attribute 3547 * permissions. 3548 */ 3549 int 3550 extattr_check_cred(struct vnode *vp, int attrnamespace, 3551 struct ucred *cred, struct thread *td, int access) 3552 { 3553 3554 /* 3555 * Kernel-invoked always succeeds. 3556 */ 3557 if (cred == NOCRED) 3558 return (0); 3559 3560 /* 3561 * Do not allow privileged processes in jail to directly 3562 * manipulate system attributes. 3563 * 3564 * XXX What capability should apply here? 3565 * Probably CAP_SYS_SETFFLAG. 3566 */ 3567 switch (attrnamespace) { 3568 case EXTATTR_NAMESPACE_SYSTEM: 3569 /* Potentially should be: return (EPERM); */ 3570 return (suser_cred(cred, 0)); 3571 case EXTATTR_NAMESPACE_USER: 3572 return (VOP_ACCESS(vp, access, cred, td)); 3573 default: 3574 return (EPERM); 3575 } 3576 } 3577 3578 #ifdef DEBUG_VFS_LOCKS 3579 /* 3580 * This only exists to supress warnings from unlocked specfs accesses. It is 3581 * no longer ok to have an unlocked VFS. 3582 */ 3583 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 3584 3585 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3586 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, ""); 3587 3588 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3589 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, ""); 3590 3591 int vfs_badlock_print = 1; /* Print lock violations. */ 3592 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, ""); 3593 3594 #ifdef KDB 3595 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 3596 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, ""); 3597 #endif 3598 3599 static void 3600 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3601 { 3602 3603 #ifdef KDB 3604 if (vfs_badlock_backtrace) 3605 kdb_backtrace(); 3606 #endif 3607 if (vfs_badlock_print) 3608 printf("%s: %p %s\n", str, (void *)vp, msg); 3609 if (vfs_badlock_ddb) 3610 kdb_enter("lock violation"); 3611 } 3612 3613 void 3614 assert_vi_locked(struct vnode *vp, const char *str) 3615 { 3616 3617 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3618 vfs_badlock("interlock is not locked but should be", str, vp); 3619 } 3620 3621 void 3622 assert_vi_unlocked(struct vnode *vp, const char *str) 3623 { 3624 3625 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3626 vfs_badlock("interlock is locked but should not be", str, vp); 3627 } 3628 3629 void 3630 assert_vop_locked(struct vnode *vp, const char *str) 3631 { 3632 3633 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0) 3634 vfs_badlock("is not locked but should be", str, vp); 3635 } 3636 3637 void 3638 assert_vop_unlocked(struct vnode *vp, const char *str) 3639 { 3640 3641 if (vp && !IGNORE_LOCK(vp) && 3642 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 3643 vfs_badlock("is locked but should not be", str, vp); 3644 } 3645 3646 #if 0 3647 void 3648 assert_vop_elocked(struct vnode *vp, const char *str) 3649 { 3650 3651 if (vp && !IGNORE_LOCK(vp) && 3652 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 3653 vfs_badlock("is not exclusive locked but should be", str, vp); 3654 } 3655 3656 void 3657 assert_vop_elocked_other(struct vnode *vp, const char *str) 3658 { 3659 3660 if (vp && !IGNORE_LOCK(vp) && 3661 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 3662 vfs_badlock("is not exclusive locked by another thread", 3663 str, vp); 3664 } 3665 3666 void 3667 assert_vop_slocked(struct vnode *vp, const char *str) 3668 { 3669 3670 if (vp && !IGNORE_LOCK(vp) && 3671 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 3672 vfs_badlock("is not locked shared but should be", str, vp); 3673 } 3674 #endif /* 0 */ 3675 3676 void 3677 vop_rename_pre(void *ap) 3678 { 3679 struct vop_rename_args *a = ap; 3680 3681 if (a->a_tvp) 3682 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3683 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3684 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3685 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3686 3687 /* Check the source (from). */ 3688 if (a->a_tdvp != a->a_fdvp) 3689 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3690 if (a->a_tvp != a->a_fvp) 3691 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked"); 3692 3693 /* Check the target. */ 3694 if (a->a_tvp) 3695 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3696 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3697 } 3698 3699 void 3700 vop_strategy_pre(void *ap) 3701 { 3702 struct vop_strategy_args *a; 3703 struct buf *bp; 3704 3705 a = ap; 3706 bp = a->a_bp; 3707 3708 /* 3709 * Cluster ops lock their component buffers but not the IO container. 3710 */ 3711 if ((bp->b_flags & B_CLUSTER) != 0) 3712 return; 3713 3714 if (BUF_REFCNT(bp) < 1) { 3715 if (vfs_badlock_print) 3716 printf( 3717 "VOP_STRATEGY: bp is not locked but should be\n"); 3718 if (vfs_badlock_ddb) 3719 kdb_enter("lock violation"); 3720 } 3721 } 3722 3723 void 3724 vop_lookup_pre(void *ap) 3725 { 3726 struct vop_lookup_args *a; 3727 struct vnode *dvp; 3728 3729 a = ap; 3730 dvp = a->a_dvp; 3731 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3732 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3733 } 3734 3735 void 3736 vop_lookup_post(void *ap, int rc) 3737 { 3738 struct vop_lookup_args *a; 3739 struct componentname *cnp; 3740 struct vnode *dvp; 3741 struct vnode *vp; 3742 int flags; 3743 3744 a = ap; 3745 dvp = a->a_dvp; 3746 cnp = a->a_cnp; 3747 vp = *(a->a_vpp); 3748 flags = cnp->cn_flags; 3749 3750 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3751 3752 /* 3753 * If this is the last path component for this lookup and LOCKPARENT 3754 * is set, OR if there is an error the directory has to be locked. 3755 */ 3756 if ((flags & LOCKPARENT) && (flags & ISLASTCN)) 3757 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); 3758 else if (rc != 0) 3759 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); 3760 else if (dvp != vp) 3761 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); 3762 if (flags & PDIRUNLOCK) 3763 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); 3764 } 3765 3766 void 3767 vop_lock_pre(void *ap) 3768 { 3769 struct vop_lock_args *a = ap; 3770 3771 if ((a->a_flags & LK_INTERLOCK) == 0) 3772 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3773 else 3774 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3775 } 3776 3777 void 3778 vop_lock_post(void *ap, int rc) 3779 { 3780 struct vop_lock_args *a = ap; 3781 3782 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3783 if (rc == 0) 3784 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3785 } 3786 3787 void 3788 vop_unlock_pre(void *ap) 3789 { 3790 struct vop_unlock_args *a = ap; 3791 3792 if (a->a_flags & LK_INTERLOCK) 3793 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 3794 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 3795 } 3796 3797 void 3798 vop_unlock_post(void *ap, int rc) 3799 { 3800 struct vop_unlock_args *a = ap; 3801 3802 if (a->a_flags & LK_INTERLOCK) 3803 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 3804 } 3805 #endif /* DEBUG_VFS_LOCKS */ 3806 3807 static struct knlist fs_knlist; 3808 3809 static void 3810 vfs_event_init(void *arg) 3811 { 3812 knlist_init(&fs_knlist, NULL); 3813 } 3814 /* XXX - correct order? */ 3815 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 3816 3817 void 3818 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused) 3819 { 3820 3821 KNOTE_UNLOCKED(&fs_knlist, event); 3822 } 3823 3824 static int filt_fsattach(struct knote *kn); 3825 static void filt_fsdetach(struct knote *kn); 3826 static int filt_fsevent(struct knote *kn, long hint); 3827 3828 struct filterops fs_filtops = 3829 { 0, filt_fsattach, filt_fsdetach, filt_fsevent }; 3830 3831 static int 3832 filt_fsattach(struct knote *kn) 3833 { 3834 3835 kn->kn_flags |= EV_CLEAR; 3836 knlist_add(&fs_knlist, kn, 0); 3837 return (0); 3838 } 3839 3840 static void 3841 filt_fsdetach(struct knote *kn) 3842 { 3843 3844 knlist_remove(&fs_knlist, kn, 0); 3845 } 3846 3847 static int 3848 filt_fsevent(struct knote *kn, long hint) 3849 { 3850 3851 kn->kn_fflags |= hint; 3852 return (kn->kn_fflags != 0); 3853 } 3854 3855 static int 3856 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 3857 { 3858 struct vfsidctl vc; 3859 int error; 3860 struct mount *mp; 3861 3862 error = SYSCTL_IN(req, &vc, sizeof(vc)); 3863 if (error) 3864 return (error); 3865 if (vc.vc_vers != VFS_CTL_VERS1) 3866 return (EINVAL); 3867 mp = vfs_getvfs(&vc.vc_fsid); 3868 if (mp == NULL) 3869 return (ENOENT); 3870 /* ensure that a specific sysctl goes to the right filesystem. */ 3871 if (strcmp(vc.vc_fstypename, "*") != 0 && 3872 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 3873 return (EINVAL); 3874 } 3875 VCTLTOREQ(&vc, req); 3876 return (VFS_SYSCTL(mp, vc.vc_op, req)); 3877 } 3878 3879 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, 3880 NULL, 0, sysctl_vfs_ctl, "", "Sysctl by fsid"); 3881 3882 /* 3883 * Function to initialize a va_filerev field sensibly. 3884 * XXX: Wouldn't a random number make a lot more sense ?? 3885 */ 3886 u_quad_t 3887 init_va_filerev(void) 3888 { 3889 struct bintime bt; 3890 3891 getbinuptime(&bt); 3892 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 3893 } 3894