1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 37 */ 38 39 /* 40 * External virtual filesystem routines 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_ddb.h" 47 #include "opt_watchdog.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/bio.h> 52 #include <sys/buf.h> 53 #include <sys/capsicum.h> 54 #include <sys/condvar.h> 55 #include <sys/conf.h> 56 #include <sys/counter.h> 57 #include <sys/dirent.h> 58 #include <sys/event.h> 59 #include <sys/eventhandler.h> 60 #include <sys/extattr.h> 61 #include <sys/file.h> 62 #include <sys/fcntl.h> 63 #include <sys/jail.h> 64 #include <sys/kdb.h> 65 #include <sys/kernel.h> 66 #include <sys/kthread.h> 67 #include <sys/ktr.h> 68 #include <sys/lockf.h> 69 #include <sys/malloc.h> 70 #include <sys/mount.h> 71 #include <sys/namei.h> 72 #include <sys/pctrie.h> 73 #include <sys/priv.h> 74 #include <sys/reboot.h> 75 #include <sys/refcount.h> 76 #include <sys/rwlock.h> 77 #include <sys/sched.h> 78 #include <sys/sleepqueue.h> 79 #include <sys/smp.h> 80 #include <sys/stat.h> 81 #include <sys/sysctl.h> 82 #include <sys/syslog.h> 83 #include <sys/vmmeter.h> 84 #include <sys/vnode.h> 85 #include <sys/watchdog.h> 86 87 #include <machine/stdarg.h> 88 89 #include <security/mac/mac_framework.h> 90 91 #include <vm/vm.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_extern.h> 94 #include <vm/pmap.h> 95 #include <vm/vm_map.h> 96 #include <vm/vm_page.h> 97 #include <vm/vm_kern.h> 98 #include <vm/uma.h> 99 100 #ifdef DDB 101 #include <ddb/ddb.h> 102 #endif 103 104 static void delmntque(struct vnode *vp); 105 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 106 int slpflag, int slptimeo); 107 static void syncer_shutdown(void *arg, int howto); 108 static int vtryrecycle(struct vnode *vp); 109 static void v_init_counters(struct vnode *); 110 static void v_incr_devcount(struct vnode *); 111 static void v_decr_devcount(struct vnode *); 112 static void vgonel(struct vnode *); 113 static void vfs_knllock(void *arg); 114 static void vfs_knlunlock(void *arg); 115 static void vfs_knl_assert_locked(void *arg); 116 static void vfs_knl_assert_unlocked(void *arg); 117 static void destroy_vpollinfo(struct vpollinfo *vi); 118 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 119 daddr_t startlbn, daddr_t endlbn); 120 static void vnlru_recalc(void); 121 122 /* 123 * These fences are intended for cases where some synchronization is 124 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 125 * and v_usecount) updates. Access to v_iflags is generally synchronized 126 * by the interlock, but we have some internal assertions that check vnode 127 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 128 * for now. 129 */ 130 #ifdef INVARIANTS 131 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 132 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 133 #else 134 #define VNODE_REFCOUNT_FENCE_ACQ() 135 #define VNODE_REFCOUNT_FENCE_REL() 136 #endif 137 138 /* 139 * Number of vnodes in existence. Increased whenever getnewvnode() 140 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode. 141 */ 142 static u_long __exclusive_cache_line numvnodes; 143 144 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 145 "Number of vnodes in existence"); 146 147 static counter_u64_t vnodes_created; 148 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 149 "Number of vnodes created by getnewvnode"); 150 151 /* 152 * Conversion tables for conversion from vnode types to inode formats 153 * and back. 154 */ 155 enum vtype iftovt_tab[16] = { 156 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 157 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 158 }; 159 int vttoif_tab[10] = { 160 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 161 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 162 }; 163 164 /* 165 * List of allocates vnodes in the system. 166 */ 167 static TAILQ_HEAD(freelst, vnode) vnode_list; 168 static struct vnode *vnode_list_free_marker; 169 static struct vnode *vnode_list_reclaim_marker; 170 171 /* 172 * "Free" vnode target. Free vnodes are rarely completely free, but are 173 * just ones that are cheap to recycle. Usually they are for files which 174 * have been stat'd but not read; these usually have inode and namecache 175 * data attached to them. This target is the preferred minimum size of a 176 * sub-cache consisting mostly of such files. The system balances the size 177 * of this sub-cache with its complement to try to prevent either from 178 * thrashing while the other is relatively inactive. The targets express 179 * a preference for the best balance. 180 * 181 * "Above" this target there are 2 further targets (watermarks) related 182 * to recyling of free vnodes. In the best-operating case, the cache is 183 * exactly full, the free list has size between vlowat and vhiwat above the 184 * free target, and recycling from it and normal use maintains this state. 185 * Sometimes the free list is below vlowat or even empty, but this state 186 * is even better for immediate use provided the cache is not full. 187 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 188 * ones) to reach one of these states. The watermarks are currently hard- 189 * coded as 4% and 9% of the available space higher. These and the default 190 * of 25% for wantfreevnodes are too large if the memory size is large. 191 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 192 * whenever vnlru_proc() becomes active. 193 */ 194 static long wantfreevnodes; 195 static long __exclusive_cache_line freevnodes; 196 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 197 &freevnodes, 0, "Number of \"free\" vnodes"); 198 static long freevnodes_old; 199 200 static counter_u64_t recycles_count; 201 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 202 "Number of vnodes recycled to meet vnode cache targets"); 203 204 static counter_u64_t recycles_free_count; 205 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD, &recycles_free_count, 206 "Number of free vnodes recycled to meet vnode cache targets"); 207 208 /* 209 * Various variables used for debugging the new implementation of 210 * reassignbuf(). 211 * XXX these are probably of (very) limited utility now. 212 */ 213 static int reassignbufcalls; 214 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW | CTLFLAG_STATS, 215 &reassignbufcalls, 0, "Number of calls to reassignbuf"); 216 217 static counter_u64_t deferred_inact; 218 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD, &deferred_inact, 219 "Number of times inactive processing was deferred"); 220 221 /* To keep more than one thread at a time from running vfs_getnewfsid */ 222 static struct mtx mntid_mtx; 223 224 /* 225 * Lock for any access to the following: 226 * vnode_list 227 * numvnodes 228 * freevnodes 229 */ 230 static struct mtx __exclusive_cache_line vnode_list_mtx; 231 232 /* Publicly exported FS */ 233 struct nfs_public nfs_pub; 234 235 static uma_zone_t buf_trie_zone; 236 237 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 238 static uma_zone_t vnode_zone; 239 static uma_zone_t vnodepoll_zone; 240 241 /* 242 * The workitem queue. 243 * 244 * It is useful to delay writes of file data and filesystem metadata 245 * for tens of seconds so that quickly created and deleted files need 246 * not waste disk bandwidth being created and removed. To realize this, 247 * we append vnodes to a "workitem" queue. When running with a soft 248 * updates implementation, most pending metadata dependencies should 249 * not wait for more than a few seconds. Thus, mounted on block devices 250 * are delayed only about a half the time that file data is delayed. 251 * Similarly, directory updates are more critical, so are only delayed 252 * about a third the time that file data is delayed. Thus, there are 253 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 254 * one each second (driven off the filesystem syncer process). The 255 * syncer_delayno variable indicates the next queue that is to be processed. 256 * Items that need to be processed soon are placed in this queue: 257 * 258 * syncer_workitem_pending[syncer_delayno] 259 * 260 * A delay of fifteen seconds is done by placing the request fifteen 261 * entries later in the queue: 262 * 263 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 264 * 265 */ 266 static int syncer_delayno; 267 static long syncer_mask; 268 LIST_HEAD(synclist, bufobj); 269 static struct synclist *syncer_workitem_pending; 270 /* 271 * The sync_mtx protects: 272 * bo->bo_synclist 273 * sync_vnode_count 274 * syncer_delayno 275 * syncer_state 276 * syncer_workitem_pending 277 * syncer_worklist_len 278 * rushjob 279 */ 280 static struct mtx sync_mtx; 281 static struct cv sync_wakeup; 282 283 #define SYNCER_MAXDELAY 32 284 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 285 static int syncdelay = 30; /* max time to delay syncing data */ 286 static int filedelay = 30; /* time to delay syncing files */ 287 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 288 "Time to delay syncing files (in seconds)"); 289 static int dirdelay = 29; /* time to delay syncing directories */ 290 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 291 "Time to delay syncing directories (in seconds)"); 292 static int metadelay = 28; /* time to delay syncing metadata */ 293 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 294 "Time to delay syncing metadata (in seconds)"); 295 static int rushjob; /* number of slots to run ASAP */ 296 static int stat_rush_requests; /* number of times I/O speeded up */ 297 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 298 "Number of times I/O speeded up (rush requests)"); 299 300 #define VDBATCH_SIZE 8 301 struct vdbatch { 302 u_int index; 303 long freevnodes; 304 struct mtx lock; 305 struct vnode *tab[VDBATCH_SIZE]; 306 }; 307 DPCPU_DEFINE_STATIC(struct vdbatch, vd); 308 309 static void vdbatch_dequeue(struct vnode *vp); 310 311 /* 312 * When shutting down the syncer, run it at four times normal speed. 313 */ 314 #define SYNCER_SHUTDOWN_SPEEDUP 4 315 static int sync_vnode_count; 316 static int syncer_worklist_len; 317 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 318 syncer_state; 319 320 /* Target for maximum number of vnodes. */ 321 u_long desiredvnodes; 322 static u_long gapvnodes; /* gap between wanted and desired */ 323 static u_long vhiwat; /* enough extras after expansion */ 324 static u_long vlowat; /* minimal extras before expansion */ 325 static u_long vstir; /* nonzero to stir non-free vnodes */ 326 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 327 328 static u_long vnlru_read_freevnodes(void); 329 330 /* 331 * Note that no attempt is made to sanitize these parameters. 332 */ 333 static int 334 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS) 335 { 336 u_long val; 337 int error; 338 339 val = desiredvnodes; 340 error = sysctl_handle_long(oidp, &val, 0, req); 341 if (error != 0 || req->newptr == NULL) 342 return (error); 343 344 if (val == desiredvnodes) 345 return (0); 346 mtx_lock(&vnode_list_mtx); 347 desiredvnodes = val; 348 wantfreevnodes = desiredvnodes / 4; 349 vnlru_recalc(); 350 mtx_unlock(&vnode_list_mtx); 351 /* 352 * XXX There is no protection against multiple threads changing 353 * desiredvnodes at the same time. Locking above only helps vnlru and 354 * getnewvnode. 355 */ 356 vfs_hash_changesize(desiredvnodes); 357 cache_changesize(desiredvnodes); 358 return (0); 359 } 360 361 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 362 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes, 363 "LU", "Target for maximum number of vnodes"); 364 365 static int 366 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS) 367 { 368 u_long val; 369 int error; 370 371 val = wantfreevnodes; 372 error = sysctl_handle_long(oidp, &val, 0, req); 373 if (error != 0 || req->newptr == NULL) 374 return (error); 375 376 if (val == wantfreevnodes) 377 return (0); 378 mtx_lock(&vnode_list_mtx); 379 wantfreevnodes = val; 380 vnlru_recalc(); 381 mtx_unlock(&vnode_list_mtx); 382 return (0); 383 } 384 385 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes, 386 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes, 387 "LU", "Target for minimum number of \"free\" vnodes"); 388 389 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 390 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 391 static int vnlru_nowhere; 392 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 393 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 394 395 static int 396 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 397 { 398 struct vnode *vp; 399 struct nameidata nd; 400 char *buf; 401 unsigned long ndflags; 402 int error; 403 404 if (req->newptr == NULL) 405 return (EINVAL); 406 if (req->newlen >= PATH_MAX) 407 return (E2BIG); 408 409 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK); 410 error = SYSCTL_IN(req, buf, req->newlen); 411 if (error != 0) 412 goto out; 413 414 buf[req->newlen] = '\0'; 415 416 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME; 417 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); 418 if ((error = namei(&nd)) != 0) 419 goto out; 420 vp = nd.ni_vp; 421 422 if (VN_IS_DOOMED(vp)) { 423 /* 424 * This vnode is being recycled. Return != 0 to let the caller 425 * know that the sysctl had no effect. Return EAGAIN because a 426 * subsequent call will likely succeed (since namei will create 427 * a new vnode if necessary) 428 */ 429 error = EAGAIN; 430 goto putvnode; 431 } 432 433 counter_u64_add(recycles_count, 1); 434 vgone(vp); 435 putvnode: 436 NDFREE(&nd, 0); 437 out: 438 free(buf, M_TEMP); 439 return (error); 440 } 441 442 static int 443 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 444 { 445 struct thread *td = curthread; 446 struct vnode *vp; 447 struct file *fp; 448 int error; 449 int fd; 450 451 if (req->newptr == NULL) 452 return (EBADF); 453 454 error = sysctl_handle_int(oidp, &fd, 0, req); 455 if (error != 0) 456 return (error); 457 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 458 if (error != 0) 459 return (error); 460 vp = fp->f_vnode; 461 462 error = vn_lock(vp, LK_EXCLUSIVE); 463 if (error != 0) 464 goto drop; 465 466 counter_u64_add(recycles_count, 1); 467 vgone(vp); 468 VOP_UNLOCK(vp); 469 drop: 470 fdrop(fp, td); 471 return (error); 472 } 473 474 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 475 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 476 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 477 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 478 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 479 sysctl_ftry_reclaim_vnode, "I", 480 "Try to reclaim a vnode by its file descriptor"); 481 482 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 483 static int vnsz2log; 484 485 /* 486 * Support for the bufobj clean & dirty pctrie. 487 */ 488 static void * 489 buf_trie_alloc(struct pctrie *ptree) 490 { 491 492 return uma_zalloc(buf_trie_zone, M_NOWAIT); 493 } 494 495 static void 496 buf_trie_free(struct pctrie *ptree, void *node) 497 { 498 499 uma_zfree(buf_trie_zone, node); 500 } 501 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 502 503 /* 504 * Initialize the vnode management data structures. 505 * 506 * Reevaluate the following cap on the number of vnodes after the physical 507 * memory size exceeds 512GB. In the limit, as the physical memory size 508 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 509 */ 510 #ifndef MAXVNODES_MAX 511 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */ 512 #endif 513 514 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 515 516 static struct vnode * 517 vn_alloc_marker(struct mount *mp) 518 { 519 struct vnode *vp; 520 521 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 522 vp->v_type = VMARKER; 523 vp->v_mount = mp; 524 525 return (vp); 526 } 527 528 static void 529 vn_free_marker(struct vnode *vp) 530 { 531 532 MPASS(vp->v_type == VMARKER); 533 free(vp, M_VNODE_MARKER); 534 } 535 536 /* 537 * Initialize a vnode as it first enters the zone. 538 */ 539 static int 540 vnode_init(void *mem, int size, int flags) 541 { 542 struct vnode *vp; 543 544 vp = mem; 545 bzero(vp, size); 546 /* 547 * Setup locks. 548 */ 549 vp->v_vnlock = &vp->v_lock; 550 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 551 /* 552 * By default, don't allow shared locks unless filesystems opt-in. 553 */ 554 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 555 LK_NOSHARE | LK_IS_VNODE); 556 /* 557 * Initialize bufobj. 558 */ 559 bufobj_init(&vp->v_bufobj, vp); 560 /* 561 * Initialize namecache. 562 */ 563 LIST_INIT(&vp->v_cache_src); 564 TAILQ_INIT(&vp->v_cache_dst); 565 /* 566 * Initialize rangelocks. 567 */ 568 rangelock_init(&vp->v_rl); 569 570 vp->v_dbatchcpu = NOCPU; 571 572 mtx_lock(&vnode_list_mtx); 573 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist); 574 mtx_unlock(&vnode_list_mtx); 575 return (0); 576 } 577 578 /* 579 * Free a vnode when it is cleared from the zone. 580 */ 581 static void 582 vnode_fini(void *mem, int size) 583 { 584 struct vnode *vp; 585 struct bufobj *bo; 586 587 vp = mem; 588 vdbatch_dequeue(vp); 589 mtx_lock(&vnode_list_mtx); 590 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 591 mtx_unlock(&vnode_list_mtx); 592 rangelock_destroy(&vp->v_rl); 593 lockdestroy(vp->v_vnlock); 594 mtx_destroy(&vp->v_interlock); 595 bo = &vp->v_bufobj; 596 rw_destroy(BO_LOCKPTR(bo)); 597 } 598 599 /* 600 * Provide the size of NFS nclnode and NFS fh for calculation of the 601 * vnode memory consumption. The size is specified directly to 602 * eliminate dependency on NFS-private header. 603 * 604 * Other filesystems may use bigger or smaller (like UFS and ZFS) 605 * private inode data, but the NFS-based estimation is ample enough. 606 * Still, we care about differences in the size between 64- and 32-bit 607 * platforms. 608 * 609 * Namecache structure size is heuristically 610 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 611 */ 612 #ifdef _LP64 613 #define NFS_NCLNODE_SZ (528 + 64) 614 #define NC_SZ 148 615 #else 616 #define NFS_NCLNODE_SZ (360 + 32) 617 #define NC_SZ 92 618 #endif 619 620 static void 621 vntblinit(void *dummy __unused) 622 { 623 struct vdbatch *vd; 624 int cpu, physvnodes, virtvnodes; 625 u_int i; 626 627 /* 628 * Desiredvnodes is a function of the physical memory size and the 629 * kernel's heap size. Generally speaking, it scales with the 630 * physical memory size. The ratio of desiredvnodes to the physical 631 * memory size is 1:16 until desiredvnodes exceeds 98,304. 632 * Thereafter, the 633 * marginal ratio of desiredvnodes to the physical memory size is 634 * 1:64. However, desiredvnodes is limited by the kernel's heap 635 * size. The memory required by desiredvnodes vnodes and vm objects 636 * must not exceed 1/10th of the kernel's heap size. 637 */ 638 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 639 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 640 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 641 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 642 desiredvnodes = min(physvnodes, virtvnodes); 643 if (desiredvnodes > MAXVNODES_MAX) { 644 if (bootverbose) 645 printf("Reducing kern.maxvnodes %lu -> %lu\n", 646 desiredvnodes, MAXVNODES_MAX); 647 desiredvnodes = MAXVNODES_MAX; 648 } 649 wantfreevnodes = desiredvnodes / 4; 650 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 651 TAILQ_INIT(&vnode_list); 652 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF); 653 /* 654 * The lock is taken to appease WITNESS. 655 */ 656 mtx_lock(&vnode_list_mtx); 657 vnlru_recalc(); 658 mtx_unlock(&vnode_list_mtx); 659 vnode_list_free_marker = vn_alloc_marker(NULL); 660 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist); 661 vnode_list_reclaim_marker = vn_alloc_marker(NULL); 662 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist); 663 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 664 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 665 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 666 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 667 /* 668 * Preallocate enough nodes to support one-per buf so that 669 * we can not fail an insert. reassignbuf() callers can not 670 * tolerate the insertion failure. 671 */ 672 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 673 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 674 UMA_ZONE_NOFREE); 675 uma_prealloc(buf_trie_zone, nbuf); 676 677 vnodes_created = counter_u64_alloc(M_WAITOK); 678 recycles_count = counter_u64_alloc(M_WAITOK); 679 recycles_free_count = counter_u64_alloc(M_WAITOK); 680 deferred_inact = counter_u64_alloc(M_WAITOK); 681 682 /* 683 * Initialize the filesystem syncer. 684 */ 685 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 686 &syncer_mask); 687 syncer_maxdelay = syncer_mask + 1; 688 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 689 cv_init(&sync_wakeup, "syncer"); 690 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 691 vnsz2log++; 692 vnsz2log--; 693 694 CPU_FOREACH(cpu) { 695 vd = DPCPU_ID_PTR((cpu), vd); 696 bzero(vd, sizeof(*vd)); 697 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF); 698 } 699 } 700 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 701 702 /* 703 * Mark a mount point as busy. Used to synchronize access and to delay 704 * unmounting. Eventually, mountlist_mtx is not released on failure. 705 * 706 * vfs_busy() is a custom lock, it can block the caller. 707 * vfs_busy() only sleeps if the unmount is active on the mount point. 708 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 709 * vnode belonging to mp. 710 * 711 * Lookup uses vfs_busy() to traverse mount points. 712 * root fs var fs 713 * / vnode lock A / vnode lock (/var) D 714 * /var vnode lock B /log vnode lock(/var/log) E 715 * vfs_busy lock C vfs_busy lock F 716 * 717 * Within each file system, the lock order is C->A->B and F->D->E. 718 * 719 * When traversing across mounts, the system follows that lock order: 720 * 721 * C->A->B 722 * | 723 * +->F->D->E 724 * 725 * The lookup() process for namei("/var") illustrates the process: 726 * VOP_LOOKUP() obtains B while A is held 727 * vfs_busy() obtains a shared lock on F while A and B are held 728 * vput() releases lock on B 729 * vput() releases lock on A 730 * VFS_ROOT() obtains lock on D while shared lock on F is held 731 * vfs_unbusy() releases shared lock on F 732 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 733 * Attempt to lock A (instead of vp_crossmp) while D is held would 734 * violate the global order, causing deadlocks. 735 * 736 * dounmount() locks B while F is drained. 737 */ 738 int 739 vfs_busy(struct mount *mp, int flags) 740 { 741 742 MPASS((flags & ~MBF_MASK) == 0); 743 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 744 745 if (vfs_op_thread_enter(mp)) { 746 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 747 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0); 748 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0); 749 vfs_mp_count_add_pcpu(mp, ref, 1); 750 vfs_mp_count_add_pcpu(mp, lockref, 1); 751 vfs_op_thread_exit(mp); 752 if (flags & MBF_MNTLSTLOCK) 753 mtx_unlock(&mountlist_mtx); 754 return (0); 755 } 756 757 MNT_ILOCK(mp); 758 vfs_assert_mount_counters(mp); 759 MNT_REF(mp); 760 /* 761 * If mount point is currently being unmounted, sleep until the 762 * mount point fate is decided. If thread doing the unmounting fails, 763 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 764 * that this mount point has survived the unmount attempt and vfs_busy 765 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 766 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 767 * about to be really destroyed. vfs_busy needs to release its 768 * reference on the mount point in this case and return with ENOENT, 769 * telling the caller that mount mount it tried to busy is no longer 770 * valid. 771 */ 772 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 773 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 774 MNT_REL(mp); 775 MNT_IUNLOCK(mp); 776 CTR1(KTR_VFS, "%s: failed busying before sleeping", 777 __func__); 778 return (ENOENT); 779 } 780 if (flags & MBF_MNTLSTLOCK) 781 mtx_unlock(&mountlist_mtx); 782 mp->mnt_kern_flag |= MNTK_MWAIT; 783 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 784 if (flags & MBF_MNTLSTLOCK) 785 mtx_lock(&mountlist_mtx); 786 MNT_ILOCK(mp); 787 } 788 if (flags & MBF_MNTLSTLOCK) 789 mtx_unlock(&mountlist_mtx); 790 mp->mnt_lockref++; 791 MNT_IUNLOCK(mp); 792 return (0); 793 } 794 795 /* 796 * Free a busy filesystem. 797 */ 798 void 799 vfs_unbusy(struct mount *mp) 800 { 801 int c; 802 803 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 804 805 if (vfs_op_thread_enter(mp)) { 806 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 807 vfs_mp_count_sub_pcpu(mp, lockref, 1); 808 vfs_mp_count_sub_pcpu(mp, ref, 1); 809 vfs_op_thread_exit(mp); 810 return; 811 } 812 813 MNT_ILOCK(mp); 814 vfs_assert_mount_counters(mp); 815 MNT_REL(mp); 816 c = --mp->mnt_lockref; 817 if (mp->mnt_vfs_ops == 0) { 818 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 819 MNT_IUNLOCK(mp); 820 return; 821 } 822 if (c < 0) 823 vfs_dump_mount_counters(mp); 824 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 825 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 826 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 827 mp->mnt_kern_flag &= ~MNTK_DRAINING; 828 wakeup(&mp->mnt_lockref); 829 } 830 MNT_IUNLOCK(mp); 831 } 832 833 /* 834 * Lookup a mount point by filesystem identifier. 835 */ 836 struct mount * 837 vfs_getvfs(fsid_t *fsid) 838 { 839 struct mount *mp; 840 841 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 842 mtx_lock(&mountlist_mtx); 843 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 844 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 845 vfs_ref(mp); 846 mtx_unlock(&mountlist_mtx); 847 return (mp); 848 } 849 } 850 mtx_unlock(&mountlist_mtx); 851 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 852 return ((struct mount *) 0); 853 } 854 855 /* 856 * Lookup a mount point by filesystem identifier, busying it before 857 * returning. 858 * 859 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 860 * cache for popular filesystem identifiers. The cache is lockess, using 861 * the fact that struct mount's are never freed. In worst case we may 862 * get pointer to unmounted or even different filesystem, so we have to 863 * check what we got, and go slow way if so. 864 */ 865 struct mount * 866 vfs_busyfs(fsid_t *fsid) 867 { 868 #define FSID_CACHE_SIZE 256 869 typedef struct mount * volatile vmp_t; 870 static vmp_t cache[FSID_CACHE_SIZE]; 871 struct mount *mp; 872 int error; 873 uint32_t hash; 874 875 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 876 hash = fsid->val[0] ^ fsid->val[1]; 877 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 878 mp = cache[hash]; 879 if (mp == NULL || fsidcmp(&mp->mnt_stat.f_fsid, fsid) != 0) 880 goto slow; 881 if (vfs_busy(mp, 0) != 0) { 882 cache[hash] = NULL; 883 goto slow; 884 } 885 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) 886 return (mp); 887 else 888 vfs_unbusy(mp); 889 890 slow: 891 mtx_lock(&mountlist_mtx); 892 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 893 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 894 error = vfs_busy(mp, MBF_MNTLSTLOCK); 895 if (error) { 896 cache[hash] = NULL; 897 mtx_unlock(&mountlist_mtx); 898 return (NULL); 899 } 900 cache[hash] = mp; 901 return (mp); 902 } 903 } 904 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 905 mtx_unlock(&mountlist_mtx); 906 return ((struct mount *) 0); 907 } 908 909 /* 910 * Check if a user can access privileged mount options. 911 */ 912 int 913 vfs_suser(struct mount *mp, struct thread *td) 914 { 915 int error; 916 917 if (jailed(td->td_ucred)) { 918 /* 919 * If the jail of the calling thread lacks permission for 920 * this type of file system, deny immediately. 921 */ 922 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 923 return (EPERM); 924 925 /* 926 * If the file system was mounted outside the jail of the 927 * calling thread, deny immediately. 928 */ 929 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 930 return (EPERM); 931 } 932 933 /* 934 * If file system supports delegated administration, we don't check 935 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 936 * by the file system itself. 937 * If this is not the user that did original mount, we check for 938 * the PRIV_VFS_MOUNT_OWNER privilege. 939 */ 940 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 941 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 942 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 943 return (error); 944 } 945 return (0); 946 } 947 948 /* 949 * Get a new unique fsid. Try to make its val[0] unique, since this value 950 * will be used to create fake device numbers for stat(). Also try (but 951 * not so hard) make its val[0] unique mod 2^16, since some emulators only 952 * support 16-bit device numbers. We end up with unique val[0]'s for the 953 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 954 * 955 * Keep in mind that several mounts may be running in parallel. Starting 956 * the search one past where the previous search terminated is both a 957 * micro-optimization and a defense against returning the same fsid to 958 * different mounts. 959 */ 960 void 961 vfs_getnewfsid(struct mount *mp) 962 { 963 static uint16_t mntid_base; 964 struct mount *nmp; 965 fsid_t tfsid; 966 int mtype; 967 968 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 969 mtx_lock(&mntid_mtx); 970 mtype = mp->mnt_vfc->vfc_typenum; 971 tfsid.val[1] = mtype; 972 mtype = (mtype & 0xFF) << 24; 973 for (;;) { 974 tfsid.val[0] = makedev(255, 975 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 976 mntid_base++; 977 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 978 break; 979 vfs_rel(nmp); 980 } 981 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 982 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 983 mtx_unlock(&mntid_mtx); 984 } 985 986 /* 987 * Knob to control the precision of file timestamps: 988 * 989 * 0 = seconds only; nanoseconds zeroed. 990 * 1 = seconds and nanoseconds, accurate within 1/HZ. 991 * 2 = seconds and nanoseconds, truncated to microseconds. 992 * >=3 = seconds and nanoseconds, maximum precision. 993 */ 994 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 995 996 static int timestamp_precision = TSP_USEC; 997 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 998 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 999 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 1000 "3+: sec + ns (max. precision))"); 1001 1002 /* 1003 * Get a current timestamp. 1004 */ 1005 void 1006 vfs_timestamp(struct timespec *tsp) 1007 { 1008 struct timeval tv; 1009 1010 switch (timestamp_precision) { 1011 case TSP_SEC: 1012 tsp->tv_sec = time_second; 1013 tsp->tv_nsec = 0; 1014 break; 1015 case TSP_HZ: 1016 getnanotime(tsp); 1017 break; 1018 case TSP_USEC: 1019 microtime(&tv); 1020 TIMEVAL_TO_TIMESPEC(&tv, tsp); 1021 break; 1022 case TSP_NSEC: 1023 default: 1024 nanotime(tsp); 1025 break; 1026 } 1027 } 1028 1029 /* 1030 * Set vnode attributes to VNOVAL 1031 */ 1032 void 1033 vattr_null(struct vattr *vap) 1034 { 1035 1036 vap->va_type = VNON; 1037 vap->va_size = VNOVAL; 1038 vap->va_bytes = VNOVAL; 1039 vap->va_mode = VNOVAL; 1040 vap->va_nlink = VNOVAL; 1041 vap->va_uid = VNOVAL; 1042 vap->va_gid = VNOVAL; 1043 vap->va_fsid = VNOVAL; 1044 vap->va_fileid = VNOVAL; 1045 vap->va_blocksize = VNOVAL; 1046 vap->va_rdev = VNOVAL; 1047 vap->va_atime.tv_sec = VNOVAL; 1048 vap->va_atime.tv_nsec = VNOVAL; 1049 vap->va_mtime.tv_sec = VNOVAL; 1050 vap->va_mtime.tv_nsec = VNOVAL; 1051 vap->va_ctime.tv_sec = VNOVAL; 1052 vap->va_ctime.tv_nsec = VNOVAL; 1053 vap->va_birthtime.tv_sec = VNOVAL; 1054 vap->va_birthtime.tv_nsec = VNOVAL; 1055 vap->va_flags = VNOVAL; 1056 vap->va_gen = VNOVAL; 1057 vap->va_vaflags = 0; 1058 } 1059 1060 /* 1061 * Try to reduce the total number of vnodes. 1062 * 1063 * This routine (and its user) are buggy in at least the following ways: 1064 * - all parameters were picked years ago when RAM sizes were significantly 1065 * smaller 1066 * - it can pick vnodes based on pages used by the vm object, but filesystems 1067 * like ZFS don't use it making the pick broken 1068 * - since ZFS has its own aging policy it gets partially combated by this one 1069 * - a dedicated method should be provided for filesystems to let them decide 1070 * whether the vnode should be recycled 1071 * 1072 * This routine is called when we have too many vnodes. It attempts 1073 * to free <count> vnodes and will potentially free vnodes that still 1074 * have VM backing store (VM backing store is typically the cause 1075 * of a vnode blowout so we want to do this). Therefore, this operation 1076 * is not considered cheap. 1077 * 1078 * A number of conditions may prevent a vnode from being reclaimed. 1079 * the buffer cache may have references on the vnode, a directory 1080 * vnode may still have references due to the namei cache representing 1081 * underlying files, or the vnode may be in active use. It is not 1082 * desirable to reuse such vnodes. These conditions may cause the 1083 * number of vnodes to reach some minimum value regardless of what 1084 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 1085 * 1086 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 1087 * entries if this argument is strue 1088 * @param trigger Only reclaim vnodes with fewer than this many resident 1089 * pages. 1090 * @param target How many vnodes to reclaim. 1091 * @return The number of vnodes that were reclaimed. 1092 */ 1093 static int 1094 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target) 1095 { 1096 struct vnode *vp, *mvp; 1097 struct mount *mp; 1098 struct vm_object *object; 1099 u_long done; 1100 bool retried; 1101 1102 mtx_assert(&vnode_list_mtx, MA_OWNED); 1103 1104 retried = false; 1105 done = 0; 1106 1107 mvp = vnode_list_reclaim_marker; 1108 restart: 1109 vp = mvp; 1110 while (done < target) { 1111 vp = TAILQ_NEXT(vp, v_vnodelist); 1112 if (__predict_false(vp == NULL)) 1113 break; 1114 1115 if (__predict_false(vp->v_type == VMARKER)) 1116 continue; 1117 1118 /* 1119 * If it's been deconstructed already, it's still 1120 * referenced, or it exceeds the trigger, skip it. 1121 * Also skip free vnodes. We are trying to make space 1122 * to expand the free list, not reduce it. 1123 */ 1124 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1125 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src))) 1126 goto next_iter; 1127 1128 if (vp->v_type == VBAD || vp->v_type == VNON) 1129 goto next_iter; 1130 1131 if (!VI_TRYLOCK(vp)) 1132 goto next_iter; 1133 1134 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1135 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1136 VN_IS_DOOMED(vp) || vp->v_type == VNON) { 1137 VI_UNLOCK(vp); 1138 goto next_iter; 1139 } 1140 1141 object = atomic_load_ptr(&vp->v_object); 1142 if (object == NULL || object->resident_page_count > trigger) { 1143 VI_UNLOCK(vp); 1144 goto next_iter; 1145 } 1146 1147 vholdl(vp); 1148 VI_UNLOCK(vp); 1149 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1150 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1151 mtx_unlock(&vnode_list_mtx); 1152 1153 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1154 vdrop(vp); 1155 goto next_iter_unlocked; 1156 } 1157 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { 1158 vdrop(vp); 1159 vn_finished_write(mp); 1160 goto next_iter_unlocked; 1161 } 1162 1163 VI_LOCK(vp); 1164 if (vp->v_usecount > 0 || 1165 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1166 (vp->v_object != NULL && 1167 vp->v_object->resident_page_count > trigger)) { 1168 VOP_UNLOCK(vp); 1169 vdropl(vp); 1170 vn_finished_write(mp); 1171 goto next_iter_unlocked; 1172 } 1173 counter_u64_add(recycles_count, 1); 1174 vgonel(vp); 1175 VOP_UNLOCK(vp); 1176 vdropl(vp); 1177 vn_finished_write(mp); 1178 done++; 1179 next_iter_unlocked: 1180 if (should_yield()) 1181 kern_yield(PRI_USER); 1182 mtx_lock(&vnode_list_mtx); 1183 goto restart; 1184 next_iter: 1185 MPASS(vp->v_type != VMARKER); 1186 if (!should_yield()) 1187 continue; 1188 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1189 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1190 mtx_unlock(&vnode_list_mtx); 1191 kern_yield(PRI_USER); 1192 mtx_lock(&vnode_list_mtx); 1193 goto restart; 1194 } 1195 if (done == 0 && !retried) { 1196 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1197 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1198 retried = true; 1199 goto restart; 1200 } 1201 return (done); 1202 } 1203 1204 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1205 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1206 0, 1207 "limit on vnode free requests per call to the vnlru_free routine"); 1208 1209 /* 1210 * Attempt to reduce the free list by the requested amount. 1211 */ 1212 static int 1213 vnlru_free_locked(int count, struct vfsops *mnt_op) 1214 { 1215 struct vnode *vp, *mvp; 1216 struct mount *mp; 1217 int ocount; 1218 1219 mtx_assert(&vnode_list_mtx, MA_OWNED); 1220 if (count > max_vnlru_free) 1221 count = max_vnlru_free; 1222 ocount = count; 1223 mvp = vnode_list_free_marker; 1224 restart: 1225 vp = mvp; 1226 while (count > 0) { 1227 vp = TAILQ_NEXT(vp, v_vnodelist); 1228 if (__predict_false(vp == NULL)) { 1229 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1230 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist); 1231 break; 1232 } 1233 if (__predict_false(vp->v_type == VMARKER)) 1234 continue; 1235 1236 /* 1237 * Don't recycle if our vnode is from different type 1238 * of mount point. Note that mp is type-safe, the 1239 * check does not reach unmapped address even if 1240 * vnode is reclaimed. 1241 * Don't recycle if we can't get the interlock without 1242 * blocking. 1243 */ 1244 if (vp->v_holdcnt > 0 || (mnt_op != NULL && (mp = vp->v_mount) != NULL && 1245 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1246 continue; 1247 } 1248 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1249 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1250 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1251 VI_UNLOCK(vp); 1252 continue; 1253 } 1254 vholdl(vp); 1255 count--; 1256 mtx_unlock(&vnode_list_mtx); 1257 VI_UNLOCK(vp); 1258 vtryrecycle(vp); 1259 vdrop(vp); 1260 mtx_lock(&vnode_list_mtx); 1261 goto restart; 1262 } 1263 return (ocount - count); 1264 } 1265 1266 void 1267 vnlru_free(int count, struct vfsops *mnt_op) 1268 { 1269 1270 mtx_lock(&vnode_list_mtx); 1271 vnlru_free_locked(count, mnt_op); 1272 mtx_unlock(&vnode_list_mtx); 1273 } 1274 1275 static void 1276 vnlru_recalc(void) 1277 { 1278 1279 mtx_assert(&vnode_list_mtx, MA_OWNED); 1280 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1281 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1282 vlowat = vhiwat / 2; 1283 } 1284 1285 /* 1286 * Attempt to recycle vnodes in a context that is always safe to block. 1287 * Calling vlrurecycle() from the bowels of filesystem code has some 1288 * interesting deadlock problems. 1289 */ 1290 static struct proc *vnlruproc; 1291 static int vnlruproc_sig; 1292 1293 /* 1294 * The main freevnodes counter is only updated when threads requeue their vnode 1295 * batches. CPUs are conditionally walked to compute a more accurate total. 1296 * 1297 * Limit how much of a slop are we willing to tolerate. Note: the actual value 1298 * at any given moment can still exceed slop, but it should not be by significant 1299 * margin in practice. 1300 */ 1301 #define VNLRU_FREEVNODES_SLOP 128 1302 1303 static u_long 1304 vnlru_read_freevnodes(void) 1305 { 1306 struct vdbatch *vd; 1307 long slop; 1308 int cpu; 1309 1310 mtx_assert(&vnode_list_mtx, MA_OWNED); 1311 if (freevnodes > freevnodes_old) 1312 slop = freevnodes - freevnodes_old; 1313 else 1314 slop = freevnodes_old - freevnodes; 1315 if (slop < VNLRU_FREEVNODES_SLOP) 1316 return (freevnodes >= 0 ? freevnodes : 0); 1317 freevnodes_old = freevnodes; 1318 CPU_FOREACH(cpu) { 1319 vd = DPCPU_ID_PTR((cpu), vd); 1320 freevnodes_old += vd->freevnodes; 1321 } 1322 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1323 } 1324 1325 static bool 1326 vnlru_under(u_long rnumvnodes, u_long limit) 1327 { 1328 u_long rfreevnodes, space; 1329 1330 if (__predict_false(rnumvnodes > desiredvnodes)) 1331 return (true); 1332 1333 space = desiredvnodes - rnumvnodes; 1334 if (space < limit) { 1335 rfreevnodes = vnlru_read_freevnodes(); 1336 if (rfreevnodes > wantfreevnodes) 1337 space += rfreevnodes - wantfreevnodes; 1338 } 1339 return (space < limit); 1340 } 1341 1342 static bool 1343 vnlru_under_unlocked(u_long rnumvnodes, u_long limit) 1344 { 1345 long rfreevnodes, space; 1346 1347 if (__predict_false(rnumvnodes > desiredvnodes)) 1348 return (true); 1349 1350 space = desiredvnodes - rnumvnodes; 1351 if (space < limit) { 1352 rfreevnodes = atomic_load_long(&freevnodes); 1353 if (rfreevnodes > wantfreevnodes) 1354 space += rfreevnodes - wantfreevnodes; 1355 } 1356 return (space < limit); 1357 } 1358 1359 static void 1360 vnlru_kick(void) 1361 { 1362 1363 mtx_assert(&vnode_list_mtx, MA_OWNED); 1364 if (vnlruproc_sig == 0) { 1365 vnlruproc_sig = 1; 1366 wakeup(vnlruproc); 1367 } 1368 } 1369 1370 static void 1371 vnlru_proc(void) 1372 { 1373 u_long rnumvnodes, rfreevnodes, target; 1374 unsigned long onumvnodes; 1375 int done, force, trigger, usevnodes; 1376 bool reclaim_nc_src, want_reread; 1377 1378 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1379 SHUTDOWN_PRI_FIRST); 1380 1381 force = 0; 1382 want_reread = false; 1383 for (;;) { 1384 kproc_suspend_check(vnlruproc); 1385 mtx_lock(&vnode_list_mtx); 1386 rnumvnodes = atomic_load_long(&numvnodes); 1387 1388 if (want_reread) { 1389 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1390 want_reread = false; 1391 } 1392 1393 /* 1394 * If numvnodes is too large (due to desiredvnodes being 1395 * adjusted using its sysctl, or emergency growth), first 1396 * try to reduce it by discarding from the free list. 1397 */ 1398 if (rnumvnodes > desiredvnodes) { 1399 vnlru_free_locked(rnumvnodes - desiredvnodes, NULL); 1400 rnumvnodes = atomic_load_long(&numvnodes); 1401 } 1402 /* 1403 * Sleep if the vnode cache is in a good state. This is 1404 * when it is not over-full and has space for about a 4% 1405 * or 9% expansion (by growing its size or inexcessively 1406 * reducing its free list). Otherwise, try to reclaim 1407 * space for a 10% expansion. 1408 */ 1409 if (vstir && force == 0) { 1410 force = 1; 1411 vstir = 0; 1412 } 1413 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1414 vnlruproc_sig = 0; 1415 wakeup(&vnlruproc_sig); 1416 msleep(vnlruproc, &vnode_list_mtx, 1417 PVFS|PDROP, "vlruwt", hz); 1418 continue; 1419 } 1420 rfreevnodes = vnlru_read_freevnodes(); 1421 1422 onumvnodes = rnumvnodes; 1423 /* 1424 * Calculate parameters for recycling. These are the same 1425 * throughout the loop to give some semblance of fairness. 1426 * The trigger point is to avoid recycling vnodes with lots 1427 * of resident pages. We aren't trying to free memory; we 1428 * are trying to recycle or at least free vnodes. 1429 */ 1430 if (rnumvnodes <= desiredvnodes) 1431 usevnodes = rnumvnodes - rfreevnodes; 1432 else 1433 usevnodes = rnumvnodes; 1434 if (usevnodes <= 0) 1435 usevnodes = 1; 1436 /* 1437 * The trigger value is is chosen to give a conservatively 1438 * large value to ensure that it alone doesn't prevent 1439 * making progress. The value can easily be so large that 1440 * it is effectively infinite in some congested and 1441 * misconfigured cases, and this is necessary. Normally 1442 * it is about 8 to 100 (pages), which is quite large. 1443 */ 1444 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1445 if (force < 2) 1446 trigger = vsmalltrigger; 1447 reclaim_nc_src = force >= 3; 1448 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1449 target = target / 10 + 1; 1450 done = vlrureclaim(reclaim_nc_src, trigger, target); 1451 mtx_unlock(&vnode_list_mtx); 1452 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1453 uma_reclaim(UMA_RECLAIM_DRAIN); 1454 if (done == 0) { 1455 if (force == 0 || force == 1) { 1456 force = 2; 1457 continue; 1458 } 1459 if (force == 2) { 1460 force = 3; 1461 continue; 1462 } 1463 want_reread = true; 1464 force = 0; 1465 vnlru_nowhere++; 1466 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1467 } else { 1468 want_reread = true; 1469 kern_yield(PRI_USER); 1470 } 1471 } 1472 } 1473 1474 static struct kproc_desc vnlru_kp = { 1475 "vnlru", 1476 vnlru_proc, 1477 &vnlruproc 1478 }; 1479 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1480 &vnlru_kp); 1481 1482 /* 1483 * Routines having to do with the management of the vnode table. 1484 */ 1485 1486 /* 1487 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1488 * before we actually vgone(). This function must be called with the vnode 1489 * held to prevent the vnode from being returned to the free list midway 1490 * through vgone(). 1491 */ 1492 static int 1493 vtryrecycle(struct vnode *vp) 1494 { 1495 struct mount *vnmp; 1496 1497 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1498 VNASSERT(vp->v_holdcnt, vp, 1499 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1500 /* 1501 * This vnode may found and locked via some other list, if so we 1502 * can't recycle it yet. 1503 */ 1504 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1505 CTR2(KTR_VFS, 1506 "%s: impossible to recycle, vp %p lock is already held", 1507 __func__, vp); 1508 return (EWOULDBLOCK); 1509 } 1510 /* 1511 * Don't recycle if its filesystem is being suspended. 1512 */ 1513 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1514 VOP_UNLOCK(vp); 1515 CTR2(KTR_VFS, 1516 "%s: impossible to recycle, cannot start the write for %p", 1517 __func__, vp); 1518 return (EBUSY); 1519 } 1520 /* 1521 * If we got this far, we need to acquire the interlock and see if 1522 * anyone picked up this vnode from another list. If not, we will 1523 * mark it with DOOMED via vgonel() so that anyone who does find it 1524 * will skip over it. 1525 */ 1526 VI_LOCK(vp); 1527 if (vp->v_usecount) { 1528 VOP_UNLOCK(vp); 1529 VI_UNLOCK(vp); 1530 vn_finished_write(vnmp); 1531 CTR2(KTR_VFS, 1532 "%s: impossible to recycle, %p is already referenced", 1533 __func__, vp); 1534 return (EBUSY); 1535 } 1536 if (!VN_IS_DOOMED(vp)) { 1537 counter_u64_add(recycles_free_count, 1); 1538 vgonel(vp); 1539 } 1540 VOP_UNLOCK(vp); 1541 VI_UNLOCK(vp); 1542 vn_finished_write(vnmp); 1543 return (0); 1544 } 1545 1546 /* 1547 * Allocate a new vnode. 1548 * 1549 * The operation never returns an error. Returning an error was disabled 1550 * in r145385 (dated 2005) with the following comment: 1551 * 1552 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1553 * 1554 * Given the age of this commit (almost 15 years at the time of writing this 1555 * comment) restoring the ability to fail requires a significant audit of 1556 * all codepaths. 1557 * 1558 * The routine can try to free a vnode or stall for up to 1 second waiting for 1559 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1560 */ 1561 static u_long vn_alloc_cyclecount; 1562 1563 static struct vnode * __noinline 1564 vn_alloc_hard(struct mount *mp) 1565 { 1566 u_long rnumvnodes, rfreevnodes; 1567 1568 mtx_lock(&vnode_list_mtx); 1569 rnumvnodes = atomic_load_long(&numvnodes); 1570 if (rnumvnodes + 1 < desiredvnodes) { 1571 vn_alloc_cyclecount = 0; 1572 goto alloc; 1573 } 1574 rfreevnodes = vnlru_read_freevnodes(); 1575 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1576 vn_alloc_cyclecount = 0; 1577 vstir = 1; 1578 } 1579 /* 1580 * Grow the vnode cache if it will not be above its target max 1581 * after growing. Otherwise, if the free list is nonempty, try 1582 * to reclaim 1 item from it before growing the cache (possibly 1583 * above its target max if the reclamation failed or is delayed). 1584 * Otherwise, wait for some space. In all cases, schedule 1585 * vnlru_proc() if we are getting short of space. The watermarks 1586 * should be chosen so that we never wait or even reclaim from 1587 * the free list to below its target minimum. 1588 */ 1589 if (vnlru_free_locked(1, NULL) > 0) 1590 goto alloc; 1591 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1592 /* 1593 * Wait for space for a new vnode. 1594 */ 1595 vnlru_kick(); 1596 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1597 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1598 vnlru_read_freevnodes() > 1) 1599 vnlru_free_locked(1, NULL); 1600 } 1601 alloc: 1602 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1603 if (vnlru_under(rnumvnodes, vlowat)) 1604 vnlru_kick(); 1605 mtx_unlock(&vnode_list_mtx); 1606 return (uma_zalloc(vnode_zone, M_WAITOK)); 1607 } 1608 1609 static struct vnode * 1610 vn_alloc(struct mount *mp) 1611 { 1612 u_long rnumvnodes; 1613 1614 if (__predict_false(vn_alloc_cyclecount != 0)) 1615 return (vn_alloc_hard(mp)); 1616 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1617 if (__predict_false(vnlru_under_unlocked(rnumvnodes, vlowat))) { 1618 atomic_subtract_long(&numvnodes, 1); 1619 return (vn_alloc_hard(mp)); 1620 } 1621 1622 return (uma_zalloc(vnode_zone, M_WAITOK)); 1623 } 1624 1625 static void 1626 vn_free(struct vnode *vp) 1627 { 1628 1629 atomic_subtract_long(&numvnodes, 1); 1630 uma_zfree(vnode_zone, vp); 1631 } 1632 1633 /* 1634 * Return the next vnode from the free list. 1635 */ 1636 int 1637 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1638 struct vnode **vpp) 1639 { 1640 struct vnode *vp; 1641 struct thread *td; 1642 struct lock_object *lo; 1643 1644 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1645 1646 KASSERT(vops->registered, 1647 ("%s: not registered vector op %p\n", __func__, vops)); 1648 1649 td = curthread; 1650 if (td->td_vp_reserved != NULL) { 1651 vp = td->td_vp_reserved; 1652 td->td_vp_reserved = NULL; 1653 } else { 1654 vp = vn_alloc(mp); 1655 } 1656 counter_u64_add(vnodes_created, 1); 1657 /* 1658 * Locks are given the generic name "vnode" when created. 1659 * Follow the historic practice of using the filesystem 1660 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1661 * 1662 * Locks live in a witness group keyed on their name. Thus, 1663 * when a lock is renamed, it must also move from the witness 1664 * group of its old name to the witness group of its new name. 1665 * 1666 * The change only needs to be made when the vnode moves 1667 * from one filesystem type to another. We ensure that each 1668 * filesystem use a single static name pointer for its tag so 1669 * that we can compare pointers rather than doing a strcmp(). 1670 */ 1671 lo = &vp->v_vnlock->lock_object; 1672 #ifdef WITNESS 1673 if (lo->lo_name != tag) { 1674 #endif 1675 lo->lo_name = tag; 1676 #ifdef WITNESS 1677 WITNESS_DESTROY(lo); 1678 WITNESS_INIT(lo, tag); 1679 } 1680 #endif 1681 /* 1682 * By default, don't allow shared locks unless filesystems opt-in. 1683 */ 1684 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1685 /* 1686 * Finalize various vnode identity bits. 1687 */ 1688 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1689 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1690 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1691 vp->v_type = VNON; 1692 vp->v_op = vops; 1693 v_init_counters(vp); 1694 vp->v_bufobj.bo_ops = &buf_ops_bio; 1695 #ifdef DIAGNOSTIC 1696 if (mp == NULL && vops != &dead_vnodeops) 1697 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1698 #endif 1699 #ifdef MAC 1700 mac_vnode_init(vp); 1701 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1702 mac_vnode_associate_singlelabel(mp, vp); 1703 #endif 1704 if (mp != NULL) { 1705 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1706 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1707 vp->v_vflag |= VV_NOKNOTE; 1708 } 1709 1710 /* 1711 * For the filesystems which do not use vfs_hash_insert(), 1712 * still initialize v_hash to have vfs_hash_index() useful. 1713 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1714 * its own hashing. 1715 */ 1716 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1717 1718 *vpp = vp; 1719 return (0); 1720 } 1721 1722 void 1723 getnewvnode_reserve(void) 1724 { 1725 struct thread *td; 1726 1727 td = curthread; 1728 MPASS(td->td_vp_reserved == NULL); 1729 td->td_vp_reserved = vn_alloc(NULL); 1730 } 1731 1732 void 1733 getnewvnode_drop_reserve(void) 1734 { 1735 struct thread *td; 1736 1737 td = curthread; 1738 if (td->td_vp_reserved != NULL) { 1739 vn_free(td->td_vp_reserved); 1740 td->td_vp_reserved = NULL; 1741 } 1742 } 1743 1744 static void 1745 freevnode(struct vnode *vp) 1746 { 1747 struct bufobj *bo; 1748 1749 /* 1750 * The vnode has been marked for destruction, so free it. 1751 * 1752 * The vnode will be returned to the zone where it will 1753 * normally remain until it is needed for another vnode. We 1754 * need to cleanup (or verify that the cleanup has already 1755 * been done) any residual data left from its current use 1756 * so as not to contaminate the freshly allocated vnode. 1757 */ 1758 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1759 bo = &vp->v_bufobj; 1760 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1761 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 1762 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1763 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1764 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1765 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1766 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1767 ("clean blk trie not empty")); 1768 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1769 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1770 ("dirty blk trie not empty")); 1771 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1772 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1773 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1774 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1775 ("Dangling rangelock waiters")); 1776 VI_UNLOCK(vp); 1777 #ifdef MAC 1778 mac_vnode_destroy(vp); 1779 #endif 1780 if (vp->v_pollinfo != NULL) { 1781 destroy_vpollinfo(vp->v_pollinfo); 1782 vp->v_pollinfo = NULL; 1783 } 1784 #ifdef INVARIANTS 1785 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1786 vp->v_op = NULL; 1787 #endif 1788 vp->v_mountedhere = NULL; 1789 vp->v_unpcb = NULL; 1790 vp->v_rdev = NULL; 1791 vp->v_fifoinfo = NULL; 1792 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1793 vp->v_irflag = 0; 1794 vp->v_iflag = 0; 1795 vp->v_vflag = 0; 1796 bo->bo_flag = 0; 1797 vn_free(vp); 1798 } 1799 1800 /* 1801 * Delete from old mount point vnode list, if on one. 1802 */ 1803 static void 1804 delmntque(struct vnode *vp) 1805 { 1806 struct mount *mp; 1807 1808 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 1809 1810 mp = vp->v_mount; 1811 if (mp == NULL) 1812 return; 1813 MNT_ILOCK(mp); 1814 VI_LOCK(vp); 1815 vp->v_mount = NULL; 1816 VI_UNLOCK(vp); 1817 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1818 ("bad mount point vnode list size")); 1819 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1820 mp->mnt_nvnodelistsize--; 1821 MNT_REL(mp); 1822 MNT_IUNLOCK(mp); 1823 } 1824 1825 static void 1826 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1827 { 1828 1829 vp->v_data = NULL; 1830 vp->v_op = &dead_vnodeops; 1831 vgone(vp); 1832 vput(vp); 1833 } 1834 1835 /* 1836 * Insert into list of vnodes for the new mount point, if available. 1837 */ 1838 int 1839 insmntque1(struct vnode *vp, struct mount *mp, 1840 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1841 { 1842 1843 KASSERT(vp->v_mount == NULL, 1844 ("insmntque: vnode already on per mount vnode list")); 1845 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1846 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1847 1848 /* 1849 * We acquire the vnode interlock early to ensure that the 1850 * vnode cannot be recycled by another process releasing a 1851 * holdcnt on it before we get it on both the vnode list 1852 * and the active vnode list. The mount mutex protects only 1853 * manipulation of the vnode list and the vnode freelist 1854 * mutex protects only manipulation of the active vnode list. 1855 * Hence the need to hold the vnode interlock throughout. 1856 */ 1857 MNT_ILOCK(mp); 1858 VI_LOCK(vp); 1859 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1860 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1861 mp->mnt_nvnodelistsize == 0)) && 1862 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1863 VI_UNLOCK(vp); 1864 MNT_IUNLOCK(mp); 1865 if (dtr != NULL) 1866 dtr(vp, dtr_arg); 1867 return (EBUSY); 1868 } 1869 vp->v_mount = mp; 1870 MNT_REF(mp); 1871 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1872 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1873 ("neg mount point vnode list size")); 1874 mp->mnt_nvnodelistsize++; 1875 VI_UNLOCK(vp); 1876 MNT_IUNLOCK(mp); 1877 return (0); 1878 } 1879 1880 int 1881 insmntque(struct vnode *vp, struct mount *mp) 1882 { 1883 1884 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1885 } 1886 1887 /* 1888 * Flush out and invalidate all buffers associated with a bufobj 1889 * Called with the underlying object locked. 1890 */ 1891 int 1892 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1893 { 1894 int error; 1895 1896 BO_LOCK(bo); 1897 if (flags & V_SAVE) { 1898 error = bufobj_wwait(bo, slpflag, slptimeo); 1899 if (error) { 1900 BO_UNLOCK(bo); 1901 return (error); 1902 } 1903 if (bo->bo_dirty.bv_cnt > 0) { 1904 BO_UNLOCK(bo); 1905 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1906 return (error); 1907 /* 1908 * XXX We could save a lock/unlock if this was only 1909 * enabled under INVARIANTS 1910 */ 1911 BO_LOCK(bo); 1912 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1913 panic("vinvalbuf: dirty bufs"); 1914 } 1915 } 1916 /* 1917 * If you alter this loop please notice that interlock is dropped and 1918 * reacquired in flushbuflist. Special care is needed to ensure that 1919 * no race conditions occur from this. 1920 */ 1921 do { 1922 error = flushbuflist(&bo->bo_clean, 1923 flags, bo, slpflag, slptimeo); 1924 if (error == 0 && !(flags & V_CLEANONLY)) 1925 error = flushbuflist(&bo->bo_dirty, 1926 flags, bo, slpflag, slptimeo); 1927 if (error != 0 && error != EAGAIN) { 1928 BO_UNLOCK(bo); 1929 return (error); 1930 } 1931 } while (error != 0); 1932 1933 /* 1934 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1935 * have write I/O in-progress but if there is a VM object then the 1936 * VM object can also have read-I/O in-progress. 1937 */ 1938 do { 1939 bufobj_wwait(bo, 0, 0); 1940 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1941 BO_UNLOCK(bo); 1942 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1943 BO_LOCK(bo); 1944 } 1945 } while (bo->bo_numoutput > 0); 1946 BO_UNLOCK(bo); 1947 1948 /* 1949 * Destroy the copy in the VM cache, too. 1950 */ 1951 if (bo->bo_object != NULL && 1952 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1953 VM_OBJECT_WLOCK(bo->bo_object); 1954 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1955 OBJPR_CLEANONLY : 0); 1956 VM_OBJECT_WUNLOCK(bo->bo_object); 1957 } 1958 1959 #ifdef INVARIANTS 1960 BO_LOCK(bo); 1961 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1962 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1963 bo->bo_clean.bv_cnt > 0)) 1964 panic("vinvalbuf: flush failed"); 1965 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1966 bo->bo_dirty.bv_cnt > 0) 1967 panic("vinvalbuf: flush dirty failed"); 1968 BO_UNLOCK(bo); 1969 #endif 1970 return (0); 1971 } 1972 1973 /* 1974 * Flush out and invalidate all buffers associated with a vnode. 1975 * Called with the underlying object locked. 1976 */ 1977 int 1978 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1979 { 1980 1981 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1982 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1983 if (vp->v_object != NULL && vp->v_object->handle != vp) 1984 return (0); 1985 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1986 } 1987 1988 /* 1989 * Flush out buffers on the specified list. 1990 * 1991 */ 1992 static int 1993 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1994 int slptimeo) 1995 { 1996 struct buf *bp, *nbp; 1997 int retval, error; 1998 daddr_t lblkno; 1999 b_xflags_t xflags; 2000 2001 ASSERT_BO_WLOCKED(bo); 2002 2003 retval = 0; 2004 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2005 /* 2006 * If we are flushing both V_NORMAL and V_ALT buffers then 2007 * do not skip any buffers. If we are flushing only V_NORMAL 2008 * buffers then skip buffers marked as BX_ALTDATA. If we are 2009 * flushing only V_ALT buffers then skip buffers not marked 2010 * as BX_ALTDATA. 2011 */ 2012 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2013 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2014 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2015 continue; 2016 } 2017 if (nbp != NULL) { 2018 lblkno = nbp->b_lblkno; 2019 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2020 } 2021 retval = EAGAIN; 2022 error = BUF_TIMELOCK(bp, 2023 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2024 "flushbuf", slpflag, slptimeo); 2025 if (error) { 2026 BO_LOCK(bo); 2027 return (error != ENOLCK ? error : EAGAIN); 2028 } 2029 KASSERT(bp->b_bufobj == bo, 2030 ("bp %p wrong b_bufobj %p should be %p", 2031 bp, bp->b_bufobj, bo)); 2032 /* 2033 * XXX Since there are no node locks for NFS, I 2034 * believe there is a slight chance that a delayed 2035 * write will occur while sleeping just above, so 2036 * check for it. 2037 */ 2038 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2039 (flags & V_SAVE)) { 2040 bremfree(bp); 2041 bp->b_flags |= B_ASYNC; 2042 bwrite(bp); 2043 BO_LOCK(bo); 2044 return (EAGAIN); /* XXX: why not loop ? */ 2045 } 2046 bremfree(bp); 2047 bp->b_flags |= (B_INVAL | B_RELBUF); 2048 bp->b_flags &= ~B_ASYNC; 2049 brelse(bp); 2050 BO_LOCK(bo); 2051 if (nbp == NULL) 2052 break; 2053 nbp = gbincore(bo, lblkno); 2054 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2055 != xflags) 2056 break; /* nbp invalid */ 2057 } 2058 return (retval); 2059 } 2060 2061 int 2062 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2063 { 2064 struct buf *bp; 2065 int error; 2066 daddr_t lblkno; 2067 2068 ASSERT_BO_LOCKED(bo); 2069 2070 for (lblkno = startn;;) { 2071 again: 2072 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2073 if (bp == NULL || bp->b_lblkno >= endn || 2074 bp->b_lblkno < startn) 2075 break; 2076 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2077 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2078 if (error != 0) { 2079 BO_RLOCK(bo); 2080 if (error == ENOLCK) 2081 goto again; 2082 return (error); 2083 } 2084 KASSERT(bp->b_bufobj == bo, 2085 ("bp %p wrong b_bufobj %p should be %p", 2086 bp, bp->b_bufobj, bo)); 2087 lblkno = bp->b_lblkno + 1; 2088 if ((bp->b_flags & B_MANAGED) == 0) 2089 bremfree(bp); 2090 bp->b_flags |= B_RELBUF; 2091 /* 2092 * In the VMIO case, use the B_NOREUSE flag to hint that the 2093 * pages backing each buffer in the range are unlikely to be 2094 * reused. Dirty buffers will have the hint applied once 2095 * they've been written. 2096 */ 2097 if ((bp->b_flags & B_VMIO) != 0) 2098 bp->b_flags |= B_NOREUSE; 2099 brelse(bp); 2100 BO_RLOCK(bo); 2101 } 2102 return (0); 2103 } 2104 2105 /* 2106 * Truncate a file's buffer and pages to a specified length. This 2107 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2108 * sync activity. 2109 */ 2110 int 2111 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2112 { 2113 struct buf *bp, *nbp; 2114 struct bufobj *bo; 2115 daddr_t startlbn; 2116 2117 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2118 vp, blksize, (uintmax_t)length); 2119 2120 /* 2121 * Round up to the *next* lbn. 2122 */ 2123 startlbn = howmany(length, blksize); 2124 2125 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2126 2127 bo = &vp->v_bufobj; 2128 restart_unlocked: 2129 BO_LOCK(bo); 2130 2131 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2132 ; 2133 2134 if (length > 0) { 2135 restartsync: 2136 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2137 if (bp->b_lblkno > 0) 2138 continue; 2139 /* 2140 * Since we hold the vnode lock this should only 2141 * fail if we're racing with the buf daemon. 2142 */ 2143 if (BUF_LOCK(bp, 2144 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2145 BO_LOCKPTR(bo)) == ENOLCK) 2146 goto restart_unlocked; 2147 2148 VNASSERT((bp->b_flags & B_DELWRI), vp, 2149 ("buf(%p) on dirty queue without DELWRI", bp)); 2150 2151 bremfree(bp); 2152 bawrite(bp); 2153 BO_LOCK(bo); 2154 goto restartsync; 2155 } 2156 } 2157 2158 bufobj_wwait(bo, 0, 0); 2159 BO_UNLOCK(bo); 2160 vnode_pager_setsize(vp, length); 2161 2162 return (0); 2163 } 2164 2165 /* 2166 * Invalidate the cached pages of a file's buffer within the range of block 2167 * numbers [startlbn, endlbn). 2168 */ 2169 void 2170 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2171 int blksize) 2172 { 2173 struct bufobj *bo; 2174 off_t start, end; 2175 2176 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2177 2178 start = blksize * startlbn; 2179 end = blksize * endlbn; 2180 2181 bo = &vp->v_bufobj; 2182 BO_LOCK(bo); 2183 MPASS(blksize == bo->bo_bsize); 2184 2185 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2186 ; 2187 2188 BO_UNLOCK(bo); 2189 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2190 } 2191 2192 static int 2193 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2194 daddr_t startlbn, daddr_t endlbn) 2195 { 2196 struct buf *bp, *nbp; 2197 bool anyfreed; 2198 2199 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2200 ASSERT_BO_LOCKED(bo); 2201 2202 do { 2203 anyfreed = false; 2204 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2205 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2206 continue; 2207 if (BUF_LOCK(bp, 2208 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2209 BO_LOCKPTR(bo)) == ENOLCK) { 2210 BO_LOCK(bo); 2211 return (EAGAIN); 2212 } 2213 2214 bremfree(bp); 2215 bp->b_flags |= B_INVAL | B_RELBUF; 2216 bp->b_flags &= ~B_ASYNC; 2217 brelse(bp); 2218 anyfreed = true; 2219 2220 BO_LOCK(bo); 2221 if (nbp != NULL && 2222 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2223 nbp->b_vp != vp || 2224 (nbp->b_flags & B_DELWRI) != 0)) 2225 return (EAGAIN); 2226 } 2227 2228 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2229 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2230 continue; 2231 if (BUF_LOCK(bp, 2232 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2233 BO_LOCKPTR(bo)) == ENOLCK) { 2234 BO_LOCK(bo); 2235 return (EAGAIN); 2236 } 2237 bremfree(bp); 2238 bp->b_flags |= B_INVAL | B_RELBUF; 2239 bp->b_flags &= ~B_ASYNC; 2240 brelse(bp); 2241 anyfreed = true; 2242 2243 BO_LOCK(bo); 2244 if (nbp != NULL && 2245 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2246 (nbp->b_vp != vp) || 2247 (nbp->b_flags & B_DELWRI) == 0)) 2248 return (EAGAIN); 2249 } 2250 } while (anyfreed); 2251 return (0); 2252 } 2253 2254 static void 2255 buf_vlist_remove(struct buf *bp) 2256 { 2257 struct bufv *bv; 2258 2259 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2260 ASSERT_BO_WLOCKED(bp->b_bufobj); 2261 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 2262 (BX_VNDIRTY|BX_VNCLEAN), 2263 ("buf_vlist_remove: Buf %p is on two lists", bp)); 2264 if (bp->b_xflags & BX_VNDIRTY) 2265 bv = &bp->b_bufobj->bo_dirty; 2266 else 2267 bv = &bp->b_bufobj->bo_clean; 2268 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2269 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2270 bv->bv_cnt--; 2271 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2272 } 2273 2274 /* 2275 * Add the buffer to the sorted clean or dirty block list. 2276 * 2277 * NOTE: xflags is passed as a constant, optimizing this inline function! 2278 */ 2279 static void 2280 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2281 { 2282 struct bufv *bv; 2283 struct buf *n; 2284 int error; 2285 2286 ASSERT_BO_WLOCKED(bo); 2287 KASSERT((bo->bo_flag & BO_NOBUFS) == 0, 2288 ("buf_vlist_add: bo %p does not allow bufs", bo)); 2289 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2290 ("dead bo %p", bo)); 2291 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2292 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2293 bp->b_xflags |= xflags; 2294 if (xflags & BX_VNDIRTY) 2295 bv = &bo->bo_dirty; 2296 else 2297 bv = &bo->bo_clean; 2298 2299 /* 2300 * Keep the list ordered. Optimize empty list insertion. Assume 2301 * we tend to grow at the tail so lookup_le should usually be cheaper 2302 * than _ge. 2303 */ 2304 if (bv->bv_cnt == 0 || 2305 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2306 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2307 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2308 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2309 else 2310 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2311 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2312 if (error) 2313 panic("buf_vlist_add: Preallocated nodes insufficient."); 2314 bv->bv_cnt++; 2315 } 2316 2317 /* 2318 * Look up a buffer using the buffer tries. 2319 */ 2320 struct buf * 2321 gbincore(struct bufobj *bo, daddr_t lblkno) 2322 { 2323 struct buf *bp; 2324 2325 ASSERT_BO_LOCKED(bo); 2326 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2327 if (bp != NULL) 2328 return (bp); 2329 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2330 } 2331 2332 /* 2333 * Associate a buffer with a vnode. 2334 */ 2335 void 2336 bgetvp(struct vnode *vp, struct buf *bp) 2337 { 2338 struct bufobj *bo; 2339 2340 bo = &vp->v_bufobj; 2341 ASSERT_BO_WLOCKED(bo); 2342 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2343 2344 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2345 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2346 ("bgetvp: bp already attached! %p", bp)); 2347 2348 vhold(vp); 2349 bp->b_vp = vp; 2350 bp->b_bufobj = bo; 2351 /* 2352 * Insert onto list for new vnode. 2353 */ 2354 buf_vlist_add(bp, bo, BX_VNCLEAN); 2355 } 2356 2357 /* 2358 * Disassociate a buffer from a vnode. 2359 */ 2360 void 2361 brelvp(struct buf *bp) 2362 { 2363 struct bufobj *bo; 2364 struct vnode *vp; 2365 2366 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2367 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2368 2369 /* 2370 * Delete from old vnode list, if on one. 2371 */ 2372 vp = bp->b_vp; /* XXX */ 2373 bo = bp->b_bufobj; 2374 BO_LOCK(bo); 2375 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2376 buf_vlist_remove(bp); 2377 else 2378 panic("brelvp: Buffer %p not on queue.", bp); 2379 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2380 bo->bo_flag &= ~BO_ONWORKLST; 2381 mtx_lock(&sync_mtx); 2382 LIST_REMOVE(bo, bo_synclist); 2383 syncer_worklist_len--; 2384 mtx_unlock(&sync_mtx); 2385 } 2386 bp->b_vp = NULL; 2387 bp->b_bufobj = NULL; 2388 BO_UNLOCK(bo); 2389 vdrop(vp); 2390 } 2391 2392 /* 2393 * Add an item to the syncer work queue. 2394 */ 2395 static void 2396 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2397 { 2398 int slot; 2399 2400 ASSERT_BO_WLOCKED(bo); 2401 2402 mtx_lock(&sync_mtx); 2403 if (bo->bo_flag & BO_ONWORKLST) 2404 LIST_REMOVE(bo, bo_synclist); 2405 else { 2406 bo->bo_flag |= BO_ONWORKLST; 2407 syncer_worklist_len++; 2408 } 2409 2410 if (delay > syncer_maxdelay - 2) 2411 delay = syncer_maxdelay - 2; 2412 slot = (syncer_delayno + delay) & syncer_mask; 2413 2414 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2415 mtx_unlock(&sync_mtx); 2416 } 2417 2418 static int 2419 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2420 { 2421 int error, len; 2422 2423 mtx_lock(&sync_mtx); 2424 len = syncer_worklist_len - sync_vnode_count; 2425 mtx_unlock(&sync_mtx); 2426 error = SYSCTL_OUT(req, &len, sizeof(len)); 2427 return (error); 2428 } 2429 2430 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2431 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2432 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2433 2434 static struct proc *updateproc; 2435 static void sched_sync(void); 2436 static struct kproc_desc up_kp = { 2437 "syncer", 2438 sched_sync, 2439 &updateproc 2440 }; 2441 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2442 2443 static int 2444 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2445 { 2446 struct vnode *vp; 2447 struct mount *mp; 2448 2449 *bo = LIST_FIRST(slp); 2450 if (*bo == NULL) 2451 return (0); 2452 vp = bo2vnode(*bo); 2453 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2454 return (1); 2455 /* 2456 * We use vhold in case the vnode does not 2457 * successfully sync. vhold prevents the vnode from 2458 * going away when we unlock the sync_mtx so that 2459 * we can acquire the vnode interlock. 2460 */ 2461 vholdl(vp); 2462 mtx_unlock(&sync_mtx); 2463 VI_UNLOCK(vp); 2464 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2465 vdrop(vp); 2466 mtx_lock(&sync_mtx); 2467 return (*bo == LIST_FIRST(slp)); 2468 } 2469 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2470 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2471 VOP_UNLOCK(vp); 2472 vn_finished_write(mp); 2473 BO_LOCK(*bo); 2474 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2475 /* 2476 * Put us back on the worklist. The worklist 2477 * routine will remove us from our current 2478 * position and then add us back in at a later 2479 * position. 2480 */ 2481 vn_syncer_add_to_worklist(*bo, syncdelay); 2482 } 2483 BO_UNLOCK(*bo); 2484 vdrop(vp); 2485 mtx_lock(&sync_mtx); 2486 return (0); 2487 } 2488 2489 static int first_printf = 1; 2490 2491 /* 2492 * System filesystem synchronizer daemon. 2493 */ 2494 static void 2495 sched_sync(void) 2496 { 2497 struct synclist *next, *slp; 2498 struct bufobj *bo; 2499 long starttime; 2500 struct thread *td = curthread; 2501 int last_work_seen; 2502 int net_worklist_len; 2503 int syncer_final_iter; 2504 int error; 2505 2506 last_work_seen = 0; 2507 syncer_final_iter = 0; 2508 syncer_state = SYNCER_RUNNING; 2509 starttime = time_uptime; 2510 td->td_pflags |= TDP_NORUNNINGBUF; 2511 2512 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2513 SHUTDOWN_PRI_LAST); 2514 2515 mtx_lock(&sync_mtx); 2516 for (;;) { 2517 if (syncer_state == SYNCER_FINAL_DELAY && 2518 syncer_final_iter == 0) { 2519 mtx_unlock(&sync_mtx); 2520 kproc_suspend_check(td->td_proc); 2521 mtx_lock(&sync_mtx); 2522 } 2523 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2524 if (syncer_state != SYNCER_RUNNING && 2525 starttime != time_uptime) { 2526 if (first_printf) { 2527 printf("\nSyncing disks, vnodes remaining... "); 2528 first_printf = 0; 2529 } 2530 printf("%d ", net_worklist_len); 2531 } 2532 starttime = time_uptime; 2533 2534 /* 2535 * Push files whose dirty time has expired. Be careful 2536 * of interrupt race on slp queue. 2537 * 2538 * Skip over empty worklist slots when shutting down. 2539 */ 2540 do { 2541 slp = &syncer_workitem_pending[syncer_delayno]; 2542 syncer_delayno += 1; 2543 if (syncer_delayno == syncer_maxdelay) 2544 syncer_delayno = 0; 2545 next = &syncer_workitem_pending[syncer_delayno]; 2546 /* 2547 * If the worklist has wrapped since the 2548 * it was emptied of all but syncer vnodes, 2549 * switch to the FINAL_DELAY state and run 2550 * for one more second. 2551 */ 2552 if (syncer_state == SYNCER_SHUTTING_DOWN && 2553 net_worklist_len == 0 && 2554 last_work_seen == syncer_delayno) { 2555 syncer_state = SYNCER_FINAL_DELAY; 2556 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2557 } 2558 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2559 syncer_worklist_len > 0); 2560 2561 /* 2562 * Keep track of the last time there was anything 2563 * on the worklist other than syncer vnodes. 2564 * Return to the SHUTTING_DOWN state if any 2565 * new work appears. 2566 */ 2567 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2568 last_work_seen = syncer_delayno; 2569 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2570 syncer_state = SYNCER_SHUTTING_DOWN; 2571 while (!LIST_EMPTY(slp)) { 2572 error = sync_vnode(slp, &bo, td); 2573 if (error == 1) { 2574 LIST_REMOVE(bo, bo_synclist); 2575 LIST_INSERT_HEAD(next, bo, bo_synclist); 2576 continue; 2577 } 2578 2579 if (first_printf == 0) { 2580 /* 2581 * Drop the sync mutex, because some watchdog 2582 * drivers need to sleep while patting 2583 */ 2584 mtx_unlock(&sync_mtx); 2585 wdog_kern_pat(WD_LASTVAL); 2586 mtx_lock(&sync_mtx); 2587 } 2588 2589 } 2590 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2591 syncer_final_iter--; 2592 /* 2593 * The variable rushjob allows the kernel to speed up the 2594 * processing of the filesystem syncer process. A rushjob 2595 * value of N tells the filesystem syncer to process the next 2596 * N seconds worth of work on its queue ASAP. Currently rushjob 2597 * is used by the soft update code to speed up the filesystem 2598 * syncer process when the incore state is getting so far 2599 * ahead of the disk that the kernel memory pool is being 2600 * threatened with exhaustion. 2601 */ 2602 if (rushjob > 0) { 2603 rushjob -= 1; 2604 continue; 2605 } 2606 /* 2607 * Just sleep for a short period of time between 2608 * iterations when shutting down to allow some I/O 2609 * to happen. 2610 * 2611 * If it has taken us less than a second to process the 2612 * current work, then wait. Otherwise start right over 2613 * again. We can still lose time if any single round 2614 * takes more than two seconds, but it does not really 2615 * matter as we are just trying to generally pace the 2616 * filesystem activity. 2617 */ 2618 if (syncer_state != SYNCER_RUNNING || 2619 time_uptime == starttime) { 2620 thread_lock(td); 2621 sched_prio(td, PPAUSE); 2622 thread_unlock(td); 2623 } 2624 if (syncer_state != SYNCER_RUNNING) 2625 cv_timedwait(&sync_wakeup, &sync_mtx, 2626 hz / SYNCER_SHUTDOWN_SPEEDUP); 2627 else if (time_uptime == starttime) 2628 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2629 } 2630 } 2631 2632 /* 2633 * Request the syncer daemon to speed up its work. 2634 * We never push it to speed up more than half of its 2635 * normal turn time, otherwise it could take over the cpu. 2636 */ 2637 int 2638 speedup_syncer(void) 2639 { 2640 int ret = 0; 2641 2642 mtx_lock(&sync_mtx); 2643 if (rushjob < syncdelay / 2) { 2644 rushjob += 1; 2645 stat_rush_requests += 1; 2646 ret = 1; 2647 } 2648 mtx_unlock(&sync_mtx); 2649 cv_broadcast(&sync_wakeup); 2650 return (ret); 2651 } 2652 2653 /* 2654 * Tell the syncer to speed up its work and run though its work 2655 * list several times, then tell it to shut down. 2656 */ 2657 static void 2658 syncer_shutdown(void *arg, int howto) 2659 { 2660 2661 if (howto & RB_NOSYNC) 2662 return; 2663 mtx_lock(&sync_mtx); 2664 syncer_state = SYNCER_SHUTTING_DOWN; 2665 rushjob = 0; 2666 mtx_unlock(&sync_mtx); 2667 cv_broadcast(&sync_wakeup); 2668 kproc_shutdown(arg, howto); 2669 } 2670 2671 void 2672 syncer_suspend(void) 2673 { 2674 2675 syncer_shutdown(updateproc, 0); 2676 } 2677 2678 void 2679 syncer_resume(void) 2680 { 2681 2682 mtx_lock(&sync_mtx); 2683 first_printf = 1; 2684 syncer_state = SYNCER_RUNNING; 2685 mtx_unlock(&sync_mtx); 2686 cv_broadcast(&sync_wakeup); 2687 kproc_resume(updateproc); 2688 } 2689 2690 /* 2691 * Reassign a buffer from one vnode to another. 2692 * Used to assign file specific control information 2693 * (indirect blocks) to the vnode to which they belong. 2694 */ 2695 void 2696 reassignbuf(struct buf *bp) 2697 { 2698 struct vnode *vp; 2699 struct bufobj *bo; 2700 int delay; 2701 #ifdef INVARIANTS 2702 struct bufv *bv; 2703 #endif 2704 2705 vp = bp->b_vp; 2706 bo = bp->b_bufobj; 2707 ++reassignbufcalls; 2708 2709 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2710 bp, bp->b_vp, bp->b_flags); 2711 /* 2712 * B_PAGING flagged buffers cannot be reassigned because their vp 2713 * is not fully linked in. 2714 */ 2715 if (bp->b_flags & B_PAGING) 2716 panic("cannot reassign paging buffer"); 2717 2718 /* 2719 * Delete from old vnode list, if on one. 2720 */ 2721 BO_LOCK(bo); 2722 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2723 buf_vlist_remove(bp); 2724 else 2725 panic("reassignbuf: Buffer %p not on queue.", bp); 2726 /* 2727 * If dirty, put on list of dirty buffers; otherwise insert onto list 2728 * of clean buffers. 2729 */ 2730 if (bp->b_flags & B_DELWRI) { 2731 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2732 switch (vp->v_type) { 2733 case VDIR: 2734 delay = dirdelay; 2735 break; 2736 case VCHR: 2737 delay = metadelay; 2738 break; 2739 default: 2740 delay = filedelay; 2741 } 2742 vn_syncer_add_to_worklist(bo, delay); 2743 } 2744 buf_vlist_add(bp, bo, BX_VNDIRTY); 2745 } else { 2746 buf_vlist_add(bp, bo, BX_VNCLEAN); 2747 2748 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2749 mtx_lock(&sync_mtx); 2750 LIST_REMOVE(bo, bo_synclist); 2751 syncer_worklist_len--; 2752 mtx_unlock(&sync_mtx); 2753 bo->bo_flag &= ~BO_ONWORKLST; 2754 } 2755 } 2756 #ifdef INVARIANTS 2757 bv = &bo->bo_clean; 2758 bp = TAILQ_FIRST(&bv->bv_hd); 2759 KASSERT(bp == NULL || bp->b_bufobj == bo, 2760 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2761 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2762 KASSERT(bp == NULL || bp->b_bufobj == bo, 2763 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2764 bv = &bo->bo_dirty; 2765 bp = TAILQ_FIRST(&bv->bv_hd); 2766 KASSERT(bp == NULL || bp->b_bufobj == bo, 2767 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2768 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2769 KASSERT(bp == NULL || bp->b_bufobj == bo, 2770 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2771 #endif 2772 BO_UNLOCK(bo); 2773 } 2774 2775 static void 2776 v_init_counters(struct vnode *vp) 2777 { 2778 2779 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2780 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2781 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2782 2783 refcount_init(&vp->v_holdcnt, 1); 2784 refcount_init(&vp->v_usecount, 1); 2785 } 2786 2787 /* 2788 * Increment si_usecount of the associated device, if any. 2789 */ 2790 static void 2791 v_incr_devcount(struct vnode *vp) 2792 { 2793 2794 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2795 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2796 dev_lock(); 2797 vp->v_rdev->si_usecount++; 2798 dev_unlock(); 2799 } 2800 } 2801 2802 /* 2803 * Decrement si_usecount of the associated device, if any. 2804 * 2805 * The caller is required to hold the interlock when transitioning a VCHR use 2806 * count to zero. This prevents a race with devfs_reclaim_vchr() that would 2807 * leak a si_usecount reference. The vnode lock will also prevent this race 2808 * if it is held while dropping the last ref. 2809 * 2810 * The race is: 2811 * 2812 * CPU1 CPU2 2813 * devfs_reclaim_vchr 2814 * make v_usecount == 0 2815 * VI_LOCK 2816 * sees v_usecount == 0, no updates 2817 * vp->v_rdev = NULL; 2818 * ... 2819 * VI_UNLOCK 2820 * VI_LOCK 2821 * v_decr_devcount 2822 * sees v_rdev == NULL, no updates 2823 * 2824 * In this scenario si_devcount decrement is not performed. 2825 */ 2826 static void 2827 v_decr_devcount(struct vnode *vp) 2828 { 2829 2830 ASSERT_VOP_LOCKED(vp, __func__); 2831 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2832 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2833 dev_lock(); 2834 VNPASS(vp->v_rdev->si_usecount > 0, vp); 2835 vp->v_rdev->si_usecount--; 2836 dev_unlock(); 2837 } 2838 } 2839 2840 /* 2841 * Grab a particular vnode from the free list, increment its 2842 * reference count and lock it. VIRF_DOOMED is set if the vnode 2843 * is being destroyed. Only callers who specify LK_RETRY will 2844 * see doomed vnodes. If inactive processing was delayed in 2845 * vput try to do it here. 2846 * 2847 * usecount is manipulated using atomics without holding any locks. 2848 * 2849 * holdcnt can be manipulated using atomics without holding any locks, 2850 * except when transitioning 1<->0, in which case the interlock is held. 2851 */ 2852 enum vgetstate 2853 vget_prep(struct vnode *vp) 2854 { 2855 enum vgetstate vs; 2856 2857 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2858 vs = VGET_USECOUNT; 2859 } else { 2860 vhold(vp); 2861 vs = VGET_HOLDCNT; 2862 } 2863 return (vs); 2864 } 2865 2866 int 2867 vget(struct vnode *vp, int flags, struct thread *td) 2868 { 2869 enum vgetstate vs; 2870 2871 MPASS(td == curthread); 2872 2873 vs = vget_prep(vp); 2874 return (vget_finish(vp, flags, vs)); 2875 } 2876 2877 static int __noinline 2878 vget_finish_vchr(struct vnode *vp) 2879 { 2880 2881 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2882 2883 /* 2884 * See the comment in vget_finish before usecount bump. 2885 */ 2886 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2887 #ifdef INVARIANTS 2888 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2889 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 2890 #else 2891 refcount_release(&vp->v_holdcnt); 2892 #endif 2893 return (0); 2894 } 2895 2896 VI_LOCK(vp); 2897 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2898 #ifdef INVARIANTS 2899 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2900 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2901 #else 2902 refcount_release(&vp->v_holdcnt); 2903 #endif 2904 VI_UNLOCK(vp); 2905 return (0); 2906 } 2907 v_incr_devcount(vp); 2908 refcount_acquire(&vp->v_usecount); 2909 VI_UNLOCK(vp); 2910 return (0); 2911 } 2912 2913 int 2914 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2915 { 2916 int error, old; 2917 2918 if ((flags & LK_INTERLOCK) != 0) 2919 ASSERT_VI_LOCKED(vp, __func__); 2920 else 2921 ASSERT_VI_UNLOCKED(vp, __func__); 2922 VNPASS(vp->v_holdcnt > 0, vp); 2923 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2924 2925 error = vn_lock(vp, flags); 2926 if (__predict_false(error != 0)) { 2927 if (vs == VGET_USECOUNT) 2928 vrele(vp); 2929 else 2930 vdrop(vp); 2931 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2932 vp); 2933 return (error); 2934 } 2935 2936 if (vs == VGET_USECOUNT) 2937 return (0); 2938 2939 if (__predict_false(vp->v_type == VCHR)) 2940 return (vget_finish_vchr(vp)); 2941 2942 /* 2943 * We hold the vnode. If the usecount is 0 it will be utilized to keep 2944 * the vnode around. Otherwise someone else lended their hold count and 2945 * we have to drop ours. 2946 */ 2947 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2948 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 2949 if (old != 0) { 2950 #ifdef INVARIANTS 2951 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2952 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2953 #else 2954 refcount_release(&vp->v_holdcnt); 2955 #endif 2956 } 2957 return (0); 2958 } 2959 2960 /* 2961 * Increase the reference (use) and hold count of a vnode. 2962 * This will also remove the vnode from the free list if it is presently free. 2963 */ 2964 static void __noinline 2965 vref_vchr(struct vnode *vp, bool interlock) 2966 { 2967 2968 /* 2969 * See the comment in vget_finish before usecount bump. 2970 */ 2971 if (!interlock) { 2972 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2973 VNODE_REFCOUNT_FENCE_ACQ(); 2974 VNASSERT(vp->v_holdcnt > 0, vp, 2975 ("%s: active vnode not held", __func__)); 2976 return; 2977 } 2978 VI_LOCK(vp); 2979 /* 2980 * By the time we get here the vnode might have been doomed, at 2981 * which point the 0->1 use count transition is no longer 2982 * protected by the interlock. Since it can't bounce back to 2983 * VCHR and requires vref semantics, punt it back 2984 */ 2985 if (__predict_false(vp->v_type == VBAD)) { 2986 VI_UNLOCK(vp); 2987 vref(vp); 2988 return; 2989 } 2990 } 2991 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2992 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2993 VNODE_REFCOUNT_FENCE_ACQ(); 2994 VNASSERT(vp->v_holdcnt > 0, vp, 2995 ("%s: active vnode not held", __func__)); 2996 if (!interlock) 2997 VI_UNLOCK(vp); 2998 return; 2999 } 3000 vhold(vp); 3001 v_incr_devcount(vp); 3002 refcount_acquire(&vp->v_usecount); 3003 if (!interlock) 3004 VI_UNLOCK(vp); 3005 return; 3006 } 3007 3008 void 3009 vref(struct vnode *vp) 3010 { 3011 int old; 3012 3013 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3014 if (__predict_false(vp->v_type == VCHR)) { 3015 vref_vchr(vp, false); 3016 return; 3017 } 3018 3019 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3020 VNODE_REFCOUNT_FENCE_ACQ(); 3021 VNASSERT(vp->v_holdcnt > 0, vp, 3022 ("%s: active vnode not held", __func__)); 3023 return; 3024 } 3025 vhold(vp); 3026 /* 3027 * See the comment in vget_finish. 3028 */ 3029 old = atomic_fetchadd_int(&vp->v_usecount, 1); 3030 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 3031 if (old != 0) { 3032 #ifdef INVARIANTS 3033 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 3034 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 3035 #else 3036 refcount_release(&vp->v_holdcnt); 3037 #endif 3038 } 3039 } 3040 3041 void 3042 vrefl(struct vnode *vp) 3043 { 3044 3045 ASSERT_VI_LOCKED(vp, __func__); 3046 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3047 if (__predict_false(vp->v_type == VCHR)) { 3048 vref_vchr(vp, true); 3049 return; 3050 } 3051 vref(vp); 3052 } 3053 3054 void 3055 vrefact(struct vnode *vp) 3056 { 3057 3058 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3059 #ifdef INVARIANTS 3060 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 3061 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3062 #else 3063 refcount_acquire(&vp->v_usecount); 3064 #endif 3065 } 3066 3067 void 3068 vrefactn(struct vnode *vp, u_int n) 3069 { 3070 3071 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3072 #ifdef INVARIANTS 3073 int old = atomic_fetchadd_int(&vp->v_usecount, n); 3074 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3075 #else 3076 atomic_add_int(&vp->v_usecount, n); 3077 #endif 3078 } 3079 3080 /* 3081 * Return reference count of a vnode. 3082 * 3083 * The results of this call are only guaranteed when some mechanism is used to 3084 * stop other processes from gaining references to the vnode. This may be the 3085 * case if the caller holds the only reference. This is also useful when stale 3086 * data is acceptable as race conditions may be accounted for by some other 3087 * means. 3088 */ 3089 int 3090 vrefcnt(struct vnode *vp) 3091 { 3092 3093 return (vp->v_usecount); 3094 } 3095 3096 void 3097 vlazy(struct vnode *vp) 3098 { 3099 struct mount *mp; 3100 3101 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 3102 3103 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 3104 return; 3105 /* 3106 * We may get here for inactive routines after the vnode got doomed. 3107 */ 3108 if (VN_IS_DOOMED(vp)) 3109 return; 3110 mp = vp->v_mount; 3111 mtx_lock(&mp->mnt_listmtx); 3112 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 3113 vp->v_mflag |= VMP_LAZYLIST; 3114 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3115 mp->mnt_lazyvnodelistsize++; 3116 } 3117 mtx_unlock(&mp->mnt_listmtx); 3118 } 3119 3120 /* 3121 * This routine is only meant to be called from vgonel prior to dooming 3122 * the vnode. 3123 */ 3124 static void 3125 vunlazy_gone(struct vnode *vp) 3126 { 3127 struct mount *mp; 3128 3129 ASSERT_VOP_ELOCKED(vp, __func__); 3130 ASSERT_VI_LOCKED(vp, __func__); 3131 VNPASS(!VN_IS_DOOMED(vp), vp); 3132 3133 if (vp->v_mflag & VMP_LAZYLIST) { 3134 mp = vp->v_mount; 3135 mtx_lock(&mp->mnt_listmtx); 3136 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3137 vp->v_mflag &= ~VMP_LAZYLIST; 3138 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3139 mp->mnt_lazyvnodelistsize--; 3140 mtx_unlock(&mp->mnt_listmtx); 3141 } 3142 } 3143 3144 static void 3145 vdefer_inactive(struct vnode *vp) 3146 { 3147 3148 ASSERT_VI_LOCKED(vp, __func__); 3149 VNASSERT(vp->v_holdcnt > 0, vp, 3150 ("%s: vnode without hold count", __func__)); 3151 if (VN_IS_DOOMED(vp)) { 3152 vdropl(vp); 3153 return; 3154 } 3155 if (vp->v_iflag & VI_DEFINACT) { 3156 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3157 vdropl(vp); 3158 return; 3159 } 3160 if (vp->v_usecount > 0) { 3161 vp->v_iflag &= ~VI_OWEINACT; 3162 vdropl(vp); 3163 return; 3164 } 3165 vlazy(vp); 3166 vp->v_iflag |= VI_DEFINACT; 3167 VI_UNLOCK(vp); 3168 counter_u64_add(deferred_inact, 1); 3169 } 3170 3171 static void 3172 vdefer_inactive_unlocked(struct vnode *vp) 3173 { 3174 3175 VI_LOCK(vp); 3176 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3177 vdropl(vp); 3178 return; 3179 } 3180 vdefer_inactive(vp); 3181 } 3182 3183 enum vput_op { VRELE, VPUT, VUNREF }; 3184 3185 /* 3186 * Handle ->v_usecount transitioning to 0. 3187 * 3188 * By releasing the last usecount we take ownership of the hold count which 3189 * provides liveness of the vnode, meaning we have to vdrop. 3190 * 3191 * If the vnode is of type VCHR we may need to decrement si_usecount, see 3192 * v_decr_devcount for details. 3193 * 3194 * For all vnodes we may need to perform inactive processing. It requires an 3195 * exclusive lock on the vnode, while it is legal to call here with only a 3196 * shared lock (or no locks). If locking the vnode in an expected manner fails, 3197 * inactive processing gets deferred to the syncer. 3198 * 3199 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3200 * on the lock being held all the way until VOP_INACTIVE. This in particular 3201 * happens with UFS which adds half-constructed vnodes to the hash, where they 3202 * can be found by other code. 3203 */ 3204 static void 3205 vput_final(struct vnode *vp, enum vput_op func) 3206 { 3207 int error; 3208 bool want_unlock; 3209 3210 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3211 VNPASS(vp->v_holdcnt > 0, vp); 3212 3213 VI_LOCK(vp); 3214 if (__predict_false(vp->v_type == VCHR && func != VRELE)) 3215 v_decr_devcount(vp); 3216 3217 /* 3218 * By the time we got here someone else might have transitioned 3219 * the count back to > 0. 3220 */ 3221 if (vp->v_usecount > 0) 3222 goto out; 3223 3224 /* 3225 * If the vnode is doomed vgone already performed inactive processing 3226 * (if needed). 3227 */ 3228 if (VN_IS_DOOMED(vp)) 3229 goto out; 3230 3231 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0)) 3232 goto out; 3233 3234 if (vp->v_iflag & VI_DOINGINACT) 3235 goto out; 3236 3237 /* 3238 * Locking operations here will drop the interlock and possibly the 3239 * vnode lock, opening a window where the vnode can get doomed all the 3240 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to 3241 * perform inactive. 3242 */ 3243 vp->v_iflag |= VI_OWEINACT; 3244 want_unlock = false; 3245 error = 0; 3246 switch (func) { 3247 case VRELE: 3248 switch (VOP_ISLOCKED(vp)) { 3249 case LK_EXCLUSIVE: 3250 break; 3251 case LK_EXCLOTHER: 3252 case 0: 3253 want_unlock = true; 3254 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3255 VI_LOCK(vp); 3256 break; 3257 default: 3258 /* 3259 * The lock has at least one sharer, but we have no way 3260 * to conclude whether this is us. Play it safe and 3261 * defer processing. 3262 */ 3263 error = EAGAIN; 3264 break; 3265 } 3266 break; 3267 case VPUT: 3268 want_unlock = true; 3269 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3270 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3271 LK_NOWAIT); 3272 VI_LOCK(vp); 3273 } 3274 break; 3275 case VUNREF: 3276 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3277 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3278 VI_LOCK(vp); 3279 } 3280 break; 3281 } 3282 if (error == 0) { 3283 vinactive(vp); 3284 if (want_unlock) 3285 VOP_UNLOCK(vp); 3286 vdropl(vp); 3287 } else { 3288 vdefer_inactive(vp); 3289 } 3290 return; 3291 out: 3292 if (func == VPUT) 3293 VOP_UNLOCK(vp); 3294 vdropl(vp); 3295 } 3296 3297 /* 3298 * Decrement ->v_usecount for a vnode. 3299 * 3300 * Releasing the last use count requires additional processing, see vput_final 3301 * above for details. 3302 * 3303 * Note that releasing use count without the vnode lock requires special casing 3304 * for VCHR, see v_decr_devcount for details. 3305 * 3306 * Comment above each variant denotes lock state on entry and exit. 3307 */ 3308 3309 static void __noinline 3310 vrele_vchr(struct vnode *vp) 3311 { 3312 3313 if (refcount_release_if_not_last(&vp->v_usecount)) 3314 return; 3315 VI_LOCK(vp); 3316 if (!refcount_release(&vp->v_usecount)) { 3317 VI_UNLOCK(vp); 3318 return; 3319 } 3320 v_decr_devcount(vp); 3321 VI_UNLOCK(vp); 3322 vput_final(vp, VRELE); 3323 } 3324 3325 /* 3326 * in: any 3327 * out: same as passed in 3328 */ 3329 void 3330 vrele(struct vnode *vp) 3331 { 3332 3333 ASSERT_VI_UNLOCKED(vp, __func__); 3334 if (__predict_false(vp->v_type == VCHR)) { 3335 vrele_vchr(vp); 3336 return; 3337 } 3338 if (!refcount_release(&vp->v_usecount)) 3339 return; 3340 vput_final(vp, VRELE); 3341 } 3342 3343 /* 3344 * in: locked 3345 * out: unlocked 3346 */ 3347 void 3348 vput(struct vnode *vp) 3349 { 3350 3351 ASSERT_VOP_LOCKED(vp, __func__); 3352 ASSERT_VI_UNLOCKED(vp, __func__); 3353 if (!refcount_release(&vp->v_usecount)) { 3354 VOP_UNLOCK(vp); 3355 return; 3356 } 3357 vput_final(vp, VPUT); 3358 } 3359 3360 /* 3361 * in: locked 3362 * out: locked 3363 */ 3364 void 3365 vunref(struct vnode *vp) 3366 { 3367 3368 ASSERT_VOP_LOCKED(vp, __func__); 3369 ASSERT_VI_UNLOCKED(vp, __func__); 3370 if (!refcount_release(&vp->v_usecount)) 3371 return; 3372 vput_final(vp, VUNREF); 3373 } 3374 3375 void 3376 vhold(struct vnode *vp) 3377 { 3378 struct vdbatch *vd; 3379 int old; 3380 3381 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3382 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3383 VNASSERT(old >= 0, vp, ("%s: wrong hold count %d", __func__, old)); 3384 if (old != 0) 3385 return; 3386 critical_enter(); 3387 vd = DPCPU_PTR(vd); 3388 vd->freevnodes--; 3389 critical_exit(); 3390 } 3391 3392 void 3393 vholdl(struct vnode *vp) 3394 { 3395 3396 ASSERT_VI_LOCKED(vp, __func__); 3397 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3398 vhold(vp); 3399 } 3400 3401 void 3402 vholdnz(struct vnode *vp) 3403 { 3404 3405 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3406 #ifdef INVARIANTS 3407 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3408 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 3409 #else 3410 atomic_add_int(&vp->v_holdcnt, 1); 3411 #endif 3412 } 3413 3414 static void __noinline 3415 vdbatch_process(struct vdbatch *vd) 3416 { 3417 struct vnode *vp; 3418 int i; 3419 3420 mtx_assert(&vd->lock, MA_OWNED); 3421 MPASS(curthread->td_pinned > 0); 3422 MPASS(vd->index == VDBATCH_SIZE); 3423 3424 mtx_lock(&vnode_list_mtx); 3425 critical_enter(); 3426 freevnodes += vd->freevnodes; 3427 for (i = 0; i < VDBATCH_SIZE; i++) { 3428 vp = vd->tab[i]; 3429 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3430 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3431 MPASS(vp->v_dbatchcpu != NOCPU); 3432 vp->v_dbatchcpu = NOCPU; 3433 } 3434 mtx_unlock(&vnode_list_mtx); 3435 vd->freevnodes = 0; 3436 bzero(vd->tab, sizeof(vd->tab)); 3437 vd->index = 0; 3438 critical_exit(); 3439 } 3440 3441 static void 3442 vdbatch_enqueue(struct vnode *vp) 3443 { 3444 struct vdbatch *vd; 3445 3446 ASSERT_VI_LOCKED(vp, __func__); 3447 VNASSERT(!VN_IS_DOOMED(vp), vp, 3448 ("%s: deferring requeue of a doomed vnode", __func__)); 3449 3450 critical_enter(); 3451 vd = DPCPU_PTR(vd); 3452 vd->freevnodes++; 3453 if (vp->v_dbatchcpu != NOCPU) { 3454 VI_UNLOCK(vp); 3455 critical_exit(); 3456 return; 3457 } 3458 3459 sched_pin(); 3460 critical_exit(); 3461 mtx_lock(&vd->lock); 3462 MPASS(vd->index < VDBATCH_SIZE); 3463 MPASS(vd->tab[vd->index] == NULL); 3464 /* 3465 * A hack: we depend on being pinned so that we know what to put in 3466 * ->v_dbatchcpu. 3467 */ 3468 vp->v_dbatchcpu = curcpu; 3469 vd->tab[vd->index] = vp; 3470 vd->index++; 3471 VI_UNLOCK(vp); 3472 if (vd->index == VDBATCH_SIZE) 3473 vdbatch_process(vd); 3474 mtx_unlock(&vd->lock); 3475 sched_unpin(); 3476 } 3477 3478 /* 3479 * This routine must only be called for vnodes which are about to be 3480 * deallocated. Supporting dequeue for arbitrary vndoes would require 3481 * validating that the locked batch matches. 3482 */ 3483 static void 3484 vdbatch_dequeue(struct vnode *vp) 3485 { 3486 struct vdbatch *vd; 3487 int i; 3488 short cpu; 3489 3490 VNASSERT(vp->v_type == VBAD || vp->v_type == VNON, vp, 3491 ("%s: called for a used vnode\n", __func__)); 3492 3493 cpu = vp->v_dbatchcpu; 3494 if (cpu == NOCPU) 3495 return; 3496 3497 vd = DPCPU_ID_PTR(cpu, vd); 3498 mtx_lock(&vd->lock); 3499 for (i = 0; i < vd->index; i++) { 3500 if (vd->tab[i] != vp) 3501 continue; 3502 vp->v_dbatchcpu = NOCPU; 3503 vd->index--; 3504 vd->tab[i] = vd->tab[vd->index]; 3505 vd->tab[vd->index] = NULL; 3506 break; 3507 } 3508 mtx_unlock(&vd->lock); 3509 /* 3510 * Either we dequeued the vnode above or the target CPU beat us to it. 3511 */ 3512 MPASS(vp->v_dbatchcpu == NOCPU); 3513 } 3514 3515 /* 3516 * Drop the hold count of the vnode. If this is the last reference to 3517 * the vnode we place it on the free list unless it has been vgone'd 3518 * (marked VIRF_DOOMED) in which case we will free it. 3519 * 3520 * Because the vnode vm object keeps a hold reference on the vnode if 3521 * there is at least one resident non-cached page, the vnode cannot 3522 * leave the active list without the page cleanup done. 3523 */ 3524 static void 3525 vdrop_deactivate(struct vnode *vp) 3526 { 3527 struct mount *mp; 3528 3529 ASSERT_VI_LOCKED(vp, __func__); 3530 /* 3531 * Mark a vnode as free: remove it from its active list 3532 * and put it up for recycling on the freelist. 3533 */ 3534 VNASSERT(!VN_IS_DOOMED(vp), vp, 3535 ("vdrop: returning doomed vnode")); 3536 VNASSERT(vp->v_op != NULL, vp, 3537 ("vdrop: vnode already reclaimed.")); 3538 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 3539 ("vnode with VI_OWEINACT set")); 3540 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, 3541 ("vnode with VI_DEFINACT set")); 3542 if (vp->v_mflag & VMP_LAZYLIST) { 3543 mp = vp->v_mount; 3544 mtx_lock(&mp->mnt_listmtx); 3545 VNASSERT(vp->v_mflag & VMP_LAZYLIST, vp, ("lost VMP_LAZYLIST")); 3546 /* 3547 * Don't remove the vnode from the lazy list if another thread 3548 * has increased the hold count. It may have re-enqueued the 3549 * vnode to the lazy list and is now responsible for its 3550 * removal. 3551 */ 3552 if (vp->v_holdcnt == 0) { 3553 vp->v_mflag &= ~VMP_LAZYLIST; 3554 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3555 mp->mnt_lazyvnodelistsize--; 3556 } 3557 mtx_unlock(&mp->mnt_listmtx); 3558 } 3559 vdbatch_enqueue(vp); 3560 } 3561 3562 void 3563 vdrop(struct vnode *vp) 3564 { 3565 3566 ASSERT_VI_UNLOCKED(vp, __func__); 3567 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3568 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3569 return; 3570 VI_LOCK(vp); 3571 vdropl(vp); 3572 } 3573 3574 void 3575 vdropl(struct vnode *vp) 3576 { 3577 3578 ASSERT_VI_LOCKED(vp, __func__); 3579 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3580 if (!refcount_release(&vp->v_holdcnt)) { 3581 VI_UNLOCK(vp); 3582 return; 3583 } 3584 if (VN_IS_DOOMED(vp)) { 3585 freevnode(vp); 3586 return; 3587 } 3588 vdrop_deactivate(vp); 3589 } 3590 3591 /* 3592 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3593 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3594 */ 3595 static void 3596 vinactivef(struct vnode *vp) 3597 { 3598 struct vm_object *obj; 3599 3600 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3601 ASSERT_VI_LOCKED(vp, "vinactive"); 3602 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3603 ("vinactive: recursed on VI_DOINGINACT")); 3604 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3605 vp->v_iflag |= VI_DOINGINACT; 3606 vp->v_iflag &= ~VI_OWEINACT; 3607 VI_UNLOCK(vp); 3608 /* 3609 * Before moving off the active list, we must be sure that any 3610 * modified pages are converted into the vnode's dirty 3611 * buffers, since these will no longer be checked once the 3612 * vnode is on the inactive list. 3613 * 3614 * The write-out of the dirty pages is asynchronous. At the 3615 * point that VOP_INACTIVE() is called, there could still be 3616 * pending I/O and dirty pages in the object. 3617 */ 3618 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3619 vm_object_mightbedirty(obj)) { 3620 VM_OBJECT_WLOCK(obj); 3621 vm_object_page_clean(obj, 0, 0, 0); 3622 VM_OBJECT_WUNLOCK(obj); 3623 } 3624 VOP_INACTIVE(vp, curthread); 3625 VI_LOCK(vp); 3626 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3627 ("vinactive: lost VI_DOINGINACT")); 3628 vp->v_iflag &= ~VI_DOINGINACT; 3629 } 3630 3631 void 3632 vinactive(struct vnode *vp) 3633 { 3634 3635 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3636 ASSERT_VI_LOCKED(vp, "vinactive"); 3637 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3638 3639 if ((vp->v_iflag & VI_OWEINACT) == 0) 3640 return; 3641 if (vp->v_iflag & VI_DOINGINACT) 3642 return; 3643 if (vp->v_usecount > 0) { 3644 vp->v_iflag &= ~VI_OWEINACT; 3645 return; 3646 } 3647 vinactivef(vp); 3648 } 3649 3650 /* 3651 * Remove any vnodes in the vnode table belonging to mount point mp. 3652 * 3653 * If FORCECLOSE is not specified, there should not be any active ones, 3654 * return error if any are found (nb: this is a user error, not a 3655 * system error). If FORCECLOSE is specified, detach any active vnodes 3656 * that are found. 3657 * 3658 * If WRITECLOSE is set, only flush out regular file vnodes open for 3659 * writing. 3660 * 3661 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3662 * 3663 * `rootrefs' specifies the base reference count for the root vnode 3664 * of this filesystem. The root vnode is considered busy if its 3665 * v_usecount exceeds this value. On a successful return, vflush(, td) 3666 * will call vrele() on the root vnode exactly rootrefs times. 3667 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3668 * be zero. 3669 */ 3670 #ifdef DIAGNOSTIC 3671 static int busyprt = 0; /* print out busy vnodes */ 3672 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3673 #endif 3674 3675 int 3676 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3677 { 3678 struct vnode *vp, *mvp, *rootvp = NULL; 3679 struct vattr vattr; 3680 int busy = 0, error; 3681 3682 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3683 rootrefs, flags); 3684 if (rootrefs > 0) { 3685 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3686 ("vflush: bad args")); 3687 /* 3688 * Get the filesystem root vnode. We can vput() it 3689 * immediately, since with rootrefs > 0, it won't go away. 3690 */ 3691 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3692 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3693 __func__, error); 3694 return (error); 3695 } 3696 vput(rootvp); 3697 } 3698 loop: 3699 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3700 vholdl(vp); 3701 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3702 if (error) { 3703 vdrop(vp); 3704 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3705 goto loop; 3706 } 3707 /* 3708 * Skip over a vnodes marked VV_SYSTEM. 3709 */ 3710 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3711 VOP_UNLOCK(vp); 3712 vdrop(vp); 3713 continue; 3714 } 3715 /* 3716 * If WRITECLOSE is set, flush out unlinked but still open 3717 * files (even if open only for reading) and regular file 3718 * vnodes open for writing. 3719 */ 3720 if (flags & WRITECLOSE) { 3721 if (vp->v_object != NULL) { 3722 VM_OBJECT_WLOCK(vp->v_object); 3723 vm_object_page_clean(vp->v_object, 0, 0, 0); 3724 VM_OBJECT_WUNLOCK(vp->v_object); 3725 } 3726 error = VOP_FSYNC(vp, MNT_WAIT, td); 3727 if (error != 0) { 3728 VOP_UNLOCK(vp); 3729 vdrop(vp); 3730 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3731 return (error); 3732 } 3733 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3734 VI_LOCK(vp); 3735 3736 if ((vp->v_type == VNON || 3737 (error == 0 && vattr.va_nlink > 0)) && 3738 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3739 VOP_UNLOCK(vp); 3740 vdropl(vp); 3741 continue; 3742 } 3743 } else 3744 VI_LOCK(vp); 3745 /* 3746 * With v_usecount == 0, all we need to do is clear out the 3747 * vnode data structures and we are done. 3748 * 3749 * If FORCECLOSE is set, forcibly close the vnode. 3750 */ 3751 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3752 vgonel(vp); 3753 } else { 3754 busy++; 3755 #ifdef DIAGNOSTIC 3756 if (busyprt) 3757 vn_printf(vp, "vflush: busy vnode "); 3758 #endif 3759 } 3760 VOP_UNLOCK(vp); 3761 vdropl(vp); 3762 } 3763 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3764 /* 3765 * If just the root vnode is busy, and if its refcount 3766 * is equal to `rootrefs', then go ahead and kill it. 3767 */ 3768 VI_LOCK(rootvp); 3769 KASSERT(busy > 0, ("vflush: not busy")); 3770 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3771 ("vflush: usecount %d < rootrefs %d", 3772 rootvp->v_usecount, rootrefs)); 3773 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3774 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3775 vgone(rootvp); 3776 VOP_UNLOCK(rootvp); 3777 busy = 0; 3778 } else 3779 VI_UNLOCK(rootvp); 3780 } 3781 if (busy) { 3782 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3783 busy); 3784 return (EBUSY); 3785 } 3786 for (; rootrefs > 0; rootrefs--) 3787 vrele(rootvp); 3788 return (0); 3789 } 3790 3791 /* 3792 * Recycle an unused vnode to the front of the free list. 3793 */ 3794 int 3795 vrecycle(struct vnode *vp) 3796 { 3797 int recycled; 3798 3799 VI_LOCK(vp); 3800 recycled = vrecyclel(vp); 3801 VI_UNLOCK(vp); 3802 return (recycled); 3803 } 3804 3805 /* 3806 * vrecycle, with the vp interlock held. 3807 */ 3808 int 3809 vrecyclel(struct vnode *vp) 3810 { 3811 int recycled; 3812 3813 ASSERT_VOP_ELOCKED(vp, __func__); 3814 ASSERT_VI_LOCKED(vp, __func__); 3815 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3816 recycled = 0; 3817 if (vp->v_usecount == 0) { 3818 recycled = 1; 3819 vgonel(vp); 3820 } 3821 return (recycled); 3822 } 3823 3824 /* 3825 * Eliminate all activity associated with a vnode 3826 * in preparation for reuse. 3827 */ 3828 void 3829 vgone(struct vnode *vp) 3830 { 3831 VI_LOCK(vp); 3832 vgonel(vp); 3833 VI_UNLOCK(vp); 3834 } 3835 3836 static void 3837 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3838 struct vnode *lowervp __unused) 3839 { 3840 } 3841 3842 /* 3843 * Notify upper mounts about reclaimed or unlinked vnode. 3844 */ 3845 void 3846 vfs_notify_upper(struct vnode *vp, int event) 3847 { 3848 static struct vfsops vgonel_vfsops = { 3849 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3850 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3851 }; 3852 struct mount *mp, *ump, *mmp; 3853 3854 mp = vp->v_mount; 3855 if (mp == NULL) 3856 return; 3857 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3858 return; 3859 3860 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3861 mmp->mnt_op = &vgonel_vfsops; 3862 mmp->mnt_kern_flag |= MNTK_MARKER; 3863 MNT_ILOCK(mp); 3864 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3865 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3866 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3867 ump = TAILQ_NEXT(ump, mnt_upper_link); 3868 continue; 3869 } 3870 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3871 MNT_IUNLOCK(mp); 3872 switch (event) { 3873 case VFS_NOTIFY_UPPER_RECLAIM: 3874 VFS_RECLAIM_LOWERVP(ump, vp); 3875 break; 3876 case VFS_NOTIFY_UPPER_UNLINK: 3877 VFS_UNLINK_LOWERVP(ump, vp); 3878 break; 3879 default: 3880 KASSERT(0, ("invalid event %d", event)); 3881 break; 3882 } 3883 MNT_ILOCK(mp); 3884 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3885 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3886 } 3887 free(mmp, M_TEMP); 3888 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3889 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3890 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3891 wakeup(&mp->mnt_uppers); 3892 } 3893 MNT_IUNLOCK(mp); 3894 } 3895 3896 /* 3897 * vgone, with the vp interlock held. 3898 */ 3899 static void 3900 vgonel(struct vnode *vp) 3901 { 3902 struct thread *td; 3903 struct mount *mp; 3904 vm_object_t object; 3905 bool active, oweinact; 3906 3907 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3908 ASSERT_VI_LOCKED(vp, "vgonel"); 3909 VNASSERT(vp->v_holdcnt, vp, 3910 ("vgonel: vp %p has no reference.", vp)); 3911 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3912 td = curthread; 3913 3914 /* 3915 * Don't vgonel if we're already doomed. 3916 */ 3917 if (vp->v_irflag & VIRF_DOOMED) 3918 return; 3919 vunlazy_gone(vp); 3920 vp->v_irflag |= VIRF_DOOMED; 3921 3922 /* 3923 * Check to see if the vnode is in use. If so, we have to call 3924 * VOP_CLOSE() and VOP_INACTIVE(). 3925 */ 3926 active = vp->v_usecount > 0; 3927 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 3928 /* 3929 * If we need to do inactive VI_OWEINACT will be set. 3930 */ 3931 if (vp->v_iflag & VI_DEFINACT) { 3932 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3933 vp->v_iflag &= ~VI_DEFINACT; 3934 vdropl(vp); 3935 } else { 3936 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 3937 VI_UNLOCK(vp); 3938 } 3939 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3940 3941 /* 3942 * If purging an active vnode, it must be closed and 3943 * deactivated before being reclaimed. 3944 */ 3945 if (active) 3946 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3947 if (oweinact || active) { 3948 VI_LOCK(vp); 3949 vinactivef(vp); 3950 VI_UNLOCK(vp); 3951 } 3952 if (vp->v_type == VSOCK) 3953 vfs_unp_reclaim(vp); 3954 3955 /* 3956 * Clean out any buffers associated with the vnode. 3957 * If the flush fails, just toss the buffers. 3958 */ 3959 mp = NULL; 3960 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3961 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3962 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3963 while (vinvalbuf(vp, 0, 0, 0) != 0) 3964 ; 3965 } 3966 3967 BO_LOCK(&vp->v_bufobj); 3968 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3969 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3970 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3971 vp->v_bufobj.bo_clean.bv_cnt == 0, 3972 ("vp %p bufobj not invalidated", vp)); 3973 3974 /* 3975 * For VMIO bufobj, BO_DEAD is set later, or in 3976 * vm_object_terminate() after the object's page queue is 3977 * flushed. 3978 */ 3979 object = vp->v_bufobj.bo_object; 3980 if (object == NULL) 3981 vp->v_bufobj.bo_flag |= BO_DEAD; 3982 BO_UNLOCK(&vp->v_bufobj); 3983 3984 /* 3985 * Handle the VM part. Tmpfs handles v_object on its own (the 3986 * OBJT_VNODE check). Nullfs or other bypassing filesystems 3987 * should not touch the object borrowed from the lower vnode 3988 * (the handle check). 3989 */ 3990 if (object != NULL && object->type == OBJT_VNODE && 3991 object->handle == vp) 3992 vnode_destroy_vobject(vp); 3993 3994 /* 3995 * Reclaim the vnode. 3996 */ 3997 if (VOP_RECLAIM(vp, td)) 3998 panic("vgone: cannot reclaim"); 3999 if (mp != NULL) 4000 vn_finished_secondary_write(mp); 4001 VNASSERT(vp->v_object == NULL, vp, 4002 ("vop_reclaim left v_object vp=%p", vp)); 4003 /* 4004 * Clear the advisory locks and wake up waiting threads. 4005 */ 4006 (void)VOP_ADVLOCKPURGE(vp); 4007 vp->v_lockf = NULL; 4008 /* 4009 * Delete from old mount point vnode list. 4010 */ 4011 delmntque(vp); 4012 cache_purge(vp); 4013 /* 4014 * Done with purge, reset to the standard lock and invalidate 4015 * the vnode. 4016 */ 4017 VI_LOCK(vp); 4018 vp->v_vnlock = &vp->v_lock; 4019 vp->v_op = &dead_vnodeops; 4020 vp->v_type = VBAD; 4021 } 4022 4023 /* 4024 * Calculate the total number of references to a special device. 4025 */ 4026 int 4027 vcount(struct vnode *vp) 4028 { 4029 int count; 4030 4031 dev_lock(); 4032 count = vp->v_rdev->si_usecount; 4033 dev_unlock(); 4034 return (count); 4035 } 4036 4037 /* 4038 * Print out a description of a vnode. 4039 */ 4040 static const char * const typename[] = 4041 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 4042 "VMARKER"}; 4043 4044 void 4045 vn_printf(struct vnode *vp, const char *fmt, ...) 4046 { 4047 va_list ap; 4048 char buf[256], buf2[16]; 4049 u_long flags; 4050 4051 va_start(ap, fmt); 4052 vprintf(fmt, ap); 4053 va_end(ap); 4054 printf("%p: ", (void *)vp); 4055 printf("type %s\n", typename[vp->v_type]); 4056 printf(" usecount %d, writecount %d, refcount %d", 4057 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 4058 switch (vp->v_type) { 4059 case VDIR: 4060 printf(" mountedhere %p\n", vp->v_mountedhere); 4061 break; 4062 case VCHR: 4063 printf(" rdev %p\n", vp->v_rdev); 4064 break; 4065 case VSOCK: 4066 printf(" socket %p\n", vp->v_unpcb); 4067 break; 4068 case VFIFO: 4069 printf(" fifoinfo %p\n", vp->v_fifoinfo); 4070 break; 4071 default: 4072 printf("\n"); 4073 break; 4074 } 4075 buf[0] = '\0'; 4076 buf[1] = '\0'; 4077 if (vp->v_irflag & VIRF_DOOMED) 4078 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 4079 flags = vp->v_irflag & ~(VIRF_DOOMED); 4080 if (flags != 0) { 4081 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 4082 strlcat(buf, buf2, sizeof(buf)); 4083 } 4084 if (vp->v_vflag & VV_ROOT) 4085 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4086 if (vp->v_vflag & VV_ISTTY) 4087 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4088 if (vp->v_vflag & VV_NOSYNC) 4089 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4090 if (vp->v_vflag & VV_ETERNALDEV) 4091 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4092 if (vp->v_vflag & VV_CACHEDLABEL) 4093 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4094 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4095 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4096 if (vp->v_vflag & VV_COPYONWRITE) 4097 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4098 if (vp->v_vflag & VV_SYSTEM) 4099 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4100 if (vp->v_vflag & VV_PROCDEP) 4101 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4102 if (vp->v_vflag & VV_NOKNOTE) 4103 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 4104 if (vp->v_vflag & VV_DELETED) 4105 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4106 if (vp->v_vflag & VV_MD) 4107 strlcat(buf, "|VV_MD", sizeof(buf)); 4108 if (vp->v_vflag & VV_FORCEINSMQ) 4109 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4110 if (vp->v_vflag & VV_READLINK) 4111 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4112 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4113 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 4114 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 4115 if (flags != 0) { 4116 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4117 strlcat(buf, buf2, sizeof(buf)); 4118 } 4119 if (vp->v_iflag & VI_TEXT_REF) 4120 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 4121 if (vp->v_iflag & VI_MOUNT) 4122 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4123 if (vp->v_iflag & VI_DOINGINACT) 4124 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4125 if (vp->v_iflag & VI_OWEINACT) 4126 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4127 if (vp->v_iflag & VI_DEFINACT) 4128 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4129 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | 4130 VI_OWEINACT | VI_DEFINACT); 4131 if (flags != 0) { 4132 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4133 strlcat(buf, buf2, sizeof(buf)); 4134 } 4135 if (vp->v_mflag & VMP_LAZYLIST) 4136 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4137 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4138 if (flags != 0) { 4139 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4140 strlcat(buf, buf2, sizeof(buf)); 4141 } 4142 printf(" flags (%s)\n", buf + 1); 4143 if (mtx_owned(VI_MTX(vp))) 4144 printf(" VI_LOCKed"); 4145 if (vp->v_object != NULL) 4146 printf(" v_object %p ref %d pages %d " 4147 "cleanbuf %d dirtybuf %d\n", 4148 vp->v_object, vp->v_object->ref_count, 4149 vp->v_object->resident_page_count, 4150 vp->v_bufobj.bo_clean.bv_cnt, 4151 vp->v_bufobj.bo_dirty.bv_cnt); 4152 printf(" "); 4153 lockmgr_printinfo(vp->v_vnlock); 4154 if (vp->v_data != NULL) 4155 VOP_PRINT(vp); 4156 } 4157 4158 #ifdef DDB 4159 /* 4160 * List all of the locked vnodes in the system. 4161 * Called when debugging the kernel. 4162 */ 4163 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 4164 { 4165 struct mount *mp; 4166 struct vnode *vp; 4167 4168 /* 4169 * Note: because this is DDB, we can't obey the locking semantics 4170 * for these structures, which means we could catch an inconsistent 4171 * state and dereference a nasty pointer. Not much to be done 4172 * about that. 4173 */ 4174 db_printf("Locked vnodes\n"); 4175 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4176 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4177 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4178 vn_printf(vp, "vnode "); 4179 } 4180 } 4181 } 4182 4183 /* 4184 * Show details about the given vnode. 4185 */ 4186 DB_SHOW_COMMAND(vnode, db_show_vnode) 4187 { 4188 struct vnode *vp; 4189 4190 if (!have_addr) 4191 return; 4192 vp = (struct vnode *)addr; 4193 vn_printf(vp, "vnode "); 4194 } 4195 4196 /* 4197 * Show details about the given mount point. 4198 */ 4199 DB_SHOW_COMMAND(mount, db_show_mount) 4200 { 4201 struct mount *mp; 4202 struct vfsopt *opt; 4203 struct statfs *sp; 4204 struct vnode *vp; 4205 char buf[512]; 4206 uint64_t mflags; 4207 u_int flags; 4208 4209 if (!have_addr) { 4210 /* No address given, print short info about all mount points. */ 4211 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4212 db_printf("%p %s on %s (%s)\n", mp, 4213 mp->mnt_stat.f_mntfromname, 4214 mp->mnt_stat.f_mntonname, 4215 mp->mnt_stat.f_fstypename); 4216 if (db_pager_quit) 4217 break; 4218 } 4219 db_printf("\nMore info: show mount <addr>\n"); 4220 return; 4221 } 4222 4223 mp = (struct mount *)addr; 4224 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4225 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4226 4227 buf[0] = '\0'; 4228 mflags = mp->mnt_flag; 4229 #define MNT_FLAG(flag) do { \ 4230 if (mflags & (flag)) { \ 4231 if (buf[0] != '\0') \ 4232 strlcat(buf, ", ", sizeof(buf)); \ 4233 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4234 mflags &= ~(flag); \ 4235 } \ 4236 } while (0) 4237 MNT_FLAG(MNT_RDONLY); 4238 MNT_FLAG(MNT_SYNCHRONOUS); 4239 MNT_FLAG(MNT_NOEXEC); 4240 MNT_FLAG(MNT_NOSUID); 4241 MNT_FLAG(MNT_NFS4ACLS); 4242 MNT_FLAG(MNT_UNION); 4243 MNT_FLAG(MNT_ASYNC); 4244 MNT_FLAG(MNT_SUIDDIR); 4245 MNT_FLAG(MNT_SOFTDEP); 4246 MNT_FLAG(MNT_NOSYMFOLLOW); 4247 MNT_FLAG(MNT_GJOURNAL); 4248 MNT_FLAG(MNT_MULTILABEL); 4249 MNT_FLAG(MNT_ACLS); 4250 MNT_FLAG(MNT_NOATIME); 4251 MNT_FLAG(MNT_NOCLUSTERR); 4252 MNT_FLAG(MNT_NOCLUSTERW); 4253 MNT_FLAG(MNT_SUJ); 4254 MNT_FLAG(MNT_EXRDONLY); 4255 MNT_FLAG(MNT_EXPORTED); 4256 MNT_FLAG(MNT_DEFEXPORTED); 4257 MNT_FLAG(MNT_EXPORTANON); 4258 MNT_FLAG(MNT_EXKERB); 4259 MNT_FLAG(MNT_EXPUBLIC); 4260 MNT_FLAG(MNT_LOCAL); 4261 MNT_FLAG(MNT_QUOTA); 4262 MNT_FLAG(MNT_ROOTFS); 4263 MNT_FLAG(MNT_USER); 4264 MNT_FLAG(MNT_IGNORE); 4265 MNT_FLAG(MNT_UPDATE); 4266 MNT_FLAG(MNT_DELEXPORT); 4267 MNT_FLAG(MNT_RELOAD); 4268 MNT_FLAG(MNT_FORCE); 4269 MNT_FLAG(MNT_SNAPSHOT); 4270 MNT_FLAG(MNT_BYFSID); 4271 #undef MNT_FLAG 4272 if (mflags != 0) { 4273 if (buf[0] != '\0') 4274 strlcat(buf, ", ", sizeof(buf)); 4275 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4276 "0x%016jx", mflags); 4277 } 4278 db_printf(" mnt_flag = %s\n", buf); 4279 4280 buf[0] = '\0'; 4281 flags = mp->mnt_kern_flag; 4282 #define MNT_KERN_FLAG(flag) do { \ 4283 if (flags & (flag)) { \ 4284 if (buf[0] != '\0') \ 4285 strlcat(buf, ", ", sizeof(buf)); \ 4286 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4287 flags &= ~(flag); \ 4288 } \ 4289 } while (0) 4290 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4291 MNT_KERN_FLAG(MNTK_ASYNC); 4292 MNT_KERN_FLAG(MNTK_SOFTDEP); 4293 MNT_KERN_FLAG(MNTK_DRAINING); 4294 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4295 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4296 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4297 MNT_KERN_FLAG(MNTK_NO_IOPF); 4298 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 4299 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 4300 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 4301 MNT_KERN_FLAG(MNTK_MARKER); 4302 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4303 MNT_KERN_FLAG(MNTK_NOASYNC); 4304 MNT_KERN_FLAG(MNTK_UNMOUNT); 4305 MNT_KERN_FLAG(MNTK_MWAIT); 4306 MNT_KERN_FLAG(MNTK_SUSPEND); 4307 MNT_KERN_FLAG(MNTK_SUSPEND2); 4308 MNT_KERN_FLAG(MNTK_SUSPENDED); 4309 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4310 MNT_KERN_FLAG(MNTK_NOKNOTE); 4311 #undef MNT_KERN_FLAG 4312 if (flags != 0) { 4313 if (buf[0] != '\0') 4314 strlcat(buf, ", ", sizeof(buf)); 4315 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4316 "0x%08x", flags); 4317 } 4318 db_printf(" mnt_kern_flag = %s\n", buf); 4319 4320 db_printf(" mnt_opt = "); 4321 opt = TAILQ_FIRST(mp->mnt_opt); 4322 if (opt != NULL) { 4323 db_printf("%s", opt->name); 4324 opt = TAILQ_NEXT(opt, link); 4325 while (opt != NULL) { 4326 db_printf(", %s", opt->name); 4327 opt = TAILQ_NEXT(opt, link); 4328 } 4329 } 4330 db_printf("\n"); 4331 4332 sp = &mp->mnt_stat; 4333 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4334 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4335 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4336 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4337 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4338 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4339 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4340 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4341 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4342 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4343 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4344 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4345 4346 db_printf(" mnt_cred = { uid=%u ruid=%u", 4347 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4348 if (jailed(mp->mnt_cred)) 4349 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4350 db_printf(" }\n"); 4351 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4352 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4353 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4354 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4355 db_printf(" mnt_lazyvnodelistsize = %d\n", 4356 mp->mnt_lazyvnodelistsize); 4357 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4358 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4359 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4360 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4361 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4362 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4363 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4364 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4365 db_printf(" mnt_secondary_accwrites = %d\n", 4366 mp->mnt_secondary_accwrites); 4367 db_printf(" mnt_gjprovider = %s\n", 4368 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4369 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4370 4371 db_printf("\n\nList of active vnodes\n"); 4372 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4373 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4374 vn_printf(vp, "vnode "); 4375 if (db_pager_quit) 4376 break; 4377 } 4378 } 4379 db_printf("\n\nList of inactive vnodes\n"); 4380 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4381 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4382 vn_printf(vp, "vnode "); 4383 if (db_pager_quit) 4384 break; 4385 } 4386 } 4387 } 4388 #endif /* DDB */ 4389 4390 /* 4391 * Fill in a struct xvfsconf based on a struct vfsconf. 4392 */ 4393 static int 4394 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4395 { 4396 struct xvfsconf xvfsp; 4397 4398 bzero(&xvfsp, sizeof(xvfsp)); 4399 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4400 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4401 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4402 xvfsp.vfc_flags = vfsp->vfc_flags; 4403 /* 4404 * These are unused in userland, we keep them 4405 * to not break binary compatibility. 4406 */ 4407 xvfsp.vfc_vfsops = NULL; 4408 xvfsp.vfc_next = NULL; 4409 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4410 } 4411 4412 #ifdef COMPAT_FREEBSD32 4413 struct xvfsconf32 { 4414 uint32_t vfc_vfsops; 4415 char vfc_name[MFSNAMELEN]; 4416 int32_t vfc_typenum; 4417 int32_t vfc_refcount; 4418 int32_t vfc_flags; 4419 uint32_t vfc_next; 4420 }; 4421 4422 static int 4423 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4424 { 4425 struct xvfsconf32 xvfsp; 4426 4427 bzero(&xvfsp, sizeof(xvfsp)); 4428 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4429 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4430 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4431 xvfsp.vfc_flags = vfsp->vfc_flags; 4432 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4433 } 4434 #endif 4435 4436 /* 4437 * Top level filesystem related information gathering. 4438 */ 4439 static int 4440 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4441 { 4442 struct vfsconf *vfsp; 4443 int error; 4444 4445 error = 0; 4446 vfsconf_slock(); 4447 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4448 #ifdef COMPAT_FREEBSD32 4449 if (req->flags & SCTL_MASK32) 4450 error = vfsconf2x32(req, vfsp); 4451 else 4452 #endif 4453 error = vfsconf2x(req, vfsp); 4454 if (error) 4455 break; 4456 } 4457 vfsconf_sunlock(); 4458 return (error); 4459 } 4460 4461 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4462 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4463 "S,xvfsconf", "List of all configured filesystems"); 4464 4465 #ifndef BURN_BRIDGES 4466 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4467 4468 static int 4469 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4470 { 4471 int *name = (int *)arg1 - 1; /* XXX */ 4472 u_int namelen = arg2 + 1; /* XXX */ 4473 struct vfsconf *vfsp; 4474 4475 log(LOG_WARNING, "userland calling deprecated sysctl, " 4476 "please rebuild world\n"); 4477 4478 #if 1 || defined(COMPAT_PRELITE2) 4479 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4480 if (namelen == 1) 4481 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4482 #endif 4483 4484 switch (name[1]) { 4485 case VFS_MAXTYPENUM: 4486 if (namelen != 2) 4487 return (ENOTDIR); 4488 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4489 case VFS_CONF: 4490 if (namelen != 3) 4491 return (ENOTDIR); /* overloaded */ 4492 vfsconf_slock(); 4493 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4494 if (vfsp->vfc_typenum == name[2]) 4495 break; 4496 } 4497 vfsconf_sunlock(); 4498 if (vfsp == NULL) 4499 return (EOPNOTSUPP); 4500 #ifdef COMPAT_FREEBSD32 4501 if (req->flags & SCTL_MASK32) 4502 return (vfsconf2x32(req, vfsp)); 4503 else 4504 #endif 4505 return (vfsconf2x(req, vfsp)); 4506 } 4507 return (EOPNOTSUPP); 4508 } 4509 4510 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4511 CTLFLAG_MPSAFE, vfs_sysctl, 4512 "Generic filesystem"); 4513 4514 #if 1 || defined(COMPAT_PRELITE2) 4515 4516 static int 4517 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4518 { 4519 int error; 4520 struct vfsconf *vfsp; 4521 struct ovfsconf ovfs; 4522 4523 vfsconf_slock(); 4524 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4525 bzero(&ovfs, sizeof(ovfs)); 4526 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4527 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4528 ovfs.vfc_index = vfsp->vfc_typenum; 4529 ovfs.vfc_refcount = vfsp->vfc_refcount; 4530 ovfs.vfc_flags = vfsp->vfc_flags; 4531 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4532 if (error != 0) { 4533 vfsconf_sunlock(); 4534 return (error); 4535 } 4536 } 4537 vfsconf_sunlock(); 4538 return (0); 4539 } 4540 4541 #endif /* 1 || COMPAT_PRELITE2 */ 4542 #endif /* !BURN_BRIDGES */ 4543 4544 #define KINFO_VNODESLOP 10 4545 #ifdef notyet 4546 /* 4547 * Dump vnode list (via sysctl). 4548 */ 4549 /* ARGSUSED */ 4550 static int 4551 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4552 { 4553 struct xvnode *xvn; 4554 struct mount *mp; 4555 struct vnode *vp; 4556 int error, len, n; 4557 4558 /* 4559 * Stale numvnodes access is not fatal here. 4560 */ 4561 req->lock = 0; 4562 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4563 if (!req->oldptr) 4564 /* Make an estimate */ 4565 return (SYSCTL_OUT(req, 0, len)); 4566 4567 error = sysctl_wire_old_buffer(req, 0); 4568 if (error != 0) 4569 return (error); 4570 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4571 n = 0; 4572 mtx_lock(&mountlist_mtx); 4573 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4574 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4575 continue; 4576 MNT_ILOCK(mp); 4577 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4578 if (n == len) 4579 break; 4580 vref(vp); 4581 xvn[n].xv_size = sizeof *xvn; 4582 xvn[n].xv_vnode = vp; 4583 xvn[n].xv_id = 0; /* XXX compat */ 4584 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4585 XV_COPY(usecount); 4586 XV_COPY(writecount); 4587 XV_COPY(holdcnt); 4588 XV_COPY(mount); 4589 XV_COPY(numoutput); 4590 XV_COPY(type); 4591 #undef XV_COPY 4592 xvn[n].xv_flag = vp->v_vflag; 4593 4594 switch (vp->v_type) { 4595 case VREG: 4596 case VDIR: 4597 case VLNK: 4598 break; 4599 case VBLK: 4600 case VCHR: 4601 if (vp->v_rdev == NULL) { 4602 vrele(vp); 4603 continue; 4604 } 4605 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4606 break; 4607 case VSOCK: 4608 xvn[n].xv_socket = vp->v_socket; 4609 break; 4610 case VFIFO: 4611 xvn[n].xv_fifo = vp->v_fifoinfo; 4612 break; 4613 case VNON: 4614 case VBAD: 4615 default: 4616 /* shouldn't happen? */ 4617 vrele(vp); 4618 continue; 4619 } 4620 vrele(vp); 4621 ++n; 4622 } 4623 MNT_IUNLOCK(mp); 4624 mtx_lock(&mountlist_mtx); 4625 vfs_unbusy(mp); 4626 if (n == len) 4627 break; 4628 } 4629 mtx_unlock(&mountlist_mtx); 4630 4631 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4632 free(xvn, M_TEMP); 4633 return (error); 4634 } 4635 4636 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4637 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4638 ""); 4639 #endif 4640 4641 static void 4642 unmount_or_warn(struct mount *mp) 4643 { 4644 int error; 4645 4646 error = dounmount(mp, MNT_FORCE, curthread); 4647 if (error != 0) { 4648 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4649 if (error == EBUSY) 4650 printf("BUSY)\n"); 4651 else 4652 printf("%d)\n", error); 4653 } 4654 } 4655 4656 /* 4657 * Unmount all filesystems. The list is traversed in reverse order 4658 * of mounting to avoid dependencies. 4659 */ 4660 void 4661 vfs_unmountall(void) 4662 { 4663 struct mount *mp, *tmp; 4664 4665 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4666 4667 /* 4668 * Since this only runs when rebooting, it is not interlocked. 4669 */ 4670 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4671 vfs_ref(mp); 4672 4673 /* 4674 * Forcibly unmounting "/dev" before "/" would prevent clean 4675 * unmount of the latter. 4676 */ 4677 if (mp == rootdevmp) 4678 continue; 4679 4680 unmount_or_warn(mp); 4681 } 4682 4683 if (rootdevmp != NULL) 4684 unmount_or_warn(rootdevmp); 4685 } 4686 4687 static void 4688 vfs_deferred_inactive(struct vnode *vp, int lkflags) 4689 { 4690 4691 ASSERT_VI_LOCKED(vp, __func__); 4692 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, ("VI_DEFINACT still set")); 4693 if ((vp->v_iflag & VI_OWEINACT) == 0) { 4694 vdropl(vp); 4695 return; 4696 } 4697 if (vn_lock(vp, lkflags) == 0) { 4698 VI_LOCK(vp); 4699 vinactive(vp); 4700 VOP_UNLOCK(vp); 4701 vdropl(vp); 4702 return; 4703 } 4704 vdefer_inactive_unlocked(vp); 4705 } 4706 4707 static int 4708 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 4709 { 4710 4711 return (vp->v_iflag & VI_DEFINACT); 4712 } 4713 4714 static void __noinline 4715 vfs_periodic_inactive(struct mount *mp, int flags) 4716 { 4717 struct vnode *vp, *mvp; 4718 int lkflags; 4719 4720 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4721 if (flags != MNT_WAIT) 4722 lkflags |= LK_NOWAIT; 4723 4724 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 4725 if ((vp->v_iflag & VI_DEFINACT) == 0) { 4726 VI_UNLOCK(vp); 4727 continue; 4728 } 4729 vp->v_iflag &= ~VI_DEFINACT; 4730 vfs_deferred_inactive(vp, lkflags); 4731 } 4732 } 4733 4734 static inline bool 4735 vfs_want_msync(struct vnode *vp) 4736 { 4737 struct vm_object *obj; 4738 4739 /* 4740 * This test may be performed without any locks held. 4741 * We rely on vm_object's type stability. 4742 */ 4743 if (vp->v_vflag & VV_NOSYNC) 4744 return (false); 4745 obj = vp->v_object; 4746 return (obj != NULL && vm_object_mightbedirty(obj)); 4747 } 4748 4749 static int 4750 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 4751 { 4752 4753 if (vp->v_vflag & VV_NOSYNC) 4754 return (false); 4755 if (vp->v_iflag & VI_DEFINACT) 4756 return (true); 4757 return (vfs_want_msync(vp)); 4758 } 4759 4760 static void __noinline 4761 vfs_periodic_msync_inactive(struct mount *mp, int flags) 4762 { 4763 struct vnode *vp, *mvp; 4764 struct vm_object *obj; 4765 struct thread *td; 4766 int lkflags, objflags; 4767 bool seen_defer; 4768 4769 td = curthread; 4770 4771 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4772 if (flags != MNT_WAIT) { 4773 lkflags |= LK_NOWAIT; 4774 objflags = OBJPC_NOSYNC; 4775 } else { 4776 objflags = OBJPC_SYNC; 4777 } 4778 4779 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 4780 seen_defer = false; 4781 if (vp->v_iflag & VI_DEFINACT) { 4782 vp->v_iflag &= ~VI_DEFINACT; 4783 seen_defer = true; 4784 } 4785 if (!vfs_want_msync(vp)) { 4786 if (seen_defer) 4787 vfs_deferred_inactive(vp, lkflags); 4788 else 4789 VI_UNLOCK(vp); 4790 continue; 4791 } 4792 if (vget(vp, lkflags, td) == 0) { 4793 obj = vp->v_object; 4794 if (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0) { 4795 VM_OBJECT_WLOCK(obj); 4796 vm_object_page_clean(obj, 0, 0, objflags); 4797 VM_OBJECT_WUNLOCK(obj); 4798 } 4799 vput(vp); 4800 if (seen_defer) 4801 vdrop(vp); 4802 } else { 4803 if (seen_defer) 4804 vdefer_inactive_unlocked(vp); 4805 } 4806 } 4807 } 4808 4809 void 4810 vfs_periodic(struct mount *mp, int flags) 4811 { 4812 4813 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4814 4815 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4816 vfs_periodic_inactive(mp, flags); 4817 else 4818 vfs_periodic_msync_inactive(mp, flags); 4819 } 4820 4821 static void 4822 destroy_vpollinfo_free(struct vpollinfo *vi) 4823 { 4824 4825 knlist_destroy(&vi->vpi_selinfo.si_note); 4826 mtx_destroy(&vi->vpi_lock); 4827 uma_zfree(vnodepoll_zone, vi); 4828 } 4829 4830 static void 4831 destroy_vpollinfo(struct vpollinfo *vi) 4832 { 4833 4834 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4835 seldrain(&vi->vpi_selinfo); 4836 destroy_vpollinfo_free(vi); 4837 } 4838 4839 /* 4840 * Initialize per-vnode helper structure to hold poll-related state. 4841 */ 4842 void 4843 v_addpollinfo(struct vnode *vp) 4844 { 4845 struct vpollinfo *vi; 4846 4847 if (vp->v_pollinfo != NULL) 4848 return; 4849 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4850 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4851 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4852 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4853 VI_LOCK(vp); 4854 if (vp->v_pollinfo != NULL) { 4855 VI_UNLOCK(vp); 4856 destroy_vpollinfo_free(vi); 4857 return; 4858 } 4859 vp->v_pollinfo = vi; 4860 VI_UNLOCK(vp); 4861 } 4862 4863 /* 4864 * Record a process's interest in events which might happen to 4865 * a vnode. Because poll uses the historic select-style interface 4866 * internally, this routine serves as both the ``check for any 4867 * pending events'' and the ``record my interest in future events'' 4868 * functions. (These are done together, while the lock is held, 4869 * to avoid race conditions.) 4870 */ 4871 int 4872 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4873 { 4874 4875 v_addpollinfo(vp); 4876 mtx_lock(&vp->v_pollinfo->vpi_lock); 4877 if (vp->v_pollinfo->vpi_revents & events) { 4878 /* 4879 * This leaves events we are not interested 4880 * in available for the other process which 4881 * which presumably had requested them 4882 * (otherwise they would never have been 4883 * recorded). 4884 */ 4885 events &= vp->v_pollinfo->vpi_revents; 4886 vp->v_pollinfo->vpi_revents &= ~events; 4887 4888 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4889 return (events); 4890 } 4891 vp->v_pollinfo->vpi_events |= events; 4892 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4893 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4894 return (0); 4895 } 4896 4897 /* 4898 * Routine to create and manage a filesystem syncer vnode. 4899 */ 4900 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4901 static int sync_fsync(struct vop_fsync_args *); 4902 static int sync_inactive(struct vop_inactive_args *); 4903 static int sync_reclaim(struct vop_reclaim_args *); 4904 4905 static struct vop_vector sync_vnodeops = { 4906 .vop_bypass = VOP_EOPNOTSUPP, 4907 .vop_close = sync_close, /* close */ 4908 .vop_fsync = sync_fsync, /* fsync */ 4909 .vop_inactive = sync_inactive, /* inactive */ 4910 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 4911 .vop_reclaim = sync_reclaim, /* reclaim */ 4912 .vop_lock1 = vop_stdlock, /* lock */ 4913 .vop_unlock = vop_stdunlock, /* unlock */ 4914 .vop_islocked = vop_stdislocked, /* islocked */ 4915 }; 4916 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 4917 4918 /* 4919 * Create a new filesystem syncer vnode for the specified mount point. 4920 */ 4921 void 4922 vfs_allocate_syncvnode(struct mount *mp) 4923 { 4924 struct vnode *vp; 4925 struct bufobj *bo; 4926 static long start, incr, next; 4927 int error; 4928 4929 /* Allocate a new vnode */ 4930 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4931 if (error != 0) 4932 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4933 vp->v_type = VNON; 4934 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4935 vp->v_vflag |= VV_FORCEINSMQ; 4936 error = insmntque(vp, mp); 4937 if (error != 0) 4938 panic("vfs_allocate_syncvnode: insmntque() failed"); 4939 vp->v_vflag &= ~VV_FORCEINSMQ; 4940 VOP_UNLOCK(vp); 4941 /* 4942 * Place the vnode onto the syncer worklist. We attempt to 4943 * scatter them about on the list so that they will go off 4944 * at evenly distributed times even if all the filesystems 4945 * are mounted at once. 4946 */ 4947 next += incr; 4948 if (next == 0 || next > syncer_maxdelay) { 4949 start /= 2; 4950 incr /= 2; 4951 if (start == 0) { 4952 start = syncer_maxdelay / 2; 4953 incr = syncer_maxdelay; 4954 } 4955 next = start; 4956 } 4957 bo = &vp->v_bufobj; 4958 BO_LOCK(bo); 4959 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4960 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4961 mtx_lock(&sync_mtx); 4962 sync_vnode_count++; 4963 if (mp->mnt_syncer == NULL) { 4964 mp->mnt_syncer = vp; 4965 vp = NULL; 4966 } 4967 mtx_unlock(&sync_mtx); 4968 BO_UNLOCK(bo); 4969 if (vp != NULL) { 4970 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4971 vgone(vp); 4972 vput(vp); 4973 } 4974 } 4975 4976 void 4977 vfs_deallocate_syncvnode(struct mount *mp) 4978 { 4979 struct vnode *vp; 4980 4981 mtx_lock(&sync_mtx); 4982 vp = mp->mnt_syncer; 4983 if (vp != NULL) 4984 mp->mnt_syncer = NULL; 4985 mtx_unlock(&sync_mtx); 4986 if (vp != NULL) 4987 vrele(vp); 4988 } 4989 4990 /* 4991 * Do a lazy sync of the filesystem. 4992 */ 4993 static int 4994 sync_fsync(struct vop_fsync_args *ap) 4995 { 4996 struct vnode *syncvp = ap->a_vp; 4997 struct mount *mp = syncvp->v_mount; 4998 int error, save; 4999 struct bufobj *bo; 5000 5001 /* 5002 * We only need to do something if this is a lazy evaluation. 5003 */ 5004 if (ap->a_waitfor != MNT_LAZY) 5005 return (0); 5006 5007 /* 5008 * Move ourselves to the back of the sync list. 5009 */ 5010 bo = &syncvp->v_bufobj; 5011 BO_LOCK(bo); 5012 vn_syncer_add_to_worklist(bo, syncdelay); 5013 BO_UNLOCK(bo); 5014 5015 /* 5016 * Walk the list of vnodes pushing all that are dirty and 5017 * not already on the sync list. 5018 */ 5019 if (vfs_busy(mp, MBF_NOWAIT) != 0) 5020 return (0); 5021 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 5022 vfs_unbusy(mp); 5023 return (0); 5024 } 5025 save = curthread_pflags_set(TDP_SYNCIO); 5026 /* 5027 * The filesystem at hand may be idle with free vnodes stored in the 5028 * batch. Return them instead of letting them stay there indefinitely. 5029 */ 5030 vfs_periodic(mp, MNT_NOWAIT); 5031 error = VFS_SYNC(mp, MNT_LAZY); 5032 curthread_pflags_restore(save); 5033 vn_finished_write(mp); 5034 vfs_unbusy(mp); 5035 return (error); 5036 } 5037 5038 /* 5039 * The syncer vnode is no referenced. 5040 */ 5041 static int 5042 sync_inactive(struct vop_inactive_args *ap) 5043 { 5044 5045 vgone(ap->a_vp); 5046 return (0); 5047 } 5048 5049 /* 5050 * The syncer vnode is no longer needed and is being decommissioned. 5051 * 5052 * Modifications to the worklist must be protected by sync_mtx. 5053 */ 5054 static int 5055 sync_reclaim(struct vop_reclaim_args *ap) 5056 { 5057 struct vnode *vp = ap->a_vp; 5058 struct bufobj *bo; 5059 5060 bo = &vp->v_bufobj; 5061 BO_LOCK(bo); 5062 mtx_lock(&sync_mtx); 5063 if (vp->v_mount->mnt_syncer == vp) 5064 vp->v_mount->mnt_syncer = NULL; 5065 if (bo->bo_flag & BO_ONWORKLST) { 5066 LIST_REMOVE(bo, bo_synclist); 5067 syncer_worklist_len--; 5068 sync_vnode_count--; 5069 bo->bo_flag &= ~BO_ONWORKLST; 5070 } 5071 mtx_unlock(&sync_mtx); 5072 BO_UNLOCK(bo); 5073 5074 return (0); 5075 } 5076 5077 int 5078 vn_need_pageq_flush(struct vnode *vp) 5079 { 5080 struct vm_object *obj; 5081 int need; 5082 5083 MPASS(mtx_owned(VI_MTX(vp))); 5084 need = 0; 5085 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5086 vm_object_mightbedirty(obj)) 5087 need = 1; 5088 return (need); 5089 } 5090 5091 /* 5092 * Check if vnode represents a disk device 5093 */ 5094 int 5095 vn_isdisk(struct vnode *vp, int *errp) 5096 { 5097 int error; 5098 5099 if (vp->v_type != VCHR) { 5100 error = ENOTBLK; 5101 goto out; 5102 } 5103 error = 0; 5104 dev_lock(); 5105 if (vp->v_rdev == NULL) 5106 error = ENXIO; 5107 else if (vp->v_rdev->si_devsw == NULL) 5108 error = ENXIO; 5109 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5110 error = ENOTBLK; 5111 dev_unlock(); 5112 out: 5113 if (errp != NULL) 5114 *errp = error; 5115 return (error == 0); 5116 } 5117 5118 /* 5119 * Common filesystem object access control check routine. Accepts a 5120 * vnode's type, "mode", uid and gid, requested access mode, credentials, 5121 * and optional call-by-reference privused argument allowing vaccess() 5122 * to indicate to the caller whether privilege was used to satisfy the 5123 * request (obsoleted). Returns 0 on success, or an errno on failure. 5124 */ 5125 int 5126 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5127 accmode_t accmode, struct ucred *cred, int *privused) 5128 { 5129 accmode_t dac_granted; 5130 accmode_t priv_granted; 5131 5132 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5133 ("invalid bit in accmode")); 5134 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5135 ("VAPPEND without VWRITE")); 5136 5137 /* 5138 * Look for a normal, non-privileged way to access the file/directory 5139 * as requested. If it exists, go with that. 5140 */ 5141 5142 if (privused != NULL) 5143 *privused = 0; 5144 5145 dac_granted = 0; 5146 5147 /* Check the owner. */ 5148 if (cred->cr_uid == file_uid) { 5149 dac_granted |= VADMIN; 5150 if (file_mode & S_IXUSR) 5151 dac_granted |= VEXEC; 5152 if (file_mode & S_IRUSR) 5153 dac_granted |= VREAD; 5154 if (file_mode & S_IWUSR) 5155 dac_granted |= (VWRITE | VAPPEND); 5156 5157 if ((accmode & dac_granted) == accmode) 5158 return (0); 5159 5160 goto privcheck; 5161 } 5162 5163 /* Otherwise, check the groups (first match) */ 5164 if (groupmember(file_gid, cred)) { 5165 if (file_mode & S_IXGRP) 5166 dac_granted |= VEXEC; 5167 if (file_mode & S_IRGRP) 5168 dac_granted |= VREAD; 5169 if (file_mode & S_IWGRP) 5170 dac_granted |= (VWRITE | VAPPEND); 5171 5172 if ((accmode & dac_granted) == accmode) 5173 return (0); 5174 5175 goto privcheck; 5176 } 5177 5178 /* Otherwise, check everyone else. */ 5179 if (file_mode & S_IXOTH) 5180 dac_granted |= VEXEC; 5181 if (file_mode & S_IROTH) 5182 dac_granted |= VREAD; 5183 if (file_mode & S_IWOTH) 5184 dac_granted |= (VWRITE | VAPPEND); 5185 if ((accmode & dac_granted) == accmode) 5186 return (0); 5187 5188 privcheck: 5189 /* 5190 * Build a privilege mask to determine if the set of privileges 5191 * satisfies the requirements when combined with the granted mask 5192 * from above. For each privilege, if the privilege is required, 5193 * bitwise or the request type onto the priv_granted mask. 5194 */ 5195 priv_granted = 0; 5196 5197 if (type == VDIR) { 5198 /* 5199 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5200 * requests, instead of PRIV_VFS_EXEC. 5201 */ 5202 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5203 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5204 priv_granted |= VEXEC; 5205 } else { 5206 /* 5207 * Ensure that at least one execute bit is on. Otherwise, 5208 * a privileged user will always succeed, and we don't want 5209 * this to happen unless the file really is executable. 5210 */ 5211 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5212 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5213 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5214 priv_granted |= VEXEC; 5215 } 5216 5217 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5218 !priv_check_cred(cred, PRIV_VFS_READ)) 5219 priv_granted |= VREAD; 5220 5221 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5222 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5223 priv_granted |= (VWRITE | VAPPEND); 5224 5225 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5226 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5227 priv_granted |= VADMIN; 5228 5229 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5230 /* XXX audit: privilege used */ 5231 if (privused != NULL) 5232 *privused = 1; 5233 return (0); 5234 } 5235 5236 return ((accmode & VADMIN) ? EPERM : EACCES); 5237 } 5238 5239 /* 5240 * Credential check based on process requesting service, and per-attribute 5241 * permissions. 5242 */ 5243 int 5244 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5245 struct thread *td, accmode_t accmode) 5246 { 5247 5248 /* 5249 * Kernel-invoked always succeeds. 5250 */ 5251 if (cred == NOCRED) 5252 return (0); 5253 5254 /* 5255 * Do not allow privileged processes in jail to directly manipulate 5256 * system attributes. 5257 */ 5258 switch (attrnamespace) { 5259 case EXTATTR_NAMESPACE_SYSTEM: 5260 /* Potentially should be: return (EPERM); */ 5261 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5262 case EXTATTR_NAMESPACE_USER: 5263 return (VOP_ACCESS(vp, accmode, cred, td)); 5264 default: 5265 return (EPERM); 5266 } 5267 } 5268 5269 #ifdef DEBUG_VFS_LOCKS 5270 /* 5271 * This only exists to suppress warnings from unlocked specfs accesses. It is 5272 * no longer ok to have an unlocked VFS. 5273 */ 5274 #define IGNORE_LOCK(vp) (KERNEL_PANICKED() || (vp) == NULL || \ 5275 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 5276 5277 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5278 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5279 "Drop into debugger on lock violation"); 5280 5281 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5282 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5283 0, "Check for interlock across VOPs"); 5284 5285 int vfs_badlock_print = 1; /* Print lock violations. */ 5286 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5287 0, "Print lock violations"); 5288 5289 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5290 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5291 0, "Print vnode details on lock violations"); 5292 5293 #ifdef KDB 5294 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5295 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5296 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5297 #endif 5298 5299 static void 5300 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5301 { 5302 5303 #ifdef KDB 5304 if (vfs_badlock_backtrace) 5305 kdb_backtrace(); 5306 #endif 5307 if (vfs_badlock_vnode) 5308 vn_printf(vp, "vnode "); 5309 if (vfs_badlock_print) 5310 printf("%s: %p %s\n", str, (void *)vp, msg); 5311 if (vfs_badlock_ddb) 5312 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5313 } 5314 5315 void 5316 assert_vi_locked(struct vnode *vp, const char *str) 5317 { 5318 5319 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5320 vfs_badlock("interlock is not locked but should be", str, vp); 5321 } 5322 5323 void 5324 assert_vi_unlocked(struct vnode *vp, const char *str) 5325 { 5326 5327 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5328 vfs_badlock("interlock is locked but should not be", str, vp); 5329 } 5330 5331 void 5332 assert_vop_locked(struct vnode *vp, const char *str) 5333 { 5334 int locked; 5335 5336 if (!IGNORE_LOCK(vp)) { 5337 locked = VOP_ISLOCKED(vp); 5338 if (locked == 0 || locked == LK_EXCLOTHER) 5339 vfs_badlock("is not locked but should be", str, vp); 5340 } 5341 } 5342 5343 void 5344 assert_vop_unlocked(struct vnode *vp, const char *str) 5345 { 5346 5347 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5348 vfs_badlock("is locked but should not be", str, vp); 5349 } 5350 5351 void 5352 assert_vop_elocked(struct vnode *vp, const char *str) 5353 { 5354 5355 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5356 vfs_badlock("is not exclusive locked but should be", str, vp); 5357 } 5358 #endif /* DEBUG_VFS_LOCKS */ 5359 5360 void 5361 vop_rename_fail(struct vop_rename_args *ap) 5362 { 5363 5364 if (ap->a_tvp != NULL) 5365 vput(ap->a_tvp); 5366 if (ap->a_tdvp == ap->a_tvp) 5367 vrele(ap->a_tdvp); 5368 else 5369 vput(ap->a_tdvp); 5370 vrele(ap->a_fdvp); 5371 vrele(ap->a_fvp); 5372 } 5373 5374 void 5375 vop_rename_pre(void *ap) 5376 { 5377 struct vop_rename_args *a = ap; 5378 5379 #ifdef DEBUG_VFS_LOCKS 5380 if (a->a_tvp) 5381 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5382 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5383 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5384 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5385 5386 /* Check the source (from). */ 5387 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5388 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5389 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5390 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5391 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5392 5393 /* Check the target. */ 5394 if (a->a_tvp) 5395 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5396 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5397 #endif 5398 if (a->a_tdvp != a->a_fdvp) 5399 vhold(a->a_fdvp); 5400 if (a->a_tvp != a->a_fvp) 5401 vhold(a->a_fvp); 5402 vhold(a->a_tdvp); 5403 if (a->a_tvp) 5404 vhold(a->a_tvp); 5405 } 5406 5407 #ifdef DEBUG_VFS_LOCKS 5408 void 5409 vop_strategy_pre(void *ap) 5410 { 5411 struct vop_strategy_args *a; 5412 struct buf *bp; 5413 5414 a = ap; 5415 bp = a->a_bp; 5416 5417 /* 5418 * Cluster ops lock their component buffers but not the IO container. 5419 */ 5420 if ((bp->b_flags & B_CLUSTER) != 0) 5421 return; 5422 5423 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5424 if (vfs_badlock_print) 5425 printf( 5426 "VOP_STRATEGY: bp is not locked but should be\n"); 5427 if (vfs_badlock_ddb) 5428 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5429 } 5430 } 5431 5432 void 5433 vop_lock_pre(void *ap) 5434 { 5435 struct vop_lock1_args *a = ap; 5436 5437 if ((a->a_flags & LK_INTERLOCK) == 0) 5438 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5439 else 5440 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5441 } 5442 5443 void 5444 vop_lock_post(void *ap, int rc) 5445 { 5446 struct vop_lock1_args *a = ap; 5447 5448 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5449 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5450 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5451 } 5452 5453 void 5454 vop_unlock_pre(void *ap) 5455 { 5456 struct vop_unlock_args *a = ap; 5457 5458 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5459 } 5460 5461 void 5462 vop_need_inactive_pre(void *ap) 5463 { 5464 struct vop_need_inactive_args *a = ap; 5465 5466 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5467 } 5468 5469 void 5470 vop_need_inactive_post(void *ap, int rc) 5471 { 5472 struct vop_need_inactive_args *a = ap; 5473 5474 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5475 } 5476 #endif 5477 5478 void 5479 vop_create_post(void *ap, int rc) 5480 { 5481 struct vop_create_args *a = ap; 5482 5483 if (!rc) 5484 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5485 } 5486 5487 void 5488 vop_deleteextattr_post(void *ap, int rc) 5489 { 5490 struct vop_deleteextattr_args *a = ap; 5491 5492 if (!rc) 5493 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5494 } 5495 5496 void 5497 vop_link_post(void *ap, int rc) 5498 { 5499 struct vop_link_args *a = ap; 5500 5501 if (!rc) { 5502 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 5503 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 5504 } 5505 } 5506 5507 void 5508 vop_mkdir_post(void *ap, int rc) 5509 { 5510 struct vop_mkdir_args *a = ap; 5511 5512 if (!rc) 5513 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5514 } 5515 5516 void 5517 vop_mknod_post(void *ap, int rc) 5518 { 5519 struct vop_mknod_args *a = ap; 5520 5521 if (!rc) 5522 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5523 } 5524 5525 void 5526 vop_reclaim_post(void *ap, int rc) 5527 { 5528 struct vop_reclaim_args *a = ap; 5529 5530 if (!rc) 5531 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 5532 } 5533 5534 void 5535 vop_remove_post(void *ap, int rc) 5536 { 5537 struct vop_remove_args *a = ap; 5538 5539 if (!rc) { 5540 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5541 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5542 } 5543 } 5544 5545 void 5546 vop_rename_post(void *ap, int rc) 5547 { 5548 struct vop_rename_args *a = ap; 5549 long hint; 5550 5551 if (!rc) { 5552 hint = NOTE_WRITE; 5553 if (a->a_fdvp == a->a_tdvp) { 5554 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5555 hint |= NOTE_LINK; 5556 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5557 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5558 } else { 5559 hint |= NOTE_EXTEND; 5560 if (a->a_fvp->v_type == VDIR) 5561 hint |= NOTE_LINK; 5562 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5563 5564 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5565 a->a_tvp->v_type == VDIR) 5566 hint &= ~NOTE_LINK; 5567 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5568 } 5569 5570 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5571 if (a->a_tvp) 5572 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5573 } 5574 if (a->a_tdvp != a->a_fdvp) 5575 vdrop(a->a_fdvp); 5576 if (a->a_tvp != a->a_fvp) 5577 vdrop(a->a_fvp); 5578 vdrop(a->a_tdvp); 5579 if (a->a_tvp) 5580 vdrop(a->a_tvp); 5581 } 5582 5583 void 5584 vop_rmdir_post(void *ap, int rc) 5585 { 5586 struct vop_rmdir_args *a = ap; 5587 5588 if (!rc) { 5589 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5590 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5591 } 5592 } 5593 5594 void 5595 vop_setattr_post(void *ap, int rc) 5596 { 5597 struct vop_setattr_args *a = ap; 5598 5599 if (!rc) 5600 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5601 } 5602 5603 void 5604 vop_setextattr_post(void *ap, int rc) 5605 { 5606 struct vop_setextattr_args *a = ap; 5607 5608 if (!rc) 5609 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5610 } 5611 5612 void 5613 vop_symlink_post(void *ap, int rc) 5614 { 5615 struct vop_symlink_args *a = ap; 5616 5617 if (!rc) 5618 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5619 } 5620 5621 void 5622 vop_open_post(void *ap, int rc) 5623 { 5624 struct vop_open_args *a = ap; 5625 5626 if (!rc) 5627 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5628 } 5629 5630 void 5631 vop_close_post(void *ap, int rc) 5632 { 5633 struct vop_close_args *a = ap; 5634 5635 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5636 !VN_IS_DOOMED(a->a_vp))) { 5637 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5638 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5639 } 5640 } 5641 5642 void 5643 vop_read_post(void *ap, int rc) 5644 { 5645 struct vop_read_args *a = ap; 5646 5647 if (!rc) 5648 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5649 } 5650 5651 void 5652 vop_readdir_post(void *ap, int rc) 5653 { 5654 struct vop_readdir_args *a = ap; 5655 5656 if (!rc) 5657 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5658 } 5659 5660 static struct knlist fs_knlist; 5661 5662 static void 5663 vfs_event_init(void *arg) 5664 { 5665 knlist_init_mtx(&fs_knlist, NULL); 5666 } 5667 /* XXX - correct order? */ 5668 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5669 5670 void 5671 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5672 { 5673 5674 KNOTE_UNLOCKED(&fs_knlist, event); 5675 } 5676 5677 static int filt_fsattach(struct knote *kn); 5678 static void filt_fsdetach(struct knote *kn); 5679 static int filt_fsevent(struct knote *kn, long hint); 5680 5681 struct filterops fs_filtops = { 5682 .f_isfd = 0, 5683 .f_attach = filt_fsattach, 5684 .f_detach = filt_fsdetach, 5685 .f_event = filt_fsevent 5686 }; 5687 5688 static int 5689 filt_fsattach(struct knote *kn) 5690 { 5691 5692 kn->kn_flags |= EV_CLEAR; 5693 knlist_add(&fs_knlist, kn, 0); 5694 return (0); 5695 } 5696 5697 static void 5698 filt_fsdetach(struct knote *kn) 5699 { 5700 5701 knlist_remove(&fs_knlist, kn, 0); 5702 } 5703 5704 static int 5705 filt_fsevent(struct knote *kn, long hint) 5706 { 5707 5708 kn->kn_fflags |= hint; 5709 return (kn->kn_fflags != 0); 5710 } 5711 5712 static int 5713 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5714 { 5715 struct vfsidctl vc; 5716 int error; 5717 struct mount *mp; 5718 5719 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5720 if (error) 5721 return (error); 5722 if (vc.vc_vers != VFS_CTL_VERS1) 5723 return (EINVAL); 5724 mp = vfs_getvfs(&vc.vc_fsid); 5725 if (mp == NULL) 5726 return (ENOENT); 5727 /* ensure that a specific sysctl goes to the right filesystem. */ 5728 if (strcmp(vc.vc_fstypename, "*") != 0 && 5729 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5730 vfs_rel(mp); 5731 return (EINVAL); 5732 } 5733 VCTLTOREQ(&vc, req); 5734 error = VFS_SYSCTL(mp, vc.vc_op, req); 5735 vfs_rel(mp); 5736 return (error); 5737 } 5738 5739 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 5740 NULL, 0, sysctl_vfs_ctl, "", 5741 "Sysctl by fsid"); 5742 5743 /* 5744 * Function to initialize a va_filerev field sensibly. 5745 * XXX: Wouldn't a random number make a lot more sense ?? 5746 */ 5747 u_quad_t 5748 init_va_filerev(void) 5749 { 5750 struct bintime bt; 5751 5752 getbinuptime(&bt); 5753 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5754 } 5755 5756 static int filt_vfsread(struct knote *kn, long hint); 5757 static int filt_vfswrite(struct knote *kn, long hint); 5758 static int filt_vfsvnode(struct knote *kn, long hint); 5759 static void filt_vfsdetach(struct knote *kn); 5760 static struct filterops vfsread_filtops = { 5761 .f_isfd = 1, 5762 .f_detach = filt_vfsdetach, 5763 .f_event = filt_vfsread 5764 }; 5765 static struct filterops vfswrite_filtops = { 5766 .f_isfd = 1, 5767 .f_detach = filt_vfsdetach, 5768 .f_event = filt_vfswrite 5769 }; 5770 static struct filterops vfsvnode_filtops = { 5771 .f_isfd = 1, 5772 .f_detach = filt_vfsdetach, 5773 .f_event = filt_vfsvnode 5774 }; 5775 5776 static void 5777 vfs_knllock(void *arg) 5778 { 5779 struct vnode *vp = arg; 5780 5781 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5782 } 5783 5784 static void 5785 vfs_knlunlock(void *arg) 5786 { 5787 struct vnode *vp = arg; 5788 5789 VOP_UNLOCK(vp); 5790 } 5791 5792 static void 5793 vfs_knl_assert_locked(void *arg) 5794 { 5795 #ifdef DEBUG_VFS_LOCKS 5796 struct vnode *vp = arg; 5797 5798 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5799 #endif 5800 } 5801 5802 static void 5803 vfs_knl_assert_unlocked(void *arg) 5804 { 5805 #ifdef DEBUG_VFS_LOCKS 5806 struct vnode *vp = arg; 5807 5808 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5809 #endif 5810 } 5811 5812 int 5813 vfs_kqfilter(struct vop_kqfilter_args *ap) 5814 { 5815 struct vnode *vp = ap->a_vp; 5816 struct knote *kn = ap->a_kn; 5817 struct knlist *knl; 5818 5819 switch (kn->kn_filter) { 5820 case EVFILT_READ: 5821 kn->kn_fop = &vfsread_filtops; 5822 break; 5823 case EVFILT_WRITE: 5824 kn->kn_fop = &vfswrite_filtops; 5825 break; 5826 case EVFILT_VNODE: 5827 kn->kn_fop = &vfsvnode_filtops; 5828 break; 5829 default: 5830 return (EINVAL); 5831 } 5832 5833 kn->kn_hook = (caddr_t)vp; 5834 5835 v_addpollinfo(vp); 5836 if (vp->v_pollinfo == NULL) 5837 return (ENOMEM); 5838 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5839 vhold(vp); 5840 knlist_add(knl, kn, 0); 5841 5842 return (0); 5843 } 5844 5845 /* 5846 * Detach knote from vnode 5847 */ 5848 static void 5849 filt_vfsdetach(struct knote *kn) 5850 { 5851 struct vnode *vp = (struct vnode *)kn->kn_hook; 5852 5853 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5854 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5855 vdrop(vp); 5856 } 5857 5858 /*ARGSUSED*/ 5859 static int 5860 filt_vfsread(struct knote *kn, long hint) 5861 { 5862 struct vnode *vp = (struct vnode *)kn->kn_hook; 5863 struct vattr va; 5864 int res; 5865 5866 /* 5867 * filesystem is gone, so set the EOF flag and schedule 5868 * the knote for deletion. 5869 */ 5870 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5871 VI_LOCK(vp); 5872 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5873 VI_UNLOCK(vp); 5874 return (1); 5875 } 5876 5877 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5878 return (0); 5879 5880 VI_LOCK(vp); 5881 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5882 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5883 VI_UNLOCK(vp); 5884 return (res); 5885 } 5886 5887 /*ARGSUSED*/ 5888 static int 5889 filt_vfswrite(struct knote *kn, long hint) 5890 { 5891 struct vnode *vp = (struct vnode *)kn->kn_hook; 5892 5893 VI_LOCK(vp); 5894 5895 /* 5896 * filesystem is gone, so set the EOF flag and schedule 5897 * the knote for deletion. 5898 */ 5899 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5900 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5901 5902 kn->kn_data = 0; 5903 VI_UNLOCK(vp); 5904 return (1); 5905 } 5906 5907 static int 5908 filt_vfsvnode(struct knote *kn, long hint) 5909 { 5910 struct vnode *vp = (struct vnode *)kn->kn_hook; 5911 int res; 5912 5913 VI_LOCK(vp); 5914 if (kn->kn_sfflags & hint) 5915 kn->kn_fflags |= hint; 5916 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5917 kn->kn_flags |= EV_EOF; 5918 VI_UNLOCK(vp); 5919 return (1); 5920 } 5921 res = (kn->kn_fflags != 0); 5922 VI_UNLOCK(vp); 5923 return (res); 5924 } 5925 5926 /* 5927 * Returns whether the directory is empty or not. 5928 * If it is empty, the return value is 0; otherwise 5929 * the return value is an error value (which may 5930 * be ENOTEMPTY). 5931 */ 5932 int 5933 vfs_emptydir(struct vnode *vp) 5934 { 5935 struct uio uio; 5936 struct iovec iov; 5937 struct dirent *dirent, *dp, *endp; 5938 int error, eof; 5939 5940 error = 0; 5941 eof = 0; 5942 5943 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 5944 5945 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 5946 iov.iov_base = dirent; 5947 iov.iov_len = sizeof(struct dirent); 5948 5949 uio.uio_iov = &iov; 5950 uio.uio_iovcnt = 1; 5951 uio.uio_offset = 0; 5952 uio.uio_resid = sizeof(struct dirent); 5953 uio.uio_segflg = UIO_SYSSPACE; 5954 uio.uio_rw = UIO_READ; 5955 uio.uio_td = curthread; 5956 5957 while (eof == 0 && error == 0) { 5958 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 5959 NULL, NULL); 5960 if (error != 0) 5961 break; 5962 endp = (void *)((uint8_t *)dirent + 5963 sizeof(struct dirent) - uio.uio_resid); 5964 for (dp = dirent; dp < endp; 5965 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 5966 if (dp->d_type == DT_WHT) 5967 continue; 5968 if (dp->d_namlen == 0) 5969 continue; 5970 if (dp->d_type != DT_DIR && 5971 dp->d_type != DT_UNKNOWN) { 5972 error = ENOTEMPTY; 5973 break; 5974 } 5975 if (dp->d_namlen > 2) { 5976 error = ENOTEMPTY; 5977 break; 5978 } 5979 if (dp->d_namlen == 1 && 5980 dp->d_name[0] != '.') { 5981 error = ENOTEMPTY; 5982 break; 5983 } 5984 if (dp->d_namlen == 2 && 5985 dp->d_name[1] != '.') { 5986 error = ENOTEMPTY; 5987 break; 5988 } 5989 uio.uio_resid = sizeof(struct dirent); 5990 } 5991 } 5992 free(dirent, M_TEMP); 5993 return (error); 5994 } 5995 5996 int 5997 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5998 { 5999 int error; 6000 6001 if (dp->d_reclen > ap->a_uio->uio_resid) 6002 return (ENAMETOOLONG); 6003 error = uiomove(dp, dp->d_reclen, ap->a_uio); 6004 if (error) { 6005 if (ap->a_ncookies != NULL) { 6006 if (ap->a_cookies != NULL) 6007 free(ap->a_cookies, M_TEMP); 6008 ap->a_cookies = NULL; 6009 *ap->a_ncookies = 0; 6010 } 6011 return (error); 6012 } 6013 if (ap->a_ncookies == NULL) 6014 return (0); 6015 6016 KASSERT(ap->a_cookies, 6017 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 6018 6019 *ap->a_cookies = realloc(*ap->a_cookies, 6020 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 6021 (*ap->a_cookies)[*ap->a_ncookies] = off; 6022 *ap->a_ncookies += 1; 6023 return (0); 6024 } 6025 6026 /* 6027 * The purpose of this routine is to remove granularity from accmode_t, 6028 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 6029 * VADMIN and VAPPEND. 6030 * 6031 * If it returns 0, the caller is supposed to continue with the usual 6032 * access checks using 'accmode' as modified by this routine. If it 6033 * returns nonzero value, the caller is supposed to return that value 6034 * as errno. 6035 * 6036 * Note that after this routine runs, accmode may be zero. 6037 */ 6038 int 6039 vfs_unixify_accmode(accmode_t *accmode) 6040 { 6041 /* 6042 * There is no way to specify explicit "deny" rule using 6043 * file mode or POSIX.1e ACLs. 6044 */ 6045 if (*accmode & VEXPLICIT_DENY) { 6046 *accmode = 0; 6047 return (0); 6048 } 6049 6050 /* 6051 * None of these can be translated into usual access bits. 6052 * Also, the common case for NFSv4 ACLs is to not contain 6053 * either of these bits. Caller should check for VWRITE 6054 * on the containing directory instead. 6055 */ 6056 if (*accmode & (VDELETE_CHILD | VDELETE)) 6057 return (EPERM); 6058 6059 if (*accmode & VADMIN_PERMS) { 6060 *accmode &= ~VADMIN_PERMS; 6061 *accmode |= VADMIN; 6062 } 6063 6064 /* 6065 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6066 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6067 */ 6068 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6069 6070 return (0); 6071 } 6072 6073 /* 6074 * Clear out a doomed vnode (if any) and replace it with a new one as long 6075 * as the fs is not being unmounted. Return the root vnode to the caller. 6076 */ 6077 static int __noinline 6078 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6079 { 6080 struct vnode *vp; 6081 int error; 6082 6083 restart: 6084 if (mp->mnt_rootvnode != NULL) { 6085 MNT_ILOCK(mp); 6086 vp = mp->mnt_rootvnode; 6087 if (vp != NULL) { 6088 if (!VN_IS_DOOMED(vp)) { 6089 vrefact(vp); 6090 MNT_IUNLOCK(mp); 6091 error = vn_lock(vp, flags); 6092 if (error == 0) { 6093 *vpp = vp; 6094 return (0); 6095 } 6096 vrele(vp); 6097 goto restart; 6098 } 6099 /* 6100 * Clear the old one. 6101 */ 6102 mp->mnt_rootvnode = NULL; 6103 } 6104 MNT_IUNLOCK(mp); 6105 if (vp != NULL) { 6106 vfs_op_barrier_wait(mp); 6107 vrele(vp); 6108 } 6109 } 6110 error = VFS_CACHEDROOT(mp, flags, vpp); 6111 if (error != 0) 6112 return (error); 6113 if (mp->mnt_vfs_ops == 0) { 6114 MNT_ILOCK(mp); 6115 if (mp->mnt_vfs_ops != 0) { 6116 MNT_IUNLOCK(mp); 6117 return (0); 6118 } 6119 if (mp->mnt_rootvnode == NULL) { 6120 vrefact(*vpp); 6121 mp->mnt_rootvnode = *vpp; 6122 } else { 6123 if (mp->mnt_rootvnode != *vpp) { 6124 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6125 panic("%s: mismatch between vnode returned " 6126 " by VFS_CACHEDROOT and the one cached " 6127 " (%p != %p)", 6128 __func__, *vpp, mp->mnt_rootvnode); 6129 } 6130 } 6131 } 6132 MNT_IUNLOCK(mp); 6133 } 6134 return (0); 6135 } 6136 6137 int 6138 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6139 { 6140 struct vnode *vp; 6141 int error; 6142 6143 if (!vfs_op_thread_enter(mp)) 6144 return (vfs_cache_root_fallback(mp, flags, vpp)); 6145 vp = atomic_load_ptr(&mp->mnt_rootvnode); 6146 if (vp == NULL || VN_IS_DOOMED(vp)) { 6147 vfs_op_thread_exit(mp); 6148 return (vfs_cache_root_fallback(mp, flags, vpp)); 6149 } 6150 vrefact(vp); 6151 vfs_op_thread_exit(mp); 6152 error = vn_lock(vp, flags); 6153 if (error != 0) { 6154 vrele(vp); 6155 return (vfs_cache_root_fallback(mp, flags, vpp)); 6156 } 6157 *vpp = vp; 6158 return (0); 6159 } 6160 6161 struct vnode * 6162 vfs_cache_root_clear(struct mount *mp) 6163 { 6164 struct vnode *vp; 6165 6166 /* 6167 * ops > 0 guarantees there is nobody who can see this vnode 6168 */ 6169 MPASS(mp->mnt_vfs_ops > 0); 6170 vp = mp->mnt_rootvnode; 6171 mp->mnt_rootvnode = NULL; 6172 return (vp); 6173 } 6174 6175 void 6176 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6177 { 6178 6179 MPASS(mp->mnt_vfs_ops > 0); 6180 vrefact(vp); 6181 mp->mnt_rootvnode = vp; 6182 } 6183 6184 /* 6185 * These are helper functions for filesystems to traverse all 6186 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6187 * 6188 * This interface replaces MNT_VNODE_FOREACH. 6189 */ 6190 6191 struct vnode * 6192 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6193 { 6194 struct vnode *vp; 6195 6196 if (should_yield()) 6197 kern_yield(PRI_USER); 6198 MNT_ILOCK(mp); 6199 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6200 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6201 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6202 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6203 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6204 continue; 6205 VI_LOCK(vp); 6206 if (VN_IS_DOOMED(vp)) { 6207 VI_UNLOCK(vp); 6208 continue; 6209 } 6210 break; 6211 } 6212 if (vp == NULL) { 6213 __mnt_vnode_markerfree_all(mvp, mp); 6214 /* MNT_IUNLOCK(mp); -- done in above function */ 6215 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6216 return (NULL); 6217 } 6218 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6219 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6220 MNT_IUNLOCK(mp); 6221 return (vp); 6222 } 6223 6224 struct vnode * 6225 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6226 { 6227 struct vnode *vp; 6228 6229 *mvp = vn_alloc_marker(mp); 6230 MNT_ILOCK(mp); 6231 MNT_REF(mp); 6232 6233 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6234 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6235 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6236 continue; 6237 VI_LOCK(vp); 6238 if (VN_IS_DOOMED(vp)) { 6239 VI_UNLOCK(vp); 6240 continue; 6241 } 6242 break; 6243 } 6244 if (vp == NULL) { 6245 MNT_REL(mp); 6246 MNT_IUNLOCK(mp); 6247 vn_free_marker(*mvp); 6248 *mvp = NULL; 6249 return (NULL); 6250 } 6251 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6252 MNT_IUNLOCK(mp); 6253 return (vp); 6254 } 6255 6256 void 6257 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6258 { 6259 6260 if (*mvp == NULL) { 6261 MNT_IUNLOCK(mp); 6262 return; 6263 } 6264 6265 mtx_assert(MNT_MTX(mp), MA_OWNED); 6266 6267 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6268 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6269 MNT_REL(mp); 6270 MNT_IUNLOCK(mp); 6271 vn_free_marker(*mvp); 6272 *mvp = NULL; 6273 } 6274 6275 /* 6276 * These are helper functions for filesystems to traverse their 6277 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6278 */ 6279 static void 6280 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6281 { 6282 6283 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6284 6285 MNT_ILOCK(mp); 6286 MNT_REL(mp); 6287 MNT_IUNLOCK(mp); 6288 vn_free_marker(*mvp); 6289 *mvp = NULL; 6290 } 6291 6292 /* 6293 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6294 * conventional lock order during mnt_vnode_next_lazy iteration. 6295 * 6296 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6297 * The list lock is dropped and reacquired. On success, both locks are held. 6298 * On failure, the mount vnode list lock is held but the vnode interlock is 6299 * not, and the procedure may have yielded. 6300 */ 6301 static bool 6302 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6303 struct vnode *vp) 6304 { 6305 6306 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6307 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6308 ("%s: bad marker", __func__)); 6309 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6310 ("%s: inappropriate vnode", __func__)); 6311 ASSERT_VI_UNLOCKED(vp, __func__); 6312 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6313 6314 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6315 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6316 6317 /* 6318 * Note we may be racing against vdrop which transitioned the hold 6319 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine, 6320 * if we are the only user after we get the interlock we will just 6321 * vdrop. 6322 */ 6323 vhold(vp); 6324 mtx_unlock(&mp->mnt_listmtx); 6325 VI_LOCK(vp); 6326 if (VN_IS_DOOMED(vp)) { 6327 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6328 goto out_lost; 6329 } 6330 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6331 /* 6332 * There is nothing to do if we are the last user. 6333 */ 6334 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6335 goto out_lost; 6336 mtx_lock(&mp->mnt_listmtx); 6337 return (true); 6338 out_lost: 6339 vdropl(vp); 6340 maybe_yield(); 6341 mtx_lock(&mp->mnt_listmtx); 6342 return (false); 6343 } 6344 6345 static struct vnode * 6346 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6347 void *cbarg) 6348 { 6349 struct vnode *vp; 6350 6351 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6352 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6353 restart: 6354 vp = TAILQ_NEXT(*mvp, v_lazylist); 6355 while (vp != NULL) { 6356 if (vp->v_type == VMARKER) { 6357 vp = TAILQ_NEXT(vp, v_lazylist); 6358 continue; 6359 } 6360 /* 6361 * See if we want to process the vnode. Note we may encounter a 6362 * long string of vnodes we don't care about and hog the list 6363 * as a result. Check for it and requeue the marker. 6364 */ 6365 VNPASS(!VN_IS_DOOMED(vp), vp); 6366 if (!cb(vp, cbarg)) { 6367 if (!should_yield()) { 6368 vp = TAILQ_NEXT(vp, v_lazylist); 6369 continue; 6370 } 6371 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 6372 v_lazylist); 6373 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 6374 v_lazylist); 6375 mtx_unlock(&mp->mnt_listmtx); 6376 kern_yield(PRI_USER); 6377 mtx_lock(&mp->mnt_listmtx); 6378 goto restart; 6379 } 6380 /* 6381 * Try-lock because this is the wrong lock order. 6382 */ 6383 if (!VI_TRYLOCK(vp) && 6384 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 6385 goto restart; 6386 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 6387 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 6388 ("alien vnode on the lazy list %p %p", vp, mp)); 6389 VNPASS(vp->v_mount == mp, vp); 6390 VNPASS(!VN_IS_DOOMED(vp), vp); 6391 break; 6392 } 6393 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6394 6395 /* Check if we are done */ 6396 if (vp == NULL) { 6397 mtx_unlock(&mp->mnt_listmtx); 6398 mnt_vnode_markerfree_lazy(mvp, mp); 6399 return (NULL); 6400 } 6401 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 6402 mtx_unlock(&mp->mnt_listmtx); 6403 ASSERT_VI_LOCKED(vp, "lazy iter"); 6404 return (vp); 6405 } 6406 6407 struct vnode * 6408 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6409 void *cbarg) 6410 { 6411 6412 if (should_yield()) 6413 kern_yield(PRI_USER); 6414 mtx_lock(&mp->mnt_listmtx); 6415 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6416 } 6417 6418 struct vnode * 6419 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6420 void *cbarg) 6421 { 6422 struct vnode *vp; 6423 6424 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 6425 return (NULL); 6426 6427 *mvp = vn_alloc_marker(mp); 6428 MNT_ILOCK(mp); 6429 MNT_REF(mp); 6430 MNT_IUNLOCK(mp); 6431 6432 mtx_lock(&mp->mnt_listmtx); 6433 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 6434 if (vp == NULL) { 6435 mtx_unlock(&mp->mnt_listmtx); 6436 mnt_vnode_markerfree_lazy(mvp, mp); 6437 return (NULL); 6438 } 6439 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 6440 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6441 } 6442 6443 void 6444 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6445 { 6446 6447 if (*mvp == NULL) 6448 return; 6449 6450 mtx_lock(&mp->mnt_listmtx); 6451 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6452 mtx_unlock(&mp->mnt_listmtx); 6453 mnt_vnode_markerfree_lazy(mvp, mp); 6454 } 6455 6456 int 6457 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 6458 { 6459 6460 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 6461 cnp->cn_flags &= ~NOEXECCHECK; 6462 return (0); 6463 } 6464 6465 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread)); 6466 } 6467