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