1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 37 */ 38 39 /* 40 * External virtual filesystem routines 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_ddb.h" 47 #include "opt_watchdog.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/bio.h> 52 #include <sys/buf.h> 53 #include <sys/capsicum.h> 54 #include <sys/condvar.h> 55 #include <sys/conf.h> 56 #include <sys/counter.h> 57 #include <sys/dirent.h> 58 #include <sys/event.h> 59 #include <sys/eventhandler.h> 60 #include <sys/extattr.h> 61 #include <sys/file.h> 62 #include <sys/fcntl.h> 63 #include <sys/jail.h> 64 #include <sys/kdb.h> 65 #include <sys/kernel.h> 66 #include <sys/kthread.h> 67 #include <sys/ktr.h> 68 #include <sys/lockf.h> 69 #include <sys/malloc.h> 70 #include <sys/mount.h> 71 #include <sys/namei.h> 72 #include <sys/pctrie.h> 73 #include <sys/priv.h> 74 #include <sys/reboot.h> 75 #include <sys/refcount.h> 76 #include <sys/rwlock.h> 77 #include <sys/sched.h> 78 #include <sys/sleepqueue.h> 79 #include <sys/smp.h> 80 #include <sys/stat.h> 81 #include <sys/sysctl.h> 82 #include <sys/syslog.h> 83 #include <sys/vmmeter.h> 84 #include <sys/vnode.h> 85 #include <sys/watchdog.h> 86 87 #include <machine/stdarg.h> 88 89 #include <security/mac/mac_framework.h> 90 91 #include <vm/vm.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_extern.h> 94 #include <vm/pmap.h> 95 #include <vm/vm_map.h> 96 #include <vm/vm_page.h> 97 #include <vm/vm_kern.h> 98 #include <vm/uma.h> 99 100 #ifdef DDB 101 #include <ddb/ddb.h> 102 #endif 103 104 static void delmntque(struct vnode *vp); 105 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 106 int slpflag, int slptimeo); 107 static void syncer_shutdown(void *arg, int howto); 108 static int vtryrecycle(struct vnode *vp); 109 static void v_init_counters(struct vnode *); 110 static void v_incr_devcount(struct vnode *); 111 static void v_decr_devcount(struct vnode *); 112 static void vgonel(struct vnode *); 113 static void vfs_knllock(void *arg); 114 static void vfs_knlunlock(void *arg); 115 static void vfs_knl_assert_locked(void *arg); 116 static void vfs_knl_assert_unlocked(void *arg); 117 static void destroy_vpollinfo(struct vpollinfo *vi); 118 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 119 daddr_t startlbn, daddr_t endlbn); 120 static void vnlru_recalc(void); 121 122 /* 123 * These fences are intended for cases where some synchronization is 124 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 125 * and v_usecount) updates. Access to v_iflags is generally synchronized 126 * by the interlock, but we have some internal assertions that check vnode 127 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 128 * for now. 129 */ 130 #ifdef INVARIANTS 131 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 132 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 133 #else 134 #define VNODE_REFCOUNT_FENCE_ACQ() 135 #define VNODE_REFCOUNT_FENCE_REL() 136 #endif 137 138 /* 139 * Number of vnodes in existence. Increased whenever getnewvnode() 140 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode. 141 */ 142 static u_long __exclusive_cache_line numvnodes; 143 144 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 145 "Number of vnodes in existence"); 146 147 static counter_u64_t vnodes_created; 148 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 149 "Number of vnodes created by getnewvnode"); 150 151 /* 152 * Conversion tables for conversion from vnode types to inode formats 153 * and back. 154 */ 155 enum vtype iftovt_tab[16] = { 156 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 157 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 158 }; 159 int vttoif_tab[10] = { 160 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 161 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 162 }; 163 164 /* 165 * List of allocates vnodes in the system. 166 */ 167 static TAILQ_HEAD(freelst, vnode) vnode_list; 168 static struct vnode *vnode_list_free_marker; 169 static struct vnode *vnode_list_reclaim_marker; 170 171 /* 172 * "Free" vnode target. Free vnodes are rarely completely free, but are 173 * just ones that are cheap to recycle. Usually they are for files which 174 * have been stat'd but not read; these usually have inode and namecache 175 * data attached to them. This target is the preferred minimum size of a 176 * sub-cache consisting mostly of such files. The system balances the size 177 * of this sub-cache with its complement to try to prevent either from 178 * thrashing while the other is relatively inactive. The targets express 179 * a preference for the best balance. 180 * 181 * "Above" this target there are 2 further targets (watermarks) related 182 * to recyling of free vnodes. In the best-operating case, the cache is 183 * exactly full, the free list has size between vlowat and vhiwat above the 184 * free target, and recycling from it and normal use maintains this state. 185 * Sometimes the free list is below vlowat or even empty, but this state 186 * is even better for immediate use provided the cache is not full. 187 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 188 * ones) to reach one of these states. The watermarks are currently hard- 189 * coded as 4% and 9% of the available space higher. These and the default 190 * of 25% for wantfreevnodes are too large if the memory size is large. 191 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 192 * whenever vnlru_proc() becomes active. 193 */ 194 static long wantfreevnodes; 195 static long __exclusive_cache_line freevnodes; 196 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 197 &freevnodes, 0, "Number of \"free\" vnodes"); 198 static long freevnodes_old; 199 200 static counter_u64_t recycles_count; 201 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 202 "Number of vnodes recycled to meet vnode cache targets"); 203 204 static counter_u64_t recycles_free_count; 205 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD, &recycles_free_count, 206 "Number of free vnodes recycled to meet vnode cache targets"); 207 208 /* 209 * Various variables used for debugging the new implementation of 210 * reassignbuf(). 211 * XXX these are probably of (very) limited utility now. 212 */ 213 static int reassignbufcalls; 214 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW | CTLFLAG_STATS, 215 &reassignbufcalls, 0, "Number of calls to reassignbuf"); 216 217 static counter_u64_t deferred_inact; 218 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD, &deferred_inact, 219 "Number of times inactive processing was deferred"); 220 221 /* To keep more than one thread at a time from running vfs_getnewfsid */ 222 static struct mtx mntid_mtx; 223 224 /* 225 * Lock for any access to the following: 226 * vnode_list 227 * numvnodes 228 * freevnodes 229 */ 230 static struct mtx __exclusive_cache_line vnode_list_mtx; 231 232 /* Publicly exported FS */ 233 struct nfs_public nfs_pub; 234 235 static uma_zone_t buf_trie_zone; 236 237 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 238 static uma_zone_t vnode_zone; 239 static uma_zone_t vnodepoll_zone; 240 241 /* 242 * The workitem queue. 243 * 244 * It is useful to delay writes of file data and filesystem metadata 245 * for tens of seconds so that quickly created and deleted files need 246 * not waste disk bandwidth being created and removed. To realize this, 247 * we append vnodes to a "workitem" queue. When running with a soft 248 * updates implementation, most pending metadata dependencies should 249 * not wait for more than a few seconds. Thus, mounted on block devices 250 * are delayed only about a half the time that file data is delayed. 251 * Similarly, directory updates are more critical, so are only delayed 252 * about a third the time that file data is delayed. Thus, there are 253 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 254 * one each second (driven off the filesystem syncer process). The 255 * syncer_delayno variable indicates the next queue that is to be processed. 256 * Items that need to be processed soon are placed in this queue: 257 * 258 * syncer_workitem_pending[syncer_delayno] 259 * 260 * A delay of fifteen seconds is done by placing the request fifteen 261 * entries later in the queue: 262 * 263 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 264 * 265 */ 266 static int syncer_delayno; 267 static long syncer_mask; 268 LIST_HEAD(synclist, bufobj); 269 static struct synclist *syncer_workitem_pending; 270 /* 271 * The sync_mtx protects: 272 * bo->bo_synclist 273 * sync_vnode_count 274 * syncer_delayno 275 * syncer_state 276 * syncer_workitem_pending 277 * syncer_worklist_len 278 * rushjob 279 */ 280 static struct mtx sync_mtx; 281 static struct cv sync_wakeup; 282 283 #define SYNCER_MAXDELAY 32 284 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 285 static int syncdelay = 30; /* max time to delay syncing data */ 286 static int filedelay = 30; /* time to delay syncing files */ 287 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 288 "Time to delay syncing files (in seconds)"); 289 static int dirdelay = 29; /* time to delay syncing directories */ 290 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 291 "Time to delay syncing directories (in seconds)"); 292 static int metadelay = 28; /* time to delay syncing metadata */ 293 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 294 "Time to delay syncing metadata (in seconds)"); 295 static int rushjob; /* number of slots to run ASAP */ 296 static int stat_rush_requests; /* number of times I/O speeded up */ 297 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 298 "Number of times I/O speeded up (rush requests)"); 299 300 #define VDBATCH_SIZE 8 301 struct vdbatch { 302 u_int index; 303 long freevnodes; 304 struct mtx lock; 305 struct vnode *tab[VDBATCH_SIZE]; 306 }; 307 DPCPU_DEFINE_STATIC(struct vdbatch, vd); 308 309 static void vdbatch_dequeue(struct vnode *vp); 310 311 /* 312 * When shutting down the syncer, run it at four times normal speed. 313 */ 314 #define SYNCER_SHUTDOWN_SPEEDUP 4 315 static int sync_vnode_count; 316 static int syncer_worklist_len; 317 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 318 syncer_state; 319 320 /* Target for maximum number of vnodes. */ 321 u_long desiredvnodes; 322 static u_long gapvnodes; /* gap between wanted and desired */ 323 static u_long vhiwat; /* enough extras after expansion */ 324 static u_long vlowat; /* minimal extras before expansion */ 325 static u_long vstir; /* nonzero to stir non-free vnodes */ 326 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 327 328 static u_long vnlru_read_freevnodes(void); 329 330 /* 331 * Note that no attempt is made to sanitize these parameters. 332 */ 333 static int 334 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS) 335 { 336 u_long val; 337 int error; 338 339 val = desiredvnodes; 340 error = sysctl_handle_long(oidp, &val, 0, req); 341 if (error != 0 || req->newptr == NULL) 342 return (error); 343 344 if (val == desiredvnodes) 345 return (0); 346 mtx_lock(&vnode_list_mtx); 347 desiredvnodes = val; 348 wantfreevnodes = desiredvnodes / 4; 349 vnlru_recalc(); 350 mtx_unlock(&vnode_list_mtx); 351 /* 352 * XXX There is no protection against multiple threads changing 353 * desiredvnodes at the same time. Locking above only helps vnlru and 354 * getnewvnode. 355 */ 356 vfs_hash_changesize(desiredvnodes); 357 cache_changesize(desiredvnodes); 358 return (0); 359 } 360 361 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 362 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes, 363 "LU", "Target for maximum number of vnodes"); 364 365 static int 366 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS) 367 { 368 u_long val; 369 int error; 370 371 val = wantfreevnodes; 372 error = sysctl_handle_long(oidp, &val, 0, req); 373 if (error != 0 || req->newptr == NULL) 374 return (error); 375 376 if (val == wantfreevnodes) 377 return (0); 378 mtx_lock(&vnode_list_mtx); 379 wantfreevnodes = val; 380 vnlru_recalc(); 381 mtx_unlock(&vnode_list_mtx); 382 return (0); 383 } 384 385 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes, 386 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes, 387 "LU", "Target for minimum number of \"free\" vnodes"); 388 389 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 390 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 391 static int vnlru_nowhere; 392 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 393 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 394 395 static int 396 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 397 { 398 struct vnode *vp; 399 struct nameidata nd; 400 char *buf; 401 unsigned long ndflags; 402 int error; 403 404 if (req->newptr == NULL) 405 return (EINVAL); 406 if (req->newlen >= PATH_MAX) 407 return (E2BIG); 408 409 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK); 410 error = SYSCTL_IN(req, buf, req->newlen); 411 if (error != 0) 412 goto out; 413 414 buf[req->newlen] = '\0'; 415 416 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME; 417 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); 418 if ((error = namei(&nd)) != 0) 419 goto out; 420 vp = nd.ni_vp; 421 422 if (VN_IS_DOOMED(vp)) { 423 /* 424 * This vnode is being recycled. Return != 0 to let the caller 425 * know that the sysctl had no effect. Return EAGAIN because a 426 * subsequent call will likely succeed (since namei will create 427 * a new vnode if necessary) 428 */ 429 error = EAGAIN; 430 goto putvnode; 431 } 432 433 counter_u64_add(recycles_count, 1); 434 vgone(vp); 435 putvnode: 436 NDFREE(&nd, 0); 437 out: 438 free(buf, M_TEMP); 439 return (error); 440 } 441 442 static int 443 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 444 { 445 struct thread *td = curthread; 446 struct vnode *vp; 447 struct file *fp; 448 int error; 449 int fd; 450 451 if (req->newptr == NULL) 452 return (EBADF); 453 454 error = sysctl_handle_int(oidp, &fd, 0, req); 455 if (error != 0) 456 return (error); 457 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 458 if (error != 0) 459 return (error); 460 vp = fp->f_vnode; 461 462 error = vn_lock(vp, LK_EXCLUSIVE); 463 if (error != 0) 464 goto drop; 465 466 counter_u64_add(recycles_count, 1); 467 vgone(vp); 468 VOP_UNLOCK(vp); 469 drop: 470 fdrop(fp, td); 471 return (error); 472 } 473 474 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 475 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 476 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 477 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 478 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 479 sysctl_ftry_reclaim_vnode, "I", 480 "Try to reclaim a vnode by its file descriptor"); 481 482 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 483 static int vnsz2log; 484 485 /* 486 * Support for the bufobj clean & dirty pctrie. 487 */ 488 static void * 489 buf_trie_alloc(struct pctrie *ptree) 490 { 491 492 return uma_zalloc(buf_trie_zone, M_NOWAIT); 493 } 494 495 static void 496 buf_trie_free(struct pctrie *ptree, void *node) 497 { 498 499 uma_zfree(buf_trie_zone, node); 500 } 501 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 502 503 /* 504 * Initialize the vnode management data structures. 505 * 506 * Reevaluate the following cap on the number of vnodes after the physical 507 * memory size exceeds 512GB. In the limit, as the physical memory size 508 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 509 */ 510 #ifndef MAXVNODES_MAX 511 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */ 512 #endif 513 514 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 515 516 static struct vnode * 517 vn_alloc_marker(struct mount *mp) 518 { 519 struct vnode *vp; 520 521 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 522 vp->v_type = VMARKER; 523 vp->v_mount = mp; 524 525 return (vp); 526 } 527 528 static void 529 vn_free_marker(struct vnode *vp) 530 { 531 532 MPASS(vp->v_type == VMARKER); 533 free(vp, M_VNODE_MARKER); 534 } 535 536 /* 537 * Initialize a vnode as it first enters the zone. 538 */ 539 static int 540 vnode_init(void *mem, int size, int flags) 541 { 542 struct vnode *vp; 543 544 vp = mem; 545 bzero(vp, size); 546 /* 547 * Setup locks. 548 */ 549 vp->v_vnlock = &vp->v_lock; 550 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 551 /* 552 * By default, don't allow shared locks unless filesystems opt-in. 553 */ 554 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 555 LK_NOSHARE | LK_IS_VNODE); 556 /* 557 * Initialize bufobj. 558 */ 559 bufobj_init(&vp->v_bufobj, vp); 560 /* 561 * Initialize namecache. 562 */ 563 LIST_INIT(&vp->v_cache_src); 564 TAILQ_INIT(&vp->v_cache_dst); 565 /* 566 * Initialize rangelocks. 567 */ 568 rangelock_init(&vp->v_rl); 569 570 vp->v_dbatchcpu = NOCPU; 571 572 mtx_lock(&vnode_list_mtx); 573 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist); 574 mtx_unlock(&vnode_list_mtx); 575 return (0); 576 } 577 578 /* 579 * Free a vnode when it is cleared from the zone. 580 */ 581 static void 582 vnode_fini(void *mem, int size) 583 { 584 struct vnode *vp; 585 struct bufobj *bo; 586 587 vp = mem; 588 vdbatch_dequeue(vp); 589 mtx_lock(&vnode_list_mtx); 590 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 591 mtx_unlock(&vnode_list_mtx); 592 rangelock_destroy(&vp->v_rl); 593 lockdestroy(vp->v_vnlock); 594 mtx_destroy(&vp->v_interlock); 595 bo = &vp->v_bufobj; 596 rw_destroy(BO_LOCKPTR(bo)); 597 } 598 599 /* 600 * Provide the size of NFS nclnode and NFS fh for calculation of the 601 * vnode memory consumption. The size is specified directly to 602 * eliminate dependency on NFS-private header. 603 * 604 * Other filesystems may use bigger or smaller (like UFS and ZFS) 605 * private inode data, but the NFS-based estimation is ample enough. 606 * Still, we care about differences in the size between 64- and 32-bit 607 * platforms. 608 * 609 * Namecache structure size is heuristically 610 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 611 */ 612 #ifdef _LP64 613 #define NFS_NCLNODE_SZ (528 + 64) 614 #define NC_SZ 148 615 #else 616 #define NFS_NCLNODE_SZ (360 + 32) 617 #define NC_SZ 92 618 #endif 619 620 static void 621 vntblinit(void *dummy __unused) 622 { 623 struct vdbatch *vd; 624 int cpu, physvnodes, virtvnodes; 625 u_int i; 626 627 /* 628 * Desiredvnodes is a function of the physical memory size and the 629 * kernel's heap size. Generally speaking, it scales with the 630 * physical memory size. The ratio of desiredvnodes to the physical 631 * memory size is 1:16 until desiredvnodes exceeds 98,304. 632 * Thereafter, the 633 * marginal ratio of desiredvnodes to the physical memory size is 634 * 1:64. However, desiredvnodes is limited by the kernel's heap 635 * size. The memory required by desiredvnodes vnodes and vm objects 636 * must not exceed 1/10th of the kernel's heap size. 637 */ 638 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 639 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 640 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 641 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 642 desiredvnodes = min(physvnodes, virtvnodes); 643 if (desiredvnodes > MAXVNODES_MAX) { 644 if (bootverbose) 645 printf("Reducing kern.maxvnodes %lu -> %lu\n", 646 desiredvnodes, MAXVNODES_MAX); 647 desiredvnodes = MAXVNODES_MAX; 648 } 649 wantfreevnodes = desiredvnodes / 4; 650 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 651 TAILQ_INIT(&vnode_list); 652 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF); 653 /* 654 * The lock is taken to appease WITNESS. 655 */ 656 mtx_lock(&vnode_list_mtx); 657 vnlru_recalc(); 658 mtx_unlock(&vnode_list_mtx); 659 vnode_list_free_marker = vn_alloc_marker(NULL); 660 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist); 661 vnode_list_reclaim_marker = vn_alloc_marker(NULL); 662 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist); 663 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 664 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 665 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 666 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 667 /* 668 * Preallocate enough nodes to support one-per buf so that 669 * we can not fail an insert. reassignbuf() callers can not 670 * tolerate the insertion failure. 671 */ 672 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 673 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 674 UMA_ZONE_NOFREE | UMA_ZONE_VM); 675 uma_prealloc(buf_trie_zone, nbuf); 676 677 vnodes_created = counter_u64_alloc(M_WAITOK); 678 recycles_count = counter_u64_alloc(M_WAITOK); 679 recycles_free_count = counter_u64_alloc(M_WAITOK); 680 deferred_inact = counter_u64_alloc(M_WAITOK); 681 682 /* 683 * Initialize the filesystem syncer. 684 */ 685 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 686 &syncer_mask); 687 syncer_maxdelay = syncer_mask + 1; 688 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 689 cv_init(&sync_wakeup, "syncer"); 690 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 691 vnsz2log++; 692 vnsz2log--; 693 694 CPU_FOREACH(cpu) { 695 vd = DPCPU_ID_PTR((cpu), vd); 696 bzero(vd, sizeof(*vd)); 697 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF); 698 } 699 } 700 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 701 702 703 /* 704 * Mark a mount point as busy. Used to synchronize access and to delay 705 * unmounting. Eventually, mountlist_mtx is not released on failure. 706 * 707 * vfs_busy() is a custom lock, it can block the caller. 708 * vfs_busy() only sleeps if the unmount is active on the mount point. 709 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 710 * vnode belonging to mp. 711 * 712 * Lookup uses vfs_busy() to traverse mount points. 713 * root fs var fs 714 * / vnode lock A / vnode lock (/var) D 715 * /var vnode lock B /log vnode lock(/var/log) E 716 * vfs_busy lock C vfs_busy lock F 717 * 718 * Within each file system, the lock order is C->A->B and F->D->E. 719 * 720 * When traversing across mounts, the system follows that lock order: 721 * 722 * C->A->B 723 * | 724 * +->F->D->E 725 * 726 * The lookup() process for namei("/var") illustrates the process: 727 * VOP_LOOKUP() obtains B while A is held 728 * vfs_busy() obtains a shared lock on F while A and B are held 729 * vput() releases lock on B 730 * vput() releases lock on A 731 * VFS_ROOT() obtains lock on D while shared lock on F is held 732 * vfs_unbusy() releases shared lock on F 733 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 734 * Attempt to lock A (instead of vp_crossmp) while D is held would 735 * violate the global order, causing deadlocks. 736 * 737 * dounmount() locks B while F is drained. 738 */ 739 int 740 vfs_busy(struct mount *mp, int flags) 741 { 742 743 MPASS((flags & ~MBF_MASK) == 0); 744 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 745 746 if (vfs_op_thread_enter(mp)) { 747 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 748 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0); 749 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0); 750 vfs_mp_count_add_pcpu(mp, ref, 1); 751 vfs_mp_count_add_pcpu(mp, lockref, 1); 752 vfs_op_thread_exit(mp); 753 if (flags & MBF_MNTLSTLOCK) 754 mtx_unlock(&mountlist_mtx); 755 return (0); 756 } 757 758 MNT_ILOCK(mp); 759 vfs_assert_mount_counters(mp); 760 MNT_REF(mp); 761 /* 762 * If mount point is currently being unmounted, sleep until the 763 * mount point fate is decided. If thread doing the unmounting fails, 764 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 765 * that this mount point has survived the unmount attempt and vfs_busy 766 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 767 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 768 * about to be really destroyed. vfs_busy needs to release its 769 * reference on the mount point in this case and return with ENOENT, 770 * telling the caller that mount mount it tried to busy is no longer 771 * valid. 772 */ 773 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 774 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 775 MNT_REL(mp); 776 MNT_IUNLOCK(mp); 777 CTR1(KTR_VFS, "%s: failed busying before sleeping", 778 __func__); 779 return (ENOENT); 780 } 781 if (flags & MBF_MNTLSTLOCK) 782 mtx_unlock(&mountlist_mtx); 783 mp->mnt_kern_flag |= MNTK_MWAIT; 784 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 785 if (flags & MBF_MNTLSTLOCK) 786 mtx_lock(&mountlist_mtx); 787 MNT_ILOCK(mp); 788 } 789 if (flags & MBF_MNTLSTLOCK) 790 mtx_unlock(&mountlist_mtx); 791 mp->mnt_lockref++; 792 MNT_IUNLOCK(mp); 793 return (0); 794 } 795 796 /* 797 * Free a busy filesystem. 798 */ 799 void 800 vfs_unbusy(struct mount *mp) 801 { 802 int c; 803 804 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 805 806 if (vfs_op_thread_enter(mp)) { 807 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 808 vfs_mp_count_sub_pcpu(mp, lockref, 1); 809 vfs_mp_count_sub_pcpu(mp, ref, 1); 810 vfs_op_thread_exit(mp); 811 return; 812 } 813 814 MNT_ILOCK(mp); 815 vfs_assert_mount_counters(mp); 816 MNT_REL(mp); 817 c = --mp->mnt_lockref; 818 if (mp->mnt_vfs_ops == 0) { 819 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 820 MNT_IUNLOCK(mp); 821 return; 822 } 823 if (c < 0) 824 vfs_dump_mount_counters(mp); 825 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 826 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 827 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 828 mp->mnt_kern_flag &= ~MNTK_DRAINING; 829 wakeup(&mp->mnt_lockref); 830 } 831 MNT_IUNLOCK(mp); 832 } 833 834 /* 835 * Lookup a mount point by filesystem identifier. 836 */ 837 struct mount * 838 vfs_getvfs(fsid_t *fsid) 839 { 840 struct mount *mp; 841 842 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 843 mtx_lock(&mountlist_mtx); 844 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 845 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 846 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 847 vfs_ref(mp); 848 mtx_unlock(&mountlist_mtx); 849 return (mp); 850 } 851 } 852 mtx_unlock(&mountlist_mtx); 853 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 854 return ((struct mount *) 0); 855 } 856 857 /* 858 * Lookup a mount point by filesystem identifier, busying it before 859 * returning. 860 * 861 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 862 * cache for popular filesystem identifiers. The cache is lockess, using 863 * the fact that struct mount's are never freed. In worst case we may 864 * get pointer to unmounted or even different filesystem, so we have to 865 * check what we got, and go slow way if so. 866 */ 867 struct mount * 868 vfs_busyfs(fsid_t *fsid) 869 { 870 #define FSID_CACHE_SIZE 256 871 typedef struct mount * volatile vmp_t; 872 static vmp_t cache[FSID_CACHE_SIZE]; 873 struct mount *mp; 874 int error; 875 uint32_t hash; 876 877 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 878 hash = fsid->val[0] ^ fsid->val[1]; 879 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 880 mp = cache[hash]; 881 if (mp == NULL || 882 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 883 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 884 goto slow; 885 if (vfs_busy(mp, 0) != 0) { 886 cache[hash] = NULL; 887 goto slow; 888 } 889 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 890 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 891 return (mp); 892 else 893 vfs_unbusy(mp); 894 895 slow: 896 mtx_lock(&mountlist_mtx); 897 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 898 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 899 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 900 error = vfs_busy(mp, MBF_MNTLSTLOCK); 901 if (error) { 902 cache[hash] = NULL; 903 mtx_unlock(&mountlist_mtx); 904 return (NULL); 905 } 906 cache[hash] = mp; 907 return (mp); 908 } 909 } 910 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 911 mtx_unlock(&mountlist_mtx); 912 return ((struct mount *) 0); 913 } 914 915 /* 916 * Check if a user can access privileged mount options. 917 */ 918 int 919 vfs_suser(struct mount *mp, struct thread *td) 920 { 921 int error; 922 923 if (jailed(td->td_ucred)) { 924 /* 925 * If the jail of the calling thread lacks permission for 926 * this type of file system, deny immediately. 927 */ 928 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 929 return (EPERM); 930 931 /* 932 * If the file system was mounted outside the jail of the 933 * calling thread, deny immediately. 934 */ 935 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 936 return (EPERM); 937 } 938 939 /* 940 * If file system supports delegated administration, we don't check 941 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 942 * by the file system itself. 943 * If this is not the user that did original mount, we check for 944 * the PRIV_VFS_MOUNT_OWNER privilege. 945 */ 946 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 947 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 948 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 949 return (error); 950 } 951 return (0); 952 } 953 954 /* 955 * Get a new unique fsid. Try to make its val[0] unique, since this value 956 * will be used to create fake device numbers for stat(). Also try (but 957 * not so hard) make its val[0] unique mod 2^16, since some emulators only 958 * support 16-bit device numbers. We end up with unique val[0]'s for the 959 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 960 * 961 * Keep in mind that several mounts may be running in parallel. Starting 962 * the search one past where the previous search terminated is both a 963 * micro-optimization and a defense against returning the same fsid to 964 * different mounts. 965 */ 966 void 967 vfs_getnewfsid(struct mount *mp) 968 { 969 static uint16_t mntid_base; 970 struct mount *nmp; 971 fsid_t tfsid; 972 int mtype; 973 974 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 975 mtx_lock(&mntid_mtx); 976 mtype = mp->mnt_vfc->vfc_typenum; 977 tfsid.val[1] = mtype; 978 mtype = (mtype & 0xFF) << 24; 979 for (;;) { 980 tfsid.val[0] = makedev(255, 981 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 982 mntid_base++; 983 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 984 break; 985 vfs_rel(nmp); 986 } 987 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 988 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 989 mtx_unlock(&mntid_mtx); 990 } 991 992 /* 993 * Knob to control the precision of file timestamps: 994 * 995 * 0 = seconds only; nanoseconds zeroed. 996 * 1 = seconds and nanoseconds, accurate within 1/HZ. 997 * 2 = seconds and nanoseconds, truncated to microseconds. 998 * >=3 = seconds and nanoseconds, maximum precision. 999 */ 1000 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 1001 1002 static int timestamp_precision = TSP_USEC; 1003 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 1004 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 1005 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 1006 "3+: sec + ns (max. precision))"); 1007 1008 /* 1009 * Get a current timestamp. 1010 */ 1011 void 1012 vfs_timestamp(struct timespec *tsp) 1013 { 1014 struct timeval tv; 1015 1016 switch (timestamp_precision) { 1017 case TSP_SEC: 1018 tsp->tv_sec = time_second; 1019 tsp->tv_nsec = 0; 1020 break; 1021 case TSP_HZ: 1022 getnanotime(tsp); 1023 break; 1024 case TSP_USEC: 1025 microtime(&tv); 1026 TIMEVAL_TO_TIMESPEC(&tv, tsp); 1027 break; 1028 case TSP_NSEC: 1029 default: 1030 nanotime(tsp); 1031 break; 1032 } 1033 } 1034 1035 /* 1036 * Set vnode attributes to VNOVAL 1037 */ 1038 void 1039 vattr_null(struct vattr *vap) 1040 { 1041 1042 vap->va_type = VNON; 1043 vap->va_size = VNOVAL; 1044 vap->va_bytes = VNOVAL; 1045 vap->va_mode = VNOVAL; 1046 vap->va_nlink = VNOVAL; 1047 vap->va_uid = VNOVAL; 1048 vap->va_gid = VNOVAL; 1049 vap->va_fsid = VNOVAL; 1050 vap->va_fileid = VNOVAL; 1051 vap->va_blocksize = VNOVAL; 1052 vap->va_rdev = VNOVAL; 1053 vap->va_atime.tv_sec = VNOVAL; 1054 vap->va_atime.tv_nsec = VNOVAL; 1055 vap->va_mtime.tv_sec = VNOVAL; 1056 vap->va_mtime.tv_nsec = VNOVAL; 1057 vap->va_ctime.tv_sec = VNOVAL; 1058 vap->va_ctime.tv_nsec = VNOVAL; 1059 vap->va_birthtime.tv_sec = VNOVAL; 1060 vap->va_birthtime.tv_nsec = VNOVAL; 1061 vap->va_flags = VNOVAL; 1062 vap->va_gen = VNOVAL; 1063 vap->va_vaflags = 0; 1064 } 1065 1066 /* 1067 * Try to reduce the total number of vnodes. 1068 * 1069 * This routine (and its user) are buggy in at least the following ways: 1070 * - all parameters were picked years ago when RAM sizes were significantly 1071 * smaller 1072 * - it can pick vnodes based on pages used by the vm object, but filesystems 1073 * like ZFS don't use it making the pick broken 1074 * - since ZFS has its own aging policy it gets partially combated by this one 1075 * - a dedicated method should be provided for filesystems to let them decide 1076 * whether the vnode should be recycled 1077 * 1078 * This routine is called when we have too many vnodes. It attempts 1079 * to free <count> vnodes and will potentially free vnodes that still 1080 * have VM backing store (VM backing store is typically the cause 1081 * of a vnode blowout so we want to do this). Therefore, this operation 1082 * is not considered cheap. 1083 * 1084 * A number of conditions may prevent a vnode from being reclaimed. 1085 * the buffer cache may have references on the vnode, a directory 1086 * vnode may still have references due to the namei cache representing 1087 * underlying files, or the vnode may be in active use. It is not 1088 * desirable to reuse such vnodes. These conditions may cause the 1089 * number of vnodes to reach some minimum value regardless of what 1090 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 1091 * 1092 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 1093 * entries if this argument is strue 1094 * @param trigger Only reclaim vnodes with fewer than this many resident 1095 * pages. 1096 * @param target How many vnodes to reclaim. 1097 * @return The number of vnodes that were reclaimed. 1098 */ 1099 static int 1100 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target) 1101 { 1102 struct vnode *vp, *mvp; 1103 struct mount *mp; 1104 u_long done; 1105 bool retried; 1106 1107 mtx_assert(&vnode_list_mtx, MA_OWNED); 1108 1109 retried = false; 1110 done = 0; 1111 1112 mvp = vnode_list_reclaim_marker; 1113 restart: 1114 vp = mvp; 1115 while (done < target) { 1116 vp = TAILQ_NEXT(vp, v_vnodelist); 1117 if (__predict_false(vp == NULL)) 1118 break; 1119 1120 if (__predict_false(vp->v_type == VMARKER)) 1121 continue; 1122 1123 /* 1124 * If it's been deconstructed already, it's still 1125 * referenced, or it exceeds the trigger, skip it. 1126 * Also skip free vnodes. We are trying to make space 1127 * to expand the free list, not reduce it. 1128 */ 1129 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1130 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src))) 1131 goto next_iter; 1132 1133 if (vp->v_type == VBAD || vp->v_type == VNON) 1134 goto next_iter; 1135 1136 if (!VI_TRYLOCK(vp)) 1137 goto next_iter; 1138 1139 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1140 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1141 vp->v_type == VBAD || vp->v_type == VNON || 1142 (vp->v_object != NULL && 1143 vp->v_object->resident_page_count > trigger)) { 1144 VI_UNLOCK(vp); 1145 goto next_iter; 1146 } 1147 vholdl(vp); 1148 VI_UNLOCK(vp); 1149 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1150 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1151 mtx_unlock(&vnode_list_mtx); 1152 1153 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1154 vdrop(vp); 1155 goto next_iter_unlocked; 1156 } 1157 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { 1158 vdrop(vp); 1159 vn_finished_write(mp); 1160 goto next_iter_unlocked; 1161 } 1162 1163 VI_LOCK(vp); 1164 if (vp->v_usecount > 0 || 1165 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1166 (vp->v_object != NULL && 1167 vp->v_object->resident_page_count > trigger)) { 1168 VOP_UNLOCK(vp); 1169 vdropl(vp); 1170 vn_finished_write(mp); 1171 goto next_iter_unlocked; 1172 } 1173 counter_u64_add(recycles_count, 1); 1174 vgonel(vp); 1175 VOP_UNLOCK(vp); 1176 vdropl(vp); 1177 vn_finished_write(mp); 1178 done++; 1179 next_iter_unlocked: 1180 if (should_yield()) 1181 kern_yield(PRI_USER); 1182 mtx_lock(&vnode_list_mtx); 1183 goto restart; 1184 next_iter: 1185 MPASS(vp->v_type != VMARKER); 1186 if (!should_yield()) 1187 continue; 1188 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1189 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1190 mtx_unlock(&vnode_list_mtx); 1191 kern_yield(PRI_USER); 1192 mtx_lock(&vnode_list_mtx); 1193 goto restart; 1194 } 1195 if (done == 0 && !retried) { 1196 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1197 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1198 retried = true; 1199 goto restart; 1200 } 1201 return (done); 1202 } 1203 1204 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1205 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1206 0, 1207 "limit on vnode free requests per call to the vnlru_free routine"); 1208 1209 /* 1210 * Attempt to reduce the free list by the requested amount. 1211 */ 1212 static int 1213 vnlru_free_locked(int count, struct vfsops *mnt_op) 1214 { 1215 struct vnode *vp, *mvp; 1216 struct mount *mp; 1217 int ocount; 1218 1219 mtx_assert(&vnode_list_mtx, MA_OWNED); 1220 if (count > max_vnlru_free) 1221 count = max_vnlru_free; 1222 ocount = count; 1223 mvp = vnode_list_free_marker; 1224 restart: 1225 vp = mvp; 1226 while (count > 0) { 1227 vp = TAILQ_NEXT(vp, v_vnodelist); 1228 if (__predict_false(vp == NULL)) { 1229 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1230 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist); 1231 break; 1232 } 1233 if (__predict_false(vp->v_type == VMARKER)) 1234 continue; 1235 1236 /* 1237 * Don't recycle if our vnode is from different type 1238 * of mount point. Note that mp is type-safe, the 1239 * check does not reach unmapped address even if 1240 * vnode is reclaimed. 1241 * Don't recycle if we can't get the interlock without 1242 * blocking. 1243 */ 1244 if (vp->v_holdcnt > 0 || (mnt_op != NULL && (mp = vp->v_mount) != NULL && 1245 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1246 continue; 1247 } 1248 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1249 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1250 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1251 VI_UNLOCK(vp); 1252 continue; 1253 } 1254 vholdl(vp); 1255 count--; 1256 mtx_unlock(&vnode_list_mtx); 1257 VI_UNLOCK(vp); 1258 vtryrecycle(vp); 1259 vdrop(vp); 1260 mtx_lock(&vnode_list_mtx); 1261 goto restart; 1262 } 1263 return (ocount - count); 1264 } 1265 1266 void 1267 vnlru_free(int count, struct vfsops *mnt_op) 1268 { 1269 1270 mtx_lock(&vnode_list_mtx); 1271 vnlru_free_locked(count, mnt_op); 1272 mtx_unlock(&vnode_list_mtx); 1273 } 1274 1275 static void 1276 vnlru_recalc(void) 1277 { 1278 1279 mtx_assert(&vnode_list_mtx, MA_OWNED); 1280 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1281 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1282 vlowat = vhiwat / 2; 1283 } 1284 1285 /* 1286 * Attempt to recycle vnodes in a context that is always safe to block. 1287 * Calling vlrurecycle() from the bowels of filesystem code has some 1288 * interesting deadlock problems. 1289 */ 1290 static struct proc *vnlruproc; 1291 static int vnlruproc_sig; 1292 1293 /* 1294 * The main freevnodes counter is only updated when threads requeue their vnode 1295 * batches. CPUs are conditionally walked to compute a more accurate total. 1296 * 1297 * Limit how much of a slop are we willing to tolerate. Note: the actual value 1298 * at any given moment can still exceed slop, but it should not be by significant 1299 * margin in practice. 1300 */ 1301 #define VNLRU_FREEVNODES_SLOP 128 1302 1303 static u_long 1304 vnlru_read_freevnodes(void) 1305 { 1306 struct vdbatch *vd; 1307 long slop; 1308 int cpu; 1309 1310 mtx_assert(&vnode_list_mtx, MA_OWNED); 1311 if (freevnodes > freevnodes_old) 1312 slop = freevnodes - freevnodes_old; 1313 else 1314 slop = freevnodes_old - freevnodes; 1315 if (slop < VNLRU_FREEVNODES_SLOP) 1316 return (freevnodes >= 0 ? freevnodes : 0); 1317 freevnodes_old = freevnodes; 1318 CPU_FOREACH(cpu) { 1319 vd = DPCPU_ID_PTR((cpu), vd); 1320 freevnodes_old += vd->freevnodes; 1321 } 1322 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1323 } 1324 1325 static bool 1326 vnlru_under(u_long rnumvnodes, u_long limit) 1327 { 1328 u_long rfreevnodes, space; 1329 1330 if (__predict_false(rnumvnodes > desiredvnodes)) 1331 return (true); 1332 1333 space = desiredvnodes - rnumvnodes; 1334 if (space < limit) { 1335 rfreevnodes = vnlru_read_freevnodes(); 1336 if (rfreevnodes > wantfreevnodes) 1337 space += rfreevnodes - wantfreevnodes; 1338 } 1339 return (space < limit); 1340 } 1341 1342 static bool 1343 vnlru_under_unlocked(u_long rnumvnodes, u_long limit) 1344 { 1345 long rfreevnodes, space; 1346 1347 if (__predict_false(rnumvnodes > desiredvnodes)) 1348 return (true); 1349 1350 space = desiredvnodes - rnumvnodes; 1351 if (space < limit) { 1352 rfreevnodes = atomic_load_long(&freevnodes); 1353 if (rfreevnodes > wantfreevnodes) 1354 space += rfreevnodes - wantfreevnodes; 1355 } 1356 return (space < limit); 1357 } 1358 1359 static void 1360 vnlru_kick(void) 1361 { 1362 1363 mtx_assert(&vnode_list_mtx, MA_OWNED); 1364 if (vnlruproc_sig == 0) { 1365 vnlruproc_sig = 1; 1366 wakeup(vnlruproc); 1367 } 1368 } 1369 1370 static void 1371 vnlru_proc(void) 1372 { 1373 u_long rnumvnodes, rfreevnodes, target; 1374 unsigned long onumvnodes; 1375 int done, force, trigger, usevnodes; 1376 bool reclaim_nc_src, want_reread; 1377 1378 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1379 SHUTDOWN_PRI_FIRST); 1380 1381 force = 0; 1382 want_reread = false; 1383 for (;;) { 1384 kproc_suspend_check(vnlruproc); 1385 mtx_lock(&vnode_list_mtx); 1386 rnumvnodes = atomic_load_long(&numvnodes); 1387 1388 if (want_reread) { 1389 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1390 want_reread = false; 1391 } 1392 1393 /* 1394 * If numvnodes is too large (due to desiredvnodes being 1395 * adjusted using its sysctl, or emergency growth), first 1396 * try to reduce it by discarding from the free list. 1397 */ 1398 if (rnumvnodes > desiredvnodes) { 1399 vnlru_free_locked(rnumvnodes - desiredvnodes, NULL); 1400 rnumvnodes = atomic_load_long(&numvnodes); 1401 } 1402 /* 1403 * Sleep if the vnode cache is in a good state. This is 1404 * when it is not over-full and has space for about a 4% 1405 * or 9% expansion (by growing its size or inexcessively 1406 * reducing its free list). Otherwise, try to reclaim 1407 * space for a 10% expansion. 1408 */ 1409 if (vstir && force == 0) { 1410 force = 1; 1411 vstir = 0; 1412 } 1413 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1414 vnlruproc_sig = 0; 1415 wakeup(&vnlruproc_sig); 1416 msleep(vnlruproc, &vnode_list_mtx, 1417 PVFS|PDROP, "vlruwt", hz); 1418 continue; 1419 } 1420 rfreevnodes = vnlru_read_freevnodes(); 1421 1422 onumvnodes = rnumvnodes; 1423 /* 1424 * Calculate parameters for recycling. These are the same 1425 * throughout the loop to give some semblance of fairness. 1426 * The trigger point is to avoid recycling vnodes with lots 1427 * of resident pages. We aren't trying to free memory; we 1428 * are trying to recycle or at least free vnodes. 1429 */ 1430 if (rnumvnodes <= desiredvnodes) 1431 usevnodes = rnumvnodes - rfreevnodes; 1432 else 1433 usevnodes = rnumvnodes; 1434 if (usevnodes <= 0) 1435 usevnodes = 1; 1436 /* 1437 * The trigger value is is chosen to give a conservatively 1438 * large value to ensure that it alone doesn't prevent 1439 * making progress. The value can easily be so large that 1440 * it is effectively infinite in some congested and 1441 * misconfigured cases, and this is necessary. Normally 1442 * it is about 8 to 100 (pages), which is quite large. 1443 */ 1444 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1445 if (force < 2) 1446 trigger = vsmalltrigger; 1447 reclaim_nc_src = force >= 3; 1448 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1449 target = target / 10 + 1; 1450 done = vlrureclaim(reclaim_nc_src, trigger, target); 1451 mtx_unlock(&vnode_list_mtx); 1452 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1453 uma_reclaim(UMA_RECLAIM_DRAIN); 1454 if (done == 0) { 1455 if (force == 0 || force == 1) { 1456 force = 2; 1457 continue; 1458 } 1459 if (force == 2) { 1460 force = 3; 1461 continue; 1462 } 1463 want_reread = true; 1464 force = 0; 1465 vnlru_nowhere++; 1466 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1467 } else { 1468 want_reread = true; 1469 kern_yield(PRI_USER); 1470 } 1471 } 1472 } 1473 1474 static struct kproc_desc vnlru_kp = { 1475 "vnlru", 1476 vnlru_proc, 1477 &vnlruproc 1478 }; 1479 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1480 &vnlru_kp); 1481 1482 /* 1483 * Routines having to do with the management of the vnode table. 1484 */ 1485 1486 /* 1487 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1488 * before we actually vgone(). This function must be called with the vnode 1489 * held to prevent the vnode from being returned to the free list midway 1490 * through vgone(). 1491 */ 1492 static int 1493 vtryrecycle(struct vnode *vp) 1494 { 1495 struct mount *vnmp; 1496 1497 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1498 VNASSERT(vp->v_holdcnt, vp, 1499 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1500 /* 1501 * This vnode may found and locked via some other list, if so we 1502 * can't recycle it yet. 1503 */ 1504 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1505 CTR2(KTR_VFS, 1506 "%s: impossible to recycle, vp %p lock is already held", 1507 __func__, vp); 1508 return (EWOULDBLOCK); 1509 } 1510 /* 1511 * Don't recycle if its filesystem is being suspended. 1512 */ 1513 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1514 VOP_UNLOCK(vp); 1515 CTR2(KTR_VFS, 1516 "%s: impossible to recycle, cannot start the write for %p", 1517 __func__, vp); 1518 return (EBUSY); 1519 } 1520 /* 1521 * If we got this far, we need to acquire the interlock and see if 1522 * anyone picked up this vnode from another list. If not, we will 1523 * mark it with DOOMED via vgonel() so that anyone who does find it 1524 * will skip over it. 1525 */ 1526 VI_LOCK(vp); 1527 if (vp->v_usecount) { 1528 VOP_UNLOCK(vp); 1529 VI_UNLOCK(vp); 1530 vn_finished_write(vnmp); 1531 CTR2(KTR_VFS, 1532 "%s: impossible to recycle, %p is already referenced", 1533 __func__, vp); 1534 return (EBUSY); 1535 } 1536 if (!VN_IS_DOOMED(vp)) { 1537 counter_u64_add(recycles_free_count, 1); 1538 vgonel(vp); 1539 } 1540 VOP_UNLOCK(vp); 1541 VI_UNLOCK(vp); 1542 vn_finished_write(vnmp); 1543 return (0); 1544 } 1545 1546 /* 1547 * Allocate a new vnode. 1548 * 1549 * The operation never returns an error. Returning an error was disabled 1550 * in r145385 (dated 2005) with the following comment: 1551 * 1552 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1553 * 1554 * Given the age of this commit (almost 15 years at the time of writing this 1555 * comment) restoring the ability to fail requires a significant audit of 1556 * all codepaths. 1557 * 1558 * The routine can try to free a vnode or stall for up to 1 second waiting for 1559 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1560 */ 1561 static u_long vn_alloc_cyclecount; 1562 1563 static struct vnode * __noinline 1564 vn_alloc_hard(struct mount *mp) 1565 { 1566 u_long rnumvnodes, rfreevnodes; 1567 1568 mtx_lock(&vnode_list_mtx); 1569 rnumvnodes = atomic_load_long(&numvnodes); 1570 if (rnumvnodes + 1 < desiredvnodes) { 1571 vn_alloc_cyclecount = 0; 1572 goto alloc; 1573 } 1574 rfreevnodes = vnlru_read_freevnodes(); 1575 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1576 vn_alloc_cyclecount = 0; 1577 vstir = 1; 1578 } 1579 /* 1580 * Grow the vnode cache if it will not be above its target max 1581 * after growing. Otherwise, if the free list is nonempty, try 1582 * to reclaim 1 item from it before growing the cache (possibly 1583 * above its target max if the reclamation failed or is delayed). 1584 * Otherwise, wait for some space. In all cases, schedule 1585 * vnlru_proc() if we are getting short of space. The watermarks 1586 * should be chosen so that we never wait or even reclaim from 1587 * the free list to below its target minimum. 1588 */ 1589 if (vnlru_free_locked(1, NULL) > 0) 1590 goto alloc; 1591 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1592 /* 1593 * Wait for space for a new vnode. 1594 */ 1595 vnlru_kick(); 1596 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1597 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1598 vnlru_read_freevnodes() > 1) 1599 vnlru_free_locked(1, NULL); 1600 } 1601 alloc: 1602 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1603 if (vnlru_under(rnumvnodes, vlowat)) 1604 vnlru_kick(); 1605 mtx_unlock(&vnode_list_mtx); 1606 return (uma_zalloc(vnode_zone, M_WAITOK)); 1607 } 1608 1609 static struct vnode * 1610 vn_alloc(struct mount *mp) 1611 { 1612 u_long rnumvnodes; 1613 1614 if (__predict_false(vn_alloc_cyclecount != 0)) 1615 return (vn_alloc_hard(mp)); 1616 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1617 if (__predict_false(vnlru_under_unlocked(rnumvnodes, vlowat))) { 1618 atomic_subtract_long(&numvnodes, 1); 1619 return (vn_alloc_hard(mp)); 1620 } 1621 1622 return (uma_zalloc(vnode_zone, M_WAITOK)); 1623 } 1624 1625 static void 1626 vn_free(struct vnode *vp) 1627 { 1628 1629 atomic_subtract_long(&numvnodes, 1); 1630 uma_zfree(vnode_zone, vp); 1631 } 1632 1633 /* 1634 * Return the next vnode from the free list. 1635 */ 1636 int 1637 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1638 struct vnode **vpp) 1639 { 1640 struct vnode *vp; 1641 struct thread *td; 1642 struct lock_object *lo; 1643 1644 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1645 1646 KASSERT(vops->registered, 1647 ("%s: not registered vector op %p\n", __func__, vops)); 1648 1649 td = curthread; 1650 if (td->td_vp_reserved != NULL) { 1651 vp = td->td_vp_reserved; 1652 td->td_vp_reserved = NULL; 1653 } else { 1654 vp = vn_alloc(mp); 1655 } 1656 counter_u64_add(vnodes_created, 1); 1657 /* 1658 * Locks are given the generic name "vnode" when created. 1659 * Follow the historic practice of using the filesystem 1660 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1661 * 1662 * Locks live in a witness group keyed on their name. Thus, 1663 * when a lock is renamed, it must also move from the witness 1664 * group of its old name to the witness group of its new name. 1665 * 1666 * The change only needs to be made when the vnode moves 1667 * from one filesystem type to another. We ensure that each 1668 * filesystem use a single static name pointer for its tag so 1669 * that we can compare pointers rather than doing a strcmp(). 1670 */ 1671 lo = &vp->v_vnlock->lock_object; 1672 #ifdef WITNESS 1673 if (lo->lo_name != tag) { 1674 #endif 1675 lo->lo_name = tag; 1676 #ifdef WITNESS 1677 WITNESS_DESTROY(lo); 1678 WITNESS_INIT(lo, tag); 1679 } 1680 #endif 1681 /* 1682 * By default, don't allow shared locks unless filesystems opt-in. 1683 */ 1684 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1685 /* 1686 * Finalize various vnode identity bits. 1687 */ 1688 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1689 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1690 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1691 vp->v_type = VNON; 1692 vp->v_op = vops; 1693 v_init_counters(vp); 1694 vp->v_bufobj.bo_ops = &buf_ops_bio; 1695 #ifdef DIAGNOSTIC 1696 if (mp == NULL && vops != &dead_vnodeops) 1697 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1698 #endif 1699 #ifdef MAC 1700 mac_vnode_init(vp); 1701 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1702 mac_vnode_associate_singlelabel(mp, vp); 1703 #endif 1704 if (mp != NULL) { 1705 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1706 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1707 vp->v_vflag |= VV_NOKNOTE; 1708 } 1709 1710 /* 1711 * For the filesystems which do not use vfs_hash_insert(), 1712 * still initialize v_hash to have vfs_hash_index() useful. 1713 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1714 * its own hashing. 1715 */ 1716 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1717 1718 *vpp = vp; 1719 return (0); 1720 } 1721 1722 void 1723 getnewvnode_reserve(void) 1724 { 1725 struct thread *td; 1726 1727 td = curthread; 1728 MPASS(td->td_vp_reserved == NULL); 1729 td->td_vp_reserved = vn_alloc(NULL); 1730 } 1731 1732 void 1733 getnewvnode_drop_reserve(void) 1734 { 1735 struct thread *td; 1736 1737 td = curthread; 1738 if (td->td_vp_reserved != NULL) { 1739 vn_free(td->td_vp_reserved); 1740 td->td_vp_reserved = NULL; 1741 } 1742 } 1743 1744 static void 1745 freevnode(struct vnode *vp) 1746 { 1747 struct bufobj *bo; 1748 1749 /* 1750 * The vnode has been marked for destruction, so free it. 1751 * 1752 * The vnode will be returned to the zone where it will 1753 * normally remain until it is needed for another vnode. We 1754 * need to cleanup (or verify that the cleanup has already 1755 * been done) any residual data left from its current use 1756 * so as not to contaminate the freshly allocated vnode. 1757 */ 1758 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1759 bo = &vp->v_bufobj; 1760 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1761 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 1762 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1763 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1764 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1765 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1766 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1767 ("clean blk trie not empty")); 1768 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1769 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1770 ("dirty blk trie not empty")); 1771 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1772 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1773 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1774 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1775 ("Dangling rangelock waiters")); 1776 VI_UNLOCK(vp); 1777 #ifdef MAC 1778 mac_vnode_destroy(vp); 1779 #endif 1780 if (vp->v_pollinfo != NULL) { 1781 destroy_vpollinfo(vp->v_pollinfo); 1782 vp->v_pollinfo = NULL; 1783 } 1784 #ifdef INVARIANTS 1785 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1786 vp->v_op = NULL; 1787 #endif 1788 vp->v_mountedhere = NULL; 1789 vp->v_unpcb = NULL; 1790 vp->v_rdev = NULL; 1791 vp->v_fifoinfo = NULL; 1792 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1793 vp->v_irflag = 0; 1794 vp->v_iflag = 0; 1795 vp->v_vflag = 0; 1796 bo->bo_flag = 0; 1797 vn_free(vp); 1798 } 1799 1800 /* 1801 * Delete from old mount point vnode list, if on one. 1802 */ 1803 static void 1804 delmntque(struct vnode *vp) 1805 { 1806 struct mount *mp; 1807 1808 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 1809 1810 mp = vp->v_mount; 1811 if (mp == NULL) 1812 return; 1813 MNT_ILOCK(mp); 1814 VI_LOCK(vp); 1815 vp->v_mount = NULL; 1816 VI_UNLOCK(vp); 1817 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1818 ("bad mount point vnode list size")); 1819 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1820 mp->mnt_nvnodelistsize--; 1821 MNT_REL(mp); 1822 MNT_IUNLOCK(mp); 1823 } 1824 1825 static void 1826 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1827 { 1828 1829 vp->v_data = NULL; 1830 vp->v_op = &dead_vnodeops; 1831 vgone(vp); 1832 vput(vp); 1833 } 1834 1835 /* 1836 * Insert into list of vnodes for the new mount point, if available. 1837 */ 1838 int 1839 insmntque1(struct vnode *vp, struct mount *mp, 1840 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1841 { 1842 1843 KASSERT(vp->v_mount == NULL, 1844 ("insmntque: vnode already on per mount vnode list")); 1845 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1846 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1847 1848 /* 1849 * We acquire the vnode interlock early to ensure that the 1850 * vnode cannot be recycled by another process releasing a 1851 * holdcnt on it before we get it on both the vnode list 1852 * and the active vnode list. The mount mutex protects only 1853 * manipulation of the vnode list and the vnode freelist 1854 * mutex protects only manipulation of the active vnode list. 1855 * Hence the need to hold the vnode interlock throughout. 1856 */ 1857 MNT_ILOCK(mp); 1858 VI_LOCK(vp); 1859 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1860 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1861 mp->mnt_nvnodelistsize == 0)) && 1862 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1863 VI_UNLOCK(vp); 1864 MNT_IUNLOCK(mp); 1865 if (dtr != NULL) 1866 dtr(vp, dtr_arg); 1867 return (EBUSY); 1868 } 1869 vp->v_mount = mp; 1870 MNT_REF(mp); 1871 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1872 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1873 ("neg mount point vnode list size")); 1874 mp->mnt_nvnodelistsize++; 1875 VI_UNLOCK(vp); 1876 MNT_IUNLOCK(mp); 1877 return (0); 1878 } 1879 1880 int 1881 insmntque(struct vnode *vp, struct mount *mp) 1882 { 1883 1884 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1885 } 1886 1887 /* 1888 * Flush out and invalidate all buffers associated with a bufobj 1889 * Called with the underlying object locked. 1890 */ 1891 int 1892 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1893 { 1894 int error; 1895 1896 BO_LOCK(bo); 1897 if (flags & V_SAVE) { 1898 error = bufobj_wwait(bo, slpflag, slptimeo); 1899 if (error) { 1900 BO_UNLOCK(bo); 1901 return (error); 1902 } 1903 if (bo->bo_dirty.bv_cnt > 0) { 1904 BO_UNLOCK(bo); 1905 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1906 return (error); 1907 /* 1908 * XXX We could save a lock/unlock if this was only 1909 * enabled under INVARIANTS 1910 */ 1911 BO_LOCK(bo); 1912 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1913 panic("vinvalbuf: dirty bufs"); 1914 } 1915 } 1916 /* 1917 * If you alter this loop please notice that interlock is dropped and 1918 * reacquired in flushbuflist. Special care is needed to ensure that 1919 * no race conditions occur from this. 1920 */ 1921 do { 1922 error = flushbuflist(&bo->bo_clean, 1923 flags, bo, slpflag, slptimeo); 1924 if (error == 0 && !(flags & V_CLEANONLY)) 1925 error = flushbuflist(&bo->bo_dirty, 1926 flags, bo, slpflag, slptimeo); 1927 if (error != 0 && error != EAGAIN) { 1928 BO_UNLOCK(bo); 1929 return (error); 1930 } 1931 } while (error != 0); 1932 1933 /* 1934 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1935 * have write I/O in-progress but if there is a VM object then the 1936 * VM object can also have read-I/O in-progress. 1937 */ 1938 do { 1939 bufobj_wwait(bo, 0, 0); 1940 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1941 BO_UNLOCK(bo); 1942 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1943 BO_LOCK(bo); 1944 } 1945 } while (bo->bo_numoutput > 0); 1946 BO_UNLOCK(bo); 1947 1948 /* 1949 * Destroy the copy in the VM cache, too. 1950 */ 1951 if (bo->bo_object != NULL && 1952 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1953 VM_OBJECT_WLOCK(bo->bo_object); 1954 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1955 OBJPR_CLEANONLY : 0); 1956 VM_OBJECT_WUNLOCK(bo->bo_object); 1957 } 1958 1959 #ifdef INVARIANTS 1960 BO_LOCK(bo); 1961 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1962 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1963 bo->bo_clean.bv_cnt > 0)) 1964 panic("vinvalbuf: flush failed"); 1965 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1966 bo->bo_dirty.bv_cnt > 0) 1967 panic("vinvalbuf: flush dirty failed"); 1968 BO_UNLOCK(bo); 1969 #endif 1970 return (0); 1971 } 1972 1973 /* 1974 * Flush out and invalidate all buffers associated with a vnode. 1975 * Called with the underlying object locked. 1976 */ 1977 int 1978 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1979 { 1980 1981 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1982 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1983 if (vp->v_object != NULL && vp->v_object->handle != vp) 1984 return (0); 1985 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1986 } 1987 1988 /* 1989 * Flush out buffers on the specified list. 1990 * 1991 */ 1992 static int 1993 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1994 int slptimeo) 1995 { 1996 struct buf *bp, *nbp; 1997 int retval, error; 1998 daddr_t lblkno; 1999 b_xflags_t xflags; 2000 2001 ASSERT_BO_WLOCKED(bo); 2002 2003 retval = 0; 2004 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2005 /* 2006 * If we are flushing both V_NORMAL and V_ALT buffers then 2007 * do not skip any buffers. If we are flushing only V_NORMAL 2008 * buffers then skip buffers marked as BX_ALTDATA. If we are 2009 * flushing only V_ALT buffers then skip buffers not marked 2010 * as BX_ALTDATA. 2011 */ 2012 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2013 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2014 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2015 continue; 2016 } 2017 if (nbp != NULL) { 2018 lblkno = nbp->b_lblkno; 2019 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2020 } 2021 retval = EAGAIN; 2022 error = BUF_TIMELOCK(bp, 2023 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2024 "flushbuf", slpflag, slptimeo); 2025 if (error) { 2026 BO_LOCK(bo); 2027 return (error != ENOLCK ? error : EAGAIN); 2028 } 2029 KASSERT(bp->b_bufobj == bo, 2030 ("bp %p wrong b_bufobj %p should be %p", 2031 bp, bp->b_bufobj, bo)); 2032 /* 2033 * XXX Since there are no node locks for NFS, I 2034 * believe there is a slight chance that a delayed 2035 * write will occur while sleeping just above, so 2036 * check for it. 2037 */ 2038 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2039 (flags & V_SAVE)) { 2040 bremfree(bp); 2041 bp->b_flags |= B_ASYNC; 2042 bwrite(bp); 2043 BO_LOCK(bo); 2044 return (EAGAIN); /* XXX: why not loop ? */ 2045 } 2046 bremfree(bp); 2047 bp->b_flags |= (B_INVAL | B_RELBUF); 2048 bp->b_flags &= ~B_ASYNC; 2049 brelse(bp); 2050 BO_LOCK(bo); 2051 if (nbp == NULL) 2052 break; 2053 nbp = gbincore(bo, lblkno); 2054 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2055 != xflags) 2056 break; /* nbp invalid */ 2057 } 2058 return (retval); 2059 } 2060 2061 int 2062 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2063 { 2064 struct buf *bp; 2065 int error; 2066 daddr_t lblkno; 2067 2068 ASSERT_BO_LOCKED(bo); 2069 2070 for (lblkno = startn;;) { 2071 again: 2072 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2073 if (bp == NULL || bp->b_lblkno >= endn || 2074 bp->b_lblkno < startn) 2075 break; 2076 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2077 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2078 if (error != 0) { 2079 BO_RLOCK(bo); 2080 if (error == ENOLCK) 2081 goto again; 2082 return (error); 2083 } 2084 KASSERT(bp->b_bufobj == bo, 2085 ("bp %p wrong b_bufobj %p should be %p", 2086 bp, bp->b_bufobj, bo)); 2087 lblkno = bp->b_lblkno + 1; 2088 if ((bp->b_flags & B_MANAGED) == 0) 2089 bremfree(bp); 2090 bp->b_flags |= B_RELBUF; 2091 /* 2092 * In the VMIO case, use the B_NOREUSE flag to hint that the 2093 * pages backing each buffer in the range are unlikely to be 2094 * reused. Dirty buffers will have the hint applied once 2095 * they've been written. 2096 */ 2097 if ((bp->b_flags & B_VMIO) != 0) 2098 bp->b_flags |= B_NOREUSE; 2099 brelse(bp); 2100 BO_RLOCK(bo); 2101 } 2102 return (0); 2103 } 2104 2105 /* 2106 * Truncate a file's buffer and pages to a specified length. This 2107 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2108 * sync activity. 2109 */ 2110 int 2111 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2112 { 2113 struct buf *bp, *nbp; 2114 struct bufobj *bo; 2115 daddr_t startlbn; 2116 2117 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2118 vp, blksize, (uintmax_t)length); 2119 2120 /* 2121 * Round up to the *next* lbn. 2122 */ 2123 startlbn = howmany(length, blksize); 2124 2125 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2126 2127 bo = &vp->v_bufobj; 2128 restart_unlocked: 2129 BO_LOCK(bo); 2130 2131 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2132 ; 2133 2134 if (length > 0) { 2135 restartsync: 2136 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2137 if (bp->b_lblkno > 0) 2138 continue; 2139 /* 2140 * Since we hold the vnode lock this should only 2141 * fail if we're racing with the buf daemon. 2142 */ 2143 if (BUF_LOCK(bp, 2144 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2145 BO_LOCKPTR(bo)) == ENOLCK) 2146 goto restart_unlocked; 2147 2148 VNASSERT((bp->b_flags & B_DELWRI), vp, 2149 ("buf(%p) on dirty queue without DELWRI", bp)); 2150 2151 bremfree(bp); 2152 bawrite(bp); 2153 BO_LOCK(bo); 2154 goto restartsync; 2155 } 2156 } 2157 2158 bufobj_wwait(bo, 0, 0); 2159 BO_UNLOCK(bo); 2160 vnode_pager_setsize(vp, length); 2161 2162 return (0); 2163 } 2164 2165 /* 2166 * Invalidate the cached pages of a file's buffer within the range of block 2167 * numbers [startlbn, endlbn). 2168 */ 2169 void 2170 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2171 int blksize) 2172 { 2173 struct bufobj *bo; 2174 off_t start, end; 2175 2176 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2177 2178 start = blksize * startlbn; 2179 end = blksize * endlbn; 2180 2181 bo = &vp->v_bufobj; 2182 BO_LOCK(bo); 2183 MPASS(blksize == bo->bo_bsize); 2184 2185 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2186 ; 2187 2188 BO_UNLOCK(bo); 2189 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2190 } 2191 2192 static int 2193 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2194 daddr_t startlbn, daddr_t endlbn) 2195 { 2196 struct buf *bp, *nbp; 2197 bool anyfreed; 2198 2199 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2200 ASSERT_BO_LOCKED(bo); 2201 2202 do { 2203 anyfreed = false; 2204 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2205 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2206 continue; 2207 if (BUF_LOCK(bp, 2208 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2209 BO_LOCKPTR(bo)) == ENOLCK) { 2210 BO_LOCK(bo); 2211 return (EAGAIN); 2212 } 2213 2214 bremfree(bp); 2215 bp->b_flags |= B_INVAL | B_RELBUF; 2216 bp->b_flags &= ~B_ASYNC; 2217 brelse(bp); 2218 anyfreed = true; 2219 2220 BO_LOCK(bo); 2221 if (nbp != NULL && 2222 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2223 nbp->b_vp != vp || 2224 (nbp->b_flags & B_DELWRI) != 0)) 2225 return (EAGAIN); 2226 } 2227 2228 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2229 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2230 continue; 2231 if (BUF_LOCK(bp, 2232 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2233 BO_LOCKPTR(bo)) == ENOLCK) { 2234 BO_LOCK(bo); 2235 return (EAGAIN); 2236 } 2237 bremfree(bp); 2238 bp->b_flags |= B_INVAL | B_RELBUF; 2239 bp->b_flags &= ~B_ASYNC; 2240 brelse(bp); 2241 anyfreed = true; 2242 2243 BO_LOCK(bo); 2244 if (nbp != NULL && 2245 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2246 (nbp->b_vp != vp) || 2247 (nbp->b_flags & B_DELWRI) == 0)) 2248 return (EAGAIN); 2249 } 2250 } while (anyfreed); 2251 return (0); 2252 } 2253 2254 static void 2255 buf_vlist_remove(struct buf *bp) 2256 { 2257 struct bufv *bv; 2258 2259 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2260 ASSERT_BO_WLOCKED(bp->b_bufobj); 2261 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 2262 (BX_VNDIRTY|BX_VNCLEAN), 2263 ("buf_vlist_remove: Buf %p is on two lists", bp)); 2264 if (bp->b_xflags & BX_VNDIRTY) 2265 bv = &bp->b_bufobj->bo_dirty; 2266 else 2267 bv = &bp->b_bufobj->bo_clean; 2268 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2269 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2270 bv->bv_cnt--; 2271 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2272 } 2273 2274 /* 2275 * Add the buffer to the sorted clean or dirty block list. 2276 * 2277 * NOTE: xflags is passed as a constant, optimizing this inline function! 2278 */ 2279 static void 2280 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2281 { 2282 struct bufv *bv; 2283 struct buf *n; 2284 int error; 2285 2286 ASSERT_BO_WLOCKED(bo); 2287 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2288 ("dead bo %p", bo)); 2289 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2290 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2291 bp->b_xflags |= xflags; 2292 if (xflags & BX_VNDIRTY) 2293 bv = &bo->bo_dirty; 2294 else 2295 bv = &bo->bo_clean; 2296 2297 /* 2298 * Keep the list ordered. Optimize empty list insertion. Assume 2299 * we tend to grow at the tail so lookup_le should usually be cheaper 2300 * than _ge. 2301 */ 2302 if (bv->bv_cnt == 0 || 2303 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2304 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2305 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2306 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2307 else 2308 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2309 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2310 if (error) 2311 panic("buf_vlist_add: Preallocated nodes insufficient."); 2312 bv->bv_cnt++; 2313 } 2314 2315 /* 2316 * Look up a buffer using the buffer tries. 2317 */ 2318 struct buf * 2319 gbincore(struct bufobj *bo, daddr_t lblkno) 2320 { 2321 struct buf *bp; 2322 2323 ASSERT_BO_LOCKED(bo); 2324 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2325 if (bp != NULL) 2326 return (bp); 2327 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2328 } 2329 2330 /* 2331 * Associate a buffer with a vnode. 2332 */ 2333 void 2334 bgetvp(struct vnode *vp, struct buf *bp) 2335 { 2336 struct bufobj *bo; 2337 2338 bo = &vp->v_bufobj; 2339 ASSERT_BO_WLOCKED(bo); 2340 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2341 2342 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2343 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2344 ("bgetvp: bp already attached! %p", bp)); 2345 2346 vhold(vp); 2347 bp->b_vp = vp; 2348 bp->b_bufobj = bo; 2349 /* 2350 * Insert onto list for new vnode. 2351 */ 2352 buf_vlist_add(bp, bo, BX_VNCLEAN); 2353 } 2354 2355 /* 2356 * Disassociate a buffer from a vnode. 2357 */ 2358 void 2359 brelvp(struct buf *bp) 2360 { 2361 struct bufobj *bo; 2362 struct vnode *vp; 2363 2364 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2365 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2366 2367 /* 2368 * Delete from old vnode list, if on one. 2369 */ 2370 vp = bp->b_vp; /* XXX */ 2371 bo = bp->b_bufobj; 2372 BO_LOCK(bo); 2373 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2374 buf_vlist_remove(bp); 2375 else 2376 panic("brelvp: Buffer %p not on queue.", bp); 2377 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2378 bo->bo_flag &= ~BO_ONWORKLST; 2379 mtx_lock(&sync_mtx); 2380 LIST_REMOVE(bo, bo_synclist); 2381 syncer_worklist_len--; 2382 mtx_unlock(&sync_mtx); 2383 } 2384 bp->b_vp = NULL; 2385 bp->b_bufobj = NULL; 2386 BO_UNLOCK(bo); 2387 vdrop(vp); 2388 } 2389 2390 /* 2391 * Add an item to the syncer work queue. 2392 */ 2393 static void 2394 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2395 { 2396 int slot; 2397 2398 ASSERT_BO_WLOCKED(bo); 2399 2400 mtx_lock(&sync_mtx); 2401 if (bo->bo_flag & BO_ONWORKLST) 2402 LIST_REMOVE(bo, bo_synclist); 2403 else { 2404 bo->bo_flag |= BO_ONWORKLST; 2405 syncer_worklist_len++; 2406 } 2407 2408 if (delay > syncer_maxdelay - 2) 2409 delay = syncer_maxdelay - 2; 2410 slot = (syncer_delayno + delay) & syncer_mask; 2411 2412 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2413 mtx_unlock(&sync_mtx); 2414 } 2415 2416 static int 2417 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2418 { 2419 int error, len; 2420 2421 mtx_lock(&sync_mtx); 2422 len = syncer_worklist_len - sync_vnode_count; 2423 mtx_unlock(&sync_mtx); 2424 error = SYSCTL_OUT(req, &len, sizeof(len)); 2425 return (error); 2426 } 2427 2428 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2429 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2430 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2431 2432 static struct proc *updateproc; 2433 static void sched_sync(void); 2434 static struct kproc_desc up_kp = { 2435 "syncer", 2436 sched_sync, 2437 &updateproc 2438 }; 2439 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2440 2441 static int 2442 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2443 { 2444 struct vnode *vp; 2445 struct mount *mp; 2446 2447 *bo = LIST_FIRST(slp); 2448 if (*bo == NULL) 2449 return (0); 2450 vp = bo2vnode(*bo); 2451 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2452 return (1); 2453 /* 2454 * We use vhold in case the vnode does not 2455 * successfully sync. vhold prevents the vnode from 2456 * going away when we unlock the sync_mtx so that 2457 * we can acquire the vnode interlock. 2458 */ 2459 vholdl(vp); 2460 mtx_unlock(&sync_mtx); 2461 VI_UNLOCK(vp); 2462 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2463 vdrop(vp); 2464 mtx_lock(&sync_mtx); 2465 return (*bo == LIST_FIRST(slp)); 2466 } 2467 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2468 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2469 VOP_UNLOCK(vp); 2470 vn_finished_write(mp); 2471 BO_LOCK(*bo); 2472 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2473 /* 2474 * Put us back on the worklist. The worklist 2475 * routine will remove us from our current 2476 * position and then add us back in at a later 2477 * position. 2478 */ 2479 vn_syncer_add_to_worklist(*bo, syncdelay); 2480 } 2481 BO_UNLOCK(*bo); 2482 vdrop(vp); 2483 mtx_lock(&sync_mtx); 2484 return (0); 2485 } 2486 2487 static int first_printf = 1; 2488 2489 /* 2490 * System filesystem synchronizer daemon. 2491 */ 2492 static void 2493 sched_sync(void) 2494 { 2495 struct synclist *next, *slp; 2496 struct bufobj *bo; 2497 long starttime; 2498 struct thread *td = curthread; 2499 int last_work_seen; 2500 int net_worklist_len; 2501 int syncer_final_iter; 2502 int error; 2503 2504 last_work_seen = 0; 2505 syncer_final_iter = 0; 2506 syncer_state = SYNCER_RUNNING; 2507 starttime = time_uptime; 2508 td->td_pflags |= TDP_NORUNNINGBUF; 2509 2510 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2511 SHUTDOWN_PRI_LAST); 2512 2513 mtx_lock(&sync_mtx); 2514 for (;;) { 2515 if (syncer_state == SYNCER_FINAL_DELAY && 2516 syncer_final_iter == 0) { 2517 mtx_unlock(&sync_mtx); 2518 kproc_suspend_check(td->td_proc); 2519 mtx_lock(&sync_mtx); 2520 } 2521 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2522 if (syncer_state != SYNCER_RUNNING && 2523 starttime != time_uptime) { 2524 if (first_printf) { 2525 printf("\nSyncing disks, vnodes remaining... "); 2526 first_printf = 0; 2527 } 2528 printf("%d ", net_worklist_len); 2529 } 2530 starttime = time_uptime; 2531 2532 /* 2533 * Push files whose dirty time has expired. Be careful 2534 * of interrupt race on slp queue. 2535 * 2536 * Skip over empty worklist slots when shutting down. 2537 */ 2538 do { 2539 slp = &syncer_workitem_pending[syncer_delayno]; 2540 syncer_delayno += 1; 2541 if (syncer_delayno == syncer_maxdelay) 2542 syncer_delayno = 0; 2543 next = &syncer_workitem_pending[syncer_delayno]; 2544 /* 2545 * If the worklist has wrapped since the 2546 * it was emptied of all but syncer vnodes, 2547 * switch to the FINAL_DELAY state and run 2548 * for one more second. 2549 */ 2550 if (syncer_state == SYNCER_SHUTTING_DOWN && 2551 net_worklist_len == 0 && 2552 last_work_seen == syncer_delayno) { 2553 syncer_state = SYNCER_FINAL_DELAY; 2554 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2555 } 2556 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2557 syncer_worklist_len > 0); 2558 2559 /* 2560 * Keep track of the last time there was anything 2561 * on the worklist other than syncer vnodes. 2562 * Return to the SHUTTING_DOWN state if any 2563 * new work appears. 2564 */ 2565 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2566 last_work_seen = syncer_delayno; 2567 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2568 syncer_state = SYNCER_SHUTTING_DOWN; 2569 while (!LIST_EMPTY(slp)) { 2570 error = sync_vnode(slp, &bo, td); 2571 if (error == 1) { 2572 LIST_REMOVE(bo, bo_synclist); 2573 LIST_INSERT_HEAD(next, bo, bo_synclist); 2574 continue; 2575 } 2576 2577 if (first_printf == 0) { 2578 /* 2579 * Drop the sync mutex, because some watchdog 2580 * drivers need to sleep while patting 2581 */ 2582 mtx_unlock(&sync_mtx); 2583 wdog_kern_pat(WD_LASTVAL); 2584 mtx_lock(&sync_mtx); 2585 } 2586 2587 } 2588 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2589 syncer_final_iter--; 2590 /* 2591 * The variable rushjob allows the kernel to speed up the 2592 * processing of the filesystem syncer process. A rushjob 2593 * value of N tells the filesystem syncer to process the next 2594 * N seconds worth of work on its queue ASAP. Currently rushjob 2595 * is used by the soft update code to speed up the filesystem 2596 * syncer process when the incore state is getting so far 2597 * ahead of the disk that the kernel memory pool is being 2598 * threatened with exhaustion. 2599 */ 2600 if (rushjob > 0) { 2601 rushjob -= 1; 2602 continue; 2603 } 2604 /* 2605 * Just sleep for a short period of time between 2606 * iterations when shutting down to allow some I/O 2607 * to happen. 2608 * 2609 * If it has taken us less than a second to process the 2610 * current work, then wait. Otherwise start right over 2611 * again. We can still lose time if any single round 2612 * takes more than two seconds, but it does not really 2613 * matter as we are just trying to generally pace the 2614 * filesystem activity. 2615 */ 2616 if (syncer_state != SYNCER_RUNNING || 2617 time_uptime == starttime) { 2618 thread_lock(td); 2619 sched_prio(td, PPAUSE); 2620 thread_unlock(td); 2621 } 2622 if (syncer_state != SYNCER_RUNNING) 2623 cv_timedwait(&sync_wakeup, &sync_mtx, 2624 hz / SYNCER_SHUTDOWN_SPEEDUP); 2625 else if (time_uptime == starttime) 2626 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2627 } 2628 } 2629 2630 /* 2631 * Request the syncer daemon to speed up its work. 2632 * We never push it to speed up more than half of its 2633 * normal turn time, otherwise it could take over the cpu. 2634 */ 2635 int 2636 speedup_syncer(void) 2637 { 2638 int ret = 0; 2639 2640 mtx_lock(&sync_mtx); 2641 if (rushjob < syncdelay / 2) { 2642 rushjob += 1; 2643 stat_rush_requests += 1; 2644 ret = 1; 2645 } 2646 mtx_unlock(&sync_mtx); 2647 cv_broadcast(&sync_wakeup); 2648 return (ret); 2649 } 2650 2651 /* 2652 * Tell the syncer to speed up its work and run though its work 2653 * list several times, then tell it to shut down. 2654 */ 2655 static void 2656 syncer_shutdown(void *arg, int howto) 2657 { 2658 2659 if (howto & RB_NOSYNC) 2660 return; 2661 mtx_lock(&sync_mtx); 2662 syncer_state = SYNCER_SHUTTING_DOWN; 2663 rushjob = 0; 2664 mtx_unlock(&sync_mtx); 2665 cv_broadcast(&sync_wakeup); 2666 kproc_shutdown(arg, howto); 2667 } 2668 2669 void 2670 syncer_suspend(void) 2671 { 2672 2673 syncer_shutdown(updateproc, 0); 2674 } 2675 2676 void 2677 syncer_resume(void) 2678 { 2679 2680 mtx_lock(&sync_mtx); 2681 first_printf = 1; 2682 syncer_state = SYNCER_RUNNING; 2683 mtx_unlock(&sync_mtx); 2684 cv_broadcast(&sync_wakeup); 2685 kproc_resume(updateproc); 2686 } 2687 2688 /* 2689 * Reassign a buffer from one vnode to another. 2690 * Used to assign file specific control information 2691 * (indirect blocks) to the vnode to which they belong. 2692 */ 2693 void 2694 reassignbuf(struct buf *bp) 2695 { 2696 struct vnode *vp; 2697 struct bufobj *bo; 2698 int delay; 2699 #ifdef INVARIANTS 2700 struct bufv *bv; 2701 #endif 2702 2703 vp = bp->b_vp; 2704 bo = bp->b_bufobj; 2705 ++reassignbufcalls; 2706 2707 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2708 bp, bp->b_vp, bp->b_flags); 2709 /* 2710 * B_PAGING flagged buffers cannot be reassigned because their vp 2711 * is not fully linked in. 2712 */ 2713 if (bp->b_flags & B_PAGING) 2714 panic("cannot reassign paging buffer"); 2715 2716 /* 2717 * Delete from old vnode list, if on one. 2718 */ 2719 BO_LOCK(bo); 2720 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2721 buf_vlist_remove(bp); 2722 else 2723 panic("reassignbuf: Buffer %p not on queue.", bp); 2724 /* 2725 * If dirty, put on list of dirty buffers; otherwise insert onto list 2726 * of clean buffers. 2727 */ 2728 if (bp->b_flags & B_DELWRI) { 2729 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2730 switch (vp->v_type) { 2731 case VDIR: 2732 delay = dirdelay; 2733 break; 2734 case VCHR: 2735 delay = metadelay; 2736 break; 2737 default: 2738 delay = filedelay; 2739 } 2740 vn_syncer_add_to_worklist(bo, delay); 2741 } 2742 buf_vlist_add(bp, bo, BX_VNDIRTY); 2743 } else { 2744 buf_vlist_add(bp, bo, BX_VNCLEAN); 2745 2746 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2747 mtx_lock(&sync_mtx); 2748 LIST_REMOVE(bo, bo_synclist); 2749 syncer_worklist_len--; 2750 mtx_unlock(&sync_mtx); 2751 bo->bo_flag &= ~BO_ONWORKLST; 2752 } 2753 } 2754 #ifdef INVARIANTS 2755 bv = &bo->bo_clean; 2756 bp = TAILQ_FIRST(&bv->bv_hd); 2757 KASSERT(bp == NULL || bp->b_bufobj == bo, 2758 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2759 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2760 KASSERT(bp == NULL || bp->b_bufobj == bo, 2761 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2762 bv = &bo->bo_dirty; 2763 bp = TAILQ_FIRST(&bv->bv_hd); 2764 KASSERT(bp == NULL || bp->b_bufobj == bo, 2765 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2766 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2767 KASSERT(bp == NULL || bp->b_bufobj == bo, 2768 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2769 #endif 2770 BO_UNLOCK(bo); 2771 } 2772 2773 static void 2774 v_init_counters(struct vnode *vp) 2775 { 2776 2777 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2778 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2779 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2780 2781 refcount_init(&vp->v_holdcnt, 1); 2782 refcount_init(&vp->v_usecount, 1); 2783 } 2784 2785 /* 2786 * Increment si_usecount of the associated device, if any. 2787 */ 2788 static void 2789 v_incr_devcount(struct vnode *vp) 2790 { 2791 2792 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2793 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2794 dev_lock(); 2795 vp->v_rdev->si_usecount++; 2796 dev_unlock(); 2797 } 2798 } 2799 2800 /* 2801 * Decrement si_usecount of the associated device, if any. 2802 */ 2803 static void 2804 v_decr_devcount(struct vnode *vp) 2805 { 2806 2807 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2808 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2809 dev_lock(); 2810 vp->v_rdev->si_usecount--; 2811 dev_unlock(); 2812 } 2813 } 2814 2815 /* 2816 * Grab a particular vnode from the free list, increment its 2817 * reference count and lock it. VIRF_DOOMED is set if the vnode 2818 * is being destroyed. Only callers who specify LK_RETRY will 2819 * see doomed vnodes. If inactive processing was delayed in 2820 * vput try to do it here. 2821 * 2822 * usecount is manipulated using atomics without holding any locks. 2823 * 2824 * holdcnt can be manipulated using atomics without holding any locks, 2825 * except when transitioning 1<->0, in which case the interlock is held. 2826 */ 2827 enum vgetstate 2828 vget_prep(struct vnode *vp) 2829 { 2830 enum vgetstate vs; 2831 2832 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2833 vs = VGET_USECOUNT; 2834 } else { 2835 vhold(vp); 2836 vs = VGET_HOLDCNT; 2837 } 2838 return (vs); 2839 } 2840 2841 int 2842 vget(struct vnode *vp, int flags, struct thread *td) 2843 { 2844 enum vgetstate vs; 2845 2846 MPASS(td == curthread); 2847 2848 vs = vget_prep(vp); 2849 return (vget_finish(vp, flags, vs)); 2850 } 2851 2852 static int __noinline 2853 vget_finish_vchr(struct vnode *vp) 2854 { 2855 2856 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2857 2858 /* 2859 * See the comment in vget_finish before usecount bump. 2860 */ 2861 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2862 #ifdef INVARIANTS 2863 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2864 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 2865 #else 2866 refcount_release(&vp->v_holdcnt); 2867 #endif 2868 return (0); 2869 } 2870 2871 VI_LOCK(vp); 2872 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2873 #ifdef INVARIANTS 2874 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2875 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2876 #else 2877 refcount_release(&vp->v_holdcnt); 2878 #endif 2879 VI_UNLOCK(vp); 2880 return (0); 2881 } 2882 v_incr_devcount(vp); 2883 refcount_acquire(&vp->v_usecount); 2884 VI_UNLOCK(vp); 2885 return (0); 2886 } 2887 2888 int 2889 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2890 { 2891 int error, old; 2892 2893 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2894 ("%s: invalid lock operation", __func__)); 2895 2896 if ((flags & LK_INTERLOCK) != 0) 2897 ASSERT_VI_LOCKED(vp, __func__); 2898 else 2899 ASSERT_VI_UNLOCKED(vp, __func__); 2900 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 2901 if (vs == VGET_USECOUNT) { 2902 VNASSERT(vp->v_usecount > 0, vp, 2903 ("%s: vnode without usecount when VGET_USECOUNT was passed", 2904 __func__)); 2905 } 2906 2907 error = vn_lock(vp, flags); 2908 if (__predict_false(error != 0)) { 2909 if (vs == VGET_USECOUNT) 2910 vrele(vp); 2911 else 2912 vdrop(vp); 2913 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2914 vp); 2915 return (error); 2916 } 2917 2918 if (vs == VGET_USECOUNT) { 2919 return (0); 2920 } 2921 2922 if (__predict_false(vp->v_type == VCHR)) 2923 return (vget_finish_vchr(vp)); 2924 2925 /* 2926 * We hold the vnode. If the usecount is 0 it will be utilized to keep 2927 * the vnode around. Otherwise someone else lended their hold count and 2928 * we have to drop ours. 2929 */ 2930 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2931 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 2932 if (old != 0) { 2933 #ifdef INVARIANTS 2934 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2935 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2936 #else 2937 refcount_release(&vp->v_holdcnt); 2938 #endif 2939 } 2940 return (0); 2941 } 2942 2943 /* 2944 * Increase the reference (use) and hold count of a vnode. 2945 * This will also remove the vnode from the free list if it is presently free. 2946 */ 2947 static void __noinline 2948 vref_vchr(struct vnode *vp, bool interlock) 2949 { 2950 2951 /* 2952 * See the comment in vget_finish before usecount bump. 2953 */ 2954 if (!interlock) { 2955 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2956 VNODE_REFCOUNT_FENCE_ACQ(); 2957 VNASSERT(vp->v_holdcnt > 0, vp, 2958 ("%s: active vnode not held", __func__)); 2959 return; 2960 } 2961 VI_LOCK(vp); 2962 /* 2963 * By the time we get here the vnode might have been doomed, at 2964 * which point the 0->1 use count transition is no longer 2965 * protected by the interlock. Since it can't bounce back to 2966 * VCHR and requires vref semantics, punt it back 2967 */ 2968 if (__predict_false(vp->v_type == VBAD)) { 2969 VI_UNLOCK(vp); 2970 vref(vp); 2971 return; 2972 } 2973 } 2974 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2975 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2976 VNODE_REFCOUNT_FENCE_ACQ(); 2977 VNASSERT(vp->v_holdcnt > 0, vp, 2978 ("%s: active vnode not held", __func__)); 2979 if (!interlock) 2980 VI_UNLOCK(vp); 2981 return; 2982 } 2983 vhold(vp); 2984 v_incr_devcount(vp); 2985 refcount_acquire(&vp->v_usecount); 2986 if (!interlock) 2987 VI_UNLOCK(vp); 2988 return; 2989 } 2990 2991 void 2992 vref(struct vnode *vp) 2993 { 2994 int old; 2995 2996 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2997 if (__predict_false(vp->v_type == VCHR)) { 2998 vref_vchr(vp, false); 2999 return; 3000 } 3001 3002 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3003 VNODE_REFCOUNT_FENCE_ACQ(); 3004 VNASSERT(vp->v_holdcnt > 0, vp, 3005 ("%s: active vnode not held", __func__)); 3006 return; 3007 } 3008 vhold(vp); 3009 /* 3010 * See the comment in vget_finish. 3011 */ 3012 old = atomic_fetchadd_int(&vp->v_usecount, 1); 3013 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 3014 if (old != 0) { 3015 #ifdef INVARIANTS 3016 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 3017 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 3018 #else 3019 refcount_release(&vp->v_holdcnt); 3020 #endif 3021 } 3022 } 3023 3024 void 3025 vrefl(struct vnode *vp) 3026 { 3027 3028 ASSERT_VI_LOCKED(vp, __func__); 3029 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3030 if (__predict_false(vp->v_type == VCHR)) { 3031 vref_vchr(vp, true); 3032 return; 3033 } 3034 vref(vp); 3035 } 3036 3037 void 3038 vrefact(struct vnode *vp) 3039 { 3040 3041 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3042 #ifdef INVARIANTS 3043 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 3044 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3045 #else 3046 refcount_acquire(&vp->v_usecount); 3047 #endif 3048 } 3049 3050 /* 3051 * Return reference count of a vnode. 3052 * 3053 * The results of this call are only guaranteed when some mechanism is used to 3054 * stop other processes from gaining references to the vnode. This may be the 3055 * case if the caller holds the only reference. This is also useful when stale 3056 * data is acceptable as race conditions may be accounted for by some other 3057 * means. 3058 */ 3059 int 3060 vrefcnt(struct vnode *vp) 3061 { 3062 3063 return (vp->v_usecount); 3064 } 3065 3066 void 3067 vlazy(struct vnode *vp) 3068 { 3069 struct mount *mp; 3070 3071 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 3072 3073 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 3074 return; 3075 /* 3076 * We may get here for inactive routines after the vnode got doomed. 3077 */ 3078 if (VN_IS_DOOMED(vp)) 3079 return; 3080 mp = vp->v_mount; 3081 mtx_lock(&mp->mnt_listmtx); 3082 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 3083 vp->v_mflag |= VMP_LAZYLIST; 3084 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3085 mp->mnt_lazyvnodelistsize++; 3086 } 3087 mtx_unlock(&mp->mnt_listmtx); 3088 } 3089 3090 /* 3091 * This routine is only meant to be called from vgonel prior to dooming 3092 * the vnode. 3093 */ 3094 static void 3095 vunlazy_gone(struct vnode *vp) 3096 { 3097 struct mount *mp; 3098 3099 ASSERT_VOP_ELOCKED(vp, __func__); 3100 ASSERT_VI_LOCKED(vp, __func__); 3101 VNPASS(!VN_IS_DOOMED(vp), vp); 3102 3103 if (vp->v_mflag & VMP_LAZYLIST) { 3104 mp = vp->v_mount; 3105 mtx_lock(&mp->mnt_listmtx); 3106 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3107 vp->v_mflag &= ~VMP_LAZYLIST; 3108 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3109 mp->mnt_lazyvnodelistsize--; 3110 mtx_unlock(&mp->mnt_listmtx); 3111 } 3112 } 3113 3114 static void 3115 vdefer_inactive(struct vnode *vp) 3116 { 3117 3118 ASSERT_VI_LOCKED(vp, __func__); 3119 VNASSERT(vp->v_holdcnt > 0, vp, 3120 ("%s: vnode without hold count", __func__)); 3121 if (VN_IS_DOOMED(vp)) { 3122 vdropl(vp); 3123 return; 3124 } 3125 if (vp->v_iflag & VI_DEFINACT) { 3126 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3127 vdropl(vp); 3128 return; 3129 } 3130 if (vp->v_usecount > 0) { 3131 vp->v_iflag &= ~VI_OWEINACT; 3132 vdropl(vp); 3133 return; 3134 } 3135 vlazy(vp); 3136 vp->v_iflag |= VI_DEFINACT; 3137 VI_UNLOCK(vp); 3138 counter_u64_add(deferred_inact, 1); 3139 } 3140 3141 static void 3142 vdefer_inactive_unlocked(struct vnode *vp) 3143 { 3144 3145 VI_LOCK(vp); 3146 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3147 vdropl(vp); 3148 return; 3149 } 3150 vdefer_inactive(vp); 3151 } 3152 3153 enum vputx_op { VPUTX_VRELE, VPUTX_VPUT, VPUTX_VUNREF }; 3154 3155 /* 3156 * Decrement the use and hold counts for a vnode. 3157 * 3158 * See an explanation near vget() as to why atomic operation is safe. 3159 * 3160 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3161 * on the lock being held all the way until VOP_INACTIVE. This in particular 3162 * happens with UFS which adds half-constructed vnodes to the hash, where they 3163 * can be found by other code. 3164 */ 3165 static void 3166 vputx(struct vnode *vp, enum vputx_op func) 3167 { 3168 int error; 3169 3170 KASSERT(vp != NULL, ("vputx: null vp")); 3171 if (func == VPUTX_VUNREF) 3172 ASSERT_VOP_LOCKED(vp, "vunref"); 3173 else if (func == VPUTX_VPUT) 3174 ASSERT_VOP_LOCKED(vp, "vput"); 3175 ASSERT_VI_UNLOCKED(vp, __func__); 3176 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 3177 ("%s: wrong ref counts", __func__)); 3178 3179 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3180 3181 /* 3182 * We want to hold the vnode until the inactive finishes to 3183 * prevent vgone() races. We drop the use count here and the 3184 * hold count below when we're done. 3185 * 3186 * If we release the last usecount we take ownership of the hold 3187 * count which provides liveness of the vnode, in which case we 3188 * have to vdrop. 3189 */ 3190 if (!refcount_release(&vp->v_usecount)) { 3191 if (func == VPUTX_VPUT) 3192 VOP_UNLOCK(vp); 3193 return; 3194 } 3195 VI_LOCK(vp); 3196 v_decr_devcount(vp); 3197 /* 3198 * By the time we got here someone else might have transitioned 3199 * the count back to > 0. 3200 */ 3201 if (vp->v_usecount > 0 || vp->v_iflag & VI_DOINGINACT) 3202 goto out; 3203 3204 /* 3205 * Check if the fs wants to perform inactive processing. Note we 3206 * may be only holding the interlock, in which case it is possible 3207 * someone else called vgone on the vnode and ->v_data is now NULL. 3208 * Since vgone performs inactive on its own there is nothing to do 3209 * here but to drop our hold count. 3210 */ 3211 if (__predict_false(VN_IS_DOOMED(vp)) || 3212 VOP_NEED_INACTIVE(vp) == 0) 3213 goto out; 3214 3215 /* 3216 * We must call VOP_INACTIVE with the node locked. Mark 3217 * as VI_DOINGINACT to avoid recursion. 3218 */ 3219 vp->v_iflag |= VI_OWEINACT; 3220 switch (func) { 3221 case VPUTX_VRELE: 3222 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3223 VI_LOCK(vp); 3224 break; 3225 case VPUTX_VPUT: 3226 error = 0; 3227 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3228 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3229 LK_NOWAIT); 3230 VI_LOCK(vp); 3231 } 3232 break; 3233 case VPUTX_VUNREF: 3234 error = 0; 3235 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3236 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3237 VI_LOCK(vp); 3238 } 3239 break; 3240 } 3241 if (error == 0) { 3242 vinactive(vp); 3243 if (func != VPUTX_VUNREF) 3244 VOP_UNLOCK(vp); 3245 vdropl(vp); 3246 } else { 3247 vdefer_inactive(vp); 3248 } 3249 return; 3250 out: 3251 if (func == VPUTX_VPUT) 3252 VOP_UNLOCK(vp); 3253 vdropl(vp); 3254 } 3255 3256 /* 3257 * Vnode put/release. 3258 * If count drops to zero, call inactive routine and return to freelist. 3259 */ 3260 void 3261 vrele(struct vnode *vp) 3262 { 3263 3264 vputx(vp, VPUTX_VRELE); 3265 } 3266 3267 /* 3268 * Release an already locked vnode. This give the same effects as 3269 * unlock+vrele(), but takes less time and avoids releasing and 3270 * re-aquiring the lock (as vrele() acquires the lock internally.) 3271 */ 3272 void 3273 vput(struct vnode *vp) 3274 { 3275 3276 vputx(vp, VPUTX_VPUT); 3277 } 3278 3279 /* 3280 * Release an exclusively locked vnode. Do not unlock the vnode lock. 3281 */ 3282 void 3283 vunref(struct vnode *vp) 3284 { 3285 3286 vputx(vp, VPUTX_VUNREF); 3287 } 3288 3289 void 3290 vhold(struct vnode *vp) 3291 { 3292 struct vdbatch *vd; 3293 int old; 3294 3295 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3296 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3297 VNASSERT(old >= 0, vp, ("%s: wrong hold count %d", __func__, old)); 3298 if (old != 0) 3299 return; 3300 critical_enter(); 3301 vd = DPCPU_PTR(vd); 3302 vd->freevnodes--; 3303 critical_exit(); 3304 } 3305 3306 void 3307 vholdl(struct vnode *vp) 3308 { 3309 3310 ASSERT_VI_LOCKED(vp, __func__); 3311 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3312 vhold(vp); 3313 } 3314 3315 void 3316 vholdnz(struct vnode *vp) 3317 { 3318 3319 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3320 #ifdef INVARIANTS 3321 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3322 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 3323 #else 3324 atomic_add_int(&vp->v_holdcnt, 1); 3325 #endif 3326 } 3327 3328 static void __noinline 3329 vdbatch_process(struct vdbatch *vd) 3330 { 3331 struct vnode *vp; 3332 int i; 3333 3334 mtx_assert(&vd->lock, MA_OWNED); 3335 MPASS(curthread->td_pinned > 0); 3336 MPASS(vd->index == VDBATCH_SIZE); 3337 3338 mtx_lock(&vnode_list_mtx); 3339 critical_enter(); 3340 freevnodes += vd->freevnodes; 3341 for (i = 0; i < VDBATCH_SIZE; i++) { 3342 vp = vd->tab[i]; 3343 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3344 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3345 MPASS(vp->v_dbatchcpu != NOCPU); 3346 vp->v_dbatchcpu = NOCPU; 3347 } 3348 mtx_unlock(&vnode_list_mtx); 3349 vd->freevnodes = 0; 3350 bzero(vd->tab, sizeof(vd->tab)); 3351 vd->index = 0; 3352 critical_exit(); 3353 } 3354 3355 static void 3356 vdbatch_enqueue(struct vnode *vp) 3357 { 3358 struct vdbatch *vd; 3359 3360 ASSERT_VI_LOCKED(vp, __func__); 3361 VNASSERT(!VN_IS_DOOMED(vp), vp, 3362 ("%s: deferring requeue of a doomed vnode", __func__)); 3363 3364 critical_enter(); 3365 vd = DPCPU_PTR(vd); 3366 vd->freevnodes++; 3367 if (vp->v_dbatchcpu != NOCPU) { 3368 VI_UNLOCK(vp); 3369 critical_exit(); 3370 return; 3371 } 3372 3373 sched_pin(); 3374 critical_exit(); 3375 mtx_lock(&vd->lock); 3376 MPASS(vd->index < VDBATCH_SIZE); 3377 MPASS(vd->tab[vd->index] == NULL); 3378 /* 3379 * A hack: we depend on being pinned so that we know what to put in 3380 * ->v_dbatchcpu. 3381 */ 3382 vp->v_dbatchcpu = curcpu; 3383 vd->tab[vd->index] = vp; 3384 vd->index++; 3385 VI_UNLOCK(vp); 3386 if (vd->index == VDBATCH_SIZE) 3387 vdbatch_process(vd); 3388 mtx_unlock(&vd->lock); 3389 sched_unpin(); 3390 } 3391 3392 /* 3393 * This routine must only be called for vnodes which are about to be 3394 * deallocated. Supporting dequeue for arbitrary vndoes would require 3395 * validating that the locked batch matches. 3396 */ 3397 static void 3398 vdbatch_dequeue(struct vnode *vp) 3399 { 3400 struct vdbatch *vd; 3401 int i; 3402 short cpu; 3403 3404 VNASSERT(vp->v_type == VBAD || vp->v_type == VNON, vp, 3405 ("%s: called for a used vnode\n", __func__)); 3406 3407 cpu = vp->v_dbatchcpu; 3408 if (cpu == NOCPU) 3409 return; 3410 3411 vd = DPCPU_ID_PTR(cpu, vd); 3412 mtx_lock(&vd->lock); 3413 for (i = 0; i < vd->index; i++) { 3414 if (vd->tab[i] != vp) 3415 continue; 3416 vp->v_dbatchcpu = NOCPU; 3417 vd->index--; 3418 vd->tab[i] = vd->tab[vd->index]; 3419 vd->tab[vd->index] = NULL; 3420 break; 3421 } 3422 mtx_unlock(&vd->lock); 3423 /* 3424 * Either we dequeued the vnode above or the target CPU beat us to it. 3425 */ 3426 MPASS(vp->v_dbatchcpu == NOCPU); 3427 } 3428 3429 /* 3430 * Drop the hold count of the vnode. If this is the last reference to 3431 * the vnode we place it on the free list unless it has been vgone'd 3432 * (marked VIRF_DOOMED) in which case we will free it. 3433 * 3434 * Because the vnode vm object keeps a hold reference on the vnode if 3435 * there is at least one resident non-cached page, the vnode cannot 3436 * leave the active list without the page cleanup done. 3437 */ 3438 static void 3439 vdrop_deactivate(struct vnode *vp) 3440 { 3441 struct mount *mp; 3442 3443 ASSERT_VI_LOCKED(vp, __func__); 3444 /* 3445 * Mark a vnode as free: remove it from its active list 3446 * and put it up for recycling on the freelist. 3447 */ 3448 VNASSERT(!VN_IS_DOOMED(vp), vp, 3449 ("vdrop: returning doomed vnode")); 3450 VNASSERT(vp->v_op != NULL, vp, 3451 ("vdrop: vnode already reclaimed.")); 3452 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 3453 ("vnode with VI_OWEINACT set")); 3454 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, 3455 ("vnode with VI_DEFINACT set")); 3456 if (vp->v_mflag & VMP_LAZYLIST) { 3457 mp = vp->v_mount; 3458 mtx_lock(&mp->mnt_listmtx); 3459 VNASSERT(vp->v_mflag & VMP_LAZYLIST, vp, ("lost VMP_LAZYLIST")); 3460 /* 3461 * Don't remove the vnode from the lazy list if another thread 3462 * has increased the hold count. It may have re-enqueued the 3463 * vnode to the lazy list and is now responsible for its 3464 * removal. 3465 */ 3466 if (vp->v_holdcnt == 0) { 3467 vp->v_mflag &= ~VMP_LAZYLIST; 3468 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3469 mp->mnt_lazyvnodelistsize--; 3470 } 3471 mtx_unlock(&mp->mnt_listmtx); 3472 } 3473 vdbatch_enqueue(vp); 3474 } 3475 3476 void 3477 vdrop(struct vnode *vp) 3478 { 3479 3480 ASSERT_VI_UNLOCKED(vp, __func__); 3481 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3482 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3483 return; 3484 VI_LOCK(vp); 3485 vdropl(vp); 3486 } 3487 3488 void 3489 vdropl(struct vnode *vp) 3490 { 3491 3492 ASSERT_VI_LOCKED(vp, __func__); 3493 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3494 if (!refcount_release(&vp->v_holdcnt)) { 3495 VI_UNLOCK(vp); 3496 return; 3497 } 3498 if (VN_IS_DOOMED(vp)) { 3499 freevnode(vp); 3500 return; 3501 } 3502 vdrop_deactivate(vp); 3503 } 3504 3505 /* 3506 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3507 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3508 */ 3509 static void 3510 vinactivef(struct vnode *vp) 3511 { 3512 struct vm_object *obj; 3513 3514 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3515 ASSERT_VI_LOCKED(vp, "vinactive"); 3516 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3517 ("vinactive: recursed on VI_DOINGINACT")); 3518 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3519 vp->v_iflag |= VI_DOINGINACT; 3520 vp->v_iflag &= ~VI_OWEINACT; 3521 VI_UNLOCK(vp); 3522 /* 3523 * Before moving off the active list, we must be sure that any 3524 * modified pages are converted into the vnode's dirty 3525 * buffers, since these will no longer be checked once the 3526 * vnode is on the inactive list. 3527 * 3528 * The write-out of the dirty pages is asynchronous. At the 3529 * point that VOP_INACTIVE() is called, there could still be 3530 * pending I/O and dirty pages in the object. 3531 */ 3532 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3533 vm_object_mightbedirty(obj)) { 3534 VM_OBJECT_WLOCK(obj); 3535 vm_object_page_clean(obj, 0, 0, 0); 3536 VM_OBJECT_WUNLOCK(obj); 3537 } 3538 VOP_INACTIVE(vp, curthread); 3539 VI_LOCK(vp); 3540 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3541 ("vinactive: lost VI_DOINGINACT")); 3542 vp->v_iflag &= ~VI_DOINGINACT; 3543 } 3544 3545 void 3546 vinactive(struct vnode *vp) 3547 { 3548 3549 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3550 ASSERT_VI_LOCKED(vp, "vinactive"); 3551 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3552 3553 if ((vp->v_iflag & VI_OWEINACT) == 0) 3554 return; 3555 if (vp->v_iflag & VI_DOINGINACT) 3556 return; 3557 if (vp->v_usecount > 0) { 3558 vp->v_iflag &= ~VI_OWEINACT; 3559 return; 3560 } 3561 vinactivef(vp); 3562 } 3563 3564 /* 3565 * Remove any vnodes in the vnode table belonging to mount point mp. 3566 * 3567 * If FORCECLOSE is not specified, there should not be any active ones, 3568 * return error if any are found (nb: this is a user error, not a 3569 * system error). If FORCECLOSE is specified, detach any active vnodes 3570 * that are found. 3571 * 3572 * If WRITECLOSE is set, only flush out regular file vnodes open for 3573 * writing. 3574 * 3575 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3576 * 3577 * `rootrefs' specifies the base reference count for the root vnode 3578 * of this filesystem. The root vnode is considered busy if its 3579 * v_usecount exceeds this value. On a successful return, vflush(, td) 3580 * will call vrele() on the root vnode exactly rootrefs times. 3581 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3582 * be zero. 3583 */ 3584 #ifdef DIAGNOSTIC 3585 static int busyprt = 0; /* print out busy vnodes */ 3586 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3587 #endif 3588 3589 int 3590 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3591 { 3592 struct vnode *vp, *mvp, *rootvp = NULL; 3593 struct vattr vattr; 3594 int busy = 0, error; 3595 3596 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3597 rootrefs, flags); 3598 if (rootrefs > 0) { 3599 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3600 ("vflush: bad args")); 3601 /* 3602 * Get the filesystem root vnode. We can vput() it 3603 * immediately, since with rootrefs > 0, it won't go away. 3604 */ 3605 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3606 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3607 __func__, error); 3608 return (error); 3609 } 3610 vput(rootvp); 3611 } 3612 loop: 3613 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3614 vholdl(vp); 3615 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3616 if (error) { 3617 vdrop(vp); 3618 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3619 goto loop; 3620 } 3621 /* 3622 * Skip over a vnodes marked VV_SYSTEM. 3623 */ 3624 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3625 VOP_UNLOCK(vp); 3626 vdrop(vp); 3627 continue; 3628 } 3629 /* 3630 * If WRITECLOSE is set, flush out unlinked but still open 3631 * files (even if open only for reading) and regular file 3632 * vnodes open for writing. 3633 */ 3634 if (flags & WRITECLOSE) { 3635 if (vp->v_object != NULL) { 3636 VM_OBJECT_WLOCK(vp->v_object); 3637 vm_object_page_clean(vp->v_object, 0, 0, 0); 3638 VM_OBJECT_WUNLOCK(vp->v_object); 3639 } 3640 error = VOP_FSYNC(vp, MNT_WAIT, td); 3641 if (error != 0) { 3642 VOP_UNLOCK(vp); 3643 vdrop(vp); 3644 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3645 return (error); 3646 } 3647 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3648 VI_LOCK(vp); 3649 3650 if ((vp->v_type == VNON || 3651 (error == 0 && vattr.va_nlink > 0)) && 3652 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3653 VOP_UNLOCK(vp); 3654 vdropl(vp); 3655 continue; 3656 } 3657 } else 3658 VI_LOCK(vp); 3659 /* 3660 * With v_usecount == 0, all we need to do is clear out the 3661 * vnode data structures and we are done. 3662 * 3663 * If FORCECLOSE is set, forcibly close the vnode. 3664 */ 3665 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3666 vgonel(vp); 3667 } else { 3668 busy++; 3669 #ifdef DIAGNOSTIC 3670 if (busyprt) 3671 vn_printf(vp, "vflush: busy vnode "); 3672 #endif 3673 } 3674 VOP_UNLOCK(vp); 3675 vdropl(vp); 3676 } 3677 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3678 /* 3679 * If just the root vnode is busy, and if its refcount 3680 * is equal to `rootrefs', then go ahead and kill it. 3681 */ 3682 VI_LOCK(rootvp); 3683 KASSERT(busy > 0, ("vflush: not busy")); 3684 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3685 ("vflush: usecount %d < rootrefs %d", 3686 rootvp->v_usecount, rootrefs)); 3687 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3688 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3689 vgone(rootvp); 3690 VOP_UNLOCK(rootvp); 3691 busy = 0; 3692 } else 3693 VI_UNLOCK(rootvp); 3694 } 3695 if (busy) { 3696 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3697 busy); 3698 return (EBUSY); 3699 } 3700 for (; rootrefs > 0; rootrefs--) 3701 vrele(rootvp); 3702 return (0); 3703 } 3704 3705 /* 3706 * Recycle an unused vnode to the front of the free list. 3707 */ 3708 int 3709 vrecycle(struct vnode *vp) 3710 { 3711 int recycled; 3712 3713 VI_LOCK(vp); 3714 recycled = vrecyclel(vp); 3715 VI_UNLOCK(vp); 3716 return (recycled); 3717 } 3718 3719 /* 3720 * vrecycle, with the vp interlock held. 3721 */ 3722 int 3723 vrecyclel(struct vnode *vp) 3724 { 3725 int recycled; 3726 3727 ASSERT_VOP_ELOCKED(vp, __func__); 3728 ASSERT_VI_LOCKED(vp, __func__); 3729 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3730 recycled = 0; 3731 if (vp->v_usecount == 0) { 3732 recycled = 1; 3733 vgonel(vp); 3734 } 3735 return (recycled); 3736 } 3737 3738 /* 3739 * Eliminate all activity associated with a vnode 3740 * in preparation for reuse. 3741 */ 3742 void 3743 vgone(struct vnode *vp) 3744 { 3745 VI_LOCK(vp); 3746 vgonel(vp); 3747 VI_UNLOCK(vp); 3748 } 3749 3750 static void 3751 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3752 struct vnode *lowervp __unused) 3753 { 3754 } 3755 3756 /* 3757 * Notify upper mounts about reclaimed or unlinked vnode. 3758 */ 3759 void 3760 vfs_notify_upper(struct vnode *vp, int event) 3761 { 3762 static struct vfsops vgonel_vfsops = { 3763 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3764 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3765 }; 3766 struct mount *mp, *ump, *mmp; 3767 3768 mp = vp->v_mount; 3769 if (mp == NULL) 3770 return; 3771 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3772 return; 3773 3774 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3775 mmp->mnt_op = &vgonel_vfsops; 3776 mmp->mnt_kern_flag |= MNTK_MARKER; 3777 MNT_ILOCK(mp); 3778 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3779 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3780 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3781 ump = TAILQ_NEXT(ump, mnt_upper_link); 3782 continue; 3783 } 3784 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3785 MNT_IUNLOCK(mp); 3786 switch (event) { 3787 case VFS_NOTIFY_UPPER_RECLAIM: 3788 VFS_RECLAIM_LOWERVP(ump, vp); 3789 break; 3790 case VFS_NOTIFY_UPPER_UNLINK: 3791 VFS_UNLINK_LOWERVP(ump, vp); 3792 break; 3793 default: 3794 KASSERT(0, ("invalid event %d", event)); 3795 break; 3796 } 3797 MNT_ILOCK(mp); 3798 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3799 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3800 } 3801 free(mmp, M_TEMP); 3802 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3803 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3804 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3805 wakeup(&mp->mnt_uppers); 3806 } 3807 MNT_IUNLOCK(mp); 3808 } 3809 3810 /* 3811 * vgone, with the vp interlock held. 3812 */ 3813 static void 3814 vgonel(struct vnode *vp) 3815 { 3816 struct thread *td; 3817 struct mount *mp; 3818 vm_object_t object; 3819 bool active, oweinact; 3820 3821 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3822 ASSERT_VI_LOCKED(vp, "vgonel"); 3823 VNASSERT(vp->v_holdcnt, vp, 3824 ("vgonel: vp %p has no reference.", vp)); 3825 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3826 td = curthread; 3827 3828 /* 3829 * Don't vgonel if we're already doomed. 3830 */ 3831 if (vp->v_irflag & VIRF_DOOMED) 3832 return; 3833 vunlazy_gone(vp); 3834 vp->v_irflag |= VIRF_DOOMED; 3835 3836 /* 3837 * Check to see if the vnode is in use. If so, we have to call 3838 * VOP_CLOSE() and VOP_INACTIVE(). 3839 */ 3840 active = vp->v_usecount > 0; 3841 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 3842 /* 3843 * If we need to do inactive VI_OWEINACT will be set. 3844 */ 3845 if (vp->v_iflag & VI_DEFINACT) { 3846 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3847 vp->v_iflag &= ~VI_DEFINACT; 3848 vdropl(vp); 3849 } else { 3850 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 3851 VI_UNLOCK(vp); 3852 } 3853 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3854 3855 /* 3856 * If purging an active vnode, it must be closed and 3857 * deactivated before being reclaimed. 3858 */ 3859 if (active) 3860 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3861 if (oweinact || active) { 3862 VI_LOCK(vp); 3863 vinactivef(vp); 3864 VI_UNLOCK(vp); 3865 } 3866 VNPASS(!vn_need_pageq_flush(vp), vp); 3867 if (vp->v_type == VSOCK) 3868 vfs_unp_reclaim(vp); 3869 3870 /* 3871 * Clean out any buffers associated with the vnode. 3872 * If the flush fails, just toss the buffers. 3873 */ 3874 mp = NULL; 3875 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3876 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3877 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3878 while (vinvalbuf(vp, 0, 0, 0) != 0) 3879 ; 3880 } 3881 3882 BO_LOCK(&vp->v_bufobj); 3883 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3884 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3885 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3886 vp->v_bufobj.bo_clean.bv_cnt == 0, 3887 ("vp %p bufobj not invalidated", vp)); 3888 3889 /* 3890 * For VMIO bufobj, BO_DEAD is set later, or in 3891 * vm_object_terminate() after the object's page queue is 3892 * flushed. 3893 */ 3894 object = vp->v_bufobj.bo_object; 3895 if (object == NULL) 3896 vp->v_bufobj.bo_flag |= BO_DEAD; 3897 BO_UNLOCK(&vp->v_bufobj); 3898 3899 /* 3900 * Handle the VM part. Tmpfs handles v_object on its own (the 3901 * OBJT_VNODE check). Nullfs or other bypassing filesystems 3902 * should not touch the object borrowed from the lower vnode 3903 * (the handle check). 3904 */ 3905 if (object != NULL && object->type == OBJT_VNODE && 3906 object->handle == vp) 3907 vnode_destroy_vobject(vp); 3908 3909 /* 3910 * Reclaim the vnode. 3911 */ 3912 if (VOP_RECLAIM(vp, td)) 3913 panic("vgone: cannot reclaim"); 3914 if (mp != NULL) 3915 vn_finished_secondary_write(mp); 3916 VNASSERT(vp->v_object == NULL, vp, 3917 ("vop_reclaim left v_object vp=%p", vp)); 3918 /* 3919 * Clear the advisory locks and wake up waiting threads. 3920 */ 3921 (void)VOP_ADVLOCKPURGE(vp); 3922 vp->v_lockf = NULL; 3923 /* 3924 * Delete from old mount point vnode list. 3925 */ 3926 delmntque(vp); 3927 cache_purge(vp); 3928 /* 3929 * Done with purge, reset to the standard lock and invalidate 3930 * the vnode. 3931 */ 3932 VI_LOCK(vp); 3933 vp->v_vnlock = &vp->v_lock; 3934 vp->v_op = &dead_vnodeops; 3935 vp->v_type = VBAD; 3936 } 3937 3938 /* 3939 * Calculate the total number of references to a special device. 3940 */ 3941 int 3942 vcount(struct vnode *vp) 3943 { 3944 int count; 3945 3946 dev_lock(); 3947 count = vp->v_rdev->si_usecount; 3948 dev_unlock(); 3949 return (count); 3950 } 3951 3952 /* 3953 * Print out a description of a vnode. 3954 */ 3955 static char *typename[] = 3956 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3957 "VMARKER"}; 3958 3959 void 3960 vn_printf(struct vnode *vp, const char *fmt, ...) 3961 { 3962 va_list ap; 3963 char buf[256], buf2[16]; 3964 u_long flags; 3965 3966 va_start(ap, fmt); 3967 vprintf(fmt, ap); 3968 va_end(ap); 3969 printf("%p: ", (void *)vp); 3970 printf("type %s\n", typename[vp->v_type]); 3971 printf(" usecount %d, writecount %d, refcount %d", 3972 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 3973 switch (vp->v_type) { 3974 case VDIR: 3975 printf(" mountedhere %p\n", vp->v_mountedhere); 3976 break; 3977 case VCHR: 3978 printf(" rdev %p\n", vp->v_rdev); 3979 break; 3980 case VSOCK: 3981 printf(" socket %p\n", vp->v_unpcb); 3982 break; 3983 case VFIFO: 3984 printf(" fifoinfo %p\n", vp->v_fifoinfo); 3985 break; 3986 default: 3987 printf("\n"); 3988 break; 3989 } 3990 buf[0] = '\0'; 3991 buf[1] = '\0'; 3992 if (vp->v_irflag & VIRF_DOOMED) 3993 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 3994 flags = vp->v_irflag & ~(VIRF_DOOMED); 3995 if (flags != 0) { 3996 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 3997 strlcat(buf, buf2, sizeof(buf)); 3998 } 3999 if (vp->v_vflag & VV_ROOT) 4000 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4001 if (vp->v_vflag & VV_ISTTY) 4002 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4003 if (vp->v_vflag & VV_NOSYNC) 4004 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4005 if (vp->v_vflag & VV_ETERNALDEV) 4006 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4007 if (vp->v_vflag & VV_CACHEDLABEL) 4008 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4009 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4010 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4011 if (vp->v_vflag & VV_COPYONWRITE) 4012 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4013 if (vp->v_vflag & VV_SYSTEM) 4014 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4015 if (vp->v_vflag & VV_PROCDEP) 4016 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4017 if (vp->v_vflag & VV_NOKNOTE) 4018 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 4019 if (vp->v_vflag & VV_DELETED) 4020 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4021 if (vp->v_vflag & VV_MD) 4022 strlcat(buf, "|VV_MD", sizeof(buf)); 4023 if (vp->v_vflag & VV_FORCEINSMQ) 4024 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4025 if (vp->v_vflag & VV_READLINK) 4026 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4027 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4028 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 4029 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 4030 if (flags != 0) { 4031 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4032 strlcat(buf, buf2, sizeof(buf)); 4033 } 4034 if (vp->v_iflag & VI_TEXT_REF) 4035 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 4036 if (vp->v_iflag & VI_MOUNT) 4037 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4038 if (vp->v_iflag & VI_DOINGINACT) 4039 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4040 if (vp->v_iflag & VI_OWEINACT) 4041 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4042 if (vp->v_iflag & VI_DEFINACT) 4043 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4044 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | 4045 VI_OWEINACT | VI_DEFINACT); 4046 if (flags != 0) { 4047 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4048 strlcat(buf, buf2, sizeof(buf)); 4049 } 4050 if (vp->v_mflag & VMP_LAZYLIST) 4051 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4052 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4053 if (flags != 0) { 4054 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4055 strlcat(buf, buf2, sizeof(buf)); 4056 } 4057 printf(" flags (%s)\n", buf + 1); 4058 if (mtx_owned(VI_MTX(vp))) 4059 printf(" VI_LOCKed"); 4060 if (vp->v_object != NULL) 4061 printf(" v_object %p ref %d pages %d " 4062 "cleanbuf %d dirtybuf %d\n", 4063 vp->v_object, vp->v_object->ref_count, 4064 vp->v_object->resident_page_count, 4065 vp->v_bufobj.bo_clean.bv_cnt, 4066 vp->v_bufobj.bo_dirty.bv_cnt); 4067 printf(" "); 4068 lockmgr_printinfo(vp->v_vnlock); 4069 if (vp->v_data != NULL) 4070 VOP_PRINT(vp); 4071 } 4072 4073 #ifdef DDB 4074 /* 4075 * List all of the locked vnodes in the system. 4076 * Called when debugging the kernel. 4077 */ 4078 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 4079 { 4080 struct mount *mp; 4081 struct vnode *vp; 4082 4083 /* 4084 * Note: because this is DDB, we can't obey the locking semantics 4085 * for these structures, which means we could catch an inconsistent 4086 * state and dereference a nasty pointer. Not much to be done 4087 * about that. 4088 */ 4089 db_printf("Locked vnodes\n"); 4090 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4091 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4092 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4093 vn_printf(vp, "vnode "); 4094 } 4095 } 4096 } 4097 4098 /* 4099 * Show details about the given vnode. 4100 */ 4101 DB_SHOW_COMMAND(vnode, db_show_vnode) 4102 { 4103 struct vnode *vp; 4104 4105 if (!have_addr) 4106 return; 4107 vp = (struct vnode *)addr; 4108 vn_printf(vp, "vnode "); 4109 } 4110 4111 /* 4112 * Show details about the given mount point. 4113 */ 4114 DB_SHOW_COMMAND(mount, db_show_mount) 4115 { 4116 struct mount *mp; 4117 struct vfsopt *opt; 4118 struct statfs *sp; 4119 struct vnode *vp; 4120 char buf[512]; 4121 uint64_t mflags; 4122 u_int flags; 4123 4124 if (!have_addr) { 4125 /* No address given, print short info about all mount points. */ 4126 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4127 db_printf("%p %s on %s (%s)\n", mp, 4128 mp->mnt_stat.f_mntfromname, 4129 mp->mnt_stat.f_mntonname, 4130 mp->mnt_stat.f_fstypename); 4131 if (db_pager_quit) 4132 break; 4133 } 4134 db_printf("\nMore info: show mount <addr>\n"); 4135 return; 4136 } 4137 4138 mp = (struct mount *)addr; 4139 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4140 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4141 4142 buf[0] = '\0'; 4143 mflags = mp->mnt_flag; 4144 #define MNT_FLAG(flag) do { \ 4145 if (mflags & (flag)) { \ 4146 if (buf[0] != '\0') \ 4147 strlcat(buf, ", ", sizeof(buf)); \ 4148 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4149 mflags &= ~(flag); \ 4150 } \ 4151 } while (0) 4152 MNT_FLAG(MNT_RDONLY); 4153 MNT_FLAG(MNT_SYNCHRONOUS); 4154 MNT_FLAG(MNT_NOEXEC); 4155 MNT_FLAG(MNT_NOSUID); 4156 MNT_FLAG(MNT_NFS4ACLS); 4157 MNT_FLAG(MNT_UNION); 4158 MNT_FLAG(MNT_ASYNC); 4159 MNT_FLAG(MNT_SUIDDIR); 4160 MNT_FLAG(MNT_SOFTDEP); 4161 MNT_FLAG(MNT_NOSYMFOLLOW); 4162 MNT_FLAG(MNT_GJOURNAL); 4163 MNT_FLAG(MNT_MULTILABEL); 4164 MNT_FLAG(MNT_ACLS); 4165 MNT_FLAG(MNT_NOATIME); 4166 MNT_FLAG(MNT_NOCLUSTERR); 4167 MNT_FLAG(MNT_NOCLUSTERW); 4168 MNT_FLAG(MNT_SUJ); 4169 MNT_FLAG(MNT_EXRDONLY); 4170 MNT_FLAG(MNT_EXPORTED); 4171 MNT_FLAG(MNT_DEFEXPORTED); 4172 MNT_FLAG(MNT_EXPORTANON); 4173 MNT_FLAG(MNT_EXKERB); 4174 MNT_FLAG(MNT_EXPUBLIC); 4175 MNT_FLAG(MNT_LOCAL); 4176 MNT_FLAG(MNT_QUOTA); 4177 MNT_FLAG(MNT_ROOTFS); 4178 MNT_FLAG(MNT_USER); 4179 MNT_FLAG(MNT_IGNORE); 4180 MNT_FLAG(MNT_UPDATE); 4181 MNT_FLAG(MNT_DELEXPORT); 4182 MNT_FLAG(MNT_RELOAD); 4183 MNT_FLAG(MNT_FORCE); 4184 MNT_FLAG(MNT_SNAPSHOT); 4185 MNT_FLAG(MNT_BYFSID); 4186 #undef MNT_FLAG 4187 if (mflags != 0) { 4188 if (buf[0] != '\0') 4189 strlcat(buf, ", ", sizeof(buf)); 4190 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4191 "0x%016jx", mflags); 4192 } 4193 db_printf(" mnt_flag = %s\n", buf); 4194 4195 buf[0] = '\0'; 4196 flags = mp->mnt_kern_flag; 4197 #define MNT_KERN_FLAG(flag) do { \ 4198 if (flags & (flag)) { \ 4199 if (buf[0] != '\0') \ 4200 strlcat(buf, ", ", sizeof(buf)); \ 4201 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4202 flags &= ~(flag); \ 4203 } \ 4204 } while (0) 4205 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4206 MNT_KERN_FLAG(MNTK_ASYNC); 4207 MNT_KERN_FLAG(MNTK_SOFTDEP); 4208 MNT_KERN_FLAG(MNTK_DRAINING); 4209 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4210 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4211 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4212 MNT_KERN_FLAG(MNTK_NO_IOPF); 4213 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 4214 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 4215 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 4216 MNT_KERN_FLAG(MNTK_MARKER); 4217 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4218 MNT_KERN_FLAG(MNTK_NOASYNC); 4219 MNT_KERN_FLAG(MNTK_UNMOUNT); 4220 MNT_KERN_FLAG(MNTK_MWAIT); 4221 MNT_KERN_FLAG(MNTK_SUSPEND); 4222 MNT_KERN_FLAG(MNTK_SUSPEND2); 4223 MNT_KERN_FLAG(MNTK_SUSPENDED); 4224 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4225 MNT_KERN_FLAG(MNTK_NOKNOTE); 4226 #undef MNT_KERN_FLAG 4227 if (flags != 0) { 4228 if (buf[0] != '\0') 4229 strlcat(buf, ", ", sizeof(buf)); 4230 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4231 "0x%08x", flags); 4232 } 4233 db_printf(" mnt_kern_flag = %s\n", buf); 4234 4235 db_printf(" mnt_opt = "); 4236 opt = TAILQ_FIRST(mp->mnt_opt); 4237 if (opt != NULL) { 4238 db_printf("%s", opt->name); 4239 opt = TAILQ_NEXT(opt, link); 4240 while (opt != NULL) { 4241 db_printf(", %s", opt->name); 4242 opt = TAILQ_NEXT(opt, link); 4243 } 4244 } 4245 db_printf("\n"); 4246 4247 sp = &mp->mnt_stat; 4248 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4249 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4250 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4251 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4252 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4253 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4254 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4255 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4256 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4257 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4258 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4259 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4260 4261 db_printf(" mnt_cred = { uid=%u ruid=%u", 4262 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4263 if (jailed(mp->mnt_cred)) 4264 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4265 db_printf(" }\n"); 4266 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4267 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4268 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4269 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4270 db_printf(" mnt_lazyvnodelistsize = %d\n", 4271 mp->mnt_lazyvnodelistsize); 4272 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4273 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4274 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4275 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4276 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4277 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4278 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4279 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4280 db_printf(" mnt_secondary_accwrites = %d\n", 4281 mp->mnt_secondary_accwrites); 4282 db_printf(" mnt_gjprovider = %s\n", 4283 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4284 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4285 4286 db_printf("\n\nList of active vnodes\n"); 4287 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4288 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4289 vn_printf(vp, "vnode "); 4290 if (db_pager_quit) 4291 break; 4292 } 4293 } 4294 db_printf("\n\nList of inactive vnodes\n"); 4295 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4296 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4297 vn_printf(vp, "vnode "); 4298 if (db_pager_quit) 4299 break; 4300 } 4301 } 4302 } 4303 #endif /* DDB */ 4304 4305 /* 4306 * Fill in a struct xvfsconf based on a struct vfsconf. 4307 */ 4308 static int 4309 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4310 { 4311 struct xvfsconf xvfsp; 4312 4313 bzero(&xvfsp, sizeof(xvfsp)); 4314 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4315 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4316 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4317 xvfsp.vfc_flags = vfsp->vfc_flags; 4318 /* 4319 * These are unused in userland, we keep them 4320 * to not break binary compatibility. 4321 */ 4322 xvfsp.vfc_vfsops = NULL; 4323 xvfsp.vfc_next = NULL; 4324 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4325 } 4326 4327 #ifdef COMPAT_FREEBSD32 4328 struct xvfsconf32 { 4329 uint32_t vfc_vfsops; 4330 char vfc_name[MFSNAMELEN]; 4331 int32_t vfc_typenum; 4332 int32_t vfc_refcount; 4333 int32_t vfc_flags; 4334 uint32_t vfc_next; 4335 }; 4336 4337 static int 4338 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4339 { 4340 struct xvfsconf32 xvfsp; 4341 4342 bzero(&xvfsp, sizeof(xvfsp)); 4343 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4344 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4345 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4346 xvfsp.vfc_flags = vfsp->vfc_flags; 4347 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4348 } 4349 #endif 4350 4351 /* 4352 * Top level filesystem related information gathering. 4353 */ 4354 static int 4355 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4356 { 4357 struct vfsconf *vfsp; 4358 int error; 4359 4360 error = 0; 4361 vfsconf_slock(); 4362 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4363 #ifdef COMPAT_FREEBSD32 4364 if (req->flags & SCTL_MASK32) 4365 error = vfsconf2x32(req, vfsp); 4366 else 4367 #endif 4368 error = vfsconf2x(req, vfsp); 4369 if (error) 4370 break; 4371 } 4372 vfsconf_sunlock(); 4373 return (error); 4374 } 4375 4376 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4377 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4378 "S,xvfsconf", "List of all configured filesystems"); 4379 4380 #ifndef BURN_BRIDGES 4381 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4382 4383 static int 4384 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4385 { 4386 int *name = (int *)arg1 - 1; /* XXX */ 4387 u_int namelen = arg2 + 1; /* XXX */ 4388 struct vfsconf *vfsp; 4389 4390 log(LOG_WARNING, "userland calling deprecated sysctl, " 4391 "please rebuild world\n"); 4392 4393 #if 1 || defined(COMPAT_PRELITE2) 4394 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4395 if (namelen == 1) 4396 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4397 #endif 4398 4399 switch (name[1]) { 4400 case VFS_MAXTYPENUM: 4401 if (namelen != 2) 4402 return (ENOTDIR); 4403 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4404 case VFS_CONF: 4405 if (namelen != 3) 4406 return (ENOTDIR); /* overloaded */ 4407 vfsconf_slock(); 4408 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4409 if (vfsp->vfc_typenum == name[2]) 4410 break; 4411 } 4412 vfsconf_sunlock(); 4413 if (vfsp == NULL) 4414 return (EOPNOTSUPP); 4415 #ifdef COMPAT_FREEBSD32 4416 if (req->flags & SCTL_MASK32) 4417 return (vfsconf2x32(req, vfsp)); 4418 else 4419 #endif 4420 return (vfsconf2x(req, vfsp)); 4421 } 4422 return (EOPNOTSUPP); 4423 } 4424 4425 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4426 CTLFLAG_MPSAFE, vfs_sysctl, 4427 "Generic filesystem"); 4428 4429 #if 1 || defined(COMPAT_PRELITE2) 4430 4431 static int 4432 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4433 { 4434 int error; 4435 struct vfsconf *vfsp; 4436 struct ovfsconf ovfs; 4437 4438 vfsconf_slock(); 4439 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4440 bzero(&ovfs, sizeof(ovfs)); 4441 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4442 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4443 ovfs.vfc_index = vfsp->vfc_typenum; 4444 ovfs.vfc_refcount = vfsp->vfc_refcount; 4445 ovfs.vfc_flags = vfsp->vfc_flags; 4446 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4447 if (error != 0) { 4448 vfsconf_sunlock(); 4449 return (error); 4450 } 4451 } 4452 vfsconf_sunlock(); 4453 return (0); 4454 } 4455 4456 #endif /* 1 || COMPAT_PRELITE2 */ 4457 #endif /* !BURN_BRIDGES */ 4458 4459 #define KINFO_VNODESLOP 10 4460 #ifdef notyet 4461 /* 4462 * Dump vnode list (via sysctl). 4463 */ 4464 /* ARGSUSED */ 4465 static int 4466 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4467 { 4468 struct xvnode *xvn; 4469 struct mount *mp; 4470 struct vnode *vp; 4471 int error, len, n; 4472 4473 /* 4474 * Stale numvnodes access is not fatal here. 4475 */ 4476 req->lock = 0; 4477 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4478 if (!req->oldptr) 4479 /* Make an estimate */ 4480 return (SYSCTL_OUT(req, 0, len)); 4481 4482 error = sysctl_wire_old_buffer(req, 0); 4483 if (error != 0) 4484 return (error); 4485 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4486 n = 0; 4487 mtx_lock(&mountlist_mtx); 4488 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4489 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4490 continue; 4491 MNT_ILOCK(mp); 4492 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4493 if (n == len) 4494 break; 4495 vref(vp); 4496 xvn[n].xv_size = sizeof *xvn; 4497 xvn[n].xv_vnode = vp; 4498 xvn[n].xv_id = 0; /* XXX compat */ 4499 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4500 XV_COPY(usecount); 4501 XV_COPY(writecount); 4502 XV_COPY(holdcnt); 4503 XV_COPY(mount); 4504 XV_COPY(numoutput); 4505 XV_COPY(type); 4506 #undef XV_COPY 4507 xvn[n].xv_flag = vp->v_vflag; 4508 4509 switch (vp->v_type) { 4510 case VREG: 4511 case VDIR: 4512 case VLNK: 4513 break; 4514 case VBLK: 4515 case VCHR: 4516 if (vp->v_rdev == NULL) { 4517 vrele(vp); 4518 continue; 4519 } 4520 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4521 break; 4522 case VSOCK: 4523 xvn[n].xv_socket = vp->v_socket; 4524 break; 4525 case VFIFO: 4526 xvn[n].xv_fifo = vp->v_fifoinfo; 4527 break; 4528 case VNON: 4529 case VBAD: 4530 default: 4531 /* shouldn't happen? */ 4532 vrele(vp); 4533 continue; 4534 } 4535 vrele(vp); 4536 ++n; 4537 } 4538 MNT_IUNLOCK(mp); 4539 mtx_lock(&mountlist_mtx); 4540 vfs_unbusy(mp); 4541 if (n == len) 4542 break; 4543 } 4544 mtx_unlock(&mountlist_mtx); 4545 4546 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4547 free(xvn, M_TEMP); 4548 return (error); 4549 } 4550 4551 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4552 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4553 ""); 4554 #endif 4555 4556 static void 4557 unmount_or_warn(struct mount *mp) 4558 { 4559 int error; 4560 4561 error = dounmount(mp, MNT_FORCE, curthread); 4562 if (error != 0) { 4563 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4564 if (error == EBUSY) 4565 printf("BUSY)\n"); 4566 else 4567 printf("%d)\n", error); 4568 } 4569 } 4570 4571 /* 4572 * Unmount all filesystems. The list is traversed in reverse order 4573 * of mounting to avoid dependencies. 4574 */ 4575 void 4576 vfs_unmountall(void) 4577 { 4578 struct mount *mp, *tmp; 4579 4580 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4581 4582 /* 4583 * Since this only runs when rebooting, it is not interlocked. 4584 */ 4585 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4586 vfs_ref(mp); 4587 4588 /* 4589 * Forcibly unmounting "/dev" before "/" would prevent clean 4590 * unmount of the latter. 4591 */ 4592 if (mp == rootdevmp) 4593 continue; 4594 4595 unmount_or_warn(mp); 4596 } 4597 4598 if (rootdevmp != NULL) 4599 unmount_or_warn(rootdevmp); 4600 } 4601 4602 static void 4603 vfs_deferred_inactive(struct vnode *vp, int lkflags) 4604 { 4605 4606 ASSERT_VI_LOCKED(vp, __func__); 4607 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, ("VI_DEFINACT still set")); 4608 if ((vp->v_iflag & VI_OWEINACT) == 0) { 4609 vdropl(vp); 4610 return; 4611 } 4612 if (vn_lock(vp, lkflags) == 0) { 4613 VI_LOCK(vp); 4614 vinactive(vp); 4615 VOP_UNLOCK(vp); 4616 vdropl(vp); 4617 return; 4618 } 4619 vdefer_inactive_unlocked(vp); 4620 } 4621 4622 static int 4623 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 4624 { 4625 4626 return (vp->v_iflag & VI_DEFINACT); 4627 } 4628 4629 static void __noinline 4630 vfs_periodic_inactive(struct mount *mp, int flags) 4631 { 4632 struct vnode *vp, *mvp; 4633 int lkflags; 4634 4635 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4636 if (flags != MNT_WAIT) 4637 lkflags |= LK_NOWAIT; 4638 4639 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 4640 if ((vp->v_iflag & VI_DEFINACT) == 0) { 4641 VI_UNLOCK(vp); 4642 continue; 4643 } 4644 vp->v_iflag &= ~VI_DEFINACT; 4645 vfs_deferred_inactive(vp, lkflags); 4646 } 4647 } 4648 4649 static inline bool 4650 vfs_want_msync(struct vnode *vp) 4651 { 4652 struct vm_object *obj; 4653 4654 /* 4655 * This test may be performed without any locks held. 4656 * We rely on vm_object's type stability. 4657 */ 4658 if (vp->v_vflag & VV_NOSYNC) 4659 return (false); 4660 obj = vp->v_object; 4661 return (obj != NULL && vm_object_mightbedirty(obj)); 4662 } 4663 4664 static int 4665 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 4666 { 4667 4668 if (vp->v_vflag & VV_NOSYNC) 4669 return (false); 4670 if (vp->v_iflag & VI_DEFINACT) 4671 return (true); 4672 return (vfs_want_msync(vp)); 4673 } 4674 4675 static void __noinline 4676 vfs_periodic_msync_inactive(struct mount *mp, int flags) 4677 { 4678 struct vnode *vp, *mvp; 4679 struct vm_object *obj; 4680 struct thread *td; 4681 int lkflags, objflags; 4682 bool seen_defer; 4683 4684 td = curthread; 4685 4686 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4687 if (flags != MNT_WAIT) { 4688 lkflags |= LK_NOWAIT; 4689 objflags = OBJPC_NOSYNC; 4690 } else { 4691 objflags = OBJPC_SYNC; 4692 } 4693 4694 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 4695 seen_defer = false; 4696 if (vp->v_iflag & VI_DEFINACT) { 4697 vp->v_iflag &= ~VI_DEFINACT; 4698 seen_defer = true; 4699 } 4700 if (!vfs_want_msync(vp)) { 4701 if (seen_defer) 4702 vfs_deferred_inactive(vp, lkflags); 4703 else 4704 VI_UNLOCK(vp); 4705 continue; 4706 } 4707 if (vget(vp, lkflags, td) == 0) { 4708 obj = vp->v_object; 4709 if (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0) { 4710 VM_OBJECT_WLOCK(obj); 4711 vm_object_page_clean(obj, 0, 0, objflags); 4712 VM_OBJECT_WUNLOCK(obj); 4713 } 4714 vput(vp); 4715 if (seen_defer) 4716 vdrop(vp); 4717 } else { 4718 if (seen_defer) 4719 vdefer_inactive_unlocked(vp); 4720 } 4721 } 4722 } 4723 4724 void 4725 vfs_periodic(struct mount *mp, int flags) 4726 { 4727 4728 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4729 4730 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4731 vfs_periodic_inactive(mp, flags); 4732 else 4733 vfs_periodic_msync_inactive(mp, flags); 4734 } 4735 4736 static void 4737 destroy_vpollinfo_free(struct vpollinfo *vi) 4738 { 4739 4740 knlist_destroy(&vi->vpi_selinfo.si_note); 4741 mtx_destroy(&vi->vpi_lock); 4742 uma_zfree(vnodepoll_zone, vi); 4743 } 4744 4745 static void 4746 destroy_vpollinfo(struct vpollinfo *vi) 4747 { 4748 4749 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4750 seldrain(&vi->vpi_selinfo); 4751 destroy_vpollinfo_free(vi); 4752 } 4753 4754 /* 4755 * Initialize per-vnode helper structure to hold poll-related state. 4756 */ 4757 void 4758 v_addpollinfo(struct vnode *vp) 4759 { 4760 struct vpollinfo *vi; 4761 4762 if (vp->v_pollinfo != NULL) 4763 return; 4764 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4765 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4766 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4767 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4768 VI_LOCK(vp); 4769 if (vp->v_pollinfo != NULL) { 4770 VI_UNLOCK(vp); 4771 destroy_vpollinfo_free(vi); 4772 return; 4773 } 4774 vp->v_pollinfo = vi; 4775 VI_UNLOCK(vp); 4776 } 4777 4778 /* 4779 * Record a process's interest in events which might happen to 4780 * a vnode. Because poll uses the historic select-style interface 4781 * internally, this routine serves as both the ``check for any 4782 * pending events'' and the ``record my interest in future events'' 4783 * functions. (These are done together, while the lock is held, 4784 * to avoid race conditions.) 4785 */ 4786 int 4787 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4788 { 4789 4790 v_addpollinfo(vp); 4791 mtx_lock(&vp->v_pollinfo->vpi_lock); 4792 if (vp->v_pollinfo->vpi_revents & events) { 4793 /* 4794 * This leaves events we are not interested 4795 * in available for the other process which 4796 * which presumably had requested them 4797 * (otherwise they would never have been 4798 * recorded). 4799 */ 4800 events &= vp->v_pollinfo->vpi_revents; 4801 vp->v_pollinfo->vpi_revents &= ~events; 4802 4803 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4804 return (events); 4805 } 4806 vp->v_pollinfo->vpi_events |= events; 4807 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4808 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4809 return (0); 4810 } 4811 4812 /* 4813 * Routine to create and manage a filesystem syncer vnode. 4814 */ 4815 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4816 static int sync_fsync(struct vop_fsync_args *); 4817 static int sync_inactive(struct vop_inactive_args *); 4818 static int sync_reclaim(struct vop_reclaim_args *); 4819 4820 static struct vop_vector sync_vnodeops = { 4821 .vop_bypass = VOP_EOPNOTSUPP, 4822 .vop_close = sync_close, /* close */ 4823 .vop_fsync = sync_fsync, /* fsync */ 4824 .vop_inactive = sync_inactive, /* inactive */ 4825 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 4826 .vop_reclaim = sync_reclaim, /* reclaim */ 4827 .vop_lock1 = vop_stdlock, /* lock */ 4828 .vop_unlock = vop_stdunlock, /* unlock */ 4829 .vop_islocked = vop_stdislocked, /* islocked */ 4830 }; 4831 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 4832 4833 /* 4834 * Create a new filesystem syncer vnode for the specified mount point. 4835 */ 4836 void 4837 vfs_allocate_syncvnode(struct mount *mp) 4838 { 4839 struct vnode *vp; 4840 struct bufobj *bo; 4841 static long start, incr, next; 4842 int error; 4843 4844 /* Allocate a new vnode */ 4845 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4846 if (error != 0) 4847 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4848 vp->v_type = VNON; 4849 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4850 vp->v_vflag |= VV_FORCEINSMQ; 4851 error = insmntque(vp, mp); 4852 if (error != 0) 4853 panic("vfs_allocate_syncvnode: insmntque() failed"); 4854 vp->v_vflag &= ~VV_FORCEINSMQ; 4855 VOP_UNLOCK(vp); 4856 /* 4857 * Place the vnode onto the syncer worklist. We attempt to 4858 * scatter them about on the list so that they will go off 4859 * at evenly distributed times even if all the filesystems 4860 * are mounted at once. 4861 */ 4862 next += incr; 4863 if (next == 0 || next > syncer_maxdelay) { 4864 start /= 2; 4865 incr /= 2; 4866 if (start == 0) { 4867 start = syncer_maxdelay / 2; 4868 incr = syncer_maxdelay; 4869 } 4870 next = start; 4871 } 4872 bo = &vp->v_bufobj; 4873 BO_LOCK(bo); 4874 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4875 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4876 mtx_lock(&sync_mtx); 4877 sync_vnode_count++; 4878 if (mp->mnt_syncer == NULL) { 4879 mp->mnt_syncer = vp; 4880 vp = NULL; 4881 } 4882 mtx_unlock(&sync_mtx); 4883 BO_UNLOCK(bo); 4884 if (vp != NULL) { 4885 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4886 vgone(vp); 4887 vput(vp); 4888 } 4889 } 4890 4891 void 4892 vfs_deallocate_syncvnode(struct mount *mp) 4893 { 4894 struct vnode *vp; 4895 4896 mtx_lock(&sync_mtx); 4897 vp = mp->mnt_syncer; 4898 if (vp != NULL) 4899 mp->mnt_syncer = NULL; 4900 mtx_unlock(&sync_mtx); 4901 if (vp != NULL) 4902 vrele(vp); 4903 } 4904 4905 /* 4906 * Do a lazy sync of the filesystem. 4907 */ 4908 static int 4909 sync_fsync(struct vop_fsync_args *ap) 4910 { 4911 struct vnode *syncvp = ap->a_vp; 4912 struct mount *mp = syncvp->v_mount; 4913 int error, save; 4914 struct bufobj *bo; 4915 4916 /* 4917 * We only need to do something if this is a lazy evaluation. 4918 */ 4919 if (ap->a_waitfor != MNT_LAZY) 4920 return (0); 4921 4922 /* 4923 * Move ourselves to the back of the sync list. 4924 */ 4925 bo = &syncvp->v_bufobj; 4926 BO_LOCK(bo); 4927 vn_syncer_add_to_worklist(bo, syncdelay); 4928 BO_UNLOCK(bo); 4929 4930 /* 4931 * Walk the list of vnodes pushing all that are dirty and 4932 * not already on the sync list. 4933 */ 4934 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4935 return (0); 4936 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4937 vfs_unbusy(mp); 4938 return (0); 4939 } 4940 save = curthread_pflags_set(TDP_SYNCIO); 4941 /* 4942 * The filesystem at hand may be idle with free vnodes stored in the 4943 * batch. Return them instead of letting them stay there indefinitely. 4944 */ 4945 vfs_periodic(mp, MNT_NOWAIT); 4946 error = VFS_SYNC(mp, MNT_LAZY); 4947 curthread_pflags_restore(save); 4948 vn_finished_write(mp); 4949 vfs_unbusy(mp); 4950 return (error); 4951 } 4952 4953 /* 4954 * The syncer vnode is no referenced. 4955 */ 4956 static int 4957 sync_inactive(struct vop_inactive_args *ap) 4958 { 4959 4960 vgone(ap->a_vp); 4961 return (0); 4962 } 4963 4964 /* 4965 * The syncer vnode is no longer needed and is being decommissioned. 4966 * 4967 * Modifications to the worklist must be protected by sync_mtx. 4968 */ 4969 static int 4970 sync_reclaim(struct vop_reclaim_args *ap) 4971 { 4972 struct vnode *vp = ap->a_vp; 4973 struct bufobj *bo; 4974 4975 bo = &vp->v_bufobj; 4976 BO_LOCK(bo); 4977 mtx_lock(&sync_mtx); 4978 if (vp->v_mount->mnt_syncer == vp) 4979 vp->v_mount->mnt_syncer = NULL; 4980 if (bo->bo_flag & BO_ONWORKLST) { 4981 LIST_REMOVE(bo, bo_synclist); 4982 syncer_worklist_len--; 4983 sync_vnode_count--; 4984 bo->bo_flag &= ~BO_ONWORKLST; 4985 } 4986 mtx_unlock(&sync_mtx); 4987 BO_UNLOCK(bo); 4988 4989 return (0); 4990 } 4991 4992 int 4993 vn_need_pageq_flush(struct vnode *vp) 4994 { 4995 struct vm_object *obj; 4996 int need; 4997 4998 VNPASS(VN_IS_DOOMED(vp) || mtx_owned(VI_MTX(vp)), vp); 4999 need = 0; 5000 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5001 vm_object_mightbedirty(obj)) 5002 need = 1; 5003 return (need); 5004 } 5005 5006 /* 5007 * Check if vnode represents a disk device 5008 */ 5009 int 5010 vn_isdisk(struct vnode *vp, int *errp) 5011 { 5012 int error; 5013 5014 if (vp->v_type != VCHR) { 5015 error = ENOTBLK; 5016 goto out; 5017 } 5018 error = 0; 5019 dev_lock(); 5020 if (vp->v_rdev == NULL) 5021 error = ENXIO; 5022 else if (vp->v_rdev->si_devsw == NULL) 5023 error = ENXIO; 5024 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5025 error = ENOTBLK; 5026 dev_unlock(); 5027 out: 5028 if (errp != NULL) 5029 *errp = error; 5030 return (error == 0); 5031 } 5032 5033 /* 5034 * Common filesystem object access control check routine. Accepts a 5035 * vnode's type, "mode", uid and gid, requested access mode, credentials, 5036 * and optional call-by-reference privused argument allowing vaccess() 5037 * to indicate to the caller whether privilege was used to satisfy the 5038 * request (obsoleted). Returns 0 on success, or an errno on failure. 5039 */ 5040 int 5041 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5042 accmode_t accmode, struct ucred *cred, int *privused) 5043 { 5044 accmode_t dac_granted; 5045 accmode_t priv_granted; 5046 5047 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5048 ("invalid bit in accmode")); 5049 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5050 ("VAPPEND without VWRITE")); 5051 5052 /* 5053 * Look for a normal, non-privileged way to access the file/directory 5054 * as requested. If it exists, go with that. 5055 */ 5056 5057 if (privused != NULL) 5058 *privused = 0; 5059 5060 dac_granted = 0; 5061 5062 /* Check the owner. */ 5063 if (cred->cr_uid == file_uid) { 5064 dac_granted |= VADMIN; 5065 if (file_mode & S_IXUSR) 5066 dac_granted |= VEXEC; 5067 if (file_mode & S_IRUSR) 5068 dac_granted |= VREAD; 5069 if (file_mode & S_IWUSR) 5070 dac_granted |= (VWRITE | VAPPEND); 5071 5072 if ((accmode & dac_granted) == accmode) 5073 return (0); 5074 5075 goto privcheck; 5076 } 5077 5078 /* Otherwise, check the groups (first match) */ 5079 if (groupmember(file_gid, cred)) { 5080 if (file_mode & S_IXGRP) 5081 dac_granted |= VEXEC; 5082 if (file_mode & S_IRGRP) 5083 dac_granted |= VREAD; 5084 if (file_mode & S_IWGRP) 5085 dac_granted |= (VWRITE | VAPPEND); 5086 5087 if ((accmode & dac_granted) == accmode) 5088 return (0); 5089 5090 goto privcheck; 5091 } 5092 5093 /* Otherwise, check everyone else. */ 5094 if (file_mode & S_IXOTH) 5095 dac_granted |= VEXEC; 5096 if (file_mode & S_IROTH) 5097 dac_granted |= VREAD; 5098 if (file_mode & S_IWOTH) 5099 dac_granted |= (VWRITE | VAPPEND); 5100 if ((accmode & dac_granted) == accmode) 5101 return (0); 5102 5103 privcheck: 5104 /* 5105 * Build a privilege mask to determine if the set of privileges 5106 * satisfies the requirements when combined with the granted mask 5107 * from above. For each privilege, if the privilege is required, 5108 * bitwise or the request type onto the priv_granted mask. 5109 */ 5110 priv_granted = 0; 5111 5112 if (type == VDIR) { 5113 /* 5114 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5115 * requests, instead of PRIV_VFS_EXEC. 5116 */ 5117 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5118 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5119 priv_granted |= VEXEC; 5120 } else { 5121 /* 5122 * Ensure that at least one execute bit is on. Otherwise, 5123 * a privileged user will always succeed, and we don't want 5124 * this to happen unless the file really is executable. 5125 */ 5126 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5127 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5128 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5129 priv_granted |= VEXEC; 5130 } 5131 5132 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5133 !priv_check_cred(cred, PRIV_VFS_READ)) 5134 priv_granted |= VREAD; 5135 5136 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5137 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5138 priv_granted |= (VWRITE | VAPPEND); 5139 5140 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5141 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5142 priv_granted |= VADMIN; 5143 5144 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5145 /* XXX audit: privilege used */ 5146 if (privused != NULL) 5147 *privused = 1; 5148 return (0); 5149 } 5150 5151 return ((accmode & VADMIN) ? EPERM : EACCES); 5152 } 5153 5154 /* 5155 * Credential check based on process requesting service, and per-attribute 5156 * permissions. 5157 */ 5158 int 5159 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5160 struct thread *td, accmode_t accmode) 5161 { 5162 5163 /* 5164 * Kernel-invoked always succeeds. 5165 */ 5166 if (cred == NOCRED) 5167 return (0); 5168 5169 /* 5170 * Do not allow privileged processes in jail to directly manipulate 5171 * system attributes. 5172 */ 5173 switch (attrnamespace) { 5174 case EXTATTR_NAMESPACE_SYSTEM: 5175 /* Potentially should be: return (EPERM); */ 5176 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5177 case EXTATTR_NAMESPACE_USER: 5178 return (VOP_ACCESS(vp, accmode, cred, td)); 5179 default: 5180 return (EPERM); 5181 } 5182 } 5183 5184 #ifdef DEBUG_VFS_LOCKS 5185 /* 5186 * This only exists to suppress warnings from unlocked specfs accesses. It is 5187 * no longer ok to have an unlocked VFS. 5188 */ 5189 #define IGNORE_LOCK(vp) (KERNEL_PANICKED() || (vp) == NULL || \ 5190 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 5191 5192 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5193 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5194 "Drop into debugger on lock violation"); 5195 5196 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5197 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5198 0, "Check for interlock across VOPs"); 5199 5200 int vfs_badlock_print = 1; /* Print lock violations. */ 5201 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5202 0, "Print lock violations"); 5203 5204 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5205 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5206 0, "Print vnode details on lock violations"); 5207 5208 #ifdef KDB 5209 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5210 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5211 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5212 #endif 5213 5214 static void 5215 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5216 { 5217 5218 #ifdef KDB 5219 if (vfs_badlock_backtrace) 5220 kdb_backtrace(); 5221 #endif 5222 if (vfs_badlock_vnode) 5223 vn_printf(vp, "vnode "); 5224 if (vfs_badlock_print) 5225 printf("%s: %p %s\n", str, (void *)vp, msg); 5226 if (vfs_badlock_ddb) 5227 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5228 } 5229 5230 void 5231 assert_vi_locked(struct vnode *vp, const char *str) 5232 { 5233 5234 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5235 vfs_badlock("interlock is not locked but should be", str, vp); 5236 } 5237 5238 void 5239 assert_vi_unlocked(struct vnode *vp, const char *str) 5240 { 5241 5242 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5243 vfs_badlock("interlock is locked but should not be", str, vp); 5244 } 5245 5246 void 5247 assert_vop_locked(struct vnode *vp, const char *str) 5248 { 5249 int locked; 5250 5251 if (!IGNORE_LOCK(vp)) { 5252 locked = VOP_ISLOCKED(vp); 5253 if (locked == 0 || locked == LK_EXCLOTHER) 5254 vfs_badlock("is not locked but should be", str, vp); 5255 } 5256 } 5257 5258 void 5259 assert_vop_unlocked(struct vnode *vp, const char *str) 5260 { 5261 5262 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5263 vfs_badlock("is locked but should not be", str, vp); 5264 } 5265 5266 void 5267 assert_vop_elocked(struct vnode *vp, const char *str) 5268 { 5269 5270 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5271 vfs_badlock("is not exclusive locked but should be", str, vp); 5272 } 5273 #endif /* DEBUG_VFS_LOCKS */ 5274 5275 void 5276 vop_rename_fail(struct vop_rename_args *ap) 5277 { 5278 5279 if (ap->a_tvp != NULL) 5280 vput(ap->a_tvp); 5281 if (ap->a_tdvp == ap->a_tvp) 5282 vrele(ap->a_tdvp); 5283 else 5284 vput(ap->a_tdvp); 5285 vrele(ap->a_fdvp); 5286 vrele(ap->a_fvp); 5287 } 5288 5289 void 5290 vop_rename_pre(void *ap) 5291 { 5292 struct vop_rename_args *a = ap; 5293 5294 #ifdef DEBUG_VFS_LOCKS 5295 if (a->a_tvp) 5296 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5297 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5298 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5299 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5300 5301 /* Check the source (from). */ 5302 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5303 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5304 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5305 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5306 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5307 5308 /* Check the target. */ 5309 if (a->a_tvp) 5310 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5311 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5312 #endif 5313 if (a->a_tdvp != a->a_fdvp) 5314 vhold(a->a_fdvp); 5315 if (a->a_tvp != a->a_fvp) 5316 vhold(a->a_fvp); 5317 vhold(a->a_tdvp); 5318 if (a->a_tvp) 5319 vhold(a->a_tvp); 5320 } 5321 5322 #ifdef DEBUG_VFS_LOCKS 5323 void 5324 vop_strategy_pre(void *ap) 5325 { 5326 struct vop_strategy_args *a; 5327 struct buf *bp; 5328 5329 a = ap; 5330 bp = a->a_bp; 5331 5332 /* 5333 * Cluster ops lock their component buffers but not the IO container. 5334 */ 5335 if ((bp->b_flags & B_CLUSTER) != 0) 5336 return; 5337 5338 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5339 if (vfs_badlock_print) 5340 printf( 5341 "VOP_STRATEGY: bp is not locked but should be\n"); 5342 if (vfs_badlock_ddb) 5343 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5344 } 5345 } 5346 5347 void 5348 vop_lock_pre(void *ap) 5349 { 5350 struct vop_lock1_args *a = ap; 5351 5352 if ((a->a_flags & LK_INTERLOCK) == 0) 5353 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5354 else 5355 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5356 } 5357 5358 void 5359 vop_lock_post(void *ap, int rc) 5360 { 5361 struct vop_lock1_args *a = ap; 5362 5363 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5364 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5365 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5366 } 5367 5368 void 5369 vop_unlock_pre(void *ap) 5370 { 5371 struct vop_unlock_args *a = ap; 5372 5373 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5374 } 5375 5376 void 5377 vop_unlock_post(void *ap, int rc) 5378 { 5379 return; 5380 } 5381 5382 void 5383 vop_need_inactive_pre(void *ap) 5384 { 5385 struct vop_need_inactive_args *a = ap; 5386 5387 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5388 } 5389 5390 void 5391 vop_need_inactive_post(void *ap, int rc) 5392 { 5393 struct vop_need_inactive_args *a = ap; 5394 5395 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5396 } 5397 #endif 5398 5399 void 5400 vop_create_post(void *ap, int rc) 5401 { 5402 struct vop_create_args *a = ap; 5403 5404 if (!rc) 5405 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5406 } 5407 5408 void 5409 vop_deleteextattr_post(void *ap, int rc) 5410 { 5411 struct vop_deleteextattr_args *a = ap; 5412 5413 if (!rc) 5414 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5415 } 5416 5417 void 5418 vop_link_post(void *ap, int rc) 5419 { 5420 struct vop_link_args *a = ap; 5421 5422 if (!rc) { 5423 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 5424 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 5425 } 5426 } 5427 5428 void 5429 vop_mkdir_post(void *ap, int rc) 5430 { 5431 struct vop_mkdir_args *a = ap; 5432 5433 if (!rc) 5434 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5435 } 5436 5437 void 5438 vop_mknod_post(void *ap, int rc) 5439 { 5440 struct vop_mknod_args *a = ap; 5441 5442 if (!rc) 5443 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5444 } 5445 5446 void 5447 vop_reclaim_post(void *ap, int rc) 5448 { 5449 struct vop_reclaim_args *a = ap; 5450 5451 if (!rc) 5452 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 5453 } 5454 5455 void 5456 vop_remove_post(void *ap, int rc) 5457 { 5458 struct vop_remove_args *a = ap; 5459 5460 if (!rc) { 5461 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5462 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5463 } 5464 } 5465 5466 void 5467 vop_rename_post(void *ap, int rc) 5468 { 5469 struct vop_rename_args *a = ap; 5470 long hint; 5471 5472 if (!rc) { 5473 hint = NOTE_WRITE; 5474 if (a->a_fdvp == a->a_tdvp) { 5475 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5476 hint |= NOTE_LINK; 5477 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5478 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5479 } else { 5480 hint |= NOTE_EXTEND; 5481 if (a->a_fvp->v_type == VDIR) 5482 hint |= NOTE_LINK; 5483 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5484 5485 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5486 a->a_tvp->v_type == VDIR) 5487 hint &= ~NOTE_LINK; 5488 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5489 } 5490 5491 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5492 if (a->a_tvp) 5493 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5494 } 5495 if (a->a_tdvp != a->a_fdvp) 5496 vdrop(a->a_fdvp); 5497 if (a->a_tvp != a->a_fvp) 5498 vdrop(a->a_fvp); 5499 vdrop(a->a_tdvp); 5500 if (a->a_tvp) 5501 vdrop(a->a_tvp); 5502 } 5503 5504 void 5505 vop_rmdir_post(void *ap, int rc) 5506 { 5507 struct vop_rmdir_args *a = ap; 5508 5509 if (!rc) { 5510 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5511 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5512 } 5513 } 5514 5515 void 5516 vop_setattr_post(void *ap, int rc) 5517 { 5518 struct vop_setattr_args *a = ap; 5519 5520 if (!rc) 5521 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5522 } 5523 5524 void 5525 vop_setextattr_post(void *ap, int rc) 5526 { 5527 struct vop_setextattr_args *a = ap; 5528 5529 if (!rc) 5530 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5531 } 5532 5533 void 5534 vop_symlink_post(void *ap, int rc) 5535 { 5536 struct vop_symlink_args *a = ap; 5537 5538 if (!rc) 5539 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5540 } 5541 5542 void 5543 vop_open_post(void *ap, int rc) 5544 { 5545 struct vop_open_args *a = ap; 5546 5547 if (!rc) 5548 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5549 } 5550 5551 void 5552 vop_close_post(void *ap, int rc) 5553 { 5554 struct vop_close_args *a = ap; 5555 5556 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5557 !VN_IS_DOOMED(a->a_vp))) { 5558 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5559 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5560 } 5561 } 5562 5563 void 5564 vop_read_post(void *ap, int rc) 5565 { 5566 struct vop_read_args *a = ap; 5567 5568 if (!rc) 5569 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5570 } 5571 5572 void 5573 vop_readdir_post(void *ap, int rc) 5574 { 5575 struct vop_readdir_args *a = ap; 5576 5577 if (!rc) 5578 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5579 } 5580 5581 static struct knlist fs_knlist; 5582 5583 static void 5584 vfs_event_init(void *arg) 5585 { 5586 knlist_init_mtx(&fs_knlist, NULL); 5587 } 5588 /* XXX - correct order? */ 5589 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5590 5591 void 5592 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5593 { 5594 5595 KNOTE_UNLOCKED(&fs_knlist, event); 5596 } 5597 5598 static int filt_fsattach(struct knote *kn); 5599 static void filt_fsdetach(struct knote *kn); 5600 static int filt_fsevent(struct knote *kn, long hint); 5601 5602 struct filterops fs_filtops = { 5603 .f_isfd = 0, 5604 .f_attach = filt_fsattach, 5605 .f_detach = filt_fsdetach, 5606 .f_event = filt_fsevent 5607 }; 5608 5609 static int 5610 filt_fsattach(struct knote *kn) 5611 { 5612 5613 kn->kn_flags |= EV_CLEAR; 5614 knlist_add(&fs_knlist, kn, 0); 5615 return (0); 5616 } 5617 5618 static void 5619 filt_fsdetach(struct knote *kn) 5620 { 5621 5622 knlist_remove(&fs_knlist, kn, 0); 5623 } 5624 5625 static int 5626 filt_fsevent(struct knote *kn, long hint) 5627 { 5628 5629 kn->kn_fflags |= hint; 5630 return (kn->kn_fflags != 0); 5631 } 5632 5633 static int 5634 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5635 { 5636 struct vfsidctl vc; 5637 int error; 5638 struct mount *mp; 5639 5640 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5641 if (error) 5642 return (error); 5643 if (vc.vc_vers != VFS_CTL_VERS1) 5644 return (EINVAL); 5645 mp = vfs_getvfs(&vc.vc_fsid); 5646 if (mp == NULL) 5647 return (ENOENT); 5648 /* ensure that a specific sysctl goes to the right filesystem. */ 5649 if (strcmp(vc.vc_fstypename, "*") != 0 && 5650 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5651 vfs_rel(mp); 5652 return (EINVAL); 5653 } 5654 VCTLTOREQ(&vc, req); 5655 error = VFS_SYSCTL(mp, vc.vc_op, req); 5656 vfs_rel(mp); 5657 return (error); 5658 } 5659 5660 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 5661 NULL, 0, sysctl_vfs_ctl, "", 5662 "Sysctl by fsid"); 5663 5664 /* 5665 * Function to initialize a va_filerev field sensibly. 5666 * XXX: Wouldn't a random number make a lot more sense ?? 5667 */ 5668 u_quad_t 5669 init_va_filerev(void) 5670 { 5671 struct bintime bt; 5672 5673 getbinuptime(&bt); 5674 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5675 } 5676 5677 static int filt_vfsread(struct knote *kn, long hint); 5678 static int filt_vfswrite(struct knote *kn, long hint); 5679 static int filt_vfsvnode(struct knote *kn, long hint); 5680 static void filt_vfsdetach(struct knote *kn); 5681 static struct filterops vfsread_filtops = { 5682 .f_isfd = 1, 5683 .f_detach = filt_vfsdetach, 5684 .f_event = filt_vfsread 5685 }; 5686 static struct filterops vfswrite_filtops = { 5687 .f_isfd = 1, 5688 .f_detach = filt_vfsdetach, 5689 .f_event = filt_vfswrite 5690 }; 5691 static struct filterops vfsvnode_filtops = { 5692 .f_isfd = 1, 5693 .f_detach = filt_vfsdetach, 5694 .f_event = filt_vfsvnode 5695 }; 5696 5697 static void 5698 vfs_knllock(void *arg) 5699 { 5700 struct vnode *vp = arg; 5701 5702 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5703 } 5704 5705 static void 5706 vfs_knlunlock(void *arg) 5707 { 5708 struct vnode *vp = arg; 5709 5710 VOP_UNLOCK(vp); 5711 } 5712 5713 static void 5714 vfs_knl_assert_locked(void *arg) 5715 { 5716 #ifdef DEBUG_VFS_LOCKS 5717 struct vnode *vp = arg; 5718 5719 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5720 #endif 5721 } 5722 5723 static void 5724 vfs_knl_assert_unlocked(void *arg) 5725 { 5726 #ifdef DEBUG_VFS_LOCKS 5727 struct vnode *vp = arg; 5728 5729 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5730 #endif 5731 } 5732 5733 int 5734 vfs_kqfilter(struct vop_kqfilter_args *ap) 5735 { 5736 struct vnode *vp = ap->a_vp; 5737 struct knote *kn = ap->a_kn; 5738 struct knlist *knl; 5739 5740 switch (kn->kn_filter) { 5741 case EVFILT_READ: 5742 kn->kn_fop = &vfsread_filtops; 5743 break; 5744 case EVFILT_WRITE: 5745 kn->kn_fop = &vfswrite_filtops; 5746 break; 5747 case EVFILT_VNODE: 5748 kn->kn_fop = &vfsvnode_filtops; 5749 break; 5750 default: 5751 return (EINVAL); 5752 } 5753 5754 kn->kn_hook = (caddr_t)vp; 5755 5756 v_addpollinfo(vp); 5757 if (vp->v_pollinfo == NULL) 5758 return (ENOMEM); 5759 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5760 vhold(vp); 5761 knlist_add(knl, kn, 0); 5762 5763 return (0); 5764 } 5765 5766 /* 5767 * Detach knote from vnode 5768 */ 5769 static void 5770 filt_vfsdetach(struct knote *kn) 5771 { 5772 struct vnode *vp = (struct vnode *)kn->kn_hook; 5773 5774 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5775 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5776 vdrop(vp); 5777 } 5778 5779 /*ARGSUSED*/ 5780 static int 5781 filt_vfsread(struct knote *kn, long hint) 5782 { 5783 struct vnode *vp = (struct vnode *)kn->kn_hook; 5784 struct vattr va; 5785 int res; 5786 5787 /* 5788 * filesystem is gone, so set the EOF flag and schedule 5789 * the knote for deletion. 5790 */ 5791 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5792 VI_LOCK(vp); 5793 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5794 VI_UNLOCK(vp); 5795 return (1); 5796 } 5797 5798 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5799 return (0); 5800 5801 VI_LOCK(vp); 5802 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5803 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5804 VI_UNLOCK(vp); 5805 return (res); 5806 } 5807 5808 /*ARGSUSED*/ 5809 static int 5810 filt_vfswrite(struct knote *kn, long hint) 5811 { 5812 struct vnode *vp = (struct vnode *)kn->kn_hook; 5813 5814 VI_LOCK(vp); 5815 5816 /* 5817 * filesystem is gone, so set the EOF flag and schedule 5818 * the knote for deletion. 5819 */ 5820 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5821 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5822 5823 kn->kn_data = 0; 5824 VI_UNLOCK(vp); 5825 return (1); 5826 } 5827 5828 static int 5829 filt_vfsvnode(struct knote *kn, long hint) 5830 { 5831 struct vnode *vp = (struct vnode *)kn->kn_hook; 5832 int res; 5833 5834 VI_LOCK(vp); 5835 if (kn->kn_sfflags & hint) 5836 kn->kn_fflags |= hint; 5837 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5838 kn->kn_flags |= EV_EOF; 5839 VI_UNLOCK(vp); 5840 return (1); 5841 } 5842 res = (kn->kn_fflags != 0); 5843 VI_UNLOCK(vp); 5844 return (res); 5845 } 5846 5847 /* 5848 * Returns whether the directory is empty or not. 5849 * If it is empty, the return value is 0; otherwise 5850 * the return value is an error value (which may 5851 * be ENOTEMPTY). 5852 */ 5853 int 5854 vfs_emptydir(struct vnode *vp) 5855 { 5856 struct uio uio; 5857 struct iovec iov; 5858 struct dirent *dirent, *dp, *endp; 5859 int error, eof; 5860 5861 error = 0; 5862 eof = 0; 5863 5864 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 5865 5866 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 5867 iov.iov_base = dirent; 5868 iov.iov_len = sizeof(struct dirent); 5869 5870 uio.uio_iov = &iov; 5871 uio.uio_iovcnt = 1; 5872 uio.uio_offset = 0; 5873 uio.uio_resid = sizeof(struct dirent); 5874 uio.uio_segflg = UIO_SYSSPACE; 5875 uio.uio_rw = UIO_READ; 5876 uio.uio_td = curthread; 5877 5878 while (eof == 0 && error == 0) { 5879 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 5880 NULL, NULL); 5881 if (error != 0) 5882 break; 5883 endp = (void *)((uint8_t *)dirent + 5884 sizeof(struct dirent) - uio.uio_resid); 5885 for (dp = dirent; dp < endp; 5886 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 5887 if (dp->d_type == DT_WHT) 5888 continue; 5889 if (dp->d_namlen == 0) 5890 continue; 5891 if (dp->d_type != DT_DIR && 5892 dp->d_type != DT_UNKNOWN) { 5893 error = ENOTEMPTY; 5894 break; 5895 } 5896 if (dp->d_namlen > 2) { 5897 error = ENOTEMPTY; 5898 break; 5899 } 5900 if (dp->d_namlen == 1 && 5901 dp->d_name[0] != '.') { 5902 error = ENOTEMPTY; 5903 break; 5904 } 5905 if (dp->d_namlen == 2 && 5906 dp->d_name[1] != '.') { 5907 error = ENOTEMPTY; 5908 break; 5909 } 5910 uio.uio_resid = sizeof(struct dirent); 5911 } 5912 } 5913 free(dirent, M_TEMP); 5914 return (error); 5915 } 5916 5917 int 5918 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5919 { 5920 int error; 5921 5922 if (dp->d_reclen > ap->a_uio->uio_resid) 5923 return (ENAMETOOLONG); 5924 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5925 if (error) { 5926 if (ap->a_ncookies != NULL) { 5927 if (ap->a_cookies != NULL) 5928 free(ap->a_cookies, M_TEMP); 5929 ap->a_cookies = NULL; 5930 *ap->a_ncookies = 0; 5931 } 5932 return (error); 5933 } 5934 if (ap->a_ncookies == NULL) 5935 return (0); 5936 5937 KASSERT(ap->a_cookies, 5938 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5939 5940 *ap->a_cookies = realloc(*ap->a_cookies, 5941 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5942 (*ap->a_cookies)[*ap->a_ncookies] = off; 5943 *ap->a_ncookies += 1; 5944 return (0); 5945 } 5946 5947 /* 5948 * Mark for update the access time of the file if the filesystem 5949 * supports VOP_MARKATIME. This functionality is used by execve and 5950 * mmap, so we want to avoid the I/O implied by directly setting 5951 * va_atime for the sake of efficiency. 5952 */ 5953 void 5954 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5955 { 5956 struct mount *mp; 5957 5958 mp = vp->v_mount; 5959 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5960 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5961 (void)VOP_MARKATIME(vp); 5962 } 5963 5964 /* 5965 * The purpose of this routine is to remove granularity from accmode_t, 5966 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5967 * VADMIN and VAPPEND. 5968 * 5969 * If it returns 0, the caller is supposed to continue with the usual 5970 * access checks using 'accmode' as modified by this routine. If it 5971 * returns nonzero value, the caller is supposed to return that value 5972 * as errno. 5973 * 5974 * Note that after this routine runs, accmode may be zero. 5975 */ 5976 int 5977 vfs_unixify_accmode(accmode_t *accmode) 5978 { 5979 /* 5980 * There is no way to specify explicit "deny" rule using 5981 * file mode or POSIX.1e ACLs. 5982 */ 5983 if (*accmode & VEXPLICIT_DENY) { 5984 *accmode = 0; 5985 return (0); 5986 } 5987 5988 /* 5989 * None of these can be translated into usual access bits. 5990 * Also, the common case for NFSv4 ACLs is to not contain 5991 * either of these bits. Caller should check for VWRITE 5992 * on the containing directory instead. 5993 */ 5994 if (*accmode & (VDELETE_CHILD | VDELETE)) 5995 return (EPERM); 5996 5997 if (*accmode & VADMIN_PERMS) { 5998 *accmode &= ~VADMIN_PERMS; 5999 *accmode |= VADMIN; 6000 } 6001 6002 /* 6003 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6004 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6005 */ 6006 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6007 6008 return (0); 6009 } 6010 6011 /* 6012 * Clear out a doomed vnode (if any) and replace it with a new one as long 6013 * as the fs is not being unmounted. Return the root vnode to the caller. 6014 */ 6015 static int __noinline 6016 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6017 { 6018 struct vnode *vp; 6019 int error; 6020 6021 restart: 6022 if (mp->mnt_rootvnode != NULL) { 6023 MNT_ILOCK(mp); 6024 vp = mp->mnt_rootvnode; 6025 if (vp != NULL) { 6026 if (!VN_IS_DOOMED(vp)) { 6027 vrefact(vp); 6028 MNT_IUNLOCK(mp); 6029 error = vn_lock(vp, flags); 6030 if (error == 0) { 6031 *vpp = vp; 6032 return (0); 6033 } 6034 vrele(vp); 6035 goto restart; 6036 } 6037 /* 6038 * Clear the old one. 6039 */ 6040 mp->mnt_rootvnode = NULL; 6041 } 6042 MNT_IUNLOCK(mp); 6043 if (vp != NULL) { 6044 /* 6045 * Paired with a fence in vfs_op_thread_exit(). 6046 */ 6047 atomic_thread_fence_acq(); 6048 vfs_op_barrier_wait(mp); 6049 vrele(vp); 6050 } 6051 } 6052 error = VFS_CACHEDROOT(mp, flags, vpp); 6053 if (error != 0) 6054 return (error); 6055 if (mp->mnt_vfs_ops == 0) { 6056 MNT_ILOCK(mp); 6057 if (mp->mnt_vfs_ops != 0) { 6058 MNT_IUNLOCK(mp); 6059 return (0); 6060 } 6061 if (mp->mnt_rootvnode == NULL) { 6062 vrefact(*vpp); 6063 mp->mnt_rootvnode = *vpp; 6064 } else { 6065 if (mp->mnt_rootvnode != *vpp) { 6066 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6067 panic("%s: mismatch between vnode returned " 6068 " by VFS_CACHEDROOT and the one cached " 6069 " (%p != %p)", 6070 __func__, *vpp, mp->mnt_rootvnode); 6071 } 6072 } 6073 } 6074 MNT_IUNLOCK(mp); 6075 } 6076 return (0); 6077 } 6078 6079 int 6080 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6081 { 6082 struct vnode *vp; 6083 int error; 6084 6085 if (!vfs_op_thread_enter(mp)) 6086 return (vfs_cache_root_fallback(mp, flags, vpp)); 6087 vp = (struct vnode *)atomic_load_ptr(&mp->mnt_rootvnode); 6088 if (vp == NULL || VN_IS_DOOMED(vp)) { 6089 vfs_op_thread_exit(mp); 6090 return (vfs_cache_root_fallback(mp, flags, vpp)); 6091 } 6092 vrefact(vp); 6093 vfs_op_thread_exit(mp); 6094 error = vn_lock(vp, flags); 6095 if (error != 0) { 6096 vrele(vp); 6097 return (vfs_cache_root_fallback(mp, flags, vpp)); 6098 } 6099 *vpp = vp; 6100 return (0); 6101 } 6102 6103 struct vnode * 6104 vfs_cache_root_clear(struct mount *mp) 6105 { 6106 struct vnode *vp; 6107 6108 /* 6109 * ops > 0 guarantees there is nobody who can see this vnode 6110 */ 6111 MPASS(mp->mnt_vfs_ops > 0); 6112 vp = mp->mnt_rootvnode; 6113 mp->mnt_rootvnode = NULL; 6114 return (vp); 6115 } 6116 6117 void 6118 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6119 { 6120 6121 MPASS(mp->mnt_vfs_ops > 0); 6122 vrefact(vp); 6123 mp->mnt_rootvnode = vp; 6124 } 6125 6126 /* 6127 * These are helper functions for filesystems to traverse all 6128 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6129 * 6130 * This interface replaces MNT_VNODE_FOREACH. 6131 */ 6132 6133 6134 struct vnode * 6135 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6136 { 6137 struct vnode *vp; 6138 6139 if (should_yield()) 6140 kern_yield(PRI_USER); 6141 MNT_ILOCK(mp); 6142 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6143 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6144 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6145 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6146 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6147 continue; 6148 VI_LOCK(vp); 6149 if (VN_IS_DOOMED(vp)) { 6150 VI_UNLOCK(vp); 6151 continue; 6152 } 6153 break; 6154 } 6155 if (vp == NULL) { 6156 __mnt_vnode_markerfree_all(mvp, mp); 6157 /* MNT_IUNLOCK(mp); -- done in above function */ 6158 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6159 return (NULL); 6160 } 6161 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6162 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6163 MNT_IUNLOCK(mp); 6164 return (vp); 6165 } 6166 6167 struct vnode * 6168 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6169 { 6170 struct vnode *vp; 6171 6172 *mvp = vn_alloc_marker(mp); 6173 MNT_ILOCK(mp); 6174 MNT_REF(mp); 6175 6176 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6177 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6178 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6179 continue; 6180 VI_LOCK(vp); 6181 if (VN_IS_DOOMED(vp)) { 6182 VI_UNLOCK(vp); 6183 continue; 6184 } 6185 break; 6186 } 6187 if (vp == NULL) { 6188 MNT_REL(mp); 6189 MNT_IUNLOCK(mp); 6190 vn_free_marker(*mvp); 6191 *mvp = NULL; 6192 return (NULL); 6193 } 6194 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6195 MNT_IUNLOCK(mp); 6196 return (vp); 6197 } 6198 6199 void 6200 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6201 { 6202 6203 if (*mvp == NULL) { 6204 MNT_IUNLOCK(mp); 6205 return; 6206 } 6207 6208 mtx_assert(MNT_MTX(mp), MA_OWNED); 6209 6210 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6211 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6212 MNT_REL(mp); 6213 MNT_IUNLOCK(mp); 6214 vn_free_marker(*mvp); 6215 *mvp = NULL; 6216 } 6217 6218 /* 6219 * These are helper functions for filesystems to traverse their 6220 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6221 */ 6222 static void 6223 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6224 { 6225 6226 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6227 6228 MNT_ILOCK(mp); 6229 MNT_REL(mp); 6230 MNT_IUNLOCK(mp); 6231 vn_free_marker(*mvp); 6232 *mvp = NULL; 6233 } 6234 6235 /* 6236 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6237 * conventional lock order during mnt_vnode_next_lazy iteration. 6238 * 6239 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6240 * The list lock is dropped and reacquired. On success, both locks are held. 6241 * On failure, the mount vnode list lock is held but the vnode interlock is 6242 * not, and the procedure may have yielded. 6243 */ 6244 static bool 6245 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6246 struct vnode *vp) 6247 { 6248 6249 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6250 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6251 ("%s: bad marker", __func__)); 6252 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6253 ("%s: inappropriate vnode", __func__)); 6254 ASSERT_VI_UNLOCKED(vp, __func__); 6255 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6256 6257 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6258 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6259 6260 vholdnz(vp); 6261 mtx_unlock(&mp->mnt_listmtx); 6262 VI_LOCK(vp); 6263 if (VN_IS_DOOMED(vp)) { 6264 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6265 goto out_lost; 6266 } 6267 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6268 /* 6269 * Since we had a period with no locks held we may be the last 6270 * remaining user, in which case there is nothing to do. 6271 */ 6272 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6273 goto out_lost; 6274 mtx_lock(&mp->mnt_listmtx); 6275 return (true); 6276 out_lost: 6277 vdropl(vp); 6278 maybe_yield(); 6279 mtx_lock(&mp->mnt_listmtx); 6280 return (false); 6281 } 6282 6283 static struct vnode * 6284 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6285 void *cbarg) 6286 { 6287 struct vnode *vp; 6288 6289 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6290 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6291 restart: 6292 vp = TAILQ_NEXT(*mvp, v_lazylist); 6293 while (vp != NULL) { 6294 if (vp->v_type == VMARKER) { 6295 vp = TAILQ_NEXT(vp, v_lazylist); 6296 continue; 6297 } 6298 /* 6299 * See if we want to process the vnode. Note we may encounter a 6300 * long string of vnodes we don't care about and hog the list 6301 * as a result. Check for it and requeue the marker. 6302 */ 6303 VNPASS(!VN_IS_DOOMED(vp), vp); 6304 if (!cb(vp, cbarg)) { 6305 if (!should_yield()) { 6306 vp = TAILQ_NEXT(vp, v_lazylist); 6307 continue; 6308 } 6309 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 6310 v_lazylist); 6311 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 6312 v_lazylist); 6313 mtx_unlock(&mp->mnt_listmtx); 6314 kern_yield(PRI_USER); 6315 mtx_lock(&mp->mnt_listmtx); 6316 goto restart; 6317 } 6318 /* 6319 * Try-lock because this is the wrong lock order. 6320 */ 6321 if (!VI_TRYLOCK(vp) && 6322 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 6323 goto restart; 6324 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 6325 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 6326 ("alien vnode on the lazy list %p %p", vp, mp)); 6327 VNPASS(vp->v_mount == mp, vp); 6328 VNPASS(!VN_IS_DOOMED(vp), vp); 6329 break; 6330 } 6331 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6332 6333 /* Check if we are done */ 6334 if (vp == NULL) { 6335 mtx_unlock(&mp->mnt_listmtx); 6336 mnt_vnode_markerfree_lazy(mvp, mp); 6337 return (NULL); 6338 } 6339 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 6340 mtx_unlock(&mp->mnt_listmtx); 6341 ASSERT_VI_LOCKED(vp, "lazy iter"); 6342 return (vp); 6343 } 6344 6345 struct vnode * 6346 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6347 void *cbarg) 6348 { 6349 6350 if (should_yield()) 6351 kern_yield(PRI_USER); 6352 mtx_lock(&mp->mnt_listmtx); 6353 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6354 } 6355 6356 struct vnode * 6357 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6358 void *cbarg) 6359 { 6360 struct vnode *vp; 6361 6362 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 6363 return (NULL); 6364 6365 *mvp = vn_alloc_marker(mp); 6366 MNT_ILOCK(mp); 6367 MNT_REF(mp); 6368 MNT_IUNLOCK(mp); 6369 6370 mtx_lock(&mp->mnt_listmtx); 6371 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 6372 if (vp == NULL) { 6373 mtx_unlock(&mp->mnt_listmtx); 6374 mnt_vnode_markerfree_lazy(mvp, mp); 6375 return (NULL); 6376 } 6377 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 6378 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6379 } 6380 6381 void 6382 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6383 { 6384 6385 if (*mvp == NULL) 6386 return; 6387 6388 mtx_lock(&mp->mnt_listmtx); 6389 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6390 mtx_unlock(&mp->mnt_listmtx); 6391 mnt_vnode_markerfree_lazy(mvp, mp); 6392 } 6393