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/eventhandler.h> 53 #include <sys/extattr.h> 54 #include <sys/fcntl.h> 55 #include <sys/kernel.h> 56 #include <sys/kthread.h> 57 #include <sys/mac.h> 58 #include <sys/malloc.h> 59 #include <sys/mount.h> 60 #include <sys/namei.h> 61 #include <sys/sleepqueue.h> 62 #include <sys/stat.h> 63 #include <sys/sysctl.h> 64 #include <sys/syslog.h> 65 #include <sys/vmmeter.h> 66 #include <sys/vnode.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_object.h> 70 #include <vm/vm_extern.h> 71 #include <vm/pmap.h> 72 #include <vm/vm_map.h> 73 #include <vm/vm_page.h> 74 #include <vm/vm_kern.h> 75 #include <vm/uma.h> 76 77 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 78 79 static void addalias(struct vnode *vp, dev_t nvp_rdev); 80 static void insmntque(struct vnode *vp, struct mount *mp); 81 static void vclean(struct vnode *vp, int flags, struct thread *td); 82 static void vlruvp(struct vnode *vp); 83 static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, 84 int slpflag, int slptimeo, int *errorp); 85 static int vtryrecycle(struct vnode *vp); 86 static void vx_lock(struct vnode *vp); 87 static void vx_unlock(struct vnode *vp); 88 static void vgonechrl(struct vnode *vp, struct thread *td); 89 90 91 /* 92 * Number of vnodes in existence. Increased whenever getnewvnode() 93 * allocates a new vnode, never decreased. 94 */ 95 static unsigned long numvnodes; 96 97 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 98 99 /* 100 * Conversion tables for conversion from vnode types to inode formats 101 * and back. 102 */ 103 enum vtype iftovt_tab[16] = { 104 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 105 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 106 }; 107 int vttoif_tab[9] = { 108 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 109 S_IFSOCK, S_IFIFO, S_IFMT, 110 }; 111 112 /* 113 * List of vnodes that are ready for recycling. 114 */ 115 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 116 117 /* 118 * Minimum number of free vnodes. If there are fewer than this free vnodes, 119 * getnewvnode() will return a newly allocated vnode. 120 */ 121 static u_long wantfreevnodes = 25; 122 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 123 /* Number of vnodes in the free list. */ 124 static u_long freevnodes; 125 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 126 127 /* 128 * Various variables used for debugging the new implementation of 129 * reassignbuf(). 130 * XXX these are probably of (very) limited utility now. 131 */ 132 static int reassignbufcalls; 133 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 134 static int nameileafonly; 135 SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 136 137 /* 138 * Cache for the mount type id assigned to NFS. This is used for 139 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 140 */ 141 int nfs_mount_type = -1; 142 143 /* To keep more than one thread at a time from running vfs_getnewfsid */ 144 static struct mtx mntid_mtx; 145 146 /* 147 * Lock for any access to the following: 148 * vnode_free_list 149 * numvnodes 150 * freevnodes 151 */ 152 static struct mtx vnode_free_list_mtx; 153 154 /* 155 * For any iteration/modification of dev->si_hlist (linked through 156 * v_specnext) 157 */ 158 static struct mtx spechash_mtx; 159 160 /* Publicly exported FS */ 161 struct nfs_public nfs_pub; 162 163 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 164 static uma_zone_t vnode_zone; 165 static uma_zone_t vnodepoll_zone; 166 167 /* Set to 1 to print out reclaim of active vnodes */ 168 int prtactive; 169 170 /* 171 * The workitem queue. 172 * 173 * It is useful to delay writes of file data and filesystem metadata 174 * for tens of seconds so that quickly created and deleted files need 175 * not waste disk bandwidth being created and removed. To realize this, 176 * we append vnodes to a "workitem" queue. When running with a soft 177 * updates implementation, most pending metadata dependencies should 178 * not wait for more than a few seconds. Thus, mounted on block devices 179 * are delayed only about a half the time that file data is delayed. 180 * Similarly, directory updates are more critical, so are only delayed 181 * about a third the time that file data is delayed. Thus, there are 182 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 183 * one each second (driven off the filesystem syncer process). The 184 * syncer_delayno variable indicates the next queue that is to be processed. 185 * Items that need to be processed soon are placed in this queue: 186 * 187 * syncer_workitem_pending[syncer_delayno] 188 * 189 * A delay of fifteen seconds is done by placing the request fifteen 190 * entries later in the queue: 191 * 192 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 193 * 194 */ 195 static int syncer_delayno; 196 static long syncer_mask; 197 LIST_HEAD(synclist, vnode); 198 static struct synclist *syncer_workitem_pending; 199 /* 200 * The sync_mtx protects: 201 * vp->v_synclist 202 * syncer_delayno 203 * syncer_workitem_pending 204 * rushjob 205 */ 206 static struct mtx sync_mtx; 207 208 #define SYNCER_MAXDELAY 32 209 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 210 static int syncdelay = 30; /* max time to delay syncing data */ 211 static int filedelay = 30; /* time to delay syncing files */ 212 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 213 static int dirdelay = 29; /* time to delay syncing directories */ 214 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 215 static int metadelay = 28; /* time to delay syncing metadata */ 216 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 217 static int rushjob; /* number of slots to run ASAP */ 218 static int stat_rush_requests; /* number of times I/O speeded up */ 219 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 220 221 /* 222 * Number of vnodes we want to exist at any one time. This is mostly used 223 * to size hash tables in vnode-related code. It is normally not used in 224 * getnewvnode(), as wantfreevnodes is normally nonzero.) 225 * 226 * XXX desiredvnodes is historical cruft and should not exist. 227 */ 228 int desiredvnodes; 229 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 230 &desiredvnodes, 0, "Maximum number of vnodes"); 231 static int minvnodes; 232 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 233 &minvnodes, 0, "Minimum number of vnodes"); 234 static int vnlru_nowhere; 235 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 236 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 237 238 /* Hook for calling soft updates. */ 239 int (*softdep_process_worklist_hook)(struct mount *); 240 241 /* 242 * Initialize the vnode management data structures. 243 */ 244 static void 245 vntblinit(void *dummy __unused) 246 { 247 248 /* 249 * Desiredvnodes is a function of the physical memory size and 250 * the kernel's heap size. Specifically, desiredvnodes scales 251 * in proportion to the physical memory size until two fifths 252 * of the kernel's heap size is consumed by vnodes and vm 253 * objects. 254 */ 255 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / 256 (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); 257 minvnodes = desiredvnodes / 4; 258 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 259 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 260 mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); 261 TAILQ_INIT(&vnode_free_list); 262 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 263 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 264 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 265 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 266 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 267 /* 268 * Initialize the filesystem syncer. 269 */ 270 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 271 &syncer_mask); 272 syncer_maxdelay = syncer_mask + 1; 273 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 274 } 275 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 276 277 278 /* 279 * Mark a mount point as busy. Used to synchronize access and to delay 280 * unmounting. Interlock is not released on failure. 281 */ 282 int 283 vfs_busy(mp, flags, interlkp, td) 284 struct mount *mp; 285 int flags; 286 struct mtx *interlkp; 287 struct thread *td; 288 { 289 int lkflags; 290 291 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 292 if (flags & LK_NOWAIT) 293 return (ENOENT); 294 mp->mnt_kern_flag |= MNTK_MWAIT; 295 /* 296 * Since all busy locks are shared except the exclusive 297 * lock granted when unmounting, the only place that a 298 * wakeup needs to be done is at the release of the 299 * exclusive lock at the end of dounmount. 300 */ 301 msleep(mp, interlkp, PVFS, "vfs_busy", 0); 302 return (ENOENT); 303 } 304 lkflags = LK_SHARED | LK_NOPAUSE; 305 if (interlkp) 306 lkflags |= LK_INTERLOCK; 307 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 308 panic("vfs_busy: unexpected lock failure"); 309 return (0); 310 } 311 312 /* 313 * Free a busy filesystem. 314 */ 315 void 316 vfs_unbusy(mp, td) 317 struct mount *mp; 318 struct thread *td; 319 { 320 321 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 322 } 323 324 /* 325 * Lookup a mount point by filesystem identifier. 326 */ 327 struct mount * 328 vfs_getvfs(fsid) 329 fsid_t *fsid; 330 { 331 register struct mount *mp; 332 333 mtx_lock(&mountlist_mtx); 334 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 335 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 336 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 337 mtx_unlock(&mountlist_mtx); 338 return (mp); 339 } 340 } 341 mtx_unlock(&mountlist_mtx); 342 return ((struct mount *) 0); 343 } 344 345 /* 346 * Get a new unique fsid. Try to make its val[0] unique, since this value 347 * will be used to create fake device numbers for stat(). Also try (but 348 * not so hard) make its val[0] unique mod 2^16, since some emulators only 349 * support 16-bit device numbers. We end up with unique val[0]'s for the 350 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 351 * 352 * Keep in mind that several mounts may be running in parallel. Starting 353 * the search one past where the previous search terminated is both a 354 * micro-optimization and a defense against returning the same fsid to 355 * different mounts. 356 */ 357 void 358 vfs_getnewfsid(mp) 359 struct mount *mp; 360 { 361 static u_int16_t mntid_base; 362 fsid_t tfsid; 363 int mtype; 364 365 mtx_lock(&mntid_mtx); 366 mtype = mp->mnt_vfc->vfc_typenum; 367 tfsid.val[1] = mtype; 368 mtype = (mtype & 0xFF) << 24; 369 for (;;) { 370 tfsid.val[0] = makeudev(255, 371 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 372 mntid_base++; 373 if (vfs_getvfs(&tfsid) == NULL) 374 break; 375 } 376 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 377 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 378 mtx_unlock(&mntid_mtx); 379 } 380 381 /* 382 * Knob to control the precision of file timestamps: 383 * 384 * 0 = seconds only; nanoseconds zeroed. 385 * 1 = seconds and nanoseconds, accurate within 1/HZ. 386 * 2 = seconds and nanoseconds, truncated to microseconds. 387 * >=3 = seconds and nanoseconds, maximum precision. 388 */ 389 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 390 391 static int timestamp_precision = TSP_SEC; 392 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 393 ×tamp_precision, 0, ""); 394 395 /* 396 * Get a current timestamp. 397 */ 398 void 399 vfs_timestamp(tsp) 400 struct timespec *tsp; 401 { 402 struct timeval tv; 403 404 switch (timestamp_precision) { 405 case TSP_SEC: 406 tsp->tv_sec = time_second; 407 tsp->tv_nsec = 0; 408 break; 409 case TSP_HZ: 410 getnanotime(tsp); 411 break; 412 case TSP_USEC: 413 microtime(&tv); 414 TIMEVAL_TO_TIMESPEC(&tv, tsp); 415 break; 416 case TSP_NSEC: 417 default: 418 nanotime(tsp); 419 break; 420 } 421 } 422 423 /* 424 * Set vnode attributes to VNOVAL 425 */ 426 void 427 vattr_null(vap) 428 register struct vattr *vap; 429 { 430 431 vap->va_type = VNON; 432 vap->va_size = VNOVAL; 433 vap->va_bytes = VNOVAL; 434 vap->va_mode = VNOVAL; 435 vap->va_nlink = VNOVAL; 436 vap->va_uid = VNOVAL; 437 vap->va_gid = VNOVAL; 438 vap->va_fsid = VNOVAL; 439 vap->va_fileid = VNOVAL; 440 vap->va_blocksize = VNOVAL; 441 vap->va_rdev = VNOVAL; 442 vap->va_atime.tv_sec = VNOVAL; 443 vap->va_atime.tv_nsec = VNOVAL; 444 vap->va_mtime.tv_sec = VNOVAL; 445 vap->va_mtime.tv_nsec = VNOVAL; 446 vap->va_ctime.tv_sec = VNOVAL; 447 vap->va_ctime.tv_nsec = VNOVAL; 448 vap->va_birthtime.tv_sec = VNOVAL; 449 vap->va_birthtime.tv_nsec = VNOVAL; 450 vap->va_flags = VNOVAL; 451 vap->va_gen = VNOVAL; 452 vap->va_vaflags = 0; 453 } 454 455 /* 456 * This routine is called when we have too many vnodes. It attempts 457 * to free <count> vnodes and will potentially free vnodes that still 458 * have VM backing store (VM backing store is typically the cause 459 * of a vnode blowout so we want to do this). Therefore, this operation 460 * is not considered cheap. 461 * 462 * A number of conditions may prevent a vnode from being reclaimed. 463 * the buffer cache may have references on the vnode, a directory 464 * vnode may still have references due to the namei cache representing 465 * underlying files, or the vnode may be in active use. It is not 466 * desireable to reuse such vnodes. These conditions may cause the 467 * number of vnodes to reach some minimum value regardless of what 468 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 469 */ 470 static int 471 vlrureclaim(struct mount *mp) 472 { 473 struct vnode *vp; 474 int done; 475 int trigger; 476 int usevnodes; 477 int count; 478 479 /* 480 * Calculate the trigger point, don't allow user 481 * screwups to blow us up. This prevents us from 482 * recycling vnodes with lots of resident pages. We 483 * aren't trying to free memory, we are trying to 484 * free vnodes. 485 */ 486 usevnodes = desiredvnodes; 487 if (usevnodes <= 0) 488 usevnodes = 1; 489 trigger = cnt.v_page_count * 2 / usevnodes; 490 491 done = 0; 492 MNT_ILOCK(mp); 493 count = mp->mnt_nvnodelistsize / 10 + 1; 494 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 495 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 496 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 497 498 if (vp->v_type != VNON && 499 vp->v_type != VBAD && 500 VI_TRYLOCK(vp)) { 501 if (VMIGHTFREE(vp) && /* critical path opt */ 502 (vp->v_object == NULL || 503 vp->v_object->resident_page_count < trigger)) { 504 MNT_IUNLOCK(mp); 505 vgonel(vp, curthread); 506 done++; 507 MNT_ILOCK(mp); 508 } else 509 VI_UNLOCK(vp); 510 } 511 --count; 512 } 513 MNT_IUNLOCK(mp); 514 return done; 515 } 516 517 /* 518 * Attempt to recycle vnodes in a context that is always safe to block. 519 * Calling vlrurecycle() from the bowels of filesystem code has some 520 * interesting deadlock problems. 521 */ 522 static struct proc *vnlruproc; 523 static int vnlruproc_sig; 524 525 static void 526 vnlru_proc(void) 527 { 528 struct mount *mp, *nmp; 529 int done; 530 struct proc *p = vnlruproc; 531 struct thread *td = FIRST_THREAD_IN_PROC(p); 532 533 mtx_lock(&Giant); 534 535 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 536 SHUTDOWN_PRI_FIRST); 537 538 for (;;) { 539 kthread_suspend_check(p); 540 mtx_lock(&vnode_free_list_mtx); 541 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 542 mtx_unlock(&vnode_free_list_mtx); 543 vnlruproc_sig = 0; 544 wakeup(&vnlruproc_sig); 545 tsleep(vnlruproc, PVFS, "vlruwt", hz); 546 continue; 547 } 548 mtx_unlock(&vnode_free_list_mtx); 549 done = 0; 550 mtx_lock(&mountlist_mtx); 551 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 552 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 553 nmp = TAILQ_NEXT(mp, mnt_list); 554 continue; 555 } 556 done += vlrureclaim(mp); 557 mtx_lock(&mountlist_mtx); 558 nmp = TAILQ_NEXT(mp, mnt_list); 559 vfs_unbusy(mp, td); 560 } 561 mtx_unlock(&mountlist_mtx); 562 if (done == 0) { 563 #if 0 564 /* These messages are temporary debugging aids */ 565 if (vnlru_nowhere < 5) 566 printf("vnlru process getting nowhere..\n"); 567 else if (vnlru_nowhere == 5) 568 printf("vnlru process messages stopped.\n"); 569 #endif 570 vnlru_nowhere++; 571 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 572 } 573 } 574 } 575 576 static struct kproc_desc vnlru_kp = { 577 "vnlru", 578 vnlru_proc, 579 &vnlruproc 580 }; 581 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 582 583 584 /* 585 * Routines having to do with the management of the vnode table. 586 */ 587 588 /* 589 * Check to see if a free vnode can be recycled. If it can, 590 * recycle it and return it with the vnode interlock held. 591 */ 592 static int 593 vtryrecycle(struct vnode *vp) 594 { 595 struct thread *td = curthread; 596 vm_object_t object; 597 struct mount *vnmp; 598 int error; 599 600 /* Don't recycle if we can't get the interlock */ 601 if (!VI_TRYLOCK(vp)) 602 return (EWOULDBLOCK); 603 /* 604 * This vnode may found and locked via some other list, if so we 605 * can't recycle it yet. 606 */ 607 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 608 return (EWOULDBLOCK); 609 /* 610 * Don't recycle if its filesystem is being suspended. 611 */ 612 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 613 VOP_UNLOCK(vp, 0, td); 614 return (EBUSY); 615 } 616 617 /* 618 * Don't recycle if we still have cached pages. 619 */ 620 if (VOP_GETVOBJECT(vp, &object) == 0) { 621 VM_OBJECT_LOCK(object); 622 if (object->resident_page_count || 623 object->ref_count) { 624 VM_OBJECT_UNLOCK(object); 625 error = EBUSY; 626 goto done; 627 } 628 VM_OBJECT_UNLOCK(object); 629 } 630 if (LIST_FIRST(&vp->v_cache_src)) { 631 /* 632 * note: nameileafonly sysctl is temporary, 633 * for debugging only, and will eventually be 634 * removed. 635 */ 636 if (nameileafonly > 0) { 637 /* 638 * Do not reuse namei-cached directory 639 * vnodes that have cached 640 * subdirectories. 641 */ 642 if (cache_leaf_test(vp) < 0) { 643 error = EISDIR; 644 goto done; 645 } 646 } else if (nameileafonly < 0 || 647 vmiodirenable == 0) { 648 /* 649 * Do not reuse namei-cached directory 650 * vnodes if nameileafonly is -1 or 651 * if VMIO backing for directories is 652 * turned off (otherwise we reuse them 653 * too quickly). 654 */ 655 error = EBUSY; 656 goto done; 657 } 658 } 659 /* 660 * If we got this far, we need to acquire the interlock and see if 661 * anyone picked up this vnode from another list. If not, we will 662 * mark it with XLOCK via vgonel() so that anyone who does find it 663 * will skip over it. 664 */ 665 VI_LOCK(vp); 666 if (VSHOULDBUSY(vp) && (vp->v_iflag & VI_XLOCK) == 0) { 667 VI_UNLOCK(vp); 668 error = EBUSY; 669 goto done; 670 } 671 mtx_lock(&vnode_free_list_mtx); 672 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 673 vp->v_iflag &= ~VI_FREE; 674 mtx_unlock(&vnode_free_list_mtx); 675 vp->v_iflag |= VI_DOOMED; 676 if (vp->v_type != VBAD) { 677 VOP_UNLOCK(vp, 0, td); 678 vgonel(vp, td); 679 VI_LOCK(vp); 680 } else 681 VOP_UNLOCK(vp, 0, td); 682 vn_finished_write(vnmp); 683 return (0); 684 done: 685 VOP_UNLOCK(vp, 0, td); 686 vn_finished_write(vnmp); 687 return (error); 688 } 689 690 /* 691 * Return the next vnode from the free list. 692 */ 693 int 694 getnewvnode(tag, mp, vops, vpp) 695 const char *tag; 696 struct mount *mp; 697 vop_t **vops; 698 struct vnode **vpp; 699 { 700 struct vnode *vp = NULL; 701 struct vpollinfo *pollinfo = NULL; 702 703 mtx_lock(&vnode_free_list_mtx); 704 705 /* 706 * Try to reuse vnodes if we hit the max. This situation only 707 * occurs in certain large-memory (2G+) situations. We cannot 708 * attempt to directly reclaim vnodes due to nasty recursion 709 * problems. 710 */ 711 while (numvnodes - freevnodes > desiredvnodes) { 712 if (vnlruproc_sig == 0) { 713 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 714 wakeup(vnlruproc); 715 } 716 mtx_unlock(&vnode_free_list_mtx); 717 tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); 718 mtx_lock(&vnode_free_list_mtx); 719 } 720 721 /* 722 * Attempt to reuse a vnode already on the free list, allocating 723 * a new vnode if we can't find one or if we have not reached a 724 * good minimum for good LRU performance. 725 */ 726 727 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 728 int error; 729 int count; 730 731 for (count = 0; count < freevnodes; count++) { 732 vp = TAILQ_FIRST(&vnode_free_list); 733 734 KASSERT(vp->v_usecount == 0 && 735 (vp->v_iflag & VI_DOINGINACT) == 0, 736 ("getnewvnode: free vnode isn't")); 737 738 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 739 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 740 mtx_unlock(&vnode_free_list_mtx); 741 error = vtryrecycle(vp); 742 mtx_lock(&vnode_free_list_mtx); 743 if (error == 0) 744 break; 745 vp = NULL; 746 } 747 } 748 if (vp) { 749 freevnodes--; 750 mtx_unlock(&vnode_free_list_mtx); 751 752 #ifdef INVARIANTS 753 { 754 if (vp->v_data) 755 panic("cleaned vnode isn't"); 756 if (vp->v_numoutput) 757 panic("Clean vnode has pending I/O's"); 758 if (vp->v_writecount != 0) 759 panic("Non-zero write count"); 760 } 761 #endif 762 if ((pollinfo = vp->v_pollinfo) != NULL) { 763 /* 764 * To avoid lock order reversals, the call to 765 * uma_zfree() must be delayed until the vnode 766 * interlock is released. 767 */ 768 vp->v_pollinfo = NULL; 769 } 770 #ifdef MAC 771 mac_destroy_vnode(vp); 772 #endif 773 vp->v_iflag = 0; 774 vp->v_vflag = 0; 775 vp->v_lastw = 0; 776 vp->v_lasta = 0; 777 vp->v_cstart = 0; 778 vp->v_clen = 0; 779 vp->v_socket = 0; 780 lockdestroy(vp->v_vnlock); 781 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 782 KASSERT(vp->v_cleanbufcnt == 0, ("cleanbufcnt not 0")); 783 KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); 784 KASSERT(vp->v_dirtybufcnt == 0, ("dirtybufcnt not 0")); 785 KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); 786 } else { 787 numvnodes++; 788 mtx_unlock(&vnode_free_list_mtx); 789 790 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 791 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 792 VI_LOCK(vp); 793 vp->v_dd = vp; 794 vp->v_vnlock = &vp->v_lock; 795 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); 796 cache_purge(vp); /* Sets up v_id. */ 797 LIST_INIT(&vp->v_cache_src); 798 TAILQ_INIT(&vp->v_cache_dst); 799 } 800 801 TAILQ_INIT(&vp->v_cleanblkhd); 802 TAILQ_INIT(&vp->v_dirtyblkhd); 803 vp->v_type = VNON; 804 vp->v_tag = tag; 805 vp->v_op = vops; 806 *vpp = vp; 807 vp->v_usecount = 1; 808 vp->v_data = 0; 809 vp->v_cachedid = -1; 810 VI_UNLOCK(vp); 811 if (pollinfo != NULL) { 812 mtx_destroy(&pollinfo->vpi_lock); 813 uma_zfree(vnodepoll_zone, pollinfo); 814 } 815 #ifdef MAC 816 mac_init_vnode(vp); 817 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 818 mac_associate_vnode_singlelabel(mp, vp); 819 #endif 820 insmntque(vp, mp); 821 822 return (0); 823 } 824 825 /* 826 * Move a vnode from one mount queue to another. 827 */ 828 static void 829 insmntque(vp, mp) 830 register struct vnode *vp; 831 register struct mount *mp; 832 { 833 834 /* 835 * Delete from old mount point vnode list, if on one. 836 */ 837 if (vp->v_mount != NULL) { 838 MNT_ILOCK(vp->v_mount); 839 KASSERT(vp->v_mount->mnt_nvnodelistsize > 0, 840 ("bad mount point vnode list size")); 841 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 842 vp->v_mount->mnt_nvnodelistsize--; 843 MNT_IUNLOCK(vp->v_mount); 844 } 845 /* 846 * Insert into list of vnodes for the new mount point, if available. 847 */ 848 if ((vp->v_mount = mp) != NULL) { 849 MNT_ILOCK(vp->v_mount); 850 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 851 mp->mnt_nvnodelistsize++; 852 MNT_IUNLOCK(vp->v_mount); 853 } 854 } 855 856 /* 857 * Update outstanding I/O count and do wakeup if requested. 858 */ 859 void 860 vwakeup(bp) 861 register struct buf *bp; 862 { 863 register struct vnode *vp; 864 865 bp->b_flags &= ~B_WRITEINPROG; 866 if ((vp = bp->b_vp)) { 867 VI_LOCK(vp); 868 vp->v_numoutput--; 869 if (vp->v_numoutput < 0) 870 panic("vwakeup: neg numoutput"); 871 if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) { 872 vp->v_iflag &= ~VI_BWAIT; 873 wakeup(&vp->v_numoutput); 874 } 875 VI_UNLOCK(vp); 876 } 877 } 878 879 /* 880 * Flush out and invalidate all buffers associated with a vnode. 881 * Called with the underlying object locked. 882 */ 883 int 884 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 885 struct vnode *vp; 886 int flags; 887 struct ucred *cred; 888 struct thread *td; 889 int slpflag, slptimeo; 890 { 891 struct buf *blist; 892 int error; 893 vm_object_t object; 894 895 GIANT_REQUIRED; 896 897 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 898 899 VI_LOCK(vp); 900 if (flags & V_SAVE) { 901 while (vp->v_numoutput) { 902 vp->v_iflag |= VI_BWAIT; 903 error = msleep(&vp->v_numoutput, VI_MTX(vp), 904 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 905 if (error) { 906 VI_UNLOCK(vp); 907 return (error); 908 } 909 } 910 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 911 VI_UNLOCK(vp); 912 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 913 return (error); 914 /* 915 * XXX We could save a lock/unlock if this was only 916 * enabled under INVARIANTS 917 */ 918 VI_LOCK(vp); 919 if (vp->v_numoutput > 0 || 920 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 921 panic("vinvalbuf: dirty bufs"); 922 } 923 } 924 /* 925 * If you alter this loop please notice that interlock is dropped and 926 * reacquired in flushbuflist. Special care is needed to ensure that 927 * no race conditions occur from this. 928 */ 929 for (error = 0;;) { 930 if ((blist = TAILQ_FIRST(&vp->v_cleanblkhd)) != 0 && 931 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 932 if (error) 933 break; 934 continue; 935 } 936 if ((blist = TAILQ_FIRST(&vp->v_dirtyblkhd)) != 0 && 937 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 938 if (error) 939 break; 940 continue; 941 } 942 break; 943 } 944 if (error) { 945 VI_UNLOCK(vp); 946 return (error); 947 } 948 949 /* 950 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 951 * have write I/O in-progress but if there is a VM object then the 952 * VM object can also have read-I/O in-progress. 953 */ 954 do { 955 while (vp->v_numoutput > 0) { 956 vp->v_iflag |= VI_BWAIT; 957 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0); 958 } 959 VI_UNLOCK(vp); 960 if (VOP_GETVOBJECT(vp, &object) == 0) { 961 VM_OBJECT_LOCK(object); 962 vm_object_pip_wait(object, "vnvlbx"); 963 VM_OBJECT_UNLOCK(object); 964 } 965 VI_LOCK(vp); 966 } while (vp->v_numoutput > 0); 967 VI_UNLOCK(vp); 968 969 /* 970 * Destroy the copy in the VM cache, too. 971 */ 972 if (VOP_GETVOBJECT(vp, &object) == 0) { 973 VM_OBJECT_LOCK(object); 974 vm_object_page_remove(object, 0, 0, 975 (flags & V_SAVE) ? TRUE : FALSE); 976 VM_OBJECT_UNLOCK(object); 977 } 978 979 #ifdef INVARIANTS 980 VI_LOCK(vp); 981 if ((flags & (V_ALT | V_NORMAL)) == 0 && 982 (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || 983 !TAILQ_EMPTY(&vp->v_cleanblkhd))) 984 panic("vinvalbuf: flush failed"); 985 VI_UNLOCK(vp); 986 #endif 987 return (0); 988 } 989 990 /* 991 * Flush out buffers on the specified list. 992 * 993 */ 994 static int 995 flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) 996 struct buf *blist; 997 int flags; 998 struct vnode *vp; 999 int slpflag, slptimeo; 1000 int *errorp; 1001 { 1002 struct buf *bp, *nbp; 1003 int found, error; 1004 1005 ASSERT_VI_LOCKED(vp, "flushbuflist"); 1006 1007 for (found = 0, bp = blist; bp; bp = nbp) { 1008 nbp = TAILQ_NEXT(bp, b_vnbufs); 1009 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1010 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1011 continue; 1012 } 1013 found += 1; 1014 error = BUF_TIMELOCK(bp, 1015 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), 1016 "flushbuf", slpflag, slptimeo); 1017 if (error) { 1018 if (error != ENOLCK) 1019 *errorp = error; 1020 goto done; 1021 } 1022 /* 1023 * XXX Since there are no node locks for NFS, I 1024 * believe there is a slight chance that a delayed 1025 * write will occur while sleeping just above, so 1026 * check for it. Note that vfs_bio_awrite expects 1027 * buffers to reside on a queue, while bwrite and 1028 * brelse do not. 1029 */ 1030 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1031 (flags & V_SAVE)) { 1032 1033 if (bp->b_vp == vp) { 1034 if (bp->b_flags & B_CLUSTEROK) { 1035 vfs_bio_awrite(bp); 1036 } else { 1037 bremfree(bp); 1038 bp->b_flags |= B_ASYNC; 1039 bwrite(bp); 1040 } 1041 } else { 1042 bremfree(bp); 1043 (void) bwrite(bp); 1044 } 1045 goto done; 1046 } 1047 bremfree(bp); 1048 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1049 bp->b_flags &= ~B_ASYNC; 1050 brelse(bp); 1051 VI_LOCK(vp); 1052 } 1053 return (found); 1054 done: 1055 VI_LOCK(vp); 1056 return (found); 1057 } 1058 1059 /* 1060 * Truncate a file's buffer and pages to a specified length. This 1061 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1062 * sync activity. 1063 */ 1064 int 1065 vtruncbuf(vp, cred, td, length, blksize) 1066 register struct vnode *vp; 1067 struct ucred *cred; 1068 struct thread *td; 1069 off_t length; 1070 int blksize; 1071 { 1072 register struct buf *bp; 1073 struct buf *nbp; 1074 int anyfreed; 1075 int trunclbn; 1076 1077 /* 1078 * Round up to the *next* lbn. 1079 */ 1080 trunclbn = (length + blksize - 1) / blksize; 1081 1082 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1083 restart: 1084 VI_LOCK(vp); 1085 anyfreed = 1; 1086 for (;anyfreed;) { 1087 anyfreed = 0; 1088 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 1089 nbp = TAILQ_NEXT(bp, b_vnbufs); 1090 if (bp->b_lblkno >= trunclbn) { 1091 if (BUF_LOCK(bp, 1092 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1093 VI_MTX(vp)) == ENOLCK) 1094 goto restart; 1095 1096 bremfree(bp); 1097 bp->b_flags |= (B_INVAL | B_RELBUF); 1098 bp->b_flags &= ~B_ASYNC; 1099 brelse(bp); 1100 anyfreed = 1; 1101 1102 if (nbp && 1103 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1104 (nbp->b_vp != vp) || 1105 (nbp->b_flags & B_DELWRI))) { 1106 goto restart; 1107 } 1108 VI_LOCK(vp); 1109 } 1110 } 1111 1112 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1113 nbp = TAILQ_NEXT(bp, b_vnbufs); 1114 if (bp->b_lblkno >= trunclbn) { 1115 if (BUF_LOCK(bp, 1116 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1117 VI_MTX(vp)) == ENOLCK) 1118 goto restart; 1119 bremfree(bp); 1120 bp->b_flags |= (B_INVAL | B_RELBUF); 1121 bp->b_flags &= ~B_ASYNC; 1122 brelse(bp); 1123 anyfreed = 1; 1124 if (nbp && 1125 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1126 (nbp->b_vp != vp) || 1127 (nbp->b_flags & B_DELWRI) == 0)) { 1128 goto restart; 1129 } 1130 VI_LOCK(vp); 1131 } 1132 } 1133 } 1134 1135 if (length > 0) { 1136 restartsync: 1137 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1138 nbp = TAILQ_NEXT(bp, b_vnbufs); 1139 if (bp->b_lblkno > 0) 1140 continue; 1141 /* 1142 * Since we hold the vnode lock this should only 1143 * fail if we're racing with the buf daemon. 1144 */ 1145 if (BUF_LOCK(bp, 1146 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1147 VI_MTX(vp)) == ENOLCK) { 1148 goto restart; 1149 } 1150 KASSERT((bp->b_flags & B_DELWRI), 1151 ("buf(%p) on dirty queue without DELWRI", bp)); 1152 1153 bremfree(bp); 1154 bawrite(bp); 1155 VI_LOCK(vp); 1156 goto restartsync; 1157 } 1158 } 1159 1160 while (vp->v_numoutput > 0) { 1161 vp->v_iflag |= VI_BWAIT; 1162 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0); 1163 } 1164 VI_UNLOCK(vp); 1165 vnode_pager_setsize(vp, length); 1166 1167 return (0); 1168 } 1169 1170 /* 1171 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1172 * a vnode. 1173 * 1174 * NOTE: We have to deal with the special case of a background bitmap 1175 * buffer, a situation where two buffers will have the same logical 1176 * block offset. We want (1) only the foreground buffer to be accessed 1177 * in a lookup and (2) must differentiate between the foreground and 1178 * background buffer in the splay tree algorithm because the splay 1179 * tree cannot normally handle multiple entities with the same 'index'. 1180 * We accomplish this by adding differentiating flags to the splay tree's 1181 * numerical domain. 1182 */ 1183 static 1184 struct buf * 1185 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1186 { 1187 struct buf dummy; 1188 struct buf *lefttreemax, *righttreemin, *y; 1189 1190 if (root == NULL) 1191 return (NULL); 1192 lefttreemax = righttreemin = &dummy; 1193 for (;;) { 1194 if (lblkno < root->b_lblkno || 1195 (lblkno == root->b_lblkno && 1196 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1197 if ((y = root->b_left) == NULL) 1198 break; 1199 if (lblkno < y->b_lblkno) { 1200 /* Rotate right. */ 1201 root->b_left = y->b_right; 1202 y->b_right = root; 1203 root = y; 1204 if ((y = root->b_left) == NULL) 1205 break; 1206 } 1207 /* Link into the new root's right tree. */ 1208 righttreemin->b_left = root; 1209 righttreemin = root; 1210 } else if (lblkno > root->b_lblkno || 1211 (lblkno == root->b_lblkno && 1212 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1213 if ((y = root->b_right) == NULL) 1214 break; 1215 if (lblkno > y->b_lblkno) { 1216 /* Rotate left. */ 1217 root->b_right = y->b_left; 1218 y->b_left = root; 1219 root = y; 1220 if ((y = root->b_right) == NULL) 1221 break; 1222 } 1223 /* Link into the new root's left tree. */ 1224 lefttreemax->b_right = root; 1225 lefttreemax = root; 1226 } else { 1227 break; 1228 } 1229 root = y; 1230 } 1231 /* Assemble the new root. */ 1232 lefttreemax->b_right = root->b_left; 1233 righttreemin->b_left = root->b_right; 1234 root->b_left = dummy.b_right; 1235 root->b_right = dummy.b_left; 1236 return (root); 1237 } 1238 1239 static 1240 void 1241 buf_vlist_remove(struct buf *bp) 1242 { 1243 struct vnode *vp = bp->b_vp; 1244 struct buf *root; 1245 1246 ASSERT_VI_LOCKED(vp, "buf_vlist_remove"); 1247 if (bp->b_xflags & BX_VNDIRTY) { 1248 if (bp != vp->v_dirtyblkroot) { 1249 root = buf_splay(bp->b_lblkno, bp->b_xflags, 1250 vp->v_dirtyblkroot); 1251 KASSERT(root == bp, 1252 ("splay lookup failed during dirty remove")); 1253 } 1254 if (bp->b_left == NULL) { 1255 root = bp->b_right; 1256 } else { 1257 root = buf_splay(bp->b_lblkno, bp->b_xflags, 1258 bp->b_left); 1259 root->b_right = bp->b_right; 1260 } 1261 vp->v_dirtyblkroot = root; 1262 TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); 1263 vp->v_dirtybufcnt--; 1264 } else { 1265 /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ 1266 if (bp != vp->v_cleanblkroot) { 1267 root = buf_splay(bp->b_lblkno, bp->b_xflags, 1268 vp->v_cleanblkroot); 1269 KASSERT(root == bp, 1270 ("splay lookup failed during clean 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, 1276 bp->b_left); 1277 root->b_right = bp->b_right; 1278 } 1279 vp->v_cleanblkroot = root; 1280 TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); 1281 vp->v_cleanbufcnt--; 1282 } 1283 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1284 } 1285 1286 /* 1287 * Add the buffer to the sorted clean or dirty block list using a 1288 * splay tree algorithm. 1289 * 1290 * NOTE: xflags is passed as a constant, optimizing this inline function! 1291 */ 1292 static 1293 void 1294 buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) 1295 { 1296 struct buf *root; 1297 1298 ASSERT_VI_LOCKED(vp, "buf_vlist_add"); 1299 bp->b_xflags |= xflags; 1300 if (xflags & BX_VNDIRTY) { 1301 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1302 if (root == NULL) { 1303 bp->b_left = NULL; 1304 bp->b_right = NULL; 1305 TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); 1306 } else if (bp->b_lblkno < root->b_lblkno || 1307 (bp->b_lblkno == root->b_lblkno && 1308 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1309 bp->b_left = root->b_left; 1310 bp->b_right = root; 1311 root->b_left = NULL; 1312 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1313 } else { 1314 bp->b_right = root->b_right; 1315 bp->b_left = root; 1316 root->b_right = NULL; 1317 TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, 1318 root, bp, b_vnbufs); 1319 } 1320 vp->v_dirtybufcnt++; 1321 vp->v_dirtyblkroot = bp; 1322 } else { 1323 /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ 1324 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1325 if (root == NULL) { 1326 bp->b_left = NULL; 1327 bp->b_right = NULL; 1328 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1329 } else if (bp->b_lblkno < root->b_lblkno || 1330 (bp->b_lblkno == root->b_lblkno && 1331 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1332 bp->b_left = root->b_left; 1333 bp->b_right = root; 1334 root->b_left = NULL; 1335 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1336 } else { 1337 bp->b_right = root->b_right; 1338 bp->b_left = root; 1339 root->b_right = NULL; 1340 TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, 1341 root, bp, b_vnbufs); 1342 } 1343 vp->v_cleanbufcnt++; 1344 vp->v_cleanblkroot = bp; 1345 } 1346 } 1347 1348 /* 1349 * Lookup a buffer using the splay tree. Note that we specifically avoid 1350 * shadow buffers used in background bitmap writes. 1351 * 1352 * This code isn't quite efficient as it could be because we are maintaining 1353 * two sorted lists and do not know which list the block resides in. 1354 * 1355 * During a "make buildworld" the desired buffer is found at one of 1356 * the roots more than 60% of the time. Thus, checking both roots 1357 * before performing either splay eliminates unnecessary splays on the 1358 * first tree splayed. 1359 */ 1360 struct buf * 1361 gbincore(struct vnode *vp, daddr_t lblkno) 1362 { 1363 struct buf *bp; 1364 1365 GIANT_REQUIRED; 1366 1367 ASSERT_VI_LOCKED(vp, "gbincore"); 1368 if ((bp = vp->v_cleanblkroot) != NULL && 1369 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1370 return (bp); 1371 if ((bp = vp->v_dirtyblkroot) != NULL && 1372 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1373 return (bp); 1374 if ((bp = vp->v_cleanblkroot) != NULL) { 1375 vp->v_cleanblkroot = bp = buf_splay(lblkno, 0, bp); 1376 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1377 return (bp); 1378 } 1379 if ((bp = vp->v_dirtyblkroot) != NULL) { 1380 vp->v_dirtyblkroot = bp = buf_splay(lblkno, 0, bp); 1381 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1382 return (bp); 1383 } 1384 return (NULL); 1385 } 1386 1387 /* 1388 * Associate a buffer with a vnode. 1389 */ 1390 void 1391 bgetvp(vp, bp) 1392 register struct vnode *vp; 1393 register struct buf *bp; 1394 { 1395 1396 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1397 1398 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1399 ("bgetvp: bp already attached! %p", bp)); 1400 1401 ASSERT_VI_LOCKED(vp, "bgetvp"); 1402 vholdl(vp); 1403 bp->b_vp = vp; 1404 bp->b_dev = vn_todev(vp); 1405 /* 1406 * Insert onto list for new vnode. 1407 */ 1408 buf_vlist_add(bp, vp, BX_VNCLEAN); 1409 } 1410 1411 /* 1412 * Disassociate a buffer from a vnode. 1413 */ 1414 void 1415 brelvp(bp) 1416 register struct buf *bp; 1417 { 1418 struct vnode *vp; 1419 1420 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1421 1422 /* 1423 * Delete from old vnode list, if on one. 1424 */ 1425 vp = bp->b_vp; 1426 VI_LOCK(vp); 1427 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1428 buf_vlist_remove(bp); 1429 if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1430 vp->v_iflag &= ~VI_ONWORKLST; 1431 mtx_lock(&sync_mtx); 1432 LIST_REMOVE(vp, v_synclist); 1433 mtx_unlock(&sync_mtx); 1434 } 1435 vdropl(vp); 1436 bp->b_vp = (struct vnode *) 0; 1437 if (bp->b_object) 1438 bp->b_object = NULL; 1439 VI_UNLOCK(vp); 1440 } 1441 1442 /* 1443 * Add an item to the syncer work queue. 1444 */ 1445 static void 1446 vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1447 { 1448 int slot; 1449 1450 ASSERT_VI_LOCKED(vp, "vn_syncer_add_to_worklist"); 1451 1452 mtx_lock(&sync_mtx); 1453 if (vp->v_iflag & VI_ONWORKLST) 1454 LIST_REMOVE(vp, v_synclist); 1455 else 1456 vp->v_iflag |= VI_ONWORKLST; 1457 1458 if (delay > syncer_maxdelay - 2) 1459 delay = syncer_maxdelay - 2; 1460 slot = (syncer_delayno + delay) & syncer_mask; 1461 1462 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1463 mtx_unlock(&sync_mtx); 1464 } 1465 1466 struct proc *updateproc; 1467 static void sched_sync(void); 1468 static struct kproc_desc up_kp = { 1469 "syncer", 1470 sched_sync, 1471 &updateproc 1472 }; 1473 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1474 1475 /* 1476 * System filesystem synchronizer daemon. 1477 */ 1478 static void 1479 sched_sync(void) 1480 { 1481 struct synclist *next; 1482 struct synclist *slp; 1483 struct vnode *vp; 1484 struct mount *mp; 1485 long starttime; 1486 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); 1487 1488 mtx_lock(&Giant); 1489 1490 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, 1491 SHUTDOWN_PRI_LAST); 1492 1493 for (;;) { 1494 kthread_suspend_check(td->td_proc); 1495 1496 starttime = time_second; 1497 1498 /* 1499 * Push files whose dirty time has expired. Be careful 1500 * of interrupt race on slp queue. 1501 */ 1502 mtx_lock(&sync_mtx); 1503 slp = &syncer_workitem_pending[syncer_delayno]; 1504 syncer_delayno += 1; 1505 if (syncer_delayno == syncer_maxdelay) 1506 syncer_delayno = 0; 1507 next = &syncer_workitem_pending[syncer_delayno]; 1508 1509 while ((vp = LIST_FIRST(slp)) != NULL) { 1510 if (VOP_ISLOCKED(vp, NULL) != 0 || 1511 vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1512 LIST_REMOVE(vp, v_synclist); 1513 LIST_INSERT_HEAD(next, vp, v_synclist); 1514 continue; 1515 } 1516 if (VI_TRYLOCK(vp) == 0) { 1517 LIST_REMOVE(vp, v_synclist); 1518 LIST_INSERT_HEAD(next, vp, v_synclist); 1519 vn_finished_write(mp); 1520 continue; 1521 } 1522 /* 1523 * We use vhold in case the vnode does not 1524 * successfully sync. vhold prevents the vnode from 1525 * going away when we unlock the sync_mtx so that 1526 * we can acquire the vnode interlock. 1527 */ 1528 vholdl(vp); 1529 mtx_unlock(&sync_mtx); 1530 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td); 1531 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1532 VOP_UNLOCK(vp, 0, td); 1533 vn_finished_write(mp); 1534 VI_LOCK(vp); 1535 if ((vp->v_iflag & VI_ONWORKLST) != 0) { 1536 /* 1537 * Put us back on the worklist. The worklist 1538 * routine will remove us from our current 1539 * position and then add us back in at a later 1540 * position. 1541 */ 1542 vn_syncer_add_to_worklist(vp, syncdelay); 1543 } 1544 vdropl(vp); 1545 VI_UNLOCK(vp); 1546 mtx_lock(&sync_mtx); 1547 } 1548 mtx_unlock(&sync_mtx); 1549 1550 /* 1551 * Do soft update processing. 1552 */ 1553 if (softdep_process_worklist_hook != NULL) 1554 (*softdep_process_worklist_hook)(NULL); 1555 1556 /* 1557 * The variable rushjob allows the kernel to speed up the 1558 * processing of the filesystem syncer process. A rushjob 1559 * value of N tells the filesystem syncer to process the next 1560 * N seconds worth of work on its queue ASAP. Currently rushjob 1561 * is used by the soft update code to speed up the filesystem 1562 * syncer process when the incore state is getting so far 1563 * ahead of the disk that the kernel memory pool is being 1564 * threatened with exhaustion. 1565 */ 1566 mtx_lock(&sync_mtx); 1567 if (rushjob > 0) { 1568 rushjob -= 1; 1569 mtx_unlock(&sync_mtx); 1570 continue; 1571 } 1572 mtx_unlock(&sync_mtx); 1573 /* 1574 * If it has taken us less than a second to process the 1575 * current work, then wait. Otherwise start right over 1576 * again. We can still lose time if any single round 1577 * takes more than two seconds, but it does not really 1578 * matter as we are just trying to generally pace the 1579 * filesystem activity. 1580 */ 1581 if (time_second == starttime) 1582 tsleep(&lbolt, PPAUSE, "syncer", 0); 1583 } 1584 } 1585 1586 /* 1587 * Request the syncer daemon to speed up its work. 1588 * We never push it to speed up more than half of its 1589 * normal turn time, otherwise it could take over the cpu. 1590 */ 1591 int 1592 speedup_syncer() 1593 { 1594 struct thread *td; 1595 int ret = 0; 1596 1597 td = FIRST_THREAD_IN_PROC(updateproc); 1598 sleepq_remove(td, &lbolt); 1599 mtx_lock(&sync_mtx); 1600 if (rushjob < syncdelay / 2) { 1601 rushjob += 1; 1602 stat_rush_requests += 1; 1603 ret = 1; 1604 } 1605 mtx_unlock(&sync_mtx); 1606 return (ret); 1607 } 1608 1609 /* 1610 * Associate a p-buffer with a vnode. 1611 * 1612 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1613 * with the buffer. i.e. the bp has not been linked into the vnode or 1614 * ref-counted. 1615 */ 1616 void 1617 pbgetvp(vp, bp) 1618 register struct vnode *vp; 1619 register struct buf *bp; 1620 { 1621 1622 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1623 1624 bp->b_vp = vp; 1625 bp->b_object = vp->v_object; 1626 bp->b_flags |= B_PAGING; 1627 bp->b_dev = vn_todev(vp); 1628 } 1629 1630 /* 1631 * Disassociate a p-buffer from a vnode. 1632 */ 1633 void 1634 pbrelvp(bp) 1635 register struct buf *bp; 1636 { 1637 1638 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1639 1640 /* XXX REMOVE ME */ 1641 VI_LOCK(bp->b_vp); 1642 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1643 panic( 1644 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1645 bp, 1646 (int)bp->b_flags 1647 ); 1648 } 1649 VI_UNLOCK(bp->b_vp); 1650 bp->b_vp = (struct vnode *) 0; 1651 bp->b_object = NULL; 1652 bp->b_flags &= ~B_PAGING; 1653 } 1654 1655 /* 1656 * Reassign a buffer from one vnode to another. 1657 * Used to assign file specific control information 1658 * (indirect blocks) to the vnode to which they belong. 1659 */ 1660 void 1661 reassignbuf(bp, newvp) 1662 register struct buf *bp; 1663 register struct vnode *newvp; 1664 { 1665 struct vnode *vp; 1666 int delay; 1667 1668 if (newvp == NULL) { 1669 printf("reassignbuf: NULL"); 1670 return; 1671 } 1672 vp = bp->b_vp; 1673 ++reassignbufcalls; 1674 1675 /* 1676 * B_PAGING flagged buffers cannot be reassigned because their vp 1677 * is not fully linked in. 1678 */ 1679 if (bp->b_flags & B_PAGING) 1680 panic("cannot reassign paging buffer"); 1681 1682 /* 1683 * Delete from old vnode list, if on one. 1684 */ 1685 VI_LOCK(vp); 1686 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1687 buf_vlist_remove(bp); 1688 if (vp != newvp) { 1689 vdropl(bp->b_vp); 1690 bp->b_vp = NULL; /* for clarification */ 1691 } 1692 } 1693 if (vp != newvp) { 1694 VI_UNLOCK(vp); 1695 VI_LOCK(newvp); 1696 } 1697 /* 1698 * If dirty, put on list of dirty buffers; otherwise insert onto list 1699 * of clean buffers. 1700 */ 1701 if (bp->b_flags & B_DELWRI) { 1702 if ((newvp->v_iflag & VI_ONWORKLST) == 0) { 1703 switch (newvp->v_type) { 1704 case VDIR: 1705 delay = dirdelay; 1706 break; 1707 case VCHR: 1708 if (newvp->v_rdev->si_mountpoint != NULL) { 1709 delay = metadelay; 1710 break; 1711 } 1712 /* FALLTHROUGH */ 1713 default: 1714 delay = filedelay; 1715 } 1716 vn_syncer_add_to_worklist(newvp, delay); 1717 } 1718 buf_vlist_add(bp, newvp, BX_VNDIRTY); 1719 } else { 1720 buf_vlist_add(bp, newvp, BX_VNCLEAN); 1721 1722 if ((newvp->v_iflag & VI_ONWORKLST) && 1723 TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { 1724 mtx_lock(&sync_mtx); 1725 LIST_REMOVE(newvp, v_synclist); 1726 mtx_unlock(&sync_mtx); 1727 newvp->v_iflag &= ~VI_ONWORKLST; 1728 } 1729 } 1730 if (bp->b_vp != newvp) { 1731 bp->b_vp = newvp; 1732 vholdl(bp->b_vp); 1733 } 1734 VI_UNLOCK(newvp); 1735 } 1736 1737 /* 1738 * Create a vnode for a device. 1739 * Used for mounting the root filesystem. 1740 */ 1741 int 1742 bdevvp(dev, vpp) 1743 dev_t dev; 1744 struct vnode **vpp; 1745 { 1746 register struct vnode *vp; 1747 struct vnode *nvp; 1748 int error; 1749 1750 if (dev == NODEV) { 1751 *vpp = NULLVP; 1752 return (ENXIO); 1753 } 1754 if (vfinddev(dev, vpp)) 1755 return (0); 1756 1757 error = getnewvnode("none", (struct mount *)0, spec_vnodeop_p, &nvp); 1758 if (error) { 1759 *vpp = NULLVP; 1760 return (error); 1761 } 1762 vp = nvp; 1763 vp->v_type = VCHR; 1764 addalias(vp, dev); 1765 *vpp = vp; 1766 return (0); 1767 } 1768 1769 static void 1770 v_incr_usecount(struct vnode *vp, int delta) 1771 { 1772 1773 vp->v_usecount += delta; 1774 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1775 mtx_lock(&spechash_mtx); 1776 vp->v_rdev->si_usecount += delta; 1777 mtx_unlock(&spechash_mtx); 1778 } 1779 } 1780 1781 /* 1782 * Add vnode to the alias list hung off the dev_t. 1783 * 1784 * The reason for this gunk is that multiple vnodes can reference 1785 * the same physical device, so checking vp->v_usecount to see 1786 * how many users there are is inadequate; the v_usecount for 1787 * the vnodes need to be accumulated. vcount() does that. 1788 */ 1789 struct vnode * 1790 addaliasu(nvp, nvp_rdev) 1791 struct vnode *nvp; 1792 udev_t nvp_rdev; 1793 { 1794 struct vnode *ovp; 1795 vop_t **ops; 1796 dev_t dev; 1797 1798 if (nvp->v_type == VBLK) 1799 return (nvp); 1800 if (nvp->v_type != VCHR) 1801 panic("addaliasu on non-special vnode"); 1802 dev = udev2dev(nvp_rdev); 1803 if (dev == NODEV) 1804 return (nvp); 1805 /* 1806 * Check to see if we have a bdevvp vnode with no associated 1807 * filesystem. If so, we want to associate the filesystem of 1808 * the new newly instigated vnode with the bdevvp vnode and 1809 * discard the newly created vnode rather than leaving the 1810 * bdevvp vnode lying around with no associated filesystem. 1811 */ 1812 if (vfinddev(dev, &ovp) == 0 || ovp->v_data != NULL) { 1813 addalias(nvp, dev); 1814 return (nvp); 1815 } 1816 /* 1817 * Discard unneeded vnode, but save its node specific data. 1818 * Note that if there is a lock, it is carried over in the 1819 * node specific data to the replacement vnode. 1820 */ 1821 vref(ovp); 1822 ovp->v_data = nvp->v_data; 1823 ovp->v_tag = nvp->v_tag; 1824 nvp->v_data = NULL; 1825 lockdestroy(ovp->v_vnlock); 1826 lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, 1827 nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); 1828 ops = ovp->v_op; 1829 ovp->v_op = nvp->v_op; 1830 if (VOP_ISLOCKED(nvp, curthread)) { 1831 VOP_UNLOCK(nvp, 0, curthread); 1832 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 1833 } 1834 nvp->v_op = ops; 1835 insmntque(ovp, nvp->v_mount); 1836 vrele(nvp); 1837 vgone(nvp); 1838 return (ovp); 1839 } 1840 1841 /* This is a local helper function that do the same as addaliasu, but for a 1842 * dev_t instead of an udev_t. */ 1843 static void 1844 addalias(nvp, dev) 1845 struct vnode *nvp; 1846 dev_t dev; 1847 { 1848 1849 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 1850 dev_ref(dev); 1851 nvp->v_rdev = dev; 1852 VI_LOCK(nvp); 1853 mtx_lock(&spechash_mtx); 1854 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 1855 dev->si_usecount += nvp->v_usecount; 1856 mtx_unlock(&spechash_mtx); 1857 VI_UNLOCK(nvp); 1858 } 1859 1860 /* 1861 * Grab a particular vnode from the free list, increment its 1862 * reference count and lock it. The vnode lock bit is set if the 1863 * vnode is being eliminated in vgone. The process is awakened 1864 * when the transition is completed, and an error returned to 1865 * indicate that the vnode is no longer usable (possibly having 1866 * been changed to a new filesystem type). 1867 */ 1868 int 1869 vget(vp, flags, td) 1870 register struct vnode *vp; 1871 int flags; 1872 struct thread *td; 1873 { 1874 int error; 1875 1876 /* 1877 * If the vnode is in the process of being cleaned out for 1878 * another use, we wait for the cleaning to finish and then 1879 * return failure. Cleaning is determined by checking that 1880 * the VI_XLOCK flag is set. 1881 */ 1882 if ((flags & LK_INTERLOCK) == 0) 1883 VI_LOCK(vp); 1884 if (vp->v_iflag & VI_XLOCK && vp->v_vxthread != curthread) { 1885 if ((flags & LK_NOWAIT) == 0) { 1886 vp->v_iflag |= VI_XWANT; 1887 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); 1888 return (ENOENT); 1889 } 1890 VI_UNLOCK(vp); 1891 return (EBUSY); 1892 } 1893 1894 v_incr_usecount(vp, 1); 1895 1896 if (VSHOULDBUSY(vp)) 1897 vbusy(vp); 1898 if (flags & LK_TYPE_MASK) { 1899 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 1900 /* 1901 * must expand vrele here because we do not want 1902 * to call VOP_INACTIVE if the reference count 1903 * drops back to zero since it was never really 1904 * active. We must remove it from the free list 1905 * before sleeping so that multiple processes do 1906 * not try to recycle it. 1907 */ 1908 VI_LOCK(vp); 1909 v_incr_usecount(vp, -1); 1910 if (VSHOULDFREE(vp)) 1911 vfree(vp); 1912 else 1913 vlruvp(vp); 1914 VI_UNLOCK(vp); 1915 } 1916 return (error); 1917 } 1918 VI_UNLOCK(vp); 1919 return (0); 1920 } 1921 1922 /* 1923 * Increase the reference count of a vnode. 1924 */ 1925 void 1926 vref(struct vnode *vp) 1927 { 1928 1929 VI_LOCK(vp); 1930 v_incr_usecount(vp, 1); 1931 VI_UNLOCK(vp); 1932 } 1933 1934 /* 1935 * Return reference count of a vnode. 1936 * 1937 * The results of this call are only guaranteed when some mechanism other 1938 * than the VI lock is used to stop other processes from gaining references 1939 * to the vnode. This may be the case if the caller holds the only reference. 1940 * This is also useful when stale data is acceptable as race conditions may 1941 * be accounted for by some other means. 1942 */ 1943 int 1944 vrefcnt(struct vnode *vp) 1945 { 1946 int usecnt; 1947 1948 VI_LOCK(vp); 1949 usecnt = vp->v_usecount; 1950 VI_UNLOCK(vp); 1951 1952 return (usecnt); 1953 } 1954 1955 1956 /* 1957 * Vnode put/release. 1958 * If count drops to zero, call inactive routine and return to freelist. 1959 */ 1960 void 1961 vrele(vp) 1962 struct vnode *vp; 1963 { 1964 struct thread *td = curthread; /* XXX */ 1965 1966 KASSERT(vp != NULL, ("vrele: null vp")); 1967 1968 VI_LOCK(vp); 1969 1970 /* Skip this v_writecount check if we're going to panic below. */ 1971 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 1972 ("vrele: missed vn_close")); 1973 1974 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 1975 vp->v_usecount == 1)) { 1976 v_incr_usecount(vp, -1); 1977 VI_UNLOCK(vp); 1978 1979 return; 1980 } 1981 1982 if (vp->v_usecount == 1) { 1983 v_incr_usecount(vp, -1); 1984 /* 1985 * We must call VOP_INACTIVE with the node locked. Mark 1986 * as VI_DOINGINACT to avoid recursion. 1987 */ 1988 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 1989 VI_LOCK(vp); 1990 vp->v_iflag |= VI_DOINGINACT; 1991 VI_UNLOCK(vp); 1992 VOP_INACTIVE(vp, td); 1993 VI_LOCK(vp); 1994 KASSERT(vp->v_iflag & VI_DOINGINACT, 1995 ("vrele: lost VI_DOINGINACT")); 1996 vp->v_iflag &= ~VI_DOINGINACT; 1997 } else 1998 VI_LOCK(vp); 1999 if (VSHOULDFREE(vp)) 2000 vfree(vp); 2001 else 2002 vlruvp(vp); 2003 VI_UNLOCK(vp); 2004 2005 } else { 2006 #ifdef DIAGNOSTIC 2007 vprint("vrele: negative ref count", vp); 2008 #endif 2009 VI_UNLOCK(vp); 2010 panic("vrele: negative ref cnt"); 2011 } 2012 } 2013 2014 /* 2015 * Release an already locked vnode. This give the same effects as 2016 * unlock+vrele(), but takes less time and avoids releasing and 2017 * re-aquiring the lock (as vrele() aquires the lock internally.) 2018 */ 2019 void 2020 vput(vp) 2021 struct vnode *vp; 2022 { 2023 struct thread *td = curthread; /* XXX */ 2024 2025 GIANT_REQUIRED; 2026 2027 KASSERT(vp != NULL, ("vput: null vp")); 2028 VI_LOCK(vp); 2029 /* Skip this v_writecount check if we're going to panic below. */ 2030 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2031 ("vput: missed vn_close")); 2032 2033 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2034 vp->v_usecount == 1)) { 2035 v_incr_usecount(vp, -1); 2036 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2037 return; 2038 } 2039 2040 if (vp->v_usecount == 1) { 2041 v_incr_usecount(vp, -1); 2042 /* 2043 * We must call VOP_INACTIVE with the node locked, so 2044 * we just need to release the vnode mutex. Mark as 2045 * as VI_DOINGINACT to avoid recursion. 2046 */ 2047 vp->v_iflag |= VI_DOINGINACT; 2048 VI_UNLOCK(vp); 2049 VOP_INACTIVE(vp, td); 2050 VI_LOCK(vp); 2051 KASSERT(vp->v_iflag & VI_DOINGINACT, 2052 ("vput: lost VI_DOINGINACT")); 2053 vp->v_iflag &= ~VI_DOINGINACT; 2054 if (VSHOULDFREE(vp)) 2055 vfree(vp); 2056 else 2057 vlruvp(vp); 2058 VI_UNLOCK(vp); 2059 2060 } else { 2061 #ifdef DIAGNOSTIC 2062 vprint("vput: negative ref count", vp); 2063 #endif 2064 panic("vput: negative ref cnt"); 2065 } 2066 } 2067 2068 /* 2069 * Somebody doesn't want the vnode recycled. 2070 */ 2071 void 2072 vhold(struct vnode *vp) 2073 { 2074 2075 VI_LOCK(vp); 2076 vholdl(vp); 2077 VI_UNLOCK(vp); 2078 } 2079 2080 void 2081 vholdl(vp) 2082 register struct vnode *vp; 2083 { 2084 2085 vp->v_holdcnt++; 2086 if (VSHOULDBUSY(vp)) 2087 vbusy(vp); 2088 } 2089 2090 /* 2091 * Note that there is one less who cares about this vnode. vdrop() is the 2092 * opposite of vhold(). 2093 */ 2094 void 2095 vdrop(struct vnode *vp) 2096 { 2097 2098 VI_LOCK(vp); 2099 vdropl(vp); 2100 VI_UNLOCK(vp); 2101 } 2102 2103 void 2104 vdropl(vp) 2105 register struct vnode *vp; 2106 { 2107 2108 if (vp->v_holdcnt <= 0) 2109 panic("vdrop: holdcnt"); 2110 vp->v_holdcnt--; 2111 if (VSHOULDFREE(vp)) 2112 vfree(vp); 2113 else 2114 vlruvp(vp); 2115 } 2116 2117 /* 2118 * Remove any vnodes in the vnode table belonging to mount point mp. 2119 * 2120 * If FORCECLOSE is not specified, there should not be any active ones, 2121 * return error if any are found (nb: this is a user error, not a 2122 * system error). If FORCECLOSE is specified, detach any active vnodes 2123 * that are found. 2124 * 2125 * If WRITECLOSE is set, only flush out regular file vnodes open for 2126 * writing. 2127 * 2128 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2129 * 2130 * `rootrefs' specifies the base reference count for the root vnode 2131 * of this filesystem. The root vnode is considered busy if its 2132 * v_usecount exceeds this value. On a successful return, vflush() 2133 * will call vrele() on the root vnode exactly rootrefs times. 2134 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2135 * be zero. 2136 */ 2137 #ifdef DIAGNOSTIC 2138 static int busyprt = 0; /* print out busy vnodes */ 2139 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2140 #endif 2141 2142 int 2143 vflush(mp, rootrefs, flags) 2144 struct mount *mp; 2145 int rootrefs; 2146 int flags; 2147 { 2148 struct thread *td = curthread; /* XXX */ 2149 struct vnode *vp, *nvp, *rootvp = NULL; 2150 struct vattr vattr; 2151 int busy = 0, error; 2152 2153 if (rootrefs > 0) { 2154 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2155 ("vflush: bad args")); 2156 /* 2157 * Get the filesystem root vnode. We can vput() it 2158 * immediately, since with rootrefs > 0, it won't go away. 2159 */ 2160 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 2161 return (error); 2162 vput(rootvp); 2163 2164 } 2165 MNT_ILOCK(mp); 2166 loop: 2167 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 2168 /* 2169 * Make sure this vnode wasn't reclaimed in getnewvnode(). 2170 * Start over if it has (it won't be on the list anymore). 2171 */ 2172 if (vp->v_mount != mp) 2173 goto loop; 2174 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2175 2176 VI_LOCK(vp); 2177 MNT_IUNLOCK(mp); 2178 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td); 2179 if (error) { 2180 MNT_ILOCK(mp); 2181 goto loop; 2182 } 2183 /* 2184 * Skip over a vnodes marked VV_SYSTEM. 2185 */ 2186 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2187 VOP_UNLOCK(vp, 0, td); 2188 MNT_ILOCK(mp); 2189 continue; 2190 } 2191 /* 2192 * If WRITECLOSE is set, flush out unlinked but still open 2193 * files (even if open only for reading) and regular file 2194 * vnodes open for writing. 2195 */ 2196 if (flags & WRITECLOSE) { 2197 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2198 VI_LOCK(vp); 2199 2200 if ((vp->v_type == VNON || 2201 (error == 0 && vattr.va_nlink > 0)) && 2202 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2203 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2204 MNT_ILOCK(mp); 2205 continue; 2206 } 2207 } else 2208 VI_LOCK(vp); 2209 2210 VOP_UNLOCK(vp, 0, td); 2211 2212 /* 2213 * With v_usecount == 0, all we need to do is clear out the 2214 * vnode data structures and we are done. 2215 */ 2216 if (vp->v_usecount == 0) { 2217 vgonel(vp, td); 2218 MNT_ILOCK(mp); 2219 continue; 2220 } 2221 2222 /* 2223 * If FORCECLOSE is set, forcibly close the vnode. For block 2224 * or character devices, revert to an anonymous device. For 2225 * all other files, just kill them. 2226 */ 2227 if (flags & FORCECLOSE) { 2228 if (vp->v_type != VCHR) 2229 vgonel(vp, td); 2230 else 2231 vgonechrl(vp, td); 2232 MNT_ILOCK(mp); 2233 continue; 2234 } 2235 #ifdef DIAGNOSTIC 2236 if (busyprt) 2237 vprint("vflush: busy vnode", vp); 2238 #endif 2239 VI_UNLOCK(vp); 2240 MNT_ILOCK(mp); 2241 busy++; 2242 } 2243 MNT_IUNLOCK(mp); 2244 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2245 /* 2246 * If just the root vnode is busy, and if its refcount 2247 * is equal to `rootrefs', then go ahead and kill it. 2248 */ 2249 VI_LOCK(rootvp); 2250 KASSERT(busy > 0, ("vflush: not busy")); 2251 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 2252 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2253 vgonel(rootvp, td); 2254 busy = 0; 2255 } else 2256 VI_UNLOCK(rootvp); 2257 } 2258 if (busy) 2259 return (EBUSY); 2260 for (; rootrefs > 0; rootrefs--) 2261 vrele(rootvp); 2262 return (0); 2263 } 2264 2265 /* 2266 * This moves a now (likely recyclable) vnode to the end of the 2267 * mountlist. XXX However, it is temporarily disabled until we 2268 * can clean up ffs_sync() and friends, which have loop restart 2269 * conditions which this code causes to operate O(N^2). 2270 */ 2271 static void 2272 vlruvp(struct vnode *vp) 2273 { 2274 #if 0 2275 struct mount *mp; 2276 2277 if ((mp = vp->v_mount) != NULL) { 2278 MNT_ILOCK(mp); 2279 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2280 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2281 MNT_IUNLOCK(mp); 2282 } 2283 #endif 2284 } 2285 2286 static void 2287 vx_lock(struct vnode *vp) 2288 { 2289 2290 ASSERT_VI_LOCKED(vp, "vx_lock"); 2291 2292 /* 2293 * Prevent the vnode from being recycled or brought into use while we 2294 * clean it out. 2295 */ 2296 if (vp->v_iflag & VI_XLOCK) 2297 panic("vclean: deadlock"); 2298 vp->v_iflag |= VI_XLOCK; 2299 vp->v_vxthread = curthread; 2300 } 2301 2302 static void 2303 vx_unlock(struct vnode *vp) 2304 { 2305 ASSERT_VI_LOCKED(vp, "vx_unlock"); 2306 vp->v_iflag &= ~VI_XLOCK; 2307 vp->v_vxthread = NULL; 2308 if (vp->v_iflag & VI_XWANT) { 2309 vp->v_iflag &= ~VI_XWANT; 2310 wakeup(vp); 2311 } 2312 } 2313 2314 /* 2315 * Disassociate the underlying filesystem from a vnode. 2316 */ 2317 static void 2318 vclean(vp, flags, td) 2319 struct vnode *vp; 2320 int flags; 2321 struct thread *td; 2322 { 2323 int active; 2324 2325 ASSERT_VI_LOCKED(vp, "vclean"); 2326 /* 2327 * Check to see if the vnode is in use. If so we have to reference it 2328 * before we clean it out so that its count cannot fall to zero and 2329 * generate a race against ourselves to recycle it. 2330 */ 2331 if ((active = vp->v_usecount)) 2332 v_incr_usecount(vp, 1); 2333 2334 /* 2335 * Even if the count is zero, the VOP_INACTIVE routine may still 2336 * have the object locked while it cleans it out. The VOP_LOCK 2337 * ensures that the VOP_INACTIVE routine is done with its work. 2338 * For active vnodes, it ensures that no other activity can 2339 * occur while the underlying object is being cleaned out. 2340 */ 2341 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2342 2343 /* 2344 * Clean out any buffers associated with the vnode. 2345 * If the flush fails, just toss the buffers. 2346 */ 2347 if (flags & DOCLOSE) { 2348 struct buf *bp; 2349 bp = TAILQ_FIRST(&vp->v_dirtyblkhd); 2350 if (bp != NULL) 2351 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2352 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2353 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2354 } 2355 2356 VOP_DESTROYVOBJECT(vp); 2357 2358 /* 2359 * Any other processes trying to obtain this lock must first 2360 * wait for VXLOCK to clear, then call the new lock operation. 2361 */ 2362 VOP_UNLOCK(vp, 0, td); 2363 2364 /* 2365 * If purging an active vnode, it must be closed and 2366 * deactivated before being reclaimed. Note that the 2367 * VOP_INACTIVE will unlock the vnode. 2368 */ 2369 if (active) { 2370 if (flags & DOCLOSE) 2371 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2372 VI_LOCK(vp); 2373 if ((vp->v_iflag & VI_DOINGINACT) == 0) { 2374 vp->v_iflag |= VI_DOINGINACT; 2375 VI_UNLOCK(vp); 2376 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2377 panic("vclean: cannot relock."); 2378 VOP_INACTIVE(vp, td); 2379 VI_LOCK(vp); 2380 KASSERT(vp->v_iflag & VI_DOINGINACT, 2381 ("vclean: lost VI_DOINGINACT")); 2382 vp->v_iflag &= ~VI_DOINGINACT; 2383 } 2384 VI_UNLOCK(vp); 2385 } 2386 /* 2387 * Reclaim the vnode. 2388 */ 2389 if (VOP_RECLAIM(vp, td)) 2390 panic("vclean: cannot reclaim"); 2391 2392 if (active) { 2393 /* 2394 * Inline copy of vrele() since VOP_INACTIVE 2395 * has already been called. 2396 */ 2397 VI_LOCK(vp); 2398 v_incr_usecount(vp, -1); 2399 if (vp->v_usecount <= 0) { 2400 #ifdef INVARIANTS 2401 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2402 vprint("vclean: bad ref count", vp); 2403 panic("vclean: ref cnt"); 2404 } 2405 #endif 2406 if (VSHOULDFREE(vp)) 2407 vfree(vp); 2408 } 2409 VI_UNLOCK(vp); 2410 } 2411 /* 2412 * Delete from old mount point vnode list. 2413 */ 2414 if (vp->v_mount != NULL) 2415 insmntque(vp, (struct mount *)0); 2416 cache_purge(vp); 2417 VI_LOCK(vp); 2418 if (VSHOULDFREE(vp)) 2419 vfree(vp); 2420 2421 /* 2422 * Done with purge, reset to the standard lock and 2423 * notify sleepers of the grim news. 2424 */ 2425 vp->v_vnlock = &vp->v_lock; 2426 vp->v_op = dead_vnodeop_p; 2427 if (vp->v_pollinfo != NULL) 2428 vn_pollgone(vp); 2429 vp->v_tag = "none"; 2430 } 2431 2432 /* 2433 * Eliminate all activity associated with the requested vnode 2434 * and with all vnodes aliased to the requested vnode. 2435 */ 2436 int 2437 vop_revoke(ap) 2438 struct vop_revoke_args /* { 2439 struct vnode *a_vp; 2440 int a_flags; 2441 } */ *ap; 2442 { 2443 struct vnode *vp, *vq; 2444 dev_t dev; 2445 2446 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2447 vp = ap->a_vp; 2448 KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); 2449 2450 VI_LOCK(vp); 2451 /* 2452 * If a vgone (or vclean) is already in progress, 2453 * wait until it is done and return. 2454 */ 2455 if (vp->v_iflag & VI_XLOCK) { 2456 vp->v_iflag |= VI_XWANT; 2457 msleep(vp, VI_MTX(vp), PINOD | PDROP, 2458 "vop_revokeall", 0); 2459 return (0); 2460 } 2461 VI_UNLOCK(vp); 2462 dev = vp->v_rdev; 2463 for (;;) { 2464 mtx_lock(&spechash_mtx); 2465 vq = SLIST_FIRST(&dev->si_hlist); 2466 mtx_unlock(&spechash_mtx); 2467 if (vq == NULL) 2468 break; 2469 vgone(vq); 2470 } 2471 return (0); 2472 } 2473 2474 /* 2475 * Recycle an unused vnode to the front of the free list. 2476 * Release the passed interlock if the vnode will be recycled. 2477 */ 2478 int 2479 vrecycle(vp, inter_lkp, td) 2480 struct vnode *vp; 2481 struct mtx *inter_lkp; 2482 struct thread *td; 2483 { 2484 2485 VI_LOCK(vp); 2486 if (vp->v_usecount == 0) { 2487 if (inter_lkp) { 2488 mtx_unlock(inter_lkp); 2489 } 2490 vgonel(vp, td); 2491 return (1); 2492 } 2493 VI_UNLOCK(vp); 2494 return (0); 2495 } 2496 2497 /* 2498 * Eliminate all activity associated with a vnode 2499 * in preparation for reuse. 2500 */ 2501 void 2502 vgone(vp) 2503 register struct vnode *vp; 2504 { 2505 struct thread *td = curthread; /* XXX */ 2506 2507 VI_LOCK(vp); 2508 vgonel(vp, td); 2509 } 2510 2511 /* 2512 * Disassociate a character device from the its underlying filesystem and 2513 * attach it to spec. This is for use when the chr device is still active 2514 * and the filesystem is going away. 2515 */ 2516 static void 2517 vgonechrl(struct vnode *vp, struct thread *td) 2518 { 2519 ASSERT_VI_LOCKED(vp, "vgonechrl"); 2520 vx_lock(vp); 2521 /* 2522 * This is a custom version of vclean() which does not tearm down 2523 * the bufs or vm objects held by this vnode. This allows filesystems 2524 * to continue using devices which were discovered via another 2525 * filesystem that has been unmounted. 2526 */ 2527 if (vp->v_usecount != 0) { 2528 v_incr_usecount(vp, 1); 2529 /* 2530 * Ensure that no other activity can occur while the 2531 * underlying object is being cleaned out. 2532 */ 2533 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2534 /* 2535 * Any other processes trying to obtain this lock must first 2536 * wait for VXLOCK to clear, then call the new lock operation. 2537 */ 2538 VOP_UNLOCK(vp, 0, td); 2539 vp->v_vnlock = &vp->v_lock; 2540 vp->v_tag = "orphanchr"; 2541 vp->v_op = spec_vnodeop_p; 2542 if (vp->v_mount != NULL) 2543 insmntque(vp, (struct mount *)0); 2544 cache_purge(vp); 2545 vrele(vp); 2546 VI_LOCK(vp); 2547 } else 2548 vclean(vp, 0, td); 2549 vp->v_op = spec_vnodeop_p; 2550 vx_unlock(vp); 2551 VI_UNLOCK(vp); 2552 } 2553 2554 /* 2555 * vgone, with the vp interlock held. 2556 */ 2557 void 2558 vgonel(vp, td) 2559 struct vnode *vp; 2560 struct thread *td; 2561 { 2562 /* 2563 * If a vgone (or vclean) is already in progress, 2564 * wait until it is done and return. 2565 */ 2566 ASSERT_VI_LOCKED(vp, "vgonel"); 2567 if (vp->v_iflag & VI_XLOCK) { 2568 vp->v_iflag |= VI_XWANT; 2569 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); 2570 return; 2571 } 2572 vx_lock(vp); 2573 2574 /* 2575 * Clean out the filesystem specific data. 2576 */ 2577 vclean(vp, DOCLOSE, td); 2578 VI_UNLOCK(vp); 2579 2580 /* 2581 * If special device, remove it from special device alias list 2582 * if it is on one. 2583 */ 2584 VI_LOCK(vp); 2585 if (vp->v_type == VCHR && vp->v_rdev != NODEV) { 2586 mtx_lock(&spechash_mtx); 2587 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2588 vp->v_rdev->si_usecount -= vp->v_usecount; 2589 mtx_unlock(&spechash_mtx); 2590 dev_rel(vp->v_rdev); 2591 vp->v_rdev = NULL; 2592 } 2593 2594 /* 2595 * If it is on the freelist and not already at the head, 2596 * move it to the head of the list. The test of the 2597 * VDOOMED flag and the reference count of zero is because 2598 * it will be removed from the free list by getnewvnode, 2599 * but will not have its reference count incremented until 2600 * after calling vgone. If the reference count were 2601 * incremented first, vgone would (incorrectly) try to 2602 * close the previous instance of the underlying object. 2603 */ 2604 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2605 mtx_lock(&vnode_free_list_mtx); 2606 if (vp->v_iflag & VI_FREE) { 2607 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2608 } else { 2609 vp->v_iflag |= VI_FREE; 2610 freevnodes++; 2611 } 2612 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2613 mtx_unlock(&vnode_free_list_mtx); 2614 } 2615 2616 vp->v_type = VBAD; 2617 vx_unlock(vp); 2618 VI_UNLOCK(vp); 2619 } 2620 2621 /* 2622 * Lookup a vnode by device number. 2623 */ 2624 int 2625 vfinddev(dev, vpp) 2626 dev_t dev; 2627 struct vnode **vpp; 2628 { 2629 struct vnode *vp; 2630 2631 mtx_lock(&spechash_mtx); 2632 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2633 *vpp = vp; 2634 mtx_unlock(&spechash_mtx); 2635 return (1); 2636 } 2637 mtx_unlock(&spechash_mtx); 2638 return (0); 2639 } 2640 2641 /* 2642 * Calculate the total number of references to a special device. 2643 */ 2644 int 2645 vcount(vp) 2646 struct vnode *vp; 2647 { 2648 int count; 2649 2650 mtx_lock(&spechash_mtx); 2651 count = vp->v_rdev->si_usecount; 2652 mtx_unlock(&spechash_mtx); 2653 return (count); 2654 } 2655 2656 /* 2657 * Same as above, but using the dev_t as argument 2658 */ 2659 int 2660 count_dev(dev) 2661 dev_t dev; 2662 { 2663 int count; 2664 2665 mtx_lock(&spechash_mtx); 2666 count = dev->si_usecount; 2667 mtx_unlock(&spechash_mtx); 2668 return(count); 2669 } 2670 2671 /* 2672 * Print out a description of a vnode. 2673 */ 2674 static char *typename[] = 2675 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2676 2677 void 2678 vprint(label, vp) 2679 char *label; 2680 struct vnode *vp; 2681 { 2682 char buf[96]; 2683 2684 if (label != NULL) 2685 printf("%s: %p: ", label, (void *)vp); 2686 else 2687 printf("%p: ", (void *)vp); 2688 printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", 2689 vp->v_tag, typename[vp->v_type], vp->v_usecount, 2690 vp->v_writecount, vp->v_holdcnt); 2691 buf[0] = '\0'; 2692 if (vp->v_vflag & VV_ROOT) 2693 strcat(buf, "|VV_ROOT"); 2694 if (vp->v_vflag & VV_TEXT) 2695 strcat(buf, "|VV_TEXT"); 2696 if (vp->v_vflag & VV_SYSTEM) 2697 strcat(buf, "|VV_SYSTEM"); 2698 if (vp->v_iflag & VI_XLOCK) 2699 strcat(buf, "|VI_XLOCK"); 2700 if (vp->v_iflag & VI_XWANT) 2701 strcat(buf, "|VI_XWANT"); 2702 if (vp->v_iflag & VI_BWAIT) 2703 strcat(buf, "|VI_BWAIT"); 2704 if (vp->v_iflag & VI_DOOMED) 2705 strcat(buf, "|VI_DOOMED"); 2706 if (vp->v_iflag & VI_FREE) 2707 strcat(buf, "|VI_FREE"); 2708 if (vp->v_vflag & VV_OBJBUF) 2709 strcat(buf, "|VV_OBJBUF"); 2710 if (buf[0] != '\0') 2711 printf(" flags (%s),", &buf[1]); 2712 lockmgr_printinfo(vp->v_vnlock); 2713 printf("\n"); 2714 if (vp->v_data != NULL) 2715 VOP_PRINT(vp); 2716 } 2717 2718 #ifdef DDB 2719 #include <ddb/ddb.h> 2720 /* 2721 * List all of the locked vnodes in the system. 2722 * Called when debugging the kernel. 2723 */ 2724 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2725 { 2726 struct mount *mp, *nmp; 2727 struct vnode *vp; 2728 2729 /* 2730 * Note: because this is DDB, we can't obey the locking semantics 2731 * for these structures, which means we could catch an inconsistent 2732 * state and dereference a nasty pointer. Not much to be done 2733 * about that. 2734 */ 2735 printf("Locked vnodes\n"); 2736 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2737 nmp = TAILQ_NEXT(mp, mnt_list); 2738 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2739 if (VOP_ISLOCKED(vp, NULL)) 2740 vprint(NULL, vp); 2741 } 2742 nmp = TAILQ_NEXT(mp, mnt_list); 2743 } 2744 } 2745 #endif 2746 2747 /* 2748 * Fill in a struct xvfsconf based on a struct vfsconf. 2749 */ 2750 static void 2751 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2752 { 2753 2754 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2755 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2756 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2757 xvfsp->vfc_flags = vfsp->vfc_flags; 2758 /* 2759 * These are unused in userland, we keep them 2760 * to not break binary compatibility. 2761 */ 2762 xvfsp->vfc_vfsops = NULL; 2763 xvfsp->vfc_next = NULL; 2764 } 2765 2766 /* 2767 * Top level filesystem related information gathering. 2768 */ 2769 static int 2770 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2771 { 2772 struct vfsconf *vfsp; 2773 struct xvfsconf *xvfsp; 2774 int cnt, error, i; 2775 2776 cnt = 0; 2777 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 2778 cnt++; 2779 xvfsp = malloc(sizeof(struct xvfsconf) * cnt, M_TEMP, M_WAITOK); 2780 /* 2781 * Handle the race that we will have here when struct vfsconf 2782 * will be locked down by using both cnt and checking vfc_next 2783 * against NULL to determine the end of the loop. The race will 2784 * happen because we will have to unlock before calling malloc(). 2785 * We are protected by Giant for now. 2786 */ 2787 i = 0; 2788 for (vfsp = vfsconf; vfsp != NULL && i < cnt; vfsp = vfsp->vfc_next) { 2789 vfsconf2x(vfsp, xvfsp + i); 2790 i++; 2791 } 2792 error = SYSCTL_OUT(req, xvfsp, sizeof(struct xvfsconf) * i); 2793 free(xvfsp, M_TEMP); 2794 return (error); 2795 } 2796 2797 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2798 "S,xvfsconf", "List of all configured filesystems"); 2799 2800 #ifndef BURN_BRIDGES 2801 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2802 2803 static int 2804 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2805 { 2806 int *name = (int *)arg1 - 1; /* XXX */ 2807 u_int namelen = arg2 + 1; /* XXX */ 2808 struct vfsconf *vfsp; 2809 struct xvfsconf xvfsp; 2810 2811 printf("WARNING: userland calling deprecated sysctl, " 2812 "please rebuild world\n"); 2813 2814 #if 1 || defined(COMPAT_PRELITE2) 2815 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2816 if (namelen == 1) 2817 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2818 #endif 2819 2820 switch (name[1]) { 2821 case VFS_MAXTYPENUM: 2822 if (namelen != 2) 2823 return (ENOTDIR); 2824 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2825 case VFS_CONF: 2826 if (namelen != 3) 2827 return (ENOTDIR); /* overloaded */ 2828 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2829 if (vfsp->vfc_typenum == name[2]) 2830 break; 2831 if (vfsp == NULL) 2832 return (EOPNOTSUPP); 2833 vfsconf2x(vfsp, &xvfsp); 2834 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2835 } 2836 return (EOPNOTSUPP); 2837 } 2838 2839 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 2840 "Generic filesystem"); 2841 2842 #if 1 || defined(COMPAT_PRELITE2) 2843 2844 static int 2845 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2846 { 2847 int error; 2848 struct vfsconf *vfsp; 2849 struct ovfsconf ovfs; 2850 2851 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 2852 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2853 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2854 ovfs.vfc_index = vfsp->vfc_typenum; 2855 ovfs.vfc_refcount = vfsp->vfc_refcount; 2856 ovfs.vfc_flags = vfsp->vfc_flags; 2857 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2858 if (error) 2859 return error; 2860 } 2861 return 0; 2862 } 2863 2864 #endif /* 1 || COMPAT_PRELITE2 */ 2865 #endif /* !BURN_BRIDGES */ 2866 2867 #define KINFO_VNODESLOP 10 2868 #ifdef notyet 2869 /* 2870 * Dump vnode list (via sysctl). 2871 */ 2872 /* ARGSUSED */ 2873 static int 2874 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2875 { 2876 struct xvnode *xvn; 2877 struct thread *td = req->td; 2878 struct mount *mp; 2879 struct vnode *vp; 2880 int error, len, n; 2881 2882 /* 2883 * Stale numvnodes access is not fatal here. 2884 */ 2885 req->lock = 0; 2886 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 2887 if (!req->oldptr) 2888 /* Make an estimate */ 2889 return (SYSCTL_OUT(req, 0, len)); 2890 2891 error = sysctl_wire_old_buffer(req, 0); 2892 if (error != 0) 2893 return (error); 2894 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 2895 n = 0; 2896 mtx_lock(&mountlist_mtx); 2897 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2898 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 2899 continue; 2900 MNT_ILOCK(mp); 2901 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2902 if (n == len) 2903 break; 2904 vref(vp); 2905 xvn[n].xv_size = sizeof *xvn; 2906 xvn[n].xv_vnode = vp; 2907 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 2908 XV_COPY(usecount); 2909 XV_COPY(writecount); 2910 XV_COPY(holdcnt); 2911 XV_COPY(id); 2912 XV_COPY(mount); 2913 XV_COPY(numoutput); 2914 XV_COPY(type); 2915 #undef XV_COPY 2916 xvn[n].xv_flag = vp->v_vflag; 2917 2918 switch (vp->v_type) { 2919 case VREG: 2920 case VDIR: 2921 case VLNK: 2922 xvn[n].xv_dev = vp->v_cachedfs; 2923 xvn[n].xv_ino = vp->v_cachedid; 2924 break; 2925 case VBLK: 2926 case VCHR: 2927 if (vp->v_rdev == NULL) { 2928 vrele(vp); 2929 continue; 2930 } 2931 xvn[n].xv_dev = dev2udev(vp->v_rdev); 2932 break; 2933 case VSOCK: 2934 xvn[n].xv_socket = vp->v_socket; 2935 break; 2936 case VFIFO: 2937 xvn[n].xv_fifo = vp->v_fifoinfo; 2938 break; 2939 case VNON: 2940 case VBAD: 2941 default: 2942 /* shouldn't happen? */ 2943 vrele(vp); 2944 continue; 2945 } 2946 vrele(vp); 2947 ++n; 2948 } 2949 MNT_IUNLOCK(mp); 2950 mtx_lock(&mountlist_mtx); 2951 vfs_unbusy(mp, td); 2952 if (n == len) 2953 break; 2954 } 2955 mtx_unlock(&mountlist_mtx); 2956 2957 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 2958 free(xvn, M_TEMP); 2959 return (error); 2960 } 2961 2962 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2963 0, 0, sysctl_vnode, "S,xvnode", ""); 2964 #endif 2965 2966 /* 2967 * Check to see if a filesystem is mounted on a block device. 2968 */ 2969 int 2970 vfs_mountedon(vp) 2971 struct vnode *vp; 2972 { 2973 2974 if (vp->v_rdev->si_mountpoint != NULL) 2975 return (EBUSY); 2976 return (0); 2977 } 2978 2979 /* 2980 * Unmount all filesystems. The list is traversed in reverse order 2981 * of mounting to avoid dependencies. 2982 */ 2983 void 2984 vfs_unmountall() 2985 { 2986 struct mount *mp; 2987 struct thread *td; 2988 int error; 2989 2990 if (curthread != NULL) 2991 td = curthread; 2992 else 2993 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 2994 /* 2995 * Since this only runs when rebooting, it is not interlocked. 2996 */ 2997 while(!TAILQ_EMPTY(&mountlist)) { 2998 mp = TAILQ_LAST(&mountlist, mntlist); 2999 error = dounmount(mp, MNT_FORCE, td); 3000 if (error) { 3001 TAILQ_REMOVE(&mountlist, mp, mnt_list); 3002 printf("unmount of %s failed (", 3003 mp->mnt_stat.f_mntonname); 3004 if (error == EBUSY) 3005 printf("BUSY)\n"); 3006 else 3007 printf("%d)\n", error); 3008 } else { 3009 /* The unmount has removed mp from the mountlist */ 3010 } 3011 } 3012 } 3013 3014 /* 3015 * perform msync on all vnodes under a mount point 3016 * the mount point must be locked. 3017 */ 3018 void 3019 vfs_msync(struct mount *mp, int flags) 3020 { 3021 struct vnode *vp, *nvp; 3022 struct vm_object *obj; 3023 int tries; 3024 3025 GIANT_REQUIRED; 3026 3027 tries = 5; 3028 MNT_ILOCK(mp); 3029 loop: 3030 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 3031 if (vp->v_mount != mp) { 3032 if (--tries > 0) 3033 goto loop; 3034 break; 3035 } 3036 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 3037 3038 VI_LOCK(vp); 3039 if (vp->v_iflag & VI_XLOCK) { 3040 VI_UNLOCK(vp); 3041 continue; 3042 } 3043 3044 if ((vp->v_iflag & VI_OBJDIRTY) && 3045 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 3046 MNT_IUNLOCK(mp); 3047 if (!vget(vp, 3048 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3049 curthread)) { 3050 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3051 vput(vp); 3052 MNT_ILOCK(mp); 3053 continue; 3054 } 3055 3056 if (VOP_GETVOBJECT(vp, &obj) == 0) { 3057 VM_OBJECT_LOCK(obj); 3058 vm_object_page_clean(obj, 0, 0, 3059 flags == MNT_WAIT ? 3060 OBJPC_SYNC : OBJPC_NOSYNC); 3061 VM_OBJECT_UNLOCK(obj); 3062 } 3063 vput(vp); 3064 } 3065 MNT_ILOCK(mp); 3066 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3067 if (--tries > 0) 3068 goto loop; 3069 break; 3070 } 3071 } else 3072 VI_UNLOCK(vp); 3073 } 3074 MNT_IUNLOCK(mp); 3075 } 3076 3077 /* 3078 * Create the VM object needed for VMIO and mmap support. This 3079 * is done for all VREG files in the system. Some filesystems might 3080 * afford the additional metadata buffering capability of the 3081 * VMIO code by making the device node be VMIO mode also. 3082 * 3083 * vp must be locked when vfs_object_create is called. 3084 */ 3085 int 3086 vfs_object_create(vp, td, cred) 3087 struct vnode *vp; 3088 struct thread *td; 3089 struct ucred *cred; 3090 { 3091 3092 GIANT_REQUIRED; 3093 return (VOP_CREATEVOBJECT(vp, cred, td)); 3094 } 3095 3096 /* 3097 * Mark a vnode as free, putting it up for recycling. 3098 */ 3099 void 3100 vfree(vp) 3101 struct vnode *vp; 3102 { 3103 3104 ASSERT_VI_LOCKED(vp, "vfree"); 3105 mtx_lock(&vnode_free_list_mtx); 3106 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3107 if (vp->v_iflag & VI_AGE) { 3108 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3109 } else { 3110 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3111 } 3112 freevnodes++; 3113 mtx_unlock(&vnode_free_list_mtx); 3114 vp->v_iflag &= ~VI_AGE; 3115 vp->v_iflag |= VI_FREE; 3116 } 3117 3118 /* 3119 * Opposite of vfree() - mark a vnode as in use. 3120 */ 3121 void 3122 vbusy(vp) 3123 struct vnode *vp; 3124 { 3125 3126 ASSERT_VI_LOCKED(vp, "vbusy"); 3127 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3128 3129 mtx_lock(&vnode_free_list_mtx); 3130 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3131 freevnodes--; 3132 mtx_unlock(&vnode_free_list_mtx); 3133 3134 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3135 } 3136 3137 /* 3138 * Initalize per-vnode helper structure to hold poll-related state. 3139 */ 3140 void 3141 v_addpollinfo(struct vnode *vp) 3142 { 3143 3144 vp->v_pollinfo = uma_zalloc(vnodepoll_zone, M_WAITOK); 3145 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3146 } 3147 3148 /* 3149 * Record a process's interest in events which might happen to 3150 * a vnode. Because poll uses the historic select-style interface 3151 * internally, this routine serves as both the ``check for any 3152 * pending events'' and the ``record my interest in future events'' 3153 * functions. (These are done together, while the lock is held, 3154 * to avoid race conditions.) 3155 */ 3156 int 3157 vn_pollrecord(vp, td, events) 3158 struct vnode *vp; 3159 struct thread *td; 3160 short events; 3161 { 3162 3163 if (vp->v_pollinfo == NULL) 3164 v_addpollinfo(vp); 3165 mtx_lock(&vp->v_pollinfo->vpi_lock); 3166 if (vp->v_pollinfo->vpi_revents & events) { 3167 /* 3168 * This leaves events we are not interested 3169 * in available for the other process which 3170 * which presumably had requested them 3171 * (otherwise they would never have been 3172 * recorded). 3173 */ 3174 events &= vp->v_pollinfo->vpi_revents; 3175 vp->v_pollinfo->vpi_revents &= ~events; 3176 3177 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3178 return events; 3179 } 3180 vp->v_pollinfo->vpi_events |= events; 3181 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3182 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3183 return 0; 3184 } 3185 3186 /* 3187 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3188 * it is possible for us to miss an event due to race conditions, but 3189 * that condition is expected to be rare, so for the moment it is the 3190 * preferred interface. 3191 */ 3192 void 3193 vn_pollevent(vp, events) 3194 struct vnode *vp; 3195 short events; 3196 { 3197 3198 if (vp->v_pollinfo == NULL) 3199 v_addpollinfo(vp); 3200 mtx_lock(&vp->v_pollinfo->vpi_lock); 3201 if (vp->v_pollinfo->vpi_events & events) { 3202 /* 3203 * We clear vpi_events so that we don't 3204 * call selwakeup() twice if two events are 3205 * posted before the polling process(es) is 3206 * awakened. This also ensures that we take at 3207 * most one selwakeup() if the polling process 3208 * is no longer interested. However, it does 3209 * mean that only one event can be noticed at 3210 * a time. (Perhaps we should only clear those 3211 * event bits which we note?) XXX 3212 */ 3213 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3214 vp->v_pollinfo->vpi_revents |= events; 3215 selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); 3216 } 3217 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3218 } 3219 3220 /* 3221 * Wake up anyone polling on vp because it is being revoked. 3222 * This depends on dead_poll() returning POLLHUP for correct 3223 * behavior. 3224 */ 3225 void 3226 vn_pollgone(vp) 3227 struct vnode *vp; 3228 { 3229 3230 mtx_lock(&vp->v_pollinfo->vpi_lock); 3231 VN_KNOTE(vp, NOTE_REVOKE); 3232 if (vp->v_pollinfo->vpi_events) { 3233 vp->v_pollinfo->vpi_events = 0; 3234 selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); 3235 } 3236 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3237 } 3238 3239 3240 3241 /* 3242 * Routine to create and manage a filesystem syncer vnode. 3243 */ 3244 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3245 static int sync_fsync(struct vop_fsync_args *); 3246 static int sync_inactive(struct vop_inactive_args *); 3247 static int sync_reclaim(struct vop_reclaim_args *); 3248 3249 static vop_t **sync_vnodeop_p; 3250 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3251 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3252 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3253 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3254 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3255 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3256 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3257 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3258 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3259 { NULL, NULL } 3260 }; 3261 static struct vnodeopv_desc sync_vnodeop_opv_desc = 3262 { &sync_vnodeop_p, sync_vnodeop_entries }; 3263 3264 VNODEOP_SET(sync_vnodeop_opv_desc); 3265 3266 /* 3267 * Create a new filesystem syncer vnode for the specified mount point. 3268 */ 3269 int 3270 vfs_allocate_syncvnode(mp) 3271 struct mount *mp; 3272 { 3273 struct vnode *vp; 3274 static long start, incr, next; 3275 int error; 3276 3277 /* Allocate a new vnode */ 3278 if ((error = getnewvnode("syncer", mp, sync_vnodeop_p, &vp)) != 0) { 3279 mp->mnt_syncer = NULL; 3280 return (error); 3281 } 3282 vp->v_type = VNON; 3283 /* 3284 * Place the vnode onto the syncer worklist. We attempt to 3285 * scatter them about on the list so that they will go off 3286 * at evenly distributed times even if all the filesystems 3287 * are mounted at once. 3288 */ 3289 next += incr; 3290 if (next == 0 || next > syncer_maxdelay) { 3291 start /= 2; 3292 incr /= 2; 3293 if (start == 0) { 3294 start = syncer_maxdelay / 2; 3295 incr = syncer_maxdelay; 3296 } 3297 next = start; 3298 } 3299 VI_LOCK(vp); 3300 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 3301 VI_UNLOCK(vp); 3302 mp->mnt_syncer = vp; 3303 return (0); 3304 } 3305 3306 /* 3307 * Do a lazy sync of the filesystem. 3308 */ 3309 static int 3310 sync_fsync(ap) 3311 struct vop_fsync_args /* { 3312 struct vnode *a_vp; 3313 struct ucred *a_cred; 3314 int a_waitfor; 3315 struct thread *a_td; 3316 } */ *ap; 3317 { 3318 struct vnode *syncvp = ap->a_vp; 3319 struct mount *mp = syncvp->v_mount; 3320 struct thread *td = ap->a_td; 3321 int error, asyncflag; 3322 3323 /* 3324 * We only need to do something if this is a lazy evaluation. 3325 */ 3326 if (ap->a_waitfor != MNT_LAZY) 3327 return (0); 3328 3329 /* 3330 * Move ourselves to the back of the sync list. 3331 */ 3332 VI_LOCK(syncvp); 3333 vn_syncer_add_to_worklist(syncvp, syncdelay); 3334 VI_UNLOCK(syncvp); 3335 3336 /* 3337 * Walk the list of vnodes pushing all that are dirty and 3338 * not already on the sync list. 3339 */ 3340 mtx_lock(&mountlist_mtx); 3341 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3342 mtx_unlock(&mountlist_mtx); 3343 return (0); 3344 } 3345 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3346 vfs_unbusy(mp, td); 3347 return (0); 3348 } 3349 asyncflag = mp->mnt_flag & MNT_ASYNC; 3350 mp->mnt_flag &= ~MNT_ASYNC; 3351 vfs_msync(mp, MNT_NOWAIT); 3352 error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3353 if (asyncflag) 3354 mp->mnt_flag |= MNT_ASYNC; 3355 vn_finished_write(mp); 3356 vfs_unbusy(mp, td); 3357 return (error); 3358 } 3359 3360 /* 3361 * The syncer vnode is no referenced. 3362 */ 3363 static int 3364 sync_inactive(ap) 3365 struct vop_inactive_args /* { 3366 struct vnode *a_vp; 3367 struct thread *a_td; 3368 } */ *ap; 3369 { 3370 3371 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3372 vgone(ap->a_vp); 3373 return (0); 3374 } 3375 3376 /* 3377 * The syncer vnode is no longer needed and is being decommissioned. 3378 * 3379 * Modifications to the worklist must be protected by sync_mtx. 3380 */ 3381 static int 3382 sync_reclaim(ap) 3383 struct vop_reclaim_args /* { 3384 struct vnode *a_vp; 3385 } */ *ap; 3386 { 3387 struct vnode *vp = ap->a_vp; 3388 3389 VI_LOCK(vp); 3390 vp->v_mount->mnt_syncer = NULL; 3391 if (vp->v_iflag & VI_ONWORKLST) { 3392 mtx_lock(&sync_mtx); 3393 LIST_REMOVE(vp, v_synclist); 3394 mtx_unlock(&sync_mtx); 3395 vp->v_iflag &= ~VI_ONWORKLST; 3396 } 3397 VI_UNLOCK(vp); 3398 3399 return (0); 3400 } 3401 3402 /* 3403 * extract the dev_t from a VCHR 3404 */ 3405 dev_t 3406 vn_todev(vp) 3407 struct vnode *vp; 3408 { 3409 3410 if (vp->v_type != VCHR) 3411 return (NODEV); 3412 return (vp->v_rdev); 3413 } 3414 3415 /* 3416 * Check if vnode represents a disk device 3417 */ 3418 int 3419 vn_isdisk(vp, errp) 3420 struct vnode *vp; 3421 int *errp; 3422 { 3423 int error; 3424 3425 error = 0; 3426 if (vp->v_type != VCHR) 3427 error = ENOTBLK; 3428 else if (vp->v_rdev == NULL) 3429 error = ENXIO; 3430 else if (!(devsw(vp->v_rdev)->d_flags & D_DISK)) 3431 error = ENOTBLK; 3432 if (errp != NULL) 3433 *errp = error; 3434 return (error == 0); 3435 } 3436 3437 /* 3438 * Free data allocated by namei(); see namei(9) for details. 3439 */ 3440 void 3441 NDFREE(ndp, flags) 3442 struct nameidata *ndp; 3443 const u_int flags; 3444 { 3445 3446 if (!(flags & NDF_NO_FREE_PNBUF) && 3447 (ndp->ni_cnd.cn_flags & HASBUF)) { 3448 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3449 ndp->ni_cnd.cn_flags &= ~HASBUF; 3450 } 3451 if (!(flags & NDF_NO_DVP_UNLOCK) && 3452 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3453 ndp->ni_dvp != ndp->ni_vp) 3454 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3455 if (!(flags & NDF_NO_DVP_RELE) && 3456 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3457 vrele(ndp->ni_dvp); 3458 ndp->ni_dvp = NULL; 3459 } 3460 if (!(flags & NDF_NO_VP_UNLOCK) && 3461 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3462 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3463 if (!(flags & NDF_NO_VP_RELE) && 3464 ndp->ni_vp) { 3465 vrele(ndp->ni_vp); 3466 ndp->ni_vp = NULL; 3467 } 3468 if (!(flags & NDF_NO_STARTDIR_RELE) && 3469 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3470 vrele(ndp->ni_startdir); 3471 ndp->ni_startdir = NULL; 3472 } 3473 } 3474 3475 /* 3476 * Common filesystem object access control check routine. Accepts a 3477 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3478 * and optional call-by-reference privused argument allowing vaccess() 3479 * to indicate to the caller whether privilege was used to satisfy the 3480 * request (obsoleted). Returns 0 on success, or an errno on failure. 3481 */ 3482 int 3483 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3484 enum vtype type; 3485 mode_t file_mode; 3486 uid_t file_uid; 3487 gid_t file_gid; 3488 mode_t acc_mode; 3489 struct ucred *cred; 3490 int *privused; 3491 { 3492 mode_t dac_granted; 3493 #ifdef CAPABILITIES 3494 mode_t cap_granted; 3495 #endif 3496 3497 /* 3498 * Look for a normal, non-privileged way to access the file/directory 3499 * as requested. If it exists, go with that. 3500 */ 3501 3502 if (privused != NULL) 3503 *privused = 0; 3504 3505 dac_granted = 0; 3506 3507 /* Check the owner. */ 3508 if (cred->cr_uid == file_uid) { 3509 dac_granted |= VADMIN; 3510 if (file_mode & S_IXUSR) 3511 dac_granted |= VEXEC; 3512 if (file_mode & S_IRUSR) 3513 dac_granted |= VREAD; 3514 if (file_mode & S_IWUSR) 3515 dac_granted |= (VWRITE | VAPPEND); 3516 3517 if ((acc_mode & dac_granted) == acc_mode) 3518 return (0); 3519 3520 goto privcheck; 3521 } 3522 3523 /* Otherwise, check the groups (first match) */ 3524 if (groupmember(file_gid, cred)) { 3525 if (file_mode & S_IXGRP) 3526 dac_granted |= VEXEC; 3527 if (file_mode & S_IRGRP) 3528 dac_granted |= VREAD; 3529 if (file_mode & S_IWGRP) 3530 dac_granted |= (VWRITE | VAPPEND); 3531 3532 if ((acc_mode & dac_granted) == acc_mode) 3533 return (0); 3534 3535 goto privcheck; 3536 } 3537 3538 /* Otherwise, check everyone else. */ 3539 if (file_mode & S_IXOTH) 3540 dac_granted |= VEXEC; 3541 if (file_mode & S_IROTH) 3542 dac_granted |= VREAD; 3543 if (file_mode & S_IWOTH) 3544 dac_granted |= (VWRITE | VAPPEND); 3545 if ((acc_mode & dac_granted) == acc_mode) 3546 return (0); 3547 3548 privcheck: 3549 if (!suser_cred(cred, PRISON_ROOT)) { 3550 /* XXX audit: privilege used */ 3551 if (privused != NULL) 3552 *privused = 1; 3553 return (0); 3554 } 3555 3556 #ifdef CAPABILITIES 3557 /* 3558 * Build a capability mask to determine if the set of capabilities 3559 * satisfies the requirements when combined with the granted mask 3560 * from above. 3561 * For each capability, if the capability is required, bitwise 3562 * or the request type onto the cap_granted mask. 3563 */ 3564 cap_granted = 0; 3565 3566 if (type == VDIR) { 3567 /* 3568 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3569 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3570 */ 3571 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3572 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3573 cap_granted |= VEXEC; 3574 } else { 3575 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3576 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3577 cap_granted |= VEXEC; 3578 } 3579 3580 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3581 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3582 cap_granted |= VREAD; 3583 3584 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3585 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3586 cap_granted |= (VWRITE | VAPPEND); 3587 3588 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3589 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3590 cap_granted |= VADMIN; 3591 3592 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3593 /* XXX audit: privilege used */ 3594 if (privused != NULL) 3595 *privused = 1; 3596 return (0); 3597 } 3598 #endif 3599 3600 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3601 } 3602 3603 /* 3604 * Credential check based on process requesting service, and per-attribute 3605 * permissions. 3606 */ 3607 int 3608 extattr_check_cred(struct vnode *vp, int attrnamespace, 3609 struct ucred *cred, struct thread *td, int access) 3610 { 3611 3612 /* 3613 * Kernel-invoked always succeeds. 3614 */ 3615 if (cred == NOCRED) 3616 return (0); 3617 3618 /* 3619 * Do not allow privileged processes in jail to directly 3620 * manipulate system attributes. 3621 * 3622 * XXX What capability should apply here? 3623 * Probably CAP_SYS_SETFFLAG. 3624 */ 3625 switch (attrnamespace) { 3626 case EXTATTR_NAMESPACE_SYSTEM: 3627 /* Potentially should be: return (EPERM); */ 3628 return (suser_cred(cred, 0)); 3629 case EXTATTR_NAMESPACE_USER: 3630 return (VOP_ACCESS(vp, access, cred, td)); 3631 default: 3632 return (EPERM); 3633 } 3634 } 3635 3636 #ifdef DEBUG_VFS_LOCKS 3637 /* 3638 * This only exists to supress warnings from unlocked specfs accesses. It is 3639 * no longer ok to have an unlocked VFS. 3640 */ 3641 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 3642 3643 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3644 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3645 int vfs_badlock_print = 1; /* Print lock violations. */ 3646 3647 static void 3648 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3649 { 3650 3651 if (vfs_badlock_print) 3652 printf("%s: %p %s\n", str, (void *)vp, msg); 3653 if (vfs_badlock_ddb) 3654 Debugger("lock violation"); 3655 } 3656 3657 void 3658 assert_vi_locked(struct vnode *vp, const char *str) 3659 { 3660 3661 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3662 vfs_badlock("interlock is not locked but should be", str, vp); 3663 } 3664 3665 void 3666 assert_vi_unlocked(struct vnode *vp, const char *str) 3667 { 3668 3669 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3670 vfs_badlock("interlock is locked but should not be", str, vp); 3671 } 3672 3673 void 3674 assert_vop_locked(struct vnode *vp, const char *str) 3675 { 3676 3677 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0) 3678 vfs_badlock("is not locked but should be", str, vp); 3679 } 3680 3681 void 3682 assert_vop_unlocked(struct vnode *vp, const char *str) 3683 { 3684 3685 if (vp && !IGNORE_LOCK(vp) && 3686 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 3687 vfs_badlock("is locked but should not be", str, vp); 3688 } 3689 3690 #if 0 3691 void 3692 assert_vop_elocked(struct vnode *vp, const char *str) 3693 { 3694 3695 if (vp && !IGNORE_LOCK(vp) && 3696 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 3697 vfs_badlock("is not exclusive locked but should be", str, vp); 3698 } 3699 3700 void 3701 assert_vop_elocked_other(struct vnode *vp, const char *str) 3702 { 3703 3704 if (vp && !IGNORE_LOCK(vp) && 3705 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 3706 vfs_badlock("is not exclusive locked by another thread", 3707 str, vp); 3708 } 3709 3710 void 3711 assert_vop_slocked(struct vnode *vp, const char *str) 3712 { 3713 3714 if (vp && !IGNORE_LOCK(vp) && 3715 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 3716 vfs_badlock("is not locked shared but should be", str, vp); 3717 } 3718 #endif /* 0 */ 3719 3720 void 3721 vop_rename_pre(void *ap) 3722 { 3723 struct vop_rename_args *a = ap; 3724 3725 if (a->a_tvp) 3726 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3727 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3728 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3729 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3730 3731 /* Check the source (from). */ 3732 if (a->a_tdvp != a->a_fdvp) 3733 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3734 if (a->a_tvp != a->a_fvp) 3735 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked"); 3736 3737 /* Check the target. */ 3738 if (a->a_tvp) 3739 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3740 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3741 } 3742 3743 void 3744 vop_strategy_pre(void *ap) 3745 { 3746 struct vop_strategy_args *a; 3747 struct buf *bp; 3748 3749 a = ap; 3750 bp = a->a_bp; 3751 3752 /* 3753 * Cluster ops lock their component buffers but not the IO container. 3754 */ 3755 if ((bp->b_flags & B_CLUSTER) != 0) 3756 return; 3757 3758 if (BUF_REFCNT(bp) < 1) { 3759 if (vfs_badlock_print) 3760 printf( 3761 "VOP_STRATEGY: bp is not locked but should be\n"); 3762 if (vfs_badlock_ddb) 3763 Debugger("lock violation"); 3764 } 3765 } 3766 3767 void 3768 vop_lookup_pre(void *ap) 3769 { 3770 struct vop_lookup_args *a; 3771 struct vnode *dvp; 3772 3773 a = ap; 3774 dvp = a->a_dvp; 3775 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3776 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3777 } 3778 3779 void 3780 vop_lookup_post(void *ap, int rc) 3781 { 3782 struct vop_lookup_args *a; 3783 struct componentname *cnp; 3784 struct vnode *dvp; 3785 struct vnode *vp; 3786 int flags; 3787 3788 a = ap; 3789 dvp = a->a_dvp; 3790 cnp = a->a_cnp; 3791 vp = *(a->a_vpp); 3792 flags = cnp->cn_flags; 3793 3794 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3795 3796 /* 3797 * If this is the last path component for this lookup and LOCKPARENT 3798 * is set, OR if there is an error the directory has to be locked. 3799 */ 3800 if ((flags & LOCKPARENT) && (flags & ISLASTCN)) 3801 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); 3802 else if (rc != 0) 3803 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); 3804 else if (dvp != vp) 3805 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); 3806 if (flags & PDIRUNLOCK) 3807 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); 3808 } 3809 3810 void 3811 vop_lock_pre(void *ap) 3812 { 3813 struct vop_lock_args *a = ap; 3814 3815 if ((a->a_flags & LK_INTERLOCK) == 0) 3816 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3817 else 3818 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3819 } 3820 3821 void 3822 vop_lock_post(void *ap, int rc) 3823 { 3824 struct vop_lock_args *a = ap; 3825 3826 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3827 if (rc == 0) 3828 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3829 } 3830 3831 void 3832 vop_unlock_pre(void *ap) 3833 { 3834 struct vop_unlock_args *a = ap; 3835 3836 if (a->a_flags & LK_INTERLOCK) 3837 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 3838 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 3839 } 3840 3841 void 3842 vop_unlock_post(void *ap, int rc) 3843 { 3844 struct vop_unlock_args *a = ap; 3845 3846 if (a->a_flags & LK_INTERLOCK) 3847 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 3848 } 3849 #endif /* DEBUG_VFS_LOCKS */ 3850