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 __inline void 1297 vn_freevnodes_inc(void) 1298 { 1299 struct vdbatch *vd; 1300 1301 critical_enter(); 1302 vd = DPCPU_PTR(vd); 1303 vd->freevnodes++; 1304 critical_exit(); 1305 } 1306 1307 static __inline void 1308 vn_freevnodes_dec(void) 1309 { 1310 struct vdbatch *vd; 1311 1312 critical_enter(); 1313 vd = DPCPU_PTR(vd); 1314 vd->freevnodes--; 1315 critical_exit(); 1316 } 1317 1318 static u_long 1319 vnlru_read_freevnodes(void) 1320 { 1321 struct vdbatch *vd; 1322 long slop; 1323 int cpu; 1324 1325 mtx_assert(&vnode_list_mtx, MA_OWNED); 1326 if (freevnodes > freevnodes_old) 1327 slop = freevnodes - freevnodes_old; 1328 else 1329 slop = freevnodes_old - freevnodes; 1330 if (slop < VNLRU_FREEVNODES_SLOP) 1331 return (freevnodes >= 0 ? freevnodes : 0); 1332 freevnodes_old = freevnodes; 1333 CPU_FOREACH(cpu) { 1334 vd = DPCPU_ID_PTR((cpu), vd); 1335 freevnodes_old += vd->freevnodes; 1336 } 1337 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1338 } 1339 1340 static bool 1341 vnlru_under(u_long rnumvnodes, u_long limit) 1342 { 1343 u_long rfreevnodes, space; 1344 1345 if (__predict_false(rnumvnodes > desiredvnodes)) 1346 return (true); 1347 1348 space = desiredvnodes - rnumvnodes; 1349 if (space < limit) { 1350 rfreevnodes = vnlru_read_freevnodes(); 1351 if (rfreevnodes > wantfreevnodes) 1352 space += rfreevnodes - wantfreevnodes; 1353 } 1354 return (space < limit); 1355 } 1356 1357 static bool 1358 vnlru_under_unlocked(u_long rnumvnodes, u_long limit) 1359 { 1360 long rfreevnodes, space; 1361 1362 if (__predict_false(rnumvnodes > desiredvnodes)) 1363 return (true); 1364 1365 space = desiredvnodes - rnumvnodes; 1366 if (space < limit) { 1367 rfreevnodes = atomic_load_long(&freevnodes); 1368 if (rfreevnodes > wantfreevnodes) 1369 space += rfreevnodes - wantfreevnodes; 1370 } 1371 return (space < limit); 1372 } 1373 1374 static void 1375 vnlru_kick(void) 1376 { 1377 1378 mtx_assert(&vnode_list_mtx, MA_OWNED); 1379 if (vnlruproc_sig == 0) { 1380 vnlruproc_sig = 1; 1381 wakeup(vnlruproc); 1382 } 1383 } 1384 1385 static void 1386 vnlru_proc(void) 1387 { 1388 u_long rnumvnodes, rfreevnodes, target; 1389 unsigned long onumvnodes; 1390 int done, force, trigger, usevnodes; 1391 bool reclaim_nc_src, want_reread; 1392 1393 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1394 SHUTDOWN_PRI_FIRST); 1395 1396 force = 0; 1397 want_reread = false; 1398 for (;;) { 1399 kproc_suspend_check(vnlruproc); 1400 mtx_lock(&vnode_list_mtx); 1401 rnumvnodes = atomic_load_long(&numvnodes); 1402 1403 if (want_reread) { 1404 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1405 want_reread = false; 1406 } 1407 1408 /* 1409 * If numvnodes is too large (due to desiredvnodes being 1410 * adjusted using its sysctl, or emergency growth), first 1411 * try to reduce it by discarding from the free list. 1412 */ 1413 if (rnumvnodes > desiredvnodes) { 1414 vnlru_free_locked(rnumvnodes - desiredvnodes, NULL); 1415 rnumvnodes = atomic_load_long(&numvnodes); 1416 } 1417 /* 1418 * Sleep if the vnode cache is in a good state. This is 1419 * when it is not over-full and has space for about a 4% 1420 * or 9% expansion (by growing its size or inexcessively 1421 * reducing its free list). Otherwise, try to reclaim 1422 * space for a 10% expansion. 1423 */ 1424 if (vstir && force == 0) { 1425 force = 1; 1426 vstir = 0; 1427 } 1428 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1429 vnlruproc_sig = 0; 1430 wakeup(&vnlruproc_sig); 1431 msleep(vnlruproc, &vnode_list_mtx, 1432 PVFS|PDROP, "vlruwt", hz); 1433 continue; 1434 } 1435 rfreevnodes = vnlru_read_freevnodes(); 1436 1437 onumvnodes = rnumvnodes; 1438 /* 1439 * Calculate parameters for recycling. These are the same 1440 * throughout the loop to give some semblance of fairness. 1441 * The trigger point is to avoid recycling vnodes with lots 1442 * of resident pages. We aren't trying to free memory; we 1443 * are trying to recycle or at least free vnodes. 1444 */ 1445 if (rnumvnodes <= desiredvnodes) 1446 usevnodes = rnumvnodes - rfreevnodes; 1447 else 1448 usevnodes = rnumvnodes; 1449 if (usevnodes <= 0) 1450 usevnodes = 1; 1451 /* 1452 * The trigger value is is chosen to give a conservatively 1453 * large value to ensure that it alone doesn't prevent 1454 * making progress. The value can easily be so large that 1455 * it is effectively infinite in some congested and 1456 * misconfigured cases, and this is necessary. Normally 1457 * it is about 8 to 100 (pages), which is quite large. 1458 */ 1459 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1460 if (force < 2) 1461 trigger = vsmalltrigger; 1462 reclaim_nc_src = force >= 3; 1463 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1464 target = target / 10 + 1; 1465 done = vlrureclaim(reclaim_nc_src, trigger, target); 1466 mtx_unlock(&vnode_list_mtx); 1467 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1468 uma_reclaim(UMA_RECLAIM_DRAIN); 1469 if (done == 0) { 1470 if (force == 0 || force == 1) { 1471 force = 2; 1472 continue; 1473 } 1474 if (force == 2) { 1475 force = 3; 1476 continue; 1477 } 1478 want_reread = true; 1479 force = 0; 1480 vnlru_nowhere++; 1481 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1482 } else { 1483 want_reread = true; 1484 kern_yield(PRI_USER); 1485 } 1486 } 1487 } 1488 1489 static struct kproc_desc vnlru_kp = { 1490 "vnlru", 1491 vnlru_proc, 1492 &vnlruproc 1493 }; 1494 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1495 &vnlru_kp); 1496 1497 /* 1498 * Routines having to do with the management of the vnode table. 1499 */ 1500 1501 /* 1502 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1503 * before we actually vgone(). This function must be called with the vnode 1504 * held to prevent the vnode from being returned to the free list midway 1505 * through vgone(). 1506 */ 1507 static int 1508 vtryrecycle(struct vnode *vp) 1509 { 1510 struct mount *vnmp; 1511 1512 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1513 VNASSERT(vp->v_holdcnt, vp, 1514 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1515 /* 1516 * This vnode may found and locked via some other list, if so we 1517 * can't recycle it yet. 1518 */ 1519 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1520 CTR2(KTR_VFS, 1521 "%s: impossible to recycle, vp %p lock is already held", 1522 __func__, vp); 1523 return (EWOULDBLOCK); 1524 } 1525 /* 1526 * Don't recycle if its filesystem is being suspended. 1527 */ 1528 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1529 VOP_UNLOCK(vp); 1530 CTR2(KTR_VFS, 1531 "%s: impossible to recycle, cannot start the write for %p", 1532 __func__, vp); 1533 return (EBUSY); 1534 } 1535 /* 1536 * If we got this far, we need to acquire the interlock and see if 1537 * anyone picked up this vnode from another list. If not, we will 1538 * mark it with DOOMED via vgonel() so that anyone who does find it 1539 * will skip over it. 1540 */ 1541 VI_LOCK(vp); 1542 if (vp->v_usecount) { 1543 VOP_UNLOCK(vp); 1544 VI_UNLOCK(vp); 1545 vn_finished_write(vnmp); 1546 CTR2(KTR_VFS, 1547 "%s: impossible to recycle, %p is already referenced", 1548 __func__, vp); 1549 return (EBUSY); 1550 } 1551 if (!VN_IS_DOOMED(vp)) { 1552 counter_u64_add(recycles_free_count, 1); 1553 vgonel(vp); 1554 } 1555 VOP_UNLOCK(vp); 1556 VI_UNLOCK(vp); 1557 vn_finished_write(vnmp); 1558 return (0); 1559 } 1560 1561 /* 1562 * Allocate a new vnode. 1563 * 1564 * The operation never returns an error. Returning an error was disabled 1565 * in r145385 (dated 2005) with the following comment: 1566 * 1567 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1568 * 1569 * Given the age of this commit (almost 15 years at the time of writing this 1570 * comment) restoring the ability to fail requires a significant audit of 1571 * all codepaths. 1572 * 1573 * The routine can try to free a vnode or stall for up to 1 second waiting for 1574 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1575 */ 1576 static u_long vn_alloc_cyclecount; 1577 1578 static struct vnode * __noinline 1579 vn_alloc_hard(struct mount *mp) 1580 { 1581 u_long rnumvnodes, rfreevnodes; 1582 1583 mtx_lock(&vnode_list_mtx); 1584 rnumvnodes = atomic_load_long(&numvnodes); 1585 if (rnumvnodes + 1 < desiredvnodes) { 1586 vn_alloc_cyclecount = 0; 1587 goto alloc; 1588 } 1589 rfreevnodes = vnlru_read_freevnodes(); 1590 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1591 vn_alloc_cyclecount = 0; 1592 vstir = 1; 1593 } 1594 /* 1595 * Grow the vnode cache if it will not be above its target max 1596 * after growing. Otherwise, if the free list is nonempty, try 1597 * to reclaim 1 item from it before growing the cache (possibly 1598 * above its target max if the reclamation failed or is delayed). 1599 * Otherwise, wait for some space. In all cases, schedule 1600 * vnlru_proc() if we are getting short of space. The watermarks 1601 * should be chosen so that we never wait or even reclaim from 1602 * the free list to below its target minimum. 1603 */ 1604 if (vnlru_free_locked(1, NULL) > 0) 1605 goto alloc; 1606 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1607 /* 1608 * Wait for space for a new vnode. 1609 */ 1610 vnlru_kick(); 1611 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1612 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1613 vnlru_read_freevnodes() > 1) 1614 vnlru_free_locked(1, NULL); 1615 } 1616 alloc: 1617 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1618 if (vnlru_under(rnumvnodes, vlowat)) 1619 vnlru_kick(); 1620 mtx_unlock(&vnode_list_mtx); 1621 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 1622 } 1623 1624 static struct vnode * 1625 vn_alloc(struct mount *mp) 1626 { 1627 u_long rnumvnodes; 1628 1629 if (__predict_false(vn_alloc_cyclecount != 0)) 1630 return (vn_alloc_hard(mp)); 1631 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1632 if (__predict_false(vnlru_under_unlocked(rnumvnodes, vlowat))) { 1633 atomic_subtract_long(&numvnodes, 1); 1634 return (vn_alloc_hard(mp)); 1635 } 1636 1637 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 1638 } 1639 1640 static void 1641 vn_free(struct vnode *vp) 1642 { 1643 1644 atomic_subtract_long(&numvnodes, 1); 1645 uma_zfree_smr(vnode_zone, vp); 1646 } 1647 1648 /* 1649 * Return the next vnode from the free list. 1650 */ 1651 int 1652 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1653 struct vnode **vpp) 1654 { 1655 struct vnode *vp; 1656 struct thread *td; 1657 struct lock_object *lo; 1658 1659 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1660 1661 KASSERT(vops->registered, 1662 ("%s: not registered vector op %p\n", __func__, vops)); 1663 1664 td = curthread; 1665 if (td->td_vp_reserved != NULL) { 1666 vp = td->td_vp_reserved; 1667 td->td_vp_reserved = NULL; 1668 } else { 1669 vp = vn_alloc(mp); 1670 } 1671 counter_u64_add(vnodes_created, 1); 1672 /* 1673 * Locks are given the generic name "vnode" when created. 1674 * Follow the historic practice of using the filesystem 1675 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1676 * 1677 * Locks live in a witness group keyed on their name. Thus, 1678 * when a lock is renamed, it must also move from the witness 1679 * group of its old name to the witness group of its new name. 1680 * 1681 * The change only needs to be made when the vnode moves 1682 * from one filesystem type to another. We ensure that each 1683 * filesystem use a single static name pointer for its tag so 1684 * that we can compare pointers rather than doing a strcmp(). 1685 */ 1686 lo = &vp->v_vnlock->lock_object; 1687 #ifdef WITNESS 1688 if (lo->lo_name != tag) { 1689 #endif 1690 lo->lo_name = tag; 1691 #ifdef WITNESS 1692 WITNESS_DESTROY(lo); 1693 WITNESS_INIT(lo, tag); 1694 } 1695 #endif 1696 /* 1697 * By default, don't allow shared locks unless filesystems opt-in. 1698 */ 1699 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1700 /* 1701 * Finalize various vnode identity bits. 1702 */ 1703 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1704 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1705 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1706 vp->v_type = VNON; 1707 vp->v_op = vops; 1708 v_init_counters(vp); 1709 vp->v_bufobj.bo_ops = &buf_ops_bio; 1710 #ifdef DIAGNOSTIC 1711 if (mp == NULL && vops != &dead_vnodeops) 1712 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1713 #endif 1714 #ifdef MAC 1715 mac_vnode_init(vp); 1716 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1717 mac_vnode_associate_singlelabel(mp, vp); 1718 #endif 1719 if (mp != NULL) { 1720 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1721 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1722 vp->v_vflag |= VV_NOKNOTE; 1723 } 1724 1725 /* 1726 * For the filesystems which do not use vfs_hash_insert(), 1727 * still initialize v_hash to have vfs_hash_index() useful. 1728 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1729 * its own hashing. 1730 */ 1731 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1732 1733 *vpp = vp; 1734 return (0); 1735 } 1736 1737 void 1738 getnewvnode_reserve(void) 1739 { 1740 struct thread *td; 1741 1742 td = curthread; 1743 MPASS(td->td_vp_reserved == NULL); 1744 td->td_vp_reserved = vn_alloc(NULL); 1745 } 1746 1747 void 1748 getnewvnode_drop_reserve(void) 1749 { 1750 struct thread *td; 1751 1752 td = curthread; 1753 if (td->td_vp_reserved != NULL) { 1754 vn_free(td->td_vp_reserved); 1755 td->td_vp_reserved = NULL; 1756 } 1757 } 1758 1759 static void __noinline 1760 freevnode(struct vnode *vp) 1761 { 1762 struct bufobj *bo; 1763 1764 /* 1765 * The vnode has been marked for destruction, so free it. 1766 * 1767 * The vnode will be returned to the zone where it will 1768 * normally remain until it is needed for another vnode. We 1769 * need to cleanup (or verify that the cleanup has already 1770 * been done) any residual data left from its current use 1771 * so as not to contaminate the freshly allocated vnode. 1772 */ 1773 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1774 /* 1775 * Paired with vgone. 1776 */ 1777 vn_seqc_write_end_locked(vp); 1778 VNPASS(vp->v_seqc_users == 0, vp); 1779 1780 bo = &vp->v_bufobj; 1781 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1782 VNPASS(vp->v_holdcnt == VHOLD_NO_SMR, vp); 1783 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1784 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1785 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1786 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1787 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1788 ("clean blk trie not empty")); 1789 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1790 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1791 ("dirty blk trie not empty")); 1792 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1793 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1794 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1795 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1796 ("Dangling rangelock waiters")); 1797 VI_UNLOCK(vp); 1798 #ifdef MAC 1799 mac_vnode_destroy(vp); 1800 #endif 1801 if (vp->v_pollinfo != NULL) { 1802 destroy_vpollinfo(vp->v_pollinfo); 1803 vp->v_pollinfo = NULL; 1804 } 1805 #ifdef INVARIANTS 1806 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1807 vp->v_op = NULL; 1808 #endif 1809 vp->v_mountedhere = NULL; 1810 vp->v_unpcb = NULL; 1811 vp->v_rdev = NULL; 1812 vp->v_fifoinfo = NULL; 1813 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1814 vp->v_irflag = 0; 1815 vp->v_iflag = 0; 1816 vp->v_vflag = 0; 1817 bo->bo_flag = 0; 1818 vn_free(vp); 1819 } 1820 1821 /* 1822 * Delete from old mount point vnode list, if on one. 1823 */ 1824 static void 1825 delmntque(struct vnode *vp) 1826 { 1827 struct mount *mp; 1828 1829 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 1830 1831 mp = vp->v_mount; 1832 if (mp == NULL) 1833 return; 1834 MNT_ILOCK(mp); 1835 VI_LOCK(vp); 1836 vp->v_mount = NULL; 1837 VI_UNLOCK(vp); 1838 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1839 ("bad mount point vnode list size")); 1840 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1841 mp->mnt_nvnodelistsize--; 1842 MNT_REL(mp); 1843 MNT_IUNLOCK(mp); 1844 } 1845 1846 static void 1847 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1848 { 1849 1850 vp->v_data = NULL; 1851 vp->v_op = &dead_vnodeops; 1852 vgone(vp); 1853 vput(vp); 1854 } 1855 1856 /* 1857 * Insert into list of vnodes for the new mount point, if available. 1858 */ 1859 int 1860 insmntque1(struct vnode *vp, struct mount *mp, 1861 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1862 { 1863 1864 KASSERT(vp->v_mount == NULL, 1865 ("insmntque: vnode already on per mount vnode list")); 1866 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1867 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1868 1869 /* 1870 * We acquire the vnode interlock early to ensure that the 1871 * vnode cannot be recycled by another process releasing a 1872 * holdcnt on it before we get it on both the vnode list 1873 * and the active vnode list. The mount mutex protects only 1874 * manipulation of the vnode list and the vnode freelist 1875 * mutex protects only manipulation of the active vnode list. 1876 * Hence the need to hold the vnode interlock throughout. 1877 */ 1878 MNT_ILOCK(mp); 1879 VI_LOCK(vp); 1880 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1881 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1882 mp->mnt_nvnodelistsize == 0)) && 1883 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1884 VI_UNLOCK(vp); 1885 MNT_IUNLOCK(mp); 1886 if (dtr != NULL) 1887 dtr(vp, dtr_arg); 1888 return (EBUSY); 1889 } 1890 vp->v_mount = mp; 1891 MNT_REF(mp); 1892 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1893 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1894 ("neg mount point vnode list size")); 1895 mp->mnt_nvnodelistsize++; 1896 VI_UNLOCK(vp); 1897 MNT_IUNLOCK(mp); 1898 return (0); 1899 } 1900 1901 int 1902 insmntque(struct vnode *vp, struct mount *mp) 1903 { 1904 1905 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1906 } 1907 1908 /* 1909 * Flush out and invalidate all buffers associated with a bufobj 1910 * Called with the underlying object locked. 1911 */ 1912 int 1913 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1914 { 1915 int error; 1916 1917 BO_LOCK(bo); 1918 if (flags & V_SAVE) { 1919 error = bufobj_wwait(bo, slpflag, slptimeo); 1920 if (error) { 1921 BO_UNLOCK(bo); 1922 return (error); 1923 } 1924 if (bo->bo_dirty.bv_cnt > 0) { 1925 BO_UNLOCK(bo); 1926 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1927 return (error); 1928 /* 1929 * XXX We could save a lock/unlock if this was only 1930 * enabled under INVARIANTS 1931 */ 1932 BO_LOCK(bo); 1933 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1934 panic("vinvalbuf: dirty bufs"); 1935 } 1936 } 1937 /* 1938 * If you alter this loop please notice that interlock is dropped and 1939 * reacquired in flushbuflist. Special care is needed to ensure that 1940 * no race conditions occur from this. 1941 */ 1942 do { 1943 error = flushbuflist(&bo->bo_clean, 1944 flags, bo, slpflag, slptimeo); 1945 if (error == 0 && !(flags & V_CLEANONLY)) 1946 error = flushbuflist(&bo->bo_dirty, 1947 flags, bo, slpflag, slptimeo); 1948 if (error != 0 && error != EAGAIN) { 1949 BO_UNLOCK(bo); 1950 return (error); 1951 } 1952 } while (error != 0); 1953 1954 /* 1955 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1956 * have write I/O in-progress but if there is a VM object then the 1957 * VM object can also have read-I/O in-progress. 1958 */ 1959 do { 1960 bufobj_wwait(bo, 0, 0); 1961 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1962 BO_UNLOCK(bo); 1963 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1964 BO_LOCK(bo); 1965 } 1966 } while (bo->bo_numoutput > 0); 1967 BO_UNLOCK(bo); 1968 1969 /* 1970 * Destroy the copy in the VM cache, too. 1971 */ 1972 if (bo->bo_object != NULL && 1973 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1974 VM_OBJECT_WLOCK(bo->bo_object); 1975 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1976 OBJPR_CLEANONLY : 0); 1977 VM_OBJECT_WUNLOCK(bo->bo_object); 1978 } 1979 1980 #ifdef INVARIANTS 1981 BO_LOCK(bo); 1982 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1983 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1984 bo->bo_clean.bv_cnt > 0)) 1985 panic("vinvalbuf: flush failed"); 1986 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1987 bo->bo_dirty.bv_cnt > 0) 1988 panic("vinvalbuf: flush dirty failed"); 1989 BO_UNLOCK(bo); 1990 #endif 1991 return (0); 1992 } 1993 1994 /* 1995 * Flush out and invalidate all buffers associated with a vnode. 1996 * Called with the underlying object locked. 1997 */ 1998 int 1999 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 2000 { 2001 2002 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2003 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 2004 if (vp->v_object != NULL && vp->v_object->handle != vp) 2005 return (0); 2006 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 2007 } 2008 2009 /* 2010 * Flush out buffers on the specified list. 2011 * 2012 */ 2013 static int 2014 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 2015 int slptimeo) 2016 { 2017 struct buf *bp, *nbp; 2018 int retval, error; 2019 daddr_t lblkno; 2020 b_xflags_t xflags; 2021 2022 ASSERT_BO_WLOCKED(bo); 2023 2024 retval = 0; 2025 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2026 /* 2027 * If we are flushing both V_NORMAL and V_ALT buffers then 2028 * do not skip any buffers. If we are flushing only V_NORMAL 2029 * buffers then skip buffers marked as BX_ALTDATA. If we are 2030 * flushing only V_ALT buffers then skip buffers not marked 2031 * as BX_ALTDATA. 2032 */ 2033 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2034 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2035 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2036 continue; 2037 } 2038 if (nbp != NULL) { 2039 lblkno = nbp->b_lblkno; 2040 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2041 } 2042 retval = EAGAIN; 2043 error = BUF_TIMELOCK(bp, 2044 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2045 "flushbuf", slpflag, slptimeo); 2046 if (error) { 2047 BO_LOCK(bo); 2048 return (error != ENOLCK ? error : EAGAIN); 2049 } 2050 KASSERT(bp->b_bufobj == bo, 2051 ("bp %p wrong b_bufobj %p should be %p", 2052 bp, bp->b_bufobj, bo)); 2053 /* 2054 * XXX Since there are no node locks for NFS, I 2055 * believe there is a slight chance that a delayed 2056 * write will occur while sleeping just above, so 2057 * check for it. 2058 */ 2059 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2060 (flags & V_SAVE)) { 2061 bremfree(bp); 2062 bp->b_flags |= B_ASYNC; 2063 bwrite(bp); 2064 BO_LOCK(bo); 2065 return (EAGAIN); /* XXX: why not loop ? */ 2066 } 2067 bremfree(bp); 2068 bp->b_flags |= (B_INVAL | B_RELBUF); 2069 bp->b_flags &= ~B_ASYNC; 2070 brelse(bp); 2071 BO_LOCK(bo); 2072 if (nbp == NULL) 2073 break; 2074 nbp = gbincore(bo, lblkno); 2075 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2076 != xflags) 2077 break; /* nbp invalid */ 2078 } 2079 return (retval); 2080 } 2081 2082 int 2083 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2084 { 2085 struct buf *bp; 2086 int error; 2087 daddr_t lblkno; 2088 2089 ASSERT_BO_LOCKED(bo); 2090 2091 for (lblkno = startn;;) { 2092 again: 2093 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2094 if (bp == NULL || bp->b_lblkno >= endn || 2095 bp->b_lblkno < startn) 2096 break; 2097 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2098 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2099 if (error != 0) { 2100 BO_RLOCK(bo); 2101 if (error == ENOLCK) 2102 goto again; 2103 return (error); 2104 } 2105 KASSERT(bp->b_bufobj == bo, 2106 ("bp %p wrong b_bufobj %p should be %p", 2107 bp, bp->b_bufobj, bo)); 2108 lblkno = bp->b_lblkno + 1; 2109 if ((bp->b_flags & B_MANAGED) == 0) 2110 bremfree(bp); 2111 bp->b_flags |= B_RELBUF; 2112 /* 2113 * In the VMIO case, use the B_NOREUSE flag to hint that the 2114 * pages backing each buffer in the range are unlikely to be 2115 * reused. Dirty buffers will have the hint applied once 2116 * they've been written. 2117 */ 2118 if ((bp->b_flags & B_VMIO) != 0) 2119 bp->b_flags |= B_NOREUSE; 2120 brelse(bp); 2121 BO_RLOCK(bo); 2122 } 2123 return (0); 2124 } 2125 2126 /* 2127 * Truncate a file's buffer and pages to a specified length. This 2128 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2129 * sync activity. 2130 */ 2131 int 2132 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2133 { 2134 struct buf *bp, *nbp; 2135 struct bufobj *bo; 2136 daddr_t startlbn; 2137 2138 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2139 vp, blksize, (uintmax_t)length); 2140 2141 /* 2142 * Round up to the *next* lbn. 2143 */ 2144 startlbn = howmany(length, blksize); 2145 2146 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2147 2148 bo = &vp->v_bufobj; 2149 restart_unlocked: 2150 BO_LOCK(bo); 2151 2152 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2153 ; 2154 2155 if (length > 0) { 2156 restartsync: 2157 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2158 if (bp->b_lblkno > 0) 2159 continue; 2160 /* 2161 * Since we hold the vnode lock this should only 2162 * fail if we're racing with the buf daemon. 2163 */ 2164 if (BUF_LOCK(bp, 2165 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2166 BO_LOCKPTR(bo)) == ENOLCK) 2167 goto restart_unlocked; 2168 2169 VNASSERT((bp->b_flags & B_DELWRI), vp, 2170 ("buf(%p) on dirty queue without DELWRI", bp)); 2171 2172 bremfree(bp); 2173 bawrite(bp); 2174 BO_LOCK(bo); 2175 goto restartsync; 2176 } 2177 } 2178 2179 bufobj_wwait(bo, 0, 0); 2180 BO_UNLOCK(bo); 2181 vnode_pager_setsize(vp, length); 2182 2183 return (0); 2184 } 2185 2186 /* 2187 * Invalidate the cached pages of a file's buffer within the range of block 2188 * numbers [startlbn, endlbn). 2189 */ 2190 void 2191 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2192 int blksize) 2193 { 2194 struct bufobj *bo; 2195 off_t start, end; 2196 2197 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2198 2199 start = blksize * startlbn; 2200 end = blksize * endlbn; 2201 2202 bo = &vp->v_bufobj; 2203 BO_LOCK(bo); 2204 MPASS(blksize == bo->bo_bsize); 2205 2206 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2207 ; 2208 2209 BO_UNLOCK(bo); 2210 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2211 } 2212 2213 static int 2214 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2215 daddr_t startlbn, daddr_t endlbn) 2216 { 2217 struct buf *bp, *nbp; 2218 bool anyfreed; 2219 2220 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2221 ASSERT_BO_LOCKED(bo); 2222 2223 do { 2224 anyfreed = false; 2225 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2226 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2227 continue; 2228 if (BUF_LOCK(bp, 2229 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2230 BO_LOCKPTR(bo)) == ENOLCK) { 2231 BO_LOCK(bo); 2232 return (EAGAIN); 2233 } 2234 2235 bremfree(bp); 2236 bp->b_flags |= B_INVAL | B_RELBUF; 2237 bp->b_flags &= ~B_ASYNC; 2238 brelse(bp); 2239 anyfreed = true; 2240 2241 BO_LOCK(bo); 2242 if (nbp != NULL && 2243 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2244 nbp->b_vp != vp || 2245 (nbp->b_flags & B_DELWRI) != 0)) 2246 return (EAGAIN); 2247 } 2248 2249 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2250 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2251 continue; 2252 if (BUF_LOCK(bp, 2253 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2254 BO_LOCKPTR(bo)) == ENOLCK) { 2255 BO_LOCK(bo); 2256 return (EAGAIN); 2257 } 2258 bremfree(bp); 2259 bp->b_flags |= B_INVAL | B_RELBUF; 2260 bp->b_flags &= ~B_ASYNC; 2261 brelse(bp); 2262 anyfreed = true; 2263 2264 BO_LOCK(bo); 2265 if (nbp != NULL && 2266 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2267 (nbp->b_vp != vp) || 2268 (nbp->b_flags & B_DELWRI) == 0)) 2269 return (EAGAIN); 2270 } 2271 } while (anyfreed); 2272 return (0); 2273 } 2274 2275 static void 2276 buf_vlist_remove(struct buf *bp) 2277 { 2278 struct bufv *bv; 2279 b_xflags_t flags; 2280 2281 flags = bp->b_xflags; 2282 2283 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2284 ASSERT_BO_WLOCKED(bp->b_bufobj); 2285 KASSERT((flags & (BX_VNDIRTY | BX_VNCLEAN)) != 0 && 2286 (flags & (BX_VNDIRTY | BX_VNCLEAN)) != (BX_VNDIRTY | BX_VNCLEAN), 2287 ("%s: buffer %p has invalid queue state", __func__, bp)); 2288 2289 if ((flags & BX_VNDIRTY) != 0) 2290 bv = &bp->b_bufobj->bo_dirty; 2291 else 2292 bv = &bp->b_bufobj->bo_clean; 2293 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2294 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2295 bv->bv_cnt--; 2296 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2297 } 2298 2299 /* 2300 * Add the buffer to the sorted clean or dirty block list. 2301 * 2302 * NOTE: xflags is passed as a constant, optimizing this inline function! 2303 */ 2304 static void 2305 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2306 { 2307 struct bufv *bv; 2308 struct buf *n; 2309 int error; 2310 2311 ASSERT_BO_WLOCKED(bo); 2312 KASSERT((bo->bo_flag & BO_NOBUFS) == 0, 2313 ("buf_vlist_add: bo %p does not allow bufs", bo)); 2314 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2315 ("dead bo %p", bo)); 2316 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2317 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2318 bp->b_xflags |= xflags; 2319 if (xflags & BX_VNDIRTY) 2320 bv = &bo->bo_dirty; 2321 else 2322 bv = &bo->bo_clean; 2323 2324 /* 2325 * Keep the list ordered. Optimize empty list insertion. Assume 2326 * we tend to grow at the tail so lookup_le should usually be cheaper 2327 * than _ge. 2328 */ 2329 if (bv->bv_cnt == 0 || 2330 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2331 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2332 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2333 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2334 else 2335 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2336 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2337 if (error) 2338 panic("buf_vlist_add: Preallocated nodes insufficient."); 2339 bv->bv_cnt++; 2340 } 2341 2342 /* 2343 * Look up a buffer using the buffer tries. 2344 */ 2345 struct buf * 2346 gbincore(struct bufobj *bo, daddr_t lblkno) 2347 { 2348 struct buf *bp; 2349 2350 ASSERT_BO_LOCKED(bo); 2351 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2352 if (bp != NULL) 2353 return (bp); 2354 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno)); 2355 } 2356 2357 /* 2358 * Look up a buf using the buffer tries, without the bufobj lock. This relies 2359 * on SMR for safe lookup, and bufs being in a no-free zone to provide type 2360 * stability of the result. Like other lockless lookups, the found buf may 2361 * already be invalid by the time this function returns. 2362 */ 2363 struct buf * 2364 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno) 2365 { 2366 struct buf *bp; 2367 2368 ASSERT_BO_UNLOCKED(bo); 2369 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno); 2370 if (bp != NULL) 2371 return (bp); 2372 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno)); 2373 } 2374 2375 /* 2376 * Associate a buffer with a vnode. 2377 */ 2378 void 2379 bgetvp(struct vnode *vp, struct buf *bp) 2380 { 2381 struct bufobj *bo; 2382 2383 bo = &vp->v_bufobj; 2384 ASSERT_BO_WLOCKED(bo); 2385 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2386 2387 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2388 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2389 ("bgetvp: bp already attached! %p", bp)); 2390 2391 vhold(vp); 2392 bp->b_vp = vp; 2393 bp->b_bufobj = bo; 2394 /* 2395 * Insert onto list for new vnode. 2396 */ 2397 buf_vlist_add(bp, bo, BX_VNCLEAN); 2398 } 2399 2400 /* 2401 * Disassociate a buffer from a vnode. 2402 */ 2403 void 2404 brelvp(struct buf *bp) 2405 { 2406 struct bufobj *bo; 2407 struct vnode *vp; 2408 2409 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2410 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2411 2412 /* 2413 * Delete from old vnode list, if on one. 2414 */ 2415 vp = bp->b_vp; /* XXX */ 2416 bo = bp->b_bufobj; 2417 BO_LOCK(bo); 2418 buf_vlist_remove(bp); 2419 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2420 bo->bo_flag &= ~BO_ONWORKLST; 2421 mtx_lock(&sync_mtx); 2422 LIST_REMOVE(bo, bo_synclist); 2423 syncer_worklist_len--; 2424 mtx_unlock(&sync_mtx); 2425 } 2426 bp->b_vp = NULL; 2427 bp->b_bufobj = NULL; 2428 BO_UNLOCK(bo); 2429 vdrop(vp); 2430 } 2431 2432 /* 2433 * Add an item to the syncer work queue. 2434 */ 2435 static void 2436 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2437 { 2438 int slot; 2439 2440 ASSERT_BO_WLOCKED(bo); 2441 2442 mtx_lock(&sync_mtx); 2443 if (bo->bo_flag & BO_ONWORKLST) 2444 LIST_REMOVE(bo, bo_synclist); 2445 else { 2446 bo->bo_flag |= BO_ONWORKLST; 2447 syncer_worklist_len++; 2448 } 2449 2450 if (delay > syncer_maxdelay - 2) 2451 delay = syncer_maxdelay - 2; 2452 slot = (syncer_delayno + delay) & syncer_mask; 2453 2454 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2455 mtx_unlock(&sync_mtx); 2456 } 2457 2458 static int 2459 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2460 { 2461 int error, len; 2462 2463 mtx_lock(&sync_mtx); 2464 len = syncer_worklist_len - sync_vnode_count; 2465 mtx_unlock(&sync_mtx); 2466 error = SYSCTL_OUT(req, &len, sizeof(len)); 2467 return (error); 2468 } 2469 2470 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2471 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2472 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2473 2474 static struct proc *updateproc; 2475 static void sched_sync(void); 2476 static struct kproc_desc up_kp = { 2477 "syncer", 2478 sched_sync, 2479 &updateproc 2480 }; 2481 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2482 2483 static int 2484 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2485 { 2486 struct vnode *vp; 2487 struct mount *mp; 2488 2489 *bo = LIST_FIRST(slp); 2490 if (*bo == NULL) 2491 return (0); 2492 vp = bo2vnode(*bo); 2493 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2494 return (1); 2495 /* 2496 * We use vhold in case the vnode does not 2497 * successfully sync. vhold prevents the vnode from 2498 * going away when we unlock the sync_mtx so that 2499 * we can acquire the vnode interlock. 2500 */ 2501 vholdl(vp); 2502 mtx_unlock(&sync_mtx); 2503 VI_UNLOCK(vp); 2504 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2505 vdrop(vp); 2506 mtx_lock(&sync_mtx); 2507 return (*bo == LIST_FIRST(slp)); 2508 } 2509 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2510 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2511 VOP_UNLOCK(vp); 2512 vn_finished_write(mp); 2513 BO_LOCK(*bo); 2514 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2515 /* 2516 * Put us back on the worklist. The worklist 2517 * routine will remove us from our current 2518 * position and then add us back in at a later 2519 * position. 2520 */ 2521 vn_syncer_add_to_worklist(*bo, syncdelay); 2522 } 2523 BO_UNLOCK(*bo); 2524 vdrop(vp); 2525 mtx_lock(&sync_mtx); 2526 return (0); 2527 } 2528 2529 static int first_printf = 1; 2530 2531 /* 2532 * System filesystem synchronizer daemon. 2533 */ 2534 static void 2535 sched_sync(void) 2536 { 2537 struct synclist *next, *slp; 2538 struct bufobj *bo; 2539 long starttime; 2540 struct thread *td = curthread; 2541 int last_work_seen; 2542 int net_worklist_len; 2543 int syncer_final_iter; 2544 int error; 2545 2546 last_work_seen = 0; 2547 syncer_final_iter = 0; 2548 syncer_state = SYNCER_RUNNING; 2549 starttime = time_uptime; 2550 td->td_pflags |= TDP_NORUNNINGBUF; 2551 2552 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2553 SHUTDOWN_PRI_LAST); 2554 2555 mtx_lock(&sync_mtx); 2556 for (;;) { 2557 if (syncer_state == SYNCER_FINAL_DELAY && 2558 syncer_final_iter == 0) { 2559 mtx_unlock(&sync_mtx); 2560 kproc_suspend_check(td->td_proc); 2561 mtx_lock(&sync_mtx); 2562 } 2563 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2564 if (syncer_state != SYNCER_RUNNING && 2565 starttime != time_uptime) { 2566 if (first_printf) { 2567 printf("\nSyncing disks, vnodes remaining... "); 2568 first_printf = 0; 2569 } 2570 printf("%d ", net_worklist_len); 2571 } 2572 starttime = time_uptime; 2573 2574 /* 2575 * Push files whose dirty time has expired. Be careful 2576 * of interrupt race on slp queue. 2577 * 2578 * Skip over empty worklist slots when shutting down. 2579 */ 2580 do { 2581 slp = &syncer_workitem_pending[syncer_delayno]; 2582 syncer_delayno += 1; 2583 if (syncer_delayno == syncer_maxdelay) 2584 syncer_delayno = 0; 2585 next = &syncer_workitem_pending[syncer_delayno]; 2586 /* 2587 * If the worklist has wrapped since the 2588 * it was emptied of all but syncer vnodes, 2589 * switch to the FINAL_DELAY state and run 2590 * for one more second. 2591 */ 2592 if (syncer_state == SYNCER_SHUTTING_DOWN && 2593 net_worklist_len == 0 && 2594 last_work_seen == syncer_delayno) { 2595 syncer_state = SYNCER_FINAL_DELAY; 2596 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2597 } 2598 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2599 syncer_worklist_len > 0); 2600 2601 /* 2602 * Keep track of the last time there was anything 2603 * on the worklist other than syncer vnodes. 2604 * Return to the SHUTTING_DOWN state if any 2605 * new work appears. 2606 */ 2607 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2608 last_work_seen = syncer_delayno; 2609 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2610 syncer_state = SYNCER_SHUTTING_DOWN; 2611 while (!LIST_EMPTY(slp)) { 2612 error = sync_vnode(slp, &bo, td); 2613 if (error == 1) { 2614 LIST_REMOVE(bo, bo_synclist); 2615 LIST_INSERT_HEAD(next, bo, bo_synclist); 2616 continue; 2617 } 2618 2619 if (first_printf == 0) { 2620 /* 2621 * Drop the sync mutex, because some watchdog 2622 * drivers need to sleep while patting 2623 */ 2624 mtx_unlock(&sync_mtx); 2625 wdog_kern_pat(WD_LASTVAL); 2626 mtx_lock(&sync_mtx); 2627 } 2628 2629 } 2630 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2631 syncer_final_iter--; 2632 /* 2633 * The variable rushjob allows the kernel to speed up the 2634 * processing of the filesystem syncer process. A rushjob 2635 * value of N tells the filesystem syncer to process the next 2636 * N seconds worth of work on its queue ASAP. Currently rushjob 2637 * is used by the soft update code to speed up the filesystem 2638 * syncer process when the incore state is getting so far 2639 * ahead of the disk that the kernel memory pool is being 2640 * threatened with exhaustion. 2641 */ 2642 if (rushjob > 0) { 2643 rushjob -= 1; 2644 continue; 2645 } 2646 /* 2647 * Just sleep for a short period of time between 2648 * iterations when shutting down to allow some I/O 2649 * to happen. 2650 * 2651 * If it has taken us less than a second to process the 2652 * current work, then wait. Otherwise start right over 2653 * again. We can still lose time if any single round 2654 * takes more than two seconds, but it does not really 2655 * matter as we are just trying to generally pace the 2656 * filesystem activity. 2657 */ 2658 if (syncer_state != SYNCER_RUNNING || 2659 time_uptime == starttime) { 2660 thread_lock(td); 2661 sched_prio(td, PPAUSE); 2662 thread_unlock(td); 2663 } 2664 if (syncer_state != SYNCER_RUNNING) 2665 cv_timedwait(&sync_wakeup, &sync_mtx, 2666 hz / SYNCER_SHUTDOWN_SPEEDUP); 2667 else if (time_uptime == starttime) 2668 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2669 } 2670 } 2671 2672 /* 2673 * Request the syncer daemon to speed up its work. 2674 * We never push it to speed up more than half of its 2675 * normal turn time, otherwise it could take over the cpu. 2676 */ 2677 int 2678 speedup_syncer(void) 2679 { 2680 int ret = 0; 2681 2682 mtx_lock(&sync_mtx); 2683 if (rushjob < syncdelay / 2) { 2684 rushjob += 1; 2685 stat_rush_requests += 1; 2686 ret = 1; 2687 } 2688 mtx_unlock(&sync_mtx); 2689 cv_broadcast(&sync_wakeup); 2690 return (ret); 2691 } 2692 2693 /* 2694 * Tell the syncer to speed up its work and run though its work 2695 * list several times, then tell it to shut down. 2696 */ 2697 static void 2698 syncer_shutdown(void *arg, int howto) 2699 { 2700 2701 if (howto & RB_NOSYNC) 2702 return; 2703 mtx_lock(&sync_mtx); 2704 syncer_state = SYNCER_SHUTTING_DOWN; 2705 rushjob = 0; 2706 mtx_unlock(&sync_mtx); 2707 cv_broadcast(&sync_wakeup); 2708 kproc_shutdown(arg, howto); 2709 } 2710 2711 void 2712 syncer_suspend(void) 2713 { 2714 2715 syncer_shutdown(updateproc, 0); 2716 } 2717 2718 void 2719 syncer_resume(void) 2720 { 2721 2722 mtx_lock(&sync_mtx); 2723 first_printf = 1; 2724 syncer_state = SYNCER_RUNNING; 2725 mtx_unlock(&sync_mtx); 2726 cv_broadcast(&sync_wakeup); 2727 kproc_resume(updateproc); 2728 } 2729 2730 /* 2731 * Move the buffer between the clean and dirty lists of its vnode. 2732 */ 2733 void 2734 reassignbuf(struct buf *bp) 2735 { 2736 struct vnode *vp; 2737 struct bufobj *bo; 2738 int delay; 2739 #ifdef INVARIANTS 2740 struct bufv *bv; 2741 #endif 2742 2743 vp = bp->b_vp; 2744 bo = bp->b_bufobj; 2745 2746 KASSERT((bp->b_flags & B_PAGING) == 0, 2747 ("%s: cannot reassign paging buffer %p", __func__, bp)); 2748 2749 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2750 bp, bp->b_vp, bp->b_flags); 2751 2752 BO_LOCK(bo); 2753 buf_vlist_remove(bp); 2754 2755 /* 2756 * If dirty, put on list of dirty buffers; otherwise insert onto list 2757 * of clean buffers. 2758 */ 2759 if (bp->b_flags & B_DELWRI) { 2760 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2761 switch (vp->v_type) { 2762 case VDIR: 2763 delay = dirdelay; 2764 break; 2765 case VCHR: 2766 delay = metadelay; 2767 break; 2768 default: 2769 delay = filedelay; 2770 } 2771 vn_syncer_add_to_worklist(bo, delay); 2772 } 2773 buf_vlist_add(bp, bo, BX_VNDIRTY); 2774 } else { 2775 buf_vlist_add(bp, bo, BX_VNCLEAN); 2776 2777 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2778 mtx_lock(&sync_mtx); 2779 LIST_REMOVE(bo, bo_synclist); 2780 syncer_worklist_len--; 2781 mtx_unlock(&sync_mtx); 2782 bo->bo_flag &= ~BO_ONWORKLST; 2783 } 2784 } 2785 #ifdef INVARIANTS 2786 bv = &bo->bo_clean; 2787 bp = TAILQ_FIRST(&bv->bv_hd); 2788 KASSERT(bp == NULL || bp->b_bufobj == bo, 2789 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2790 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2791 KASSERT(bp == NULL || bp->b_bufobj == bo, 2792 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2793 bv = &bo->bo_dirty; 2794 bp = TAILQ_FIRST(&bv->bv_hd); 2795 KASSERT(bp == NULL || bp->b_bufobj == bo, 2796 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2797 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2798 KASSERT(bp == NULL || bp->b_bufobj == bo, 2799 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2800 #endif 2801 BO_UNLOCK(bo); 2802 } 2803 2804 static void 2805 v_init_counters(struct vnode *vp) 2806 { 2807 2808 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2809 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2810 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2811 2812 refcount_init(&vp->v_holdcnt, 1); 2813 refcount_init(&vp->v_usecount, 1); 2814 } 2815 2816 /* 2817 * Grab a particular vnode from the free list, increment its 2818 * reference count and lock it. VIRF_DOOMED is set if the vnode 2819 * is being destroyed. Only callers who specify LK_RETRY will 2820 * see doomed vnodes. If inactive processing was delayed in 2821 * vput try to do it here. 2822 * 2823 * usecount is manipulated using atomics without holding any locks. 2824 * 2825 * holdcnt can be manipulated using atomics without holding any locks, 2826 * except when transitioning 1<->0, in which case the interlock is held. 2827 * 2828 * Consumers which don't guarantee liveness of the vnode can use SMR to 2829 * try to get a reference. Note this operation can fail since the vnode 2830 * may be awaiting getting freed by the time they get to it. 2831 */ 2832 enum vgetstate 2833 vget_prep_smr(struct vnode *vp) 2834 { 2835 enum vgetstate vs; 2836 2837 VFS_SMR_ASSERT_ENTERED(); 2838 2839 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2840 vs = VGET_USECOUNT; 2841 } else { 2842 if (vhold_smr(vp)) 2843 vs = VGET_HOLDCNT; 2844 else 2845 vs = VGET_NONE; 2846 } 2847 return (vs); 2848 } 2849 2850 enum vgetstate 2851 vget_prep(struct vnode *vp) 2852 { 2853 enum vgetstate vs; 2854 2855 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2856 vs = VGET_USECOUNT; 2857 } else { 2858 vhold(vp); 2859 vs = VGET_HOLDCNT; 2860 } 2861 return (vs); 2862 } 2863 2864 void 2865 vget_abort(struct vnode *vp, enum vgetstate vs) 2866 { 2867 2868 switch (vs) { 2869 case VGET_USECOUNT: 2870 vrele(vp); 2871 break; 2872 case VGET_HOLDCNT: 2873 vdrop(vp); 2874 break; 2875 default: 2876 __assert_unreachable(); 2877 } 2878 } 2879 2880 int 2881 vget(struct vnode *vp, int flags) 2882 { 2883 enum vgetstate vs; 2884 2885 vs = vget_prep(vp); 2886 return (vget_finish(vp, flags, vs)); 2887 } 2888 2889 int 2890 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2891 { 2892 int error; 2893 2894 if ((flags & LK_INTERLOCK) != 0) 2895 ASSERT_VI_LOCKED(vp, __func__); 2896 else 2897 ASSERT_VI_UNLOCKED(vp, __func__); 2898 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 2899 VNPASS(vp->v_holdcnt > 0, vp); 2900 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2901 2902 error = vn_lock(vp, flags); 2903 if (__predict_false(error != 0)) { 2904 vget_abort(vp, vs); 2905 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2906 vp); 2907 return (error); 2908 } 2909 2910 vget_finish_ref(vp, vs); 2911 return (0); 2912 } 2913 2914 void 2915 vget_finish_ref(struct vnode *vp, enum vgetstate vs) 2916 { 2917 int old; 2918 2919 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 2920 VNPASS(vp->v_holdcnt > 0, vp); 2921 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2922 2923 if (vs == VGET_USECOUNT) 2924 return; 2925 2926 /* 2927 * We hold the vnode. If the usecount is 0 it will be utilized to keep 2928 * the vnode around. Otherwise someone else lended their hold count and 2929 * we have to drop ours. 2930 */ 2931 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2932 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 2933 if (old != 0) { 2934 #ifdef INVARIANTS 2935 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2936 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2937 #else 2938 refcount_release(&vp->v_holdcnt); 2939 #endif 2940 } 2941 } 2942 2943 void 2944 vref(struct vnode *vp) 2945 { 2946 enum vgetstate vs; 2947 2948 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2949 vs = vget_prep(vp); 2950 vget_finish_ref(vp, vs); 2951 } 2952 2953 void 2954 vrefact(struct vnode *vp) 2955 { 2956 2957 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2958 #ifdef INVARIANTS 2959 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 2960 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 2961 #else 2962 refcount_acquire(&vp->v_usecount); 2963 #endif 2964 } 2965 2966 void 2967 vlazy(struct vnode *vp) 2968 { 2969 struct mount *mp; 2970 2971 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 2972 2973 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 2974 return; 2975 /* 2976 * We may get here for inactive routines after the vnode got doomed. 2977 */ 2978 if (VN_IS_DOOMED(vp)) 2979 return; 2980 mp = vp->v_mount; 2981 mtx_lock(&mp->mnt_listmtx); 2982 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 2983 vp->v_mflag |= VMP_LAZYLIST; 2984 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 2985 mp->mnt_lazyvnodelistsize++; 2986 } 2987 mtx_unlock(&mp->mnt_listmtx); 2988 } 2989 2990 /* 2991 * This routine is only meant to be called from vgonel prior to dooming 2992 * the vnode. 2993 */ 2994 static void 2995 vunlazy_gone(struct vnode *vp) 2996 { 2997 struct mount *mp; 2998 2999 ASSERT_VOP_ELOCKED(vp, __func__); 3000 ASSERT_VI_LOCKED(vp, __func__); 3001 VNPASS(!VN_IS_DOOMED(vp), vp); 3002 3003 if (vp->v_mflag & VMP_LAZYLIST) { 3004 mp = vp->v_mount; 3005 mtx_lock(&mp->mnt_listmtx); 3006 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3007 vp->v_mflag &= ~VMP_LAZYLIST; 3008 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3009 mp->mnt_lazyvnodelistsize--; 3010 mtx_unlock(&mp->mnt_listmtx); 3011 } 3012 } 3013 3014 static void 3015 vdefer_inactive(struct vnode *vp) 3016 { 3017 3018 ASSERT_VI_LOCKED(vp, __func__); 3019 VNASSERT(vp->v_holdcnt > 0, vp, 3020 ("%s: vnode without hold count", __func__)); 3021 if (VN_IS_DOOMED(vp)) { 3022 vdropl(vp); 3023 return; 3024 } 3025 if (vp->v_iflag & VI_DEFINACT) { 3026 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3027 vdropl(vp); 3028 return; 3029 } 3030 if (vp->v_usecount > 0) { 3031 vp->v_iflag &= ~VI_OWEINACT; 3032 vdropl(vp); 3033 return; 3034 } 3035 vlazy(vp); 3036 vp->v_iflag |= VI_DEFINACT; 3037 VI_UNLOCK(vp); 3038 counter_u64_add(deferred_inact, 1); 3039 } 3040 3041 static void 3042 vdefer_inactive_unlocked(struct vnode *vp) 3043 { 3044 3045 VI_LOCK(vp); 3046 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3047 vdropl(vp); 3048 return; 3049 } 3050 vdefer_inactive(vp); 3051 } 3052 3053 enum vput_op { VRELE, VPUT, VUNREF }; 3054 3055 /* 3056 * Handle ->v_usecount transitioning to 0. 3057 * 3058 * By releasing the last usecount we take ownership of the hold count which 3059 * provides liveness of the vnode, meaning we have to vdrop. 3060 * 3061 * For all vnodes we may need to perform inactive processing. It requires an 3062 * exclusive lock on the vnode, while it is legal to call here with only a 3063 * shared lock (or no locks). If locking the vnode in an expected manner fails, 3064 * inactive processing gets deferred to the syncer. 3065 * 3066 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3067 * on the lock being held all the way until VOP_INACTIVE. This in particular 3068 * happens with UFS which adds half-constructed vnodes to the hash, where they 3069 * can be found by other code. 3070 */ 3071 static void 3072 vput_final(struct vnode *vp, enum vput_op func) 3073 { 3074 int error; 3075 bool want_unlock; 3076 3077 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3078 VNPASS(vp->v_holdcnt > 0, vp); 3079 3080 VI_LOCK(vp); 3081 3082 /* 3083 * By the time we got here someone else might have transitioned 3084 * the count back to > 0. 3085 */ 3086 if (vp->v_usecount > 0) 3087 goto out; 3088 3089 /* 3090 * If the vnode is doomed vgone already performed inactive processing 3091 * (if needed). 3092 */ 3093 if (VN_IS_DOOMED(vp)) 3094 goto out; 3095 3096 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0)) 3097 goto out; 3098 3099 if (vp->v_iflag & VI_DOINGINACT) 3100 goto out; 3101 3102 /* 3103 * Locking operations here will drop the interlock and possibly the 3104 * vnode lock, opening a window where the vnode can get doomed all the 3105 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to 3106 * perform inactive. 3107 */ 3108 vp->v_iflag |= VI_OWEINACT; 3109 want_unlock = false; 3110 error = 0; 3111 switch (func) { 3112 case VRELE: 3113 switch (VOP_ISLOCKED(vp)) { 3114 case LK_EXCLUSIVE: 3115 break; 3116 case LK_EXCLOTHER: 3117 case 0: 3118 want_unlock = true; 3119 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3120 VI_LOCK(vp); 3121 break; 3122 default: 3123 /* 3124 * The lock has at least one sharer, but we have no way 3125 * to conclude whether this is us. Play it safe and 3126 * defer processing. 3127 */ 3128 error = EAGAIN; 3129 break; 3130 } 3131 break; 3132 case VPUT: 3133 want_unlock = true; 3134 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3135 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3136 LK_NOWAIT); 3137 VI_LOCK(vp); 3138 } 3139 break; 3140 case VUNREF: 3141 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3142 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3143 VI_LOCK(vp); 3144 } 3145 break; 3146 } 3147 if (error == 0) { 3148 vinactive(vp); 3149 if (want_unlock) 3150 VOP_UNLOCK(vp); 3151 vdropl(vp); 3152 } else { 3153 vdefer_inactive(vp); 3154 } 3155 return; 3156 out: 3157 if (func == VPUT) 3158 VOP_UNLOCK(vp); 3159 vdropl(vp); 3160 } 3161 3162 /* 3163 * Decrement ->v_usecount for a vnode. 3164 * 3165 * Releasing the last use count requires additional processing, see vput_final 3166 * above for details. 3167 * 3168 * Comment above each variant denotes lock state on entry and exit. 3169 */ 3170 3171 /* 3172 * in: any 3173 * out: same as passed in 3174 */ 3175 void 3176 vrele(struct vnode *vp) 3177 { 3178 3179 ASSERT_VI_UNLOCKED(vp, __func__); 3180 if (!refcount_release(&vp->v_usecount)) 3181 return; 3182 vput_final(vp, VRELE); 3183 } 3184 3185 /* 3186 * in: locked 3187 * out: unlocked 3188 */ 3189 void 3190 vput(struct vnode *vp) 3191 { 3192 3193 ASSERT_VOP_LOCKED(vp, __func__); 3194 ASSERT_VI_UNLOCKED(vp, __func__); 3195 if (!refcount_release(&vp->v_usecount)) { 3196 VOP_UNLOCK(vp); 3197 return; 3198 } 3199 vput_final(vp, VPUT); 3200 } 3201 3202 /* 3203 * in: locked 3204 * out: locked 3205 */ 3206 void 3207 vunref(struct vnode *vp) 3208 { 3209 3210 ASSERT_VOP_LOCKED(vp, __func__); 3211 ASSERT_VI_UNLOCKED(vp, __func__); 3212 if (!refcount_release(&vp->v_usecount)) 3213 return; 3214 vput_final(vp, VUNREF); 3215 } 3216 3217 void 3218 vhold(struct vnode *vp) 3219 { 3220 int old; 3221 3222 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3223 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3224 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3225 ("%s: wrong hold count %d", __func__, old)); 3226 if (old == 0) 3227 vn_freevnodes_dec(); 3228 } 3229 3230 void 3231 vholdl(struct vnode *vp) 3232 { 3233 3234 ASSERT_VI_LOCKED(vp, __func__); 3235 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3236 vhold(vp); 3237 } 3238 3239 void 3240 vholdnz(struct vnode *vp) 3241 { 3242 3243 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3244 #ifdef INVARIANTS 3245 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3246 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3247 ("%s: wrong hold count %d", __func__, old)); 3248 #else 3249 atomic_add_int(&vp->v_holdcnt, 1); 3250 #endif 3251 } 3252 3253 /* 3254 * Grab a hold count unless the vnode is freed. 3255 * 3256 * Only use this routine if vfs smr is the only protection you have against 3257 * freeing the vnode. 3258 * 3259 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag 3260 * is not set. After the flag is set the vnode becomes immutable to anyone but 3261 * the thread which managed to set the flag. 3262 * 3263 * It may be tempting to replace the loop with: 3264 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3265 * if (count & VHOLD_NO_SMR) { 3266 * backpedal and error out; 3267 * } 3268 * 3269 * However, while this is more performant, it hinders debugging by eliminating 3270 * the previously mentioned invariant. 3271 */ 3272 bool 3273 vhold_smr(struct vnode *vp) 3274 { 3275 int count; 3276 3277 VFS_SMR_ASSERT_ENTERED(); 3278 3279 count = atomic_load_int(&vp->v_holdcnt); 3280 for (;;) { 3281 if (count & VHOLD_NO_SMR) { 3282 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3283 ("non-zero hold count with flags %d\n", count)); 3284 return (false); 3285 } 3286 3287 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3288 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) { 3289 if (count == 0) 3290 vn_freevnodes_dec(); 3291 return (true); 3292 } 3293 } 3294 } 3295 3296 static void __noinline 3297 vdbatch_process(struct vdbatch *vd) 3298 { 3299 struct vnode *vp; 3300 int i; 3301 3302 mtx_assert(&vd->lock, MA_OWNED); 3303 MPASS(curthread->td_pinned > 0); 3304 MPASS(vd->index == VDBATCH_SIZE); 3305 3306 mtx_lock(&vnode_list_mtx); 3307 critical_enter(); 3308 freevnodes += vd->freevnodes; 3309 for (i = 0; i < VDBATCH_SIZE; i++) { 3310 vp = vd->tab[i]; 3311 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3312 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3313 MPASS(vp->v_dbatchcpu != NOCPU); 3314 vp->v_dbatchcpu = NOCPU; 3315 } 3316 mtx_unlock(&vnode_list_mtx); 3317 vd->freevnodes = 0; 3318 bzero(vd->tab, sizeof(vd->tab)); 3319 vd->index = 0; 3320 critical_exit(); 3321 } 3322 3323 static void 3324 vdbatch_enqueue(struct vnode *vp) 3325 { 3326 struct vdbatch *vd; 3327 3328 ASSERT_VI_LOCKED(vp, __func__); 3329 VNASSERT(!VN_IS_DOOMED(vp), vp, 3330 ("%s: deferring requeue of a doomed vnode", __func__)); 3331 3332 if (vp->v_dbatchcpu != NOCPU) { 3333 VI_UNLOCK(vp); 3334 return; 3335 } 3336 3337 sched_pin(); 3338 vd = DPCPU_PTR(vd); 3339 mtx_lock(&vd->lock); 3340 MPASS(vd->index < VDBATCH_SIZE); 3341 MPASS(vd->tab[vd->index] == NULL); 3342 /* 3343 * A hack: we depend on being pinned so that we know what to put in 3344 * ->v_dbatchcpu. 3345 */ 3346 vp->v_dbatchcpu = curcpu; 3347 vd->tab[vd->index] = vp; 3348 vd->index++; 3349 VI_UNLOCK(vp); 3350 if (vd->index == VDBATCH_SIZE) 3351 vdbatch_process(vd); 3352 mtx_unlock(&vd->lock); 3353 sched_unpin(); 3354 } 3355 3356 /* 3357 * This routine must only be called for vnodes which are about to be 3358 * deallocated. Supporting dequeue for arbitrary vndoes would require 3359 * validating that the locked batch matches. 3360 */ 3361 static void 3362 vdbatch_dequeue(struct vnode *vp) 3363 { 3364 struct vdbatch *vd; 3365 int i; 3366 short cpu; 3367 3368 VNASSERT(vp->v_type == VBAD || vp->v_type == VNON, vp, 3369 ("%s: called for a used vnode\n", __func__)); 3370 3371 cpu = vp->v_dbatchcpu; 3372 if (cpu == NOCPU) 3373 return; 3374 3375 vd = DPCPU_ID_PTR(cpu, vd); 3376 mtx_lock(&vd->lock); 3377 for (i = 0; i < vd->index; i++) { 3378 if (vd->tab[i] != vp) 3379 continue; 3380 vp->v_dbatchcpu = NOCPU; 3381 vd->index--; 3382 vd->tab[i] = vd->tab[vd->index]; 3383 vd->tab[vd->index] = NULL; 3384 break; 3385 } 3386 mtx_unlock(&vd->lock); 3387 /* 3388 * Either we dequeued the vnode above or the target CPU beat us to it. 3389 */ 3390 MPASS(vp->v_dbatchcpu == NOCPU); 3391 } 3392 3393 /* 3394 * Drop the hold count of the vnode. If this is the last reference to 3395 * the vnode we place it on the free list unless it has been vgone'd 3396 * (marked VIRF_DOOMED) in which case we will free it. 3397 * 3398 * Because the vnode vm object keeps a hold reference on the vnode if 3399 * there is at least one resident non-cached page, the vnode cannot 3400 * leave the active list without the page cleanup done. 3401 */ 3402 static void 3403 vdrop_deactivate(struct vnode *vp) 3404 { 3405 struct mount *mp; 3406 3407 ASSERT_VI_LOCKED(vp, __func__); 3408 /* 3409 * Mark a vnode as free: remove it from its active list 3410 * and put it up for recycling on the freelist. 3411 */ 3412 VNASSERT(!VN_IS_DOOMED(vp), vp, 3413 ("vdrop: returning doomed vnode")); 3414 VNASSERT(vp->v_op != NULL, vp, 3415 ("vdrop: vnode already reclaimed.")); 3416 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 3417 ("vnode with VI_OWEINACT set")); 3418 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, 3419 ("vnode with VI_DEFINACT set")); 3420 if (vp->v_mflag & VMP_LAZYLIST) { 3421 mp = vp->v_mount; 3422 mtx_lock(&mp->mnt_listmtx); 3423 VNASSERT(vp->v_mflag & VMP_LAZYLIST, vp, ("lost VMP_LAZYLIST")); 3424 /* 3425 * Don't remove the vnode from the lazy list if another thread 3426 * has increased the hold count. It may have re-enqueued the 3427 * vnode to the lazy list and is now responsible for its 3428 * removal. 3429 */ 3430 if (vp->v_holdcnt == 0) { 3431 vp->v_mflag &= ~VMP_LAZYLIST; 3432 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3433 mp->mnt_lazyvnodelistsize--; 3434 } 3435 mtx_unlock(&mp->mnt_listmtx); 3436 } 3437 vdbatch_enqueue(vp); 3438 } 3439 3440 static void __noinline 3441 vdropl_final(struct vnode *vp) 3442 { 3443 3444 ASSERT_VI_LOCKED(vp, __func__); 3445 VNPASS(VN_IS_DOOMED(vp), vp); 3446 /* 3447 * Set the VHOLD_NO_SMR flag. 3448 * 3449 * We may be racing against vhold_smr. If they win we can just pretend 3450 * we never got this far, they will vdrop later. 3451 */ 3452 if (__predict_false(!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR))) { 3453 vn_freevnodes_inc(); 3454 VI_UNLOCK(vp); 3455 /* 3456 * We lost the aforementioned race. Any subsequent access is 3457 * invalid as they might have managed to vdropl on their own. 3458 */ 3459 return; 3460 } 3461 /* 3462 * Don't bump freevnodes as this one is going away. 3463 */ 3464 freevnode(vp); 3465 } 3466 3467 void 3468 vdrop(struct vnode *vp) 3469 { 3470 3471 ASSERT_VI_UNLOCKED(vp, __func__); 3472 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3473 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3474 return; 3475 VI_LOCK(vp); 3476 vdropl(vp); 3477 } 3478 3479 void 3480 vdropl(struct vnode *vp) 3481 { 3482 3483 ASSERT_VI_LOCKED(vp, __func__); 3484 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3485 if (!refcount_release(&vp->v_holdcnt)) { 3486 VI_UNLOCK(vp); 3487 return; 3488 } 3489 if (!VN_IS_DOOMED(vp)) { 3490 vn_freevnodes_inc(); 3491 vdrop_deactivate(vp); 3492 /* 3493 * Also unlocks the interlock. We can't assert on it as we 3494 * released our hold and by now the vnode might have been 3495 * freed. 3496 */ 3497 return; 3498 } 3499 vdropl_final(vp); 3500 } 3501 3502 /* 3503 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3504 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3505 */ 3506 static void 3507 vinactivef(struct vnode *vp) 3508 { 3509 struct vm_object *obj; 3510 3511 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3512 ASSERT_VI_LOCKED(vp, "vinactive"); 3513 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3514 ("vinactive: recursed on VI_DOINGINACT")); 3515 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3516 vp->v_iflag |= VI_DOINGINACT; 3517 vp->v_iflag &= ~VI_OWEINACT; 3518 VI_UNLOCK(vp); 3519 /* 3520 * Before moving off the active list, we must be sure that any 3521 * modified pages are converted into the vnode's dirty 3522 * buffers, since these will no longer be checked once the 3523 * vnode is on the inactive list. 3524 * 3525 * The write-out of the dirty pages is asynchronous. At the 3526 * point that VOP_INACTIVE() is called, there could still be 3527 * pending I/O and dirty pages in the object. 3528 */ 3529 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3530 vm_object_mightbedirty(obj)) { 3531 VM_OBJECT_WLOCK(obj); 3532 vm_object_page_clean(obj, 0, 0, 0); 3533 VM_OBJECT_WUNLOCK(obj); 3534 } 3535 VOP_INACTIVE(vp, curthread); 3536 VI_LOCK(vp); 3537 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3538 ("vinactive: lost VI_DOINGINACT")); 3539 vp->v_iflag &= ~VI_DOINGINACT; 3540 } 3541 3542 void 3543 vinactive(struct vnode *vp) 3544 { 3545 3546 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3547 ASSERT_VI_LOCKED(vp, "vinactive"); 3548 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3549 3550 if ((vp->v_iflag & VI_OWEINACT) == 0) 3551 return; 3552 if (vp->v_iflag & VI_DOINGINACT) 3553 return; 3554 if (vp->v_usecount > 0) { 3555 vp->v_iflag &= ~VI_OWEINACT; 3556 return; 3557 } 3558 vinactivef(vp); 3559 } 3560 3561 /* 3562 * Remove any vnodes in the vnode table belonging to mount point mp. 3563 * 3564 * If FORCECLOSE is not specified, there should not be any active ones, 3565 * return error if any are found (nb: this is a user error, not a 3566 * system error). If FORCECLOSE is specified, detach any active vnodes 3567 * that are found. 3568 * 3569 * If WRITECLOSE is set, only flush out regular file vnodes open for 3570 * writing. 3571 * 3572 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3573 * 3574 * `rootrefs' specifies the base reference count for the root vnode 3575 * of this filesystem. The root vnode is considered busy if its 3576 * v_usecount exceeds this value. On a successful return, vflush(, td) 3577 * will call vrele() on the root vnode exactly rootrefs times. 3578 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3579 * be zero. 3580 */ 3581 #ifdef DIAGNOSTIC 3582 static int busyprt = 0; /* print out busy vnodes */ 3583 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3584 #endif 3585 3586 int 3587 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3588 { 3589 struct vnode *vp, *mvp, *rootvp = NULL; 3590 struct vattr vattr; 3591 int busy = 0, error; 3592 3593 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3594 rootrefs, flags); 3595 if (rootrefs > 0) { 3596 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3597 ("vflush: bad args")); 3598 /* 3599 * Get the filesystem root vnode. We can vput() it 3600 * immediately, since with rootrefs > 0, it won't go away. 3601 */ 3602 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3603 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3604 __func__, error); 3605 return (error); 3606 } 3607 vput(rootvp); 3608 } 3609 loop: 3610 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3611 vholdl(vp); 3612 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3613 if (error) { 3614 vdrop(vp); 3615 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3616 goto loop; 3617 } 3618 /* 3619 * Skip over a vnodes marked VV_SYSTEM. 3620 */ 3621 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3622 VOP_UNLOCK(vp); 3623 vdrop(vp); 3624 continue; 3625 } 3626 /* 3627 * If WRITECLOSE is set, flush out unlinked but still open 3628 * files (even if open only for reading) and regular file 3629 * vnodes open for writing. 3630 */ 3631 if (flags & WRITECLOSE) { 3632 if (vp->v_object != NULL) { 3633 VM_OBJECT_WLOCK(vp->v_object); 3634 vm_object_page_clean(vp->v_object, 0, 0, 0); 3635 VM_OBJECT_WUNLOCK(vp->v_object); 3636 } 3637 error = VOP_FSYNC(vp, MNT_WAIT, td); 3638 if (error != 0) { 3639 VOP_UNLOCK(vp); 3640 vdrop(vp); 3641 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3642 return (error); 3643 } 3644 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3645 VI_LOCK(vp); 3646 3647 if ((vp->v_type == VNON || 3648 (error == 0 && vattr.va_nlink > 0)) && 3649 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3650 VOP_UNLOCK(vp); 3651 vdropl(vp); 3652 continue; 3653 } 3654 } else 3655 VI_LOCK(vp); 3656 /* 3657 * With v_usecount == 0, all we need to do is clear out the 3658 * vnode data structures and we are done. 3659 * 3660 * If FORCECLOSE is set, forcibly close the vnode. 3661 */ 3662 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3663 vgonel(vp); 3664 } else { 3665 busy++; 3666 #ifdef DIAGNOSTIC 3667 if (busyprt) 3668 vn_printf(vp, "vflush: busy vnode "); 3669 #endif 3670 } 3671 VOP_UNLOCK(vp); 3672 vdropl(vp); 3673 } 3674 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3675 /* 3676 * If just the root vnode is busy, and if its refcount 3677 * is equal to `rootrefs', then go ahead and kill it. 3678 */ 3679 VI_LOCK(rootvp); 3680 KASSERT(busy > 0, ("vflush: not busy")); 3681 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3682 ("vflush: usecount %d < rootrefs %d", 3683 rootvp->v_usecount, rootrefs)); 3684 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3685 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3686 vgone(rootvp); 3687 VOP_UNLOCK(rootvp); 3688 busy = 0; 3689 } else 3690 VI_UNLOCK(rootvp); 3691 } 3692 if (busy) { 3693 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3694 busy); 3695 return (EBUSY); 3696 } 3697 for (; rootrefs > 0; rootrefs--) 3698 vrele(rootvp); 3699 return (0); 3700 } 3701 3702 /* 3703 * Recycle an unused vnode to the front of the free list. 3704 */ 3705 int 3706 vrecycle(struct vnode *vp) 3707 { 3708 int recycled; 3709 3710 VI_LOCK(vp); 3711 recycled = vrecyclel(vp); 3712 VI_UNLOCK(vp); 3713 return (recycled); 3714 } 3715 3716 /* 3717 * vrecycle, with the vp interlock held. 3718 */ 3719 int 3720 vrecyclel(struct vnode *vp) 3721 { 3722 int recycled; 3723 3724 ASSERT_VOP_ELOCKED(vp, __func__); 3725 ASSERT_VI_LOCKED(vp, __func__); 3726 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3727 recycled = 0; 3728 if (vp->v_usecount == 0) { 3729 recycled = 1; 3730 vgonel(vp); 3731 } 3732 return (recycled); 3733 } 3734 3735 /* 3736 * Eliminate all activity associated with a vnode 3737 * in preparation for reuse. 3738 */ 3739 void 3740 vgone(struct vnode *vp) 3741 { 3742 VI_LOCK(vp); 3743 vgonel(vp); 3744 VI_UNLOCK(vp); 3745 } 3746 3747 static void 3748 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3749 struct vnode *lowervp __unused) 3750 { 3751 } 3752 3753 /* 3754 * Notify upper mounts about reclaimed or unlinked vnode. 3755 */ 3756 void 3757 vfs_notify_upper(struct vnode *vp, int event) 3758 { 3759 static struct vfsops vgonel_vfsops = { 3760 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3761 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3762 }; 3763 struct mount *mp, *ump, *mmp; 3764 3765 mp = vp->v_mount; 3766 if (mp == NULL) 3767 return; 3768 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3769 return; 3770 3771 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3772 mmp->mnt_op = &vgonel_vfsops; 3773 mmp->mnt_kern_flag |= MNTK_MARKER; 3774 MNT_ILOCK(mp); 3775 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3776 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3777 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3778 ump = TAILQ_NEXT(ump, mnt_upper_link); 3779 continue; 3780 } 3781 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3782 MNT_IUNLOCK(mp); 3783 switch (event) { 3784 case VFS_NOTIFY_UPPER_RECLAIM: 3785 VFS_RECLAIM_LOWERVP(ump, vp); 3786 break; 3787 case VFS_NOTIFY_UPPER_UNLINK: 3788 VFS_UNLINK_LOWERVP(ump, vp); 3789 break; 3790 default: 3791 KASSERT(0, ("invalid event %d", event)); 3792 break; 3793 } 3794 MNT_ILOCK(mp); 3795 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3796 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3797 } 3798 free(mmp, M_TEMP); 3799 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3800 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3801 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3802 wakeup(&mp->mnt_uppers); 3803 } 3804 MNT_IUNLOCK(mp); 3805 } 3806 3807 /* 3808 * vgone, with the vp interlock held. 3809 */ 3810 static void 3811 vgonel(struct vnode *vp) 3812 { 3813 struct thread *td; 3814 struct mount *mp; 3815 vm_object_t object; 3816 bool active, oweinact; 3817 3818 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3819 ASSERT_VI_LOCKED(vp, "vgonel"); 3820 VNASSERT(vp->v_holdcnt, vp, 3821 ("vgonel: vp %p has no reference.", vp)); 3822 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3823 td = curthread; 3824 3825 /* 3826 * Don't vgonel if we're already doomed. 3827 */ 3828 if (vp->v_irflag & VIRF_DOOMED) 3829 return; 3830 /* 3831 * Paired with freevnode. 3832 */ 3833 vn_seqc_write_begin_locked(vp); 3834 vunlazy_gone(vp); 3835 vp->v_irflag |= VIRF_DOOMED; 3836 3837 /* 3838 * Check to see if the vnode is in use. If so, we have to call 3839 * VOP_CLOSE() and VOP_INACTIVE(). 3840 */ 3841 active = vp->v_usecount > 0; 3842 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 3843 /* 3844 * If we need to do inactive VI_OWEINACT will be set. 3845 */ 3846 if (vp->v_iflag & VI_DEFINACT) { 3847 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3848 vp->v_iflag &= ~VI_DEFINACT; 3849 vdropl(vp); 3850 } else { 3851 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 3852 VI_UNLOCK(vp); 3853 } 3854 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3855 3856 /* 3857 * If purging an active vnode, it must be closed and 3858 * deactivated before being reclaimed. 3859 */ 3860 if (active) 3861 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3862 if (oweinact || active) { 3863 VI_LOCK(vp); 3864 vinactivef(vp); 3865 VI_UNLOCK(vp); 3866 } 3867 if (vp->v_type == VSOCK) 3868 vfs_unp_reclaim(vp); 3869 3870 /* 3871 * Clean out any buffers associated with the vnode. 3872 * If the flush fails, just toss the buffers. 3873 */ 3874 mp = NULL; 3875 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3876 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3877 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3878 while (vinvalbuf(vp, 0, 0, 0) != 0) 3879 ; 3880 } 3881 3882 BO_LOCK(&vp->v_bufobj); 3883 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3884 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3885 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3886 vp->v_bufobj.bo_clean.bv_cnt == 0, 3887 ("vp %p bufobj not invalidated", vp)); 3888 3889 /* 3890 * For VMIO bufobj, BO_DEAD is set later, or in 3891 * vm_object_terminate() after the object's page queue is 3892 * flushed. 3893 */ 3894 object = vp->v_bufobj.bo_object; 3895 if (object == NULL) 3896 vp->v_bufobj.bo_flag |= BO_DEAD; 3897 BO_UNLOCK(&vp->v_bufobj); 3898 3899 /* 3900 * Handle the VM part. Tmpfs handles v_object on its own (the 3901 * OBJT_VNODE check). Nullfs or other bypassing filesystems 3902 * should not touch the object borrowed from the lower vnode 3903 * (the handle check). 3904 */ 3905 if (object != NULL && object->type == OBJT_VNODE && 3906 object->handle == vp) 3907 vnode_destroy_vobject(vp); 3908 3909 /* 3910 * Reclaim the vnode. 3911 */ 3912 if (VOP_RECLAIM(vp)) 3913 panic("vgone: cannot reclaim"); 3914 if (mp != NULL) 3915 vn_finished_secondary_write(mp); 3916 VNASSERT(vp->v_object == NULL, vp, 3917 ("vop_reclaim left v_object vp=%p", vp)); 3918 /* 3919 * Clear the advisory locks and wake up waiting threads. 3920 */ 3921 (void)VOP_ADVLOCKPURGE(vp); 3922 vp->v_lockf = NULL; 3923 /* 3924 * Delete from old mount point vnode list. 3925 */ 3926 delmntque(vp); 3927 cache_purge_vgone(vp); 3928 /* 3929 * Done with purge, reset to the standard lock and invalidate 3930 * the vnode. 3931 */ 3932 VI_LOCK(vp); 3933 vp->v_vnlock = &vp->v_lock; 3934 vp->v_op = &dead_vnodeops; 3935 vp->v_type = VBAD; 3936 } 3937 3938 /* 3939 * Print out a description of a vnode. 3940 */ 3941 static const char * const typename[] = 3942 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3943 "VMARKER"}; 3944 3945 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0, 3946 "new hold count flag not added to vn_printf"); 3947 3948 void 3949 vn_printf(struct vnode *vp, const char *fmt, ...) 3950 { 3951 va_list ap; 3952 char buf[256], buf2[16]; 3953 u_long flags; 3954 u_int holdcnt; 3955 3956 va_start(ap, fmt); 3957 vprintf(fmt, ap); 3958 va_end(ap); 3959 printf("%p: ", (void *)vp); 3960 printf("type %s\n", typename[vp->v_type]); 3961 holdcnt = atomic_load_int(&vp->v_holdcnt); 3962 printf(" usecount %d, writecount %d, refcount %d seqc users %d", 3963 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS, 3964 vp->v_seqc_users); 3965 switch (vp->v_type) { 3966 case VDIR: 3967 printf(" mountedhere %p\n", vp->v_mountedhere); 3968 break; 3969 case VCHR: 3970 printf(" rdev %p\n", vp->v_rdev); 3971 break; 3972 case VSOCK: 3973 printf(" socket %p\n", vp->v_unpcb); 3974 break; 3975 case VFIFO: 3976 printf(" fifoinfo %p\n", vp->v_fifoinfo); 3977 break; 3978 default: 3979 printf("\n"); 3980 break; 3981 } 3982 buf[0] = '\0'; 3983 buf[1] = '\0'; 3984 if (holdcnt & VHOLD_NO_SMR) 3985 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf)); 3986 printf(" hold count flags (%s)\n", buf + 1); 3987 3988 buf[0] = '\0'; 3989 buf[1] = '\0'; 3990 if (vp->v_irflag & VIRF_DOOMED) 3991 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 3992 if (vp->v_irflag & VIRF_PGREAD) 3993 strlcat(buf, "|VIRF_PGREAD", sizeof(buf)); 3994 flags = vp->v_irflag & ~(VIRF_DOOMED | VIRF_PGREAD); 3995 if (flags != 0) { 3996 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 3997 strlcat(buf, buf2, sizeof(buf)); 3998 } 3999 if (vp->v_vflag & VV_ROOT) 4000 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4001 if (vp->v_vflag & VV_ISTTY) 4002 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4003 if (vp->v_vflag & VV_NOSYNC) 4004 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4005 if (vp->v_vflag & VV_ETERNALDEV) 4006 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4007 if (vp->v_vflag & VV_CACHEDLABEL) 4008 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4009 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4010 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4011 if (vp->v_vflag & VV_COPYONWRITE) 4012 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4013 if (vp->v_vflag & VV_SYSTEM) 4014 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4015 if (vp->v_vflag & VV_PROCDEP) 4016 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4017 if (vp->v_vflag & VV_NOKNOTE) 4018 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 4019 if (vp->v_vflag & VV_DELETED) 4020 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4021 if (vp->v_vflag & VV_MD) 4022 strlcat(buf, "|VV_MD", sizeof(buf)); 4023 if (vp->v_vflag & VV_FORCEINSMQ) 4024 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4025 if (vp->v_vflag & VV_READLINK) 4026 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4027 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4028 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 4029 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 4030 if (flags != 0) { 4031 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4032 strlcat(buf, buf2, sizeof(buf)); 4033 } 4034 if (vp->v_iflag & VI_TEXT_REF) 4035 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 4036 if (vp->v_iflag & VI_MOUNT) 4037 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4038 if (vp->v_iflag & VI_DOINGINACT) 4039 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4040 if (vp->v_iflag & VI_OWEINACT) 4041 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4042 if (vp->v_iflag & VI_DEFINACT) 4043 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4044 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | 4045 VI_OWEINACT | VI_DEFINACT); 4046 if (flags != 0) { 4047 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4048 strlcat(buf, buf2, sizeof(buf)); 4049 } 4050 if (vp->v_mflag & VMP_LAZYLIST) 4051 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4052 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4053 if (flags != 0) { 4054 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4055 strlcat(buf, buf2, sizeof(buf)); 4056 } 4057 printf(" flags (%s)\n", buf + 1); 4058 if (mtx_owned(VI_MTX(vp))) 4059 printf(" VI_LOCKed"); 4060 if (vp->v_object != NULL) 4061 printf(" v_object %p ref %d pages %d " 4062 "cleanbuf %d dirtybuf %d\n", 4063 vp->v_object, vp->v_object->ref_count, 4064 vp->v_object->resident_page_count, 4065 vp->v_bufobj.bo_clean.bv_cnt, 4066 vp->v_bufobj.bo_dirty.bv_cnt); 4067 printf(" "); 4068 lockmgr_printinfo(vp->v_vnlock); 4069 if (vp->v_data != NULL) 4070 VOP_PRINT(vp); 4071 } 4072 4073 #ifdef DDB 4074 /* 4075 * List all of the locked vnodes in the system. 4076 * Called when debugging the kernel. 4077 */ 4078 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 4079 { 4080 struct mount *mp; 4081 struct vnode *vp; 4082 4083 /* 4084 * Note: because this is DDB, we can't obey the locking semantics 4085 * for these structures, which means we could catch an inconsistent 4086 * state and dereference a nasty pointer. Not much to be done 4087 * about that. 4088 */ 4089 db_printf("Locked vnodes\n"); 4090 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4091 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4092 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4093 vn_printf(vp, "vnode "); 4094 } 4095 } 4096 } 4097 4098 /* 4099 * Show details about the given vnode. 4100 */ 4101 DB_SHOW_COMMAND(vnode, db_show_vnode) 4102 { 4103 struct vnode *vp; 4104 4105 if (!have_addr) 4106 return; 4107 vp = (struct vnode *)addr; 4108 vn_printf(vp, "vnode "); 4109 } 4110 4111 /* 4112 * Show details about the given mount point. 4113 */ 4114 DB_SHOW_COMMAND(mount, db_show_mount) 4115 { 4116 struct mount *mp; 4117 struct vfsopt *opt; 4118 struct statfs *sp; 4119 struct vnode *vp; 4120 char buf[512]; 4121 uint64_t mflags; 4122 u_int flags; 4123 4124 if (!have_addr) { 4125 /* No address given, print short info about all mount points. */ 4126 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4127 db_printf("%p %s on %s (%s)\n", mp, 4128 mp->mnt_stat.f_mntfromname, 4129 mp->mnt_stat.f_mntonname, 4130 mp->mnt_stat.f_fstypename); 4131 if (db_pager_quit) 4132 break; 4133 } 4134 db_printf("\nMore info: show mount <addr>\n"); 4135 return; 4136 } 4137 4138 mp = (struct mount *)addr; 4139 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4140 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4141 4142 buf[0] = '\0'; 4143 mflags = mp->mnt_flag; 4144 #define MNT_FLAG(flag) do { \ 4145 if (mflags & (flag)) { \ 4146 if (buf[0] != '\0') \ 4147 strlcat(buf, ", ", sizeof(buf)); \ 4148 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4149 mflags &= ~(flag); \ 4150 } \ 4151 } while (0) 4152 MNT_FLAG(MNT_RDONLY); 4153 MNT_FLAG(MNT_SYNCHRONOUS); 4154 MNT_FLAG(MNT_NOEXEC); 4155 MNT_FLAG(MNT_NOSUID); 4156 MNT_FLAG(MNT_NFS4ACLS); 4157 MNT_FLAG(MNT_UNION); 4158 MNT_FLAG(MNT_ASYNC); 4159 MNT_FLAG(MNT_SUIDDIR); 4160 MNT_FLAG(MNT_SOFTDEP); 4161 MNT_FLAG(MNT_NOSYMFOLLOW); 4162 MNT_FLAG(MNT_GJOURNAL); 4163 MNT_FLAG(MNT_MULTILABEL); 4164 MNT_FLAG(MNT_ACLS); 4165 MNT_FLAG(MNT_NOATIME); 4166 MNT_FLAG(MNT_NOCLUSTERR); 4167 MNT_FLAG(MNT_NOCLUSTERW); 4168 MNT_FLAG(MNT_SUJ); 4169 MNT_FLAG(MNT_EXRDONLY); 4170 MNT_FLAG(MNT_EXPORTED); 4171 MNT_FLAG(MNT_DEFEXPORTED); 4172 MNT_FLAG(MNT_EXPORTANON); 4173 MNT_FLAG(MNT_EXKERB); 4174 MNT_FLAG(MNT_EXPUBLIC); 4175 MNT_FLAG(MNT_LOCAL); 4176 MNT_FLAG(MNT_QUOTA); 4177 MNT_FLAG(MNT_ROOTFS); 4178 MNT_FLAG(MNT_USER); 4179 MNT_FLAG(MNT_IGNORE); 4180 MNT_FLAG(MNT_UPDATE); 4181 MNT_FLAG(MNT_DELEXPORT); 4182 MNT_FLAG(MNT_RELOAD); 4183 MNT_FLAG(MNT_FORCE); 4184 MNT_FLAG(MNT_SNAPSHOT); 4185 MNT_FLAG(MNT_BYFSID); 4186 #undef MNT_FLAG 4187 if (mflags != 0) { 4188 if (buf[0] != '\0') 4189 strlcat(buf, ", ", sizeof(buf)); 4190 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4191 "0x%016jx", mflags); 4192 } 4193 db_printf(" mnt_flag = %s\n", buf); 4194 4195 buf[0] = '\0'; 4196 flags = mp->mnt_kern_flag; 4197 #define MNT_KERN_FLAG(flag) do { \ 4198 if (flags & (flag)) { \ 4199 if (buf[0] != '\0') \ 4200 strlcat(buf, ", ", sizeof(buf)); \ 4201 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4202 flags &= ~(flag); \ 4203 } \ 4204 } while (0) 4205 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4206 MNT_KERN_FLAG(MNTK_ASYNC); 4207 MNT_KERN_FLAG(MNTK_SOFTDEP); 4208 MNT_KERN_FLAG(MNTK_DRAINING); 4209 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4210 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4211 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4212 MNT_KERN_FLAG(MNTK_NO_IOPF); 4213 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 4214 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 4215 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 4216 MNT_KERN_FLAG(MNTK_MARKER); 4217 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4218 MNT_KERN_FLAG(MNTK_FPLOOKUP); 4219 MNT_KERN_FLAG(MNTK_NOASYNC); 4220 MNT_KERN_FLAG(MNTK_UNMOUNT); 4221 MNT_KERN_FLAG(MNTK_MWAIT); 4222 MNT_KERN_FLAG(MNTK_SUSPEND); 4223 MNT_KERN_FLAG(MNTK_SUSPEND2); 4224 MNT_KERN_FLAG(MNTK_SUSPENDED); 4225 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4226 MNT_KERN_FLAG(MNTK_NOKNOTE); 4227 #undef MNT_KERN_FLAG 4228 if (flags != 0) { 4229 if (buf[0] != '\0') 4230 strlcat(buf, ", ", sizeof(buf)); 4231 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4232 "0x%08x", flags); 4233 } 4234 db_printf(" mnt_kern_flag = %s\n", buf); 4235 4236 db_printf(" mnt_opt = "); 4237 opt = TAILQ_FIRST(mp->mnt_opt); 4238 if (opt != NULL) { 4239 db_printf("%s", opt->name); 4240 opt = TAILQ_NEXT(opt, link); 4241 while (opt != NULL) { 4242 db_printf(", %s", opt->name); 4243 opt = TAILQ_NEXT(opt, link); 4244 } 4245 } 4246 db_printf("\n"); 4247 4248 sp = &mp->mnt_stat; 4249 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4250 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4251 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4252 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4253 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4254 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4255 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4256 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4257 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4258 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4259 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4260 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4261 4262 db_printf(" mnt_cred = { uid=%u ruid=%u", 4263 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4264 if (jailed(mp->mnt_cred)) 4265 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4266 db_printf(" }\n"); 4267 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4268 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4269 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4270 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4271 db_printf(" mnt_lazyvnodelistsize = %d\n", 4272 mp->mnt_lazyvnodelistsize); 4273 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4274 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4275 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4276 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4277 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4278 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4279 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4280 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4281 db_printf(" mnt_secondary_accwrites = %d\n", 4282 mp->mnt_secondary_accwrites); 4283 db_printf(" mnt_gjprovider = %s\n", 4284 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4285 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4286 4287 db_printf("\n\nList of active vnodes\n"); 4288 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4289 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4290 vn_printf(vp, "vnode "); 4291 if (db_pager_quit) 4292 break; 4293 } 4294 } 4295 db_printf("\n\nList of inactive vnodes\n"); 4296 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4297 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4298 vn_printf(vp, "vnode "); 4299 if (db_pager_quit) 4300 break; 4301 } 4302 } 4303 } 4304 #endif /* DDB */ 4305 4306 /* 4307 * Fill in a struct xvfsconf based on a struct vfsconf. 4308 */ 4309 static int 4310 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4311 { 4312 struct xvfsconf xvfsp; 4313 4314 bzero(&xvfsp, sizeof(xvfsp)); 4315 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4316 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4317 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4318 xvfsp.vfc_flags = vfsp->vfc_flags; 4319 /* 4320 * These are unused in userland, we keep them 4321 * to not break binary compatibility. 4322 */ 4323 xvfsp.vfc_vfsops = NULL; 4324 xvfsp.vfc_next = NULL; 4325 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4326 } 4327 4328 #ifdef COMPAT_FREEBSD32 4329 struct xvfsconf32 { 4330 uint32_t vfc_vfsops; 4331 char vfc_name[MFSNAMELEN]; 4332 int32_t vfc_typenum; 4333 int32_t vfc_refcount; 4334 int32_t vfc_flags; 4335 uint32_t vfc_next; 4336 }; 4337 4338 static int 4339 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4340 { 4341 struct xvfsconf32 xvfsp; 4342 4343 bzero(&xvfsp, sizeof(xvfsp)); 4344 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4345 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4346 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4347 xvfsp.vfc_flags = vfsp->vfc_flags; 4348 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4349 } 4350 #endif 4351 4352 /* 4353 * Top level filesystem related information gathering. 4354 */ 4355 static int 4356 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4357 { 4358 struct vfsconf *vfsp; 4359 int error; 4360 4361 error = 0; 4362 vfsconf_slock(); 4363 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4364 #ifdef COMPAT_FREEBSD32 4365 if (req->flags & SCTL_MASK32) 4366 error = vfsconf2x32(req, vfsp); 4367 else 4368 #endif 4369 error = vfsconf2x(req, vfsp); 4370 if (error) 4371 break; 4372 } 4373 vfsconf_sunlock(); 4374 return (error); 4375 } 4376 4377 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4378 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4379 "S,xvfsconf", "List of all configured filesystems"); 4380 4381 #ifndef BURN_BRIDGES 4382 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4383 4384 static int 4385 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4386 { 4387 int *name = (int *)arg1 - 1; /* XXX */ 4388 u_int namelen = arg2 + 1; /* XXX */ 4389 struct vfsconf *vfsp; 4390 4391 log(LOG_WARNING, "userland calling deprecated sysctl, " 4392 "please rebuild world\n"); 4393 4394 #if 1 || defined(COMPAT_PRELITE2) 4395 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4396 if (namelen == 1) 4397 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4398 #endif 4399 4400 switch (name[1]) { 4401 case VFS_MAXTYPENUM: 4402 if (namelen != 2) 4403 return (ENOTDIR); 4404 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4405 case VFS_CONF: 4406 if (namelen != 3) 4407 return (ENOTDIR); /* overloaded */ 4408 vfsconf_slock(); 4409 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4410 if (vfsp->vfc_typenum == name[2]) 4411 break; 4412 } 4413 vfsconf_sunlock(); 4414 if (vfsp == NULL) 4415 return (EOPNOTSUPP); 4416 #ifdef COMPAT_FREEBSD32 4417 if (req->flags & SCTL_MASK32) 4418 return (vfsconf2x32(req, vfsp)); 4419 else 4420 #endif 4421 return (vfsconf2x(req, vfsp)); 4422 } 4423 return (EOPNOTSUPP); 4424 } 4425 4426 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4427 CTLFLAG_MPSAFE, vfs_sysctl, 4428 "Generic filesystem"); 4429 4430 #if 1 || defined(COMPAT_PRELITE2) 4431 4432 static int 4433 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4434 { 4435 int error; 4436 struct vfsconf *vfsp; 4437 struct ovfsconf ovfs; 4438 4439 vfsconf_slock(); 4440 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4441 bzero(&ovfs, sizeof(ovfs)); 4442 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4443 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4444 ovfs.vfc_index = vfsp->vfc_typenum; 4445 ovfs.vfc_refcount = vfsp->vfc_refcount; 4446 ovfs.vfc_flags = vfsp->vfc_flags; 4447 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4448 if (error != 0) { 4449 vfsconf_sunlock(); 4450 return (error); 4451 } 4452 } 4453 vfsconf_sunlock(); 4454 return (0); 4455 } 4456 4457 #endif /* 1 || COMPAT_PRELITE2 */ 4458 #endif /* !BURN_BRIDGES */ 4459 4460 #define KINFO_VNODESLOP 10 4461 #ifdef notyet 4462 /* 4463 * Dump vnode list (via sysctl). 4464 */ 4465 /* ARGSUSED */ 4466 static int 4467 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4468 { 4469 struct xvnode *xvn; 4470 struct mount *mp; 4471 struct vnode *vp; 4472 int error, len, n; 4473 4474 /* 4475 * Stale numvnodes access is not fatal here. 4476 */ 4477 req->lock = 0; 4478 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4479 if (!req->oldptr) 4480 /* Make an estimate */ 4481 return (SYSCTL_OUT(req, 0, len)); 4482 4483 error = sysctl_wire_old_buffer(req, 0); 4484 if (error != 0) 4485 return (error); 4486 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4487 n = 0; 4488 mtx_lock(&mountlist_mtx); 4489 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4490 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4491 continue; 4492 MNT_ILOCK(mp); 4493 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4494 if (n == len) 4495 break; 4496 vref(vp); 4497 xvn[n].xv_size = sizeof *xvn; 4498 xvn[n].xv_vnode = vp; 4499 xvn[n].xv_id = 0; /* XXX compat */ 4500 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4501 XV_COPY(usecount); 4502 XV_COPY(writecount); 4503 XV_COPY(holdcnt); 4504 XV_COPY(mount); 4505 XV_COPY(numoutput); 4506 XV_COPY(type); 4507 #undef XV_COPY 4508 xvn[n].xv_flag = vp->v_vflag; 4509 4510 switch (vp->v_type) { 4511 case VREG: 4512 case VDIR: 4513 case VLNK: 4514 break; 4515 case VBLK: 4516 case VCHR: 4517 if (vp->v_rdev == NULL) { 4518 vrele(vp); 4519 continue; 4520 } 4521 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4522 break; 4523 case VSOCK: 4524 xvn[n].xv_socket = vp->v_socket; 4525 break; 4526 case VFIFO: 4527 xvn[n].xv_fifo = vp->v_fifoinfo; 4528 break; 4529 case VNON: 4530 case VBAD: 4531 default: 4532 /* shouldn't happen? */ 4533 vrele(vp); 4534 continue; 4535 } 4536 vrele(vp); 4537 ++n; 4538 } 4539 MNT_IUNLOCK(mp); 4540 mtx_lock(&mountlist_mtx); 4541 vfs_unbusy(mp); 4542 if (n == len) 4543 break; 4544 } 4545 mtx_unlock(&mountlist_mtx); 4546 4547 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4548 free(xvn, M_TEMP); 4549 return (error); 4550 } 4551 4552 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4553 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4554 ""); 4555 #endif 4556 4557 static void 4558 unmount_or_warn(struct mount *mp) 4559 { 4560 int error; 4561 4562 error = dounmount(mp, MNT_FORCE, curthread); 4563 if (error != 0) { 4564 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4565 if (error == EBUSY) 4566 printf("BUSY)\n"); 4567 else 4568 printf("%d)\n", error); 4569 } 4570 } 4571 4572 /* 4573 * Unmount all filesystems. The list is traversed in reverse order 4574 * of mounting to avoid dependencies. 4575 */ 4576 void 4577 vfs_unmountall(void) 4578 { 4579 struct mount *mp, *tmp; 4580 4581 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4582 4583 /* 4584 * Since this only runs when rebooting, it is not interlocked. 4585 */ 4586 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4587 vfs_ref(mp); 4588 4589 /* 4590 * Forcibly unmounting "/dev" before "/" would prevent clean 4591 * unmount of the latter. 4592 */ 4593 if (mp == rootdevmp) 4594 continue; 4595 4596 unmount_or_warn(mp); 4597 } 4598 4599 if (rootdevmp != NULL) 4600 unmount_or_warn(rootdevmp); 4601 } 4602 4603 static void 4604 vfs_deferred_inactive(struct vnode *vp, int lkflags) 4605 { 4606 4607 ASSERT_VI_LOCKED(vp, __func__); 4608 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, ("VI_DEFINACT still set")); 4609 if ((vp->v_iflag & VI_OWEINACT) == 0) { 4610 vdropl(vp); 4611 return; 4612 } 4613 if (vn_lock(vp, lkflags) == 0) { 4614 VI_LOCK(vp); 4615 vinactive(vp); 4616 VOP_UNLOCK(vp); 4617 vdropl(vp); 4618 return; 4619 } 4620 vdefer_inactive_unlocked(vp); 4621 } 4622 4623 static int 4624 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 4625 { 4626 4627 return (vp->v_iflag & VI_DEFINACT); 4628 } 4629 4630 static void __noinline 4631 vfs_periodic_inactive(struct mount *mp, int flags) 4632 { 4633 struct vnode *vp, *mvp; 4634 int lkflags; 4635 4636 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4637 if (flags != MNT_WAIT) 4638 lkflags |= LK_NOWAIT; 4639 4640 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 4641 if ((vp->v_iflag & VI_DEFINACT) == 0) { 4642 VI_UNLOCK(vp); 4643 continue; 4644 } 4645 vp->v_iflag &= ~VI_DEFINACT; 4646 vfs_deferred_inactive(vp, lkflags); 4647 } 4648 } 4649 4650 static inline bool 4651 vfs_want_msync(struct vnode *vp) 4652 { 4653 struct vm_object *obj; 4654 4655 /* 4656 * This test may be performed without any locks held. 4657 * We rely on vm_object's type stability. 4658 */ 4659 if (vp->v_vflag & VV_NOSYNC) 4660 return (false); 4661 obj = vp->v_object; 4662 return (obj != NULL && vm_object_mightbedirty(obj)); 4663 } 4664 4665 static int 4666 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 4667 { 4668 4669 if (vp->v_vflag & VV_NOSYNC) 4670 return (false); 4671 if (vp->v_iflag & VI_DEFINACT) 4672 return (true); 4673 return (vfs_want_msync(vp)); 4674 } 4675 4676 static void __noinline 4677 vfs_periodic_msync_inactive(struct mount *mp, int flags) 4678 { 4679 struct vnode *vp, *mvp; 4680 struct vm_object *obj; 4681 struct thread *td; 4682 int lkflags, objflags; 4683 bool seen_defer; 4684 4685 td = curthread; 4686 4687 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4688 if (flags != MNT_WAIT) { 4689 lkflags |= LK_NOWAIT; 4690 objflags = OBJPC_NOSYNC; 4691 } else { 4692 objflags = OBJPC_SYNC; 4693 } 4694 4695 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 4696 seen_defer = false; 4697 if (vp->v_iflag & VI_DEFINACT) { 4698 vp->v_iflag &= ~VI_DEFINACT; 4699 seen_defer = true; 4700 } 4701 if (!vfs_want_msync(vp)) { 4702 if (seen_defer) 4703 vfs_deferred_inactive(vp, lkflags); 4704 else 4705 VI_UNLOCK(vp); 4706 continue; 4707 } 4708 if (vget(vp, lkflags) == 0) { 4709 obj = vp->v_object; 4710 if (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0) { 4711 VM_OBJECT_WLOCK(obj); 4712 vm_object_page_clean(obj, 0, 0, objflags); 4713 VM_OBJECT_WUNLOCK(obj); 4714 } 4715 vput(vp); 4716 if (seen_defer) 4717 vdrop(vp); 4718 } else { 4719 if (seen_defer) 4720 vdefer_inactive_unlocked(vp); 4721 } 4722 } 4723 } 4724 4725 void 4726 vfs_periodic(struct mount *mp, int flags) 4727 { 4728 4729 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4730 4731 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4732 vfs_periodic_inactive(mp, flags); 4733 else 4734 vfs_periodic_msync_inactive(mp, flags); 4735 } 4736 4737 static void 4738 destroy_vpollinfo_free(struct vpollinfo *vi) 4739 { 4740 4741 knlist_destroy(&vi->vpi_selinfo.si_note); 4742 mtx_destroy(&vi->vpi_lock); 4743 uma_zfree(vnodepoll_zone, vi); 4744 } 4745 4746 static void 4747 destroy_vpollinfo(struct vpollinfo *vi) 4748 { 4749 4750 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4751 seldrain(&vi->vpi_selinfo); 4752 destroy_vpollinfo_free(vi); 4753 } 4754 4755 /* 4756 * Initialize per-vnode helper structure to hold poll-related state. 4757 */ 4758 void 4759 v_addpollinfo(struct vnode *vp) 4760 { 4761 struct vpollinfo *vi; 4762 4763 if (vp->v_pollinfo != NULL) 4764 return; 4765 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4766 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4767 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4768 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4769 VI_LOCK(vp); 4770 if (vp->v_pollinfo != NULL) { 4771 VI_UNLOCK(vp); 4772 destroy_vpollinfo_free(vi); 4773 return; 4774 } 4775 vp->v_pollinfo = vi; 4776 VI_UNLOCK(vp); 4777 } 4778 4779 /* 4780 * Record a process's interest in events which might happen to 4781 * a vnode. Because poll uses the historic select-style interface 4782 * internally, this routine serves as both the ``check for any 4783 * pending events'' and the ``record my interest in future events'' 4784 * functions. (These are done together, while the lock is held, 4785 * to avoid race conditions.) 4786 */ 4787 int 4788 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4789 { 4790 4791 v_addpollinfo(vp); 4792 mtx_lock(&vp->v_pollinfo->vpi_lock); 4793 if (vp->v_pollinfo->vpi_revents & events) { 4794 /* 4795 * This leaves events we are not interested 4796 * in available for the other process which 4797 * which presumably had requested them 4798 * (otherwise they would never have been 4799 * recorded). 4800 */ 4801 events &= vp->v_pollinfo->vpi_revents; 4802 vp->v_pollinfo->vpi_revents &= ~events; 4803 4804 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4805 return (events); 4806 } 4807 vp->v_pollinfo->vpi_events |= events; 4808 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4809 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4810 return (0); 4811 } 4812 4813 /* 4814 * Routine to create and manage a filesystem syncer vnode. 4815 */ 4816 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4817 static int sync_fsync(struct vop_fsync_args *); 4818 static int sync_inactive(struct vop_inactive_args *); 4819 static int sync_reclaim(struct vop_reclaim_args *); 4820 4821 static struct vop_vector sync_vnodeops = { 4822 .vop_bypass = VOP_EOPNOTSUPP, 4823 .vop_close = sync_close, /* close */ 4824 .vop_fsync = sync_fsync, /* fsync */ 4825 .vop_inactive = sync_inactive, /* inactive */ 4826 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 4827 .vop_reclaim = sync_reclaim, /* reclaim */ 4828 .vop_lock1 = vop_stdlock, /* lock */ 4829 .vop_unlock = vop_stdunlock, /* unlock */ 4830 .vop_islocked = vop_stdislocked, /* islocked */ 4831 }; 4832 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 4833 4834 /* 4835 * Create a new filesystem syncer vnode for the specified mount point. 4836 */ 4837 void 4838 vfs_allocate_syncvnode(struct mount *mp) 4839 { 4840 struct vnode *vp; 4841 struct bufobj *bo; 4842 static long start, incr, next; 4843 int error; 4844 4845 /* Allocate a new vnode */ 4846 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4847 if (error != 0) 4848 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4849 vp->v_type = VNON; 4850 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4851 vp->v_vflag |= VV_FORCEINSMQ; 4852 error = insmntque(vp, mp); 4853 if (error != 0) 4854 panic("vfs_allocate_syncvnode: insmntque() failed"); 4855 vp->v_vflag &= ~VV_FORCEINSMQ; 4856 VOP_UNLOCK(vp); 4857 /* 4858 * Place the vnode onto the syncer worklist. We attempt to 4859 * scatter them about on the list so that they will go off 4860 * at evenly distributed times even if all the filesystems 4861 * are mounted at once. 4862 */ 4863 next += incr; 4864 if (next == 0 || next > syncer_maxdelay) { 4865 start /= 2; 4866 incr /= 2; 4867 if (start == 0) { 4868 start = syncer_maxdelay / 2; 4869 incr = syncer_maxdelay; 4870 } 4871 next = start; 4872 } 4873 bo = &vp->v_bufobj; 4874 BO_LOCK(bo); 4875 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4876 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4877 mtx_lock(&sync_mtx); 4878 sync_vnode_count++; 4879 if (mp->mnt_syncer == NULL) { 4880 mp->mnt_syncer = vp; 4881 vp = NULL; 4882 } 4883 mtx_unlock(&sync_mtx); 4884 BO_UNLOCK(bo); 4885 if (vp != NULL) { 4886 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4887 vgone(vp); 4888 vput(vp); 4889 } 4890 } 4891 4892 void 4893 vfs_deallocate_syncvnode(struct mount *mp) 4894 { 4895 struct vnode *vp; 4896 4897 mtx_lock(&sync_mtx); 4898 vp = mp->mnt_syncer; 4899 if (vp != NULL) 4900 mp->mnt_syncer = NULL; 4901 mtx_unlock(&sync_mtx); 4902 if (vp != NULL) 4903 vrele(vp); 4904 } 4905 4906 /* 4907 * Do a lazy sync of the filesystem. 4908 */ 4909 static int 4910 sync_fsync(struct vop_fsync_args *ap) 4911 { 4912 struct vnode *syncvp = ap->a_vp; 4913 struct mount *mp = syncvp->v_mount; 4914 int error, save; 4915 struct bufobj *bo; 4916 4917 /* 4918 * We only need to do something if this is a lazy evaluation. 4919 */ 4920 if (ap->a_waitfor != MNT_LAZY) 4921 return (0); 4922 4923 /* 4924 * Move ourselves to the back of the sync list. 4925 */ 4926 bo = &syncvp->v_bufobj; 4927 BO_LOCK(bo); 4928 vn_syncer_add_to_worklist(bo, syncdelay); 4929 BO_UNLOCK(bo); 4930 4931 /* 4932 * Walk the list of vnodes pushing all that are dirty and 4933 * not already on the sync list. 4934 */ 4935 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4936 return (0); 4937 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4938 vfs_unbusy(mp); 4939 return (0); 4940 } 4941 save = curthread_pflags_set(TDP_SYNCIO); 4942 /* 4943 * The filesystem at hand may be idle with free vnodes stored in the 4944 * batch. Return them instead of letting them stay there indefinitely. 4945 */ 4946 vfs_periodic(mp, MNT_NOWAIT); 4947 error = VFS_SYNC(mp, MNT_LAZY); 4948 curthread_pflags_restore(save); 4949 vn_finished_write(mp); 4950 vfs_unbusy(mp); 4951 return (error); 4952 } 4953 4954 /* 4955 * The syncer vnode is no referenced. 4956 */ 4957 static int 4958 sync_inactive(struct vop_inactive_args *ap) 4959 { 4960 4961 vgone(ap->a_vp); 4962 return (0); 4963 } 4964 4965 /* 4966 * The syncer vnode is no longer needed and is being decommissioned. 4967 * 4968 * Modifications to the worklist must be protected by sync_mtx. 4969 */ 4970 static int 4971 sync_reclaim(struct vop_reclaim_args *ap) 4972 { 4973 struct vnode *vp = ap->a_vp; 4974 struct bufobj *bo; 4975 4976 bo = &vp->v_bufobj; 4977 BO_LOCK(bo); 4978 mtx_lock(&sync_mtx); 4979 if (vp->v_mount->mnt_syncer == vp) 4980 vp->v_mount->mnt_syncer = NULL; 4981 if (bo->bo_flag & BO_ONWORKLST) { 4982 LIST_REMOVE(bo, bo_synclist); 4983 syncer_worklist_len--; 4984 sync_vnode_count--; 4985 bo->bo_flag &= ~BO_ONWORKLST; 4986 } 4987 mtx_unlock(&sync_mtx); 4988 BO_UNLOCK(bo); 4989 4990 return (0); 4991 } 4992 4993 int 4994 vn_need_pageq_flush(struct vnode *vp) 4995 { 4996 struct vm_object *obj; 4997 int need; 4998 4999 MPASS(mtx_owned(VI_MTX(vp))); 5000 need = 0; 5001 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5002 vm_object_mightbedirty(obj)) 5003 need = 1; 5004 return (need); 5005 } 5006 5007 /* 5008 * Check if vnode represents a disk device 5009 */ 5010 bool 5011 vn_isdisk_error(struct vnode *vp, int *errp) 5012 { 5013 int error; 5014 5015 if (vp->v_type != VCHR) { 5016 error = ENOTBLK; 5017 goto out; 5018 } 5019 error = 0; 5020 dev_lock(); 5021 if (vp->v_rdev == NULL) 5022 error = ENXIO; 5023 else if (vp->v_rdev->si_devsw == NULL) 5024 error = ENXIO; 5025 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5026 error = ENOTBLK; 5027 dev_unlock(); 5028 out: 5029 *errp = error; 5030 return (error == 0); 5031 } 5032 5033 bool 5034 vn_isdisk(struct vnode *vp) 5035 { 5036 int error; 5037 5038 return (vn_isdisk_error(vp, &error)); 5039 } 5040 5041 /* 5042 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see 5043 * the comment above cache_fplookup for details. 5044 */ 5045 int 5046 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred) 5047 { 5048 5049 VFS_SMR_ASSERT_ENTERED(); 5050 5051 /* Check the owner. */ 5052 if (cred->cr_uid == file_uid) { 5053 if (file_mode & S_IXUSR) 5054 return (0); 5055 goto out_error; 5056 } 5057 5058 /* Otherwise, check the groups (first match) */ 5059 if (groupmember(file_gid, cred)) { 5060 if (file_mode & S_IXGRP) 5061 return (0); 5062 goto out_error; 5063 } 5064 5065 /* Otherwise, check everyone else. */ 5066 if (file_mode & S_IXOTH) 5067 return (0); 5068 out_error: 5069 /* 5070 * Permission check failed. 5071 * 5072 * vaccess() calls priv_check_cred which in turn can descent into MAC 5073 * modules overriding this result. It's quite unclear what semantics 5074 * are allowed for them to operate, thus for safety we don't call them 5075 * from within the SMR section. This also means if any such modules 5076 * are present, we have to let the regular lookup decide. 5077 */ 5078 if (__predict_false(mac_priv_check_fp_flag || mac_priv_grant_fp_flag)) 5079 return (EAGAIN); 5080 return (EACCES); 5081 } 5082 5083 /* 5084 * Common filesystem object access control check routine. Accepts a 5085 * vnode's type, "mode", uid and gid, requested access mode, and credentials. 5086 * Returns 0 on success, or an errno on failure. 5087 */ 5088 int 5089 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5090 accmode_t accmode, struct ucred *cred) 5091 { 5092 accmode_t dac_granted; 5093 accmode_t priv_granted; 5094 5095 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5096 ("invalid bit in accmode")); 5097 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5098 ("VAPPEND without VWRITE")); 5099 5100 /* 5101 * Look for a normal, non-privileged way to access the file/directory 5102 * as requested. If it exists, go with that. 5103 */ 5104 5105 dac_granted = 0; 5106 5107 /* Check the owner. */ 5108 if (cred->cr_uid == file_uid) { 5109 dac_granted |= VADMIN; 5110 if (file_mode & S_IXUSR) 5111 dac_granted |= VEXEC; 5112 if (file_mode & S_IRUSR) 5113 dac_granted |= VREAD; 5114 if (file_mode & S_IWUSR) 5115 dac_granted |= (VWRITE | VAPPEND); 5116 5117 if ((accmode & dac_granted) == accmode) 5118 return (0); 5119 5120 goto privcheck; 5121 } 5122 5123 /* Otherwise, check the groups (first match) */ 5124 if (groupmember(file_gid, cred)) { 5125 if (file_mode & S_IXGRP) 5126 dac_granted |= VEXEC; 5127 if (file_mode & S_IRGRP) 5128 dac_granted |= VREAD; 5129 if (file_mode & S_IWGRP) 5130 dac_granted |= (VWRITE | VAPPEND); 5131 5132 if ((accmode & dac_granted) == accmode) 5133 return (0); 5134 5135 goto privcheck; 5136 } 5137 5138 /* Otherwise, check everyone else. */ 5139 if (file_mode & S_IXOTH) 5140 dac_granted |= VEXEC; 5141 if (file_mode & S_IROTH) 5142 dac_granted |= VREAD; 5143 if (file_mode & S_IWOTH) 5144 dac_granted |= (VWRITE | VAPPEND); 5145 if ((accmode & dac_granted) == accmode) 5146 return (0); 5147 5148 privcheck: 5149 /* 5150 * Build a privilege mask to determine if the set of privileges 5151 * satisfies the requirements when combined with the granted mask 5152 * from above. For each privilege, if the privilege is required, 5153 * bitwise or the request type onto the priv_granted mask. 5154 */ 5155 priv_granted = 0; 5156 5157 if (type == VDIR) { 5158 /* 5159 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5160 * requests, instead of PRIV_VFS_EXEC. 5161 */ 5162 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5163 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5164 priv_granted |= VEXEC; 5165 } else { 5166 /* 5167 * Ensure that at least one execute bit is on. Otherwise, 5168 * a privileged user will always succeed, and we don't want 5169 * this to happen unless the file really is executable. 5170 */ 5171 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5172 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5173 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5174 priv_granted |= VEXEC; 5175 } 5176 5177 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5178 !priv_check_cred(cred, PRIV_VFS_READ)) 5179 priv_granted |= VREAD; 5180 5181 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5182 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5183 priv_granted |= (VWRITE | VAPPEND); 5184 5185 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5186 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5187 priv_granted |= VADMIN; 5188 5189 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5190 return (0); 5191 } 5192 5193 return ((accmode & VADMIN) ? EPERM : EACCES); 5194 } 5195 5196 /* 5197 * Credential check based on process requesting service, and per-attribute 5198 * permissions. 5199 */ 5200 int 5201 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5202 struct thread *td, accmode_t accmode) 5203 { 5204 5205 /* 5206 * Kernel-invoked always succeeds. 5207 */ 5208 if (cred == NOCRED) 5209 return (0); 5210 5211 /* 5212 * Do not allow privileged processes in jail to directly manipulate 5213 * system attributes. 5214 */ 5215 switch (attrnamespace) { 5216 case EXTATTR_NAMESPACE_SYSTEM: 5217 /* Potentially should be: return (EPERM); */ 5218 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5219 case EXTATTR_NAMESPACE_USER: 5220 return (VOP_ACCESS(vp, accmode, cred, td)); 5221 default: 5222 return (EPERM); 5223 } 5224 } 5225 5226 #ifdef DEBUG_VFS_LOCKS 5227 /* 5228 * This only exists to suppress warnings from unlocked specfs accesses. It is 5229 * no longer ok to have an unlocked VFS. 5230 */ 5231 #define IGNORE_LOCK(vp) (KERNEL_PANICKED() || (vp) == NULL || \ 5232 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 5233 5234 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5235 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5236 "Drop into debugger on lock violation"); 5237 5238 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5239 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5240 0, "Check for interlock across VOPs"); 5241 5242 int vfs_badlock_print = 1; /* Print lock violations. */ 5243 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5244 0, "Print lock violations"); 5245 5246 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5247 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5248 0, "Print vnode details on lock violations"); 5249 5250 #ifdef KDB 5251 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5252 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5253 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5254 #endif 5255 5256 static void 5257 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5258 { 5259 5260 #ifdef KDB 5261 if (vfs_badlock_backtrace) 5262 kdb_backtrace(); 5263 #endif 5264 if (vfs_badlock_vnode) 5265 vn_printf(vp, "vnode "); 5266 if (vfs_badlock_print) 5267 printf("%s: %p %s\n", str, (void *)vp, msg); 5268 if (vfs_badlock_ddb) 5269 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5270 } 5271 5272 void 5273 assert_vi_locked(struct vnode *vp, const char *str) 5274 { 5275 5276 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5277 vfs_badlock("interlock is not locked but should be", str, vp); 5278 } 5279 5280 void 5281 assert_vi_unlocked(struct vnode *vp, const char *str) 5282 { 5283 5284 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5285 vfs_badlock("interlock is locked but should not be", str, vp); 5286 } 5287 5288 void 5289 assert_vop_locked(struct vnode *vp, const char *str) 5290 { 5291 int locked; 5292 5293 if (!IGNORE_LOCK(vp)) { 5294 locked = VOP_ISLOCKED(vp); 5295 if (locked == 0 || locked == LK_EXCLOTHER) 5296 vfs_badlock("is not locked but should be", str, vp); 5297 } 5298 } 5299 5300 void 5301 assert_vop_unlocked(struct vnode *vp, const char *str) 5302 { 5303 5304 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5305 vfs_badlock("is locked but should not be", str, vp); 5306 } 5307 5308 void 5309 assert_vop_elocked(struct vnode *vp, const char *str) 5310 { 5311 5312 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5313 vfs_badlock("is not exclusive locked but should be", str, vp); 5314 } 5315 #endif /* DEBUG_VFS_LOCKS */ 5316 5317 void 5318 vop_rename_fail(struct vop_rename_args *ap) 5319 { 5320 5321 if (ap->a_tvp != NULL) 5322 vput(ap->a_tvp); 5323 if (ap->a_tdvp == ap->a_tvp) 5324 vrele(ap->a_tdvp); 5325 else 5326 vput(ap->a_tdvp); 5327 vrele(ap->a_fdvp); 5328 vrele(ap->a_fvp); 5329 } 5330 5331 void 5332 vop_rename_pre(void *ap) 5333 { 5334 struct vop_rename_args *a = ap; 5335 5336 #ifdef DEBUG_VFS_LOCKS 5337 if (a->a_tvp) 5338 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5339 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5340 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5341 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5342 5343 /* Check the source (from). */ 5344 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5345 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5346 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5347 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5348 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5349 5350 /* Check the target. */ 5351 if (a->a_tvp) 5352 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5353 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5354 #endif 5355 /* 5356 * It may be tempting to add vn_seqc_write_begin/end calls here and 5357 * in vop_rename_post but that's not going to work out since some 5358 * filesystems relookup vnodes mid-rename. This is probably a bug. 5359 * 5360 * For now filesystems are expected to do the relevant calls after they 5361 * decide what vnodes to operate on. 5362 */ 5363 if (a->a_tdvp != a->a_fdvp) 5364 vhold(a->a_fdvp); 5365 if (a->a_tvp != a->a_fvp) 5366 vhold(a->a_fvp); 5367 vhold(a->a_tdvp); 5368 if (a->a_tvp) 5369 vhold(a->a_tvp); 5370 } 5371 5372 #ifdef DEBUG_VFS_LOCKS 5373 void 5374 vop_fplookup_vexec_debugpre(void *ap __unused) 5375 { 5376 5377 VFS_SMR_ASSERT_ENTERED(); 5378 } 5379 5380 void 5381 vop_fplookup_vexec_debugpost(void *ap __unused, int rc __unused) 5382 { 5383 5384 VFS_SMR_ASSERT_ENTERED(); 5385 } 5386 5387 void 5388 vop_strategy_debugpre(void *ap) 5389 { 5390 struct vop_strategy_args *a; 5391 struct buf *bp; 5392 5393 a = ap; 5394 bp = a->a_bp; 5395 5396 /* 5397 * Cluster ops lock their component buffers but not the IO container. 5398 */ 5399 if ((bp->b_flags & B_CLUSTER) != 0) 5400 return; 5401 5402 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5403 if (vfs_badlock_print) 5404 printf( 5405 "VOP_STRATEGY: bp is not locked but should be\n"); 5406 if (vfs_badlock_ddb) 5407 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5408 } 5409 } 5410 5411 void 5412 vop_lock_debugpre(void *ap) 5413 { 5414 struct vop_lock1_args *a = ap; 5415 5416 if ((a->a_flags & LK_INTERLOCK) == 0) 5417 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5418 else 5419 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5420 } 5421 5422 void 5423 vop_lock_debugpost(void *ap, int rc) 5424 { 5425 struct vop_lock1_args *a = ap; 5426 5427 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5428 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5429 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5430 } 5431 5432 void 5433 vop_unlock_debugpre(void *ap) 5434 { 5435 struct vop_unlock_args *a = ap; 5436 5437 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5438 } 5439 5440 void 5441 vop_need_inactive_debugpre(void *ap) 5442 { 5443 struct vop_need_inactive_args *a = ap; 5444 5445 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5446 } 5447 5448 void 5449 vop_need_inactive_debugpost(void *ap, int rc) 5450 { 5451 struct vop_need_inactive_args *a = ap; 5452 5453 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5454 } 5455 #endif 5456 5457 void 5458 vop_create_pre(void *ap) 5459 { 5460 struct vop_create_args *a; 5461 struct vnode *dvp; 5462 5463 a = ap; 5464 dvp = a->a_dvp; 5465 vn_seqc_write_begin(dvp); 5466 } 5467 5468 void 5469 vop_create_post(void *ap, int rc) 5470 { 5471 struct vop_create_args *a; 5472 struct vnode *dvp; 5473 5474 a = ap; 5475 dvp = a->a_dvp; 5476 vn_seqc_write_end(dvp); 5477 if (!rc) 5478 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5479 } 5480 5481 void 5482 vop_whiteout_pre(void *ap) 5483 { 5484 struct vop_whiteout_args *a; 5485 struct vnode *dvp; 5486 5487 a = ap; 5488 dvp = a->a_dvp; 5489 vn_seqc_write_begin(dvp); 5490 } 5491 5492 void 5493 vop_whiteout_post(void *ap, int rc) 5494 { 5495 struct vop_whiteout_args *a; 5496 struct vnode *dvp; 5497 5498 a = ap; 5499 dvp = a->a_dvp; 5500 vn_seqc_write_end(dvp); 5501 } 5502 5503 void 5504 vop_deleteextattr_pre(void *ap) 5505 { 5506 struct vop_deleteextattr_args *a; 5507 struct vnode *vp; 5508 5509 a = ap; 5510 vp = a->a_vp; 5511 vn_seqc_write_begin(vp); 5512 } 5513 5514 void 5515 vop_deleteextattr_post(void *ap, int rc) 5516 { 5517 struct vop_deleteextattr_args *a; 5518 struct vnode *vp; 5519 5520 a = ap; 5521 vp = a->a_vp; 5522 vn_seqc_write_end(vp); 5523 if (!rc) 5524 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5525 } 5526 5527 void 5528 vop_link_pre(void *ap) 5529 { 5530 struct vop_link_args *a; 5531 struct vnode *vp, *tdvp; 5532 5533 a = ap; 5534 vp = a->a_vp; 5535 tdvp = a->a_tdvp; 5536 vn_seqc_write_begin(vp); 5537 vn_seqc_write_begin(tdvp); 5538 } 5539 5540 void 5541 vop_link_post(void *ap, int rc) 5542 { 5543 struct vop_link_args *a; 5544 struct vnode *vp, *tdvp; 5545 5546 a = ap; 5547 vp = a->a_vp; 5548 tdvp = a->a_tdvp; 5549 vn_seqc_write_end(vp); 5550 vn_seqc_write_end(tdvp); 5551 if (!rc) { 5552 VFS_KNOTE_LOCKED(vp, NOTE_LINK); 5553 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE); 5554 } 5555 } 5556 5557 void 5558 vop_mkdir_pre(void *ap) 5559 { 5560 struct vop_mkdir_args *a; 5561 struct vnode *dvp; 5562 5563 a = ap; 5564 dvp = a->a_dvp; 5565 vn_seqc_write_begin(dvp); 5566 } 5567 5568 void 5569 vop_mkdir_post(void *ap, int rc) 5570 { 5571 struct vop_mkdir_args *a; 5572 struct vnode *dvp; 5573 5574 a = ap; 5575 dvp = a->a_dvp; 5576 vn_seqc_write_end(dvp); 5577 if (!rc) 5578 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 5579 } 5580 5581 void 5582 vop_mknod_pre(void *ap) 5583 { 5584 struct vop_mknod_args *a; 5585 struct vnode *dvp; 5586 5587 a = ap; 5588 dvp = a->a_dvp; 5589 vn_seqc_write_begin(dvp); 5590 } 5591 5592 void 5593 vop_mknod_post(void *ap, int rc) 5594 { 5595 struct vop_mknod_args *a; 5596 struct vnode *dvp; 5597 5598 a = ap; 5599 dvp = a->a_dvp; 5600 vn_seqc_write_end(dvp); 5601 if (!rc) 5602 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5603 } 5604 5605 void 5606 vop_reclaim_post(void *ap, int rc) 5607 { 5608 struct vop_reclaim_args *a; 5609 struct vnode *vp; 5610 5611 a = ap; 5612 vp = a->a_vp; 5613 ASSERT_VOP_IN_SEQC(vp); 5614 if (!rc) 5615 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE); 5616 } 5617 5618 void 5619 vop_remove_pre(void *ap) 5620 { 5621 struct vop_remove_args *a; 5622 struct vnode *dvp, *vp; 5623 5624 a = ap; 5625 dvp = a->a_dvp; 5626 vp = a->a_vp; 5627 vn_seqc_write_begin(dvp); 5628 vn_seqc_write_begin(vp); 5629 } 5630 5631 void 5632 vop_remove_post(void *ap, int rc) 5633 { 5634 struct vop_remove_args *a; 5635 struct vnode *dvp, *vp; 5636 5637 a = ap; 5638 dvp = a->a_dvp; 5639 vp = a->a_vp; 5640 vn_seqc_write_end(dvp); 5641 vn_seqc_write_end(vp); 5642 if (!rc) { 5643 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5644 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 5645 } 5646 } 5647 5648 void 5649 vop_rename_post(void *ap, int rc) 5650 { 5651 struct vop_rename_args *a = ap; 5652 long hint; 5653 5654 if (!rc) { 5655 hint = NOTE_WRITE; 5656 if (a->a_fdvp == a->a_tdvp) { 5657 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5658 hint |= NOTE_LINK; 5659 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5660 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5661 } else { 5662 hint |= NOTE_EXTEND; 5663 if (a->a_fvp->v_type == VDIR) 5664 hint |= NOTE_LINK; 5665 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5666 5667 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5668 a->a_tvp->v_type == VDIR) 5669 hint &= ~NOTE_LINK; 5670 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5671 } 5672 5673 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5674 if (a->a_tvp) 5675 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5676 } 5677 if (a->a_tdvp != a->a_fdvp) 5678 vdrop(a->a_fdvp); 5679 if (a->a_tvp != a->a_fvp) 5680 vdrop(a->a_fvp); 5681 vdrop(a->a_tdvp); 5682 if (a->a_tvp) 5683 vdrop(a->a_tvp); 5684 } 5685 5686 void 5687 vop_rmdir_pre(void *ap) 5688 { 5689 struct vop_rmdir_args *a; 5690 struct vnode *dvp, *vp; 5691 5692 a = ap; 5693 dvp = a->a_dvp; 5694 vp = a->a_vp; 5695 vn_seqc_write_begin(dvp); 5696 vn_seqc_write_begin(vp); 5697 } 5698 5699 void 5700 vop_rmdir_post(void *ap, int rc) 5701 { 5702 struct vop_rmdir_args *a; 5703 struct vnode *dvp, *vp; 5704 5705 a = ap; 5706 dvp = a->a_dvp; 5707 vp = a->a_vp; 5708 vn_seqc_write_end(dvp); 5709 vn_seqc_write_end(vp); 5710 if (!rc) { 5711 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 5712 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 5713 } 5714 } 5715 5716 void 5717 vop_setattr_pre(void *ap) 5718 { 5719 struct vop_setattr_args *a; 5720 struct vnode *vp; 5721 5722 a = ap; 5723 vp = a->a_vp; 5724 vn_seqc_write_begin(vp); 5725 } 5726 5727 void 5728 vop_setattr_post(void *ap, int rc) 5729 { 5730 struct vop_setattr_args *a; 5731 struct vnode *vp; 5732 5733 a = ap; 5734 vp = a->a_vp; 5735 vn_seqc_write_end(vp); 5736 if (!rc) 5737 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 5738 } 5739 5740 void 5741 vop_setacl_pre(void *ap) 5742 { 5743 struct vop_setacl_args *a; 5744 struct vnode *vp; 5745 5746 a = ap; 5747 vp = a->a_vp; 5748 vn_seqc_write_begin(vp); 5749 } 5750 5751 void 5752 vop_setacl_post(void *ap, int rc __unused) 5753 { 5754 struct vop_setacl_args *a; 5755 struct vnode *vp; 5756 5757 a = ap; 5758 vp = a->a_vp; 5759 vn_seqc_write_end(vp); 5760 } 5761 5762 void 5763 vop_setextattr_pre(void *ap) 5764 { 5765 struct vop_setextattr_args *a; 5766 struct vnode *vp; 5767 5768 a = ap; 5769 vp = a->a_vp; 5770 vn_seqc_write_begin(vp); 5771 } 5772 5773 void 5774 vop_setextattr_post(void *ap, int rc) 5775 { 5776 struct vop_setextattr_args *a; 5777 struct vnode *vp; 5778 5779 a = ap; 5780 vp = a->a_vp; 5781 vn_seqc_write_end(vp); 5782 if (!rc) 5783 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 5784 } 5785 5786 void 5787 vop_symlink_pre(void *ap) 5788 { 5789 struct vop_symlink_args *a; 5790 struct vnode *dvp; 5791 5792 a = ap; 5793 dvp = a->a_dvp; 5794 vn_seqc_write_begin(dvp); 5795 } 5796 5797 void 5798 vop_symlink_post(void *ap, int rc) 5799 { 5800 struct vop_symlink_args *a; 5801 struct vnode *dvp; 5802 5803 a = ap; 5804 dvp = a->a_dvp; 5805 vn_seqc_write_end(dvp); 5806 if (!rc) 5807 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5808 } 5809 5810 void 5811 vop_open_post(void *ap, int rc) 5812 { 5813 struct vop_open_args *a = ap; 5814 5815 if (!rc) 5816 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5817 } 5818 5819 void 5820 vop_close_post(void *ap, int rc) 5821 { 5822 struct vop_close_args *a = ap; 5823 5824 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5825 !VN_IS_DOOMED(a->a_vp))) { 5826 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5827 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5828 } 5829 } 5830 5831 void 5832 vop_read_post(void *ap, int rc) 5833 { 5834 struct vop_read_args *a = ap; 5835 5836 if (!rc) 5837 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5838 } 5839 5840 void 5841 vop_readdir_post(void *ap, int rc) 5842 { 5843 struct vop_readdir_args *a = ap; 5844 5845 if (!rc) 5846 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5847 } 5848 5849 static struct knlist fs_knlist; 5850 5851 static void 5852 vfs_event_init(void *arg) 5853 { 5854 knlist_init_mtx(&fs_knlist, NULL); 5855 } 5856 /* XXX - correct order? */ 5857 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5858 5859 void 5860 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5861 { 5862 5863 KNOTE_UNLOCKED(&fs_knlist, event); 5864 } 5865 5866 static int filt_fsattach(struct knote *kn); 5867 static void filt_fsdetach(struct knote *kn); 5868 static int filt_fsevent(struct knote *kn, long hint); 5869 5870 struct filterops fs_filtops = { 5871 .f_isfd = 0, 5872 .f_attach = filt_fsattach, 5873 .f_detach = filt_fsdetach, 5874 .f_event = filt_fsevent 5875 }; 5876 5877 static int 5878 filt_fsattach(struct knote *kn) 5879 { 5880 5881 kn->kn_flags |= EV_CLEAR; 5882 knlist_add(&fs_knlist, kn, 0); 5883 return (0); 5884 } 5885 5886 static void 5887 filt_fsdetach(struct knote *kn) 5888 { 5889 5890 knlist_remove(&fs_knlist, kn, 0); 5891 } 5892 5893 static int 5894 filt_fsevent(struct knote *kn, long hint) 5895 { 5896 5897 kn->kn_fflags |= hint; 5898 return (kn->kn_fflags != 0); 5899 } 5900 5901 static int 5902 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5903 { 5904 struct vfsidctl vc; 5905 int error; 5906 struct mount *mp; 5907 5908 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5909 if (error) 5910 return (error); 5911 if (vc.vc_vers != VFS_CTL_VERS1) 5912 return (EINVAL); 5913 mp = vfs_getvfs(&vc.vc_fsid); 5914 if (mp == NULL) 5915 return (ENOENT); 5916 /* ensure that a specific sysctl goes to the right filesystem. */ 5917 if (strcmp(vc.vc_fstypename, "*") != 0 && 5918 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5919 vfs_rel(mp); 5920 return (EINVAL); 5921 } 5922 VCTLTOREQ(&vc, req); 5923 error = VFS_SYSCTL(mp, vc.vc_op, req); 5924 vfs_rel(mp); 5925 return (error); 5926 } 5927 5928 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 5929 NULL, 0, sysctl_vfs_ctl, "", 5930 "Sysctl by fsid"); 5931 5932 /* 5933 * Function to initialize a va_filerev field sensibly. 5934 * XXX: Wouldn't a random number make a lot more sense ?? 5935 */ 5936 u_quad_t 5937 init_va_filerev(void) 5938 { 5939 struct bintime bt; 5940 5941 getbinuptime(&bt); 5942 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5943 } 5944 5945 static int filt_vfsread(struct knote *kn, long hint); 5946 static int filt_vfswrite(struct knote *kn, long hint); 5947 static int filt_vfsvnode(struct knote *kn, long hint); 5948 static void filt_vfsdetach(struct knote *kn); 5949 static struct filterops vfsread_filtops = { 5950 .f_isfd = 1, 5951 .f_detach = filt_vfsdetach, 5952 .f_event = filt_vfsread 5953 }; 5954 static struct filterops vfswrite_filtops = { 5955 .f_isfd = 1, 5956 .f_detach = filt_vfsdetach, 5957 .f_event = filt_vfswrite 5958 }; 5959 static struct filterops vfsvnode_filtops = { 5960 .f_isfd = 1, 5961 .f_detach = filt_vfsdetach, 5962 .f_event = filt_vfsvnode 5963 }; 5964 5965 static void 5966 vfs_knllock(void *arg) 5967 { 5968 struct vnode *vp = arg; 5969 5970 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5971 } 5972 5973 static void 5974 vfs_knlunlock(void *arg) 5975 { 5976 struct vnode *vp = arg; 5977 5978 VOP_UNLOCK(vp); 5979 } 5980 5981 static void 5982 vfs_knl_assert_locked(void *arg) 5983 { 5984 #ifdef DEBUG_VFS_LOCKS 5985 struct vnode *vp = arg; 5986 5987 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5988 #endif 5989 } 5990 5991 static void 5992 vfs_knl_assert_unlocked(void *arg) 5993 { 5994 #ifdef DEBUG_VFS_LOCKS 5995 struct vnode *vp = arg; 5996 5997 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5998 #endif 5999 } 6000 6001 int 6002 vfs_kqfilter(struct vop_kqfilter_args *ap) 6003 { 6004 struct vnode *vp = ap->a_vp; 6005 struct knote *kn = ap->a_kn; 6006 struct knlist *knl; 6007 6008 switch (kn->kn_filter) { 6009 case EVFILT_READ: 6010 kn->kn_fop = &vfsread_filtops; 6011 break; 6012 case EVFILT_WRITE: 6013 kn->kn_fop = &vfswrite_filtops; 6014 break; 6015 case EVFILT_VNODE: 6016 kn->kn_fop = &vfsvnode_filtops; 6017 break; 6018 default: 6019 return (EINVAL); 6020 } 6021 6022 kn->kn_hook = (caddr_t)vp; 6023 6024 v_addpollinfo(vp); 6025 if (vp->v_pollinfo == NULL) 6026 return (ENOMEM); 6027 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 6028 vhold(vp); 6029 knlist_add(knl, kn, 0); 6030 6031 return (0); 6032 } 6033 6034 /* 6035 * Detach knote from vnode 6036 */ 6037 static void 6038 filt_vfsdetach(struct knote *kn) 6039 { 6040 struct vnode *vp = (struct vnode *)kn->kn_hook; 6041 6042 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 6043 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 6044 vdrop(vp); 6045 } 6046 6047 /*ARGSUSED*/ 6048 static int 6049 filt_vfsread(struct knote *kn, long hint) 6050 { 6051 struct vnode *vp = (struct vnode *)kn->kn_hook; 6052 struct vattr va; 6053 int res; 6054 6055 /* 6056 * filesystem is gone, so set the EOF flag and schedule 6057 * the knote for deletion. 6058 */ 6059 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6060 VI_LOCK(vp); 6061 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6062 VI_UNLOCK(vp); 6063 return (1); 6064 } 6065 6066 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 6067 return (0); 6068 6069 VI_LOCK(vp); 6070 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 6071 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 6072 VI_UNLOCK(vp); 6073 return (res); 6074 } 6075 6076 /*ARGSUSED*/ 6077 static int 6078 filt_vfswrite(struct knote *kn, long hint) 6079 { 6080 struct vnode *vp = (struct vnode *)kn->kn_hook; 6081 6082 VI_LOCK(vp); 6083 6084 /* 6085 * filesystem is gone, so set the EOF flag and schedule 6086 * the knote for deletion. 6087 */ 6088 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 6089 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6090 6091 kn->kn_data = 0; 6092 VI_UNLOCK(vp); 6093 return (1); 6094 } 6095 6096 static int 6097 filt_vfsvnode(struct knote *kn, long hint) 6098 { 6099 struct vnode *vp = (struct vnode *)kn->kn_hook; 6100 int res; 6101 6102 VI_LOCK(vp); 6103 if (kn->kn_sfflags & hint) 6104 kn->kn_fflags |= hint; 6105 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6106 kn->kn_flags |= EV_EOF; 6107 VI_UNLOCK(vp); 6108 return (1); 6109 } 6110 res = (kn->kn_fflags != 0); 6111 VI_UNLOCK(vp); 6112 return (res); 6113 } 6114 6115 /* 6116 * Returns whether the directory is empty or not. 6117 * If it is empty, the return value is 0; otherwise 6118 * the return value is an error value (which may 6119 * be ENOTEMPTY). 6120 */ 6121 int 6122 vfs_emptydir(struct vnode *vp) 6123 { 6124 struct uio uio; 6125 struct iovec iov; 6126 struct dirent *dirent, *dp, *endp; 6127 int error, eof; 6128 6129 error = 0; 6130 eof = 0; 6131 6132 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 6133 6134 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 6135 iov.iov_base = dirent; 6136 iov.iov_len = sizeof(struct dirent); 6137 6138 uio.uio_iov = &iov; 6139 uio.uio_iovcnt = 1; 6140 uio.uio_offset = 0; 6141 uio.uio_resid = sizeof(struct dirent); 6142 uio.uio_segflg = UIO_SYSSPACE; 6143 uio.uio_rw = UIO_READ; 6144 uio.uio_td = curthread; 6145 6146 while (eof == 0 && error == 0) { 6147 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 6148 NULL, NULL); 6149 if (error != 0) 6150 break; 6151 endp = (void *)((uint8_t *)dirent + 6152 sizeof(struct dirent) - uio.uio_resid); 6153 for (dp = dirent; dp < endp; 6154 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 6155 if (dp->d_type == DT_WHT) 6156 continue; 6157 if (dp->d_namlen == 0) 6158 continue; 6159 if (dp->d_type != DT_DIR && 6160 dp->d_type != DT_UNKNOWN) { 6161 error = ENOTEMPTY; 6162 break; 6163 } 6164 if (dp->d_namlen > 2) { 6165 error = ENOTEMPTY; 6166 break; 6167 } 6168 if (dp->d_namlen == 1 && 6169 dp->d_name[0] != '.') { 6170 error = ENOTEMPTY; 6171 break; 6172 } 6173 if (dp->d_namlen == 2 && 6174 dp->d_name[1] != '.') { 6175 error = ENOTEMPTY; 6176 break; 6177 } 6178 uio.uio_resid = sizeof(struct dirent); 6179 } 6180 } 6181 free(dirent, M_TEMP); 6182 return (error); 6183 } 6184 6185 int 6186 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 6187 { 6188 int error; 6189 6190 if (dp->d_reclen > ap->a_uio->uio_resid) 6191 return (ENAMETOOLONG); 6192 error = uiomove(dp, dp->d_reclen, ap->a_uio); 6193 if (error) { 6194 if (ap->a_ncookies != NULL) { 6195 if (ap->a_cookies != NULL) 6196 free(ap->a_cookies, M_TEMP); 6197 ap->a_cookies = NULL; 6198 *ap->a_ncookies = 0; 6199 } 6200 return (error); 6201 } 6202 if (ap->a_ncookies == NULL) 6203 return (0); 6204 6205 KASSERT(ap->a_cookies, 6206 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 6207 6208 *ap->a_cookies = realloc(*ap->a_cookies, 6209 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 6210 (*ap->a_cookies)[*ap->a_ncookies] = off; 6211 *ap->a_ncookies += 1; 6212 return (0); 6213 } 6214 6215 /* 6216 * The purpose of this routine is to remove granularity from accmode_t, 6217 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 6218 * VADMIN and VAPPEND. 6219 * 6220 * If it returns 0, the caller is supposed to continue with the usual 6221 * access checks using 'accmode' as modified by this routine. If it 6222 * returns nonzero value, the caller is supposed to return that value 6223 * as errno. 6224 * 6225 * Note that after this routine runs, accmode may be zero. 6226 */ 6227 int 6228 vfs_unixify_accmode(accmode_t *accmode) 6229 { 6230 /* 6231 * There is no way to specify explicit "deny" rule using 6232 * file mode or POSIX.1e ACLs. 6233 */ 6234 if (*accmode & VEXPLICIT_DENY) { 6235 *accmode = 0; 6236 return (0); 6237 } 6238 6239 /* 6240 * None of these can be translated into usual access bits. 6241 * Also, the common case for NFSv4 ACLs is to not contain 6242 * either of these bits. Caller should check for VWRITE 6243 * on the containing directory instead. 6244 */ 6245 if (*accmode & (VDELETE_CHILD | VDELETE)) 6246 return (EPERM); 6247 6248 if (*accmode & VADMIN_PERMS) { 6249 *accmode &= ~VADMIN_PERMS; 6250 *accmode |= VADMIN; 6251 } 6252 6253 /* 6254 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6255 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6256 */ 6257 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6258 6259 return (0); 6260 } 6261 6262 /* 6263 * Clear out a doomed vnode (if any) and replace it with a new one as long 6264 * as the fs is not being unmounted. Return the root vnode to the caller. 6265 */ 6266 static int __noinline 6267 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6268 { 6269 struct vnode *vp; 6270 int error; 6271 6272 restart: 6273 if (mp->mnt_rootvnode != NULL) { 6274 MNT_ILOCK(mp); 6275 vp = mp->mnt_rootvnode; 6276 if (vp != NULL) { 6277 if (!VN_IS_DOOMED(vp)) { 6278 vrefact(vp); 6279 MNT_IUNLOCK(mp); 6280 error = vn_lock(vp, flags); 6281 if (error == 0) { 6282 *vpp = vp; 6283 return (0); 6284 } 6285 vrele(vp); 6286 goto restart; 6287 } 6288 /* 6289 * Clear the old one. 6290 */ 6291 mp->mnt_rootvnode = NULL; 6292 } 6293 MNT_IUNLOCK(mp); 6294 if (vp != NULL) { 6295 vfs_op_barrier_wait(mp); 6296 vrele(vp); 6297 } 6298 } 6299 error = VFS_CACHEDROOT(mp, flags, vpp); 6300 if (error != 0) 6301 return (error); 6302 if (mp->mnt_vfs_ops == 0) { 6303 MNT_ILOCK(mp); 6304 if (mp->mnt_vfs_ops != 0) { 6305 MNT_IUNLOCK(mp); 6306 return (0); 6307 } 6308 if (mp->mnt_rootvnode == NULL) { 6309 vrefact(*vpp); 6310 mp->mnt_rootvnode = *vpp; 6311 } else { 6312 if (mp->mnt_rootvnode != *vpp) { 6313 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6314 panic("%s: mismatch between vnode returned " 6315 " by VFS_CACHEDROOT and the one cached " 6316 " (%p != %p)", 6317 __func__, *vpp, mp->mnt_rootvnode); 6318 } 6319 } 6320 } 6321 MNT_IUNLOCK(mp); 6322 } 6323 return (0); 6324 } 6325 6326 int 6327 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6328 { 6329 struct vnode *vp; 6330 int error; 6331 6332 if (!vfs_op_thread_enter(mp)) 6333 return (vfs_cache_root_fallback(mp, flags, vpp)); 6334 vp = atomic_load_ptr(&mp->mnt_rootvnode); 6335 if (vp == NULL || VN_IS_DOOMED(vp)) { 6336 vfs_op_thread_exit(mp); 6337 return (vfs_cache_root_fallback(mp, flags, vpp)); 6338 } 6339 vrefact(vp); 6340 vfs_op_thread_exit(mp); 6341 error = vn_lock(vp, flags); 6342 if (error != 0) { 6343 vrele(vp); 6344 return (vfs_cache_root_fallback(mp, flags, vpp)); 6345 } 6346 *vpp = vp; 6347 return (0); 6348 } 6349 6350 struct vnode * 6351 vfs_cache_root_clear(struct mount *mp) 6352 { 6353 struct vnode *vp; 6354 6355 /* 6356 * ops > 0 guarantees there is nobody who can see this vnode 6357 */ 6358 MPASS(mp->mnt_vfs_ops > 0); 6359 vp = mp->mnt_rootvnode; 6360 if (vp != NULL) 6361 vn_seqc_write_begin(vp); 6362 mp->mnt_rootvnode = NULL; 6363 return (vp); 6364 } 6365 6366 void 6367 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6368 { 6369 6370 MPASS(mp->mnt_vfs_ops > 0); 6371 vrefact(vp); 6372 mp->mnt_rootvnode = vp; 6373 } 6374 6375 /* 6376 * These are helper functions for filesystems to traverse all 6377 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6378 * 6379 * This interface replaces MNT_VNODE_FOREACH. 6380 */ 6381 6382 struct vnode * 6383 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6384 { 6385 struct vnode *vp; 6386 6387 if (should_yield()) 6388 kern_yield(PRI_USER); 6389 MNT_ILOCK(mp); 6390 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6391 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6392 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6393 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6394 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6395 continue; 6396 VI_LOCK(vp); 6397 if (VN_IS_DOOMED(vp)) { 6398 VI_UNLOCK(vp); 6399 continue; 6400 } 6401 break; 6402 } 6403 if (vp == NULL) { 6404 __mnt_vnode_markerfree_all(mvp, mp); 6405 /* MNT_IUNLOCK(mp); -- done in above function */ 6406 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6407 return (NULL); 6408 } 6409 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6410 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6411 MNT_IUNLOCK(mp); 6412 return (vp); 6413 } 6414 6415 struct vnode * 6416 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6417 { 6418 struct vnode *vp; 6419 6420 *mvp = vn_alloc_marker(mp); 6421 MNT_ILOCK(mp); 6422 MNT_REF(mp); 6423 6424 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6425 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6426 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6427 continue; 6428 VI_LOCK(vp); 6429 if (VN_IS_DOOMED(vp)) { 6430 VI_UNLOCK(vp); 6431 continue; 6432 } 6433 break; 6434 } 6435 if (vp == NULL) { 6436 MNT_REL(mp); 6437 MNT_IUNLOCK(mp); 6438 vn_free_marker(*mvp); 6439 *mvp = NULL; 6440 return (NULL); 6441 } 6442 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6443 MNT_IUNLOCK(mp); 6444 return (vp); 6445 } 6446 6447 void 6448 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6449 { 6450 6451 if (*mvp == NULL) { 6452 MNT_IUNLOCK(mp); 6453 return; 6454 } 6455 6456 mtx_assert(MNT_MTX(mp), MA_OWNED); 6457 6458 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6459 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6460 MNT_REL(mp); 6461 MNT_IUNLOCK(mp); 6462 vn_free_marker(*mvp); 6463 *mvp = NULL; 6464 } 6465 6466 /* 6467 * These are helper functions for filesystems to traverse their 6468 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6469 */ 6470 static void 6471 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6472 { 6473 6474 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6475 6476 MNT_ILOCK(mp); 6477 MNT_REL(mp); 6478 MNT_IUNLOCK(mp); 6479 vn_free_marker(*mvp); 6480 *mvp = NULL; 6481 } 6482 6483 /* 6484 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6485 * conventional lock order during mnt_vnode_next_lazy iteration. 6486 * 6487 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6488 * The list lock is dropped and reacquired. On success, both locks are held. 6489 * On failure, the mount vnode list lock is held but the vnode interlock is 6490 * not, and the procedure may have yielded. 6491 */ 6492 static bool 6493 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6494 struct vnode *vp) 6495 { 6496 6497 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6498 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6499 ("%s: bad marker", __func__)); 6500 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6501 ("%s: inappropriate vnode", __func__)); 6502 ASSERT_VI_UNLOCKED(vp, __func__); 6503 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6504 6505 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6506 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6507 6508 /* 6509 * Note we may be racing against vdrop which transitioned the hold 6510 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine, 6511 * if we are the only user after we get the interlock we will just 6512 * vdrop. 6513 */ 6514 vhold(vp); 6515 mtx_unlock(&mp->mnt_listmtx); 6516 VI_LOCK(vp); 6517 if (VN_IS_DOOMED(vp)) { 6518 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6519 goto out_lost; 6520 } 6521 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6522 /* 6523 * There is nothing to do if we are the last user. 6524 */ 6525 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6526 goto out_lost; 6527 mtx_lock(&mp->mnt_listmtx); 6528 return (true); 6529 out_lost: 6530 vdropl(vp); 6531 maybe_yield(); 6532 mtx_lock(&mp->mnt_listmtx); 6533 return (false); 6534 } 6535 6536 static struct vnode * 6537 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6538 void *cbarg) 6539 { 6540 struct vnode *vp; 6541 6542 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6543 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6544 restart: 6545 vp = TAILQ_NEXT(*mvp, v_lazylist); 6546 while (vp != NULL) { 6547 if (vp->v_type == VMARKER) { 6548 vp = TAILQ_NEXT(vp, v_lazylist); 6549 continue; 6550 } 6551 /* 6552 * See if we want to process the vnode. Note we may encounter a 6553 * long string of vnodes we don't care about and hog the list 6554 * as a result. Check for it and requeue the marker. 6555 */ 6556 VNPASS(!VN_IS_DOOMED(vp), vp); 6557 if (!cb(vp, cbarg)) { 6558 if (!should_yield()) { 6559 vp = TAILQ_NEXT(vp, v_lazylist); 6560 continue; 6561 } 6562 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 6563 v_lazylist); 6564 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 6565 v_lazylist); 6566 mtx_unlock(&mp->mnt_listmtx); 6567 kern_yield(PRI_USER); 6568 mtx_lock(&mp->mnt_listmtx); 6569 goto restart; 6570 } 6571 /* 6572 * Try-lock because this is the wrong lock order. 6573 */ 6574 if (!VI_TRYLOCK(vp) && 6575 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 6576 goto restart; 6577 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 6578 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 6579 ("alien vnode on the lazy list %p %p", vp, mp)); 6580 VNPASS(vp->v_mount == mp, vp); 6581 VNPASS(!VN_IS_DOOMED(vp), vp); 6582 break; 6583 } 6584 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6585 6586 /* Check if we are done */ 6587 if (vp == NULL) { 6588 mtx_unlock(&mp->mnt_listmtx); 6589 mnt_vnode_markerfree_lazy(mvp, mp); 6590 return (NULL); 6591 } 6592 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 6593 mtx_unlock(&mp->mnt_listmtx); 6594 ASSERT_VI_LOCKED(vp, "lazy iter"); 6595 return (vp); 6596 } 6597 6598 struct vnode * 6599 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6600 void *cbarg) 6601 { 6602 6603 if (should_yield()) 6604 kern_yield(PRI_USER); 6605 mtx_lock(&mp->mnt_listmtx); 6606 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6607 } 6608 6609 struct vnode * 6610 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6611 void *cbarg) 6612 { 6613 struct vnode *vp; 6614 6615 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 6616 return (NULL); 6617 6618 *mvp = vn_alloc_marker(mp); 6619 MNT_ILOCK(mp); 6620 MNT_REF(mp); 6621 MNT_IUNLOCK(mp); 6622 6623 mtx_lock(&mp->mnt_listmtx); 6624 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 6625 if (vp == NULL) { 6626 mtx_unlock(&mp->mnt_listmtx); 6627 mnt_vnode_markerfree_lazy(mvp, mp); 6628 return (NULL); 6629 } 6630 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 6631 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6632 } 6633 6634 void 6635 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6636 { 6637 6638 if (*mvp == NULL) 6639 return; 6640 6641 mtx_lock(&mp->mnt_listmtx); 6642 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6643 mtx_unlock(&mp->mnt_listmtx); 6644 mnt_vnode_markerfree_lazy(mvp, mp); 6645 } 6646 6647 int 6648 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 6649 { 6650 6651 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 6652 cnp->cn_flags &= ~NOEXECCHECK; 6653 return (0); 6654 } 6655 6656 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread)); 6657 } 6658 6659 /* 6660 * Do not use this variant unless you have means other than the hold count 6661 * to prevent the vnode from getting freed. 6662 */ 6663 void 6664 vn_seqc_write_begin_unheld_locked(struct vnode *vp) 6665 { 6666 6667 ASSERT_VI_LOCKED(vp, __func__); 6668 VNPASS(vp->v_seqc_users >= 0, vp); 6669 vp->v_seqc_users++; 6670 if (vp->v_seqc_users == 1) 6671 seqc_sleepable_write_begin(&vp->v_seqc); 6672 } 6673 6674 void 6675 vn_seqc_write_begin_locked(struct vnode *vp) 6676 { 6677 6678 ASSERT_VI_LOCKED(vp, __func__); 6679 VNPASS(vp->v_holdcnt > 0, vp); 6680 vn_seqc_write_begin_unheld_locked(vp); 6681 } 6682 6683 void 6684 vn_seqc_write_begin(struct vnode *vp) 6685 { 6686 6687 VI_LOCK(vp); 6688 vn_seqc_write_begin_locked(vp); 6689 VI_UNLOCK(vp); 6690 } 6691 6692 void 6693 vn_seqc_write_begin_unheld(struct vnode *vp) 6694 { 6695 6696 VI_LOCK(vp); 6697 vn_seqc_write_begin_unheld_locked(vp); 6698 VI_UNLOCK(vp); 6699 } 6700 6701 void 6702 vn_seqc_write_end_locked(struct vnode *vp) 6703 { 6704 6705 ASSERT_VI_LOCKED(vp, __func__); 6706 VNPASS(vp->v_seqc_users > 0, vp); 6707 vp->v_seqc_users--; 6708 if (vp->v_seqc_users == 0) 6709 seqc_sleepable_write_end(&vp->v_seqc); 6710 } 6711 6712 void 6713 vn_seqc_write_end(struct vnode *vp) 6714 { 6715 6716 VI_LOCK(vp); 6717 vn_seqc_write_end_locked(vp); 6718 VI_UNLOCK(vp); 6719 } 6720