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/smr.h> 80 #include <sys/smp.h> 81 #include <sys/stat.h> 82 #include <sys/sysctl.h> 83 #include <sys/syslog.h> 84 #include <sys/vmmeter.h> 85 #include <sys/vnode.h> 86 #include <sys/watchdog.h> 87 88 #include <machine/stdarg.h> 89 90 #include <security/mac/mac_framework.h> 91 92 #include <vm/vm.h> 93 #include <vm/vm_object.h> 94 #include <vm/vm_extern.h> 95 #include <vm/pmap.h> 96 #include <vm/vm_map.h> 97 #include <vm/vm_page.h> 98 #include <vm/vm_kern.h> 99 #include <vm/uma.h> 100 101 #ifdef DDB 102 #include <ddb/ddb.h> 103 #endif 104 105 static void delmntque(struct vnode *vp); 106 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 107 int slpflag, int slptimeo); 108 static void syncer_shutdown(void *arg, int howto); 109 static int vtryrecycle(struct vnode *vp); 110 static void v_init_counters(struct vnode *); 111 static void v_incr_devcount(struct vnode *); 112 static void v_decr_devcount(struct vnode *); 113 static void vgonel(struct vnode *); 114 static void vfs_knllock(void *arg); 115 static void vfs_knlunlock(void *arg); 116 static void vfs_knl_assert_locked(void *arg); 117 static void vfs_knl_assert_unlocked(void *arg); 118 static void destroy_vpollinfo(struct vpollinfo *vi); 119 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 120 daddr_t startlbn, daddr_t endlbn); 121 static void vnlru_recalc(void); 122 123 /* 124 * These fences are intended for cases where some synchronization is 125 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 126 * and v_usecount) updates. Access to v_iflags is generally synchronized 127 * by the interlock, but we have some internal assertions that check vnode 128 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 129 * for now. 130 */ 131 #ifdef INVARIANTS 132 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 133 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 134 #else 135 #define VNODE_REFCOUNT_FENCE_ACQ() 136 #define VNODE_REFCOUNT_FENCE_REL() 137 #endif 138 139 /* 140 * Number of vnodes in existence. Increased whenever getnewvnode() 141 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode. 142 */ 143 static u_long __exclusive_cache_line numvnodes; 144 145 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 146 "Number of vnodes in existence"); 147 148 static counter_u64_t vnodes_created; 149 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 150 "Number of vnodes created by getnewvnode"); 151 152 /* 153 * Conversion tables for conversion from vnode types to inode formats 154 * and back. 155 */ 156 enum vtype iftovt_tab[16] = { 157 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 158 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 159 }; 160 int vttoif_tab[10] = { 161 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 162 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 163 }; 164 165 /* 166 * List of allocates vnodes in the system. 167 */ 168 static TAILQ_HEAD(freelst, vnode) vnode_list; 169 static struct vnode *vnode_list_free_marker; 170 static struct vnode *vnode_list_reclaim_marker; 171 172 /* 173 * "Free" vnode target. Free vnodes are rarely completely free, but are 174 * just ones that are cheap to recycle. Usually they are for files which 175 * have been stat'd but not read; these usually have inode and namecache 176 * data attached to them. This target is the preferred minimum size of a 177 * sub-cache consisting mostly of such files. The system balances the size 178 * of this sub-cache with its complement to try to prevent either from 179 * thrashing while the other is relatively inactive. The targets express 180 * a preference for the best balance. 181 * 182 * "Above" this target there are 2 further targets (watermarks) related 183 * to recyling of free vnodes. In the best-operating case, the cache is 184 * exactly full, the free list has size between vlowat and vhiwat above the 185 * free target, and recycling from it and normal use maintains this state. 186 * Sometimes the free list is below vlowat or even empty, but this state 187 * is even better for immediate use provided the cache is not full. 188 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 189 * ones) to reach one of these states. The watermarks are currently hard- 190 * coded as 4% and 9% of the available space higher. These and the default 191 * of 25% for wantfreevnodes are too large if the memory size is large. 192 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 193 * whenever vnlru_proc() becomes active. 194 */ 195 static long wantfreevnodes; 196 static long __exclusive_cache_line freevnodes; 197 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 198 &freevnodes, 0, "Number of \"free\" vnodes"); 199 static long freevnodes_old; 200 201 static counter_u64_t recycles_count; 202 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 203 "Number of vnodes recycled to meet vnode cache targets"); 204 205 static counter_u64_t recycles_free_count; 206 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD, &recycles_free_count, 207 "Number of free vnodes recycled to meet vnode cache targets"); 208 209 /* 210 * Various variables used for debugging the new implementation of 211 * reassignbuf(). 212 * XXX these are probably of (very) limited utility now. 213 */ 214 static int reassignbufcalls; 215 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW | CTLFLAG_STATS, 216 &reassignbufcalls, 0, "Number of calls to reassignbuf"); 217 218 static counter_u64_t deferred_inact; 219 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD, &deferred_inact, 220 "Number of times inactive processing was deferred"); 221 222 /* To keep more than one thread at a time from running vfs_getnewfsid */ 223 static struct mtx mntid_mtx; 224 225 /* 226 * Lock for any access to the following: 227 * vnode_list 228 * numvnodes 229 * freevnodes 230 */ 231 static struct mtx __exclusive_cache_line vnode_list_mtx; 232 233 /* Publicly exported FS */ 234 struct nfs_public nfs_pub; 235 236 static uma_zone_t buf_trie_zone; 237 static smr_t buf_trie_smr; 238 239 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 240 static uma_zone_t vnode_zone; 241 static uma_zone_t vnodepoll_zone; 242 243 __read_frequently smr_t vfs_smr; 244 245 /* 246 * The workitem queue. 247 * 248 * It is useful to delay writes of file data and filesystem metadata 249 * for tens of seconds so that quickly created and deleted files need 250 * not waste disk bandwidth being created and removed. To realize this, 251 * we append vnodes to a "workitem" queue. When running with a soft 252 * updates implementation, most pending metadata dependencies should 253 * not wait for more than a few seconds. Thus, mounted on block devices 254 * are delayed only about a half the time that file data is delayed. 255 * Similarly, directory updates are more critical, so are only delayed 256 * about a third the time that file data is delayed. Thus, there are 257 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 258 * one each second (driven off the filesystem syncer process). The 259 * syncer_delayno variable indicates the next queue that is to be processed. 260 * Items that need to be processed soon are placed in this queue: 261 * 262 * syncer_workitem_pending[syncer_delayno] 263 * 264 * A delay of fifteen seconds is done by placing the request fifteen 265 * entries later in the queue: 266 * 267 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 268 * 269 */ 270 static int syncer_delayno; 271 static long syncer_mask; 272 LIST_HEAD(synclist, bufobj); 273 static struct synclist *syncer_workitem_pending; 274 /* 275 * The sync_mtx protects: 276 * bo->bo_synclist 277 * sync_vnode_count 278 * syncer_delayno 279 * syncer_state 280 * syncer_workitem_pending 281 * syncer_worklist_len 282 * rushjob 283 */ 284 static struct mtx sync_mtx; 285 static struct cv sync_wakeup; 286 287 #define SYNCER_MAXDELAY 32 288 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 289 static int syncdelay = 30; /* max time to delay syncing data */ 290 static int filedelay = 30; /* time to delay syncing files */ 291 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 292 "Time to delay syncing files (in seconds)"); 293 static int dirdelay = 29; /* time to delay syncing directories */ 294 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 295 "Time to delay syncing directories (in seconds)"); 296 static int metadelay = 28; /* time to delay syncing metadata */ 297 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 298 "Time to delay syncing metadata (in seconds)"); 299 static int rushjob; /* number of slots to run ASAP */ 300 static int stat_rush_requests; /* number of times I/O speeded up */ 301 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 302 "Number of times I/O speeded up (rush requests)"); 303 304 #define VDBATCH_SIZE 8 305 struct vdbatch { 306 u_int index; 307 long freevnodes; 308 struct mtx lock; 309 struct vnode *tab[VDBATCH_SIZE]; 310 }; 311 DPCPU_DEFINE_STATIC(struct vdbatch, vd); 312 313 static void vdbatch_dequeue(struct vnode *vp); 314 315 /* 316 * When shutting down the syncer, run it at four times normal speed. 317 */ 318 #define SYNCER_SHUTDOWN_SPEEDUP 4 319 static int sync_vnode_count; 320 static int syncer_worklist_len; 321 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 322 syncer_state; 323 324 /* Target for maximum number of vnodes. */ 325 u_long desiredvnodes; 326 static u_long gapvnodes; /* gap between wanted and desired */ 327 static u_long vhiwat; /* enough extras after expansion */ 328 static u_long vlowat; /* minimal extras before expansion */ 329 static u_long vstir; /* nonzero to stir non-free vnodes */ 330 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 331 332 static u_long vnlru_read_freevnodes(void); 333 334 /* 335 * Note that no attempt is made to sanitize these parameters. 336 */ 337 static int 338 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS) 339 { 340 u_long val; 341 int error; 342 343 val = desiredvnodes; 344 error = sysctl_handle_long(oidp, &val, 0, req); 345 if (error != 0 || req->newptr == NULL) 346 return (error); 347 348 if (val == desiredvnodes) 349 return (0); 350 mtx_lock(&vnode_list_mtx); 351 desiredvnodes = val; 352 wantfreevnodes = desiredvnodes / 4; 353 vnlru_recalc(); 354 mtx_unlock(&vnode_list_mtx); 355 /* 356 * XXX There is no protection against multiple threads changing 357 * desiredvnodes at the same time. Locking above only helps vnlru and 358 * getnewvnode. 359 */ 360 vfs_hash_changesize(desiredvnodes); 361 cache_changesize(desiredvnodes); 362 return (0); 363 } 364 365 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 366 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes, 367 "LU", "Target for maximum number of vnodes"); 368 369 static int 370 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS) 371 { 372 u_long val; 373 int error; 374 375 val = wantfreevnodes; 376 error = sysctl_handle_long(oidp, &val, 0, req); 377 if (error != 0 || req->newptr == NULL) 378 return (error); 379 380 if (val == wantfreevnodes) 381 return (0); 382 mtx_lock(&vnode_list_mtx); 383 wantfreevnodes = val; 384 vnlru_recalc(); 385 mtx_unlock(&vnode_list_mtx); 386 return (0); 387 } 388 389 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes, 390 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes, 391 "LU", "Target for minimum number of \"free\" vnodes"); 392 393 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 394 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 395 static int vnlru_nowhere; 396 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 397 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 398 399 static int 400 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 401 { 402 struct vnode *vp; 403 struct nameidata nd; 404 char *buf; 405 unsigned long ndflags; 406 int error; 407 408 if (req->newptr == NULL) 409 return (EINVAL); 410 if (req->newlen >= PATH_MAX) 411 return (E2BIG); 412 413 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK); 414 error = SYSCTL_IN(req, buf, req->newlen); 415 if (error != 0) 416 goto out; 417 418 buf[req->newlen] = '\0'; 419 420 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME; 421 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); 422 if ((error = namei(&nd)) != 0) 423 goto out; 424 vp = nd.ni_vp; 425 426 if (VN_IS_DOOMED(vp)) { 427 /* 428 * This vnode is being recycled. Return != 0 to let the caller 429 * know that the sysctl had no effect. Return EAGAIN because a 430 * subsequent call will likely succeed (since namei will create 431 * a new vnode if necessary) 432 */ 433 error = EAGAIN; 434 goto putvnode; 435 } 436 437 counter_u64_add(recycles_count, 1); 438 vgone(vp); 439 putvnode: 440 NDFREE(&nd, 0); 441 out: 442 free(buf, M_TEMP); 443 return (error); 444 } 445 446 static int 447 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 448 { 449 struct thread *td = curthread; 450 struct vnode *vp; 451 struct file *fp; 452 int error; 453 int fd; 454 455 if (req->newptr == NULL) 456 return (EBADF); 457 458 error = sysctl_handle_int(oidp, &fd, 0, req); 459 if (error != 0) 460 return (error); 461 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 462 if (error != 0) 463 return (error); 464 vp = fp->f_vnode; 465 466 error = vn_lock(vp, LK_EXCLUSIVE); 467 if (error != 0) 468 goto drop; 469 470 counter_u64_add(recycles_count, 1); 471 vgone(vp); 472 VOP_UNLOCK(vp); 473 drop: 474 fdrop(fp, td); 475 return (error); 476 } 477 478 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 479 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 480 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 481 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 482 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 483 sysctl_ftry_reclaim_vnode, "I", 484 "Try to reclaim a vnode by its file descriptor"); 485 486 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 487 static int vnsz2log; 488 489 /* 490 * Support for the bufobj clean & dirty pctrie. 491 */ 492 static void * 493 buf_trie_alloc(struct pctrie *ptree) 494 { 495 return (uma_zalloc_smr(buf_trie_zone, M_NOWAIT)); 496 } 497 498 static void 499 buf_trie_free(struct pctrie *ptree, void *node) 500 { 501 uma_zfree_smr(buf_trie_zone, node); 502 } 503 PCTRIE_DEFINE_SMR(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free, 504 buf_trie_smr); 505 506 /* 507 * Initialize the vnode management data structures. 508 * 509 * Reevaluate the following cap on the number of vnodes after the physical 510 * memory size exceeds 512GB. In the limit, as the physical memory size 511 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 512 */ 513 #ifndef MAXVNODES_MAX 514 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */ 515 #endif 516 517 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 518 519 static struct vnode * 520 vn_alloc_marker(struct mount *mp) 521 { 522 struct vnode *vp; 523 524 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 525 vp->v_type = VMARKER; 526 vp->v_mount = mp; 527 528 return (vp); 529 } 530 531 static void 532 vn_free_marker(struct vnode *vp) 533 { 534 535 MPASS(vp->v_type == VMARKER); 536 free(vp, M_VNODE_MARKER); 537 } 538 539 /* 540 * Initialize a vnode as it first enters the zone. 541 */ 542 static int 543 vnode_init(void *mem, int size, int flags) 544 { 545 struct vnode *vp; 546 547 vp = mem; 548 bzero(vp, size); 549 /* 550 * Setup locks. 551 */ 552 vp->v_vnlock = &vp->v_lock; 553 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 554 /* 555 * By default, don't allow shared locks unless filesystems opt-in. 556 */ 557 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 558 LK_NOSHARE | LK_IS_VNODE); 559 /* 560 * Initialize bufobj. 561 */ 562 bufobj_init(&vp->v_bufobj, vp); 563 /* 564 * Initialize namecache. 565 */ 566 LIST_INIT(&vp->v_cache_src); 567 TAILQ_INIT(&vp->v_cache_dst); 568 /* 569 * Initialize rangelocks. 570 */ 571 rangelock_init(&vp->v_rl); 572 573 vp->v_dbatchcpu = NOCPU; 574 575 mtx_lock(&vnode_list_mtx); 576 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist); 577 mtx_unlock(&vnode_list_mtx); 578 return (0); 579 } 580 581 /* 582 * Free a vnode when it is cleared from the zone. 583 */ 584 static void 585 vnode_fini(void *mem, int size) 586 { 587 struct vnode *vp; 588 struct bufobj *bo; 589 590 vp = mem; 591 vdbatch_dequeue(vp); 592 mtx_lock(&vnode_list_mtx); 593 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 594 mtx_unlock(&vnode_list_mtx); 595 rangelock_destroy(&vp->v_rl); 596 lockdestroy(vp->v_vnlock); 597 mtx_destroy(&vp->v_interlock); 598 bo = &vp->v_bufobj; 599 rw_destroy(BO_LOCKPTR(bo)); 600 } 601 602 /* 603 * Provide the size of NFS nclnode and NFS fh for calculation of the 604 * vnode memory consumption. The size is specified directly to 605 * eliminate dependency on NFS-private header. 606 * 607 * Other filesystems may use bigger or smaller (like UFS and ZFS) 608 * private inode data, but the NFS-based estimation is ample enough. 609 * Still, we care about differences in the size between 64- and 32-bit 610 * platforms. 611 * 612 * Namecache structure size is heuristically 613 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 614 */ 615 #ifdef _LP64 616 #define NFS_NCLNODE_SZ (528 + 64) 617 #define NC_SZ 148 618 #else 619 #define NFS_NCLNODE_SZ (360 + 32) 620 #define NC_SZ 92 621 #endif 622 623 static void 624 vntblinit(void *dummy __unused) 625 { 626 struct vdbatch *vd; 627 int cpu, physvnodes, virtvnodes; 628 u_int i; 629 630 /* 631 * Desiredvnodes is a function of the physical memory size and the 632 * kernel's heap size. Generally speaking, it scales with the 633 * physical memory size. The ratio of desiredvnodes to the physical 634 * memory size is 1:16 until desiredvnodes exceeds 98,304. 635 * Thereafter, the 636 * marginal ratio of desiredvnodes to the physical memory size is 637 * 1:64. However, desiredvnodes is limited by the kernel's heap 638 * size. The memory required by desiredvnodes vnodes and vm objects 639 * must not exceed 1/10th of the kernel's heap size. 640 */ 641 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 642 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 643 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 644 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 645 desiredvnodes = min(physvnodes, virtvnodes); 646 if (desiredvnodes > MAXVNODES_MAX) { 647 if (bootverbose) 648 printf("Reducing kern.maxvnodes %lu -> %lu\n", 649 desiredvnodes, MAXVNODES_MAX); 650 desiredvnodes = MAXVNODES_MAX; 651 } 652 wantfreevnodes = desiredvnodes / 4; 653 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 654 TAILQ_INIT(&vnode_list); 655 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF); 656 /* 657 * The lock is taken to appease WITNESS. 658 */ 659 mtx_lock(&vnode_list_mtx); 660 vnlru_recalc(); 661 mtx_unlock(&vnode_list_mtx); 662 vnode_list_free_marker = vn_alloc_marker(NULL); 663 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist); 664 vnode_list_reclaim_marker = vn_alloc_marker(NULL); 665 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist); 666 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 667 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 668 uma_zone_set_smr(vnode_zone, vfs_smr); 669 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 670 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 671 /* 672 * Preallocate enough nodes to support one-per buf so that 673 * we can not fail an insert. reassignbuf() callers can not 674 * tolerate the insertion failure. 675 */ 676 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 677 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 678 UMA_ZONE_NOFREE | UMA_ZONE_SMR); 679 buf_trie_smr = uma_zone_get_smr(buf_trie_zone); 680 uma_prealloc(buf_trie_zone, nbuf); 681 682 vnodes_created = counter_u64_alloc(M_WAITOK); 683 recycles_count = counter_u64_alloc(M_WAITOK); 684 recycles_free_count = counter_u64_alloc(M_WAITOK); 685 deferred_inact = counter_u64_alloc(M_WAITOK); 686 687 /* 688 * Initialize the filesystem syncer. 689 */ 690 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 691 &syncer_mask); 692 syncer_maxdelay = syncer_mask + 1; 693 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 694 cv_init(&sync_wakeup, "syncer"); 695 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 696 vnsz2log++; 697 vnsz2log--; 698 699 CPU_FOREACH(cpu) { 700 vd = DPCPU_ID_PTR((cpu), vd); 701 bzero(vd, sizeof(*vd)); 702 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF); 703 } 704 } 705 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 706 707 /* 708 * Mark a mount point as busy. Used to synchronize access and to delay 709 * unmounting. Eventually, mountlist_mtx is not released on failure. 710 * 711 * vfs_busy() is a custom lock, it can block the caller. 712 * vfs_busy() only sleeps if the unmount is active on the mount point. 713 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 714 * vnode belonging to mp. 715 * 716 * Lookup uses vfs_busy() to traverse mount points. 717 * root fs var fs 718 * / vnode lock A / vnode lock (/var) D 719 * /var vnode lock B /log vnode lock(/var/log) E 720 * vfs_busy lock C vfs_busy lock F 721 * 722 * Within each file system, the lock order is C->A->B and F->D->E. 723 * 724 * When traversing across mounts, the system follows that lock order: 725 * 726 * C->A->B 727 * | 728 * +->F->D->E 729 * 730 * The lookup() process for namei("/var") illustrates the process: 731 * VOP_LOOKUP() obtains B while A is held 732 * vfs_busy() obtains a shared lock on F while A and B are held 733 * vput() releases lock on B 734 * vput() releases lock on A 735 * VFS_ROOT() obtains lock on D while shared lock on F is held 736 * vfs_unbusy() releases shared lock on F 737 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 738 * Attempt to lock A (instead of vp_crossmp) while D is held would 739 * violate the global order, causing deadlocks. 740 * 741 * dounmount() locks B while F is drained. 742 */ 743 int 744 vfs_busy(struct mount *mp, int flags) 745 { 746 747 MPASS((flags & ~MBF_MASK) == 0); 748 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 749 750 if (vfs_op_thread_enter(mp)) { 751 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 752 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0); 753 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0); 754 vfs_mp_count_add_pcpu(mp, ref, 1); 755 vfs_mp_count_add_pcpu(mp, lockref, 1); 756 vfs_op_thread_exit(mp); 757 if (flags & MBF_MNTLSTLOCK) 758 mtx_unlock(&mountlist_mtx); 759 return (0); 760 } 761 762 MNT_ILOCK(mp); 763 vfs_assert_mount_counters(mp); 764 MNT_REF(mp); 765 /* 766 * If mount point is currently being unmounted, sleep until the 767 * mount point fate is decided. If thread doing the unmounting fails, 768 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 769 * that this mount point has survived the unmount attempt and vfs_busy 770 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 771 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 772 * about to be really destroyed. vfs_busy needs to release its 773 * reference on the mount point in this case and return with ENOENT, 774 * telling the caller that mount mount it tried to busy is no longer 775 * valid. 776 */ 777 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 778 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 779 MNT_REL(mp); 780 MNT_IUNLOCK(mp); 781 CTR1(KTR_VFS, "%s: failed busying before sleeping", 782 __func__); 783 return (ENOENT); 784 } 785 if (flags & MBF_MNTLSTLOCK) 786 mtx_unlock(&mountlist_mtx); 787 mp->mnt_kern_flag |= MNTK_MWAIT; 788 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 789 if (flags & MBF_MNTLSTLOCK) 790 mtx_lock(&mountlist_mtx); 791 MNT_ILOCK(mp); 792 } 793 if (flags & MBF_MNTLSTLOCK) 794 mtx_unlock(&mountlist_mtx); 795 mp->mnt_lockref++; 796 MNT_IUNLOCK(mp); 797 return (0); 798 } 799 800 /* 801 * Free a busy filesystem. 802 */ 803 void 804 vfs_unbusy(struct mount *mp) 805 { 806 int c; 807 808 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 809 810 if (vfs_op_thread_enter(mp)) { 811 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 812 vfs_mp_count_sub_pcpu(mp, lockref, 1); 813 vfs_mp_count_sub_pcpu(mp, ref, 1); 814 vfs_op_thread_exit(mp); 815 return; 816 } 817 818 MNT_ILOCK(mp); 819 vfs_assert_mount_counters(mp); 820 MNT_REL(mp); 821 c = --mp->mnt_lockref; 822 if (mp->mnt_vfs_ops == 0) { 823 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 824 MNT_IUNLOCK(mp); 825 return; 826 } 827 if (c < 0) 828 vfs_dump_mount_counters(mp); 829 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 830 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 831 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 832 mp->mnt_kern_flag &= ~MNTK_DRAINING; 833 wakeup(&mp->mnt_lockref); 834 } 835 MNT_IUNLOCK(mp); 836 } 837 838 /* 839 * Lookup a mount point by filesystem identifier. 840 */ 841 struct mount * 842 vfs_getvfs(fsid_t *fsid) 843 { 844 struct mount *mp; 845 846 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 847 mtx_lock(&mountlist_mtx); 848 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 849 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 850 vfs_ref(mp); 851 mtx_unlock(&mountlist_mtx); 852 return (mp); 853 } 854 } 855 mtx_unlock(&mountlist_mtx); 856 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 857 return ((struct mount *) 0); 858 } 859 860 /* 861 * Lookup a mount point by filesystem identifier, busying it before 862 * returning. 863 * 864 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 865 * cache for popular filesystem identifiers. The cache is lockess, using 866 * the fact that struct mount's are never freed. In worst case we may 867 * get pointer to unmounted or even different filesystem, so we have to 868 * check what we got, and go slow way if so. 869 */ 870 struct mount * 871 vfs_busyfs(fsid_t *fsid) 872 { 873 #define FSID_CACHE_SIZE 256 874 typedef struct mount * volatile vmp_t; 875 static vmp_t cache[FSID_CACHE_SIZE]; 876 struct mount *mp; 877 int error; 878 uint32_t hash; 879 880 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 881 hash = fsid->val[0] ^ fsid->val[1]; 882 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 883 mp = cache[hash]; 884 if (mp == NULL || fsidcmp(&mp->mnt_stat.f_fsid, fsid) != 0) 885 goto slow; 886 if (vfs_busy(mp, 0) != 0) { 887 cache[hash] = NULL; 888 goto slow; 889 } 890 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) 891 return (mp); 892 else 893 vfs_unbusy(mp); 894 895 slow: 896 mtx_lock(&mountlist_mtx); 897 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 898 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 899 error = vfs_busy(mp, MBF_MNTLSTLOCK); 900 if (error) { 901 cache[hash] = NULL; 902 mtx_unlock(&mountlist_mtx); 903 return (NULL); 904 } 905 cache[hash] = mp; 906 return (mp); 907 } 908 } 909 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 910 mtx_unlock(&mountlist_mtx); 911 return ((struct mount *) 0); 912 } 913 914 /* 915 * Check if a user can access privileged mount options. 916 */ 917 int 918 vfs_suser(struct mount *mp, struct thread *td) 919 { 920 int error; 921 922 if (jailed(td->td_ucred)) { 923 /* 924 * If the jail of the calling thread lacks permission for 925 * this type of file system, deny immediately. 926 */ 927 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 928 return (EPERM); 929 930 /* 931 * If the file system was mounted outside the jail of the 932 * calling thread, deny immediately. 933 */ 934 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 935 return (EPERM); 936 } 937 938 /* 939 * If file system supports delegated administration, we don't check 940 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 941 * by the file system itself. 942 * If this is not the user that did original mount, we check for 943 * the PRIV_VFS_MOUNT_OWNER privilege. 944 */ 945 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 946 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 947 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 948 return (error); 949 } 950 return (0); 951 } 952 953 /* 954 * Get a new unique fsid. Try to make its val[0] unique, since this value 955 * will be used to create fake device numbers for stat(). Also try (but 956 * not so hard) make its val[0] unique mod 2^16, since some emulators only 957 * support 16-bit device numbers. We end up with unique val[0]'s for the 958 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 959 * 960 * Keep in mind that several mounts may be running in parallel. Starting 961 * the search one past where the previous search terminated is both a 962 * micro-optimization and a defense against returning the same fsid to 963 * different mounts. 964 */ 965 void 966 vfs_getnewfsid(struct mount *mp) 967 { 968 static uint16_t mntid_base; 969 struct mount *nmp; 970 fsid_t tfsid; 971 int mtype; 972 973 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 974 mtx_lock(&mntid_mtx); 975 mtype = mp->mnt_vfc->vfc_typenum; 976 tfsid.val[1] = mtype; 977 mtype = (mtype & 0xFF) << 24; 978 for (;;) { 979 tfsid.val[0] = makedev(255, 980 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 981 mntid_base++; 982 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 983 break; 984 vfs_rel(nmp); 985 } 986 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 987 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 988 mtx_unlock(&mntid_mtx); 989 } 990 991 /* 992 * Knob to control the precision of file timestamps: 993 * 994 * 0 = seconds only; nanoseconds zeroed. 995 * 1 = seconds and nanoseconds, accurate within 1/HZ. 996 * 2 = seconds and nanoseconds, truncated to microseconds. 997 * >=3 = seconds and nanoseconds, maximum precision. 998 */ 999 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 1000 1001 static int timestamp_precision = TSP_USEC; 1002 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 1003 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 1004 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 1005 "3+: sec + ns (max. precision))"); 1006 1007 /* 1008 * Get a current timestamp. 1009 */ 1010 void 1011 vfs_timestamp(struct timespec *tsp) 1012 { 1013 struct timeval tv; 1014 1015 switch (timestamp_precision) { 1016 case TSP_SEC: 1017 tsp->tv_sec = time_second; 1018 tsp->tv_nsec = 0; 1019 break; 1020 case TSP_HZ: 1021 getnanotime(tsp); 1022 break; 1023 case TSP_USEC: 1024 microtime(&tv); 1025 TIMEVAL_TO_TIMESPEC(&tv, tsp); 1026 break; 1027 case TSP_NSEC: 1028 default: 1029 nanotime(tsp); 1030 break; 1031 } 1032 } 1033 1034 /* 1035 * Set vnode attributes to VNOVAL 1036 */ 1037 void 1038 vattr_null(struct vattr *vap) 1039 { 1040 1041 vap->va_type = VNON; 1042 vap->va_size = VNOVAL; 1043 vap->va_bytes = VNOVAL; 1044 vap->va_mode = VNOVAL; 1045 vap->va_nlink = VNOVAL; 1046 vap->va_uid = VNOVAL; 1047 vap->va_gid = VNOVAL; 1048 vap->va_fsid = VNOVAL; 1049 vap->va_fileid = VNOVAL; 1050 vap->va_blocksize = VNOVAL; 1051 vap->va_rdev = VNOVAL; 1052 vap->va_atime.tv_sec = VNOVAL; 1053 vap->va_atime.tv_nsec = VNOVAL; 1054 vap->va_mtime.tv_sec = VNOVAL; 1055 vap->va_mtime.tv_nsec = VNOVAL; 1056 vap->va_ctime.tv_sec = VNOVAL; 1057 vap->va_ctime.tv_nsec = VNOVAL; 1058 vap->va_birthtime.tv_sec = VNOVAL; 1059 vap->va_birthtime.tv_nsec = VNOVAL; 1060 vap->va_flags = VNOVAL; 1061 vap->va_gen = VNOVAL; 1062 vap->va_vaflags = 0; 1063 } 1064 1065 /* 1066 * Try to reduce the total number of vnodes. 1067 * 1068 * This routine (and its user) are buggy in at least the following ways: 1069 * - all parameters were picked years ago when RAM sizes were significantly 1070 * smaller 1071 * - it can pick vnodes based on pages used by the vm object, but filesystems 1072 * like ZFS don't use it making the pick broken 1073 * - since ZFS has its own aging policy it gets partially combated by this one 1074 * - a dedicated method should be provided for filesystems to let them decide 1075 * whether the vnode should be recycled 1076 * 1077 * This routine is called when we have too many vnodes. It attempts 1078 * to free <count> vnodes and will potentially free vnodes that still 1079 * have VM backing store (VM backing store is typically the cause 1080 * of a vnode blowout so we want to do this). Therefore, this operation 1081 * is not considered cheap. 1082 * 1083 * A number of conditions may prevent a vnode from being reclaimed. 1084 * the buffer cache may have references on the vnode, a directory 1085 * vnode may still have references due to the namei cache representing 1086 * underlying files, or the vnode may be in active use. It is not 1087 * desirable to reuse such vnodes. These conditions may cause the 1088 * number of vnodes to reach some minimum value regardless of what 1089 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 1090 * 1091 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 1092 * entries if this argument is strue 1093 * @param trigger Only reclaim vnodes with fewer than this many resident 1094 * pages. 1095 * @param target How many vnodes to reclaim. 1096 * @return The number of vnodes that were reclaimed. 1097 */ 1098 static int 1099 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target) 1100 { 1101 struct vnode *vp, *mvp; 1102 struct mount *mp; 1103 struct vm_object *object; 1104 u_long done; 1105 bool retried; 1106 1107 mtx_assert(&vnode_list_mtx, MA_OWNED); 1108 1109 retried = false; 1110 done = 0; 1111 1112 mvp = vnode_list_reclaim_marker; 1113 restart: 1114 vp = mvp; 1115 while (done < target) { 1116 vp = TAILQ_NEXT(vp, v_vnodelist); 1117 if (__predict_false(vp == NULL)) 1118 break; 1119 1120 if (__predict_false(vp->v_type == VMARKER)) 1121 continue; 1122 1123 /* 1124 * If it's been deconstructed already, it's still 1125 * referenced, or it exceeds the trigger, skip it. 1126 * Also skip free vnodes. We are trying to make space 1127 * to expand the free list, not reduce it. 1128 */ 1129 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1130 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src))) 1131 goto next_iter; 1132 1133 if (vp->v_type == VBAD || vp->v_type == VNON) 1134 goto next_iter; 1135 1136 if (!VI_TRYLOCK(vp)) 1137 goto next_iter; 1138 1139 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1140 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1141 VN_IS_DOOMED(vp) || vp->v_type == VNON) { 1142 VI_UNLOCK(vp); 1143 goto next_iter; 1144 } 1145 1146 object = atomic_load_ptr(&vp->v_object); 1147 if (object == NULL || object->resident_page_count > trigger) { 1148 VI_UNLOCK(vp); 1149 goto next_iter; 1150 } 1151 1152 vholdl(vp); 1153 VI_UNLOCK(vp); 1154 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1155 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1156 mtx_unlock(&vnode_list_mtx); 1157 1158 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1159 vdrop(vp); 1160 goto next_iter_unlocked; 1161 } 1162 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { 1163 vdrop(vp); 1164 vn_finished_write(mp); 1165 goto next_iter_unlocked; 1166 } 1167 1168 VI_LOCK(vp); 1169 if (vp->v_usecount > 0 || 1170 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1171 (vp->v_object != NULL && 1172 vp->v_object->resident_page_count > trigger)) { 1173 VOP_UNLOCK(vp); 1174 vdropl(vp); 1175 vn_finished_write(mp); 1176 goto next_iter_unlocked; 1177 } 1178 counter_u64_add(recycles_count, 1); 1179 vgonel(vp); 1180 VOP_UNLOCK(vp); 1181 vdropl(vp); 1182 vn_finished_write(mp); 1183 done++; 1184 next_iter_unlocked: 1185 if (should_yield()) 1186 kern_yield(PRI_USER); 1187 mtx_lock(&vnode_list_mtx); 1188 goto restart; 1189 next_iter: 1190 MPASS(vp->v_type != VMARKER); 1191 if (!should_yield()) 1192 continue; 1193 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1194 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1195 mtx_unlock(&vnode_list_mtx); 1196 kern_yield(PRI_USER); 1197 mtx_lock(&vnode_list_mtx); 1198 goto restart; 1199 } 1200 if (done == 0 && !retried) { 1201 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1202 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1203 retried = true; 1204 goto restart; 1205 } 1206 return (done); 1207 } 1208 1209 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1210 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1211 0, 1212 "limit on vnode free requests per call to the vnlru_free routine"); 1213 1214 /* 1215 * Attempt to reduce the free list by the requested amount. 1216 */ 1217 static int 1218 vnlru_free_locked(int count, struct vfsops *mnt_op) 1219 { 1220 struct vnode *vp, *mvp; 1221 struct mount *mp; 1222 int ocount; 1223 1224 mtx_assert(&vnode_list_mtx, MA_OWNED); 1225 if (count > max_vnlru_free) 1226 count = max_vnlru_free; 1227 ocount = count; 1228 mvp = vnode_list_free_marker; 1229 restart: 1230 vp = mvp; 1231 while (count > 0) { 1232 vp = TAILQ_NEXT(vp, v_vnodelist); 1233 if (__predict_false(vp == NULL)) { 1234 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1235 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist); 1236 break; 1237 } 1238 if (__predict_false(vp->v_type == VMARKER)) 1239 continue; 1240 1241 /* 1242 * Don't recycle if our vnode is from different type 1243 * of mount point. Note that mp is type-safe, the 1244 * check does not reach unmapped address even if 1245 * vnode is reclaimed. 1246 * Don't recycle if we can't get the interlock without 1247 * blocking. 1248 */ 1249 if (vp->v_holdcnt > 0 || (mnt_op != NULL && (mp = vp->v_mount) != NULL && 1250 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1251 continue; 1252 } 1253 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1254 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1255 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1256 VI_UNLOCK(vp); 1257 continue; 1258 } 1259 vholdl(vp); 1260 count--; 1261 mtx_unlock(&vnode_list_mtx); 1262 VI_UNLOCK(vp); 1263 vtryrecycle(vp); 1264 vdrop(vp); 1265 mtx_lock(&vnode_list_mtx); 1266 goto restart; 1267 } 1268 return (ocount - count); 1269 } 1270 1271 void 1272 vnlru_free(int count, struct vfsops *mnt_op) 1273 { 1274 1275 mtx_lock(&vnode_list_mtx); 1276 vnlru_free_locked(count, mnt_op); 1277 mtx_unlock(&vnode_list_mtx); 1278 } 1279 1280 static void 1281 vnlru_recalc(void) 1282 { 1283 1284 mtx_assert(&vnode_list_mtx, MA_OWNED); 1285 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1286 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1287 vlowat = vhiwat / 2; 1288 } 1289 1290 /* 1291 * Attempt to recycle vnodes in a context that is always safe to block. 1292 * Calling vlrurecycle() from the bowels of filesystem code has some 1293 * interesting deadlock problems. 1294 */ 1295 static struct proc *vnlruproc; 1296 static int vnlruproc_sig; 1297 1298 /* 1299 * The main freevnodes counter is only updated when threads requeue their vnode 1300 * batches. CPUs are conditionally walked to compute a more accurate total. 1301 * 1302 * Limit how much of a slop are we willing to tolerate. Note: the actual value 1303 * at any given moment can still exceed slop, but it should not be by significant 1304 * margin in practice. 1305 */ 1306 #define VNLRU_FREEVNODES_SLOP 128 1307 1308 static u_long 1309 vnlru_read_freevnodes(void) 1310 { 1311 struct vdbatch *vd; 1312 long slop; 1313 int cpu; 1314 1315 mtx_assert(&vnode_list_mtx, MA_OWNED); 1316 if (freevnodes > freevnodes_old) 1317 slop = freevnodes - freevnodes_old; 1318 else 1319 slop = freevnodes_old - freevnodes; 1320 if (slop < VNLRU_FREEVNODES_SLOP) 1321 return (freevnodes >= 0 ? freevnodes : 0); 1322 freevnodes_old = freevnodes; 1323 CPU_FOREACH(cpu) { 1324 vd = DPCPU_ID_PTR((cpu), vd); 1325 freevnodes_old += vd->freevnodes; 1326 } 1327 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1328 } 1329 1330 static bool 1331 vnlru_under(u_long rnumvnodes, u_long limit) 1332 { 1333 u_long rfreevnodes, space; 1334 1335 if (__predict_false(rnumvnodes > desiredvnodes)) 1336 return (true); 1337 1338 space = desiredvnodes - rnumvnodes; 1339 if (space < limit) { 1340 rfreevnodes = vnlru_read_freevnodes(); 1341 if (rfreevnodes > wantfreevnodes) 1342 space += rfreevnodes - wantfreevnodes; 1343 } 1344 return (space < limit); 1345 } 1346 1347 static bool 1348 vnlru_under_unlocked(u_long rnumvnodes, u_long limit) 1349 { 1350 long rfreevnodes, space; 1351 1352 if (__predict_false(rnumvnodes > desiredvnodes)) 1353 return (true); 1354 1355 space = desiredvnodes - rnumvnodes; 1356 if (space < limit) { 1357 rfreevnodes = atomic_load_long(&freevnodes); 1358 if (rfreevnodes > wantfreevnodes) 1359 space += rfreevnodes - wantfreevnodes; 1360 } 1361 return (space < limit); 1362 } 1363 1364 static void 1365 vnlru_kick(void) 1366 { 1367 1368 mtx_assert(&vnode_list_mtx, MA_OWNED); 1369 if (vnlruproc_sig == 0) { 1370 vnlruproc_sig = 1; 1371 wakeup(vnlruproc); 1372 } 1373 } 1374 1375 static void 1376 vnlru_proc(void) 1377 { 1378 u_long rnumvnodes, rfreevnodes, target; 1379 unsigned long onumvnodes; 1380 int done, force, trigger, usevnodes; 1381 bool reclaim_nc_src, want_reread; 1382 1383 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1384 SHUTDOWN_PRI_FIRST); 1385 1386 force = 0; 1387 want_reread = false; 1388 for (;;) { 1389 kproc_suspend_check(vnlruproc); 1390 mtx_lock(&vnode_list_mtx); 1391 rnumvnodes = atomic_load_long(&numvnodes); 1392 1393 if (want_reread) { 1394 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1395 want_reread = false; 1396 } 1397 1398 /* 1399 * If numvnodes is too large (due to desiredvnodes being 1400 * adjusted using its sysctl, or emergency growth), first 1401 * try to reduce it by discarding from the free list. 1402 */ 1403 if (rnumvnodes > desiredvnodes) { 1404 vnlru_free_locked(rnumvnodes - desiredvnodes, NULL); 1405 rnumvnodes = atomic_load_long(&numvnodes); 1406 } 1407 /* 1408 * Sleep if the vnode cache is in a good state. This is 1409 * when it is not over-full and has space for about a 4% 1410 * or 9% expansion (by growing its size or inexcessively 1411 * reducing its free list). Otherwise, try to reclaim 1412 * space for a 10% expansion. 1413 */ 1414 if (vstir && force == 0) { 1415 force = 1; 1416 vstir = 0; 1417 } 1418 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1419 vnlruproc_sig = 0; 1420 wakeup(&vnlruproc_sig); 1421 msleep(vnlruproc, &vnode_list_mtx, 1422 PVFS|PDROP, "vlruwt", hz); 1423 continue; 1424 } 1425 rfreevnodes = vnlru_read_freevnodes(); 1426 1427 onumvnodes = rnumvnodes; 1428 /* 1429 * Calculate parameters for recycling. These are the same 1430 * throughout the loop to give some semblance of fairness. 1431 * The trigger point is to avoid recycling vnodes with lots 1432 * of resident pages. We aren't trying to free memory; we 1433 * are trying to recycle or at least free vnodes. 1434 */ 1435 if (rnumvnodes <= desiredvnodes) 1436 usevnodes = rnumvnodes - rfreevnodes; 1437 else 1438 usevnodes = rnumvnodes; 1439 if (usevnodes <= 0) 1440 usevnodes = 1; 1441 /* 1442 * The trigger value is is chosen to give a conservatively 1443 * large value to ensure that it alone doesn't prevent 1444 * making progress. The value can easily be so large that 1445 * it is effectively infinite in some congested and 1446 * misconfigured cases, and this is necessary. Normally 1447 * it is about 8 to 100 (pages), which is quite large. 1448 */ 1449 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1450 if (force < 2) 1451 trigger = vsmalltrigger; 1452 reclaim_nc_src = force >= 3; 1453 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1454 target = target / 10 + 1; 1455 done = vlrureclaim(reclaim_nc_src, trigger, target); 1456 mtx_unlock(&vnode_list_mtx); 1457 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1458 uma_reclaim(UMA_RECLAIM_DRAIN); 1459 if (done == 0) { 1460 if (force == 0 || force == 1) { 1461 force = 2; 1462 continue; 1463 } 1464 if (force == 2) { 1465 force = 3; 1466 continue; 1467 } 1468 want_reread = true; 1469 force = 0; 1470 vnlru_nowhere++; 1471 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1472 } else { 1473 want_reread = true; 1474 kern_yield(PRI_USER); 1475 } 1476 } 1477 } 1478 1479 static struct kproc_desc vnlru_kp = { 1480 "vnlru", 1481 vnlru_proc, 1482 &vnlruproc 1483 }; 1484 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1485 &vnlru_kp); 1486 1487 /* 1488 * Routines having to do with the management of the vnode table. 1489 */ 1490 1491 /* 1492 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1493 * before we actually vgone(). This function must be called with the vnode 1494 * held to prevent the vnode from being returned to the free list midway 1495 * through vgone(). 1496 */ 1497 static int 1498 vtryrecycle(struct vnode *vp) 1499 { 1500 struct mount *vnmp; 1501 1502 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1503 VNASSERT(vp->v_holdcnt, vp, 1504 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1505 /* 1506 * This vnode may found and locked via some other list, if so we 1507 * can't recycle it yet. 1508 */ 1509 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1510 CTR2(KTR_VFS, 1511 "%s: impossible to recycle, vp %p lock is already held", 1512 __func__, vp); 1513 return (EWOULDBLOCK); 1514 } 1515 /* 1516 * Don't recycle if its filesystem is being suspended. 1517 */ 1518 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1519 VOP_UNLOCK(vp); 1520 CTR2(KTR_VFS, 1521 "%s: impossible to recycle, cannot start the write for %p", 1522 __func__, vp); 1523 return (EBUSY); 1524 } 1525 /* 1526 * If we got this far, we need to acquire the interlock and see if 1527 * anyone picked up this vnode from another list. If not, we will 1528 * mark it with DOOMED via vgonel() so that anyone who does find it 1529 * will skip over it. 1530 */ 1531 VI_LOCK(vp); 1532 if (vp->v_usecount) { 1533 VOP_UNLOCK(vp); 1534 VI_UNLOCK(vp); 1535 vn_finished_write(vnmp); 1536 CTR2(KTR_VFS, 1537 "%s: impossible to recycle, %p is already referenced", 1538 __func__, vp); 1539 return (EBUSY); 1540 } 1541 if (!VN_IS_DOOMED(vp)) { 1542 counter_u64_add(recycles_free_count, 1); 1543 vgonel(vp); 1544 } 1545 VOP_UNLOCK(vp); 1546 VI_UNLOCK(vp); 1547 vn_finished_write(vnmp); 1548 return (0); 1549 } 1550 1551 /* 1552 * Allocate a new vnode. 1553 * 1554 * The operation never returns an error. Returning an error was disabled 1555 * in r145385 (dated 2005) with the following comment: 1556 * 1557 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1558 * 1559 * Given the age of this commit (almost 15 years at the time of writing this 1560 * comment) restoring the ability to fail requires a significant audit of 1561 * all codepaths. 1562 * 1563 * The routine can try to free a vnode or stall for up to 1 second waiting for 1564 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1565 */ 1566 static u_long vn_alloc_cyclecount; 1567 1568 static struct vnode * __noinline 1569 vn_alloc_hard(struct mount *mp) 1570 { 1571 u_long rnumvnodes, rfreevnodes; 1572 1573 mtx_lock(&vnode_list_mtx); 1574 rnumvnodes = atomic_load_long(&numvnodes); 1575 if (rnumvnodes + 1 < desiredvnodes) { 1576 vn_alloc_cyclecount = 0; 1577 goto alloc; 1578 } 1579 rfreevnodes = vnlru_read_freevnodes(); 1580 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1581 vn_alloc_cyclecount = 0; 1582 vstir = 1; 1583 } 1584 /* 1585 * Grow the vnode cache if it will not be above its target max 1586 * after growing. Otherwise, if the free list is nonempty, try 1587 * to reclaim 1 item from it before growing the cache (possibly 1588 * above its target max if the reclamation failed or is delayed). 1589 * Otherwise, wait for some space. In all cases, schedule 1590 * vnlru_proc() if we are getting short of space. The watermarks 1591 * should be chosen so that we never wait or even reclaim from 1592 * the free list to below its target minimum. 1593 */ 1594 if (vnlru_free_locked(1, NULL) > 0) 1595 goto alloc; 1596 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1597 /* 1598 * Wait for space for a new vnode. 1599 */ 1600 vnlru_kick(); 1601 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1602 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1603 vnlru_read_freevnodes() > 1) 1604 vnlru_free_locked(1, NULL); 1605 } 1606 alloc: 1607 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1608 if (vnlru_under(rnumvnodes, vlowat)) 1609 vnlru_kick(); 1610 mtx_unlock(&vnode_list_mtx); 1611 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 1612 } 1613 1614 static struct vnode * 1615 vn_alloc(struct mount *mp) 1616 { 1617 u_long rnumvnodes; 1618 1619 if (__predict_false(vn_alloc_cyclecount != 0)) 1620 return (vn_alloc_hard(mp)); 1621 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1622 if (__predict_false(vnlru_under_unlocked(rnumvnodes, vlowat))) { 1623 atomic_subtract_long(&numvnodes, 1); 1624 return (vn_alloc_hard(mp)); 1625 } 1626 1627 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 1628 } 1629 1630 static void 1631 vn_free(struct vnode *vp) 1632 { 1633 1634 atomic_subtract_long(&numvnodes, 1); 1635 uma_zfree_smr(vnode_zone, vp); 1636 } 1637 1638 /* 1639 * Return the next vnode from the free list. 1640 */ 1641 int 1642 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1643 struct vnode **vpp) 1644 { 1645 struct vnode *vp; 1646 struct thread *td; 1647 struct lock_object *lo; 1648 1649 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1650 1651 KASSERT(vops->registered, 1652 ("%s: not registered vector op %p\n", __func__, vops)); 1653 1654 td = curthread; 1655 if (td->td_vp_reserved != NULL) { 1656 vp = td->td_vp_reserved; 1657 td->td_vp_reserved = NULL; 1658 } else { 1659 vp = vn_alloc(mp); 1660 } 1661 counter_u64_add(vnodes_created, 1); 1662 /* 1663 * Locks are given the generic name "vnode" when created. 1664 * Follow the historic practice of using the filesystem 1665 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1666 * 1667 * Locks live in a witness group keyed on their name. Thus, 1668 * when a lock is renamed, it must also move from the witness 1669 * group of its old name to the witness group of its new name. 1670 * 1671 * The change only needs to be made when the vnode moves 1672 * from one filesystem type to another. We ensure that each 1673 * filesystem use a single static name pointer for its tag so 1674 * that we can compare pointers rather than doing a strcmp(). 1675 */ 1676 lo = &vp->v_vnlock->lock_object; 1677 #ifdef WITNESS 1678 if (lo->lo_name != tag) { 1679 #endif 1680 lo->lo_name = tag; 1681 #ifdef WITNESS 1682 WITNESS_DESTROY(lo); 1683 WITNESS_INIT(lo, tag); 1684 } 1685 #endif 1686 /* 1687 * By default, don't allow shared locks unless filesystems opt-in. 1688 */ 1689 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1690 /* 1691 * Finalize various vnode identity bits. 1692 */ 1693 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1694 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1695 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1696 vp->v_type = VNON; 1697 vp->v_op = vops; 1698 v_init_counters(vp); 1699 vp->v_bufobj.bo_ops = &buf_ops_bio; 1700 #ifdef DIAGNOSTIC 1701 if (mp == NULL && vops != &dead_vnodeops) 1702 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1703 #endif 1704 #ifdef MAC 1705 mac_vnode_init(vp); 1706 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1707 mac_vnode_associate_singlelabel(mp, vp); 1708 #endif 1709 if (mp != NULL) { 1710 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1711 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1712 vp->v_vflag |= VV_NOKNOTE; 1713 } 1714 1715 /* 1716 * For the filesystems which do not use vfs_hash_insert(), 1717 * still initialize v_hash to have vfs_hash_index() useful. 1718 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1719 * its own hashing. 1720 */ 1721 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1722 1723 *vpp = vp; 1724 return (0); 1725 } 1726 1727 void 1728 getnewvnode_reserve(void) 1729 { 1730 struct thread *td; 1731 1732 td = curthread; 1733 MPASS(td->td_vp_reserved == NULL); 1734 td->td_vp_reserved = vn_alloc(NULL); 1735 } 1736 1737 void 1738 getnewvnode_drop_reserve(void) 1739 { 1740 struct thread *td; 1741 1742 td = curthread; 1743 if (td->td_vp_reserved != NULL) { 1744 vn_free(td->td_vp_reserved); 1745 td->td_vp_reserved = NULL; 1746 } 1747 } 1748 1749 static void 1750 freevnode(struct vnode *vp) 1751 { 1752 struct bufobj *bo; 1753 1754 /* 1755 * The vnode has been marked for destruction, so free it. 1756 * 1757 * The vnode will be returned to the zone where it will 1758 * normally remain until it is needed for another vnode. We 1759 * need to cleanup (or verify that the cleanup has already 1760 * been done) any residual data left from its current use 1761 * so as not to contaminate the freshly allocated vnode. 1762 */ 1763 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1764 /* 1765 * Paired with vgone. 1766 */ 1767 vn_seqc_write_end_locked(vp); 1768 VNPASS(vp->v_seqc_users == 0, vp); 1769 1770 bo = &vp->v_bufobj; 1771 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1772 VNPASS(vp->v_holdcnt == VHOLD_NO_SMR, vp); 1773 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1774 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1775 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1776 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1777 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1778 ("clean blk trie not empty")); 1779 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1780 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1781 ("dirty blk trie not empty")); 1782 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1783 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1784 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1785 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1786 ("Dangling rangelock waiters")); 1787 VI_UNLOCK(vp); 1788 #ifdef MAC 1789 mac_vnode_destroy(vp); 1790 #endif 1791 if (vp->v_pollinfo != NULL) { 1792 destroy_vpollinfo(vp->v_pollinfo); 1793 vp->v_pollinfo = NULL; 1794 } 1795 #ifdef INVARIANTS 1796 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1797 vp->v_op = NULL; 1798 #endif 1799 vp->v_mountedhere = NULL; 1800 vp->v_unpcb = NULL; 1801 vp->v_rdev = NULL; 1802 vp->v_fifoinfo = NULL; 1803 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1804 vp->v_irflag = 0; 1805 vp->v_iflag = 0; 1806 vp->v_vflag = 0; 1807 bo->bo_flag = 0; 1808 vn_free(vp); 1809 } 1810 1811 /* 1812 * Delete from old mount point vnode list, if on one. 1813 */ 1814 static void 1815 delmntque(struct vnode *vp) 1816 { 1817 struct mount *mp; 1818 1819 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 1820 1821 mp = vp->v_mount; 1822 if (mp == NULL) 1823 return; 1824 MNT_ILOCK(mp); 1825 VI_LOCK(vp); 1826 vp->v_mount = NULL; 1827 VI_UNLOCK(vp); 1828 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1829 ("bad mount point vnode list size")); 1830 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1831 mp->mnt_nvnodelistsize--; 1832 MNT_REL(mp); 1833 MNT_IUNLOCK(mp); 1834 } 1835 1836 static void 1837 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1838 { 1839 1840 vp->v_data = NULL; 1841 vp->v_op = &dead_vnodeops; 1842 vgone(vp); 1843 vput(vp); 1844 } 1845 1846 /* 1847 * Insert into list of vnodes for the new mount point, if available. 1848 */ 1849 int 1850 insmntque1(struct vnode *vp, struct mount *mp, 1851 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1852 { 1853 1854 KASSERT(vp->v_mount == NULL, 1855 ("insmntque: vnode already on per mount vnode list")); 1856 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1857 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1858 1859 /* 1860 * We acquire the vnode interlock early to ensure that the 1861 * vnode cannot be recycled by another process releasing a 1862 * holdcnt on it before we get it on both the vnode list 1863 * and the active vnode list. The mount mutex protects only 1864 * manipulation of the vnode list and the vnode freelist 1865 * mutex protects only manipulation of the active vnode list. 1866 * Hence the need to hold the vnode interlock throughout. 1867 */ 1868 MNT_ILOCK(mp); 1869 VI_LOCK(vp); 1870 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1871 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1872 mp->mnt_nvnodelistsize == 0)) && 1873 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1874 VI_UNLOCK(vp); 1875 MNT_IUNLOCK(mp); 1876 if (dtr != NULL) 1877 dtr(vp, dtr_arg); 1878 return (EBUSY); 1879 } 1880 vp->v_mount = mp; 1881 MNT_REF(mp); 1882 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1883 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1884 ("neg mount point vnode list size")); 1885 mp->mnt_nvnodelistsize++; 1886 VI_UNLOCK(vp); 1887 MNT_IUNLOCK(mp); 1888 return (0); 1889 } 1890 1891 int 1892 insmntque(struct vnode *vp, struct mount *mp) 1893 { 1894 1895 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1896 } 1897 1898 /* 1899 * Flush out and invalidate all buffers associated with a bufobj 1900 * Called with the underlying object locked. 1901 */ 1902 int 1903 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1904 { 1905 int error; 1906 1907 BO_LOCK(bo); 1908 if (flags & V_SAVE) { 1909 error = bufobj_wwait(bo, slpflag, slptimeo); 1910 if (error) { 1911 BO_UNLOCK(bo); 1912 return (error); 1913 } 1914 if (bo->bo_dirty.bv_cnt > 0) { 1915 BO_UNLOCK(bo); 1916 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1917 return (error); 1918 /* 1919 * XXX We could save a lock/unlock if this was only 1920 * enabled under INVARIANTS 1921 */ 1922 BO_LOCK(bo); 1923 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1924 panic("vinvalbuf: dirty bufs"); 1925 } 1926 } 1927 /* 1928 * If you alter this loop please notice that interlock is dropped and 1929 * reacquired in flushbuflist. Special care is needed to ensure that 1930 * no race conditions occur from this. 1931 */ 1932 do { 1933 error = flushbuflist(&bo->bo_clean, 1934 flags, bo, slpflag, slptimeo); 1935 if (error == 0 && !(flags & V_CLEANONLY)) 1936 error = flushbuflist(&bo->bo_dirty, 1937 flags, bo, slpflag, slptimeo); 1938 if (error != 0 && error != EAGAIN) { 1939 BO_UNLOCK(bo); 1940 return (error); 1941 } 1942 } while (error != 0); 1943 1944 /* 1945 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1946 * have write I/O in-progress but if there is a VM object then the 1947 * VM object can also have read-I/O in-progress. 1948 */ 1949 do { 1950 bufobj_wwait(bo, 0, 0); 1951 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1952 BO_UNLOCK(bo); 1953 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1954 BO_LOCK(bo); 1955 } 1956 } while (bo->bo_numoutput > 0); 1957 BO_UNLOCK(bo); 1958 1959 /* 1960 * Destroy the copy in the VM cache, too. 1961 */ 1962 if (bo->bo_object != NULL && 1963 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1964 VM_OBJECT_WLOCK(bo->bo_object); 1965 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1966 OBJPR_CLEANONLY : 0); 1967 VM_OBJECT_WUNLOCK(bo->bo_object); 1968 } 1969 1970 #ifdef INVARIANTS 1971 BO_LOCK(bo); 1972 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1973 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1974 bo->bo_clean.bv_cnt > 0)) 1975 panic("vinvalbuf: flush failed"); 1976 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1977 bo->bo_dirty.bv_cnt > 0) 1978 panic("vinvalbuf: flush dirty failed"); 1979 BO_UNLOCK(bo); 1980 #endif 1981 return (0); 1982 } 1983 1984 /* 1985 * Flush out and invalidate all buffers associated with a vnode. 1986 * Called with the underlying object locked. 1987 */ 1988 int 1989 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1990 { 1991 1992 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1993 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1994 if (vp->v_object != NULL && vp->v_object->handle != vp) 1995 return (0); 1996 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1997 } 1998 1999 /* 2000 * Flush out buffers on the specified list. 2001 * 2002 */ 2003 static int 2004 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 2005 int slptimeo) 2006 { 2007 struct buf *bp, *nbp; 2008 int retval, error; 2009 daddr_t lblkno; 2010 b_xflags_t xflags; 2011 2012 ASSERT_BO_WLOCKED(bo); 2013 2014 retval = 0; 2015 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2016 /* 2017 * If we are flushing both V_NORMAL and V_ALT buffers then 2018 * do not skip any buffers. If we are flushing only V_NORMAL 2019 * buffers then skip buffers marked as BX_ALTDATA. If we are 2020 * flushing only V_ALT buffers then skip buffers not marked 2021 * as BX_ALTDATA. 2022 */ 2023 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2024 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2025 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2026 continue; 2027 } 2028 if (nbp != NULL) { 2029 lblkno = nbp->b_lblkno; 2030 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2031 } 2032 retval = EAGAIN; 2033 error = BUF_TIMELOCK(bp, 2034 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2035 "flushbuf", slpflag, slptimeo); 2036 if (error) { 2037 BO_LOCK(bo); 2038 return (error != ENOLCK ? error : EAGAIN); 2039 } 2040 KASSERT(bp->b_bufobj == bo, 2041 ("bp %p wrong b_bufobj %p should be %p", 2042 bp, bp->b_bufobj, bo)); 2043 /* 2044 * XXX Since there are no node locks for NFS, I 2045 * believe there is a slight chance that a delayed 2046 * write will occur while sleeping just above, so 2047 * check for it. 2048 */ 2049 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2050 (flags & V_SAVE)) { 2051 bremfree(bp); 2052 bp->b_flags |= B_ASYNC; 2053 bwrite(bp); 2054 BO_LOCK(bo); 2055 return (EAGAIN); /* XXX: why not loop ? */ 2056 } 2057 bremfree(bp); 2058 bp->b_flags |= (B_INVAL | B_RELBUF); 2059 bp->b_flags &= ~B_ASYNC; 2060 brelse(bp); 2061 BO_LOCK(bo); 2062 if (nbp == NULL) 2063 break; 2064 nbp = gbincore(bo, lblkno); 2065 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2066 != xflags) 2067 break; /* nbp invalid */ 2068 } 2069 return (retval); 2070 } 2071 2072 int 2073 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2074 { 2075 struct buf *bp; 2076 int error; 2077 daddr_t lblkno; 2078 2079 ASSERT_BO_LOCKED(bo); 2080 2081 for (lblkno = startn;;) { 2082 again: 2083 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2084 if (bp == NULL || bp->b_lblkno >= endn || 2085 bp->b_lblkno < startn) 2086 break; 2087 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2088 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2089 if (error != 0) { 2090 BO_RLOCK(bo); 2091 if (error == ENOLCK) 2092 goto again; 2093 return (error); 2094 } 2095 KASSERT(bp->b_bufobj == bo, 2096 ("bp %p wrong b_bufobj %p should be %p", 2097 bp, bp->b_bufobj, bo)); 2098 lblkno = bp->b_lblkno + 1; 2099 if ((bp->b_flags & B_MANAGED) == 0) 2100 bremfree(bp); 2101 bp->b_flags |= B_RELBUF; 2102 /* 2103 * In the VMIO case, use the B_NOREUSE flag to hint that the 2104 * pages backing each buffer in the range are unlikely to be 2105 * reused. Dirty buffers will have the hint applied once 2106 * they've been written. 2107 */ 2108 if ((bp->b_flags & B_VMIO) != 0) 2109 bp->b_flags |= B_NOREUSE; 2110 brelse(bp); 2111 BO_RLOCK(bo); 2112 } 2113 return (0); 2114 } 2115 2116 /* 2117 * Truncate a file's buffer and pages to a specified length. This 2118 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2119 * sync activity. 2120 */ 2121 int 2122 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2123 { 2124 struct buf *bp, *nbp; 2125 struct bufobj *bo; 2126 daddr_t startlbn; 2127 2128 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2129 vp, blksize, (uintmax_t)length); 2130 2131 /* 2132 * Round up to the *next* lbn. 2133 */ 2134 startlbn = howmany(length, blksize); 2135 2136 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2137 2138 bo = &vp->v_bufobj; 2139 restart_unlocked: 2140 BO_LOCK(bo); 2141 2142 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2143 ; 2144 2145 if (length > 0) { 2146 restartsync: 2147 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2148 if (bp->b_lblkno > 0) 2149 continue; 2150 /* 2151 * Since we hold the vnode lock this should only 2152 * fail if we're racing with the buf daemon. 2153 */ 2154 if (BUF_LOCK(bp, 2155 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2156 BO_LOCKPTR(bo)) == ENOLCK) 2157 goto restart_unlocked; 2158 2159 VNASSERT((bp->b_flags & B_DELWRI), vp, 2160 ("buf(%p) on dirty queue without DELWRI", bp)); 2161 2162 bremfree(bp); 2163 bawrite(bp); 2164 BO_LOCK(bo); 2165 goto restartsync; 2166 } 2167 } 2168 2169 bufobj_wwait(bo, 0, 0); 2170 BO_UNLOCK(bo); 2171 vnode_pager_setsize(vp, length); 2172 2173 return (0); 2174 } 2175 2176 /* 2177 * Invalidate the cached pages of a file's buffer within the range of block 2178 * numbers [startlbn, endlbn). 2179 */ 2180 void 2181 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2182 int blksize) 2183 { 2184 struct bufobj *bo; 2185 off_t start, end; 2186 2187 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2188 2189 start = blksize * startlbn; 2190 end = blksize * endlbn; 2191 2192 bo = &vp->v_bufobj; 2193 BO_LOCK(bo); 2194 MPASS(blksize == bo->bo_bsize); 2195 2196 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2197 ; 2198 2199 BO_UNLOCK(bo); 2200 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2201 } 2202 2203 static int 2204 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2205 daddr_t startlbn, daddr_t endlbn) 2206 { 2207 struct buf *bp, *nbp; 2208 bool anyfreed; 2209 2210 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2211 ASSERT_BO_LOCKED(bo); 2212 2213 do { 2214 anyfreed = false; 2215 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2216 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2217 continue; 2218 if (BUF_LOCK(bp, 2219 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2220 BO_LOCKPTR(bo)) == ENOLCK) { 2221 BO_LOCK(bo); 2222 return (EAGAIN); 2223 } 2224 2225 bremfree(bp); 2226 bp->b_flags |= B_INVAL | B_RELBUF; 2227 bp->b_flags &= ~B_ASYNC; 2228 brelse(bp); 2229 anyfreed = true; 2230 2231 BO_LOCK(bo); 2232 if (nbp != NULL && 2233 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2234 nbp->b_vp != vp || 2235 (nbp->b_flags & B_DELWRI) != 0)) 2236 return (EAGAIN); 2237 } 2238 2239 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2240 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2241 continue; 2242 if (BUF_LOCK(bp, 2243 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2244 BO_LOCKPTR(bo)) == ENOLCK) { 2245 BO_LOCK(bo); 2246 return (EAGAIN); 2247 } 2248 bremfree(bp); 2249 bp->b_flags |= B_INVAL | B_RELBUF; 2250 bp->b_flags &= ~B_ASYNC; 2251 brelse(bp); 2252 anyfreed = true; 2253 2254 BO_LOCK(bo); 2255 if (nbp != NULL && 2256 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2257 (nbp->b_vp != vp) || 2258 (nbp->b_flags & B_DELWRI) == 0)) 2259 return (EAGAIN); 2260 } 2261 } while (anyfreed); 2262 return (0); 2263 } 2264 2265 static void 2266 buf_vlist_remove(struct buf *bp) 2267 { 2268 struct bufv *bv; 2269 2270 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2271 ASSERT_BO_WLOCKED(bp->b_bufobj); 2272 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 2273 (BX_VNDIRTY|BX_VNCLEAN), 2274 ("buf_vlist_remove: Buf %p is on two lists", bp)); 2275 if (bp->b_xflags & BX_VNDIRTY) 2276 bv = &bp->b_bufobj->bo_dirty; 2277 else 2278 bv = &bp->b_bufobj->bo_clean; 2279 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2280 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2281 bv->bv_cnt--; 2282 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2283 } 2284 2285 /* 2286 * Add the buffer to the sorted clean or dirty block list. 2287 * 2288 * NOTE: xflags is passed as a constant, optimizing this inline function! 2289 */ 2290 static void 2291 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2292 { 2293 struct bufv *bv; 2294 struct buf *n; 2295 int error; 2296 2297 ASSERT_BO_WLOCKED(bo); 2298 KASSERT((bo->bo_flag & BO_NOBUFS) == 0, 2299 ("buf_vlist_add: bo %p does not allow bufs", bo)); 2300 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2301 ("dead bo %p", bo)); 2302 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2303 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2304 bp->b_xflags |= xflags; 2305 if (xflags & BX_VNDIRTY) 2306 bv = &bo->bo_dirty; 2307 else 2308 bv = &bo->bo_clean; 2309 2310 /* 2311 * Keep the list ordered. Optimize empty list insertion. Assume 2312 * we tend to grow at the tail so lookup_le should usually be cheaper 2313 * than _ge. 2314 */ 2315 if (bv->bv_cnt == 0 || 2316 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2317 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2318 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2319 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2320 else 2321 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2322 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2323 if (error) 2324 panic("buf_vlist_add: Preallocated nodes insufficient."); 2325 bv->bv_cnt++; 2326 } 2327 2328 /* 2329 * Look up a buffer using the buffer tries. 2330 */ 2331 struct buf * 2332 gbincore(struct bufobj *bo, daddr_t lblkno) 2333 { 2334 struct buf *bp; 2335 2336 ASSERT_BO_LOCKED(bo); 2337 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2338 if (bp != NULL) 2339 return (bp); 2340 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno)); 2341 } 2342 2343 /* 2344 * Look up a buf using the buffer tries, without the bufobj lock. This relies 2345 * on SMR for safe lookup, and bufs being in a no-free zone to provide type 2346 * stability of the result. Like other lockless lookups, the found buf may 2347 * already be invalid by the time this function returns. 2348 */ 2349 struct buf * 2350 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno) 2351 { 2352 struct buf *bp; 2353 2354 ASSERT_BO_UNLOCKED(bo); 2355 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno); 2356 if (bp != NULL) 2357 return (bp); 2358 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno)); 2359 } 2360 2361 /* 2362 * Associate a buffer with a vnode. 2363 */ 2364 void 2365 bgetvp(struct vnode *vp, struct buf *bp) 2366 { 2367 struct bufobj *bo; 2368 2369 bo = &vp->v_bufobj; 2370 ASSERT_BO_WLOCKED(bo); 2371 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2372 2373 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2374 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2375 ("bgetvp: bp already attached! %p", bp)); 2376 2377 vhold(vp); 2378 bp->b_vp = vp; 2379 bp->b_bufobj = bo; 2380 /* 2381 * Insert onto list for new vnode. 2382 */ 2383 buf_vlist_add(bp, bo, BX_VNCLEAN); 2384 } 2385 2386 /* 2387 * Disassociate a buffer from a vnode. 2388 */ 2389 void 2390 brelvp(struct buf *bp) 2391 { 2392 struct bufobj *bo; 2393 struct vnode *vp; 2394 2395 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2396 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2397 2398 /* 2399 * Delete from old vnode list, if on one. 2400 */ 2401 vp = bp->b_vp; /* XXX */ 2402 bo = bp->b_bufobj; 2403 BO_LOCK(bo); 2404 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2405 buf_vlist_remove(bp); 2406 else 2407 panic("brelvp: Buffer %p not on queue.", bp); 2408 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2409 bo->bo_flag &= ~BO_ONWORKLST; 2410 mtx_lock(&sync_mtx); 2411 LIST_REMOVE(bo, bo_synclist); 2412 syncer_worklist_len--; 2413 mtx_unlock(&sync_mtx); 2414 } 2415 bp->b_vp = NULL; 2416 bp->b_bufobj = NULL; 2417 BO_UNLOCK(bo); 2418 vdrop(vp); 2419 } 2420 2421 /* 2422 * Add an item to the syncer work queue. 2423 */ 2424 static void 2425 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2426 { 2427 int slot; 2428 2429 ASSERT_BO_WLOCKED(bo); 2430 2431 mtx_lock(&sync_mtx); 2432 if (bo->bo_flag & BO_ONWORKLST) 2433 LIST_REMOVE(bo, bo_synclist); 2434 else { 2435 bo->bo_flag |= BO_ONWORKLST; 2436 syncer_worklist_len++; 2437 } 2438 2439 if (delay > syncer_maxdelay - 2) 2440 delay = syncer_maxdelay - 2; 2441 slot = (syncer_delayno + delay) & syncer_mask; 2442 2443 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2444 mtx_unlock(&sync_mtx); 2445 } 2446 2447 static int 2448 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2449 { 2450 int error, len; 2451 2452 mtx_lock(&sync_mtx); 2453 len = syncer_worklist_len - sync_vnode_count; 2454 mtx_unlock(&sync_mtx); 2455 error = SYSCTL_OUT(req, &len, sizeof(len)); 2456 return (error); 2457 } 2458 2459 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2460 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2461 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2462 2463 static struct proc *updateproc; 2464 static void sched_sync(void); 2465 static struct kproc_desc up_kp = { 2466 "syncer", 2467 sched_sync, 2468 &updateproc 2469 }; 2470 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2471 2472 static int 2473 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2474 { 2475 struct vnode *vp; 2476 struct mount *mp; 2477 2478 *bo = LIST_FIRST(slp); 2479 if (*bo == NULL) 2480 return (0); 2481 vp = bo2vnode(*bo); 2482 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2483 return (1); 2484 /* 2485 * We use vhold in case the vnode does not 2486 * successfully sync. vhold prevents the vnode from 2487 * going away when we unlock the sync_mtx so that 2488 * we can acquire the vnode interlock. 2489 */ 2490 vholdl(vp); 2491 mtx_unlock(&sync_mtx); 2492 VI_UNLOCK(vp); 2493 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2494 vdrop(vp); 2495 mtx_lock(&sync_mtx); 2496 return (*bo == LIST_FIRST(slp)); 2497 } 2498 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2499 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2500 VOP_UNLOCK(vp); 2501 vn_finished_write(mp); 2502 BO_LOCK(*bo); 2503 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2504 /* 2505 * Put us back on the worklist. The worklist 2506 * routine will remove us from our current 2507 * position and then add us back in at a later 2508 * position. 2509 */ 2510 vn_syncer_add_to_worklist(*bo, syncdelay); 2511 } 2512 BO_UNLOCK(*bo); 2513 vdrop(vp); 2514 mtx_lock(&sync_mtx); 2515 return (0); 2516 } 2517 2518 static int first_printf = 1; 2519 2520 /* 2521 * System filesystem synchronizer daemon. 2522 */ 2523 static void 2524 sched_sync(void) 2525 { 2526 struct synclist *next, *slp; 2527 struct bufobj *bo; 2528 long starttime; 2529 struct thread *td = curthread; 2530 int last_work_seen; 2531 int net_worklist_len; 2532 int syncer_final_iter; 2533 int error; 2534 2535 last_work_seen = 0; 2536 syncer_final_iter = 0; 2537 syncer_state = SYNCER_RUNNING; 2538 starttime = time_uptime; 2539 td->td_pflags |= TDP_NORUNNINGBUF; 2540 2541 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2542 SHUTDOWN_PRI_LAST); 2543 2544 mtx_lock(&sync_mtx); 2545 for (;;) { 2546 if (syncer_state == SYNCER_FINAL_DELAY && 2547 syncer_final_iter == 0) { 2548 mtx_unlock(&sync_mtx); 2549 kproc_suspend_check(td->td_proc); 2550 mtx_lock(&sync_mtx); 2551 } 2552 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2553 if (syncer_state != SYNCER_RUNNING && 2554 starttime != time_uptime) { 2555 if (first_printf) { 2556 printf("\nSyncing disks, vnodes remaining... "); 2557 first_printf = 0; 2558 } 2559 printf("%d ", net_worklist_len); 2560 } 2561 starttime = time_uptime; 2562 2563 /* 2564 * Push files whose dirty time has expired. Be careful 2565 * of interrupt race on slp queue. 2566 * 2567 * Skip over empty worklist slots when shutting down. 2568 */ 2569 do { 2570 slp = &syncer_workitem_pending[syncer_delayno]; 2571 syncer_delayno += 1; 2572 if (syncer_delayno == syncer_maxdelay) 2573 syncer_delayno = 0; 2574 next = &syncer_workitem_pending[syncer_delayno]; 2575 /* 2576 * If the worklist has wrapped since the 2577 * it was emptied of all but syncer vnodes, 2578 * switch to the FINAL_DELAY state and run 2579 * for one more second. 2580 */ 2581 if (syncer_state == SYNCER_SHUTTING_DOWN && 2582 net_worklist_len == 0 && 2583 last_work_seen == syncer_delayno) { 2584 syncer_state = SYNCER_FINAL_DELAY; 2585 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2586 } 2587 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2588 syncer_worklist_len > 0); 2589 2590 /* 2591 * Keep track of the last time there was anything 2592 * on the worklist other than syncer vnodes. 2593 * Return to the SHUTTING_DOWN state if any 2594 * new work appears. 2595 */ 2596 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2597 last_work_seen = syncer_delayno; 2598 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2599 syncer_state = SYNCER_SHUTTING_DOWN; 2600 while (!LIST_EMPTY(slp)) { 2601 error = sync_vnode(slp, &bo, td); 2602 if (error == 1) { 2603 LIST_REMOVE(bo, bo_synclist); 2604 LIST_INSERT_HEAD(next, bo, bo_synclist); 2605 continue; 2606 } 2607 2608 if (first_printf == 0) { 2609 /* 2610 * Drop the sync mutex, because some watchdog 2611 * drivers need to sleep while patting 2612 */ 2613 mtx_unlock(&sync_mtx); 2614 wdog_kern_pat(WD_LASTVAL); 2615 mtx_lock(&sync_mtx); 2616 } 2617 2618 } 2619 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2620 syncer_final_iter--; 2621 /* 2622 * The variable rushjob allows the kernel to speed up the 2623 * processing of the filesystem syncer process. A rushjob 2624 * value of N tells the filesystem syncer to process the next 2625 * N seconds worth of work on its queue ASAP. Currently rushjob 2626 * is used by the soft update code to speed up the filesystem 2627 * syncer process when the incore state is getting so far 2628 * ahead of the disk that the kernel memory pool is being 2629 * threatened with exhaustion. 2630 */ 2631 if (rushjob > 0) { 2632 rushjob -= 1; 2633 continue; 2634 } 2635 /* 2636 * Just sleep for a short period of time between 2637 * iterations when shutting down to allow some I/O 2638 * to happen. 2639 * 2640 * If it has taken us less than a second to process the 2641 * current work, then wait. Otherwise start right over 2642 * again. We can still lose time if any single round 2643 * takes more than two seconds, but it does not really 2644 * matter as we are just trying to generally pace the 2645 * filesystem activity. 2646 */ 2647 if (syncer_state != SYNCER_RUNNING || 2648 time_uptime == starttime) { 2649 thread_lock(td); 2650 sched_prio(td, PPAUSE); 2651 thread_unlock(td); 2652 } 2653 if (syncer_state != SYNCER_RUNNING) 2654 cv_timedwait(&sync_wakeup, &sync_mtx, 2655 hz / SYNCER_SHUTDOWN_SPEEDUP); 2656 else if (time_uptime == starttime) 2657 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2658 } 2659 } 2660 2661 /* 2662 * Request the syncer daemon to speed up its work. 2663 * We never push it to speed up more than half of its 2664 * normal turn time, otherwise it could take over the cpu. 2665 */ 2666 int 2667 speedup_syncer(void) 2668 { 2669 int ret = 0; 2670 2671 mtx_lock(&sync_mtx); 2672 if (rushjob < syncdelay / 2) { 2673 rushjob += 1; 2674 stat_rush_requests += 1; 2675 ret = 1; 2676 } 2677 mtx_unlock(&sync_mtx); 2678 cv_broadcast(&sync_wakeup); 2679 return (ret); 2680 } 2681 2682 /* 2683 * Tell the syncer to speed up its work and run though its work 2684 * list several times, then tell it to shut down. 2685 */ 2686 static void 2687 syncer_shutdown(void *arg, int howto) 2688 { 2689 2690 if (howto & RB_NOSYNC) 2691 return; 2692 mtx_lock(&sync_mtx); 2693 syncer_state = SYNCER_SHUTTING_DOWN; 2694 rushjob = 0; 2695 mtx_unlock(&sync_mtx); 2696 cv_broadcast(&sync_wakeup); 2697 kproc_shutdown(arg, howto); 2698 } 2699 2700 void 2701 syncer_suspend(void) 2702 { 2703 2704 syncer_shutdown(updateproc, 0); 2705 } 2706 2707 void 2708 syncer_resume(void) 2709 { 2710 2711 mtx_lock(&sync_mtx); 2712 first_printf = 1; 2713 syncer_state = SYNCER_RUNNING; 2714 mtx_unlock(&sync_mtx); 2715 cv_broadcast(&sync_wakeup); 2716 kproc_resume(updateproc); 2717 } 2718 2719 /* 2720 * Reassign a buffer from one vnode to another. 2721 * Used to assign file specific control information 2722 * (indirect blocks) to the vnode to which they belong. 2723 */ 2724 void 2725 reassignbuf(struct buf *bp) 2726 { 2727 struct vnode *vp; 2728 struct bufobj *bo; 2729 int delay; 2730 #ifdef INVARIANTS 2731 struct bufv *bv; 2732 #endif 2733 2734 vp = bp->b_vp; 2735 bo = bp->b_bufobj; 2736 ++reassignbufcalls; 2737 2738 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2739 bp, bp->b_vp, bp->b_flags); 2740 /* 2741 * B_PAGING flagged buffers cannot be reassigned because their vp 2742 * is not fully linked in. 2743 */ 2744 if (bp->b_flags & B_PAGING) 2745 panic("cannot reassign paging buffer"); 2746 2747 /* 2748 * Delete from old vnode list, if on one. 2749 */ 2750 BO_LOCK(bo); 2751 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2752 buf_vlist_remove(bp); 2753 else 2754 panic("reassignbuf: Buffer %p not on queue.", bp); 2755 /* 2756 * If dirty, put on list of dirty buffers; otherwise insert onto list 2757 * of clean buffers. 2758 */ 2759 if (bp->b_flags & B_DELWRI) { 2760 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2761 switch (vp->v_type) { 2762 case VDIR: 2763 delay = dirdelay; 2764 break; 2765 case VCHR: 2766 delay = metadelay; 2767 break; 2768 default: 2769 delay = filedelay; 2770 } 2771 vn_syncer_add_to_worklist(bo, delay); 2772 } 2773 buf_vlist_add(bp, bo, BX_VNDIRTY); 2774 } else { 2775 buf_vlist_add(bp, bo, BX_VNCLEAN); 2776 2777 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2778 mtx_lock(&sync_mtx); 2779 LIST_REMOVE(bo, bo_synclist); 2780 syncer_worklist_len--; 2781 mtx_unlock(&sync_mtx); 2782 bo->bo_flag &= ~BO_ONWORKLST; 2783 } 2784 } 2785 #ifdef INVARIANTS 2786 bv = &bo->bo_clean; 2787 bp = TAILQ_FIRST(&bv->bv_hd); 2788 KASSERT(bp == NULL || bp->b_bufobj == bo, 2789 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2790 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2791 KASSERT(bp == NULL || bp->b_bufobj == bo, 2792 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2793 bv = &bo->bo_dirty; 2794 bp = TAILQ_FIRST(&bv->bv_hd); 2795 KASSERT(bp == NULL || bp->b_bufobj == bo, 2796 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2797 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2798 KASSERT(bp == NULL || bp->b_bufobj == bo, 2799 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2800 #endif 2801 BO_UNLOCK(bo); 2802 } 2803 2804 static void 2805 v_init_counters(struct vnode *vp) 2806 { 2807 2808 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2809 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2810 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2811 2812 refcount_init(&vp->v_holdcnt, 1); 2813 refcount_init(&vp->v_usecount, 1); 2814 } 2815 2816 /* 2817 * Increment si_usecount of the associated device, if any. 2818 */ 2819 static void 2820 v_incr_devcount(struct vnode *vp) 2821 { 2822 2823 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2824 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2825 dev_lock(); 2826 vp->v_rdev->si_usecount++; 2827 dev_unlock(); 2828 } 2829 } 2830 2831 /* 2832 * Decrement si_usecount of the associated device, if any. 2833 * 2834 * The caller is required to hold the interlock when transitioning a VCHR use 2835 * count to zero. This prevents a race with devfs_reclaim_vchr() that would 2836 * leak a si_usecount reference. The vnode lock will also prevent this race 2837 * if it is held while dropping the last ref. 2838 * 2839 * The race is: 2840 * 2841 * CPU1 CPU2 2842 * devfs_reclaim_vchr 2843 * make v_usecount == 0 2844 * VI_LOCK 2845 * sees v_usecount == 0, no updates 2846 * vp->v_rdev = NULL; 2847 * ... 2848 * VI_UNLOCK 2849 * VI_LOCK 2850 * v_decr_devcount 2851 * sees v_rdev == NULL, no updates 2852 * 2853 * In this scenario si_devcount decrement is not performed. 2854 */ 2855 static void 2856 v_decr_devcount(struct vnode *vp) 2857 { 2858 2859 ASSERT_VOP_LOCKED(vp, __func__); 2860 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2861 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2862 dev_lock(); 2863 VNPASS(vp->v_rdev->si_usecount > 0, vp); 2864 vp->v_rdev->si_usecount--; 2865 dev_unlock(); 2866 } 2867 } 2868 2869 /* 2870 * Grab a particular vnode from the free list, increment its 2871 * reference count and lock it. VIRF_DOOMED is set if the vnode 2872 * is being destroyed. Only callers who specify LK_RETRY will 2873 * see doomed vnodes. If inactive processing was delayed in 2874 * vput try to do it here. 2875 * 2876 * usecount is manipulated using atomics without holding any locks. 2877 * 2878 * holdcnt can be manipulated using atomics without holding any locks, 2879 * except when transitioning 1<->0, in which case the interlock is held. 2880 * 2881 * Consumers which don't guarantee liveness of the vnode can use SMR to 2882 * try to get a reference. Note this operation can fail since the vnode 2883 * may be awaiting getting freed by the time they get to it. 2884 */ 2885 enum vgetstate 2886 vget_prep_smr(struct vnode *vp) 2887 { 2888 enum vgetstate vs; 2889 2890 VFS_SMR_ASSERT_ENTERED(); 2891 2892 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2893 vs = VGET_USECOUNT; 2894 } else { 2895 if (vhold_smr(vp)) 2896 vs = VGET_HOLDCNT; 2897 else 2898 vs = VGET_NONE; 2899 } 2900 return (vs); 2901 } 2902 2903 enum vgetstate 2904 vget_prep(struct vnode *vp) 2905 { 2906 enum vgetstate vs; 2907 2908 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2909 vs = VGET_USECOUNT; 2910 } else { 2911 vhold(vp); 2912 vs = VGET_HOLDCNT; 2913 } 2914 return (vs); 2915 } 2916 2917 void 2918 vget_abort(struct vnode *vp, enum vgetstate vs) 2919 { 2920 2921 switch (vs) { 2922 case VGET_USECOUNT: 2923 vrele(vp); 2924 break; 2925 case VGET_HOLDCNT: 2926 vdrop(vp); 2927 break; 2928 default: 2929 __assert_unreachable(); 2930 } 2931 } 2932 2933 int 2934 vget(struct vnode *vp, int flags, struct thread *td) 2935 { 2936 enum vgetstate vs; 2937 2938 MPASS(td == curthread); 2939 2940 vs = vget_prep(vp); 2941 return (vget_finish(vp, flags, vs)); 2942 } 2943 2944 static void __noinline 2945 vget_finish_vchr(struct vnode *vp) 2946 { 2947 2948 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 2949 2950 /* 2951 * See the comment in vget_finish before usecount bump. 2952 */ 2953 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2954 #ifdef INVARIANTS 2955 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2956 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 2957 #else 2958 refcount_release(&vp->v_holdcnt); 2959 #endif 2960 return; 2961 } 2962 2963 VI_LOCK(vp); 2964 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2965 #ifdef INVARIANTS 2966 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2967 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2968 #else 2969 refcount_release(&vp->v_holdcnt); 2970 #endif 2971 VI_UNLOCK(vp); 2972 return; 2973 } 2974 v_incr_devcount(vp); 2975 refcount_acquire(&vp->v_usecount); 2976 VI_UNLOCK(vp); 2977 } 2978 2979 int 2980 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2981 { 2982 int error; 2983 2984 if ((flags & LK_INTERLOCK) != 0) 2985 ASSERT_VI_LOCKED(vp, __func__); 2986 else 2987 ASSERT_VI_UNLOCKED(vp, __func__); 2988 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 2989 VNPASS(vp->v_holdcnt > 0, vp); 2990 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2991 2992 error = vn_lock(vp, flags); 2993 if (__predict_false(error != 0)) { 2994 vget_abort(vp, vs); 2995 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2996 vp); 2997 return (error); 2998 } 2999 3000 vget_finish_ref(vp, vs); 3001 return (0); 3002 } 3003 3004 void 3005 vget_finish_ref(struct vnode *vp, enum vgetstate vs) 3006 { 3007 int old; 3008 3009 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 3010 VNPASS(vp->v_holdcnt > 0, vp); 3011 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 3012 3013 if (vs == VGET_USECOUNT) 3014 return; 3015 3016 if (__predict_false(vp->v_type == VCHR)) { 3017 vget_finish_vchr(vp); 3018 return; 3019 } 3020 3021 /* 3022 * We hold the vnode. If the usecount is 0 it will be utilized to keep 3023 * the vnode around. Otherwise someone else lended their hold count and 3024 * we have to drop ours. 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 /* 3039 * Increase the reference (use) and hold count of a vnode. 3040 * This will also remove the vnode from the free list if it is presently free. 3041 */ 3042 static void __noinline 3043 vref_vchr(struct vnode *vp, bool interlock) 3044 { 3045 3046 /* 3047 * See the comment in vget_finish before usecount bump. 3048 */ 3049 if (!interlock) { 3050 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3051 VNODE_REFCOUNT_FENCE_ACQ(); 3052 VNASSERT(vp->v_holdcnt > 0, vp, 3053 ("%s: active vnode not held", __func__)); 3054 return; 3055 } 3056 VI_LOCK(vp); 3057 /* 3058 * By the time we get here the vnode might have been doomed, at 3059 * which point the 0->1 use count transition is no longer 3060 * protected by the interlock. Since it can't bounce back to 3061 * VCHR and requires vref semantics, punt it back 3062 */ 3063 if (__predict_false(vp->v_type == VBAD)) { 3064 VI_UNLOCK(vp); 3065 vref(vp); 3066 return; 3067 } 3068 } 3069 VNASSERT(vp->v_type == VCHR, vp, ("type != VCHR)")); 3070 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3071 VNODE_REFCOUNT_FENCE_ACQ(); 3072 VNASSERT(vp->v_holdcnt > 0, vp, 3073 ("%s: active vnode not held", __func__)); 3074 if (!interlock) 3075 VI_UNLOCK(vp); 3076 return; 3077 } 3078 vhold(vp); 3079 v_incr_devcount(vp); 3080 refcount_acquire(&vp->v_usecount); 3081 if (!interlock) 3082 VI_UNLOCK(vp); 3083 return; 3084 } 3085 3086 void 3087 vref(struct vnode *vp) 3088 { 3089 int old; 3090 3091 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3092 if (__predict_false(vp->v_type == VCHR)) { 3093 vref_vchr(vp, false); 3094 return; 3095 } 3096 3097 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3098 VNODE_REFCOUNT_FENCE_ACQ(); 3099 VNASSERT(vp->v_holdcnt > 0, vp, 3100 ("%s: active vnode not held", __func__)); 3101 return; 3102 } 3103 vhold(vp); 3104 /* 3105 * See the comment in vget_finish. 3106 */ 3107 old = atomic_fetchadd_int(&vp->v_usecount, 1); 3108 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 3109 if (old != 0) { 3110 #ifdef INVARIANTS 3111 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 3112 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 3113 #else 3114 refcount_release(&vp->v_holdcnt); 3115 #endif 3116 } 3117 } 3118 3119 void 3120 vrefl(struct vnode *vp) 3121 { 3122 3123 ASSERT_VI_LOCKED(vp, __func__); 3124 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3125 if (__predict_false(vp->v_type == VCHR)) { 3126 vref_vchr(vp, true); 3127 return; 3128 } 3129 vref(vp); 3130 } 3131 3132 void 3133 vrefact(struct vnode *vp) 3134 { 3135 3136 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3137 #ifdef INVARIANTS 3138 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 3139 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3140 #else 3141 refcount_acquire(&vp->v_usecount); 3142 #endif 3143 } 3144 3145 void 3146 vrefactn(struct vnode *vp, u_int n) 3147 { 3148 3149 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3150 #ifdef INVARIANTS 3151 int old = atomic_fetchadd_int(&vp->v_usecount, n); 3152 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3153 #else 3154 atomic_add_int(&vp->v_usecount, n); 3155 #endif 3156 } 3157 3158 /* 3159 * Return reference count of a vnode. 3160 * 3161 * The results of this call are only guaranteed when some mechanism is used to 3162 * stop other processes from gaining references to the vnode. This may be the 3163 * case if the caller holds the only reference. This is also useful when stale 3164 * data is acceptable as race conditions may be accounted for by some other 3165 * means. 3166 */ 3167 int 3168 vrefcnt(struct vnode *vp) 3169 { 3170 3171 return (vp->v_usecount); 3172 } 3173 3174 void 3175 vlazy(struct vnode *vp) 3176 { 3177 struct mount *mp; 3178 3179 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 3180 3181 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 3182 return; 3183 /* 3184 * We may get here for inactive routines after the vnode got doomed. 3185 */ 3186 if (VN_IS_DOOMED(vp)) 3187 return; 3188 mp = vp->v_mount; 3189 mtx_lock(&mp->mnt_listmtx); 3190 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 3191 vp->v_mflag |= VMP_LAZYLIST; 3192 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3193 mp->mnt_lazyvnodelistsize++; 3194 } 3195 mtx_unlock(&mp->mnt_listmtx); 3196 } 3197 3198 /* 3199 * This routine is only meant to be called from vgonel prior to dooming 3200 * the vnode. 3201 */ 3202 static void 3203 vunlazy_gone(struct vnode *vp) 3204 { 3205 struct mount *mp; 3206 3207 ASSERT_VOP_ELOCKED(vp, __func__); 3208 ASSERT_VI_LOCKED(vp, __func__); 3209 VNPASS(!VN_IS_DOOMED(vp), vp); 3210 3211 if (vp->v_mflag & VMP_LAZYLIST) { 3212 mp = vp->v_mount; 3213 mtx_lock(&mp->mnt_listmtx); 3214 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3215 vp->v_mflag &= ~VMP_LAZYLIST; 3216 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3217 mp->mnt_lazyvnodelistsize--; 3218 mtx_unlock(&mp->mnt_listmtx); 3219 } 3220 } 3221 3222 static void 3223 vdefer_inactive(struct vnode *vp) 3224 { 3225 3226 ASSERT_VI_LOCKED(vp, __func__); 3227 VNASSERT(vp->v_holdcnt > 0, vp, 3228 ("%s: vnode without hold count", __func__)); 3229 if (VN_IS_DOOMED(vp)) { 3230 vdropl(vp); 3231 return; 3232 } 3233 if (vp->v_iflag & VI_DEFINACT) { 3234 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3235 vdropl(vp); 3236 return; 3237 } 3238 if (vp->v_usecount > 0) { 3239 vp->v_iflag &= ~VI_OWEINACT; 3240 vdropl(vp); 3241 return; 3242 } 3243 vlazy(vp); 3244 vp->v_iflag |= VI_DEFINACT; 3245 VI_UNLOCK(vp); 3246 counter_u64_add(deferred_inact, 1); 3247 } 3248 3249 static void 3250 vdefer_inactive_unlocked(struct vnode *vp) 3251 { 3252 3253 VI_LOCK(vp); 3254 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3255 vdropl(vp); 3256 return; 3257 } 3258 vdefer_inactive(vp); 3259 } 3260 3261 enum vput_op { VRELE, VPUT, VUNREF }; 3262 3263 /* 3264 * Handle ->v_usecount transitioning to 0. 3265 * 3266 * By releasing the last usecount we take ownership of the hold count which 3267 * provides liveness of the vnode, meaning we have to vdrop. 3268 * 3269 * If the vnode is of type VCHR we may need to decrement si_usecount, see 3270 * v_decr_devcount for details. 3271 * 3272 * For all vnodes we may need to perform inactive processing. It requires an 3273 * exclusive lock on the vnode, while it is legal to call here with only a 3274 * shared lock (or no locks). If locking the vnode in an expected manner fails, 3275 * inactive processing gets deferred to the syncer. 3276 * 3277 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3278 * on the lock being held all the way until VOP_INACTIVE. This in particular 3279 * happens with UFS which adds half-constructed vnodes to the hash, where they 3280 * can be found by other code. 3281 */ 3282 static void 3283 vput_final(struct vnode *vp, enum vput_op func) 3284 { 3285 int error; 3286 bool want_unlock; 3287 3288 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3289 VNPASS(vp->v_holdcnt > 0, vp); 3290 3291 VI_LOCK(vp); 3292 if (__predict_false(vp->v_type == VCHR && func != VRELE)) 3293 v_decr_devcount(vp); 3294 3295 /* 3296 * By the time we got here someone else might have transitioned 3297 * the count back to > 0. 3298 */ 3299 if (vp->v_usecount > 0) 3300 goto out; 3301 3302 /* 3303 * If the vnode is doomed vgone already performed inactive processing 3304 * (if needed). 3305 */ 3306 if (VN_IS_DOOMED(vp)) 3307 goto out; 3308 3309 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0)) 3310 goto out; 3311 3312 if (vp->v_iflag & VI_DOINGINACT) 3313 goto out; 3314 3315 /* 3316 * Locking operations here will drop the interlock and possibly the 3317 * vnode lock, opening a window where the vnode can get doomed all the 3318 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to 3319 * perform inactive. 3320 */ 3321 vp->v_iflag |= VI_OWEINACT; 3322 want_unlock = false; 3323 error = 0; 3324 switch (func) { 3325 case VRELE: 3326 switch (VOP_ISLOCKED(vp)) { 3327 case LK_EXCLUSIVE: 3328 break; 3329 case LK_EXCLOTHER: 3330 case 0: 3331 want_unlock = true; 3332 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3333 VI_LOCK(vp); 3334 break; 3335 default: 3336 /* 3337 * The lock has at least one sharer, but we have no way 3338 * to conclude whether this is us. Play it safe and 3339 * defer processing. 3340 */ 3341 error = EAGAIN; 3342 break; 3343 } 3344 break; 3345 case VPUT: 3346 want_unlock = true; 3347 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3348 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3349 LK_NOWAIT); 3350 VI_LOCK(vp); 3351 } 3352 break; 3353 case VUNREF: 3354 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3355 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3356 VI_LOCK(vp); 3357 } 3358 break; 3359 } 3360 if (error == 0) { 3361 vinactive(vp); 3362 if (want_unlock) 3363 VOP_UNLOCK(vp); 3364 vdropl(vp); 3365 } else { 3366 vdefer_inactive(vp); 3367 } 3368 return; 3369 out: 3370 if (func == VPUT) 3371 VOP_UNLOCK(vp); 3372 vdropl(vp); 3373 } 3374 3375 /* 3376 * Decrement ->v_usecount for a vnode. 3377 * 3378 * Releasing the last use count requires additional processing, see vput_final 3379 * above for details. 3380 * 3381 * Note that releasing use count without the vnode lock requires special casing 3382 * for VCHR, see v_decr_devcount for details. 3383 * 3384 * Comment above each variant denotes lock state on entry and exit. 3385 */ 3386 3387 static void __noinline 3388 vrele_vchr(struct vnode *vp) 3389 { 3390 3391 if (refcount_release_if_not_last(&vp->v_usecount)) 3392 return; 3393 VI_LOCK(vp); 3394 if (!refcount_release(&vp->v_usecount)) { 3395 VI_UNLOCK(vp); 3396 return; 3397 } 3398 v_decr_devcount(vp); 3399 VI_UNLOCK(vp); 3400 vput_final(vp, VRELE); 3401 } 3402 3403 /* 3404 * in: any 3405 * out: same as passed in 3406 */ 3407 void 3408 vrele(struct vnode *vp) 3409 { 3410 3411 ASSERT_VI_UNLOCKED(vp, __func__); 3412 if (__predict_false(vp->v_type == VCHR)) { 3413 vrele_vchr(vp); 3414 return; 3415 } 3416 if (!refcount_release(&vp->v_usecount)) 3417 return; 3418 vput_final(vp, VRELE); 3419 } 3420 3421 /* 3422 * in: locked 3423 * out: unlocked 3424 */ 3425 void 3426 vput(struct vnode *vp) 3427 { 3428 3429 ASSERT_VOP_LOCKED(vp, __func__); 3430 ASSERT_VI_UNLOCKED(vp, __func__); 3431 if (!refcount_release(&vp->v_usecount)) { 3432 VOP_UNLOCK(vp); 3433 return; 3434 } 3435 vput_final(vp, VPUT); 3436 } 3437 3438 /* 3439 * in: locked 3440 * out: locked 3441 */ 3442 void 3443 vunref(struct vnode *vp) 3444 { 3445 3446 ASSERT_VOP_LOCKED(vp, __func__); 3447 ASSERT_VI_UNLOCKED(vp, __func__); 3448 if (!refcount_release(&vp->v_usecount)) 3449 return; 3450 vput_final(vp, VUNREF); 3451 } 3452 3453 void 3454 vhold(struct vnode *vp) 3455 { 3456 struct vdbatch *vd; 3457 int old; 3458 3459 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3460 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3461 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3462 ("%s: wrong hold count %d", __func__, old)); 3463 if (old != 0) 3464 return; 3465 critical_enter(); 3466 vd = DPCPU_PTR(vd); 3467 vd->freevnodes--; 3468 critical_exit(); 3469 } 3470 3471 void 3472 vholdl(struct vnode *vp) 3473 { 3474 3475 ASSERT_VI_LOCKED(vp, __func__); 3476 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3477 vhold(vp); 3478 } 3479 3480 void 3481 vholdnz(struct vnode *vp) 3482 { 3483 3484 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3485 #ifdef INVARIANTS 3486 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3487 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3488 ("%s: wrong hold count %d", __func__, old)); 3489 #else 3490 atomic_add_int(&vp->v_holdcnt, 1); 3491 #endif 3492 } 3493 3494 /* 3495 * Grab a hold count unless the vnode is freed. 3496 * 3497 * Only use this routine if vfs smr is the only protection you have against 3498 * freeing the vnode. 3499 * 3500 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag 3501 * is not set. After the flag is set the vnode becomes immutable to anyone but 3502 * the thread which managed to set the flag. 3503 * 3504 * It may be tempting to replace the loop with: 3505 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3506 * if (count & VHOLD_NO_SMR) { 3507 * backpedal and error out; 3508 * } 3509 * 3510 * However, while this is more performant, it hinders debugging by eliminating 3511 * the previously mentioned invariant. 3512 */ 3513 bool 3514 vhold_smr(struct vnode *vp) 3515 { 3516 int count; 3517 3518 VFS_SMR_ASSERT_ENTERED(); 3519 3520 count = atomic_load_int(&vp->v_holdcnt); 3521 for (;;) { 3522 if (count & VHOLD_NO_SMR) { 3523 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3524 ("non-zero hold count with flags %d\n", count)); 3525 return (false); 3526 } 3527 3528 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3529 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) 3530 return (true); 3531 } 3532 } 3533 3534 static void __noinline 3535 vdbatch_process(struct vdbatch *vd) 3536 { 3537 struct vnode *vp; 3538 int i; 3539 3540 mtx_assert(&vd->lock, MA_OWNED); 3541 MPASS(curthread->td_pinned > 0); 3542 MPASS(vd->index == VDBATCH_SIZE); 3543 3544 mtx_lock(&vnode_list_mtx); 3545 critical_enter(); 3546 freevnodes += vd->freevnodes; 3547 for (i = 0; i < VDBATCH_SIZE; i++) { 3548 vp = vd->tab[i]; 3549 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3550 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3551 MPASS(vp->v_dbatchcpu != NOCPU); 3552 vp->v_dbatchcpu = NOCPU; 3553 } 3554 mtx_unlock(&vnode_list_mtx); 3555 vd->freevnodes = 0; 3556 bzero(vd->tab, sizeof(vd->tab)); 3557 vd->index = 0; 3558 critical_exit(); 3559 } 3560 3561 static void 3562 vdbatch_enqueue(struct vnode *vp) 3563 { 3564 struct vdbatch *vd; 3565 3566 ASSERT_VI_LOCKED(vp, __func__); 3567 VNASSERT(!VN_IS_DOOMED(vp), vp, 3568 ("%s: deferring requeue of a doomed vnode", __func__)); 3569 3570 critical_enter(); 3571 vd = DPCPU_PTR(vd); 3572 vd->freevnodes++; 3573 if (vp->v_dbatchcpu != NOCPU) { 3574 VI_UNLOCK(vp); 3575 critical_exit(); 3576 return; 3577 } 3578 3579 sched_pin(); 3580 critical_exit(); 3581 mtx_lock(&vd->lock); 3582 MPASS(vd->index < VDBATCH_SIZE); 3583 MPASS(vd->tab[vd->index] == NULL); 3584 /* 3585 * A hack: we depend on being pinned so that we know what to put in 3586 * ->v_dbatchcpu. 3587 */ 3588 vp->v_dbatchcpu = curcpu; 3589 vd->tab[vd->index] = vp; 3590 vd->index++; 3591 VI_UNLOCK(vp); 3592 if (vd->index == VDBATCH_SIZE) 3593 vdbatch_process(vd); 3594 mtx_unlock(&vd->lock); 3595 sched_unpin(); 3596 } 3597 3598 /* 3599 * This routine must only be called for vnodes which are about to be 3600 * deallocated. Supporting dequeue for arbitrary vndoes would require 3601 * validating that the locked batch matches. 3602 */ 3603 static void 3604 vdbatch_dequeue(struct vnode *vp) 3605 { 3606 struct vdbatch *vd; 3607 int i; 3608 short cpu; 3609 3610 VNASSERT(vp->v_type == VBAD || vp->v_type == VNON, vp, 3611 ("%s: called for a used vnode\n", __func__)); 3612 3613 cpu = vp->v_dbatchcpu; 3614 if (cpu == NOCPU) 3615 return; 3616 3617 vd = DPCPU_ID_PTR(cpu, vd); 3618 mtx_lock(&vd->lock); 3619 for (i = 0; i < vd->index; i++) { 3620 if (vd->tab[i] != vp) 3621 continue; 3622 vp->v_dbatchcpu = NOCPU; 3623 vd->index--; 3624 vd->tab[i] = vd->tab[vd->index]; 3625 vd->tab[vd->index] = NULL; 3626 break; 3627 } 3628 mtx_unlock(&vd->lock); 3629 /* 3630 * Either we dequeued the vnode above or the target CPU beat us to it. 3631 */ 3632 MPASS(vp->v_dbatchcpu == NOCPU); 3633 } 3634 3635 /* 3636 * Drop the hold count of the vnode. If this is the last reference to 3637 * the vnode we place it on the free list unless it has been vgone'd 3638 * (marked VIRF_DOOMED) in which case we will free it. 3639 * 3640 * Because the vnode vm object keeps a hold reference on the vnode if 3641 * there is at least one resident non-cached page, the vnode cannot 3642 * leave the active list without the page cleanup done. 3643 */ 3644 static void 3645 vdrop_deactivate(struct vnode *vp) 3646 { 3647 struct mount *mp; 3648 3649 ASSERT_VI_LOCKED(vp, __func__); 3650 /* 3651 * Mark a vnode as free: remove it from its active list 3652 * and put it up for recycling on the freelist. 3653 */ 3654 VNASSERT(!VN_IS_DOOMED(vp), vp, 3655 ("vdrop: returning doomed vnode")); 3656 VNASSERT(vp->v_op != NULL, vp, 3657 ("vdrop: vnode already reclaimed.")); 3658 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 3659 ("vnode with VI_OWEINACT set")); 3660 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, 3661 ("vnode with VI_DEFINACT set")); 3662 if (vp->v_mflag & VMP_LAZYLIST) { 3663 mp = vp->v_mount; 3664 mtx_lock(&mp->mnt_listmtx); 3665 VNASSERT(vp->v_mflag & VMP_LAZYLIST, vp, ("lost VMP_LAZYLIST")); 3666 /* 3667 * Don't remove the vnode from the lazy list if another thread 3668 * has increased the hold count. It may have re-enqueued the 3669 * vnode to the lazy list and is now responsible for its 3670 * removal. 3671 */ 3672 if (vp->v_holdcnt == 0) { 3673 vp->v_mflag &= ~VMP_LAZYLIST; 3674 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3675 mp->mnt_lazyvnodelistsize--; 3676 } 3677 mtx_unlock(&mp->mnt_listmtx); 3678 } 3679 vdbatch_enqueue(vp); 3680 } 3681 3682 void 3683 vdrop(struct vnode *vp) 3684 { 3685 3686 ASSERT_VI_UNLOCKED(vp, __func__); 3687 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3688 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3689 return; 3690 VI_LOCK(vp); 3691 vdropl(vp); 3692 } 3693 3694 void 3695 vdropl(struct vnode *vp) 3696 { 3697 3698 ASSERT_VI_LOCKED(vp, __func__); 3699 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3700 if (!refcount_release(&vp->v_holdcnt)) { 3701 VI_UNLOCK(vp); 3702 return; 3703 } 3704 if (!VN_IS_DOOMED(vp)) { 3705 vdrop_deactivate(vp); 3706 return; 3707 } 3708 /* 3709 * We may be racing against vhold_smr. 3710 * 3711 * If they win we can just pretend we never got this far, they will 3712 * vdrop later. 3713 */ 3714 if (!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR)) { 3715 /* 3716 * We lost the aforementioned race. Note that any subsequent 3717 * access is invalid as they might have managed to vdropl on 3718 * their own. 3719 */ 3720 return; 3721 } 3722 freevnode(vp); 3723 } 3724 3725 /* 3726 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3727 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3728 */ 3729 static void 3730 vinactivef(struct vnode *vp) 3731 { 3732 struct vm_object *obj; 3733 3734 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3735 ASSERT_VI_LOCKED(vp, "vinactive"); 3736 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3737 ("vinactive: recursed on VI_DOINGINACT")); 3738 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3739 vp->v_iflag |= VI_DOINGINACT; 3740 vp->v_iflag &= ~VI_OWEINACT; 3741 VI_UNLOCK(vp); 3742 /* 3743 * Before moving off the active list, we must be sure that any 3744 * modified pages are converted into the vnode's dirty 3745 * buffers, since these will no longer be checked once the 3746 * vnode is on the inactive list. 3747 * 3748 * The write-out of the dirty pages is asynchronous. At the 3749 * point that VOP_INACTIVE() is called, there could still be 3750 * pending I/O and dirty pages in the object. 3751 */ 3752 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3753 vm_object_mightbedirty(obj)) { 3754 VM_OBJECT_WLOCK(obj); 3755 vm_object_page_clean(obj, 0, 0, 0); 3756 VM_OBJECT_WUNLOCK(obj); 3757 } 3758 VOP_INACTIVE(vp, curthread); 3759 VI_LOCK(vp); 3760 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3761 ("vinactive: lost VI_DOINGINACT")); 3762 vp->v_iflag &= ~VI_DOINGINACT; 3763 } 3764 3765 void 3766 vinactive(struct vnode *vp) 3767 { 3768 3769 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3770 ASSERT_VI_LOCKED(vp, "vinactive"); 3771 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3772 3773 if ((vp->v_iflag & VI_OWEINACT) == 0) 3774 return; 3775 if (vp->v_iflag & VI_DOINGINACT) 3776 return; 3777 if (vp->v_usecount > 0) { 3778 vp->v_iflag &= ~VI_OWEINACT; 3779 return; 3780 } 3781 vinactivef(vp); 3782 } 3783 3784 /* 3785 * Remove any vnodes in the vnode table belonging to mount point mp. 3786 * 3787 * If FORCECLOSE is not specified, there should not be any active ones, 3788 * return error if any are found (nb: this is a user error, not a 3789 * system error). If FORCECLOSE is specified, detach any active vnodes 3790 * that are found. 3791 * 3792 * If WRITECLOSE is set, only flush out regular file vnodes open for 3793 * writing. 3794 * 3795 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3796 * 3797 * `rootrefs' specifies the base reference count for the root vnode 3798 * of this filesystem. The root vnode is considered busy if its 3799 * v_usecount exceeds this value. On a successful return, vflush(, td) 3800 * will call vrele() on the root vnode exactly rootrefs times. 3801 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3802 * be zero. 3803 */ 3804 #ifdef DIAGNOSTIC 3805 static int busyprt = 0; /* print out busy vnodes */ 3806 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3807 #endif 3808 3809 int 3810 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3811 { 3812 struct vnode *vp, *mvp, *rootvp = NULL; 3813 struct vattr vattr; 3814 int busy = 0, error; 3815 3816 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3817 rootrefs, flags); 3818 if (rootrefs > 0) { 3819 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3820 ("vflush: bad args")); 3821 /* 3822 * Get the filesystem root vnode. We can vput() it 3823 * immediately, since with rootrefs > 0, it won't go away. 3824 */ 3825 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3826 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3827 __func__, error); 3828 return (error); 3829 } 3830 vput(rootvp); 3831 } 3832 loop: 3833 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3834 vholdl(vp); 3835 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3836 if (error) { 3837 vdrop(vp); 3838 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3839 goto loop; 3840 } 3841 /* 3842 * Skip over a vnodes marked VV_SYSTEM. 3843 */ 3844 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3845 VOP_UNLOCK(vp); 3846 vdrop(vp); 3847 continue; 3848 } 3849 /* 3850 * If WRITECLOSE is set, flush out unlinked but still open 3851 * files (even if open only for reading) and regular file 3852 * vnodes open for writing. 3853 */ 3854 if (flags & WRITECLOSE) { 3855 if (vp->v_object != NULL) { 3856 VM_OBJECT_WLOCK(vp->v_object); 3857 vm_object_page_clean(vp->v_object, 0, 0, 0); 3858 VM_OBJECT_WUNLOCK(vp->v_object); 3859 } 3860 error = VOP_FSYNC(vp, MNT_WAIT, td); 3861 if (error != 0) { 3862 VOP_UNLOCK(vp); 3863 vdrop(vp); 3864 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3865 return (error); 3866 } 3867 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3868 VI_LOCK(vp); 3869 3870 if ((vp->v_type == VNON || 3871 (error == 0 && vattr.va_nlink > 0)) && 3872 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3873 VOP_UNLOCK(vp); 3874 vdropl(vp); 3875 continue; 3876 } 3877 } else 3878 VI_LOCK(vp); 3879 /* 3880 * With v_usecount == 0, all we need to do is clear out the 3881 * vnode data structures and we are done. 3882 * 3883 * If FORCECLOSE is set, forcibly close the vnode. 3884 */ 3885 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3886 vgonel(vp); 3887 } else { 3888 busy++; 3889 #ifdef DIAGNOSTIC 3890 if (busyprt) 3891 vn_printf(vp, "vflush: busy vnode "); 3892 #endif 3893 } 3894 VOP_UNLOCK(vp); 3895 vdropl(vp); 3896 } 3897 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3898 /* 3899 * If just the root vnode is busy, and if its refcount 3900 * is equal to `rootrefs', then go ahead and kill it. 3901 */ 3902 VI_LOCK(rootvp); 3903 KASSERT(busy > 0, ("vflush: not busy")); 3904 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3905 ("vflush: usecount %d < rootrefs %d", 3906 rootvp->v_usecount, rootrefs)); 3907 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3908 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3909 vgone(rootvp); 3910 VOP_UNLOCK(rootvp); 3911 busy = 0; 3912 } else 3913 VI_UNLOCK(rootvp); 3914 } 3915 if (busy) { 3916 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3917 busy); 3918 return (EBUSY); 3919 } 3920 for (; rootrefs > 0; rootrefs--) 3921 vrele(rootvp); 3922 return (0); 3923 } 3924 3925 /* 3926 * Recycle an unused vnode to the front of the free list. 3927 */ 3928 int 3929 vrecycle(struct vnode *vp) 3930 { 3931 int recycled; 3932 3933 VI_LOCK(vp); 3934 recycled = vrecyclel(vp); 3935 VI_UNLOCK(vp); 3936 return (recycled); 3937 } 3938 3939 /* 3940 * vrecycle, with the vp interlock held. 3941 */ 3942 int 3943 vrecyclel(struct vnode *vp) 3944 { 3945 int recycled; 3946 3947 ASSERT_VOP_ELOCKED(vp, __func__); 3948 ASSERT_VI_LOCKED(vp, __func__); 3949 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3950 recycled = 0; 3951 if (vp->v_usecount == 0) { 3952 recycled = 1; 3953 vgonel(vp); 3954 } 3955 return (recycled); 3956 } 3957 3958 /* 3959 * Eliminate all activity associated with a vnode 3960 * in preparation for reuse. 3961 */ 3962 void 3963 vgone(struct vnode *vp) 3964 { 3965 VI_LOCK(vp); 3966 vgonel(vp); 3967 VI_UNLOCK(vp); 3968 } 3969 3970 static void 3971 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3972 struct vnode *lowervp __unused) 3973 { 3974 } 3975 3976 /* 3977 * Notify upper mounts about reclaimed or unlinked vnode. 3978 */ 3979 void 3980 vfs_notify_upper(struct vnode *vp, int event) 3981 { 3982 static struct vfsops vgonel_vfsops = { 3983 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3984 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3985 }; 3986 struct mount *mp, *ump, *mmp; 3987 3988 mp = vp->v_mount; 3989 if (mp == NULL) 3990 return; 3991 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3992 return; 3993 3994 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3995 mmp->mnt_op = &vgonel_vfsops; 3996 mmp->mnt_kern_flag |= MNTK_MARKER; 3997 MNT_ILOCK(mp); 3998 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3999 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 4000 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 4001 ump = TAILQ_NEXT(ump, mnt_upper_link); 4002 continue; 4003 } 4004 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 4005 MNT_IUNLOCK(mp); 4006 switch (event) { 4007 case VFS_NOTIFY_UPPER_RECLAIM: 4008 VFS_RECLAIM_LOWERVP(ump, vp); 4009 break; 4010 case VFS_NOTIFY_UPPER_UNLINK: 4011 VFS_UNLINK_LOWERVP(ump, vp); 4012 break; 4013 default: 4014 KASSERT(0, ("invalid event %d", event)); 4015 break; 4016 } 4017 MNT_ILOCK(mp); 4018 ump = TAILQ_NEXT(mmp, mnt_upper_link); 4019 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 4020 } 4021 free(mmp, M_TEMP); 4022 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 4023 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 4024 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 4025 wakeup(&mp->mnt_uppers); 4026 } 4027 MNT_IUNLOCK(mp); 4028 } 4029 4030 /* 4031 * vgone, with the vp interlock held. 4032 */ 4033 static void 4034 vgonel(struct vnode *vp) 4035 { 4036 struct thread *td; 4037 struct mount *mp; 4038 vm_object_t object; 4039 bool active, oweinact; 4040 4041 ASSERT_VOP_ELOCKED(vp, "vgonel"); 4042 ASSERT_VI_LOCKED(vp, "vgonel"); 4043 VNASSERT(vp->v_holdcnt, vp, 4044 ("vgonel: vp %p has no reference.", vp)); 4045 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 4046 td = curthread; 4047 4048 /* 4049 * Don't vgonel if we're already doomed. 4050 */ 4051 if (vp->v_irflag & VIRF_DOOMED) 4052 return; 4053 /* 4054 * Paired with freevnode. 4055 */ 4056 vn_seqc_write_begin_locked(vp); 4057 vunlazy_gone(vp); 4058 vp->v_irflag |= VIRF_DOOMED; 4059 4060 /* 4061 * Check to see if the vnode is in use. If so, we have to call 4062 * VOP_CLOSE() and VOP_INACTIVE(). 4063 */ 4064 active = vp->v_usecount > 0; 4065 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 4066 /* 4067 * If we need to do inactive VI_OWEINACT will be set. 4068 */ 4069 if (vp->v_iflag & VI_DEFINACT) { 4070 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 4071 vp->v_iflag &= ~VI_DEFINACT; 4072 vdropl(vp); 4073 } else { 4074 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 4075 VI_UNLOCK(vp); 4076 } 4077 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 4078 4079 /* 4080 * If purging an active vnode, it must be closed and 4081 * deactivated before being reclaimed. 4082 */ 4083 if (active) 4084 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 4085 if (oweinact || active) { 4086 VI_LOCK(vp); 4087 vinactivef(vp); 4088 VI_UNLOCK(vp); 4089 } 4090 if (vp->v_type == VSOCK) 4091 vfs_unp_reclaim(vp); 4092 4093 /* 4094 * Clean out any buffers associated with the vnode. 4095 * If the flush fails, just toss the buffers. 4096 */ 4097 mp = NULL; 4098 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 4099 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 4100 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 4101 while (vinvalbuf(vp, 0, 0, 0) != 0) 4102 ; 4103 } 4104 4105 BO_LOCK(&vp->v_bufobj); 4106 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 4107 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 4108 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 4109 vp->v_bufobj.bo_clean.bv_cnt == 0, 4110 ("vp %p bufobj not invalidated", vp)); 4111 4112 /* 4113 * For VMIO bufobj, BO_DEAD is set later, or in 4114 * vm_object_terminate() after the object's page queue is 4115 * flushed. 4116 */ 4117 object = vp->v_bufobj.bo_object; 4118 if (object == NULL) 4119 vp->v_bufobj.bo_flag |= BO_DEAD; 4120 BO_UNLOCK(&vp->v_bufobj); 4121 4122 /* 4123 * Handle the VM part. Tmpfs handles v_object on its own (the 4124 * OBJT_VNODE check). Nullfs or other bypassing filesystems 4125 * should not touch the object borrowed from the lower vnode 4126 * (the handle check). 4127 */ 4128 if (object != NULL && object->type == OBJT_VNODE && 4129 object->handle == vp) 4130 vnode_destroy_vobject(vp); 4131 4132 /* 4133 * Reclaim the vnode. 4134 */ 4135 if (VOP_RECLAIM(vp, td)) 4136 panic("vgone: cannot reclaim"); 4137 if (mp != NULL) 4138 vn_finished_secondary_write(mp); 4139 VNASSERT(vp->v_object == NULL, vp, 4140 ("vop_reclaim left v_object vp=%p", vp)); 4141 /* 4142 * Clear the advisory locks and wake up waiting threads. 4143 */ 4144 (void)VOP_ADVLOCKPURGE(vp); 4145 vp->v_lockf = NULL; 4146 /* 4147 * Delete from old mount point vnode list. 4148 */ 4149 delmntque(vp); 4150 cache_purge(vp); 4151 /* 4152 * Done with purge, reset to the standard lock and invalidate 4153 * the vnode. 4154 */ 4155 VI_LOCK(vp); 4156 vp->v_vnlock = &vp->v_lock; 4157 vp->v_op = &dead_vnodeops; 4158 vp->v_type = VBAD; 4159 } 4160 4161 /* 4162 * Calculate the total number of references to a special device. 4163 */ 4164 int 4165 vcount(struct vnode *vp) 4166 { 4167 int count; 4168 4169 dev_lock(); 4170 count = vp->v_rdev->si_usecount; 4171 dev_unlock(); 4172 return (count); 4173 } 4174 4175 /* 4176 * Print out a description of a vnode. 4177 */ 4178 static const char * const typename[] = 4179 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 4180 "VMARKER"}; 4181 4182 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0, 4183 "new hold count flag not added to vn_printf"); 4184 4185 void 4186 vn_printf(struct vnode *vp, const char *fmt, ...) 4187 { 4188 va_list ap; 4189 char buf[256], buf2[16]; 4190 u_long flags; 4191 u_int holdcnt; 4192 4193 va_start(ap, fmt); 4194 vprintf(fmt, ap); 4195 va_end(ap); 4196 printf("%p: ", (void *)vp); 4197 printf("type %s\n", typename[vp->v_type]); 4198 holdcnt = atomic_load_int(&vp->v_holdcnt); 4199 printf(" usecount %d, writecount %d, refcount %d seqc users %d", 4200 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS, 4201 vp->v_seqc_users); 4202 switch (vp->v_type) { 4203 case VDIR: 4204 printf(" mountedhere %p\n", vp->v_mountedhere); 4205 break; 4206 case VCHR: 4207 printf(" rdev %p\n", vp->v_rdev); 4208 break; 4209 case VSOCK: 4210 printf(" socket %p\n", vp->v_unpcb); 4211 break; 4212 case VFIFO: 4213 printf(" fifoinfo %p\n", vp->v_fifoinfo); 4214 break; 4215 default: 4216 printf("\n"); 4217 break; 4218 } 4219 buf[0] = '\0'; 4220 buf[1] = '\0'; 4221 if (holdcnt & VHOLD_NO_SMR) 4222 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf)); 4223 printf(" hold count flags (%s)\n", buf + 1); 4224 4225 buf[0] = '\0'; 4226 buf[1] = '\0'; 4227 if (vp->v_irflag & VIRF_DOOMED) 4228 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 4229 flags = vp->v_irflag & ~(VIRF_DOOMED); 4230 if (flags != 0) { 4231 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 4232 strlcat(buf, buf2, sizeof(buf)); 4233 } 4234 if (vp->v_vflag & VV_ROOT) 4235 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4236 if (vp->v_vflag & VV_ISTTY) 4237 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4238 if (vp->v_vflag & VV_NOSYNC) 4239 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4240 if (vp->v_vflag & VV_ETERNALDEV) 4241 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4242 if (vp->v_vflag & VV_CACHEDLABEL) 4243 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4244 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4245 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4246 if (vp->v_vflag & VV_COPYONWRITE) 4247 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4248 if (vp->v_vflag & VV_SYSTEM) 4249 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4250 if (vp->v_vflag & VV_PROCDEP) 4251 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4252 if (vp->v_vflag & VV_NOKNOTE) 4253 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 4254 if (vp->v_vflag & VV_DELETED) 4255 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4256 if (vp->v_vflag & VV_MD) 4257 strlcat(buf, "|VV_MD", sizeof(buf)); 4258 if (vp->v_vflag & VV_FORCEINSMQ) 4259 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4260 if (vp->v_vflag & VV_READLINK) 4261 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4262 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4263 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 4264 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 4265 if (flags != 0) { 4266 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4267 strlcat(buf, buf2, sizeof(buf)); 4268 } 4269 if (vp->v_iflag & VI_TEXT_REF) 4270 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 4271 if (vp->v_iflag & VI_MOUNT) 4272 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4273 if (vp->v_iflag & VI_DOINGINACT) 4274 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4275 if (vp->v_iflag & VI_OWEINACT) 4276 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4277 if (vp->v_iflag & VI_DEFINACT) 4278 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4279 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | 4280 VI_OWEINACT | VI_DEFINACT); 4281 if (flags != 0) { 4282 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4283 strlcat(buf, buf2, sizeof(buf)); 4284 } 4285 if (vp->v_mflag & VMP_LAZYLIST) 4286 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4287 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4288 if (flags != 0) { 4289 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4290 strlcat(buf, buf2, sizeof(buf)); 4291 } 4292 printf(" flags (%s)\n", buf + 1); 4293 if (mtx_owned(VI_MTX(vp))) 4294 printf(" VI_LOCKed"); 4295 if (vp->v_object != NULL) 4296 printf(" v_object %p ref %d pages %d " 4297 "cleanbuf %d dirtybuf %d\n", 4298 vp->v_object, vp->v_object->ref_count, 4299 vp->v_object->resident_page_count, 4300 vp->v_bufobj.bo_clean.bv_cnt, 4301 vp->v_bufobj.bo_dirty.bv_cnt); 4302 printf(" "); 4303 lockmgr_printinfo(vp->v_vnlock); 4304 if (vp->v_data != NULL) 4305 VOP_PRINT(vp); 4306 } 4307 4308 #ifdef DDB 4309 /* 4310 * List all of the locked vnodes in the system. 4311 * Called when debugging the kernel. 4312 */ 4313 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 4314 { 4315 struct mount *mp; 4316 struct vnode *vp; 4317 4318 /* 4319 * Note: because this is DDB, we can't obey the locking semantics 4320 * for these structures, which means we could catch an inconsistent 4321 * state and dereference a nasty pointer. Not much to be done 4322 * about that. 4323 */ 4324 db_printf("Locked vnodes\n"); 4325 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4326 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4327 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4328 vn_printf(vp, "vnode "); 4329 } 4330 } 4331 } 4332 4333 /* 4334 * Show details about the given vnode. 4335 */ 4336 DB_SHOW_COMMAND(vnode, db_show_vnode) 4337 { 4338 struct vnode *vp; 4339 4340 if (!have_addr) 4341 return; 4342 vp = (struct vnode *)addr; 4343 vn_printf(vp, "vnode "); 4344 } 4345 4346 /* 4347 * Show details about the given mount point. 4348 */ 4349 DB_SHOW_COMMAND(mount, db_show_mount) 4350 { 4351 struct mount *mp; 4352 struct vfsopt *opt; 4353 struct statfs *sp; 4354 struct vnode *vp; 4355 char buf[512]; 4356 uint64_t mflags; 4357 u_int flags; 4358 4359 if (!have_addr) { 4360 /* No address given, print short info about all mount points. */ 4361 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4362 db_printf("%p %s on %s (%s)\n", mp, 4363 mp->mnt_stat.f_mntfromname, 4364 mp->mnt_stat.f_mntonname, 4365 mp->mnt_stat.f_fstypename); 4366 if (db_pager_quit) 4367 break; 4368 } 4369 db_printf("\nMore info: show mount <addr>\n"); 4370 return; 4371 } 4372 4373 mp = (struct mount *)addr; 4374 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4375 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4376 4377 buf[0] = '\0'; 4378 mflags = mp->mnt_flag; 4379 #define MNT_FLAG(flag) do { \ 4380 if (mflags & (flag)) { \ 4381 if (buf[0] != '\0') \ 4382 strlcat(buf, ", ", sizeof(buf)); \ 4383 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4384 mflags &= ~(flag); \ 4385 } \ 4386 } while (0) 4387 MNT_FLAG(MNT_RDONLY); 4388 MNT_FLAG(MNT_SYNCHRONOUS); 4389 MNT_FLAG(MNT_NOEXEC); 4390 MNT_FLAG(MNT_NOSUID); 4391 MNT_FLAG(MNT_NFS4ACLS); 4392 MNT_FLAG(MNT_UNION); 4393 MNT_FLAG(MNT_ASYNC); 4394 MNT_FLAG(MNT_SUIDDIR); 4395 MNT_FLAG(MNT_SOFTDEP); 4396 MNT_FLAG(MNT_NOSYMFOLLOW); 4397 MNT_FLAG(MNT_GJOURNAL); 4398 MNT_FLAG(MNT_MULTILABEL); 4399 MNT_FLAG(MNT_ACLS); 4400 MNT_FLAG(MNT_NOATIME); 4401 MNT_FLAG(MNT_NOCLUSTERR); 4402 MNT_FLAG(MNT_NOCLUSTERW); 4403 MNT_FLAG(MNT_SUJ); 4404 MNT_FLAG(MNT_EXRDONLY); 4405 MNT_FLAG(MNT_EXPORTED); 4406 MNT_FLAG(MNT_DEFEXPORTED); 4407 MNT_FLAG(MNT_EXPORTANON); 4408 MNT_FLAG(MNT_EXKERB); 4409 MNT_FLAG(MNT_EXPUBLIC); 4410 MNT_FLAG(MNT_LOCAL); 4411 MNT_FLAG(MNT_QUOTA); 4412 MNT_FLAG(MNT_ROOTFS); 4413 MNT_FLAG(MNT_USER); 4414 MNT_FLAG(MNT_IGNORE); 4415 MNT_FLAG(MNT_UPDATE); 4416 MNT_FLAG(MNT_DELEXPORT); 4417 MNT_FLAG(MNT_RELOAD); 4418 MNT_FLAG(MNT_FORCE); 4419 MNT_FLAG(MNT_SNAPSHOT); 4420 MNT_FLAG(MNT_BYFSID); 4421 #undef MNT_FLAG 4422 if (mflags != 0) { 4423 if (buf[0] != '\0') 4424 strlcat(buf, ", ", sizeof(buf)); 4425 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4426 "0x%016jx", mflags); 4427 } 4428 db_printf(" mnt_flag = %s\n", buf); 4429 4430 buf[0] = '\0'; 4431 flags = mp->mnt_kern_flag; 4432 #define MNT_KERN_FLAG(flag) do { \ 4433 if (flags & (flag)) { \ 4434 if (buf[0] != '\0') \ 4435 strlcat(buf, ", ", sizeof(buf)); \ 4436 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4437 flags &= ~(flag); \ 4438 } \ 4439 } while (0) 4440 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4441 MNT_KERN_FLAG(MNTK_ASYNC); 4442 MNT_KERN_FLAG(MNTK_SOFTDEP); 4443 MNT_KERN_FLAG(MNTK_DRAINING); 4444 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4445 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4446 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4447 MNT_KERN_FLAG(MNTK_NO_IOPF); 4448 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 4449 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 4450 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 4451 MNT_KERN_FLAG(MNTK_MARKER); 4452 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4453 MNT_KERN_FLAG(MNTK_FPLOOKUP); 4454 MNT_KERN_FLAG(MNTK_NOASYNC); 4455 MNT_KERN_FLAG(MNTK_UNMOUNT); 4456 MNT_KERN_FLAG(MNTK_MWAIT); 4457 MNT_KERN_FLAG(MNTK_SUSPEND); 4458 MNT_KERN_FLAG(MNTK_SUSPEND2); 4459 MNT_KERN_FLAG(MNTK_SUSPENDED); 4460 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4461 MNT_KERN_FLAG(MNTK_NOKNOTE); 4462 #undef MNT_KERN_FLAG 4463 if (flags != 0) { 4464 if (buf[0] != '\0') 4465 strlcat(buf, ", ", sizeof(buf)); 4466 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4467 "0x%08x", flags); 4468 } 4469 db_printf(" mnt_kern_flag = %s\n", buf); 4470 4471 db_printf(" mnt_opt = "); 4472 opt = TAILQ_FIRST(mp->mnt_opt); 4473 if (opt != NULL) { 4474 db_printf("%s", opt->name); 4475 opt = TAILQ_NEXT(opt, link); 4476 while (opt != NULL) { 4477 db_printf(", %s", opt->name); 4478 opt = TAILQ_NEXT(opt, link); 4479 } 4480 } 4481 db_printf("\n"); 4482 4483 sp = &mp->mnt_stat; 4484 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4485 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4486 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4487 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4488 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4489 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4490 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4491 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4492 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4493 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4494 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4495 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4496 4497 db_printf(" mnt_cred = { uid=%u ruid=%u", 4498 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4499 if (jailed(mp->mnt_cred)) 4500 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4501 db_printf(" }\n"); 4502 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4503 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4504 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4505 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4506 db_printf(" mnt_lazyvnodelistsize = %d\n", 4507 mp->mnt_lazyvnodelistsize); 4508 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4509 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4510 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4511 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4512 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4513 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4514 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4515 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4516 db_printf(" mnt_secondary_accwrites = %d\n", 4517 mp->mnt_secondary_accwrites); 4518 db_printf(" mnt_gjprovider = %s\n", 4519 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4520 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4521 4522 db_printf("\n\nList of active vnodes\n"); 4523 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4524 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4525 vn_printf(vp, "vnode "); 4526 if (db_pager_quit) 4527 break; 4528 } 4529 } 4530 db_printf("\n\nList of inactive vnodes\n"); 4531 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4532 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4533 vn_printf(vp, "vnode "); 4534 if (db_pager_quit) 4535 break; 4536 } 4537 } 4538 } 4539 #endif /* DDB */ 4540 4541 /* 4542 * Fill in a struct xvfsconf based on a struct vfsconf. 4543 */ 4544 static int 4545 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4546 { 4547 struct xvfsconf xvfsp; 4548 4549 bzero(&xvfsp, sizeof(xvfsp)); 4550 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4551 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4552 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4553 xvfsp.vfc_flags = vfsp->vfc_flags; 4554 /* 4555 * These are unused in userland, we keep them 4556 * to not break binary compatibility. 4557 */ 4558 xvfsp.vfc_vfsops = NULL; 4559 xvfsp.vfc_next = NULL; 4560 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4561 } 4562 4563 #ifdef COMPAT_FREEBSD32 4564 struct xvfsconf32 { 4565 uint32_t vfc_vfsops; 4566 char vfc_name[MFSNAMELEN]; 4567 int32_t vfc_typenum; 4568 int32_t vfc_refcount; 4569 int32_t vfc_flags; 4570 uint32_t vfc_next; 4571 }; 4572 4573 static int 4574 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4575 { 4576 struct xvfsconf32 xvfsp; 4577 4578 bzero(&xvfsp, sizeof(xvfsp)); 4579 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4580 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4581 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4582 xvfsp.vfc_flags = vfsp->vfc_flags; 4583 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4584 } 4585 #endif 4586 4587 /* 4588 * Top level filesystem related information gathering. 4589 */ 4590 static int 4591 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4592 { 4593 struct vfsconf *vfsp; 4594 int error; 4595 4596 error = 0; 4597 vfsconf_slock(); 4598 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4599 #ifdef COMPAT_FREEBSD32 4600 if (req->flags & SCTL_MASK32) 4601 error = vfsconf2x32(req, vfsp); 4602 else 4603 #endif 4604 error = vfsconf2x(req, vfsp); 4605 if (error) 4606 break; 4607 } 4608 vfsconf_sunlock(); 4609 return (error); 4610 } 4611 4612 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4613 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4614 "S,xvfsconf", "List of all configured filesystems"); 4615 4616 #ifndef BURN_BRIDGES 4617 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4618 4619 static int 4620 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4621 { 4622 int *name = (int *)arg1 - 1; /* XXX */ 4623 u_int namelen = arg2 + 1; /* XXX */ 4624 struct vfsconf *vfsp; 4625 4626 log(LOG_WARNING, "userland calling deprecated sysctl, " 4627 "please rebuild world\n"); 4628 4629 #if 1 || defined(COMPAT_PRELITE2) 4630 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4631 if (namelen == 1) 4632 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4633 #endif 4634 4635 switch (name[1]) { 4636 case VFS_MAXTYPENUM: 4637 if (namelen != 2) 4638 return (ENOTDIR); 4639 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4640 case VFS_CONF: 4641 if (namelen != 3) 4642 return (ENOTDIR); /* overloaded */ 4643 vfsconf_slock(); 4644 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4645 if (vfsp->vfc_typenum == name[2]) 4646 break; 4647 } 4648 vfsconf_sunlock(); 4649 if (vfsp == NULL) 4650 return (EOPNOTSUPP); 4651 #ifdef COMPAT_FREEBSD32 4652 if (req->flags & SCTL_MASK32) 4653 return (vfsconf2x32(req, vfsp)); 4654 else 4655 #endif 4656 return (vfsconf2x(req, vfsp)); 4657 } 4658 return (EOPNOTSUPP); 4659 } 4660 4661 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4662 CTLFLAG_MPSAFE, vfs_sysctl, 4663 "Generic filesystem"); 4664 4665 #if 1 || defined(COMPAT_PRELITE2) 4666 4667 static int 4668 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4669 { 4670 int error; 4671 struct vfsconf *vfsp; 4672 struct ovfsconf ovfs; 4673 4674 vfsconf_slock(); 4675 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4676 bzero(&ovfs, sizeof(ovfs)); 4677 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4678 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4679 ovfs.vfc_index = vfsp->vfc_typenum; 4680 ovfs.vfc_refcount = vfsp->vfc_refcount; 4681 ovfs.vfc_flags = vfsp->vfc_flags; 4682 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4683 if (error != 0) { 4684 vfsconf_sunlock(); 4685 return (error); 4686 } 4687 } 4688 vfsconf_sunlock(); 4689 return (0); 4690 } 4691 4692 #endif /* 1 || COMPAT_PRELITE2 */ 4693 #endif /* !BURN_BRIDGES */ 4694 4695 #define KINFO_VNODESLOP 10 4696 #ifdef notyet 4697 /* 4698 * Dump vnode list (via sysctl). 4699 */ 4700 /* ARGSUSED */ 4701 static int 4702 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4703 { 4704 struct xvnode *xvn; 4705 struct mount *mp; 4706 struct vnode *vp; 4707 int error, len, n; 4708 4709 /* 4710 * Stale numvnodes access is not fatal here. 4711 */ 4712 req->lock = 0; 4713 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4714 if (!req->oldptr) 4715 /* Make an estimate */ 4716 return (SYSCTL_OUT(req, 0, len)); 4717 4718 error = sysctl_wire_old_buffer(req, 0); 4719 if (error != 0) 4720 return (error); 4721 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4722 n = 0; 4723 mtx_lock(&mountlist_mtx); 4724 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4725 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4726 continue; 4727 MNT_ILOCK(mp); 4728 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4729 if (n == len) 4730 break; 4731 vref(vp); 4732 xvn[n].xv_size = sizeof *xvn; 4733 xvn[n].xv_vnode = vp; 4734 xvn[n].xv_id = 0; /* XXX compat */ 4735 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4736 XV_COPY(usecount); 4737 XV_COPY(writecount); 4738 XV_COPY(holdcnt); 4739 XV_COPY(mount); 4740 XV_COPY(numoutput); 4741 XV_COPY(type); 4742 #undef XV_COPY 4743 xvn[n].xv_flag = vp->v_vflag; 4744 4745 switch (vp->v_type) { 4746 case VREG: 4747 case VDIR: 4748 case VLNK: 4749 break; 4750 case VBLK: 4751 case VCHR: 4752 if (vp->v_rdev == NULL) { 4753 vrele(vp); 4754 continue; 4755 } 4756 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4757 break; 4758 case VSOCK: 4759 xvn[n].xv_socket = vp->v_socket; 4760 break; 4761 case VFIFO: 4762 xvn[n].xv_fifo = vp->v_fifoinfo; 4763 break; 4764 case VNON: 4765 case VBAD: 4766 default: 4767 /* shouldn't happen? */ 4768 vrele(vp); 4769 continue; 4770 } 4771 vrele(vp); 4772 ++n; 4773 } 4774 MNT_IUNLOCK(mp); 4775 mtx_lock(&mountlist_mtx); 4776 vfs_unbusy(mp); 4777 if (n == len) 4778 break; 4779 } 4780 mtx_unlock(&mountlist_mtx); 4781 4782 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4783 free(xvn, M_TEMP); 4784 return (error); 4785 } 4786 4787 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4788 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4789 ""); 4790 #endif 4791 4792 static void 4793 unmount_or_warn(struct mount *mp) 4794 { 4795 int error; 4796 4797 error = dounmount(mp, MNT_FORCE, curthread); 4798 if (error != 0) { 4799 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4800 if (error == EBUSY) 4801 printf("BUSY)\n"); 4802 else 4803 printf("%d)\n", error); 4804 } 4805 } 4806 4807 /* 4808 * Unmount all filesystems. The list is traversed in reverse order 4809 * of mounting to avoid dependencies. 4810 */ 4811 void 4812 vfs_unmountall(void) 4813 { 4814 struct mount *mp, *tmp; 4815 4816 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4817 4818 /* 4819 * Since this only runs when rebooting, it is not interlocked. 4820 */ 4821 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4822 vfs_ref(mp); 4823 4824 /* 4825 * Forcibly unmounting "/dev" before "/" would prevent clean 4826 * unmount of the latter. 4827 */ 4828 if (mp == rootdevmp) 4829 continue; 4830 4831 unmount_or_warn(mp); 4832 } 4833 4834 if (rootdevmp != NULL) 4835 unmount_or_warn(rootdevmp); 4836 } 4837 4838 static void 4839 vfs_deferred_inactive(struct vnode *vp, int lkflags) 4840 { 4841 4842 ASSERT_VI_LOCKED(vp, __func__); 4843 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, ("VI_DEFINACT still set")); 4844 if ((vp->v_iflag & VI_OWEINACT) == 0) { 4845 vdropl(vp); 4846 return; 4847 } 4848 if (vn_lock(vp, lkflags) == 0) { 4849 VI_LOCK(vp); 4850 vinactive(vp); 4851 VOP_UNLOCK(vp); 4852 vdropl(vp); 4853 return; 4854 } 4855 vdefer_inactive_unlocked(vp); 4856 } 4857 4858 static int 4859 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 4860 { 4861 4862 return (vp->v_iflag & VI_DEFINACT); 4863 } 4864 4865 static void __noinline 4866 vfs_periodic_inactive(struct mount *mp, int flags) 4867 { 4868 struct vnode *vp, *mvp; 4869 int lkflags; 4870 4871 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4872 if (flags != MNT_WAIT) 4873 lkflags |= LK_NOWAIT; 4874 4875 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 4876 if ((vp->v_iflag & VI_DEFINACT) == 0) { 4877 VI_UNLOCK(vp); 4878 continue; 4879 } 4880 vp->v_iflag &= ~VI_DEFINACT; 4881 vfs_deferred_inactive(vp, lkflags); 4882 } 4883 } 4884 4885 static inline bool 4886 vfs_want_msync(struct vnode *vp) 4887 { 4888 struct vm_object *obj; 4889 4890 /* 4891 * This test may be performed without any locks held. 4892 * We rely on vm_object's type stability. 4893 */ 4894 if (vp->v_vflag & VV_NOSYNC) 4895 return (false); 4896 obj = vp->v_object; 4897 return (obj != NULL && vm_object_mightbedirty(obj)); 4898 } 4899 4900 static int 4901 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 4902 { 4903 4904 if (vp->v_vflag & VV_NOSYNC) 4905 return (false); 4906 if (vp->v_iflag & VI_DEFINACT) 4907 return (true); 4908 return (vfs_want_msync(vp)); 4909 } 4910 4911 static void __noinline 4912 vfs_periodic_msync_inactive(struct mount *mp, int flags) 4913 { 4914 struct vnode *vp, *mvp; 4915 struct vm_object *obj; 4916 struct thread *td; 4917 int lkflags, objflags; 4918 bool seen_defer; 4919 4920 td = curthread; 4921 4922 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4923 if (flags != MNT_WAIT) { 4924 lkflags |= LK_NOWAIT; 4925 objflags = OBJPC_NOSYNC; 4926 } else { 4927 objflags = OBJPC_SYNC; 4928 } 4929 4930 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 4931 seen_defer = false; 4932 if (vp->v_iflag & VI_DEFINACT) { 4933 vp->v_iflag &= ~VI_DEFINACT; 4934 seen_defer = true; 4935 } 4936 if (!vfs_want_msync(vp)) { 4937 if (seen_defer) 4938 vfs_deferred_inactive(vp, lkflags); 4939 else 4940 VI_UNLOCK(vp); 4941 continue; 4942 } 4943 if (vget(vp, lkflags, td) == 0) { 4944 obj = vp->v_object; 4945 if (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0) { 4946 VM_OBJECT_WLOCK(obj); 4947 vm_object_page_clean(obj, 0, 0, objflags); 4948 VM_OBJECT_WUNLOCK(obj); 4949 } 4950 vput(vp); 4951 if (seen_defer) 4952 vdrop(vp); 4953 } else { 4954 if (seen_defer) 4955 vdefer_inactive_unlocked(vp); 4956 } 4957 } 4958 } 4959 4960 void 4961 vfs_periodic(struct mount *mp, int flags) 4962 { 4963 4964 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4965 4966 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4967 vfs_periodic_inactive(mp, flags); 4968 else 4969 vfs_periodic_msync_inactive(mp, flags); 4970 } 4971 4972 static void 4973 destroy_vpollinfo_free(struct vpollinfo *vi) 4974 { 4975 4976 knlist_destroy(&vi->vpi_selinfo.si_note); 4977 mtx_destroy(&vi->vpi_lock); 4978 uma_zfree(vnodepoll_zone, vi); 4979 } 4980 4981 static void 4982 destroy_vpollinfo(struct vpollinfo *vi) 4983 { 4984 4985 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4986 seldrain(&vi->vpi_selinfo); 4987 destroy_vpollinfo_free(vi); 4988 } 4989 4990 /* 4991 * Initialize per-vnode helper structure to hold poll-related state. 4992 */ 4993 void 4994 v_addpollinfo(struct vnode *vp) 4995 { 4996 struct vpollinfo *vi; 4997 4998 if (vp->v_pollinfo != NULL) 4999 return; 5000 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 5001 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 5002 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 5003 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 5004 VI_LOCK(vp); 5005 if (vp->v_pollinfo != NULL) { 5006 VI_UNLOCK(vp); 5007 destroy_vpollinfo_free(vi); 5008 return; 5009 } 5010 vp->v_pollinfo = vi; 5011 VI_UNLOCK(vp); 5012 } 5013 5014 /* 5015 * Record a process's interest in events which might happen to 5016 * a vnode. Because poll uses the historic select-style interface 5017 * internally, this routine serves as both the ``check for any 5018 * pending events'' and the ``record my interest in future events'' 5019 * functions. (These are done together, while the lock is held, 5020 * to avoid race conditions.) 5021 */ 5022 int 5023 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 5024 { 5025 5026 v_addpollinfo(vp); 5027 mtx_lock(&vp->v_pollinfo->vpi_lock); 5028 if (vp->v_pollinfo->vpi_revents & events) { 5029 /* 5030 * This leaves events we are not interested 5031 * in available for the other process which 5032 * which presumably had requested them 5033 * (otherwise they would never have been 5034 * recorded). 5035 */ 5036 events &= vp->v_pollinfo->vpi_revents; 5037 vp->v_pollinfo->vpi_revents &= ~events; 5038 5039 mtx_unlock(&vp->v_pollinfo->vpi_lock); 5040 return (events); 5041 } 5042 vp->v_pollinfo->vpi_events |= events; 5043 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 5044 mtx_unlock(&vp->v_pollinfo->vpi_lock); 5045 return (0); 5046 } 5047 5048 /* 5049 * Routine to create and manage a filesystem syncer vnode. 5050 */ 5051 #define sync_close ((int (*)(struct vop_close_args *))nullop) 5052 static int sync_fsync(struct vop_fsync_args *); 5053 static int sync_inactive(struct vop_inactive_args *); 5054 static int sync_reclaim(struct vop_reclaim_args *); 5055 5056 static struct vop_vector sync_vnodeops = { 5057 .vop_bypass = VOP_EOPNOTSUPP, 5058 .vop_close = sync_close, /* close */ 5059 .vop_fsync = sync_fsync, /* fsync */ 5060 .vop_inactive = sync_inactive, /* inactive */ 5061 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 5062 .vop_reclaim = sync_reclaim, /* reclaim */ 5063 .vop_lock1 = vop_stdlock, /* lock */ 5064 .vop_unlock = vop_stdunlock, /* unlock */ 5065 .vop_islocked = vop_stdislocked, /* islocked */ 5066 }; 5067 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 5068 5069 /* 5070 * Create a new filesystem syncer vnode for the specified mount point. 5071 */ 5072 void 5073 vfs_allocate_syncvnode(struct mount *mp) 5074 { 5075 struct vnode *vp; 5076 struct bufobj *bo; 5077 static long start, incr, next; 5078 int error; 5079 5080 /* Allocate a new vnode */ 5081 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 5082 if (error != 0) 5083 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 5084 vp->v_type = VNON; 5085 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5086 vp->v_vflag |= VV_FORCEINSMQ; 5087 error = insmntque(vp, mp); 5088 if (error != 0) 5089 panic("vfs_allocate_syncvnode: insmntque() failed"); 5090 vp->v_vflag &= ~VV_FORCEINSMQ; 5091 VOP_UNLOCK(vp); 5092 /* 5093 * Place the vnode onto the syncer worklist. We attempt to 5094 * scatter them about on the list so that they will go off 5095 * at evenly distributed times even if all the filesystems 5096 * are mounted at once. 5097 */ 5098 next += incr; 5099 if (next == 0 || next > syncer_maxdelay) { 5100 start /= 2; 5101 incr /= 2; 5102 if (start == 0) { 5103 start = syncer_maxdelay / 2; 5104 incr = syncer_maxdelay; 5105 } 5106 next = start; 5107 } 5108 bo = &vp->v_bufobj; 5109 BO_LOCK(bo); 5110 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 5111 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 5112 mtx_lock(&sync_mtx); 5113 sync_vnode_count++; 5114 if (mp->mnt_syncer == NULL) { 5115 mp->mnt_syncer = vp; 5116 vp = NULL; 5117 } 5118 mtx_unlock(&sync_mtx); 5119 BO_UNLOCK(bo); 5120 if (vp != NULL) { 5121 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5122 vgone(vp); 5123 vput(vp); 5124 } 5125 } 5126 5127 void 5128 vfs_deallocate_syncvnode(struct mount *mp) 5129 { 5130 struct vnode *vp; 5131 5132 mtx_lock(&sync_mtx); 5133 vp = mp->mnt_syncer; 5134 if (vp != NULL) 5135 mp->mnt_syncer = NULL; 5136 mtx_unlock(&sync_mtx); 5137 if (vp != NULL) 5138 vrele(vp); 5139 } 5140 5141 /* 5142 * Do a lazy sync of the filesystem. 5143 */ 5144 static int 5145 sync_fsync(struct vop_fsync_args *ap) 5146 { 5147 struct vnode *syncvp = ap->a_vp; 5148 struct mount *mp = syncvp->v_mount; 5149 int error, save; 5150 struct bufobj *bo; 5151 5152 /* 5153 * We only need to do something if this is a lazy evaluation. 5154 */ 5155 if (ap->a_waitfor != MNT_LAZY) 5156 return (0); 5157 5158 /* 5159 * Move ourselves to the back of the sync list. 5160 */ 5161 bo = &syncvp->v_bufobj; 5162 BO_LOCK(bo); 5163 vn_syncer_add_to_worklist(bo, syncdelay); 5164 BO_UNLOCK(bo); 5165 5166 /* 5167 * Walk the list of vnodes pushing all that are dirty and 5168 * not already on the sync list. 5169 */ 5170 if (vfs_busy(mp, MBF_NOWAIT) != 0) 5171 return (0); 5172 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 5173 vfs_unbusy(mp); 5174 return (0); 5175 } 5176 save = curthread_pflags_set(TDP_SYNCIO); 5177 /* 5178 * The filesystem at hand may be idle with free vnodes stored in the 5179 * batch. Return them instead of letting them stay there indefinitely. 5180 */ 5181 vfs_periodic(mp, MNT_NOWAIT); 5182 error = VFS_SYNC(mp, MNT_LAZY); 5183 curthread_pflags_restore(save); 5184 vn_finished_write(mp); 5185 vfs_unbusy(mp); 5186 return (error); 5187 } 5188 5189 /* 5190 * The syncer vnode is no referenced. 5191 */ 5192 static int 5193 sync_inactive(struct vop_inactive_args *ap) 5194 { 5195 5196 vgone(ap->a_vp); 5197 return (0); 5198 } 5199 5200 /* 5201 * The syncer vnode is no longer needed and is being decommissioned. 5202 * 5203 * Modifications to the worklist must be protected by sync_mtx. 5204 */ 5205 static int 5206 sync_reclaim(struct vop_reclaim_args *ap) 5207 { 5208 struct vnode *vp = ap->a_vp; 5209 struct bufobj *bo; 5210 5211 bo = &vp->v_bufobj; 5212 BO_LOCK(bo); 5213 mtx_lock(&sync_mtx); 5214 if (vp->v_mount->mnt_syncer == vp) 5215 vp->v_mount->mnt_syncer = NULL; 5216 if (bo->bo_flag & BO_ONWORKLST) { 5217 LIST_REMOVE(bo, bo_synclist); 5218 syncer_worklist_len--; 5219 sync_vnode_count--; 5220 bo->bo_flag &= ~BO_ONWORKLST; 5221 } 5222 mtx_unlock(&sync_mtx); 5223 BO_UNLOCK(bo); 5224 5225 return (0); 5226 } 5227 5228 int 5229 vn_need_pageq_flush(struct vnode *vp) 5230 { 5231 struct vm_object *obj; 5232 int need; 5233 5234 MPASS(mtx_owned(VI_MTX(vp))); 5235 need = 0; 5236 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5237 vm_object_mightbedirty(obj)) 5238 need = 1; 5239 return (need); 5240 } 5241 5242 /* 5243 * Check if vnode represents a disk device 5244 */ 5245 int 5246 vn_isdisk(struct vnode *vp, int *errp) 5247 { 5248 int error; 5249 5250 if (vp->v_type != VCHR) { 5251 error = ENOTBLK; 5252 goto out; 5253 } 5254 error = 0; 5255 dev_lock(); 5256 if (vp->v_rdev == NULL) 5257 error = ENXIO; 5258 else if (vp->v_rdev->si_devsw == NULL) 5259 error = ENXIO; 5260 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5261 error = ENOTBLK; 5262 dev_unlock(); 5263 out: 5264 if (errp != NULL) 5265 *errp = error; 5266 return (error == 0); 5267 } 5268 5269 /* 5270 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see 5271 * the comment above cache_fplookup for details. 5272 * 5273 * We never deny as priv_check_cred calls are not yet supported, see vaccess. 5274 */ 5275 int 5276 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred) 5277 { 5278 5279 VFS_SMR_ASSERT_ENTERED(); 5280 5281 /* Check the owner. */ 5282 if (cred->cr_uid == file_uid) { 5283 if (file_mode & S_IXUSR) 5284 return (0); 5285 return (EAGAIN); 5286 } 5287 5288 /* Otherwise, check the groups (first match) */ 5289 if (groupmember(file_gid, cred)) { 5290 if (file_mode & S_IXGRP) 5291 return (0); 5292 return (EAGAIN); 5293 } 5294 5295 /* Otherwise, check everyone else. */ 5296 if (file_mode & S_IXOTH) 5297 return (0); 5298 return (EAGAIN); 5299 } 5300 5301 /* 5302 * Common filesystem object access control check routine. Accepts a 5303 * vnode's type, "mode", uid and gid, requested access mode, credentials, 5304 * and optional call-by-reference privused argument allowing vaccess() 5305 * to indicate to the caller whether privilege was used to satisfy the 5306 * request (obsoleted). Returns 0 on success, or an errno on failure. 5307 */ 5308 int 5309 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5310 accmode_t accmode, struct ucred *cred, int *privused) 5311 { 5312 accmode_t dac_granted; 5313 accmode_t priv_granted; 5314 5315 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5316 ("invalid bit in accmode")); 5317 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5318 ("VAPPEND without VWRITE")); 5319 5320 /* 5321 * Look for a normal, non-privileged way to access the file/directory 5322 * as requested. If it exists, go with that. 5323 */ 5324 5325 if (privused != NULL) 5326 *privused = 0; 5327 5328 dac_granted = 0; 5329 5330 /* Check the owner. */ 5331 if (cred->cr_uid == file_uid) { 5332 dac_granted |= VADMIN; 5333 if (file_mode & S_IXUSR) 5334 dac_granted |= VEXEC; 5335 if (file_mode & S_IRUSR) 5336 dac_granted |= VREAD; 5337 if (file_mode & S_IWUSR) 5338 dac_granted |= (VWRITE | VAPPEND); 5339 5340 if ((accmode & dac_granted) == accmode) 5341 return (0); 5342 5343 goto privcheck; 5344 } 5345 5346 /* Otherwise, check the groups (first match) */ 5347 if (groupmember(file_gid, cred)) { 5348 if (file_mode & S_IXGRP) 5349 dac_granted |= VEXEC; 5350 if (file_mode & S_IRGRP) 5351 dac_granted |= VREAD; 5352 if (file_mode & S_IWGRP) 5353 dac_granted |= (VWRITE | VAPPEND); 5354 5355 if ((accmode & dac_granted) == accmode) 5356 return (0); 5357 5358 goto privcheck; 5359 } 5360 5361 /* Otherwise, check everyone else. */ 5362 if (file_mode & S_IXOTH) 5363 dac_granted |= VEXEC; 5364 if (file_mode & S_IROTH) 5365 dac_granted |= VREAD; 5366 if (file_mode & S_IWOTH) 5367 dac_granted |= (VWRITE | VAPPEND); 5368 if ((accmode & dac_granted) == accmode) 5369 return (0); 5370 5371 privcheck: 5372 /* 5373 * Build a privilege mask to determine if the set of privileges 5374 * satisfies the requirements when combined with the granted mask 5375 * from above. For each privilege, if the privilege is required, 5376 * bitwise or the request type onto the priv_granted mask. 5377 */ 5378 priv_granted = 0; 5379 5380 if (type == VDIR) { 5381 /* 5382 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5383 * requests, instead of PRIV_VFS_EXEC. 5384 */ 5385 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5386 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5387 priv_granted |= VEXEC; 5388 } else { 5389 /* 5390 * Ensure that at least one execute bit is on. Otherwise, 5391 * a privileged user will always succeed, and we don't want 5392 * this to happen unless the file really is executable. 5393 */ 5394 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5395 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5396 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5397 priv_granted |= VEXEC; 5398 } 5399 5400 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5401 !priv_check_cred(cred, PRIV_VFS_READ)) 5402 priv_granted |= VREAD; 5403 5404 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5405 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5406 priv_granted |= (VWRITE | VAPPEND); 5407 5408 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5409 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5410 priv_granted |= VADMIN; 5411 5412 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5413 /* XXX audit: privilege used */ 5414 if (privused != NULL) 5415 *privused = 1; 5416 return (0); 5417 } 5418 5419 return ((accmode & VADMIN) ? EPERM : EACCES); 5420 } 5421 5422 /* 5423 * Credential check based on process requesting service, and per-attribute 5424 * permissions. 5425 */ 5426 int 5427 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5428 struct thread *td, accmode_t accmode) 5429 { 5430 5431 /* 5432 * Kernel-invoked always succeeds. 5433 */ 5434 if (cred == NOCRED) 5435 return (0); 5436 5437 /* 5438 * Do not allow privileged processes in jail to directly manipulate 5439 * system attributes. 5440 */ 5441 switch (attrnamespace) { 5442 case EXTATTR_NAMESPACE_SYSTEM: 5443 /* Potentially should be: return (EPERM); */ 5444 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5445 case EXTATTR_NAMESPACE_USER: 5446 return (VOP_ACCESS(vp, accmode, cred, td)); 5447 default: 5448 return (EPERM); 5449 } 5450 } 5451 5452 #ifdef DEBUG_VFS_LOCKS 5453 /* 5454 * This only exists to suppress warnings from unlocked specfs accesses. It is 5455 * no longer ok to have an unlocked VFS. 5456 */ 5457 #define IGNORE_LOCK(vp) (KERNEL_PANICKED() || (vp) == NULL || \ 5458 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 5459 5460 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5461 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5462 "Drop into debugger on lock violation"); 5463 5464 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5465 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5466 0, "Check for interlock across VOPs"); 5467 5468 int vfs_badlock_print = 1; /* Print lock violations. */ 5469 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5470 0, "Print lock violations"); 5471 5472 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5473 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5474 0, "Print vnode details on lock violations"); 5475 5476 #ifdef KDB 5477 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5478 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5479 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5480 #endif 5481 5482 static void 5483 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5484 { 5485 5486 #ifdef KDB 5487 if (vfs_badlock_backtrace) 5488 kdb_backtrace(); 5489 #endif 5490 if (vfs_badlock_vnode) 5491 vn_printf(vp, "vnode "); 5492 if (vfs_badlock_print) 5493 printf("%s: %p %s\n", str, (void *)vp, msg); 5494 if (vfs_badlock_ddb) 5495 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5496 } 5497 5498 void 5499 assert_vi_locked(struct vnode *vp, const char *str) 5500 { 5501 5502 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5503 vfs_badlock("interlock is not locked but should be", str, vp); 5504 } 5505 5506 void 5507 assert_vi_unlocked(struct vnode *vp, const char *str) 5508 { 5509 5510 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5511 vfs_badlock("interlock is locked but should not be", str, vp); 5512 } 5513 5514 void 5515 assert_vop_locked(struct vnode *vp, const char *str) 5516 { 5517 int locked; 5518 5519 if (!IGNORE_LOCK(vp)) { 5520 locked = VOP_ISLOCKED(vp); 5521 if (locked == 0 || locked == LK_EXCLOTHER) 5522 vfs_badlock("is not locked but should be", str, vp); 5523 } 5524 } 5525 5526 void 5527 assert_vop_unlocked(struct vnode *vp, const char *str) 5528 { 5529 5530 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5531 vfs_badlock("is locked but should not be", str, vp); 5532 } 5533 5534 void 5535 assert_vop_elocked(struct vnode *vp, const char *str) 5536 { 5537 5538 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5539 vfs_badlock("is not exclusive locked but should be", str, vp); 5540 } 5541 #endif /* DEBUG_VFS_LOCKS */ 5542 5543 void 5544 vop_rename_fail(struct vop_rename_args *ap) 5545 { 5546 5547 if (ap->a_tvp != NULL) 5548 vput(ap->a_tvp); 5549 if (ap->a_tdvp == ap->a_tvp) 5550 vrele(ap->a_tdvp); 5551 else 5552 vput(ap->a_tdvp); 5553 vrele(ap->a_fdvp); 5554 vrele(ap->a_fvp); 5555 } 5556 5557 void 5558 vop_rename_pre(void *ap) 5559 { 5560 struct vop_rename_args *a = ap; 5561 5562 #ifdef DEBUG_VFS_LOCKS 5563 if (a->a_tvp) 5564 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5565 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5566 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5567 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5568 5569 /* Check the source (from). */ 5570 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5571 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5572 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5573 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5574 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5575 5576 /* Check the target. */ 5577 if (a->a_tvp) 5578 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5579 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5580 #endif 5581 /* 5582 * It may be tempting to add vn_seqc_write_begin/end calls here and 5583 * in vop_rename_post but that's not going to work out since some 5584 * filesystems relookup vnodes mid-rename. This is probably a bug. 5585 * 5586 * For now filesystems are expected to do the relevant calls after they 5587 * decide what vnodes to operate on. 5588 */ 5589 if (a->a_tdvp != a->a_fdvp) 5590 vhold(a->a_fdvp); 5591 if (a->a_tvp != a->a_fvp) 5592 vhold(a->a_fvp); 5593 vhold(a->a_tdvp); 5594 if (a->a_tvp) 5595 vhold(a->a_tvp); 5596 } 5597 5598 #ifdef DEBUG_VFS_LOCKS 5599 void 5600 vop_fplookup_vexec_debugpre(void *ap __unused) 5601 { 5602 5603 VFS_SMR_ASSERT_ENTERED(); 5604 } 5605 5606 void 5607 vop_fplookup_vexec_debugpost(void *ap __unused, int rc __unused) 5608 { 5609 5610 VFS_SMR_ASSERT_ENTERED(); 5611 } 5612 5613 void 5614 vop_strategy_debugpre(void *ap) 5615 { 5616 struct vop_strategy_args *a; 5617 struct buf *bp; 5618 5619 a = ap; 5620 bp = a->a_bp; 5621 5622 /* 5623 * Cluster ops lock their component buffers but not the IO container. 5624 */ 5625 if ((bp->b_flags & B_CLUSTER) != 0) 5626 return; 5627 5628 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5629 if (vfs_badlock_print) 5630 printf( 5631 "VOP_STRATEGY: bp is not locked but should be\n"); 5632 if (vfs_badlock_ddb) 5633 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5634 } 5635 } 5636 5637 void 5638 vop_lock_debugpre(void *ap) 5639 { 5640 struct vop_lock1_args *a = ap; 5641 5642 if ((a->a_flags & LK_INTERLOCK) == 0) 5643 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5644 else 5645 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5646 } 5647 5648 void 5649 vop_lock_debugpost(void *ap, int rc) 5650 { 5651 struct vop_lock1_args *a = ap; 5652 5653 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5654 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5655 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5656 } 5657 5658 void 5659 vop_unlock_debugpre(void *ap) 5660 { 5661 struct vop_unlock_args *a = ap; 5662 5663 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5664 } 5665 5666 void 5667 vop_need_inactive_debugpre(void *ap) 5668 { 5669 struct vop_need_inactive_args *a = ap; 5670 5671 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5672 } 5673 5674 void 5675 vop_need_inactive_debugpost(void *ap, int rc) 5676 { 5677 struct vop_need_inactive_args *a = ap; 5678 5679 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5680 } 5681 #endif 5682 5683 void 5684 vop_create_pre(void *ap) 5685 { 5686 struct vop_create_args *a; 5687 struct vnode *dvp; 5688 5689 a = ap; 5690 dvp = a->a_dvp; 5691 vn_seqc_write_begin(dvp); 5692 } 5693 5694 void 5695 vop_create_post(void *ap, int rc) 5696 { 5697 struct vop_create_args *a; 5698 struct vnode *dvp; 5699 5700 a = ap; 5701 dvp = a->a_dvp; 5702 vn_seqc_write_end(dvp); 5703 if (!rc) 5704 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5705 } 5706 5707 void 5708 vop_whiteout_pre(void *ap) 5709 { 5710 struct vop_whiteout_args *a; 5711 struct vnode *dvp; 5712 5713 a = ap; 5714 dvp = a->a_dvp; 5715 vn_seqc_write_begin(dvp); 5716 } 5717 5718 void 5719 vop_whiteout_post(void *ap, int rc) 5720 { 5721 struct vop_whiteout_args *a; 5722 struct vnode *dvp; 5723 5724 a = ap; 5725 dvp = a->a_dvp; 5726 vn_seqc_write_end(dvp); 5727 } 5728 5729 void 5730 vop_deleteextattr_pre(void *ap) 5731 { 5732 struct vop_deleteextattr_args *a; 5733 struct vnode *vp; 5734 5735 a = ap; 5736 vp = a->a_vp; 5737 vn_seqc_write_begin(vp); 5738 } 5739 5740 void 5741 vop_deleteextattr_post(void *ap, int rc) 5742 { 5743 struct vop_deleteextattr_args *a; 5744 struct vnode *vp; 5745 5746 a = ap; 5747 vp = a->a_vp; 5748 vn_seqc_write_end(vp); 5749 if (!rc) 5750 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5751 } 5752 5753 void 5754 vop_link_pre(void *ap) 5755 { 5756 struct vop_link_args *a; 5757 struct vnode *vp, *tdvp; 5758 5759 a = ap; 5760 vp = a->a_vp; 5761 tdvp = a->a_tdvp; 5762 vn_seqc_write_begin(vp); 5763 vn_seqc_write_begin(tdvp); 5764 } 5765 5766 void 5767 vop_link_post(void *ap, int rc) 5768 { 5769 struct vop_link_args *a; 5770 struct vnode *vp, *tdvp; 5771 5772 a = ap; 5773 vp = a->a_vp; 5774 tdvp = a->a_tdvp; 5775 vn_seqc_write_end(vp); 5776 vn_seqc_write_end(tdvp); 5777 if (!rc) { 5778 VFS_KNOTE_LOCKED(vp, NOTE_LINK); 5779 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE); 5780 } 5781 } 5782 5783 void 5784 vop_mkdir_pre(void *ap) 5785 { 5786 struct vop_mkdir_args *a; 5787 struct vnode *dvp; 5788 5789 a = ap; 5790 dvp = a->a_dvp; 5791 vn_seqc_write_begin(dvp); 5792 } 5793 5794 void 5795 vop_mkdir_post(void *ap, int rc) 5796 { 5797 struct vop_mkdir_args *a; 5798 struct vnode *dvp; 5799 5800 a = ap; 5801 dvp = a->a_dvp; 5802 vn_seqc_write_end(dvp); 5803 if (!rc) 5804 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 5805 } 5806 5807 void 5808 vop_mknod_pre(void *ap) 5809 { 5810 struct vop_mknod_args *a; 5811 struct vnode *dvp; 5812 5813 a = ap; 5814 dvp = a->a_dvp; 5815 vn_seqc_write_begin(dvp); 5816 } 5817 5818 void 5819 vop_mknod_post(void *ap, int rc) 5820 { 5821 struct vop_mknod_args *a; 5822 struct vnode *dvp; 5823 5824 a = ap; 5825 dvp = a->a_dvp; 5826 vn_seqc_write_end(dvp); 5827 if (!rc) 5828 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5829 } 5830 5831 void 5832 vop_reclaim_post(void *ap, int rc) 5833 { 5834 struct vop_reclaim_args *a; 5835 struct vnode *vp; 5836 5837 a = ap; 5838 vp = a->a_vp; 5839 ASSERT_VOP_IN_SEQC(vp); 5840 if (!rc) 5841 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE); 5842 } 5843 5844 void 5845 vop_remove_pre(void *ap) 5846 { 5847 struct vop_remove_args *a; 5848 struct vnode *dvp, *vp; 5849 5850 a = ap; 5851 dvp = a->a_dvp; 5852 vp = a->a_vp; 5853 vn_seqc_write_begin(dvp); 5854 vn_seqc_write_begin(vp); 5855 } 5856 5857 void 5858 vop_remove_post(void *ap, int rc) 5859 { 5860 struct vop_remove_args *a; 5861 struct vnode *dvp, *vp; 5862 5863 a = ap; 5864 dvp = a->a_dvp; 5865 vp = a->a_vp; 5866 vn_seqc_write_end(dvp); 5867 vn_seqc_write_end(vp); 5868 if (!rc) { 5869 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5870 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 5871 } 5872 } 5873 5874 void 5875 vop_rename_post(void *ap, int rc) 5876 { 5877 struct vop_rename_args *a = ap; 5878 long hint; 5879 5880 if (!rc) { 5881 hint = NOTE_WRITE; 5882 if (a->a_fdvp == a->a_tdvp) { 5883 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5884 hint |= NOTE_LINK; 5885 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5886 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5887 } else { 5888 hint |= NOTE_EXTEND; 5889 if (a->a_fvp->v_type == VDIR) 5890 hint |= NOTE_LINK; 5891 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5892 5893 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5894 a->a_tvp->v_type == VDIR) 5895 hint &= ~NOTE_LINK; 5896 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5897 } 5898 5899 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5900 if (a->a_tvp) 5901 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5902 } 5903 if (a->a_tdvp != a->a_fdvp) 5904 vdrop(a->a_fdvp); 5905 if (a->a_tvp != a->a_fvp) 5906 vdrop(a->a_fvp); 5907 vdrop(a->a_tdvp); 5908 if (a->a_tvp) 5909 vdrop(a->a_tvp); 5910 } 5911 5912 void 5913 vop_rmdir_pre(void *ap) 5914 { 5915 struct vop_rmdir_args *a; 5916 struct vnode *dvp, *vp; 5917 5918 a = ap; 5919 dvp = a->a_dvp; 5920 vp = a->a_vp; 5921 vn_seqc_write_begin(dvp); 5922 vn_seqc_write_begin(vp); 5923 } 5924 5925 void 5926 vop_rmdir_post(void *ap, int rc) 5927 { 5928 struct vop_rmdir_args *a; 5929 struct vnode *dvp, *vp; 5930 5931 a = ap; 5932 dvp = a->a_dvp; 5933 vp = a->a_vp; 5934 vn_seqc_write_end(dvp); 5935 vn_seqc_write_end(vp); 5936 if (!rc) { 5937 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 5938 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 5939 } 5940 } 5941 5942 void 5943 vop_setattr_pre(void *ap) 5944 { 5945 struct vop_setattr_args *a; 5946 struct vnode *vp; 5947 5948 a = ap; 5949 vp = a->a_vp; 5950 vn_seqc_write_begin(vp); 5951 } 5952 5953 void 5954 vop_setattr_post(void *ap, int rc) 5955 { 5956 struct vop_setattr_args *a; 5957 struct vnode *vp; 5958 5959 a = ap; 5960 vp = a->a_vp; 5961 vn_seqc_write_end(vp); 5962 if (!rc) 5963 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 5964 } 5965 5966 void 5967 vop_setacl_pre(void *ap) 5968 { 5969 struct vop_setacl_args *a; 5970 struct vnode *vp; 5971 5972 a = ap; 5973 vp = a->a_vp; 5974 vn_seqc_write_begin(vp); 5975 } 5976 5977 void 5978 vop_setacl_post(void *ap, int rc __unused) 5979 { 5980 struct vop_setacl_args *a; 5981 struct vnode *vp; 5982 5983 a = ap; 5984 vp = a->a_vp; 5985 vn_seqc_write_end(vp); 5986 } 5987 5988 void 5989 vop_setextattr_pre(void *ap) 5990 { 5991 struct vop_setextattr_args *a; 5992 struct vnode *vp; 5993 5994 a = ap; 5995 vp = a->a_vp; 5996 vn_seqc_write_begin(vp); 5997 } 5998 5999 void 6000 vop_setextattr_post(void *ap, int rc) 6001 { 6002 struct vop_setextattr_args *a; 6003 struct vnode *vp; 6004 6005 a = ap; 6006 vp = a->a_vp; 6007 vn_seqc_write_end(vp); 6008 if (!rc) 6009 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 6010 } 6011 6012 void 6013 vop_symlink_pre(void *ap) 6014 { 6015 struct vop_symlink_args *a; 6016 struct vnode *dvp; 6017 6018 a = ap; 6019 dvp = a->a_dvp; 6020 vn_seqc_write_begin(dvp); 6021 } 6022 6023 void 6024 vop_symlink_post(void *ap, int rc) 6025 { 6026 struct vop_symlink_args *a; 6027 struct vnode *dvp; 6028 6029 a = ap; 6030 dvp = a->a_dvp; 6031 vn_seqc_write_end(dvp); 6032 if (!rc) 6033 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 6034 } 6035 6036 void 6037 vop_open_post(void *ap, int rc) 6038 { 6039 struct vop_open_args *a = ap; 6040 6041 if (!rc) 6042 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 6043 } 6044 6045 void 6046 vop_close_post(void *ap, int rc) 6047 { 6048 struct vop_close_args *a = ap; 6049 6050 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 6051 !VN_IS_DOOMED(a->a_vp))) { 6052 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 6053 NOTE_CLOSE_WRITE : NOTE_CLOSE); 6054 } 6055 } 6056 6057 void 6058 vop_read_post(void *ap, int rc) 6059 { 6060 struct vop_read_args *a = ap; 6061 6062 if (!rc) 6063 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 6064 } 6065 6066 void 6067 vop_readdir_post(void *ap, int rc) 6068 { 6069 struct vop_readdir_args *a = ap; 6070 6071 if (!rc) 6072 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 6073 } 6074 6075 static struct knlist fs_knlist; 6076 6077 static void 6078 vfs_event_init(void *arg) 6079 { 6080 knlist_init_mtx(&fs_knlist, NULL); 6081 } 6082 /* XXX - correct order? */ 6083 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 6084 6085 void 6086 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 6087 { 6088 6089 KNOTE_UNLOCKED(&fs_knlist, event); 6090 } 6091 6092 static int filt_fsattach(struct knote *kn); 6093 static void filt_fsdetach(struct knote *kn); 6094 static int filt_fsevent(struct knote *kn, long hint); 6095 6096 struct filterops fs_filtops = { 6097 .f_isfd = 0, 6098 .f_attach = filt_fsattach, 6099 .f_detach = filt_fsdetach, 6100 .f_event = filt_fsevent 6101 }; 6102 6103 static int 6104 filt_fsattach(struct knote *kn) 6105 { 6106 6107 kn->kn_flags |= EV_CLEAR; 6108 knlist_add(&fs_knlist, kn, 0); 6109 return (0); 6110 } 6111 6112 static void 6113 filt_fsdetach(struct knote *kn) 6114 { 6115 6116 knlist_remove(&fs_knlist, kn, 0); 6117 } 6118 6119 static int 6120 filt_fsevent(struct knote *kn, long hint) 6121 { 6122 6123 kn->kn_fflags |= hint; 6124 return (kn->kn_fflags != 0); 6125 } 6126 6127 static int 6128 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 6129 { 6130 struct vfsidctl vc; 6131 int error; 6132 struct mount *mp; 6133 6134 error = SYSCTL_IN(req, &vc, sizeof(vc)); 6135 if (error) 6136 return (error); 6137 if (vc.vc_vers != VFS_CTL_VERS1) 6138 return (EINVAL); 6139 mp = vfs_getvfs(&vc.vc_fsid); 6140 if (mp == NULL) 6141 return (ENOENT); 6142 /* ensure that a specific sysctl goes to the right filesystem. */ 6143 if (strcmp(vc.vc_fstypename, "*") != 0 && 6144 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 6145 vfs_rel(mp); 6146 return (EINVAL); 6147 } 6148 VCTLTOREQ(&vc, req); 6149 error = VFS_SYSCTL(mp, vc.vc_op, req); 6150 vfs_rel(mp); 6151 return (error); 6152 } 6153 6154 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 6155 NULL, 0, sysctl_vfs_ctl, "", 6156 "Sysctl by fsid"); 6157 6158 /* 6159 * Function to initialize a va_filerev field sensibly. 6160 * XXX: Wouldn't a random number make a lot more sense ?? 6161 */ 6162 u_quad_t 6163 init_va_filerev(void) 6164 { 6165 struct bintime bt; 6166 6167 getbinuptime(&bt); 6168 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 6169 } 6170 6171 static int filt_vfsread(struct knote *kn, long hint); 6172 static int filt_vfswrite(struct knote *kn, long hint); 6173 static int filt_vfsvnode(struct knote *kn, long hint); 6174 static void filt_vfsdetach(struct knote *kn); 6175 static struct filterops vfsread_filtops = { 6176 .f_isfd = 1, 6177 .f_detach = filt_vfsdetach, 6178 .f_event = filt_vfsread 6179 }; 6180 static struct filterops vfswrite_filtops = { 6181 .f_isfd = 1, 6182 .f_detach = filt_vfsdetach, 6183 .f_event = filt_vfswrite 6184 }; 6185 static struct filterops vfsvnode_filtops = { 6186 .f_isfd = 1, 6187 .f_detach = filt_vfsdetach, 6188 .f_event = filt_vfsvnode 6189 }; 6190 6191 static void 6192 vfs_knllock(void *arg) 6193 { 6194 struct vnode *vp = arg; 6195 6196 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 6197 } 6198 6199 static void 6200 vfs_knlunlock(void *arg) 6201 { 6202 struct vnode *vp = arg; 6203 6204 VOP_UNLOCK(vp); 6205 } 6206 6207 static void 6208 vfs_knl_assert_locked(void *arg) 6209 { 6210 #ifdef DEBUG_VFS_LOCKS 6211 struct vnode *vp = arg; 6212 6213 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 6214 #endif 6215 } 6216 6217 static void 6218 vfs_knl_assert_unlocked(void *arg) 6219 { 6220 #ifdef DEBUG_VFS_LOCKS 6221 struct vnode *vp = arg; 6222 6223 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 6224 #endif 6225 } 6226 6227 int 6228 vfs_kqfilter(struct vop_kqfilter_args *ap) 6229 { 6230 struct vnode *vp = ap->a_vp; 6231 struct knote *kn = ap->a_kn; 6232 struct knlist *knl; 6233 6234 switch (kn->kn_filter) { 6235 case EVFILT_READ: 6236 kn->kn_fop = &vfsread_filtops; 6237 break; 6238 case EVFILT_WRITE: 6239 kn->kn_fop = &vfswrite_filtops; 6240 break; 6241 case EVFILT_VNODE: 6242 kn->kn_fop = &vfsvnode_filtops; 6243 break; 6244 default: 6245 return (EINVAL); 6246 } 6247 6248 kn->kn_hook = (caddr_t)vp; 6249 6250 v_addpollinfo(vp); 6251 if (vp->v_pollinfo == NULL) 6252 return (ENOMEM); 6253 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 6254 vhold(vp); 6255 knlist_add(knl, kn, 0); 6256 6257 return (0); 6258 } 6259 6260 /* 6261 * Detach knote from vnode 6262 */ 6263 static void 6264 filt_vfsdetach(struct knote *kn) 6265 { 6266 struct vnode *vp = (struct vnode *)kn->kn_hook; 6267 6268 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 6269 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 6270 vdrop(vp); 6271 } 6272 6273 /*ARGSUSED*/ 6274 static int 6275 filt_vfsread(struct knote *kn, long hint) 6276 { 6277 struct vnode *vp = (struct vnode *)kn->kn_hook; 6278 struct vattr va; 6279 int res; 6280 6281 /* 6282 * filesystem is gone, so set the EOF flag and schedule 6283 * the knote for deletion. 6284 */ 6285 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6286 VI_LOCK(vp); 6287 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6288 VI_UNLOCK(vp); 6289 return (1); 6290 } 6291 6292 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 6293 return (0); 6294 6295 VI_LOCK(vp); 6296 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 6297 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 6298 VI_UNLOCK(vp); 6299 return (res); 6300 } 6301 6302 /*ARGSUSED*/ 6303 static int 6304 filt_vfswrite(struct knote *kn, long hint) 6305 { 6306 struct vnode *vp = (struct vnode *)kn->kn_hook; 6307 6308 VI_LOCK(vp); 6309 6310 /* 6311 * filesystem is gone, so set the EOF flag and schedule 6312 * the knote for deletion. 6313 */ 6314 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 6315 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6316 6317 kn->kn_data = 0; 6318 VI_UNLOCK(vp); 6319 return (1); 6320 } 6321 6322 static int 6323 filt_vfsvnode(struct knote *kn, long hint) 6324 { 6325 struct vnode *vp = (struct vnode *)kn->kn_hook; 6326 int res; 6327 6328 VI_LOCK(vp); 6329 if (kn->kn_sfflags & hint) 6330 kn->kn_fflags |= hint; 6331 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6332 kn->kn_flags |= EV_EOF; 6333 VI_UNLOCK(vp); 6334 return (1); 6335 } 6336 res = (kn->kn_fflags != 0); 6337 VI_UNLOCK(vp); 6338 return (res); 6339 } 6340 6341 /* 6342 * Returns whether the directory is empty or not. 6343 * If it is empty, the return value is 0; otherwise 6344 * the return value is an error value (which may 6345 * be ENOTEMPTY). 6346 */ 6347 int 6348 vfs_emptydir(struct vnode *vp) 6349 { 6350 struct uio uio; 6351 struct iovec iov; 6352 struct dirent *dirent, *dp, *endp; 6353 int error, eof; 6354 6355 error = 0; 6356 eof = 0; 6357 6358 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 6359 6360 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 6361 iov.iov_base = dirent; 6362 iov.iov_len = sizeof(struct dirent); 6363 6364 uio.uio_iov = &iov; 6365 uio.uio_iovcnt = 1; 6366 uio.uio_offset = 0; 6367 uio.uio_resid = sizeof(struct dirent); 6368 uio.uio_segflg = UIO_SYSSPACE; 6369 uio.uio_rw = UIO_READ; 6370 uio.uio_td = curthread; 6371 6372 while (eof == 0 && error == 0) { 6373 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 6374 NULL, NULL); 6375 if (error != 0) 6376 break; 6377 endp = (void *)((uint8_t *)dirent + 6378 sizeof(struct dirent) - uio.uio_resid); 6379 for (dp = dirent; dp < endp; 6380 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 6381 if (dp->d_type == DT_WHT) 6382 continue; 6383 if (dp->d_namlen == 0) 6384 continue; 6385 if (dp->d_type != DT_DIR && 6386 dp->d_type != DT_UNKNOWN) { 6387 error = ENOTEMPTY; 6388 break; 6389 } 6390 if (dp->d_namlen > 2) { 6391 error = ENOTEMPTY; 6392 break; 6393 } 6394 if (dp->d_namlen == 1 && 6395 dp->d_name[0] != '.') { 6396 error = ENOTEMPTY; 6397 break; 6398 } 6399 if (dp->d_namlen == 2 && 6400 dp->d_name[1] != '.') { 6401 error = ENOTEMPTY; 6402 break; 6403 } 6404 uio.uio_resid = sizeof(struct dirent); 6405 } 6406 } 6407 free(dirent, M_TEMP); 6408 return (error); 6409 } 6410 6411 int 6412 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 6413 { 6414 int error; 6415 6416 if (dp->d_reclen > ap->a_uio->uio_resid) 6417 return (ENAMETOOLONG); 6418 error = uiomove(dp, dp->d_reclen, ap->a_uio); 6419 if (error) { 6420 if (ap->a_ncookies != NULL) { 6421 if (ap->a_cookies != NULL) 6422 free(ap->a_cookies, M_TEMP); 6423 ap->a_cookies = NULL; 6424 *ap->a_ncookies = 0; 6425 } 6426 return (error); 6427 } 6428 if (ap->a_ncookies == NULL) 6429 return (0); 6430 6431 KASSERT(ap->a_cookies, 6432 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 6433 6434 *ap->a_cookies = realloc(*ap->a_cookies, 6435 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 6436 (*ap->a_cookies)[*ap->a_ncookies] = off; 6437 *ap->a_ncookies += 1; 6438 return (0); 6439 } 6440 6441 /* 6442 * The purpose of this routine is to remove granularity from accmode_t, 6443 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 6444 * VADMIN and VAPPEND. 6445 * 6446 * If it returns 0, the caller is supposed to continue with the usual 6447 * access checks using 'accmode' as modified by this routine. If it 6448 * returns nonzero value, the caller is supposed to return that value 6449 * as errno. 6450 * 6451 * Note that after this routine runs, accmode may be zero. 6452 */ 6453 int 6454 vfs_unixify_accmode(accmode_t *accmode) 6455 { 6456 /* 6457 * There is no way to specify explicit "deny" rule using 6458 * file mode or POSIX.1e ACLs. 6459 */ 6460 if (*accmode & VEXPLICIT_DENY) { 6461 *accmode = 0; 6462 return (0); 6463 } 6464 6465 /* 6466 * None of these can be translated into usual access bits. 6467 * Also, the common case for NFSv4 ACLs is to not contain 6468 * either of these bits. Caller should check for VWRITE 6469 * on the containing directory instead. 6470 */ 6471 if (*accmode & (VDELETE_CHILD | VDELETE)) 6472 return (EPERM); 6473 6474 if (*accmode & VADMIN_PERMS) { 6475 *accmode &= ~VADMIN_PERMS; 6476 *accmode |= VADMIN; 6477 } 6478 6479 /* 6480 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6481 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6482 */ 6483 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6484 6485 return (0); 6486 } 6487 6488 /* 6489 * Clear out a doomed vnode (if any) and replace it with a new one as long 6490 * as the fs is not being unmounted. Return the root vnode to the caller. 6491 */ 6492 static int __noinline 6493 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6494 { 6495 struct vnode *vp; 6496 int error; 6497 6498 restart: 6499 if (mp->mnt_rootvnode != NULL) { 6500 MNT_ILOCK(mp); 6501 vp = mp->mnt_rootvnode; 6502 if (vp != NULL) { 6503 if (!VN_IS_DOOMED(vp)) { 6504 vrefact(vp); 6505 MNT_IUNLOCK(mp); 6506 error = vn_lock(vp, flags); 6507 if (error == 0) { 6508 *vpp = vp; 6509 return (0); 6510 } 6511 vrele(vp); 6512 goto restart; 6513 } 6514 /* 6515 * Clear the old one. 6516 */ 6517 mp->mnt_rootvnode = NULL; 6518 } 6519 MNT_IUNLOCK(mp); 6520 if (vp != NULL) { 6521 vfs_op_barrier_wait(mp); 6522 vrele(vp); 6523 } 6524 } 6525 error = VFS_CACHEDROOT(mp, flags, vpp); 6526 if (error != 0) 6527 return (error); 6528 if (mp->mnt_vfs_ops == 0) { 6529 MNT_ILOCK(mp); 6530 if (mp->mnt_vfs_ops != 0) { 6531 MNT_IUNLOCK(mp); 6532 return (0); 6533 } 6534 if (mp->mnt_rootvnode == NULL) { 6535 vrefact(*vpp); 6536 mp->mnt_rootvnode = *vpp; 6537 } else { 6538 if (mp->mnt_rootvnode != *vpp) { 6539 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6540 panic("%s: mismatch between vnode returned " 6541 " by VFS_CACHEDROOT and the one cached " 6542 " (%p != %p)", 6543 __func__, *vpp, mp->mnt_rootvnode); 6544 } 6545 } 6546 } 6547 MNT_IUNLOCK(mp); 6548 } 6549 return (0); 6550 } 6551 6552 int 6553 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6554 { 6555 struct vnode *vp; 6556 int error; 6557 6558 if (!vfs_op_thread_enter(mp)) 6559 return (vfs_cache_root_fallback(mp, flags, vpp)); 6560 vp = atomic_load_ptr(&mp->mnt_rootvnode); 6561 if (vp == NULL || VN_IS_DOOMED(vp)) { 6562 vfs_op_thread_exit(mp); 6563 return (vfs_cache_root_fallback(mp, flags, vpp)); 6564 } 6565 vrefact(vp); 6566 vfs_op_thread_exit(mp); 6567 error = vn_lock(vp, flags); 6568 if (error != 0) { 6569 vrele(vp); 6570 return (vfs_cache_root_fallback(mp, flags, vpp)); 6571 } 6572 *vpp = vp; 6573 return (0); 6574 } 6575 6576 struct vnode * 6577 vfs_cache_root_clear(struct mount *mp) 6578 { 6579 struct vnode *vp; 6580 6581 /* 6582 * ops > 0 guarantees there is nobody who can see this vnode 6583 */ 6584 MPASS(mp->mnt_vfs_ops > 0); 6585 vp = mp->mnt_rootvnode; 6586 if (vp != NULL) 6587 vn_seqc_write_begin(vp); 6588 mp->mnt_rootvnode = NULL; 6589 return (vp); 6590 } 6591 6592 void 6593 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6594 { 6595 6596 MPASS(mp->mnt_vfs_ops > 0); 6597 vrefact(vp); 6598 mp->mnt_rootvnode = vp; 6599 } 6600 6601 /* 6602 * These are helper functions for filesystems to traverse all 6603 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6604 * 6605 * This interface replaces MNT_VNODE_FOREACH. 6606 */ 6607 6608 struct vnode * 6609 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6610 { 6611 struct vnode *vp; 6612 6613 if (should_yield()) 6614 kern_yield(PRI_USER); 6615 MNT_ILOCK(mp); 6616 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6617 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6618 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6619 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6620 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6621 continue; 6622 VI_LOCK(vp); 6623 if (VN_IS_DOOMED(vp)) { 6624 VI_UNLOCK(vp); 6625 continue; 6626 } 6627 break; 6628 } 6629 if (vp == NULL) { 6630 __mnt_vnode_markerfree_all(mvp, mp); 6631 /* MNT_IUNLOCK(mp); -- done in above function */ 6632 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6633 return (NULL); 6634 } 6635 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6636 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6637 MNT_IUNLOCK(mp); 6638 return (vp); 6639 } 6640 6641 struct vnode * 6642 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6643 { 6644 struct vnode *vp; 6645 6646 *mvp = vn_alloc_marker(mp); 6647 MNT_ILOCK(mp); 6648 MNT_REF(mp); 6649 6650 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6651 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6652 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6653 continue; 6654 VI_LOCK(vp); 6655 if (VN_IS_DOOMED(vp)) { 6656 VI_UNLOCK(vp); 6657 continue; 6658 } 6659 break; 6660 } 6661 if (vp == NULL) { 6662 MNT_REL(mp); 6663 MNT_IUNLOCK(mp); 6664 vn_free_marker(*mvp); 6665 *mvp = NULL; 6666 return (NULL); 6667 } 6668 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6669 MNT_IUNLOCK(mp); 6670 return (vp); 6671 } 6672 6673 void 6674 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6675 { 6676 6677 if (*mvp == NULL) { 6678 MNT_IUNLOCK(mp); 6679 return; 6680 } 6681 6682 mtx_assert(MNT_MTX(mp), MA_OWNED); 6683 6684 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6685 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6686 MNT_REL(mp); 6687 MNT_IUNLOCK(mp); 6688 vn_free_marker(*mvp); 6689 *mvp = NULL; 6690 } 6691 6692 /* 6693 * These are helper functions for filesystems to traverse their 6694 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6695 */ 6696 static void 6697 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6698 { 6699 6700 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6701 6702 MNT_ILOCK(mp); 6703 MNT_REL(mp); 6704 MNT_IUNLOCK(mp); 6705 vn_free_marker(*mvp); 6706 *mvp = NULL; 6707 } 6708 6709 /* 6710 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6711 * conventional lock order during mnt_vnode_next_lazy iteration. 6712 * 6713 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6714 * The list lock is dropped and reacquired. On success, both locks are held. 6715 * On failure, the mount vnode list lock is held but the vnode interlock is 6716 * not, and the procedure may have yielded. 6717 */ 6718 static bool 6719 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6720 struct vnode *vp) 6721 { 6722 6723 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6724 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6725 ("%s: bad marker", __func__)); 6726 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6727 ("%s: inappropriate vnode", __func__)); 6728 ASSERT_VI_UNLOCKED(vp, __func__); 6729 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6730 6731 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6732 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6733 6734 /* 6735 * Note we may be racing against vdrop which transitioned the hold 6736 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine, 6737 * if we are the only user after we get the interlock we will just 6738 * vdrop. 6739 */ 6740 vhold(vp); 6741 mtx_unlock(&mp->mnt_listmtx); 6742 VI_LOCK(vp); 6743 if (VN_IS_DOOMED(vp)) { 6744 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6745 goto out_lost; 6746 } 6747 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6748 /* 6749 * There is nothing to do if we are the last user. 6750 */ 6751 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6752 goto out_lost; 6753 mtx_lock(&mp->mnt_listmtx); 6754 return (true); 6755 out_lost: 6756 vdropl(vp); 6757 maybe_yield(); 6758 mtx_lock(&mp->mnt_listmtx); 6759 return (false); 6760 } 6761 6762 static struct vnode * 6763 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6764 void *cbarg) 6765 { 6766 struct vnode *vp; 6767 6768 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6769 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6770 restart: 6771 vp = TAILQ_NEXT(*mvp, v_lazylist); 6772 while (vp != NULL) { 6773 if (vp->v_type == VMARKER) { 6774 vp = TAILQ_NEXT(vp, v_lazylist); 6775 continue; 6776 } 6777 /* 6778 * See if we want to process the vnode. Note we may encounter a 6779 * long string of vnodes we don't care about and hog the list 6780 * as a result. Check for it and requeue the marker. 6781 */ 6782 VNPASS(!VN_IS_DOOMED(vp), vp); 6783 if (!cb(vp, cbarg)) { 6784 if (!should_yield()) { 6785 vp = TAILQ_NEXT(vp, v_lazylist); 6786 continue; 6787 } 6788 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 6789 v_lazylist); 6790 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 6791 v_lazylist); 6792 mtx_unlock(&mp->mnt_listmtx); 6793 kern_yield(PRI_USER); 6794 mtx_lock(&mp->mnt_listmtx); 6795 goto restart; 6796 } 6797 /* 6798 * Try-lock because this is the wrong lock order. 6799 */ 6800 if (!VI_TRYLOCK(vp) && 6801 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 6802 goto restart; 6803 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 6804 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 6805 ("alien vnode on the lazy list %p %p", vp, mp)); 6806 VNPASS(vp->v_mount == mp, vp); 6807 VNPASS(!VN_IS_DOOMED(vp), vp); 6808 break; 6809 } 6810 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6811 6812 /* Check if we are done */ 6813 if (vp == NULL) { 6814 mtx_unlock(&mp->mnt_listmtx); 6815 mnt_vnode_markerfree_lazy(mvp, mp); 6816 return (NULL); 6817 } 6818 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 6819 mtx_unlock(&mp->mnt_listmtx); 6820 ASSERT_VI_LOCKED(vp, "lazy iter"); 6821 return (vp); 6822 } 6823 6824 struct vnode * 6825 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6826 void *cbarg) 6827 { 6828 6829 if (should_yield()) 6830 kern_yield(PRI_USER); 6831 mtx_lock(&mp->mnt_listmtx); 6832 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6833 } 6834 6835 struct vnode * 6836 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6837 void *cbarg) 6838 { 6839 struct vnode *vp; 6840 6841 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 6842 return (NULL); 6843 6844 *mvp = vn_alloc_marker(mp); 6845 MNT_ILOCK(mp); 6846 MNT_REF(mp); 6847 MNT_IUNLOCK(mp); 6848 6849 mtx_lock(&mp->mnt_listmtx); 6850 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 6851 if (vp == NULL) { 6852 mtx_unlock(&mp->mnt_listmtx); 6853 mnt_vnode_markerfree_lazy(mvp, mp); 6854 return (NULL); 6855 } 6856 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 6857 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6858 } 6859 6860 void 6861 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6862 { 6863 6864 if (*mvp == NULL) 6865 return; 6866 6867 mtx_lock(&mp->mnt_listmtx); 6868 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6869 mtx_unlock(&mp->mnt_listmtx); 6870 mnt_vnode_markerfree_lazy(mvp, mp); 6871 } 6872 6873 int 6874 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 6875 { 6876 6877 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 6878 cnp->cn_flags &= ~NOEXECCHECK; 6879 return (0); 6880 } 6881 6882 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread)); 6883 } 6884 6885 void 6886 vn_seqc_write_begin_locked(struct vnode *vp) 6887 { 6888 6889 ASSERT_VI_LOCKED(vp, __func__); 6890 VNPASS(vp->v_holdcnt > 0, vp); 6891 VNPASS(vp->v_seqc_users >= 0, vp); 6892 vp->v_seqc_users++; 6893 if (vp->v_seqc_users == 1) 6894 seqc_sleepable_write_begin(&vp->v_seqc); 6895 } 6896 6897 void 6898 vn_seqc_write_begin(struct vnode *vp) 6899 { 6900 6901 VI_LOCK(vp); 6902 vn_seqc_write_begin_locked(vp); 6903 VI_UNLOCK(vp); 6904 } 6905 6906 void 6907 vn_seqc_write_end_locked(struct vnode *vp) 6908 { 6909 6910 ASSERT_VI_LOCKED(vp, __func__); 6911 VNPASS(vp->v_seqc_users > 0, vp); 6912 vp->v_seqc_users--; 6913 if (vp->v_seqc_users == 0) 6914 seqc_sleepable_write_end(&vp->v_seqc); 6915 } 6916 6917 void 6918 vn_seqc_write_end(struct vnode *vp) 6919 { 6920 6921 VI_LOCK(vp); 6922 vn_seqc_write_end_locked(vp); 6923 VI_UNLOCK(vp); 6924 } 6925