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. 2701 * 2702 * NOTE: xflags is passed as a constant, optimizing this inline function! 2703 */ 2704 static void 2705 buf_vlist_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)) == 0, 2717 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2718 bp->b_xflags |= xflags; 2719 if (xflags & BX_VNDIRTY) 2720 bv = &bo->bo_dirty; 2721 else 2722 bv = &bo->bo_clean; 2723 2724 /* 2725 * Keep the list ordered. Optimize empty list insertion. Assume 2726 * we tend to grow at the tail so lookup_le should usually be cheaper 2727 * than _ge. 2728 */ 2729 if (bv->bv_cnt == 0 || 2730 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2731 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2732 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2733 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2734 else 2735 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2736 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2737 if (error) 2738 panic("buf_vlist_add: Preallocated nodes insufficient."); 2739 bv->bv_cnt++; 2740 } 2741 2742 /* 2743 * Look up a buffer using the buffer tries. 2744 */ 2745 struct buf * 2746 gbincore(struct bufobj *bo, daddr_t lblkno) 2747 { 2748 struct buf *bp; 2749 2750 ASSERT_BO_LOCKED(bo); 2751 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2752 if (bp != NULL) 2753 return (bp); 2754 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno)); 2755 } 2756 2757 /* 2758 * Look up a buf using the buffer tries, without the bufobj lock. This relies 2759 * on SMR for safe lookup, and bufs being in a no-free zone to provide type 2760 * stability of the result. Like other lockless lookups, the found buf may 2761 * already be invalid by the time this function returns. 2762 */ 2763 struct buf * 2764 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno) 2765 { 2766 struct buf *bp; 2767 2768 ASSERT_BO_UNLOCKED(bo); 2769 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno); 2770 if (bp != NULL) 2771 return (bp); 2772 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno)); 2773 } 2774 2775 /* 2776 * Associate a buffer with a vnode. 2777 */ 2778 void 2779 bgetvp(struct vnode *vp, struct buf *bp) 2780 { 2781 struct bufobj *bo; 2782 2783 bo = &vp->v_bufobj; 2784 ASSERT_BO_WLOCKED(bo); 2785 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2786 2787 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2788 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2789 ("bgetvp: bp already attached! %p", bp)); 2790 2791 vhold(vp); 2792 bp->b_vp = vp; 2793 bp->b_bufobj = bo; 2794 /* 2795 * Insert onto list for new vnode. 2796 */ 2797 buf_vlist_add(bp, bo, BX_VNCLEAN); 2798 } 2799 2800 /* 2801 * Disassociate a buffer from a vnode. 2802 */ 2803 void 2804 brelvp(struct buf *bp) 2805 { 2806 struct bufobj *bo; 2807 struct vnode *vp; 2808 2809 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2810 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2811 2812 /* 2813 * Delete from old vnode list, if on one. 2814 */ 2815 vp = bp->b_vp; /* XXX */ 2816 bo = bp->b_bufobj; 2817 BO_LOCK(bo); 2818 buf_vlist_remove(bp); 2819 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2820 bo->bo_flag &= ~BO_ONWORKLST; 2821 mtx_lock(&sync_mtx); 2822 LIST_REMOVE(bo, bo_synclist); 2823 syncer_worklist_len--; 2824 mtx_unlock(&sync_mtx); 2825 } 2826 bp->b_vp = NULL; 2827 bp->b_bufobj = NULL; 2828 BO_UNLOCK(bo); 2829 vdrop(vp); 2830 } 2831 2832 /* 2833 * Add an item to the syncer work queue. 2834 */ 2835 static void 2836 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2837 { 2838 int slot; 2839 2840 ASSERT_BO_WLOCKED(bo); 2841 2842 mtx_lock(&sync_mtx); 2843 if (bo->bo_flag & BO_ONWORKLST) 2844 LIST_REMOVE(bo, bo_synclist); 2845 else { 2846 bo->bo_flag |= BO_ONWORKLST; 2847 syncer_worklist_len++; 2848 } 2849 2850 if (delay > syncer_maxdelay - 2) 2851 delay = syncer_maxdelay - 2; 2852 slot = (syncer_delayno + delay) & syncer_mask; 2853 2854 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2855 mtx_unlock(&sync_mtx); 2856 } 2857 2858 static int 2859 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2860 { 2861 int error, len; 2862 2863 mtx_lock(&sync_mtx); 2864 len = syncer_worklist_len - sync_vnode_count; 2865 mtx_unlock(&sync_mtx); 2866 error = SYSCTL_OUT(req, &len, sizeof(len)); 2867 return (error); 2868 } 2869 2870 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, 2871 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0, 2872 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2873 2874 static struct proc *updateproc; 2875 static void sched_sync(void); 2876 static struct kproc_desc up_kp = { 2877 "syncer", 2878 sched_sync, 2879 &updateproc 2880 }; 2881 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2882 2883 static int 2884 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2885 { 2886 struct vnode *vp; 2887 struct mount *mp; 2888 2889 *bo = LIST_FIRST(slp); 2890 if (*bo == NULL) 2891 return (0); 2892 vp = bo2vnode(*bo); 2893 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2894 return (1); 2895 /* 2896 * We use vhold in case the vnode does not 2897 * successfully sync. vhold prevents the vnode from 2898 * going away when we unlock the sync_mtx so that 2899 * we can acquire the vnode interlock. 2900 */ 2901 vholdl(vp); 2902 mtx_unlock(&sync_mtx); 2903 VI_UNLOCK(vp); 2904 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2905 vdrop(vp); 2906 mtx_lock(&sync_mtx); 2907 return (*bo == LIST_FIRST(slp)); 2908 } 2909 MPASSERT(mp == NULL || (curthread->td_pflags & TDP_IGNSUSP) != 0 || 2910 (mp->mnt_kern_flag & MNTK_SUSPENDED) == 0, mp, 2911 ("suspended mp syncing vp %p", vp)); 2912 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2913 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2914 VOP_UNLOCK(vp); 2915 vn_finished_write(mp); 2916 BO_LOCK(*bo); 2917 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2918 /* 2919 * Put us back on the worklist. The worklist 2920 * routine will remove us from our current 2921 * position and then add us back in at a later 2922 * position. 2923 */ 2924 vn_syncer_add_to_worklist(*bo, syncdelay); 2925 } 2926 BO_UNLOCK(*bo); 2927 vdrop(vp); 2928 mtx_lock(&sync_mtx); 2929 return (0); 2930 } 2931 2932 static int first_printf = 1; 2933 2934 /* 2935 * System filesystem synchronizer daemon. 2936 */ 2937 static void 2938 sched_sync(void) 2939 { 2940 struct synclist *next, *slp; 2941 struct bufobj *bo; 2942 long starttime; 2943 struct thread *td = curthread; 2944 int last_work_seen; 2945 int net_worklist_len; 2946 int syncer_final_iter; 2947 int error; 2948 2949 last_work_seen = 0; 2950 syncer_final_iter = 0; 2951 syncer_state = SYNCER_RUNNING; 2952 starttime = time_uptime; 2953 td->td_pflags |= TDP_NORUNNINGBUF; 2954 2955 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2956 SHUTDOWN_PRI_LAST); 2957 2958 mtx_lock(&sync_mtx); 2959 for (;;) { 2960 if (syncer_state == SYNCER_FINAL_DELAY && 2961 syncer_final_iter == 0) { 2962 mtx_unlock(&sync_mtx); 2963 kproc_suspend_check(td->td_proc); 2964 mtx_lock(&sync_mtx); 2965 } 2966 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2967 if (syncer_state != SYNCER_RUNNING && 2968 starttime != time_uptime) { 2969 if (first_printf) { 2970 printf("\nSyncing disks, vnodes remaining... "); 2971 first_printf = 0; 2972 } 2973 printf("%d ", net_worklist_len); 2974 } 2975 starttime = time_uptime; 2976 2977 /* 2978 * Push files whose dirty time has expired. Be careful 2979 * of interrupt race on slp queue. 2980 * 2981 * Skip over empty worklist slots when shutting down. 2982 */ 2983 do { 2984 slp = &syncer_workitem_pending[syncer_delayno]; 2985 syncer_delayno += 1; 2986 if (syncer_delayno == syncer_maxdelay) 2987 syncer_delayno = 0; 2988 next = &syncer_workitem_pending[syncer_delayno]; 2989 /* 2990 * If the worklist has wrapped since the 2991 * it was emptied of all but syncer vnodes, 2992 * switch to the FINAL_DELAY state and run 2993 * for one more second. 2994 */ 2995 if (syncer_state == SYNCER_SHUTTING_DOWN && 2996 net_worklist_len == 0 && 2997 last_work_seen == syncer_delayno) { 2998 syncer_state = SYNCER_FINAL_DELAY; 2999 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 3000 } 3001 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 3002 syncer_worklist_len > 0); 3003 3004 /* 3005 * Keep track of the last time there was anything 3006 * on the worklist other than syncer vnodes. 3007 * Return to the SHUTTING_DOWN state if any 3008 * new work appears. 3009 */ 3010 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 3011 last_work_seen = syncer_delayno; 3012 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 3013 syncer_state = SYNCER_SHUTTING_DOWN; 3014 while (!LIST_EMPTY(slp)) { 3015 error = sync_vnode(slp, &bo, td); 3016 if (error == 1) { 3017 LIST_REMOVE(bo, bo_synclist); 3018 LIST_INSERT_HEAD(next, bo, bo_synclist); 3019 continue; 3020 } 3021 3022 if (first_printf == 0) { 3023 /* 3024 * Drop the sync mutex, because some watchdog 3025 * drivers need to sleep while patting 3026 */ 3027 mtx_unlock(&sync_mtx); 3028 wdog_kern_pat(WD_LASTVAL); 3029 mtx_lock(&sync_mtx); 3030 } 3031 } 3032 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 3033 syncer_final_iter--; 3034 /* 3035 * The variable rushjob allows the kernel to speed up the 3036 * processing of the filesystem syncer process. A rushjob 3037 * value of N tells the filesystem syncer to process the next 3038 * N seconds worth of work on its queue ASAP. Currently rushjob 3039 * is used by the soft update code to speed up the filesystem 3040 * syncer process when the incore state is getting so far 3041 * ahead of the disk that the kernel memory pool is being 3042 * threatened with exhaustion. 3043 */ 3044 if (rushjob > 0) { 3045 rushjob -= 1; 3046 continue; 3047 } 3048 /* 3049 * Just sleep for a short period of time between 3050 * iterations when shutting down to allow some I/O 3051 * to happen. 3052 * 3053 * If it has taken us less than a second to process the 3054 * current work, then wait. Otherwise start right over 3055 * again. We can still lose time if any single round 3056 * takes more than two seconds, but it does not really 3057 * matter as we are just trying to generally pace the 3058 * filesystem activity. 3059 */ 3060 if (syncer_state != SYNCER_RUNNING || 3061 time_uptime == starttime) { 3062 thread_lock(td); 3063 sched_prio(td, PPAUSE); 3064 thread_unlock(td); 3065 } 3066 if (syncer_state != SYNCER_RUNNING) 3067 cv_timedwait(&sync_wakeup, &sync_mtx, 3068 hz / SYNCER_SHUTDOWN_SPEEDUP); 3069 else if (time_uptime == starttime) 3070 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 3071 } 3072 } 3073 3074 /* 3075 * Request the syncer daemon to speed up its work. 3076 * We never push it to speed up more than half of its 3077 * normal turn time, otherwise it could take over the cpu. 3078 */ 3079 int 3080 speedup_syncer(void) 3081 { 3082 int ret = 0; 3083 3084 mtx_lock(&sync_mtx); 3085 if (rushjob < syncdelay / 2) { 3086 rushjob += 1; 3087 stat_rush_requests += 1; 3088 ret = 1; 3089 } 3090 mtx_unlock(&sync_mtx); 3091 cv_broadcast(&sync_wakeup); 3092 return (ret); 3093 } 3094 3095 /* 3096 * Tell the syncer to speed up its work and run though its work 3097 * list several times, then tell it to shut down. 3098 */ 3099 static void 3100 syncer_shutdown(void *arg, int howto) 3101 { 3102 3103 if (howto & RB_NOSYNC) 3104 return; 3105 mtx_lock(&sync_mtx); 3106 syncer_state = SYNCER_SHUTTING_DOWN; 3107 rushjob = 0; 3108 mtx_unlock(&sync_mtx); 3109 cv_broadcast(&sync_wakeup); 3110 kproc_shutdown(arg, howto); 3111 } 3112 3113 void 3114 syncer_suspend(void) 3115 { 3116 3117 syncer_shutdown(updateproc, 0); 3118 } 3119 3120 void 3121 syncer_resume(void) 3122 { 3123 3124 mtx_lock(&sync_mtx); 3125 first_printf = 1; 3126 syncer_state = SYNCER_RUNNING; 3127 mtx_unlock(&sync_mtx); 3128 cv_broadcast(&sync_wakeup); 3129 kproc_resume(updateproc); 3130 } 3131 3132 /* 3133 * Move the buffer between the clean and dirty lists of its vnode. 3134 */ 3135 void 3136 reassignbuf(struct buf *bp) 3137 { 3138 struct vnode *vp; 3139 struct bufobj *bo; 3140 int delay; 3141 #ifdef INVARIANTS 3142 struct bufv *bv; 3143 #endif 3144 3145 vp = bp->b_vp; 3146 bo = bp->b_bufobj; 3147 3148 KASSERT((bp->b_flags & B_PAGING) == 0, 3149 ("%s: cannot reassign paging buffer %p", __func__, bp)); 3150 3151 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 3152 bp, bp->b_vp, bp->b_flags); 3153 3154 BO_LOCK(bo); 3155 buf_vlist_remove(bp); 3156 3157 /* 3158 * If dirty, put on list of dirty buffers; otherwise insert onto list 3159 * of clean buffers. 3160 */ 3161 if (bp->b_flags & B_DELWRI) { 3162 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 3163 switch (vp->v_type) { 3164 case VDIR: 3165 delay = dirdelay; 3166 break; 3167 case VCHR: 3168 delay = metadelay; 3169 break; 3170 default: 3171 delay = filedelay; 3172 } 3173 vn_syncer_add_to_worklist(bo, delay); 3174 } 3175 buf_vlist_add(bp, bo, BX_VNDIRTY); 3176 } else { 3177 buf_vlist_add(bp, bo, BX_VNCLEAN); 3178 3179 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 3180 mtx_lock(&sync_mtx); 3181 LIST_REMOVE(bo, bo_synclist); 3182 syncer_worklist_len--; 3183 mtx_unlock(&sync_mtx); 3184 bo->bo_flag &= ~BO_ONWORKLST; 3185 } 3186 } 3187 #ifdef INVARIANTS 3188 bv = &bo->bo_clean; 3189 bp = TAILQ_FIRST(&bv->bv_hd); 3190 KASSERT(bp == NULL || bp->b_bufobj == bo, 3191 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 3192 bp = TAILQ_LAST(&bv->bv_hd, buflists); 3193 KASSERT(bp == NULL || bp->b_bufobj == bo, 3194 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 3195 bv = &bo->bo_dirty; 3196 bp = TAILQ_FIRST(&bv->bv_hd); 3197 KASSERT(bp == NULL || bp->b_bufobj == bo, 3198 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 3199 bp = TAILQ_LAST(&bv->bv_hd, buflists); 3200 KASSERT(bp == NULL || bp->b_bufobj == bo, 3201 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 3202 #endif 3203 BO_UNLOCK(bo); 3204 } 3205 3206 static void 3207 v_init_counters(struct vnode *vp) 3208 { 3209 3210 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 3211 vp, ("%s called for an initialized vnode", __FUNCTION__)); 3212 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 3213 3214 refcount_init(&vp->v_holdcnt, 1); 3215 refcount_init(&vp->v_usecount, 1); 3216 } 3217 3218 /* 3219 * Get a usecount on a vnode. 3220 * 3221 * vget and vget_finish may fail to lock the vnode if they lose a race against 3222 * it being doomed. LK_RETRY can be passed in flags to lock it anyway. 3223 * 3224 * Consumers which don't guarantee liveness of the vnode can use SMR to 3225 * try to get a reference. Note this operation can fail since the vnode 3226 * may be awaiting getting freed by the time they get to it. 3227 */ 3228 enum vgetstate 3229 vget_prep_smr(struct vnode *vp) 3230 { 3231 enum vgetstate vs; 3232 3233 VFS_SMR_ASSERT_ENTERED(); 3234 3235 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3236 vs = VGET_USECOUNT; 3237 } else { 3238 if (vhold_smr(vp)) 3239 vs = VGET_HOLDCNT; 3240 else 3241 vs = VGET_NONE; 3242 } 3243 return (vs); 3244 } 3245 3246 enum vgetstate 3247 vget_prep(struct vnode *vp) 3248 { 3249 enum vgetstate vs; 3250 3251 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 3252 vs = VGET_USECOUNT; 3253 } else { 3254 vhold(vp); 3255 vs = VGET_HOLDCNT; 3256 } 3257 return (vs); 3258 } 3259 3260 void 3261 vget_abort(struct vnode *vp, enum vgetstate vs) 3262 { 3263 3264 switch (vs) { 3265 case VGET_USECOUNT: 3266 vrele(vp); 3267 break; 3268 case VGET_HOLDCNT: 3269 vdrop(vp); 3270 break; 3271 default: 3272 __assert_unreachable(); 3273 } 3274 } 3275 3276 int 3277 vget(struct vnode *vp, int flags) 3278 { 3279 enum vgetstate vs; 3280 3281 vs = vget_prep(vp); 3282 return (vget_finish(vp, flags, vs)); 3283 } 3284 3285 int 3286 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 3287 { 3288 int error; 3289 3290 if ((flags & LK_INTERLOCK) != 0) 3291 ASSERT_VI_LOCKED(vp, __func__); 3292 else 3293 ASSERT_VI_UNLOCKED(vp, __func__); 3294 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 3295 VNPASS(vp->v_holdcnt > 0, vp); 3296 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 3297 3298 error = vn_lock(vp, flags); 3299 if (__predict_false(error != 0)) { 3300 vget_abort(vp, vs); 3301 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 3302 vp); 3303 return (error); 3304 } 3305 3306 vget_finish_ref(vp, vs); 3307 return (0); 3308 } 3309 3310 void 3311 vget_finish_ref(struct vnode *vp, enum vgetstate vs) 3312 { 3313 int old; 3314 3315 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp); 3316 VNPASS(vp->v_holdcnt > 0, vp); 3317 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp); 3318 3319 if (vs == VGET_USECOUNT) 3320 return; 3321 3322 /* 3323 * We hold the vnode. If the usecount is 0 it will be utilized to keep 3324 * the vnode around. Otherwise someone else lended their hold count and 3325 * we have to drop ours. 3326 */ 3327 old = atomic_fetchadd_int(&vp->v_usecount, 1); 3328 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old)); 3329 if (old != 0) { 3330 #ifdef INVARIANTS 3331 old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 3332 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 3333 #else 3334 refcount_release(&vp->v_holdcnt); 3335 #endif 3336 } 3337 } 3338 3339 void 3340 vref(struct vnode *vp) 3341 { 3342 enum vgetstate vs; 3343 3344 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3345 vs = vget_prep(vp); 3346 vget_finish_ref(vp, vs); 3347 } 3348 3349 void 3350 vrefact(struct vnode *vp) 3351 { 3352 int old __diagused; 3353 3354 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3355 old = refcount_acquire(&vp->v_usecount); 3356 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 3357 } 3358 3359 void 3360 vlazy(struct vnode *vp) 3361 { 3362 struct mount *mp; 3363 3364 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 3365 3366 if ((vp->v_mflag & VMP_LAZYLIST) != 0) 3367 return; 3368 /* 3369 * We may get here for inactive routines after the vnode got doomed. 3370 */ 3371 if (VN_IS_DOOMED(vp)) 3372 return; 3373 mp = vp->v_mount; 3374 mtx_lock(&mp->mnt_listmtx); 3375 if ((vp->v_mflag & VMP_LAZYLIST) == 0) { 3376 vp->v_mflag |= VMP_LAZYLIST; 3377 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3378 mp->mnt_lazyvnodelistsize++; 3379 } 3380 mtx_unlock(&mp->mnt_listmtx); 3381 } 3382 3383 static void 3384 vunlazy(struct vnode *vp) 3385 { 3386 struct mount *mp; 3387 3388 ASSERT_VI_LOCKED(vp, __func__); 3389 VNPASS(!VN_IS_DOOMED(vp), vp); 3390 3391 mp = vp->v_mount; 3392 mtx_lock(&mp->mnt_listmtx); 3393 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3394 /* 3395 * Don't remove the vnode from the lazy list if another thread 3396 * has increased the hold count. It may have re-enqueued the 3397 * vnode to the lazy list and is now responsible for its 3398 * removal. 3399 */ 3400 if (vp->v_holdcnt == 0) { 3401 vp->v_mflag &= ~VMP_LAZYLIST; 3402 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3403 mp->mnt_lazyvnodelistsize--; 3404 } 3405 mtx_unlock(&mp->mnt_listmtx); 3406 } 3407 3408 /* 3409 * This routine is only meant to be called from vgonel prior to dooming 3410 * the vnode. 3411 */ 3412 static void 3413 vunlazy_gone(struct vnode *vp) 3414 { 3415 struct mount *mp; 3416 3417 ASSERT_VOP_ELOCKED(vp, __func__); 3418 ASSERT_VI_LOCKED(vp, __func__); 3419 VNPASS(!VN_IS_DOOMED(vp), vp); 3420 3421 if (vp->v_mflag & VMP_LAZYLIST) { 3422 mp = vp->v_mount; 3423 mtx_lock(&mp->mnt_listmtx); 3424 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 3425 vp->v_mflag &= ~VMP_LAZYLIST; 3426 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist); 3427 mp->mnt_lazyvnodelistsize--; 3428 mtx_unlock(&mp->mnt_listmtx); 3429 } 3430 } 3431 3432 static void 3433 vdefer_inactive(struct vnode *vp) 3434 { 3435 3436 ASSERT_VI_LOCKED(vp, __func__); 3437 VNPASS(vp->v_holdcnt > 0, vp); 3438 if (VN_IS_DOOMED(vp)) { 3439 vdropl(vp); 3440 return; 3441 } 3442 if (vp->v_iflag & VI_DEFINACT) { 3443 VNPASS(vp->v_holdcnt > 1, vp); 3444 vdropl(vp); 3445 return; 3446 } 3447 if (vp->v_usecount > 0) { 3448 vp->v_iflag &= ~VI_OWEINACT; 3449 vdropl(vp); 3450 return; 3451 } 3452 vlazy(vp); 3453 vp->v_iflag |= VI_DEFINACT; 3454 VI_UNLOCK(vp); 3455 atomic_add_long(&deferred_inact, 1); 3456 } 3457 3458 static void 3459 vdefer_inactive_unlocked(struct vnode *vp) 3460 { 3461 3462 VI_LOCK(vp); 3463 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3464 vdropl(vp); 3465 return; 3466 } 3467 vdefer_inactive(vp); 3468 } 3469 3470 enum vput_op { VRELE, VPUT, VUNREF }; 3471 3472 /* 3473 * Handle ->v_usecount transitioning to 0. 3474 * 3475 * By releasing the last usecount we take ownership of the hold count which 3476 * provides liveness of the vnode, meaning we have to vdrop. 3477 * 3478 * For all vnodes we may need to perform inactive processing. It requires an 3479 * exclusive lock on the vnode, while it is legal to call here with only a 3480 * shared lock (or no locks). If locking the vnode in an expected manner fails, 3481 * inactive processing gets deferred to the syncer. 3482 * 3483 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend 3484 * on the lock being held all the way until VOP_INACTIVE. This in particular 3485 * happens with UFS which adds half-constructed vnodes to the hash, where they 3486 * can be found by other code. 3487 */ 3488 static void 3489 vput_final(struct vnode *vp, enum vput_op func) 3490 { 3491 int error; 3492 bool want_unlock; 3493 3494 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3495 VNPASS(vp->v_holdcnt > 0, vp); 3496 3497 VI_LOCK(vp); 3498 3499 /* 3500 * By the time we got here someone else might have transitioned 3501 * the count back to > 0. 3502 */ 3503 if (vp->v_usecount > 0) 3504 goto out; 3505 3506 /* 3507 * If the vnode is doomed vgone already performed inactive processing 3508 * (if needed). 3509 */ 3510 if (VN_IS_DOOMED(vp)) 3511 goto out; 3512 3513 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0)) 3514 goto out; 3515 3516 if (vp->v_iflag & VI_DOINGINACT) 3517 goto out; 3518 3519 /* 3520 * Locking operations here will drop the interlock and possibly the 3521 * vnode lock, opening a window where the vnode can get doomed all the 3522 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to 3523 * perform inactive. 3524 */ 3525 vp->v_iflag |= VI_OWEINACT; 3526 want_unlock = false; 3527 error = 0; 3528 switch (func) { 3529 case VRELE: 3530 switch (VOP_ISLOCKED(vp)) { 3531 case LK_EXCLUSIVE: 3532 break; 3533 case LK_EXCLOTHER: 3534 case 0: 3535 want_unlock = true; 3536 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3537 VI_LOCK(vp); 3538 break; 3539 default: 3540 /* 3541 * The lock has at least one sharer, but we have no way 3542 * to conclude whether this is us. Play it safe and 3543 * defer processing. 3544 */ 3545 error = EAGAIN; 3546 break; 3547 } 3548 break; 3549 case VPUT: 3550 want_unlock = true; 3551 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3552 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 3553 LK_NOWAIT); 3554 VI_LOCK(vp); 3555 } 3556 break; 3557 case VUNREF: 3558 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3559 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3560 VI_LOCK(vp); 3561 } 3562 break; 3563 } 3564 if (error == 0) { 3565 if (func == VUNREF) { 3566 VNASSERT((vp->v_vflag & VV_UNREF) == 0, vp, 3567 ("recursive vunref")); 3568 vp->v_vflag |= VV_UNREF; 3569 } 3570 for (;;) { 3571 error = vinactive(vp); 3572 if (want_unlock) 3573 VOP_UNLOCK(vp); 3574 if (error != ERELOOKUP || !want_unlock) 3575 break; 3576 VOP_LOCK(vp, LK_EXCLUSIVE); 3577 } 3578 if (func == VUNREF) 3579 vp->v_vflag &= ~VV_UNREF; 3580 vdropl(vp); 3581 } else { 3582 vdefer_inactive(vp); 3583 } 3584 return; 3585 out: 3586 if (func == VPUT) 3587 VOP_UNLOCK(vp); 3588 vdropl(vp); 3589 } 3590 3591 /* 3592 * Decrement ->v_usecount for a vnode. 3593 * 3594 * Releasing the last use count requires additional processing, see vput_final 3595 * above for details. 3596 * 3597 * Comment above each variant denotes lock state on entry and exit. 3598 */ 3599 3600 /* 3601 * in: any 3602 * out: same as passed in 3603 */ 3604 void 3605 vrele(struct vnode *vp) 3606 { 3607 3608 ASSERT_VI_UNLOCKED(vp, __func__); 3609 if (!refcount_release(&vp->v_usecount)) 3610 return; 3611 vput_final(vp, VRELE); 3612 } 3613 3614 /* 3615 * in: locked 3616 * out: unlocked 3617 */ 3618 void 3619 vput(struct vnode *vp) 3620 { 3621 3622 ASSERT_VOP_LOCKED(vp, __func__); 3623 ASSERT_VI_UNLOCKED(vp, __func__); 3624 if (!refcount_release(&vp->v_usecount)) { 3625 VOP_UNLOCK(vp); 3626 return; 3627 } 3628 vput_final(vp, VPUT); 3629 } 3630 3631 /* 3632 * in: locked 3633 * out: locked 3634 */ 3635 void 3636 vunref(struct vnode *vp) 3637 { 3638 3639 ASSERT_VOP_LOCKED(vp, __func__); 3640 ASSERT_VI_UNLOCKED(vp, __func__); 3641 if (!refcount_release(&vp->v_usecount)) 3642 return; 3643 vput_final(vp, VUNREF); 3644 } 3645 3646 void 3647 vhold(struct vnode *vp) 3648 { 3649 int old; 3650 3651 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3652 old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3653 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3654 ("%s: wrong hold count %d", __func__, old)); 3655 if (old == 0) 3656 vfs_freevnodes_dec(); 3657 } 3658 3659 void 3660 vholdnz(struct vnode *vp) 3661 { 3662 3663 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3664 #ifdef INVARIANTS 3665 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3666 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp, 3667 ("%s: wrong hold count %d", __func__, old)); 3668 #else 3669 atomic_add_int(&vp->v_holdcnt, 1); 3670 #endif 3671 } 3672 3673 /* 3674 * Grab a hold count unless the vnode is freed. 3675 * 3676 * Only use this routine if vfs smr is the only protection you have against 3677 * freeing the vnode. 3678 * 3679 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag 3680 * is not set. After the flag is set the vnode becomes immutable to anyone but 3681 * the thread which managed to set the flag. 3682 * 3683 * It may be tempting to replace the loop with: 3684 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3685 * if (count & VHOLD_NO_SMR) { 3686 * backpedal and error out; 3687 * } 3688 * 3689 * However, while this is more performant, it hinders debugging by eliminating 3690 * the previously mentioned invariant. 3691 */ 3692 bool 3693 vhold_smr(struct vnode *vp) 3694 { 3695 int count; 3696 3697 VFS_SMR_ASSERT_ENTERED(); 3698 3699 count = atomic_load_int(&vp->v_holdcnt); 3700 for (;;) { 3701 if (count & VHOLD_NO_SMR) { 3702 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3703 ("non-zero hold count with flags %d\n", count)); 3704 return (false); 3705 } 3706 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3707 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) { 3708 if (count == 0) 3709 vfs_freevnodes_dec(); 3710 return (true); 3711 } 3712 } 3713 } 3714 3715 /* 3716 * Hold a free vnode for recycling. 3717 * 3718 * Note: vnode_init references this comment. 3719 * 3720 * Attempts to recycle only need the global vnode list lock and have no use for 3721 * SMR. 3722 * 3723 * However, vnodes get inserted into the global list before they get fully 3724 * initialized and stay there until UMA decides to free the memory. This in 3725 * particular means the target can be found before it becomes usable and after 3726 * it becomes recycled. Picking up such vnodes is guarded with v_holdcnt set to 3727 * VHOLD_NO_SMR. 3728 * 3729 * Note: the vnode may gain more references after we transition the count 0->1. 3730 */ 3731 static bool 3732 vhold_recycle_free(struct vnode *vp) 3733 { 3734 int count; 3735 3736 mtx_assert(&vnode_list_mtx, MA_OWNED); 3737 3738 count = atomic_load_int(&vp->v_holdcnt); 3739 for (;;) { 3740 if (count & VHOLD_NO_SMR) { 3741 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp, 3742 ("non-zero hold count with flags %d\n", count)); 3743 return (false); 3744 } 3745 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count)); 3746 if (count > 0) { 3747 return (false); 3748 } 3749 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) { 3750 vfs_freevnodes_dec(); 3751 return (true); 3752 } 3753 } 3754 } 3755 3756 static void __noinline 3757 vdbatch_process(struct vdbatch *vd) 3758 { 3759 struct vnode *vp; 3760 int i; 3761 3762 mtx_assert(&vd->lock, MA_OWNED); 3763 MPASS(curthread->td_pinned > 0); 3764 MPASS(vd->index == VDBATCH_SIZE); 3765 3766 /* 3767 * Attempt to requeue the passed batch, but give up easily. 3768 * 3769 * Despite batching the mechanism is prone to transient *significant* 3770 * lock contention, where vnode_list_mtx becomes the primary bottleneck 3771 * if multiple CPUs get here (one real-world example is highly parallel 3772 * do-nothing make , which will stat *tons* of vnodes). Since it is 3773 * quasi-LRU (read: not that great even if fully honoured) just dodge 3774 * the problem. Parties which don't like it are welcome to implement 3775 * something better. 3776 */ 3777 critical_enter(); 3778 if (mtx_trylock(&vnode_list_mtx)) { 3779 for (i = 0; i < VDBATCH_SIZE; i++) { 3780 vp = vd->tab[i]; 3781 vd->tab[i] = NULL; 3782 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist); 3783 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist); 3784 MPASS(vp->v_dbatchcpu != NOCPU); 3785 vp->v_dbatchcpu = NOCPU; 3786 } 3787 mtx_unlock(&vnode_list_mtx); 3788 } else { 3789 counter_u64_add(vnode_skipped_requeues, 1); 3790 3791 for (i = 0; i < VDBATCH_SIZE; i++) { 3792 vp = vd->tab[i]; 3793 vd->tab[i] = NULL; 3794 MPASS(vp->v_dbatchcpu != NOCPU); 3795 vp->v_dbatchcpu = NOCPU; 3796 } 3797 } 3798 vd->index = 0; 3799 critical_exit(); 3800 } 3801 3802 static void 3803 vdbatch_enqueue(struct vnode *vp) 3804 { 3805 struct vdbatch *vd; 3806 3807 ASSERT_VI_LOCKED(vp, __func__); 3808 VNPASS(!VN_IS_DOOMED(vp), vp); 3809 3810 if (vp->v_dbatchcpu != NOCPU) { 3811 VI_UNLOCK(vp); 3812 return; 3813 } 3814 3815 sched_pin(); 3816 vd = DPCPU_PTR(vd); 3817 mtx_lock(&vd->lock); 3818 MPASS(vd->index < VDBATCH_SIZE); 3819 MPASS(vd->tab[vd->index] == NULL); 3820 /* 3821 * A hack: we depend on being pinned so that we know what to put in 3822 * ->v_dbatchcpu. 3823 */ 3824 vp->v_dbatchcpu = curcpu; 3825 vd->tab[vd->index] = vp; 3826 vd->index++; 3827 VI_UNLOCK(vp); 3828 if (vd->index == VDBATCH_SIZE) 3829 vdbatch_process(vd); 3830 mtx_unlock(&vd->lock); 3831 sched_unpin(); 3832 } 3833 3834 /* 3835 * This routine must only be called for vnodes which are about to be 3836 * deallocated. Supporting dequeue for arbitrary vndoes would require 3837 * validating that the locked batch matches. 3838 */ 3839 static void 3840 vdbatch_dequeue(struct vnode *vp) 3841 { 3842 struct vdbatch *vd; 3843 int i; 3844 short cpu; 3845 3846 VNPASS(vp->v_type == VBAD || vp->v_type == VNON, vp); 3847 3848 cpu = vp->v_dbatchcpu; 3849 if (cpu == NOCPU) 3850 return; 3851 3852 vd = DPCPU_ID_PTR(cpu, vd); 3853 mtx_lock(&vd->lock); 3854 for (i = 0; i < vd->index; i++) { 3855 if (vd->tab[i] != vp) 3856 continue; 3857 vp->v_dbatchcpu = NOCPU; 3858 vd->index--; 3859 vd->tab[i] = vd->tab[vd->index]; 3860 vd->tab[vd->index] = NULL; 3861 break; 3862 } 3863 mtx_unlock(&vd->lock); 3864 /* 3865 * Either we dequeued the vnode above or the target CPU beat us to it. 3866 */ 3867 MPASS(vp->v_dbatchcpu == NOCPU); 3868 } 3869 3870 /* 3871 * Drop the hold count of the vnode. 3872 * 3873 * It will only get freed if this is the last hold *and* it has been vgone'd. 3874 * 3875 * Because the vnode vm object keeps a hold reference on the vnode if 3876 * there is at least one resident non-cached page, the vnode cannot 3877 * leave the active list without the page cleanup done. 3878 */ 3879 static void __noinline 3880 vdropl_final(struct vnode *vp) 3881 { 3882 3883 ASSERT_VI_LOCKED(vp, __func__); 3884 VNPASS(VN_IS_DOOMED(vp), vp); 3885 /* 3886 * Set the VHOLD_NO_SMR flag. 3887 * 3888 * We may be racing against vhold_smr. If they win we can just pretend 3889 * we never got this far, they will vdrop later. 3890 */ 3891 if (__predict_false(!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR))) { 3892 vfs_freevnodes_inc(); 3893 VI_UNLOCK(vp); 3894 /* 3895 * We lost the aforementioned race. Any subsequent access is 3896 * invalid as they might have managed to vdropl on their own. 3897 */ 3898 return; 3899 } 3900 /* 3901 * Don't bump freevnodes as this one is going away. 3902 */ 3903 freevnode(vp); 3904 } 3905 3906 void 3907 vdrop(struct vnode *vp) 3908 { 3909 3910 ASSERT_VI_UNLOCKED(vp, __func__); 3911 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3912 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3913 return; 3914 VI_LOCK(vp); 3915 vdropl(vp); 3916 } 3917 3918 static void __always_inline 3919 vdropl_impl(struct vnode *vp, bool enqueue) 3920 { 3921 3922 ASSERT_VI_LOCKED(vp, __func__); 3923 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3924 if (!refcount_release(&vp->v_holdcnt)) { 3925 VI_UNLOCK(vp); 3926 return; 3927 } 3928 VNPASS((vp->v_iflag & VI_OWEINACT) == 0, vp); 3929 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp); 3930 if (VN_IS_DOOMED(vp)) { 3931 vdropl_final(vp); 3932 return; 3933 } 3934 3935 vfs_freevnodes_inc(); 3936 if (vp->v_mflag & VMP_LAZYLIST) { 3937 vunlazy(vp); 3938 } 3939 3940 if (!enqueue) { 3941 VI_UNLOCK(vp); 3942 return; 3943 } 3944 3945 /* 3946 * Also unlocks the interlock. We can't assert on it as we 3947 * released our hold and by now the vnode might have been 3948 * freed. 3949 */ 3950 vdbatch_enqueue(vp); 3951 } 3952 3953 void 3954 vdropl(struct vnode *vp) 3955 { 3956 3957 vdropl_impl(vp, true); 3958 } 3959 3960 /* 3961 * vdrop a vnode when recycling 3962 * 3963 * This is a special case routine only to be used when recycling, differs from 3964 * regular vdrop by not requeieing the vnode on LRU. 3965 * 3966 * Consider a case where vtryrecycle continuously fails with all vnodes (due to 3967 * e.g., frozen writes on the filesystem), filling the batch and causing it to 3968 * be requeued. Then vnlru will end up revisiting the same vnodes. This is a 3969 * loop which can last for as long as writes are frozen. 3970 */ 3971 static void 3972 vdropl_recycle(struct vnode *vp) 3973 { 3974 3975 vdropl_impl(vp, false); 3976 } 3977 3978 static void 3979 vdrop_recycle(struct vnode *vp) 3980 { 3981 3982 VI_LOCK(vp); 3983 vdropl_recycle(vp); 3984 } 3985 3986 /* 3987 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3988 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3989 */ 3990 static int 3991 vinactivef(struct vnode *vp) 3992 { 3993 int error; 3994 3995 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3996 ASSERT_VI_LOCKED(vp, "vinactive"); 3997 VNPASS((vp->v_iflag & VI_DOINGINACT) == 0, vp); 3998 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3999 vp->v_iflag |= VI_DOINGINACT; 4000 vp->v_iflag &= ~VI_OWEINACT; 4001 VI_UNLOCK(vp); 4002 4003 /* 4004 * Before moving off the active list, we must be sure that any 4005 * modified pages are converted into the vnode's dirty 4006 * buffers, since these will no longer be checked once the 4007 * vnode is on the inactive list. 4008 * 4009 * The write-out of the dirty pages is asynchronous. At the 4010 * point that VOP_INACTIVE() is called, there could still be 4011 * pending I/O and dirty pages in the object. 4012 */ 4013 if ((vp->v_vflag & VV_NOSYNC) == 0) 4014 vnode_pager_clean_async(vp); 4015 4016 error = VOP_INACTIVE(vp); 4017 VI_LOCK(vp); 4018 VNPASS(vp->v_iflag & VI_DOINGINACT, vp); 4019 vp->v_iflag &= ~VI_DOINGINACT; 4020 return (error); 4021 } 4022 4023 int 4024 vinactive(struct vnode *vp) 4025 { 4026 4027 ASSERT_VOP_ELOCKED(vp, "vinactive"); 4028 ASSERT_VI_LOCKED(vp, "vinactive"); 4029 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 4030 4031 if ((vp->v_iflag & VI_OWEINACT) == 0) 4032 return (0); 4033 if (vp->v_iflag & VI_DOINGINACT) 4034 return (0); 4035 if (vp->v_usecount > 0) { 4036 vp->v_iflag &= ~VI_OWEINACT; 4037 return (0); 4038 } 4039 return (vinactivef(vp)); 4040 } 4041 4042 /* 4043 * Remove any vnodes in the vnode table belonging to mount point mp. 4044 * 4045 * If FORCECLOSE is not specified, there should not be any active ones, 4046 * return error if any are found (nb: this is a user error, not a 4047 * system error). If FORCECLOSE is specified, detach any active vnodes 4048 * that are found. 4049 * 4050 * If WRITECLOSE is set, only flush out regular file vnodes open for 4051 * writing. 4052 * 4053 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 4054 * 4055 * `rootrefs' specifies the base reference count for the root vnode 4056 * of this filesystem. The root vnode is considered busy if its 4057 * v_usecount exceeds this value. On a successful return, vflush(, td) 4058 * will call vrele() on the root vnode exactly rootrefs times. 4059 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 4060 * be zero. 4061 */ 4062 #ifdef DIAGNOSTIC 4063 static int busyprt = 0; /* print out busy vnodes */ 4064 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 4065 #endif 4066 4067 int 4068 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 4069 { 4070 struct vnode *vp, *mvp, *rootvp = NULL; 4071 struct vattr vattr; 4072 int busy = 0, error; 4073 4074 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 4075 rootrefs, flags); 4076 if (rootrefs > 0) { 4077 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 4078 ("vflush: bad args")); 4079 /* 4080 * Get the filesystem root vnode. We can vput() it 4081 * immediately, since with rootrefs > 0, it won't go away. 4082 */ 4083 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 4084 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 4085 __func__, error); 4086 return (error); 4087 } 4088 vput(rootvp); 4089 } 4090 loop: 4091 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 4092 vholdl(vp); 4093 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 4094 if (error) { 4095 vdrop(vp); 4096 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 4097 goto loop; 4098 } 4099 /* 4100 * Skip over a vnodes marked VV_SYSTEM. 4101 */ 4102 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 4103 VOP_UNLOCK(vp); 4104 vdrop(vp); 4105 continue; 4106 } 4107 /* 4108 * If WRITECLOSE is set, flush out unlinked but still open 4109 * files (even if open only for reading) and regular file 4110 * vnodes open for writing. 4111 */ 4112 if (flags & WRITECLOSE) { 4113 vnode_pager_clean_async(vp); 4114 do { 4115 error = VOP_FSYNC(vp, MNT_WAIT, td); 4116 } while (error == ERELOOKUP); 4117 if (error != 0) { 4118 VOP_UNLOCK(vp); 4119 vdrop(vp); 4120 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 4121 return (error); 4122 } 4123 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 4124 VI_LOCK(vp); 4125 4126 if ((vp->v_type == VNON || 4127 (error == 0 && vattr.va_nlink > 0)) && 4128 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 4129 VOP_UNLOCK(vp); 4130 vdropl(vp); 4131 continue; 4132 } 4133 } else 4134 VI_LOCK(vp); 4135 /* 4136 * With v_usecount == 0, all we need to do is clear out the 4137 * vnode data structures and we are done. 4138 * 4139 * If FORCECLOSE is set, forcibly close the vnode. 4140 */ 4141 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 4142 vgonel(vp); 4143 } else { 4144 busy++; 4145 #ifdef DIAGNOSTIC 4146 if (busyprt) 4147 vn_printf(vp, "vflush: busy vnode "); 4148 #endif 4149 } 4150 VOP_UNLOCK(vp); 4151 vdropl(vp); 4152 } 4153 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 4154 /* 4155 * If just the root vnode is busy, and if its refcount 4156 * is equal to `rootrefs', then go ahead and kill it. 4157 */ 4158 VI_LOCK(rootvp); 4159 KASSERT(busy > 0, ("vflush: not busy")); 4160 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 4161 ("vflush: usecount %d < rootrefs %d", 4162 rootvp->v_usecount, rootrefs)); 4163 if (busy == 1 && rootvp->v_usecount == rootrefs) { 4164 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 4165 vgone(rootvp); 4166 VOP_UNLOCK(rootvp); 4167 busy = 0; 4168 } else 4169 VI_UNLOCK(rootvp); 4170 } 4171 if (busy) { 4172 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 4173 busy); 4174 return (EBUSY); 4175 } 4176 for (; rootrefs > 0; rootrefs--) 4177 vrele(rootvp); 4178 return (0); 4179 } 4180 4181 /* 4182 * Recycle an unused vnode. 4183 */ 4184 int 4185 vrecycle(struct vnode *vp) 4186 { 4187 int recycled; 4188 4189 VI_LOCK(vp); 4190 recycled = vrecyclel(vp); 4191 VI_UNLOCK(vp); 4192 return (recycled); 4193 } 4194 4195 /* 4196 * vrecycle, with the vp interlock held. 4197 */ 4198 int 4199 vrecyclel(struct vnode *vp) 4200 { 4201 int recycled; 4202 4203 ASSERT_VOP_ELOCKED(vp, __func__); 4204 ASSERT_VI_LOCKED(vp, __func__); 4205 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 4206 recycled = 0; 4207 if (vp->v_usecount == 0) { 4208 recycled = 1; 4209 vgonel(vp); 4210 } 4211 return (recycled); 4212 } 4213 4214 /* 4215 * Eliminate all activity associated with a vnode 4216 * in preparation for reuse. 4217 */ 4218 void 4219 vgone(struct vnode *vp) 4220 { 4221 VI_LOCK(vp); 4222 vgonel(vp); 4223 VI_UNLOCK(vp); 4224 } 4225 4226 /* 4227 * Notify upper mounts about reclaimed or unlinked vnode. 4228 */ 4229 void 4230 vfs_notify_upper(struct vnode *vp, enum vfs_notify_upper_type event) 4231 { 4232 struct mount *mp; 4233 struct mount_upper_node *ump; 4234 4235 mp = atomic_load_ptr(&vp->v_mount); 4236 if (mp == NULL) 4237 return; 4238 if (TAILQ_EMPTY(&mp->mnt_notify)) 4239 return; 4240 4241 MNT_ILOCK(mp); 4242 mp->mnt_upper_pending++; 4243 KASSERT(mp->mnt_upper_pending > 0, 4244 ("%s: mnt_upper_pending %d", __func__, mp->mnt_upper_pending)); 4245 TAILQ_FOREACH(ump, &mp->mnt_notify, mnt_upper_link) { 4246 MNT_IUNLOCK(mp); 4247 switch (event) { 4248 case VFS_NOTIFY_UPPER_RECLAIM: 4249 VFS_RECLAIM_LOWERVP(ump->mp, vp); 4250 break; 4251 case VFS_NOTIFY_UPPER_UNLINK: 4252 VFS_UNLINK_LOWERVP(ump->mp, vp); 4253 break; 4254 } 4255 MNT_ILOCK(mp); 4256 } 4257 mp->mnt_upper_pending--; 4258 if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 && 4259 mp->mnt_upper_pending == 0) { 4260 mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER; 4261 wakeup(&mp->mnt_uppers); 4262 } 4263 MNT_IUNLOCK(mp); 4264 } 4265 4266 /* 4267 * vgone, with the vp interlock held. 4268 */ 4269 static void 4270 vgonel(struct vnode *vp) 4271 { 4272 struct thread *td; 4273 struct mount *mp; 4274 vm_object_t object; 4275 bool active, doinginact, oweinact; 4276 4277 ASSERT_VOP_ELOCKED(vp, "vgonel"); 4278 ASSERT_VI_LOCKED(vp, "vgonel"); 4279 VNASSERT(vp->v_holdcnt, vp, 4280 ("vgonel: vp %p has no reference.", vp)); 4281 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 4282 td = curthread; 4283 4284 /* 4285 * Don't vgonel if we're already doomed. 4286 */ 4287 if (VN_IS_DOOMED(vp)) { 4288 VNPASS(vn_get_state(vp) == VSTATE_DESTROYING || \ 4289 vn_get_state(vp) == VSTATE_DEAD, vp); 4290 return; 4291 } 4292 /* 4293 * Paired with freevnode. 4294 */ 4295 vn_seqc_write_begin_locked(vp); 4296 vunlazy_gone(vp); 4297 vn_irflag_set_locked(vp, VIRF_DOOMED); 4298 vn_set_state(vp, VSTATE_DESTROYING); 4299 4300 /* 4301 * Check to see if the vnode is in use. If so, we have to 4302 * call VOP_CLOSE() and VOP_INACTIVE(). 4303 * 4304 * It could be that VOP_INACTIVE() requested reclamation, in 4305 * which case we should avoid recursion, so check 4306 * VI_DOINGINACT. This is not precise but good enough. 4307 */ 4308 active = vp->v_usecount > 0; 4309 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 4310 doinginact = (vp->v_iflag & VI_DOINGINACT) != 0; 4311 4312 /* 4313 * If we need to do inactive VI_OWEINACT will be set. 4314 */ 4315 if (vp->v_iflag & VI_DEFINACT) { 4316 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count")); 4317 vp->v_iflag &= ~VI_DEFINACT; 4318 vdropl(vp); 4319 } else { 4320 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count")); 4321 VI_UNLOCK(vp); 4322 } 4323 cache_purge_vgone(vp); 4324 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 4325 4326 /* 4327 * If purging an active vnode, it must be closed and 4328 * deactivated before being reclaimed. 4329 */ 4330 if (active) 4331 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 4332 if (!doinginact) { 4333 do { 4334 if (oweinact || active) { 4335 VI_LOCK(vp); 4336 vinactivef(vp); 4337 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 4338 VI_UNLOCK(vp); 4339 } 4340 } while (oweinact); 4341 } 4342 if (vp->v_type == VSOCK) 4343 vfs_unp_reclaim(vp); 4344 4345 /* 4346 * Clean out any buffers associated with the vnode. 4347 * If the flush fails, just toss the buffers. 4348 */ 4349 mp = NULL; 4350 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 4351 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 4352 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 4353 while (vinvalbuf(vp, 0, 0, 0) != 0) 4354 ; 4355 } 4356 4357 BO_LOCK(&vp->v_bufobj); 4358 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 4359 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 4360 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 4361 vp->v_bufobj.bo_clean.bv_cnt == 0, 4362 ("vp %p bufobj not invalidated", vp)); 4363 4364 /* 4365 * For VMIO bufobj, BO_DEAD is set later, or in 4366 * vm_object_terminate() after the object's page queue is 4367 * flushed. 4368 */ 4369 object = vp->v_bufobj.bo_object; 4370 if (object == NULL) 4371 vp->v_bufobj.bo_flag |= BO_DEAD; 4372 BO_UNLOCK(&vp->v_bufobj); 4373 4374 /* 4375 * Handle the VM part. Tmpfs handles v_object on its own (the 4376 * OBJT_VNODE check). Nullfs or other bypassing filesystems 4377 * should not touch the object borrowed from the lower vnode 4378 * (the handle check). 4379 */ 4380 if (object != NULL && object->type == OBJT_VNODE && 4381 object->handle == vp) 4382 vnode_destroy_vobject(vp); 4383 4384 /* 4385 * Reclaim the vnode. 4386 */ 4387 if (VOP_RECLAIM(vp)) 4388 panic("vgone: cannot reclaim"); 4389 if (mp != NULL) 4390 vn_finished_secondary_write(mp); 4391 VNASSERT(vp->v_object == NULL, vp, 4392 ("vop_reclaim left v_object vp=%p", vp)); 4393 /* 4394 * Clear the advisory locks and wake up waiting threads. 4395 */ 4396 if (vp->v_lockf != NULL) { 4397 (void)VOP_ADVLOCKPURGE(vp); 4398 vp->v_lockf = NULL; 4399 } 4400 /* 4401 * Delete from old mount point vnode list. 4402 */ 4403 if (vp->v_mount == NULL) { 4404 VI_LOCK(vp); 4405 } else { 4406 delmntque(vp); 4407 ASSERT_VI_LOCKED(vp, "vgonel 2"); 4408 } 4409 /* 4410 * Done with purge, reset to the standard lock and invalidate 4411 * the vnode. 4412 */ 4413 vp->v_vnlock = &vp->v_lock; 4414 vp->v_op = &dead_vnodeops; 4415 vp->v_type = VBAD; 4416 vn_set_state(vp, VSTATE_DEAD); 4417 } 4418 4419 /* 4420 * Print out a description of a vnode. 4421 */ 4422 static const char *const vtypename[] = { 4423 [VNON] = "VNON", 4424 [VREG] = "VREG", 4425 [VDIR] = "VDIR", 4426 [VBLK] = "VBLK", 4427 [VCHR] = "VCHR", 4428 [VLNK] = "VLNK", 4429 [VSOCK] = "VSOCK", 4430 [VFIFO] = "VFIFO", 4431 [VBAD] = "VBAD", 4432 [VMARKER] = "VMARKER", 4433 }; 4434 _Static_assert(nitems(vtypename) == VLASTTYPE + 1, 4435 "vnode type name not added to vtypename"); 4436 4437 static const char *const vstatename[] = { 4438 [VSTATE_UNINITIALIZED] = "VSTATE_UNINITIALIZED", 4439 [VSTATE_CONSTRUCTED] = "VSTATE_CONSTRUCTED", 4440 [VSTATE_DESTROYING] = "VSTATE_DESTROYING", 4441 [VSTATE_DEAD] = "VSTATE_DEAD", 4442 }; 4443 _Static_assert(nitems(vstatename) == VLASTSTATE + 1, 4444 "vnode state name not added to vstatename"); 4445 4446 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0, 4447 "new hold count flag not added to vn_printf"); 4448 4449 void 4450 vn_printf(struct vnode *vp, const char *fmt, ...) 4451 { 4452 va_list ap; 4453 char buf[256], buf2[16]; 4454 u_long flags; 4455 u_int holdcnt; 4456 short irflag; 4457 4458 va_start(ap, fmt); 4459 vprintf(fmt, ap); 4460 va_end(ap); 4461 printf("%p: ", (void *)vp); 4462 printf("type %s state %s op %p\n", vtypename[vp->v_type], 4463 vstatename[vp->v_state], vp->v_op); 4464 holdcnt = atomic_load_int(&vp->v_holdcnt); 4465 printf(" usecount %d, writecount %d, refcount %d seqc users %d", 4466 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS, 4467 vp->v_seqc_users); 4468 switch (vp->v_type) { 4469 case VDIR: 4470 printf(" mountedhere %p\n", vp->v_mountedhere); 4471 break; 4472 case VCHR: 4473 printf(" rdev %p\n", vp->v_rdev); 4474 break; 4475 case VSOCK: 4476 printf(" socket %p\n", vp->v_unpcb); 4477 break; 4478 case VFIFO: 4479 printf(" fifoinfo %p\n", vp->v_fifoinfo); 4480 break; 4481 default: 4482 printf("\n"); 4483 break; 4484 } 4485 buf[0] = '\0'; 4486 buf[1] = '\0'; 4487 if (holdcnt & VHOLD_NO_SMR) 4488 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf)); 4489 printf(" hold count flags (%s)\n", buf + 1); 4490 4491 buf[0] = '\0'; 4492 buf[1] = '\0'; 4493 irflag = vn_irflag_read(vp); 4494 if (irflag & VIRF_DOOMED) 4495 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 4496 if (irflag & VIRF_PGREAD) 4497 strlcat(buf, "|VIRF_PGREAD", sizeof(buf)); 4498 if (irflag & VIRF_MOUNTPOINT) 4499 strlcat(buf, "|VIRF_MOUNTPOINT", sizeof(buf)); 4500 if (irflag & VIRF_TEXT_REF) 4501 strlcat(buf, "|VIRF_TEXT_REF", sizeof(buf)); 4502 flags = irflag & ~(VIRF_DOOMED | VIRF_PGREAD | VIRF_MOUNTPOINT | VIRF_TEXT_REF); 4503 if (flags != 0) { 4504 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 4505 strlcat(buf, buf2, sizeof(buf)); 4506 } 4507 if (vp->v_vflag & VV_ROOT) 4508 strlcat(buf, "|VV_ROOT", sizeof(buf)); 4509 if (vp->v_vflag & VV_ISTTY) 4510 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 4511 if (vp->v_vflag & VV_NOSYNC) 4512 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 4513 if (vp->v_vflag & VV_ETERNALDEV) 4514 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 4515 if (vp->v_vflag & VV_CACHEDLABEL) 4516 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 4517 if (vp->v_vflag & VV_VMSIZEVNLOCK) 4518 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 4519 if (vp->v_vflag & VV_COPYONWRITE) 4520 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 4521 if (vp->v_vflag & VV_SYSTEM) 4522 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 4523 if (vp->v_vflag & VV_PROCDEP) 4524 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 4525 if (vp->v_vflag & VV_DELETED) 4526 strlcat(buf, "|VV_DELETED", sizeof(buf)); 4527 if (vp->v_vflag & VV_MD) 4528 strlcat(buf, "|VV_MD", sizeof(buf)); 4529 if (vp->v_vflag & VV_FORCEINSMQ) 4530 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 4531 if (vp->v_vflag & VV_READLINK) 4532 strlcat(buf, "|VV_READLINK", sizeof(buf)); 4533 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 4534 VV_CACHEDLABEL | VV_VMSIZEVNLOCK | VV_COPYONWRITE | VV_SYSTEM | 4535 VV_PROCDEP | VV_DELETED | VV_MD | VV_FORCEINSMQ | VV_READLINK); 4536 if (flags != 0) { 4537 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 4538 strlcat(buf, buf2, sizeof(buf)); 4539 } 4540 if (vp->v_iflag & VI_MOUNT) 4541 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 4542 if (vp->v_iflag & VI_DOINGINACT) 4543 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 4544 if (vp->v_iflag & VI_OWEINACT) 4545 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 4546 if (vp->v_iflag & VI_DEFINACT) 4547 strlcat(buf, "|VI_DEFINACT", sizeof(buf)); 4548 if (vp->v_iflag & VI_FOPENING) 4549 strlcat(buf, "|VI_FOPENING", sizeof(buf)); 4550 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOINGINACT | 4551 VI_OWEINACT | VI_DEFINACT | VI_FOPENING); 4552 if (flags != 0) { 4553 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 4554 strlcat(buf, buf2, sizeof(buf)); 4555 } 4556 if (vp->v_mflag & VMP_LAZYLIST) 4557 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf)); 4558 flags = vp->v_mflag & ~(VMP_LAZYLIST); 4559 if (flags != 0) { 4560 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 4561 strlcat(buf, buf2, sizeof(buf)); 4562 } 4563 printf(" flags (%s)", buf + 1); 4564 if (mtx_owned(VI_MTX(vp))) 4565 printf(" VI_LOCKed"); 4566 printf("\n"); 4567 if (vp->v_object != NULL) 4568 printf(" v_object %p ref %d pages %d " 4569 "cleanbuf %d dirtybuf %d\n", 4570 vp->v_object, vp->v_object->ref_count, 4571 vp->v_object->resident_page_count, 4572 vp->v_bufobj.bo_clean.bv_cnt, 4573 vp->v_bufobj.bo_dirty.bv_cnt); 4574 printf(" "); 4575 lockmgr_printinfo(vp->v_vnlock); 4576 if (vp->v_data != NULL) 4577 VOP_PRINT(vp); 4578 } 4579 4580 #ifdef DDB 4581 /* 4582 * List all of the locked vnodes in the system. 4583 * Called when debugging the kernel. 4584 */ 4585 DB_SHOW_COMMAND_FLAGS(lockedvnods, lockedvnodes, DB_CMD_MEMSAFE) 4586 { 4587 struct mount *mp; 4588 struct vnode *vp; 4589 4590 /* 4591 * Note: because this is DDB, we can't obey the locking semantics 4592 * for these structures, which means we could catch an inconsistent 4593 * state and dereference a nasty pointer. Not much to be done 4594 * about that. 4595 */ 4596 db_printf("Locked vnodes\n"); 4597 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4598 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4599 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 4600 vn_printf(vp, "vnode "); 4601 } 4602 } 4603 } 4604 4605 /* 4606 * Show details about the given vnode. 4607 */ 4608 DB_SHOW_COMMAND(vnode, db_show_vnode) 4609 { 4610 struct vnode *vp; 4611 4612 if (!have_addr) 4613 return; 4614 vp = (struct vnode *)addr; 4615 vn_printf(vp, "vnode "); 4616 } 4617 4618 /* 4619 * Show details about the given mount point. 4620 */ 4621 DB_SHOW_COMMAND(mount, db_show_mount) 4622 { 4623 struct mount *mp; 4624 struct vfsopt *opt; 4625 struct statfs *sp; 4626 struct vnode *vp; 4627 char buf[512]; 4628 uint64_t mflags; 4629 u_int flags; 4630 4631 if (!have_addr) { 4632 /* No address given, print short info about all mount points. */ 4633 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4634 db_printf("%p %s on %s (%s)\n", mp, 4635 mp->mnt_stat.f_mntfromname, 4636 mp->mnt_stat.f_mntonname, 4637 mp->mnt_stat.f_fstypename); 4638 if (db_pager_quit) 4639 break; 4640 } 4641 db_printf("\nMore info: show mount <addr>\n"); 4642 return; 4643 } 4644 4645 mp = (struct mount *)addr; 4646 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 4647 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 4648 4649 buf[0] = '\0'; 4650 mflags = mp->mnt_flag; 4651 #define MNT_FLAG(flag) do { \ 4652 if (mflags & (flag)) { \ 4653 if (buf[0] != '\0') \ 4654 strlcat(buf, ", ", sizeof(buf)); \ 4655 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 4656 mflags &= ~(flag); \ 4657 } \ 4658 } while (0) 4659 MNT_FLAG(MNT_RDONLY); 4660 MNT_FLAG(MNT_SYNCHRONOUS); 4661 MNT_FLAG(MNT_NOEXEC); 4662 MNT_FLAG(MNT_NOSUID); 4663 MNT_FLAG(MNT_NFS4ACLS); 4664 MNT_FLAG(MNT_UNION); 4665 MNT_FLAG(MNT_ASYNC); 4666 MNT_FLAG(MNT_SUIDDIR); 4667 MNT_FLAG(MNT_SOFTDEP); 4668 MNT_FLAG(MNT_NOSYMFOLLOW); 4669 MNT_FLAG(MNT_GJOURNAL); 4670 MNT_FLAG(MNT_MULTILABEL); 4671 MNT_FLAG(MNT_ACLS); 4672 MNT_FLAG(MNT_NOATIME); 4673 MNT_FLAG(MNT_NOCLUSTERR); 4674 MNT_FLAG(MNT_NOCLUSTERW); 4675 MNT_FLAG(MNT_SUJ); 4676 MNT_FLAG(MNT_EXRDONLY); 4677 MNT_FLAG(MNT_EXPORTED); 4678 MNT_FLAG(MNT_DEFEXPORTED); 4679 MNT_FLAG(MNT_EXPORTANON); 4680 MNT_FLAG(MNT_EXKERB); 4681 MNT_FLAG(MNT_EXPUBLIC); 4682 MNT_FLAG(MNT_LOCAL); 4683 MNT_FLAG(MNT_QUOTA); 4684 MNT_FLAG(MNT_ROOTFS); 4685 MNT_FLAG(MNT_USER); 4686 MNT_FLAG(MNT_IGNORE); 4687 MNT_FLAG(MNT_UPDATE); 4688 MNT_FLAG(MNT_DELEXPORT); 4689 MNT_FLAG(MNT_RELOAD); 4690 MNT_FLAG(MNT_FORCE); 4691 MNT_FLAG(MNT_SNAPSHOT); 4692 MNT_FLAG(MNT_BYFSID); 4693 #undef MNT_FLAG 4694 if (mflags != 0) { 4695 if (buf[0] != '\0') 4696 strlcat(buf, ", ", sizeof(buf)); 4697 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4698 "0x%016jx", mflags); 4699 } 4700 db_printf(" mnt_flag = %s\n", buf); 4701 4702 buf[0] = '\0'; 4703 flags = mp->mnt_kern_flag; 4704 #define MNT_KERN_FLAG(flag) do { \ 4705 if (flags & (flag)) { \ 4706 if (buf[0] != '\0') \ 4707 strlcat(buf, ", ", sizeof(buf)); \ 4708 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 4709 flags &= ~(flag); \ 4710 } \ 4711 } while (0) 4712 MNT_KERN_FLAG(MNTK_UNMOUNTF); 4713 MNT_KERN_FLAG(MNTK_ASYNC); 4714 MNT_KERN_FLAG(MNTK_SOFTDEP); 4715 MNT_KERN_FLAG(MNTK_NOMSYNC); 4716 MNT_KERN_FLAG(MNTK_DRAINING); 4717 MNT_KERN_FLAG(MNTK_REFEXPIRE); 4718 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 4719 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 4720 MNT_KERN_FLAG(MNTK_NO_IOPF); 4721 MNT_KERN_FLAG(MNTK_RECURSE); 4722 MNT_KERN_FLAG(MNTK_UPPER_WAITER); 4723 MNT_KERN_FLAG(MNTK_UNLOCKED_INSMNTQUE); 4724 MNT_KERN_FLAG(MNTK_USES_BCACHE); 4725 MNT_KERN_FLAG(MNTK_VMSETSIZE_BUG); 4726 MNT_KERN_FLAG(MNTK_FPLOOKUP); 4727 MNT_KERN_FLAG(MNTK_TASKQUEUE_WAITER); 4728 MNT_KERN_FLAG(MNTK_NOASYNC); 4729 MNT_KERN_FLAG(MNTK_UNMOUNT); 4730 MNT_KERN_FLAG(MNTK_MWAIT); 4731 MNT_KERN_FLAG(MNTK_SUSPEND); 4732 MNT_KERN_FLAG(MNTK_SUSPEND2); 4733 MNT_KERN_FLAG(MNTK_SUSPENDED); 4734 MNT_KERN_FLAG(MNTK_NULL_NOCACHE); 4735 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 4736 #undef MNT_KERN_FLAG 4737 if (flags != 0) { 4738 if (buf[0] != '\0') 4739 strlcat(buf, ", ", sizeof(buf)); 4740 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 4741 "0x%08x", flags); 4742 } 4743 db_printf(" mnt_kern_flag = %s\n", buf); 4744 4745 db_printf(" mnt_opt = "); 4746 opt = TAILQ_FIRST(mp->mnt_opt); 4747 if (opt != NULL) { 4748 db_printf("%s", opt->name); 4749 opt = TAILQ_NEXT(opt, link); 4750 while (opt != NULL) { 4751 db_printf(", %s", opt->name); 4752 opt = TAILQ_NEXT(opt, link); 4753 } 4754 } 4755 db_printf("\n"); 4756 4757 sp = &mp->mnt_stat; 4758 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 4759 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 4760 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 4761 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 4762 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 4763 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4764 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4765 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4766 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4767 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4768 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4769 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4770 4771 db_printf(" mnt_cred = { uid=%u ruid=%u", 4772 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4773 if (jailed(mp->mnt_cred)) 4774 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4775 db_printf(" }\n"); 4776 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4777 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4778 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4779 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4780 db_printf(" mnt_lazyvnodelistsize = %d\n", 4781 mp->mnt_lazyvnodelistsize); 4782 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4783 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4784 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4785 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4786 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4787 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4788 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4789 db_printf(" mnt_secondary_accwrites = %d\n", 4790 mp->mnt_secondary_accwrites); 4791 db_printf(" mnt_gjprovider = %s\n", 4792 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4793 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4794 4795 db_printf("\n\nList of active vnodes\n"); 4796 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4797 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) { 4798 vn_printf(vp, "vnode "); 4799 if (db_pager_quit) 4800 break; 4801 } 4802 } 4803 db_printf("\n\nList of inactive vnodes\n"); 4804 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4805 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) { 4806 vn_printf(vp, "vnode "); 4807 if (db_pager_quit) 4808 break; 4809 } 4810 } 4811 } 4812 #endif /* DDB */ 4813 4814 /* 4815 * Fill in a struct xvfsconf based on a struct vfsconf. 4816 */ 4817 static int 4818 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4819 { 4820 struct xvfsconf xvfsp; 4821 4822 bzero(&xvfsp, sizeof(xvfsp)); 4823 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4824 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4825 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4826 xvfsp.vfc_flags = vfsp->vfc_flags; 4827 /* 4828 * These are unused in userland, we keep them 4829 * to not break binary compatibility. 4830 */ 4831 xvfsp.vfc_vfsops = NULL; 4832 xvfsp.vfc_next = NULL; 4833 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4834 } 4835 4836 #ifdef COMPAT_FREEBSD32 4837 struct xvfsconf32 { 4838 uint32_t vfc_vfsops; 4839 char vfc_name[MFSNAMELEN]; 4840 int32_t vfc_typenum; 4841 int32_t vfc_refcount; 4842 int32_t vfc_flags; 4843 uint32_t vfc_next; 4844 }; 4845 4846 static int 4847 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4848 { 4849 struct xvfsconf32 xvfsp; 4850 4851 bzero(&xvfsp, sizeof(xvfsp)); 4852 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4853 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4854 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4855 xvfsp.vfc_flags = vfsp->vfc_flags; 4856 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4857 } 4858 #endif 4859 4860 /* 4861 * Top level filesystem related information gathering. 4862 */ 4863 static int 4864 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4865 { 4866 struct vfsconf *vfsp; 4867 int error; 4868 4869 error = 0; 4870 vfsconf_slock(); 4871 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4872 #ifdef COMPAT_FREEBSD32 4873 if (req->flags & SCTL_MASK32) 4874 error = vfsconf2x32(req, vfsp); 4875 else 4876 #endif 4877 error = vfsconf2x(req, vfsp); 4878 if (error) 4879 break; 4880 } 4881 vfsconf_sunlock(); 4882 return (error); 4883 } 4884 4885 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4886 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4887 "S,xvfsconf", "List of all configured filesystems"); 4888 4889 #ifndef BURN_BRIDGES 4890 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4891 4892 static int 4893 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4894 { 4895 int *name = (int *)arg1 - 1; /* XXX */ 4896 u_int namelen = arg2 + 1; /* XXX */ 4897 struct vfsconf *vfsp; 4898 4899 log(LOG_WARNING, "userland calling deprecated sysctl, " 4900 "please rebuild world\n"); 4901 4902 #if 1 || defined(COMPAT_PRELITE2) 4903 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4904 if (namelen == 1) 4905 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4906 #endif 4907 4908 switch (name[1]) { 4909 case VFS_MAXTYPENUM: 4910 if (namelen != 2) 4911 return (ENOTDIR); 4912 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4913 case VFS_CONF: 4914 if (namelen != 3) 4915 return (ENOTDIR); /* overloaded */ 4916 vfsconf_slock(); 4917 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4918 if (vfsp->vfc_typenum == name[2]) 4919 break; 4920 } 4921 vfsconf_sunlock(); 4922 if (vfsp == NULL) 4923 return (EOPNOTSUPP); 4924 #ifdef COMPAT_FREEBSD32 4925 if (req->flags & SCTL_MASK32) 4926 return (vfsconf2x32(req, vfsp)); 4927 else 4928 #endif 4929 return (vfsconf2x(req, vfsp)); 4930 } 4931 return (EOPNOTSUPP); 4932 } 4933 4934 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4935 CTLFLAG_MPSAFE, vfs_sysctl, 4936 "Generic filesystem"); 4937 4938 #if 1 || defined(COMPAT_PRELITE2) 4939 4940 static int 4941 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4942 { 4943 int error; 4944 struct vfsconf *vfsp; 4945 struct ovfsconf ovfs; 4946 4947 vfsconf_slock(); 4948 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4949 bzero(&ovfs, sizeof(ovfs)); 4950 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4951 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4952 ovfs.vfc_index = vfsp->vfc_typenum; 4953 ovfs.vfc_refcount = vfsp->vfc_refcount; 4954 ovfs.vfc_flags = vfsp->vfc_flags; 4955 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4956 if (error != 0) { 4957 vfsconf_sunlock(); 4958 return (error); 4959 } 4960 } 4961 vfsconf_sunlock(); 4962 return (0); 4963 } 4964 4965 #endif /* 1 || COMPAT_PRELITE2 */ 4966 #endif /* !BURN_BRIDGES */ 4967 4968 static void 4969 unmount_or_warn(struct mount *mp) 4970 { 4971 int error; 4972 4973 error = dounmount(mp, MNT_FORCE, curthread); 4974 if (error != 0) { 4975 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4976 if (error == EBUSY) 4977 printf("BUSY)\n"); 4978 else 4979 printf("%d)\n", error); 4980 } 4981 } 4982 4983 /* 4984 * Unmount all filesystems. The list is traversed in reverse order 4985 * of mounting to avoid dependencies. 4986 */ 4987 void 4988 vfs_unmountall(void) 4989 { 4990 struct mount *mp, *tmp; 4991 4992 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4993 4994 /* 4995 * Since this only runs when rebooting, it is not interlocked. 4996 */ 4997 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4998 vfs_ref(mp); 4999 5000 /* 5001 * Forcibly unmounting "/dev" before "/" would prevent clean 5002 * unmount of the latter. 5003 */ 5004 if (mp == rootdevmp) 5005 continue; 5006 5007 unmount_or_warn(mp); 5008 } 5009 5010 if (rootdevmp != NULL) 5011 unmount_or_warn(rootdevmp); 5012 } 5013 5014 static void 5015 vfs_deferred_inactive(struct vnode *vp, int lkflags) 5016 { 5017 5018 ASSERT_VI_LOCKED(vp, __func__); 5019 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp); 5020 if ((vp->v_iflag & VI_OWEINACT) == 0) { 5021 vdropl(vp); 5022 return; 5023 } 5024 if (vn_lock(vp, lkflags) == 0) { 5025 VI_LOCK(vp); 5026 vinactive(vp); 5027 VOP_UNLOCK(vp); 5028 vdropl(vp); 5029 return; 5030 } 5031 vdefer_inactive_unlocked(vp); 5032 } 5033 5034 static int 5035 vfs_periodic_inactive_filter(struct vnode *vp, void *arg) 5036 { 5037 5038 return (vp->v_iflag & VI_DEFINACT); 5039 } 5040 5041 static void __noinline 5042 vfs_periodic_inactive(struct mount *mp, int flags) 5043 { 5044 struct vnode *vp, *mvp; 5045 int lkflags; 5046 5047 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 5048 if (flags != MNT_WAIT) 5049 lkflags |= LK_NOWAIT; 5050 5051 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) { 5052 if ((vp->v_iflag & VI_DEFINACT) == 0) { 5053 VI_UNLOCK(vp); 5054 continue; 5055 } 5056 vp->v_iflag &= ~VI_DEFINACT; 5057 vfs_deferred_inactive(vp, lkflags); 5058 } 5059 } 5060 5061 static inline bool 5062 vfs_want_msync(struct vnode *vp) 5063 { 5064 struct vm_object *obj; 5065 5066 /* 5067 * This test may be performed without any locks held. 5068 * We rely on vm_object's type stability. 5069 */ 5070 if (vp->v_vflag & VV_NOSYNC) 5071 return (false); 5072 obj = vp->v_object; 5073 return (obj != NULL && vm_object_mightbedirty(obj)); 5074 } 5075 5076 static int 5077 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused) 5078 { 5079 5080 if (vp->v_vflag & VV_NOSYNC) 5081 return (false); 5082 if (vp->v_iflag & VI_DEFINACT) 5083 return (true); 5084 return (vfs_want_msync(vp)); 5085 } 5086 5087 static void __noinline 5088 vfs_periodic_msync_inactive(struct mount *mp, int flags) 5089 { 5090 struct vnode *vp, *mvp; 5091 int lkflags; 5092 bool seen_defer; 5093 5094 lkflags = LK_EXCLUSIVE | LK_INTERLOCK; 5095 if (flags != MNT_WAIT) 5096 lkflags |= LK_NOWAIT; 5097 5098 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) { 5099 seen_defer = false; 5100 if (vp->v_iflag & VI_DEFINACT) { 5101 vp->v_iflag &= ~VI_DEFINACT; 5102 seen_defer = true; 5103 } 5104 if (!vfs_want_msync(vp)) { 5105 if (seen_defer) 5106 vfs_deferred_inactive(vp, lkflags); 5107 else 5108 VI_UNLOCK(vp); 5109 continue; 5110 } 5111 if (vget(vp, lkflags) == 0) { 5112 if ((vp->v_vflag & VV_NOSYNC) == 0) { 5113 if (flags == MNT_WAIT) 5114 vnode_pager_clean_sync(vp); 5115 else 5116 vnode_pager_clean_async(vp); 5117 } 5118 vput(vp); 5119 if (seen_defer) 5120 vdrop(vp); 5121 } else { 5122 if (seen_defer) 5123 vdefer_inactive_unlocked(vp); 5124 } 5125 } 5126 } 5127 5128 void 5129 vfs_periodic(struct mount *mp, int flags) 5130 { 5131 5132 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 5133 5134 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 5135 vfs_periodic_inactive(mp, flags); 5136 else 5137 vfs_periodic_msync_inactive(mp, flags); 5138 } 5139 5140 static void 5141 destroy_vpollinfo_free(struct vpollinfo *vi) 5142 { 5143 5144 knlist_destroy(&vi->vpi_selinfo.si_note); 5145 mtx_destroy(&vi->vpi_lock); 5146 free(vi, M_VNODEPOLL); 5147 } 5148 5149 static void 5150 destroy_vpollinfo(struct vpollinfo *vi) 5151 { 5152 5153 knlist_clear(&vi->vpi_selinfo.si_note, 1); 5154 seldrain(&vi->vpi_selinfo); 5155 destroy_vpollinfo_free(vi); 5156 } 5157 5158 /* 5159 * Initialize per-vnode helper structure to hold poll-related state. 5160 */ 5161 void 5162 v_addpollinfo(struct vnode *vp) 5163 { 5164 struct vpollinfo *vi; 5165 5166 if (vp->v_pollinfo != NULL) 5167 return; 5168 vi = malloc(sizeof(*vi), M_VNODEPOLL, M_WAITOK | M_ZERO); 5169 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 5170 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 5171 vfs_knlunlock, vfs_knl_assert_lock); 5172 VI_LOCK(vp); 5173 if (vp->v_pollinfo != NULL) { 5174 VI_UNLOCK(vp); 5175 destroy_vpollinfo_free(vi); 5176 return; 5177 } 5178 vp->v_pollinfo = vi; 5179 VI_UNLOCK(vp); 5180 } 5181 5182 /* 5183 * Record a process's interest in events which might happen to 5184 * a vnode. Because poll uses the historic select-style interface 5185 * internally, this routine serves as both the ``check for any 5186 * pending events'' and the ``record my interest in future events'' 5187 * functions. (These are done together, while the lock is held, 5188 * to avoid race conditions.) 5189 */ 5190 int 5191 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 5192 { 5193 5194 v_addpollinfo(vp); 5195 mtx_lock(&vp->v_pollinfo->vpi_lock); 5196 if (vp->v_pollinfo->vpi_revents & events) { 5197 /* 5198 * This leaves events we are not interested 5199 * in available for the other process which 5200 * which presumably had requested them 5201 * (otherwise they would never have been 5202 * recorded). 5203 */ 5204 events &= vp->v_pollinfo->vpi_revents; 5205 vp->v_pollinfo->vpi_revents &= ~events; 5206 5207 mtx_unlock(&vp->v_pollinfo->vpi_lock); 5208 return (events); 5209 } 5210 vp->v_pollinfo->vpi_events |= events; 5211 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 5212 mtx_unlock(&vp->v_pollinfo->vpi_lock); 5213 return (0); 5214 } 5215 5216 /* 5217 * Routine to create and manage a filesystem syncer vnode. 5218 */ 5219 #define sync_close ((int (*)(struct vop_close_args *))nullop) 5220 static int sync_fsync(struct vop_fsync_args *); 5221 static int sync_inactive(struct vop_inactive_args *); 5222 static int sync_reclaim(struct vop_reclaim_args *); 5223 5224 static struct vop_vector sync_vnodeops = { 5225 .vop_bypass = VOP_EOPNOTSUPP, 5226 .vop_close = sync_close, 5227 .vop_fsync = sync_fsync, 5228 .vop_getwritemount = vop_stdgetwritemount, 5229 .vop_inactive = sync_inactive, 5230 .vop_need_inactive = vop_stdneed_inactive, 5231 .vop_reclaim = sync_reclaim, 5232 .vop_lock1 = vop_stdlock, 5233 .vop_unlock = vop_stdunlock, 5234 .vop_islocked = vop_stdislocked, 5235 .vop_fplookup_vexec = VOP_EAGAIN, 5236 .vop_fplookup_symlink = VOP_EAGAIN, 5237 }; 5238 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 5239 5240 /* 5241 * Create a new filesystem syncer vnode for the specified mount point. 5242 */ 5243 void 5244 vfs_allocate_syncvnode(struct mount *mp) 5245 { 5246 struct vnode *vp; 5247 struct bufobj *bo; 5248 static long start, incr, next; 5249 int error; 5250 5251 /* Allocate a new vnode */ 5252 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 5253 if (error != 0) 5254 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 5255 vp->v_type = VNON; 5256 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5257 vp->v_vflag |= VV_FORCEINSMQ; 5258 error = insmntque1(vp, mp); 5259 if (error != 0) 5260 panic("vfs_allocate_syncvnode: insmntque() failed"); 5261 vp->v_vflag &= ~VV_FORCEINSMQ; 5262 vn_set_state(vp, VSTATE_CONSTRUCTED); 5263 VOP_UNLOCK(vp); 5264 /* 5265 * Place the vnode onto the syncer worklist. We attempt to 5266 * scatter them about on the list so that they will go off 5267 * at evenly distributed times even if all the filesystems 5268 * are mounted at once. 5269 */ 5270 next += incr; 5271 if (next == 0 || next > syncer_maxdelay) { 5272 start /= 2; 5273 incr /= 2; 5274 if (start == 0) { 5275 start = syncer_maxdelay / 2; 5276 incr = syncer_maxdelay; 5277 } 5278 next = start; 5279 } 5280 bo = &vp->v_bufobj; 5281 BO_LOCK(bo); 5282 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 5283 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 5284 mtx_lock(&sync_mtx); 5285 sync_vnode_count++; 5286 if (mp->mnt_syncer == NULL) { 5287 mp->mnt_syncer = vp; 5288 vp = NULL; 5289 } 5290 mtx_unlock(&sync_mtx); 5291 BO_UNLOCK(bo); 5292 if (vp != NULL) { 5293 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5294 vgone(vp); 5295 vput(vp); 5296 } 5297 } 5298 5299 void 5300 vfs_deallocate_syncvnode(struct mount *mp) 5301 { 5302 struct vnode *vp; 5303 5304 mtx_lock(&sync_mtx); 5305 vp = mp->mnt_syncer; 5306 if (vp != NULL) 5307 mp->mnt_syncer = NULL; 5308 mtx_unlock(&sync_mtx); 5309 if (vp != NULL) 5310 vrele(vp); 5311 } 5312 5313 /* 5314 * Do a lazy sync of the filesystem. 5315 */ 5316 static int 5317 sync_fsync(struct vop_fsync_args *ap) 5318 { 5319 struct vnode *syncvp = ap->a_vp; 5320 struct mount *mp = syncvp->v_mount; 5321 int error, save; 5322 struct bufobj *bo; 5323 5324 /* 5325 * We only need to do something if this is a lazy evaluation. 5326 */ 5327 if (ap->a_waitfor != MNT_LAZY) 5328 return (0); 5329 5330 /* 5331 * Move ourselves to the back of the sync list. 5332 */ 5333 bo = &syncvp->v_bufobj; 5334 BO_LOCK(bo); 5335 vn_syncer_add_to_worklist(bo, syncdelay); 5336 BO_UNLOCK(bo); 5337 5338 /* 5339 * Walk the list of vnodes pushing all that are dirty and 5340 * not already on the sync list. 5341 */ 5342 if (vfs_busy(mp, MBF_NOWAIT) != 0) 5343 return (0); 5344 VOP_UNLOCK(syncvp); 5345 save = curthread_pflags_set(TDP_SYNCIO); 5346 /* 5347 * The filesystem at hand may be idle with free vnodes stored in the 5348 * batch. Return them instead of letting them stay there indefinitely. 5349 */ 5350 vfs_periodic(mp, MNT_NOWAIT); 5351 error = VFS_SYNC(mp, MNT_LAZY); 5352 curthread_pflags_restore(save); 5353 vn_lock(syncvp, LK_EXCLUSIVE | LK_RETRY); 5354 vfs_unbusy(mp); 5355 return (error); 5356 } 5357 5358 /* 5359 * The syncer vnode is no referenced. 5360 */ 5361 static int 5362 sync_inactive(struct vop_inactive_args *ap) 5363 { 5364 5365 vgone(ap->a_vp); 5366 return (0); 5367 } 5368 5369 /* 5370 * The syncer vnode is no longer needed and is being decommissioned. 5371 * 5372 * Modifications to the worklist must be protected by sync_mtx. 5373 */ 5374 static int 5375 sync_reclaim(struct vop_reclaim_args *ap) 5376 { 5377 struct vnode *vp = ap->a_vp; 5378 struct bufobj *bo; 5379 5380 bo = &vp->v_bufobj; 5381 BO_LOCK(bo); 5382 mtx_lock(&sync_mtx); 5383 if (vp->v_mount->mnt_syncer == vp) 5384 vp->v_mount->mnt_syncer = NULL; 5385 if (bo->bo_flag & BO_ONWORKLST) { 5386 LIST_REMOVE(bo, bo_synclist); 5387 syncer_worklist_len--; 5388 sync_vnode_count--; 5389 bo->bo_flag &= ~BO_ONWORKLST; 5390 } 5391 mtx_unlock(&sync_mtx); 5392 BO_UNLOCK(bo); 5393 5394 return (0); 5395 } 5396 5397 int 5398 vn_need_pageq_flush(struct vnode *vp) 5399 { 5400 struct vm_object *obj; 5401 5402 obj = vp->v_object; 5403 return (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 5404 vm_object_mightbedirty(obj)); 5405 } 5406 5407 /* 5408 * Check if vnode represents a disk device 5409 */ 5410 bool 5411 vn_isdisk_error(struct vnode *vp, int *errp) 5412 { 5413 int error; 5414 5415 if (vp->v_type != VCHR) { 5416 error = ENOTBLK; 5417 goto out; 5418 } 5419 error = 0; 5420 dev_lock(); 5421 if (vp->v_rdev == NULL) 5422 error = ENXIO; 5423 else if (vp->v_rdev->si_devsw == NULL) 5424 error = ENXIO; 5425 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 5426 error = ENOTBLK; 5427 dev_unlock(); 5428 out: 5429 *errp = error; 5430 return (error == 0); 5431 } 5432 5433 bool 5434 vn_isdisk(struct vnode *vp) 5435 { 5436 int error; 5437 5438 return (vn_isdisk_error(vp, &error)); 5439 } 5440 5441 /* 5442 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see 5443 * the comment above cache_fplookup for details. 5444 */ 5445 int 5446 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred) 5447 { 5448 int error; 5449 5450 VFS_SMR_ASSERT_ENTERED(); 5451 5452 /* Check the owner. */ 5453 if (cred->cr_uid == file_uid) { 5454 if (file_mode & S_IXUSR) 5455 return (0); 5456 goto out_error; 5457 } 5458 5459 /* Otherwise, check the groups (first match) */ 5460 if (groupmember(file_gid, cred)) { 5461 if (file_mode & S_IXGRP) 5462 return (0); 5463 goto out_error; 5464 } 5465 5466 /* Otherwise, check everyone else. */ 5467 if (file_mode & S_IXOTH) 5468 return (0); 5469 out_error: 5470 /* 5471 * Permission check failed, but it is possible denial will get overwritten 5472 * (e.g., when root is traversing through a 700 directory owned by someone 5473 * else). 5474 * 5475 * vaccess() calls priv_check_cred which in turn can descent into MAC 5476 * modules overriding this result. It's quite unclear what semantics 5477 * are allowed for them to operate, thus for safety we don't call them 5478 * from within the SMR section. This also means if any such modules 5479 * are present, we have to let the regular lookup decide. 5480 */ 5481 error = priv_check_cred_vfs_lookup_nomac(cred); 5482 switch (error) { 5483 case 0: 5484 return (0); 5485 case EAGAIN: 5486 /* 5487 * MAC modules present. 5488 */ 5489 return (EAGAIN); 5490 case EPERM: 5491 return (EACCES); 5492 default: 5493 return (error); 5494 } 5495 } 5496 5497 /* 5498 * Common filesystem object access control check routine. Accepts a 5499 * vnode's type, "mode", uid and gid, requested access mode, and credentials. 5500 * Returns 0 on success, or an errno on failure. 5501 */ 5502 int 5503 vaccess(__enum_uint8(vtype) type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 5504 accmode_t accmode, struct ucred *cred) 5505 { 5506 accmode_t dac_granted; 5507 accmode_t priv_granted; 5508 5509 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 5510 ("invalid bit in accmode")); 5511 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 5512 ("VAPPEND without VWRITE")); 5513 5514 /* 5515 * Look for a normal, non-privileged way to access the file/directory 5516 * as requested. If it exists, go with that. 5517 */ 5518 5519 dac_granted = 0; 5520 5521 /* Check the owner. */ 5522 if (cred->cr_uid == file_uid) { 5523 dac_granted |= VADMIN; 5524 if (file_mode & S_IXUSR) 5525 dac_granted |= VEXEC; 5526 if (file_mode & S_IRUSR) 5527 dac_granted |= VREAD; 5528 if (file_mode & S_IWUSR) 5529 dac_granted |= (VWRITE | VAPPEND); 5530 5531 if ((accmode & dac_granted) == accmode) 5532 return (0); 5533 5534 goto privcheck; 5535 } 5536 5537 /* Otherwise, check the groups (first match) */ 5538 if (groupmember(file_gid, cred)) { 5539 if (file_mode & S_IXGRP) 5540 dac_granted |= VEXEC; 5541 if (file_mode & S_IRGRP) 5542 dac_granted |= VREAD; 5543 if (file_mode & S_IWGRP) 5544 dac_granted |= (VWRITE | VAPPEND); 5545 5546 if ((accmode & dac_granted) == accmode) 5547 return (0); 5548 5549 goto privcheck; 5550 } 5551 5552 /* Otherwise, check everyone else. */ 5553 if (file_mode & S_IXOTH) 5554 dac_granted |= VEXEC; 5555 if (file_mode & S_IROTH) 5556 dac_granted |= VREAD; 5557 if (file_mode & S_IWOTH) 5558 dac_granted |= (VWRITE | VAPPEND); 5559 if ((accmode & dac_granted) == accmode) 5560 return (0); 5561 5562 privcheck: 5563 /* 5564 * Build a privilege mask to determine if the set of privileges 5565 * satisfies the requirements when combined with the granted mask 5566 * from above. For each privilege, if the privilege is required, 5567 * bitwise or the request type onto the priv_granted mask. 5568 */ 5569 priv_granted = 0; 5570 5571 if (type == VDIR) { 5572 /* 5573 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 5574 * requests, instead of PRIV_VFS_EXEC. 5575 */ 5576 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5577 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 5578 priv_granted |= VEXEC; 5579 } else { 5580 /* 5581 * Ensure that at least one execute bit is on. Otherwise, 5582 * a privileged user will always succeed, and we don't want 5583 * this to happen unless the file really is executable. 5584 */ 5585 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 5586 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 5587 !priv_check_cred(cred, PRIV_VFS_EXEC)) 5588 priv_granted |= VEXEC; 5589 } 5590 5591 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 5592 !priv_check_cred(cred, PRIV_VFS_READ)) 5593 priv_granted |= VREAD; 5594 5595 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 5596 !priv_check_cred(cred, PRIV_VFS_WRITE)) 5597 priv_granted |= (VWRITE | VAPPEND); 5598 5599 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 5600 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 5601 priv_granted |= VADMIN; 5602 5603 if ((accmode & (priv_granted | dac_granted)) == accmode) { 5604 return (0); 5605 } 5606 5607 return ((accmode & VADMIN) ? EPERM : EACCES); 5608 } 5609 5610 /* 5611 * Credential check based on process requesting service, and per-attribute 5612 * permissions. 5613 */ 5614 int 5615 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 5616 struct thread *td, accmode_t accmode) 5617 { 5618 5619 /* 5620 * Kernel-invoked always succeeds. 5621 */ 5622 if (cred == NOCRED) 5623 return (0); 5624 5625 /* 5626 * Do not allow privileged processes in jail to directly manipulate 5627 * system attributes. 5628 */ 5629 switch (attrnamespace) { 5630 case EXTATTR_NAMESPACE_SYSTEM: 5631 /* Potentially should be: return (EPERM); */ 5632 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 5633 case EXTATTR_NAMESPACE_USER: 5634 return (VOP_ACCESS(vp, accmode, cred, td)); 5635 default: 5636 return (EPERM); 5637 } 5638 } 5639 5640 #ifdef DEBUG_VFS_LOCKS 5641 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 5642 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 5643 "Drop into debugger on lock violation"); 5644 5645 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 5646 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 5647 0, "Check for interlock across VOPs"); 5648 5649 int vfs_badlock_print = 1; /* Print lock violations. */ 5650 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 5651 0, "Print lock violations"); 5652 5653 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 5654 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 5655 0, "Print vnode details on lock violations"); 5656 5657 #ifdef KDB 5658 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 5659 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 5660 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 5661 #endif 5662 5663 static void 5664 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 5665 { 5666 5667 #ifdef KDB 5668 if (vfs_badlock_backtrace) 5669 kdb_backtrace(); 5670 #endif 5671 if (vfs_badlock_vnode) 5672 vn_printf(vp, "vnode "); 5673 if (vfs_badlock_print) 5674 printf("%s: %p %s\n", str, (void *)vp, msg); 5675 if (vfs_badlock_ddb) 5676 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5677 } 5678 5679 void 5680 assert_vi_locked(struct vnode *vp, const char *str) 5681 { 5682 5683 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 5684 vfs_badlock("interlock is not locked but should be", str, vp); 5685 } 5686 5687 void 5688 assert_vi_unlocked(struct vnode *vp, const char *str) 5689 { 5690 5691 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 5692 vfs_badlock("interlock is locked but should not be", str, vp); 5693 } 5694 5695 void 5696 assert_vop_locked(struct vnode *vp, const char *str) 5697 { 5698 if (KERNEL_PANICKED() || vp == NULL) 5699 return; 5700 5701 #ifdef WITNESS 5702 if ((vp->v_irflag & VIRF_CROSSMP) == 0 && 5703 witness_is_owned(&vp->v_vnlock->lock_object) == -1) 5704 #else 5705 int locked = VOP_ISLOCKED(vp); 5706 if (locked == 0 || locked == LK_EXCLOTHER) 5707 #endif 5708 vfs_badlock("is not locked but should be", str, vp); 5709 } 5710 5711 void 5712 assert_vop_unlocked(struct vnode *vp, const char *str) 5713 { 5714 if (KERNEL_PANICKED() || vp == NULL) 5715 return; 5716 5717 #ifdef WITNESS 5718 if ((vp->v_irflag & VIRF_CROSSMP) == 0 && 5719 witness_is_owned(&vp->v_vnlock->lock_object) == 1) 5720 #else 5721 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 5722 #endif 5723 vfs_badlock("is locked but should not be", str, vp); 5724 } 5725 5726 void 5727 assert_vop_elocked(struct vnode *vp, const char *str) 5728 { 5729 if (KERNEL_PANICKED() || vp == NULL) 5730 return; 5731 5732 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 5733 vfs_badlock("is not exclusive locked but should be", str, vp); 5734 } 5735 #endif /* DEBUG_VFS_LOCKS */ 5736 5737 void 5738 vop_rename_fail(struct vop_rename_args *ap) 5739 { 5740 5741 if (ap->a_tvp != NULL) 5742 vput(ap->a_tvp); 5743 if (ap->a_tdvp == ap->a_tvp) 5744 vrele(ap->a_tdvp); 5745 else 5746 vput(ap->a_tdvp); 5747 vrele(ap->a_fdvp); 5748 vrele(ap->a_fvp); 5749 } 5750 5751 void 5752 vop_rename_pre(void *ap) 5753 { 5754 struct vop_rename_args *a = ap; 5755 5756 #ifdef DEBUG_VFS_LOCKS 5757 if (a->a_tvp) 5758 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 5759 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 5760 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 5761 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 5762 5763 /* Check the source (from). */ 5764 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 5765 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 5766 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 5767 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 5768 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 5769 5770 /* Check the target. */ 5771 if (a->a_tvp) 5772 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 5773 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 5774 #endif 5775 /* 5776 * It may be tempting to add vn_seqc_write_begin/end calls here and 5777 * in vop_rename_post but that's not going to work out since some 5778 * filesystems relookup vnodes mid-rename. This is probably a bug. 5779 * 5780 * For now filesystems are expected to do the relevant calls after they 5781 * decide what vnodes to operate on. 5782 */ 5783 if (a->a_tdvp != a->a_fdvp) 5784 vhold(a->a_fdvp); 5785 if (a->a_tvp != a->a_fvp) 5786 vhold(a->a_fvp); 5787 vhold(a->a_tdvp); 5788 if (a->a_tvp) 5789 vhold(a->a_tvp); 5790 } 5791 5792 #ifdef DEBUG_VFS_LOCKS 5793 void 5794 vop_fplookup_vexec_debugpre(void *ap __unused) 5795 { 5796 5797 VFS_SMR_ASSERT_ENTERED(); 5798 } 5799 5800 void 5801 vop_fplookup_vexec_debugpost(void *ap, int rc) 5802 { 5803 struct vop_fplookup_vexec_args *a; 5804 struct vnode *vp; 5805 5806 a = ap; 5807 vp = a->a_vp; 5808 5809 VFS_SMR_ASSERT_ENTERED(); 5810 if (rc == EOPNOTSUPP) 5811 VNPASS(VN_IS_DOOMED(vp), vp); 5812 } 5813 5814 void 5815 vop_fplookup_symlink_debugpre(void *ap __unused) 5816 { 5817 5818 VFS_SMR_ASSERT_ENTERED(); 5819 } 5820 5821 void 5822 vop_fplookup_symlink_debugpost(void *ap __unused, int rc __unused) 5823 { 5824 5825 VFS_SMR_ASSERT_ENTERED(); 5826 } 5827 5828 static void 5829 vop_fsync_debugprepost(struct vnode *vp, const char *name) 5830 { 5831 if (vp->v_type == VCHR) 5832 ; 5833 /* 5834 * The shared vs. exclusive locking policy for fsync() 5835 * is actually determined by vp's write mount as indicated 5836 * by VOP_GETWRITEMOUNT(), which for stacked filesystems 5837 * may not be the same as vp->v_mount. However, if the 5838 * underlying filesystem which really handles the fsync() 5839 * supports shared locking, the stacked filesystem must also 5840 * be prepared for its VOP_FSYNC() operation to be called 5841 * with only a shared lock. On the other hand, if the 5842 * stacked filesystem claims support for shared write 5843 * locking but the underlying filesystem does not, and the 5844 * caller incorrectly uses a shared lock, this condition 5845 * should still be caught when the stacked filesystem 5846 * invokes VOP_FSYNC() on the underlying filesystem. 5847 */ 5848 else if (MNT_SHARED_WRITES(vp->v_mount)) 5849 ASSERT_VOP_LOCKED(vp, name); 5850 else 5851 ASSERT_VOP_ELOCKED(vp, name); 5852 } 5853 5854 void 5855 vop_fsync_debugpre(void *a) 5856 { 5857 struct vop_fsync_args *ap; 5858 5859 ap = a; 5860 vop_fsync_debugprepost(ap->a_vp, "fsync"); 5861 } 5862 5863 void 5864 vop_fsync_debugpost(void *a, int rc __unused) 5865 { 5866 struct vop_fsync_args *ap; 5867 5868 ap = a; 5869 vop_fsync_debugprepost(ap->a_vp, "fsync"); 5870 } 5871 5872 void 5873 vop_fdatasync_debugpre(void *a) 5874 { 5875 struct vop_fdatasync_args *ap; 5876 5877 ap = a; 5878 vop_fsync_debugprepost(ap->a_vp, "fsync"); 5879 } 5880 5881 void 5882 vop_fdatasync_debugpost(void *a, int rc __unused) 5883 { 5884 struct vop_fdatasync_args *ap; 5885 5886 ap = a; 5887 vop_fsync_debugprepost(ap->a_vp, "fsync"); 5888 } 5889 5890 void 5891 vop_strategy_debugpre(void *ap) 5892 { 5893 struct vop_strategy_args *a; 5894 struct buf *bp; 5895 5896 a = ap; 5897 bp = a->a_bp; 5898 5899 /* 5900 * Cluster ops lock their component buffers but not the IO container. 5901 */ 5902 if ((bp->b_flags & B_CLUSTER) != 0) 5903 return; 5904 5905 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) { 5906 if (vfs_badlock_print) 5907 printf( 5908 "VOP_STRATEGY: bp is not locked but should be\n"); 5909 if (vfs_badlock_ddb) 5910 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 5911 } 5912 } 5913 5914 void 5915 vop_lock_debugpre(void *ap) 5916 { 5917 struct vop_lock1_args *a = ap; 5918 5919 if ((a->a_flags & LK_INTERLOCK) == 0) 5920 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5921 else 5922 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5923 } 5924 5925 void 5926 vop_lock_debugpost(void *ap, int rc) 5927 { 5928 struct vop_lock1_args *a = ap; 5929 5930 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5931 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5932 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5933 } 5934 5935 void 5936 vop_unlock_debugpre(void *ap) 5937 { 5938 struct vop_unlock_args *a = ap; 5939 struct vnode *vp = a->a_vp; 5940 5941 VNPASS(vn_get_state(vp) != VSTATE_UNINITIALIZED, vp); 5942 ASSERT_VOP_LOCKED(vp, "VOP_UNLOCK"); 5943 } 5944 5945 void 5946 vop_need_inactive_debugpre(void *ap) 5947 { 5948 struct vop_need_inactive_args *a = ap; 5949 5950 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5951 } 5952 5953 void 5954 vop_need_inactive_debugpost(void *ap, int rc) 5955 { 5956 struct vop_need_inactive_args *a = ap; 5957 5958 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5959 } 5960 #endif 5961 5962 void 5963 vop_create_pre(void *ap) 5964 { 5965 struct vop_create_args *a; 5966 struct vnode *dvp; 5967 5968 a = ap; 5969 dvp = a->a_dvp; 5970 vn_seqc_write_begin(dvp); 5971 } 5972 5973 void 5974 vop_create_post(void *ap, int rc) 5975 { 5976 struct vop_create_args *a; 5977 struct vnode *dvp; 5978 5979 a = ap; 5980 dvp = a->a_dvp; 5981 vn_seqc_write_end(dvp); 5982 if (!rc) 5983 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 5984 } 5985 5986 void 5987 vop_whiteout_pre(void *ap) 5988 { 5989 struct vop_whiteout_args *a; 5990 struct vnode *dvp; 5991 5992 a = ap; 5993 dvp = a->a_dvp; 5994 vn_seqc_write_begin(dvp); 5995 } 5996 5997 void 5998 vop_whiteout_post(void *ap, int rc) 5999 { 6000 struct vop_whiteout_args *a; 6001 struct vnode *dvp; 6002 6003 a = ap; 6004 dvp = a->a_dvp; 6005 vn_seqc_write_end(dvp); 6006 } 6007 6008 void 6009 vop_deleteextattr_pre(void *ap) 6010 { 6011 struct vop_deleteextattr_args *a; 6012 struct vnode *vp; 6013 6014 a = ap; 6015 vp = a->a_vp; 6016 vn_seqc_write_begin(vp); 6017 } 6018 6019 void 6020 vop_deleteextattr_post(void *ap, int rc) 6021 { 6022 struct vop_deleteextattr_args *a; 6023 struct vnode *vp; 6024 6025 a = ap; 6026 vp = a->a_vp; 6027 vn_seqc_write_end(vp); 6028 if (!rc) 6029 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 6030 } 6031 6032 void 6033 vop_link_pre(void *ap) 6034 { 6035 struct vop_link_args *a; 6036 struct vnode *vp, *tdvp; 6037 6038 a = ap; 6039 vp = a->a_vp; 6040 tdvp = a->a_tdvp; 6041 vn_seqc_write_begin(vp); 6042 vn_seqc_write_begin(tdvp); 6043 } 6044 6045 void 6046 vop_link_post(void *ap, int rc) 6047 { 6048 struct vop_link_args *a; 6049 struct vnode *vp, *tdvp; 6050 6051 a = ap; 6052 vp = a->a_vp; 6053 tdvp = a->a_tdvp; 6054 vn_seqc_write_end(vp); 6055 vn_seqc_write_end(tdvp); 6056 if (!rc) { 6057 VFS_KNOTE_LOCKED(vp, NOTE_LINK); 6058 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE); 6059 } 6060 } 6061 6062 void 6063 vop_mkdir_pre(void *ap) 6064 { 6065 struct vop_mkdir_args *a; 6066 struct vnode *dvp; 6067 6068 a = ap; 6069 dvp = a->a_dvp; 6070 vn_seqc_write_begin(dvp); 6071 } 6072 6073 void 6074 vop_mkdir_post(void *ap, int rc) 6075 { 6076 struct vop_mkdir_args *a; 6077 struct vnode *dvp; 6078 6079 a = ap; 6080 dvp = a->a_dvp; 6081 vn_seqc_write_end(dvp); 6082 if (!rc) 6083 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 6084 } 6085 6086 #ifdef DEBUG_VFS_LOCKS 6087 void 6088 vop_mkdir_debugpost(void *ap, int rc) 6089 { 6090 struct vop_mkdir_args *a; 6091 6092 a = ap; 6093 if (!rc) 6094 cache_validate(a->a_dvp, *a->a_vpp, a->a_cnp); 6095 } 6096 #endif 6097 6098 void 6099 vop_mknod_pre(void *ap) 6100 { 6101 struct vop_mknod_args *a; 6102 struct vnode *dvp; 6103 6104 a = ap; 6105 dvp = a->a_dvp; 6106 vn_seqc_write_begin(dvp); 6107 } 6108 6109 void 6110 vop_mknod_post(void *ap, int rc) 6111 { 6112 struct vop_mknod_args *a; 6113 struct vnode *dvp; 6114 6115 a = ap; 6116 dvp = a->a_dvp; 6117 vn_seqc_write_end(dvp); 6118 if (!rc) 6119 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 6120 } 6121 6122 void 6123 vop_reclaim_post(void *ap, int rc) 6124 { 6125 struct vop_reclaim_args *a; 6126 struct vnode *vp; 6127 6128 a = ap; 6129 vp = a->a_vp; 6130 ASSERT_VOP_IN_SEQC(vp); 6131 if (!rc) 6132 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE); 6133 } 6134 6135 void 6136 vop_remove_pre(void *ap) 6137 { 6138 struct vop_remove_args *a; 6139 struct vnode *dvp, *vp; 6140 6141 a = ap; 6142 dvp = a->a_dvp; 6143 vp = a->a_vp; 6144 vn_seqc_write_begin(dvp); 6145 vn_seqc_write_begin(vp); 6146 } 6147 6148 void 6149 vop_remove_post(void *ap, int rc) 6150 { 6151 struct vop_remove_args *a; 6152 struct vnode *dvp, *vp; 6153 6154 a = ap; 6155 dvp = a->a_dvp; 6156 vp = a->a_vp; 6157 vn_seqc_write_end(dvp); 6158 vn_seqc_write_end(vp); 6159 if (!rc) { 6160 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 6161 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 6162 } 6163 } 6164 6165 void 6166 vop_rename_post(void *ap, int rc) 6167 { 6168 struct vop_rename_args *a = ap; 6169 long hint; 6170 6171 if (!rc) { 6172 hint = NOTE_WRITE; 6173 if (a->a_fdvp == a->a_tdvp) { 6174 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 6175 hint |= NOTE_LINK; 6176 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 6177 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 6178 } else { 6179 hint |= NOTE_EXTEND; 6180 if (a->a_fvp->v_type == VDIR) 6181 hint |= NOTE_LINK; 6182 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 6183 6184 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 6185 a->a_tvp->v_type == VDIR) 6186 hint &= ~NOTE_LINK; 6187 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 6188 } 6189 6190 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 6191 if (a->a_tvp) 6192 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 6193 } 6194 if (a->a_tdvp != a->a_fdvp) 6195 vdrop(a->a_fdvp); 6196 if (a->a_tvp != a->a_fvp) 6197 vdrop(a->a_fvp); 6198 vdrop(a->a_tdvp); 6199 if (a->a_tvp) 6200 vdrop(a->a_tvp); 6201 } 6202 6203 void 6204 vop_rmdir_pre(void *ap) 6205 { 6206 struct vop_rmdir_args *a; 6207 struct vnode *dvp, *vp; 6208 6209 a = ap; 6210 dvp = a->a_dvp; 6211 vp = a->a_vp; 6212 vn_seqc_write_begin(dvp); 6213 vn_seqc_write_begin(vp); 6214 } 6215 6216 void 6217 vop_rmdir_post(void *ap, int rc) 6218 { 6219 struct vop_rmdir_args *a; 6220 struct vnode *dvp, *vp; 6221 6222 a = ap; 6223 dvp = a->a_dvp; 6224 vp = a->a_vp; 6225 vn_seqc_write_end(dvp); 6226 vn_seqc_write_end(vp); 6227 if (!rc) { 6228 vp->v_vflag |= VV_UNLINKED; 6229 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK); 6230 VFS_KNOTE_LOCKED(vp, NOTE_DELETE); 6231 } 6232 } 6233 6234 void 6235 vop_setattr_pre(void *ap) 6236 { 6237 struct vop_setattr_args *a; 6238 struct vnode *vp; 6239 6240 a = ap; 6241 vp = a->a_vp; 6242 vn_seqc_write_begin(vp); 6243 } 6244 6245 void 6246 vop_setattr_post(void *ap, int rc) 6247 { 6248 struct vop_setattr_args *a; 6249 struct vnode *vp; 6250 6251 a = ap; 6252 vp = a->a_vp; 6253 vn_seqc_write_end(vp); 6254 if (!rc) 6255 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 6256 } 6257 6258 void 6259 vop_setacl_pre(void *ap) 6260 { 6261 struct vop_setacl_args *a; 6262 struct vnode *vp; 6263 6264 a = ap; 6265 vp = a->a_vp; 6266 vn_seqc_write_begin(vp); 6267 } 6268 6269 void 6270 vop_setacl_post(void *ap, int rc __unused) 6271 { 6272 struct vop_setacl_args *a; 6273 struct vnode *vp; 6274 6275 a = ap; 6276 vp = a->a_vp; 6277 vn_seqc_write_end(vp); 6278 } 6279 6280 void 6281 vop_setextattr_pre(void *ap) 6282 { 6283 struct vop_setextattr_args *a; 6284 struct vnode *vp; 6285 6286 a = ap; 6287 vp = a->a_vp; 6288 vn_seqc_write_begin(vp); 6289 } 6290 6291 void 6292 vop_setextattr_post(void *ap, int rc) 6293 { 6294 struct vop_setextattr_args *a; 6295 struct vnode *vp; 6296 6297 a = ap; 6298 vp = a->a_vp; 6299 vn_seqc_write_end(vp); 6300 if (!rc) 6301 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB); 6302 } 6303 6304 void 6305 vop_symlink_pre(void *ap) 6306 { 6307 struct vop_symlink_args *a; 6308 struct vnode *dvp; 6309 6310 a = ap; 6311 dvp = a->a_dvp; 6312 vn_seqc_write_begin(dvp); 6313 } 6314 6315 void 6316 vop_symlink_post(void *ap, int rc) 6317 { 6318 struct vop_symlink_args *a; 6319 struct vnode *dvp; 6320 6321 a = ap; 6322 dvp = a->a_dvp; 6323 vn_seqc_write_end(dvp); 6324 if (!rc) 6325 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE); 6326 } 6327 6328 void 6329 vop_open_post(void *ap, int rc) 6330 { 6331 struct vop_open_args *a = ap; 6332 6333 if (!rc) 6334 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 6335 } 6336 6337 void 6338 vop_close_post(void *ap, int rc) 6339 { 6340 struct vop_close_args *a = ap; 6341 6342 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 6343 !VN_IS_DOOMED(a->a_vp))) { 6344 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 6345 NOTE_CLOSE_WRITE : NOTE_CLOSE); 6346 } 6347 } 6348 6349 void 6350 vop_read_post(void *ap, int rc) 6351 { 6352 struct vop_read_args *a = ap; 6353 6354 if (!rc) 6355 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 6356 } 6357 6358 void 6359 vop_read_pgcache_post(void *ap, int rc) 6360 { 6361 struct vop_read_pgcache_args *a = ap; 6362 6363 if (!rc) 6364 VFS_KNOTE_UNLOCKED(a->a_vp, NOTE_READ); 6365 } 6366 6367 void 6368 vop_readdir_post(void *ap, int rc) 6369 { 6370 struct vop_readdir_args *a = ap; 6371 6372 if (!rc) 6373 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 6374 } 6375 6376 static struct knlist fs_knlist; 6377 6378 static void 6379 vfs_event_init(void *arg) 6380 { 6381 knlist_init_mtx(&fs_knlist, NULL); 6382 } 6383 /* XXX - correct order? */ 6384 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 6385 6386 void 6387 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 6388 { 6389 6390 KNOTE_UNLOCKED(&fs_knlist, event); 6391 } 6392 6393 static int filt_fsattach(struct knote *kn); 6394 static void filt_fsdetach(struct knote *kn); 6395 static int filt_fsevent(struct knote *kn, long hint); 6396 6397 struct filterops fs_filtops = { 6398 .f_isfd = 0, 6399 .f_attach = filt_fsattach, 6400 .f_detach = filt_fsdetach, 6401 .f_event = filt_fsevent 6402 }; 6403 6404 static int 6405 filt_fsattach(struct knote *kn) 6406 { 6407 6408 kn->kn_flags |= EV_CLEAR; 6409 knlist_add(&fs_knlist, kn, 0); 6410 return (0); 6411 } 6412 6413 static void 6414 filt_fsdetach(struct knote *kn) 6415 { 6416 6417 knlist_remove(&fs_knlist, kn, 0); 6418 } 6419 6420 static int 6421 filt_fsevent(struct knote *kn, long hint) 6422 { 6423 6424 kn->kn_fflags |= kn->kn_sfflags & hint; 6425 6426 return (kn->kn_fflags != 0); 6427 } 6428 6429 static int 6430 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 6431 { 6432 struct vfsidctl vc; 6433 int error; 6434 struct mount *mp; 6435 6436 error = SYSCTL_IN(req, &vc, sizeof(vc)); 6437 if (error) 6438 return (error); 6439 if (vc.vc_vers != VFS_CTL_VERS1) 6440 return (EINVAL); 6441 mp = vfs_getvfs(&vc.vc_fsid); 6442 if (mp == NULL) 6443 return (ENOENT); 6444 /* ensure that a specific sysctl goes to the right filesystem. */ 6445 if (strcmp(vc.vc_fstypename, "*") != 0 && 6446 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 6447 vfs_rel(mp); 6448 return (EINVAL); 6449 } 6450 VCTLTOREQ(&vc, req); 6451 error = VFS_SYSCTL(mp, vc.vc_op, req); 6452 vfs_rel(mp); 6453 return (error); 6454 } 6455 6456 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR, 6457 NULL, 0, sysctl_vfs_ctl, "", 6458 "Sysctl by fsid"); 6459 6460 /* 6461 * Function to initialize a va_filerev field sensibly. 6462 * XXX: Wouldn't a random number make a lot more sense ?? 6463 */ 6464 u_quad_t 6465 init_va_filerev(void) 6466 { 6467 struct bintime bt; 6468 6469 getbinuptime(&bt); 6470 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 6471 } 6472 6473 static int filt_vfsread(struct knote *kn, long hint); 6474 static int filt_vfswrite(struct knote *kn, long hint); 6475 static int filt_vfsvnode(struct knote *kn, long hint); 6476 static void filt_vfsdetach(struct knote *kn); 6477 static struct filterops vfsread_filtops = { 6478 .f_isfd = 1, 6479 .f_detach = filt_vfsdetach, 6480 .f_event = filt_vfsread 6481 }; 6482 static struct filterops vfswrite_filtops = { 6483 .f_isfd = 1, 6484 .f_detach = filt_vfsdetach, 6485 .f_event = filt_vfswrite 6486 }; 6487 static struct filterops vfsvnode_filtops = { 6488 .f_isfd = 1, 6489 .f_detach = filt_vfsdetach, 6490 .f_event = filt_vfsvnode 6491 }; 6492 6493 static void 6494 vfs_knllock(void *arg) 6495 { 6496 struct vnode *vp = arg; 6497 6498 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 6499 } 6500 6501 static void 6502 vfs_knlunlock(void *arg) 6503 { 6504 struct vnode *vp = arg; 6505 6506 VOP_UNLOCK(vp); 6507 } 6508 6509 static void 6510 vfs_knl_assert_lock(void *arg, int what) 6511 { 6512 #ifdef DEBUG_VFS_LOCKS 6513 struct vnode *vp = arg; 6514 6515 if (what == LA_LOCKED) 6516 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 6517 else 6518 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 6519 #endif 6520 } 6521 6522 int 6523 vfs_kqfilter(struct vop_kqfilter_args *ap) 6524 { 6525 struct vnode *vp = ap->a_vp; 6526 struct knote *kn = ap->a_kn; 6527 struct knlist *knl; 6528 6529 KASSERT(vp->v_type != VFIFO || (kn->kn_filter != EVFILT_READ && 6530 kn->kn_filter != EVFILT_WRITE), 6531 ("READ/WRITE filter on a FIFO leaked through")); 6532 switch (kn->kn_filter) { 6533 case EVFILT_READ: 6534 kn->kn_fop = &vfsread_filtops; 6535 break; 6536 case EVFILT_WRITE: 6537 kn->kn_fop = &vfswrite_filtops; 6538 break; 6539 case EVFILT_VNODE: 6540 kn->kn_fop = &vfsvnode_filtops; 6541 break; 6542 default: 6543 return (EINVAL); 6544 } 6545 6546 kn->kn_hook = (caddr_t)vp; 6547 6548 v_addpollinfo(vp); 6549 if (vp->v_pollinfo == NULL) 6550 return (ENOMEM); 6551 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 6552 vhold(vp); 6553 knlist_add(knl, kn, 0); 6554 6555 return (0); 6556 } 6557 6558 /* 6559 * Detach knote from vnode 6560 */ 6561 static void 6562 filt_vfsdetach(struct knote *kn) 6563 { 6564 struct vnode *vp = (struct vnode *)kn->kn_hook; 6565 6566 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 6567 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 6568 vdrop(vp); 6569 } 6570 6571 /*ARGSUSED*/ 6572 static int 6573 filt_vfsread(struct knote *kn, long hint) 6574 { 6575 struct vnode *vp = (struct vnode *)kn->kn_hook; 6576 off_t size; 6577 int res; 6578 6579 /* 6580 * filesystem is gone, so set the EOF flag and schedule 6581 * the knote for deletion. 6582 */ 6583 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6584 VI_LOCK(vp); 6585 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6586 VI_UNLOCK(vp); 6587 return (1); 6588 } 6589 6590 if (vn_getsize_locked(vp, &size, curthread->td_ucred) != 0) 6591 return (0); 6592 6593 VI_LOCK(vp); 6594 kn->kn_data = size - kn->kn_fp->f_offset; 6595 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 6596 VI_UNLOCK(vp); 6597 return (res); 6598 } 6599 6600 /*ARGSUSED*/ 6601 static int 6602 filt_vfswrite(struct knote *kn, long hint) 6603 { 6604 struct vnode *vp = (struct vnode *)kn->kn_hook; 6605 6606 VI_LOCK(vp); 6607 6608 /* 6609 * filesystem is gone, so set the EOF flag and schedule 6610 * the knote for deletion. 6611 */ 6612 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 6613 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 6614 6615 kn->kn_data = 0; 6616 VI_UNLOCK(vp); 6617 return (1); 6618 } 6619 6620 static int 6621 filt_vfsvnode(struct knote *kn, long hint) 6622 { 6623 struct vnode *vp = (struct vnode *)kn->kn_hook; 6624 int res; 6625 6626 VI_LOCK(vp); 6627 if (kn->kn_sfflags & hint) 6628 kn->kn_fflags |= hint; 6629 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 6630 kn->kn_flags |= EV_EOF; 6631 VI_UNLOCK(vp); 6632 return (1); 6633 } 6634 res = (kn->kn_fflags != 0); 6635 VI_UNLOCK(vp); 6636 return (res); 6637 } 6638 6639 int 6640 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 6641 { 6642 int error; 6643 6644 if (dp->d_reclen > ap->a_uio->uio_resid) 6645 return (ENAMETOOLONG); 6646 error = uiomove(dp, dp->d_reclen, ap->a_uio); 6647 if (error) { 6648 if (ap->a_ncookies != NULL) { 6649 if (ap->a_cookies != NULL) 6650 free(ap->a_cookies, M_TEMP); 6651 ap->a_cookies = NULL; 6652 *ap->a_ncookies = 0; 6653 } 6654 return (error); 6655 } 6656 if (ap->a_ncookies == NULL) 6657 return (0); 6658 6659 KASSERT(ap->a_cookies, 6660 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 6661 6662 *ap->a_cookies = realloc(*ap->a_cookies, 6663 (*ap->a_ncookies + 1) * sizeof(uint64_t), M_TEMP, M_WAITOK | M_ZERO); 6664 (*ap->a_cookies)[*ap->a_ncookies] = off; 6665 *ap->a_ncookies += 1; 6666 return (0); 6667 } 6668 6669 /* 6670 * The purpose of this routine is to remove granularity from accmode_t, 6671 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 6672 * VADMIN and VAPPEND. 6673 * 6674 * If it returns 0, the caller is supposed to continue with the usual 6675 * access checks using 'accmode' as modified by this routine. If it 6676 * returns nonzero value, the caller is supposed to return that value 6677 * as errno. 6678 * 6679 * Note that after this routine runs, accmode may be zero. 6680 */ 6681 int 6682 vfs_unixify_accmode(accmode_t *accmode) 6683 { 6684 /* 6685 * There is no way to specify explicit "deny" rule using 6686 * file mode or POSIX.1e ACLs. 6687 */ 6688 if (*accmode & VEXPLICIT_DENY) { 6689 *accmode = 0; 6690 return (0); 6691 } 6692 6693 /* 6694 * None of these can be translated into usual access bits. 6695 * Also, the common case for NFSv4 ACLs is to not contain 6696 * either of these bits. Caller should check for VWRITE 6697 * on the containing directory instead. 6698 */ 6699 if (*accmode & (VDELETE_CHILD | VDELETE)) 6700 return (EPERM); 6701 6702 if (*accmode & VADMIN_PERMS) { 6703 *accmode &= ~VADMIN_PERMS; 6704 *accmode |= VADMIN; 6705 } 6706 6707 /* 6708 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 6709 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 6710 */ 6711 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 6712 6713 return (0); 6714 } 6715 6716 /* 6717 * Clear out a doomed vnode (if any) and replace it with a new one as long 6718 * as the fs is not being unmounted. Return the root vnode to the caller. 6719 */ 6720 static int __noinline 6721 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 6722 { 6723 struct vnode *vp; 6724 int error; 6725 6726 restart: 6727 if (mp->mnt_rootvnode != NULL) { 6728 MNT_ILOCK(mp); 6729 vp = mp->mnt_rootvnode; 6730 if (vp != NULL) { 6731 if (!VN_IS_DOOMED(vp)) { 6732 vrefact(vp); 6733 MNT_IUNLOCK(mp); 6734 error = vn_lock(vp, flags); 6735 if (error == 0) { 6736 *vpp = vp; 6737 return (0); 6738 } 6739 vrele(vp); 6740 goto restart; 6741 } 6742 /* 6743 * Clear the old one. 6744 */ 6745 mp->mnt_rootvnode = NULL; 6746 } 6747 MNT_IUNLOCK(mp); 6748 if (vp != NULL) { 6749 vfs_op_barrier_wait(mp); 6750 vrele(vp); 6751 } 6752 } 6753 error = VFS_CACHEDROOT(mp, flags, vpp); 6754 if (error != 0) 6755 return (error); 6756 if (mp->mnt_vfs_ops == 0) { 6757 MNT_ILOCK(mp); 6758 if (mp->mnt_vfs_ops != 0) { 6759 MNT_IUNLOCK(mp); 6760 return (0); 6761 } 6762 if (mp->mnt_rootvnode == NULL) { 6763 vrefact(*vpp); 6764 mp->mnt_rootvnode = *vpp; 6765 } else { 6766 if (mp->mnt_rootvnode != *vpp) { 6767 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 6768 panic("%s: mismatch between vnode returned " 6769 " by VFS_CACHEDROOT and the one cached " 6770 " (%p != %p)", 6771 __func__, *vpp, mp->mnt_rootvnode); 6772 } 6773 } 6774 } 6775 MNT_IUNLOCK(mp); 6776 } 6777 return (0); 6778 } 6779 6780 int 6781 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 6782 { 6783 struct mount_pcpu *mpcpu; 6784 struct vnode *vp; 6785 int error; 6786 6787 if (!vfs_op_thread_enter(mp, mpcpu)) 6788 return (vfs_cache_root_fallback(mp, flags, vpp)); 6789 vp = atomic_load_ptr(&mp->mnt_rootvnode); 6790 if (vp == NULL || VN_IS_DOOMED(vp)) { 6791 vfs_op_thread_exit(mp, mpcpu); 6792 return (vfs_cache_root_fallback(mp, flags, vpp)); 6793 } 6794 vrefact(vp); 6795 vfs_op_thread_exit(mp, mpcpu); 6796 error = vn_lock(vp, flags); 6797 if (error != 0) { 6798 vrele(vp); 6799 return (vfs_cache_root_fallback(mp, flags, vpp)); 6800 } 6801 *vpp = vp; 6802 return (0); 6803 } 6804 6805 struct vnode * 6806 vfs_cache_root_clear(struct mount *mp) 6807 { 6808 struct vnode *vp; 6809 6810 /* 6811 * ops > 0 guarantees there is nobody who can see this vnode 6812 */ 6813 MPASS(mp->mnt_vfs_ops > 0); 6814 vp = mp->mnt_rootvnode; 6815 if (vp != NULL) 6816 vn_seqc_write_begin(vp); 6817 mp->mnt_rootvnode = NULL; 6818 return (vp); 6819 } 6820 6821 void 6822 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 6823 { 6824 6825 MPASS(mp->mnt_vfs_ops > 0); 6826 vrefact(vp); 6827 mp->mnt_rootvnode = vp; 6828 } 6829 6830 /* 6831 * These are helper functions for filesystems to traverse all 6832 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 6833 * 6834 * This interface replaces MNT_VNODE_FOREACH. 6835 */ 6836 6837 struct vnode * 6838 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 6839 { 6840 struct vnode *vp; 6841 6842 maybe_yield(); 6843 MNT_ILOCK(mp); 6844 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6845 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 6846 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 6847 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6848 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6849 continue; 6850 VI_LOCK(vp); 6851 if (VN_IS_DOOMED(vp)) { 6852 VI_UNLOCK(vp); 6853 continue; 6854 } 6855 break; 6856 } 6857 if (vp == NULL) { 6858 __mnt_vnode_markerfree_all(mvp, mp); 6859 /* MNT_IUNLOCK(mp); -- done in above function */ 6860 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 6861 return (NULL); 6862 } 6863 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6864 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6865 MNT_IUNLOCK(mp); 6866 return (vp); 6867 } 6868 6869 struct vnode * 6870 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 6871 { 6872 struct vnode *vp; 6873 6874 *mvp = vn_alloc_marker(mp); 6875 MNT_ILOCK(mp); 6876 MNT_REF(mp); 6877 6878 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 6879 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 6880 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 6881 continue; 6882 VI_LOCK(vp); 6883 if (VN_IS_DOOMED(vp)) { 6884 VI_UNLOCK(vp); 6885 continue; 6886 } 6887 break; 6888 } 6889 if (vp == NULL) { 6890 MNT_REL(mp); 6891 MNT_IUNLOCK(mp); 6892 vn_free_marker(*mvp); 6893 *mvp = NULL; 6894 return (NULL); 6895 } 6896 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 6897 MNT_IUNLOCK(mp); 6898 return (vp); 6899 } 6900 6901 void 6902 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 6903 { 6904 6905 if (*mvp == NULL) { 6906 MNT_IUNLOCK(mp); 6907 return; 6908 } 6909 6910 mtx_assert(MNT_MTX(mp), MA_OWNED); 6911 6912 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6913 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 6914 MNT_REL(mp); 6915 MNT_IUNLOCK(mp); 6916 vn_free_marker(*mvp); 6917 *mvp = NULL; 6918 } 6919 6920 /* 6921 * These are helper functions for filesystems to traverse their 6922 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h 6923 */ 6924 static void 6925 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 6926 { 6927 6928 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6929 6930 MNT_ILOCK(mp); 6931 MNT_REL(mp); 6932 MNT_IUNLOCK(mp); 6933 vn_free_marker(*mvp); 6934 *mvp = NULL; 6935 } 6936 6937 /* 6938 * Relock the mp mount vnode list lock with the vp vnode interlock in the 6939 * conventional lock order during mnt_vnode_next_lazy iteration. 6940 * 6941 * On entry, the mount vnode list lock is held and the vnode interlock is not. 6942 * The list lock is dropped and reacquired. On success, both locks are held. 6943 * On failure, the mount vnode list lock is held but the vnode interlock is 6944 * not, and the procedure may have yielded. 6945 */ 6946 static bool 6947 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp, 6948 struct vnode *vp) 6949 { 6950 6951 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 6952 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp, 6953 ("%s: bad marker", __func__)); 6954 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 6955 ("%s: inappropriate vnode", __func__)); 6956 ASSERT_VI_UNLOCKED(vp, __func__); 6957 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6958 6959 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist); 6960 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist); 6961 6962 /* 6963 * Note we may be racing against vdrop which transitioned the hold 6964 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine, 6965 * if we are the only user after we get the interlock we will just 6966 * vdrop. 6967 */ 6968 vhold(vp); 6969 mtx_unlock(&mp->mnt_listmtx); 6970 VI_LOCK(vp); 6971 if (VN_IS_DOOMED(vp)) { 6972 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp); 6973 goto out_lost; 6974 } 6975 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp); 6976 /* 6977 * There is nothing to do if we are the last user. 6978 */ 6979 if (!refcount_release_if_not_last(&vp->v_holdcnt)) 6980 goto out_lost; 6981 mtx_lock(&mp->mnt_listmtx); 6982 return (true); 6983 out_lost: 6984 vdropl(vp); 6985 maybe_yield(); 6986 mtx_lock(&mp->mnt_listmtx); 6987 return (false); 6988 } 6989 6990 static struct vnode * 6991 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 6992 void *cbarg) 6993 { 6994 struct vnode *vp; 6995 6996 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 6997 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 6998 restart: 6999 vp = TAILQ_NEXT(*mvp, v_lazylist); 7000 while (vp != NULL) { 7001 if (vp->v_type == VMARKER) { 7002 vp = TAILQ_NEXT(vp, v_lazylist); 7003 continue; 7004 } 7005 /* 7006 * See if we want to process the vnode. Note we may encounter a 7007 * long string of vnodes we don't care about and hog the list 7008 * as a result. Check for it and requeue the marker. 7009 */ 7010 VNPASS(!VN_IS_DOOMED(vp), vp); 7011 if (!cb(vp, cbarg)) { 7012 if (!should_yield()) { 7013 vp = TAILQ_NEXT(vp, v_lazylist); 7014 continue; 7015 } 7016 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, 7017 v_lazylist); 7018 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, 7019 v_lazylist); 7020 mtx_unlock(&mp->mnt_listmtx); 7021 kern_yield(PRI_USER); 7022 mtx_lock(&mp->mnt_listmtx); 7023 goto restart; 7024 } 7025 /* 7026 * Try-lock because this is the wrong lock order. 7027 */ 7028 if (!VI_TRYLOCK(vp) && 7029 !mnt_vnode_next_lazy_relock(*mvp, mp, vp)) 7030 goto restart; 7031 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 7032 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 7033 ("alien vnode on the lazy list %p %p", vp, mp)); 7034 VNPASS(vp->v_mount == mp, vp); 7035 VNPASS(!VN_IS_DOOMED(vp), vp); 7036 break; 7037 } 7038 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 7039 7040 /* Check if we are done */ 7041 if (vp == NULL) { 7042 mtx_unlock(&mp->mnt_listmtx); 7043 mnt_vnode_markerfree_lazy(mvp, mp); 7044 return (NULL); 7045 } 7046 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist); 7047 mtx_unlock(&mp->mnt_listmtx); 7048 ASSERT_VI_LOCKED(vp, "lazy iter"); 7049 return (vp); 7050 } 7051 7052 struct vnode * 7053 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 7054 void *cbarg) 7055 { 7056 7057 maybe_yield(); 7058 mtx_lock(&mp->mnt_listmtx); 7059 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 7060 } 7061 7062 struct vnode * 7063 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb, 7064 void *cbarg) 7065 { 7066 struct vnode *vp; 7067 7068 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist)) 7069 return (NULL); 7070 7071 *mvp = vn_alloc_marker(mp); 7072 MNT_ILOCK(mp); 7073 MNT_REF(mp); 7074 MNT_IUNLOCK(mp); 7075 7076 mtx_lock(&mp->mnt_listmtx); 7077 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist); 7078 if (vp == NULL) { 7079 mtx_unlock(&mp->mnt_listmtx); 7080 mnt_vnode_markerfree_lazy(mvp, mp); 7081 return (NULL); 7082 } 7083 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist); 7084 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg)); 7085 } 7086 7087 void 7088 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp) 7089 { 7090 7091 if (*mvp == NULL) 7092 return; 7093 7094 mtx_lock(&mp->mnt_listmtx); 7095 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist); 7096 mtx_unlock(&mp->mnt_listmtx); 7097 mnt_vnode_markerfree_lazy(mvp, mp); 7098 } 7099 7100 int 7101 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) 7102 { 7103 7104 if ((cnp->cn_flags & NOEXECCHECK) != 0) { 7105 cnp->cn_flags &= ~NOEXECCHECK; 7106 return (0); 7107 } 7108 7109 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, curthread)); 7110 } 7111 7112 /* 7113 * Do not use this variant unless you have means other than the hold count 7114 * to prevent the vnode from getting freed. 7115 */ 7116 void 7117 vn_seqc_write_begin_locked(struct vnode *vp) 7118 { 7119 7120 ASSERT_VI_LOCKED(vp, __func__); 7121 VNPASS(vp->v_holdcnt > 0, vp); 7122 VNPASS(vp->v_seqc_users >= 0, vp); 7123 vp->v_seqc_users++; 7124 if (vp->v_seqc_users == 1) 7125 seqc_sleepable_write_begin(&vp->v_seqc); 7126 } 7127 7128 void 7129 vn_seqc_write_begin(struct vnode *vp) 7130 { 7131 7132 VI_LOCK(vp); 7133 vn_seqc_write_begin_locked(vp); 7134 VI_UNLOCK(vp); 7135 } 7136 7137 void 7138 vn_seqc_write_end_locked(struct vnode *vp) 7139 { 7140 7141 ASSERT_VI_LOCKED(vp, __func__); 7142 VNPASS(vp->v_seqc_users > 0, vp); 7143 vp->v_seqc_users--; 7144 if (vp->v_seqc_users == 0) 7145 seqc_sleepable_write_end(&vp->v_seqc); 7146 } 7147 7148 void 7149 vn_seqc_write_end(struct vnode *vp) 7150 { 7151 7152 VI_LOCK(vp); 7153 vn_seqc_write_end_locked(vp); 7154 VI_UNLOCK(vp); 7155 } 7156 7157 /* 7158 * Special case handling for allocating and freeing vnodes. 7159 * 7160 * The counter remains unchanged on free so that a doomed vnode will 7161 * keep testing as in modify as long as it is accessible with SMR. 7162 */ 7163 static void 7164 vn_seqc_init(struct vnode *vp) 7165 { 7166 7167 vp->v_seqc = 0; 7168 vp->v_seqc_users = 0; 7169 } 7170 7171 static void 7172 vn_seqc_write_end_free(struct vnode *vp) 7173 { 7174 7175 VNPASS(seqc_in_modify(vp->v_seqc), vp); 7176 VNPASS(vp->v_seqc_users == 1, vp); 7177 } 7178 7179 void 7180 vn_irflag_set_locked(struct vnode *vp, short toset) 7181 { 7182 short flags; 7183 7184 ASSERT_VI_LOCKED(vp, __func__); 7185 flags = vn_irflag_read(vp); 7186 VNASSERT((flags & toset) == 0, vp, 7187 ("%s: some of the passed flags already set (have %d, passed %d)\n", 7188 __func__, flags, toset)); 7189 atomic_store_short(&vp->v_irflag, flags | toset); 7190 } 7191 7192 void 7193 vn_irflag_set(struct vnode *vp, short toset) 7194 { 7195 7196 VI_LOCK(vp); 7197 vn_irflag_set_locked(vp, toset); 7198 VI_UNLOCK(vp); 7199 } 7200 7201 void 7202 vn_irflag_set_cond_locked(struct vnode *vp, short toset) 7203 { 7204 short flags; 7205 7206 ASSERT_VI_LOCKED(vp, __func__); 7207 flags = vn_irflag_read(vp); 7208 atomic_store_short(&vp->v_irflag, flags | toset); 7209 } 7210 7211 void 7212 vn_irflag_set_cond(struct vnode *vp, short toset) 7213 { 7214 7215 VI_LOCK(vp); 7216 vn_irflag_set_cond_locked(vp, toset); 7217 VI_UNLOCK(vp); 7218 } 7219 7220 void 7221 vn_irflag_unset_locked(struct vnode *vp, short tounset) 7222 { 7223 short flags; 7224 7225 ASSERT_VI_LOCKED(vp, __func__); 7226 flags = vn_irflag_read(vp); 7227 VNASSERT((flags & tounset) == tounset, vp, 7228 ("%s: some of the passed flags not set (have %d, passed %d)\n", 7229 __func__, flags, tounset)); 7230 atomic_store_short(&vp->v_irflag, flags & ~tounset); 7231 } 7232 7233 void 7234 vn_irflag_unset(struct vnode *vp, short tounset) 7235 { 7236 7237 VI_LOCK(vp); 7238 vn_irflag_unset_locked(vp, tounset); 7239 VI_UNLOCK(vp); 7240 } 7241 7242 int 7243 vn_getsize_locked(struct vnode *vp, off_t *size, struct ucred *cred) 7244 { 7245 struct vattr vattr; 7246 int error; 7247 7248 ASSERT_VOP_LOCKED(vp, __func__); 7249 error = VOP_GETATTR(vp, &vattr, cred); 7250 if (__predict_true(error == 0)) { 7251 if (vattr.va_size <= OFF_MAX) 7252 *size = vattr.va_size; 7253 else 7254 error = EFBIG; 7255 } 7256 return (error); 7257 } 7258 7259 int 7260 vn_getsize(struct vnode *vp, off_t *size, struct ucred *cred) 7261 { 7262 int error; 7263 7264 VOP_LOCK(vp, LK_SHARED); 7265 error = vn_getsize_locked(vp, size, cred); 7266 VOP_UNLOCK(vp); 7267 return (error); 7268 } 7269 7270 #ifdef INVARIANTS 7271 void 7272 vn_set_state_validate(struct vnode *vp, __enum_uint8(vstate) state) 7273 { 7274 7275 switch (vp->v_state) { 7276 case VSTATE_UNINITIALIZED: 7277 switch (state) { 7278 case VSTATE_CONSTRUCTED: 7279 case VSTATE_DESTROYING: 7280 return; 7281 default: 7282 break; 7283 } 7284 break; 7285 case VSTATE_CONSTRUCTED: 7286 ASSERT_VOP_ELOCKED(vp, __func__); 7287 switch (state) { 7288 case VSTATE_DESTROYING: 7289 return; 7290 default: 7291 break; 7292 } 7293 break; 7294 case VSTATE_DESTROYING: 7295 ASSERT_VOP_ELOCKED(vp, __func__); 7296 switch (state) { 7297 case VSTATE_DEAD: 7298 return; 7299 default: 7300 break; 7301 } 7302 break; 7303 case VSTATE_DEAD: 7304 switch (state) { 7305 case VSTATE_UNINITIALIZED: 7306 return; 7307 default: 7308 break; 7309 } 7310 break; 7311 } 7312 7313 vn_printf(vp, "invalid state transition %d -> %d\n", vp->v_state, state); 7314 panic("invalid state transition %d -> %d\n", vp->v_state, state); 7315 } 7316 #endif 7317