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