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 bool vhold_recycle_free(struct vnode *); 113 static void vfs_knllock(void *arg); 114 static void vfs_knlunlock(void *arg); 115 static void vfs_knl_assert_locked(void *arg); 116 static void vfs_knl_assert_unlocked(void *arg); 117 static void destroy_vpollinfo(struct vpollinfo *vi); 118 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 119 daddr_t startlbn, daddr_t endlbn); 120 static void vnlru_recalc(void); 121 122 /* 123 * These fences are intended for cases where some synchronization is 124 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 125 * and v_usecount) updates. Access to v_iflags is generally synchronized 126 * by the interlock, but we have some internal assertions that check vnode 127 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 128 * for now. 129 */ 130 #ifdef INVARIANTS 131 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 132 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 133 #else 134 #define VNODE_REFCOUNT_FENCE_ACQ() 135 #define VNODE_REFCOUNT_FENCE_REL() 136 #endif 137 138 /* 139 * Number of vnodes in existence. Increased whenever getnewvnode() 140 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode. 141 */ 142 static u_long __exclusive_cache_line numvnodes; 143 144 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 145 "Number of vnodes in existence"); 146 147 static counter_u64_t vnodes_created; 148 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 149 "Number of vnodes created by getnewvnode"); 150 151 /* 152 * Conversion tables for conversion from vnode types to inode formats 153 * and back. 154 */ 155 enum vtype iftovt_tab[16] = { 156 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 157 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 158 }; 159 int vttoif_tab[10] = { 160 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 161 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 162 }; 163 164 /* 165 * List of allocates vnodes in the system. 166 */ 167 static TAILQ_HEAD(freelst, vnode) vnode_list; 168 static struct vnode *vnode_list_free_marker; 169 static struct vnode *vnode_list_reclaim_marker; 170 171 /* 172 * "Free" vnode target. Free vnodes are rarely completely free, but are 173 * just ones that are cheap to recycle. Usually they are for files which 174 * have been stat'd but not read; these usually have inode and namecache 175 * data attached to them. This target is the preferred minimum size of a 176 * sub-cache consisting mostly of such files. The system balances the size 177 * of this sub-cache with its complement to try to prevent either from 178 * thrashing while the other is relatively inactive. The targets express 179 * a preference for the best balance. 180 * 181 * "Above" this target there are 2 further targets (watermarks) related 182 * to recyling of free vnodes. In the best-operating case, the cache is 183 * exactly full, the free list has size between vlowat and vhiwat above the 184 * free target, and recycling from it and normal use maintains this state. 185 * Sometimes the free list is below vlowat or even empty, but this state 186 * is even better for immediate use provided the cache is not full. 187 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 188 * ones) to reach one of these states. The watermarks are currently hard- 189 * coded as 4% and 9% of the available space higher. These and the default 190 * of 25% for wantfreevnodes are too large if the memory size is large. 191 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 192 * whenever vnlru_proc() becomes active. 193 */ 194 static long wantfreevnodes; 195 static long __exclusive_cache_line freevnodes; 196 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 197 &freevnodes, 0, "Number of \"free\" vnodes"); 198 static long freevnodes_old; 199 200 static counter_u64_t recycles_count; 201 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 202 "Number of vnodes recycled to meet vnode cache targets"); 203 204 static counter_u64_t recycles_free_count; 205 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD, &recycles_free_count, 206 "Number of free vnodes recycled to meet vnode cache targets"); 207 208 static counter_u64_t deferred_inact; 209 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD, &deferred_inact, 210 "Number of times inactive processing was deferred"); 211 212 /* To keep more than one thread at a time from running vfs_getnewfsid */ 213 static struct mtx mntid_mtx; 214 215 /* 216 * Lock for any access to the following: 217 * vnode_list 218 * numvnodes 219 * freevnodes 220 */ 221 static struct mtx __exclusive_cache_line vnode_list_mtx; 222 223 /* Publicly exported FS */ 224 struct nfs_public nfs_pub; 225 226 static uma_zone_t buf_trie_zone; 227 static smr_t buf_trie_smr; 228 229 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 230 static uma_zone_t vnode_zone; 231 MALLOC_DEFINE(M_VNODEPOLL, "VN POLL", "vnode poll"); 232 233 __read_frequently smr_t vfs_smr; 234 235 /* 236 * The workitem queue. 237 * 238 * It is useful to delay writes of file data and filesystem metadata 239 * for tens of seconds so that quickly created and deleted files need 240 * not waste disk bandwidth being created and removed. To realize this, 241 * we append vnodes to a "workitem" queue. When running with a soft 242 * updates implementation, most pending metadata dependencies should 243 * not wait for more than a few seconds. Thus, mounted on block devices 244 * are delayed only about a half the time that file data is delayed. 245 * Similarly, directory updates are more critical, so are only delayed 246 * about a third the time that file data is delayed. Thus, there are 247 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 248 * one each second (driven off the filesystem syncer process). The 249 * syncer_delayno variable indicates the next queue that is to be processed. 250 * Items that need to be processed soon are placed in this queue: 251 * 252 * syncer_workitem_pending[syncer_delayno] 253 * 254 * A delay of fifteen seconds is done by placing the request fifteen 255 * entries later in the queue: 256 * 257 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 258 * 259 */ 260 static int syncer_delayno; 261 static long syncer_mask; 262 LIST_HEAD(synclist, bufobj); 263 static struct synclist *syncer_workitem_pending; 264 /* 265 * The sync_mtx protects: 266 * bo->bo_synclist 267 * sync_vnode_count 268 * syncer_delayno 269 * syncer_state 270 * syncer_workitem_pending 271 * syncer_worklist_len 272 * rushjob 273 */ 274 static struct mtx sync_mtx; 275 static struct cv sync_wakeup; 276 277 #define SYNCER_MAXDELAY 32 278 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 279 static int syncdelay = 30; /* max time to delay syncing data */ 280 static int filedelay = 30; /* time to delay syncing files */ 281 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 282 "Time to delay syncing files (in seconds)"); 283 static int dirdelay = 29; /* time to delay syncing directories */ 284 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 285 "Time to delay syncing directories (in seconds)"); 286 static int metadelay = 28; /* time to delay syncing metadata */ 287 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 288 "Time to delay syncing metadata (in seconds)"); 289 static int rushjob; /* number of slots to run ASAP */ 290 static int stat_rush_requests; /* number of times I/O speeded up */ 291 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 292 "Number of times I/O speeded up (rush requests)"); 293 294 #define VDBATCH_SIZE 8 295 struct vdbatch { 296 u_int index; 297 long freevnodes; 298 struct mtx lock; 299 struct vnode *tab[VDBATCH_SIZE]; 300 }; 301 DPCPU_DEFINE_STATIC(struct vdbatch, vd); 302 303 static void vdbatch_dequeue(struct vnode *vp); 304 305 /* 306 * When shutting down the syncer, run it at four times normal speed. 307 */ 308 #define SYNCER_SHUTDOWN_SPEEDUP 4 309 static int sync_vnode_count; 310 static int syncer_worklist_len; 311 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 312 syncer_state; 313 314 /* Target for maximum number of vnodes. */ 315 u_long desiredvnodes; 316 static u_long gapvnodes; /* gap between wanted and desired */ 317 static u_long vhiwat; /* enough extras after expansion */ 318 static u_long vlowat; /* minimal extras before expansion */ 319 static u_long vstir; /* nonzero to stir non-free vnodes */ 320 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 321 322 static u_long vnlru_read_freevnodes(void); 323 324 /* 325 * Note that no attempt is made to sanitize these parameters. 326 */ 327 static int 328 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS) 329 { 330 u_long val; 331 int error; 332 333 val = desiredvnodes; 334 error = sysctl_handle_long(oidp, &val, 0, req); 335 if (error != 0 || req->newptr == NULL) 336 return (error); 337 338 if (val == desiredvnodes) 339 return (0); 340 mtx_lock(&vnode_list_mtx); 341 desiredvnodes = val; 342 wantfreevnodes = desiredvnodes / 4; 343 vnlru_recalc(); 344 mtx_unlock(&vnode_list_mtx); 345 /* 346 * XXX There is no protection against multiple threads changing 347 * desiredvnodes at the same time. Locking above only helps vnlru and 348 * getnewvnode. 349 */ 350 vfs_hash_changesize(desiredvnodes); 351 cache_changesize(desiredvnodes); 352 return (0); 353 } 354 355 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 356 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes, 357 "LU", "Target for maximum number of vnodes"); 358 359 static int 360 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS) 361 { 362 u_long val; 363 int error; 364 365 val = wantfreevnodes; 366 error = sysctl_handle_long(oidp, &val, 0, req); 367 if (error != 0 || req->newptr == NULL) 368 return (error); 369 370 if (val == wantfreevnodes) 371 return (0); 372 mtx_lock(&vnode_list_mtx); 373 wantfreevnodes = val; 374 vnlru_recalc(); 375 mtx_unlock(&vnode_list_mtx); 376 return (0); 377 } 378 379 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes, 380 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes, 381 "LU", "Target for minimum number of \"free\" vnodes"); 382 383 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 384 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 385 static int vnlru_nowhere; 386 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 387 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 388 389 static int 390 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 391 { 392 struct vnode *vp; 393 struct nameidata nd; 394 char *buf; 395 unsigned long ndflags; 396 int error; 397 398 if (req->newptr == NULL) 399 return (EINVAL); 400 if (req->newlen >= PATH_MAX) 401 return (E2BIG); 402 403 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK); 404 error = SYSCTL_IN(req, buf, req->newlen); 405 if (error != 0) 406 goto out; 407 408 buf[req->newlen] = '\0'; 409 410 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | SAVENAME; 411 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); 412 if ((error = namei(&nd)) != 0) 413 goto out; 414 vp = nd.ni_vp; 415 416 if (VN_IS_DOOMED(vp)) { 417 /* 418 * This vnode is being recycled. Return != 0 to let the caller 419 * know that the sysctl had no effect. Return EAGAIN because a 420 * subsequent call will likely succeed (since namei will create 421 * a new vnode if necessary) 422 */ 423 error = EAGAIN; 424 goto putvnode; 425 } 426 427 counter_u64_add(recycles_count, 1); 428 vgone(vp); 429 putvnode: 430 NDFREE(&nd, 0); 431 out: 432 free(buf, M_TEMP); 433 return (error); 434 } 435 436 static int 437 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 438 { 439 struct thread *td = curthread; 440 struct vnode *vp; 441 struct file *fp; 442 int error; 443 int fd; 444 445 if (req->newptr == NULL) 446 return (EBADF); 447 448 error = sysctl_handle_int(oidp, &fd, 0, req); 449 if (error != 0) 450 return (error); 451 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 452 if (error != 0) 453 return (error); 454 vp = fp->f_vnode; 455 456 error = vn_lock(vp, LK_EXCLUSIVE); 457 if (error != 0) 458 goto drop; 459 460 counter_u64_add(recycles_count, 1); 461 vgone(vp); 462 VOP_UNLOCK(vp); 463 drop: 464 fdrop(fp, td); 465 return (error); 466 } 467 468 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 469 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 470 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 471 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 472 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 473 sysctl_ftry_reclaim_vnode, "I", 474 "Try to reclaim a vnode by its file descriptor"); 475 476 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 477 static int vnsz2log; 478 479 /* 480 * Support for the bufobj clean & dirty pctrie. 481 */ 482 static void * 483 buf_trie_alloc(struct pctrie *ptree) 484 { 485 return (uma_zalloc_smr(buf_trie_zone, M_NOWAIT)); 486 } 487 488 static void 489 buf_trie_free(struct pctrie *ptree, void *node) 490 { 491 uma_zfree_smr(buf_trie_zone, node); 492 } 493 PCTRIE_DEFINE_SMR(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free, 494 buf_trie_smr); 495 496 /* 497 * Initialize the vnode management data structures. 498 * 499 * Reevaluate the following cap on the number of vnodes after the physical 500 * memory size exceeds 512GB. In the limit, as the physical memory size 501 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 502 */ 503 #ifndef MAXVNODES_MAX 504 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */ 505 #endif 506 507 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 508 509 static struct vnode * 510 vn_alloc_marker(struct mount *mp) 511 { 512 struct vnode *vp; 513 514 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 515 vp->v_type = VMARKER; 516 vp->v_mount = mp; 517 518 return (vp); 519 } 520 521 static void 522 vn_free_marker(struct vnode *vp) 523 { 524 525 MPASS(vp->v_type == VMARKER); 526 free(vp, M_VNODE_MARKER); 527 } 528 529 /* 530 * Initialize a vnode as it first enters the zone. 531 */ 532 static int 533 vnode_init(void *mem, int size, int flags) 534 { 535 struct vnode *vp; 536 537 vp = mem; 538 bzero(vp, size); 539 /* 540 * Setup locks. 541 */ 542 vp->v_vnlock = &vp->v_lock; 543 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 544 /* 545 * By default, don't allow shared locks unless filesystems opt-in. 546 */ 547 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 548 LK_NOSHARE | LK_IS_VNODE); 549 /* 550 * Initialize bufobj. 551 */ 552 bufobj_init(&vp->v_bufobj, vp); 553 /* 554 * Initialize namecache. 555 */ 556 cache_vnode_init(vp); 557 /* 558 * Initialize rangelocks. 559 */ 560 rangelock_init(&vp->v_rl); 561 562 vp->v_dbatchcpu = NOCPU; 563 564 /* 565 * Check vhold_recycle_free for an explanation. 566 */ 567 vp->v_holdcnt = VHOLD_NO_SMR; 568 vp->v_type = VNON; 569 mtx_lock(&vnode_list_mtx); 570 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist); 571 mtx_unlock(&vnode_list_mtx); 572 return (0); 573 } 574 575 /* 576 * Free a vnode when it is cleared from the zone. 577 */ 578 static void 579 vnode_fini(void *mem, int size) 580 { 581 struct vnode *vp; 582 struct bufobj *bo; 583 584 vp = mem; 585 vdbatch_dequeue(vp); 586 mtx_lock(&vnode_list_mtx); 587 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 588 mtx_unlock(&vnode_list_mtx); 589 rangelock_destroy(&vp->v_rl); 590 lockdestroy(vp->v_vnlock); 591 mtx_destroy(&vp->v_interlock); 592 bo = &vp->v_bufobj; 593 rw_destroy(BO_LOCKPTR(bo)); 594 } 595 596 /* 597 * Provide the size of NFS nclnode and NFS fh for calculation of the 598 * vnode memory consumption. The size is specified directly to 599 * eliminate dependency on NFS-private header. 600 * 601 * Other filesystems may use bigger or smaller (like UFS and ZFS) 602 * private inode data, but the NFS-based estimation is ample enough. 603 * Still, we care about differences in the size between 64- and 32-bit 604 * platforms. 605 * 606 * Namecache structure size is heuristically 607 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 608 */ 609 #ifdef _LP64 610 #define NFS_NCLNODE_SZ (528 + 64) 611 #define NC_SZ 148 612 #else 613 #define NFS_NCLNODE_SZ (360 + 32) 614 #define NC_SZ 92 615 #endif 616 617 static void 618 vntblinit(void *dummy __unused) 619 { 620 struct vdbatch *vd; 621 int cpu, physvnodes, virtvnodes; 622 u_int i; 623 624 /* 625 * Desiredvnodes is a function of the physical memory size and the 626 * kernel's heap size. Generally speaking, it scales with the 627 * physical memory size. The ratio of desiredvnodes to the physical 628 * memory size is 1:16 until desiredvnodes exceeds 98,304. 629 * Thereafter, the 630 * marginal ratio of desiredvnodes to the physical memory size is 631 * 1:64. However, desiredvnodes is limited by the kernel's heap 632 * size. The memory required by desiredvnodes vnodes and vm objects 633 * must not exceed 1/10th of the kernel's heap size. 634 */ 635 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 636 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 637 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 638 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 639 desiredvnodes = min(physvnodes, virtvnodes); 640 if (desiredvnodes > MAXVNODES_MAX) { 641 if (bootverbose) 642 printf("Reducing kern.maxvnodes %lu -> %lu\n", 643 desiredvnodes, MAXVNODES_MAX); 644 desiredvnodes = MAXVNODES_MAX; 645 } 646 wantfreevnodes = desiredvnodes / 4; 647 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 648 TAILQ_INIT(&vnode_list); 649 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF); 650 /* 651 * The lock is taken to appease WITNESS. 652 */ 653 mtx_lock(&vnode_list_mtx); 654 vnlru_recalc(); 655 mtx_unlock(&vnode_list_mtx); 656 vnode_list_free_marker = vn_alloc_marker(NULL); 657 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist); 658 vnode_list_reclaim_marker = vn_alloc_marker(NULL); 659 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist); 660 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 661 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 662 uma_zone_set_smr(vnode_zone, vfs_smr); 663 /* 664 * Preallocate enough nodes to support one-per buf so that 665 * we can not fail an insert. reassignbuf() callers can not 666 * tolerate the insertion failure. 667 */ 668 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 669 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 670 UMA_ZONE_NOFREE | UMA_ZONE_SMR); 671 buf_trie_smr = uma_zone_get_smr(buf_trie_zone); 672 uma_prealloc(buf_trie_zone, nbuf); 673 674 vnodes_created = counter_u64_alloc(M_WAITOK); 675 recycles_count = counter_u64_alloc(M_WAITOK); 676 recycles_free_count = counter_u64_alloc(M_WAITOK); 677 deferred_inact = counter_u64_alloc(M_WAITOK); 678 679 /* 680 * Initialize the filesystem syncer. 681 */ 682 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 683 &syncer_mask); 684 syncer_maxdelay = syncer_mask + 1; 685 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 686 cv_init(&sync_wakeup, "syncer"); 687 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 688 vnsz2log++; 689 vnsz2log--; 690 691 CPU_FOREACH(cpu) { 692 vd = DPCPU_ID_PTR((cpu), vd); 693 bzero(vd, sizeof(*vd)); 694 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF); 695 } 696 } 697 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 698 699 /* 700 * Mark a mount point as busy. Used to synchronize access and to delay 701 * unmounting. Eventually, mountlist_mtx is not released on failure. 702 * 703 * vfs_busy() is a custom lock, it can block the caller. 704 * vfs_busy() only sleeps if the unmount is active on the mount point. 705 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 706 * vnode belonging to mp. 707 * 708 * Lookup uses vfs_busy() to traverse mount points. 709 * root fs var fs 710 * / vnode lock A / vnode lock (/var) D 711 * /var vnode lock B /log vnode lock(/var/log) E 712 * vfs_busy lock C vfs_busy lock F 713 * 714 * Within each file system, the lock order is C->A->B and F->D->E. 715 * 716 * When traversing across mounts, the system follows that lock order: 717 * 718 * C->A->B 719 * | 720 * +->F->D->E 721 * 722 * The lookup() process for namei("/var") illustrates the process: 723 * VOP_LOOKUP() obtains B while A is held 724 * vfs_busy() obtains a shared lock on F while A and B are held 725 * vput() releases lock on B 726 * vput() releases lock on A 727 * VFS_ROOT() obtains lock on D while shared lock on F is held 728 * vfs_unbusy() releases shared lock on F 729 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 730 * Attempt to lock A (instead of vp_crossmp) while D is held would 731 * violate the global order, causing deadlocks. 732 * 733 * dounmount() locks B while F is drained. 734 */ 735 int 736 vfs_busy(struct mount *mp, int flags) 737 { 738 739 MPASS((flags & ~MBF_MASK) == 0); 740 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 741 742 if (vfs_op_thread_enter(mp)) { 743 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 744 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0); 745 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0); 746 vfs_mp_count_add_pcpu(mp, ref, 1); 747 vfs_mp_count_add_pcpu(mp, lockref, 1); 748 vfs_op_thread_exit(mp); 749 if (flags & MBF_MNTLSTLOCK) 750 mtx_unlock(&mountlist_mtx); 751 return (0); 752 } 753 754 MNT_ILOCK(mp); 755 vfs_assert_mount_counters(mp); 756 MNT_REF(mp); 757 /* 758 * If mount point is currently being unmounted, sleep until the 759 * mount point fate is decided. If thread doing the unmounting fails, 760 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 761 * that this mount point has survived the unmount attempt and vfs_busy 762 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 763 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 764 * about to be really destroyed. vfs_busy needs to release its 765 * reference on the mount point in this case and return with ENOENT, 766 * telling the caller that mount mount it tried to busy is no longer 767 * valid. 768 */ 769 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 770 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 771 MNT_REL(mp); 772 MNT_IUNLOCK(mp); 773 CTR1(KTR_VFS, "%s: failed busying before sleeping", 774 __func__); 775 return (ENOENT); 776 } 777 if (flags & MBF_MNTLSTLOCK) 778 mtx_unlock(&mountlist_mtx); 779 mp->mnt_kern_flag |= MNTK_MWAIT; 780 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 781 if (flags & MBF_MNTLSTLOCK) 782 mtx_lock(&mountlist_mtx); 783 MNT_ILOCK(mp); 784 } 785 if (flags & MBF_MNTLSTLOCK) 786 mtx_unlock(&mountlist_mtx); 787 mp->mnt_lockref++; 788 MNT_IUNLOCK(mp); 789 return (0); 790 } 791 792 /* 793 * Free a busy filesystem. 794 */ 795 void 796 vfs_unbusy(struct mount *mp) 797 { 798 int c; 799 800 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 801 802 if (vfs_op_thread_enter(mp)) { 803 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 804 vfs_mp_count_sub_pcpu(mp, lockref, 1); 805 vfs_mp_count_sub_pcpu(mp, ref, 1); 806 vfs_op_thread_exit(mp); 807 return; 808 } 809 810 MNT_ILOCK(mp); 811 vfs_assert_mount_counters(mp); 812 MNT_REL(mp); 813 c = --mp->mnt_lockref; 814 if (mp->mnt_vfs_ops == 0) { 815 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 816 MNT_IUNLOCK(mp); 817 return; 818 } 819 if (c < 0) 820 vfs_dump_mount_counters(mp); 821 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 822 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 823 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 824 mp->mnt_kern_flag &= ~MNTK_DRAINING; 825 wakeup(&mp->mnt_lockref); 826 } 827 MNT_IUNLOCK(mp); 828 } 829 830 /* 831 * Lookup a mount point by filesystem identifier. 832 */ 833 struct mount * 834 vfs_getvfs(fsid_t *fsid) 835 { 836 struct mount *mp; 837 838 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 839 mtx_lock(&mountlist_mtx); 840 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 841 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 842 vfs_ref(mp); 843 mtx_unlock(&mountlist_mtx); 844 return (mp); 845 } 846 } 847 mtx_unlock(&mountlist_mtx); 848 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 849 return ((struct mount *) 0); 850 } 851 852 /* 853 * Lookup a mount point by filesystem identifier, busying it before 854 * returning. 855 * 856 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 857 * cache for popular filesystem identifiers. The cache is lockess, using 858 * the fact that struct mount's are never freed. In worst case we may 859 * get pointer to unmounted or even different filesystem, so we have to 860 * check what we got, and go slow way if so. 861 */ 862 struct mount * 863 vfs_busyfs(fsid_t *fsid) 864 { 865 #define FSID_CACHE_SIZE 256 866 typedef struct mount * volatile vmp_t; 867 static vmp_t cache[FSID_CACHE_SIZE]; 868 struct mount *mp; 869 int error; 870 uint32_t hash; 871 872 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 873 hash = fsid->val[0] ^ fsid->val[1]; 874 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 875 mp = cache[hash]; 876 if (mp == NULL || fsidcmp(&mp->mnt_stat.f_fsid, fsid) != 0) 877 goto slow; 878 if (vfs_busy(mp, 0) != 0) { 879 cache[hash] = NULL; 880 goto slow; 881 } 882 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) 883 return (mp); 884 else 885 vfs_unbusy(mp); 886 887 slow: 888 mtx_lock(&mountlist_mtx); 889 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 890 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 891 error = vfs_busy(mp, MBF_MNTLSTLOCK); 892 if (error) { 893 cache[hash] = NULL; 894 mtx_unlock(&mountlist_mtx); 895 return (NULL); 896 } 897 cache[hash] = mp; 898 return (mp); 899 } 900 } 901 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 902 mtx_unlock(&mountlist_mtx); 903 return ((struct mount *) 0); 904 } 905 906 /* 907 * Check if a user can access privileged mount options. 908 */ 909 int 910 vfs_suser(struct mount *mp, struct thread *td) 911 { 912 int error; 913 914 if (jailed(td->td_ucred)) { 915 /* 916 * If the jail of the calling thread lacks permission for 917 * this type of file system, deny immediately. 918 */ 919 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 920 return (EPERM); 921 922 /* 923 * If the file system was mounted outside the jail of the 924 * calling thread, deny immediately. 925 */ 926 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 927 return (EPERM); 928 } 929 930 /* 931 * If file system supports delegated administration, we don't check 932 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 933 * by the file system itself. 934 * If this is not the user that did original mount, we check for 935 * the PRIV_VFS_MOUNT_OWNER privilege. 936 */ 937 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 938 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 939 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 940 return (error); 941 } 942 return (0); 943 } 944 945 /* 946 * Get a new unique fsid. Try to make its val[0] unique, since this value 947 * will be used to create fake device numbers for stat(). Also try (but 948 * not so hard) make its val[0] unique mod 2^16, since some emulators only 949 * support 16-bit device numbers. We end up with unique val[0]'s for the 950 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 951 * 952 * Keep in mind that several mounts may be running in parallel. Starting 953 * the search one past where the previous search terminated is both a 954 * micro-optimization and a defense against returning the same fsid to 955 * different mounts. 956 */ 957 void 958 vfs_getnewfsid(struct mount *mp) 959 { 960 static uint16_t mntid_base; 961 struct mount *nmp; 962 fsid_t tfsid; 963 int mtype; 964 965 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 966 mtx_lock(&mntid_mtx); 967 mtype = mp->mnt_vfc->vfc_typenum; 968 tfsid.val[1] = mtype; 969 mtype = (mtype & 0xFF) << 24; 970 for (;;) { 971 tfsid.val[0] = makedev(255, 972 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 973 mntid_base++; 974 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 975 break; 976 vfs_rel(nmp); 977 } 978 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 979 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 980 mtx_unlock(&mntid_mtx); 981 } 982 983 /* 984 * Knob to control the precision of file timestamps: 985 * 986 * 0 = seconds only; nanoseconds zeroed. 987 * 1 = seconds and nanoseconds, accurate within 1/HZ. 988 * 2 = seconds and nanoseconds, truncated to microseconds. 989 * >=3 = seconds and nanoseconds, maximum precision. 990 */ 991 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 992 993 static int timestamp_precision = TSP_USEC; 994 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 995 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 996 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 997 "3+: sec + ns (max. precision))"); 998 999 /* 1000 * Get a current timestamp. 1001 */ 1002 void 1003 vfs_timestamp(struct timespec *tsp) 1004 { 1005 struct timeval tv; 1006 1007 switch (timestamp_precision) { 1008 case TSP_SEC: 1009 tsp->tv_sec = time_second; 1010 tsp->tv_nsec = 0; 1011 break; 1012 case TSP_HZ: 1013 getnanotime(tsp); 1014 break; 1015 case TSP_USEC: 1016 microtime(&tv); 1017 TIMEVAL_TO_TIMESPEC(&tv, tsp); 1018 break; 1019 case TSP_NSEC: 1020 default: 1021 nanotime(tsp); 1022 break; 1023 } 1024 } 1025 1026 /* 1027 * Set vnode attributes to VNOVAL 1028 */ 1029 void 1030 vattr_null(struct vattr *vap) 1031 { 1032 1033 vap->va_type = VNON; 1034 vap->va_size = VNOVAL; 1035 vap->va_bytes = VNOVAL; 1036 vap->va_mode = VNOVAL; 1037 vap->va_nlink = VNOVAL; 1038 vap->va_uid = VNOVAL; 1039 vap->va_gid = VNOVAL; 1040 vap->va_fsid = VNOVAL; 1041 vap->va_fileid = VNOVAL; 1042 vap->va_blocksize = VNOVAL; 1043 vap->va_rdev = VNOVAL; 1044 vap->va_atime.tv_sec = VNOVAL; 1045 vap->va_atime.tv_nsec = VNOVAL; 1046 vap->va_mtime.tv_sec = VNOVAL; 1047 vap->va_mtime.tv_nsec = VNOVAL; 1048 vap->va_ctime.tv_sec = VNOVAL; 1049 vap->va_ctime.tv_nsec = VNOVAL; 1050 vap->va_birthtime.tv_sec = VNOVAL; 1051 vap->va_birthtime.tv_nsec = VNOVAL; 1052 vap->va_flags = VNOVAL; 1053 vap->va_gen = VNOVAL; 1054 vap->va_vaflags = 0; 1055 } 1056 1057 /* 1058 * Try to reduce the total number of vnodes. 1059 * 1060 * This routine (and its user) are buggy in at least the following ways: 1061 * - all parameters were picked years ago when RAM sizes were significantly 1062 * smaller 1063 * - it can pick vnodes based on pages used by the vm object, but filesystems 1064 * like ZFS don't use it making the pick broken 1065 * - since ZFS has its own aging policy it gets partially combated by this one 1066 * - a dedicated method should be provided for filesystems to let them decide 1067 * whether the vnode should be recycled 1068 * 1069 * This routine is called when we have too many vnodes. It attempts 1070 * to free <count> vnodes and will potentially free vnodes that still 1071 * have VM backing store (VM backing store is typically the cause 1072 * of a vnode blowout so we want to do this). Therefore, this operation 1073 * is not considered cheap. 1074 * 1075 * A number of conditions may prevent a vnode from being reclaimed. 1076 * the buffer cache may have references on the vnode, a directory 1077 * vnode may still have references due to the namei cache representing 1078 * underlying files, or the vnode may be in active use. It is not 1079 * desirable to reuse such vnodes. These conditions may cause the 1080 * number of vnodes to reach some minimum value regardless of what 1081 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 1082 * 1083 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 1084 * entries if this argument is strue 1085 * @param trigger Only reclaim vnodes with fewer than this many resident 1086 * pages. 1087 * @param target How many vnodes to reclaim. 1088 * @return The number of vnodes that were reclaimed. 1089 */ 1090 static int 1091 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target) 1092 { 1093 struct vnode *vp, *mvp; 1094 struct mount *mp; 1095 struct vm_object *object; 1096 u_long done; 1097 bool retried; 1098 1099 mtx_assert(&vnode_list_mtx, MA_OWNED); 1100 1101 retried = false; 1102 done = 0; 1103 1104 mvp = vnode_list_reclaim_marker; 1105 restart: 1106 vp = mvp; 1107 while (done < target) { 1108 vp = TAILQ_NEXT(vp, v_vnodelist); 1109 if (__predict_false(vp == NULL)) 1110 break; 1111 1112 if (__predict_false(vp->v_type == VMARKER)) 1113 continue; 1114 1115 /* 1116 * If it's been deconstructed already, it's still 1117 * referenced, or it exceeds the trigger, skip it. 1118 * Also skip free vnodes. We are trying to make space 1119 * to expand the free list, not reduce it. 1120 */ 1121 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1122 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src))) 1123 goto next_iter; 1124 1125 if (vp->v_type == VBAD || vp->v_type == VNON) 1126 goto next_iter; 1127 1128 object = atomic_load_ptr(&vp->v_object); 1129 if (object == NULL || object->resident_page_count > trigger) { 1130 goto next_iter; 1131 } 1132 1133 /* 1134 * Handle races against vnode allocation. Filesystems lock the 1135 * vnode some time after it gets returned from getnewvnode, 1136 * despite type and hold count being manipulated earlier. 1137 * Resorting to checking v_mount restores guarantees present 1138 * before the global list was reworked to contain all vnodes. 1139 */ 1140 if (!VI_TRYLOCK(vp)) 1141 goto next_iter; 1142 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1143 VI_UNLOCK(vp); 1144 goto next_iter; 1145 } 1146 if (vp->v_mount == NULL) { 1147 VI_UNLOCK(vp); 1148 goto next_iter; 1149 } 1150 vholdl(vp); 1151 VI_UNLOCK(vp); 1152 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1153 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1154 mtx_unlock(&vnode_list_mtx); 1155 1156 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1157 vdrop(vp); 1158 goto next_iter_unlocked; 1159 } 1160 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { 1161 vdrop(vp); 1162 vn_finished_write(mp); 1163 goto next_iter_unlocked; 1164 } 1165 1166 VI_LOCK(vp); 1167 if (vp->v_usecount > 0 || 1168 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1169 (vp->v_object != NULL && 1170 vp->v_object->resident_page_count > trigger)) { 1171 VOP_UNLOCK(vp); 1172 vdropl(vp); 1173 vn_finished_write(mp); 1174 goto next_iter_unlocked; 1175 } 1176 counter_u64_add(recycles_count, 1); 1177 vgonel(vp); 1178 VOP_UNLOCK(vp); 1179 vdropl(vp); 1180 vn_finished_write(mp); 1181 done++; 1182 next_iter_unlocked: 1183 if (should_yield()) 1184 kern_yield(PRI_USER); 1185 mtx_lock(&vnode_list_mtx); 1186 goto restart; 1187 next_iter: 1188 MPASS(vp->v_type != VMARKER); 1189 if (!should_yield()) 1190 continue; 1191 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1192 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1193 mtx_unlock(&vnode_list_mtx); 1194 kern_yield(PRI_USER); 1195 mtx_lock(&vnode_list_mtx); 1196 goto restart; 1197 } 1198 if (done == 0 && !retried) { 1199 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1200 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1201 retried = true; 1202 goto restart; 1203 } 1204 return (done); 1205 } 1206 1207 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1208 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1209 0, 1210 "limit on vnode free requests per call to the vnlru_free routine"); 1211 1212 /* 1213 * Attempt to reduce the free list by the requested amount. 1214 */ 1215 static int 1216 vnlru_free_locked(int count, struct vfsops *mnt_op) 1217 { 1218 struct vnode *vp, *mvp; 1219 struct mount *mp; 1220 int ocount; 1221 1222 mtx_assert(&vnode_list_mtx, MA_OWNED); 1223 if (count > max_vnlru_free) 1224 count = max_vnlru_free; 1225 ocount = count; 1226 mvp = vnode_list_free_marker; 1227 vp = mvp; 1228 for (;;) { 1229 if (count == 0) { 1230 break; 1231 } 1232 vp = TAILQ_NEXT(vp, v_vnodelist); 1233 if (__predict_false(vp == NULL)) { 1234 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1235 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist); 1236 break; 1237 } 1238 if (__predict_false(vp->v_type == VMARKER)) 1239 continue; 1240 if (vp->v_holdcnt > 0) 1241 continue; 1242 /* 1243 * Don't recycle if our vnode is from different type 1244 * of mount point. Note that mp is type-safe, the 1245 * check does not reach unmapped address even if 1246 * vnode is reclaimed. 1247 */ 1248 if (mnt_op != NULL && (mp = vp->v_mount) != NULL && 1249 mp->mnt_op != mnt_op) { 1250 continue; 1251 } 1252 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1253 continue; 1254 } 1255 if (!vhold_recycle_free(vp)) 1256 continue; 1257 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1258 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1259 mtx_unlock(&vnode_list_mtx); 1260 if (vtryrecycle(vp) == 0) 1261 count--; 1262 mtx_lock(&vnode_list_mtx); 1263 vp = mvp; 1264 } 1265 return (ocount - count); 1266 } 1267 1268 void 1269 vnlru_free(int count, struct vfsops *mnt_op) 1270 { 1271 1272 mtx_lock(&vnode_list_mtx); 1273 vnlru_free_locked(count, mnt_op); 1274 mtx_unlock(&vnode_list_mtx); 1275 } 1276 1277 static void 1278 vnlru_recalc(void) 1279 { 1280 1281 mtx_assert(&vnode_list_mtx, MA_OWNED); 1282 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1283 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1284 vlowat = vhiwat / 2; 1285 } 1286 1287 /* 1288 * Attempt to recycle vnodes in a context that is always safe to block. 1289 * Calling vlrurecycle() from the bowels of filesystem code has some 1290 * interesting deadlock problems. 1291 */ 1292 static struct proc *vnlruproc; 1293 static int vnlruproc_sig; 1294 1295 /* 1296 * The main freevnodes counter is only updated when threads requeue their vnode 1297 * batches. CPUs are conditionally walked to compute a more accurate total. 1298 * 1299 * Limit how much of a slop are we willing to tolerate. Note: the actual value 1300 * at any given moment can still exceed slop, but it should not be by significant 1301 * margin in practice. 1302 */ 1303 #define VNLRU_FREEVNODES_SLOP 128 1304 1305 static __inline void 1306 vn_freevnodes_inc(void) 1307 { 1308 struct vdbatch *vd; 1309 1310 critical_enter(); 1311 vd = DPCPU_PTR(vd); 1312 vd->freevnodes++; 1313 critical_exit(); 1314 } 1315 1316 static __inline void 1317 vn_freevnodes_dec(void) 1318 { 1319 struct vdbatch *vd; 1320 1321 critical_enter(); 1322 vd = DPCPU_PTR(vd); 1323 vd->freevnodes--; 1324 critical_exit(); 1325 } 1326 1327 static u_long 1328 vnlru_read_freevnodes(void) 1329 { 1330 struct vdbatch *vd; 1331 long slop; 1332 int cpu; 1333 1334 mtx_assert(&vnode_list_mtx, MA_OWNED); 1335 if (freevnodes > freevnodes_old) 1336 slop = freevnodes - freevnodes_old; 1337 else 1338 slop = freevnodes_old - freevnodes; 1339 if (slop < VNLRU_FREEVNODES_SLOP) 1340 return (freevnodes >= 0 ? freevnodes : 0); 1341 freevnodes_old = freevnodes; 1342 CPU_FOREACH(cpu) { 1343 vd = DPCPU_ID_PTR((cpu), vd); 1344 freevnodes_old += vd->freevnodes; 1345 } 1346 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1347 } 1348 1349 static bool 1350 vnlru_under(u_long rnumvnodes, u_long limit) 1351 { 1352 u_long rfreevnodes, space; 1353 1354 if (__predict_false(rnumvnodes > desiredvnodes)) 1355 return (true); 1356 1357 space = desiredvnodes - rnumvnodes; 1358 if (space < limit) { 1359 rfreevnodes = vnlru_read_freevnodes(); 1360 if (rfreevnodes > wantfreevnodes) 1361 space += rfreevnodes - wantfreevnodes; 1362 } 1363 return (space < limit); 1364 } 1365 1366 static bool 1367 vnlru_under_unlocked(u_long rnumvnodes, u_long limit) 1368 { 1369 long rfreevnodes, space; 1370 1371 if (__predict_false(rnumvnodes > desiredvnodes)) 1372 return (true); 1373 1374 space = desiredvnodes - rnumvnodes; 1375 if (space < limit) { 1376 rfreevnodes = atomic_load_long(&freevnodes); 1377 if (rfreevnodes > wantfreevnodes) 1378 space += rfreevnodes - wantfreevnodes; 1379 } 1380 return (space < limit); 1381 } 1382 1383 static void 1384 vnlru_kick(void) 1385 { 1386 1387 mtx_assert(&vnode_list_mtx, MA_OWNED); 1388 if (vnlruproc_sig == 0) { 1389 vnlruproc_sig = 1; 1390 wakeup(vnlruproc); 1391 } 1392 } 1393 1394 static void 1395 vnlru_proc(void) 1396 { 1397 u_long rnumvnodes, rfreevnodes, target; 1398 unsigned long onumvnodes; 1399 int done, force, trigger, usevnodes; 1400 bool reclaim_nc_src, want_reread; 1401 1402 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1403 SHUTDOWN_PRI_FIRST); 1404 1405 force = 0; 1406 want_reread = false; 1407 for (;;) { 1408 kproc_suspend_check(vnlruproc); 1409 mtx_lock(&vnode_list_mtx); 1410 rnumvnodes = atomic_load_long(&numvnodes); 1411 1412 if (want_reread) { 1413 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1414 want_reread = false; 1415 } 1416 1417 /* 1418 * If numvnodes is too large (due to desiredvnodes being 1419 * adjusted using its sysctl, or emergency growth), first 1420 * try to reduce it by discarding from the free list. 1421 */ 1422 if (rnumvnodes > desiredvnodes) { 1423 vnlru_free_locked(rnumvnodes - desiredvnodes, NULL); 1424 rnumvnodes = atomic_load_long(&numvnodes); 1425 } 1426 /* 1427 * Sleep if the vnode cache is in a good state. This is 1428 * when it is not over-full and has space for about a 4% 1429 * or 9% expansion (by growing its size or inexcessively 1430 * reducing its free list). Otherwise, try to reclaim 1431 * space for a 10% expansion. 1432 */ 1433 if (vstir && force == 0) { 1434 force = 1; 1435 vstir = 0; 1436 } 1437 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1438 vnlruproc_sig = 0; 1439 wakeup(&vnlruproc_sig); 1440 msleep(vnlruproc, &vnode_list_mtx, 1441 PVFS|PDROP, "vlruwt", hz); 1442 continue; 1443 } 1444 rfreevnodes = vnlru_read_freevnodes(); 1445 1446 onumvnodes = rnumvnodes; 1447 /* 1448 * Calculate parameters for recycling. These are the same 1449 * throughout the loop to give some semblance of fairness. 1450 * The trigger point is to avoid recycling vnodes with lots 1451 * of resident pages. We aren't trying to free memory; we 1452 * are trying to recycle or at least free vnodes. 1453 */ 1454 if (rnumvnodes <= desiredvnodes) 1455 usevnodes = rnumvnodes - rfreevnodes; 1456 else 1457 usevnodes = rnumvnodes; 1458 if (usevnodes <= 0) 1459 usevnodes = 1; 1460 /* 1461 * The trigger value is is chosen to give a conservatively 1462 * large value to ensure that it alone doesn't prevent 1463 * making progress. The value can easily be so large that 1464 * it is effectively infinite in some congested and 1465 * misconfigured cases, and this is necessary. Normally 1466 * it is about 8 to 100 (pages), which is quite large. 1467 */ 1468 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1469 if (force < 2) 1470 trigger = vsmalltrigger; 1471 reclaim_nc_src = force >= 3; 1472 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1473 target = target / 10 + 1; 1474 done = vlrureclaim(reclaim_nc_src, trigger, target); 1475 mtx_unlock(&vnode_list_mtx); 1476 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1477 uma_reclaim(UMA_RECLAIM_DRAIN); 1478 if (done == 0) { 1479 if (force == 0 || force == 1) { 1480 force = 2; 1481 continue; 1482 } 1483 if (force == 2) { 1484 force = 3; 1485 continue; 1486 } 1487 want_reread = true; 1488 force = 0; 1489 vnlru_nowhere++; 1490 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1491 } else { 1492 want_reread = true; 1493 kern_yield(PRI_USER); 1494 } 1495 } 1496 } 1497 1498 static struct kproc_desc vnlru_kp = { 1499 "vnlru", 1500 vnlru_proc, 1501 &vnlruproc 1502 }; 1503 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1504 &vnlru_kp); 1505 1506 /* 1507 * Routines having to do with the management of the vnode table. 1508 */ 1509 1510 /* 1511 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1512 * before we actually vgone(). This function must be called with the vnode 1513 * held to prevent the vnode from being returned to the free list midway 1514 * through vgone(). 1515 */ 1516 static int 1517 vtryrecycle(struct vnode *vp) 1518 { 1519 struct mount *vnmp; 1520 1521 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1522 VNASSERT(vp->v_holdcnt, vp, 1523 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1524 /* 1525 * This vnode may found and locked via some other list, if so we 1526 * can't recycle it yet. 1527 */ 1528 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1529 CTR2(KTR_VFS, 1530 "%s: impossible to recycle, vp %p lock is already held", 1531 __func__, vp); 1532 vdrop(vp); 1533 return (EWOULDBLOCK); 1534 } 1535 /* 1536 * Don't recycle if its filesystem is being suspended. 1537 */ 1538 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1539 VOP_UNLOCK(vp); 1540 CTR2(KTR_VFS, 1541 "%s: impossible to recycle, cannot start the write for %p", 1542 __func__, vp); 1543 vdrop(vp); 1544 return (EBUSY); 1545 } 1546 /* 1547 * If we got this far, we need to acquire the interlock and see if 1548 * anyone picked up this vnode from another list. If not, we will 1549 * mark it with DOOMED via vgonel() so that anyone who does find it 1550 * will skip over it. 1551 */ 1552 VI_LOCK(vp); 1553 if (vp->v_usecount) { 1554 VOP_UNLOCK(vp); 1555 vdropl(vp); 1556 vn_finished_write(vnmp); 1557 CTR2(KTR_VFS, 1558 "%s: impossible to recycle, %p is already referenced", 1559 __func__, vp); 1560 return (EBUSY); 1561 } 1562 if (!VN_IS_DOOMED(vp)) { 1563 counter_u64_add(recycles_free_count, 1); 1564 vgonel(vp); 1565 } 1566 VOP_UNLOCK(vp); 1567 vdropl(vp); 1568 vn_finished_write(vnmp); 1569 return (0); 1570 } 1571 1572 /* 1573 * Allocate a new vnode. 1574 * 1575 * The operation never returns an error. Returning an error was disabled 1576 * in r145385 (dated 2005) with the following comment: 1577 * 1578 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1579 * 1580 * Given the age of this commit (almost 15 years at the time of writing this 1581 * comment) restoring the ability to fail requires a significant audit of 1582 * all codepaths. 1583 * 1584 * The routine can try to free a vnode or stall for up to 1 second waiting for 1585 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1586 */ 1587 static u_long vn_alloc_cyclecount; 1588 1589 static struct vnode * __noinline 1590 vn_alloc_hard(struct mount *mp) 1591 { 1592 u_long rnumvnodes, rfreevnodes; 1593 1594 mtx_lock(&vnode_list_mtx); 1595 rnumvnodes = atomic_load_long(&numvnodes); 1596 if (rnumvnodes + 1 < desiredvnodes) { 1597 vn_alloc_cyclecount = 0; 1598 goto alloc; 1599 } 1600 rfreevnodes = vnlru_read_freevnodes(); 1601 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1602 vn_alloc_cyclecount = 0; 1603 vstir = 1; 1604 } 1605 /* 1606 * Grow the vnode cache if it will not be above its target max 1607 * after growing. Otherwise, if the free list is nonempty, try 1608 * to reclaim 1 item from it before growing the cache (possibly 1609 * above its target max if the reclamation failed or is delayed). 1610 * Otherwise, wait for some space. In all cases, schedule 1611 * vnlru_proc() if we are getting short of space. The watermarks 1612 * should be chosen so that we never wait or even reclaim from 1613 * the free list to below its target minimum. 1614 */ 1615 if (vnlru_free_locked(1, NULL) > 0) 1616 goto alloc; 1617 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1618 /* 1619 * Wait for space for a new vnode. 1620 */ 1621 vnlru_kick(); 1622 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1623 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1624 vnlru_read_freevnodes() > 1) 1625 vnlru_free_locked(1, NULL); 1626 } 1627 alloc: 1628 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1629 if (vnlru_under(rnumvnodes, vlowat)) 1630 vnlru_kick(); 1631 mtx_unlock(&vnode_list_mtx); 1632 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 1633 } 1634 1635 static struct vnode * 1636 vn_alloc(struct mount *mp) 1637 { 1638 u_long rnumvnodes; 1639 1640 if (__predict_false(vn_alloc_cyclecount != 0)) 1641 return (vn_alloc_hard(mp)); 1642 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 1643 if (__predict_false(vnlru_under_unlocked(rnumvnodes, vlowat))) { 1644 atomic_subtract_long(&numvnodes, 1); 1645 return (vn_alloc_hard(mp)); 1646 } 1647 1648 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 1649 } 1650 1651 static void 1652 vn_free(struct vnode *vp) 1653 { 1654 1655 atomic_subtract_long(&numvnodes, 1); 1656 uma_zfree_smr(vnode_zone, vp); 1657 } 1658 1659 /* 1660 * Return the next vnode from the free list. 1661 */ 1662 int 1663 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1664 struct vnode **vpp) 1665 { 1666 struct vnode *vp; 1667 struct thread *td; 1668 struct lock_object *lo; 1669 1670 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1671 1672 KASSERT(vops->registered, 1673 ("%s: not registered vector op %p\n", __func__, vops)); 1674 1675 td = curthread; 1676 if (td->td_vp_reserved != NULL) { 1677 vp = td->td_vp_reserved; 1678 td->td_vp_reserved = NULL; 1679 } else { 1680 vp = vn_alloc(mp); 1681 } 1682 counter_u64_add(vnodes_created, 1); 1683 /* 1684 * Locks are given the generic name "vnode" when created. 1685 * Follow the historic practice of using the filesystem 1686 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1687 * 1688 * Locks live in a witness group keyed on their name. Thus, 1689 * when a lock is renamed, it must also move from the witness 1690 * group of its old name to the witness group of its new name. 1691 * 1692 * The change only needs to be made when the vnode moves 1693 * from one filesystem type to another. We ensure that each 1694 * filesystem use a single static name pointer for its tag so 1695 * that we can compare pointers rather than doing a strcmp(). 1696 */ 1697 lo = &vp->v_vnlock->lock_object; 1698 #ifdef WITNESS 1699 if (lo->lo_name != tag) { 1700 #endif 1701 lo->lo_name = tag; 1702 #ifdef WITNESS 1703 WITNESS_DESTROY(lo); 1704 WITNESS_INIT(lo, tag); 1705 } 1706 #endif 1707 /* 1708 * By default, don't allow shared locks unless filesystems opt-in. 1709 */ 1710 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1711 /* 1712 * Finalize various vnode identity bits. 1713 */ 1714 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1715 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1716 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1717 vp->v_type = VNON; 1718 vp->v_op = vops; 1719 v_init_counters(vp); 1720 vp->v_bufobj.bo_ops = &buf_ops_bio; 1721 #ifdef DIAGNOSTIC 1722 if (mp == NULL && vops != &dead_vnodeops) 1723 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1724 #endif 1725 #ifdef MAC 1726 mac_vnode_init(vp); 1727 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1728 mac_vnode_associate_singlelabel(mp, vp); 1729 #endif 1730 if (mp != NULL) { 1731 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1732 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1733 vp->v_vflag |= VV_NOKNOTE; 1734 } 1735 1736 /* 1737 * For the filesystems which do not use vfs_hash_insert(), 1738 * still initialize v_hash to have vfs_hash_index() useful. 1739 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1740 * its own hashing. 1741 */ 1742 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1743 1744 *vpp = vp; 1745 return (0); 1746 } 1747 1748 void 1749 getnewvnode_reserve(void) 1750 { 1751 struct thread *td; 1752 1753 td = curthread; 1754 MPASS(td->td_vp_reserved == NULL); 1755 td->td_vp_reserved = vn_alloc(NULL); 1756 } 1757 1758 void 1759 getnewvnode_drop_reserve(void) 1760 { 1761 struct thread *td; 1762 1763 td = curthread; 1764 if (td->td_vp_reserved != NULL) { 1765 vn_free(td->td_vp_reserved); 1766 td->td_vp_reserved = NULL; 1767 } 1768 } 1769 1770 static void __noinline 1771 freevnode(struct vnode *vp) 1772 { 1773 struct bufobj *bo; 1774 1775 /* 1776 * The vnode has been marked for destruction, so free it. 1777 * 1778 * The vnode will be returned to the zone where it will 1779 * normally remain until it is needed for another vnode. We 1780 * need to cleanup (or verify that the cleanup has already 1781 * been done) any residual data left from its current use 1782 * so as not to contaminate the freshly allocated vnode. 1783 */ 1784 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1785 /* 1786 * Paired with vgone. 1787 */ 1788 vn_seqc_write_end_locked(vp); 1789 VNPASS(vp->v_seqc_users == 0, vp); 1790 1791 bo = &vp->v_bufobj; 1792 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1793 VNPASS(vp->v_holdcnt == VHOLD_NO_SMR, vp); 1794 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1795 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1796 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1797 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1798 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1799 ("clean blk trie not empty")); 1800 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1801 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1802 ("dirty blk trie not empty")); 1803 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1804 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1805 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1806 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1807 ("Dangling rangelock waiters")); 1808 VNASSERT((vp->v_iflag & (VI_DOINGINACT | VI_OWEINACT)) == 0, vp, 1809 ("Leaked inactivation")); 1810 VI_UNLOCK(vp); 1811 #ifdef MAC 1812 mac_vnode_destroy(vp); 1813 #endif 1814 if (vp->v_pollinfo != NULL) { 1815 destroy_vpollinfo(vp->v_pollinfo); 1816 vp->v_pollinfo = NULL; 1817 } 1818 #ifdef INVARIANTS 1819 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1820 vp->v_op = NULL; 1821 #endif 1822 vp->v_mountedhere = NULL; 1823 vp->v_unpcb = NULL; 1824 vp->v_rdev = NULL; 1825 vp->v_fifoinfo = NULL; 1826 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1827 vp->v_irflag = 0; 1828 vp->v_iflag = 0; 1829 vp->v_vflag = 0; 1830 bo->bo_flag = 0; 1831 vn_free(vp); 1832 } 1833 1834 /* 1835 * Delete from old mount point vnode list, if on one. 1836 */ 1837 static void 1838 delmntque(struct vnode *vp) 1839 { 1840 struct mount *mp; 1841 1842 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 1843 1844 mp = vp->v_mount; 1845 if (mp == NULL) 1846 return; 1847 MNT_ILOCK(mp); 1848 VI_LOCK(vp); 1849 vp->v_mount = NULL; 1850 VI_UNLOCK(vp); 1851 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1852 ("bad mount point vnode list size")); 1853 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1854 mp->mnt_nvnodelistsize--; 1855 MNT_REL(mp); 1856 MNT_IUNLOCK(mp); 1857 } 1858 1859 static void 1860 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1861 { 1862 1863 vp->v_data = NULL; 1864 vp->v_op = &dead_vnodeops; 1865 vgone(vp); 1866 vput(vp); 1867 } 1868 1869 /* 1870 * Insert into list of vnodes for the new mount point, if available. 1871 */ 1872 int 1873 insmntque1(struct vnode *vp, struct mount *mp, 1874 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1875 { 1876 1877 KASSERT(vp->v_mount == NULL, 1878 ("insmntque: vnode already on per mount vnode list")); 1879 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1880 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1881 1882 /* 1883 * We acquire the vnode interlock early to ensure that the 1884 * vnode cannot be recycled by another process releasing a 1885 * holdcnt on it before we get it on both the vnode list 1886 * and the active vnode list. The mount mutex protects only 1887 * manipulation of the vnode list and the vnode freelist 1888 * mutex protects only manipulation of the active vnode list. 1889 * Hence the need to hold the vnode interlock throughout. 1890 */ 1891 MNT_ILOCK(mp); 1892 VI_LOCK(vp); 1893 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1894 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1895 mp->mnt_nvnodelistsize == 0)) && 1896 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1897 VI_UNLOCK(vp); 1898 MNT_IUNLOCK(mp); 1899 if (dtr != NULL) 1900 dtr(vp, dtr_arg); 1901 return (EBUSY); 1902 } 1903 vp->v_mount = mp; 1904 MNT_REF(mp); 1905 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1906 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1907 ("neg mount point vnode list size")); 1908 mp->mnt_nvnodelistsize++; 1909 VI_UNLOCK(vp); 1910 MNT_IUNLOCK(mp); 1911 return (0); 1912 } 1913 1914 int 1915 insmntque(struct vnode *vp, struct mount *mp) 1916 { 1917 1918 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1919 } 1920 1921 /* 1922 * Flush out and invalidate all buffers associated with a bufobj 1923 * Called with the underlying object locked. 1924 */ 1925 int 1926 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1927 { 1928 int error; 1929 1930 BO_LOCK(bo); 1931 if (flags & V_SAVE) { 1932 error = bufobj_wwait(bo, slpflag, slptimeo); 1933 if (error) { 1934 BO_UNLOCK(bo); 1935 return (error); 1936 } 1937 if (bo->bo_dirty.bv_cnt > 0) { 1938 BO_UNLOCK(bo); 1939 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1940 return (error); 1941 /* 1942 * XXX We could save a lock/unlock if this was only 1943 * enabled under INVARIANTS 1944 */ 1945 BO_LOCK(bo); 1946 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1947 panic("vinvalbuf: dirty bufs"); 1948 } 1949 } 1950 /* 1951 * If you alter this loop please notice that interlock is dropped and 1952 * reacquired in flushbuflist. Special care is needed to ensure that 1953 * no race conditions occur from this. 1954 */ 1955 do { 1956 error = flushbuflist(&bo->bo_clean, 1957 flags, bo, slpflag, slptimeo); 1958 if (error == 0 && !(flags & V_CLEANONLY)) 1959 error = flushbuflist(&bo->bo_dirty, 1960 flags, bo, slpflag, slptimeo); 1961 if (error != 0 && error != EAGAIN) { 1962 BO_UNLOCK(bo); 1963 return (error); 1964 } 1965 } while (error != 0); 1966 1967 /* 1968 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1969 * have write I/O in-progress but if there is a VM object then the 1970 * VM object can also have read-I/O in-progress. 1971 */ 1972 do { 1973 bufobj_wwait(bo, 0, 0); 1974 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1975 BO_UNLOCK(bo); 1976 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1977 BO_LOCK(bo); 1978 } 1979 } while (bo->bo_numoutput > 0); 1980 BO_UNLOCK(bo); 1981 1982 /* 1983 * Destroy the copy in the VM cache, too. 1984 */ 1985 if (bo->bo_object != NULL && 1986 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1987 VM_OBJECT_WLOCK(bo->bo_object); 1988 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1989 OBJPR_CLEANONLY : 0); 1990 VM_OBJECT_WUNLOCK(bo->bo_object); 1991 } 1992 1993 #ifdef INVARIANTS 1994 BO_LOCK(bo); 1995 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1996 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1997 bo->bo_clean.bv_cnt > 0)) 1998 panic("vinvalbuf: flush failed"); 1999 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 2000 bo->bo_dirty.bv_cnt > 0) 2001 panic("vinvalbuf: flush dirty failed"); 2002 BO_UNLOCK(bo); 2003 #endif 2004 return (0); 2005 } 2006 2007 /* 2008 * Flush out and invalidate all buffers associated with a vnode. 2009 * Called with the underlying object locked. 2010 */ 2011 int 2012 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 2013 { 2014 2015 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2016 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 2017 if (vp->v_object != NULL && vp->v_object->handle != vp) 2018 return (0); 2019 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 2020 } 2021 2022 /* 2023 * Flush out buffers on the specified list. 2024 * 2025 */ 2026 static int 2027 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 2028 int slptimeo) 2029 { 2030 struct buf *bp, *nbp; 2031 int retval, error; 2032 daddr_t lblkno; 2033 b_xflags_t xflags; 2034 2035 ASSERT_BO_WLOCKED(bo); 2036 2037 retval = 0; 2038 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2039 /* 2040 * If we are flushing both V_NORMAL and V_ALT buffers then 2041 * do not skip any buffers. If we are flushing only V_NORMAL 2042 * buffers then skip buffers marked as BX_ALTDATA. If we are 2043 * flushing only V_ALT buffers then skip buffers not marked 2044 * as BX_ALTDATA. 2045 */ 2046 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2047 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2048 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2049 continue; 2050 } 2051 if (nbp != NULL) { 2052 lblkno = nbp->b_lblkno; 2053 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2054 } 2055 retval = EAGAIN; 2056 error = BUF_TIMELOCK(bp, 2057 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2058 "flushbuf", slpflag, slptimeo); 2059 if (error) { 2060 BO_LOCK(bo); 2061 return (error != ENOLCK ? error : EAGAIN); 2062 } 2063 KASSERT(bp->b_bufobj == bo, 2064 ("bp %p wrong b_bufobj %p should be %p", 2065 bp, bp->b_bufobj, bo)); 2066 /* 2067 * XXX Since there are no node locks for NFS, I 2068 * believe there is a slight chance that a delayed 2069 * write will occur while sleeping just above, so 2070 * check for it. 2071 */ 2072 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2073 (flags & V_SAVE)) { 2074 bremfree(bp); 2075 bp->b_flags |= B_ASYNC; 2076 bwrite(bp); 2077 BO_LOCK(bo); 2078 return (EAGAIN); /* XXX: why not loop ? */ 2079 } 2080 bremfree(bp); 2081 bp->b_flags |= (B_INVAL | B_RELBUF); 2082 bp->b_flags &= ~B_ASYNC; 2083 brelse(bp); 2084 BO_LOCK(bo); 2085 if (nbp == NULL) 2086 break; 2087 nbp = gbincore(bo, lblkno); 2088 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2089 != xflags) 2090 break; /* nbp invalid */ 2091 } 2092 return (retval); 2093 } 2094 2095 int 2096 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2097 { 2098 struct buf *bp; 2099 int error; 2100 daddr_t lblkno; 2101 2102 ASSERT_BO_LOCKED(bo); 2103 2104 for (lblkno = startn;;) { 2105 again: 2106 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2107 if (bp == NULL || bp->b_lblkno >= endn || 2108 bp->b_lblkno < startn) 2109 break; 2110 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2111 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2112 if (error != 0) { 2113 BO_RLOCK(bo); 2114 if (error == ENOLCK) 2115 goto again; 2116 return (error); 2117 } 2118 KASSERT(bp->b_bufobj == bo, 2119 ("bp %p wrong b_bufobj %p should be %p", 2120 bp, bp->b_bufobj, bo)); 2121 lblkno = bp->b_lblkno + 1; 2122 if ((bp->b_flags & B_MANAGED) == 0) 2123 bremfree(bp); 2124 bp->b_flags |= B_RELBUF; 2125 /* 2126 * In the VMIO case, use the B_NOREUSE flag to hint that the 2127 * pages backing each buffer in the range are unlikely to be 2128 * reused. Dirty buffers will have the hint applied once 2129 * they've been written. 2130 */ 2131 if ((bp->b_flags & B_VMIO) != 0) 2132 bp->b_flags |= B_NOREUSE; 2133 brelse(bp); 2134 BO_RLOCK(bo); 2135 } 2136 return (0); 2137 } 2138 2139 /* 2140 * Truncate a file's buffer and pages to a specified length. This 2141 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2142 * sync activity. 2143 */ 2144 int 2145 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2146 { 2147 struct buf *bp, *nbp; 2148 struct bufobj *bo; 2149 daddr_t startlbn; 2150 2151 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2152 vp, blksize, (uintmax_t)length); 2153 2154 /* 2155 * Round up to the *next* lbn. 2156 */ 2157 startlbn = howmany(length, blksize); 2158 2159 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2160 2161 bo = &vp->v_bufobj; 2162 restart_unlocked: 2163 BO_LOCK(bo); 2164 2165 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2166 ; 2167 2168 if (length > 0) { 2169 restartsync: 2170 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2171 if (bp->b_lblkno > 0) 2172 continue; 2173 /* 2174 * Since we hold the vnode lock this should only 2175 * fail if we're racing with the buf daemon. 2176 */ 2177 if (BUF_LOCK(bp, 2178 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2179 BO_LOCKPTR(bo)) == ENOLCK) 2180 goto restart_unlocked; 2181 2182 VNASSERT((bp->b_flags & B_DELWRI), vp, 2183 ("buf(%p) on dirty queue without DELWRI", bp)); 2184 2185 bremfree(bp); 2186 bawrite(bp); 2187 BO_LOCK(bo); 2188 goto restartsync; 2189 } 2190 } 2191 2192 bufobj_wwait(bo, 0, 0); 2193 BO_UNLOCK(bo); 2194 vnode_pager_setsize(vp, length); 2195 2196 return (0); 2197 } 2198 2199 /* 2200 * Invalidate the cached pages of a file's buffer within the range of block 2201 * numbers [startlbn, endlbn). 2202 */ 2203 void 2204 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2205 int blksize) 2206 { 2207 struct bufobj *bo; 2208 off_t start, end; 2209 2210 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2211 2212 start = blksize * startlbn; 2213 end = blksize * endlbn; 2214 2215 bo = &vp->v_bufobj; 2216 BO_LOCK(bo); 2217 MPASS(blksize == bo->bo_bsize); 2218 2219 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2220 ; 2221 2222 BO_UNLOCK(bo); 2223 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2224 } 2225 2226 static int 2227 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2228 daddr_t startlbn, daddr_t endlbn) 2229 { 2230 struct buf *bp, *nbp; 2231 bool anyfreed; 2232 2233 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2234 ASSERT_BO_LOCKED(bo); 2235 2236 do { 2237 anyfreed = false; 2238 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2239 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2240 continue; 2241 if (BUF_LOCK(bp, 2242 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2243 BO_LOCKPTR(bo)) == ENOLCK) { 2244 BO_LOCK(bo); 2245 return (EAGAIN); 2246 } 2247 2248 bremfree(bp); 2249 bp->b_flags |= B_INVAL | B_RELBUF; 2250 bp->b_flags &= ~B_ASYNC; 2251 brelse(bp); 2252 anyfreed = true; 2253 2254 BO_LOCK(bo); 2255 if (nbp != NULL && 2256 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2257 nbp->b_vp != vp || 2258 (nbp->b_flags & B_DELWRI) != 0)) 2259 return (EAGAIN); 2260 } 2261 2262 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2263 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2264 continue; 2265 if (BUF_LOCK(bp, 2266 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2267 BO_LOCKPTR(bo)) == ENOLCK) { 2268 BO_LOCK(bo); 2269 return (EAGAIN); 2270 } 2271 bremfree(bp); 2272 bp->b_flags |= B_INVAL | B_RELBUF; 2273 bp->b_flags &= ~B_ASYNC; 2274 brelse(bp); 2275 anyfreed = true; 2276 2277 BO_LOCK(bo); 2278 if (nbp != NULL && 2279 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2280 (nbp->b_vp != vp) || 2281 (nbp->b_flags & B_DELWRI) == 0)) 2282 return (EAGAIN); 2283 } 2284 } while (anyfreed); 2285 return (0); 2286 } 2287 2288 static void 2289 buf_vlist_remove(struct buf *bp) 2290 { 2291 struct bufv *bv; 2292 b_xflags_t flags; 2293 2294 flags = bp->b_xflags; 2295 2296 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2297 ASSERT_BO_WLOCKED(bp->b_bufobj); 2298 KASSERT((flags & (BX_VNDIRTY | BX_VNCLEAN)) != 0 && 2299 (flags & (BX_VNDIRTY | BX_VNCLEAN)) != (BX_VNDIRTY | BX_VNCLEAN), 2300 ("%s: buffer %p has invalid queue state", __func__, bp)); 2301 2302 if ((flags & BX_VNDIRTY) != 0) 2303 bv = &bp->b_bufobj->bo_dirty; 2304 else 2305 bv = &bp->b_bufobj->bo_clean; 2306 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2307 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2308 bv->bv_cnt--; 2309 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2310 } 2311 2312 /* 2313 * Add the buffer to the sorted clean or dirty block list. 2314 * 2315 * NOTE: xflags is passed as a constant, optimizing this inline function! 2316 */ 2317 static void 2318 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2319 { 2320 struct bufv *bv; 2321 struct buf *n; 2322 int error; 2323 2324 ASSERT_BO_WLOCKED(bo); 2325 KASSERT((bo->bo_flag & BO_NOBUFS) == 0, 2326 ("buf_vlist_add: bo %p does not allow bufs", bo)); 2327 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2328 ("dead bo %p", bo)); 2329 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2330 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2331 bp->b_xflags |= xflags; 2332 if (xflags & BX_VNDIRTY) 2333 bv = &bo->bo_dirty; 2334 else 2335 bv = &bo->bo_clean; 2336 2337 /* 2338 * Keep the list ordered. Optimize empty list insertion. Assume 2339 * we tend to grow at the tail so lookup_le should usually be cheaper 2340 * than _ge. 2341 */ 2342 if (bv->bv_cnt == 0 || 2343 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2344 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2345 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2346 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2347 else 2348 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2349 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2350 if (error) 2351 panic("buf_vlist_add: Preallocated nodes insufficient."); 2352 bv->bv_cnt++; 2353 } 2354 2355 /* 2356 * Look up a buffer using the buffer tries. 2357 */ 2358 struct buf * 2359 gbincore(struct bufobj *bo, daddr_t lblkno) 2360 { 2361 struct buf *bp; 2362 2363 ASSERT_BO_LOCKED(bo); 2364 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2365 if (bp != NULL) 2366 return (bp); 2367 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno)); 2368 } 2369 2370 /* 2371 * Look up a buf using the buffer tries, without the bufobj lock. This relies 2372 * on SMR for safe lookup, and bufs being in a no-free zone to provide type 2373 * stability of the result. Like other lockless lookups, the found buf may 2374 * already be invalid by the time this function returns. 2375 */ 2376 struct buf * 2377 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno) 2378 { 2379 struct buf *bp; 2380 2381 ASSERT_BO_UNLOCKED(bo); 2382 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno); 2383 if (bp != NULL) 2384 return (bp); 2385 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno)); 2386 } 2387 2388 /* 2389 * Associate a buffer with a vnode. 2390 */ 2391 void 2392 bgetvp(struct vnode *vp, struct buf *bp) 2393 { 2394 struct bufobj *bo; 2395 2396 bo = &vp->v_bufobj; 2397 ASSERT_BO_WLOCKED(bo); 2398 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2399 2400 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2401 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2402 ("bgetvp: bp already attached! %p", bp)); 2403 2404 vhold(vp); 2405 bp->b_vp = vp; 2406 bp->b_bufobj = bo; 2407 /* 2408 * Insert onto list for new vnode. 2409 */ 2410 buf_vlist_add(bp, bo, BX_VNCLEAN); 2411 } 2412 2413 /* 2414 * Disassociate a buffer from a vnode. 2415 */ 2416 void 2417 brelvp(struct buf *bp) 2418 { 2419 struct bufobj *bo; 2420 struct vnode *vp; 2421 2422 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2423 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2424 2425 /* 2426 * Delete from old vnode list, if on one. 2427 */ 2428 vp = bp->b_vp; /* XXX */ 2429 bo = bp->b_bufobj; 2430 BO_LOCK(bo); 2431 buf_vlist_remove(bp); 2432 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2433 bo->bo_flag &= ~BO_ONWORKLST; 2434 mtx_lock(&sync_mtx); 2435 LIST_REMOVE(bo, bo_synclist); 2436 syncer_worklist_len--; 2437 mtx_unlock(&sync_mtx); 2438 } 2439 bp->b_vp = NULL; 2440 bp->b_bufobj = NULL; 2441 BO_UNLOCK(bo); 2442 vdrop(vp); 2443 } 2444 2445 /* 2446 * Add an item to the syncer work queue. 2447 */ 2448 static void 2449 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2450 { 2451 int slot; 2452 2453 ASSERT_BO_WLOCKED(bo); 2454 2455 mtx_lock(&sync_mtx); 2456 if (bo->bo_flag & BO_ONWORKLST) 2457 LIST_REMOVE(bo, bo_synclist); 2458 else { 2459 bo->bo_flag |= BO_ONWORKLST; 2460 syncer_worklist_len++; 2461 } 2462 2463 if (delay > syncer_maxdelay - 2) 2464 delay = syncer_maxdelay - 2; 2465 slot = (syncer_delayno + delay) & syncer_mask; 2466 2467 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2468 mtx_unlock(&sync_mtx); 2469 } 2470 2471 static int 2472 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2473 { 2474 int error, len; 2475 2476 mtx_lock(&sync_mtx); 2477 len = syncer_worklist_len - sync_vnode_count; 2478 mtx_unlock(&sync_mtx); 2479 error = SYSCTL_OUT(req, &len, sizeof(len)); 2480 return (error); 2481 } 2482 2483 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2484 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2485 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2486 2487 static struct proc *updateproc; 2488 static void sched_sync(void); 2489 static struct kproc_desc up_kp = { 2490 "syncer", 2491 sched_sync, 2492 &updateproc 2493 }; 2494 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2495 2496 static int 2497 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2498 { 2499 struct vnode *vp; 2500 struct mount *mp; 2501 2502 *bo = LIST_FIRST(slp); 2503 if (*bo == NULL) 2504 return (0); 2505 vp = bo2vnode(*bo); 2506 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2507 return (1); 2508 /* 2509 * We use vhold in case the vnode does not 2510 * successfully sync. vhold prevents the vnode from 2511 * going away when we unlock the sync_mtx so that 2512 * we can acquire the vnode interlock. 2513 */ 2514 vholdl(vp); 2515 mtx_unlock(&sync_mtx); 2516 VI_UNLOCK(vp); 2517 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2518 vdrop(vp); 2519 mtx_lock(&sync_mtx); 2520 return (*bo == LIST_FIRST(slp)); 2521 } 2522 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2523 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2524 VOP_UNLOCK(vp); 2525 vn_finished_write(mp); 2526 BO_LOCK(*bo); 2527 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2528 /* 2529 * Put us back on the worklist. The worklist 2530 * routine will remove us from our current 2531 * position and then add us back in at a later 2532 * position. 2533 */ 2534 vn_syncer_add_to_worklist(*bo, syncdelay); 2535 } 2536 BO_UNLOCK(*bo); 2537 vdrop(vp); 2538 mtx_lock(&sync_mtx); 2539 return (0); 2540 } 2541 2542 static int first_printf = 1; 2543 2544 /* 2545 * System filesystem synchronizer daemon. 2546 */ 2547 static void 2548 sched_sync(void) 2549 { 2550 struct synclist *next, *slp; 2551 struct bufobj *bo; 2552 long starttime; 2553 struct thread *td = curthread; 2554 int last_work_seen; 2555 int net_worklist_len; 2556 int syncer_final_iter; 2557 int error; 2558 2559 last_work_seen = 0; 2560 syncer_final_iter = 0; 2561 syncer_state = SYNCER_RUNNING; 2562 starttime = time_uptime; 2563 td->td_pflags |= TDP_NORUNNINGBUF; 2564 2565 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2566 SHUTDOWN_PRI_LAST); 2567 2568 mtx_lock(&sync_mtx); 2569 for (;;) { 2570 if (syncer_state == SYNCER_FINAL_DELAY && 2571 syncer_final_iter == 0) { 2572 mtx_unlock(&sync_mtx); 2573 kproc_suspend_check(td->td_proc); 2574 mtx_lock(&sync_mtx); 2575 } 2576 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2577 if (syncer_state != SYNCER_RUNNING && 2578 starttime != time_uptime) { 2579 if (first_printf) { 2580 printf("\nSyncing disks, vnodes remaining... "); 2581 first_printf = 0; 2582 } 2583 printf("%d ", net_worklist_len); 2584 } 2585 starttime = time_uptime; 2586 2587 /* 2588 * Push files whose dirty time has expired. Be careful 2589 * of interrupt race on slp queue. 2590 * 2591 * Skip over empty worklist slots when shutting down. 2592 */ 2593 do { 2594 slp = &syncer_workitem_pending[syncer_delayno]; 2595 syncer_delayno += 1; 2596 if (syncer_delayno == syncer_maxdelay) 2597 syncer_delayno = 0; 2598 next = &syncer_workitem_pending[syncer_delayno]; 2599 /* 2600 * If the worklist has wrapped since the 2601 * it was emptied of all but syncer vnodes, 2602 * switch to the FINAL_DELAY state and run 2603 * for one more second. 2604 */ 2605 if (syncer_state == SYNCER_SHUTTING_DOWN && 2606 net_worklist_len == 0 && 2607 last_work_seen == syncer_delayno) { 2608 syncer_state = SYNCER_FINAL_DELAY; 2609 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2610 } 2611 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2612 syncer_worklist_len > 0); 2613 2614 /* 2615 * Keep track of the last time there was anything 2616 * on the worklist other than syncer vnodes. 2617 * Return to the SHUTTING_DOWN state if any 2618 * new work appears. 2619 */ 2620 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2621 last_work_seen = syncer_delayno; 2622 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2623 syncer_state = SYNCER_SHUTTING_DOWN; 2624 while (!LIST_EMPTY(slp)) { 2625 error = sync_vnode(slp, &bo, td); 2626 if (error == 1) { 2627 LIST_REMOVE(bo, bo_synclist); 2628 LIST_INSERT_HEAD(next, bo, bo_synclist); 2629 continue; 2630 } 2631 2632 if (first_printf == 0) { 2633 /* 2634 * Drop the sync mutex, because some watchdog 2635 * drivers need to sleep while patting 2636 */ 2637 mtx_unlock(&sync_mtx); 2638 wdog_kern_pat(WD_LASTVAL); 2639 mtx_lock(&sync_mtx); 2640 } 2641 } 2642 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2643 syncer_final_iter--; 2644 /* 2645 * The variable rushjob allows the kernel to speed up the 2646 * processing of the filesystem syncer process. A rushjob 2647 * value of N tells the filesystem syncer to process the next 2648 * N seconds worth of work on its queue ASAP. Currently rushjob 2649 * is used by the soft update code to speed up the filesystem 2650 * syncer process when the incore state is getting so far 2651 * ahead of the disk that the kernel memory pool is being 2652 * threatened with exhaustion. 2653 */ 2654 if (rushjob > 0) { 2655 rushjob -= 1; 2656 continue; 2657 } 2658 /* 2659 * Just sleep for a short period of time between 2660 * iterations when shutting down to allow some I/O 2661 * to happen. 2662 * 2663 * If it has taken us less than a second to process the 2664 * current work, then wait. Otherwise start right over 2665 * again. We can still lose time if any single round 2666 * takes more than two seconds, but it does not really 2667 * matter as we are just trying to generally pace the 2668 * filesystem activity. 2669 */ 2670 if (syncer_state != SYNCER_RUNNING || 2671 time_uptime == starttime) { 2672 thread_lock(td); 2673 sched_prio(td, PPAUSE); 2674 thread_unlock(td); 2675 } 2676 if (syncer_state != SYNCER_RUNNING) 2677 cv_timedwait(&sync_wakeup, &sync_mtx, 2678 hz / SYNCER_SHUTDOWN_SPEEDUP); 2679 else if (time_uptime == starttime) 2680 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2681 } 2682 } 2683 2684 /* 2685 * Request the syncer daemon to speed up its work. 2686 * We never push it to speed up more than half of its 2687 * normal turn time, otherwise it could take over the cpu. 2688 */ 2689 int 2690 speedup_syncer(void) 2691 { 2692 int ret = 0; 2693 2694 mtx_lock(&sync_mtx); 2695 if (rushjob < syncdelay / 2) { 2696 rushjob += 1; 2697 stat_rush_requests += 1; 2698 ret = 1; 2699 } 2700 mtx_unlock(&sync_mtx); 2701 cv_broadcast(&sync_wakeup); 2702 return (ret); 2703 } 2704 2705 /* 2706 * Tell the syncer to speed up its work and run though its work 2707 * list several times, then tell it to shut down. 2708 */ 2709 static void 2710 syncer_shutdown(void *arg, int howto) 2711 { 2712 2713 if (howto & RB_NOSYNC) 2714 return; 2715 mtx_lock(&sync_mtx); 2716 syncer_state = SYNCER_SHUTTING_DOWN; 2717 rushjob = 0; 2718 mtx_unlock(&sync_mtx); 2719 cv_broadcast(&sync_wakeup); 2720 kproc_shutdown(arg, howto); 2721 } 2722 2723 void 2724 syncer_suspend(void) 2725 { 2726 2727 syncer_shutdown(updateproc, 0); 2728 } 2729 2730 void 2731 syncer_resume(void) 2732 { 2733 2734 mtx_lock(&sync_mtx); 2735 first_printf = 1; 2736 syncer_state = SYNCER_RUNNING; 2737 mtx_unlock(&sync_mtx); 2738 cv_broadcast(&sync_wakeup); 2739 kproc_resume(updateproc); 2740 } 2741 2742 /* 2743 * Move the buffer between the clean and dirty lists of its vnode. 2744 */ 2745 void 2746 reassignbuf(struct buf *bp) 2747 { 2748 struct vnode *vp; 2749 struct bufobj *bo; 2750 int delay; 2751 #ifdef INVARIANTS 2752 struct bufv *bv; 2753 #endif 2754 2755 vp = bp->b_vp; 2756 bo = bp->b_bufobj; 2757 2758 KASSERT((bp->b_flags & B_PAGING) == 0, 2759 ("%s: cannot reassign paging buffer %p", __func__, bp)); 2760 2761 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2762 bp, bp->b_vp, bp->b_flags); 2763 2764 BO_LOCK(bo); 2765 buf_vlist_remove(bp); 2766 2767 /* 2768 * If dirty, put on list of dirty buffers; otherwise insert onto list 2769 * of clean buffers. 2770 */ 2771 if (bp->b_flags & B_DELWRI) { 2772 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2773 switch (vp->v_type) { 2774 case VDIR: 2775 delay = dirdelay; 2776 break; 2777 case VCHR: 2778 delay = metadelay; 2779 break; 2780 default: 2781 delay = filedelay; 2782 } 2783 vn_syncer_add_to_worklist(bo, delay); 2784 } 2785 buf_vlist_add(bp, bo, BX_VNDIRTY); 2786 } else { 2787 buf_vlist_add(bp, bo, BX_VNCLEAN); 2788 2789 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2790 mtx_lock(&sync_mtx); 2791 LIST_REMOVE(bo, bo_synclist); 2792 syncer_worklist_len--; 2793 mtx_unlock(&sync_mtx); 2794 bo->bo_flag &= ~BO_ONWORKLST; 2795 } 2796 } 2797 #ifdef INVARIANTS 2798 bv = &bo->bo_clean; 2799 bp = TAILQ_FIRST(&bv->bv_hd); 2800 KASSERT(bp == NULL || bp->b_bufobj == bo, 2801 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2802 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2803 KASSERT(bp == NULL || bp->b_bufobj == bo, 2804 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2805 bv = &bo->bo_dirty; 2806 bp = TAILQ_FIRST(&bv->bv_hd); 2807 KASSERT(bp == NULL || bp->b_bufobj == bo, 2808 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2809 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2810 KASSERT(bp == NULL || bp->b_bufobj == bo, 2811 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2812 #endif 2813 BO_UNLOCK(bo); 2814 } 2815 2816 static void 2817 v_init_counters(struct vnode *vp) 2818 { 2819 2820 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2821 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2822 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2823 2824 refcount_init(&vp->v_holdcnt, 1); 2825 refcount_init(&vp->v_usecount, 1); 2826 } 2827 2828 /* 2829 * Grab a particular vnode from the free list, increment its 2830 * reference count and lock it. VIRF_DOOMED is set if the vnode 2831 * is being destroyed. Only callers who specify LK_RETRY will 2832 * see doomed vnodes. If inactive processing was delayed in 2833 * vput try to do it here. 2834 * 2835 * usecount is manipulated using atomics without holding any locks. 2836 * 2837 * holdcnt can be manipulated using atomics without holding any locks, 2838 * except when transitioning 1<->0, in which case the interlock is held. 2839 * 2840 * Consumers which don't guarantee liveness of the vnode can use SMR to 2841 * try to get a reference. Note this operation can fail since the vnode 2842 * may be awaiting getting freed by the time they get to it. 2843 */ 2844 enum vgetstate 2845 vget_prep_smr(struct vnode *vp) 2846 { 2847 enum vgetstate vs; 2848 2849 VFS_SMR_ASSERT_ENTERED(); 2850 2851 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2852 vs = VGET_USECOUNT; 2853 } else { 2854 if (vhold_smr(vp)) 2855 vs = VGET_HOLDCNT; 2856 else 2857 vs = VGET_NONE; 2858 } 2859 return (vs); 2860 } 2861 2862 enum vgetstate 2863 vget_prep(struct vnode *vp) 2864 { 2865 enum vgetstate vs; 2866 2867 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2868 vs = VGET_USECOUNT; 2869 } else { 2870 vhold(vp); 2871 vs = VGET_HOLDCNT; 2872 } 2873 return (vs); 2874 } 2875 2876 void 2877 vget_abort(struct vnode *vp, enum vgetstate vs) 2878 { 2879 2880 switch (vs) { 2881 case VGET_USECOUNT: 2882 vrele(vp); 2883 break; 2884 case VGET_HOLDCNT: 2885 vdrop(vp); 2886 break; 2887 default: 2888 __assert_unreachable(); 2889 } 2890 } 2891 2892 int 2893 vget(struct vnode *vp, int flags) 2894 { 2895 enum vgetstate vs; 2896 2897 vs = vget_prep(vp); 2898 return (vget_finish(vp, flags, vs)); 2899 } 2900 2901 int 2902 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2903 { 2904 int error; 2905 2906 if ((flags & LK_INTERLOCK) != 0) 2907 ASSERT_VI_LOCKED(vp, __func__); 2908 else 2909 ASSERT_VI_UNLOCKED(vp, __func__); 2910 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 2911 VNPASS(vp->v_holdcnt > 0, vp); 2912 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2913 2914 error = vn_lock(vp, flags); 2915 if (__predict_false(error != 0)) { 2916 vget_abort(vp, vs); 2917 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2918 vp); 2919 return (error); 2920 } 2921 2922 vget_finish_ref(vp, vs); 2923 return (0); 2924 } 2925 2926 void 2927 vget_finish_ref(struct vnode *vp, enum vgetstate vs) 2928 { 2929 int old; 2930 2931 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 2932 VNPASS(vp->v_holdcnt > 0, vp); 2933 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 2934 2935 if (vs == VGET_USECOUNT) 2936 return; 2937 2938 /* 2939 * We hold the vnode. If the usecount is 0 it will be utilized to keep 2940 * the vnode around. Otherwise someone else lended their hold count and 2941 * we have to drop ours. 2942 */ 2943 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2944 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 2945 if (old != 0) { 2946 #ifdef INVARIANTS 2947 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2948 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2949 #else 2950 refcount_release(&vp->v_holdcnt); 2951 #endif 2952 } 2953 } 2954 2955 void 2956 vref(struct vnode *vp) 2957 { 2958 enum vgetstate vs; 2959 2960 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2961 vs = vget_prep(vp); 2962 vget_finish_ref(vp, vs); 2963 } 2964 2965 void 2966 vrefact(struct vnode *vp) 2967 { 2968 2969 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2970 #ifdef INVARIANTS 2971 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 2972 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 2973 #else 2974 refcount_acquire(&vp->v_usecount); 2975 #endif 2976 } 2977 2978 void 2979 vlazy(struct vnode *vp) 2980 { 2981 struct mount *mp; 2982 2983 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 2984 2985 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 2986 return; 2987 /* 2988 * We may get here for inactive routines after the vnode got doomed. 2989 */ 2990 if (VN_IS_DOOMED(vp)) 2991 return; 2992 mp = vp->v_mount; 2993 mtx_lock(&mp->mnt_listmtx); 2994 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 2995 vp->v_mflag |= VMP_LAZYLIST; 2996 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 2997 mp->mnt_lazyvnodelistsize++; 2998 } 2999 mtx_unlock(&mp->mnt_listmtx); 3000 } 3001 3002 /* 3003 * This routine is only meant to be called from vgonel prior to dooming 3004 * the vnode. 3005 */ 3006 static void 3007 vunlazy_gone(struct vnode *vp) 3008 { 3009 struct mount *mp; 3010 3011 ASSERT_VOP_ELOCKED(vp, __func__); 3012 ASSERT_VI_LOCKED(vp, __func__); 3013 VNPASS(!VN_IS_DOOMED(vp), vp); 3014 3015 if (vp->v_mflag & VMP_LAZYLIST) { 3016 mp = vp->v_mount; 3017 mtx_lock(&mp->mnt_listmtx); 3018 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3019 vp->v_mflag &= ~VMP_LAZYLIST; 3020 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3021 mp->mnt_lazyvnodelistsize--; 3022 mtx_unlock(&mp->mnt_listmtx); 3023 } 3024 } 3025 3026 static void 3027 vdefer_inactive(struct vnode *vp) 3028 { 3029 3030 ASSERT_VI_LOCKED(vp, __func__); 3031 VNASSERT(vp->v_holdcnt > 0, vp, 3032 ("%s: vnode without hold count", __func__)); 3033 if (VN_IS_DOOMED(vp)) { 3034 vdropl(vp); 3035 return; 3036 } 3037 if (vp->v_iflag & VI_DEFINACT) { 3038 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3039 vdropl(vp); 3040 return; 3041 } 3042 if (vp->v_usecount > 0) { 3043 vp->v_iflag &= ~VI_OWEINACT; 3044 vdropl(vp); 3045 return; 3046 } 3047 vlazy(vp); 3048 vp->v_iflag |= VI_DEFINACT; 3049 VI_UNLOCK(vp); 3050 counter_u64_add(deferred_inact, 1); 3051 } 3052 3053 static void 3054 vdefer_inactive_unlocked(struct vnode *vp) 3055 { 3056 3057 VI_LOCK(vp); 3058 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3059 vdropl(vp); 3060 return; 3061 } 3062 vdefer_inactive(vp); 3063 } 3064 3065 enum vput_op { VRELE, VPUT, VUNREF }; 3066 3067 /* 3068 * Handle ->v_usecount transitioning to 0. 3069 * 3070 * By releasing the last usecount we take ownership of the hold count which 3071 * provides liveness of the vnode, meaning we have to vdrop. 3072 * 3073 * For all vnodes we may need to perform inactive processing. It requires an 3074 * exclusive lock on the vnode, while it is legal to call here with only a 3075 * shared lock (or no locks). If locking the vnode in an expected manner fails, 3076 * inactive processing gets deferred to the syncer. 3077 * 3078 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3079 * on the lock being held all the way until VOP_INACTIVE. This in particular 3080 * happens with UFS which adds half-constructed vnodes to the hash, where they 3081 * can be found by other code. 3082 */ 3083 static void 3084 vput_final(struct vnode *vp, enum vput_op func) 3085 { 3086 int error; 3087 bool want_unlock; 3088 3089 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3090 VNPASS(vp->v_holdcnt > 0, vp); 3091 3092 VI_LOCK(vp); 3093 3094 /* 3095 * By the time we got here someone else might have transitioned 3096 * the count back to > 0. 3097 */ 3098 if (vp->v_usecount > 0) 3099 goto out; 3100 3101 /* 3102 * If the vnode is doomed vgone already performed inactive processing 3103 * (if needed). 3104 */ 3105 if (VN_IS_DOOMED(vp)) 3106 goto out; 3107 3108 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0)) 3109 goto out; 3110 3111 if (vp->v_iflag & VI_DOINGINACT) 3112 goto out; 3113 3114 /* 3115 * Locking operations here will drop the interlock and possibly the 3116 * vnode lock, opening a window where the vnode can get doomed all the 3117 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to 3118 * perform inactive. 3119 */ 3120 vp->v_iflag |= VI_OWEINACT; 3121 want_unlock = false; 3122 error = 0; 3123 switch (func) { 3124 case VRELE: 3125 switch (VOP_ISLOCKED(vp)) { 3126 case LK_EXCLUSIVE: 3127 break; 3128 case LK_EXCLOTHER: 3129 case 0: 3130 want_unlock = true; 3131 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3132 VI_LOCK(vp); 3133 break; 3134 default: 3135 /* 3136 * The lock has at least one sharer, but we have no way 3137 * to conclude whether this is us. Play it safe and 3138 * defer processing. 3139 */ 3140 error = EAGAIN; 3141 break; 3142 } 3143 break; 3144 case VPUT: 3145 want_unlock = true; 3146 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3147 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3148 LK_NOWAIT); 3149 VI_LOCK(vp); 3150 } 3151 break; 3152 case VUNREF: 3153 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3154 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3155 VI_LOCK(vp); 3156 } 3157 break; 3158 } 3159 if (error == 0) { 3160 vinactive(vp); 3161 if (want_unlock) 3162 VOP_UNLOCK(vp); 3163 vdropl(vp); 3164 } else { 3165 vdefer_inactive(vp); 3166 } 3167 return; 3168 out: 3169 if (func == VPUT) 3170 VOP_UNLOCK(vp); 3171 vdropl(vp); 3172 } 3173 3174 /* 3175 * Decrement ->v_usecount for a vnode. 3176 * 3177 * Releasing the last use count requires additional processing, see vput_final 3178 * above for details. 3179 * 3180 * Comment above each variant denotes lock state on entry and exit. 3181 */ 3182 3183 /* 3184 * in: any 3185 * out: same as passed in 3186 */ 3187 void 3188 vrele(struct vnode *vp) 3189 { 3190 3191 ASSERT_VI_UNLOCKED(vp, __func__); 3192 if (!refcount_release(&vp->v_usecount)) 3193 return; 3194 vput_final(vp, VRELE); 3195 } 3196 3197 /* 3198 * in: locked 3199 * out: unlocked 3200 */ 3201 void 3202 vput(struct vnode *vp) 3203 { 3204 3205 ASSERT_VOP_LOCKED(vp, __func__); 3206 ASSERT_VI_UNLOCKED(vp, __func__); 3207 if (!refcount_release(&vp->v_usecount)) { 3208 VOP_UNLOCK(vp); 3209 return; 3210 } 3211 vput_final(vp, VPUT); 3212 } 3213 3214 /* 3215 * in: locked 3216 * out: locked 3217 */ 3218 void 3219 vunref(struct vnode *vp) 3220 { 3221 3222 ASSERT_VOP_LOCKED(vp, __func__); 3223 ASSERT_VI_UNLOCKED(vp, __func__); 3224 if (!refcount_release(&vp->v_usecount)) 3225 return; 3226 vput_final(vp, VUNREF); 3227 } 3228 3229 void 3230 vhold(struct vnode *vp) 3231 { 3232 int old; 3233 3234 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3235 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3236 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3237 ("%s: wrong hold count %d", __func__, old)); 3238 if (old == 0) 3239 vn_freevnodes_dec(); 3240 } 3241 3242 void 3243 vholdnz(struct vnode *vp) 3244 { 3245 3246 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3247 #ifdef INVARIANTS 3248 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3249 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3250 ("%s: wrong hold count %d", __func__, old)); 3251 #else 3252 atomic_add_int(&vp->v_holdcnt, 1); 3253 #endif 3254 } 3255 3256 /* 3257 * Grab a hold count unless the vnode is freed. 3258 * 3259 * Only use this routine if vfs smr is the only protection you have against 3260 * freeing the vnode. 3261 * 3262 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag 3263 * is not set. After the flag is set the vnode becomes immutable to anyone but 3264 * the thread which managed to set the flag. 3265 * 3266 * It may be tempting to replace the loop with: 3267 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3268 * if (count & VHOLD_NO_SMR) { 3269 * backpedal and error out; 3270 * } 3271 * 3272 * However, while this is more performant, it hinders debugging by eliminating 3273 * the previously mentioned invariant. 3274 */ 3275 bool 3276 vhold_smr(struct vnode *vp) 3277 { 3278 int count; 3279 3280 VFS_SMR_ASSERT_ENTERED(); 3281 3282 count = atomic_load_int(&vp->v_holdcnt); 3283 for (;;) { 3284 if (count & VHOLD_NO_SMR) { 3285 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3286 ("non-zero hold count with flags %d\n", count)); 3287 return (false); 3288 } 3289 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3290 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) { 3291 if (count == 0) 3292 vn_freevnodes_dec(); 3293 return (true); 3294 } 3295 } 3296 } 3297 3298 /* 3299 * Hold a free vnode for recycling. 3300 * 3301 * Note: vnode_init references this comment. 3302 * 3303 * Attempts to recycle only need the global vnode list lock and have no use for 3304 * SMR. 3305 * 3306 * However, vnodes get inserted into the global list before they get fully 3307 * initialized and stay there until UMA decides to free the memory. This in 3308 * particular means the target can be found before it becomes usable and after 3309 * it becomes recycled. Picking up such vnodes is guarded with v_holdcnt set to 3310 * VHOLD_NO_SMR. 3311 * 3312 * Note: the vnode may gain more references after we transition the count 0->1. 3313 */ 3314 static bool 3315 vhold_recycle_free(struct vnode *vp) 3316 { 3317 int count; 3318 3319 mtx_assert(&vnode_list_mtx, MA_OWNED); 3320 3321 count = atomic_load_int(&vp->v_holdcnt); 3322 for (;;) { 3323 if (count & VHOLD_NO_SMR) { 3324 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3325 ("non-zero hold count with flags %d\n", count)); 3326 return (false); 3327 } 3328 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3329 if (count > 0) { 3330 return (false); 3331 } 3332 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) { 3333 vn_freevnodes_dec(); 3334 return (true); 3335 } 3336 } 3337 } 3338 3339 static void __noinline 3340 vdbatch_process(struct vdbatch *vd) 3341 { 3342 struct vnode *vp; 3343 int i; 3344 3345 mtx_assert(&vd->lock, MA_OWNED); 3346 MPASS(curthread->td_pinned > 0); 3347 MPASS(vd->index == VDBATCH_SIZE); 3348 3349 mtx_lock(&vnode_list_mtx); 3350 critical_enter(); 3351 freevnodes += vd->freevnodes; 3352 for (i = 0; i < VDBATCH_SIZE; i++) { 3353 vp = vd->tab[i]; 3354 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3355 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3356 MPASS(vp->v_dbatchcpu != NOCPU); 3357 vp->v_dbatchcpu = NOCPU; 3358 } 3359 mtx_unlock(&vnode_list_mtx); 3360 vd->freevnodes = 0; 3361 bzero(vd->tab, sizeof(vd->tab)); 3362 vd->index = 0; 3363 critical_exit(); 3364 } 3365 3366 static void 3367 vdbatch_enqueue(struct vnode *vp) 3368 { 3369 struct vdbatch *vd; 3370 3371 ASSERT_VI_LOCKED(vp, __func__); 3372 VNASSERT(!VN_IS_DOOMED(vp), vp, 3373 ("%s: deferring requeue of a doomed vnode", __func__)); 3374 3375 if (vp->v_dbatchcpu != NOCPU) { 3376 VI_UNLOCK(vp); 3377 return; 3378 } 3379 3380 sched_pin(); 3381 vd = DPCPU_PTR(vd); 3382 mtx_lock(&vd->lock); 3383 MPASS(vd->index < VDBATCH_SIZE); 3384 MPASS(vd->tab[vd->index] == NULL); 3385 /* 3386 * A hack: we depend on being pinned so that we know what to put in 3387 * ->v_dbatchcpu. 3388 */ 3389 vp->v_dbatchcpu = curcpu; 3390 vd->tab[vd->index] = vp; 3391 vd->index++; 3392 VI_UNLOCK(vp); 3393 if (vd->index == VDBATCH_SIZE) 3394 vdbatch_process(vd); 3395 mtx_unlock(&vd->lock); 3396 sched_unpin(); 3397 } 3398 3399 /* 3400 * This routine must only be called for vnodes which are about to be 3401 * deallocated. Supporting dequeue for arbitrary vndoes would require 3402 * validating that the locked batch matches. 3403 */ 3404 static void 3405 vdbatch_dequeue(struct vnode *vp) 3406 { 3407 struct vdbatch *vd; 3408 int i; 3409 short cpu; 3410 3411 VNASSERT(vp->v_type == VBAD || vp->v_type == VNON, vp, 3412 ("%s: called for a used vnode\n", __func__)); 3413 3414 cpu = vp->v_dbatchcpu; 3415 if (cpu == NOCPU) 3416 return; 3417 3418 vd = DPCPU_ID_PTR(cpu, vd); 3419 mtx_lock(&vd->lock); 3420 for (i = 0; i < vd->index; i++) { 3421 if (vd->tab[i] != vp) 3422 continue; 3423 vp->v_dbatchcpu = NOCPU; 3424 vd->index--; 3425 vd->tab[i] = vd->tab[vd->index]; 3426 vd->tab[vd->index] = NULL; 3427 break; 3428 } 3429 mtx_unlock(&vd->lock); 3430 /* 3431 * Either we dequeued the vnode above or the target CPU beat us to it. 3432 */ 3433 MPASS(vp->v_dbatchcpu == NOCPU); 3434 } 3435 3436 /* 3437 * Drop the hold count of the vnode. If this is the last reference to 3438 * the vnode we place it on the free list unless it has been vgone'd 3439 * (marked VIRF_DOOMED) in which case we will free it. 3440 * 3441 * Because the vnode vm object keeps a hold reference on the vnode if 3442 * there is at least one resident non-cached page, the vnode cannot 3443 * leave the active list without the page cleanup done. 3444 */ 3445 static void 3446 vdrop_deactivate(struct vnode *vp) 3447 { 3448 struct mount *mp; 3449 3450 ASSERT_VI_LOCKED(vp, __func__); 3451 /* 3452 * Mark a vnode as free: remove it from its active list 3453 * and put it up for recycling on the freelist. 3454 */ 3455 VNASSERT(!VN_IS_DOOMED(vp), vp, 3456 ("vdrop: returning doomed vnode")); 3457 VNASSERT(vp->v_op != NULL, vp, 3458 ("vdrop: vnode already reclaimed.")); 3459 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 3460 ("vnode with VI_OWEINACT set")); 3461 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, 3462 ("vnode with VI_DEFINACT set")); 3463 if (vp->v_mflag & VMP_LAZYLIST) { 3464 mp = vp->v_mount; 3465 mtx_lock(&mp->mnt_listmtx); 3466 VNASSERT(vp->v_mflag & VMP_LAZYLIST, vp, ("lost VMP_LAZYLIST")); 3467 /* 3468 * Don't remove the vnode from the lazy list if another thread 3469 * has increased the hold count. It may have re-enqueued the 3470 * vnode to the lazy list and is now responsible for its 3471 * removal. 3472 */ 3473 if (vp->v_holdcnt == 0) { 3474 vp->v_mflag &= ~VMP_LAZYLIST; 3475 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3476 mp->mnt_lazyvnodelistsize--; 3477 } 3478 mtx_unlock(&mp->mnt_listmtx); 3479 } 3480 vdbatch_enqueue(vp); 3481 } 3482 3483 static void __noinline 3484 vdropl_final(struct vnode *vp) 3485 { 3486 3487 ASSERT_VI_LOCKED(vp, __func__); 3488 VNPASS(VN_IS_DOOMED(vp), vp); 3489 /* 3490 * Set the VHOLD_NO_SMR flag. 3491 * 3492 * We may be racing against vhold_smr. If they win we can just pretend 3493 * we never got this far, they will vdrop later. 3494 */ 3495 if (__predict_false(!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR))) { 3496 vn_freevnodes_inc(); 3497 VI_UNLOCK(vp); 3498 /* 3499 * We lost the aforementioned race. Any subsequent access is 3500 * invalid as they might have managed to vdropl on their own. 3501 */ 3502 return; 3503 } 3504 /* 3505 * Don't bump freevnodes as this one is going away. 3506 */ 3507 freevnode(vp); 3508 } 3509 3510 void 3511 vdrop(struct vnode *vp) 3512 { 3513 3514 ASSERT_VI_UNLOCKED(vp, __func__); 3515 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3516 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3517 return; 3518 VI_LOCK(vp); 3519 vdropl(vp); 3520 } 3521 3522 void 3523 vdropl(struct vnode *vp) 3524 { 3525 3526 ASSERT_VI_LOCKED(vp, __func__); 3527 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3528 if (!refcount_release(&vp->v_holdcnt)) { 3529 VI_UNLOCK(vp); 3530 return; 3531 } 3532 if (!VN_IS_DOOMED(vp)) { 3533 vn_freevnodes_inc(); 3534 vdrop_deactivate(vp); 3535 /* 3536 * Also unlocks the interlock. We can't assert on it as we 3537 * released our hold and by now the vnode might have been 3538 * freed. 3539 */ 3540 return; 3541 } 3542 vdropl_final(vp); 3543 } 3544 3545 /* 3546 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3547 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3548 */ 3549 static void 3550 vinactivef(struct vnode *vp) 3551 { 3552 struct vm_object *obj; 3553 3554 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3555 ASSERT_VI_LOCKED(vp, "vinactive"); 3556 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3557 ("vinactive: recursed on VI_DOINGINACT")); 3558 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3559 vp->v_iflag |= VI_DOINGINACT; 3560 vp->v_iflag &= ~VI_OWEINACT; 3561 VI_UNLOCK(vp); 3562 /* 3563 * Before moving off the active list, we must be sure that any 3564 * modified pages are converted into the vnode's dirty 3565 * buffers, since these will no longer be checked once the 3566 * vnode is on the inactive list. 3567 * 3568 * The write-out of the dirty pages is asynchronous. At the 3569 * point that VOP_INACTIVE() is called, there could still be 3570 * pending I/O and dirty pages in the object. 3571 */ 3572 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3573 vm_object_mightbedirty(obj)) { 3574 VM_OBJECT_WLOCK(obj); 3575 vm_object_page_clean(obj, 0, 0, 0); 3576 VM_OBJECT_WUNLOCK(obj); 3577 } 3578 VOP_INACTIVE(vp); 3579 VI_LOCK(vp); 3580 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3581 ("vinactive: lost VI_DOINGINACT")); 3582 vp->v_iflag &= ~VI_DOINGINACT; 3583 } 3584 3585 void 3586 vinactive(struct vnode *vp) 3587 { 3588 3589 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3590 ASSERT_VI_LOCKED(vp, "vinactive"); 3591 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3592 3593 if ((vp->v_iflag & VI_OWEINACT) == 0) 3594 return; 3595 if (vp->v_iflag & VI_DOINGINACT) 3596 return; 3597 if (vp->v_usecount > 0) { 3598 vp->v_iflag &= ~VI_OWEINACT; 3599 return; 3600 } 3601 vinactivef(vp); 3602 } 3603 3604 /* 3605 * Remove any vnodes in the vnode table belonging to mount point mp. 3606 * 3607 * If FORCECLOSE is not specified, there should not be any active ones, 3608 * return error if any are found (nb: this is a user error, not a 3609 * system error). If FORCECLOSE is specified, detach any active vnodes 3610 * that are found. 3611 * 3612 * If WRITECLOSE is set, only flush out regular file vnodes open for 3613 * writing. 3614 * 3615 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3616 * 3617 * `rootrefs' specifies the base reference count for the root vnode 3618 * of this filesystem. The root vnode is considered busy if its 3619 * v_usecount exceeds this value. On a successful return, vflush(, td) 3620 * will call vrele() on the root vnode exactly rootrefs times. 3621 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3622 * be zero. 3623 */ 3624 #ifdef DIAGNOSTIC 3625 static int busyprt = 0; /* print out busy vnodes */ 3626 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3627 #endif 3628 3629 int 3630 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3631 { 3632 struct vnode *vp, *mvp, *rootvp = NULL; 3633 struct vattr vattr; 3634 int busy = 0, error; 3635 3636 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3637 rootrefs, flags); 3638 if (rootrefs > 0) { 3639 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3640 ("vflush: bad args")); 3641 /* 3642 * Get the filesystem root vnode. We can vput() it 3643 * immediately, since with rootrefs > 0, it won't go away. 3644 */ 3645 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3646 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3647 __func__, error); 3648 return (error); 3649 } 3650 vput(rootvp); 3651 } 3652 loop: 3653 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3654 vholdl(vp); 3655 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3656 if (error) { 3657 vdrop(vp); 3658 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3659 goto loop; 3660 } 3661 /* 3662 * Skip over a vnodes marked VV_SYSTEM. 3663 */ 3664 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3665 VOP_UNLOCK(vp); 3666 vdrop(vp); 3667 continue; 3668 } 3669 /* 3670 * If WRITECLOSE is set, flush out unlinked but still open 3671 * files (even if open only for reading) and regular file 3672 * vnodes open for writing. 3673 */ 3674 if (flags & WRITECLOSE) { 3675 if (vp->v_object != NULL) { 3676 VM_OBJECT_WLOCK(vp->v_object); 3677 vm_object_page_clean(vp->v_object, 0, 0, 0); 3678 VM_OBJECT_WUNLOCK(vp->v_object); 3679 } 3680 error = VOP_FSYNC(vp, MNT_WAIT, td); 3681 if (error != 0) { 3682 VOP_UNLOCK(vp); 3683 vdrop(vp); 3684 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3685 return (error); 3686 } 3687 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3688 VI_LOCK(vp); 3689 3690 if ((vp->v_type == VNON || 3691 (error == 0 && vattr.va_nlink > 0)) && 3692 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3693 VOP_UNLOCK(vp); 3694 vdropl(vp); 3695 continue; 3696 } 3697 } else 3698 VI_LOCK(vp); 3699 /* 3700 * With v_usecount == 0, all we need to do is clear out the 3701 * vnode data structures and we are done. 3702 * 3703 * If FORCECLOSE is set, forcibly close the vnode. 3704 */ 3705 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3706 vgonel(vp); 3707 } else { 3708 busy++; 3709 #ifdef DIAGNOSTIC 3710 if (busyprt) 3711 vn_printf(vp, "vflush: busy vnode "); 3712 #endif 3713 } 3714 VOP_UNLOCK(vp); 3715 vdropl(vp); 3716 } 3717 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3718 /* 3719 * If just the root vnode is busy, and if its refcount 3720 * is equal to `rootrefs', then go ahead and kill it. 3721 */ 3722 VI_LOCK(rootvp); 3723 KASSERT(busy > 0, ("vflush: not busy")); 3724 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3725 ("vflush: usecount %d < rootrefs %d", 3726 rootvp->v_usecount, rootrefs)); 3727 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3728 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3729 vgone(rootvp); 3730 VOP_UNLOCK(rootvp); 3731 busy = 0; 3732 } else 3733 VI_UNLOCK(rootvp); 3734 } 3735 if (busy) { 3736 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3737 busy); 3738 return (EBUSY); 3739 } 3740 for (; rootrefs > 0; rootrefs--) 3741 vrele(rootvp); 3742 return (0); 3743 } 3744 3745 /* 3746 * Recycle an unused vnode to the front of the free list. 3747 */ 3748 int 3749 vrecycle(struct vnode *vp) 3750 { 3751 int recycled; 3752 3753 VI_LOCK(vp); 3754 recycled = vrecyclel(vp); 3755 VI_UNLOCK(vp); 3756 return (recycled); 3757 } 3758 3759 /* 3760 * vrecycle, with the vp interlock held. 3761 */ 3762 int 3763 vrecyclel(struct vnode *vp) 3764 { 3765 int recycled; 3766 3767 ASSERT_VOP_ELOCKED(vp, __func__); 3768 ASSERT_VI_LOCKED(vp, __func__); 3769 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3770 recycled = 0; 3771 if (vp->v_usecount == 0) { 3772 recycled = 1; 3773 vgonel(vp); 3774 } 3775 return (recycled); 3776 } 3777 3778 /* 3779 * Eliminate all activity associated with a vnode 3780 * in preparation for reuse. 3781 */ 3782 void 3783 vgone(struct vnode *vp) 3784 { 3785 VI_LOCK(vp); 3786 vgonel(vp); 3787 VI_UNLOCK(vp); 3788 } 3789 3790 static void 3791 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3792 struct vnode *lowervp __unused) 3793 { 3794 } 3795 3796 /* 3797 * Notify upper mounts about reclaimed or unlinked vnode. 3798 */ 3799 void 3800 vfs_notify_upper(struct vnode *vp, int event) 3801 { 3802 static struct vfsops vgonel_vfsops = { 3803 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3804 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3805 }; 3806 struct mount *mp, *ump, *mmp; 3807 3808 mp = vp->v_mount; 3809 if (mp == NULL) 3810 return; 3811 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3812 return; 3813 3814 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3815 mmp->mnt_op = &vgonel_vfsops; 3816 mmp->mnt_kern_flag |= MNTK_MARKER; 3817 MNT_ILOCK(mp); 3818 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3819 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3820 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3821 ump = TAILQ_NEXT(ump, mnt_upper_link); 3822 continue; 3823 } 3824 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3825 MNT_IUNLOCK(mp); 3826 switch (event) { 3827 case VFS_NOTIFY_UPPER_RECLAIM: 3828 VFS_RECLAIM_LOWERVP(ump, vp); 3829 break; 3830 case VFS_NOTIFY_UPPER_UNLINK: 3831 VFS_UNLINK_LOWERVP(ump, vp); 3832 break; 3833 default: 3834 KASSERT(0, ("invalid event %d", event)); 3835 break; 3836 } 3837 MNT_ILOCK(mp); 3838 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3839 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3840 } 3841 free(mmp, M_TEMP); 3842 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3843 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3844 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3845 wakeup(&mp->mnt_uppers); 3846 } 3847 MNT_IUNLOCK(mp); 3848 } 3849 3850 /* 3851 * vgone, with the vp interlock held. 3852 */ 3853 static void 3854 vgonel(struct vnode *vp) 3855 { 3856 struct thread *td; 3857 struct mount *mp; 3858 vm_object_t object; 3859 bool active, doinginact, oweinact; 3860 3861 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3862 ASSERT_VI_LOCKED(vp, "vgonel"); 3863 VNASSERT(vp->v_holdcnt, vp, 3864 ("vgonel: vp %p has no reference.", vp)); 3865 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3866 td = curthread; 3867 3868 /* 3869 * Don't vgonel if we're already doomed. 3870 */ 3871 if (vp->v_irflag & VIRF_DOOMED) 3872 return; 3873 /* 3874 * Paired with freevnode. 3875 */ 3876 vn_seqc_write_begin_locked(vp); 3877 vunlazy_gone(vp); 3878 vp->v_irflag |= VIRF_DOOMED; 3879 3880 /* 3881 * Check to see if the vnode is in use. If so, we have to 3882 * call VOP_CLOSE() and VOP_INACTIVE(). 3883 * 3884 * It could be that VOP_INACTIVE() requested reclamation, in 3885 * which case we should avoid recursion, so check 3886 * VI_DOINGINACT. This is not precise but good enough. 3887 */ 3888 active = vp->v_usecount > 0; 3889 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 3890 doinginact = (vp->v_iflag & VI_DOINGINACT) != 0; 3891 3892 /* 3893 * If we need to do inactive VI_OWEINACT will be set. 3894 */ 3895 if (vp->v_iflag & VI_DEFINACT) { 3896 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 3897 vp->v_iflag &= ~VI_DEFINACT; 3898 vdropl(vp); 3899 } else { 3900 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 3901 VI_UNLOCK(vp); 3902 } 3903 cache_purge_vgone(vp); 3904 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3905 3906 /* 3907 * If purging an active vnode, it must be closed and 3908 * deactivated before being reclaimed. 3909 */ 3910 if (active) 3911 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3912 if ((oweinact || active) && !doinginact) { 3913 VI_LOCK(vp); 3914 vinactivef(vp); 3915 VI_UNLOCK(vp); 3916 } 3917 if (vp->v_type == VSOCK) 3918 vfs_unp_reclaim(vp); 3919 3920 /* 3921 * Clean out any buffers associated with the vnode. 3922 * If the flush fails, just toss the buffers. 3923 */ 3924 mp = NULL; 3925 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3926 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3927 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3928 while (vinvalbuf(vp, 0, 0, 0) != 0) 3929 ; 3930 } 3931 3932 BO_LOCK(&vp->v_bufobj); 3933 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3934 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3935 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3936 vp->v_bufobj.bo_clean.bv_cnt == 0, 3937 ("vp %p bufobj not invalidated", vp)); 3938 3939 /* 3940 * For VMIO bufobj, BO_DEAD is set later, or in 3941 * vm_object_terminate() after the object's page queue is 3942 * flushed. 3943 */ 3944 object = vp->v_bufobj.bo_object; 3945 if (object == NULL) 3946 vp->v_bufobj.bo_flag |= BO_DEAD; 3947 BO_UNLOCK(&vp->v_bufobj); 3948 3949 /* 3950 * Handle the VM part. Tmpfs handles v_object on its own (the 3951 * OBJT_VNODE check). Nullfs or other bypassing filesystems 3952 * should not touch the object borrowed from the lower vnode 3953 * (the handle check). 3954 */ 3955 if (object != NULL && object->type == OBJT_VNODE && 3956 object->handle == vp) 3957 vnode_destroy_vobject(vp); 3958 3959 /* 3960 * Reclaim the vnode. 3961 */ 3962 if (VOP_RECLAIM(vp)) 3963 panic("vgone: cannot reclaim"); 3964 if (mp != NULL) 3965 vn_finished_secondary_write(mp); 3966 VNASSERT(vp->v_object == NULL, vp, 3967 ("vop_reclaim left v_object vp=%p", vp)); 3968 /* 3969 * Clear the advisory locks and wake up waiting threads. 3970 */ 3971 (void)VOP_ADVLOCKPURGE(vp); 3972 vp->v_lockf = NULL; 3973 /* 3974 * Delete from old mount point vnode list. 3975 */ 3976 delmntque(vp); 3977 /* 3978 * Done with purge, reset to the standard lock and invalidate 3979 * the vnode. 3980 */ 3981 VI_LOCK(vp); 3982 vp->v_vnlock = &vp->v_lock; 3983 vp->v_op = &dead_vnodeops; 3984 vp->v_type = VBAD; 3985 } 3986 3987 /* 3988 * Print out a description of a vnode. 3989 */ 3990 static const char * const typename[] = 3991 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3992 "VMARKER"}; 3993 3994 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0, 3995 "new hold count flag not added to vn_printf"); 3996 3997 void 3998 vn_printf(struct vnode *vp, const char *fmt, ...) 3999 { 4000 va_list ap; 4001 char buf[256], buf2[16]; 4002 u_long flags; 4003 u_int holdcnt; 4004 4005 va_start(ap, fmt); 4006 vprintf(fmt, ap); 4007 va_end(ap); 4008 printf("%p: ", (void *)vp); 4009 printf("type %s\n", typename[vp->v_type]); 4010 holdcnt = atomic_load_int(&vp->v_holdcnt); 4011 printf(" usecount %d, writecount %d, refcount %d seqc users %d", 4012 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS, 4013 vp->v_seqc_users); 4014 switch (vp->v_type) { 4015 case VDIR: 4016 printf(" mountedhere %p\n", vp->v_mountedhere); 4017 break; 4018 case VCHR: 4019 printf(" rdev %p\n", vp->v_rdev); 4020 break; 4021 case VSOCK: 4022 printf(" socket %p\n", vp->v_unpcb); 4023 break; 4024 case VFIFO: 4025 printf(" fifoinfo %p\n", vp->v_fifoinfo); 4026 break; 4027 default: 4028 printf("\n"); 4029 break; 4030 } 4031 buf[0] = '\0'; 4032 buf[1] = '\0'; 4033 if (holdcnt & VHOLD_NO_SMR) 4034 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf)); 4035 printf(" hold count flags (%s)\n", buf + 1); 4036 4037 buf[0] = '\0'; 4038 buf[1] = '\0'; 4039 if (vp->v_irflag & VIRF_DOOMED) 4040 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 4041 if (vp->v_irflag & VIRF_PGREAD) 4042 strlcat(buf, "|VIRF_PGREAD", sizeof(buf)); 4043 flags = vp->v_irflag & ~(VIRF_DOOMED | VIRF_PGREAD); 4044 if (flags != 0) { 4045 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 4046 strlcat(buf, buf2, sizeof(buf)); 4047 } 4048 if (vp->v_vflag & VV_ROOT) 4049 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4050 if (vp->v_vflag & VV_ISTTY) 4051 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4052 if (vp->v_vflag & VV_NOSYNC) 4053 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4054 if (vp->v_vflag & VV_ETERNALDEV) 4055 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4056 if (vp->v_vflag & VV_CACHEDLABEL) 4057 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4058 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4059 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4060 if (vp->v_vflag & VV_COPYONWRITE) 4061 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4062 if (vp->v_vflag & VV_SYSTEM) 4063 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4064 if (vp->v_vflag & VV_PROCDEP) 4065 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4066 if (vp->v_vflag & VV_NOKNOTE) 4067 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 4068 if (vp->v_vflag & VV_DELETED) 4069 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4070 if (vp->v_vflag & VV_MD) 4071 strlcat(buf, "|VV_MD", sizeof(buf)); 4072 if (vp->v_vflag & VV_FORCEINSMQ) 4073 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4074 if (vp->v_vflag & VV_READLINK) 4075 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4076 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4077 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 4078 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 4079 if (flags != 0) { 4080 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4081 strlcat(buf, buf2, sizeof(buf)); 4082 } 4083 if (vp->v_iflag & VI_TEXT_REF) 4084 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 4085 if (vp->v_iflag & VI_MOUNT) 4086 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4087 if (vp->v_iflag & VI_DOINGINACT) 4088 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4089 if (vp->v_iflag & VI_OWEINACT) 4090 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4091 if (vp->v_iflag & VI_DEFINACT) 4092 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4093 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | 4094 VI_OWEINACT | VI_DEFINACT); 4095 if (flags != 0) { 4096 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4097 strlcat(buf, buf2, sizeof(buf)); 4098 } 4099 if (vp->v_mflag & VMP_LAZYLIST) 4100 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4101 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4102 if (flags != 0) { 4103 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4104 strlcat(buf, buf2, sizeof(buf)); 4105 } 4106 printf(" flags (%s)\n", buf + 1); 4107 if (mtx_owned(VI_MTX(vp))) 4108 printf(" VI_LOCKed"); 4109 if (vp->v_object != NULL) 4110 printf(" v_object %p ref %d pages %d " 4111 "cleanbuf %d dirtybuf %d\n", 4112 vp->v_object, vp->v_object->ref_count, 4113 vp->v_object->resident_page_count, 4114 vp->v_bufobj.bo_clean.bv_cnt, 4115 vp->v_bufobj.bo_dirty.bv_cnt); 4116 printf(" "); 4117 lockmgr_printinfo(vp->v_vnlock); 4118 if (vp->v_data != NULL) 4119 VOP_PRINT(vp); 4120 } 4121 4122 #ifdef DDB 4123 /* 4124 * List all of the locked vnodes in the system. 4125 * Called when debugging the kernel. 4126 */ 4127 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 4128 { 4129 struct mount *mp; 4130 struct vnode *vp; 4131 4132 /* 4133 * Note: because this is DDB, we can't obey the locking semantics 4134 * for these structures, which means we could catch an inconsistent 4135 * state and dereference a nasty pointer. Not much to be done 4136 * about that. 4137 */ 4138 db_printf("Locked vnodes\n"); 4139 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4140 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4141 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4142 vn_printf(vp, "vnode "); 4143 } 4144 } 4145 } 4146 4147 /* 4148 * Show details about the given vnode. 4149 */ 4150 DB_SHOW_COMMAND(vnode, db_show_vnode) 4151 { 4152 struct vnode *vp; 4153 4154 if (!have_addr) 4155 return; 4156 vp = (struct vnode *)addr; 4157 vn_printf(vp, "vnode "); 4158 } 4159 4160 /* 4161 * Show details about the given mount point. 4162 */ 4163 DB_SHOW_COMMAND(mount, db_show_mount) 4164 { 4165 struct mount *mp; 4166 struct vfsopt *opt; 4167 struct statfs *sp; 4168 struct vnode *vp; 4169 char buf[512]; 4170 uint64_t mflags; 4171 u_int flags; 4172 4173 if (!have_addr) { 4174 /* No address given, print short info about all mount points. */ 4175 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4176 db_printf("%p %s on %s (%s)\n", mp, 4177 mp->mnt_stat.f_mntfromname, 4178 mp->mnt_stat.f_mntonname, 4179 mp->mnt_stat.f_fstypename); 4180 if (db_pager_quit) 4181 break; 4182 } 4183 db_printf("\nMore info: show mount <addr>\n"); 4184 return; 4185 } 4186 4187 mp = (struct mount *)addr; 4188 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4189 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4190 4191 buf[0] = '\0'; 4192 mflags = mp->mnt_flag; 4193 #define MNT_FLAG(flag) do { \ 4194 if (mflags & (flag)) { \ 4195 if (buf[0] != '\0') \ 4196 strlcat(buf, ", ", sizeof(buf)); \ 4197 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4198 mflags &= ~(flag); \ 4199 } \ 4200 } while (0) 4201 MNT_FLAG(MNT_RDONLY); 4202 MNT_FLAG(MNT_SYNCHRONOUS); 4203 MNT_FLAG(MNT_NOEXEC); 4204 MNT_FLAG(MNT_NOSUID); 4205 MNT_FLAG(MNT_NFS4ACLS); 4206 MNT_FLAG(MNT_UNION); 4207 MNT_FLAG(MNT_ASYNC); 4208 MNT_FLAG(MNT_SUIDDIR); 4209 MNT_FLAG(MNT_SOFTDEP); 4210 MNT_FLAG(MNT_NOSYMFOLLOW); 4211 MNT_FLAG(MNT_GJOURNAL); 4212 MNT_FLAG(MNT_MULTILABEL); 4213 MNT_FLAG(MNT_ACLS); 4214 MNT_FLAG(MNT_NOATIME); 4215 MNT_FLAG(MNT_NOCLUSTERR); 4216 MNT_FLAG(MNT_NOCLUSTERW); 4217 MNT_FLAG(MNT_SUJ); 4218 MNT_FLAG(MNT_EXRDONLY); 4219 MNT_FLAG(MNT_EXPORTED); 4220 MNT_FLAG(MNT_DEFEXPORTED); 4221 MNT_FLAG(MNT_EXPORTANON); 4222 MNT_FLAG(MNT_EXKERB); 4223 MNT_FLAG(MNT_EXPUBLIC); 4224 MNT_FLAG(MNT_LOCAL); 4225 MNT_FLAG(MNT_QUOTA); 4226 MNT_FLAG(MNT_ROOTFS); 4227 MNT_FLAG(MNT_USER); 4228 MNT_FLAG(MNT_IGNORE); 4229 MNT_FLAG(MNT_UPDATE); 4230 MNT_FLAG(MNT_DELEXPORT); 4231 MNT_FLAG(MNT_RELOAD); 4232 MNT_FLAG(MNT_FORCE); 4233 MNT_FLAG(MNT_SNAPSHOT); 4234 MNT_FLAG(MNT_BYFSID); 4235 #undef MNT_FLAG 4236 if (mflags != 0) { 4237 if (buf[0] != '\0') 4238 strlcat(buf, ", ", sizeof(buf)); 4239 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4240 "0x%016jx", mflags); 4241 } 4242 db_printf(" mnt_flag = %s\n", buf); 4243 4244 buf[0] = '\0'; 4245 flags = mp->mnt_kern_flag; 4246 #define MNT_KERN_FLAG(flag) do { \ 4247 if (flags & (flag)) { \ 4248 if (buf[0] != '\0') \ 4249 strlcat(buf, ", ", sizeof(buf)); \ 4250 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4251 flags &= ~(flag); \ 4252 } \ 4253 } while (0) 4254 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4255 MNT_KERN_FLAG(MNTK_ASYNC); 4256 MNT_KERN_FLAG(MNTK_SOFTDEP); 4257 MNT_KERN_FLAG(MNTK_DRAINING); 4258 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4259 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4260 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4261 MNT_KERN_FLAG(MNTK_NO_IOPF); 4262 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 4263 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 4264 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 4265 MNT_KERN_FLAG(MNTK_MARKER); 4266 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4267 MNT_KERN_FLAG(MNTK_FPLOOKUP); 4268 MNT_KERN_FLAG(MNTK_NOASYNC); 4269 MNT_KERN_FLAG(MNTK_UNMOUNT); 4270 MNT_KERN_FLAG(MNTK_MWAIT); 4271 MNT_KERN_FLAG(MNTK_SUSPEND); 4272 MNT_KERN_FLAG(MNTK_SUSPEND2); 4273 MNT_KERN_FLAG(MNTK_SUSPENDED); 4274 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4275 MNT_KERN_FLAG(MNTK_NOKNOTE); 4276 #undef MNT_KERN_FLAG 4277 if (flags != 0) { 4278 if (buf[0] != '\0') 4279 strlcat(buf, ", ", sizeof(buf)); 4280 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4281 "0x%08x", flags); 4282 } 4283 db_printf(" mnt_kern_flag = %s\n", buf); 4284 4285 db_printf(" mnt_opt = "); 4286 opt = TAILQ_FIRST(mp->mnt_opt); 4287 if (opt != NULL) { 4288 db_printf("%s", opt->name); 4289 opt = TAILQ_NEXT(opt, link); 4290 while (opt != NULL) { 4291 db_printf(", %s", opt->name); 4292 opt = TAILQ_NEXT(opt, link); 4293 } 4294 } 4295 db_printf("\n"); 4296 4297 sp = &mp->mnt_stat; 4298 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4299 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4300 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4301 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4302 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4303 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4304 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4305 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4306 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4307 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4308 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4309 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4310 4311 db_printf(" mnt_cred = { uid=%u ruid=%u", 4312 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4313 if (jailed(mp->mnt_cred)) 4314 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4315 db_printf(" }\n"); 4316 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4317 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4318 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4319 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4320 db_printf(" mnt_lazyvnodelistsize = %d\n", 4321 mp->mnt_lazyvnodelistsize); 4322 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4323 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4324 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4325 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4326 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4327 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4328 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4329 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4330 db_printf(" mnt_secondary_accwrites = %d\n", 4331 mp->mnt_secondary_accwrites); 4332 db_printf(" mnt_gjprovider = %s\n", 4333 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4334 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4335 4336 db_printf("\n\nList of active vnodes\n"); 4337 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4338 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4339 vn_printf(vp, "vnode "); 4340 if (db_pager_quit) 4341 break; 4342 } 4343 } 4344 db_printf("\n\nList of inactive vnodes\n"); 4345 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4346 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4347 vn_printf(vp, "vnode "); 4348 if (db_pager_quit) 4349 break; 4350 } 4351 } 4352 } 4353 #endif /* DDB */ 4354 4355 /* 4356 * Fill in a struct xvfsconf based on a struct vfsconf. 4357 */ 4358 static int 4359 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4360 { 4361 struct xvfsconf xvfsp; 4362 4363 bzero(&xvfsp, sizeof(xvfsp)); 4364 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4365 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4366 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4367 xvfsp.vfc_flags = vfsp->vfc_flags; 4368 /* 4369 * These are unused in userland, we keep them 4370 * to not break binary compatibility. 4371 */ 4372 xvfsp.vfc_vfsops = NULL; 4373 xvfsp.vfc_next = NULL; 4374 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4375 } 4376 4377 #ifdef COMPAT_FREEBSD32 4378 struct xvfsconf32 { 4379 uint32_t vfc_vfsops; 4380 char vfc_name[MFSNAMELEN]; 4381 int32_t vfc_typenum; 4382 int32_t vfc_refcount; 4383 int32_t vfc_flags; 4384 uint32_t vfc_next; 4385 }; 4386 4387 static int 4388 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4389 { 4390 struct xvfsconf32 xvfsp; 4391 4392 bzero(&xvfsp, sizeof(xvfsp)); 4393 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4394 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4395 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4396 xvfsp.vfc_flags = vfsp->vfc_flags; 4397 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4398 } 4399 #endif 4400 4401 /* 4402 * Top level filesystem related information gathering. 4403 */ 4404 static int 4405 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4406 { 4407 struct vfsconf *vfsp; 4408 int error; 4409 4410 error = 0; 4411 vfsconf_slock(); 4412 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4413 #ifdef COMPAT_FREEBSD32 4414 if (req->flags & SCTL_MASK32) 4415 error = vfsconf2x32(req, vfsp); 4416 else 4417 #endif 4418 error = vfsconf2x(req, vfsp); 4419 if (error) 4420 break; 4421 } 4422 vfsconf_sunlock(); 4423 return (error); 4424 } 4425 4426 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4427 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4428 "S,xvfsconf", "List of all configured filesystems"); 4429 4430 #ifndef BURN_BRIDGES 4431 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4432 4433 static int 4434 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4435 { 4436 int *name = (int *)arg1 - 1; /* XXX */ 4437 u_int namelen = arg2 + 1; /* XXX */ 4438 struct vfsconf *vfsp; 4439 4440 log(LOG_WARNING, "userland calling deprecated sysctl, " 4441 "please rebuild world\n"); 4442 4443 #if 1 || defined(COMPAT_PRELITE2) 4444 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4445 if (namelen == 1) 4446 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4447 #endif 4448 4449 switch (name[1]) { 4450 case VFS_MAXTYPENUM: 4451 if (namelen != 2) 4452 return (ENOTDIR); 4453 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4454 case VFS_CONF: 4455 if (namelen != 3) 4456 return (ENOTDIR); /* overloaded */ 4457 vfsconf_slock(); 4458 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4459 if (vfsp->vfc_typenum == name[2]) 4460 break; 4461 } 4462 vfsconf_sunlock(); 4463 if (vfsp == NULL) 4464 return (EOPNOTSUPP); 4465 #ifdef COMPAT_FREEBSD32 4466 if (req->flags & SCTL_MASK32) 4467 return (vfsconf2x32(req, vfsp)); 4468 else 4469 #endif 4470 return (vfsconf2x(req, vfsp)); 4471 } 4472 return (EOPNOTSUPP); 4473 } 4474 4475 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4476 CTLFLAG_MPSAFE, vfs_sysctl, 4477 "Generic filesystem"); 4478 4479 #if 1 || defined(COMPAT_PRELITE2) 4480 4481 static int 4482 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4483 { 4484 int error; 4485 struct vfsconf *vfsp; 4486 struct ovfsconf ovfs; 4487 4488 vfsconf_slock(); 4489 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4490 bzero(&ovfs, sizeof(ovfs)); 4491 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4492 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4493 ovfs.vfc_index = vfsp->vfc_typenum; 4494 ovfs.vfc_refcount = vfsp->vfc_refcount; 4495 ovfs.vfc_flags = vfsp->vfc_flags; 4496 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4497 if (error != 0) { 4498 vfsconf_sunlock(); 4499 return (error); 4500 } 4501 } 4502 vfsconf_sunlock(); 4503 return (0); 4504 } 4505 4506 #endif /* 1 || COMPAT_PRELITE2 */ 4507 #endif /* !BURN_BRIDGES */ 4508 4509 #define KINFO_VNODESLOP 10 4510 #ifdef notyet 4511 /* 4512 * Dump vnode list (via sysctl). 4513 */ 4514 /* ARGSUSED */ 4515 static int 4516 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4517 { 4518 struct xvnode *xvn; 4519 struct mount *mp; 4520 struct vnode *vp; 4521 int error, len, n; 4522 4523 /* 4524 * Stale numvnodes access is not fatal here. 4525 */ 4526 req->lock = 0; 4527 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4528 if (!req->oldptr) 4529 /* Make an estimate */ 4530 return (SYSCTL_OUT(req, 0, len)); 4531 4532 error = sysctl_wire_old_buffer(req, 0); 4533 if (error != 0) 4534 return (error); 4535 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4536 n = 0; 4537 mtx_lock(&mountlist_mtx); 4538 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4539 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4540 continue; 4541 MNT_ILOCK(mp); 4542 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4543 if (n == len) 4544 break; 4545 vref(vp); 4546 xvn[n].xv_size = sizeof *xvn; 4547 xvn[n].xv_vnode = vp; 4548 xvn[n].xv_id = 0; /* XXX compat */ 4549 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4550 XV_COPY(usecount); 4551 XV_COPY(writecount); 4552 XV_COPY(holdcnt); 4553 XV_COPY(mount); 4554 XV_COPY(numoutput); 4555 XV_COPY(type); 4556 #undef XV_COPY 4557 xvn[n].xv_flag = vp->v_vflag; 4558 4559 switch (vp->v_type) { 4560 case VREG: 4561 case VDIR: 4562 case VLNK: 4563 break; 4564 case VBLK: 4565 case VCHR: 4566 if (vp->v_rdev == NULL) { 4567 vrele(vp); 4568 continue; 4569 } 4570 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4571 break; 4572 case VSOCK: 4573 xvn[n].xv_socket = vp->v_socket; 4574 break; 4575 case VFIFO: 4576 xvn[n].xv_fifo = vp->v_fifoinfo; 4577 break; 4578 case VNON: 4579 case VBAD: 4580 default: 4581 /* shouldn't happen? */ 4582 vrele(vp); 4583 continue; 4584 } 4585 vrele(vp); 4586 ++n; 4587 } 4588 MNT_IUNLOCK(mp); 4589 mtx_lock(&mountlist_mtx); 4590 vfs_unbusy(mp); 4591 if (n == len) 4592 break; 4593 } 4594 mtx_unlock(&mountlist_mtx); 4595 4596 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4597 free(xvn, M_TEMP); 4598 return (error); 4599 } 4600 4601 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4602 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4603 ""); 4604 #endif 4605 4606 static void 4607 unmount_or_warn(struct mount *mp) 4608 { 4609 int error; 4610 4611 error = dounmount(mp, MNT_FORCE, curthread); 4612 if (error != 0) { 4613 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4614 if (error == EBUSY) 4615 printf("BUSY)\n"); 4616 else 4617 printf("%d)\n", error); 4618 } 4619 } 4620 4621 /* 4622 * Unmount all filesystems. The list is traversed in reverse order 4623 * of mounting to avoid dependencies. 4624 */ 4625 void 4626 vfs_unmountall(void) 4627 { 4628 struct mount *mp, *tmp; 4629 4630 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4631 4632 /* 4633 * Since this only runs when rebooting, it is not interlocked. 4634 */ 4635 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4636 vfs_ref(mp); 4637 4638 /* 4639 * Forcibly unmounting "/dev" before "/" would prevent clean 4640 * unmount of the latter. 4641 */ 4642 if (mp == rootdevmp) 4643 continue; 4644 4645 unmount_or_warn(mp); 4646 } 4647 4648 if (rootdevmp != NULL) 4649 unmount_or_warn(rootdevmp); 4650 } 4651 4652 static void 4653 vfs_deferred_inactive(struct vnode *vp, int lkflags) 4654 { 4655 4656 ASSERT_VI_LOCKED(vp, __func__); 4657 VNASSERT((vp->v_iflag & VI_DEFINACT) == 0, vp, ("VI_DEFINACT still set")); 4658 if ((vp->v_iflag & VI_OWEINACT) == 0) { 4659 vdropl(vp); 4660 return; 4661 } 4662 if (vn_lock(vp, lkflags) == 0) { 4663 VI_LOCK(vp); 4664 vinactive(vp); 4665 VOP_UNLOCK(vp); 4666 vdropl(vp); 4667 return; 4668 } 4669 vdefer_inactive_unlocked(vp); 4670 } 4671 4672 static int 4673 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 4674 { 4675 4676 return (vp->v_iflag & VI_DEFINACT); 4677 } 4678 4679 static void __noinline 4680 vfs_periodic_inactive(struct mount *mp, int flags) 4681 { 4682 struct vnode *vp, *mvp; 4683 int lkflags; 4684 4685 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4686 if (flags != MNT_WAIT) 4687 lkflags |= LK_NOWAIT; 4688 4689 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 4690 if ((vp->v_iflag & VI_DEFINACT) == 0) { 4691 VI_UNLOCK(vp); 4692 continue; 4693 } 4694 vp->v_iflag &= ~VI_DEFINACT; 4695 vfs_deferred_inactive(vp, lkflags); 4696 } 4697 } 4698 4699 static inline bool 4700 vfs_want_msync(struct vnode *vp) 4701 { 4702 struct vm_object *obj; 4703 4704 /* 4705 * This test may be performed without any locks held. 4706 * We rely on vm_object's type stability. 4707 */ 4708 if (vp->v_vflag & VV_NOSYNC) 4709 return (false); 4710 obj = vp->v_object; 4711 return (obj != NULL && vm_object_mightbedirty(obj)); 4712 } 4713 4714 static int 4715 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 4716 { 4717 4718 if (vp->v_vflag & VV_NOSYNC) 4719 return (false); 4720 if (vp->v_iflag & VI_DEFINACT) 4721 return (true); 4722 return (vfs_want_msync(vp)); 4723 } 4724 4725 static void __noinline 4726 vfs_periodic_msync_inactive(struct mount *mp, int flags) 4727 { 4728 struct vnode *vp, *mvp; 4729 struct vm_object *obj; 4730 int lkflags, objflags; 4731 bool seen_defer; 4732 4733 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 4734 if (flags != MNT_WAIT) { 4735 lkflags |= LK_NOWAIT; 4736 objflags = OBJPC_NOSYNC; 4737 } else { 4738 objflags = OBJPC_SYNC; 4739 } 4740 4741 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 4742 seen_defer = false; 4743 if (vp->v_iflag & VI_DEFINACT) { 4744 vp->v_iflag &= ~VI_DEFINACT; 4745 seen_defer = true; 4746 } 4747 if (!vfs_want_msync(vp)) { 4748 if (seen_defer) 4749 vfs_deferred_inactive(vp, lkflags); 4750 else 4751 VI_UNLOCK(vp); 4752 continue; 4753 } 4754 if (vget(vp, lkflags) == 0) { 4755 obj = vp->v_object; 4756 if (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0) { 4757 VM_OBJECT_WLOCK(obj); 4758 vm_object_page_clean(obj, 0, 0, objflags); 4759 VM_OBJECT_WUNLOCK(obj); 4760 } 4761 vput(vp); 4762 if (seen_defer) 4763 vdrop(vp); 4764 } else { 4765 if (seen_defer) 4766 vdefer_inactive_unlocked(vp); 4767 } 4768 } 4769 } 4770 4771 void 4772 vfs_periodic(struct mount *mp, int flags) 4773 { 4774 4775 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4776 4777 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4778 vfs_periodic_inactive(mp, flags); 4779 else 4780 vfs_periodic_msync_inactive(mp, flags); 4781 } 4782 4783 static void 4784 destroy_vpollinfo_free(struct vpollinfo *vi) 4785 { 4786 4787 knlist_destroy(&vi->vpi_selinfo.si_note); 4788 mtx_destroy(&vi->vpi_lock); 4789 free(vi, M_VNODEPOLL); 4790 } 4791 4792 static void 4793 destroy_vpollinfo(struct vpollinfo *vi) 4794 { 4795 4796 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4797 seldrain(&vi->vpi_selinfo); 4798 destroy_vpollinfo_free(vi); 4799 } 4800 4801 /* 4802 * Initialize per-vnode helper structure to hold poll-related state. 4803 */ 4804 void 4805 v_addpollinfo(struct vnode *vp) 4806 { 4807 struct vpollinfo *vi; 4808 4809 if (vp->v_pollinfo != NULL) 4810 return; 4811 vi = malloc(sizeof(*vi), M_VNODEPOLL, M_WAITOK | M_ZERO); 4812 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4813 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4814 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4815 VI_LOCK(vp); 4816 if (vp->v_pollinfo != NULL) { 4817 VI_UNLOCK(vp); 4818 destroy_vpollinfo_free(vi); 4819 return; 4820 } 4821 vp->v_pollinfo = vi; 4822 VI_UNLOCK(vp); 4823 } 4824 4825 /* 4826 * Record a process's interest in events which might happen to 4827 * a vnode. Because poll uses the historic select-style interface 4828 * internally, this routine serves as both the ``check for any 4829 * pending events'' and the ``record my interest in future events'' 4830 * functions. (These are done together, while the lock is held, 4831 * to avoid race conditions.) 4832 */ 4833 int 4834 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4835 { 4836 4837 v_addpollinfo(vp); 4838 mtx_lock(&vp->v_pollinfo->vpi_lock); 4839 if (vp->v_pollinfo->vpi_revents & events) { 4840 /* 4841 * This leaves events we are not interested 4842 * in available for the other process which 4843 * which presumably had requested them 4844 * (otherwise they would never have been 4845 * recorded). 4846 */ 4847 events &= vp->v_pollinfo->vpi_revents; 4848 vp->v_pollinfo->vpi_revents &= ~events; 4849 4850 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4851 return (events); 4852 } 4853 vp->v_pollinfo->vpi_events |= events; 4854 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4855 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4856 return (0); 4857 } 4858 4859 /* 4860 * Routine to create and manage a filesystem syncer vnode. 4861 */ 4862 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4863 static int sync_fsync(struct vop_fsync_args *); 4864 static int sync_inactive(struct vop_inactive_args *); 4865 static int sync_reclaim(struct vop_reclaim_args *); 4866 4867 static struct vop_vector sync_vnodeops = { 4868 .vop_bypass = VOP_EOPNOTSUPP, 4869 .vop_close = sync_close, /* close */ 4870 .vop_fsync = sync_fsync, /* fsync */ 4871 .vop_inactive = sync_inactive, /* inactive */ 4872 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 4873 .vop_reclaim = sync_reclaim, /* reclaim */ 4874 .vop_lock1 = vop_stdlock, /* lock */ 4875 .vop_unlock = vop_stdunlock, /* unlock */ 4876 .vop_islocked = vop_stdislocked, /* islocked */ 4877 }; 4878 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 4879 4880 /* 4881 * Create a new filesystem syncer vnode for the specified mount point. 4882 */ 4883 void 4884 vfs_allocate_syncvnode(struct mount *mp) 4885 { 4886 struct vnode *vp; 4887 struct bufobj *bo; 4888 static long start, incr, next; 4889 int error; 4890 4891 /* Allocate a new vnode */ 4892 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4893 if (error != 0) 4894 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4895 vp->v_type = VNON; 4896 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4897 vp->v_vflag |= VV_FORCEINSMQ; 4898 error = insmntque(vp, mp); 4899 if (error != 0) 4900 panic("vfs_allocate_syncvnode: insmntque() failed"); 4901 vp->v_vflag &= ~VV_FORCEINSMQ; 4902 VOP_UNLOCK(vp); 4903 /* 4904 * Place the vnode onto the syncer worklist. We attempt to 4905 * scatter them about on the list so that they will go off 4906 * at evenly distributed times even if all the filesystems 4907 * are mounted at once. 4908 */ 4909 next += incr; 4910 if (next == 0 || next > syncer_maxdelay) { 4911 start /= 2; 4912 incr /= 2; 4913 if (start == 0) { 4914 start = syncer_maxdelay / 2; 4915 incr = syncer_maxdelay; 4916 } 4917 next = start; 4918 } 4919 bo = &vp->v_bufobj; 4920 BO_LOCK(bo); 4921 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4922 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4923 mtx_lock(&sync_mtx); 4924 sync_vnode_count++; 4925 if (mp->mnt_syncer == NULL) { 4926 mp->mnt_syncer = vp; 4927 vp = NULL; 4928 } 4929 mtx_unlock(&sync_mtx); 4930 BO_UNLOCK(bo); 4931 if (vp != NULL) { 4932 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4933 vgone(vp); 4934 vput(vp); 4935 } 4936 } 4937 4938 void 4939 vfs_deallocate_syncvnode(struct mount *mp) 4940 { 4941 struct vnode *vp; 4942 4943 mtx_lock(&sync_mtx); 4944 vp = mp->mnt_syncer; 4945 if (vp != NULL) 4946 mp->mnt_syncer = NULL; 4947 mtx_unlock(&sync_mtx); 4948 if (vp != NULL) 4949 vrele(vp); 4950 } 4951 4952 /* 4953 * Do a lazy sync of the filesystem. 4954 */ 4955 static int 4956 sync_fsync(struct vop_fsync_args *ap) 4957 { 4958 struct vnode *syncvp = ap->a_vp; 4959 struct mount *mp = syncvp->v_mount; 4960 int error, save; 4961 struct bufobj *bo; 4962 4963 /* 4964 * We only need to do something if this is a lazy evaluation. 4965 */ 4966 if (ap->a_waitfor != MNT_LAZY) 4967 return (0); 4968 4969 /* 4970 * Move ourselves to the back of the sync list. 4971 */ 4972 bo = &syncvp->v_bufobj; 4973 BO_LOCK(bo); 4974 vn_syncer_add_to_worklist(bo, syncdelay); 4975 BO_UNLOCK(bo); 4976 4977 /* 4978 * Walk the list of vnodes pushing all that are dirty and 4979 * not already on the sync list. 4980 */ 4981 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4982 return (0); 4983 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4984 vfs_unbusy(mp); 4985 return (0); 4986 } 4987 save = curthread_pflags_set(TDP_SYNCIO); 4988 /* 4989 * The filesystem at hand may be idle with free vnodes stored in the 4990 * batch. Return them instead of letting them stay there indefinitely. 4991 */ 4992 vfs_periodic(mp, MNT_NOWAIT); 4993 error = VFS_SYNC(mp, MNT_LAZY); 4994 curthread_pflags_restore(save); 4995 vn_finished_write(mp); 4996 vfs_unbusy(mp); 4997 return (error); 4998 } 4999 5000 /* 5001 * The syncer vnode is no referenced. 5002 */ 5003 static int 5004 sync_inactive(struct vop_inactive_args *ap) 5005 { 5006 5007 vgone(ap->a_vp); 5008 return (0); 5009 } 5010 5011 /* 5012 * The syncer vnode is no longer needed and is being decommissioned. 5013 * 5014 * Modifications to the worklist must be protected by sync_mtx. 5015 */ 5016 static int 5017 sync_reclaim(struct vop_reclaim_args *ap) 5018 { 5019 struct vnode *vp = ap->a_vp; 5020 struct bufobj *bo; 5021 5022 bo = &vp->v_bufobj; 5023 BO_LOCK(bo); 5024 mtx_lock(&sync_mtx); 5025 if (vp->v_mount->mnt_syncer == vp) 5026 vp->v_mount->mnt_syncer = NULL; 5027 if (bo->bo_flag & BO_ONWORKLST) { 5028 LIST_REMOVE(bo, bo_synclist); 5029 syncer_worklist_len--; 5030 sync_vnode_count--; 5031 bo->bo_flag &= ~BO_ONWORKLST; 5032 } 5033 mtx_unlock(&sync_mtx); 5034 BO_UNLOCK(bo); 5035 5036 return (0); 5037 } 5038 5039 int 5040 vn_need_pageq_flush(struct vnode *vp) 5041 { 5042 struct vm_object *obj; 5043 int need; 5044 5045 MPASS(mtx_owned(VI_MTX(vp))); 5046 need = 0; 5047 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5048 vm_object_mightbedirty(obj)) 5049 need = 1; 5050 return (need); 5051 } 5052 5053 /* 5054 * Check if vnode represents a disk device 5055 */ 5056 bool 5057 vn_isdisk_error(struct vnode *vp, int *errp) 5058 { 5059 int error; 5060 5061 if (vp->v_type != VCHR) { 5062 error = ENOTBLK; 5063 goto out; 5064 } 5065 error = 0; 5066 dev_lock(); 5067 if (vp->v_rdev == NULL) 5068 error = ENXIO; 5069 else if (vp->v_rdev->si_devsw == NULL) 5070 error = ENXIO; 5071 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5072 error = ENOTBLK; 5073 dev_unlock(); 5074 out: 5075 *errp = error; 5076 return (error == 0); 5077 } 5078 5079 bool 5080 vn_isdisk(struct vnode *vp) 5081 { 5082 int error; 5083 5084 return (vn_isdisk_error(vp, &error)); 5085 } 5086 5087 /* 5088 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see 5089 * the comment above cache_fplookup for details. 5090 */ 5091 int 5092 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred) 5093 { 5094 int error; 5095 5096 VFS_SMR_ASSERT_ENTERED(); 5097 5098 /* Check the owner. */ 5099 if (cred->cr_uid == file_uid) { 5100 if (file_mode & S_IXUSR) 5101 return (0); 5102 goto out_error; 5103 } 5104 5105 /* Otherwise, check the groups (first match) */ 5106 if (groupmember(file_gid, cred)) { 5107 if (file_mode & S_IXGRP) 5108 return (0); 5109 goto out_error; 5110 } 5111 5112 /* Otherwise, check everyone else. */ 5113 if (file_mode & S_IXOTH) 5114 return (0); 5115 out_error: 5116 /* 5117 * Permission check failed, but it is possible denial will get overwritten 5118 * (e.g., when root is traversing through a 700 directory owned by someone 5119 * else). 5120 * 5121 * vaccess() calls priv_check_cred which in turn can descent into MAC 5122 * modules overriding this result. It's quite unclear what semantics 5123 * are allowed for them to operate, thus for safety we don't call them 5124 * from within the SMR section. This also means if any such modules 5125 * are present, we have to let the regular lookup decide. 5126 */ 5127 error = priv_check_cred_vfs_lookup_nomac(cred); 5128 switch (error) { 5129 case 0: 5130 return (0); 5131 case EAGAIN: 5132 /* 5133 * MAC modules present. 5134 */ 5135 return (EAGAIN); 5136 case EPERM: 5137 return (EACCES); 5138 default: 5139 return (error); 5140 } 5141 } 5142 5143 /* 5144 * Common filesystem object access control check routine. Accepts a 5145 * vnode's type, "mode", uid and gid, requested access mode, and credentials. 5146 * Returns 0 on success, or an errno on failure. 5147 */ 5148 int 5149 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5150 accmode_t accmode, struct ucred *cred) 5151 { 5152 accmode_t dac_granted; 5153 accmode_t priv_granted; 5154 5155 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5156 ("invalid bit in accmode")); 5157 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5158 ("VAPPEND without VWRITE")); 5159 5160 /* 5161 * Look for a normal, non-privileged way to access the file/directory 5162 * as requested. If it exists, go with that. 5163 */ 5164 5165 dac_granted = 0; 5166 5167 /* Check the owner. */ 5168 if (cred->cr_uid == file_uid) { 5169 dac_granted |= VADMIN; 5170 if (file_mode & S_IXUSR) 5171 dac_granted |= VEXEC; 5172 if (file_mode & S_IRUSR) 5173 dac_granted |= VREAD; 5174 if (file_mode & S_IWUSR) 5175 dac_granted |= (VWRITE | VAPPEND); 5176 5177 if ((accmode & dac_granted) == accmode) 5178 return (0); 5179 5180 goto privcheck; 5181 } 5182 5183 /* Otherwise, check the groups (first match) */ 5184 if (groupmember(file_gid, cred)) { 5185 if (file_mode & S_IXGRP) 5186 dac_granted |= VEXEC; 5187 if (file_mode & S_IRGRP) 5188 dac_granted |= VREAD; 5189 if (file_mode & S_IWGRP) 5190 dac_granted |= (VWRITE | VAPPEND); 5191 5192 if ((accmode & dac_granted) == accmode) 5193 return (0); 5194 5195 goto privcheck; 5196 } 5197 5198 /* Otherwise, check everyone else. */ 5199 if (file_mode & S_IXOTH) 5200 dac_granted |= VEXEC; 5201 if (file_mode & S_IROTH) 5202 dac_granted |= VREAD; 5203 if (file_mode & S_IWOTH) 5204 dac_granted |= (VWRITE | VAPPEND); 5205 if ((accmode & dac_granted) == accmode) 5206 return (0); 5207 5208 privcheck: 5209 /* 5210 * Build a privilege mask to determine if the set of privileges 5211 * satisfies the requirements when combined with the granted mask 5212 * from above. For each privilege, if the privilege is required, 5213 * bitwise or the request type onto the priv_granted mask. 5214 */ 5215 priv_granted = 0; 5216 5217 if (type == VDIR) { 5218 /* 5219 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5220 * requests, instead of PRIV_VFS_EXEC. 5221 */ 5222 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5223 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5224 priv_granted |= VEXEC; 5225 } else { 5226 /* 5227 * Ensure that at least one execute bit is on. Otherwise, 5228 * a privileged user will always succeed, and we don't want 5229 * this to happen unless the file really is executable. 5230 */ 5231 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5232 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5233 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5234 priv_granted |= VEXEC; 5235 } 5236 5237 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5238 !priv_check_cred(cred, PRIV_VFS_READ)) 5239 priv_granted |= VREAD; 5240 5241 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5242 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5243 priv_granted |= (VWRITE | VAPPEND); 5244 5245 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5246 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5247 priv_granted |= VADMIN; 5248 5249 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5250 return (0); 5251 } 5252 5253 return ((accmode & VADMIN) ? EPERM : EACCES); 5254 } 5255 5256 /* 5257 * Credential check based on process requesting service, and per-attribute 5258 * permissions. 5259 */ 5260 int 5261 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5262 struct thread *td, accmode_t accmode) 5263 { 5264 5265 /* 5266 * Kernel-invoked always succeeds. 5267 */ 5268 if (cred == NOCRED) 5269 return (0); 5270 5271 /* 5272 * Do not allow privileged processes in jail to directly manipulate 5273 * system attributes. 5274 */ 5275 switch (attrnamespace) { 5276 case EXTATTR_NAMESPACE_SYSTEM: 5277 /* Potentially should be: return (EPERM); */ 5278 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5279 case EXTATTR_NAMESPACE_USER: 5280 return (VOP_ACCESS(vp, accmode, cred, td)); 5281 default: 5282 return (EPERM); 5283 } 5284 } 5285 5286 #ifdef DEBUG_VFS_LOCKS 5287 /* 5288 * This only exists to suppress warnings from unlocked specfs accesses. It is 5289 * no longer ok to have an unlocked VFS. 5290 */ 5291 #define IGNORE_LOCK(vp) (KERNEL_PANICKED() || (vp) == NULL || \ 5292 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 5293 5294 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5295 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5296 "Drop into debugger on lock violation"); 5297 5298 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5299 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5300 0, "Check for interlock across VOPs"); 5301 5302 int vfs_badlock_print = 1; /* Print lock violations. */ 5303 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5304 0, "Print lock violations"); 5305 5306 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5307 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5308 0, "Print vnode details on lock violations"); 5309 5310 #ifdef KDB 5311 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5312 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5313 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5314 #endif 5315 5316 static void 5317 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5318 { 5319 5320 #ifdef KDB 5321 if (vfs_badlock_backtrace) 5322 kdb_backtrace(); 5323 #endif 5324 if (vfs_badlock_vnode) 5325 vn_printf(vp, "vnode "); 5326 if (vfs_badlock_print) 5327 printf("%s: %p %s\n", str, (void *)vp, msg); 5328 if (vfs_badlock_ddb) 5329 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5330 } 5331 5332 void 5333 assert_vi_locked(struct vnode *vp, const char *str) 5334 { 5335 5336 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5337 vfs_badlock("interlock is not locked but should be", str, vp); 5338 } 5339 5340 void 5341 assert_vi_unlocked(struct vnode *vp, const char *str) 5342 { 5343 5344 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5345 vfs_badlock("interlock is locked but should not be", str, vp); 5346 } 5347 5348 void 5349 assert_vop_locked(struct vnode *vp, const char *str) 5350 { 5351 int locked; 5352 5353 if (!IGNORE_LOCK(vp)) { 5354 locked = VOP_ISLOCKED(vp); 5355 if (locked == 0 || locked == LK_EXCLOTHER) 5356 vfs_badlock("is not locked but should be", str, vp); 5357 } 5358 } 5359 5360 void 5361 assert_vop_unlocked(struct vnode *vp, const char *str) 5362 { 5363 5364 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5365 vfs_badlock("is locked but should not be", str, vp); 5366 } 5367 5368 void 5369 assert_vop_elocked(struct vnode *vp, const char *str) 5370 { 5371 5372 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5373 vfs_badlock("is not exclusive locked but should be", str, vp); 5374 } 5375 #endif /* DEBUG_VFS_LOCKS */ 5376 5377 void 5378 vop_rename_fail(struct vop_rename_args *ap) 5379 { 5380 5381 if (ap->a_tvp != NULL) 5382 vput(ap->a_tvp); 5383 if (ap->a_tdvp == ap->a_tvp) 5384 vrele(ap->a_tdvp); 5385 else 5386 vput(ap->a_tdvp); 5387 vrele(ap->a_fdvp); 5388 vrele(ap->a_fvp); 5389 } 5390 5391 void 5392 vop_rename_pre(void *ap) 5393 { 5394 struct vop_rename_args *a = ap; 5395 5396 #ifdef DEBUG_VFS_LOCKS 5397 if (a->a_tvp) 5398 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5399 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5400 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5401 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5402 5403 /* Check the source (from). */ 5404 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5405 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5406 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5407 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5408 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5409 5410 /* Check the target. */ 5411 if (a->a_tvp) 5412 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5413 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5414 #endif 5415 /* 5416 * It may be tempting to add vn_seqc_write_begin/end calls here and 5417 * in vop_rename_post but that's not going to work out since some 5418 * filesystems relookup vnodes mid-rename. This is probably a bug. 5419 * 5420 * For now filesystems are expected to do the relevant calls after they 5421 * decide what vnodes to operate on. 5422 */ 5423 if (a->a_tdvp != a->a_fdvp) 5424 vhold(a->a_fdvp); 5425 if (a->a_tvp != a->a_fvp) 5426 vhold(a->a_fvp); 5427 vhold(a->a_tdvp); 5428 if (a->a_tvp) 5429 vhold(a->a_tvp); 5430 } 5431 5432 #ifdef DEBUG_VFS_LOCKS 5433 void 5434 vop_fplookup_vexec_debugpre(void *ap __unused) 5435 { 5436 5437 VFS_SMR_ASSERT_ENTERED(); 5438 } 5439 5440 void 5441 vop_fplookup_vexec_debugpost(void *ap __unused, int rc __unused) 5442 { 5443 5444 VFS_SMR_ASSERT_ENTERED(); 5445 } 5446 5447 void 5448 vop_strategy_debugpre(void *ap) 5449 { 5450 struct vop_strategy_args *a; 5451 struct buf *bp; 5452 5453 a = ap; 5454 bp = a->a_bp; 5455 5456 /* 5457 * Cluster ops lock their component buffers but not the IO container. 5458 */ 5459 if ((bp->b_flags & B_CLUSTER) != 0) 5460 return; 5461 5462 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5463 if (vfs_badlock_print) 5464 printf( 5465 "VOP_STRATEGY: bp is not locked but should be\n"); 5466 if (vfs_badlock_ddb) 5467 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5468 } 5469 } 5470 5471 void 5472 vop_lock_debugpre(void *ap) 5473 { 5474 struct vop_lock1_args *a = ap; 5475 5476 if ((a->a_flags & LK_INTERLOCK) == 0) 5477 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5478 else 5479 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5480 } 5481 5482 void 5483 vop_lock_debugpost(void *ap, int rc) 5484 { 5485 struct vop_lock1_args *a = ap; 5486 5487 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5488 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5489 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5490 } 5491 5492 void 5493 vop_unlock_debugpre(void *ap) 5494 { 5495 struct vop_unlock_args *a = ap; 5496 5497 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5498 } 5499 5500 void 5501 vop_need_inactive_debugpre(void *ap) 5502 { 5503 struct vop_need_inactive_args *a = ap; 5504 5505 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5506 } 5507 5508 void 5509 vop_need_inactive_debugpost(void *ap, int rc) 5510 { 5511 struct vop_need_inactive_args *a = ap; 5512 5513 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5514 } 5515 #endif 5516 5517 void 5518 vop_create_pre(void *ap) 5519 { 5520 struct vop_create_args *a; 5521 struct vnode *dvp; 5522 5523 a = ap; 5524 dvp = a->a_dvp; 5525 vn_seqc_write_begin(dvp); 5526 } 5527 5528 void 5529 vop_create_post(void *ap, int rc) 5530 { 5531 struct vop_create_args *a; 5532 struct vnode *dvp; 5533 5534 a = ap; 5535 dvp = a->a_dvp; 5536 vn_seqc_write_end(dvp); 5537 if (!rc) 5538 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5539 } 5540 5541 void 5542 vop_whiteout_pre(void *ap) 5543 { 5544 struct vop_whiteout_args *a; 5545 struct vnode *dvp; 5546 5547 a = ap; 5548 dvp = a->a_dvp; 5549 vn_seqc_write_begin(dvp); 5550 } 5551 5552 void 5553 vop_whiteout_post(void *ap, int rc) 5554 { 5555 struct vop_whiteout_args *a; 5556 struct vnode *dvp; 5557 5558 a = ap; 5559 dvp = a->a_dvp; 5560 vn_seqc_write_end(dvp); 5561 } 5562 5563 void 5564 vop_deleteextattr_pre(void *ap) 5565 { 5566 struct vop_deleteextattr_args *a; 5567 struct vnode *vp; 5568 5569 a = ap; 5570 vp = a->a_vp; 5571 vn_seqc_write_begin(vp); 5572 } 5573 5574 void 5575 vop_deleteextattr_post(void *ap, int rc) 5576 { 5577 struct vop_deleteextattr_args *a; 5578 struct vnode *vp; 5579 5580 a = ap; 5581 vp = a->a_vp; 5582 vn_seqc_write_end(vp); 5583 if (!rc) 5584 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5585 } 5586 5587 void 5588 vop_link_pre(void *ap) 5589 { 5590 struct vop_link_args *a; 5591 struct vnode *vp, *tdvp; 5592 5593 a = ap; 5594 vp = a->a_vp; 5595 tdvp = a->a_tdvp; 5596 vn_seqc_write_begin(vp); 5597 vn_seqc_write_begin(tdvp); 5598 } 5599 5600 void 5601 vop_link_post(void *ap, int rc) 5602 { 5603 struct vop_link_args *a; 5604 struct vnode *vp, *tdvp; 5605 5606 a = ap; 5607 vp = a->a_vp; 5608 tdvp = a->a_tdvp; 5609 vn_seqc_write_end(vp); 5610 vn_seqc_write_end(tdvp); 5611 if (!rc) { 5612 VFS_KNOTE_LOCKED(vp, NOTE_LINK); 5613 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE); 5614 } 5615 } 5616 5617 void 5618 vop_mkdir_pre(void *ap) 5619 { 5620 struct vop_mkdir_args *a; 5621 struct vnode *dvp; 5622 5623 a = ap; 5624 dvp = a->a_dvp; 5625 vn_seqc_write_begin(dvp); 5626 } 5627 5628 void 5629 vop_mkdir_post(void *ap, int rc) 5630 { 5631 struct vop_mkdir_args *a; 5632 struct vnode *dvp; 5633 5634 a = ap; 5635 dvp = a->a_dvp; 5636 vn_seqc_write_end(dvp); 5637 if (!rc) 5638 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 5639 } 5640 5641 #ifdef DEBUG_VFS_LOCKS 5642 void 5643 vop_mkdir_debugpost(void *ap, int rc) 5644 { 5645 struct vop_mkdir_args *a; 5646 5647 a = ap; 5648 if (!rc) 5649 cache_validate(a->a_dvp, *a->a_vpp, a->a_cnp); 5650 } 5651 #endif 5652 5653 void 5654 vop_mknod_pre(void *ap) 5655 { 5656 struct vop_mknod_args *a; 5657 struct vnode *dvp; 5658 5659 a = ap; 5660 dvp = a->a_dvp; 5661 vn_seqc_write_begin(dvp); 5662 } 5663 5664 void 5665 vop_mknod_post(void *ap, int rc) 5666 { 5667 struct vop_mknod_args *a; 5668 struct vnode *dvp; 5669 5670 a = ap; 5671 dvp = a->a_dvp; 5672 vn_seqc_write_end(dvp); 5673 if (!rc) 5674 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5675 } 5676 5677 void 5678 vop_reclaim_post(void *ap, int rc) 5679 { 5680 struct vop_reclaim_args *a; 5681 struct vnode *vp; 5682 5683 a = ap; 5684 vp = a->a_vp; 5685 ASSERT_VOP_IN_SEQC(vp); 5686 if (!rc) 5687 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE); 5688 } 5689 5690 void 5691 vop_remove_pre(void *ap) 5692 { 5693 struct vop_remove_args *a; 5694 struct vnode *dvp, *vp; 5695 5696 a = ap; 5697 dvp = a->a_dvp; 5698 vp = a->a_vp; 5699 vn_seqc_write_begin(dvp); 5700 vn_seqc_write_begin(vp); 5701 } 5702 5703 void 5704 vop_remove_post(void *ap, int rc) 5705 { 5706 struct vop_remove_args *a; 5707 struct vnode *dvp, *vp; 5708 5709 a = ap; 5710 dvp = a->a_dvp; 5711 vp = a->a_vp; 5712 vn_seqc_write_end(dvp); 5713 vn_seqc_write_end(vp); 5714 if (!rc) { 5715 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5716 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 5717 } 5718 } 5719 5720 void 5721 vop_rename_post(void *ap, int rc) 5722 { 5723 struct vop_rename_args *a = ap; 5724 long hint; 5725 5726 if (!rc) { 5727 hint = NOTE_WRITE; 5728 if (a->a_fdvp == a->a_tdvp) { 5729 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5730 hint |= NOTE_LINK; 5731 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5732 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5733 } else { 5734 hint |= NOTE_EXTEND; 5735 if (a->a_fvp->v_type == VDIR) 5736 hint |= NOTE_LINK; 5737 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5738 5739 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5740 a->a_tvp->v_type == VDIR) 5741 hint &= ~NOTE_LINK; 5742 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5743 } 5744 5745 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5746 if (a->a_tvp) 5747 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5748 } 5749 if (a->a_tdvp != a->a_fdvp) 5750 vdrop(a->a_fdvp); 5751 if (a->a_tvp != a->a_fvp) 5752 vdrop(a->a_fvp); 5753 vdrop(a->a_tdvp); 5754 if (a->a_tvp) 5755 vdrop(a->a_tvp); 5756 } 5757 5758 void 5759 vop_rmdir_pre(void *ap) 5760 { 5761 struct vop_rmdir_args *a; 5762 struct vnode *dvp, *vp; 5763 5764 a = ap; 5765 dvp = a->a_dvp; 5766 vp = a->a_vp; 5767 vn_seqc_write_begin(dvp); 5768 vn_seqc_write_begin(vp); 5769 } 5770 5771 void 5772 vop_rmdir_post(void *ap, int rc) 5773 { 5774 struct vop_rmdir_args *a; 5775 struct vnode *dvp, *vp; 5776 5777 a = ap; 5778 dvp = a->a_dvp; 5779 vp = a->a_vp; 5780 vn_seqc_write_end(dvp); 5781 vn_seqc_write_end(vp); 5782 if (!rc) { 5783 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 5784 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 5785 } 5786 } 5787 5788 void 5789 vop_setattr_pre(void *ap) 5790 { 5791 struct vop_setattr_args *a; 5792 struct vnode *vp; 5793 5794 a = ap; 5795 vp = a->a_vp; 5796 vn_seqc_write_begin(vp); 5797 } 5798 5799 void 5800 vop_setattr_post(void *ap, int rc) 5801 { 5802 struct vop_setattr_args *a; 5803 struct vnode *vp; 5804 5805 a = ap; 5806 vp = a->a_vp; 5807 vn_seqc_write_end(vp); 5808 if (!rc) 5809 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 5810 } 5811 5812 void 5813 vop_setacl_pre(void *ap) 5814 { 5815 struct vop_setacl_args *a; 5816 struct vnode *vp; 5817 5818 a = ap; 5819 vp = a->a_vp; 5820 vn_seqc_write_begin(vp); 5821 } 5822 5823 void 5824 vop_setacl_post(void *ap, int rc __unused) 5825 { 5826 struct vop_setacl_args *a; 5827 struct vnode *vp; 5828 5829 a = ap; 5830 vp = a->a_vp; 5831 vn_seqc_write_end(vp); 5832 } 5833 5834 void 5835 vop_setextattr_pre(void *ap) 5836 { 5837 struct vop_setextattr_args *a; 5838 struct vnode *vp; 5839 5840 a = ap; 5841 vp = a->a_vp; 5842 vn_seqc_write_begin(vp); 5843 } 5844 5845 void 5846 vop_setextattr_post(void *ap, int rc) 5847 { 5848 struct vop_setextattr_args *a; 5849 struct vnode *vp; 5850 5851 a = ap; 5852 vp = a->a_vp; 5853 vn_seqc_write_end(vp); 5854 if (!rc) 5855 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 5856 } 5857 5858 void 5859 vop_symlink_pre(void *ap) 5860 { 5861 struct vop_symlink_args *a; 5862 struct vnode *dvp; 5863 5864 a = ap; 5865 dvp = a->a_dvp; 5866 vn_seqc_write_begin(dvp); 5867 } 5868 5869 void 5870 vop_symlink_post(void *ap, int rc) 5871 { 5872 struct vop_symlink_args *a; 5873 struct vnode *dvp; 5874 5875 a = ap; 5876 dvp = a->a_dvp; 5877 vn_seqc_write_end(dvp); 5878 if (!rc) 5879 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5880 } 5881 5882 void 5883 vop_open_post(void *ap, int rc) 5884 { 5885 struct vop_open_args *a = ap; 5886 5887 if (!rc) 5888 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5889 } 5890 5891 void 5892 vop_close_post(void *ap, int rc) 5893 { 5894 struct vop_close_args *a = ap; 5895 5896 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5897 !VN_IS_DOOMED(a->a_vp))) { 5898 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5899 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5900 } 5901 } 5902 5903 void 5904 vop_read_post(void *ap, int rc) 5905 { 5906 struct vop_read_args *a = ap; 5907 5908 if (!rc) 5909 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5910 } 5911 5912 void 5913 vop_read_pgcache_post(void *ap, int rc) 5914 { 5915 struct vop_read_pgcache_args *a = ap; 5916 5917 if (!rc) 5918 VFS_KNOTE_UNLOCKED(a->a_vp, NOTE_READ); 5919 } 5920 5921 void 5922 vop_readdir_post(void *ap, int rc) 5923 { 5924 struct vop_readdir_args *a = ap; 5925 5926 if (!rc) 5927 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5928 } 5929 5930 static struct knlist fs_knlist; 5931 5932 static void 5933 vfs_event_init(void *arg) 5934 { 5935 knlist_init_mtx(&fs_knlist, NULL); 5936 } 5937 /* XXX - correct order? */ 5938 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5939 5940 void 5941 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5942 { 5943 5944 KNOTE_UNLOCKED(&fs_knlist, event); 5945 } 5946 5947 static int filt_fsattach(struct knote *kn); 5948 static void filt_fsdetach(struct knote *kn); 5949 static int filt_fsevent(struct knote *kn, long hint); 5950 5951 struct filterops fs_filtops = { 5952 .f_isfd = 0, 5953 .f_attach = filt_fsattach, 5954 .f_detach = filt_fsdetach, 5955 .f_event = filt_fsevent 5956 }; 5957 5958 static int 5959 filt_fsattach(struct knote *kn) 5960 { 5961 5962 kn->kn_flags |= EV_CLEAR; 5963 knlist_add(&fs_knlist, kn, 0); 5964 return (0); 5965 } 5966 5967 static void 5968 filt_fsdetach(struct knote *kn) 5969 { 5970 5971 knlist_remove(&fs_knlist, kn, 0); 5972 } 5973 5974 static int 5975 filt_fsevent(struct knote *kn, long hint) 5976 { 5977 5978 kn->kn_fflags |= hint; 5979 return (kn->kn_fflags != 0); 5980 } 5981 5982 static int 5983 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5984 { 5985 struct vfsidctl vc; 5986 int error; 5987 struct mount *mp; 5988 5989 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5990 if (error) 5991 return (error); 5992 if (vc.vc_vers != VFS_CTL_VERS1) 5993 return (EINVAL); 5994 mp = vfs_getvfs(&vc.vc_fsid); 5995 if (mp == NULL) 5996 return (ENOENT); 5997 /* ensure that a specific sysctl goes to the right filesystem. */ 5998 if (strcmp(vc.vc_fstypename, "*") != 0 && 5999 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 6000 vfs_rel(mp); 6001 return (EINVAL); 6002 } 6003 VCTLTOREQ(&vc, req); 6004 error = VFS_SYSCTL(mp, vc.vc_op, req); 6005 vfs_rel(mp); 6006 return (error); 6007 } 6008 6009 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 6010 NULL, 0, sysctl_vfs_ctl, "", 6011 "Sysctl by fsid"); 6012 6013 /* 6014 * Function to initialize a va_filerev field sensibly. 6015 * XXX: Wouldn't a random number make a lot more sense ?? 6016 */ 6017 u_quad_t 6018 init_va_filerev(void) 6019 { 6020 struct bintime bt; 6021 6022 getbinuptime(&bt); 6023 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 6024 } 6025 6026 static int filt_vfsread(struct knote *kn, long hint); 6027 static int filt_vfswrite(struct knote *kn, long hint); 6028 static int filt_vfsvnode(struct knote *kn, long hint); 6029 static void filt_vfsdetach(struct knote *kn); 6030 static struct filterops vfsread_filtops = { 6031 .f_isfd = 1, 6032 .f_detach = filt_vfsdetach, 6033 .f_event = filt_vfsread 6034 }; 6035 static struct filterops vfswrite_filtops = { 6036 .f_isfd = 1, 6037 .f_detach = filt_vfsdetach, 6038 .f_event = filt_vfswrite 6039 }; 6040 static struct filterops vfsvnode_filtops = { 6041 .f_isfd = 1, 6042 .f_detach = filt_vfsdetach, 6043 .f_event = filt_vfsvnode 6044 }; 6045 6046 static void 6047 vfs_knllock(void *arg) 6048 { 6049 struct vnode *vp = arg; 6050 6051 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 6052 } 6053 6054 static void 6055 vfs_knlunlock(void *arg) 6056 { 6057 struct vnode *vp = arg; 6058 6059 VOP_UNLOCK(vp); 6060 } 6061 6062 static void 6063 vfs_knl_assert_locked(void *arg) 6064 { 6065 #ifdef DEBUG_VFS_LOCKS 6066 struct vnode *vp = arg; 6067 6068 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 6069 #endif 6070 } 6071 6072 static void 6073 vfs_knl_assert_unlocked(void *arg) 6074 { 6075 #ifdef DEBUG_VFS_LOCKS 6076 struct vnode *vp = arg; 6077 6078 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 6079 #endif 6080 } 6081 6082 int 6083 vfs_kqfilter(struct vop_kqfilter_args *ap) 6084 { 6085 struct vnode *vp = ap->a_vp; 6086 struct knote *kn = ap->a_kn; 6087 struct knlist *knl; 6088 6089 switch (kn->kn_filter) { 6090 case EVFILT_READ: 6091 kn->kn_fop = &vfsread_filtops; 6092 break; 6093 case EVFILT_WRITE: 6094 kn->kn_fop = &vfswrite_filtops; 6095 break; 6096 case EVFILT_VNODE: 6097 kn->kn_fop = &vfsvnode_filtops; 6098 break; 6099 default: 6100 return (EINVAL); 6101 } 6102 6103 kn->kn_hook = (caddr_t)vp; 6104 6105 v_addpollinfo(vp); 6106 if (vp->v_pollinfo == NULL) 6107 return (ENOMEM); 6108 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 6109 vhold(vp); 6110 knlist_add(knl, kn, 0); 6111 6112 return (0); 6113 } 6114 6115 /* 6116 * Detach knote from vnode 6117 */ 6118 static void 6119 filt_vfsdetach(struct knote *kn) 6120 { 6121 struct vnode *vp = (struct vnode *)kn->kn_hook; 6122 6123 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 6124 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 6125 vdrop(vp); 6126 } 6127 6128 /*ARGSUSED*/ 6129 static int 6130 filt_vfsread(struct knote *kn, long hint) 6131 { 6132 struct vnode *vp = (struct vnode *)kn->kn_hook; 6133 struct vattr va; 6134 int res; 6135 6136 /* 6137 * filesystem is gone, so set the EOF flag and schedule 6138 * the knote for deletion. 6139 */ 6140 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6141 VI_LOCK(vp); 6142 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6143 VI_UNLOCK(vp); 6144 return (1); 6145 } 6146 6147 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 6148 return (0); 6149 6150 VI_LOCK(vp); 6151 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 6152 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 6153 VI_UNLOCK(vp); 6154 return (res); 6155 } 6156 6157 /*ARGSUSED*/ 6158 static int 6159 filt_vfswrite(struct knote *kn, long hint) 6160 { 6161 struct vnode *vp = (struct vnode *)kn->kn_hook; 6162 6163 VI_LOCK(vp); 6164 6165 /* 6166 * filesystem is gone, so set the EOF flag and schedule 6167 * the knote for deletion. 6168 */ 6169 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 6170 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6171 6172 kn->kn_data = 0; 6173 VI_UNLOCK(vp); 6174 return (1); 6175 } 6176 6177 static int 6178 filt_vfsvnode(struct knote *kn, long hint) 6179 { 6180 struct vnode *vp = (struct vnode *)kn->kn_hook; 6181 int res; 6182 6183 VI_LOCK(vp); 6184 if (kn->kn_sfflags & hint) 6185 kn->kn_fflags |= hint; 6186 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6187 kn->kn_flags |= EV_EOF; 6188 VI_UNLOCK(vp); 6189 return (1); 6190 } 6191 res = (kn->kn_fflags != 0); 6192 VI_UNLOCK(vp); 6193 return (res); 6194 } 6195 6196 /* 6197 * Returns whether the directory is empty or not. 6198 * If it is empty, the return value is 0; otherwise 6199 * the return value is an error value (which may 6200 * be ENOTEMPTY). 6201 */ 6202 int 6203 vfs_emptydir(struct vnode *vp) 6204 { 6205 struct uio uio; 6206 struct iovec iov; 6207 struct dirent *dirent, *dp, *endp; 6208 int error, eof; 6209 6210 error = 0; 6211 eof = 0; 6212 6213 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 6214 6215 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 6216 iov.iov_base = dirent; 6217 iov.iov_len = sizeof(struct dirent); 6218 6219 uio.uio_iov = &iov; 6220 uio.uio_iovcnt = 1; 6221 uio.uio_offset = 0; 6222 uio.uio_resid = sizeof(struct dirent); 6223 uio.uio_segflg = UIO_SYSSPACE; 6224 uio.uio_rw = UIO_READ; 6225 uio.uio_td = curthread; 6226 6227 while (eof == 0 && error == 0) { 6228 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 6229 NULL, NULL); 6230 if (error != 0) 6231 break; 6232 endp = (void *)((uint8_t *)dirent + 6233 sizeof(struct dirent) - uio.uio_resid); 6234 for (dp = dirent; dp < endp; 6235 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 6236 if (dp->d_type == DT_WHT) 6237 continue; 6238 if (dp->d_namlen == 0) 6239 continue; 6240 if (dp->d_type != DT_DIR && 6241 dp->d_type != DT_UNKNOWN) { 6242 error = ENOTEMPTY; 6243 break; 6244 } 6245 if (dp->d_namlen > 2) { 6246 error = ENOTEMPTY; 6247 break; 6248 } 6249 if (dp->d_namlen == 1 && 6250 dp->d_name[0] != '.') { 6251 error = ENOTEMPTY; 6252 break; 6253 } 6254 if (dp->d_namlen == 2 && 6255 dp->d_name[1] != '.') { 6256 error = ENOTEMPTY; 6257 break; 6258 } 6259 uio.uio_resid = sizeof(struct dirent); 6260 } 6261 } 6262 free(dirent, M_TEMP); 6263 return (error); 6264 } 6265 6266 int 6267 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 6268 { 6269 int error; 6270 6271 if (dp->d_reclen > ap->a_uio->uio_resid) 6272 return (ENAMETOOLONG); 6273 error = uiomove(dp, dp->d_reclen, ap->a_uio); 6274 if (error) { 6275 if (ap->a_ncookies != NULL) { 6276 if (ap->a_cookies != NULL) 6277 free(ap->a_cookies, M_TEMP); 6278 ap->a_cookies = NULL; 6279 *ap->a_ncookies = 0; 6280 } 6281 return (error); 6282 } 6283 if (ap->a_ncookies == NULL) 6284 return (0); 6285 6286 KASSERT(ap->a_cookies, 6287 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 6288 6289 *ap->a_cookies = realloc(*ap->a_cookies, 6290 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 6291 (*ap->a_cookies)[*ap->a_ncookies] = off; 6292 *ap->a_ncookies += 1; 6293 return (0); 6294 } 6295 6296 /* 6297 * The purpose of this routine is to remove granularity from accmode_t, 6298 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 6299 * VADMIN and VAPPEND. 6300 * 6301 * If it returns 0, the caller is supposed to continue with the usual 6302 * access checks using 'accmode' as modified by this routine. If it 6303 * returns nonzero value, the caller is supposed to return that value 6304 * as errno. 6305 * 6306 * Note that after this routine runs, accmode may be zero. 6307 */ 6308 int 6309 vfs_unixify_accmode(accmode_t *accmode) 6310 { 6311 /* 6312 * There is no way to specify explicit "deny" rule using 6313 * file mode or POSIX.1e ACLs. 6314 */ 6315 if (*accmode & VEXPLICIT_DENY) { 6316 *accmode = 0; 6317 return (0); 6318 } 6319 6320 /* 6321 * None of these can be translated into usual access bits. 6322 * Also, the common case for NFSv4 ACLs is to not contain 6323 * either of these bits. Caller should check for VWRITE 6324 * on the containing directory instead. 6325 */ 6326 if (*accmode & (VDELETE_CHILD | VDELETE)) 6327 return (EPERM); 6328 6329 if (*accmode & VADMIN_PERMS) { 6330 *accmode &= ~VADMIN_PERMS; 6331 *accmode |= VADMIN; 6332 } 6333 6334 /* 6335 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6336 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6337 */ 6338 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6339 6340 return (0); 6341 } 6342 6343 /* 6344 * Clear out a doomed vnode (if any) and replace it with a new one as long 6345 * as the fs is not being unmounted. Return the root vnode to the caller. 6346 */ 6347 static int __noinline 6348 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6349 { 6350 struct vnode *vp; 6351 int error; 6352 6353 restart: 6354 if (mp->mnt_rootvnode != NULL) { 6355 MNT_ILOCK(mp); 6356 vp = mp->mnt_rootvnode; 6357 if (vp != NULL) { 6358 if (!VN_IS_DOOMED(vp)) { 6359 vrefact(vp); 6360 MNT_IUNLOCK(mp); 6361 error = vn_lock(vp, flags); 6362 if (error == 0) { 6363 *vpp = vp; 6364 return (0); 6365 } 6366 vrele(vp); 6367 goto restart; 6368 } 6369 /* 6370 * Clear the old one. 6371 */ 6372 mp->mnt_rootvnode = NULL; 6373 } 6374 MNT_IUNLOCK(mp); 6375 if (vp != NULL) { 6376 vfs_op_barrier_wait(mp); 6377 vrele(vp); 6378 } 6379 } 6380 error = VFS_CACHEDROOT(mp, flags, vpp); 6381 if (error != 0) 6382 return (error); 6383 if (mp->mnt_vfs_ops == 0) { 6384 MNT_ILOCK(mp); 6385 if (mp->mnt_vfs_ops != 0) { 6386 MNT_IUNLOCK(mp); 6387 return (0); 6388 } 6389 if (mp->mnt_rootvnode == NULL) { 6390 vrefact(*vpp); 6391 mp->mnt_rootvnode = *vpp; 6392 } else { 6393 if (mp->mnt_rootvnode != *vpp) { 6394 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6395 panic("%s: mismatch between vnode returned " 6396 " by VFS_CACHEDROOT and the one cached " 6397 " (%p != %p)", 6398 __func__, *vpp, mp->mnt_rootvnode); 6399 } 6400 } 6401 } 6402 MNT_IUNLOCK(mp); 6403 } 6404 return (0); 6405 } 6406 6407 int 6408 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6409 { 6410 struct vnode *vp; 6411 int error; 6412 6413 if (!vfs_op_thread_enter(mp)) 6414 return (vfs_cache_root_fallback(mp, flags, vpp)); 6415 vp = atomic_load_ptr(&mp->mnt_rootvnode); 6416 if (vp == NULL || VN_IS_DOOMED(vp)) { 6417 vfs_op_thread_exit(mp); 6418 return (vfs_cache_root_fallback(mp, flags, vpp)); 6419 } 6420 vrefact(vp); 6421 vfs_op_thread_exit(mp); 6422 error = vn_lock(vp, flags); 6423 if (error != 0) { 6424 vrele(vp); 6425 return (vfs_cache_root_fallback(mp, flags, vpp)); 6426 } 6427 *vpp = vp; 6428 return (0); 6429 } 6430 6431 struct vnode * 6432 vfs_cache_root_clear(struct mount *mp) 6433 { 6434 struct vnode *vp; 6435 6436 /* 6437 * ops > 0 guarantees there is nobody who can see this vnode 6438 */ 6439 MPASS(mp->mnt_vfs_ops > 0); 6440 vp = mp->mnt_rootvnode; 6441 if (vp != NULL) 6442 vn_seqc_write_begin(vp); 6443 mp->mnt_rootvnode = NULL; 6444 return (vp); 6445 } 6446 6447 void 6448 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6449 { 6450 6451 MPASS(mp->mnt_vfs_ops > 0); 6452 vrefact(vp); 6453 mp->mnt_rootvnode = vp; 6454 } 6455 6456 /* 6457 * These are helper functions for filesystems to traverse all 6458 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6459 * 6460 * This interface replaces MNT_VNODE_FOREACH. 6461 */ 6462 6463 struct vnode * 6464 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6465 { 6466 struct vnode *vp; 6467 6468 if (should_yield()) 6469 kern_yield(PRI_USER); 6470 MNT_ILOCK(mp); 6471 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6472 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6473 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6474 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6475 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6476 continue; 6477 VI_LOCK(vp); 6478 if (VN_IS_DOOMED(vp)) { 6479 VI_UNLOCK(vp); 6480 continue; 6481 } 6482 break; 6483 } 6484 if (vp == NULL) { 6485 __mnt_vnode_markerfree_all(mvp, mp); 6486 /* MNT_IUNLOCK(mp); -- done in above function */ 6487 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6488 return (NULL); 6489 } 6490 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6491 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6492 MNT_IUNLOCK(mp); 6493 return (vp); 6494 } 6495 6496 struct vnode * 6497 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6498 { 6499 struct vnode *vp; 6500 6501 *mvp = vn_alloc_marker(mp); 6502 MNT_ILOCK(mp); 6503 MNT_REF(mp); 6504 6505 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6506 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6507 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6508 continue; 6509 VI_LOCK(vp); 6510 if (VN_IS_DOOMED(vp)) { 6511 VI_UNLOCK(vp); 6512 continue; 6513 } 6514 break; 6515 } 6516 if (vp == NULL) { 6517 MNT_REL(mp); 6518 MNT_IUNLOCK(mp); 6519 vn_free_marker(*mvp); 6520 *mvp = NULL; 6521 return (NULL); 6522 } 6523 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6524 MNT_IUNLOCK(mp); 6525 return (vp); 6526 } 6527 6528 void 6529 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6530 { 6531 6532 if (*mvp == NULL) { 6533 MNT_IUNLOCK(mp); 6534 return; 6535 } 6536 6537 mtx_assert(MNT_MTX(mp), MA_OWNED); 6538 6539 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6540 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6541 MNT_REL(mp); 6542 MNT_IUNLOCK(mp); 6543 vn_free_marker(*mvp); 6544 *mvp = NULL; 6545 } 6546 6547 /* 6548 * These are helper functions for filesystems to traverse their 6549 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6550 */ 6551 static void 6552 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6553 { 6554 6555 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6556 6557 MNT_ILOCK(mp); 6558 MNT_REL(mp); 6559 MNT_IUNLOCK(mp); 6560 vn_free_marker(*mvp); 6561 *mvp = NULL; 6562 } 6563 6564 /* 6565 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6566 * conventional lock order during mnt_vnode_next_lazy iteration. 6567 * 6568 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6569 * The list lock is dropped and reacquired. On success, both locks are held. 6570 * On failure, the mount vnode list lock is held but the vnode interlock is 6571 * not, and the procedure may have yielded. 6572 */ 6573 static bool 6574 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6575 struct vnode *vp) 6576 { 6577 6578 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6579 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6580 ("%s: bad marker", __func__)); 6581 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6582 ("%s: inappropriate vnode", __func__)); 6583 ASSERT_VI_UNLOCKED(vp, __func__); 6584 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6585 6586 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6587 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6588 6589 /* 6590 * Note we may be racing against vdrop which transitioned the hold 6591 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine, 6592 * if we are the only user after we get the interlock we will just 6593 * vdrop. 6594 */ 6595 vhold(vp); 6596 mtx_unlock(&mp->mnt_listmtx); 6597 VI_LOCK(vp); 6598 if (VN_IS_DOOMED(vp)) { 6599 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6600 goto out_lost; 6601 } 6602 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6603 /* 6604 * There is nothing to do if we are the last user. 6605 */ 6606 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6607 goto out_lost; 6608 mtx_lock(&mp->mnt_listmtx); 6609 return (true); 6610 out_lost: 6611 vdropl(vp); 6612 maybe_yield(); 6613 mtx_lock(&mp->mnt_listmtx); 6614 return (false); 6615 } 6616 6617 static struct vnode * 6618 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6619 void *cbarg) 6620 { 6621 struct vnode *vp; 6622 6623 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6624 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6625 restart: 6626 vp = TAILQ_NEXT(*mvp, v_lazylist); 6627 while (vp != NULL) { 6628 if (vp->v_type == VMARKER) { 6629 vp = TAILQ_NEXT(vp, v_lazylist); 6630 continue; 6631 } 6632 /* 6633 * See if we want to process the vnode. Note we may encounter a 6634 * long string of vnodes we don't care about and hog the list 6635 * as a result. Check for it and requeue the marker. 6636 */ 6637 VNPASS(!VN_IS_DOOMED(vp), vp); 6638 if (!cb(vp, cbarg)) { 6639 if (!should_yield()) { 6640 vp = TAILQ_NEXT(vp, v_lazylist); 6641 continue; 6642 } 6643 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 6644 v_lazylist); 6645 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 6646 v_lazylist); 6647 mtx_unlock(&mp->mnt_listmtx); 6648 kern_yield(PRI_USER); 6649 mtx_lock(&mp->mnt_listmtx); 6650 goto restart; 6651 } 6652 /* 6653 * Try-lock because this is the wrong lock order. 6654 */ 6655 if (!VI_TRYLOCK(vp) && 6656 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 6657 goto restart; 6658 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 6659 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 6660 ("alien vnode on the lazy list %p %p", vp, mp)); 6661 VNPASS(vp->v_mount == mp, vp); 6662 VNPASS(!VN_IS_DOOMED(vp), vp); 6663 break; 6664 } 6665 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6666 6667 /* Check if we are done */ 6668 if (vp == NULL) { 6669 mtx_unlock(&mp->mnt_listmtx); 6670 mnt_vnode_markerfree_lazy(mvp, mp); 6671 return (NULL); 6672 } 6673 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 6674 mtx_unlock(&mp->mnt_listmtx); 6675 ASSERT_VI_LOCKED(vp, "lazy iter"); 6676 return (vp); 6677 } 6678 6679 struct vnode * 6680 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6681 void *cbarg) 6682 { 6683 6684 if (should_yield()) 6685 kern_yield(PRI_USER); 6686 mtx_lock(&mp->mnt_listmtx); 6687 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6688 } 6689 6690 struct vnode * 6691 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6692 void *cbarg) 6693 { 6694 struct vnode *vp; 6695 6696 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 6697 return (NULL); 6698 6699 *mvp = vn_alloc_marker(mp); 6700 MNT_ILOCK(mp); 6701 MNT_REF(mp); 6702 MNT_IUNLOCK(mp); 6703 6704 mtx_lock(&mp->mnt_listmtx); 6705 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 6706 if (vp == NULL) { 6707 mtx_unlock(&mp->mnt_listmtx); 6708 mnt_vnode_markerfree_lazy(mvp, mp); 6709 return (NULL); 6710 } 6711 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 6712 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 6713 } 6714 6715 void 6716 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6717 { 6718 6719 if (*mvp == NULL) 6720 return; 6721 6722 mtx_lock(&mp->mnt_listmtx); 6723 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 6724 mtx_unlock(&mp->mnt_listmtx); 6725 mnt_vnode_markerfree_lazy(mvp, mp); 6726 } 6727 6728 int 6729 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 6730 { 6731 6732 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 6733 cnp->cn_flags &= ~NOEXECCHECK; 6734 return (0); 6735 } 6736 6737 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread)); 6738 } 6739 6740 /* 6741 * Do not use this variant unless you have means other than the hold count 6742 * to prevent the vnode from getting freed. 6743 */ 6744 void 6745 vn_seqc_write_begin_unheld_locked(struct vnode *vp) 6746 { 6747 6748 ASSERT_VI_LOCKED(vp, __func__); 6749 VNPASS(vp->v_seqc_users >= 0, vp); 6750 vp->v_seqc_users++; 6751 if (vp->v_seqc_users == 1) 6752 seqc_sleepable_write_begin(&vp->v_seqc); 6753 } 6754 6755 void 6756 vn_seqc_write_begin_locked(struct vnode *vp) 6757 { 6758 6759 ASSERT_VI_LOCKED(vp, __func__); 6760 VNPASS(vp->v_holdcnt > 0, vp); 6761 vn_seqc_write_begin_unheld_locked(vp); 6762 } 6763 6764 void 6765 vn_seqc_write_begin(struct vnode *vp) 6766 { 6767 6768 VI_LOCK(vp); 6769 vn_seqc_write_begin_locked(vp); 6770 VI_UNLOCK(vp); 6771 } 6772 6773 void 6774 vn_seqc_write_begin_unheld(struct vnode *vp) 6775 { 6776 6777 VI_LOCK(vp); 6778 vn_seqc_write_begin_unheld_locked(vp); 6779 VI_UNLOCK(vp); 6780 } 6781 6782 void 6783 vn_seqc_write_end_locked(struct vnode *vp) 6784 { 6785 6786 ASSERT_VI_LOCKED(vp, __func__); 6787 VNPASS(vp->v_seqc_users > 0, vp); 6788 vp->v_seqc_users--; 6789 if (vp->v_seqc_users == 0) 6790 seqc_sleepable_write_end(&vp->v_seqc); 6791 } 6792 6793 void 6794 vn_seqc_write_end(struct vnode *vp) 6795 { 6796 6797 VI_LOCK(vp); 6798 vn_seqc_write_end_locked(vp); 6799 VI_UNLOCK(vp); 6800 } 6801