1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 37 */ 38 39 /* 40 * External virtual filesystem routines 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_ddb.h" 47 #include "opt_watchdog.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/bio.h> 52 #include <sys/buf.h> 53 #include <sys/capsicum.h> 54 #include <sys/condvar.h> 55 #include <sys/conf.h> 56 #include <sys/counter.h> 57 #include <sys/dirent.h> 58 #include <sys/event.h> 59 #include <sys/eventhandler.h> 60 #include <sys/extattr.h> 61 #include <sys/file.h> 62 #include <sys/fcntl.h> 63 #include <sys/jail.h> 64 #include <sys/kdb.h> 65 #include <sys/kernel.h> 66 #include <sys/kthread.h> 67 #include <sys/ktr.h> 68 #include <sys/lockf.h> 69 #include <sys/malloc.h> 70 #include <sys/mount.h> 71 #include <sys/namei.h> 72 #include <sys/pctrie.h> 73 #include <sys/priv.h> 74 #include <sys/reboot.h> 75 #include <sys/refcount.h> 76 #include <sys/rwlock.h> 77 #include <sys/sched.h> 78 #include <sys/sleepqueue.h> 79 #include <sys/smp.h> 80 #include <sys/stat.h> 81 #include <sys/sysctl.h> 82 #include <sys/syslog.h> 83 #include <sys/vmmeter.h> 84 #include <sys/vnode.h> 85 #include <sys/watchdog.h> 86 87 #include <machine/stdarg.h> 88 89 #include <security/mac/mac_framework.h> 90 91 #include <vm/vm.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_extern.h> 94 #include <vm/pmap.h> 95 #include <vm/vm_map.h> 96 #include <vm/vm_page.h> 97 #include <vm/vm_kern.h> 98 #include <vm/uma.h> 99 100 #ifdef DDB 101 #include <ddb/ddb.h> 102 #endif 103 104 static void delmntque(struct vnode *vp); 105 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 106 int slpflag, int slptimeo); 107 static void syncer_shutdown(void *arg, int howto); 108 static int vtryrecycle(struct vnode *vp); 109 static void v_init_counters(struct vnode *); 110 static void v_incr_usecount(struct vnode *); 111 static void v_incr_usecount_locked(struct vnode *); 112 static void v_incr_devcount(struct vnode *); 113 static void v_decr_devcount(struct vnode *); 114 static void vgonel(struct vnode *); 115 static void vfs_knllock(void *arg); 116 static void vfs_knlunlock(void *arg); 117 static void vfs_knl_assert_locked(void *arg); 118 static void vfs_knl_assert_unlocked(void *arg); 119 static void vnlru_return_batches(struct vfsops *mnt_op); 120 static void destroy_vpollinfo(struct vpollinfo *vi); 121 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 122 daddr_t startlbn, daddr_t endlbn); 123 124 /* 125 * These fences are intended for cases where some synchronization is 126 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 127 * and v_usecount) updates. Access to v_iflags is generally synchronized 128 * by the interlock, but we have some internal assertions that check vnode 129 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 130 * for now. 131 */ 132 #ifdef INVARIANTS 133 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 134 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 135 #else 136 #define VNODE_REFCOUNT_FENCE_ACQ() 137 #define VNODE_REFCOUNT_FENCE_REL() 138 #endif 139 140 /* 141 * Number of vnodes in existence. Increased whenever getnewvnode() 142 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode. 143 */ 144 static unsigned long numvnodes; 145 146 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 147 "Number of vnodes in existence"); 148 149 static counter_u64_t vnodes_created; 150 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 151 "Number of vnodes created by getnewvnode"); 152 153 static u_long mnt_free_list_batch = 128; 154 SYSCTL_ULONG(_vfs, OID_AUTO, mnt_free_list_batch, CTLFLAG_RW, 155 &mnt_free_list_batch, 0, "Limit of vnodes held on mnt's free list"); 156 157 /* 158 * Conversion tables for conversion from vnode types to inode formats 159 * and back. 160 */ 161 enum vtype iftovt_tab[16] = { 162 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 163 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON 164 }; 165 int vttoif_tab[10] = { 166 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 167 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 168 }; 169 170 /* 171 * List of vnodes that are ready for recycling. 172 */ 173 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 174 175 /* 176 * "Free" vnode target. Free vnodes are rarely completely free, but are 177 * just ones that are cheap to recycle. Usually they are for files which 178 * have been stat'd but not read; these usually have inode and namecache 179 * data attached to them. This target is the preferred minimum size of a 180 * sub-cache consisting mostly of such files. The system balances the size 181 * of this sub-cache with its complement to try to prevent either from 182 * thrashing while the other is relatively inactive. The targets express 183 * a preference for the best balance. 184 * 185 * "Above" this target there are 2 further targets (watermarks) related 186 * to recyling of free vnodes. In the best-operating case, the cache is 187 * exactly full, the free list has size between vlowat and vhiwat above the 188 * free target, and recycling from it and normal use maintains this state. 189 * Sometimes the free list is below vlowat or even empty, but this state 190 * is even better for immediate use provided the cache is not full. 191 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 192 * ones) to reach one of these states. The watermarks are currently hard- 193 * coded as 4% and 9% of the available space higher. These and the default 194 * of 25% for wantfreevnodes are too large if the memory size is large. 195 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 196 * whenever vnlru_proc() becomes active. 197 */ 198 static u_long wantfreevnodes; 199 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, 200 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes"); 201 static u_long freevnodes; 202 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 203 &freevnodes, 0, "Number of \"free\" vnodes"); 204 205 static counter_u64_t recycles_count; 206 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 207 "Number of vnodes recycled to meet vnode cache targets"); 208 209 /* 210 * Various variables used for debugging the new implementation of 211 * reassignbuf(). 212 * XXX these are probably of (very) limited utility now. 213 */ 214 static int reassignbufcalls; 215 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, 216 "Number of calls to reassignbuf"); 217 218 static counter_u64_t free_owe_inact; 219 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, 220 "Number of times free vnodes kept on active list due to VFS " 221 "owing inactivation"); 222 223 /* To keep more than one thread at a time from running vfs_getnewfsid */ 224 static struct mtx mntid_mtx; 225 226 /* 227 * Lock for any access to the following: 228 * vnode_free_list 229 * numvnodes 230 * freevnodes 231 */ 232 static struct mtx vnode_free_list_mtx; 233 234 /* Publicly exported FS */ 235 struct nfs_public nfs_pub; 236 237 static uma_zone_t buf_trie_zone; 238 239 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 240 static uma_zone_t vnode_zone; 241 static uma_zone_t vnodepoll_zone; 242 243 /* 244 * The workitem queue. 245 * 246 * It is useful to delay writes of file data and filesystem metadata 247 * for tens of seconds so that quickly created and deleted files need 248 * not waste disk bandwidth being created and removed. To realize this, 249 * we append vnodes to a "workitem" queue. When running with a soft 250 * updates implementation, most pending metadata dependencies should 251 * not wait for more than a few seconds. Thus, mounted on block devices 252 * are delayed only about a half the time that file data is delayed. 253 * Similarly, directory updates are more critical, so are only delayed 254 * about a third the time that file data is delayed. Thus, there are 255 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 256 * one each second (driven off the filesystem syncer process). The 257 * syncer_delayno variable indicates the next queue that is to be processed. 258 * Items that need to be processed soon are placed in this queue: 259 * 260 * syncer_workitem_pending[syncer_delayno] 261 * 262 * A delay of fifteen seconds is done by placing the request fifteen 263 * entries later in the queue: 264 * 265 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 266 * 267 */ 268 static int syncer_delayno; 269 static long syncer_mask; 270 LIST_HEAD(synclist, bufobj); 271 static struct synclist *syncer_workitem_pending; 272 /* 273 * The sync_mtx protects: 274 * bo->bo_synclist 275 * sync_vnode_count 276 * syncer_delayno 277 * syncer_state 278 * syncer_workitem_pending 279 * syncer_worklist_len 280 * rushjob 281 */ 282 static struct mtx sync_mtx; 283 static struct cv sync_wakeup; 284 285 #define SYNCER_MAXDELAY 32 286 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 287 static int syncdelay = 30; /* max time to delay syncing data */ 288 static int filedelay = 30; /* time to delay syncing files */ 289 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 290 "Time to delay syncing files (in seconds)"); 291 static int dirdelay = 29; /* time to delay syncing directories */ 292 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 293 "Time to delay syncing directories (in seconds)"); 294 static int metadelay = 28; /* time to delay syncing metadata */ 295 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 296 "Time to delay syncing metadata (in seconds)"); 297 static int rushjob; /* number of slots to run ASAP */ 298 static int stat_rush_requests; /* number of times I/O speeded up */ 299 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 300 "Number of times I/O speeded up (rush requests)"); 301 302 /* 303 * When shutting down the syncer, run it at four times normal speed. 304 */ 305 #define SYNCER_SHUTDOWN_SPEEDUP 4 306 static int sync_vnode_count; 307 static int syncer_worklist_len; 308 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 309 syncer_state; 310 311 /* Target for maximum number of vnodes. */ 312 int desiredvnodes; 313 static int gapvnodes; /* gap between wanted and desired */ 314 static int vhiwat; /* enough extras after expansion */ 315 static int vlowat; /* minimal extras before expansion */ 316 static int vstir; /* nonzero to stir non-free vnodes */ 317 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 318 319 static int 320 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS) 321 { 322 int error, old_desiredvnodes; 323 324 old_desiredvnodes = desiredvnodes; 325 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0) 326 return (error); 327 if (old_desiredvnodes != desiredvnodes) { 328 wantfreevnodes = desiredvnodes / 4; 329 /* XXX locking seems to be incomplete. */ 330 vfs_hash_changesize(desiredvnodes); 331 cache_changesize(desiredvnodes); 332 } 333 return (0); 334 } 335 336 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 337 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0, 338 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes"); 339 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 340 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 341 static int vnlru_nowhere; 342 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 343 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 344 345 static int 346 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) 347 { 348 struct vnode *vp; 349 struct nameidata nd; 350 char *buf; 351 unsigned long ndflags; 352 int error; 353 354 if (req->newptr == NULL) 355 return (EINVAL); 356 if (req->newlen > PATH_MAX) 357 return (E2BIG); 358 359 buf = malloc(PATH_MAX + 1, M_TEMP, M_WAITOK); 360 error = SYSCTL_IN(req, buf, req->newlen); 361 if (error != 0) 362 goto out; 363 364 buf[req->newlen] = '\0'; 365 366 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME; 367 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); 368 if ((error = namei(&nd)) != 0) 369 goto out; 370 vp = nd.ni_vp; 371 372 if ((vp->v_iflag & VI_DOOMED) != 0) { 373 /* 374 * This vnode is being recycled. Return != 0 to let the caller 375 * know that the sysctl had no effect. Return EAGAIN because a 376 * subsequent call will likely succeed (since namei will create 377 * a new vnode if necessary) 378 */ 379 error = EAGAIN; 380 goto putvnode; 381 } 382 383 counter_u64_add(recycles_count, 1); 384 vgone(vp); 385 putvnode: 386 NDFREE(&nd, 0); 387 out: 388 free(buf, M_TEMP); 389 return (error); 390 } 391 392 static int 393 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) 394 { 395 struct thread *td = curthread; 396 struct vnode *vp; 397 struct file *fp; 398 int error; 399 int fd; 400 401 if (req->newptr == NULL) 402 return (EBADF); 403 404 error = sysctl_handle_int(oidp, &fd, 0, req); 405 if (error != 0) 406 return (error); 407 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); 408 if (error != 0) 409 return (error); 410 vp = fp->f_vnode; 411 412 error = vn_lock(vp, LK_EXCLUSIVE); 413 if (error != 0) 414 goto drop; 415 416 counter_u64_add(recycles_count, 1); 417 vgone(vp); 418 VOP_UNLOCK(vp, 0); 419 drop: 420 fdrop(fp, td); 421 return (error); 422 } 423 424 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, 425 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 426 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); 427 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, 428 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, 429 sysctl_ftry_reclaim_vnode, "I", 430 "Try to reclaim a vnode by its file descriptor"); 431 432 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 433 static int vnsz2log; 434 435 /* 436 * Support for the bufobj clean & dirty pctrie. 437 */ 438 static void * 439 buf_trie_alloc(struct pctrie *ptree) 440 { 441 442 return uma_zalloc(buf_trie_zone, M_NOWAIT); 443 } 444 445 static void 446 buf_trie_free(struct pctrie *ptree, void *node) 447 { 448 449 uma_zfree(buf_trie_zone, node); 450 } 451 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 452 453 /* 454 * Initialize the vnode management data structures. 455 * 456 * Reevaluate the following cap on the number of vnodes after the physical 457 * memory size exceeds 512GB. In the limit, as the physical memory size 458 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 459 */ 460 #ifndef MAXVNODES_MAX 461 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */ 462 #endif 463 464 /* 465 * Initialize a vnode as it first enters the zone. 466 */ 467 static int 468 vnode_init(void *mem, int size, int flags) 469 { 470 struct vnode *vp; 471 472 vp = mem; 473 bzero(vp, size); 474 /* 475 * Setup locks. 476 */ 477 vp->v_vnlock = &vp->v_lock; 478 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 479 /* 480 * By default, don't allow shared locks unless filesystems opt-in. 481 */ 482 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 483 LK_NOSHARE | LK_IS_VNODE); 484 /* 485 * Initialize bufobj. 486 */ 487 bufobj_init(&vp->v_bufobj, vp); 488 /* 489 * Initialize namecache. 490 */ 491 LIST_INIT(&vp->v_cache_src); 492 TAILQ_INIT(&vp->v_cache_dst); 493 /* 494 * Initialize rangelocks. 495 */ 496 rangelock_init(&vp->v_rl); 497 return (0); 498 } 499 500 /* 501 * Free a vnode when it is cleared from the zone. 502 */ 503 static void 504 vnode_fini(void *mem, int size) 505 { 506 struct vnode *vp; 507 struct bufobj *bo; 508 509 vp = mem; 510 rangelock_destroy(&vp->v_rl); 511 lockdestroy(vp->v_vnlock); 512 mtx_destroy(&vp->v_interlock); 513 bo = &vp->v_bufobj; 514 rw_destroy(BO_LOCKPTR(bo)); 515 } 516 517 /* 518 * Provide the size of NFS nclnode and NFS fh for calculation of the 519 * vnode memory consumption. The size is specified directly to 520 * eliminate dependency on NFS-private header. 521 * 522 * Other filesystems may use bigger or smaller (like UFS and ZFS) 523 * private inode data, but the NFS-based estimation is ample enough. 524 * Still, we care about differences in the size between 64- and 32-bit 525 * platforms. 526 * 527 * Namecache structure size is heuristically 528 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 529 */ 530 #ifdef _LP64 531 #define NFS_NCLNODE_SZ (528 + 64) 532 #define NC_SZ 148 533 #else 534 #define NFS_NCLNODE_SZ (360 + 32) 535 #define NC_SZ 92 536 #endif 537 538 static void 539 vntblinit(void *dummy __unused) 540 { 541 u_int i; 542 int physvnodes, virtvnodes; 543 544 /* 545 * Desiredvnodes is a function of the physical memory size and the 546 * kernel's heap size. Generally speaking, it scales with the 547 * physical memory size. The ratio of desiredvnodes to the physical 548 * memory size is 1:16 until desiredvnodes exceeds 98,304. 549 * Thereafter, the 550 * marginal ratio of desiredvnodes to the physical memory size is 551 * 1:64. However, desiredvnodes is limited by the kernel's heap 552 * size. The memory required by desiredvnodes vnodes and vm objects 553 * must not exceed 1/10th of the kernel's heap size. 554 */ 555 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 556 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 557 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 558 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 559 desiredvnodes = min(physvnodes, virtvnodes); 560 if (desiredvnodes > MAXVNODES_MAX) { 561 if (bootverbose) 562 printf("Reducing kern.maxvnodes %d -> %d\n", 563 desiredvnodes, MAXVNODES_MAX); 564 desiredvnodes = MAXVNODES_MAX; 565 } 566 wantfreevnodes = desiredvnodes / 4; 567 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 568 TAILQ_INIT(&vnode_free_list); 569 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 570 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 571 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 572 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 573 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 574 /* 575 * Preallocate enough nodes to support one-per buf so that 576 * we can not fail an insert. reassignbuf() callers can not 577 * tolerate the insertion failure. 578 */ 579 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 580 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 581 UMA_ZONE_NOFREE | UMA_ZONE_VM); 582 uma_prealloc(buf_trie_zone, nbuf); 583 584 vnodes_created = counter_u64_alloc(M_WAITOK); 585 recycles_count = counter_u64_alloc(M_WAITOK); 586 free_owe_inact = counter_u64_alloc(M_WAITOK); 587 588 /* 589 * Initialize the filesystem syncer. 590 */ 591 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 592 &syncer_mask); 593 syncer_maxdelay = syncer_mask + 1; 594 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 595 cv_init(&sync_wakeup, "syncer"); 596 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 597 vnsz2log++; 598 vnsz2log--; 599 } 600 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 601 602 603 /* 604 * Mark a mount point as busy. Used to synchronize access and to delay 605 * unmounting. Eventually, mountlist_mtx is not released on failure. 606 * 607 * vfs_busy() is a custom lock, it can block the caller. 608 * vfs_busy() only sleeps if the unmount is active on the mount point. 609 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 610 * vnode belonging to mp. 611 * 612 * Lookup uses vfs_busy() to traverse mount points. 613 * root fs var fs 614 * / vnode lock A / vnode lock (/var) D 615 * /var vnode lock B /log vnode lock(/var/log) E 616 * vfs_busy lock C vfs_busy lock F 617 * 618 * Within each file system, the lock order is C->A->B and F->D->E. 619 * 620 * When traversing across mounts, the system follows that lock order: 621 * 622 * C->A->B 623 * | 624 * +->F->D->E 625 * 626 * The lookup() process for namei("/var") illustrates the process: 627 * VOP_LOOKUP() obtains B while A is held 628 * vfs_busy() obtains a shared lock on F while A and B are held 629 * vput() releases lock on B 630 * vput() releases lock on A 631 * VFS_ROOT() obtains lock on D while shared lock on F is held 632 * vfs_unbusy() releases shared lock on F 633 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 634 * Attempt to lock A (instead of vp_crossmp) while D is held would 635 * violate the global order, causing deadlocks. 636 * 637 * dounmount() locks B while F is drained. 638 */ 639 int 640 vfs_busy(struct mount *mp, int flags) 641 { 642 643 MPASS((flags & ~MBF_MASK) == 0); 644 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 645 646 MNT_ILOCK(mp); 647 MNT_REF(mp); 648 /* 649 * If mount point is currently being unmounted, sleep until the 650 * mount point fate is decided. If thread doing the unmounting fails, 651 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 652 * that this mount point has survived the unmount attempt and vfs_busy 653 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 654 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 655 * about to be really destroyed. vfs_busy needs to release its 656 * reference on the mount point in this case and return with ENOENT, 657 * telling the caller that mount mount it tried to busy is no longer 658 * valid. 659 */ 660 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 661 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 662 MNT_REL(mp); 663 MNT_IUNLOCK(mp); 664 CTR1(KTR_VFS, "%s: failed busying before sleeping", 665 __func__); 666 return (ENOENT); 667 } 668 if (flags & MBF_MNTLSTLOCK) 669 mtx_unlock(&mountlist_mtx); 670 mp->mnt_kern_flag |= MNTK_MWAIT; 671 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 672 if (flags & MBF_MNTLSTLOCK) 673 mtx_lock(&mountlist_mtx); 674 MNT_ILOCK(mp); 675 } 676 if (flags & MBF_MNTLSTLOCK) 677 mtx_unlock(&mountlist_mtx); 678 mp->mnt_lockref++; 679 MNT_IUNLOCK(mp); 680 return (0); 681 } 682 683 /* 684 * Free a busy filesystem. 685 */ 686 void 687 vfs_unbusy(struct mount *mp) 688 { 689 690 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 691 MNT_ILOCK(mp); 692 MNT_REL(mp); 693 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref")); 694 mp->mnt_lockref--; 695 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 696 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 697 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 698 mp->mnt_kern_flag &= ~MNTK_DRAINING; 699 wakeup(&mp->mnt_lockref); 700 } 701 MNT_IUNLOCK(mp); 702 } 703 704 /* 705 * Lookup a mount point by filesystem identifier. 706 */ 707 struct mount * 708 vfs_getvfs(fsid_t *fsid) 709 { 710 struct mount *mp; 711 712 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 713 mtx_lock(&mountlist_mtx); 714 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 715 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 716 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 717 vfs_ref(mp); 718 mtx_unlock(&mountlist_mtx); 719 return (mp); 720 } 721 } 722 mtx_unlock(&mountlist_mtx); 723 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 724 return ((struct mount *) 0); 725 } 726 727 /* 728 * Lookup a mount point by filesystem identifier, busying it before 729 * returning. 730 * 731 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 732 * cache for popular filesystem identifiers. The cache is lockess, using 733 * the fact that struct mount's are never freed. In worst case we may 734 * get pointer to unmounted or even different filesystem, so we have to 735 * check what we got, and go slow way if so. 736 */ 737 struct mount * 738 vfs_busyfs(fsid_t *fsid) 739 { 740 #define FSID_CACHE_SIZE 256 741 typedef struct mount * volatile vmp_t; 742 static vmp_t cache[FSID_CACHE_SIZE]; 743 struct mount *mp; 744 int error; 745 uint32_t hash; 746 747 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 748 hash = fsid->val[0] ^ fsid->val[1]; 749 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 750 mp = cache[hash]; 751 if (mp == NULL || 752 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 753 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 754 goto slow; 755 if (vfs_busy(mp, 0) != 0) { 756 cache[hash] = NULL; 757 goto slow; 758 } 759 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 760 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 761 return (mp); 762 else 763 vfs_unbusy(mp); 764 765 slow: 766 mtx_lock(&mountlist_mtx); 767 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 768 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 769 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 770 error = vfs_busy(mp, MBF_MNTLSTLOCK); 771 if (error) { 772 cache[hash] = NULL; 773 mtx_unlock(&mountlist_mtx); 774 return (NULL); 775 } 776 cache[hash] = mp; 777 return (mp); 778 } 779 } 780 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 781 mtx_unlock(&mountlist_mtx); 782 return ((struct mount *) 0); 783 } 784 785 /* 786 * Check if a user can access privileged mount options. 787 */ 788 int 789 vfs_suser(struct mount *mp, struct thread *td) 790 { 791 int error; 792 793 if (jailed(td->td_ucred)) { 794 /* 795 * If the jail of the calling thread lacks permission for 796 * this type of file system, deny immediately. 797 */ 798 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 799 return (EPERM); 800 801 /* 802 * If the file system was mounted outside the jail of the 803 * calling thread, deny immediately. 804 */ 805 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 806 return (EPERM); 807 } 808 809 /* 810 * If file system supports delegated administration, we don't check 811 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 812 * by the file system itself. 813 * If this is not the user that did original mount, we check for 814 * the PRIV_VFS_MOUNT_OWNER privilege. 815 */ 816 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 817 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 818 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 819 return (error); 820 } 821 return (0); 822 } 823 824 /* 825 * Get a new unique fsid. Try to make its val[0] unique, since this value 826 * will be used to create fake device numbers for stat(). Also try (but 827 * not so hard) make its val[0] unique mod 2^16, since some emulators only 828 * support 16-bit device numbers. We end up with unique val[0]'s for the 829 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 830 * 831 * Keep in mind that several mounts may be running in parallel. Starting 832 * the search one past where the previous search terminated is both a 833 * micro-optimization and a defense against returning the same fsid to 834 * different mounts. 835 */ 836 void 837 vfs_getnewfsid(struct mount *mp) 838 { 839 static uint16_t mntid_base; 840 struct mount *nmp; 841 fsid_t tfsid; 842 int mtype; 843 844 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 845 mtx_lock(&mntid_mtx); 846 mtype = mp->mnt_vfc->vfc_typenum; 847 tfsid.val[1] = mtype; 848 mtype = (mtype & 0xFF) << 24; 849 for (;;) { 850 tfsid.val[0] = makedev(255, 851 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 852 mntid_base++; 853 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 854 break; 855 vfs_rel(nmp); 856 } 857 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 858 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 859 mtx_unlock(&mntid_mtx); 860 } 861 862 /* 863 * Knob to control the precision of file timestamps: 864 * 865 * 0 = seconds only; nanoseconds zeroed. 866 * 1 = seconds and nanoseconds, accurate within 1/HZ. 867 * 2 = seconds and nanoseconds, truncated to microseconds. 868 * >=3 = seconds and nanoseconds, maximum precision. 869 */ 870 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 871 872 static int timestamp_precision = TSP_USEC; 873 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 874 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 875 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 876 "3+: sec + ns (max. precision))"); 877 878 /* 879 * Get a current timestamp. 880 */ 881 void 882 vfs_timestamp(struct timespec *tsp) 883 { 884 struct timeval tv; 885 886 switch (timestamp_precision) { 887 case TSP_SEC: 888 tsp->tv_sec = time_second; 889 tsp->tv_nsec = 0; 890 break; 891 case TSP_HZ: 892 getnanotime(tsp); 893 break; 894 case TSP_USEC: 895 microtime(&tv); 896 TIMEVAL_TO_TIMESPEC(&tv, tsp); 897 break; 898 case TSP_NSEC: 899 default: 900 nanotime(tsp); 901 break; 902 } 903 } 904 905 /* 906 * Set vnode attributes to VNOVAL 907 */ 908 void 909 vattr_null(struct vattr *vap) 910 { 911 912 vap->va_type = VNON; 913 vap->va_size = VNOVAL; 914 vap->va_bytes = VNOVAL; 915 vap->va_mode = VNOVAL; 916 vap->va_nlink = VNOVAL; 917 vap->va_uid = VNOVAL; 918 vap->va_gid = VNOVAL; 919 vap->va_fsid = VNOVAL; 920 vap->va_fileid = VNOVAL; 921 vap->va_blocksize = VNOVAL; 922 vap->va_rdev = VNOVAL; 923 vap->va_atime.tv_sec = VNOVAL; 924 vap->va_atime.tv_nsec = VNOVAL; 925 vap->va_mtime.tv_sec = VNOVAL; 926 vap->va_mtime.tv_nsec = VNOVAL; 927 vap->va_ctime.tv_sec = VNOVAL; 928 vap->va_ctime.tv_nsec = VNOVAL; 929 vap->va_birthtime.tv_sec = VNOVAL; 930 vap->va_birthtime.tv_nsec = VNOVAL; 931 vap->va_flags = VNOVAL; 932 vap->va_gen = VNOVAL; 933 vap->va_vaflags = 0; 934 } 935 936 /* 937 * This routine is called when we have too many vnodes. It attempts 938 * to free <count> vnodes and will potentially free vnodes that still 939 * have VM backing store (VM backing store is typically the cause 940 * of a vnode blowout so we want to do this). Therefore, this operation 941 * is not considered cheap. 942 * 943 * A number of conditions may prevent a vnode from being reclaimed. 944 * the buffer cache may have references on the vnode, a directory 945 * vnode may still have references due to the namei cache representing 946 * underlying files, or the vnode may be in active use. It is not 947 * desirable to reuse such vnodes. These conditions may cause the 948 * number of vnodes to reach some minimum value regardless of what 949 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 950 * 951 * @param mp Try to reclaim vnodes from this mountpoint 952 * @param reclaim_nc_src Only reclaim directories with outgoing namecache 953 * entries if this argument is strue 954 * @param trigger Only reclaim vnodes with fewer than this many resident 955 * pages. 956 * @return The number of vnodes that were reclaimed. 957 */ 958 static int 959 vlrureclaim(struct mount *mp, bool reclaim_nc_src, int trigger) 960 { 961 struct vnode *vp; 962 int count, done, target; 963 964 done = 0; 965 vn_start_write(NULL, &mp, V_WAIT); 966 MNT_ILOCK(mp); 967 count = mp->mnt_nvnodelistsize; 968 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1); 969 target = target / 10 + 1; 970 while (count != 0 && done < target) { 971 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 972 while (vp != NULL && vp->v_type == VMARKER) 973 vp = TAILQ_NEXT(vp, v_nmntvnodes); 974 if (vp == NULL) 975 break; 976 /* 977 * XXX LRU is completely broken for non-free vnodes. First 978 * by calling here in mountpoint order, then by moving 979 * unselected vnodes to the end here, and most grossly by 980 * removing the vlruvp() function that was supposed to 981 * maintain the order. (This function was born broken 982 * since syncer problems prevented it doing anything.) The 983 * order is closer to LRC (C = Created). 984 * 985 * LRU reclaiming of vnodes seems to have last worked in 986 * FreeBSD-3 where LRU wasn't mentioned under any spelling. 987 * Then there was no hold count, and inactive vnodes were 988 * simply put on the free list in LRU order. The separate 989 * lists also break LRU. We prefer to reclaim from the 990 * free list for technical reasons. This tends to thrash 991 * the free list to keep very unrecently used held vnodes. 992 * The problem is mitigated by keeping the free list large. 993 */ 994 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 995 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 996 --count; 997 if (!VI_TRYLOCK(vp)) 998 goto next_iter; 999 /* 1000 * If it's been deconstructed already, it's still 1001 * referenced, or it exceeds the trigger, skip it. 1002 * Also skip free vnodes. We are trying to make space 1003 * to expand the free list, not reduce it. 1004 */ 1005 if (vp->v_usecount || 1006 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1007 ((vp->v_iflag & VI_FREE) != 0) || 1008 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 1009 vp->v_object->resident_page_count > trigger)) { 1010 VI_UNLOCK(vp); 1011 goto next_iter; 1012 } 1013 MNT_IUNLOCK(mp); 1014 vholdl(vp); 1015 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 1016 vdrop(vp); 1017 goto next_iter_mntunlocked; 1018 } 1019 VI_LOCK(vp); 1020 /* 1021 * v_usecount may have been bumped after VOP_LOCK() dropped 1022 * the vnode interlock and before it was locked again. 1023 * 1024 * It is not necessary to recheck VI_DOOMED because it can 1025 * only be set by another thread that holds both the vnode 1026 * lock and vnode interlock. If another thread has the 1027 * vnode lock before we get to VOP_LOCK() and obtains the 1028 * vnode interlock after VOP_LOCK() drops the vnode 1029 * interlock, the other thread will be unable to drop the 1030 * vnode lock before our VOP_LOCK() call fails. 1031 */ 1032 if (vp->v_usecount || 1033 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 1034 (vp->v_iflag & VI_FREE) != 0 || 1035 (vp->v_object != NULL && 1036 vp->v_object->resident_page_count > trigger)) { 1037 VOP_UNLOCK(vp, LK_INTERLOCK); 1038 vdrop(vp); 1039 goto next_iter_mntunlocked; 1040 } 1041 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 1042 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 1043 counter_u64_add(recycles_count, 1); 1044 vgonel(vp); 1045 VOP_UNLOCK(vp, 0); 1046 vdropl(vp); 1047 done++; 1048 next_iter_mntunlocked: 1049 if (!should_yield()) 1050 goto relock_mnt; 1051 goto yield; 1052 next_iter: 1053 if (!should_yield()) 1054 continue; 1055 MNT_IUNLOCK(mp); 1056 yield: 1057 kern_yield(PRI_USER); 1058 relock_mnt: 1059 MNT_ILOCK(mp); 1060 } 1061 MNT_IUNLOCK(mp); 1062 vn_finished_write(mp); 1063 return done; 1064 } 1065 1066 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 1067 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 1068 0, 1069 "limit on vnode free requests per call to the vnlru_free routine"); 1070 1071 /* 1072 * Attempt to reduce the free list by the requested amount. 1073 */ 1074 static void 1075 vnlru_free_locked(int count, struct vfsops *mnt_op) 1076 { 1077 struct vnode *vp; 1078 struct mount *mp; 1079 bool tried_batches; 1080 1081 tried_batches = false; 1082 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1083 if (count > max_vnlru_free) 1084 count = max_vnlru_free; 1085 for (; count > 0; count--) { 1086 vp = TAILQ_FIRST(&vnode_free_list); 1087 /* 1088 * The list can be modified while the free_list_mtx 1089 * has been dropped and vp could be NULL here. 1090 */ 1091 if (vp == NULL) { 1092 if (tried_batches) 1093 break; 1094 mtx_unlock(&vnode_free_list_mtx); 1095 vnlru_return_batches(mnt_op); 1096 tried_batches = true; 1097 mtx_lock(&vnode_free_list_mtx); 1098 continue; 1099 } 1100 1101 VNASSERT(vp->v_op != NULL, vp, 1102 ("vnlru_free: vnode already reclaimed.")); 1103 KASSERT((vp->v_iflag & VI_FREE) != 0, 1104 ("Removing vnode not on freelist")); 1105 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1106 ("Mangling active vnode")); 1107 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 1108 1109 /* 1110 * Don't recycle if our vnode is from different type 1111 * of mount point. Note that mp is type-safe, the 1112 * check does not reach unmapped address even if 1113 * vnode is reclaimed. 1114 * Don't recycle if we can't get the interlock without 1115 * blocking. 1116 */ 1117 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL && 1118 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1119 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist); 1120 continue; 1121 } 1122 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0, 1123 vp, ("vp inconsistent on freelist")); 1124 1125 /* 1126 * The clear of VI_FREE prevents activation of the 1127 * vnode. There is no sense in putting the vnode on 1128 * the mount point active list, only to remove it 1129 * later during recycling. Inline the relevant part 1130 * of vholdl(), to avoid triggering assertions or 1131 * activating. 1132 */ 1133 freevnodes--; 1134 vp->v_iflag &= ~VI_FREE; 1135 VNODE_REFCOUNT_FENCE_REL(); 1136 refcount_acquire(&vp->v_holdcnt); 1137 1138 mtx_unlock(&vnode_free_list_mtx); 1139 VI_UNLOCK(vp); 1140 vtryrecycle(vp); 1141 /* 1142 * If the recycled succeeded this vdrop will actually free 1143 * the vnode. If not it will simply place it back on 1144 * the free list. 1145 */ 1146 vdrop(vp); 1147 mtx_lock(&vnode_free_list_mtx); 1148 } 1149 } 1150 1151 void 1152 vnlru_free(int count, struct vfsops *mnt_op) 1153 { 1154 1155 mtx_lock(&vnode_free_list_mtx); 1156 vnlru_free_locked(count, mnt_op); 1157 mtx_unlock(&vnode_free_list_mtx); 1158 } 1159 1160 1161 /* XXX some names and initialization are bad for limits and watermarks. */ 1162 static int 1163 vspace(void) 1164 { 1165 int space; 1166 1167 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1168 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1169 vlowat = vhiwat / 2; 1170 if (numvnodes > desiredvnodes) 1171 return (0); 1172 space = desiredvnodes - numvnodes; 1173 if (freevnodes > wantfreevnodes) 1174 space += freevnodes - wantfreevnodes; 1175 return (space); 1176 } 1177 1178 static void 1179 vnlru_return_batch_locked(struct mount *mp) 1180 { 1181 struct vnode *vp; 1182 1183 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 1184 1185 if (mp->mnt_tmpfreevnodelistsize == 0) 1186 return; 1187 1188 TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) { 1189 VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp, 1190 ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist")); 1191 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 1192 } 1193 mtx_lock(&vnode_free_list_mtx); 1194 TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist); 1195 freevnodes += mp->mnt_tmpfreevnodelistsize; 1196 mtx_unlock(&vnode_free_list_mtx); 1197 mp->mnt_tmpfreevnodelistsize = 0; 1198 } 1199 1200 static void 1201 vnlru_return_batch(struct mount *mp) 1202 { 1203 1204 mtx_lock(&mp->mnt_listmtx); 1205 vnlru_return_batch_locked(mp); 1206 mtx_unlock(&mp->mnt_listmtx); 1207 } 1208 1209 static void 1210 vnlru_return_batches(struct vfsops *mnt_op) 1211 { 1212 struct mount *mp, *nmp; 1213 bool need_unbusy; 1214 1215 mtx_lock(&mountlist_mtx); 1216 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1217 need_unbusy = false; 1218 if (mnt_op != NULL && mp->mnt_op != mnt_op) 1219 goto next; 1220 if (mp->mnt_tmpfreevnodelistsize == 0) 1221 goto next; 1222 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) { 1223 vnlru_return_batch(mp); 1224 need_unbusy = true; 1225 mtx_lock(&mountlist_mtx); 1226 } 1227 next: 1228 nmp = TAILQ_NEXT(mp, mnt_list); 1229 if (need_unbusy) 1230 vfs_unbusy(mp); 1231 } 1232 mtx_unlock(&mountlist_mtx); 1233 } 1234 1235 /* 1236 * Attempt to recycle vnodes in a context that is always safe to block. 1237 * Calling vlrurecycle() from the bowels of filesystem code has some 1238 * interesting deadlock problems. 1239 */ 1240 static struct proc *vnlruproc; 1241 static int vnlruproc_sig; 1242 1243 static void 1244 vnlru_proc(void) 1245 { 1246 struct mount *mp, *nmp; 1247 unsigned long onumvnodes; 1248 int done, force, trigger, usevnodes; 1249 bool reclaim_nc_src; 1250 1251 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1252 SHUTDOWN_PRI_FIRST); 1253 1254 force = 0; 1255 for (;;) { 1256 kproc_suspend_check(vnlruproc); 1257 mtx_lock(&vnode_free_list_mtx); 1258 /* 1259 * If numvnodes is too large (due to desiredvnodes being 1260 * adjusted using its sysctl, or emergency growth), first 1261 * try to reduce it by discarding from the free list. 1262 */ 1263 if (numvnodes > desiredvnodes) 1264 vnlru_free_locked(numvnodes - desiredvnodes, NULL); 1265 /* 1266 * Sleep if the vnode cache is in a good state. This is 1267 * when it is not over-full and has space for about a 4% 1268 * or 9% expansion (by growing its size or inexcessively 1269 * reducing its free list). Otherwise, try to reclaim 1270 * space for a 10% expansion. 1271 */ 1272 if (vstir && force == 0) { 1273 force = 1; 1274 vstir = 0; 1275 } 1276 if (vspace() >= vlowat && force == 0) { 1277 vnlruproc_sig = 0; 1278 wakeup(&vnlruproc_sig); 1279 msleep(vnlruproc, &vnode_free_list_mtx, 1280 PVFS|PDROP, "vlruwt", hz); 1281 continue; 1282 } 1283 mtx_unlock(&vnode_free_list_mtx); 1284 done = 0; 1285 onumvnodes = numvnodes; 1286 /* 1287 * Calculate parameters for recycling. These are the same 1288 * throughout the loop to give some semblance of fairness. 1289 * The trigger point is to avoid recycling vnodes with lots 1290 * of resident pages. We aren't trying to free memory; we 1291 * are trying to recycle or at least free vnodes. 1292 */ 1293 if (numvnodes <= desiredvnodes) 1294 usevnodes = numvnodes - freevnodes; 1295 else 1296 usevnodes = numvnodes; 1297 if (usevnodes <= 0) 1298 usevnodes = 1; 1299 /* 1300 * The trigger value is is chosen to give a conservatively 1301 * large value to ensure that it alone doesn't prevent 1302 * making progress. The value can easily be so large that 1303 * it is effectively infinite in some congested and 1304 * misconfigured cases, and this is necessary. Normally 1305 * it is about 8 to 100 (pages), which is quite large. 1306 */ 1307 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1308 if (force < 2) 1309 trigger = vsmalltrigger; 1310 reclaim_nc_src = force >= 3; 1311 mtx_lock(&mountlist_mtx); 1312 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1313 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { 1314 nmp = TAILQ_NEXT(mp, mnt_list); 1315 continue; 1316 } 1317 done += vlrureclaim(mp, reclaim_nc_src, trigger); 1318 mtx_lock(&mountlist_mtx); 1319 nmp = TAILQ_NEXT(mp, mnt_list); 1320 vfs_unbusy(mp); 1321 } 1322 mtx_unlock(&mountlist_mtx); 1323 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1324 uma_reclaim(); 1325 if (done == 0) { 1326 if (force == 0 || force == 1) { 1327 force = 2; 1328 continue; 1329 } 1330 if (force == 2) { 1331 force = 3; 1332 continue; 1333 } 1334 force = 0; 1335 vnlru_nowhere++; 1336 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1337 } else 1338 kern_yield(PRI_USER); 1339 /* 1340 * After becoming active to expand above low water, keep 1341 * active until above high water. 1342 */ 1343 force = vspace() < vhiwat; 1344 } 1345 } 1346 1347 static struct kproc_desc vnlru_kp = { 1348 "vnlru", 1349 vnlru_proc, 1350 &vnlruproc 1351 }; 1352 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1353 &vnlru_kp); 1354 1355 /* 1356 * Routines having to do with the management of the vnode table. 1357 */ 1358 1359 /* 1360 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1361 * before we actually vgone(). This function must be called with the vnode 1362 * held to prevent the vnode from being returned to the free list midway 1363 * through vgone(). 1364 */ 1365 static int 1366 vtryrecycle(struct vnode *vp) 1367 { 1368 struct mount *vnmp; 1369 1370 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1371 VNASSERT(vp->v_holdcnt, vp, 1372 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1373 /* 1374 * This vnode may found and locked via some other list, if so we 1375 * can't recycle it yet. 1376 */ 1377 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1378 CTR2(KTR_VFS, 1379 "%s: impossible to recycle, vp %p lock is already held", 1380 __func__, vp); 1381 return (EWOULDBLOCK); 1382 } 1383 /* 1384 * Don't recycle if its filesystem is being suspended. 1385 */ 1386 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1387 VOP_UNLOCK(vp, 0); 1388 CTR2(KTR_VFS, 1389 "%s: impossible to recycle, cannot start the write for %p", 1390 __func__, vp); 1391 return (EBUSY); 1392 } 1393 /* 1394 * If we got this far, we need to acquire the interlock and see if 1395 * anyone picked up this vnode from another list. If not, we will 1396 * mark it with DOOMED via vgonel() so that anyone who does find it 1397 * will skip over it. 1398 */ 1399 VI_LOCK(vp); 1400 if (vp->v_usecount) { 1401 VOP_UNLOCK(vp, LK_INTERLOCK); 1402 vn_finished_write(vnmp); 1403 CTR2(KTR_VFS, 1404 "%s: impossible to recycle, %p is already referenced", 1405 __func__, vp); 1406 return (EBUSY); 1407 } 1408 if ((vp->v_iflag & VI_DOOMED) == 0) { 1409 counter_u64_add(recycles_count, 1); 1410 vgonel(vp); 1411 } 1412 VOP_UNLOCK(vp, LK_INTERLOCK); 1413 vn_finished_write(vnmp); 1414 return (0); 1415 } 1416 1417 static void 1418 vcheckspace(void) 1419 { 1420 1421 if (vspace() < vlowat && vnlruproc_sig == 0) { 1422 vnlruproc_sig = 1; 1423 wakeup(vnlruproc); 1424 } 1425 } 1426 1427 /* 1428 * Wait if necessary for space for a new vnode. 1429 */ 1430 static int 1431 getnewvnode_wait(int suspended) 1432 { 1433 1434 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1435 if (numvnodes >= desiredvnodes) { 1436 if (suspended) { 1437 /* 1438 * The file system is being suspended. We cannot 1439 * risk a deadlock here, so allow allocation of 1440 * another vnode even if this would give too many. 1441 */ 1442 return (0); 1443 } 1444 if (vnlruproc_sig == 0) { 1445 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 1446 wakeup(vnlruproc); 1447 } 1448 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 1449 "vlruwk", hz); 1450 } 1451 /* Post-adjust like the pre-adjust in getnewvnode(). */ 1452 if (numvnodes + 1 > desiredvnodes && freevnodes > 1) 1453 vnlru_free_locked(1, NULL); 1454 return (numvnodes >= desiredvnodes ? ENFILE : 0); 1455 } 1456 1457 /* 1458 * This hack is fragile, and probably not needed any more now that the 1459 * watermark handling works. 1460 */ 1461 void 1462 getnewvnode_reserve(u_int count) 1463 { 1464 struct thread *td; 1465 1466 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */ 1467 /* XXX no longer so quick, but this part is not racy. */ 1468 mtx_lock(&vnode_free_list_mtx); 1469 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes) 1470 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes, 1471 freevnodes - wantfreevnodes), NULL); 1472 mtx_unlock(&vnode_free_list_mtx); 1473 1474 td = curthread; 1475 /* First try to be quick and racy. */ 1476 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) { 1477 td->td_vp_reserv += count; 1478 vcheckspace(); /* XXX no longer so quick, but more racy */ 1479 return; 1480 } else 1481 atomic_subtract_long(&numvnodes, count); 1482 1483 mtx_lock(&vnode_free_list_mtx); 1484 while (count > 0) { 1485 if (getnewvnode_wait(0) == 0) { 1486 count--; 1487 td->td_vp_reserv++; 1488 atomic_add_long(&numvnodes, 1); 1489 } 1490 } 1491 vcheckspace(); 1492 mtx_unlock(&vnode_free_list_mtx); 1493 } 1494 1495 /* 1496 * This hack is fragile, especially if desiredvnodes or wantvnodes are 1497 * misconfgured or changed significantly. Reducing desiredvnodes below 1498 * the reserved amount should cause bizarre behaviour like reducing it 1499 * below the number of active vnodes -- the system will try to reduce 1500 * numvnodes to match, but should fail, so the subtraction below should 1501 * not overflow. 1502 */ 1503 void 1504 getnewvnode_drop_reserve(void) 1505 { 1506 struct thread *td; 1507 1508 td = curthread; 1509 atomic_subtract_long(&numvnodes, td->td_vp_reserv); 1510 td->td_vp_reserv = 0; 1511 } 1512 1513 /* 1514 * Return the next vnode from the free list. 1515 */ 1516 int 1517 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1518 struct vnode **vpp) 1519 { 1520 struct vnode *vp; 1521 struct thread *td; 1522 struct lock_object *lo; 1523 static int cyclecount; 1524 int error __unused; 1525 1526 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1527 vp = NULL; 1528 td = curthread; 1529 if (td->td_vp_reserv > 0) { 1530 td->td_vp_reserv -= 1; 1531 goto alloc; 1532 } 1533 mtx_lock(&vnode_free_list_mtx); 1534 if (numvnodes < desiredvnodes) 1535 cyclecount = 0; 1536 else if (cyclecount++ >= freevnodes) { 1537 cyclecount = 0; 1538 vstir = 1; 1539 } 1540 /* 1541 * Grow the vnode cache if it will not be above its target max 1542 * after growing. Otherwise, if the free list is nonempty, try 1543 * to reclaim 1 item from it before growing the cache (possibly 1544 * above its target max if the reclamation failed or is delayed). 1545 * Otherwise, wait for some space. In all cases, schedule 1546 * vnlru_proc() if we are getting short of space. The watermarks 1547 * should be chosen so that we never wait or even reclaim from 1548 * the free list to below its target minimum. 1549 */ 1550 if (numvnodes + 1 <= desiredvnodes) 1551 ; 1552 else if (freevnodes > 0) 1553 vnlru_free_locked(1, NULL); 1554 else { 1555 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag & 1556 MNTK_SUSPEND)); 1557 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 1558 if (error != 0) { 1559 mtx_unlock(&vnode_free_list_mtx); 1560 return (error); 1561 } 1562 #endif 1563 } 1564 vcheckspace(); 1565 atomic_add_long(&numvnodes, 1); 1566 mtx_unlock(&vnode_free_list_mtx); 1567 alloc: 1568 counter_u64_add(vnodes_created, 1); 1569 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 1570 /* 1571 * Locks are given the generic name "vnode" when created. 1572 * Follow the historic practice of using the filesystem 1573 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1574 * 1575 * Locks live in a witness group keyed on their name. Thus, 1576 * when a lock is renamed, it must also move from the witness 1577 * group of its old name to the witness group of its new name. 1578 * 1579 * The change only needs to be made when the vnode moves 1580 * from one filesystem type to another. We ensure that each 1581 * filesystem use a single static name pointer for its tag so 1582 * that we can compare pointers rather than doing a strcmp(). 1583 */ 1584 lo = &vp->v_vnlock->lock_object; 1585 if (lo->lo_name != tag) { 1586 lo->lo_name = tag; 1587 WITNESS_DESTROY(lo); 1588 WITNESS_INIT(lo, tag); 1589 } 1590 /* 1591 * By default, don't allow shared locks unless filesystems opt-in. 1592 */ 1593 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1594 /* 1595 * Finalize various vnode identity bits. 1596 */ 1597 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1598 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1599 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1600 vp->v_type = VNON; 1601 vp->v_tag = tag; 1602 vp->v_op = vops; 1603 v_init_counters(vp); 1604 vp->v_bufobj.bo_ops = &buf_ops_bio; 1605 #ifdef DIAGNOSTIC 1606 if (mp == NULL && vops != &dead_vnodeops) 1607 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1608 #endif 1609 #ifdef MAC 1610 mac_vnode_init(vp); 1611 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1612 mac_vnode_associate_singlelabel(mp, vp); 1613 #endif 1614 if (mp != NULL) { 1615 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1616 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1617 vp->v_vflag |= VV_NOKNOTE; 1618 } 1619 1620 /* 1621 * For the filesystems which do not use vfs_hash_insert(), 1622 * still initialize v_hash to have vfs_hash_index() useful. 1623 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1624 * its own hashing. 1625 */ 1626 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1627 1628 *vpp = vp; 1629 return (0); 1630 } 1631 1632 /* 1633 * Delete from old mount point vnode list, if on one. 1634 */ 1635 static void 1636 delmntque(struct vnode *vp) 1637 { 1638 struct mount *mp; 1639 int active; 1640 1641 mp = vp->v_mount; 1642 if (mp == NULL) 1643 return; 1644 MNT_ILOCK(mp); 1645 VI_LOCK(vp); 1646 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize, 1647 ("Active vnode list size %d > Vnode list size %d", 1648 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize)); 1649 active = vp->v_iflag & VI_ACTIVE; 1650 vp->v_iflag &= ~VI_ACTIVE; 1651 if (active) { 1652 mtx_lock(&mp->mnt_listmtx); 1653 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); 1654 mp->mnt_activevnodelistsize--; 1655 mtx_unlock(&mp->mnt_listmtx); 1656 } 1657 vp->v_mount = NULL; 1658 VI_UNLOCK(vp); 1659 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1660 ("bad mount point vnode list size")); 1661 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1662 mp->mnt_nvnodelistsize--; 1663 MNT_REL(mp); 1664 MNT_IUNLOCK(mp); 1665 } 1666 1667 static void 1668 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1669 { 1670 1671 vp->v_data = NULL; 1672 vp->v_op = &dead_vnodeops; 1673 vgone(vp); 1674 vput(vp); 1675 } 1676 1677 /* 1678 * Insert into list of vnodes for the new mount point, if available. 1679 */ 1680 int 1681 insmntque1(struct vnode *vp, struct mount *mp, 1682 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1683 { 1684 1685 KASSERT(vp->v_mount == NULL, 1686 ("insmntque: vnode already on per mount vnode list")); 1687 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1688 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1689 1690 /* 1691 * We acquire the vnode interlock early to ensure that the 1692 * vnode cannot be recycled by another process releasing a 1693 * holdcnt on it before we get it on both the vnode list 1694 * and the active vnode list. The mount mutex protects only 1695 * manipulation of the vnode list and the vnode freelist 1696 * mutex protects only manipulation of the active vnode list. 1697 * Hence the need to hold the vnode interlock throughout. 1698 */ 1699 MNT_ILOCK(mp); 1700 VI_LOCK(vp); 1701 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1702 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1703 mp->mnt_nvnodelistsize == 0)) && 1704 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1705 VI_UNLOCK(vp); 1706 MNT_IUNLOCK(mp); 1707 if (dtr != NULL) 1708 dtr(vp, dtr_arg); 1709 return (EBUSY); 1710 } 1711 vp->v_mount = mp; 1712 MNT_REF(mp); 1713 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1714 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1715 ("neg mount point vnode list size")); 1716 mp->mnt_nvnodelistsize++; 1717 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1718 ("Activating already active vnode")); 1719 vp->v_iflag |= VI_ACTIVE; 1720 mtx_lock(&mp->mnt_listmtx); 1721 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 1722 mp->mnt_activevnodelistsize++; 1723 mtx_unlock(&mp->mnt_listmtx); 1724 VI_UNLOCK(vp); 1725 MNT_IUNLOCK(mp); 1726 return (0); 1727 } 1728 1729 int 1730 insmntque(struct vnode *vp, struct mount *mp) 1731 { 1732 1733 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1734 } 1735 1736 /* 1737 * Flush out and invalidate all buffers associated with a bufobj 1738 * Called with the underlying object locked. 1739 */ 1740 int 1741 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1742 { 1743 int error; 1744 1745 BO_LOCK(bo); 1746 if (flags & V_SAVE) { 1747 error = bufobj_wwait(bo, slpflag, slptimeo); 1748 if (error) { 1749 BO_UNLOCK(bo); 1750 return (error); 1751 } 1752 if (bo->bo_dirty.bv_cnt > 0) { 1753 BO_UNLOCK(bo); 1754 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1755 return (error); 1756 /* 1757 * XXX We could save a lock/unlock if this was only 1758 * enabled under INVARIANTS 1759 */ 1760 BO_LOCK(bo); 1761 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1762 panic("vinvalbuf: dirty bufs"); 1763 } 1764 } 1765 /* 1766 * If you alter this loop please notice that interlock is dropped and 1767 * reacquired in flushbuflist. Special care is needed to ensure that 1768 * no race conditions occur from this. 1769 */ 1770 do { 1771 error = flushbuflist(&bo->bo_clean, 1772 flags, bo, slpflag, slptimeo); 1773 if (error == 0 && !(flags & V_CLEANONLY)) 1774 error = flushbuflist(&bo->bo_dirty, 1775 flags, bo, slpflag, slptimeo); 1776 if (error != 0 && error != EAGAIN) { 1777 BO_UNLOCK(bo); 1778 return (error); 1779 } 1780 } while (error != 0); 1781 1782 /* 1783 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1784 * have write I/O in-progress but if there is a VM object then the 1785 * VM object can also have read-I/O in-progress. 1786 */ 1787 do { 1788 bufobj_wwait(bo, 0, 0); 1789 if ((flags & V_VMIO) == 0) { 1790 BO_UNLOCK(bo); 1791 if (bo->bo_object != NULL) { 1792 VM_OBJECT_WLOCK(bo->bo_object); 1793 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1794 VM_OBJECT_WUNLOCK(bo->bo_object); 1795 } 1796 BO_LOCK(bo); 1797 } 1798 } while (bo->bo_numoutput > 0); 1799 BO_UNLOCK(bo); 1800 1801 /* 1802 * Destroy the copy in the VM cache, too. 1803 */ 1804 if (bo->bo_object != NULL && 1805 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1806 VM_OBJECT_WLOCK(bo->bo_object); 1807 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1808 OBJPR_CLEANONLY : 0); 1809 VM_OBJECT_WUNLOCK(bo->bo_object); 1810 } 1811 1812 #ifdef INVARIANTS 1813 BO_LOCK(bo); 1814 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1815 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1816 bo->bo_clean.bv_cnt > 0)) 1817 panic("vinvalbuf: flush failed"); 1818 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1819 bo->bo_dirty.bv_cnt > 0) 1820 panic("vinvalbuf: flush dirty failed"); 1821 BO_UNLOCK(bo); 1822 #endif 1823 return (0); 1824 } 1825 1826 /* 1827 * Flush out and invalidate all buffers associated with a vnode. 1828 * Called with the underlying object locked. 1829 */ 1830 int 1831 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1832 { 1833 1834 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1835 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1836 if (vp->v_object != NULL && vp->v_object->handle != vp) 1837 return (0); 1838 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1839 } 1840 1841 /* 1842 * Flush out buffers on the specified list. 1843 * 1844 */ 1845 static int 1846 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1847 int slptimeo) 1848 { 1849 struct buf *bp, *nbp; 1850 int retval, error; 1851 daddr_t lblkno; 1852 b_xflags_t xflags; 1853 1854 ASSERT_BO_WLOCKED(bo); 1855 1856 retval = 0; 1857 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1858 /* 1859 * If we are flushing both V_NORMAL and V_ALT buffers then 1860 * do not skip any buffers. If we are flushing only V_NORMAL 1861 * buffers then skip buffers marked as BX_ALTDATA. If we are 1862 * flushing only V_ALT buffers then skip buffers not marked 1863 * as BX_ALTDATA. 1864 */ 1865 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) && 1866 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) || 1867 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) { 1868 continue; 1869 } 1870 if (nbp != NULL) { 1871 lblkno = nbp->b_lblkno; 1872 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1873 } 1874 retval = EAGAIN; 1875 error = BUF_TIMELOCK(bp, 1876 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1877 "flushbuf", slpflag, slptimeo); 1878 if (error) { 1879 BO_LOCK(bo); 1880 return (error != ENOLCK ? error : EAGAIN); 1881 } 1882 KASSERT(bp->b_bufobj == bo, 1883 ("bp %p wrong b_bufobj %p should be %p", 1884 bp, bp->b_bufobj, bo)); 1885 /* 1886 * XXX Since there are no node locks for NFS, I 1887 * believe there is a slight chance that a delayed 1888 * write will occur while sleeping just above, so 1889 * check for it. 1890 */ 1891 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1892 (flags & V_SAVE)) { 1893 bremfree(bp); 1894 bp->b_flags |= B_ASYNC; 1895 bwrite(bp); 1896 BO_LOCK(bo); 1897 return (EAGAIN); /* XXX: why not loop ? */ 1898 } 1899 bremfree(bp); 1900 bp->b_flags |= (B_INVAL | B_RELBUF); 1901 bp->b_flags &= ~B_ASYNC; 1902 brelse(bp); 1903 BO_LOCK(bo); 1904 if (nbp == NULL) 1905 break; 1906 nbp = gbincore(bo, lblkno); 1907 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1908 != xflags) 1909 break; /* nbp invalid */ 1910 } 1911 return (retval); 1912 } 1913 1914 int 1915 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 1916 { 1917 struct buf *bp; 1918 int error; 1919 daddr_t lblkno; 1920 1921 ASSERT_BO_LOCKED(bo); 1922 1923 for (lblkno = startn;;) { 1924 again: 1925 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 1926 if (bp == NULL || bp->b_lblkno >= endn || 1927 bp->b_lblkno < startn) 1928 break; 1929 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 1930 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 1931 if (error != 0) { 1932 BO_RLOCK(bo); 1933 if (error == ENOLCK) 1934 goto again; 1935 return (error); 1936 } 1937 KASSERT(bp->b_bufobj == bo, 1938 ("bp %p wrong b_bufobj %p should be %p", 1939 bp, bp->b_bufobj, bo)); 1940 lblkno = bp->b_lblkno + 1; 1941 if ((bp->b_flags & B_MANAGED) == 0) 1942 bremfree(bp); 1943 bp->b_flags |= B_RELBUF; 1944 /* 1945 * In the VMIO case, use the B_NOREUSE flag to hint that the 1946 * pages backing each buffer in the range are unlikely to be 1947 * reused. Dirty buffers will have the hint applied once 1948 * they've been written. 1949 */ 1950 if ((bp->b_flags & B_VMIO) != 0) 1951 bp->b_flags |= B_NOREUSE; 1952 brelse(bp); 1953 BO_RLOCK(bo); 1954 } 1955 return (0); 1956 } 1957 1958 /* 1959 * Truncate a file's buffer and pages to a specified length. This 1960 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1961 * sync activity. 1962 */ 1963 int 1964 vtruncbuf(struct vnode *vp, off_t length, int blksize) 1965 { 1966 struct buf *bp, *nbp; 1967 struct bufobj *bo; 1968 daddr_t startlbn; 1969 1970 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, 1971 vp, blksize, (uintmax_t)length); 1972 1973 /* 1974 * Round up to the *next* lbn. 1975 */ 1976 startlbn = howmany(length, blksize); 1977 1978 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1979 1980 bo = &vp->v_bufobj; 1981 restart_unlocked: 1982 BO_LOCK(bo); 1983 1984 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) 1985 ; 1986 1987 if (length > 0) { 1988 restartsync: 1989 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1990 if (bp->b_lblkno > 0) 1991 continue; 1992 /* 1993 * Since we hold the vnode lock this should only 1994 * fail if we're racing with the buf daemon. 1995 */ 1996 if (BUF_LOCK(bp, 1997 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1998 BO_LOCKPTR(bo)) == ENOLCK) 1999 goto restart_unlocked; 2000 2001 VNASSERT((bp->b_flags & B_DELWRI), vp, 2002 ("buf(%p) on dirty queue without DELWRI", bp)); 2003 2004 bremfree(bp); 2005 bawrite(bp); 2006 BO_LOCK(bo); 2007 goto restartsync; 2008 } 2009 } 2010 2011 bufobj_wwait(bo, 0, 0); 2012 BO_UNLOCK(bo); 2013 vnode_pager_setsize(vp, length); 2014 2015 return (0); 2016 } 2017 2018 /* 2019 * Invalidate the cached pages of a file's buffer within the range of block 2020 * numbers [startlbn, endlbn). 2021 */ 2022 void 2023 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, 2024 int blksize) 2025 { 2026 struct bufobj *bo; 2027 off_t start, end; 2028 2029 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); 2030 2031 start = blksize * startlbn; 2032 end = blksize * endlbn; 2033 2034 bo = &vp->v_bufobj; 2035 BO_LOCK(bo); 2036 MPASS(blksize == bo->bo_bsize); 2037 2038 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) 2039 ; 2040 2041 BO_UNLOCK(bo); 2042 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); 2043 } 2044 2045 static int 2046 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, 2047 daddr_t startlbn, daddr_t endlbn) 2048 { 2049 struct buf *bp, *nbp; 2050 bool anyfreed; 2051 2052 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); 2053 ASSERT_BO_LOCKED(bo); 2054 2055 do { 2056 anyfreed = false; 2057 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 2058 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2059 continue; 2060 if (BUF_LOCK(bp, 2061 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2062 BO_LOCKPTR(bo)) == ENOLCK) { 2063 BO_LOCK(bo); 2064 return (EAGAIN); 2065 } 2066 2067 bremfree(bp); 2068 bp->b_flags |= B_INVAL | B_RELBUF; 2069 bp->b_flags &= ~B_ASYNC; 2070 brelse(bp); 2071 anyfreed = true; 2072 2073 BO_LOCK(bo); 2074 if (nbp != NULL && 2075 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 2076 nbp->b_vp != vp || 2077 (nbp->b_flags & B_DELWRI) != 0)) 2078 return (EAGAIN); 2079 } 2080 2081 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2082 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) 2083 continue; 2084 if (BUF_LOCK(bp, 2085 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 2086 BO_LOCKPTR(bo)) == ENOLCK) { 2087 BO_LOCK(bo); 2088 return (EAGAIN); 2089 } 2090 bremfree(bp); 2091 bp->b_flags |= B_INVAL | B_RELBUF; 2092 bp->b_flags &= ~B_ASYNC; 2093 brelse(bp); 2094 anyfreed = true; 2095 2096 BO_LOCK(bo); 2097 if (nbp != NULL && 2098 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 2099 (nbp->b_vp != vp) || 2100 (nbp->b_flags & B_DELWRI) == 0)) 2101 return (EAGAIN); 2102 } 2103 } while (anyfreed); 2104 return (0); 2105 } 2106 2107 static void 2108 buf_vlist_remove(struct buf *bp) 2109 { 2110 struct bufv *bv; 2111 2112 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 2113 ASSERT_BO_WLOCKED(bp->b_bufobj); 2114 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 2115 (BX_VNDIRTY|BX_VNCLEAN), 2116 ("buf_vlist_remove: Buf %p is on two lists", bp)); 2117 if (bp->b_xflags & BX_VNDIRTY) 2118 bv = &bp->b_bufobj->bo_dirty; 2119 else 2120 bv = &bp->b_bufobj->bo_clean; 2121 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 2122 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 2123 bv->bv_cnt--; 2124 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 2125 } 2126 2127 /* 2128 * Add the buffer to the sorted clean or dirty block list. 2129 * 2130 * NOTE: xflags is passed as a constant, optimizing this inline function! 2131 */ 2132 static void 2133 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 2134 { 2135 struct bufv *bv; 2136 struct buf *n; 2137 int error; 2138 2139 ASSERT_BO_WLOCKED(bo); 2140 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 2141 ("dead bo %p", bo)); 2142 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 2143 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 2144 bp->b_xflags |= xflags; 2145 if (xflags & BX_VNDIRTY) 2146 bv = &bo->bo_dirty; 2147 else 2148 bv = &bo->bo_clean; 2149 2150 /* 2151 * Keep the list ordered. Optimize empty list insertion. Assume 2152 * we tend to grow at the tail so lookup_le should usually be cheaper 2153 * than _ge. 2154 */ 2155 if (bv->bv_cnt == 0 || 2156 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2157 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2158 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2159 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2160 else 2161 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2162 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2163 if (error) 2164 panic("buf_vlist_add: Preallocated nodes insufficient."); 2165 bv->bv_cnt++; 2166 } 2167 2168 /* 2169 * Look up a buffer using the buffer tries. 2170 */ 2171 struct buf * 2172 gbincore(struct bufobj *bo, daddr_t lblkno) 2173 { 2174 struct buf *bp; 2175 2176 ASSERT_BO_LOCKED(bo); 2177 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2178 if (bp != NULL) 2179 return (bp); 2180 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2181 } 2182 2183 /* 2184 * Associate a buffer with a vnode. 2185 */ 2186 void 2187 bgetvp(struct vnode *vp, struct buf *bp) 2188 { 2189 struct bufobj *bo; 2190 2191 bo = &vp->v_bufobj; 2192 ASSERT_BO_WLOCKED(bo); 2193 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2194 2195 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2196 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2197 ("bgetvp: bp already attached! %p", bp)); 2198 2199 vhold(vp); 2200 bp->b_vp = vp; 2201 bp->b_bufobj = bo; 2202 /* 2203 * Insert onto list for new vnode. 2204 */ 2205 buf_vlist_add(bp, bo, BX_VNCLEAN); 2206 } 2207 2208 /* 2209 * Disassociate a buffer from a vnode. 2210 */ 2211 void 2212 brelvp(struct buf *bp) 2213 { 2214 struct bufobj *bo; 2215 struct vnode *vp; 2216 2217 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2218 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2219 2220 /* 2221 * Delete from old vnode list, if on one. 2222 */ 2223 vp = bp->b_vp; /* XXX */ 2224 bo = bp->b_bufobj; 2225 BO_LOCK(bo); 2226 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2227 buf_vlist_remove(bp); 2228 else 2229 panic("brelvp: Buffer %p not on queue.", bp); 2230 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2231 bo->bo_flag &= ~BO_ONWORKLST; 2232 mtx_lock(&sync_mtx); 2233 LIST_REMOVE(bo, bo_synclist); 2234 syncer_worklist_len--; 2235 mtx_unlock(&sync_mtx); 2236 } 2237 bp->b_vp = NULL; 2238 bp->b_bufobj = NULL; 2239 BO_UNLOCK(bo); 2240 vdrop(vp); 2241 } 2242 2243 /* 2244 * Add an item to the syncer work queue. 2245 */ 2246 static void 2247 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2248 { 2249 int slot; 2250 2251 ASSERT_BO_WLOCKED(bo); 2252 2253 mtx_lock(&sync_mtx); 2254 if (bo->bo_flag & BO_ONWORKLST) 2255 LIST_REMOVE(bo, bo_synclist); 2256 else { 2257 bo->bo_flag |= BO_ONWORKLST; 2258 syncer_worklist_len++; 2259 } 2260 2261 if (delay > syncer_maxdelay - 2) 2262 delay = syncer_maxdelay - 2; 2263 slot = (syncer_delayno + delay) & syncer_mask; 2264 2265 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2266 mtx_unlock(&sync_mtx); 2267 } 2268 2269 static int 2270 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2271 { 2272 int error, len; 2273 2274 mtx_lock(&sync_mtx); 2275 len = syncer_worklist_len - sync_vnode_count; 2276 mtx_unlock(&sync_mtx); 2277 error = SYSCTL_OUT(req, &len, sizeof(len)); 2278 return (error); 2279 } 2280 2281 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 2282 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2283 2284 static struct proc *updateproc; 2285 static void sched_sync(void); 2286 static struct kproc_desc up_kp = { 2287 "syncer", 2288 sched_sync, 2289 &updateproc 2290 }; 2291 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2292 2293 static int 2294 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2295 { 2296 struct vnode *vp; 2297 struct mount *mp; 2298 2299 *bo = LIST_FIRST(slp); 2300 if (*bo == NULL) 2301 return (0); 2302 vp = bo2vnode(*bo); 2303 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2304 return (1); 2305 /* 2306 * We use vhold in case the vnode does not 2307 * successfully sync. vhold prevents the vnode from 2308 * going away when we unlock the sync_mtx so that 2309 * we can acquire the vnode interlock. 2310 */ 2311 vholdl(vp); 2312 mtx_unlock(&sync_mtx); 2313 VI_UNLOCK(vp); 2314 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2315 vdrop(vp); 2316 mtx_lock(&sync_mtx); 2317 return (*bo == LIST_FIRST(slp)); 2318 } 2319 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2320 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2321 VOP_UNLOCK(vp, 0); 2322 vn_finished_write(mp); 2323 BO_LOCK(*bo); 2324 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2325 /* 2326 * Put us back on the worklist. The worklist 2327 * routine will remove us from our current 2328 * position and then add us back in at a later 2329 * position. 2330 */ 2331 vn_syncer_add_to_worklist(*bo, syncdelay); 2332 } 2333 BO_UNLOCK(*bo); 2334 vdrop(vp); 2335 mtx_lock(&sync_mtx); 2336 return (0); 2337 } 2338 2339 static int first_printf = 1; 2340 2341 /* 2342 * System filesystem synchronizer daemon. 2343 */ 2344 static void 2345 sched_sync(void) 2346 { 2347 struct synclist *next, *slp; 2348 struct bufobj *bo; 2349 long starttime; 2350 struct thread *td = curthread; 2351 int last_work_seen; 2352 int net_worklist_len; 2353 int syncer_final_iter; 2354 int error; 2355 2356 last_work_seen = 0; 2357 syncer_final_iter = 0; 2358 syncer_state = SYNCER_RUNNING; 2359 starttime = time_uptime; 2360 td->td_pflags |= TDP_NORUNNINGBUF; 2361 2362 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2363 SHUTDOWN_PRI_LAST); 2364 2365 mtx_lock(&sync_mtx); 2366 for (;;) { 2367 if (syncer_state == SYNCER_FINAL_DELAY && 2368 syncer_final_iter == 0) { 2369 mtx_unlock(&sync_mtx); 2370 kproc_suspend_check(td->td_proc); 2371 mtx_lock(&sync_mtx); 2372 } 2373 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2374 if (syncer_state != SYNCER_RUNNING && 2375 starttime != time_uptime) { 2376 if (first_printf) { 2377 printf("\nSyncing disks, vnodes remaining... "); 2378 first_printf = 0; 2379 } 2380 printf("%d ", net_worklist_len); 2381 } 2382 starttime = time_uptime; 2383 2384 /* 2385 * Push files whose dirty time has expired. Be careful 2386 * of interrupt race on slp queue. 2387 * 2388 * Skip over empty worklist slots when shutting down. 2389 */ 2390 do { 2391 slp = &syncer_workitem_pending[syncer_delayno]; 2392 syncer_delayno += 1; 2393 if (syncer_delayno == syncer_maxdelay) 2394 syncer_delayno = 0; 2395 next = &syncer_workitem_pending[syncer_delayno]; 2396 /* 2397 * If the worklist has wrapped since the 2398 * it was emptied of all but syncer vnodes, 2399 * switch to the FINAL_DELAY state and run 2400 * for one more second. 2401 */ 2402 if (syncer_state == SYNCER_SHUTTING_DOWN && 2403 net_worklist_len == 0 && 2404 last_work_seen == syncer_delayno) { 2405 syncer_state = SYNCER_FINAL_DELAY; 2406 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2407 } 2408 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2409 syncer_worklist_len > 0); 2410 2411 /* 2412 * Keep track of the last time there was anything 2413 * on the worklist other than syncer vnodes. 2414 * Return to the SHUTTING_DOWN state if any 2415 * new work appears. 2416 */ 2417 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2418 last_work_seen = syncer_delayno; 2419 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2420 syncer_state = SYNCER_SHUTTING_DOWN; 2421 while (!LIST_EMPTY(slp)) { 2422 error = sync_vnode(slp, &bo, td); 2423 if (error == 1) { 2424 LIST_REMOVE(bo, bo_synclist); 2425 LIST_INSERT_HEAD(next, bo, bo_synclist); 2426 continue; 2427 } 2428 2429 if (first_printf == 0) { 2430 /* 2431 * Drop the sync mutex, because some watchdog 2432 * drivers need to sleep while patting 2433 */ 2434 mtx_unlock(&sync_mtx); 2435 wdog_kern_pat(WD_LASTVAL); 2436 mtx_lock(&sync_mtx); 2437 } 2438 2439 } 2440 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2441 syncer_final_iter--; 2442 /* 2443 * The variable rushjob allows the kernel to speed up the 2444 * processing of the filesystem syncer process. A rushjob 2445 * value of N tells the filesystem syncer to process the next 2446 * N seconds worth of work on its queue ASAP. Currently rushjob 2447 * is used by the soft update code to speed up the filesystem 2448 * syncer process when the incore state is getting so far 2449 * ahead of the disk that the kernel memory pool is being 2450 * threatened with exhaustion. 2451 */ 2452 if (rushjob > 0) { 2453 rushjob -= 1; 2454 continue; 2455 } 2456 /* 2457 * Just sleep for a short period of time between 2458 * iterations when shutting down to allow some I/O 2459 * to happen. 2460 * 2461 * If it has taken us less than a second to process the 2462 * current work, then wait. Otherwise start right over 2463 * again. We can still lose time if any single round 2464 * takes more than two seconds, but it does not really 2465 * matter as we are just trying to generally pace the 2466 * filesystem activity. 2467 */ 2468 if (syncer_state != SYNCER_RUNNING || 2469 time_uptime == starttime) { 2470 thread_lock(td); 2471 sched_prio(td, PPAUSE); 2472 thread_unlock(td); 2473 } 2474 if (syncer_state != SYNCER_RUNNING) 2475 cv_timedwait(&sync_wakeup, &sync_mtx, 2476 hz / SYNCER_SHUTDOWN_SPEEDUP); 2477 else if (time_uptime == starttime) 2478 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2479 } 2480 } 2481 2482 /* 2483 * Request the syncer daemon to speed up its work. 2484 * We never push it to speed up more than half of its 2485 * normal turn time, otherwise it could take over the cpu. 2486 */ 2487 int 2488 speedup_syncer(void) 2489 { 2490 int ret = 0; 2491 2492 mtx_lock(&sync_mtx); 2493 if (rushjob < syncdelay / 2) { 2494 rushjob += 1; 2495 stat_rush_requests += 1; 2496 ret = 1; 2497 } 2498 mtx_unlock(&sync_mtx); 2499 cv_broadcast(&sync_wakeup); 2500 return (ret); 2501 } 2502 2503 /* 2504 * Tell the syncer to speed up its work and run though its work 2505 * list several times, then tell it to shut down. 2506 */ 2507 static void 2508 syncer_shutdown(void *arg, int howto) 2509 { 2510 2511 if (howto & RB_NOSYNC) 2512 return; 2513 mtx_lock(&sync_mtx); 2514 syncer_state = SYNCER_SHUTTING_DOWN; 2515 rushjob = 0; 2516 mtx_unlock(&sync_mtx); 2517 cv_broadcast(&sync_wakeup); 2518 kproc_shutdown(arg, howto); 2519 } 2520 2521 void 2522 syncer_suspend(void) 2523 { 2524 2525 syncer_shutdown(updateproc, 0); 2526 } 2527 2528 void 2529 syncer_resume(void) 2530 { 2531 2532 mtx_lock(&sync_mtx); 2533 first_printf = 1; 2534 syncer_state = SYNCER_RUNNING; 2535 mtx_unlock(&sync_mtx); 2536 cv_broadcast(&sync_wakeup); 2537 kproc_resume(updateproc); 2538 } 2539 2540 /* 2541 * Reassign a buffer from one vnode to another. 2542 * Used to assign file specific control information 2543 * (indirect blocks) to the vnode to which they belong. 2544 */ 2545 void 2546 reassignbuf(struct buf *bp) 2547 { 2548 struct vnode *vp; 2549 struct bufobj *bo; 2550 int delay; 2551 #ifdef INVARIANTS 2552 struct bufv *bv; 2553 #endif 2554 2555 vp = bp->b_vp; 2556 bo = bp->b_bufobj; 2557 ++reassignbufcalls; 2558 2559 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2560 bp, bp->b_vp, bp->b_flags); 2561 /* 2562 * B_PAGING flagged buffers cannot be reassigned because their vp 2563 * is not fully linked in. 2564 */ 2565 if (bp->b_flags & B_PAGING) 2566 panic("cannot reassign paging buffer"); 2567 2568 /* 2569 * Delete from old vnode list, if on one. 2570 */ 2571 BO_LOCK(bo); 2572 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2573 buf_vlist_remove(bp); 2574 else 2575 panic("reassignbuf: Buffer %p not on queue.", bp); 2576 /* 2577 * If dirty, put on list of dirty buffers; otherwise insert onto list 2578 * of clean buffers. 2579 */ 2580 if (bp->b_flags & B_DELWRI) { 2581 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2582 switch (vp->v_type) { 2583 case VDIR: 2584 delay = dirdelay; 2585 break; 2586 case VCHR: 2587 delay = metadelay; 2588 break; 2589 default: 2590 delay = filedelay; 2591 } 2592 vn_syncer_add_to_worklist(bo, delay); 2593 } 2594 buf_vlist_add(bp, bo, BX_VNDIRTY); 2595 } else { 2596 buf_vlist_add(bp, bo, BX_VNCLEAN); 2597 2598 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2599 mtx_lock(&sync_mtx); 2600 LIST_REMOVE(bo, bo_synclist); 2601 syncer_worklist_len--; 2602 mtx_unlock(&sync_mtx); 2603 bo->bo_flag &= ~BO_ONWORKLST; 2604 } 2605 } 2606 #ifdef INVARIANTS 2607 bv = &bo->bo_clean; 2608 bp = TAILQ_FIRST(&bv->bv_hd); 2609 KASSERT(bp == NULL || bp->b_bufobj == bo, 2610 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2611 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2612 KASSERT(bp == NULL || bp->b_bufobj == bo, 2613 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2614 bv = &bo->bo_dirty; 2615 bp = TAILQ_FIRST(&bv->bv_hd); 2616 KASSERT(bp == NULL || bp->b_bufobj == bo, 2617 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2618 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2619 KASSERT(bp == NULL || bp->b_bufobj == bo, 2620 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2621 #endif 2622 BO_UNLOCK(bo); 2623 } 2624 2625 static void 2626 v_init_counters(struct vnode *vp) 2627 { 2628 2629 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2630 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2631 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2632 2633 refcount_init(&vp->v_holdcnt, 1); 2634 refcount_init(&vp->v_usecount, 1); 2635 } 2636 2637 static void 2638 v_incr_usecount_locked(struct vnode *vp) 2639 { 2640 2641 ASSERT_VI_LOCKED(vp, __func__); 2642 if ((vp->v_iflag & VI_OWEINACT) != 0) { 2643 VNASSERT(vp->v_usecount == 0, vp, 2644 ("vnode with usecount and VI_OWEINACT set")); 2645 vp->v_iflag &= ~VI_OWEINACT; 2646 } 2647 refcount_acquire(&vp->v_usecount); 2648 v_incr_devcount(vp); 2649 } 2650 2651 /* 2652 * Increment the use count on the vnode, taking care to reference 2653 * the driver's usecount if this is a chardev. 2654 */ 2655 static void 2656 v_incr_usecount(struct vnode *vp) 2657 { 2658 2659 ASSERT_VI_UNLOCKED(vp, __func__); 2660 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2661 2662 if (vp->v_type != VCHR && 2663 refcount_acquire_if_not_zero(&vp->v_usecount)) { 2664 VNODE_REFCOUNT_FENCE_ACQ(); 2665 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2666 ("vnode with usecount and VI_OWEINACT set")); 2667 } else { 2668 VI_LOCK(vp); 2669 v_incr_usecount_locked(vp); 2670 VI_UNLOCK(vp); 2671 } 2672 } 2673 2674 /* 2675 * Increment si_usecount of the associated device, if any. 2676 */ 2677 static void 2678 v_incr_devcount(struct vnode *vp) 2679 { 2680 2681 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2682 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2683 dev_lock(); 2684 vp->v_rdev->si_usecount++; 2685 dev_unlock(); 2686 } 2687 } 2688 2689 /* 2690 * Decrement si_usecount of the associated device, if any. 2691 */ 2692 static void 2693 v_decr_devcount(struct vnode *vp) 2694 { 2695 2696 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2697 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2698 dev_lock(); 2699 vp->v_rdev->si_usecount--; 2700 dev_unlock(); 2701 } 2702 } 2703 2704 /* 2705 * Grab a particular vnode from the free list, increment its 2706 * reference count and lock it. VI_DOOMED is set if the vnode 2707 * is being destroyed. Only callers who specify LK_RETRY will 2708 * see doomed vnodes. If inactive processing was delayed in 2709 * vput try to do it here. 2710 * 2711 * Notes on lockless counter manipulation: 2712 * _vhold, vputx and other routines make various decisions based 2713 * on either holdcnt or usecount being 0. As long as either counter 2714 * is not transitioning 0->1 nor 1->0, the manipulation can be done 2715 * with atomic operations. Otherwise the interlock is taken covering 2716 * both the atomic and additional actions. 2717 */ 2718 int 2719 vget(struct vnode *vp, int flags, struct thread *td) 2720 { 2721 int error, oweinact; 2722 2723 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2724 ("vget: invalid lock operation")); 2725 2726 if ((flags & LK_INTERLOCK) != 0) 2727 ASSERT_VI_LOCKED(vp, __func__); 2728 else 2729 ASSERT_VI_UNLOCKED(vp, __func__); 2730 if ((flags & LK_VNHELD) != 0) 2731 VNASSERT((vp->v_holdcnt > 0), vp, 2732 ("vget: LK_VNHELD passed but vnode not held")); 2733 2734 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2735 2736 if ((flags & LK_VNHELD) == 0) 2737 _vhold(vp, (flags & LK_INTERLOCK) != 0); 2738 2739 if ((error = vn_lock(vp, flags)) != 0) { 2740 vdrop(vp); 2741 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2742 vp); 2743 return (error); 2744 } 2745 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2746 panic("vget: vn_lock failed to return ENOENT\n"); 2747 /* 2748 * We don't guarantee that any particular close will 2749 * trigger inactive processing so just make a best effort 2750 * here at preventing a reference to a removed file. If 2751 * we don't succeed no harm is done. 2752 * 2753 * Upgrade our holdcnt to a usecount. 2754 */ 2755 if (vp->v_type == VCHR || 2756 !refcount_acquire_if_not_zero(&vp->v_usecount)) { 2757 VI_LOCK(vp); 2758 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2759 oweinact = 0; 2760 } else { 2761 oweinact = 1; 2762 vp->v_iflag &= ~VI_OWEINACT; 2763 VNODE_REFCOUNT_FENCE_REL(); 2764 } 2765 refcount_acquire(&vp->v_usecount); 2766 v_incr_devcount(vp); 2767 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2768 (flags & LK_NOWAIT) == 0) 2769 vinactive(vp, td); 2770 VI_UNLOCK(vp); 2771 } 2772 return (0); 2773 } 2774 2775 /* 2776 * Increase the reference (use) and hold count of a vnode. 2777 * This will also remove the vnode from the free list if it is presently free. 2778 */ 2779 void 2780 vref(struct vnode *vp) 2781 { 2782 2783 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2784 _vhold(vp, false); 2785 v_incr_usecount(vp); 2786 } 2787 2788 void 2789 vrefl(struct vnode *vp) 2790 { 2791 2792 ASSERT_VI_LOCKED(vp, __func__); 2793 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2794 _vhold(vp, true); 2795 v_incr_usecount_locked(vp); 2796 } 2797 2798 void 2799 vrefact(struct vnode *vp) 2800 { 2801 2802 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2803 if (__predict_false(vp->v_type == VCHR)) { 2804 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 2805 ("%s: wrong ref counts", __func__)); 2806 vref(vp); 2807 return; 2808 } 2809 #ifdef INVARIANTS 2810 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 2811 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__)); 2812 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2813 VNASSERT(old > 0, vp, ("%s: wrong use count", __func__)); 2814 #else 2815 refcount_acquire(&vp->v_holdcnt); 2816 refcount_acquire(&vp->v_usecount); 2817 #endif 2818 } 2819 2820 /* 2821 * Return reference count of a vnode. 2822 * 2823 * The results of this call are only guaranteed when some mechanism is used to 2824 * stop other processes from gaining references to the vnode. This may be the 2825 * case if the caller holds the only reference. This is also useful when stale 2826 * data is acceptable as race conditions may be accounted for by some other 2827 * means. 2828 */ 2829 int 2830 vrefcnt(struct vnode *vp) 2831 { 2832 2833 return (vp->v_usecount); 2834 } 2835 2836 #define VPUTX_VRELE 1 2837 #define VPUTX_VPUT 2 2838 #define VPUTX_VUNREF 3 2839 2840 /* 2841 * Decrement the use and hold counts for a vnode. 2842 * 2843 * See an explanation near vget() as to why atomic operation is safe. 2844 */ 2845 static void 2846 vputx(struct vnode *vp, int func) 2847 { 2848 int error; 2849 2850 KASSERT(vp != NULL, ("vputx: null vp")); 2851 if (func == VPUTX_VUNREF) 2852 ASSERT_VOP_LOCKED(vp, "vunref"); 2853 else if (func == VPUTX_VPUT) 2854 ASSERT_VOP_LOCKED(vp, "vput"); 2855 else 2856 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); 2857 ASSERT_VI_UNLOCKED(vp, __func__); 2858 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2859 2860 if (vp->v_type != VCHR && 2861 refcount_release_if_not_last(&vp->v_usecount)) { 2862 if (func == VPUTX_VPUT) 2863 VOP_UNLOCK(vp, 0); 2864 vdrop(vp); 2865 return; 2866 } 2867 2868 VI_LOCK(vp); 2869 2870 /* 2871 * We want to hold the vnode until the inactive finishes to 2872 * prevent vgone() races. We drop the use count here and the 2873 * hold count below when we're done. 2874 */ 2875 if (!refcount_release(&vp->v_usecount) || 2876 (vp->v_iflag & VI_DOINGINACT)) { 2877 if (func == VPUTX_VPUT) 2878 VOP_UNLOCK(vp, 0); 2879 v_decr_devcount(vp); 2880 vdropl(vp); 2881 return; 2882 } 2883 2884 v_decr_devcount(vp); 2885 2886 error = 0; 2887 2888 if (vp->v_usecount != 0) { 2889 vn_printf(vp, "vputx: usecount not zero for vnode "); 2890 panic("vputx: usecount not zero"); 2891 } 2892 2893 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); 2894 2895 /* 2896 * We must call VOP_INACTIVE with the node locked. Mark 2897 * as VI_DOINGINACT to avoid recursion. 2898 */ 2899 vp->v_iflag |= VI_OWEINACT; 2900 switch (func) { 2901 case VPUTX_VRELE: 2902 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2903 VI_LOCK(vp); 2904 break; 2905 case VPUTX_VPUT: 2906 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2907 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 2908 LK_NOWAIT); 2909 VI_LOCK(vp); 2910 } 2911 break; 2912 case VPUTX_VUNREF: 2913 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2914 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 2915 VI_LOCK(vp); 2916 } 2917 break; 2918 } 2919 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, 2920 ("vnode with usecount and VI_OWEINACT set")); 2921 if (error == 0) { 2922 if (vp->v_iflag & VI_OWEINACT) 2923 vinactive(vp, curthread); 2924 if (func != VPUTX_VUNREF) 2925 VOP_UNLOCK(vp, 0); 2926 } 2927 vdropl(vp); 2928 } 2929 2930 /* 2931 * Vnode put/release. 2932 * If count drops to zero, call inactive routine and return to freelist. 2933 */ 2934 void 2935 vrele(struct vnode *vp) 2936 { 2937 2938 vputx(vp, VPUTX_VRELE); 2939 } 2940 2941 /* 2942 * Release an already locked vnode. This give the same effects as 2943 * unlock+vrele(), but takes less time and avoids releasing and 2944 * re-aquiring the lock (as vrele() acquires the lock internally.) 2945 */ 2946 void 2947 vput(struct vnode *vp) 2948 { 2949 2950 vputx(vp, VPUTX_VPUT); 2951 } 2952 2953 /* 2954 * Release an exclusively locked vnode. Do not unlock the vnode lock. 2955 */ 2956 void 2957 vunref(struct vnode *vp) 2958 { 2959 2960 vputx(vp, VPUTX_VUNREF); 2961 } 2962 2963 /* 2964 * Increase the hold count and activate if this is the first reference. 2965 */ 2966 void 2967 _vhold(struct vnode *vp, bool locked) 2968 { 2969 struct mount *mp; 2970 2971 if (locked) 2972 ASSERT_VI_LOCKED(vp, __func__); 2973 else 2974 ASSERT_VI_UNLOCKED(vp, __func__); 2975 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2976 if (!locked) { 2977 if (refcount_acquire_if_not_zero(&vp->v_holdcnt)) { 2978 VNODE_REFCOUNT_FENCE_ACQ(); 2979 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2980 ("_vhold: vnode with holdcnt is free")); 2981 return; 2982 } 2983 VI_LOCK(vp); 2984 } 2985 if ((vp->v_iflag & VI_FREE) == 0) { 2986 refcount_acquire(&vp->v_holdcnt); 2987 if (!locked) 2988 VI_UNLOCK(vp); 2989 return; 2990 } 2991 VNASSERT(vp->v_holdcnt == 0, vp, 2992 ("%s: wrong hold count", __func__)); 2993 VNASSERT(vp->v_op != NULL, vp, 2994 ("%s: vnode already reclaimed.", __func__)); 2995 /* 2996 * Remove a vnode from the free list, mark it as in use, 2997 * and put it on the active list. 2998 */ 2999 VNASSERT(vp->v_mount != NULL, vp, 3000 ("_vhold: vnode not on per mount vnode list")); 3001 mp = vp->v_mount; 3002 mtx_lock(&mp->mnt_listmtx); 3003 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { 3004 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 3005 mp->mnt_tmpfreevnodelistsize--; 3006 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 3007 } else { 3008 mtx_lock(&vnode_free_list_mtx); 3009 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 3010 freevnodes--; 3011 mtx_unlock(&vnode_free_list_mtx); 3012 } 3013 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 3014 ("Activating already active vnode")); 3015 vp->v_iflag &= ~VI_FREE; 3016 vp->v_iflag |= VI_ACTIVE; 3017 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 3018 mp->mnt_activevnodelistsize++; 3019 mtx_unlock(&mp->mnt_listmtx); 3020 refcount_acquire(&vp->v_holdcnt); 3021 if (!locked) 3022 VI_UNLOCK(vp); 3023 } 3024 3025 /* 3026 * Drop the hold count of the vnode. If this is the last reference to 3027 * the vnode we place it on the free list unless it has been vgone'd 3028 * (marked VI_DOOMED) in which case we will free it. 3029 * 3030 * Because the vnode vm object keeps a hold reference on the vnode if 3031 * there is at least one resident non-cached page, the vnode cannot 3032 * leave the active list without the page cleanup done. 3033 */ 3034 void 3035 _vdrop(struct vnode *vp, bool locked) 3036 { 3037 struct bufobj *bo; 3038 struct mount *mp; 3039 int active; 3040 3041 if (locked) 3042 ASSERT_VI_LOCKED(vp, __func__); 3043 else 3044 ASSERT_VI_UNLOCKED(vp, __func__); 3045 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3046 if ((int)vp->v_holdcnt <= 0) 3047 panic("vdrop: holdcnt %d", vp->v_holdcnt); 3048 if (!locked) { 3049 if (refcount_release_if_not_last(&vp->v_holdcnt)) 3050 return; 3051 VI_LOCK(vp); 3052 } 3053 if (refcount_release(&vp->v_holdcnt) == 0) { 3054 VI_UNLOCK(vp); 3055 return; 3056 } 3057 if ((vp->v_iflag & VI_DOOMED) == 0) { 3058 /* 3059 * Mark a vnode as free: remove it from its active list 3060 * and put it up for recycling on the freelist. 3061 */ 3062 VNASSERT(vp->v_op != NULL, vp, 3063 ("vdropl: vnode already reclaimed.")); 3064 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 3065 ("vnode already free")); 3066 VNASSERT(vp->v_holdcnt == 0, vp, 3067 ("vdropl: freeing when we shouldn't")); 3068 active = vp->v_iflag & VI_ACTIVE; 3069 if ((vp->v_iflag & VI_OWEINACT) == 0) { 3070 vp->v_iflag &= ~VI_ACTIVE; 3071 mp = vp->v_mount; 3072 if (mp != NULL) { 3073 mtx_lock(&mp->mnt_listmtx); 3074 if (active) { 3075 TAILQ_REMOVE(&mp->mnt_activevnodelist, 3076 vp, v_actfreelist); 3077 mp->mnt_activevnodelistsize--; 3078 } 3079 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, 3080 vp, v_actfreelist); 3081 mp->mnt_tmpfreevnodelistsize++; 3082 vp->v_iflag |= VI_FREE; 3083 vp->v_mflag |= VMP_TMPMNTFREELIST; 3084 VI_UNLOCK(vp); 3085 if (mp->mnt_tmpfreevnodelistsize >= 3086 mnt_free_list_batch) 3087 vnlru_return_batch_locked(mp); 3088 mtx_unlock(&mp->mnt_listmtx); 3089 } else { 3090 VNASSERT(active == 0, vp, 3091 ("vdropl: active vnode not on per mount " 3092 "vnode list")); 3093 mtx_lock(&vnode_free_list_mtx); 3094 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 3095 v_actfreelist); 3096 freevnodes++; 3097 vp->v_iflag |= VI_FREE; 3098 VI_UNLOCK(vp); 3099 mtx_unlock(&vnode_free_list_mtx); 3100 } 3101 } else { 3102 VI_UNLOCK(vp); 3103 counter_u64_add(free_owe_inact, 1); 3104 } 3105 return; 3106 } 3107 /* 3108 * The vnode has been marked for destruction, so free it. 3109 * 3110 * The vnode will be returned to the zone where it will 3111 * normally remain until it is needed for another vnode. We 3112 * need to cleanup (or verify that the cleanup has already 3113 * been done) any residual data left from its current use 3114 * so as not to contaminate the freshly allocated vnode. 3115 */ 3116 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 3117 atomic_subtract_long(&numvnodes, 1); 3118 bo = &vp->v_bufobj; 3119 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 3120 ("cleaned vnode still on the free list.")); 3121 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 3122 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 3123 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 3124 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 3125 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 3126 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 3127 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 3128 ("clean blk trie not empty")); 3129 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 3130 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 3131 ("dirty blk trie not empty")); 3132 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 3133 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 3134 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 3135 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 3136 ("Dangling rangelock waiters")); 3137 VI_UNLOCK(vp); 3138 #ifdef MAC 3139 mac_vnode_destroy(vp); 3140 #endif 3141 if (vp->v_pollinfo != NULL) { 3142 destroy_vpollinfo(vp->v_pollinfo); 3143 vp->v_pollinfo = NULL; 3144 } 3145 #ifdef INVARIANTS 3146 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 3147 vp->v_op = NULL; 3148 #endif 3149 vp->v_mountedhere = NULL; 3150 vp->v_unpcb = NULL; 3151 vp->v_rdev = NULL; 3152 vp->v_fifoinfo = NULL; 3153 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 3154 vp->v_iflag = 0; 3155 vp->v_vflag = 0; 3156 bo->bo_flag = 0; 3157 uma_zfree(vnode_zone, vp); 3158 } 3159 3160 /* 3161 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3162 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3163 * OWEINACT tracks whether a vnode missed a call to inactive due to a 3164 * failed lock upgrade. 3165 */ 3166 void 3167 vinactive(struct vnode *vp, struct thread *td) 3168 { 3169 struct vm_object *obj; 3170 3171 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3172 ASSERT_VI_LOCKED(vp, "vinactive"); 3173 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3174 ("vinactive: recursed on VI_DOINGINACT")); 3175 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3176 vp->v_iflag |= VI_DOINGINACT; 3177 vp->v_iflag &= ~VI_OWEINACT; 3178 VI_UNLOCK(vp); 3179 /* 3180 * Before moving off the active list, we must be sure that any 3181 * modified pages are converted into the vnode's dirty 3182 * buffers, since these will no longer be checked once the 3183 * vnode is on the inactive list. 3184 * 3185 * The write-out of the dirty pages is asynchronous. At the 3186 * point that VOP_INACTIVE() is called, there could still be 3187 * pending I/O and dirty pages in the object. 3188 */ 3189 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3190 (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { 3191 VM_OBJECT_WLOCK(obj); 3192 vm_object_page_clean(obj, 0, 0, 0); 3193 VM_OBJECT_WUNLOCK(obj); 3194 } 3195 VOP_INACTIVE(vp, td); 3196 VI_LOCK(vp); 3197 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3198 ("vinactive: lost VI_DOINGINACT")); 3199 vp->v_iflag &= ~VI_DOINGINACT; 3200 } 3201 3202 /* 3203 * Remove any vnodes in the vnode table belonging to mount point mp. 3204 * 3205 * If FORCECLOSE is not specified, there should not be any active ones, 3206 * return error if any are found (nb: this is a user error, not a 3207 * system error). If FORCECLOSE is specified, detach any active vnodes 3208 * that are found. 3209 * 3210 * If WRITECLOSE is set, only flush out regular file vnodes open for 3211 * writing. 3212 * 3213 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3214 * 3215 * `rootrefs' specifies the base reference count for the root vnode 3216 * of this filesystem. The root vnode is considered busy if its 3217 * v_usecount exceeds this value. On a successful return, vflush(, td) 3218 * will call vrele() on the root vnode exactly rootrefs times. 3219 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3220 * be zero. 3221 */ 3222 #ifdef DIAGNOSTIC 3223 static int busyprt = 0; /* print out busy vnodes */ 3224 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3225 #endif 3226 3227 int 3228 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3229 { 3230 struct vnode *vp, *mvp, *rootvp = NULL; 3231 struct vattr vattr; 3232 int busy = 0, error; 3233 3234 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3235 rootrefs, flags); 3236 if (rootrefs > 0) { 3237 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3238 ("vflush: bad args")); 3239 /* 3240 * Get the filesystem root vnode. We can vput() it 3241 * immediately, since with rootrefs > 0, it won't go away. 3242 */ 3243 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3244 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3245 __func__, error); 3246 return (error); 3247 } 3248 vput(rootvp); 3249 } 3250 loop: 3251 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3252 vholdl(vp); 3253 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3254 if (error) { 3255 vdrop(vp); 3256 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3257 goto loop; 3258 } 3259 /* 3260 * Skip over a vnodes marked VV_SYSTEM. 3261 */ 3262 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3263 VOP_UNLOCK(vp, 0); 3264 vdrop(vp); 3265 continue; 3266 } 3267 /* 3268 * If WRITECLOSE is set, flush out unlinked but still open 3269 * files (even if open only for reading) and regular file 3270 * vnodes open for writing. 3271 */ 3272 if (flags & WRITECLOSE) { 3273 if (vp->v_object != NULL) { 3274 VM_OBJECT_WLOCK(vp->v_object); 3275 vm_object_page_clean(vp->v_object, 0, 0, 0); 3276 VM_OBJECT_WUNLOCK(vp->v_object); 3277 } 3278 error = VOP_FSYNC(vp, MNT_WAIT, td); 3279 if (error != 0) { 3280 VOP_UNLOCK(vp, 0); 3281 vdrop(vp); 3282 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3283 return (error); 3284 } 3285 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3286 VI_LOCK(vp); 3287 3288 if ((vp->v_type == VNON || 3289 (error == 0 && vattr.va_nlink > 0)) && 3290 (vp->v_writecount <= 0 || vp->v_type != VREG)) { 3291 VOP_UNLOCK(vp, 0); 3292 vdropl(vp); 3293 continue; 3294 } 3295 } else 3296 VI_LOCK(vp); 3297 /* 3298 * With v_usecount == 0, all we need to do is clear out the 3299 * vnode data structures and we are done. 3300 * 3301 * If FORCECLOSE is set, forcibly close the vnode. 3302 */ 3303 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3304 vgonel(vp); 3305 } else { 3306 busy++; 3307 #ifdef DIAGNOSTIC 3308 if (busyprt) 3309 vn_printf(vp, "vflush: busy vnode "); 3310 #endif 3311 } 3312 VOP_UNLOCK(vp, 0); 3313 vdropl(vp); 3314 } 3315 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3316 /* 3317 * If just the root vnode is busy, and if its refcount 3318 * is equal to `rootrefs', then go ahead and kill it. 3319 */ 3320 VI_LOCK(rootvp); 3321 KASSERT(busy > 0, ("vflush: not busy")); 3322 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3323 ("vflush: usecount %d < rootrefs %d", 3324 rootvp->v_usecount, rootrefs)); 3325 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3326 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3327 vgone(rootvp); 3328 VOP_UNLOCK(rootvp, 0); 3329 busy = 0; 3330 } else 3331 VI_UNLOCK(rootvp); 3332 } 3333 if (busy) { 3334 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3335 busy); 3336 return (EBUSY); 3337 } 3338 for (; rootrefs > 0; rootrefs--) 3339 vrele(rootvp); 3340 return (0); 3341 } 3342 3343 /* 3344 * Recycle an unused vnode to the front of the free list. 3345 */ 3346 int 3347 vrecycle(struct vnode *vp) 3348 { 3349 int recycled; 3350 3351 VI_LOCK(vp); 3352 recycled = vrecyclel(vp); 3353 VI_UNLOCK(vp); 3354 return (recycled); 3355 } 3356 3357 /* 3358 * vrecycle, with the vp interlock held. 3359 */ 3360 int 3361 vrecyclel(struct vnode *vp) 3362 { 3363 int recycled; 3364 3365 ASSERT_VOP_ELOCKED(vp, __func__); 3366 ASSERT_VI_LOCKED(vp, __func__); 3367 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3368 recycled = 0; 3369 if (vp->v_usecount == 0) { 3370 recycled = 1; 3371 vgonel(vp); 3372 } 3373 return (recycled); 3374 } 3375 3376 /* 3377 * Eliminate all activity associated with a vnode 3378 * in preparation for reuse. 3379 */ 3380 void 3381 vgone(struct vnode *vp) 3382 { 3383 VI_LOCK(vp); 3384 vgonel(vp); 3385 VI_UNLOCK(vp); 3386 } 3387 3388 static void 3389 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3390 struct vnode *lowervp __unused) 3391 { 3392 } 3393 3394 /* 3395 * Notify upper mounts about reclaimed or unlinked vnode. 3396 */ 3397 void 3398 vfs_notify_upper(struct vnode *vp, int event) 3399 { 3400 static struct vfsops vgonel_vfsops = { 3401 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3402 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3403 }; 3404 struct mount *mp, *ump, *mmp; 3405 3406 mp = vp->v_mount; 3407 if (mp == NULL) 3408 return; 3409 3410 MNT_ILOCK(mp); 3411 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3412 goto unlock; 3413 MNT_IUNLOCK(mp); 3414 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3415 mmp->mnt_op = &vgonel_vfsops; 3416 mmp->mnt_kern_flag |= MNTK_MARKER; 3417 MNT_ILOCK(mp); 3418 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3419 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3420 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3421 ump = TAILQ_NEXT(ump, mnt_upper_link); 3422 continue; 3423 } 3424 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3425 MNT_IUNLOCK(mp); 3426 switch (event) { 3427 case VFS_NOTIFY_UPPER_RECLAIM: 3428 VFS_RECLAIM_LOWERVP(ump, vp); 3429 break; 3430 case VFS_NOTIFY_UPPER_UNLINK: 3431 VFS_UNLINK_LOWERVP(ump, vp); 3432 break; 3433 default: 3434 KASSERT(0, ("invalid event %d", event)); 3435 break; 3436 } 3437 MNT_ILOCK(mp); 3438 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3439 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3440 } 3441 free(mmp, M_TEMP); 3442 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3443 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3444 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3445 wakeup(&mp->mnt_uppers); 3446 } 3447 unlock: 3448 MNT_IUNLOCK(mp); 3449 } 3450 3451 /* 3452 * vgone, with the vp interlock held. 3453 */ 3454 static void 3455 vgonel(struct vnode *vp) 3456 { 3457 struct thread *td; 3458 int oweinact; 3459 int active; 3460 struct mount *mp; 3461 3462 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3463 ASSERT_VI_LOCKED(vp, "vgonel"); 3464 VNASSERT(vp->v_holdcnt, vp, 3465 ("vgonel: vp %p has no reference.", vp)); 3466 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3467 td = curthread; 3468 3469 /* 3470 * Don't vgonel if we're already doomed. 3471 */ 3472 if (vp->v_iflag & VI_DOOMED) 3473 return; 3474 vp->v_iflag |= VI_DOOMED; 3475 3476 /* 3477 * Check to see if the vnode is in use. If so, we have to call 3478 * VOP_CLOSE() and VOP_INACTIVE(). 3479 */ 3480 active = vp->v_usecount; 3481 oweinact = (vp->v_iflag & VI_OWEINACT); 3482 VI_UNLOCK(vp); 3483 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3484 3485 /* 3486 * If purging an active vnode, it must be closed and 3487 * deactivated before being reclaimed. 3488 */ 3489 if (active) 3490 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3491 if (oweinact || active) { 3492 VI_LOCK(vp); 3493 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3494 vinactive(vp, td); 3495 VI_UNLOCK(vp); 3496 } 3497 if (vp->v_type == VSOCK) 3498 vfs_unp_reclaim(vp); 3499 3500 /* 3501 * Clean out any buffers associated with the vnode. 3502 * If the flush fails, just toss the buffers. 3503 */ 3504 mp = NULL; 3505 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3506 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3507 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3508 while (vinvalbuf(vp, 0, 0, 0) != 0) 3509 ; 3510 } 3511 3512 BO_LOCK(&vp->v_bufobj); 3513 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3514 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3515 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3516 vp->v_bufobj.bo_clean.bv_cnt == 0, 3517 ("vp %p bufobj not invalidated", vp)); 3518 3519 /* 3520 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate() 3521 * after the object's page queue is flushed. 3522 */ 3523 if (vp->v_bufobj.bo_object == NULL) 3524 vp->v_bufobj.bo_flag |= BO_DEAD; 3525 BO_UNLOCK(&vp->v_bufobj); 3526 3527 /* 3528 * Reclaim the vnode. 3529 */ 3530 if (VOP_RECLAIM(vp, td)) 3531 panic("vgone: cannot reclaim"); 3532 if (mp != NULL) 3533 vn_finished_secondary_write(mp); 3534 VNASSERT(vp->v_object == NULL, vp, 3535 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3536 /* 3537 * Clear the advisory locks and wake up waiting threads. 3538 */ 3539 (void)VOP_ADVLOCKPURGE(vp); 3540 vp->v_lockf = NULL; 3541 /* 3542 * Delete from old mount point vnode list. 3543 */ 3544 delmntque(vp); 3545 cache_purge(vp); 3546 /* 3547 * Done with purge, reset to the standard lock and invalidate 3548 * the vnode. 3549 */ 3550 VI_LOCK(vp); 3551 vp->v_vnlock = &vp->v_lock; 3552 vp->v_op = &dead_vnodeops; 3553 vp->v_tag = "none"; 3554 vp->v_type = VBAD; 3555 } 3556 3557 /* 3558 * Calculate the total number of references to a special device. 3559 */ 3560 int 3561 vcount(struct vnode *vp) 3562 { 3563 int count; 3564 3565 dev_lock(); 3566 count = vp->v_rdev->si_usecount; 3567 dev_unlock(); 3568 return (count); 3569 } 3570 3571 /* 3572 * Same as above, but using the struct cdev *as argument 3573 */ 3574 int 3575 count_dev(struct cdev *dev) 3576 { 3577 int count; 3578 3579 dev_lock(); 3580 count = dev->si_usecount; 3581 dev_unlock(); 3582 return(count); 3583 } 3584 3585 /* 3586 * Print out a description of a vnode. 3587 */ 3588 static char *typename[] = 3589 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3590 "VMARKER"}; 3591 3592 void 3593 vn_printf(struct vnode *vp, const char *fmt, ...) 3594 { 3595 va_list ap; 3596 char buf[256], buf2[16]; 3597 u_long flags; 3598 3599 va_start(ap, fmt); 3600 vprintf(fmt, ap); 3601 va_end(ap); 3602 printf("%p: ", (void *)vp); 3603 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3604 printf(" usecount %d, writecount %d, refcount %d", 3605 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 3606 switch (vp->v_type) { 3607 case VDIR: 3608 printf(" mountedhere %p\n", vp->v_mountedhere); 3609 break; 3610 case VCHR: 3611 printf(" rdev %p\n", vp->v_rdev); 3612 break; 3613 case VSOCK: 3614 printf(" socket %p\n", vp->v_unpcb); 3615 break; 3616 case VFIFO: 3617 printf(" fifoinfo %p\n", vp->v_fifoinfo); 3618 break; 3619 default: 3620 printf("\n"); 3621 break; 3622 } 3623 buf[0] = '\0'; 3624 buf[1] = '\0'; 3625 if (vp->v_vflag & VV_ROOT) 3626 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3627 if (vp->v_vflag & VV_ISTTY) 3628 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3629 if (vp->v_vflag & VV_NOSYNC) 3630 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3631 if (vp->v_vflag & VV_ETERNALDEV) 3632 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3633 if (vp->v_vflag & VV_CACHEDLABEL) 3634 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3635 if (vp->v_vflag & VV_COPYONWRITE) 3636 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3637 if (vp->v_vflag & VV_SYSTEM) 3638 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3639 if (vp->v_vflag & VV_PROCDEP) 3640 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3641 if (vp->v_vflag & VV_NOKNOTE) 3642 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3643 if (vp->v_vflag & VV_DELETED) 3644 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3645 if (vp->v_vflag & VV_MD) 3646 strlcat(buf, "|VV_MD", sizeof(buf)); 3647 if (vp->v_vflag & VV_FORCEINSMQ) 3648 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3649 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3650 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3651 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3652 if (flags != 0) { 3653 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3654 strlcat(buf, buf2, sizeof(buf)); 3655 } 3656 if (vp->v_iflag & VI_MOUNT) 3657 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3658 if (vp->v_iflag & VI_DOOMED) 3659 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 3660 if (vp->v_iflag & VI_FREE) 3661 strlcat(buf, "|VI_FREE", sizeof(buf)); 3662 if (vp->v_iflag & VI_ACTIVE) 3663 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3664 if (vp->v_iflag & VI_DOINGINACT) 3665 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3666 if (vp->v_iflag & VI_OWEINACT) 3667 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3668 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | 3669 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT); 3670 if (flags != 0) { 3671 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3672 strlcat(buf, buf2, sizeof(buf)); 3673 } 3674 printf(" flags (%s)\n", buf + 1); 3675 if (mtx_owned(VI_MTX(vp))) 3676 printf(" VI_LOCKed"); 3677 if (vp->v_object != NULL) 3678 printf(" v_object %p ref %d pages %d " 3679 "cleanbuf %d dirtybuf %d\n", 3680 vp->v_object, vp->v_object->ref_count, 3681 vp->v_object->resident_page_count, 3682 vp->v_bufobj.bo_clean.bv_cnt, 3683 vp->v_bufobj.bo_dirty.bv_cnt); 3684 printf(" "); 3685 lockmgr_printinfo(vp->v_vnlock); 3686 if (vp->v_data != NULL) 3687 VOP_PRINT(vp); 3688 } 3689 3690 #ifdef DDB 3691 /* 3692 * List all of the locked vnodes in the system. 3693 * Called when debugging the kernel. 3694 */ 3695 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3696 { 3697 struct mount *mp; 3698 struct vnode *vp; 3699 3700 /* 3701 * Note: because this is DDB, we can't obey the locking semantics 3702 * for these structures, which means we could catch an inconsistent 3703 * state and dereference a nasty pointer. Not much to be done 3704 * about that. 3705 */ 3706 db_printf("Locked vnodes\n"); 3707 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3708 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3709 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3710 vn_printf(vp, "vnode "); 3711 } 3712 } 3713 } 3714 3715 /* 3716 * Show details about the given vnode. 3717 */ 3718 DB_SHOW_COMMAND(vnode, db_show_vnode) 3719 { 3720 struct vnode *vp; 3721 3722 if (!have_addr) 3723 return; 3724 vp = (struct vnode *)addr; 3725 vn_printf(vp, "vnode "); 3726 } 3727 3728 /* 3729 * Show details about the given mount point. 3730 */ 3731 DB_SHOW_COMMAND(mount, db_show_mount) 3732 { 3733 struct mount *mp; 3734 struct vfsopt *opt; 3735 struct statfs *sp; 3736 struct vnode *vp; 3737 char buf[512]; 3738 uint64_t mflags; 3739 u_int flags; 3740 3741 if (!have_addr) { 3742 /* No address given, print short info about all mount points. */ 3743 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3744 db_printf("%p %s on %s (%s)\n", mp, 3745 mp->mnt_stat.f_mntfromname, 3746 mp->mnt_stat.f_mntonname, 3747 mp->mnt_stat.f_fstypename); 3748 if (db_pager_quit) 3749 break; 3750 } 3751 db_printf("\nMore info: show mount <addr>\n"); 3752 return; 3753 } 3754 3755 mp = (struct mount *)addr; 3756 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3757 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3758 3759 buf[0] = '\0'; 3760 mflags = mp->mnt_flag; 3761 #define MNT_FLAG(flag) do { \ 3762 if (mflags & (flag)) { \ 3763 if (buf[0] != '\0') \ 3764 strlcat(buf, ", ", sizeof(buf)); \ 3765 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3766 mflags &= ~(flag); \ 3767 } \ 3768 } while (0) 3769 MNT_FLAG(MNT_RDONLY); 3770 MNT_FLAG(MNT_SYNCHRONOUS); 3771 MNT_FLAG(MNT_NOEXEC); 3772 MNT_FLAG(MNT_NOSUID); 3773 MNT_FLAG(MNT_NFS4ACLS); 3774 MNT_FLAG(MNT_UNION); 3775 MNT_FLAG(MNT_ASYNC); 3776 MNT_FLAG(MNT_SUIDDIR); 3777 MNT_FLAG(MNT_SOFTDEP); 3778 MNT_FLAG(MNT_NOSYMFOLLOW); 3779 MNT_FLAG(MNT_GJOURNAL); 3780 MNT_FLAG(MNT_MULTILABEL); 3781 MNT_FLAG(MNT_ACLS); 3782 MNT_FLAG(MNT_NOATIME); 3783 MNT_FLAG(MNT_NOCLUSTERR); 3784 MNT_FLAG(MNT_NOCLUSTERW); 3785 MNT_FLAG(MNT_SUJ); 3786 MNT_FLAG(MNT_EXRDONLY); 3787 MNT_FLAG(MNT_EXPORTED); 3788 MNT_FLAG(MNT_DEFEXPORTED); 3789 MNT_FLAG(MNT_EXPORTANON); 3790 MNT_FLAG(MNT_EXKERB); 3791 MNT_FLAG(MNT_EXPUBLIC); 3792 MNT_FLAG(MNT_LOCAL); 3793 MNT_FLAG(MNT_QUOTA); 3794 MNT_FLAG(MNT_ROOTFS); 3795 MNT_FLAG(MNT_USER); 3796 MNT_FLAG(MNT_IGNORE); 3797 MNT_FLAG(MNT_UPDATE); 3798 MNT_FLAG(MNT_DELEXPORT); 3799 MNT_FLAG(MNT_RELOAD); 3800 MNT_FLAG(MNT_FORCE); 3801 MNT_FLAG(MNT_SNAPSHOT); 3802 MNT_FLAG(MNT_BYFSID); 3803 #undef MNT_FLAG 3804 if (mflags != 0) { 3805 if (buf[0] != '\0') 3806 strlcat(buf, ", ", sizeof(buf)); 3807 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3808 "0x%016jx", mflags); 3809 } 3810 db_printf(" mnt_flag = %s\n", buf); 3811 3812 buf[0] = '\0'; 3813 flags = mp->mnt_kern_flag; 3814 #define MNT_KERN_FLAG(flag) do { \ 3815 if (flags & (flag)) { \ 3816 if (buf[0] != '\0') \ 3817 strlcat(buf, ", ", sizeof(buf)); \ 3818 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3819 flags &= ~(flag); \ 3820 } \ 3821 } while (0) 3822 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3823 MNT_KERN_FLAG(MNTK_ASYNC); 3824 MNT_KERN_FLAG(MNTK_SOFTDEP); 3825 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 3826 MNT_KERN_FLAG(MNTK_DRAINING); 3827 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3828 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3829 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3830 MNT_KERN_FLAG(MNTK_NO_IOPF); 3831 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3832 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3833 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3834 MNT_KERN_FLAG(MNTK_MARKER); 3835 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3836 MNT_KERN_FLAG(MNTK_NOASYNC); 3837 MNT_KERN_FLAG(MNTK_UNMOUNT); 3838 MNT_KERN_FLAG(MNTK_MWAIT); 3839 MNT_KERN_FLAG(MNTK_SUSPEND); 3840 MNT_KERN_FLAG(MNTK_SUSPEND2); 3841 MNT_KERN_FLAG(MNTK_SUSPENDED); 3842 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3843 MNT_KERN_FLAG(MNTK_NOKNOTE); 3844 #undef MNT_KERN_FLAG 3845 if (flags != 0) { 3846 if (buf[0] != '\0') 3847 strlcat(buf, ", ", sizeof(buf)); 3848 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3849 "0x%08x", flags); 3850 } 3851 db_printf(" mnt_kern_flag = %s\n", buf); 3852 3853 db_printf(" mnt_opt = "); 3854 opt = TAILQ_FIRST(mp->mnt_opt); 3855 if (opt != NULL) { 3856 db_printf("%s", opt->name); 3857 opt = TAILQ_NEXT(opt, link); 3858 while (opt != NULL) { 3859 db_printf(", %s", opt->name); 3860 opt = TAILQ_NEXT(opt, link); 3861 } 3862 } 3863 db_printf("\n"); 3864 3865 sp = &mp->mnt_stat; 3866 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3867 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3868 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3869 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3870 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3871 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 3872 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 3873 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 3874 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 3875 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 3876 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 3877 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 3878 3879 db_printf(" mnt_cred = { uid=%u ruid=%u", 3880 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 3881 if (jailed(mp->mnt_cred)) 3882 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 3883 db_printf(" }\n"); 3884 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 3885 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 3886 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 3887 db_printf(" mnt_activevnodelistsize = %d\n", 3888 mp->mnt_activevnodelistsize); 3889 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 3890 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 3891 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 3892 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 3893 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); 3894 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 3895 db_printf(" mnt_secondary_accwrites = %d\n", 3896 mp->mnt_secondary_accwrites); 3897 db_printf(" mnt_gjprovider = %s\n", 3898 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 3899 3900 db_printf("\n\nList of active vnodes\n"); 3901 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 3902 if (vp->v_type != VMARKER) { 3903 vn_printf(vp, "vnode "); 3904 if (db_pager_quit) 3905 break; 3906 } 3907 } 3908 db_printf("\n\nList of inactive vnodes\n"); 3909 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3910 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 3911 vn_printf(vp, "vnode "); 3912 if (db_pager_quit) 3913 break; 3914 } 3915 } 3916 } 3917 #endif /* DDB */ 3918 3919 /* 3920 * Fill in a struct xvfsconf based on a struct vfsconf. 3921 */ 3922 static int 3923 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 3924 { 3925 struct xvfsconf xvfsp; 3926 3927 bzero(&xvfsp, sizeof(xvfsp)); 3928 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3929 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3930 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3931 xvfsp.vfc_flags = vfsp->vfc_flags; 3932 /* 3933 * These are unused in userland, we keep them 3934 * to not break binary compatibility. 3935 */ 3936 xvfsp.vfc_vfsops = NULL; 3937 xvfsp.vfc_next = NULL; 3938 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3939 } 3940 3941 #ifdef COMPAT_FREEBSD32 3942 struct xvfsconf32 { 3943 uint32_t vfc_vfsops; 3944 char vfc_name[MFSNAMELEN]; 3945 int32_t vfc_typenum; 3946 int32_t vfc_refcount; 3947 int32_t vfc_flags; 3948 uint32_t vfc_next; 3949 }; 3950 3951 static int 3952 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 3953 { 3954 struct xvfsconf32 xvfsp; 3955 3956 bzero(&xvfsp, sizeof(xvfsp)); 3957 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3958 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3959 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3960 xvfsp.vfc_flags = vfsp->vfc_flags; 3961 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3962 } 3963 #endif 3964 3965 /* 3966 * Top level filesystem related information gathering. 3967 */ 3968 static int 3969 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3970 { 3971 struct vfsconf *vfsp; 3972 int error; 3973 3974 error = 0; 3975 vfsconf_slock(); 3976 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3977 #ifdef COMPAT_FREEBSD32 3978 if (req->flags & SCTL_MASK32) 3979 error = vfsconf2x32(req, vfsp); 3980 else 3981 #endif 3982 error = vfsconf2x(req, vfsp); 3983 if (error) 3984 break; 3985 } 3986 vfsconf_sunlock(); 3987 return (error); 3988 } 3989 3990 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 3991 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 3992 "S,xvfsconf", "List of all configured filesystems"); 3993 3994 #ifndef BURN_BRIDGES 3995 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3996 3997 static int 3998 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3999 { 4000 int *name = (int *)arg1 - 1; /* XXX */ 4001 u_int namelen = arg2 + 1; /* XXX */ 4002 struct vfsconf *vfsp; 4003 4004 log(LOG_WARNING, "userland calling deprecated sysctl, " 4005 "please rebuild world\n"); 4006 4007 #if 1 || defined(COMPAT_PRELITE2) 4008 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 4009 if (namelen == 1) 4010 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 4011 #endif 4012 4013 switch (name[1]) { 4014 case VFS_MAXTYPENUM: 4015 if (namelen != 2) 4016 return (ENOTDIR); 4017 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 4018 case VFS_CONF: 4019 if (namelen != 3) 4020 return (ENOTDIR); /* overloaded */ 4021 vfsconf_slock(); 4022 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4023 if (vfsp->vfc_typenum == name[2]) 4024 break; 4025 } 4026 vfsconf_sunlock(); 4027 if (vfsp == NULL) 4028 return (EOPNOTSUPP); 4029 #ifdef COMPAT_FREEBSD32 4030 if (req->flags & SCTL_MASK32) 4031 return (vfsconf2x32(req, vfsp)); 4032 else 4033 #endif 4034 return (vfsconf2x(req, vfsp)); 4035 } 4036 return (EOPNOTSUPP); 4037 } 4038 4039 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 4040 CTLFLAG_MPSAFE, vfs_sysctl, 4041 "Generic filesystem"); 4042 4043 #if 1 || defined(COMPAT_PRELITE2) 4044 4045 static int 4046 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 4047 { 4048 int error; 4049 struct vfsconf *vfsp; 4050 struct ovfsconf ovfs; 4051 4052 vfsconf_slock(); 4053 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 4054 bzero(&ovfs, sizeof(ovfs)); 4055 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 4056 strcpy(ovfs.vfc_name, vfsp->vfc_name); 4057 ovfs.vfc_index = vfsp->vfc_typenum; 4058 ovfs.vfc_refcount = vfsp->vfc_refcount; 4059 ovfs.vfc_flags = vfsp->vfc_flags; 4060 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 4061 if (error != 0) { 4062 vfsconf_sunlock(); 4063 return (error); 4064 } 4065 } 4066 vfsconf_sunlock(); 4067 return (0); 4068 } 4069 4070 #endif /* 1 || COMPAT_PRELITE2 */ 4071 #endif /* !BURN_BRIDGES */ 4072 4073 #define KINFO_VNODESLOP 10 4074 #ifdef notyet 4075 /* 4076 * Dump vnode list (via sysctl). 4077 */ 4078 /* ARGSUSED */ 4079 static int 4080 sysctl_vnode(SYSCTL_HANDLER_ARGS) 4081 { 4082 struct xvnode *xvn; 4083 struct mount *mp; 4084 struct vnode *vp; 4085 int error, len, n; 4086 4087 /* 4088 * Stale numvnodes access is not fatal here. 4089 */ 4090 req->lock = 0; 4091 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 4092 if (!req->oldptr) 4093 /* Make an estimate */ 4094 return (SYSCTL_OUT(req, 0, len)); 4095 4096 error = sysctl_wire_old_buffer(req, 0); 4097 if (error != 0) 4098 return (error); 4099 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 4100 n = 0; 4101 mtx_lock(&mountlist_mtx); 4102 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 4103 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 4104 continue; 4105 MNT_ILOCK(mp); 4106 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 4107 if (n == len) 4108 break; 4109 vref(vp); 4110 xvn[n].xv_size = sizeof *xvn; 4111 xvn[n].xv_vnode = vp; 4112 xvn[n].xv_id = 0; /* XXX compat */ 4113 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 4114 XV_COPY(usecount); 4115 XV_COPY(writecount); 4116 XV_COPY(holdcnt); 4117 XV_COPY(mount); 4118 XV_COPY(numoutput); 4119 XV_COPY(type); 4120 #undef XV_COPY 4121 xvn[n].xv_flag = vp->v_vflag; 4122 4123 switch (vp->v_type) { 4124 case VREG: 4125 case VDIR: 4126 case VLNK: 4127 break; 4128 case VBLK: 4129 case VCHR: 4130 if (vp->v_rdev == NULL) { 4131 vrele(vp); 4132 continue; 4133 } 4134 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4135 break; 4136 case VSOCK: 4137 xvn[n].xv_socket = vp->v_socket; 4138 break; 4139 case VFIFO: 4140 xvn[n].xv_fifo = vp->v_fifoinfo; 4141 break; 4142 case VNON: 4143 case VBAD: 4144 default: 4145 /* shouldn't happen? */ 4146 vrele(vp); 4147 continue; 4148 } 4149 vrele(vp); 4150 ++n; 4151 } 4152 MNT_IUNLOCK(mp); 4153 mtx_lock(&mountlist_mtx); 4154 vfs_unbusy(mp); 4155 if (n == len) 4156 break; 4157 } 4158 mtx_unlock(&mountlist_mtx); 4159 4160 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4161 free(xvn, M_TEMP); 4162 return (error); 4163 } 4164 4165 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4166 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4167 ""); 4168 #endif 4169 4170 static void 4171 unmount_or_warn(struct mount *mp) 4172 { 4173 int error; 4174 4175 error = dounmount(mp, MNT_FORCE, curthread); 4176 if (error != 0) { 4177 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4178 if (error == EBUSY) 4179 printf("BUSY)\n"); 4180 else 4181 printf("%d)\n", error); 4182 } 4183 } 4184 4185 /* 4186 * Unmount all filesystems. The list is traversed in reverse order 4187 * of mounting to avoid dependencies. 4188 */ 4189 void 4190 vfs_unmountall(void) 4191 { 4192 struct mount *mp, *tmp; 4193 4194 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4195 4196 /* 4197 * Since this only runs when rebooting, it is not interlocked. 4198 */ 4199 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4200 vfs_ref(mp); 4201 4202 /* 4203 * Forcibly unmounting "/dev" before "/" would prevent clean 4204 * unmount of the latter. 4205 */ 4206 if (mp == rootdevmp) 4207 continue; 4208 4209 unmount_or_warn(mp); 4210 } 4211 4212 if (rootdevmp != NULL) 4213 unmount_or_warn(rootdevmp); 4214 } 4215 4216 /* 4217 * perform msync on all vnodes under a mount point 4218 * the mount point must be locked. 4219 */ 4220 void 4221 vfs_msync(struct mount *mp, int flags) 4222 { 4223 struct vnode *vp, *mvp; 4224 struct vm_object *obj; 4225 4226 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4227 4228 vnlru_return_batch(mp); 4229 4230 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 4231 obj = vp->v_object; 4232 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 4233 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 4234 if (!vget(vp, 4235 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 4236 curthread)) { 4237 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 4238 vput(vp); 4239 continue; 4240 } 4241 4242 obj = vp->v_object; 4243 if (obj != NULL) { 4244 VM_OBJECT_WLOCK(obj); 4245 vm_object_page_clean(obj, 0, 0, 4246 flags == MNT_WAIT ? 4247 OBJPC_SYNC : OBJPC_NOSYNC); 4248 VM_OBJECT_WUNLOCK(obj); 4249 } 4250 vput(vp); 4251 } 4252 } else 4253 VI_UNLOCK(vp); 4254 } 4255 } 4256 4257 static void 4258 destroy_vpollinfo_free(struct vpollinfo *vi) 4259 { 4260 4261 knlist_destroy(&vi->vpi_selinfo.si_note); 4262 mtx_destroy(&vi->vpi_lock); 4263 uma_zfree(vnodepoll_zone, vi); 4264 } 4265 4266 static void 4267 destroy_vpollinfo(struct vpollinfo *vi) 4268 { 4269 4270 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4271 seldrain(&vi->vpi_selinfo); 4272 destroy_vpollinfo_free(vi); 4273 } 4274 4275 /* 4276 * Initialize per-vnode helper structure to hold poll-related state. 4277 */ 4278 void 4279 v_addpollinfo(struct vnode *vp) 4280 { 4281 struct vpollinfo *vi; 4282 4283 if (vp->v_pollinfo != NULL) 4284 return; 4285 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4286 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4287 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4288 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4289 VI_LOCK(vp); 4290 if (vp->v_pollinfo != NULL) { 4291 VI_UNLOCK(vp); 4292 destroy_vpollinfo_free(vi); 4293 return; 4294 } 4295 vp->v_pollinfo = vi; 4296 VI_UNLOCK(vp); 4297 } 4298 4299 /* 4300 * Record a process's interest in events which might happen to 4301 * a vnode. Because poll uses the historic select-style interface 4302 * internally, this routine serves as both the ``check for any 4303 * pending events'' and the ``record my interest in future events'' 4304 * functions. (These are done together, while the lock is held, 4305 * to avoid race conditions.) 4306 */ 4307 int 4308 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4309 { 4310 4311 v_addpollinfo(vp); 4312 mtx_lock(&vp->v_pollinfo->vpi_lock); 4313 if (vp->v_pollinfo->vpi_revents & events) { 4314 /* 4315 * This leaves events we are not interested 4316 * in available for the other process which 4317 * which presumably had requested them 4318 * (otherwise they would never have been 4319 * recorded). 4320 */ 4321 events &= vp->v_pollinfo->vpi_revents; 4322 vp->v_pollinfo->vpi_revents &= ~events; 4323 4324 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4325 return (events); 4326 } 4327 vp->v_pollinfo->vpi_events |= events; 4328 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4329 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4330 return (0); 4331 } 4332 4333 /* 4334 * Routine to create and manage a filesystem syncer vnode. 4335 */ 4336 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4337 static int sync_fsync(struct vop_fsync_args *); 4338 static int sync_inactive(struct vop_inactive_args *); 4339 static int sync_reclaim(struct vop_reclaim_args *); 4340 4341 static struct vop_vector sync_vnodeops = { 4342 .vop_bypass = VOP_EOPNOTSUPP, 4343 .vop_close = sync_close, /* close */ 4344 .vop_fsync = sync_fsync, /* fsync */ 4345 .vop_inactive = sync_inactive, /* inactive */ 4346 .vop_reclaim = sync_reclaim, /* reclaim */ 4347 .vop_lock1 = vop_stdlock, /* lock */ 4348 .vop_unlock = vop_stdunlock, /* unlock */ 4349 .vop_islocked = vop_stdislocked, /* islocked */ 4350 }; 4351 4352 /* 4353 * Create a new filesystem syncer vnode for the specified mount point. 4354 */ 4355 void 4356 vfs_allocate_syncvnode(struct mount *mp) 4357 { 4358 struct vnode *vp; 4359 struct bufobj *bo; 4360 static long start, incr, next; 4361 int error; 4362 4363 /* Allocate a new vnode */ 4364 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4365 if (error != 0) 4366 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4367 vp->v_type = VNON; 4368 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4369 vp->v_vflag |= VV_FORCEINSMQ; 4370 error = insmntque(vp, mp); 4371 if (error != 0) 4372 panic("vfs_allocate_syncvnode: insmntque() failed"); 4373 vp->v_vflag &= ~VV_FORCEINSMQ; 4374 VOP_UNLOCK(vp, 0); 4375 /* 4376 * Place the vnode onto the syncer worklist. We attempt to 4377 * scatter them about on the list so that they will go off 4378 * at evenly distributed times even if all the filesystems 4379 * are mounted at once. 4380 */ 4381 next += incr; 4382 if (next == 0 || next > syncer_maxdelay) { 4383 start /= 2; 4384 incr /= 2; 4385 if (start == 0) { 4386 start = syncer_maxdelay / 2; 4387 incr = syncer_maxdelay; 4388 } 4389 next = start; 4390 } 4391 bo = &vp->v_bufobj; 4392 BO_LOCK(bo); 4393 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4394 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4395 mtx_lock(&sync_mtx); 4396 sync_vnode_count++; 4397 if (mp->mnt_syncer == NULL) { 4398 mp->mnt_syncer = vp; 4399 vp = NULL; 4400 } 4401 mtx_unlock(&sync_mtx); 4402 BO_UNLOCK(bo); 4403 if (vp != NULL) { 4404 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4405 vgone(vp); 4406 vput(vp); 4407 } 4408 } 4409 4410 void 4411 vfs_deallocate_syncvnode(struct mount *mp) 4412 { 4413 struct vnode *vp; 4414 4415 mtx_lock(&sync_mtx); 4416 vp = mp->mnt_syncer; 4417 if (vp != NULL) 4418 mp->mnt_syncer = NULL; 4419 mtx_unlock(&sync_mtx); 4420 if (vp != NULL) 4421 vrele(vp); 4422 } 4423 4424 /* 4425 * Do a lazy sync of the filesystem. 4426 */ 4427 static int 4428 sync_fsync(struct vop_fsync_args *ap) 4429 { 4430 struct vnode *syncvp = ap->a_vp; 4431 struct mount *mp = syncvp->v_mount; 4432 int error, save; 4433 struct bufobj *bo; 4434 4435 /* 4436 * We only need to do something if this is a lazy evaluation. 4437 */ 4438 if (ap->a_waitfor != MNT_LAZY) 4439 return (0); 4440 4441 /* 4442 * Move ourselves to the back of the sync list. 4443 */ 4444 bo = &syncvp->v_bufobj; 4445 BO_LOCK(bo); 4446 vn_syncer_add_to_worklist(bo, syncdelay); 4447 BO_UNLOCK(bo); 4448 4449 /* 4450 * Walk the list of vnodes pushing all that are dirty and 4451 * not already on the sync list. 4452 */ 4453 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4454 return (0); 4455 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4456 vfs_unbusy(mp); 4457 return (0); 4458 } 4459 save = curthread_pflags_set(TDP_SYNCIO); 4460 vfs_msync(mp, MNT_NOWAIT); 4461 error = VFS_SYNC(mp, MNT_LAZY); 4462 curthread_pflags_restore(save); 4463 vn_finished_write(mp); 4464 vfs_unbusy(mp); 4465 return (error); 4466 } 4467 4468 /* 4469 * The syncer vnode is no referenced. 4470 */ 4471 static int 4472 sync_inactive(struct vop_inactive_args *ap) 4473 { 4474 4475 vgone(ap->a_vp); 4476 return (0); 4477 } 4478 4479 /* 4480 * The syncer vnode is no longer needed and is being decommissioned. 4481 * 4482 * Modifications to the worklist must be protected by sync_mtx. 4483 */ 4484 static int 4485 sync_reclaim(struct vop_reclaim_args *ap) 4486 { 4487 struct vnode *vp = ap->a_vp; 4488 struct bufobj *bo; 4489 4490 bo = &vp->v_bufobj; 4491 BO_LOCK(bo); 4492 mtx_lock(&sync_mtx); 4493 if (vp->v_mount->mnt_syncer == vp) 4494 vp->v_mount->mnt_syncer = NULL; 4495 if (bo->bo_flag & BO_ONWORKLST) { 4496 LIST_REMOVE(bo, bo_synclist); 4497 syncer_worklist_len--; 4498 sync_vnode_count--; 4499 bo->bo_flag &= ~BO_ONWORKLST; 4500 } 4501 mtx_unlock(&sync_mtx); 4502 BO_UNLOCK(bo); 4503 4504 return (0); 4505 } 4506 4507 /* 4508 * Check if vnode represents a disk device 4509 */ 4510 int 4511 vn_isdisk(struct vnode *vp, int *errp) 4512 { 4513 int error; 4514 4515 if (vp->v_type != VCHR) { 4516 error = ENOTBLK; 4517 goto out; 4518 } 4519 error = 0; 4520 dev_lock(); 4521 if (vp->v_rdev == NULL) 4522 error = ENXIO; 4523 else if (vp->v_rdev->si_devsw == NULL) 4524 error = ENXIO; 4525 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4526 error = ENOTBLK; 4527 dev_unlock(); 4528 out: 4529 if (errp != NULL) 4530 *errp = error; 4531 return (error == 0); 4532 } 4533 4534 /* 4535 * Common filesystem object access control check routine. Accepts a 4536 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4537 * and optional call-by-reference privused argument allowing vaccess() 4538 * to indicate to the caller whether privilege was used to satisfy the 4539 * request (obsoleted). Returns 0 on success, or an errno on failure. 4540 */ 4541 int 4542 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4543 accmode_t accmode, struct ucred *cred, int *privused) 4544 { 4545 accmode_t dac_granted; 4546 accmode_t priv_granted; 4547 4548 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4549 ("invalid bit in accmode")); 4550 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4551 ("VAPPEND without VWRITE")); 4552 4553 /* 4554 * Look for a normal, non-privileged way to access the file/directory 4555 * as requested. If it exists, go with that. 4556 */ 4557 4558 if (privused != NULL) 4559 *privused = 0; 4560 4561 dac_granted = 0; 4562 4563 /* Check the owner. */ 4564 if (cred->cr_uid == file_uid) { 4565 dac_granted |= VADMIN; 4566 if (file_mode & S_IXUSR) 4567 dac_granted |= VEXEC; 4568 if (file_mode & S_IRUSR) 4569 dac_granted |= VREAD; 4570 if (file_mode & S_IWUSR) 4571 dac_granted |= (VWRITE | VAPPEND); 4572 4573 if ((accmode & dac_granted) == accmode) 4574 return (0); 4575 4576 goto privcheck; 4577 } 4578 4579 /* Otherwise, check the groups (first match) */ 4580 if (groupmember(file_gid, cred)) { 4581 if (file_mode & S_IXGRP) 4582 dac_granted |= VEXEC; 4583 if (file_mode & S_IRGRP) 4584 dac_granted |= VREAD; 4585 if (file_mode & S_IWGRP) 4586 dac_granted |= (VWRITE | VAPPEND); 4587 4588 if ((accmode & dac_granted) == accmode) 4589 return (0); 4590 4591 goto privcheck; 4592 } 4593 4594 /* Otherwise, check everyone else. */ 4595 if (file_mode & S_IXOTH) 4596 dac_granted |= VEXEC; 4597 if (file_mode & S_IROTH) 4598 dac_granted |= VREAD; 4599 if (file_mode & S_IWOTH) 4600 dac_granted |= (VWRITE | VAPPEND); 4601 if ((accmode & dac_granted) == accmode) 4602 return (0); 4603 4604 privcheck: 4605 /* 4606 * Build a privilege mask to determine if the set of privileges 4607 * satisfies the requirements when combined with the granted mask 4608 * from above. For each privilege, if the privilege is required, 4609 * bitwise or the request type onto the priv_granted mask. 4610 */ 4611 priv_granted = 0; 4612 4613 if (type == VDIR) { 4614 /* 4615 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4616 * requests, instead of PRIV_VFS_EXEC. 4617 */ 4618 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4619 !priv_check_cred(cred, PRIV_VFS_LOOKUP)) 4620 priv_granted |= VEXEC; 4621 } else { 4622 /* 4623 * Ensure that at least one execute bit is on. Otherwise, 4624 * a privileged user will always succeed, and we don't want 4625 * this to happen unless the file really is executable. 4626 */ 4627 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4628 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4629 !priv_check_cred(cred, PRIV_VFS_EXEC)) 4630 priv_granted |= VEXEC; 4631 } 4632 4633 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4634 !priv_check_cred(cred, PRIV_VFS_READ)) 4635 priv_granted |= VREAD; 4636 4637 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4638 !priv_check_cred(cred, PRIV_VFS_WRITE)) 4639 priv_granted |= (VWRITE | VAPPEND); 4640 4641 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4642 !priv_check_cred(cred, PRIV_VFS_ADMIN)) 4643 priv_granted |= VADMIN; 4644 4645 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4646 /* XXX audit: privilege used */ 4647 if (privused != NULL) 4648 *privused = 1; 4649 return (0); 4650 } 4651 4652 return ((accmode & VADMIN) ? EPERM : EACCES); 4653 } 4654 4655 /* 4656 * Credential check based on process requesting service, and per-attribute 4657 * permissions. 4658 */ 4659 int 4660 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4661 struct thread *td, accmode_t accmode) 4662 { 4663 4664 /* 4665 * Kernel-invoked always succeeds. 4666 */ 4667 if (cred == NOCRED) 4668 return (0); 4669 4670 /* 4671 * Do not allow privileged processes in jail to directly manipulate 4672 * system attributes. 4673 */ 4674 switch (attrnamespace) { 4675 case EXTATTR_NAMESPACE_SYSTEM: 4676 /* Potentially should be: return (EPERM); */ 4677 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM)); 4678 case EXTATTR_NAMESPACE_USER: 4679 return (VOP_ACCESS(vp, accmode, cred, td)); 4680 default: 4681 return (EPERM); 4682 } 4683 } 4684 4685 #ifdef DEBUG_VFS_LOCKS 4686 /* 4687 * This only exists to suppress warnings from unlocked specfs accesses. It is 4688 * no longer ok to have an unlocked VFS. 4689 */ 4690 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4691 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4692 4693 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4694 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4695 "Drop into debugger on lock violation"); 4696 4697 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4698 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4699 0, "Check for interlock across VOPs"); 4700 4701 int vfs_badlock_print = 1; /* Print lock violations. */ 4702 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4703 0, "Print lock violations"); 4704 4705 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 4706 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 4707 0, "Print vnode details on lock violations"); 4708 4709 #ifdef KDB 4710 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4711 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4712 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4713 #endif 4714 4715 static void 4716 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4717 { 4718 4719 #ifdef KDB 4720 if (vfs_badlock_backtrace) 4721 kdb_backtrace(); 4722 #endif 4723 if (vfs_badlock_vnode) 4724 vn_printf(vp, "vnode "); 4725 if (vfs_badlock_print) 4726 printf("%s: %p %s\n", str, (void *)vp, msg); 4727 if (vfs_badlock_ddb) 4728 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4729 } 4730 4731 void 4732 assert_vi_locked(struct vnode *vp, const char *str) 4733 { 4734 4735 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4736 vfs_badlock("interlock is not locked but should be", str, vp); 4737 } 4738 4739 void 4740 assert_vi_unlocked(struct vnode *vp, const char *str) 4741 { 4742 4743 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4744 vfs_badlock("interlock is locked but should not be", str, vp); 4745 } 4746 4747 void 4748 assert_vop_locked(struct vnode *vp, const char *str) 4749 { 4750 int locked; 4751 4752 if (!IGNORE_LOCK(vp)) { 4753 locked = VOP_ISLOCKED(vp); 4754 if (locked == 0 || locked == LK_EXCLOTHER) 4755 vfs_badlock("is not locked but should be", str, vp); 4756 } 4757 } 4758 4759 void 4760 assert_vop_unlocked(struct vnode *vp, const char *str) 4761 { 4762 4763 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4764 vfs_badlock("is locked but should not be", str, vp); 4765 } 4766 4767 void 4768 assert_vop_elocked(struct vnode *vp, const char *str) 4769 { 4770 4771 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4772 vfs_badlock("is not exclusive locked but should be", str, vp); 4773 } 4774 #endif /* DEBUG_VFS_LOCKS */ 4775 4776 void 4777 vop_rename_fail(struct vop_rename_args *ap) 4778 { 4779 4780 if (ap->a_tvp != NULL) 4781 vput(ap->a_tvp); 4782 if (ap->a_tdvp == ap->a_tvp) 4783 vrele(ap->a_tdvp); 4784 else 4785 vput(ap->a_tdvp); 4786 vrele(ap->a_fdvp); 4787 vrele(ap->a_fvp); 4788 } 4789 4790 void 4791 vop_rename_pre(void *ap) 4792 { 4793 struct vop_rename_args *a = ap; 4794 4795 #ifdef DEBUG_VFS_LOCKS 4796 if (a->a_tvp) 4797 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4798 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4799 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4800 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4801 4802 /* Check the source (from). */ 4803 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4804 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4805 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4806 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4807 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4808 4809 /* Check the target. */ 4810 if (a->a_tvp) 4811 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4812 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4813 #endif 4814 if (a->a_tdvp != a->a_fdvp) 4815 vhold(a->a_fdvp); 4816 if (a->a_tvp != a->a_fvp) 4817 vhold(a->a_fvp); 4818 vhold(a->a_tdvp); 4819 if (a->a_tvp) 4820 vhold(a->a_tvp); 4821 } 4822 4823 #ifdef DEBUG_VFS_LOCKS 4824 void 4825 vop_strategy_pre(void *ap) 4826 { 4827 struct vop_strategy_args *a; 4828 struct buf *bp; 4829 4830 a = ap; 4831 bp = a->a_bp; 4832 4833 /* 4834 * Cluster ops lock their component buffers but not the IO container. 4835 */ 4836 if ((bp->b_flags & B_CLUSTER) != 0) 4837 return; 4838 4839 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4840 if (vfs_badlock_print) 4841 printf( 4842 "VOP_STRATEGY: bp is not locked but should be\n"); 4843 if (vfs_badlock_ddb) 4844 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4845 } 4846 } 4847 4848 void 4849 vop_lock_pre(void *ap) 4850 { 4851 struct vop_lock1_args *a = ap; 4852 4853 if ((a->a_flags & LK_INTERLOCK) == 0) 4854 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4855 else 4856 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 4857 } 4858 4859 void 4860 vop_lock_post(void *ap, int rc) 4861 { 4862 struct vop_lock1_args *a = ap; 4863 4864 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4865 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 4866 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 4867 } 4868 4869 void 4870 vop_unlock_pre(void *ap) 4871 { 4872 struct vop_unlock_args *a = ap; 4873 4874 if (a->a_flags & LK_INTERLOCK) 4875 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4876 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4877 } 4878 4879 void 4880 vop_unlock_post(void *ap, int rc) 4881 { 4882 struct vop_unlock_args *a = ap; 4883 4884 if (a->a_flags & LK_INTERLOCK) 4885 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4886 } 4887 #endif 4888 4889 void 4890 vop_create_post(void *ap, int rc) 4891 { 4892 struct vop_create_args *a = ap; 4893 4894 if (!rc) 4895 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4896 } 4897 4898 void 4899 vop_deleteextattr_post(void *ap, int rc) 4900 { 4901 struct vop_deleteextattr_args *a = ap; 4902 4903 if (!rc) 4904 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4905 } 4906 4907 void 4908 vop_link_post(void *ap, int rc) 4909 { 4910 struct vop_link_args *a = ap; 4911 4912 if (!rc) { 4913 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4914 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4915 } 4916 } 4917 4918 void 4919 vop_mkdir_post(void *ap, int rc) 4920 { 4921 struct vop_mkdir_args *a = ap; 4922 4923 if (!rc) 4924 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4925 } 4926 4927 void 4928 vop_mknod_post(void *ap, int rc) 4929 { 4930 struct vop_mknod_args *a = ap; 4931 4932 if (!rc) 4933 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4934 } 4935 4936 void 4937 vop_reclaim_post(void *ap, int rc) 4938 { 4939 struct vop_reclaim_args *a = ap; 4940 4941 if (!rc) 4942 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 4943 } 4944 4945 void 4946 vop_remove_post(void *ap, int rc) 4947 { 4948 struct vop_remove_args *a = ap; 4949 4950 if (!rc) { 4951 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4952 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4953 } 4954 } 4955 4956 void 4957 vop_rename_post(void *ap, int rc) 4958 { 4959 struct vop_rename_args *a = ap; 4960 long hint; 4961 4962 if (!rc) { 4963 hint = NOTE_WRITE; 4964 if (a->a_fdvp == a->a_tdvp) { 4965 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 4966 hint |= NOTE_LINK; 4967 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4968 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4969 } else { 4970 hint |= NOTE_EXTEND; 4971 if (a->a_fvp->v_type == VDIR) 4972 hint |= NOTE_LINK; 4973 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4974 4975 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 4976 a->a_tvp->v_type == VDIR) 4977 hint &= ~NOTE_LINK; 4978 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4979 } 4980 4981 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4982 if (a->a_tvp) 4983 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4984 } 4985 if (a->a_tdvp != a->a_fdvp) 4986 vdrop(a->a_fdvp); 4987 if (a->a_tvp != a->a_fvp) 4988 vdrop(a->a_fvp); 4989 vdrop(a->a_tdvp); 4990 if (a->a_tvp) 4991 vdrop(a->a_tvp); 4992 } 4993 4994 void 4995 vop_rmdir_post(void *ap, int rc) 4996 { 4997 struct vop_rmdir_args *a = ap; 4998 4999 if (!rc) { 5000 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 5001 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 5002 } 5003 } 5004 5005 void 5006 vop_setattr_post(void *ap, int rc) 5007 { 5008 struct vop_setattr_args *a = ap; 5009 5010 if (!rc) 5011 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5012 } 5013 5014 void 5015 vop_setextattr_post(void *ap, int rc) 5016 { 5017 struct vop_setextattr_args *a = ap; 5018 5019 if (!rc) 5020 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 5021 } 5022 5023 void 5024 vop_symlink_post(void *ap, int rc) 5025 { 5026 struct vop_symlink_args *a = ap; 5027 5028 if (!rc) 5029 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 5030 } 5031 5032 void 5033 vop_open_post(void *ap, int rc) 5034 { 5035 struct vop_open_args *a = ap; 5036 5037 if (!rc) 5038 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 5039 } 5040 5041 void 5042 vop_close_post(void *ap, int rc) 5043 { 5044 struct vop_close_args *a = ap; 5045 5046 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 5047 (a->a_vp->v_iflag & VI_DOOMED) == 0)) { 5048 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 5049 NOTE_CLOSE_WRITE : NOTE_CLOSE); 5050 } 5051 } 5052 5053 void 5054 vop_read_post(void *ap, int rc) 5055 { 5056 struct vop_read_args *a = ap; 5057 5058 if (!rc) 5059 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5060 } 5061 5062 void 5063 vop_readdir_post(void *ap, int rc) 5064 { 5065 struct vop_readdir_args *a = ap; 5066 5067 if (!rc) 5068 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 5069 } 5070 5071 static struct knlist fs_knlist; 5072 5073 static void 5074 vfs_event_init(void *arg) 5075 { 5076 knlist_init_mtx(&fs_knlist, NULL); 5077 } 5078 /* XXX - correct order? */ 5079 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 5080 5081 void 5082 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 5083 { 5084 5085 KNOTE_UNLOCKED(&fs_knlist, event); 5086 } 5087 5088 static int filt_fsattach(struct knote *kn); 5089 static void filt_fsdetach(struct knote *kn); 5090 static int filt_fsevent(struct knote *kn, long hint); 5091 5092 struct filterops fs_filtops = { 5093 .f_isfd = 0, 5094 .f_attach = filt_fsattach, 5095 .f_detach = filt_fsdetach, 5096 .f_event = filt_fsevent 5097 }; 5098 5099 static int 5100 filt_fsattach(struct knote *kn) 5101 { 5102 5103 kn->kn_flags |= EV_CLEAR; 5104 knlist_add(&fs_knlist, kn, 0); 5105 return (0); 5106 } 5107 5108 static void 5109 filt_fsdetach(struct knote *kn) 5110 { 5111 5112 knlist_remove(&fs_knlist, kn, 0); 5113 } 5114 5115 static int 5116 filt_fsevent(struct knote *kn, long hint) 5117 { 5118 5119 kn->kn_fflags |= hint; 5120 return (kn->kn_fflags != 0); 5121 } 5122 5123 static int 5124 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 5125 { 5126 struct vfsidctl vc; 5127 int error; 5128 struct mount *mp; 5129 5130 error = SYSCTL_IN(req, &vc, sizeof(vc)); 5131 if (error) 5132 return (error); 5133 if (vc.vc_vers != VFS_CTL_VERS1) 5134 return (EINVAL); 5135 mp = vfs_getvfs(&vc.vc_fsid); 5136 if (mp == NULL) 5137 return (ENOENT); 5138 /* ensure that a specific sysctl goes to the right filesystem. */ 5139 if (strcmp(vc.vc_fstypename, "*") != 0 && 5140 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5141 vfs_rel(mp); 5142 return (EINVAL); 5143 } 5144 VCTLTOREQ(&vc, req); 5145 error = VFS_SYSCTL(mp, vc.vc_op, req); 5146 vfs_rel(mp); 5147 return (error); 5148 } 5149 5150 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 5151 NULL, 0, sysctl_vfs_ctl, "", 5152 "Sysctl by fsid"); 5153 5154 /* 5155 * Function to initialize a va_filerev field sensibly. 5156 * XXX: Wouldn't a random number make a lot more sense ?? 5157 */ 5158 u_quad_t 5159 init_va_filerev(void) 5160 { 5161 struct bintime bt; 5162 5163 getbinuptime(&bt); 5164 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5165 } 5166 5167 static int filt_vfsread(struct knote *kn, long hint); 5168 static int filt_vfswrite(struct knote *kn, long hint); 5169 static int filt_vfsvnode(struct knote *kn, long hint); 5170 static void filt_vfsdetach(struct knote *kn); 5171 static struct filterops vfsread_filtops = { 5172 .f_isfd = 1, 5173 .f_detach = filt_vfsdetach, 5174 .f_event = filt_vfsread 5175 }; 5176 static struct filterops vfswrite_filtops = { 5177 .f_isfd = 1, 5178 .f_detach = filt_vfsdetach, 5179 .f_event = filt_vfswrite 5180 }; 5181 static struct filterops vfsvnode_filtops = { 5182 .f_isfd = 1, 5183 .f_detach = filt_vfsdetach, 5184 .f_event = filt_vfsvnode 5185 }; 5186 5187 static void 5188 vfs_knllock(void *arg) 5189 { 5190 struct vnode *vp = arg; 5191 5192 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5193 } 5194 5195 static void 5196 vfs_knlunlock(void *arg) 5197 { 5198 struct vnode *vp = arg; 5199 5200 VOP_UNLOCK(vp, 0); 5201 } 5202 5203 static void 5204 vfs_knl_assert_locked(void *arg) 5205 { 5206 #ifdef DEBUG_VFS_LOCKS 5207 struct vnode *vp = arg; 5208 5209 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5210 #endif 5211 } 5212 5213 static void 5214 vfs_knl_assert_unlocked(void *arg) 5215 { 5216 #ifdef DEBUG_VFS_LOCKS 5217 struct vnode *vp = arg; 5218 5219 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5220 #endif 5221 } 5222 5223 int 5224 vfs_kqfilter(struct vop_kqfilter_args *ap) 5225 { 5226 struct vnode *vp = ap->a_vp; 5227 struct knote *kn = ap->a_kn; 5228 struct knlist *knl; 5229 5230 switch (kn->kn_filter) { 5231 case EVFILT_READ: 5232 kn->kn_fop = &vfsread_filtops; 5233 break; 5234 case EVFILT_WRITE: 5235 kn->kn_fop = &vfswrite_filtops; 5236 break; 5237 case EVFILT_VNODE: 5238 kn->kn_fop = &vfsvnode_filtops; 5239 break; 5240 default: 5241 return (EINVAL); 5242 } 5243 5244 kn->kn_hook = (caddr_t)vp; 5245 5246 v_addpollinfo(vp); 5247 if (vp->v_pollinfo == NULL) 5248 return (ENOMEM); 5249 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5250 vhold(vp); 5251 knlist_add(knl, kn, 0); 5252 5253 return (0); 5254 } 5255 5256 /* 5257 * Detach knote from vnode 5258 */ 5259 static void 5260 filt_vfsdetach(struct knote *kn) 5261 { 5262 struct vnode *vp = (struct vnode *)kn->kn_hook; 5263 5264 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5265 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5266 vdrop(vp); 5267 } 5268 5269 /*ARGSUSED*/ 5270 static int 5271 filt_vfsread(struct knote *kn, long hint) 5272 { 5273 struct vnode *vp = (struct vnode *)kn->kn_hook; 5274 struct vattr va; 5275 int res; 5276 5277 /* 5278 * filesystem is gone, so set the EOF flag and schedule 5279 * the knote for deletion. 5280 */ 5281 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5282 VI_LOCK(vp); 5283 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5284 VI_UNLOCK(vp); 5285 return (1); 5286 } 5287 5288 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5289 return (0); 5290 5291 VI_LOCK(vp); 5292 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5293 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5294 VI_UNLOCK(vp); 5295 return (res); 5296 } 5297 5298 /*ARGSUSED*/ 5299 static int 5300 filt_vfswrite(struct knote *kn, long hint) 5301 { 5302 struct vnode *vp = (struct vnode *)kn->kn_hook; 5303 5304 VI_LOCK(vp); 5305 5306 /* 5307 * filesystem is gone, so set the EOF flag and schedule 5308 * the knote for deletion. 5309 */ 5310 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5311 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5312 5313 kn->kn_data = 0; 5314 VI_UNLOCK(vp); 5315 return (1); 5316 } 5317 5318 static int 5319 filt_vfsvnode(struct knote *kn, long hint) 5320 { 5321 struct vnode *vp = (struct vnode *)kn->kn_hook; 5322 int res; 5323 5324 VI_LOCK(vp); 5325 if (kn->kn_sfflags & hint) 5326 kn->kn_fflags |= hint; 5327 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5328 kn->kn_flags |= EV_EOF; 5329 VI_UNLOCK(vp); 5330 return (1); 5331 } 5332 res = (kn->kn_fflags != 0); 5333 VI_UNLOCK(vp); 5334 return (res); 5335 } 5336 5337 int 5338 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5339 { 5340 int error; 5341 5342 if (dp->d_reclen > ap->a_uio->uio_resid) 5343 return (ENAMETOOLONG); 5344 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5345 if (error) { 5346 if (ap->a_ncookies != NULL) { 5347 if (ap->a_cookies != NULL) 5348 free(ap->a_cookies, M_TEMP); 5349 ap->a_cookies = NULL; 5350 *ap->a_ncookies = 0; 5351 } 5352 return (error); 5353 } 5354 if (ap->a_ncookies == NULL) 5355 return (0); 5356 5357 KASSERT(ap->a_cookies, 5358 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5359 5360 *ap->a_cookies = realloc(*ap->a_cookies, 5361 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5362 (*ap->a_cookies)[*ap->a_ncookies] = off; 5363 *ap->a_ncookies += 1; 5364 return (0); 5365 } 5366 5367 /* 5368 * Mark for update the access time of the file if the filesystem 5369 * supports VOP_MARKATIME. This functionality is used by execve and 5370 * mmap, so we want to avoid the I/O implied by directly setting 5371 * va_atime for the sake of efficiency. 5372 */ 5373 void 5374 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5375 { 5376 struct mount *mp; 5377 5378 mp = vp->v_mount; 5379 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5380 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5381 (void)VOP_MARKATIME(vp); 5382 } 5383 5384 /* 5385 * The purpose of this routine is to remove granularity from accmode_t, 5386 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5387 * VADMIN and VAPPEND. 5388 * 5389 * If it returns 0, the caller is supposed to continue with the usual 5390 * access checks using 'accmode' as modified by this routine. If it 5391 * returns nonzero value, the caller is supposed to return that value 5392 * as errno. 5393 * 5394 * Note that after this routine runs, accmode may be zero. 5395 */ 5396 int 5397 vfs_unixify_accmode(accmode_t *accmode) 5398 { 5399 /* 5400 * There is no way to specify explicit "deny" rule using 5401 * file mode or POSIX.1e ACLs. 5402 */ 5403 if (*accmode & VEXPLICIT_DENY) { 5404 *accmode = 0; 5405 return (0); 5406 } 5407 5408 /* 5409 * None of these can be translated into usual access bits. 5410 * Also, the common case for NFSv4 ACLs is to not contain 5411 * either of these bits. Caller should check for VWRITE 5412 * on the containing directory instead. 5413 */ 5414 if (*accmode & (VDELETE_CHILD | VDELETE)) 5415 return (EPERM); 5416 5417 if (*accmode & VADMIN_PERMS) { 5418 *accmode &= ~VADMIN_PERMS; 5419 *accmode |= VADMIN; 5420 } 5421 5422 /* 5423 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 5424 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 5425 */ 5426 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 5427 5428 return (0); 5429 } 5430 5431 /* 5432 * These are helper functions for filesystems to traverse all 5433 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 5434 * 5435 * This interface replaces MNT_VNODE_FOREACH. 5436 */ 5437 5438 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 5439 5440 struct vnode * 5441 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5442 { 5443 struct vnode *vp; 5444 5445 if (should_yield()) 5446 kern_yield(PRI_USER); 5447 MNT_ILOCK(mp); 5448 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5449 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 5450 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 5451 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5452 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5453 continue; 5454 VI_LOCK(vp); 5455 if ((vp->v_iflag & VI_DOOMED) != 0) { 5456 VI_UNLOCK(vp); 5457 continue; 5458 } 5459 break; 5460 } 5461 if (vp == NULL) { 5462 __mnt_vnode_markerfree_all(mvp, mp); 5463 /* MNT_IUNLOCK(mp); -- done in above function */ 5464 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5465 return (NULL); 5466 } 5467 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5468 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5469 MNT_IUNLOCK(mp); 5470 return (vp); 5471 } 5472 5473 struct vnode * 5474 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5475 { 5476 struct vnode *vp; 5477 5478 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5479 MNT_ILOCK(mp); 5480 MNT_REF(mp); 5481 (*mvp)->v_mount = mp; 5482 (*mvp)->v_type = VMARKER; 5483 5484 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 5485 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5486 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5487 continue; 5488 VI_LOCK(vp); 5489 if ((vp->v_iflag & VI_DOOMED) != 0) { 5490 VI_UNLOCK(vp); 5491 continue; 5492 } 5493 break; 5494 } 5495 if (vp == NULL) { 5496 MNT_REL(mp); 5497 MNT_IUNLOCK(mp); 5498 free(*mvp, M_VNODE_MARKER); 5499 *mvp = NULL; 5500 return (NULL); 5501 } 5502 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5503 MNT_IUNLOCK(mp); 5504 return (vp); 5505 } 5506 5507 void 5508 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5509 { 5510 5511 if (*mvp == NULL) { 5512 MNT_IUNLOCK(mp); 5513 return; 5514 } 5515 5516 mtx_assert(MNT_MTX(mp), MA_OWNED); 5517 5518 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5519 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5520 MNT_REL(mp); 5521 MNT_IUNLOCK(mp); 5522 free(*mvp, M_VNODE_MARKER); 5523 *mvp = NULL; 5524 } 5525 5526 /* 5527 * These are helper functions for filesystems to traverse their 5528 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5529 */ 5530 static void 5531 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5532 { 5533 5534 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5535 5536 MNT_ILOCK(mp); 5537 MNT_REL(mp); 5538 MNT_IUNLOCK(mp); 5539 free(*mvp, M_VNODE_MARKER); 5540 *mvp = NULL; 5541 } 5542 5543 /* 5544 * Relock the mp mount vnode list lock with the vp vnode interlock in the 5545 * conventional lock order during mnt_vnode_next_active iteration. 5546 * 5547 * On entry, the mount vnode list lock is held and the vnode interlock is not. 5548 * The list lock is dropped and reacquired. On success, both locks are held. 5549 * On failure, the mount vnode list lock is held but the vnode interlock is 5550 * not, and the procedure may have yielded. 5551 */ 5552 static bool 5553 mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp, 5554 struct vnode *vp) 5555 { 5556 const struct vnode *tmp; 5557 bool held, ret; 5558 5559 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 5560 TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp, 5561 ("%s: bad marker", __func__)); 5562 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 5563 ("%s: inappropriate vnode", __func__)); 5564 ASSERT_VI_UNLOCKED(vp, __func__); 5565 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5566 5567 ret = false; 5568 5569 TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist); 5570 TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist); 5571 5572 /* 5573 * Use a hold to prevent vp from disappearing while the mount vnode 5574 * list lock is dropped and reacquired. Normally a hold would be 5575 * acquired with vhold(), but that might try to acquire the vnode 5576 * interlock, which would be a LOR with the mount vnode list lock. 5577 */ 5578 held = refcount_acquire_if_not_zero(&vp->v_holdcnt); 5579 mtx_unlock(&mp->mnt_listmtx); 5580 if (!held) 5581 goto abort; 5582 VI_LOCK(vp); 5583 if (!refcount_release_if_not_last(&vp->v_holdcnt)) { 5584 vdropl(vp); 5585 goto abort; 5586 } 5587 mtx_lock(&mp->mnt_listmtx); 5588 5589 /* 5590 * Determine whether the vnode is still the next one after the marker, 5591 * excepting any other markers. If the vnode has not been doomed by 5592 * vgone() then the hold should have ensured that it remained on the 5593 * active list. If it has been doomed but is still on the active list, 5594 * don't abort, but rather skip over it (avoid spinning on doomed 5595 * vnodes). 5596 */ 5597 tmp = mvp; 5598 do { 5599 tmp = TAILQ_NEXT(tmp, v_actfreelist); 5600 } while (tmp != NULL && tmp->v_type == VMARKER); 5601 if (tmp != vp) { 5602 mtx_unlock(&mp->mnt_listmtx); 5603 VI_UNLOCK(vp); 5604 goto abort; 5605 } 5606 5607 ret = true; 5608 goto out; 5609 abort: 5610 maybe_yield(); 5611 mtx_lock(&mp->mnt_listmtx); 5612 out: 5613 if (ret) 5614 ASSERT_VI_LOCKED(vp, __func__); 5615 else 5616 ASSERT_VI_UNLOCKED(vp, __func__); 5617 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5618 return (ret); 5619 } 5620 5621 static struct vnode * 5622 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5623 { 5624 struct vnode *vp, *nvp; 5625 5626 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5627 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5628 restart: 5629 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5630 while (vp != NULL) { 5631 if (vp->v_type == VMARKER) { 5632 vp = TAILQ_NEXT(vp, v_actfreelist); 5633 continue; 5634 } 5635 /* 5636 * Try-lock because this is the wrong lock order. If that does 5637 * not succeed, drop the mount vnode list lock and try to 5638 * reacquire it and the vnode interlock in the right order. 5639 */ 5640 if (!VI_TRYLOCK(vp) && 5641 !mnt_vnode_next_active_relock(*mvp, mp, vp)) 5642 goto restart; 5643 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5644 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5645 ("alien vnode on the active list %p %p", vp, mp)); 5646 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) 5647 break; 5648 nvp = TAILQ_NEXT(vp, v_actfreelist); 5649 VI_UNLOCK(vp); 5650 vp = nvp; 5651 } 5652 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5653 5654 /* Check if we are done */ 5655 if (vp == NULL) { 5656 mtx_unlock(&mp->mnt_listmtx); 5657 mnt_vnode_markerfree_active(mvp, mp); 5658 return (NULL); 5659 } 5660 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 5661 mtx_unlock(&mp->mnt_listmtx); 5662 ASSERT_VI_LOCKED(vp, "active iter"); 5663 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 5664 return (vp); 5665 } 5666 5667 struct vnode * 5668 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5669 { 5670 5671 if (should_yield()) 5672 kern_yield(PRI_USER); 5673 mtx_lock(&mp->mnt_listmtx); 5674 return (mnt_vnode_next_active(mvp, mp)); 5675 } 5676 5677 struct vnode * 5678 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 5679 { 5680 struct vnode *vp; 5681 5682 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5683 MNT_ILOCK(mp); 5684 MNT_REF(mp); 5685 MNT_IUNLOCK(mp); 5686 (*mvp)->v_type = VMARKER; 5687 (*mvp)->v_mount = mp; 5688 5689 mtx_lock(&mp->mnt_listmtx); 5690 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 5691 if (vp == NULL) { 5692 mtx_unlock(&mp->mnt_listmtx); 5693 mnt_vnode_markerfree_active(mvp, mp); 5694 return (NULL); 5695 } 5696 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5697 return (mnt_vnode_next_active(mvp, mp)); 5698 } 5699 5700 void 5701 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5702 { 5703 5704 if (*mvp == NULL) 5705 return; 5706 5707 mtx_lock(&mp->mnt_listmtx); 5708 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5709 mtx_unlock(&mp->mnt_listmtx); 5710 mnt_vnode_markerfree_active(mvp, mp); 5711 } 5712