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); 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 struct vm_object *object; 1104 u_long done; 1105 bool retried; 1106 1107 mtx_assert(&vnode_list_mtx, MA_OWNED); 1108 1109 retried = false; 1110 done = 0; 1111 1112 mvp = vnode_list_reclaim_marker; 1113 restart: 1114 vp = mvp; 1115 while (done < target) { 1116 vp = TAILQ_NEXT(vp, v_vnodelist); 1117 if (__predict_false(vp == NULL)) 1118 break; 1119 1120 if (__predict_false(vp->v_type == VMARKER)) 1121 continue; 1122 1123 /* 1124 * If it's been deconstructed already, it's still 1125 * referenced, or it exceeds the trigger, skip it. 1126 * Also skip free vnodes. We are trying to make space 1127 * to expand the free list, not reduce it. 1128 */ 1129 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1130 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src))) 1131 goto next_iter; 1132 1133 if (vp->v_type == VBAD || vp->v_type == VNON) 1134 goto next_iter; 1135 1136 if (!VI_TRYLOCK(vp)) 1137 goto next_iter; 1138 1139 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1140 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1141 VN_IS_DOOMED(vp) || vp->v_type == VNON) { 1142 VI_UNLOCK(vp); 1143 goto next_iter; 1144 } 1145 1146 object = atomic_load_ptr(&vp->v_object); 1147 if (object == NULL || object->resident_page_count > trigger) { 1148 VI_UNLOCK(vp); 1149 goto next_iter; 1150 } 1151 1152 vholdl(vp); 1153 VI_UNLOCK(vp); 1154 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1155 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1156 mtx_unlock(&vnode_list_mtx); 1157 1158 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1159 vdrop(vp); 1160 goto next_iter_unlocked; 1161 } 1162 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { 1163 vdrop(vp); 1164 vn_finished_write(mp); 1165 goto next_iter_unlocked; 1166 } 1167 1168 VI_LOCK(vp); 1169 if (vp->v_usecount > 0 || 1170 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1171 (vp->v_object != NULL && 1172 vp->v_object->resident_page_count > trigger)) { 1173 VOP_UNLOCK(vp); 1174 vdropl(vp); 1175 vn_finished_write(mp); 1176 goto next_iter_unlocked; 1177 } 1178 counter_u64_add(recycles_count, 1); 1179 vgonel(vp); 1180 VOP_UNLOCK(vp); 1181 vdropl(vp); 1182 vn_finished_write(mp); 1183 done++; 1184 next_iter_unlocked: 1185 if (should_yield()) 1186 kern_yield(PRI_USER); 1187 mtx_lock(&vnode_list_mtx); 1188 goto restart; 1189 next_iter: 1190 MPASS(vp->v_type != VMARKER); 1191 if (!should_yield()) 1192 continue; 1193 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1194 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1195 mtx_unlock(&vnode_list_mtx); 1196 kern_yield(PRI_USER); 1197 mtx_lock(&vnode_list_mtx); 1198 goto restart; 1199 } 1200 if (done == 0 && !retried) { 1201 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1202 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1203 retried = true; 1204 goto restart; 1205 } 1206 return (done); 1207 } 1208 1209 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1210 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1211 0, 1212 "limit on vnode free requests per call to the vnlru_free routine"); 1213 1214 /* 1215 * Attempt to reduce the free list by the requested amount. 1216 */ 1217 static int 1218 vnlru_free_locked(int count, struct vfsops *mnt_op) 1219 { 1220 struct vnode *vp, *mvp; 1221 struct mount *mp; 1222 int ocount; 1223 1224 mtx_assert(&vnode_list_mtx, MA_OWNED); 1225 if (count > max_vnlru_free) 1226 count = max_vnlru_free; 1227 ocount = count; 1228 mvp = vnode_list_free_marker; 1229 restart: 1230 vp = mvp; 1231 while (count > 0) { 1232 vp = TAILQ_NEXT(vp, v_vnodelist); 1233 if (__predict_false(vp == NULL)) { 1234 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1235 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist); 1236 break; 1237 } 1238 if (__predict_false(vp->v_type == VMARKER)) 1239 continue; 1240 1241 /* 1242 * Don't recycle if our vnode is from different type 1243 * of mount point. Note that mp is type-safe, the 1244 * check does not reach unmapped address even if 1245 * vnode is reclaimed. 1246 * Don't recycle if we can't get the interlock without 1247 * blocking. 1248 */ 1249 if (vp->v_holdcnt > 0 || (mnt_op != NULL && (mp = vp->v_mount) != NULL && 1250 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1251 continue; 1252 } 1253 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1254 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1255 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1256 VI_UNLOCK(vp); 1257 continue; 1258 } 1259 vholdl(vp); 1260 count--; 1261 mtx_unlock(&vnode_list_mtx); 1262 VI_UNLOCK(vp); 1263 vtryrecycle(vp); 1264 vdrop(vp); 1265 mtx_lock(&vnode_list_mtx); 1266 goto restart; 1267 } 1268 return (ocount - count); 1269 } 1270 1271 void 1272 vnlru_free(int count, struct vfsops *mnt_op) 1273 { 1274 1275 mtx_lock(&vnode_list_mtx); 1276 vnlru_free_locked(count, mnt_op); 1277 mtx_unlock(&vnode_list_mtx); 1278 } 1279 1280 static void 1281 vnlru_recalc(void) 1282 { 1283 1284 mtx_assert(&vnode_list_mtx, MA_OWNED); 1285 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1286 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1287 vlowat = vhiwat / 2; 1288 } 1289 1290 /* 1291 * Attempt to recycle vnodes in a context that is always safe to block. 1292 * Calling vlrurecycle() from the bowels of filesystem code has some 1293 * interesting deadlock problems. 1294 */ 1295 static struct proc *vnlruproc; 1296 static int vnlruproc_sig; 1297 1298 /* 1299 * The main freevnodes counter is only updated when threads requeue their vnode 1300 * batches. CPUs are conditionally walked to compute a more accurate total. 1301 * 1302 * Limit how much of a slop are we willing to tolerate. Note: the actual value 1303 * at any given moment can still exceed slop, but it should not be by significant 1304 * margin in practice. 1305 */ 1306 #define VNLRU_FREEVNODES_SLOP 128 1307 1308 static u_long 1309 vnlru_read_freevnodes(void) 1310 { 1311 struct vdbatch *vd; 1312 long slop; 1313 int cpu; 1314 1315 mtx_assert(&vnode_list_mtx, MA_OWNED); 1316 if (freevnodes > freevnodes_old) 1317 slop = freevnodes - freevnodes_old; 1318 else 1319 slop = freevnodes_old - freevnodes; 1320 if (slop < VNLRU_FREEVNODES_SLOP) 1321 return (freevnodes >= 0 ? freevnodes : 0); 1322 freevnodes_old = freevnodes; 1323 CPU_FOREACH(cpu) { 1324 vd = DPCPU_ID_PTR((cpu), vd); 1325 freevnodes_old += vd->freevnodes; 1326 } 1327 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1328 } 1329 1330 static bool 1331 vnlru_under(u_long rnumvnodes, u_long limit) 1332 { 1333 u_long rfreevnodes, space; 1334 1335 if (__predict_false(rnumvnodes > desiredvnodes)) 1336 return (true); 1337 1338 space = desiredvnodes - rnumvnodes; 1339 if (space < limit) { 1340 rfreevnodes = vnlru_read_freevnodes(); 1341 if (rfreevnodes > wantfreevnodes) 1342 space += rfreevnodes - wantfreevnodes; 1343 } 1344 return (space < limit); 1345 } 1346 1347 static bool 1348 vnlru_under_unlocked(u_long rnumvnodes, u_long limit) 1349 { 1350 long rfreevnodes, space; 1351 1352 if (__predict_false(rnumvnodes > desiredvnodes)) 1353 return (true); 1354 1355 space = desiredvnodes - rnumvnodes; 1356 if (space < limit) { 1357 rfreevnodes = atomic_load_long(&freevnodes); 1358 if (rfreevnodes > wantfreevnodes) 1359 space += rfreevnodes - wantfreevnodes; 1360 } 1361 return (space < limit); 1362 } 1363 1364 static void 1365 vnlru_kick(void) 1366 { 1367 1368 mtx_assert(&vnode_list_mtx, MA_OWNED); 1369 if (vnlruproc_sig == 0) { 1370 vnlruproc_sig = 1; 1371 wakeup(vnlruproc); 1372 } 1373 } 1374 1375 static void 1376 vnlru_proc(void) 1377 { 1378 u_long rnumvnodes, rfreevnodes, target; 1379 unsigned long onumvnodes; 1380 int done, force, trigger, usevnodes; 1381 bool reclaim_nc_src, want_reread; 1382 1383 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1384 SHUTDOWN_PRI_FIRST); 1385 1386 force = 0; 1387 want_reread = false; 1388 for (;;) { 1389 kproc_suspend_check(vnlruproc); 1390 mtx_lock(&vnode_list_mtx); 1391 rnumvnodes = atomic_load_long(&numvnodes); 1392 1393 if (want_reread) { 1394 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1395 want_reread = false; 1396 } 1397 1398 /* 1399 * If numvnodes is too large (due to desiredvnodes being 1400 * adjusted using its sysctl, or emergency growth), first 1401 * try to reduce it by discarding from the free list. 1402 */ 1403 if (rnumvnodes > desiredvnodes) { 1404 vnlru_free_locked(rnumvnodes - desiredvnodes, NULL); 1405 rnumvnodes = atomic_load_long(&numvnodes); 1406 } 1407 /* 1408 * Sleep if the vnode cache is in a good state. This is 1409 * when it is not over-full and has space for about a 4% 1410 * or 9% expansion (by growing its size or inexcessively 1411 * reducing its free list). Otherwise, try to reclaim 1412 * space for a 10% expansion. 1413 */ 1414 if (vstir && force == 0) { 1415 force = 1; 1416 vstir = 0; 1417 } 1418 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1419 vnlruproc_sig = 0; 1420 wakeup(&vnlruproc_sig); 1421 msleep(vnlruproc, &vnode_list_mtx, 1422 PVFS|PDROP, "vlruwt", hz); 1423 continue; 1424 } 1425 rfreevnodes = vnlru_read_freevnodes(); 1426 1427 onumvnodes = rnumvnodes; 1428 /* 1429 * Calculate parameters for recycling. These are the same 1430 * throughout the loop to give some semblance of fairness. 1431 * The trigger point is to avoid recycling vnodes with lots 1432 * of resident pages. We aren't trying to free memory; we 1433 * are trying to recycle or at least free vnodes. 1434 */ 1435 if (rnumvnodes <= desiredvnodes) 1436 usevnodes = rnumvnodes - rfreevnodes; 1437 else 1438 usevnodes = rnumvnodes; 1439 if (usevnodes <= 0) 1440 usevnodes = 1; 1441 /* 1442 * The trigger value is is chosen to give a conservatively 1443 * large value to ensure that it alone doesn't prevent 1444 * making progress. The value can easily be so large that 1445 * it is effectively infinite in some congested and 1446 * misconfigured cases, and this is necessary. Normally 1447 * it is about 8 to 100 (pages), which is quite large. 1448 */ 1449 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1450 if (force < 2) 1451 trigger = vsmalltrigger; 1452 reclaim_nc_src = force >= 3; 1453 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1454 target = target / 10 + 1; 1455 done = vlrureclaim(reclaim_nc_src, trigger, target); 1456 mtx_unlock(&vnode_list_mtx); 1457 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1458 uma_reclaim(UMA_RECLAIM_DRAIN); 1459 if (done == 0) { 1460 if (force == 0 || force == 1) { 1461 force = 2; 1462 continue; 1463 } 1464 if (force == 2) { 1465 force = 3; 1466 continue; 1467 } 1468 want_reread = true; 1469 force = 0; 1470 vnlru_nowhere++; 1471 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1472 } else { 1473 want_reread = true; 1474 kern_yield(PRI_USER); 1475 } 1476 } 1477 } 1478 1479 static struct kproc_desc vnlru_kp = { 1480 "vnlru", 1481 vnlru_proc, 1482 &vnlruproc 1483 }; 1484 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1485 &vnlru_kp); 1486 1487 /* 1488 * Routines having to do with the management of the vnode table. 1489 */ 1490 1491 /* 1492 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1493 * before we actually vgone(). This function must be called with the vnode 1494 * held to prevent the vnode from being returned to the free list midway 1495 * through vgone(). 1496 */ 1497 static int 1498 vtryrecycle(struct vnode *vp) 1499 { 1500 struct mount *vnmp; 1501 1502 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1503 VNASSERT(vp->v_holdcnt, vp, 1504 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1505 /* 1506 * This vnode may found and locked via some other list, if so we 1507 * can't recycle it yet. 1508 */ 1509 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1510 CTR2(KTR_VFS, 1511 "%s: impossible to recycle, vp %p lock is already held", 1512 __func__, vp); 1513 return (EWOULDBLOCK); 1514 } 1515 /* 1516 * Don't recycle if its filesystem is being suspended. 1517 */ 1518 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1519 VOP_UNLOCK(vp); 1520 CTR2(KTR_VFS, 1521 "%s: impossible to recycle, cannot start the write for %p", 1522 __func__, vp); 1523 return (EBUSY); 1524 } 1525 /* 1526 * If we got this far, we need to acquire the interlock and see if 1527 * anyone picked up this vnode from another list. If not, we will 1528 * mark it with DOOMED via vgonel() so that anyone who does find it 1529 * will skip over it. 1530 */ 1531 VI_LOCK(vp); 1532 if (vp->v_usecount) { 1533 VOP_UNLOCK(vp); 1534 VI_UNLOCK(vp); 1535 vn_finished_write(vnmp); 1536 CTR2(KTR_VFS, 1537 "%s: impossible to recycle, %p is already referenced", 1538 __func__, vp); 1539 return (EBUSY); 1540 } 1541 if (!VN_IS_DOOMED(vp)) { 1542 counter_u64_add(recycles_free_count, 1); 1543 vgonel(vp); 1544 } 1545 VOP_UNLOCK(vp); 1546 VI_UNLOCK(vp); 1547 vn_finished_write(vnmp); 1548 return (0); 1549 } 1550 1551 /* 1552 * Allocate a new vnode. 1553 * 1554 * The operation never returns an error. Returning an error was disabled 1555 * in r145385 (dated 2005) with the following comment: 1556 * 1557 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1558 * 1559 * Given the age of this commit (almost 15 years at the time of writing this 1560 * comment) restoring the ability to fail requires a significant audit of 1561 * all codepaths. 1562 * 1563 * The routine can try to free a vnode or stall for up to 1 second waiting for 1564 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1565 */ 1566 static u_long vn_alloc_cyclecount; 1567 1568 static struct vnode * __noinline 1569 vn_alloc_hard(struct mount *mp) 1570 { 1571 u_long rnumvnodes, rfreevnodes; 1572 1573 mtx_lock(&vnode_list_mtx); 1574 rnumvnodes = atomic_load_long(&numvnodes); 1575 if (rnumvnodes + 1 < desiredvnodes) { 1576 vn_alloc_cyclecount = 0; 1577 goto alloc; 1578 } 1579 rfreevnodes = vnlru_read_freevnodes(); 1580 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1581 vn_alloc_cyclecount = 0; 1582 vstir = 1; 1583 } 1584 /* 1585 * Grow the vnode cache if it will not be above its target max 1586 * after growing. Otherwise, if the free list is nonempty, try 1587 * to reclaim 1 item from it before growing the cache (possibly 1588 * above its target max if the reclamation failed or is delayed). 1589 * Otherwise, wait for some space. In all cases, schedule 1590 * vnlru_proc() if we are getting short of space. The watermarks 1591 * should be chosen so that we never wait or even reclaim from 1592 * the free list to below its target minimum. 1593 */ 1594 if (vnlru_free_locked(1, NULL) > 0) 1595 goto alloc; 1596 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1597 /* 1598 * Wait for space for a new vnode. 1599 */ 1600 vnlru_kick(); 1601 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1602 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1603 vnlru_read_freevnodes() > 1) 1604 vnlru_free_locked(1, NULL); 1605 } 1606 alloc: 1607 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1608 if (vnlru_under(rnumvnodes, vlowat)) 1609 vnlru_kick(); 1610 mtx_unlock(&vnode_list_mtx); 1611 return (uma_zalloc(vnode_zone, M_WAITOK)); 1612 } 1613 1614 static struct vnode * 1615 vn_alloc(struct mount *mp) 1616 { 1617 u_long rnumvnodes; 1618 1619 if (__predict_false(vn_alloc_cyclecount != 0)) 1620 return (vn_alloc_hard(mp)); 1621 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1622 if (__predict_false(vnlru_under_unlocked(rnumvnodes, vlowat))) { 1623 atomic_subtract_long(&numvnodes, 1); 1624 return (vn_alloc_hard(mp)); 1625 } 1626 1627 return (uma_zalloc(vnode_zone, M_WAITOK)); 1628 } 1629 1630 static void 1631 vn_free(struct vnode *vp) 1632 { 1633 1634 atomic_subtract_long(&numvnodes, 1); 1635 uma_zfree(vnode_zone, vp); 1636 } 1637 1638 /* 1639 * Return the next vnode from the free list. 1640 */ 1641 int 1642 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1643 struct vnode **vpp) 1644 { 1645 struct vnode *vp; 1646 struct thread *td; 1647 struct lock_object *lo; 1648 1649 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1650 1651 KASSERT(vops->registered, 1652 ("%s: not registered vector op %p\n", __func__, vops)); 1653 1654 td = curthread; 1655 if (td->td_vp_reserved != NULL) { 1656 vp = td->td_vp_reserved; 1657 td->td_vp_reserved = NULL; 1658 } else { 1659 vp = vn_alloc(mp); 1660 } 1661 counter_u64_add(vnodes_created, 1); 1662 /* 1663 * Locks are given the generic name "vnode" when created. 1664 * Follow the historic practice of using the filesystem 1665 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1666 * 1667 * Locks live in a witness group keyed on their name. Thus, 1668 * when a lock is renamed, it must also move from the witness 1669 * group of its old name to the witness group of its new name. 1670 * 1671 * The change only needs to be made when the vnode moves 1672 * from one filesystem type to another. We ensure that each 1673 * filesystem use a single static name pointer for its tag so 1674 * that we can compare pointers rather than doing a strcmp(). 1675 */ 1676 lo = &vp->v_vnlock->lock_object; 1677 #ifdef WITNESS 1678 if (lo->lo_name != tag) { 1679 #endif 1680 lo->lo_name = tag; 1681 #ifdef WITNESS 1682 WITNESS_DESTROY(lo); 1683 WITNESS_INIT(lo, tag); 1684 } 1685 #endif 1686 /* 1687 * By default, don't allow shared locks unless filesystems opt-in. 1688 */ 1689 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1690 /* 1691 * Finalize various vnode identity bits. 1692 */ 1693 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1694 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1695 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1696 vp->v_type = VNON; 1697 vp->v_op = vops; 1698 v_init_counters(vp); 1699 vp->v_bufobj.bo_ops = &buf_ops_bio; 1700 #ifdef DIAGNOSTIC 1701 if (mp == NULL && vops != &dead_vnodeops) 1702 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1703 #endif 1704 #ifdef MAC 1705 mac_vnode_init(vp); 1706 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1707 mac_vnode_associate_singlelabel(mp, vp); 1708 #endif 1709 if (mp != NULL) { 1710 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1711 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1712 vp->v_vflag |= VV_NOKNOTE; 1713 } 1714 1715 /* 1716 * For the filesystems which do not use vfs_hash_insert(), 1717 * still initialize v_hash to have vfs_hash_index() useful. 1718 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1719 * its own hashing. 1720 */ 1721 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1722 1723 *vpp = vp; 1724 return (0); 1725 } 1726 1727 void 1728 getnewvnode_reserve(void) 1729 { 1730 struct thread *td; 1731 1732 td = curthread; 1733 MPASS(td->td_vp_reserved == NULL); 1734 td->td_vp_reserved = vn_alloc(NULL); 1735 } 1736 1737 void 1738 getnewvnode_drop_reserve(void) 1739 { 1740 struct thread *td; 1741 1742 td = curthread; 1743 if (td->td_vp_reserved != NULL) { 1744 vn_free(td->td_vp_reserved); 1745 td->td_vp_reserved = NULL; 1746 } 1747 } 1748 1749 static void 1750 freevnode(struct vnode *vp) 1751 { 1752 struct bufobj *bo; 1753 1754 /* 1755 * The vnode has been marked for destruction, so free it. 1756 * 1757 * The vnode will be returned to the zone where it will 1758 * normally remain until it is needed for another vnode. We 1759 * need to cleanup (or verify that the cleanup has already 1760 * been done) any residual data left from its current use 1761 * so as not to contaminate the freshly allocated vnode. 1762 */ 1763 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1764 bo = &vp->v_bufobj; 1765 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1766 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 1767 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1768 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1769 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1770 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1771 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1772 ("clean blk trie not empty")); 1773 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1774 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1775 ("dirty blk trie not empty")); 1776 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1777 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1778 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1779 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1780 ("Dangling rangelock waiters")); 1781 VI_UNLOCK(vp); 1782 #ifdef MAC 1783 mac_vnode_destroy(vp); 1784 #endif 1785 if (vp->v_pollinfo != NULL) { 1786 destroy_vpollinfo(vp->v_pollinfo); 1787 vp->v_pollinfo = NULL; 1788 } 1789 #ifdef INVARIANTS 1790 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1791 vp->v_op = NULL; 1792 #endif 1793 vp->v_mountedhere = NULL; 1794 vp->v_unpcb = NULL; 1795 vp->v_rdev = NULL; 1796 vp->v_fifoinfo = NULL; 1797 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1798 vp->v_irflag = 0; 1799 vp->v_iflag = 0; 1800 vp->v_vflag = 0; 1801 bo->bo_flag = 0; 1802 vn_free(vp); 1803 } 1804 1805 /* 1806 * Delete from old mount point vnode list, if on one. 1807 */ 1808 static void 1809 delmntque(struct vnode *vp) 1810 { 1811 struct mount *mp; 1812 1813 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 1814 1815 mp = vp->v_mount; 1816 if (mp == NULL) 1817 return; 1818 MNT_ILOCK(mp); 1819 VI_LOCK(vp); 1820 vp->v_mount = NULL; 1821 VI_UNLOCK(vp); 1822 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1823 ("bad mount point vnode list size")); 1824 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1825 mp->mnt_nvnodelistsize--; 1826 MNT_REL(mp); 1827 MNT_IUNLOCK(mp); 1828 } 1829 1830 static void 1831 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1832 { 1833 1834 vp->v_data = NULL; 1835 vp->v_op = &dead_vnodeops; 1836 vgone(vp); 1837 vput(vp); 1838 } 1839 1840 /* 1841 * Insert into list of vnodes for the new mount point, if available. 1842 */ 1843 int 1844 insmntque1(struct vnode *vp, struct mount *mp, 1845 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1846 { 1847 1848 KASSERT(vp->v_mount == NULL, 1849 ("insmntque: vnode already on per mount vnode list")); 1850 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1851 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1852 1853 /* 1854 * We acquire the vnode interlock early to ensure that the 1855 * vnode cannot be recycled by another process releasing a 1856 * holdcnt on it before we get it on both the vnode list 1857 * and the active vnode list. The mount mutex protects only 1858 * manipulation of the vnode list and the vnode freelist 1859 * mutex protects only manipulation of the active vnode list. 1860 * Hence the need to hold the vnode interlock throughout. 1861 */ 1862 MNT_ILOCK(mp); 1863 VI_LOCK(vp); 1864 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1865 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1866 mp->mnt_nvnodelistsize == 0)) && 1867 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1868 VI_UNLOCK(vp); 1869 MNT_IUNLOCK(mp); 1870 if (dtr != NULL) 1871 dtr(vp, dtr_arg); 1872 return (EBUSY); 1873 } 1874 vp->v_mount = mp; 1875 MNT_REF(mp); 1876 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1877 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1878 ("neg mount point vnode list size")); 1879 mp->mnt_nvnodelistsize++; 1880 VI_UNLOCK(vp); 1881 MNT_IUNLOCK(mp); 1882 return (0); 1883 } 1884 1885 int 1886 insmntque(struct vnode *vp, struct mount *mp) 1887 { 1888 1889 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1890 } 1891 1892 /* 1893 * Flush out and invalidate all buffers associated with a bufobj 1894 * Called with the underlying object locked. 1895 */ 1896 int 1897 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1898 { 1899 int error; 1900 1901 BO_LOCK(bo); 1902 if (flags & V_SAVE) { 1903 error = bufobj_wwait(bo, slpflag, slptimeo); 1904 if (error) { 1905 BO_UNLOCK(bo); 1906 return (error); 1907 } 1908 if (bo->bo_dirty.bv_cnt > 0) { 1909 BO_UNLOCK(bo); 1910 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1911 return (error); 1912 /* 1913 * XXX We could save a lock/unlock if this was only 1914 * enabled under INVARIANTS 1915 */ 1916 BO_LOCK(bo); 1917 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1918 panic("vinvalbuf: dirty bufs"); 1919 } 1920 } 1921 /* 1922 * If you alter this loop please notice that interlock is dropped and 1923 * reacquired in flushbuflist. Special care is needed to ensure that 1924 * no race conditions occur from this. 1925 */ 1926 do { 1927 error = flushbuflist(&bo->bo_clean, 1928 flags, bo, slpflag, slptimeo); 1929 if (error == 0 && !(flags & V_CLEANONLY)) 1930 error = flushbuflist(&bo->bo_dirty, 1931 flags, bo, slpflag, slptimeo); 1932 if (error != 0 && error != EAGAIN) { 1933 BO_UNLOCK(bo); 1934 return (error); 1935 } 1936 } while (error != 0); 1937 1938 /* 1939 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1940 * have write I/O in-progress but if there is a VM object then the 1941 * VM object can also have read-I/O in-progress. 1942 */ 1943 do { 1944 bufobj_wwait(bo, 0, 0); 1945 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1946 BO_UNLOCK(bo); 1947 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1948 BO_LOCK(bo); 1949 } 1950 } while (bo->bo_numoutput > 0); 1951 BO_UNLOCK(bo); 1952 1953 /* 1954 * Destroy the copy in the VM cache, too. 1955 */ 1956 if (bo->bo_object != NULL && 1957 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1958 VM_OBJECT_WLOCK(bo->bo_object); 1959 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1960 OBJPR_CLEANONLY : 0); 1961 VM_OBJECT_WUNLOCK(bo->bo_object); 1962 } 1963 1964 #ifdef INVARIANTS 1965 BO_LOCK(bo); 1966 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1967 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1968 bo->bo_clean.bv_cnt > 0)) 1969 panic("vinvalbuf: flush failed"); 1970 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1971 bo->bo_dirty.bv_cnt > 0) 1972 panic("vinvalbuf: flush dirty failed"); 1973 BO_UNLOCK(bo); 1974 #endif 1975 return (0); 1976 } 1977 1978 /* 1979 * Flush out and invalidate all buffers associated with a vnode. 1980 * Called with the underlying object locked. 1981 */ 1982 int 1983 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1984 { 1985 1986 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1987 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1988 if (vp->v_object != NULL && vp->v_object->handle != vp) 1989 return (0); 1990 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1991 } 1992 1993 /* 1994 * Flush out buffers on the specified list. 1995 * 1996 */ 1997 static int 1998 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1999 int slptimeo) 2000 { 2001 struct buf *bp, *nbp; 2002 int retval, error; 2003 daddr_t lblkno; 2004 b_xflags_t xflags; 2005 2006 ASSERT_BO_WLOCKED(bo); 2007 2008 retval = 0; 2009 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2010 /* 2011 * If we are flushing both V_NORMAL and V_ALT buffers then 2012 * do not skip any buffers. If we are flushing only V_NORMAL 2013 * buffers then skip buffers marked as BX_ALTDATA. If we are 2014 * flushing only V_ALT buffers then skip buffers not marked 2015 * as BX_ALTDATA. 2016 */ 2017 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2018 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2019 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2020 continue; 2021 } 2022 if (nbp != NULL) { 2023 lblkno = nbp->b_lblkno; 2024 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2025 } 2026 retval = EAGAIN; 2027 error = BUF_TIMELOCK(bp, 2028 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2029 "flushbuf", slpflag, slptimeo); 2030 if (error) { 2031 BO_LOCK(bo); 2032 return (error != ENOLCK ? error : EAGAIN); 2033 } 2034 KASSERT(bp->b_bufobj == bo, 2035 ("bp %p wrong b_bufobj %p should be %p", 2036 bp, bp->b_bufobj, bo)); 2037 /* 2038 * XXX Since there are no node locks for NFS, I 2039 * believe there is a slight chance that a delayed 2040 * write will occur while sleeping just above, so 2041 * check for it. 2042 */ 2043 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2044 (flags & V_SAVE)) { 2045 bremfree(bp); 2046 bp->b_flags |= B_ASYNC; 2047 bwrite(bp); 2048 BO_LOCK(bo); 2049 return (EAGAIN); /* XXX: why not loop ? */ 2050 } 2051 bremfree(bp); 2052 bp->b_flags |= (B_INVAL | B_RELBUF); 2053 bp->b_flags &= ~B_ASYNC; 2054 brelse(bp); 2055 BO_LOCK(bo); 2056 if (nbp == NULL) 2057 break; 2058 nbp = gbincore(bo, lblkno); 2059 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2060 != xflags) 2061 break; /* nbp invalid */ 2062 } 2063 return (retval); 2064 } 2065 2066 int 2067 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2068 { 2069 struct buf *bp; 2070 int error; 2071 daddr_t lblkno; 2072 2073 ASSERT_BO_LOCKED(bo); 2074 2075 for (lblkno = startn;;) { 2076 again: 2077 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2078 if (bp == NULL || bp->b_lblkno >= endn || 2079 bp->b_lblkno < startn) 2080 break; 2081 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2082 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2083 if (error != 0) { 2084 BO_RLOCK(bo); 2085 if (error == ENOLCK) 2086 goto again; 2087 return (error); 2088 } 2089 KASSERT(bp->b_bufobj == bo, 2090 ("bp %p wrong b_bufobj %p should be %p", 2091 bp, bp->b_bufobj, bo)); 2092 lblkno = bp->b_lblkno + 1; 2093 if ((bp->b_flags & B_MANAGED) == 0) 2094 bremfree(bp); 2095 bp->b_flags |= B_RELBUF; 2096 /* 2097 * In the VMIO case, use the B_NOREUSE flag to hint that the 2098 * pages backing each buffer in the range are unlikely to be 2099 * reused. Dirty buffers will have the hint applied once 2100 * they've been written. 2101 */ 2102 if ((bp->b_flags & B_VMIO) != 0) 2103 bp->b_flags |= B_NOREUSE; 2104 brelse(bp); 2105 BO_RLOCK(bo); 2106 } 2107 return (0); 2108 } 2109 2110 /* 2111 * Truncate a file's buffer and pages to a specified length. This 2112 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2113 * sync activity. 2114 */ 2115 int 2116 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2117 { 2118 struct buf *bp, *nbp; 2119 struct bufobj *bo; 2120 daddr_t startlbn; 2121 2122 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2123 vp, blksize, (uintmax_t)length); 2124 2125 /* 2126 * Round up to the *next* lbn. 2127 */ 2128 startlbn = howmany(length, blksize); 2129 2130 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2131 2132 bo = &vp->v_bufobj; 2133 restart_unlocked: 2134 BO_LOCK(bo); 2135 2136 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2137 ; 2138 2139 if (length > 0) { 2140 restartsync: 2141 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2142 if (bp->b_lblkno > 0) 2143 continue; 2144 /* 2145 * Since we hold the vnode lock this should only 2146 * fail if we're racing with the buf daemon. 2147 */ 2148 if (BUF_LOCK(bp, 2149 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2150 BO_LOCKPTR(bo)) == ENOLCK) 2151 goto restart_unlocked; 2152 2153 VNASSERT((bp->b_flags & B_DELWRI), vp, 2154 ("buf(%p) on dirty queue without DELWRI", bp)); 2155 2156 bremfree(bp); 2157 bawrite(bp); 2158 BO_LOCK(bo); 2159 goto restartsync; 2160 } 2161 } 2162 2163 bufobj_wwait(bo, 0, 0); 2164 BO_UNLOCK(bo); 2165 vnode_pager_setsize(vp, length); 2166 2167 return (0); 2168 } 2169 2170 /* 2171 * Invalidate the cached pages of a file's buffer within the range of block 2172 * numbers [startlbn, endlbn). 2173 */ 2174 void 2175 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2176 int blksize) 2177 { 2178 struct bufobj *bo; 2179 off_t start, end; 2180 2181 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2182 2183 start = blksize * startlbn; 2184 end = blksize * endlbn; 2185 2186 bo = &vp->v_bufobj; 2187 BO_LOCK(bo); 2188 MPASS(blksize == bo->bo_bsize); 2189 2190 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2191 ; 2192 2193 BO_UNLOCK(bo); 2194 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2195 } 2196 2197 static int 2198 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2199 daddr_t startlbn, daddr_t endlbn) 2200 { 2201 struct buf *bp, *nbp; 2202 bool anyfreed; 2203 2204 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2205 ASSERT_BO_LOCKED(bo); 2206 2207 do { 2208 anyfreed = false; 2209 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2210 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2211 continue; 2212 if (BUF_LOCK(bp, 2213 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2214 BO_LOCKPTR(bo)) == ENOLCK) { 2215 BO_LOCK(bo); 2216 return (EAGAIN); 2217 } 2218 2219 bremfree(bp); 2220 bp->b_flags |= B_INVAL | B_RELBUF; 2221 bp->b_flags &= ~B_ASYNC; 2222 brelse(bp); 2223 anyfreed = true; 2224 2225 BO_LOCK(bo); 2226 if (nbp != NULL && 2227 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2228 nbp->b_vp != vp || 2229 (nbp->b_flags & B_DELWRI) != 0)) 2230 return (EAGAIN); 2231 } 2232 2233 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2234 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2235 continue; 2236 if (BUF_LOCK(bp, 2237 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2238 BO_LOCKPTR(bo)) == ENOLCK) { 2239 BO_LOCK(bo); 2240 return (EAGAIN); 2241 } 2242 bremfree(bp); 2243 bp->b_flags |= B_INVAL | B_RELBUF; 2244 bp->b_flags &= ~B_ASYNC; 2245 brelse(bp); 2246 anyfreed = true; 2247 2248 BO_LOCK(bo); 2249 if (nbp != NULL && 2250 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2251 (nbp->b_vp != vp) || 2252 (nbp->b_flags & B_DELWRI) == 0)) 2253 return (EAGAIN); 2254 } 2255 } while (anyfreed); 2256 return (0); 2257 } 2258 2259 static void 2260 buf_vlist_remove(struct buf *bp) 2261 { 2262 struct bufv *bv; 2263 2264 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2265 ASSERT_BO_WLOCKED(bp->b_bufobj); 2266 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 2267 (BX_VNDIRTY|BX_VNCLEAN), 2268 ("buf_vlist_remove: Buf %p is on two lists", bp)); 2269 if (bp->b_xflags & BX_VNDIRTY) 2270 bv = &bp->b_bufobj->bo_dirty; 2271 else 2272 bv = &bp->b_bufobj->bo_clean; 2273 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2274 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2275 bv->bv_cnt--; 2276 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2277 } 2278 2279 /* 2280 * Add the buffer to the sorted clean or dirty block list. 2281 * 2282 * NOTE: xflags is passed as a constant, optimizing this inline function! 2283 */ 2284 static void 2285 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2286 { 2287 struct bufv *bv; 2288 struct buf *n; 2289 int error; 2290 2291 ASSERT_BO_WLOCKED(bo); 2292 KASSERT((bo->bo_flag & BO_NOBUFS) == 0, 2293 ("buf_vlist_add: bo %p does not allow bufs", bo)); 2294 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2295 ("dead bo %p", bo)); 2296 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2297 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2298 bp->b_xflags |= xflags; 2299 if (xflags & BX_VNDIRTY) 2300 bv = &bo->bo_dirty; 2301 else 2302 bv = &bo->bo_clean; 2303 2304 /* 2305 * Keep the list ordered. Optimize empty list insertion. Assume 2306 * we tend to grow at the tail so lookup_le should usually be cheaper 2307 * than _ge. 2308 */ 2309 if (bv->bv_cnt == 0 || 2310 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2311 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2312 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2313 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2314 else 2315 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2316 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2317 if (error) 2318 panic("buf_vlist_add: Preallocated nodes insufficient."); 2319 bv->bv_cnt++; 2320 } 2321 2322 /* 2323 * Look up a buffer using the buffer tries. 2324 */ 2325 struct buf * 2326 gbincore(struct bufobj *bo, daddr_t lblkno) 2327 { 2328 struct buf *bp; 2329 2330 ASSERT_BO_LOCKED(bo); 2331 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2332 if (bp != NULL) 2333 return (bp); 2334 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2335 } 2336 2337 /* 2338 * Associate a buffer with a vnode. 2339 */ 2340 void 2341 bgetvp(struct vnode *vp, struct buf *bp) 2342 { 2343 struct bufobj *bo; 2344 2345 bo = &vp->v_bufobj; 2346 ASSERT_BO_WLOCKED(bo); 2347 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2348 2349 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2350 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2351 ("bgetvp: bp already attached! %p", bp)); 2352 2353 vhold(vp); 2354 bp->b_vp = vp; 2355 bp->b_bufobj = bo; 2356 /* 2357 * Insert onto list for new vnode. 2358 */ 2359 buf_vlist_add(bp, bo, BX_VNCLEAN); 2360 } 2361 2362 /* 2363 * Disassociate a buffer from a vnode. 2364 */ 2365 void 2366 brelvp(struct buf *bp) 2367 { 2368 struct bufobj *bo; 2369 struct vnode *vp; 2370 2371 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2372 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2373 2374 /* 2375 * Delete from old vnode list, if on one. 2376 */ 2377 vp = bp->b_vp; /* XXX */ 2378 bo = bp->b_bufobj; 2379 BO_LOCK(bo); 2380 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2381 buf_vlist_remove(bp); 2382 else 2383 panic("brelvp: Buffer %p not on queue.", bp); 2384 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2385 bo->bo_flag &= ~BO_ONWORKLST; 2386 mtx_lock(&sync_mtx); 2387 LIST_REMOVE(bo, bo_synclist); 2388 syncer_worklist_len--; 2389 mtx_unlock(&sync_mtx); 2390 } 2391 bp->b_vp = NULL; 2392 bp->b_bufobj = NULL; 2393 BO_UNLOCK(bo); 2394 vdrop(vp); 2395 } 2396 2397 /* 2398 * Add an item to the syncer work queue. 2399 */ 2400 static void 2401 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2402 { 2403 int slot; 2404 2405 ASSERT_BO_WLOCKED(bo); 2406 2407 mtx_lock(&sync_mtx); 2408 if (bo->bo_flag & BO_ONWORKLST) 2409 LIST_REMOVE(bo, bo_synclist); 2410 else { 2411 bo->bo_flag |= BO_ONWORKLST; 2412 syncer_worklist_len++; 2413 } 2414 2415 if (delay > syncer_maxdelay - 2) 2416 delay = syncer_maxdelay - 2; 2417 slot = (syncer_delayno + delay) & syncer_mask; 2418 2419 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2420 mtx_unlock(&sync_mtx); 2421 } 2422 2423 static int 2424 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2425 { 2426 int error, len; 2427 2428 mtx_lock(&sync_mtx); 2429 len = syncer_worklist_len - sync_vnode_count; 2430 mtx_unlock(&sync_mtx); 2431 error = SYSCTL_OUT(req, &len, sizeof(len)); 2432 return (error); 2433 } 2434 2435 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2436 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2437 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2438 2439 static struct proc *updateproc; 2440 static void sched_sync(void); 2441 static struct kproc_desc up_kp = { 2442 "syncer", 2443 sched_sync, 2444 &updateproc 2445 }; 2446 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2447 2448 static int 2449 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2450 { 2451 struct vnode *vp; 2452 struct mount *mp; 2453 2454 *bo = LIST_FIRST(slp); 2455 if (*bo == NULL) 2456 return (0); 2457 vp = bo2vnode(*bo); 2458 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2459 return (1); 2460 /* 2461 * We use vhold in case the vnode does not 2462 * successfully sync. vhold prevents the vnode from 2463 * going away when we unlock the sync_mtx so that 2464 * we can acquire the vnode interlock. 2465 */ 2466 vholdl(vp); 2467 mtx_unlock(&sync_mtx); 2468 VI_UNLOCK(vp); 2469 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2470 vdrop(vp); 2471 mtx_lock(&sync_mtx); 2472 return (*bo == LIST_FIRST(slp)); 2473 } 2474 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2475 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2476 VOP_UNLOCK(vp); 2477 vn_finished_write(mp); 2478 BO_LOCK(*bo); 2479 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2480 /* 2481 * Put us back on the worklist. The worklist 2482 * routine will remove us from our current 2483 * position and then add us back in at a later 2484 * position. 2485 */ 2486 vn_syncer_add_to_worklist(*bo, syncdelay); 2487 } 2488 BO_UNLOCK(*bo); 2489 vdrop(vp); 2490 mtx_lock(&sync_mtx); 2491 return (0); 2492 } 2493 2494 static int first_printf = 1; 2495 2496 /* 2497 * System filesystem synchronizer daemon. 2498 */ 2499 static void 2500 sched_sync(void) 2501 { 2502 struct synclist *next, *slp; 2503 struct bufobj *bo; 2504 long starttime; 2505 struct thread *td = curthread; 2506 int last_work_seen; 2507 int net_worklist_len; 2508 int syncer_final_iter; 2509 int error; 2510 2511 last_work_seen = 0; 2512 syncer_final_iter = 0; 2513 syncer_state = SYNCER_RUNNING; 2514 starttime = time_uptime; 2515 td->td_pflags |= TDP_NORUNNINGBUF; 2516 2517 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2518 SHUTDOWN_PRI_LAST); 2519 2520 mtx_lock(&sync_mtx); 2521 for (;;) { 2522 if (syncer_state == SYNCER_FINAL_DELAY && 2523 syncer_final_iter == 0) { 2524 mtx_unlock(&sync_mtx); 2525 kproc_suspend_check(td->td_proc); 2526 mtx_lock(&sync_mtx); 2527 } 2528 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2529 if (syncer_state != SYNCER_RUNNING && 2530 starttime != time_uptime) { 2531 if (first_printf) { 2532 printf("\nSyncing disks, vnodes remaining... "); 2533 first_printf = 0; 2534 } 2535 printf("%d ", net_worklist_len); 2536 } 2537 starttime = time_uptime; 2538 2539 /* 2540 * Push files whose dirty time has expired. Be careful 2541 * of interrupt race on slp queue. 2542 * 2543 * Skip over empty worklist slots when shutting down. 2544 */ 2545 do { 2546 slp = &syncer_workitem_pending[syncer_delayno]; 2547 syncer_delayno += 1; 2548 if (syncer_delayno == syncer_maxdelay) 2549 syncer_delayno = 0; 2550 next = &syncer_workitem_pending[syncer_delayno]; 2551 /* 2552 * If the worklist has wrapped since the 2553 * it was emptied of all but syncer vnodes, 2554 * switch to the FINAL_DELAY state and run 2555 * for one more second. 2556 */ 2557 if (syncer_state == SYNCER_SHUTTING_DOWN && 2558 net_worklist_len == 0 && 2559 last_work_seen == syncer_delayno) { 2560 syncer_state = SYNCER_FINAL_DELAY; 2561 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2562 } 2563 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2564 syncer_worklist_len > 0); 2565 2566 /* 2567 * Keep track of the last time there was anything 2568 * on the worklist other than syncer vnodes. 2569 * Return to the SHUTTING_DOWN state if any 2570 * new work appears. 2571 */ 2572 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2573 last_work_seen = syncer_delayno; 2574 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2575 syncer_state = SYNCER_SHUTTING_DOWN; 2576 while (!LIST_EMPTY(slp)) { 2577 error = sync_vnode(slp, &bo, td); 2578 if (error == 1) { 2579 LIST_REMOVE(bo, bo_synclist); 2580 LIST_INSERT_HEAD(next, bo, bo_synclist); 2581 continue; 2582 } 2583 2584 if (first_printf == 0) { 2585 /* 2586 * Drop the sync mutex, because some watchdog 2587 * drivers need to sleep while patting 2588 */ 2589 mtx_unlock(&sync_mtx); 2590 wdog_kern_pat(WD_LASTVAL); 2591 mtx_lock(&sync_mtx); 2592 } 2593 2594 } 2595 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2596 syncer_final_iter--; 2597 /* 2598 * The variable rushjob allows the kernel to speed up the 2599 * processing of the filesystem syncer process. A rushjob 2600 * value of N tells the filesystem syncer to process the next 2601 * N seconds worth of work on its queue ASAP. Currently rushjob 2602 * is used by the soft update code to speed up the filesystem 2603 * syncer process when the incore state is getting so far 2604 * ahead of the disk that the kernel memory pool is being 2605 * threatened with exhaustion. 2606 */ 2607 if (rushjob > 0) { 2608 rushjob -= 1; 2609 continue; 2610 } 2611 /* 2612 * Just sleep for a short period of time between 2613 * iterations when shutting down to allow some I/O 2614 * to happen. 2615 * 2616 * If it has taken us less than a second to process the 2617 * current work, then wait. Otherwise start right over 2618 * again. We can still lose time if any single round 2619 * takes more than two seconds, but it does not really 2620 * matter as we are just trying to generally pace the 2621 * filesystem activity. 2622 */ 2623 if (syncer_state != SYNCER_RUNNING || 2624 time_uptime == starttime) { 2625 thread_lock(td); 2626 sched_prio(td, PPAUSE); 2627 thread_unlock(td); 2628 } 2629 if (syncer_state != SYNCER_RUNNING) 2630 cv_timedwait(&sync_wakeup, &sync_mtx, 2631 hz / SYNCER_SHUTDOWN_SPEEDUP); 2632 else if (time_uptime == starttime) 2633 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2634 } 2635 } 2636 2637 /* 2638 * Request the syncer daemon to speed up its work. 2639 * We never push it to speed up more than half of its 2640 * normal turn time, otherwise it could take over the cpu. 2641 */ 2642 int 2643 speedup_syncer(void) 2644 { 2645 int ret = 0; 2646 2647 mtx_lock(&sync_mtx); 2648 if (rushjob < syncdelay / 2) { 2649 rushjob += 1; 2650 stat_rush_requests += 1; 2651 ret = 1; 2652 } 2653 mtx_unlock(&sync_mtx); 2654 cv_broadcast(&sync_wakeup); 2655 return (ret); 2656 } 2657 2658 /* 2659 * Tell the syncer to speed up its work and run though its work 2660 * list several times, then tell it to shut down. 2661 */ 2662 static void 2663 syncer_shutdown(void *arg, int howto) 2664 { 2665 2666 if (howto & RB_NOSYNC) 2667 return; 2668 mtx_lock(&sync_mtx); 2669 syncer_state = SYNCER_SHUTTING_DOWN; 2670 rushjob = 0; 2671 mtx_unlock(&sync_mtx); 2672 cv_broadcast(&sync_wakeup); 2673 kproc_shutdown(arg, howto); 2674 } 2675 2676 void 2677 syncer_suspend(void) 2678 { 2679 2680 syncer_shutdown(updateproc, 0); 2681 } 2682 2683 void 2684 syncer_resume(void) 2685 { 2686 2687 mtx_lock(&sync_mtx); 2688 first_printf = 1; 2689 syncer_state = SYNCER_RUNNING; 2690 mtx_unlock(&sync_mtx); 2691 cv_broadcast(&sync_wakeup); 2692 kproc_resume(updateproc); 2693 } 2694 2695 /* 2696 * Reassign a buffer from one vnode to another. 2697 * Used to assign file specific control information 2698 * (indirect blocks) to the vnode to which they belong. 2699 */ 2700 void 2701 reassignbuf(struct buf *bp) 2702 { 2703 struct vnode *vp; 2704 struct bufobj *bo; 2705 int delay; 2706 #ifdef INVARIANTS 2707 struct bufv *bv; 2708 #endif 2709 2710 vp = bp->b_vp; 2711 bo = bp->b_bufobj; 2712 ++reassignbufcalls; 2713 2714 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2715 bp, bp->b_vp, bp->b_flags); 2716 /* 2717 * B_PAGING flagged buffers cannot be reassigned because their vp 2718 * is not fully linked in. 2719 */ 2720 if (bp->b_flags & B_PAGING) 2721 panic("cannot reassign paging buffer"); 2722 2723 /* 2724 * Delete from old vnode list, if on one. 2725 */ 2726 BO_LOCK(bo); 2727 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2728 buf_vlist_remove(bp); 2729 else 2730 panic("reassignbuf: Buffer %p not on queue.", bp); 2731 /* 2732 * If dirty, put on list of dirty buffers; otherwise insert onto list 2733 * of clean buffers. 2734 */ 2735 if (bp->b_flags & B_DELWRI) { 2736 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2737 switch (vp->v_type) { 2738 case VDIR: 2739 delay = dirdelay; 2740 break; 2741 case VCHR: 2742 delay = metadelay; 2743 break; 2744 default: 2745 delay = filedelay; 2746 } 2747 vn_syncer_add_to_worklist(bo, delay); 2748 } 2749 buf_vlist_add(bp, bo, BX_VNDIRTY); 2750 } else { 2751 buf_vlist_add(bp, bo, BX_VNCLEAN); 2752 2753 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2754 mtx_lock(&sync_mtx); 2755 LIST_REMOVE(bo, bo_synclist); 2756 syncer_worklist_len--; 2757 mtx_unlock(&sync_mtx); 2758 bo->bo_flag &= ~BO_ONWORKLST; 2759 } 2760 } 2761 #ifdef INVARIANTS 2762 bv = &bo->bo_clean; 2763 bp = TAILQ_FIRST(&bv->bv_hd); 2764 KASSERT(bp == NULL || bp->b_bufobj == bo, 2765 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2766 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2767 KASSERT(bp == NULL || bp->b_bufobj == bo, 2768 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2769 bv = &bo->bo_dirty; 2770 bp = TAILQ_FIRST(&bv->bv_hd); 2771 KASSERT(bp == NULL || bp->b_bufobj == bo, 2772 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2773 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2774 KASSERT(bp == NULL || bp->b_bufobj == bo, 2775 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2776 #endif 2777 BO_UNLOCK(bo); 2778 } 2779 2780 static void 2781 v_init_counters(struct vnode *vp) 2782 { 2783 2784 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2785 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2786 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2787 2788 refcount_init(&vp->v_holdcnt, 1); 2789 refcount_init(&vp->v_usecount, 1); 2790 } 2791 2792 /* 2793 * Increment si_usecount of the associated device, if any. 2794 */ 2795 static void 2796 v_incr_devcount(struct vnode *vp) 2797 { 2798 2799 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2800 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2801 dev_lock(); 2802 vp->v_rdev->si_usecount++; 2803 dev_unlock(); 2804 } 2805 } 2806 2807 /* 2808 * Decrement si_usecount of the associated device, if any. 2809 * 2810 * The caller is required to hold the interlock when transitioning a VCHR use 2811 * count to zero. This prevents a race with devfs_reclaim_vchr() that would 2812 * leak a si_usecount reference. The vnode lock will also prevent this race 2813 * if it is held while dropping the last ref. 2814 * 2815 * The race is: 2816 * 2817 * CPU1 CPU2 2818 * devfs_reclaim_vchr 2819 * make v_usecount == 0 2820 * VI_LOCK 2821 * sees v_usecount == 0, no updates 2822 * vp->v_rdev = NULL; 2823 * ... 2824 * VI_UNLOCK 2825 * VI_LOCK 2826 * v_decr_devcount 2827 * sees v_rdev == NULL, no updates 2828 * 2829 * In this scenario si_devcount decrement is not performed. 2830 */ 2831 static void 2832 v_decr_devcount(struct vnode *vp) 2833 { 2834 2835 ASSERT_VOP_LOCKED(vp, __func__); 2836 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2837 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2838 dev_lock(); 2839 VNPASS(vp->v_rdev->si_usecount > 0, vp); 2840 vp->v_rdev->si_usecount--; 2841 dev_unlock(); 2842 } 2843 } 2844 2845 /* 2846 * Grab a particular vnode from the free list, increment its 2847 * reference count and lock it. VIRF_DOOMED is set if the vnode 2848 * is being destroyed. Only callers who specify LK_RETRY will 2849 * see doomed vnodes. If inactive processing was delayed in 2850 * vput try to do it here. 2851 * 2852 * usecount is manipulated using atomics without holding any locks. 2853 * 2854 * holdcnt can be manipulated using atomics without holding any locks, 2855 * except when transitioning 1<->0, in which case the interlock is held. 2856 */ 2857 enum vgetstate 2858 vget_prep(struct vnode *vp) 2859 { 2860 enum vgetstate vs; 2861 2862 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2863 vs = VGET_USECOUNT; 2864 } else { 2865 vhold(vp); 2866 vs = VGET_HOLDCNT; 2867 } 2868 return (vs); 2869 } 2870 2871 int 2872 vget(struct vnode *vp, int flags, struct thread *td) 2873 { 2874 enum vgetstate vs; 2875 2876 MPASS(td == curthread); 2877 2878 vs = vget_prep(vp); 2879 return (vget_finish(vp, flags, vs)); 2880 } 2881 2882 static int __noinline 2883 vget_finish_vchr(struct vnode *vp) 2884 { 2885 2886 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2887 2888 /* 2889 * See the comment in vget_finish before usecount bump. 2890 */ 2891 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2892 #ifdef INVARIANTS 2893 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2894 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 2895 #else 2896 refcount_release(&vp->v_holdcnt); 2897 #endif 2898 return (0); 2899 } 2900 2901 VI_LOCK(vp); 2902 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2903 #ifdef INVARIANTS 2904 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2905 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2906 #else 2907 refcount_release(&vp->v_holdcnt); 2908 #endif 2909 VI_UNLOCK(vp); 2910 return (0); 2911 } 2912 v_incr_devcount(vp); 2913 refcount_acquire(&vp->v_usecount); 2914 VI_UNLOCK(vp); 2915 return (0); 2916 } 2917 2918 int 2919 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2920 { 2921 int error, old; 2922 2923 if ((flags & LK_INTERLOCK) != 0) 2924 ASSERT_VI_LOCKED(vp, __func__); 2925 else 2926 ASSERT_VI_UNLOCKED(vp, __func__); 2927 VNPASS(vp->v_holdcnt > 0, vp); 2928 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2929 2930 error = vn_lock(vp, flags); 2931 if (__predict_false(error != 0)) { 2932 if (vs == VGET_USECOUNT) 2933 vrele(vp); 2934 else 2935 vdrop(vp); 2936 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2937 vp); 2938 return (error); 2939 } 2940 2941 if (vs == VGET_USECOUNT) 2942 return (0); 2943 2944 if (__predict_false(vp->v_type == VCHR)) 2945 return (vget_finish_vchr(vp)); 2946 2947 /* 2948 * We hold the vnode. If the usecount is 0 it will be utilized to keep 2949 * the vnode around. Otherwise someone else lended their hold count and 2950 * we have to drop ours. 2951 */ 2952 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2953 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 2954 if (old != 0) { 2955 #ifdef INVARIANTS 2956 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2957 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2958 #else 2959 refcount_release(&vp->v_holdcnt); 2960 #endif 2961 } 2962 return (0); 2963 } 2964 2965 /* 2966 * Increase the reference (use) and hold count of a vnode. 2967 * This will also remove the vnode from the free list if it is presently free. 2968 */ 2969 static void __noinline 2970 vref_vchr(struct vnode *vp, bool interlock) 2971 { 2972 2973 /* 2974 * See the comment in vget_finish before usecount bump. 2975 */ 2976 if (!interlock) { 2977 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2978 VNODE_REFCOUNT_FENCE_ACQ(); 2979 VNASSERT(vp->v_holdcnt > 0, vp, 2980 ("%s: active vnode not held", __func__)); 2981 return; 2982 } 2983 VI_LOCK(vp); 2984 /* 2985 * By the time we get here the vnode might have been doomed, at 2986 * which point the 0->1 use count transition is no longer 2987 * protected by the interlock. Since it can't bounce back to 2988 * VCHR and requires vref semantics, punt it back 2989 */ 2990 if (__predict_false(vp->v_type == VBAD)) { 2991 VI_UNLOCK(vp); 2992 vref(vp); 2993 return; 2994 } 2995 } 2996 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2997 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2998 VNODE_REFCOUNT_FENCE_ACQ(); 2999 VNASSERT(vp->v_holdcnt > 0, vp, 3000 ("%s: active vnode not held", __func__)); 3001 if (!interlock) 3002 VI_UNLOCK(vp); 3003 return; 3004 } 3005 vhold(vp); 3006 v_incr_devcount(vp); 3007 refcount_acquire(&vp->v_usecount); 3008 if (!interlock) 3009 VI_UNLOCK(vp); 3010 return; 3011 } 3012 3013 void 3014 vref(struct vnode *vp) 3015 { 3016 int old; 3017 3018 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3019 if (__predict_false(vp->v_type == VCHR)) { 3020 vref_vchr(vp, false); 3021 return; 3022 } 3023 3024 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3025 VNODE_REFCOUNT_FENCE_ACQ(); 3026 VNASSERT(vp->v_holdcnt > 0, vp, 3027 ("%s: active vnode not held", __func__)); 3028 return; 3029 } 3030 vhold(vp); 3031 /* 3032 * See the comment in vget_finish. 3033 */ 3034 old = atomic_fetchadd_int(&vp->v_usecount, 1); 3035 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 3036 if (old != 0) { 3037 #ifdef INVARIANTS 3038 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 3039 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 3040 #else 3041 refcount_release(&vp->v_holdcnt); 3042 #endif 3043 } 3044 } 3045 3046 void 3047 vrefl(struct vnode *vp) 3048 { 3049 3050 ASSERT_VI_LOCKED(vp, __func__); 3051 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3052 if (__predict_false(vp->v_type == VCHR)) { 3053 vref_vchr(vp, true); 3054 return; 3055 } 3056 vref(vp); 3057 } 3058 3059 void 3060 vrefact(struct vnode *vp) 3061 { 3062 3063 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3064 #ifdef INVARIANTS 3065 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 3066 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3067 #else 3068 refcount_acquire(&vp->v_usecount); 3069 #endif 3070 } 3071 3072 void 3073 vrefactn(struct vnode *vp, u_int n) 3074 { 3075 3076 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3077 #ifdef INVARIANTS 3078 int old = atomic_fetchadd_int(&vp->v_usecount, n); 3079 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3080 #else 3081 atomic_add_int(&vp->v_usecount, n); 3082 #endif 3083 } 3084 3085 /* 3086 * Return reference count of a vnode. 3087 * 3088 * The results of this call are only guaranteed when some mechanism is used to 3089 * stop other processes from gaining references to the vnode. This may be the 3090 * case if the caller holds the only reference. This is also useful when stale 3091 * data is acceptable as race conditions may be accounted for by some other 3092 * means. 3093 */ 3094 int 3095 vrefcnt(struct vnode *vp) 3096 { 3097 3098 return (vp->v_usecount); 3099 } 3100 3101 void 3102 vlazy(struct vnode *vp) 3103 { 3104 struct mount *mp; 3105 3106 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 3107 3108 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 3109 return; 3110 /* 3111 * We may get here for inactive routines after the vnode got doomed. 3112 */ 3113 if (VN_IS_DOOMED(vp)) 3114 return; 3115 mp = vp->v_mount; 3116 mtx_lock(&mp->mnt_listmtx); 3117 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 3118 vp->v_mflag |= VMP_LAZYLIST; 3119 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3120 mp->mnt_lazyvnodelistsize++; 3121 } 3122 mtx_unlock(&mp->mnt_listmtx); 3123 } 3124 3125 /* 3126 * This routine is only meant to be called from vgonel prior to dooming 3127 * the vnode. 3128 */ 3129 static void 3130 vunlazy_gone(struct vnode *vp) 3131 { 3132 struct mount *mp; 3133 3134 ASSERT_VOP_ELOCKED(vp, __func__); 3135 ASSERT_VI_LOCKED(vp, __func__); 3136 VNPASS(!VN_IS_DOOMED(vp), vp); 3137 3138 if (vp->v_mflag & VMP_LAZYLIST) { 3139 mp = vp->v_mount; 3140 mtx_lock(&mp->mnt_listmtx); 3141 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3142 vp->v_mflag &= ~VMP_LAZYLIST; 3143 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3144 mp->mnt_lazyvnodelistsize--; 3145 mtx_unlock(&mp->mnt_listmtx); 3146 } 3147 } 3148 3149 static void 3150 vdefer_inactive(struct vnode *vp) 3151 { 3152 3153 ASSERT_VI_LOCKED(vp, __func__); 3154 VNASSERT(vp->v_holdcnt > 0, vp, 3155 ("%s: vnode without hold count", __func__)); 3156 if (VN_IS_DOOMED(vp)) { 3157 vdropl(vp); 3158 return; 3159 } 3160 if (vp->v_iflag & VI_DEFINACT) { 3161 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3162 vdropl(vp); 3163 return; 3164 } 3165 if (vp->v_usecount > 0) { 3166 vp->v_iflag &= ~VI_OWEINACT; 3167 vdropl(vp); 3168 return; 3169 } 3170 vlazy(vp); 3171 vp->v_iflag |= VI_DEFINACT; 3172 VI_UNLOCK(vp); 3173 counter_u64_add(deferred_inact, 1); 3174 } 3175 3176 static void 3177 vdefer_inactive_unlocked(struct vnode *vp) 3178 { 3179 3180 VI_LOCK(vp); 3181 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3182 vdropl(vp); 3183 return; 3184 } 3185 vdefer_inactive(vp); 3186 } 3187 3188 enum vput_op { VRELE, VPUT, VUNREF }; 3189 3190 /* 3191 * Handle ->v_usecount transitioning to 0. 3192 * 3193 * By releasing the last usecount we take ownership of the hold count which 3194 * provides liveness of the vnode, meaning we have to vdrop. 3195 * 3196 * If the vnode is of type VCHR we may need to decrement si_usecount, see 3197 * v_decr_devcount for details. 3198 * 3199 * For all vnodes we may need to perform inactive processing. It requires an 3200 * exclusive lock on the vnode, while it is legal to call here with only a 3201 * shared lock (or no locks). If locking the vnode in an expected manner fails, 3202 * inactive processing gets deferred to the syncer. 3203 * 3204 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3205 * on the lock being held all the way until VOP_INACTIVE. This in particular 3206 * happens with UFS which adds half-constructed vnodes to the hash, where they 3207 * can be found by other code. 3208 */ 3209 static void 3210 vput_final(struct vnode *vp, enum vput_op func) 3211 { 3212 int error; 3213 bool want_unlock; 3214 3215 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3216 VNPASS(vp->v_holdcnt > 0, vp); 3217 3218 VI_LOCK(vp); 3219 if (__predict_false(vp->v_type == VCHR && func != VRELE)) 3220 v_decr_devcount(vp); 3221 3222 /* 3223 * By the time we got here someone else might have transitioned 3224 * the count back to > 0. 3225 */ 3226 if (vp->v_usecount > 0) 3227 goto out; 3228 3229 /* 3230 * If the vnode is doomed vgone already performed inactive processing 3231 * (if needed). 3232 */ 3233 if (VN_IS_DOOMED(vp)) 3234 goto out; 3235 3236 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0)) 3237 goto out; 3238 3239 if (vp->v_iflag & VI_DOINGINACT) 3240 goto out; 3241 3242 /* 3243 * Locking operations here will drop the interlock and possibly the 3244 * vnode lock, opening a window where the vnode can get doomed all the 3245 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to 3246 * perform inactive. 3247 */ 3248 vp->v_iflag |= VI_OWEINACT; 3249 want_unlock = false; 3250 error = 0; 3251 switch (func) { 3252 case VRELE: 3253 switch (VOP_ISLOCKED(vp)) { 3254 case LK_EXCLUSIVE: 3255 break; 3256 case LK_EXCLOTHER: 3257 case 0: 3258 want_unlock = true; 3259 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3260 VI_LOCK(vp); 3261 break; 3262 default: 3263 /* 3264 * The lock has at least one sharer, but we have no way 3265 * to conclude whether this is us. Play it safe and 3266 * defer processing. 3267 */ 3268 error = EAGAIN; 3269 break; 3270 } 3271 break; 3272 case VPUT: 3273 want_unlock = true; 3274 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3275 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3276 LK_NOWAIT); 3277 VI_LOCK(vp); 3278 } 3279 break; 3280 case VUNREF: 3281 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3282 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3283 VI_LOCK(vp); 3284 } 3285 break; 3286 } 3287 if (error == 0) { 3288 vinactive(vp); 3289 if (want_unlock) 3290 VOP_UNLOCK(vp); 3291 vdropl(vp); 3292 } else { 3293 vdefer_inactive(vp); 3294 } 3295 return; 3296 out: 3297 if (func == VPUT) 3298 VOP_UNLOCK(vp); 3299 vdropl(vp); 3300 } 3301 3302 /* 3303 * Decrement ->v_usecount for a vnode. 3304 * 3305 * Releasing the last use count requires additional processing, see vput_final 3306 * above for details. 3307 * 3308 * Note that releasing use count without the vnode lock requires special casing 3309 * for VCHR, see v_decr_devcount for details. 3310 * 3311 * Comment above each variant denotes lock state on entry and exit. 3312 */ 3313 3314 static void __noinline 3315 vrele_vchr(struct vnode *vp) 3316 { 3317 3318 if (refcount_release_if_not_last(&vp->v_usecount)) 3319 return; 3320 VI_LOCK(vp); 3321 if (!refcount_release(&vp->v_usecount)) { 3322 VI_UNLOCK(vp); 3323 return; 3324 } 3325 v_decr_devcount(vp); 3326 VI_UNLOCK(vp); 3327 vput_final(vp, VRELE); 3328 } 3329 3330 /* 3331 * in: any 3332 * out: same as passed in 3333 */ 3334 void 3335 vrele(struct vnode *vp) 3336 { 3337 3338 ASSERT_VI_UNLOCKED(vp, __func__); 3339 if (__predict_false(vp->v_type == VCHR)) { 3340 vrele_vchr(vp); 3341 return; 3342 } 3343 if (!refcount_release(&vp->v_usecount)) 3344 return; 3345 vput_final(vp, VRELE); 3346 } 3347 3348 /* 3349 * in: locked 3350 * out: unlocked 3351 */ 3352 void 3353 vput(struct vnode *vp) 3354 { 3355 3356 ASSERT_VOP_LOCKED(vp, __func__); 3357 ASSERT_VI_UNLOCKED(vp, __func__); 3358 if (!refcount_release(&vp->v_usecount)) { 3359 VOP_UNLOCK(vp); 3360 return; 3361 } 3362 vput_final(vp, VPUT); 3363 } 3364 3365 /* 3366 * in: locked 3367 * out: locked 3368 */ 3369 void 3370 vunref(struct vnode *vp) 3371 { 3372 3373 ASSERT_VOP_LOCKED(vp, __func__); 3374 ASSERT_VI_UNLOCKED(vp, __func__); 3375 if (!refcount_release(&vp->v_usecount)) 3376 return; 3377 vput_final(vp, VUNREF); 3378 } 3379 3380 void 3381 vhold(struct vnode *vp) 3382 { 3383 struct vdbatch *vd; 3384 int old; 3385 3386 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3387 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3388 VNASSERT(old >= 0, vp, ("%s: wrong hold count %d", __func__, old)); 3389 if (old != 0) 3390 return; 3391 critical_enter(); 3392 vd = DPCPU_PTR(vd); 3393 vd->freevnodes--; 3394 critical_exit(); 3395 } 3396 3397 void 3398 vholdl(struct vnode *vp) 3399 { 3400 3401 ASSERT_VI_LOCKED(vp, __func__); 3402 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3403 vhold(vp); 3404 } 3405 3406 void 3407 vholdnz(struct vnode *vp) 3408 { 3409 3410 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3411 #ifdef INVARIANTS 3412 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3413 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 3414 #else 3415 atomic_add_int(&vp->v_holdcnt, 1); 3416 #endif 3417 } 3418 3419 static void __noinline 3420 vdbatch_process(struct vdbatch *vd) 3421 { 3422 struct vnode *vp; 3423 int i; 3424 3425 mtx_assert(&vd->lock, MA_OWNED); 3426 MPASS(curthread->td_pinned > 0); 3427 MPASS(vd->index == VDBATCH_SIZE); 3428 3429 mtx_lock(&vnode_list_mtx); 3430 critical_enter(); 3431 freevnodes += vd->freevnodes; 3432 for (i = 0; i < VDBATCH_SIZE; i++) { 3433 vp = vd->tab[i]; 3434 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3435 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3436 MPASS(vp->v_dbatchcpu != NOCPU); 3437 vp->v_dbatchcpu = NOCPU; 3438 } 3439 mtx_unlock(&vnode_list_mtx); 3440 vd->freevnodes = 0; 3441 bzero(vd->tab, sizeof(vd->tab)); 3442 vd->index = 0; 3443 critical_exit(); 3444 } 3445 3446 static void 3447 vdbatch_enqueue(struct vnode *vp) 3448 { 3449 struct vdbatch *vd; 3450 3451 ASSERT_VI_LOCKED(vp, __func__); 3452 VNASSERT(!VN_IS_DOOMED(vp), vp, 3453 ("%s: deferring requeue of a doomed vnode", __func__)); 3454 3455 critical_enter(); 3456 vd = DPCPU_PTR(vd); 3457 vd->freevnodes++; 3458 if (vp->v_dbatchcpu != NOCPU) { 3459 VI_UNLOCK(vp); 3460 critical_exit(); 3461 return; 3462 } 3463 3464 sched_pin(); 3465 critical_exit(); 3466 mtx_lock(&vd->lock); 3467 MPASS(vd->index < VDBATCH_SIZE); 3468 MPASS(vd->tab[vd->index] == NULL); 3469 /* 3470 * A hack: we depend on being pinned so that we know what to put in 3471 * ->v_dbatchcpu. 3472 */ 3473 vp->v_dbatchcpu = curcpu; 3474 vd->tab[vd->index] = vp; 3475 vd->index++; 3476 VI_UNLOCK(vp); 3477 if (vd->index == VDBATCH_SIZE) 3478 vdbatch_process(vd); 3479 mtx_unlock(&vd->lock); 3480 sched_unpin(); 3481 } 3482 3483 /* 3484 * This routine must only be called for vnodes which are about to be 3485 * deallocated. Supporting dequeue for arbitrary vndoes would require 3486 * validating that the locked batch matches. 3487 */ 3488 static void 3489 vdbatch_dequeue(struct vnode *vp) 3490 { 3491 struct vdbatch *vd; 3492 int i; 3493 short cpu; 3494 3495 VNASSERT(vp->v_type == VBAD || vp->v_type == VNON, vp, 3496 ("%s: called for a used vnode\n", __func__)); 3497 3498 cpu = vp->v_dbatchcpu; 3499 if (cpu == NOCPU) 3500 return; 3501 3502 vd = DPCPU_ID_PTR(cpu, vd); 3503 mtx_lock(&vd->lock); 3504 for (i = 0; i < vd->index; i++) { 3505 if (vd->tab[i] != vp) 3506 continue; 3507 vp->v_dbatchcpu = NOCPU; 3508 vd->index--; 3509 vd->tab[i] = vd->tab[vd->index]; 3510 vd->tab[vd->index] = NULL; 3511 break; 3512 } 3513 mtx_unlock(&vd->lock); 3514 /* 3515 * Either we dequeued the vnode above or the target CPU beat us to it. 3516 */ 3517 MPASS(vp->v_dbatchcpu == NOCPU); 3518 } 3519 3520 /* 3521 * Drop the hold count of the vnode. If this is the last reference to 3522 * the vnode we place it on the free list unless it has been vgone'd 3523 * (marked VIRF_DOOMED) in which case we will free it. 3524 * 3525 * Because the vnode vm object keeps a hold reference on the vnode if 3526 * there is at least one resident non-cached page, the vnode cannot 3527 * leave the active list without the page cleanup done. 3528 */ 3529 static void 3530 vdrop_deactivate(struct vnode *vp) 3531 { 3532 struct mount *mp; 3533 3534 ASSERT_VI_LOCKED(vp, __func__); 3535 /* 3536 * Mark a vnode as free: remove it from its active list 3537 * and put it up for recycling on the freelist. 3538 */ 3539 VNASSERT(!VN_IS_DOOMED(vp), vp, 3540 ("vdrop: returning doomed vnode")); 3541 VNASSERT(vp->v_op != NULL, vp, 3542 ("vdrop: vnode already reclaimed.")); 3543 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 3544 ("vnode with VI_OWEINACT set")); 3545 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, 3546 ("vnode with VI_DEFINACT set")); 3547 if (vp->v_mflag & VMP_LAZYLIST) { 3548 mp = vp->v_mount; 3549 mtx_lock(&mp->mnt_listmtx); 3550 VNASSERT(vp->v_mflag & VMP_LAZYLIST, vp, ("lost VMP_LAZYLIST")); 3551 /* 3552 * Don't remove the vnode from the lazy list if another thread 3553 * has increased the hold count. It may have re-enqueued the 3554 * vnode to the lazy list and is now responsible for its 3555 * removal. 3556 */ 3557 if (vp->v_holdcnt == 0) { 3558 vp->v_mflag &= ~VMP_LAZYLIST; 3559 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3560 mp->mnt_lazyvnodelistsize--; 3561 } 3562 mtx_unlock(&mp->mnt_listmtx); 3563 } 3564 vdbatch_enqueue(vp); 3565 } 3566 3567 void 3568 vdrop(struct vnode *vp) 3569 { 3570 3571 ASSERT_VI_UNLOCKED(vp, __func__); 3572 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3573 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3574 return; 3575 VI_LOCK(vp); 3576 vdropl(vp); 3577 } 3578 3579 void 3580 vdropl(struct vnode *vp) 3581 { 3582 3583 ASSERT_VI_LOCKED(vp, __func__); 3584 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3585 if (!refcount_release(&vp->v_holdcnt)) { 3586 VI_UNLOCK(vp); 3587 return; 3588 } 3589 if (VN_IS_DOOMED(vp)) { 3590 freevnode(vp); 3591 return; 3592 } 3593 vdrop_deactivate(vp); 3594 } 3595 3596 /* 3597 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3598 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3599 */ 3600 static void 3601 vinactivef(struct vnode *vp) 3602 { 3603 struct vm_object *obj; 3604 3605 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3606 ASSERT_VI_LOCKED(vp, "vinactive"); 3607 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3608 ("vinactive: recursed on VI_DOINGINACT")); 3609 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3610 vp->v_iflag |= VI_DOINGINACT; 3611 vp->v_iflag &= ~VI_OWEINACT; 3612 VI_UNLOCK(vp); 3613 /* 3614 * Before moving off the active list, we must be sure that any 3615 * modified pages are converted into the vnode's dirty 3616 * buffers, since these will no longer be checked once the 3617 * vnode is on the inactive list. 3618 * 3619 * The write-out of the dirty pages is asynchronous. At the 3620 * point that VOP_INACTIVE() is called, there could still be 3621 * pending I/O and dirty pages in the object. 3622 */ 3623 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3624 vm_object_mightbedirty(obj)) { 3625 VM_OBJECT_WLOCK(obj); 3626 vm_object_page_clean(obj, 0, 0, 0); 3627 VM_OBJECT_WUNLOCK(obj); 3628 } 3629 VOP_INACTIVE(vp, curthread); 3630 VI_LOCK(vp); 3631 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3632 ("vinactive: lost VI_DOINGINACT")); 3633 vp->v_iflag &= ~VI_DOINGINACT; 3634 } 3635 3636 void 3637 vinactive(struct vnode *vp) 3638 { 3639 3640 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3641 ASSERT_VI_LOCKED(vp, "vinactive"); 3642 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3643 3644 if ((vp->v_iflag & VI_OWEINACT) == 0) 3645 return; 3646 if (vp->v_iflag & VI_DOINGINACT) 3647 return; 3648 if (vp->v_usecount > 0) { 3649 vp->v_iflag &= ~VI_OWEINACT; 3650 return; 3651 } 3652 vinactivef(vp); 3653 } 3654 3655 /* 3656 * Remove any vnodes in the vnode table belonging to mount point mp. 3657 * 3658 * If FORCECLOSE is not specified, there should not be any active ones, 3659 * return error if any are found (nb: this is a user error, not a 3660 * system error). If FORCECLOSE is specified, detach any active vnodes 3661 * that are found. 3662 * 3663 * If WRITECLOSE is set, only flush out regular file vnodes open for 3664 * writing. 3665 * 3666 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3667 * 3668 * `rootrefs' specifies the base reference count for the root vnode 3669 * of this filesystem. The root vnode is considered busy if its 3670 * v_usecount exceeds this value. On a successful return, vflush(, td) 3671 * will call vrele() on the root vnode exactly rootrefs times. 3672 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3673 * be zero. 3674 */ 3675 #ifdef DIAGNOSTIC 3676 static int busyprt = 0; /* print out busy vnodes */ 3677 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3678 #endif 3679 3680 int 3681 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3682 { 3683 struct vnode *vp, *mvp, *rootvp = NULL; 3684 struct vattr vattr; 3685 int busy = 0, error; 3686 3687 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3688 rootrefs, flags); 3689 if (rootrefs > 0) { 3690 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3691 ("vflush: bad args")); 3692 /* 3693 * Get the filesystem root vnode. We can vput() it 3694 * immediately, since with rootrefs > 0, it won't go away. 3695 */ 3696 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3697 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3698 __func__, error); 3699 return (error); 3700 } 3701 vput(rootvp); 3702 } 3703 loop: 3704 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3705 vholdl(vp); 3706 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3707 if (error) { 3708 vdrop(vp); 3709 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3710 goto loop; 3711 } 3712 /* 3713 * Skip over a vnodes marked VV_SYSTEM. 3714 */ 3715 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3716 VOP_UNLOCK(vp); 3717 vdrop(vp); 3718 continue; 3719 } 3720 /* 3721 * If WRITECLOSE is set, flush out unlinked but still open 3722 * files (even if open only for reading) and regular file 3723 * vnodes open for writing. 3724 */ 3725 if (flags & WRITECLOSE) { 3726 if (vp->v_object != NULL) { 3727 VM_OBJECT_WLOCK(vp->v_object); 3728 vm_object_page_clean(vp->v_object, 0, 0, 0); 3729 VM_OBJECT_WUNLOCK(vp->v_object); 3730 } 3731 error = VOP_FSYNC(vp, MNT_WAIT, td); 3732 if (error != 0) { 3733 VOP_UNLOCK(vp); 3734 vdrop(vp); 3735 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3736 return (error); 3737 } 3738 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3739 VI_LOCK(vp); 3740 3741 if ((vp->v_type == VNON || 3742 (error == 0 && vattr.va_nlink > 0)) && 3743 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3744 VOP_UNLOCK(vp); 3745 vdropl(vp); 3746 continue; 3747 } 3748 } else 3749 VI_LOCK(vp); 3750 /* 3751 * With v_usecount == 0, all we need to do is clear out the 3752 * vnode data structures and we are done. 3753 * 3754 * If FORCECLOSE is set, forcibly close the vnode. 3755 */ 3756 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3757 vgonel(vp); 3758 } else { 3759 busy++; 3760 #ifdef DIAGNOSTIC 3761 if (busyprt) 3762 vn_printf(vp, "vflush: busy vnode "); 3763 #endif 3764 } 3765 VOP_UNLOCK(vp); 3766 vdropl(vp); 3767 } 3768 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3769 /* 3770 * If just the root vnode is busy, and if its refcount 3771 * is equal to `rootrefs', then go ahead and kill it. 3772 */ 3773 VI_LOCK(rootvp); 3774 KASSERT(busy > 0, ("vflush: not busy")); 3775 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3776 ("vflush: usecount %d < rootrefs %d", 3777 rootvp->v_usecount, rootrefs)); 3778 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3779 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3780 vgone(rootvp); 3781 VOP_UNLOCK(rootvp); 3782 busy = 0; 3783 } else 3784 VI_UNLOCK(rootvp); 3785 } 3786 if (busy) { 3787 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3788 busy); 3789 return (EBUSY); 3790 } 3791 for (; rootrefs > 0; rootrefs--) 3792 vrele(rootvp); 3793 return (0); 3794 } 3795 3796 /* 3797 * Recycle an unused vnode to the front of the free list. 3798 */ 3799 int 3800 vrecycle(struct vnode *vp) 3801 { 3802 int recycled; 3803 3804 VI_LOCK(vp); 3805 recycled = vrecyclel(vp); 3806 VI_UNLOCK(vp); 3807 return (recycled); 3808 } 3809 3810 /* 3811 * vrecycle, with the vp interlock held. 3812 */ 3813 int 3814 vrecyclel(struct vnode *vp) 3815 { 3816 int recycled; 3817 3818 ASSERT_VOP_ELOCKED(vp, __func__); 3819 ASSERT_VI_LOCKED(vp, __func__); 3820 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3821 recycled = 0; 3822 if (vp->v_usecount == 0) { 3823 recycled = 1; 3824 vgonel(vp); 3825 } 3826 return (recycled); 3827 } 3828 3829 /* 3830 * Eliminate all activity associated with a vnode 3831 * in preparation for reuse. 3832 */ 3833 void 3834 vgone(struct vnode *vp) 3835 { 3836 VI_LOCK(vp); 3837 vgonel(vp); 3838 VI_UNLOCK(vp); 3839 } 3840 3841 static void 3842 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3843 struct vnode *lowervp __unused) 3844 { 3845 } 3846 3847 /* 3848 * Notify upper mounts about reclaimed or unlinked vnode. 3849 */ 3850 void 3851 vfs_notify_upper(struct vnode *vp, int event) 3852 { 3853 static struct vfsops vgonel_vfsops = { 3854 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3855 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3856 }; 3857 struct mount *mp, *ump, *mmp; 3858 3859 mp = vp->v_mount; 3860 if (mp == NULL) 3861 return; 3862 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3863 return; 3864 3865 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3866 mmp->mnt_op = &vgonel_vfsops; 3867 mmp->mnt_kern_flag |= MNTK_MARKER; 3868 MNT_ILOCK(mp); 3869 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3870 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3871 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3872 ump = TAILQ_NEXT(ump, mnt_upper_link); 3873 continue; 3874 } 3875 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3876 MNT_IUNLOCK(mp); 3877 switch (event) { 3878 case VFS_NOTIFY_UPPER_RECLAIM: 3879 VFS_RECLAIM_LOWERVP(ump, vp); 3880 break; 3881 case VFS_NOTIFY_UPPER_UNLINK: 3882 VFS_UNLINK_LOWERVP(ump, vp); 3883 break; 3884 default: 3885 KASSERT(0, ("invalid event %d", event)); 3886 break; 3887 } 3888 MNT_ILOCK(mp); 3889 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3890 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3891 } 3892 free(mmp, M_TEMP); 3893 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3894 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3895 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3896 wakeup(&mp->mnt_uppers); 3897 } 3898 MNT_IUNLOCK(mp); 3899 } 3900 3901 /* 3902 * vgone, with the vp interlock held. 3903 */ 3904 static void 3905 vgonel(struct vnode *vp) 3906 { 3907 struct thread *td; 3908 struct mount *mp; 3909 vm_object_t object; 3910 bool active, oweinact; 3911 3912 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3913 ASSERT_VI_LOCKED(vp, "vgonel"); 3914 VNASSERT(vp->v_holdcnt, vp, 3915 ("vgonel: vp %p has no reference.", vp)); 3916 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3917 td = curthread; 3918 3919 /* 3920 * Don't vgonel if we're already doomed. 3921 */ 3922 if (vp->v_irflag & VIRF_DOOMED) 3923 return; 3924 vunlazy_gone(vp); 3925 vp->v_irflag |= VIRF_DOOMED; 3926 3927 /* 3928 * Check to see if the vnode is in use. If so, we have to call 3929 * VOP_CLOSE() and VOP_INACTIVE(). 3930 */ 3931 active = vp->v_usecount > 0; 3932 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 3933 /* 3934 * If we need to do inactive VI_OWEINACT will be set. 3935 */ 3936 if (vp->v_iflag & VI_DEFINACT) { 3937 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3938 vp->v_iflag &= ~VI_DEFINACT; 3939 vdropl(vp); 3940 } else { 3941 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 3942 VI_UNLOCK(vp); 3943 } 3944 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3945 3946 /* 3947 * If purging an active vnode, it must be closed and 3948 * deactivated before being reclaimed. 3949 */ 3950 if (active) 3951 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3952 if (oweinact || active) { 3953 VI_LOCK(vp); 3954 vinactivef(vp); 3955 VI_UNLOCK(vp); 3956 } 3957 if (vp->v_type == VSOCK) 3958 vfs_unp_reclaim(vp); 3959 3960 /* 3961 * Clean out any buffers associated with the vnode. 3962 * If the flush fails, just toss the buffers. 3963 */ 3964 mp = NULL; 3965 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3966 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3967 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3968 while (vinvalbuf(vp, 0, 0, 0) != 0) 3969 ; 3970 } 3971 3972 BO_LOCK(&vp->v_bufobj); 3973 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3974 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3975 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3976 vp->v_bufobj.bo_clean.bv_cnt == 0, 3977 ("vp %p bufobj not invalidated", vp)); 3978 3979 /* 3980 * For VMIO bufobj, BO_DEAD is set later, or in 3981 * vm_object_terminate() after the object's page queue is 3982 * flushed. 3983 */ 3984 object = vp->v_bufobj.bo_object; 3985 if (object == NULL) 3986 vp->v_bufobj.bo_flag |= BO_DEAD; 3987 BO_UNLOCK(&vp->v_bufobj); 3988 3989 /* 3990 * Handle the VM part. Tmpfs handles v_object on its own (the 3991 * OBJT_VNODE check). Nullfs or other bypassing filesystems 3992 * should not touch the object borrowed from the lower vnode 3993 * (the handle check). 3994 */ 3995 if (object != NULL && object->type == OBJT_VNODE && 3996 object->handle == vp) 3997 vnode_destroy_vobject(vp); 3998 3999 /* 4000 * Reclaim the vnode. 4001 */ 4002 if (VOP_RECLAIM(vp, td)) 4003 panic("vgone: cannot reclaim"); 4004 if (mp != NULL) 4005 vn_finished_secondary_write(mp); 4006 VNASSERT(vp->v_object == NULL, vp, 4007 ("vop_reclaim left v_object vp=%p", vp)); 4008 /* 4009 * Clear the advisory locks and wake up waiting threads. 4010 */ 4011 (void)VOP_ADVLOCKPURGE(vp); 4012 vp->v_lockf = NULL; 4013 /* 4014 * Delete from old mount point vnode list. 4015 */ 4016 delmntque(vp); 4017 cache_purge(vp); 4018 /* 4019 * Done with purge, reset to the standard lock and invalidate 4020 * the vnode. 4021 */ 4022 VI_LOCK(vp); 4023 vp->v_vnlock = &vp->v_lock; 4024 vp->v_op = &dead_vnodeops; 4025 vp->v_type = VBAD; 4026 } 4027 4028 /* 4029 * Calculate the total number of references to a special device. 4030 */ 4031 int 4032 vcount(struct vnode *vp) 4033 { 4034 int count; 4035 4036 dev_lock(); 4037 count = vp->v_rdev->si_usecount; 4038 dev_unlock(); 4039 return (count); 4040 } 4041 4042 /* 4043 * Print out a description of a vnode. 4044 */ 4045 static const char * const typename[] = 4046 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 4047 "VMARKER"}; 4048 4049 void 4050 vn_printf(struct vnode *vp, const char *fmt, ...) 4051 { 4052 va_list ap; 4053 char buf[256], buf2[16]; 4054 u_long flags; 4055 4056 va_start(ap, fmt); 4057 vprintf(fmt, ap); 4058 va_end(ap); 4059 printf("%p: ", (void *)vp); 4060 printf("type %s\n", typename[vp->v_type]); 4061 printf(" usecount %d, writecount %d, refcount %d", 4062 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 4063 switch (vp->v_type) { 4064 case VDIR: 4065 printf(" mountedhere %p\n", vp->v_mountedhere); 4066 break; 4067 case VCHR: 4068 printf(" rdev %p\n", vp->v_rdev); 4069 break; 4070 case VSOCK: 4071 printf(" socket %p\n", vp->v_unpcb); 4072 break; 4073 case VFIFO: 4074 printf(" fifoinfo %p\n", vp->v_fifoinfo); 4075 break; 4076 default: 4077 printf("\n"); 4078 break; 4079 } 4080 buf[0] = '\0'; 4081 buf[1] = '\0'; 4082 if (vp->v_irflag & VIRF_DOOMED) 4083 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 4084 flags = vp->v_irflag & ~(VIRF_DOOMED); 4085 if (flags != 0) { 4086 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 4087 strlcat(buf, buf2, sizeof(buf)); 4088 } 4089 if (vp->v_vflag & VV_ROOT) 4090 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4091 if (vp->v_vflag & VV_ISTTY) 4092 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4093 if (vp->v_vflag & VV_NOSYNC) 4094 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4095 if (vp->v_vflag & VV_ETERNALDEV) 4096 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4097 if (vp->v_vflag & VV_CACHEDLABEL) 4098 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4099 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4100 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4101 if (vp->v_vflag & VV_COPYONWRITE) 4102 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4103 if (vp->v_vflag & VV_SYSTEM) 4104 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4105 if (vp->v_vflag & VV_PROCDEP) 4106 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4107 if (vp->v_vflag & VV_NOKNOTE) 4108 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 4109 if (vp->v_vflag & VV_DELETED) 4110 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4111 if (vp->v_vflag & VV_MD) 4112 strlcat(buf, "|VV_MD", sizeof(buf)); 4113 if (vp->v_vflag & VV_FORCEINSMQ) 4114 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4115 if (vp->v_vflag & VV_READLINK) 4116 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4117 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4118 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 4119 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 4120 if (flags != 0) { 4121 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4122 strlcat(buf, buf2, sizeof(buf)); 4123 } 4124 if (vp->v_iflag & VI_TEXT_REF) 4125 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 4126 if (vp->v_iflag & VI_MOUNT) 4127 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4128 if (vp->v_iflag & VI_DOINGINACT) 4129 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4130 if (vp->v_iflag & VI_OWEINACT) 4131 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4132 if (vp->v_iflag & VI_DEFINACT) 4133 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4134 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | 4135 VI_OWEINACT | VI_DEFINACT); 4136 if (flags != 0) { 4137 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4138 strlcat(buf, buf2, sizeof(buf)); 4139 } 4140 if (vp->v_mflag & VMP_LAZYLIST) 4141 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4142 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4143 if (flags != 0) { 4144 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4145 strlcat(buf, buf2, sizeof(buf)); 4146 } 4147 printf(" flags (%s)\n", buf + 1); 4148 if (mtx_owned(VI_MTX(vp))) 4149 printf(" VI_LOCKed"); 4150 if (vp->v_object != NULL) 4151 printf(" v_object %p ref %d pages %d " 4152 "cleanbuf %d dirtybuf %d\n", 4153 vp->v_object, vp->v_object->ref_count, 4154 vp->v_object->resident_page_count, 4155 vp->v_bufobj.bo_clean.bv_cnt, 4156 vp->v_bufobj.bo_dirty.bv_cnt); 4157 printf(" "); 4158 lockmgr_printinfo(vp->v_vnlock); 4159 if (vp->v_data != NULL) 4160 VOP_PRINT(vp); 4161 } 4162 4163 #ifdef DDB 4164 /* 4165 * List all of the locked vnodes in the system. 4166 * Called when debugging the kernel. 4167 */ 4168 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 4169 { 4170 struct mount *mp; 4171 struct vnode *vp; 4172 4173 /* 4174 * Note: because this is DDB, we can't obey the locking semantics 4175 * for these structures, which means we could catch an inconsistent 4176 * state and dereference a nasty pointer. Not much to be done 4177 * about that. 4178 */ 4179 db_printf("Locked vnodes\n"); 4180 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4181 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4182 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4183 vn_printf(vp, "vnode "); 4184 } 4185 } 4186 } 4187 4188 /* 4189 * Show details about the given vnode. 4190 */ 4191 DB_SHOW_COMMAND(vnode, db_show_vnode) 4192 { 4193 struct vnode *vp; 4194 4195 if (!have_addr) 4196 return; 4197 vp = (struct vnode *)addr; 4198 vn_printf(vp, "vnode "); 4199 } 4200 4201 /* 4202 * Show details about the given mount point. 4203 */ 4204 DB_SHOW_COMMAND(mount, db_show_mount) 4205 { 4206 struct mount *mp; 4207 struct vfsopt *opt; 4208 struct statfs *sp; 4209 struct vnode *vp; 4210 char buf[512]; 4211 uint64_t mflags; 4212 u_int flags; 4213 4214 if (!have_addr) { 4215 /* No address given, print short info about all mount points. */ 4216 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4217 db_printf("%p %s on %s (%s)\n", mp, 4218 mp->mnt_stat.f_mntfromname, 4219 mp->mnt_stat.f_mntonname, 4220 mp->mnt_stat.f_fstypename); 4221 if (db_pager_quit) 4222 break; 4223 } 4224 db_printf("\nMore info: show mount <addr>\n"); 4225 return; 4226 } 4227 4228 mp = (struct mount *)addr; 4229 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4230 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4231 4232 buf[0] = '\0'; 4233 mflags = mp->mnt_flag; 4234 #define MNT_FLAG(flag) do { \ 4235 if (mflags & (flag)) { \ 4236 if (buf[0] != '\0') \ 4237 strlcat(buf, ", ", sizeof(buf)); \ 4238 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4239 mflags &= ~(flag); \ 4240 } \ 4241 } while (0) 4242 MNT_FLAG(MNT_RDONLY); 4243 MNT_FLAG(MNT_SYNCHRONOUS); 4244 MNT_FLAG(MNT_NOEXEC); 4245 MNT_FLAG(MNT_NOSUID); 4246 MNT_FLAG(MNT_NFS4ACLS); 4247 MNT_FLAG(MNT_UNION); 4248 MNT_FLAG(MNT_ASYNC); 4249 MNT_FLAG(MNT_SUIDDIR); 4250 MNT_FLAG(MNT_SOFTDEP); 4251 MNT_FLAG(MNT_NOSYMFOLLOW); 4252 MNT_FLAG(MNT_GJOURNAL); 4253 MNT_FLAG(MNT_MULTILABEL); 4254 MNT_FLAG(MNT_ACLS); 4255 MNT_FLAG(MNT_NOATIME); 4256 MNT_FLAG(MNT_NOCLUSTERR); 4257 MNT_FLAG(MNT_NOCLUSTERW); 4258 MNT_FLAG(MNT_SUJ); 4259 MNT_FLAG(MNT_EXRDONLY); 4260 MNT_FLAG(MNT_EXPORTED); 4261 MNT_FLAG(MNT_DEFEXPORTED); 4262 MNT_FLAG(MNT_EXPORTANON); 4263 MNT_FLAG(MNT_EXKERB); 4264 MNT_FLAG(MNT_EXPUBLIC); 4265 MNT_FLAG(MNT_LOCAL); 4266 MNT_FLAG(MNT_QUOTA); 4267 MNT_FLAG(MNT_ROOTFS); 4268 MNT_FLAG(MNT_USER); 4269 MNT_FLAG(MNT_IGNORE); 4270 MNT_FLAG(MNT_UPDATE); 4271 MNT_FLAG(MNT_DELEXPORT); 4272 MNT_FLAG(MNT_RELOAD); 4273 MNT_FLAG(MNT_FORCE); 4274 MNT_FLAG(MNT_SNAPSHOT); 4275 MNT_FLAG(MNT_BYFSID); 4276 #undef MNT_FLAG 4277 if (mflags != 0) { 4278 if (buf[0] != '\0') 4279 strlcat(buf, ", ", sizeof(buf)); 4280 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4281 "0x%016jx", mflags); 4282 } 4283 db_printf(" mnt_flag = %s\n", buf); 4284 4285 buf[0] = '\0'; 4286 flags = mp->mnt_kern_flag; 4287 #define MNT_KERN_FLAG(flag) do { \ 4288 if (flags & (flag)) { \ 4289 if (buf[0] != '\0') \ 4290 strlcat(buf, ", ", sizeof(buf)); \ 4291 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4292 flags &= ~(flag); \ 4293 } \ 4294 } while (0) 4295 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4296 MNT_KERN_FLAG(MNTK_ASYNC); 4297 MNT_KERN_FLAG(MNTK_SOFTDEP); 4298 MNT_KERN_FLAG(MNTK_DRAINING); 4299 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4300 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4301 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4302 MNT_KERN_FLAG(MNTK_NO_IOPF); 4303 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 4304 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 4305 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 4306 MNT_KERN_FLAG(MNTK_MARKER); 4307 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4308 MNT_KERN_FLAG(MNTK_NOASYNC); 4309 MNT_KERN_FLAG(MNTK_UNMOUNT); 4310 MNT_KERN_FLAG(MNTK_MWAIT); 4311 MNT_KERN_FLAG(MNTK_SUSPEND); 4312 MNT_KERN_FLAG(MNTK_SUSPEND2); 4313 MNT_KERN_FLAG(MNTK_SUSPENDED); 4314 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4315 MNT_KERN_FLAG(MNTK_NOKNOTE); 4316 #undef MNT_KERN_FLAG 4317 if (flags != 0) { 4318 if (buf[0] != '\0') 4319 strlcat(buf, ", ", sizeof(buf)); 4320 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4321 "0x%08x", flags); 4322 } 4323 db_printf(" mnt_kern_flag = %s\n", buf); 4324 4325 db_printf(" mnt_opt = "); 4326 opt = TAILQ_FIRST(mp->mnt_opt); 4327 if (opt != NULL) { 4328 db_printf("%s", opt->name); 4329 opt = TAILQ_NEXT(opt, link); 4330 while (opt != NULL) { 4331 db_printf(", %s", opt->name); 4332 opt = TAILQ_NEXT(opt, link); 4333 } 4334 } 4335 db_printf("\n"); 4336 4337 sp = &mp->mnt_stat; 4338 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4339 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4340 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4341 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4342 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4343 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4344 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4345 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4346 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4347 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4348 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4349 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4350 4351 db_printf(" mnt_cred = { uid=%u ruid=%u", 4352 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4353 if (jailed(mp->mnt_cred)) 4354 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4355 db_printf(" }\n"); 4356 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4357 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4358 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4359 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4360 db_printf(" mnt_lazyvnodelistsize = %d\n", 4361 mp->mnt_lazyvnodelistsize); 4362 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4363 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4364 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4365 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4366 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4367 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4368 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4369 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4370 db_printf(" mnt_secondary_accwrites = %d\n", 4371 mp->mnt_secondary_accwrites); 4372 db_printf(" mnt_gjprovider = %s\n", 4373 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4374 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4375 4376 db_printf("\n\nList of active vnodes\n"); 4377 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4378 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4379 vn_printf(vp, "vnode "); 4380 if (db_pager_quit) 4381 break; 4382 } 4383 } 4384 db_printf("\n\nList of inactive vnodes\n"); 4385 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4386 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4387 vn_printf(vp, "vnode "); 4388 if (db_pager_quit) 4389 break; 4390 } 4391 } 4392 } 4393 #endif /* DDB */ 4394 4395 /* 4396 * Fill in a struct xvfsconf based on a struct vfsconf. 4397 */ 4398 static int 4399 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4400 { 4401 struct xvfsconf xvfsp; 4402 4403 bzero(&xvfsp, sizeof(xvfsp)); 4404 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4405 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4406 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4407 xvfsp.vfc_flags = vfsp->vfc_flags; 4408 /* 4409 * These are unused in userland, we keep them 4410 * to not break binary compatibility. 4411 */ 4412 xvfsp.vfc_vfsops = NULL; 4413 xvfsp.vfc_next = NULL; 4414 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4415 } 4416 4417 #ifdef COMPAT_FREEBSD32 4418 struct xvfsconf32 { 4419 uint32_t vfc_vfsops; 4420 char vfc_name[MFSNAMELEN]; 4421 int32_t vfc_typenum; 4422 int32_t vfc_refcount; 4423 int32_t vfc_flags; 4424 uint32_t vfc_next; 4425 }; 4426 4427 static int 4428 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4429 { 4430 struct xvfsconf32 xvfsp; 4431 4432 bzero(&xvfsp, sizeof(xvfsp)); 4433 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4434 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4435 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4436 xvfsp.vfc_flags = vfsp->vfc_flags; 4437 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4438 } 4439 #endif 4440 4441 /* 4442 * Top level filesystem related information gathering. 4443 */ 4444 static int 4445 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4446 { 4447 struct vfsconf *vfsp; 4448 int error; 4449 4450 error = 0; 4451 vfsconf_slock(); 4452 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4453 #ifdef COMPAT_FREEBSD32 4454 if (req->flags & SCTL_MASK32) 4455 error = vfsconf2x32(req, vfsp); 4456 else 4457 #endif 4458 error = vfsconf2x(req, vfsp); 4459 if (error) 4460 break; 4461 } 4462 vfsconf_sunlock(); 4463 return (error); 4464 } 4465 4466 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4467 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4468 "S,xvfsconf", "List of all configured filesystems"); 4469 4470 #ifndef BURN_BRIDGES 4471 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4472 4473 static int 4474 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4475 { 4476 int *name = (int *)arg1 - 1; /* XXX */ 4477 u_int namelen = arg2 + 1; /* XXX */ 4478 struct vfsconf *vfsp; 4479 4480 log(LOG_WARNING, "userland calling deprecated sysctl, " 4481 "please rebuild world\n"); 4482 4483 #if 1 || defined(COMPAT_PRELITE2) 4484 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4485 if (namelen == 1) 4486 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4487 #endif 4488 4489 switch (name[1]) { 4490 case VFS_MAXTYPENUM: 4491 if (namelen != 2) 4492 return (ENOTDIR); 4493 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4494 case VFS_CONF: 4495 if (namelen != 3) 4496 return (ENOTDIR); /* overloaded */ 4497 vfsconf_slock(); 4498 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4499 if (vfsp->vfc_typenum == name[2]) 4500 break; 4501 } 4502 vfsconf_sunlock(); 4503 if (vfsp == NULL) 4504 return (EOPNOTSUPP); 4505 #ifdef COMPAT_FREEBSD32 4506 if (req->flags & SCTL_MASK32) 4507 return (vfsconf2x32(req, vfsp)); 4508 else 4509 #endif 4510 return (vfsconf2x(req, vfsp)); 4511 } 4512 return (EOPNOTSUPP); 4513 } 4514 4515 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4516 CTLFLAG_MPSAFE, vfs_sysctl, 4517 "Generic filesystem"); 4518 4519 #if 1 || defined(COMPAT_PRELITE2) 4520 4521 static int 4522 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4523 { 4524 int error; 4525 struct vfsconf *vfsp; 4526 struct ovfsconf ovfs; 4527 4528 vfsconf_slock(); 4529 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4530 bzero(&ovfs, sizeof(ovfs)); 4531 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4532 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4533 ovfs.vfc_index = vfsp->vfc_typenum; 4534 ovfs.vfc_refcount = vfsp->vfc_refcount; 4535 ovfs.vfc_flags = vfsp->vfc_flags; 4536 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4537 if (error != 0) { 4538 vfsconf_sunlock(); 4539 return (error); 4540 } 4541 } 4542 vfsconf_sunlock(); 4543 return (0); 4544 } 4545 4546 #endif /* 1 || COMPAT_PRELITE2 */ 4547 #endif /* !BURN_BRIDGES */ 4548 4549 #define KINFO_VNODESLOP 10 4550 #ifdef notyet 4551 /* 4552 * Dump vnode list (via sysctl). 4553 */ 4554 /* ARGSUSED */ 4555 static int 4556 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4557 { 4558 struct xvnode *xvn; 4559 struct mount *mp; 4560 struct vnode *vp; 4561 int error, len, n; 4562 4563 /* 4564 * Stale numvnodes access is not fatal here. 4565 */ 4566 req->lock = 0; 4567 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4568 if (!req->oldptr) 4569 /* Make an estimate */ 4570 return (SYSCTL_OUT(req, 0, len)); 4571 4572 error = sysctl_wire_old_buffer(req, 0); 4573 if (error != 0) 4574 return (error); 4575 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4576 n = 0; 4577 mtx_lock(&mountlist_mtx); 4578 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4579 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4580 continue; 4581 MNT_ILOCK(mp); 4582 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4583 if (n == len) 4584 break; 4585 vref(vp); 4586 xvn[n].xv_size = sizeof *xvn; 4587 xvn[n].xv_vnode = vp; 4588 xvn[n].xv_id = 0; /* XXX compat */ 4589 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4590 XV_COPY(usecount); 4591 XV_COPY(writecount); 4592 XV_COPY(holdcnt); 4593 XV_COPY(mount); 4594 XV_COPY(numoutput); 4595 XV_COPY(type); 4596 #undef XV_COPY 4597 xvn[n].xv_flag = vp->v_vflag; 4598 4599 switch (vp->v_type) { 4600 case VREG: 4601 case VDIR: 4602 case VLNK: 4603 break; 4604 case VBLK: 4605 case VCHR: 4606 if (vp->v_rdev == NULL) { 4607 vrele(vp); 4608 continue; 4609 } 4610 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4611 break; 4612 case VSOCK: 4613 xvn[n].xv_socket = vp->v_socket; 4614 break; 4615 case VFIFO: 4616 xvn[n].xv_fifo = vp->v_fifoinfo; 4617 break; 4618 case VNON: 4619 case VBAD: 4620 default: 4621 /* shouldn't happen? */ 4622 vrele(vp); 4623 continue; 4624 } 4625 vrele(vp); 4626 ++n; 4627 } 4628 MNT_IUNLOCK(mp); 4629 mtx_lock(&mountlist_mtx); 4630 vfs_unbusy(mp); 4631 if (n == len) 4632 break; 4633 } 4634 mtx_unlock(&mountlist_mtx); 4635 4636 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4637 free(xvn, M_TEMP); 4638 return (error); 4639 } 4640 4641 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4642 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4643 ""); 4644 #endif 4645 4646 static void 4647 unmount_or_warn(struct mount *mp) 4648 { 4649 int error; 4650 4651 error = dounmount(mp, MNT_FORCE, curthread); 4652 if (error != 0) { 4653 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4654 if (error == EBUSY) 4655 printf("BUSY)\n"); 4656 else 4657 printf("%d)\n", error); 4658 } 4659 } 4660 4661 /* 4662 * Unmount all filesystems. The list is traversed in reverse order 4663 * of mounting to avoid dependencies. 4664 */ 4665 void 4666 vfs_unmountall(void) 4667 { 4668 struct mount *mp, *tmp; 4669 4670 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4671 4672 /* 4673 * Since this only runs when rebooting, it is not interlocked. 4674 */ 4675 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4676 vfs_ref(mp); 4677 4678 /* 4679 * Forcibly unmounting "/dev" before "/" would prevent clean 4680 * unmount of the latter. 4681 */ 4682 if (mp == rootdevmp) 4683 continue; 4684 4685 unmount_or_warn(mp); 4686 } 4687 4688 if (rootdevmp != NULL) 4689 unmount_or_warn(rootdevmp); 4690 } 4691 4692 static void 4693 vfs_deferred_inactive(struct vnode *vp, int lkflags) 4694 { 4695 4696 ASSERT_VI_LOCKED(vp, __func__); 4697 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, ("VI_DEFINACT still set")); 4698 if ((vp->v_iflag & VI_OWEINACT) == 0) { 4699 vdropl(vp); 4700 return; 4701 } 4702 if (vn_lock(vp, lkflags) == 0) { 4703 VI_LOCK(vp); 4704 vinactive(vp); 4705 VOP_UNLOCK(vp); 4706 vdropl(vp); 4707 return; 4708 } 4709 vdefer_inactive_unlocked(vp); 4710 } 4711 4712 static int 4713 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 4714 { 4715 4716 return (vp->v_iflag & VI_DEFINACT); 4717 } 4718 4719 static void __noinline 4720 vfs_periodic_inactive(struct mount *mp, int flags) 4721 { 4722 struct vnode *vp, *mvp; 4723 int lkflags; 4724 4725 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4726 if (flags != MNT_WAIT) 4727 lkflags |= LK_NOWAIT; 4728 4729 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 4730 if ((vp->v_iflag & VI_DEFINACT) == 0) { 4731 VI_UNLOCK(vp); 4732 continue; 4733 } 4734 vp->v_iflag &= ~VI_DEFINACT; 4735 vfs_deferred_inactive(vp, lkflags); 4736 } 4737 } 4738 4739 static inline bool 4740 vfs_want_msync(struct vnode *vp) 4741 { 4742 struct vm_object *obj; 4743 4744 /* 4745 * This test may be performed without any locks held. 4746 * We rely on vm_object's type stability. 4747 */ 4748 if (vp->v_vflag & VV_NOSYNC) 4749 return (false); 4750 obj = vp->v_object; 4751 return (obj != NULL && vm_object_mightbedirty(obj)); 4752 } 4753 4754 static int 4755 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 4756 { 4757 4758 if (vp->v_vflag & VV_NOSYNC) 4759 return (false); 4760 if (vp->v_iflag & VI_DEFINACT) 4761 return (true); 4762 return (vfs_want_msync(vp)); 4763 } 4764 4765 static void __noinline 4766 vfs_periodic_msync_inactive(struct mount *mp, int flags) 4767 { 4768 struct vnode *vp, *mvp; 4769 struct vm_object *obj; 4770 struct thread *td; 4771 int lkflags, objflags; 4772 bool seen_defer; 4773 4774 td = curthread; 4775 4776 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4777 if (flags != MNT_WAIT) { 4778 lkflags |= LK_NOWAIT; 4779 objflags = OBJPC_NOSYNC; 4780 } else { 4781 objflags = OBJPC_SYNC; 4782 } 4783 4784 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 4785 seen_defer = false; 4786 if (vp->v_iflag & VI_DEFINACT) { 4787 vp->v_iflag &= ~VI_DEFINACT; 4788 seen_defer = true; 4789 } 4790 if (!vfs_want_msync(vp)) { 4791 if (seen_defer) 4792 vfs_deferred_inactive(vp, lkflags); 4793 else 4794 VI_UNLOCK(vp); 4795 continue; 4796 } 4797 if (vget(vp, lkflags, td) == 0) { 4798 obj = vp->v_object; 4799 if (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0) { 4800 VM_OBJECT_WLOCK(obj); 4801 vm_object_page_clean(obj, 0, 0, objflags); 4802 VM_OBJECT_WUNLOCK(obj); 4803 } 4804 vput(vp); 4805 if (seen_defer) 4806 vdrop(vp); 4807 } else { 4808 if (seen_defer) 4809 vdefer_inactive_unlocked(vp); 4810 } 4811 } 4812 } 4813 4814 void 4815 vfs_periodic(struct mount *mp, int flags) 4816 { 4817 4818 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4819 4820 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4821 vfs_periodic_inactive(mp, flags); 4822 else 4823 vfs_periodic_msync_inactive(mp, flags); 4824 } 4825 4826 static void 4827 destroy_vpollinfo_free(struct vpollinfo *vi) 4828 { 4829 4830 knlist_destroy(&vi->vpi_selinfo.si_note); 4831 mtx_destroy(&vi->vpi_lock); 4832 uma_zfree(vnodepoll_zone, vi); 4833 } 4834 4835 static void 4836 destroy_vpollinfo(struct vpollinfo *vi) 4837 { 4838 4839 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4840 seldrain(&vi->vpi_selinfo); 4841 destroy_vpollinfo_free(vi); 4842 } 4843 4844 /* 4845 * Initialize per-vnode helper structure to hold poll-related state. 4846 */ 4847 void 4848 v_addpollinfo(struct vnode *vp) 4849 { 4850 struct vpollinfo *vi; 4851 4852 if (vp->v_pollinfo != NULL) 4853 return; 4854 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4855 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4856 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4857 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4858 VI_LOCK(vp); 4859 if (vp->v_pollinfo != NULL) { 4860 VI_UNLOCK(vp); 4861 destroy_vpollinfo_free(vi); 4862 return; 4863 } 4864 vp->v_pollinfo = vi; 4865 VI_UNLOCK(vp); 4866 } 4867 4868 /* 4869 * Record a process's interest in events which might happen to 4870 * a vnode. Because poll uses the historic select-style interface 4871 * internally, this routine serves as both the ``check for any 4872 * pending events'' and the ``record my interest in future events'' 4873 * functions. (These are done together, while the lock is held, 4874 * to avoid race conditions.) 4875 */ 4876 int 4877 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4878 { 4879 4880 v_addpollinfo(vp); 4881 mtx_lock(&vp->v_pollinfo->vpi_lock); 4882 if (vp->v_pollinfo->vpi_revents & events) { 4883 /* 4884 * This leaves events we are not interested 4885 * in available for the other process which 4886 * which presumably had requested them 4887 * (otherwise they would never have been 4888 * recorded). 4889 */ 4890 events &= vp->v_pollinfo->vpi_revents; 4891 vp->v_pollinfo->vpi_revents &= ~events; 4892 4893 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4894 return (events); 4895 } 4896 vp->v_pollinfo->vpi_events |= events; 4897 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4898 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4899 return (0); 4900 } 4901 4902 /* 4903 * Routine to create and manage a filesystem syncer vnode. 4904 */ 4905 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4906 static int sync_fsync(struct vop_fsync_args *); 4907 static int sync_inactive(struct vop_inactive_args *); 4908 static int sync_reclaim(struct vop_reclaim_args *); 4909 4910 static struct vop_vector sync_vnodeops = { 4911 .vop_bypass = VOP_EOPNOTSUPP, 4912 .vop_close = sync_close, /* close */ 4913 .vop_fsync = sync_fsync, /* fsync */ 4914 .vop_inactive = sync_inactive, /* inactive */ 4915 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 4916 .vop_reclaim = sync_reclaim, /* reclaim */ 4917 .vop_lock1 = vop_stdlock, /* lock */ 4918 .vop_unlock = vop_stdunlock, /* unlock */ 4919 .vop_islocked = vop_stdislocked, /* islocked */ 4920 }; 4921 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 4922 4923 /* 4924 * Create a new filesystem syncer vnode for the specified mount point. 4925 */ 4926 void 4927 vfs_allocate_syncvnode(struct mount *mp) 4928 { 4929 struct vnode *vp; 4930 struct bufobj *bo; 4931 static long start, incr, next; 4932 int error; 4933 4934 /* Allocate a new vnode */ 4935 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4936 if (error != 0) 4937 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4938 vp->v_type = VNON; 4939 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4940 vp->v_vflag |= VV_FORCEINSMQ; 4941 error = insmntque(vp, mp); 4942 if (error != 0) 4943 panic("vfs_allocate_syncvnode: insmntque() failed"); 4944 vp->v_vflag &= ~VV_FORCEINSMQ; 4945 VOP_UNLOCK(vp); 4946 /* 4947 * Place the vnode onto the syncer worklist. We attempt to 4948 * scatter them about on the list so that they will go off 4949 * at evenly distributed times even if all the filesystems 4950 * are mounted at once. 4951 */ 4952 next += incr; 4953 if (next == 0 || next > syncer_maxdelay) { 4954 start /= 2; 4955 incr /= 2; 4956 if (start == 0) { 4957 start = syncer_maxdelay / 2; 4958 incr = syncer_maxdelay; 4959 } 4960 next = start; 4961 } 4962 bo = &vp->v_bufobj; 4963 BO_LOCK(bo); 4964 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4965 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4966 mtx_lock(&sync_mtx); 4967 sync_vnode_count++; 4968 if (mp->mnt_syncer == NULL) { 4969 mp->mnt_syncer = vp; 4970 vp = NULL; 4971 } 4972 mtx_unlock(&sync_mtx); 4973 BO_UNLOCK(bo); 4974 if (vp != NULL) { 4975 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4976 vgone(vp); 4977 vput(vp); 4978 } 4979 } 4980 4981 void 4982 vfs_deallocate_syncvnode(struct mount *mp) 4983 { 4984 struct vnode *vp; 4985 4986 mtx_lock(&sync_mtx); 4987 vp = mp->mnt_syncer; 4988 if (vp != NULL) 4989 mp->mnt_syncer = NULL; 4990 mtx_unlock(&sync_mtx); 4991 if (vp != NULL) 4992 vrele(vp); 4993 } 4994 4995 /* 4996 * Do a lazy sync of the filesystem. 4997 */ 4998 static int 4999 sync_fsync(struct vop_fsync_args *ap) 5000 { 5001 struct vnode *syncvp = ap->a_vp; 5002 struct mount *mp = syncvp->v_mount; 5003 int error, save; 5004 struct bufobj *bo; 5005 5006 /* 5007 * We only need to do something if this is a lazy evaluation. 5008 */ 5009 if (ap->a_waitfor != MNT_LAZY) 5010 return (0); 5011 5012 /* 5013 * Move ourselves to the back of the sync list. 5014 */ 5015 bo = &syncvp->v_bufobj; 5016 BO_LOCK(bo); 5017 vn_syncer_add_to_worklist(bo, syncdelay); 5018 BO_UNLOCK(bo); 5019 5020 /* 5021 * Walk the list of vnodes pushing all that are dirty and 5022 * not already on the sync list. 5023 */ 5024 if (vfs_busy(mp, MBF_NOWAIT) != 0) 5025 return (0); 5026 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 5027 vfs_unbusy(mp); 5028 return (0); 5029 } 5030 save = curthread_pflags_set(TDP_SYNCIO); 5031 /* 5032 * The filesystem at hand may be idle with free vnodes stored in the 5033 * batch. Return them instead of letting them stay there indefinitely. 5034 */ 5035 vfs_periodic(mp, MNT_NOWAIT); 5036 error = VFS_SYNC(mp, MNT_LAZY); 5037 curthread_pflags_restore(save); 5038 vn_finished_write(mp); 5039 vfs_unbusy(mp); 5040 return (error); 5041 } 5042 5043 /* 5044 * The syncer vnode is no referenced. 5045 */ 5046 static int 5047 sync_inactive(struct vop_inactive_args *ap) 5048 { 5049 5050 vgone(ap->a_vp); 5051 return (0); 5052 } 5053 5054 /* 5055 * The syncer vnode is no longer needed and is being decommissioned. 5056 * 5057 * Modifications to the worklist must be protected by sync_mtx. 5058 */ 5059 static int 5060 sync_reclaim(struct vop_reclaim_args *ap) 5061 { 5062 struct vnode *vp = ap->a_vp; 5063 struct bufobj *bo; 5064 5065 bo = &vp->v_bufobj; 5066 BO_LOCK(bo); 5067 mtx_lock(&sync_mtx); 5068 if (vp->v_mount->mnt_syncer == vp) 5069 vp->v_mount->mnt_syncer = NULL; 5070 if (bo->bo_flag & BO_ONWORKLST) { 5071 LIST_REMOVE(bo, bo_synclist); 5072 syncer_worklist_len--; 5073 sync_vnode_count--; 5074 bo->bo_flag &= ~BO_ONWORKLST; 5075 } 5076 mtx_unlock(&sync_mtx); 5077 BO_UNLOCK(bo); 5078 5079 return (0); 5080 } 5081 5082 int 5083 vn_need_pageq_flush(struct vnode *vp) 5084 { 5085 struct vm_object *obj; 5086 int need; 5087 5088 MPASS(mtx_owned(VI_MTX(vp))); 5089 need = 0; 5090 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5091 vm_object_mightbedirty(obj)) 5092 need = 1; 5093 return (need); 5094 } 5095 5096 /* 5097 * Check if vnode represents a disk device 5098 */ 5099 int 5100 vn_isdisk(struct vnode *vp, int *errp) 5101 { 5102 int error; 5103 5104 if (vp->v_type != VCHR) { 5105 error = ENOTBLK; 5106 goto out; 5107 } 5108 error = 0; 5109 dev_lock(); 5110 if (vp->v_rdev == NULL) 5111 error = ENXIO; 5112 else if (vp->v_rdev->si_devsw == NULL) 5113 error = ENXIO; 5114 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5115 error = ENOTBLK; 5116 dev_unlock(); 5117 out: 5118 if (errp != NULL) 5119 *errp = error; 5120 return (error == 0); 5121 } 5122 5123 /* 5124 * Common filesystem object access control check routine. Accepts a 5125 * vnode's type, "mode", uid and gid, requested access mode, credentials, 5126 * and optional call-by-reference privused argument allowing vaccess() 5127 * to indicate to the caller whether privilege was used to satisfy the 5128 * request (obsoleted). Returns 0 on success, or an errno on failure. 5129 */ 5130 int 5131 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5132 accmode_t accmode, struct ucred *cred, int *privused) 5133 { 5134 accmode_t dac_granted; 5135 accmode_t priv_granted; 5136 5137 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5138 ("invalid bit in accmode")); 5139 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5140 ("VAPPEND without VWRITE")); 5141 5142 /* 5143 * Look for a normal, non-privileged way to access the file/directory 5144 * as requested. If it exists, go with that. 5145 */ 5146 5147 if (privused != NULL) 5148 *privused = 0; 5149 5150 dac_granted = 0; 5151 5152 /* Check the owner. */ 5153 if (cred->cr_uid == file_uid) { 5154 dac_granted |= VADMIN; 5155 if (file_mode & S_IXUSR) 5156 dac_granted |= VEXEC; 5157 if (file_mode & S_IRUSR) 5158 dac_granted |= VREAD; 5159 if (file_mode & S_IWUSR) 5160 dac_granted |= (VWRITE | VAPPEND); 5161 5162 if ((accmode & dac_granted) == accmode) 5163 return (0); 5164 5165 goto privcheck; 5166 } 5167 5168 /* Otherwise, check the groups (first match) */ 5169 if (groupmember(file_gid, cred)) { 5170 if (file_mode & S_IXGRP) 5171 dac_granted |= VEXEC; 5172 if (file_mode & S_IRGRP) 5173 dac_granted |= VREAD; 5174 if (file_mode & S_IWGRP) 5175 dac_granted |= (VWRITE | VAPPEND); 5176 5177 if ((accmode & dac_granted) == accmode) 5178 return (0); 5179 5180 goto privcheck; 5181 } 5182 5183 /* Otherwise, check everyone else. */ 5184 if (file_mode & S_IXOTH) 5185 dac_granted |= VEXEC; 5186 if (file_mode & S_IROTH) 5187 dac_granted |= VREAD; 5188 if (file_mode & S_IWOTH) 5189 dac_granted |= (VWRITE | VAPPEND); 5190 if ((accmode & dac_granted) == accmode) 5191 return (0); 5192 5193 privcheck: 5194 /* 5195 * Build a privilege mask to determine if the set of privileges 5196 * satisfies the requirements when combined with the granted mask 5197 * from above. For each privilege, if the privilege is required, 5198 * bitwise or the request type onto the priv_granted mask. 5199 */ 5200 priv_granted = 0; 5201 5202 if (type == VDIR) { 5203 /* 5204 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5205 * requests, instead of PRIV_VFS_EXEC. 5206 */ 5207 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5208 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5209 priv_granted |= VEXEC; 5210 } else { 5211 /* 5212 * Ensure that at least one execute bit is on. Otherwise, 5213 * a privileged user will always succeed, and we don't want 5214 * this to happen unless the file really is executable. 5215 */ 5216 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5217 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5218 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5219 priv_granted |= VEXEC; 5220 } 5221 5222 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5223 !priv_check_cred(cred, PRIV_VFS_READ)) 5224 priv_granted |= VREAD; 5225 5226 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5227 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5228 priv_granted |= (VWRITE | VAPPEND); 5229 5230 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5231 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5232 priv_granted |= VADMIN; 5233 5234 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5235 /* XXX audit: privilege used */ 5236 if (privused != NULL) 5237 *privused = 1; 5238 return (0); 5239 } 5240 5241 return ((accmode & VADMIN) ? EPERM : EACCES); 5242 } 5243 5244 /* 5245 * Credential check based on process requesting service, and per-attribute 5246 * permissions. 5247 */ 5248 int 5249 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5250 struct thread *td, accmode_t accmode) 5251 { 5252 5253 /* 5254 * Kernel-invoked always succeeds. 5255 */ 5256 if (cred == NOCRED) 5257 return (0); 5258 5259 /* 5260 * Do not allow privileged processes in jail to directly manipulate 5261 * system attributes. 5262 */ 5263 switch (attrnamespace) { 5264 case EXTATTR_NAMESPACE_SYSTEM: 5265 /* Potentially should be: return (EPERM); */ 5266 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5267 case EXTATTR_NAMESPACE_USER: 5268 return (VOP_ACCESS(vp, accmode, cred, td)); 5269 default: 5270 return (EPERM); 5271 } 5272 } 5273 5274 #ifdef DEBUG_VFS_LOCKS 5275 /* 5276 * This only exists to suppress warnings from unlocked specfs accesses. It is 5277 * no longer ok to have an unlocked VFS. 5278 */ 5279 #define IGNORE_LOCK(vp) (KERNEL_PANICKED() || (vp) == NULL || \ 5280 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 5281 5282 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5283 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5284 "Drop into debugger on lock violation"); 5285 5286 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5287 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5288 0, "Check for interlock across VOPs"); 5289 5290 int vfs_badlock_print = 1; /* Print lock violations. */ 5291 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5292 0, "Print lock violations"); 5293 5294 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5295 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5296 0, "Print vnode details on lock violations"); 5297 5298 #ifdef KDB 5299 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5300 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5301 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5302 #endif 5303 5304 static void 5305 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5306 { 5307 5308 #ifdef KDB 5309 if (vfs_badlock_backtrace) 5310 kdb_backtrace(); 5311 #endif 5312 if (vfs_badlock_vnode) 5313 vn_printf(vp, "vnode "); 5314 if (vfs_badlock_print) 5315 printf("%s: %p %s\n", str, (void *)vp, msg); 5316 if (vfs_badlock_ddb) 5317 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5318 } 5319 5320 void 5321 assert_vi_locked(struct vnode *vp, const char *str) 5322 { 5323 5324 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5325 vfs_badlock("interlock is not locked but should be", str, vp); 5326 } 5327 5328 void 5329 assert_vi_unlocked(struct vnode *vp, const char *str) 5330 { 5331 5332 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5333 vfs_badlock("interlock is locked but should not be", str, vp); 5334 } 5335 5336 void 5337 assert_vop_locked(struct vnode *vp, const char *str) 5338 { 5339 int locked; 5340 5341 if (!IGNORE_LOCK(vp)) { 5342 locked = VOP_ISLOCKED(vp); 5343 if (locked == 0 || locked == LK_EXCLOTHER) 5344 vfs_badlock("is not locked but should be", str, vp); 5345 } 5346 } 5347 5348 void 5349 assert_vop_unlocked(struct vnode *vp, const char *str) 5350 { 5351 5352 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5353 vfs_badlock("is locked but should not be", str, vp); 5354 } 5355 5356 void 5357 assert_vop_elocked(struct vnode *vp, const char *str) 5358 { 5359 5360 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5361 vfs_badlock("is not exclusive locked but should be", str, vp); 5362 } 5363 #endif /* DEBUG_VFS_LOCKS */ 5364 5365 void 5366 vop_rename_fail(struct vop_rename_args *ap) 5367 { 5368 5369 if (ap->a_tvp != NULL) 5370 vput(ap->a_tvp); 5371 if (ap->a_tdvp == ap->a_tvp) 5372 vrele(ap->a_tdvp); 5373 else 5374 vput(ap->a_tdvp); 5375 vrele(ap->a_fdvp); 5376 vrele(ap->a_fvp); 5377 } 5378 5379 void 5380 vop_rename_pre(void *ap) 5381 { 5382 struct vop_rename_args *a = ap; 5383 5384 #ifdef DEBUG_VFS_LOCKS 5385 if (a->a_tvp) 5386 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5387 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5388 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5389 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5390 5391 /* Check the source (from). */ 5392 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5393 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5394 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5395 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5396 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5397 5398 /* Check the target. */ 5399 if (a->a_tvp) 5400 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5401 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5402 #endif 5403 if (a->a_tdvp != a->a_fdvp) 5404 vhold(a->a_fdvp); 5405 if (a->a_tvp != a->a_fvp) 5406 vhold(a->a_fvp); 5407 vhold(a->a_tdvp); 5408 if (a->a_tvp) 5409 vhold(a->a_tvp); 5410 } 5411 5412 #ifdef DEBUG_VFS_LOCKS 5413 void 5414 vop_strategy_pre(void *ap) 5415 { 5416 struct vop_strategy_args *a; 5417 struct buf *bp; 5418 5419 a = ap; 5420 bp = a->a_bp; 5421 5422 /* 5423 * Cluster ops lock their component buffers but not the IO container. 5424 */ 5425 if ((bp->b_flags & B_CLUSTER) != 0) 5426 return; 5427 5428 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5429 if (vfs_badlock_print) 5430 printf( 5431 "VOP_STRATEGY: bp is not locked but should be\n"); 5432 if (vfs_badlock_ddb) 5433 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5434 } 5435 } 5436 5437 void 5438 vop_lock_pre(void *ap) 5439 { 5440 struct vop_lock1_args *a = ap; 5441 5442 if ((a->a_flags & LK_INTERLOCK) == 0) 5443 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5444 else 5445 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5446 } 5447 5448 void 5449 vop_lock_post(void *ap, int rc) 5450 { 5451 struct vop_lock1_args *a = ap; 5452 5453 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5454 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5455 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5456 } 5457 5458 void 5459 vop_unlock_pre(void *ap) 5460 { 5461 struct vop_unlock_args *a = ap; 5462 5463 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5464 } 5465 5466 void 5467 vop_need_inactive_pre(void *ap) 5468 { 5469 struct vop_need_inactive_args *a = ap; 5470 5471 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5472 } 5473 5474 void 5475 vop_need_inactive_post(void *ap, int rc) 5476 { 5477 struct vop_need_inactive_args *a = ap; 5478 5479 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5480 } 5481 #endif 5482 5483 void 5484 vop_create_post(void *ap, int rc) 5485 { 5486 struct vop_create_args *a = ap; 5487 5488 if (!rc) 5489 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5490 } 5491 5492 void 5493 vop_deleteextattr_post(void *ap, int rc) 5494 { 5495 struct vop_deleteextattr_args *a = ap; 5496 5497 if (!rc) 5498 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5499 } 5500 5501 void 5502 vop_link_post(void *ap, int rc) 5503 { 5504 struct vop_link_args *a = ap; 5505 5506 if (!rc) { 5507 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 5508 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 5509 } 5510 } 5511 5512 void 5513 vop_mkdir_post(void *ap, int rc) 5514 { 5515 struct vop_mkdir_args *a = ap; 5516 5517 if (!rc) 5518 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5519 } 5520 5521 void 5522 vop_mknod_post(void *ap, int rc) 5523 { 5524 struct vop_mknod_args *a = ap; 5525 5526 if (!rc) 5527 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5528 } 5529 5530 void 5531 vop_reclaim_post(void *ap, int rc) 5532 { 5533 struct vop_reclaim_args *a = ap; 5534 5535 if (!rc) 5536 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 5537 } 5538 5539 void 5540 vop_remove_post(void *ap, int rc) 5541 { 5542 struct vop_remove_args *a = ap; 5543 5544 if (!rc) { 5545 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5546 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5547 } 5548 } 5549 5550 void 5551 vop_rename_post(void *ap, int rc) 5552 { 5553 struct vop_rename_args *a = ap; 5554 long hint; 5555 5556 if (!rc) { 5557 hint = NOTE_WRITE; 5558 if (a->a_fdvp == a->a_tdvp) { 5559 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5560 hint |= NOTE_LINK; 5561 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5562 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5563 } else { 5564 hint |= NOTE_EXTEND; 5565 if (a->a_fvp->v_type == VDIR) 5566 hint |= NOTE_LINK; 5567 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5568 5569 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5570 a->a_tvp->v_type == VDIR) 5571 hint &= ~NOTE_LINK; 5572 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5573 } 5574 5575 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5576 if (a->a_tvp) 5577 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5578 } 5579 if (a->a_tdvp != a->a_fdvp) 5580 vdrop(a->a_fdvp); 5581 if (a->a_tvp != a->a_fvp) 5582 vdrop(a->a_fvp); 5583 vdrop(a->a_tdvp); 5584 if (a->a_tvp) 5585 vdrop(a->a_tvp); 5586 } 5587 5588 void 5589 vop_rmdir_post(void *ap, int rc) 5590 { 5591 struct vop_rmdir_args *a = ap; 5592 5593 if (!rc) { 5594 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5595 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5596 } 5597 } 5598 5599 void 5600 vop_setattr_post(void *ap, int rc) 5601 { 5602 struct vop_setattr_args *a = ap; 5603 5604 if (!rc) 5605 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5606 } 5607 5608 void 5609 vop_setextattr_post(void *ap, int rc) 5610 { 5611 struct vop_setextattr_args *a = ap; 5612 5613 if (!rc) 5614 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5615 } 5616 5617 void 5618 vop_symlink_post(void *ap, int rc) 5619 { 5620 struct vop_symlink_args *a = ap; 5621 5622 if (!rc) 5623 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5624 } 5625 5626 void 5627 vop_open_post(void *ap, int rc) 5628 { 5629 struct vop_open_args *a = ap; 5630 5631 if (!rc) 5632 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5633 } 5634 5635 void 5636 vop_close_post(void *ap, int rc) 5637 { 5638 struct vop_close_args *a = ap; 5639 5640 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5641 !VN_IS_DOOMED(a->a_vp))) { 5642 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5643 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5644 } 5645 } 5646 5647 void 5648 vop_read_post(void *ap, int rc) 5649 { 5650 struct vop_read_args *a = ap; 5651 5652 if (!rc) 5653 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5654 } 5655 5656 void 5657 vop_readdir_post(void *ap, int rc) 5658 { 5659 struct vop_readdir_args *a = ap; 5660 5661 if (!rc) 5662 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5663 } 5664 5665 static struct knlist fs_knlist; 5666 5667 static void 5668 vfs_event_init(void *arg) 5669 { 5670 knlist_init_mtx(&fs_knlist, NULL); 5671 } 5672 /* XXX - correct order? */ 5673 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5674 5675 void 5676 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5677 { 5678 5679 KNOTE_UNLOCKED(&fs_knlist, event); 5680 } 5681 5682 static int filt_fsattach(struct knote *kn); 5683 static void filt_fsdetach(struct knote *kn); 5684 static int filt_fsevent(struct knote *kn, long hint); 5685 5686 struct filterops fs_filtops = { 5687 .f_isfd = 0, 5688 .f_attach = filt_fsattach, 5689 .f_detach = filt_fsdetach, 5690 .f_event = filt_fsevent 5691 }; 5692 5693 static int 5694 filt_fsattach(struct knote *kn) 5695 { 5696 5697 kn->kn_flags |= EV_CLEAR; 5698 knlist_add(&fs_knlist, kn, 0); 5699 return (0); 5700 } 5701 5702 static void 5703 filt_fsdetach(struct knote *kn) 5704 { 5705 5706 knlist_remove(&fs_knlist, kn, 0); 5707 } 5708 5709 static int 5710 filt_fsevent(struct knote *kn, long hint) 5711 { 5712 5713 kn->kn_fflags |= hint; 5714 return (kn->kn_fflags != 0); 5715 } 5716 5717 static int 5718 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5719 { 5720 struct vfsidctl vc; 5721 int error; 5722 struct mount *mp; 5723 5724 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5725 if (error) 5726 return (error); 5727 if (vc.vc_vers != VFS_CTL_VERS1) 5728 return (EINVAL); 5729 mp = vfs_getvfs(&vc.vc_fsid); 5730 if (mp == NULL) 5731 return (ENOENT); 5732 /* ensure that a specific sysctl goes to the right filesystem. */ 5733 if (strcmp(vc.vc_fstypename, "*") != 0 && 5734 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5735 vfs_rel(mp); 5736 return (EINVAL); 5737 } 5738 VCTLTOREQ(&vc, req); 5739 error = VFS_SYSCTL(mp, vc.vc_op, req); 5740 vfs_rel(mp); 5741 return (error); 5742 } 5743 5744 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 5745 NULL, 0, sysctl_vfs_ctl, "", 5746 "Sysctl by fsid"); 5747 5748 /* 5749 * Function to initialize a va_filerev field sensibly. 5750 * XXX: Wouldn't a random number make a lot more sense ?? 5751 */ 5752 u_quad_t 5753 init_va_filerev(void) 5754 { 5755 struct bintime bt; 5756 5757 getbinuptime(&bt); 5758 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5759 } 5760 5761 static int filt_vfsread(struct knote *kn, long hint); 5762 static int filt_vfswrite(struct knote *kn, long hint); 5763 static int filt_vfsvnode(struct knote *kn, long hint); 5764 static void filt_vfsdetach(struct knote *kn); 5765 static struct filterops vfsread_filtops = { 5766 .f_isfd = 1, 5767 .f_detach = filt_vfsdetach, 5768 .f_event = filt_vfsread 5769 }; 5770 static struct filterops vfswrite_filtops = { 5771 .f_isfd = 1, 5772 .f_detach = filt_vfsdetach, 5773 .f_event = filt_vfswrite 5774 }; 5775 static struct filterops vfsvnode_filtops = { 5776 .f_isfd = 1, 5777 .f_detach = filt_vfsdetach, 5778 .f_event = filt_vfsvnode 5779 }; 5780 5781 static void 5782 vfs_knllock(void *arg) 5783 { 5784 struct vnode *vp = arg; 5785 5786 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5787 } 5788 5789 static void 5790 vfs_knlunlock(void *arg) 5791 { 5792 struct vnode *vp = arg; 5793 5794 VOP_UNLOCK(vp); 5795 } 5796 5797 static void 5798 vfs_knl_assert_locked(void *arg) 5799 { 5800 #ifdef DEBUG_VFS_LOCKS 5801 struct vnode *vp = arg; 5802 5803 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5804 #endif 5805 } 5806 5807 static void 5808 vfs_knl_assert_unlocked(void *arg) 5809 { 5810 #ifdef DEBUG_VFS_LOCKS 5811 struct vnode *vp = arg; 5812 5813 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5814 #endif 5815 } 5816 5817 int 5818 vfs_kqfilter(struct vop_kqfilter_args *ap) 5819 { 5820 struct vnode *vp = ap->a_vp; 5821 struct knote *kn = ap->a_kn; 5822 struct knlist *knl; 5823 5824 switch (kn->kn_filter) { 5825 case EVFILT_READ: 5826 kn->kn_fop = &vfsread_filtops; 5827 break; 5828 case EVFILT_WRITE: 5829 kn->kn_fop = &vfswrite_filtops; 5830 break; 5831 case EVFILT_VNODE: 5832 kn->kn_fop = &vfsvnode_filtops; 5833 break; 5834 default: 5835 return (EINVAL); 5836 } 5837 5838 kn->kn_hook = (caddr_t)vp; 5839 5840 v_addpollinfo(vp); 5841 if (vp->v_pollinfo == NULL) 5842 return (ENOMEM); 5843 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5844 vhold(vp); 5845 knlist_add(knl, kn, 0); 5846 5847 return (0); 5848 } 5849 5850 /* 5851 * Detach knote from vnode 5852 */ 5853 static void 5854 filt_vfsdetach(struct knote *kn) 5855 { 5856 struct vnode *vp = (struct vnode *)kn->kn_hook; 5857 5858 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5859 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5860 vdrop(vp); 5861 } 5862 5863 /*ARGSUSED*/ 5864 static int 5865 filt_vfsread(struct knote *kn, long hint) 5866 { 5867 struct vnode *vp = (struct vnode *)kn->kn_hook; 5868 struct vattr va; 5869 int res; 5870 5871 /* 5872 * filesystem is gone, so set the EOF flag and schedule 5873 * the knote for deletion. 5874 */ 5875 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5876 VI_LOCK(vp); 5877 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5878 VI_UNLOCK(vp); 5879 return (1); 5880 } 5881 5882 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5883 return (0); 5884 5885 VI_LOCK(vp); 5886 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5887 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5888 VI_UNLOCK(vp); 5889 return (res); 5890 } 5891 5892 /*ARGSUSED*/ 5893 static int 5894 filt_vfswrite(struct knote *kn, long hint) 5895 { 5896 struct vnode *vp = (struct vnode *)kn->kn_hook; 5897 5898 VI_LOCK(vp); 5899 5900 /* 5901 * filesystem is gone, so set the EOF flag and schedule 5902 * the knote for deletion. 5903 */ 5904 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5905 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5906 5907 kn->kn_data = 0; 5908 VI_UNLOCK(vp); 5909 return (1); 5910 } 5911 5912 static int 5913 filt_vfsvnode(struct knote *kn, long hint) 5914 { 5915 struct vnode *vp = (struct vnode *)kn->kn_hook; 5916 int res; 5917 5918 VI_LOCK(vp); 5919 if (kn->kn_sfflags & hint) 5920 kn->kn_fflags |= hint; 5921 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5922 kn->kn_flags |= EV_EOF; 5923 VI_UNLOCK(vp); 5924 return (1); 5925 } 5926 res = (kn->kn_fflags != 0); 5927 VI_UNLOCK(vp); 5928 return (res); 5929 } 5930 5931 /* 5932 * Returns whether the directory is empty or not. 5933 * If it is empty, the return value is 0; otherwise 5934 * the return value is an error value (which may 5935 * be ENOTEMPTY). 5936 */ 5937 int 5938 vfs_emptydir(struct vnode *vp) 5939 { 5940 struct uio uio; 5941 struct iovec iov; 5942 struct dirent *dirent, *dp, *endp; 5943 int error, eof; 5944 5945 error = 0; 5946 eof = 0; 5947 5948 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 5949 5950 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 5951 iov.iov_base = dirent; 5952 iov.iov_len = sizeof(struct dirent); 5953 5954 uio.uio_iov = &iov; 5955 uio.uio_iovcnt = 1; 5956 uio.uio_offset = 0; 5957 uio.uio_resid = sizeof(struct dirent); 5958 uio.uio_segflg = UIO_SYSSPACE; 5959 uio.uio_rw = UIO_READ; 5960 uio.uio_td = curthread; 5961 5962 while (eof == 0 && error == 0) { 5963 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 5964 NULL, NULL); 5965 if (error != 0) 5966 break; 5967 endp = (void *)((uint8_t *)dirent + 5968 sizeof(struct dirent) - uio.uio_resid); 5969 for (dp = dirent; dp < endp; 5970 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 5971 if (dp->d_type == DT_WHT) 5972 continue; 5973 if (dp->d_namlen == 0) 5974 continue; 5975 if (dp->d_type != DT_DIR && 5976 dp->d_type != DT_UNKNOWN) { 5977 error = ENOTEMPTY; 5978 break; 5979 } 5980 if (dp->d_namlen > 2) { 5981 error = ENOTEMPTY; 5982 break; 5983 } 5984 if (dp->d_namlen == 1 && 5985 dp->d_name[0] != '.') { 5986 error = ENOTEMPTY; 5987 break; 5988 } 5989 if (dp->d_namlen == 2 && 5990 dp->d_name[1] != '.') { 5991 error = ENOTEMPTY; 5992 break; 5993 } 5994 uio.uio_resid = sizeof(struct dirent); 5995 } 5996 } 5997 free(dirent, M_TEMP); 5998 return (error); 5999 } 6000 6001 int 6002 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 6003 { 6004 int error; 6005 6006 if (dp->d_reclen > ap->a_uio->uio_resid) 6007 return (ENAMETOOLONG); 6008 error = uiomove(dp, dp->d_reclen, ap->a_uio); 6009 if (error) { 6010 if (ap->a_ncookies != NULL) { 6011 if (ap->a_cookies != NULL) 6012 free(ap->a_cookies, M_TEMP); 6013 ap->a_cookies = NULL; 6014 *ap->a_ncookies = 0; 6015 } 6016 return (error); 6017 } 6018 if (ap->a_ncookies == NULL) 6019 return (0); 6020 6021 KASSERT(ap->a_cookies, 6022 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 6023 6024 *ap->a_cookies = realloc(*ap->a_cookies, 6025 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 6026 (*ap->a_cookies)[*ap->a_ncookies] = off; 6027 *ap->a_ncookies += 1; 6028 return (0); 6029 } 6030 6031 /* 6032 * The purpose of this routine is to remove granularity from accmode_t, 6033 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 6034 * VADMIN and VAPPEND. 6035 * 6036 * If it returns 0, the caller is supposed to continue with the usual 6037 * access checks using 'accmode' as modified by this routine. If it 6038 * returns nonzero value, the caller is supposed to return that value 6039 * as errno. 6040 * 6041 * Note that after this routine runs, accmode may be zero. 6042 */ 6043 int 6044 vfs_unixify_accmode(accmode_t *accmode) 6045 { 6046 /* 6047 * There is no way to specify explicit "deny" rule using 6048 * file mode or POSIX.1e ACLs. 6049 */ 6050 if (*accmode & VEXPLICIT_DENY) { 6051 *accmode = 0; 6052 return (0); 6053 } 6054 6055 /* 6056 * None of these can be translated into usual access bits. 6057 * Also, the common case for NFSv4 ACLs is to not contain 6058 * either of these bits. Caller should check for VWRITE 6059 * on the containing directory instead. 6060 */ 6061 if (*accmode & (VDELETE_CHILD | VDELETE)) 6062 return (EPERM); 6063 6064 if (*accmode & VADMIN_PERMS) { 6065 *accmode &= ~VADMIN_PERMS; 6066 *accmode |= VADMIN; 6067 } 6068 6069 /* 6070 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6071 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6072 */ 6073 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6074 6075 return (0); 6076 } 6077 6078 /* 6079 * Clear out a doomed vnode (if any) and replace it with a new one as long 6080 * as the fs is not being unmounted. Return the root vnode to the caller. 6081 */ 6082 static int __noinline 6083 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6084 { 6085 struct vnode *vp; 6086 int error; 6087 6088 restart: 6089 if (mp->mnt_rootvnode != NULL) { 6090 MNT_ILOCK(mp); 6091 vp = mp->mnt_rootvnode; 6092 if (vp != NULL) { 6093 if (!VN_IS_DOOMED(vp)) { 6094 vrefact(vp); 6095 MNT_IUNLOCK(mp); 6096 error = vn_lock(vp, flags); 6097 if (error == 0) { 6098 *vpp = vp; 6099 return (0); 6100 } 6101 vrele(vp); 6102 goto restart; 6103 } 6104 /* 6105 * Clear the old one. 6106 */ 6107 mp->mnt_rootvnode = NULL; 6108 } 6109 MNT_IUNLOCK(mp); 6110 if (vp != NULL) { 6111 vfs_op_barrier_wait(mp); 6112 vrele(vp); 6113 } 6114 } 6115 error = VFS_CACHEDROOT(mp, flags, vpp); 6116 if (error != 0) 6117 return (error); 6118 if (mp->mnt_vfs_ops == 0) { 6119 MNT_ILOCK(mp); 6120 if (mp->mnt_vfs_ops != 0) { 6121 MNT_IUNLOCK(mp); 6122 return (0); 6123 } 6124 if (mp->mnt_rootvnode == NULL) { 6125 vrefact(*vpp); 6126 mp->mnt_rootvnode = *vpp; 6127 } else { 6128 if (mp->mnt_rootvnode != *vpp) { 6129 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6130 panic("%s: mismatch between vnode returned " 6131 " by VFS_CACHEDROOT and the one cached " 6132 " (%p != %p)", 6133 __func__, *vpp, mp->mnt_rootvnode); 6134 } 6135 } 6136 } 6137 MNT_IUNLOCK(mp); 6138 } 6139 return (0); 6140 } 6141 6142 int 6143 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6144 { 6145 struct vnode *vp; 6146 int error; 6147 6148 if (!vfs_op_thread_enter(mp)) 6149 return (vfs_cache_root_fallback(mp, flags, vpp)); 6150 vp = atomic_load_ptr(&mp->mnt_rootvnode); 6151 if (vp == NULL || VN_IS_DOOMED(vp)) { 6152 vfs_op_thread_exit(mp); 6153 return (vfs_cache_root_fallback(mp, flags, vpp)); 6154 } 6155 vrefact(vp); 6156 vfs_op_thread_exit(mp); 6157 error = vn_lock(vp, flags); 6158 if (error != 0) { 6159 vrele(vp); 6160 return (vfs_cache_root_fallback(mp, flags, vpp)); 6161 } 6162 *vpp = vp; 6163 return (0); 6164 } 6165 6166 struct vnode * 6167 vfs_cache_root_clear(struct mount *mp) 6168 { 6169 struct vnode *vp; 6170 6171 /* 6172 * ops > 0 guarantees there is nobody who can see this vnode 6173 */ 6174 MPASS(mp->mnt_vfs_ops > 0); 6175 vp = mp->mnt_rootvnode; 6176 mp->mnt_rootvnode = NULL; 6177 return (vp); 6178 } 6179 6180 void 6181 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6182 { 6183 6184 MPASS(mp->mnt_vfs_ops > 0); 6185 vrefact(vp); 6186 mp->mnt_rootvnode = vp; 6187 } 6188 6189 /* 6190 * These are helper functions for filesystems to traverse all 6191 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6192 * 6193 * This interface replaces MNT_VNODE_FOREACH. 6194 */ 6195 6196 struct vnode * 6197 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6198 { 6199 struct vnode *vp; 6200 6201 if (should_yield()) 6202 kern_yield(PRI_USER); 6203 MNT_ILOCK(mp); 6204 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6205 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6206 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6207 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6208 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6209 continue; 6210 VI_LOCK(vp); 6211 if (VN_IS_DOOMED(vp)) { 6212 VI_UNLOCK(vp); 6213 continue; 6214 } 6215 break; 6216 } 6217 if (vp == NULL) { 6218 __mnt_vnode_markerfree_all(mvp, mp); 6219 /* MNT_IUNLOCK(mp); -- done in above function */ 6220 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6221 return (NULL); 6222 } 6223 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6224 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6225 MNT_IUNLOCK(mp); 6226 return (vp); 6227 } 6228 6229 struct vnode * 6230 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6231 { 6232 struct vnode *vp; 6233 6234 *mvp = vn_alloc_marker(mp); 6235 MNT_ILOCK(mp); 6236 MNT_REF(mp); 6237 6238 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6239 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6240 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6241 continue; 6242 VI_LOCK(vp); 6243 if (VN_IS_DOOMED(vp)) { 6244 VI_UNLOCK(vp); 6245 continue; 6246 } 6247 break; 6248 } 6249 if (vp == NULL) { 6250 MNT_REL(mp); 6251 MNT_IUNLOCK(mp); 6252 vn_free_marker(*mvp); 6253 *mvp = NULL; 6254 return (NULL); 6255 } 6256 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6257 MNT_IUNLOCK(mp); 6258 return (vp); 6259 } 6260 6261 void 6262 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6263 { 6264 6265 if (*mvp == NULL) { 6266 MNT_IUNLOCK(mp); 6267 return; 6268 } 6269 6270 mtx_assert(MNT_MTX(mp), MA_OWNED); 6271 6272 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6273 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6274 MNT_REL(mp); 6275 MNT_IUNLOCK(mp); 6276 vn_free_marker(*mvp); 6277 *mvp = NULL; 6278 } 6279 6280 /* 6281 * These are helper functions for filesystems to traverse their 6282 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6283 */ 6284 static void 6285 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6286 { 6287 6288 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6289 6290 MNT_ILOCK(mp); 6291 MNT_REL(mp); 6292 MNT_IUNLOCK(mp); 6293 vn_free_marker(*mvp); 6294 *mvp = NULL; 6295 } 6296 6297 /* 6298 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6299 * conventional lock order during mnt_vnode_next_lazy iteration. 6300 * 6301 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6302 * The list lock is dropped and reacquired. On success, both locks are held. 6303 * On failure, the mount vnode list lock is held but the vnode interlock is 6304 * not, and the procedure may have yielded. 6305 */ 6306 static bool 6307 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6308 struct vnode *vp) 6309 { 6310 6311 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6312 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6313 ("%s: bad marker", __func__)); 6314 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6315 ("%s: inappropriate vnode", __func__)); 6316 ASSERT_VI_UNLOCKED(vp, __func__); 6317 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6318 6319 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6320 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6321 6322 /* 6323 * Note we may be racing against vdrop which transitioned the hold 6324 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine, 6325 * if we are the only user after we get the interlock we will just 6326 * vdrop. 6327 */ 6328 vhold(vp); 6329 mtx_unlock(&mp->mnt_listmtx); 6330 VI_LOCK(vp); 6331 if (VN_IS_DOOMED(vp)) { 6332 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6333 goto out_lost; 6334 } 6335 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6336 /* 6337 * There is nothing to do if we are the last user. 6338 */ 6339 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6340 goto out_lost; 6341 mtx_lock(&mp->mnt_listmtx); 6342 return (true); 6343 out_lost: 6344 vdropl(vp); 6345 maybe_yield(); 6346 mtx_lock(&mp->mnt_listmtx); 6347 return (false); 6348 } 6349 6350 static struct vnode * 6351 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6352 void *cbarg) 6353 { 6354 struct vnode *vp; 6355 6356 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6357 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6358 restart: 6359 vp = TAILQ_NEXT(*mvp, v_lazylist); 6360 while (vp != NULL) { 6361 if (vp->v_type == VMARKER) { 6362 vp = TAILQ_NEXT(vp, v_lazylist); 6363 continue; 6364 } 6365 /* 6366 * See if we want to process the vnode. Note we may encounter a 6367 * long string of vnodes we don't care about and hog the list 6368 * as a result. Check for it and requeue the marker. 6369 */ 6370 VNPASS(!VN_IS_DOOMED(vp), vp); 6371 if (!cb(vp, cbarg)) { 6372 if (!should_yield()) { 6373 vp = TAILQ_NEXT(vp, v_lazylist); 6374 continue; 6375 } 6376 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 6377 v_lazylist); 6378 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 6379 v_lazylist); 6380 mtx_unlock(&mp->mnt_listmtx); 6381 kern_yield(PRI_USER); 6382 mtx_lock(&mp->mnt_listmtx); 6383 goto restart; 6384 } 6385 /* 6386 * Try-lock because this is the wrong lock order. 6387 */ 6388 if (!VI_TRYLOCK(vp) && 6389 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 6390 goto restart; 6391 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 6392 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 6393 ("alien vnode on the lazy list %p %p", vp, mp)); 6394 VNPASS(vp->v_mount == mp, vp); 6395 VNPASS(!VN_IS_DOOMED(vp), vp); 6396 break; 6397 } 6398 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6399 6400 /* Check if we are done */ 6401 if (vp == NULL) { 6402 mtx_unlock(&mp->mnt_listmtx); 6403 mnt_vnode_markerfree_lazy(mvp, mp); 6404 return (NULL); 6405 } 6406 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 6407 mtx_unlock(&mp->mnt_listmtx); 6408 ASSERT_VI_LOCKED(vp, "lazy iter"); 6409 return (vp); 6410 } 6411 6412 struct vnode * 6413 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6414 void *cbarg) 6415 { 6416 6417 if (should_yield()) 6418 kern_yield(PRI_USER); 6419 mtx_lock(&mp->mnt_listmtx); 6420 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6421 } 6422 6423 struct vnode * 6424 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6425 void *cbarg) 6426 { 6427 struct vnode *vp; 6428 6429 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 6430 return (NULL); 6431 6432 *mvp = vn_alloc_marker(mp); 6433 MNT_ILOCK(mp); 6434 MNT_REF(mp); 6435 MNT_IUNLOCK(mp); 6436 6437 mtx_lock(&mp->mnt_listmtx); 6438 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 6439 if (vp == NULL) { 6440 mtx_unlock(&mp->mnt_listmtx); 6441 mnt_vnode_markerfree_lazy(mvp, mp); 6442 return (NULL); 6443 } 6444 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 6445 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6446 } 6447 6448 void 6449 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6450 { 6451 6452 if (*mvp == NULL) 6453 return; 6454 6455 mtx_lock(&mp->mnt_listmtx); 6456 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6457 mtx_unlock(&mp->mnt_listmtx); 6458 mnt_vnode_markerfree_lazy(mvp, mp); 6459 } 6460 6461 int 6462 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 6463 { 6464 6465 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 6466 cnp->cn_flags &= ~NOEXECCHECK; 6467 return (0); 6468 } 6469 6470 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread)); 6471 } 6472