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_compat.h" 47 #include "opt_ddb.h" 48 #include "opt_watchdog.h" 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/bio.h> 53 #include <sys/buf.h> 54 #include <sys/condvar.h> 55 #include <sys/conf.h> 56 #include <sys/counter.h> 57 #include <sys/dirent.h> 58 #include <sys/event.h> 59 #include <sys/eventhandler.h> 60 #include <sys/extattr.h> 61 #include <sys/file.h> 62 #include <sys/fcntl.h> 63 #include <sys/jail.h> 64 #include <sys/kdb.h> 65 #include <sys/kernel.h> 66 #include <sys/kthread.h> 67 #include <sys/lockf.h> 68 #include <sys/malloc.h> 69 #include <sys/mount.h> 70 #include <sys/namei.h> 71 #include <sys/pctrie.h> 72 #include <sys/priv.h> 73 #include <sys/reboot.h> 74 #include <sys/refcount.h> 75 #include <sys/rwlock.h> 76 #include <sys/sched.h> 77 #include <sys/sleepqueue.h> 78 #include <sys/smp.h> 79 #include <sys/stat.h> 80 #include <sys/sysctl.h> 81 #include <sys/syslog.h> 82 #include <sys/vmmeter.h> 83 #include <sys/vnode.h> 84 #include <sys/watchdog.h> 85 86 #include <machine/stdarg.h> 87 88 #include <security/mac/mac_framework.h> 89 90 #include <vm/vm.h> 91 #include <vm/vm_object.h> 92 #include <vm/vm_extern.h> 93 #include <vm/pmap.h> 94 #include <vm/vm_map.h> 95 #include <vm/vm_page.h> 96 #include <vm/vm_kern.h> 97 #include <vm/uma.h> 98 99 #ifdef DDB 100 #include <ddb/ddb.h> 101 #endif 102 103 static void delmntque(struct vnode *vp); 104 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 105 int slpflag, int slptimeo); 106 static void syncer_shutdown(void *arg, int howto); 107 static int vtryrecycle(struct vnode *vp); 108 static void v_init_counters(struct vnode *); 109 static void v_incr_usecount(struct vnode *); 110 static void v_incr_usecount_locked(struct vnode *); 111 static void v_incr_devcount(struct vnode *); 112 static void v_decr_devcount(struct vnode *); 113 static void vgonel(struct vnode *); 114 static void vfs_knllock(void *arg); 115 static void vfs_knlunlock(void *arg); 116 static void vfs_knl_assert_locked(void *arg); 117 static void vfs_knl_assert_unlocked(void *arg); 118 static void vnlru_return_batches(struct vfsops *mnt_op); 119 static void destroy_vpollinfo(struct vpollinfo *vi); 120 121 /* 122 * Number of vnodes in existence. Increased whenever getnewvnode() 123 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode. 124 */ 125 static unsigned long numvnodes; 126 127 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 128 "Number of vnodes in existence"); 129 130 static counter_u64_t vnodes_created; 131 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 132 "Number of vnodes created by getnewvnode"); 133 134 static u_long mnt_free_list_batch = 128; 135 SYSCTL_ULONG(_vfs, OID_AUTO, mnt_free_list_batch, CTLFLAG_RW, 136 &mnt_free_list_batch, 0, "Limit of vnodes held on mnt's free list"); 137 138 /* 139 * Conversion tables for conversion from vnode types to inode formats 140 * and back. 141 */ 142 enum vtype iftovt_tab[16] = { 143 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 144 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 145 }; 146 int vttoif_tab[10] = { 147 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 148 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 149 }; 150 151 /* 152 * List of vnodes that are ready for recycling. 153 */ 154 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 155 156 /* 157 * "Free" vnode target. Free vnodes are rarely completely free, but are 158 * just ones that are cheap to recycle. Usually they are for files which 159 * have been stat'd but not read; these usually have inode and namecache 160 * data attached to them. This target is the preferred minimum size of a 161 * sub-cache consisting mostly of such files. The system balances the size 162 * of this sub-cache with its complement to try to prevent either from 163 * thrashing while the other is relatively inactive. The targets express 164 * a preference for the best balance. 165 * 166 * "Above" this target there are 2 further targets (watermarks) related 167 * to recyling of free vnodes. In the best-operating case, the cache is 168 * exactly full, the free list has size between vlowat and vhiwat above the 169 * free target, and recycling from it and normal use maintains this state. 170 * Sometimes the free list is below vlowat or even empty, but this state 171 * is even better for immediate use provided the cache is not full. 172 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 173 * ones) to reach one of these states. The watermarks are currently hard- 174 * coded as 4% and 9% of the available space higher. These and the default 175 * of 25% for wantfreevnodes are too large if the memory size is large. 176 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 177 * whenever vnlru_proc() becomes active. 178 */ 179 static u_long wantfreevnodes; 180 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, 181 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes"); 182 static u_long freevnodes; 183 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 184 &freevnodes, 0, "Number of \"free\" vnodes"); 185 186 static counter_u64_t recycles_count; 187 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 188 "Number of vnodes recycled to meet vnode cache targets"); 189 190 /* 191 * Various variables used for debugging the new implementation of 192 * reassignbuf(). 193 * XXX these are probably of (very) limited utility now. 194 */ 195 static int reassignbufcalls; 196 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, 197 "Number of calls to reassignbuf"); 198 199 static counter_u64_t free_owe_inact; 200 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, 201 "Number of times free vnodes kept on active list due to VFS " 202 "owing inactivation"); 203 204 /* To keep more than one thread at a time from running vfs_getnewfsid */ 205 static struct mtx mntid_mtx; 206 207 /* 208 * Lock for any access to the following: 209 * vnode_free_list 210 * numvnodes 211 * freevnodes 212 */ 213 static struct mtx vnode_free_list_mtx; 214 215 /* Publicly exported FS */ 216 struct nfs_public nfs_pub; 217 218 static uma_zone_t buf_trie_zone; 219 220 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 221 static uma_zone_t vnode_zone; 222 static uma_zone_t vnodepoll_zone; 223 224 /* 225 * The workitem queue. 226 * 227 * It is useful to delay writes of file data and filesystem metadata 228 * for tens of seconds so that quickly created and deleted files need 229 * not waste disk bandwidth being created and removed. To realize this, 230 * we append vnodes to a "workitem" queue. When running with a soft 231 * updates implementation, most pending metadata dependencies should 232 * not wait for more than a few seconds. Thus, mounted on block devices 233 * are delayed only about a half the time that file data is delayed. 234 * Similarly, directory updates are more critical, so are only delayed 235 * about a third the time that file data is delayed. Thus, there are 236 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 237 * one each second (driven off the filesystem syncer process). The 238 * syncer_delayno variable indicates the next queue that is to be processed. 239 * Items that need to be processed soon are placed in this queue: 240 * 241 * syncer_workitem_pending[syncer_delayno] 242 * 243 * A delay of fifteen seconds is done by placing the request fifteen 244 * entries later in the queue: 245 * 246 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 247 * 248 */ 249 static int syncer_delayno; 250 static long syncer_mask; 251 LIST_HEAD(synclist, bufobj); 252 static struct synclist *syncer_workitem_pending; 253 /* 254 * The sync_mtx protects: 255 * bo->bo_synclist 256 * sync_vnode_count 257 * syncer_delayno 258 * syncer_state 259 * syncer_workitem_pending 260 * syncer_worklist_len 261 * rushjob 262 */ 263 static struct mtx sync_mtx; 264 static struct cv sync_wakeup; 265 266 #define SYNCER_MAXDELAY 32 267 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 268 static int syncdelay = 30; /* max time to delay syncing data */ 269 static int filedelay = 30; /* time to delay syncing files */ 270 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 271 "Time to delay syncing files (in seconds)"); 272 static int dirdelay = 29; /* time to delay syncing directories */ 273 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 274 "Time to delay syncing directories (in seconds)"); 275 static int metadelay = 28; /* time to delay syncing metadata */ 276 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 277 "Time to delay syncing metadata (in seconds)"); 278 static int rushjob; /* number of slots to run ASAP */ 279 static int stat_rush_requests; /* number of times I/O speeded up */ 280 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 281 "Number of times I/O speeded up (rush requests)"); 282 283 /* 284 * When shutting down the syncer, run it at four times normal speed. 285 */ 286 #define SYNCER_SHUTDOWN_SPEEDUP 4 287 static int sync_vnode_count; 288 static int syncer_worklist_len; 289 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 290 syncer_state; 291 292 /* Target for maximum number of vnodes. */ 293 int desiredvnodes; 294 static int gapvnodes; /* gap between wanted and desired */ 295 static int vhiwat; /* enough extras after expansion */ 296 static int vlowat; /* minimal extras before expansion */ 297 static int vstir; /* nonzero to stir non-free vnodes */ 298 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 299 300 static int 301 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS) 302 { 303 int error, old_desiredvnodes; 304 305 old_desiredvnodes = desiredvnodes; 306 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0) 307 return (error); 308 if (old_desiredvnodes != desiredvnodes) { 309 wantfreevnodes = desiredvnodes / 4; 310 /* XXX locking seems to be incomplete. */ 311 vfs_hash_changesize(desiredvnodes); 312 cache_changesize(desiredvnodes); 313 } 314 return (0); 315 } 316 317 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 318 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0, 319 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes"); 320 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 321 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 322 static int vnlru_nowhere; 323 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 324 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 325 326 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 327 static int vnsz2log; 328 329 /* 330 * Support for the bufobj clean & dirty pctrie. 331 */ 332 static void * 333 buf_trie_alloc(struct pctrie *ptree) 334 { 335 336 return uma_zalloc(buf_trie_zone, M_NOWAIT); 337 } 338 339 static void 340 buf_trie_free(struct pctrie *ptree, void *node) 341 { 342 343 uma_zfree(buf_trie_zone, node); 344 } 345 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 346 347 /* 348 * Initialize the vnode management data structures. 349 * 350 * Reevaluate the following cap on the number of vnodes after the physical 351 * memory size exceeds 512GB. In the limit, as the physical memory size 352 * grows, the ratio of the memory size in KB to vnodes approaches 64:1. 353 */ 354 #ifndef MAXVNODES_MAX 355 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */ 356 #endif 357 358 /* 359 * Initialize a vnode as it first enters the zone. 360 */ 361 static int 362 vnode_init(void *mem, int size, int flags) 363 { 364 struct vnode *vp; 365 struct bufobj *bo; 366 367 vp = mem; 368 bzero(vp, size); 369 /* 370 * Setup locks. 371 */ 372 vp->v_vnlock = &vp->v_lock; 373 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 374 /* 375 * By default, don't allow shared locks unless filesystems opt-in. 376 */ 377 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 378 LK_NOSHARE | LK_IS_VNODE); 379 /* 380 * Initialize bufobj. 381 */ 382 bo = &vp->v_bufobj; 383 rw_init(BO_LOCKPTR(bo), "bufobj interlock"); 384 bo->bo_private = vp; 385 TAILQ_INIT(&bo->bo_clean.bv_hd); 386 TAILQ_INIT(&bo->bo_dirty.bv_hd); 387 /* 388 * Initialize namecache. 389 */ 390 LIST_INIT(&vp->v_cache_src); 391 TAILQ_INIT(&vp->v_cache_dst); 392 /* 393 * Initialize rangelocks. 394 */ 395 rangelock_init(&vp->v_rl); 396 return (0); 397 } 398 399 /* 400 * Free a vnode when it is cleared from the zone. 401 */ 402 static void 403 vnode_fini(void *mem, int size) 404 { 405 struct vnode *vp; 406 struct bufobj *bo; 407 408 vp = mem; 409 rangelock_destroy(&vp->v_rl); 410 lockdestroy(vp->v_vnlock); 411 mtx_destroy(&vp->v_interlock); 412 bo = &vp->v_bufobj; 413 rw_destroy(BO_LOCKPTR(bo)); 414 } 415 416 /* 417 * Provide the size of NFS nclnode and NFS fh for calculation of the 418 * vnode memory consumption. The size is specified directly to 419 * eliminate dependency on NFS-private header. 420 * 421 * Other filesystems may use bigger or smaller (like UFS and ZFS) 422 * private inode data, but the NFS-based estimation is ample enough. 423 * Still, we care about differences in the size between 64- and 32-bit 424 * platforms. 425 * 426 * Namecache structure size is heuristically 427 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 428 */ 429 #ifdef _LP64 430 #define NFS_NCLNODE_SZ (528 + 64) 431 #define NC_SZ 148 432 #else 433 #define NFS_NCLNODE_SZ (360 + 32) 434 #define NC_SZ 92 435 #endif 436 437 static void 438 vntblinit(void *dummy __unused) 439 { 440 u_int i; 441 int physvnodes, virtvnodes; 442 443 /* 444 * Desiredvnodes is a function of the physical memory size and the 445 * kernel's heap size. Generally speaking, it scales with the 446 * physical memory size. The ratio of desiredvnodes to the physical 447 * memory size is 1:16 until desiredvnodes exceeds 98,304. 448 * Thereafter, the 449 * marginal ratio of desiredvnodes to the physical memory size is 450 * 1:64. However, desiredvnodes is limited by the kernel's heap 451 * size. The memory required by desiredvnodes vnodes and vm objects 452 * must not exceed 1/10th of the kernel's heap size. 453 */ 454 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 455 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 456 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 457 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 458 desiredvnodes = min(physvnodes, virtvnodes); 459 if (desiredvnodes > MAXVNODES_MAX) { 460 if (bootverbose) 461 printf("Reducing kern.maxvnodes %d -> %d\n", 462 desiredvnodes, MAXVNODES_MAX); 463 desiredvnodes = MAXVNODES_MAX; 464 } 465 wantfreevnodes = desiredvnodes / 4; 466 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 467 TAILQ_INIT(&vnode_free_list); 468 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 469 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 470 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 471 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 472 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 473 /* 474 * Preallocate enough nodes to support one-per buf so that 475 * we can not fail an insert. reassignbuf() callers can not 476 * tolerate the insertion failure. 477 */ 478 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 479 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 480 UMA_ZONE_NOFREE | UMA_ZONE_VM); 481 uma_prealloc(buf_trie_zone, nbuf); 482 483 vnodes_created = counter_u64_alloc(M_WAITOK); 484 recycles_count = counter_u64_alloc(M_WAITOK); 485 free_owe_inact = counter_u64_alloc(M_WAITOK); 486 487 /* 488 * Initialize the filesystem syncer. 489 */ 490 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 491 &syncer_mask); 492 syncer_maxdelay = syncer_mask + 1; 493 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 494 cv_init(&sync_wakeup, "syncer"); 495 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 496 vnsz2log++; 497 vnsz2log--; 498 } 499 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 500 501 502 /* 503 * Mark a mount point as busy. Used to synchronize access and to delay 504 * unmounting. Eventually, mountlist_mtx is not released on failure. 505 * 506 * vfs_busy() is a custom lock, it can block the caller. 507 * vfs_busy() only sleeps if the unmount is active on the mount point. 508 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 509 * vnode belonging to mp. 510 * 511 * Lookup uses vfs_busy() to traverse mount points. 512 * root fs var fs 513 * / vnode lock A / vnode lock (/var) D 514 * /var vnode lock B /log vnode lock(/var/log) E 515 * vfs_busy lock C vfs_busy lock F 516 * 517 * Within each file system, the lock order is C->A->B and F->D->E. 518 * 519 * When traversing across mounts, the system follows that lock order: 520 * 521 * C->A->B 522 * | 523 * +->F->D->E 524 * 525 * The lookup() process for namei("/var") illustrates the process: 526 * VOP_LOOKUP() obtains B while A is held 527 * vfs_busy() obtains a shared lock on F while A and B are held 528 * vput() releases lock on B 529 * vput() releases lock on A 530 * VFS_ROOT() obtains lock on D while shared lock on F is held 531 * vfs_unbusy() releases shared lock on F 532 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 533 * Attempt to lock A (instead of vp_crossmp) while D is held would 534 * violate the global order, causing deadlocks. 535 * 536 * dounmount() locks B while F is drained. 537 */ 538 int 539 vfs_busy(struct mount *mp, int flags) 540 { 541 542 MPASS((flags & ~MBF_MASK) == 0); 543 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 544 545 MNT_ILOCK(mp); 546 MNT_REF(mp); 547 /* 548 * If mount point is currently being unmounted, sleep until the 549 * mount point fate is decided. If thread doing the unmounting fails, 550 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 551 * that this mount point has survived the unmount attempt and vfs_busy 552 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 553 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 554 * about to be really destroyed. vfs_busy needs to release its 555 * reference on the mount point in this case and return with ENOENT, 556 * telling the caller that mount mount it tried to busy is no longer 557 * valid. 558 */ 559 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 560 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 561 MNT_REL(mp); 562 MNT_IUNLOCK(mp); 563 CTR1(KTR_VFS, "%s: failed busying before sleeping", 564 __func__); 565 return (ENOENT); 566 } 567 if (flags & MBF_MNTLSTLOCK) 568 mtx_unlock(&mountlist_mtx); 569 mp->mnt_kern_flag |= MNTK_MWAIT; 570 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 571 if (flags & MBF_MNTLSTLOCK) 572 mtx_lock(&mountlist_mtx); 573 MNT_ILOCK(mp); 574 } 575 if (flags & MBF_MNTLSTLOCK) 576 mtx_unlock(&mountlist_mtx); 577 mp->mnt_lockref++; 578 MNT_IUNLOCK(mp); 579 return (0); 580 } 581 582 /* 583 * Free a busy filesystem. 584 */ 585 void 586 vfs_unbusy(struct mount *mp) 587 { 588 589 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 590 MNT_ILOCK(mp); 591 MNT_REL(mp); 592 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref")); 593 mp->mnt_lockref--; 594 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 595 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 596 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 597 mp->mnt_kern_flag &= ~MNTK_DRAINING; 598 wakeup(&mp->mnt_lockref); 599 } 600 MNT_IUNLOCK(mp); 601 } 602 603 /* 604 * Lookup a mount point by filesystem identifier. 605 */ 606 struct mount * 607 vfs_getvfs(fsid_t *fsid) 608 { 609 struct mount *mp; 610 611 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 612 mtx_lock(&mountlist_mtx); 613 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 614 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 615 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 616 vfs_ref(mp); 617 mtx_unlock(&mountlist_mtx); 618 return (mp); 619 } 620 } 621 mtx_unlock(&mountlist_mtx); 622 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 623 return ((struct mount *) 0); 624 } 625 626 /* 627 * Lookup a mount point by filesystem identifier, busying it before 628 * returning. 629 * 630 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 631 * cache for popular filesystem identifiers. The cache is lockess, using 632 * the fact that struct mount's are never freed. In worst case we may 633 * get pointer to unmounted or even different filesystem, so we have to 634 * check what we got, and go slow way if so. 635 */ 636 struct mount * 637 vfs_busyfs(fsid_t *fsid) 638 { 639 #define FSID_CACHE_SIZE 256 640 typedef struct mount * volatile vmp_t; 641 static vmp_t cache[FSID_CACHE_SIZE]; 642 struct mount *mp; 643 int error; 644 uint32_t hash; 645 646 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 647 hash = fsid->val[0] ^ fsid->val[1]; 648 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 649 mp = cache[hash]; 650 if (mp == NULL || 651 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 652 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 653 goto slow; 654 if (vfs_busy(mp, 0) != 0) { 655 cache[hash] = NULL; 656 goto slow; 657 } 658 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 659 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 660 return (mp); 661 else 662 vfs_unbusy(mp); 663 664 slow: 665 mtx_lock(&mountlist_mtx); 666 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 667 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 668 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 669 error = vfs_busy(mp, MBF_MNTLSTLOCK); 670 if (error) { 671 cache[hash] = NULL; 672 mtx_unlock(&mountlist_mtx); 673 return (NULL); 674 } 675 cache[hash] = mp; 676 return (mp); 677 } 678 } 679 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 680 mtx_unlock(&mountlist_mtx); 681 return ((struct mount *) 0); 682 } 683 684 /* 685 * Check if a user can access privileged mount options. 686 */ 687 int 688 vfs_suser(struct mount *mp, struct thread *td) 689 { 690 int error; 691 692 /* 693 * If the thread is jailed, but this is not a jail-friendly file 694 * system, deny immediately. 695 */ 696 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred)) 697 return (EPERM); 698 699 /* 700 * If the file system was mounted outside the jail of the calling 701 * thread, deny immediately. 702 */ 703 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 704 return (EPERM); 705 706 /* 707 * If file system supports delegated administration, we don't check 708 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 709 * by the file system itself. 710 * If this is not the user that did original mount, we check for 711 * the PRIV_VFS_MOUNT_OWNER privilege. 712 */ 713 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 714 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 715 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 716 return (error); 717 } 718 return (0); 719 } 720 721 /* 722 * Get a new unique fsid. Try to make its val[0] unique, since this value 723 * will be used to create fake device numbers for stat(). Also try (but 724 * not so hard) make its val[0] unique mod 2^16, since some emulators only 725 * support 16-bit device numbers. We end up with unique val[0]'s for the 726 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 727 * 728 * Keep in mind that several mounts may be running in parallel. Starting 729 * the search one past where the previous search terminated is both a 730 * micro-optimization and a defense against returning the same fsid to 731 * different mounts. 732 */ 733 void 734 vfs_getnewfsid(struct mount *mp) 735 { 736 static uint16_t mntid_base; 737 struct mount *nmp; 738 fsid_t tfsid; 739 int mtype; 740 741 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 742 mtx_lock(&mntid_mtx); 743 mtype = mp->mnt_vfc->vfc_typenum; 744 tfsid.val[1] = mtype; 745 mtype = (mtype & 0xFF) << 24; 746 for (;;) { 747 tfsid.val[0] = makedev(255, 748 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 749 mntid_base++; 750 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 751 break; 752 vfs_rel(nmp); 753 } 754 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 755 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 756 mtx_unlock(&mntid_mtx); 757 } 758 759 /* 760 * Knob to control the precision of file timestamps: 761 * 762 * 0 = seconds only; nanoseconds zeroed. 763 * 1 = seconds and nanoseconds, accurate within 1/HZ. 764 * 2 = seconds and nanoseconds, truncated to microseconds. 765 * >=3 = seconds and nanoseconds, maximum precision. 766 */ 767 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 768 769 static int timestamp_precision = TSP_USEC; 770 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 771 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 772 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 773 "3+: sec + ns (max. precision))"); 774 775 /* 776 * Get a current timestamp. 777 */ 778 void 779 vfs_timestamp(struct timespec *tsp) 780 { 781 struct timeval tv; 782 783 switch (timestamp_precision) { 784 case TSP_SEC: 785 tsp->tv_sec = time_second; 786 tsp->tv_nsec = 0; 787 break; 788 case TSP_HZ: 789 getnanotime(tsp); 790 break; 791 case TSP_USEC: 792 microtime(&tv); 793 TIMEVAL_TO_TIMESPEC(&tv, tsp); 794 break; 795 case TSP_NSEC: 796 default: 797 nanotime(tsp); 798 break; 799 } 800 } 801 802 /* 803 * Set vnode attributes to VNOVAL 804 */ 805 void 806 vattr_null(struct vattr *vap) 807 { 808 809 vap->va_type = VNON; 810 vap->va_size = VNOVAL; 811 vap->va_bytes = VNOVAL; 812 vap->va_mode = VNOVAL; 813 vap->va_nlink = VNOVAL; 814 vap->va_uid = VNOVAL; 815 vap->va_gid = VNOVAL; 816 vap->va_fsid = VNOVAL; 817 vap->va_fileid = VNOVAL; 818 vap->va_blocksize = VNOVAL; 819 vap->va_rdev = VNOVAL; 820 vap->va_atime.tv_sec = VNOVAL; 821 vap->va_atime.tv_nsec = VNOVAL; 822 vap->va_mtime.tv_sec = VNOVAL; 823 vap->va_mtime.tv_nsec = VNOVAL; 824 vap->va_ctime.tv_sec = VNOVAL; 825 vap->va_ctime.tv_nsec = VNOVAL; 826 vap->va_birthtime.tv_sec = VNOVAL; 827 vap->va_birthtime.tv_nsec = VNOVAL; 828 vap->va_flags = VNOVAL; 829 vap->va_gen = VNOVAL; 830 vap->va_vaflags = 0; 831 } 832 833 /* 834 * This routine is called when we have too many vnodes. It attempts 835 * to free <count> vnodes and will potentially free vnodes that still 836 * have VM backing store (VM backing store is typically the cause 837 * of a vnode blowout so we want to do this). Therefore, this operation 838 * is not considered cheap. 839 * 840 * A number of conditions may prevent a vnode from being reclaimed. 841 * the buffer cache may have references on the vnode, a directory 842 * vnode may still have references due to the namei cache representing 843 * underlying files, or the vnode may be in active use. It is not 844 * desirable to reuse such vnodes. These conditions may cause the 845 * number of vnodes to reach some minimum value regardless of what 846 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 847 */ 848 static int 849 vlrureclaim(struct mount *mp, int reclaim_nc_src, int trigger) 850 { 851 struct vnode *vp; 852 int count, done, target; 853 854 done = 0; 855 vn_start_write(NULL, &mp, V_WAIT); 856 MNT_ILOCK(mp); 857 count = mp->mnt_nvnodelistsize; 858 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1); 859 target = target / 10 + 1; 860 while (count != 0 && done < target) { 861 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 862 while (vp != NULL && vp->v_type == VMARKER) 863 vp = TAILQ_NEXT(vp, v_nmntvnodes); 864 if (vp == NULL) 865 break; 866 /* 867 * XXX LRU is completely broken for non-free vnodes. First 868 * by calling here in mountpoint order, then by moving 869 * unselected vnodes to the end here, and most grossly by 870 * removing the vlruvp() function that was supposed to 871 * maintain the order. (This function was born broken 872 * since syncer problems prevented it doing anything.) The 873 * order is closer to LRC (C = Created). 874 * 875 * LRU reclaiming of vnodes seems to have last worked in 876 * FreeBSD-3 where LRU wasn't mentioned under any spelling. 877 * Then there was no hold count, and inactive vnodes were 878 * simply put on the free list in LRU order. The separate 879 * lists also break LRU. We prefer to reclaim from the 880 * free list for technical reasons. This tends to thrash 881 * the free list to keep very unrecently used held vnodes. 882 * The problem is mitigated by keeping the free list large. 883 */ 884 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 885 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 886 --count; 887 if (!VI_TRYLOCK(vp)) 888 goto next_iter; 889 /* 890 * If it's been deconstructed already, it's still 891 * referenced, or it exceeds the trigger, skip it. 892 * Also skip free vnodes. We are trying to make space 893 * to expand the free list, not reduce it. 894 */ 895 if (vp->v_usecount || 896 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 897 ((vp->v_iflag & VI_FREE) != 0) || 898 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 899 vp->v_object->resident_page_count > trigger)) { 900 VI_UNLOCK(vp); 901 goto next_iter; 902 } 903 MNT_IUNLOCK(mp); 904 vholdl(vp); 905 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 906 vdrop(vp); 907 goto next_iter_mntunlocked; 908 } 909 VI_LOCK(vp); 910 /* 911 * v_usecount may have been bumped after VOP_LOCK() dropped 912 * the vnode interlock and before it was locked again. 913 * 914 * It is not necessary to recheck VI_DOOMED because it can 915 * only be set by another thread that holds both the vnode 916 * lock and vnode interlock. If another thread has the 917 * vnode lock before we get to VOP_LOCK() and obtains the 918 * vnode interlock after VOP_LOCK() drops the vnode 919 * interlock, the other thread will be unable to drop the 920 * vnode lock before our VOP_LOCK() call fails. 921 */ 922 if (vp->v_usecount || 923 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 924 (vp->v_iflag & VI_FREE) != 0 || 925 (vp->v_object != NULL && 926 vp->v_object->resident_page_count > trigger)) { 927 VOP_UNLOCK(vp, LK_INTERLOCK); 928 vdrop(vp); 929 goto next_iter_mntunlocked; 930 } 931 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 932 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 933 counter_u64_add(recycles_count, 1); 934 vgonel(vp); 935 VOP_UNLOCK(vp, 0); 936 vdropl(vp); 937 done++; 938 next_iter_mntunlocked: 939 if (!should_yield()) 940 goto relock_mnt; 941 goto yield; 942 next_iter: 943 if (!should_yield()) 944 continue; 945 MNT_IUNLOCK(mp); 946 yield: 947 kern_yield(PRI_USER); 948 relock_mnt: 949 MNT_ILOCK(mp); 950 } 951 MNT_IUNLOCK(mp); 952 vn_finished_write(mp); 953 return done; 954 } 955 956 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 957 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 958 0, 959 "limit on vnode free requests per call to the vnlru_free routine"); 960 961 /* 962 * Attempt to reduce the free list by the requested amount. 963 */ 964 static void 965 vnlru_free_locked(int count, struct vfsops *mnt_op) 966 { 967 struct vnode *vp; 968 struct mount *mp; 969 bool tried_batches; 970 971 tried_batches = false; 972 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 973 if (count > max_vnlru_free) 974 count = max_vnlru_free; 975 for (; count > 0; count--) { 976 vp = TAILQ_FIRST(&vnode_free_list); 977 /* 978 * The list can be modified while the free_list_mtx 979 * has been dropped and vp could be NULL here. 980 */ 981 if (vp == NULL) { 982 if (tried_batches) 983 break; 984 mtx_unlock(&vnode_free_list_mtx); 985 vnlru_return_batches(mnt_op); 986 tried_batches = true; 987 mtx_lock(&vnode_free_list_mtx); 988 continue; 989 } 990 991 VNASSERT(vp->v_op != NULL, vp, 992 ("vnlru_free: vnode already reclaimed.")); 993 KASSERT((vp->v_iflag & VI_FREE) != 0, 994 ("Removing vnode not on freelist")); 995 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 996 ("Mangling active vnode")); 997 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 998 999 /* 1000 * Don't recycle if our vnode is from different type 1001 * of mount point. Note that mp is type-safe, the 1002 * check does not reach unmapped address even if 1003 * vnode is reclaimed. 1004 * Don't recycle if we can't get the interlock without 1005 * blocking. 1006 */ 1007 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL && 1008 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1009 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist); 1010 continue; 1011 } 1012 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0, 1013 vp, ("vp inconsistent on freelist")); 1014 1015 /* 1016 * The clear of VI_FREE prevents activation of the 1017 * vnode. There is no sense in putting the vnode on 1018 * the mount point active list, only to remove it 1019 * later during recycling. Inline the relevant part 1020 * of vholdl(), to avoid triggering assertions or 1021 * activating. 1022 */ 1023 freevnodes--; 1024 vp->v_iflag &= ~VI_FREE; 1025 refcount_acquire(&vp->v_holdcnt); 1026 1027 mtx_unlock(&vnode_free_list_mtx); 1028 VI_UNLOCK(vp); 1029 vtryrecycle(vp); 1030 /* 1031 * If the recycled succeeded this vdrop will actually free 1032 * the vnode. If not it will simply place it back on 1033 * the free list. 1034 */ 1035 vdrop(vp); 1036 mtx_lock(&vnode_free_list_mtx); 1037 } 1038 } 1039 1040 void 1041 vnlru_free(int count, struct vfsops *mnt_op) 1042 { 1043 1044 mtx_lock(&vnode_free_list_mtx); 1045 vnlru_free_locked(count, mnt_op); 1046 mtx_unlock(&vnode_free_list_mtx); 1047 } 1048 1049 1050 /* XXX some names and initialization are bad for limits and watermarks. */ 1051 static int 1052 vspace(void) 1053 { 1054 int space; 1055 1056 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1057 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1058 vlowat = vhiwat / 2; 1059 if (numvnodes > desiredvnodes) 1060 return (0); 1061 space = desiredvnodes - numvnodes; 1062 if (freevnodes > wantfreevnodes) 1063 space += freevnodes - wantfreevnodes; 1064 return (space); 1065 } 1066 1067 static void 1068 vnlru_return_batch_locked(struct mount *mp) 1069 { 1070 struct vnode *vp; 1071 1072 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 1073 1074 if (mp->mnt_tmpfreevnodelistsize == 0) 1075 return; 1076 1077 TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) { 1078 VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp, 1079 ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist")); 1080 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 1081 } 1082 mtx_lock(&vnode_free_list_mtx); 1083 TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist); 1084 freevnodes += mp->mnt_tmpfreevnodelistsize; 1085 mtx_unlock(&vnode_free_list_mtx); 1086 mp->mnt_tmpfreevnodelistsize = 0; 1087 } 1088 1089 static void 1090 vnlru_return_batch(struct mount *mp) 1091 { 1092 1093 mtx_lock(&mp->mnt_listmtx); 1094 vnlru_return_batch_locked(mp); 1095 mtx_unlock(&mp->mnt_listmtx); 1096 } 1097 1098 static void 1099 vnlru_return_batches(struct vfsops *mnt_op) 1100 { 1101 struct mount *mp, *nmp; 1102 bool need_unbusy; 1103 1104 mtx_lock(&mountlist_mtx); 1105 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1106 need_unbusy = false; 1107 if (mnt_op != NULL && mp->mnt_op != mnt_op) 1108 goto next; 1109 if (mp->mnt_tmpfreevnodelistsize == 0) 1110 goto next; 1111 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) { 1112 vnlru_return_batch(mp); 1113 need_unbusy = true; 1114 mtx_lock(&mountlist_mtx); 1115 } 1116 next: 1117 nmp = TAILQ_NEXT(mp, mnt_list); 1118 if (need_unbusy) 1119 vfs_unbusy(mp); 1120 } 1121 mtx_unlock(&mountlist_mtx); 1122 } 1123 1124 /* 1125 * Attempt to recycle vnodes in a context that is always safe to block. 1126 * Calling vlrurecycle() from the bowels of filesystem code has some 1127 * interesting deadlock problems. 1128 */ 1129 static struct proc *vnlruproc; 1130 static int vnlruproc_sig; 1131 1132 static void 1133 vnlru_proc(void) 1134 { 1135 struct mount *mp, *nmp; 1136 unsigned long onumvnodes; 1137 int done, force, reclaim_nc_src, trigger, usevnodes; 1138 1139 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1140 SHUTDOWN_PRI_FIRST); 1141 1142 force = 0; 1143 for (;;) { 1144 kproc_suspend_check(vnlruproc); 1145 mtx_lock(&vnode_free_list_mtx); 1146 /* 1147 * If numvnodes is too large (due to desiredvnodes being 1148 * adjusted using its sysctl, or emergency growth), first 1149 * try to reduce it by discarding from the free list. 1150 */ 1151 if (numvnodes > desiredvnodes) 1152 vnlru_free_locked(numvnodes - desiredvnodes, NULL); 1153 /* 1154 * Sleep if the vnode cache is in a good state. This is 1155 * when it is not over-full and has space for about a 4% 1156 * or 9% expansion (by growing its size or inexcessively 1157 * reducing its free list). Otherwise, try to reclaim 1158 * space for a 10% expansion. 1159 */ 1160 if (vstir && force == 0) { 1161 force = 1; 1162 vstir = 0; 1163 } 1164 if (vspace() >= vlowat && force == 0) { 1165 vnlruproc_sig = 0; 1166 wakeup(&vnlruproc_sig); 1167 msleep(vnlruproc, &vnode_free_list_mtx, 1168 PVFS|PDROP, "vlruwt", hz); 1169 continue; 1170 } 1171 mtx_unlock(&vnode_free_list_mtx); 1172 done = 0; 1173 onumvnodes = numvnodes; 1174 /* 1175 * Calculate parameters for recycling. These are the same 1176 * throughout the loop to give some semblance of fairness. 1177 * The trigger point is to avoid recycling vnodes with lots 1178 * of resident pages. We aren't trying to free memory; we 1179 * are trying to recycle or at least free vnodes. 1180 */ 1181 if (numvnodes <= desiredvnodes) 1182 usevnodes = numvnodes - freevnodes; 1183 else 1184 usevnodes = numvnodes; 1185 if (usevnodes <= 0) 1186 usevnodes = 1; 1187 /* 1188 * The trigger value is is chosen to give a conservatively 1189 * large value to ensure that it alone doesn't prevent 1190 * making progress. The value can easily be so large that 1191 * it is effectively infinite in some congested and 1192 * misconfigured cases, and this is necessary. Normally 1193 * it is about 8 to 100 (pages), which is quite large. 1194 */ 1195 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1196 if (force < 2) 1197 trigger = vsmalltrigger; 1198 reclaim_nc_src = force >= 3; 1199 mtx_lock(&mountlist_mtx); 1200 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1201 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { 1202 nmp = TAILQ_NEXT(mp, mnt_list); 1203 continue; 1204 } 1205 done += vlrureclaim(mp, reclaim_nc_src, trigger); 1206 mtx_lock(&mountlist_mtx); 1207 nmp = TAILQ_NEXT(mp, mnt_list); 1208 vfs_unbusy(mp); 1209 } 1210 mtx_unlock(&mountlist_mtx); 1211 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1212 uma_reclaim(); 1213 if (done == 0) { 1214 if (force == 0 || force == 1) { 1215 force = 2; 1216 continue; 1217 } 1218 if (force == 2) { 1219 force = 3; 1220 continue; 1221 } 1222 force = 0; 1223 vnlru_nowhere++; 1224 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1225 } else 1226 kern_yield(PRI_USER); 1227 /* 1228 * After becoming active to expand above low water, keep 1229 * active until above high water. 1230 */ 1231 force = vspace() < vhiwat; 1232 } 1233 } 1234 1235 static struct kproc_desc vnlru_kp = { 1236 "vnlru", 1237 vnlru_proc, 1238 &vnlruproc 1239 }; 1240 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1241 &vnlru_kp); 1242 1243 /* 1244 * Routines having to do with the management of the vnode table. 1245 */ 1246 1247 /* 1248 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1249 * before we actually vgone(). This function must be called with the vnode 1250 * held to prevent the vnode from being returned to the free list midway 1251 * through vgone(). 1252 */ 1253 static int 1254 vtryrecycle(struct vnode *vp) 1255 { 1256 struct mount *vnmp; 1257 1258 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1259 VNASSERT(vp->v_holdcnt, vp, 1260 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1261 /* 1262 * This vnode may found and locked via some other list, if so we 1263 * can't recycle it yet. 1264 */ 1265 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1266 CTR2(KTR_VFS, 1267 "%s: impossible to recycle, vp %p lock is already held", 1268 __func__, vp); 1269 return (EWOULDBLOCK); 1270 } 1271 /* 1272 * Don't recycle if its filesystem is being suspended. 1273 */ 1274 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1275 VOP_UNLOCK(vp, 0); 1276 CTR2(KTR_VFS, 1277 "%s: impossible to recycle, cannot start the write for %p", 1278 __func__, vp); 1279 return (EBUSY); 1280 } 1281 /* 1282 * If we got this far, we need to acquire the interlock and see if 1283 * anyone picked up this vnode from another list. If not, we will 1284 * mark it with DOOMED via vgonel() so that anyone who does find it 1285 * will skip over it. 1286 */ 1287 VI_LOCK(vp); 1288 if (vp->v_usecount) { 1289 VOP_UNLOCK(vp, LK_INTERLOCK); 1290 vn_finished_write(vnmp); 1291 CTR2(KTR_VFS, 1292 "%s: impossible to recycle, %p is already referenced", 1293 __func__, vp); 1294 return (EBUSY); 1295 } 1296 if ((vp->v_iflag & VI_DOOMED) == 0) { 1297 counter_u64_add(recycles_count, 1); 1298 vgonel(vp); 1299 } 1300 VOP_UNLOCK(vp, LK_INTERLOCK); 1301 vn_finished_write(vnmp); 1302 return (0); 1303 } 1304 1305 static void 1306 vcheckspace(void) 1307 { 1308 1309 if (vspace() < vlowat && vnlruproc_sig == 0) { 1310 vnlruproc_sig = 1; 1311 wakeup(vnlruproc); 1312 } 1313 } 1314 1315 /* 1316 * Wait if necessary for space for a new vnode. 1317 */ 1318 static int 1319 getnewvnode_wait(int suspended) 1320 { 1321 1322 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1323 if (numvnodes >= desiredvnodes) { 1324 if (suspended) { 1325 /* 1326 * The file system is being suspended. We cannot 1327 * risk a deadlock here, so allow allocation of 1328 * another vnode even if this would give too many. 1329 */ 1330 return (0); 1331 } 1332 if (vnlruproc_sig == 0) { 1333 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 1334 wakeup(vnlruproc); 1335 } 1336 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 1337 "vlruwk", hz); 1338 } 1339 /* Post-adjust like the pre-adjust in getnewvnode(). */ 1340 if (numvnodes + 1 > desiredvnodes && freevnodes > 1) 1341 vnlru_free_locked(1, NULL); 1342 return (numvnodes >= desiredvnodes ? ENFILE : 0); 1343 } 1344 1345 /* 1346 * This hack is fragile, and probably not needed any more now that the 1347 * watermark handling works. 1348 */ 1349 void 1350 getnewvnode_reserve(u_int count) 1351 { 1352 struct thread *td; 1353 1354 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */ 1355 /* XXX no longer so quick, but this part is not racy. */ 1356 mtx_lock(&vnode_free_list_mtx); 1357 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes) 1358 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes, 1359 freevnodes - wantfreevnodes), NULL); 1360 mtx_unlock(&vnode_free_list_mtx); 1361 1362 td = curthread; 1363 /* First try to be quick and racy. */ 1364 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) { 1365 td->td_vp_reserv += count; 1366 vcheckspace(); /* XXX no longer so quick, but more racy */ 1367 return; 1368 } else 1369 atomic_subtract_long(&numvnodes, count); 1370 1371 mtx_lock(&vnode_free_list_mtx); 1372 while (count > 0) { 1373 if (getnewvnode_wait(0) == 0) { 1374 count--; 1375 td->td_vp_reserv++; 1376 atomic_add_long(&numvnodes, 1); 1377 } 1378 } 1379 vcheckspace(); 1380 mtx_unlock(&vnode_free_list_mtx); 1381 } 1382 1383 /* 1384 * This hack is fragile, especially if desiredvnodes or wantvnodes are 1385 * misconfgured or changed significantly. Reducing desiredvnodes below 1386 * the reserved amount should cause bizarre behaviour like reducing it 1387 * below the number of active vnodes -- the system will try to reduce 1388 * numvnodes to match, but should fail, so the subtraction below should 1389 * not overflow. 1390 */ 1391 void 1392 getnewvnode_drop_reserve(void) 1393 { 1394 struct thread *td; 1395 1396 td = curthread; 1397 atomic_subtract_long(&numvnodes, td->td_vp_reserv); 1398 td->td_vp_reserv = 0; 1399 } 1400 1401 /* 1402 * Return the next vnode from the free list. 1403 */ 1404 int 1405 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1406 struct vnode **vpp) 1407 { 1408 struct vnode *vp; 1409 struct thread *td; 1410 struct lock_object *lo; 1411 static int cyclecount; 1412 int error; 1413 1414 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1415 vp = NULL; 1416 td = curthread; 1417 if (td->td_vp_reserv > 0) { 1418 td->td_vp_reserv -= 1; 1419 goto alloc; 1420 } 1421 mtx_lock(&vnode_free_list_mtx); 1422 if (numvnodes < desiredvnodes) 1423 cyclecount = 0; 1424 else if (cyclecount++ >= freevnodes) { 1425 cyclecount = 0; 1426 vstir = 1; 1427 } 1428 /* 1429 * Grow the vnode cache if it will not be above its target max 1430 * after growing. Otherwise, if the free list is nonempty, try 1431 * to reclaim 1 item from it before growing the cache (possibly 1432 * above its target max if the reclamation failed or is delayed). 1433 * Otherwise, wait for some space. In all cases, schedule 1434 * vnlru_proc() if we are getting short of space. The watermarks 1435 * should be chosen so that we never wait or even reclaim from 1436 * the free list to below its target minimum. 1437 */ 1438 if (numvnodes + 1 <= desiredvnodes) 1439 ; 1440 else if (freevnodes > 0) 1441 vnlru_free_locked(1, NULL); 1442 else { 1443 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag & 1444 MNTK_SUSPEND)); 1445 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 1446 if (error != 0) { 1447 mtx_unlock(&vnode_free_list_mtx); 1448 return (error); 1449 } 1450 #endif 1451 } 1452 vcheckspace(); 1453 atomic_add_long(&numvnodes, 1); 1454 mtx_unlock(&vnode_free_list_mtx); 1455 alloc: 1456 counter_u64_add(vnodes_created, 1); 1457 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 1458 /* 1459 * Locks are given the generic name "vnode" when created. 1460 * Follow the historic practice of using the filesystem 1461 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1462 * 1463 * Locks live in a witness group keyed on their name. Thus, 1464 * when a lock is renamed, it must also move from the witness 1465 * group of its old name to the witness group of its new name. 1466 * 1467 * The change only needs to be made when the vnode moves 1468 * from one filesystem type to another. We ensure that each 1469 * filesystem use a single static name pointer for its tag so 1470 * that we can compare pointers rather than doing a strcmp(). 1471 */ 1472 lo = &vp->v_vnlock->lock_object; 1473 if (lo->lo_name != tag) { 1474 lo->lo_name = tag; 1475 WITNESS_DESTROY(lo); 1476 WITNESS_INIT(lo, tag); 1477 } 1478 /* 1479 * By default, don't allow shared locks unless filesystems opt-in. 1480 */ 1481 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1482 /* 1483 * Finalize various vnode identity bits. 1484 */ 1485 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1486 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1487 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1488 vp->v_type = VNON; 1489 vp->v_tag = tag; 1490 vp->v_op = vops; 1491 v_init_counters(vp); 1492 vp->v_bufobj.bo_ops = &buf_ops_bio; 1493 #ifdef DIAGNOSTIC 1494 if (mp == NULL && vops != &dead_vnodeops) 1495 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1496 #endif 1497 #ifdef MAC 1498 mac_vnode_init(vp); 1499 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1500 mac_vnode_associate_singlelabel(mp, vp); 1501 #endif 1502 if (mp != NULL) { 1503 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1504 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1505 vp->v_vflag |= VV_NOKNOTE; 1506 } 1507 1508 /* 1509 * For the filesystems which do not use vfs_hash_insert(), 1510 * still initialize v_hash to have vfs_hash_index() useful. 1511 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1512 * its own hashing. 1513 */ 1514 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1515 1516 *vpp = vp; 1517 return (0); 1518 } 1519 1520 /* 1521 * Delete from old mount point vnode list, if on one. 1522 */ 1523 static void 1524 delmntque(struct vnode *vp) 1525 { 1526 struct mount *mp; 1527 int active; 1528 1529 mp = vp->v_mount; 1530 if (mp == NULL) 1531 return; 1532 MNT_ILOCK(mp); 1533 VI_LOCK(vp); 1534 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize, 1535 ("Active vnode list size %d > Vnode list size %d", 1536 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize)); 1537 active = vp->v_iflag & VI_ACTIVE; 1538 vp->v_iflag &= ~VI_ACTIVE; 1539 if (active) { 1540 mtx_lock(&mp->mnt_listmtx); 1541 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); 1542 mp->mnt_activevnodelistsize--; 1543 mtx_unlock(&mp->mnt_listmtx); 1544 } 1545 vp->v_mount = NULL; 1546 VI_UNLOCK(vp); 1547 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1548 ("bad mount point vnode list size")); 1549 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1550 mp->mnt_nvnodelistsize--; 1551 MNT_REL(mp); 1552 MNT_IUNLOCK(mp); 1553 } 1554 1555 static void 1556 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1557 { 1558 1559 vp->v_data = NULL; 1560 vp->v_op = &dead_vnodeops; 1561 vgone(vp); 1562 vput(vp); 1563 } 1564 1565 /* 1566 * Insert into list of vnodes for the new mount point, if available. 1567 */ 1568 int 1569 insmntque1(struct vnode *vp, struct mount *mp, 1570 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1571 { 1572 1573 KASSERT(vp->v_mount == NULL, 1574 ("insmntque: vnode already on per mount vnode list")); 1575 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1576 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1577 1578 /* 1579 * We acquire the vnode interlock early to ensure that the 1580 * vnode cannot be recycled by another process releasing a 1581 * holdcnt on it before we get it on both the vnode list 1582 * and the active vnode list. The mount mutex protects only 1583 * manipulation of the vnode list and the vnode freelist 1584 * mutex protects only manipulation of the active vnode list. 1585 * Hence the need to hold the vnode interlock throughout. 1586 */ 1587 MNT_ILOCK(mp); 1588 VI_LOCK(vp); 1589 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1590 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1591 mp->mnt_nvnodelistsize == 0)) && 1592 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1593 VI_UNLOCK(vp); 1594 MNT_IUNLOCK(mp); 1595 if (dtr != NULL) 1596 dtr(vp, dtr_arg); 1597 return (EBUSY); 1598 } 1599 vp->v_mount = mp; 1600 MNT_REF(mp); 1601 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1602 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1603 ("neg mount point vnode list size")); 1604 mp->mnt_nvnodelistsize++; 1605 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1606 ("Activating already active vnode")); 1607 vp->v_iflag |= VI_ACTIVE; 1608 mtx_lock(&mp->mnt_listmtx); 1609 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 1610 mp->mnt_activevnodelistsize++; 1611 mtx_unlock(&mp->mnt_listmtx); 1612 VI_UNLOCK(vp); 1613 MNT_IUNLOCK(mp); 1614 return (0); 1615 } 1616 1617 int 1618 insmntque(struct vnode *vp, struct mount *mp) 1619 { 1620 1621 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1622 } 1623 1624 /* 1625 * Flush out and invalidate all buffers associated with a bufobj 1626 * Called with the underlying object locked. 1627 */ 1628 int 1629 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1630 { 1631 int error; 1632 1633 BO_LOCK(bo); 1634 if (flags & V_SAVE) { 1635 error = bufobj_wwait(bo, slpflag, slptimeo); 1636 if (error) { 1637 BO_UNLOCK(bo); 1638 return (error); 1639 } 1640 if (bo->bo_dirty.bv_cnt > 0) { 1641 BO_UNLOCK(bo); 1642 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1643 return (error); 1644 /* 1645 * XXX We could save a lock/unlock if this was only 1646 * enabled under INVARIANTS 1647 */ 1648 BO_LOCK(bo); 1649 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1650 panic("vinvalbuf: dirty bufs"); 1651 } 1652 } 1653 /* 1654 * If you alter this loop please notice that interlock is dropped and 1655 * reacquired in flushbuflist. Special care is needed to ensure that 1656 * no race conditions occur from this. 1657 */ 1658 do { 1659 error = flushbuflist(&bo->bo_clean, 1660 flags, bo, slpflag, slptimeo); 1661 if (error == 0 && !(flags & V_CLEANONLY)) 1662 error = flushbuflist(&bo->bo_dirty, 1663 flags, bo, slpflag, slptimeo); 1664 if (error != 0 && error != EAGAIN) { 1665 BO_UNLOCK(bo); 1666 return (error); 1667 } 1668 } while (error != 0); 1669 1670 /* 1671 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1672 * have write I/O in-progress but if there is a VM object then the 1673 * VM object can also have read-I/O in-progress. 1674 */ 1675 do { 1676 bufobj_wwait(bo, 0, 0); 1677 if ((flags & V_VMIO) == 0) { 1678 BO_UNLOCK(bo); 1679 if (bo->bo_object != NULL) { 1680 VM_OBJECT_WLOCK(bo->bo_object); 1681 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1682 VM_OBJECT_WUNLOCK(bo->bo_object); 1683 } 1684 BO_LOCK(bo); 1685 } 1686 } while (bo->bo_numoutput > 0); 1687 BO_UNLOCK(bo); 1688 1689 /* 1690 * Destroy the copy in the VM cache, too. 1691 */ 1692 if (bo->bo_object != NULL && 1693 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1694 VM_OBJECT_WLOCK(bo->bo_object); 1695 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1696 OBJPR_CLEANONLY : 0); 1697 VM_OBJECT_WUNLOCK(bo->bo_object); 1698 } 1699 1700 #ifdef INVARIANTS 1701 BO_LOCK(bo); 1702 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1703 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1704 bo->bo_clean.bv_cnt > 0)) 1705 panic("vinvalbuf: flush failed"); 1706 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1707 bo->bo_dirty.bv_cnt > 0) 1708 panic("vinvalbuf: flush dirty failed"); 1709 BO_UNLOCK(bo); 1710 #endif 1711 return (0); 1712 } 1713 1714 /* 1715 * Flush out and invalidate all buffers associated with a vnode. 1716 * Called with the underlying object locked. 1717 */ 1718 int 1719 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1720 { 1721 1722 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1723 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1724 if (vp->v_object != NULL && vp->v_object->handle != vp) 1725 return (0); 1726 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1727 } 1728 1729 /* 1730 * Flush out buffers on the specified list. 1731 * 1732 */ 1733 static int 1734 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1735 int slptimeo) 1736 { 1737 struct buf *bp, *nbp; 1738 int retval, error; 1739 daddr_t lblkno; 1740 b_xflags_t xflags; 1741 1742 ASSERT_BO_WLOCKED(bo); 1743 1744 retval = 0; 1745 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1746 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1747 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1748 continue; 1749 } 1750 if (nbp != NULL) { 1751 lblkno = nbp->b_lblkno; 1752 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1753 } 1754 retval = EAGAIN; 1755 error = BUF_TIMELOCK(bp, 1756 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1757 "flushbuf", slpflag, slptimeo); 1758 if (error) { 1759 BO_LOCK(bo); 1760 return (error != ENOLCK ? error : EAGAIN); 1761 } 1762 KASSERT(bp->b_bufobj == bo, 1763 ("bp %p wrong b_bufobj %p should be %p", 1764 bp, bp->b_bufobj, bo)); 1765 /* 1766 * XXX Since there are no node locks for NFS, I 1767 * believe there is a slight chance that a delayed 1768 * write will occur while sleeping just above, so 1769 * check for it. 1770 */ 1771 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1772 (flags & V_SAVE)) { 1773 bremfree(bp); 1774 bp->b_flags |= B_ASYNC; 1775 bwrite(bp); 1776 BO_LOCK(bo); 1777 return (EAGAIN); /* XXX: why not loop ? */ 1778 } 1779 bremfree(bp); 1780 bp->b_flags |= (B_INVAL | B_RELBUF); 1781 bp->b_flags &= ~B_ASYNC; 1782 brelse(bp); 1783 BO_LOCK(bo); 1784 if (nbp == NULL) 1785 break; 1786 nbp = gbincore(bo, lblkno); 1787 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1788 != xflags) 1789 break; /* nbp invalid */ 1790 } 1791 return (retval); 1792 } 1793 1794 int 1795 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 1796 { 1797 struct buf *bp; 1798 int error; 1799 daddr_t lblkno; 1800 1801 ASSERT_BO_LOCKED(bo); 1802 1803 for (lblkno = startn;;) { 1804 again: 1805 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 1806 if (bp == NULL || bp->b_lblkno >= endn || 1807 bp->b_lblkno < startn) 1808 break; 1809 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 1810 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 1811 if (error != 0) { 1812 BO_RLOCK(bo); 1813 if (error == ENOLCK) 1814 goto again; 1815 return (error); 1816 } 1817 KASSERT(bp->b_bufobj == bo, 1818 ("bp %p wrong b_bufobj %p should be %p", 1819 bp, bp->b_bufobj, bo)); 1820 lblkno = bp->b_lblkno + 1; 1821 if ((bp->b_flags & B_MANAGED) == 0) 1822 bremfree(bp); 1823 bp->b_flags |= B_RELBUF; 1824 /* 1825 * In the VMIO case, use the B_NOREUSE flag to hint that the 1826 * pages backing each buffer in the range are unlikely to be 1827 * reused. Dirty buffers will have the hint applied once 1828 * they've been written. 1829 */ 1830 if (bp->b_vp->v_object != NULL) 1831 bp->b_flags |= B_NOREUSE; 1832 brelse(bp); 1833 BO_RLOCK(bo); 1834 } 1835 return (0); 1836 } 1837 1838 /* 1839 * Truncate a file's buffer and pages to a specified length. This 1840 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1841 * sync activity. 1842 */ 1843 int 1844 vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize) 1845 { 1846 struct buf *bp, *nbp; 1847 int anyfreed; 1848 int trunclbn; 1849 struct bufobj *bo; 1850 1851 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__, 1852 vp, cred, blksize, (uintmax_t)length); 1853 1854 /* 1855 * Round up to the *next* lbn. 1856 */ 1857 trunclbn = howmany(length, blksize); 1858 1859 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1860 restart: 1861 bo = &vp->v_bufobj; 1862 BO_LOCK(bo); 1863 anyfreed = 1; 1864 for (;anyfreed;) { 1865 anyfreed = 0; 1866 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1867 if (bp->b_lblkno < trunclbn) 1868 continue; 1869 if (BUF_LOCK(bp, 1870 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1871 BO_LOCKPTR(bo)) == ENOLCK) 1872 goto restart; 1873 1874 bremfree(bp); 1875 bp->b_flags |= (B_INVAL | B_RELBUF); 1876 bp->b_flags &= ~B_ASYNC; 1877 brelse(bp); 1878 anyfreed = 1; 1879 1880 BO_LOCK(bo); 1881 if (nbp != NULL && 1882 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1883 (nbp->b_vp != vp) || 1884 (nbp->b_flags & B_DELWRI))) { 1885 BO_UNLOCK(bo); 1886 goto restart; 1887 } 1888 } 1889 1890 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1891 if (bp->b_lblkno < trunclbn) 1892 continue; 1893 if (BUF_LOCK(bp, 1894 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1895 BO_LOCKPTR(bo)) == ENOLCK) 1896 goto restart; 1897 bremfree(bp); 1898 bp->b_flags |= (B_INVAL | B_RELBUF); 1899 bp->b_flags &= ~B_ASYNC; 1900 brelse(bp); 1901 anyfreed = 1; 1902 1903 BO_LOCK(bo); 1904 if (nbp != NULL && 1905 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1906 (nbp->b_vp != vp) || 1907 (nbp->b_flags & B_DELWRI) == 0)) { 1908 BO_UNLOCK(bo); 1909 goto restart; 1910 } 1911 } 1912 } 1913 1914 if (length > 0) { 1915 restartsync: 1916 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1917 if (bp->b_lblkno > 0) 1918 continue; 1919 /* 1920 * Since we hold the vnode lock this should only 1921 * fail if we're racing with the buf daemon. 1922 */ 1923 if (BUF_LOCK(bp, 1924 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1925 BO_LOCKPTR(bo)) == ENOLCK) { 1926 goto restart; 1927 } 1928 VNASSERT((bp->b_flags & B_DELWRI), vp, 1929 ("buf(%p) on dirty queue without DELWRI", bp)); 1930 1931 bremfree(bp); 1932 bawrite(bp); 1933 BO_LOCK(bo); 1934 goto restartsync; 1935 } 1936 } 1937 1938 bufobj_wwait(bo, 0, 0); 1939 BO_UNLOCK(bo); 1940 vnode_pager_setsize(vp, length); 1941 1942 return (0); 1943 } 1944 1945 static void 1946 buf_vlist_remove(struct buf *bp) 1947 { 1948 struct bufv *bv; 1949 1950 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1951 ASSERT_BO_WLOCKED(bp->b_bufobj); 1952 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1953 (BX_VNDIRTY|BX_VNCLEAN), 1954 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1955 if (bp->b_xflags & BX_VNDIRTY) 1956 bv = &bp->b_bufobj->bo_dirty; 1957 else 1958 bv = &bp->b_bufobj->bo_clean; 1959 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 1960 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1961 bv->bv_cnt--; 1962 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1963 } 1964 1965 /* 1966 * Add the buffer to the sorted clean or dirty block list. 1967 * 1968 * NOTE: xflags is passed as a constant, optimizing this inline function! 1969 */ 1970 static void 1971 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1972 { 1973 struct bufv *bv; 1974 struct buf *n; 1975 int error; 1976 1977 ASSERT_BO_WLOCKED(bo); 1978 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 1979 ("dead bo %p", bo)); 1980 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1981 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1982 bp->b_xflags |= xflags; 1983 if (xflags & BX_VNDIRTY) 1984 bv = &bo->bo_dirty; 1985 else 1986 bv = &bo->bo_clean; 1987 1988 /* 1989 * Keep the list ordered. Optimize empty list insertion. Assume 1990 * we tend to grow at the tail so lookup_le should usually be cheaper 1991 * than _ge. 1992 */ 1993 if (bv->bv_cnt == 0 || 1994 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 1995 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1996 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 1997 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 1998 else 1999 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 2000 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2001 if (error) 2002 panic("buf_vlist_add: Preallocated nodes insufficient."); 2003 bv->bv_cnt++; 2004 } 2005 2006 /* 2007 * Look up a buffer using the buffer tries. 2008 */ 2009 struct buf * 2010 gbincore(struct bufobj *bo, daddr_t lblkno) 2011 { 2012 struct buf *bp; 2013 2014 ASSERT_BO_LOCKED(bo); 2015 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2016 if (bp != NULL) 2017 return (bp); 2018 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2019 } 2020 2021 /* 2022 * Associate a buffer with a vnode. 2023 */ 2024 void 2025 bgetvp(struct vnode *vp, struct buf *bp) 2026 { 2027 struct bufobj *bo; 2028 2029 bo = &vp->v_bufobj; 2030 ASSERT_BO_WLOCKED(bo); 2031 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2032 2033 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2034 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2035 ("bgetvp: bp already attached! %p", bp)); 2036 2037 vhold(vp); 2038 bp->b_vp = vp; 2039 bp->b_bufobj = bo; 2040 /* 2041 * Insert onto list for new vnode. 2042 */ 2043 buf_vlist_add(bp, bo, BX_VNCLEAN); 2044 } 2045 2046 /* 2047 * Disassociate a buffer from a vnode. 2048 */ 2049 void 2050 brelvp(struct buf *bp) 2051 { 2052 struct bufobj *bo; 2053 struct vnode *vp; 2054 2055 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2056 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2057 2058 /* 2059 * Delete from old vnode list, if on one. 2060 */ 2061 vp = bp->b_vp; /* XXX */ 2062 bo = bp->b_bufobj; 2063 BO_LOCK(bo); 2064 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2065 buf_vlist_remove(bp); 2066 else 2067 panic("brelvp: Buffer %p not on queue.", bp); 2068 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2069 bo->bo_flag &= ~BO_ONWORKLST; 2070 mtx_lock(&sync_mtx); 2071 LIST_REMOVE(bo, bo_synclist); 2072 syncer_worklist_len--; 2073 mtx_unlock(&sync_mtx); 2074 } 2075 bp->b_vp = NULL; 2076 bp->b_bufobj = NULL; 2077 BO_UNLOCK(bo); 2078 vdrop(vp); 2079 } 2080 2081 /* 2082 * Add an item to the syncer work queue. 2083 */ 2084 static void 2085 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2086 { 2087 int slot; 2088 2089 ASSERT_BO_WLOCKED(bo); 2090 2091 mtx_lock(&sync_mtx); 2092 if (bo->bo_flag & BO_ONWORKLST) 2093 LIST_REMOVE(bo, bo_synclist); 2094 else { 2095 bo->bo_flag |= BO_ONWORKLST; 2096 syncer_worklist_len++; 2097 } 2098 2099 if (delay > syncer_maxdelay - 2) 2100 delay = syncer_maxdelay - 2; 2101 slot = (syncer_delayno + delay) & syncer_mask; 2102 2103 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2104 mtx_unlock(&sync_mtx); 2105 } 2106 2107 static int 2108 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2109 { 2110 int error, len; 2111 2112 mtx_lock(&sync_mtx); 2113 len = syncer_worklist_len - sync_vnode_count; 2114 mtx_unlock(&sync_mtx); 2115 error = SYSCTL_OUT(req, &len, sizeof(len)); 2116 return (error); 2117 } 2118 2119 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 2120 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2121 2122 static struct proc *updateproc; 2123 static void sched_sync(void); 2124 static struct kproc_desc up_kp = { 2125 "syncer", 2126 sched_sync, 2127 &updateproc 2128 }; 2129 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2130 2131 static int 2132 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2133 { 2134 struct vnode *vp; 2135 struct mount *mp; 2136 2137 *bo = LIST_FIRST(slp); 2138 if (*bo == NULL) 2139 return (0); 2140 vp = bo2vnode(*bo); 2141 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2142 return (1); 2143 /* 2144 * We use vhold in case the vnode does not 2145 * successfully sync. vhold prevents the vnode from 2146 * going away when we unlock the sync_mtx so that 2147 * we can acquire the vnode interlock. 2148 */ 2149 vholdl(vp); 2150 mtx_unlock(&sync_mtx); 2151 VI_UNLOCK(vp); 2152 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2153 vdrop(vp); 2154 mtx_lock(&sync_mtx); 2155 return (*bo == LIST_FIRST(slp)); 2156 } 2157 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2158 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2159 VOP_UNLOCK(vp, 0); 2160 vn_finished_write(mp); 2161 BO_LOCK(*bo); 2162 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2163 /* 2164 * Put us back on the worklist. The worklist 2165 * routine will remove us from our current 2166 * position and then add us back in at a later 2167 * position. 2168 */ 2169 vn_syncer_add_to_worklist(*bo, syncdelay); 2170 } 2171 BO_UNLOCK(*bo); 2172 vdrop(vp); 2173 mtx_lock(&sync_mtx); 2174 return (0); 2175 } 2176 2177 static int first_printf = 1; 2178 2179 /* 2180 * System filesystem synchronizer daemon. 2181 */ 2182 static void 2183 sched_sync(void) 2184 { 2185 struct synclist *next, *slp; 2186 struct bufobj *bo; 2187 long starttime; 2188 struct thread *td = curthread; 2189 int last_work_seen; 2190 int net_worklist_len; 2191 int syncer_final_iter; 2192 int error; 2193 2194 last_work_seen = 0; 2195 syncer_final_iter = 0; 2196 syncer_state = SYNCER_RUNNING; 2197 starttime = time_uptime; 2198 td->td_pflags |= TDP_NORUNNINGBUF; 2199 2200 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2201 SHUTDOWN_PRI_LAST); 2202 2203 mtx_lock(&sync_mtx); 2204 for (;;) { 2205 if (syncer_state == SYNCER_FINAL_DELAY && 2206 syncer_final_iter == 0) { 2207 mtx_unlock(&sync_mtx); 2208 kproc_suspend_check(td->td_proc); 2209 mtx_lock(&sync_mtx); 2210 } 2211 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2212 if (syncer_state != SYNCER_RUNNING && 2213 starttime != time_uptime) { 2214 if (first_printf) { 2215 printf("\nSyncing disks, vnodes remaining... "); 2216 first_printf = 0; 2217 } 2218 printf("%d ", net_worklist_len); 2219 } 2220 starttime = time_uptime; 2221 2222 /* 2223 * Push files whose dirty time has expired. Be careful 2224 * of interrupt race on slp queue. 2225 * 2226 * Skip over empty worklist slots when shutting down. 2227 */ 2228 do { 2229 slp = &syncer_workitem_pending[syncer_delayno]; 2230 syncer_delayno += 1; 2231 if (syncer_delayno == syncer_maxdelay) 2232 syncer_delayno = 0; 2233 next = &syncer_workitem_pending[syncer_delayno]; 2234 /* 2235 * If the worklist has wrapped since the 2236 * it was emptied of all but syncer vnodes, 2237 * switch to the FINAL_DELAY state and run 2238 * for one more second. 2239 */ 2240 if (syncer_state == SYNCER_SHUTTING_DOWN && 2241 net_worklist_len == 0 && 2242 last_work_seen == syncer_delayno) { 2243 syncer_state = SYNCER_FINAL_DELAY; 2244 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2245 } 2246 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2247 syncer_worklist_len > 0); 2248 2249 /* 2250 * Keep track of the last time there was anything 2251 * on the worklist other than syncer vnodes. 2252 * Return to the SHUTTING_DOWN state if any 2253 * new work appears. 2254 */ 2255 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2256 last_work_seen = syncer_delayno; 2257 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2258 syncer_state = SYNCER_SHUTTING_DOWN; 2259 while (!LIST_EMPTY(slp)) { 2260 error = sync_vnode(slp, &bo, td); 2261 if (error == 1) { 2262 LIST_REMOVE(bo, bo_synclist); 2263 LIST_INSERT_HEAD(next, bo, bo_synclist); 2264 continue; 2265 } 2266 2267 if (first_printf == 0) { 2268 /* 2269 * Drop the sync mutex, because some watchdog 2270 * drivers need to sleep while patting 2271 */ 2272 mtx_unlock(&sync_mtx); 2273 wdog_kern_pat(WD_LASTVAL); 2274 mtx_lock(&sync_mtx); 2275 } 2276 2277 } 2278 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2279 syncer_final_iter--; 2280 /* 2281 * The variable rushjob allows the kernel to speed up the 2282 * processing of the filesystem syncer process. A rushjob 2283 * value of N tells the filesystem syncer to process the next 2284 * N seconds worth of work on its queue ASAP. Currently rushjob 2285 * is used by the soft update code to speed up the filesystem 2286 * syncer process when the incore state is getting so far 2287 * ahead of the disk that the kernel memory pool is being 2288 * threatened with exhaustion. 2289 */ 2290 if (rushjob > 0) { 2291 rushjob -= 1; 2292 continue; 2293 } 2294 /* 2295 * Just sleep for a short period of time between 2296 * iterations when shutting down to allow some I/O 2297 * to happen. 2298 * 2299 * If it has taken us less than a second to process the 2300 * current work, then wait. Otherwise start right over 2301 * again. We can still lose time if any single round 2302 * takes more than two seconds, but it does not really 2303 * matter as we are just trying to generally pace the 2304 * filesystem activity. 2305 */ 2306 if (syncer_state != SYNCER_RUNNING || 2307 time_uptime == starttime) { 2308 thread_lock(td); 2309 sched_prio(td, PPAUSE); 2310 thread_unlock(td); 2311 } 2312 if (syncer_state != SYNCER_RUNNING) 2313 cv_timedwait(&sync_wakeup, &sync_mtx, 2314 hz / SYNCER_SHUTDOWN_SPEEDUP); 2315 else if (time_uptime == starttime) 2316 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2317 } 2318 } 2319 2320 /* 2321 * Request the syncer daemon to speed up its work. 2322 * We never push it to speed up more than half of its 2323 * normal turn time, otherwise it could take over the cpu. 2324 */ 2325 int 2326 speedup_syncer(void) 2327 { 2328 int ret = 0; 2329 2330 mtx_lock(&sync_mtx); 2331 if (rushjob < syncdelay / 2) { 2332 rushjob += 1; 2333 stat_rush_requests += 1; 2334 ret = 1; 2335 } 2336 mtx_unlock(&sync_mtx); 2337 cv_broadcast(&sync_wakeup); 2338 return (ret); 2339 } 2340 2341 /* 2342 * Tell the syncer to speed up its work and run though its work 2343 * list several times, then tell it to shut down. 2344 */ 2345 static void 2346 syncer_shutdown(void *arg, int howto) 2347 { 2348 2349 if (howto & RB_NOSYNC) 2350 return; 2351 mtx_lock(&sync_mtx); 2352 syncer_state = SYNCER_SHUTTING_DOWN; 2353 rushjob = 0; 2354 mtx_unlock(&sync_mtx); 2355 cv_broadcast(&sync_wakeup); 2356 kproc_shutdown(arg, howto); 2357 } 2358 2359 void 2360 syncer_suspend(void) 2361 { 2362 2363 syncer_shutdown(updateproc, 0); 2364 } 2365 2366 void 2367 syncer_resume(void) 2368 { 2369 2370 mtx_lock(&sync_mtx); 2371 first_printf = 1; 2372 syncer_state = SYNCER_RUNNING; 2373 mtx_unlock(&sync_mtx); 2374 cv_broadcast(&sync_wakeup); 2375 kproc_resume(updateproc); 2376 } 2377 2378 /* 2379 * Reassign a buffer from one vnode to another. 2380 * Used to assign file specific control information 2381 * (indirect blocks) to the vnode to which they belong. 2382 */ 2383 void 2384 reassignbuf(struct buf *bp) 2385 { 2386 struct vnode *vp; 2387 struct bufobj *bo; 2388 int delay; 2389 #ifdef INVARIANTS 2390 struct bufv *bv; 2391 #endif 2392 2393 vp = bp->b_vp; 2394 bo = bp->b_bufobj; 2395 ++reassignbufcalls; 2396 2397 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2398 bp, bp->b_vp, bp->b_flags); 2399 /* 2400 * B_PAGING flagged buffers cannot be reassigned because their vp 2401 * is not fully linked in. 2402 */ 2403 if (bp->b_flags & B_PAGING) 2404 panic("cannot reassign paging buffer"); 2405 2406 /* 2407 * Delete from old vnode list, if on one. 2408 */ 2409 BO_LOCK(bo); 2410 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2411 buf_vlist_remove(bp); 2412 else 2413 panic("reassignbuf: Buffer %p not on queue.", bp); 2414 /* 2415 * If dirty, put on list of dirty buffers; otherwise insert onto list 2416 * of clean buffers. 2417 */ 2418 if (bp->b_flags & B_DELWRI) { 2419 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2420 switch (vp->v_type) { 2421 case VDIR: 2422 delay = dirdelay; 2423 break; 2424 case VCHR: 2425 delay = metadelay; 2426 break; 2427 default: 2428 delay = filedelay; 2429 } 2430 vn_syncer_add_to_worklist(bo, delay); 2431 } 2432 buf_vlist_add(bp, bo, BX_VNDIRTY); 2433 } else { 2434 buf_vlist_add(bp, bo, BX_VNCLEAN); 2435 2436 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2437 mtx_lock(&sync_mtx); 2438 LIST_REMOVE(bo, bo_synclist); 2439 syncer_worklist_len--; 2440 mtx_unlock(&sync_mtx); 2441 bo->bo_flag &= ~BO_ONWORKLST; 2442 } 2443 } 2444 #ifdef INVARIANTS 2445 bv = &bo->bo_clean; 2446 bp = TAILQ_FIRST(&bv->bv_hd); 2447 KASSERT(bp == NULL || bp->b_bufobj == bo, 2448 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2449 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2450 KASSERT(bp == NULL || bp->b_bufobj == bo, 2451 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2452 bv = &bo->bo_dirty; 2453 bp = TAILQ_FIRST(&bv->bv_hd); 2454 KASSERT(bp == NULL || bp->b_bufobj == bo, 2455 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2456 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2457 KASSERT(bp == NULL || bp->b_bufobj == bo, 2458 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2459 #endif 2460 BO_UNLOCK(bo); 2461 } 2462 2463 /* 2464 * A temporary hack until refcount_* APIs are sorted out. 2465 */ 2466 static __inline int 2467 vfs_refcount_acquire_if_not_zero(volatile u_int *count) 2468 { 2469 u_int old; 2470 2471 old = *count; 2472 for (;;) { 2473 if (old == 0) 2474 return (0); 2475 if (atomic_fcmpset_int(count, &old, old + 1)) 2476 return (1); 2477 } 2478 } 2479 2480 static __inline int 2481 vfs_refcount_release_if_not_last(volatile u_int *count) 2482 { 2483 u_int old; 2484 2485 old = *count; 2486 for (;;) { 2487 if (old == 1) 2488 return (0); 2489 if (atomic_fcmpset_int(count, &old, old - 1)) 2490 return (1); 2491 } 2492 } 2493 2494 static void 2495 v_init_counters(struct vnode *vp) 2496 { 2497 2498 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2499 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2500 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2501 2502 refcount_init(&vp->v_holdcnt, 1); 2503 refcount_init(&vp->v_usecount, 1); 2504 } 2505 2506 static void 2507 v_incr_usecount_locked(struct vnode *vp) 2508 { 2509 2510 ASSERT_VI_LOCKED(vp, __func__); 2511 if ((vp->v_iflag & VI_OWEINACT) != 0) { 2512 VNASSERT(vp->v_usecount == 0, vp, 2513 ("vnode with usecount and VI_OWEINACT set")); 2514 vp->v_iflag &= ~VI_OWEINACT; 2515 } 2516 refcount_acquire(&vp->v_usecount); 2517 v_incr_devcount(vp); 2518 } 2519 2520 /* 2521 * Increment the use count on the vnode, taking care to reference 2522 * the driver's usecount if this is a chardev. 2523 */ 2524 static void 2525 v_incr_usecount(struct vnode *vp) 2526 { 2527 2528 ASSERT_VI_UNLOCKED(vp, __func__); 2529 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2530 2531 if (vp->v_type != VCHR && 2532 vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) { 2533 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2534 ("vnode with usecount and VI_OWEINACT set")); 2535 } else { 2536 VI_LOCK(vp); 2537 v_incr_usecount_locked(vp); 2538 VI_UNLOCK(vp); 2539 } 2540 } 2541 2542 /* 2543 * Increment si_usecount of the associated device, if any. 2544 */ 2545 static void 2546 v_incr_devcount(struct vnode *vp) 2547 { 2548 2549 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2550 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2551 dev_lock(); 2552 vp->v_rdev->si_usecount++; 2553 dev_unlock(); 2554 } 2555 } 2556 2557 /* 2558 * Decrement si_usecount of the associated device, if any. 2559 */ 2560 static void 2561 v_decr_devcount(struct vnode *vp) 2562 { 2563 2564 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2565 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2566 dev_lock(); 2567 vp->v_rdev->si_usecount--; 2568 dev_unlock(); 2569 } 2570 } 2571 2572 /* 2573 * Grab a particular vnode from the free list, increment its 2574 * reference count and lock it. VI_DOOMED is set if the vnode 2575 * is being destroyed. Only callers who specify LK_RETRY will 2576 * see doomed vnodes. If inactive processing was delayed in 2577 * vput try to do it here. 2578 * 2579 * Notes on lockless counter manipulation: 2580 * _vhold, vputx and other routines make various decisions based 2581 * on either holdcnt or usecount being 0. As long as either counter 2582 * is not transitioning 0->1 nor 1->0, the manipulation can be done 2583 * with atomic operations. Otherwise the interlock is taken covering 2584 * both the atomic and additional actions. 2585 */ 2586 int 2587 vget(struct vnode *vp, int flags, struct thread *td) 2588 { 2589 int error, oweinact; 2590 2591 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2592 ("vget: invalid lock operation")); 2593 2594 if ((flags & LK_INTERLOCK) != 0) 2595 ASSERT_VI_LOCKED(vp, __func__); 2596 else 2597 ASSERT_VI_UNLOCKED(vp, __func__); 2598 if ((flags & LK_VNHELD) != 0) 2599 VNASSERT((vp->v_holdcnt > 0), vp, 2600 ("vget: LK_VNHELD passed but vnode not held")); 2601 2602 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2603 2604 if ((flags & LK_VNHELD) == 0) 2605 _vhold(vp, (flags & LK_INTERLOCK) != 0); 2606 2607 if ((error = vn_lock(vp, flags)) != 0) { 2608 vdrop(vp); 2609 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2610 vp); 2611 return (error); 2612 } 2613 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2614 panic("vget: vn_lock failed to return ENOENT\n"); 2615 /* 2616 * We don't guarantee that any particular close will 2617 * trigger inactive processing so just make a best effort 2618 * here at preventing a reference to a removed file. If 2619 * we don't succeed no harm is done. 2620 * 2621 * Upgrade our holdcnt to a usecount. 2622 */ 2623 if (vp->v_type == VCHR || 2624 !vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) { 2625 VI_LOCK(vp); 2626 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2627 oweinact = 0; 2628 } else { 2629 oweinact = 1; 2630 vp->v_iflag &= ~VI_OWEINACT; 2631 } 2632 refcount_acquire(&vp->v_usecount); 2633 v_incr_devcount(vp); 2634 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2635 (flags & LK_NOWAIT) == 0) 2636 vinactive(vp, td); 2637 VI_UNLOCK(vp); 2638 } 2639 return (0); 2640 } 2641 2642 /* 2643 * Increase the reference (use) and hold count of a vnode. 2644 * This will also remove the vnode from the free list if it is presently free. 2645 */ 2646 void 2647 vref(struct vnode *vp) 2648 { 2649 2650 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2651 _vhold(vp, false); 2652 v_incr_usecount(vp); 2653 } 2654 2655 void 2656 vrefl(struct vnode *vp) 2657 { 2658 2659 ASSERT_VI_LOCKED(vp, __func__); 2660 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2661 _vhold(vp, true); 2662 v_incr_usecount_locked(vp); 2663 } 2664 2665 void 2666 vrefact(struct vnode *vp) 2667 { 2668 2669 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2670 if (__predict_false(vp->v_type == VCHR)) { 2671 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 2672 ("%s: wrong ref counts", __func__)); 2673 vref(vp); 2674 return; 2675 } 2676 #ifdef INVARIANTS 2677 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 2678 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__)); 2679 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2680 VNASSERT(old > 0, vp, ("%s: wrong use count", __func__)); 2681 #else 2682 refcount_acquire(&vp->v_holdcnt); 2683 refcount_acquire(&vp->v_usecount); 2684 #endif 2685 } 2686 2687 /* 2688 * Return reference count of a vnode. 2689 * 2690 * The results of this call are only guaranteed when some mechanism is used to 2691 * stop other processes from gaining references to the vnode. This may be the 2692 * case if the caller holds the only reference. This is also useful when stale 2693 * data is acceptable as race conditions may be accounted for by some other 2694 * means. 2695 */ 2696 int 2697 vrefcnt(struct vnode *vp) 2698 { 2699 2700 return (vp->v_usecount); 2701 } 2702 2703 #define VPUTX_VRELE 1 2704 #define VPUTX_VPUT 2 2705 #define VPUTX_VUNREF 3 2706 2707 /* 2708 * Decrement the use and hold counts for a vnode. 2709 * 2710 * See an explanation near vget() as to why atomic operation is safe. 2711 */ 2712 static void 2713 vputx(struct vnode *vp, int func) 2714 { 2715 int error; 2716 2717 KASSERT(vp != NULL, ("vputx: null vp")); 2718 if (func == VPUTX_VUNREF) 2719 ASSERT_VOP_LOCKED(vp, "vunref"); 2720 else if (func == VPUTX_VPUT) 2721 ASSERT_VOP_LOCKED(vp, "vput"); 2722 else 2723 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); 2724 ASSERT_VI_UNLOCKED(vp, __func__); 2725 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2726 2727 if (vp->v_type != VCHR && 2728 vfs_refcount_release_if_not_last(&vp->v_usecount)) { 2729 if (func == VPUTX_VPUT) 2730 VOP_UNLOCK(vp, 0); 2731 vdrop(vp); 2732 return; 2733 } 2734 2735 VI_LOCK(vp); 2736 2737 /* 2738 * We want to hold the vnode until the inactive finishes to 2739 * prevent vgone() races. We drop the use count here and the 2740 * hold count below when we're done. 2741 */ 2742 if (!refcount_release(&vp->v_usecount) || 2743 (vp->v_iflag & VI_DOINGINACT)) { 2744 if (func == VPUTX_VPUT) 2745 VOP_UNLOCK(vp, 0); 2746 v_decr_devcount(vp); 2747 vdropl(vp); 2748 return; 2749 } 2750 2751 v_decr_devcount(vp); 2752 2753 error = 0; 2754 2755 if (vp->v_usecount != 0) { 2756 vn_printf(vp, "vputx: usecount not zero for vnode "); 2757 panic("vputx: usecount not zero"); 2758 } 2759 2760 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); 2761 2762 /* 2763 * We must call VOP_INACTIVE with the node locked. Mark 2764 * as VI_DOINGINACT to avoid recursion. 2765 */ 2766 vp->v_iflag |= VI_OWEINACT; 2767 switch (func) { 2768 case VPUTX_VRELE: 2769 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2770 VI_LOCK(vp); 2771 break; 2772 case VPUTX_VPUT: 2773 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2774 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 2775 LK_NOWAIT); 2776 VI_LOCK(vp); 2777 } 2778 break; 2779 case VPUTX_VUNREF: 2780 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2781 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 2782 VI_LOCK(vp); 2783 } 2784 break; 2785 } 2786 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, 2787 ("vnode with usecount and VI_OWEINACT set")); 2788 if (error == 0) { 2789 if (vp->v_iflag & VI_OWEINACT) 2790 vinactive(vp, curthread); 2791 if (func != VPUTX_VUNREF) 2792 VOP_UNLOCK(vp, 0); 2793 } 2794 vdropl(vp); 2795 } 2796 2797 /* 2798 * Vnode put/release. 2799 * If count drops to zero, call inactive routine and return to freelist. 2800 */ 2801 void 2802 vrele(struct vnode *vp) 2803 { 2804 2805 vputx(vp, VPUTX_VRELE); 2806 } 2807 2808 /* 2809 * Release an already locked vnode. This give the same effects as 2810 * unlock+vrele(), but takes less time and avoids releasing and 2811 * re-aquiring the lock (as vrele() acquires the lock internally.) 2812 */ 2813 void 2814 vput(struct vnode *vp) 2815 { 2816 2817 vputx(vp, VPUTX_VPUT); 2818 } 2819 2820 /* 2821 * Release an exclusively locked vnode. Do not unlock the vnode lock. 2822 */ 2823 void 2824 vunref(struct vnode *vp) 2825 { 2826 2827 vputx(vp, VPUTX_VUNREF); 2828 } 2829 2830 /* 2831 * Increase the hold count and activate if this is the first reference. 2832 */ 2833 void 2834 _vhold(struct vnode *vp, bool locked) 2835 { 2836 struct mount *mp; 2837 2838 if (locked) 2839 ASSERT_VI_LOCKED(vp, __func__); 2840 else 2841 ASSERT_VI_UNLOCKED(vp, __func__); 2842 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2843 if (!locked) { 2844 if (vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt)) { 2845 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2846 ("_vhold: vnode with holdcnt is free")); 2847 return; 2848 } 2849 VI_LOCK(vp); 2850 } 2851 if ((vp->v_iflag & VI_FREE) == 0) { 2852 refcount_acquire(&vp->v_holdcnt); 2853 if (!locked) 2854 VI_UNLOCK(vp); 2855 return; 2856 } 2857 VNASSERT(vp->v_holdcnt == 0, vp, 2858 ("%s: wrong hold count", __func__)); 2859 VNASSERT(vp->v_op != NULL, vp, 2860 ("%s: vnode already reclaimed.", __func__)); 2861 /* 2862 * Remove a vnode from the free list, mark it as in use, 2863 * and put it on the active list. 2864 */ 2865 VNASSERT(vp->v_mount != NULL, vp, 2866 ("_vhold: vnode not on per mount vnode list")); 2867 mp = vp->v_mount; 2868 mtx_lock(&mp->mnt_listmtx); 2869 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { 2870 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 2871 mp->mnt_tmpfreevnodelistsize--; 2872 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 2873 } else { 2874 mtx_lock(&vnode_free_list_mtx); 2875 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 2876 freevnodes--; 2877 mtx_unlock(&vnode_free_list_mtx); 2878 } 2879 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 2880 ("Activating already active vnode")); 2881 vp->v_iflag &= ~VI_FREE; 2882 vp->v_iflag |= VI_ACTIVE; 2883 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 2884 mp->mnt_activevnodelistsize++; 2885 mtx_unlock(&mp->mnt_listmtx); 2886 refcount_acquire(&vp->v_holdcnt); 2887 if (!locked) 2888 VI_UNLOCK(vp); 2889 } 2890 2891 /* 2892 * Drop the hold count of the vnode. If this is the last reference to 2893 * the vnode we place it on the free list unless it has been vgone'd 2894 * (marked VI_DOOMED) in which case we will free it. 2895 * 2896 * Because the vnode vm object keeps a hold reference on the vnode if 2897 * there is at least one resident non-cached page, the vnode cannot 2898 * leave the active list without the page cleanup done. 2899 */ 2900 void 2901 _vdrop(struct vnode *vp, bool locked) 2902 { 2903 struct bufobj *bo; 2904 struct mount *mp; 2905 int active; 2906 2907 if (locked) 2908 ASSERT_VI_LOCKED(vp, __func__); 2909 else 2910 ASSERT_VI_UNLOCKED(vp, __func__); 2911 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2912 if ((int)vp->v_holdcnt <= 0) 2913 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2914 if (!locked) { 2915 if (vfs_refcount_release_if_not_last(&vp->v_holdcnt)) 2916 return; 2917 VI_LOCK(vp); 2918 } 2919 if (refcount_release(&vp->v_holdcnt) == 0) { 2920 VI_UNLOCK(vp); 2921 return; 2922 } 2923 if ((vp->v_iflag & VI_DOOMED) == 0) { 2924 /* 2925 * Mark a vnode as free: remove it from its active list 2926 * and put it up for recycling on the freelist. 2927 */ 2928 VNASSERT(vp->v_op != NULL, vp, 2929 ("vdropl: vnode already reclaimed.")); 2930 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2931 ("vnode already free")); 2932 VNASSERT(vp->v_holdcnt == 0, vp, 2933 ("vdropl: freeing when we shouldn't")); 2934 active = vp->v_iflag & VI_ACTIVE; 2935 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2936 vp->v_iflag &= ~VI_ACTIVE; 2937 mp = vp->v_mount; 2938 if (mp != NULL) { 2939 mtx_lock(&mp->mnt_listmtx); 2940 if (active) { 2941 TAILQ_REMOVE(&mp->mnt_activevnodelist, 2942 vp, v_actfreelist); 2943 mp->mnt_activevnodelistsize--; 2944 } 2945 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, 2946 vp, v_actfreelist); 2947 mp->mnt_tmpfreevnodelistsize++; 2948 vp->v_iflag |= VI_FREE; 2949 vp->v_mflag |= VMP_TMPMNTFREELIST; 2950 VI_UNLOCK(vp); 2951 if (mp->mnt_tmpfreevnodelistsize >= 2952 mnt_free_list_batch) 2953 vnlru_return_batch_locked(mp); 2954 mtx_unlock(&mp->mnt_listmtx); 2955 } else { 2956 VNASSERT(active == 0, vp, 2957 ("vdropl: active vnode not on per mount " 2958 "vnode list")); 2959 mtx_lock(&vnode_free_list_mtx); 2960 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 2961 v_actfreelist); 2962 freevnodes++; 2963 vp->v_iflag |= VI_FREE; 2964 VI_UNLOCK(vp); 2965 mtx_unlock(&vnode_free_list_mtx); 2966 } 2967 } else { 2968 VI_UNLOCK(vp); 2969 counter_u64_add(free_owe_inact, 1); 2970 } 2971 return; 2972 } 2973 /* 2974 * The vnode has been marked for destruction, so free it. 2975 * 2976 * The vnode will be returned to the zone where it will 2977 * normally remain until it is needed for another vnode. We 2978 * need to cleanup (or verify that the cleanup has already 2979 * been done) any residual data left from its current use 2980 * so as not to contaminate the freshly allocated vnode. 2981 */ 2982 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 2983 atomic_subtract_long(&numvnodes, 1); 2984 bo = &vp->v_bufobj; 2985 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2986 ("cleaned vnode still on the free list.")); 2987 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 2988 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 2989 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 2990 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 2991 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 2992 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 2993 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 2994 ("clean blk trie not empty")); 2995 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 2996 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 2997 ("dirty blk trie not empty")); 2998 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 2999 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 3000 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 3001 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 3002 ("Dangling rangelock waiters")); 3003 VI_UNLOCK(vp); 3004 #ifdef MAC 3005 mac_vnode_destroy(vp); 3006 #endif 3007 if (vp->v_pollinfo != NULL) { 3008 destroy_vpollinfo(vp->v_pollinfo); 3009 vp->v_pollinfo = NULL; 3010 } 3011 #ifdef INVARIANTS 3012 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 3013 vp->v_op = NULL; 3014 #endif 3015 vp->v_mountedhere = NULL; 3016 vp->v_unpcb = NULL; 3017 vp->v_rdev = NULL; 3018 vp->v_fifoinfo = NULL; 3019 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 3020 vp->v_iflag = 0; 3021 vp->v_vflag = 0; 3022 bo->bo_flag = 0; 3023 uma_zfree(vnode_zone, vp); 3024 } 3025 3026 /* 3027 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3028 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3029 * OWEINACT tracks whether a vnode missed a call to inactive due to a 3030 * failed lock upgrade. 3031 */ 3032 void 3033 vinactive(struct vnode *vp, struct thread *td) 3034 { 3035 struct vm_object *obj; 3036 3037 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3038 ASSERT_VI_LOCKED(vp, "vinactive"); 3039 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3040 ("vinactive: recursed on VI_DOINGINACT")); 3041 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3042 vp->v_iflag |= VI_DOINGINACT; 3043 vp->v_iflag &= ~VI_OWEINACT; 3044 VI_UNLOCK(vp); 3045 /* 3046 * Before moving off the active list, we must be sure that any 3047 * modified pages are converted into the vnode's dirty 3048 * buffers, since these will no longer be checked once the 3049 * vnode is on the inactive list. 3050 * 3051 * The write-out of the dirty pages is asynchronous. At the 3052 * point that VOP_INACTIVE() is called, there could still be 3053 * pending I/O and dirty pages in the object. 3054 */ 3055 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3056 (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { 3057 VM_OBJECT_WLOCK(obj); 3058 vm_object_page_clean(obj, 0, 0, 0); 3059 VM_OBJECT_WUNLOCK(obj); 3060 } 3061 VOP_INACTIVE(vp, td); 3062 VI_LOCK(vp); 3063 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3064 ("vinactive: lost VI_DOINGINACT")); 3065 vp->v_iflag &= ~VI_DOINGINACT; 3066 } 3067 3068 /* 3069 * Remove any vnodes in the vnode table belonging to mount point mp. 3070 * 3071 * If FORCECLOSE is not specified, there should not be any active ones, 3072 * return error if any are found (nb: this is a user error, not a 3073 * system error). If FORCECLOSE is specified, detach any active vnodes 3074 * that are found. 3075 * 3076 * If WRITECLOSE is set, only flush out regular file vnodes open for 3077 * writing. 3078 * 3079 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3080 * 3081 * `rootrefs' specifies the base reference count for the root vnode 3082 * of this filesystem. The root vnode is considered busy if its 3083 * v_usecount exceeds this value. On a successful return, vflush(, td) 3084 * will call vrele() on the root vnode exactly rootrefs times. 3085 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3086 * be zero. 3087 */ 3088 #ifdef DIAGNOSTIC 3089 static int busyprt = 0; /* print out busy vnodes */ 3090 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3091 #endif 3092 3093 int 3094 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3095 { 3096 struct vnode *vp, *mvp, *rootvp = NULL; 3097 struct vattr vattr; 3098 int busy = 0, error; 3099 3100 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3101 rootrefs, flags); 3102 if (rootrefs > 0) { 3103 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3104 ("vflush: bad args")); 3105 /* 3106 * Get the filesystem root vnode. We can vput() it 3107 * immediately, since with rootrefs > 0, it won't go away. 3108 */ 3109 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3110 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3111 __func__, error); 3112 return (error); 3113 } 3114 vput(rootvp); 3115 } 3116 loop: 3117 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3118 vholdl(vp); 3119 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3120 if (error) { 3121 vdrop(vp); 3122 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3123 goto loop; 3124 } 3125 /* 3126 * Skip over a vnodes marked VV_SYSTEM. 3127 */ 3128 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3129 VOP_UNLOCK(vp, 0); 3130 vdrop(vp); 3131 continue; 3132 } 3133 /* 3134 * If WRITECLOSE is set, flush out unlinked but still open 3135 * files (even if open only for reading) and regular file 3136 * vnodes open for writing. 3137 */ 3138 if (flags & WRITECLOSE) { 3139 if (vp->v_object != NULL) { 3140 VM_OBJECT_WLOCK(vp->v_object); 3141 vm_object_page_clean(vp->v_object, 0, 0, 0); 3142 VM_OBJECT_WUNLOCK(vp->v_object); 3143 } 3144 error = VOP_FSYNC(vp, MNT_WAIT, td); 3145 if (error != 0) { 3146 VOP_UNLOCK(vp, 0); 3147 vdrop(vp); 3148 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3149 return (error); 3150 } 3151 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3152 VI_LOCK(vp); 3153 3154 if ((vp->v_type == VNON || 3155 (error == 0 && vattr.va_nlink > 0)) && 3156 (vp->v_writecount == 0 || vp->v_type != VREG)) { 3157 VOP_UNLOCK(vp, 0); 3158 vdropl(vp); 3159 continue; 3160 } 3161 } else 3162 VI_LOCK(vp); 3163 /* 3164 * With v_usecount == 0, all we need to do is clear out the 3165 * vnode data structures and we are done. 3166 * 3167 * If FORCECLOSE is set, forcibly close the vnode. 3168 */ 3169 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3170 vgonel(vp); 3171 } else { 3172 busy++; 3173 #ifdef DIAGNOSTIC 3174 if (busyprt) 3175 vn_printf(vp, "vflush: busy vnode "); 3176 #endif 3177 } 3178 VOP_UNLOCK(vp, 0); 3179 vdropl(vp); 3180 } 3181 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3182 /* 3183 * If just the root vnode is busy, and if its refcount 3184 * is equal to `rootrefs', then go ahead and kill it. 3185 */ 3186 VI_LOCK(rootvp); 3187 KASSERT(busy > 0, ("vflush: not busy")); 3188 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3189 ("vflush: usecount %d < rootrefs %d", 3190 rootvp->v_usecount, rootrefs)); 3191 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3192 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3193 vgone(rootvp); 3194 VOP_UNLOCK(rootvp, 0); 3195 busy = 0; 3196 } else 3197 VI_UNLOCK(rootvp); 3198 } 3199 if (busy) { 3200 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3201 busy); 3202 return (EBUSY); 3203 } 3204 for (; rootrefs > 0; rootrefs--) 3205 vrele(rootvp); 3206 return (0); 3207 } 3208 3209 /* 3210 * Recycle an unused vnode to the front of the free list. 3211 */ 3212 int 3213 vrecycle(struct vnode *vp) 3214 { 3215 int recycled; 3216 3217 VI_LOCK(vp); 3218 recycled = vrecyclel(vp); 3219 VI_UNLOCK(vp); 3220 return (recycled); 3221 } 3222 3223 /* 3224 * vrecycle, with the vp interlock held. 3225 */ 3226 int 3227 vrecyclel(struct vnode *vp) 3228 { 3229 int recycled; 3230 3231 ASSERT_VOP_ELOCKED(vp, __func__); 3232 ASSERT_VI_LOCKED(vp, __func__); 3233 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3234 recycled = 0; 3235 if (vp->v_usecount == 0) { 3236 recycled = 1; 3237 vgonel(vp); 3238 } 3239 return (recycled); 3240 } 3241 3242 /* 3243 * Eliminate all activity associated with a vnode 3244 * in preparation for reuse. 3245 */ 3246 void 3247 vgone(struct vnode *vp) 3248 { 3249 VI_LOCK(vp); 3250 vgonel(vp); 3251 VI_UNLOCK(vp); 3252 } 3253 3254 static void 3255 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3256 struct vnode *lowervp __unused) 3257 { 3258 } 3259 3260 /* 3261 * Notify upper mounts about reclaimed or unlinked vnode. 3262 */ 3263 void 3264 vfs_notify_upper(struct vnode *vp, int event) 3265 { 3266 static struct vfsops vgonel_vfsops = { 3267 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3268 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3269 }; 3270 struct mount *mp, *ump, *mmp; 3271 3272 mp = vp->v_mount; 3273 if (mp == NULL) 3274 return; 3275 3276 MNT_ILOCK(mp); 3277 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3278 goto unlock; 3279 MNT_IUNLOCK(mp); 3280 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3281 mmp->mnt_op = &vgonel_vfsops; 3282 mmp->mnt_kern_flag |= MNTK_MARKER; 3283 MNT_ILOCK(mp); 3284 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3285 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3286 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3287 ump = TAILQ_NEXT(ump, mnt_upper_link); 3288 continue; 3289 } 3290 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3291 MNT_IUNLOCK(mp); 3292 switch (event) { 3293 case VFS_NOTIFY_UPPER_RECLAIM: 3294 VFS_RECLAIM_LOWERVP(ump, vp); 3295 break; 3296 case VFS_NOTIFY_UPPER_UNLINK: 3297 VFS_UNLINK_LOWERVP(ump, vp); 3298 break; 3299 default: 3300 KASSERT(0, ("invalid event %d", event)); 3301 break; 3302 } 3303 MNT_ILOCK(mp); 3304 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3305 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3306 } 3307 free(mmp, M_TEMP); 3308 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3309 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3310 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3311 wakeup(&mp->mnt_uppers); 3312 } 3313 unlock: 3314 MNT_IUNLOCK(mp); 3315 } 3316 3317 /* 3318 * vgone, with the vp interlock held. 3319 */ 3320 static void 3321 vgonel(struct vnode *vp) 3322 { 3323 struct thread *td; 3324 int oweinact; 3325 int active; 3326 struct mount *mp; 3327 3328 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3329 ASSERT_VI_LOCKED(vp, "vgonel"); 3330 VNASSERT(vp->v_holdcnt, vp, 3331 ("vgonel: vp %p has no reference.", vp)); 3332 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3333 td = curthread; 3334 3335 /* 3336 * Don't vgonel if we're already doomed. 3337 */ 3338 if (vp->v_iflag & VI_DOOMED) 3339 return; 3340 vp->v_iflag |= VI_DOOMED; 3341 3342 /* 3343 * Check to see if the vnode is in use. If so, we have to call 3344 * VOP_CLOSE() and VOP_INACTIVE(). 3345 */ 3346 active = vp->v_usecount; 3347 oweinact = (vp->v_iflag & VI_OWEINACT); 3348 VI_UNLOCK(vp); 3349 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3350 3351 /* 3352 * If purging an active vnode, it must be closed and 3353 * deactivated before being reclaimed. 3354 */ 3355 if (active) 3356 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3357 if (oweinact || active) { 3358 VI_LOCK(vp); 3359 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3360 vinactive(vp, td); 3361 VI_UNLOCK(vp); 3362 } 3363 if (vp->v_type == VSOCK) 3364 vfs_unp_reclaim(vp); 3365 3366 /* 3367 * Clean out any buffers associated with the vnode. 3368 * If the flush fails, just toss the buffers. 3369 */ 3370 mp = NULL; 3371 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3372 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3373 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3374 while (vinvalbuf(vp, 0, 0, 0) != 0) 3375 ; 3376 } 3377 3378 BO_LOCK(&vp->v_bufobj); 3379 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3380 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3381 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3382 vp->v_bufobj.bo_clean.bv_cnt == 0, 3383 ("vp %p bufobj not invalidated", vp)); 3384 3385 /* 3386 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate() 3387 * after the object's page queue is flushed. 3388 */ 3389 if (vp->v_bufobj.bo_object == NULL) 3390 vp->v_bufobj.bo_flag |= BO_DEAD; 3391 BO_UNLOCK(&vp->v_bufobj); 3392 3393 /* 3394 * Reclaim the vnode. 3395 */ 3396 if (VOP_RECLAIM(vp, td)) 3397 panic("vgone: cannot reclaim"); 3398 if (mp != NULL) 3399 vn_finished_secondary_write(mp); 3400 VNASSERT(vp->v_object == NULL, vp, 3401 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3402 /* 3403 * Clear the advisory locks and wake up waiting threads. 3404 */ 3405 (void)VOP_ADVLOCKPURGE(vp); 3406 vp->v_lockf = NULL; 3407 /* 3408 * Delete from old mount point vnode list. 3409 */ 3410 delmntque(vp); 3411 cache_purge(vp); 3412 /* 3413 * Done with purge, reset to the standard lock and invalidate 3414 * the vnode. 3415 */ 3416 VI_LOCK(vp); 3417 vp->v_vnlock = &vp->v_lock; 3418 vp->v_op = &dead_vnodeops; 3419 vp->v_tag = "none"; 3420 vp->v_type = VBAD; 3421 } 3422 3423 /* 3424 * Calculate the total number of references to a special device. 3425 */ 3426 int 3427 vcount(struct vnode *vp) 3428 { 3429 int count; 3430 3431 dev_lock(); 3432 count = vp->v_rdev->si_usecount; 3433 dev_unlock(); 3434 return (count); 3435 } 3436 3437 /* 3438 * Same as above, but using the struct cdev *as argument 3439 */ 3440 int 3441 count_dev(struct cdev *dev) 3442 { 3443 int count; 3444 3445 dev_lock(); 3446 count = dev->si_usecount; 3447 dev_unlock(); 3448 return(count); 3449 } 3450 3451 /* 3452 * Print out a description of a vnode. 3453 */ 3454 static char *typename[] = 3455 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3456 "VMARKER"}; 3457 3458 void 3459 vn_printf(struct vnode *vp, const char *fmt, ...) 3460 { 3461 va_list ap; 3462 char buf[256], buf2[16]; 3463 u_long flags; 3464 3465 va_start(ap, fmt); 3466 vprintf(fmt, ap); 3467 va_end(ap); 3468 printf("%p: ", (void *)vp); 3469 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3470 printf(" usecount %d, writecount %d, refcount %d", 3471 vp->v_usecount, vp->v_writecount, vp->v_holdcnt); 3472 switch (vp->v_type) { 3473 case VDIR: 3474 printf(" mountedhere %p\n", vp->v_mountedhere); 3475 break; 3476 case VCHR: 3477 printf(" rdev %p\n", vp->v_rdev); 3478 break; 3479 case VSOCK: 3480 printf(" socket %p\n", vp->v_unpcb); 3481 break; 3482 case VFIFO: 3483 printf(" fifoinfo %p\n", vp->v_fifoinfo); 3484 break; 3485 default: 3486 printf("\n"); 3487 break; 3488 } 3489 buf[0] = '\0'; 3490 buf[1] = '\0'; 3491 if (vp->v_vflag & VV_ROOT) 3492 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3493 if (vp->v_vflag & VV_ISTTY) 3494 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3495 if (vp->v_vflag & VV_NOSYNC) 3496 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3497 if (vp->v_vflag & VV_ETERNALDEV) 3498 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3499 if (vp->v_vflag & VV_CACHEDLABEL) 3500 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3501 if (vp->v_vflag & VV_TEXT) 3502 strlcat(buf, "|VV_TEXT", sizeof(buf)); 3503 if (vp->v_vflag & VV_COPYONWRITE) 3504 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3505 if (vp->v_vflag & VV_SYSTEM) 3506 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3507 if (vp->v_vflag & VV_PROCDEP) 3508 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3509 if (vp->v_vflag & VV_NOKNOTE) 3510 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3511 if (vp->v_vflag & VV_DELETED) 3512 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3513 if (vp->v_vflag & VV_MD) 3514 strlcat(buf, "|VV_MD", sizeof(buf)); 3515 if (vp->v_vflag & VV_FORCEINSMQ) 3516 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3517 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3518 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3519 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3520 if (flags != 0) { 3521 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3522 strlcat(buf, buf2, sizeof(buf)); 3523 } 3524 if (vp->v_iflag & VI_MOUNT) 3525 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3526 if (vp->v_iflag & VI_DOOMED) 3527 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 3528 if (vp->v_iflag & VI_FREE) 3529 strlcat(buf, "|VI_FREE", sizeof(buf)); 3530 if (vp->v_iflag & VI_ACTIVE) 3531 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3532 if (vp->v_iflag & VI_DOINGINACT) 3533 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3534 if (vp->v_iflag & VI_OWEINACT) 3535 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3536 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | 3537 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT); 3538 if (flags != 0) { 3539 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3540 strlcat(buf, buf2, sizeof(buf)); 3541 } 3542 printf(" flags (%s)\n", buf + 1); 3543 if (mtx_owned(VI_MTX(vp))) 3544 printf(" VI_LOCKed"); 3545 if (vp->v_object != NULL) 3546 printf(" v_object %p ref %d pages %d " 3547 "cleanbuf %d dirtybuf %d\n", 3548 vp->v_object, vp->v_object->ref_count, 3549 vp->v_object->resident_page_count, 3550 vp->v_bufobj.bo_clean.bv_cnt, 3551 vp->v_bufobj.bo_dirty.bv_cnt); 3552 printf(" "); 3553 lockmgr_printinfo(vp->v_vnlock); 3554 if (vp->v_data != NULL) 3555 VOP_PRINT(vp); 3556 } 3557 3558 #ifdef DDB 3559 /* 3560 * List all of the locked vnodes in the system. 3561 * Called when debugging the kernel. 3562 */ 3563 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3564 { 3565 struct mount *mp; 3566 struct vnode *vp; 3567 3568 /* 3569 * Note: because this is DDB, we can't obey the locking semantics 3570 * for these structures, which means we could catch an inconsistent 3571 * state and dereference a nasty pointer. Not much to be done 3572 * about that. 3573 */ 3574 db_printf("Locked vnodes\n"); 3575 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3576 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3577 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3578 vn_printf(vp, "vnode "); 3579 } 3580 } 3581 } 3582 3583 /* 3584 * Show details about the given vnode. 3585 */ 3586 DB_SHOW_COMMAND(vnode, db_show_vnode) 3587 { 3588 struct vnode *vp; 3589 3590 if (!have_addr) 3591 return; 3592 vp = (struct vnode *)addr; 3593 vn_printf(vp, "vnode "); 3594 } 3595 3596 /* 3597 * Show details about the given mount point. 3598 */ 3599 DB_SHOW_COMMAND(mount, db_show_mount) 3600 { 3601 struct mount *mp; 3602 struct vfsopt *opt; 3603 struct statfs *sp; 3604 struct vnode *vp; 3605 char buf[512]; 3606 uint64_t mflags; 3607 u_int flags; 3608 3609 if (!have_addr) { 3610 /* No address given, print short info about all mount points. */ 3611 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3612 db_printf("%p %s on %s (%s)\n", mp, 3613 mp->mnt_stat.f_mntfromname, 3614 mp->mnt_stat.f_mntonname, 3615 mp->mnt_stat.f_fstypename); 3616 if (db_pager_quit) 3617 break; 3618 } 3619 db_printf("\nMore info: show mount <addr>\n"); 3620 return; 3621 } 3622 3623 mp = (struct mount *)addr; 3624 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3625 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3626 3627 buf[0] = '\0'; 3628 mflags = mp->mnt_flag; 3629 #define MNT_FLAG(flag) do { \ 3630 if (mflags & (flag)) { \ 3631 if (buf[0] != '\0') \ 3632 strlcat(buf, ", ", sizeof(buf)); \ 3633 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3634 mflags &= ~(flag); \ 3635 } \ 3636 } while (0) 3637 MNT_FLAG(MNT_RDONLY); 3638 MNT_FLAG(MNT_SYNCHRONOUS); 3639 MNT_FLAG(MNT_NOEXEC); 3640 MNT_FLAG(MNT_NOSUID); 3641 MNT_FLAG(MNT_NFS4ACLS); 3642 MNT_FLAG(MNT_UNION); 3643 MNT_FLAG(MNT_ASYNC); 3644 MNT_FLAG(MNT_SUIDDIR); 3645 MNT_FLAG(MNT_SOFTDEP); 3646 MNT_FLAG(MNT_NOSYMFOLLOW); 3647 MNT_FLAG(MNT_GJOURNAL); 3648 MNT_FLAG(MNT_MULTILABEL); 3649 MNT_FLAG(MNT_ACLS); 3650 MNT_FLAG(MNT_NOATIME); 3651 MNT_FLAG(MNT_NOCLUSTERR); 3652 MNT_FLAG(MNT_NOCLUSTERW); 3653 MNT_FLAG(MNT_SUJ); 3654 MNT_FLAG(MNT_EXRDONLY); 3655 MNT_FLAG(MNT_EXPORTED); 3656 MNT_FLAG(MNT_DEFEXPORTED); 3657 MNT_FLAG(MNT_EXPORTANON); 3658 MNT_FLAG(MNT_EXKERB); 3659 MNT_FLAG(MNT_EXPUBLIC); 3660 MNT_FLAG(MNT_LOCAL); 3661 MNT_FLAG(MNT_QUOTA); 3662 MNT_FLAG(MNT_ROOTFS); 3663 MNT_FLAG(MNT_USER); 3664 MNT_FLAG(MNT_IGNORE); 3665 MNT_FLAG(MNT_UPDATE); 3666 MNT_FLAG(MNT_DELEXPORT); 3667 MNT_FLAG(MNT_RELOAD); 3668 MNT_FLAG(MNT_FORCE); 3669 MNT_FLAG(MNT_SNAPSHOT); 3670 MNT_FLAG(MNT_BYFSID); 3671 #undef MNT_FLAG 3672 if (mflags != 0) { 3673 if (buf[0] != '\0') 3674 strlcat(buf, ", ", sizeof(buf)); 3675 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3676 "0x%016jx", mflags); 3677 } 3678 db_printf(" mnt_flag = %s\n", buf); 3679 3680 buf[0] = '\0'; 3681 flags = mp->mnt_kern_flag; 3682 #define MNT_KERN_FLAG(flag) do { \ 3683 if (flags & (flag)) { \ 3684 if (buf[0] != '\0') \ 3685 strlcat(buf, ", ", sizeof(buf)); \ 3686 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3687 flags &= ~(flag); \ 3688 } \ 3689 } while (0) 3690 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3691 MNT_KERN_FLAG(MNTK_ASYNC); 3692 MNT_KERN_FLAG(MNTK_SOFTDEP); 3693 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 3694 MNT_KERN_FLAG(MNTK_DRAINING); 3695 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3696 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3697 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3698 MNT_KERN_FLAG(MNTK_NO_IOPF); 3699 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3700 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3701 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3702 MNT_KERN_FLAG(MNTK_MARKER); 3703 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3704 MNT_KERN_FLAG(MNTK_NOASYNC); 3705 MNT_KERN_FLAG(MNTK_UNMOUNT); 3706 MNT_KERN_FLAG(MNTK_MWAIT); 3707 MNT_KERN_FLAG(MNTK_SUSPEND); 3708 MNT_KERN_FLAG(MNTK_SUSPEND2); 3709 MNT_KERN_FLAG(MNTK_SUSPENDED); 3710 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3711 MNT_KERN_FLAG(MNTK_NOKNOTE); 3712 #undef MNT_KERN_FLAG 3713 if (flags != 0) { 3714 if (buf[0] != '\0') 3715 strlcat(buf, ", ", sizeof(buf)); 3716 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3717 "0x%08x", flags); 3718 } 3719 db_printf(" mnt_kern_flag = %s\n", buf); 3720 3721 db_printf(" mnt_opt = "); 3722 opt = TAILQ_FIRST(mp->mnt_opt); 3723 if (opt != NULL) { 3724 db_printf("%s", opt->name); 3725 opt = TAILQ_NEXT(opt, link); 3726 while (opt != NULL) { 3727 db_printf(", %s", opt->name); 3728 opt = TAILQ_NEXT(opt, link); 3729 } 3730 } 3731 db_printf("\n"); 3732 3733 sp = &mp->mnt_stat; 3734 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3735 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3736 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3737 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3738 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3739 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 3740 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 3741 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 3742 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 3743 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 3744 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 3745 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 3746 3747 db_printf(" mnt_cred = { uid=%u ruid=%u", 3748 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 3749 if (jailed(mp->mnt_cred)) 3750 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 3751 db_printf(" }\n"); 3752 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 3753 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 3754 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 3755 db_printf(" mnt_activevnodelistsize = %d\n", 3756 mp->mnt_activevnodelistsize); 3757 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 3758 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 3759 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 3760 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 3761 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); 3762 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 3763 db_printf(" mnt_secondary_accwrites = %d\n", 3764 mp->mnt_secondary_accwrites); 3765 db_printf(" mnt_gjprovider = %s\n", 3766 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 3767 3768 db_printf("\n\nList of active vnodes\n"); 3769 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 3770 if (vp->v_type != VMARKER) { 3771 vn_printf(vp, "vnode "); 3772 if (db_pager_quit) 3773 break; 3774 } 3775 } 3776 db_printf("\n\nList of inactive vnodes\n"); 3777 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3778 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 3779 vn_printf(vp, "vnode "); 3780 if (db_pager_quit) 3781 break; 3782 } 3783 } 3784 } 3785 #endif /* DDB */ 3786 3787 /* 3788 * Fill in a struct xvfsconf based on a struct vfsconf. 3789 */ 3790 static int 3791 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 3792 { 3793 struct xvfsconf xvfsp; 3794 3795 bzero(&xvfsp, sizeof(xvfsp)); 3796 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3797 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3798 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3799 xvfsp.vfc_flags = vfsp->vfc_flags; 3800 /* 3801 * These are unused in userland, we keep them 3802 * to not break binary compatibility. 3803 */ 3804 xvfsp.vfc_vfsops = NULL; 3805 xvfsp.vfc_next = NULL; 3806 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3807 } 3808 3809 #ifdef COMPAT_FREEBSD32 3810 struct xvfsconf32 { 3811 uint32_t vfc_vfsops; 3812 char vfc_name[MFSNAMELEN]; 3813 int32_t vfc_typenum; 3814 int32_t vfc_refcount; 3815 int32_t vfc_flags; 3816 uint32_t vfc_next; 3817 }; 3818 3819 static int 3820 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 3821 { 3822 struct xvfsconf32 xvfsp; 3823 3824 bzero(&xvfsp, sizeof(xvfsp)); 3825 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3826 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3827 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3828 xvfsp.vfc_flags = vfsp->vfc_flags; 3829 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3830 } 3831 #endif 3832 3833 /* 3834 * Top level filesystem related information gathering. 3835 */ 3836 static int 3837 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3838 { 3839 struct vfsconf *vfsp; 3840 int error; 3841 3842 error = 0; 3843 vfsconf_slock(); 3844 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3845 #ifdef COMPAT_FREEBSD32 3846 if (req->flags & SCTL_MASK32) 3847 error = vfsconf2x32(req, vfsp); 3848 else 3849 #endif 3850 error = vfsconf2x(req, vfsp); 3851 if (error) 3852 break; 3853 } 3854 vfsconf_sunlock(); 3855 return (error); 3856 } 3857 3858 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 3859 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 3860 "S,xvfsconf", "List of all configured filesystems"); 3861 3862 #ifndef BURN_BRIDGES 3863 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3864 3865 static int 3866 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3867 { 3868 int *name = (int *)arg1 - 1; /* XXX */ 3869 u_int namelen = arg2 + 1; /* XXX */ 3870 struct vfsconf *vfsp; 3871 3872 log(LOG_WARNING, "userland calling deprecated sysctl, " 3873 "please rebuild world\n"); 3874 3875 #if 1 || defined(COMPAT_PRELITE2) 3876 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3877 if (namelen == 1) 3878 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3879 #endif 3880 3881 switch (name[1]) { 3882 case VFS_MAXTYPENUM: 3883 if (namelen != 2) 3884 return (ENOTDIR); 3885 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3886 case VFS_CONF: 3887 if (namelen != 3) 3888 return (ENOTDIR); /* overloaded */ 3889 vfsconf_slock(); 3890 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3891 if (vfsp->vfc_typenum == name[2]) 3892 break; 3893 } 3894 vfsconf_sunlock(); 3895 if (vfsp == NULL) 3896 return (EOPNOTSUPP); 3897 #ifdef COMPAT_FREEBSD32 3898 if (req->flags & SCTL_MASK32) 3899 return (vfsconf2x32(req, vfsp)); 3900 else 3901 #endif 3902 return (vfsconf2x(req, vfsp)); 3903 } 3904 return (EOPNOTSUPP); 3905 } 3906 3907 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 3908 CTLFLAG_MPSAFE, vfs_sysctl, 3909 "Generic filesystem"); 3910 3911 #if 1 || defined(COMPAT_PRELITE2) 3912 3913 static int 3914 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3915 { 3916 int error; 3917 struct vfsconf *vfsp; 3918 struct ovfsconf ovfs; 3919 3920 vfsconf_slock(); 3921 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3922 bzero(&ovfs, sizeof(ovfs)); 3923 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3924 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3925 ovfs.vfc_index = vfsp->vfc_typenum; 3926 ovfs.vfc_refcount = vfsp->vfc_refcount; 3927 ovfs.vfc_flags = vfsp->vfc_flags; 3928 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3929 if (error != 0) { 3930 vfsconf_sunlock(); 3931 return (error); 3932 } 3933 } 3934 vfsconf_sunlock(); 3935 return (0); 3936 } 3937 3938 #endif /* 1 || COMPAT_PRELITE2 */ 3939 #endif /* !BURN_BRIDGES */ 3940 3941 #define KINFO_VNODESLOP 10 3942 #ifdef notyet 3943 /* 3944 * Dump vnode list (via sysctl). 3945 */ 3946 /* ARGSUSED */ 3947 static int 3948 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3949 { 3950 struct xvnode *xvn; 3951 struct mount *mp; 3952 struct vnode *vp; 3953 int error, len, n; 3954 3955 /* 3956 * Stale numvnodes access is not fatal here. 3957 */ 3958 req->lock = 0; 3959 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3960 if (!req->oldptr) 3961 /* Make an estimate */ 3962 return (SYSCTL_OUT(req, 0, len)); 3963 3964 error = sysctl_wire_old_buffer(req, 0); 3965 if (error != 0) 3966 return (error); 3967 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3968 n = 0; 3969 mtx_lock(&mountlist_mtx); 3970 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3971 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 3972 continue; 3973 MNT_ILOCK(mp); 3974 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3975 if (n == len) 3976 break; 3977 vref(vp); 3978 xvn[n].xv_size = sizeof *xvn; 3979 xvn[n].xv_vnode = vp; 3980 xvn[n].xv_id = 0; /* XXX compat */ 3981 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3982 XV_COPY(usecount); 3983 XV_COPY(writecount); 3984 XV_COPY(holdcnt); 3985 XV_COPY(mount); 3986 XV_COPY(numoutput); 3987 XV_COPY(type); 3988 #undef XV_COPY 3989 xvn[n].xv_flag = vp->v_vflag; 3990 3991 switch (vp->v_type) { 3992 case VREG: 3993 case VDIR: 3994 case VLNK: 3995 break; 3996 case VBLK: 3997 case VCHR: 3998 if (vp->v_rdev == NULL) { 3999 vrele(vp); 4000 continue; 4001 } 4002 xvn[n].xv_dev = dev2udev(vp->v_rdev); 4003 break; 4004 case VSOCK: 4005 xvn[n].xv_socket = vp->v_socket; 4006 break; 4007 case VFIFO: 4008 xvn[n].xv_fifo = vp->v_fifoinfo; 4009 break; 4010 case VNON: 4011 case VBAD: 4012 default: 4013 /* shouldn't happen? */ 4014 vrele(vp); 4015 continue; 4016 } 4017 vrele(vp); 4018 ++n; 4019 } 4020 MNT_IUNLOCK(mp); 4021 mtx_lock(&mountlist_mtx); 4022 vfs_unbusy(mp); 4023 if (n == len) 4024 break; 4025 } 4026 mtx_unlock(&mountlist_mtx); 4027 4028 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4029 free(xvn, M_TEMP); 4030 return (error); 4031 } 4032 4033 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4034 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4035 ""); 4036 #endif 4037 4038 static void 4039 unmount_or_warn(struct mount *mp) 4040 { 4041 int error; 4042 4043 error = dounmount(mp, MNT_FORCE, curthread); 4044 if (error != 0) { 4045 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4046 if (error == EBUSY) 4047 printf("BUSY)\n"); 4048 else 4049 printf("%d)\n", error); 4050 } 4051 } 4052 4053 /* 4054 * Unmount all filesystems. The list is traversed in reverse order 4055 * of mounting to avoid dependencies. 4056 */ 4057 void 4058 vfs_unmountall(void) 4059 { 4060 struct mount *mp, *tmp; 4061 4062 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4063 4064 /* 4065 * Since this only runs when rebooting, it is not interlocked. 4066 */ 4067 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4068 vfs_ref(mp); 4069 4070 /* 4071 * Forcibly unmounting "/dev" before "/" would prevent clean 4072 * unmount of the latter. 4073 */ 4074 if (mp == rootdevmp) 4075 continue; 4076 4077 unmount_or_warn(mp); 4078 } 4079 4080 if (rootdevmp != NULL) 4081 unmount_or_warn(rootdevmp); 4082 } 4083 4084 /* 4085 * perform msync on all vnodes under a mount point 4086 * the mount point must be locked. 4087 */ 4088 void 4089 vfs_msync(struct mount *mp, int flags) 4090 { 4091 struct vnode *vp, *mvp; 4092 struct vm_object *obj; 4093 4094 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4095 4096 vnlru_return_batch(mp); 4097 4098 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 4099 obj = vp->v_object; 4100 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 4101 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 4102 if (!vget(vp, 4103 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 4104 curthread)) { 4105 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 4106 vput(vp); 4107 continue; 4108 } 4109 4110 obj = vp->v_object; 4111 if (obj != NULL) { 4112 VM_OBJECT_WLOCK(obj); 4113 vm_object_page_clean(obj, 0, 0, 4114 flags == MNT_WAIT ? 4115 OBJPC_SYNC : OBJPC_NOSYNC); 4116 VM_OBJECT_WUNLOCK(obj); 4117 } 4118 vput(vp); 4119 } 4120 } else 4121 VI_UNLOCK(vp); 4122 } 4123 } 4124 4125 static void 4126 destroy_vpollinfo_free(struct vpollinfo *vi) 4127 { 4128 4129 knlist_destroy(&vi->vpi_selinfo.si_note); 4130 mtx_destroy(&vi->vpi_lock); 4131 uma_zfree(vnodepoll_zone, vi); 4132 } 4133 4134 static void 4135 destroy_vpollinfo(struct vpollinfo *vi) 4136 { 4137 4138 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4139 seldrain(&vi->vpi_selinfo); 4140 destroy_vpollinfo_free(vi); 4141 } 4142 4143 /* 4144 * Initialize per-vnode helper structure to hold poll-related state. 4145 */ 4146 void 4147 v_addpollinfo(struct vnode *vp) 4148 { 4149 struct vpollinfo *vi; 4150 4151 if (vp->v_pollinfo != NULL) 4152 return; 4153 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4154 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4155 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4156 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4157 VI_LOCK(vp); 4158 if (vp->v_pollinfo != NULL) { 4159 VI_UNLOCK(vp); 4160 destroy_vpollinfo_free(vi); 4161 return; 4162 } 4163 vp->v_pollinfo = vi; 4164 VI_UNLOCK(vp); 4165 } 4166 4167 /* 4168 * Record a process's interest in events which might happen to 4169 * a vnode. Because poll uses the historic select-style interface 4170 * internally, this routine serves as both the ``check for any 4171 * pending events'' and the ``record my interest in future events'' 4172 * functions. (These are done together, while the lock is held, 4173 * to avoid race conditions.) 4174 */ 4175 int 4176 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4177 { 4178 4179 v_addpollinfo(vp); 4180 mtx_lock(&vp->v_pollinfo->vpi_lock); 4181 if (vp->v_pollinfo->vpi_revents & events) { 4182 /* 4183 * This leaves events we are not interested 4184 * in available for the other process which 4185 * which presumably had requested them 4186 * (otherwise they would never have been 4187 * recorded). 4188 */ 4189 events &= vp->v_pollinfo->vpi_revents; 4190 vp->v_pollinfo->vpi_revents &= ~events; 4191 4192 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4193 return (events); 4194 } 4195 vp->v_pollinfo->vpi_events |= events; 4196 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4197 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4198 return (0); 4199 } 4200 4201 /* 4202 * Routine to create and manage a filesystem syncer vnode. 4203 */ 4204 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4205 static int sync_fsync(struct vop_fsync_args *); 4206 static int sync_inactive(struct vop_inactive_args *); 4207 static int sync_reclaim(struct vop_reclaim_args *); 4208 4209 static struct vop_vector sync_vnodeops = { 4210 .vop_bypass = VOP_EOPNOTSUPP, 4211 .vop_close = sync_close, /* close */ 4212 .vop_fsync = sync_fsync, /* fsync */ 4213 .vop_inactive = sync_inactive, /* inactive */ 4214 .vop_reclaim = sync_reclaim, /* reclaim */ 4215 .vop_lock1 = vop_stdlock, /* lock */ 4216 .vop_unlock = vop_stdunlock, /* unlock */ 4217 .vop_islocked = vop_stdislocked, /* islocked */ 4218 }; 4219 4220 /* 4221 * Create a new filesystem syncer vnode for the specified mount point. 4222 */ 4223 void 4224 vfs_allocate_syncvnode(struct mount *mp) 4225 { 4226 struct vnode *vp; 4227 struct bufobj *bo; 4228 static long start, incr, next; 4229 int error; 4230 4231 /* Allocate a new vnode */ 4232 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4233 if (error != 0) 4234 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4235 vp->v_type = VNON; 4236 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4237 vp->v_vflag |= VV_FORCEINSMQ; 4238 error = insmntque(vp, mp); 4239 if (error != 0) 4240 panic("vfs_allocate_syncvnode: insmntque() failed"); 4241 vp->v_vflag &= ~VV_FORCEINSMQ; 4242 VOP_UNLOCK(vp, 0); 4243 /* 4244 * Place the vnode onto the syncer worklist. We attempt to 4245 * scatter them about on the list so that they will go off 4246 * at evenly distributed times even if all the filesystems 4247 * are mounted at once. 4248 */ 4249 next += incr; 4250 if (next == 0 || next > syncer_maxdelay) { 4251 start /= 2; 4252 incr /= 2; 4253 if (start == 0) { 4254 start = syncer_maxdelay / 2; 4255 incr = syncer_maxdelay; 4256 } 4257 next = start; 4258 } 4259 bo = &vp->v_bufobj; 4260 BO_LOCK(bo); 4261 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4262 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4263 mtx_lock(&sync_mtx); 4264 sync_vnode_count++; 4265 if (mp->mnt_syncer == NULL) { 4266 mp->mnt_syncer = vp; 4267 vp = NULL; 4268 } 4269 mtx_unlock(&sync_mtx); 4270 BO_UNLOCK(bo); 4271 if (vp != NULL) { 4272 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4273 vgone(vp); 4274 vput(vp); 4275 } 4276 } 4277 4278 void 4279 vfs_deallocate_syncvnode(struct mount *mp) 4280 { 4281 struct vnode *vp; 4282 4283 mtx_lock(&sync_mtx); 4284 vp = mp->mnt_syncer; 4285 if (vp != NULL) 4286 mp->mnt_syncer = NULL; 4287 mtx_unlock(&sync_mtx); 4288 if (vp != NULL) 4289 vrele(vp); 4290 } 4291 4292 /* 4293 * Do a lazy sync of the filesystem. 4294 */ 4295 static int 4296 sync_fsync(struct vop_fsync_args *ap) 4297 { 4298 struct vnode *syncvp = ap->a_vp; 4299 struct mount *mp = syncvp->v_mount; 4300 int error, save; 4301 struct bufobj *bo; 4302 4303 /* 4304 * We only need to do something if this is a lazy evaluation. 4305 */ 4306 if (ap->a_waitfor != MNT_LAZY) 4307 return (0); 4308 4309 /* 4310 * Move ourselves to the back of the sync list. 4311 */ 4312 bo = &syncvp->v_bufobj; 4313 BO_LOCK(bo); 4314 vn_syncer_add_to_worklist(bo, syncdelay); 4315 BO_UNLOCK(bo); 4316 4317 /* 4318 * Walk the list of vnodes pushing all that are dirty and 4319 * not already on the sync list. 4320 */ 4321 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4322 return (0); 4323 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4324 vfs_unbusy(mp); 4325 return (0); 4326 } 4327 save = curthread_pflags_set(TDP_SYNCIO); 4328 vfs_msync(mp, MNT_NOWAIT); 4329 error = VFS_SYNC(mp, MNT_LAZY); 4330 curthread_pflags_restore(save); 4331 vn_finished_write(mp); 4332 vfs_unbusy(mp); 4333 return (error); 4334 } 4335 4336 /* 4337 * The syncer vnode is no referenced. 4338 */ 4339 static int 4340 sync_inactive(struct vop_inactive_args *ap) 4341 { 4342 4343 vgone(ap->a_vp); 4344 return (0); 4345 } 4346 4347 /* 4348 * The syncer vnode is no longer needed and is being decommissioned. 4349 * 4350 * Modifications to the worklist must be protected by sync_mtx. 4351 */ 4352 static int 4353 sync_reclaim(struct vop_reclaim_args *ap) 4354 { 4355 struct vnode *vp = ap->a_vp; 4356 struct bufobj *bo; 4357 4358 bo = &vp->v_bufobj; 4359 BO_LOCK(bo); 4360 mtx_lock(&sync_mtx); 4361 if (vp->v_mount->mnt_syncer == vp) 4362 vp->v_mount->mnt_syncer = NULL; 4363 if (bo->bo_flag & BO_ONWORKLST) { 4364 LIST_REMOVE(bo, bo_synclist); 4365 syncer_worklist_len--; 4366 sync_vnode_count--; 4367 bo->bo_flag &= ~BO_ONWORKLST; 4368 } 4369 mtx_unlock(&sync_mtx); 4370 BO_UNLOCK(bo); 4371 4372 return (0); 4373 } 4374 4375 /* 4376 * Check if vnode represents a disk device 4377 */ 4378 int 4379 vn_isdisk(struct vnode *vp, int *errp) 4380 { 4381 int error; 4382 4383 if (vp->v_type != VCHR) { 4384 error = ENOTBLK; 4385 goto out; 4386 } 4387 error = 0; 4388 dev_lock(); 4389 if (vp->v_rdev == NULL) 4390 error = ENXIO; 4391 else if (vp->v_rdev->si_devsw == NULL) 4392 error = ENXIO; 4393 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4394 error = ENOTBLK; 4395 dev_unlock(); 4396 out: 4397 if (errp != NULL) 4398 *errp = error; 4399 return (error == 0); 4400 } 4401 4402 /* 4403 * Common filesystem object access control check routine. Accepts a 4404 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4405 * and optional call-by-reference privused argument allowing vaccess() 4406 * to indicate to the caller whether privilege was used to satisfy the 4407 * request (obsoleted). Returns 0 on success, or an errno on failure. 4408 */ 4409 int 4410 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4411 accmode_t accmode, struct ucred *cred, int *privused) 4412 { 4413 accmode_t dac_granted; 4414 accmode_t priv_granted; 4415 4416 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4417 ("invalid bit in accmode")); 4418 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4419 ("VAPPEND without VWRITE")); 4420 4421 /* 4422 * Look for a normal, non-privileged way to access the file/directory 4423 * as requested. If it exists, go with that. 4424 */ 4425 4426 if (privused != NULL) 4427 *privused = 0; 4428 4429 dac_granted = 0; 4430 4431 /* Check the owner. */ 4432 if (cred->cr_uid == file_uid) { 4433 dac_granted |= VADMIN; 4434 if (file_mode & S_IXUSR) 4435 dac_granted |= VEXEC; 4436 if (file_mode & S_IRUSR) 4437 dac_granted |= VREAD; 4438 if (file_mode & S_IWUSR) 4439 dac_granted |= (VWRITE | VAPPEND); 4440 4441 if ((accmode & dac_granted) == accmode) 4442 return (0); 4443 4444 goto privcheck; 4445 } 4446 4447 /* Otherwise, check the groups (first match) */ 4448 if (groupmember(file_gid, cred)) { 4449 if (file_mode & S_IXGRP) 4450 dac_granted |= VEXEC; 4451 if (file_mode & S_IRGRP) 4452 dac_granted |= VREAD; 4453 if (file_mode & S_IWGRP) 4454 dac_granted |= (VWRITE | VAPPEND); 4455 4456 if ((accmode & dac_granted) == accmode) 4457 return (0); 4458 4459 goto privcheck; 4460 } 4461 4462 /* Otherwise, check everyone else. */ 4463 if (file_mode & S_IXOTH) 4464 dac_granted |= VEXEC; 4465 if (file_mode & S_IROTH) 4466 dac_granted |= VREAD; 4467 if (file_mode & S_IWOTH) 4468 dac_granted |= (VWRITE | VAPPEND); 4469 if ((accmode & dac_granted) == accmode) 4470 return (0); 4471 4472 privcheck: 4473 /* 4474 * Build a privilege mask to determine if the set of privileges 4475 * satisfies the requirements when combined with the granted mask 4476 * from above. For each privilege, if the privilege is required, 4477 * bitwise or the request type onto the priv_granted mask. 4478 */ 4479 priv_granted = 0; 4480 4481 if (type == VDIR) { 4482 /* 4483 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4484 * requests, instead of PRIV_VFS_EXEC. 4485 */ 4486 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4487 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 4488 priv_granted |= VEXEC; 4489 } else { 4490 /* 4491 * Ensure that at least one execute bit is on. Otherwise, 4492 * a privileged user will always succeed, and we don't want 4493 * this to happen unless the file really is executable. 4494 */ 4495 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4496 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4497 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 4498 priv_granted |= VEXEC; 4499 } 4500 4501 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4502 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 4503 priv_granted |= VREAD; 4504 4505 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4506 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 4507 priv_granted |= (VWRITE | VAPPEND); 4508 4509 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4510 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 4511 priv_granted |= VADMIN; 4512 4513 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4514 /* XXX audit: privilege used */ 4515 if (privused != NULL) 4516 *privused = 1; 4517 return (0); 4518 } 4519 4520 return ((accmode & VADMIN) ? EPERM : EACCES); 4521 } 4522 4523 /* 4524 * Credential check based on process requesting service, and per-attribute 4525 * permissions. 4526 */ 4527 int 4528 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4529 struct thread *td, accmode_t accmode) 4530 { 4531 4532 /* 4533 * Kernel-invoked always succeeds. 4534 */ 4535 if (cred == NOCRED) 4536 return (0); 4537 4538 /* 4539 * Do not allow privileged processes in jail to directly manipulate 4540 * system attributes. 4541 */ 4542 switch (attrnamespace) { 4543 case EXTATTR_NAMESPACE_SYSTEM: 4544 /* Potentially should be: return (EPERM); */ 4545 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 4546 case EXTATTR_NAMESPACE_USER: 4547 return (VOP_ACCESS(vp, accmode, cred, td)); 4548 default: 4549 return (EPERM); 4550 } 4551 } 4552 4553 #ifdef DEBUG_VFS_LOCKS 4554 /* 4555 * This only exists to suppress warnings from unlocked specfs accesses. It is 4556 * no longer ok to have an unlocked VFS. 4557 */ 4558 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4559 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4560 4561 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4562 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4563 "Drop into debugger on lock violation"); 4564 4565 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4566 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4567 0, "Check for interlock across VOPs"); 4568 4569 int vfs_badlock_print = 1; /* Print lock violations. */ 4570 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4571 0, "Print lock violations"); 4572 4573 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 4574 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 4575 0, "Print vnode details on lock violations"); 4576 4577 #ifdef KDB 4578 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4579 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4580 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4581 #endif 4582 4583 static void 4584 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4585 { 4586 4587 #ifdef KDB 4588 if (vfs_badlock_backtrace) 4589 kdb_backtrace(); 4590 #endif 4591 if (vfs_badlock_vnode) 4592 vn_printf(vp, "vnode "); 4593 if (vfs_badlock_print) 4594 printf("%s: %p %s\n", str, (void *)vp, msg); 4595 if (vfs_badlock_ddb) 4596 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4597 } 4598 4599 void 4600 assert_vi_locked(struct vnode *vp, const char *str) 4601 { 4602 4603 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4604 vfs_badlock("interlock is not locked but should be", str, vp); 4605 } 4606 4607 void 4608 assert_vi_unlocked(struct vnode *vp, const char *str) 4609 { 4610 4611 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4612 vfs_badlock("interlock is locked but should not be", str, vp); 4613 } 4614 4615 void 4616 assert_vop_locked(struct vnode *vp, const char *str) 4617 { 4618 int locked; 4619 4620 if (!IGNORE_LOCK(vp)) { 4621 locked = VOP_ISLOCKED(vp); 4622 if (locked == 0 || locked == LK_EXCLOTHER) 4623 vfs_badlock("is not locked but should be", str, vp); 4624 } 4625 } 4626 4627 void 4628 assert_vop_unlocked(struct vnode *vp, const char *str) 4629 { 4630 4631 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4632 vfs_badlock("is locked but should not be", str, vp); 4633 } 4634 4635 void 4636 assert_vop_elocked(struct vnode *vp, const char *str) 4637 { 4638 4639 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4640 vfs_badlock("is not exclusive locked but should be", str, vp); 4641 } 4642 #endif /* DEBUG_VFS_LOCKS */ 4643 4644 void 4645 vop_rename_fail(struct vop_rename_args *ap) 4646 { 4647 4648 if (ap->a_tvp != NULL) 4649 vput(ap->a_tvp); 4650 if (ap->a_tdvp == ap->a_tvp) 4651 vrele(ap->a_tdvp); 4652 else 4653 vput(ap->a_tdvp); 4654 vrele(ap->a_fdvp); 4655 vrele(ap->a_fvp); 4656 } 4657 4658 void 4659 vop_rename_pre(void *ap) 4660 { 4661 struct vop_rename_args *a = ap; 4662 4663 #ifdef DEBUG_VFS_LOCKS 4664 if (a->a_tvp) 4665 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4666 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4667 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4668 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4669 4670 /* Check the source (from). */ 4671 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4672 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4673 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4674 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4675 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4676 4677 /* Check the target. */ 4678 if (a->a_tvp) 4679 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4680 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4681 #endif 4682 if (a->a_tdvp != a->a_fdvp) 4683 vhold(a->a_fdvp); 4684 if (a->a_tvp != a->a_fvp) 4685 vhold(a->a_fvp); 4686 vhold(a->a_tdvp); 4687 if (a->a_tvp) 4688 vhold(a->a_tvp); 4689 } 4690 4691 #ifdef DEBUG_VFS_LOCKS 4692 void 4693 vop_strategy_pre(void *ap) 4694 { 4695 struct vop_strategy_args *a; 4696 struct buf *bp; 4697 4698 a = ap; 4699 bp = a->a_bp; 4700 4701 /* 4702 * Cluster ops lock their component buffers but not the IO container. 4703 */ 4704 if ((bp->b_flags & B_CLUSTER) != 0) 4705 return; 4706 4707 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4708 if (vfs_badlock_print) 4709 printf( 4710 "VOP_STRATEGY: bp is not locked but should be\n"); 4711 if (vfs_badlock_ddb) 4712 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4713 } 4714 } 4715 4716 void 4717 vop_lock_pre(void *ap) 4718 { 4719 struct vop_lock1_args *a = ap; 4720 4721 if ((a->a_flags & LK_INTERLOCK) == 0) 4722 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4723 else 4724 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 4725 } 4726 4727 void 4728 vop_lock_post(void *ap, int rc) 4729 { 4730 struct vop_lock1_args *a = ap; 4731 4732 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4733 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 4734 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 4735 } 4736 4737 void 4738 vop_unlock_pre(void *ap) 4739 { 4740 struct vop_unlock_args *a = ap; 4741 4742 if (a->a_flags & LK_INTERLOCK) 4743 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4744 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4745 } 4746 4747 void 4748 vop_unlock_post(void *ap, int rc) 4749 { 4750 struct vop_unlock_args *a = ap; 4751 4752 if (a->a_flags & LK_INTERLOCK) 4753 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4754 } 4755 #endif 4756 4757 void 4758 vop_create_post(void *ap, int rc) 4759 { 4760 struct vop_create_args *a = ap; 4761 4762 if (!rc) 4763 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4764 } 4765 4766 void 4767 vop_deleteextattr_post(void *ap, int rc) 4768 { 4769 struct vop_deleteextattr_args *a = ap; 4770 4771 if (!rc) 4772 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4773 } 4774 4775 void 4776 vop_link_post(void *ap, int rc) 4777 { 4778 struct vop_link_args *a = ap; 4779 4780 if (!rc) { 4781 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4782 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4783 } 4784 } 4785 4786 void 4787 vop_mkdir_post(void *ap, int rc) 4788 { 4789 struct vop_mkdir_args *a = ap; 4790 4791 if (!rc) 4792 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4793 } 4794 4795 void 4796 vop_mknod_post(void *ap, int rc) 4797 { 4798 struct vop_mknod_args *a = ap; 4799 4800 if (!rc) 4801 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4802 } 4803 4804 void 4805 vop_reclaim_post(void *ap, int rc) 4806 { 4807 struct vop_reclaim_args *a = ap; 4808 4809 if (!rc) 4810 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 4811 } 4812 4813 void 4814 vop_remove_post(void *ap, int rc) 4815 { 4816 struct vop_remove_args *a = ap; 4817 4818 if (!rc) { 4819 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4820 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4821 } 4822 } 4823 4824 void 4825 vop_rename_post(void *ap, int rc) 4826 { 4827 struct vop_rename_args *a = ap; 4828 long hint; 4829 4830 if (!rc) { 4831 hint = NOTE_WRITE; 4832 if (a->a_fdvp == a->a_tdvp) { 4833 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 4834 hint |= NOTE_LINK; 4835 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4836 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4837 } else { 4838 hint |= NOTE_EXTEND; 4839 if (a->a_fvp->v_type == VDIR) 4840 hint |= NOTE_LINK; 4841 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4842 4843 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 4844 a->a_tvp->v_type == VDIR) 4845 hint &= ~NOTE_LINK; 4846 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4847 } 4848 4849 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4850 if (a->a_tvp) 4851 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4852 } 4853 if (a->a_tdvp != a->a_fdvp) 4854 vdrop(a->a_fdvp); 4855 if (a->a_tvp != a->a_fvp) 4856 vdrop(a->a_fvp); 4857 vdrop(a->a_tdvp); 4858 if (a->a_tvp) 4859 vdrop(a->a_tvp); 4860 } 4861 4862 void 4863 vop_rmdir_post(void *ap, int rc) 4864 { 4865 struct vop_rmdir_args *a = ap; 4866 4867 if (!rc) { 4868 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4869 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4870 } 4871 } 4872 4873 void 4874 vop_setattr_post(void *ap, int rc) 4875 { 4876 struct vop_setattr_args *a = ap; 4877 4878 if (!rc) 4879 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4880 } 4881 4882 void 4883 vop_setextattr_post(void *ap, int rc) 4884 { 4885 struct vop_setextattr_args *a = ap; 4886 4887 if (!rc) 4888 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4889 } 4890 4891 void 4892 vop_symlink_post(void *ap, int rc) 4893 { 4894 struct vop_symlink_args *a = ap; 4895 4896 if (!rc) 4897 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4898 } 4899 4900 void 4901 vop_open_post(void *ap, int rc) 4902 { 4903 struct vop_open_args *a = ap; 4904 4905 if (!rc) 4906 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 4907 } 4908 4909 void 4910 vop_close_post(void *ap, int rc) 4911 { 4912 struct vop_close_args *a = ap; 4913 4914 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 4915 (a->a_vp->v_iflag & VI_DOOMED) == 0)) { 4916 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 4917 NOTE_CLOSE_WRITE : NOTE_CLOSE); 4918 } 4919 } 4920 4921 void 4922 vop_read_post(void *ap, int rc) 4923 { 4924 struct vop_read_args *a = ap; 4925 4926 if (!rc) 4927 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4928 } 4929 4930 void 4931 vop_readdir_post(void *ap, int rc) 4932 { 4933 struct vop_readdir_args *a = ap; 4934 4935 if (!rc) 4936 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4937 } 4938 4939 static struct knlist fs_knlist; 4940 4941 static void 4942 vfs_event_init(void *arg) 4943 { 4944 knlist_init_mtx(&fs_knlist, NULL); 4945 } 4946 /* XXX - correct order? */ 4947 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 4948 4949 void 4950 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 4951 { 4952 4953 KNOTE_UNLOCKED(&fs_knlist, event); 4954 } 4955 4956 static int filt_fsattach(struct knote *kn); 4957 static void filt_fsdetach(struct knote *kn); 4958 static int filt_fsevent(struct knote *kn, long hint); 4959 4960 struct filterops fs_filtops = { 4961 .f_isfd = 0, 4962 .f_attach = filt_fsattach, 4963 .f_detach = filt_fsdetach, 4964 .f_event = filt_fsevent 4965 }; 4966 4967 static int 4968 filt_fsattach(struct knote *kn) 4969 { 4970 4971 kn->kn_flags |= EV_CLEAR; 4972 knlist_add(&fs_knlist, kn, 0); 4973 return (0); 4974 } 4975 4976 static void 4977 filt_fsdetach(struct knote *kn) 4978 { 4979 4980 knlist_remove(&fs_knlist, kn, 0); 4981 } 4982 4983 static int 4984 filt_fsevent(struct knote *kn, long hint) 4985 { 4986 4987 kn->kn_fflags |= hint; 4988 return (kn->kn_fflags != 0); 4989 } 4990 4991 static int 4992 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 4993 { 4994 struct vfsidctl vc; 4995 int error; 4996 struct mount *mp; 4997 4998 error = SYSCTL_IN(req, &vc, sizeof(vc)); 4999 if (error) 5000 return (error); 5001 if (vc.vc_vers != VFS_CTL_VERS1) 5002 return (EINVAL); 5003 mp = vfs_getvfs(&vc.vc_fsid); 5004 if (mp == NULL) 5005 return (ENOENT); 5006 /* ensure that a specific sysctl goes to the right filesystem. */ 5007 if (strcmp(vc.vc_fstypename, "*") != 0 && 5008 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 5009 vfs_rel(mp); 5010 return (EINVAL); 5011 } 5012 VCTLTOREQ(&vc, req); 5013 error = VFS_SYSCTL(mp, vc.vc_op, req); 5014 vfs_rel(mp); 5015 return (error); 5016 } 5017 5018 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 5019 NULL, 0, sysctl_vfs_ctl, "", 5020 "Sysctl by fsid"); 5021 5022 /* 5023 * Function to initialize a va_filerev field sensibly. 5024 * XXX: Wouldn't a random number make a lot more sense ?? 5025 */ 5026 u_quad_t 5027 init_va_filerev(void) 5028 { 5029 struct bintime bt; 5030 5031 getbinuptime(&bt); 5032 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5033 } 5034 5035 static int filt_vfsread(struct knote *kn, long hint); 5036 static int filt_vfswrite(struct knote *kn, long hint); 5037 static int filt_vfsvnode(struct knote *kn, long hint); 5038 static void filt_vfsdetach(struct knote *kn); 5039 static struct filterops vfsread_filtops = { 5040 .f_isfd = 1, 5041 .f_detach = filt_vfsdetach, 5042 .f_event = filt_vfsread 5043 }; 5044 static struct filterops vfswrite_filtops = { 5045 .f_isfd = 1, 5046 .f_detach = filt_vfsdetach, 5047 .f_event = filt_vfswrite 5048 }; 5049 static struct filterops vfsvnode_filtops = { 5050 .f_isfd = 1, 5051 .f_detach = filt_vfsdetach, 5052 .f_event = filt_vfsvnode 5053 }; 5054 5055 static void 5056 vfs_knllock(void *arg) 5057 { 5058 struct vnode *vp = arg; 5059 5060 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5061 } 5062 5063 static void 5064 vfs_knlunlock(void *arg) 5065 { 5066 struct vnode *vp = arg; 5067 5068 VOP_UNLOCK(vp, 0); 5069 } 5070 5071 static void 5072 vfs_knl_assert_locked(void *arg) 5073 { 5074 #ifdef DEBUG_VFS_LOCKS 5075 struct vnode *vp = arg; 5076 5077 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5078 #endif 5079 } 5080 5081 static void 5082 vfs_knl_assert_unlocked(void *arg) 5083 { 5084 #ifdef DEBUG_VFS_LOCKS 5085 struct vnode *vp = arg; 5086 5087 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5088 #endif 5089 } 5090 5091 int 5092 vfs_kqfilter(struct vop_kqfilter_args *ap) 5093 { 5094 struct vnode *vp = ap->a_vp; 5095 struct knote *kn = ap->a_kn; 5096 struct knlist *knl; 5097 5098 switch (kn->kn_filter) { 5099 case EVFILT_READ: 5100 kn->kn_fop = &vfsread_filtops; 5101 break; 5102 case EVFILT_WRITE: 5103 kn->kn_fop = &vfswrite_filtops; 5104 break; 5105 case EVFILT_VNODE: 5106 kn->kn_fop = &vfsvnode_filtops; 5107 break; 5108 default: 5109 return (EINVAL); 5110 } 5111 5112 kn->kn_hook = (caddr_t)vp; 5113 5114 v_addpollinfo(vp); 5115 if (vp->v_pollinfo == NULL) 5116 return (ENOMEM); 5117 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5118 vhold(vp); 5119 knlist_add(knl, kn, 0); 5120 5121 return (0); 5122 } 5123 5124 /* 5125 * Detach knote from vnode 5126 */ 5127 static void 5128 filt_vfsdetach(struct knote *kn) 5129 { 5130 struct vnode *vp = (struct vnode *)kn->kn_hook; 5131 5132 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5133 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5134 vdrop(vp); 5135 } 5136 5137 /*ARGSUSED*/ 5138 static int 5139 filt_vfsread(struct knote *kn, long hint) 5140 { 5141 struct vnode *vp = (struct vnode *)kn->kn_hook; 5142 struct vattr va; 5143 int res; 5144 5145 /* 5146 * filesystem is gone, so set the EOF flag and schedule 5147 * the knote for deletion. 5148 */ 5149 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5150 VI_LOCK(vp); 5151 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5152 VI_UNLOCK(vp); 5153 return (1); 5154 } 5155 5156 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5157 return (0); 5158 5159 VI_LOCK(vp); 5160 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5161 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5162 VI_UNLOCK(vp); 5163 return (res); 5164 } 5165 5166 /*ARGSUSED*/ 5167 static int 5168 filt_vfswrite(struct knote *kn, long hint) 5169 { 5170 struct vnode *vp = (struct vnode *)kn->kn_hook; 5171 5172 VI_LOCK(vp); 5173 5174 /* 5175 * filesystem is gone, so set the EOF flag and schedule 5176 * the knote for deletion. 5177 */ 5178 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5179 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5180 5181 kn->kn_data = 0; 5182 VI_UNLOCK(vp); 5183 return (1); 5184 } 5185 5186 static int 5187 filt_vfsvnode(struct knote *kn, long hint) 5188 { 5189 struct vnode *vp = (struct vnode *)kn->kn_hook; 5190 int res; 5191 5192 VI_LOCK(vp); 5193 if (kn->kn_sfflags & hint) 5194 kn->kn_fflags |= hint; 5195 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5196 kn->kn_flags |= EV_EOF; 5197 VI_UNLOCK(vp); 5198 return (1); 5199 } 5200 res = (kn->kn_fflags != 0); 5201 VI_UNLOCK(vp); 5202 return (res); 5203 } 5204 5205 int 5206 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5207 { 5208 int error; 5209 5210 if (dp->d_reclen > ap->a_uio->uio_resid) 5211 return (ENAMETOOLONG); 5212 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5213 if (error) { 5214 if (ap->a_ncookies != NULL) { 5215 if (ap->a_cookies != NULL) 5216 free(ap->a_cookies, M_TEMP); 5217 ap->a_cookies = NULL; 5218 *ap->a_ncookies = 0; 5219 } 5220 return (error); 5221 } 5222 if (ap->a_ncookies == NULL) 5223 return (0); 5224 5225 KASSERT(ap->a_cookies, 5226 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5227 5228 *ap->a_cookies = realloc(*ap->a_cookies, 5229 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5230 (*ap->a_cookies)[*ap->a_ncookies] = off; 5231 *ap->a_ncookies += 1; 5232 return (0); 5233 } 5234 5235 /* 5236 * Mark for update the access time of the file if the filesystem 5237 * supports VOP_MARKATIME. This functionality is used by execve and 5238 * mmap, so we want to avoid the I/O implied by directly setting 5239 * va_atime for the sake of efficiency. 5240 */ 5241 void 5242 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5243 { 5244 struct mount *mp; 5245 5246 mp = vp->v_mount; 5247 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5248 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5249 (void)VOP_MARKATIME(vp); 5250 } 5251 5252 /* 5253 * The purpose of this routine is to remove granularity from accmode_t, 5254 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5255 * VADMIN and VAPPEND. 5256 * 5257 * If it returns 0, the caller is supposed to continue with the usual 5258 * access checks using 'accmode' as modified by this routine. If it 5259 * returns nonzero value, the caller is supposed to return that value 5260 * as errno. 5261 * 5262 * Note that after this routine runs, accmode may be zero. 5263 */ 5264 int 5265 vfs_unixify_accmode(accmode_t *accmode) 5266 { 5267 /* 5268 * There is no way to specify explicit "deny" rule using 5269 * file mode or POSIX.1e ACLs. 5270 */ 5271 if (*accmode & VEXPLICIT_DENY) { 5272 *accmode = 0; 5273 return (0); 5274 } 5275 5276 /* 5277 * None of these can be translated into usual access bits. 5278 * Also, the common case for NFSv4 ACLs is to not contain 5279 * either of these bits. Caller should check for VWRITE 5280 * on the containing directory instead. 5281 */ 5282 if (*accmode & (VDELETE_CHILD | VDELETE)) 5283 return (EPERM); 5284 5285 if (*accmode & VADMIN_PERMS) { 5286 *accmode &= ~VADMIN_PERMS; 5287 *accmode |= VADMIN; 5288 } 5289 5290 /* 5291 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 5292 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 5293 */ 5294 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 5295 5296 return (0); 5297 } 5298 5299 /* 5300 * These are helper functions for filesystems to traverse all 5301 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 5302 * 5303 * This interface replaces MNT_VNODE_FOREACH. 5304 */ 5305 5306 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 5307 5308 struct vnode * 5309 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5310 { 5311 struct vnode *vp; 5312 5313 if (should_yield()) 5314 kern_yield(PRI_USER); 5315 MNT_ILOCK(mp); 5316 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5317 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 5318 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 5319 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5320 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5321 continue; 5322 VI_LOCK(vp); 5323 if ((vp->v_iflag & VI_DOOMED) != 0) { 5324 VI_UNLOCK(vp); 5325 continue; 5326 } 5327 break; 5328 } 5329 if (vp == NULL) { 5330 __mnt_vnode_markerfree_all(mvp, mp); 5331 /* MNT_IUNLOCK(mp); -- done in above function */ 5332 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5333 return (NULL); 5334 } 5335 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5336 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5337 MNT_IUNLOCK(mp); 5338 return (vp); 5339 } 5340 5341 struct vnode * 5342 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5343 { 5344 struct vnode *vp; 5345 5346 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5347 MNT_ILOCK(mp); 5348 MNT_REF(mp); 5349 (*mvp)->v_mount = mp; 5350 (*mvp)->v_type = VMARKER; 5351 5352 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 5353 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5354 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5355 continue; 5356 VI_LOCK(vp); 5357 if ((vp->v_iflag & VI_DOOMED) != 0) { 5358 VI_UNLOCK(vp); 5359 continue; 5360 } 5361 break; 5362 } 5363 if (vp == NULL) { 5364 MNT_REL(mp); 5365 MNT_IUNLOCK(mp); 5366 free(*mvp, M_VNODE_MARKER); 5367 *mvp = NULL; 5368 return (NULL); 5369 } 5370 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5371 MNT_IUNLOCK(mp); 5372 return (vp); 5373 } 5374 5375 void 5376 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5377 { 5378 5379 if (*mvp == NULL) { 5380 MNT_IUNLOCK(mp); 5381 return; 5382 } 5383 5384 mtx_assert(MNT_MTX(mp), MA_OWNED); 5385 5386 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5387 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5388 MNT_REL(mp); 5389 MNT_IUNLOCK(mp); 5390 free(*mvp, M_VNODE_MARKER); 5391 *mvp = NULL; 5392 } 5393 5394 /* 5395 * These are helper functions for filesystems to traverse their 5396 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5397 */ 5398 static void 5399 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5400 { 5401 5402 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5403 5404 MNT_ILOCK(mp); 5405 MNT_REL(mp); 5406 MNT_IUNLOCK(mp); 5407 free(*mvp, M_VNODE_MARKER); 5408 *mvp = NULL; 5409 } 5410 5411 /* 5412 * Relock the mp mount vnode list lock with the vp vnode interlock in the 5413 * conventional lock order during mnt_vnode_next_active iteration. 5414 * 5415 * On entry, the mount vnode list lock is held and the vnode interlock is not. 5416 * The list lock is dropped and reacquired. On success, both locks are held. 5417 * On failure, the mount vnode list lock is held but the vnode interlock is 5418 * not, and the procedure may have yielded. 5419 */ 5420 static bool 5421 mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp, 5422 struct vnode *vp) 5423 { 5424 const struct vnode *tmp; 5425 bool held, ret; 5426 5427 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 5428 TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp, 5429 ("%s: bad marker", __func__)); 5430 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 5431 ("%s: inappropriate vnode", __func__)); 5432 ASSERT_VI_UNLOCKED(vp, __func__); 5433 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5434 5435 ret = false; 5436 5437 TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist); 5438 TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist); 5439 5440 /* 5441 * Use a hold to prevent vp from disappearing while the mount vnode 5442 * list lock is dropped and reacquired. Normally a hold would be 5443 * acquired with vhold(), but that might try to acquire the vnode 5444 * interlock, which would be a LOR with the mount vnode list lock. 5445 */ 5446 held = vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt); 5447 mtx_unlock(&mp->mnt_listmtx); 5448 if (!held) 5449 goto abort; 5450 VI_LOCK(vp); 5451 if (!vfs_refcount_release_if_not_last(&vp->v_holdcnt)) { 5452 vdropl(vp); 5453 goto abort; 5454 } 5455 mtx_lock(&mp->mnt_listmtx); 5456 5457 /* 5458 * Determine whether the vnode is still the next one after the marker, 5459 * excepting any other markers. If the vnode has not been doomed by 5460 * vgone() then the hold should have ensured that it remained on the 5461 * active list. If it has been doomed but is still on the active list, 5462 * don't abort, but rather skip over it (avoid spinning on doomed 5463 * vnodes). 5464 */ 5465 tmp = mvp; 5466 do { 5467 tmp = TAILQ_NEXT(tmp, v_actfreelist); 5468 } while (tmp != NULL && tmp->v_type == VMARKER); 5469 if (tmp != vp) { 5470 mtx_unlock(&mp->mnt_listmtx); 5471 VI_UNLOCK(vp); 5472 goto abort; 5473 } 5474 5475 ret = true; 5476 goto out; 5477 abort: 5478 maybe_yield(); 5479 mtx_lock(&mp->mnt_listmtx); 5480 out: 5481 if (ret) 5482 ASSERT_VI_LOCKED(vp, __func__); 5483 else 5484 ASSERT_VI_UNLOCKED(vp, __func__); 5485 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5486 return (ret); 5487 } 5488 5489 static struct vnode * 5490 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5491 { 5492 struct vnode *vp, *nvp; 5493 5494 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5495 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5496 restart: 5497 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5498 while (vp != NULL) { 5499 if (vp->v_type == VMARKER) { 5500 vp = TAILQ_NEXT(vp, v_actfreelist); 5501 continue; 5502 } 5503 /* 5504 * Try-lock because this is the wrong lock order. If that does 5505 * not succeed, drop the mount vnode list lock and try to 5506 * reacquire it and the vnode interlock in the right order. 5507 */ 5508 if (!VI_TRYLOCK(vp) && 5509 !mnt_vnode_next_active_relock(*mvp, mp, vp)) 5510 goto restart; 5511 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5512 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5513 ("alien vnode on the active list %p %p", vp, mp)); 5514 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) 5515 break; 5516 nvp = TAILQ_NEXT(vp, v_actfreelist); 5517 VI_UNLOCK(vp); 5518 vp = nvp; 5519 } 5520 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5521 5522 /* Check if we are done */ 5523 if (vp == NULL) { 5524 mtx_unlock(&mp->mnt_listmtx); 5525 mnt_vnode_markerfree_active(mvp, mp); 5526 return (NULL); 5527 } 5528 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 5529 mtx_unlock(&mp->mnt_listmtx); 5530 ASSERT_VI_LOCKED(vp, "active iter"); 5531 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 5532 return (vp); 5533 } 5534 5535 struct vnode * 5536 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5537 { 5538 5539 if (should_yield()) 5540 kern_yield(PRI_USER); 5541 mtx_lock(&mp->mnt_listmtx); 5542 return (mnt_vnode_next_active(mvp, mp)); 5543 } 5544 5545 struct vnode * 5546 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 5547 { 5548 struct vnode *vp; 5549 5550 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5551 MNT_ILOCK(mp); 5552 MNT_REF(mp); 5553 MNT_IUNLOCK(mp); 5554 (*mvp)->v_type = VMARKER; 5555 (*mvp)->v_mount = mp; 5556 5557 mtx_lock(&mp->mnt_listmtx); 5558 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 5559 if (vp == NULL) { 5560 mtx_unlock(&mp->mnt_listmtx); 5561 mnt_vnode_markerfree_active(mvp, mp); 5562 return (NULL); 5563 } 5564 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5565 return (mnt_vnode_next_active(mvp, mp)); 5566 } 5567 5568 void 5569 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5570 { 5571 5572 if (*mvp == NULL) 5573 return; 5574 5575 mtx_lock(&mp->mnt_listmtx); 5576 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5577 mtx_unlock(&mp->mnt_listmtx); 5578 mnt_vnode_markerfree_active(mvp, mp); 5579 } 5580