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 37 /* 38 * External virtual filesystem routines 39 */ 40 41 #include <sys/cdefs.h> 42 #include "opt_ddb.h" 43 #include "opt_watchdog.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/asan.h> 48 #include <sys/bio.h> 49 #include <sys/buf.h> 50 #include <sys/capsicum.h> 51 #include <sys/condvar.h> 52 #include <sys/conf.h> 53 #include <sys/counter.h> 54 #include <sys/dirent.h> 55 #include <sys/event.h> 56 #include <sys/eventhandler.h> 57 #include <sys/extattr.h> 58 #include <sys/file.h> 59 #include <sys/fcntl.h> 60 #include <sys/jail.h> 61 #include <sys/kdb.h> 62 #include <sys/kernel.h> 63 #include <sys/kthread.h> 64 #include <sys/ktr.h> 65 #include <sys/limits.h> 66 #include <sys/lockf.h> 67 #include <sys/malloc.h> 68 #include <sys/mount.h> 69 #include <sys/namei.h> 70 #include <sys/pctrie.h> 71 #include <sys/priv.h> 72 #include <sys/reboot.h> 73 #include <sys/refcount.h> 74 #include <sys/rwlock.h> 75 #include <sys/sched.h> 76 #include <sys/sleepqueue.h> 77 #include <sys/smr.h> 78 #include <sys/smp.h> 79 #include <sys/stat.h> 80 #include <sys/sysctl.h> 81 #include <sys/syslog.h> 82 #include <sys/vmmeter.h> 83 #include <sys/vnode.h> 84 #include <sys/watchdog.h> 85 86 #include <machine/stdarg.h> 87 88 #include <security/mac/mac_framework.h> 89 90 #include <vm/vm.h> 91 #include <vm/vm_object.h> 92 #include <vm/vm_extern.h> 93 #include <vm/pmap.h> 94 #include <vm/vm_map.h> 95 #include <vm/vm_page.h> 96 #include <vm/vm_kern.h> 97 #include <vm/vnode_pager.h> 98 #include <vm/uma.h> 99 100 #if defined(DEBUG_VFS_LOCKS) && (!defined(INVARIANTS) || !defined(WITNESS)) 101 #error DEBUG_VFS_LOCKS requires INVARIANTS and WITNESS 102 #endif 103 104 #ifdef DDB 105 #include <ddb/ddb.h> 106 #endif 107 108 static void delmntque(struct vnode *vp); 109 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 110 int slpflag, int slptimeo); 111 static void syncer_shutdown(void *arg, int howto); 112 static int vtryrecycle(struct vnode *vp, bool isvnlru); 113 static void v_init_counters(struct vnode *); 114 static void vn_seqc_init(struct vnode *); 115 static void vn_seqc_write_end_free(struct vnode *vp); 116 static void vgonel(struct vnode *); 117 static bool vhold_recycle_free(struct vnode *); 118 static void vdropl_recycle(struct vnode *vp); 119 static void vdrop_recycle(struct vnode *vp); 120 static void vfs_knllock(void *arg); 121 static void vfs_knlunlock(void *arg); 122 static void vfs_knl_assert_lock(void *arg, int what); 123 static void destroy_vpollinfo(struct vpollinfo *vi); 124 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 125 daddr_t startlbn, daddr_t endlbn); 126 static void vnlru_recalc(void); 127 128 static SYSCTL_NODE(_vfs, OID_AUTO, vnode, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 129 "vnode configuration and statistics"); 130 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, param, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 131 "vnode configuration"); 132 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 133 "vnode statistics"); 134 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, vnlru, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 135 "vnode recycling"); 136 137 /* 138 * Number of vnodes in existence. Increased whenever getnewvnode() 139 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode. 140 */ 141 static u_long __exclusive_cache_line numvnodes; 142 143 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 144 "Number of vnodes in existence (legacy)"); 145 SYSCTL_ULONG(_vfs_vnode_stats, OID_AUTO, count, CTLFLAG_RD, &numvnodes, 0, 146 "Number of vnodes in existence"); 147 148 static counter_u64_t vnodes_created; 149 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 150 "Number of vnodes created by getnewvnode (legacy)"); 151 SYSCTL_COUNTER_U64(_vfs_vnode_stats, OID_AUTO, created, CTLFLAG_RD, &vnodes_created, 152 "Number of vnodes created by getnewvnode"); 153 154 /* 155 * Conversion tables for conversion from vnode types to inode formats 156 * and back. 157 */ 158 __enum_uint8(vtype) iftovt_tab[16] = { 159 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 160 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 161 }; 162 int vttoif_tab[10] = { 163 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 164 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 165 }; 166 167 /* 168 * List of allocates vnodes in the system. 169 */ 170 static TAILQ_HEAD(freelst, vnode) vnode_list; 171 static struct vnode *vnode_list_free_marker; 172 static struct vnode *vnode_list_reclaim_marker; 173 174 /* 175 * "Free" vnode target. Free vnodes are rarely completely free, but are 176 * just ones that are cheap to recycle. Usually they are for files which 177 * have been stat'd but not read; these usually have inode and namecache 178 * data attached to them. This target is the preferred minimum size of a 179 * sub-cache consisting mostly of such files. The system balances the size 180 * of this sub-cache with its complement to try to prevent either from 181 * thrashing while the other is relatively inactive. The targets express 182 * a preference for the best balance. 183 * 184 * "Above" this target there are 2 further targets (watermarks) related 185 * to recyling of free vnodes. In the best-operating case, the cache is 186 * exactly full, the free list has size between vlowat and vhiwat above the 187 * free target, and recycling from it and normal use maintains this state. 188 * Sometimes the free list is below vlowat or even empty, but this state 189 * is even better for immediate use provided the cache is not full. 190 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 191 * ones) to reach one of these states. The watermarks are currently hard- 192 * coded as 4% and 9% of the available space higher. These and the default 193 * of 25% for wantfreevnodes are too large if the memory size is large. 194 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 195 * whenever vnlru_proc() becomes active. 196 */ 197 static long wantfreevnodes; 198 static long __exclusive_cache_line freevnodes; 199 static long freevnodes_old; 200 201 static u_long recycles_count; 202 SYSCTL_ULONG(_vfs, OID_AUTO, recycles, CTLFLAG_RD | CTLFLAG_STATS, &recycles_count, 0, 203 "Number of vnodes recycled to meet vnode cache targets (legacy)"); 204 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, recycles, CTLFLAG_RD | CTLFLAG_STATS, 205 &recycles_count, 0, 206 "Number of vnodes recycled to meet vnode cache targets"); 207 208 static u_long recycles_free_count; 209 SYSCTL_ULONG(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD | CTLFLAG_STATS, 210 &recycles_free_count, 0, 211 "Number of free vnodes recycled to meet vnode cache targets (legacy)"); 212 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, recycles_free, CTLFLAG_RD | CTLFLAG_STATS, 213 &recycles_free_count, 0, 214 "Number of free vnodes recycled to meet vnode cache targets"); 215 216 static counter_u64_t direct_recycles_free_count; 217 SYSCTL_COUNTER_U64(_vfs_vnode_vnlru, OID_AUTO, direct_recycles_free, CTLFLAG_RD, 218 &direct_recycles_free_count, 219 "Number of free vnodes recycled by vn_alloc callers to meet vnode cache targets"); 220 221 static counter_u64_t vnode_skipped_requeues; 222 SYSCTL_COUNTER_U64(_vfs_vnode_stats, OID_AUTO, skipped_requeues, CTLFLAG_RD, &vnode_skipped_requeues, 223 "Number of times LRU requeue was skipped due to lock contention"); 224 225 static u_long deferred_inact; 226 SYSCTL_ULONG(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD, 227 &deferred_inact, 0, "Number of times inactive processing was deferred"); 228 229 /* To keep more than one thread at a time from running vfs_getnewfsid */ 230 static struct mtx mntid_mtx; 231 232 /* 233 * Lock for any access to the following: 234 * vnode_list 235 * numvnodes 236 * freevnodes 237 */ 238 static struct mtx __exclusive_cache_line vnode_list_mtx; 239 240 /* Publicly exported FS */ 241 struct nfs_public nfs_pub; 242 243 static uma_zone_t buf_trie_zone; 244 static smr_t buf_trie_smr; 245 246 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 247 static uma_zone_t vnode_zone; 248 MALLOC_DEFINE(M_VNODEPOLL, "VN POLL", "vnode poll"); 249 250 __read_frequently smr_t vfs_smr; 251 252 /* 253 * The workitem queue. 254 * 255 * It is useful to delay writes of file data and filesystem metadata 256 * for tens of seconds so that quickly created and deleted files need 257 * not waste disk bandwidth being created and removed. To realize this, 258 * we append vnodes to a "workitem" queue. When running with a soft 259 * updates implementation, most pending metadata dependencies should 260 * not wait for more than a few seconds. Thus, mounted on block devices 261 * are delayed only about a half the time that file data is delayed. 262 * Similarly, directory updates are more critical, so are only delayed 263 * about a third the time that file data is delayed. Thus, there are 264 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 265 * one each second (driven off the filesystem syncer process). The 266 * syncer_delayno variable indicates the next queue that is to be processed. 267 * Items that need to be processed soon are placed in this queue: 268 * 269 * syncer_workitem_pending[syncer_delayno] 270 * 271 * A delay of fifteen seconds is done by placing the request fifteen 272 * entries later in the queue: 273 * 274 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 275 * 276 */ 277 static int syncer_delayno; 278 static long syncer_mask; 279 LIST_HEAD(synclist, bufobj); 280 static struct synclist *syncer_workitem_pending; 281 /* 282 * The sync_mtx protects: 283 * bo->bo_synclist 284 * sync_vnode_count 285 * syncer_delayno 286 * syncer_state 287 * syncer_workitem_pending 288 * syncer_worklist_len 289 * rushjob 290 */ 291 static struct mtx sync_mtx; 292 static struct cv sync_wakeup; 293 294 #define SYNCER_MAXDELAY 32 295 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 296 static int syncdelay = 30; /* max time to delay syncing data */ 297 static int filedelay = 30; /* time to delay syncing files */ 298 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 299 "Time to delay syncing files (in seconds)"); 300 static int dirdelay = 29; /* time to delay syncing directories */ 301 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 302 "Time to delay syncing directories (in seconds)"); 303 static int metadelay = 28; /* time to delay syncing metadata */ 304 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 305 "Time to delay syncing metadata (in seconds)"); 306 static int rushjob; /* number of slots to run ASAP */ 307 static int stat_rush_requests; /* number of times I/O speeded up */ 308 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 309 "Number of times I/O speeded up (rush requests)"); 310 311 #define VDBATCH_SIZE 8 312 struct vdbatch { 313 u_int index; 314 struct mtx lock; 315 struct vnode *tab[VDBATCH_SIZE]; 316 }; 317 DPCPU_DEFINE_STATIC(struct vdbatch, vd); 318 319 static void vdbatch_dequeue(struct vnode *vp); 320 321 /* 322 * When shutting down the syncer, run it at four times normal speed. 323 */ 324 #define SYNCER_SHUTDOWN_SPEEDUP 4 325 static int sync_vnode_count; 326 static int syncer_worklist_len; 327 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 328 syncer_state; 329 330 /* Target for maximum number of vnodes. */ 331 u_long desiredvnodes; 332 static u_long gapvnodes; /* gap between wanted and desired */ 333 static u_long vhiwat; /* enough extras after expansion */ 334 static u_long vlowat; /* minimal extras before expansion */ 335 static bool vstir; /* nonzero to stir non-free vnodes */ 336 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 337 338 static u_long vnlru_read_freevnodes(void); 339 340 /* 341 * Note that no attempt is made to sanitize these parameters. 342 */ 343 static int 344 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS) 345 { 346 u_long val; 347 int error; 348 349 val = desiredvnodes; 350 error = sysctl_handle_long(oidp, &val, 0, req); 351 if (error != 0 || req->newptr == NULL) 352 return (error); 353 354 if (val == desiredvnodes) 355 return (0); 356 mtx_lock(&vnode_list_mtx); 357 desiredvnodes = val; 358 wantfreevnodes = desiredvnodes / 4; 359 vnlru_recalc(); 360 mtx_unlock(&vnode_list_mtx); 361 /* 362 * XXX There is no protection against multiple threads changing 363 * desiredvnodes at the same time. Locking above only helps vnlru and 364 * getnewvnode. 365 */ 366 vfs_hash_changesize(desiredvnodes); 367 cache_changesize(desiredvnodes); 368 return (0); 369 } 370 371 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 372 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes, 373 "LU", "Target for maximum number of vnodes (legacy)"); 374 SYSCTL_PROC(_vfs_vnode_param, OID_AUTO, limit, 375 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes, 376 "LU", "Target for maximum number of vnodes"); 377 378 static int 379 sysctl_freevnodes(SYSCTL_HANDLER_ARGS) 380 { 381 u_long rfreevnodes; 382 383 rfreevnodes = vnlru_read_freevnodes(); 384 return (sysctl_handle_long(oidp, &rfreevnodes, 0, req)); 385 } 386 387 SYSCTL_PROC(_vfs, OID_AUTO, freevnodes, 388 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_freevnodes, 389 "LU", "Number of \"free\" vnodes (legacy)"); 390 SYSCTL_PROC(_vfs_vnode_stats, OID_AUTO, free, 391 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_freevnodes, 392 "LU", "Number of \"free\" vnodes"); 393 394 static int 395 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS) 396 { 397 u_long val; 398 int error; 399 400 val = wantfreevnodes; 401 error = sysctl_handle_long(oidp, &val, 0, req); 402 if (error != 0 || req->newptr == NULL) 403 return (error); 404 405 if (val == wantfreevnodes) 406 return (0); 407 mtx_lock(&vnode_list_mtx); 408 wantfreevnodes = val; 409 vnlru_recalc(); 410 mtx_unlock(&vnode_list_mtx); 411 return (0); 412 } 413 414 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes, 415 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes, 416 "LU", "Target for minimum number of \"free\" vnodes (legacy)"); 417 SYSCTL_PROC(_vfs_vnode_param, OID_AUTO, wantfree, 418 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes, 419 "LU", "Target for minimum number of \"free\" vnodes"); 420 421 static int vnlru_nowhere; 422 SYSCTL_INT(_vfs_vnode_vnlru, OID_AUTO, failed_runs, CTLFLAG_RD | CTLFLAG_STATS, 423 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 424 425 static int 426 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 427 { 428 struct vnode *vp; 429 struct nameidata nd; 430 char *buf; 431 unsigned long ndflags; 432 int error; 433 434 if (req->newptr == NULL) 435 return (EINVAL); 436 if (req->newlen >= PATH_MAX) 437 return (E2BIG); 438 439 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK); 440 error = SYSCTL_IN(req, buf, req->newlen); 441 if (error != 0) 442 goto out; 443 444 buf[req->newlen] = '\0'; 445 446 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1; 447 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf); 448 if ((error = namei(&nd)) != 0) 449 goto out; 450 vp = nd.ni_vp; 451 452 if (VN_IS_DOOMED(vp)) { 453 /* 454 * This vnode is being recycled. Return != 0 to let the caller 455 * know that the sysctl had no effect. Return EAGAIN because a 456 * subsequent call will likely succeed (since namei will create 457 * a new vnode if necessary) 458 */ 459 error = EAGAIN; 460 goto putvnode; 461 } 462 463 vgone(vp); 464 putvnode: 465 vput(vp); 466 NDFREE_PNBUF(&nd); 467 out: 468 free(buf, M_TEMP); 469 return (error); 470 } 471 472 static int 473 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 474 { 475 struct thread *td = curthread; 476 struct vnode *vp; 477 struct file *fp; 478 int error; 479 int fd; 480 481 if (req->newptr == NULL) 482 return (EBADF); 483 484 error = sysctl_handle_int(oidp, &fd, 0, req); 485 if (error != 0) 486 return (error); 487 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 488 if (error != 0) 489 return (error); 490 vp = fp->f_vnode; 491 492 error = vn_lock(vp, LK_EXCLUSIVE); 493 if (error != 0) 494 goto drop; 495 496 vgone(vp); 497 VOP_UNLOCK(vp); 498 drop: 499 fdrop(fp, td); 500 return (error); 501 } 502 503 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 504 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 505 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 506 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 507 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 508 sysctl_ftry_reclaim_vnode, "I", 509 "Try to reclaim a vnode by its file descriptor"); 510 511 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 512 #define vnsz2log 8 513 #ifndef DEBUG_LOCKS 514 _Static_assert(sizeof(struct vnode) >= 1UL << vnsz2log && 515 sizeof(struct vnode) < 1UL << (vnsz2log + 1), 516 "vnsz2log needs to be updated"); 517 #endif 518 519 /* 520 * Support for the bufobj clean & dirty pctrie. 521 */ 522 static void * 523 buf_trie_alloc(struct pctrie *ptree) 524 { 525 return (uma_zalloc_smr(buf_trie_zone, M_NOWAIT)); 526 } 527 528 static void 529 buf_trie_free(struct pctrie *ptree, void *node) 530 { 531 uma_zfree_smr(buf_trie_zone, node); 532 } 533 PCTRIE_DEFINE_SMR(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free, 534 buf_trie_smr); 535 536 /* 537 * Initialize the vnode management data structures. 538 * 539 * Reevaluate the following cap on the number of vnodes after the physical 540 * memory size exceeds 512GB. In the limit, as the physical memory size 541 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 542 */ 543 #ifndef MAXVNODES_MAX 544 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */ 545 #endif 546 547 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 548 549 static struct vnode * 550 vn_alloc_marker(struct mount *mp) 551 { 552 struct vnode *vp; 553 554 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 555 vp->v_type = VMARKER; 556 vp->v_mount = mp; 557 558 return (vp); 559 } 560 561 static void 562 vn_free_marker(struct vnode *vp) 563 { 564 565 MPASS(vp->v_type == VMARKER); 566 free(vp, M_VNODE_MARKER); 567 } 568 569 #ifdef KASAN 570 static int 571 vnode_ctor(void *mem, int size, void *arg __unused, int flags __unused) 572 { 573 kasan_mark(mem, size, roundup2(size, UMA_ALIGN_PTR + 1), 0); 574 return (0); 575 } 576 577 static void 578 vnode_dtor(void *mem, int size, void *arg __unused) 579 { 580 size_t end1, end2, off1, off2; 581 582 _Static_assert(offsetof(struct vnode, v_vnodelist) < 583 offsetof(struct vnode, v_dbatchcpu), 584 "KASAN marks require updating"); 585 586 off1 = offsetof(struct vnode, v_vnodelist); 587 off2 = offsetof(struct vnode, v_dbatchcpu); 588 end1 = off1 + sizeof(((struct vnode *)NULL)->v_vnodelist); 589 end2 = off2 + sizeof(((struct vnode *)NULL)->v_dbatchcpu); 590 591 /* 592 * Access to the v_vnodelist and v_dbatchcpu fields are permitted even 593 * after the vnode has been freed. Try to get some KASAN coverage by 594 * marking everything except those two fields as invalid. Because 595 * KASAN's tracking is not byte-granular, any preceding fields sharing 596 * the same 8-byte aligned word must also be marked valid. 597 */ 598 599 /* Handle the area from the start until v_vnodelist... */ 600 off1 = rounddown2(off1, KASAN_SHADOW_SCALE); 601 kasan_mark(mem, off1, off1, KASAN_UMA_FREED); 602 603 /* ... then the area between v_vnodelist and v_dbatchcpu ... */ 604 off1 = roundup2(end1, KASAN_SHADOW_SCALE); 605 off2 = rounddown2(off2, KASAN_SHADOW_SCALE); 606 if (off2 > off1) 607 kasan_mark((void *)((char *)mem + off1), off2 - off1, 608 off2 - off1, KASAN_UMA_FREED); 609 610 /* ... and finally the area from v_dbatchcpu to the end. */ 611 off2 = roundup2(end2, KASAN_SHADOW_SCALE); 612 kasan_mark((void *)((char *)mem + off2), size - off2, size - off2, 613 KASAN_UMA_FREED); 614 } 615 #endif /* KASAN */ 616 617 /* 618 * Initialize a vnode as it first enters the zone. 619 */ 620 static int 621 vnode_init(void *mem, int size, int flags) 622 { 623 struct vnode *vp; 624 625 vp = mem; 626 bzero(vp, size); 627 /* 628 * Setup locks. 629 */ 630 vp->v_vnlock = &vp->v_lock; 631 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 632 /* 633 * By default, don't allow shared locks unless filesystems opt-in. 634 */ 635 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 636 LK_NOSHARE | LK_IS_VNODE); 637 /* 638 * Initialize bufobj. 639 */ 640 bufobj_init(&vp->v_bufobj, vp); 641 /* 642 * Initialize namecache. 643 */ 644 cache_vnode_init(vp); 645 /* 646 * Initialize rangelocks. 647 */ 648 rangelock_init(&vp->v_rl); 649 650 vp->v_dbatchcpu = NOCPU; 651 652 vp->v_state = VSTATE_DEAD; 653 654 /* 655 * Check vhold_recycle_free for an explanation. 656 */ 657 vp->v_holdcnt = VHOLD_NO_SMR; 658 vp->v_type = VNON; 659 mtx_lock(&vnode_list_mtx); 660 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist); 661 mtx_unlock(&vnode_list_mtx); 662 return (0); 663 } 664 665 /* 666 * Free a vnode when it is cleared from the zone. 667 */ 668 static void 669 vnode_fini(void *mem, int size) 670 { 671 struct vnode *vp; 672 struct bufobj *bo; 673 674 vp = mem; 675 vdbatch_dequeue(vp); 676 mtx_lock(&vnode_list_mtx); 677 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 678 mtx_unlock(&vnode_list_mtx); 679 rangelock_destroy(&vp->v_rl); 680 lockdestroy(vp->v_vnlock); 681 mtx_destroy(&vp->v_interlock); 682 bo = &vp->v_bufobj; 683 rw_destroy(BO_LOCKPTR(bo)); 684 685 kasan_mark(mem, size, size, 0); 686 } 687 688 /* 689 * Provide the size of NFS nclnode and NFS fh for calculation of the 690 * vnode memory consumption. The size is specified directly to 691 * eliminate dependency on NFS-private header. 692 * 693 * Other filesystems may use bigger or smaller (like UFS and ZFS) 694 * private inode data, but the NFS-based estimation is ample enough. 695 * Still, we care about differences in the size between 64- and 32-bit 696 * platforms. 697 * 698 * Namecache structure size is heuristically 699 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 700 */ 701 #ifdef _LP64 702 #define NFS_NCLNODE_SZ (528 + 64) 703 #define NC_SZ 148 704 #else 705 #define NFS_NCLNODE_SZ (360 + 32) 706 #define NC_SZ 92 707 #endif 708 709 static void 710 vntblinit(void *dummy __unused) 711 { 712 struct vdbatch *vd; 713 uma_ctor ctor; 714 uma_dtor dtor; 715 int cpu, physvnodes, virtvnodes; 716 717 /* 718 * Desiredvnodes is a function of the physical memory size and the 719 * kernel's heap size. Generally speaking, it scales with the 720 * physical memory size. The ratio of desiredvnodes to the physical 721 * memory size is 1:16 until desiredvnodes exceeds 98,304. 722 * Thereafter, the 723 * marginal ratio of desiredvnodes to the physical memory size is 724 * 1:64. However, desiredvnodes is limited by the kernel's heap 725 * size. The memory required by desiredvnodes vnodes and vm objects 726 * must not exceed 1/10th of the kernel's heap size. 727 */ 728 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 729 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 730 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 731 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 732 desiredvnodes = min(physvnodes, virtvnodes); 733 if (desiredvnodes > MAXVNODES_MAX) { 734 if (bootverbose) 735 printf("Reducing kern.maxvnodes %lu -> %lu\n", 736 desiredvnodes, MAXVNODES_MAX); 737 desiredvnodes = MAXVNODES_MAX; 738 } 739 wantfreevnodes = desiredvnodes / 4; 740 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 741 TAILQ_INIT(&vnode_list); 742 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF); 743 /* 744 * The lock is taken to appease WITNESS. 745 */ 746 mtx_lock(&vnode_list_mtx); 747 vnlru_recalc(); 748 mtx_unlock(&vnode_list_mtx); 749 vnode_list_free_marker = vn_alloc_marker(NULL); 750 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist); 751 vnode_list_reclaim_marker = vn_alloc_marker(NULL); 752 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist); 753 754 #ifdef KASAN 755 ctor = vnode_ctor; 756 dtor = vnode_dtor; 757 #else 758 ctor = NULL; 759 dtor = NULL; 760 #endif 761 vnode_zone = uma_zcreate("VNODE", sizeof(struct vnode), ctor, dtor, 762 vnode_init, vnode_fini, UMA_ALIGN_PTR, UMA_ZONE_NOKASAN); 763 uma_zone_set_smr(vnode_zone, vfs_smr); 764 765 /* 766 * Preallocate enough nodes to support one-per buf so that 767 * we can not fail an insert. reassignbuf() callers can not 768 * tolerate the insertion failure. 769 */ 770 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 771 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 772 UMA_ZONE_NOFREE | UMA_ZONE_SMR); 773 buf_trie_smr = uma_zone_get_smr(buf_trie_zone); 774 uma_prealloc(buf_trie_zone, nbuf); 775 776 vnodes_created = counter_u64_alloc(M_WAITOK); 777 direct_recycles_free_count = counter_u64_alloc(M_WAITOK); 778 vnode_skipped_requeues = counter_u64_alloc(M_WAITOK); 779 780 /* 781 * Initialize the filesystem syncer. 782 */ 783 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 784 &syncer_mask); 785 syncer_maxdelay = syncer_mask + 1; 786 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 787 cv_init(&sync_wakeup, "syncer"); 788 789 CPU_FOREACH(cpu) { 790 vd = DPCPU_ID_PTR((cpu), vd); 791 bzero(vd, sizeof(*vd)); 792 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF); 793 } 794 } 795 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 796 797 /* 798 * Mark a mount point as busy. Used to synchronize access and to delay 799 * unmounting. Eventually, mountlist_mtx is not released on failure. 800 * 801 * vfs_busy() is a custom lock, it can block the caller. 802 * vfs_busy() only sleeps if the unmount is active on the mount point. 803 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 804 * vnode belonging to mp. 805 * 806 * Lookup uses vfs_busy() to traverse mount points. 807 * root fs var fs 808 * / vnode lock A / vnode lock (/var) D 809 * /var vnode lock B /log vnode lock(/var/log) E 810 * vfs_busy lock C vfs_busy lock F 811 * 812 * Within each file system, the lock order is C->A->B and F->D->E. 813 * 814 * When traversing across mounts, the system follows that lock order: 815 * 816 * C->A->B 817 * | 818 * +->F->D->E 819 * 820 * The lookup() process for namei("/var") illustrates the process: 821 * 1. VOP_LOOKUP() obtains B while A is held 822 * 2. vfs_busy() obtains a shared lock on F while A and B are held 823 * 3. vput() releases lock on B 824 * 4. vput() releases lock on A 825 * 5. VFS_ROOT() obtains lock on D while shared lock on F is held 826 * 6. vfs_unbusy() releases shared lock on F 827 * 7. vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 828 * Attempt to lock A (instead of vp_crossmp) while D is held would 829 * violate the global order, causing deadlocks. 830 * 831 * dounmount() locks B while F is drained. Note that for stacked 832 * filesystems, D and B in the example above may be the same lock, 833 * which introdues potential lock order reversal deadlock between 834 * dounmount() and step 5 above. These filesystems may avoid the LOR 835 * by setting VV_CROSSLOCK on the covered vnode so that lock B will 836 * remain held until after step 5. 837 */ 838 int 839 vfs_busy(struct mount *mp, int flags) 840 { 841 struct mount_pcpu *mpcpu; 842 843 MPASS((flags & ~MBF_MASK) == 0); 844 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 845 846 if (vfs_op_thread_enter(mp, mpcpu)) { 847 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 848 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0); 849 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0); 850 vfs_mp_count_add_pcpu(mpcpu, ref, 1); 851 vfs_mp_count_add_pcpu(mpcpu, lockref, 1); 852 vfs_op_thread_exit(mp, mpcpu); 853 if (flags & MBF_MNTLSTLOCK) 854 mtx_unlock(&mountlist_mtx); 855 return (0); 856 } 857 858 MNT_ILOCK(mp); 859 vfs_assert_mount_counters(mp); 860 MNT_REF(mp); 861 /* 862 * If mount point is currently being unmounted, sleep until the 863 * mount point fate is decided. If thread doing the unmounting fails, 864 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 865 * that this mount point has survived the unmount attempt and vfs_busy 866 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 867 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 868 * about to be really destroyed. vfs_busy needs to release its 869 * reference on the mount point in this case and return with ENOENT, 870 * telling the caller the mount it tried to busy is no longer valid. 871 */ 872 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 873 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), 874 ("%s: non-empty upper mount list with pending unmount", 875 __func__)); 876 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 877 MNT_REL(mp); 878 MNT_IUNLOCK(mp); 879 CTR1(KTR_VFS, "%s: failed busying before sleeping", 880 __func__); 881 return (ENOENT); 882 } 883 if (flags & MBF_MNTLSTLOCK) 884 mtx_unlock(&mountlist_mtx); 885 mp->mnt_kern_flag |= MNTK_MWAIT; 886 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 887 if (flags & MBF_MNTLSTLOCK) 888 mtx_lock(&mountlist_mtx); 889 MNT_ILOCK(mp); 890 } 891 if (flags & MBF_MNTLSTLOCK) 892 mtx_unlock(&mountlist_mtx); 893 mp->mnt_lockref++; 894 MNT_IUNLOCK(mp); 895 return (0); 896 } 897 898 /* 899 * Free a busy filesystem. 900 */ 901 void 902 vfs_unbusy(struct mount *mp) 903 { 904 struct mount_pcpu *mpcpu; 905 int c; 906 907 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 908 909 if (vfs_op_thread_enter(mp, mpcpu)) { 910 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 911 vfs_mp_count_sub_pcpu(mpcpu, lockref, 1); 912 vfs_mp_count_sub_pcpu(mpcpu, ref, 1); 913 vfs_op_thread_exit(mp, mpcpu); 914 return; 915 } 916 917 MNT_ILOCK(mp); 918 vfs_assert_mount_counters(mp); 919 MNT_REL(mp); 920 c = --mp->mnt_lockref; 921 if (mp->mnt_vfs_ops == 0) { 922 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 923 MNT_IUNLOCK(mp); 924 return; 925 } 926 if (c < 0) 927 vfs_dump_mount_counters(mp); 928 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 929 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 930 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 931 mp->mnt_kern_flag &= ~MNTK_DRAINING; 932 wakeup(&mp->mnt_lockref); 933 } 934 MNT_IUNLOCK(mp); 935 } 936 937 /* 938 * Lookup a mount point by filesystem identifier. 939 */ 940 struct mount * 941 vfs_getvfs(fsid_t *fsid) 942 { 943 struct mount *mp; 944 945 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 946 mtx_lock(&mountlist_mtx); 947 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 948 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 949 vfs_ref(mp); 950 mtx_unlock(&mountlist_mtx); 951 return (mp); 952 } 953 } 954 mtx_unlock(&mountlist_mtx); 955 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 956 return ((struct mount *) 0); 957 } 958 959 /* 960 * Lookup a mount point by filesystem identifier, busying it before 961 * returning. 962 * 963 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 964 * cache for popular filesystem identifiers. The cache is lockess, using 965 * the fact that struct mount's are never freed. In worst case we may 966 * get pointer to unmounted or even different filesystem, so we have to 967 * check what we got, and go slow way if so. 968 */ 969 struct mount * 970 vfs_busyfs(fsid_t *fsid) 971 { 972 #define FSID_CACHE_SIZE 256 973 typedef struct mount * volatile vmp_t; 974 static vmp_t cache[FSID_CACHE_SIZE]; 975 struct mount *mp; 976 int error; 977 uint32_t hash; 978 979 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 980 hash = fsid->val[0] ^ fsid->val[1]; 981 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 982 mp = cache[hash]; 983 if (mp == NULL || fsidcmp(&mp->mnt_stat.f_fsid, fsid) != 0) 984 goto slow; 985 if (vfs_busy(mp, 0) != 0) { 986 cache[hash] = NULL; 987 goto slow; 988 } 989 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) 990 return (mp); 991 else 992 vfs_unbusy(mp); 993 994 slow: 995 mtx_lock(&mountlist_mtx); 996 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 997 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) { 998 error = vfs_busy(mp, MBF_MNTLSTLOCK); 999 if (error) { 1000 cache[hash] = NULL; 1001 mtx_unlock(&mountlist_mtx); 1002 return (NULL); 1003 } 1004 cache[hash] = mp; 1005 return (mp); 1006 } 1007 } 1008 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 1009 mtx_unlock(&mountlist_mtx); 1010 return ((struct mount *) 0); 1011 } 1012 1013 /* 1014 * Check if a user can access privileged mount options. 1015 */ 1016 int 1017 vfs_suser(struct mount *mp, struct thread *td) 1018 { 1019 int error; 1020 1021 if (jailed(td->td_ucred)) { 1022 /* 1023 * If the jail of the calling thread lacks permission for 1024 * this type of file system, deny immediately. 1025 */ 1026 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 1027 return (EPERM); 1028 1029 /* 1030 * If the file system was mounted outside the jail of the 1031 * calling thread, deny immediately. 1032 */ 1033 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 1034 return (EPERM); 1035 } 1036 1037 /* 1038 * If file system supports delegated administration, we don't check 1039 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 1040 * by the file system itself. 1041 * If this is not the user that did original mount, we check for 1042 * the PRIV_VFS_MOUNT_OWNER privilege. 1043 */ 1044 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 1045 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 1046 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 1047 return (error); 1048 } 1049 return (0); 1050 } 1051 1052 /* 1053 * Get a new unique fsid. Try to make its val[0] unique, since this value 1054 * will be used to create fake device numbers for stat(). Also try (but 1055 * not so hard) make its val[0] unique mod 2^16, since some emulators only 1056 * support 16-bit device numbers. We end up with unique val[0]'s for the 1057 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 1058 * 1059 * Keep in mind that several mounts may be running in parallel. Starting 1060 * the search one past where the previous search terminated is both a 1061 * micro-optimization and a defense against returning the same fsid to 1062 * different mounts. 1063 */ 1064 void 1065 vfs_getnewfsid(struct mount *mp) 1066 { 1067 static uint16_t mntid_base; 1068 struct mount *nmp; 1069 fsid_t tfsid; 1070 int mtype; 1071 1072 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 1073 mtx_lock(&mntid_mtx); 1074 mtype = mp->mnt_vfc->vfc_typenum; 1075 tfsid.val[1] = mtype; 1076 mtype = (mtype & 0xFF) << 24; 1077 for (;;) { 1078 tfsid.val[0] = makedev(255, 1079 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 1080 mntid_base++; 1081 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 1082 break; 1083 vfs_rel(nmp); 1084 } 1085 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 1086 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 1087 mtx_unlock(&mntid_mtx); 1088 } 1089 1090 /* 1091 * Knob to control the precision of file timestamps: 1092 * 1093 * 0 = seconds only; nanoseconds zeroed. 1094 * 1 = seconds and nanoseconds, accurate within 1/HZ. 1095 * 2 = seconds and nanoseconds, truncated to microseconds. 1096 * >=3 = seconds and nanoseconds, maximum precision. 1097 */ 1098 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 1099 1100 static int timestamp_precision = TSP_USEC; 1101 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 1102 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 1103 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 1104 "3+: sec + ns (max. precision))"); 1105 1106 /* 1107 * Get a current timestamp. 1108 */ 1109 void 1110 vfs_timestamp(struct timespec *tsp) 1111 { 1112 struct timeval tv; 1113 1114 switch (timestamp_precision) { 1115 case TSP_SEC: 1116 tsp->tv_sec = time_second; 1117 tsp->tv_nsec = 0; 1118 break; 1119 case TSP_HZ: 1120 getnanotime(tsp); 1121 break; 1122 case TSP_USEC: 1123 microtime(&tv); 1124 TIMEVAL_TO_TIMESPEC(&tv, tsp); 1125 break; 1126 case TSP_NSEC: 1127 default: 1128 nanotime(tsp); 1129 break; 1130 } 1131 } 1132 1133 /* 1134 * Set vnode attributes to VNOVAL 1135 */ 1136 void 1137 vattr_null(struct vattr *vap) 1138 { 1139 1140 vap->va_type = VNON; 1141 vap->va_size = VNOVAL; 1142 vap->va_bytes = VNOVAL; 1143 vap->va_mode = VNOVAL; 1144 vap->va_nlink = VNOVAL; 1145 vap->va_uid = VNOVAL; 1146 vap->va_gid = VNOVAL; 1147 vap->va_fsid = VNOVAL; 1148 vap->va_fileid = VNOVAL; 1149 vap->va_blocksize = VNOVAL; 1150 vap->va_rdev = VNOVAL; 1151 vap->va_atime.tv_sec = VNOVAL; 1152 vap->va_atime.tv_nsec = VNOVAL; 1153 vap->va_mtime.tv_sec = VNOVAL; 1154 vap->va_mtime.tv_nsec = VNOVAL; 1155 vap->va_ctime.tv_sec = VNOVAL; 1156 vap->va_ctime.tv_nsec = VNOVAL; 1157 vap->va_birthtime.tv_sec = VNOVAL; 1158 vap->va_birthtime.tv_nsec = VNOVAL; 1159 vap->va_flags = VNOVAL; 1160 vap->va_gen = VNOVAL; 1161 vap->va_vaflags = 0; 1162 } 1163 1164 /* 1165 * Try to reduce the total number of vnodes. 1166 * 1167 * This routine (and its user) are buggy in at least the following ways: 1168 * - all parameters were picked years ago when RAM sizes were significantly 1169 * smaller 1170 * - it can pick vnodes based on pages used by the vm object, but filesystems 1171 * like ZFS don't use it making the pick broken 1172 * - since ZFS has its own aging policy it gets partially combated by this one 1173 * - a dedicated method should be provided for filesystems to let them decide 1174 * whether the vnode should be recycled 1175 * 1176 * This routine is called when we have too many vnodes. It attempts 1177 * to free <count> vnodes and will potentially free vnodes that still 1178 * have VM backing store (VM backing store is typically the cause 1179 * of a vnode blowout so we want to do this). Therefore, this operation 1180 * is not considered cheap. 1181 * 1182 * A number of conditions may prevent a vnode from being reclaimed. 1183 * the buffer cache may have references on the vnode, a directory 1184 * vnode may still have references due to the namei cache representing 1185 * underlying files, or the vnode may be in active use. It is not 1186 * desirable to reuse such vnodes. These conditions may cause the 1187 * number of vnodes to reach some minimum value regardless of what 1188 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 1189 * 1190 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 1191 * entries if this argument is strue 1192 * @param trigger Only reclaim vnodes with fewer than this many resident 1193 * pages. 1194 * @param target How many vnodes to reclaim. 1195 * @return The number of vnodes that were reclaimed. 1196 */ 1197 static int 1198 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target) 1199 { 1200 struct vnode *vp, *mvp; 1201 struct mount *mp; 1202 struct vm_object *object; 1203 u_long done; 1204 bool retried; 1205 1206 mtx_assert(&vnode_list_mtx, MA_OWNED); 1207 1208 retried = false; 1209 done = 0; 1210 1211 mvp = vnode_list_reclaim_marker; 1212 restart: 1213 vp = mvp; 1214 while (done < target) { 1215 vp = TAILQ_NEXT(vp, v_vnodelist); 1216 if (__predict_false(vp == NULL)) 1217 break; 1218 1219 if (__predict_false(vp->v_type == VMARKER)) 1220 continue; 1221 1222 /* 1223 * If it's been deconstructed already, it's still 1224 * referenced, or it exceeds the trigger, skip it. 1225 * Also skip free vnodes. We are trying to make space 1226 * for more free vnodes, not reduce their count. 1227 */ 1228 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 || 1229 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src))) 1230 goto next_iter; 1231 1232 if (vp->v_type == VBAD || vp->v_type == VNON) 1233 goto next_iter; 1234 1235 object = atomic_load_ptr(&vp->v_object); 1236 if (object == NULL || object->resident_page_count > trigger) { 1237 goto next_iter; 1238 } 1239 1240 /* 1241 * Handle races against vnode allocation. Filesystems lock the 1242 * vnode some time after it gets returned from getnewvnode, 1243 * despite type and hold count being manipulated earlier. 1244 * Resorting to checking v_mount restores guarantees present 1245 * before the global list was reworked to contain all vnodes. 1246 */ 1247 if (!VI_TRYLOCK(vp)) 1248 goto next_iter; 1249 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1250 VI_UNLOCK(vp); 1251 goto next_iter; 1252 } 1253 if (vp->v_mount == NULL) { 1254 VI_UNLOCK(vp); 1255 goto next_iter; 1256 } 1257 vholdl(vp); 1258 VI_UNLOCK(vp); 1259 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1260 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1261 mtx_unlock(&vnode_list_mtx); 1262 1263 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1264 vdrop_recycle(vp); 1265 goto next_iter_unlocked; 1266 } 1267 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { 1268 vdrop_recycle(vp); 1269 vn_finished_write(mp); 1270 goto next_iter_unlocked; 1271 } 1272 1273 VI_LOCK(vp); 1274 if (vp->v_usecount > 0 || 1275 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1276 (vp->v_object != NULL && vp->v_object->handle == vp && 1277 vp->v_object->resident_page_count > trigger)) { 1278 VOP_UNLOCK(vp); 1279 vdropl_recycle(vp); 1280 vn_finished_write(mp); 1281 goto next_iter_unlocked; 1282 } 1283 recycles_count++; 1284 vgonel(vp); 1285 VOP_UNLOCK(vp); 1286 vdropl_recycle(vp); 1287 vn_finished_write(mp); 1288 done++; 1289 next_iter_unlocked: 1290 maybe_yield(); 1291 mtx_lock(&vnode_list_mtx); 1292 goto restart; 1293 next_iter: 1294 MPASS(vp->v_type != VMARKER); 1295 if (!should_yield()) 1296 continue; 1297 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1298 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1299 mtx_unlock(&vnode_list_mtx); 1300 kern_yield(PRI_USER); 1301 mtx_lock(&vnode_list_mtx); 1302 goto restart; 1303 } 1304 if (done == 0 && !retried) { 1305 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1306 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1307 retried = true; 1308 goto restart; 1309 } 1310 return (done); 1311 } 1312 1313 static int max_free_per_call = 10000; 1314 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_free_per_call, 0, 1315 "limit on vnode free requests per call to the vnlru_free routine (legacy)"); 1316 SYSCTL_INT(_vfs_vnode_vnlru, OID_AUTO, max_free_per_call, CTLFLAG_RW, 1317 &max_free_per_call, 0, 1318 "limit on vnode free requests per call to the vnlru_free routine"); 1319 1320 /* 1321 * Attempt to recycle requested amount of free vnodes. 1322 */ 1323 static int 1324 vnlru_free_impl(int count, struct vfsops *mnt_op, struct vnode *mvp, bool isvnlru) 1325 { 1326 struct vnode *vp; 1327 struct mount *mp; 1328 int ocount; 1329 bool retried; 1330 1331 mtx_assert(&vnode_list_mtx, MA_OWNED); 1332 if (count > max_free_per_call) 1333 count = max_free_per_call; 1334 if (count == 0) { 1335 mtx_unlock(&vnode_list_mtx); 1336 return (0); 1337 } 1338 ocount = count; 1339 retried = false; 1340 vp = mvp; 1341 for (;;) { 1342 vp = TAILQ_NEXT(vp, v_vnodelist); 1343 if (__predict_false(vp == NULL)) { 1344 /* 1345 * The free vnode marker can be past eligible vnodes: 1346 * 1. if vdbatch_process trylock failed 1347 * 2. if vtryrecycle failed 1348 * 1349 * If so, start the scan from scratch. 1350 */ 1351 if (!retried && vnlru_read_freevnodes() > 0) { 1352 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1353 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist); 1354 vp = mvp; 1355 retried = true; 1356 continue; 1357 } 1358 1359 /* 1360 * Give up 1361 */ 1362 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1363 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist); 1364 mtx_unlock(&vnode_list_mtx); 1365 break; 1366 } 1367 if (__predict_false(vp->v_type == VMARKER)) 1368 continue; 1369 if (vp->v_holdcnt > 0) 1370 continue; 1371 /* 1372 * Don't recycle if our vnode is from different type 1373 * of mount point. Note that mp is type-safe, the 1374 * check does not reach unmapped address even if 1375 * vnode is reclaimed. 1376 */ 1377 if (mnt_op != NULL && (mp = vp->v_mount) != NULL && 1378 mp->mnt_op != mnt_op) { 1379 continue; 1380 } 1381 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) { 1382 continue; 1383 } 1384 if (!vhold_recycle_free(vp)) 1385 continue; 1386 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1387 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist); 1388 mtx_unlock(&vnode_list_mtx); 1389 /* 1390 * FIXME: ignores the return value, meaning it may be nothing 1391 * got recycled but it claims otherwise to the caller. 1392 * 1393 * Originally the value started being ignored in 2005 with 1394 * 114a1006a8204aa156e1f9ad6476cdff89cada7f . 1395 * 1396 * Respecting the value can run into significant stalls if most 1397 * vnodes belong to one file system and it has writes 1398 * suspended. In presence of many threads and millions of 1399 * vnodes they keep contending on the vnode_list_mtx lock only 1400 * to find vnodes they can't recycle. 1401 * 1402 * The solution would be to pre-check if the vnode is likely to 1403 * be recycle-able, but it needs to happen with the 1404 * vnode_list_mtx lock held. This runs into a problem where 1405 * VOP_GETWRITEMOUNT (currently needed to find out about if 1406 * writes are frozen) can take locks which LOR against it. 1407 * 1408 * Check nullfs for one example (null_getwritemount). 1409 */ 1410 vtryrecycle(vp, isvnlru); 1411 count--; 1412 if (count == 0) { 1413 break; 1414 } 1415 mtx_lock(&vnode_list_mtx); 1416 vp = mvp; 1417 } 1418 mtx_assert(&vnode_list_mtx, MA_NOTOWNED); 1419 return (ocount - count); 1420 } 1421 1422 /* 1423 * XXX: returns without vnode_list_mtx locked! 1424 */ 1425 static int 1426 vnlru_free_locked_direct(int count) 1427 { 1428 int ret; 1429 1430 mtx_assert(&vnode_list_mtx, MA_OWNED); 1431 ret = vnlru_free_impl(count, NULL, vnode_list_free_marker, false); 1432 mtx_assert(&vnode_list_mtx, MA_NOTOWNED); 1433 return (ret); 1434 } 1435 1436 static int 1437 vnlru_free_locked_vnlru(int count) 1438 { 1439 int ret; 1440 1441 mtx_assert(&vnode_list_mtx, MA_OWNED); 1442 ret = vnlru_free_impl(count, NULL, vnode_list_free_marker, true); 1443 mtx_assert(&vnode_list_mtx, MA_NOTOWNED); 1444 return (ret); 1445 } 1446 1447 static int 1448 vnlru_free_vnlru(int count) 1449 { 1450 1451 mtx_lock(&vnode_list_mtx); 1452 return (vnlru_free_locked_vnlru(count)); 1453 } 1454 1455 void 1456 vnlru_free_vfsops(int count, struct vfsops *mnt_op, struct vnode *mvp) 1457 { 1458 1459 MPASS(mnt_op != NULL); 1460 MPASS(mvp != NULL); 1461 VNPASS(mvp->v_type == VMARKER, mvp); 1462 mtx_lock(&vnode_list_mtx); 1463 vnlru_free_impl(count, mnt_op, mvp, true); 1464 mtx_assert(&vnode_list_mtx, MA_NOTOWNED); 1465 } 1466 1467 struct vnode * 1468 vnlru_alloc_marker(void) 1469 { 1470 struct vnode *mvp; 1471 1472 mvp = vn_alloc_marker(NULL); 1473 mtx_lock(&vnode_list_mtx); 1474 TAILQ_INSERT_BEFORE(vnode_list_free_marker, mvp, v_vnodelist); 1475 mtx_unlock(&vnode_list_mtx); 1476 return (mvp); 1477 } 1478 1479 void 1480 vnlru_free_marker(struct vnode *mvp) 1481 { 1482 mtx_lock(&vnode_list_mtx); 1483 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist); 1484 mtx_unlock(&vnode_list_mtx); 1485 vn_free_marker(mvp); 1486 } 1487 1488 static void 1489 vnlru_recalc(void) 1490 { 1491 1492 mtx_assert(&vnode_list_mtx, MA_OWNED); 1493 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1494 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1495 vlowat = vhiwat / 2; 1496 } 1497 1498 /* 1499 * Attempt to recycle vnodes in a context that is always safe to block. 1500 * Calling vlrurecycle() from the bowels of filesystem code has some 1501 * interesting deadlock problems. 1502 */ 1503 static struct proc *vnlruproc; 1504 static int vnlruproc_sig; 1505 static u_long vnlruproc_kicks; 1506 1507 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, kicks, CTLFLAG_RD, &vnlruproc_kicks, 0, 1508 "Number of times vnlru awakened due to vnode shortage"); 1509 1510 #define VNLRU_COUNT_SLOP 100 1511 1512 /* 1513 * The main freevnodes counter is only updated when a counter local to CPU 1514 * diverges from 0 by more than VNLRU_FREEVNODES_SLOP. CPUs are conditionally 1515 * walked to compute a more accurate total. 1516 * 1517 * Note: the actual value at any given moment can still exceed slop, but it 1518 * should not be by significant margin in practice. 1519 */ 1520 #define VNLRU_FREEVNODES_SLOP 126 1521 1522 static void __noinline 1523 vfs_freevnodes_rollup(int8_t *lfreevnodes) 1524 { 1525 1526 atomic_add_long(&freevnodes, *lfreevnodes); 1527 *lfreevnodes = 0; 1528 critical_exit(); 1529 } 1530 1531 static __inline void 1532 vfs_freevnodes_inc(void) 1533 { 1534 int8_t *lfreevnodes; 1535 1536 critical_enter(); 1537 lfreevnodes = PCPU_PTR(vfs_freevnodes); 1538 (*lfreevnodes)++; 1539 if (__predict_false(*lfreevnodes == VNLRU_FREEVNODES_SLOP)) 1540 vfs_freevnodes_rollup(lfreevnodes); 1541 else 1542 critical_exit(); 1543 } 1544 1545 static __inline void 1546 vfs_freevnodes_dec(void) 1547 { 1548 int8_t *lfreevnodes; 1549 1550 critical_enter(); 1551 lfreevnodes = PCPU_PTR(vfs_freevnodes); 1552 (*lfreevnodes)--; 1553 if (__predict_false(*lfreevnodes == -VNLRU_FREEVNODES_SLOP)) 1554 vfs_freevnodes_rollup(lfreevnodes); 1555 else 1556 critical_exit(); 1557 } 1558 1559 static u_long 1560 vnlru_read_freevnodes(void) 1561 { 1562 long slop, rfreevnodes, rfreevnodes_old; 1563 int cpu; 1564 1565 rfreevnodes = atomic_load_long(&freevnodes); 1566 rfreevnodes_old = atomic_load_long(&freevnodes_old); 1567 1568 if (rfreevnodes > rfreevnodes_old) 1569 slop = rfreevnodes - rfreevnodes_old; 1570 else 1571 slop = rfreevnodes_old - rfreevnodes; 1572 if (slop < VNLRU_FREEVNODES_SLOP) 1573 return (rfreevnodes >= 0 ? rfreevnodes : 0); 1574 CPU_FOREACH(cpu) { 1575 rfreevnodes += cpuid_to_pcpu[cpu]->pc_vfs_freevnodes; 1576 } 1577 atomic_store_long(&freevnodes_old, rfreevnodes); 1578 return (freevnodes_old >= 0 ? freevnodes_old : 0); 1579 } 1580 1581 static bool 1582 vnlru_under(u_long rnumvnodes, u_long limit) 1583 { 1584 u_long rfreevnodes, space; 1585 1586 if (__predict_false(rnumvnodes > desiredvnodes)) 1587 return (true); 1588 1589 space = desiredvnodes - rnumvnodes; 1590 if (space < limit) { 1591 rfreevnodes = vnlru_read_freevnodes(); 1592 if (rfreevnodes > wantfreevnodes) 1593 space += rfreevnodes - wantfreevnodes; 1594 } 1595 return (space < limit); 1596 } 1597 1598 static void 1599 vnlru_kick_locked(void) 1600 { 1601 1602 mtx_assert(&vnode_list_mtx, MA_OWNED); 1603 if (vnlruproc_sig == 0) { 1604 vnlruproc_sig = 1; 1605 vnlruproc_kicks++; 1606 wakeup(vnlruproc); 1607 } 1608 } 1609 1610 static void 1611 vnlru_kick_cond(void) 1612 { 1613 1614 if (vnlru_read_freevnodes() > wantfreevnodes) 1615 return; 1616 1617 if (vnlruproc_sig) 1618 return; 1619 mtx_lock(&vnode_list_mtx); 1620 vnlru_kick_locked(); 1621 mtx_unlock(&vnode_list_mtx); 1622 } 1623 1624 static void 1625 vnlru_proc_sleep(void) 1626 { 1627 1628 if (vnlruproc_sig) { 1629 vnlruproc_sig = 0; 1630 wakeup(&vnlruproc_sig); 1631 } 1632 msleep(vnlruproc, &vnode_list_mtx, PVFS|PDROP, "vlruwt", hz); 1633 } 1634 1635 /* 1636 * A lighter version of the machinery below. 1637 * 1638 * Tries to reach goals only by recycling free vnodes and does not invoke 1639 * uma_reclaim(UMA_RECLAIM_DRAIN). 1640 * 1641 * This works around pathological behavior in vnlru in presence of tons of free 1642 * vnodes, but without having to rewrite the machinery at this time. Said 1643 * behavior boils down to continuously trying to reclaim all kinds of vnodes 1644 * (cycling through all levels of "force") when the count is transiently above 1645 * limit. This happens a lot when all vnodes are used up and vn_alloc 1646 * speculatively increments the counter. 1647 * 1648 * Sample testcase: vnode limit 8388608, 20 separate directory trees each with 1649 * 1 million files in total and 20 find(1) processes stating them in parallel 1650 * (one per each tree). 1651 * 1652 * On a kernel with only stock machinery this needs anywhere between 60 and 120 1653 * seconds to execute (time varies *wildly* between runs). With the workaround 1654 * it consistently stays around 20 seconds [it got further down with later 1655 * changes]. 1656 * 1657 * That is to say the entire thing needs a fundamental redesign (most notably 1658 * to accommodate faster recycling), the above only tries to get it ouf the way. 1659 * 1660 * Return values are: 1661 * -1 -- fallback to regular vnlru loop 1662 * 0 -- do nothing, go to sleep 1663 * >0 -- recycle this many vnodes 1664 */ 1665 static long 1666 vnlru_proc_light_pick(void) 1667 { 1668 u_long rnumvnodes, rfreevnodes; 1669 1670 if (vstir || vnlruproc_sig == 1) 1671 return (-1); 1672 1673 rnumvnodes = atomic_load_long(&numvnodes); 1674 rfreevnodes = vnlru_read_freevnodes(); 1675 1676 /* 1677 * vnode limit might have changed and now we may be at a significant 1678 * excess. Bail if we can't sort it out with free vnodes. 1679 * 1680 * Due to atomic updates the count can legitimately go above 1681 * the limit for a short period, don't bother doing anything in 1682 * that case. 1683 */ 1684 if (rnumvnodes > desiredvnodes + VNLRU_COUNT_SLOP + 10) { 1685 if (rnumvnodes - rfreevnodes >= desiredvnodes || 1686 rfreevnodes <= wantfreevnodes) { 1687 return (-1); 1688 } 1689 1690 return (rnumvnodes - desiredvnodes); 1691 } 1692 1693 /* 1694 * Don't try to reach wantfreevnodes target if there are too few vnodes 1695 * to begin with. 1696 */ 1697 if (rnumvnodes < wantfreevnodes) { 1698 return (0); 1699 } 1700 1701 if (rfreevnodes < wantfreevnodes) { 1702 return (-1); 1703 } 1704 1705 return (0); 1706 } 1707 1708 static bool 1709 vnlru_proc_light(void) 1710 { 1711 long freecount; 1712 1713 mtx_assert(&vnode_list_mtx, MA_NOTOWNED); 1714 1715 freecount = vnlru_proc_light_pick(); 1716 if (freecount == -1) 1717 return (false); 1718 1719 if (freecount != 0) { 1720 vnlru_free_vnlru(freecount); 1721 } 1722 1723 mtx_lock(&vnode_list_mtx); 1724 vnlru_proc_sleep(); 1725 mtx_assert(&vnode_list_mtx, MA_NOTOWNED); 1726 return (true); 1727 } 1728 1729 static u_long uma_reclaim_calls; 1730 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, uma_reclaim_calls, CTLFLAG_RD | CTLFLAG_STATS, 1731 &uma_reclaim_calls, 0, "Number of calls to uma_reclaim"); 1732 1733 static void 1734 vnlru_proc(void) 1735 { 1736 u_long rnumvnodes, rfreevnodes, target; 1737 unsigned long onumvnodes; 1738 int done, force, trigger, usevnodes; 1739 bool reclaim_nc_src, want_reread; 1740 1741 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1742 SHUTDOWN_PRI_FIRST); 1743 1744 force = 0; 1745 want_reread = false; 1746 for (;;) { 1747 kproc_suspend_check(vnlruproc); 1748 1749 if (force == 0 && vnlru_proc_light()) 1750 continue; 1751 1752 mtx_lock(&vnode_list_mtx); 1753 rnumvnodes = atomic_load_long(&numvnodes); 1754 1755 if (want_reread) { 1756 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0; 1757 want_reread = false; 1758 } 1759 1760 /* 1761 * If numvnodes is too large (due to desiredvnodes being 1762 * adjusted using its sysctl, or emergency growth), first 1763 * try to reduce it by discarding free vnodes. 1764 */ 1765 if (rnumvnodes > desiredvnodes + 10) { 1766 vnlru_free_locked_vnlru(rnumvnodes - desiredvnodes); 1767 mtx_lock(&vnode_list_mtx); 1768 rnumvnodes = atomic_load_long(&numvnodes); 1769 } 1770 /* 1771 * Sleep if the vnode cache is in a good state. This is 1772 * when it is not over-full and has space for about a 4% 1773 * or 9% expansion (by growing its size or inexcessively 1774 * reducing free vnode count). Otherwise, try to reclaim 1775 * space for a 10% expansion. 1776 */ 1777 if (vstir && force == 0) { 1778 force = 1; 1779 vstir = false; 1780 } 1781 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) { 1782 vnlru_proc_sleep(); 1783 continue; 1784 } 1785 rfreevnodes = vnlru_read_freevnodes(); 1786 1787 onumvnodes = rnumvnodes; 1788 /* 1789 * Calculate parameters for recycling. These are the same 1790 * throughout the loop to give some semblance of fairness. 1791 * The trigger point is to avoid recycling vnodes with lots 1792 * of resident pages. We aren't trying to free memory; we 1793 * are trying to recycle or at least free vnodes. 1794 */ 1795 if (rnumvnodes <= desiredvnodes) 1796 usevnodes = rnumvnodes - rfreevnodes; 1797 else 1798 usevnodes = rnumvnodes; 1799 if (usevnodes <= 0) 1800 usevnodes = 1; 1801 /* 1802 * The trigger value is chosen to give a conservatively 1803 * large value to ensure that it alone doesn't prevent 1804 * making progress. The value can easily be so large that 1805 * it is effectively infinite in some congested and 1806 * misconfigured cases, and this is necessary. Normally 1807 * it is about 8 to 100 (pages), which is quite large. 1808 */ 1809 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1810 if (force < 2) 1811 trigger = vsmalltrigger; 1812 reclaim_nc_src = force >= 3; 1813 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1); 1814 target = target / 10 + 1; 1815 done = vlrureclaim(reclaim_nc_src, trigger, target); 1816 mtx_unlock(&vnode_list_mtx); 1817 /* 1818 * Total number of vnodes can transiently go slightly above the 1819 * limit (see vn_alloc_hard), no need to call uma_reclaim if 1820 * this happens. 1821 */ 1822 if (onumvnodes + VNLRU_COUNT_SLOP + 1000 > desiredvnodes && 1823 numvnodes <= desiredvnodes) { 1824 uma_reclaim_calls++; 1825 uma_reclaim(UMA_RECLAIM_DRAIN); 1826 } 1827 if (done == 0) { 1828 if (force == 0 || force == 1) { 1829 force = 2; 1830 continue; 1831 } 1832 if (force == 2) { 1833 force = 3; 1834 continue; 1835 } 1836 want_reread = true; 1837 force = 0; 1838 vnlru_nowhere++; 1839 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1840 } else { 1841 want_reread = true; 1842 kern_yield(PRI_USER); 1843 } 1844 } 1845 } 1846 1847 static struct kproc_desc vnlru_kp = { 1848 "vnlru", 1849 vnlru_proc, 1850 &vnlruproc 1851 }; 1852 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1853 &vnlru_kp); 1854 1855 /* 1856 * Routines having to do with the management of the vnode table. 1857 */ 1858 1859 /* 1860 * Try to recycle a freed vnode. 1861 */ 1862 static int 1863 vtryrecycle(struct vnode *vp, bool isvnlru) 1864 { 1865 struct mount *vnmp; 1866 1867 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1868 VNPASS(vp->v_holdcnt > 0, vp); 1869 /* 1870 * This vnode may found and locked via some other list, if so we 1871 * can't recycle it yet. 1872 */ 1873 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1874 CTR2(KTR_VFS, 1875 "%s: impossible to recycle, vp %p lock is already held", 1876 __func__, vp); 1877 vdrop_recycle(vp); 1878 return (EWOULDBLOCK); 1879 } 1880 /* 1881 * Don't recycle if its filesystem is being suspended. 1882 */ 1883 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1884 VOP_UNLOCK(vp); 1885 CTR2(KTR_VFS, 1886 "%s: impossible to recycle, cannot start the write for %p", 1887 __func__, vp); 1888 vdrop_recycle(vp); 1889 return (EBUSY); 1890 } 1891 /* 1892 * If we got this far, we need to acquire the interlock and see if 1893 * anyone picked up this vnode from another list. If not, we will 1894 * mark it with DOOMED via vgonel() so that anyone who does find it 1895 * will skip over it. 1896 */ 1897 VI_LOCK(vp); 1898 if (vp->v_usecount) { 1899 VOP_UNLOCK(vp); 1900 vdropl_recycle(vp); 1901 vn_finished_write(vnmp); 1902 CTR2(KTR_VFS, 1903 "%s: impossible to recycle, %p is already referenced", 1904 __func__, vp); 1905 return (EBUSY); 1906 } 1907 if (!VN_IS_DOOMED(vp)) { 1908 if (isvnlru) 1909 recycles_free_count++; 1910 else 1911 counter_u64_add(direct_recycles_free_count, 1); 1912 vgonel(vp); 1913 } 1914 VOP_UNLOCK(vp); 1915 vdropl_recycle(vp); 1916 vn_finished_write(vnmp); 1917 return (0); 1918 } 1919 1920 /* 1921 * Allocate a new vnode. 1922 * 1923 * The operation never returns an error. Returning an error was disabled 1924 * in r145385 (dated 2005) with the following comment: 1925 * 1926 * XXX Not all VFS_VGET/ffs_vget callers check returns. 1927 * 1928 * Given the age of this commit (almost 15 years at the time of writing this 1929 * comment) restoring the ability to fail requires a significant audit of 1930 * all codepaths. 1931 * 1932 * The routine can try to free a vnode or stall for up to 1 second waiting for 1933 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation. 1934 */ 1935 static u_long vn_alloc_cyclecount; 1936 static u_long vn_alloc_sleeps; 1937 1938 SYSCTL_ULONG(_vfs_vnode_stats, OID_AUTO, alloc_sleeps, CTLFLAG_RD, &vn_alloc_sleeps, 0, 1939 "Number of times vnode allocation blocked waiting on vnlru"); 1940 1941 static struct vnode * __noinline 1942 vn_alloc_hard(struct mount *mp, u_long rnumvnodes, bool bumped) 1943 { 1944 u_long rfreevnodes; 1945 1946 if (bumped) { 1947 if (rnumvnodes > desiredvnodes + VNLRU_COUNT_SLOP) { 1948 atomic_subtract_long(&numvnodes, 1); 1949 bumped = false; 1950 } 1951 } 1952 1953 mtx_lock(&vnode_list_mtx); 1954 1955 if (vn_alloc_cyclecount != 0) { 1956 rnumvnodes = atomic_load_long(&numvnodes); 1957 if (rnumvnodes + 1 < desiredvnodes) { 1958 vn_alloc_cyclecount = 0; 1959 mtx_unlock(&vnode_list_mtx); 1960 goto alloc; 1961 } 1962 1963 rfreevnodes = vnlru_read_freevnodes(); 1964 if (rfreevnodes < wantfreevnodes) { 1965 if (vn_alloc_cyclecount++ >= rfreevnodes) { 1966 vn_alloc_cyclecount = 0; 1967 vstir = true; 1968 } 1969 } else { 1970 vn_alloc_cyclecount = 0; 1971 } 1972 } 1973 1974 /* 1975 * Grow the vnode cache if it will not be above its target max after 1976 * growing. Otherwise, if there is at least one free vnode, try to 1977 * reclaim 1 item from it before growing the cache (possibly above its 1978 * target max if the reclamation failed or is delayed). 1979 */ 1980 if (vnlru_free_locked_direct(1) > 0) 1981 goto alloc; 1982 mtx_assert(&vnode_list_mtx, MA_NOTOWNED); 1983 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { 1984 /* 1985 * Wait for space for a new vnode. 1986 */ 1987 if (bumped) { 1988 atomic_subtract_long(&numvnodes, 1); 1989 bumped = false; 1990 } 1991 mtx_lock(&vnode_list_mtx); 1992 vnlru_kick_locked(); 1993 vn_alloc_sleeps++; 1994 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz); 1995 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes && 1996 vnlru_read_freevnodes() > 1) 1997 vnlru_free_locked_direct(1); 1998 else 1999 mtx_unlock(&vnode_list_mtx); 2000 } 2001 alloc: 2002 mtx_assert(&vnode_list_mtx, MA_NOTOWNED); 2003 if (!bumped) 2004 atomic_add_long(&numvnodes, 1); 2005 vnlru_kick_cond(); 2006 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 2007 } 2008 2009 static struct vnode * 2010 vn_alloc(struct mount *mp) 2011 { 2012 u_long rnumvnodes; 2013 2014 if (__predict_false(vn_alloc_cyclecount != 0)) 2015 return (vn_alloc_hard(mp, 0, false)); 2016 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; 2017 if (__predict_false(vnlru_under(rnumvnodes, vlowat))) { 2018 return (vn_alloc_hard(mp, rnumvnodes, true)); 2019 } 2020 2021 return (uma_zalloc_smr(vnode_zone, M_WAITOK)); 2022 } 2023 2024 static void 2025 vn_free(struct vnode *vp) 2026 { 2027 2028 atomic_subtract_long(&numvnodes, 1); 2029 uma_zfree_smr(vnode_zone, vp); 2030 } 2031 2032 /* 2033 * Allocate a new vnode. 2034 */ 2035 int 2036 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 2037 struct vnode **vpp) 2038 { 2039 struct vnode *vp; 2040 struct thread *td; 2041 struct lock_object *lo; 2042 2043 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 2044 2045 KASSERT(vops->registered, 2046 ("%s: not registered vector op %p\n", __func__, vops)); 2047 cache_validate_vop_vector(mp, vops); 2048 2049 td = curthread; 2050 if (td->td_vp_reserved != NULL) { 2051 vp = td->td_vp_reserved; 2052 td->td_vp_reserved = NULL; 2053 } else { 2054 vp = vn_alloc(mp); 2055 } 2056 counter_u64_add(vnodes_created, 1); 2057 2058 vn_set_state(vp, VSTATE_UNINITIALIZED); 2059 2060 /* 2061 * Locks are given the generic name "vnode" when created. 2062 * Follow the historic practice of using the filesystem 2063 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 2064 * 2065 * Locks live in a witness group keyed on their name. Thus, 2066 * when a lock is renamed, it must also move from the witness 2067 * group of its old name to the witness group of its new name. 2068 * 2069 * The change only needs to be made when the vnode moves 2070 * from one filesystem type to another. We ensure that each 2071 * filesystem use a single static name pointer for its tag so 2072 * that we can compare pointers rather than doing a strcmp(). 2073 */ 2074 lo = &vp->v_vnlock->lock_object; 2075 #ifdef WITNESS 2076 if (lo->lo_name != tag) { 2077 #endif 2078 lo->lo_name = tag; 2079 #ifdef WITNESS 2080 WITNESS_DESTROY(lo); 2081 WITNESS_INIT(lo, tag); 2082 } 2083 #endif 2084 /* 2085 * By default, don't allow shared locks unless filesystems opt-in. 2086 */ 2087 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 2088 /* 2089 * Finalize various vnode identity bits. 2090 */ 2091 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 2092 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 2093 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 2094 vp->v_type = VNON; 2095 vp->v_op = vops; 2096 vp->v_irflag = 0; 2097 v_init_counters(vp); 2098 vn_seqc_init(vp); 2099 vp->v_bufobj.bo_ops = &buf_ops_bio; 2100 #ifdef DIAGNOSTIC 2101 if (mp == NULL && vops != &dead_vnodeops) 2102 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 2103 #endif 2104 #ifdef MAC 2105 mac_vnode_init(vp); 2106 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 2107 mac_vnode_associate_singlelabel(mp, vp); 2108 #endif 2109 if (mp != NULL) { 2110 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 2111 } 2112 2113 /* 2114 * For the filesystems which do not use vfs_hash_insert(), 2115 * still initialize v_hash to have vfs_hash_index() useful. 2116 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 2117 * its own hashing. 2118 */ 2119 vp->v_hash = (uintptr_t)vp >> vnsz2log; 2120 2121 *vpp = vp; 2122 return (0); 2123 } 2124 2125 void 2126 getnewvnode_reserve(void) 2127 { 2128 struct thread *td; 2129 2130 td = curthread; 2131 MPASS(td->td_vp_reserved == NULL); 2132 td->td_vp_reserved = vn_alloc(NULL); 2133 } 2134 2135 void 2136 getnewvnode_drop_reserve(void) 2137 { 2138 struct thread *td; 2139 2140 td = curthread; 2141 if (td->td_vp_reserved != NULL) { 2142 vn_free(td->td_vp_reserved); 2143 td->td_vp_reserved = NULL; 2144 } 2145 } 2146 2147 static void __noinline 2148 freevnode(struct vnode *vp) 2149 { 2150 struct bufobj *bo; 2151 2152 /* 2153 * The vnode has been marked for destruction, so free it. 2154 * 2155 * The vnode will be returned to the zone where it will 2156 * normally remain until it is needed for another vnode. We 2157 * need to cleanup (or verify that the cleanup has already 2158 * been done) any residual data left from its current use 2159 * so as not to contaminate the freshly allocated vnode. 2160 */ 2161 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 2162 /* 2163 * Paired with vgone. 2164 */ 2165 vn_seqc_write_end_free(vp); 2166 2167 bo = &vp->v_bufobj; 2168 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 2169 VNPASS(vp->v_holdcnt == VHOLD_NO_SMR, vp); 2170 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 2171 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 2172 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 2173 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 2174 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 2175 ("clean blk trie not empty")); 2176 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 2177 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 2178 ("dirty blk trie not empty")); 2179 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 2180 ("Dangling rangelock waiters")); 2181 VNASSERT((vp->v_iflag & (VI_DOINGINACT | VI_OWEINACT)) == 0, vp, 2182 ("Leaked inactivation")); 2183 VI_UNLOCK(vp); 2184 cache_assert_no_entries(vp); 2185 2186 #ifdef MAC 2187 mac_vnode_destroy(vp); 2188 #endif 2189 if (vp->v_pollinfo != NULL) { 2190 /* 2191 * Use LK_NOWAIT to shut up witness about the lock. We may get 2192 * here while having another vnode locked when trying to 2193 * satisfy a lookup and needing to recycle. 2194 */ 2195 VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT); 2196 destroy_vpollinfo(vp->v_pollinfo); 2197 VOP_UNLOCK(vp); 2198 vp->v_pollinfo = NULL; 2199 } 2200 vp->v_mountedhere = NULL; 2201 vp->v_unpcb = NULL; 2202 vp->v_rdev = NULL; 2203 vp->v_fifoinfo = NULL; 2204 vp->v_iflag = 0; 2205 vp->v_vflag = 0; 2206 bo->bo_flag = 0; 2207 vn_free(vp); 2208 } 2209 2210 /* 2211 * Delete from old mount point vnode list, if on one. 2212 */ 2213 static void 2214 delmntque(struct vnode *vp) 2215 { 2216 struct mount *mp; 2217 2218 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 2219 2220 mp = vp->v_mount; 2221 MNT_ILOCK(mp); 2222 VI_LOCK(vp); 2223 vp->v_mount = NULL; 2224 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 2225 ("bad mount point vnode list size")); 2226 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2227 mp->mnt_nvnodelistsize--; 2228 MNT_REL(mp); 2229 MNT_IUNLOCK(mp); 2230 /* 2231 * The caller expects the interlock to be still held. 2232 */ 2233 ASSERT_VI_LOCKED(vp, __func__); 2234 } 2235 2236 static int 2237 insmntque1_int(struct vnode *vp, struct mount *mp, bool dtr) 2238 { 2239 2240 KASSERT(vp->v_mount == NULL, 2241 ("insmntque: vnode already on per mount vnode list")); 2242 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 2243 if ((mp->mnt_kern_flag & MNTK_UNLOCKED_INSMNTQUE) == 0) { 2244 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 2245 } else { 2246 KASSERT(!dtr, 2247 ("%s: can't have MNTK_UNLOCKED_INSMNTQUE and cleanup", 2248 __func__)); 2249 } 2250 2251 /* 2252 * We acquire the vnode interlock early to ensure that the 2253 * vnode cannot be recycled by another process releasing a 2254 * holdcnt on it before we get it on both the vnode list 2255 * and the active vnode list. The mount mutex protects only 2256 * manipulation of the vnode list and the vnode freelist 2257 * mutex protects only manipulation of the active vnode list. 2258 * Hence the need to hold the vnode interlock throughout. 2259 */ 2260 MNT_ILOCK(mp); 2261 VI_LOCK(vp); 2262 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 2263 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 2264 mp->mnt_nvnodelistsize == 0)) && 2265 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 2266 VI_UNLOCK(vp); 2267 MNT_IUNLOCK(mp); 2268 if (dtr) { 2269 vp->v_data = NULL; 2270 vp->v_op = &dead_vnodeops; 2271 vgone(vp); 2272 vput(vp); 2273 } 2274 return (EBUSY); 2275 } 2276 vp->v_mount = mp; 2277 MNT_REF(mp); 2278 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2279 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 2280 ("neg mount point vnode list size")); 2281 mp->mnt_nvnodelistsize++; 2282 VI_UNLOCK(vp); 2283 MNT_IUNLOCK(mp); 2284 return (0); 2285 } 2286 2287 /* 2288 * Insert into list of vnodes for the new mount point, if available. 2289 * insmntque() reclaims the vnode on insertion failure, insmntque1() 2290 * leaves handling of the vnode to the caller. 2291 */ 2292 int 2293 insmntque(struct vnode *vp, struct mount *mp) 2294 { 2295 return (insmntque1_int(vp, mp, true)); 2296 } 2297 2298 int 2299 insmntque1(struct vnode *vp, struct mount *mp) 2300 { 2301 return (insmntque1_int(vp, mp, false)); 2302 } 2303 2304 /* 2305 * Flush out and invalidate all buffers associated with a bufobj 2306 * Called with the underlying object locked. 2307 */ 2308 int 2309 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 2310 { 2311 int error; 2312 2313 BO_LOCK(bo); 2314 if (flags & V_SAVE) { 2315 error = bufobj_wwait(bo, slpflag, slptimeo); 2316 if (error) { 2317 BO_UNLOCK(bo); 2318 return (error); 2319 } 2320 if (bo->bo_dirty.bv_cnt > 0) { 2321 BO_UNLOCK(bo); 2322 do { 2323 error = BO_SYNC(bo, MNT_WAIT); 2324 } while (error == ERELOOKUP); 2325 if (error != 0) 2326 return (error); 2327 BO_LOCK(bo); 2328 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) { 2329 BO_UNLOCK(bo); 2330 return (EBUSY); 2331 } 2332 } 2333 } 2334 /* 2335 * If you alter this loop please notice that interlock is dropped and 2336 * reacquired in flushbuflist. Special care is needed to ensure that 2337 * no race conditions occur from this. 2338 */ 2339 do { 2340 error = flushbuflist(&bo->bo_clean, 2341 flags, bo, slpflag, slptimeo); 2342 if (error == 0 && !(flags & V_CLEANONLY)) 2343 error = flushbuflist(&bo->bo_dirty, 2344 flags, bo, slpflag, slptimeo); 2345 if (error != 0 && error != EAGAIN) { 2346 BO_UNLOCK(bo); 2347 return (error); 2348 } 2349 } while (error != 0); 2350 2351 /* 2352 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 2353 * have write I/O in-progress but if there is a VM object then the 2354 * VM object can also have read-I/O in-progress. 2355 */ 2356 do { 2357 bufobj_wwait(bo, 0, 0); 2358 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 2359 BO_UNLOCK(bo); 2360 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 2361 BO_LOCK(bo); 2362 } 2363 } while (bo->bo_numoutput > 0); 2364 BO_UNLOCK(bo); 2365 2366 /* 2367 * Destroy the copy in the VM cache, too. 2368 */ 2369 if (bo->bo_object != NULL && 2370 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 2371 VM_OBJECT_WLOCK(bo->bo_object); 2372 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 2373 OBJPR_CLEANONLY : 0); 2374 VM_OBJECT_WUNLOCK(bo->bo_object); 2375 } 2376 2377 #ifdef INVARIANTS 2378 BO_LOCK(bo); 2379 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 2380 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 2381 bo->bo_clean.bv_cnt > 0)) 2382 panic("vinvalbuf: flush failed"); 2383 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 2384 bo->bo_dirty.bv_cnt > 0) 2385 panic("vinvalbuf: flush dirty failed"); 2386 BO_UNLOCK(bo); 2387 #endif 2388 return (0); 2389 } 2390 2391 /* 2392 * Flush out and invalidate all buffers associated with a vnode. 2393 * Called with the underlying object locked. 2394 */ 2395 int 2396 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 2397 { 2398 2399 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2400 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 2401 if (vp->v_object != NULL && vp->v_object->handle != vp) 2402 return (0); 2403 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 2404 } 2405 2406 /* 2407 * Flush out buffers on the specified list. 2408 * 2409 */ 2410 static int 2411 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 2412 int slptimeo) 2413 { 2414 struct buf *bp, *nbp; 2415 int retval, error; 2416 daddr_t lblkno; 2417 b_xflags_t xflags; 2418 2419 ASSERT_BO_WLOCKED(bo); 2420 2421 retval = 0; 2422 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 2423 /* 2424 * If we are flushing both V_NORMAL and V_ALT buffers then 2425 * do not skip any buffers. If we are flushing only V_NORMAL 2426 * buffers then skip buffers marked as BX_ALTDATA. If we are 2427 * flushing only V_ALT buffers then skip buffers not marked 2428 * as BX_ALTDATA. 2429 */ 2430 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 2431 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 2432 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 2433 continue; 2434 } 2435 if (nbp != NULL) { 2436 lblkno = nbp->b_lblkno; 2437 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 2438 } 2439 retval = EAGAIN; 2440 error = BUF_TIMELOCK(bp, 2441 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 2442 "flushbuf", slpflag, slptimeo); 2443 if (error) { 2444 BO_LOCK(bo); 2445 return (error != ENOLCK ? error : EAGAIN); 2446 } 2447 KASSERT(bp->b_bufobj == bo, 2448 ("bp %p wrong b_bufobj %p should be %p", 2449 bp, bp->b_bufobj, bo)); 2450 /* 2451 * XXX Since there are no node locks for NFS, I 2452 * believe there is a slight chance that a delayed 2453 * write will occur while sleeping just above, so 2454 * check for it. 2455 */ 2456 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 2457 (flags & V_SAVE)) { 2458 bremfree(bp); 2459 bp->b_flags |= B_ASYNC; 2460 bwrite(bp); 2461 BO_LOCK(bo); 2462 return (EAGAIN); /* XXX: why not loop ? */ 2463 } 2464 bremfree(bp); 2465 bp->b_flags |= (B_INVAL | B_RELBUF); 2466 bp->b_flags &= ~B_ASYNC; 2467 brelse(bp); 2468 BO_LOCK(bo); 2469 if (nbp == NULL) 2470 break; 2471 nbp = gbincore(bo, lblkno); 2472 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2473 != xflags) 2474 break; /* nbp invalid */ 2475 } 2476 return (retval); 2477 } 2478 2479 int 2480 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2481 { 2482 struct buf *bp; 2483 int error; 2484 daddr_t lblkno; 2485 2486 ASSERT_BO_LOCKED(bo); 2487 2488 for (lblkno = startn;;) { 2489 again: 2490 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2491 if (bp == NULL || bp->b_lblkno >= endn || 2492 bp->b_lblkno < startn) 2493 break; 2494 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2495 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2496 if (error != 0) { 2497 BO_RLOCK(bo); 2498 if (error == ENOLCK) 2499 goto again; 2500 return (error); 2501 } 2502 KASSERT(bp->b_bufobj == bo, 2503 ("bp %p wrong b_bufobj %p should be %p", 2504 bp, bp->b_bufobj, bo)); 2505 lblkno = bp->b_lblkno + 1; 2506 if ((bp->b_flags & B_MANAGED) == 0) 2507 bremfree(bp); 2508 bp->b_flags |= B_RELBUF; 2509 /* 2510 * In the VMIO case, use the B_NOREUSE flag to hint that the 2511 * pages backing each buffer in the range are unlikely to be 2512 * reused. Dirty buffers will have the hint applied once 2513 * they've been written. 2514 */ 2515 if ((bp->b_flags & B_VMIO) != 0) 2516 bp->b_flags |= B_NOREUSE; 2517 brelse(bp); 2518 BO_RLOCK(bo); 2519 } 2520 return (0); 2521 } 2522 2523 /* 2524 * Truncate a file's buffer and pages to a specified length. This 2525 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2526 * sync activity. 2527 */ 2528 int 2529 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2530 { 2531 struct buf *bp, *nbp; 2532 struct bufobj *bo; 2533 daddr_t startlbn; 2534 2535 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2536 vp, blksize, (uintmax_t)length); 2537 2538 /* 2539 * Round up to the *next* lbn. 2540 */ 2541 startlbn = howmany(length, blksize); 2542 2543 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2544 2545 bo = &vp->v_bufobj; 2546 restart_unlocked: 2547 BO_LOCK(bo); 2548 2549 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2550 ; 2551 2552 if (length > 0) { 2553 /* 2554 * Write out vnode metadata, e.g. indirect blocks. 2555 */ 2556 restartsync: 2557 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2558 if (bp->b_lblkno >= 0) 2559 continue; 2560 /* 2561 * Since we hold the vnode lock this should only 2562 * fail if we're racing with the buf daemon. 2563 */ 2564 if (BUF_LOCK(bp, 2565 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2566 BO_LOCKPTR(bo)) == ENOLCK) 2567 goto restart_unlocked; 2568 2569 VNASSERT((bp->b_flags & B_DELWRI), vp, 2570 ("buf(%p) on dirty queue without DELWRI", bp)); 2571 2572 bremfree(bp); 2573 bawrite(bp); 2574 BO_LOCK(bo); 2575 goto restartsync; 2576 } 2577 } 2578 2579 bufobj_wwait(bo, 0, 0); 2580 BO_UNLOCK(bo); 2581 vnode_pager_setsize(vp, length); 2582 2583 return (0); 2584 } 2585 2586 /* 2587 * Invalidate the cached pages of a file's buffer within the range of block 2588 * numbers [startlbn, endlbn). 2589 */ 2590 void 2591 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2592 int blksize) 2593 { 2594 struct bufobj *bo; 2595 off_t start, end; 2596 2597 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2598 2599 start = blksize * startlbn; 2600 end = blksize * endlbn; 2601 2602 bo = &vp->v_bufobj; 2603 BO_LOCK(bo); 2604 MPASS(blksize == bo->bo_bsize); 2605 2606 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2607 ; 2608 2609 BO_UNLOCK(bo); 2610 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2611 } 2612 2613 static int 2614 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2615 daddr_t startlbn, daddr_t endlbn) 2616 { 2617 struct buf *bp, *nbp; 2618 bool anyfreed; 2619 2620 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2621 ASSERT_BO_LOCKED(bo); 2622 2623 do { 2624 anyfreed = false; 2625 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2626 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2627 continue; 2628 if (BUF_LOCK(bp, 2629 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2630 BO_LOCKPTR(bo)) == ENOLCK) { 2631 BO_LOCK(bo); 2632 return (EAGAIN); 2633 } 2634 2635 bremfree(bp); 2636 bp->b_flags |= B_INVAL | B_RELBUF; 2637 bp->b_flags &= ~B_ASYNC; 2638 brelse(bp); 2639 anyfreed = true; 2640 2641 BO_LOCK(bo); 2642 if (nbp != NULL && 2643 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2644 nbp->b_vp != vp || 2645 (nbp->b_flags & B_DELWRI) != 0)) 2646 return (EAGAIN); 2647 } 2648 2649 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2650 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2651 continue; 2652 if (BUF_LOCK(bp, 2653 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2654 BO_LOCKPTR(bo)) == ENOLCK) { 2655 BO_LOCK(bo); 2656 return (EAGAIN); 2657 } 2658 bremfree(bp); 2659 bp->b_flags |= B_INVAL | B_RELBUF; 2660 bp->b_flags &= ~B_ASYNC; 2661 brelse(bp); 2662 anyfreed = true; 2663 2664 BO_LOCK(bo); 2665 if (nbp != NULL && 2666 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2667 (nbp->b_vp != vp) || 2668 (nbp->b_flags & B_DELWRI) == 0)) 2669 return (EAGAIN); 2670 } 2671 } while (anyfreed); 2672 return (0); 2673 } 2674 2675 static void 2676 buf_vlist_remove(struct buf *bp) 2677 { 2678 struct bufv *bv; 2679 b_xflags_t flags; 2680 2681 flags = bp->b_xflags; 2682 2683 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2684 ASSERT_BO_WLOCKED(bp->b_bufobj); 2685 KASSERT((flags & (BX_VNDIRTY | BX_VNCLEAN)) != 0 && 2686 (flags & (BX_VNDIRTY | BX_VNCLEAN)) != (BX_VNDIRTY | BX_VNCLEAN), 2687 ("%s: buffer %p has invalid queue state", __func__, bp)); 2688 2689 if ((flags & BX_VNDIRTY) != 0) 2690 bv = &bp->b_bufobj->bo_dirty; 2691 else 2692 bv = &bp->b_bufobj->bo_clean; 2693 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2694 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2695 bv->bv_cnt--; 2696 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2697 } 2698 2699 /* 2700 * Add the buffer to the sorted clean or dirty block list. Return zero on 2701 * success, EEXIST if a buffer with this identity already exists, or another 2702 * error on allocation failure. 2703 */ 2704 static inline int 2705 buf_vlist_find_or_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2706 { 2707 struct bufv *bv; 2708 struct buf *n; 2709 int error; 2710 2711 ASSERT_BO_WLOCKED(bo); 2712 KASSERT((bo->bo_flag & BO_NOBUFS) == 0, 2713 ("buf_vlist_add: bo %p does not allow bufs", bo)); 2714 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2715 ("dead bo %p", bo)); 2716 KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == xflags, 2717 ("buf_vlist_add: b_xflags %#x not set on bp %p", xflags, bp)); 2718 2719 if (xflags & BX_VNDIRTY) 2720 bv = &bo->bo_dirty; 2721 else 2722 bv = &bo->bo_clean; 2723 2724 error = BUF_PCTRIE_INSERT_LOOKUP_LE(&bv->bv_root, bp, &n); 2725 if (n == NULL) { 2726 KASSERT(error != EEXIST, 2727 ("buf_vlist_add: EEXIST but no existing buf found: bp %p", 2728 bp)); 2729 } else { 2730 KASSERT((uint64_t)n->b_lblkno <= (uint64_t)bp->b_lblkno, 2731 ("buf_vlist_add: out of order insert/lookup: bp %p n %p", 2732 bp, n)); 2733 KASSERT((n->b_lblkno == bp->b_lblkno) == (error == EEXIST), 2734 ("buf_vlist_add: inconsistent result for existing buf: " 2735 "error %d bp %p n %p", error, bp, n)); 2736 } 2737 if (error != 0) 2738 return (error); 2739 2740 /* Keep the list ordered. */ 2741 if (n == NULL) { 2742 KASSERT(TAILQ_EMPTY(&bv->bv_hd) || 2743 (uint64_t)bp->b_lblkno < 2744 (uint64_t)TAILQ_FIRST(&bv->bv_hd)->b_lblkno, 2745 ("buf_vlist_add: queue order: " 2746 "%p should be before first %p", 2747 bp, TAILQ_FIRST(&bv->bv_hd))); 2748 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2749 } else { 2750 KASSERT(TAILQ_NEXT(n, b_bobufs) == NULL || 2751 (uint64_t)bp->b_lblkno < 2752 (uint64_t)TAILQ_NEXT(n, b_bobufs)->b_lblkno, 2753 ("buf_vlist_add: queue order: " 2754 "%p should be before next %p", 2755 bp, TAILQ_NEXT(n, b_bobufs))); 2756 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2757 } 2758 2759 bv->bv_cnt++; 2760 return (0); 2761 } 2762 2763 /* 2764 * Add the buffer to the sorted clean or dirty block list. 2765 * 2766 * NOTE: xflags is passed as a constant, optimizing this inline function! 2767 */ 2768 static void 2769 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2770 { 2771 int error; 2772 2773 KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0, 2774 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2775 bp->b_xflags |= xflags; 2776 error = buf_vlist_find_or_add(bp, bo, xflags); 2777 if (error) 2778 panic("buf_vlist_add: error=%d", error); 2779 } 2780 2781 /* 2782 * Look up a buffer using the buffer tries. 2783 */ 2784 struct buf * 2785 gbincore(struct bufobj *bo, daddr_t lblkno) 2786 { 2787 struct buf *bp; 2788 2789 ASSERT_BO_LOCKED(bo); 2790 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2791 if (bp != NULL) 2792 return (bp); 2793 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno)); 2794 } 2795 2796 /* 2797 * Look up a buf using the buffer tries, without the bufobj lock. This relies 2798 * on SMR for safe lookup, and bufs being in a no-free zone to provide type 2799 * stability of the result. Like other lockless lookups, the found buf may 2800 * already be invalid by the time this function returns. 2801 */ 2802 struct buf * 2803 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno) 2804 { 2805 struct buf *bp; 2806 2807 ASSERT_BO_UNLOCKED(bo); 2808 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno); 2809 if (bp != NULL) 2810 return (bp); 2811 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno)); 2812 } 2813 2814 /* 2815 * Associate a buffer with a vnode. 2816 */ 2817 int 2818 bgetvp(struct vnode *vp, struct buf *bp) 2819 { 2820 struct bufobj *bo; 2821 int error; 2822 2823 bo = &vp->v_bufobj; 2824 ASSERT_BO_UNLOCKED(bo); 2825 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2826 2827 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2828 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2829 ("bgetvp: bp already attached! %p", bp)); 2830 2831 /* 2832 * Add the buf to the vnode's clean list unless we lost a race and find 2833 * an existing buf in either dirty or clean. 2834 */ 2835 bp->b_vp = vp; 2836 bp->b_bufobj = bo; 2837 bp->b_xflags |= BX_VNCLEAN; 2838 error = EEXIST; 2839 BO_LOCK(bo); 2840 if (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, bp->b_lblkno) == NULL) 2841 error = buf_vlist_find_or_add(bp, bo, BX_VNCLEAN); 2842 BO_UNLOCK(bo); 2843 if (__predict_true(error == 0)) { 2844 vhold(vp); 2845 return (0); 2846 } 2847 if (error != EEXIST) 2848 panic("bgetvp: buf_vlist_add error: %d", error); 2849 bp->b_vp = NULL; 2850 bp->b_bufobj = NULL; 2851 bp->b_xflags &= ~BX_VNCLEAN; 2852 return (error); 2853 } 2854 2855 /* 2856 * Disassociate a buffer from a vnode. 2857 */ 2858 void 2859 brelvp(struct buf *bp) 2860 { 2861 struct bufobj *bo; 2862 struct vnode *vp; 2863 2864 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2865 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2866 2867 /* 2868 * Delete from old vnode list, if on one. 2869 */ 2870 vp = bp->b_vp; /* XXX */ 2871 bo = bp->b_bufobj; 2872 BO_LOCK(bo); 2873 buf_vlist_remove(bp); 2874 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2875 bo->bo_flag &= ~BO_ONWORKLST; 2876 mtx_lock(&sync_mtx); 2877 LIST_REMOVE(bo, bo_synclist); 2878 syncer_worklist_len--; 2879 mtx_unlock(&sync_mtx); 2880 } 2881 bp->b_vp = NULL; 2882 bp->b_bufobj = NULL; 2883 BO_UNLOCK(bo); 2884 vdrop(vp); 2885 } 2886 2887 /* 2888 * Add an item to the syncer work queue. 2889 */ 2890 static void 2891 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2892 { 2893 int slot; 2894 2895 ASSERT_BO_WLOCKED(bo); 2896 2897 mtx_lock(&sync_mtx); 2898 if (bo->bo_flag & BO_ONWORKLST) 2899 LIST_REMOVE(bo, bo_synclist); 2900 else { 2901 bo->bo_flag |= BO_ONWORKLST; 2902 syncer_worklist_len++; 2903 } 2904 2905 if (delay > syncer_maxdelay - 2) 2906 delay = syncer_maxdelay - 2; 2907 slot = (syncer_delayno + delay) & syncer_mask; 2908 2909 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2910 mtx_unlock(&sync_mtx); 2911 } 2912 2913 static int 2914 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2915 { 2916 int error, len; 2917 2918 mtx_lock(&sync_mtx); 2919 len = syncer_worklist_len - sync_vnode_count; 2920 mtx_unlock(&sync_mtx); 2921 error = SYSCTL_OUT(req, &len, sizeof(len)); 2922 return (error); 2923 } 2924 2925 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2926 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2927 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2928 2929 static struct proc *updateproc; 2930 static void sched_sync(void); 2931 static struct kproc_desc up_kp = { 2932 "syncer", 2933 sched_sync, 2934 &updateproc 2935 }; 2936 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2937 2938 static int 2939 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2940 { 2941 struct vnode *vp; 2942 struct mount *mp; 2943 2944 *bo = LIST_FIRST(slp); 2945 if (*bo == NULL) 2946 return (0); 2947 vp = bo2vnode(*bo); 2948 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2949 return (1); 2950 /* 2951 * We use vhold in case the vnode does not 2952 * successfully sync. vhold prevents the vnode from 2953 * going away when we unlock the sync_mtx so that 2954 * we can acquire the vnode interlock. 2955 */ 2956 vholdl(vp); 2957 mtx_unlock(&sync_mtx); 2958 VI_UNLOCK(vp); 2959 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2960 vdrop(vp); 2961 mtx_lock(&sync_mtx); 2962 return (*bo == LIST_FIRST(slp)); 2963 } 2964 MPASSERT(mp == NULL || (curthread->td_pflags & TDP_IGNSUSP) != 0 || 2965 (mp->mnt_kern_flag & MNTK_SUSPENDED) == 0, mp, 2966 ("suspended mp syncing vp %p", vp)); 2967 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2968 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2969 VOP_UNLOCK(vp); 2970 vn_finished_write(mp); 2971 BO_LOCK(*bo); 2972 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2973 /* 2974 * Put us back on the worklist. The worklist 2975 * routine will remove us from our current 2976 * position and then add us back in at a later 2977 * position. 2978 */ 2979 vn_syncer_add_to_worklist(*bo, syncdelay); 2980 } 2981 BO_UNLOCK(*bo); 2982 vdrop(vp); 2983 mtx_lock(&sync_mtx); 2984 return (0); 2985 } 2986 2987 static int first_printf = 1; 2988 2989 /* 2990 * System filesystem synchronizer daemon. 2991 */ 2992 static void 2993 sched_sync(void) 2994 { 2995 struct synclist *next, *slp; 2996 struct bufobj *bo; 2997 long starttime; 2998 struct thread *td = curthread; 2999 int last_work_seen; 3000 int net_worklist_len; 3001 int syncer_final_iter; 3002 int error; 3003 3004 last_work_seen = 0; 3005 syncer_final_iter = 0; 3006 syncer_state = SYNCER_RUNNING; 3007 starttime = time_uptime; 3008 td->td_pflags |= TDP_NORUNNINGBUF; 3009 3010 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 3011 SHUTDOWN_PRI_LAST); 3012 3013 mtx_lock(&sync_mtx); 3014 for (;;) { 3015 if (syncer_state == SYNCER_FINAL_DELAY && 3016 syncer_final_iter == 0) { 3017 mtx_unlock(&sync_mtx); 3018 kproc_suspend_check(td->td_proc); 3019 mtx_lock(&sync_mtx); 3020 } 3021 net_worklist_len = syncer_worklist_len - sync_vnode_count; 3022 if (syncer_state != SYNCER_RUNNING && 3023 starttime != time_uptime) { 3024 if (first_printf) { 3025 printf("\nSyncing disks, vnodes remaining... "); 3026 first_printf = 0; 3027 } 3028 printf("%d ", net_worklist_len); 3029 } 3030 starttime = time_uptime; 3031 3032 /* 3033 * Push files whose dirty time has expired. Be careful 3034 * of interrupt race on slp queue. 3035 * 3036 * Skip over empty worklist slots when shutting down. 3037 */ 3038 do { 3039 slp = &syncer_workitem_pending[syncer_delayno]; 3040 syncer_delayno += 1; 3041 if (syncer_delayno == syncer_maxdelay) 3042 syncer_delayno = 0; 3043 next = &syncer_workitem_pending[syncer_delayno]; 3044 /* 3045 * If the worklist has wrapped since the 3046 * it was emptied of all but syncer vnodes, 3047 * switch to the FINAL_DELAY state and run 3048 * for one more second. 3049 */ 3050 if (syncer_state == SYNCER_SHUTTING_DOWN && 3051 net_worklist_len == 0 && 3052 last_work_seen == syncer_delayno) { 3053 syncer_state = SYNCER_FINAL_DELAY; 3054 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 3055 } 3056 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 3057 syncer_worklist_len > 0); 3058 3059 /* 3060 * Keep track of the last time there was anything 3061 * on the worklist other than syncer vnodes. 3062 * Return to the SHUTTING_DOWN state if any 3063 * new work appears. 3064 */ 3065 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 3066 last_work_seen = syncer_delayno; 3067 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 3068 syncer_state = SYNCER_SHUTTING_DOWN; 3069 while (!LIST_EMPTY(slp)) { 3070 error = sync_vnode(slp, &bo, td); 3071 if (error == 1) { 3072 LIST_REMOVE(bo, bo_synclist); 3073 LIST_INSERT_HEAD(next, bo, bo_synclist); 3074 continue; 3075 } 3076 3077 if (first_printf == 0) { 3078 /* 3079 * Drop the sync mutex, because some watchdog 3080 * drivers need to sleep while patting 3081 */ 3082 mtx_unlock(&sync_mtx); 3083 wdog_kern_pat(WD_LASTVAL); 3084 mtx_lock(&sync_mtx); 3085 } 3086 } 3087 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 3088 syncer_final_iter--; 3089 /* 3090 * The variable rushjob allows the kernel to speed up the 3091 * processing of the filesystem syncer process. A rushjob 3092 * value of N tells the filesystem syncer to process the next 3093 * N seconds worth of work on its queue ASAP. Currently rushjob 3094 * is used by the soft update code to speed up the filesystem 3095 * syncer process when the incore state is getting so far 3096 * ahead of the disk that the kernel memory pool is being 3097 * threatened with exhaustion. 3098 */ 3099 if (rushjob > 0) { 3100 rushjob -= 1; 3101 continue; 3102 } 3103 /* 3104 * Just sleep for a short period of time between 3105 * iterations when shutting down to allow some I/O 3106 * to happen. 3107 * 3108 * If it has taken us less than a second to process the 3109 * current work, then wait. Otherwise start right over 3110 * again. We can still lose time if any single round 3111 * takes more than two seconds, but it does not really 3112 * matter as we are just trying to generally pace the 3113 * filesystem activity. 3114 */ 3115 if (syncer_state != SYNCER_RUNNING || 3116 time_uptime == starttime) { 3117 thread_lock(td); 3118 sched_prio(td, PPAUSE); 3119 thread_unlock(td); 3120 } 3121 if (syncer_state != SYNCER_RUNNING) 3122 cv_timedwait(&sync_wakeup, &sync_mtx, 3123 hz / SYNCER_SHUTDOWN_SPEEDUP); 3124 else if (time_uptime == starttime) 3125 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 3126 } 3127 } 3128 3129 /* 3130 * Request the syncer daemon to speed up its work. 3131 * We never push it to speed up more than half of its 3132 * normal turn time, otherwise it could take over the cpu. 3133 */ 3134 int 3135 speedup_syncer(void) 3136 { 3137 int ret = 0; 3138 3139 mtx_lock(&sync_mtx); 3140 if (rushjob < syncdelay / 2) { 3141 rushjob += 1; 3142 stat_rush_requests += 1; 3143 ret = 1; 3144 } 3145 mtx_unlock(&sync_mtx); 3146 cv_broadcast(&sync_wakeup); 3147 return (ret); 3148 } 3149 3150 /* 3151 * Tell the syncer to speed up its work and run though its work 3152 * list several times, then tell it to shut down. 3153 */ 3154 static void 3155 syncer_shutdown(void *arg, int howto) 3156 { 3157 3158 if (howto & RB_NOSYNC) 3159 return; 3160 mtx_lock(&sync_mtx); 3161 syncer_state = SYNCER_SHUTTING_DOWN; 3162 rushjob = 0; 3163 mtx_unlock(&sync_mtx); 3164 cv_broadcast(&sync_wakeup); 3165 kproc_shutdown(arg, howto); 3166 } 3167 3168 void 3169 syncer_suspend(void) 3170 { 3171 3172 syncer_shutdown(updateproc, 0); 3173 } 3174 3175 void 3176 syncer_resume(void) 3177 { 3178 3179 mtx_lock(&sync_mtx); 3180 first_printf = 1; 3181 syncer_state = SYNCER_RUNNING; 3182 mtx_unlock(&sync_mtx); 3183 cv_broadcast(&sync_wakeup); 3184 kproc_resume(updateproc); 3185 } 3186 3187 /* 3188 * Move the buffer between the clean and dirty lists of its vnode. 3189 */ 3190 void 3191 reassignbuf(struct buf *bp) 3192 { 3193 struct vnode *vp; 3194 struct bufobj *bo; 3195 int delay; 3196 #ifdef INVARIANTS 3197 struct bufv *bv; 3198 #endif 3199 3200 vp = bp->b_vp; 3201 bo = bp->b_bufobj; 3202 3203 KASSERT((bp->b_flags & B_PAGING) == 0, 3204 ("%s: cannot reassign paging buffer %p", __func__, bp)); 3205 3206 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 3207 bp, bp->b_vp, bp->b_flags); 3208 3209 BO_LOCK(bo); 3210 if ((bo->bo_flag & BO_NONSTERILE) == 0) { 3211 /* 3212 * Coordinate with getblk's unlocked lookup. Make 3213 * BO_NONSTERILE visible before the first reassignbuf produces 3214 * any side effect. This could be outside the bo lock if we 3215 * used a separate atomic flag field. 3216 */ 3217 bo->bo_flag |= BO_NONSTERILE; 3218 atomic_thread_fence_rel(); 3219 } 3220 buf_vlist_remove(bp); 3221 3222 /* 3223 * If dirty, put on list of dirty buffers; otherwise insert onto list 3224 * of clean buffers. 3225 */ 3226 if (bp->b_flags & B_DELWRI) { 3227 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 3228 switch (vp->v_type) { 3229 case VDIR: 3230 delay = dirdelay; 3231 break; 3232 case VCHR: 3233 delay = metadelay; 3234 break; 3235 default: 3236 delay = filedelay; 3237 } 3238 vn_syncer_add_to_worklist(bo, delay); 3239 } 3240 buf_vlist_add(bp, bo, BX_VNDIRTY); 3241 } else { 3242 buf_vlist_add(bp, bo, BX_VNCLEAN); 3243 3244 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 3245 mtx_lock(&sync_mtx); 3246 LIST_REMOVE(bo, bo_synclist); 3247 syncer_worklist_len--; 3248 mtx_unlock(&sync_mtx); 3249 bo->bo_flag &= ~BO_ONWORKLST; 3250 } 3251 } 3252 #ifdef INVARIANTS 3253 bv = &bo->bo_clean; 3254 bp = TAILQ_FIRST(&bv->bv_hd); 3255 KASSERT(bp == NULL || bp->b_bufobj == bo, 3256 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 3257 bp = TAILQ_LAST(&bv->bv_hd, buflists); 3258 KASSERT(bp == NULL || bp->b_bufobj == bo, 3259 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 3260 bv = &bo->bo_dirty; 3261 bp = TAILQ_FIRST(&bv->bv_hd); 3262 KASSERT(bp == NULL || bp->b_bufobj == bo, 3263 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 3264 bp = TAILQ_LAST(&bv->bv_hd, buflists); 3265 KASSERT(bp == NULL || bp->b_bufobj == bo, 3266 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 3267 #endif 3268 BO_UNLOCK(bo); 3269 } 3270 3271 static void 3272 v_init_counters(struct vnode *vp) 3273 { 3274 3275 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 3276 vp, ("%s called for an initialized vnode", __FUNCTION__)); 3277 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 3278 3279 refcount_init(&vp->v_holdcnt, 1); 3280 refcount_init(&vp->v_usecount, 1); 3281 } 3282 3283 /* 3284 * Get a usecount on a vnode. 3285 * 3286 * vget and vget_finish may fail to lock the vnode if they lose a race against 3287 * it being doomed. LK_RETRY can be passed in flags to lock it anyway. 3288 * 3289 * Consumers which don't guarantee liveness of the vnode can use SMR to 3290 * try to get a reference. Note this operation can fail since the vnode 3291 * may be awaiting getting freed by the time they get to it. 3292 */ 3293 enum vgetstate 3294 vget_prep_smr(struct vnode *vp) 3295 { 3296 enum vgetstate vs; 3297 3298 VFS_SMR_ASSERT_ENTERED(); 3299 3300 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3301 vs = VGET_USECOUNT; 3302 } else { 3303 if (vhold_smr(vp)) 3304 vs = VGET_HOLDCNT; 3305 else 3306 vs = VGET_NONE; 3307 } 3308 return (vs); 3309 } 3310 3311 enum vgetstate 3312 vget_prep(struct vnode *vp) 3313 { 3314 enum vgetstate vs; 3315 3316 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3317 vs = VGET_USECOUNT; 3318 } else { 3319 vhold(vp); 3320 vs = VGET_HOLDCNT; 3321 } 3322 return (vs); 3323 } 3324 3325 void 3326 vget_abort(struct vnode *vp, enum vgetstate vs) 3327 { 3328 3329 switch (vs) { 3330 case VGET_USECOUNT: 3331 vrele(vp); 3332 break; 3333 case VGET_HOLDCNT: 3334 vdrop(vp); 3335 break; 3336 default: 3337 __assert_unreachable(); 3338 } 3339 } 3340 3341 int 3342 vget(struct vnode *vp, int flags) 3343 { 3344 enum vgetstate vs; 3345 3346 vs = vget_prep(vp); 3347 return (vget_finish(vp, flags, vs)); 3348 } 3349 3350 int 3351 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 3352 { 3353 int error; 3354 3355 if ((flags & LK_INTERLOCK) != 0) 3356 ASSERT_VI_LOCKED(vp, __func__); 3357 else 3358 ASSERT_VI_UNLOCKED(vp, __func__); 3359 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 3360 VNPASS(vp->v_holdcnt > 0, vp); 3361 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 3362 3363 error = vn_lock(vp, flags); 3364 if (__predict_false(error != 0)) { 3365 vget_abort(vp, vs); 3366 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 3367 vp); 3368 return (error); 3369 } 3370 3371 vget_finish_ref(vp, vs); 3372 return (0); 3373 } 3374 3375 void 3376 vget_finish_ref(struct vnode *vp, enum vgetstate vs) 3377 { 3378 int old; 3379 3380 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 3381 VNPASS(vp->v_holdcnt > 0, vp); 3382 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 3383 3384 if (vs == VGET_USECOUNT) 3385 return; 3386 3387 /* 3388 * We hold the vnode. If the usecount is 0 it will be utilized to keep 3389 * the vnode around. Otherwise someone else lended their hold count and 3390 * we have to drop ours. 3391 */ 3392 old = atomic_fetchadd_int(&vp->v_usecount, 1); 3393 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 3394 if (old != 0) { 3395 #ifdef INVARIANTS 3396 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 3397 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 3398 #else 3399 refcount_release(&vp->v_holdcnt); 3400 #endif 3401 } 3402 } 3403 3404 void 3405 vref(struct vnode *vp) 3406 { 3407 enum vgetstate vs; 3408 3409 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3410 vs = vget_prep(vp); 3411 vget_finish_ref(vp, vs); 3412 } 3413 3414 void 3415 vrefact(struct vnode *vp) 3416 { 3417 int old __diagused; 3418 3419 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3420 old = refcount_acquire(&vp->v_usecount); 3421 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3422 } 3423 3424 void 3425 vlazy(struct vnode *vp) 3426 { 3427 struct mount *mp; 3428 3429 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 3430 3431 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 3432 return; 3433 /* 3434 * We may get here for inactive routines after the vnode got doomed. 3435 */ 3436 if (VN_IS_DOOMED(vp)) 3437 return; 3438 mp = vp->v_mount; 3439 mtx_lock(&mp->mnt_listmtx); 3440 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 3441 vp->v_mflag |= VMP_LAZYLIST; 3442 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3443 mp->mnt_lazyvnodelistsize++; 3444 } 3445 mtx_unlock(&mp->mnt_listmtx); 3446 } 3447 3448 static void 3449 vunlazy(struct vnode *vp) 3450 { 3451 struct mount *mp; 3452 3453 ASSERT_VI_LOCKED(vp, __func__); 3454 VNPASS(!VN_IS_DOOMED(vp), vp); 3455 3456 mp = vp->v_mount; 3457 mtx_lock(&mp->mnt_listmtx); 3458 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3459 /* 3460 * Don't remove the vnode from the lazy list if another thread 3461 * has increased the hold count. It may have re-enqueued the 3462 * vnode to the lazy list and is now responsible for its 3463 * removal. 3464 */ 3465 if (vp->v_holdcnt == 0) { 3466 vp->v_mflag &= ~VMP_LAZYLIST; 3467 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3468 mp->mnt_lazyvnodelistsize--; 3469 } 3470 mtx_unlock(&mp->mnt_listmtx); 3471 } 3472 3473 /* 3474 * This routine is only meant to be called from vgonel prior to dooming 3475 * the vnode. 3476 */ 3477 static void 3478 vunlazy_gone(struct vnode *vp) 3479 { 3480 struct mount *mp; 3481 3482 ASSERT_VOP_ELOCKED(vp, __func__); 3483 ASSERT_VI_LOCKED(vp, __func__); 3484 VNPASS(!VN_IS_DOOMED(vp), vp); 3485 3486 if (vp->v_mflag & VMP_LAZYLIST) { 3487 mp = vp->v_mount; 3488 mtx_lock(&mp->mnt_listmtx); 3489 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3490 vp->v_mflag &= ~VMP_LAZYLIST; 3491 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3492 mp->mnt_lazyvnodelistsize--; 3493 mtx_unlock(&mp->mnt_listmtx); 3494 } 3495 } 3496 3497 static void 3498 vdefer_inactive(struct vnode *vp) 3499 { 3500 3501 ASSERT_VI_LOCKED(vp, __func__); 3502 VNPASS(vp->v_holdcnt > 0, vp); 3503 if (VN_IS_DOOMED(vp)) { 3504 vdropl(vp); 3505 return; 3506 } 3507 if (vp->v_iflag & VI_DEFINACT) { 3508 VNPASS(vp->v_holdcnt > 1, vp); 3509 vdropl(vp); 3510 return; 3511 } 3512 if (vp->v_usecount > 0) { 3513 vp->v_iflag &= ~VI_OWEINACT; 3514 vdropl(vp); 3515 return; 3516 } 3517 vlazy(vp); 3518 vp->v_iflag |= VI_DEFINACT; 3519 VI_UNLOCK(vp); 3520 atomic_add_long(&deferred_inact, 1); 3521 } 3522 3523 static void 3524 vdefer_inactive_unlocked(struct vnode *vp) 3525 { 3526 3527 VI_LOCK(vp); 3528 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3529 vdropl(vp); 3530 return; 3531 } 3532 vdefer_inactive(vp); 3533 } 3534 3535 enum vput_op { VRELE, VPUT, VUNREF }; 3536 3537 /* 3538 * Handle ->v_usecount transitioning to 0. 3539 * 3540 * By releasing the last usecount we take ownership of the hold count which 3541 * provides liveness of the vnode, meaning we have to vdrop. 3542 * 3543 * For all vnodes we may need to perform inactive processing. It requires an 3544 * exclusive lock on the vnode, while it is legal to call here with only a 3545 * shared lock (or no locks). If locking the vnode in an expected manner fails, 3546 * inactive processing gets deferred to the syncer. 3547 * 3548 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3549 * on the lock being held all the way until VOP_INACTIVE. This in particular 3550 * happens with UFS which adds half-constructed vnodes to the hash, where they 3551 * can be found by other code. 3552 */ 3553 static void 3554 vput_final(struct vnode *vp, enum vput_op func) 3555 { 3556 int error; 3557 bool want_unlock; 3558 3559 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3560 VNPASS(vp->v_holdcnt > 0, vp); 3561 3562 VI_LOCK(vp); 3563 3564 /* 3565 * By the time we got here someone else might have transitioned 3566 * the count back to > 0. 3567 */ 3568 if (vp->v_usecount > 0) 3569 goto out; 3570 3571 /* 3572 * If the vnode is doomed vgone already performed inactive processing 3573 * (if needed). 3574 */ 3575 if (VN_IS_DOOMED(vp)) 3576 goto out; 3577 3578 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0)) 3579 goto out; 3580 3581 if (vp->v_iflag & VI_DOINGINACT) 3582 goto out; 3583 3584 /* 3585 * Locking operations here will drop the interlock and possibly the 3586 * vnode lock, opening a window where the vnode can get doomed all the 3587 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to 3588 * perform inactive. 3589 */ 3590 vp->v_iflag |= VI_OWEINACT; 3591 want_unlock = false; 3592 error = 0; 3593 switch (func) { 3594 case VRELE: 3595 switch (VOP_ISLOCKED(vp)) { 3596 case LK_EXCLUSIVE: 3597 break; 3598 case LK_EXCLOTHER: 3599 case 0: 3600 want_unlock = true; 3601 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3602 VI_LOCK(vp); 3603 break; 3604 default: 3605 /* 3606 * The lock has at least one sharer, but we have no way 3607 * to conclude whether this is us. Play it safe and 3608 * defer processing. 3609 */ 3610 error = EAGAIN; 3611 break; 3612 } 3613 break; 3614 case VPUT: 3615 want_unlock = true; 3616 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3617 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3618 LK_NOWAIT); 3619 VI_LOCK(vp); 3620 } 3621 break; 3622 case VUNREF: 3623 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3624 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3625 VI_LOCK(vp); 3626 } 3627 break; 3628 } 3629 if (error == 0) { 3630 if (func == VUNREF) { 3631 VNASSERT((vp->v_vflag & VV_UNREF) == 0, vp, 3632 ("recursive vunref")); 3633 vp->v_vflag |= VV_UNREF; 3634 } 3635 for (;;) { 3636 error = vinactive(vp); 3637 if (want_unlock) 3638 VOP_UNLOCK(vp); 3639 if (error != ERELOOKUP || !want_unlock) 3640 break; 3641 VOP_LOCK(vp, LK_EXCLUSIVE); 3642 } 3643 if (func == VUNREF) 3644 vp->v_vflag &= ~VV_UNREF; 3645 vdropl(vp); 3646 } else { 3647 vdefer_inactive(vp); 3648 } 3649 return; 3650 out: 3651 if (func == VPUT) 3652 VOP_UNLOCK(vp); 3653 vdropl(vp); 3654 } 3655 3656 /* 3657 * Decrement ->v_usecount for a vnode. 3658 * 3659 * Releasing the last use count requires additional processing, see vput_final 3660 * above for details. 3661 * 3662 * Comment above each variant denotes lock state on entry and exit. 3663 */ 3664 3665 /* 3666 * in: any 3667 * out: same as passed in 3668 */ 3669 void 3670 vrele(struct vnode *vp) 3671 { 3672 3673 ASSERT_VI_UNLOCKED(vp, __func__); 3674 if (!refcount_release(&vp->v_usecount)) 3675 return; 3676 vput_final(vp, VRELE); 3677 } 3678 3679 /* 3680 * in: locked 3681 * out: unlocked 3682 */ 3683 void 3684 vput(struct vnode *vp) 3685 { 3686 3687 ASSERT_VOP_LOCKED(vp, __func__); 3688 ASSERT_VI_UNLOCKED(vp, __func__); 3689 if (!refcount_release(&vp->v_usecount)) { 3690 VOP_UNLOCK(vp); 3691 return; 3692 } 3693 vput_final(vp, VPUT); 3694 } 3695 3696 /* 3697 * in: locked 3698 * out: locked 3699 */ 3700 void 3701 vunref(struct vnode *vp) 3702 { 3703 3704 ASSERT_VOP_LOCKED(vp, __func__); 3705 ASSERT_VI_UNLOCKED(vp, __func__); 3706 if (!refcount_release(&vp->v_usecount)) 3707 return; 3708 vput_final(vp, VUNREF); 3709 } 3710 3711 void 3712 vhold(struct vnode *vp) 3713 { 3714 int old; 3715 3716 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3717 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3718 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3719 ("%s: wrong hold count %d", __func__, old)); 3720 if (old == 0) 3721 vfs_freevnodes_dec(); 3722 } 3723 3724 void 3725 vholdnz(struct vnode *vp) 3726 { 3727 3728 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3729 #ifdef INVARIANTS 3730 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3731 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3732 ("%s: wrong hold count %d", __func__, old)); 3733 #else 3734 atomic_add_int(&vp->v_holdcnt, 1); 3735 #endif 3736 } 3737 3738 /* 3739 * Grab a hold count unless the vnode is freed. 3740 * 3741 * Only use this routine if vfs smr is the only protection you have against 3742 * freeing the vnode. 3743 * 3744 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag 3745 * is not set. After the flag is set the vnode becomes immutable to anyone but 3746 * the thread which managed to set the flag. 3747 * 3748 * It may be tempting to replace the loop with: 3749 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3750 * if (count & VHOLD_NO_SMR) { 3751 * backpedal and error out; 3752 * } 3753 * 3754 * However, while this is more performant, it hinders debugging by eliminating 3755 * the previously mentioned invariant. 3756 */ 3757 bool 3758 vhold_smr(struct vnode *vp) 3759 { 3760 int count; 3761 3762 VFS_SMR_ASSERT_ENTERED(); 3763 3764 count = atomic_load_int(&vp->v_holdcnt); 3765 for (;;) { 3766 if (count & VHOLD_NO_SMR) { 3767 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3768 ("non-zero hold count with flags %d\n", count)); 3769 return (false); 3770 } 3771 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3772 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) { 3773 if (count == 0) 3774 vfs_freevnodes_dec(); 3775 return (true); 3776 } 3777 } 3778 } 3779 3780 /* 3781 * Hold a free vnode for recycling. 3782 * 3783 * Note: vnode_init references this comment. 3784 * 3785 * Attempts to recycle only need the global vnode list lock and have no use for 3786 * SMR. 3787 * 3788 * However, vnodes get inserted into the global list before they get fully 3789 * initialized and stay there until UMA decides to free the memory. This in 3790 * particular means the target can be found before it becomes usable and after 3791 * it becomes recycled. Picking up such vnodes is guarded with v_holdcnt set to 3792 * VHOLD_NO_SMR. 3793 * 3794 * Note: the vnode may gain more references after we transition the count 0->1. 3795 */ 3796 static bool 3797 vhold_recycle_free(struct vnode *vp) 3798 { 3799 int count; 3800 3801 mtx_assert(&vnode_list_mtx, MA_OWNED); 3802 3803 count = atomic_load_int(&vp->v_holdcnt); 3804 for (;;) { 3805 if (count & VHOLD_NO_SMR) { 3806 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3807 ("non-zero hold count with flags %d\n", count)); 3808 return (false); 3809 } 3810 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3811 if (count > 0) { 3812 return (false); 3813 } 3814 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) { 3815 vfs_freevnodes_dec(); 3816 return (true); 3817 } 3818 } 3819 } 3820 3821 static void __noinline 3822 vdbatch_process(struct vdbatch *vd) 3823 { 3824 struct vnode *vp; 3825 int i; 3826 3827 mtx_assert(&vd->lock, MA_OWNED); 3828 MPASS(curthread->td_pinned > 0); 3829 MPASS(vd->index == VDBATCH_SIZE); 3830 3831 /* 3832 * Attempt to requeue the passed batch, but give up easily. 3833 * 3834 * Despite batching the mechanism is prone to transient *significant* 3835 * lock contention, where vnode_list_mtx becomes the primary bottleneck 3836 * if multiple CPUs get here (one real-world example is highly parallel 3837 * do-nothing make , which will stat *tons* of vnodes). Since it is 3838 * quasi-LRU (read: not that great even if fully honoured) just dodge 3839 * the problem. Parties which don't like it are welcome to implement 3840 * something better. 3841 */ 3842 critical_enter(); 3843 if (mtx_trylock(&vnode_list_mtx)) { 3844 for (i = 0; i < VDBATCH_SIZE; i++) { 3845 vp = vd->tab[i]; 3846 vd->tab[i] = NULL; 3847 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3848 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3849 MPASS(vp->v_dbatchcpu != NOCPU); 3850 vp->v_dbatchcpu = NOCPU; 3851 } 3852 mtx_unlock(&vnode_list_mtx); 3853 } else { 3854 counter_u64_add(vnode_skipped_requeues, 1); 3855 3856 for (i = 0; i < VDBATCH_SIZE; i++) { 3857 vp = vd->tab[i]; 3858 vd->tab[i] = NULL; 3859 MPASS(vp->v_dbatchcpu != NOCPU); 3860 vp->v_dbatchcpu = NOCPU; 3861 } 3862 } 3863 vd->index = 0; 3864 critical_exit(); 3865 } 3866 3867 static void 3868 vdbatch_enqueue(struct vnode *vp) 3869 { 3870 struct vdbatch *vd; 3871 3872 ASSERT_VI_LOCKED(vp, __func__); 3873 VNPASS(!VN_IS_DOOMED(vp), vp); 3874 3875 if (vp->v_dbatchcpu != NOCPU) { 3876 VI_UNLOCK(vp); 3877 return; 3878 } 3879 3880 sched_pin(); 3881 vd = DPCPU_PTR(vd); 3882 mtx_lock(&vd->lock); 3883 MPASS(vd->index < VDBATCH_SIZE); 3884 MPASS(vd->tab[vd->index] == NULL); 3885 /* 3886 * A hack: we depend on being pinned so that we know what to put in 3887 * ->v_dbatchcpu. 3888 */ 3889 vp->v_dbatchcpu = curcpu; 3890 vd->tab[vd->index] = vp; 3891 vd->index++; 3892 VI_UNLOCK(vp); 3893 if (vd->index == VDBATCH_SIZE) 3894 vdbatch_process(vd); 3895 mtx_unlock(&vd->lock); 3896 sched_unpin(); 3897 } 3898 3899 /* 3900 * This routine must only be called for vnodes which are about to be 3901 * deallocated. Supporting dequeue for arbitrary vndoes would require 3902 * validating that the locked batch matches. 3903 */ 3904 static void 3905 vdbatch_dequeue(struct vnode *vp) 3906 { 3907 struct vdbatch *vd; 3908 int i; 3909 short cpu; 3910 3911 VNPASS(vp->v_type == VBAD || vp->v_type == VNON, vp); 3912 3913 cpu = vp->v_dbatchcpu; 3914 if (cpu == NOCPU) 3915 return; 3916 3917 vd = DPCPU_ID_PTR(cpu, vd); 3918 mtx_lock(&vd->lock); 3919 for (i = 0; i < vd->index; i++) { 3920 if (vd->tab[i] != vp) 3921 continue; 3922 vp->v_dbatchcpu = NOCPU; 3923 vd->index--; 3924 vd->tab[i] = vd->tab[vd->index]; 3925 vd->tab[vd->index] = NULL; 3926 break; 3927 } 3928 mtx_unlock(&vd->lock); 3929 /* 3930 * Either we dequeued the vnode above or the target CPU beat us to it. 3931 */ 3932 MPASS(vp->v_dbatchcpu == NOCPU); 3933 } 3934 3935 /* 3936 * Drop the hold count of the vnode. 3937 * 3938 * It will only get freed if this is the last hold *and* it has been vgone'd. 3939 * 3940 * Because the vnode vm object keeps a hold reference on the vnode if 3941 * there is at least one resident non-cached page, the vnode cannot 3942 * leave the active list without the page cleanup done. 3943 */ 3944 static void __noinline 3945 vdropl_final(struct vnode *vp) 3946 { 3947 3948 ASSERT_VI_LOCKED(vp, __func__); 3949 VNPASS(VN_IS_DOOMED(vp), vp); 3950 /* 3951 * Set the VHOLD_NO_SMR flag. 3952 * 3953 * We may be racing against vhold_smr. If they win we can just pretend 3954 * we never got this far, they will vdrop later. 3955 */ 3956 if (__predict_false(!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR))) { 3957 vfs_freevnodes_inc(); 3958 VI_UNLOCK(vp); 3959 /* 3960 * We lost the aforementioned race. Any subsequent access is 3961 * invalid as they might have managed to vdropl on their own. 3962 */ 3963 return; 3964 } 3965 /* 3966 * Don't bump freevnodes as this one is going away. 3967 */ 3968 freevnode(vp); 3969 } 3970 3971 void 3972 vdrop(struct vnode *vp) 3973 { 3974 3975 ASSERT_VI_UNLOCKED(vp, __func__); 3976 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3977 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3978 return; 3979 VI_LOCK(vp); 3980 vdropl(vp); 3981 } 3982 3983 static __always_inline void 3984 vdropl_impl(struct vnode *vp, bool enqueue) 3985 { 3986 3987 ASSERT_VI_LOCKED(vp, __func__); 3988 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3989 if (!refcount_release(&vp->v_holdcnt)) { 3990 VI_UNLOCK(vp); 3991 return; 3992 } 3993 VNPASS((vp->v_iflag & VI_OWEINACT) == 0, vp); 3994 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp); 3995 if (VN_IS_DOOMED(vp)) { 3996 vdropl_final(vp); 3997 return; 3998 } 3999 4000 vfs_freevnodes_inc(); 4001 if (vp->v_mflag & VMP_LAZYLIST) { 4002 vunlazy(vp); 4003 } 4004 4005 if (!enqueue) { 4006 VI_UNLOCK(vp); 4007 return; 4008 } 4009 4010 /* 4011 * Also unlocks the interlock. We can't assert on it as we 4012 * released our hold and by now the vnode might have been 4013 * freed. 4014 */ 4015 vdbatch_enqueue(vp); 4016 } 4017 4018 void 4019 vdropl(struct vnode *vp) 4020 { 4021 4022 vdropl_impl(vp, true); 4023 } 4024 4025 /* 4026 * vdrop a vnode when recycling 4027 * 4028 * This is a special case routine only to be used when recycling, differs from 4029 * regular vdrop by not requeieing the vnode on LRU. 4030 * 4031 * Consider a case where vtryrecycle continuously fails with all vnodes (due to 4032 * e.g., frozen writes on the filesystem), filling the batch and causing it to 4033 * be requeued. Then vnlru will end up revisiting the same vnodes. This is a 4034 * loop which can last for as long as writes are frozen. 4035 */ 4036 static void 4037 vdropl_recycle(struct vnode *vp) 4038 { 4039 4040 vdropl_impl(vp, false); 4041 } 4042 4043 static void 4044 vdrop_recycle(struct vnode *vp) 4045 { 4046 4047 VI_LOCK(vp); 4048 vdropl_recycle(vp); 4049 } 4050 4051 /* 4052 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 4053 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 4054 */ 4055 static int 4056 vinactivef(struct vnode *vp) 4057 { 4058 int error; 4059 4060 ASSERT_VOP_ELOCKED(vp, "vinactive"); 4061 ASSERT_VI_LOCKED(vp, "vinactive"); 4062 VNPASS((vp->v_iflag & VI_DOINGINACT) == 0, vp); 4063 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 4064 vp->v_iflag |= VI_DOINGINACT; 4065 vp->v_iflag &= ~VI_OWEINACT; 4066 VI_UNLOCK(vp); 4067 4068 /* 4069 * Before moving off the active list, we must be sure that any 4070 * modified pages are converted into the vnode's dirty 4071 * buffers, since these will no longer be checked once the 4072 * vnode is on the inactive list. 4073 * 4074 * The write-out of the dirty pages is asynchronous. At the 4075 * point that VOP_INACTIVE() is called, there could still be 4076 * pending I/O and dirty pages in the object. 4077 */ 4078 if ((vp->v_vflag & VV_NOSYNC) == 0) 4079 vnode_pager_clean_async(vp); 4080 4081 error = VOP_INACTIVE(vp); 4082 VI_LOCK(vp); 4083 VNPASS(vp->v_iflag & VI_DOINGINACT, vp); 4084 vp->v_iflag &= ~VI_DOINGINACT; 4085 return (error); 4086 } 4087 4088 int 4089 vinactive(struct vnode *vp) 4090 { 4091 4092 ASSERT_VOP_ELOCKED(vp, "vinactive"); 4093 ASSERT_VI_LOCKED(vp, "vinactive"); 4094 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 4095 4096 if ((vp->v_iflag & VI_OWEINACT) == 0) 4097 return (0); 4098 if (vp->v_iflag & VI_DOINGINACT) 4099 return (0); 4100 if (vp->v_usecount > 0) { 4101 vp->v_iflag &= ~VI_OWEINACT; 4102 return (0); 4103 } 4104 return (vinactivef(vp)); 4105 } 4106 4107 /* 4108 * Remove any vnodes in the vnode table belonging to mount point mp. 4109 * 4110 * If FORCECLOSE is not specified, there should not be any active ones, 4111 * return error if any are found (nb: this is a user error, not a 4112 * system error). If FORCECLOSE is specified, detach any active vnodes 4113 * that are found. 4114 * 4115 * If WRITECLOSE is set, only flush out regular file vnodes open for 4116 * writing. 4117 * 4118 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 4119 * 4120 * `rootrefs' specifies the base reference count for the root vnode 4121 * of this filesystem. The root vnode is considered busy if its 4122 * v_usecount exceeds this value. On a successful return, vflush(, td) 4123 * will call vrele() on the root vnode exactly rootrefs times. 4124 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 4125 * be zero. 4126 */ 4127 #ifdef DIAGNOSTIC 4128 static int busyprt = 0; /* print out busy vnodes */ 4129 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 4130 #endif 4131 4132 int 4133 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 4134 { 4135 struct vnode *vp, *mvp, *rootvp = NULL; 4136 struct vattr vattr; 4137 int busy = 0, error; 4138 4139 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 4140 rootrefs, flags); 4141 if (rootrefs > 0) { 4142 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 4143 ("vflush: bad args")); 4144 /* 4145 * Get the filesystem root vnode. We can vput() it 4146 * immediately, since with rootrefs > 0, it won't go away. 4147 */ 4148 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 4149 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 4150 __func__, error); 4151 return (error); 4152 } 4153 vput(rootvp); 4154 } 4155 loop: 4156 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 4157 vholdl(vp); 4158 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 4159 if (error) { 4160 vdrop(vp); 4161 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 4162 goto loop; 4163 } 4164 /* 4165 * Skip over a vnodes marked VV_SYSTEM. 4166 */ 4167 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 4168 VOP_UNLOCK(vp); 4169 vdrop(vp); 4170 continue; 4171 } 4172 /* 4173 * If WRITECLOSE is set, flush out unlinked but still open 4174 * files (even if open only for reading) and regular file 4175 * vnodes open for writing. 4176 */ 4177 if (flags & WRITECLOSE) { 4178 vnode_pager_clean_async(vp); 4179 do { 4180 error = VOP_FSYNC(vp, MNT_WAIT, td); 4181 } while (error == ERELOOKUP); 4182 if (error != 0) { 4183 VOP_UNLOCK(vp); 4184 vdrop(vp); 4185 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 4186 return (error); 4187 } 4188 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 4189 VI_LOCK(vp); 4190 4191 if ((vp->v_type == VNON || 4192 (error == 0 && vattr.va_nlink > 0)) && 4193 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 4194 VOP_UNLOCK(vp); 4195 vdropl(vp); 4196 continue; 4197 } 4198 } else 4199 VI_LOCK(vp); 4200 /* 4201 * With v_usecount == 0, all we need to do is clear out the 4202 * vnode data structures and we are done. 4203 * 4204 * If FORCECLOSE is set, forcibly close the vnode. 4205 */ 4206 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 4207 vgonel(vp); 4208 } else { 4209 busy++; 4210 #ifdef DIAGNOSTIC 4211 if (busyprt) 4212 vn_printf(vp, "vflush: busy vnode "); 4213 #endif 4214 } 4215 VOP_UNLOCK(vp); 4216 vdropl(vp); 4217 } 4218 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 4219 /* 4220 * If just the root vnode is busy, and if its refcount 4221 * is equal to `rootrefs', then go ahead and kill it. 4222 */ 4223 VI_LOCK(rootvp); 4224 KASSERT(busy > 0, ("vflush: not busy")); 4225 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 4226 ("vflush: usecount %d < rootrefs %d", 4227 rootvp->v_usecount, rootrefs)); 4228 if (busy == 1 && rootvp->v_usecount == rootrefs) { 4229 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 4230 vgone(rootvp); 4231 VOP_UNLOCK(rootvp); 4232 busy = 0; 4233 } else 4234 VI_UNLOCK(rootvp); 4235 } 4236 if (busy) { 4237 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 4238 busy); 4239 return (EBUSY); 4240 } 4241 for (; rootrefs > 0; rootrefs--) 4242 vrele(rootvp); 4243 return (0); 4244 } 4245 4246 /* 4247 * Recycle an unused vnode. 4248 */ 4249 int 4250 vrecycle(struct vnode *vp) 4251 { 4252 int recycled; 4253 4254 VI_LOCK(vp); 4255 recycled = vrecyclel(vp); 4256 VI_UNLOCK(vp); 4257 return (recycled); 4258 } 4259 4260 /* 4261 * vrecycle, with the vp interlock held. 4262 */ 4263 int 4264 vrecyclel(struct vnode *vp) 4265 { 4266 int recycled; 4267 4268 ASSERT_VOP_ELOCKED(vp, __func__); 4269 ASSERT_VI_LOCKED(vp, __func__); 4270 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 4271 recycled = 0; 4272 if (vp->v_usecount == 0) { 4273 recycled = 1; 4274 vgonel(vp); 4275 } 4276 return (recycled); 4277 } 4278 4279 /* 4280 * Eliminate all activity associated with a vnode 4281 * in preparation for reuse. 4282 */ 4283 void 4284 vgone(struct vnode *vp) 4285 { 4286 VI_LOCK(vp); 4287 vgonel(vp); 4288 VI_UNLOCK(vp); 4289 } 4290 4291 /* 4292 * Notify upper mounts about reclaimed or unlinked vnode. 4293 */ 4294 void 4295 vfs_notify_upper(struct vnode *vp, enum vfs_notify_upper_type event) 4296 { 4297 struct mount *mp; 4298 struct mount_upper_node *ump; 4299 4300 mp = atomic_load_ptr(&vp->v_mount); 4301 if (mp == NULL) 4302 return; 4303 if (TAILQ_EMPTY(&mp->mnt_notify)) 4304 return; 4305 4306 MNT_ILOCK(mp); 4307 mp->mnt_upper_pending++; 4308 KASSERT(mp->mnt_upper_pending > 0, 4309 ("%s: mnt_upper_pending %d", __func__, mp->mnt_upper_pending)); 4310 TAILQ_FOREACH(ump, &mp->mnt_notify, mnt_upper_link) { 4311 MNT_IUNLOCK(mp); 4312 switch (event) { 4313 case VFS_NOTIFY_UPPER_RECLAIM: 4314 VFS_RECLAIM_LOWERVP(ump->mp, vp); 4315 break; 4316 case VFS_NOTIFY_UPPER_UNLINK: 4317 VFS_UNLINK_LOWERVP(ump->mp, vp); 4318 break; 4319 } 4320 MNT_ILOCK(mp); 4321 } 4322 mp->mnt_upper_pending--; 4323 if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 && 4324 mp->mnt_upper_pending == 0) { 4325 mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER; 4326 wakeup(&mp->mnt_uppers); 4327 } 4328 MNT_IUNLOCK(mp); 4329 } 4330 4331 /* 4332 * vgone, with the vp interlock held. 4333 */ 4334 static void 4335 vgonel(struct vnode *vp) 4336 { 4337 struct thread *td; 4338 struct mount *mp; 4339 vm_object_t object; 4340 bool active, doinginact, oweinact; 4341 4342 ASSERT_VOP_ELOCKED(vp, "vgonel"); 4343 ASSERT_VI_LOCKED(vp, "vgonel"); 4344 VNASSERT(vp->v_holdcnt, vp, 4345 ("vgonel: vp %p has no reference.", vp)); 4346 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 4347 td = curthread; 4348 4349 /* 4350 * Don't vgonel if we're already doomed. 4351 */ 4352 if (VN_IS_DOOMED(vp)) { 4353 VNPASS(vn_get_state(vp) == VSTATE_DESTROYING || \ 4354 vn_get_state(vp) == VSTATE_DEAD, vp); 4355 return; 4356 } 4357 /* 4358 * Paired with freevnode. 4359 */ 4360 vn_seqc_write_begin_locked(vp); 4361 vunlazy_gone(vp); 4362 vn_irflag_set_locked(vp, VIRF_DOOMED); 4363 vn_set_state(vp, VSTATE_DESTROYING); 4364 4365 /* 4366 * Check to see if the vnode is in use. If so, we have to 4367 * call VOP_CLOSE() and VOP_INACTIVE(). 4368 * 4369 * It could be that VOP_INACTIVE() requested reclamation, in 4370 * which case we should avoid recursion, so check 4371 * VI_DOINGINACT. This is not precise but good enough. 4372 */ 4373 active = vp->v_usecount > 0; 4374 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 4375 doinginact = (vp->v_iflag & VI_DOINGINACT) != 0; 4376 4377 /* 4378 * If we need to do inactive VI_OWEINACT will be set. 4379 */ 4380 if (vp->v_iflag & VI_DEFINACT) { 4381 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 4382 vp->v_iflag &= ~VI_DEFINACT; 4383 vdropl(vp); 4384 } else { 4385 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 4386 VI_UNLOCK(vp); 4387 } 4388 cache_purge_vgone(vp); 4389 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 4390 4391 /* 4392 * If purging an active vnode, it must be closed and 4393 * deactivated before being reclaimed. 4394 */ 4395 if (active) 4396 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 4397 if (!doinginact) { 4398 do { 4399 if (oweinact || active) { 4400 VI_LOCK(vp); 4401 vinactivef(vp); 4402 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 4403 VI_UNLOCK(vp); 4404 } 4405 } while (oweinact); 4406 } 4407 if (vp->v_type == VSOCK) 4408 vfs_unp_reclaim(vp); 4409 4410 /* 4411 * Clean out any buffers associated with the vnode. 4412 * If the flush fails, just toss the buffers. 4413 */ 4414 mp = NULL; 4415 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 4416 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 4417 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 4418 while (vinvalbuf(vp, 0, 0, 0) != 0) 4419 ; 4420 } 4421 4422 BO_LOCK(&vp->v_bufobj); 4423 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 4424 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 4425 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 4426 vp->v_bufobj.bo_clean.bv_cnt == 0, 4427 ("vp %p bufobj not invalidated", vp)); 4428 4429 /* 4430 * For VMIO bufobj, BO_DEAD is set later, or in 4431 * vm_object_terminate() after the object's page queue is 4432 * flushed. 4433 */ 4434 object = vp->v_bufobj.bo_object; 4435 if (object == NULL) 4436 vp->v_bufobj.bo_flag |= BO_DEAD; 4437 BO_UNLOCK(&vp->v_bufobj); 4438 4439 /* 4440 * Handle the VM part. Tmpfs handles v_object on its own (the 4441 * OBJT_VNODE check). Nullfs or other bypassing filesystems 4442 * should not touch the object borrowed from the lower vnode 4443 * (the handle check). 4444 */ 4445 if (object != NULL && object->type == OBJT_VNODE && 4446 object->handle == vp) 4447 vnode_destroy_vobject(vp); 4448 4449 /* 4450 * Reclaim the vnode. 4451 */ 4452 if (VOP_RECLAIM(vp)) 4453 panic("vgone: cannot reclaim"); 4454 if (mp != NULL) 4455 vn_finished_secondary_write(mp); 4456 VNASSERT(vp->v_object == NULL, vp, 4457 ("vop_reclaim left v_object vp=%p", vp)); 4458 /* 4459 * Clear the advisory locks and wake up waiting threads. 4460 */ 4461 if (vp->v_lockf != NULL) { 4462 (void)VOP_ADVLOCKPURGE(vp); 4463 vp->v_lockf = NULL; 4464 } 4465 /* 4466 * Delete from old mount point vnode list. 4467 */ 4468 if (vp->v_mount == NULL) { 4469 VI_LOCK(vp); 4470 } else { 4471 delmntque(vp); 4472 ASSERT_VI_LOCKED(vp, "vgonel 2"); 4473 } 4474 /* 4475 * Done with purge, reset to the standard lock and invalidate 4476 * the vnode. 4477 */ 4478 vp->v_vnlock = &vp->v_lock; 4479 vp->v_op = &dead_vnodeops; 4480 vp->v_type = VBAD; 4481 vn_set_state(vp, VSTATE_DEAD); 4482 } 4483 4484 /* 4485 * Print out a description of a vnode. 4486 */ 4487 static const char *const vtypename[] = { 4488 [VNON] = "VNON", 4489 [VREG] = "VREG", 4490 [VDIR] = "VDIR", 4491 [VBLK] = "VBLK", 4492 [VCHR] = "VCHR", 4493 [VLNK] = "VLNK", 4494 [VSOCK] = "VSOCK", 4495 [VFIFO] = "VFIFO", 4496 [VBAD] = "VBAD", 4497 [VMARKER] = "VMARKER", 4498 }; 4499 _Static_assert(nitems(vtypename) == VLASTTYPE + 1, 4500 "vnode type name not added to vtypename"); 4501 4502 static const char *const vstatename[] = { 4503 [VSTATE_UNINITIALIZED] = "VSTATE_UNINITIALIZED", 4504 [VSTATE_CONSTRUCTED] = "VSTATE_CONSTRUCTED", 4505 [VSTATE_DESTROYING] = "VSTATE_DESTROYING", 4506 [VSTATE_DEAD] = "VSTATE_DEAD", 4507 }; 4508 _Static_assert(nitems(vstatename) == VLASTSTATE + 1, 4509 "vnode state name not added to vstatename"); 4510 4511 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0, 4512 "new hold count flag not added to vn_printf"); 4513 4514 void 4515 vn_printf(struct vnode *vp, const char *fmt, ...) 4516 { 4517 va_list ap; 4518 char buf[256], buf2[16]; 4519 u_long flags; 4520 u_int holdcnt; 4521 short irflag; 4522 4523 va_start(ap, fmt); 4524 vprintf(fmt, ap); 4525 va_end(ap); 4526 printf("%p: ", (void *)vp); 4527 printf("type %s state %s op %p\n", vtypename[vp->v_type], 4528 vstatename[vp->v_state], vp->v_op); 4529 holdcnt = atomic_load_int(&vp->v_holdcnt); 4530 printf(" usecount %d, writecount %d, refcount %d seqc users %d", 4531 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS, 4532 vp->v_seqc_users); 4533 switch (vp->v_type) { 4534 case VDIR: 4535 printf(" mountedhere %p\n", vp->v_mountedhere); 4536 break; 4537 case VCHR: 4538 printf(" rdev %p\n", vp->v_rdev); 4539 break; 4540 case VSOCK: 4541 printf(" socket %p\n", vp->v_unpcb); 4542 break; 4543 case VFIFO: 4544 printf(" fifoinfo %p\n", vp->v_fifoinfo); 4545 break; 4546 default: 4547 printf("\n"); 4548 break; 4549 } 4550 buf[0] = '\0'; 4551 buf[1] = '\0'; 4552 if (holdcnt & VHOLD_NO_SMR) 4553 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf)); 4554 printf(" hold count flags (%s)\n", buf + 1); 4555 4556 buf[0] = '\0'; 4557 buf[1] = '\0'; 4558 irflag = vn_irflag_read(vp); 4559 if (irflag & VIRF_DOOMED) 4560 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 4561 if (irflag & VIRF_PGREAD) 4562 strlcat(buf, "|VIRF_PGREAD", sizeof(buf)); 4563 if (irflag & VIRF_MOUNTPOINT) 4564 strlcat(buf, "|VIRF_MOUNTPOINT", sizeof(buf)); 4565 if (irflag & VIRF_TEXT_REF) 4566 strlcat(buf, "|VIRF_TEXT_REF", sizeof(buf)); 4567 flags = irflag & ~(VIRF_DOOMED | VIRF_PGREAD | VIRF_MOUNTPOINT | VIRF_TEXT_REF); 4568 if (flags != 0) { 4569 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 4570 strlcat(buf, buf2, sizeof(buf)); 4571 } 4572 if (vp->v_vflag & VV_ROOT) 4573 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4574 if (vp->v_vflag & VV_ISTTY) 4575 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4576 if (vp->v_vflag & VV_NOSYNC) 4577 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4578 if (vp->v_vflag & VV_ETERNALDEV) 4579 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4580 if (vp->v_vflag & VV_CACHEDLABEL) 4581 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4582 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4583 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4584 if (vp->v_vflag & VV_COPYONWRITE) 4585 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4586 if (vp->v_vflag & VV_SYSTEM) 4587 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4588 if (vp->v_vflag & VV_PROCDEP) 4589 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4590 if (vp->v_vflag & VV_DELETED) 4591 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4592 if (vp->v_vflag & VV_MD) 4593 strlcat(buf, "|VV_MD", sizeof(buf)); 4594 if (vp->v_vflag & VV_FORCEINSMQ) 4595 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4596 if (vp->v_vflag & VV_READLINK) 4597 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4598 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4599 VV_CACHEDLABEL | VV_VMSIZEVNLOCK | VV_COPYONWRITE | VV_SYSTEM | 4600 VV_PROCDEP | VV_DELETED | VV_MD | VV_FORCEINSMQ | VV_READLINK); 4601 if (flags != 0) { 4602 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4603 strlcat(buf, buf2, sizeof(buf)); 4604 } 4605 if (vp->v_iflag & VI_MOUNT) 4606 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4607 if (vp->v_iflag & VI_DOINGINACT) 4608 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4609 if (vp->v_iflag & VI_OWEINACT) 4610 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4611 if (vp->v_iflag & VI_DEFINACT) 4612 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4613 if (vp->v_iflag & VI_FOPENING) 4614 strlcat(buf, "|VI_FOPENING", sizeof(buf)); 4615 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOINGINACT | 4616 VI_OWEINACT | VI_DEFINACT | VI_FOPENING); 4617 if (flags != 0) { 4618 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4619 strlcat(buf, buf2, sizeof(buf)); 4620 } 4621 if (vp->v_mflag & VMP_LAZYLIST) 4622 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4623 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4624 if (flags != 0) { 4625 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4626 strlcat(buf, buf2, sizeof(buf)); 4627 } 4628 printf(" flags (%s)", buf + 1); 4629 if (mtx_owned(VI_MTX(vp))) 4630 printf(" VI_LOCKed"); 4631 printf("\n"); 4632 if (vp->v_object != NULL) 4633 printf(" v_object %p ref %d pages %d " 4634 "cleanbuf %d dirtybuf %d\n", 4635 vp->v_object, vp->v_object->ref_count, 4636 vp->v_object->resident_page_count, 4637 vp->v_bufobj.bo_clean.bv_cnt, 4638 vp->v_bufobj.bo_dirty.bv_cnt); 4639 printf(" "); 4640 lockmgr_printinfo(vp->v_vnlock); 4641 if (vp->v_data != NULL) 4642 VOP_PRINT(vp); 4643 } 4644 4645 #ifdef DDB 4646 /* 4647 * List all of the locked vnodes in the system. 4648 * Called when debugging the kernel. 4649 */ 4650 DB_SHOW_COMMAND_FLAGS(lockedvnods, lockedvnodes, DB_CMD_MEMSAFE) 4651 { 4652 struct mount *mp; 4653 struct vnode *vp; 4654 4655 /* 4656 * Note: because this is DDB, we can't obey the locking semantics 4657 * for these structures, which means we could catch an inconsistent 4658 * state and dereference a nasty pointer. Not much to be done 4659 * about that. 4660 */ 4661 db_printf("Locked vnodes\n"); 4662 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4663 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4664 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4665 vn_printf(vp, "vnode "); 4666 } 4667 } 4668 } 4669 4670 /* 4671 * Show details about the given vnode. 4672 */ 4673 DB_SHOW_COMMAND(vnode, db_show_vnode) 4674 { 4675 struct vnode *vp; 4676 4677 if (!have_addr) 4678 return; 4679 vp = (struct vnode *)addr; 4680 vn_printf(vp, "vnode "); 4681 } 4682 4683 /* 4684 * Show details about the given mount point. 4685 */ 4686 DB_SHOW_COMMAND(mount, db_show_mount) 4687 { 4688 struct mount *mp; 4689 struct vfsopt *opt; 4690 struct statfs *sp; 4691 struct vnode *vp; 4692 char buf[512]; 4693 uint64_t mflags; 4694 u_int flags; 4695 4696 if (!have_addr) { 4697 /* No address given, print short info about all mount points. */ 4698 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4699 db_printf("%p %s on %s (%s)\n", mp, 4700 mp->mnt_stat.f_mntfromname, 4701 mp->mnt_stat.f_mntonname, 4702 mp->mnt_stat.f_fstypename); 4703 if (db_pager_quit) 4704 break; 4705 } 4706 db_printf("\nMore info: show mount <addr>\n"); 4707 return; 4708 } 4709 4710 mp = (struct mount *)addr; 4711 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4712 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4713 4714 buf[0] = '\0'; 4715 mflags = mp->mnt_flag; 4716 #define MNT_FLAG(flag) do { \ 4717 if (mflags & (flag)) { \ 4718 if (buf[0] != '\0') \ 4719 strlcat(buf, ", ", sizeof(buf)); \ 4720 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4721 mflags &= ~(flag); \ 4722 } \ 4723 } while (0) 4724 MNT_FLAG(MNT_RDONLY); 4725 MNT_FLAG(MNT_SYNCHRONOUS); 4726 MNT_FLAG(MNT_NOEXEC); 4727 MNT_FLAG(MNT_NOSUID); 4728 MNT_FLAG(MNT_NFS4ACLS); 4729 MNT_FLAG(MNT_UNION); 4730 MNT_FLAG(MNT_ASYNC); 4731 MNT_FLAG(MNT_SUIDDIR); 4732 MNT_FLAG(MNT_SOFTDEP); 4733 MNT_FLAG(MNT_NOSYMFOLLOW); 4734 MNT_FLAG(MNT_GJOURNAL); 4735 MNT_FLAG(MNT_MULTILABEL); 4736 MNT_FLAG(MNT_ACLS); 4737 MNT_FLAG(MNT_NOATIME); 4738 MNT_FLAG(MNT_NOCLUSTERR); 4739 MNT_FLAG(MNT_NOCLUSTERW); 4740 MNT_FLAG(MNT_SUJ); 4741 MNT_FLAG(MNT_EXRDONLY); 4742 MNT_FLAG(MNT_EXPORTED); 4743 MNT_FLAG(MNT_DEFEXPORTED); 4744 MNT_FLAG(MNT_EXPORTANON); 4745 MNT_FLAG(MNT_EXKERB); 4746 MNT_FLAG(MNT_EXPUBLIC); 4747 MNT_FLAG(MNT_LOCAL); 4748 MNT_FLAG(MNT_QUOTA); 4749 MNT_FLAG(MNT_ROOTFS); 4750 MNT_FLAG(MNT_USER); 4751 MNT_FLAG(MNT_IGNORE); 4752 MNT_FLAG(MNT_UPDATE); 4753 MNT_FLAG(MNT_DELEXPORT); 4754 MNT_FLAG(MNT_RELOAD); 4755 MNT_FLAG(MNT_FORCE); 4756 MNT_FLAG(MNT_SNAPSHOT); 4757 MNT_FLAG(MNT_BYFSID); 4758 #undef MNT_FLAG 4759 if (mflags != 0) { 4760 if (buf[0] != '\0') 4761 strlcat(buf, ", ", sizeof(buf)); 4762 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4763 "0x%016jx", mflags); 4764 } 4765 db_printf(" mnt_flag = %s\n", buf); 4766 4767 buf[0] = '\0'; 4768 flags = mp->mnt_kern_flag; 4769 #define MNT_KERN_FLAG(flag) do { \ 4770 if (flags & (flag)) { \ 4771 if (buf[0] != '\0') \ 4772 strlcat(buf, ", ", sizeof(buf)); \ 4773 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4774 flags &= ~(flag); \ 4775 } \ 4776 } while (0) 4777 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4778 MNT_KERN_FLAG(MNTK_ASYNC); 4779 MNT_KERN_FLAG(MNTK_SOFTDEP); 4780 MNT_KERN_FLAG(MNTK_NOMSYNC); 4781 MNT_KERN_FLAG(MNTK_DRAINING); 4782 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4783 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4784 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4785 MNT_KERN_FLAG(MNTK_NO_IOPF); 4786 MNT_KERN_FLAG(MNTK_RECURSE); 4787 MNT_KERN_FLAG(MNTK_UPPER_WAITER); 4788 MNT_KERN_FLAG(MNTK_UNLOCKED_INSMNTQUE); 4789 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4790 MNT_KERN_FLAG(MNTK_VMSETSIZE_BUG); 4791 MNT_KERN_FLAG(MNTK_FPLOOKUP); 4792 MNT_KERN_FLAG(MNTK_TASKQUEUE_WAITER); 4793 MNT_KERN_FLAG(MNTK_NOASYNC); 4794 MNT_KERN_FLAG(MNTK_UNMOUNT); 4795 MNT_KERN_FLAG(MNTK_MWAIT); 4796 MNT_KERN_FLAG(MNTK_SUSPEND); 4797 MNT_KERN_FLAG(MNTK_SUSPEND2); 4798 MNT_KERN_FLAG(MNTK_SUSPENDED); 4799 MNT_KERN_FLAG(MNTK_NULL_NOCACHE); 4800 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4801 #undef MNT_KERN_FLAG 4802 if (flags != 0) { 4803 if (buf[0] != '\0') 4804 strlcat(buf, ", ", sizeof(buf)); 4805 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4806 "0x%08x", flags); 4807 } 4808 db_printf(" mnt_kern_flag = %s\n", buf); 4809 4810 db_printf(" mnt_opt = "); 4811 opt = TAILQ_FIRST(mp->mnt_opt); 4812 if (opt != NULL) { 4813 db_printf("%s", opt->name); 4814 opt = TAILQ_NEXT(opt, link); 4815 while (opt != NULL) { 4816 db_printf(", %s", opt->name); 4817 opt = TAILQ_NEXT(opt, link); 4818 } 4819 } 4820 db_printf("\n"); 4821 4822 sp = &mp->mnt_stat; 4823 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4824 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4825 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4826 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4827 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4828 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4829 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4830 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4831 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4832 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4833 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4834 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4835 4836 db_printf(" mnt_cred = { uid=%u ruid=%u", 4837 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4838 if (jailed(mp->mnt_cred)) 4839 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4840 db_printf(" }\n"); 4841 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4842 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4843 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4844 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4845 db_printf(" mnt_lazyvnodelistsize = %d\n", 4846 mp->mnt_lazyvnodelistsize); 4847 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4848 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4849 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4850 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4851 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4852 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4853 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4854 db_printf(" mnt_secondary_accwrites = %d\n", 4855 mp->mnt_secondary_accwrites); 4856 db_printf(" mnt_gjprovider = %s\n", 4857 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4858 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4859 4860 db_printf("\n\nList of active vnodes\n"); 4861 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4862 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4863 vn_printf(vp, "vnode "); 4864 if (db_pager_quit) 4865 break; 4866 } 4867 } 4868 db_printf("\n\nList of inactive vnodes\n"); 4869 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4870 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4871 vn_printf(vp, "vnode "); 4872 if (db_pager_quit) 4873 break; 4874 } 4875 } 4876 } 4877 #endif /* DDB */ 4878 4879 /* 4880 * Fill in a struct xvfsconf based on a struct vfsconf. 4881 */ 4882 static int 4883 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4884 { 4885 struct xvfsconf xvfsp; 4886 4887 bzero(&xvfsp, sizeof(xvfsp)); 4888 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4889 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4890 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4891 xvfsp.vfc_flags = vfsp->vfc_flags; 4892 /* 4893 * These are unused in userland, we keep them 4894 * to not break binary compatibility. 4895 */ 4896 xvfsp.vfc_vfsops = NULL; 4897 xvfsp.vfc_next = NULL; 4898 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4899 } 4900 4901 #ifdef COMPAT_FREEBSD32 4902 struct xvfsconf32 { 4903 uint32_t vfc_vfsops; 4904 char vfc_name[MFSNAMELEN]; 4905 int32_t vfc_typenum; 4906 int32_t vfc_refcount; 4907 int32_t vfc_flags; 4908 uint32_t vfc_next; 4909 }; 4910 4911 static int 4912 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4913 { 4914 struct xvfsconf32 xvfsp; 4915 4916 bzero(&xvfsp, sizeof(xvfsp)); 4917 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4918 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4919 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4920 xvfsp.vfc_flags = vfsp->vfc_flags; 4921 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4922 } 4923 #endif 4924 4925 /* 4926 * Top level filesystem related information gathering. 4927 */ 4928 static int 4929 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4930 { 4931 struct vfsconf *vfsp; 4932 int error; 4933 4934 error = 0; 4935 vfsconf_slock(); 4936 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4937 #ifdef COMPAT_FREEBSD32 4938 if (req->flags & SCTL_MASK32) 4939 error = vfsconf2x32(req, vfsp); 4940 else 4941 #endif 4942 error = vfsconf2x(req, vfsp); 4943 if (error) 4944 break; 4945 } 4946 vfsconf_sunlock(); 4947 return (error); 4948 } 4949 4950 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4951 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4952 "S,xvfsconf", "List of all configured filesystems"); 4953 4954 #ifndef BURN_BRIDGES 4955 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4956 4957 static int 4958 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4959 { 4960 int *name = (int *)arg1 - 1; /* XXX */ 4961 u_int namelen = arg2 + 1; /* XXX */ 4962 struct vfsconf *vfsp; 4963 4964 log(LOG_WARNING, "userland calling deprecated sysctl, " 4965 "please rebuild world\n"); 4966 4967 #if 1 || defined(COMPAT_PRELITE2) 4968 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4969 if (namelen == 1) 4970 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4971 #endif 4972 4973 switch (name[1]) { 4974 case VFS_MAXTYPENUM: 4975 if (namelen != 2) 4976 return (ENOTDIR); 4977 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4978 case VFS_CONF: 4979 if (namelen != 3) 4980 return (ENOTDIR); /* overloaded */ 4981 vfsconf_slock(); 4982 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4983 if (vfsp->vfc_typenum == name[2]) 4984 break; 4985 } 4986 vfsconf_sunlock(); 4987 if (vfsp == NULL) 4988 return (EOPNOTSUPP); 4989 #ifdef COMPAT_FREEBSD32 4990 if (req->flags & SCTL_MASK32) 4991 return (vfsconf2x32(req, vfsp)); 4992 else 4993 #endif 4994 return (vfsconf2x(req, vfsp)); 4995 } 4996 return (EOPNOTSUPP); 4997 } 4998 4999 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 5000 CTLFLAG_MPSAFE, vfs_sysctl, 5001 "Generic filesystem"); 5002 5003 #if 1 || defined(COMPAT_PRELITE2) 5004 5005 static int 5006 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 5007 { 5008 int error; 5009 struct vfsconf *vfsp; 5010 struct ovfsconf ovfs; 5011 5012 vfsconf_slock(); 5013 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 5014 bzero(&ovfs, sizeof(ovfs)); 5015 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 5016 strcpy(ovfs.vfc_name, vfsp->vfc_name); 5017 ovfs.vfc_index = vfsp->vfc_typenum; 5018 ovfs.vfc_refcount = vfsp->vfc_refcount; 5019 ovfs.vfc_flags = vfsp->vfc_flags; 5020 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 5021 if (error != 0) { 5022 vfsconf_sunlock(); 5023 return (error); 5024 } 5025 } 5026 vfsconf_sunlock(); 5027 return (0); 5028 } 5029 5030 #endif /* 1 || COMPAT_PRELITE2 */ 5031 #endif /* !BURN_BRIDGES */ 5032 5033 static void 5034 unmount_or_warn(struct mount *mp) 5035 { 5036 int error; 5037 5038 error = dounmount(mp, MNT_FORCE, curthread); 5039 if (error != 0) { 5040 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 5041 if (error == EBUSY) 5042 printf("BUSY)\n"); 5043 else 5044 printf("%d)\n", error); 5045 } 5046 } 5047 5048 /* 5049 * Unmount all filesystems. The list is traversed in reverse order 5050 * of mounting to avoid dependencies. 5051 */ 5052 void 5053 vfs_unmountall(void) 5054 { 5055 struct mount *mp, *tmp; 5056 5057 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 5058 5059 /* 5060 * Since this only runs when rebooting, it is not interlocked. 5061 */ 5062 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 5063 vfs_ref(mp); 5064 5065 /* 5066 * Forcibly unmounting "/dev" before "/" would prevent clean 5067 * unmount of the latter. 5068 */ 5069 if (mp == rootdevmp) 5070 continue; 5071 5072 unmount_or_warn(mp); 5073 } 5074 5075 if (rootdevmp != NULL) 5076 unmount_or_warn(rootdevmp); 5077 } 5078 5079 static void 5080 vfs_deferred_inactive(struct vnode *vp, int lkflags) 5081 { 5082 5083 ASSERT_VI_LOCKED(vp, __func__); 5084 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp); 5085 if ((vp->v_iflag & VI_OWEINACT) == 0) { 5086 vdropl(vp); 5087 return; 5088 } 5089 if (vn_lock(vp, lkflags) == 0) { 5090 VI_LOCK(vp); 5091 vinactive(vp); 5092 VOP_UNLOCK(vp); 5093 vdropl(vp); 5094 return; 5095 } 5096 vdefer_inactive_unlocked(vp); 5097 } 5098 5099 static int 5100 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 5101 { 5102 5103 return (vp->v_iflag & VI_DEFINACT); 5104 } 5105 5106 static void __noinline 5107 vfs_periodic_inactive(struct mount *mp, int flags) 5108 { 5109 struct vnode *vp, *mvp; 5110 int lkflags; 5111 5112 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 5113 if (flags != MNT_WAIT) 5114 lkflags |= LK_NOWAIT; 5115 5116 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 5117 if ((vp->v_iflag & VI_DEFINACT) == 0) { 5118 VI_UNLOCK(vp); 5119 continue; 5120 } 5121 vp->v_iflag &= ~VI_DEFINACT; 5122 vfs_deferred_inactive(vp, lkflags); 5123 } 5124 } 5125 5126 static inline bool 5127 vfs_want_msync(struct vnode *vp) 5128 { 5129 struct vm_object *obj; 5130 5131 /* 5132 * This test may be performed without any locks held. 5133 * We rely on vm_object's type stability. 5134 */ 5135 if (vp->v_vflag & VV_NOSYNC) 5136 return (false); 5137 obj = vp->v_object; 5138 return (obj != NULL && vm_object_mightbedirty(obj)); 5139 } 5140 5141 static int 5142 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 5143 { 5144 5145 if (vp->v_vflag & VV_NOSYNC) 5146 return (false); 5147 if (vp->v_iflag & VI_DEFINACT) 5148 return (true); 5149 return (vfs_want_msync(vp)); 5150 } 5151 5152 static void __noinline 5153 vfs_periodic_msync_inactive(struct mount *mp, int flags) 5154 { 5155 struct vnode *vp, *mvp; 5156 int lkflags; 5157 bool seen_defer; 5158 5159 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 5160 if (flags != MNT_WAIT) 5161 lkflags |= LK_NOWAIT; 5162 5163 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 5164 seen_defer = false; 5165 if (vp->v_iflag & VI_DEFINACT) { 5166 vp->v_iflag &= ~VI_DEFINACT; 5167 seen_defer = true; 5168 } 5169 if (!vfs_want_msync(vp)) { 5170 if (seen_defer) 5171 vfs_deferred_inactive(vp, lkflags); 5172 else 5173 VI_UNLOCK(vp); 5174 continue; 5175 } 5176 if (vget(vp, lkflags) == 0) { 5177 if ((vp->v_vflag & VV_NOSYNC) == 0) { 5178 if (flags == MNT_WAIT) 5179 vnode_pager_clean_sync(vp); 5180 else 5181 vnode_pager_clean_async(vp); 5182 } 5183 vput(vp); 5184 if (seen_defer) 5185 vdrop(vp); 5186 } else { 5187 if (seen_defer) 5188 vdefer_inactive_unlocked(vp); 5189 } 5190 } 5191 } 5192 5193 void 5194 vfs_periodic(struct mount *mp, int flags) 5195 { 5196 5197 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 5198 5199 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 5200 vfs_periodic_inactive(mp, flags); 5201 else 5202 vfs_periodic_msync_inactive(mp, flags); 5203 } 5204 5205 static void 5206 destroy_vpollinfo_free(struct vpollinfo *vi) 5207 { 5208 5209 knlist_destroy(&vi->vpi_selinfo.si_note); 5210 mtx_destroy(&vi->vpi_lock); 5211 free(vi, M_VNODEPOLL); 5212 } 5213 5214 static void 5215 destroy_vpollinfo(struct vpollinfo *vi) 5216 { 5217 5218 knlist_clear(&vi->vpi_selinfo.si_note, 1); 5219 seldrain(&vi->vpi_selinfo); 5220 destroy_vpollinfo_free(vi); 5221 } 5222 5223 /* 5224 * Initialize per-vnode helper structure to hold poll-related state. 5225 */ 5226 void 5227 v_addpollinfo(struct vnode *vp) 5228 { 5229 struct vpollinfo *vi; 5230 5231 if (vp->v_pollinfo != NULL) 5232 return; 5233 vi = malloc(sizeof(*vi), M_VNODEPOLL, M_WAITOK | M_ZERO); 5234 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 5235 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 5236 vfs_knlunlock, vfs_knl_assert_lock); 5237 VI_LOCK(vp); 5238 if (vp->v_pollinfo != NULL) { 5239 VI_UNLOCK(vp); 5240 destroy_vpollinfo_free(vi); 5241 return; 5242 } 5243 vp->v_pollinfo = vi; 5244 VI_UNLOCK(vp); 5245 } 5246 5247 /* 5248 * Record a process's interest in events which might happen to 5249 * a vnode. Because poll uses the historic select-style interface 5250 * internally, this routine serves as both the ``check for any 5251 * pending events'' and the ``record my interest in future events'' 5252 * functions. (These are done together, while the lock is held, 5253 * to avoid race conditions.) 5254 */ 5255 int 5256 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 5257 { 5258 5259 v_addpollinfo(vp); 5260 mtx_lock(&vp->v_pollinfo->vpi_lock); 5261 if (vp->v_pollinfo->vpi_revents & events) { 5262 /* 5263 * This leaves events we are not interested 5264 * in available for the other process which 5265 * which presumably had requested them 5266 * (otherwise they would never have been 5267 * recorded). 5268 */ 5269 events &= vp->v_pollinfo->vpi_revents; 5270 vp->v_pollinfo->vpi_revents &= ~events; 5271 5272 mtx_unlock(&vp->v_pollinfo->vpi_lock); 5273 return (events); 5274 } 5275 vp->v_pollinfo->vpi_events |= events; 5276 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 5277 mtx_unlock(&vp->v_pollinfo->vpi_lock); 5278 return (0); 5279 } 5280 5281 /* 5282 * Routine to create and manage a filesystem syncer vnode. 5283 */ 5284 #define sync_close ((int (*)(struct vop_close_args *))nullop) 5285 static int sync_fsync(struct vop_fsync_args *); 5286 static int sync_inactive(struct vop_inactive_args *); 5287 static int sync_reclaim(struct vop_reclaim_args *); 5288 5289 static struct vop_vector sync_vnodeops = { 5290 .vop_bypass = VOP_EOPNOTSUPP, 5291 .vop_close = sync_close, 5292 .vop_fsync = sync_fsync, 5293 .vop_getwritemount = vop_stdgetwritemount, 5294 .vop_inactive = sync_inactive, 5295 .vop_need_inactive = vop_stdneed_inactive, 5296 .vop_reclaim = sync_reclaim, 5297 .vop_lock1 = vop_stdlock, 5298 .vop_unlock = vop_stdunlock, 5299 .vop_islocked = vop_stdislocked, 5300 .vop_fplookup_vexec = VOP_EAGAIN, 5301 .vop_fplookup_symlink = VOP_EAGAIN, 5302 }; 5303 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 5304 5305 /* 5306 * Create a new filesystem syncer vnode for the specified mount point. 5307 */ 5308 void 5309 vfs_allocate_syncvnode(struct mount *mp) 5310 { 5311 struct vnode *vp; 5312 struct bufobj *bo; 5313 static long start, incr, next; 5314 int error; 5315 5316 /* Allocate a new vnode */ 5317 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 5318 if (error != 0) 5319 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 5320 vp->v_type = VNON; 5321 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5322 vp->v_vflag |= VV_FORCEINSMQ; 5323 error = insmntque1(vp, mp); 5324 if (error != 0) 5325 panic("vfs_allocate_syncvnode: insmntque() failed"); 5326 vp->v_vflag &= ~VV_FORCEINSMQ; 5327 vn_set_state(vp, VSTATE_CONSTRUCTED); 5328 VOP_UNLOCK(vp); 5329 /* 5330 * Place the vnode onto the syncer worklist. We attempt to 5331 * scatter them about on the list so that they will go off 5332 * at evenly distributed times even if all the filesystems 5333 * are mounted at once. 5334 */ 5335 next += incr; 5336 if (next == 0 || next > syncer_maxdelay) { 5337 start /= 2; 5338 incr /= 2; 5339 if (start == 0) { 5340 start = syncer_maxdelay / 2; 5341 incr = syncer_maxdelay; 5342 } 5343 next = start; 5344 } 5345 bo = &vp->v_bufobj; 5346 BO_LOCK(bo); 5347 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 5348 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 5349 mtx_lock(&sync_mtx); 5350 sync_vnode_count++; 5351 if (mp->mnt_syncer == NULL) { 5352 mp->mnt_syncer = vp; 5353 vp = NULL; 5354 } 5355 mtx_unlock(&sync_mtx); 5356 BO_UNLOCK(bo); 5357 if (vp != NULL) { 5358 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5359 vgone(vp); 5360 vput(vp); 5361 } 5362 } 5363 5364 void 5365 vfs_deallocate_syncvnode(struct mount *mp) 5366 { 5367 struct vnode *vp; 5368 5369 mtx_lock(&sync_mtx); 5370 vp = mp->mnt_syncer; 5371 if (vp != NULL) 5372 mp->mnt_syncer = NULL; 5373 mtx_unlock(&sync_mtx); 5374 if (vp != NULL) 5375 vrele(vp); 5376 } 5377 5378 /* 5379 * Do a lazy sync of the filesystem. 5380 */ 5381 static int 5382 sync_fsync(struct vop_fsync_args *ap) 5383 { 5384 struct vnode *syncvp = ap->a_vp; 5385 struct mount *mp = syncvp->v_mount; 5386 int error, save; 5387 struct bufobj *bo; 5388 5389 /* 5390 * We only need to do something if this is a lazy evaluation. 5391 */ 5392 if (ap->a_waitfor != MNT_LAZY) 5393 return (0); 5394 5395 /* 5396 * Move ourselves to the back of the sync list. 5397 */ 5398 bo = &syncvp->v_bufobj; 5399 BO_LOCK(bo); 5400 vn_syncer_add_to_worklist(bo, syncdelay); 5401 BO_UNLOCK(bo); 5402 5403 /* 5404 * Walk the list of vnodes pushing all that are dirty and 5405 * not already on the sync list. 5406 */ 5407 if (vfs_busy(mp, MBF_NOWAIT) != 0) 5408 return (0); 5409 VOP_UNLOCK(syncvp); 5410 save = curthread_pflags_set(TDP_SYNCIO); 5411 /* 5412 * The filesystem at hand may be idle with free vnodes stored in the 5413 * batch. Return them instead of letting them stay there indefinitely. 5414 */ 5415 vfs_periodic(mp, MNT_NOWAIT); 5416 error = VFS_SYNC(mp, MNT_LAZY); 5417 curthread_pflags_restore(save); 5418 vn_lock(syncvp, LK_EXCLUSIVE | LK_RETRY); 5419 vfs_unbusy(mp); 5420 return (error); 5421 } 5422 5423 /* 5424 * The syncer vnode is no referenced. 5425 */ 5426 static int 5427 sync_inactive(struct vop_inactive_args *ap) 5428 { 5429 5430 vgone(ap->a_vp); 5431 return (0); 5432 } 5433 5434 /* 5435 * The syncer vnode is no longer needed and is being decommissioned. 5436 * 5437 * Modifications to the worklist must be protected by sync_mtx. 5438 */ 5439 static int 5440 sync_reclaim(struct vop_reclaim_args *ap) 5441 { 5442 struct vnode *vp = ap->a_vp; 5443 struct bufobj *bo; 5444 5445 bo = &vp->v_bufobj; 5446 BO_LOCK(bo); 5447 mtx_lock(&sync_mtx); 5448 if (vp->v_mount->mnt_syncer == vp) 5449 vp->v_mount->mnt_syncer = NULL; 5450 if (bo->bo_flag & BO_ONWORKLST) { 5451 LIST_REMOVE(bo, bo_synclist); 5452 syncer_worklist_len--; 5453 sync_vnode_count--; 5454 bo->bo_flag &= ~BO_ONWORKLST; 5455 } 5456 mtx_unlock(&sync_mtx); 5457 BO_UNLOCK(bo); 5458 5459 return (0); 5460 } 5461 5462 int 5463 vn_need_pageq_flush(struct vnode *vp) 5464 { 5465 struct vm_object *obj; 5466 5467 obj = vp->v_object; 5468 return (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5469 vm_object_mightbedirty(obj)); 5470 } 5471 5472 /* 5473 * Check if vnode represents a disk device 5474 */ 5475 bool 5476 vn_isdisk_error(struct vnode *vp, int *errp) 5477 { 5478 int error; 5479 5480 if (vp->v_type != VCHR) { 5481 error = ENOTBLK; 5482 goto out; 5483 } 5484 error = 0; 5485 dev_lock(); 5486 if (vp->v_rdev == NULL) 5487 error = ENXIO; 5488 else if (vp->v_rdev->si_devsw == NULL) 5489 error = ENXIO; 5490 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5491 error = ENOTBLK; 5492 dev_unlock(); 5493 out: 5494 *errp = error; 5495 return (error == 0); 5496 } 5497 5498 bool 5499 vn_isdisk(struct vnode *vp) 5500 { 5501 int error; 5502 5503 return (vn_isdisk_error(vp, &error)); 5504 } 5505 5506 /* 5507 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see 5508 * the comment above cache_fplookup for details. 5509 */ 5510 int 5511 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred) 5512 { 5513 int error; 5514 5515 VFS_SMR_ASSERT_ENTERED(); 5516 5517 /* Check the owner. */ 5518 if (cred->cr_uid == file_uid) { 5519 if (file_mode & S_IXUSR) 5520 return (0); 5521 goto out_error; 5522 } 5523 5524 /* Otherwise, check the groups (first match) */ 5525 if (groupmember(file_gid, cred)) { 5526 if (file_mode & S_IXGRP) 5527 return (0); 5528 goto out_error; 5529 } 5530 5531 /* Otherwise, check everyone else. */ 5532 if (file_mode & S_IXOTH) 5533 return (0); 5534 out_error: 5535 /* 5536 * Permission check failed, but it is possible denial will get overwritten 5537 * (e.g., when root is traversing through a 700 directory owned by someone 5538 * else). 5539 * 5540 * vaccess() calls priv_check_cred which in turn can descent into MAC 5541 * modules overriding this result. It's quite unclear what semantics 5542 * are allowed for them to operate, thus for safety we don't call them 5543 * from within the SMR section. This also means if any such modules 5544 * are present, we have to let the regular lookup decide. 5545 */ 5546 error = priv_check_cred_vfs_lookup_nomac(cred); 5547 switch (error) { 5548 case 0: 5549 return (0); 5550 case EAGAIN: 5551 /* 5552 * MAC modules present. 5553 */ 5554 return (EAGAIN); 5555 case EPERM: 5556 return (EACCES); 5557 default: 5558 return (error); 5559 } 5560 } 5561 5562 /* 5563 * Common filesystem object access control check routine. Accepts a 5564 * vnode's type, "mode", uid and gid, requested access mode, and credentials. 5565 * Returns 0 on success, or an errno on failure. 5566 */ 5567 int 5568 vaccess(__enum_uint8(vtype) type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5569 accmode_t accmode, struct ucred *cred) 5570 { 5571 accmode_t dac_granted; 5572 accmode_t priv_granted; 5573 5574 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5575 ("invalid bit in accmode")); 5576 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5577 ("VAPPEND without VWRITE")); 5578 5579 /* 5580 * Look for a normal, non-privileged way to access the file/directory 5581 * as requested. If it exists, go with that. 5582 */ 5583 5584 dac_granted = 0; 5585 5586 /* Check the owner. */ 5587 if (cred->cr_uid == file_uid) { 5588 dac_granted |= VADMIN; 5589 if (file_mode & S_IXUSR) 5590 dac_granted |= VEXEC; 5591 if (file_mode & S_IRUSR) 5592 dac_granted |= VREAD; 5593 if (file_mode & S_IWUSR) 5594 dac_granted |= (VWRITE | VAPPEND); 5595 5596 if ((accmode & dac_granted) == accmode) 5597 return (0); 5598 5599 goto privcheck; 5600 } 5601 5602 /* Otherwise, check the groups (first match) */ 5603 if (groupmember(file_gid, cred)) { 5604 if (file_mode & S_IXGRP) 5605 dac_granted |= VEXEC; 5606 if (file_mode & S_IRGRP) 5607 dac_granted |= VREAD; 5608 if (file_mode & S_IWGRP) 5609 dac_granted |= (VWRITE | VAPPEND); 5610 5611 if ((accmode & dac_granted) == accmode) 5612 return (0); 5613 5614 goto privcheck; 5615 } 5616 5617 /* Otherwise, check everyone else. */ 5618 if (file_mode & S_IXOTH) 5619 dac_granted |= VEXEC; 5620 if (file_mode & S_IROTH) 5621 dac_granted |= VREAD; 5622 if (file_mode & S_IWOTH) 5623 dac_granted |= (VWRITE | VAPPEND); 5624 if ((accmode & dac_granted) == accmode) 5625 return (0); 5626 5627 privcheck: 5628 /* 5629 * Build a privilege mask to determine if the set of privileges 5630 * satisfies the requirements when combined with the granted mask 5631 * from above. For each privilege, if the privilege is required, 5632 * bitwise or the request type onto the priv_granted mask. 5633 */ 5634 priv_granted = 0; 5635 5636 if (type == VDIR) { 5637 /* 5638 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5639 * requests, instead of PRIV_VFS_EXEC. 5640 */ 5641 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5642 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5643 priv_granted |= VEXEC; 5644 } else { 5645 /* 5646 * Ensure that at least one execute bit is on. Otherwise, 5647 * a privileged user will always succeed, and we don't want 5648 * this to happen unless the file really is executable. 5649 */ 5650 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5651 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5652 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5653 priv_granted |= VEXEC; 5654 } 5655 5656 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5657 !priv_check_cred(cred, PRIV_VFS_READ)) 5658 priv_granted |= VREAD; 5659 5660 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5661 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5662 priv_granted |= (VWRITE | VAPPEND); 5663 5664 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5665 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5666 priv_granted |= VADMIN; 5667 5668 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5669 return (0); 5670 } 5671 5672 return ((accmode & VADMIN) ? EPERM : EACCES); 5673 } 5674 5675 /* 5676 * Credential check based on process requesting service, and per-attribute 5677 * permissions. 5678 */ 5679 int 5680 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5681 struct thread *td, accmode_t accmode) 5682 { 5683 5684 /* 5685 * Kernel-invoked always succeeds. 5686 */ 5687 if (cred == NOCRED) 5688 return (0); 5689 5690 /* 5691 * Do not allow privileged processes in jail to directly manipulate 5692 * system attributes. 5693 */ 5694 switch (attrnamespace) { 5695 case EXTATTR_NAMESPACE_SYSTEM: 5696 /* Potentially should be: return (EPERM); */ 5697 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5698 case EXTATTR_NAMESPACE_USER: 5699 return (VOP_ACCESS(vp, accmode, cred, td)); 5700 default: 5701 return (EPERM); 5702 } 5703 } 5704 5705 #ifdef DEBUG_VFS_LOCKS 5706 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5707 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5708 "Drop into debugger on lock violation"); 5709 5710 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5711 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5712 0, "Check for interlock across VOPs"); 5713 5714 int vfs_badlock_print = 1; /* Print lock violations. */ 5715 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5716 0, "Print lock violations"); 5717 5718 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5719 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5720 0, "Print vnode details on lock violations"); 5721 5722 #ifdef KDB 5723 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5724 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5725 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5726 #endif 5727 5728 static void 5729 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5730 { 5731 5732 #ifdef KDB 5733 if (vfs_badlock_backtrace) 5734 kdb_backtrace(); 5735 #endif 5736 if (vfs_badlock_vnode) 5737 vn_printf(vp, "vnode "); 5738 if (vfs_badlock_print) 5739 printf("%s: %p %s\n", str, (void *)vp, msg); 5740 if (vfs_badlock_ddb) 5741 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5742 } 5743 5744 void 5745 assert_vi_locked(struct vnode *vp, const char *str) 5746 { 5747 5748 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5749 vfs_badlock("interlock is not locked but should be", str, vp); 5750 } 5751 5752 void 5753 assert_vi_unlocked(struct vnode *vp, const char *str) 5754 { 5755 5756 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5757 vfs_badlock("interlock is locked but should not be", str, vp); 5758 } 5759 5760 void 5761 assert_vop_locked(struct vnode *vp, const char *str) 5762 { 5763 if (KERNEL_PANICKED() || vp == NULL) 5764 return; 5765 5766 #ifdef WITNESS 5767 if ((vp->v_irflag & VIRF_CROSSMP) == 0 && 5768 witness_is_owned(&vp->v_vnlock->lock_object) == -1) 5769 #else 5770 int locked = VOP_ISLOCKED(vp); 5771 if (locked == 0 || locked == LK_EXCLOTHER) 5772 #endif 5773 vfs_badlock("is not locked but should be", str, vp); 5774 } 5775 5776 void 5777 assert_vop_unlocked(struct vnode *vp, const char *str) 5778 { 5779 if (KERNEL_PANICKED() || vp == NULL) 5780 return; 5781 5782 #ifdef WITNESS 5783 if ((vp->v_irflag & VIRF_CROSSMP) == 0 && 5784 witness_is_owned(&vp->v_vnlock->lock_object) == 1) 5785 #else 5786 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5787 #endif 5788 vfs_badlock("is locked but should not be", str, vp); 5789 } 5790 5791 void 5792 assert_vop_elocked(struct vnode *vp, const char *str) 5793 { 5794 if (KERNEL_PANICKED() || vp == NULL) 5795 return; 5796 5797 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5798 vfs_badlock("is not exclusive locked but should be", str, vp); 5799 } 5800 #endif /* DEBUG_VFS_LOCKS */ 5801 5802 void 5803 vop_rename_fail(struct vop_rename_args *ap) 5804 { 5805 5806 if (ap->a_tvp != NULL) 5807 vput(ap->a_tvp); 5808 if (ap->a_tdvp == ap->a_tvp) 5809 vrele(ap->a_tdvp); 5810 else 5811 vput(ap->a_tdvp); 5812 vrele(ap->a_fdvp); 5813 vrele(ap->a_fvp); 5814 } 5815 5816 void 5817 vop_rename_pre(void *ap) 5818 { 5819 struct vop_rename_args *a = ap; 5820 5821 #ifdef DEBUG_VFS_LOCKS 5822 if (a->a_tvp) 5823 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5824 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5825 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5826 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5827 5828 /* Check the source (from). */ 5829 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5830 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5831 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5832 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5833 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5834 5835 /* Check the target. */ 5836 if (a->a_tvp) 5837 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5838 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5839 #endif 5840 /* 5841 * It may be tempting to add vn_seqc_write_begin/end calls here and 5842 * in vop_rename_post but that's not going to work out since some 5843 * filesystems relookup vnodes mid-rename. This is probably a bug. 5844 * 5845 * For now filesystems are expected to do the relevant calls after they 5846 * decide what vnodes to operate on. 5847 */ 5848 if (a->a_tdvp != a->a_fdvp) 5849 vhold(a->a_fdvp); 5850 if (a->a_tvp != a->a_fvp) 5851 vhold(a->a_fvp); 5852 vhold(a->a_tdvp); 5853 if (a->a_tvp) 5854 vhold(a->a_tvp); 5855 } 5856 5857 #ifdef DEBUG_VFS_LOCKS 5858 void 5859 vop_fplookup_vexec_debugpre(void *ap __unused) 5860 { 5861 5862 VFS_SMR_ASSERT_ENTERED(); 5863 } 5864 5865 void 5866 vop_fplookup_vexec_debugpost(void *ap, int rc) 5867 { 5868 struct vop_fplookup_vexec_args *a; 5869 struct vnode *vp; 5870 5871 a = ap; 5872 vp = a->a_vp; 5873 5874 VFS_SMR_ASSERT_ENTERED(); 5875 if (rc == EOPNOTSUPP) 5876 VNPASS(VN_IS_DOOMED(vp), vp); 5877 } 5878 5879 void 5880 vop_fplookup_symlink_debugpre(void *ap __unused) 5881 { 5882 5883 VFS_SMR_ASSERT_ENTERED(); 5884 } 5885 5886 void 5887 vop_fplookup_symlink_debugpost(void *ap __unused, int rc __unused) 5888 { 5889 5890 VFS_SMR_ASSERT_ENTERED(); 5891 } 5892 5893 static void 5894 vop_fsync_debugprepost(struct vnode *vp, const char *name) 5895 { 5896 if (vp->v_type == VCHR) 5897 ; 5898 /* 5899 * The shared vs. exclusive locking policy for fsync() 5900 * is actually determined by vp's write mount as indicated 5901 * by VOP_GETWRITEMOUNT(), which for stacked filesystems 5902 * may not be the same as vp->v_mount. However, if the 5903 * underlying filesystem which really handles the fsync() 5904 * supports shared locking, the stacked filesystem must also 5905 * be prepared for its VOP_FSYNC() operation to be called 5906 * with only a shared lock. On the other hand, if the 5907 * stacked filesystem claims support for shared write 5908 * locking but the underlying filesystem does not, and the 5909 * caller incorrectly uses a shared lock, this condition 5910 * should still be caught when the stacked filesystem 5911 * invokes VOP_FSYNC() on the underlying filesystem. 5912 */ 5913 else if (MNT_SHARED_WRITES(vp->v_mount)) 5914 ASSERT_VOP_LOCKED(vp, name); 5915 else 5916 ASSERT_VOP_ELOCKED(vp, name); 5917 } 5918 5919 void 5920 vop_fsync_debugpre(void *a) 5921 { 5922 struct vop_fsync_args *ap; 5923 5924 ap = a; 5925 vop_fsync_debugprepost(ap->a_vp, "fsync"); 5926 } 5927 5928 void 5929 vop_fsync_debugpost(void *a, int rc __unused) 5930 { 5931 struct vop_fsync_args *ap; 5932 5933 ap = a; 5934 vop_fsync_debugprepost(ap->a_vp, "fsync"); 5935 } 5936 5937 void 5938 vop_fdatasync_debugpre(void *a) 5939 { 5940 struct vop_fdatasync_args *ap; 5941 5942 ap = a; 5943 vop_fsync_debugprepost(ap->a_vp, "fsync"); 5944 } 5945 5946 void 5947 vop_fdatasync_debugpost(void *a, int rc __unused) 5948 { 5949 struct vop_fdatasync_args *ap; 5950 5951 ap = a; 5952 vop_fsync_debugprepost(ap->a_vp, "fsync"); 5953 } 5954 5955 void 5956 vop_strategy_debugpre(void *ap) 5957 { 5958 struct vop_strategy_args *a; 5959 struct buf *bp; 5960 5961 a = ap; 5962 bp = a->a_bp; 5963 5964 /* 5965 * Cluster ops lock their component buffers but not the IO container. 5966 */ 5967 if ((bp->b_flags & B_CLUSTER) != 0) 5968 return; 5969 5970 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5971 if (vfs_badlock_print) 5972 printf( 5973 "VOP_STRATEGY: bp is not locked but should be\n"); 5974 if (vfs_badlock_ddb) 5975 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5976 } 5977 } 5978 5979 void 5980 vop_lock_debugpre(void *ap) 5981 { 5982 struct vop_lock1_args *a = ap; 5983 5984 if ((a->a_flags & LK_INTERLOCK) == 0) 5985 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5986 else 5987 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5988 } 5989 5990 void 5991 vop_lock_debugpost(void *ap, int rc) 5992 { 5993 struct vop_lock1_args *a = ap; 5994 5995 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5996 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5997 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5998 } 5999 6000 void 6001 vop_unlock_debugpre(void *ap) 6002 { 6003 struct vop_unlock_args *a = ap; 6004 struct vnode *vp = a->a_vp; 6005 6006 VNPASS(vn_get_state(vp) != VSTATE_UNINITIALIZED, vp); 6007 ASSERT_VOP_LOCKED(vp, "VOP_UNLOCK"); 6008 } 6009 6010 void 6011 vop_need_inactive_debugpre(void *ap) 6012 { 6013 struct vop_need_inactive_args *a = ap; 6014 6015 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 6016 } 6017 6018 void 6019 vop_need_inactive_debugpost(void *ap, int rc) 6020 { 6021 struct vop_need_inactive_args *a = ap; 6022 6023 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 6024 } 6025 #endif 6026 6027 void 6028 vop_create_pre(void *ap) 6029 { 6030 struct vop_create_args *a; 6031 struct vnode *dvp; 6032 6033 a = ap; 6034 dvp = a->a_dvp; 6035 vn_seqc_write_begin(dvp); 6036 } 6037 6038 void 6039 vop_create_post(void *ap, int rc) 6040 { 6041 struct vop_create_args *a; 6042 struct vnode *dvp; 6043 6044 a = ap; 6045 dvp = a->a_dvp; 6046 vn_seqc_write_end(dvp); 6047 if (!rc) 6048 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 6049 } 6050 6051 void 6052 vop_whiteout_pre(void *ap) 6053 { 6054 struct vop_whiteout_args *a; 6055 struct vnode *dvp; 6056 6057 a = ap; 6058 dvp = a->a_dvp; 6059 vn_seqc_write_begin(dvp); 6060 } 6061 6062 void 6063 vop_whiteout_post(void *ap, int rc) 6064 { 6065 struct vop_whiteout_args *a; 6066 struct vnode *dvp; 6067 6068 a = ap; 6069 dvp = a->a_dvp; 6070 vn_seqc_write_end(dvp); 6071 } 6072 6073 void 6074 vop_deleteextattr_pre(void *ap) 6075 { 6076 struct vop_deleteextattr_args *a; 6077 struct vnode *vp; 6078 6079 a = ap; 6080 vp = a->a_vp; 6081 vn_seqc_write_begin(vp); 6082 } 6083 6084 void 6085 vop_deleteextattr_post(void *ap, int rc) 6086 { 6087 struct vop_deleteextattr_args *a; 6088 struct vnode *vp; 6089 6090 a = ap; 6091 vp = a->a_vp; 6092 vn_seqc_write_end(vp); 6093 if (!rc) 6094 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 6095 } 6096 6097 void 6098 vop_link_pre(void *ap) 6099 { 6100 struct vop_link_args *a; 6101 struct vnode *vp, *tdvp; 6102 6103 a = ap; 6104 vp = a->a_vp; 6105 tdvp = a->a_tdvp; 6106 vn_seqc_write_begin(vp); 6107 vn_seqc_write_begin(tdvp); 6108 } 6109 6110 void 6111 vop_link_post(void *ap, int rc) 6112 { 6113 struct vop_link_args *a; 6114 struct vnode *vp, *tdvp; 6115 6116 a = ap; 6117 vp = a->a_vp; 6118 tdvp = a->a_tdvp; 6119 vn_seqc_write_end(vp); 6120 vn_seqc_write_end(tdvp); 6121 if (!rc) { 6122 VFS_KNOTE_LOCKED(vp, NOTE_LINK); 6123 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE); 6124 } 6125 } 6126 6127 void 6128 vop_mkdir_pre(void *ap) 6129 { 6130 struct vop_mkdir_args *a; 6131 struct vnode *dvp; 6132 6133 a = ap; 6134 dvp = a->a_dvp; 6135 vn_seqc_write_begin(dvp); 6136 } 6137 6138 void 6139 vop_mkdir_post(void *ap, int rc) 6140 { 6141 struct vop_mkdir_args *a; 6142 struct vnode *dvp; 6143 6144 a = ap; 6145 dvp = a->a_dvp; 6146 vn_seqc_write_end(dvp); 6147 if (!rc) 6148 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 6149 } 6150 6151 #ifdef DEBUG_VFS_LOCKS 6152 void 6153 vop_mkdir_debugpost(void *ap, int rc) 6154 { 6155 struct vop_mkdir_args *a; 6156 6157 a = ap; 6158 if (!rc) 6159 cache_validate(a->a_dvp, *a->a_vpp, a->a_cnp); 6160 } 6161 #endif 6162 6163 void 6164 vop_mknod_pre(void *ap) 6165 { 6166 struct vop_mknod_args *a; 6167 struct vnode *dvp; 6168 6169 a = ap; 6170 dvp = a->a_dvp; 6171 vn_seqc_write_begin(dvp); 6172 } 6173 6174 void 6175 vop_mknod_post(void *ap, int rc) 6176 { 6177 struct vop_mknod_args *a; 6178 struct vnode *dvp; 6179 6180 a = ap; 6181 dvp = a->a_dvp; 6182 vn_seqc_write_end(dvp); 6183 if (!rc) 6184 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 6185 } 6186 6187 void 6188 vop_reclaim_post(void *ap, int rc) 6189 { 6190 struct vop_reclaim_args *a; 6191 struct vnode *vp; 6192 6193 a = ap; 6194 vp = a->a_vp; 6195 ASSERT_VOP_IN_SEQC(vp); 6196 if (!rc) 6197 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE); 6198 } 6199 6200 void 6201 vop_remove_pre(void *ap) 6202 { 6203 struct vop_remove_args *a; 6204 struct vnode *dvp, *vp; 6205 6206 a = ap; 6207 dvp = a->a_dvp; 6208 vp = a->a_vp; 6209 vn_seqc_write_begin(dvp); 6210 vn_seqc_write_begin(vp); 6211 } 6212 6213 void 6214 vop_remove_post(void *ap, int rc) 6215 { 6216 struct vop_remove_args *a; 6217 struct vnode *dvp, *vp; 6218 6219 a = ap; 6220 dvp = a->a_dvp; 6221 vp = a->a_vp; 6222 vn_seqc_write_end(dvp); 6223 vn_seqc_write_end(vp); 6224 if (!rc) { 6225 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 6226 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 6227 } 6228 } 6229 6230 void 6231 vop_rename_post(void *ap, int rc) 6232 { 6233 struct vop_rename_args *a = ap; 6234 long hint; 6235 6236 if (!rc) { 6237 hint = NOTE_WRITE; 6238 if (a->a_fdvp == a->a_tdvp) { 6239 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 6240 hint |= NOTE_LINK; 6241 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 6242 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 6243 } else { 6244 hint |= NOTE_EXTEND; 6245 if (a->a_fvp->v_type == VDIR) 6246 hint |= NOTE_LINK; 6247 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 6248 6249 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 6250 a->a_tvp->v_type == VDIR) 6251 hint &= ~NOTE_LINK; 6252 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 6253 } 6254 6255 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 6256 if (a->a_tvp) 6257 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 6258 } 6259 if (a->a_tdvp != a->a_fdvp) 6260 vdrop(a->a_fdvp); 6261 if (a->a_tvp != a->a_fvp) 6262 vdrop(a->a_fvp); 6263 vdrop(a->a_tdvp); 6264 if (a->a_tvp) 6265 vdrop(a->a_tvp); 6266 } 6267 6268 void 6269 vop_rmdir_pre(void *ap) 6270 { 6271 struct vop_rmdir_args *a; 6272 struct vnode *dvp, *vp; 6273 6274 a = ap; 6275 dvp = a->a_dvp; 6276 vp = a->a_vp; 6277 vn_seqc_write_begin(dvp); 6278 vn_seqc_write_begin(vp); 6279 } 6280 6281 void 6282 vop_rmdir_post(void *ap, int rc) 6283 { 6284 struct vop_rmdir_args *a; 6285 struct vnode *dvp, *vp; 6286 6287 a = ap; 6288 dvp = a->a_dvp; 6289 vp = a->a_vp; 6290 vn_seqc_write_end(dvp); 6291 vn_seqc_write_end(vp); 6292 if (!rc) { 6293 vp->v_vflag |= VV_UNLINKED; 6294 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 6295 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 6296 } 6297 } 6298 6299 void 6300 vop_setattr_pre(void *ap) 6301 { 6302 struct vop_setattr_args *a; 6303 struct vnode *vp; 6304 6305 a = ap; 6306 vp = a->a_vp; 6307 vn_seqc_write_begin(vp); 6308 } 6309 6310 void 6311 vop_setattr_post(void *ap, int rc) 6312 { 6313 struct vop_setattr_args *a; 6314 struct vnode *vp; 6315 6316 a = ap; 6317 vp = a->a_vp; 6318 vn_seqc_write_end(vp); 6319 if (!rc) 6320 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 6321 } 6322 6323 void 6324 vop_setacl_pre(void *ap) 6325 { 6326 struct vop_setacl_args *a; 6327 struct vnode *vp; 6328 6329 a = ap; 6330 vp = a->a_vp; 6331 vn_seqc_write_begin(vp); 6332 } 6333 6334 void 6335 vop_setacl_post(void *ap, int rc __unused) 6336 { 6337 struct vop_setacl_args *a; 6338 struct vnode *vp; 6339 6340 a = ap; 6341 vp = a->a_vp; 6342 vn_seqc_write_end(vp); 6343 } 6344 6345 void 6346 vop_setextattr_pre(void *ap) 6347 { 6348 struct vop_setextattr_args *a; 6349 struct vnode *vp; 6350 6351 a = ap; 6352 vp = a->a_vp; 6353 vn_seqc_write_begin(vp); 6354 } 6355 6356 void 6357 vop_setextattr_post(void *ap, int rc) 6358 { 6359 struct vop_setextattr_args *a; 6360 struct vnode *vp; 6361 6362 a = ap; 6363 vp = a->a_vp; 6364 vn_seqc_write_end(vp); 6365 if (!rc) 6366 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 6367 } 6368 6369 void 6370 vop_symlink_pre(void *ap) 6371 { 6372 struct vop_symlink_args *a; 6373 struct vnode *dvp; 6374 6375 a = ap; 6376 dvp = a->a_dvp; 6377 vn_seqc_write_begin(dvp); 6378 } 6379 6380 void 6381 vop_symlink_post(void *ap, int rc) 6382 { 6383 struct vop_symlink_args *a; 6384 struct vnode *dvp; 6385 6386 a = ap; 6387 dvp = a->a_dvp; 6388 vn_seqc_write_end(dvp); 6389 if (!rc) 6390 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 6391 } 6392 6393 void 6394 vop_open_post(void *ap, int rc) 6395 { 6396 struct vop_open_args *a = ap; 6397 6398 if (!rc) 6399 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 6400 } 6401 6402 void 6403 vop_close_post(void *ap, int rc) 6404 { 6405 struct vop_close_args *a = ap; 6406 6407 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 6408 !VN_IS_DOOMED(a->a_vp))) { 6409 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 6410 NOTE_CLOSE_WRITE : NOTE_CLOSE); 6411 } 6412 } 6413 6414 void 6415 vop_read_post(void *ap, int rc) 6416 { 6417 struct vop_read_args *a = ap; 6418 6419 if (!rc) 6420 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 6421 } 6422 6423 void 6424 vop_read_pgcache_post(void *ap, int rc) 6425 { 6426 struct vop_read_pgcache_args *a = ap; 6427 6428 if (!rc) 6429 VFS_KNOTE_UNLOCKED(a->a_vp, NOTE_READ); 6430 } 6431 6432 void 6433 vop_readdir_post(void *ap, int rc) 6434 { 6435 struct vop_readdir_args *a = ap; 6436 6437 if (!rc) 6438 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 6439 } 6440 6441 static struct knlist fs_knlist; 6442 6443 static void 6444 vfs_event_init(void *arg) 6445 { 6446 knlist_init_mtx(&fs_knlist, NULL); 6447 } 6448 /* XXX - correct order? */ 6449 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 6450 6451 void 6452 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 6453 { 6454 6455 KNOTE_UNLOCKED(&fs_knlist, event); 6456 } 6457 6458 static int filt_fsattach(struct knote *kn); 6459 static void filt_fsdetach(struct knote *kn); 6460 static int filt_fsevent(struct knote *kn, long hint); 6461 6462 struct filterops fs_filtops = { 6463 .f_isfd = 0, 6464 .f_attach = filt_fsattach, 6465 .f_detach = filt_fsdetach, 6466 .f_event = filt_fsevent 6467 }; 6468 6469 static int 6470 filt_fsattach(struct knote *kn) 6471 { 6472 6473 kn->kn_flags |= EV_CLEAR; 6474 knlist_add(&fs_knlist, kn, 0); 6475 return (0); 6476 } 6477 6478 static void 6479 filt_fsdetach(struct knote *kn) 6480 { 6481 6482 knlist_remove(&fs_knlist, kn, 0); 6483 } 6484 6485 static int 6486 filt_fsevent(struct knote *kn, long hint) 6487 { 6488 6489 kn->kn_fflags |= kn->kn_sfflags & hint; 6490 6491 return (kn->kn_fflags != 0); 6492 } 6493 6494 static int 6495 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 6496 { 6497 struct vfsidctl vc; 6498 int error; 6499 struct mount *mp; 6500 6501 error = SYSCTL_IN(req, &vc, sizeof(vc)); 6502 if (error) 6503 return (error); 6504 if (vc.vc_vers != VFS_CTL_VERS1) 6505 return (EINVAL); 6506 mp = vfs_getvfs(&vc.vc_fsid); 6507 if (mp == NULL) 6508 return (ENOENT); 6509 /* ensure that a specific sysctl goes to the right filesystem. */ 6510 if (strcmp(vc.vc_fstypename, "*") != 0 && 6511 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 6512 vfs_rel(mp); 6513 return (EINVAL); 6514 } 6515 VCTLTOREQ(&vc, req); 6516 error = VFS_SYSCTL(mp, vc.vc_op, req); 6517 vfs_rel(mp); 6518 return (error); 6519 } 6520 6521 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 6522 NULL, 0, sysctl_vfs_ctl, "", 6523 "Sysctl by fsid"); 6524 6525 /* 6526 * Function to initialize a va_filerev field sensibly. 6527 * XXX: Wouldn't a random number make a lot more sense ?? 6528 */ 6529 u_quad_t 6530 init_va_filerev(void) 6531 { 6532 struct bintime bt; 6533 6534 getbinuptime(&bt); 6535 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 6536 } 6537 6538 static int filt_vfsread(struct knote *kn, long hint); 6539 static int filt_vfswrite(struct knote *kn, long hint); 6540 static int filt_vfsvnode(struct knote *kn, long hint); 6541 static void filt_vfsdetach(struct knote *kn); 6542 static struct filterops vfsread_filtops = { 6543 .f_isfd = 1, 6544 .f_detach = filt_vfsdetach, 6545 .f_event = filt_vfsread 6546 }; 6547 static struct filterops vfswrite_filtops = { 6548 .f_isfd = 1, 6549 .f_detach = filt_vfsdetach, 6550 .f_event = filt_vfswrite 6551 }; 6552 static struct filterops vfsvnode_filtops = { 6553 .f_isfd = 1, 6554 .f_detach = filt_vfsdetach, 6555 .f_event = filt_vfsvnode 6556 }; 6557 6558 static void 6559 vfs_knllock(void *arg) 6560 { 6561 struct vnode *vp = arg; 6562 6563 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 6564 } 6565 6566 static void 6567 vfs_knlunlock(void *arg) 6568 { 6569 struct vnode *vp = arg; 6570 6571 VOP_UNLOCK(vp); 6572 } 6573 6574 static void 6575 vfs_knl_assert_lock(void *arg, int what) 6576 { 6577 #ifdef DEBUG_VFS_LOCKS 6578 struct vnode *vp = arg; 6579 6580 if (what == LA_LOCKED) 6581 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 6582 else 6583 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 6584 #endif 6585 } 6586 6587 int 6588 vfs_kqfilter(struct vop_kqfilter_args *ap) 6589 { 6590 struct vnode *vp = ap->a_vp; 6591 struct knote *kn = ap->a_kn; 6592 struct knlist *knl; 6593 6594 KASSERT(vp->v_type != VFIFO || (kn->kn_filter != EVFILT_READ && 6595 kn->kn_filter != EVFILT_WRITE), 6596 ("READ/WRITE filter on a FIFO leaked through")); 6597 switch (kn->kn_filter) { 6598 case EVFILT_READ: 6599 kn->kn_fop = &vfsread_filtops; 6600 break; 6601 case EVFILT_WRITE: 6602 kn->kn_fop = &vfswrite_filtops; 6603 break; 6604 case EVFILT_VNODE: 6605 kn->kn_fop = &vfsvnode_filtops; 6606 break; 6607 default: 6608 return (EINVAL); 6609 } 6610 6611 kn->kn_hook = (caddr_t)vp; 6612 6613 v_addpollinfo(vp); 6614 if (vp->v_pollinfo == NULL) 6615 return (ENOMEM); 6616 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 6617 vhold(vp); 6618 knlist_add(knl, kn, 0); 6619 6620 return (0); 6621 } 6622 6623 /* 6624 * Detach knote from vnode 6625 */ 6626 static void 6627 filt_vfsdetach(struct knote *kn) 6628 { 6629 struct vnode *vp = (struct vnode *)kn->kn_hook; 6630 6631 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 6632 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 6633 vdrop(vp); 6634 } 6635 6636 /*ARGSUSED*/ 6637 static int 6638 filt_vfsread(struct knote *kn, long hint) 6639 { 6640 struct vnode *vp = (struct vnode *)kn->kn_hook; 6641 off_t size; 6642 int res; 6643 6644 /* 6645 * filesystem is gone, so set the EOF flag and schedule 6646 * the knote for deletion. 6647 */ 6648 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6649 VI_LOCK(vp); 6650 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6651 VI_UNLOCK(vp); 6652 return (1); 6653 } 6654 6655 if (vn_getsize_locked(vp, &size, curthread->td_ucred) != 0) 6656 return (0); 6657 6658 VI_LOCK(vp); 6659 kn->kn_data = size - kn->kn_fp->f_offset; 6660 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 6661 VI_UNLOCK(vp); 6662 return (res); 6663 } 6664 6665 /*ARGSUSED*/ 6666 static int 6667 filt_vfswrite(struct knote *kn, long hint) 6668 { 6669 struct vnode *vp = (struct vnode *)kn->kn_hook; 6670 6671 VI_LOCK(vp); 6672 6673 /* 6674 * filesystem is gone, so set the EOF flag and schedule 6675 * the knote for deletion. 6676 */ 6677 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 6678 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6679 6680 kn->kn_data = 0; 6681 VI_UNLOCK(vp); 6682 return (1); 6683 } 6684 6685 static int 6686 filt_vfsvnode(struct knote *kn, long hint) 6687 { 6688 struct vnode *vp = (struct vnode *)kn->kn_hook; 6689 int res; 6690 6691 VI_LOCK(vp); 6692 if (kn->kn_sfflags & hint) 6693 kn->kn_fflags |= hint; 6694 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6695 kn->kn_flags |= EV_EOF; 6696 VI_UNLOCK(vp); 6697 return (1); 6698 } 6699 res = (kn->kn_fflags != 0); 6700 VI_UNLOCK(vp); 6701 return (res); 6702 } 6703 6704 int 6705 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 6706 { 6707 int error; 6708 6709 if (dp->d_reclen > ap->a_uio->uio_resid) 6710 return (ENAMETOOLONG); 6711 error = uiomove(dp, dp->d_reclen, ap->a_uio); 6712 if (error) { 6713 if (ap->a_ncookies != NULL) { 6714 if (ap->a_cookies != NULL) 6715 free(ap->a_cookies, M_TEMP); 6716 ap->a_cookies = NULL; 6717 *ap->a_ncookies = 0; 6718 } 6719 return (error); 6720 } 6721 if (ap->a_ncookies == NULL) 6722 return (0); 6723 6724 KASSERT(ap->a_cookies, 6725 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 6726 6727 *ap->a_cookies = realloc(*ap->a_cookies, 6728 (*ap->a_ncookies + 1) * sizeof(uint64_t), M_TEMP, M_WAITOK | M_ZERO); 6729 (*ap->a_cookies)[*ap->a_ncookies] = off; 6730 *ap->a_ncookies += 1; 6731 return (0); 6732 } 6733 6734 /* 6735 * The purpose of this routine is to remove granularity from accmode_t, 6736 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 6737 * VADMIN and VAPPEND. 6738 * 6739 * If it returns 0, the caller is supposed to continue with the usual 6740 * access checks using 'accmode' as modified by this routine. If it 6741 * returns nonzero value, the caller is supposed to return that value 6742 * as errno. 6743 * 6744 * Note that after this routine runs, accmode may be zero. 6745 */ 6746 int 6747 vfs_unixify_accmode(accmode_t *accmode) 6748 { 6749 /* 6750 * There is no way to specify explicit "deny" rule using 6751 * file mode or POSIX.1e ACLs. 6752 */ 6753 if (*accmode & VEXPLICIT_DENY) { 6754 *accmode = 0; 6755 return (0); 6756 } 6757 6758 /* 6759 * None of these can be translated into usual access bits. 6760 * Also, the common case for NFSv4 ACLs is to not contain 6761 * either of these bits. Caller should check for VWRITE 6762 * on the containing directory instead. 6763 */ 6764 if (*accmode & (VDELETE_CHILD | VDELETE)) 6765 return (EPERM); 6766 6767 if (*accmode & VADMIN_PERMS) { 6768 *accmode &= ~VADMIN_PERMS; 6769 *accmode |= VADMIN; 6770 } 6771 6772 /* 6773 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6774 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6775 */ 6776 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6777 6778 return (0); 6779 } 6780 6781 /* 6782 * Clear out a doomed vnode (if any) and replace it with a new one as long 6783 * as the fs is not being unmounted. Return the root vnode to the caller. 6784 */ 6785 static int __noinline 6786 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6787 { 6788 struct vnode *vp; 6789 int error; 6790 6791 restart: 6792 if (mp->mnt_rootvnode != NULL) { 6793 MNT_ILOCK(mp); 6794 vp = mp->mnt_rootvnode; 6795 if (vp != NULL) { 6796 if (!VN_IS_DOOMED(vp)) { 6797 vrefact(vp); 6798 MNT_IUNLOCK(mp); 6799 error = vn_lock(vp, flags); 6800 if (error == 0) { 6801 *vpp = vp; 6802 return (0); 6803 } 6804 vrele(vp); 6805 goto restart; 6806 } 6807 /* 6808 * Clear the old one. 6809 */ 6810 mp->mnt_rootvnode = NULL; 6811 } 6812 MNT_IUNLOCK(mp); 6813 if (vp != NULL) { 6814 vfs_op_barrier_wait(mp); 6815 vrele(vp); 6816 } 6817 } 6818 error = VFS_CACHEDROOT(mp, flags, vpp); 6819 if (error != 0) 6820 return (error); 6821 if (mp->mnt_vfs_ops == 0) { 6822 MNT_ILOCK(mp); 6823 if (mp->mnt_vfs_ops != 0) { 6824 MNT_IUNLOCK(mp); 6825 return (0); 6826 } 6827 if (mp->mnt_rootvnode == NULL) { 6828 vrefact(*vpp); 6829 mp->mnt_rootvnode = *vpp; 6830 } else { 6831 if (mp->mnt_rootvnode != *vpp) { 6832 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6833 panic("%s: mismatch between vnode returned " 6834 " by VFS_CACHEDROOT and the one cached " 6835 " (%p != %p)", 6836 __func__, *vpp, mp->mnt_rootvnode); 6837 } 6838 } 6839 } 6840 MNT_IUNLOCK(mp); 6841 } 6842 return (0); 6843 } 6844 6845 int 6846 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6847 { 6848 struct mount_pcpu *mpcpu; 6849 struct vnode *vp; 6850 int error; 6851 6852 if (!vfs_op_thread_enter(mp, mpcpu)) 6853 return (vfs_cache_root_fallback(mp, flags, vpp)); 6854 vp = atomic_load_ptr(&mp->mnt_rootvnode); 6855 if (vp == NULL || VN_IS_DOOMED(vp)) { 6856 vfs_op_thread_exit(mp, mpcpu); 6857 return (vfs_cache_root_fallback(mp, flags, vpp)); 6858 } 6859 vrefact(vp); 6860 vfs_op_thread_exit(mp, mpcpu); 6861 error = vn_lock(vp, flags); 6862 if (error != 0) { 6863 vrele(vp); 6864 return (vfs_cache_root_fallback(mp, flags, vpp)); 6865 } 6866 *vpp = vp; 6867 return (0); 6868 } 6869 6870 struct vnode * 6871 vfs_cache_root_clear(struct mount *mp) 6872 { 6873 struct vnode *vp; 6874 6875 /* 6876 * ops > 0 guarantees there is nobody who can see this vnode 6877 */ 6878 MPASS(mp->mnt_vfs_ops > 0); 6879 vp = mp->mnt_rootvnode; 6880 if (vp != NULL) 6881 vn_seqc_write_begin(vp); 6882 mp->mnt_rootvnode = NULL; 6883 return (vp); 6884 } 6885 6886 void 6887 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6888 { 6889 6890 MPASS(mp->mnt_vfs_ops > 0); 6891 vrefact(vp); 6892 mp->mnt_rootvnode = vp; 6893 } 6894 6895 /* 6896 * These are helper functions for filesystems to traverse all 6897 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6898 * 6899 * This interface replaces MNT_VNODE_FOREACH. 6900 */ 6901 6902 struct vnode * 6903 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6904 { 6905 struct vnode *vp; 6906 6907 maybe_yield(); 6908 MNT_ILOCK(mp); 6909 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6910 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6911 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6912 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6913 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6914 continue; 6915 VI_LOCK(vp); 6916 if (VN_IS_DOOMED(vp)) { 6917 VI_UNLOCK(vp); 6918 continue; 6919 } 6920 break; 6921 } 6922 if (vp == NULL) { 6923 __mnt_vnode_markerfree_all(mvp, mp); 6924 /* MNT_IUNLOCK(mp); -- done in above function */ 6925 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6926 return (NULL); 6927 } 6928 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6929 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6930 MNT_IUNLOCK(mp); 6931 return (vp); 6932 } 6933 6934 struct vnode * 6935 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6936 { 6937 struct vnode *vp; 6938 6939 *mvp = vn_alloc_marker(mp); 6940 MNT_ILOCK(mp); 6941 MNT_REF(mp); 6942 6943 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6944 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6945 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6946 continue; 6947 VI_LOCK(vp); 6948 if (VN_IS_DOOMED(vp)) { 6949 VI_UNLOCK(vp); 6950 continue; 6951 } 6952 break; 6953 } 6954 if (vp == NULL) { 6955 MNT_REL(mp); 6956 MNT_IUNLOCK(mp); 6957 vn_free_marker(*mvp); 6958 *mvp = NULL; 6959 return (NULL); 6960 } 6961 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6962 MNT_IUNLOCK(mp); 6963 return (vp); 6964 } 6965 6966 void 6967 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6968 { 6969 6970 if (*mvp == NULL) { 6971 MNT_IUNLOCK(mp); 6972 return; 6973 } 6974 6975 mtx_assert(MNT_MTX(mp), MA_OWNED); 6976 6977 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6978 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6979 MNT_REL(mp); 6980 MNT_IUNLOCK(mp); 6981 vn_free_marker(*mvp); 6982 *mvp = NULL; 6983 } 6984 6985 /* 6986 * These are helper functions for filesystems to traverse their 6987 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6988 */ 6989 static void 6990 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6991 { 6992 6993 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6994 6995 MNT_ILOCK(mp); 6996 MNT_REL(mp); 6997 MNT_IUNLOCK(mp); 6998 vn_free_marker(*mvp); 6999 *mvp = NULL; 7000 } 7001 7002 /* 7003 * Relock the mp mount vnode list lock with the vp vnode interlock in the 7004 * conventional lock order during mnt_vnode_next_lazy iteration. 7005 * 7006 * On entry, the mount vnode list lock is held and the vnode interlock is not. 7007 * The list lock is dropped and reacquired. On success, both locks are held. 7008 * On failure, the mount vnode list lock is held but the vnode interlock is 7009 * not, and the procedure may have yielded. 7010 */ 7011 static bool 7012 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 7013 struct vnode *vp) 7014 { 7015 7016 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 7017 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 7018 ("%s: bad marker", __func__)); 7019 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 7020 ("%s: inappropriate vnode", __func__)); 7021 ASSERT_VI_UNLOCKED(vp, __func__); 7022 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 7023 7024 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 7025 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 7026 7027 /* 7028 * Note we may be racing against vdrop which transitioned the hold 7029 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine, 7030 * if we are the only user after we get the interlock we will just 7031 * vdrop. 7032 */ 7033 vhold(vp); 7034 mtx_unlock(&mp->mnt_listmtx); 7035 VI_LOCK(vp); 7036 if (VN_IS_DOOMED(vp)) { 7037 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 7038 goto out_lost; 7039 } 7040 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 7041 /* 7042 * There is nothing to do if we are the last user. 7043 */ 7044 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 7045 goto out_lost; 7046 mtx_lock(&mp->mnt_listmtx); 7047 return (true); 7048 out_lost: 7049 vdropl(vp); 7050 maybe_yield(); 7051 mtx_lock(&mp->mnt_listmtx); 7052 return (false); 7053 } 7054 7055 static struct vnode * 7056 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 7057 void *cbarg) 7058 { 7059 struct vnode *vp; 7060 7061 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 7062 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 7063 restart: 7064 vp = TAILQ_NEXT(*mvp, v_lazylist); 7065 while (vp != NULL) { 7066 if (vp->v_type == VMARKER) { 7067 vp = TAILQ_NEXT(vp, v_lazylist); 7068 continue; 7069 } 7070 /* 7071 * See if we want to process the vnode. Note we may encounter a 7072 * long string of vnodes we don't care about and hog the list 7073 * as a result. Check for it and requeue the marker. 7074 */ 7075 VNPASS(!VN_IS_DOOMED(vp), vp); 7076 if (!cb(vp, cbarg)) { 7077 if (!should_yield()) { 7078 vp = TAILQ_NEXT(vp, v_lazylist); 7079 continue; 7080 } 7081 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 7082 v_lazylist); 7083 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 7084 v_lazylist); 7085 mtx_unlock(&mp->mnt_listmtx); 7086 kern_yield(PRI_USER); 7087 mtx_lock(&mp->mnt_listmtx); 7088 goto restart; 7089 } 7090 /* 7091 * Try-lock because this is the wrong lock order. 7092 */ 7093 if (!VI_TRYLOCK(vp) && 7094 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 7095 goto restart; 7096 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 7097 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 7098 ("alien vnode on the lazy list %p %p", vp, mp)); 7099 VNPASS(vp->v_mount == mp, vp); 7100 VNPASS(!VN_IS_DOOMED(vp), vp); 7101 break; 7102 } 7103 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 7104 7105 /* Check if we are done */ 7106 if (vp == NULL) { 7107 mtx_unlock(&mp->mnt_listmtx); 7108 mnt_vnode_markerfree_lazy(mvp, mp); 7109 return (NULL); 7110 } 7111 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 7112 mtx_unlock(&mp->mnt_listmtx); 7113 ASSERT_VI_LOCKED(vp, "lazy iter"); 7114 return (vp); 7115 } 7116 7117 struct vnode * 7118 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 7119 void *cbarg) 7120 { 7121 7122 maybe_yield(); 7123 mtx_lock(&mp->mnt_listmtx); 7124 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 7125 } 7126 7127 struct vnode * 7128 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 7129 void *cbarg) 7130 { 7131 struct vnode *vp; 7132 7133 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 7134 return (NULL); 7135 7136 *mvp = vn_alloc_marker(mp); 7137 MNT_ILOCK(mp); 7138 MNT_REF(mp); 7139 MNT_IUNLOCK(mp); 7140 7141 mtx_lock(&mp->mnt_listmtx); 7142 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 7143 if (vp == NULL) { 7144 mtx_unlock(&mp->mnt_listmtx); 7145 mnt_vnode_markerfree_lazy(mvp, mp); 7146 return (NULL); 7147 } 7148 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 7149 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 7150 } 7151 7152 void 7153 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 7154 { 7155 7156 if (*mvp == NULL) 7157 return; 7158 7159 mtx_lock(&mp->mnt_listmtx); 7160 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 7161 mtx_unlock(&mp->mnt_listmtx); 7162 mnt_vnode_markerfree_lazy(mvp, mp); 7163 } 7164 7165 int 7166 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 7167 { 7168 7169 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 7170 cnp->cn_flags &= ~NOEXECCHECK; 7171 return (0); 7172 } 7173 7174 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, curthread)); 7175 } 7176 7177 /* 7178 * Do not use this variant unless you have means other than the hold count 7179 * to prevent the vnode from getting freed. 7180 */ 7181 void 7182 vn_seqc_write_begin_locked(struct vnode *vp) 7183 { 7184 7185 ASSERT_VI_LOCKED(vp, __func__); 7186 VNPASS(vp->v_holdcnt > 0, vp); 7187 VNPASS(vp->v_seqc_users >= 0, vp); 7188 vp->v_seqc_users++; 7189 if (vp->v_seqc_users == 1) 7190 seqc_sleepable_write_begin(&vp->v_seqc); 7191 } 7192 7193 void 7194 vn_seqc_write_begin(struct vnode *vp) 7195 { 7196 7197 VI_LOCK(vp); 7198 vn_seqc_write_begin_locked(vp); 7199 VI_UNLOCK(vp); 7200 } 7201 7202 void 7203 vn_seqc_write_end_locked(struct vnode *vp) 7204 { 7205 7206 ASSERT_VI_LOCKED(vp, __func__); 7207 VNPASS(vp->v_seqc_users > 0, vp); 7208 vp->v_seqc_users--; 7209 if (vp->v_seqc_users == 0) 7210 seqc_sleepable_write_end(&vp->v_seqc); 7211 } 7212 7213 void 7214 vn_seqc_write_end(struct vnode *vp) 7215 { 7216 7217 VI_LOCK(vp); 7218 vn_seqc_write_end_locked(vp); 7219 VI_UNLOCK(vp); 7220 } 7221 7222 /* 7223 * Special case handling for allocating and freeing vnodes. 7224 * 7225 * The counter remains unchanged on free so that a doomed vnode will 7226 * keep testing as in modify as long as it is accessible with SMR. 7227 */ 7228 static void 7229 vn_seqc_init(struct vnode *vp) 7230 { 7231 7232 vp->v_seqc = 0; 7233 vp->v_seqc_users = 0; 7234 } 7235 7236 static void 7237 vn_seqc_write_end_free(struct vnode *vp) 7238 { 7239 7240 VNPASS(seqc_in_modify(vp->v_seqc), vp); 7241 VNPASS(vp->v_seqc_users == 1, vp); 7242 } 7243 7244 void 7245 vn_irflag_set_locked(struct vnode *vp, short toset) 7246 { 7247 short flags; 7248 7249 ASSERT_VI_LOCKED(vp, __func__); 7250 flags = vn_irflag_read(vp); 7251 VNASSERT((flags & toset) == 0, vp, 7252 ("%s: some of the passed flags already set (have %d, passed %d)\n", 7253 __func__, flags, toset)); 7254 atomic_store_short(&vp->v_irflag, flags | toset); 7255 } 7256 7257 void 7258 vn_irflag_set(struct vnode *vp, short toset) 7259 { 7260 7261 VI_LOCK(vp); 7262 vn_irflag_set_locked(vp, toset); 7263 VI_UNLOCK(vp); 7264 } 7265 7266 void 7267 vn_irflag_set_cond_locked(struct vnode *vp, short toset) 7268 { 7269 short flags; 7270 7271 ASSERT_VI_LOCKED(vp, __func__); 7272 flags = vn_irflag_read(vp); 7273 atomic_store_short(&vp->v_irflag, flags | toset); 7274 } 7275 7276 void 7277 vn_irflag_set_cond(struct vnode *vp, short toset) 7278 { 7279 7280 VI_LOCK(vp); 7281 vn_irflag_set_cond_locked(vp, toset); 7282 VI_UNLOCK(vp); 7283 } 7284 7285 void 7286 vn_irflag_unset_locked(struct vnode *vp, short tounset) 7287 { 7288 short flags; 7289 7290 ASSERT_VI_LOCKED(vp, __func__); 7291 flags = vn_irflag_read(vp); 7292 VNASSERT((flags & tounset) == tounset, vp, 7293 ("%s: some of the passed flags not set (have %d, passed %d)\n", 7294 __func__, flags, tounset)); 7295 atomic_store_short(&vp->v_irflag, flags & ~tounset); 7296 } 7297 7298 void 7299 vn_irflag_unset(struct vnode *vp, short tounset) 7300 { 7301 7302 VI_LOCK(vp); 7303 vn_irflag_unset_locked(vp, tounset); 7304 VI_UNLOCK(vp); 7305 } 7306 7307 int 7308 vn_getsize_locked(struct vnode *vp, off_t *size, struct ucred *cred) 7309 { 7310 struct vattr vattr; 7311 int error; 7312 7313 ASSERT_VOP_LOCKED(vp, __func__); 7314 error = VOP_GETATTR(vp, &vattr, cred); 7315 if (__predict_true(error == 0)) { 7316 if (vattr.va_size <= OFF_MAX) 7317 *size = vattr.va_size; 7318 else 7319 error = EFBIG; 7320 } 7321 return (error); 7322 } 7323 7324 int 7325 vn_getsize(struct vnode *vp, off_t *size, struct ucred *cred) 7326 { 7327 int error; 7328 7329 VOP_LOCK(vp, LK_SHARED); 7330 error = vn_getsize_locked(vp, size, cred); 7331 VOP_UNLOCK(vp); 7332 return (error); 7333 } 7334 7335 #ifdef INVARIANTS 7336 void 7337 vn_set_state_validate(struct vnode *vp, __enum_uint8(vstate) state) 7338 { 7339 7340 switch (vp->v_state) { 7341 case VSTATE_UNINITIALIZED: 7342 switch (state) { 7343 case VSTATE_CONSTRUCTED: 7344 case VSTATE_DESTROYING: 7345 return; 7346 default: 7347 break; 7348 } 7349 break; 7350 case VSTATE_CONSTRUCTED: 7351 ASSERT_VOP_ELOCKED(vp, __func__); 7352 switch (state) { 7353 case VSTATE_DESTROYING: 7354 return; 7355 default: 7356 break; 7357 } 7358 break; 7359 case VSTATE_DESTROYING: 7360 ASSERT_VOP_ELOCKED(vp, __func__); 7361 switch (state) { 7362 case VSTATE_DEAD: 7363 return; 7364 default: 7365 break; 7366 } 7367 break; 7368 case VSTATE_DEAD: 7369 switch (state) { 7370 case VSTATE_UNINITIALIZED: 7371 return; 7372 default: 7373 break; 7374 } 7375 break; 7376 } 7377 7378 vn_printf(vp, "invalid state transition %d -> %d\n", vp->v_state, state); 7379 panic("invalid state transition %d -> %d\n", vp->v_state, state); 7380 } 7381 #endif 7382