1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 37 */ 38 39 /* 40 * External virtual filesystem routines 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_ddb.h" 47 #include "opt_watchdog.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/bio.h> 52 #include <sys/buf.h> 53 #include <sys/capsicum.h> 54 #include <sys/condvar.h> 55 #include <sys/conf.h> 56 #include <sys/counter.h> 57 #include <sys/dirent.h> 58 #include <sys/event.h> 59 #include <sys/eventhandler.h> 60 #include <sys/extattr.h> 61 #include <sys/file.h> 62 #include <sys/fcntl.h> 63 #include <sys/jail.h> 64 #include <sys/kdb.h> 65 #include <sys/kernel.h> 66 #include <sys/kthread.h> 67 #include <sys/ktr.h> 68 #include <sys/lockf.h> 69 #include <sys/malloc.h> 70 #include <sys/mount.h> 71 #include <sys/namei.h> 72 #include <sys/pctrie.h> 73 #include <sys/priv.h> 74 #include <sys/reboot.h> 75 #include <sys/refcount.h> 76 #include <sys/rwlock.h> 77 #include <sys/sched.h> 78 #include <sys/sleepqueue.h> 79 #include <sys/smp.h> 80 #include <sys/stat.h> 81 #include <sys/sysctl.h> 82 #include <sys/syslog.h> 83 #include <sys/vmmeter.h> 84 #include <sys/vnode.h> 85 #include <sys/watchdog.h> 86 87 #include <machine/stdarg.h> 88 89 #include <security/mac/mac_framework.h> 90 91 #include <vm/vm.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_extern.h> 94 #include <vm/pmap.h> 95 #include <vm/vm_map.h> 96 #include <vm/vm_page.h> 97 #include <vm/vm_kern.h> 98 #include <vm/uma.h> 99 100 #ifdef DDB 101 #include <ddb/ddb.h> 102 #endif 103 104 static void delmntque(struct vnode *vp); 105 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 106 int slpflag, int slptimeo); 107 static void syncer_shutdown(void *arg, int howto); 108 static int vtryrecycle(struct vnode *vp); 109 static void v_init_counters(struct vnode *); 110 static void v_incr_devcount(struct vnode *); 111 static void v_decr_devcount(struct vnode *); 112 static void vgonel(struct vnode *); 113 static void vfs_knllock(void *arg); 114 static void vfs_knlunlock(void *arg); 115 static void vfs_knl_assert_locked(void *arg); 116 static void vfs_knl_assert_unlocked(void *arg); 117 static void destroy_vpollinfo(struct vpollinfo *vi); 118 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 119 daddr_t startlbn, daddr_t endlbn); 120 static void vnlru_recalc(void); 121 122 /* 123 * These fences are intended for cases where some synchronization is 124 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 125 * and v_usecount) updates. Access to v_iflags is generally synchronized 126 * by the interlock, but we have some internal assertions that check vnode 127 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 128 * for now. 129 */ 130 #ifdef INVARIANTS 131 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 132 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 133 #else 134 #define VNODE_REFCOUNT_FENCE_ACQ() 135 #define VNODE_REFCOUNT_FENCE_REL() 136 #endif 137 138 /* 139 * Number of vnodes in existence. Increased whenever getnewvnode() 140 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode. 141 */ 142 static u_long __exclusive_cache_line numvnodes; 143 144 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 145 "Number of vnodes in existence"); 146 147 static counter_u64_t vnodes_created; 148 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 149 "Number of vnodes created by getnewvnode"); 150 151 /* 152 * Conversion tables for conversion from vnode types to inode formats 153 * and back. 154 */ 155 enum vtype iftovt_tab[16] = { 156 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 157 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 158 }; 159 int vttoif_tab[10] = { 160 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 161 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 162 }; 163 164 /* 165 * List of allocates vnodes in the system. 166 */ 167 static TAILQ_HEAD(freelst, vnode) vnode_list; 168 static struct vnode *vnode_list_free_marker; 169 static struct vnode *vnode_list_reclaim_marker; 170 171 /* 172 * "Free" vnode target. Free vnodes are rarely completely free, but are 173 * just ones that are cheap to recycle. Usually they are for files which 174 * have been stat'd but not read; these usually have inode and namecache 175 * data attached to them. This target is the preferred minimum size of a 176 * sub-cache consisting mostly of such files. The system balances the size 177 * of this sub-cache with its complement to try to prevent either from 178 * thrashing while the other is relatively inactive. The targets express 179 * a preference for the best balance. 180 * 181 * "Above" this target there are 2 further targets (watermarks) related 182 * to recyling of free vnodes. In the best-operating case, the cache is 183 * exactly full, the free list has size between vlowat and vhiwat above the 184 * free target, and recycling from it and normal use maintains this state. 185 * Sometimes the free list is below vlowat or even empty, but this state 186 * is even better for immediate use provided the cache is not full. 187 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 188 * ones) to reach one of these states. The watermarks are currently hard- 189 * coded as 4% and 9% of the available space higher. These and the default 190 * of 25% for wantfreevnodes are too large if the memory size is large. 191 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 192 * whenever vnlru_proc() becomes active. 193 */ 194 static long wantfreevnodes; 195 static long __exclusive_cache_line freevnodes; 196 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 197 &freevnodes, 0, "Number of \"free\" vnodes"); 198 static long freevnodes_old; 199 200 static counter_u64_t recycles_count; 201 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 202 "Number of vnodes recycled to meet vnode cache targets"); 203 204 static counter_u64_t recycles_free_count; 205 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD, &recycles_free_count, 206 "Number of free vnodes recycled to meet vnode cache targets"); 207 208 /* 209 * Various variables used for debugging the new implementation of 210 * reassignbuf(). 211 * XXX these are probably of (very) limited utility now. 212 */ 213 static int reassignbufcalls; 214 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW | CTLFLAG_STATS, 215 &reassignbufcalls, 0, "Number of calls to reassignbuf"); 216 217 static counter_u64_t deferred_inact; 218 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD, &deferred_inact, 219 "Number of times inactive processing was deferred"); 220 221 /* To keep more than one thread at a time from running vfs_getnewfsid */ 222 static struct mtx mntid_mtx; 223 224 /* 225 * Lock for any access to the following: 226 * vnode_list 227 * numvnodes 228 * freevnodes 229 */ 230 static struct mtx __exclusive_cache_line vnode_list_mtx; 231 232 /* Publicly exported FS */ 233 struct nfs_public nfs_pub; 234 235 static uma_zone_t buf_trie_zone; 236 237 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 238 static uma_zone_t vnode_zone; 239 static uma_zone_t vnodepoll_zone; 240 241 /* 242 * The workitem queue. 243 * 244 * It is useful to delay writes of file data and filesystem metadata 245 * for tens of seconds so that quickly created and deleted files need 246 * not waste disk bandwidth being created and removed. To realize this, 247 * we append vnodes to a "workitem" queue. When running with a soft 248 * updates implementation, most pending metadata dependencies should 249 * not wait for more than a few seconds. Thus, mounted on block devices 250 * are delayed only about a half the time that file data is delayed. 251 * Similarly, directory updates are more critical, so are only delayed 252 * about a third the time that file data is delayed. Thus, there are 253 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 254 * one each second (driven off the filesystem syncer process). The 255 * syncer_delayno variable indicates the next queue that is to be processed. 256 * Items that need to be processed soon are placed in this queue: 257 * 258 * syncer_workitem_pending[syncer_delayno] 259 * 260 * A delay of fifteen seconds is done by placing the request fifteen 261 * entries later in the queue: 262 * 263 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 264 * 265 */ 266 static int syncer_delayno; 267 static long syncer_mask; 268 LIST_HEAD(synclist, bufobj); 269 static struct synclist *syncer_workitem_pending; 270 /* 271 * The sync_mtx protects: 272 * bo->bo_synclist 273 * sync_vnode_count 274 * syncer_delayno 275 * syncer_state 276 * syncer_workitem_pending 277 * syncer_worklist_len 278 * rushjob 279 */ 280 static struct mtx sync_mtx; 281 static struct cv sync_wakeup; 282 283 #define SYNCER_MAXDELAY 32 284 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 285 static int syncdelay = 30; /* max time to delay syncing data */ 286 static int filedelay = 30; /* time to delay syncing files */ 287 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 288 "Time to delay syncing files (in seconds)"); 289 static int dirdelay = 29; /* time to delay syncing directories */ 290 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 291 "Time to delay syncing directories (in seconds)"); 292 static int metadelay = 28; /* time to delay syncing metadata */ 293 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 294 "Time to delay syncing metadata (in seconds)"); 295 static int rushjob; /* number of slots to run ASAP */ 296 static int stat_rush_requests; /* number of times I/O speeded up */ 297 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 298 "Number of times I/O speeded up (rush requests)"); 299 300 #define VDBATCH_SIZE 8 301 struct vdbatch { 302 u_int index; 303 long freevnodes; 304 struct mtx lock; 305 struct vnode *tab[VDBATCH_SIZE]; 306 }; 307 DPCPU_DEFINE_STATIC(struct vdbatch, vd); 308 309 static void vdbatch_dequeue(struct vnode *vp); 310 311 /* 312 * When shutting down the syncer, run it at four times normal speed. 313 */ 314 #define SYNCER_SHUTDOWN_SPEEDUP 4 315 static int sync_vnode_count; 316 static int syncer_worklist_len; 317 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 318 syncer_state; 319 320 /* Target for maximum number of vnodes. */ 321 u_long desiredvnodes; 322 static u_long gapvnodes; /* gap between wanted and desired */ 323 static u_long vhiwat; /* enough extras after expansion */ 324 static u_long vlowat; /* minimal extras before expansion */ 325 static u_long vstir; /* nonzero to stir non-free vnodes */ 326 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 327 328 static u_long vnlru_read_freevnodes(void); 329 330 /* 331 * Note that no attempt is made to sanitize these parameters. 332 */ 333 static int 334 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS) 335 { 336 u_long val; 337 int error; 338 339 val = desiredvnodes; 340 error = sysctl_handle_long(oidp, &val, 0, req); 341 if (error != 0 || req->newptr == NULL) 342 return (error); 343 344 if (val == desiredvnodes) 345 return (0); 346 mtx_lock(&vnode_list_mtx); 347 desiredvnodes = val; 348 wantfreevnodes = desiredvnodes / 4; 349 vnlru_recalc(); 350 mtx_unlock(&vnode_list_mtx); 351 /* 352 * XXX There is no protection against multiple threads changing 353 * desiredvnodes at the same time. Locking above only helps vnlru and 354 * getnewvnode. 355 */ 356 vfs_hash_changesize(desiredvnodes); 357 cache_changesize(desiredvnodes); 358 return (0); 359 } 360 361 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 362 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes, 363 "LU", "Target for maximum number of vnodes"); 364 365 static int 366 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS) 367 { 368 u_long val; 369 int error; 370 371 val = wantfreevnodes; 372 error = sysctl_handle_long(oidp, &val, 0, req); 373 if (error != 0 || req->newptr == NULL) 374 return (error); 375 376 if (val == wantfreevnodes) 377 return (0); 378 mtx_lock(&vnode_list_mtx); 379 wantfreevnodes = val; 380 vnlru_recalc(); 381 mtx_unlock(&vnode_list_mtx); 382 return (0); 383 } 384 385 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes, 386 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes, 387 "LU", "Target for minimum number of \"free\" vnodes"); 388 389 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 390 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 391 static int vnlru_nowhere; 392 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 393 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 394 395 static int 396 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 397 { 398 struct vnode *vp; 399 struct nameidata nd; 400 char *buf; 401 unsigned long ndflags; 402 int error; 403 404 if (req->newptr == NULL) 405 return (EINVAL); 406 if (req->newlen >= PATH_MAX) 407 return (E2BIG); 408 409 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK); 410 error = SYSCTL_IN(req, buf, req->newlen); 411 if (error != 0) 412 goto out; 413 414 buf[req->newlen] = '\0'; 415 416 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME; 417 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); 418 if ((error = namei(&nd)) != 0) 419 goto out; 420 vp = nd.ni_vp; 421 422 if (VN_IS_DOOMED(vp)) { 423 /* 424 * This vnode is being recycled. Return != 0 to let the caller 425 * know that the sysctl had no effect. Return EAGAIN because a 426 * subsequent call will likely succeed (since namei will create 427 * a new vnode if necessary) 428 */ 429 error = EAGAIN; 430 goto putvnode; 431 } 432 433 counter_u64_add(recycles_count, 1); 434 vgone(vp); 435 putvnode: 436 NDFREE(&nd, 0); 437 out: 438 free(buf, M_TEMP); 439 return (error); 440 } 441 442 static int 443 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 444 { 445 struct thread *td = curthread; 446 struct vnode *vp; 447 struct file *fp; 448 int error; 449 int fd; 450 451 if (req->newptr == NULL) 452 return (EBADF); 453 454 error = sysctl_handle_int(oidp, &fd, 0, req); 455 if (error != 0) 456 return (error); 457 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 458 if (error != 0) 459 return (error); 460 vp = fp->f_vnode; 461 462 error = vn_lock(vp, LK_EXCLUSIVE); 463 if (error != 0) 464 goto drop; 465 466 counter_u64_add(recycles_count, 1); 467 vgone(vp); 468 VOP_UNLOCK(vp); 469 drop: 470 fdrop(fp, td); 471 return (error); 472 } 473 474 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 475 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 476 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 477 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 478 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 479 sysctl_ftry_reclaim_vnode, "I", 480 "Try to reclaim a vnode by its file descriptor"); 481 482 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 483 static int vnsz2log; 484 485 /* 486 * Support for the bufobj clean & dirty pctrie. 487 */ 488 static void * 489 buf_trie_alloc(struct pctrie *ptree) 490 { 491 492 return uma_zalloc(buf_trie_zone, M_NOWAIT); 493 } 494 495 static void 496 buf_trie_free(struct pctrie *ptree, void *node) 497 { 498 499 uma_zfree(buf_trie_zone, node); 500 } 501 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 502 503 /* 504 * Initialize the vnode management data structures. 505 * 506 * Reevaluate the following cap on the number of vnodes after the physical 507 * memory size exceeds 512GB. In the limit, as the physical memory size 508 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 509 */ 510 #ifndef MAXVNODES_MAX 511 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */ 512 #endif 513 514 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 515 516 static struct vnode * 517 vn_alloc_marker(struct mount *mp) 518 { 519 struct vnode *vp; 520 521 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 522 vp->v_type = VMARKER; 523 vp->v_mount = mp; 524 525 return (vp); 526 } 527 528 static void 529 vn_free_marker(struct vnode *vp) 530 { 531 532 MPASS(vp->v_type == VMARKER); 533 free(vp, M_VNODE_MARKER); 534 } 535 536 /* 537 * Initialize a vnode as it first enters the zone. 538 */ 539 static int 540 vnode_init(void *mem, int size, int flags) 541 { 542 struct vnode *vp; 543 544 vp = mem; 545 bzero(vp, size); 546 /* 547 * Setup locks. 548 */ 549 vp->v_vnlock = &vp->v_lock; 550 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 551 /* 552 * By default, don't allow shared locks unless filesystems opt-in. 553 */ 554 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 555 LK_NOSHARE | LK_IS_VNODE); 556 /* 557 * Initialize bufobj. 558 */ 559 bufobj_init(&vp->v_bufobj, vp); 560 /* 561 * Initialize namecache. 562 */ 563 LIST_INIT(&vp->v_cache_src); 564 TAILQ_INIT(&vp->v_cache_dst); 565 /* 566 * Initialize rangelocks. 567 */ 568 rangelock_init(&vp->v_rl); 569 570 vp->v_dbatchcpu = NOCPU; 571 572 mtx_lock(&vnode_list_mtx); 573 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist); 574 mtx_unlock(&vnode_list_mtx); 575 return (0); 576 } 577 578 /* 579 * Free a vnode when it is cleared from the zone. 580 */ 581 static void 582 vnode_fini(void *mem, int size) 583 { 584 struct vnode *vp; 585 struct bufobj *bo; 586 587 vp = mem; 588 vdbatch_dequeue(vp); 589 mtx_lock(&vnode_list_mtx); 590 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 591 mtx_unlock(&vnode_list_mtx); 592 rangelock_destroy(&vp->v_rl); 593 lockdestroy(vp->v_vnlock); 594 mtx_destroy(&vp->v_interlock); 595 bo = &vp->v_bufobj; 596 rw_destroy(BO_LOCKPTR(bo)); 597 } 598 599 /* 600 * Provide the size of NFS nclnode and NFS fh for calculation of the 601 * vnode memory consumption. The size is specified directly to 602 * eliminate dependency on NFS-private header. 603 * 604 * Other filesystems may use bigger or smaller (like UFS and ZFS) 605 * private inode data, but the NFS-based estimation is ample enough. 606 * Still, we care about differences in the size between 64- and 32-bit 607 * platforms. 608 * 609 * Namecache structure size is heuristically 610 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 611 */ 612 #ifdef _LP64 613 #define NFS_NCLNODE_SZ (528 + 64) 614 #define NC_SZ 148 615 #else 616 #define NFS_NCLNODE_SZ (360 + 32) 617 #define NC_SZ 92 618 #endif 619 620 static void 621 vntblinit(void *dummy __unused) 622 { 623 struct vdbatch *vd; 624 int cpu, physvnodes, virtvnodes; 625 u_int i; 626 627 /* 628 * Desiredvnodes is a function of the physical memory size and the 629 * kernel's heap size. Generally speaking, it scales with the 630 * physical memory size. The ratio of desiredvnodes to the physical 631 * memory size is 1:16 until desiredvnodes exceeds 98,304. 632 * Thereafter, the 633 * marginal ratio of desiredvnodes to the physical memory size is 634 * 1:64. However, desiredvnodes is limited by the kernel's heap 635 * size. The memory required by desiredvnodes vnodes and vm objects 636 * must not exceed 1/10th of the kernel's heap size. 637 */ 638 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 639 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 640 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 641 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 642 desiredvnodes = min(physvnodes, virtvnodes); 643 if (desiredvnodes > MAXVNODES_MAX) { 644 if (bootverbose) 645 printf("Reducing kern.maxvnodes %lu -> %lu\n", 646 desiredvnodes, MAXVNODES_MAX); 647 desiredvnodes = MAXVNODES_MAX; 648 } 649 wantfreevnodes = desiredvnodes / 4; 650 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 651 TAILQ_INIT(&vnode_list); 652 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF); 653 /* 654 * The lock is taken to appease WITNESS. 655 */ 656 mtx_lock(&vnode_list_mtx); 657 vnlru_recalc(); 658 mtx_unlock(&vnode_list_mtx); 659 vnode_list_free_marker = vn_alloc_marker(NULL); 660 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist); 661 vnode_list_reclaim_marker = vn_alloc_marker(NULL); 662 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist); 663 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 664 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 665 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 666 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 667 /* 668 * Preallocate enough nodes to support one-per buf so that 669 * we can not fail an insert. reassignbuf() callers can not 670 * tolerate the insertion failure. 671 */ 672 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 673 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 674 UMA_ZONE_NOFREE | UMA_ZONE_VM); 675 uma_prealloc(buf_trie_zone, nbuf); 676 677 vnodes_created = counter_u64_alloc(M_WAITOK); 678 recycles_count = counter_u64_alloc(M_WAITOK); 679 recycles_free_count = counter_u64_alloc(M_WAITOK); 680 deferred_inact = counter_u64_alloc(M_WAITOK); 681 682 /* 683 * Initialize the filesystem syncer. 684 */ 685 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 686 &syncer_mask); 687 syncer_maxdelay = syncer_mask + 1; 688 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 689 cv_init(&sync_wakeup, "syncer"); 690 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 691 vnsz2log++; 692 vnsz2log--; 693 694 CPU_FOREACH(cpu) { 695 vd = DPCPU_ID_PTR((cpu), vd); 696 bzero(vd, sizeof(*vd)); 697 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF); 698 } 699 } 700 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 701 702 /* 703 * Mark a mount point as busy. Used to synchronize access and to delay 704 * unmounting. Eventually, mountlist_mtx is not released on failure. 705 * 706 * vfs_busy() is a custom lock, it can block the caller. 707 * vfs_busy() only sleeps if the unmount is active on the mount point. 708 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 709 * vnode belonging to mp. 710 * 711 * Lookup uses vfs_busy() to traverse mount points. 712 * root fs var fs 713 * / vnode lock A / vnode lock (/var) D 714 * /var vnode lock B /log vnode lock(/var/log) E 715 * vfs_busy lock C vfs_busy lock F 716 * 717 * Within each file system, the lock order is C->A->B and F->D->E. 718 * 719 * When traversing across mounts, the system follows that lock order: 720 * 721 * C->A->B 722 * | 723 * +->F->D->E 724 * 725 * The lookup() process for namei("/var") illustrates the process: 726 * VOP_LOOKUP() obtains B while A is held 727 * vfs_busy() obtains a shared lock on F while A and B are held 728 * vput() releases lock on B 729 * vput() releases lock on A 730 * VFS_ROOT() obtains lock on D while shared lock on F is held 731 * vfs_unbusy() releases shared lock on F 732 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 733 * Attempt to lock A (instead of vp_crossmp) while D is held would 734 * violate the global order, causing deadlocks. 735 * 736 * dounmount() locks B while F is drained. 737 */ 738 int 739 vfs_busy(struct mount *mp, int flags) 740 { 741 742 MPASS((flags & ~MBF_MASK) == 0); 743 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 744 745 if (vfs_op_thread_enter(mp)) { 746 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 747 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0); 748 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0); 749 vfs_mp_count_add_pcpu(mp, ref, 1); 750 vfs_mp_count_add_pcpu(mp, lockref, 1); 751 vfs_op_thread_exit(mp); 752 if (flags & MBF_MNTLSTLOCK) 753 mtx_unlock(&mountlist_mtx); 754 return (0); 755 } 756 757 MNT_ILOCK(mp); 758 vfs_assert_mount_counters(mp); 759 MNT_REF(mp); 760 /* 761 * If mount point is currently being unmounted, sleep until the 762 * mount point fate is decided. If thread doing the unmounting fails, 763 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 764 * that this mount point has survived the unmount attempt and vfs_busy 765 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 766 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 767 * about to be really destroyed. vfs_busy needs to release its 768 * reference on the mount point in this case and return with ENOENT, 769 * telling the caller that mount mount it tried to busy is no longer 770 * valid. 771 */ 772 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 773 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 774 MNT_REL(mp); 775 MNT_IUNLOCK(mp); 776 CTR1(KTR_VFS, "%s: failed busying before sleeping", 777 __func__); 778 return (ENOENT); 779 } 780 if (flags & MBF_MNTLSTLOCK) 781 mtx_unlock(&mountlist_mtx); 782 mp->mnt_kern_flag |= MNTK_MWAIT; 783 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 784 if (flags & MBF_MNTLSTLOCK) 785 mtx_lock(&mountlist_mtx); 786 MNT_ILOCK(mp); 787 } 788 if (flags & MBF_MNTLSTLOCK) 789 mtx_unlock(&mountlist_mtx); 790 mp->mnt_lockref++; 791 MNT_IUNLOCK(mp); 792 return (0); 793 } 794 795 /* 796 * Free a busy filesystem. 797 */ 798 void 799 vfs_unbusy(struct mount *mp) 800 { 801 int c; 802 803 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 804 805 if (vfs_op_thread_enter(mp)) { 806 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 807 vfs_mp_count_sub_pcpu(mp, lockref, 1); 808 vfs_mp_count_sub_pcpu(mp, ref, 1); 809 vfs_op_thread_exit(mp); 810 return; 811 } 812 813 MNT_ILOCK(mp); 814 vfs_assert_mount_counters(mp); 815 MNT_REL(mp); 816 c = --mp->mnt_lockref; 817 if (mp->mnt_vfs_ops == 0) { 818 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 819 MNT_IUNLOCK(mp); 820 return; 821 } 822 if (c < 0) 823 vfs_dump_mount_counters(mp); 824 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 825 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 826 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 827 mp->mnt_kern_flag &= ~MNTK_DRAINING; 828 wakeup(&mp->mnt_lockref); 829 } 830 MNT_IUNLOCK(mp); 831 } 832 833 /* 834 * Lookup a mount point by filesystem identifier. 835 */ 836 struct mount * 837 vfs_getvfs(fsid_t *fsid) 838 { 839 struct mount *mp; 840 841 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 842 mtx_lock(&mountlist_mtx); 843 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 844 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 845 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 846 vfs_ref(mp); 847 mtx_unlock(&mountlist_mtx); 848 return (mp); 849 } 850 } 851 mtx_unlock(&mountlist_mtx); 852 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 853 return ((struct mount *) 0); 854 } 855 856 /* 857 * Lookup a mount point by filesystem identifier, busying it before 858 * returning. 859 * 860 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 861 * cache for popular filesystem identifiers. The cache is lockess, using 862 * the fact that struct mount's are never freed. In worst case we may 863 * get pointer to unmounted or even different filesystem, so we have to 864 * check what we got, and go slow way if so. 865 */ 866 struct mount * 867 vfs_busyfs(fsid_t *fsid) 868 { 869 #define FSID_CACHE_SIZE 256 870 typedef struct mount * volatile vmp_t; 871 static vmp_t cache[FSID_CACHE_SIZE]; 872 struct mount *mp; 873 int error; 874 uint32_t hash; 875 876 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 877 hash = fsid->val[0] ^ fsid->val[1]; 878 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 879 mp = cache[hash]; 880 if (mp == NULL || 881 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 882 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 883 goto slow; 884 if (vfs_busy(mp, 0) != 0) { 885 cache[hash] = NULL; 886 goto slow; 887 } 888 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 889 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 890 return (mp); 891 else 892 vfs_unbusy(mp); 893 894 slow: 895 mtx_lock(&mountlist_mtx); 896 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 897 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 898 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 899 error = vfs_busy(mp, MBF_MNTLSTLOCK); 900 if (error) { 901 cache[hash] = NULL; 902 mtx_unlock(&mountlist_mtx); 903 return (NULL); 904 } 905 cache[hash] = mp; 906 return (mp); 907 } 908 } 909 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 910 mtx_unlock(&mountlist_mtx); 911 return ((struct mount *) 0); 912 } 913 914 /* 915 * Check if a user can access privileged mount options. 916 */ 917 int 918 vfs_suser(struct mount *mp, struct thread *td) 919 { 920 int error; 921 922 if (jailed(td->td_ucred)) { 923 /* 924 * If the jail of the calling thread lacks permission for 925 * this type of file system, deny immediately. 926 */ 927 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 928 return (EPERM); 929 930 /* 931 * If the file system was mounted outside the jail of the 932 * calling thread, deny immediately. 933 */ 934 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 935 return (EPERM); 936 } 937 938 /* 939 * If file system supports delegated administration, we don't check 940 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 941 * by the file system itself. 942 * If this is not the user that did original mount, we check for 943 * the PRIV_VFS_MOUNT_OWNER privilege. 944 */ 945 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 946 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 947 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 948 return (error); 949 } 950 return (0); 951 } 952 953 /* 954 * Get a new unique fsid. Try to make its val[0] unique, since this value 955 * will be used to create fake device numbers for stat(). Also try (but 956 * not so hard) make its val[0] unique mod 2^16, since some emulators only 957 * support 16-bit device numbers. We end up with unique val[0]'s for the 958 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 959 * 960 * Keep in mind that several mounts may be running in parallel. Starting 961 * the search one past where the previous search terminated is both a 962 * micro-optimization and a defense against returning the same fsid to 963 * different mounts. 964 */ 965 void 966 vfs_getnewfsid(struct mount *mp) 967 { 968 static uint16_t mntid_base; 969 struct mount *nmp; 970 fsid_t tfsid; 971 int mtype; 972 973 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 974 mtx_lock(&mntid_mtx); 975 mtype = mp->mnt_vfc->vfc_typenum; 976 tfsid.val[1] = mtype; 977 mtype = (mtype & 0xFF) << 24; 978 for (;;) { 979 tfsid.val[0] = makedev(255, 980 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 981 mntid_base++; 982 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 983 break; 984 vfs_rel(nmp); 985 } 986 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 987 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 988 mtx_unlock(&mntid_mtx); 989 } 990 991 /* 992 * Knob to control the precision of file timestamps: 993 * 994 * 0 = seconds only; nanoseconds zeroed. 995 * 1 = seconds and nanoseconds, accurate within 1/HZ. 996 * 2 = seconds and nanoseconds, truncated to microseconds. 997 * >=3 = seconds and nanoseconds, maximum precision. 998 */ 999 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 1000 1001 static int timestamp_precision = TSP_USEC; 1002 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 1003 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 1004 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 1005 "3+: sec + ns (max. precision))"); 1006 1007 /* 1008 * Get a current timestamp. 1009 */ 1010 void 1011 vfs_timestamp(struct timespec *tsp) 1012 { 1013 struct timeval tv; 1014 1015 switch (timestamp_precision) { 1016 case TSP_SEC: 1017 tsp->tv_sec = time_second; 1018 tsp->tv_nsec = 0; 1019 break; 1020 case TSP_HZ: 1021 getnanotime(tsp); 1022 break; 1023 case TSP_USEC: 1024 microtime(&tv); 1025 TIMEVAL_TO_TIMESPEC(&tv, tsp); 1026 break; 1027 case TSP_NSEC: 1028 default: 1029 nanotime(tsp); 1030 break; 1031 } 1032 } 1033 1034 /* 1035 * Set vnode attributes to VNOVAL 1036 */ 1037 void 1038 vattr_null(struct vattr *vap) 1039 { 1040 1041 vap->va_type = VNON; 1042 vap->va_size = VNOVAL; 1043 vap->va_bytes = VNOVAL; 1044 vap->va_mode = VNOVAL; 1045 vap->va_nlink = VNOVAL; 1046 vap->va_uid = VNOVAL; 1047 vap->va_gid = VNOVAL; 1048 vap->va_fsid = VNOVAL; 1049 vap->va_fileid = VNOVAL; 1050 vap->va_blocksize = VNOVAL; 1051 vap->va_rdev = VNOVAL; 1052 vap->va_atime.tv_sec = VNOVAL; 1053 vap->va_atime.tv_nsec = VNOVAL; 1054 vap->va_mtime.tv_sec = VNOVAL; 1055 vap->va_mtime.tv_nsec = VNOVAL; 1056 vap->va_ctime.tv_sec = VNOVAL; 1057 vap->va_ctime.tv_nsec = VNOVAL; 1058 vap->va_birthtime.tv_sec = VNOVAL; 1059 vap->va_birthtime.tv_nsec = VNOVAL; 1060 vap->va_flags = VNOVAL; 1061 vap->va_gen = VNOVAL; 1062 vap->va_vaflags = 0; 1063 } 1064 1065 /* 1066 * Try to reduce the total number of vnodes. 1067 * 1068 * This routine (and its user) are buggy in at least the following ways: 1069 * - all parameters were picked years ago when RAM sizes were significantly 1070 * smaller 1071 * - it can pick vnodes based on pages used by the vm object, but filesystems 1072 * like ZFS don't use it making the pick broken 1073 * - since ZFS has its own aging policy it gets partially combated by this one 1074 * - a dedicated method should be provided for filesystems to let them decide 1075 * whether the vnode should be recycled 1076 * 1077 * This routine is called when we have too many vnodes. It attempts 1078 * to free <count> vnodes and will potentially free vnodes that still 1079 * have VM backing store (VM backing store is typically the cause 1080 * of a vnode blowout so we want to do this). Therefore, this operation 1081 * is not considered cheap. 1082 * 1083 * A number of conditions may prevent a vnode from being reclaimed. 1084 * the buffer cache may have references on the vnode, a directory 1085 * vnode may still have references due to the namei cache representing 1086 * underlying files, or the vnode may be in active use. It is not 1087 * desirable to reuse such vnodes. These conditions may cause the 1088 * number of vnodes to reach some minimum value regardless of what 1089 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 1090 * 1091 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 1092 * entries if this argument is strue 1093 * @param trigger Only reclaim vnodes with fewer than this many resident 1094 * pages. 1095 * @param target How many vnodes to reclaim. 1096 * @return The number of vnodes that were reclaimed. 1097 */ 1098 static int 1099 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target) 1100 { 1101 struct vnode *vp, *mvp; 1102 struct mount *mp; 1103 u_long done; 1104 bool retried; 1105 1106 mtx_assert(&vnode_list_mtx, MA_OWNED); 1107 1108 retried = false; 1109 done = 0; 1110 1111 mvp = vnode_list_reclaim_marker; 1112 restart: 1113 vp = mvp; 1114 while (done < target) { 1115 vp = TAILQ_NEXT(vp, v_vnodelist); 1116 if (__predict_false(vp == NULL)) 1117 break; 1118 1119 if (__predict_false(vp->v_type == VMARKER)) 1120 continue; 1121 1122 /* 1123 * If it's been deconstructed already, it's still 1124 * referenced, or it exceeds the trigger, skip it. 1125 * Also skip free vnodes. We are trying to make space 1126 * to expand the free list, not reduce it. 1127 */ 1128 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1129 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src))) 1130 goto next_iter; 1131 1132 if (vp->v_type == VBAD || vp->v_type == VNON) 1133 goto next_iter; 1134 1135 if (!VI_TRYLOCK(vp)) 1136 goto next_iter; 1137 1138 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1139 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1140 vp->v_type == VBAD || vp->v_type == VNON || 1141 (vp->v_object != NULL && 1142 vp->v_object->resident_page_count > trigger)) { 1143 VI_UNLOCK(vp); 1144 goto next_iter; 1145 } 1146 vholdl(vp); 1147 VI_UNLOCK(vp); 1148 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1149 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1150 mtx_unlock(&vnode_list_mtx); 1151 1152 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1153 vdrop(vp); 1154 goto next_iter_unlocked; 1155 } 1156 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { 1157 vdrop(vp); 1158 vn_finished_write(mp); 1159 goto next_iter_unlocked; 1160 } 1161 1162 VI_LOCK(vp); 1163 if (vp->v_usecount > 0 || 1164 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1165 (vp->v_object != NULL && 1166 vp->v_object->resident_page_count > trigger)) { 1167 VOP_UNLOCK(vp); 1168 vdropl(vp); 1169 vn_finished_write(mp); 1170 goto next_iter_unlocked; 1171 } 1172 counter_u64_add(recycles_count, 1); 1173 vgonel(vp); 1174 VOP_UNLOCK(vp); 1175 vdropl(vp); 1176 vn_finished_write(mp); 1177 done++; 1178 next_iter_unlocked: 1179 if (should_yield()) 1180 kern_yield(PRI_USER); 1181 mtx_lock(&vnode_list_mtx); 1182 goto restart; 1183 next_iter: 1184 MPASS(vp->v_type != VMARKER); 1185 if (!should_yield()) 1186 continue; 1187 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1188 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1189 mtx_unlock(&vnode_list_mtx); 1190 kern_yield(PRI_USER); 1191 mtx_lock(&vnode_list_mtx); 1192 goto restart; 1193 } 1194 if (done == 0 && !retried) { 1195 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1196 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1197 retried = true; 1198 goto restart; 1199 } 1200 return (done); 1201 } 1202 1203 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1204 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1205 0, 1206 "limit on vnode free requests per call to the vnlru_free routine"); 1207 1208 /* 1209 * Attempt to reduce the free list by the requested amount. 1210 */ 1211 static int 1212 vnlru_free_locked(int count, struct vfsops *mnt_op) 1213 { 1214 struct vnode *vp, *mvp; 1215 struct mount *mp; 1216 int ocount; 1217 1218 mtx_assert(&vnode_list_mtx, MA_OWNED); 1219 if (count > max_vnlru_free) 1220 count = max_vnlru_free; 1221 ocount = count; 1222 mvp = vnode_list_free_marker; 1223 restart: 1224 vp = mvp; 1225 while (count > 0) { 1226 vp = TAILQ_NEXT(vp, v_vnodelist); 1227 if (__predict_false(vp == NULL)) { 1228 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1229 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist); 1230 break; 1231 } 1232 if (__predict_false(vp->v_type == VMARKER)) 1233 continue; 1234 1235 /* 1236 * Don't recycle if our vnode is from different type 1237 * of mount point. Note that mp is type-safe, the 1238 * check does not reach unmapped address even if 1239 * vnode is reclaimed. 1240 * Don't recycle if we can't get the interlock without 1241 * blocking. 1242 */ 1243 if (vp->v_holdcnt > 0 || (mnt_op != NULL && (mp = vp->v_mount) != NULL && 1244 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1245 continue; 1246 } 1247 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1248 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1249 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1250 VI_UNLOCK(vp); 1251 continue; 1252 } 1253 vholdl(vp); 1254 count--; 1255 mtx_unlock(&vnode_list_mtx); 1256 VI_UNLOCK(vp); 1257 vtryrecycle(vp); 1258 vdrop(vp); 1259 mtx_lock(&vnode_list_mtx); 1260 goto restart; 1261 } 1262 return (ocount - count); 1263 } 1264 1265 void 1266 vnlru_free(int count, struct vfsops *mnt_op) 1267 { 1268 1269 mtx_lock(&vnode_list_mtx); 1270 vnlru_free_locked(count, mnt_op); 1271 mtx_unlock(&vnode_list_mtx); 1272 } 1273 1274 static void 1275 vnlru_recalc(void) 1276 { 1277 1278 mtx_assert(&vnode_list_mtx, MA_OWNED); 1279 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1280 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1281 vlowat = vhiwat / 2; 1282 } 1283 1284 /* 1285 * Attempt to recycle vnodes in a context that is always safe to block. 1286 * Calling vlrurecycle() from the bowels of filesystem code has some 1287 * interesting deadlock problems. 1288 */ 1289 static struct proc *vnlruproc; 1290 static int vnlruproc_sig; 1291 1292 /* 1293 * The main freevnodes counter is only updated when threads requeue their vnode 1294 * batches. CPUs are conditionally walked to compute a more accurate total. 1295 * 1296 * Limit how much of a slop are we willing to tolerate. Note: the actual value 1297 * at any given moment can still exceed slop, but it should not be by significant 1298 * margin in practice. 1299 */ 1300 #define VNLRU_FREEVNODES_SLOP 128 1301 1302 static u_long 1303 vnlru_read_freevnodes(void) 1304 { 1305 struct vdbatch *vd; 1306 long slop; 1307 int cpu; 1308 1309 mtx_assert(&vnode_list_mtx, MA_OWNED); 1310 if (freevnodes > freevnodes_old) 1311 slop = freevnodes - freevnodes_old; 1312 else 1313 slop = freevnodes_old - freevnodes; 1314 if (slop < VNLRU_FREEVNODES_SLOP) 1315 return (freevnodes >= 0 ? freevnodes : 0); 1316 freevnodes_old = freevnodes; 1317 CPU_FOREACH(cpu) { 1318 vd = DPCPU_ID_PTR((cpu), vd); 1319 freevnodes_old += vd->freevnodes; 1320 } 1321 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1322 } 1323 1324 static bool 1325 vnlru_under(u_long rnumvnodes, u_long limit) 1326 { 1327 u_long rfreevnodes, space; 1328 1329 if (__predict_false(rnumvnodes > desiredvnodes)) 1330 return (true); 1331 1332 space = desiredvnodes - rnumvnodes; 1333 if (space < limit) { 1334 rfreevnodes = vnlru_read_freevnodes(); 1335 if (rfreevnodes > wantfreevnodes) 1336 space += rfreevnodes - wantfreevnodes; 1337 } 1338 return (space < limit); 1339 } 1340 1341 static bool 1342 vnlru_under_unlocked(u_long rnumvnodes, u_long limit) 1343 { 1344 long rfreevnodes, space; 1345 1346 if (__predict_false(rnumvnodes > desiredvnodes)) 1347 return (true); 1348 1349 space = desiredvnodes - rnumvnodes; 1350 if (space < limit) { 1351 rfreevnodes = atomic_load_long(&freevnodes); 1352 if (rfreevnodes > wantfreevnodes) 1353 space += rfreevnodes - wantfreevnodes; 1354 } 1355 return (space < limit); 1356 } 1357 1358 static void 1359 vnlru_kick(void) 1360 { 1361 1362 mtx_assert(&vnode_list_mtx, MA_OWNED); 1363 if (vnlruproc_sig == 0) { 1364 vnlruproc_sig = 1; 1365 wakeup(vnlruproc); 1366 } 1367 } 1368 1369 static void 1370 vnlru_proc(void) 1371 { 1372 u_long rnumvnodes, rfreevnodes, target; 1373 unsigned long onumvnodes; 1374 int done, force, trigger, usevnodes; 1375 bool reclaim_nc_src, want_reread; 1376 1377 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1378 SHUTDOWN_PRI_FIRST); 1379 1380 force = 0; 1381 want_reread = false; 1382 for (;;) { 1383 kproc_suspend_check(vnlruproc); 1384 mtx_lock(&vnode_list_mtx); 1385 rnumvnodes = atomic_load_long(&numvnodes); 1386 1387 if (want_reread) { 1388 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1389 want_reread = false; 1390 } 1391 1392 /* 1393 * If numvnodes is too large (due to desiredvnodes being 1394 * adjusted using its sysctl, or emergency growth), first 1395 * try to reduce it by discarding from the free list. 1396 */ 1397 if (rnumvnodes > desiredvnodes) { 1398 vnlru_free_locked(rnumvnodes - desiredvnodes, NULL); 1399 rnumvnodes = atomic_load_long(&numvnodes); 1400 } 1401 /* 1402 * Sleep if the vnode cache is in a good state. This is 1403 * when it is not over-full and has space for about a 4% 1404 * or 9% expansion (by growing its size or inexcessively 1405 * reducing its free list). Otherwise, try to reclaim 1406 * space for a 10% expansion. 1407 */ 1408 if (vstir && force == 0) { 1409 force = 1; 1410 vstir = 0; 1411 } 1412 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1413 vnlruproc_sig = 0; 1414 wakeup(&vnlruproc_sig); 1415 msleep(vnlruproc, &vnode_list_mtx, 1416 PVFS|PDROP, "vlruwt", hz); 1417 continue; 1418 } 1419 rfreevnodes = vnlru_read_freevnodes(); 1420 1421 onumvnodes = rnumvnodes; 1422 /* 1423 * Calculate parameters for recycling. These are the same 1424 * throughout the loop to give some semblance of fairness. 1425 * The trigger point is to avoid recycling vnodes with lots 1426 * of resident pages. We aren't trying to free memory; we 1427 * are trying to recycle or at least free vnodes. 1428 */ 1429 if (rnumvnodes <= desiredvnodes) 1430 usevnodes = rnumvnodes - rfreevnodes; 1431 else 1432 usevnodes = rnumvnodes; 1433 if (usevnodes <= 0) 1434 usevnodes = 1; 1435 /* 1436 * The trigger value is is chosen to give a conservatively 1437 * large value to ensure that it alone doesn't prevent 1438 * making progress. The value can easily be so large that 1439 * it is effectively infinite in some congested and 1440 * misconfigured cases, and this is necessary. Normally 1441 * it is about 8 to 100 (pages), which is quite large. 1442 */ 1443 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1444 if (force < 2) 1445 trigger = vsmalltrigger; 1446 reclaim_nc_src = force >= 3; 1447 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1448 target = target / 10 + 1; 1449 done = vlrureclaim(reclaim_nc_src, trigger, target); 1450 mtx_unlock(&vnode_list_mtx); 1451 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1452 uma_reclaim(UMA_RECLAIM_DRAIN); 1453 if (done == 0) { 1454 if (force == 0 || force == 1) { 1455 force = 2; 1456 continue; 1457 } 1458 if (force == 2) { 1459 force = 3; 1460 continue; 1461 } 1462 want_reread = true; 1463 force = 0; 1464 vnlru_nowhere++; 1465 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1466 } else { 1467 want_reread = true; 1468 kern_yield(PRI_USER); 1469 } 1470 } 1471 } 1472 1473 static struct kproc_desc vnlru_kp = { 1474 "vnlru", 1475 vnlru_proc, 1476 &vnlruproc 1477 }; 1478 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1479 &vnlru_kp); 1480 1481 /* 1482 * Routines having to do with the management of the vnode table. 1483 */ 1484 1485 /* 1486 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1487 * before we actually vgone(). This function must be called with the vnode 1488 * held to prevent the vnode from being returned to the free list midway 1489 * through vgone(). 1490 */ 1491 static int 1492 vtryrecycle(struct vnode *vp) 1493 { 1494 struct mount *vnmp; 1495 1496 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1497 VNASSERT(vp->v_holdcnt, vp, 1498 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1499 /* 1500 * This vnode may found and locked via some other list, if so we 1501 * can't recycle it yet. 1502 */ 1503 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1504 CTR2(KTR_VFS, 1505 "%s: impossible to recycle, vp %p lock is already held", 1506 __func__, vp); 1507 return (EWOULDBLOCK); 1508 } 1509 /* 1510 * Don't recycle if its filesystem is being suspended. 1511 */ 1512 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1513 VOP_UNLOCK(vp); 1514 CTR2(KTR_VFS, 1515 "%s: impossible to recycle, cannot start the write for %p", 1516 __func__, vp); 1517 return (EBUSY); 1518 } 1519 /* 1520 * If we got this far, we need to acquire the interlock and see if 1521 * anyone picked up this vnode from another list. If not, we will 1522 * mark it with DOOMED via vgonel() so that anyone who does find it 1523 * will skip over it. 1524 */ 1525 VI_LOCK(vp); 1526 if (vp->v_usecount) { 1527 VOP_UNLOCK(vp); 1528 VI_UNLOCK(vp); 1529 vn_finished_write(vnmp); 1530 CTR2(KTR_VFS, 1531 "%s: impossible to recycle, %p is already referenced", 1532 __func__, vp); 1533 return (EBUSY); 1534 } 1535 if (!VN_IS_DOOMED(vp)) { 1536 counter_u64_add(recycles_free_count, 1); 1537 vgonel(vp); 1538 } 1539 VOP_UNLOCK(vp); 1540 VI_UNLOCK(vp); 1541 vn_finished_write(vnmp); 1542 return (0); 1543 } 1544 1545 /* 1546 * Allocate a new vnode. 1547 * 1548 * The operation never returns an error. Returning an error was disabled 1549 * in r145385 (dated 2005) with the following comment: 1550 * 1551 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1552 * 1553 * Given the age of this commit (almost 15 years at the time of writing this 1554 * comment) restoring the ability to fail requires a significant audit of 1555 * all codepaths. 1556 * 1557 * The routine can try to free a vnode or stall for up to 1 second waiting for 1558 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1559 */ 1560 static u_long vn_alloc_cyclecount; 1561 1562 static struct vnode * __noinline 1563 vn_alloc_hard(struct mount *mp) 1564 { 1565 u_long rnumvnodes, rfreevnodes; 1566 1567 mtx_lock(&vnode_list_mtx); 1568 rnumvnodes = atomic_load_long(&numvnodes); 1569 if (rnumvnodes + 1 < desiredvnodes) { 1570 vn_alloc_cyclecount = 0; 1571 goto alloc; 1572 } 1573 rfreevnodes = vnlru_read_freevnodes(); 1574 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1575 vn_alloc_cyclecount = 0; 1576 vstir = 1; 1577 } 1578 /* 1579 * Grow the vnode cache if it will not be above its target max 1580 * after growing. Otherwise, if the free list is nonempty, try 1581 * to reclaim 1 item from it before growing the cache (possibly 1582 * above its target max if the reclamation failed or is delayed). 1583 * Otherwise, wait for some space. In all cases, schedule 1584 * vnlru_proc() if we are getting short of space. The watermarks 1585 * should be chosen so that we never wait or even reclaim from 1586 * the free list to below its target minimum. 1587 */ 1588 if (vnlru_free_locked(1, NULL) > 0) 1589 goto alloc; 1590 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1591 /* 1592 * Wait for space for a new vnode. 1593 */ 1594 vnlru_kick(); 1595 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1596 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1597 vnlru_read_freevnodes() > 1) 1598 vnlru_free_locked(1, NULL); 1599 } 1600 alloc: 1601 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1602 if (vnlru_under(rnumvnodes, vlowat)) 1603 vnlru_kick(); 1604 mtx_unlock(&vnode_list_mtx); 1605 return (uma_zalloc(vnode_zone, M_WAITOK)); 1606 } 1607 1608 static struct vnode * 1609 vn_alloc(struct mount *mp) 1610 { 1611 u_long rnumvnodes; 1612 1613 if (__predict_false(vn_alloc_cyclecount != 0)) 1614 return (vn_alloc_hard(mp)); 1615 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1616 if (__predict_false(vnlru_under_unlocked(rnumvnodes, vlowat))) { 1617 atomic_subtract_long(&numvnodes, 1); 1618 return (vn_alloc_hard(mp)); 1619 } 1620 1621 return (uma_zalloc(vnode_zone, M_WAITOK)); 1622 } 1623 1624 static void 1625 vn_free(struct vnode *vp) 1626 { 1627 1628 atomic_subtract_long(&numvnodes, 1); 1629 uma_zfree(vnode_zone, vp); 1630 } 1631 1632 /* 1633 * Return the next vnode from the free list. 1634 */ 1635 int 1636 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1637 struct vnode **vpp) 1638 { 1639 struct vnode *vp; 1640 struct thread *td; 1641 struct lock_object *lo; 1642 1643 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1644 1645 KASSERT(vops->registered, 1646 ("%s: not registered vector op %p\n", __func__, vops)); 1647 1648 td = curthread; 1649 if (td->td_vp_reserved != NULL) { 1650 vp = td->td_vp_reserved; 1651 td->td_vp_reserved = NULL; 1652 } else { 1653 vp = vn_alloc(mp); 1654 } 1655 counter_u64_add(vnodes_created, 1); 1656 /* 1657 * Locks are given the generic name "vnode" when created. 1658 * Follow the historic practice of using the filesystem 1659 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1660 * 1661 * Locks live in a witness group keyed on their name. Thus, 1662 * when a lock is renamed, it must also move from the witness 1663 * group of its old name to the witness group of its new name. 1664 * 1665 * The change only needs to be made when the vnode moves 1666 * from one filesystem type to another. We ensure that each 1667 * filesystem use a single static name pointer for its tag so 1668 * that we can compare pointers rather than doing a strcmp(). 1669 */ 1670 lo = &vp->v_vnlock->lock_object; 1671 #ifdef WITNESS 1672 if (lo->lo_name != tag) { 1673 #endif 1674 lo->lo_name = tag; 1675 #ifdef WITNESS 1676 WITNESS_DESTROY(lo); 1677 WITNESS_INIT(lo, tag); 1678 } 1679 #endif 1680 /* 1681 * By default, don't allow shared locks unless filesystems opt-in. 1682 */ 1683 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1684 /* 1685 * Finalize various vnode identity bits. 1686 */ 1687 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1688 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1689 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1690 vp->v_type = VNON; 1691 vp->v_op = vops; 1692 v_init_counters(vp); 1693 vp->v_bufobj.bo_ops = &buf_ops_bio; 1694 #ifdef DIAGNOSTIC 1695 if (mp == NULL && vops != &dead_vnodeops) 1696 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1697 #endif 1698 #ifdef MAC 1699 mac_vnode_init(vp); 1700 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1701 mac_vnode_associate_singlelabel(mp, vp); 1702 #endif 1703 if (mp != NULL) { 1704 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1705 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1706 vp->v_vflag |= VV_NOKNOTE; 1707 } 1708 1709 /* 1710 * For the filesystems which do not use vfs_hash_insert(), 1711 * still initialize v_hash to have vfs_hash_index() useful. 1712 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1713 * its own hashing. 1714 */ 1715 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1716 1717 *vpp = vp; 1718 return (0); 1719 } 1720 1721 void 1722 getnewvnode_reserve(void) 1723 { 1724 struct thread *td; 1725 1726 td = curthread; 1727 MPASS(td->td_vp_reserved == NULL); 1728 td->td_vp_reserved = vn_alloc(NULL); 1729 } 1730 1731 void 1732 getnewvnode_drop_reserve(void) 1733 { 1734 struct thread *td; 1735 1736 td = curthread; 1737 if (td->td_vp_reserved != NULL) { 1738 vn_free(td->td_vp_reserved); 1739 td->td_vp_reserved = NULL; 1740 } 1741 } 1742 1743 static void 1744 freevnode(struct vnode *vp) 1745 { 1746 struct bufobj *bo; 1747 1748 /* 1749 * The vnode has been marked for destruction, so free it. 1750 * 1751 * The vnode will be returned to the zone where it will 1752 * normally remain until it is needed for another vnode. We 1753 * need to cleanup (or verify that the cleanup has already 1754 * been done) any residual data left from its current use 1755 * so as not to contaminate the freshly allocated vnode. 1756 */ 1757 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1758 bo = &vp->v_bufobj; 1759 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1760 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 1761 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1762 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1763 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1764 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1765 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1766 ("clean blk trie not empty")); 1767 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1768 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1769 ("dirty blk trie not empty")); 1770 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1771 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1772 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1773 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1774 ("Dangling rangelock waiters")); 1775 VI_UNLOCK(vp); 1776 #ifdef MAC 1777 mac_vnode_destroy(vp); 1778 #endif 1779 if (vp->v_pollinfo != NULL) { 1780 destroy_vpollinfo(vp->v_pollinfo); 1781 vp->v_pollinfo = NULL; 1782 } 1783 #ifdef INVARIANTS 1784 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1785 vp->v_op = NULL; 1786 #endif 1787 vp->v_mountedhere = NULL; 1788 vp->v_unpcb = NULL; 1789 vp->v_rdev = NULL; 1790 vp->v_fifoinfo = NULL; 1791 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1792 vp->v_irflag = 0; 1793 vp->v_iflag = 0; 1794 vp->v_vflag = 0; 1795 bo->bo_flag = 0; 1796 vn_free(vp); 1797 } 1798 1799 /* 1800 * Delete from old mount point vnode list, if on one. 1801 */ 1802 static void 1803 delmntque(struct vnode *vp) 1804 { 1805 struct mount *mp; 1806 1807 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 1808 1809 mp = vp->v_mount; 1810 if (mp == NULL) 1811 return; 1812 MNT_ILOCK(mp); 1813 VI_LOCK(vp); 1814 vp->v_mount = NULL; 1815 VI_UNLOCK(vp); 1816 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1817 ("bad mount point vnode list size")); 1818 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1819 mp->mnt_nvnodelistsize--; 1820 MNT_REL(mp); 1821 MNT_IUNLOCK(mp); 1822 } 1823 1824 static void 1825 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1826 { 1827 1828 vp->v_data = NULL; 1829 vp->v_op = &dead_vnodeops; 1830 vgone(vp); 1831 vput(vp); 1832 } 1833 1834 /* 1835 * Insert into list of vnodes for the new mount point, if available. 1836 */ 1837 int 1838 insmntque1(struct vnode *vp, struct mount *mp, 1839 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1840 { 1841 1842 KASSERT(vp->v_mount == NULL, 1843 ("insmntque: vnode already on per mount vnode list")); 1844 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1845 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1846 1847 /* 1848 * We acquire the vnode interlock early to ensure that the 1849 * vnode cannot be recycled by another process releasing a 1850 * holdcnt on it before we get it on both the vnode list 1851 * and the active vnode list. The mount mutex protects only 1852 * manipulation of the vnode list and the vnode freelist 1853 * mutex protects only manipulation of the active vnode list. 1854 * Hence the need to hold the vnode interlock throughout. 1855 */ 1856 MNT_ILOCK(mp); 1857 VI_LOCK(vp); 1858 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1859 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1860 mp->mnt_nvnodelistsize == 0)) && 1861 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1862 VI_UNLOCK(vp); 1863 MNT_IUNLOCK(mp); 1864 if (dtr != NULL) 1865 dtr(vp, dtr_arg); 1866 return (EBUSY); 1867 } 1868 vp->v_mount = mp; 1869 MNT_REF(mp); 1870 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1871 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1872 ("neg mount point vnode list size")); 1873 mp->mnt_nvnodelistsize++; 1874 VI_UNLOCK(vp); 1875 MNT_IUNLOCK(mp); 1876 return (0); 1877 } 1878 1879 int 1880 insmntque(struct vnode *vp, struct mount *mp) 1881 { 1882 1883 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1884 } 1885 1886 /* 1887 * Flush out and invalidate all buffers associated with a bufobj 1888 * Called with the underlying object locked. 1889 */ 1890 int 1891 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1892 { 1893 int error; 1894 1895 BO_LOCK(bo); 1896 if (flags & V_SAVE) { 1897 error = bufobj_wwait(bo, slpflag, slptimeo); 1898 if (error) { 1899 BO_UNLOCK(bo); 1900 return (error); 1901 } 1902 if (bo->bo_dirty.bv_cnt > 0) { 1903 BO_UNLOCK(bo); 1904 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1905 return (error); 1906 /* 1907 * XXX We could save a lock/unlock if this was only 1908 * enabled under INVARIANTS 1909 */ 1910 BO_LOCK(bo); 1911 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1912 panic("vinvalbuf: dirty bufs"); 1913 } 1914 } 1915 /* 1916 * If you alter this loop please notice that interlock is dropped and 1917 * reacquired in flushbuflist. Special care is needed to ensure that 1918 * no race conditions occur from this. 1919 */ 1920 do { 1921 error = flushbuflist(&bo->bo_clean, 1922 flags, bo, slpflag, slptimeo); 1923 if (error == 0 && !(flags & V_CLEANONLY)) 1924 error = flushbuflist(&bo->bo_dirty, 1925 flags, bo, slpflag, slptimeo); 1926 if (error != 0 && error != EAGAIN) { 1927 BO_UNLOCK(bo); 1928 return (error); 1929 } 1930 } while (error != 0); 1931 1932 /* 1933 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1934 * have write I/O in-progress but if there is a VM object then the 1935 * VM object can also have read-I/O in-progress. 1936 */ 1937 do { 1938 bufobj_wwait(bo, 0, 0); 1939 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1940 BO_UNLOCK(bo); 1941 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1942 BO_LOCK(bo); 1943 } 1944 } while (bo->bo_numoutput > 0); 1945 BO_UNLOCK(bo); 1946 1947 /* 1948 * Destroy the copy in the VM cache, too. 1949 */ 1950 if (bo->bo_object != NULL && 1951 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1952 VM_OBJECT_WLOCK(bo->bo_object); 1953 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1954 OBJPR_CLEANONLY : 0); 1955 VM_OBJECT_WUNLOCK(bo->bo_object); 1956 } 1957 1958 #ifdef INVARIANTS 1959 BO_LOCK(bo); 1960 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1961 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1962 bo->bo_clean.bv_cnt > 0)) 1963 panic("vinvalbuf: flush failed"); 1964 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1965 bo->bo_dirty.bv_cnt > 0) 1966 panic("vinvalbuf: flush dirty failed"); 1967 BO_UNLOCK(bo); 1968 #endif 1969 return (0); 1970 } 1971 1972 /* 1973 * Flush out and invalidate all buffers associated with a vnode. 1974 * Called with the underlying object locked. 1975 */ 1976 int 1977 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1978 { 1979 1980 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1981 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1982 if (vp->v_object != NULL && vp->v_object->handle != vp) 1983 return (0); 1984 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1985 } 1986 1987 /* 1988 * Flush out buffers on the specified list. 1989 * 1990 */ 1991 static int 1992 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1993 int slptimeo) 1994 { 1995 struct buf *bp, *nbp; 1996 int retval, error; 1997 daddr_t lblkno; 1998 b_xflags_t xflags; 1999 2000 ASSERT_BO_WLOCKED(bo); 2001 2002 retval = 0; 2003 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2004 /* 2005 * If we are flushing both V_NORMAL and V_ALT buffers then 2006 * do not skip any buffers. If we are flushing only V_NORMAL 2007 * buffers then skip buffers marked as BX_ALTDATA. If we are 2008 * flushing only V_ALT buffers then skip buffers not marked 2009 * as BX_ALTDATA. 2010 */ 2011 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2012 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2013 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2014 continue; 2015 } 2016 if (nbp != NULL) { 2017 lblkno = nbp->b_lblkno; 2018 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2019 } 2020 retval = EAGAIN; 2021 error = BUF_TIMELOCK(bp, 2022 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2023 "flushbuf", slpflag, slptimeo); 2024 if (error) { 2025 BO_LOCK(bo); 2026 return (error != ENOLCK ? error : EAGAIN); 2027 } 2028 KASSERT(bp->b_bufobj == bo, 2029 ("bp %p wrong b_bufobj %p should be %p", 2030 bp, bp->b_bufobj, bo)); 2031 /* 2032 * XXX Since there are no node locks for NFS, I 2033 * believe there is a slight chance that a delayed 2034 * write will occur while sleeping just above, so 2035 * check for it. 2036 */ 2037 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2038 (flags & V_SAVE)) { 2039 bremfree(bp); 2040 bp->b_flags |= B_ASYNC; 2041 bwrite(bp); 2042 BO_LOCK(bo); 2043 return (EAGAIN); /* XXX: why not loop ? */ 2044 } 2045 bremfree(bp); 2046 bp->b_flags |= (B_INVAL | B_RELBUF); 2047 bp->b_flags &= ~B_ASYNC; 2048 brelse(bp); 2049 BO_LOCK(bo); 2050 if (nbp == NULL) 2051 break; 2052 nbp = gbincore(bo, lblkno); 2053 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2054 != xflags) 2055 break; /* nbp invalid */ 2056 } 2057 return (retval); 2058 } 2059 2060 int 2061 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2062 { 2063 struct buf *bp; 2064 int error; 2065 daddr_t lblkno; 2066 2067 ASSERT_BO_LOCKED(bo); 2068 2069 for (lblkno = startn;;) { 2070 again: 2071 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2072 if (bp == NULL || bp->b_lblkno >= endn || 2073 bp->b_lblkno < startn) 2074 break; 2075 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2076 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2077 if (error != 0) { 2078 BO_RLOCK(bo); 2079 if (error == ENOLCK) 2080 goto again; 2081 return (error); 2082 } 2083 KASSERT(bp->b_bufobj == bo, 2084 ("bp %p wrong b_bufobj %p should be %p", 2085 bp, bp->b_bufobj, bo)); 2086 lblkno = bp->b_lblkno + 1; 2087 if ((bp->b_flags & B_MANAGED) == 0) 2088 bremfree(bp); 2089 bp->b_flags |= B_RELBUF; 2090 /* 2091 * In the VMIO case, use the B_NOREUSE flag to hint that the 2092 * pages backing each buffer in the range are unlikely to be 2093 * reused. Dirty buffers will have the hint applied once 2094 * they've been written. 2095 */ 2096 if ((bp->b_flags & B_VMIO) != 0) 2097 bp->b_flags |= B_NOREUSE; 2098 brelse(bp); 2099 BO_RLOCK(bo); 2100 } 2101 return (0); 2102 } 2103 2104 /* 2105 * Truncate a file's buffer and pages to a specified length. This 2106 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2107 * sync activity. 2108 */ 2109 int 2110 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2111 { 2112 struct buf *bp, *nbp; 2113 struct bufobj *bo; 2114 daddr_t startlbn; 2115 2116 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2117 vp, blksize, (uintmax_t)length); 2118 2119 /* 2120 * Round up to the *next* lbn. 2121 */ 2122 startlbn = howmany(length, blksize); 2123 2124 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2125 2126 bo = &vp->v_bufobj; 2127 restart_unlocked: 2128 BO_LOCK(bo); 2129 2130 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2131 ; 2132 2133 if (length > 0) { 2134 restartsync: 2135 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2136 if (bp->b_lblkno > 0) 2137 continue; 2138 /* 2139 * Since we hold the vnode lock this should only 2140 * fail if we're racing with the buf daemon. 2141 */ 2142 if (BUF_LOCK(bp, 2143 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2144 BO_LOCKPTR(bo)) == ENOLCK) 2145 goto restart_unlocked; 2146 2147 VNASSERT((bp->b_flags & B_DELWRI), vp, 2148 ("buf(%p) on dirty queue without DELWRI", bp)); 2149 2150 bremfree(bp); 2151 bawrite(bp); 2152 BO_LOCK(bo); 2153 goto restartsync; 2154 } 2155 } 2156 2157 bufobj_wwait(bo, 0, 0); 2158 BO_UNLOCK(bo); 2159 vnode_pager_setsize(vp, length); 2160 2161 return (0); 2162 } 2163 2164 /* 2165 * Invalidate the cached pages of a file's buffer within the range of block 2166 * numbers [startlbn, endlbn). 2167 */ 2168 void 2169 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2170 int blksize) 2171 { 2172 struct bufobj *bo; 2173 off_t start, end; 2174 2175 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2176 2177 start = blksize * startlbn; 2178 end = blksize * endlbn; 2179 2180 bo = &vp->v_bufobj; 2181 BO_LOCK(bo); 2182 MPASS(blksize == bo->bo_bsize); 2183 2184 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2185 ; 2186 2187 BO_UNLOCK(bo); 2188 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2189 } 2190 2191 static int 2192 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2193 daddr_t startlbn, daddr_t endlbn) 2194 { 2195 struct buf *bp, *nbp; 2196 bool anyfreed; 2197 2198 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2199 ASSERT_BO_LOCKED(bo); 2200 2201 do { 2202 anyfreed = false; 2203 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2204 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2205 continue; 2206 if (BUF_LOCK(bp, 2207 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2208 BO_LOCKPTR(bo)) == ENOLCK) { 2209 BO_LOCK(bo); 2210 return (EAGAIN); 2211 } 2212 2213 bremfree(bp); 2214 bp->b_flags |= B_INVAL | B_RELBUF; 2215 bp->b_flags &= ~B_ASYNC; 2216 brelse(bp); 2217 anyfreed = true; 2218 2219 BO_LOCK(bo); 2220 if (nbp != NULL && 2221 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2222 nbp->b_vp != vp || 2223 (nbp->b_flags & B_DELWRI) != 0)) 2224 return (EAGAIN); 2225 } 2226 2227 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2228 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2229 continue; 2230 if (BUF_LOCK(bp, 2231 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2232 BO_LOCKPTR(bo)) == ENOLCK) { 2233 BO_LOCK(bo); 2234 return (EAGAIN); 2235 } 2236 bremfree(bp); 2237 bp->b_flags |= B_INVAL | B_RELBUF; 2238 bp->b_flags &= ~B_ASYNC; 2239 brelse(bp); 2240 anyfreed = true; 2241 2242 BO_LOCK(bo); 2243 if (nbp != NULL && 2244 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2245 (nbp->b_vp != vp) || 2246 (nbp->b_flags & B_DELWRI) == 0)) 2247 return (EAGAIN); 2248 } 2249 } while (anyfreed); 2250 return (0); 2251 } 2252 2253 static void 2254 buf_vlist_remove(struct buf *bp) 2255 { 2256 struct bufv *bv; 2257 2258 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2259 ASSERT_BO_WLOCKED(bp->b_bufobj); 2260 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 2261 (BX_VNDIRTY|BX_VNCLEAN), 2262 ("buf_vlist_remove: Buf %p is on two lists", bp)); 2263 if (bp->b_xflags & BX_VNDIRTY) 2264 bv = &bp->b_bufobj->bo_dirty; 2265 else 2266 bv = &bp->b_bufobj->bo_clean; 2267 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2268 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2269 bv->bv_cnt--; 2270 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2271 } 2272 2273 /* 2274 * Add the buffer to the sorted clean or dirty block list. 2275 * 2276 * NOTE: xflags is passed as a constant, optimizing this inline function! 2277 */ 2278 static void 2279 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2280 { 2281 struct bufv *bv; 2282 struct buf *n; 2283 int error; 2284 2285 ASSERT_BO_WLOCKED(bo); 2286 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2287 ("dead bo %p", bo)); 2288 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2289 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2290 bp->b_xflags |= xflags; 2291 if (xflags & BX_VNDIRTY) 2292 bv = &bo->bo_dirty; 2293 else 2294 bv = &bo->bo_clean; 2295 2296 /* 2297 * Keep the list ordered. Optimize empty list insertion. Assume 2298 * we tend to grow at the tail so lookup_le should usually be cheaper 2299 * than _ge. 2300 */ 2301 if (bv->bv_cnt == 0 || 2302 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2303 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2304 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2305 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2306 else 2307 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2308 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2309 if (error) 2310 panic("buf_vlist_add: Preallocated nodes insufficient."); 2311 bv->bv_cnt++; 2312 } 2313 2314 /* 2315 * Look up a buffer using the buffer tries. 2316 */ 2317 struct buf * 2318 gbincore(struct bufobj *bo, daddr_t lblkno) 2319 { 2320 struct buf *bp; 2321 2322 ASSERT_BO_LOCKED(bo); 2323 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2324 if (bp != NULL) 2325 return (bp); 2326 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2327 } 2328 2329 /* 2330 * Associate a buffer with a vnode. 2331 */ 2332 void 2333 bgetvp(struct vnode *vp, struct buf *bp) 2334 { 2335 struct bufobj *bo; 2336 2337 bo = &vp->v_bufobj; 2338 ASSERT_BO_WLOCKED(bo); 2339 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2340 2341 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2342 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2343 ("bgetvp: bp already attached! %p", bp)); 2344 2345 vhold(vp); 2346 bp->b_vp = vp; 2347 bp->b_bufobj = bo; 2348 /* 2349 * Insert onto list for new vnode. 2350 */ 2351 buf_vlist_add(bp, bo, BX_VNCLEAN); 2352 } 2353 2354 /* 2355 * Disassociate a buffer from a vnode. 2356 */ 2357 void 2358 brelvp(struct buf *bp) 2359 { 2360 struct bufobj *bo; 2361 struct vnode *vp; 2362 2363 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2364 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2365 2366 /* 2367 * Delete from old vnode list, if on one. 2368 */ 2369 vp = bp->b_vp; /* XXX */ 2370 bo = bp->b_bufobj; 2371 BO_LOCK(bo); 2372 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2373 buf_vlist_remove(bp); 2374 else 2375 panic("brelvp: Buffer %p not on queue.", bp); 2376 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2377 bo->bo_flag &= ~BO_ONWORKLST; 2378 mtx_lock(&sync_mtx); 2379 LIST_REMOVE(bo, bo_synclist); 2380 syncer_worklist_len--; 2381 mtx_unlock(&sync_mtx); 2382 } 2383 bp->b_vp = NULL; 2384 bp->b_bufobj = NULL; 2385 BO_UNLOCK(bo); 2386 vdrop(vp); 2387 } 2388 2389 /* 2390 * Add an item to the syncer work queue. 2391 */ 2392 static void 2393 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2394 { 2395 int slot; 2396 2397 ASSERT_BO_WLOCKED(bo); 2398 2399 mtx_lock(&sync_mtx); 2400 if (bo->bo_flag & BO_ONWORKLST) 2401 LIST_REMOVE(bo, bo_synclist); 2402 else { 2403 bo->bo_flag |= BO_ONWORKLST; 2404 syncer_worklist_len++; 2405 } 2406 2407 if (delay > syncer_maxdelay - 2) 2408 delay = syncer_maxdelay - 2; 2409 slot = (syncer_delayno + delay) & syncer_mask; 2410 2411 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2412 mtx_unlock(&sync_mtx); 2413 } 2414 2415 static int 2416 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2417 { 2418 int error, len; 2419 2420 mtx_lock(&sync_mtx); 2421 len = syncer_worklist_len - sync_vnode_count; 2422 mtx_unlock(&sync_mtx); 2423 error = SYSCTL_OUT(req, &len, sizeof(len)); 2424 return (error); 2425 } 2426 2427 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2428 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2429 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2430 2431 static struct proc *updateproc; 2432 static void sched_sync(void); 2433 static struct kproc_desc up_kp = { 2434 "syncer", 2435 sched_sync, 2436 &updateproc 2437 }; 2438 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2439 2440 static int 2441 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2442 { 2443 struct vnode *vp; 2444 struct mount *mp; 2445 2446 *bo = LIST_FIRST(slp); 2447 if (*bo == NULL) 2448 return (0); 2449 vp = bo2vnode(*bo); 2450 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2451 return (1); 2452 /* 2453 * We use vhold in case the vnode does not 2454 * successfully sync. vhold prevents the vnode from 2455 * going away when we unlock the sync_mtx so that 2456 * we can acquire the vnode interlock. 2457 */ 2458 vholdl(vp); 2459 mtx_unlock(&sync_mtx); 2460 VI_UNLOCK(vp); 2461 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2462 vdrop(vp); 2463 mtx_lock(&sync_mtx); 2464 return (*bo == LIST_FIRST(slp)); 2465 } 2466 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2467 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2468 VOP_UNLOCK(vp); 2469 vn_finished_write(mp); 2470 BO_LOCK(*bo); 2471 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2472 /* 2473 * Put us back on the worklist. The worklist 2474 * routine will remove us from our current 2475 * position and then add us back in at a later 2476 * position. 2477 */ 2478 vn_syncer_add_to_worklist(*bo, syncdelay); 2479 } 2480 BO_UNLOCK(*bo); 2481 vdrop(vp); 2482 mtx_lock(&sync_mtx); 2483 return (0); 2484 } 2485 2486 static int first_printf = 1; 2487 2488 /* 2489 * System filesystem synchronizer daemon. 2490 */ 2491 static void 2492 sched_sync(void) 2493 { 2494 struct synclist *next, *slp; 2495 struct bufobj *bo; 2496 long starttime; 2497 struct thread *td = curthread; 2498 int last_work_seen; 2499 int net_worklist_len; 2500 int syncer_final_iter; 2501 int error; 2502 2503 last_work_seen = 0; 2504 syncer_final_iter = 0; 2505 syncer_state = SYNCER_RUNNING; 2506 starttime = time_uptime; 2507 td->td_pflags |= TDP_NORUNNINGBUF; 2508 2509 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2510 SHUTDOWN_PRI_LAST); 2511 2512 mtx_lock(&sync_mtx); 2513 for (;;) { 2514 if (syncer_state == SYNCER_FINAL_DELAY && 2515 syncer_final_iter == 0) { 2516 mtx_unlock(&sync_mtx); 2517 kproc_suspend_check(td->td_proc); 2518 mtx_lock(&sync_mtx); 2519 } 2520 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2521 if (syncer_state != SYNCER_RUNNING && 2522 starttime != time_uptime) { 2523 if (first_printf) { 2524 printf("\nSyncing disks, vnodes remaining... "); 2525 first_printf = 0; 2526 } 2527 printf("%d ", net_worklist_len); 2528 } 2529 starttime = time_uptime; 2530 2531 /* 2532 * Push files whose dirty time has expired. Be careful 2533 * of interrupt race on slp queue. 2534 * 2535 * Skip over empty worklist slots when shutting down. 2536 */ 2537 do { 2538 slp = &syncer_workitem_pending[syncer_delayno]; 2539 syncer_delayno += 1; 2540 if (syncer_delayno == syncer_maxdelay) 2541 syncer_delayno = 0; 2542 next = &syncer_workitem_pending[syncer_delayno]; 2543 /* 2544 * If the worklist has wrapped since the 2545 * it was emptied of all but syncer vnodes, 2546 * switch to the FINAL_DELAY state and run 2547 * for one more second. 2548 */ 2549 if (syncer_state == SYNCER_SHUTTING_DOWN && 2550 net_worklist_len == 0 && 2551 last_work_seen == syncer_delayno) { 2552 syncer_state = SYNCER_FINAL_DELAY; 2553 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2554 } 2555 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2556 syncer_worklist_len > 0); 2557 2558 /* 2559 * Keep track of the last time there was anything 2560 * on the worklist other than syncer vnodes. 2561 * Return to the SHUTTING_DOWN state if any 2562 * new work appears. 2563 */ 2564 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2565 last_work_seen = syncer_delayno; 2566 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2567 syncer_state = SYNCER_SHUTTING_DOWN; 2568 while (!LIST_EMPTY(slp)) { 2569 error = sync_vnode(slp, &bo, td); 2570 if (error == 1) { 2571 LIST_REMOVE(bo, bo_synclist); 2572 LIST_INSERT_HEAD(next, bo, bo_synclist); 2573 continue; 2574 } 2575 2576 if (first_printf == 0) { 2577 /* 2578 * Drop the sync mutex, because some watchdog 2579 * drivers need to sleep while patting 2580 */ 2581 mtx_unlock(&sync_mtx); 2582 wdog_kern_pat(WD_LASTVAL); 2583 mtx_lock(&sync_mtx); 2584 } 2585 2586 } 2587 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2588 syncer_final_iter--; 2589 /* 2590 * The variable rushjob allows the kernel to speed up the 2591 * processing of the filesystem syncer process. A rushjob 2592 * value of N tells the filesystem syncer to process the next 2593 * N seconds worth of work on its queue ASAP. Currently rushjob 2594 * is used by the soft update code to speed up the filesystem 2595 * syncer process when the incore state is getting so far 2596 * ahead of the disk that the kernel memory pool is being 2597 * threatened with exhaustion. 2598 */ 2599 if (rushjob > 0) { 2600 rushjob -= 1; 2601 continue; 2602 } 2603 /* 2604 * Just sleep for a short period of time between 2605 * iterations when shutting down to allow some I/O 2606 * to happen. 2607 * 2608 * If it has taken us less than a second to process the 2609 * current work, then wait. Otherwise start right over 2610 * again. We can still lose time if any single round 2611 * takes more than two seconds, but it does not really 2612 * matter as we are just trying to generally pace the 2613 * filesystem activity. 2614 */ 2615 if (syncer_state != SYNCER_RUNNING || 2616 time_uptime == starttime) { 2617 thread_lock(td); 2618 sched_prio(td, PPAUSE); 2619 thread_unlock(td); 2620 } 2621 if (syncer_state != SYNCER_RUNNING) 2622 cv_timedwait(&sync_wakeup, &sync_mtx, 2623 hz / SYNCER_SHUTDOWN_SPEEDUP); 2624 else if (time_uptime == starttime) 2625 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2626 } 2627 } 2628 2629 /* 2630 * Request the syncer daemon to speed up its work. 2631 * We never push it to speed up more than half of its 2632 * normal turn time, otherwise it could take over the cpu. 2633 */ 2634 int 2635 speedup_syncer(void) 2636 { 2637 int ret = 0; 2638 2639 mtx_lock(&sync_mtx); 2640 if (rushjob < syncdelay / 2) { 2641 rushjob += 1; 2642 stat_rush_requests += 1; 2643 ret = 1; 2644 } 2645 mtx_unlock(&sync_mtx); 2646 cv_broadcast(&sync_wakeup); 2647 return (ret); 2648 } 2649 2650 /* 2651 * Tell the syncer to speed up its work and run though its work 2652 * list several times, then tell it to shut down. 2653 */ 2654 static void 2655 syncer_shutdown(void *arg, int howto) 2656 { 2657 2658 if (howto & RB_NOSYNC) 2659 return; 2660 mtx_lock(&sync_mtx); 2661 syncer_state = SYNCER_SHUTTING_DOWN; 2662 rushjob = 0; 2663 mtx_unlock(&sync_mtx); 2664 cv_broadcast(&sync_wakeup); 2665 kproc_shutdown(arg, howto); 2666 } 2667 2668 void 2669 syncer_suspend(void) 2670 { 2671 2672 syncer_shutdown(updateproc, 0); 2673 } 2674 2675 void 2676 syncer_resume(void) 2677 { 2678 2679 mtx_lock(&sync_mtx); 2680 first_printf = 1; 2681 syncer_state = SYNCER_RUNNING; 2682 mtx_unlock(&sync_mtx); 2683 cv_broadcast(&sync_wakeup); 2684 kproc_resume(updateproc); 2685 } 2686 2687 /* 2688 * Reassign a buffer from one vnode to another. 2689 * Used to assign file specific control information 2690 * (indirect blocks) to the vnode to which they belong. 2691 */ 2692 void 2693 reassignbuf(struct buf *bp) 2694 { 2695 struct vnode *vp; 2696 struct bufobj *bo; 2697 int delay; 2698 #ifdef INVARIANTS 2699 struct bufv *bv; 2700 #endif 2701 2702 vp = bp->b_vp; 2703 bo = bp->b_bufobj; 2704 ++reassignbufcalls; 2705 2706 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2707 bp, bp->b_vp, bp->b_flags); 2708 /* 2709 * B_PAGING flagged buffers cannot be reassigned because their vp 2710 * is not fully linked in. 2711 */ 2712 if (bp->b_flags & B_PAGING) 2713 panic("cannot reassign paging buffer"); 2714 2715 /* 2716 * Delete from old vnode list, if on one. 2717 */ 2718 BO_LOCK(bo); 2719 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2720 buf_vlist_remove(bp); 2721 else 2722 panic("reassignbuf: Buffer %p not on queue.", bp); 2723 /* 2724 * If dirty, put on list of dirty buffers; otherwise insert onto list 2725 * of clean buffers. 2726 */ 2727 if (bp->b_flags & B_DELWRI) { 2728 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2729 switch (vp->v_type) { 2730 case VDIR: 2731 delay = dirdelay; 2732 break; 2733 case VCHR: 2734 delay = metadelay; 2735 break; 2736 default: 2737 delay = filedelay; 2738 } 2739 vn_syncer_add_to_worklist(bo, delay); 2740 } 2741 buf_vlist_add(bp, bo, BX_VNDIRTY); 2742 } else { 2743 buf_vlist_add(bp, bo, BX_VNCLEAN); 2744 2745 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2746 mtx_lock(&sync_mtx); 2747 LIST_REMOVE(bo, bo_synclist); 2748 syncer_worklist_len--; 2749 mtx_unlock(&sync_mtx); 2750 bo->bo_flag &= ~BO_ONWORKLST; 2751 } 2752 } 2753 #ifdef INVARIANTS 2754 bv = &bo->bo_clean; 2755 bp = TAILQ_FIRST(&bv->bv_hd); 2756 KASSERT(bp == NULL || bp->b_bufobj == bo, 2757 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2758 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2759 KASSERT(bp == NULL || bp->b_bufobj == bo, 2760 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2761 bv = &bo->bo_dirty; 2762 bp = TAILQ_FIRST(&bv->bv_hd); 2763 KASSERT(bp == NULL || bp->b_bufobj == bo, 2764 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2765 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2766 KASSERT(bp == NULL || bp->b_bufobj == bo, 2767 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2768 #endif 2769 BO_UNLOCK(bo); 2770 } 2771 2772 static void 2773 v_init_counters(struct vnode *vp) 2774 { 2775 2776 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2777 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2778 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2779 2780 refcount_init(&vp->v_holdcnt, 1); 2781 refcount_init(&vp->v_usecount, 1); 2782 } 2783 2784 /* 2785 * Increment si_usecount of the associated device, if any. 2786 */ 2787 static void 2788 v_incr_devcount(struct vnode *vp) 2789 { 2790 2791 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2792 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2793 dev_lock(); 2794 vp->v_rdev->si_usecount++; 2795 dev_unlock(); 2796 } 2797 } 2798 2799 /* 2800 * Decrement si_usecount of the associated device, if any. 2801 */ 2802 static void 2803 v_decr_devcount(struct vnode *vp) 2804 { 2805 2806 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2807 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2808 dev_lock(); 2809 vp->v_rdev->si_usecount--; 2810 dev_unlock(); 2811 } 2812 } 2813 2814 /* 2815 * Grab a particular vnode from the free list, increment its 2816 * reference count and lock it. VIRF_DOOMED is set if the vnode 2817 * is being destroyed. Only callers who specify LK_RETRY will 2818 * see doomed vnodes. If inactive processing was delayed in 2819 * vput try to do it here. 2820 * 2821 * usecount is manipulated using atomics without holding any locks. 2822 * 2823 * holdcnt can be manipulated using atomics without holding any locks, 2824 * except when transitioning 1<->0, in which case the interlock is held. 2825 */ 2826 enum vgetstate 2827 vget_prep(struct vnode *vp) 2828 { 2829 enum vgetstate vs; 2830 2831 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2832 vs = VGET_USECOUNT; 2833 } else { 2834 vhold(vp); 2835 vs = VGET_HOLDCNT; 2836 } 2837 return (vs); 2838 } 2839 2840 int 2841 vget(struct vnode *vp, int flags, struct thread *td) 2842 { 2843 enum vgetstate vs; 2844 2845 MPASS(td == curthread); 2846 2847 vs = vget_prep(vp); 2848 return (vget_finish(vp, flags, vs)); 2849 } 2850 2851 static int __noinline 2852 vget_finish_vchr(struct vnode *vp) 2853 { 2854 2855 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2856 2857 /* 2858 * See the comment in vget_finish before usecount bump. 2859 */ 2860 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2861 #ifdef INVARIANTS 2862 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2863 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 2864 #else 2865 refcount_release(&vp->v_holdcnt); 2866 #endif 2867 return (0); 2868 } 2869 2870 VI_LOCK(vp); 2871 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2872 #ifdef INVARIANTS 2873 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2874 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2875 #else 2876 refcount_release(&vp->v_holdcnt); 2877 #endif 2878 VI_UNLOCK(vp); 2879 return (0); 2880 } 2881 v_incr_devcount(vp); 2882 refcount_acquire(&vp->v_usecount); 2883 VI_UNLOCK(vp); 2884 return (0); 2885 } 2886 2887 int 2888 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2889 { 2890 int error, old; 2891 2892 if ((flags & LK_INTERLOCK) != 0) 2893 ASSERT_VI_LOCKED(vp, __func__); 2894 else 2895 ASSERT_VI_UNLOCKED(vp, __func__); 2896 VNPASS(vp->v_holdcnt > 0, vp); 2897 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2898 2899 error = vn_lock(vp, flags); 2900 if (__predict_false(error != 0)) { 2901 if (vs == VGET_USECOUNT) 2902 vrele(vp); 2903 else 2904 vdrop(vp); 2905 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2906 vp); 2907 return (error); 2908 } 2909 2910 if (vs == VGET_USECOUNT) 2911 return (0); 2912 2913 if (__predict_false(vp->v_type == VCHR)) 2914 return (vget_finish_vchr(vp)); 2915 2916 /* 2917 * We hold the vnode. If the usecount is 0 it will be utilized to keep 2918 * the vnode around. Otherwise someone else lended their hold count and 2919 * we have to drop ours. 2920 */ 2921 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2922 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 2923 if (old != 0) { 2924 #ifdef INVARIANTS 2925 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2926 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2927 #else 2928 refcount_release(&vp->v_holdcnt); 2929 #endif 2930 } 2931 return (0); 2932 } 2933 2934 /* 2935 * Increase the reference (use) and hold count of a vnode. 2936 * This will also remove the vnode from the free list if it is presently free. 2937 */ 2938 static void __noinline 2939 vref_vchr(struct vnode *vp, bool interlock) 2940 { 2941 2942 /* 2943 * See the comment in vget_finish before usecount bump. 2944 */ 2945 if (!interlock) { 2946 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2947 VNODE_REFCOUNT_FENCE_ACQ(); 2948 VNASSERT(vp->v_holdcnt > 0, vp, 2949 ("%s: active vnode not held", __func__)); 2950 return; 2951 } 2952 VI_LOCK(vp); 2953 /* 2954 * By the time we get here the vnode might have been doomed, at 2955 * which point the 0->1 use count transition is no longer 2956 * protected by the interlock. Since it can't bounce back to 2957 * VCHR and requires vref semantics, punt it back 2958 */ 2959 if (__predict_false(vp->v_type == VBAD)) { 2960 VI_UNLOCK(vp); 2961 vref(vp); 2962 return; 2963 } 2964 } 2965 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2966 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2967 VNODE_REFCOUNT_FENCE_ACQ(); 2968 VNASSERT(vp->v_holdcnt > 0, vp, 2969 ("%s: active vnode not held", __func__)); 2970 if (!interlock) 2971 VI_UNLOCK(vp); 2972 return; 2973 } 2974 vhold(vp); 2975 v_incr_devcount(vp); 2976 refcount_acquire(&vp->v_usecount); 2977 if (!interlock) 2978 VI_UNLOCK(vp); 2979 return; 2980 } 2981 2982 void 2983 vref(struct vnode *vp) 2984 { 2985 int old; 2986 2987 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2988 if (__predict_false(vp->v_type == VCHR)) { 2989 vref_vchr(vp, false); 2990 return; 2991 } 2992 2993 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2994 VNODE_REFCOUNT_FENCE_ACQ(); 2995 VNASSERT(vp->v_holdcnt > 0, vp, 2996 ("%s: active vnode not held", __func__)); 2997 return; 2998 } 2999 vhold(vp); 3000 /* 3001 * See the comment in vget_finish. 3002 */ 3003 old = atomic_fetchadd_int(&vp->v_usecount, 1); 3004 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 3005 if (old != 0) { 3006 #ifdef INVARIANTS 3007 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 3008 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 3009 #else 3010 refcount_release(&vp->v_holdcnt); 3011 #endif 3012 } 3013 } 3014 3015 void 3016 vrefl(struct vnode *vp) 3017 { 3018 3019 ASSERT_VI_LOCKED(vp, __func__); 3020 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3021 if (__predict_false(vp->v_type == VCHR)) { 3022 vref_vchr(vp, true); 3023 return; 3024 } 3025 vref(vp); 3026 } 3027 3028 void 3029 vrefact(struct vnode *vp) 3030 { 3031 3032 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3033 #ifdef INVARIANTS 3034 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 3035 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3036 #else 3037 refcount_acquire(&vp->v_usecount); 3038 #endif 3039 } 3040 3041 void 3042 vrefactn(struct vnode *vp, u_int n) 3043 { 3044 3045 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3046 #ifdef INVARIANTS 3047 int old = atomic_fetchadd_int(&vp->v_usecount, n); 3048 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3049 #else 3050 atomic_add_int(&vp->v_usecount, n); 3051 #endif 3052 } 3053 3054 /* 3055 * Return reference count of a vnode. 3056 * 3057 * The results of this call are only guaranteed when some mechanism is used to 3058 * stop other processes from gaining references to the vnode. This may be the 3059 * case if the caller holds the only reference. This is also useful when stale 3060 * data is acceptable as race conditions may be accounted for by some other 3061 * means. 3062 */ 3063 int 3064 vrefcnt(struct vnode *vp) 3065 { 3066 3067 return (vp->v_usecount); 3068 } 3069 3070 void 3071 vlazy(struct vnode *vp) 3072 { 3073 struct mount *mp; 3074 3075 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 3076 3077 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 3078 return; 3079 /* 3080 * We may get here for inactive routines after the vnode got doomed. 3081 */ 3082 if (VN_IS_DOOMED(vp)) 3083 return; 3084 mp = vp->v_mount; 3085 mtx_lock(&mp->mnt_listmtx); 3086 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 3087 vp->v_mflag |= VMP_LAZYLIST; 3088 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3089 mp->mnt_lazyvnodelistsize++; 3090 } 3091 mtx_unlock(&mp->mnt_listmtx); 3092 } 3093 3094 /* 3095 * This routine is only meant to be called from vgonel prior to dooming 3096 * the vnode. 3097 */ 3098 static void 3099 vunlazy_gone(struct vnode *vp) 3100 { 3101 struct mount *mp; 3102 3103 ASSERT_VOP_ELOCKED(vp, __func__); 3104 ASSERT_VI_LOCKED(vp, __func__); 3105 VNPASS(!VN_IS_DOOMED(vp), vp); 3106 3107 if (vp->v_mflag & VMP_LAZYLIST) { 3108 mp = vp->v_mount; 3109 mtx_lock(&mp->mnt_listmtx); 3110 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3111 vp->v_mflag &= ~VMP_LAZYLIST; 3112 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3113 mp->mnt_lazyvnodelistsize--; 3114 mtx_unlock(&mp->mnt_listmtx); 3115 } 3116 } 3117 3118 static void 3119 vdefer_inactive(struct vnode *vp) 3120 { 3121 3122 ASSERT_VI_LOCKED(vp, __func__); 3123 VNASSERT(vp->v_holdcnt > 0, vp, 3124 ("%s: vnode without hold count", __func__)); 3125 if (VN_IS_DOOMED(vp)) { 3126 vdropl(vp); 3127 return; 3128 } 3129 if (vp->v_iflag & VI_DEFINACT) { 3130 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3131 vdropl(vp); 3132 return; 3133 } 3134 if (vp->v_usecount > 0) { 3135 vp->v_iflag &= ~VI_OWEINACT; 3136 vdropl(vp); 3137 return; 3138 } 3139 vlazy(vp); 3140 vp->v_iflag |= VI_DEFINACT; 3141 VI_UNLOCK(vp); 3142 counter_u64_add(deferred_inact, 1); 3143 } 3144 3145 static void 3146 vdefer_inactive_unlocked(struct vnode *vp) 3147 { 3148 3149 VI_LOCK(vp); 3150 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3151 vdropl(vp); 3152 return; 3153 } 3154 vdefer_inactive(vp); 3155 } 3156 3157 enum vputx_op { VPUTX_VRELE, VPUTX_VPUT, VPUTX_VUNREF }; 3158 3159 /* 3160 * Decrement the use and hold counts for a vnode. 3161 * 3162 * See an explanation near vget() as to why atomic operation is safe. 3163 * 3164 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3165 * on the lock being held all the way until VOP_INACTIVE. This in particular 3166 * happens with UFS which adds half-constructed vnodes to the hash, where they 3167 * can be found by other code. 3168 */ 3169 static void 3170 vputx(struct vnode *vp, enum vputx_op func) 3171 { 3172 int error; 3173 bool want_unlock; 3174 3175 KASSERT(vp != NULL, ("vputx: null vp")); 3176 if (func == VPUTX_VUNREF) 3177 ASSERT_VOP_LOCKED(vp, "vunref"); 3178 else if (func == VPUTX_VPUT) 3179 ASSERT_VOP_LOCKED(vp, "vput"); 3180 ASSERT_VI_UNLOCKED(vp, __func__); 3181 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 3182 ("%s: wrong ref counts", __func__)); 3183 3184 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3185 3186 /* 3187 * We want to hold the vnode until the inactive finishes to 3188 * prevent vgone() races. We drop the use count here and the 3189 * hold count below when we're done. 3190 * 3191 * If we release the last usecount we take ownership of the hold 3192 * count which provides liveness of the vnode, in which case we 3193 * have to vdrop. 3194 */ 3195 if (__predict_false(vp->v_type == VCHR && func == VPUTX_VRELE)) { 3196 if (refcount_release_if_not_last(&vp->v_usecount)) 3197 return; 3198 VI_LOCK(vp); 3199 if (!refcount_release(&vp->v_usecount)) { 3200 VI_UNLOCK(vp); 3201 return; 3202 } 3203 } else { 3204 if (!refcount_release(&vp->v_usecount)) { 3205 if (func == VPUTX_VPUT) 3206 VOP_UNLOCK(vp); 3207 return; 3208 } 3209 VI_LOCK(vp); 3210 } 3211 v_decr_devcount(vp); 3212 /* 3213 * By the time we got here someone else might have transitioned 3214 * the count back to > 0. 3215 */ 3216 if (vp->v_usecount > 0 || vp->v_iflag & VI_DOINGINACT) 3217 goto out; 3218 3219 /* 3220 * Check if the fs wants to perform inactive processing. Note we 3221 * may be only holding the interlock, in which case it is possible 3222 * someone else called vgone on the vnode and ->v_data is now NULL. 3223 * Since vgone performs inactive on its own there is nothing to do 3224 * here but to drop our hold count. 3225 */ 3226 if (__predict_false(VN_IS_DOOMED(vp)) || 3227 VOP_NEED_INACTIVE(vp) == 0) 3228 goto out; 3229 3230 /* 3231 * We must call VOP_INACTIVE with the node locked. Mark 3232 * as VI_DOINGINACT to avoid recursion. 3233 */ 3234 vp->v_iflag |= VI_OWEINACT; 3235 want_unlock = false; 3236 error = 0; 3237 switch (func) { 3238 case VPUTX_VRELE: 3239 switch (VOP_ISLOCKED(vp)) { 3240 case LK_EXCLUSIVE: 3241 break; 3242 case LK_EXCLOTHER: 3243 case 0: 3244 want_unlock = true; 3245 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3246 VI_LOCK(vp); 3247 break; 3248 default: 3249 /* 3250 * The lock has at least one sharer, but we have no way 3251 * to conclude whether this is us. Play it safe and 3252 * defer processing. 3253 */ 3254 error = EAGAIN; 3255 break; 3256 } 3257 break; 3258 case VPUTX_VPUT: 3259 want_unlock = true; 3260 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3261 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3262 LK_NOWAIT); 3263 VI_LOCK(vp); 3264 } 3265 break; 3266 case VPUTX_VUNREF: 3267 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3268 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3269 VI_LOCK(vp); 3270 } 3271 break; 3272 } 3273 if (error == 0) { 3274 vinactive(vp); 3275 if (want_unlock) 3276 VOP_UNLOCK(vp); 3277 vdropl(vp); 3278 } else { 3279 vdefer_inactive(vp); 3280 } 3281 return; 3282 out: 3283 if (func == VPUTX_VPUT) 3284 VOP_UNLOCK(vp); 3285 vdropl(vp); 3286 } 3287 3288 /* 3289 * Vnode put/release. 3290 * If count drops to zero, call inactive routine and return to freelist. 3291 */ 3292 void 3293 vrele(struct vnode *vp) 3294 { 3295 3296 vputx(vp, VPUTX_VRELE); 3297 } 3298 3299 /* 3300 * Release an already locked vnode. This give the same effects as 3301 * unlock+vrele(), but takes less time and avoids releasing and 3302 * re-aquiring the lock (as vrele() acquires the lock internally.) 3303 */ 3304 void 3305 vput(struct vnode *vp) 3306 { 3307 3308 vputx(vp, VPUTX_VPUT); 3309 } 3310 3311 /* 3312 * Release an exclusively locked vnode. Do not unlock the vnode lock. 3313 */ 3314 void 3315 vunref(struct vnode *vp) 3316 { 3317 3318 vputx(vp, VPUTX_VUNREF); 3319 } 3320 3321 void 3322 vhold(struct vnode *vp) 3323 { 3324 struct vdbatch *vd; 3325 int old; 3326 3327 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3328 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3329 VNASSERT(old >= 0, vp, ("%s: wrong hold count %d", __func__, old)); 3330 if (old != 0) 3331 return; 3332 critical_enter(); 3333 vd = DPCPU_PTR(vd); 3334 vd->freevnodes--; 3335 critical_exit(); 3336 } 3337 3338 void 3339 vholdl(struct vnode *vp) 3340 { 3341 3342 ASSERT_VI_LOCKED(vp, __func__); 3343 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3344 vhold(vp); 3345 } 3346 3347 void 3348 vholdnz(struct vnode *vp) 3349 { 3350 3351 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3352 #ifdef INVARIANTS 3353 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3354 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 3355 #else 3356 atomic_add_int(&vp->v_holdcnt, 1); 3357 #endif 3358 } 3359 3360 static void __noinline 3361 vdbatch_process(struct vdbatch *vd) 3362 { 3363 struct vnode *vp; 3364 int i; 3365 3366 mtx_assert(&vd->lock, MA_OWNED); 3367 MPASS(curthread->td_pinned > 0); 3368 MPASS(vd->index == VDBATCH_SIZE); 3369 3370 mtx_lock(&vnode_list_mtx); 3371 critical_enter(); 3372 freevnodes += vd->freevnodes; 3373 for (i = 0; i < VDBATCH_SIZE; i++) { 3374 vp = vd->tab[i]; 3375 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3376 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3377 MPASS(vp->v_dbatchcpu != NOCPU); 3378 vp->v_dbatchcpu = NOCPU; 3379 } 3380 mtx_unlock(&vnode_list_mtx); 3381 vd->freevnodes = 0; 3382 bzero(vd->tab, sizeof(vd->tab)); 3383 vd->index = 0; 3384 critical_exit(); 3385 } 3386 3387 static void 3388 vdbatch_enqueue(struct vnode *vp) 3389 { 3390 struct vdbatch *vd; 3391 3392 ASSERT_VI_LOCKED(vp, __func__); 3393 VNASSERT(!VN_IS_DOOMED(vp), vp, 3394 ("%s: deferring requeue of a doomed vnode", __func__)); 3395 3396 critical_enter(); 3397 vd = DPCPU_PTR(vd); 3398 vd->freevnodes++; 3399 if (vp->v_dbatchcpu != NOCPU) { 3400 VI_UNLOCK(vp); 3401 critical_exit(); 3402 return; 3403 } 3404 3405 sched_pin(); 3406 critical_exit(); 3407 mtx_lock(&vd->lock); 3408 MPASS(vd->index < VDBATCH_SIZE); 3409 MPASS(vd->tab[vd->index] == NULL); 3410 /* 3411 * A hack: we depend on being pinned so that we know what to put in 3412 * ->v_dbatchcpu. 3413 */ 3414 vp->v_dbatchcpu = curcpu; 3415 vd->tab[vd->index] = vp; 3416 vd->index++; 3417 VI_UNLOCK(vp); 3418 if (vd->index == VDBATCH_SIZE) 3419 vdbatch_process(vd); 3420 mtx_unlock(&vd->lock); 3421 sched_unpin(); 3422 } 3423 3424 /* 3425 * This routine must only be called for vnodes which are about to be 3426 * deallocated. Supporting dequeue for arbitrary vndoes would require 3427 * validating that the locked batch matches. 3428 */ 3429 static void 3430 vdbatch_dequeue(struct vnode *vp) 3431 { 3432 struct vdbatch *vd; 3433 int i; 3434 short cpu; 3435 3436 VNASSERT(vp->v_type == VBAD || vp->v_type == VNON, vp, 3437 ("%s: called for a used vnode\n", __func__)); 3438 3439 cpu = vp->v_dbatchcpu; 3440 if (cpu == NOCPU) 3441 return; 3442 3443 vd = DPCPU_ID_PTR(cpu, vd); 3444 mtx_lock(&vd->lock); 3445 for (i = 0; i < vd->index; i++) { 3446 if (vd->tab[i] != vp) 3447 continue; 3448 vp->v_dbatchcpu = NOCPU; 3449 vd->index--; 3450 vd->tab[i] = vd->tab[vd->index]; 3451 vd->tab[vd->index] = NULL; 3452 break; 3453 } 3454 mtx_unlock(&vd->lock); 3455 /* 3456 * Either we dequeued the vnode above or the target CPU beat us to it. 3457 */ 3458 MPASS(vp->v_dbatchcpu == NOCPU); 3459 } 3460 3461 /* 3462 * Drop the hold count of the vnode. If this is the last reference to 3463 * the vnode we place it on the free list unless it has been vgone'd 3464 * (marked VIRF_DOOMED) in which case we will free it. 3465 * 3466 * Because the vnode vm object keeps a hold reference on the vnode if 3467 * there is at least one resident non-cached page, the vnode cannot 3468 * leave the active list without the page cleanup done. 3469 */ 3470 static void 3471 vdrop_deactivate(struct vnode *vp) 3472 { 3473 struct mount *mp; 3474 3475 ASSERT_VI_LOCKED(vp, __func__); 3476 /* 3477 * Mark a vnode as free: remove it from its active list 3478 * and put it up for recycling on the freelist. 3479 */ 3480 VNASSERT(!VN_IS_DOOMED(vp), vp, 3481 ("vdrop: returning doomed vnode")); 3482 VNASSERT(vp->v_op != NULL, vp, 3483 ("vdrop: vnode already reclaimed.")); 3484 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 3485 ("vnode with VI_OWEINACT set")); 3486 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, 3487 ("vnode with VI_DEFINACT set")); 3488 if (vp->v_mflag & VMP_LAZYLIST) { 3489 mp = vp->v_mount; 3490 mtx_lock(&mp->mnt_listmtx); 3491 VNASSERT(vp->v_mflag & VMP_LAZYLIST, vp, ("lost VMP_LAZYLIST")); 3492 /* 3493 * Don't remove the vnode from the lazy list if another thread 3494 * has increased the hold count. It may have re-enqueued the 3495 * vnode to the lazy list and is now responsible for its 3496 * removal. 3497 */ 3498 if (vp->v_holdcnt == 0) { 3499 vp->v_mflag &= ~VMP_LAZYLIST; 3500 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3501 mp->mnt_lazyvnodelistsize--; 3502 } 3503 mtx_unlock(&mp->mnt_listmtx); 3504 } 3505 vdbatch_enqueue(vp); 3506 } 3507 3508 void 3509 vdrop(struct vnode *vp) 3510 { 3511 3512 ASSERT_VI_UNLOCKED(vp, __func__); 3513 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3514 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3515 return; 3516 VI_LOCK(vp); 3517 vdropl(vp); 3518 } 3519 3520 void 3521 vdropl(struct vnode *vp) 3522 { 3523 3524 ASSERT_VI_LOCKED(vp, __func__); 3525 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3526 if (!refcount_release(&vp->v_holdcnt)) { 3527 VI_UNLOCK(vp); 3528 return; 3529 } 3530 if (VN_IS_DOOMED(vp)) { 3531 freevnode(vp); 3532 return; 3533 } 3534 vdrop_deactivate(vp); 3535 } 3536 3537 /* 3538 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3539 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3540 */ 3541 static void 3542 vinactivef(struct vnode *vp) 3543 { 3544 struct vm_object *obj; 3545 3546 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3547 ASSERT_VI_LOCKED(vp, "vinactive"); 3548 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3549 ("vinactive: recursed on VI_DOINGINACT")); 3550 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3551 vp->v_iflag |= VI_DOINGINACT; 3552 vp->v_iflag &= ~VI_OWEINACT; 3553 VI_UNLOCK(vp); 3554 /* 3555 * Before moving off the active list, we must be sure that any 3556 * modified pages are converted into the vnode's dirty 3557 * buffers, since these will no longer be checked once the 3558 * vnode is on the inactive list. 3559 * 3560 * The write-out of the dirty pages is asynchronous. At the 3561 * point that VOP_INACTIVE() is called, there could still be 3562 * pending I/O and dirty pages in the object. 3563 */ 3564 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3565 vm_object_mightbedirty(obj)) { 3566 VM_OBJECT_WLOCK(obj); 3567 vm_object_page_clean(obj, 0, 0, 0); 3568 VM_OBJECT_WUNLOCK(obj); 3569 } 3570 VOP_INACTIVE(vp, curthread); 3571 VI_LOCK(vp); 3572 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3573 ("vinactive: lost VI_DOINGINACT")); 3574 vp->v_iflag &= ~VI_DOINGINACT; 3575 } 3576 3577 void 3578 vinactive(struct vnode *vp) 3579 { 3580 3581 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3582 ASSERT_VI_LOCKED(vp, "vinactive"); 3583 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3584 3585 if ((vp->v_iflag & VI_OWEINACT) == 0) 3586 return; 3587 if (vp->v_iflag & VI_DOINGINACT) 3588 return; 3589 if (vp->v_usecount > 0) { 3590 vp->v_iflag &= ~VI_OWEINACT; 3591 return; 3592 } 3593 vinactivef(vp); 3594 } 3595 3596 /* 3597 * Remove any vnodes in the vnode table belonging to mount point mp. 3598 * 3599 * If FORCECLOSE is not specified, there should not be any active ones, 3600 * return error if any are found (nb: this is a user error, not a 3601 * system error). If FORCECLOSE is specified, detach any active vnodes 3602 * that are found. 3603 * 3604 * If WRITECLOSE is set, only flush out regular file vnodes open for 3605 * writing. 3606 * 3607 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3608 * 3609 * `rootrefs' specifies the base reference count for the root vnode 3610 * of this filesystem. The root vnode is considered busy if its 3611 * v_usecount exceeds this value. On a successful return, vflush(, td) 3612 * will call vrele() on the root vnode exactly rootrefs times. 3613 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3614 * be zero. 3615 */ 3616 #ifdef DIAGNOSTIC 3617 static int busyprt = 0; /* print out busy vnodes */ 3618 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3619 #endif 3620 3621 int 3622 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3623 { 3624 struct vnode *vp, *mvp, *rootvp = NULL; 3625 struct vattr vattr; 3626 int busy = 0, error; 3627 3628 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3629 rootrefs, flags); 3630 if (rootrefs > 0) { 3631 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3632 ("vflush: bad args")); 3633 /* 3634 * Get the filesystem root vnode. We can vput() it 3635 * immediately, since with rootrefs > 0, it won't go away. 3636 */ 3637 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3638 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3639 __func__, error); 3640 return (error); 3641 } 3642 vput(rootvp); 3643 } 3644 loop: 3645 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3646 vholdl(vp); 3647 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3648 if (error) { 3649 vdrop(vp); 3650 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3651 goto loop; 3652 } 3653 /* 3654 * Skip over a vnodes marked VV_SYSTEM. 3655 */ 3656 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3657 VOP_UNLOCK(vp); 3658 vdrop(vp); 3659 continue; 3660 } 3661 /* 3662 * If WRITECLOSE is set, flush out unlinked but still open 3663 * files (even if open only for reading) and regular file 3664 * vnodes open for writing. 3665 */ 3666 if (flags & WRITECLOSE) { 3667 if (vp->v_object != NULL) { 3668 VM_OBJECT_WLOCK(vp->v_object); 3669 vm_object_page_clean(vp->v_object, 0, 0, 0); 3670 VM_OBJECT_WUNLOCK(vp->v_object); 3671 } 3672 error = VOP_FSYNC(vp, MNT_WAIT, td); 3673 if (error != 0) { 3674 VOP_UNLOCK(vp); 3675 vdrop(vp); 3676 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3677 return (error); 3678 } 3679 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3680 VI_LOCK(vp); 3681 3682 if ((vp->v_type == VNON || 3683 (error == 0 && vattr.va_nlink > 0)) && 3684 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3685 VOP_UNLOCK(vp); 3686 vdropl(vp); 3687 continue; 3688 } 3689 } else 3690 VI_LOCK(vp); 3691 /* 3692 * With v_usecount == 0, all we need to do is clear out the 3693 * vnode data structures and we are done. 3694 * 3695 * If FORCECLOSE is set, forcibly close the vnode. 3696 */ 3697 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3698 vgonel(vp); 3699 } else { 3700 busy++; 3701 #ifdef DIAGNOSTIC 3702 if (busyprt) 3703 vn_printf(vp, "vflush: busy vnode "); 3704 #endif 3705 } 3706 VOP_UNLOCK(vp); 3707 vdropl(vp); 3708 } 3709 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3710 /* 3711 * If just the root vnode is busy, and if its refcount 3712 * is equal to `rootrefs', then go ahead and kill it. 3713 */ 3714 VI_LOCK(rootvp); 3715 KASSERT(busy > 0, ("vflush: not busy")); 3716 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3717 ("vflush: usecount %d < rootrefs %d", 3718 rootvp->v_usecount, rootrefs)); 3719 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3720 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3721 vgone(rootvp); 3722 VOP_UNLOCK(rootvp); 3723 busy = 0; 3724 } else 3725 VI_UNLOCK(rootvp); 3726 } 3727 if (busy) { 3728 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3729 busy); 3730 return (EBUSY); 3731 } 3732 for (; rootrefs > 0; rootrefs--) 3733 vrele(rootvp); 3734 return (0); 3735 } 3736 3737 /* 3738 * Recycle an unused vnode to the front of the free list. 3739 */ 3740 int 3741 vrecycle(struct vnode *vp) 3742 { 3743 int recycled; 3744 3745 VI_LOCK(vp); 3746 recycled = vrecyclel(vp); 3747 VI_UNLOCK(vp); 3748 return (recycled); 3749 } 3750 3751 /* 3752 * vrecycle, with the vp interlock held. 3753 */ 3754 int 3755 vrecyclel(struct vnode *vp) 3756 { 3757 int recycled; 3758 3759 ASSERT_VOP_ELOCKED(vp, __func__); 3760 ASSERT_VI_LOCKED(vp, __func__); 3761 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3762 recycled = 0; 3763 if (vp->v_usecount == 0) { 3764 recycled = 1; 3765 vgonel(vp); 3766 } 3767 return (recycled); 3768 } 3769 3770 /* 3771 * Eliminate all activity associated with a vnode 3772 * in preparation for reuse. 3773 */ 3774 void 3775 vgone(struct vnode *vp) 3776 { 3777 VI_LOCK(vp); 3778 vgonel(vp); 3779 VI_UNLOCK(vp); 3780 } 3781 3782 static void 3783 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3784 struct vnode *lowervp __unused) 3785 { 3786 } 3787 3788 /* 3789 * Notify upper mounts about reclaimed or unlinked vnode. 3790 */ 3791 void 3792 vfs_notify_upper(struct vnode *vp, int event) 3793 { 3794 static struct vfsops vgonel_vfsops = { 3795 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3796 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3797 }; 3798 struct mount *mp, *ump, *mmp; 3799 3800 mp = vp->v_mount; 3801 if (mp == NULL) 3802 return; 3803 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3804 return; 3805 3806 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3807 mmp->mnt_op = &vgonel_vfsops; 3808 mmp->mnt_kern_flag |= MNTK_MARKER; 3809 MNT_ILOCK(mp); 3810 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3811 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3812 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3813 ump = TAILQ_NEXT(ump, mnt_upper_link); 3814 continue; 3815 } 3816 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3817 MNT_IUNLOCK(mp); 3818 switch (event) { 3819 case VFS_NOTIFY_UPPER_RECLAIM: 3820 VFS_RECLAIM_LOWERVP(ump, vp); 3821 break; 3822 case VFS_NOTIFY_UPPER_UNLINK: 3823 VFS_UNLINK_LOWERVP(ump, vp); 3824 break; 3825 default: 3826 KASSERT(0, ("invalid event %d", event)); 3827 break; 3828 } 3829 MNT_ILOCK(mp); 3830 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3831 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3832 } 3833 free(mmp, M_TEMP); 3834 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3835 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3836 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3837 wakeup(&mp->mnt_uppers); 3838 } 3839 MNT_IUNLOCK(mp); 3840 } 3841 3842 /* 3843 * vgone, with the vp interlock held. 3844 */ 3845 static void 3846 vgonel(struct vnode *vp) 3847 { 3848 struct thread *td; 3849 struct mount *mp; 3850 vm_object_t object; 3851 bool active, oweinact; 3852 3853 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3854 ASSERT_VI_LOCKED(vp, "vgonel"); 3855 VNASSERT(vp->v_holdcnt, vp, 3856 ("vgonel: vp %p has no reference.", vp)); 3857 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3858 td = curthread; 3859 3860 /* 3861 * Don't vgonel if we're already doomed. 3862 */ 3863 if (vp->v_irflag & VIRF_DOOMED) 3864 return; 3865 vunlazy_gone(vp); 3866 vp->v_irflag |= VIRF_DOOMED; 3867 3868 /* 3869 * Check to see if the vnode is in use. If so, we have to call 3870 * VOP_CLOSE() and VOP_INACTIVE(). 3871 */ 3872 active = vp->v_usecount > 0; 3873 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 3874 /* 3875 * If we need to do inactive VI_OWEINACT will be set. 3876 */ 3877 if (vp->v_iflag & VI_DEFINACT) { 3878 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3879 vp->v_iflag &= ~VI_DEFINACT; 3880 vdropl(vp); 3881 } else { 3882 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 3883 VI_UNLOCK(vp); 3884 } 3885 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3886 3887 /* 3888 * If purging an active vnode, it must be closed and 3889 * deactivated before being reclaimed. 3890 */ 3891 if (active) 3892 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3893 if (oweinact || active) { 3894 VI_LOCK(vp); 3895 vinactivef(vp); 3896 VI_UNLOCK(vp); 3897 } 3898 if (vp->v_type == VSOCK) 3899 vfs_unp_reclaim(vp); 3900 3901 /* 3902 * Clean out any buffers associated with the vnode. 3903 * If the flush fails, just toss the buffers. 3904 */ 3905 mp = NULL; 3906 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3907 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3908 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3909 while (vinvalbuf(vp, 0, 0, 0) != 0) 3910 ; 3911 } 3912 3913 BO_LOCK(&vp->v_bufobj); 3914 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3915 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3916 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3917 vp->v_bufobj.bo_clean.bv_cnt == 0, 3918 ("vp %p bufobj not invalidated", vp)); 3919 3920 /* 3921 * For VMIO bufobj, BO_DEAD is set later, or in 3922 * vm_object_terminate() after the object's page queue is 3923 * flushed. 3924 */ 3925 object = vp->v_bufobj.bo_object; 3926 if (object == NULL) 3927 vp->v_bufobj.bo_flag |= BO_DEAD; 3928 BO_UNLOCK(&vp->v_bufobj); 3929 3930 /* 3931 * Handle the VM part. Tmpfs handles v_object on its own (the 3932 * OBJT_VNODE check). Nullfs or other bypassing filesystems 3933 * should not touch the object borrowed from the lower vnode 3934 * (the handle check). 3935 */ 3936 if (object != NULL && object->type == OBJT_VNODE && 3937 object->handle == vp) 3938 vnode_destroy_vobject(vp); 3939 3940 /* 3941 * Reclaim the vnode. 3942 */ 3943 if (VOP_RECLAIM(vp, td)) 3944 panic("vgone: cannot reclaim"); 3945 if (mp != NULL) 3946 vn_finished_secondary_write(mp); 3947 VNASSERT(vp->v_object == NULL, vp, 3948 ("vop_reclaim left v_object vp=%p", vp)); 3949 /* 3950 * Clear the advisory locks and wake up waiting threads. 3951 */ 3952 (void)VOP_ADVLOCKPURGE(vp); 3953 vp->v_lockf = NULL; 3954 /* 3955 * Delete from old mount point vnode list. 3956 */ 3957 delmntque(vp); 3958 cache_purge(vp); 3959 /* 3960 * Done with purge, reset to the standard lock and invalidate 3961 * the vnode. 3962 */ 3963 VI_LOCK(vp); 3964 vp->v_vnlock = &vp->v_lock; 3965 vp->v_op = &dead_vnodeops; 3966 vp->v_type = VBAD; 3967 } 3968 3969 /* 3970 * Calculate the total number of references to a special device. 3971 */ 3972 int 3973 vcount(struct vnode *vp) 3974 { 3975 int count; 3976 3977 dev_lock(); 3978 count = vp->v_rdev->si_usecount; 3979 dev_unlock(); 3980 return (count); 3981 } 3982 3983 /* 3984 * Print out a description of a vnode. 3985 */ 3986 static char *typename[] = 3987 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3988 "VMARKER"}; 3989 3990 void 3991 vn_printf(struct vnode *vp, const char *fmt, ...) 3992 { 3993 va_list ap; 3994 char buf[256], buf2[16]; 3995 u_long flags; 3996 3997 va_start(ap, fmt); 3998 vprintf(fmt, ap); 3999 va_end(ap); 4000 printf("%p: ", (void *)vp); 4001 printf("type %s\n", typename[vp->v_type]); 4002 printf(" usecount %d, writecount %d, refcount %d", 4003 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 4004 switch (vp->v_type) { 4005 case VDIR: 4006 printf(" mountedhere %p\n", vp->v_mountedhere); 4007 break; 4008 case VCHR: 4009 printf(" rdev %p\n", vp->v_rdev); 4010 break; 4011 case VSOCK: 4012 printf(" socket %p\n", vp->v_unpcb); 4013 break; 4014 case VFIFO: 4015 printf(" fifoinfo %p\n", vp->v_fifoinfo); 4016 break; 4017 default: 4018 printf("\n"); 4019 break; 4020 } 4021 buf[0] = '\0'; 4022 buf[1] = '\0'; 4023 if (vp->v_irflag & VIRF_DOOMED) 4024 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 4025 flags = vp->v_irflag & ~(VIRF_DOOMED); 4026 if (flags != 0) { 4027 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 4028 strlcat(buf, buf2, sizeof(buf)); 4029 } 4030 if (vp->v_vflag & VV_ROOT) 4031 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4032 if (vp->v_vflag & VV_ISTTY) 4033 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4034 if (vp->v_vflag & VV_NOSYNC) 4035 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4036 if (vp->v_vflag & VV_ETERNALDEV) 4037 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4038 if (vp->v_vflag & VV_CACHEDLABEL) 4039 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4040 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4041 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4042 if (vp->v_vflag & VV_COPYONWRITE) 4043 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4044 if (vp->v_vflag & VV_SYSTEM) 4045 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4046 if (vp->v_vflag & VV_PROCDEP) 4047 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4048 if (vp->v_vflag & VV_NOKNOTE) 4049 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 4050 if (vp->v_vflag & VV_DELETED) 4051 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4052 if (vp->v_vflag & VV_MD) 4053 strlcat(buf, "|VV_MD", sizeof(buf)); 4054 if (vp->v_vflag & VV_FORCEINSMQ) 4055 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4056 if (vp->v_vflag & VV_READLINK) 4057 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4058 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4059 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 4060 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 4061 if (flags != 0) { 4062 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4063 strlcat(buf, buf2, sizeof(buf)); 4064 } 4065 if (vp->v_iflag & VI_TEXT_REF) 4066 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 4067 if (vp->v_iflag & VI_MOUNT) 4068 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4069 if (vp->v_iflag & VI_DOINGINACT) 4070 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4071 if (vp->v_iflag & VI_OWEINACT) 4072 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4073 if (vp->v_iflag & VI_DEFINACT) 4074 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4075 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | 4076 VI_OWEINACT | VI_DEFINACT); 4077 if (flags != 0) { 4078 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4079 strlcat(buf, buf2, sizeof(buf)); 4080 } 4081 if (vp->v_mflag & VMP_LAZYLIST) 4082 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4083 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4084 if (flags != 0) { 4085 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4086 strlcat(buf, buf2, sizeof(buf)); 4087 } 4088 printf(" flags (%s)\n", buf + 1); 4089 if (mtx_owned(VI_MTX(vp))) 4090 printf(" VI_LOCKed"); 4091 if (vp->v_object != NULL) 4092 printf(" v_object %p ref %d pages %d " 4093 "cleanbuf %d dirtybuf %d\n", 4094 vp->v_object, vp->v_object->ref_count, 4095 vp->v_object->resident_page_count, 4096 vp->v_bufobj.bo_clean.bv_cnt, 4097 vp->v_bufobj.bo_dirty.bv_cnt); 4098 printf(" "); 4099 lockmgr_printinfo(vp->v_vnlock); 4100 if (vp->v_data != NULL) 4101 VOP_PRINT(vp); 4102 } 4103 4104 #ifdef DDB 4105 /* 4106 * List all of the locked vnodes in the system. 4107 * Called when debugging the kernel. 4108 */ 4109 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 4110 { 4111 struct mount *mp; 4112 struct vnode *vp; 4113 4114 /* 4115 * Note: because this is DDB, we can't obey the locking semantics 4116 * for these structures, which means we could catch an inconsistent 4117 * state and dereference a nasty pointer. Not much to be done 4118 * about that. 4119 */ 4120 db_printf("Locked vnodes\n"); 4121 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4122 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4123 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4124 vn_printf(vp, "vnode "); 4125 } 4126 } 4127 } 4128 4129 /* 4130 * Show details about the given vnode. 4131 */ 4132 DB_SHOW_COMMAND(vnode, db_show_vnode) 4133 { 4134 struct vnode *vp; 4135 4136 if (!have_addr) 4137 return; 4138 vp = (struct vnode *)addr; 4139 vn_printf(vp, "vnode "); 4140 } 4141 4142 /* 4143 * Show details about the given mount point. 4144 */ 4145 DB_SHOW_COMMAND(mount, db_show_mount) 4146 { 4147 struct mount *mp; 4148 struct vfsopt *opt; 4149 struct statfs *sp; 4150 struct vnode *vp; 4151 char buf[512]; 4152 uint64_t mflags; 4153 u_int flags; 4154 4155 if (!have_addr) { 4156 /* No address given, print short info about all mount points. */ 4157 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4158 db_printf("%p %s on %s (%s)\n", mp, 4159 mp->mnt_stat.f_mntfromname, 4160 mp->mnt_stat.f_mntonname, 4161 mp->mnt_stat.f_fstypename); 4162 if (db_pager_quit) 4163 break; 4164 } 4165 db_printf("\nMore info: show mount <addr>\n"); 4166 return; 4167 } 4168 4169 mp = (struct mount *)addr; 4170 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4171 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4172 4173 buf[0] = '\0'; 4174 mflags = mp->mnt_flag; 4175 #define MNT_FLAG(flag) do { \ 4176 if (mflags & (flag)) { \ 4177 if (buf[0] != '\0') \ 4178 strlcat(buf, ", ", sizeof(buf)); \ 4179 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4180 mflags &= ~(flag); \ 4181 } \ 4182 } while (0) 4183 MNT_FLAG(MNT_RDONLY); 4184 MNT_FLAG(MNT_SYNCHRONOUS); 4185 MNT_FLAG(MNT_NOEXEC); 4186 MNT_FLAG(MNT_NOSUID); 4187 MNT_FLAG(MNT_NFS4ACLS); 4188 MNT_FLAG(MNT_UNION); 4189 MNT_FLAG(MNT_ASYNC); 4190 MNT_FLAG(MNT_SUIDDIR); 4191 MNT_FLAG(MNT_SOFTDEP); 4192 MNT_FLAG(MNT_NOSYMFOLLOW); 4193 MNT_FLAG(MNT_GJOURNAL); 4194 MNT_FLAG(MNT_MULTILABEL); 4195 MNT_FLAG(MNT_ACLS); 4196 MNT_FLAG(MNT_NOATIME); 4197 MNT_FLAG(MNT_NOCLUSTERR); 4198 MNT_FLAG(MNT_NOCLUSTERW); 4199 MNT_FLAG(MNT_SUJ); 4200 MNT_FLAG(MNT_EXRDONLY); 4201 MNT_FLAG(MNT_EXPORTED); 4202 MNT_FLAG(MNT_DEFEXPORTED); 4203 MNT_FLAG(MNT_EXPORTANON); 4204 MNT_FLAG(MNT_EXKERB); 4205 MNT_FLAG(MNT_EXPUBLIC); 4206 MNT_FLAG(MNT_LOCAL); 4207 MNT_FLAG(MNT_QUOTA); 4208 MNT_FLAG(MNT_ROOTFS); 4209 MNT_FLAG(MNT_USER); 4210 MNT_FLAG(MNT_IGNORE); 4211 MNT_FLAG(MNT_UPDATE); 4212 MNT_FLAG(MNT_DELEXPORT); 4213 MNT_FLAG(MNT_RELOAD); 4214 MNT_FLAG(MNT_FORCE); 4215 MNT_FLAG(MNT_SNAPSHOT); 4216 MNT_FLAG(MNT_BYFSID); 4217 #undef MNT_FLAG 4218 if (mflags != 0) { 4219 if (buf[0] != '\0') 4220 strlcat(buf, ", ", sizeof(buf)); 4221 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4222 "0x%016jx", mflags); 4223 } 4224 db_printf(" mnt_flag = %s\n", buf); 4225 4226 buf[0] = '\0'; 4227 flags = mp->mnt_kern_flag; 4228 #define MNT_KERN_FLAG(flag) do { \ 4229 if (flags & (flag)) { \ 4230 if (buf[0] != '\0') \ 4231 strlcat(buf, ", ", sizeof(buf)); \ 4232 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4233 flags &= ~(flag); \ 4234 } \ 4235 } while (0) 4236 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4237 MNT_KERN_FLAG(MNTK_ASYNC); 4238 MNT_KERN_FLAG(MNTK_SOFTDEP); 4239 MNT_KERN_FLAG(MNTK_DRAINING); 4240 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4241 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4242 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4243 MNT_KERN_FLAG(MNTK_NO_IOPF); 4244 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 4245 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 4246 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 4247 MNT_KERN_FLAG(MNTK_MARKER); 4248 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4249 MNT_KERN_FLAG(MNTK_NOASYNC); 4250 MNT_KERN_FLAG(MNTK_UNMOUNT); 4251 MNT_KERN_FLAG(MNTK_MWAIT); 4252 MNT_KERN_FLAG(MNTK_SUSPEND); 4253 MNT_KERN_FLAG(MNTK_SUSPEND2); 4254 MNT_KERN_FLAG(MNTK_SUSPENDED); 4255 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4256 MNT_KERN_FLAG(MNTK_NOKNOTE); 4257 #undef MNT_KERN_FLAG 4258 if (flags != 0) { 4259 if (buf[0] != '\0') 4260 strlcat(buf, ", ", sizeof(buf)); 4261 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4262 "0x%08x", flags); 4263 } 4264 db_printf(" mnt_kern_flag = %s\n", buf); 4265 4266 db_printf(" mnt_opt = "); 4267 opt = TAILQ_FIRST(mp->mnt_opt); 4268 if (opt != NULL) { 4269 db_printf("%s", opt->name); 4270 opt = TAILQ_NEXT(opt, link); 4271 while (opt != NULL) { 4272 db_printf(", %s", opt->name); 4273 opt = TAILQ_NEXT(opt, link); 4274 } 4275 } 4276 db_printf("\n"); 4277 4278 sp = &mp->mnt_stat; 4279 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4280 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4281 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4282 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4283 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4284 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4285 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4286 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4287 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4288 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4289 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4290 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4291 4292 db_printf(" mnt_cred = { uid=%u ruid=%u", 4293 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4294 if (jailed(mp->mnt_cred)) 4295 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4296 db_printf(" }\n"); 4297 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4298 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4299 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4300 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4301 db_printf(" mnt_lazyvnodelistsize = %d\n", 4302 mp->mnt_lazyvnodelistsize); 4303 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4304 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4305 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4306 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4307 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4308 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4309 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4310 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4311 db_printf(" mnt_secondary_accwrites = %d\n", 4312 mp->mnt_secondary_accwrites); 4313 db_printf(" mnt_gjprovider = %s\n", 4314 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4315 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4316 4317 db_printf("\n\nList of active vnodes\n"); 4318 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4319 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4320 vn_printf(vp, "vnode "); 4321 if (db_pager_quit) 4322 break; 4323 } 4324 } 4325 db_printf("\n\nList of inactive vnodes\n"); 4326 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4327 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4328 vn_printf(vp, "vnode "); 4329 if (db_pager_quit) 4330 break; 4331 } 4332 } 4333 } 4334 #endif /* DDB */ 4335 4336 /* 4337 * Fill in a struct xvfsconf based on a struct vfsconf. 4338 */ 4339 static int 4340 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4341 { 4342 struct xvfsconf xvfsp; 4343 4344 bzero(&xvfsp, sizeof(xvfsp)); 4345 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4346 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4347 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4348 xvfsp.vfc_flags = vfsp->vfc_flags; 4349 /* 4350 * These are unused in userland, we keep them 4351 * to not break binary compatibility. 4352 */ 4353 xvfsp.vfc_vfsops = NULL; 4354 xvfsp.vfc_next = NULL; 4355 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4356 } 4357 4358 #ifdef COMPAT_FREEBSD32 4359 struct xvfsconf32 { 4360 uint32_t vfc_vfsops; 4361 char vfc_name[MFSNAMELEN]; 4362 int32_t vfc_typenum; 4363 int32_t vfc_refcount; 4364 int32_t vfc_flags; 4365 uint32_t vfc_next; 4366 }; 4367 4368 static int 4369 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4370 { 4371 struct xvfsconf32 xvfsp; 4372 4373 bzero(&xvfsp, sizeof(xvfsp)); 4374 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4375 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4376 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4377 xvfsp.vfc_flags = vfsp->vfc_flags; 4378 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4379 } 4380 #endif 4381 4382 /* 4383 * Top level filesystem related information gathering. 4384 */ 4385 static int 4386 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4387 { 4388 struct vfsconf *vfsp; 4389 int error; 4390 4391 error = 0; 4392 vfsconf_slock(); 4393 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4394 #ifdef COMPAT_FREEBSD32 4395 if (req->flags & SCTL_MASK32) 4396 error = vfsconf2x32(req, vfsp); 4397 else 4398 #endif 4399 error = vfsconf2x(req, vfsp); 4400 if (error) 4401 break; 4402 } 4403 vfsconf_sunlock(); 4404 return (error); 4405 } 4406 4407 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4408 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4409 "S,xvfsconf", "List of all configured filesystems"); 4410 4411 #ifndef BURN_BRIDGES 4412 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4413 4414 static int 4415 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4416 { 4417 int *name = (int *)arg1 - 1; /* XXX */ 4418 u_int namelen = arg2 + 1; /* XXX */ 4419 struct vfsconf *vfsp; 4420 4421 log(LOG_WARNING, "userland calling deprecated sysctl, " 4422 "please rebuild world\n"); 4423 4424 #if 1 || defined(COMPAT_PRELITE2) 4425 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4426 if (namelen == 1) 4427 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4428 #endif 4429 4430 switch (name[1]) { 4431 case VFS_MAXTYPENUM: 4432 if (namelen != 2) 4433 return (ENOTDIR); 4434 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4435 case VFS_CONF: 4436 if (namelen != 3) 4437 return (ENOTDIR); /* overloaded */ 4438 vfsconf_slock(); 4439 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4440 if (vfsp->vfc_typenum == name[2]) 4441 break; 4442 } 4443 vfsconf_sunlock(); 4444 if (vfsp == NULL) 4445 return (EOPNOTSUPP); 4446 #ifdef COMPAT_FREEBSD32 4447 if (req->flags & SCTL_MASK32) 4448 return (vfsconf2x32(req, vfsp)); 4449 else 4450 #endif 4451 return (vfsconf2x(req, vfsp)); 4452 } 4453 return (EOPNOTSUPP); 4454 } 4455 4456 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4457 CTLFLAG_MPSAFE, vfs_sysctl, 4458 "Generic filesystem"); 4459 4460 #if 1 || defined(COMPAT_PRELITE2) 4461 4462 static int 4463 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4464 { 4465 int error; 4466 struct vfsconf *vfsp; 4467 struct ovfsconf ovfs; 4468 4469 vfsconf_slock(); 4470 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4471 bzero(&ovfs, sizeof(ovfs)); 4472 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4473 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4474 ovfs.vfc_index = vfsp->vfc_typenum; 4475 ovfs.vfc_refcount = vfsp->vfc_refcount; 4476 ovfs.vfc_flags = vfsp->vfc_flags; 4477 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4478 if (error != 0) { 4479 vfsconf_sunlock(); 4480 return (error); 4481 } 4482 } 4483 vfsconf_sunlock(); 4484 return (0); 4485 } 4486 4487 #endif /* 1 || COMPAT_PRELITE2 */ 4488 #endif /* !BURN_BRIDGES */ 4489 4490 #define KINFO_VNODESLOP 10 4491 #ifdef notyet 4492 /* 4493 * Dump vnode list (via sysctl). 4494 */ 4495 /* ARGSUSED */ 4496 static int 4497 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4498 { 4499 struct xvnode *xvn; 4500 struct mount *mp; 4501 struct vnode *vp; 4502 int error, len, n; 4503 4504 /* 4505 * Stale numvnodes access is not fatal here. 4506 */ 4507 req->lock = 0; 4508 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4509 if (!req->oldptr) 4510 /* Make an estimate */ 4511 return (SYSCTL_OUT(req, 0, len)); 4512 4513 error = sysctl_wire_old_buffer(req, 0); 4514 if (error != 0) 4515 return (error); 4516 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4517 n = 0; 4518 mtx_lock(&mountlist_mtx); 4519 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4520 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4521 continue; 4522 MNT_ILOCK(mp); 4523 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4524 if (n == len) 4525 break; 4526 vref(vp); 4527 xvn[n].xv_size = sizeof *xvn; 4528 xvn[n].xv_vnode = vp; 4529 xvn[n].xv_id = 0; /* XXX compat */ 4530 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4531 XV_COPY(usecount); 4532 XV_COPY(writecount); 4533 XV_COPY(holdcnt); 4534 XV_COPY(mount); 4535 XV_COPY(numoutput); 4536 XV_COPY(type); 4537 #undef XV_COPY 4538 xvn[n].xv_flag = vp->v_vflag; 4539 4540 switch (vp->v_type) { 4541 case VREG: 4542 case VDIR: 4543 case VLNK: 4544 break; 4545 case VBLK: 4546 case VCHR: 4547 if (vp->v_rdev == NULL) { 4548 vrele(vp); 4549 continue; 4550 } 4551 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4552 break; 4553 case VSOCK: 4554 xvn[n].xv_socket = vp->v_socket; 4555 break; 4556 case VFIFO: 4557 xvn[n].xv_fifo = vp->v_fifoinfo; 4558 break; 4559 case VNON: 4560 case VBAD: 4561 default: 4562 /* shouldn't happen? */ 4563 vrele(vp); 4564 continue; 4565 } 4566 vrele(vp); 4567 ++n; 4568 } 4569 MNT_IUNLOCK(mp); 4570 mtx_lock(&mountlist_mtx); 4571 vfs_unbusy(mp); 4572 if (n == len) 4573 break; 4574 } 4575 mtx_unlock(&mountlist_mtx); 4576 4577 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4578 free(xvn, M_TEMP); 4579 return (error); 4580 } 4581 4582 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4583 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4584 ""); 4585 #endif 4586 4587 static void 4588 unmount_or_warn(struct mount *mp) 4589 { 4590 int error; 4591 4592 error = dounmount(mp, MNT_FORCE, curthread); 4593 if (error != 0) { 4594 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4595 if (error == EBUSY) 4596 printf("BUSY)\n"); 4597 else 4598 printf("%d)\n", error); 4599 } 4600 } 4601 4602 /* 4603 * Unmount all filesystems. The list is traversed in reverse order 4604 * of mounting to avoid dependencies. 4605 */ 4606 void 4607 vfs_unmountall(void) 4608 { 4609 struct mount *mp, *tmp; 4610 4611 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4612 4613 /* 4614 * Since this only runs when rebooting, it is not interlocked. 4615 */ 4616 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4617 vfs_ref(mp); 4618 4619 /* 4620 * Forcibly unmounting "/dev" before "/" would prevent clean 4621 * unmount of the latter. 4622 */ 4623 if (mp == rootdevmp) 4624 continue; 4625 4626 unmount_or_warn(mp); 4627 } 4628 4629 if (rootdevmp != NULL) 4630 unmount_or_warn(rootdevmp); 4631 } 4632 4633 static void 4634 vfs_deferred_inactive(struct vnode *vp, int lkflags) 4635 { 4636 4637 ASSERT_VI_LOCKED(vp, __func__); 4638 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, ("VI_DEFINACT still set")); 4639 if ((vp->v_iflag & VI_OWEINACT) == 0) { 4640 vdropl(vp); 4641 return; 4642 } 4643 if (vn_lock(vp, lkflags) == 0) { 4644 VI_LOCK(vp); 4645 vinactive(vp); 4646 VOP_UNLOCK(vp); 4647 vdropl(vp); 4648 return; 4649 } 4650 vdefer_inactive_unlocked(vp); 4651 } 4652 4653 static int 4654 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 4655 { 4656 4657 return (vp->v_iflag & VI_DEFINACT); 4658 } 4659 4660 static void __noinline 4661 vfs_periodic_inactive(struct mount *mp, int flags) 4662 { 4663 struct vnode *vp, *mvp; 4664 int lkflags; 4665 4666 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4667 if (flags != MNT_WAIT) 4668 lkflags |= LK_NOWAIT; 4669 4670 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 4671 if ((vp->v_iflag & VI_DEFINACT) == 0) { 4672 VI_UNLOCK(vp); 4673 continue; 4674 } 4675 vp->v_iflag &= ~VI_DEFINACT; 4676 vfs_deferred_inactive(vp, lkflags); 4677 } 4678 } 4679 4680 static inline bool 4681 vfs_want_msync(struct vnode *vp) 4682 { 4683 struct vm_object *obj; 4684 4685 /* 4686 * This test may be performed without any locks held. 4687 * We rely on vm_object's type stability. 4688 */ 4689 if (vp->v_vflag & VV_NOSYNC) 4690 return (false); 4691 obj = vp->v_object; 4692 return (obj != NULL && vm_object_mightbedirty(obj)); 4693 } 4694 4695 static int 4696 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 4697 { 4698 4699 if (vp->v_vflag & VV_NOSYNC) 4700 return (false); 4701 if (vp->v_iflag & VI_DEFINACT) 4702 return (true); 4703 return (vfs_want_msync(vp)); 4704 } 4705 4706 static void __noinline 4707 vfs_periodic_msync_inactive(struct mount *mp, int flags) 4708 { 4709 struct vnode *vp, *mvp; 4710 struct vm_object *obj; 4711 struct thread *td; 4712 int lkflags, objflags; 4713 bool seen_defer; 4714 4715 td = curthread; 4716 4717 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4718 if (flags != MNT_WAIT) { 4719 lkflags |= LK_NOWAIT; 4720 objflags = OBJPC_NOSYNC; 4721 } else { 4722 objflags = OBJPC_SYNC; 4723 } 4724 4725 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 4726 seen_defer = false; 4727 if (vp->v_iflag & VI_DEFINACT) { 4728 vp->v_iflag &= ~VI_DEFINACT; 4729 seen_defer = true; 4730 } 4731 if (!vfs_want_msync(vp)) { 4732 if (seen_defer) 4733 vfs_deferred_inactive(vp, lkflags); 4734 else 4735 VI_UNLOCK(vp); 4736 continue; 4737 } 4738 if (vget(vp, lkflags, td) == 0) { 4739 obj = vp->v_object; 4740 if (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0) { 4741 VM_OBJECT_WLOCK(obj); 4742 vm_object_page_clean(obj, 0, 0, objflags); 4743 VM_OBJECT_WUNLOCK(obj); 4744 } 4745 vput(vp); 4746 if (seen_defer) 4747 vdrop(vp); 4748 } else { 4749 if (seen_defer) 4750 vdefer_inactive_unlocked(vp); 4751 } 4752 } 4753 } 4754 4755 void 4756 vfs_periodic(struct mount *mp, int flags) 4757 { 4758 4759 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4760 4761 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4762 vfs_periodic_inactive(mp, flags); 4763 else 4764 vfs_periodic_msync_inactive(mp, flags); 4765 } 4766 4767 static void 4768 destroy_vpollinfo_free(struct vpollinfo *vi) 4769 { 4770 4771 knlist_destroy(&vi->vpi_selinfo.si_note); 4772 mtx_destroy(&vi->vpi_lock); 4773 uma_zfree(vnodepoll_zone, vi); 4774 } 4775 4776 static void 4777 destroy_vpollinfo(struct vpollinfo *vi) 4778 { 4779 4780 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4781 seldrain(&vi->vpi_selinfo); 4782 destroy_vpollinfo_free(vi); 4783 } 4784 4785 /* 4786 * Initialize per-vnode helper structure to hold poll-related state. 4787 */ 4788 void 4789 v_addpollinfo(struct vnode *vp) 4790 { 4791 struct vpollinfo *vi; 4792 4793 if (vp->v_pollinfo != NULL) 4794 return; 4795 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4796 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4797 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4798 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4799 VI_LOCK(vp); 4800 if (vp->v_pollinfo != NULL) { 4801 VI_UNLOCK(vp); 4802 destroy_vpollinfo_free(vi); 4803 return; 4804 } 4805 vp->v_pollinfo = vi; 4806 VI_UNLOCK(vp); 4807 } 4808 4809 /* 4810 * Record a process's interest in events which might happen to 4811 * a vnode. Because poll uses the historic select-style interface 4812 * internally, this routine serves as both the ``check for any 4813 * pending events'' and the ``record my interest in future events'' 4814 * functions. (These are done together, while the lock is held, 4815 * to avoid race conditions.) 4816 */ 4817 int 4818 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4819 { 4820 4821 v_addpollinfo(vp); 4822 mtx_lock(&vp->v_pollinfo->vpi_lock); 4823 if (vp->v_pollinfo->vpi_revents & events) { 4824 /* 4825 * This leaves events we are not interested 4826 * in available for the other process which 4827 * which presumably had requested them 4828 * (otherwise they would never have been 4829 * recorded). 4830 */ 4831 events &= vp->v_pollinfo->vpi_revents; 4832 vp->v_pollinfo->vpi_revents &= ~events; 4833 4834 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4835 return (events); 4836 } 4837 vp->v_pollinfo->vpi_events |= events; 4838 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4839 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4840 return (0); 4841 } 4842 4843 /* 4844 * Routine to create and manage a filesystem syncer vnode. 4845 */ 4846 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4847 static int sync_fsync(struct vop_fsync_args *); 4848 static int sync_inactive(struct vop_inactive_args *); 4849 static int sync_reclaim(struct vop_reclaim_args *); 4850 4851 static struct vop_vector sync_vnodeops = { 4852 .vop_bypass = VOP_EOPNOTSUPP, 4853 .vop_close = sync_close, /* close */ 4854 .vop_fsync = sync_fsync, /* fsync */ 4855 .vop_inactive = sync_inactive, /* inactive */ 4856 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 4857 .vop_reclaim = sync_reclaim, /* reclaim */ 4858 .vop_lock1 = vop_stdlock, /* lock */ 4859 .vop_unlock = vop_stdunlock, /* unlock */ 4860 .vop_islocked = vop_stdislocked, /* islocked */ 4861 }; 4862 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 4863 4864 /* 4865 * Create a new filesystem syncer vnode for the specified mount point. 4866 */ 4867 void 4868 vfs_allocate_syncvnode(struct mount *mp) 4869 { 4870 struct vnode *vp; 4871 struct bufobj *bo; 4872 static long start, incr, next; 4873 int error; 4874 4875 /* Allocate a new vnode */ 4876 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4877 if (error != 0) 4878 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4879 vp->v_type = VNON; 4880 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4881 vp->v_vflag |= VV_FORCEINSMQ; 4882 error = insmntque(vp, mp); 4883 if (error != 0) 4884 panic("vfs_allocate_syncvnode: insmntque() failed"); 4885 vp->v_vflag &= ~VV_FORCEINSMQ; 4886 VOP_UNLOCK(vp); 4887 /* 4888 * Place the vnode onto the syncer worklist. We attempt to 4889 * scatter them about on the list so that they will go off 4890 * at evenly distributed times even if all the filesystems 4891 * are mounted at once. 4892 */ 4893 next += incr; 4894 if (next == 0 || next > syncer_maxdelay) { 4895 start /= 2; 4896 incr /= 2; 4897 if (start == 0) { 4898 start = syncer_maxdelay / 2; 4899 incr = syncer_maxdelay; 4900 } 4901 next = start; 4902 } 4903 bo = &vp->v_bufobj; 4904 BO_LOCK(bo); 4905 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4906 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4907 mtx_lock(&sync_mtx); 4908 sync_vnode_count++; 4909 if (mp->mnt_syncer == NULL) { 4910 mp->mnt_syncer = vp; 4911 vp = NULL; 4912 } 4913 mtx_unlock(&sync_mtx); 4914 BO_UNLOCK(bo); 4915 if (vp != NULL) { 4916 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4917 vgone(vp); 4918 vput(vp); 4919 } 4920 } 4921 4922 void 4923 vfs_deallocate_syncvnode(struct mount *mp) 4924 { 4925 struct vnode *vp; 4926 4927 mtx_lock(&sync_mtx); 4928 vp = mp->mnt_syncer; 4929 if (vp != NULL) 4930 mp->mnt_syncer = NULL; 4931 mtx_unlock(&sync_mtx); 4932 if (vp != NULL) 4933 vrele(vp); 4934 } 4935 4936 /* 4937 * Do a lazy sync of the filesystem. 4938 */ 4939 static int 4940 sync_fsync(struct vop_fsync_args *ap) 4941 { 4942 struct vnode *syncvp = ap->a_vp; 4943 struct mount *mp = syncvp->v_mount; 4944 int error, save; 4945 struct bufobj *bo; 4946 4947 /* 4948 * We only need to do something if this is a lazy evaluation. 4949 */ 4950 if (ap->a_waitfor != MNT_LAZY) 4951 return (0); 4952 4953 /* 4954 * Move ourselves to the back of the sync list. 4955 */ 4956 bo = &syncvp->v_bufobj; 4957 BO_LOCK(bo); 4958 vn_syncer_add_to_worklist(bo, syncdelay); 4959 BO_UNLOCK(bo); 4960 4961 /* 4962 * Walk the list of vnodes pushing all that are dirty and 4963 * not already on the sync list. 4964 */ 4965 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4966 return (0); 4967 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4968 vfs_unbusy(mp); 4969 return (0); 4970 } 4971 save = curthread_pflags_set(TDP_SYNCIO); 4972 /* 4973 * The filesystem at hand may be idle with free vnodes stored in the 4974 * batch. Return them instead of letting them stay there indefinitely. 4975 */ 4976 vfs_periodic(mp, MNT_NOWAIT); 4977 error = VFS_SYNC(mp, MNT_LAZY); 4978 curthread_pflags_restore(save); 4979 vn_finished_write(mp); 4980 vfs_unbusy(mp); 4981 return (error); 4982 } 4983 4984 /* 4985 * The syncer vnode is no referenced. 4986 */ 4987 static int 4988 sync_inactive(struct vop_inactive_args *ap) 4989 { 4990 4991 vgone(ap->a_vp); 4992 return (0); 4993 } 4994 4995 /* 4996 * The syncer vnode is no longer needed and is being decommissioned. 4997 * 4998 * Modifications to the worklist must be protected by sync_mtx. 4999 */ 5000 static int 5001 sync_reclaim(struct vop_reclaim_args *ap) 5002 { 5003 struct vnode *vp = ap->a_vp; 5004 struct bufobj *bo; 5005 5006 bo = &vp->v_bufobj; 5007 BO_LOCK(bo); 5008 mtx_lock(&sync_mtx); 5009 if (vp->v_mount->mnt_syncer == vp) 5010 vp->v_mount->mnt_syncer = NULL; 5011 if (bo->bo_flag & BO_ONWORKLST) { 5012 LIST_REMOVE(bo, bo_synclist); 5013 syncer_worklist_len--; 5014 sync_vnode_count--; 5015 bo->bo_flag &= ~BO_ONWORKLST; 5016 } 5017 mtx_unlock(&sync_mtx); 5018 BO_UNLOCK(bo); 5019 5020 return (0); 5021 } 5022 5023 int 5024 vn_need_pageq_flush(struct vnode *vp) 5025 { 5026 struct vm_object *obj; 5027 int need; 5028 5029 MPASS(mtx_owned(VI_MTX(vp))); 5030 need = 0; 5031 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5032 vm_object_mightbedirty(obj)) 5033 need = 1; 5034 return (need); 5035 } 5036 5037 /* 5038 * Check if vnode represents a disk device 5039 */ 5040 int 5041 vn_isdisk(struct vnode *vp, int *errp) 5042 { 5043 int error; 5044 5045 if (vp->v_type != VCHR) { 5046 error = ENOTBLK; 5047 goto out; 5048 } 5049 error = 0; 5050 dev_lock(); 5051 if (vp->v_rdev == NULL) 5052 error = ENXIO; 5053 else if (vp->v_rdev->si_devsw == NULL) 5054 error = ENXIO; 5055 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5056 error = ENOTBLK; 5057 dev_unlock(); 5058 out: 5059 if (errp != NULL) 5060 *errp = error; 5061 return (error == 0); 5062 } 5063 5064 /* 5065 * Common filesystem object access control check routine. Accepts a 5066 * vnode's type, "mode", uid and gid, requested access mode, credentials, 5067 * and optional call-by-reference privused argument allowing vaccess() 5068 * to indicate to the caller whether privilege was used to satisfy the 5069 * request (obsoleted). Returns 0 on success, or an errno on failure. 5070 */ 5071 int 5072 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5073 accmode_t accmode, struct ucred *cred, int *privused) 5074 { 5075 accmode_t dac_granted; 5076 accmode_t priv_granted; 5077 5078 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5079 ("invalid bit in accmode")); 5080 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5081 ("VAPPEND without VWRITE")); 5082 5083 /* 5084 * Look for a normal, non-privileged way to access the file/directory 5085 * as requested. If it exists, go with that. 5086 */ 5087 5088 if (privused != NULL) 5089 *privused = 0; 5090 5091 dac_granted = 0; 5092 5093 /* Check the owner. */ 5094 if (cred->cr_uid == file_uid) { 5095 dac_granted |= VADMIN; 5096 if (file_mode & S_IXUSR) 5097 dac_granted |= VEXEC; 5098 if (file_mode & S_IRUSR) 5099 dac_granted |= VREAD; 5100 if (file_mode & S_IWUSR) 5101 dac_granted |= (VWRITE | VAPPEND); 5102 5103 if ((accmode & dac_granted) == accmode) 5104 return (0); 5105 5106 goto privcheck; 5107 } 5108 5109 /* Otherwise, check the groups (first match) */ 5110 if (groupmember(file_gid, cred)) { 5111 if (file_mode & S_IXGRP) 5112 dac_granted |= VEXEC; 5113 if (file_mode & S_IRGRP) 5114 dac_granted |= VREAD; 5115 if (file_mode & S_IWGRP) 5116 dac_granted |= (VWRITE | VAPPEND); 5117 5118 if ((accmode & dac_granted) == accmode) 5119 return (0); 5120 5121 goto privcheck; 5122 } 5123 5124 /* Otherwise, check everyone else. */ 5125 if (file_mode & S_IXOTH) 5126 dac_granted |= VEXEC; 5127 if (file_mode & S_IROTH) 5128 dac_granted |= VREAD; 5129 if (file_mode & S_IWOTH) 5130 dac_granted |= (VWRITE | VAPPEND); 5131 if ((accmode & dac_granted) == accmode) 5132 return (0); 5133 5134 privcheck: 5135 /* 5136 * Build a privilege mask to determine if the set of privileges 5137 * satisfies the requirements when combined with the granted mask 5138 * from above. For each privilege, if the privilege is required, 5139 * bitwise or the request type onto the priv_granted mask. 5140 */ 5141 priv_granted = 0; 5142 5143 if (type == VDIR) { 5144 /* 5145 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5146 * requests, instead of PRIV_VFS_EXEC. 5147 */ 5148 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5149 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5150 priv_granted |= VEXEC; 5151 } else { 5152 /* 5153 * Ensure that at least one execute bit is on. Otherwise, 5154 * a privileged user will always succeed, and we don't want 5155 * this to happen unless the file really is executable. 5156 */ 5157 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5158 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5159 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5160 priv_granted |= VEXEC; 5161 } 5162 5163 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5164 !priv_check_cred(cred, PRIV_VFS_READ)) 5165 priv_granted |= VREAD; 5166 5167 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5168 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5169 priv_granted |= (VWRITE | VAPPEND); 5170 5171 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5172 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5173 priv_granted |= VADMIN; 5174 5175 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5176 /* XXX audit: privilege used */ 5177 if (privused != NULL) 5178 *privused = 1; 5179 return (0); 5180 } 5181 5182 return ((accmode & VADMIN) ? EPERM : EACCES); 5183 } 5184 5185 /* 5186 * Credential check based on process requesting service, and per-attribute 5187 * permissions. 5188 */ 5189 int 5190 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5191 struct thread *td, accmode_t accmode) 5192 { 5193 5194 /* 5195 * Kernel-invoked always succeeds. 5196 */ 5197 if (cred == NOCRED) 5198 return (0); 5199 5200 /* 5201 * Do not allow privileged processes in jail to directly manipulate 5202 * system attributes. 5203 */ 5204 switch (attrnamespace) { 5205 case EXTATTR_NAMESPACE_SYSTEM: 5206 /* Potentially should be: return (EPERM); */ 5207 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5208 case EXTATTR_NAMESPACE_USER: 5209 return (VOP_ACCESS(vp, accmode, cred, td)); 5210 default: 5211 return (EPERM); 5212 } 5213 } 5214 5215 #ifdef DEBUG_VFS_LOCKS 5216 /* 5217 * This only exists to suppress warnings from unlocked specfs accesses. It is 5218 * no longer ok to have an unlocked VFS. 5219 */ 5220 #define IGNORE_LOCK(vp) (KERNEL_PANICKED() || (vp) == NULL || \ 5221 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 5222 5223 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5224 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5225 "Drop into debugger on lock violation"); 5226 5227 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5228 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5229 0, "Check for interlock across VOPs"); 5230 5231 int vfs_badlock_print = 1; /* Print lock violations. */ 5232 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5233 0, "Print lock violations"); 5234 5235 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5236 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5237 0, "Print vnode details on lock violations"); 5238 5239 #ifdef KDB 5240 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5241 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5242 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5243 #endif 5244 5245 static void 5246 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5247 { 5248 5249 #ifdef KDB 5250 if (vfs_badlock_backtrace) 5251 kdb_backtrace(); 5252 #endif 5253 if (vfs_badlock_vnode) 5254 vn_printf(vp, "vnode "); 5255 if (vfs_badlock_print) 5256 printf("%s: %p %s\n", str, (void *)vp, msg); 5257 if (vfs_badlock_ddb) 5258 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5259 } 5260 5261 void 5262 assert_vi_locked(struct vnode *vp, const char *str) 5263 { 5264 5265 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5266 vfs_badlock("interlock is not locked but should be", str, vp); 5267 } 5268 5269 void 5270 assert_vi_unlocked(struct vnode *vp, const char *str) 5271 { 5272 5273 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5274 vfs_badlock("interlock is locked but should not be", str, vp); 5275 } 5276 5277 void 5278 assert_vop_locked(struct vnode *vp, const char *str) 5279 { 5280 int locked; 5281 5282 if (!IGNORE_LOCK(vp)) { 5283 locked = VOP_ISLOCKED(vp); 5284 if (locked == 0 || locked == LK_EXCLOTHER) 5285 vfs_badlock("is not locked but should be", str, vp); 5286 } 5287 } 5288 5289 void 5290 assert_vop_unlocked(struct vnode *vp, const char *str) 5291 { 5292 5293 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5294 vfs_badlock("is locked but should not be", str, vp); 5295 } 5296 5297 void 5298 assert_vop_elocked(struct vnode *vp, const char *str) 5299 { 5300 5301 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5302 vfs_badlock("is not exclusive locked but should be", str, vp); 5303 } 5304 #endif /* DEBUG_VFS_LOCKS */ 5305 5306 void 5307 vop_rename_fail(struct vop_rename_args *ap) 5308 { 5309 5310 if (ap->a_tvp != NULL) 5311 vput(ap->a_tvp); 5312 if (ap->a_tdvp == ap->a_tvp) 5313 vrele(ap->a_tdvp); 5314 else 5315 vput(ap->a_tdvp); 5316 vrele(ap->a_fdvp); 5317 vrele(ap->a_fvp); 5318 } 5319 5320 void 5321 vop_rename_pre(void *ap) 5322 { 5323 struct vop_rename_args *a = ap; 5324 5325 #ifdef DEBUG_VFS_LOCKS 5326 if (a->a_tvp) 5327 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5328 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5329 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5330 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5331 5332 /* Check the source (from). */ 5333 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5334 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5335 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5336 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5337 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5338 5339 /* Check the target. */ 5340 if (a->a_tvp) 5341 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5342 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5343 #endif 5344 if (a->a_tdvp != a->a_fdvp) 5345 vhold(a->a_fdvp); 5346 if (a->a_tvp != a->a_fvp) 5347 vhold(a->a_fvp); 5348 vhold(a->a_tdvp); 5349 if (a->a_tvp) 5350 vhold(a->a_tvp); 5351 } 5352 5353 #ifdef DEBUG_VFS_LOCKS 5354 void 5355 vop_strategy_pre(void *ap) 5356 { 5357 struct vop_strategy_args *a; 5358 struct buf *bp; 5359 5360 a = ap; 5361 bp = a->a_bp; 5362 5363 /* 5364 * Cluster ops lock their component buffers but not the IO container. 5365 */ 5366 if ((bp->b_flags & B_CLUSTER) != 0) 5367 return; 5368 5369 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5370 if (vfs_badlock_print) 5371 printf( 5372 "VOP_STRATEGY: bp is not locked but should be\n"); 5373 if (vfs_badlock_ddb) 5374 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5375 } 5376 } 5377 5378 void 5379 vop_lock_pre(void *ap) 5380 { 5381 struct vop_lock1_args *a = ap; 5382 5383 if ((a->a_flags & LK_INTERLOCK) == 0) 5384 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5385 else 5386 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5387 } 5388 5389 void 5390 vop_lock_post(void *ap, int rc) 5391 { 5392 struct vop_lock1_args *a = ap; 5393 5394 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5395 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5396 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5397 } 5398 5399 void 5400 vop_unlock_pre(void *ap) 5401 { 5402 struct vop_unlock_args *a = ap; 5403 5404 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5405 } 5406 5407 void 5408 vop_need_inactive_pre(void *ap) 5409 { 5410 struct vop_need_inactive_args *a = ap; 5411 5412 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5413 } 5414 5415 void 5416 vop_need_inactive_post(void *ap, int rc) 5417 { 5418 struct vop_need_inactive_args *a = ap; 5419 5420 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5421 } 5422 #endif 5423 5424 void 5425 vop_create_post(void *ap, int rc) 5426 { 5427 struct vop_create_args *a = ap; 5428 5429 if (!rc) 5430 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5431 } 5432 5433 void 5434 vop_deleteextattr_post(void *ap, int rc) 5435 { 5436 struct vop_deleteextattr_args *a = ap; 5437 5438 if (!rc) 5439 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5440 } 5441 5442 void 5443 vop_link_post(void *ap, int rc) 5444 { 5445 struct vop_link_args *a = ap; 5446 5447 if (!rc) { 5448 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 5449 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 5450 } 5451 } 5452 5453 void 5454 vop_mkdir_post(void *ap, int rc) 5455 { 5456 struct vop_mkdir_args *a = ap; 5457 5458 if (!rc) 5459 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5460 } 5461 5462 void 5463 vop_mknod_post(void *ap, int rc) 5464 { 5465 struct vop_mknod_args *a = ap; 5466 5467 if (!rc) 5468 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5469 } 5470 5471 void 5472 vop_reclaim_post(void *ap, int rc) 5473 { 5474 struct vop_reclaim_args *a = ap; 5475 5476 if (!rc) 5477 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 5478 } 5479 5480 void 5481 vop_remove_post(void *ap, int rc) 5482 { 5483 struct vop_remove_args *a = ap; 5484 5485 if (!rc) { 5486 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5487 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5488 } 5489 } 5490 5491 void 5492 vop_rename_post(void *ap, int rc) 5493 { 5494 struct vop_rename_args *a = ap; 5495 long hint; 5496 5497 if (!rc) { 5498 hint = NOTE_WRITE; 5499 if (a->a_fdvp == a->a_tdvp) { 5500 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5501 hint |= NOTE_LINK; 5502 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5503 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5504 } else { 5505 hint |= NOTE_EXTEND; 5506 if (a->a_fvp->v_type == VDIR) 5507 hint |= NOTE_LINK; 5508 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5509 5510 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5511 a->a_tvp->v_type == VDIR) 5512 hint &= ~NOTE_LINK; 5513 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5514 } 5515 5516 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5517 if (a->a_tvp) 5518 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5519 } 5520 if (a->a_tdvp != a->a_fdvp) 5521 vdrop(a->a_fdvp); 5522 if (a->a_tvp != a->a_fvp) 5523 vdrop(a->a_fvp); 5524 vdrop(a->a_tdvp); 5525 if (a->a_tvp) 5526 vdrop(a->a_tvp); 5527 } 5528 5529 void 5530 vop_rmdir_post(void *ap, int rc) 5531 { 5532 struct vop_rmdir_args *a = ap; 5533 5534 if (!rc) { 5535 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5536 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5537 } 5538 } 5539 5540 void 5541 vop_setattr_post(void *ap, int rc) 5542 { 5543 struct vop_setattr_args *a = ap; 5544 5545 if (!rc) 5546 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5547 } 5548 5549 void 5550 vop_setextattr_post(void *ap, int rc) 5551 { 5552 struct vop_setextattr_args *a = ap; 5553 5554 if (!rc) 5555 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5556 } 5557 5558 void 5559 vop_symlink_post(void *ap, int rc) 5560 { 5561 struct vop_symlink_args *a = ap; 5562 5563 if (!rc) 5564 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5565 } 5566 5567 void 5568 vop_open_post(void *ap, int rc) 5569 { 5570 struct vop_open_args *a = ap; 5571 5572 if (!rc) 5573 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5574 } 5575 5576 void 5577 vop_close_post(void *ap, int rc) 5578 { 5579 struct vop_close_args *a = ap; 5580 5581 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5582 !VN_IS_DOOMED(a->a_vp))) { 5583 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5584 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5585 } 5586 } 5587 5588 void 5589 vop_read_post(void *ap, int rc) 5590 { 5591 struct vop_read_args *a = ap; 5592 5593 if (!rc) 5594 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5595 } 5596 5597 void 5598 vop_readdir_post(void *ap, int rc) 5599 { 5600 struct vop_readdir_args *a = ap; 5601 5602 if (!rc) 5603 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5604 } 5605 5606 static struct knlist fs_knlist; 5607 5608 static void 5609 vfs_event_init(void *arg) 5610 { 5611 knlist_init_mtx(&fs_knlist, NULL); 5612 } 5613 /* XXX - correct order? */ 5614 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5615 5616 void 5617 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5618 { 5619 5620 KNOTE_UNLOCKED(&fs_knlist, event); 5621 } 5622 5623 static int filt_fsattach(struct knote *kn); 5624 static void filt_fsdetach(struct knote *kn); 5625 static int filt_fsevent(struct knote *kn, long hint); 5626 5627 struct filterops fs_filtops = { 5628 .f_isfd = 0, 5629 .f_attach = filt_fsattach, 5630 .f_detach = filt_fsdetach, 5631 .f_event = filt_fsevent 5632 }; 5633 5634 static int 5635 filt_fsattach(struct knote *kn) 5636 { 5637 5638 kn->kn_flags |= EV_CLEAR; 5639 knlist_add(&fs_knlist, kn, 0); 5640 return (0); 5641 } 5642 5643 static void 5644 filt_fsdetach(struct knote *kn) 5645 { 5646 5647 knlist_remove(&fs_knlist, kn, 0); 5648 } 5649 5650 static int 5651 filt_fsevent(struct knote *kn, long hint) 5652 { 5653 5654 kn->kn_fflags |= hint; 5655 return (kn->kn_fflags != 0); 5656 } 5657 5658 static int 5659 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5660 { 5661 struct vfsidctl vc; 5662 int error; 5663 struct mount *mp; 5664 5665 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5666 if (error) 5667 return (error); 5668 if (vc.vc_vers != VFS_CTL_VERS1) 5669 return (EINVAL); 5670 mp = vfs_getvfs(&vc.vc_fsid); 5671 if (mp == NULL) 5672 return (ENOENT); 5673 /* ensure that a specific sysctl goes to the right filesystem. */ 5674 if (strcmp(vc.vc_fstypename, "*") != 0 && 5675 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5676 vfs_rel(mp); 5677 return (EINVAL); 5678 } 5679 VCTLTOREQ(&vc, req); 5680 error = VFS_SYSCTL(mp, vc.vc_op, req); 5681 vfs_rel(mp); 5682 return (error); 5683 } 5684 5685 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 5686 NULL, 0, sysctl_vfs_ctl, "", 5687 "Sysctl by fsid"); 5688 5689 /* 5690 * Function to initialize a va_filerev field sensibly. 5691 * XXX: Wouldn't a random number make a lot more sense ?? 5692 */ 5693 u_quad_t 5694 init_va_filerev(void) 5695 { 5696 struct bintime bt; 5697 5698 getbinuptime(&bt); 5699 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5700 } 5701 5702 static int filt_vfsread(struct knote *kn, long hint); 5703 static int filt_vfswrite(struct knote *kn, long hint); 5704 static int filt_vfsvnode(struct knote *kn, long hint); 5705 static void filt_vfsdetach(struct knote *kn); 5706 static struct filterops vfsread_filtops = { 5707 .f_isfd = 1, 5708 .f_detach = filt_vfsdetach, 5709 .f_event = filt_vfsread 5710 }; 5711 static struct filterops vfswrite_filtops = { 5712 .f_isfd = 1, 5713 .f_detach = filt_vfsdetach, 5714 .f_event = filt_vfswrite 5715 }; 5716 static struct filterops vfsvnode_filtops = { 5717 .f_isfd = 1, 5718 .f_detach = filt_vfsdetach, 5719 .f_event = filt_vfsvnode 5720 }; 5721 5722 static void 5723 vfs_knllock(void *arg) 5724 { 5725 struct vnode *vp = arg; 5726 5727 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5728 } 5729 5730 static void 5731 vfs_knlunlock(void *arg) 5732 { 5733 struct vnode *vp = arg; 5734 5735 VOP_UNLOCK(vp); 5736 } 5737 5738 static void 5739 vfs_knl_assert_locked(void *arg) 5740 { 5741 #ifdef DEBUG_VFS_LOCKS 5742 struct vnode *vp = arg; 5743 5744 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5745 #endif 5746 } 5747 5748 static void 5749 vfs_knl_assert_unlocked(void *arg) 5750 { 5751 #ifdef DEBUG_VFS_LOCKS 5752 struct vnode *vp = arg; 5753 5754 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5755 #endif 5756 } 5757 5758 int 5759 vfs_kqfilter(struct vop_kqfilter_args *ap) 5760 { 5761 struct vnode *vp = ap->a_vp; 5762 struct knote *kn = ap->a_kn; 5763 struct knlist *knl; 5764 5765 switch (kn->kn_filter) { 5766 case EVFILT_READ: 5767 kn->kn_fop = &vfsread_filtops; 5768 break; 5769 case EVFILT_WRITE: 5770 kn->kn_fop = &vfswrite_filtops; 5771 break; 5772 case EVFILT_VNODE: 5773 kn->kn_fop = &vfsvnode_filtops; 5774 break; 5775 default: 5776 return (EINVAL); 5777 } 5778 5779 kn->kn_hook = (caddr_t)vp; 5780 5781 v_addpollinfo(vp); 5782 if (vp->v_pollinfo == NULL) 5783 return (ENOMEM); 5784 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5785 vhold(vp); 5786 knlist_add(knl, kn, 0); 5787 5788 return (0); 5789 } 5790 5791 /* 5792 * Detach knote from vnode 5793 */ 5794 static void 5795 filt_vfsdetach(struct knote *kn) 5796 { 5797 struct vnode *vp = (struct vnode *)kn->kn_hook; 5798 5799 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5800 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5801 vdrop(vp); 5802 } 5803 5804 /*ARGSUSED*/ 5805 static int 5806 filt_vfsread(struct knote *kn, long hint) 5807 { 5808 struct vnode *vp = (struct vnode *)kn->kn_hook; 5809 struct vattr va; 5810 int res; 5811 5812 /* 5813 * filesystem is gone, so set the EOF flag and schedule 5814 * the knote for deletion. 5815 */ 5816 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5817 VI_LOCK(vp); 5818 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5819 VI_UNLOCK(vp); 5820 return (1); 5821 } 5822 5823 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5824 return (0); 5825 5826 VI_LOCK(vp); 5827 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5828 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5829 VI_UNLOCK(vp); 5830 return (res); 5831 } 5832 5833 /*ARGSUSED*/ 5834 static int 5835 filt_vfswrite(struct knote *kn, long hint) 5836 { 5837 struct vnode *vp = (struct vnode *)kn->kn_hook; 5838 5839 VI_LOCK(vp); 5840 5841 /* 5842 * filesystem is gone, so set the EOF flag and schedule 5843 * the knote for deletion. 5844 */ 5845 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5846 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5847 5848 kn->kn_data = 0; 5849 VI_UNLOCK(vp); 5850 return (1); 5851 } 5852 5853 static int 5854 filt_vfsvnode(struct knote *kn, long hint) 5855 { 5856 struct vnode *vp = (struct vnode *)kn->kn_hook; 5857 int res; 5858 5859 VI_LOCK(vp); 5860 if (kn->kn_sfflags & hint) 5861 kn->kn_fflags |= hint; 5862 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5863 kn->kn_flags |= EV_EOF; 5864 VI_UNLOCK(vp); 5865 return (1); 5866 } 5867 res = (kn->kn_fflags != 0); 5868 VI_UNLOCK(vp); 5869 return (res); 5870 } 5871 5872 /* 5873 * Returns whether the directory is empty or not. 5874 * If it is empty, the return value is 0; otherwise 5875 * the return value is an error value (which may 5876 * be ENOTEMPTY). 5877 */ 5878 int 5879 vfs_emptydir(struct vnode *vp) 5880 { 5881 struct uio uio; 5882 struct iovec iov; 5883 struct dirent *dirent, *dp, *endp; 5884 int error, eof; 5885 5886 error = 0; 5887 eof = 0; 5888 5889 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 5890 5891 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 5892 iov.iov_base = dirent; 5893 iov.iov_len = sizeof(struct dirent); 5894 5895 uio.uio_iov = &iov; 5896 uio.uio_iovcnt = 1; 5897 uio.uio_offset = 0; 5898 uio.uio_resid = sizeof(struct dirent); 5899 uio.uio_segflg = UIO_SYSSPACE; 5900 uio.uio_rw = UIO_READ; 5901 uio.uio_td = curthread; 5902 5903 while (eof == 0 && error == 0) { 5904 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 5905 NULL, NULL); 5906 if (error != 0) 5907 break; 5908 endp = (void *)((uint8_t *)dirent + 5909 sizeof(struct dirent) - uio.uio_resid); 5910 for (dp = dirent; dp < endp; 5911 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 5912 if (dp->d_type == DT_WHT) 5913 continue; 5914 if (dp->d_namlen == 0) 5915 continue; 5916 if (dp->d_type != DT_DIR && 5917 dp->d_type != DT_UNKNOWN) { 5918 error = ENOTEMPTY; 5919 break; 5920 } 5921 if (dp->d_namlen > 2) { 5922 error = ENOTEMPTY; 5923 break; 5924 } 5925 if (dp->d_namlen == 1 && 5926 dp->d_name[0] != '.') { 5927 error = ENOTEMPTY; 5928 break; 5929 } 5930 if (dp->d_namlen == 2 && 5931 dp->d_name[1] != '.') { 5932 error = ENOTEMPTY; 5933 break; 5934 } 5935 uio.uio_resid = sizeof(struct dirent); 5936 } 5937 } 5938 free(dirent, M_TEMP); 5939 return (error); 5940 } 5941 5942 int 5943 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5944 { 5945 int error; 5946 5947 if (dp->d_reclen > ap->a_uio->uio_resid) 5948 return (ENAMETOOLONG); 5949 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5950 if (error) { 5951 if (ap->a_ncookies != NULL) { 5952 if (ap->a_cookies != NULL) 5953 free(ap->a_cookies, M_TEMP); 5954 ap->a_cookies = NULL; 5955 *ap->a_ncookies = 0; 5956 } 5957 return (error); 5958 } 5959 if (ap->a_ncookies == NULL) 5960 return (0); 5961 5962 KASSERT(ap->a_cookies, 5963 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5964 5965 *ap->a_cookies = realloc(*ap->a_cookies, 5966 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5967 (*ap->a_cookies)[*ap->a_ncookies] = off; 5968 *ap->a_ncookies += 1; 5969 return (0); 5970 } 5971 5972 /* 5973 * The purpose of this routine is to remove granularity from accmode_t, 5974 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5975 * VADMIN and VAPPEND. 5976 * 5977 * If it returns 0, the caller is supposed to continue with the usual 5978 * access checks using 'accmode' as modified by this routine. If it 5979 * returns nonzero value, the caller is supposed to return that value 5980 * as errno. 5981 * 5982 * Note that after this routine runs, accmode may be zero. 5983 */ 5984 int 5985 vfs_unixify_accmode(accmode_t *accmode) 5986 { 5987 /* 5988 * There is no way to specify explicit "deny" rule using 5989 * file mode or POSIX.1e ACLs. 5990 */ 5991 if (*accmode & VEXPLICIT_DENY) { 5992 *accmode = 0; 5993 return (0); 5994 } 5995 5996 /* 5997 * None of these can be translated into usual access bits. 5998 * Also, the common case for NFSv4 ACLs is to not contain 5999 * either of these bits. Caller should check for VWRITE 6000 * on the containing directory instead. 6001 */ 6002 if (*accmode & (VDELETE_CHILD | VDELETE)) 6003 return (EPERM); 6004 6005 if (*accmode & VADMIN_PERMS) { 6006 *accmode &= ~VADMIN_PERMS; 6007 *accmode |= VADMIN; 6008 } 6009 6010 /* 6011 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6012 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6013 */ 6014 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6015 6016 return (0); 6017 } 6018 6019 /* 6020 * Clear out a doomed vnode (if any) and replace it with a new one as long 6021 * as the fs is not being unmounted. Return the root vnode to the caller. 6022 */ 6023 static int __noinline 6024 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6025 { 6026 struct vnode *vp; 6027 int error; 6028 6029 restart: 6030 if (mp->mnt_rootvnode != NULL) { 6031 MNT_ILOCK(mp); 6032 vp = mp->mnt_rootvnode; 6033 if (vp != NULL) { 6034 if (!VN_IS_DOOMED(vp)) { 6035 vrefact(vp); 6036 MNT_IUNLOCK(mp); 6037 error = vn_lock(vp, flags); 6038 if (error == 0) { 6039 *vpp = vp; 6040 return (0); 6041 } 6042 vrele(vp); 6043 goto restart; 6044 } 6045 /* 6046 * Clear the old one. 6047 */ 6048 mp->mnt_rootvnode = NULL; 6049 } 6050 MNT_IUNLOCK(mp); 6051 if (vp != NULL) { 6052 /* 6053 * Paired with a fence in vfs_op_thread_exit(). 6054 */ 6055 atomic_thread_fence_acq(); 6056 vfs_op_barrier_wait(mp); 6057 vrele(vp); 6058 } 6059 } 6060 error = VFS_CACHEDROOT(mp, flags, vpp); 6061 if (error != 0) 6062 return (error); 6063 if (mp->mnt_vfs_ops == 0) { 6064 MNT_ILOCK(mp); 6065 if (mp->mnt_vfs_ops != 0) { 6066 MNT_IUNLOCK(mp); 6067 return (0); 6068 } 6069 if (mp->mnt_rootvnode == NULL) { 6070 vrefact(*vpp); 6071 mp->mnt_rootvnode = *vpp; 6072 } else { 6073 if (mp->mnt_rootvnode != *vpp) { 6074 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6075 panic("%s: mismatch between vnode returned " 6076 " by VFS_CACHEDROOT and the one cached " 6077 " (%p != %p)", 6078 __func__, *vpp, mp->mnt_rootvnode); 6079 } 6080 } 6081 } 6082 MNT_IUNLOCK(mp); 6083 } 6084 return (0); 6085 } 6086 6087 int 6088 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6089 { 6090 struct vnode *vp; 6091 int error; 6092 6093 if (!vfs_op_thread_enter(mp)) 6094 return (vfs_cache_root_fallback(mp, flags, vpp)); 6095 vp = (struct vnode *)atomic_load_ptr(&mp->mnt_rootvnode); 6096 if (vp == NULL || VN_IS_DOOMED(vp)) { 6097 vfs_op_thread_exit(mp); 6098 return (vfs_cache_root_fallback(mp, flags, vpp)); 6099 } 6100 vrefact(vp); 6101 vfs_op_thread_exit(mp); 6102 error = vn_lock(vp, flags); 6103 if (error != 0) { 6104 vrele(vp); 6105 return (vfs_cache_root_fallback(mp, flags, vpp)); 6106 } 6107 *vpp = vp; 6108 return (0); 6109 } 6110 6111 struct vnode * 6112 vfs_cache_root_clear(struct mount *mp) 6113 { 6114 struct vnode *vp; 6115 6116 /* 6117 * ops > 0 guarantees there is nobody who can see this vnode 6118 */ 6119 MPASS(mp->mnt_vfs_ops > 0); 6120 vp = mp->mnt_rootvnode; 6121 mp->mnt_rootvnode = NULL; 6122 return (vp); 6123 } 6124 6125 void 6126 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6127 { 6128 6129 MPASS(mp->mnt_vfs_ops > 0); 6130 vrefact(vp); 6131 mp->mnt_rootvnode = vp; 6132 } 6133 6134 /* 6135 * These are helper functions for filesystems to traverse all 6136 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6137 * 6138 * This interface replaces MNT_VNODE_FOREACH. 6139 */ 6140 6141 struct vnode * 6142 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6143 { 6144 struct vnode *vp; 6145 6146 if (should_yield()) 6147 kern_yield(PRI_USER); 6148 MNT_ILOCK(mp); 6149 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6150 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6151 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6152 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6153 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6154 continue; 6155 VI_LOCK(vp); 6156 if (VN_IS_DOOMED(vp)) { 6157 VI_UNLOCK(vp); 6158 continue; 6159 } 6160 break; 6161 } 6162 if (vp == NULL) { 6163 __mnt_vnode_markerfree_all(mvp, mp); 6164 /* MNT_IUNLOCK(mp); -- done in above function */ 6165 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6166 return (NULL); 6167 } 6168 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6169 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6170 MNT_IUNLOCK(mp); 6171 return (vp); 6172 } 6173 6174 struct vnode * 6175 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6176 { 6177 struct vnode *vp; 6178 6179 *mvp = vn_alloc_marker(mp); 6180 MNT_ILOCK(mp); 6181 MNT_REF(mp); 6182 6183 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6184 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6185 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6186 continue; 6187 VI_LOCK(vp); 6188 if (VN_IS_DOOMED(vp)) { 6189 VI_UNLOCK(vp); 6190 continue; 6191 } 6192 break; 6193 } 6194 if (vp == NULL) { 6195 MNT_REL(mp); 6196 MNT_IUNLOCK(mp); 6197 vn_free_marker(*mvp); 6198 *mvp = NULL; 6199 return (NULL); 6200 } 6201 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6202 MNT_IUNLOCK(mp); 6203 return (vp); 6204 } 6205 6206 void 6207 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6208 { 6209 6210 if (*mvp == NULL) { 6211 MNT_IUNLOCK(mp); 6212 return; 6213 } 6214 6215 mtx_assert(MNT_MTX(mp), MA_OWNED); 6216 6217 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6218 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6219 MNT_REL(mp); 6220 MNT_IUNLOCK(mp); 6221 vn_free_marker(*mvp); 6222 *mvp = NULL; 6223 } 6224 6225 /* 6226 * These are helper functions for filesystems to traverse their 6227 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6228 */ 6229 static void 6230 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6231 { 6232 6233 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6234 6235 MNT_ILOCK(mp); 6236 MNT_REL(mp); 6237 MNT_IUNLOCK(mp); 6238 vn_free_marker(*mvp); 6239 *mvp = NULL; 6240 } 6241 6242 /* 6243 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6244 * conventional lock order during mnt_vnode_next_lazy iteration. 6245 * 6246 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6247 * The list lock is dropped and reacquired. On success, both locks are held. 6248 * On failure, the mount vnode list lock is held but the vnode interlock is 6249 * not, and the procedure may have yielded. 6250 */ 6251 static bool 6252 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6253 struct vnode *vp) 6254 { 6255 6256 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6257 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6258 ("%s: bad marker", __func__)); 6259 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6260 ("%s: inappropriate vnode", __func__)); 6261 ASSERT_VI_UNLOCKED(vp, __func__); 6262 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6263 6264 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6265 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6266 6267 vholdnz(vp); 6268 mtx_unlock(&mp->mnt_listmtx); 6269 VI_LOCK(vp); 6270 if (VN_IS_DOOMED(vp)) { 6271 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6272 goto out_lost; 6273 } 6274 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6275 /* 6276 * Since we had a period with no locks held we may be the last 6277 * remaining user, in which case there is nothing to do. 6278 */ 6279 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6280 goto out_lost; 6281 mtx_lock(&mp->mnt_listmtx); 6282 return (true); 6283 out_lost: 6284 vdropl(vp); 6285 maybe_yield(); 6286 mtx_lock(&mp->mnt_listmtx); 6287 return (false); 6288 } 6289 6290 static struct vnode * 6291 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6292 void *cbarg) 6293 { 6294 struct vnode *vp; 6295 6296 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6297 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6298 restart: 6299 vp = TAILQ_NEXT(*mvp, v_lazylist); 6300 while (vp != NULL) { 6301 if (vp->v_type == VMARKER) { 6302 vp = TAILQ_NEXT(vp, v_lazylist); 6303 continue; 6304 } 6305 /* 6306 * See if we want to process the vnode. Note we may encounter a 6307 * long string of vnodes we don't care about and hog the list 6308 * as a result. Check for it and requeue the marker. 6309 */ 6310 VNPASS(!VN_IS_DOOMED(vp), vp); 6311 if (!cb(vp, cbarg)) { 6312 if (!should_yield()) { 6313 vp = TAILQ_NEXT(vp, v_lazylist); 6314 continue; 6315 } 6316 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 6317 v_lazylist); 6318 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 6319 v_lazylist); 6320 mtx_unlock(&mp->mnt_listmtx); 6321 kern_yield(PRI_USER); 6322 mtx_lock(&mp->mnt_listmtx); 6323 goto restart; 6324 } 6325 /* 6326 * Try-lock because this is the wrong lock order. 6327 */ 6328 if (!VI_TRYLOCK(vp) && 6329 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 6330 goto restart; 6331 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 6332 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 6333 ("alien vnode on the lazy list %p %p", vp, mp)); 6334 VNPASS(vp->v_mount == mp, vp); 6335 VNPASS(!VN_IS_DOOMED(vp), vp); 6336 break; 6337 } 6338 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6339 6340 /* Check if we are done */ 6341 if (vp == NULL) { 6342 mtx_unlock(&mp->mnt_listmtx); 6343 mnt_vnode_markerfree_lazy(mvp, mp); 6344 return (NULL); 6345 } 6346 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 6347 mtx_unlock(&mp->mnt_listmtx); 6348 ASSERT_VI_LOCKED(vp, "lazy iter"); 6349 return (vp); 6350 } 6351 6352 struct vnode * 6353 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6354 void *cbarg) 6355 { 6356 6357 if (should_yield()) 6358 kern_yield(PRI_USER); 6359 mtx_lock(&mp->mnt_listmtx); 6360 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6361 } 6362 6363 struct vnode * 6364 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6365 void *cbarg) 6366 { 6367 struct vnode *vp; 6368 6369 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 6370 return (NULL); 6371 6372 *mvp = vn_alloc_marker(mp); 6373 MNT_ILOCK(mp); 6374 MNT_REF(mp); 6375 MNT_IUNLOCK(mp); 6376 6377 mtx_lock(&mp->mnt_listmtx); 6378 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 6379 if (vp == NULL) { 6380 mtx_unlock(&mp->mnt_listmtx); 6381 mnt_vnode_markerfree_lazy(mvp, mp); 6382 return (NULL); 6383 } 6384 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 6385 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6386 } 6387 6388 void 6389 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6390 { 6391 6392 if (*mvp == NULL) 6393 return; 6394 6395 mtx_lock(&mp->mnt_listmtx); 6396 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6397 mtx_unlock(&mp->mnt_listmtx); 6398 mnt_vnode_markerfree_lazy(mvp, mp); 6399 } 6400 6401 int 6402 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 6403 { 6404 6405 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 6406 cnp->cn_flags &= ~NOEXECCHECK; 6407 return (0); 6408 } 6409 6410 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread)); 6411 } 6412