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/condvar.h> 54 #include <sys/conf.h> 55 #include <sys/counter.h> 56 #include <sys/dirent.h> 57 #include <sys/event.h> 58 #include <sys/eventhandler.h> 59 #include <sys/extattr.h> 60 #include <sys/file.h> 61 #include <sys/fcntl.h> 62 #include <sys/jail.h> 63 #include <sys/kdb.h> 64 #include <sys/kernel.h> 65 #include <sys/kthread.h> 66 #include <sys/lockf.h> 67 #include <sys/malloc.h> 68 #include <sys/mount.h> 69 #include <sys/namei.h> 70 #include <sys/pctrie.h> 71 #include <sys/priv.h> 72 #include <sys/reboot.h> 73 #include <sys/refcount.h> 74 #include <sys/rwlock.h> 75 #include <sys/sched.h> 76 #include <sys/sleepqueue.h> 77 #include <sys/smp.h> 78 #include <sys/stat.h> 79 #include <sys/sysctl.h> 80 #include <sys/syslog.h> 81 #include <sys/vmmeter.h> 82 #include <sys/vnode.h> 83 #include <sys/watchdog.h> 84 85 #include <machine/stdarg.h> 86 87 #include <security/mac/mac_framework.h> 88 89 #include <vm/vm.h> 90 #include <vm/vm_object.h> 91 #include <vm/vm_extern.h> 92 #include <vm/pmap.h> 93 #include <vm/vm_map.h> 94 #include <vm/vm_page.h> 95 #include <vm/vm_kern.h> 96 #include <vm/uma.h> 97 98 #ifdef DDB 99 #include <ddb/ddb.h> 100 #endif 101 102 static void delmntque(struct vnode *vp); 103 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 104 int slpflag, int slptimeo); 105 static void syncer_shutdown(void *arg, int howto); 106 static int vtryrecycle(struct vnode *vp); 107 static void v_init_counters(struct vnode *); 108 static void v_incr_usecount(struct vnode *); 109 static void v_incr_usecount_locked(struct vnode *); 110 static void v_incr_devcount(struct vnode *); 111 static void v_decr_devcount(struct vnode *); 112 static void vgonel(struct vnode *); 113 static void vfs_knllock(void *arg); 114 static void vfs_knlunlock(void *arg); 115 static void vfs_knl_assert_locked(void *arg); 116 static void vfs_knl_assert_unlocked(void *arg); 117 static void vnlru_return_batches(struct vfsops *mnt_op); 118 static void destroy_vpollinfo(struct vpollinfo *vi); 119 120 /* 121 * These fences are intended for cases where some synchronization is 122 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt 123 * and v_usecount) updates. Access to v_iflags is generally synchronized 124 * by the interlock, but we have some internal assertions that check vnode 125 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only 126 * for now. 127 */ 128 #ifdef INVARIANTS 129 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() 130 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() 131 #else 132 #define VNODE_REFCOUNT_FENCE_ACQ() 133 #define VNODE_REFCOUNT_FENCE_REL() 134 #endif 135 136 /* 137 * Number of vnodes in existence. Increased whenever getnewvnode() 138 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode. 139 */ 140 static unsigned long numvnodes; 141 142 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 143 "Number of vnodes in existence"); 144 145 static counter_u64_t vnodes_created; 146 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 147 "Number of vnodes created by getnewvnode"); 148 149 static u_long mnt_free_list_batch = 128; 150 SYSCTL_ULONG(_vfs, OID_AUTO, mnt_free_list_batch, CTLFLAG_RW, 151 &mnt_free_list_batch, 0, "Limit of vnodes held on mnt's free list"); 152 153 /* 154 * Conversion tables for conversion from vnode types to inode formats 155 * and back. 156 */ 157 enum vtype iftovt_tab[16] = { 158 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 159 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 160 }; 161 int vttoif_tab[10] = { 162 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 163 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 164 }; 165 166 /* 167 * List of vnodes that are ready for recycling. 168 */ 169 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 170 171 /* 172 * "Free" vnode target. Free vnodes are rarely completely free, but are 173 * just ones that are cheap to recycle. Usually they are for files which 174 * have been stat'd but not read; these usually have inode and namecache 175 * data attached to them. This target is the preferred minimum size of a 176 * sub-cache consisting mostly of such files. The system balances the size 177 * of this sub-cache with its complement to try to prevent either from 178 * thrashing while the other is relatively inactive. The targets express 179 * a preference for the best balance. 180 * 181 * "Above" this target there are 2 further targets (watermarks) related 182 * to recyling of free vnodes. In the best-operating case, the cache is 183 * exactly full, the free list has size between vlowat and vhiwat above the 184 * free target, and recycling from it and normal use maintains this state. 185 * Sometimes the free list is below vlowat or even empty, but this state 186 * is even better for immediate use provided the cache is not full. 187 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 188 * ones) to reach one of these states. The watermarks are currently hard- 189 * coded as 4% and 9% of the available space higher. These and the default 190 * of 25% for wantfreevnodes are too large if the memory size is large. 191 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 192 * whenever vnlru_proc() becomes active. 193 */ 194 static u_long wantfreevnodes; 195 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, 196 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes"); 197 static u_long freevnodes; 198 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 199 &freevnodes, 0, "Number of \"free\" vnodes"); 200 201 static counter_u64_t recycles_count; 202 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 203 "Number of vnodes recycled to meet vnode cache targets"); 204 205 /* 206 * Various variables used for debugging the new implementation of 207 * reassignbuf(). 208 * XXX these are probably of (very) limited utility now. 209 */ 210 static int reassignbufcalls; 211 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, 212 "Number of calls to reassignbuf"); 213 214 static counter_u64_t free_owe_inact; 215 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, 216 "Number of times free vnodes kept on active list due to VFS " 217 "owing inactivation"); 218 219 /* To keep more than one thread at a time from running vfs_getnewfsid */ 220 static struct mtx mntid_mtx; 221 222 /* 223 * Lock for any access to the following: 224 * vnode_free_list 225 * numvnodes 226 * freevnodes 227 */ 228 static struct mtx vnode_free_list_mtx; 229 230 /* Publicly exported FS */ 231 struct nfs_public nfs_pub; 232 233 static uma_zone_t buf_trie_zone; 234 235 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 236 static uma_zone_t vnode_zone; 237 static uma_zone_t vnodepoll_zone; 238 239 /* 240 * The workitem queue. 241 * 242 * It is useful to delay writes of file data and filesystem metadata 243 * for tens of seconds so that quickly created and deleted files need 244 * not waste disk bandwidth being created and removed. To realize this, 245 * we append vnodes to a "workitem" queue. When running with a soft 246 * updates implementation, most pending metadata dependencies should 247 * not wait for more than a few seconds. Thus, mounted on block devices 248 * are delayed only about a half the time that file data is delayed. 249 * Similarly, directory updates are more critical, so are only delayed 250 * about a third the time that file data is delayed. Thus, there are 251 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 252 * one each second (driven off the filesystem syncer process). The 253 * syncer_delayno variable indicates the next queue that is to be processed. 254 * Items that need to be processed soon are placed in this queue: 255 * 256 * syncer_workitem_pending[syncer_delayno] 257 * 258 * A delay of fifteen seconds is done by placing the request fifteen 259 * entries later in the queue: 260 * 261 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 262 * 263 */ 264 static int syncer_delayno; 265 static long syncer_mask; 266 LIST_HEAD(synclist, bufobj); 267 static struct synclist *syncer_workitem_pending; 268 /* 269 * The sync_mtx protects: 270 * bo->bo_synclist 271 * sync_vnode_count 272 * syncer_delayno 273 * syncer_state 274 * syncer_workitem_pending 275 * syncer_worklist_len 276 * rushjob 277 */ 278 static struct mtx sync_mtx; 279 static struct cv sync_wakeup; 280 281 #define SYNCER_MAXDELAY 32 282 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 283 static int syncdelay = 30; /* max time to delay syncing data */ 284 static int filedelay = 30; /* time to delay syncing files */ 285 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 286 "Time to delay syncing files (in seconds)"); 287 static int dirdelay = 29; /* time to delay syncing directories */ 288 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 289 "Time to delay syncing directories (in seconds)"); 290 static int metadelay = 28; /* time to delay syncing metadata */ 291 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 292 "Time to delay syncing metadata (in seconds)"); 293 static int rushjob; /* number of slots to run ASAP */ 294 static int stat_rush_requests; /* number of times I/O speeded up */ 295 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 296 "Number of times I/O speeded up (rush requests)"); 297 298 /* 299 * When shutting down the syncer, run it at four times normal speed. 300 */ 301 #define SYNCER_SHUTDOWN_SPEEDUP 4 302 static int sync_vnode_count; 303 static int syncer_worklist_len; 304 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 305 syncer_state; 306 307 /* Target for maximum number of vnodes. */ 308 int desiredvnodes; 309 static int gapvnodes; /* gap between wanted and desired */ 310 static int vhiwat; /* enough extras after expansion */ 311 static int vlowat; /* minimal extras before expansion */ 312 static int vstir; /* nonzero to stir non-free vnodes */ 313 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 314 315 static int 316 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS) 317 { 318 int error, old_desiredvnodes; 319 320 old_desiredvnodes = desiredvnodes; 321 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0) 322 return (error); 323 if (old_desiredvnodes != desiredvnodes) { 324 wantfreevnodes = desiredvnodes / 4; 325 /* XXX locking seems to be incomplete. */ 326 vfs_hash_changesize(desiredvnodes); 327 cache_changesize(desiredvnodes); 328 } 329 return (0); 330 } 331 332 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 333 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0, 334 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes"); 335 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 336 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 337 static int vnlru_nowhere; 338 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 339 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 340 341 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 342 static int vnsz2log; 343 344 /* 345 * Support for the bufobj clean & dirty pctrie. 346 */ 347 static void * 348 buf_trie_alloc(struct pctrie *ptree) 349 { 350 351 return uma_zalloc(buf_trie_zone, M_NOWAIT); 352 } 353 354 static void 355 buf_trie_free(struct pctrie *ptree, void *node) 356 { 357 358 uma_zfree(buf_trie_zone, node); 359 } 360 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 361 362 /* 363 * Initialize the vnode management data structures. 364 * 365 * Reevaluate the following cap on the number of vnodes after the physical 366 * memory size exceeds 512GB. In the limit, as the physical memory size 367 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 368 */ 369 #ifndef MAXVNODES_MAX 370 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */ 371 #endif 372 373 /* 374 * Initialize a vnode as it first enters the zone. 375 */ 376 static int 377 vnode_init(void *mem, int size, int flags) 378 { 379 struct vnode *vp; 380 381 vp = mem; 382 bzero(vp, size); 383 /* 384 * Setup locks. 385 */ 386 vp->v_vnlock = &vp->v_lock; 387 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 388 /* 389 * By default, don't allow shared locks unless filesystems opt-in. 390 */ 391 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 392 LK_NOSHARE | LK_IS_VNODE); 393 /* 394 * Initialize bufobj. 395 */ 396 bufobj_init(&vp->v_bufobj, vp); 397 /* 398 * Initialize namecache. 399 */ 400 LIST_INIT(&vp->v_cache_src); 401 TAILQ_INIT(&vp->v_cache_dst); 402 /* 403 * Initialize rangelocks. 404 */ 405 rangelock_init(&vp->v_rl); 406 return (0); 407 } 408 409 /* 410 * Free a vnode when it is cleared from the zone. 411 */ 412 static void 413 vnode_fini(void *mem, int size) 414 { 415 struct vnode *vp; 416 struct bufobj *bo; 417 418 vp = mem; 419 rangelock_destroy(&vp->v_rl); 420 lockdestroy(vp->v_vnlock); 421 mtx_destroy(&vp->v_interlock); 422 bo = &vp->v_bufobj; 423 rw_destroy(BO_LOCKPTR(bo)); 424 } 425 426 /* 427 * Provide the size of NFS nclnode and NFS fh for calculation of the 428 * vnode memory consumption. The size is specified directly to 429 * eliminate dependency on NFS-private header. 430 * 431 * Other filesystems may use bigger or smaller (like UFS and ZFS) 432 * private inode data, but the NFS-based estimation is ample enough. 433 * Still, we care about differences in the size between 64- and 32-bit 434 * platforms. 435 * 436 * Namecache structure size is heuristically 437 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 438 */ 439 #ifdef _LP64 440 #define NFS_NCLNODE_SZ (528 + 64) 441 #define NC_SZ 148 442 #else 443 #define NFS_NCLNODE_SZ (360 + 32) 444 #define NC_SZ 92 445 #endif 446 447 static void 448 vntblinit(void *dummy __unused) 449 { 450 u_int i; 451 int physvnodes, virtvnodes; 452 453 /* 454 * Desiredvnodes is a function of the physical memory size and the 455 * kernel's heap size. Generally speaking, it scales with the 456 * physical memory size. The ratio of desiredvnodes to the physical 457 * memory size is 1:16 until desiredvnodes exceeds 98,304. 458 * Thereafter, the 459 * marginal ratio of desiredvnodes to the physical memory size is 460 * 1:64. However, desiredvnodes is limited by the kernel's heap 461 * size. The memory required by desiredvnodes vnodes and vm objects 462 * must not exceed 1/10th of the kernel's heap size. 463 */ 464 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 465 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 466 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 467 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 468 desiredvnodes = min(physvnodes, virtvnodes); 469 if (desiredvnodes > MAXVNODES_MAX) { 470 if (bootverbose) 471 printf("Reducing kern.maxvnodes %d -> %d\n", 472 desiredvnodes, MAXVNODES_MAX); 473 desiredvnodes = MAXVNODES_MAX; 474 } 475 wantfreevnodes = desiredvnodes / 4; 476 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 477 TAILQ_INIT(&vnode_free_list); 478 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 479 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 480 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 481 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 482 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 483 /* 484 * Preallocate enough nodes to support one-per buf so that 485 * we can not fail an insert. reassignbuf() callers can not 486 * tolerate the insertion failure. 487 */ 488 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 489 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 490 UMA_ZONE_NOFREE | UMA_ZONE_VM); 491 uma_prealloc(buf_trie_zone, nbuf); 492 493 vnodes_created = counter_u64_alloc(M_WAITOK); 494 recycles_count = counter_u64_alloc(M_WAITOK); 495 free_owe_inact = counter_u64_alloc(M_WAITOK); 496 497 /* 498 * Initialize the filesystem syncer. 499 */ 500 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 501 &syncer_mask); 502 syncer_maxdelay = syncer_mask + 1; 503 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 504 cv_init(&sync_wakeup, "syncer"); 505 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 506 vnsz2log++; 507 vnsz2log--; 508 } 509 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 510 511 512 /* 513 * Mark a mount point as busy. Used to synchronize access and to delay 514 * unmounting. Eventually, mountlist_mtx is not released on failure. 515 * 516 * vfs_busy() is a custom lock, it can block the caller. 517 * vfs_busy() only sleeps if the unmount is active on the mount point. 518 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 519 * vnode belonging to mp. 520 * 521 * Lookup uses vfs_busy() to traverse mount points. 522 * root fs var fs 523 * / vnode lock A / vnode lock (/var) D 524 * /var vnode lock B /log vnode lock(/var/log) E 525 * vfs_busy lock C vfs_busy lock F 526 * 527 * Within each file system, the lock order is C->A->B and F->D->E. 528 * 529 * When traversing across mounts, the system follows that lock order: 530 * 531 * C->A->B 532 * | 533 * +->F->D->E 534 * 535 * The lookup() process for namei("/var") illustrates the process: 536 * VOP_LOOKUP() obtains B while A is held 537 * vfs_busy() obtains a shared lock on F while A and B are held 538 * vput() releases lock on B 539 * vput() releases lock on A 540 * VFS_ROOT() obtains lock on D while shared lock on F is held 541 * vfs_unbusy() releases shared lock on F 542 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 543 * Attempt to lock A (instead of vp_crossmp) while D is held would 544 * violate the global order, causing deadlocks. 545 * 546 * dounmount() locks B while F is drained. 547 */ 548 int 549 vfs_busy(struct mount *mp, int flags) 550 { 551 552 MPASS((flags & ~MBF_MASK) == 0); 553 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 554 555 MNT_ILOCK(mp); 556 MNT_REF(mp); 557 /* 558 * If mount point is currently being unmounted, sleep until the 559 * mount point fate is decided. If thread doing the unmounting fails, 560 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 561 * that this mount point has survived the unmount attempt and vfs_busy 562 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 563 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 564 * about to be really destroyed. vfs_busy needs to release its 565 * reference on the mount point in this case and return with ENOENT, 566 * telling the caller that mount mount it tried to busy is no longer 567 * valid. 568 */ 569 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 570 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 571 MNT_REL(mp); 572 MNT_IUNLOCK(mp); 573 CTR1(KTR_VFS, "%s: failed busying before sleeping", 574 __func__); 575 return (ENOENT); 576 } 577 if (flags & MBF_MNTLSTLOCK) 578 mtx_unlock(&mountlist_mtx); 579 mp->mnt_kern_flag |= MNTK_MWAIT; 580 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 581 if (flags & MBF_MNTLSTLOCK) 582 mtx_lock(&mountlist_mtx); 583 MNT_ILOCK(mp); 584 } 585 if (flags & MBF_MNTLSTLOCK) 586 mtx_unlock(&mountlist_mtx); 587 mp->mnt_lockref++; 588 MNT_IUNLOCK(mp); 589 return (0); 590 } 591 592 /* 593 * Free a busy filesystem. 594 */ 595 void 596 vfs_unbusy(struct mount *mp) 597 { 598 599 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 600 MNT_ILOCK(mp); 601 MNT_REL(mp); 602 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref")); 603 mp->mnt_lockref--; 604 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 605 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 606 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 607 mp->mnt_kern_flag &= ~MNTK_DRAINING; 608 wakeup(&mp->mnt_lockref); 609 } 610 MNT_IUNLOCK(mp); 611 } 612 613 /* 614 * Lookup a mount point by filesystem identifier. 615 */ 616 struct mount * 617 vfs_getvfs(fsid_t *fsid) 618 { 619 struct mount *mp; 620 621 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 622 mtx_lock(&mountlist_mtx); 623 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 624 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 625 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 626 vfs_ref(mp); 627 mtx_unlock(&mountlist_mtx); 628 return (mp); 629 } 630 } 631 mtx_unlock(&mountlist_mtx); 632 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 633 return ((struct mount *) 0); 634 } 635 636 /* 637 * Lookup a mount point by filesystem identifier, busying it before 638 * returning. 639 * 640 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 641 * cache for popular filesystem identifiers. The cache is lockess, using 642 * the fact that struct mount's are never freed. In worst case we may 643 * get pointer to unmounted or even different filesystem, so we have to 644 * check what we got, and go slow way if so. 645 */ 646 struct mount * 647 vfs_busyfs(fsid_t *fsid) 648 { 649 #define FSID_CACHE_SIZE 256 650 typedef struct mount * volatile vmp_t; 651 static vmp_t cache[FSID_CACHE_SIZE]; 652 struct mount *mp; 653 int error; 654 uint32_t hash; 655 656 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 657 hash = fsid->val[0] ^ fsid->val[1]; 658 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 659 mp = cache[hash]; 660 if (mp == NULL || 661 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 662 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 663 goto slow; 664 if (vfs_busy(mp, 0) != 0) { 665 cache[hash] = NULL; 666 goto slow; 667 } 668 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 669 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 670 return (mp); 671 else 672 vfs_unbusy(mp); 673 674 slow: 675 mtx_lock(&mountlist_mtx); 676 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 677 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 678 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 679 error = vfs_busy(mp, MBF_MNTLSTLOCK); 680 if (error) { 681 cache[hash] = NULL; 682 mtx_unlock(&mountlist_mtx); 683 return (NULL); 684 } 685 cache[hash] = mp; 686 return (mp); 687 } 688 } 689 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 690 mtx_unlock(&mountlist_mtx); 691 return ((struct mount *) 0); 692 } 693 694 /* 695 * Check if a user can access privileged mount options. 696 */ 697 int 698 vfs_suser(struct mount *mp, struct thread *td) 699 { 700 int error; 701 702 if (jailed(td->td_ucred)) { 703 /* 704 * If the jail of the calling thread lacks permission for 705 * this type of file system, deny immediately. 706 */ 707 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) 708 return (EPERM); 709 710 /* 711 * If the file system was mounted outside the jail of the 712 * calling thread, deny immediately. 713 */ 714 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 715 return (EPERM); 716 } 717 718 /* 719 * If file system supports delegated administration, we don't check 720 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 721 * by the file system itself. 722 * If this is not the user that did original mount, we check for 723 * the PRIV_VFS_MOUNT_OWNER privilege. 724 */ 725 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 726 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 727 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 728 return (error); 729 } 730 return (0); 731 } 732 733 /* 734 * Get a new unique fsid. Try to make its val[0] unique, since this value 735 * will be used to create fake device numbers for stat(). Also try (but 736 * not so hard) make its val[0] unique mod 2^16, since some emulators only 737 * support 16-bit device numbers. We end up with unique val[0]'s for the 738 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 739 * 740 * Keep in mind that several mounts may be running in parallel. Starting 741 * the search one past where the previous search terminated is both a 742 * micro-optimization and a defense against returning the same fsid to 743 * different mounts. 744 */ 745 void 746 vfs_getnewfsid(struct mount *mp) 747 { 748 static uint16_t mntid_base; 749 struct mount *nmp; 750 fsid_t tfsid; 751 int mtype; 752 753 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 754 mtx_lock(&mntid_mtx); 755 mtype = mp->mnt_vfc->vfc_typenum; 756 tfsid.val[1] = mtype; 757 mtype = (mtype & 0xFF) << 24; 758 for (;;) { 759 tfsid.val[0] = makedev(255, 760 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 761 mntid_base++; 762 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 763 break; 764 vfs_rel(nmp); 765 } 766 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 767 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 768 mtx_unlock(&mntid_mtx); 769 } 770 771 /* 772 * Knob to control the precision of file timestamps: 773 * 774 * 0 = seconds only; nanoseconds zeroed. 775 * 1 = seconds and nanoseconds, accurate within 1/HZ. 776 * 2 = seconds and nanoseconds, truncated to microseconds. 777 * >=3 = seconds and nanoseconds, maximum precision. 778 */ 779 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 780 781 static int timestamp_precision = TSP_USEC; 782 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 783 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 784 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 785 "3+: sec + ns (max. precision))"); 786 787 /* 788 * Get a current timestamp. 789 */ 790 void 791 vfs_timestamp(struct timespec *tsp) 792 { 793 struct timeval tv; 794 795 switch (timestamp_precision) { 796 case TSP_SEC: 797 tsp->tv_sec = time_second; 798 tsp->tv_nsec = 0; 799 break; 800 case TSP_HZ: 801 getnanotime(tsp); 802 break; 803 case TSP_USEC: 804 microtime(&tv); 805 TIMEVAL_TO_TIMESPEC(&tv, tsp); 806 break; 807 case TSP_NSEC: 808 default: 809 nanotime(tsp); 810 break; 811 } 812 } 813 814 /* 815 * Set vnode attributes to VNOVAL 816 */ 817 void 818 vattr_null(struct vattr *vap) 819 { 820 821 vap->va_type = VNON; 822 vap->va_size = VNOVAL; 823 vap->va_bytes = VNOVAL; 824 vap->va_mode = VNOVAL; 825 vap->va_nlink = VNOVAL; 826 vap->va_uid = VNOVAL; 827 vap->va_gid = VNOVAL; 828 vap->va_fsid = VNOVAL; 829 vap->va_fileid = VNOVAL; 830 vap->va_blocksize = VNOVAL; 831 vap->va_rdev = VNOVAL; 832 vap->va_atime.tv_sec = VNOVAL; 833 vap->va_atime.tv_nsec = VNOVAL; 834 vap->va_mtime.tv_sec = VNOVAL; 835 vap->va_mtime.tv_nsec = VNOVAL; 836 vap->va_ctime.tv_sec = VNOVAL; 837 vap->va_ctime.tv_nsec = VNOVAL; 838 vap->va_birthtime.tv_sec = VNOVAL; 839 vap->va_birthtime.tv_nsec = VNOVAL; 840 vap->va_flags = VNOVAL; 841 vap->va_gen = VNOVAL; 842 vap->va_vaflags = 0; 843 } 844 845 /* 846 * This routine is called when we have too many vnodes. It attempts 847 * to free <count> vnodes and will potentially free vnodes that still 848 * have VM backing store (VM backing store is typically the cause 849 * of a vnode blowout so we want to do this). Therefore, this operation 850 * is not considered cheap. 851 * 852 * A number of conditions may prevent a vnode from being reclaimed. 853 * the buffer cache may have references on the vnode, a directory 854 * vnode may still have references due to the namei cache representing 855 * underlying files, or the vnode may be in active use. It is not 856 * desirable to reuse such vnodes. These conditions may cause the 857 * number of vnodes to reach some minimum value regardless of what 858 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 859 */ 860 static int 861 vlrureclaim(struct mount *mp, int reclaim_nc_src, int trigger) 862 { 863 struct vnode *vp; 864 int count, done, target; 865 866 done = 0; 867 vn_start_write(NULL, &mp, V_WAIT); 868 MNT_ILOCK(mp); 869 count = mp->mnt_nvnodelistsize; 870 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1); 871 target = target / 10 + 1; 872 while (count != 0 && done < target) { 873 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 874 while (vp != NULL && vp->v_type == VMARKER) 875 vp = TAILQ_NEXT(vp, v_nmntvnodes); 876 if (vp == NULL) 877 break; 878 /* 879 * XXX LRU is completely broken for non-free vnodes. First 880 * by calling here in mountpoint order, then by moving 881 * unselected vnodes to the end here, and most grossly by 882 * removing the vlruvp() function that was supposed to 883 * maintain the order. (This function was born broken 884 * since syncer problems prevented it doing anything.) The 885 * order is closer to LRC (C = Created). 886 * 887 * LRU reclaiming of vnodes seems to have last worked in 888 * FreeBSD-3 where LRU wasn't mentioned under any spelling. 889 * Then there was no hold count, and inactive vnodes were 890 * simply put on the free list in LRU order. The separate 891 * lists also break LRU. We prefer to reclaim from the 892 * free list for technical reasons. This tends to thrash 893 * the free list to keep very unrecently used held vnodes. 894 * The problem is mitigated by keeping the free list large. 895 */ 896 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 897 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 898 --count; 899 if (!VI_TRYLOCK(vp)) 900 goto next_iter; 901 /* 902 * If it's been deconstructed already, it's still 903 * referenced, or it exceeds the trigger, skip it. 904 * Also skip free vnodes. We are trying to make space 905 * to expand the free list, not reduce it. 906 */ 907 if (vp->v_usecount || 908 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 909 ((vp->v_iflag & VI_FREE) != 0) || 910 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 911 vp->v_object->resident_page_count > trigger)) { 912 VI_UNLOCK(vp); 913 goto next_iter; 914 } 915 MNT_IUNLOCK(mp); 916 vholdl(vp); 917 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 918 vdrop(vp); 919 goto next_iter_mntunlocked; 920 } 921 VI_LOCK(vp); 922 /* 923 * v_usecount may have been bumped after VOP_LOCK() dropped 924 * the vnode interlock and before it was locked again. 925 * 926 * It is not necessary to recheck VI_DOOMED because it can 927 * only be set by another thread that holds both the vnode 928 * lock and vnode interlock. If another thread has the 929 * vnode lock before we get to VOP_LOCK() and obtains the 930 * vnode interlock after VOP_LOCK() drops the vnode 931 * interlock, the other thread will be unable to drop the 932 * vnode lock before our VOP_LOCK() call fails. 933 */ 934 if (vp->v_usecount || 935 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 936 (vp->v_iflag & VI_FREE) != 0 || 937 (vp->v_object != NULL && 938 vp->v_object->resident_page_count > trigger)) { 939 VOP_UNLOCK(vp, LK_INTERLOCK); 940 vdrop(vp); 941 goto next_iter_mntunlocked; 942 } 943 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 944 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 945 counter_u64_add(recycles_count, 1); 946 vgonel(vp); 947 VOP_UNLOCK(vp, 0); 948 vdropl(vp); 949 done++; 950 next_iter_mntunlocked: 951 if (!should_yield()) 952 goto relock_mnt; 953 goto yield; 954 next_iter: 955 if (!should_yield()) 956 continue; 957 MNT_IUNLOCK(mp); 958 yield: 959 kern_yield(PRI_USER); 960 relock_mnt: 961 MNT_ILOCK(mp); 962 } 963 MNT_IUNLOCK(mp); 964 vn_finished_write(mp); 965 return done; 966 } 967 968 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 969 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 970 0, 971 "limit on vnode free requests per call to the vnlru_free routine"); 972 973 /* 974 * Attempt to reduce the free list by the requested amount. 975 */ 976 static void 977 vnlru_free_locked(int count, struct vfsops *mnt_op) 978 { 979 struct vnode *vp; 980 struct mount *mp; 981 bool tried_batches; 982 983 tried_batches = false; 984 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 985 if (count > max_vnlru_free) 986 count = max_vnlru_free; 987 for (; count > 0; count--) { 988 vp = TAILQ_FIRST(&vnode_free_list); 989 /* 990 * The list can be modified while the free_list_mtx 991 * has been dropped and vp could be NULL here. 992 */ 993 if (vp == NULL) { 994 if (tried_batches) 995 break; 996 mtx_unlock(&vnode_free_list_mtx); 997 vnlru_return_batches(mnt_op); 998 tried_batches = true; 999 mtx_lock(&vnode_free_list_mtx); 1000 continue; 1001 } 1002 1003 VNASSERT(vp->v_op != NULL, vp, 1004 ("vnlru_free: vnode already reclaimed.")); 1005 KASSERT((vp->v_iflag & VI_FREE) != 0, 1006 ("Removing vnode not on freelist")); 1007 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1008 ("Mangling active vnode")); 1009 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 1010 1011 /* 1012 * Don't recycle if our vnode is from different type 1013 * of mount point. Note that mp is type-safe, the 1014 * check does not reach unmapped address even if 1015 * vnode is reclaimed. 1016 * Don't recycle if we can't get the interlock without 1017 * blocking. 1018 */ 1019 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL && 1020 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1021 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist); 1022 continue; 1023 } 1024 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0, 1025 vp, ("vp inconsistent on freelist")); 1026 1027 /* 1028 * The clear of VI_FREE prevents activation of the 1029 * vnode. There is no sense in putting the vnode on 1030 * the mount point active list, only to remove it 1031 * later during recycling. Inline the relevant part 1032 * of vholdl(), to avoid triggering assertions or 1033 * activating. 1034 */ 1035 freevnodes--; 1036 vp->v_iflag &= ~VI_FREE; 1037 VNODE_REFCOUNT_FENCE_REL(); 1038 refcount_acquire(&vp->v_holdcnt); 1039 1040 mtx_unlock(&vnode_free_list_mtx); 1041 VI_UNLOCK(vp); 1042 vtryrecycle(vp); 1043 /* 1044 * If the recycled succeeded this vdrop will actually free 1045 * the vnode. If not it will simply place it back on 1046 * the free list. 1047 */ 1048 vdrop(vp); 1049 mtx_lock(&vnode_free_list_mtx); 1050 } 1051 } 1052 1053 void 1054 vnlru_free(int count, struct vfsops *mnt_op) 1055 { 1056 1057 mtx_lock(&vnode_free_list_mtx); 1058 vnlru_free_locked(count, mnt_op); 1059 mtx_unlock(&vnode_free_list_mtx); 1060 } 1061 1062 1063 /* XXX some names and initialization are bad for limits and watermarks. */ 1064 static int 1065 vspace(void) 1066 { 1067 int space; 1068 1069 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1070 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1071 vlowat = vhiwat / 2; 1072 if (numvnodes > desiredvnodes) 1073 return (0); 1074 space = desiredvnodes - numvnodes; 1075 if (freevnodes > wantfreevnodes) 1076 space += freevnodes - wantfreevnodes; 1077 return (space); 1078 } 1079 1080 static void 1081 vnlru_return_batch_locked(struct mount *mp) 1082 { 1083 struct vnode *vp; 1084 1085 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 1086 1087 if (mp->mnt_tmpfreevnodelistsize == 0) 1088 return; 1089 1090 TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) { 1091 VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp, 1092 ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist")); 1093 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 1094 } 1095 mtx_lock(&vnode_free_list_mtx); 1096 TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist); 1097 freevnodes += mp->mnt_tmpfreevnodelistsize; 1098 mtx_unlock(&vnode_free_list_mtx); 1099 mp->mnt_tmpfreevnodelistsize = 0; 1100 } 1101 1102 static void 1103 vnlru_return_batch(struct mount *mp) 1104 { 1105 1106 mtx_lock(&mp->mnt_listmtx); 1107 vnlru_return_batch_locked(mp); 1108 mtx_unlock(&mp->mnt_listmtx); 1109 } 1110 1111 static void 1112 vnlru_return_batches(struct vfsops *mnt_op) 1113 { 1114 struct mount *mp, *nmp; 1115 bool need_unbusy; 1116 1117 mtx_lock(&mountlist_mtx); 1118 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1119 need_unbusy = false; 1120 if (mnt_op != NULL && mp->mnt_op != mnt_op) 1121 goto next; 1122 if (mp->mnt_tmpfreevnodelistsize == 0) 1123 goto next; 1124 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) { 1125 vnlru_return_batch(mp); 1126 need_unbusy = true; 1127 mtx_lock(&mountlist_mtx); 1128 } 1129 next: 1130 nmp = TAILQ_NEXT(mp, mnt_list); 1131 if (need_unbusy) 1132 vfs_unbusy(mp); 1133 } 1134 mtx_unlock(&mountlist_mtx); 1135 } 1136 1137 /* 1138 * Attempt to recycle vnodes in a context that is always safe to block. 1139 * Calling vlrurecycle() from the bowels of filesystem code has some 1140 * interesting deadlock problems. 1141 */ 1142 static struct proc *vnlruproc; 1143 static int vnlruproc_sig; 1144 1145 static void 1146 vnlru_proc(void) 1147 { 1148 struct mount *mp, *nmp; 1149 unsigned long onumvnodes; 1150 int done, force, reclaim_nc_src, trigger, usevnodes; 1151 1152 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1153 SHUTDOWN_PRI_FIRST); 1154 1155 force = 0; 1156 for (;;) { 1157 kproc_suspend_check(vnlruproc); 1158 mtx_lock(&vnode_free_list_mtx); 1159 /* 1160 * If numvnodes is too large (due to desiredvnodes being 1161 * adjusted using its sysctl, or emergency growth), first 1162 * try to reduce it by discarding from the free list. 1163 */ 1164 if (numvnodes > desiredvnodes) 1165 vnlru_free_locked(numvnodes - desiredvnodes, NULL); 1166 /* 1167 * Sleep if the vnode cache is in a good state. This is 1168 * when it is not over-full and has space for about a 4% 1169 * or 9% expansion (by growing its size or inexcessively 1170 * reducing its free list). Otherwise, try to reclaim 1171 * space for a 10% expansion. 1172 */ 1173 if (vstir && force == 0) { 1174 force = 1; 1175 vstir = 0; 1176 } 1177 if (vspace() >= vlowat && force == 0) { 1178 vnlruproc_sig = 0; 1179 wakeup(&vnlruproc_sig); 1180 msleep(vnlruproc, &vnode_free_list_mtx, 1181 PVFS|PDROP, "vlruwt", hz); 1182 continue; 1183 } 1184 mtx_unlock(&vnode_free_list_mtx); 1185 done = 0; 1186 onumvnodes = numvnodes; 1187 /* 1188 * Calculate parameters for recycling. These are the same 1189 * throughout the loop to give some semblance of fairness. 1190 * The trigger point is to avoid recycling vnodes with lots 1191 * of resident pages. We aren't trying to free memory; we 1192 * are trying to recycle or at least free vnodes. 1193 */ 1194 if (numvnodes <= desiredvnodes) 1195 usevnodes = numvnodes - freevnodes; 1196 else 1197 usevnodes = numvnodes; 1198 if (usevnodes <= 0) 1199 usevnodes = 1; 1200 /* 1201 * The trigger value is is chosen to give a conservatively 1202 * large value to ensure that it alone doesn't prevent 1203 * making progress. The value can easily be so large that 1204 * it is effectively infinite in some congested and 1205 * misconfigured cases, and this is necessary. Normally 1206 * it is about 8 to 100 (pages), which is quite large. 1207 */ 1208 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1209 if (force < 2) 1210 trigger = vsmalltrigger; 1211 reclaim_nc_src = force >= 3; 1212 mtx_lock(&mountlist_mtx); 1213 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1214 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { 1215 nmp = TAILQ_NEXT(mp, mnt_list); 1216 continue; 1217 } 1218 done += vlrureclaim(mp, reclaim_nc_src, trigger); 1219 mtx_lock(&mountlist_mtx); 1220 nmp = TAILQ_NEXT(mp, mnt_list); 1221 vfs_unbusy(mp); 1222 } 1223 mtx_unlock(&mountlist_mtx); 1224 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1225 uma_reclaim(); 1226 if (done == 0) { 1227 if (force == 0 || force == 1) { 1228 force = 2; 1229 continue; 1230 } 1231 if (force == 2) { 1232 force = 3; 1233 continue; 1234 } 1235 force = 0; 1236 vnlru_nowhere++; 1237 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1238 } else 1239 kern_yield(PRI_USER); 1240 /* 1241 * After becoming active to expand above low water, keep 1242 * active until above high water. 1243 */ 1244 force = vspace() < vhiwat; 1245 } 1246 } 1247 1248 static struct kproc_desc vnlru_kp = { 1249 "vnlru", 1250 vnlru_proc, 1251 &vnlruproc 1252 }; 1253 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1254 &vnlru_kp); 1255 1256 /* 1257 * Routines having to do with the management of the vnode table. 1258 */ 1259 1260 /* 1261 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1262 * before we actually vgone(). This function must be called with the vnode 1263 * held to prevent the vnode from being returned to the free list midway 1264 * through vgone(). 1265 */ 1266 static int 1267 vtryrecycle(struct vnode *vp) 1268 { 1269 struct mount *vnmp; 1270 1271 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1272 VNASSERT(vp->v_holdcnt, vp, 1273 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1274 /* 1275 * This vnode may found and locked via some other list, if so we 1276 * can't recycle it yet. 1277 */ 1278 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1279 CTR2(KTR_VFS, 1280 "%s: impossible to recycle, vp %p lock is already held", 1281 __func__, vp); 1282 return (EWOULDBLOCK); 1283 } 1284 /* 1285 * Don't recycle if its filesystem is being suspended. 1286 */ 1287 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1288 VOP_UNLOCK(vp, 0); 1289 CTR2(KTR_VFS, 1290 "%s: impossible to recycle, cannot start the write for %p", 1291 __func__, vp); 1292 return (EBUSY); 1293 } 1294 /* 1295 * If we got this far, we need to acquire the interlock and see if 1296 * anyone picked up this vnode from another list. If not, we will 1297 * mark it with DOOMED via vgonel() so that anyone who does find it 1298 * will skip over it. 1299 */ 1300 VI_LOCK(vp); 1301 if (vp->v_usecount) { 1302 VOP_UNLOCK(vp, LK_INTERLOCK); 1303 vn_finished_write(vnmp); 1304 CTR2(KTR_VFS, 1305 "%s: impossible to recycle, %p is already referenced", 1306 __func__, vp); 1307 return (EBUSY); 1308 } 1309 if ((vp->v_iflag & VI_DOOMED) == 0) { 1310 counter_u64_add(recycles_count, 1); 1311 vgonel(vp); 1312 } 1313 VOP_UNLOCK(vp, LK_INTERLOCK); 1314 vn_finished_write(vnmp); 1315 return (0); 1316 } 1317 1318 static void 1319 vcheckspace(void) 1320 { 1321 1322 if (vspace() < vlowat && vnlruproc_sig == 0) { 1323 vnlruproc_sig = 1; 1324 wakeup(vnlruproc); 1325 } 1326 } 1327 1328 /* 1329 * Wait if necessary for space for a new vnode. 1330 */ 1331 static int 1332 getnewvnode_wait(int suspended) 1333 { 1334 1335 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1336 if (numvnodes >= desiredvnodes) { 1337 if (suspended) { 1338 /* 1339 * The file system is being suspended. We cannot 1340 * risk a deadlock here, so allow allocation of 1341 * another vnode even if this would give too many. 1342 */ 1343 return (0); 1344 } 1345 if (vnlruproc_sig == 0) { 1346 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 1347 wakeup(vnlruproc); 1348 } 1349 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 1350 "vlruwk", hz); 1351 } 1352 /* Post-adjust like the pre-adjust in getnewvnode(). */ 1353 if (numvnodes + 1 > desiredvnodes && freevnodes > 1) 1354 vnlru_free_locked(1, NULL); 1355 return (numvnodes >= desiredvnodes ? ENFILE : 0); 1356 } 1357 1358 /* 1359 * This hack is fragile, and probably not needed any more now that the 1360 * watermark handling works. 1361 */ 1362 void 1363 getnewvnode_reserve(u_int count) 1364 { 1365 struct thread *td; 1366 1367 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */ 1368 /* XXX no longer so quick, but this part is not racy. */ 1369 mtx_lock(&vnode_free_list_mtx); 1370 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes) 1371 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes, 1372 freevnodes - wantfreevnodes), NULL); 1373 mtx_unlock(&vnode_free_list_mtx); 1374 1375 td = curthread; 1376 /* First try to be quick and racy. */ 1377 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) { 1378 td->td_vp_reserv += count; 1379 vcheckspace(); /* XXX no longer so quick, but more racy */ 1380 return; 1381 } else 1382 atomic_subtract_long(&numvnodes, count); 1383 1384 mtx_lock(&vnode_free_list_mtx); 1385 while (count > 0) { 1386 if (getnewvnode_wait(0) == 0) { 1387 count--; 1388 td->td_vp_reserv++; 1389 atomic_add_long(&numvnodes, 1); 1390 } 1391 } 1392 vcheckspace(); 1393 mtx_unlock(&vnode_free_list_mtx); 1394 } 1395 1396 /* 1397 * This hack is fragile, especially if desiredvnodes or wantvnodes are 1398 * misconfgured or changed significantly. Reducing desiredvnodes below 1399 * the reserved amount should cause bizarre behaviour like reducing it 1400 * below the number of active vnodes -- the system will try to reduce 1401 * numvnodes to match, but should fail, so the subtraction below should 1402 * not overflow. 1403 */ 1404 void 1405 getnewvnode_drop_reserve(void) 1406 { 1407 struct thread *td; 1408 1409 td = curthread; 1410 atomic_subtract_long(&numvnodes, td->td_vp_reserv); 1411 td->td_vp_reserv = 0; 1412 } 1413 1414 /* 1415 * Return the next vnode from the free list. 1416 */ 1417 int 1418 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1419 struct vnode **vpp) 1420 { 1421 struct vnode *vp; 1422 struct thread *td; 1423 struct lock_object *lo; 1424 static int cyclecount; 1425 int error __unused; 1426 1427 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1428 vp = NULL; 1429 td = curthread; 1430 if (td->td_vp_reserv > 0) { 1431 td->td_vp_reserv -= 1; 1432 goto alloc; 1433 } 1434 mtx_lock(&vnode_free_list_mtx); 1435 if (numvnodes < desiredvnodes) 1436 cyclecount = 0; 1437 else if (cyclecount++ >= freevnodes) { 1438 cyclecount = 0; 1439 vstir = 1; 1440 } 1441 /* 1442 * Grow the vnode cache if it will not be above its target max 1443 * after growing. Otherwise, if the free list is nonempty, try 1444 * to reclaim 1 item from it before growing the cache (possibly 1445 * above its target max if the reclamation failed or is delayed). 1446 * Otherwise, wait for some space. In all cases, schedule 1447 * vnlru_proc() if we are getting short of space. The watermarks 1448 * should be chosen so that we never wait or even reclaim from 1449 * the free list to below its target minimum. 1450 */ 1451 if (numvnodes + 1 <= desiredvnodes) 1452 ; 1453 else if (freevnodes > 0) 1454 vnlru_free_locked(1, NULL); 1455 else { 1456 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag & 1457 MNTK_SUSPEND)); 1458 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 1459 if (error != 0) { 1460 mtx_unlock(&vnode_free_list_mtx); 1461 return (error); 1462 } 1463 #endif 1464 } 1465 vcheckspace(); 1466 atomic_add_long(&numvnodes, 1); 1467 mtx_unlock(&vnode_free_list_mtx); 1468 alloc: 1469 counter_u64_add(vnodes_created, 1); 1470 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 1471 /* 1472 * Locks are given the generic name "vnode" when created. 1473 * Follow the historic practice of using the filesystem 1474 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1475 * 1476 * Locks live in a witness group keyed on their name. Thus, 1477 * when a lock is renamed, it must also move from the witness 1478 * group of its old name to the witness group of its new name. 1479 * 1480 * The change only needs to be made when the vnode moves 1481 * from one filesystem type to another. We ensure that each 1482 * filesystem use a single static name pointer for its tag so 1483 * that we can compare pointers rather than doing a strcmp(). 1484 */ 1485 lo = &vp->v_vnlock->lock_object; 1486 if (lo->lo_name != tag) { 1487 lo->lo_name = tag; 1488 WITNESS_DESTROY(lo); 1489 WITNESS_INIT(lo, tag); 1490 } 1491 /* 1492 * By default, don't allow shared locks unless filesystems opt-in. 1493 */ 1494 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1495 /* 1496 * Finalize various vnode identity bits. 1497 */ 1498 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1499 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1500 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1501 vp->v_type = VNON; 1502 vp->v_tag = tag; 1503 vp->v_op = vops; 1504 v_init_counters(vp); 1505 vp->v_bufobj.bo_ops = &buf_ops_bio; 1506 #ifdef DIAGNOSTIC 1507 if (mp == NULL && vops != &dead_vnodeops) 1508 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1509 #endif 1510 #ifdef MAC 1511 mac_vnode_init(vp); 1512 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1513 mac_vnode_associate_singlelabel(mp, vp); 1514 #endif 1515 if (mp != NULL) { 1516 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1517 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1518 vp->v_vflag |= VV_NOKNOTE; 1519 } 1520 1521 /* 1522 * For the filesystems which do not use vfs_hash_insert(), 1523 * still initialize v_hash to have vfs_hash_index() useful. 1524 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1525 * its own hashing. 1526 */ 1527 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1528 1529 *vpp = vp; 1530 return (0); 1531 } 1532 1533 /* 1534 * Delete from old mount point vnode list, if on one. 1535 */ 1536 static void 1537 delmntque(struct vnode *vp) 1538 { 1539 struct mount *mp; 1540 int active; 1541 1542 mp = vp->v_mount; 1543 if (mp == NULL) 1544 return; 1545 MNT_ILOCK(mp); 1546 VI_LOCK(vp); 1547 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize, 1548 ("Active vnode list size %d > Vnode list size %d", 1549 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize)); 1550 active = vp->v_iflag & VI_ACTIVE; 1551 vp->v_iflag &= ~VI_ACTIVE; 1552 if (active) { 1553 mtx_lock(&mp->mnt_listmtx); 1554 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); 1555 mp->mnt_activevnodelistsize--; 1556 mtx_unlock(&mp->mnt_listmtx); 1557 } 1558 vp->v_mount = NULL; 1559 VI_UNLOCK(vp); 1560 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1561 ("bad mount point vnode list size")); 1562 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1563 mp->mnt_nvnodelistsize--; 1564 MNT_REL(mp); 1565 MNT_IUNLOCK(mp); 1566 } 1567 1568 static void 1569 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1570 { 1571 1572 vp->v_data = NULL; 1573 vp->v_op = &dead_vnodeops; 1574 vgone(vp); 1575 vput(vp); 1576 } 1577 1578 /* 1579 * Insert into list of vnodes for the new mount point, if available. 1580 */ 1581 int 1582 insmntque1(struct vnode *vp, struct mount *mp, 1583 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1584 { 1585 1586 KASSERT(vp->v_mount == NULL, 1587 ("insmntque: vnode already on per mount vnode list")); 1588 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1589 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1590 1591 /* 1592 * We acquire the vnode interlock early to ensure that the 1593 * vnode cannot be recycled by another process releasing a 1594 * holdcnt on it before we get it on both the vnode list 1595 * and the active vnode list. The mount mutex protects only 1596 * manipulation of the vnode list and the vnode freelist 1597 * mutex protects only manipulation of the active vnode list. 1598 * Hence the need to hold the vnode interlock throughout. 1599 */ 1600 MNT_ILOCK(mp); 1601 VI_LOCK(vp); 1602 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1603 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1604 mp->mnt_nvnodelistsize == 0)) && 1605 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1606 VI_UNLOCK(vp); 1607 MNT_IUNLOCK(mp); 1608 if (dtr != NULL) 1609 dtr(vp, dtr_arg); 1610 return (EBUSY); 1611 } 1612 vp->v_mount = mp; 1613 MNT_REF(mp); 1614 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1615 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1616 ("neg mount point vnode list size")); 1617 mp->mnt_nvnodelistsize++; 1618 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1619 ("Activating already active vnode")); 1620 vp->v_iflag |= VI_ACTIVE; 1621 mtx_lock(&mp->mnt_listmtx); 1622 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 1623 mp->mnt_activevnodelistsize++; 1624 mtx_unlock(&mp->mnt_listmtx); 1625 VI_UNLOCK(vp); 1626 MNT_IUNLOCK(mp); 1627 return (0); 1628 } 1629 1630 int 1631 insmntque(struct vnode *vp, struct mount *mp) 1632 { 1633 1634 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1635 } 1636 1637 /* 1638 * Flush out and invalidate all buffers associated with a bufobj 1639 * Called with the underlying object locked. 1640 */ 1641 int 1642 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1643 { 1644 int error; 1645 1646 BO_LOCK(bo); 1647 if (flags & V_SAVE) { 1648 error = bufobj_wwait(bo, slpflag, slptimeo); 1649 if (error) { 1650 BO_UNLOCK(bo); 1651 return (error); 1652 } 1653 if (bo->bo_dirty.bv_cnt > 0) { 1654 BO_UNLOCK(bo); 1655 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1656 return (error); 1657 /* 1658 * XXX We could save a lock/unlock if this was only 1659 * enabled under INVARIANTS 1660 */ 1661 BO_LOCK(bo); 1662 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1663 panic("vinvalbuf: dirty bufs"); 1664 } 1665 } 1666 /* 1667 * If you alter this loop please notice that interlock is dropped and 1668 * reacquired in flushbuflist. Special care is needed to ensure that 1669 * no race conditions occur from this. 1670 */ 1671 do { 1672 error = flushbuflist(&bo->bo_clean, 1673 flags, bo, slpflag, slptimeo); 1674 if (error == 0 && !(flags & V_CLEANONLY)) 1675 error = flushbuflist(&bo->bo_dirty, 1676 flags, bo, slpflag, slptimeo); 1677 if (error != 0 && error != EAGAIN) { 1678 BO_UNLOCK(bo); 1679 return (error); 1680 } 1681 } while (error != 0); 1682 1683 /* 1684 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1685 * have write I/O in-progress but if there is a VM object then the 1686 * VM object can also have read-I/O in-progress. 1687 */ 1688 do { 1689 bufobj_wwait(bo, 0, 0); 1690 if ((flags & V_VMIO) == 0) { 1691 BO_UNLOCK(bo); 1692 if (bo->bo_object != NULL) { 1693 VM_OBJECT_WLOCK(bo->bo_object); 1694 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1695 VM_OBJECT_WUNLOCK(bo->bo_object); 1696 } 1697 BO_LOCK(bo); 1698 } 1699 } while (bo->bo_numoutput > 0); 1700 BO_UNLOCK(bo); 1701 1702 /* 1703 * Destroy the copy in the VM cache, too. 1704 */ 1705 if (bo->bo_object != NULL && 1706 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1707 VM_OBJECT_WLOCK(bo->bo_object); 1708 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1709 OBJPR_CLEANONLY : 0); 1710 VM_OBJECT_WUNLOCK(bo->bo_object); 1711 } 1712 1713 #ifdef INVARIANTS 1714 BO_LOCK(bo); 1715 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1716 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1717 bo->bo_clean.bv_cnt > 0)) 1718 panic("vinvalbuf: flush failed"); 1719 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1720 bo->bo_dirty.bv_cnt > 0) 1721 panic("vinvalbuf: flush dirty failed"); 1722 BO_UNLOCK(bo); 1723 #endif 1724 return (0); 1725 } 1726 1727 /* 1728 * Flush out and invalidate all buffers associated with a vnode. 1729 * Called with the underlying object locked. 1730 */ 1731 int 1732 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1733 { 1734 1735 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1736 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1737 if (vp->v_object != NULL && vp->v_object->handle != vp) 1738 return (0); 1739 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1740 } 1741 1742 /* 1743 * Flush out buffers on the specified list. 1744 * 1745 */ 1746 static int 1747 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1748 int slptimeo) 1749 { 1750 struct buf *bp, *nbp; 1751 int retval, error; 1752 daddr_t lblkno; 1753 b_xflags_t xflags; 1754 1755 ASSERT_BO_WLOCKED(bo); 1756 1757 retval = 0; 1758 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1759 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1760 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1761 continue; 1762 } 1763 if (nbp != NULL) { 1764 lblkno = nbp->b_lblkno; 1765 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1766 } 1767 retval = EAGAIN; 1768 error = BUF_TIMELOCK(bp, 1769 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1770 "flushbuf", slpflag, slptimeo); 1771 if (error) { 1772 BO_LOCK(bo); 1773 return (error != ENOLCK ? error : EAGAIN); 1774 } 1775 KASSERT(bp->b_bufobj == bo, 1776 ("bp %p wrong b_bufobj %p should be %p", 1777 bp, bp->b_bufobj, bo)); 1778 /* 1779 * XXX Since there are no node locks for NFS, I 1780 * believe there is a slight chance that a delayed 1781 * write will occur while sleeping just above, so 1782 * check for it. 1783 */ 1784 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1785 (flags & V_SAVE)) { 1786 bremfree(bp); 1787 bp->b_flags |= B_ASYNC; 1788 bwrite(bp); 1789 BO_LOCK(bo); 1790 return (EAGAIN); /* XXX: why not loop ? */ 1791 } 1792 bremfree(bp); 1793 bp->b_flags |= (B_INVAL | B_RELBUF); 1794 bp->b_flags &= ~B_ASYNC; 1795 brelse(bp); 1796 BO_LOCK(bo); 1797 if (nbp == NULL) 1798 break; 1799 nbp = gbincore(bo, lblkno); 1800 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1801 != xflags) 1802 break; /* nbp invalid */ 1803 } 1804 return (retval); 1805 } 1806 1807 int 1808 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 1809 { 1810 struct buf *bp; 1811 int error; 1812 daddr_t lblkno; 1813 1814 ASSERT_BO_LOCKED(bo); 1815 1816 for (lblkno = startn;;) { 1817 again: 1818 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 1819 if (bp == NULL || bp->b_lblkno >= endn || 1820 bp->b_lblkno < startn) 1821 break; 1822 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 1823 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 1824 if (error != 0) { 1825 BO_RLOCK(bo); 1826 if (error == ENOLCK) 1827 goto again; 1828 return (error); 1829 } 1830 KASSERT(bp->b_bufobj == bo, 1831 ("bp %p wrong b_bufobj %p should be %p", 1832 bp, bp->b_bufobj, bo)); 1833 lblkno = bp->b_lblkno + 1; 1834 if ((bp->b_flags & B_MANAGED) == 0) 1835 bremfree(bp); 1836 bp->b_flags |= B_RELBUF; 1837 /* 1838 * In the VMIO case, use the B_NOREUSE flag to hint that the 1839 * pages backing each buffer in the range are unlikely to be 1840 * reused. Dirty buffers will have the hint applied once 1841 * they've been written. 1842 */ 1843 if (bp->b_vp->v_object != NULL) 1844 bp->b_flags |= B_NOREUSE; 1845 brelse(bp); 1846 BO_RLOCK(bo); 1847 } 1848 return (0); 1849 } 1850 1851 /* 1852 * Truncate a file's buffer and pages to a specified length. This 1853 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1854 * sync activity. 1855 */ 1856 int 1857 vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize) 1858 { 1859 struct buf *bp, *nbp; 1860 int anyfreed; 1861 int trunclbn; 1862 struct bufobj *bo; 1863 1864 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__, 1865 vp, cred, blksize, (uintmax_t)length); 1866 1867 /* 1868 * Round up to the *next* lbn. 1869 */ 1870 trunclbn = howmany(length, blksize); 1871 1872 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1873 restart: 1874 bo = &vp->v_bufobj; 1875 BO_LOCK(bo); 1876 anyfreed = 1; 1877 for (;anyfreed;) { 1878 anyfreed = 0; 1879 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1880 if (bp->b_lblkno < trunclbn) 1881 continue; 1882 if (BUF_LOCK(bp, 1883 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1884 BO_LOCKPTR(bo)) == ENOLCK) 1885 goto restart; 1886 1887 bremfree(bp); 1888 bp->b_flags |= (B_INVAL | B_RELBUF); 1889 bp->b_flags &= ~B_ASYNC; 1890 brelse(bp); 1891 anyfreed = 1; 1892 1893 BO_LOCK(bo); 1894 if (nbp != NULL && 1895 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1896 (nbp->b_vp != vp) || 1897 (nbp->b_flags & B_DELWRI))) { 1898 BO_UNLOCK(bo); 1899 goto restart; 1900 } 1901 } 1902 1903 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1904 if (bp->b_lblkno < trunclbn) 1905 continue; 1906 if (BUF_LOCK(bp, 1907 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1908 BO_LOCKPTR(bo)) == ENOLCK) 1909 goto restart; 1910 bremfree(bp); 1911 bp->b_flags |= (B_INVAL | B_RELBUF); 1912 bp->b_flags &= ~B_ASYNC; 1913 brelse(bp); 1914 anyfreed = 1; 1915 1916 BO_LOCK(bo); 1917 if (nbp != NULL && 1918 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1919 (nbp->b_vp != vp) || 1920 (nbp->b_flags & B_DELWRI) == 0)) { 1921 BO_UNLOCK(bo); 1922 goto restart; 1923 } 1924 } 1925 } 1926 1927 if (length > 0) { 1928 restartsync: 1929 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1930 if (bp->b_lblkno > 0) 1931 continue; 1932 /* 1933 * Since we hold the vnode lock this should only 1934 * fail if we're racing with the buf daemon. 1935 */ 1936 if (BUF_LOCK(bp, 1937 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1938 BO_LOCKPTR(bo)) == ENOLCK) { 1939 goto restart; 1940 } 1941 VNASSERT((bp->b_flags & B_DELWRI), vp, 1942 ("buf(%p) on dirty queue without DELWRI", bp)); 1943 1944 bremfree(bp); 1945 bawrite(bp); 1946 BO_LOCK(bo); 1947 goto restartsync; 1948 } 1949 } 1950 1951 bufobj_wwait(bo, 0, 0); 1952 BO_UNLOCK(bo); 1953 vnode_pager_setsize(vp, length); 1954 1955 return (0); 1956 } 1957 1958 static void 1959 buf_vlist_remove(struct buf *bp) 1960 { 1961 struct bufv *bv; 1962 1963 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1964 ASSERT_BO_WLOCKED(bp->b_bufobj); 1965 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1966 (BX_VNDIRTY|BX_VNCLEAN), 1967 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1968 if (bp->b_xflags & BX_VNDIRTY) 1969 bv = &bp->b_bufobj->bo_dirty; 1970 else 1971 bv = &bp->b_bufobj->bo_clean; 1972 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 1973 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1974 bv->bv_cnt--; 1975 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1976 } 1977 1978 /* 1979 * Add the buffer to the sorted clean or dirty block list. 1980 * 1981 * NOTE: xflags is passed as a constant, optimizing this inline function! 1982 */ 1983 static void 1984 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1985 { 1986 struct bufv *bv; 1987 struct buf *n; 1988 int error; 1989 1990 ASSERT_BO_WLOCKED(bo); 1991 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 1992 ("dead bo %p", bo)); 1993 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1994 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1995 bp->b_xflags |= xflags; 1996 if (xflags & BX_VNDIRTY) 1997 bv = &bo->bo_dirty; 1998 else 1999 bv = &bo->bo_clean; 2000 2001 /* 2002 * Keep the list ordered. Optimize empty list insertion. Assume 2003 * we tend to grow at the tail so lookup_le should usually be cheaper 2004 * than _ge. 2005 */ 2006 if (bv->bv_cnt == 0 || 2007 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 2008 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 2009 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 2010 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 2011 else 2012 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2013 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2014 if (error) 2015 panic("buf_vlist_add: Preallocated nodes insufficient."); 2016 bv->bv_cnt++; 2017 } 2018 2019 /* 2020 * Look up a buffer using the buffer tries. 2021 */ 2022 struct buf * 2023 gbincore(struct bufobj *bo, daddr_t lblkno) 2024 { 2025 struct buf *bp; 2026 2027 ASSERT_BO_LOCKED(bo); 2028 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2029 if (bp != NULL) 2030 return (bp); 2031 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2032 } 2033 2034 /* 2035 * Associate a buffer with a vnode. 2036 */ 2037 void 2038 bgetvp(struct vnode *vp, struct buf *bp) 2039 { 2040 struct bufobj *bo; 2041 2042 bo = &vp->v_bufobj; 2043 ASSERT_BO_WLOCKED(bo); 2044 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2045 2046 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2047 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2048 ("bgetvp: bp already attached! %p", bp)); 2049 2050 vhold(vp); 2051 bp->b_vp = vp; 2052 bp->b_bufobj = bo; 2053 /* 2054 * Insert onto list for new vnode. 2055 */ 2056 buf_vlist_add(bp, bo, BX_VNCLEAN); 2057 } 2058 2059 /* 2060 * Disassociate a buffer from a vnode. 2061 */ 2062 void 2063 brelvp(struct buf *bp) 2064 { 2065 struct bufobj *bo; 2066 struct vnode *vp; 2067 2068 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2069 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2070 2071 /* 2072 * Delete from old vnode list, if on one. 2073 */ 2074 vp = bp->b_vp; /* XXX */ 2075 bo = bp->b_bufobj; 2076 BO_LOCK(bo); 2077 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2078 buf_vlist_remove(bp); 2079 else 2080 panic("brelvp: Buffer %p not on queue.", bp); 2081 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2082 bo->bo_flag &= ~BO_ONWORKLST; 2083 mtx_lock(&sync_mtx); 2084 LIST_REMOVE(bo, bo_synclist); 2085 syncer_worklist_len--; 2086 mtx_unlock(&sync_mtx); 2087 } 2088 bp->b_vp = NULL; 2089 bp->b_bufobj = NULL; 2090 BO_UNLOCK(bo); 2091 vdrop(vp); 2092 } 2093 2094 /* 2095 * Add an item to the syncer work queue. 2096 */ 2097 static void 2098 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2099 { 2100 int slot; 2101 2102 ASSERT_BO_WLOCKED(bo); 2103 2104 mtx_lock(&sync_mtx); 2105 if (bo->bo_flag & BO_ONWORKLST) 2106 LIST_REMOVE(bo, bo_synclist); 2107 else { 2108 bo->bo_flag |= BO_ONWORKLST; 2109 syncer_worklist_len++; 2110 } 2111 2112 if (delay > syncer_maxdelay - 2) 2113 delay = syncer_maxdelay - 2; 2114 slot = (syncer_delayno + delay) & syncer_mask; 2115 2116 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2117 mtx_unlock(&sync_mtx); 2118 } 2119 2120 static int 2121 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2122 { 2123 int error, len; 2124 2125 mtx_lock(&sync_mtx); 2126 len = syncer_worklist_len - sync_vnode_count; 2127 mtx_unlock(&sync_mtx); 2128 error = SYSCTL_OUT(req, &len, sizeof(len)); 2129 return (error); 2130 } 2131 2132 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 2133 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2134 2135 static struct proc *updateproc; 2136 static void sched_sync(void); 2137 static struct kproc_desc up_kp = { 2138 "syncer", 2139 sched_sync, 2140 &updateproc 2141 }; 2142 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2143 2144 static int 2145 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2146 { 2147 struct vnode *vp; 2148 struct mount *mp; 2149 2150 *bo = LIST_FIRST(slp); 2151 if (*bo == NULL) 2152 return (0); 2153 vp = bo2vnode(*bo); 2154 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2155 return (1); 2156 /* 2157 * We use vhold in case the vnode does not 2158 * successfully sync. vhold prevents the vnode from 2159 * going away when we unlock the sync_mtx so that 2160 * we can acquire the vnode interlock. 2161 */ 2162 vholdl(vp); 2163 mtx_unlock(&sync_mtx); 2164 VI_UNLOCK(vp); 2165 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2166 vdrop(vp); 2167 mtx_lock(&sync_mtx); 2168 return (*bo == LIST_FIRST(slp)); 2169 } 2170 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2171 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2172 VOP_UNLOCK(vp, 0); 2173 vn_finished_write(mp); 2174 BO_LOCK(*bo); 2175 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2176 /* 2177 * Put us back on the worklist. The worklist 2178 * routine will remove us from our current 2179 * position and then add us back in at a later 2180 * position. 2181 */ 2182 vn_syncer_add_to_worklist(*bo, syncdelay); 2183 } 2184 BO_UNLOCK(*bo); 2185 vdrop(vp); 2186 mtx_lock(&sync_mtx); 2187 return (0); 2188 } 2189 2190 static int first_printf = 1; 2191 2192 /* 2193 * System filesystem synchronizer daemon. 2194 */ 2195 static void 2196 sched_sync(void) 2197 { 2198 struct synclist *next, *slp; 2199 struct bufobj *bo; 2200 long starttime; 2201 struct thread *td = curthread; 2202 int last_work_seen; 2203 int net_worklist_len; 2204 int syncer_final_iter; 2205 int error; 2206 2207 last_work_seen = 0; 2208 syncer_final_iter = 0; 2209 syncer_state = SYNCER_RUNNING; 2210 starttime = time_uptime; 2211 td->td_pflags |= TDP_NORUNNINGBUF; 2212 2213 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2214 SHUTDOWN_PRI_LAST); 2215 2216 mtx_lock(&sync_mtx); 2217 for (;;) { 2218 if (syncer_state == SYNCER_FINAL_DELAY && 2219 syncer_final_iter == 0) { 2220 mtx_unlock(&sync_mtx); 2221 kproc_suspend_check(td->td_proc); 2222 mtx_lock(&sync_mtx); 2223 } 2224 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2225 if (syncer_state != SYNCER_RUNNING && 2226 starttime != time_uptime) { 2227 if (first_printf) { 2228 printf("\nSyncing disks, vnodes remaining... "); 2229 first_printf = 0; 2230 } 2231 printf("%d ", net_worklist_len); 2232 } 2233 starttime = time_uptime; 2234 2235 /* 2236 * Push files whose dirty time has expired. Be careful 2237 * of interrupt race on slp queue. 2238 * 2239 * Skip over empty worklist slots when shutting down. 2240 */ 2241 do { 2242 slp = &syncer_workitem_pending[syncer_delayno]; 2243 syncer_delayno += 1; 2244 if (syncer_delayno == syncer_maxdelay) 2245 syncer_delayno = 0; 2246 next = &syncer_workitem_pending[syncer_delayno]; 2247 /* 2248 * If the worklist has wrapped since the 2249 * it was emptied of all but syncer vnodes, 2250 * switch to the FINAL_DELAY state and run 2251 * for one more second. 2252 */ 2253 if (syncer_state == SYNCER_SHUTTING_DOWN && 2254 net_worklist_len == 0 && 2255 last_work_seen == syncer_delayno) { 2256 syncer_state = SYNCER_FINAL_DELAY; 2257 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2258 } 2259 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2260 syncer_worklist_len > 0); 2261 2262 /* 2263 * Keep track of the last time there was anything 2264 * on the worklist other than syncer vnodes. 2265 * Return to the SHUTTING_DOWN state if any 2266 * new work appears. 2267 */ 2268 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2269 last_work_seen = syncer_delayno; 2270 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2271 syncer_state = SYNCER_SHUTTING_DOWN; 2272 while (!LIST_EMPTY(slp)) { 2273 error = sync_vnode(slp, &bo, td); 2274 if (error == 1) { 2275 LIST_REMOVE(bo, bo_synclist); 2276 LIST_INSERT_HEAD(next, bo, bo_synclist); 2277 continue; 2278 } 2279 2280 if (first_printf == 0) { 2281 /* 2282 * Drop the sync mutex, because some watchdog 2283 * drivers need to sleep while patting 2284 */ 2285 mtx_unlock(&sync_mtx); 2286 wdog_kern_pat(WD_LASTVAL); 2287 mtx_lock(&sync_mtx); 2288 } 2289 2290 } 2291 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2292 syncer_final_iter--; 2293 /* 2294 * The variable rushjob allows the kernel to speed up the 2295 * processing of the filesystem syncer process. A rushjob 2296 * value of N tells the filesystem syncer to process the next 2297 * N seconds worth of work on its queue ASAP. Currently rushjob 2298 * is used by the soft update code to speed up the filesystem 2299 * syncer process when the incore state is getting so far 2300 * ahead of the disk that the kernel memory pool is being 2301 * threatened with exhaustion. 2302 */ 2303 if (rushjob > 0) { 2304 rushjob -= 1; 2305 continue; 2306 } 2307 /* 2308 * Just sleep for a short period of time between 2309 * iterations when shutting down to allow some I/O 2310 * to happen. 2311 * 2312 * If it has taken us less than a second to process the 2313 * current work, then wait. Otherwise start right over 2314 * again. We can still lose time if any single round 2315 * takes more than two seconds, but it does not really 2316 * matter as we are just trying to generally pace the 2317 * filesystem activity. 2318 */ 2319 if (syncer_state != SYNCER_RUNNING || 2320 time_uptime == starttime) { 2321 thread_lock(td); 2322 sched_prio(td, PPAUSE); 2323 thread_unlock(td); 2324 } 2325 if (syncer_state != SYNCER_RUNNING) 2326 cv_timedwait(&sync_wakeup, &sync_mtx, 2327 hz / SYNCER_SHUTDOWN_SPEEDUP); 2328 else if (time_uptime == starttime) 2329 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2330 } 2331 } 2332 2333 /* 2334 * Request the syncer daemon to speed up its work. 2335 * We never push it to speed up more than half of its 2336 * normal turn time, otherwise it could take over the cpu. 2337 */ 2338 int 2339 speedup_syncer(void) 2340 { 2341 int ret = 0; 2342 2343 mtx_lock(&sync_mtx); 2344 if (rushjob < syncdelay / 2) { 2345 rushjob += 1; 2346 stat_rush_requests += 1; 2347 ret = 1; 2348 } 2349 mtx_unlock(&sync_mtx); 2350 cv_broadcast(&sync_wakeup); 2351 return (ret); 2352 } 2353 2354 /* 2355 * Tell the syncer to speed up its work and run though its work 2356 * list several times, then tell it to shut down. 2357 */ 2358 static void 2359 syncer_shutdown(void *arg, int howto) 2360 { 2361 2362 if (howto & RB_NOSYNC) 2363 return; 2364 mtx_lock(&sync_mtx); 2365 syncer_state = SYNCER_SHUTTING_DOWN; 2366 rushjob = 0; 2367 mtx_unlock(&sync_mtx); 2368 cv_broadcast(&sync_wakeup); 2369 kproc_shutdown(arg, howto); 2370 } 2371 2372 void 2373 syncer_suspend(void) 2374 { 2375 2376 syncer_shutdown(updateproc, 0); 2377 } 2378 2379 void 2380 syncer_resume(void) 2381 { 2382 2383 mtx_lock(&sync_mtx); 2384 first_printf = 1; 2385 syncer_state = SYNCER_RUNNING; 2386 mtx_unlock(&sync_mtx); 2387 cv_broadcast(&sync_wakeup); 2388 kproc_resume(updateproc); 2389 } 2390 2391 /* 2392 * Reassign a buffer from one vnode to another. 2393 * Used to assign file specific control information 2394 * (indirect blocks) to the vnode to which they belong. 2395 */ 2396 void 2397 reassignbuf(struct buf *bp) 2398 { 2399 struct vnode *vp; 2400 struct bufobj *bo; 2401 int delay; 2402 #ifdef INVARIANTS 2403 struct bufv *bv; 2404 #endif 2405 2406 vp = bp->b_vp; 2407 bo = bp->b_bufobj; 2408 ++reassignbufcalls; 2409 2410 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2411 bp, bp->b_vp, bp->b_flags); 2412 /* 2413 * B_PAGING flagged buffers cannot be reassigned because their vp 2414 * is not fully linked in. 2415 */ 2416 if (bp->b_flags & B_PAGING) 2417 panic("cannot reassign paging buffer"); 2418 2419 /* 2420 * Delete from old vnode list, if on one. 2421 */ 2422 BO_LOCK(bo); 2423 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2424 buf_vlist_remove(bp); 2425 else 2426 panic("reassignbuf: Buffer %p not on queue.", bp); 2427 /* 2428 * If dirty, put on list of dirty buffers; otherwise insert onto list 2429 * of clean buffers. 2430 */ 2431 if (bp->b_flags & B_DELWRI) { 2432 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2433 switch (vp->v_type) { 2434 case VDIR: 2435 delay = dirdelay; 2436 break; 2437 case VCHR: 2438 delay = metadelay; 2439 break; 2440 default: 2441 delay = filedelay; 2442 } 2443 vn_syncer_add_to_worklist(bo, delay); 2444 } 2445 buf_vlist_add(bp, bo, BX_VNDIRTY); 2446 } else { 2447 buf_vlist_add(bp, bo, BX_VNCLEAN); 2448 2449 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2450 mtx_lock(&sync_mtx); 2451 LIST_REMOVE(bo, bo_synclist); 2452 syncer_worklist_len--; 2453 mtx_unlock(&sync_mtx); 2454 bo->bo_flag &= ~BO_ONWORKLST; 2455 } 2456 } 2457 #ifdef INVARIANTS 2458 bv = &bo->bo_clean; 2459 bp = TAILQ_FIRST(&bv->bv_hd); 2460 KASSERT(bp == NULL || bp->b_bufobj == bo, 2461 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2462 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2463 KASSERT(bp == NULL || bp->b_bufobj == bo, 2464 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2465 bv = &bo->bo_dirty; 2466 bp = TAILQ_FIRST(&bv->bv_hd); 2467 KASSERT(bp == NULL || bp->b_bufobj == bo, 2468 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2469 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2470 KASSERT(bp == NULL || bp->b_bufobj == bo, 2471 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2472 #endif 2473 BO_UNLOCK(bo); 2474 } 2475 2476 static void 2477 v_init_counters(struct vnode *vp) 2478 { 2479 2480 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2481 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2482 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2483 2484 refcount_init(&vp->v_holdcnt, 1); 2485 refcount_init(&vp->v_usecount, 1); 2486 } 2487 2488 static void 2489 v_incr_usecount_locked(struct vnode *vp) 2490 { 2491 2492 ASSERT_VI_LOCKED(vp, __func__); 2493 if ((vp->v_iflag & VI_OWEINACT) != 0) { 2494 VNASSERT(vp->v_usecount == 0, vp, 2495 ("vnode with usecount and VI_OWEINACT set")); 2496 vp->v_iflag &= ~VI_OWEINACT; 2497 } 2498 refcount_acquire(&vp->v_usecount); 2499 v_incr_devcount(vp); 2500 } 2501 2502 /* 2503 * Increment the use count on the vnode, taking care to reference 2504 * the driver's usecount if this is a chardev. 2505 */ 2506 static void 2507 v_incr_usecount(struct vnode *vp) 2508 { 2509 2510 ASSERT_VI_UNLOCKED(vp, __func__); 2511 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2512 2513 if (vp->v_type != VCHR && 2514 refcount_acquire_if_not_zero(&vp->v_usecount)) { 2515 VNODE_REFCOUNT_FENCE_ACQ(); 2516 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2517 ("vnode with usecount and VI_OWEINACT set")); 2518 } else { 2519 VI_LOCK(vp); 2520 v_incr_usecount_locked(vp); 2521 VI_UNLOCK(vp); 2522 } 2523 } 2524 2525 /* 2526 * Increment si_usecount of the associated device, if any. 2527 */ 2528 static void 2529 v_incr_devcount(struct vnode *vp) 2530 { 2531 2532 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2533 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2534 dev_lock(); 2535 vp->v_rdev->si_usecount++; 2536 dev_unlock(); 2537 } 2538 } 2539 2540 /* 2541 * Decrement si_usecount of the associated device, if any. 2542 */ 2543 static void 2544 v_decr_devcount(struct vnode *vp) 2545 { 2546 2547 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2548 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2549 dev_lock(); 2550 vp->v_rdev->si_usecount--; 2551 dev_unlock(); 2552 } 2553 } 2554 2555 /* 2556 * Grab a particular vnode from the free list, increment its 2557 * reference count and lock it. VI_DOOMED is set if the vnode 2558 * is being destroyed. Only callers who specify LK_RETRY will 2559 * see doomed vnodes. If inactive processing was delayed in 2560 * vput try to do it here. 2561 * 2562 * Notes on lockless counter manipulation: 2563 * _vhold, vputx and other routines make various decisions based 2564 * on either holdcnt or usecount being 0. As long as either counter 2565 * is not transitioning 0->1 nor 1->0, the manipulation can be done 2566 * with atomic operations. Otherwise the interlock is taken covering 2567 * both the atomic and additional actions. 2568 */ 2569 int 2570 vget(struct vnode *vp, int flags, struct thread *td) 2571 { 2572 int error, oweinact; 2573 2574 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2575 ("vget: invalid lock operation")); 2576 2577 if ((flags & LK_INTERLOCK) != 0) 2578 ASSERT_VI_LOCKED(vp, __func__); 2579 else 2580 ASSERT_VI_UNLOCKED(vp, __func__); 2581 if ((flags & LK_VNHELD) != 0) 2582 VNASSERT((vp->v_holdcnt > 0), vp, 2583 ("vget: LK_VNHELD passed but vnode not held")); 2584 2585 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2586 2587 if ((flags & LK_VNHELD) == 0) 2588 _vhold(vp, (flags & LK_INTERLOCK) != 0); 2589 2590 if ((error = vn_lock(vp, flags)) != 0) { 2591 vdrop(vp); 2592 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2593 vp); 2594 return (error); 2595 } 2596 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2597 panic("vget: vn_lock failed to return ENOENT\n"); 2598 /* 2599 * We don't guarantee that any particular close will 2600 * trigger inactive processing so just make a best effort 2601 * here at preventing a reference to a removed file. If 2602 * we don't succeed no harm is done. 2603 * 2604 * Upgrade our holdcnt to a usecount. 2605 */ 2606 if (vp->v_type == VCHR || 2607 !refcount_acquire_if_not_zero(&vp->v_usecount)) { 2608 VI_LOCK(vp); 2609 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2610 oweinact = 0; 2611 } else { 2612 oweinact = 1; 2613 vp->v_iflag &= ~VI_OWEINACT; 2614 VNODE_REFCOUNT_FENCE_REL(); 2615 } 2616 refcount_acquire(&vp->v_usecount); 2617 v_incr_devcount(vp); 2618 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2619 (flags & LK_NOWAIT) == 0) 2620 vinactive(vp, td); 2621 VI_UNLOCK(vp); 2622 } 2623 return (0); 2624 } 2625 2626 /* 2627 * Increase the reference (use) and hold count of a vnode. 2628 * This will also remove the vnode from the free list if it is presently free. 2629 */ 2630 void 2631 vref(struct vnode *vp) 2632 { 2633 2634 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2635 _vhold(vp, false); 2636 v_incr_usecount(vp); 2637 } 2638 2639 void 2640 vrefl(struct vnode *vp) 2641 { 2642 2643 ASSERT_VI_LOCKED(vp, __func__); 2644 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2645 _vhold(vp, true); 2646 v_incr_usecount_locked(vp); 2647 } 2648 2649 void 2650 vrefact(struct vnode *vp) 2651 { 2652 2653 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2654 if (__predict_false(vp->v_type == VCHR)) { 2655 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 2656 ("%s: wrong ref counts", __func__)); 2657 vref(vp); 2658 return; 2659 } 2660 #ifdef INVARIANTS 2661 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 2662 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__)); 2663 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2664 VNASSERT(old > 0, vp, ("%s: wrong use count", __func__)); 2665 #else 2666 refcount_acquire(&vp->v_holdcnt); 2667 refcount_acquire(&vp->v_usecount); 2668 #endif 2669 } 2670 2671 /* 2672 * Return reference count of a vnode. 2673 * 2674 * The results of this call are only guaranteed when some mechanism is used to 2675 * stop other processes from gaining references to the vnode. This may be the 2676 * case if the caller holds the only reference. This is also useful when stale 2677 * data is acceptable as race conditions may be accounted for by some other 2678 * means. 2679 */ 2680 int 2681 vrefcnt(struct vnode *vp) 2682 { 2683 2684 return (vp->v_usecount); 2685 } 2686 2687 #define VPUTX_VRELE 1 2688 #define VPUTX_VPUT 2 2689 #define VPUTX_VUNREF 3 2690 2691 /* 2692 * Decrement the use and hold counts for a vnode. 2693 * 2694 * See an explanation near vget() as to why atomic operation is safe. 2695 */ 2696 static void 2697 vputx(struct vnode *vp, int func) 2698 { 2699 int error; 2700 2701 KASSERT(vp != NULL, ("vputx: null vp")); 2702 if (func == VPUTX_VUNREF) 2703 ASSERT_VOP_LOCKED(vp, "vunref"); 2704 else if (func == VPUTX_VPUT) 2705 ASSERT_VOP_LOCKED(vp, "vput"); 2706 else 2707 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); 2708 ASSERT_VI_UNLOCKED(vp, __func__); 2709 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2710 2711 if (vp->v_type != VCHR && 2712 refcount_release_if_not_last(&vp->v_usecount)) { 2713 if (func == VPUTX_VPUT) 2714 VOP_UNLOCK(vp, 0); 2715 vdrop(vp); 2716 return; 2717 } 2718 2719 VI_LOCK(vp); 2720 2721 /* 2722 * We want to hold the vnode until the inactive finishes to 2723 * prevent vgone() races. We drop the use count here and the 2724 * hold count below when we're done. 2725 */ 2726 if (!refcount_release(&vp->v_usecount) || 2727 (vp->v_iflag & VI_DOINGINACT)) { 2728 if (func == VPUTX_VPUT) 2729 VOP_UNLOCK(vp, 0); 2730 v_decr_devcount(vp); 2731 vdropl(vp); 2732 return; 2733 } 2734 2735 v_decr_devcount(vp); 2736 2737 error = 0; 2738 2739 if (vp->v_usecount != 0) { 2740 vn_printf(vp, "vputx: usecount not zero for vnode "); 2741 panic("vputx: usecount not zero"); 2742 } 2743 2744 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); 2745 2746 /* 2747 * We must call VOP_INACTIVE with the node locked. Mark 2748 * as VI_DOINGINACT to avoid recursion. 2749 */ 2750 vp->v_iflag |= VI_OWEINACT; 2751 switch (func) { 2752 case VPUTX_VRELE: 2753 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2754 VI_LOCK(vp); 2755 break; 2756 case VPUTX_VPUT: 2757 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2758 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 2759 LK_NOWAIT); 2760 VI_LOCK(vp); 2761 } 2762 break; 2763 case VPUTX_VUNREF: 2764 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2765 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 2766 VI_LOCK(vp); 2767 } 2768 break; 2769 } 2770 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, 2771 ("vnode with usecount and VI_OWEINACT set")); 2772 if (error == 0) { 2773 if (vp->v_iflag & VI_OWEINACT) 2774 vinactive(vp, curthread); 2775 if (func != VPUTX_VUNREF) 2776 VOP_UNLOCK(vp, 0); 2777 } 2778 vdropl(vp); 2779 } 2780 2781 /* 2782 * Vnode put/release. 2783 * If count drops to zero, call inactive routine and return to freelist. 2784 */ 2785 void 2786 vrele(struct vnode *vp) 2787 { 2788 2789 vputx(vp, VPUTX_VRELE); 2790 } 2791 2792 /* 2793 * Release an already locked vnode. This give the same effects as 2794 * unlock+vrele(), but takes less time and avoids releasing and 2795 * re-aquiring the lock (as vrele() acquires the lock internally.) 2796 */ 2797 void 2798 vput(struct vnode *vp) 2799 { 2800 2801 vputx(vp, VPUTX_VPUT); 2802 } 2803 2804 /* 2805 * Release an exclusively locked vnode. Do not unlock the vnode lock. 2806 */ 2807 void 2808 vunref(struct vnode *vp) 2809 { 2810 2811 vputx(vp, VPUTX_VUNREF); 2812 } 2813 2814 /* 2815 * Increase the hold count and activate if this is the first reference. 2816 */ 2817 void 2818 _vhold(struct vnode *vp, bool locked) 2819 { 2820 struct mount *mp; 2821 2822 if (locked) 2823 ASSERT_VI_LOCKED(vp, __func__); 2824 else 2825 ASSERT_VI_UNLOCKED(vp, __func__); 2826 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2827 if (!locked) { 2828 if (refcount_acquire_if_not_zero(&vp->v_holdcnt)) { 2829 VNODE_REFCOUNT_FENCE_ACQ(); 2830 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2831 ("_vhold: vnode with holdcnt is free")); 2832 return; 2833 } 2834 VI_LOCK(vp); 2835 } 2836 if ((vp->v_iflag & VI_FREE) == 0) { 2837 refcount_acquire(&vp->v_holdcnt); 2838 if (!locked) 2839 VI_UNLOCK(vp); 2840 return; 2841 } 2842 VNASSERT(vp->v_holdcnt == 0, vp, 2843 ("%s: wrong hold count", __func__)); 2844 VNASSERT(vp->v_op != NULL, vp, 2845 ("%s: vnode already reclaimed.", __func__)); 2846 /* 2847 * Remove a vnode from the free list, mark it as in use, 2848 * and put it on the active list. 2849 */ 2850 VNASSERT(vp->v_mount != NULL, vp, 2851 ("_vhold: vnode not on per mount vnode list")); 2852 mp = vp->v_mount; 2853 mtx_lock(&mp->mnt_listmtx); 2854 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { 2855 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 2856 mp->mnt_tmpfreevnodelistsize--; 2857 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 2858 } else { 2859 mtx_lock(&vnode_free_list_mtx); 2860 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 2861 freevnodes--; 2862 mtx_unlock(&vnode_free_list_mtx); 2863 } 2864 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 2865 ("Activating already active vnode")); 2866 vp->v_iflag &= ~VI_FREE; 2867 vp->v_iflag |= VI_ACTIVE; 2868 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 2869 mp->mnt_activevnodelistsize++; 2870 mtx_unlock(&mp->mnt_listmtx); 2871 refcount_acquire(&vp->v_holdcnt); 2872 if (!locked) 2873 VI_UNLOCK(vp); 2874 } 2875 2876 /* 2877 * Drop the hold count of the vnode. If this is the last reference to 2878 * the vnode we place it on the free list unless it has been vgone'd 2879 * (marked VI_DOOMED) in which case we will free it. 2880 * 2881 * Because the vnode vm object keeps a hold reference on the vnode if 2882 * there is at least one resident non-cached page, the vnode cannot 2883 * leave the active list without the page cleanup done. 2884 */ 2885 void 2886 _vdrop(struct vnode *vp, bool locked) 2887 { 2888 struct bufobj *bo; 2889 struct mount *mp; 2890 int active; 2891 2892 if (locked) 2893 ASSERT_VI_LOCKED(vp, __func__); 2894 else 2895 ASSERT_VI_UNLOCKED(vp, __func__); 2896 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2897 if ((int)vp->v_holdcnt <= 0) 2898 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2899 if (!locked) { 2900 if (refcount_release_if_not_last(&vp->v_holdcnt)) 2901 return; 2902 VI_LOCK(vp); 2903 } 2904 if (refcount_release(&vp->v_holdcnt) == 0) { 2905 VI_UNLOCK(vp); 2906 return; 2907 } 2908 if ((vp->v_iflag & VI_DOOMED) == 0) { 2909 /* 2910 * Mark a vnode as free: remove it from its active list 2911 * and put it up for recycling on the freelist. 2912 */ 2913 VNASSERT(vp->v_op != NULL, vp, 2914 ("vdropl: vnode already reclaimed.")); 2915 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2916 ("vnode already free")); 2917 VNASSERT(vp->v_holdcnt == 0, vp, 2918 ("vdropl: freeing when we shouldn't")); 2919 active = vp->v_iflag & VI_ACTIVE; 2920 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2921 vp->v_iflag &= ~VI_ACTIVE; 2922 mp = vp->v_mount; 2923 if (mp != NULL) { 2924 mtx_lock(&mp->mnt_listmtx); 2925 if (active) { 2926 TAILQ_REMOVE(&mp->mnt_activevnodelist, 2927 vp, v_actfreelist); 2928 mp->mnt_activevnodelistsize--; 2929 } 2930 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, 2931 vp, v_actfreelist); 2932 mp->mnt_tmpfreevnodelistsize++; 2933 vp->v_iflag |= VI_FREE; 2934 vp->v_mflag |= VMP_TMPMNTFREELIST; 2935 VI_UNLOCK(vp); 2936 if (mp->mnt_tmpfreevnodelistsize >= 2937 mnt_free_list_batch) 2938 vnlru_return_batch_locked(mp); 2939 mtx_unlock(&mp->mnt_listmtx); 2940 } else { 2941 VNASSERT(active == 0, vp, 2942 ("vdropl: active vnode not on per mount " 2943 "vnode list")); 2944 mtx_lock(&vnode_free_list_mtx); 2945 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 2946 v_actfreelist); 2947 freevnodes++; 2948 vp->v_iflag |= VI_FREE; 2949 VI_UNLOCK(vp); 2950 mtx_unlock(&vnode_free_list_mtx); 2951 } 2952 } else { 2953 VI_UNLOCK(vp); 2954 counter_u64_add(free_owe_inact, 1); 2955 } 2956 return; 2957 } 2958 /* 2959 * The vnode has been marked for destruction, so free it. 2960 * 2961 * The vnode will be returned to the zone where it will 2962 * normally remain until it is needed for another vnode. We 2963 * need to cleanup (or verify that the cleanup has already 2964 * been done) any residual data left from its current use 2965 * so as not to contaminate the freshly allocated vnode. 2966 */ 2967 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 2968 atomic_subtract_long(&numvnodes, 1); 2969 bo = &vp->v_bufobj; 2970 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2971 ("cleaned vnode still on the free list.")); 2972 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 2973 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 2974 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 2975 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 2976 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 2977 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 2978 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 2979 ("clean blk trie not empty")); 2980 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 2981 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 2982 ("dirty blk trie not empty")); 2983 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 2984 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 2985 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 2986 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 2987 ("Dangling rangelock waiters")); 2988 VI_UNLOCK(vp); 2989 #ifdef MAC 2990 mac_vnode_destroy(vp); 2991 #endif 2992 if (vp->v_pollinfo != NULL) { 2993 destroy_vpollinfo(vp->v_pollinfo); 2994 vp->v_pollinfo = NULL; 2995 } 2996 #ifdef INVARIANTS 2997 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 2998 vp->v_op = NULL; 2999 #endif 3000 vp->v_mountedhere = NULL; 3001 vp->v_unpcb = NULL; 3002 vp->v_rdev = NULL; 3003 vp->v_fifoinfo = NULL; 3004 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 3005 vp->v_iflag = 0; 3006 vp->v_vflag = 0; 3007 bo->bo_flag = 0; 3008 uma_zfree(vnode_zone, vp); 3009 } 3010 3011 /* 3012 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3013 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3014 * OWEINACT tracks whether a vnode missed a call to inactive due to a 3015 * failed lock upgrade. 3016 */ 3017 void 3018 vinactive(struct vnode *vp, struct thread *td) 3019 { 3020 struct vm_object *obj; 3021 3022 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3023 ASSERT_VI_LOCKED(vp, "vinactive"); 3024 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3025 ("vinactive: recursed on VI_DOINGINACT")); 3026 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3027 vp->v_iflag |= VI_DOINGINACT; 3028 vp->v_iflag &= ~VI_OWEINACT; 3029 VI_UNLOCK(vp); 3030 /* 3031 * Before moving off the active list, we must be sure that any 3032 * modified pages are converted into the vnode's dirty 3033 * buffers, since these will no longer be checked once the 3034 * vnode is on the inactive list. 3035 * 3036 * The write-out of the dirty pages is asynchronous. At the 3037 * point that VOP_INACTIVE() is called, there could still be 3038 * pending I/O and dirty pages in the object. 3039 */ 3040 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3041 (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { 3042 VM_OBJECT_WLOCK(obj); 3043 vm_object_page_clean(obj, 0, 0, 0); 3044 VM_OBJECT_WUNLOCK(obj); 3045 } 3046 VOP_INACTIVE(vp, td); 3047 VI_LOCK(vp); 3048 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3049 ("vinactive: lost VI_DOINGINACT")); 3050 vp->v_iflag &= ~VI_DOINGINACT; 3051 } 3052 3053 /* 3054 * Remove any vnodes in the vnode table belonging to mount point mp. 3055 * 3056 * If FORCECLOSE is not specified, there should not be any active ones, 3057 * return error if any are found (nb: this is a user error, not a 3058 * system error). If FORCECLOSE is specified, detach any active vnodes 3059 * that are found. 3060 * 3061 * If WRITECLOSE is set, only flush out regular file vnodes open for 3062 * writing. 3063 * 3064 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3065 * 3066 * `rootrefs' specifies the base reference count for the root vnode 3067 * of this filesystem. The root vnode is considered busy if its 3068 * v_usecount exceeds this value. On a successful return, vflush(, td) 3069 * will call vrele() on the root vnode exactly rootrefs times. 3070 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3071 * be zero. 3072 */ 3073 #ifdef DIAGNOSTIC 3074 static int busyprt = 0; /* print out busy vnodes */ 3075 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3076 #endif 3077 3078 int 3079 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3080 { 3081 struct vnode *vp, *mvp, *rootvp = NULL; 3082 struct vattr vattr; 3083 int busy = 0, error; 3084 3085 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3086 rootrefs, flags); 3087 if (rootrefs > 0) { 3088 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3089 ("vflush: bad args")); 3090 /* 3091 * Get the filesystem root vnode. We can vput() it 3092 * immediately, since with rootrefs > 0, it won't go away. 3093 */ 3094 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3095 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3096 __func__, error); 3097 return (error); 3098 } 3099 vput(rootvp); 3100 } 3101 loop: 3102 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3103 vholdl(vp); 3104 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3105 if (error) { 3106 vdrop(vp); 3107 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3108 goto loop; 3109 } 3110 /* 3111 * Skip over a vnodes marked VV_SYSTEM. 3112 */ 3113 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3114 VOP_UNLOCK(vp, 0); 3115 vdrop(vp); 3116 continue; 3117 } 3118 /* 3119 * If WRITECLOSE is set, flush out unlinked but still open 3120 * files (even if open only for reading) and regular file 3121 * vnodes open for writing. 3122 */ 3123 if (flags & WRITECLOSE) { 3124 if (vp->v_object != NULL) { 3125 VM_OBJECT_WLOCK(vp->v_object); 3126 vm_object_page_clean(vp->v_object, 0, 0, 0); 3127 VM_OBJECT_WUNLOCK(vp->v_object); 3128 } 3129 error = VOP_FSYNC(vp, MNT_WAIT, td); 3130 if (error != 0) { 3131 VOP_UNLOCK(vp, 0); 3132 vdrop(vp); 3133 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3134 return (error); 3135 } 3136 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3137 VI_LOCK(vp); 3138 3139 if ((vp->v_type == VNON || 3140 (error == 0 && vattr.va_nlink > 0)) && 3141 (vp->v_writecount == 0 || vp->v_type != VREG)) { 3142 VOP_UNLOCK(vp, 0); 3143 vdropl(vp); 3144 continue; 3145 } 3146 } else 3147 VI_LOCK(vp); 3148 /* 3149 * With v_usecount == 0, all we need to do is clear out the 3150 * vnode data structures and we are done. 3151 * 3152 * If FORCECLOSE is set, forcibly close the vnode. 3153 */ 3154 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3155 vgonel(vp); 3156 } else { 3157 busy++; 3158 #ifdef DIAGNOSTIC 3159 if (busyprt) 3160 vn_printf(vp, "vflush: busy vnode "); 3161 #endif 3162 } 3163 VOP_UNLOCK(vp, 0); 3164 vdropl(vp); 3165 } 3166 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3167 /* 3168 * If just the root vnode is busy, and if its refcount 3169 * is equal to `rootrefs', then go ahead and kill it. 3170 */ 3171 VI_LOCK(rootvp); 3172 KASSERT(busy > 0, ("vflush: not busy")); 3173 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3174 ("vflush: usecount %d < rootrefs %d", 3175 rootvp->v_usecount, rootrefs)); 3176 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3177 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3178 vgone(rootvp); 3179 VOP_UNLOCK(rootvp, 0); 3180 busy = 0; 3181 } else 3182 VI_UNLOCK(rootvp); 3183 } 3184 if (busy) { 3185 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3186 busy); 3187 return (EBUSY); 3188 } 3189 for (; rootrefs > 0; rootrefs--) 3190 vrele(rootvp); 3191 return (0); 3192 } 3193 3194 /* 3195 * Recycle an unused vnode to the front of the free list. 3196 */ 3197 int 3198 vrecycle(struct vnode *vp) 3199 { 3200 int recycled; 3201 3202 VI_LOCK(vp); 3203 recycled = vrecyclel(vp); 3204 VI_UNLOCK(vp); 3205 return (recycled); 3206 } 3207 3208 /* 3209 * vrecycle, with the vp interlock held. 3210 */ 3211 int 3212 vrecyclel(struct vnode *vp) 3213 { 3214 int recycled; 3215 3216 ASSERT_VOP_ELOCKED(vp, __func__); 3217 ASSERT_VI_LOCKED(vp, __func__); 3218 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3219 recycled = 0; 3220 if (vp->v_usecount == 0) { 3221 recycled = 1; 3222 vgonel(vp); 3223 } 3224 return (recycled); 3225 } 3226 3227 /* 3228 * Eliminate all activity associated with a vnode 3229 * in preparation for reuse. 3230 */ 3231 void 3232 vgone(struct vnode *vp) 3233 { 3234 VI_LOCK(vp); 3235 vgonel(vp); 3236 VI_UNLOCK(vp); 3237 } 3238 3239 static void 3240 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3241 struct vnode *lowervp __unused) 3242 { 3243 } 3244 3245 /* 3246 * Notify upper mounts about reclaimed or unlinked vnode. 3247 */ 3248 void 3249 vfs_notify_upper(struct vnode *vp, int event) 3250 { 3251 static struct vfsops vgonel_vfsops = { 3252 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3253 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3254 }; 3255 struct mount *mp, *ump, *mmp; 3256 3257 mp = vp->v_mount; 3258 if (mp == NULL) 3259 return; 3260 3261 MNT_ILOCK(mp); 3262 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3263 goto unlock; 3264 MNT_IUNLOCK(mp); 3265 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3266 mmp->mnt_op = &vgonel_vfsops; 3267 mmp->mnt_kern_flag |= MNTK_MARKER; 3268 MNT_ILOCK(mp); 3269 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3270 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3271 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3272 ump = TAILQ_NEXT(ump, mnt_upper_link); 3273 continue; 3274 } 3275 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3276 MNT_IUNLOCK(mp); 3277 switch (event) { 3278 case VFS_NOTIFY_UPPER_RECLAIM: 3279 VFS_RECLAIM_LOWERVP(ump, vp); 3280 break; 3281 case VFS_NOTIFY_UPPER_UNLINK: 3282 VFS_UNLINK_LOWERVP(ump, vp); 3283 break; 3284 default: 3285 KASSERT(0, ("invalid event %d", event)); 3286 break; 3287 } 3288 MNT_ILOCK(mp); 3289 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3290 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3291 } 3292 free(mmp, M_TEMP); 3293 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3294 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3295 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3296 wakeup(&mp->mnt_uppers); 3297 } 3298 unlock: 3299 MNT_IUNLOCK(mp); 3300 } 3301 3302 /* 3303 * vgone, with the vp interlock held. 3304 */ 3305 static void 3306 vgonel(struct vnode *vp) 3307 { 3308 struct thread *td; 3309 int oweinact; 3310 int active; 3311 struct mount *mp; 3312 3313 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3314 ASSERT_VI_LOCKED(vp, "vgonel"); 3315 VNASSERT(vp->v_holdcnt, vp, 3316 ("vgonel: vp %p has no reference.", vp)); 3317 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3318 td = curthread; 3319 3320 /* 3321 * Don't vgonel if we're already doomed. 3322 */ 3323 if (vp->v_iflag & VI_DOOMED) 3324 return; 3325 vp->v_iflag |= VI_DOOMED; 3326 3327 /* 3328 * Check to see if the vnode is in use. If so, we have to call 3329 * VOP_CLOSE() and VOP_INACTIVE(). 3330 */ 3331 active = vp->v_usecount; 3332 oweinact = (vp->v_iflag & VI_OWEINACT); 3333 VI_UNLOCK(vp); 3334 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3335 3336 /* 3337 * If purging an active vnode, it must be closed and 3338 * deactivated before being reclaimed. 3339 */ 3340 if (active) 3341 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3342 if (oweinact || active) { 3343 VI_LOCK(vp); 3344 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3345 vinactive(vp, td); 3346 VI_UNLOCK(vp); 3347 } 3348 if (vp->v_type == VSOCK) 3349 vfs_unp_reclaim(vp); 3350 3351 /* 3352 * Clean out any buffers associated with the vnode. 3353 * If the flush fails, just toss the buffers. 3354 */ 3355 mp = NULL; 3356 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3357 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3358 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3359 while (vinvalbuf(vp, 0, 0, 0) != 0) 3360 ; 3361 } 3362 3363 BO_LOCK(&vp->v_bufobj); 3364 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3365 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3366 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3367 vp->v_bufobj.bo_clean.bv_cnt == 0, 3368 ("vp %p bufobj not invalidated", vp)); 3369 3370 /* 3371 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate() 3372 * after the object's page queue is flushed. 3373 */ 3374 if (vp->v_bufobj.bo_object == NULL) 3375 vp->v_bufobj.bo_flag |= BO_DEAD; 3376 BO_UNLOCK(&vp->v_bufobj); 3377 3378 /* 3379 * Reclaim the vnode. 3380 */ 3381 if (VOP_RECLAIM(vp, td)) 3382 panic("vgone: cannot reclaim"); 3383 if (mp != NULL) 3384 vn_finished_secondary_write(mp); 3385 VNASSERT(vp->v_object == NULL, vp, 3386 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3387 /* 3388 * Clear the advisory locks and wake up waiting threads. 3389 */ 3390 (void)VOP_ADVLOCKPURGE(vp); 3391 vp->v_lockf = NULL; 3392 /* 3393 * Delete from old mount point vnode list. 3394 */ 3395 delmntque(vp); 3396 cache_purge(vp); 3397 /* 3398 * Done with purge, reset to the standard lock and invalidate 3399 * the vnode. 3400 */ 3401 VI_LOCK(vp); 3402 vp->v_vnlock = &vp->v_lock; 3403 vp->v_op = &dead_vnodeops; 3404 vp->v_tag = "none"; 3405 vp->v_type = VBAD; 3406 } 3407 3408 /* 3409 * Calculate the total number of references to a special device. 3410 */ 3411 int 3412 vcount(struct vnode *vp) 3413 { 3414 int count; 3415 3416 dev_lock(); 3417 count = vp->v_rdev->si_usecount; 3418 dev_unlock(); 3419 return (count); 3420 } 3421 3422 /* 3423 * Same as above, but using the struct cdev *as argument 3424 */ 3425 int 3426 count_dev(struct cdev *dev) 3427 { 3428 int count; 3429 3430 dev_lock(); 3431 count = dev->si_usecount; 3432 dev_unlock(); 3433 return(count); 3434 } 3435 3436 /* 3437 * Print out a description of a vnode. 3438 */ 3439 static char *typename[] = 3440 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3441 "VMARKER"}; 3442 3443 void 3444 vn_printf(struct vnode *vp, const char *fmt, ...) 3445 { 3446 va_list ap; 3447 char buf[256], buf2[16]; 3448 u_long flags; 3449 3450 va_start(ap, fmt); 3451 vprintf(fmt, ap); 3452 va_end(ap); 3453 printf("%p: ", (void *)vp); 3454 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3455 printf(" usecount %d, writecount %d, refcount %d", 3456 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 3457 switch (vp->v_type) { 3458 case VDIR: 3459 printf(" mountedhere %p\n", vp->v_mountedhere); 3460 break; 3461 case VCHR: 3462 printf(" rdev %p\n", vp->v_rdev); 3463 break; 3464 case VSOCK: 3465 printf(" socket %p\n", vp->v_unpcb); 3466 break; 3467 case VFIFO: 3468 printf(" fifoinfo %p\n", vp->v_fifoinfo); 3469 break; 3470 default: 3471 printf("\n"); 3472 break; 3473 } 3474 buf[0] = '\0'; 3475 buf[1] = '\0'; 3476 if (vp->v_vflag & VV_ROOT) 3477 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3478 if (vp->v_vflag & VV_ISTTY) 3479 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3480 if (vp->v_vflag & VV_NOSYNC) 3481 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3482 if (vp->v_vflag & VV_ETERNALDEV) 3483 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3484 if (vp->v_vflag & VV_CACHEDLABEL) 3485 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3486 if (vp->v_vflag & VV_TEXT) 3487 strlcat(buf, "|VV_TEXT", sizeof(buf)); 3488 if (vp->v_vflag & VV_COPYONWRITE) 3489 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3490 if (vp->v_vflag & VV_SYSTEM) 3491 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3492 if (vp->v_vflag & VV_PROCDEP) 3493 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3494 if (vp->v_vflag & VV_NOKNOTE) 3495 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3496 if (vp->v_vflag & VV_DELETED) 3497 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3498 if (vp->v_vflag & VV_MD) 3499 strlcat(buf, "|VV_MD", sizeof(buf)); 3500 if (vp->v_vflag & VV_FORCEINSMQ) 3501 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3502 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3503 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3504 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3505 if (flags != 0) { 3506 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3507 strlcat(buf, buf2, sizeof(buf)); 3508 } 3509 if (vp->v_iflag & VI_MOUNT) 3510 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3511 if (vp->v_iflag & VI_DOOMED) 3512 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 3513 if (vp->v_iflag & VI_FREE) 3514 strlcat(buf, "|VI_FREE", sizeof(buf)); 3515 if (vp->v_iflag & VI_ACTIVE) 3516 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3517 if (vp->v_iflag & VI_DOINGINACT) 3518 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3519 if (vp->v_iflag & VI_OWEINACT) 3520 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3521 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | 3522 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT); 3523 if (flags != 0) { 3524 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3525 strlcat(buf, buf2, sizeof(buf)); 3526 } 3527 printf(" flags (%s)\n", buf + 1); 3528 if (mtx_owned(VI_MTX(vp))) 3529 printf(" VI_LOCKed"); 3530 if (vp->v_object != NULL) 3531 printf(" v_object %p ref %d pages %d " 3532 "cleanbuf %d dirtybuf %d\n", 3533 vp->v_object, vp->v_object->ref_count, 3534 vp->v_object->resident_page_count, 3535 vp->v_bufobj.bo_clean.bv_cnt, 3536 vp->v_bufobj.bo_dirty.bv_cnt); 3537 printf(" "); 3538 lockmgr_printinfo(vp->v_vnlock); 3539 if (vp->v_data != NULL) 3540 VOP_PRINT(vp); 3541 } 3542 3543 #ifdef DDB 3544 /* 3545 * List all of the locked vnodes in the system. 3546 * Called when debugging the kernel. 3547 */ 3548 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3549 { 3550 struct mount *mp; 3551 struct vnode *vp; 3552 3553 /* 3554 * Note: because this is DDB, we can't obey the locking semantics 3555 * for these structures, which means we could catch an inconsistent 3556 * state and dereference a nasty pointer. Not much to be done 3557 * about that. 3558 */ 3559 db_printf("Locked vnodes\n"); 3560 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3561 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3562 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3563 vn_printf(vp, "vnode "); 3564 } 3565 } 3566 } 3567 3568 /* 3569 * Show details about the given vnode. 3570 */ 3571 DB_SHOW_COMMAND(vnode, db_show_vnode) 3572 { 3573 struct vnode *vp; 3574 3575 if (!have_addr) 3576 return; 3577 vp = (struct vnode *)addr; 3578 vn_printf(vp, "vnode "); 3579 } 3580 3581 /* 3582 * Show details about the given mount point. 3583 */ 3584 DB_SHOW_COMMAND(mount, db_show_mount) 3585 { 3586 struct mount *mp; 3587 struct vfsopt *opt; 3588 struct statfs *sp; 3589 struct vnode *vp; 3590 char buf[512]; 3591 uint64_t mflags; 3592 u_int flags; 3593 3594 if (!have_addr) { 3595 /* No address given, print short info about all mount points. */ 3596 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3597 db_printf("%p %s on %s (%s)\n", mp, 3598 mp->mnt_stat.f_mntfromname, 3599 mp->mnt_stat.f_mntonname, 3600 mp->mnt_stat.f_fstypename); 3601 if (db_pager_quit) 3602 break; 3603 } 3604 db_printf("\nMore info: show mount <addr>\n"); 3605 return; 3606 } 3607 3608 mp = (struct mount *)addr; 3609 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3610 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3611 3612 buf[0] = '\0'; 3613 mflags = mp->mnt_flag; 3614 #define MNT_FLAG(flag) do { \ 3615 if (mflags & (flag)) { \ 3616 if (buf[0] != '\0') \ 3617 strlcat(buf, ", ", sizeof(buf)); \ 3618 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3619 mflags &= ~(flag); \ 3620 } \ 3621 } while (0) 3622 MNT_FLAG(MNT_RDONLY); 3623 MNT_FLAG(MNT_SYNCHRONOUS); 3624 MNT_FLAG(MNT_NOEXEC); 3625 MNT_FLAG(MNT_NOSUID); 3626 MNT_FLAG(MNT_NFS4ACLS); 3627 MNT_FLAG(MNT_UNION); 3628 MNT_FLAG(MNT_ASYNC); 3629 MNT_FLAG(MNT_SUIDDIR); 3630 MNT_FLAG(MNT_SOFTDEP); 3631 MNT_FLAG(MNT_NOSYMFOLLOW); 3632 MNT_FLAG(MNT_GJOURNAL); 3633 MNT_FLAG(MNT_MULTILABEL); 3634 MNT_FLAG(MNT_ACLS); 3635 MNT_FLAG(MNT_NOATIME); 3636 MNT_FLAG(MNT_NOCLUSTERR); 3637 MNT_FLAG(MNT_NOCLUSTERW); 3638 MNT_FLAG(MNT_SUJ); 3639 MNT_FLAG(MNT_EXRDONLY); 3640 MNT_FLAG(MNT_EXPORTED); 3641 MNT_FLAG(MNT_DEFEXPORTED); 3642 MNT_FLAG(MNT_EXPORTANON); 3643 MNT_FLAG(MNT_EXKERB); 3644 MNT_FLAG(MNT_EXPUBLIC); 3645 MNT_FLAG(MNT_LOCAL); 3646 MNT_FLAG(MNT_QUOTA); 3647 MNT_FLAG(MNT_ROOTFS); 3648 MNT_FLAG(MNT_USER); 3649 MNT_FLAG(MNT_IGNORE); 3650 MNT_FLAG(MNT_UPDATE); 3651 MNT_FLAG(MNT_DELEXPORT); 3652 MNT_FLAG(MNT_RELOAD); 3653 MNT_FLAG(MNT_FORCE); 3654 MNT_FLAG(MNT_SNAPSHOT); 3655 MNT_FLAG(MNT_BYFSID); 3656 #undef MNT_FLAG 3657 if (mflags != 0) { 3658 if (buf[0] != '\0') 3659 strlcat(buf, ", ", sizeof(buf)); 3660 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3661 "0x%016jx", mflags); 3662 } 3663 db_printf(" mnt_flag = %s\n", buf); 3664 3665 buf[0] = '\0'; 3666 flags = mp->mnt_kern_flag; 3667 #define MNT_KERN_FLAG(flag) do { \ 3668 if (flags & (flag)) { \ 3669 if (buf[0] != '\0') \ 3670 strlcat(buf, ", ", sizeof(buf)); \ 3671 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3672 flags &= ~(flag); \ 3673 } \ 3674 } while (0) 3675 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3676 MNT_KERN_FLAG(MNTK_ASYNC); 3677 MNT_KERN_FLAG(MNTK_SOFTDEP); 3678 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 3679 MNT_KERN_FLAG(MNTK_DRAINING); 3680 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3681 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3682 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3683 MNT_KERN_FLAG(MNTK_NO_IOPF); 3684 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3685 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3686 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3687 MNT_KERN_FLAG(MNTK_MARKER); 3688 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3689 MNT_KERN_FLAG(MNTK_NOASYNC); 3690 MNT_KERN_FLAG(MNTK_UNMOUNT); 3691 MNT_KERN_FLAG(MNTK_MWAIT); 3692 MNT_KERN_FLAG(MNTK_SUSPEND); 3693 MNT_KERN_FLAG(MNTK_SUSPEND2); 3694 MNT_KERN_FLAG(MNTK_SUSPENDED); 3695 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3696 MNT_KERN_FLAG(MNTK_NOKNOTE); 3697 #undef MNT_KERN_FLAG 3698 if (flags != 0) { 3699 if (buf[0] != '\0') 3700 strlcat(buf, ", ", sizeof(buf)); 3701 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3702 "0x%08x", flags); 3703 } 3704 db_printf(" mnt_kern_flag = %s\n", buf); 3705 3706 db_printf(" mnt_opt = "); 3707 opt = TAILQ_FIRST(mp->mnt_opt); 3708 if (opt != NULL) { 3709 db_printf("%s", opt->name); 3710 opt = TAILQ_NEXT(opt, link); 3711 while (opt != NULL) { 3712 db_printf(", %s", opt->name); 3713 opt = TAILQ_NEXT(opt, link); 3714 } 3715 } 3716 db_printf("\n"); 3717 3718 sp = &mp->mnt_stat; 3719 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3720 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3721 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3722 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3723 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3724 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 3725 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 3726 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 3727 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 3728 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 3729 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 3730 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 3731 3732 db_printf(" mnt_cred = { uid=%u ruid=%u", 3733 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 3734 if (jailed(mp->mnt_cred)) 3735 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 3736 db_printf(" }\n"); 3737 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 3738 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 3739 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 3740 db_printf(" mnt_activevnodelistsize = %d\n", 3741 mp->mnt_activevnodelistsize); 3742 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 3743 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 3744 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 3745 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 3746 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); 3747 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 3748 db_printf(" mnt_secondary_accwrites = %d\n", 3749 mp->mnt_secondary_accwrites); 3750 db_printf(" mnt_gjprovider = %s\n", 3751 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 3752 3753 db_printf("\n\nList of active vnodes\n"); 3754 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 3755 if (vp->v_type != VMARKER) { 3756 vn_printf(vp, "vnode "); 3757 if (db_pager_quit) 3758 break; 3759 } 3760 } 3761 db_printf("\n\nList of inactive vnodes\n"); 3762 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3763 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 3764 vn_printf(vp, "vnode "); 3765 if (db_pager_quit) 3766 break; 3767 } 3768 } 3769 } 3770 #endif /* DDB */ 3771 3772 /* 3773 * Fill in a struct xvfsconf based on a struct vfsconf. 3774 */ 3775 static int 3776 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 3777 { 3778 struct xvfsconf xvfsp; 3779 3780 bzero(&xvfsp, sizeof(xvfsp)); 3781 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3782 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3783 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3784 xvfsp.vfc_flags = vfsp->vfc_flags; 3785 /* 3786 * These are unused in userland, we keep them 3787 * to not break binary compatibility. 3788 */ 3789 xvfsp.vfc_vfsops = NULL; 3790 xvfsp.vfc_next = NULL; 3791 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3792 } 3793 3794 #ifdef COMPAT_FREEBSD32 3795 struct xvfsconf32 { 3796 uint32_t vfc_vfsops; 3797 char vfc_name[MFSNAMELEN]; 3798 int32_t vfc_typenum; 3799 int32_t vfc_refcount; 3800 int32_t vfc_flags; 3801 uint32_t vfc_next; 3802 }; 3803 3804 static int 3805 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 3806 { 3807 struct xvfsconf32 xvfsp; 3808 3809 bzero(&xvfsp, sizeof(xvfsp)); 3810 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3811 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3812 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3813 xvfsp.vfc_flags = vfsp->vfc_flags; 3814 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3815 } 3816 #endif 3817 3818 /* 3819 * Top level filesystem related information gathering. 3820 */ 3821 static int 3822 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3823 { 3824 struct vfsconf *vfsp; 3825 int error; 3826 3827 error = 0; 3828 vfsconf_slock(); 3829 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3830 #ifdef COMPAT_FREEBSD32 3831 if (req->flags & SCTL_MASK32) 3832 error = vfsconf2x32(req, vfsp); 3833 else 3834 #endif 3835 error = vfsconf2x(req, vfsp); 3836 if (error) 3837 break; 3838 } 3839 vfsconf_sunlock(); 3840 return (error); 3841 } 3842 3843 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 3844 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 3845 "S,xvfsconf", "List of all configured filesystems"); 3846 3847 #ifndef BURN_BRIDGES 3848 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3849 3850 static int 3851 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3852 { 3853 int *name = (int *)arg1 - 1; /* XXX */ 3854 u_int namelen = arg2 + 1; /* XXX */ 3855 struct vfsconf *vfsp; 3856 3857 log(LOG_WARNING, "userland calling deprecated sysctl, " 3858 "please rebuild world\n"); 3859 3860 #if 1 || defined(COMPAT_PRELITE2) 3861 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3862 if (namelen == 1) 3863 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3864 #endif 3865 3866 switch (name[1]) { 3867 case VFS_MAXTYPENUM: 3868 if (namelen != 2) 3869 return (ENOTDIR); 3870 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3871 case VFS_CONF: 3872 if (namelen != 3) 3873 return (ENOTDIR); /* overloaded */ 3874 vfsconf_slock(); 3875 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3876 if (vfsp->vfc_typenum == name[2]) 3877 break; 3878 } 3879 vfsconf_sunlock(); 3880 if (vfsp == NULL) 3881 return (EOPNOTSUPP); 3882 #ifdef COMPAT_FREEBSD32 3883 if (req->flags & SCTL_MASK32) 3884 return (vfsconf2x32(req, vfsp)); 3885 else 3886 #endif 3887 return (vfsconf2x(req, vfsp)); 3888 } 3889 return (EOPNOTSUPP); 3890 } 3891 3892 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 3893 CTLFLAG_MPSAFE, vfs_sysctl, 3894 "Generic filesystem"); 3895 3896 #if 1 || defined(COMPAT_PRELITE2) 3897 3898 static int 3899 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3900 { 3901 int error; 3902 struct vfsconf *vfsp; 3903 struct ovfsconf ovfs; 3904 3905 vfsconf_slock(); 3906 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3907 bzero(&ovfs, sizeof(ovfs)); 3908 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3909 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3910 ovfs.vfc_index = vfsp->vfc_typenum; 3911 ovfs.vfc_refcount = vfsp->vfc_refcount; 3912 ovfs.vfc_flags = vfsp->vfc_flags; 3913 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3914 if (error != 0) { 3915 vfsconf_sunlock(); 3916 return (error); 3917 } 3918 } 3919 vfsconf_sunlock(); 3920 return (0); 3921 } 3922 3923 #endif /* 1 || COMPAT_PRELITE2 */ 3924 #endif /* !BURN_BRIDGES */ 3925 3926 #define KINFO_VNODESLOP 10 3927 #ifdef notyet 3928 /* 3929 * Dump vnode list (via sysctl). 3930 */ 3931 /* ARGSUSED */ 3932 static int 3933 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3934 { 3935 struct xvnode *xvn; 3936 struct mount *mp; 3937 struct vnode *vp; 3938 int error, len, n; 3939 3940 /* 3941 * Stale numvnodes access is not fatal here. 3942 */ 3943 req->lock = 0; 3944 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3945 if (!req->oldptr) 3946 /* Make an estimate */ 3947 return (SYSCTL_OUT(req, 0, len)); 3948 3949 error = sysctl_wire_old_buffer(req, 0); 3950 if (error != 0) 3951 return (error); 3952 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3953 n = 0; 3954 mtx_lock(&mountlist_mtx); 3955 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3956 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 3957 continue; 3958 MNT_ILOCK(mp); 3959 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3960 if (n == len) 3961 break; 3962 vref(vp); 3963 xvn[n].xv_size = sizeof *xvn; 3964 xvn[n].xv_vnode = vp; 3965 xvn[n].xv_id = 0; /* XXX compat */ 3966 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3967 XV_COPY(usecount); 3968 XV_COPY(writecount); 3969 XV_COPY(holdcnt); 3970 XV_COPY(mount); 3971 XV_COPY(numoutput); 3972 XV_COPY(type); 3973 #undef XV_COPY 3974 xvn[n].xv_flag = vp->v_vflag; 3975 3976 switch (vp->v_type) { 3977 case VREG: 3978 case VDIR: 3979 case VLNK: 3980 break; 3981 case VBLK: 3982 case VCHR: 3983 if (vp->v_rdev == NULL) { 3984 vrele(vp); 3985 continue; 3986 } 3987 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3988 break; 3989 case VSOCK: 3990 xvn[n].xv_socket = vp->v_socket; 3991 break; 3992 case VFIFO: 3993 xvn[n].xv_fifo = vp->v_fifoinfo; 3994 break; 3995 case VNON: 3996 case VBAD: 3997 default: 3998 /* shouldn't happen? */ 3999 vrele(vp); 4000 continue; 4001 } 4002 vrele(vp); 4003 ++n; 4004 } 4005 MNT_IUNLOCK(mp); 4006 mtx_lock(&mountlist_mtx); 4007 vfs_unbusy(mp); 4008 if (n == len) 4009 break; 4010 } 4011 mtx_unlock(&mountlist_mtx); 4012 4013 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4014 free(xvn, M_TEMP); 4015 return (error); 4016 } 4017 4018 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4019 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4020 ""); 4021 #endif 4022 4023 static void 4024 unmount_or_warn(struct mount *mp) 4025 { 4026 int error; 4027 4028 error = dounmount(mp, MNT_FORCE, curthread); 4029 if (error != 0) { 4030 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4031 if (error == EBUSY) 4032 printf("BUSY)\n"); 4033 else 4034 printf("%d)\n", error); 4035 } 4036 } 4037 4038 /* 4039 * Unmount all filesystems. The list is traversed in reverse order 4040 * of mounting to avoid dependencies. 4041 */ 4042 void 4043 vfs_unmountall(void) 4044 { 4045 struct mount *mp, *tmp; 4046 4047 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4048 4049 /* 4050 * Since this only runs when rebooting, it is not interlocked. 4051 */ 4052 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4053 vfs_ref(mp); 4054 4055 /* 4056 * Forcibly unmounting "/dev" before "/" would prevent clean 4057 * unmount of the latter. 4058 */ 4059 if (mp == rootdevmp) 4060 continue; 4061 4062 unmount_or_warn(mp); 4063 } 4064 4065 if (rootdevmp != NULL) 4066 unmount_or_warn(rootdevmp); 4067 } 4068 4069 /* 4070 * perform msync on all vnodes under a mount point 4071 * the mount point must be locked. 4072 */ 4073 void 4074 vfs_msync(struct mount *mp, int flags) 4075 { 4076 struct vnode *vp, *mvp; 4077 struct vm_object *obj; 4078 4079 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4080 4081 vnlru_return_batch(mp); 4082 4083 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 4084 obj = vp->v_object; 4085 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 4086 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 4087 if (!vget(vp, 4088 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 4089 curthread)) { 4090 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 4091 vput(vp); 4092 continue; 4093 } 4094 4095 obj = vp->v_object; 4096 if (obj != NULL) { 4097 VM_OBJECT_WLOCK(obj); 4098 vm_object_page_clean(obj, 0, 0, 4099 flags == MNT_WAIT ? 4100 OBJPC_SYNC : OBJPC_NOSYNC); 4101 VM_OBJECT_WUNLOCK(obj); 4102 } 4103 vput(vp); 4104 } 4105 } else 4106 VI_UNLOCK(vp); 4107 } 4108 } 4109 4110 static void 4111 destroy_vpollinfo_free(struct vpollinfo *vi) 4112 { 4113 4114 knlist_destroy(&vi->vpi_selinfo.si_note); 4115 mtx_destroy(&vi->vpi_lock); 4116 uma_zfree(vnodepoll_zone, vi); 4117 } 4118 4119 static void 4120 destroy_vpollinfo(struct vpollinfo *vi) 4121 { 4122 4123 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4124 seldrain(&vi->vpi_selinfo); 4125 destroy_vpollinfo_free(vi); 4126 } 4127 4128 /* 4129 * Initialize per-vnode helper structure to hold poll-related state. 4130 */ 4131 void 4132 v_addpollinfo(struct vnode *vp) 4133 { 4134 struct vpollinfo *vi; 4135 4136 if (vp->v_pollinfo != NULL) 4137 return; 4138 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4139 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4140 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4141 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4142 VI_LOCK(vp); 4143 if (vp->v_pollinfo != NULL) { 4144 VI_UNLOCK(vp); 4145 destroy_vpollinfo_free(vi); 4146 return; 4147 } 4148 vp->v_pollinfo = vi; 4149 VI_UNLOCK(vp); 4150 } 4151 4152 /* 4153 * Record a process's interest in events which might happen to 4154 * a vnode. Because poll uses the historic select-style interface 4155 * internally, this routine serves as both the ``check for any 4156 * pending events'' and the ``record my interest in future events'' 4157 * functions. (These are done together, while the lock is held, 4158 * to avoid race conditions.) 4159 */ 4160 int 4161 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4162 { 4163 4164 v_addpollinfo(vp); 4165 mtx_lock(&vp->v_pollinfo->vpi_lock); 4166 if (vp->v_pollinfo->vpi_revents & events) { 4167 /* 4168 * This leaves events we are not interested 4169 * in available for the other process which 4170 * which presumably had requested them 4171 * (otherwise they would never have been 4172 * recorded). 4173 */ 4174 events &= vp->v_pollinfo->vpi_revents; 4175 vp->v_pollinfo->vpi_revents &= ~events; 4176 4177 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4178 return (events); 4179 } 4180 vp->v_pollinfo->vpi_events |= events; 4181 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4182 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4183 return (0); 4184 } 4185 4186 /* 4187 * Routine to create and manage a filesystem syncer vnode. 4188 */ 4189 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4190 static int sync_fsync(struct vop_fsync_args *); 4191 static int sync_inactive(struct vop_inactive_args *); 4192 static int sync_reclaim(struct vop_reclaim_args *); 4193 4194 static struct vop_vector sync_vnodeops = { 4195 .vop_bypass = VOP_EOPNOTSUPP, 4196 .vop_close = sync_close, /* close */ 4197 .vop_fsync = sync_fsync, /* fsync */ 4198 .vop_inactive = sync_inactive, /* inactive */ 4199 .vop_reclaim = sync_reclaim, /* reclaim */ 4200 .vop_lock1 = vop_stdlock, /* lock */ 4201 .vop_unlock = vop_stdunlock, /* unlock */ 4202 .vop_islocked = vop_stdislocked, /* islocked */ 4203 }; 4204 4205 /* 4206 * Create a new filesystem syncer vnode for the specified mount point. 4207 */ 4208 void 4209 vfs_allocate_syncvnode(struct mount *mp) 4210 { 4211 struct vnode *vp; 4212 struct bufobj *bo; 4213 static long start, incr, next; 4214 int error; 4215 4216 /* Allocate a new vnode */ 4217 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4218 if (error != 0) 4219 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4220 vp->v_type = VNON; 4221 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4222 vp->v_vflag |= VV_FORCEINSMQ; 4223 error = insmntque(vp, mp); 4224 if (error != 0) 4225 panic("vfs_allocate_syncvnode: insmntque() failed"); 4226 vp->v_vflag &= ~VV_FORCEINSMQ; 4227 VOP_UNLOCK(vp, 0); 4228 /* 4229 * Place the vnode onto the syncer worklist. We attempt to 4230 * scatter them about on the list so that they will go off 4231 * at evenly distributed times even if all the filesystems 4232 * are mounted at once. 4233 */ 4234 next += incr; 4235 if (next == 0 || next > syncer_maxdelay) { 4236 start /= 2; 4237 incr /= 2; 4238 if (start == 0) { 4239 start = syncer_maxdelay / 2; 4240 incr = syncer_maxdelay; 4241 } 4242 next = start; 4243 } 4244 bo = &vp->v_bufobj; 4245 BO_LOCK(bo); 4246 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4247 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4248 mtx_lock(&sync_mtx); 4249 sync_vnode_count++; 4250 if (mp->mnt_syncer == NULL) { 4251 mp->mnt_syncer = vp; 4252 vp = NULL; 4253 } 4254 mtx_unlock(&sync_mtx); 4255 BO_UNLOCK(bo); 4256 if (vp != NULL) { 4257 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4258 vgone(vp); 4259 vput(vp); 4260 } 4261 } 4262 4263 void 4264 vfs_deallocate_syncvnode(struct mount *mp) 4265 { 4266 struct vnode *vp; 4267 4268 mtx_lock(&sync_mtx); 4269 vp = mp->mnt_syncer; 4270 if (vp != NULL) 4271 mp->mnt_syncer = NULL; 4272 mtx_unlock(&sync_mtx); 4273 if (vp != NULL) 4274 vrele(vp); 4275 } 4276 4277 /* 4278 * Do a lazy sync of the filesystem. 4279 */ 4280 static int 4281 sync_fsync(struct vop_fsync_args *ap) 4282 { 4283 struct vnode *syncvp = ap->a_vp; 4284 struct mount *mp = syncvp->v_mount; 4285 int error, save; 4286 struct bufobj *bo; 4287 4288 /* 4289 * We only need to do something if this is a lazy evaluation. 4290 */ 4291 if (ap->a_waitfor != MNT_LAZY) 4292 return (0); 4293 4294 /* 4295 * Move ourselves to the back of the sync list. 4296 */ 4297 bo = &syncvp->v_bufobj; 4298 BO_LOCK(bo); 4299 vn_syncer_add_to_worklist(bo, syncdelay); 4300 BO_UNLOCK(bo); 4301 4302 /* 4303 * Walk the list of vnodes pushing all that are dirty and 4304 * not already on the sync list. 4305 */ 4306 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4307 return (0); 4308 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4309 vfs_unbusy(mp); 4310 return (0); 4311 } 4312 save = curthread_pflags_set(TDP_SYNCIO); 4313 vfs_msync(mp, MNT_NOWAIT); 4314 error = VFS_SYNC(mp, MNT_LAZY); 4315 curthread_pflags_restore(save); 4316 vn_finished_write(mp); 4317 vfs_unbusy(mp); 4318 return (error); 4319 } 4320 4321 /* 4322 * The syncer vnode is no referenced. 4323 */ 4324 static int 4325 sync_inactive(struct vop_inactive_args *ap) 4326 { 4327 4328 vgone(ap->a_vp); 4329 return (0); 4330 } 4331 4332 /* 4333 * The syncer vnode is no longer needed and is being decommissioned. 4334 * 4335 * Modifications to the worklist must be protected by sync_mtx. 4336 */ 4337 static int 4338 sync_reclaim(struct vop_reclaim_args *ap) 4339 { 4340 struct vnode *vp = ap->a_vp; 4341 struct bufobj *bo; 4342 4343 bo = &vp->v_bufobj; 4344 BO_LOCK(bo); 4345 mtx_lock(&sync_mtx); 4346 if (vp->v_mount->mnt_syncer == vp) 4347 vp->v_mount->mnt_syncer = NULL; 4348 if (bo->bo_flag & BO_ONWORKLST) { 4349 LIST_REMOVE(bo, bo_synclist); 4350 syncer_worklist_len--; 4351 sync_vnode_count--; 4352 bo->bo_flag &= ~BO_ONWORKLST; 4353 } 4354 mtx_unlock(&sync_mtx); 4355 BO_UNLOCK(bo); 4356 4357 return (0); 4358 } 4359 4360 /* 4361 * Check if vnode represents a disk device 4362 */ 4363 int 4364 vn_isdisk(struct vnode *vp, int *errp) 4365 { 4366 int error; 4367 4368 if (vp->v_type != VCHR) { 4369 error = ENOTBLK; 4370 goto out; 4371 } 4372 error = 0; 4373 dev_lock(); 4374 if (vp->v_rdev == NULL) 4375 error = ENXIO; 4376 else if (vp->v_rdev->si_devsw == NULL) 4377 error = ENXIO; 4378 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4379 error = ENOTBLK; 4380 dev_unlock(); 4381 out: 4382 if (errp != NULL) 4383 *errp = error; 4384 return (error == 0); 4385 } 4386 4387 /* 4388 * Common filesystem object access control check routine. Accepts a 4389 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4390 * and optional call-by-reference privused argument allowing vaccess() 4391 * to indicate to the caller whether privilege was used to satisfy the 4392 * request (obsoleted). Returns 0 on success, or an errno on failure. 4393 */ 4394 int 4395 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4396 accmode_t accmode, struct ucred *cred, int *privused) 4397 { 4398 accmode_t dac_granted; 4399 accmode_t priv_granted; 4400 4401 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4402 ("invalid bit in accmode")); 4403 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4404 ("VAPPEND without VWRITE")); 4405 4406 /* 4407 * Look for a normal, non-privileged way to access the file/directory 4408 * as requested. If it exists, go with that. 4409 */ 4410 4411 if (privused != NULL) 4412 *privused = 0; 4413 4414 dac_granted = 0; 4415 4416 /* Check the owner. */ 4417 if (cred->cr_uid == file_uid) { 4418 dac_granted |= VADMIN; 4419 if (file_mode & S_IXUSR) 4420 dac_granted |= VEXEC; 4421 if (file_mode & S_IRUSR) 4422 dac_granted |= VREAD; 4423 if (file_mode & S_IWUSR) 4424 dac_granted |= (VWRITE | VAPPEND); 4425 4426 if ((accmode & dac_granted) == accmode) 4427 return (0); 4428 4429 goto privcheck; 4430 } 4431 4432 /* Otherwise, check the groups (first match) */ 4433 if (groupmember(file_gid, cred)) { 4434 if (file_mode & S_IXGRP) 4435 dac_granted |= VEXEC; 4436 if (file_mode & S_IRGRP) 4437 dac_granted |= VREAD; 4438 if (file_mode & S_IWGRP) 4439 dac_granted |= (VWRITE | VAPPEND); 4440 4441 if ((accmode & dac_granted) == accmode) 4442 return (0); 4443 4444 goto privcheck; 4445 } 4446 4447 /* Otherwise, check everyone else. */ 4448 if (file_mode & S_IXOTH) 4449 dac_granted |= VEXEC; 4450 if (file_mode & S_IROTH) 4451 dac_granted |= VREAD; 4452 if (file_mode & S_IWOTH) 4453 dac_granted |= (VWRITE | VAPPEND); 4454 if ((accmode & dac_granted) == accmode) 4455 return (0); 4456 4457 privcheck: 4458 /* 4459 * Build a privilege mask to determine if the set of privileges 4460 * satisfies the requirements when combined with the granted mask 4461 * from above. For each privilege, if the privilege is required, 4462 * bitwise or the request type onto the priv_granted mask. 4463 */ 4464 priv_granted = 0; 4465 4466 if (type == VDIR) { 4467 /* 4468 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4469 * requests, instead of PRIV_VFS_EXEC. 4470 */ 4471 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4472 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 4473 priv_granted |= VEXEC; 4474 } else { 4475 /* 4476 * Ensure that at least one execute bit is on. Otherwise, 4477 * a privileged user will always succeed, and we don't want 4478 * this to happen unless the file really is executable. 4479 */ 4480 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4481 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4482 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 4483 priv_granted |= VEXEC; 4484 } 4485 4486 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4487 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 4488 priv_granted |= VREAD; 4489 4490 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4491 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 4492 priv_granted |= (VWRITE | VAPPEND); 4493 4494 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4495 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 4496 priv_granted |= VADMIN; 4497 4498 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4499 /* XXX audit: privilege used */ 4500 if (privused != NULL) 4501 *privused = 1; 4502 return (0); 4503 } 4504 4505 return ((accmode & VADMIN) ? EPERM : EACCES); 4506 } 4507 4508 /* 4509 * Credential check based on process requesting service, and per-attribute 4510 * permissions. 4511 */ 4512 int 4513 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4514 struct thread *td, accmode_t accmode) 4515 { 4516 4517 /* 4518 * Kernel-invoked always succeeds. 4519 */ 4520 if (cred == NOCRED) 4521 return (0); 4522 4523 /* 4524 * Do not allow privileged processes in jail to directly manipulate 4525 * system attributes. 4526 */ 4527 switch (attrnamespace) { 4528 case EXTATTR_NAMESPACE_SYSTEM: 4529 /* Potentially should be: return (EPERM); */ 4530 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 4531 case EXTATTR_NAMESPACE_USER: 4532 return (VOP_ACCESS(vp, accmode, cred, td)); 4533 default: 4534 return (EPERM); 4535 } 4536 } 4537 4538 #ifdef DEBUG_VFS_LOCKS 4539 /* 4540 * This only exists to suppress warnings from unlocked specfs accesses. It is 4541 * no longer ok to have an unlocked VFS. 4542 */ 4543 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4544 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4545 4546 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4547 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4548 "Drop into debugger on lock violation"); 4549 4550 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4551 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4552 0, "Check for interlock across VOPs"); 4553 4554 int vfs_badlock_print = 1; /* Print lock violations. */ 4555 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4556 0, "Print lock violations"); 4557 4558 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 4559 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 4560 0, "Print vnode details on lock violations"); 4561 4562 #ifdef KDB 4563 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4564 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4565 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4566 #endif 4567 4568 static void 4569 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4570 { 4571 4572 #ifdef KDB 4573 if (vfs_badlock_backtrace) 4574 kdb_backtrace(); 4575 #endif 4576 if (vfs_badlock_vnode) 4577 vn_printf(vp, "vnode "); 4578 if (vfs_badlock_print) 4579 printf("%s: %p %s\n", str, (void *)vp, msg); 4580 if (vfs_badlock_ddb) 4581 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4582 } 4583 4584 void 4585 assert_vi_locked(struct vnode *vp, const char *str) 4586 { 4587 4588 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4589 vfs_badlock("interlock is not locked but should be", str, vp); 4590 } 4591 4592 void 4593 assert_vi_unlocked(struct vnode *vp, const char *str) 4594 { 4595 4596 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4597 vfs_badlock("interlock is locked but should not be", str, vp); 4598 } 4599 4600 void 4601 assert_vop_locked(struct vnode *vp, const char *str) 4602 { 4603 int locked; 4604 4605 if (!IGNORE_LOCK(vp)) { 4606 locked = VOP_ISLOCKED(vp); 4607 if (locked == 0 || locked == LK_EXCLOTHER) 4608 vfs_badlock("is not locked but should be", str, vp); 4609 } 4610 } 4611 4612 void 4613 assert_vop_unlocked(struct vnode *vp, const char *str) 4614 { 4615 4616 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4617 vfs_badlock("is locked but should not be", str, vp); 4618 } 4619 4620 void 4621 assert_vop_elocked(struct vnode *vp, const char *str) 4622 { 4623 4624 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4625 vfs_badlock("is not exclusive locked but should be", str, vp); 4626 } 4627 #endif /* DEBUG_VFS_LOCKS */ 4628 4629 void 4630 vop_rename_fail(struct vop_rename_args *ap) 4631 { 4632 4633 if (ap->a_tvp != NULL) 4634 vput(ap->a_tvp); 4635 if (ap->a_tdvp == ap->a_tvp) 4636 vrele(ap->a_tdvp); 4637 else 4638 vput(ap->a_tdvp); 4639 vrele(ap->a_fdvp); 4640 vrele(ap->a_fvp); 4641 } 4642 4643 void 4644 vop_rename_pre(void *ap) 4645 { 4646 struct vop_rename_args *a = ap; 4647 4648 #ifdef DEBUG_VFS_LOCKS 4649 if (a->a_tvp) 4650 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4651 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4652 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4653 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4654 4655 /* Check the source (from). */ 4656 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4657 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4658 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4659 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4660 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4661 4662 /* Check the target. */ 4663 if (a->a_tvp) 4664 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4665 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4666 #endif 4667 if (a->a_tdvp != a->a_fdvp) 4668 vhold(a->a_fdvp); 4669 if (a->a_tvp != a->a_fvp) 4670 vhold(a->a_fvp); 4671 vhold(a->a_tdvp); 4672 if (a->a_tvp) 4673 vhold(a->a_tvp); 4674 } 4675 4676 #ifdef DEBUG_VFS_LOCKS 4677 void 4678 vop_strategy_pre(void *ap) 4679 { 4680 struct vop_strategy_args *a; 4681 struct buf *bp; 4682 4683 a = ap; 4684 bp = a->a_bp; 4685 4686 /* 4687 * Cluster ops lock their component buffers but not the IO container. 4688 */ 4689 if ((bp->b_flags & B_CLUSTER) != 0) 4690 return; 4691 4692 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4693 if (vfs_badlock_print) 4694 printf( 4695 "VOP_STRATEGY: bp is not locked but should be\n"); 4696 if (vfs_badlock_ddb) 4697 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4698 } 4699 } 4700 4701 void 4702 vop_lock_pre(void *ap) 4703 { 4704 struct vop_lock1_args *a = ap; 4705 4706 if ((a->a_flags & LK_INTERLOCK) == 0) 4707 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4708 else 4709 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 4710 } 4711 4712 void 4713 vop_lock_post(void *ap, int rc) 4714 { 4715 struct vop_lock1_args *a = ap; 4716 4717 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4718 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 4719 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 4720 } 4721 4722 void 4723 vop_unlock_pre(void *ap) 4724 { 4725 struct vop_unlock_args *a = ap; 4726 4727 if (a->a_flags & LK_INTERLOCK) 4728 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4729 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4730 } 4731 4732 void 4733 vop_unlock_post(void *ap, int rc) 4734 { 4735 struct vop_unlock_args *a = ap; 4736 4737 if (a->a_flags & LK_INTERLOCK) 4738 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4739 } 4740 #endif 4741 4742 void 4743 vop_create_post(void *ap, int rc) 4744 { 4745 struct vop_create_args *a = ap; 4746 4747 if (!rc) 4748 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4749 } 4750 4751 void 4752 vop_deleteextattr_post(void *ap, int rc) 4753 { 4754 struct vop_deleteextattr_args *a = ap; 4755 4756 if (!rc) 4757 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4758 } 4759 4760 void 4761 vop_link_post(void *ap, int rc) 4762 { 4763 struct vop_link_args *a = ap; 4764 4765 if (!rc) { 4766 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4767 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4768 } 4769 } 4770 4771 void 4772 vop_mkdir_post(void *ap, int rc) 4773 { 4774 struct vop_mkdir_args *a = ap; 4775 4776 if (!rc) 4777 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4778 } 4779 4780 void 4781 vop_mknod_post(void *ap, int rc) 4782 { 4783 struct vop_mknod_args *a = ap; 4784 4785 if (!rc) 4786 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4787 } 4788 4789 void 4790 vop_reclaim_post(void *ap, int rc) 4791 { 4792 struct vop_reclaim_args *a = ap; 4793 4794 if (!rc) 4795 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 4796 } 4797 4798 void 4799 vop_remove_post(void *ap, int rc) 4800 { 4801 struct vop_remove_args *a = ap; 4802 4803 if (!rc) { 4804 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4805 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4806 } 4807 } 4808 4809 void 4810 vop_rename_post(void *ap, int rc) 4811 { 4812 struct vop_rename_args *a = ap; 4813 long hint; 4814 4815 if (!rc) { 4816 hint = NOTE_WRITE; 4817 if (a->a_fdvp == a->a_tdvp) { 4818 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 4819 hint |= NOTE_LINK; 4820 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4821 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4822 } else { 4823 hint |= NOTE_EXTEND; 4824 if (a->a_fvp->v_type == VDIR) 4825 hint |= NOTE_LINK; 4826 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4827 4828 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 4829 a->a_tvp->v_type == VDIR) 4830 hint &= ~NOTE_LINK; 4831 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4832 } 4833 4834 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4835 if (a->a_tvp) 4836 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4837 } 4838 if (a->a_tdvp != a->a_fdvp) 4839 vdrop(a->a_fdvp); 4840 if (a->a_tvp != a->a_fvp) 4841 vdrop(a->a_fvp); 4842 vdrop(a->a_tdvp); 4843 if (a->a_tvp) 4844 vdrop(a->a_tvp); 4845 } 4846 4847 void 4848 vop_rmdir_post(void *ap, int rc) 4849 { 4850 struct vop_rmdir_args *a = ap; 4851 4852 if (!rc) { 4853 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4854 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4855 } 4856 } 4857 4858 void 4859 vop_setattr_post(void *ap, int rc) 4860 { 4861 struct vop_setattr_args *a = ap; 4862 4863 if (!rc) 4864 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4865 } 4866 4867 void 4868 vop_setextattr_post(void *ap, int rc) 4869 { 4870 struct vop_setextattr_args *a = ap; 4871 4872 if (!rc) 4873 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4874 } 4875 4876 void 4877 vop_symlink_post(void *ap, int rc) 4878 { 4879 struct vop_symlink_args *a = ap; 4880 4881 if (!rc) 4882 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4883 } 4884 4885 void 4886 vop_open_post(void *ap, int rc) 4887 { 4888 struct vop_open_args *a = ap; 4889 4890 if (!rc) 4891 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 4892 } 4893 4894 void 4895 vop_close_post(void *ap, int rc) 4896 { 4897 struct vop_close_args *a = ap; 4898 4899 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 4900 (a->a_vp->v_iflag & VI_DOOMED) == 0)) { 4901 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 4902 NOTE_CLOSE_WRITE : NOTE_CLOSE); 4903 } 4904 } 4905 4906 void 4907 vop_read_post(void *ap, int rc) 4908 { 4909 struct vop_read_args *a = ap; 4910 4911 if (!rc) 4912 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4913 } 4914 4915 void 4916 vop_readdir_post(void *ap, int rc) 4917 { 4918 struct vop_readdir_args *a = ap; 4919 4920 if (!rc) 4921 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4922 } 4923 4924 static struct knlist fs_knlist; 4925 4926 static void 4927 vfs_event_init(void *arg) 4928 { 4929 knlist_init_mtx(&fs_knlist, NULL); 4930 } 4931 /* XXX - correct order? */ 4932 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 4933 4934 void 4935 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 4936 { 4937 4938 KNOTE_UNLOCKED(&fs_knlist, event); 4939 } 4940 4941 static int filt_fsattach(struct knote *kn); 4942 static void filt_fsdetach(struct knote *kn); 4943 static int filt_fsevent(struct knote *kn, long hint); 4944 4945 struct filterops fs_filtops = { 4946 .f_isfd = 0, 4947 .f_attach = filt_fsattach, 4948 .f_detach = filt_fsdetach, 4949 .f_event = filt_fsevent 4950 }; 4951 4952 static int 4953 filt_fsattach(struct knote *kn) 4954 { 4955 4956 kn->kn_flags |= EV_CLEAR; 4957 knlist_add(&fs_knlist, kn, 0); 4958 return (0); 4959 } 4960 4961 static void 4962 filt_fsdetach(struct knote *kn) 4963 { 4964 4965 knlist_remove(&fs_knlist, kn, 0); 4966 } 4967 4968 static int 4969 filt_fsevent(struct knote *kn, long hint) 4970 { 4971 4972 kn->kn_fflags |= hint; 4973 return (kn->kn_fflags != 0); 4974 } 4975 4976 static int 4977 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 4978 { 4979 struct vfsidctl vc; 4980 int error; 4981 struct mount *mp; 4982 4983 error = SYSCTL_IN(req, &vc, sizeof(vc)); 4984 if (error) 4985 return (error); 4986 if (vc.vc_vers != VFS_CTL_VERS1) 4987 return (EINVAL); 4988 mp = vfs_getvfs(&vc.vc_fsid); 4989 if (mp == NULL) 4990 return (ENOENT); 4991 /* ensure that a specific sysctl goes to the right filesystem. */ 4992 if (strcmp(vc.vc_fstypename, "*") != 0 && 4993 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 4994 vfs_rel(mp); 4995 return (EINVAL); 4996 } 4997 VCTLTOREQ(&vc, req); 4998 error = VFS_SYSCTL(mp, vc.vc_op, req); 4999 vfs_rel(mp); 5000 return (error); 5001 } 5002 5003 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 5004 NULL, 0, sysctl_vfs_ctl, "", 5005 "Sysctl by fsid"); 5006 5007 /* 5008 * Function to initialize a va_filerev field sensibly. 5009 * XXX: Wouldn't a random number make a lot more sense ?? 5010 */ 5011 u_quad_t 5012 init_va_filerev(void) 5013 { 5014 struct bintime bt; 5015 5016 getbinuptime(&bt); 5017 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5018 } 5019 5020 static int filt_vfsread(struct knote *kn, long hint); 5021 static int filt_vfswrite(struct knote *kn, long hint); 5022 static int filt_vfsvnode(struct knote *kn, long hint); 5023 static void filt_vfsdetach(struct knote *kn); 5024 static struct filterops vfsread_filtops = { 5025 .f_isfd = 1, 5026 .f_detach = filt_vfsdetach, 5027 .f_event = filt_vfsread 5028 }; 5029 static struct filterops vfswrite_filtops = { 5030 .f_isfd = 1, 5031 .f_detach = filt_vfsdetach, 5032 .f_event = filt_vfswrite 5033 }; 5034 static struct filterops vfsvnode_filtops = { 5035 .f_isfd = 1, 5036 .f_detach = filt_vfsdetach, 5037 .f_event = filt_vfsvnode 5038 }; 5039 5040 static void 5041 vfs_knllock(void *arg) 5042 { 5043 struct vnode *vp = arg; 5044 5045 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5046 } 5047 5048 static void 5049 vfs_knlunlock(void *arg) 5050 { 5051 struct vnode *vp = arg; 5052 5053 VOP_UNLOCK(vp, 0); 5054 } 5055 5056 static void 5057 vfs_knl_assert_locked(void *arg) 5058 { 5059 #ifdef DEBUG_VFS_LOCKS 5060 struct vnode *vp = arg; 5061 5062 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5063 #endif 5064 } 5065 5066 static void 5067 vfs_knl_assert_unlocked(void *arg) 5068 { 5069 #ifdef DEBUG_VFS_LOCKS 5070 struct vnode *vp = arg; 5071 5072 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5073 #endif 5074 } 5075 5076 int 5077 vfs_kqfilter(struct vop_kqfilter_args *ap) 5078 { 5079 struct vnode *vp = ap->a_vp; 5080 struct knote *kn = ap->a_kn; 5081 struct knlist *knl; 5082 5083 switch (kn->kn_filter) { 5084 case EVFILT_READ: 5085 kn->kn_fop = &vfsread_filtops; 5086 break; 5087 case EVFILT_WRITE: 5088 kn->kn_fop = &vfswrite_filtops; 5089 break; 5090 case EVFILT_VNODE: 5091 kn->kn_fop = &vfsvnode_filtops; 5092 break; 5093 default: 5094 return (EINVAL); 5095 } 5096 5097 kn->kn_hook = (caddr_t)vp; 5098 5099 v_addpollinfo(vp); 5100 if (vp->v_pollinfo == NULL) 5101 return (ENOMEM); 5102 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5103 vhold(vp); 5104 knlist_add(knl, kn, 0); 5105 5106 return (0); 5107 } 5108 5109 /* 5110 * Detach knote from vnode 5111 */ 5112 static void 5113 filt_vfsdetach(struct knote *kn) 5114 { 5115 struct vnode *vp = (struct vnode *)kn->kn_hook; 5116 5117 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5118 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5119 vdrop(vp); 5120 } 5121 5122 /*ARGSUSED*/ 5123 static int 5124 filt_vfsread(struct knote *kn, long hint) 5125 { 5126 struct vnode *vp = (struct vnode *)kn->kn_hook; 5127 struct vattr va; 5128 int res; 5129 5130 /* 5131 * filesystem is gone, so set the EOF flag and schedule 5132 * the knote for deletion. 5133 */ 5134 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5135 VI_LOCK(vp); 5136 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5137 VI_UNLOCK(vp); 5138 return (1); 5139 } 5140 5141 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5142 return (0); 5143 5144 VI_LOCK(vp); 5145 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5146 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5147 VI_UNLOCK(vp); 5148 return (res); 5149 } 5150 5151 /*ARGSUSED*/ 5152 static int 5153 filt_vfswrite(struct knote *kn, long hint) 5154 { 5155 struct vnode *vp = (struct vnode *)kn->kn_hook; 5156 5157 VI_LOCK(vp); 5158 5159 /* 5160 * filesystem is gone, so set the EOF flag and schedule 5161 * the knote for deletion. 5162 */ 5163 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5164 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5165 5166 kn->kn_data = 0; 5167 VI_UNLOCK(vp); 5168 return (1); 5169 } 5170 5171 static int 5172 filt_vfsvnode(struct knote *kn, long hint) 5173 { 5174 struct vnode *vp = (struct vnode *)kn->kn_hook; 5175 int res; 5176 5177 VI_LOCK(vp); 5178 if (kn->kn_sfflags & hint) 5179 kn->kn_fflags |= hint; 5180 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5181 kn->kn_flags |= EV_EOF; 5182 VI_UNLOCK(vp); 5183 return (1); 5184 } 5185 res = (kn->kn_fflags != 0); 5186 VI_UNLOCK(vp); 5187 return (res); 5188 } 5189 5190 int 5191 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5192 { 5193 int error; 5194 5195 if (dp->d_reclen > ap->a_uio->uio_resid) 5196 return (ENAMETOOLONG); 5197 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5198 if (error) { 5199 if (ap->a_ncookies != NULL) { 5200 if (ap->a_cookies != NULL) 5201 free(ap->a_cookies, M_TEMP); 5202 ap->a_cookies = NULL; 5203 *ap->a_ncookies = 0; 5204 } 5205 return (error); 5206 } 5207 if (ap->a_ncookies == NULL) 5208 return (0); 5209 5210 KASSERT(ap->a_cookies, 5211 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5212 5213 *ap->a_cookies = realloc(*ap->a_cookies, 5214 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5215 (*ap->a_cookies)[*ap->a_ncookies] = off; 5216 *ap->a_ncookies += 1; 5217 return (0); 5218 } 5219 5220 /* 5221 * Mark for update the access time of the file if the filesystem 5222 * supports VOP_MARKATIME. This functionality is used by execve and 5223 * mmap, so we want to avoid the I/O implied by directly setting 5224 * va_atime for the sake of efficiency. 5225 */ 5226 void 5227 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5228 { 5229 struct mount *mp; 5230 5231 mp = vp->v_mount; 5232 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5233 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5234 (void)VOP_MARKATIME(vp); 5235 } 5236 5237 /* 5238 * The purpose of this routine is to remove granularity from accmode_t, 5239 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5240 * VADMIN and VAPPEND. 5241 * 5242 * If it returns 0, the caller is supposed to continue with the usual 5243 * access checks using 'accmode' as modified by this routine. If it 5244 * returns nonzero value, the caller is supposed to return that value 5245 * as errno. 5246 * 5247 * Note that after this routine runs, accmode may be zero. 5248 */ 5249 int 5250 vfs_unixify_accmode(accmode_t *accmode) 5251 { 5252 /* 5253 * There is no way to specify explicit "deny" rule using 5254 * file mode or POSIX.1e ACLs. 5255 */ 5256 if (*accmode & VEXPLICIT_DENY) { 5257 *accmode = 0; 5258 return (0); 5259 } 5260 5261 /* 5262 * None of these can be translated into usual access bits. 5263 * Also, the common case for NFSv4 ACLs is to not contain 5264 * either of these bits. Caller should check for VWRITE 5265 * on the containing directory instead. 5266 */ 5267 if (*accmode & (VDELETE_CHILD | VDELETE)) 5268 return (EPERM); 5269 5270 if (*accmode & VADMIN_PERMS) { 5271 *accmode &= ~VADMIN_PERMS; 5272 *accmode |= VADMIN; 5273 } 5274 5275 /* 5276 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 5277 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 5278 */ 5279 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 5280 5281 return (0); 5282 } 5283 5284 /* 5285 * These are helper functions for filesystems to traverse all 5286 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 5287 * 5288 * This interface replaces MNT_VNODE_FOREACH. 5289 */ 5290 5291 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 5292 5293 struct vnode * 5294 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5295 { 5296 struct vnode *vp; 5297 5298 if (should_yield()) 5299 kern_yield(PRI_USER); 5300 MNT_ILOCK(mp); 5301 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5302 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 5303 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 5304 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5305 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5306 continue; 5307 VI_LOCK(vp); 5308 if ((vp->v_iflag & VI_DOOMED) != 0) { 5309 VI_UNLOCK(vp); 5310 continue; 5311 } 5312 break; 5313 } 5314 if (vp == NULL) { 5315 __mnt_vnode_markerfree_all(mvp, mp); 5316 /* MNT_IUNLOCK(mp); -- done in above function */ 5317 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5318 return (NULL); 5319 } 5320 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5321 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5322 MNT_IUNLOCK(mp); 5323 return (vp); 5324 } 5325 5326 struct vnode * 5327 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5328 { 5329 struct vnode *vp; 5330 5331 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5332 MNT_ILOCK(mp); 5333 MNT_REF(mp); 5334 (*mvp)->v_mount = mp; 5335 (*mvp)->v_type = VMARKER; 5336 5337 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 5338 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5339 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5340 continue; 5341 VI_LOCK(vp); 5342 if ((vp->v_iflag & VI_DOOMED) != 0) { 5343 VI_UNLOCK(vp); 5344 continue; 5345 } 5346 break; 5347 } 5348 if (vp == NULL) { 5349 MNT_REL(mp); 5350 MNT_IUNLOCK(mp); 5351 free(*mvp, M_VNODE_MARKER); 5352 *mvp = NULL; 5353 return (NULL); 5354 } 5355 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5356 MNT_IUNLOCK(mp); 5357 return (vp); 5358 } 5359 5360 void 5361 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5362 { 5363 5364 if (*mvp == NULL) { 5365 MNT_IUNLOCK(mp); 5366 return; 5367 } 5368 5369 mtx_assert(MNT_MTX(mp), MA_OWNED); 5370 5371 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5372 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5373 MNT_REL(mp); 5374 MNT_IUNLOCK(mp); 5375 free(*mvp, M_VNODE_MARKER); 5376 *mvp = NULL; 5377 } 5378 5379 /* 5380 * These are helper functions for filesystems to traverse their 5381 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5382 */ 5383 static void 5384 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5385 { 5386 5387 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5388 5389 MNT_ILOCK(mp); 5390 MNT_REL(mp); 5391 MNT_IUNLOCK(mp); 5392 free(*mvp, M_VNODE_MARKER); 5393 *mvp = NULL; 5394 } 5395 5396 /* 5397 * Relock the mp mount vnode list lock with the vp vnode interlock in the 5398 * conventional lock order during mnt_vnode_next_active iteration. 5399 * 5400 * On entry, the mount vnode list lock is held and the vnode interlock is not. 5401 * The list lock is dropped and reacquired. On success, both locks are held. 5402 * On failure, the mount vnode list lock is held but the vnode interlock is 5403 * not, and the procedure may have yielded. 5404 */ 5405 static bool 5406 mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp, 5407 struct vnode *vp) 5408 { 5409 const struct vnode *tmp; 5410 bool held, ret; 5411 5412 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 5413 TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp, 5414 ("%s: bad marker", __func__)); 5415 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 5416 ("%s: inappropriate vnode", __func__)); 5417 ASSERT_VI_UNLOCKED(vp, __func__); 5418 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5419 5420 ret = false; 5421 5422 TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist); 5423 TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist); 5424 5425 /* 5426 * Use a hold to prevent vp from disappearing while the mount vnode 5427 * list lock is dropped and reacquired. Normally a hold would be 5428 * acquired with vhold(), but that might try to acquire the vnode 5429 * interlock, which would be a LOR with the mount vnode list lock. 5430 */ 5431 held = refcount_acquire_if_not_zero(&vp->v_holdcnt); 5432 mtx_unlock(&mp->mnt_listmtx); 5433 if (!held) 5434 goto abort; 5435 VI_LOCK(vp); 5436 if (!refcount_release_if_not_last(&vp->v_holdcnt)) { 5437 vdropl(vp); 5438 goto abort; 5439 } 5440 mtx_lock(&mp->mnt_listmtx); 5441 5442 /* 5443 * Determine whether the vnode is still the next one after the marker, 5444 * excepting any other markers. If the vnode has not been doomed by 5445 * vgone() then the hold should have ensured that it remained on the 5446 * active list. If it has been doomed but is still on the active list, 5447 * don't abort, but rather skip over it (avoid spinning on doomed 5448 * vnodes). 5449 */ 5450 tmp = mvp; 5451 do { 5452 tmp = TAILQ_NEXT(tmp, v_actfreelist); 5453 } while (tmp != NULL && tmp->v_type == VMARKER); 5454 if (tmp != vp) { 5455 mtx_unlock(&mp->mnt_listmtx); 5456 VI_UNLOCK(vp); 5457 goto abort; 5458 } 5459 5460 ret = true; 5461 goto out; 5462 abort: 5463 maybe_yield(); 5464 mtx_lock(&mp->mnt_listmtx); 5465 out: 5466 if (ret) 5467 ASSERT_VI_LOCKED(vp, __func__); 5468 else 5469 ASSERT_VI_UNLOCKED(vp, __func__); 5470 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5471 return (ret); 5472 } 5473 5474 static struct vnode * 5475 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5476 { 5477 struct vnode *vp, *nvp; 5478 5479 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5480 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5481 restart: 5482 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5483 while (vp != NULL) { 5484 if (vp->v_type == VMARKER) { 5485 vp = TAILQ_NEXT(vp, v_actfreelist); 5486 continue; 5487 } 5488 /* 5489 * Try-lock because this is the wrong lock order. If that does 5490 * not succeed, drop the mount vnode list lock and try to 5491 * reacquire it and the vnode interlock in the right order. 5492 */ 5493 if (!VI_TRYLOCK(vp) && 5494 !mnt_vnode_next_active_relock(*mvp, mp, vp)) 5495 goto restart; 5496 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5497 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5498 ("alien vnode on the active list %p %p", vp, mp)); 5499 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) 5500 break; 5501 nvp = TAILQ_NEXT(vp, v_actfreelist); 5502 VI_UNLOCK(vp); 5503 vp = nvp; 5504 } 5505 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5506 5507 /* Check if we are done */ 5508 if (vp == NULL) { 5509 mtx_unlock(&mp->mnt_listmtx); 5510 mnt_vnode_markerfree_active(mvp, mp); 5511 return (NULL); 5512 } 5513 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 5514 mtx_unlock(&mp->mnt_listmtx); 5515 ASSERT_VI_LOCKED(vp, "active iter"); 5516 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 5517 return (vp); 5518 } 5519 5520 struct vnode * 5521 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5522 { 5523 5524 if (should_yield()) 5525 kern_yield(PRI_USER); 5526 mtx_lock(&mp->mnt_listmtx); 5527 return (mnt_vnode_next_active(mvp, mp)); 5528 } 5529 5530 struct vnode * 5531 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 5532 { 5533 struct vnode *vp; 5534 5535 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5536 MNT_ILOCK(mp); 5537 MNT_REF(mp); 5538 MNT_IUNLOCK(mp); 5539 (*mvp)->v_type = VMARKER; 5540 (*mvp)->v_mount = mp; 5541 5542 mtx_lock(&mp->mnt_listmtx); 5543 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 5544 if (vp == NULL) { 5545 mtx_unlock(&mp->mnt_listmtx); 5546 mnt_vnode_markerfree_active(mvp, mp); 5547 return (NULL); 5548 } 5549 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5550 return (mnt_vnode_next_active(mvp, mp)); 5551 } 5552 5553 void 5554 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5555 { 5556 5557 if (*mvp == NULL) 5558 return; 5559 5560 mtx_lock(&mp->mnt_listmtx); 5561 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5562 mtx_unlock(&mp->mnt_listmtx); 5563 mnt_vnode_markerfree_active(mvp, mp); 5564 } 5565