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