1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 37 */ 38 39 /* 40 * External virtual filesystem routines 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_ddb.h" 47 #include "opt_watchdog.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/bio.h> 52 #include <sys/buf.h> 53 #include <sys/capsicum.h> 54 #include <sys/condvar.h> 55 #include <sys/conf.h> 56 #include <sys/counter.h> 57 #include <sys/dirent.h> 58 #include <sys/event.h> 59 #include <sys/eventhandler.h> 60 #include <sys/extattr.h> 61 #include <sys/file.h> 62 #include <sys/fcntl.h> 63 #include <sys/jail.h> 64 #include <sys/kdb.h> 65 #include <sys/kernel.h> 66 #include <sys/kthread.h> 67 #include <sys/ktr.h> 68 #include <sys/lockf.h> 69 #include <sys/malloc.h> 70 #include <sys/mount.h> 71 #include <sys/namei.h> 72 #include <sys/pctrie.h> 73 #include <sys/priv.h> 74 #include <sys/reboot.h> 75 #include <sys/refcount.h> 76 #include <sys/rwlock.h> 77 #include <sys/sched.h> 78 #include <sys/sleepqueue.h> 79 #include <sys/smp.h> 80 #include <sys/stat.h> 81 #include <sys/sysctl.h> 82 #include <sys/syslog.h> 83 #include <sys/vmmeter.h> 84 #include <sys/vnode.h> 85 #include <sys/watchdog.h> 86 87 #include <machine/stdarg.h> 88 89 #include <security/mac/mac_framework.h> 90 91 #include <vm/vm.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_extern.h> 94 #include <vm/pmap.h> 95 #include <vm/vm_map.h> 96 #include <vm/vm_page.h> 97 #include <vm/vm_kern.h> 98 #include <vm/uma.h> 99 100 #ifdef DDB 101 #include <ddb/ddb.h> 102 #endif 103 104 static void delmntque(struct vnode *vp); 105 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 106 int slpflag, int slptimeo); 107 static void syncer_shutdown(void *arg, int howto); 108 static int vtryrecycle(struct vnode *vp); 109 static void v_init_counters(struct vnode *); 110 static void v_incr_devcount(struct vnode *); 111 static void v_decr_devcount(struct vnode *); 112 static void vgonel(struct vnode *); 113 static void vfs_knllock(void *arg); 114 static void vfs_knlunlock(void *arg); 115 static void vfs_knl_assert_locked(void *arg); 116 static void vfs_knl_assert_unlocked(void *arg); 117 static void vnlru_return_batches(struct vfsops *mnt_op); 118 static void destroy_vpollinfo(struct vpollinfo *vi); 119 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 120 daddr_t startlbn, daddr_t endlbn); 121 122 /* 123 * These fences are intended for cases where some synchronization is 124 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 125 * and v_usecount) updates. Access to v_iflags is generally synchronized 126 * by the interlock, but we have some internal assertions that check vnode 127 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 128 * for now. 129 */ 130 #ifdef INVARIANTS 131 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 132 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 133 #else 134 #define VNODE_REFCOUNT_FENCE_ACQ() 135 #define VNODE_REFCOUNT_FENCE_REL() 136 #endif 137 138 /* 139 * Number of vnodes in existence. Increased whenever getnewvnode() 140 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode. 141 */ 142 static 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 | CTLFLAG_STATS, 214 &reassignbufcalls, 0, "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, 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 (VN_IS_DOOMED(vp)) { 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); 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 if (vfs_op_thread_enter(mp)) { 645 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 646 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0); 647 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0); 648 vfs_mp_count_add_pcpu(mp, ref, 1); 649 vfs_mp_count_add_pcpu(mp, lockref, 1); 650 vfs_op_thread_exit(mp); 651 if (flags & MBF_MNTLSTLOCK) 652 mtx_unlock(&mountlist_mtx); 653 return (0); 654 } 655 656 MNT_ILOCK(mp); 657 vfs_assert_mount_counters(mp); 658 MNT_REF(mp); 659 /* 660 * If mount point is currently being unmounted, sleep until the 661 * mount point fate is decided. If thread doing the unmounting fails, 662 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 663 * that this mount point has survived the unmount attempt and vfs_busy 664 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 665 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 666 * about to be really destroyed. vfs_busy needs to release its 667 * reference on the mount point in this case and return with ENOENT, 668 * telling the caller that mount mount it tried to busy is no longer 669 * valid. 670 */ 671 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 672 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 673 MNT_REL(mp); 674 MNT_IUNLOCK(mp); 675 CTR1(KTR_VFS, "%s: failed busying before sleeping", 676 __func__); 677 return (ENOENT); 678 } 679 if (flags & MBF_MNTLSTLOCK) 680 mtx_unlock(&mountlist_mtx); 681 mp->mnt_kern_flag |= MNTK_MWAIT; 682 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 683 if (flags & MBF_MNTLSTLOCK) 684 mtx_lock(&mountlist_mtx); 685 MNT_ILOCK(mp); 686 } 687 if (flags & MBF_MNTLSTLOCK) 688 mtx_unlock(&mountlist_mtx); 689 mp->mnt_lockref++; 690 MNT_IUNLOCK(mp); 691 return (0); 692 } 693 694 /* 695 * Free a busy filesystem. 696 */ 697 void 698 vfs_unbusy(struct mount *mp) 699 { 700 int c; 701 702 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 703 704 if (vfs_op_thread_enter(mp)) { 705 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 706 vfs_mp_count_sub_pcpu(mp, lockref, 1); 707 vfs_mp_count_sub_pcpu(mp, ref, 1); 708 vfs_op_thread_exit(mp); 709 return; 710 } 711 712 MNT_ILOCK(mp); 713 vfs_assert_mount_counters(mp); 714 MNT_REL(mp); 715 c = --mp->mnt_lockref; 716 if (mp->mnt_vfs_ops == 0) { 717 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0); 718 MNT_IUNLOCK(mp); 719 return; 720 } 721 if (c < 0) 722 vfs_dump_mount_counters(mp); 723 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 724 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 725 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 726 mp->mnt_kern_flag &= ~MNTK_DRAINING; 727 wakeup(&mp->mnt_lockref); 728 } 729 MNT_IUNLOCK(mp); 730 } 731 732 /* 733 * Lookup a mount point by filesystem identifier. 734 */ 735 struct mount * 736 vfs_getvfs(fsid_t *fsid) 737 { 738 struct mount *mp; 739 740 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 741 mtx_lock(&mountlist_mtx); 742 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 743 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 744 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 745 vfs_ref(mp); 746 mtx_unlock(&mountlist_mtx); 747 return (mp); 748 } 749 } 750 mtx_unlock(&mountlist_mtx); 751 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 752 return ((struct mount *) 0); 753 } 754 755 /* 756 * Lookup a mount point by filesystem identifier, busying it before 757 * returning. 758 * 759 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 760 * cache for popular filesystem identifiers. The cache is lockess, using 761 * the fact that struct mount's are never freed. In worst case we may 762 * get pointer to unmounted or even different filesystem, so we have to 763 * check what we got, and go slow way if so. 764 */ 765 struct mount * 766 vfs_busyfs(fsid_t *fsid) 767 { 768 #define FSID_CACHE_SIZE 256 769 typedef struct mount * volatile vmp_t; 770 static vmp_t cache[FSID_CACHE_SIZE]; 771 struct mount *mp; 772 int error; 773 uint32_t hash; 774 775 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 776 hash = fsid->val[0] ^ fsid->val[1]; 777 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 778 mp = cache[hash]; 779 if (mp == NULL || 780 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 781 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 782 goto slow; 783 if (vfs_busy(mp, 0) != 0) { 784 cache[hash] = NULL; 785 goto slow; 786 } 787 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 788 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 789 return (mp); 790 else 791 vfs_unbusy(mp); 792 793 slow: 794 mtx_lock(&mountlist_mtx); 795 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 796 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 797 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 798 error = vfs_busy(mp, MBF_MNTLSTLOCK); 799 if (error) { 800 cache[hash] = NULL; 801 mtx_unlock(&mountlist_mtx); 802 return (NULL); 803 } 804 cache[hash] = mp; 805 return (mp); 806 } 807 } 808 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 809 mtx_unlock(&mountlist_mtx); 810 return ((struct mount *) 0); 811 } 812 813 /* 814 * Check if a user can access privileged mount options. 815 */ 816 int 817 vfs_suser(struct mount *mp, struct thread *td) 818 { 819 int error; 820 821 if (jailed(td->td_ucred)) { 822 /* 823 * If the jail of the calling thread lacks permission for 824 * this type of file system, deny immediately. 825 */ 826 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 827 return (EPERM); 828 829 /* 830 * If the file system was mounted outside the jail of the 831 * calling thread, deny immediately. 832 */ 833 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 834 return (EPERM); 835 } 836 837 /* 838 * If file system supports delegated administration, we don't check 839 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 840 * by the file system itself. 841 * If this is not the user that did original mount, we check for 842 * the PRIV_VFS_MOUNT_OWNER privilege. 843 */ 844 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 845 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 846 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 847 return (error); 848 } 849 return (0); 850 } 851 852 /* 853 * Get a new unique fsid. Try to make its val[0] unique, since this value 854 * will be used to create fake device numbers for stat(). Also try (but 855 * not so hard) make its val[0] unique mod 2^16, since some emulators only 856 * support 16-bit device numbers. We end up with unique val[0]'s for the 857 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 858 * 859 * Keep in mind that several mounts may be running in parallel. Starting 860 * the search one past where the previous search terminated is both a 861 * micro-optimization and a defense against returning the same fsid to 862 * different mounts. 863 */ 864 void 865 vfs_getnewfsid(struct mount *mp) 866 { 867 static uint16_t mntid_base; 868 struct mount *nmp; 869 fsid_t tfsid; 870 int mtype; 871 872 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 873 mtx_lock(&mntid_mtx); 874 mtype = mp->mnt_vfc->vfc_typenum; 875 tfsid.val[1] = mtype; 876 mtype = (mtype & 0xFF) << 24; 877 for (;;) { 878 tfsid.val[0] = makedev(255, 879 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 880 mntid_base++; 881 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 882 break; 883 vfs_rel(nmp); 884 } 885 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 886 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 887 mtx_unlock(&mntid_mtx); 888 } 889 890 /* 891 * Knob to control the precision of file timestamps: 892 * 893 * 0 = seconds only; nanoseconds zeroed. 894 * 1 = seconds and nanoseconds, accurate within 1/HZ. 895 * 2 = seconds and nanoseconds, truncated to microseconds. 896 * >=3 = seconds and nanoseconds, maximum precision. 897 */ 898 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 899 900 static int timestamp_precision = TSP_USEC; 901 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 902 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 903 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 904 "3+: sec + ns (max. precision))"); 905 906 /* 907 * Get a current timestamp. 908 */ 909 void 910 vfs_timestamp(struct timespec *tsp) 911 { 912 struct timeval tv; 913 914 switch (timestamp_precision) { 915 case TSP_SEC: 916 tsp->tv_sec = time_second; 917 tsp->tv_nsec = 0; 918 break; 919 case TSP_HZ: 920 getnanotime(tsp); 921 break; 922 case TSP_USEC: 923 microtime(&tv); 924 TIMEVAL_TO_TIMESPEC(&tv, tsp); 925 break; 926 case TSP_NSEC: 927 default: 928 nanotime(tsp); 929 break; 930 } 931 } 932 933 /* 934 * Set vnode attributes to VNOVAL 935 */ 936 void 937 vattr_null(struct vattr *vap) 938 { 939 940 vap->va_type = VNON; 941 vap->va_size = VNOVAL; 942 vap->va_bytes = VNOVAL; 943 vap->va_mode = VNOVAL; 944 vap->va_nlink = VNOVAL; 945 vap->va_uid = VNOVAL; 946 vap->va_gid = VNOVAL; 947 vap->va_fsid = VNOVAL; 948 vap->va_fileid = VNOVAL; 949 vap->va_blocksize = VNOVAL; 950 vap->va_rdev = VNOVAL; 951 vap->va_atime.tv_sec = VNOVAL; 952 vap->va_atime.tv_nsec = VNOVAL; 953 vap->va_mtime.tv_sec = VNOVAL; 954 vap->va_mtime.tv_nsec = VNOVAL; 955 vap->va_ctime.tv_sec = VNOVAL; 956 vap->va_ctime.tv_nsec = VNOVAL; 957 vap->va_birthtime.tv_sec = VNOVAL; 958 vap->va_birthtime.tv_nsec = VNOVAL; 959 vap->va_flags = VNOVAL; 960 vap->va_gen = VNOVAL; 961 vap->va_vaflags = 0; 962 } 963 964 /* 965 * This routine is called when we have too many vnodes. It attempts 966 * to free <count> vnodes and will potentially free vnodes that still 967 * have VM backing store (VM backing store is typically the cause 968 * of a vnode blowout so we want to do this). Therefore, this operation 969 * is not considered cheap. 970 * 971 * A number of conditions may prevent a vnode from being reclaimed. 972 * the buffer cache may have references on the vnode, a directory 973 * vnode may still have references due to the namei cache representing 974 * underlying files, or the vnode may be in active use. It is not 975 * desirable to reuse such vnodes. These conditions may cause the 976 * number of vnodes to reach some minimum value regardless of what 977 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 978 * 979 * @param mp Try to reclaim vnodes from this mountpoint 980 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 981 * entries if this argument is strue 982 * @param trigger Only reclaim vnodes with fewer than this many resident 983 * pages. 984 * @return The number of vnodes that were reclaimed. 985 */ 986 static int 987 vlrureclaim(struct mount *mp, bool reclaim_nc_src, int trigger) 988 { 989 struct vnode *vp; 990 int count, done, target; 991 992 done = 0; 993 vn_start_write(NULL, &mp, V_WAIT); 994 MNT_ILOCK(mp); 995 count = mp->mnt_nvnodelistsize; 996 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1); 997 target = target / 10 + 1; 998 while (count != 0 && done < target) { 999 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1000 while (vp != NULL && vp->v_type == VMARKER) 1001 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1002 if (vp == NULL) 1003 break; 1004 /* 1005 * XXX LRU is completely broken for non-free vnodes. First 1006 * by calling here in mountpoint order, then by moving 1007 * unselected vnodes to the end here, and most grossly by 1008 * removing the vlruvp() function that was supposed to 1009 * maintain the order. (This function was born broken 1010 * since syncer problems prevented it doing anything.) The 1011 * order is closer to LRC (C = Created). 1012 * 1013 * LRU reclaiming of vnodes seems to have last worked in 1014 * FreeBSD-3 where LRU wasn't mentioned under any spelling. 1015 * Then there was no hold count, and inactive vnodes were 1016 * simply put on the free list in LRU order. The separate 1017 * lists also break LRU. We prefer to reclaim from the 1018 * free list for technical reasons. This tends to thrash 1019 * the free list to keep very unrecently used held vnodes. 1020 * The problem is mitigated by keeping the free list large. 1021 */ 1022 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1023 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1024 --count; 1025 if (!VI_TRYLOCK(vp)) 1026 goto next_iter; 1027 /* 1028 * If it's been deconstructed already, it's still 1029 * referenced, or it exceeds the trigger, skip it. 1030 * Also skip free vnodes. We are trying to make space 1031 * to expand the free list, not reduce it. 1032 */ 1033 if (vp->v_usecount || 1034 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1035 ((vp->v_iflag & VI_FREE) != 0) || 1036 VN_IS_DOOMED(vp) || (vp->v_object != NULL && 1037 vp->v_object->resident_page_count > trigger)) { 1038 VI_UNLOCK(vp); 1039 goto next_iter; 1040 } 1041 MNT_IUNLOCK(mp); 1042 vholdl(vp); 1043 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 1044 vdrop(vp); 1045 goto next_iter_mntunlocked; 1046 } 1047 VI_LOCK(vp); 1048 /* 1049 * v_usecount may have been bumped after VOP_LOCK() dropped 1050 * the vnode interlock and before it was locked again. 1051 * 1052 * It is not necessary to recheck VIRF_DOOMED because it can 1053 * only be set by another thread that holds both the vnode 1054 * lock and vnode interlock. If another thread has the 1055 * vnode lock before we get to VOP_LOCK() and obtains the 1056 * vnode interlock after VOP_LOCK() drops the vnode 1057 * interlock, the other thread will be unable to drop the 1058 * vnode lock before our VOP_LOCK() call fails. 1059 */ 1060 if (vp->v_usecount || 1061 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1062 (vp->v_object != NULL && 1063 vp->v_object->resident_page_count > trigger)) { 1064 VOP_UNLOCK(vp); 1065 vdropl(vp); 1066 goto next_iter_mntunlocked; 1067 } 1068 KASSERT(!VN_IS_DOOMED(vp), 1069 ("VIRF_DOOMED unexpectedly detected in vlrureclaim()")); 1070 counter_u64_add(recycles_count, 1); 1071 vgonel(vp); 1072 VOP_UNLOCK(vp); 1073 vdropl(vp); 1074 done++; 1075 next_iter_mntunlocked: 1076 if (!should_yield()) 1077 goto relock_mnt; 1078 goto yield; 1079 next_iter: 1080 if (!should_yield()) 1081 continue; 1082 MNT_IUNLOCK(mp); 1083 yield: 1084 kern_yield(PRI_USER); 1085 relock_mnt: 1086 MNT_ILOCK(mp); 1087 } 1088 MNT_IUNLOCK(mp); 1089 vn_finished_write(mp); 1090 return done; 1091 } 1092 1093 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1094 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1095 0, 1096 "limit on vnode free requests per call to the vnlru_free routine"); 1097 1098 /* 1099 * Attempt to reduce the free list by the requested amount. 1100 */ 1101 static void 1102 vnlru_free_locked(int count, struct vfsops *mnt_op) 1103 { 1104 struct vnode *vp; 1105 struct mount *mp; 1106 bool tried_batches; 1107 1108 tried_batches = false; 1109 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1110 if (count > max_vnlru_free) 1111 count = max_vnlru_free; 1112 for (; count > 0; count--) { 1113 vp = TAILQ_FIRST(&vnode_free_list); 1114 /* 1115 * The list can be modified while the free_list_mtx 1116 * has been dropped and vp could be NULL here. 1117 */ 1118 if (vp == NULL) { 1119 if (tried_batches) 1120 break; 1121 mtx_unlock(&vnode_free_list_mtx); 1122 vnlru_return_batches(mnt_op); 1123 tried_batches = true; 1124 mtx_lock(&vnode_free_list_mtx); 1125 continue; 1126 } 1127 1128 VNASSERT(vp->v_op != NULL, vp, 1129 ("vnlru_free: vnode already reclaimed.")); 1130 KASSERT((vp->v_iflag & VI_FREE) != 0, 1131 ("Removing vnode not on freelist")); 1132 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1133 ("Mangling active vnode")); 1134 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 1135 1136 /* 1137 * Don't recycle if our vnode is from different type 1138 * of mount point. Note that mp is type-safe, the 1139 * check does not reach unmapped address even if 1140 * vnode is reclaimed. 1141 * Don't recycle if we can't get the interlock without 1142 * blocking. 1143 */ 1144 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL && 1145 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1146 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist); 1147 continue; 1148 } 1149 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0, 1150 vp, ("vp inconsistent on freelist")); 1151 1152 /* 1153 * The clear of VI_FREE prevents activation of the 1154 * vnode. There is no sense in putting the vnode on 1155 * the mount point active list, only to remove it 1156 * later during recycling. Inline the relevant part 1157 * of vholdl(), to avoid triggering assertions or 1158 * activating. 1159 */ 1160 freevnodes--; 1161 vp->v_iflag &= ~VI_FREE; 1162 VNODE_REFCOUNT_FENCE_REL(); 1163 refcount_acquire(&vp->v_holdcnt); 1164 1165 mtx_unlock(&vnode_free_list_mtx); 1166 VI_UNLOCK(vp); 1167 vtryrecycle(vp); 1168 /* 1169 * If the recycled succeeded this vdrop will actually free 1170 * the vnode. If not it will simply place it back on 1171 * the free list. 1172 */ 1173 vdrop(vp); 1174 mtx_lock(&vnode_free_list_mtx); 1175 } 1176 } 1177 1178 void 1179 vnlru_free(int count, struct vfsops *mnt_op) 1180 { 1181 1182 mtx_lock(&vnode_free_list_mtx); 1183 vnlru_free_locked(count, mnt_op); 1184 mtx_unlock(&vnode_free_list_mtx); 1185 } 1186 1187 1188 /* XXX some names and initialization are bad for limits and watermarks. */ 1189 static int 1190 vspace(void) 1191 { 1192 int space; 1193 1194 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1195 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1196 vlowat = vhiwat / 2; 1197 if (numvnodes > desiredvnodes) 1198 return (0); 1199 space = desiredvnodes - numvnodes; 1200 if (freevnodes > wantfreevnodes) 1201 space += freevnodes - wantfreevnodes; 1202 return (space); 1203 } 1204 1205 static void 1206 vnlru_return_batch_locked(struct mount *mp) 1207 { 1208 struct vnode *vp; 1209 1210 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 1211 1212 if (mp->mnt_tmpfreevnodelistsize == 0) 1213 return; 1214 1215 TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) { 1216 VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp, 1217 ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist")); 1218 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 1219 } 1220 mtx_lock(&vnode_free_list_mtx); 1221 TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist); 1222 freevnodes += mp->mnt_tmpfreevnodelistsize; 1223 mtx_unlock(&vnode_free_list_mtx); 1224 mp->mnt_tmpfreevnodelistsize = 0; 1225 } 1226 1227 static void 1228 vnlru_return_batch(struct mount *mp) 1229 { 1230 1231 mtx_lock(&mp->mnt_listmtx); 1232 vnlru_return_batch_locked(mp); 1233 mtx_unlock(&mp->mnt_listmtx); 1234 } 1235 1236 static void 1237 vnlru_return_batches(struct vfsops *mnt_op) 1238 { 1239 struct mount *mp, *nmp; 1240 bool need_unbusy; 1241 1242 mtx_lock(&mountlist_mtx); 1243 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1244 need_unbusy = false; 1245 if (mnt_op != NULL && mp->mnt_op != mnt_op) 1246 goto next; 1247 if (mp->mnt_tmpfreevnodelistsize == 0) 1248 goto next; 1249 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) { 1250 vnlru_return_batch(mp); 1251 need_unbusy = true; 1252 mtx_lock(&mountlist_mtx); 1253 } 1254 next: 1255 nmp = TAILQ_NEXT(mp, mnt_list); 1256 if (need_unbusy) 1257 vfs_unbusy(mp); 1258 } 1259 mtx_unlock(&mountlist_mtx); 1260 } 1261 1262 /* 1263 * Attempt to recycle vnodes in a context that is always safe to block. 1264 * Calling vlrurecycle() from the bowels of filesystem code has some 1265 * interesting deadlock problems. 1266 */ 1267 static struct proc *vnlruproc; 1268 static int vnlruproc_sig; 1269 1270 static void 1271 vnlru_proc(void) 1272 { 1273 struct mount *mp, *nmp; 1274 unsigned long onumvnodes; 1275 int done, force, trigger, usevnodes, vsp; 1276 bool reclaim_nc_src; 1277 1278 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1279 SHUTDOWN_PRI_FIRST); 1280 1281 force = 0; 1282 for (;;) { 1283 kproc_suspend_check(vnlruproc); 1284 mtx_lock(&vnode_free_list_mtx); 1285 /* 1286 * If numvnodes is too large (due to desiredvnodes being 1287 * adjusted using its sysctl, or emergency growth), first 1288 * try to reduce it by discarding from the free list. 1289 */ 1290 if (numvnodes > desiredvnodes) 1291 vnlru_free_locked(numvnodes - desiredvnodes, NULL); 1292 /* 1293 * Sleep if the vnode cache is in a good state. This is 1294 * when it is not over-full and has space for about a 4% 1295 * or 9% expansion (by growing its size or inexcessively 1296 * reducing its free list). Otherwise, try to reclaim 1297 * space for a 10% expansion. 1298 */ 1299 if (vstir && force == 0) { 1300 force = 1; 1301 vstir = 0; 1302 } 1303 vsp = vspace(); 1304 if (vsp >= vlowat && force == 0) { 1305 vnlruproc_sig = 0; 1306 wakeup(&vnlruproc_sig); 1307 msleep(vnlruproc, &vnode_free_list_mtx, 1308 PVFS|PDROP, "vlruwt", hz); 1309 continue; 1310 } 1311 mtx_unlock(&vnode_free_list_mtx); 1312 done = 0; 1313 onumvnodes = numvnodes; 1314 /* 1315 * Calculate parameters for recycling. These are the same 1316 * throughout the loop to give some semblance of fairness. 1317 * The trigger point is to avoid recycling vnodes with lots 1318 * of resident pages. We aren't trying to free memory; we 1319 * are trying to recycle or at least free vnodes. 1320 */ 1321 if (numvnodes <= desiredvnodes) 1322 usevnodes = numvnodes - freevnodes; 1323 else 1324 usevnodes = numvnodes; 1325 if (usevnodes <= 0) 1326 usevnodes = 1; 1327 /* 1328 * The trigger value is is chosen to give a conservatively 1329 * large value to ensure that it alone doesn't prevent 1330 * making progress. The value can easily be so large that 1331 * it is effectively infinite in some congested and 1332 * misconfigured cases, and this is necessary. Normally 1333 * it is about 8 to 100 (pages), which is quite large. 1334 */ 1335 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1336 if (force < 2) 1337 trigger = vsmalltrigger; 1338 reclaim_nc_src = force >= 3; 1339 mtx_lock(&mountlist_mtx); 1340 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1341 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { 1342 nmp = TAILQ_NEXT(mp, mnt_list); 1343 continue; 1344 } 1345 done += vlrureclaim(mp, reclaim_nc_src, trigger); 1346 mtx_lock(&mountlist_mtx); 1347 nmp = TAILQ_NEXT(mp, mnt_list); 1348 vfs_unbusy(mp); 1349 } 1350 mtx_unlock(&mountlist_mtx); 1351 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1352 uma_reclaim(UMA_RECLAIM_DRAIN); 1353 if (done == 0) { 1354 if (force == 0 || force == 1) { 1355 force = 2; 1356 continue; 1357 } 1358 if (force == 2) { 1359 force = 3; 1360 continue; 1361 } 1362 force = 0; 1363 vnlru_nowhere++; 1364 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1365 } else 1366 kern_yield(PRI_USER); 1367 /* 1368 * After becoming active to expand above low water, keep 1369 * active until above high water. 1370 */ 1371 vsp = vspace(); 1372 force = vsp < vhiwat; 1373 } 1374 } 1375 1376 static struct kproc_desc vnlru_kp = { 1377 "vnlru", 1378 vnlru_proc, 1379 &vnlruproc 1380 }; 1381 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1382 &vnlru_kp); 1383 1384 /* 1385 * Routines having to do with the management of the vnode table. 1386 */ 1387 1388 /* 1389 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1390 * before we actually vgone(). This function must be called with the vnode 1391 * held to prevent the vnode from being returned to the free list midway 1392 * through vgone(). 1393 */ 1394 static int 1395 vtryrecycle(struct vnode *vp) 1396 { 1397 struct mount *vnmp; 1398 1399 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1400 VNASSERT(vp->v_holdcnt, vp, 1401 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1402 /* 1403 * This vnode may found and locked via some other list, if so we 1404 * can't recycle it yet. 1405 */ 1406 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1407 CTR2(KTR_VFS, 1408 "%s: impossible to recycle, vp %p lock is already held", 1409 __func__, vp); 1410 return (EWOULDBLOCK); 1411 } 1412 /* 1413 * Don't recycle if its filesystem is being suspended. 1414 */ 1415 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1416 VOP_UNLOCK(vp); 1417 CTR2(KTR_VFS, 1418 "%s: impossible to recycle, cannot start the write for %p", 1419 __func__, vp); 1420 return (EBUSY); 1421 } 1422 /* 1423 * If we got this far, we need to acquire the interlock and see if 1424 * anyone picked up this vnode from another list. If not, we will 1425 * mark it with DOOMED via vgonel() so that anyone who does find it 1426 * will skip over it. 1427 */ 1428 VI_LOCK(vp); 1429 if (vp->v_usecount) { 1430 VOP_UNLOCK(vp); 1431 VI_UNLOCK(vp); 1432 vn_finished_write(vnmp); 1433 CTR2(KTR_VFS, 1434 "%s: impossible to recycle, %p is already referenced", 1435 __func__, vp); 1436 return (EBUSY); 1437 } 1438 if (!VN_IS_DOOMED(vp)) { 1439 counter_u64_add(recycles_count, 1); 1440 vgonel(vp); 1441 } 1442 VOP_UNLOCK(vp); 1443 VI_UNLOCK(vp); 1444 vn_finished_write(vnmp); 1445 return (0); 1446 } 1447 1448 static void 1449 vcheckspace(void) 1450 { 1451 int vsp; 1452 1453 vsp = vspace(); 1454 if (vsp < vlowat && vnlruproc_sig == 0) { 1455 vnlruproc_sig = 1; 1456 wakeup(vnlruproc); 1457 } 1458 } 1459 1460 /* 1461 * Wait if necessary for space for a new vnode. 1462 */ 1463 static int 1464 getnewvnode_wait(int suspended) 1465 { 1466 1467 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1468 if (numvnodes >= desiredvnodes) { 1469 if (suspended) { 1470 /* 1471 * The file system is being suspended. We cannot 1472 * risk a deadlock here, so allow allocation of 1473 * another vnode even if this would give too many. 1474 */ 1475 return (0); 1476 } 1477 if (vnlruproc_sig == 0) { 1478 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 1479 wakeup(vnlruproc); 1480 } 1481 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 1482 "vlruwk", hz); 1483 } 1484 /* Post-adjust like the pre-adjust in getnewvnode(). */ 1485 if (numvnodes + 1 > desiredvnodes && freevnodes > 1) 1486 vnlru_free_locked(1, NULL); 1487 return (numvnodes >= desiredvnodes ? ENFILE : 0); 1488 } 1489 1490 /* 1491 * This hack is fragile, and probably not needed any more now that the 1492 * watermark handling works. 1493 */ 1494 void 1495 getnewvnode_reserve(u_int count) 1496 { 1497 struct thread *td; 1498 1499 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */ 1500 /* XXX no longer so quick, but this part is not racy. */ 1501 mtx_lock(&vnode_free_list_mtx); 1502 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes) 1503 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes, 1504 freevnodes - wantfreevnodes), NULL); 1505 mtx_unlock(&vnode_free_list_mtx); 1506 1507 td = curthread; 1508 /* First try to be quick and racy. */ 1509 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) { 1510 td->td_vp_reserv += count; 1511 vcheckspace(); /* XXX no longer so quick, but more racy */ 1512 return; 1513 } else 1514 atomic_subtract_long(&numvnodes, count); 1515 1516 mtx_lock(&vnode_free_list_mtx); 1517 while (count > 0) { 1518 if (getnewvnode_wait(0) == 0) { 1519 count--; 1520 td->td_vp_reserv++; 1521 atomic_add_long(&numvnodes, 1); 1522 } 1523 } 1524 vcheckspace(); 1525 mtx_unlock(&vnode_free_list_mtx); 1526 } 1527 1528 /* 1529 * This hack is fragile, especially if desiredvnodes or wantvnodes are 1530 * misconfgured or changed significantly. Reducing desiredvnodes below 1531 * the reserved amount should cause bizarre behaviour like reducing it 1532 * below the number of active vnodes -- the system will try to reduce 1533 * numvnodes to match, but should fail, so the subtraction below should 1534 * not overflow. 1535 */ 1536 void 1537 getnewvnode_drop_reserve(void) 1538 { 1539 struct thread *td; 1540 1541 td = curthread; 1542 atomic_subtract_long(&numvnodes, td->td_vp_reserv); 1543 td->td_vp_reserv = 0; 1544 } 1545 1546 /* 1547 * Return the next vnode from the free list. 1548 */ 1549 int 1550 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1551 struct vnode **vpp) 1552 { 1553 struct vnode *vp; 1554 struct thread *td; 1555 struct lock_object *lo; 1556 static int cyclecount; 1557 int error __unused; 1558 1559 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1560 1561 KASSERT(vops->registered, 1562 ("%s: not registered vector op %p\n", __func__, vops)); 1563 1564 vp = NULL; 1565 td = curthread; 1566 if (td->td_vp_reserv > 0) { 1567 td->td_vp_reserv -= 1; 1568 goto alloc; 1569 } 1570 mtx_lock(&vnode_free_list_mtx); 1571 if (numvnodes < desiredvnodes) 1572 cyclecount = 0; 1573 else if (cyclecount++ >= freevnodes) { 1574 cyclecount = 0; 1575 vstir = 1; 1576 } 1577 /* 1578 * Grow the vnode cache if it will not be above its target max 1579 * after growing. Otherwise, if the free list is nonempty, try 1580 * to reclaim 1 item from it before growing the cache (possibly 1581 * above its target max if the reclamation failed or is delayed). 1582 * Otherwise, wait for some space. In all cases, schedule 1583 * vnlru_proc() if we are getting short of space. The watermarks 1584 * should be chosen so that we never wait or even reclaim from 1585 * the free list to below its target minimum. 1586 */ 1587 if (numvnodes + 1 <= desiredvnodes) 1588 ; 1589 else if (freevnodes > 0) 1590 vnlru_free_locked(1, NULL); 1591 else { 1592 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag & 1593 MNTK_SUSPEND)); 1594 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 1595 if (error != 0) { 1596 mtx_unlock(&vnode_free_list_mtx); 1597 return (error); 1598 } 1599 #endif 1600 } 1601 vcheckspace(); 1602 atomic_add_long(&numvnodes, 1); 1603 mtx_unlock(&vnode_free_list_mtx); 1604 alloc: 1605 counter_u64_add(vnodes_created, 1); 1606 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 1607 /* 1608 * Locks are given the generic name "vnode" when created. 1609 * Follow the historic practice of using the filesystem 1610 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1611 * 1612 * Locks live in a witness group keyed on their name. Thus, 1613 * when a lock is renamed, it must also move from the witness 1614 * group of its old name to the witness group of its new name. 1615 * 1616 * The change only needs to be made when the vnode moves 1617 * from one filesystem type to another. We ensure that each 1618 * filesystem use a single static name pointer for its tag so 1619 * that we can compare pointers rather than doing a strcmp(). 1620 */ 1621 lo = &vp->v_vnlock->lock_object; 1622 if (lo->lo_name != tag) { 1623 lo->lo_name = tag; 1624 WITNESS_DESTROY(lo); 1625 WITNESS_INIT(lo, tag); 1626 } 1627 /* 1628 * By default, don't allow shared locks unless filesystems opt-in. 1629 */ 1630 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1631 /* 1632 * Finalize various vnode identity bits. 1633 */ 1634 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1635 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1636 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1637 vp->v_type = VNON; 1638 vp->v_tag = tag; 1639 vp->v_op = vops; 1640 v_init_counters(vp); 1641 vp->v_bufobj.bo_ops = &buf_ops_bio; 1642 #ifdef DIAGNOSTIC 1643 if (mp == NULL && vops != &dead_vnodeops) 1644 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1645 #endif 1646 #ifdef MAC 1647 mac_vnode_init(vp); 1648 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1649 mac_vnode_associate_singlelabel(mp, vp); 1650 #endif 1651 if (mp != NULL) { 1652 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1653 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1654 vp->v_vflag |= VV_NOKNOTE; 1655 } 1656 1657 /* 1658 * For the filesystems which do not use vfs_hash_insert(), 1659 * still initialize v_hash to have vfs_hash_index() useful. 1660 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1661 * its own hashing. 1662 */ 1663 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1664 1665 *vpp = vp; 1666 return (0); 1667 } 1668 1669 static void 1670 freevnode(struct vnode *vp) 1671 { 1672 struct bufobj *bo; 1673 1674 /* 1675 * The vnode has been marked for destruction, so free it. 1676 * 1677 * The vnode will be returned to the zone where it will 1678 * normally remain until it is needed for another vnode. We 1679 * need to cleanup (or verify that the cleanup has already 1680 * been done) any residual data left from its current use 1681 * so as not to contaminate the freshly allocated vnode. 1682 */ 1683 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 1684 atomic_subtract_long(&numvnodes, 1); 1685 bo = &vp->v_bufobj; 1686 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 1687 ("cleaned vnode still on the free list.")); 1688 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 1689 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 1690 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 1691 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 1692 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 1693 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 1694 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 1695 ("clean blk trie not empty")); 1696 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 1697 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 1698 ("dirty blk trie not empty")); 1699 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 1700 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 1701 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 1702 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 1703 ("Dangling rangelock waiters")); 1704 VI_UNLOCK(vp); 1705 #ifdef MAC 1706 mac_vnode_destroy(vp); 1707 #endif 1708 if (vp->v_pollinfo != NULL) { 1709 destroy_vpollinfo(vp->v_pollinfo); 1710 vp->v_pollinfo = NULL; 1711 } 1712 #ifdef INVARIANTS 1713 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 1714 vp->v_op = NULL; 1715 #endif 1716 vp->v_mountedhere = NULL; 1717 vp->v_unpcb = NULL; 1718 vp->v_rdev = NULL; 1719 vp->v_fifoinfo = NULL; 1720 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 1721 vp->v_irflag = 0; 1722 vp->v_iflag = 0; 1723 vp->v_vflag = 0; 1724 bo->bo_flag = 0; 1725 uma_zfree(vnode_zone, vp); 1726 } 1727 1728 /* 1729 * Delete from old mount point vnode list, if on one. 1730 */ 1731 static void 1732 delmntque(struct vnode *vp) 1733 { 1734 struct mount *mp; 1735 1736 mp = vp->v_mount; 1737 if (mp == NULL) 1738 return; 1739 MNT_ILOCK(mp); 1740 VI_LOCK(vp); 1741 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize, 1742 ("Active vnode list size %d > Vnode list size %d", 1743 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize)); 1744 if (vp->v_iflag & VI_ACTIVE) { 1745 vp->v_iflag &= ~VI_ACTIVE; 1746 mtx_lock(&mp->mnt_listmtx); 1747 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); 1748 mp->mnt_activevnodelistsize--; 1749 mtx_unlock(&mp->mnt_listmtx); 1750 } 1751 vp->v_mount = NULL; 1752 VI_UNLOCK(vp); 1753 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1754 ("bad mount point vnode list size")); 1755 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1756 mp->mnt_nvnodelistsize--; 1757 MNT_REL(mp); 1758 MNT_IUNLOCK(mp); 1759 } 1760 1761 static void 1762 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1763 { 1764 1765 vp->v_data = NULL; 1766 vp->v_op = &dead_vnodeops; 1767 vgone(vp); 1768 vput(vp); 1769 } 1770 1771 /* 1772 * Insert into list of vnodes for the new mount point, if available. 1773 */ 1774 int 1775 insmntque1(struct vnode *vp, struct mount *mp, 1776 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1777 { 1778 1779 KASSERT(vp->v_mount == NULL, 1780 ("insmntque: vnode already on per mount vnode list")); 1781 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1782 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1783 1784 /* 1785 * We acquire the vnode interlock early to ensure that the 1786 * vnode cannot be recycled by another process releasing a 1787 * holdcnt on it before we get it on both the vnode list 1788 * and the active vnode list. The mount mutex protects only 1789 * manipulation of the vnode list and the vnode freelist 1790 * mutex protects only manipulation of the active vnode list. 1791 * Hence the need to hold the vnode interlock throughout. 1792 */ 1793 MNT_ILOCK(mp); 1794 VI_LOCK(vp); 1795 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && 1796 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1797 mp->mnt_nvnodelistsize == 0)) && 1798 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1799 VI_UNLOCK(vp); 1800 MNT_IUNLOCK(mp); 1801 if (dtr != NULL) 1802 dtr(vp, dtr_arg); 1803 return (EBUSY); 1804 } 1805 vp->v_mount = mp; 1806 MNT_REF(mp); 1807 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1808 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1809 ("neg mount point vnode list size")); 1810 mp->mnt_nvnodelistsize++; 1811 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1812 ("Activating already active vnode")); 1813 vp->v_iflag |= VI_ACTIVE; 1814 mtx_lock(&mp->mnt_listmtx); 1815 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 1816 mp->mnt_activevnodelistsize++; 1817 mtx_unlock(&mp->mnt_listmtx); 1818 VI_UNLOCK(vp); 1819 MNT_IUNLOCK(mp); 1820 return (0); 1821 } 1822 1823 int 1824 insmntque(struct vnode *vp, struct mount *mp) 1825 { 1826 1827 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1828 } 1829 1830 /* 1831 * Flush out and invalidate all buffers associated with a bufobj 1832 * Called with the underlying object locked. 1833 */ 1834 int 1835 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1836 { 1837 int error; 1838 1839 BO_LOCK(bo); 1840 if (flags & V_SAVE) { 1841 error = bufobj_wwait(bo, slpflag, slptimeo); 1842 if (error) { 1843 BO_UNLOCK(bo); 1844 return (error); 1845 } 1846 if (bo->bo_dirty.bv_cnt > 0) { 1847 BO_UNLOCK(bo); 1848 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1849 return (error); 1850 /* 1851 * XXX We could save a lock/unlock if this was only 1852 * enabled under INVARIANTS 1853 */ 1854 BO_LOCK(bo); 1855 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1856 panic("vinvalbuf: dirty bufs"); 1857 } 1858 } 1859 /* 1860 * If you alter this loop please notice that interlock is dropped and 1861 * reacquired in flushbuflist. Special care is needed to ensure that 1862 * no race conditions occur from this. 1863 */ 1864 do { 1865 error = flushbuflist(&bo->bo_clean, 1866 flags, bo, slpflag, slptimeo); 1867 if (error == 0 && !(flags & V_CLEANONLY)) 1868 error = flushbuflist(&bo->bo_dirty, 1869 flags, bo, slpflag, slptimeo); 1870 if (error != 0 && error != EAGAIN) { 1871 BO_UNLOCK(bo); 1872 return (error); 1873 } 1874 } while (error != 0); 1875 1876 /* 1877 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1878 * have write I/O in-progress but if there is a VM object then the 1879 * VM object can also have read-I/O in-progress. 1880 */ 1881 do { 1882 bufobj_wwait(bo, 0, 0); 1883 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) { 1884 BO_UNLOCK(bo); 1885 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx"); 1886 BO_LOCK(bo); 1887 } 1888 } while (bo->bo_numoutput > 0); 1889 BO_UNLOCK(bo); 1890 1891 /* 1892 * Destroy the copy in the VM cache, too. 1893 */ 1894 if (bo->bo_object != NULL && 1895 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1896 VM_OBJECT_WLOCK(bo->bo_object); 1897 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1898 OBJPR_CLEANONLY : 0); 1899 VM_OBJECT_WUNLOCK(bo->bo_object); 1900 } 1901 1902 #ifdef INVARIANTS 1903 BO_LOCK(bo); 1904 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1905 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1906 bo->bo_clean.bv_cnt > 0)) 1907 panic("vinvalbuf: flush failed"); 1908 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1909 bo->bo_dirty.bv_cnt > 0) 1910 panic("vinvalbuf: flush dirty failed"); 1911 BO_UNLOCK(bo); 1912 #endif 1913 return (0); 1914 } 1915 1916 /* 1917 * Flush out and invalidate all buffers associated with a vnode. 1918 * Called with the underlying object locked. 1919 */ 1920 int 1921 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1922 { 1923 1924 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1925 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1926 if (vp->v_object != NULL && vp->v_object->handle != vp) 1927 return (0); 1928 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1929 } 1930 1931 /* 1932 * Flush out buffers on the specified list. 1933 * 1934 */ 1935 static int 1936 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1937 int slptimeo) 1938 { 1939 struct buf *bp, *nbp; 1940 int retval, error; 1941 daddr_t lblkno; 1942 b_xflags_t xflags; 1943 1944 ASSERT_BO_WLOCKED(bo); 1945 1946 retval = 0; 1947 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1948 /* 1949 * If we are flushing both V_NORMAL and V_ALT buffers then 1950 * do not skip any buffers. If we are flushing only V_NORMAL 1951 * buffers then skip buffers marked as BX_ALTDATA. If we are 1952 * flushing only V_ALT buffers then skip buffers not marked 1953 * as BX_ALTDATA. 1954 */ 1955 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 1956 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 1957 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 1958 continue; 1959 } 1960 if (nbp != NULL) { 1961 lblkno = nbp->b_lblkno; 1962 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1963 } 1964 retval = EAGAIN; 1965 error = BUF_TIMELOCK(bp, 1966 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1967 "flushbuf", slpflag, slptimeo); 1968 if (error) { 1969 BO_LOCK(bo); 1970 return (error != ENOLCK ? error : EAGAIN); 1971 } 1972 KASSERT(bp->b_bufobj == bo, 1973 ("bp %p wrong b_bufobj %p should be %p", 1974 bp, bp->b_bufobj, bo)); 1975 /* 1976 * XXX Since there are no node locks for NFS, I 1977 * believe there is a slight chance that a delayed 1978 * write will occur while sleeping just above, so 1979 * check for it. 1980 */ 1981 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1982 (flags & V_SAVE)) { 1983 bremfree(bp); 1984 bp->b_flags |= B_ASYNC; 1985 bwrite(bp); 1986 BO_LOCK(bo); 1987 return (EAGAIN); /* XXX: why not loop ? */ 1988 } 1989 bremfree(bp); 1990 bp->b_flags |= (B_INVAL | B_RELBUF); 1991 bp->b_flags &= ~B_ASYNC; 1992 brelse(bp); 1993 BO_LOCK(bo); 1994 if (nbp == NULL) 1995 break; 1996 nbp = gbincore(bo, lblkno); 1997 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1998 != xflags) 1999 break; /* nbp invalid */ 2000 } 2001 return (retval); 2002 } 2003 2004 int 2005 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 2006 { 2007 struct buf *bp; 2008 int error; 2009 daddr_t lblkno; 2010 2011 ASSERT_BO_LOCKED(bo); 2012 2013 for (lblkno = startn;;) { 2014 again: 2015 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 2016 if (bp == NULL || bp->b_lblkno >= endn || 2017 bp->b_lblkno < startn) 2018 break; 2019 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 2020 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 2021 if (error != 0) { 2022 BO_RLOCK(bo); 2023 if (error == ENOLCK) 2024 goto again; 2025 return (error); 2026 } 2027 KASSERT(bp->b_bufobj == bo, 2028 ("bp %p wrong b_bufobj %p should be %p", 2029 bp, bp->b_bufobj, bo)); 2030 lblkno = bp->b_lblkno + 1; 2031 if ((bp->b_flags & B_MANAGED) == 0) 2032 bremfree(bp); 2033 bp->b_flags |= B_RELBUF; 2034 /* 2035 * In the VMIO case, use the B_NOREUSE flag to hint that the 2036 * pages backing each buffer in the range are unlikely to be 2037 * reused. Dirty buffers will have the hint applied once 2038 * they've been written. 2039 */ 2040 if ((bp->b_flags & B_VMIO) != 0) 2041 bp->b_flags |= B_NOREUSE; 2042 brelse(bp); 2043 BO_RLOCK(bo); 2044 } 2045 return (0); 2046 } 2047 2048 /* 2049 * Truncate a file's buffer and pages to a specified length. This 2050 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 2051 * sync activity. 2052 */ 2053 int 2054 vtruncbuf(struct vnode *vp, off_t length, int blksize) 2055 { 2056 struct buf *bp, *nbp; 2057 struct bufobj *bo; 2058 daddr_t startlbn; 2059 2060 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 2061 vp, blksize, (uintmax_t)length); 2062 2063 /* 2064 * Round up to the *next* lbn. 2065 */ 2066 startlbn = howmany(length, blksize); 2067 2068 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 2069 2070 bo = &vp->v_bufobj; 2071 restart_unlocked: 2072 BO_LOCK(bo); 2073 2074 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 2075 ; 2076 2077 if (length > 0) { 2078 restartsync: 2079 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2080 if (bp->b_lblkno > 0) 2081 continue; 2082 /* 2083 * Since we hold the vnode lock this should only 2084 * fail if we're racing with the buf daemon. 2085 */ 2086 if (BUF_LOCK(bp, 2087 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2088 BO_LOCKPTR(bo)) == ENOLCK) 2089 goto restart_unlocked; 2090 2091 VNASSERT((bp->b_flags & B_DELWRI), vp, 2092 ("buf(%p) on dirty queue without DELWRI", bp)); 2093 2094 bremfree(bp); 2095 bawrite(bp); 2096 BO_LOCK(bo); 2097 goto restartsync; 2098 } 2099 } 2100 2101 bufobj_wwait(bo, 0, 0); 2102 BO_UNLOCK(bo); 2103 vnode_pager_setsize(vp, length); 2104 2105 return (0); 2106 } 2107 2108 /* 2109 * Invalidate the cached pages of a file's buffer within the range of block 2110 * numbers [startlbn, endlbn). 2111 */ 2112 void 2113 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2114 int blksize) 2115 { 2116 struct bufobj *bo; 2117 off_t start, end; 2118 2119 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2120 2121 start = blksize * startlbn; 2122 end = blksize * endlbn; 2123 2124 bo = &vp->v_bufobj; 2125 BO_LOCK(bo); 2126 MPASS(blksize == bo->bo_bsize); 2127 2128 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2129 ; 2130 2131 BO_UNLOCK(bo); 2132 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2133 } 2134 2135 static int 2136 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2137 daddr_t startlbn, daddr_t endlbn) 2138 { 2139 struct buf *bp, *nbp; 2140 bool anyfreed; 2141 2142 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2143 ASSERT_BO_LOCKED(bo); 2144 2145 do { 2146 anyfreed = false; 2147 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2148 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2149 continue; 2150 if (BUF_LOCK(bp, 2151 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2152 BO_LOCKPTR(bo)) == ENOLCK) { 2153 BO_LOCK(bo); 2154 return (EAGAIN); 2155 } 2156 2157 bremfree(bp); 2158 bp->b_flags |= B_INVAL | B_RELBUF; 2159 bp->b_flags &= ~B_ASYNC; 2160 brelse(bp); 2161 anyfreed = true; 2162 2163 BO_LOCK(bo); 2164 if (nbp != NULL && 2165 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2166 nbp->b_vp != vp || 2167 (nbp->b_flags & B_DELWRI) != 0)) 2168 return (EAGAIN); 2169 } 2170 2171 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2172 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2173 continue; 2174 if (BUF_LOCK(bp, 2175 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2176 BO_LOCKPTR(bo)) == ENOLCK) { 2177 BO_LOCK(bo); 2178 return (EAGAIN); 2179 } 2180 bremfree(bp); 2181 bp->b_flags |= B_INVAL | B_RELBUF; 2182 bp->b_flags &= ~B_ASYNC; 2183 brelse(bp); 2184 anyfreed = true; 2185 2186 BO_LOCK(bo); 2187 if (nbp != NULL && 2188 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2189 (nbp->b_vp != vp) || 2190 (nbp->b_flags & B_DELWRI) == 0)) 2191 return (EAGAIN); 2192 } 2193 } while (anyfreed); 2194 return (0); 2195 } 2196 2197 static void 2198 buf_vlist_remove(struct buf *bp) 2199 { 2200 struct bufv *bv; 2201 2202 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2203 ASSERT_BO_WLOCKED(bp->b_bufobj); 2204 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 2205 (BX_VNDIRTY|BX_VNCLEAN), 2206 ("buf_vlist_remove: Buf %p is on two lists", bp)); 2207 if (bp->b_xflags & BX_VNDIRTY) 2208 bv = &bp->b_bufobj->bo_dirty; 2209 else 2210 bv = &bp->b_bufobj->bo_clean; 2211 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2212 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2213 bv->bv_cnt--; 2214 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2215 } 2216 2217 /* 2218 * Add the buffer to the sorted clean or dirty block list. 2219 * 2220 * NOTE: xflags is passed as a constant, optimizing this inline function! 2221 */ 2222 static void 2223 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2224 { 2225 struct bufv *bv; 2226 struct buf *n; 2227 int error; 2228 2229 ASSERT_BO_WLOCKED(bo); 2230 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2231 ("dead bo %p", bo)); 2232 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2233 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2234 bp->b_xflags |= xflags; 2235 if (xflags & BX_VNDIRTY) 2236 bv = &bo->bo_dirty; 2237 else 2238 bv = &bo->bo_clean; 2239 2240 /* 2241 * Keep the list ordered. Optimize empty list insertion. Assume 2242 * we tend to grow at the tail so lookup_le should usually be cheaper 2243 * than _ge. 2244 */ 2245 if (bv->bv_cnt == 0 || 2246 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2247 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2248 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2249 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2250 else 2251 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2252 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2253 if (error) 2254 panic("buf_vlist_add: Preallocated nodes insufficient."); 2255 bv->bv_cnt++; 2256 } 2257 2258 /* 2259 * Look up a buffer using the buffer tries. 2260 */ 2261 struct buf * 2262 gbincore(struct bufobj *bo, daddr_t lblkno) 2263 { 2264 struct buf *bp; 2265 2266 ASSERT_BO_LOCKED(bo); 2267 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2268 if (bp != NULL) 2269 return (bp); 2270 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2271 } 2272 2273 /* 2274 * Associate a buffer with a vnode. 2275 */ 2276 void 2277 bgetvp(struct vnode *vp, struct buf *bp) 2278 { 2279 struct bufobj *bo; 2280 2281 bo = &vp->v_bufobj; 2282 ASSERT_BO_WLOCKED(bo); 2283 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2284 2285 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2286 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2287 ("bgetvp: bp already attached! %p", bp)); 2288 2289 vhold(vp); 2290 bp->b_vp = vp; 2291 bp->b_bufobj = bo; 2292 /* 2293 * Insert onto list for new vnode. 2294 */ 2295 buf_vlist_add(bp, bo, BX_VNCLEAN); 2296 } 2297 2298 /* 2299 * Disassociate a buffer from a vnode. 2300 */ 2301 void 2302 brelvp(struct buf *bp) 2303 { 2304 struct bufobj *bo; 2305 struct vnode *vp; 2306 2307 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2308 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2309 2310 /* 2311 * Delete from old vnode list, if on one. 2312 */ 2313 vp = bp->b_vp; /* XXX */ 2314 bo = bp->b_bufobj; 2315 BO_LOCK(bo); 2316 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2317 buf_vlist_remove(bp); 2318 else 2319 panic("brelvp: Buffer %p not on queue.", bp); 2320 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2321 bo->bo_flag &= ~BO_ONWORKLST; 2322 mtx_lock(&sync_mtx); 2323 LIST_REMOVE(bo, bo_synclist); 2324 syncer_worklist_len--; 2325 mtx_unlock(&sync_mtx); 2326 } 2327 bp->b_vp = NULL; 2328 bp->b_bufobj = NULL; 2329 BO_UNLOCK(bo); 2330 vdrop(vp); 2331 } 2332 2333 /* 2334 * Add an item to the syncer work queue. 2335 */ 2336 static void 2337 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2338 { 2339 int slot; 2340 2341 ASSERT_BO_WLOCKED(bo); 2342 2343 mtx_lock(&sync_mtx); 2344 if (bo->bo_flag & BO_ONWORKLST) 2345 LIST_REMOVE(bo, bo_synclist); 2346 else { 2347 bo->bo_flag |= BO_ONWORKLST; 2348 syncer_worklist_len++; 2349 } 2350 2351 if (delay > syncer_maxdelay - 2) 2352 delay = syncer_maxdelay - 2; 2353 slot = (syncer_delayno + delay) & syncer_mask; 2354 2355 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2356 mtx_unlock(&sync_mtx); 2357 } 2358 2359 static int 2360 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2361 { 2362 int error, len; 2363 2364 mtx_lock(&sync_mtx); 2365 len = syncer_worklist_len - sync_vnode_count; 2366 mtx_unlock(&sync_mtx); 2367 error = SYSCTL_OUT(req, &len, sizeof(len)); 2368 return (error); 2369 } 2370 2371 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 2372 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2373 2374 static struct proc *updateproc; 2375 static void sched_sync(void); 2376 static struct kproc_desc up_kp = { 2377 "syncer", 2378 sched_sync, 2379 &updateproc 2380 }; 2381 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2382 2383 static int 2384 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2385 { 2386 struct vnode *vp; 2387 struct mount *mp; 2388 2389 *bo = LIST_FIRST(slp); 2390 if (*bo == NULL) 2391 return (0); 2392 vp = bo2vnode(*bo); 2393 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2394 return (1); 2395 /* 2396 * We use vhold in case the vnode does not 2397 * successfully sync. vhold prevents the vnode from 2398 * going away when we unlock the sync_mtx so that 2399 * we can acquire the vnode interlock. 2400 */ 2401 vholdl(vp); 2402 mtx_unlock(&sync_mtx); 2403 VI_UNLOCK(vp); 2404 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2405 vdrop(vp); 2406 mtx_lock(&sync_mtx); 2407 return (*bo == LIST_FIRST(slp)); 2408 } 2409 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2410 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2411 VOP_UNLOCK(vp); 2412 vn_finished_write(mp); 2413 BO_LOCK(*bo); 2414 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2415 /* 2416 * Put us back on the worklist. The worklist 2417 * routine will remove us from our current 2418 * position and then add us back in at a later 2419 * position. 2420 */ 2421 vn_syncer_add_to_worklist(*bo, syncdelay); 2422 } 2423 BO_UNLOCK(*bo); 2424 vdrop(vp); 2425 mtx_lock(&sync_mtx); 2426 return (0); 2427 } 2428 2429 static int first_printf = 1; 2430 2431 /* 2432 * System filesystem synchronizer daemon. 2433 */ 2434 static void 2435 sched_sync(void) 2436 { 2437 struct synclist *next, *slp; 2438 struct bufobj *bo; 2439 long starttime; 2440 struct thread *td = curthread; 2441 int last_work_seen; 2442 int net_worklist_len; 2443 int syncer_final_iter; 2444 int error; 2445 2446 last_work_seen = 0; 2447 syncer_final_iter = 0; 2448 syncer_state = SYNCER_RUNNING; 2449 starttime = time_uptime; 2450 td->td_pflags |= TDP_NORUNNINGBUF; 2451 2452 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2453 SHUTDOWN_PRI_LAST); 2454 2455 mtx_lock(&sync_mtx); 2456 for (;;) { 2457 if (syncer_state == SYNCER_FINAL_DELAY && 2458 syncer_final_iter == 0) { 2459 mtx_unlock(&sync_mtx); 2460 kproc_suspend_check(td->td_proc); 2461 mtx_lock(&sync_mtx); 2462 } 2463 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2464 if (syncer_state != SYNCER_RUNNING && 2465 starttime != time_uptime) { 2466 if (first_printf) { 2467 printf("\nSyncing disks, vnodes remaining... "); 2468 first_printf = 0; 2469 } 2470 printf("%d ", net_worklist_len); 2471 } 2472 starttime = time_uptime; 2473 2474 /* 2475 * Push files whose dirty time has expired. Be careful 2476 * of interrupt race on slp queue. 2477 * 2478 * Skip over empty worklist slots when shutting down. 2479 */ 2480 do { 2481 slp = &syncer_workitem_pending[syncer_delayno]; 2482 syncer_delayno += 1; 2483 if (syncer_delayno == syncer_maxdelay) 2484 syncer_delayno = 0; 2485 next = &syncer_workitem_pending[syncer_delayno]; 2486 /* 2487 * If the worklist has wrapped since the 2488 * it was emptied of all but syncer vnodes, 2489 * switch to the FINAL_DELAY state and run 2490 * for one more second. 2491 */ 2492 if (syncer_state == SYNCER_SHUTTING_DOWN && 2493 net_worklist_len == 0 && 2494 last_work_seen == syncer_delayno) { 2495 syncer_state = SYNCER_FINAL_DELAY; 2496 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2497 } 2498 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2499 syncer_worklist_len > 0); 2500 2501 /* 2502 * Keep track of the last time there was anything 2503 * on the worklist other than syncer vnodes. 2504 * Return to the SHUTTING_DOWN state if any 2505 * new work appears. 2506 */ 2507 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2508 last_work_seen = syncer_delayno; 2509 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2510 syncer_state = SYNCER_SHUTTING_DOWN; 2511 while (!LIST_EMPTY(slp)) { 2512 error = sync_vnode(slp, &bo, td); 2513 if (error == 1) { 2514 LIST_REMOVE(bo, bo_synclist); 2515 LIST_INSERT_HEAD(next, bo, bo_synclist); 2516 continue; 2517 } 2518 2519 if (first_printf == 0) { 2520 /* 2521 * Drop the sync mutex, because some watchdog 2522 * drivers need to sleep while patting 2523 */ 2524 mtx_unlock(&sync_mtx); 2525 wdog_kern_pat(WD_LASTVAL); 2526 mtx_lock(&sync_mtx); 2527 } 2528 2529 } 2530 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2531 syncer_final_iter--; 2532 /* 2533 * The variable rushjob allows the kernel to speed up the 2534 * processing of the filesystem syncer process. A rushjob 2535 * value of N tells the filesystem syncer to process the next 2536 * N seconds worth of work on its queue ASAP. Currently rushjob 2537 * is used by the soft update code to speed up the filesystem 2538 * syncer process when the incore state is getting so far 2539 * ahead of the disk that the kernel memory pool is being 2540 * threatened with exhaustion. 2541 */ 2542 if (rushjob > 0) { 2543 rushjob -= 1; 2544 continue; 2545 } 2546 /* 2547 * Just sleep for a short period of time between 2548 * iterations when shutting down to allow some I/O 2549 * to happen. 2550 * 2551 * If it has taken us less than a second to process the 2552 * current work, then wait. Otherwise start right over 2553 * again. We can still lose time if any single round 2554 * takes more than two seconds, but it does not really 2555 * matter as we are just trying to generally pace the 2556 * filesystem activity. 2557 */ 2558 if (syncer_state != SYNCER_RUNNING || 2559 time_uptime == starttime) { 2560 thread_lock(td); 2561 sched_prio(td, PPAUSE); 2562 thread_unlock(td); 2563 } 2564 if (syncer_state != SYNCER_RUNNING) 2565 cv_timedwait(&sync_wakeup, &sync_mtx, 2566 hz / SYNCER_SHUTDOWN_SPEEDUP); 2567 else if (time_uptime == starttime) 2568 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2569 } 2570 } 2571 2572 /* 2573 * Request the syncer daemon to speed up its work. 2574 * We never push it to speed up more than half of its 2575 * normal turn time, otherwise it could take over the cpu. 2576 */ 2577 int 2578 speedup_syncer(void) 2579 { 2580 int ret = 0; 2581 2582 mtx_lock(&sync_mtx); 2583 if (rushjob < syncdelay / 2) { 2584 rushjob += 1; 2585 stat_rush_requests += 1; 2586 ret = 1; 2587 } 2588 mtx_unlock(&sync_mtx); 2589 cv_broadcast(&sync_wakeup); 2590 return (ret); 2591 } 2592 2593 /* 2594 * Tell the syncer to speed up its work and run though its work 2595 * list several times, then tell it to shut down. 2596 */ 2597 static void 2598 syncer_shutdown(void *arg, int howto) 2599 { 2600 2601 if (howto & RB_NOSYNC) 2602 return; 2603 mtx_lock(&sync_mtx); 2604 syncer_state = SYNCER_SHUTTING_DOWN; 2605 rushjob = 0; 2606 mtx_unlock(&sync_mtx); 2607 cv_broadcast(&sync_wakeup); 2608 kproc_shutdown(arg, howto); 2609 } 2610 2611 void 2612 syncer_suspend(void) 2613 { 2614 2615 syncer_shutdown(updateproc, 0); 2616 } 2617 2618 void 2619 syncer_resume(void) 2620 { 2621 2622 mtx_lock(&sync_mtx); 2623 first_printf = 1; 2624 syncer_state = SYNCER_RUNNING; 2625 mtx_unlock(&sync_mtx); 2626 cv_broadcast(&sync_wakeup); 2627 kproc_resume(updateproc); 2628 } 2629 2630 /* 2631 * Reassign a buffer from one vnode to another. 2632 * Used to assign file specific control information 2633 * (indirect blocks) to the vnode to which they belong. 2634 */ 2635 void 2636 reassignbuf(struct buf *bp) 2637 { 2638 struct vnode *vp; 2639 struct bufobj *bo; 2640 int delay; 2641 #ifdef INVARIANTS 2642 struct bufv *bv; 2643 #endif 2644 2645 vp = bp->b_vp; 2646 bo = bp->b_bufobj; 2647 ++reassignbufcalls; 2648 2649 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2650 bp, bp->b_vp, bp->b_flags); 2651 /* 2652 * B_PAGING flagged buffers cannot be reassigned because their vp 2653 * is not fully linked in. 2654 */ 2655 if (bp->b_flags & B_PAGING) 2656 panic("cannot reassign paging buffer"); 2657 2658 /* 2659 * Delete from old vnode list, if on one. 2660 */ 2661 BO_LOCK(bo); 2662 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2663 buf_vlist_remove(bp); 2664 else 2665 panic("reassignbuf: Buffer %p not on queue.", bp); 2666 /* 2667 * If dirty, put on list of dirty buffers; otherwise insert onto list 2668 * of clean buffers. 2669 */ 2670 if (bp->b_flags & B_DELWRI) { 2671 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2672 switch (vp->v_type) { 2673 case VDIR: 2674 delay = dirdelay; 2675 break; 2676 case VCHR: 2677 delay = metadelay; 2678 break; 2679 default: 2680 delay = filedelay; 2681 } 2682 vn_syncer_add_to_worklist(bo, delay); 2683 } 2684 buf_vlist_add(bp, bo, BX_VNDIRTY); 2685 } else { 2686 buf_vlist_add(bp, bo, BX_VNCLEAN); 2687 2688 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2689 mtx_lock(&sync_mtx); 2690 LIST_REMOVE(bo, bo_synclist); 2691 syncer_worklist_len--; 2692 mtx_unlock(&sync_mtx); 2693 bo->bo_flag &= ~BO_ONWORKLST; 2694 } 2695 } 2696 #ifdef INVARIANTS 2697 bv = &bo->bo_clean; 2698 bp = TAILQ_FIRST(&bv->bv_hd); 2699 KASSERT(bp == NULL || bp->b_bufobj == bo, 2700 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2701 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2702 KASSERT(bp == NULL || bp->b_bufobj == bo, 2703 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2704 bv = &bo->bo_dirty; 2705 bp = TAILQ_FIRST(&bv->bv_hd); 2706 KASSERT(bp == NULL || bp->b_bufobj == bo, 2707 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2708 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2709 KASSERT(bp == NULL || bp->b_bufobj == bo, 2710 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2711 #endif 2712 BO_UNLOCK(bo); 2713 } 2714 2715 static void 2716 v_init_counters(struct vnode *vp) 2717 { 2718 2719 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2720 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2721 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2722 2723 refcount_init(&vp->v_holdcnt, 1); 2724 refcount_init(&vp->v_usecount, 1); 2725 } 2726 2727 /* 2728 * Increment si_usecount of the associated device, if any. 2729 */ 2730 static void 2731 v_incr_devcount(struct vnode *vp) 2732 { 2733 2734 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2735 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2736 dev_lock(); 2737 vp->v_rdev->si_usecount++; 2738 dev_unlock(); 2739 } 2740 } 2741 2742 /* 2743 * Decrement si_usecount of the associated device, if any. 2744 */ 2745 static void 2746 v_decr_devcount(struct vnode *vp) 2747 { 2748 2749 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2750 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2751 dev_lock(); 2752 vp->v_rdev->si_usecount--; 2753 dev_unlock(); 2754 } 2755 } 2756 2757 /* 2758 * Grab a particular vnode from the free list, increment its 2759 * reference count and lock it. VIRF_DOOMED is set if the vnode 2760 * is being destroyed. Only callers who specify LK_RETRY will 2761 * see doomed vnodes. If inactive processing was delayed in 2762 * vput try to do it here. 2763 * 2764 * Both holdcnt and usecount can be manipulated using atomics without holding 2765 * any locks except in these cases which require the vnode interlock: 2766 * holdcnt: 1->0 and 0->1 2767 * usecount: 0->1 2768 * 2769 * usecount is permitted to transition 1->0 without the interlock because 2770 * vnode is kept live by holdcnt. 2771 */ 2772 static enum vgetstate __always_inline 2773 _vget_prep(struct vnode *vp, bool interlock) 2774 { 2775 enum vgetstate vs; 2776 2777 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2778 vs = VGET_USECOUNT; 2779 } else { 2780 if (interlock) 2781 vholdl(vp); 2782 else 2783 vhold(vp); 2784 vs = VGET_HOLDCNT; 2785 } 2786 return (vs); 2787 } 2788 2789 enum vgetstate 2790 vget_prep(struct vnode *vp) 2791 { 2792 2793 return (_vget_prep(vp, false)); 2794 } 2795 2796 int 2797 vget(struct vnode *vp, int flags, struct thread *td) 2798 { 2799 enum vgetstate vs; 2800 2801 MPASS(td == curthread); 2802 2803 vs = _vget_prep(vp, (flags & LK_INTERLOCK) != 0); 2804 return (vget_finish(vp, flags, vs)); 2805 } 2806 2807 int 2808 vget_finish(struct vnode *vp, int flags, enum vgetstate vs) 2809 { 2810 int error, oweinact; 2811 2812 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2813 ("%s: invalid lock operation", __func__)); 2814 2815 if ((flags & LK_INTERLOCK) != 0) 2816 ASSERT_VI_LOCKED(vp, __func__); 2817 else 2818 ASSERT_VI_UNLOCKED(vp, __func__); 2819 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__)); 2820 if (vs == VGET_USECOUNT) { 2821 VNASSERT(vp->v_usecount > 0, vp, 2822 ("%s: vnode without usecount when VGET_USECOUNT was passed", 2823 __func__)); 2824 } 2825 2826 if ((error = vn_lock(vp, flags)) != 0) { 2827 if (vs == VGET_USECOUNT) 2828 vrele(vp); 2829 else 2830 vdrop(vp); 2831 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2832 vp); 2833 return (error); 2834 } 2835 2836 if (vs == VGET_USECOUNT) { 2837 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2838 ("%s: vnode with usecount and VI_OWEINACT set", __func__)); 2839 return (0); 2840 } 2841 2842 /* 2843 * We hold the vnode. If the usecount is 0 it will be utilized to keep 2844 * the vnode around. Otherwise someone else lended their hold count and 2845 * we have to drop ours. 2846 */ 2847 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2848 #ifdef INVARIANTS 2849 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2850 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2851 #else 2852 refcount_release(&vp->v_holdcnt); 2853 #endif 2854 VNODE_REFCOUNT_FENCE_ACQ(); 2855 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2856 ("%s: vnode with usecount and VI_OWEINACT set", __func__)); 2857 return (0); 2858 } 2859 2860 /* 2861 * We don't guarantee that any particular close will 2862 * trigger inactive processing so just make a best effort 2863 * here at preventing a reference to a removed file. If 2864 * we don't succeed no harm is done. 2865 * 2866 * Upgrade our holdcnt to a usecount. 2867 */ 2868 VI_LOCK(vp); 2869 /* 2870 * See the previous section. By the time we get here we may find 2871 * ourselves in the same spot. 2872 */ 2873 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2874 #ifdef INVARIANTS 2875 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1); 2876 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old)); 2877 #else 2878 refcount_release(&vp->v_holdcnt); 2879 #endif 2880 VNODE_REFCOUNT_FENCE_ACQ(); 2881 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2882 ("%s: vnode with usecount and VI_OWEINACT set", 2883 __func__)); 2884 VI_UNLOCK(vp); 2885 return (0); 2886 } 2887 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2888 oweinact = 0; 2889 } else { 2890 oweinact = 1; 2891 vp->v_iflag &= ~VI_OWEINACT; 2892 VNODE_REFCOUNT_FENCE_REL(); 2893 } 2894 v_incr_devcount(vp); 2895 refcount_acquire(&vp->v_usecount); 2896 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2897 (flags & LK_NOWAIT) == 0) 2898 vinactive(vp); 2899 VI_UNLOCK(vp); 2900 return (0); 2901 } 2902 2903 /* 2904 * Increase the reference (use) and hold count of a vnode. 2905 * This will also remove the vnode from the free list if it is presently free. 2906 */ 2907 void 2908 vref(struct vnode *vp) 2909 { 2910 2911 ASSERT_VI_UNLOCKED(vp, __func__); 2912 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2913 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2914 VNODE_REFCOUNT_FENCE_ACQ(); 2915 VNASSERT(vp->v_holdcnt > 0, vp, 2916 ("%s: active vnode not held", __func__)); 2917 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2918 ("%s: vnode with usecount and VI_OWEINACT set", __func__)); 2919 return; 2920 } 2921 VI_LOCK(vp); 2922 vrefl(vp); 2923 VI_UNLOCK(vp); 2924 } 2925 2926 void 2927 vrefl(struct vnode *vp) 2928 { 2929 2930 ASSERT_VI_LOCKED(vp, __func__); 2931 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2932 if (refcount_acquire_if_not_zero(&vp->v_usecount)) { 2933 VNODE_REFCOUNT_FENCE_ACQ(); 2934 VNASSERT(vp->v_holdcnt > 0, vp, 2935 ("%s: active vnode not held", __func__)); 2936 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2937 ("%s: vnode with usecount and VI_OWEINACT set", __func__)); 2938 return; 2939 } 2940 vholdl(vp); 2941 if ((vp->v_iflag & VI_OWEINACT) != 0) { 2942 vp->v_iflag &= ~VI_OWEINACT; 2943 VNODE_REFCOUNT_FENCE_REL(); 2944 } 2945 v_incr_devcount(vp); 2946 refcount_acquire(&vp->v_usecount); 2947 } 2948 2949 void 2950 vrefact(struct vnode *vp) 2951 { 2952 2953 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2954 #ifdef INVARIANTS 2955 int old = atomic_fetchadd_int(&vp->v_usecount, 1); 2956 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old)); 2957 #else 2958 refcount_acquire(&vp->v_usecount); 2959 #endif 2960 } 2961 2962 /* 2963 * Return reference count of a vnode. 2964 * 2965 * The results of this call are only guaranteed when some mechanism is used to 2966 * stop other processes from gaining references to the vnode. This may be the 2967 * case if the caller holds the only reference. This is also useful when stale 2968 * data is acceptable as race conditions may be accounted for by some other 2969 * means. 2970 */ 2971 int 2972 vrefcnt(struct vnode *vp) 2973 { 2974 2975 return (vp->v_usecount); 2976 } 2977 2978 enum vputx_op { VPUTX_VRELE, VPUTX_VPUT, VPUTX_VUNREF }; 2979 2980 /* 2981 * Decrement the use and hold counts for a vnode. 2982 * 2983 * See an explanation near vget() as to why atomic operation is safe. 2984 */ 2985 static void 2986 vputx(struct vnode *vp, enum vputx_op func) 2987 { 2988 int error; 2989 2990 KASSERT(vp != NULL, ("vputx: null vp")); 2991 if (func == VPUTX_VUNREF) 2992 ASSERT_VOP_LOCKED(vp, "vunref"); 2993 ASSERT_VI_UNLOCKED(vp, __func__); 2994 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 2995 ("%s: wrong ref counts", __func__)); 2996 2997 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2998 2999 /* 3000 * We want to hold the vnode until the inactive finishes to 3001 * prevent vgone() races. We drop the use count here and the 3002 * hold count below when we're done. 3003 * 3004 * If we release the last usecount we take ownership of the hold 3005 * count which provides liveness of the vnode, in which case we 3006 * have to vdrop. 3007 */ 3008 if (!refcount_release(&vp->v_usecount)) 3009 return; 3010 VI_LOCK(vp); 3011 v_decr_devcount(vp); 3012 /* 3013 * By the time we got here someone else might have transitioned 3014 * the count back to > 0. 3015 */ 3016 if (vp->v_usecount > 0) { 3017 vdropl(vp); 3018 return; 3019 } 3020 if (vp->v_iflag & VI_DOINGINACT) { 3021 vdropl(vp); 3022 return; 3023 } 3024 3025 /* 3026 * Check if the fs wants to perform inactive processing. Note we 3027 * may be only holding the interlock, in which case it is possible 3028 * someone else called vgone on the vnode and ->v_data is now NULL. 3029 * Since vgone performs inactive on its own there is nothing to do 3030 * here but to drop our hold count. 3031 */ 3032 if (__predict_false(VN_IS_DOOMED(vp)) || 3033 VOP_NEED_INACTIVE(vp) == 0) { 3034 vdropl(vp); 3035 return; 3036 } 3037 3038 /* 3039 * We must call VOP_INACTIVE with the node locked. Mark 3040 * as VI_DOINGINACT to avoid recursion. 3041 */ 3042 vp->v_iflag |= VI_OWEINACT; 3043 switch (func) { 3044 case VPUTX_VRELE: 3045 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 3046 VI_LOCK(vp); 3047 break; 3048 case VPUTX_VPUT: 3049 error = VOP_LOCK(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_NOWAIT); 3050 VI_LOCK(vp); 3051 break; 3052 case VPUTX_VUNREF: 3053 error = 0; 3054 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 3055 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 3056 VI_LOCK(vp); 3057 } 3058 break; 3059 } 3060 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, 3061 ("vnode with usecount and VI_OWEINACT set")); 3062 if (error == 0) { 3063 if (vp->v_iflag & VI_OWEINACT) 3064 vinactive(vp); 3065 if (func != VPUTX_VUNREF) 3066 VOP_UNLOCK(vp); 3067 } 3068 vdropl(vp); 3069 } 3070 3071 /* 3072 * Vnode put/release. 3073 * If count drops to zero, call inactive routine and return to freelist. 3074 */ 3075 void 3076 vrele(struct vnode *vp) 3077 { 3078 3079 vputx(vp, VPUTX_VRELE); 3080 } 3081 3082 /* 3083 * Release an already locked vnode. This give the same effects as 3084 * unlock+vrele(), but takes less time and avoids releasing and 3085 * re-aquiring the lock (as vrele() acquires the lock internally.) 3086 * 3087 * It is an invariant that all VOP_* calls operate on a held vnode. 3088 * We may be only having an implicit hold stemming from our usecount, 3089 * which we are about to release. If we unlock the vnode afterwards we 3090 * open a time window where someone else dropped the last usecount and 3091 * proceeded to free the vnode before our unlock finished. For this 3092 * reason we unlock the vnode early. This is a little bit wasteful as 3093 * it may be the vnode is exclusively locked and inactive processing is 3094 * needed, in which case we are adding work. 3095 */ 3096 void 3097 vput(struct vnode *vp) 3098 { 3099 3100 VOP_UNLOCK(vp); 3101 vputx(vp, VPUTX_VPUT); 3102 } 3103 3104 /* 3105 * Release an exclusively locked vnode. Do not unlock the vnode lock. 3106 */ 3107 void 3108 vunref(struct vnode *vp) 3109 { 3110 3111 vputx(vp, VPUTX_VUNREF); 3112 } 3113 3114 /* 3115 * Increase the hold count and activate if this is the first reference. 3116 */ 3117 static void 3118 vhold_activate(struct vnode *vp) 3119 { 3120 struct mount *mp; 3121 3122 ASSERT_VI_LOCKED(vp, __func__); 3123 VNASSERT(vp->v_holdcnt == 0, vp, 3124 ("%s: wrong hold count", __func__)); 3125 VNASSERT(vp->v_op != NULL, vp, 3126 ("%s: vnode already reclaimed.", __func__)); 3127 /* 3128 * Remove a vnode from the free list, mark it as in use, 3129 * and put it on the active list. 3130 */ 3131 VNASSERT(vp->v_mount != NULL, vp, 3132 ("_vhold: vnode not on per mount vnode list")); 3133 mp = vp->v_mount; 3134 mtx_lock(&mp->mnt_listmtx); 3135 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { 3136 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 3137 mp->mnt_tmpfreevnodelistsize--; 3138 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 3139 } else { 3140 mtx_lock(&vnode_free_list_mtx); 3141 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 3142 freevnodes--; 3143 mtx_unlock(&vnode_free_list_mtx); 3144 } 3145 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 3146 ("Activating already active vnode")); 3147 vp->v_iflag &= ~VI_FREE; 3148 vp->v_iflag |= VI_ACTIVE; 3149 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 3150 mp->mnt_activevnodelistsize++; 3151 mtx_unlock(&mp->mnt_listmtx); 3152 refcount_acquire(&vp->v_holdcnt); 3153 } 3154 3155 void 3156 vhold(struct vnode *vp) 3157 { 3158 3159 ASSERT_VI_UNLOCKED(vp, __func__); 3160 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3161 if (refcount_acquire_if_not_zero(&vp->v_holdcnt)) { 3162 VNODE_REFCOUNT_FENCE_ACQ(); 3163 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 3164 ("vhold: vnode with holdcnt is free")); 3165 return; 3166 } 3167 VI_LOCK(vp); 3168 vholdl(vp); 3169 VI_UNLOCK(vp); 3170 } 3171 3172 void 3173 vholdl(struct vnode *vp) 3174 { 3175 3176 ASSERT_VI_LOCKED(vp, __func__); 3177 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3178 if ((vp->v_iflag & VI_FREE) == 0) { 3179 refcount_acquire(&vp->v_holdcnt); 3180 return; 3181 } 3182 vhold_activate(vp); 3183 } 3184 3185 void 3186 vholdnz(struct vnode *vp) 3187 { 3188 3189 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3190 #ifdef INVARIANTS 3191 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 3192 VNASSERT(old > 0, vp, ("%s: wrong hold count %d", __func__, old)); 3193 #else 3194 atomic_add_int(&vp->v_holdcnt, 1); 3195 #endif 3196 } 3197 3198 /* 3199 * Drop the hold count of the vnode. If this is the last reference to 3200 * the vnode we place it on the free list unless it has been vgone'd 3201 * (marked VIRF_DOOMED) in which case we will free it. 3202 * 3203 * Because the vnode vm object keeps a hold reference on the vnode if 3204 * there is at least one resident non-cached page, the vnode cannot 3205 * leave the active list without the page cleanup done. 3206 */ 3207 static void 3208 vdrop_deactivate(struct vnode *vp) 3209 { 3210 struct mount *mp; 3211 3212 ASSERT_VI_LOCKED(vp, __func__); 3213 /* 3214 * Mark a vnode as free: remove it from its active list 3215 * and put it up for recycling on the freelist. 3216 */ 3217 VNASSERT(!VN_IS_DOOMED(vp), vp, 3218 ("vdrop: returning doomed vnode")); 3219 VNASSERT(vp->v_op != NULL, vp, 3220 ("vdrop: vnode already reclaimed.")); 3221 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 3222 ("vnode already free")); 3223 VNASSERT(vp->v_holdcnt == 0, vp, 3224 ("vdrop: freeing when we shouldn't")); 3225 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3226 mp = vp->v_mount; 3227 mtx_lock(&mp->mnt_listmtx); 3228 if (vp->v_iflag & VI_ACTIVE) { 3229 vp->v_iflag &= ~VI_ACTIVE; 3230 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); 3231 mp->mnt_activevnodelistsize--; 3232 } 3233 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 3234 mp->mnt_tmpfreevnodelistsize++; 3235 vp->v_iflag |= VI_FREE; 3236 vp->v_mflag |= VMP_TMPMNTFREELIST; 3237 VI_UNLOCK(vp); 3238 if (mp->mnt_tmpfreevnodelistsize >= mnt_free_list_batch) 3239 vnlru_return_batch_locked(mp); 3240 mtx_unlock(&mp->mnt_listmtx); 3241 } else { 3242 VI_UNLOCK(vp); 3243 counter_u64_add(free_owe_inact, 1); 3244 } 3245 } 3246 3247 void 3248 vdrop(struct vnode *vp) 3249 { 3250 3251 ASSERT_VI_UNLOCKED(vp, __func__); 3252 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3253 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3254 return; 3255 VI_LOCK(vp); 3256 vdropl(vp); 3257 } 3258 3259 void 3260 vdropl(struct vnode *vp) 3261 { 3262 3263 ASSERT_VI_LOCKED(vp, __func__); 3264 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3265 if (!refcount_release(&vp->v_holdcnt)) { 3266 VI_UNLOCK(vp); 3267 return; 3268 } 3269 if (VN_IS_DOOMED(vp)) { 3270 freevnode(vp); 3271 return; 3272 } 3273 vdrop_deactivate(vp); 3274 } 3275 3276 /* 3277 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3278 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3279 * OWEINACT tracks whether a vnode missed a call to inactive due to a 3280 * failed lock upgrade. 3281 */ 3282 void 3283 vinactive(struct vnode *vp) 3284 { 3285 struct vm_object *obj; 3286 3287 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3288 ASSERT_VI_LOCKED(vp, "vinactive"); 3289 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3290 ("vinactive: recursed on VI_DOINGINACT")); 3291 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3292 vp->v_iflag |= VI_DOINGINACT; 3293 vp->v_iflag &= ~VI_OWEINACT; 3294 VI_UNLOCK(vp); 3295 /* 3296 * Before moving off the active list, we must be sure that any 3297 * modified pages are converted into the vnode's dirty 3298 * buffers, since these will no longer be checked once the 3299 * vnode is on the inactive list. 3300 * 3301 * The write-out of the dirty pages is asynchronous. At the 3302 * point that VOP_INACTIVE() is called, there could still be 3303 * pending I/O and dirty pages in the object. 3304 */ 3305 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3306 vm_object_mightbedirty(obj)) { 3307 VM_OBJECT_WLOCK(obj); 3308 vm_object_page_clean(obj, 0, 0, 0); 3309 VM_OBJECT_WUNLOCK(obj); 3310 } 3311 VOP_INACTIVE(vp, curthread); 3312 VI_LOCK(vp); 3313 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3314 ("vinactive: lost VI_DOINGINACT")); 3315 vp->v_iflag &= ~VI_DOINGINACT; 3316 } 3317 3318 /* 3319 * Remove any vnodes in the vnode table belonging to mount point mp. 3320 * 3321 * If FORCECLOSE is not specified, there should not be any active ones, 3322 * return error if any are found (nb: this is a user error, not a 3323 * system error). If FORCECLOSE is specified, detach any active vnodes 3324 * that are found. 3325 * 3326 * If WRITECLOSE is set, only flush out regular file vnodes open for 3327 * writing. 3328 * 3329 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3330 * 3331 * `rootrefs' specifies the base reference count for the root vnode 3332 * of this filesystem. The root vnode is considered busy if its 3333 * v_usecount exceeds this value. On a successful return, vflush(, td) 3334 * will call vrele() on the root vnode exactly rootrefs times. 3335 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3336 * be zero. 3337 */ 3338 #ifdef DIAGNOSTIC 3339 static int busyprt = 0; /* print out busy vnodes */ 3340 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3341 #endif 3342 3343 int 3344 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3345 { 3346 struct vnode *vp, *mvp, *rootvp = NULL; 3347 struct vattr vattr; 3348 int busy = 0, error; 3349 3350 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3351 rootrefs, flags); 3352 if (rootrefs > 0) { 3353 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3354 ("vflush: bad args")); 3355 /* 3356 * Get the filesystem root vnode. We can vput() it 3357 * immediately, since with rootrefs > 0, it won't go away. 3358 */ 3359 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3360 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3361 __func__, error); 3362 return (error); 3363 } 3364 vput(rootvp); 3365 } 3366 loop: 3367 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3368 vholdl(vp); 3369 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3370 if (error) { 3371 vdrop(vp); 3372 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3373 goto loop; 3374 } 3375 /* 3376 * Skip over a vnodes marked VV_SYSTEM. 3377 */ 3378 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3379 VOP_UNLOCK(vp); 3380 vdrop(vp); 3381 continue; 3382 } 3383 /* 3384 * If WRITECLOSE is set, flush out unlinked but still open 3385 * files (even if open only for reading) and regular file 3386 * vnodes open for writing. 3387 */ 3388 if (flags & WRITECLOSE) { 3389 if (vp->v_object != NULL) { 3390 VM_OBJECT_WLOCK(vp->v_object); 3391 vm_object_page_clean(vp->v_object, 0, 0, 0); 3392 VM_OBJECT_WUNLOCK(vp->v_object); 3393 } 3394 error = VOP_FSYNC(vp, MNT_WAIT, td); 3395 if (error != 0) { 3396 VOP_UNLOCK(vp); 3397 vdrop(vp); 3398 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3399 return (error); 3400 } 3401 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3402 VI_LOCK(vp); 3403 3404 if ((vp->v_type == VNON || 3405 (error == 0 && vattr.va_nlink > 0)) && 3406 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3407 VOP_UNLOCK(vp); 3408 vdropl(vp); 3409 continue; 3410 } 3411 } else 3412 VI_LOCK(vp); 3413 /* 3414 * With v_usecount == 0, all we need to do is clear out the 3415 * vnode data structures and we are done. 3416 * 3417 * If FORCECLOSE is set, forcibly close the vnode. 3418 */ 3419 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3420 vgonel(vp); 3421 } else { 3422 busy++; 3423 #ifdef DIAGNOSTIC 3424 if (busyprt) 3425 vn_printf(vp, "vflush: busy vnode "); 3426 #endif 3427 } 3428 VOP_UNLOCK(vp); 3429 vdropl(vp); 3430 } 3431 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3432 /* 3433 * If just the root vnode is busy, and if its refcount 3434 * is equal to `rootrefs', then go ahead and kill it. 3435 */ 3436 VI_LOCK(rootvp); 3437 KASSERT(busy > 0, ("vflush: not busy")); 3438 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3439 ("vflush: usecount %d < rootrefs %d", 3440 rootvp->v_usecount, rootrefs)); 3441 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3442 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3443 vgone(rootvp); 3444 VOP_UNLOCK(rootvp); 3445 busy = 0; 3446 } else 3447 VI_UNLOCK(rootvp); 3448 } 3449 if (busy) { 3450 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3451 busy); 3452 return (EBUSY); 3453 } 3454 for (; rootrefs > 0; rootrefs--) 3455 vrele(rootvp); 3456 return (0); 3457 } 3458 3459 /* 3460 * Recycle an unused vnode to the front of the free list. 3461 */ 3462 int 3463 vrecycle(struct vnode *vp) 3464 { 3465 int recycled; 3466 3467 VI_LOCK(vp); 3468 recycled = vrecyclel(vp); 3469 VI_UNLOCK(vp); 3470 return (recycled); 3471 } 3472 3473 /* 3474 * vrecycle, with the vp interlock held. 3475 */ 3476 int 3477 vrecyclel(struct vnode *vp) 3478 { 3479 int recycled; 3480 3481 ASSERT_VOP_ELOCKED(vp, __func__); 3482 ASSERT_VI_LOCKED(vp, __func__); 3483 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3484 recycled = 0; 3485 if (vp->v_usecount == 0) { 3486 recycled = 1; 3487 vgonel(vp); 3488 } 3489 return (recycled); 3490 } 3491 3492 /* 3493 * Eliminate all activity associated with a vnode 3494 * in preparation for reuse. 3495 */ 3496 void 3497 vgone(struct vnode *vp) 3498 { 3499 VI_LOCK(vp); 3500 vgonel(vp); 3501 VI_UNLOCK(vp); 3502 } 3503 3504 static void 3505 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3506 struct vnode *lowervp __unused) 3507 { 3508 } 3509 3510 /* 3511 * Notify upper mounts about reclaimed or unlinked vnode. 3512 */ 3513 void 3514 vfs_notify_upper(struct vnode *vp, int event) 3515 { 3516 static struct vfsops vgonel_vfsops = { 3517 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3518 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3519 }; 3520 struct mount *mp, *ump, *mmp; 3521 3522 mp = vp->v_mount; 3523 if (mp == NULL) 3524 return; 3525 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3526 return; 3527 3528 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3529 mmp->mnt_op = &vgonel_vfsops; 3530 mmp->mnt_kern_flag |= MNTK_MARKER; 3531 MNT_ILOCK(mp); 3532 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3533 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3534 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3535 ump = TAILQ_NEXT(ump, mnt_upper_link); 3536 continue; 3537 } 3538 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3539 MNT_IUNLOCK(mp); 3540 switch (event) { 3541 case VFS_NOTIFY_UPPER_RECLAIM: 3542 VFS_RECLAIM_LOWERVP(ump, vp); 3543 break; 3544 case VFS_NOTIFY_UPPER_UNLINK: 3545 VFS_UNLINK_LOWERVP(ump, vp); 3546 break; 3547 default: 3548 KASSERT(0, ("invalid event %d", event)); 3549 break; 3550 } 3551 MNT_ILOCK(mp); 3552 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3553 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3554 } 3555 free(mmp, M_TEMP); 3556 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3557 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3558 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3559 wakeup(&mp->mnt_uppers); 3560 } 3561 MNT_IUNLOCK(mp); 3562 } 3563 3564 /* 3565 * vgone, with the vp interlock held. 3566 */ 3567 static void 3568 vgonel(struct vnode *vp) 3569 { 3570 struct thread *td; 3571 struct mount *mp; 3572 vm_object_t object; 3573 bool active, oweinact; 3574 3575 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3576 ASSERT_VI_LOCKED(vp, "vgonel"); 3577 VNASSERT(vp->v_holdcnt, vp, 3578 ("vgonel: vp %p has no reference.", vp)); 3579 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3580 td = curthread; 3581 3582 /* 3583 * Don't vgonel if we're already doomed. 3584 */ 3585 if (vp->v_irflag & VIRF_DOOMED) 3586 return; 3587 vp->v_irflag |= VIRF_DOOMED; 3588 3589 /* 3590 * Check to see if the vnode is in use. If so, we have to call 3591 * VOP_CLOSE() and VOP_INACTIVE(). 3592 */ 3593 active = vp->v_usecount > 0; 3594 oweinact = (vp->v_iflag & VI_OWEINACT) != 0; 3595 VI_UNLOCK(vp); 3596 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3597 3598 /* 3599 * If purging an active vnode, it must be closed and 3600 * deactivated before being reclaimed. 3601 */ 3602 if (active) 3603 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3604 if (oweinact || active) { 3605 VI_LOCK(vp); 3606 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3607 vinactive(vp); 3608 VI_UNLOCK(vp); 3609 } 3610 if (vp->v_type == VSOCK) 3611 vfs_unp_reclaim(vp); 3612 3613 /* 3614 * Clean out any buffers associated with the vnode. 3615 * If the flush fails, just toss the buffers. 3616 */ 3617 mp = NULL; 3618 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3619 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3620 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3621 while (vinvalbuf(vp, 0, 0, 0) != 0) 3622 ; 3623 } 3624 3625 BO_LOCK(&vp->v_bufobj); 3626 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3627 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3628 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3629 vp->v_bufobj.bo_clean.bv_cnt == 0, 3630 ("vp %p bufobj not invalidated", vp)); 3631 3632 /* 3633 * For VMIO bufobj, BO_DEAD is set later, or in 3634 * vm_object_terminate() after the object's page queue is 3635 * flushed. 3636 */ 3637 object = vp->v_bufobj.bo_object; 3638 if (object == NULL) 3639 vp->v_bufobj.bo_flag |= BO_DEAD; 3640 BO_UNLOCK(&vp->v_bufobj); 3641 3642 /* 3643 * Handle the VM part. Tmpfs handles v_object on its own (the 3644 * OBJT_VNODE check). Nullfs or other bypassing filesystems 3645 * should not touch the object borrowed from the lower vnode 3646 * (the handle check). 3647 */ 3648 if (object != NULL && object->type == OBJT_VNODE && 3649 object->handle == vp) 3650 vnode_destroy_vobject(vp); 3651 3652 /* 3653 * Reclaim the vnode. 3654 */ 3655 if (VOP_RECLAIM(vp, td)) 3656 panic("vgone: cannot reclaim"); 3657 if (mp != NULL) 3658 vn_finished_secondary_write(mp); 3659 VNASSERT(vp->v_object == NULL, vp, 3660 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3661 /* 3662 * Clear the advisory locks and wake up waiting threads. 3663 */ 3664 (void)VOP_ADVLOCKPURGE(vp); 3665 vp->v_lockf = NULL; 3666 /* 3667 * Delete from old mount point vnode list. 3668 */ 3669 delmntque(vp); 3670 cache_purge(vp); 3671 /* 3672 * Done with purge, reset to the standard lock and invalidate 3673 * the vnode. 3674 */ 3675 VI_LOCK(vp); 3676 vp->v_vnlock = &vp->v_lock; 3677 vp->v_op = &dead_vnodeops; 3678 vp->v_tag = "none"; 3679 vp->v_type = VBAD; 3680 } 3681 3682 /* 3683 * Calculate the total number of references to a special device. 3684 */ 3685 int 3686 vcount(struct vnode *vp) 3687 { 3688 int count; 3689 3690 dev_lock(); 3691 count = vp->v_rdev->si_usecount; 3692 dev_unlock(); 3693 return (count); 3694 } 3695 3696 /* 3697 * Print out a description of a vnode. 3698 */ 3699 static char *typename[] = 3700 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3701 "VMARKER"}; 3702 3703 void 3704 vn_printf(struct vnode *vp, const char *fmt, ...) 3705 { 3706 va_list ap; 3707 char buf[256], buf2[16]; 3708 u_long flags; 3709 3710 va_start(ap, fmt); 3711 vprintf(fmt, ap); 3712 va_end(ap); 3713 printf("%p: ", (void *)vp); 3714 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3715 printf(" usecount %d, writecount %d, refcount %d", 3716 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 3717 switch (vp->v_type) { 3718 case VDIR: 3719 printf(" mountedhere %p\n", vp->v_mountedhere); 3720 break; 3721 case VCHR: 3722 printf(" rdev %p\n", vp->v_rdev); 3723 break; 3724 case VSOCK: 3725 printf(" socket %p\n", vp->v_unpcb); 3726 break; 3727 case VFIFO: 3728 printf(" fifoinfo %p\n", vp->v_fifoinfo); 3729 break; 3730 default: 3731 printf("\n"); 3732 break; 3733 } 3734 buf[0] = '\0'; 3735 buf[1] = '\0'; 3736 if (vp->v_irflag & VIRF_DOOMED) 3737 strlcat(buf, "|VIRF_DOOMED", sizeof(buf)); 3738 flags = vp->v_irflag & ~(VIRF_DOOMED); 3739 if (flags != 0) { 3740 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags); 3741 strlcat(buf, buf2, sizeof(buf)); 3742 } 3743 if (vp->v_vflag & VV_ROOT) 3744 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3745 if (vp->v_vflag & VV_ISTTY) 3746 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3747 if (vp->v_vflag & VV_NOSYNC) 3748 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3749 if (vp->v_vflag & VV_ETERNALDEV) 3750 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3751 if (vp->v_vflag & VV_CACHEDLABEL) 3752 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3753 if (vp->v_vflag & VV_VMSIZEVNLOCK) 3754 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf)); 3755 if (vp->v_vflag & VV_COPYONWRITE) 3756 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3757 if (vp->v_vflag & VV_SYSTEM) 3758 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3759 if (vp->v_vflag & VV_PROCDEP) 3760 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3761 if (vp->v_vflag & VV_NOKNOTE) 3762 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3763 if (vp->v_vflag & VV_DELETED) 3764 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3765 if (vp->v_vflag & VV_MD) 3766 strlcat(buf, "|VV_MD", sizeof(buf)); 3767 if (vp->v_vflag & VV_FORCEINSMQ) 3768 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3769 if (vp->v_vflag & VV_READLINK) 3770 strlcat(buf, "|VV_READLINK", sizeof(buf)); 3771 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3772 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3773 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3774 if (flags != 0) { 3775 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3776 strlcat(buf, buf2, sizeof(buf)); 3777 } 3778 if (vp->v_iflag & VI_TEXT_REF) 3779 strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); 3780 if (vp->v_iflag & VI_MOUNT) 3781 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3782 if (vp->v_iflag & VI_FREE) 3783 strlcat(buf, "|VI_FREE", sizeof(buf)); 3784 if (vp->v_iflag & VI_ACTIVE) 3785 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3786 if (vp->v_iflag & VI_DOINGINACT) 3787 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3788 if (vp->v_iflag & VI_OWEINACT) 3789 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3790 flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_FREE | VI_ACTIVE | 3791 VI_DOINGINACT | VI_OWEINACT); 3792 if (flags != 0) { 3793 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3794 strlcat(buf, buf2, sizeof(buf)); 3795 } 3796 if (vp->v_mflag & VMP_TMPMNTFREELIST) 3797 strlcat(buf, "|VMP_TMPMNTFREELIST", sizeof(buf)); 3798 flags = vp->v_mflag & ~(VMP_TMPMNTFREELIST); 3799 if (flags != 0) { 3800 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags); 3801 strlcat(buf, buf2, sizeof(buf)); 3802 } 3803 printf(" flags (%s)\n", buf + 1); 3804 if (mtx_owned(VI_MTX(vp))) 3805 printf(" VI_LOCKed"); 3806 if (vp->v_object != NULL) 3807 printf(" v_object %p ref %d pages %d " 3808 "cleanbuf %d dirtybuf %d\n", 3809 vp->v_object, vp->v_object->ref_count, 3810 vp->v_object->resident_page_count, 3811 vp->v_bufobj.bo_clean.bv_cnt, 3812 vp->v_bufobj.bo_dirty.bv_cnt); 3813 printf(" "); 3814 lockmgr_printinfo(vp->v_vnlock); 3815 if (vp->v_data != NULL) 3816 VOP_PRINT(vp); 3817 } 3818 3819 #ifdef DDB 3820 /* 3821 * List all of the locked vnodes in the system. 3822 * Called when debugging the kernel. 3823 */ 3824 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3825 { 3826 struct mount *mp; 3827 struct vnode *vp; 3828 3829 /* 3830 * Note: because this is DDB, we can't obey the locking semantics 3831 * for these structures, which means we could catch an inconsistent 3832 * state and dereference a nasty pointer. Not much to be done 3833 * about that. 3834 */ 3835 db_printf("Locked vnodes\n"); 3836 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3837 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3838 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3839 vn_printf(vp, "vnode "); 3840 } 3841 } 3842 } 3843 3844 /* 3845 * Show details about the given vnode. 3846 */ 3847 DB_SHOW_COMMAND(vnode, db_show_vnode) 3848 { 3849 struct vnode *vp; 3850 3851 if (!have_addr) 3852 return; 3853 vp = (struct vnode *)addr; 3854 vn_printf(vp, "vnode "); 3855 } 3856 3857 /* 3858 * Show details about the given mount point. 3859 */ 3860 DB_SHOW_COMMAND(mount, db_show_mount) 3861 { 3862 struct mount *mp; 3863 struct vfsopt *opt; 3864 struct statfs *sp; 3865 struct vnode *vp; 3866 char buf[512]; 3867 uint64_t mflags; 3868 u_int flags; 3869 3870 if (!have_addr) { 3871 /* No address given, print short info about all mount points. */ 3872 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3873 db_printf("%p %s on %s (%s)\n", mp, 3874 mp->mnt_stat.f_mntfromname, 3875 mp->mnt_stat.f_mntonname, 3876 mp->mnt_stat.f_fstypename); 3877 if (db_pager_quit) 3878 break; 3879 } 3880 db_printf("\nMore info: show mount <addr>\n"); 3881 return; 3882 } 3883 3884 mp = (struct mount *)addr; 3885 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3886 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3887 3888 buf[0] = '\0'; 3889 mflags = mp->mnt_flag; 3890 #define MNT_FLAG(flag) do { \ 3891 if (mflags & (flag)) { \ 3892 if (buf[0] != '\0') \ 3893 strlcat(buf, ", ", sizeof(buf)); \ 3894 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3895 mflags &= ~(flag); \ 3896 } \ 3897 } while (0) 3898 MNT_FLAG(MNT_RDONLY); 3899 MNT_FLAG(MNT_SYNCHRONOUS); 3900 MNT_FLAG(MNT_NOEXEC); 3901 MNT_FLAG(MNT_NOSUID); 3902 MNT_FLAG(MNT_NFS4ACLS); 3903 MNT_FLAG(MNT_UNION); 3904 MNT_FLAG(MNT_ASYNC); 3905 MNT_FLAG(MNT_SUIDDIR); 3906 MNT_FLAG(MNT_SOFTDEP); 3907 MNT_FLAG(MNT_NOSYMFOLLOW); 3908 MNT_FLAG(MNT_GJOURNAL); 3909 MNT_FLAG(MNT_MULTILABEL); 3910 MNT_FLAG(MNT_ACLS); 3911 MNT_FLAG(MNT_NOATIME); 3912 MNT_FLAG(MNT_NOCLUSTERR); 3913 MNT_FLAG(MNT_NOCLUSTERW); 3914 MNT_FLAG(MNT_SUJ); 3915 MNT_FLAG(MNT_EXRDONLY); 3916 MNT_FLAG(MNT_EXPORTED); 3917 MNT_FLAG(MNT_DEFEXPORTED); 3918 MNT_FLAG(MNT_EXPORTANON); 3919 MNT_FLAG(MNT_EXKERB); 3920 MNT_FLAG(MNT_EXPUBLIC); 3921 MNT_FLAG(MNT_LOCAL); 3922 MNT_FLAG(MNT_QUOTA); 3923 MNT_FLAG(MNT_ROOTFS); 3924 MNT_FLAG(MNT_USER); 3925 MNT_FLAG(MNT_IGNORE); 3926 MNT_FLAG(MNT_UPDATE); 3927 MNT_FLAG(MNT_DELEXPORT); 3928 MNT_FLAG(MNT_RELOAD); 3929 MNT_FLAG(MNT_FORCE); 3930 MNT_FLAG(MNT_SNAPSHOT); 3931 MNT_FLAG(MNT_BYFSID); 3932 #undef MNT_FLAG 3933 if (mflags != 0) { 3934 if (buf[0] != '\0') 3935 strlcat(buf, ", ", sizeof(buf)); 3936 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3937 "0x%016jx", mflags); 3938 } 3939 db_printf(" mnt_flag = %s\n", buf); 3940 3941 buf[0] = '\0'; 3942 flags = mp->mnt_kern_flag; 3943 #define MNT_KERN_FLAG(flag) do { \ 3944 if (flags & (flag)) { \ 3945 if (buf[0] != '\0') \ 3946 strlcat(buf, ", ", sizeof(buf)); \ 3947 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3948 flags &= ~(flag); \ 3949 } \ 3950 } while (0) 3951 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3952 MNT_KERN_FLAG(MNTK_ASYNC); 3953 MNT_KERN_FLAG(MNTK_SOFTDEP); 3954 MNT_KERN_FLAG(MNTK_DRAINING); 3955 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3956 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3957 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3958 MNT_KERN_FLAG(MNTK_NO_IOPF); 3959 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3960 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3961 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3962 MNT_KERN_FLAG(MNTK_MARKER); 3963 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3964 MNT_KERN_FLAG(MNTK_NOASYNC); 3965 MNT_KERN_FLAG(MNTK_UNMOUNT); 3966 MNT_KERN_FLAG(MNTK_MWAIT); 3967 MNT_KERN_FLAG(MNTK_SUSPEND); 3968 MNT_KERN_FLAG(MNTK_SUSPEND2); 3969 MNT_KERN_FLAG(MNTK_SUSPENDED); 3970 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3971 MNT_KERN_FLAG(MNTK_NOKNOTE); 3972 #undef MNT_KERN_FLAG 3973 if (flags != 0) { 3974 if (buf[0] != '\0') 3975 strlcat(buf, ", ", sizeof(buf)); 3976 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3977 "0x%08x", flags); 3978 } 3979 db_printf(" mnt_kern_flag = %s\n", buf); 3980 3981 db_printf(" mnt_opt = "); 3982 opt = TAILQ_FIRST(mp->mnt_opt); 3983 if (opt != NULL) { 3984 db_printf("%s", opt->name); 3985 opt = TAILQ_NEXT(opt, link); 3986 while (opt != NULL) { 3987 db_printf(", %s", opt->name); 3988 opt = TAILQ_NEXT(opt, link); 3989 } 3990 } 3991 db_printf("\n"); 3992 3993 sp = &mp->mnt_stat; 3994 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3995 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3996 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3997 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3998 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3999 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 4000 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 4001 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 4002 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 4003 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 4004 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 4005 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 4006 4007 db_printf(" mnt_cred = { uid=%u ruid=%u", 4008 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 4009 if (jailed(mp->mnt_cred)) 4010 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 4011 db_printf(" }\n"); 4012 db_printf(" mnt_ref = %d (with %d in the struct)\n", 4013 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref); 4014 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 4015 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 4016 db_printf(" mnt_activevnodelistsize = %d\n", 4017 mp->mnt_activevnodelistsize); 4018 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n", 4019 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount); 4020 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 4021 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 4022 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 4023 db_printf(" mnt_lockref = %d (with %d in the struct)\n", 4024 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref); 4025 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 4026 db_printf(" mnt_secondary_accwrites = %d\n", 4027 mp->mnt_secondary_accwrites); 4028 db_printf(" mnt_gjprovider = %s\n", 4029 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 4030 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops); 4031 4032 db_printf("\n\nList of active vnodes\n"); 4033 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 4034 if (vp->v_type != VMARKER) { 4035 vn_printf(vp, "vnode "); 4036 if (db_pager_quit) 4037 break; 4038 } 4039 } 4040 db_printf("\n\nList of inactive vnodes\n"); 4041 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4042 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 4043 vn_printf(vp, "vnode "); 4044 if (db_pager_quit) 4045 break; 4046 } 4047 } 4048 } 4049 #endif /* DDB */ 4050 4051 /* 4052 * Fill in a struct xvfsconf based on a struct vfsconf. 4053 */ 4054 static int 4055 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 4056 { 4057 struct xvfsconf xvfsp; 4058 4059 bzero(&xvfsp, sizeof(xvfsp)); 4060 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4061 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4062 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4063 xvfsp.vfc_flags = vfsp->vfc_flags; 4064 /* 4065 * These are unused in userland, we keep them 4066 * to not break binary compatibility. 4067 */ 4068 xvfsp.vfc_vfsops = NULL; 4069 xvfsp.vfc_next = NULL; 4070 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4071 } 4072 4073 #ifdef COMPAT_FREEBSD32 4074 struct xvfsconf32 { 4075 uint32_t vfc_vfsops; 4076 char vfc_name[MFSNAMELEN]; 4077 int32_t vfc_typenum; 4078 int32_t vfc_refcount; 4079 int32_t vfc_flags; 4080 uint32_t vfc_next; 4081 }; 4082 4083 static int 4084 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 4085 { 4086 struct xvfsconf32 xvfsp; 4087 4088 bzero(&xvfsp, sizeof(xvfsp)); 4089 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 4090 xvfsp.vfc_typenum = vfsp->vfc_typenum; 4091 xvfsp.vfc_refcount = vfsp->vfc_refcount; 4092 xvfsp.vfc_flags = vfsp->vfc_flags; 4093 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 4094 } 4095 #endif 4096 4097 /* 4098 * Top level filesystem related information gathering. 4099 */ 4100 static int 4101 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 4102 { 4103 struct vfsconf *vfsp; 4104 int error; 4105 4106 error = 0; 4107 vfsconf_slock(); 4108 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4109 #ifdef COMPAT_FREEBSD32 4110 if (req->flags & SCTL_MASK32) 4111 error = vfsconf2x32(req, vfsp); 4112 else 4113 #endif 4114 error = vfsconf2x(req, vfsp); 4115 if (error) 4116 break; 4117 } 4118 vfsconf_sunlock(); 4119 return (error); 4120 } 4121 4122 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 4123 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 4124 "S,xvfsconf", "List of all configured filesystems"); 4125 4126 #ifndef BURN_BRIDGES 4127 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 4128 4129 static int 4130 vfs_sysctl(SYSCTL_HANDLER_ARGS) 4131 { 4132 int *name = (int *)arg1 - 1; /* XXX */ 4133 u_int namelen = arg2 + 1; /* XXX */ 4134 struct vfsconf *vfsp; 4135 4136 log(LOG_WARNING, "userland calling deprecated sysctl, " 4137 "please rebuild world\n"); 4138 4139 #if 1 || defined(COMPAT_PRELITE2) 4140 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4141 if (namelen == 1) 4142 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4143 #endif 4144 4145 switch (name[1]) { 4146 case VFS_MAXTYPENUM: 4147 if (namelen != 2) 4148 return (ENOTDIR); 4149 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4150 case VFS_CONF: 4151 if (namelen != 3) 4152 return (ENOTDIR); /* overloaded */ 4153 vfsconf_slock(); 4154 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4155 if (vfsp->vfc_typenum == name[2]) 4156 break; 4157 } 4158 vfsconf_sunlock(); 4159 if (vfsp == NULL) 4160 return (EOPNOTSUPP); 4161 #ifdef COMPAT_FREEBSD32 4162 if (req->flags & SCTL_MASK32) 4163 return (vfsconf2x32(req, vfsp)); 4164 else 4165 #endif 4166 return (vfsconf2x(req, vfsp)); 4167 } 4168 return (EOPNOTSUPP); 4169 } 4170 4171 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4172 CTLFLAG_MPSAFE, vfs_sysctl, 4173 "Generic filesystem"); 4174 4175 #if 1 || defined(COMPAT_PRELITE2) 4176 4177 static int 4178 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4179 { 4180 int error; 4181 struct vfsconf *vfsp; 4182 struct ovfsconf ovfs; 4183 4184 vfsconf_slock(); 4185 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4186 bzero(&ovfs, sizeof(ovfs)); 4187 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4188 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4189 ovfs.vfc_index = vfsp->vfc_typenum; 4190 ovfs.vfc_refcount = vfsp->vfc_refcount; 4191 ovfs.vfc_flags = vfsp->vfc_flags; 4192 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4193 if (error != 0) { 4194 vfsconf_sunlock(); 4195 return (error); 4196 } 4197 } 4198 vfsconf_sunlock(); 4199 return (0); 4200 } 4201 4202 #endif /* 1 || COMPAT_PRELITE2 */ 4203 #endif /* !BURN_BRIDGES */ 4204 4205 #define KINFO_VNODESLOP 10 4206 #ifdef notyet 4207 /* 4208 * Dump vnode list (via sysctl). 4209 */ 4210 /* ARGSUSED */ 4211 static int 4212 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4213 { 4214 struct xvnode *xvn; 4215 struct mount *mp; 4216 struct vnode *vp; 4217 int error, len, n; 4218 4219 /* 4220 * Stale numvnodes access is not fatal here. 4221 */ 4222 req->lock = 0; 4223 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4224 if (!req->oldptr) 4225 /* Make an estimate */ 4226 return (SYSCTL_OUT(req, 0, len)); 4227 4228 error = sysctl_wire_old_buffer(req, 0); 4229 if (error != 0) 4230 return (error); 4231 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4232 n = 0; 4233 mtx_lock(&mountlist_mtx); 4234 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4235 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4236 continue; 4237 MNT_ILOCK(mp); 4238 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4239 if (n == len) 4240 break; 4241 vref(vp); 4242 xvn[n].xv_size = sizeof *xvn; 4243 xvn[n].xv_vnode = vp; 4244 xvn[n].xv_id = 0; /* XXX compat */ 4245 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4246 XV_COPY(usecount); 4247 XV_COPY(writecount); 4248 XV_COPY(holdcnt); 4249 XV_COPY(mount); 4250 XV_COPY(numoutput); 4251 XV_COPY(type); 4252 #undef XV_COPY 4253 xvn[n].xv_flag = vp->v_vflag; 4254 4255 switch (vp->v_type) { 4256 case VREG: 4257 case VDIR: 4258 case VLNK: 4259 break; 4260 case VBLK: 4261 case VCHR: 4262 if (vp->v_rdev == NULL) { 4263 vrele(vp); 4264 continue; 4265 } 4266 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4267 break; 4268 case VSOCK: 4269 xvn[n].xv_socket = vp->v_socket; 4270 break; 4271 case VFIFO: 4272 xvn[n].xv_fifo = vp->v_fifoinfo; 4273 break; 4274 case VNON: 4275 case VBAD: 4276 default: 4277 /* shouldn't happen? */ 4278 vrele(vp); 4279 continue; 4280 } 4281 vrele(vp); 4282 ++n; 4283 } 4284 MNT_IUNLOCK(mp); 4285 mtx_lock(&mountlist_mtx); 4286 vfs_unbusy(mp); 4287 if (n == len) 4288 break; 4289 } 4290 mtx_unlock(&mountlist_mtx); 4291 4292 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4293 free(xvn, M_TEMP); 4294 return (error); 4295 } 4296 4297 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4298 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4299 ""); 4300 #endif 4301 4302 static void 4303 unmount_or_warn(struct mount *mp) 4304 { 4305 int error; 4306 4307 error = dounmount(mp, MNT_FORCE, curthread); 4308 if (error != 0) { 4309 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4310 if (error == EBUSY) 4311 printf("BUSY)\n"); 4312 else 4313 printf("%d)\n", error); 4314 } 4315 } 4316 4317 /* 4318 * Unmount all filesystems. The list is traversed in reverse order 4319 * of mounting to avoid dependencies. 4320 */ 4321 void 4322 vfs_unmountall(void) 4323 { 4324 struct mount *mp, *tmp; 4325 4326 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4327 4328 /* 4329 * Since this only runs when rebooting, it is not interlocked. 4330 */ 4331 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4332 vfs_ref(mp); 4333 4334 /* 4335 * Forcibly unmounting "/dev" before "/" would prevent clean 4336 * unmount of the latter. 4337 */ 4338 if (mp == rootdevmp) 4339 continue; 4340 4341 unmount_or_warn(mp); 4342 } 4343 4344 if (rootdevmp != NULL) 4345 unmount_or_warn(rootdevmp); 4346 } 4347 4348 /* 4349 * perform msync on all vnodes under a mount point 4350 * the mount point must be locked. 4351 */ 4352 void 4353 vfs_msync(struct mount *mp, int flags) 4354 { 4355 struct vnode *vp, *mvp; 4356 struct vm_object *obj; 4357 4358 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4359 4360 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) 4361 return; 4362 4363 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 4364 obj = vp->v_object; 4365 if (obj != NULL && vm_object_mightbedirty(obj) && 4366 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 4367 if (!vget(vp, 4368 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 4369 curthread)) { 4370 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 4371 vput(vp); 4372 continue; 4373 } 4374 4375 obj = vp->v_object; 4376 if (obj != NULL) { 4377 VM_OBJECT_WLOCK(obj); 4378 vm_object_page_clean(obj, 0, 0, 4379 flags == MNT_WAIT ? 4380 OBJPC_SYNC : OBJPC_NOSYNC); 4381 VM_OBJECT_WUNLOCK(obj); 4382 } 4383 vput(vp); 4384 } 4385 } else 4386 VI_UNLOCK(vp); 4387 } 4388 } 4389 4390 static void 4391 destroy_vpollinfo_free(struct vpollinfo *vi) 4392 { 4393 4394 knlist_destroy(&vi->vpi_selinfo.si_note); 4395 mtx_destroy(&vi->vpi_lock); 4396 uma_zfree(vnodepoll_zone, vi); 4397 } 4398 4399 static void 4400 destroy_vpollinfo(struct vpollinfo *vi) 4401 { 4402 4403 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4404 seldrain(&vi->vpi_selinfo); 4405 destroy_vpollinfo_free(vi); 4406 } 4407 4408 /* 4409 * Initialize per-vnode helper structure to hold poll-related state. 4410 */ 4411 void 4412 v_addpollinfo(struct vnode *vp) 4413 { 4414 struct vpollinfo *vi; 4415 4416 if (vp->v_pollinfo != NULL) 4417 return; 4418 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4419 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4420 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4421 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4422 VI_LOCK(vp); 4423 if (vp->v_pollinfo != NULL) { 4424 VI_UNLOCK(vp); 4425 destroy_vpollinfo_free(vi); 4426 return; 4427 } 4428 vp->v_pollinfo = vi; 4429 VI_UNLOCK(vp); 4430 } 4431 4432 /* 4433 * Record a process's interest in events which might happen to 4434 * a vnode. Because poll uses the historic select-style interface 4435 * internally, this routine serves as both the ``check for any 4436 * pending events'' and the ``record my interest in future events'' 4437 * functions. (These are done together, while the lock is held, 4438 * to avoid race conditions.) 4439 */ 4440 int 4441 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4442 { 4443 4444 v_addpollinfo(vp); 4445 mtx_lock(&vp->v_pollinfo->vpi_lock); 4446 if (vp->v_pollinfo->vpi_revents & events) { 4447 /* 4448 * This leaves events we are not interested 4449 * in available for the other process which 4450 * which presumably had requested them 4451 * (otherwise they would never have been 4452 * recorded). 4453 */ 4454 events &= vp->v_pollinfo->vpi_revents; 4455 vp->v_pollinfo->vpi_revents &= ~events; 4456 4457 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4458 return (events); 4459 } 4460 vp->v_pollinfo->vpi_events |= events; 4461 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4462 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4463 return (0); 4464 } 4465 4466 /* 4467 * Routine to create and manage a filesystem syncer vnode. 4468 */ 4469 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4470 static int sync_fsync(struct vop_fsync_args *); 4471 static int sync_inactive(struct vop_inactive_args *); 4472 static int sync_reclaim(struct vop_reclaim_args *); 4473 4474 static struct vop_vector sync_vnodeops = { 4475 .vop_bypass = VOP_EOPNOTSUPP, 4476 .vop_close = sync_close, /* close */ 4477 .vop_fsync = sync_fsync, /* fsync */ 4478 .vop_inactive = sync_inactive, /* inactive */ 4479 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */ 4480 .vop_reclaim = sync_reclaim, /* reclaim */ 4481 .vop_lock1 = vop_stdlock, /* lock */ 4482 .vop_unlock = vop_stdunlock, /* unlock */ 4483 .vop_islocked = vop_stdislocked, /* islocked */ 4484 }; 4485 VFS_VOP_VECTOR_REGISTER(sync_vnodeops); 4486 4487 /* 4488 * Create a new filesystem syncer vnode for the specified mount point. 4489 */ 4490 void 4491 vfs_allocate_syncvnode(struct mount *mp) 4492 { 4493 struct vnode *vp; 4494 struct bufobj *bo; 4495 static long start, incr, next; 4496 int error; 4497 4498 /* Allocate a new vnode */ 4499 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4500 if (error != 0) 4501 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4502 vp->v_type = VNON; 4503 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4504 vp->v_vflag |= VV_FORCEINSMQ; 4505 error = insmntque(vp, mp); 4506 if (error != 0) 4507 panic("vfs_allocate_syncvnode: insmntque() failed"); 4508 vp->v_vflag &= ~VV_FORCEINSMQ; 4509 VOP_UNLOCK(vp); 4510 /* 4511 * Place the vnode onto the syncer worklist. We attempt to 4512 * scatter them about on the list so that they will go off 4513 * at evenly distributed times even if all the filesystems 4514 * are mounted at once. 4515 */ 4516 next += incr; 4517 if (next == 0 || next > syncer_maxdelay) { 4518 start /= 2; 4519 incr /= 2; 4520 if (start == 0) { 4521 start = syncer_maxdelay / 2; 4522 incr = syncer_maxdelay; 4523 } 4524 next = start; 4525 } 4526 bo = &vp->v_bufobj; 4527 BO_LOCK(bo); 4528 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4529 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4530 mtx_lock(&sync_mtx); 4531 sync_vnode_count++; 4532 if (mp->mnt_syncer == NULL) { 4533 mp->mnt_syncer = vp; 4534 vp = NULL; 4535 } 4536 mtx_unlock(&sync_mtx); 4537 BO_UNLOCK(bo); 4538 if (vp != NULL) { 4539 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4540 vgone(vp); 4541 vput(vp); 4542 } 4543 } 4544 4545 void 4546 vfs_deallocate_syncvnode(struct mount *mp) 4547 { 4548 struct vnode *vp; 4549 4550 mtx_lock(&sync_mtx); 4551 vp = mp->mnt_syncer; 4552 if (vp != NULL) 4553 mp->mnt_syncer = NULL; 4554 mtx_unlock(&sync_mtx); 4555 if (vp != NULL) 4556 vrele(vp); 4557 } 4558 4559 /* 4560 * Do a lazy sync of the filesystem. 4561 */ 4562 static int 4563 sync_fsync(struct vop_fsync_args *ap) 4564 { 4565 struct vnode *syncvp = ap->a_vp; 4566 struct mount *mp = syncvp->v_mount; 4567 int error, save; 4568 struct bufobj *bo; 4569 4570 /* 4571 * We only need to do something if this is a lazy evaluation. 4572 */ 4573 if (ap->a_waitfor != MNT_LAZY) 4574 return (0); 4575 4576 /* 4577 * Move ourselves to the back of the sync list. 4578 */ 4579 bo = &syncvp->v_bufobj; 4580 BO_LOCK(bo); 4581 vn_syncer_add_to_worklist(bo, syncdelay); 4582 BO_UNLOCK(bo); 4583 4584 /* 4585 * Walk the list of vnodes pushing all that are dirty and 4586 * not already on the sync list. 4587 */ 4588 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4589 return (0); 4590 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4591 vfs_unbusy(mp); 4592 return (0); 4593 } 4594 save = curthread_pflags_set(TDP_SYNCIO); 4595 /* 4596 * The filesystem at hand may be idle with free vnodes stored in the 4597 * batch. Return them instead of letting them stay there indefinitely. 4598 */ 4599 vnlru_return_batch(mp); 4600 vfs_msync(mp, MNT_NOWAIT); 4601 error = VFS_SYNC(mp, MNT_LAZY); 4602 curthread_pflags_restore(save); 4603 vn_finished_write(mp); 4604 vfs_unbusy(mp); 4605 return (error); 4606 } 4607 4608 /* 4609 * The syncer vnode is no referenced. 4610 */ 4611 static int 4612 sync_inactive(struct vop_inactive_args *ap) 4613 { 4614 4615 vgone(ap->a_vp); 4616 return (0); 4617 } 4618 4619 /* 4620 * The syncer vnode is no longer needed and is being decommissioned. 4621 * 4622 * Modifications to the worklist must be protected by sync_mtx. 4623 */ 4624 static int 4625 sync_reclaim(struct vop_reclaim_args *ap) 4626 { 4627 struct vnode *vp = ap->a_vp; 4628 struct bufobj *bo; 4629 4630 bo = &vp->v_bufobj; 4631 BO_LOCK(bo); 4632 mtx_lock(&sync_mtx); 4633 if (vp->v_mount->mnt_syncer == vp) 4634 vp->v_mount->mnt_syncer = NULL; 4635 if (bo->bo_flag & BO_ONWORKLST) { 4636 LIST_REMOVE(bo, bo_synclist); 4637 syncer_worklist_len--; 4638 sync_vnode_count--; 4639 bo->bo_flag &= ~BO_ONWORKLST; 4640 } 4641 mtx_unlock(&sync_mtx); 4642 BO_UNLOCK(bo); 4643 4644 return (0); 4645 } 4646 4647 int 4648 vn_need_pageq_flush(struct vnode *vp) 4649 { 4650 struct vm_object *obj; 4651 int need; 4652 4653 MPASS(mtx_owned(VI_MTX(vp))); 4654 need = 0; 4655 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 4656 vm_object_mightbedirty(obj)) 4657 need = 1; 4658 return (need); 4659 } 4660 4661 /* 4662 * Check if vnode represents a disk device 4663 */ 4664 int 4665 vn_isdisk(struct vnode *vp, int *errp) 4666 { 4667 int error; 4668 4669 if (vp->v_type != VCHR) { 4670 error = ENOTBLK; 4671 goto out; 4672 } 4673 error = 0; 4674 dev_lock(); 4675 if (vp->v_rdev == NULL) 4676 error = ENXIO; 4677 else if (vp->v_rdev->si_devsw == NULL) 4678 error = ENXIO; 4679 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4680 error = ENOTBLK; 4681 dev_unlock(); 4682 out: 4683 if (errp != NULL) 4684 *errp = error; 4685 return (error == 0); 4686 } 4687 4688 /* 4689 * Common filesystem object access control check routine. Accepts a 4690 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4691 * and optional call-by-reference privused argument allowing vaccess() 4692 * to indicate to the caller whether privilege was used to satisfy the 4693 * request (obsoleted). Returns 0 on success, or an errno on failure. 4694 */ 4695 int 4696 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4697 accmode_t accmode, struct ucred *cred, int *privused) 4698 { 4699 accmode_t dac_granted; 4700 accmode_t priv_granted; 4701 4702 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4703 ("invalid bit in accmode")); 4704 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4705 ("VAPPEND without VWRITE")); 4706 4707 /* 4708 * Look for a normal, non-privileged way to access the file/directory 4709 * as requested. If it exists, go with that. 4710 */ 4711 4712 if (privused != NULL) 4713 *privused = 0; 4714 4715 dac_granted = 0; 4716 4717 /* Check the owner. */ 4718 if (cred->cr_uid == file_uid) { 4719 dac_granted |= VADMIN; 4720 if (file_mode & S_IXUSR) 4721 dac_granted |= VEXEC; 4722 if (file_mode & S_IRUSR) 4723 dac_granted |= VREAD; 4724 if (file_mode & S_IWUSR) 4725 dac_granted |= (VWRITE | VAPPEND); 4726 4727 if ((accmode & dac_granted) == accmode) 4728 return (0); 4729 4730 goto privcheck; 4731 } 4732 4733 /* Otherwise, check the groups (first match) */ 4734 if (groupmember(file_gid, cred)) { 4735 if (file_mode & S_IXGRP) 4736 dac_granted |= VEXEC; 4737 if (file_mode & S_IRGRP) 4738 dac_granted |= VREAD; 4739 if (file_mode & S_IWGRP) 4740 dac_granted |= (VWRITE | VAPPEND); 4741 4742 if ((accmode & dac_granted) == accmode) 4743 return (0); 4744 4745 goto privcheck; 4746 } 4747 4748 /* Otherwise, check everyone else. */ 4749 if (file_mode & S_IXOTH) 4750 dac_granted |= VEXEC; 4751 if (file_mode & S_IROTH) 4752 dac_granted |= VREAD; 4753 if (file_mode & S_IWOTH) 4754 dac_granted |= (VWRITE | VAPPEND); 4755 if ((accmode & dac_granted) == accmode) 4756 return (0); 4757 4758 privcheck: 4759 /* 4760 * Build a privilege mask to determine if the set of privileges 4761 * satisfies the requirements when combined with the granted mask 4762 * from above. For each privilege, if the privilege is required, 4763 * bitwise or the request type onto the priv_granted mask. 4764 */ 4765 priv_granted = 0; 4766 4767 if (type == VDIR) { 4768 /* 4769 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4770 * requests, instead of PRIV_VFS_EXEC. 4771 */ 4772 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4773 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 4774 priv_granted |= VEXEC; 4775 } else { 4776 /* 4777 * Ensure that at least one execute bit is on. Otherwise, 4778 * a privileged user will always succeed, and we don't want 4779 * this to happen unless the file really is executable. 4780 */ 4781 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4782 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4783 !priv_check_cred(cred, PRIV_VFS_EXEC)) 4784 priv_granted |= VEXEC; 4785 } 4786 4787 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4788 !priv_check_cred(cred, PRIV_VFS_READ)) 4789 priv_granted |= VREAD; 4790 4791 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4792 !priv_check_cred(cred, PRIV_VFS_WRITE)) 4793 priv_granted |= (VWRITE | VAPPEND); 4794 4795 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4796 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 4797 priv_granted |= VADMIN; 4798 4799 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4800 /* XXX audit: privilege used */ 4801 if (privused != NULL) 4802 *privused = 1; 4803 return (0); 4804 } 4805 4806 return ((accmode & VADMIN) ? EPERM : EACCES); 4807 } 4808 4809 /* 4810 * Credential check based on process requesting service, and per-attribute 4811 * permissions. 4812 */ 4813 int 4814 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4815 struct thread *td, accmode_t accmode) 4816 { 4817 4818 /* 4819 * Kernel-invoked always succeeds. 4820 */ 4821 if (cred == NOCRED) 4822 return (0); 4823 4824 /* 4825 * Do not allow privileged processes in jail to directly manipulate 4826 * system attributes. 4827 */ 4828 switch (attrnamespace) { 4829 case EXTATTR_NAMESPACE_SYSTEM: 4830 /* Potentially should be: return (EPERM); */ 4831 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 4832 case EXTATTR_NAMESPACE_USER: 4833 return (VOP_ACCESS(vp, accmode, cred, td)); 4834 default: 4835 return (EPERM); 4836 } 4837 } 4838 4839 #ifdef DEBUG_VFS_LOCKS 4840 /* 4841 * This only exists to suppress warnings from unlocked specfs accesses. It is 4842 * no longer ok to have an unlocked VFS. 4843 */ 4844 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4845 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4846 4847 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4848 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4849 "Drop into debugger on lock violation"); 4850 4851 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4852 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4853 0, "Check for interlock across VOPs"); 4854 4855 int vfs_badlock_print = 1; /* Print lock violations. */ 4856 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4857 0, "Print lock violations"); 4858 4859 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 4860 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 4861 0, "Print vnode details on lock violations"); 4862 4863 #ifdef KDB 4864 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4865 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4866 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4867 #endif 4868 4869 static void 4870 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4871 { 4872 4873 #ifdef KDB 4874 if (vfs_badlock_backtrace) 4875 kdb_backtrace(); 4876 #endif 4877 if (vfs_badlock_vnode) 4878 vn_printf(vp, "vnode "); 4879 if (vfs_badlock_print) 4880 printf("%s: %p %s\n", str, (void *)vp, msg); 4881 if (vfs_badlock_ddb) 4882 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4883 } 4884 4885 void 4886 assert_vi_locked(struct vnode *vp, const char *str) 4887 { 4888 4889 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4890 vfs_badlock("interlock is not locked but should be", str, vp); 4891 } 4892 4893 void 4894 assert_vi_unlocked(struct vnode *vp, const char *str) 4895 { 4896 4897 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4898 vfs_badlock("interlock is locked but should not be", str, vp); 4899 } 4900 4901 void 4902 assert_vop_locked(struct vnode *vp, const char *str) 4903 { 4904 int locked; 4905 4906 if (!IGNORE_LOCK(vp)) { 4907 locked = VOP_ISLOCKED(vp); 4908 if (locked == 0 || locked == LK_EXCLOTHER) 4909 vfs_badlock("is not locked but should be", str, vp); 4910 } 4911 } 4912 4913 void 4914 assert_vop_unlocked(struct vnode *vp, const char *str) 4915 { 4916 4917 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4918 vfs_badlock("is locked but should not be", str, vp); 4919 } 4920 4921 void 4922 assert_vop_elocked(struct vnode *vp, const char *str) 4923 { 4924 4925 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4926 vfs_badlock("is not exclusive locked but should be", str, vp); 4927 } 4928 #endif /* DEBUG_VFS_LOCKS */ 4929 4930 void 4931 vop_rename_fail(struct vop_rename_args *ap) 4932 { 4933 4934 if (ap->a_tvp != NULL) 4935 vput(ap->a_tvp); 4936 if (ap->a_tdvp == ap->a_tvp) 4937 vrele(ap->a_tdvp); 4938 else 4939 vput(ap->a_tdvp); 4940 vrele(ap->a_fdvp); 4941 vrele(ap->a_fvp); 4942 } 4943 4944 void 4945 vop_rename_pre(void *ap) 4946 { 4947 struct vop_rename_args *a = ap; 4948 4949 #ifdef DEBUG_VFS_LOCKS 4950 if (a->a_tvp) 4951 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4952 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4953 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4954 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4955 4956 /* Check the source (from). */ 4957 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4958 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4959 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4960 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4961 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4962 4963 /* Check the target. */ 4964 if (a->a_tvp) 4965 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4966 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4967 #endif 4968 if (a->a_tdvp != a->a_fdvp) 4969 vhold(a->a_fdvp); 4970 if (a->a_tvp != a->a_fvp) 4971 vhold(a->a_fvp); 4972 vhold(a->a_tdvp); 4973 if (a->a_tvp) 4974 vhold(a->a_tvp); 4975 } 4976 4977 #ifdef DEBUG_VFS_LOCKS 4978 void 4979 vop_strategy_pre(void *ap) 4980 { 4981 struct vop_strategy_args *a; 4982 struct buf *bp; 4983 4984 a = ap; 4985 bp = a->a_bp; 4986 4987 /* 4988 * Cluster ops lock their component buffers but not the IO container. 4989 */ 4990 if ((bp->b_flags & B_CLUSTER) != 0) 4991 return; 4992 4993 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4994 if (vfs_badlock_print) 4995 printf( 4996 "VOP_STRATEGY: bp is not locked but should be\n"); 4997 if (vfs_badlock_ddb) 4998 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4999 } 5000 } 5001 5002 void 5003 vop_lock_pre(void *ap) 5004 { 5005 struct vop_lock1_args *a = ap; 5006 5007 if ((a->a_flags & LK_INTERLOCK) == 0) 5008 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5009 else 5010 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 5011 } 5012 5013 void 5014 vop_lock_post(void *ap, int rc) 5015 { 5016 struct vop_lock1_args *a = ap; 5017 5018 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 5019 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 5020 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 5021 } 5022 5023 void 5024 vop_unlock_pre(void *ap) 5025 { 5026 struct vop_unlock_args *a = ap; 5027 5028 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 5029 } 5030 5031 void 5032 vop_unlock_post(void *ap, int rc) 5033 { 5034 return; 5035 } 5036 5037 void 5038 vop_need_inactive_pre(void *ap) 5039 { 5040 struct vop_need_inactive_args *a = ap; 5041 5042 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5043 } 5044 5045 void 5046 vop_need_inactive_post(void *ap, int rc) 5047 { 5048 struct vop_need_inactive_args *a = ap; 5049 5050 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE"); 5051 } 5052 #endif 5053 5054 void 5055 vop_create_post(void *ap, int rc) 5056 { 5057 struct vop_create_args *a = ap; 5058 5059 if (!rc) 5060 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5061 } 5062 5063 void 5064 vop_deleteextattr_post(void *ap, int rc) 5065 { 5066 struct vop_deleteextattr_args *a = ap; 5067 5068 if (!rc) 5069 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5070 } 5071 5072 void 5073 vop_link_post(void *ap, int rc) 5074 { 5075 struct vop_link_args *a = ap; 5076 5077 if (!rc) { 5078 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 5079 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 5080 } 5081 } 5082 5083 void 5084 vop_mkdir_post(void *ap, int rc) 5085 { 5086 struct vop_mkdir_args *a = ap; 5087 5088 if (!rc) 5089 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5090 } 5091 5092 void 5093 vop_mknod_post(void *ap, int rc) 5094 { 5095 struct vop_mknod_args *a = ap; 5096 5097 if (!rc) 5098 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5099 } 5100 5101 void 5102 vop_reclaim_post(void *ap, int rc) 5103 { 5104 struct vop_reclaim_args *a = ap; 5105 5106 if (!rc) 5107 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 5108 } 5109 5110 void 5111 vop_remove_post(void *ap, int rc) 5112 { 5113 struct vop_remove_args *a = ap; 5114 5115 if (!rc) { 5116 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5117 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5118 } 5119 } 5120 5121 void 5122 vop_rename_post(void *ap, int rc) 5123 { 5124 struct vop_rename_args *a = ap; 5125 long hint; 5126 5127 if (!rc) { 5128 hint = NOTE_WRITE; 5129 if (a->a_fdvp == a->a_tdvp) { 5130 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 5131 hint |= NOTE_LINK; 5132 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5133 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5134 } else { 5135 hint |= NOTE_EXTEND; 5136 if (a->a_fvp->v_type == VDIR) 5137 hint |= NOTE_LINK; 5138 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 5139 5140 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 5141 a->a_tvp->v_type == VDIR) 5142 hint &= ~NOTE_LINK; 5143 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 5144 } 5145 5146 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 5147 if (a->a_tvp) 5148 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 5149 } 5150 if (a->a_tdvp != a->a_fdvp) 5151 vdrop(a->a_fdvp); 5152 if (a->a_tvp != a->a_fvp) 5153 vdrop(a->a_fvp); 5154 vdrop(a->a_tdvp); 5155 if (a->a_tvp) 5156 vdrop(a->a_tvp); 5157 } 5158 5159 void 5160 vop_rmdir_post(void *ap, int rc) 5161 { 5162 struct vop_rmdir_args *a = ap; 5163 5164 if (!rc) { 5165 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5166 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5167 } 5168 } 5169 5170 void 5171 vop_setattr_post(void *ap, int rc) 5172 { 5173 struct vop_setattr_args *a = ap; 5174 5175 if (!rc) 5176 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5177 } 5178 5179 void 5180 vop_setextattr_post(void *ap, int rc) 5181 { 5182 struct vop_setextattr_args *a = ap; 5183 5184 if (!rc) 5185 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5186 } 5187 5188 void 5189 vop_symlink_post(void *ap, int rc) 5190 { 5191 struct vop_symlink_args *a = ap; 5192 5193 if (!rc) 5194 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5195 } 5196 5197 void 5198 vop_open_post(void *ap, int rc) 5199 { 5200 struct vop_open_args *a = ap; 5201 5202 if (!rc) 5203 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5204 } 5205 5206 void 5207 vop_close_post(void *ap, int rc) 5208 { 5209 struct vop_close_args *a = ap; 5210 5211 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5212 !VN_IS_DOOMED(a->a_vp))) { 5213 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5214 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5215 } 5216 } 5217 5218 void 5219 vop_read_post(void *ap, int rc) 5220 { 5221 struct vop_read_args *a = ap; 5222 5223 if (!rc) 5224 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5225 } 5226 5227 void 5228 vop_readdir_post(void *ap, int rc) 5229 { 5230 struct vop_readdir_args *a = ap; 5231 5232 if (!rc) 5233 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5234 } 5235 5236 static struct knlist fs_knlist; 5237 5238 static void 5239 vfs_event_init(void *arg) 5240 { 5241 knlist_init_mtx(&fs_knlist, NULL); 5242 } 5243 /* XXX - correct order? */ 5244 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5245 5246 void 5247 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5248 { 5249 5250 KNOTE_UNLOCKED(&fs_knlist, event); 5251 } 5252 5253 static int filt_fsattach(struct knote *kn); 5254 static void filt_fsdetach(struct knote *kn); 5255 static int filt_fsevent(struct knote *kn, long hint); 5256 5257 struct filterops fs_filtops = { 5258 .f_isfd = 0, 5259 .f_attach = filt_fsattach, 5260 .f_detach = filt_fsdetach, 5261 .f_event = filt_fsevent 5262 }; 5263 5264 static int 5265 filt_fsattach(struct knote *kn) 5266 { 5267 5268 kn->kn_flags |= EV_CLEAR; 5269 knlist_add(&fs_knlist, kn, 0); 5270 return (0); 5271 } 5272 5273 static void 5274 filt_fsdetach(struct knote *kn) 5275 { 5276 5277 knlist_remove(&fs_knlist, kn, 0); 5278 } 5279 5280 static int 5281 filt_fsevent(struct knote *kn, long hint) 5282 { 5283 5284 kn->kn_fflags |= hint; 5285 return (kn->kn_fflags != 0); 5286 } 5287 5288 static int 5289 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5290 { 5291 struct vfsidctl vc; 5292 int error; 5293 struct mount *mp; 5294 5295 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5296 if (error) 5297 return (error); 5298 if (vc.vc_vers != VFS_CTL_VERS1) 5299 return (EINVAL); 5300 mp = vfs_getvfs(&vc.vc_fsid); 5301 if (mp == NULL) 5302 return (ENOENT); 5303 /* ensure that a specific sysctl goes to the right filesystem. */ 5304 if (strcmp(vc.vc_fstypename, "*") != 0 && 5305 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5306 vfs_rel(mp); 5307 return (EINVAL); 5308 } 5309 VCTLTOREQ(&vc, req); 5310 error = VFS_SYSCTL(mp, vc.vc_op, req); 5311 vfs_rel(mp); 5312 return (error); 5313 } 5314 5315 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 5316 NULL, 0, sysctl_vfs_ctl, "", 5317 "Sysctl by fsid"); 5318 5319 /* 5320 * Function to initialize a va_filerev field sensibly. 5321 * XXX: Wouldn't a random number make a lot more sense ?? 5322 */ 5323 u_quad_t 5324 init_va_filerev(void) 5325 { 5326 struct bintime bt; 5327 5328 getbinuptime(&bt); 5329 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5330 } 5331 5332 static int filt_vfsread(struct knote *kn, long hint); 5333 static int filt_vfswrite(struct knote *kn, long hint); 5334 static int filt_vfsvnode(struct knote *kn, long hint); 5335 static void filt_vfsdetach(struct knote *kn); 5336 static struct filterops vfsread_filtops = { 5337 .f_isfd = 1, 5338 .f_detach = filt_vfsdetach, 5339 .f_event = filt_vfsread 5340 }; 5341 static struct filterops vfswrite_filtops = { 5342 .f_isfd = 1, 5343 .f_detach = filt_vfsdetach, 5344 .f_event = filt_vfswrite 5345 }; 5346 static struct filterops vfsvnode_filtops = { 5347 .f_isfd = 1, 5348 .f_detach = filt_vfsdetach, 5349 .f_event = filt_vfsvnode 5350 }; 5351 5352 static void 5353 vfs_knllock(void *arg) 5354 { 5355 struct vnode *vp = arg; 5356 5357 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5358 } 5359 5360 static void 5361 vfs_knlunlock(void *arg) 5362 { 5363 struct vnode *vp = arg; 5364 5365 VOP_UNLOCK(vp); 5366 } 5367 5368 static void 5369 vfs_knl_assert_locked(void *arg) 5370 { 5371 #ifdef DEBUG_VFS_LOCKS 5372 struct vnode *vp = arg; 5373 5374 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5375 #endif 5376 } 5377 5378 static void 5379 vfs_knl_assert_unlocked(void *arg) 5380 { 5381 #ifdef DEBUG_VFS_LOCKS 5382 struct vnode *vp = arg; 5383 5384 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5385 #endif 5386 } 5387 5388 int 5389 vfs_kqfilter(struct vop_kqfilter_args *ap) 5390 { 5391 struct vnode *vp = ap->a_vp; 5392 struct knote *kn = ap->a_kn; 5393 struct knlist *knl; 5394 5395 switch (kn->kn_filter) { 5396 case EVFILT_READ: 5397 kn->kn_fop = &vfsread_filtops; 5398 break; 5399 case EVFILT_WRITE: 5400 kn->kn_fop = &vfswrite_filtops; 5401 break; 5402 case EVFILT_VNODE: 5403 kn->kn_fop = &vfsvnode_filtops; 5404 break; 5405 default: 5406 return (EINVAL); 5407 } 5408 5409 kn->kn_hook = (caddr_t)vp; 5410 5411 v_addpollinfo(vp); 5412 if (vp->v_pollinfo == NULL) 5413 return (ENOMEM); 5414 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5415 vhold(vp); 5416 knlist_add(knl, kn, 0); 5417 5418 return (0); 5419 } 5420 5421 /* 5422 * Detach knote from vnode 5423 */ 5424 static void 5425 filt_vfsdetach(struct knote *kn) 5426 { 5427 struct vnode *vp = (struct vnode *)kn->kn_hook; 5428 5429 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5430 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5431 vdrop(vp); 5432 } 5433 5434 /*ARGSUSED*/ 5435 static int 5436 filt_vfsread(struct knote *kn, long hint) 5437 { 5438 struct vnode *vp = (struct vnode *)kn->kn_hook; 5439 struct vattr va; 5440 int res; 5441 5442 /* 5443 * filesystem is gone, so set the EOF flag and schedule 5444 * the knote for deletion. 5445 */ 5446 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5447 VI_LOCK(vp); 5448 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5449 VI_UNLOCK(vp); 5450 return (1); 5451 } 5452 5453 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5454 return (0); 5455 5456 VI_LOCK(vp); 5457 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5458 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5459 VI_UNLOCK(vp); 5460 return (res); 5461 } 5462 5463 /*ARGSUSED*/ 5464 static int 5465 filt_vfswrite(struct knote *kn, long hint) 5466 { 5467 struct vnode *vp = (struct vnode *)kn->kn_hook; 5468 5469 VI_LOCK(vp); 5470 5471 /* 5472 * filesystem is gone, so set the EOF flag and schedule 5473 * the knote for deletion. 5474 */ 5475 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5476 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5477 5478 kn->kn_data = 0; 5479 VI_UNLOCK(vp); 5480 return (1); 5481 } 5482 5483 static int 5484 filt_vfsvnode(struct knote *kn, long hint) 5485 { 5486 struct vnode *vp = (struct vnode *)kn->kn_hook; 5487 int res; 5488 5489 VI_LOCK(vp); 5490 if (kn->kn_sfflags & hint) 5491 kn->kn_fflags |= hint; 5492 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5493 kn->kn_flags |= EV_EOF; 5494 VI_UNLOCK(vp); 5495 return (1); 5496 } 5497 res = (kn->kn_fflags != 0); 5498 VI_UNLOCK(vp); 5499 return (res); 5500 } 5501 5502 /* 5503 * Returns whether the directory is empty or not. 5504 * If it is empty, the return value is 0; otherwise 5505 * the return value is an error value (which may 5506 * be ENOTEMPTY). 5507 */ 5508 int 5509 vfs_emptydir(struct vnode *vp) 5510 { 5511 struct uio uio; 5512 struct iovec iov; 5513 struct dirent *dirent, *dp, *endp; 5514 int error, eof; 5515 5516 error = 0; 5517 eof = 0; 5518 5519 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 5520 5521 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); 5522 iov.iov_base = dirent; 5523 iov.iov_len = sizeof(struct dirent); 5524 5525 uio.uio_iov = &iov; 5526 uio.uio_iovcnt = 1; 5527 uio.uio_offset = 0; 5528 uio.uio_resid = sizeof(struct dirent); 5529 uio.uio_segflg = UIO_SYSSPACE; 5530 uio.uio_rw = UIO_READ; 5531 uio.uio_td = curthread; 5532 5533 while (eof == 0 && error == 0) { 5534 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof, 5535 NULL, NULL); 5536 if (error != 0) 5537 break; 5538 endp = (void *)((uint8_t *)dirent + 5539 sizeof(struct dirent) - uio.uio_resid); 5540 for (dp = dirent; dp < endp; 5541 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) { 5542 if (dp->d_type == DT_WHT) 5543 continue; 5544 if (dp->d_namlen == 0) 5545 continue; 5546 if (dp->d_type != DT_DIR && 5547 dp->d_type != DT_UNKNOWN) { 5548 error = ENOTEMPTY; 5549 break; 5550 } 5551 if (dp->d_namlen > 2) { 5552 error = ENOTEMPTY; 5553 break; 5554 } 5555 if (dp->d_namlen == 1 && 5556 dp->d_name[0] != '.') { 5557 error = ENOTEMPTY; 5558 break; 5559 } 5560 if (dp->d_namlen == 2 && 5561 dp->d_name[1] != '.') { 5562 error = ENOTEMPTY; 5563 break; 5564 } 5565 uio.uio_resid = sizeof(struct dirent); 5566 } 5567 } 5568 free(dirent, M_TEMP); 5569 return (error); 5570 } 5571 5572 int 5573 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5574 { 5575 int error; 5576 5577 if (dp->d_reclen > ap->a_uio->uio_resid) 5578 return (ENAMETOOLONG); 5579 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5580 if (error) { 5581 if (ap->a_ncookies != NULL) { 5582 if (ap->a_cookies != NULL) 5583 free(ap->a_cookies, M_TEMP); 5584 ap->a_cookies = NULL; 5585 *ap->a_ncookies = 0; 5586 } 5587 return (error); 5588 } 5589 if (ap->a_ncookies == NULL) 5590 return (0); 5591 5592 KASSERT(ap->a_cookies, 5593 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5594 5595 *ap->a_cookies = realloc(*ap->a_cookies, 5596 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5597 (*ap->a_cookies)[*ap->a_ncookies] = off; 5598 *ap->a_ncookies += 1; 5599 return (0); 5600 } 5601 5602 /* 5603 * Mark for update the access time of the file if the filesystem 5604 * supports VOP_MARKATIME. This functionality is used by execve and 5605 * mmap, so we want to avoid the I/O implied by directly setting 5606 * va_atime for the sake of efficiency. 5607 */ 5608 void 5609 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5610 { 5611 struct mount *mp; 5612 5613 mp = vp->v_mount; 5614 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5615 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5616 (void)VOP_MARKATIME(vp); 5617 } 5618 5619 /* 5620 * The purpose of this routine is to remove granularity from accmode_t, 5621 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5622 * VADMIN and VAPPEND. 5623 * 5624 * If it returns 0, the caller is supposed to continue with the usual 5625 * access checks using 'accmode' as modified by this routine. If it 5626 * returns nonzero value, the caller is supposed to return that value 5627 * as errno. 5628 * 5629 * Note that after this routine runs, accmode may be zero. 5630 */ 5631 int 5632 vfs_unixify_accmode(accmode_t *accmode) 5633 { 5634 /* 5635 * There is no way to specify explicit "deny" rule using 5636 * file mode or POSIX.1e ACLs. 5637 */ 5638 if (*accmode & VEXPLICIT_DENY) { 5639 *accmode = 0; 5640 return (0); 5641 } 5642 5643 /* 5644 * None of these can be translated into usual access bits. 5645 * Also, the common case for NFSv4 ACLs is to not contain 5646 * either of these bits. Caller should check for VWRITE 5647 * on the containing directory instead. 5648 */ 5649 if (*accmode & (VDELETE_CHILD | VDELETE)) 5650 return (EPERM); 5651 5652 if (*accmode & VADMIN_PERMS) { 5653 *accmode &= ~VADMIN_PERMS; 5654 *accmode |= VADMIN; 5655 } 5656 5657 /* 5658 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 5659 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 5660 */ 5661 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 5662 5663 return (0); 5664 } 5665 5666 /* 5667 * Clear out a doomed vnode (if any) and replace it with a new one as long 5668 * as the fs is not being unmounted. Return the root vnode to the caller. 5669 */ 5670 static int __noinline 5671 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp) 5672 { 5673 struct vnode *vp; 5674 int error; 5675 5676 restart: 5677 if (mp->mnt_rootvnode != NULL) { 5678 MNT_ILOCK(mp); 5679 vp = mp->mnt_rootvnode; 5680 if (vp != NULL) { 5681 if (!VN_IS_DOOMED(vp)) { 5682 vrefact(vp); 5683 MNT_IUNLOCK(mp); 5684 error = vn_lock(vp, flags); 5685 if (error == 0) { 5686 *vpp = vp; 5687 return (0); 5688 } 5689 vrele(vp); 5690 goto restart; 5691 } 5692 /* 5693 * Clear the old one. 5694 */ 5695 mp->mnt_rootvnode = NULL; 5696 } 5697 MNT_IUNLOCK(mp); 5698 if (vp != NULL) { 5699 /* 5700 * Paired with a fence in vfs_op_thread_exit(). 5701 */ 5702 atomic_thread_fence_acq(); 5703 vfs_op_barrier_wait(mp); 5704 vrele(vp); 5705 } 5706 } 5707 error = VFS_CACHEDROOT(mp, flags, vpp); 5708 if (error != 0) 5709 return (error); 5710 if (mp->mnt_vfs_ops == 0) { 5711 MNT_ILOCK(mp); 5712 if (mp->mnt_vfs_ops != 0) { 5713 MNT_IUNLOCK(mp); 5714 return (0); 5715 } 5716 if (mp->mnt_rootvnode == NULL) { 5717 vrefact(*vpp); 5718 mp->mnt_rootvnode = *vpp; 5719 } else { 5720 if (mp->mnt_rootvnode != *vpp) { 5721 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) { 5722 panic("%s: mismatch between vnode returned " 5723 " by VFS_CACHEDROOT and the one cached " 5724 " (%p != %p)", 5725 __func__, *vpp, mp->mnt_rootvnode); 5726 } 5727 } 5728 } 5729 MNT_IUNLOCK(mp); 5730 } 5731 return (0); 5732 } 5733 5734 int 5735 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp) 5736 { 5737 struct vnode *vp; 5738 int error; 5739 5740 if (!vfs_op_thread_enter(mp)) 5741 return (vfs_cache_root_fallback(mp, flags, vpp)); 5742 vp = (struct vnode *)atomic_load_ptr(&mp->mnt_rootvnode); 5743 if (vp == NULL || VN_IS_DOOMED(vp)) { 5744 vfs_op_thread_exit(mp); 5745 return (vfs_cache_root_fallback(mp, flags, vpp)); 5746 } 5747 vrefact(vp); 5748 vfs_op_thread_exit(mp); 5749 error = vn_lock(vp, flags); 5750 if (error != 0) { 5751 vrele(vp); 5752 return (vfs_cache_root_fallback(mp, flags, vpp)); 5753 } 5754 *vpp = vp; 5755 return (0); 5756 } 5757 5758 struct vnode * 5759 vfs_cache_root_clear(struct mount *mp) 5760 { 5761 struct vnode *vp; 5762 5763 /* 5764 * ops > 0 guarantees there is nobody who can see this vnode 5765 */ 5766 MPASS(mp->mnt_vfs_ops > 0); 5767 vp = mp->mnt_rootvnode; 5768 mp->mnt_rootvnode = NULL; 5769 return (vp); 5770 } 5771 5772 void 5773 vfs_cache_root_set(struct mount *mp, struct vnode *vp) 5774 { 5775 5776 MPASS(mp->mnt_vfs_ops > 0); 5777 vrefact(vp); 5778 mp->mnt_rootvnode = vp; 5779 } 5780 5781 /* 5782 * These are helper functions for filesystems to traverse all 5783 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 5784 * 5785 * This interface replaces MNT_VNODE_FOREACH. 5786 */ 5787 5788 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 5789 5790 struct vnode * 5791 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5792 { 5793 struct vnode *vp; 5794 5795 if (should_yield()) 5796 kern_yield(PRI_USER); 5797 MNT_ILOCK(mp); 5798 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5799 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 5800 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 5801 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 5802 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 5803 continue; 5804 VI_LOCK(vp); 5805 if (VN_IS_DOOMED(vp)) { 5806 VI_UNLOCK(vp); 5807 continue; 5808 } 5809 break; 5810 } 5811 if (vp == NULL) { 5812 __mnt_vnode_markerfree_all(mvp, mp); 5813 /* MNT_IUNLOCK(mp); -- done in above function */ 5814 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5815 return (NULL); 5816 } 5817 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5818 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5819 MNT_IUNLOCK(mp); 5820 return (vp); 5821 } 5822 5823 struct vnode * 5824 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5825 { 5826 struct vnode *vp; 5827 5828 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5829 MNT_ILOCK(mp); 5830 MNT_REF(mp); 5831 (*mvp)->v_mount = mp; 5832 (*mvp)->v_type = VMARKER; 5833 5834 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 5835 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */ 5836 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp)) 5837 continue; 5838 VI_LOCK(vp); 5839 if (VN_IS_DOOMED(vp)) { 5840 VI_UNLOCK(vp); 5841 continue; 5842 } 5843 break; 5844 } 5845 if (vp == NULL) { 5846 MNT_REL(mp); 5847 MNT_IUNLOCK(mp); 5848 free(*mvp, M_VNODE_MARKER); 5849 *mvp = NULL; 5850 return (NULL); 5851 } 5852 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5853 MNT_IUNLOCK(mp); 5854 return (vp); 5855 } 5856 5857 void 5858 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5859 { 5860 5861 if (*mvp == NULL) { 5862 MNT_IUNLOCK(mp); 5863 return; 5864 } 5865 5866 mtx_assert(MNT_MTX(mp), MA_OWNED); 5867 5868 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5869 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5870 MNT_REL(mp); 5871 MNT_IUNLOCK(mp); 5872 free(*mvp, M_VNODE_MARKER); 5873 *mvp = NULL; 5874 } 5875 5876 /* 5877 * These are helper functions for filesystems to traverse their 5878 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5879 */ 5880 static void 5881 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5882 { 5883 5884 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5885 5886 MNT_ILOCK(mp); 5887 MNT_REL(mp); 5888 MNT_IUNLOCK(mp); 5889 free(*mvp, M_VNODE_MARKER); 5890 *mvp = NULL; 5891 } 5892 5893 /* 5894 * Relock the mp mount vnode list lock with the vp vnode interlock in the 5895 * conventional lock order during mnt_vnode_next_active iteration. 5896 * 5897 * On entry, the mount vnode list lock is held and the vnode interlock is not. 5898 * The list lock is dropped and reacquired. On success, both locks are held. 5899 * On failure, the mount vnode list lock is held but the vnode interlock is 5900 * not, and the procedure may have yielded. 5901 */ 5902 static bool 5903 mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp, 5904 struct vnode *vp) 5905 { 5906 const struct vnode *tmp; 5907 bool held, ret; 5908 5909 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 5910 TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp, 5911 ("%s: bad marker", __func__)); 5912 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 5913 ("%s: inappropriate vnode", __func__)); 5914 ASSERT_VI_UNLOCKED(vp, __func__); 5915 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5916 5917 ret = false; 5918 5919 TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist); 5920 TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist); 5921 5922 /* 5923 * Use a hold to prevent vp from disappearing while the mount vnode 5924 * list lock is dropped and reacquired. Normally a hold would be 5925 * acquired with vhold(), but that might try to acquire the vnode 5926 * interlock, which would be a LOR with the mount vnode list lock. 5927 */ 5928 held = refcount_acquire_if_not_zero(&vp->v_holdcnt); 5929 mtx_unlock(&mp->mnt_listmtx); 5930 if (!held) 5931 goto abort; 5932 VI_LOCK(vp); 5933 if (!refcount_release_if_not_last(&vp->v_holdcnt)) { 5934 vdropl(vp); 5935 goto abort; 5936 } 5937 mtx_lock(&mp->mnt_listmtx); 5938 5939 /* 5940 * Determine whether the vnode is still the next one after the marker, 5941 * excepting any other markers. If the vnode has not been doomed by 5942 * vgone() then the hold should have ensured that it remained on the 5943 * active list. If it has been doomed but is still on the active list, 5944 * don't abort, but rather skip over it (avoid spinning on doomed 5945 * vnodes). 5946 */ 5947 tmp = mvp; 5948 do { 5949 tmp = TAILQ_NEXT(tmp, v_actfreelist); 5950 } while (tmp != NULL && tmp->v_type == VMARKER); 5951 if (tmp != vp) { 5952 mtx_unlock(&mp->mnt_listmtx); 5953 VI_UNLOCK(vp); 5954 goto abort; 5955 } 5956 5957 ret = true; 5958 goto out; 5959 abort: 5960 maybe_yield(); 5961 mtx_lock(&mp->mnt_listmtx); 5962 out: 5963 if (ret) 5964 ASSERT_VI_LOCKED(vp, __func__); 5965 else 5966 ASSERT_VI_UNLOCKED(vp, __func__); 5967 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5968 return (ret); 5969 } 5970 5971 static struct vnode * 5972 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5973 { 5974 struct vnode *vp, *nvp; 5975 5976 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5977 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5978 restart: 5979 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5980 while (vp != NULL) { 5981 if (vp->v_type == VMARKER) { 5982 vp = TAILQ_NEXT(vp, v_actfreelist); 5983 continue; 5984 } 5985 /* 5986 * Try-lock because this is the wrong lock order. If that does 5987 * not succeed, drop the mount vnode list lock and try to 5988 * reacquire it and the vnode interlock in the right order. 5989 */ 5990 if (!VI_TRYLOCK(vp) && 5991 !mnt_vnode_next_active_relock(*mvp, mp, vp)) 5992 goto restart; 5993 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5994 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5995 ("alien vnode on the active list %p %p", vp, mp)); 5996 if (vp->v_mount == mp && !VN_IS_DOOMED(vp)) 5997 break; 5998 nvp = TAILQ_NEXT(vp, v_actfreelist); 5999 VI_UNLOCK(vp); 6000 vp = nvp; 6001 } 6002 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 6003 6004 /* Check if we are done */ 6005 if (vp == NULL) { 6006 mtx_unlock(&mp->mnt_listmtx); 6007 mnt_vnode_markerfree_active(mvp, mp); 6008 return (NULL); 6009 } 6010 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 6011 mtx_unlock(&mp->mnt_listmtx); 6012 ASSERT_VI_LOCKED(vp, "active iter"); 6013 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 6014 return (vp); 6015 } 6016 6017 struct vnode * 6018 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 6019 { 6020 6021 if (should_yield()) 6022 kern_yield(PRI_USER); 6023 mtx_lock(&mp->mnt_listmtx); 6024 return (mnt_vnode_next_active(mvp, mp)); 6025 } 6026 6027 struct vnode * 6028 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 6029 { 6030 struct vnode *vp; 6031 6032 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 6033 MNT_ILOCK(mp); 6034 MNT_REF(mp); 6035 MNT_IUNLOCK(mp); 6036 (*mvp)->v_type = VMARKER; 6037 (*mvp)->v_mount = mp; 6038 6039 mtx_lock(&mp->mnt_listmtx); 6040 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 6041 if (vp == NULL) { 6042 mtx_unlock(&mp->mnt_listmtx); 6043 mnt_vnode_markerfree_active(mvp, mp); 6044 return (NULL); 6045 } 6046 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 6047 return (mnt_vnode_next_active(mvp, mp)); 6048 } 6049 6050 void 6051 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 6052 { 6053 6054 if (*mvp == NULL) 6055 return; 6056 6057 mtx_lock(&mp->mnt_listmtx); 6058 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 6059 mtx_unlock(&mp->mnt_listmtx); 6060 mnt_vnode_markerfree_active(mvp, mp); 6061 } 6062