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 vgonel(struct vnode *); 112 static void vfs_knllock(void *arg); 113 static void vfs_knlunlock(void *arg); 114 static void vfs_knl_assert_locked(void *arg); 115 static void vfs_knl_assert_unlocked(void *arg); 116 static void destroy_vpollinfo(struct vpollinfo *vi); 117 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 118 daddr_t startlbn, daddr_t endlbn); 119 static void vnlru_recalc(void); 120 121 /* 122 * These fences are intended for cases where some synchronization is 123 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 124 * and v_usecount) updates. Access to v_iflags is generally synchronized 125 * by the interlock, but we have some internal assertions that check vnode 126 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 127 * for now. 128 */ 129 #ifdef INVARIANTS 130 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 131 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 132 #else 133 #define VNODE_REFCOUNT_FENCE_ACQ() 134 #define VNODE_REFCOUNT_FENCE_REL() 135 #endif 136 137 /* 138 * Number of vnodes in existence. Increased whenever getnewvnode() 139 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode. 140 */ 141 static u_long __exclusive_cache_line numvnodes; 142 143 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 144 "Number of vnodes in existence"); 145 146 static counter_u64_t vnodes_created; 147 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 148 "Number of vnodes created by getnewvnode"); 149 150 /* 151 * Conversion tables for conversion from vnode types to inode formats 152 * and back. 153 */ 154 enum vtype iftovt_tab[16] = { 155 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 156 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 157 }; 158 int vttoif_tab[10] = { 159 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 160 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 161 }; 162 163 /* 164 * List of allocates vnodes in the system. 165 */ 166 static TAILQ_HEAD(freelst, vnode) vnode_list; 167 static struct vnode *vnode_list_free_marker; 168 static struct vnode *vnode_list_reclaim_marker; 169 170 /* 171 * "Free" vnode target. Free vnodes are rarely completely free, but are 172 * just ones that are cheap to recycle. Usually they are for files which 173 * have been stat'd but not read; these usually have inode and namecache 174 * data attached to them. This target is the preferred minimum size of a 175 * sub-cache consisting mostly of such files. The system balances the size 176 * of this sub-cache with its complement to try to prevent either from 177 * thrashing while the other is relatively inactive. The targets express 178 * a preference for the best balance. 179 * 180 * "Above" this target there are 2 further targets (watermarks) related 181 * to recyling of free vnodes. In the best-operating case, the cache is 182 * exactly full, the free list has size between vlowat and vhiwat above the 183 * free target, and recycling from it and normal use maintains this state. 184 * Sometimes the free list is below vlowat or even empty, but this state 185 * is even better for immediate use provided the cache is not full. 186 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 187 * ones) to reach one of these states. The watermarks are currently hard- 188 * coded as 4% and 9% of the available space higher. These and the default 189 * of 25% for wantfreevnodes are too large if the memory size is large. 190 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 191 * whenever vnlru_proc() becomes active. 192 */ 193 static long wantfreevnodes; 194 static long __exclusive_cache_line freevnodes; 195 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 196 &freevnodes, 0, "Number of \"free\" vnodes"); 197 static long freevnodes_old; 198 199 static counter_u64_t recycles_count; 200 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 201 "Number of vnodes recycled to meet vnode cache targets"); 202 203 static counter_u64_t recycles_free_count; 204 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD, &recycles_free_count, 205 "Number of free vnodes recycled to meet vnode cache targets"); 206 207 static counter_u64_t deferred_inact; 208 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD, &deferred_inact, 209 "Number of times inactive processing was deferred"); 210 211 /* To keep more than one thread at a time from running vfs_getnewfsid */ 212 static struct mtx mntid_mtx; 213 214 /* 215 * Lock for any access to the following: 216 * vnode_list 217 * numvnodes 218 * freevnodes 219 */ 220 static struct mtx __exclusive_cache_line vnode_list_mtx; 221 222 /* Publicly exported FS */ 223 struct nfs_public nfs_pub; 224 225 static uma_zone_t buf_trie_zone; 226 static smr_t buf_trie_smr; 227 228 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 229 static uma_zone_t vnode_zone; 230 static uma_zone_t vnodepoll_zone; 231 232 __read_frequently smr_t vfs_smr; 233 234 /* 235 * The workitem queue. 236 * 237 * It is useful to delay writes of file data and filesystem metadata 238 * for tens of seconds so that quickly created and deleted files need 239 * not waste disk bandwidth being created and removed. To realize this, 240 * we append vnodes to a "workitem" queue. When running with a soft 241 * updates implementation, most pending metadata dependencies should 242 * not wait for more than a few seconds. Thus, mounted on block devices 243 * are delayed only about a half the time that file data is delayed. 244 * Similarly, directory updates are more critical, so are only delayed 245 * about a third the time that file data is delayed. Thus, there are 246 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 247 * one each second (driven off the filesystem syncer process). The 248 * syncer_delayno variable indicates the next queue that is to be processed. 249 * Items that need to be processed soon are placed in this queue: 250 * 251 * syncer_workitem_pending[syncer_delayno] 252 * 253 * A delay of fifteen seconds is done by placing the request fifteen 254 * entries later in the queue: 255 * 256 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 257 * 258 */ 259 static int syncer_delayno; 260 static long syncer_mask; 261 LIST_HEAD(synclist, bufobj); 262 static struct synclist *syncer_workitem_pending; 263 /* 264 * The sync_mtx protects: 265 * bo->bo_synclist 266 * sync_vnode_count 267 * syncer_delayno 268 * syncer_state 269 * syncer_workitem_pending 270 * syncer_worklist_len 271 * rushjob 272 */ 273 static struct mtx sync_mtx; 274 static struct cv sync_wakeup; 275 276 #define SYNCER_MAXDELAY 32 277 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 278 static int syncdelay = 30; /* max time to delay syncing data */ 279 static int filedelay = 30; /* time to delay syncing files */ 280 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 281 "Time to delay syncing files (in seconds)"); 282 static int dirdelay = 29; /* time to delay syncing directories */ 283 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 284 "Time to delay syncing directories (in seconds)"); 285 static int metadelay = 28; /* time to delay syncing metadata */ 286 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 287 "Time to delay syncing metadata (in seconds)"); 288 static int rushjob; /* number of slots to run ASAP */ 289 static int stat_rush_requests; /* number of times I/O speeded up */ 290 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 291 "Number of times I/O speeded up (rush requests)"); 292 293 #define VDBATCH_SIZE 8 294 struct vdbatch { 295 u_int index; 296 long freevnodes; 297 struct mtx lock; 298 struct vnode *tab[VDBATCH_SIZE]; 299 }; 300 DPCPU_DEFINE_STATIC(struct vdbatch, vd); 301 302 static void vdbatch_dequeue(struct vnode *vp); 303 304 /* 305 * When shutting down the syncer, run it at four times normal speed. 306 */ 307 #define SYNCER_SHUTDOWN_SPEEDUP 4 308 static int sync_vnode_count; 309 static int syncer_worklist_len; 310 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 311 syncer_state; 312 313 /* Target for maximum number of vnodes. */ 314 u_long desiredvnodes; 315 static u_long gapvnodes; /* gap between wanted and desired */ 316 static u_long vhiwat; /* enough extras after expansion */ 317 static u_long vlowat; /* minimal extras before expansion */ 318 static u_long vstir; /* nonzero to stir non-free vnodes */ 319 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 320 321 static u_long vnlru_read_freevnodes(void); 322 323 /* 324 * Note that no attempt is made to sanitize these parameters. 325 */ 326 static int 327 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS) 328 { 329 u_long val; 330 int error; 331 332 val = desiredvnodes; 333 error = sysctl_handle_long(oidp, &val, 0, req); 334 if (error != 0 || req->newptr == NULL) 335 return (error); 336 337 if (val == desiredvnodes) 338 return (0); 339 mtx_lock(&vnode_list_mtx); 340 desiredvnodes = val; 341 wantfreevnodes = desiredvnodes / 4; 342 vnlru_recalc(); 343 mtx_unlock(&vnode_list_mtx); 344 /* 345 * XXX There is no protection against multiple threads changing 346 * desiredvnodes at the same time. Locking above only helps vnlru and 347 * getnewvnode. 348 */ 349 vfs_hash_changesize(desiredvnodes); 350 cache_changesize(desiredvnodes); 351 return (0); 352 } 353 354 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 355 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes, 356 "LU", "Target for maximum number of vnodes"); 357 358 static int 359 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS) 360 { 361 u_long val; 362 int error; 363 364 val = wantfreevnodes; 365 error = sysctl_handle_long(oidp, &val, 0, req); 366 if (error != 0 || req->newptr == NULL) 367 return (error); 368 369 if (val == wantfreevnodes) 370 return (0); 371 mtx_lock(&vnode_list_mtx); 372 wantfreevnodes = val; 373 vnlru_recalc(); 374 mtx_unlock(&vnode_list_mtx); 375 return (0); 376 } 377 378 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes, 379 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes, 380 "LU", "Target for minimum number of \"free\" vnodes"); 381 382 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 383 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 384 static int vnlru_nowhere; 385 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 386 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 387 388 static int 389 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 390 { 391 struct vnode *vp; 392 struct nameidata nd; 393 char *buf; 394 unsigned long ndflags; 395 int error; 396 397 if (req->newptr == NULL) 398 return (EINVAL); 399 if (req->newlen >= PATH_MAX) 400 return (E2BIG); 401 402 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK); 403 error = SYSCTL_IN(req, buf, req->newlen); 404 if (error != 0) 405 goto out; 406 407 buf[req->newlen] = '\0'; 408 409 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | SAVENAME; 410 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); 411 if ((error = namei(&nd)) != 0) 412 goto out; 413 vp = nd.ni_vp; 414 415 if (VN_IS_DOOMED(vp)) { 416 /* 417 * This vnode is being recycled. Return != 0 to let the caller 418 * know that the sysctl had no effect. Return EAGAIN because a 419 * subsequent call will likely succeed (since namei will create 420 * a new vnode if necessary) 421 */ 422 error = EAGAIN; 423 goto putvnode; 424 } 425 426 counter_u64_add(recycles_count, 1); 427 vgone(vp); 428 putvnode: 429 NDFREE(&nd, 0); 430 out: 431 free(buf, M_TEMP); 432 return (error); 433 } 434 435 static int 436 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 437 { 438 struct thread *td = curthread; 439 struct vnode *vp; 440 struct file *fp; 441 int error; 442 int fd; 443 444 if (req->newptr == NULL) 445 return (EBADF); 446 447 error = sysctl_handle_int(oidp, &fd, 0, req); 448 if (error != 0) 449 return (error); 450 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 451 if (error != 0) 452 return (error); 453 vp = fp->f_vnode; 454 455 error = vn_lock(vp, LK_EXCLUSIVE); 456 if (error != 0) 457 goto drop; 458 459 counter_u64_add(recycles_count, 1); 460 vgone(vp); 461 VOP_UNLOCK(vp); 462 drop: 463 fdrop(fp, td); 464 return (error); 465 } 466 467 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 468 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 469 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 470 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 471 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 472 sysctl_ftry_reclaim_vnode, "I", 473 "Try to reclaim a vnode by its file descriptor"); 474 475 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 476 static int vnsz2log; 477 478 /* 479 * Support for the bufobj clean & dirty pctrie. 480 */ 481 static void * 482 buf_trie_alloc(struct pctrie *ptree) 483 { 484 return (uma_zalloc_smr(buf_trie_zone, M_NOWAIT)); 485 } 486 487 static void 488 buf_trie_free(struct pctrie *ptree, void *node) 489 { 490 uma_zfree_smr(buf_trie_zone, node); 491 } 492 PCTRIE_DEFINE_SMR(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free, 493 buf_trie_smr); 494 495 /* 496 * Initialize the vnode management data structures. 497 * 498 * Reevaluate the following cap on the number of vnodes after the physical 499 * memory size exceeds 512GB. In the limit, as the physical memory size 500 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 501 */ 502 #ifndef MAXVNODES_MAX 503 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */ 504 #endif 505 506 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 507 508 static struct vnode * 509 vn_alloc_marker(struct mount *mp) 510 { 511 struct vnode *vp; 512 513 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 514 vp->v_type = VMARKER; 515 vp->v_mount = mp; 516 517 return (vp); 518 } 519 520 static void 521 vn_free_marker(struct vnode *vp) 522 { 523 524 MPASS(vp->v_type == VMARKER); 525 free(vp, M_VNODE_MARKER); 526 } 527 528 /* 529 * Initialize a vnode as it first enters the zone. 530 */ 531 static int 532 vnode_init(void *mem, int size, int flags) 533 { 534 struct vnode *vp; 535 536 vp = mem; 537 bzero(vp, size); 538 /* 539 * Setup locks. 540 */ 541 vp->v_vnlock = &vp->v_lock; 542 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 543 /* 544 * By default, don't allow shared locks unless filesystems opt-in. 545 */ 546 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 547 LK_NOSHARE | LK_IS_VNODE); 548 /* 549 * Initialize bufobj. 550 */ 551 bufobj_init(&vp->v_bufobj, vp); 552 /* 553 * Initialize namecache. 554 */ 555 cache_vnode_init(vp); 556 /* 557 * Initialize rangelocks. 558 */ 559 rangelock_init(&vp->v_rl); 560 561 vp->v_dbatchcpu = NOCPU; 562 563 mtx_lock(&vnode_list_mtx); 564 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist); 565 mtx_unlock(&vnode_list_mtx); 566 return (0); 567 } 568 569 /* 570 * Free a vnode when it is cleared from the zone. 571 */ 572 static void 573 vnode_fini(void *mem, int size) 574 { 575 struct vnode *vp; 576 struct bufobj *bo; 577 578 vp = mem; 579 vdbatch_dequeue(vp); 580 mtx_lock(&vnode_list_mtx); 581 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 582 mtx_unlock(&vnode_list_mtx); 583 rangelock_destroy(&vp->v_rl); 584 lockdestroy(vp->v_vnlock); 585 mtx_destroy(&vp->v_interlock); 586 bo = &vp->v_bufobj; 587 rw_destroy(BO_LOCKPTR(bo)); 588 } 589 590 /* 591 * Provide the size of NFS nclnode and NFS fh for calculation of the 592 * vnode memory consumption. The size is specified directly to 593 * eliminate dependency on NFS-private header. 594 * 595 * Other filesystems may use bigger or smaller (like UFS and ZFS) 596 * private inode data, but the NFS-based estimation is ample enough. 597 * Still, we care about differences in the size between 64- and 32-bit 598 * platforms. 599 * 600 * Namecache structure size is heuristically 601 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 602 */ 603 #ifdef _LP64 604 #define NFS_NCLNODE_SZ (528 + 64) 605 #define NC_SZ 148 606 #else 607 #define NFS_NCLNODE_SZ (360 + 32) 608 #define NC_SZ 92 609 #endif 610 611 static void 612 vntblinit(void *dummy __unused) 613 { 614 struct vdbatch *vd; 615 int cpu, physvnodes, virtvnodes; 616 u_int i; 617 618 /* 619 * Desiredvnodes is a function of the physical memory size and the 620 * kernel's heap size. Generally speaking, it scales with the 621 * physical memory size. The ratio of desiredvnodes to the physical 622 * memory size is 1:16 until desiredvnodes exceeds 98,304. 623 * Thereafter, the 624 * marginal ratio of desiredvnodes to the physical memory size is 625 * 1:64. However, desiredvnodes is limited by the kernel's heap 626 * size. The memory required by desiredvnodes vnodes and vm objects 627 * must not exceed 1/10th of the kernel's heap size. 628 */ 629 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 630 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 631 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 632 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 633 desiredvnodes = min(physvnodes, virtvnodes); 634 if (desiredvnodes > MAXVNODES_MAX) { 635 if (bootverbose) 636 printf("Reducing kern.maxvnodes %lu -> %lu\n", 637 desiredvnodes, MAXVNODES_MAX); 638 desiredvnodes = MAXVNODES_MAX; 639 } 640 wantfreevnodes = desiredvnodes / 4; 641 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 642 TAILQ_INIT(&vnode_list); 643 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF); 644 /* 645 * The lock is taken to appease WITNESS. 646 */ 647 mtx_lock(&vnode_list_mtx); 648 vnlru_recalc(); 649 mtx_unlock(&vnode_list_mtx); 650 vnode_list_free_marker = vn_alloc_marker(NULL); 651 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist); 652 vnode_list_reclaim_marker = vn_alloc_marker(NULL); 653 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist); 654 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 655 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 656 uma_zone_set_smr(vnode_zone, vfs_smr); 657 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 658 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 659 /* 660 * Preallocate enough nodes to support one-per buf so that 661 * we can not fail an insert. reassignbuf() callers can not 662 * tolerate the insertion failure. 663 */ 664 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 665 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 666 UMA_ZONE_NOFREE | UMA_ZONE_SMR); 667 buf_trie_smr = uma_zone_get_smr(buf_trie_zone); 668 uma_prealloc(buf_trie_zone, nbuf); 669 670 vnodes_created = counter_u64_alloc(M_WAITOK); 671 recycles_count = counter_u64_alloc(M_WAITOK); 672 recycles_free_count = counter_u64_alloc(M_WAITOK); 673 deferred_inact = counter_u64_alloc(M_WAITOK); 674 675 /* 676 * Initialize the filesystem syncer. 677 */ 678 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 679 &syncer_mask); 680 syncer_maxdelay = syncer_mask + 1; 681 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 682 cv_init(&sync_wakeup, "syncer"); 683 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 684 vnsz2log++; 685 vnsz2log--; 686 687 CPU_FOREACH(cpu) { 688 vd = DPCPU_ID_PTR((cpu), vd); 689 bzero(vd, sizeof(*vd)); 690 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF); 691 } 692 } 693 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 694 695 /* 696 * Mark a mount point as busy. Used to synchronize access and to delay 697 * unmounting. Eventually, mountlist_mtx is not released on failure. 698 * 699 * vfs_busy() is a custom lock, it can block the caller. 700 * vfs_busy() only sleeps if the unmount is active on the mount point. 701 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 702 * vnode belonging to mp. 703 * 704 * Lookup uses vfs_busy() to traverse mount points. 705 * root fs var fs 706 * / vnode lock A / vnode lock (/var) D 707 * /var vnode lock B /log vnode lock(/var/log) E 708 * vfs_busy lock C vfs_busy lock F 709 * 710 * Within each file system, the lock order is C->A->B and F->D->E. 711 * 712 * When traversing across mounts, the system follows that lock order: 713 * 714 * C->A->B 715 * | 716 * +->F->D->E 717 * 718 * The lookup() process for namei("/var") illustrates the process: 719 * VOP_LOOKUP() obtains B while A is held 720 * vfs_busy() obtains a shared lock on F while A and B are held 721 * vput() releases lock on B 722 * vput() releases lock on A 723 * VFS_ROOT() obtains lock on D while shared lock on F is held 724 * vfs_unbusy() releases shared lock on F 725 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 726 * Attempt to lock A (instead of vp_crossmp) while D is held would 727 * violate the global order, causing deadlocks. 728 * 729 * dounmount() locks B while F is drained. 730 */ 731 int 732 vfs_busy(struct mount *mp, int flags) 733 { 734 735 MPASS((flags & ~MBF_MASK) == 0); 736 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 737 738 if (vfs_op_thread_enter(mp)) { 739 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 740 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0); 741 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0); 742 vfs_mp_count_add_pcpu(mp, ref, 1); 743 vfs_mp_count_add_pcpu(mp, lockref, 1); 744 vfs_op_thread_exit(mp); 745 if (flags & MBF_MNTLSTLOCK) 746 mtx_unlock(&mountlist_mtx); 747 return (0); 748 } 749 750 MNT_ILOCK(mp); 751 vfs_assert_mount_counters(mp); 752 MNT_REF(mp); 753 /* 754 * If mount point is currently being unmounted, sleep until the 755 * mount point fate is decided. If thread doing the unmounting fails, 756 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 757 * that this mount point has survived the unmount attempt and vfs_busy 758 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 759 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 760 * about to be really destroyed. vfs_busy needs to release its 761 * reference on the mount point in this case and return with ENOENT, 762 * telling the caller that mount mount it tried to busy is no longer 763 * valid. 764 */ 765 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 766 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 767 MNT_REL(mp); 768 MNT_IUNLOCK(mp); 769 CTR1(KTR_VFS, "%s: failed busying before sleeping", 770 __func__); 771 return (ENOENT); 772 } 773 if (flags & MBF_MNTLSTLOCK) 774 mtx_unlock(&mountlist_mtx); 775 mp->mnt_kern_flag |= MNTK_MWAIT; 776 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 777 if (flags & MBF_MNTLSTLOCK) 778 mtx_lock(&mountlist_mtx); 779 MNT_ILOCK(mp); 780 } 781 if (flags & MBF_MNTLSTLOCK) 782 mtx_unlock(&mountlist_mtx); 783 mp->mnt_lockref++; 784 MNT_IUNLOCK(mp); 785 return (0); 786 } 787 788 /* 789 * Free a busy filesystem. 790 */ 791 void 792 vfs_unbusy(struct mount *mp) 793 { 794 int c; 795 796 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 797 798 if (vfs_op_thread_enter(mp)) { 799 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 800 vfs_mp_count_sub_pcpu(mp, lockref, 1); 801 vfs_mp_count_sub_pcpu(mp, ref, 1); 802 vfs_op_thread_exit(mp); 803 return; 804 } 805 806 MNT_ILOCK(mp); 807 vfs_assert_mount_counters(mp); 808 MNT_REL(mp); 809 c = --mp->mnt_lockref; 810 if (mp->mnt_vfs_ops == 0) { 811 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 812 MNT_IUNLOCK(mp); 813 return; 814 } 815 if (c < 0) 816 vfs_dump_mount_counters(mp); 817 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 818 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 819 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 820 mp->mnt_kern_flag &= ~MNTK_DRAINING; 821 wakeup(&mp->mnt_lockref); 822 } 823 MNT_IUNLOCK(mp); 824 } 825 826 /* 827 * Lookup a mount point by filesystem identifier. 828 */ 829 struct mount * 830 vfs_getvfs(fsid_t *fsid) 831 { 832 struct mount *mp; 833 834 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 835 mtx_lock(&mountlist_mtx); 836 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 837 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 838 vfs_ref(mp); 839 mtx_unlock(&mountlist_mtx); 840 return (mp); 841 } 842 } 843 mtx_unlock(&mountlist_mtx); 844 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 845 return ((struct mount *) 0); 846 } 847 848 /* 849 * Lookup a mount point by filesystem identifier, busying it before 850 * returning. 851 * 852 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 853 * cache for popular filesystem identifiers. The cache is lockess, using 854 * the fact that struct mount's are never freed. In worst case we may 855 * get pointer to unmounted or even different filesystem, so we have to 856 * check what we got, and go slow way if so. 857 */ 858 struct mount * 859 vfs_busyfs(fsid_t *fsid) 860 { 861 #define FSID_CACHE_SIZE 256 862 typedef struct mount * volatile vmp_t; 863 static vmp_t cache[FSID_CACHE_SIZE]; 864 struct mount *mp; 865 int error; 866 uint32_t hash; 867 868 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 869 hash = fsid->val[0] ^ fsid->val[1]; 870 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 871 mp = cache[hash]; 872 if (mp == NULL || fsidcmp(&mp->mnt_stat.f_fsid, fsid) != 0) 873 goto slow; 874 if (vfs_busy(mp, 0) != 0) { 875 cache[hash] = NULL; 876 goto slow; 877 } 878 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) 879 return (mp); 880 else 881 vfs_unbusy(mp); 882 883 slow: 884 mtx_lock(&mountlist_mtx); 885 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 886 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 887 error = vfs_busy(mp, MBF_MNTLSTLOCK); 888 if (error) { 889 cache[hash] = NULL; 890 mtx_unlock(&mountlist_mtx); 891 return (NULL); 892 } 893 cache[hash] = mp; 894 return (mp); 895 } 896 } 897 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 898 mtx_unlock(&mountlist_mtx); 899 return ((struct mount *) 0); 900 } 901 902 /* 903 * Check if a user can access privileged mount options. 904 */ 905 int 906 vfs_suser(struct mount *mp, struct thread *td) 907 { 908 int error; 909 910 if (jailed(td->td_ucred)) { 911 /* 912 * If the jail of the calling thread lacks permission for 913 * this type of file system, deny immediately. 914 */ 915 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 916 return (EPERM); 917 918 /* 919 * If the file system was mounted outside the jail of the 920 * calling thread, deny immediately. 921 */ 922 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 923 return (EPERM); 924 } 925 926 /* 927 * If file system supports delegated administration, we don't check 928 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 929 * by the file system itself. 930 * If this is not the user that did original mount, we check for 931 * the PRIV_VFS_MOUNT_OWNER privilege. 932 */ 933 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 934 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 935 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 936 return (error); 937 } 938 return (0); 939 } 940 941 /* 942 * Get a new unique fsid. Try to make its val[0] unique, since this value 943 * will be used to create fake device numbers for stat(). Also try (but 944 * not so hard) make its val[0] unique mod 2^16, since some emulators only 945 * support 16-bit device numbers. We end up with unique val[0]'s for the 946 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 947 * 948 * Keep in mind that several mounts may be running in parallel. Starting 949 * the search one past where the previous search terminated is both a 950 * micro-optimization and a defense against returning the same fsid to 951 * different mounts. 952 */ 953 void 954 vfs_getnewfsid(struct mount *mp) 955 { 956 static uint16_t mntid_base; 957 struct mount *nmp; 958 fsid_t tfsid; 959 int mtype; 960 961 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 962 mtx_lock(&mntid_mtx); 963 mtype = mp->mnt_vfc->vfc_typenum; 964 tfsid.val[1] = mtype; 965 mtype = (mtype & 0xFF) << 24; 966 for (;;) { 967 tfsid.val[0] = makedev(255, 968 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 969 mntid_base++; 970 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 971 break; 972 vfs_rel(nmp); 973 } 974 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 975 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 976 mtx_unlock(&mntid_mtx); 977 } 978 979 /* 980 * Knob to control the precision of file timestamps: 981 * 982 * 0 = seconds only; nanoseconds zeroed. 983 * 1 = seconds and nanoseconds, accurate within 1/HZ. 984 * 2 = seconds and nanoseconds, truncated to microseconds. 985 * >=3 = seconds and nanoseconds, maximum precision. 986 */ 987 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 988 989 static int timestamp_precision = TSP_USEC; 990 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 991 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 992 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 993 "3+: sec + ns (max. precision))"); 994 995 /* 996 * Get a current timestamp. 997 */ 998 void 999 vfs_timestamp(struct timespec *tsp) 1000 { 1001 struct timeval tv; 1002 1003 switch (timestamp_precision) { 1004 case TSP_SEC: 1005 tsp->tv_sec = time_second; 1006 tsp->tv_nsec = 0; 1007 break; 1008 case TSP_HZ: 1009 getnanotime(tsp); 1010 break; 1011 case TSP_USEC: 1012 microtime(&tv); 1013 TIMEVAL_TO_TIMESPEC(&tv, tsp); 1014 break; 1015 case TSP_NSEC: 1016 default: 1017 nanotime(tsp); 1018 break; 1019 } 1020 } 1021 1022 /* 1023 * Set vnode attributes to VNOVAL 1024 */ 1025 void 1026 vattr_null(struct vattr *vap) 1027 { 1028 1029 vap->va_type = VNON; 1030 vap->va_size = VNOVAL; 1031 vap->va_bytes = VNOVAL; 1032 vap->va_mode = VNOVAL; 1033 vap->va_nlink = VNOVAL; 1034 vap->va_uid = VNOVAL; 1035 vap->va_gid = VNOVAL; 1036 vap->va_fsid = VNOVAL; 1037 vap->va_fileid = VNOVAL; 1038 vap->va_blocksize = VNOVAL; 1039 vap->va_rdev = VNOVAL; 1040 vap->va_atime.tv_sec = VNOVAL; 1041 vap->va_atime.tv_nsec = VNOVAL; 1042 vap->va_mtime.tv_sec = VNOVAL; 1043 vap->va_mtime.tv_nsec = VNOVAL; 1044 vap->va_ctime.tv_sec = VNOVAL; 1045 vap->va_ctime.tv_nsec = VNOVAL; 1046 vap->va_birthtime.tv_sec = VNOVAL; 1047 vap->va_birthtime.tv_nsec = VNOVAL; 1048 vap->va_flags = VNOVAL; 1049 vap->va_gen = VNOVAL; 1050 vap->va_vaflags = 0; 1051 } 1052 1053 /* 1054 * Try to reduce the total number of vnodes. 1055 * 1056 * This routine (and its user) are buggy in at least the following ways: 1057 * - all parameters were picked years ago when RAM sizes were significantly 1058 * smaller 1059 * - it can pick vnodes based on pages used by the vm object, but filesystems 1060 * like ZFS don't use it making the pick broken 1061 * - since ZFS has its own aging policy it gets partially combated by this one 1062 * - a dedicated method should be provided for filesystems to let them decide 1063 * whether the vnode should be recycled 1064 * 1065 * This routine is called when we have too many vnodes. It attempts 1066 * to free <count> vnodes and will potentially free vnodes that still 1067 * have VM backing store (VM backing store is typically the cause 1068 * of a vnode blowout so we want to do this). Therefore, this operation 1069 * is not considered cheap. 1070 * 1071 * A number of conditions may prevent a vnode from being reclaimed. 1072 * the buffer cache may have references on the vnode, a directory 1073 * vnode may still have references due to the namei cache representing 1074 * underlying files, or the vnode may be in active use. It is not 1075 * desirable to reuse such vnodes. These conditions may cause the 1076 * number of vnodes to reach some minimum value regardless of what 1077 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 1078 * 1079 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 1080 * entries if this argument is strue 1081 * @param trigger Only reclaim vnodes with fewer than this many resident 1082 * pages. 1083 * @param target How many vnodes to reclaim. 1084 * @return The number of vnodes that were reclaimed. 1085 */ 1086 static int 1087 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target) 1088 { 1089 struct vnode *vp, *mvp; 1090 struct mount *mp; 1091 struct vm_object *object; 1092 u_long done; 1093 bool retried; 1094 1095 mtx_assert(&vnode_list_mtx, MA_OWNED); 1096 1097 retried = false; 1098 done = 0; 1099 1100 mvp = vnode_list_reclaim_marker; 1101 restart: 1102 vp = mvp; 1103 while (done < target) { 1104 vp = TAILQ_NEXT(vp, v_vnodelist); 1105 if (__predict_false(vp == NULL)) 1106 break; 1107 1108 if (__predict_false(vp->v_type == VMARKER)) 1109 continue; 1110 1111 /* 1112 * If it's been deconstructed already, it's still 1113 * referenced, or it exceeds the trigger, skip it. 1114 * Also skip free vnodes. We are trying to make space 1115 * to expand the free list, not reduce it. 1116 */ 1117 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1118 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src))) 1119 goto next_iter; 1120 1121 if (vp->v_type == VBAD || vp->v_type == VNON) 1122 goto next_iter; 1123 1124 if (!VI_TRYLOCK(vp)) 1125 goto next_iter; 1126 1127 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1128 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1129 VN_IS_DOOMED(vp) || vp->v_type == VNON) { 1130 VI_UNLOCK(vp); 1131 goto next_iter; 1132 } 1133 1134 object = atomic_load_ptr(&vp->v_object); 1135 if (object == NULL || object->resident_page_count > trigger) { 1136 VI_UNLOCK(vp); 1137 goto next_iter; 1138 } 1139 1140 vholdl(vp); 1141 VI_UNLOCK(vp); 1142 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1143 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1144 mtx_unlock(&vnode_list_mtx); 1145 1146 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1147 vdrop(vp); 1148 goto next_iter_unlocked; 1149 } 1150 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { 1151 vdrop(vp); 1152 vn_finished_write(mp); 1153 goto next_iter_unlocked; 1154 } 1155 1156 VI_LOCK(vp); 1157 if (vp->v_usecount > 0 || 1158 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1159 (vp->v_object != NULL && 1160 vp->v_object->resident_page_count > trigger)) { 1161 VOP_UNLOCK(vp); 1162 vdropl(vp); 1163 vn_finished_write(mp); 1164 goto next_iter_unlocked; 1165 } 1166 counter_u64_add(recycles_count, 1); 1167 vgonel(vp); 1168 VOP_UNLOCK(vp); 1169 vdropl(vp); 1170 vn_finished_write(mp); 1171 done++; 1172 next_iter_unlocked: 1173 if (should_yield()) 1174 kern_yield(PRI_USER); 1175 mtx_lock(&vnode_list_mtx); 1176 goto restart; 1177 next_iter: 1178 MPASS(vp->v_type != VMARKER); 1179 if (!should_yield()) 1180 continue; 1181 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1182 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1183 mtx_unlock(&vnode_list_mtx); 1184 kern_yield(PRI_USER); 1185 mtx_lock(&vnode_list_mtx); 1186 goto restart; 1187 } 1188 if (done == 0 && !retried) { 1189 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1190 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1191 retried = true; 1192 goto restart; 1193 } 1194 return (done); 1195 } 1196 1197 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1198 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1199 0, 1200 "limit on vnode free requests per call to the vnlru_free routine"); 1201 1202 /* 1203 * Attempt to reduce the free list by the requested amount. 1204 */ 1205 static int 1206 vnlru_free_locked(int count, struct vfsops *mnt_op) 1207 { 1208 struct vnode *vp, *mvp; 1209 struct mount *mp; 1210 int ocount; 1211 1212 mtx_assert(&vnode_list_mtx, MA_OWNED); 1213 if (count > max_vnlru_free) 1214 count = max_vnlru_free; 1215 ocount = count; 1216 mvp = vnode_list_free_marker; 1217 restart: 1218 vp = mvp; 1219 while (count > 0) { 1220 vp = TAILQ_NEXT(vp, v_vnodelist); 1221 if (__predict_false(vp == NULL)) { 1222 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1223 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist); 1224 break; 1225 } 1226 if (__predict_false(vp->v_type == VMARKER)) 1227 continue; 1228 1229 /* 1230 * Don't recycle if our vnode is from different type 1231 * of mount point. Note that mp is type-safe, the 1232 * check does not reach unmapped address even if 1233 * vnode is reclaimed. 1234 * Don't recycle if we can't get the interlock without 1235 * blocking. 1236 */ 1237 if (vp->v_holdcnt > 0 || (mnt_op != NULL && (mp = vp->v_mount) != NULL && 1238 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1239 continue; 1240 } 1241 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1242 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1243 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1244 VI_UNLOCK(vp); 1245 continue; 1246 } 1247 vholdl(vp); 1248 count--; 1249 mtx_unlock(&vnode_list_mtx); 1250 VI_UNLOCK(vp); 1251 vtryrecycle(vp); 1252 vdrop(vp); 1253 mtx_lock(&vnode_list_mtx); 1254 goto restart; 1255 } 1256 return (ocount - count); 1257 } 1258 1259 void 1260 vnlru_free(int count, struct vfsops *mnt_op) 1261 { 1262 1263 mtx_lock(&vnode_list_mtx); 1264 vnlru_free_locked(count, mnt_op); 1265 mtx_unlock(&vnode_list_mtx); 1266 } 1267 1268 static void 1269 vnlru_recalc(void) 1270 { 1271 1272 mtx_assert(&vnode_list_mtx, MA_OWNED); 1273 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1274 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1275 vlowat = vhiwat / 2; 1276 } 1277 1278 /* 1279 * Attempt to recycle vnodes in a context that is always safe to block. 1280 * Calling vlrurecycle() from the bowels of filesystem code has some 1281 * interesting deadlock problems. 1282 */ 1283 static struct proc *vnlruproc; 1284 static int vnlruproc_sig; 1285 1286 /* 1287 * The main freevnodes counter is only updated when threads requeue their vnode 1288 * batches. CPUs are conditionally walked to compute a more accurate total. 1289 * 1290 * Limit how much of a slop are we willing to tolerate. Note: the actual value 1291 * at any given moment can still exceed slop, but it should not be by significant 1292 * margin in practice. 1293 */ 1294 #define VNLRU_FREEVNODES_SLOP 128 1295 1296 static u_long 1297 vnlru_read_freevnodes(void) 1298 { 1299 struct vdbatch *vd; 1300 long slop; 1301 int cpu; 1302 1303 mtx_assert(&vnode_list_mtx, MA_OWNED); 1304 if (freevnodes > freevnodes_old) 1305 slop = freevnodes - freevnodes_old; 1306 else 1307 slop = freevnodes_old - freevnodes; 1308 if (slop < VNLRU_FREEVNODES_SLOP) 1309 return (freevnodes >= 0 ? freevnodes : 0); 1310 freevnodes_old = freevnodes; 1311 CPU_FOREACH(cpu) { 1312 vd = DPCPU_ID_PTR((cpu), vd); 1313 freevnodes_old += vd->freevnodes; 1314 } 1315 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1316 } 1317 1318 static bool 1319 vnlru_under(u_long rnumvnodes, u_long limit) 1320 { 1321 u_long rfreevnodes, space; 1322 1323 if (__predict_false(rnumvnodes > desiredvnodes)) 1324 return (true); 1325 1326 space = desiredvnodes - rnumvnodes; 1327 if (space < limit) { 1328 rfreevnodes = vnlru_read_freevnodes(); 1329 if (rfreevnodes > wantfreevnodes) 1330 space += rfreevnodes - wantfreevnodes; 1331 } 1332 return (space < limit); 1333 } 1334 1335 static bool 1336 vnlru_under_unlocked(u_long rnumvnodes, u_long limit) 1337 { 1338 long rfreevnodes, space; 1339 1340 if (__predict_false(rnumvnodes > desiredvnodes)) 1341 return (true); 1342 1343 space = desiredvnodes - rnumvnodes; 1344 if (space < limit) { 1345 rfreevnodes = atomic_load_long(&freevnodes); 1346 if (rfreevnodes > wantfreevnodes) 1347 space += rfreevnodes - wantfreevnodes; 1348 } 1349 return (space < limit); 1350 } 1351 1352 static void 1353 vnlru_kick(void) 1354 { 1355 1356 mtx_assert(&vnode_list_mtx, MA_OWNED); 1357 if (vnlruproc_sig == 0) { 1358 vnlruproc_sig = 1; 1359 wakeup(vnlruproc); 1360 } 1361 } 1362 1363 static void 1364 vnlru_proc(void) 1365 { 1366 u_long rnumvnodes, rfreevnodes, target; 1367 unsigned long onumvnodes; 1368 int done, force, trigger, usevnodes; 1369 bool reclaim_nc_src, want_reread; 1370 1371 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1372 SHUTDOWN_PRI_FIRST); 1373 1374 force = 0; 1375 want_reread = false; 1376 for (;;) { 1377 kproc_suspend_check(vnlruproc); 1378 mtx_lock(&vnode_list_mtx); 1379 rnumvnodes = atomic_load_long(&numvnodes); 1380 1381 if (want_reread) { 1382 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1383 want_reread = false; 1384 } 1385 1386 /* 1387 * If numvnodes is too large (due to desiredvnodes being 1388 * adjusted using its sysctl, or emergency growth), first 1389 * try to reduce it by discarding from the free list. 1390 */ 1391 if (rnumvnodes > desiredvnodes) { 1392 vnlru_free_locked(rnumvnodes - desiredvnodes, NULL); 1393 rnumvnodes = atomic_load_long(&numvnodes); 1394 } 1395 /* 1396 * Sleep if the vnode cache is in a good state. This is 1397 * when it is not over-full and has space for about a 4% 1398 * or 9% expansion (by growing its size or inexcessively 1399 * reducing its free list). Otherwise, try to reclaim 1400 * space for a 10% expansion. 1401 */ 1402 if (vstir && force == 0) { 1403 force = 1; 1404 vstir = 0; 1405 } 1406 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1407 vnlruproc_sig = 0; 1408 wakeup(&vnlruproc_sig); 1409 msleep(vnlruproc, &vnode_list_mtx, 1410 PVFS|PDROP, "vlruwt", hz); 1411 continue; 1412 } 1413 rfreevnodes = vnlru_read_freevnodes(); 1414 1415 onumvnodes = rnumvnodes; 1416 /* 1417 * Calculate parameters for recycling. These are the same 1418 * throughout the loop to give some semblance of fairness. 1419 * The trigger point is to avoid recycling vnodes with lots 1420 * of resident pages. We aren't trying to free memory; we 1421 * are trying to recycle or at least free vnodes. 1422 */ 1423 if (rnumvnodes <= desiredvnodes) 1424 usevnodes = rnumvnodes - rfreevnodes; 1425 else 1426 usevnodes = rnumvnodes; 1427 if (usevnodes <= 0) 1428 usevnodes = 1; 1429 /* 1430 * The trigger value is is chosen to give a conservatively 1431 * large value to ensure that it alone doesn't prevent 1432 * making progress. The value can easily be so large that 1433 * it is effectively infinite in some congested and 1434 * misconfigured cases, and this is necessary. Normally 1435 * it is about 8 to 100 (pages), which is quite large. 1436 */ 1437 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1438 if (force < 2) 1439 trigger = vsmalltrigger; 1440 reclaim_nc_src = force >= 3; 1441 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1442 target = target / 10 + 1; 1443 done = vlrureclaim(reclaim_nc_src, trigger, target); 1444 mtx_unlock(&vnode_list_mtx); 1445 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1446 uma_reclaim(UMA_RECLAIM_DRAIN); 1447 if (done == 0) { 1448 if (force == 0 || force == 1) { 1449 force = 2; 1450 continue; 1451 } 1452 if (force == 2) { 1453 force = 3; 1454 continue; 1455 } 1456 want_reread = true; 1457 force = 0; 1458 vnlru_nowhere++; 1459 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1460 } else { 1461 want_reread = true; 1462 kern_yield(PRI_USER); 1463 } 1464 } 1465 } 1466 1467 static struct kproc_desc vnlru_kp = { 1468 "vnlru", 1469 vnlru_proc, 1470 &vnlruproc 1471 }; 1472 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1473 &vnlru_kp); 1474 1475 /* 1476 * Routines having to do with the management of the vnode table. 1477 */ 1478 1479 /* 1480 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1481 * before we actually vgone(). This function must be called with the vnode 1482 * held to prevent the vnode from being returned to the free list midway 1483 * through vgone(). 1484 */ 1485 static int 1486 vtryrecycle(struct vnode *vp) 1487 { 1488 struct mount *vnmp; 1489 1490 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1491 VNASSERT(vp->v_holdcnt, vp, 1492 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1493 /* 1494 * This vnode may found and locked via some other list, if so we 1495 * can't recycle it yet. 1496 */ 1497 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1498 CTR2(KTR_VFS, 1499 "%s: impossible to recycle, vp %p lock is already held", 1500 __func__, vp); 1501 return (EWOULDBLOCK); 1502 } 1503 /* 1504 * Don't recycle if its filesystem is being suspended. 1505 */ 1506 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1507 VOP_UNLOCK(vp); 1508 CTR2(KTR_VFS, 1509 "%s: impossible to recycle, cannot start the write for %p", 1510 __func__, vp); 1511 return (EBUSY); 1512 } 1513 /* 1514 * If we got this far, we need to acquire the interlock and see if 1515 * anyone picked up this vnode from another list. If not, we will 1516 * mark it with DOOMED via vgonel() so that anyone who does find it 1517 * will skip over it. 1518 */ 1519 VI_LOCK(vp); 1520 if (vp->v_usecount) { 1521 VOP_UNLOCK(vp); 1522 VI_UNLOCK(vp); 1523 vn_finished_write(vnmp); 1524 CTR2(KTR_VFS, 1525 "%s: impossible to recycle, %p is already referenced", 1526 __func__, vp); 1527 return (EBUSY); 1528 } 1529 if (!VN_IS_DOOMED(vp)) { 1530 counter_u64_add(recycles_free_count, 1); 1531 vgonel(vp); 1532 } 1533 VOP_UNLOCK(vp); 1534 VI_UNLOCK(vp); 1535 vn_finished_write(vnmp); 1536 return (0); 1537 } 1538 1539 /* 1540 * Allocate a new vnode. 1541 * 1542 * The operation never returns an error. Returning an error was disabled 1543 * in r145385 (dated 2005) with the following comment: 1544 * 1545 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1546 * 1547 * Given the age of this commit (almost 15 years at the time of writing this 1548 * comment) restoring the ability to fail requires a significant audit of 1549 * all codepaths. 1550 * 1551 * The routine can try to free a vnode or stall for up to 1 second waiting for 1552 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1553 */ 1554 static u_long vn_alloc_cyclecount; 1555 1556 static struct vnode * __noinline 1557 vn_alloc_hard(struct mount *mp) 1558 { 1559 u_long rnumvnodes, rfreevnodes; 1560 1561 mtx_lock(&vnode_list_mtx); 1562 rnumvnodes = atomic_load_long(&numvnodes); 1563 if (rnumvnodes + 1 < desiredvnodes) { 1564 vn_alloc_cyclecount = 0; 1565 goto alloc; 1566 } 1567 rfreevnodes = vnlru_read_freevnodes(); 1568 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1569 vn_alloc_cyclecount = 0; 1570 vstir = 1; 1571 } 1572 /* 1573 * Grow the vnode cache if it will not be above its target max 1574 * after growing. Otherwise, if the free list is nonempty, try 1575 * to reclaim 1 item from it before growing the cache (possibly 1576 * above its target max if the reclamation failed or is delayed). 1577 * Otherwise, wait for some space. In all cases, schedule 1578 * vnlru_proc() if we are getting short of space. The watermarks 1579 * should be chosen so that we never wait or even reclaim from 1580 * the free list to below its target minimum. 1581 */ 1582 if (vnlru_free_locked(1, NULL) > 0) 1583 goto alloc; 1584 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1585 /* 1586 * Wait for space for a new vnode. 1587 */ 1588 vnlru_kick(); 1589 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1590 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1591 vnlru_read_freevnodes() > 1) 1592 vnlru_free_locked(1, NULL); 1593 } 1594 alloc: 1595 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1596 if (vnlru_under(rnumvnodes, vlowat)) 1597 vnlru_kick(); 1598 mtx_unlock(&vnode_list_mtx); 1599 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 1600 } 1601 1602 static struct vnode * 1603 vn_alloc(struct mount *mp) 1604 { 1605 u_long rnumvnodes; 1606 1607 if (__predict_false(vn_alloc_cyclecount != 0)) 1608 return (vn_alloc_hard(mp)); 1609 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1610 if (__predict_false(vnlru_under_unlocked(rnumvnodes, vlowat))) { 1611 atomic_subtract_long(&numvnodes, 1); 1612 return (vn_alloc_hard(mp)); 1613 } 1614 1615 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 1616 } 1617 1618 static void 1619 vn_free(struct vnode *vp) 1620 { 1621 1622 atomic_subtract_long(&numvnodes, 1); 1623 uma_zfree_smr(vnode_zone, vp); 1624 } 1625 1626 /* 1627 * Return the next vnode from the free list. 1628 */ 1629 int 1630 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1631 struct vnode **vpp) 1632 { 1633 struct vnode *vp; 1634 struct thread *td; 1635 struct lock_object *lo; 1636 1637 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1638 1639 KASSERT(vops->registered, 1640 ("%s: not registered vector op %p\n", __func__, vops)); 1641 1642 td = curthread; 1643 if (td->td_vp_reserved != NULL) { 1644 vp = td->td_vp_reserved; 1645 td->td_vp_reserved = NULL; 1646 } else { 1647 vp = vn_alloc(mp); 1648 } 1649 counter_u64_add(vnodes_created, 1); 1650 /* 1651 * Locks are given the generic name "vnode" when created. 1652 * Follow the historic practice of using the filesystem 1653 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1654 * 1655 * Locks live in a witness group keyed on their name. Thus, 1656 * when a lock is renamed, it must also move from the witness 1657 * group of its old name to the witness group of its new name. 1658 * 1659 * The change only needs to be made when the vnode moves 1660 * from one filesystem type to another. We ensure that each 1661 * filesystem use a single static name pointer for its tag so 1662 * that we can compare pointers rather than doing a strcmp(). 1663 */ 1664 lo = &vp->v_vnlock->lock_object; 1665 #ifdef WITNESS 1666 if (lo->lo_name != tag) { 1667 #endif 1668 lo->lo_name = tag; 1669 #ifdef WITNESS 1670 WITNESS_DESTROY(lo); 1671 WITNESS_INIT(lo, tag); 1672 } 1673 #endif 1674 /* 1675 * By default, don't allow shared locks unless filesystems opt-in. 1676 */ 1677 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1678 /* 1679 * Finalize various vnode identity bits. 1680 */ 1681 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1682 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1683 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1684 vp->v_type = VNON; 1685 vp->v_op = vops; 1686 v_init_counters(vp); 1687 vp->v_bufobj.bo_ops = &buf_ops_bio; 1688 #ifdef DIAGNOSTIC 1689 if (mp == NULL && vops != &dead_vnodeops) 1690 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1691 #endif 1692 #ifdef MAC 1693 mac_vnode_init(vp); 1694 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1695 mac_vnode_associate_singlelabel(mp, vp); 1696 #endif 1697 if (mp != NULL) { 1698 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1699 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1700 vp->v_vflag |= VV_NOKNOTE; 1701 } 1702 1703 /* 1704 * For the filesystems which do not use vfs_hash_insert(), 1705 * still initialize v_hash to have vfs_hash_index() useful. 1706 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1707 * its own hashing. 1708 */ 1709 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1710 1711 *vpp = vp; 1712 return (0); 1713 } 1714 1715 void 1716 getnewvnode_reserve(void) 1717 { 1718 struct thread *td; 1719 1720 td = curthread; 1721 MPASS(td->td_vp_reserved == NULL); 1722 td->td_vp_reserved = vn_alloc(NULL); 1723 } 1724 1725 void 1726 getnewvnode_drop_reserve(void) 1727 { 1728 struct thread *td; 1729 1730 td = curthread; 1731 if (td->td_vp_reserved != NULL) { 1732 vn_free(td->td_vp_reserved); 1733 td->td_vp_reserved = NULL; 1734 } 1735 } 1736 1737 static void 1738 freevnode(struct vnode *vp) 1739 { 1740 struct bufobj *bo; 1741 1742 /* 1743 * The vnode has been marked for destruction, so free it. 1744 * 1745 * The vnode will be returned to the zone where it will 1746 * normally remain until it is needed for another vnode. We 1747 * need to cleanup (or verify that the cleanup has already 1748 * been done) any residual data left from its current use 1749 * so as not to contaminate the freshly allocated vnode. 1750 */ 1751 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1752 /* 1753 * Paired with vgone. 1754 */ 1755 vn_seqc_write_end_locked(vp); 1756 VNPASS(vp->v_seqc_users == 0, vp); 1757 1758 bo = &vp->v_bufobj; 1759 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1760 VNPASS(vp->v_holdcnt == VHOLD_NO_SMR, vp); 1761 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1762 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1763 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1764 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1765 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1766 ("clean blk trie not empty")); 1767 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1768 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1769 ("dirty blk trie not empty")); 1770 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1771 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1772 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1773 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1774 ("Dangling rangelock waiters")); 1775 VI_UNLOCK(vp); 1776 #ifdef MAC 1777 mac_vnode_destroy(vp); 1778 #endif 1779 if (vp->v_pollinfo != NULL) { 1780 destroy_vpollinfo(vp->v_pollinfo); 1781 vp->v_pollinfo = NULL; 1782 } 1783 #ifdef INVARIANTS 1784 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1785 vp->v_op = NULL; 1786 #endif 1787 vp->v_mountedhere = NULL; 1788 vp->v_unpcb = NULL; 1789 vp->v_rdev = NULL; 1790 vp->v_fifoinfo = NULL; 1791 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1792 vp->v_irflag = 0; 1793 vp->v_iflag = 0; 1794 vp->v_vflag = 0; 1795 bo->bo_flag = 0; 1796 vn_free(vp); 1797 } 1798 1799 /* 1800 * Delete from old mount point vnode list, if on one. 1801 */ 1802 static void 1803 delmntque(struct vnode *vp) 1804 { 1805 struct mount *mp; 1806 1807 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 1808 1809 mp = vp->v_mount; 1810 if (mp == NULL) 1811 return; 1812 MNT_ILOCK(mp); 1813 VI_LOCK(vp); 1814 vp->v_mount = NULL; 1815 VI_UNLOCK(vp); 1816 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1817 ("bad mount point vnode list size")); 1818 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1819 mp->mnt_nvnodelistsize--; 1820 MNT_REL(mp); 1821 MNT_IUNLOCK(mp); 1822 } 1823 1824 static void 1825 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1826 { 1827 1828 vp->v_data = NULL; 1829 vp->v_op = &dead_vnodeops; 1830 vgone(vp); 1831 vput(vp); 1832 } 1833 1834 /* 1835 * Insert into list of vnodes for the new mount point, if available. 1836 */ 1837 int 1838 insmntque1(struct vnode *vp, struct mount *mp, 1839 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1840 { 1841 1842 KASSERT(vp->v_mount == NULL, 1843 ("insmntque: vnode already on per mount vnode list")); 1844 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1845 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1846 1847 /* 1848 * We acquire the vnode interlock early to ensure that the 1849 * vnode cannot be recycled by another process releasing a 1850 * holdcnt on it before we get it on both the vnode list 1851 * and the active vnode list. The mount mutex protects only 1852 * manipulation of the vnode list and the vnode freelist 1853 * mutex protects only manipulation of the active vnode list. 1854 * Hence the need to hold the vnode interlock throughout. 1855 */ 1856 MNT_ILOCK(mp); 1857 VI_LOCK(vp); 1858 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1859 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1860 mp->mnt_nvnodelistsize == 0)) && 1861 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1862 VI_UNLOCK(vp); 1863 MNT_IUNLOCK(mp); 1864 if (dtr != NULL) 1865 dtr(vp, dtr_arg); 1866 return (EBUSY); 1867 } 1868 vp->v_mount = mp; 1869 MNT_REF(mp); 1870 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1871 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1872 ("neg mount point vnode list size")); 1873 mp->mnt_nvnodelistsize++; 1874 VI_UNLOCK(vp); 1875 MNT_IUNLOCK(mp); 1876 return (0); 1877 } 1878 1879 int 1880 insmntque(struct vnode *vp, struct mount *mp) 1881 { 1882 1883 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1884 } 1885 1886 /* 1887 * Flush out and invalidate all buffers associated with a bufobj 1888 * Called with the underlying object locked. 1889 */ 1890 int 1891 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1892 { 1893 int error; 1894 1895 BO_LOCK(bo); 1896 if (flags & V_SAVE) { 1897 error = bufobj_wwait(bo, slpflag, slptimeo); 1898 if (error) { 1899 BO_UNLOCK(bo); 1900 return (error); 1901 } 1902 if (bo->bo_dirty.bv_cnt > 0) { 1903 BO_UNLOCK(bo); 1904 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1905 return (error); 1906 /* 1907 * XXX We could save a lock/unlock if this was only 1908 * enabled under INVARIANTS 1909 */ 1910 BO_LOCK(bo); 1911 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1912 panic("vinvalbuf: dirty bufs"); 1913 } 1914 } 1915 /* 1916 * If you alter this loop please notice that interlock is dropped and 1917 * reacquired in flushbuflist. Special care is needed to ensure that 1918 * no race conditions occur from this. 1919 */ 1920 do { 1921 error = flushbuflist(&bo->bo_clean, 1922 flags, bo, slpflag, slptimeo); 1923 if (error == 0 && !(flags & V_CLEANONLY)) 1924 error = flushbuflist(&bo->bo_dirty, 1925 flags, bo, slpflag, slptimeo); 1926 if (error != 0 && error != EAGAIN) { 1927 BO_UNLOCK(bo); 1928 return (error); 1929 } 1930 } while (error != 0); 1931 1932 /* 1933 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1934 * have write I/O in-progress but if there is a VM object then the 1935 * VM object can also have read-I/O in-progress. 1936 */ 1937 do { 1938 bufobj_wwait(bo, 0, 0); 1939 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1940 BO_UNLOCK(bo); 1941 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1942 BO_LOCK(bo); 1943 } 1944 } while (bo->bo_numoutput > 0); 1945 BO_UNLOCK(bo); 1946 1947 /* 1948 * Destroy the copy in the VM cache, too. 1949 */ 1950 if (bo->bo_object != NULL && 1951 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1952 VM_OBJECT_WLOCK(bo->bo_object); 1953 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1954 OBJPR_CLEANONLY : 0); 1955 VM_OBJECT_WUNLOCK(bo->bo_object); 1956 } 1957 1958 #ifdef INVARIANTS 1959 BO_LOCK(bo); 1960 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1961 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1962 bo->bo_clean.bv_cnt > 0)) 1963 panic("vinvalbuf: flush failed"); 1964 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1965 bo->bo_dirty.bv_cnt > 0) 1966 panic("vinvalbuf: flush dirty failed"); 1967 BO_UNLOCK(bo); 1968 #endif 1969 return (0); 1970 } 1971 1972 /* 1973 * Flush out and invalidate all buffers associated with a vnode. 1974 * Called with the underlying object locked. 1975 */ 1976 int 1977 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1978 { 1979 1980 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1981 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1982 if (vp->v_object != NULL && vp->v_object->handle != vp) 1983 return (0); 1984 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1985 } 1986 1987 /* 1988 * Flush out buffers on the specified list. 1989 * 1990 */ 1991 static int 1992 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1993 int slptimeo) 1994 { 1995 struct buf *bp, *nbp; 1996 int retval, error; 1997 daddr_t lblkno; 1998 b_xflags_t xflags; 1999 2000 ASSERT_BO_WLOCKED(bo); 2001 2002 retval = 0; 2003 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2004 /* 2005 * If we are flushing both V_NORMAL and V_ALT buffers then 2006 * do not skip any buffers. If we are flushing only V_NORMAL 2007 * buffers then skip buffers marked as BX_ALTDATA. If we are 2008 * flushing only V_ALT buffers then skip buffers not marked 2009 * as BX_ALTDATA. 2010 */ 2011 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2012 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2013 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2014 continue; 2015 } 2016 if (nbp != NULL) { 2017 lblkno = nbp->b_lblkno; 2018 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2019 } 2020 retval = EAGAIN; 2021 error = BUF_TIMELOCK(bp, 2022 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2023 "flushbuf", slpflag, slptimeo); 2024 if (error) { 2025 BO_LOCK(bo); 2026 return (error != ENOLCK ? error : EAGAIN); 2027 } 2028 KASSERT(bp->b_bufobj == bo, 2029 ("bp %p wrong b_bufobj %p should be %p", 2030 bp, bp->b_bufobj, bo)); 2031 /* 2032 * XXX Since there are no node locks for NFS, I 2033 * believe there is a slight chance that a delayed 2034 * write will occur while sleeping just above, so 2035 * check for it. 2036 */ 2037 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2038 (flags & V_SAVE)) { 2039 bremfree(bp); 2040 bp->b_flags |= B_ASYNC; 2041 bwrite(bp); 2042 BO_LOCK(bo); 2043 return (EAGAIN); /* XXX: why not loop ? */ 2044 } 2045 bremfree(bp); 2046 bp->b_flags |= (B_INVAL | B_RELBUF); 2047 bp->b_flags &= ~B_ASYNC; 2048 brelse(bp); 2049 BO_LOCK(bo); 2050 if (nbp == NULL) 2051 break; 2052 nbp = gbincore(bo, lblkno); 2053 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2054 != xflags) 2055 break; /* nbp invalid */ 2056 } 2057 return (retval); 2058 } 2059 2060 int 2061 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2062 { 2063 struct buf *bp; 2064 int error; 2065 daddr_t lblkno; 2066 2067 ASSERT_BO_LOCKED(bo); 2068 2069 for (lblkno = startn;;) { 2070 again: 2071 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2072 if (bp == NULL || bp->b_lblkno >= endn || 2073 bp->b_lblkno < startn) 2074 break; 2075 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2076 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2077 if (error != 0) { 2078 BO_RLOCK(bo); 2079 if (error == ENOLCK) 2080 goto again; 2081 return (error); 2082 } 2083 KASSERT(bp->b_bufobj == bo, 2084 ("bp %p wrong b_bufobj %p should be %p", 2085 bp, bp->b_bufobj, bo)); 2086 lblkno = bp->b_lblkno + 1; 2087 if ((bp->b_flags & B_MANAGED) == 0) 2088 bremfree(bp); 2089 bp->b_flags |= B_RELBUF; 2090 /* 2091 * In the VMIO case, use the B_NOREUSE flag to hint that the 2092 * pages backing each buffer in the range are unlikely to be 2093 * reused. Dirty buffers will have the hint applied once 2094 * they've been written. 2095 */ 2096 if ((bp->b_flags & B_VMIO) != 0) 2097 bp->b_flags |= B_NOREUSE; 2098 brelse(bp); 2099 BO_RLOCK(bo); 2100 } 2101 return (0); 2102 } 2103 2104 /* 2105 * Truncate a file's buffer and pages to a specified length. This 2106 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2107 * sync activity. 2108 */ 2109 int 2110 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2111 { 2112 struct buf *bp, *nbp; 2113 struct bufobj *bo; 2114 daddr_t startlbn; 2115 2116 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2117 vp, blksize, (uintmax_t)length); 2118 2119 /* 2120 * Round up to the *next* lbn. 2121 */ 2122 startlbn = howmany(length, blksize); 2123 2124 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2125 2126 bo = &vp->v_bufobj; 2127 restart_unlocked: 2128 BO_LOCK(bo); 2129 2130 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2131 ; 2132 2133 if (length > 0) { 2134 restartsync: 2135 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2136 if (bp->b_lblkno > 0) 2137 continue; 2138 /* 2139 * Since we hold the vnode lock this should only 2140 * fail if we're racing with the buf daemon. 2141 */ 2142 if (BUF_LOCK(bp, 2143 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2144 BO_LOCKPTR(bo)) == ENOLCK) 2145 goto restart_unlocked; 2146 2147 VNASSERT((bp->b_flags & B_DELWRI), vp, 2148 ("buf(%p) on dirty queue without DELWRI", bp)); 2149 2150 bremfree(bp); 2151 bawrite(bp); 2152 BO_LOCK(bo); 2153 goto restartsync; 2154 } 2155 } 2156 2157 bufobj_wwait(bo, 0, 0); 2158 BO_UNLOCK(bo); 2159 vnode_pager_setsize(vp, length); 2160 2161 return (0); 2162 } 2163 2164 /* 2165 * Invalidate the cached pages of a file's buffer within the range of block 2166 * numbers [startlbn, endlbn). 2167 */ 2168 void 2169 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2170 int blksize) 2171 { 2172 struct bufobj *bo; 2173 off_t start, end; 2174 2175 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2176 2177 start = blksize * startlbn; 2178 end = blksize * endlbn; 2179 2180 bo = &vp->v_bufobj; 2181 BO_LOCK(bo); 2182 MPASS(blksize == bo->bo_bsize); 2183 2184 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2185 ; 2186 2187 BO_UNLOCK(bo); 2188 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2189 } 2190 2191 static int 2192 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2193 daddr_t startlbn, daddr_t endlbn) 2194 { 2195 struct buf *bp, *nbp; 2196 bool anyfreed; 2197 2198 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2199 ASSERT_BO_LOCKED(bo); 2200 2201 do { 2202 anyfreed = false; 2203 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2204 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2205 continue; 2206 if (BUF_LOCK(bp, 2207 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2208 BO_LOCKPTR(bo)) == ENOLCK) { 2209 BO_LOCK(bo); 2210 return (EAGAIN); 2211 } 2212 2213 bremfree(bp); 2214 bp->b_flags |= B_INVAL | B_RELBUF; 2215 bp->b_flags &= ~B_ASYNC; 2216 brelse(bp); 2217 anyfreed = true; 2218 2219 BO_LOCK(bo); 2220 if (nbp != NULL && 2221 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2222 nbp->b_vp != vp || 2223 (nbp->b_flags & B_DELWRI) != 0)) 2224 return (EAGAIN); 2225 } 2226 2227 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2228 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2229 continue; 2230 if (BUF_LOCK(bp, 2231 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2232 BO_LOCKPTR(bo)) == ENOLCK) { 2233 BO_LOCK(bo); 2234 return (EAGAIN); 2235 } 2236 bremfree(bp); 2237 bp->b_flags |= B_INVAL | B_RELBUF; 2238 bp->b_flags &= ~B_ASYNC; 2239 brelse(bp); 2240 anyfreed = true; 2241 2242 BO_LOCK(bo); 2243 if (nbp != NULL && 2244 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2245 (nbp->b_vp != vp) || 2246 (nbp->b_flags & B_DELWRI) == 0)) 2247 return (EAGAIN); 2248 } 2249 } while (anyfreed); 2250 return (0); 2251 } 2252 2253 static void 2254 buf_vlist_remove(struct buf *bp) 2255 { 2256 struct bufv *bv; 2257 b_xflags_t flags; 2258 2259 flags = bp->b_xflags; 2260 2261 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2262 ASSERT_BO_WLOCKED(bp->b_bufobj); 2263 KASSERT((flags & (BX_VNDIRTY | BX_VNCLEAN)) != 0 && 2264 (flags & (BX_VNDIRTY | BX_VNCLEAN)) != (BX_VNDIRTY | BX_VNCLEAN), 2265 ("%s: buffer %p has invalid queue state", __func__, bp)); 2266 2267 if ((flags & BX_VNDIRTY) != 0) 2268 bv = &bp->b_bufobj->bo_dirty; 2269 else 2270 bv = &bp->b_bufobj->bo_clean; 2271 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2272 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2273 bv->bv_cnt--; 2274 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2275 } 2276 2277 /* 2278 * Add the buffer to the sorted clean or dirty block list. 2279 * 2280 * NOTE: xflags is passed as a constant, optimizing this inline function! 2281 */ 2282 static void 2283 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2284 { 2285 struct bufv *bv; 2286 struct buf *n; 2287 int error; 2288 2289 ASSERT_BO_WLOCKED(bo); 2290 KASSERT((bo->bo_flag & BO_NOBUFS) == 0, 2291 ("buf_vlist_add: bo %p does not allow bufs", bo)); 2292 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2293 ("dead bo %p", bo)); 2294 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2295 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2296 bp->b_xflags |= xflags; 2297 if (xflags & BX_VNDIRTY) 2298 bv = &bo->bo_dirty; 2299 else 2300 bv = &bo->bo_clean; 2301 2302 /* 2303 * Keep the list ordered. Optimize empty list insertion. Assume 2304 * we tend to grow at the tail so lookup_le should usually be cheaper 2305 * than _ge. 2306 */ 2307 if (bv->bv_cnt == 0 || 2308 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2309 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2310 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2311 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2312 else 2313 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2314 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2315 if (error) 2316 panic("buf_vlist_add: Preallocated nodes insufficient."); 2317 bv->bv_cnt++; 2318 } 2319 2320 /* 2321 * Look up a buffer using the buffer tries. 2322 */ 2323 struct buf * 2324 gbincore(struct bufobj *bo, daddr_t lblkno) 2325 { 2326 struct buf *bp; 2327 2328 ASSERT_BO_LOCKED(bo); 2329 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2330 if (bp != NULL) 2331 return (bp); 2332 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno)); 2333 } 2334 2335 /* 2336 * Look up a buf using the buffer tries, without the bufobj lock. This relies 2337 * on SMR for safe lookup, and bufs being in a no-free zone to provide type 2338 * stability of the result. Like other lockless lookups, the found buf may 2339 * already be invalid by the time this function returns. 2340 */ 2341 struct buf * 2342 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno) 2343 { 2344 struct buf *bp; 2345 2346 ASSERT_BO_UNLOCKED(bo); 2347 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno); 2348 if (bp != NULL) 2349 return (bp); 2350 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno)); 2351 } 2352 2353 /* 2354 * Associate a buffer with a vnode. 2355 */ 2356 void 2357 bgetvp(struct vnode *vp, struct buf *bp) 2358 { 2359 struct bufobj *bo; 2360 2361 bo = &vp->v_bufobj; 2362 ASSERT_BO_WLOCKED(bo); 2363 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2364 2365 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2366 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2367 ("bgetvp: bp already attached! %p", bp)); 2368 2369 vhold(vp); 2370 bp->b_vp = vp; 2371 bp->b_bufobj = bo; 2372 /* 2373 * Insert onto list for new vnode. 2374 */ 2375 buf_vlist_add(bp, bo, BX_VNCLEAN); 2376 } 2377 2378 /* 2379 * Disassociate a buffer from a vnode. 2380 */ 2381 void 2382 brelvp(struct buf *bp) 2383 { 2384 struct bufobj *bo; 2385 struct vnode *vp; 2386 2387 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2388 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2389 2390 /* 2391 * Delete from old vnode list, if on one. 2392 */ 2393 vp = bp->b_vp; /* XXX */ 2394 bo = bp->b_bufobj; 2395 BO_LOCK(bo); 2396 buf_vlist_remove(bp); 2397 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2398 bo->bo_flag &= ~BO_ONWORKLST; 2399 mtx_lock(&sync_mtx); 2400 LIST_REMOVE(bo, bo_synclist); 2401 syncer_worklist_len--; 2402 mtx_unlock(&sync_mtx); 2403 } 2404 bp->b_vp = NULL; 2405 bp->b_bufobj = NULL; 2406 BO_UNLOCK(bo); 2407 vdrop(vp); 2408 } 2409 2410 /* 2411 * Add an item to the syncer work queue. 2412 */ 2413 static void 2414 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2415 { 2416 int slot; 2417 2418 ASSERT_BO_WLOCKED(bo); 2419 2420 mtx_lock(&sync_mtx); 2421 if (bo->bo_flag & BO_ONWORKLST) 2422 LIST_REMOVE(bo, bo_synclist); 2423 else { 2424 bo->bo_flag |= BO_ONWORKLST; 2425 syncer_worklist_len++; 2426 } 2427 2428 if (delay > syncer_maxdelay - 2) 2429 delay = syncer_maxdelay - 2; 2430 slot = (syncer_delayno + delay) & syncer_mask; 2431 2432 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2433 mtx_unlock(&sync_mtx); 2434 } 2435 2436 static int 2437 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2438 { 2439 int error, len; 2440 2441 mtx_lock(&sync_mtx); 2442 len = syncer_worklist_len - sync_vnode_count; 2443 mtx_unlock(&sync_mtx); 2444 error = SYSCTL_OUT(req, &len, sizeof(len)); 2445 return (error); 2446 } 2447 2448 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2449 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2450 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2451 2452 static struct proc *updateproc; 2453 static void sched_sync(void); 2454 static struct kproc_desc up_kp = { 2455 "syncer", 2456 sched_sync, 2457 &updateproc 2458 }; 2459 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2460 2461 static int 2462 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2463 { 2464 struct vnode *vp; 2465 struct mount *mp; 2466 2467 *bo = LIST_FIRST(slp); 2468 if (*bo == NULL) 2469 return (0); 2470 vp = bo2vnode(*bo); 2471 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2472 return (1); 2473 /* 2474 * We use vhold in case the vnode does not 2475 * successfully sync. vhold prevents the vnode from 2476 * going away when we unlock the sync_mtx so that 2477 * we can acquire the vnode interlock. 2478 */ 2479 vholdl(vp); 2480 mtx_unlock(&sync_mtx); 2481 VI_UNLOCK(vp); 2482 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2483 vdrop(vp); 2484 mtx_lock(&sync_mtx); 2485 return (*bo == LIST_FIRST(slp)); 2486 } 2487 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2488 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2489 VOP_UNLOCK(vp); 2490 vn_finished_write(mp); 2491 BO_LOCK(*bo); 2492 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2493 /* 2494 * Put us back on the worklist. The worklist 2495 * routine will remove us from our current 2496 * position and then add us back in at a later 2497 * position. 2498 */ 2499 vn_syncer_add_to_worklist(*bo, syncdelay); 2500 } 2501 BO_UNLOCK(*bo); 2502 vdrop(vp); 2503 mtx_lock(&sync_mtx); 2504 return (0); 2505 } 2506 2507 static int first_printf = 1; 2508 2509 /* 2510 * System filesystem synchronizer daemon. 2511 */ 2512 static void 2513 sched_sync(void) 2514 { 2515 struct synclist *next, *slp; 2516 struct bufobj *bo; 2517 long starttime; 2518 struct thread *td = curthread; 2519 int last_work_seen; 2520 int net_worklist_len; 2521 int syncer_final_iter; 2522 int error; 2523 2524 last_work_seen = 0; 2525 syncer_final_iter = 0; 2526 syncer_state = SYNCER_RUNNING; 2527 starttime = time_uptime; 2528 td->td_pflags |= TDP_NORUNNINGBUF; 2529 2530 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2531 SHUTDOWN_PRI_LAST); 2532 2533 mtx_lock(&sync_mtx); 2534 for (;;) { 2535 if (syncer_state == SYNCER_FINAL_DELAY && 2536 syncer_final_iter == 0) { 2537 mtx_unlock(&sync_mtx); 2538 kproc_suspend_check(td->td_proc); 2539 mtx_lock(&sync_mtx); 2540 } 2541 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2542 if (syncer_state != SYNCER_RUNNING && 2543 starttime != time_uptime) { 2544 if (first_printf) { 2545 printf("\nSyncing disks, vnodes remaining... "); 2546 first_printf = 0; 2547 } 2548 printf("%d ", net_worklist_len); 2549 } 2550 starttime = time_uptime; 2551 2552 /* 2553 * Push files whose dirty time has expired. Be careful 2554 * of interrupt race on slp queue. 2555 * 2556 * Skip over empty worklist slots when shutting down. 2557 */ 2558 do { 2559 slp = &syncer_workitem_pending[syncer_delayno]; 2560 syncer_delayno += 1; 2561 if (syncer_delayno == syncer_maxdelay) 2562 syncer_delayno = 0; 2563 next = &syncer_workitem_pending[syncer_delayno]; 2564 /* 2565 * If the worklist has wrapped since the 2566 * it was emptied of all but syncer vnodes, 2567 * switch to the FINAL_DELAY state and run 2568 * for one more second. 2569 */ 2570 if (syncer_state == SYNCER_SHUTTING_DOWN && 2571 net_worklist_len == 0 && 2572 last_work_seen == syncer_delayno) { 2573 syncer_state = SYNCER_FINAL_DELAY; 2574 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2575 } 2576 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2577 syncer_worklist_len > 0); 2578 2579 /* 2580 * Keep track of the last time there was anything 2581 * on the worklist other than syncer vnodes. 2582 * Return to the SHUTTING_DOWN state if any 2583 * new work appears. 2584 */ 2585 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2586 last_work_seen = syncer_delayno; 2587 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2588 syncer_state = SYNCER_SHUTTING_DOWN; 2589 while (!LIST_EMPTY(slp)) { 2590 error = sync_vnode(slp, &bo, td); 2591 if (error == 1) { 2592 LIST_REMOVE(bo, bo_synclist); 2593 LIST_INSERT_HEAD(next, bo, bo_synclist); 2594 continue; 2595 } 2596 2597 if (first_printf == 0) { 2598 /* 2599 * Drop the sync mutex, because some watchdog 2600 * drivers need to sleep while patting 2601 */ 2602 mtx_unlock(&sync_mtx); 2603 wdog_kern_pat(WD_LASTVAL); 2604 mtx_lock(&sync_mtx); 2605 } 2606 2607 } 2608 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2609 syncer_final_iter--; 2610 /* 2611 * The variable rushjob allows the kernel to speed up the 2612 * processing of the filesystem syncer process. A rushjob 2613 * value of N tells the filesystem syncer to process the next 2614 * N seconds worth of work on its queue ASAP. Currently rushjob 2615 * is used by the soft update code to speed up the filesystem 2616 * syncer process when the incore state is getting so far 2617 * ahead of the disk that the kernel memory pool is being 2618 * threatened with exhaustion. 2619 */ 2620 if (rushjob > 0) { 2621 rushjob -= 1; 2622 continue; 2623 } 2624 /* 2625 * Just sleep for a short period of time between 2626 * iterations when shutting down to allow some I/O 2627 * to happen. 2628 * 2629 * If it has taken us less than a second to process the 2630 * current work, then wait. Otherwise start right over 2631 * again. We can still lose time if any single round 2632 * takes more than two seconds, but it does not really 2633 * matter as we are just trying to generally pace the 2634 * filesystem activity. 2635 */ 2636 if (syncer_state != SYNCER_RUNNING || 2637 time_uptime == starttime) { 2638 thread_lock(td); 2639 sched_prio(td, PPAUSE); 2640 thread_unlock(td); 2641 } 2642 if (syncer_state != SYNCER_RUNNING) 2643 cv_timedwait(&sync_wakeup, &sync_mtx, 2644 hz / SYNCER_SHUTDOWN_SPEEDUP); 2645 else if (time_uptime == starttime) 2646 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2647 } 2648 } 2649 2650 /* 2651 * Request the syncer daemon to speed up its work. 2652 * We never push it to speed up more than half of its 2653 * normal turn time, otherwise it could take over the cpu. 2654 */ 2655 int 2656 speedup_syncer(void) 2657 { 2658 int ret = 0; 2659 2660 mtx_lock(&sync_mtx); 2661 if (rushjob < syncdelay / 2) { 2662 rushjob += 1; 2663 stat_rush_requests += 1; 2664 ret = 1; 2665 } 2666 mtx_unlock(&sync_mtx); 2667 cv_broadcast(&sync_wakeup); 2668 return (ret); 2669 } 2670 2671 /* 2672 * Tell the syncer to speed up its work and run though its work 2673 * list several times, then tell it to shut down. 2674 */ 2675 static void 2676 syncer_shutdown(void *arg, int howto) 2677 { 2678 2679 if (howto & RB_NOSYNC) 2680 return; 2681 mtx_lock(&sync_mtx); 2682 syncer_state = SYNCER_SHUTTING_DOWN; 2683 rushjob = 0; 2684 mtx_unlock(&sync_mtx); 2685 cv_broadcast(&sync_wakeup); 2686 kproc_shutdown(arg, howto); 2687 } 2688 2689 void 2690 syncer_suspend(void) 2691 { 2692 2693 syncer_shutdown(updateproc, 0); 2694 } 2695 2696 void 2697 syncer_resume(void) 2698 { 2699 2700 mtx_lock(&sync_mtx); 2701 first_printf = 1; 2702 syncer_state = SYNCER_RUNNING; 2703 mtx_unlock(&sync_mtx); 2704 cv_broadcast(&sync_wakeup); 2705 kproc_resume(updateproc); 2706 } 2707 2708 /* 2709 * Move the buffer between the clean and dirty lists of its vnode. 2710 */ 2711 void 2712 reassignbuf(struct buf *bp) 2713 { 2714 struct vnode *vp; 2715 struct bufobj *bo; 2716 int delay; 2717 #ifdef INVARIANTS 2718 struct bufv *bv; 2719 #endif 2720 2721 vp = bp->b_vp; 2722 bo = bp->b_bufobj; 2723 2724 KASSERT((bp->b_flags & B_PAGING) == 0, 2725 ("%s: cannot reassign paging buffer %p", __func__, bp)); 2726 2727 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2728 bp, bp->b_vp, bp->b_flags); 2729 2730 BO_LOCK(bo); 2731 buf_vlist_remove(bp); 2732 2733 /* 2734 * If dirty, put on list of dirty buffers; otherwise insert onto list 2735 * of clean buffers. 2736 */ 2737 if (bp->b_flags & B_DELWRI) { 2738 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2739 switch (vp->v_type) { 2740 case VDIR: 2741 delay = dirdelay; 2742 break; 2743 case VCHR: 2744 delay = metadelay; 2745 break; 2746 default: 2747 delay = filedelay; 2748 } 2749 vn_syncer_add_to_worklist(bo, delay); 2750 } 2751 buf_vlist_add(bp, bo, BX_VNDIRTY); 2752 } else { 2753 buf_vlist_add(bp, bo, BX_VNCLEAN); 2754 2755 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2756 mtx_lock(&sync_mtx); 2757 LIST_REMOVE(bo, bo_synclist); 2758 syncer_worklist_len--; 2759 mtx_unlock(&sync_mtx); 2760 bo->bo_flag &= ~BO_ONWORKLST; 2761 } 2762 } 2763 #ifdef INVARIANTS 2764 bv = &bo->bo_clean; 2765 bp = TAILQ_FIRST(&bv->bv_hd); 2766 KASSERT(bp == NULL || bp->b_bufobj == bo, 2767 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2768 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2769 KASSERT(bp == NULL || bp->b_bufobj == bo, 2770 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2771 bv = &bo->bo_dirty; 2772 bp = TAILQ_FIRST(&bv->bv_hd); 2773 KASSERT(bp == NULL || bp->b_bufobj == bo, 2774 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2775 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2776 KASSERT(bp == NULL || bp->b_bufobj == bo, 2777 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2778 #endif 2779 BO_UNLOCK(bo); 2780 } 2781 2782 static void 2783 v_init_counters(struct vnode *vp) 2784 { 2785 2786 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2787 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2788 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2789 2790 refcount_init(&vp->v_holdcnt, 1); 2791 refcount_init(&vp->v_usecount, 1); 2792 } 2793 2794 /* 2795 * Grab a particular vnode from the free list, increment its 2796 * reference count and lock it. VIRF_DOOMED is set if the vnode 2797 * is being destroyed. Only callers who specify LK_RETRY will 2798 * see doomed vnodes. If inactive processing was delayed in 2799 * vput try to do it here. 2800 * 2801 * usecount is manipulated using atomics without holding any locks. 2802 * 2803 * holdcnt can be manipulated using atomics without holding any locks, 2804 * except when transitioning 1<->0, in which case the interlock is held. 2805 * 2806 * Consumers which don't guarantee liveness of the vnode can use SMR to 2807 * try to get a reference. Note this operation can fail since the vnode 2808 * may be awaiting getting freed by the time they get to it. 2809 */ 2810 enum vgetstate 2811 vget_prep_smr(struct vnode *vp) 2812 { 2813 enum vgetstate vs; 2814 2815 VFS_SMR_ASSERT_ENTERED(); 2816 2817 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2818 vs = VGET_USECOUNT; 2819 } else { 2820 if (vhold_smr(vp)) 2821 vs = VGET_HOLDCNT; 2822 else 2823 vs = VGET_NONE; 2824 } 2825 return (vs); 2826 } 2827 2828 enum vgetstate 2829 vget_prep(struct vnode *vp) 2830 { 2831 enum vgetstate vs; 2832 2833 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2834 vs = VGET_USECOUNT; 2835 } else { 2836 vhold(vp); 2837 vs = VGET_HOLDCNT; 2838 } 2839 return (vs); 2840 } 2841 2842 void 2843 vget_abort(struct vnode *vp, enum vgetstate vs) 2844 { 2845 2846 switch (vs) { 2847 case VGET_USECOUNT: 2848 vrele(vp); 2849 break; 2850 case VGET_HOLDCNT: 2851 vdrop(vp); 2852 break; 2853 default: 2854 __assert_unreachable(); 2855 } 2856 } 2857 2858 int 2859 vget(struct vnode *vp, int flags) 2860 { 2861 enum vgetstate vs; 2862 2863 vs = vget_prep(vp); 2864 return (vget_finish(vp, flags, vs)); 2865 } 2866 2867 int 2868 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2869 { 2870 int error; 2871 2872 if ((flags & LK_INTERLOCK) != 0) 2873 ASSERT_VI_LOCKED(vp, __func__); 2874 else 2875 ASSERT_VI_UNLOCKED(vp, __func__); 2876 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 2877 VNPASS(vp->v_holdcnt > 0, vp); 2878 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2879 2880 error = vn_lock(vp, flags); 2881 if (__predict_false(error != 0)) { 2882 vget_abort(vp, vs); 2883 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2884 vp); 2885 return (error); 2886 } 2887 2888 vget_finish_ref(vp, vs); 2889 return (0); 2890 } 2891 2892 void 2893 vget_finish_ref(struct vnode *vp, enum vgetstate vs) 2894 { 2895 int old; 2896 2897 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 2898 VNPASS(vp->v_holdcnt > 0, vp); 2899 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2900 2901 if (vs == VGET_USECOUNT) 2902 return; 2903 2904 /* 2905 * We hold the vnode. If the usecount is 0 it will be utilized to keep 2906 * the vnode around. Otherwise someone else lended their hold count and 2907 * we have to drop ours. 2908 */ 2909 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2910 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 2911 if (old != 0) { 2912 #ifdef INVARIANTS 2913 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2914 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2915 #else 2916 refcount_release(&vp->v_holdcnt); 2917 #endif 2918 } 2919 } 2920 2921 void 2922 vref(struct vnode *vp) 2923 { 2924 enum vgetstate vs; 2925 2926 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2927 vs = vget_prep(vp); 2928 vget_finish_ref(vp, vs); 2929 } 2930 2931 void 2932 vrefact(struct vnode *vp) 2933 { 2934 2935 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2936 #ifdef INVARIANTS 2937 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 2938 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 2939 #else 2940 refcount_acquire(&vp->v_usecount); 2941 #endif 2942 } 2943 2944 void 2945 vlazy(struct vnode *vp) 2946 { 2947 struct mount *mp; 2948 2949 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 2950 2951 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 2952 return; 2953 /* 2954 * We may get here for inactive routines after the vnode got doomed. 2955 */ 2956 if (VN_IS_DOOMED(vp)) 2957 return; 2958 mp = vp->v_mount; 2959 mtx_lock(&mp->mnt_listmtx); 2960 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 2961 vp->v_mflag |= VMP_LAZYLIST; 2962 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 2963 mp->mnt_lazyvnodelistsize++; 2964 } 2965 mtx_unlock(&mp->mnt_listmtx); 2966 } 2967 2968 /* 2969 * This routine is only meant to be called from vgonel prior to dooming 2970 * the vnode. 2971 */ 2972 static void 2973 vunlazy_gone(struct vnode *vp) 2974 { 2975 struct mount *mp; 2976 2977 ASSERT_VOP_ELOCKED(vp, __func__); 2978 ASSERT_VI_LOCKED(vp, __func__); 2979 VNPASS(!VN_IS_DOOMED(vp), vp); 2980 2981 if (vp->v_mflag & VMP_LAZYLIST) { 2982 mp = vp->v_mount; 2983 mtx_lock(&mp->mnt_listmtx); 2984 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 2985 vp->v_mflag &= ~VMP_LAZYLIST; 2986 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 2987 mp->mnt_lazyvnodelistsize--; 2988 mtx_unlock(&mp->mnt_listmtx); 2989 } 2990 } 2991 2992 static void 2993 vdefer_inactive(struct vnode *vp) 2994 { 2995 2996 ASSERT_VI_LOCKED(vp, __func__); 2997 VNASSERT(vp->v_holdcnt > 0, vp, 2998 ("%s: vnode without hold count", __func__)); 2999 if (VN_IS_DOOMED(vp)) { 3000 vdropl(vp); 3001 return; 3002 } 3003 if (vp->v_iflag & VI_DEFINACT) { 3004 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3005 vdropl(vp); 3006 return; 3007 } 3008 if (vp->v_usecount > 0) { 3009 vp->v_iflag &= ~VI_OWEINACT; 3010 vdropl(vp); 3011 return; 3012 } 3013 vlazy(vp); 3014 vp->v_iflag |= VI_DEFINACT; 3015 VI_UNLOCK(vp); 3016 counter_u64_add(deferred_inact, 1); 3017 } 3018 3019 static void 3020 vdefer_inactive_unlocked(struct vnode *vp) 3021 { 3022 3023 VI_LOCK(vp); 3024 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3025 vdropl(vp); 3026 return; 3027 } 3028 vdefer_inactive(vp); 3029 } 3030 3031 enum vput_op { VRELE, VPUT, VUNREF }; 3032 3033 /* 3034 * Handle ->v_usecount transitioning to 0. 3035 * 3036 * By releasing the last usecount we take ownership of the hold count which 3037 * provides liveness of the vnode, meaning we have to vdrop. 3038 * 3039 * For all vnodes we may need to perform inactive processing. It requires an 3040 * exclusive lock on the vnode, while it is legal to call here with only a 3041 * shared lock (or no locks). If locking the vnode in an expected manner fails, 3042 * inactive processing gets deferred to the syncer. 3043 * 3044 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3045 * on the lock being held all the way until VOP_INACTIVE. This in particular 3046 * happens with UFS which adds half-constructed vnodes to the hash, where they 3047 * can be found by other code. 3048 */ 3049 static void 3050 vput_final(struct vnode *vp, enum vput_op func) 3051 { 3052 int error; 3053 bool want_unlock; 3054 3055 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3056 VNPASS(vp->v_holdcnt > 0, vp); 3057 3058 VI_LOCK(vp); 3059 3060 /* 3061 * By the time we got here someone else might have transitioned 3062 * the count back to > 0. 3063 */ 3064 if (vp->v_usecount > 0) 3065 goto out; 3066 3067 /* 3068 * If the vnode is doomed vgone already performed inactive processing 3069 * (if needed). 3070 */ 3071 if (VN_IS_DOOMED(vp)) 3072 goto out; 3073 3074 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0)) 3075 goto out; 3076 3077 if (vp->v_iflag & VI_DOINGINACT) 3078 goto out; 3079 3080 /* 3081 * Locking operations here will drop the interlock and possibly the 3082 * vnode lock, opening a window where the vnode can get doomed all the 3083 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to 3084 * perform inactive. 3085 */ 3086 vp->v_iflag |= VI_OWEINACT; 3087 want_unlock = false; 3088 error = 0; 3089 switch (func) { 3090 case VRELE: 3091 switch (VOP_ISLOCKED(vp)) { 3092 case LK_EXCLUSIVE: 3093 break; 3094 case LK_EXCLOTHER: 3095 case 0: 3096 want_unlock = true; 3097 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3098 VI_LOCK(vp); 3099 break; 3100 default: 3101 /* 3102 * The lock has at least one sharer, but we have no way 3103 * to conclude whether this is us. Play it safe and 3104 * defer processing. 3105 */ 3106 error = EAGAIN; 3107 break; 3108 } 3109 break; 3110 case VPUT: 3111 want_unlock = true; 3112 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3113 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3114 LK_NOWAIT); 3115 VI_LOCK(vp); 3116 } 3117 break; 3118 case VUNREF: 3119 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3120 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3121 VI_LOCK(vp); 3122 } 3123 break; 3124 } 3125 if (error == 0) { 3126 vinactive(vp); 3127 if (want_unlock) 3128 VOP_UNLOCK(vp); 3129 vdropl(vp); 3130 } else { 3131 vdefer_inactive(vp); 3132 } 3133 return; 3134 out: 3135 if (func == VPUT) 3136 VOP_UNLOCK(vp); 3137 vdropl(vp); 3138 } 3139 3140 /* 3141 * Decrement ->v_usecount for a vnode. 3142 * 3143 * Releasing the last use count requires additional processing, see vput_final 3144 * above for details. 3145 * 3146 * Comment above each variant denotes lock state on entry and exit. 3147 */ 3148 3149 /* 3150 * in: any 3151 * out: same as passed in 3152 */ 3153 void 3154 vrele(struct vnode *vp) 3155 { 3156 3157 ASSERT_VI_UNLOCKED(vp, __func__); 3158 if (!refcount_release(&vp->v_usecount)) 3159 return; 3160 vput_final(vp, VRELE); 3161 } 3162 3163 /* 3164 * in: locked 3165 * out: unlocked 3166 */ 3167 void 3168 vput(struct vnode *vp) 3169 { 3170 3171 ASSERT_VOP_LOCKED(vp, __func__); 3172 ASSERT_VI_UNLOCKED(vp, __func__); 3173 if (!refcount_release(&vp->v_usecount)) { 3174 VOP_UNLOCK(vp); 3175 return; 3176 } 3177 vput_final(vp, VPUT); 3178 } 3179 3180 /* 3181 * in: locked 3182 * out: locked 3183 */ 3184 void 3185 vunref(struct vnode *vp) 3186 { 3187 3188 ASSERT_VOP_LOCKED(vp, __func__); 3189 ASSERT_VI_UNLOCKED(vp, __func__); 3190 if (!refcount_release(&vp->v_usecount)) 3191 return; 3192 vput_final(vp, VUNREF); 3193 } 3194 3195 void 3196 vhold(struct vnode *vp) 3197 { 3198 struct vdbatch *vd; 3199 int old; 3200 3201 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3202 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3203 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3204 ("%s: wrong hold count %d", __func__, old)); 3205 if (old != 0) 3206 return; 3207 critical_enter(); 3208 vd = DPCPU_PTR(vd); 3209 vd->freevnodes--; 3210 critical_exit(); 3211 } 3212 3213 void 3214 vholdl(struct vnode *vp) 3215 { 3216 3217 ASSERT_VI_LOCKED(vp, __func__); 3218 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3219 vhold(vp); 3220 } 3221 3222 void 3223 vholdnz(struct vnode *vp) 3224 { 3225 3226 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3227 #ifdef INVARIANTS 3228 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3229 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3230 ("%s: wrong hold count %d", __func__, old)); 3231 #else 3232 atomic_add_int(&vp->v_holdcnt, 1); 3233 #endif 3234 } 3235 3236 /* 3237 * Grab a hold count unless the vnode is freed. 3238 * 3239 * Only use this routine if vfs smr is the only protection you have against 3240 * freeing the vnode. 3241 * 3242 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag 3243 * is not set. After the flag is set the vnode becomes immutable to anyone but 3244 * the thread which managed to set the flag. 3245 * 3246 * It may be tempting to replace the loop with: 3247 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3248 * if (count & VHOLD_NO_SMR) { 3249 * backpedal and error out; 3250 * } 3251 * 3252 * However, while this is more performant, it hinders debugging by eliminating 3253 * the previously mentioned invariant. 3254 */ 3255 bool 3256 vhold_smr(struct vnode *vp) 3257 { 3258 int count; 3259 3260 VFS_SMR_ASSERT_ENTERED(); 3261 3262 count = atomic_load_int(&vp->v_holdcnt); 3263 for (;;) { 3264 if (count & VHOLD_NO_SMR) { 3265 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3266 ("non-zero hold count with flags %d\n", count)); 3267 return (false); 3268 } 3269 3270 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3271 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) 3272 return (true); 3273 } 3274 } 3275 3276 static void __noinline 3277 vdbatch_process(struct vdbatch *vd) 3278 { 3279 struct vnode *vp; 3280 int i; 3281 3282 mtx_assert(&vd->lock, MA_OWNED); 3283 MPASS(curthread->td_pinned > 0); 3284 MPASS(vd->index == VDBATCH_SIZE); 3285 3286 mtx_lock(&vnode_list_mtx); 3287 critical_enter(); 3288 freevnodes += vd->freevnodes; 3289 for (i = 0; i < VDBATCH_SIZE; i++) { 3290 vp = vd->tab[i]; 3291 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3292 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3293 MPASS(vp->v_dbatchcpu != NOCPU); 3294 vp->v_dbatchcpu = NOCPU; 3295 } 3296 mtx_unlock(&vnode_list_mtx); 3297 vd->freevnodes = 0; 3298 bzero(vd->tab, sizeof(vd->tab)); 3299 vd->index = 0; 3300 critical_exit(); 3301 } 3302 3303 static void 3304 vdbatch_enqueue(struct vnode *vp) 3305 { 3306 struct vdbatch *vd; 3307 3308 ASSERT_VI_LOCKED(vp, __func__); 3309 VNASSERT(!VN_IS_DOOMED(vp), vp, 3310 ("%s: deferring requeue of a doomed vnode", __func__)); 3311 3312 critical_enter(); 3313 vd = DPCPU_PTR(vd); 3314 vd->freevnodes++; 3315 if (vp->v_dbatchcpu != NOCPU) { 3316 VI_UNLOCK(vp); 3317 critical_exit(); 3318 return; 3319 } 3320 3321 sched_pin(); 3322 critical_exit(); 3323 mtx_lock(&vd->lock); 3324 MPASS(vd->index < VDBATCH_SIZE); 3325 MPASS(vd->tab[vd->index] == NULL); 3326 /* 3327 * A hack: we depend on being pinned so that we know what to put in 3328 * ->v_dbatchcpu. 3329 */ 3330 vp->v_dbatchcpu = curcpu; 3331 vd->tab[vd->index] = vp; 3332 vd->index++; 3333 VI_UNLOCK(vp); 3334 if (vd->index == VDBATCH_SIZE) 3335 vdbatch_process(vd); 3336 mtx_unlock(&vd->lock); 3337 sched_unpin(); 3338 } 3339 3340 /* 3341 * This routine must only be called for vnodes which are about to be 3342 * deallocated. Supporting dequeue for arbitrary vndoes would require 3343 * validating that the locked batch matches. 3344 */ 3345 static void 3346 vdbatch_dequeue(struct vnode *vp) 3347 { 3348 struct vdbatch *vd; 3349 int i; 3350 short cpu; 3351 3352 VNASSERT(vp->v_type == VBAD || vp->v_type == VNON, vp, 3353 ("%s: called for a used vnode\n", __func__)); 3354 3355 cpu = vp->v_dbatchcpu; 3356 if (cpu == NOCPU) 3357 return; 3358 3359 vd = DPCPU_ID_PTR(cpu, vd); 3360 mtx_lock(&vd->lock); 3361 for (i = 0; i < vd->index; i++) { 3362 if (vd->tab[i] != vp) 3363 continue; 3364 vp->v_dbatchcpu = NOCPU; 3365 vd->index--; 3366 vd->tab[i] = vd->tab[vd->index]; 3367 vd->tab[vd->index] = NULL; 3368 break; 3369 } 3370 mtx_unlock(&vd->lock); 3371 /* 3372 * Either we dequeued the vnode above or the target CPU beat us to it. 3373 */ 3374 MPASS(vp->v_dbatchcpu == NOCPU); 3375 } 3376 3377 /* 3378 * Drop the hold count of the vnode. If this is the last reference to 3379 * the vnode we place it on the free list unless it has been vgone'd 3380 * (marked VIRF_DOOMED) in which case we will free it. 3381 * 3382 * Because the vnode vm object keeps a hold reference on the vnode if 3383 * there is at least one resident non-cached page, the vnode cannot 3384 * leave the active list without the page cleanup done. 3385 */ 3386 static void 3387 vdrop_deactivate(struct vnode *vp) 3388 { 3389 struct mount *mp; 3390 3391 ASSERT_VI_LOCKED(vp, __func__); 3392 /* 3393 * Mark a vnode as free: remove it from its active list 3394 * and put it up for recycling on the freelist. 3395 */ 3396 VNASSERT(!VN_IS_DOOMED(vp), vp, 3397 ("vdrop: returning doomed vnode")); 3398 VNASSERT(vp->v_op != NULL, vp, 3399 ("vdrop: vnode already reclaimed.")); 3400 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 3401 ("vnode with VI_OWEINACT set")); 3402 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, 3403 ("vnode with VI_DEFINACT set")); 3404 if (vp->v_mflag & VMP_LAZYLIST) { 3405 mp = vp->v_mount; 3406 mtx_lock(&mp->mnt_listmtx); 3407 VNASSERT(vp->v_mflag & VMP_LAZYLIST, vp, ("lost VMP_LAZYLIST")); 3408 /* 3409 * Don't remove the vnode from the lazy list if another thread 3410 * has increased the hold count. It may have re-enqueued the 3411 * vnode to the lazy list and is now responsible for its 3412 * removal. 3413 */ 3414 if (vp->v_holdcnt == 0) { 3415 vp->v_mflag &= ~VMP_LAZYLIST; 3416 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3417 mp->mnt_lazyvnodelistsize--; 3418 } 3419 mtx_unlock(&mp->mnt_listmtx); 3420 } 3421 vdbatch_enqueue(vp); 3422 } 3423 3424 void 3425 vdrop(struct vnode *vp) 3426 { 3427 3428 ASSERT_VI_UNLOCKED(vp, __func__); 3429 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3430 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3431 return; 3432 VI_LOCK(vp); 3433 vdropl(vp); 3434 } 3435 3436 void 3437 vdropl(struct vnode *vp) 3438 { 3439 3440 ASSERT_VI_LOCKED(vp, __func__); 3441 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3442 if (!refcount_release(&vp->v_holdcnt)) { 3443 VI_UNLOCK(vp); 3444 return; 3445 } 3446 if (!VN_IS_DOOMED(vp)) { 3447 vdrop_deactivate(vp); 3448 /* 3449 * Also unlocks the interlock. We can't assert on it as we 3450 * released our hold and by now the vnode might have been 3451 * freed. 3452 */ 3453 return; 3454 } 3455 /* 3456 * Set the VHOLD_NO_SMR flag. 3457 * 3458 * We may be racing against vhold_smr. If they win we can just pretend 3459 * we never got this far, they will vdrop later. 3460 */ 3461 if (!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR)) { 3462 VI_UNLOCK(vp); 3463 /* 3464 * We lost the aforementioned race. Any subsequent access is 3465 * invalid as they might have managed to vdropl on their own. 3466 */ 3467 return; 3468 } 3469 freevnode(vp); 3470 } 3471 3472 /* 3473 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3474 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3475 */ 3476 static void 3477 vinactivef(struct vnode *vp) 3478 { 3479 struct vm_object *obj; 3480 3481 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3482 ASSERT_VI_LOCKED(vp, "vinactive"); 3483 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3484 ("vinactive: recursed on VI_DOINGINACT")); 3485 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3486 vp->v_iflag |= VI_DOINGINACT; 3487 vp->v_iflag &= ~VI_OWEINACT; 3488 VI_UNLOCK(vp); 3489 /* 3490 * Before moving off the active list, we must be sure that any 3491 * modified pages are converted into the vnode's dirty 3492 * buffers, since these will no longer be checked once the 3493 * vnode is on the inactive list. 3494 * 3495 * The write-out of the dirty pages is asynchronous. At the 3496 * point that VOP_INACTIVE() is called, there could still be 3497 * pending I/O and dirty pages in the object. 3498 */ 3499 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3500 vm_object_mightbedirty(obj)) { 3501 VM_OBJECT_WLOCK(obj); 3502 vm_object_page_clean(obj, 0, 0, 0); 3503 VM_OBJECT_WUNLOCK(obj); 3504 } 3505 VOP_INACTIVE(vp, curthread); 3506 VI_LOCK(vp); 3507 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3508 ("vinactive: lost VI_DOINGINACT")); 3509 vp->v_iflag &= ~VI_DOINGINACT; 3510 } 3511 3512 void 3513 vinactive(struct vnode *vp) 3514 { 3515 3516 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3517 ASSERT_VI_LOCKED(vp, "vinactive"); 3518 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3519 3520 if ((vp->v_iflag & VI_OWEINACT) == 0) 3521 return; 3522 if (vp->v_iflag & VI_DOINGINACT) 3523 return; 3524 if (vp->v_usecount > 0) { 3525 vp->v_iflag &= ~VI_OWEINACT; 3526 return; 3527 } 3528 vinactivef(vp); 3529 } 3530 3531 /* 3532 * Remove any vnodes in the vnode table belonging to mount point mp. 3533 * 3534 * If FORCECLOSE is not specified, there should not be any active ones, 3535 * return error if any are found (nb: this is a user error, not a 3536 * system error). If FORCECLOSE is specified, detach any active vnodes 3537 * that are found. 3538 * 3539 * If WRITECLOSE is set, only flush out regular file vnodes open for 3540 * writing. 3541 * 3542 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3543 * 3544 * `rootrefs' specifies the base reference count for the root vnode 3545 * of this filesystem. The root vnode is considered busy if its 3546 * v_usecount exceeds this value. On a successful return, vflush(, td) 3547 * will call vrele() on the root vnode exactly rootrefs times. 3548 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3549 * be zero. 3550 */ 3551 #ifdef DIAGNOSTIC 3552 static int busyprt = 0; /* print out busy vnodes */ 3553 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3554 #endif 3555 3556 int 3557 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3558 { 3559 struct vnode *vp, *mvp, *rootvp = NULL; 3560 struct vattr vattr; 3561 int busy = 0, error; 3562 3563 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3564 rootrefs, flags); 3565 if (rootrefs > 0) { 3566 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3567 ("vflush: bad args")); 3568 /* 3569 * Get the filesystem root vnode. We can vput() it 3570 * immediately, since with rootrefs > 0, it won't go away. 3571 */ 3572 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3573 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3574 __func__, error); 3575 return (error); 3576 } 3577 vput(rootvp); 3578 } 3579 loop: 3580 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3581 vholdl(vp); 3582 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3583 if (error) { 3584 vdrop(vp); 3585 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3586 goto loop; 3587 } 3588 /* 3589 * Skip over a vnodes marked VV_SYSTEM. 3590 */ 3591 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3592 VOP_UNLOCK(vp); 3593 vdrop(vp); 3594 continue; 3595 } 3596 /* 3597 * If WRITECLOSE is set, flush out unlinked but still open 3598 * files (even if open only for reading) and regular file 3599 * vnodes open for writing. 3600 */ 3601 if (flags & WRITECLOSE) { 3602 if (vp->v_object != NULL) { 3603 VM_OBJECT_WLOCK(vp->v_object); 3604 vm_object_page_clean(vp->v_object, 0, 0, 0); 3605 VM_OBJECT_WUNLOCK(vp->v_object); 3606 } 3607 error = VOP_FSYNC(vp, MNT_WAIT, td); 3608 if (error != 0) { 3609 VOP_UNLOCK(vp); 3610 vdrop(vp); 3611 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3612 return (error); 3613 } 3614 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3615 VI_LOCK(vp); 3616 3617 if ((vp->v_type == VNON || 3618 (error == 0 && vattr.va_nlink > 0)) && 3619 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3620 VOP_UNLOCK(vp); 3621 vdropl(vp); 3622 continue; 3623 } 3624 } else 3625 VI_LOCK(vp); 3626 /* 3627 * With v_usecount == 0, all we need to do is clear out the 3628 * vnode data structures and we are done. 3629 * 3630 * If FORCECLOSE is set, forcibly close the vnode. 3631 */ 3632 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3633 vgonel(vp); 3634 } else { 3635 busy++; 3636 #ifdef DIAGNOSTIC 3637 if (busyprt) 3638 vn_printf(vp, "vflush: busy vnode "); 3639 #endif 3640 } 3641 VOP_UNLOCK(vp); 3642 vdropl(vp); 3643 } 3644 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3645 /* 3646 * If just the root vnode is busy, and if its refcount 3647 * is equal to `rootrefs', then go ahead and kill it. 3648 */ 3649 VI_LOCK(rootvp); 3650 KASSERT(busy > 0, ("vflush: not busy")); 3651 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3652 ("vflush: usecount %d < rootrefs %d", 3653 rootvp->v_usecount, rootrefs)); 3654 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3655 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3656 vgone(rootvp); 3657 VOP_UNLOCK(rootvp); 3658 busy = 0; 3659 } else 3660 VI_UNLOCK(rootvp); 3661 } 3662 if (busy) { 3663 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3664 busy); 3665 return (EBUSY); 3666 } 3667 for (; rootrefs > 0; rootrefs--) 3668 vrele(rootvp); 3669 return (0); 3670 } 3671 3672 /* 3673 * Recycle an unused vnode to the front of the free list. 3674 */ 3675 int 3676 vrecycle(struct vnode *vp) 3677 { 3678 int recycled; 3679 3680 VI_LOCK(vp); 3681 recycled = vrecyclel(vp); 3682 VI_UNLOCK(vp); 3683 return (recycled); 3684 } 3685 3686 /* 3687 * vrecycle, with the vp interlock held. 3688 */ 3689 int 3690 vrecyclel(struct vnode *vp) 3691 { 3692 int recycled; 3693 3694 ASSERT_VOP_ELOCKED(vp, __func__); 3695 ASSERT_VI_LOCKED(vp, __func__); 3696 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3697 recycled = 0; 3698 if (vp->v_usecount == 0) { 3699 recycled = 1; 3700 vgonel(vp); 3701 } 3702 return (recycled); 3703 } 3704 3705 /* 3706 * Eliminate all activity associated with a vnode 3707 * in preparation for reuse. 3708 */ 3709 void 3710 vgone(struct vnode *vp) 3711 { 3712 VI_LOCK(vp); 3713 vgonel(vp); 3714 VI_UNLOCK(vp); 3715 } 3716 3717 static void 3718 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3719 struct vnode *lowervp __unused) 3720 { 3721 } 3722 3723 /* 3724 * Notify upper mounts about reclaimed or unlinked vnode. 3725 */ 3726 void 3727 vfs_notify_upper(struct vnode *vp, int event) 3728 { 3729 static struct vfsops vgonel_vfsops = { 3730 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3731 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3732 }; 3733 struct mount *mp, *ump, *mmp; 3734 3735 mp = vp->v_mount; 3736 if (mp == NULL) 3737 return; 3738 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3739 return; 3740 3741 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3742 mmp->mnt_op = &vgonel_vfsops; 3743 mmp->mnt_kern_flag |= MNTK_MARKER; 3744 MNT_ILOCK(mp); 3745 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3746 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3747 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3748 ump = TAILQ_NEXT(ump, mnt_upper_link); 3749 continue; 3750 } 3751 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3752 MNT_IUNLOCK(mp); 3753 switch (event) { 3754 case VFS_NOTIFY_UPPER_RECLAIM: 3755 VFS_RECLAIM_LOWERVP(ump, vp); 3756 break; 3757 case VFS_NOTIFY_UPPER_UNLINK: 3758 VFS_UNLINK_LOWERVP(ump, vp); 3759 break; 3760 default: 3761 KASSERT(0, ("invalid event %d", event)); 3762 break; 3763 } 3764 MNT_ILOCK(mp); 3765 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3766 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3767 } 3768 free(mmp, M_TEMP); 3769 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3770 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3771 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3772 wakeup(&mp->mnt_uppers); 3773 } 3774 MNT_IUNLOCK(mp); 3775 } 3776 3777 /* 3778 * vgone, with the vp interlock held. 3779 */ 3780 static void 3781 vgonel(struct vnode *vp) 3782 { 3783 struct thread *td; 3784 struct mount *mp; 3785 vm_object_t object; 3786 bool active, oweinact; 3787 3788 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3789 ASSERT_VI_LOCKED(vp, "vgonel"); 3790 VNASSERT(vp->v_holdcnt, vp, 3791 ("vgonel: vp %p has no reference.", vp)); 3792 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3793 td = curthread; 3794 3795 /* 3796 * Don't vgonel if we're already doomed. 3797 */ 3798 if (vp->v_irflag & VIRF_DOOMED) 3799 return; 3800 /* 3801 * Paired with freevnode. 3802 */ 3803 vn_seqc_write_begin_locked(vp); 3804 vunlazy_gone(vp); 3805 vp->v_irflag |= VIRF_DOOMED; 3806 3807 /* 3808 * Check to see if the vnode is in use. If so, we have to call 3809 * VOP_CLOSE() and VOP_INACTIVE(). 3810 */ 3811 active = vp->v_usecount > 0; 3812 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 3813 /* 3814 * If we need to do inactive VI_OWEINACT will be set. 3815 */ 3816 if (vp->v_iflag & VI_DEFINACT) { 3817 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3818 vp->v_iflag &= ~VI_DEFINACT; 3819 vdropl(vp); 3820 } else { 3821 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 3822 VI_UNLOCK(vp); 3823 } 3824 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3825 3826 /* 3827 * If purging an active vnode, it must be closed and 3828 * deactivated before being reclaimed. 3829 */ 3830 if (active) 3831 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3832 if (oweinact || active) { 3833 VI_LOCK(vp); 3834 vinactivef(vp); 3835 VI_UNLOCK(vp); 3836 } 3837 if (vp->v_type == VSOCK) 3838 vfs_unp_reclaim(vp); 3839 3840 /* 3841 * Clean out any buffers associated with the vnode. 3842 * If the flush fails, just toss the buffers. 3843 */ 3844 mp = NULL; 3845 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3846 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3847 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3848 while (vinvalbuf(vp, 0, 0, 0) != 0) 3849 ; 3850 } 3851 3852 BO_LOCK(&vp->v_bufobj); 3853 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3854 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3855 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3856 vp->v_bufobj.bo_clean.bv_cnt == 0, 3857 ("vp %p bufobj not invalidated", vp)); 3858 3859 /* 3860 * For VMIO bufobj, BO_DEAD is set later, or in 3861 * vm_object_terminate() after the object's page queue is 3862 * flushed. 3863 */ 3864 object = vp->v_bufobj.bo_object; 3865 if (object == NULL) 3866 vp->v_bufobj.bo_flag |= BO_DEAD; 3867 BO_UNLOCK(&vp->v_bufobj); 3868 3869 /* 3870 * Handle the VM part. Tmpfs handles v_object on its own (the 3871 * OBJT_VNODE check). Nullfs or other bypassing filesystems 3872 * should not touch the object borrowed from the lower vnode 3873 * (the handle check). 3874 */ 3875 if (object != NULL && object->type == OBJT_VNODE && 3876 object->handle == vp) 3877 vnode_destroy_vobject(vp); 3878 3879 /* 3880 * Reclaim the vnode. 3881 */ 3882 if (VOP_RECLAIM(vp, td)) 3883 panic("vgone: cannot reclaim"); 3884 if (mp != NULL) 3885 vn_finished_secondary_write(mp); 3886 VNASSERT(vp->v_object == NULL, vp, 3887 ("vop_reclaim left v_object vp=%p", vp)); 3888 /* 3889 * Clear the advisory locks and wake up waiting threads. 3890 */ 3891 (void)VOP_ADVLOCKPURGE(vp); 3892 vp->v_lockf = NULL; 3893 /* 3894 * Delete from old mount point vnode list. 3895 */ 3896 delmntque(vp); 3897 cache_purge_vgone(vp); 3898 /* 3899 * Done with purge, reset to the standard lock and invalidate 3900 * the vnode. 3901 */ 3902 VI_LOCK(vp); 3903 vp->v_vnlock = &vp->v_lock; 3904 vp->v_op = &dead_vnodeops; 3905 vp->v_type = VBAD; 3906 } 3907 3908 /* 3909 * Print out a description of a vnode. 3910 */ 3911 static const char * const typename[] = 3912 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3913 "VMARKER"}; 3914 3915 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0, 3916 "new hold count flag not added to vn_printf"); 3917 3918 void 3919 vn_printf(struct vnode *vp, const char *fmt, ...) 3920 { 3921 va_list ap; 3922 char buf[256], buf2[16]; 3923 u_long flags; 3924 u_int holdcnt; 3925 3926 va_start(ap, fmt); 3927 vprintf(fmt, ap); 3928 va_end(ap); 3929 printf("%p: ", (void *)vp); 3930 printf("type %s\n", typename[vp->v_type]); 3931 holdcnt = atomic_load_int(&vp->v_holdcnt); 3932 printf(" usecount %d, writecount %d, refcount %d seqc users %d", 3933 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS, 3934 vp->v_seqc_users); 3935 switch (vp->v_type) { 3936 case VDIR: 3937 printf(" mountedhere %p\n", vp->v_mountedhere); 3938 break; 3939 case VCHR: 3940 printf(" rdev %p\n", vp->v_rdev); 3941 break; 3942 case VSOCK: 3943 printf(" socket %p\n", vp->v_unpcb); 3944 break; 3945 case VFIFO: 3946 printf(" fifoinfo %p\n", vp->v_fifoinfo); 3947 break; 3948 default: 3949 printf("\n"); 3950 break; 3951 } 3952 buf[0] = '\0'; 3953 buf[1] = '\0'; 3954 if (holdcnt & VHOLD_NO_SMR) 3955 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf)); 3956 printf(" hold count flags (%s)\n", buf + 1); 3957 3958 buf[0] = '\0'; 3959 buf[1] = '\0'; 3960 if (vp->v_irflag & VIRF_DOOMED) 3961 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 3962 if (vp->v_irflag & VIRF_PGREAD) 3963 strlcat(buf, "|VIRF_PGREAD", sizeof(buf)); 3964 flags = vp->v_irflag & ~(VIRF_DOOMED | VIRF_PGREAD); 3965 if (flags != 0) { 3966 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 3967 strlcat(buf, buf2, sizeof(buf)); 3968 } 3969 if (vp->v_vflag & VV_ROOT) 3970 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3971 if (vp->v_vflag & VV_ISTTY) 3972 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3973 if (vp->v_vflag & VV_NOSYNC) 3974 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3975 if (vp->v_vflag & VV_ETERNALDEV) 3976 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3977 if (vp->v_vflag & VV_CACHEDLABEL) 3978 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3979 if (vp->v_vflag & VV_VMSIZEVNLOCK) 3980 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 3981 if (vp->v_vflag & VV_COPYONWRITE) 3982 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3983 if (vp->v_vflag & VV_SYSTEM) 3984 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3985 if (vp->v_vflag & VV_PROCDEP) 3986 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3987 if (vp->v_vflag & VV_NOKNOTE) 3988 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3989 if (vp->v_vflag & VV_DELETED) 3990 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3991 if (vp->v_vflag & VV_MD) 3992 strlcat(buf, "|VV_MD", sizeof(buf)); 3993 if (vp->v_vflag & VV_FORCEINSMQ) 3994 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3995 if (vp->v_vflag & VV_READLINK) 3996 strlcat(buf, "|VV_READLINK", sizeof(buf)); 3997 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3998 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3999 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 4000 if (flags != 0) { 4001 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4002 strlcat(buf, buf2, sizeof(buf)); 4003 } 4004 if (vp->v_iflag & VI_TEXT_REF) 4005 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 4006 if (vp->v_iflag & VI_MOUNT) 4007 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4008 if (vp->v_iflag & VI_DOINGINACT) 4009 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4010 if (vp->v_iflag & VI_OWEINACT) 4011 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4012 if (vp->v_iflag & VI_DEFINACT) 4013 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4014 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | 4015 VI_OWEINACT | VI_DEFINACT); 4016 if (flags != 0) { 4017 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4018 strlcat(buf, buf2, sizeof(buf)); 4019 } 4020 if (vp->v_mflag & VMP_LAZYLIST) 4021 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4022 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4023 if (flags != 0) { 4024 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4025 strlcat(buf, buf2, sizeof(buf)); 4026 } 4027 printf(" flags (%s)\n", buf + 1); 4028 if (mtx_owned(VI_MTX(vp))) 4029 printf(" VI_LOCKed"); 4030 if (vp->v_object != NULL) 4031 printf(" v_object %p ref %d pages %d " 4032 "cleanbuf %d dirtybuf %d\n", 4033 vp->v_object, vp->v_object->ref_count, 4034 vp->v_object->resident_page_count, 4035 vp->v_bufobj.bo_clean.bv_cnt, 4036 vp->v_bufobj.bo_dirty.bv_cnt); 4037 printf(" "); 4038 lockmgr_printinfo(vp->v_vnlock); 4039 if (vp->v_data != NULL) 4040 VOP_PRINT(vp); 4041 } 4042 4043 #ifdef DDB 4044 /* 4045 * List all of the locked vnodes in the system. 4046 * Called when debugging the kernel. 4047 */ 4048 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 4049 { 4050 struct mount *mp; 4051 struct vnode *vp; 4052 4053 /* 4054 * Note: because this is DDB, we can't obey the locking semantics 4055 * for these structures, which means we could catch an inconsistent 4056 * state and dereference a nasty pointer. Not much to be done 4057 * about that. 4058 */ 4059 db_printf("Locked vnodes\n"); 4060 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4061 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4062 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4063 vn_printf(vp, "vnode "); 4064 } 4065 } 4066 } 4067 4068 /* 4069 * Show details about the given vnode. 4070 */ 4071 DB_SHOW_COMMAND(vnode, db_show_vnode) 4072 { 4073 struct vnode *vp; 4074 4075 if (!have_addr) 4076 return; 4077 vp = (struct vnode *)addr; 4078 vn_printf(vp, "vnode "); 4079 } 4080 4081 /* 4082 * Show details about the given mount point. 4083 */ 4084 DB_SHOW_COMMAND(mount, db_show_mount) 4085 { 4086 struct mount *mp; 4087 struct vfsopt *opt; 4088 struct statfs *sp; 4089 struct vnode *vp; 4090 char buf[512]; 4091 uint64_t mflags; 4092 u_int flags; 4093 4094 if (!have_addr) { 4095 /* No address given, print short info about all mount points. */ 4096 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4097 db_printf("%p %s on %s (%s)\n", mp, 4098 mp->mnt_stat.f_mntfromname, 4099 mp->mnt_stat.f_mntonname, 4100 mp->mnt_stat.f_fstypename); 4101 if (db_pager_quit) 4102 break; 4103 } 4104 db_printf("\nMore info: show mount <addr>\n"); 4105 return; 4106 } 4107 4108 mp = (struct mount *)addr; 4109 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4110 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4111 4112 buf[0] = '\0'; 4113 mflags = mp->mnt_flag; 4114 #define MNT_FLAG(flag) do { \ 4115 if (mflags & (flag)) { \ 4116 if (buf[0] != '\0') \ 4117 strlcat(buf, ", ", sizeof(buf)); \ 4118 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4119 mflags &= ~(flag); \ 4120 } \ 4121 } while (0) 4122 MNT_FLAG(MNT_RDONLY); 4123 MNT_FLAG(MNT_SYNCHRONOUS); 4124 MNT_FLAG(MNT_NOEXEC); 4125 MNT_FLAG(MNT_NOSUID); 4126 MNT_FLAG(MNT_NFS4ACLS); 4127 MNT_FLAG(MNT_UNION); 4128 MNT_FLAG(MNT_ASYNC); 4129 MNT_FLAG(MNT_SUIDDIR); 4130 MNT_FLAG(MNT_SOFTDEP); 4131 MNT_FLAG(MNT_NOSYMFOLLOW); 4132 MNT_FLAG(MNT_GJOURNAL); 4133 MNT_FLAG(MNT_MULTILABEL); 4134 MNT_FLAG(MNT_ACLS); 4135 MNT_FLAG(MNT_NOATIME); 4136 MNT_FLAG(MNT_NOCLUSTERR); 4137 MNT_FLAG(MNT_NOCLUSTERW); 4138 MNT_FLAG(MNT_SUJ); 4139 MNT_FLAG(MNT_EXRDONLY); 4140 MNT_FLAG(MNT_EXPORTED); 4141 MNT_FLAG(MNT_DEFEXPORTED); 4142 MNT_FLAG(MNT_EXPORTANON); 4143 MNT_FLAG(MNT_EXKERB); 4144 MNT_FLAG(MNT_EXPUBLIC); 4145 MNT_FLAG(MNT_LOCAL); 4146 MNT_FLAG(MNT_QUOTA); 4147 MNT_FLAG(MNT_ROOTFS); 4148 MNT_FLAG(MNT_USER); 4149 MNT_FLAG(MNT_IGNORE); 4150 MNT_FLAG(MNT_UPDATE); 4151 MNT_FLAG(MNT_DELEXPORT); 4152 MNT_FLAG(MNT_RELOAD); 4153 MNT_FLAG(MNT_FORCE); 4154 MNT_FLAG(MNT_SNAPSHOT); 4155 MNT_FLAG(MNT_BYFSID); 4156 #undef MNT_FLAG 4157 if (mflags != 0) { 4158 if (buf[0] != '\0') 4159 strlcat(buf, ", ", sizeof(buf)); 4160 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4161 "0x%016jx", mflags); 4162 } 4163 db_printf(" mnt_flag = %s\n", buf); 4164 4165 buf[0] = '\0'; 4166 flags = mp->mnt_kern_flag; 4167 #define MNT_KERN_FLAG(flag) do { \ 4168 if (flags & (flag)) { \ 4169 if (buf[0] != '\0') \ 4170 strlcat(buf, ", ", sizeof(buf)); \ 4171 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4172 flags &= ~(flag); \ 4173 } \ 4174 } while (0) 4175 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4176 MNT_KERN_FLAG(MNTK_ASYNC); 4177 MNT_KERN_FLAG(MNTK_SOFTDEP); 4178 MNT_KERN_FLAG(MNTK_DRAINING); 4179 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4180 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4181 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4182 MNT_KERN_FLAG(MNTK_NO_IOPF); 4183 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 4184 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 4185 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 4186 MNT_KERN_FLAG(MNTK_MARKER); 4187 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4188 MNT_KERN_FLAG(MNTK_FPLOOKUP); 4189 MNT_KERN_FLAG(MNTK_NOASYNC); 4190 MNT_KERN_FLAG(MNTK_UNMOUNT); 4191 MNT_KERN_FLAG(MNTK_MWAIT); 4192 MNT_KERN_FLAG(MNTK_SUSPEND); 4193 MNT_KERN_FLAG(MNTK_SUSPEND2); 4194 MNT_KERN_FLAG(MNTK_SUSPENDED); 4195 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4196 MNT_KERN_FLAG(MNTK_NOKNOTE); 4197 #undef MNT_KERN_FLAG 4198 if (flags != 0) { 4199 if (buf[0] != '\0') 4200 strlcat(buf, ", ", sizeof(buf)); 4201 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4202 "0x%08x", flags); 4203 } 4204 db_printf(" mnt_kern_flag = %s\n", buf); 4205 4206 db_printf(" mnt_opt = "); 4207 opt = TAILQ_FIRST(mp->mnt_opt); 4208 if (opt != NULL) { 4209 db_printf("%s", opt->name); 4210 opt = TAILQ_NEXT(opt, link); 4211 while (opt != NULL) { 4212 db_printf(", %s", opt->name); 4213 opt = TAILQ_NEXT(opt, link); 4214 } 4215 } 4216 db_printf("\n"); 4217 4218 sp = &mp->mnt_stat; 4219 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4220 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4221 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4222 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4223 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4224 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4225 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4226 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4227 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4228 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4229 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4230 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4231 4232 db_printf(" mnt_cred = { uid=%u ruid=%u", 4233 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4234 if (jailed(mp->mnt_cred)) 4235 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4236 db_printf(" }\n"); 4237 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4238 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4239 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4240 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4241 db_printf(" mnt_lazyvnodelistsize = %d\n", 4242 mp->mnt_lazyvnodelistsize); 4243 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4244 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4245 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4246 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4247 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4248 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4249 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4250 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4251 db_printf(" mnt_secondary_accwrites = %d\n", 4252 mp->mnt_secondary_accwrites); 4253 db_printf(" mnt_gjprovider = %s\n", 4254 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4255 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4256 4257 db_printf("\n\nList of active vnodes\n"); 4258 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4259 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4260 vn_printf(vp, "vnode "); 4261 if (db_pager_quit) 4262 break; 4263 } 4264 } 4265 db_printf("\n\nList of inactive vnodes\n"); 4266 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4267 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4268 vn_printf(vp, "vnode "); 4269 if (db_pager_quit) 4270 break; 4271 } 4272 } 4273 } 4274 #endif /* DDB */ 4275 4276 /* 4277 * Fill in a struct xvfsconf based on a struct vfsconf. 4278 */ 4279 static int 4280 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4281 { 4282 struct xvfsconf xvfsp; 4283 4284 bzero(&xvfsp, sizeof(xvfsp)); 4285 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4286 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4287 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4288 xvfsp.vfc_flags = vfsp->vfc_flags; 4289 /* 4290 * These are unused in userland, we keep them 4291 * to not break binary compatibility. 4292 */ 4293 xvfsp.vfc_vfsops = NULL; 4294 xvfsp.vfc_next = NULL; 4295 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4296 } 4297 4298 #ifdef COMPAT_FREEBSD32 4299 struct xvfsconf32 { 4300 uint32_t vfc_vfsops; 4301 char vfc_name[MFSNAMELEN]; 4302 int32_t vfc_typenum; 4303 int32_t vfc_refcount; 4304 int32_t vfc_flags; 4305 uint32_t vfc_next; 4306 }; 4307 4308 static int 4309 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4310 { 4311 struct xvfsconf32 xvfsp; 4312 4313 bzero(&xvfsp, sizeof(xvfsp)); 4314 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4315 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4316 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4317 xvfsp.vfc_flags = vfsp->vfc_flags; 4318 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4319 } 4320 #endif 4321 4322 /* 4323 * Top level filesystem related information gathering. 4324 */ 4325 static int 4326 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4327 { 4328 struct vfsconf *vfsp; 4329 int error; 4330 4331 error = 0; 4332 vfsconf_slock(); 4333 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4334 #ifdef COMPAT_FREEBSD32 4335 if (req->flags & SCTL_MASK32) 4336 error = vfsconf2x32(req, vfsp); 4337 else 4338 #endif 4339 error = vfsconf2x(req, vfsp); 4340 if (error) 4341 break; 4342 } 4343 vfsconf_sunlock(); 4344 return (error); 4345 } 4346 4347 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4348 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4349 "S,xvfsconf", "List of all configured filesystems"); 4350 4351 #ifndef BURN_BRIDGES 4352 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4353 4354 static int 4355 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4356 { 4357 int *name = (int *)arg1 - 1; /* XXX */ 4358 u_int namelen = arg2 + 1; /* XXX */ 4359 struct vfsconf *vfsp; 4360 4361 log(LOG_WARNING, "userland calling deprecated sysctl, " 4362 "please rebuild world\n"); 4363 4364 #if 1 || defined(COMPAT_PRELITE2) 4365 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4366 if (namelen == 1) 4367 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4368 #endif 4369 4370 switch (name[1]) { 4371 case VFS_MAXTYPENUM: 4372 if (namelen != 2) 4373 return (ENOTDIR); 4374 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4375 case VFS_CONF: 4376 if (namelen != 3) 4377 return (ENOTDIR); /* overloaded */ 4378 vfsconf_slock(); 4379 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4380 if (vfsp->vfc_typenum == name[2]) 4381 break; 4382 } 4383 vfsconf_sunlock(); 4384 if (vfsp == NULL) 4385 return (EOPNOTSUPP); 4386 #ifdef COMPAT_FREEBSD32 4387 if (req->flags & SCTL_MASK32) 4388 return (vfsconf2x32(req, vfsp)); 4389 else 4390 #endif 4391 return (vfsconf2x(req, vfsp)); 4392 } 4393 return (EOPNOTSUPP); 4394 } 4395 4396 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4397 CTLFLAG_MPSAFE, vfs_sysctl, 4398 "Generic filesystem"); 4399 4400 #if 1 || defined(COMPAT_PRELITE2) 4401 4402 static int 4403 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4404 { 4405 int error; 4406 struct vfsconf *vfsp; 4407 struct ovfsconf ovfs; 4408 4409 vfsconf_slock(); 4410 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4411 bzero(&ovfs, sizeof(ovfs)); 4412 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4413 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4414 ovfs.vfc_index = vfsp->vfc_typenum; 4415 ovfs.vfc_refcount = vfsp->vfc_refcount; 4416 ovfs.vfc_flags = vfsp->vfc_flags; 4417 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4418 if (error != 0) { 4419 vfsconf_sunlock(); 4420 return (error); 4421 } 4422 } 4423 vfsconf_sunlock(); 4424 return (0); 4425 } 4426 4427 #endif /* 1 || COMPAT_PRELITE2 */ 4428 #endif /* !BURN_BRIDGES */ 4429 4430 #define KINFO_VNODESLOP 10 4431 #ifdef notyet 4432 /* 4433 * Dump vnode list (via sysctl). 4434 */ 4435 /* ARGSUSED */ 4436 static int 4437 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4438 { 4439 struct xvnode *xvn; 4440 struct mount *mp; 4441 struct vnode *vp; 4442 int error, len, n; 4443 4444 /* 4445 * Stale numvnodes access is not fatal here. 4446 */ 4447 req->lock = 0; 4448 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4449 if (!req->oldptr) 4450 /* Make an estimate */ 4451 return (SYSCTL_OUT(req, 0, len)); 4452 4453 error = sysctl_wire_old_buffer(req, 0); 4454 if (error != 0) 4455 return (error); 4456 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4457 n = 0; 4458 mtx_lock(&mountlist_mtx); 4459 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4460 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4461 continue; 4462 MNT_ILOCK(mp); 4463 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4464 if (n == len) 4465 break; 4466 vref(vp); 4467 xvn[n].xv_size = sizeof *xvn; 4468 xvn[n].xv_vnode = vp; 4469 xvn[n].xv_id = 0; /* XXX compat */ 4470 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4471 XV_COPY(usecount); 4472 XV_COPY(writecount); 4473 XV_COPY(holdcnt); 4474 XV_COPY(mount); 4475 XV_COPY(numoutput); 4476 XV_COPY(type); 4477 #undef XV_COPY 4478 xvn[n].xv_flag = vp->v_vflag; 4479 4480 switch (vp->v_type) { 4481 case VREG: 4482 case VDIR: 4483 case VLNK: 4484 break; 4485 case VBLK: 4486 case VCHR: 4487 if (vp->v_rdev == NULL) { 4488 vrele(vp); 4489 continue; 4490 } 4491 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4492 break; 4493 case VSOCK: 4494 xvn[n].xv_socket = vp->v_socket; 4495 break; 4496 case VFIFO: 4497 xvn[n].xv_fifo = vp->v_fifoinfo; 4498 break; 4499 case VNON: 4500 case VBAD: 4501 default: 4502 /* shouldn't happen? */ 4503 vrele(vp); 4504 continue; 4505 } 4506 vrele(vp); 4507 ++n; 4508 } 4509 MNT_IUNLOCK(mp); 4510 mtx_lock(&mountlist_mtx); 4511 vfs_unbusy(mp); 4512 if (n == len) 4513 break; 4514 } 4515 mtx_unlock(&mountlist_mtx); 4516 4517 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4518 free(xvn, M_TEMP); 4519 return (error); 4520 } 4521 4522 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4523 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4524 ""); 4525 #endif 4526 4527 static void 4528 unmount_or_warn(struct mount *mp) 4529 { 4530 int error; 4531 4532 error = dounmount(mp, MNT_FORCE, curthread); 4533 if (error != 0) { 4534 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4535 if (error == EBUSY) 4536 printf("BUSY)\n"); 4537 else 4538 printf("%d)\n", error); 4539 } 4540 } 4541 4542 /* 4543 * Unmount all filesystems. The list is traversed in reverse order 4544 * of mounting to avoid dependencies. 4545 */ 4546 void 4547 vfs_unmountall(void) 4548 { 4549 struct mount *mp, *tmp; 4550 4551 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4552 4553 /* 4554 * Since this only runs when rebooting, it is not interlocked. 4555 */ 4556 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4557 vfs_ref(mp); 4558 4559 /* 4560 * Forcibly unmounting "/dev" before "/" would prevent clean 4561 * unmount of the latter. 4562 */ 4563 if (mp == rootdevmp) 4564 continue; 4565 4566 unmount_or_warn(mp); 4567 } 4568 4569 if (rootdevmp != NULL) 4570 unmount_or_warn(rootdevmp); 4571 } 4572 4573 static void 4574 vfs_deferred_inactive(struct vnode *vp, int lkflags) 4575 { 4576 4577 ASSERT_VI_LOCKED(vp, __func__); 4578 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, ("VI_DEFINACT still set")); 4579 if ((vp->v_iflag & VI_OWEINACT) == 0) { 4580 vdropl(vp); 4581 return; 4582 } 4583 if (vn_lock(vp, lkflags) == 0) { 4584 VI_LOCK(vp); 4585 vinactive(vp); 4586 VOP_UNLOCK(vp); 4587 vdropl(vp); 4588 return; 4589 } 4590 vdefer_inactive_unlocked(vp); 4591 } 4592 4593 static int 4594 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 4595 { 4596 4597 return (vp->v_iflag & VI_DEFINACT); 4598 } 4599 4600 static void __noinline 4601 vfs_periodic_inactive(struct mount *mp, int flags) 4602 { 4603 struct vnode *vp, *mvp; 4604 int lkflags; 4605 4606 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4607 if (flags != MNT_WAIT) 4608 lkflags |= LK_NOWAIT; 4609 4610 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 4611 if ((vp->v_iflag & VI_DEFINACT) == 0) { 4612 VI_UNLOCK(vp); 4613 continue; 4614 } 4615 vp->v_iflag &= ~VI_DEFINACT; 4616 vfs_deferred_inactive(vp, lkflags); 4617 } 4618 } 4619 4620 static inline bool 4621 vfs_want_msync(struct vnode *vp) 4622 { 4623 struct vm_object *obj; 4624 4625 /* 4626 * This test may be performed without any locks held. 4627 * We rely on vm_object's type stability. 4628 */ 4629 if (vp->v_vflag & VV_NOSYNC) 4630 return (false); 4631 obj = vp->v_object; 4632 return (obj != NULL && vm_object_mightbedirty(obj)); 4633 } 4634 4635 static int 4636 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 4637 { 4638 4639 if (vp->v_vflag & VV_NOSYNC) 4640 return (false); 4641 if (vp->v_iflag & VI_DEFINACT) 4642 return (true); 4643 return (vfs_want_msync(vp)); 4644 } 4645 4646 static void __noinline 4647 vfs_periodic_msync_inactive(struct mount *mp, int flags) 4648 { 4649 struct vnode *vp, *mvp; 4650 struct vm_object *obj; 4651 struct thread *td; 4652 int lkflags, objflags; 4653 bool seen_defer; 4654 4655 td = curthread; 4656 4657 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4658 if (flags != MNT_WAIT) { 4659 lkflags |= LK_NOWAIT; 4660 objflags = OBJPC_NOSYNC; 4661 } else { 4662 objflags = OBJPC_SYNC; 4663 } 4664 4665 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 4666 seen_defer = false; 4667 if (vp->v_iflag & VI_DEFINACT) { 4668 vp->v_iflag &= ~VI_DEFINACT; 4669 seen_defer = true; 4670 } 4671 if (!vfs_want_msync(vp)) { 4672 if (seen_defer) 4673 vfs_deferred_inactive(vp, lkflags); 4674 else 4675 VI_UNLOCK(vp); 4676 continue; 4677 } 4678 if (vget(vp, lkflags) == 0) { 4679 obj = vp->v_object; 4680 if (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0) { 4681 VM_OBJECT_WLOCK(obj); 4682 vm_object_page_clean(obj, 0, 0, objflags); 4683 VM_OBJECT_WUNLOCK(obj); 4684 } 4685 vput(vp); 4686 if (seen_defer) 4687 vdrop(vp); 4688 } else { 4689 if (seen_defer) 4690 vdefer_inactive_unlocked(vp); 4691 } 4692 } 4693 } 4694 4695 void 4696 vfs_periodic(struct mount *mp, int flags) 4697 { 4698 4699 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4700 4701 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4702 vfs_periodic_inactive(mp, flags); 4703 else 4704 vfs_periodic_msync_inactive(mp, flags); 4705 } 4706 4707 static void 4708 destroy_vpollinfo_free(struct vpollinfo *vi) 4709 { 4710 4711 knlist_destroy(&vi->vpi_selinfo.si_note); 4712 mtx_destroy(&vi->vpi_lock); 4713 uma_zfree(vnodepoll_zone, vi); 4714 } 4715 4716 static void 4717 destroy_vpollinfo(struct vpollinfo *vi) 4718 { 4719 4720 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4721 seldrain(&vi->vpi_selinfo); 4722 destroy_vpollinfo_free(vi); 4723 } 4724 4725 /* 4726 * Initialize per-vnode helper structure to hold poll-related state. 4727 */ 4728 void 4729 v_addpollinfo(struct vnode *vp) 4730 { 4731 struct vpollinfo *vi; 4732 4733 if (vp->v_pollinfo != NULL) 4734 return; 4735 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4736 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4737 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4738 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4739 VI_LOCK(vp); 4740 if (vp->v_pollinfo != NULL) { 4741 VI_UNLOCK(vp); 4742 destroy_vpollinfo_free(vi); 4743 return; 4744 } 4745 vp->v_pollinfo = vi; 4746 VI_UNLOCK(vp); 4747 } 4748 4749 /* 4750 * Record a process's interest in events which might happen to 4751 * a vnode. Because poll uses the historic select-style interface 4752 * internally, this routine serves as both the ``check for any 4753 * pending events'' and the ``record my interest in future events'' 4754 * functions. (These are done together, while the lock is held, 4755 * to avoid race conditions.) 4756 */ 4757 int 4758 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4759 { 4760 4761 v_addpollinfo(vp); 4762 mtx_lock(&vp->v_pollinfo->vpi_lock); 4763 if (vp->v_pollinfo->vpi_revents & events) { 4764 /* 4765 * This leaves events we are not interested 4766 * in available for the other process which 4767 * which presumably had requested them 4768 * (otherwise they would never have been 4769 * recorded). 4770 */ 4771 events &= vp->v_pollinfo->vpi_revents; 4772 vp->v_pollinfo->vpi_revents &= ~events; 4773 4774 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4775 return (events); 4776 } 4777 vp->v_pollinfo->vpi_events |= events; 4778 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4779 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4780 return (0); 4781 } 4782 4783 /* 4784 * Routine to create and manage a filesystem syncer vnode. 4785 */ 4786 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4787 static int sync_fsync(struct vop_fsync_args *); 4788 static int sync_inactive(struct vop_inactive_args *); 4789 static int sync_reclaim(struct vop_reclaim_args *); 4790 4791 static struct vop_vector sync_vnodeops = { 4792 .vop_bypass = VOP_EOPNOTSUPP, 4793 .vop_close = sync_close, /* close */ 4794 .vop_fsync = sync_fsync, /* fsync */ 4795 .vop_inactive = sync_inactive, /* inactive */ 4796 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 4797 .vop_reclaim = sync_reclaim, /* reclaim */ 4798 .vop_lock1 = vop_stdlock, /* lock */ 4799 .vop_unlock = vop_stdunlock, /* unlock */ 4800 .vop_islocked = vop_stdislocked, /* islocked */ 4801 }; 4802 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 4803 4804 /* 4805 * Create a new filesystem syncer vnode for the specified mount point. 4806 */ 4807 void 4808 vfs_allocate_syncvnode(struct mount *mp) 4809 { 4810 struct vnode *vp; 4811 struct bufobj *bo; 4812 static long start, incr, next; 4813 int error; 4814 4815 /* Allocate a new vnode */ 4816 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4817 if (error != 0) 4818 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4819 vp->v_type = VNON; 4820 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4821 vp->v_vflag |= VV_FORCEINSMQ; 4822 error = insmntque(vp, mp); 4823 if (error != 0) 4824 panic("vfs_allocate_syncvnode: insmntque() failed"); 4825 vp->v_vflag &= ~VV_FORCEINSMQ; 4826 VOP_UNLOCK(vp); 4827 /* 4828 * Place the vnode onto the syncer worklist. We attempt to 4829 * scatter them about on the list so that they will go off 4830 * at evenly distributed times even if all the filesystems 4831 * are mounted at once. 4832 */ 4833 next += incr; 4834 if (next == 0 || next > syncer_maxdelay) { 4835 start /= 2; 4836 incr /= 2; 4837 if (start == 0) { 4838 start = syncer_maxdelay / 2; 4839 incr = syncer_maxdelay; 4840 } 4841 next = start; 4842 } 4843 bo = &vp->v_bufobj; 4844 BO_LOCK(bo); 4845 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4846 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4847 mtx_lock(&sync_mtx); 4848 sync_vnode_count++; 4849 if (mp->mnt_syncer == NULL) { 4850 mp->mnt_syncer = vp; 4851 vp = NULL; 4852 } 4853 mtx_unlock(&sync_mtx); 4854 BO_UNLOCK(bo); 4855 if (vp != NULL) { 4856 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4857 vgone(vp); 4858 vput(vp); 4859 } 4860 } 4861 4862 void 4863 vfs_deallocate_syncvnode(struct mount *mp) 4864 { 4865 struct vnode *vp; 4866 4867 mtx_lock(&sync_mtx); 4868 vp = mp->mnt_syncer; 4869 if (vp != NULL) 4870 mp->mnt_syncer = NULL; 4871 mtx_unlock(&sync_mtx); 4872 if (vp != NULL) 4873 vrele(vp); 4874 } 4875 4876 /* 4877 * Do a lazy sync of the filesystem. 4878 */ 4879 static int 4880 sync_fsync(struct vop_fsync_args *ap) 4881 { 4882 struct vnode *syncvp = ap->a_vp; 4883 struct mount *mp = syncvp->v_mount; 4884 int error, save; 4885 struct bufobj *bo; 4886 4887 /* 4888 * We only need to do something if this is a lazy evaluation. 4889 */ 4890 if (ap->a_waitfor != MNT_LAZY) 4891 return (0); 4892 4893 /* 4894 * Move ourselves to the back of the sync list. 4895 */ 4896 bo = &syncvp->v_bufobj; 4897 BO_LOCK(bo); 4898 vn_syncer_add_to_worklist(bo, syncdelay); 4899 BO_UNLOCK(bo); 4900 4901 /* 4902 * Walk the list of vnodes pushing all that are dirty and 4903 * not already on the sync list. 4904 */ 4905 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4906 return (0); 4907 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4908 vfs_unbusy(mp); 4909 return (0); 4910 } 4911 save = curthread_pflags_set(TDP_SYNCIO); 4912 /* 4913 * The filesystem at hand may be idle with free vnodes stored in the 4914 * batch. Return them instead of letting them stay there indefinitely. 4915 */ 4916 vfs_periodic(mp, MNT_NOWAIT); 4917 error = VFS_SYNC(mp, MNT_LAZY); 4918 curthread_pflags_restore(save); 4919 vn_finished_write(mp); 4920 vfs_unbusy(mp); 4921 return (error); 4922 } 4923 4924 /* 4925 * The syncer vnode is no referenced. 4926 */ 4927 static int 4928 sync_inactive(struct vop_inactive_args *ap) 4929 { 4930 4931 vgone(ap->a_vp); 4932 return (0); 4933 } 4934 4935 /* 4936 * The syncer vnode is no longer needed and is being decommissioned. 4937 * 4938 * Modifications to the worklist must be protected by sync_mtx. 4939 */ 4940 static int 4941 sync_reclaim(struct vop_reclaim_args *ap) 4942 { 4943 struct vnode *vp = ap->a_vp; 4944 struct bufobj *bo; 4945 4946 bo = &vp->v_bufobj; 4947 BO_LOCK(bo); 4948 mtx_lock(&sync_mtx); 4949 if (vp->v_mount->mnt_syncer == vp) 4950 vp->v_mount->mnt_syncer = NULL; 4951 if (bo->bo_flag & BO_ONWORKLST) { 4952 LIST_REMOVE(bo, bo_synclist); 4953 syncer_worklist_len--; 4954 sync_vnode_count--; 4955 bo->bo_flag &= ~BO_ONWORKLST; 4956 } 4957 mtx_unlock(&sync_mtx); 4958 BO_UNLOCK(bo); 4959 4960 return (0); 4961 } 4962 4963 int 4964 vn_need_pageq_flush(struct vnode *vp) 4965 { 4966 struct vm_object *obj; 4967 int need; 4968 4969 MPASS(mtx_owned(VI_MTX(vp))); 4970 need = 0; 4971 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 4972 vm_object_mightbedirty(obj)) 4973 need = 1; 4974 return (need); 4975 } 4976 4977 /* 4978 * Check if vnode represents a disk device 4979 */ 4980 int 4981 vn_isdisk(struct vnode *vp, int *errp) 4982 { 4983 int error; 4984 4985 if (vp->v_type != VCHR) { 4986 error = ENOTBLK; 4987 goto out; 4988 } 4989 error = 0; 4990 dev_lock(); 4991 if (vp->v_rdev == NULL) 4992 error = ENXIO; 4993 else if (vp->v_rdev->si_devsw == NULL) 4994 error = ENXIO; 4995 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4996 error = ENOTBLK; 4997 dev_unlock(); 4998 out: 4999 if (errp != NULL) 5000 *errp = error; 5001 return (error == 0); 5002 } 5003 5004 /* 5005 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see 5006 * the comment above cache_fplookup for details. 5007 * 5008 * We never deny as priv_check_cred calls are not yet supported, see vaccess. 5009 */ 5010 int 5011 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred) 5012 { 5013 5014 VFS_SMR_ASSERT_ENTERED(); 5015 5016 /* Check the owner. */ 5017 if (cred->cr_uid == file_uid) { 5018 if (file_mode & S_IXUSR) 5019 return (0); 5020 return (EAGAIN); 5021 } 5022 5023 /* Otherwise, check the groups (first match) */ 5024 if (groupmember(file_gid, cred)) { 5025 if (file_mode & S_IXGRP) 5026 return (0); 5027 return (EAGAIN); 5028 } 5029 5030 /* Otherwise, check everyone else. */ 5031 if (file_mode & S_IXOTH) 5032 return (0); 5033 return (EAGAIN); 5034 } 5035 5036 /* 5037 * Common filesystem object access control check routine. Accepts a 5038 * vnode's type, "mode", uid and gid, requested access mode, and credentials. 5039 * Returns 0 on success, or an errno on failure. 5040 */ 5041 int 5042 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5043 accmode_t accmode, struct ucred *cred) 5044 { 5045 accmode_t dac_granted; 5046 accmode_t priv_granted; 5047 5048 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5049 ("invalid bit in accmode")); 5050 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5051 ("VAPPEND without VWRITE")); 5052 5053 /* 5054 * Look for a normal, non-privileged way to access the file/directory 5055 * as requested. If it exists, go with that. 5056 */ 5057 5058 dac_granted = 0; 5059 5060 /* Check the owner. */ 5061 if (cred->cr_uid == file_uid) { 5062 dac_granted |= VADMIN; 5063 if (file_mode & S_IXUSR) 5064 dac_granted |= VEXEC; 5065 if (file_mode & S_IRUSR) 5066 dac_granted |= VREAD; 5067 if (file_mode & S_IWUSR) 5068 dac_granted |= (VWRITE | VAPPEND); 5069 5070 if ((accmode & dac_granted) == accmode) 5071 return (0); 5072 5073 goto privcheck; 5074 } 5075 5076 /* Otherwise, check the groups (first match) */ 5077 if (groupmember(file_gid, cred)) { 5078 if (file_mode & S_IXGRP) 5079 dac_granted |= VEXEC; 5080 if (file_mode & S_IRGRP) 5081 dac_granted |= VREAD; 5082 if (file_mode & S_IWGRP) 5083 dac_granted |= (VWRITE | VAPPEND); 5084 5085 if ((accmode & dac_granted) == accmode) 5086 return (0); 5087 5088 goto privcheck; 5089 } 5090 5091 /* Otherwise, check everyone else. */ 5092 if (file_mode & S_IXOTH) 5093 dac_granted |= VEXEC; 5094 if (file_mode & S_IROTH) 5095 dac_granted |= VREAD; 5096 if (file_mode & S_IWOTH) 5097 dac_granted |= (VWRITE | VAPPEND); 5098 if ((accmode & dac_granted) == accmode) 5099 return (0); 5100 5101 privcheck: 5102 /* 5103 * Build a privilege mask to determine if the set of privileges 5104 * satisfies the requirements when combined with the granted mask 5105 * from above. For each privilege, if the privilege is required, 5106 * bitwise or the request type onto the priv_granted mask. 5107 */ 5108 priv_granted = 0; 5109 5110 if (type == VDIR) { 5111 /* 5112 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5113 * requests, instead of PRIV_VFS_EXEC. 5114 */ 5115 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5116 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5117 priv_granted |= VEXEC; 5118 } else { 5119 /* 5120 * Ensure that at least one execute bit is on. Otherwise, 5121 * a privileged user will always succeed, and we don't want 5122 * this to happen unless the file really is executable. 5123 */ 5124 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5125 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5126 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5127 priv_granted |= VEXEC; 5128 } 5129 5130 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5131 !priv_check_cred(cred, PRIV_VFS_READ)) 5132 priv_granted |= VREAD; 5133 5134 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5135 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5136 priv_granted |= (VWRITE | VAPPEND); 5137 5138 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5139 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5140 priv_granted |= VADMIN; 5141 5142 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5143 return (0); 5144 } 5145 5146 return ((accmode & VADMIN) ? EPERM : EACCES); 5147 } 5148 5149 /* 5150 * Credential check based on process requesting service, and per-attribute 5151 * permissions. 5152 */ 5153 int 5154 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5155 struct thread *td, accmode_t accmode) 5156 { 5157 5158 /* 5159 * Kernel-invoked always succeeds. 5160 */ 5161 if (cred == NOCRED) 5162 return (0); 5163 5164 /* 5165 * Do not allow privileged processes in jail to directly manipulate 5166 * system attributes. 5167 */ 5168 switch (attrnamespace) { 5169 case EXTATTR_NAMESPACE_SYSTEM: 5170 /* Potentially should be: return (EPERM); */ 5171 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5172 case EXTATTR_NAMESPACE_USER: 5173 return (VOP_ACCESS(vp, accmode, cred, td)); 5174 default: 5175 return (EPERM); 5176 } 5177 } 5178 5179 #ifdef DEBUG_VFS_LOCKS 5180 /* 5181 * This only exists to suppress warnings from unlocked specfs accesses. It is 5182 * no longer ok to have an unlocked VFS. 5183 */ 5184 #define IGNORE_LOCK(vp) (KERNEL_PANICKED() || (vp) == NULL || \ 5185 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 5186 5187 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5188 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5189 "Drop into debugger on lock violation"); 5190 5191 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5192 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5193 0, "Check for interlock across VOPs"); 5194 5195 int vfs_badlock_print = 1; /* Print lock violations. */ 5196 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5197 0, "Print lock violations"); 5198 5199 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5200 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5201 0, "Print vnode details on lock violations"); 5202 5203 #ifdef KDB 5204 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5205 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5206 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5207 #endif 5208 5209 static void 5210 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5211 { 5212 5213 #ifdef KDB 5214 if (vfs_badlock_backtrace) 5215 kdb_backtrace(); 5216 #endif 5217 if (vfs_badlock_vnode) 5218 vn_printf(vp, "vnode "); 5219 if (vfs_badlock_print) 5220 printf("%s: %p %s\n", str, (void *)vp, msg); 5221 if (vfs_badlock_ddb) 5222 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5223 } 5224 5225 void 5226 assert_vi_locked(struct vnode *vp, const char *str) 5227 { 5228 5229 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5230 vfs_badlock("interlock is not locked but should be", str, vp); 5231 } 5232 5233 void 5234 assert_vi_unlocked(struct vnode *vp, const char *str) 5235 { 5236 5237 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5238 vfs_badlock("interlock is locked but should not be", str, vp); 5239 } 5240 5241 void 5242 assert_vop_locked(struct vnode *vp, const char *str) 5243 { 5244 int locked; 5245 5246 if (!IGNORE_LOCK(vp)) { 5247 locked = VOP_ISLOCKED(vp); 5248 if (locked == 0 || locked == LK_EXCLOTHER) 5249 vfs_badlock("is not locked but should be", str, vp); 5250 } 5251 } 5252 5253 void 5254 assert_vop_unlocked(struct vnode *vp, const char *str) 5255 { 5256 5257 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5258 vfs_badlock("is locked but should not be", str, vp); 5259 } 5260 5261 void 5262 assert_vop_elocked(struct vnode *vp, const char *str) 5263 { 5264 5265 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5266 vfs_badlock("is not exclusive locked but should be", str, vp); 5267 } 5268 #endif /* DEBUG_VFS_LOCKS */ 5269 5270 void 5271 vop_rename_fail(struct vop_rename_args *ap) 5272 { 5273 5274 if (ap->a_tvp != NULL) 5275 vput(ap->a_tvp); 5276 if (ap->a_tdvp == ap->a_tvp) 5277 vrele(ap->a_tdvp); 5278 else 5279 vput(ap->a_tdvp); 5280 vrele(ap->a_fdvp); 5281 vrele(ap->a_fvp); 5282 } 5283 5284 void 5285 vop_rename_pre(void *ap) 5286 { 5287 struct vop_rename_args *a = ap; 5288 5289 #ifdef DEBUG_VFS_LOCKS 5290 if (a->a_tvp) 5291 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5292 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5293 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5294 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5295 5296 /* Check the source (from). */ 5297 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5298 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5299 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5300 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5301 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5302 5303 /* Check the target. */ 5304 if (a->a_tvp) 5305 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5306 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5307 #endif 5308 /* 5309 * It may be tempting to add vn_seqc_write_begin/end calls here and 5310 * in vop_rename_post but that's not going to work out since some 5311 * filesystems relookup vnodes mid-rename. This is probably a bug. 5312 * 5313 * For now filesystems are expected to do the relevant calls after they 5314 * decide what vnodes to operate on. 5315 */ 5316 if (a->a_tdvp != a->a_fdvp) 5317 vhold(a->a_fdvp); 5318 if (a->a_tvp != a->a_fvp) 5319 vhold(a->a_fvp); 5320 vhold(a->a_tdvp); 5321 if (a->a_tvp) 5322 vhold(a->a_tvp); 5323 } 5324 5325 #ifdef DEBUG_VFS_LOCKS 5326 void 5327 vop_fplookup_vexec_debugpre(void *ap __unused) 5328 { 5329 5330 VFS_SMR_ASSERT_ENTERED(); 5331 } 5332 5333 void 5334 vop_fplookup_vexec_debugpost(void *ap __unused, int rc __unused) 5335 { 5336 5337 VFS_SMR_ASSERT_ENTERED(); 5338 } 5339 5340 void 5341 vop_strategy_debugpre(void *ap) 5342 { 5343 struct vop_strategy_args *a; 5344 struct buf *bp; 5345 5346 a = ap; 5347 bp = a->a_bp; 5348 5349 /* 5350 * Cluster ops lock their component buffers but not the IO container. 5351 */ 5352 if ((bp->b_flags & B_CLUSTER) != 0) 5353 return; 5354 5355 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5356 if (vfs_badlock_print) 5357 printf( 5358 "VOP_STRATEGY: bp is not locked but should be\n"); 5359 if (vfs_badlock_ddb) 5360 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5361 } 5362 } 5363 5364 void 5365 vop_lock_debugpre(void *ap) 5366 { 5367 struct vop_lock1_args *a = ap; 5368 5369 if ((a->a_flags & LK_INTERLOCK) == 0) 5370 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5371 else 5372 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5373 } 5374 5375 void 5376 vop_lock_debugpost(void *ap, int rc) 5377 { 5378 struct vop_lock1_args *a = ap; 5379 5380 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5381 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5382 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5383 } 5384 5385 void 5386 vop_unlock_debugpre(void *ap) 5387 { 5388 struct vop_unlock_args *a = ap; 5389 5390 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5391 } 5392 5393 void 5394 vop_need_inactive_debugpre(void *ap) 5395 { 5396 struct vop_need_inactive_args *a = ap; 5397 5398 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5399 } 5400 5401 void 5402 vop_need_inactive_debugpost(void *ap, int rc) 5403 { 5404 struct vop_need_inactive_args *a = ap; 5405 5406 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5407 } 5408 #endif 5409 5410 void 5411 vop_create_pre(void *ap) 5412 { 5413 struct vop_create_args *a; 5414 struct vnode *dvp; 5415 5416 a = ap; 5417 dvp = a->a_dvp; 5418 vn_seqc_write_begin(dvp); 5419 } 5420 5421 void 5422 vop_create_post(void *ap, int rc) 5423 { 5424 struct vop_create_args *a; 5425 struct vnode *dvp; 5426 5427 a = ap; 5428 dvp = a->a_dvp; 5429 vn_seqc_write_end(dvp); 5430 if (!rc) 5431 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5432 } 5433 5434 void 5435 vop_whiteout_pre(void *ap) 5436 { 5437 struct vop_whiteout_args *a; 5438 struct vnode *dvp; 5439 5440 a = ap; 5441 dvp = a->a_dvp; 5442 vn_seqc_write_begin(dvp); 5443 } 5444 5445 void 5446 vop_whiteout_post(void *ap, int rc) 5447 { 5448 struct vop_whiteout_args *a; 5449 struct vnode *dvp; 5450 5451 a = ap; 5452 dvp = a->a_dvp; 5453 vn_seqc_write_end(dvp); 5454 } 5455 5456 void 5457 vop_deleteextattr_pre(void *ap) 5458 { 5459 struct vop_deleteextattr_args *a; 5460 struct vnode *vp; 5461 5462 a = ap; 5463 vp = a->a_vp; 5464 vn_seqc_write_begin(vp); 5465 } 5466 5467 void 5468 vop_deleteextattr_post(void *ap, int rc) 5469 { 5470 struct vop_deleteextattr_args *a; 5471 struct vnode *vp; 5472 5473 a = ap; 5474 vp = a->a_vp; 5475 vn_seqc_write_end(vp); 5476 if (!rc) 5477 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5478 } 5479 5480 void 5481 vop_link_pre(void *ap) 5482 { 5483 struct vop_link_args *a; 5484 struct vnode *vp, *tdvp; 5485 5486 a = ap; 5487 vp = a->a_vp; 5488 tdvp = a->a_tdvp; 5489 vn_seqc_write_begin(vp); 5490 vn_seqc_write_begin(tdvp); 5491 } 5492 5493 void 5494 vop_link_post(void *ap, int rc) 5495 { 5496 struct vop_link_args *a; 5497 struct vnode *vp, *tdvp; 5498 5499 a = ap; 5500 vp = a->a_vp; 5501 tdvp = a->a_tdvp; 5502 vn_seqc_write_end(vp); 5503 vn_seqc_write_end(tdvp); 5504 if (!rc) { 5505 VFS_KNOTE_LOCKED(vp, NOTE_LINK); 5506 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE); 5507 } 5508 } 5509 5510 void 5511 vop_mkdir_pre(void *ap) 5512 { 5513 struct vop_mkdir_args *a; 5514 struct vnode *dvp; 5515 5516 a = ap; 5517 dvp = a->a_dvp; 5518 vn_seqc_write_begin(dvp); 5519 } 5520 5521 void 5522 vop_mkdir_post(void *ap, int rc) 5523 { 5524 struct vop_mkdir_args *a; 5525 struct vnode *dvp; 5526 5527 a = ap; 5528 dvp = a->a_dvp; 5529 vn_seqc_write_end(dvp); 5530 if (!rc) 5531 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 5532 } 5533 5534 void 5535 vop_mknod_pre(void *ap) 5536 { 5537 struct vop_mknod_args *a; 5538 struct vnode *dvp; 5539 5540 a = ap; 5541 dvp = a->a_dvp; 5542 vn_seqc_write_begin(dvp); 5543 } 5544 5545 void 5546 vop_mknod_post(void *ap, int rc) 5547 { 5548 struct vop_mknod_args *a; 5549 struct vnode *dvp; 5550 5551 a = ap; 5552 dvp = a->a_dvp; 5553 vn_seqc_write_end(dvp); 5554 if (!rc) 5555 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5556 } 5557 5558 void 5559 vop_reclaim_post(void *ap, int rc) 5560 { 5561 struct vop_reclaim_args *a; 5562 struct vnode *vp; 5563 5564 a = ap; 5565 vp = a->a_vp; 5566 ASSERT_VOP_IN_SEQC(vp); 5567 if (!rc) 5568 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE); 5569 } 5570 5571 void 5572 vop_remove_pre(void *ap) 5573 { 5574 struct vop_remove_args *a; 5575 struct vnode *dvp, *vp; 5576 5577 a = ap; 5578 dvp = a->a_dvp; 5579 vp = a->a_vp; 5580 vn_seqc_write_begin(dvp); 5581 vn_seqc_write_begin(vp); 5582 } 5583 5584 void 5585 vop_remove_post(void *ap, int rc) 5586 { 5587 struct vop_remove_args *a; 5588 struct vnode *dvp, *vp; 5589 5590 a = ap; 5591 dvp = a->a_dvp; 5592 vp = a->a_vp; 5593 vn_seqc_write_end(dvp); 5594 vn_seqc_write_end(vp); 5595 if (!rc) { 5596 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5597 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 5598 } 5599 } 5600 5601 void 5602 vop_rename_post(void *ap, int rc) 5603 { 5604 struct vop_rename_args *a = ap; 5605 long hint; 5606 5607 if (!rc) { 5608 hint = NOTE_WRITE; 5609 if (a->a_fdvp == a->a_tdvp) { 5610 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5611 hint |= NOTE_LINK; 5612 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5613 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5614 } else { 5615 hint |= NOTE_EXTEND; 5616 if (a->a_fvp->v_type == VDIR) 5617 hint |= NOTE_LINK; 5618 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5619 5620 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5621 a->a_tvp->v_type == VDIR) 5622 hint &= ~NOTE_LINK; 5623 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5624 } 5625 5626 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5627 if (a->a_tvp) 5628 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5629 } 5630 if (a->a_tdvp != a->a_fdvp) 5631 vdrop(a->a_fdvp); 5632 if (a->a_tvp != a->a_fvp) 5633 vdrop(a->a_fvp); 5634 vdrop(a->a_tdvp); 5635 if (a->a_tvp) 5636 vdrop(a->a_tvp); 5637 } 5638 5639 void 5640 vop_rmdir_pre(void *ap) 5641 { 5642 struct vop_rmdir_args *a; 5643 struct vnode *dvp, *vp; 5644 5645 a = ap; 5646 dvp = a->a_dvp; 5647 vp = a->a_vp; 5648 vn_seqc_write_begin(dvp); 5649 vn_seqc_write_begin(vp); 5650 } 5651 5652 void 5653 vop_rmdir_post(void *ap, int rc) 5654 { 5655 struct vop_rmdir_args *a; 5656 struct vnode *dvp, *vp; 5657 5658 a = ap; 5659 dvp = a->a_dvp; 5660 vp = a->a_vp; 5661 vn_seqc_write_end(dvp); 5662 vn_seqc_write_end(vp); 5663 if (!rc) { 5664 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 5665 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 5666 } 5667 } 5668 5669 void 5670 vop_setattr_pre(void *ap) 5671 { 5672 struct vop_setattr_args *a; 5673 struct vnode *vp; 5674 5675 a = ap; 5676 vp = a->a_vp; 5677 vn_seqc_write_begin(vp); 5678 } 5679 5680 void 5681 vop_setattr_post(void *ap, int rc) 5682 { 5683 struct vop_setattr_args *a; 5684 struct vnode *vp; 5685 5686 a = ap; 5687 vp = a->a_vp; 5688 vn_seqc_write_end(vp); 5689 if (!rc) 5690 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 5691 } 5692 5693 void 5694 vop_setacl_pre(void *ap) 5695 { 5696 struct vop_setacl_args *a; 5697 struct vnode *vp; 5698 5699 a = ap; 5700 vp = a->a_vp; 5701 vn_seqc_write_begin(vp); 5702 } 5703 5704 void 5705 vop_setacl_post(void *ap, int rc __unused) 5706 { 5707 struct vop_setacl_args *a; 5708 struct vnode *vp; 5709 5710 a = ap; 5711 vp = a->a_vp; 5712 vn_seqc_write_end(vp); 5713 } 5714 5715 void 5716 vop_setextattr_pre(void *ap) 5717 { 5718 struct vop_setextattr_args *a; 5719 struct vnode *vp; 5720 5721 a = ap; 5722 vp = a->a_vp; 5723 vn_seqc_write_begin(vp); 5724 } 5725 5726 void 5727 vop_setextattr_post(void *ap, int rc) 5728 { 5729 struct vop_setextattr_args *a; 5730 struct vnode *vp; 5731 5732 a = ap; 5733 vp = a->a_vp; 5734 vn_seqc_write_end(vp); 5735 if (!rc) 5736 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 5737 } 5738 5739 void 5740 vop_symlink_pre(void *ap) 5741 { 5742 struct vop_symlink_args *a; 5743 struct vnode *dvp; 5744 5745 a = ap; 5746 dvp = a->a_dvp; 5747 vn_seqc_write_begin(dvp); 5748 } 5749 5750 void 5751 vop_symlink_post(void *ap, int rc) 5752 { 5753 struct vop_symlink_args *a; 5754 struct vnode *dvp; 5755 5756 a = ap; 5757 dvp = a->a_dvp; 5758 vn_seqc_write_end(dvp); 5759 if (!rc) 5760 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5761 } 5762 5763 void 5764 vop_open_post(void *ap, int rc) 5765 { 5766 struct vop_open_args *a = ap; 5767 5768 if (!rc) 5769 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5770 } 5771 5772 void 5773 vop_close_post(void *ap, int rc) 5774 { 5775 struct vop_close_args *a = ap; 5776 5777 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5778 !VN_IS_DOOMED(a->a_vp))) { 5779 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5780 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5781 } 5782 } 5783 5784 void 5785 vop_read_post(void *ap, int rc) 5786 { 5787 struct vop_read_args *a = ap; 5788 5789 if (!rc) 5790 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5791 } 5792 5793 void 5794 vop_readdir_post(void *ap, int rc) 5795 { 5796 struct vop_readdir_args *a = ap; 5797 5798 if (!rc) 5799 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5800 } 5801 5802 static struct knlist fs_knlist; 5803 5804 static void 5805 vfs_event_init(void *arg) 5806 { 5807 knlist_init_mtx(&fs_knlist, NULL); 5808 } 5809 /* XXX - correct order? */ 5810 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5811 5812 void 5813 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5814 { 5815 5816 KNOTE_UNLOCKED(&fs_knlist, event); 5817 } 5818 5819 static int filt_fsattach(struct knote *kn); 5820 static void filt_fsdetach(struct knote *kn); 5821 static int filt_fsevent(struct knote *kn, long hint); 5822 5823 struct filterops fs_filtops = { 5824 .f_isfd = 0, 5825 .f_attach = filt_fsattach, 5826 .f_detach = filt_fsdetach, 5827 .f_event = filt_fsevent 5828 }; 5829 5830 static int 5831 filt_fsattach(struct knote *kn) 5832 { 5833 5834 kn->kn_flags |= EV_CLEAR; 5835 knlist_add(&fs_knlist, kn, 0); 5836 return (0); 5837 } 5838 5839 static void 5840 filt_fsdetach(struct knote *kn) 5841 { 5842 5843 knlist_remove(&fs_knlist, kn, 0); 5844 } 5845 5846 static int 5847 filt_fsevent(struct knote *kn, long hint) 5848 { 5849 5850 kn->kn_fflags |= hint; 5851 return (kn->kn_fflags != 0); 5852 } 5853 5854 static int 5855 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5856 { 5857 struct vfsidctl vc; 5858 int error; 5859 struct mount *mp; 5860 5861 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5862 if (error) 5863 return (error); 5864 if (vc.vc_vers != VFS_CTL_VERS1) 5865 return (EINVAL); 5866 mp = vfs_getvfs(&vc.vc_fsid); 5867 if (mp == NULL) 5868 return (ENOENT); 5869 /* ensure that a specific sysctl goes to the right filesystem. */ 5870 if (strcmp(vc.vc_fstypename, "*") != 0 && 5871 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5872 vfs_rel(mp); 5873 return (EINVAL); 5874 } 5875 VCTLTOREQ(&vc, req); 5876 error = VFS_SYSCTL(mp, vc.vc_op, req); 5877 vfs_rel(mp); 5878 return (error); 5879 } 5880 5881 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 5882 NULL, 0, sysctl_vfs_ctl, "", 5883 "Sysctl by fsid"); 5884 5885 /* 5886 * Function to initialize a va_filerev field sensibly. 5887 * XXX: Wouldn't a random number make a lot more sense ?? 5888 */ 5889 u_quad_t 5890 init_va_filerev(void) 5891 { 5892 struct bintime bt; 5893 5894 getbinuptime(&bt); 5895 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5896 } 5897 5898 static int filt_vfsread(struct knote *kn, long hint); 5899 static int filt_vfswrite(struct knote *kn, long hint); 5900 static int filt_vfsvnode(struct knote *kn, long hint); 5901 static void filt_vfsdetach(struct knote *kn); 5902 static struct filterops vfsread_filtops = { 5903 .f_isfd = 1, 5904 .f_detach = filt_vfsdetach, 5905 .f_event = filt_vfsread 5906 }; 5907 static struct filterops vfswrite_filtops = { 5908 .f_isfd = 1, 5909 .f_detach = filt_vfsdetach, 5910 .f_event = filt_vfswrite 5911 }; 5912 static struct filterops vfsvnode_filtops = { 5913 .f_isfd = 1, 5914 .f_detach = filt_vfsdetach, 5915 .f_event = filt_vfsvnode 5916 }; 5917 5918 static void 5919 vfs_knllock(void *arg) 5920 { 5921 struct vnode *vp = arg; 5922 5923 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5924 } 5925 5926 static void 5927 vfs_knlunlock(void *arg) 5928 { 5929 struct vnode *vp = arg; 5930 5931 VOP_UNLOCK(vp); 5932 } 5933 5934 static void 5935 vfs_knl_assert_locked(void *arg) 5936 { 5937 #ifdef DEBUG_VFS_LOCKS 5938 struct vnode *vp = arg; 5939 5940 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5941 #endif 5942 } 5943 5944 static void 5945 vfs_knl_assert_unlocked(void *arg) 5946 { 5947 #ifdef DEBUG_VFS_LOCKS 5948 struct vnode *vp = arg; 5949 5950 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5951 #endif 5952 } 5953 5954 int 5955 vfs_kqfilter(struct vop_kqfilter_args *ap) 5956 { 5957 struct vnode *vp = ap->a_vp; 5958 struct knote *kn = ap->a_kn; 5959 struct knlist *knl; 5960 5961 switch (kn->kn_filter) { 5962 case EVFILT_READ: 5963 kn->kn_fop = &vfsread_filtops; 5964 break; 5965 case EVFILT_WRITE: 5966 kn->kn_fop = &vfswrite_filtops; 5967 break; 5968 case EVFILT_VNODE: 5969 kn->kn_fop = &vfsvnode_filtops; 5970 break; 5971 default: 5972 return (EINVAL); 5973 } 5974 5975 kn->kn_hook = (caddr_t)vp; 5976 5977 v_addpollinfo(vp); 5978 if (vp->v_pollinfo == NULL) 5979 return (ENOMEM); 5980 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5981 vhold(vp); 5982 knlist_add(knl, kn, 0); 5983 5984 return (0); 5985 } 5986 5987 /* 5988 * Detach knote from vnode 5989 */ 5990 static void 5991 filt_vfsdetach(struct knote *kn) 5992 { 5993 struct vnode *vp = (struct vnode *)kn->kn_hook; 5994 5995 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5996 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5997 vdrop(vp); 5998 } 5999 6000 /*ARGSUSED*/ 6001 static int 6002 filt_vfsread(struct knote *kn, long hint) 6003 { 6004 struct vnode *vp = (struct vnode *)kn->kn_hook; 6005 struct vattr va; 6006 int res; 6007 6008 /* 6009 * filesystem is gone, so set the EOF flag and schedule 6010 * the knote for deletion. 6011 */ 6012 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6013 VI_LOCK(vp); 6014 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6015 VI_UNLOCK(vp); 6016 return (1); 6017 } 6018 6019 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 6020 return (0); 6021 6022 VI_LOCK(vp); 6023 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 6024 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 6025 VI_UNLOCK(vp); 6026 return (res); 6027 } 6028 6029 /*ARGSUSED*/ 6030 static int 6031 filt_vfswrite(struct knote *kn, long hint) 6032 { 6033 struct vnode *vp = (struct vnode *)kn->kn_hook; 6034 6035 VI_LOCK(vp); 6036 6037 /* 6038 * filesystem is gone, so set the EOF flag and schedule 6039 * the knote for deletion. 6040 */ 6041 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 6042 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6043 6044 kn->kn_data = 0; 6045 VI_UNLOCK(vp); 6046 return (1); 6047 } 6048 6049 static int 6050 filt_vfsvnode(struct knote *kn, long hint) 6051 { 6052 struct vnode *vp = (struct vnode *)kn->kn_hook; 6053 int res; 6054 6055 VI_LOCK(vp); 6056 if (kn->kn_sfflags & hint) 6057 kn->kn_fflags |= hint; 6058 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6059 kn->kn_flags |= EV_EOF; 6060 VI_UNLOCK(vp); 6061 return (1); 6062 } 6063 res = (kn->kn_fflags != 0); 6064 VI_UNLOCK(vp); 6065 return (res); 6066 } 6067 6068 /* 6069 * Returns whether the directory is empty or not. 6070 * If it is empty, the return value is 0; otherwise 6071 * the return value is an error value (which may 6072 * be ENOTEMPTY). 6073 */ 6074 int 6075 vfs_emptydir(struct vnode *vp) 6076 { 6077 struct uio uio; 6078 struct iovec iov; 6079 struct dirent *dirent, *dp, *endp; 6080 int error, eof; 6081 6082 error = 0; 6083 eof = 0; 6084 6085 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 6086 6087 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 6088 iov.iov_base = dirent; 6089 iov.iov_len = sizeof(struct dirent); 6090 6091 uio.uio_iov = &iov; 6092 uio.uio_iovcnt = 1; 6093 uio.uio_offset = 0; 6094 uio.uio_resid = sizeof(struct dirent); 6095 uio.uio_segflg = UIO_SYSSPACE; 6096 uio.uio_rw = UIO_READ; 6097 uio.uio_td = curthread; 6098 6099 while (eof == 0 && error == 0) { 6100 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 6101 NULL, NULL); 6102 if (error != 0) 6103 break; 6104 endp = (void *)((uint8_t *)dirent + 6105 sizeof(struct dirent) - uio.uio_resid); 6106 for (dp = dirent; dp < endp; 6107 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 6108 if (dp->d_type == DT_WHT) 6109 continue; 6110 if (dp->d_namlen == 0) 6111 continue; 6112 if (dp->d_type != DT_DIR && 6113 dp->d_type != DT_UNKNOWN) { 6114 error = ENOTEMPTY; 6115 break; 6116 } 6117 if (dp->d_namlen > 2) { 6118 error = ENOTEMPTY; 6119 break; 6120 } 6121 if (dp->d_namlen == 1 && 6122 dp->d_name[0] != '.') { 6123 error = ENOTEMPTY; 6124 break; 6125 } 6126 if (dp->d_namlen == 2 && 6127 dp->d_name[1] != '.') { 6128 error = ENOTEMPTY; 6129 break; 6130 } 6131 uio.uio_resid = sizeof(struct dirent); 6132 } 6133 } 6134 free(dirent, M_TEMP); 6135 return (error); 6136 } 6137 6138 int 6139 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 6140 { 6141 int error; 6142 6143 if (dp->d_reclen > ap->a_uio->uio_resid) 6144 return (ENAMETOOLONG); 6145 error = uiomove(dp, dp->d_reclen, ap->a_uio); 6146 if (error) { 6147 if (ap->a_ncookies != NULL) { 6148 if (ap->a_cookies != NULL) 6149 free(ap->a_cookies, M_TEMP); 6150 ap->a_cookies = NULL; 6151 *ap->a_ncookies = 0; 6152 } 6153 return (error); 6154 } 6155 if (ap->a_ncookies == NULL) 6156 return (0); 6157 6158 KASSERT(ap->a_cookies, 6159 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 6160 6161 *ap->a_cookies = realloc(*ap->a_cookies, 6162 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 6163 (*ap->a_cookies)[*ap->a_ncookies] = off; 6164 *ap->a_ncookies += 1; 6165 return (0); 6166 } 6167 6168 /* 6169 * The purpose of this routine is to remove granularity from accmode_t, 6170 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 6171 * VADMIN and VAPPEND. 6172 * 6173 * If it returns 0, the caller is supposed to continue with the usual 6174 * access checks using 'accmode' as modified by this routine. If it 6175 * returns nonzero value, the caller is supposed to return that value 6176 * as errno. 6177 * 6178 * Note that after this routine runs, accmode may be zero. 6179 */ 6180 int 6181 vfs_unixify_accmode(accmode_t *accmode) 6182 { 6183 /* 6184 * There is no way to specify explicit "deny" rule using 6185 * file mode or POSIX.1e ACLs. 6186 */ 6187 if (*accmode & VEXPLICIT_DENY) { 6188 *accmode = 0; 6189 return (0); 6190 } 6191 6192 /* 6193 * None of these can be translated into usual access bits. 6194 * Also, the common case for NFSv4 ACLs is to not contain 6195 * either of these bits. Caller should check for VWRITE 6196 * on the containing directory instead. 6197 */ 6198 if (*accmode & (VDELETE_CHILD | VDELETE)) 6199 return (EPERM); 6200 6201 if (*accmode & VADMIN_PERMS) { 6202 *accmode &= ~VADMIN_PERMS; 6203 *accmode |= VADMIN; 6204 } 6205 6206 /* 6207 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6208 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6209 */ 6210 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6211 6212 return (0); 6213 } 6214 6215 /* 6216 * Clear out a doomed vnode (if any) and replace it with a new one as long 6217 * as the fs is not being unmounted. Return the root vnode to the caller. 6218 */ 6219 static int __noinline 6220 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6221 { 6222 struct vnode *vp; 6223 int error; 6224 6225 restart: 6226 if (mp->mnt_rootvnode != NULL) { 6227 MNT_ILOCK(mp); 6228 vp = mp->mnt_rootvnode; 6229 if (vp != NULL) { 6230 if (!VN_IS_DOOMED(vp)) { 6231 vrefact(vp); 6232 MNT_IUNLOCK(mp); 6233 error = vn_lock(vp, flags); 6234 if (error == 0) { 6235 *vpp = vp; 6236 return (0); 6237 } 6238 vrele(vp); 6239 goto restart; 6240 } 6241 /* 6242 * Clear the old one. 6243 */ 6244 mp->mnt_rootvnode = NULL; 6245 } 6246 MNT_IUNLOCK(mp); 6247 if (vp != NULL) { 6248 vfs_op_barrier_wait(mp); 6249 vrele(vp); 6250 } 6251 } 6252 error = VFS_CACHEDROOT(mp, flags, vpp); 6253 if (error != 0) 6254 return (error); 6255 if (mp->mnt_vfs_ops == 0) { 6256 MNT_ILOCK(mp); 6257 if (mp->mnt_vfs_ops != 0) { 6258 MNT_IUNLOCK(mp); 6259 return (0); 6260 } 6261 if (mp->mnt_rootvnode == NULL) { 6262 vrefact(*vpp); 6263 mp->mnt_rootvnode = *vpp; 6264 } else { 6265 if (mp->mnt_rootvnode != *vpp) { 6266 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6267 panic("%s: mismatch between vnode returned " 6268 " by VFS_CACHEDROOT and the one cached " 6269 " (%p != %p)", 6270 __func__, *vpp, mp->mnt_rootvnode); 6271 } 6272 } 6273 } 6274 MNT_IUNLOCK(mp); 6275 } 6276 return (0); 6277 } 6278 6279 int 6280 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6281 { 6282 struct vnode *vp; 6283 int error; 6284 6285 if (!vfs_op_thread_enter(mp)) 6286 return (vfs_cache_root_fallback(mp, flags, vpp)); 6287 vp = atomic_load_ptr(&mp->mnt_rootvnode); 6288 if (vp == NULL || VN_IS_DOOMED(vp)) { 6289 vfs_op_thread_exit(mp); 6290 return (vfs_cache_root_fallback(mp, flags, vpp)); 6291 } 6292 vrefact(vp); 6293 vfs_op_thread_exit(mp); 6294 error = vn_lock(vp, flags); 6295 if (error != 0) { 6296 vrele(vp); 6297 return (vfs_cache_root_fallback(mp, flags, vpp)); 6298 } 6299 *vpp = vp; 6300 return (0); 6301 } 6302 6303 struct vnode * 6304 vfs_cache_root_clear(struct mount *mp) 6305 { 6306 struct vnode *vp; 6307 6308 /* 6309 * ops > 0 guarantees there is nobody who can see this vnode 6310 */ 6311 MPASS(mp->mnt_vfs_ops > 0); 6312 vp = mp->mnt_rootvnode; 6313 if (vp != NULL) 6314 vn_seqc_write_begin(vp); 6315 mp->mnt_rootvnode = NULL; 6316 return (vp); 6317 } 6318 6319 void 6320 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6321 { 6322 6323 MPASS(mp->mnt_vfs_ops > 0); 6324 vrefact(vp); 6325 mp->mnt_rootvnode = vp; 6326 } 6327 6328 /* 6329 * These are helper functions for filesystems to traverse all 6330 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6331 * 6332 * This interface replaces MNT_VNODE_FOREACH. 6333 */ 6334 6335 struct vnode * 6336 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6337 { 6338 struct vnode *vp; 6339 6340 if (should_yield()) 6341 kern_yield(PRI_USER); 6342 MNT_ILOCK(mp); 6343 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6344 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6345 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6346 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6347 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6348 continue; 6349 VI_LOCK(vp); 6350 if (VN_IS_DOOMED(vp)) { 6351 VI_UNLOCK(vp); 6352 continue; 6353 } 6354 break; 6355 } 6356 if (vp == NULL) { 6357 __mnt_vnode_markerfree_all(mvp, mp); 6358 /* MNT_IUNLOCK(mp); -- done in above function */ 6359 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6360 return (NULL); 6361 } 6362 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6363 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6364 MNT_IUNLOCK(mp); 6365 return (vp); 6366 } 6367 6368 struct vnode * 6369 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6370 { 6371 struct vnode *vp; 6372 6373 *mvp = vn_alloc_marker(mp); 6374 MNT_ILOCK(mp); 6375 MNT_REF(mp); 6376 6377 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6378 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6379 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6380 continue; 6381 VI_LOCK(vp); 6382 if (VN_IS_DOOMED(vp)) { 6383 VI_UNLOCK(vp); 6384 continue; 6385 } 6386 break; 6387 } 6388 if (vp == NULL) { 6389 MNT_REL(mp); 6390 MNT_IUNLOCK(mp); 6391 vn_free_marker(*mvp); 6392 *mvp = NULL; 6393 return (NULL); 6394 } 6395 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6396 MNT_IUNLOCK(mp); 6397 return (vp); 6398 } 6399 6400 void 6401 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6402 { 6403 6404 if (*mvp == NULL) { 6405 MNT_IUNLOCK(mp); 6406 return; 6407 } 6408 6409 mtx_assert(MNT_MTX(mp), MA_OWNED); 6410 6411 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6412 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6413 MNT_REL(mp); 6414 MNT_IUNLOCK(mp); 6415 vn_free_marker(*mvp); 6416 *mvp = NULL; 6417 } 6418 6419 /* 6420 * These are helper functions for filesystems to traverse their 6421 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6422 */ 6423 static void 6424 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6425 { 6426 6427 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6428 6429 MNT_ILOCK(mp); 6430 MNT_REL(mp); 6431 MNT_IUNLOCK(mp); 6432 vn_free_marker(*mvp); 6433 *mvp = NULL; 6434 } 6435 6436 /* 6437 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6438 * conventional lock order during mnt_vnode_next_lazy iteration. 6439 * 6440 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6441 * The list lock is dropped and reacquired. On success, both locks are held. 6442 * On failure, the mount vnode list lock is held but the vnode interlock is 6443 * not, and the procedure may have yielded. 6444 */ 6445 static bool 6446 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6447 struct vnode *vp) 6448 { 6449 6450 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6451 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6452 ("%s: bad marker", __func__)); 6453 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6454 ("%s: inappropriate vnode", __func__)); 6455 ASSERT_VI_UNLOCKED(vp, __func__); 6456 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6457 6458 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6459 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6460 6461 /* 6462 * Note we may be racing against vdrop which transitioned the hold 6463 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine, 6464 * if we are the only user after we get the interlock we will just 6465 * vdrop. 6466 */ 6467 vhold(vp); 6468 mtx_unlock(&mp->mnt_listmtx); 6469 VI_LOCK(vp); 6470 if (VN_IS_DOOMED(vp)) { 6471 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6472 goto out_lost; 6473 } 6474 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6475 /* 6476 * There is nothing to do if we are the last user. 6477 */ 6478 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6479 goto out_lost; 6480 mtx_lock(&mp->mnt_listmtx); 6481 return (true); 6482 out_lost: 6483 vdropl(vp); 6484 maybe_yield(); 6485 mtx_lock(&mp->mnt_listmtx); 6486 return (false); 6487 } 6488 6489 static struct vnode * 6490 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6491 void *cbarg) 6492 { 6493 struct vnode *vp; 6494 6495 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6496 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6497 restart: 6498 vp = TAILQ_NEXT(*mvp, v_lazylist); 6499 while (vp != NULL) { 6500 if (vp->v_type == VMARKER) { 6501 vp = TAILQ_NEXT(vp, v_lazylist); 6502 continue; 6503 } 6504 /* 6505 * See if we want to process the vnode. Note we may encounter a 6506 * long string of vnodes we don't care about and hog the list 6507 * as a result. Check for it and requeue the marker. 6508 */ 6509 VNPASS(!VN_IS_DOOMED(vp), vp); 6510 if (!cb(vp, cbarg)) { 6511 if (!should_yield()) { 6512 vp = TAILQ_NEXT(vp, v_lazylist); 6513 continue; 6514 } 6515 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 6516 v_lazylist); 6517 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 6518 v_lazylist); 6519 mtx_unlock(&mp->mnt_listmtx); 6520 kern_yield(PRI_USER); 6521 mtx_lock(&mp->mnt_listmtx); 6522 goto restart; 6523 } 6524 /* 6525 * Try-lock because this is the wrong lock order. 6526 */ 6527 if (!VI_TRYLOCK(vp) && 6528 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 6529 goto restart; 6530 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 6531 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 6532 ("alien vnode on the lazy list %p %p", vp, mp)); 6533 VNPASS(vp->v_mount == mp, vp); 6534 VNPASS(!VN_IS_DOOMED(vp), vp); 6535 break; 6536 } 6537 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6538 6539 /* Check if we are done */ 6540 if (vp == NULL) { 6541 mtx_unlock(&mp->mnt_listmtx); 6542 mnt_vnode_markerfree_lazy(mvp, mp); 6543 return (NULL); 6544 } 6545 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 6546 mtx_unlock(&mp->mnt_listmtx); 6547 ASSERT_VI_LOCKED(vp, "lazy iter"); 6548 return (vp); 6549 } 6550 6551 struct vnode * 6552 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6553 void *cbarg) 6554 { 6555 6556 if (should_yield()) 6557 kern_yield(PRI_USER); 6558 mtx_lock(&mp->mnt_listmtx); 6559 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6560 } 6561 6562 struct vnode * 6563 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6564 void *cbarg) 6565 { 6566 struct vnode *vp; 6567 6568 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 6569 return (NULL); 6570 6571 *mvp = vn_alloc_marker(mp); 6572 MNT_ILOCK(mp); 6573 MNT_REF(mp); 6574 MNT_IUNLOCK(mp); 6575 6576 mtx_lock(&mp->mnt_listmtx); 6577 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 6578 if (vp == NULL) { 6579 mtx_unlock(&mp->mnt_listmtx); 6580 mnt_vnode_markerfree_lazy(mvp, mp); 6581 return (NULL); 6582 } 6583 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 6584 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6585 } 6586 6587 void 6588 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6589 { 6590 6591 if (*mvp == NULL) 6592 return; 6593 6594 mtx_lock(&mp->mnt_listmtx); 6595 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6596 mtx_unlock(&mp->mnt_listmtx); 6597 mnt_vnode_markerfree_lazy(mvp, mp); 6598 } 6599 6600 int 6601 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 6602 { 6603 6604 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 6605 cnp->cn_flags &= ~NOEXECCHECK; 6606 return (0); 6607 } 6608 6609 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread)); 6610 } 6611 6612 /* 6613 * Do not use this variant unless you have means other than the hold count 6614 * to prevent the vnode from getting freed. 6615 */ 6616 void 6617 vn_seqc_write_begin_unheld_locked(struct vnode *vp) 6618 { 6619 6620 ASSERT_VI_LOCKED(vp, __func__); 6621 VNPASS(vp->v_seqc_users >= 0, vp); 6622 vp->v_seqc_users++; 6623 if (vp->v_seqc_users == 1) 6624 seqc_sleepable_write_begin(&vp->v_seqc); 6625 } 6626 6627 void 6628 vn_seqc_write_begin_locked(struct vnode *vp) 6629 { 6630 6631 ASSERT_VI_LOCKED(vp, __func__); 6632 VNPASS(vp->v_holdcnt > 0, vp); 6633 vn_seqc_write_begin_unheld_locked(vp); 6634 } 6635 6636 void 6637 vn_seqc_write_begin(struct vnode *vp) 6638 { 6639 6640 VI_LOCK(vp); 6641 vn_seqc_write_begin_locked(vp); 6642 VI_UNLOCK(vp); 6643 } 6644 6645 void 6646 vn_seqc_write_begin_unheld(struct vnode *vp) 6647 { 6648 6649 VI_LOCK(vp); 6650 vn_seqc_write_begin_unheld_locked(vp); 6651 VI_UNLOCK(vp); 6652 } 6653 6654 void 6655 vn_seqc_write_end_locked(struct vnode *vp) 6656 { 6657 6658 ASSERT_VI_LOCKED(vp, __func__); 6659 VNPASS(vp->v_seqc_users > 0, vp); 6660 vp->v_seqc_users--; 6661 if (vp->v_seqc_users == 0) 6662 seqc_sleepable_write_end(&vp->v_seqc); 6663 } 6664 6665 void 6666 vn_seqc_write_end(struct vnode *vp) 6667 { 6668 6669 VI_LOCK(vp); 6670 vn_seqc_write_end_locked(vp); 6671 VI_UNLOCK(vp); 6672 } 6673