1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 37 */ 38 39 /* 40 * External virtual filesystem routines 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_ddb.h" 47 #include "opt_watchdog.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/bio.h> 52 #include <sys/buf.h> 53 #include <sys/capsicum.h> 54 #include <sys/condvar.h> 55 #include <sys/conf.h> 56 #include <sys/counter.h> 57 #include <sys/dirent.h> 58 #include <sys/event.h> 59 #include <sys/eventhandler.h> 60 #include <sys/extattr.h> 61 #include <sys/file.h> 62 #include <sys/fcntl.h> 63 #include <sys/jail.h> 64 #include <sys/kdb.h> 65 #include <sys/kernel.h> 66 #include <sys/kthread.h> 67 #include <sys/ktr.h> 68 #include <sys/lockf.h> 69 #include <sys/malloc.h> 70 #include <sys/mount.h> 71 #include <sys/namei.h> 72 #include <sys/pctrie.h> 73 #include <sys/priv.h> 74 #include <sys/reboot.h> 75 #include <sys/refcount.h> 76 #include <sys/rwlock.h> 77 #include <sys/sched.h> 78 #include <sys/sleepqueue.h> 79 #include <sys/smp.h> 80 #include <sys/stat.h> 81 #include <sys/sysctl.h> 82 #include <sys/syslog.h> 83 #include <sys/vmmeter.h> 84 #include <sys/vnode.h> 85 #include <sys/watchdog.h> 86 87 #include <machine/stdarg.h> 88 89 #include <security/mac/mac_framework.h> 90 91 #include <vm/vm.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_extern.h> 94 #include <vm/pmap.h> 95 #include <vm/vm_map.h> 96 #include <vm/vm_page.h> 97 #include <vm/vm_kern.h> 98 #include <vm/uma.h> 99 100 #ifdef DDB 101 #include <ddb/ddb.h> 102 #endif 103 104 static void delmntque(struct vnode *vp); 105 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 106 int slpflag, int slptimeo); 107 static void syncer_shutdown(void *arg, int howto); 108 static int vtryrecycle(struct vnode *vp); 109 static void v_init_counters(struct vnode *); 110 static void v_incr_usecount(struct vnode *); 111 static void v_incr_usecount_locked(struct vnode *); 112 static void v_incr_devcount(struct vnode *); 113 static void v_decr_devcount(struct vnode *); 114 static void vgonel(struct vnode *); 115 static void vfs_knllock(void *arg); 116 static void vfs_knlunlock(void *arg); 117 static void vfs_knl_assert_locked(void *arg); 118 static void vfs_knl_assert_unlocked(void *arg); 119 static void vnlru_return_batches(struct vfsops *mnt_op); 120 static void destroy_vpollinfo(struct vpollinfo *vi); 121 122 /* 123 * These fences are intended for cases where some synchronization is 124 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 125 * and v_usecount) updates. Access to v_iflags is generally synchronized 126 * by the interlock, but we have some internal assertions that check vnode 127 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 128 * for now. 129 */ 130 #ifdef INVARIANTS 131 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 132 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 133 #else 134 #define VNODE_REFCOUNT_FENCE_ACQ() 135 #define VNODE_REFCOUNT_FENCE_REL() 136 #endif 137 138 /* 139 * Number of vnodes in existence. Increased whenever getnewvnode() 140 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode. 141 */ 142 static unsigned long numvnodes; 143 144 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 145 "Number of vnodes in existence"); 146 147 static counter_u64_t vnodes_created; 148 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 149 "Number of vnodes created by getnewvnode"); 150 151 static u_long mnt_free_list_batch = 128; 152 SYSCTL_ULONG(_vfs, OID_AUTO, mnt_free_list_batch, CTLFLAG_RW, 153 &mnt_free_list_batch, 0, "Limit of vnodes held on mnt's free list"); 154 155 /* 156 * Conversion tables for conversion from vnode types to inode formats 157 * and back. 158 */ 159 enum vtype iftovt_tab[16] = { 160 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 161 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 162 }; 163 int vttoif_tab[10] = { 164 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 165 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 166 }; 167 168 /* 169 * List of vnodes that are ready for recycling. 170 */ 171 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 172 173 /* 174 * "Free" vnode target. Free vnodes are rarely completely free, but are 175 * just ones that are cheap to recycle. Usually they are for files which 176 * have been stat'd but not read; these usually have inode and namecache 177 * data attached to them. This target is the preferred minimum size of a 178 * sub-cache consisting mostly of such files. The system balances the size 179 * of this sub-cache with its complement to try to prevent either from 180 * thrashing while the other is relatively inactive. The targets express 181 * a preference for the best balance. 182 * 183 * "Above" this target there are 2 further targets (watermarks) related 184 * to recyling of free vnodes. In the best-operating case, the cache is 185 * exactly full, the free list has size between vlowat and vhiwat above the 186 * free target, and recycling from it and normal use maintains this state. 187 * Sometimes the free list is below vlowat or even empty, but this state 188 * is even better for immediate use provided the cache is not full. 189 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 190 * ones) to reach one of these states. The watermarks are currently hard- 191 * coded as 4% and 9% of the available space higher. These and the default 192 * of 25% for wantfreevnodes are too large if the memory size is large. 193 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 194 * whenever vnlru_proc() becomes active. 195 */ 196 static u_long wantfreevnodes; 197 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, 198 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes"); 199 static u_long freevnodes; 200 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 201 &freevnodes, 0, "Number of \"free\" vnodes"); 202 203 static counter_u64_t recycles_count; 204 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 205 "Number of vnodes recycled to meet vnode cache targets"); 206 207 /* 208 * Various variables used for debugging the new implementation of 209 * reassignbuf(). 210 * XXX these are probably of (very) limited utility now. 211 */ 212 static int reassignbufcalls; 213 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, 214 "Number of calls to reassignbuf"); 215 216 static counter_u64_t free_owe_inact; 217 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, 218 "Number of times free vnodes kept on active list due to VFS " 219 "owing inactivation"); 220 221 /* To keep more than one thread at a time from running vfs_getnewfsid */ 222 static struct mtx mntid_mtx; 223 224 /* 225 * Lock for any access to the following: 226 * vnode_free_list 227 * numvnodes 228 * freevnodes 229 */ 230 static struct mtx vnode_free_list_mtx; 231 232 /* Publicly exported FS */ 233 struct nfs_public nfs_pub; 234 235 static uma_zone_t buf_trie_zone; 236 237 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 238 static uma_zone_t vnode_zone; 239 static uma_zone_t vnodepoll_zone; 240 241 /* 242 * The workitem queue. 243 * 244 * It is useful to delay writes of file data and filesystem metadata 245 * for tens of seconds so that quickly created and deleted files need 246 * not waste disk bandwidth being created and removed. To realize this, 247 * we append vnodes to a "workitem" queue. When running with a soft 248 * updates implementation, most pending metadata dependencies should 249 * not wait for more than a few seconds. Thus, mounted on block devices 250 * are delayed only about a half the time that file data is delayed. 251 * Similarly, directory updates are more critical, so are only delayed 252 * about a third the time that file data is delayed. Thus, there are 253 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 254 * one each second (driven off the filesystem syncer process). The 255 * syncer_delayno variable indicates the next queue that is to be processed. 256 * Items that need to be processed soon are placed in this queue: 257 * 258 * syncer_workitem_pending[syncer_delayno] 259 * 260 * A delay of fifteen seconds is done by placing the request fifteen 261 * entries later in the queue: 262 * 263 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 264 * 265 */ 266 static int syncer_delayno; 267 static long syncer_mask; 268 LIST_HEAD(synclist, bufobj); 269 static struct synclist *syncer_workitem_pending; 270 /* 271 * The sync_mtx protects: 272 * bo->bo_synclist 273 * sync_vnode_count 274 * syncer_delayno 275 * syncer_state 276 * syncer_workitem_pending 277 * syncer_worklist_len 278 * rushjob 279 */ 280 static struct mtx sync_mtx; 281 static struct cv sync_wakeup; 282 283 #define SYNCER_MAXDELAY 32 284 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 285 static int syncdelay = 30; /* max time to delay syncing data */ 286 static int filedelay = 30; /* time to delay syncing files */ 287 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 288 "Time to delay syncing files (in seconds)"); 289 static int dirdelay = 29; /* time to delay syncing directories */ 290 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 291 "Time to delay syncing directories (in seconds)"); 292 static int metadelay = 28; /* time to delay syncing metadata */ 293 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 294 "Time to delay syncing metadata (in seconds)"); 295 static int rushjob; /* number of slots to run ASAP */ 296 static int stat_rush_requests; /* number of times I/O speeded up */ 297 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 298 "Number of times I/O speeded up (rush requests)"); 299 300 /* 301 * When shutting down the syncer, run it at four times normal speed. 302 */ 303 #define SYNCER_SHUTDOWN_SPEEDUP 4 304 static int sync_vnode_count; 305 static int syncer_worklist_len; 306 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 307 syncer_state; 308 309 /* Target for maximum number of vnodes. */ 310 int desiredvnodes; 311 static int gapvnodes; /* gap between wanted and desired */ 312 static int vhiwat; /* enough extras after expansion */ 313 static int vlowat; /* minimal extras before expansion */ 314 static int vstir; /* nonzero to stir non-free vnodes */ 315 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 316 317 static int 318 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS) 319 { 320 int error, old_desiredvnodes; 321 322 old_desiredvnodes = desiredvnodes; 323 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0) 324 return (error); 325 if (old_desiredvnodes != desiredvnodes) { 326 wantfreevnodes = desiredvnodes / 4; 327 /* XXX locking seems to be incomplete. */ 328 vfs_hash_changesize(desiredvnodes); 329 cache_changesize(desiredvnodes); 330 } 331 return (0); 332 } 333 334 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 335 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0, 336 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes"); 337 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 338 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 339 static int vnlru_nowhere; 340 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 341 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 342 343 static int 344 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 345 { 346 struct vnode *vp; 347 struct nameidata nd; 348 char *buf; 349 unsigned long ndflags; 350 int error; 351 352 if (req->newptr == NULL) 353 return (EINVAL); 354 if (req->newlen > PATH_MAX) 355 return (E2BIG); 356 357 buf = malloc(PATH_MAX + 1, M_TEMP, M_WAITOK); 358 error = SYSCTL_IN(req, buf, req->newlen); 359 if (error != 0) 360 goto out; 361 362 buf[req->newlen] = '\0'; 363 364 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME; 365 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); 366 if ((error = namei(&nd)) != 0) 367 goto out; 368 vp = nd.ni_vp; 369 370 if ((vp->v_iflag & VI_DOOMED) != 0) { 371 /* 372 * This vnode is being recycled. Return != 0 to let the caller 373 * know that the sysctl had no effect. Return EAGAIN because a 374 * subsequent call will likely succeed (since namei will create 375 * a new vnode if necessary) 376 */ 377 error = EAGAIN; 378 goto putvnode; 379 } 380 381 counter_u64_add(recycles_count, 1); 382 vgone(vp); 383 putvnode: 384 NDFREE(&nd, 0); 385 out: 386 free(buf, M_TEMP); 387 return (error); 388 } 389 390 static int 391 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 392 { 393 struct thread *td = curthread; 394 struct vnode *vp; 395 struct file *fp; 396 int error; 397 int fd; 398 399 if (req->newptr == NULL) 400 return (EBADF); 401 402 error = sysctl_handle_int(oidp, &fd, 0, req); 403 if (error != 0) 404 return (error); 405 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 406 if (error != 0) 407 return (error); 408 vp = fp->f_vnode; 409 410 error = vn_lock(vp, LK_EXCLUSIVE); 411 if (error != 0) 412 goto drop; 413 414 counter_u64_add(recycles_count, 1); 415 vgone(vp); 416 VOP_UNLOCK(vp, 0); 417 drop: 418 fdrop(fp, td); 419 return (error); 420 } 421 422 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 423 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 424 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 425 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 426 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 427 sysctl_ftry_reclaim_vnode, "I", 428 "Try to reclaim a vnode by its file descriptor"); 429 430 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 431 static int vnsz2log; 432 433 /* 434 * Support for the bufobj clean & dirty pctrie. 435 */ 436 static void * 437 buf_trie_alloc(struct pctrie *ptree) 438 { 439 440 return uma_zalloc(buf_trie_zone, M_NOWAIT); 441 } 442 443 static void 444 buf_trie_free(struct pctrie *ptree, void *node) 445 { 446 447 uma_zfree(buf_trie_zone, node); 448 } 449 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 450 451 /* 452 * Initialize the vnode management data structures. 453 * 454 * Reevaluate the following cap on the number of vnodes after the physical 455 * memory size exceeds 512GB. In the limit, as the physical memory size 456 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 457 */ 458 #ifndef MAXVNODES_MAX 459 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */ 460 #endif 461 462 /* 463 * Initialize a vnode as it first enters the zone. 464 */ 465 static int 466 vnode_init(void *mem, int size, int flags) 467 { 468 struct vnode *vp; 469 470 vp = mem; 471 bzero(vp, size); 472 /* 473 * Setup locks. 474 */ 475 vp->v_vnlock = &vp->v_lock; 476 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 477 /* 478 * By default, don't allow shared locks unless filesystems opt-in. 479 */ 480 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 481 LK_NOSHARE | LK_IS_VNODE); 482 /* 483 * Initialize bufobj. 484 */ 485 bufobj_init(&vp->v_bufobj, vp); 486 /* 487 * Initialize namecache. 488 */ 489 LIST_INIT(&vp->v_cache_src); 490 TAILQ_INIT(&vp->v_cache_dst); 491 /* 492 * Initialize rangelocks. 493 */ 494 rangelock_init(&vp->v_rl); 495 return (0); 496 } 497 498 /* 499 * Free a vnode when it is cleared from the zone. 500 */ 501 static void 502 vnode_fini(void *mem, int size) 503 { 504 struct vnode *vp; 505 struct bufobj *bo; 506 507 vp = mem; 508 rangelock_destroy(&vp->v_rl); 509 lockdestroy(vp->v_vnlock); 510 mtx_destroy(&vp->v_interlock); 511 bo = &vp->v_bufobj; 512 rw_destroy(BO_LOCKPTR(bo)); 513 } 514 515 /* 516 * Provide the size of NFS nclnode and NFS fh for calculation of the 517 * vnode memory consumption. The size is specified directly to 518 * eliminate dependency on NFS-private header. 519 * 520 * Other filesystems may use bigger or smaller (like UFS and ZFS) 521 * private inode data, but the NFS-based estimation is ample enough. 522 * Still, we care about differences in the size between 64- and 32-bit 523 * platforms. 524 * 525 * Namecache structure size is heuristically 526 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 527 */ 528 #ifdef _LP64 529 #define NFS_NCLNODE_SZ (528 + 64) 530 #define NC_SZ 148 531 #else 532 #define NFS_NCLNODE_SZ (360 + 32) 533 #define NC_SZ 92 534 #endif 535 536 static void 537 vntblinit(void *dummy __unused) 538 { 539 u_int i; 540 int physvnodes, virtvnodes; 541 542 /* 543 * Desiredvnodes is a function of the physical memory size and the 544 * kernel's heap size. Generally speaking, it scales with the 545 * physical memory size. The ratio of desiredvnodes to the physical 546 * memory size is 1:16 until desiredvnodes exceeds 98,304. 547 * Thereafter, the 548 * marginal ratio of desiredvnodes to the physical memory size is 549 * 1:64. However, desiredvnodes is limited by the kernel's heap 550 * size. The memory required by desiredvnodes vnodes and vm objects 551 * must not exceed 1/10th of the kernel's heap size. 552 */ 553 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 554 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 555 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 556 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 557 desiredvnodes = min(physvnodes, virtvnodes); 558 if (desiredvnodes > MAXVNODES_MAX) { 559 if (bootverbose) 560 printf("Reducing kern.maxvnodes %d -> %d\n", 561 desiredvnodes, MAXVNODES_MAX); 562 desiredvnodes = MAXVNODES_MAX; 563 } 564 wantfreevnodes = desiredvnodes / 4; 565 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 566 TAILQ_INIT(&vnode_free_list); 567 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 568 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 569 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 570 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 571 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 572 /* 573 * Preallocate enough nodes to support one-per buf so that 574 * we can not fail an insert. reassignbuf() callers can not 575 * tolerate the insertion failure. 576 */ 577 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 578 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 579 UMA_ZONE_NOFREE | UMA_ZONE_VM); 580 uma_prealloc(buf_trie_zone, nbuf); 581 582 vnodes_created = counter_u64_alloc(M_WAITOK); 583 recycles_count = counter_u64_alloc(M_WAITOK); 584 free_owe_inact = counter_u64_alloc(M_WAITOK); 585 586 /* 587 * Initialize the filesystem syncer. 588 */ 589 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 590 &syncer_mask); 591 syncer_maxdelay = syncer_mask + 1; 592 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 593 cv_init(&sync_wakeup, "syncer"); 594 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 595 vnsz2log++; 596 vnsz2log--; 597 } 598 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 599 600 601 /* 602 * Mark a mount point as busy. Used to synchronize access and to delay 603 * unmounting. Eventually, mountlist_mtx is not released on failure. 604 * 605 * vfs_busy() is a custom lock, it can block the caller. 606 * vfs_busy() only sleeps if the unmount is active on the mount point. 607 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 608 * vnode belonging to mp. 609 * 610 * Lookup uses vfs_busy() to traverse mount points. 611 * root fs var fs 612 * / vnode lock A / vnode lock (/var) D 613 * /var vnode lock B /log vnode lock(/var/log) E 614 * vfs_busy lock C vfs_busy lock F 615 * 616 * Within each file system, the lock order is C->A->B and F->D->E. 617 * 618 * When traversing across mounts, the system follows that lock order: 619 * 620 * C->A->B 621 * | 622 * +->F->D->E 623 * 624 * The lookup() process for namei("/var") illustrates the process: 625 * VOP_LOOKUP() obtains B while A is held 626 * vfs_busy() obtains a shared lock on F while A and B are held 627 * vput() releases lock on B 628 * vput() releases lock on A 629 * VFS_ROOT() obtains lock on D while shared lock on F is held 630 * vfs_unbusy() releases shared lock on F 631 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 632 * Attempt to lock A (instead of vp_crossmp) while D is held would 633 * violate the global order, causing deadlocks. 634 * 635 * dounmount() locks B while F is drained. 636 */ 637 int 638 vfs_busy(struct mount *mp, int flags) 639 { 640 641 MPASS((flags & ~MBF_MASK) == 0); 642 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 643 644 MNT_ILOCK(mp); 645 MNT_REF(mp); 646 /* 647 * If mount point is currently being unmounted, sleep until the 648 * mount point fate is decided. If thread doing the unmounting fails, 649 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 650 * that this mount point has survived the unmount attempt and vfs_busy 651 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 652 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 653 * about to be really destroyed. vfs_busy needs to release its 654 * reference on the mount point in this case and return with ENOENT, 655 * telling the caller that mount mount it tried to busy is no longer 656 * valid. 657 */ 658 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 659 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 660 MNT_REL(mp); 661 MNT_IUNLOCK(mp); 662 CTR1(KTR_VFS, "%s: failed busying before sleeping", 663 __func__); 664 return (ENOENT); 665 } 666 if (flags & MBF_MNTLSTLOCK) 667 mtx_unlock(&mountlist_mtx); 668 mp->mnt_kern_flag |= MNTK_MWAIT; 669 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 670 if (flags & MBF_MNTLSTLOCK) 671 mtx_lock(&mountlist_mtx); 672 MNT_ILOCK(mp); 673 } 674 if (flags & MBF_MNTLSTLOCK) 675 mtx_unlock(&mountlist_mtx); 676 mp->mnt_lockref++; 677 MNT_IUNLOCK(mp); 678 return (0); 679 } 680 681 /* 682 * Free a busy filesystem. 683 */ 684 void 685 vfs_unbusy(struct mount *mp) 686 { 687 688 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 689 MNT_ILOCK(mp); 690 MNT_REL(mp); 691 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref")); 692 mp->mnt_lockref--; 693 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 694 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 695 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 696 mp->mnt_kern_flag &= ~MNTK_DRAINING; 697 wakeup(&mp->mnt_lockref); 698 } 699 MNT_IUNLOCK(mp); 700 } 701 702 /* 703 * Lookup a mount point by filesystem identifier. 704 */ 705 struct mount * 706 vfs_getvfs(fsid_t *fsid) 707 { 708 struct mount *mp; 709 710 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 711 mtx_lock(&mountlist_mtx); 712 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 713 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 714 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 715 vfs_ref(mp); 716 mtx_unlock(&mountlist_mtx); 717 return (mp); 718 } 719 } 720 mtx_unlock(&mountlist_mtx); 721 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 722 return ((struct mount *) 0); 723 } 724 725 /* 726 * Lookup a mount point by filesystem identifier, busying it before 727 * returning. 728 * 729 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 730 * cache for popular filesystem identifiers. The cache is lockess, using 731 * the fact that struct mount's are never freed. In worst case we may 732 * get pointer to unmounted or even different filesystem, so we have to 733 * check what we got, and go slow way if so. 734 */ 735 struct mount * 736 vfs_busyfs(fsid_t *fsid) 737 { 738 #define FSID_CACHE_SIZE 256 739 typedef struct mount * volatile vmp_t; 740 static vmp_t cache[FSID_CACHE_SIZE]; 741 struct mount *mp; 742 int error; 743 uint32_t hash; 744 745 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 746 hash = fsid->val[0] ^ fsid->val[1]; 747 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 748 mp = cache[hash]; 749 if (mp == NULL || 750 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 751 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 752 goto slow; 753 if (vfs_busy(mp, 0) != 0) { 754 cache[hash] = NULL; 755 goto slow; 756 } 757 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 758 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 759 return (mp); 760 else 761 vfs_unbusy(mp); 762 763 slow: 764 mtx_lock(&mountlist_mtx); 765 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 766 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 767 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 768 error = vfs_busy(mp, MBF_MNTLSTLOCK); 769 if (error) { 770 cache[hash] = NULL; 771 mtx_unlock(&mountlist_mtx); 772 return (NULL); 773 } 774 cache[hash] = mp; 775 return (mp); 776 } 777 } 778 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 779 mtx_unlock(&mountlist_mtx); 780 return ((struct mount *) 0); 781 } 782 783 /* 784 * Check if a user can access privileged mount options. 785 */ 786 int 787 vfs_suser(struct mount *mp, struct thread *td) 788 { 789 int error; 790 791 if (jailed(td->td_ucred)) { 792 /* 793 * If the jail of the calling thread lacks permission for 794 * this type of file system, deny immediately. 795 */ 796 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 797 return (EPERM); 798 799 /* 800 * If the file system was mounted outside the jail of the 801 * calling thread, deny immediately. 802 */ 803 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 804 return (EPERM); 805 } 806 807 /* 808 * If file system supports delegated administration, we don't check 809 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 810 * by the file system itself. 811 * If this is not the user that did original mount, we check for 812 * the PRIV_VFS_MOUNT_OWNER privilege. 813 */ 814 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 815 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 816 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 817 return (error); 818 } 819 return (0); 820 } 821 822 /* 823 * Get a new unique fsid. Try to make its val[0] unique, since this value 824 * will be used to create fake device numbers for stat(). Also try (but 825 * not so hard) make its val[0] unique mod 2^16, since some emulators only 826 * support 16-bit device numbers. We end up with unique val[0]'s for the 827 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 828 * 829 * Keep in mind that several mounts may be running in parallel. Starting 830 * the search one past where the previous search terminated is both a 831 * micro-optimization and a defense against returning the same fsid to 832 * different mounts. 833 */ 834 void 835 vfs_getnewfsid(struct mount *mp) 836 { 837 static uint16_t mntid_base; 838 struct mount *nmp; 839 fsid_t tfsid; 840 int mtype; 841 842 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 843 mtx_lock(&mntid_mtx); 844 mtype = mp->mnt_vfc->vfc_typenum; 845 tfsid.val[1] = mtype; 846 mtype = (mtype & 0xFF) << 24; 847 for (;;) { 848 tfsid.val[0] = makedev(255, 849 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 850 mntid_base++; 851 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 852 break; 853 vfs_rel(nmp); 854 } 855 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 856 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 857 mtx_unlock(&mntid_mtx); 858 } 859 860 /* 861 * Knob to control the precision of file timestamps: 862 * 863 * 0 = seconds only; nanoseconds zeroed. 864 * 1 = seconds and nanoseconds, accurate within 1/HZ. 865 * 2 = seconds and nanoseconds, truncated to microseconds. 866 * >=3 = seconds and nanoseconds, maximum precision. 867 */ 868 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 869 870 static int timestamp_precision = TSP_USEC; 871 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 872 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 873 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 874 "3+: sec + ns (max. precision))"); 875 876 /* 877 * Get a current timestamp. 878 */ 879 void 880 vfs_timestamp(struct timespec *tsp) 881 { 882 struct timeval tv; 883 884 switch (timestamp_precision) { 885 case TSP_SEC: 886 tsp->tv_sec = time_second; 887 tsp->tv_nsec = 0; 888 break; 889 case TSP_HZ: 890 getnanotime(tsp); 891 break; 892 case TSP_USEC: 893 microtime(&tv); 894 TIMEVAL_TO_TIMESPEC(&tv, tsp); 895 break; 896 case TSP_NSEC: 897 default: 898 nanotime(tsp); 899 break; 900 } 901 } 902 903 /* 904 * Set vnode attributes to VNOVAL 905 */ 906 void 907 vattr_null(struct vattr *vap) 908 { 909 910 vap->va_type = VNON; 911 vap->va_size = VNOVAL; 912 vap->va_bytes = VNOVAL; 913 vap->va_mode = VNOVAL; 914 vap->va_nlink = VNOVAL; 915 vap->va_uid = VNOVAL; 916 vap->va_gid = VNOVAL; 917 vap->va_fsid = VNOVAL; 918 vap->va_fileid = VNOVAL; 919 vap->va_blocksize = VNOVAL; 920 vap->va_rdev = VNOVAL; 921 vap->va_atime.tv_sec = VNOVAL; 922 vap->va_atime.tv_nsec = VNOVAL; 923 vap->va_mtime.tv_sec = VNOVAL; 924 vap->va_mtime.tv_nsec = VNOVAL; 925 vap->va_ctime.tv_sec = VNOVAL; 926 vap->va_ctime.tv_nsec = VNOVAL; 927 vap->va_birthtime.tv_sec = VNOVAL; 928 vap->va_birthtime.tv_nsec = VNOVAL; 929 vap->va_flags = VNOVAL; 930 vap->va_gen = VNOVAL; 931 vap->va_vaflags = 0; 932 } 933 934 /* 935 * This routine is called when we have too many vnodes. It attempts 936 * to free <count> vnodes and will potentially free vnodes that still 937 * have VM backing store (VM backing store is typically the cause 938 * of a vnode blowout so we want to do this). Therefore, this operation 939 * is not considered cheap. 940 * 941 * A number of conditions may prevent a vnode from being reclaimed. 942 * the buffer cache may have references on the vnode, a directory 943 * vnode may still have references due to the namei cache representing 944 * underlying files, or the vnode may be in active use. It is not 945 * desirable to reuse such vnodes. These conditions may cause the 946 * number of vnodes to reach some minimum value regardless of what 947 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 948 */ 949 static int 950 vlrureclaim(struct mount *mp, int reclaim_nc_src, int trigger) 951 { 952 struct vnode *vp; 953 int count, done, target; 954 955 done = 0; 956 vn_start_write(NULL, &mp, V_WAIT); 957 MNT_ILOCK(mp); 958 count = mp->mnt_nvnodelistsize; 959 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1); 960 target = target / 10 + 1; 961 while (count != 0 && done < target) { 962 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 963 while (vp != NULL && vp->v_type == VMARKER) 964 vp = TAILQ_NEXT(vp, v_nmntvnodes); 965 if (vp == NULL) 966 break; 967 /* 968 * XXX LRU is completely broken for non-free vnodes. First 969 * by calling here in mountpoint order, then by moving 970 * unselected vnodes to the end here, and most grossly by 971 * removing the vlruvp() function that was supposed to 972 * maintain the order. (This function was born broken 973 * since syncer problems prevented it doing anything.) The 974 * order is closer to LRC (C = Created). 975 * 976 * LRU reclaiming of vnodes seems to have last worked in 977 * FreeBSD-3 where LRU wasn't mentioned under any spelling. 978 * Then there was no hold count, and inactive vnodes were 979 * simply put on the free list in LRU order. The separate 980 * lists also break LRU. We prefer to reclaim from the 981 * free list for technical reasons. This tends to thrash 982 * the free list to keep very unrecently used held vnodes. 983 * The problem is mitigated by keeping the free list large. 984 */ 985 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 986 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 987 --count; 988 if (!VI_TRYLOCK(vp)) 989 goto next_iter; 990 /* 991 * If it's been deconstructed already, it's still 992 * referenced, or it exceeds the trigger, skip it. 993 * Also skip free vnodes. We are trying to make space 994 * to expand the free list, not reduce it. 995 */ 996 if (vp->v_usecount || 997 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 998 ((vp->v_iflag & VI_FREE) != 0) || 999 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 1000 vp->v_object->resident_page_count > trigger)) { 1001 VI_UNLOCK(vp); 1002 goto next_iter; 1003 } 1004 MNT_IUNLOCK(mp); 1005 vholdl(vp); 1006 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 1007 vdrop(vp); 1008 goto next_iter_mntunlocked; 1009 } 1010 VI_LOCK(vp); 1011 /* 1012 * v_usecount may have been bumped after VOP_LOCK() dropped 1013 * the vnode interlock and before it was locked again. 1014 * 1015 * It is not necessary to recheck VI_DOOMED because it can 1016 * only be set by another thread that holds both the vnode 1017 * lock and vnode interlock. If another thread has the 1018 * vnode lock before we get to VOP_LOCK() and obtains the 1019 * vnode interlock after VOP_LOCK() drops the vnode 1020 * interlock, the other thread will be unable to drop the 1021 * vnode lock before our VOP_LOCK() call fails. 1022 */ 1023 if (vp->v_usecount || 1024 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1025 (vp->v_iflag & VI_FREE) != 0 || 1026 (vp->v_object != NULL && 1027 vp->v_object->resident_page_count > trigger)) { 1028 VOP_UNLOCK(vp, LK_INTERLOCK); 1029 vdrop(vp); 1030 goto next_iter_mntunlocked; 1031 } 1032 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 1033 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 1034 counter_u64_add(recycles_count, 1); 1035 vgonel(vp); 1036 VOP_UNLOCK(vp, 0); 1037 vdropl(vp); 1038 done++; 1039 next_iter_mntunlocked: 1040 if (!should_yield()) 1041 goto relock_mnt; 1042 goto yield; 1043 next_iter: 1044 if (!should_yield()) 1045 continue; 1046 MNT_IUNLOCK(mp); 1047 yield: 1048 kern_yield(PRI_USER); 1049 relock_mnt: 1050 MNT_ILOCK(mp); 1051 } 1052 MNT_IUNLOCK(mp); 1053 vn_finished_write(mp); 1054 return done; 1055 } 1056 1057 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1058 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1059 0, 1060 "limit on vnode free requests per call to the vnlru_free routine"); 1061 1062 /* 1063 * Attempt to reduce the free list by the requested amount. 1064 */ 1065 static void 1066 vnlru_free_locked(int count, struct vfsops *mnt_op) 1067 { 1068 struct vnode *vp; 1069 struct mount *mp; 1070 bool tried_batches; 1071 1072 tried_batches = false; 1073 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1074 if (count > max_vnlru_free) 1075 count = max_vnlru_free; 1076 for (; count > 0; count--) { 1077 vp = TAILQ_FIRST(&vnode_free_list); 1078 /* 1079 * The list can be modified while the free_list_mtx 1080 * has been dropped and vp could be NULL here. 1081 */ 1082 if (vp == NULL) { 1083 if (tried_batches) 1084 break; 1085 mtx_unlock(&vnode_free_list_mtx); 1086 vnlru_return_batches(mnt_op); 1087 tried_batches = true; 1088 mtx_lock(&vnode_free_list_mtx); 1089 continue; 1090 } 1091 1092 VNASSERT(vp->v_op != NULL, vp, 1093 ("vnlru_free: vnode already reclaimed.")); 1094 KASSERT((vp->v_iflag & VI_FREE) != 0, 1095 ("Removing vnode not on freelist")); 1096 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1097 ("Mangling active vnode")); 1098 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 1099 1100 /* 1101 * Don't recycle if our vnode is from different type 1102 * of mount point. Note that mp is type-safe, the 1103 * check does not reach unmapped address even if 1104 * vnode is reclaimed. 1105 * Don't recycle if we can't get the interlock without 1106 * blocking. 1107 */ 1108 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL && 1109 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1110 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist); 1111 continue; 1112 } 1113 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0, 1114 vp, ("vp inconsistent on freelist")); 1115 1116 /* 1117 * The clear of VI_FREE prevents activation of the 1118 * vnode. There is no sense in putting the vnode on 1119 * the mount point active list, only to remove it 1120 * later during recycling. Inline the relevant part 1121 * of vholdl(), to avoid triggering assertions or 1122 * activating. 1123 */ 1124 freevnodes--; 1125 vp->v_iflag &= ~VI_FREE; 1126 VNODE_REFCOUNT_FENCE_REL(); 1127 refcount_acquire(&vp->v_holdcnt); 1128 1129 mtx_unlock(&vnode_free_list_mtx); 1130 VI_UNLOCK(vp); 1131 vtryrecycle(vp); 1132 /* 1133 * If the recycled succeeded this vdrop will actually free 1134 * the vnode. If not it will simply place it back on 1135 * the free list. 1136 */ 1137 vdrop(vp); 1138 mtx_lock(&vnode_free_list_mtx); 1139 } 1140 } 1141 1142 void 1143 vnlru_free(int count, struct vfsops *mnt_op) 1144 { 1145 1146 mtx_lock(&vnode_free_list_mtx); 1147 vnlru_free_locked(count, mnt_op); 1148 mtx_unlock(&vnode_free_list_mtx); 1149 } 1150 1151 1152 /* XXX some names and initialization are bad for limits and watermarks. */ 1153 static int 1154 vspace(void) 1155 { 1156 int space; 1157 1158 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1159 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1160 vlowat = vhiwat / 2; 1161 if (numvnodes > desiredvnodes) 1162 return (0); 1163 space = desiredvnodes - numvnodes; 1164 if (freevnodes > wantfreevnodes) 1165 space += freevnodes - wantfreevnodes; 1166 return (space); 1167 } 1168 1169 static void 1170 vnlru_return_batch_locked(struct mount *mp) 1171 { 1172 struct vnode *vp; 1173 1174 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 1175 1176 if (mp->mnt_tmpfreevnodelistsize == 0) 1177 return; 1178 1179 TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) { 1180 VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp, 1181 ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist")); 1182 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 1183 } 1184 mtx_lock(&vnode_free_list_mtx); 1185 TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist); 1186 freevnodes += mp->mnt_tmpfreevnodelistsize; 1187 mtx_unlock(&vnode_free_list_mtx); 1188 mp->mnt_tmpfreevnodelistsize = 0; 1189 } 1190 1191 static void 1192 vnlru_return_batch(struct mount *mp) 1193 { 1194 1195 mtx_lock(&mp->mnt_listmtx); 1196 vnlru_return_batch_locked(mp); 1197 mtx_unlock(&mp->mnt_listmtx); 1198 } 1199 1200 static void 1201 vnlru_return_batches(struct vfsops *mnt_op) 1202 { 1203 struct mount *mp, *nmp; 1204 bool need_unbusy; 1205 1206 mtx_lock(&mountlist_mtx); 1207 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1208 need_unbusy = false; 1209 if (mnt_op != NULL && mp->mnt_op != mnt_op) 1210 goto next; 1211 if (mp->mnt_tmpfreevnodelistsize == 0) 1212 goto next; 1213 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) { 1214 vnlru_return_batch(mp); 1215 need_unbusy = true; 1216 mtx_lock(&mountlist_mtx); 1217 } 1218 next: 1219 nmp = TAILQ_NEXT(mp, mnt_list); 1220 if (need_unbusy) 1221 vfs_unbusy(mp); 1222 } 1223 mtx_unlock(&mountlist_mtx); 1224 } 1225 1226 /* 1227 * Attempt to recycle vnodes in a context that is always safe to block. 1228 * Calling vlrurecycle() from the bowels of filesystem code has some 1229 * interesting deadlock problems. 1230 */ 1231 static struct proc *vnlruproc; 1232 static int vnlruproc_sig; 1233 1234 static void 1235 vnlru_proc(void) 1236 { 1237 struct mount *mp, *nmp; 1238 unsigned long onumvnodes; 1239 int done, force, reclaim_nc_src, trigger, usevnodes; 1240 1241 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1242 SHUTDOWN_PRI_FIRST); 1243 1244 force = 0; 1245 for (;;) { 1246 kproc_suspend_check(vnlruproc); 1247 mtx_lock(&vnode_free_list_mtx); 1248 /* 1249 * If numvnodes is too large (due to desiredvnodes being 1250 * adjusted using its sysctl, or emergency growth), first 1251 * try to reduce it by discarding from the free list. 1252 */ 1253 if (numvnodes > desiredvnodes) 1254 vnlru_free_locked(numvnodes - desiredvnodes, NULL); 1255 /* 1256 * Sleep if the vnode cache is in a good state. This is 1257 * when it is not over-full and has space for about a 4% 1258 * or 9% expansion (by growing its size or inexcessively 1259 * reducing its free list). Otherwise, try to reclaim 1260 * space for a 10% expansion. 1261 */ 1262 if (vstir && force == 0) { 1263 force = 1; 1264 vstir = 0; 1265 } 1266 if (vspace() >= vlowat && force == 0) { 1267 vnlruproc_sig = 0; 1268 wakeup(&vnlruproc_sig); 1269 msleep(vnlruproc, &vnode_free_list_mtx, 1270 PVFS|PDROP, "vlruwt", hz); 1271 continue; 1272 } 1273 mtx_unlock(&vnode_free_list_mtx); 1274 done = 0; 1275 onumvnodes = numvnodes; 1276 /* 1277 * Calculate parameters for recycling. These are the same 1278 * throughout the loop to give some semblance of fairness. 1279 * The trigger point is to avoid recycling vnodes with lots 1280 * of resident pages. We aren't trying to free memory; we 1281 * are trying to recycle or at least free vnodes. 1282 */ 1283 if (numvnodes <= desiredvnodes) 1284 usevnodes = numvnodes - freevnodes; 1285 else 1286 usevnodes = numvnodes; 1287 if (usevnodes <= 0) 1288 usevnodes = 1; 1289 /* 1290 * The trigger value is is chosen to give a conservatively 1291 * large value to ensure that it alone doesn't prevent 1292 * making progress. The value can easily be so large that 1293 * it is effectively infinite in some congested and 1294 * misconfigured cases, and this is necessary. Normally 1295 * it is about 8 to 100 (pages), which is quite large. 1296 */ 1297 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1298 if (force < 2) 1299 trigger = vsmalltrigger; 1300 reclaim_nc_src = force >= 3; 1301 mtx_lock(&mountlist_mtx); 1302 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1303 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { 1304 nmp = TAILQ_NEXT(mp, mnt_list); 1305 continue; 1306 } 1307 done += vlrureclaim(mp, reclaim_nc_src, trigger); 1308 mtx_lock(&mountlist_mtx); 1309 nmp = TAILQ_NEXT(mp, mnt_list); 1310 vfs_unbusy(mp); 1311 } 1312 mtx_unlock(&mountlist_mtx); 1313 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1314 uma_reclaim(); 1315 if (done == 0) { 1316 if (force == 0 || force == 1) { 1317 force = 2; 1318 continue; 1319 } 1320 if (force == 2) { 1321 force = 3; 1322 continue; 1323 } 1324 force = 0; 1325 vnlru_nowhere++; 1326 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1327 } else 1328 kern_yield(PRI_USER); 1329 /* 1330 * After becoming active to expand above low water, keep 1331 * active until above high water. 1332 */ 1333 force = vspace() < vhiwat; 1334 } 1335 } 1336 1337 static struct kproc_desc vnlru_kp = { 1338 "vnlru", 1339 vnlru_proc, 1340 &vnlruproc 1341 }; 1342 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1343 &vnlru_kp); 1344 1345 /* 1346 * Routines having to do with the management of the vnode table. 1347 */ 1348 1349 /* 1350 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1351 * before we actually vgone(). This function must be called with the vnode 1352 * held to prevent the vnode from being returned to the free list midway 1353 * through vgone(). 1354 */ 1355 static int 1356 vtryrecycle(struct vnode *vp) 1357 { 1358 struct mount *vnmp; 1359 1360 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1361 VNASSERT(vp->v_holdcnt, vp, 1362 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1363 /* 1364 * This vnode may found and locked via some other list, if so we 1365 * can't recycle it yet. 1366 */ 1367 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1368 CTR2(KTR_VFS, 1369 "%s: impossible to recycle, vp %p lock is already held", 1370 __func__, vp); 1371 return (EWOULDBLOCK); 1372 } 1373 /* 1374 * Don't recycle if its filesystem is being suspended. 1375 */ 1376 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1377 VOP_UNLOCK(vp, 0); 1378 CTR2(KTR_VFS, 1379 "%s: impossible to recycle, cannot start the write for %p", 1380 __func__, vp); 1381 return (EBUSY); 1382 } 1383 /* 1384 * If we got this far, we need to acquire the interlock and see if 1385 * anyone picked up this vnode from another list. If not, we will 1386 * mark it with DOOMED via vgonel() so that anyone who does find it 1387 * will skip over it. 1388 */ 1389 VI_LOCK(vp); 1390 if (vp->v_usecount) { 1391 VOP_UNLOCK(vp, LK_INTERLOCK); 1392 vn_finished_write(vnmp); 1393 CTR2(KTR_VFS, 1394 "%s: impossible to recycle, %p is already referenced", 1395 __func__, vp); 1396 return (EBUSY); 1397 } 1398 if ((vp->v_iflag & VI_DOOMED) == 0) { 1399 counter_u64_add(recycles_count, 1); 1400 vgonel(vp); 1401 } 1402 VOP_UNLOCK(vp, LK_INTERLOCK); 1403 vn_finished_write(vnmp); 1404 return (0); 1405 } 1406 1407 static void 1408 vcheckspace(void) 1409 { 1410 1411 if (vspace() < vlowat && vnlruproc_sig == 0) { 1412 vnlruproc_sig = 1; 1413 wakeup(vnlruproc); 1414 } 1415 } 1416 1417 /* 1418 * Wait if necessary for space for a new vnode. 1419 */ 1420 static int 1421 getnewvnode_wait(int suspended) 1422 { 1423 1424 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1425 if (numvnodes >= desiredvnodes) { 1426 if (suspended) { 1427 /* 1428 * The file system is being suspended. We cannot 1429 * risk a deadlock here, so allow allocation of 1430 * another vnode even if this would give too many. 1431 */ 1432 return (0); 1433 } 1434 if (vnlruproc_sig == 0) { 1435 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 1436 wakeup(vnlruproc); 1437 } 1438 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 1439 "vlruwk", hz); 1440 } 1441 /* Post-adjust like the pre-adjust in getnewvnode(). */ 1442 if (numvnodes + 1 > desiredvnodes && freevnodes > 1) 1443 vnlru_free_locked(1, NULL); 1444 return (numvnodes >= desiredvnodes ? ENFILE : 0); 1445 } 1446 1447 /* 1448 * This hack is fragile, and probably not needed any more now that the 1449 * watermark handling works. 1450 */ 1451 void 1452 getnewvnode_reserve(u_int count) 1453 { 1454 struct thread *td; 1455 1456 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */ 1457 /* XXX no longer so quick, but this part is not racy. */ 1458 mtx_lock(&vnode_free_list_mtx); 1459 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes) 1460 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes, 1461 freevnodes - wantfreevnodes), NULL); 1462 mtx_unlock(&vnode_free_list_mtx); 1463 1464 td = curthread; 1465 /* First try to be quick and racy. */ 1466 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) { 1467 td->td_vp_reserv += count; 1468 vcheckspace(); /* XXX no longer so quick, but more racy */ 1469 return; 1470 } else 1471 atomic_subtract_long(&numvnodes, count); 1472 1473 mtx_lock(&vnode_free_list_mtx); 1474 while (count > 0) { 1475 if (getnewvnode_wait(0) == 0) { 1476 count--; 1477 td->td_vp_reserv++; 1478 atomic_add_long(&numvnodes, 1); 1479 } 1480 } 1481 vcheckspace(); 1482 mtx_unlock(&vnode_free_list_mtx); 1483 } 1484 1485 /* 1486 * This hack is fragile, especially if desiredvnodes or wantvnodes are 1487 * misconfgured or changed significantly. Reducing desiredvnodes below 1488 * the reserved amount should cause bizarre behaviour like reducing it 1489 * below the number of active vnodes -- the system will try to reduce 1490 * numvnodes to match, but should fail, so the subtraction below should 1491 * not overflow. 1492 */ 1493 void 1494 getnewvnode_drop_reserve(void) 1495 { 1496 struct thread *td; 1497 1498 td = curthread; 1499 atomic_subtract_long(&numvnodes, td->td_vp_reserv); 1500 td->td_vp_reserv = 0; 1501 } 1502 1503 /* 1504 * Return the next vnode from the free list. 1505 */ 1506 int 1507 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1508 struct vnode **vpp) 1509 { 1510 struct vnode *vp; 1511 struct thread *td; 1512 struct lock_object *lo; 1513 static int cyclecount; 1514 int error __unused; 1515 1516 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1517 vp = NULL; 1518 td = curthread; 1519 if (td->td_vp_reserv > 0) { 1520 td->td_vp_reserv -= 1; 1521 goto alloc; 1522 } 1523 mtx_lock(&vnode_free_list_mtx); 1524 if (numvnodes < desiredvnodes) 1525 cyclecount = 0; 1526 else if (cyclecount++ >= freevnodes) { 1527 cyclecount = 0; 1528 vstir = 1; 1529 } 1530 /* 1531 * Grow the vnode cache if it will not be above its target max 1532 * after growing. Otherwise, if the free list is nonempty, try 1533 * to reclaim 1 item from it before growing the cache (possibly 1534 * above its target max if the reclamation failed or is delayed). 1535 * Otherwise, wait for some space. In all cases, schedule 1536 * vnlru_proc() if we are getting short of space. The watermarks 1537 * should be chosen so that we never wait or even reclaim from 1538 * the free list to below its target minimum. 1539 */ 1540 if (numvnodes + 1 <= desiredvnodes) 1541 ; 1542 else if (freevnodes > 0) 1543 vnlru_free_locked(1, NULL); 1544 else { 1545 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag & 1546 MNTK_SUSPEND)); 1547 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 1548 if (error != 0) { 1549 mtx_unlock(&vnode_free_list_mtx); 1550 return (error); 1551 } 1552 #endif 1553 } 1554 vcheckspace(); 1555 atomic_add_long(&numvnodes, 1); 1556 mtx_unlock(&vnode_free_list_mtx); 1557 alloc: 1558 counter_u64_add(vnodes_created, 1); 1559 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 1560 /* 1561 * Locks are given the generic name "vnode" when created. 1562 * Follow the historic practice of using the filesystem 1563 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1564 * 1565 * Locks live in a witness group keyed on their name. Thus, 1566 * when a lock is renamed, it must also move from the witness 1567 * group of its old name to the witness group of its new name. 1568 * 1569 * The change only needs to be made when the vnode moves 1570 * from one filesystem type to another. We ensure that each 1571 * filesystem use a single static name pointer for its tag so 1572 * that we can compare pointers rather than doing a strcmp(). 1573 */ 1574 lo = &vp->v_vnlock->lock_object; 1575 if (lo->lo_name != tag) { 1576 lo->lo_name = tag; 1577 WITNESS_DESTROY(lo); 1578 WITNESS_INIT(lo, tag); 1579 } 1580 /* 1581 * By default, don't allow shared locks unless filesystems opt-in. 1582 */ 1583 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1584 /* 1585 * Finalize various vnode identity bits. 1586 */ 1587 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1588 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1589 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1590 vp->v_type = VNON; 1591 vp->v_tag = tag; 1592 vp->v_op = vops; 1593 v_init_counters(vp); 1594 vp->v_bufobj.bo_ops = &buf_ops_bio; 1595 #ifdef DIAGNOSTIC 1596 if (mp == NULL && vops != &dead_vnodeops) 1597 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1598 #endif 1599 #ifdef MAC 1600 mac_vnode_init(vp); 1601 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1602 mac_vnode_associate_singlelabel(mp, vp); 1603 #endif 1604 if (mp != NULL) { 1605 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1606 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1607 vp->v_vflag |= VV_NOKNOTE; 1608 } 1609 1610 /* 1611 * For the filesystems which do not use vfs_hash_insert(), 1612 * still initialize v_hash to have vfs_hash_index() useful. 1613 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1614 * its own hashing. 1615 */ 1616 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1617 1618 *vpp = vp; 1619 return (0); 1620 } 1621 1622 /* 1623 * Delete from old mount point vnode list, if on one. 1624 */ 1625 static void 1626 delmntque(struct vnode *vp) 1627 { 1628 struct mount *mp; 1629 int active; 1630 1631 mp = vp->v_mount; 1632 if (mp == NULL) 1633 return; 1634 MNT_ILOCK(mp); 1635 VI_LOCK(vp); 1636 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize, 1637 ("Active vnode list size %d > Vnode list size %d", 1638 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize)); 1639 active = vp->v_iflag & VI_ACTIVE; 1640 vp->v_iflag &= ~VI_ACTIVE; 1641 if (active) { 1642 mtx_lock(&mp->mnt_listmtx); 1643 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); 1644 mp->mnt_activevnodelistsize--; 1645 mtx_unlock(&mp->mnt_listmtx); 1646 } 1647 vp->v_mount = NULL; 1648 VI_UNLOCK(vp); 1649 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1650 ("bad mount point vnode list size")); 1651 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1652 mp->mnt_nvnodelistsize--; 1653 MNT_REL(mp); 1654 MNT_IUNLOCK(mp); 1655 } 1656 1657 static void 1658 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1659 { 1660 1661 vp->v_data = NULL; 1662 vp->v_op = &dead_vnodeops; 1663 vgone(vp); 1664 vput(vp); 1665 } 1666 1667 /* 1668 * Insert into list of vnodes for the new mount point, if available. 1669 */ 1670 int 1671 insmntque1(struct vnode *vp, struct mount *mp, 1672 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1673 { 1674 1675 KASSERT(vp->v_mount == NULL, 1676 ("insmntque: vnode already on per mount vnode list")); 1677 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1678 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1679 1680 /* 1681 * We acquire the vnode interlock early to ensure that the 1682 * vnode cannot be recycled by another process releasing a 1683 * holdcnt on it before we get it on both the vnode list 1684 * and the active vnode list. The mount mutex protects only 1685 * manipulation of the vnode list and the vnode freelist 1686 * mutex protects only manipulation of the active vnode list. 1687 * Hence the need to hold the vnode interlock throughout. 1688 */ 1689 MNT_ILOCK(mp); 1690 VI_LOCK(vp); 1691 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1692 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1693 mp->mnt_nvnodelistsize == 0)) && 1694 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1695 VI_UNLOCK(vp); 1696 MNT_IUNLOCK(mp); 1697 if (dtr != NULL) 1698 dtr(vp, dtr_arg); 1699 return (EBUSY); 1700 } 1701 vp->v_mount = mp; 1702 MNT_REF(mp); 1703 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1704 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1705 ("neg mount point vnode list size")); 1706 mp->mnt_nvnodelistsize++; 1707 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1708 ("Activating already active vnode")); 1709 vp->v_iflag |= VI_ACTIVE; 1710 mtx_lock(&mp->mnt_listmtx); 1711 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 1712 mp->mnt_activevnodelistsize++; 1713 mtx_unlock(&mp->mnt_listmtx); 1714 VI_UNLOCK(vp); 1715 MNT_IUNLOCK(mp); 1716 return (0); 1717 } 1718 1719 int 1720 insmntque(struct vnode *vp, struct mount *mp) 1721 { 1722 1723 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1724 } 1725 1726 /* 1727 * Flush out and invalidate all buffers associated with a bufobj 1728 * Called with the underlying object locked. 1729 */ 1730 int 1731 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1732 { 1733 int error; 1734 1735 BO_LOCK(bo); 1736 if (flags & V_SAVE) { 1737 error = bufobj_wwait(bo, slpflag, slptimeo); 1738 if (error) { 1739 BO_UNLOCK(bo); 1740 return (error); 1741 } 1742 if (bo->bo_dirty.bv_cnt > 0) { 1743 BO_UNLOCK(bo); 1744 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1745 return (error); 1746 /* 1747 * XXX We could save a lock/unlock if this was only 1748 * enabled under INVARIANTS 1749 */ 1750 BO_LOCK(bo); 1751 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1752 panic("vinvalbuf: dirty bufs"); 1753 } 1754 } 1755 /* 1756 * If you alter this loop please notice that interlock is dropped and 1757 * reacquired in flushbuflist. Special care is needed to ensure that 1758 * no race conditions occur from this. 1759 */ 1760 do { 1761 error = flushbuflist(&bo->bo_clean, 1762 flags, bo, slpflag, slptimeo); 1763 if (error == 0 && !(flags & V_CLEANONLY)) 1764 error = flushbuflist(&bo->bo_dirty, 1765 flags, bo, slpflag, slptimeo); 1766 if (error != 0 && error != EAGAIN) { 1767 BO_UNLOCK(bo); 1768 return (error); 1769 } 1770 } while (error != 0); 1771 1772 /* 1773 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1774 * have write I/O in-progress but if there is a VM object then the 1775 * VM object can also have read-I/O in-progress. 1776 */ 1777 do { 1778 bufobj_wwait(bo, 0, 0); 1779 if ((flags & V_VMIO) == 0) { 1780 BO_UNLOCK(bo); 1781 if (bo->bo_object != NULL) { 1782 VM_OBJECT_WLOCK(bo->bo_object); 1783 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1784 VM_OBJECT_WUNLOCK(bo->bo_object); 1785 } 1786 BO_LOCK(bo); 1787 } 1788 } while (bo->bo_numoutput > 0); 1789 BO_UNLOCK(bo); 1790 1791 /* 1792 * Destroy the copy in the VM cache, too. 1793 */ 1794 if (bo->bo_object != NULL && 1795 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1796 VM_OBJECT_WLOCK(bo->bo_object); 1797 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1798 OBJPR_CLEANONLY : 0); 1799 VM_OBJECT_WUNLOCK(bo->bo_object); 1800 } 1801 1802 #ifdef INVARIANTS 1803 BO_LOCK(bo); 1804 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1805 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1806 bo->bo_clean.bv_cnt > 0)) 1807 panic("vinvalbuf: flush failed"); 1808 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1809 bo->bo_dirty.bv_cnt > 0) 1810 panic("vinvalbuf: flush dirty failed"); 1811 BO_UNLOCK(bo); 1812 #endif 1813 return (0); 1814 } 1815 1816 /* 1817 * Flush out and invalidate all buffers associated with a vnode. 1818 * Called with the underlying object locked. 1819 */ 1820 int 1821 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1822 { 1823 1824 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1825 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1826 if (vp->v_object != NULL && vp->v_object->handle != vp) 1827 return (0); 1828 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1829 } 1830 1831 /* 1832 * Flush out buffers on the specified list. 1833 * 1834 */ 1835 static int 1836 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1837 int slptimeo) 1838 { 1839 struct buf *bp, *nbp; 1840 int retval, error; 1841 daddr_t lblkno; 1842 b_xflags_t xflags; 1843 1844 ASSERT_BO_WLOCKED(bo); 1845 1846 retval = 0; 1847 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1848 /* 1849 * If we are flushing both V_NORMAL and V_ALT buffers then 1850 * do not skip any buffers. If we are flushing only V_NORMAL 1851 * buffers then skip buffers marked as BX_ALTDATA. If we are 1852 * flushing only V_ALT buffers then skip buffers not marked 1853 * as BX_ALTDATA. 1854 */ 1855 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 1856 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 1857 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 1858 continue; 1859 } 1860 if (nbp != NULL) { 1861 lblkno = nbp->b_lblkno; 1862 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1863 } 1864 retval = EAGAIN; 1865 error = BUF_TIMELOCK(bp, 1866 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1867 "flushbuf", slpflag, slptimeo); 1868 if (error) { 1869 BO_LOCK(bo); 1870 return (error != ENOLCK ? error : EAGAIN); 1871 } 1872 KASSERT(bp->b_bufobj == bo, 1873 ("bp %p wrong b_bufobj %p should be %p", 1874 bp, bp->b_bufobj, bo)); 1875 /* 1876 * XXX Since there are no node locks for NFS, I 1877 * believe there is a slight chance that a delayed 1878 * write will occur while sleeping just above, so 1879 * check for it. 1880 */ 1881 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1882 (flags & V_SAVE)) { 1883 bremfree(bp); 1884 bp->b_flags |= B_ASYNC; 1885 bwrite(bp); 1886 BO_LOCK(bo); 1887 return (EAGAIN); /* XXX: why not loop ? */ 1888 } 1889 bremfree(bp); 1890 bp->b_flags |= (B_INVAL | B_RELBUF); 1891 bp->b_flags &= ~B_ASYNC; 1892 brelse(bp); 1893 BO_LOCK(bo); 1894 if (nbp == NULL) 1895 break; 1896 nbp = gbincore(bo, lblkno); 1897 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1898 != xflags) 1899 break; /* nbp invalid */ 1900 } 1901 return (retval); 1902 } 1903 1904 int 1905 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 1906 { 1907 struct buf *bp; 1908 int error; 1909 daddr_t lblkno; 1910 1911 ASSERT_BO_LOCKED(bo); 1912 1913 for (lblkno = startn;;) { 1914 again: 1915 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 1916 if (bp == NULL || bp->b_lblkno >= endn || 1917 bp->b_lblkno < startn) 1918 break; 1919 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 1920 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 1921 if (error != 0) { 1922 BO_RLOCK(bo); 1923 if (error == ENOLCK) 1924 goto again; 1925 return (error); 1926 } 1927 KASSERT(bp->b_bufobj == bo, 1928 ("bp %p wrong b_bufobj %p should be %p", 1929 bp, bp->b_bufobj, bo)); 1930 lblkno = bp->b_lblkno + 1; 1931 if ((bp->b_flags & B_MANAGED) == 0) 1932 bremfree(bp); 1933 bp->b_flags |= B_RELBUF; 1934 /* 1935 * In the VMIO case, use the B_NOREUSE flag to hint that the 1936 * pages backing each buffer in the range are unlikely to be 1937 * reused. Dirty buffers will have the hint applied once 1938 * they've been written. 1939 */ 1940 if ((bp->b_flags & B_VMIO) != 0) 1941 bp->b_flags |= B_NOREUSE; 1942 brelse(bp); 1943 BO_RLOCK(bo); 1944 } 1945 return (0); 1946 } 1947 1948 /* 1949 * Truncate a file's buffer and pages to a specified length. This 1950 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1951 * sync activity. 1952 */ 1953 int 1954 vtruncbuf(struct vnode *vp, off_t length, int blksize) 1955 { 1956 struct buf *bp, *nbp; 1957 int anyfreed; 1958 daddr_t trunclbn; 1959 struct bufobj *bo; 1960 1961 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 1962 vp, blksize, (uintmax_t)length); 1963 1964 /* 1965 * Round up to the *next* lbn. 1966 */ 1967 trunclbn = howmany(length, blksize); 1968 1969 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1970 restart: 1971 bo = &vp->v_bufobj; 1972 BO_LOCK(bo); 1973 anyfreed = 1; 1974 for (;anyfreed;) { 1975 anyfreed = 0; 1976 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1977 if (bp->b_lblkno < trunclbn) 1978 continue; 1979 if (BUF_LOCK(bp, 1980 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1981 BO_LOCKPTR(bo)) == ENOLCK) 1982 goto restart; 1983 1984 bremfree(bp); 1985 bp->b_flags |= (B_INVAL | B_RELBUF); 1986 bp->b_flags &= ~B_ASYNC; 1987 brelse(bp); 1988 anyfreed = 1; 1989 1990 BO_LOCK(bo); 1991 if (nbp != NULL && 1992 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1993 (nbp->b_vp != vp) || 1994 (nbp->b_flags & B_DELWRI))) { 1995 BO_UNLOCK(bo); 1996 goto restart; 1997 } 1998 } 1999 2000 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2001 if (bp->b_lblkno < trunclbn) 2002 continue; 2003 if (BUF_LOCK(bp, 2004 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2005 BO_LOCKPTR(bo)) == ENOLCK) 2006 goto restart; 2007 bremfree(bp); 2008 bp->b_flags |= (B_INVAL | B_RELBUF); 2009 bp->b_flags &= ~B_ASYNC; 2010 brelse(bp); 2011 anyfreed = 1; 2012 2013 BO_LOCK(bo); 2014 if (nbp != NULL && 2015 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2016 (nbp->b_vp != vp) || 2017 (nbp->b_flags & B_DELWRI) == 0)) { 2018 BO_UNLOCK(bo); 2019 goto restart; 2020 } 2021 } 2022 } 2023 2024 if (length > 0) { 2025 restartsync: 2026 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2027 if (bp->b_lblkno > 0) 2028 continue; 2029 /* 2030 * Since we hold the vnode lock this should only 2031 * fail if we're racing with the buf daemon. 2032 */ 2033 if (BUF_LOCK(bp, 2034 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2035 BO_LOCKPTR(bo)) == ENOLCK) { 2036 goto restart; 2037 } 2038 VNASSERT((bp->b_flags & B_DELWRI), vp, 2039 ("buf(%p) on dirty queue without DELWRI", bp)); 2040 2041 bremfree(bp); 2042 bawrite(bp); 2043 BO_LOCK(bo); 2044 goto restartsync; 2045 } 2046 } 2047 2048 bufobj_wwait(bo, 0, 0); 2049 BO_UNLOCK(bo); 2050 vnode_pager_setsize(vp, length); 2051 2052 return (0); 2053 } 2054 2055 static void 2056 buf_vlist_remove(struct buf *bp) 2057 { 2058 struct bufv *bv; 2059 2060 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2061 ASSERT_BO_WLOCKED(bp->b_bufobj); 2062 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 2063 (BX_VNDIRTY|BX_VNCLEAN), 2064 ("buf_vlist_remove: Buf %p is on two lists", bp)); 2065 if (bp->b_xflags & BX_VNDIRTY) 2066 bv = &bp->b_bufobj->bo_dirty; 2067 else 2068 bv = &bp->b_bufobj->bo_clean; 2069 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2070 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2071 bv->bv_cnt--; 2072 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2073 } 2074 2075 /* 2076 * Add the buffer to the sorted clean or dirty block list. 2077 * 2078 * NOTE: xflags is passed as a constant, optimizing this inline function! 2079 */ 2080 static void 2081 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2082 { 2083 struct bufv *bv; 2084 struct buf *n; 2085 int error; 2086 2087 ASSERT_BO_WLOCKED(bo); 2088 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2089 ("dead bo %p", bo)); 2090 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2091 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2092 bp->b_xflags |= xflags; 2093 if (xflags & BX_VNDIRTY) 2094 bv = &bo->bo_dirty; 2095 else 2096 bv = &bo->bo_clean; 2097 2098 /* 2099 * Keep the list ordered. Optimize empty list insertion. Assume 2100 * we tend to grow at the tail so lookup_le should usually be cheaper 2101 * than _ge. 2102 */ 2103 if (bv->bv_cnt == 0 || 2104 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2105 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2106 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2107 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2108 else 2109 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2110 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2111 if (error) 2112 panic("buf_vlist_add: Preallocated nodes insufficient."); 2113 bv->bv_cnt++; 2114 } 2115 2116 /* 2117 * Look up a buffer using the buffer tries. 2118 */ 2119 struct buf * 2120 gbincore(struct bufobj *bo, daddr_t lblkno) 2121 { 2122 struct buf *bp; 2123 2124 ASSERT_BO_LOCKED(bo); 2125 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2126 if (bp != NULL) 2127 return (bp); 2128 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2129 } 2130 2131 /* 2132 * Associate a buffer with a vnode. 2133 */ 2134 void 2135 bgetvp(struct vnode *vp, struct buf *bp) 2136 { 2137 struct bufobj *bo; 2138 2139 bo = &vp->v_bufobj; 2140 ASSERT_BO_WLOCKED(bo); 2141 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2142 2143 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2144 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2145 ("bgetvp: bp already attached! %p", bp)); 2146 2147 vhold(vp); 2148 bp->b_vp = vp; 2149 bp->b_bufobj = bo; 2150 /* 2151 * Insert onto list for new vnode. 2152 */ 2153 buf_vlist_add(bp, bo, BX_VNCLEAN); 2154 } 2155 2156 /* 2157 * Disassociate a buffer from a vnode. 2158 */ 2159 void 2160 brelvp(struct buf *bp) 2161 { 2162 struct bufobj *bo; 2163 struct vnode *vp; 2164 2165 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2166 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2167 2168 /* 2169 * Delete from old vnode list, if on one. 2170 */ 2171 vp = bp->b_vp; /* XXX */ 2172 bo = bp->b_bufobj; 2173 BO_LOCK(bo); 2174 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2175 buf_vlist_remove(bp); 2176 else 2177 panic("brelvp: Buffer %p not on queue.", bp); 2178 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2179 bo->bo_flag &= ~BO_ONWORKLST; 2180 mtx_lock(&sync_mtx); 2181 LIST_REMOVE(bo, bo_synclist); 2182 syncer_worklist_len--; 2183 mtx_unlock(&sync_mtx); 2184 } 2185 bp->b_vp = NULL; 2186 bp->b_bufobj = NULL; 2187 BO_UNLOCK(bo); 2188 vdrop(vp); 2189 } 2190 2191 /* 2192 * Add an item to the syncer work queue. 2193 */ 2194 static void 2195 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2196 { 2197 int slot; 2198 2199 ASSERT_BO_WLOCKED(bo); 2200 2201 mtx_lock(&sync_mtx); 2202 if (bo->bo_flag & BO_ONWORKLST) 2203 LIST_REMOVE(bo, bo_synclist); 2204 else { 2205 bo->bo_flag |= BO_ONWORKLST; 2206 syncer_worklist_len++; 2207 } 2208 2209 if (delay > syncer_maxdelay - 2) 2210 delay = syncer_maxdelay - 2; 2211 slot = (syncer_delayno + delay) & syncer_mask; 2212 2213 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2214 mtx_unlock(&sync_mtx); 2215 } 2216 2217 static int 2218 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2219 { 2220 int error, len; 2221 2222 mtx_lock(&sync_mtx); 2223 len = syncer_worklist_len - sync_vnode_count; 2224 mtx_unlock(&sync_mtx); 2225 error = SYSCTL_OUT(req, &len, sizeof(len)); 2226 return (error); 2227 } 2228 2229 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 2230 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2231 2232 static struct proc *updateproc; 2233 static void sched_sync(void); 2234 static struct kproc_desc up_kp = { 2235 "syncer", 2236 sched_sync, 2237 &updateproc 2238 }; 2239 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2240 2241 static int 2242 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2243 { 2244 struct vnode *vp; 2245 struct mount *mp; 2246 2247 *bo = LIST_FIRST(slp); 2248 if (*bo == NULL) 2249 return (0); 2250 vp = bo2vnode(*bo); 2251 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2252 return (1); 2253 /* 2254 * We use vhold in case the vnode does not 2255 * successfully sync. vhold prevents the vnode from 2256 * going away when we unlock the sync_mtx so that 2257 * we can acquire the vnode interlock. 2258 */ 2259 vholdl(vp); 2260 mtx_unlock(&sync_mtx); 2261 VI_UNLOCK(vp); 2262 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2263 vdrop(vp); 2264 mtx_lock(&sync_mtx); 2265 return (*bo == LIST_FIRST(slp)); 2266 } 2267 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2268 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2269 VOP_UNLOCK(vp, 0); 2270 vn_finished_write(mp); 2271 BO_LOCK(*bo); 2272 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2273 /* 2274 * Put us back on the worklist. The worklist 2275 * routine will remove us from our current 2276 * position and then add us back in at a later 2277 * position. 2278 */ 2279 vn_syncer_add_to_worklist(*bo, syncdelay); 2280 } 2281 BO_UNLOCK(*bo); 2282 vdrop(vp); 2283 mtx_lock(&sync_mtx); 2284 return (0); 2285 } 2286 2287 static int first_printf = 1; 2288 2289 /* 2290 * System filesystem synchronizer daemon. 2291 */ 2292 static void 2293 sched_sync(void) 2294 { 2295 struct synclist *next, *slp; 2296 struct bufobj *bo; 2297 long starttime; 2298 struct thread *td = curthread; 2299 int last_work_seen; 2300 int net_worklist_len; 2301 int syncer_final_iter; 2302 int error; 2303 2304 last_work_seen = 0; 2305 syncer_final_iter = 0; 2306 syncer_state = SYNCER_RUNNING; 2307 starttime = time_uptime; 2308 td->td_pflags |= TDP_NORUNNINGBUF; 2309 2310 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2311 SHUTDOWN_PRI_LAST); 2312 2313 mtx_lock(&sync_mtx); 2314 for (;;) { 2315 if (syncer_state == SYNCER_FINAL_DELAY && 2316 syncer_final_iter == 0) { 2317 mtx_unlock(&sync_mtx); 2318 kproc_suspend_check(td->td_proc); 2319 mtx_lock(&sync_mtx); 2320 } 2321 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2322 if (syncer_state != SYNCER_RUNNING && 2323 starttime != time_uptime) { 2324 if (first_printf) { 2325 printf("\nSyncing disks, vnodes remaining... "); 2326 first_printf = 0; 2327 } 2328 printf("%d ", net_worklist_len); 2329 } 2330 starttime = time_uptime; 2331 2332 /* 2333 * Push files whose dirty time has expired. Be careful 2334 * of interrupt race on slp queue. 2335 * 2336 * Skip over empty worklist slots when shutting down. 2337 */ 2338 do { 2339 slp = &syncer_workitem_pending[syncer_delayno]; 2340 syncer_delayno += 1; 2341 if (syncer_delayno == syncer_maxdelay) 2342 syncer_delayno = 0; 2343 next = &syncer_workitem_pending[syncer_delayno]; 2344 /* 2345 * If the worklist has wrapped since the 2346 * it was emptied of all but syncer vnodes, 2347 * switch to the FINAL_DELAY state and run 2348 * for one more second. 2349 */ 2350 if (syncer_state == SYNCER_SHUTTING_DOWN && 2351 net_worklist_len == 0 && 2352 last_work_seen == syncer_delayno) { 2353 syncer_state = SYNCER_FINAL_DELAY; 2354 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2355 } 2356 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2357 syncer_worklist_len > 0); 2358 2359 /* 2360 * Keep track of the last time there was anything 2361 * on the worklist other than syncer vnodes. 2362 * Return to the SHUTTING_DOWN state if any 2363 * new work appears. 2364 */ 2365 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2366 last_work_seen = syncer_delayno; 2367 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2368 syncer_state = SYNCER_SHUTTING_DOWN; 2369 while (!LIST_EMPTY(slp)) { 2370 error = sync_vnode(slp, &bo, td); 2371 if (error == 1) { 2372 LIST_REMOVE(bo, bo_synclist); 2373 LIST_INSERT_HEAD(next, bo, bo_synclist); 2374 continue; 2375 } 2376 2377 if (first_printf == 0) { 2378 /* 2379 * Drop the sync mutex, because some watchdog 2380 * drivers need to sleep while patting 2381 */ 2382 mtx_unlock(&sync_mtx); 2383 wdog_kern_pat(WD_LASTVAL); 2384 mtx_lock(&sync_mtx); 2385 } 2386 2387 } 2388 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2389 syncer_final_iter--; 2390 /* 2391 * The variable rushjob allows the kernel to speed up the 2392 * processing of the filesystem syncer process. A rushjob 2393 * value of N tells the filesystem syncer to process the next 2394 * N seconds worth of work on its queue ASAP. Currently rushjob 2395 * is used by the soft update code to speed up the filesystem 2396 * syncer process when the incore state is getting so far 2397 * ahead of the disk that the kernel memory pool is being 2398 * threatened with exhaustion. 2399 */ 2400 if (rushjob > 0) { 2401 rushjob -= 1; 2402 continue; 2403 } 2404 /* 2405 * Just sleep for a short period of time between 2406 * iterations when shutting down to allow some I/O 2407 * to happen. 2408 * 2409 * If it has taken us less than a second to process the 2410 * current work, then wait. Otherwise start right over 2411 * again. We can still lose time if any single round 2412 * takes more than two seconds, but it does not really 2413 * matter as we are just trying to generally pace the 2414 * filesystem activity. 2415 */ 2416 if (syncer_state != SYNCER_RUNNING || 2417 time_uptime == starttime) { 2418 thread_lock(td); 2419 sched_prio(td, PPAUSE); 2420 thread_unlock(td); 2421 } 2422 if (syncer_state != SYNCER_RUNNING) 2423 cv_timedwait(&sync_wakeup, &sync_mtx, 2424 hz / SYNCER_SHUTDOWN_SPEEDUP); 2425 else if (time_uptime == starttime) 2426 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2427 } 2428 } 2429 2430 /* 2431 * Request the syncer daemon to speed up its work. 2432 * We never push it to speed up more than half of its 2433 * normal turn time, otherwise it could take over the cpu. 2434 */ 2435 int 2436 speedup_syncer(void) 2437 { 2438 int ret = 0; 2439 2440 mtx_lock(&sync_mtx); 2441 if (rushjob < syncdelay / 2) { 2442 rushjob += 1; 2443 stat_rush_requests += 1; 2444 ret = 1; 2445 } 2446 mtx_unlock(&sync_mtx); 2447 cv_broadcast(&sync_wakeup); 2448 return (ret); 2449 } 2450 2451 /* 2452 * Tell the syncer to speed up its work and run though its work 2453 * list several times, then tell it to shut down. 2454 */ 2455 static void 2456 syncer_shutdown(void *arg, int howto) 2457 { 2458 2459 if (howto & RB_NOSYNC) 2460 return; 2461 mtx_lock(&sync_mtx); 2462 syncer_state = SYNCER_SHUTTING_DOWN; 2463 rushjob = 0; 2464 mtx_unlock(&sync_mtx); 2465 cv_broadcast(&sync_wakeup); 2466 kproc_shutdown(arg, howto); 2467 } 2468 2469 void 2470 syncer_suspend(void) 2471 { 2472 2473 syncer_shutdown(updateproc, 0); 2474 } 2475 2476 void 2477 syncer_resume(void) 2478 { 2479 2480 mtx_lock(&sync_mtx); 2481 first_printf = 1; 2482 syncer_state = SYNCER_RUNNING; 2483 mtx_unlock(&sync_mtx); 2484 cv_broadcast(&sync_wakeup); 2485 kproc_resume(updateproc); 2486 } 2487 2488 /* 2489 * Reassign a buffer from one vnode to another. 2490 * Used to assign file specific control information 2491 * (indirect blocks) to the vnode to which they belong. 2492 */ 2493 void 2494 reassignbuf(struct buf *bp) 2495 { 2496 struct vnode *vp; 2497 struct bufobj *bo; 2498 int delay; 2499 #ifdef INVARIANTS 2500 struct bufv *bv; 2501 #endif 2502 2503 vp = bp->b_vp; 2504 bo = bp->b_bufobj; 2505 ++reassignbufcalls; 2506 2507 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2508 bp, bp->b_vp, bp->b_flags); 2509 /* 2510 * B_PAGING flagged buffers cannot be reassigned because their vp 2511 * is not fully linked in. 2512 */ 2513 if (bp->b_flags & B_PAGING) 2514 panic("cannot reassign paging buffer"); 2515 2516 /* 2517 * Delete from old vnode list, if on one. 2518 */ 2519 BO_LOCK(bo); 2520 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2521 buf_vlist_remove(bp); 2522 else 2523 panic("reassignbuf: Buffer %p not on queue.", bp); 2524 /* 2525 * If dirty, put on list of dirty buffers; otherwise insert onto list 2526 * of clean buffers. 2527 */ 2528 if (bp->b_flags & B_DELWRI) { 2529 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2530 switch (vp->v_type) { 2531 case VDIR: 2532 delay = dirdelay; 2533 break; 2534 case VCHR: 2535 delay = metadelay; 2536 break; 2537 default: 2538 delay = filedelay; 2539 } 2540 vn_syncer_add_to_worklist(bo, delay); 2541 } 2542 buf_vlist_add(bp, bo, BX_VNDIRTY); 2543 } else { 2544 buf_vlist_add(bp, bo, BX_VNCLEAN); 2545 2546 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2547 mtx_lock(&sync_mtx); 2548 LIST_REMOVE(bo, bo_synclist); 2549 syncer_worklist_len--; 2550 mtx_unlock(&sync_mtx); 2551 bo->bo_flag &= ~BO_ONWORKLST; 2552 } 2553 } 2554 #ifdef INVARIANTS 2555 bv = &bo->bo_clean; 2556 bp = TAILQ_FIRST(&bv->bv_hd); 2557 KASSERT(bp == NULL || bp->b_bufobj == bo, 2558 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2559 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2560 KASSERT(bp == NULL || bp->b_bufobj == bo, 2561 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2562 bv = &bo->bo_dirty; 2563 bp = TAILQ_FIRST(&bv->bv_hd); 2564 KASSERT(bp == NULL || bp->b_bufobj == bo, 2565 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2566 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2567 KASSERT(bp == NULL || bp->b_bufobj == bo, 2568 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2569 #endif 2570 BO_UNLOCK(bo); 2571 } 2572 2573 static void 2574 v_init_counters(struct vnode *vp) 2575 { 2576 2577 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2578 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2579 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2580 2581 refcount_init(&vp->v_holdcnt, 1); 2582 refcount_init(&vp->v_usecount, 1); 2583 } 2584 2585 static void 2586 v_incr_usecount_locked(struct vnode *vp) 2587 { 2588 2589 ASSERT_VI_LOCKED(vp, __func__); 2590 if ((vp->v_iflag & VI_OWEINACT) != 0) { 2591 VNASSERT(vp->v_usecount == 0, vp, 2592 ("vnode with usecount and VI_OWEINACT set")); 2593 vp->v_iflag &= ~VI_OWEINACT; 2594 } 2595 refcount_acquire(&vp->v_usecount); 2596 v_incr_devcount(vp); 2597 } 2598 2599 /* 2600 * Increment the use count on the vnode, taking care to reference 2601 * the driver's usecount if this is a chardev. 2602 */ 2603 static void 2604 v_incr_usecount(struct vnode *vp) 2605 { 2606 2607 ASSERT_VI_UNLOCKED(vp, __func__); 2608 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2609 2610 if (vp->v_type != VCHR && 2611 refcount_acquire_if_not_zero(&vp->v_usecount)) { 2612 VNODE_REFCOUNT_FENCE_ACQ(); 2613 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2614 ("vnode with usecount and VI_OWEINACT set")); 2615 } else { 2616 VI_LOCK(vp); 2617 v_incr_usecount_locked(vp); 2618 VI_UNLOCK(vp); 2619 } 2620 } 2621 2622 /* 2623 * Increment si_usecount of the associated device, if any. 2624 */ 2625 static void 2626 v_incr_devcount(struct vnode *vp) 2627 { 2628 2629 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2630 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2631 dev_lock(); 2632 vp->v_rdev->si_usecount++; 2633 dev_unlock(); 2634 } 2635 } 2636 2637 /* 2638 * Decrement si_usecount of the associated device, if any. 2639 */ 2640 static void 2641 v_decr_devcount(struct vnode *vp) 2642 { 2643 2644 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2645 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2646 dev_lock(); 2647 vp->v_rdev->si_usecount--; 2648 dev_unlock(); 2649 } 2650 } 2651 2652 /* 2653 * Grab a particular vnode from the free list, increment its 2654 * reference count and lock it. VI_DOOMED is set if the vnode 2655 * is being destroyed. Only callers who specify LK_RETRY will 2656 * see doomed vnodes. If inactive processing was delayed in 2657 * vput try to do it here. 2658 * 2659 * Notes on lockless counter manipulation: 2660 * _vhold, vputx and other routines make various decisions based 2661 * on either holdcnt or usecount being 0. As long as either counter 2662 * is not transitioning 0->1 nor 1->0, the manipulation can be done 2663 * with atomic operations. Otherwise the interlock is taken covering 2664 * both the atomic and additional actions. 2665 */ 2666 int 2667 vget(struct vnode *vp, int flags, struct thread *td) 2668 { 2669 int error, oweinact; 2670 2671 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2672 ("vget: invalid lock operation")); 2673 2674 if ((flags & LK_INTERLOCK) != 0) 2675 ASSERT_VI_LOCKED(vp, __func__); 2676 else 2677 ASSERT_VI_UNLOCKED(vp, __func__); 2678 if ((flags & LK_VNHELD) != 0) 2679 VNASSERT((vp->v_holdcnt > 0), vp, 2680 ("vget: LK_VNHELD passed but vnode not held")); 2681 2682 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2683 2684 if ((flags & LK_VNHELD) == 0) 2685 _vhold(vp, (flags & LK_INTERLOCK) != 0); 2686 2687 if ((error = vn_lock(vp, flags)) != 0) { 2688 vdrop(vp); 2689 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2690 vp); 2691 return (error); 2692 } 2693 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2694 panic("vget: vn_lock failed to return ENOENT\n"); 2695 /* 2696 * We don't guarantee that any particular close will 2697 * trigger inactive processing so just make a best effort 2698 * here at preventing a reference to a removed file. If 2699 * we don't succeed no harm is done. 2700 * 2701 * Upgrade our holdcnt to a usecount. 2702 */ 2703 if (vp->v_type == VCHR || 2704 !refcount_acquire_if_not_zero(&vp->v_usecount)) { 2705 VI_LOCK(vp); 2706 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2707 oweinact = 0; 2708 } else { 2709 oweinact = 1; 2710 vp->v_iflag &= ~VI_OWEINACT; 2711 VNODE_REFCOUNT_FENCE_REL(); 2712 } 2713 refcount_acquire(&vp->v_usecount); 2714 v_incr_devcount(vp); 2715 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2716 (flags & LK_NOWAIT) == 0) 2717 vinactive(vp, td); 2718 VI_UNLOCK(vp); 2719 } 2720 return (0); 2721 } 2722 2723 /* 2724 * Increase the reference (use) and hold count of a vnode. 2725 * This will also remove the vnode from the free list if it is presently free. 2726 */ 2727 void 2728 vref(struct vnode *vp) 2729 { 2730 2731 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2732 _vhold(vp, false); 2733 v_incr_usecount(vp); 2734 } 2735 2736 void 2737 vrefl(struct vnode *vp) 2738 { 2739 2740 ASSERT_VI_LOCKED(vp, __func__); 2741 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2742 _vhold(vp, true); 2743 v_incr_usecount_locked(vp); 2744 } 2745 2746 void 2747 vrefact(struct vnode *vp) 2748 { 2749 2750 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2751 if (__predict_false(vp->v_type == VCHR)) { 2752 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 2753 ("%s: wrong ref counts", __func__)); 2754 vref(vp); 2755 return; 2756 } 2757 #ifdef INVARIANTS 2758 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 2759 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__)); 2760 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2761 VNASSERT(old > 0, vp, ("%s: wrong use count", __func__)); 2762 #else 2763 refcount_acquire(&vp->v_holdcnt); 2764 refcount_acquire(&vp->v_usecount); 2765 #endif 2766 } 2767 2768 /* 2769 * Return reference count of a vnode. 2770 * 2771 * The results of this call are only guaranteed when some mechanism is used to 2772 * stop other processes from gaining references to the vnode. This may be the 2773 * case if the caller holds the only reference. This is also useful when stale 2774 * data is acceptable as race conditions may be accounted for by some other 2775 * means. 2776 */ 2777 int 2778 vrefcnt(struct vnode *vp) 2779 { 2780 2781 return (vp->v_usecount); 2782 } 2783 2784 #define VPUTX_VRELE 1 2785 #define VPUTX_VPUT 2 2786 #define VPUTX_VUNREF 3 2787 2788 /* 2789 * Decrement the use and hold counts for a vnode. 2790 * 2791 * See an explanation near vget() as to why atomic operation is safe. 2792 */ 2793 static void 2794 vputx(struct vnode *vp, int func) 2795 { 2796 int error; 2797 2798 KASSERT(vp != NULL, ("vputx: null vp")); 2799 if (func == VPUTX_VUNREF) 2800 ASSERT_VOP_LOCKED(vp, "vunref"); 2801 else if (func == VPUTX_VPUT) 2802 ASSERT_VOP_LOCKED(vp, "vput"); 2803 else 2804 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); 2805 ASSERT_VI_UNLOCKED(vp, __func__); 2806 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2807 2808 if (vp->v_type != VCHR && 2809 refcount_release_if_not_last(&vp->v_usecount)) { 2810 if (func == VPUTX_VPUT) 2811 VOP_UNLOCK(vp, 0); 2812 vdrop(vp); 2813 return; 2814 } 2815 2816 VI_LOCK(vp); 2817 2818 /* 2819 * We want to hold the vnode until the inactive finishes to 2820 * prevent vgone() races. We drop the use count here and the 2821 * hold count below when we're done. 2822 */ 2823 if (!refcount_release(&vp->v_usecount) || 2824 (vp->v_iflag & VI_DOINGINACT)) { 2825 if (func == VPUTX_VPUT) 2826 VOP_UNLOCK(vp, 0); 2827 v_decr_devcount(vp); 2828 vdropl(vp); 2829 return; 2830 } 2831 2832 v_decr_devcount(vp); 2833 2834 error = 0; 2835 2836 if (vp->v_usecount != 0) { 2837 vn_printf(vp, "vputx: usecount not zero for vnode "); 2838 panic("vputx: usecount not zero"); 2839 } 2840 2841 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); 2842 2843 /* 2844 * We must call VOP_INACTIVE with the node locked. Mark 2845 * as VI_DOINGINACT to avoid recursion. 2846 */ 2847 vp->v_iflag |= VI_OWEINACT; 2848 switch (func) { 2849 case VPUTX_VRELE: 2850 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2851 VI_LOCK(vp); 2852 break; 2853 case VPUTX_VPUT: 2854 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2855 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 2856 LK_NOWAIT); 2857 VI_LOCK(vp); 2858 } 2859 break; 2860 case VPUTX_VUNREF: 2861 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2862 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 2863 VI_LOCK(vp); 2864 } 2865 break; 2866 } 2867 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, 2868 ("vnode with usecount and VI_OWEINACT set")); 2869 if (error == 0) { 2870 if (vp->v_iflag & VI_OWEINACT) 2871 vinactive(vp, curthread); 2872 if (func != VPUTX_VUNREF) 2873 VOP_UNLOCK(vp, 0); 2874 } 2875 vdropl(vp); 2876 } 2877 2878 /* 2879 * Vnode put/release. 2880 * If count drops to zero, call inactive routine and return to freelist. 2881 */ 2882 void 2883 vrele(struct vnode *vp) 2884 { 2885 2886 vputx(vp, VPUTX_VRELE); 2887 } 2888 2889 /* 2890 * Release an already locked vnode. This give the same effects as 2891 * unlock+vrele(), but takes less time and avoids releasing and 2892 * re-aquiring the lock (as vrele() acquires the lock internally.) 2893 */ 2894 void 2895 vput(struct vnode *vp) 2896 { 2897 2898 vputx(vp, VPUTX_VPUT); 2899 } 2900 2901 /* 2902 * Release an exclusively locked vnode. Do not unlock the vnode lock. 2903 */ 2904 void 2905 vunref(struct vnode *vp) 2906 { 2907 2908 vputx(vp, VPUTX_VUNREF); 2909 } 2910 2911 /* 2912 * Increase the hold count and activate if this is the first reference. 2913 */ 2914 void 2915 _vhold(struct vnode *vp, bool locked) 2916 { 2917 struct mount *mp; 2918 2919 if (locked) 2920 ASSERT_VI_LOCKED(vp, __func__); 2921 else 2922 ASSERT_VI_UNLOCKED(vp, __func__); 2923 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2924 if (!locked) { 2925 if (refcount_acquire_if_not_zero(&vp->v_holdcnt)) { 2926 VNODE_REFCOUNT_FENCE_ACQ(); 2927 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2928 ("_vhold: vnode with holdcnt is free")); 2929 return; 2930 } 2931 VI_LOCK(vp); 2932 } 2933 if ((vp->v_iflag & VI_FREE) == 0) { 2934 refcount_acquire(&vp->v_holdcnt); 2935 if (!locked) 2936 VI_UNLOCK(vp); 2937 return; 2938 } 2939 VNASSERT(vp->v_holdcnt == 0, vp, 2940 ("%s: wrong hold count", __func__)); 2941 VNASSERT(vp->v_op != NULL, vp, 2942 ("%s: vnode already reclaimed.", __func__)); 2943 /* 2944 * Remove a vnode from the free list, mark it as in use, 2945 * and put it on the active list. 2946 */ 2947 VNASSERT(vp->v_mount != NULL, vp, 2948 ("_vhold: vnode not on per mount vnode list")); 2949 mp = vp->v_mount; 2950 mtx_lock(&mp->mnt_listmtx); 2951 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { 2952 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 2953 mp->mnt_tmpfreevnodelistsize--; 2954 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 2955 } else { 2956 mtx_lock(&vnode_free_list_mtx); 2957 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 2958 freevnodes--; 2959 mtx_unlock(&vnode_free_list_mtx); 2960 } 2961 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 2962 ("Activating already active vnode")); 2963 vp->v_iflag &= ~VI_FREE; 2964 vp->v_iflag |= VI_ACTIVE; 2965 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 2966 mp->mnt_activevnodelistsize++; 2967 mtx_unlock(&mp->mnt_listmtx); 2968 refcount_acquire(&vp->v_holdcnt); 2969 if (!locked) 2970 VI_UNLOCK(vp); 2971 } 2972 2973 /* 2974 * Drop the hold count of the vnode. If this is the last reference to 2975 * the vnode we place it on the free list unless it has been vgone'd 2976 * (marked VI_DOOMED) in which case we will free it. 2977 * 2978 * Because the vnode vm object keeps a hold reference on the vnode if 2979 * there is at least one resident non-cached page, the vnode cannot 2980 * leave the active list without the page cleanup done. 2981 */ 2982 void 2983 _vdrop(struct vnode *vp, bool locked) 2984 { 2985 struct bufobj *bo; 2986 struct mount *mp; 2987 int active; 2988 2989 if (locked) 2990 ASSERT_VI_LOCKED(vp, __func__); 2991 else 2992 ASSERT_VI_UNLOCKED(vp, __func__); 2993 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2994 if ((int)vp->v_holdcnt <= 0) 2995 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2996 if (!locked) { 2997 if (refcount_release_if_not_last(&vp->v_holdcnt)) 2998 return; 2999 VI_LOCK(vp); 3000 } 3001 if (refcount_release(&vp->v_holdcnt) == 0) { 3002 VI_UNLOCK(vp); 3003 return; 3004 } 3005 if ((vp->v_iflag & VI_DOOMED) == 0) { 3006 /* 3007 * Mark a vnode as free: remove it from its active list 3008 * and put it up for recycling on the freelist. 3009 */ 3010 VNASSERT(vp->v_op != NULL, vp, 3011 ("vdropl: vnode already reclaimed.")); 3012 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 3013 ("vnode already free")); 3014 VNASSERT(vp->v_holdcnt == 0, vp, 3015 ("vdropl: freeing when we shouldn't")); 3016 active = vp->v_iflag & VI_ACTIVE; 3017 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3018 vp->v_iflag &= ~VI_ACTIVE; 3019 mp = vp->v_mount; 3020 if (mp != NULL) { 3021 mtx_lock(&mp->mnt_listmtx); 3022 if (active) { 3023 TAILQ_REMOVE(&mp->mnt_activevnodelist, 3024 vp, v_actfreelist); 3025 mp->mnt_activevnodelistsize--; 3026 } 3027 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, 3028 vp, v_actfreelist); 3029 mp->mnt_tmpfreevnodelistsize++; 3030 vp->v_iflag |= VI_FREE; 3031 vp->v_mflag |= VMP_TMPMNTFREELIST; 3032 VI_UNLOCK(vp); 3033 if (mp->mnt_tmpfreevnodelistsize >= 3034 mnt_free_list_batch) 3035 vnlru_return_batch_locked(mp); 3036 mtx_unlock(&mp->mnt_listmtx); 3037 } else { 3038 VNASSERT(active == 0, vp, 3039 ("vdropl: active vnode not on per mount " 3040 "vnode list")); 3041 mtx_lock(&vnode_free_list_mtx); 3042 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 3043 v_actfreelist); 3044 freevnodes++; 3045 vp->v_iflag |= VI_FREE; 3046 VI_UNLOCK(vp); 3047 mtx_unlock(&vnode_free_list_mtx); 3048 } 3049 } else { 3050 VI_UNLOCK(vp); 3051 counter_u64_add(free_owe_inact, 1); 3052 } 3053 return; 3054 } 3055 /* 3056 * The vnode has been marked for destruction, so free it. 3057 * 3058 * The vnode will be returned to the zone where it will 3059 * normally remain until it is needed for another vnode. We 3060 * need to cleanup (or verify that the cleanup has already 3061 * been done) any residual data left from its current use 3062 * so as not to contaminate the freshly allocated vnode. 3063 */ 3064 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 3065 atomic_subtract_long(&numvnodes, 1); 3066 bo = &vp->v_bufobj; 3067 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 3068 ("cleaned vnode still on the free list.")); 3069 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 3070 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 3071 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 3072 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 3073 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 3074 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 3075 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 3076 ("clean blk trie not empty")); 3077 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 3078 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 3079 ("dirty blk trie not empty")); 3080 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 3081 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 3082 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 3083 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 3084 ("Dangling rangelock waiters")); 3085 VI_UNLOCK(vp); 3086 #ifdef MAC 3087 mac_vnode_destroy(vp); 3088 #endif 3089 if (vp->v_pollinfo != NULL) { 3090 destroy_vpollinfo(vp->v_pollinfo); 3091 vp->v_pollinfo = NULL; 3092 } 3093 #ifdef INVARIANTS 3094 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 3095 vp->v_op = NULL; 3096 #endif 3097 vp->v_mountedhere = NULL; 3098 vp->v_unpcb = NULL; 3099 vp->v_rdev = NULL; 3100 vp->v_fifoinfo = NULL; 3101 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 3102 vp->v_iflag = 0; 3103 vp->v_vflag = 0; 3104 bo->bo_flag = 0; 3105 uma_zfree(vnode_zone, vp); 3106 } 3107 3108 /* 3109 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3110 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3111 * OWEINACT tracks whether a vnode missed a call to inactive due to a 3112 * failed lock upgrade. 3113 */ 3114 void 3115 vinactive(struct vnode *vp, struct thread *td) 3116 { 3117 struct vm_object *obj; 3118 3119 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3120 ASSERT_VI_LOCKED(vp, "vinactive"); 3121 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3122 ("vinactive: recursed on VI_DOINGINACT")); 3123 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3124 vp->v_iflag |= VI_DOINGINACT; 3125 vp->v_iflag &= ~VI_OWEINACT; 3126 VI_UNLOCK(vp); 3127 /* 3128 * Before moving off the active list, we must be sure that any 3129 * modified pages are converted into the vnode's dirty 3130 * buffers, since these will no longer be checked once the 3131 * vnode is on the inactive list. 3132 * 3133 * The write-out of the dirty pages is asynchronous. At the 3134 * point that VOP_INACTIVE() is called, there could still be 3135 * pending I/O and dirty pages in the object. 3136 */ 3137 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3138 (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { 3139 VM_OBJECT_WLOCK(obj); 3140 vm_object_page_clean(obj, 0, 0, 0); 3141 VM_OBJECT_WUNLOCK(obj); 3142 } 3143 VOP_INACTIVE(vp, td); 3144 VI_LOCK(vp); 3145 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3146 ("vinactive: lost VI_DOINGINACT")); 3147 vp->v_iflag &= ~VI_DOINGINACT; 3148 } 3149 3150 /* 3151 * Remove any vnodes in the vnode table belonging to mount point mp. 3152 * 3153 * If FORCECLOSE is not specified, there should not be any active ones, 3154 * return error if any are found (nb: this is a user error, not a 3155 * system error). If FORCECLOSE is specified, detach any active vnodes 3156 * that are found. 3157 * 3158 * If WRITECLOSE is set, only flush out regular file vnodes open for 3159 * writing. 3160 * 3161 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3162 * 3163 * `rootrefs' specifies the base reference count for the root vnode 3164 * of this filesystem. The root vnode is considered busy if its 3165 * v_usecount exceeds this value. On a successful return, vflush(, td) 3166 * will call vrele() on the root vnode exactly rootrefs times. 3167 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3168 * be zero. 3169 */ 3170 #ifdef DIAGNOSTIC 3171 static int busyprt = 0; /* print out busy vnodes */ 3172 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3173 #endif 3174 3175 int 3176 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3177 { 3178 struct vnode *vp, *mvp, *rootvp = NULL; 3179 struct vattr vattr; 3180 int busy = 0, error; 3181 3182 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3183 rootrefs, flags); 3184 if (rootrefs > 0) { 3185 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3186 ("vflush: bad args")); 3187 /* 3188 * Get the filesystem root vnode. We can vput() it 3189 * immediately, since with rootrefs > 0, it won't go away. 3190 */ 3191 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3192 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3193 __func__, error); 3194 return (error); 3195 } 3196 vput(rootvp); 3197 } 3198 loop: 3199 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3200 vholdl(vp); 3201 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3202 if (error) { 3203 vdrop(vp); 3204 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3205 goto loop; 3206 } 3207 /* 3208 * Skip over a vnodes marked VV_SYSTEM. 3209 */ 3210 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3211 VOP_UNLOCK(vp, 0); 3212 vdrop(vp); 3213 continue; 3214 } 3215 /* 3216 * If WRITECLOSE is set, flush out unlinked but still open 3217 * files (even if open only for reading) and regular file 3218 * vnodes open for writing. 3219 */ 3220 if (flags & WRITECLOSE) { 3221 if (vp->v_object != NULL) { 3222 VM_OBJECT_WLOCK(vp->v_object); 3223 vm_object_page_clean(vp->v_object, 0, 0, 0); 3224 VM_OBJECT_WUNLOCK(vp->v_object); 3225 } 3226 error = VOP_FSYNC(vp, MNT_WAIT, td); 3227 if (error != 0) { 3228 VOP_UNLOCK(vp, 0); 3229 vdrop(vp); 3230 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3231 return (error); 3232 } 3233 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3234 VI_LOCK(vp); 3235 3236 if ((vp->v_type == VNON || 3237 (error == 0 && vattr.va_nlink > 0)) && 3238 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3239 VOP_UNLOCK(vp, 0); 3240 vdropl(vp); 3241 continue; 3242 } 3243 } else 3244 VI_LOCK(vp); 3245 /* 3246 * With v_usecount == 0, all we need to do is clear out the 3247 * vnode data structures and we are done. 3248 * 3249 * If FORCECLOSE is set, forcibly close the vnode. 3250 */ 3251 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3252 vgonel(vp); 3253 } else { 3254 busy++; 3255 #ifdef DIAGNOSTIC 3256 if (busyprt) 3257 vn_printf(vp, "vflush: busy vnode "); 3258 #endif 3259 } 3260 VOP_UNLOCK(vp, 0); 3261 vdropl(vp); 3262 } 3263 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3264 /* 3265 * If just the root vnode is busy, and if its refcount 3266 * is equal to `rootrefs', then go ahead and kill it. 3267 */ 3268 VI_LOCK(rootvp); 3269 KASSERT(busy > 0, ("vflush: not busy")); 3270 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3271 ("vflush: usecount %d < rootrefs %d", 3272 rootvp->v_usecount, rootrefs)); 3273 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3274 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3275 vgone(rootvp); 3276 VOP_UNLOCK(rootvp, 0); 3277 busy = 0; 3278 } else 3279 VI_UNLOCK(rootvp); 3280 } 3281 if (busy) { 3282 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3283 busy); 3284 return (EBUSY); 3285 } 3286 for (; rootrefs > 0; rootrefs--) 3287 vrele(rootvp); 3288 return (0); 3289 } 3290 3291 /* 3292 * Recycle an unused vnode to the front of the free list. 3293 */ 3294 int 3295 vrecycle(struct vnode *vp) 3296 { 3297 int recycled; 3298 3299 VI_LOCK(vp); 3300 recycled = vrecyclel(vp); 3301 VI_UNLOCK(vp); 3302 return (recycled); 3303 } 3304 3305 /* 3306 * vrecycle, with the vp interlock held. 3307 */ 3308 int 3309 vrecyclel(struct vnode *vp) 3310 { 3311 int recycled; 3312 3313 ASSERT_VOP_ELOCKED(vp, __func__); 3314 ASSERT_VI_LOCKED(vp, __func__); 3315 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3316 recycled = 0; 3317 if (vp->v_usecount == 0) { 3318 recycled = 1; 3319 vgonel(vp); 3320 } 3321 return (recycled); 3322 } 3323 3324 /* 3325 * Eliminate all activity associated with a vnode 3326 * in preparation for reuse. 3327 */ 3328 void 3329 vgone(struct vnode *vp) 3330 { 3331 VI_LOCK(vp); 3332 vgonel(vp); 3333 VI_UNLOCK(vp); 3334 } 3335 3336 static void 3337 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3338 struct vnode *lowervp __unused) 3339 { 3340 } 3341 3342 /* 3343 * Notify upper mounts about reclaimed or unlinked vnode. 3344 */ 3345 void 3346 vfs_notify_upper(struct vnode *vp, int event) 3347 { 3348 static struct vfsops vgonel_vfsops = { 3349 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3350 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3351 }; 3352 struct mount *mp, *ump, *mmp; 3353 3354 mp = vp->v_mount; 3355 if (mp == NULL) 3356 return; 3357 3358 MNT_ILOCK(mp); 3359 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3360 goto unlock; 3361 MNT_IUNLOCK(mp); 3362 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3363 mmp->mnt_op = &vgonel_vfsops; 3364 mmp->mnt_kern_flag |= MNTK_MARKER; 3365 MNT_ILOCK(mp); 3366 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3367 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3368 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3369 ump = TAILQ_NEXT(ump, mnt_upper_link); 3370 continue; 3371 } 3372 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3373 MNT_IUNLOCK(mp); 3374 switch (event) { 3375 case VFS_NOTIFY_UPPER_RECLAIM: 3376 VFS_RECLAIM_LOWERVP(ump, vp); 3377 break; 3378 case VFS_NOTIFY_UPPER_UNLINK: 3379 VFS_UNLINK_LOWERVP(ump, vp); 3380 break; 3381 default: 3382 KASSERT(0, ("invalid event %d", event)); 3383 break; 3384 } 3385 MNT_ILOCK(mp); 3386 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3387 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3388 } 3389 free(mmp, M_TEMP); 3390 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3391 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3392 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3393 wakeup(&mp->mnt_uppers); 3394 } 3395 unlock: 3396 MNT_IUNLOCK(mp); 3397 } 3398 3399 /* 3400 * vgone, with the vp interlock held. 3401 */ 3402 static void 3403 vgonel(struct vnode *vp) 3404 { 3405 struct thread *td; 3406 int oweinact; 3407 int active; 3408 struct mount *mp; 3409 3410 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3411 ASSERT_VI_LOCKED(vp, "vgonel"); 3412 VNASSERT(vp->v_holdcnt, vp, 3413 ("vgonel: vp %p has no reference.", vp)); 3414 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3415 td = curthread; 3416 3417 /* 3418 * Don't vgonel if we're already doomed. 3419 */ 3420 if (vp->v_iflag & VI_DOOMED) 3421 return; 3422 vp->v_iflag |= VI_DOOMED; 3423 3424 /* 3425 * Check to see if the vnode is in use. If so, we have to call 3426 * VOP_CLOSE() and VOP_INACTIVE(). 3427 */ 3428 active = vp->v_usecount; 3429 oweinact = (vp->v_iflag & VI_OWEINACT); 3430 VI_UNLOCK(vp); 3431 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3432 3433 /* 3434 * If purging an active vnode, it must be closed and 3435 * deactivated before being reclaimed. 3436 */ 3437 if (active) 3438 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3439 if (oweinact || active) { 3440 VI_LOCK(vp); 3441 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3442 vinactive(vp, td); 3443 VI_UNLOCK(vp); 3444 } 3445 if (vp->v_type == VSOCK) 3446 vfs_unp_reclaim(vp); 3447 3448 /* 3449 * Clean out any buffers associated with the vnode. 3450 * If the flush fails, just toss the buffers. 3451 */ 3452 mp = NULL; 3453 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3454 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3455 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3456 while (vinvalbuf(vp, 0, 0, 0) != 0) 3457 ; 3458 } 3459 3460 BO_LOCK(&vp->v_bufobj); 3461 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3462 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3463 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3464 vp->v_bufobj.bo_clean.bv_cnt == 0, 3465 ("vp %p bufobj not invalidated", vp)); 3466 3467 /* 3468 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate() 3469 * after the object's page queue is flushed. 3470 */ 3471 if (vp->v_bufobj.bo_object == NULL) 3472 vp->v_bufobj.bo_flag |= BO_DEAD; 3473 BO_UNLOCK(&vp->v_bufobj); 3474 3475 /* 3476 * Reclaim the vnode. 3477 */ 3478 if (VOP_RECLAIM(vp, td)) 3479 panic("vgone: cannot reclaim"); 3480 if (mp != NULL) 3481 vn_finished_secondary_write(mp); 3482 VNASSERT(vp->v_object == NULL, vp, 3483 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3484 /* 3485 * Clear the advisory locks and wake up waiting threads. 3486 */ 3487 (void)VOP_ADVLOCKPURGE(vp); 3488 vp->v_lockf = NULL; 3489 /* 3490 * Delete from old mount point vnode list. 3491 */ 3492 delmntque(vp); 3493 cache_purge(vp); 3494 /* 3495 * Done with purge, reset to the standard lock and invalidate 3496 * the vnode. 3497 */ 3498 VI_LOCK(vp); 3499 vp->v_vnlock = &vp->v_lock; 3500 vp->v_op = &dead_vnodeops; 3501 vp->v_tag = "none"; 3502 vp->v_type = VBAD; 3503 } 3504 3505 /* 3506 * Calculate the total number of references to a special device. 3507 */ 3508 int 3509 vcount(struct vnode *vp) 3510 { 3511 int count; 3512 3513 dev_lock(); 3514 count = vp->v_rdev->si_usecount; 3515 dev_unlock(); 3516 return (count); 3517 } 3518 3519 /* 3520 * Same as above, but using the struct cdev *as argument 3521 */ 3522 int 3523 count_dev(struct cdev *dev) 3524 { 3525 int count; 3526 3527 dev_lock(); 3528 count = dev->si_usecount; 3529 dev_unlock(); 3530 return(count); 3531 } 3532 3533 /* 3534 * Print out a description of a vnode. 3535 */ 3536 static char *typename[] = 3537 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3538 "VMARKER"}; 3539 3540 void 3541 vn_printf(struct vnode *vp, const char *fmt, ...) 3542 { 3543 va_list ap; 3544 char buf[256], buf2[16]; 3545 u_long flags; 3546 3547 va_start(ap, fmt); 3548 vprintf(fmt, ap); 3549 va_end(ap); 3550 printf("%p: ", (void *)vp); 3551 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3552 printf(" usecount %d, writecount %d, refcount %d", 3553 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 3554 switch (vp->v_type) { 3555 case VDIR: 3556 printf(" mountedhere %p\n", vp->v_mountedhere); 3557 break; 3558 case VCHR: 3559 printf(" rdev %p\n", vp->v_rdev); 3560 break; 3561 case VSOCK: 3562 printf(" socket %p\n", vp->v_unpcb); 3563 break; 3564 case VFIFO: 3565 printf(" fifoinfo %p\n", vp->v_fifoinfo); 3566 break; 3567 default: 3568 printf("\n"); 3569 break; 3570 } 3571 buf[0] = '\0'; 3572 buf[1] = '\0'; 3573 if (vp->v_vflag & VV_ROOT) 3574 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3575 if (vp->v_vflag & VV_ISTTY) 3576 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3577 if (vp->v_vflag & VV_NOSYNC) 3578 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3579 if (vp->v_vflag & VV_ETERNALDEV) 3580 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3581 if (vp->v_vflag & VV_CACHEDLABEL) 3582 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3583 if (vp->v_vflag & VV_COPYONWRITE) 3584 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3585 if (vp->v_vflag & VV_SYSTEM) 3586 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3587 if (vp->v_vflag & VV_PROCDEP) 3588 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3589 if (vp->v_vflag & VV_NOKNOTE) 3590 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3591 if (vp->v_vflag & VV_DELETED) 3592 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3593 if (vp->v_vflag & VV_MD) 3594 strlcat(buf, "|VV_MD", sizeof(buf)); 3595 if (vp->v_vflag & VV_FORCEINSMQ) 3596 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3597 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3598 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3599 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3600 if (flags != 0) { 3601 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3602 strlcat(buf, buf2, sizeof(buf)); 3603 } 3604 if (vp->v_iflag & VI_MOUNT) 3605 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3606 if (vp->v_iflag & VI_DOOMED) 3607 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 3608 if (vp->v_iflag & VI_FREE) 3609 strlcat(buf, "|VI_FREE", sizeof(buf)); 3610 if (vp->v_iflag & VI_ACTIVE) 3611 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3612 if (vp->v_iflag & VI_DOINGINACT) 3613 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3614 if (vp->v_iflag & VI_OWEINACT) 3615 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3616 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | 3617 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT); 3618 if (flags != 0) { 3619 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3620 strlcat(buf, buf2, sizeof(buf)); 3621 } 3622 printf(" flags (%s)\n", buf + 1); 3623 if (mtx_owned(VI_MTX(vp))) 3624 printf(" VI_LOCKed"); 3625 if (vp->v_object != NULL) 3626 printf(" v_object %p ref %d pages %d " 3627 "cleanbuf %d dirtybuf %d\n", 3628 vp->v_object, vp->v_object->ref_count, 3629 vp->v_object->resident_page_count, 3630 vp->v_bufobj.bo_clean.bv_cnt, 3631 vp->v_bufobj.bo_dirty.bv_cnt); 3632 printf(" "); 3633 lockmgr_printinfo(vp->v_vnlock); 3634 if (vp->v_data != NULL) 3635 VOP_PRINT(vp); 3636 } 3637 3638 #ifdef DDB 3639 /* 3640 * List all of the locked vnodes in the system. 3641 * Called when debugging the kernel. 3642 */ 3643 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3644 { 3645 struct mount *mp; 3646 struct vnode *vp; 3647 3648 /* 3649 * Note: because this is DDB, we can't obey the locking semantics 3650 * for these structures, which means we could catch an inconsistent 3651 * state and dereference a nasty pointer. Not much to be done 3652 * about that. 3653 */ 3654 db_printf("Locked vnodes\n"); 3655 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3656 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3657 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3658 vn_printf(vp, "vnode "); 3659 } 3660 } 3661 } 3662 3663 /* 3664 * Show details about the given vnode. 3665 */ 3666 DB_SHOW_COMMAND(vnode, db_show_vnode) 3667 { 3668 struct vnode *vp; 3669 3670 if (!have_addr) 3671 return; 3672 vp = (struct vnode *)addr; 3673 vn_printf(vp, "vnode "); 3674 } 3675 3676 /* 3677 * Show details about the given mount point. 3678 */ 3679 DB_SHOW_COMMAND(mount, db_show_mount) 3680 { 3681 struct mount *mp; 3682 struct vfsopt *opt; 3683 struct statfs *sp; 3684 struct vnode *vp; 3685 char buf[512]; 3686 uint64_t mflags; 3687 u_int flags; 3688 3689 if (!have_addr) { 3690 /* No address given, print short info about all mount points. */ 3691 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3692 db_printf("%p %s on %s (%s)\n", mp, 3693 mp->mnt_stat.f_mntfromname, 3694 mp->mnt_stat.f_mntonname, 3695 mp->mnt_stat.f_fstypename); 3696 if (db_pager_quit) 3697 break; 3698 } 3699 db_printf("\nMore info: show mount <addr>\n"); 3700 return; 3701 } 3702 3703 mp = (struct mount *)addr; 3704 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3705 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3706 3707 buf[0] = '\0'; 3708 mflags = mp->mnt_flag; 3709 #define MNT_FLAG(flag) do { \ 3710 if (mflags & (flag)) { \ 3711 if (buf[0] != '\0') \ 3712 strlcat(buf, ", ", sizeof(buf)); \ 3713 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3714 mflags &= ~(flag); \ 3715 } \ 3716 } while (0) 3717 MNT_FLAG(MNT_RDONLY); 3718 MNT_FLAG(MNT_SYNCHRONOUS); 3719 MNT_FLAG(MNT_NOEXEC); 3720 MNT_FLAG(MNT_NOSUID); 3721 MNT_FLAG(MNT_NFS4ACLS); 3722 MNT_FLAG(MNT_UNION); 3723 MNT_FLAG(MNT_ASYNC); 3724 MNT_FLAG(MNT_SUIDDIR); 3725 MNT_FLAG(MNT_SOFTDEP); 3726 MNT_FLAG(MNT_NOSYMFOLLOW); 3727 MNT_FLAG(MNT_GJOURNAL); 3728 MNT_FLAG(MNT_MULTILABEL); 3729 MNT_FLAG(MNT_ACLS); 3730 MNT_FLAG(MNT_NOATIME); 3731 MNT_FLAG(MNT_NOCLUSTERR); 3732 MNT_FLAG(MNT_NOCLUSTERW); 3733 MNT_FLAG(MNT_SUJ); 3734 MNT_FLAG(MNT_EXRDONLY); 3735 MNT_FLAG(MNT_EXPORTED); 3736 MNT_FLAG(MNT_DEFEXPORTED); 3737 MNT_FLAG(MNT_EXPORTANON); 3738 MNT_FLAG(MNT_EXKERB); 3739 MNT_FLAG(MNT_EXPUBLIC); 3740 MNT_FLAG(MNT_LOCAL); 3741 MNT_FLAG(MNT_QUOTA); 3742 MNT_FLAG(MNT_ROOTFS); 3743 MNT_FLAG(MNT_USER); 3744 MNT_FLAG(MNT_IGNORE); 3745 MNT_FLAG(MNT_UPDATE); 3746 MNT_FLAG(MNT_DELEXPORT); 3747 MNT_FLAG(MNT_RELOAD); 3748 MNT_FLAG(MNT_FORCE); 3749 MNT_FLAG(MNT_SNAPSHOT); 3750 MNT_FLAG(MNT_BYFSID); 3751 #undef MNT_FLAG 3752 if (mflags != 0) { 3753 if (buf[0] != '\0') 3754 strlcat(buf, ", ", sizeof(buf)); 3755 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3756 "0x%016jx", mflags); 3757 } 3758 db_printf(" mnt_flag = %s\n", buf); 3759 3760 buf[0] = '\0'; 3761 flags = mp->mnt_kern_flag; 3762 #define MNT_KERN_FLAG(flag) do { \ 3763 if (flags & (flag)) { \ 3764 if (buf[0] != '\0') \ 3765 strlcat(buf, ", ", sizeof(buf)); \ 3766 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3767 flags &= ~(flag); \ 3768 } \ 3769 } while (0) 3770 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3771 MNT_KERN_FLAG(MNTK_ASYNC); 3772 MNT_KERN_FLAG(MNTK_SOFTDEP); 3773 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 3774 MNT_KERN_FLAG(MNTK_DRAINING); 3775 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3776 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3777 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3778 MNT_KERN_FLAG(MNTK_NO_IOPF); 3779 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3780 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3781 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3782 MNT_KERN_FLAG(MNTK_MARKER); 3783 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3784 MNT_KERN_FLAG(MNTK_NOASYNC); 3785 MNT_KERN_FLAG(MNTK_UNMOUNT); 3786 MNT_KERN_FLAG(MNTK_MWAIT); 3787 MNT_KERN_FLAG(MNTK_SUSPEND); 3788 MNT_KERN_FLAG(MNTK_SUSPEND2); 3789 MNT_KERN_FLAG(MNTK_SUSPENDED); 3790 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3791 MNT_KERN_FLAG(MNTK_NOKNOTE); 3792 #undef MNT_KERN_FLAG 3793 if (flags != 0) { 3794 if (buf[0] != '\0') 3795 strlcat(buf, ", ", sizeof(buf)); 3796 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3797 "0x%08x", flags); 3798 } 3799 db_printf(" mnt_kern_flag = %s\n", buf); 3800 3801 db_printf(" mnt_opt = "); 3802 opt = TAILQ_FIRST(mp->mnt_opt); 3803 if (opt != NULL) { 3804 db_printf("%s", opt->name); 3805 opt = TAILQ_NEXT(opt, link); 3806 while (opt != NULL) { 3807 db_printf(", %s", opt->name); 3808 opt = TAILQ_NEXT(opt, link); 3809 } 3810 } 3811 db_printf("\n"); 3812 3813 sp = &mp->mnt_stat; 3814 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3815 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3816 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3817 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3818 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3819 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 3820 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 3821 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 3822 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 3823 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 3824 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 3825 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 3826 3827 db_printf(" mnt_cred = { uid=%u ruid=%u", 3828 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 3829 if (jailed(mp->mnt_cred)) 3830 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 3831 db_printf(" }\n"); 3832 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 3833 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 3834 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 3835 db_printf(" mnt_activevnodelistsize = %d\n", 3836 mp->mnt_activevnodelistsize); 3837 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 3838 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 3839 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 3840 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 3841 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); 3842 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 3843 db_printf(" mnt_secondary_accwrites = %d\n", 3844 mp->mnt_secondary_accwrites); 3845 db_printf(" mnt_gjprovider = %s\n", 3846 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 3847 3848 db_printf("\n\nList of active vnodes\n"); 3849 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 3850 if (vp->v_type != VMARKER) { 3851 vn_printf(vp, "vnode "); 3852 if (db_pager_quit) 3853 break; 3854 } 3855 } 3856 db_printf("\n\nList of inactive vnodes\n"); 3857 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3858 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 3859 vn_printf(vp, "vnode "); 3860 if (db_pager_quit) 3861 break; 3862 } 3863 } 3864 } 3865 #endif /* DDB */ 3866 3867 /* 3868 * Fill in a struct xvfsconf based on a struct vfsconf. 3869 */ 3870 static int 3871 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 3872 { 3873 struct xvfsconf xvfsp; 3874 3875 bzero(&xvfsp, sizeof(xvfsp)); 3876 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3877 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3878 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3879 xvfsp.vfc_flags = vfsp->vfc_flags; 3880 /* 3881 * These are unused in userland, we keep them 3882 * to not break binary compatibility. 3883 */ 3884 xvfsp.vfc_vfsops = NULL; 3885 xvfsp.vfc_next = NULL; 3886 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3887 } 3888 3889 #ifdef COMPAT_FREEBSD32 3890 struct xvfsconf32 { 3891 uint32_t vfc_vfsops; 3892 char vfc_name[MFSNAMELEN]; 3893 int32_t vfc_typenum; 3894 int32_t vfc_refcount; 3895 int32_t vfc_flags; 3896 uint32_t vfc_next; 3897 }; 3898 3899 static int 3900 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 3901 { 3902 struct xvfsconf32 xvfsp; 3903 3904 bzero(&xvfsp, sizeof(xvfsp)); 3905 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3906 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3907 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3908 xvfsp.vfc_flags = vfsp->vfc_flags; 3909 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3910 } 3911 #endif 3912 3913 /* 3914 * Top level filesystem related information gathering. 3915 */ 3916 static int 3917 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3918 { 3919 struct vfsconf *vfsp; 3920 int error; 3921 3922 error = 0; 3923 vfsconf_slock(); 3924 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3925 #ifdef COMPAT_FREEBSD32 3926 if (req->flags & SCTL_MASK32) 3927 error = vfsconf2x32(req, vfsp); 3928 else 3929 #endif 3930 error = vfsconf2x(req, vfsp); 3931 if (error) 3932 break; 3933 } 3934 vfsconf_sunlock(); 3935 return (error); 3936 } 3937 3938 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 3939 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 3940 "S,xvfsconf", "List of all configured filesystems"); 3941 3942 #ifndef BURN_BRIDGES 3943 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3944 3945 static int 3946 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3947 { 3948 int *name = (int *)arg1 - 1; /* XXX */ 3949 u_int namelen = arg2 + 1; /* XXX */ 3950 struct vfsconf *vfsp; 3951 3952 log(LOG_WARNING, "userland calling deprecated sysctl, " 3953 "please rebuild world\n"); 3954 3955 #if 1 || defined(COMPAT_PRELITE2) 3956 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3957 if (namelen == 1) 3958 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3959 #endif 3960 3961 switch (name[1]) { 3962 case VFS_MAXTYPENUM: 3963 if (namelen != 2) 3964 return (ENOTDIR); 3965 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3966 case VFS_CONF: 3967 if (namelen != 3) 3968 return (ENOTDIR); /* overloaded */ 3969 vfsconf_slock(); 3970 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3971 if (vfsp->vfc_typenum == name[2]) 3972 break; 3973 } 3974 vfsconf_sunlock(); 3975 if (vfsp == NULL) 3976 return (EOPNOTSUPP); 3977 #ifdef COMPAT_FREEBSD32 3978 if (req->flags & SCTL_MASK32) 3979 return (vfsconf2x32(req, vfsp)); 3980 else 3981 #endif 3982 return (vfsconf2x(req, vfsp)); 3983 } 3984 return (EOPNOTSUPP); 3985 } 3986 3987 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 3988 CTLFLAG_MPSAFE, vfs_sysctl, 3989 "Generic filesystem"); 3990 3991 #if 1 || defined(COMPAT_PRELITE2) 3992 3993 static int 3994 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3995 { 3996 int error; 3997 struct vfsconf *vfsp; 3998 struct ovfsconf ovfs; 3999 4000 vfsconf_slock(); 4001 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4002 bzero(&ovfs, sizeof(ovfs)); 4003 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4004 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4005 ovfs.vfc_index = vfsp->vfc_typenum; 4006 ovfs.vfc_refcount = vfsp->vfc_refcount; 4007 ovfs.vfc_flags = vfsp->vfc_flags; 4008 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4009 if (error != 0) { 4010 vfsconf_sunlock(); 4011 return (error); 4012 } 4013 } 4014 vfsconf_sunlock(); 4015 return (0); 4016 } 4017 4018 #endif /* 1 || COMPAT_PRELITE2 */ 4019 #endif /* !BURN_BRIDGES */ 4020 4021 #define KINFO_VNODESLOP 10 4022 #ifdef notyet 4023 /* 4024 * Dump vnode list (via sysctl). 4025 */ 4026 /* ARGSUSED */ 4027 static int 4028 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4029 { 4030 struct xvnode *xvn; 4031 struct mount *mp; 4032 struct vnode *vp; 4033 int error, len, n; 4034 4035 /* 4036 * Stale numvnodes access is not fatal here. 4037 */ 4038 req->lock = 0; 4039 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4040 if (!req->oldptr) 4041 /* Make an estimate */ 4042 return (SYSCTL_OUT(req, 0, len)); 4043 4044 error = sysctl_wire_old_buffer(req, 0); 4045 if (error != 0) 4046 return (error); 4047 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4048 n = 0; 4049 mtx_lock(&mountlist_mtx); 4050 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4051 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4052 continue; 4053 MNT_ILOCK(mp); 4054 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4055 if (n == len) 4056 break; 4057 vref(vp); 4058 xvn[n].xv_size = sizeof *xvn; 4059 xvn[n].xv_vnode = vp; 4060 xvn[n].xv_id = 0; /* XXX compat */ 4061 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4062 XV_COPY(usecount); 4063 XV_COPY(writecount); 4064 XV_COPY(holdcnt); 4065 XV_COPY(mount); 4066 XV_COPY(numoutput); 4067 XV_COPY(type); 4068 #undef XV_COPY 4069 xvn[n].xv_flag = vp->v_vflag; 4070 4071 switch (vp->v_type) { 4072 case VREG: 4073 case VDIR: 4074 case VLNK: 4075 break; 4076 case VBLK: 4077 case VCHR: 4078 if (vp->v_rdev == NULL) { 4079 vrele(vp); 4080 continue; 4081 } 4082 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4083 break; 4084 case VSOCK: 4085 xvn[n].xv_socket = vp->v_socket; 4086 break; 4087 case VFIFO: 4088 xvn[n].xv_fifo = vp->v_fifoinfo; 4089 break; 4090 case VNON: 4091 case VBAD: 4092 default: 4093 /* shouldn't happen? */ 4094 vrele(vp); 4095 continue; 4096 } 4097 vrele(vp); 4098 ++n; 4099 } 4100 MNT_IUNLOCK(mp); 4101 mtx_lock(&mountlist_mtx); 4102 vfs_unbusy(mp); 4103 if (n == len) 4104 break; 4105 } 4106 mtx_unlock(&mountlist_mtx); 4107 4108 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4109 free(xvn, M_TEMP); 4110 return (error); 4111 } 4112 4113 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4114 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4115 ""); 4116 #endif 4117 4118 static void 4119 unmount_or_warn(struct mount *mp) 4120 { 4121 int error; 4122 4123 error = dounmount(mp, MNT_FORCE, curthread); 4124 if (error != 0) { 4125 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4126 if (error == EBUSY) 4127 printf("BUSY)\n"); 4128 else 4129 printf("%d)\n", error); 4130 } 4131 } 4132 4133 /* 4134 * Unmount all filesystems. The list is traversed in reverse order 4135 * of mounting to avoid dependencies. 4136 */ 4137 void 4138 vfs_unmountall(void) 4139 { 4140 struct mount *mp, *tmp; 4141 4142 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4143 4144 /* 4145 * Since this only runs when rebooting, it is not interlocked. 4146 */ 4147 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4148 vfs_ref(mp); 4149 4150 /* 4151 * Forcibly unmounting "/dev" before "/" would prevent clean 4152 * unmount of the latter. 4153 */ 4154 if (mp == rootdevmp) 4155 continue; 4156 4157 unmount_or_warn(mp); 4158 } 4159 4160 if (rootdevmp != NULL) 4161 unmount_or_warn(rootdevmp); 4162 } 4163 4164 /* 4165 * perform msync on all vnodes under a mount point 4166 * the mount point must be locked. 4167 */ 4168 void 4169 vfs_msync(struct mount *mp, int flags) 4170 { 4171 struct vnode *vp, *mvp; 4172 struct vm_object *obj; 4173 4174 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4175 4176 vnlru_return_batch(mp); 4177 4178 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 4179 obj = vp->v_object; 4180 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 4181 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 4182 if (!vget(vp, 4183 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 4184 curthread)) { 4185 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 4186 vput(vp); 4187 continue; 4188 } 4189 4190 obj = vp->v_object; 4191 if (obj != NULL) { 4192 VM_OBJECT_WLOCK(obj); 4193 vm_object_page_clean(obj, 0, 0, 4194 flags == MNT_WAIT ? 4195 OBJPC_SYNC : OBJPC_NOSYNC); 4196 VM_OBJECT_WUNLOCK(obj); 4197 } 4198 vput(vp); 4199 } 4200 } else 4201 VI_UNLOCK(vp); 4202 } 4203 } 4204 4205 static void 4206 destroy_vpollinfo_free(struct vpollinfo *vi) 4207 { 4208 4209 knlist_destroy(&vi->vpi_selinfo.si_note); 4210 mtx_destroy(&vi->vpi_lock); 4211 uma_zfree(vnodepoll_zone, vi); 4212 } 4213 4214 static void 4215 destroy_vpollinfo(struct vpollinfo *vi) 4216 { 4217 4218 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4219 seldrain(&vi->vpi_selinfo); 4220 destroy_vpollinfo_free(vi); 4221 } 4222 4223 /* 4224 * Initialize per-vnode helper structure to hold poll-related state. 4225 */ 4226 void 4227 v_addpollinfo(struct vnode *vp) 4228 { 4229 struct vpollinfo *vi; 4230 4231 if (vp->v_pollinfo != NULL) 4232 return; 4233 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4234 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4235 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4236 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4237 VI_LOCK(vp); 4238 if (vp->v_pollinfo != NULL) { 4239 VI_UNLOCK(vp); 4240 destroy_vpollinfo_free(vi); 4241 return; 4242 } 4243 vp->v_pollinfo = vi; 4244 VI_UNLOCK(vp); 4245 } 4246 4247 /* 4248 * Record a process's interest in events which might happen to 4249 * a vnode. Because poll uses the historic select-style interface 4250 * internally, this routine serves as both the ``check for any 4251 * pending events'' and the ``record my interest in future events'' 4252 * functions. (These are done together, while the lock is held, 4253 * to avoid race conditions.) 4254 */ 4255 int 4256 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4257 { 4258 4259 v_addpollinfo(vp); 4260 mtx_lock(&vp->v_pollinfo->vpi_lock); 4261 if (vp->v_pollinfo->vpi_revents & events) { 4262 /* 4263 * This leaves events we are not interested 4264 * in available for the other process which 4265 * which presumably had requested them 4266 * (otherwise they would never have been 4267 * recorded). 4268 */ 4269 events &= vp->v_pollinfo->vpi_revents; 4270 vp->v_pollinfo->vpi_revents &= ~events; 4271 4272 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4273 return (events); 4274 } 4275 vp->v_pollinfo->vpi_events |= events; 4276 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4277 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4278 return (0); 4279 } 4280 4281 /* 4282 * Routine to create and manage a filesystem syncer vnode. 4283 */ 4284 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4285 static int sync_fsync(struct vop_fsync_args *); 4286 static int sync_inactive(struct vop_inactive_args *); 4287 static int sync_reclaim(struct vop_reclaim_args *); 4288 4289 static struct vop_vector sync_vnodeops = { 4290 .vop_bypass = VOP_EOPNOTSUPP, 4291 .vop_close = sync_close, /* close */ 4292 .vop_fsync = sync_fsync, /* fsync */ 4293 .vop_inactive = sync_inactive, /* inactive */ 4294 .vop_reclaim = sync_reclaim, /* reclaim */ 4295 .vop_lock1 = vop_stdlock, /* lock */ 4296 .vop_unlock = vop_stdunlock, /* unlock */ 4297 .vop_islocked = vop_stdislocked, /* islocked */ 4298 }; 4299 4300 /* 4301 * Create a new filesystem syncer vnode for the specified mount point. 4302 */ 4303 void 4304 vfs_allocate_syncvnode(struct mount *mp) 4305 { 4306 struct vnode *vp; 4307 struct bufobj *bo; 4308 static long start, incr, next; 4309 int error; 4310 4311 /* Allocate a new vnode */ 4312 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4313 if (error != 0) 4314 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4315 vp->v_type = VNON; 4316 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4317 vp->v_vflag |= VV_FORCEINSMQ; 4318 error = insmntque(vp, mp); 4319 if (error != 0) 4320 panic("vfs_allocate_syncvnode: insmntque() failed"); 4321 vp->v_vflag &= ~VV_FORCEINSMQ; 4322 VOP_UNLOCK(vp, 0); 4323 /* 4324 * Place the vnode onto the syncer worklist. We attempt to 4325 * scatter them about on the list so that they will go off 4326 * at evenly distributed times even if all the filesystems 4327 * are mounted at once. 4328 */ 4329 next += incr; 4330 if (next == 0 || next > syncer_maxdelay) { 4331 start /= 2; 4332 incr /= 2; 4333 if (start == 0) { 4334 start = syncer_maxdelay / 2; 4335 incr = syncer_maxdelay; 4336 } 4337 next = start; 4338 } 4339 bo = &vp->v_bufobj; 4340 BO_LOCK(bo); 4341 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4342 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4343 mtx_lock(&sync_mtx); 4344 sync_vnode_count++; 4345 if (mp->mnt_syncer == NULL) { 4346 mp->mnt_syncer = vp; 4347 vp = NULL; 4348 } 4349 mtx_unlock(&sync_mtx); 4350 BO_UNLOCK(bo); 4351 if (vp != NULL) { 4352 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4353 vgone(vp); 4354 vput(vp); 4355 } 4356 } 4357 4358 void 4359 vfs_deallocate_syncvnode(struct mount *mp) 4360 { 4361 struct vnode *vp; 4362 4363 mtx_lock(&sync_mtx); 4364 vp = mp->mnt_syncer; 4365 if (vp != NULL) 4366 mp->mnt_syncer = NULL; 4367 mtx_unlock(&sync_mtx); 4368 if (vp != NULL) 4369 vrele(vp); 4370 } 4371 4372 /* 4373 * Do a lazy sync of the filesystem. 4374 */ 4375 static int 4376 sync_fsync(struct vop_fsync_args *ap) 4377 { 4378 struct vnode *syncvp = ap->a_vp; 4379 struct mount *mp = syncvp->v_mount; 4380 int error, save; 4381 struct bufobj *bo; 4382 4383 /* 4384 * We only need to do something if this is a lazy evaluation. 4385 */ 4386 if (ap->a_waitfor != MNT_LAZY) 4387 return (0); 4388 4389 /* 4390 * Move ourselves to the back of the sync list. 4391 */ 4392 bo = &syncvp->v_bufobj; 4393 BO_LOCK(bo); 4394 vn_syncer_add_to_worklist(bo, syncdelay); 4395 BO_UNLOCK(bo); 4396 4397 /* 4398 * Walk the list of vnodes pushing all that are dirty and 4399 * not already on the sync list. 4400 */ 4401 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4402 return (0); 4403 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4404 vfs_unbusy(mp); 4405 return (0); 4406 } 4407 save = curthread_pflags_set(TDP_SYNCIO); 4408 vfs_msync(mp, MNT_NOWAIT); 4409 error = VFS_SYNC(mp, MNT_LAZY); 4410 curthread_pflags_restore(save); 4411 vn_finished_write(mp); 4412 vfs_unbusy(mp); 4413 return (error); 4414 } 4415 4416 /* 4417 * The syncer vnode is no referenced. 4418 */ 4419 static int 4420 sync_inactive(struct vop_inactive_args *ap) 4421 { 4422 4423 vgone(ap->a_vp); 4424 return (0); 4425 } 4426 4427 /* 4428 * The syncer vnode is no longer needed and is being decommissioned. 4429 * 4430 * Modifications to the worklist must be protected by sync_mtx. 4431 */ 4432 static int 4433 sync_reclaim(struct vop_reclaim_args *ap) 4434 { 4435 struct vnode *vp = ap->a_vp; 4436 struct bufobj *bo; 4437 4438 bo = &vp->v_bufobj; 4439 BO_LOCK(bo); 4440 mtx_lock(&sync_mtx); 4441 if (vp->v_mount->mnt_syncer == vp) 4442 vp->v_mount->mnt_syncer = NULL; 4443 if (bo->bo_flag & BO_ONWORKLST) { 4444 LIST_REMOVE(bo, bo_synclist); 4445 syncer_worklist_len--; 4446 sync_vnode_count--; 4447 bo->bo_flag &= ~BO_ONWORKLST; 4448 } 4449 mtx_unlock(&sync_mtx); 4450 BO_UNLOCK(bo); 4451 4452 return (0); 4453 } 4454 4455 /* 4456 * Check if vnode represents a disk device 4457 */ 4458 int 4459 vn_isdisk(struct vnode *vp, int *errp) 4460 { 4461 int error; 4462 4463 if (vp->v_type != VCHR) { 4464 error = ENOTBLK; 4465 goto out; 4466 } 4467 error = 0; 4468 dev_lock(); 4469 if (vp->v_rdev == NULL) 4470 error = ENXIO; 4471 else if (vp->v_rdev->si_devsw == NULL) 4472 error = ENXIO; 4473 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4474 error = ENOTBLK; 4475 dev_unlock(); 4476 out: 4477 if (errp != NULL) 4478 *errp = error; 4479 return (error == 0); 4480 } 4481 4482 /* 4483 * Common filesystem object access control check routine. Accepts a 4484 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4485 * and optional call-by-reference privused argument allowing vaccess() 4486 * to indicate to the caller whether privilege was used to satisfy the 4487 * request (obsoleted). Returns 0 on success, or an errno on failure. 4488 */ 4489 int 4490 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4491 accmode_t accmode, struct ucred *cred, int *privused) 4492 { 4493 accmode_t dac_granted; 4494 accmode_t priv_granted; 4495 4496 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4497 ("invalid bit in accmode")); 4498 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4499 ("VAPPEND without VWRITE")); 4500 4501 /* 4502 * Look for a normal, non-privileged way to access the file/directory 4503 * as requested. If it exists, go with that. 4504 */ 4505 4506 if (privused != NULL) 4507 *privused = 0; 4508 4509 dac_granted = 0; 4510 4511 /* Check the owner. */ 4512 if (cred->cr_uid == file_uid) { 4513 dac_granted |= VADMIN; 4514 if (file_mode & S_IXUSR) 4515 dac_granted |= VEXEC; 4516 if (file_mode & S_IRUSR) 4517 dac_granted |= VREAD; 4518 if (file_mode & S_IWUSR) 4519 dac_granted |= (VWRITE | VAPPEND); 4520 4521 if ((accmode & dac_granted) == accmode) 4522 return (0); 4523 4524 goto privcheck; 4525 } 4526 4527 /* Otherwise, check the groups (first match) */ 4528 if (groupmember(file_gid, cred)) { 4529 if (file_mode & S_IXGRP) 4530 dac_granted |= VEXEC; 4531 if (file_mode & S_IRGRP) 4532 dac_granted |= VREAD; 4533 if (file_mode & S_IWGRP) 4534 dac_granted |= (VWRITE | VAPPEND); 4535 4536 if ((accmode & dac_granted) == accmode) 4537 return (0); 4538 4539 goto privcheck; 4540 } 4541 4542 /* Otherwise, check everyone else. */ 4543 if (file_mode & S_IXOTH) 4544 dac_granted |= VEXEC; 4545 if (file_mode & S_IROTH) 4546 dac_granted |= VREAD; 4547 if (file_mode & S_IWOTH) 4548 dac_granted |= (VWRITE | VAPPEND); 4549 if ((accmode & dac_granted) == accmode) 4550 return (0); 4551 4552 privcheck: 4553 /* 4554 * Build a privilege mask to determine if the set of privileges 4555 * satisfies the requirements when combined with the granted mask 4556 * from above. For each privilege, if the privilege is required, 4557 * bitwise or the request type onto the priv_granted mask. 4558 */ 4559 priv_granted = 0; 4560 4561 if (type == VDIR) { 4562 /* 4563 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4564 * requests, instead of PRIV_VFS_EXEC. 4565 */ 4566 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4567 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 4568 priv_granted |= VEXEC; 4569 } else { 4570 /* 4571 * Ensure that at least one execute bit is on. Otherwise, 4572 * a privileged user will always succeed, and we don't want 4573 * this to happen unless the file really is executable. 4574 */ 4575 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4576 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4577 !priv_check_cred(cred, PRIV_VFS_EXEC)) 4578 priv_granted |= VEXEC; 4579 } 4580 4581 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4582 !priv_check_cred(cred, PRIV_VFS_READ)) 4583 priv_granted |= VREAD; 4584 4585 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4586 !priv_check_cred(cred, PRIV_VFS_WRITE)) 4587 priv_granted |= (VWRITE | VAPPEND); 4588 4589 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4590 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 4591 priv_granted |= VADMIN; 4592 4593 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4594 /* XXX audit: privilege used */ 4595 if (privused != NULL) 4596 *privused = 1; 4597 return (0); 4598 } 4599 4600 return ((accmode & VADMIN) ? EPERM : EACCES); 4601 } 4602 4603 /* 4604 * Credential check based on process requesting service, and per-attribute 4605 * permissions. 4606 */ 4607 int 4608 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4609 struct thread *td, accmode_t accmode) 4610 { 4611 4612 /* 4613 * Kernel-invoked always succeeds. 4614 */ 4615 if (cred == NOCRED) 4616 return (0); 4617 4618 /* 4619 * Do not allow privileged processes in jail to directly manipulate 4620 * system attributes. 4621 */ 4622 switch (attrnamespace) { 4623 case EXTATTR_NAMESPACE_SYSTEM: 4624 /* Potentially should be: return (EPERM); */ 4625 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 4626 case EXTATTR_NAMESPACE_USER: 4627 return (VOP_ACCESS(vp, accmode, cred, td)); 4628 default: 4629 return (EPERM); 4630 } 4631 } 4632 4633 #ifdef DEBUG_VFS_LOCKS 4634 /* 4635 * This only exists to suppress warnings from unlocked specfs accesses. It is 4636 * no longer ok to have an unlocked VFS. 4637 */ 4638 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4639 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4640 4641 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4642 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4643 "Drop into debugger on lock violation"); 4644 4645 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4646 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4647 0, "Check for interlock across VOPs"); 4648 4649 int vfs_badlock_print = 1; /* Print lock violations. */ 4650 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4651 0, "Print lock violations"); 4652 4653 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 4654 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 4655 0, "Print vnode details on lock violations"); 4656 4657 #ifdef KDB 4658 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4659 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4660 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4661 #endif 4662 4663 static void 4664 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4665 { 4666 4667 #ifdef KDB 4668 if (vfs_badlock_backtrace) 4669 kdb_backtrace(); 4670 #endif 4671 if (vfs_badlock_vnode) 4672 vn_printf(vp, "vnode "); 4673 if (vfs_badlock_print) 4674 printf("%s: %p %s\n", str, (void *)vp, msg); 4675 if (vfs_badlock_ddb) 4676 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4677 } 4678 4679 void 4680 assert_vi_locked(struct vnode *vp, const char *str) 4681 { 4682 4683 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4684 vfs_badlock("interlock is not locked but should be", str, vp); 4685 } 4686 4687 void 4688 assert_vi_unlocked(struct vnode *vp, const char *str) 4689 { 4690 4691 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4692 vfs_badlock("interlock is locked but should not be", str, vp); 4693 } 4694 4695 void 4696 assert_vop_locked(struct vnode *vp, const char *str) 4697 { 4698 int locked; 4699 4700 if (!IGNORE_LOCK(vp)) { 4701 locked = VOP_ISLOCKED(vp); 4702 if (locked == 0 || locked == LK_EXCLOTHER) 4703 vfs_badlock("is not locked but should be", str, vp); 4704 } 4705 } 4706 4707 void 4708 assert_vop_unlocked(struct vnode *vp, const char *str) 4709 { 4710 4711 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4712 vfs_badlock("is locked but should not be", str, vp); 4713 } 4714 4715 void 4716 assert_vop_elocked(struct vnode *vp, const char *str) 4717 { 4718 4719 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4720 vfs_badlock("is not exclusive locked but should be", str, vp); 4721 } 4722 #endif /* DEBUG_VFS_LOCKS */ 4723 4724 void 4725 vop_rename_fail(struct vop_rename_args *ap) 4726 { 4727 4728 if (ap->a_tvp != NULL) 4729 vput(ap->a_tvp); 4730 if (ap->a_tdvp == ap->a_tvp) 4731 vrele(ap->a_tdvp); 4732 else 4733 vput(ap->a_tdvp); 4734 vrele(ap->a_fdvp); 4735 vrele(ap->a_fvp); 4736 } 4737 4738 void 4739 vop_rename_pre(void *ap) 4740 { 4741 struct vop_rename_args *a = ap; 4742 4743 #ifdef DEBUG_VFS_LOCKS 4744 if (a->a_tvp) 4745 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4746 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4747 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4748 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4749 4750 /* Check the source (from). */ 4751 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4752 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4753 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4754 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4755 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4756 4757 /* Check the target. */ 4758 if (a->a_tvp) 4759 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4760 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4761 #endif 4762 if (a->a_tdvp != a->a_fdvp) 4763 vhold(a->a_fdvp); 4764 if (a->a_tvp != a->a_fvp) 4765 vhold(a->a_fvp); 4766 vhold(a->a_tdvp); 4767 if (a->a_tvp) 4768 vhold(a->a_tvp); 4769 } 4770 4771 #ifdef DEBUG_VFS_LOCKS 4772 void 4773 vop_strategy_pre(void *ap) 4774 { 4775 struct vop_strategy_args *a; 4776 struct buf *bp; 4777 4778 a = ap; 4779 bp = a->a_bp; 4780 4781 /* 4782 * Cluster ops lock their component buffers but not the IO container. 4783 */ 4784 if ((bp->b_flags & B_CLUSTER) != 0) 4785 return; 4786 4787 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4788 if (vfs_badlock_print) 4789 printf( 4790 "VOP_STRATEGY: bp is not locked but should be\n"); 4791 if (vfs_badlock_ddb) 4792 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4793 } 4794 } 4795 4796 void 4797 vop_lock_pre(void *ap) 4798 { 4799 struct vop_lock1_args *a = ap; 4800 4801 if ((a->a_flags & LK_INTERLOCK) == 0) 4802 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4803 else 4804 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 4805 } 4806 4807 void 4808 vop_lock_post(void *ap, int rc) 4809 { 4810 struct vop_lock1_args *a = ap; 4811 4812 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4813 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 4814 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 4815 } 4816 4817 void 4818 vop_unlock_pre(void *ap) 4819 { 4820 struct vop_unlock_args *a = ap; 4821 4822 if (a->a_flags & LK_INTERLOCK) 4823 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4824 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4825 } 4826 4827 void 4828 vop_unlock_post(void *ap, int rc) 4829 { 4830 struct vop_unlock_args *a = ap; 4831 4832 if (a->a_flags & LK_INTERLOCK) 4833 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4834 } 4835 #endif 4836 4837 void 4838 vop_create_post(void *ap, int rc) 4839 { 4840 struct vop_create_args *a = ap; 4841 4842 if (!rc) 4843 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4844 } 4845 4846 void 4847 vop_deleteextattr_post(void *ap, int rc) 4848 { 4849 struct vop_deleteextattr_args *a = ap; 4850 4851 if (!rc) 4852 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4853 } 4854 4855 void 4856 vop_link_post(void *ap, int rc) 4857 { 4858 struct vop_link_args *a = ap; 4859 4860 if (!rc) { 4861 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4862 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4863 } 4864 } 4865 4866 void 4867 vop_mkdir_post(void *ap, int rc) 4868 { 4869 struct vop_mkdir_args *a = ap; 4870 4871 if (!rc) 4872 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4873 } 4874 4875 void 4876 vop_mknod_post(void *ap, int rc) 4877 { 4878 struct vop_mknod_args *a = ap; 4879 4880 if (!rc) 4881 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4882 } 4883 4884 void 4885 vop_reclaim_post(void *ap, int rc) 4886 { 4887 struct vop_reclaim_args *a = ap; 4888 4889 if (!rc) 4890 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 4891 } 4892 4893 void 4894 vop_remove_post(void *ap, int rc) 4895 { 4896 struct vop_remove_args *a = ap; 4897 4898 if (!rc) { 4899 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4900 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4901 } 4902 } 4903 4904 void 4905 vop_rename_post(void *ap, int rc) 4906 { 4907 struct vop_rename_args *a = ap; 4908 long hint; 4909 4910 if (!rc) { 4911 hint = NOTE_WRITE; 4912 if (a->a_fdvp == a->a_tdvp) { 4913 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 4914 hint |= NOTE_LINK; 4915 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4916 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4917 } else { 4918 hint |= NOTE_EXTEND; 4919 if (a->a_fvp->v_type == VDIR) 4920 hint |= NOTE_LINK; 4921 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4922 4923 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 4924 a->a_tvp->v_type == VDIR) 4925 hint &= ~NOTE_LINK; 4926 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4927 } 4928 4929 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4930 if (a->a_tvp) 4931 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4932 } 4933 if (a->a_tdvp != a->a_fdvp) 4934 vdrop(a->a_fdvp); 4935 if (a->a_tvp != a->a_fvp) 4936 vdrop(a->a_fvp); 4937 vdrop(a->a_tdvp); 4938 if (a->a_tvp) 4939 vdrop(a->a_tvp); 4940 } 4941 4942 void 4943 vop_rmdir_post(void *ap, int rc) 4944 { 4945 struct vop_rmdir_args *a = ap; 4946 4947 if (!rc) { 4948 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4949 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4950 } 4951 } 4952 4953 void 4954 vop_setattr_post(void *ap, int rc) 4955 { 4956 struct vop_setattr_args *a = ap; 4957 4958 if (!rc) 4959 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4960 } 4961 4962 void 4963 vop_setextattr_post(void *ap, int rc) 4964 { 4965 struct vop_setextattr_args *a = ap; 4966 4967 if (!rc) 4968 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4969 } 4970 4971 void 4972 vop_symlink_post(void *ap, int rc) 4973 { 4974 struct vop_symlink_args *a = ap; 4975 4976 if (!rc) 4977 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4978 } 4979 4980 void 4981 vop_open_post(void *ap, int rc) 4982 { 4983 struct vop_open_args *a = ap; 4984 4985 if (!rc) 4986 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 4987 } 4988 4989 void 4990 vop_close_post(void *ap, int rc) 4991 { 4992 struct vop_close_args *a = ap; 4993 4994 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 4995 (a->a_vp->v_iflag & VI_DOOMED) == 0)) { 4996 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 4997 NOTE_CLOSE_WRITE : NOTE_CLOSE); 4998 } 4999 } 5000 5001 void 5002 vop_read_post(void *ap, int rc) 5003 { 5004 struct vop_read_args *a = ap; 5005 5006 if (!rc) 5007 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5008 } 5009 5010 void 5011 vop_readdir_post(void *ap, int rc) 5012 { 5013 struct vop_readdir_args *a = ap; 5014 5015 if (!rc) 5016 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5017 } 5018 5019 static struct knlist fs_knlist; 5020 5021 static void 5022 vfs_event_init(void *arg) 5023 { 5024 knlist_init_mtx(&fs_knlist, NULL); 5025 } 5026 /* XXX - correct order? */ 5027 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5028 5029 void 5030 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5031 { 5032 5033 KNOTE_UNLOCKED(&fs_knlist, event); 5034 } 5035 5036 static int filt_fsattach(struct knote *kn); 5037 static void filt_fsdetach(struct knote *kn); 5038 static int filt_fsevent(struct knote *kn, long hint); 5039 5040 struct filterops fs_filtops = { 5041 .f_isfd = 0, 5042 .f_attach = filt_fsattach, 5043 .f_detach = filt_fsdetach, 5044 .f_event = filt_fsevent 5045 }; 5046 5047 static int 5048 filt_fsattach(struct knote *kn) 5049 { 5050 5051 kn->kn_flags |= EV_CLEAR; 5052 knlist_add(&fs_knlist, kn, 0); 5053 return (0); 5054 } 5055 5056 static void 5057 filt_fsdetach(struct knote *kn) 5058 { 5059 5060 knlist_remove(&fs_knlist, kn, 0); 5061 } 5062 5063 static int 5064 filt_fsevent(struct knote *kn, long hint) 5065 { 5066 5067 kn->kn_fflags |= hint; 5068 return (kn->kn_fflags != 0); 5069 } 5070 5071 static int 5072 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5073 { 5074 struct vfsidctl vc; 5075 int error; 5076 struct mount *mp; 5077 5078 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5079 if (error) 5080 return (error); 5081 if (vc.vc_vers != VFS_CTL_VERS1) 5082 return (EINVAL); 5083 mp = vfs_getvfs(&vc.vc_fsid); 5084 if (mp == NULL) 5085 return (ENOENT); 5086 /* ensure that a specific sysctl goes to the right filesystem. */ 5087 if (strcmp(vc.vc_fstypename, "*") != 0 && 5088 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5089 vfs_rel(mp); 5090 return (EINVAL); 5091 } 5092 VCTLTOREQ(&vc, req); 5093 error = VFS_SYSCTL(mp, vc.vc_op, req); 5094 vfs_rel(mp); 5095 return (error); 5096 } 5097 5098 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 5099 NULL, 0, sysctl_vfs_ctl, "", 5100 "Sysctl by fsid"); 5101 5102 /* 5103 * Function to initialize a va_filerev field sensibly. 5104 * XXX: Wouldn't a random number make a lot more sense ?? 5105 */ 5106 u_quad_t 5107 init_va_filerev(void) 5108 { 5109 struct bintime bt; 5110 5111 getbinuptime(&bt); 5112 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5113 } 5114 5115 static int filt_vfsread(struct knote *kn, long hint); 5116 static int filt_vfswrite(struct knote *kn, long hint); 5117 static int filt_vfsvnode(struct knote *kn, long hint); 5118 static void filt_vfsdetach(struct knote *kn); 5119 static struct filterops vfsread_filtops = { 5120 .f_isfd = 1, 5121 .f_detach = filt_vfsdetach, 5122 .f_event = filt_vfsread 5123 }; 5124 static struct filterops vfswrite_filtops = { 5125 .f_isfd = 1, 5126 .f_detach = filt_vfsdetach, 5127 .f_event = filt_vfswrite 5128 }; 5129 static struct filterops vfsvnode_filtops = { 5130 .f_isfd = 1, 5131 .f_detach = filt_vfsdetach, 5132 .f_event = filt_vfsvnode 5133 }; 5134 5135 static void 5136 vfs_knllock(void *arg) 5137 { 5138 struct vnode *vp = arg; 5139 5140 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5141 } 5142 5143 static void 5144 vfs_knlunlock(void *arg) 5145 { 5146 struct vnode *vp = arg; 5147 5148 VOP_UNLOCK(vp, 0); 5149 } 5150 5151 static void 5152 vfs_knl_assert_locked(void *arg) 5153 { 5154 #ifdef DEBUG_VFS_LOCKS 5155 struct vnode *vp = arg; 5156 5157 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5158 #endif 5159 } 5160 5161 static void 5162 vfs_knl_assert_unlocked(void *arg) 5163 { 5164 #ifdef DEBUG_VFS_LOCKS 5165 struct vnode *vp = arg; 5166 5167 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5168 #endif 5169 } 5170 5171 int 5172 vfs_kqfilter(struct vop_kqfilter_args *ap) 5173 { 5174 struct vnode *vp = ap->a_vp; 5175 struct knote *kn = ap->a_kn; 5176 struct knlist *knl; 5177 5178 switch (kn->kn_filter) { 5179 case EVFILT_READ: 5180 kn->kn_fop = &vfsread_filtops; 5181 break; 5182 case EVFILT_WRITE: 5183 kn->kn_fop = &vfswrite_filtops; 5184 break; 5185 case EVFILT_VNODE: 5186 kn->kn_fop = &vfsvnode_filtops; 5187 break; 5188 default: 5189 return (EINVAL); 5190 } 5191 5192 kn->kn_hook = (caddr_t)vp; 5193 5194 v_addpollinfo(vp); 5195 if (vp->v_pollinfo == NULL) 5196 return (ENOMEM); 5197 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5198 vhold(vp); 5199 knlist_add(knl, kn, 0); 5200 5201 return (0); 5202 } 5203 5204 /* 5205 * Detach knote from vnode 5206 */ 5207 static void 5208 filt_vfsdetach(struct knote *kn) 5209 { 5210 struct vnode *vp = (struct vnode *)kn->kn_hook; 5211 5212 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5213 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5214 vdrop(vp); 5215 } 5216 5217 /*ARGSUSED*/ 5218 static int 5219 filt_vfsread(struct knote *kn, long hint) 5220 { 5221 struct vnode *vp = (struct vnode *)kn->kn_hook; 5222 struct vattr va; 5223 int res; 5224 5225 /* 5226 * filesystem is gone, so set the EOF flag and schedule 5227 * the knote for deletion. 5228 */ 5229 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5230 VI_LOCK(vp); 5231 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5232 VI_UNLOCK(vp); 5233 return (1); 5234 } 5235 5236 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5237 return (0); 5238 5239 VI_LOCK(vp); 5240 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5241 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5242 VI_UNLOCK(vp); 5243 return (res); 5244 } 5245 5246 /*ARGSUSED*/ 5247 static int 5248 filt_vfswrite(struct knote *kn, long hint) 5249 { 5250 struct vnode *vp = (struct vnode *)kn->kn_hook; 5251 5252 VI_LOCK(vp); 5253 5254 /* 5255 * filesystem is gone, so set the EOF flag and schedule 5256 * the knote for deletion. 5257 */ 5258 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5259 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5260 5261 kn->kn_data = 0; 5262 VI_UNLOCK(vp); 5263 return (1); 5264 } 5265 5266 static int 5267 filt_vfsvnode(struct knote *kn, long hint) 5268 { 5269 struct vnode *vp = (struct vnode *)kn->kn_hook; 5270 int res; 5271 5272 VI_LOCK(vp); 5273 if (kn->kn_sfflags & hint) 5274 kn->kn_fflags |= hint; 5275 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5276 kn->kn_flags |= EV_EOF; 5277 VI_UNLOCK(vp); 5278 return (1); 5279 } 5280 res = (kn->kn_fflags != 0); 5281 VI_UNLOCK(vp); 5282 return (res); 5283 } 5284 5285 int 5286 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5287 { 5288 int error; 5289 5290 if (dp->d_reclen > ap->a_uio->uio_resid) 5291 return (ENAMETOOLONG); 5292 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5293 if (error) { 5294 if (ap->a_ncookies != NULL) { 5295 if (ap->a_cookies != NULL) 5296 free(ap->a_cookies, M_TEMP); 5297 ap->a_cookies = NULL; 5298 *ap->a_ncookies = 0; 5299 } 5300 return (error); 5301 } 5302 if (ap->a_ncookies == NULL) 5303 return (0); 5304 5305 KASSERT(ap->a_cookies, 5306 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5307 5308 *ap->a_cookies = realloc(*ap->a_cookies, 5309 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5310 (*ap->a_cookies)[*ap->a_ncookies] = off; 5311 *ap->a_ncookies += 1; 5312 return (0); 5313 } 5314 5315 /* 5316 * Mark for update the access time of the file if the filesystem 5317 * supports VOP_MARKATIME. This functionality is used by execve and 5318 * mmap, so we want to avoid the I/O implied by directly setting 5319 * va_atime for the sake of efficiency. 5320 */ 5321 void 5322 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5323 { 5324 struct mount *mp; 5325 5326 mp = vp->v_mount; 5327 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5328 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5329 (void)VOP_MARKATIME(vp); 5330 } 5331 5332 /* 5333 * The purpose of this routine is to remove granularity from accmode_t, 5334 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5335 * VADMIN and VAPPEND. 5336 * 5337 * If it returns 0, the caller is supposed to continue with the usual 5338 * access checks using 'accmode' as modified by this routine. If it 5339 * returns nonzero value, the caller is supposed to return that value 5340 * as errno. 5341 * 5342 * Note that after this routine runs, accmode may be zero. 5343 */ 5344 int 5345 vfs_unixify_accmode(accmode_t *accmode) 5346 { 5347 /* 5348 * There is no way to specify explicit "deny" rule using 5349 * file mode or POSIX.1e ACLs. 5350 */ 5351 if (*accmode & VEXPLICIT_DENY) { 5352 *accmode = 0; 5353 return (0); 5354 } 5355 5356 /* 5357 * None of these can be translated into usual access bits. 5358 * Also, the common case for NFSv4 ACLs is to not contain 5359 * either of these bits. Caller should check for VWRITE 5360 * on the containing directory instead. 5361 */ 5362 if (*accmode & (VDELETE_CHILD | VDELETE)) 5363 return (EPERM); 5364 5365 if (*accmode & VADMIN_PERMS) { 5366 *accmode &= ~VADMIN_PERMS; 5367 *accmode |= VADMIN; 5368 } 5369 5370 /* 5371 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 5372 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 5373 */ 5374 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 5375 5376 return (0); 5377 } 5378 5379 /* 5380 * These are helper functions for filesystems to traverse all 5381 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 5382 * 5383 * This interface replaces MNT_VNODE_FOREACH. 5384 */ 5385 5386 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 5387 5388 struct vnode * 5389 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5390 { 5391 struct vnode *vp; 5392 5393 if (should_yield()) 5394 kern_yield(PRI_USER); 5395 MNT_ILOCK(mp); 5396 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5397 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 5398 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 5399 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5400 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5401 continue; 5402 VI_LOCK(vp); 5403 if ((vp->v_iflag & VI_DOOMED) != 0) { 5404 VI_UNLOCK(vp); 5405 continue; 5406 } 5407 break; 5408 } 5409 if (vp == NULL) { 5410 __mnt_vnode_markerfree_all(mvp, mp); 5411 /* MNT_IUNLOCK(mp); -- done in above function */ 5412 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5413 return (NULL); 5414 } 5415 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5416 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5417 MNT_IUNLOCK(mp); 5418 return (vp); 5419 } 5420 5421 struct vnode * 5422 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5423 { 5424 struct vnode *vp; 5425 5426 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5427 MNT_ILOCK(mp); 5428 MNT_REF(mp); 5429 (*mvp)->v_mount = mp; 5430 (*mvp)->v_type = VMARKER; 5431 5432 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 5433 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5434 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5435 continue; 5436 VI_LOCK(vp); 5437 if ((vp->v_iflag & VI_DOOMED) != 0) { 5438 VI_UNLOCK(vp); 5439 continue; 5440 } 5441 break; 5442 } 5443 if (vp == NULL) { 5444 MNT_REL(mp); 5445 MNT_IUNLOCK(mp); 5446 free(*mvp, M_VNODE_MARKER); 5447 *mvp = NULL; 5448 return (NULL); 5449 } 5450 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5451 MNT_IUNLOCK(mp); 5452 return (vp); 5453 } 5454 5455 void 5456 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5457 { 5458 5459 if (*mvp == NULL) { 5460 MNT_IUNLOCK(mp); 5461 return; 5462 } 5463 5464 mtx_assert(MNT_MTX(mp), MA_OWNED); 5465 5466 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5467 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5468 MNT_REL(mp); 5469 MNT_IUNLOCK(mp); 5470 free(*mvp, M_VNODE_MARKER); 5471 *mvp = NULL; 5472 } 5473 5474 /* 5475 * These are helper functions for filesystems to traverse their 5476 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5477 */ 5478 static void 5479 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5480 { 5481 5482 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5483 5484 MNT_ILOCK(mp); 5485 MNT_REL(mp); 5486 MNT_IUNLOCK(mp); 5487 free(*mvp, M_VNODE_MARKER); 5488 *mvp = NULL; 5489 } 5490 5491 /* 5492 * Relock the mp mount vnode list lock with the vp vnode interlock in the 5493 * conventional lock order during mnt_vnode_next_active iteration. 5494 * 5495 * On entry, the mount vnode list lock is held and the vnode interlock is not. 5496 * The list lock is dropped and reacquired. On success, both locks are held. 5497 * On failure, the mount vnode list lock is held but the vnode interlock is 5498 * not, and the procedure may have yielded. 5499 */ 5500 static bool 5501 mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp, 5502 struct vnode *vp) 5503 { 5504 const struct vnode *tmp; 5505 bool held, ret; 5506 5507 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 5508 TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp, 5509 ("%s: bad marker", __func__)); 5510 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 5511 ("%s: inappropriate vnode", __func__)); 5512 ASSERT_VI_UNLOCKED(vp, __func__); 5513 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5514 5515 ret = false; 5516 5517 TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist); 5518 TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist); 5519 5520 /* 5521 * Use a hold to prevent vp from disappearing while the mount vnode 5522 * list lock is dropped and reacquired. Normally a hold would be 5523 * acquired with vhold(), but that might try to acquire the vnode 5524 * interlock, which would be a LOR with the mount vnode list lock. 5525 */ 5526 held = refcount_acquire_if_not_zero(&vp->v_holdcnt); 5527 mtx_unlock(&mp->mnt_listmtx); 5528 if (!held) 5529 goto abort; 5530 VI_LOCK(vp); 5531 if (!refcount_release_if_not_last(&vp->v_holdcnt)) { 5532 vdropl(vp); 5533 goto abort; 5534 } 5535 mtx_lock(&mp->mnt_listmtx); 5536 5537 /* 5538 * Determine whether the vnode is still the next one after the marker, 5539 * excepting any other markers. If the vnode has not been doomed by 5540 * vgone() then the hold should have ensured that it remained on the 5541 * active list. If it has been doomed but is still on the active list, 5542 * don't abort, but rather skip over it (avoid spinning on doomed 5543 * vnodes). 5544 */ 5545 tmp = mvp; 5546 do { 5547 tmp = TAILQ_NEXT(tmp, v_actfreelist); 5548 } while (tmp != NULL && tmp->v_type == VMARKER); 5549 if (tmp != vp) { 5550 mtx_unlock(&mp->mnt_listmtx); 5551 VI_UNLOCK(vp); 5552 goto abort; 5553 } 5554 5555 ret = true; 5556 goto out; 5557 abort: 5558 maybe_yield(); 5559 mtx_lock(&mp->mnt_listmtx); 5560 out: 5561 if (ret) 5562 ASSERT_VI_LOCKED(vp, __func__); 5563 else 5564 ASSERT_VI_UNLOCKED(vp, __func__); 5565 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5566 return (ret); 5567 } 5568 5569 static struct vnode * 5570 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5571 { 5572 struct vnode *vp, *nvp; 5573 5574 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5575 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5576 restart: 5577 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5578 while (vp != NULL) { 5579 if (vp->v_type == VMARKER) { 5580 vp = TAILQ_NEXT(vp, v_actfreelist); 5581 continue; 5582 } 5583 /* 5584 * Try-lock because this is the wrong lock order. If that does 5585 * not succeed, drop the mount vnode list lock and try to 5586 * reacquire it and the vnode interlock in the right order. 5587 */ 5588 if (!VI_TRYLOCK(vp) && 5589 !mnt_vnode_next_active_relock(*mvp, mp, vp)) 5590 goto restart; 5591 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5592 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5593 ("alien vnode on the active list %p %p", vp, mp)); 5594 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) 5595 break; 5596 nvp = TAILQ_NEXT(vp, v_actfreelist); 5597 VI_UNLOCK(vp); 5598 vp = nvp; 5599 } 5600 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5601 5602 /* Check if we are done */ 5603 if (vp == NULL) { 5604 mtx_unlock(&mp->mnt_listmtx); 5605 mnt_vnode_markerfree_active(mvp, mp); 5606 return (NULL); 5607 } 5608 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 5609 mtx_unlock(&mp->mnt_listmtx); 5610 ASSERT_VI_LOCKED(vp, "active iter"); 5611 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 5612 return (vp); 5613 } 5614 5615 struct vnode * 5616 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5617 { 5618 5619 if (should_yield()) 5620 kern_yield(PRI_USER); 5621 mtx_lock(&mp->mnt_listmtx); 5622 return (mnt_vnode_next_active(mvp, mp)); 5623 } 5624 5625 struct vnode * 5626 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 5627 { 5628 struct vnode *vp; 5629 5630 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5631 MNT_ILOCK(mp); 5632 MNT_REF(mp); 5633 MNT_IUNLOCK(mp); 5634 (*mvp)->v_type = VMARKER; 5635 (*mvp)->v_mount = mp; 5636 5637 mtx_lock(&mp->mnt_listmtx); 5638 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 5639 if (vp == NULL) { 5640 mtx_unlock(&mp->mnt_listmtx); 5641 mnt_vnode_markerfree_active(mvp, mp); 5642 return (NULL); 5643 } 5644 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5645 return (mnt_vnode_next_active(mvp, mp)); 5646 } 5647 5648 void 5649 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5650 { 5651 5652 if (*mvp == NULL) 5653 return; 5654 5655 mtx_lock(&mp->mnt_listmtx); 5656 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5657 mtx_unlock(&mp->mnt_listmtx); 5658 mnt_vnode_markerfree_active(mvp, mp); 5659 } 5660