1 /*- 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 35 */ 36 37 /* 38 * External virtual filesystem routines 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_compat.h" 45 #include "opt_ddb.h" 46 #include "opt_watchdog.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/bio.h> 51 #include <sys/buf.h> 52 #include <sys/condvar.h> 53 #include <sys/conf.h> 54 #include <sys/counter.h> 55 #include <sys/dirent.h> 56 #include <sys/event.h> 57 #include <sys/eventhandler.h> 58 #include <sys/extattr.h> 59 #include <sys/file.h> 60 #include <sys/fcntl.h> 61 #include <sys/jail.h> 62 #include <sys/kdb.h> 63 #include <sys/kernel.h> 64 #include <sys/kthread.h> 65 #include <sys/lockf.h> 66 #include <sys/malloc.h> 67 #include <sys/mount.h> 68 #include <sys/namei.h> 69 #include <sys/pctrie.h> 70 #include <sys/priv.h> 71 #include <sys/reboot.h> 72 #include <sys/refcount.h> 73 #include <sys/rwlock.h> 74 #include <sys/sched.h> 75 #include <sys/sleepqueue.h> 76 #include <sys/smp.h> 77 #include <sys/stat.h> 78 #include <sys/sysctl.h> 79 #include <sys/syslog.h> 80 #include <sys/vmmeter.h> 81 #include <sys/vnode.h> 82 #include <sys/watchdog.h> 83 84 #include <machine/stdarg.h> 85 86 #include <security/mac/mac_framework.h> 87 88 #include <vm/vm.h> 89 #include <vm/vm_object.h> 90 #include <vm/vm_extern.h> 91 #include <vm/pmap.h> 92 #include <vm/vm_map.h> 93 #include <vm/vm_page.h> 94 #include <vm/vm_kern.h> 95 #include <vm/uma.h> 96 97 #ifdef DDB 98 #include <ddb/ddb.h> 99 #endif 100 101 static void delmntque(struct vnode *vp); 102 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 103 int slpflag, int slptimeo); 104 static void syncer_shutdown(void *arg, int howto); 105 static int vtryrecycle(struct vnode *vp); 106 static void v_init_counters(struct vnode *); 107 static void v_incr_usecount(struct vnode *); 108 static void v_incr_usecount_locked(struct vnode *); 109 static void v_incr_devcount(struct vnode *); 110 static void v_decr_devcount(struct vnode *); 111 static void vgonel(struct vnode *); 112 static void vfs_knllock(void *arg); 113 static void vfs_knlunlock(void *arg); 114 static void vfs_knl_assert_locked(void *arg); 115 static void vfs_knl_assert_unlocked(void *arg); 116 static void vnlru_return_batches(struct vfsops *mnt_op); 117 static void destroy_vpollinfo(struct vpollinfo *vi); 118 119 /* 120 * Number of vnodes in existence. Increased whenever getnewvnode() 121 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode. 122 */ 123 static unsigned long numvnodes; 124 125 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 126 "Number of vnodes in existence"); 127 128 static counter_u64_t vnodes_created; 129 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 130 "Number of vnodes created by getnewvnode"); 131 132 static u_long mnt_free_list_batch = 128; 133 SYSCTL_ULONG(_vfs, OID_AUTO, mnt_free_list_batch, CTLFLAG_RW, 134 &mnt_free_list_batch, 0, "Limit of vnodes held on mnt's free list"); 135 136 /* 137 * Conversion tables for conversion from vnode types to inode formats 138 * and back. 139 */ 140 enum vtype iftovt_tab[16] = { 141 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 142 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 143 }; 144 int vttoif_tab[10] = { 145 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 146 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 147 }; 148 149 /* 150 * List of vnodes that are ready for recycling. 151 */ 152 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 153 154 /* 155 * "Free" vnode target. Free vnodes are rarely completely free, but are 156 * just ones that are cheap to recycle. Usually they are for files which 157 * have been stat'd but not read; these usually have inode and namecache 158 * data attached to them. This target is the preferred minimum size of a 159 * sub-cache consisting mostly of such files. The system balances the size 160 * of this sub-cache with its complement to try to prevent either from 161 * thrashing while the other is relatively inactive. The targets express 162 * a preference for the best balance. 163 * 164 * "Above" this target there are 2 further targets (watermarks) related 165 * to recyling of free vnodes. In the best-operating case, the cache is 166 * exactly full, the free list has size between vlowat and vhiwat above the 167 * free target, and recycling from it and normal use maintains this state. 168 * Sometimes the free list is below vlowat or even empty, but this state 169 * is even better for immediate use provided the cache is not full. 170 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 171 * ones) to reach one of these states. The watermarks are currently hard- 172 * coded as 4% and 9% of the available space higher. These and the default 173 * of 25% for wantfreevnodes are too large if the memory size is large. 174 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 175 * whenever vnlru_proc() becomes active. 176 */ 177 static u_long wantfreevnodes; 178 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, 179 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes"); 180 static u_long freevnodes; 181 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 182 &freevnodes, 0, "Number of \"free\" vnodes"); 183 184 static counter_u64_t recycles_count; 185 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 186 "Number of vnodes recycled to meet vnode cache targets"); 187 188 /* 189 * Various variables used for debugging the new implementation of 190 * reassignbuf(). 191 * XXX these are probably of (very) limited utility now. 192 */ 193 static int reassignbufcalls; 194 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, 195 "Number of calls to reassignbuf"); 196 197 static counter_u64_t free_owe_inact; 198 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, 199 "Number of times free vnodes kept on active list due to VFS " 200 "owing inactivation"); 201 202 /* To keep more than one thread at a time from running vfs_getnewfsid */ 203 static struct mtx mntid_mtx; 204 205 /* 206 * Lock for any access to the following: 207 * vnode_free_list 208 * numvnodes 209 * freevnodes 210 */ 211 static struct mtx vnode_free_list_mtx; 212 213 /* Publicly exported FS */ 214 struct nfs_public nfs_pub; 215 216 static uma_zone_t buf_trie_zone; 217 218 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 219 static uma_zone_t vnode_zone; 220 static uma_zone_t vnodepoll_zone; 221 222 /* 223 * The workitem queue. 224 * 225 * It is useful to delay writes of file data and filesystem metadata 226 * for tens of seconds so that quickly created and deleted files need 227 * not waste disk bandwidth being created and removed. To realize this, 228 * we append vnodes to a "workitem" queue. When running with a soft 229 * updates implementation, most pending metadata dependencies should 230 * not wait for more than a few seconds. Thus, mounted on block devices 231 * are delayed only about a half the time that file data is delayed. 232 * Similarly, directory updates are more critical, so are only delayed 233 * about a third the time that file data is delayed. Thus, there are 234 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 235 * one each second (driven off the filesystem syncer process). The 236 * syncer_delayno variable indicates the next queue that is to be processed. 237 * Items that need to be processed soon are placed in this queue: 238 * 239 * syncer_workitem_pending[syncer_delayno] 240 * 241 * A delay of fifteen seconds is done by placing the request fifteen 242 * entries later in the queue: 243 * 244 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 245 * 246 */ 247 static int syncer_delayno; 248 static long syncer_mask; 249 LIST_HEAD(synclist, bufobj); 250 static struct synclist *syncer_workitem_pending; 251 /* 252 * The sync_mtx protects: 253 * bo->bo_synclist 254 * sync_vnode_count 255 * syncer_delayno 256 * syncer_state 257 * syncer_workitem_pending 258 * syncer_worklist_len 259 * rushjob 260 */ 261 static struct mtx sync_mtx; 262 static struct cv sync_wakeup; 263 264 #define SYNCER_MAXDELAY 32 265 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 266 static int syncdelay = 30; /* max time to delay syncing data */ 267 static int filedelay = 30; /* time to delay syncing files */ 268 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 269 "Time to delay syncing files (in seconds)"); 270 static int dirdelay = 29; /* time to delay syncing directories */ 271 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 272 "Time to delay syncing directories (in seconds)"); 273 static int metadelay = 28; /* time to delay syncing metadata */ 274 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 275 "Time to delay syncing metadata (in seconds)"); 276 static int rushjob; /* number of slots to run ASAP */ 277 static int stat_rush_requests; /* number of times I/O speeded up */ 278 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 279 "Number of times I/O speeded up (rush requests)"); 280 281 /* 282 * When shutting down the syncer, run it at four times normal speed. 283 */ 284 #define SYNCER_SHUTDOWN_SPEEDUP 4 285 static int sync_vnode_count; 286 static int syncer_worklist_len; 287 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 288 syncer_state; 289 290 /* Target for maximum number of vnodes. */ 291 int desiredvnodes; 292 static int gapvnodes; /* gap between wanted and desired */ 293 static int vhiwat; /* enough extras after expansion */ 294 static int vlowat; /* minimal extras before expansion */ 295 static int vstir; /* nonzero to stir non-free vnodes */ 296 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 297 298 static int 299 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS) 300 { 301 int error, old_desiredvnodes; 302 303 old_desiredvnodes = desiredvnodes; 304 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0) 305 return (error); 306 if (old_desiredvnodes != desiredvnodes) { 307 wantfreevnodes = desiredvnodes / 4; 308 /* XXX locking seems to be incomplete. */ 309 vfs_hash_changesize(desiredvnodes); 310 cache_changesize(desiredvnodes); 311 } 312 return (0); 313 } 314 315 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 316 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0, 317 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes"); 318 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 319 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 320 static int vnlru_nowhere; 321 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 322 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 323 324 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 325 static int vnsz2log; 326 327 /* 328 * Support for the bufobj clean & dirty pctrie. 329 */ 330 static void * 331 buf_trie_alloc(struct pctrie *ptree) 332 { 333 334 return uma_zalloc(buf_trie_zone, M_NOWAIT); 335 } 336 337 static void 338 buf_trie_free(struct pctrie *ptree, void *node) 339 { 340 341 uma_zfree(buf_trie_zone, node); 342 } 343 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 344 345 /* 346 * Initialize the vnode management data structures. 347 * 348 * Reevaluate the following cap on the number of vnodes after the physical 349 * memory size exceeds 512GB. In the limit, as the physical memory size 350 * grows, the ratio of the memory size in KB to to vnodes approaches 64:1. 351 */ 352 #ifndef MAXVNODES_MAX 353 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */ 354 #endif 355 356 /* 357 * Initialize a vnode as it first enters the zone. 358 */ 359 static int 360 vnode_init(void *mem, int size, int flags) 361 { 362 struct vnode *vp; 363 struct bufobj *bo; 364 365 vp = mem; 366 bzero(vp, size); 367 /* 368 * Setup locks. 369 */ 370 vp->v_vnlock = &vp->v_lock; 371 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 372 /* 373 * By default, don't allow shared locks unless filesystems opt-in. 374 */ 375 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 376 LK_NOSHARE | LK_IS_VNODE); 377 /* 378 * Initialize bufobj. 379 */ 380 bo = &vp->v_bufobj; 381 rw_init(BO_LOCKPTR(bo), "bufobj interlock"); 382 bo->bo_private = vp; 383 TAILQ_INIT(&bo->bo_clean.bv_hd); 384 TAILQ_INIT(&bo->bo_dirty.bv_hd); 385 /* 386 * Initialize namecache. 387 */ 388 LIST_INIT(&vp->v_cache_src); 389 TAILQ_INIT(&vp->v_cache_dst); 390 /* 391 * Initialize rangelocks. 392 */ 393 rangelock_init(&vp->v_rl); 394 return (0); 395 } 396 397 /* 398 * Free a vnode when it is cleared from the zone. 399 */ 400 static void 401 vnode_fini(void *mem, int size) 402 { 403 struct vnode *vp; 404 struct bufobj *bo; 405 406 vp = mem; 407 rangelock_destroy(&vp->v_rl); 408 lockdestroy(vp->v_vnlock); 409 mtx_destroy(&vp->v_interlock); 410 bo = &vp->v_bufobj; 411 rw_destroy(BO_LOCKPTR(bo)); 412 } 413 414 /* 415 * Provide the size of NFS nclnode and NFS fh for calculation of the 416 * vnode memory consumption. The size is specified directly to 417 * eliminate dependency on NFS-private header. 418 * 419 * Other filesystems may use bigger or smaller (like UFS and ZFS) 420 * private inode data, but the NFS-based estimation is ample enough. 421 * Still, we care about differences in the size between 64- and 32-bit 422 * platforms. 423 * 424 * Namecache structure size is heuristically 425 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. 426 */ 427 #ifdef _LP64 428 #define NFS_NCLNODE_SZ (528 + 64) 429 #define NC_SZ 148 430 #else 431 #define NFS_NCLNODE_SZ (360 + 32) 432 #define NC_SZ 92 433 #endif 434 435 static void 436 vntblinit(void *dummy __unused) 437 { 438 u_int i; 439 int physvnodes, virtvnodes; 440 441 /* 442 * Desiredvnodes is a function of the physical memory size and the 443 * kernel's heap size. Generally speaking, it scales with the 444 * physical memory size. The ratio of desiredvnodes to the physical 445 * memory size is 1:16 until desiredvnodes exceeds 98,304. 446 * Thereafter, the 447 * marginal ratio of desiredvnodes to the physical memory size is 448 * 1:64. However, desiredvnodes is limited by the kernel's heap 449 * size. The memory required by desiredvnodes vnodes and vm objects 450 * must not exceed 1/10th of the kernel's heap size. 451 */ 452 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 453 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 454 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + 455 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); 456 desiredvnodes = min(physvnodes, virtvnodes); 457 if (desiredvnodes > MAXVNODES_MAX) { 458 if (bootverbose) 459 printf("Reducing kern.maxvnodes %d -> %d\n", 460 desiredvnodes, MAXVNODES_MAX); 461 desiredvnodes = MAXVNODES_MAX; 462 } 463 wantfreevnodes = desiredvnodes / 4; 464 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 465 TAILQ_INIT(&vnode_free_list); 466 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 467 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 468 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 469 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 470 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 471 /* 472 * Preallocate enough nodes to support one-per buf so that 473 * we can not fail an insert. reassignbuf() callers can not 474 * tolerate the insertion failure. 475 */ 476 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 477 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 478 UMA_ZONE_NOFREE | UMA_ZONE_VM); 479 uma_prealloc(buf_trie_zone, nbuf); 480 481 vnodes_created = counter_u64_alloc(M_WAITOK); 482 recycles_count = counter_u64_alloc(M_WAITOK); 483 free_owe_inact = counter_u64_alloc(M_WAITOK); 484 485 /* 486 * Initialize the filesystem syncer. 487 */ 488 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 489 &syncer_mask); 490 syncer_maxdelay = syncer_mask + 1; 491 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 492 cv_init(&sync_wakeup, "syncer"); 493 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 494 vnsz2log++; 495 vnsz2log--; 496 } 497 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 498 499 500 /* 501 * Mark a mount point as busy. Used to synchronize access and to delay 502 * unmounting. Eventually, mountlist_mtx is not released on failure. 503 * 504 * vfs_busy() is a custom lock, it can block the caller. 505 * vfs_busy() only sleeps if the unmount is active on the mount point. 506 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 507 * vnode belonging to mp. 508 * 509 * Lookup uses vfs_busy() to traverse mount points. 510 * root fs var fs 511 * / vnode lock A / vnode lock (/var) D 512 * /var vnode lock B /log vnode lock(/var/log) E 513 * vfs_busy lock C vfs_busy lock F 514 * 515 * Within each file system, the lock order is C->A->B and F->D->E. 516 * 517 * When traversing across mounts, the system follows that lock order: 518 * 519 * C->A->B 520 * | 521 * +->F->D->E 522 * 523 * The lookup() process for namei("/var") illustrates the process: 524 * VOP_LOOKUP() obtains B while A is held 525 * vfs_busy() obtains a shared lock on F while A and B are held 526 * vput() releases lock on B 527 * vput() releases lock on A 528 * VFS_ROOT() obtains lock on D while shared lock on F is held 529 * vfs_unbusy() releases shared lock on F 530 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 531 * Attempt to lock A (instead of vp_crossmp) while D is held would 532 * violate the global order, causing deadlocks. 533 * 534 * dounmount() locks B while F is drained. 535 */ 536 int 537 vfs_busy(struct mount *mp, int flags) 538 { 539 540 MPASS((flags & ~MBF_MASK) == 0); 541 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 542 543 MNT_ILOCK(mp); 544 MNT_REF(mp); 545 /* 546 * If mount point is currently being unmounted, sleep until the 547 * mount point fate is decided. If thread doing the unmounting fails, 548 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 549 * that this mount point has survived the unmount attempt and vfs_busy 550 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 551 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 552 * about to be really destroyed. vfs_busy needs to release its 553 * reference on the mount point in this case and return with ENOENT, 554 * telling the caller that mount mount it tried to busy is no longer 555 * valid. 556 */ 557 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 558 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 559 MNT_REL(mp); 560 MNT_IUNLOCK(mp); 561 CTR1(KTR_VFS, "%s: failed busying before sleeping", 562 __func__); 563 return (ENOENT); 564 } 565 if (flags & MBF_MNTLSTLOCK) 566 mtx_unlock(&mountlist_mtx); 567 mp->mnt_kern_flag |= MNTK_MWAIT; 568 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 569 if (flags & MBF_MNTLSTLOCK) 570 mtx_lock(&mountlist_mtx); 571 MNT_ILOCK(mp); 572 } 573 if (flags & MBF_MNTLSTLOCK) 574 mtx_unlock(&mountlist_mtx); 575 mp->mnt_lockref++; 576 MNT_IUNLOCK(mp); 577 return (0); 578 } 579 580 /* 581 * Free a busy filesystem. 582 */ 583 void 584 vfs_unbusy(struct mount *mp) 585 { 586 587 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 588 MNT_ILOCK(mp); 589 MNT_REL(mp); 590 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref")); 591 mp->mnt_lockref--; 592 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 593 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 594 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 595 mp->mnt_kern_flag &= ~MNTK_DRAINING; 596 wakeup(&mp->mnt_lockref); 597 } 598 MNT_IUNLOCK(mp); 599 } 600 601 /* 602 * Lookup a mount point by filesystem identifier. 603 */ 604 struct mount * 605 vfs_getvfs(fsid_t *fsid) 606 { 607 struct mount *mp; 608 609 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 610 mtx_lock(&mountlist_mtx); 611 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 612 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 613 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 614 vfs_ref(mp); 615 mtx_unlock(&mountlist_mtx); 616 return (mp); 617 } 618 } 619 mtx_unlock(&mountlist_mtx); 620 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 621 return ((struct mount *) 0); 622 } 623 624 /* 625 * Lookup a mount point by filesystem identifier, busying it before 626 * returning. 627 * 628 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 629 * cache for popular filesystem identifiers. The cache is lockess, using 630 * the fact that struct mount's are never freed. In worst case we may 631 * get pointer to unmounted or even different filesystem, so we have to 632 * check what we got, and go slow way if so. 633 */ 634 struct mount * 635 vfs_busyfs(fsid_t *fsid) 636 { 637 #define FSID_CACHE_SIZE 256 638 typedef struct mount * volatile vmp_t; 639 static vmp_t cache[FSID_CACHE_SIZE]; 640 struct mount *mp; 641 int error; 642 uint32_t hash; 643 644 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 645 hash = fsid->val[0] ^ fsid->val[1]; 646 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 647 mp = cache[hash]; 648 if (mp == NULL || 649 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 650 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 651 goto slow; 652 if (vfs_busy(mp, 0) != 0) { 653 cache[hash] = NULL; 654 goto slow; 655 } 656 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 657 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 658 return (mp); 659 else 660 vfs_unbusy(mp); 661 662 slow: 663 mtx_lock(&mountlist_mtx); 664 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 665 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 666 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 667 error = vfs_busy(mp, MBF_MNTLSTLOCK); 668 if (error) { 669 cache[hash] = NULL; 670 mtx_unlock(&mountlist_mtx); 671 return (NULL); 672 } 673 cache[hash] = mp; 674 return (mp); 675 } 676 } 677 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 678 mtx_unlock(&mountlist_mtx); 679 return ((struct mount *) 0); 680 } 681 682 /* 683 * Check if a user can access privileged mount options. 684 */ 685 int 686 vfs_suser(struct mount *mp, struct thread *td) 687 { 688 int error; 689 690 /* 691 * If the thread is jailed, but this is not a jail-friendly file 692 * system, deny immediately. 693 */ 694 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred)) 695 return (EPERM); 696 697 /* 698 * If the file system was mounted outside the jail of the calling 699 * thread, deny immediately. 700 */ 701 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 702 return (EPERM); 703 704 /* 705 * If file system supports delegated administration, we don't check 706 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 707 * by the file system itself. 708 * If this is not the user that did original mount, we check for 709 * the PRIV_VFS_MOUNT_OWNER privilege. 710 */ 711 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 712 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 713 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 714 return (error); 715 } 716 return (0); 717 } 718 719 /* 720 * Get a new unique fsid. Try to make its val[0] unique, since this value 721 * will be used to create fake device numbers for stat(). Also try (but 722 * not so hard) make its val[0] unique mod 2^16, since some emulators only 723 * support 16-bit device numbers. We end up with unique val[0]'s for the 724 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 725 * 726 * Keep in mind that several mounts may be running in parallel. Starting 727 * the search one past where the previous search terminated is both a 728 * micro-optimization and a defense against returning the same fsid to 729 * different mounts. 730 */ 731 void 732 vfs_getnewfsid(struct mount *mp) 733 { 734 static uint16_t mntid_base; 735 struct mount *nmp; 736 fsid_t tfsid; 737 int mtype; 738 739 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 740 mtx_lock(&mntid_mtx); 741 mtype = mp->mnt_vfc->vfc_typenum; 742 tfsid.val[1] = mtype; 743 mtype = (mtype & 0xFF) << 24; 744 for (;;) { 745 tfsid.val[0] = makedev(255, 746 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 747 mntid_base++; 748 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 749 break; 750 vfs_rel(nmp); 751 } 752 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 753 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 754 mtx_unlock(&mntid_mtx); 755 } 756 757 /* 758 * Knob to control the precision of file timestamps: 759 * 760 * 0 = seconds only; nanoseconds zeroed. 761 * 1 = seconds and nanoseconds, accurate within 1/HZ. 762 * 2 = seconds and nanoseconds, truncated to microseconds. 763 * >=3 = seconds and nanoseconds, maximum precision. 764 */ 765 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 766 767 static int timestamp_precision = TSP_USEC; 768 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 769 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 770 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " 771 "3+: sec + ns (max. precision))"); 772 773 /* 774 * Get a current timestamp. 775 */ 776 void 777 vfs_timestamp(struct timespec *tsp) 778 { 779 struct timeval tv; 780 781 switch (timestamp_precision) { 782 case TSP_SEC: 783 tsp->tv_sec = time_second; 784 tsp->tv_nsec = 0; 785 break; 786 case TSP_HZ: 787 getnanotime(tsp); 788 break; 789 case TSP_USEC: 790 microtime(&tv); 791 TIMEVAL_TO_TIMESPEC(&tv, tsp); 792 break; 793 case TSP_NSEC: 794 default: 795 nanotime(tsp); 796 break; 797 } 798 } 799 800 /* 801 * Set vnode attributes to VNOVAL 802 */ 803 void 804 vattr_null(struct vattr *vap) 805 { 806 807 vap->va_type = VNON; 808 vap->va_size = VNOVAL; 809 vap->va_bytes = VNOVAL; 810 vap->va_mode = VNOVAL; 811 vap->va_nlink = VNOVAL; 812 vap->va_uid = VNOVAL; 813 vap->va_gid = VNOVAL; 814 vap->va_fsid = VNOVAL; 815 vap->va_fileid = VNOVAL; 816 vap->va_blocksize = VNOVAL; 817 vap->va_rdev = VNOVAL; 818 vap->va_atime.tv_sec = VNOVAL; 819 vap->va_atime.tv_nsec = VNOVAL; 820 vap->va_mtime.tv_sec = VNOVAL; 821 vap->va_mtime.tv_nsec = VNOVAL; 822 vap->va_ctime.tv_sec = VNOVAL; 823 vap->va_ctime.tv_nsec = VNOVAL; 824 vap->va_birthtime.tv_sec = VNOVAL; 825 vap->va_birthtime.tv_nsec = VNOVAL; 826 vap->va_flags = VNOVAL; 827 vap->va_gen = VNOVAL; 828 vap->va_vaflags = 0; 829 } 830 831 /* 832 * This routine is called when we have too many vnodes. It attempts 833 * to free <count> vnodes and will potentially free vnodes that still 834 * have VM backing store (VM backing store is typically the cause 835 * of a vnode blowout so we want to do this). Therefore, this operation 836 * is not considered cheap. 837 * 838 * A number of conditions may prevent a vnode from being reclaimed. 839 * the buffer cache may have references on the vnode, a directory 840 * vnode may still have references due to the namei cache representing 841 * underlying files, or the vnode may be in active use. It is not 842 * desirable to reuse such vnodes. These conditions may cause the 843 * number of vnodes to reach some minimum value regardless of what 844 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 845 */ 846 static int 847 vlrureclaim(struct mount *mp, int reclaim_nc_src, int trigger) 848 { 849 struct vnode *vp; 850 int count, done, target; 851 852 done = 0; 853 vn_start_write(NULL, &mp, V_WAIT); 854 MNT_ILOCK(mp); 855 count = mp->mnt_nvnodelistsize; 856 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1); 857 target = target / 10 + 1; 858 while (count != 0 && done < target) { 859 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 860 while (vp != NULL && vp->v_type == VMARKER) 861 vp = TAILQ_NEXT(vp, v_nmntvnodes); 862 if (vp == NULL) 863 break; 864 /* 865 * XXX LRU is completely broken for non-free vnodes. First 866 * by calling here in mountpoint order, then by moving 867 * unselected vnodes to the end here, and most grossly by 868 * removing the vlruvp() function that was supposed to 869 * maintain the order. (This function was born broken 870 * since syncer problems prevented it doing anything.) The 871 * order is closer to LRC (C = Created). 872 * 873 * LRU reclaiming of vnodes seems to have last worked in 874 * FreeBSD-3 where LRU wasn't mentioned under any spelling. 875 * Then there was no hold count, and inactive vnodes were 876 * simply put on the free list in LRU order. The separate 877 * lists also break LRU. We prefer to reclaim from the 878 * free list for technical reasons. This tends to thrash 879 * the free list to keep very unrecently used held vnodes. 880 * The problem is mitigated by keeping the free list large. 881 */ 882 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 883 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 884 --count; 885 if (!VI_TRYLOCK(vp)) 886 goto next_iter; 887 /* 888 * If it's been deconstructed already, it's still 889 * referenced, or it exceeds the trigger, skip it. 890 * Also skip free vnodes. We are trying to make space 891 * to expand the free list, not reduce it. 892 */ 893 if (vp->v_usecount || 894 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 895 ((vp->v_iflag & VI_FREE) != 0) || 896 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 897 vp->v_object->resident_page_count > trigger)) { 898 VI_UNLOCK(vp); 899 goto next_iter; 900 } 901 MNT_IUNLOCK(mp); 902 vholdl(vp); 903 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 904 vdrop(vp); 905 goto next_iter_mntunlocked; 906 } 907 VI_LOCK(vp); 908 /* 909 * v_usecount may have been bumped after VOP_LOCK() dropped 910 * the vnode interlock and before it was locked again. 911 * 912 * It is not necessary to recheck VI_DOOMED because it can 913 * only be set by another thread that holds both the vnode 914 * lock and vnode interlock. If another thread has the 915 * vnode lock before we get to VOP_LOCK() and obtains the 916 * vnode interlock after VOP_LOCK() drops the vnode 917 * interlock, the other thread will be unable to drop the 918 * vnode lock before our VOP_LOCK() call fails. 919 */ 920 if (vp->v_usecount || 921 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 922 (vp->v_iflag & VI_FREE) != 0 || 923 (vp->v_object != NULL && 924 vp->v_object->resident_page_count > trigger)) { 925 VOP_UNLOCK(vp, LK_INTERLOCK); 926 vdrop(vp); 927 goto next_iter_mntunlocked; 928 } 929 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 930 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 931 counter_u64_add(recycles_count, 1); 932 vgonel(vp); 933 VOP_UNLOCK(vp, 0); 934 vdropl(vp); 935 done++; 936 next_iter_mntunlocked: 937 if (!should_yield()) 938 goto relock_mnt; 939 goto yield; 940 next_iter: 941 if (!should_yield()) 942 continue; 943 MNT_IUNLOCK(mp); 944 yield: 945 kern_yield(PRI_USER); 946 relock_mnt: 947 MNT_ILOCK(mp); 948 } 949 MNT_IUNLOCK(mp); 950 vn_finished_write(mp); 951 return done; 952 } 953 954 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ 955 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, 956 0, 957 "limit on vnode free requests per call to the vnlru_free routine"); 958 959 /* 960 * Attempt to reduce the free list by the requested amount. 961 */ 962 static void 963 vnlru_free_locked(int count, struct vfsops *mnt_op) 964 { 965 struct vnode *vp; 966 struct mount *mp; 967 bool tried_batches; 968 969 tried_batches = false; 970 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 971 if (count > max_vnlru_free) 972 count = max_vnlru_free; 973 for (; count > 0; count--) { 974 vp = TAILQ_FIRST(&vnode_free_list); 975 /* 976 * The list can be modified while the free_list_mtx 977 * has been dropped and vp could be NULL here. 978 */ 979 if (vp == NULL) { 980 if (tried_batches) 981 break; 982 mtx_unlock(&vnode_free_list_mtx); 983 vnlru_return_batches(mnt_op); 984 tried_batches = true; 985 mtx_lock(&vnode_free_list_mtx); 986 continue; 987 } 988 989 VNASSERT(vp->v_op != NULL, vp, 990 ("vnlru_free: vnode already reclaimed.")); 991 KASSERT((vp->v_iflag & VI_FREE) != 0, 992 ("Removing vnode not on freelist")); 993 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 994 ("Mangling active vnode")); 995 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 996 997 /* 998 * Don't recycle if our vnode is from different type 999 * of mount point. Note that mp is type-safe, the 1000 * check does not reach unmapped address even if 1001 * vnode is reclaimed. 1002 * Don't recycle if we can't get the interlock without 1003 * blocking. 1004 */ 1005 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL && 1006 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { 1007 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist); 1008 continue; 1009 } 1010 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0, 1011 vp, ("vp inconsistent on freelist")); 1012 1013 /* 1014 * The clear of VI_FREE prevents activation of the 1015 * vnode. There is no sense in putting the vnode on 1016 * the mount point active list, only to remove it 1017 * later during recycling. Inline the relevant part 1018 * of vholdl(), to avoid triggering assertions or 1019 * activating. 1020 */ 1021 freevnodes--; 1022 vp->v_iflag &= ~VI_FREE; 1023 refcount_acquire(&vp->v_holdcnt); 1024 1025 mtx_unlock(&vnode_free_list_mtx); 1026 VI_UNLOCK(vp); 1027 vtryrecycle(vp); 1028 /* 1029 * If the recycled succeeded this vdrop will actually free 1030 * the vnode. If not it will simply place it back on 1031 * the free list. 1032 */ 1033 vdrop(vp); 1034 mtx_lock(&vnode_free_list_mtx); 1035 } 1036 } 1037 1038 void 1039 vnlru_free(int count, struct vfsops *mnt_op) 1040 { 1041 1042 mtx_lock(&vnode_free_list_mtx); 1043 vnlru_free_locked(count, mnt_op); 1044 mtx_unlock(&vnode_free_list_mtx); 1045 } 1046 1047 1048 /* XXX some names and initialization are bad for limits and watermarks. */ 1049 static int 1050 vspace(void) 1051 { 1052 int space; 1053 1054 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 1055 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 1056 vlowat = vhiwat / 2; 1057 if (numvnodes > desiredvnodes) 1058 return (0); 1059 space = desiredvnodes - numvnodes; 1060 if (freevnodes > wantfreevnodes) 1061 space += freevnodes - wantfreevnodes; 1062 return (space); 1063 } 1064 1065 static void 1066 vnlru_return_batch_locked(struct mount *mp) 1067 { 1068 struct vnode *vp; 1069 1070 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 1071 1072 if (mp->mnt_tmpfreevnodelistsize == 0) 1073 return; 1074 1075 TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) { 1076 VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp, 1077 ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist")); 1078 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 1079 } 1080 mtx_lock(&vnode_free_list_mtx); 1081 TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist); 1082 freevnodes += mp->mnt_tmpfreevnodelistsize; 1083 mtx_unlock(&vnode_free_list_mtx); 1084 mp->mnt_tmpfreevnodelistsize = 0; 1085 } 1086 1087 static void 1088 vnlru_return_batch(struct mount *mp) 1089 { 1090 1091 mtx_lock(&mp->mnt_listmtx); 1092 vnlru_return_batch_locked(mp); 1093 mtx_unlock(&mp->mnt_listmtx); 1094 } 1095 1096 static void 1097 vnlru_return_batches(struct vfsops *mnt_op) 1098 { 1099 struct mount *mp, *nmp; 1100 bool need_unbusy; 1101 1102 mtx_lock(&mountlist_mtx); 1103 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1104 need_unbusy = false; 1105 if (mnt_op != NULL && mp->mnt_op != mnt_op) 1106 goto next; 1107 if (mp->mnt_tmpfreevnodelistsize == 0) 1108 goto next; 1109 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) { 1110 vnlru_return_batch(mp); 1111 need_unbusy = true; 1112 mtx_lock(&mountlist_mtx); 1113 } 1114 next: 1115 nmp = TAILQ_NEXT(mp, mnt_list); 1116 if (need_unbusy) 1117 vfs_unbusy(mp); 1118 } 1119 mtx_unlock(&mountlist_mtx); 1120 } 1121 1122 /* 1123 * Attempt to recycle vnodes in a context that is always safe to block. 1124 * Calling vlrurecycle() from the bowels of filesystem code has some 1125 * interesting deadlock problems. 1126 */ 1127 static struct proc *vnlruproc; 1128 static int vnlruproc_sig; 1129 1130 static void 1131 vnlru_proc(void) 1132 { 1133 struct mount *mp, *nmp; 1134 unsigned long ofreevnodes, onumvnodes; 1135 int done, force, reclaim_nc_src, trigger, usevnodes; 1136 1137 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1138 SHUTDOWN_PRI_FIRST); 1139 1140 force = 0; 1141 for (;;) { 1142 kproc_suspend_check(vnlruproc); 1143 mtx_lock(&vnode_free_list_mtx); 1144 /* 1145 * If numvnodes is too large (due to desiredvnodes being 1146 * adjusted using its sysctl, or emergency growth), first 1147 * try to reduce it by discarding from the free list. 1148 */ 1149 if (numvnodes > desiredvnodes) 1150 vnlru_free_locked(numvnodes - desiredvnodes, NULL); 1151 /* 1152 * Sleep if the vnode cache is in a good state. This is 1153 * when it is not over-full and has space for about a 4% 1154 * or 9% expansion (by growing its size or inexcessively 1155 * reducing its free list). Otherwise, try to reclaim 1156 * space for a 10% expansion. 1157 */ 1158 if (vstir && force == 0) { 1159 force = 1; 1160 vstir = 0; 1161 } 1162 if (vspace() >= vlowat && force == 0) { 1163 vnlruproc_sig = 0; 1164 wakeup(&vnlruproc_sig); 1165 msleep(vnlruproc, &vnode_free_list_mtx, 1166 PVFS|PDROP, "vlruwt", hz); 1167 continue; 1168 } 1169 mtx_unlock(&vnode_free_list_mtx); 1170 done = 0; 1171 ofreevnodes = freevnodes; 1172 onumvnodes = numvnodes; 1173 /* 1174 * Calculate parameters for recycling. These are the same 1175 * throughout the loop to give some semblance of fairness. 1176 * The trigger point is to avoid recycling vnodes with lots 1177 * of resident pages. We aren't trying to free memory; we 1178 * are trying to recycle or at least free vnodes. 1179 */ 1180 if (numvnodes <= desiredvnodes) 1181 usevnodes = numvnodes - freevnodes; 1182 else 1183 usevnodes = numvnodes; 1184 if (usevnodes <= 0) 1185 usevnodes = 1; 1186 /* 1187 * The trigger value is is chosen to give a conservatively 1188 * large value to ensure that it alone doesn't prevent 1189 * making progress. The value can easily be so large that 1190 * it is effectively infinite in some congested and 1191 * misconfigured cases, and this is necessary. Normally 1192 * it is about 8 to 100 (pages), which is quite large. 1193 */ 1194 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1195 if (force < 2) 1196 trigger = vsmalltrigger; 1197 reclaim_nc_src = force >= 3; 1198 mtx_lock(&mountlist_mtx); 1199 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1200 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { 1201 nmp = TAILQ_NEXT(mp, mnt_list); 1202 continue; 1203 } 1204 done += vlrureclaim(mp, reclaim_nc_src, trigger); 1205 mtx_lock(&mountlist_mtx); 1206 nmp = TAILQ_NEXT(mp, mnt_list); 1207 vfs_unbusy(mp); 1208 } 1209 mtx_unlock(&mountlist_mtx); 1210 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1211 uma_reclaim(); 1212 if (done == 0) { 1213 if (force == 0 || force == 1) { 1214 force = 2; 1215 continue; 1216 } 1217 if (force == 2) { 1218 force = 3; 1219 continue; 1220 } 1221 force = 0; 1222 vnlru_nowhere++; 1223 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1224 } else 1225 kern_yield(PRI_USER); 1226 /* 1227 * After becoming active to expand above low water, keep 1228 * active until above high water. 1229 */ 1230 force = vspace() < vhiwat; 1231 } 1232 } 1233 1234 static struct kproc_desc vnlru_kp = { 1235 "vnlru", 1236 vnlru_proc, 1237 &vnlruproc 1238 }; 1239 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1240 &vnlru_kp); 1241 1242 /* 1243 * Routines having to do with the management of the vnode table. 1244 */ 1245 1246 /* 1247 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1248 * before we actually vgone(). This function must be called with the vnode 1249 * held to prevent the vnode from being returned to the free list midway 1250 * through vgone(). 1251 */ 1252 static int 1253 vtryrecycle(struct vnode *vp) 1254 { 1255 struct mount *vnmp; 1256 1257 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1258 VNASSERT(vp->v_holdcnt, vp, 1259 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1260 /* 1261 * This vnode may found and locked via some other list, if so we 1262 * can't recycle it yet. 1263 */ 1264 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1265 CTR2(KTR_VFS, 1266 "%s: impossible to recycle, vp %p lock is already held", 1267 __func__, vp); 1268 return (EWOULDBLOCK); 1269 } 1270 /* 1271 * Don't recycle if its filesystem is being suspended. 1272 */ 1273 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1274 VOP_UNLOCK(vp, 0); 1275 CTR2(KTR_VFS, 1276 "%s: impossible to recycle, cannot start the write for %p", 1277 __func__, vp); 1278 return (EBUSY); 1279 } 1280 /* 1281 * If we got this far, we need to acquire the interlock and see if 1282 * anyone picked up this vnode from another list. If not, we will 1283 * mark it with DOOMED via vgonel() so that anyone who does find it 1284 * will skip over it. 1285 */ 1286 VI_LOCK(vp); 1287 if (vp->v_usecount) { 1288 VOP_UNLOCK(vp, LK_INTERLOCK); 1289 vn_finished_write(vnmp); 1290 CTR2(KTR_VFS, 1291 "%s: impossible to recycle, %p is already referenced", 1292 __func__, vp); 1293 return (EBUSY); 1294 } 1295 if ((vp->v_iflag & VI_DOOMED) == 0) { 1296 counter_u64_add(recycles_count, 1); 1297 vgonel(vp); 1298 } 1299 VOP_UNLOCK(vp, LK_INTERLOCK); 1300 vn_finished_write(vnmp); 1301 return (0); 1302 } 1303 1304 static void 1305 vcheckspace(void) 1306 { 1307 1308 if (vspace() < vlowat && vnlruproc_sig == 0) { 1309 vnlruproc_sig = 1; 1310 wakeup(vnlruproc); 1311 } 1312 } 1313 1314 /* 1315 * Wait if necessary for space for a new vnode. 1316 */ 1317 static int 1318 getnewvnode_wait(int suspended) 1319 { 1320 1321 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1322 if (numvnodes >= desiredvnodes) { 1323 if (suspended) { 1324 /* 1325 * The file system is being suspended. We cannot 1326 * risk a deadlock here, so allow allocation of 1327 * another vnode even if this would give too many. 1328 */ 1329 return (0); 1330 } 1331 if (vnlruproc_sig == 0) { 1332 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 1333 wakeup(vnlruproc); 1334 } 1335 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 1336 "vlruwk", hz); 1337 } 1338 /* Post-adjust like the pre-adjust in getnewvnode(). */ 1339 if (numvnodes + 1 > desiredvnodes && freevnodes > 1) 1340 vnlru_free_locked(1, NULL); 1341 return (numvnodes >= desiredvnodes ? ENFILE : 0); 1342 } 1343 1344 /* 1345 * This hack is fragile, and probably not needed any more now that the 1346 * watermark handling works. 1347 */ 1348 void 1349 getnewvnode_reserve(u_int count) 1350 { 1351 struct thread *td; 1352 1353 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */ 1354 /* XXX no longer so quick, but this part is not racy. */ 1355 mtx_lock(&vnode_free_list_mtx); 1356 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes) 1357 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes, 1358 freevnodes - wantfreevnodes), NULL); 1359 mtx_unlock(&vnode_free_list_mtx); 1360 1361 td = curthread; 1362 /* First try to be quick and racy. */ 1363 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) { 1364 td->td_vp_reserv += count; 1365 vcheckspace(); /* XXX no longer so quick, but more racy */ 1366 return; 1367 } else 1368 atomic_subtract_long(&numvnodes, count); 1369 1370 mtx_lock(&vnode_free_list_mtx); 1371 while (count > 0) { 1372 if (getnewvnode_wait(0) == 0) { 1373 count--; 1374 td->td_vp_reserv++; 1375 atomic_add_long(&numvnodes, 1); 1376 } 1377 } 1378 vcheckspace(); 1379 mtx_unlock(&vnode_free_list_mtx); 1380 } 1381 1382 /* 1383 * This hack is fragile, especially if desiredvnodes or wantvnodes are 1384 * misconfgured or changed significantly. Reducing desiredvnodes below 1385 * the reserved amount should cause bizarre behaviour like reducing it 1386 * below the number of active vnodes -- the system will try to reduce 1387 * numvnodes to match, but should fail, so the subtraction below should 1388 * not overflow. 1389 */ 1390 void 1391 getnewvnode_drop_reserve(void) 1392 { 1393 struct thread *td; 1394 1395 td = curthread; 1396 atomic_subtract_long(&numvnodes, td->td_vp_reserv); 1397 td->td_vp_reserv = 0; 1398 } 1399 1400 /* 1401 * Return the next vnode from the free list. 1402 */ 1403 int 1404 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1405 struct vnode **vpp) 1406 { 1407 struct vnode *vp; 1408 struct thread *td; 1409 struct lock_object *lo; 1410 static int cyclecount; 1411 int error; 1412 1413 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1414 vp = NULL; 1415 td = curthread; 1416 if (td->td_vp_reserv > 0) { 1417 td->td_vp_reserv -= 1; 1418 goto alloc; 1419 } 1420 mtx_lock(&vnode_free_list_mtx); 1421 if (numvnodes < desiredvnodes) 1422 cyclecount = 0; 1423 else if (cyclecount++ >= freevnodes) { 1424 cyclecount = 0; 1425 vstir = 1; 1426 } 1427 /* 1428 * Grow the vnode cache if it will not be above its target max 1429 * after growing. Otherwise, if the free list is nonempty, try 1430 * to reclaim 1 item from it before growing the cache (possibly 1431 * above its target max if the reclamation failed or is delayed). 1432 * Otherwise, wait for some space. In all cases, schedule 1433 * vnlru_proc() if we are getting short of space. The watermarks 1434 * should be chosen so that we never wait or even reclaim from 1435 * the free list to below its target minimum. 1436 */ 1437 if (numvnodes + 1 <= desiredvnodes) 1438 ; 1439 else if (freevnodes > 0) 1440 vnlru_free_locked(1, NULL); 1441 else { 1442 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag & 1443 MNTK_SUSPEND)); 1444 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 1445 if (error != 0) { 1446 mtx_unlock(&vnode_free_list_mtx); 1447 return (error); 1448 } 1449 #endif 1450 } 1451 vcheckspace(); 1452 atomic_add_long(&numvnodes, 1); 1453 mtx_unlock(&vnode_free_list_mtx); 1454 alloc: 1455 counter_u64_add(vnodes_created, 1); 1456 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 1457 /* 1458 * Locks are given the generic name "vnode" when created. 1459 * Follow the historic practice of using the filesystem 1460 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1461 * 1462 * Locks live in a witness group keyed on their name. Thus, 1463 * when a lock is renamed, it must also move from the witness 1464 * group of its old name to the witness group of its new name. 1465 * 1466 * The change only needs to be made when the vnode moves 1467 * from one filesystem type to another. We ensure that each 1468 * filesystem use a single static name pointer for its tag so 1469 * that we can compare pointers rather than doing a strcmp(). 1470 */ 1471 lo = &vp->v_vnlock->lock_object; 1472 if (lo->lo_name != tag) { 1473 lo->lo_name = tag; 1474 WITNESS_DESTROY(lo); 1475 WITNESS_INIT(lo, tag); 1476 } 1477 /* 1478 * By default, don't allow shared locks unless filesystems opt-in. 1479 */ 1480 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1481 /* 1482 * Finalize various vnode identity bits. 1483 */ 1484 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1485 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1486 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1487 vp->v_type = VNON; 1488 vp->v_tag = tag; 1489 vp->v_op = vops; 1490 v_init_counters(vp); 1491 vp->v_bufobj.bo_ops = &buf_ops_bio; 1492 #ifdef DIAGNOSTIC 1493 if (mp == NULL && vops != &dead_vnodeops) 1494 printf("NULL mp in getnewvnode(9), tag %s\n", tag); 1495 #endif 1496 #ifdef MAC 1497 mac_vnode_init(vp); 1498 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1499 mac_vnode_associate_singlelabel(mp, vp); 1500 #endif 1501 if (mp != NULL) { 1502 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1503 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1504 vp->v_vflag |= VV_NOKNOTE; 1505 } 1506 1507 /* 1508 * For the filesystems which do not use vfs_hash_insert(), 1509 * still initialize v_hash to have vfs_hash_index() useful. 1510 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1511 * its own hashing. 1512 */ 1513 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1514 1515 *vpp = vp; 1516 return (0); 1517 } 1518 1519 /* 1520 * Delete from old mount point vnode list, if on one. 1521 */ 1522 static void 1523 delmntque(struct vnode *vp) 1524 { 1525 struct mount *mp; 1526 int active; 1527 1528 mp = vp->v_mount; 1529 if (mp == NULL) 1530 return; 1531 MNT_ILOCK(mp); 1532 VI_LOCK(vp); 1533 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize, 1534 ("Active vnode list size %d > Vnode list size %d", 1535 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize)); 1536 active = vp->v_iflag & VI_ACTIVE; 1537 vp->v_iflag &= ~VI_ACTIVE; 1538 if (active) { 1539 mtx_lock(&mp->mnt_listmtx); 1540 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); 1541 mp->mnt_activevnodelistsize--; 1542 mtx_unlock(&mp->mnt_listmtx); 1543 } 1544 vp->v_mount = NULL; 1545 VI_UNLOCK(vp); 1546 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1547 ("bad mount point vnode list size")); 1548 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1549 mp->mnt_nvnodelistsize--; 1550 MNT_REL(mp); 1551 MNT_IUNLOCK(mp); 1552 } 1553 1554 static void 1555 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1556 { 1557 1558 vp->v_data = NULL; 1559 vp->v_op = &dead_vnodeops; 1560 vgone(vp); 1561 vput(vp); 1562 } 1563 1564 /* 1565 * Insert into list of vnodes for the new mount point, if available. 1566 */ 1567 int 1568 insmntque1(struct vnode *vp, struct mount *mp, 1569 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1570 { 1571 1572 KASSERT(vp->v_mount == NULL, 1573 ("insmntque: vnode already on per mount vnode list")); 1574 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1575 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1576 1577 /* 1578 * We acquire the vnode interlock early to ensure that the 1579 * vnode cannot be recycled by another process releasing a 1580 * holdcnt on it before we get it on both the vnode list 1581 * and the active vnode list. The mount mutex protects only 1582 * manipulation of the vnode list and the vnode freelist 1583 * mutex protects only manipulation of the active vnode list. 1584 * Hence the need to hold the vnode interlock throughout. 1585 */ 1586 MNT_ILOCK(mp); 1587 VI_LOCK(vp); 1588 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1589 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1590 mp->mnt_nvnodelistsize == 0)) && 1591 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1592 VI_UNLOCK(vp); 1593 MNT_IUNLOCK(mp); 1594 if (dtr != NULL) 1595 dtr(vp, dtr_arg); 1596 return (EBUSY); 1597 } 1598 vp->v_mount = mp; 1599 MNT_REF(mp); 1600 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1601 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1602 ("neg mount point vnode list size")); 1603 mp->mnt_nvnodelistsize++; 1604 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1605 ("Activating already active vnode")); 1606 vp->v_iflag |= VI_ACTIVE; 1607 mtx_lock(&mp->mnt_listmtx); 1608 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 1609 mp->mnt_activevnodelistsize++; 1610 mtx_unlock(&mp->mnt_listmtx); 1611 VI_UNLOCK(vp); 1612 MNT_IUNLOCK(mp); 1613 return (0); 1614 } 1615 1616 int 1617 insmntque(struct vnode *vp, struct mount *mp) 1618 { 1619 1620 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1621 } 1622 1623 /* 1624 * Flush out and invalidate all buffers associated with a bufobj 1625 * Called with the underlying object locked. 1626 */ 1627 int 1628 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1629 { 1630 int error; 1631 1632 BO_LOCK(bo); 1633 if (flags & V_SAVE) { 1634 error = bufobj_wwait(bo, slpflag, slptimeo); 1635 if (error) { 1636 BO_UNLOCK(bo); 1637 return (error); 1638 } 1639 if (bo->bo_dirty.bv_cnt > 0) { 1640 BO_UNLOCK(bo); 1641 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1642 return (error); 1643 /* 1644 * XXX We could save a lock/unlock if this was only 1645 * enabled under INVARIANTS 1646 */ 1647 BO_LOCK(bo); 1648 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1649 panic("vinvalbuf: dirty bufs"); 1650 } 1651 } 1652 /* 1653 * If you alter this loop please notice that interlock is dropped and 1654 * reacquired in flushbuflist. Special care is needed to ensure that 1655 * no race conditions occur from this. 1656 */ 1657 do { 1658 error = flushbuflist(&bo->bo_clean, 1659 flags, bo, slpflag, slptimeo); 1660 if (error == 0 && !(flags & V_CLEANONLY)) 1661 error = flushbuflist(&bo->bo_dirty, 1662 flags, bo, slpflag, slptimeo); 1663 if (error != 0 && error != EAGAIN) { 1664 BO_UNLOCK(bo); 1665 return (error); 1666 } 1667 } while (error != 0); 1668 1669 /* 1670 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1671 * have write I/O in-progress but if there is a VM object then the 1672 * VM object can also have read-I/O in-progress. 1673 */ 1674 do { 1675 bufobj_wwait(bo, 0, 0); 1676 if ((flags & V_VMIO) == 0) { 1677 BO_UNLOCK(bo); 1678 if (bo->bo_object != NULL) { 1679 VM_OBJECT_WLOCK(bo->bo_object); 1680 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1681 VM_OBJECT_WUNLOCK(bo->bo_object); 1682 } 1683 BO_LOCK(bo); 1684 } 1685 } while (bo->bo_numoutput > 0); 1686 BO_UNLOCK(bo); 1687 1688 /* 1689 * Destroy the copy in the VM cache, too. 1690 */ 1691 if (bo->bo_object != NULL && 1692 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { 1693 VM_OBJECT_WLOCK(bo->bo_object); 1694 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1695 OBJPR_CLEANONLY : 0); 1696 VM_OBJECT_WUNLOCK(bo->bo_object); 1697 } 1698 1699 #ifdef INVARIANTS 1700 BO_LOCK(bo); 1701 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | 1702 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || 1703 bo->bo_clean.bv_cnt > 0)) 1704 panic("vinvalbuf: flush failed"); 1705 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && 1706 bo->bo_dirty.bv_cnt > 0) 1707 panic("vinvalbuf: flush dirty failed"); 1708 BO_UNLOCK(bo); 1709 #endif 1710 return (0); 1711 } 1712 1713 /* 1714 * Flush out and invalidate all buffers associated with a vnode. 1715 * Called with the underlying object locked. 1716 */ 1717 int 1718 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1719 { 1720 1721 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1722 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1723 if (vp->v_object != NULL && vp->v_object->handle != vp) 1724 return (0); 1725 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1726 } 1727 1728 /* 1729 * Flush out buffers on the specified list. 1730 * 1731 */ 1732 static int 1733 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1734 int slptimeo) 1735 { 1736 struct buf *bp, *nbp; 1737 int retval, error; 1738 daddr_t lblkno; 1739 b_xflags_t xflags; 1740 1741 ASSERT_BO_WLOCKED(bo); 1742 1743 retval = 0; 1744 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1745 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1746 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1747 continue; 1748 } 1749 lblkno = 0; 1750 xflags = 0; 1751 if (nbp != NULL) { 1752 lblkno = nbp->b_lblkno; 1753 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1754 } 1755 retval = EAGAIN; 1756 error = BUF_TIMELOCK(bp, 1757 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1758 "flushbuf", slpflag, slptimeo); 1759 if (error) { 1760 BO_LOCK(bo); 1761 return (error != ENOLCK ? error : EAGAIN); 1762 } 1763 KASSERT(bp->b_bufobj == bo, 1764 ("bp %p wrong b_bufobj %p should be %p", 1765 bp, bp->b_bufobj, bo)); 1766 /* 1767 * XXX Since there are no node locks for NFS, I 1768 * believe there is a slight chance that a delayed 1769 * write will occur while sleeping just above, so 1770 * check for it. 1771 */ 1772 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1773 (flags & V_SAVE)) { 1774 bremfree(bp); 1775 bp->b_flags |= B_ASYNC; 1776 bwrite(bp); 1777 BO_LOCK(bo); 1778 return (EAGAIN); /* XXX: why not loop ? */ 1779 } 1780 bremfree(bp); 1781 bp->b_flags |= (B_INVAL | B_RELBUF); 1782 bp->b_flags &= ~B_ASYNC; 1783 brelse(bp); 1784 BO_LOCK(bo); 1785 nbp = gbincore(bo, lblkno); 1786 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1787 != xflags) 1788 break; /* nbp invalid */ 1789 } 1790 return (retval); 1791 } 1792 1793 int 1794 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 1795 { 1796 struct buf *bp; 1797 int error; 1798 daddr_t lblkno; 1799 1800 ASSERT_BO_LOCKED(bo); 1801 1802 for (lblkno = startn;;) { 1803 again: 1804 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 1805 if (bp == NULL || bp->b_lblkno >= endn || 1806 bp->b_lblkno < startn) 1807 break; 1808 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 1809 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 1810 if (error != 0) { 1811 BO_RLOCK(bo); 1812 if (error == ENOLCK) 1813 goto again; 1814 return (error); 1815 } 1816 KASSERT(bp->b_bufobj == bo, 1817 ("bp %p wrong b_bufobj %p should be %p", 1818 bp, bp->b_bufobj, bo)); 1819 lblkno = bp->b_lblkno + 1; 1820 if ((bp->b_flags & B_MANAGED) == 0) 1821 bremfree(bp); 1822 bp->b_flags |= B_RELBUF; 1823 /* 1824 * In the VMIO case, use the B_NOREUSE flag to hint that the 1825 * pages backing each buffer in the range are unlikely to be 1826 * reused. Dirty buffers will have the hint applied once 1827 * they've been written. 1828 */ 1829 if (bp->b_vp->v_object != NULL) 1830 bp->b_flags |= B_NOREUSE; 1831 brelse(bp); 1832 BO_RLOCK(bo); 1833 } 1834 return (0); 1835 } 1836 1837 /* 1838 * Truncate a file's buffer and pages to a specified length. This 1839 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1840 * sync activity. 1841 */ 1842 int 1843 vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize) 1844 { 1845 struct buf *bp, *nbp; 1846 int anyfreed; 1847 int trunclbn; 1848 struct bufobj *bo; 1849 1850 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__, 1851 vp, cred, blksize, (uintmax_t)length); 1852 1853 /* 1854 * Round up to the *next* lbn. 1855 */ 1856 trunclbn = howmany(length, blksize); 1857 1858 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1859 restart: 1860 bo = &vp->v_bufobj; 1861 BO_LOCK(bo); 1862 anyfreed = 1; 1863 for (;anyfreed;) { 1864 anyfreed = 0; 1865 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1866 if (bp->b_lblkno < trunclbn) 1867 continue; 1868 if (BUF_LOCK(bp, 1869 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1870 BO_LOCKPTR(bo)) == ENOLCK) 1871 goto restart; 1872 1873 bremfree(bp); 1874 bp->b_flags |= (B_INVAL | B_RELBUF); 1875 bp->b_flags &= ~B_ASYNC; 1876 brelse(bp); 1877 anyfreed = 1; 1878 1879 BO_LOCK(bo); 1880 if (nbp != NULL && 1881 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1882 (nbp->b_vp != vp) || 1883 (nbp->b_flags & B_DELWRI))) { 1884 BO_UNLOCK(bo); 1885 goto restart; 1886 } 1887 } 1888 1889 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1890 if (bp->b_lblkno < trunclbn) 1891 continue; 1892 if (BUF_LOCK(bp, 1893 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1894 BO_LOCKPTR(bo)) == ENOLCK) 1895 goto restart; 1896 bremfree(bp); 1897 bp->b_flags |= (B_INVAL | B_RELBUF); 1898 bp->b_flags &= ~B_ASYNC; 1899 brelse(bp); 1900 anyfreed = 1; 1901 1902 BO_LOCK(bo); 1903 if (nbp != NULL && 1904 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1905 (nbp->b_vp != vp) || 1906 (nbp->b_flags & B_DELWRI) == 0)) { 1907 BO_UNLOCK(bo); 1908 goto restart; 1909 } 1910 } 1911 } 1912 1913 if (length > 0) { 1914 restartsync: 1915 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1916 if (bp->b_lblkno > 0) 1917 continue; 1918 /* 1919 * Since we hold the vnode lock this should only 1920 * fail if we're racing with the buf daemon. 1921 */ 1922 if (BUF_LOCK(bp, 1923 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1924 BO_LOCKPTR(bo)) == ENOLCK) { 1925 goto restart; 1926 } 1927 VNASSERT((bp->b_flags & B_DELWRI), vp, 1928 ("buf(%p) on dirty queue without DELWRI", bp)); 1929 1930 bremfree(bp); 1931 bawrite(bp); 1932 BO_LOCK(bo); 1933 goto restartsync; 1934 } 1935 } 1936 1937 bufobj_wwait(bo, 0, 0); 1938 BO_UNLOCK(bo); 1939 vnode_pager_setsize(vp, length); 1940 1941 return (0); 1942 } 1943 1944 static void 1945 buf_vlist_remove(struct buf *bp) 1946 { 1947 struct bufv *bv; 1948 1949 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1950 ASSERT_BO_WLOCKED(bp->b_bufobj); 1951 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1952 (BX_VNDIRTY|BX_VNCLEAN), 1953 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1954 if (bp->b_xflags & BX_VNDIRTY) 1955 bv = &bp->b_bufobj->bo_dirty; 1956 else 1957 bv = &bp->b_bufobj->bo_clean; 1958 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 1959 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1960 bv->bv_cnt--; 1961 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1962 } 1963 1964 /* 1965 * Add the buffer to the sorted clean or dirty block list. 1966 * 1967 * NOTE: xflags is passed as a constant, optimizing this inline function! 1968 */ 1969 static void 1970 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1971 { 1972 struct bufv *bv; 1973 struct buf *n; 1974 int error; 1975 1976 ASSERT_BO_WLOCKED(bo); 1977 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 1978 ("dead bo %p", bo)); 1979 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1980 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1981 bp->b_xflags |= xflags; 1982 if (xflags & BX_VNDIRTY) 1983 bv = &bo->bo_dirty; 1984 else 1985 bv = &bo->bo_clean; 1986 1987 /* 1988 * Keep the list ordered. Optimize empty list insertion. Assume 1989 * we tend to grow at the tail so lookup_le should usually be cheaper 1990 * than _ge. 1991 */ 1992 if (bv->bv_cnt == 0 || 1993 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 1994 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1995 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 1996 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 1997 else 1998 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 1999 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 2000 if (error) 2001 panic("buf_vlist_add: Preallocated nodes insufficient."); 2002 bv->bv_cnt++; 2003 } 2004 2005 /* 2006 * Look up a buffer using the buffer tries. 2007 */ 2008 struct buf * 2009 gbincore(struct bufobj *bo, daddr_t lblkno) 2010 { 2011 struct buf *bp; 2012 2013 ASSERT_BO_LOCKED(bo); 2014 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2015 if (bp != NULL) 2016 return (bp); 2017 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2018 } 2019 2020 /* 2021 * Associate a buffer with a vnode. 2022 */ 2023 void 2024 bgetvp(struct vnode *vp, struct buf *bp) 2025 { 2026 struct bufobj *bo; 2027 2028 bo = &vp->v_bufobj; 2029 ASSERT_BO_WLOCKED(bo); 2030 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2031 2032 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2033 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2034 ("bgetvp: bp already attached! %p", bp)); 2035 2036 vhold(vp); 2037 bp->b_vp = vp; 2038 bp->b_bufobj = bo; 2039 /* 2040 * Insert onto list for new vnode. 2041 */ 2042 buf_vlist_add(bp, bo, BX_VNCLEAN); 2043 } 2044 2045 /* 2046 * Disassociate a buffer from a vnode. 2047 */ 2048 void 2049 brelvp(struct buf *bp) 2050 { 2051 struct bufobj *bo; 2052 struct vnode *vp; 2053 2054 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2055 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2056 2057 /* 2058 * Delete from old vnode list, if on one. 2059 */ 2060 vp = bp->b_vp; /* XXX */ 2061 bo = bp->b_bufobj; 2062 BO_LOCK(bo); 2063 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2064 buf_vlist_remove(bp); 2065 else 2066 panic("brelvp: Buffer %p not on queue.", bp); 2067 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2068 bo->bo_flag &= ~BO_ONWORKLST; 2069 mtx_lock(&sync_mtx); 2070 LIST_REMOVE(bo, bo_synclist); 2071 syncer_worklist_len--; 2072 mtx_unlock(&sync_mtx); 2073 } 2074 bp->b_vp = NULL; 2075 bp->b_bufobj = NULL; 2076 BO_UNLOCK(bo); 2077 vdrop(vp); 2078 } 2079 2080 /* 2081 * Add an item to the syncer work queue. 2082 */ 2083 static void 2084 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2085 { 2086 int slot; 2087 2088 ASSERT_BO_WLOCKED(bo); 2089 2090 mtx_lock(&sync_mtx); 2091 if (bo->bo_flag & BO_ONWORKLST) 2092 LIST_REMOVE(bo, bo_synclist); 2093 else { 2094 bo->bo_flag |= BO_ONWORKLST; 2095 syncer_worklist_len++; 2096 } 2097 2098 if (delay > syncer_maxdelay - 2) 2099 delay = syncer_maxdelay - 2; 2100 slot = (syncer_delayno + delay) & syncer_mask; 2101 2102 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2103 mtx_unlock(&sync_mtx); 2104 } 2105 2106 static int 2107 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2108 { 2109 int error, len; 2110 2111 mtx_lock(&sync_mtx); 2112 len = syncer_worklist_len - sync_vnode_count; 2113 mtx_unlock(&sync_mtx); 2114 error = SYSCTL_OUT(req, &len, sizeof(len)); 2115 return (error); 2116 } 2117 2118 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 2119 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2120 2121 static struct proc *updateproc; 2122 static void sched_sync(void); 2123 static struct kproc_desc up_kp = { 2124 "syncer", 2125 sched_sync, 2126 &updateproc 2127 }; 2128 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2129 2130 static int 2131 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2132 { 2133 struct vnode *vp; 2134 struct mount *mp; 2135 2136 *bo = LIST_FIRST(slp); 2137 if (*bo == NULL) 2138 return (0); 2139 vp = bo2vnode(*bo); 2140 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2141 return (1); 2142 /* 2143 * We use vhold in case the vnode does not 2144 * successfully sync. vhold prevents the vnode from 2145 * going away when we unlock the sync_mtx so that 2146 * we can acquire the vnode interlock. 2147 */ 2148 vholdl(vp); 2149 mtx_unlock(&sync_mtx); 2150 VI_UNLOCK(vp); 2151 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2152 vdrop(vp); 2153 mtx_lock(&sync_mtx); 2154 return (*bo == LIST_FIRST(slp)); 2155 } 2156 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2157 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2158 VOP_UNLOCK(vp, 0); 2159 vn_finished_write(mp); 2160 BO_LOCK(*bo); 2161 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2162 /* 2163 * Put us back on the worklist. The worklist 2164 * routine will remove us from our current 2165 * position and then add us back in at a later 2166 * position. 2167 */ 2168 vn_syncer_add_to_worklist(*bo, syncdelay); 2169 } 2170 BO_UNLOCK(*bo); 2171 vdrop(vp); 2172 mtx_lock(&sync_mtx); 2173 return (0); 2174 } 2175 2176 static int first_printf = 1; 2177 2178 /* 2179 * System filesystem synchronizer daemon. 2180 */ 2181 static void 2182 sched_sync(void) 2183 { 2184 struct synclist *next, *slp; 2185 struct bufobj *bo; 2186 long starttime; 2187 struct thread *td = curthread; 2188 int last_work_seen; 2189 int net_worklist_len; 2190 int syncer_final_iter; 2191 int error; 2192 2193 last_work_seen = 0; 2194 syncer_final_iter = 0; 2195 syncer_state = SYNCER_RUNNING; 2196 starttime = time_uptime; 2197 td->td_pflags |= TDP_NORUNNINGBUF; 2198 2199 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2200 SHUTDOWN_PRI_LAST); 2201 2202 mtx_lock(&sync_mtx); 2203 for (;;) { 2204 if (syncer_state == SYNCER_FINAL_DELAY && 2205 syncer_final_iter == 0) { 2206 mtx_unlock(&sync_mtx); 2207 kproc_suspend_check(td->td_proc); 2208 mtx_lock(&sync_mtx); 2209 } 2210 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2211 if (syncer_state != SYNCER_RUNNING && 2212 starttime != time_uptime) { 2213 if (first_printf) { 2214 printf("\nSyncing disks, vnodes remaining... "); 2215 first_printf = 0; 2216 } 2217 printf("%d ", net_worklist_len); 2218 } 2219 starttime = time_uptime; 2220 2221 /* 2222 * Push files whose dirty time has expired. Be careful 2223 * of interrupt race on slp queue. 2224 * 2225 * Skip over empty worklist slots when shutting down. 2226 */ 2227 do { 2228 slp = &syncer_workitem_pending[syncer_delayno]; 2229 syncer_delayno += 1; 2230 if (syncer_delayno == syncer_maxdelay) 2231 syncer_delayno = 0; 2232 next = &syncer_workitem_pending[syncer_delayno]; 2233 /* 2234 * If the worklist has wrapped since the 2235 * it was emptied of all but syncer vnodes, 2236 * switch to the FINAL_DELAY state and run 2237 * for one more second. 2238 */ 2239 if (syncer_state == SYNCER_SHUTTING_DOWN && 2240 net_worklist_len == 0 && 2241 last_work_seen == syncer_delayno) { 2242 syncer_state = SYNCER_FINAL_DELAY; 2243 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2244 } 2245 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2246 syncer_worklist_len > 0); 2247 2248 /* 2249 * Keep track of the last time there was anything 2250 * on the worklist other than syncer vnodes. 2251 * Return to the SHUTTING_DOWN state if any 2252 * new work appears. 2253 */ 2254 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2255 last_work_seen = syncer_delayno; 2256 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2257 syncer_state = SYNCER_SHUTTING_DOWN; 2258 while (!LIST_EMPTY(slp)) { 2259 error = sync_vnode(slp, &bo, td); 2260 if (error == 1) { 2261 LIST_REMOVE(bo, bo_synclist); 2262 LIST_INSERT_HEAD(next, bo, bo_synclist); 2263 continue; 2264 } 2265 2266 if (first_printf == 0) { 2267 /* 2268 * Drop the sync mutex, because some watchdog 2269 * drivers need to sleep while patting 2270 */ 2271 mtx_unlock(&sync_mtx); 2272 wdog_kern_pat(WD_LASTVAL); 2273 mtx_lock(&sync_mtx); 2274 } 2275 2276 } 2277 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2278 syncer_final_iter--; 2279 /* 2280 * The variable rushjob allows the kernel to speed up the 2281 * processing of the filesystem syncer process. A rushjob 2282 * value of N tells the filesystem syncer to process the next 2283 * N seconds worth of work on its queue ASAP. Currently rushjob 2284 * is used by the soft update code to speed up the filesystem 2285 * syncer process when the incore state is getting so far 2286 * ahead of the disk that the kernel memory pool is being 2287 * threatened with exhaustion. 2288 */ 2289 if (rushjob > 0) { 2290 rushjob -= 1; 2291 continue; 2292 } 2293 /* 2294 * Just sleep for a short period of time between 2295 * iterations when shutting down to allow some I/O 2296 * to happen. 2297 * 2298 * If it has taken us less than a second to process the 2299 * current work, then wait. Otherwise start right over 2300 * again. We can still lose time if any single round 2301 * takes more than two seconds, but it does not really 2302 * matter as we are just trying to generally pace the 2303 * filesystem activity. 2304 */ 2305 if (syncer_state != SYNCER_RUNNING || 2306 time_uptime == starttime) { 2307 thread_lock(td); 2308 sched_prio(td, PPAUSE); 2309 thread_unlock(td); 2310 } 2311 if (syncer_state != SYNCER_RUNNING) 2312 cv_timedwait(&sync_wakeup, &sync_mtx, 2313 hz / SYNCER_SHUTDOWN_SPEEDUP); 2314 else if (time_uptime == starttime) 2315 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2316 } 2317 } 2318 2319 /* 2320 * Request the syncer daemon to speed up its work. 2321 * We never push it to speed up more than half of its 2322 * normal turn time, otherwise it could take over the cpu. 2323 */ 2324 int 2325 speedup_syncer(void) 2326 { 2327 int ret = 0; 2328 2329 mtx_lock(&sync_mtx); 2330 if (rushjob < syncdelay / 2) { 2331 rushjob += 1; 2332 stat_rush_requests += 1; 2333 ret = 1; 2334 } 2335 mtx_unlock(&sync_mtx); 2336 cv_broadcast(&sync_wakeup); 2337 return (ret); 2338 } 2339 2340 /* 2341 * Tell the syncer to speed up its work and run though its work 2342 * list several times, then tell it to shut down. 2343 */ 2344 static void 2345 syncer_shutdown(void *arg, int howto) 2346 { 2347 2348 if (howto & RB_NOSYNC) 2349 return; 2350 mtx_lock(&sync_mtx); 2351 syncer_state = SYNCER_SHUTTING_DOWN; 2352 rushjob = 0; 2353 mtx_unlock(&sync_mtx); 2354 cv_broadcast(&sync_wakeup); 2355 kproc_shutdown(arg, howto); 2356 } 2357 2358 void 2359 syncer_suspend(void) 2360 { 2361 2362 syncer_shutdown(updateproc, 0); 2363 } 2364 2365 void 2366 syncer_resume(void) 2367 { 2368 2369 mtx_lock(&sync_mtx); 2370 first_printf = 1; 2371 syncer_state = SYNCER_RUNNING; 2372 mtx_unlock(&sync_mtx); 2373 cv_broadcast(&sync_wakeup); 2374 kproc_resume(updateproc); 2375 } 2376 2377 /* 2378 * Reassign a buffer from one vnode to another. 2379 * Used to assign file specific control information 2380 * (indirect blocks) to the vnode to which they belong. 2381 */ 2382 void 2383 reassignbuf(struct buf *bp) 2384 { 2385 struct vnode *vp; 2386 struct bufobj *bo; 2387 int delay; 2388 #ifdef INVARIANTS 2389 struct bufv *bv; 2390 #endif 2391 2392 vp = bp->b_vp; 2393 bo = bp->b_bufobj; 2394 ++reassignbufcalls; 2395 2396 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2397 bp, bp->b_vp, bp->b_flags); 2398 /* 2399 * B_PAGING flagged buffers cannot be reassigned because their vp 2400 * is not fully linked in. 2401 */ 2402 if (bp->b_flags & B_PAGING) 2403 panic("cannot reassign paging buffer"); 2404 2405 /* 2406 * Delete from old vnode list, if on one. 2407 */ 2408 BO_LOCK(bo); 2409 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2410 buf_vlist_remove(bp); 2411 else 2412 panic("reassignbuf: Buffer %p not on queue.", bp); 2413 /* 2414 * If dirty, put on list of dirty buffers; otherwise insert onto list 2415 * of clean buffers. 2416 */ 2417 if (bp->b_flags & B_DELWRI) { 2418 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2419 switch (vp->v_type) { 2420 case VDIR: 2421 delay = dirdelay; 2422 break; 2423 case VCHR: 2424 delay = metadelay; 2425 break; 2426 default: 2427 delay = filedelay; 2428 } 2429 vn_syncer_add_to_worklist(bo, delay); 2430 } 2431 buf_vlist_add(bp, bo, BX_VNDIRTY); 2432 } else { 2433 buf_vlist_add(bp, bo, BX_VNCLEAN); 2434 2435 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2436 mtx_lock(&sync_mtx); 2437 LIST_REMOVE(bo, bo_synclist); 2438 syncer_worklist_len--; 2439 mtx_unlock(&sync_mtx); 2440 bo->bo_flag &= ~BO_ONWORKLST; 2441 } 2442 } 2443 #ifdef INVARIANTS 2444 bv = &bo->bo_clean; 2445 bp = TAILQ_FIRST(&bv->bv_hd); 2446 KASSERT(bp == NULL || bp->b_bufobj == bo, 2447 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2448 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2449 KASSERT(bp == NULL || bp->b_bufobj == bo, 2450 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2451 bv = &bo->bo_dirty; 2452 bp = TAILQ_FIRST(&bv->bv_hd); 2453 KASSERT(bp == NULL || bp->b_bufobj == bo, 2454 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2455 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2456 KASSERT(bp == NULL || bp->b_bufobj == bo, 2457 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2458 #endif 2459 BO_UNLOCK(bo); 2460 } 2461 2462 /* 2463 * A temporary hack until refcount_* APIs are sorted out. 2464 */ 2465 static __inline int 2466 vfs_refcount_acquire_if_not_zero(volatile u_int *count) 2467 { 2468 u_int old; 2469 2470 old = *count; 2471 for (;;) { 2472 if (old == 0) 2473 return (0); 2474 if (atomic_fcmpset_int(count, &old, old + 1)) 2475 return (1); 2476 } 2477 } 2478 2479 static __inline int 2480 vfs_refcount_release_if_not_last(volatile u_int *count) 2481 { 2482 u_int old; 2483 2484 old = *count; 2485 for (;;) { 2486 if (old == 1) 2487 return (0); 2488 if (atomic_fcmpset_int(count, &old, old - 1)) 2489 return (1); 2490 } 2491 } 2492 2493 static void 2494 v_init_counters(struct vnode *vp) 2495 { 2496 2497 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2498 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2499 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2500 2501 refcount_init(&vp->v_holdcnt, 1); 2502 refcount_init(&vp->v_usecount, 1); 2503 } 2504 2505 static void 2506 v_incr_usecount_locked(struct vnode *vp) 2507 { 2508 2509 ASSERT_VI_LOCKED(vp, __func__); 2510 if ((vp->v_iflag & VI_OWEINACT) != 0) { 2511 VNASSERT(vp->v_usecount == 0, vp, 2512 ("vnode with usecount and VI_OWEINACT set")); 2513 vp->v_iflag &= ~VI_OWEINACT; 2514 } 2515 refcount_acquire(&vp->v_usecount); 2516 v_incr_devcount(vp); 2517 } 2518 2519 /* 2520 * Increment the use count on the vnode, taking care to reference 2521 * the driver's usecount if this is a chardev. 2522 */ 2523 static void 2524 v_incr_usecount(struct vnode *vp) 2525 { 2526 2527 ASSERT_VI_UNLOCKED(vp, __func__); 2528 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2529 2530 if (vp->v_type != VCHR && 2531 vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) { 2532 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2533 ("vnode with usecount and VI_OWEINACT set")); 2534 } else { 2535 VI_LOCK(vp); 2536 v_incr_usecount_locked(vp); 2537 VI_UNLOCK(vp); 2538 } 2539 } 2540 2541 /* 2542 * Increment si_usecount of the associated device, if any. 2543 */ 2544 static void 2545 v_incr_devcount(struct vnode *vp) 2546 { 2547 2548 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2549 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2550 dev_lock(); 2551 vp->v_rdev->si_usecount++; 2552 dev_unlock(); 2553 } 2554 } 2555 2556 /* 2557 * Decrement si_usecount of the associated device, if any. 2558 */ 2559 static void 2560 v_decr_devcount(struct vnode *vp) 2561 { 2562 2563 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2564 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2565 dev_lock(); 2566 vp->v_rdev->si_usecount--; 2567 dev_unlock(); 2568 } 2569 } 2570 2571 /* 2572 * Grab a particular vnode from the free list, increment its 2573 * reference count and lock it. VI_DOOMED is set if the vnode 2574 * is being destroyed. Only callers who specify LK_RETRY will 2575 * see doomed vnodes. If inactive processing was delayed in 2576 * vput try to do it here. 2577 * 2578 * Notes on lockless counter manipulation: 2579 * _vhold, vputx and other routines make various decisions based 2580 * on either holdcnt or usecount being 0. As long as either counter 2581 * is not transitioning 0->1 nor 1->0, the manipulation can be done 2582 * with atomic operations. Otherwise the interlock is taken covering 2583 * both the atomic and additional actions. 2584 */ 2585 int 2586 vget(struct vnode *vp, int flags, struct thread *td) 2587 { 2588 int error, oweinact; 2589 2590 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2591 ("vget: invalid lock operation")); 2592 2593 if ((flags & LK_INTERLOCK) != 0) 2594 ASSERT_VI_LOCKED(vp, __func__); 2595 else 2596 ASSERT_VI_UNLOCKED(vp, __func__); 2597 if ((flags & LK_VNHELD) != 0) 2598 VNASSERT((vp->v_holdcnt > 0), vp, 2599 ("vget: LK_VNHELD passed but vnode not held")); 2600 2601 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2602 2603 if ((flags & LK_VNHELD) == 0) 2604 _vhold(vp, (flags & LK_INTERLOCK) != 0); 2605 2606 if ((error = vn_lock(vp, flags)) != 0) { 2607 vdrop(vp); 2608 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2609 vp); 2610 return (error); 2611 } 2612 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2613 panic("vget: vn_lock failed to return ENOENT\n"); 2614 /* 2615 * We don't guarantee that any particular close will 2616 * trigger inactive processing so just make a best effort 2617 * here at preventing a reference to a removed file. If 2618 * we don't succeed no harm is done. 2619 * 2620 * Upgrade our holdcnt to a usecount. 2621 */ 2622 if (vp->v_type == VCHR || 2623 !vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) { 2624 VI_LOCK(vp); 2625 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2626 oweinact = 0; 2627 } else { 2628 oweinact = 1; 2629 vp->v_iflag &= ~VI_OWEINACT; 2630 } 2631 refcount_acquire(&vp->v_usecount); 2632 v_incr_devcount(vp); 2633 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2634 (flags & LK_NOWAIT) == 0) 2635 vinactive(vp, td); 2636 VI_UNLOCK(vp); 2637 } 2638 return (0); 2639 } 2640 2641 /* 2642 * Increase the reference (use) and hold count of a vnode. 2643 * This will also remove the vnode from the free list if it is presently free. 2644 */ 2645 void 2646 vref(struct vnode *vp) 2647 { 2648 2649 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2650 _vhold(vp, false); 2651 v_incr_usecount(vp); 2652 } 2653 2654 void 2655 vrefl(struct vnode *vp) 2656 { 2657 2658 ASSERT_VI_LOCKED(vp, __func__); 2659 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2660 _vhold(vp, true); 2661 v_incr_usecount_locked(vp); 2662 } 2663 2664 void 2665 vrefact(struct vnode *vp) 2666 { 2667 2668 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2669 if (__predict_false(vp->v_type == VCHR)) { 2670 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 2671 ("%s: wrong ref counts", __func__)); 2672 vref(vp); 2673 return; 2674 } 2675 #ifdef INVARIANTS 2676 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 2677 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__)); 2678 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2679 VNASSERT(old > 0, vp, ("%s: wrong use count", __func__)); 2680 #else 2681 refcount_acquire(&vp->v_holdcnt); 2682 refcount_acquire(&vp->v_usecount); 2683 #endif 2684 } 2685 2686 /* 2687 * Return reference count of a vnode. 2688 * 2689 * The results of this call are only guaranteed when some mechanism is used to 2690 * stop other processes from gaining references to the vnode. This may be the 2691 * case if the caller holds the only reference. This is also useful when stale 2692 * data is acceptable as race conditions may be accounted for by some other 2693 * means. 2694 */ 2695 int 2696 vrefcnt(struct vnode *vp) 2697 { 2698 2699 return (vp->v_usecount); 2700 } 2701 2702 #define VPUTX_VRELE 1 2703 #define VPUTX_VPUT 2 2704 #define VPUTX_VUNREF 3 2705 2706 /* 2707 * Decrement the use and hold counts for a vnode. 2708 * 2709 * See an explanation near vget() as to why atomic operation is safe. 2710 */ 2711 static void 2712 vputx(struct vnode *vp, int func) 2713 { 2714 int error; 2715 2716 KASSERT(vp != NULL, ("vputx: null vp")); 2717 if (func == VPUTX_VUNREF) 2718 ASSERT_VOP_LOCKED(vp, "vunref"); 2719 else if (func == VPUTX_VPUT) 2720 ASSERT_VOP_LOCKED(vp, "vput"); 2721 else 2722 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); 2723 ASSERT_VI_UNLOCKED(vp, __func__); 2724 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2725 2726 if (vp->v_type != VCHR && 2727 vfs_refcount_release_if_not_last(&vp->v_usecount)) { 2728 if (func == VPUTX_VPUT) 2729 VOP_UNLOCK(vp, 0); 2730 vdrop(vp); 2731 return; 2732 } 2733 2734 VI_LOCK(vp); 2735 2736 /* 2737 * We want to hold the vnode until the inactive finishes to 2738 * prevent vgone() races. We drop the use count here and the 2739 * hold count below when we're done. 2740 */ 2741 if (!refcount_release(&vp->v_usecount) || 2742 (vp->v_iflag & VI_DOINGINACT)) { 2743 if (func == VPUTX_VPUT) 2744 VOP_UNLOCK(vp, 0); 2745 v_decr_devcount(vp); 2746 vdropl(vp); 2747 return; 2748 } 2749 2750 v_decr_devcount(vp); 2751 2752 error = 0; 2753 2754 if (vp->v_usecount != 0) { 2755 vn_printf(vp, "vputx: usecount not zero for vnode "); 2756 panic("vputx: usecount not zero"); 2757 } 2758 2759 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); 2760 2761 /* 2762 * We must call VOP_INACTIVE with the node locked. Mark 2763 * as VI_DOINGINACT to avoid recursion. 2764 */ 2765 vp->v_iflag |= VI_OWEINACT; 2766 switch (func) { 2767 case VPUTX_VRELE: 2768 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2769 VI_LOCK(vp); 2770 break; 2771 case VPUTX_VPUT: 2772 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2773 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 2774 LK_NOWAIT); 2775 VI_LOCK(vp); 2776 } 2777 break; 2778 case VPUTX_VUNREF: 2779 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2780 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 2781 VI_LOCK(vp); 2782 } 2783 break; 2784 } 2785 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, 2786 ("vnode with usecount and VI_OWEINACT set")); 2787 if (error == 0) { 2788 if (vp->v_iflag & VI_OWEINACT) 2789 vinactive(vp, curthread); 2790 if (func != VPUTX_VUNREF) 2791 VOP_UNLOCK(vp, 0); 2792 } 2793 vdropl(vp); 2794 } 2795 2796 /* 2797 * Vnode put/release. 2798 * If count drops to zero, call inactive routine and return to freelist. 2799 */ 2800 void 2801 vrele(struct vnode *vp) 2802 { 2803 2804 vputx(vp, VPUTX_VRELE); 2805 } 2806 2807 /* 2808 * Release an already locked vnode. This give the same effects as 2809 * unlock+vrele(), but takes less time and avoids releasing and 2810 * re-aquiring the lock (as vrele() acquires the lock internally.) 2811 */ 2812 void 2813 vput(struct vnode *vp) 2814 { 2815 2816 vputx(vp, VPUTX_VPUT); 2817 } 2818 2819 /* 2820 * Release an exclusively locked vnode. Do not unlock the vnode lock. 2821 */ 2822 void 2823 vunref(struct vnode *vp) 2824 { 2825 2826 vputx(vp, VPUTX_VUNREF); 2827 } 2828 2829 /* 2830 * Increase the hold count and activate if this is the first reference. 2831 */ 2832 void 2833 _vhold(struct vnode *vp, bool locked) 2834 { 2835 struct mount *mp; 2836 2837 if (locked) 2838 ASSERT_VI_LOCKED(vp, __func__); 2839 else 2840 ASSERT_VI_UNLOCKED(vp, __func__); 2841 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2842 if (!locked && vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt)) { 2843 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2844 ("_vhold: vnode with holdcnt is free")); 2845 return; 2846 } 2847 2848 if (!locked) 2849 VI_LOCK(vp); 2850 if ((vp->v_iflag & VI_FREE) == 0) { 2851 refcount_acquire(&vp->v_holdcnt); 2852 if (!locked) 2853 VI_UNLOCK(vp); 2854 return; 2855 } 2856 VNASSERT(vp->v_holdcnt == 0, vp, 2857 ("%s: wrong hold count", __func__)); 2858 VNASSERT(vp->v_op != NULL, vp, 2859 ("%s: vnode already reclaimed.", __func__)); 2860 /* 2861 * Remove a vnode from the free list, mark it as in use, 2862 * and put it on the active list. 2863 */ 2864 mp = vp->v_mount; 2865 mtx_lock(&mp->mnt_listmtx); 2866 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { 2867 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 2868 mp->mnt_tmpfreevnodelistsize--; 2869 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 2870 } else { 2871 mtx_lock(&vnode_free_list_mtx); 2872 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 2873 freevnodes--; 2874 mtx_unlock(&vnode_free_list_mtx); 2875 } 2876 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 2877 ("Activating already active vnode")); 2878 vp->v_iflag &= ~VI_FREE; 2879 vp->v_iflag |= VI_ACTIVE; 2880 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 2881 mp->mnt_activevnodelistsize++; 2882 mtx_unlock(&mp->mnt_listmtx); 2883 refcount_acquire(&vp->v_holdcnt); 2884 if (!locked) 2885 VI_UNLOCK(vp); 2886 } 2887 2888 /* 2889 * Drop the hold count of the vnode. If this is the last reference to 2890 * the vnode we place it on the free list unless it has been vgone'd 2891 * (marked VI_DOOMED) in which case we will free it. 2892 * 2893 * Because the vnode vm object keeps a hold reference on the vnode if 2894 * there is at least one resident non-cached page, the vnode cannot 2895 * leave the active list without the page cleanup done. 2896 */ 2897 void 2898 _vdrop(struct vnode *vp, bool locked) 2899 { 2900 struct bufobj *bo; 2901 struct mount *mp; 2902 int active; 2903 2904 if (locked) 2905 ASSERT_VI_LOCKED(vp, __func__); 2906 else 2907 ASSERT_VI_UNLOCKED(vp, __func__); 2908 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2909 if ((int)vp->v_holdcnt <= 0) 2910 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2911 if (vfs_refcount_release_if_not_last(&vp->v_holdcnt)) { 2912 if (locked) 2913 VI_UNLOCK(vp); 2914 return; 2915 } 2916 2917 if (!locked) 2918 VI_LOCK(vp); 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 mtx_lock(&mp->mnt_listmtx); 2939 if (active) { 2940 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, 2941 v_actfreelist); 2942 mp->mnt_activevnodelistsize--; 2943 } 2944 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, vp, 2945 v_actfreelist); 2946 mp->mnt_tmpfreevnodelistsize++; 2947 vp->v_iflag |= VI_FREE; 2948 vp->v_mflag |= VMP_TMPMNTFREELIST; 2949 VI_UNLOCK(vp); 2950 if (mp->mnt_tmpfreevnodelistsize >= mnt_free_list_batch) 2951 vnlru_return_batch_locked(mp); 2952 mtx_unlock(&mp->mnt_listmtx); 2953 } else { 2954 VI_UNLOCK(vp); 2955 counter_u64_add(free_owe_inact, 1); 2956 } 2957 return; 2958 } 2959 /* 2960 * The vnode has been marked for destruction, so free it. 2961 * 2962 * The vnode will be returned to the zone where it will 2963 * normally remain until it is needed for another vnode. We 2964 * need to cleanup (or verify that the cleanup has already 2965 * been done) any residual data left from its current use 2966 * so as not to contaminate the freshly allocated vnode. 2967 */ 2968 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 2969 atomic_subtract_long(&numvnodes, 1); 2970 bo = &vp->v_bufobj; 2971 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2972 ("cleaned vnode still on the free list.")); 2973 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 2974 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 2975 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 2976 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 2977 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 2978 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 2979 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 2980 ("clean blk trie not empty")); 2981 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 2982 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 2983 ("dirty blk trie not empty")); 2984 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 2985 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 2986 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 2987 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 2988 ("Dangling rangelock waiters")); 2989 VI_UNLOCK(vp); 2990 #ifdef MAC 2991 mac_vnode_destroy(vp); 2992 #endif 2993 if (vp->v_pollinfo != NULL) { 2994 destroy_vpollinfo(vp->v_pollinfo); 2995 vp->v_pollinfo = NULL; 2996 } 2997 #ifdef INVARIANTS 2998 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 2999 vp->v_op = NULL; 3000 #endif 3001 vp->v_mountedhere = NULL; 3002 vp->v_unpcb = NULL; 3003 vp->v_rdev = NULL; 3004 vp->v_fifoinfo = NULL; 3005 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 3006 vp->v_iflag = 0; 3007 vp->v_vflag = 0; 3008 bo->bo_flag = 0; 3009 uma_zfree(vnode_zone, vp); 3010 } 3011 3012 /* 3013 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3014 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3015 * OWEINACT tracks whether a vnode missed a call to inactive due to a 3016 * failed lock upgrade. 3017 */ 3018 void 3019 vinactive(struct vnode *vp, struct thread *td) 3020 { 3021 struct vm_object *obj; 3022 3023 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3024 ASSERT_VI_LOCKED(vp, "vinactive"); 3025 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3026 ("vinactive: recursed on VI_DOINGINACT")); 3027 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3028 vp->v_iflag |= VI_DOINGINACT; 3029 vp->v_iflag &= ~VI_OWEINACT; 3030 VI_UNLOCK(vp); 3031 /* 3032 * Before moving off the active list, we must be sure that any 3033 * modified pages are converted into the vnode's dirty 3034 * buffers, since these will no longer be checked once the 3035 * vnode is on the inactive list. 3036 * 3037 * The write-out of the dirty pages is asynchronous. At the 3038 * point that VOP_INACTIVE() is called, there could still be 3039 * pending I/O and dirty pages in the object. 3040 */ 3041 obj = vp->v_object; 3042 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { 3043 VM_OBJECT_WLOCK(obj); 3044 vm_object_page_clean(obj, 0, 0, 0); 3045 VM_OBJECT_WUNLOCK(obj); 3046 } 3047 VOP_INACTIVE(vp, td); 3048 VI_LOCK(vp); 3049 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3050 ("vinactive: lost VI_DOINGINACT")); 3051 vp->v_iflag &= ~VI_DOINGINACT; 3052 } 3053 3054 /* 3055 * Remove any vnodes in the vnode table belonging to mount point mp. 3056 * 3057 * If FORCECLOSE is not specified, there should not be any active ones, 3058 * return error if any are found (nb: this is a user error, not a 3059 * system error). If FORCECLOSE is specified, detach any active vnodes 3060 * that are found. 3061 * 3062 * If WRITECLOSE is set, only flush out regular file vnodes open for 3063 * writing. 3064 * 3065 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3066 * 3067 * `rootrefs' specifies the base reference count for the root vnode 3068 * of this filesystem. The root vnode is considered busy if its 3069 * v_usecount exceeds this value. On a successful return, vflush(, td) 3070 * will call vrele() on the root vnode exactly rootrefs times. 3071 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3072 * be zero. 3073 */ 3074 #ifdef DIAGNOSTIC 3075 static int busyprt = 0; /* print out busy vnodes */ 3076 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3077 #endif 3078 3079 int 3080 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3081 { 3082 struct vnode *vp, *mvp, *rootvp = NULL; 3083 struct vattr vattr; 3084 int busy = 0, error; 3085 3086 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3087 rootrefs, flags); 3088 if (rootrefs > 0) { 3089 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3090 ("vflush: bad args")); 3091 /* 3092 * Get the filesystem root vnode. We can vput() it 3093 * immediately, since with rootrefs > 0, it won't go away. 3094 */ 3095 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3096 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3097 __func__, error); 3098 return (error); 3099 } 3100 vput(rootvp); 3101 } 3102 loop: 3103 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3104 vholdl(vp); 3105 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3106 if (error) { 3107 vdrop(vp); 3108 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3109 goto loop; 3110 } 3111 /* 3112 * Skip over a vnodes marked VV_SYSTEM. 3113 */ 3114 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3115 VOP_UNLOCK(vp, 0); 3116 vdrop(vp); 3117 continue; 3118 } 3119 /* 3120 * If WRITECLOSE is set, flush out unlinked but still open 3121 * files (even if open only for reading) and regular file 3122 * vnodes open for writing. 3123 */ 3124 if (flags & WRITECLOSE) { 3125 if (vp->v_object != NULL) { 3126 VM_OBJECT_WLOCK(vp->v_object); 3127 vm_object_page_clean(vp->v_object, 0, 0, 0); 3128 VM_OBJECT_WUNLOCK(vp->v_object); 3129 } 3130 error = VOP_FSYNC(vp, MNT_WAIT, td); 3131 if (error != 0) { 3132 VOP_UNLOCK(vp, 0); 3133 vdrop(vp); 3134 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3135 return (error); 3136 } 3137 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3138 VI_LOCK(vp); 3139 3140 if ((vp->v_type == VNON || 3141 (error == 0 && vattr.va_nlink > 0)) && 3142 (vp->v_writecount == 0 || vp->v_type != VREG)) { 3143 VOP_UNLOCK(vp, 0); 3144 vdropl(vp); 3145 continue; 3146 } 3147 } else 3148 VI_LOCK(vp); 3149 /* 3150 * With v_usecount == 0, all we need to do is clear out the 3151 * vnode data structures and we are done. 3152 * 3153 * If FORCECLOSE is set, forcibly close the vnode. 3154 */ 3155 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3156 vgonel(vp); 3157 } else { 3158 busy++; 3159 #ifdef DIAGNOSTIC 3160 if (busyprt) 3161 vn_printf(vp, "vflush: busy vnode "); 3162 #endif 3163 } 3164 VOP_UNLOCK(vp, 0); 3165 vdropl(vp); 3166 } 3167 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3168 /* 3169 * If just the root vnode is busy, and if its refcount 3170 * is equal to `rootrefs', then go ahead and kill it. 3171 */ 3172 VI_LOCK(rootvp); 3173 KASSERT(busy > 0, ("vflush: not busy")); 3174 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3175 ("vflush: usecount %d < rootrefs %d", 3176 rootvp->v_usecount, rootrefs)); 3177 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3178 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3179 vgone(rootvp); 3180 VOP_UNLOCK(rootvp, 0); 3181 busy = 0; 3182 } else 3183 VI_UNLOCK(rootvp); 3184 } 3185 if (busy) { 3186 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3187 busy); 3188 return (EBUSY); 3189 } 3190 for (; rootrefs > 0; rootrefs--) 3191 vrele(rootvp); 3192 return (0); 3193 } 3194 3195 /* 3196 * Recycle an unused vnode to the front of the free list. 3197 */ 3198 int 3199 vrecycle(struct vnode *vp) 3200 { 3201 int recycled; 3202 3203 VI_LOCK(vp); 3204 recycled = vrecyclel(vp); 3205 VI_UNLOCK(vp); 3206 return (recycled); 3207 } 3208 3209 /* 3210 * vrecycle, with the vp interlock held. 3211 */ 3212 int 3213 vrecyclel(struct vnode *vp) 3214 { 3215 int recycled; 3216 3217 ASSERT_VOP_ELOCKED(vp, __func__); 3218 ASSERT_VI_LOCKED(vp, __func__); 3219 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3220 recycled = 0; 3221 if (vp->v_usecount == 0) { 3222 recycled = 1; 3223 vgonel(vp); 3224 } 3225 return (recycled); 3226 } 3227 3228 /* 3229 * Eliminate all activity associated with a vnode 3230 * in preparation for reuse. 3231 */ 3232 void 3233 vgone(struct vnode *vp) 3234 { 3235 VI_LOCK(vp); 3236 vgonel(vp); 3237 VI_UNLOCK(vp); 3238 } 3239 3240 static void 3241 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3242 struct vnode *lowervp __unused) 3243 { 3244 } 3245 3246 /* 3247 * Notify upper mounts about reclaimed or unlinked vnode. 3248 */ 3249 void 3250 vfs_notify_upper(struct vnode *vp, int event) 3251 { 3252 static struct vfsops vgonel_vfsops = { 3253 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3254 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3255 }; 3256 struct mount *mp, *ump, *mmp; 3257 3258 mp = vp->v_mount; 3259 if (mp == NULL) 3260 return; 3261 3262 MNT_ILOCK(mp); 3263 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3264 goto unlock; 3265 MNT_IUNLOCK(mp); 3266 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3267 mmp->mnt_op = &vgonel_vfsops; 3268 mmp->mnt_kern_flag |= MNTK_MARKER; 3269 MNT_ILOCK(mp); 3270 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3271 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3272 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3273 ump = TAILQ_NEXT(ump, mnt_upper_link); 3274 continue; 3275 } 3276 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3277 MNT_IUNLOCK(mp); 3278 switch (event) { 3279 case VFS_NOTIFY_UPPER_RECLAIM: 3280 VFS_RECLAIM_LOWERVP(ump, vp); 3281 break; 3282 case VFS_NOTIFY_UPPER_UNLINK: 3283 VFS_UNLINK_LOWERVP(ump, vp); 3284 break; 3285 default: 3286 KASSERT(0, ("invalid event %d", event)); 3287 break; 3288 } 3289 MNT_ILOCK(mp); 3290 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3291 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3292 } 3293 free(mmp, M_TEMP); 3294 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3295 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3296 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3297 wakeup(&mp->mnt_uppers); 3298 } 3299 unlock: 3300 MNT_IUNLOCK(mp); 3301 } 3302 3303 /* 3304 * vgone, with the vp interlock held. 3305 */ 3306 static void 3307 vgonel(struct vnode *vp) 3308 { 3309 struct thread *td; 3310 int oweinact; 3311 int active; 3312 struct mount *mp; 3313 3314 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3315 ASSERT_VI_LOCKED(vp, "vgonel"); 3316 VNASSERT(vp->v_holdcnt, vp, 3317 ("vgonel: vp %p has no reference.", vp)); 3318 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3319 td = curthread; 3320 3321 /* 3322 * Don't vgonel if we're already doomed. 3323 */ 3324 if (vp->v_iflag & VI_DOOMED) 3325 return; 3326 vp->v_iflag |= VI_DOOMED; 3327 3328 /* 3329 * Check to see if the vnode is in use. If so, we have to call 3330 * VOP_CLOSE() and VOP_INACTIVE(). 3331 */ 3332 active = vp->v_usecount; 3333 oweinact = (vp->v_iflag & VI_OWEINACT); 3334 VI_UNLOCK(vp); 3335 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3336 3337 /* 3338 * If purging an active vnode, it must be closed and 3339 * deactivated before being reclaimed. 3340 */ 3341 if (active) 3342 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3343 if (oweinact || active) { 3344 VI_LOCK(vp); 3345 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3346 vinactive(vp, td); 3347 VI_UNLOCK(vp); 3348 } 3349 if (vp->v_type == VSOCK) 3350 vfs_unp_reclaim(vp); 3351 3352 /* 3353 * Clean out any buffers associated with the vnode. 3354 * If the flush fails, just toss the buffers. 3355 */ 3356 mp = NULL; 3357 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3358 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3359 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3360 while (vinvalbuf(vp, 0, 0, 0) != 0) 3361 ; 3362 } 3363 3364 BO_LOCK(&vp->v_bufobj); 3365 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3366 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3367 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3368 vp->v_bufobj.bo_clean.bv_cnt == 0, 3369 ("vp %p bufobj not invalidated", vp)); 3370 3371 /* 3372 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate() 3373 * after the object's page queue is flushed. 3374 */ 3375 if (vp->v_bufobj.bo_object == NULL) 3376 vp->v_bufobj.bo_flag |= BO_DEAD; 3377 BO_UNLOCK(&vp->v_bufobj); 3378 3379 /* 3380 * Reclaim the vnode. 3381 */ 3382 if (VOP_RECLAIM(vp, td)) 3383 panic("vgone: cannot reclaim"); 3384 if (mp != NULL) 3385 vn_finished_secondary_write(mp); 3386 VNASSERT(vp->v_object == NULL, vp, 3387 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3388 /* 3389 * Clear the advisory locks and wake up waiting threads. 3390 */ 3391 (void)VOP_ADVLOCKPURGE(vp); 3392 vp->v_lockf = NULL; 3393 /* 3394 * Delete from old mount point vnode list. 3395 */ 3396 delmntque(vp); 3397 cache_purge(vp); 3398 /* 3399 * Done with purge, reset to the standard lock and invalidate 3400 * the vnode. 3401 */ 3402 VI_LOCK(vp); 3403 vp->v_vnlock = &vp->v_lock; 3404 vp->v_op = &dead_vnodeops; 3405 vp->v_tag = "none"; 3406 vp->v_type = VBAD; 3407 } 3408 3409 /* 3410 * Calculate the total number of references to a special device. 3411 */ 3412 int 3413 vcount(struct vnode *vp) 3414 { 3415 int count; 3416 3417 dev_lock(); 3418 count = vp->v_rdev->si_usecount; 3419 dev_unlock(); 3420 return (count); 3421 } 3422 3423 /* 3424 * Same as above, but using the struct cdev *as argument 3425 */ 3426 int 3427 count_dev(struct cdev *dev) 3428 { 3429 int count; 3430 3431 dev_lock(); 3432 count = dev->si_usecount; 3433 dev_unlock(); 3434 return(count); 3435 } 3436 3437 /* 3438 * Print out a description of a vnode. 3439 */ 3440 static char *typename[] = 3441 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3442 "VMARKER"}; 3443 3444 void 3445 vn_printf(struct vnode *vp, const char *fmt, ...) 3446 { 3447 va_list ap; 3448 char buf[256], buf2[16]; 3449 u_long flags; 3450 3451 va_start(ap, fmt); 3452 vprintf(fmt, ap); 3453 va_end(ap); 3454 printf("%p: ", (void *)vp); 3455 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3456 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 3457 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 3458 buf[0] = '\0'; 3459 buf[1] = '\0'; 3460 if (vp->v_vflag & VV_ROOT) 3461 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3462 if (vp->v_vflag & VV_ISTTY) 3463 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3464 if (vp->v_vflag & VV_NOSYNC) 3465 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3466 if (vp->v_vflag & VV_ETERNALDEV) 3467 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3468 if (vp->v_vflag & VV_CACHEDLABEL) 3469 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3470 if (vp->v_vflag & VV_TEXT) 3471 strlcat(buf, "|VV_TEXT", sizeof(buf)); 3472 if (vp->v_vflag & VV_COPYONWRITE) 3473 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3474 if (vp->v_vflag & VV_SYSTEM) 3475 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3476 if (vp->v_vflag & VV_PROCDEP) 3477 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3478 if (vp->v_vflag & VV_NOKNOTE) 3479 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3480 if (vp->v_vflag & VV_DELETED) 3481 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3482 if (vp->v_vflag & VV_MD) 3483 strlcat(buf, "|VV_MD", sizeof(buf)); 3484 if (vp->v_vflag & VV_FORCEINSMQ) 3485 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3486 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3487 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3488 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3489 if (flags != 0) { 3490 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3491 strlcat(buf, buf2, sizeof(buf)); 3492 } 3493 if (vp->v_iflag & VI_MOUNT) 3494 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3495 if (vp->v_iflag & VI_DOOMED) 3496 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 3497 if (vp->v_iflag & VI_FREE) 3498 strlcat(buf, "|VI_FREE", sizeof(buf)); 3499 if (vp->v_iflag & VI_ACTIVE) 3500 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3501 if (vp->v_iflag & VI_DOINGINACT) 3502 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3503 if (vp->v_iflag & VI_OWEINACT) 3504 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3505 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | 3506 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT); 3507 if (flags != 0) { 3508 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3509 strlcat(buf, buf2, sizeof(buf)); 3510 } 3511 printf(" flags (%s)\n", buf + 1); 3512 if (mtx_owned(VI_MTX(vp))) 3513 printf(" VI_LOCKed"); 3514 if (vp->v_object != NULL) 3515 printf(" v_object %p ref %d pages %d " 3516 "cleanbuf %d dirtybuf %d\n", 3517 vp->v_object, vp->v_object->ref_count, 3518 vp->v_object->resident_page_count, 3519 vp->v_bufobj.bo_clean.bv_cnt, 3520 vp->v_bufobj.bo_dirty.bv_cnt); 3521 printf(" "); 3522 lockmgr_printinfo(vp->v_vnlock); 3523 if (vp->v_data != NULL) 3524 VOP_PRINT(vp); 3525 } 3526 3527 #ifdef DDB 3528 /* 3529 * List all of the locked vnodes in the system. 3530 * Called when debugging the kernel. 3531 */ 3532 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3533 { 3534 struct mount *mp; 3535 struct vnode *vp; 3536 3537 /* 3538 * Note: because this is DDB, we can't obey the locking semantics 3539 * for these structures, which means we could catch an inconsistent 3540 * state and dereference a nasty pointer. Not much to be done 3541 * about that. 3542 */ 3543 db_printf("Locked vnodes\n"); 3544 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3545 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3546 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3547 vn_printf(vp, "vnode "); 3548 } 3549 } 3550 } 3551 3552 /* 3553 * Show details about the given vnode. 3554 */ 3555 DB_SHOW_COMMAND(vnode, db_show_vnode) 3556 { 3557 struct vnode *vp; 3558 3559 if (!have_addr) 3560 return; 3561 vp = (struct vnode *)addr; 3562 vn_printf(vp, "vnode "); 3563 } 3564 3565 /* 3566 * Show details about the given mount point. 3567 */ 3568 DB_SHOW_COMMAND(mount, db_show_mount) 3569 { 3570 struct mount *mp; 3571 struct vfsopt *opt; 3572 struct statfs *sp; 3573 struct vnode *vp; 3574 char buf[512]; 3575 uint64_t mflags; 3576 u_int flags; 3577 3578 if (!have_addr) { 3579 /* No address given, print short info about all mount points. */ 3580 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3581 db_printf("%p %s on %s (%s)\n", mp, 3582 mp->mnt_stat.f_mntfromname, 3583 mp->mnt_stat.f_mntonname, 3584 mp->mnt_stat.f_fstypename); 3585 if (db_pager_quit) 3586 break; 3587 } 3588 db_printf("\nMore info: show mount <addr>\n"); 3589 return; 3590 } 3591 3592 mp = (struct mount *)addr; 3593 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3594 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3595 3596 buf[0] = '\0'; 3597 mflags = mp->mnt_flag; 3598 #define MNT_FLAG(flag) do { \ 3599 if (mflags & (flag)) { \ 3600 if (buf[0] != '\0') \ 3601 strlcat(buf, ", ", sizeof(buf)); \ 3602 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3603 mflags &= ~(flag); \ 3604 } \ 3605 } while (0) 3606 MNT_FLAG(MNT_RDONLY); 3607 MNT_FLAG(MNT_SYNCHRONOUS); 3608 MNT_FLAG(MNT_NOEXEC); 3609 MNT_FLAG(MNT_NOSUID); 3610 MNT_FLAG(MNT_NFS4ACLS); 3611 MNT_FLAG(MNT_UNION); 3612 MNT_FLAG(MNT_ASYNC); 3613 MNT_FLAG(MNT_SUIDDIR); 3614 MNT_FLAG(MNT_SOFTDEP); 3615 MNT_FLAG(MNT_NOSYMFOLLOW); 3616 MNT_FLAG(MNT_GJOURNAL); 3617 MNT_FLAG(MNT_MULTILABEL); 3618 MNT_FLAG(MNT_ACLS); 3619 MNT_FLAG(MNT_NOATIME); 3620 MNT_FLAG(MNT_NOCLUSTERR); 3621 MNT_FLAG(MNT_NOCLUSTERW); 3622 MNT_FLAG(MNT_SUJ); 3623 MNT_FLAG(MNT_EXRDONLY); 3624 MNT_FLAG(MNT_EXPORTED); 3625 MNT_FLAG(MNT_DEFEXPORTED); 3626 MNT_FLAG(MNT_EXPORTANON); 3627 MNT_FLAG(MNT_EXKERB); 3628 MNT_FLAG(MNT_EXPUBLIC); 3629 MNT_FLAG(MNT_LOCAL); 3630 MNT_FLAG(MNT_QUOTA); 3631 MNT_FLAG(MNT_ROOTFS); 3632 MNT_FLAG(MNT_USER); 3633 MNT_FLAG(MNT_IGNORE); 3634 MNT_FLAG(MNT_UPDATE); 3635 MNT_FLAG(MNT_DELEXPORT); 3636 MNT_FLAG(MNT_RELOAD); 3637 MNT_FLAG(MNT_FORCE); 3638 MNT_FLAG(MNT_SNAPSHOT); 3639 MNT_FLAG(MNT_BYFSID); 3640 #undef MNT_FLAG 3641 if (mflags != 0) { 3642 if (buf[0] != '\0') 3643 strlcat(buf, ", ", sizeof(buf)); 3644 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3645 "0x%016jx", mflags); 3646 } 3647 db_printf(" mnt_flag = %s\n", buf); 3648 3649 buf[0] = '\0'; 3650 flags = mp->mnt_kern_flag; 3651 #define MNT_KERN_FLAG(flag) do { \ 3652 if (flags & (flag)) { \ 3653 if (buf[0] != '\0') \ 3654 strlcat(buf, ", ", sizeof(buf)); \ 3655 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3656 flags &= ~(flag); \ 3657 } \ 3658 } while (0) 3659 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3660 MNT_KERN_FLAG(MNTK_ASYNC); 3661 MNT_KERN_FLAG(MNTK_SOFTDEP); 3662 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 3663 MNT_KERN_FLAG(MNTK_DRAINING); 3664 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3665 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3666 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3667 MNT_KERN_FLAG(MNTK_NO_IOPF); 3668 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3669 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3670 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3671 MNT_KERN_FLAG(MNTK_MARKER); 3672 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3673 MNT_KERN_FLAG(MNTK_NOASYNC); 3674 MNT_KERN_FLAG(MNTK_UNMOUNT); 3675 MNT_KERN_FLAG(MNTK_MWAIT); 3676 MNT_KERN_FLAG(MNTK_SUSPEND); 3677 MNT_KERN_FLAG(MNTK_SUSPEND2); 3678 MNT_KERN_FLAG(MNTK_SUSPENDED); 3679 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3680 MNT_KERN_FLAG(MNTK_NOKNOTE); 3681 #undef MNT_KERN_FLAG 3682 if (flags != 0) { 3683 if (buf[0] != '\0') 3684 strlcat(buf, ", ", sizeof(buf)); 3685 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3686 "0x%08x", flags); 3687 } 3688 db_printf(" mnt_kern_flag = %s\n", buf); 3689 3690 db_printf(" mnt_opt = "); 3691 opt = TAILQ_FIRST(mp->mnt_opt); 3692 if (opt != NULL) { 3693 db_printf("%s", opt->name); 3694 opt = TAILQ_NEXT(opt, link); 3695 while (opt != NULL) { 3696 db_printf(", %s", opt->name); 3697 opt = TAILQ_NEXT(opt, link); 3698 } 3699 } 3700 db_printf("\n"); 3701 3702 sp = &mp->mnt_stat; 3703 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3704 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3705 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3706 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3707 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3708 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 3709 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 3710 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 3711 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 3712 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 3713 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 3714 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 3715 3716 db_printf(" mnt_cred = { uid=%u ruid=%u", 3717 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 3718 if (jailed(mp->mnt_cred)) 3719 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 3720 db_printf(" }\n"); 3721 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 3722 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 3723 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 3724 db_printf(" mnt_activevnodelistsize = %d\n", 3725 mp->mnt_activevnodelistsize); 3726 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 3727 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 3728 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 3729 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 3730 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); 3731 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 3732 db_printf(" mnt_secondary_accwrites = %d\n", 3733 mp->mnt_secondary_accwrites); 3734 db_printf(" mnt_gjprovider = %s\n", 3735 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 3736 3737 db_printf("\n\nList of active vnodes\n"); 3738 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 3739 if (vp->v_type != VMARKER) { 3740 vn_printf(vp, "vnode "); 3741 if (db_pager_quit) 3742 break; 3743 } 3744 } 3745 db_printf("\n\nList of inactive vnodes\n"); 3746 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3747 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 3748 vn_printf(vp, "vnode "); 3749 if (db_pager_quit) 3750 break; 3751 } 3752 } 3753 } 3754 #endif /* DDB */ 3755 3756 /* 3757 * Fill in a struct xvfsconf based on a struct vfsconf. 3758 */ 3759 static int 3760 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 3761 { 3762 struct xvfsconf xvfsp; 3763 3764 bzero(&xvfsp, sizeof(xvfsp)); 3765 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3766 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3767 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3768 xvfsp.vfc_flags = vfsp->vfc_flags; 3769 /* 3770 * These are unused in userland, we keep them 3771 * to not break binary compatibility. 3772 */ 3773 xvfsp.vfc_vfsops = NULL; 3774 xvfsp.vfc_next = NULL; 3775 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3776 } 3777 3778 #ifdef COMPAT_FREEBSD32 3779 struct xvfsconf32 { 3780 uint32_t vfc_vfsops; 3781 char vfc_name[MFSNAMELEN]; 3782 int32_t vfc_typenum; 3783 int32_t vfc_refcount; 3784 int32_t vfc_flags; 3785 uint32_t vfc_next; 3786 }; 3787 3788 static int 3789 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 3790 { 3791 struct xvfsconf32 xvfsp; 3792 3793 bzero(&xvfsp, sizeof(xvfsp)); 3794 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3795 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3796 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3797 xvfsp.vfc_flags = vfsp->vfc_flags; 3798 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3799 } 3800 #endif 3801 3802 /* 3803 * Top level filesystem related information gathering. 3804 */ 3805 static int 3806 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3807 { 3808 struct vfsconf *vfsp; 3809 int error; 3810 3811 error = 0; 3812 vfsconf_slock(); 3813 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3814 #ifdef COMPAT_FREEBSD32 3815 if (req->flags & SCTL_MASK32) 3816 error = vfsconf2x32(req, vfsp); 3817 else 3818 #endif 3819 error = vfsconf2x(req, vfsp); 3820 if (error) 3821 break; 3822 } 3823 vfsconf_sunlock(); 3824 return (error); 3825 } 3826 3827 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 3828 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 3829 "S,xvfsconf", "List of all configured filesystems"); 3830 3831 #ifndef BURN_BRIDGES 3832 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3833 3834 static int 3835 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3836 { 3837 int *name = (int *)arg1 - 1; /* XXX */ 3838 u_int namelen = arg2 + 1; /* XXX */ 3839 struct vfsconf *vfsp; 3840 3841 log(LOG_WARNING, "userland calling deprecated sysctl, " 3842 "please rebuild world\n"); 3843 3844 #if 1 || defined(COMPAT_PRELITE2) 3845 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3846 if (namelen == 1) 3847 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3848 #endif 3849 3850 switch (name[1]) { 3851 case VFS_MAXTYPENUM: 3852 if (namelen != 2) 3853 return (ENOTDIR); 3854 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3855 case VFS_CONF: 3856 if (namelen != 3) 3857 return (ENOTDIR); /* overloaded */ 3858 vfsconf_slock(); 3859 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3860 if (vfsp->vfc_typenum == name[2]) 3861 break; 3862 } 3863 vfsconf_sunlock(); 3864 if (vfsp == NULL) 3865 return (EOPNOTSUPP); 3866 #ifdef COMPAT_FREEBSD32 3867 if (req->flags & SCTL_MASK32) 3868 return (vfsconf2x32(req, vfsp)); 3869 else 3870 #endif 3871 return (vfsconf2x(req, vfsp)); 3872 } 3873 return (EOPNOTSUPP); 3874 } 3875 3876 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 3877 CTLFLAG_MPSAFE, vfs_sysctl, 3878 "Generic filesystem"); 3879 3880 #if 1 || defined(COMPAT_PRELITE2) 3881 3882 static int 3883 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3884 { 3885 int error; 3886 struct vfsconf *vfsp; 3887 struct ovfsconf ovfs; 3888 3889 vfsconf_slock(); 3890 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3891 bzero(&ovfs, sizeof(ovfs)); 3892 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3893 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3894 ovfs.vfc_index = vfsp->vfc_typenum; 3895 ovfs.vfc_refcount = vfsp->vfc_refcount; 3896 ovfs.vfc_flags = vfsp->vfc_flags; 3897 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3898 if (error != 0) { 3899 vfsconf_sunlock(); 3900 return (error); 3901 } 3902 } 3903 vfsconf_sunlock(); 3904 return (0); 3905 } 3906 3907 #endif /* 1 || COMPAT_PRELITE2 */ 3908 #endif /* !BURN_BRIDGES */ 3909 3910 #define KINFO_VNODESLOP 10 3911 #ifdef notyet 3912 /* 3913 * Dump vnode list (via sysctl). 3914 */ 3915 /* ARGSUSED */ 3916 static int 3917 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3918 { 3919 struct xvnode *xvn; 3920 struct mount *mp; 3921 struct vnode *vp; 3922 int error, len, n; 3923 3924 /* 3925 * Stale numvnodes access is not fatal here. 3926 */ 3927 req->lock = 0; 3928 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3929 if (!req->oldptr) 3930 /* Make an estimate */ 3931 return (SYSCTL_OUT(req, 0, len)); 3932 3933 error = sysctl_wire_old_buffer(req, 0); 3934 if (error != 0) 3935 return (error); 3936 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3937 n = 0; 3938 mtx_lock(&mountlist_mtx); 3939 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3940 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 3941 continue; 3942 MNT_ILOCK(mp); 3943 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3944 if (n == len) 3945 break; 3946 vref(vp); 3947 xvn[n].xv_size = sizeof *xvn; 3948 xvn[n].xv_vnode = vp; 3949 xvn[n].xv_id = 0; /* XXX compat */ 3950 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3951 XV_COPY(usecount); 3952 XV_COPY(writecount); 3953 XV_COPY(holdcnt); 3954 XV_COPY(mount); 3955 XV_COPY(numoutput); 3956 XV_COPY(type); 3957 #undef XV_COPY 3958 xvn[n].xv_flag = vp->v_vflag; 3959 3960 switch (vp->v_type) { 3961 case VREG: 3962 case VDIR: 3963 case VLNK: 3964 break; 3965 case VBLK: 3966 case VCHR: 3967 if (vp->v_rdev == NULL) { 3968 vrele(vp); 3969 continue; 3970 } 3971 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3972 break; 3973 case VSOCK: 3974 xvn[n].xv_socket = vp->v_socket; 3975 break; 3976 case VFIFO: 3977 xvn[n].xv_fifo = vp->v_fifoinfo; 3978 break; 3979 case VNON: 3980 case VBAD: 3981 default: 3982 /* shouldn't happen? */ 3983 vrele(vp); 3984 continue; 3985 } 3986 vrele(vp); 3987 ++n; 3988 } 3989 MNT_IUNLOCK(mp); 3990 mtx_lock(&mountlist_mtx); 3991 vfs_unbusy(mp); 3992 if (n == len) 3993 break; 3994 } 3995 mtx_unlock(&mountlist_mtx); 3996 3997 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3998 free(xvn, M_TEMP); 3999 return (error); 4000 } 4001 4002 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4003 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4004 ""); 4005 #endif 4006 4007 static void 4008 unmount_or_warn(struct mount *mp) 4009 { 4010 int error; 4011 4012 error = dounmount(mp, MNT_FORCE, curthread); 4013 if (error != 0) { 4014 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4015 if (error == EBUSY) 4016 printf("BUSY)\n"); 4017 else 4018 printf("%d)\n", error); 4019 } 4020 } 4021 4022 /* 4023 * Unmount all filesystems. The list is traversed in reverse order 4024 * of mounting to avoid dependencies. 4025 */ 4026 void 4027 vfs_unmountall(void) 4028 { 4029 struct mount *mp, *tmp; 4030 4031 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4032 4033 /* 4034 * Since this only runs when rebooting, it is not interlocked. 4035 */ 4036 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4037 vfs_ref(mp); 4038 4039 /* 4040 * Forcibly unmounting "/dev" before "/" would prevent clean 4041 * unmount of the latter. 4042 */ 4043 if (mp == rootdevmp) 4044 continue; 4045 4046 unmount_or_warn(mp); 4047 } 4048 4049 if (rootdevmp != NULL) 4050 unmount_or_warn(rootdevmp); 4051 } 4052 4053 /* 4054 * perform msync on all vnodes under a mount point 4055 * the mount point must be locked. 4056 */ 4057 void 4058 vfs_msync(struct mount *mp, int flags) 4059 { 4060 struct vnode *vp, *mvp; 4061 struct vm_object *obj; 4062 4063 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4064 4065 vnlru_return_batch(mp); 4066 4067 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 4068 obj = vp->v_object; 4069 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 4070 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 4071 if (!vget(vp, 4072 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 4073 curthread)) { 4074 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 4075 vput(vp); 4076 continue; 4077 } 4078 4079 obj = vp->v_object; 4080 if (obj != NULL) { 4081 VM_OBJECT_WLOCK(obj); 4082 vm_object_page_clean(obj, 0, 0, 4083 flags == MNT_WAIT ? 4084 OBJPC_SYNC : OBJPC_NOSYNC); 4085 VM_OBJECT_WUNLOCK(obj); 4086 } 4087 vput(vp); 4088 } 4089 } else 4090 VI_UNLOCK(vp); 4091 } 4092 } 4093 4094 static void 4095 destroy_vpollinfo_free(struct vpollinfo *vi) 4096 { 4097 4098 knlist_destroy(&vi->vpi_selinfo.si_note); 4099 mtx_destroy(&vi->vpi_lock); 4100 uma_zfree(vnodepoll_zone, vi); 4101 } 4102 4103 static void 4104 destroy_vpollinfo(struct vpollinfo *vi) 4105 { 4106 4107 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4108 seldrain(&vi->vpi_selinfo); 4109 destroy_vpollinfo_free(vi); 4110 } 4111 4112 /* 4113 * Initialize per-vnode helper structure to hold poll-related state. 4114 */ 4115 void 4116 v_addpollinfo(struct vnode *vp) 4117 { 4118 struct vpollinfo *vi; 4119 4120 if (vp->v_pollinfo != NULL) 4121 return; 4122 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4123 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4124 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4125 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4126 VI_LOCK(vp); 4127 if (vp->v_pollinfo != NULL) { 4128 VI_UNLOCK(vp); 4129 destroy_vpollinfo_free(vi); 4130 return; 4131 } 4132 vp->v_pollinfo = vi; 4133 VI_UNLOCK(vp); 4134 } 4135 4136 /* 4137 * Record a process's interest in events which might happen to 4138 * a vnode. Because poll uses the historic select-style interface 4139 * internally, this routine serves as both the ``check for any 4140 * pending events'' and the ``record my interest in future events'' 4141 * functions. (These are done together, while the lock is held, 4142 * to avoid race conditions.) 4143 */ 4144 int 4145 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4146 { 4147 4148 v_addpollinfo(vp); 4149 mtx_lock(&vp->v_pollinfo->vpi_lock); 4150 if (vp->v_pollinfo->vpi_revents & events) { 4151 /* 4152 * This leaves events we are not interested 4153 * in available for the other process which 4154 * which presumably had requested them 4155 * (otherwise they would never have been 4156 * recorded). 4157 */ 4158 events &= vp->v_pollinfo->vpi_revents; 4159 vp->v_pollinfo->vpi_revents &= ~events; 4160 4161 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4162 return (events); 4163 } 4164 vp->v_pollinfo->vpi_events |= events; 4165 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4166 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4167 return (0); 4168 } 4169 4170 /* 4171 * Routine to create and manage a filesystem syncer vnode. 4172 */ 4173 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4174 static int sync_fsync(struct vop_fsync_args *); 4175 static int sync_inactive(struct vop_inactive_args *); 4176 static int sync_reclaim(struct vop_reclaim_args *); 4177 4178 static struct vop_vector sync_vnodeops = { 4179 .vop_bypass = VOP_EOPNOTSUPP, 4180 .vop_close = sync_close, /* close */ 4181 .vop_fsync = sync_fsync, /* fsync */ 4182 .vop_inactive = sync_inactive, /* inactive */ 4183 .vop_reclaim = sync_reclaim, /* reclaim */ 4184 .vop_lock1 = vop_stdlock, /* lock */ 4185 .vop_unlock = vop_stdunlock, /* unlock */ 4186 .vop_islocked = vop_stdislocked, /* islocked */ 4187 }; 4188 4189 /* 4190 * Create a new filesystem syncer vnode for the specified mount point. 4191 */ 4192 void 4193 vfs_allocate_syncvnode(struct mount *mp) 4194 { 4195 struct vnode *vp; 4196 struct bufobj *bo; 4197 static long start, incr, next; 4198 int error; 4199 4200 /* Allocate a new vnode */ 4201 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4202 if (error != 0) 4203 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4204 vp->v_type = VNON; 4205 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4206 vp->v_vflag |= VV_FORCEINSMQ; 4207 error = insmntque(vp, mp); 4208 if (error != 0) 4209 panic("vfs_allocate_syncvnode: insmntque() failed"); 4210 vp->v_vflag &= ~VV_FORCEINSMQ; 4211 VOP_UNLOCK(vp, 0); 4212 /* 4213 * Place the vnode onto the syncer worklist. We attempt to 4214 * scatter them about on the list so that they will go off 4215 * at evenly distributed times even if all the filesystems 4216 * are mounted at once. 4217 */ 4218 next += incr; 4219 if (next == 0 || next > syncer_maxdelay) { 4220 start /= 2; 4221 incr /= 2; 4222 if (start == 0) { 4223 start = syncer_maxdelay / 2; 4224 incr = syncer_maxdelay; 4225 } 4226 next = start; 4227 } 4228 bo = &vp->v_bufobj; 4229 BO_LOCK(bo); 4230 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4231 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4232 mtx_lock(&sync_mtx); 4233 sync_vnode_count++; 4234 if (mp->mnt_syncer == NULL) { 4235 mp->mnt_syncer = vp; 4236 vp = NULL; 4237 } 4238 mtx_unlock(&sync_mtx); 4239 BO_UNLOCK(bo); 4240 if (vp != NULL) { 4241 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4242 vgone(vp); 4243 vput(vp); 4244 } 4245 } 4246 4247 void 4248 vfs_deallocate_syncvnode(struct mount *mp) 4249 { 4250 struct vnode *vp; 4251 4252 mtx_lock(&sync_mtx); 4253 vp = mp->mnt_syncer; 4254 if (vp != NULL) 4255 mp->mnt_syncer = NULL; 4256 mtx_unlock(&sync_mtx); 4257 if (vp != NULL) 4258 vrele(vp); 4259 } 4260 4261 /* 4262 * Do a lazy sync of the filesystem. 4263 */ 4264 static int 4265 sync_fsync(struct vop_fsync_args *ap) 4266 { 4267 struct vnode *syncvp = ap->a_vp; 4268 struct mount *mp = syncvp->v_mount; 4269 int error, save; 4270 struct bufobj *bo; 4271 4272 /* 4273 * We only need to do something if this is a lazy evaluation. 4274 */ 4275 if (ap->a_waitfor != MNT_LAZY) 4276 return (0); 4277 4278 /* 4279 * Move ourselves to the back of the sync list. 4280 */ 4281 bo = &syncvp->v_bufobj; 4282 BO_LOCK(bo); 4283 vn_syncer_add_to_worklist(bo, syncdelay); 4284 BO_UNLOCK(bo); 4285 4286 /* 4287 * Walk the list of vnodes pushing all that are dirty and 4288 * not already on the sync list. 4289 */ 4290 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4291 return (0); 4292 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4293 vfs_unbusy(mp); 4294 return (0); 4295 } 4296 save = curthread_pflags_set(TDP_SYNCIO); 4297 vfs_msync(mp, MNT_NOWAIT); 4298 error = VFS_SYNC(mp, MNT_LAZY); 4299 curthread_pflags_restore(save); 4300 vn_finished_write(mp); 4301 vfs_unbusy(mp); 4302 return (error); 4303 } 4304 4305 /* 4306 * The syncer vnode is no referenced. 4307 */ 4308 static int 4309 sync_inactive(struct vop_inactive_args *ap) 4310 { 4311 4312 vgone(ap->a_vp); 4313 return (0); 4314 } 4315 4316 /* 4317 * The syncer vnode is no longer needed and is being decommissioned. 4318 * 4319 * Modifications to the worklist must be protected by sync_mtx. 4320 */ 4321 static int 4322 sync_reclaim(struct vop_reclaim_args *ap) 4323 { 4324 struct vnode *vp = ap->a_vp; 4325 struct bufobj *bo; 4326 4327 bo = &vp->v_bufobj; 4328 BO_LOCK(bo); 4329 mtx_lock(&sync_mtx); 4330 if (vp->v_mount->mnt_syncer == vp) 4331 vp->v_mount->mnt_syncer = NULL; 4332 if (bo->bo_flag & BO_ONWORKLST) { 4333 LIST_REMOVE(bo, bo_synclist); 4334 syncer_worklist_len--; 4335 sync_vnode_count--; 4336 bo->bo_flag &= ~BO_ONWORKLST; 4337 } 4338 mtx_unlock(&sync_mtx); 4339 BO_UNLOCK(bo); 4340 4341 return (0); 4342 } 4343 4344 /* 4345 * Check if vnode represents a disk device 4346 */ 4347 int 4348 vn_isdisk(struct vnode *vp, int *errp) 4349 { 4350 int error; 4351 4352 if (vp->v_type != VCHR) { 4353 error = ENOTBLK; 4354 goto out; 4355 } 4356 error = 0; 4357 dev_lock(); 4358 if (vp->v_rdev == NULL) 4359 error = ENXIO; 4360 else if (vp->v_rdev->si_devsw == NULL) 4361 error = ENXIO; 4362 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4363 error = ENOTBLK; 4364 dev_unlock(); 4365 out: 4366 if (errp != NULL) 4367 *errp = error; 4368 return (error == 0); 4369 } 4370 4371 /* 4372 * Common filesystem object access control check routine. Accepts a 4373 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4374 * and optional call-by-reference privused argument allowing vaccess() 4375 * to indicate to the caller whether privilege was used to satisfy the 4376 * request (obsoleted). Returns 0 on success, or an errno on failure. 4377 */ 4378 int 4379 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4380 accmode_t accmode, struct ucred *cred, int *privused) 4381 { 4382 accmode_t dac_granted; 4383 accmode_t priv_granted; 4384 4385 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4386 ("invalid bit in accmode")); 4387 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4388 ("VAPPEND without VWRITE")); 4389 4390 /* 4391 * Look for a normal, non-privileged way to access the file/directory 4392 * as requested. If it exists, go with that. 4393 */ 4394 4395 if (privused != NULL) 4396 *privused = 0; 4397 4398 dac_granted = 0; 4399 4400 /* Check the owner. */ 4401 if (cred->cr_uid == file_uid) { 4402 dac_granted |= VADMIN; 4403 if (file_mode & S_IXUSR) 4404 dac_granted |= VEXEC; 4405 if (file_mode & S_IRUSR) 4406 dac_granted |= VREAD; 4407 if (file_mode & S_IWUSR) 4408 dac_granted |= (VWRITE | VAPPEND); 4409 4410 if ((accmode & dac_granted) == accmode) 4411 return (0); 4412 4413 goto privcheck; 4414 } 4415 4416 /* Otherwise, check the groups (first match) */ 4417 if (groupmember(file_gid, cred)) { 4418 if (file_mode & S_IXGRP) 4419 dac_granted |= VEXEC; 4420 if (file_mode & S_IRGRP) 4421 dac_granted |= VREAD; 4422 if (file_mode & S_IWGRP) 4423 dac_granted |= (VWRITE | VAPPEND); 4424 4425 if ((accmode & dac_granted) == accmode) 4426 return (0); 4427 4428 goto privcheck; 4429 } 4430 4431 /* Otherwise, check everyone else. */ 4432 if (file_mode & S_IXOTH) 4433 dac_granted |= VEXEC; 4434 if (file_mode & S_IROTH) 4435 dac_granted |= VREAD; 4436 if (file_mode & S_IWOTH) 4437 dac_granted |= (VWRITE | VAPPEND); 4438 if ((accmode & dac_granted) == accmode) 4439 return (0); 4440 4441 privcheck: 4442 /* 4443 * Build a privilege mask to determine if the set of privileges 4444 * satisfies the requirements when combined with the granted mask 4445 * from above. For each privilege, if the privilege is required, 4446 * bitwise or the request type onto the priv_granted mask. 4447 */ 4448 priv_granted = 0; 4449 4450 if (type == VDIR) { 4451 /* 4452 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4453 * requests, instead of PRIV_VFS_EXEC. 4454 */ 4455 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4456 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 4457 priv_granted |= VEXEC; 4458 } else { 4459 /* 4460 * Ensure that at least one execute bit is on. Otherwise, 4461 * a privileged user will always succeed, and we don't want 4462 * this to happen unless the file really is executable. 4463 */ 4464 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4465 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4466 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 4467 priv_granted |= VEXEC; 4468 } 4469 4470 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4471 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 4472 priv_granted |= VREAD; 4473 4474 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4475 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 4476 priv_granted |= (VWRITE | VAPPEND); 4477 4478 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4479 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 4480 priv_granted |= VADMIN; 4481 4482 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4483 /* XXX audit: privilege used */ 4484 if (privused != NULL) 4485 *privused = 1; 4486 return (0); 4487 } 4488 4489 return ((accmode & VADMIN) ? EPERM : EACCES); 4490 } 4491 4492 /* 4493 * Credential check based on process requesting service, and per-attribute 4494 * permissions. 4495 */ 4496 int 4497 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4498 struct thread *td, accmode_t accmode) 4499 { 4500 4501 /* 4502 * Kernel-invoked always succeeds. 4503 */ 4504 if (cred == NOCRED) 4505 return (0); 4506 4507 /* 4508 * Do not allow privileged processes in jail to directly manipulate 4509 * system attributes. 4510 */ 4511 switch (attrnamespace) { 4512 case EXTATTR_NAMESPACE_SYSTEM: 4513 /* Potentially should be: return (EPERM); */ 4514 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 4515 case EXTATTR_NAMESPACE_USER: 4516 return (VOP_ACCESS(vp, accmode, cred, td)); 4517 default: 4518 return (EPERM); 4519 } 4520 } 4521 4522 #ifdef DEBUG_VFS_LOCKS 4523 /* 4524 * This only exists to suppress warnings from unlocked specfs accesses. It is 4525 * no longer ok to have an unlocked VFS. 4526 */ 4527 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4528 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4529 4530 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4531 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4532 "Drop into debugger on lock violation"); 4533 4534 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4535 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4536 0, "Check for interlock across VOPs"); 4537 4538 int vfs_badlock_print = 1; /* Print lock violations. */ 4539 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4540 0, "Print lock violations"); 4541 4542 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 4543 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 4544 0, "Print vnode details on lock violations"); 4545 4546 #ifdef KDB 4547 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4548 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4549 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4550 #endif 4551 4552 static void 4553 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4554 { 4555 4556 #ifdef KDB 4557 if (vfs_badlock_backtrace) 4558 kdb_backtrace(); 4559 #endif 4560 if (vfs_badlock_vnode) 4561 vn_printf(vp, "vnode "); 4562 if (vfs_badlock_print) 4563 printf("%s: %p %s\n", str, (void *)vp, msg); 4564 if (vfs_badlock_ddb) 4565 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4566 } 4567 4568 void 4569 assert_vi_locked(struct vnode *vp, const char *str) 4570 { 4571 4572 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4573 vfs_badlock("interlock is not locked but should be", str, vp); 4574 } 4575 4576 void 4577 assert_vi_unlocked(struct vnode *vp, const char *str) 4578 { 4579 4580 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4581 vfs_badlock("interlock is locked but should not be", str, vp); 4582 } 4583 4584 void 4585 assert_vop_locked(struct vnode *vp, const char *str) 4586 { 4587 int locked; 4588 4589 if (!IGNORE_LOCK(vp)) { 4590 locked = VOP_ISLOCKED(vp); 4591 if (locked == 0 || locked == LK_EXCLOTHER) 4592 vfs_badlock("is not locked but should be", str, vp); 4593 } 4594 } 4595 4596 void 4597 assert_vop_unlocked(struct vnode *vp, const char *str) 4598 { 4599 4600 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4601 vfs_badlock("is locked but should not be", str, vp); 4602 } 4603 4604 void 4605 assert_vop_elocked(struct vnode *vp, const char *str) 4606 { 4607 4608 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4609 vfs_badlock("is not exclusive locked but should be", str, vp); 4610 } 4611 #endif /* DEBUG_VFS_LOCKS */ 4612 4613 void 4614 vop_rename_fail(struct vop_rename_args *ap) 4615 { 4616 4617 if (ap->a_tvp != NULL) 4618 vput(ap->a_tvp); 4619 if (ap->a_tdvp == ap->a_tvp) 4620 vrele(ap->a_tdvp); 4621 else 4622 vput(ap->a_tdvp); 4623 vrele(ap->a_fdvp); 4624 vrele(ap->a_fvp); 4625 } 4626 4627 void 4628 vop_rename_pre(void *ap) 4629 { 4630 struct vop_rename_args *a = ap; 4631 4632 #ifdef DEBUG_VFS_LOCKS 4633 if (a->a_tvp) 4634 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4635 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4636 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4637 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4638 4639 /* Check the source (from). */ 4640 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4641 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4642 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4643 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4644 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4645 4646 /* Check the target. */ 4647 if (a->a_tvp) 4648 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4649 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4650 #endif 4651 if (a->a_tdvp != a->a_fdvp) 4652 vhold(a->a_fdvp); 4653 if (a->a_tvp != a->a_fvp) 4654 vhold(a->a_fvp); 4655 vhold(a->a_tdvp); 4656 if (a->a_tvp) 4657 vhold(a->a_tvp); 4658 } 4659 4660 #ifdef DEBUG_VFS_LOCKS 4661 void 4662 vop_strategy_pre(void *ap) 4663 { 4664 struct vop_strategy_args *a; 4665 struct buf *bp; 4666 4667 a = ap; 4668 bp = a->a_bp; 4669 4670 /* 4671 * Cluster ops lock their component buffers but not the IO container. 4672 */ 4673 if ((bp->b_flags & B_CLUSTER) != 0) 4674 return; 4675 4676 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4677 if (vfs_badlock_print) 4678 printf( 4679 "VOP_STRATEGY: bp is not locked but should be\n"); 4680 if (vfs_badlock_ddb) 4681 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4682 } 4683 } 4684 4685 void 4686 vop_lock_pre(void *ap) 4687 { 4688 struct vop_lock1_args *a = ap; 4689 4690 if ((a->a_flags & LK_INTERLOCK) == 0) 4691 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4692 else 4693 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 4694 } 4695 4696 void 4697 vop_lock_post(void *ap, int rc) 4698 { 4699 struct vop_lock1_args *a = ap; 4700 4701 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4702 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 4703 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 4704 } 4705 4706 void 4707 vop_unlock_pre(void *ap) 4708 { 4709 struct vop_unlock_args *a = ap; 4710 4711 if (a->a_flags & LK_INTERLOCK) 4712 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4713 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4714 } 4715 4716 void 4717 vop_unlock_post(void *ap, int rc) 4718 { 4719 struct vop_unlock_args *a = ap; 4720 4721 if (a->a_flags & LK_INTERLOCK) 4722 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4723 } 4724 #endif 4725 4726 void 4727 vop_create_post(void *ap, int rc) 4728 { 4729 struct vop_create_args *a = ap; 4730 4731 if (!rc) 4732 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4733 } 4734 4735 void 4736 vop_deleteextattr_post(void *ap, int rc) 4737 { 4738 struct vop_deleteextattr_args *a = ap; 4739 4740 if (!rc) 4741 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4742 } 4743 4744 void 4745 vop_link_post(void *ap, int rc) 4746 { 4747 struct vop_link_args *a = ap; 4748 4749 if (!rc) { 4750 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4751 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4752 } 4753 } 4754 4755 void 4756 vop_mkdir_post(void *ap, int rc) 4757 { 4758 struct vop_mkdir_args *a = ap; 4759 4760 if (!rc) 4761 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4762 } 4763 4764 void 4765 vop_mknod_post(void *ap, int rc) 4766 { 4767 struct vop_mknod_args *a = ap; 4768 4769 if (!rc) 4770 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4771 } 4772 4773 void 4774 vop_reclaim_post(void *ap, int rc) 4775 { 4776 struct vop_reclaim_args *a = ap; 4777 4778 if (!rc) 4779 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 4780 } 4781 4782 void 4783 vop_remove_post(void *ap, int rc) 4784 { 4785 struct vop_remove_args *a = ap; 4786 4787 if (!rc) { 4788 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4789 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4790 } 4791 } 4792 4793 void 4794 vop_rename_post(void *ap, int rc) 4795 { 4796 struct vop_rename_args *a = ap; 4797 long hint; 4798 4799 if (!rc) { 4800 hint = NOTE_WRITE; 4801 if (a->a_fdvp == a->a_tdvp) { 4802 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 4803 hint |= NOTE_LINK; 4804 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4805 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4806 } else { 4807 hint |= NOTE_EXTEND; 4808 if (a->a_fvp->v_type == VDIR) 4809 hint |= NOTE_LINK; 4810 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4811 4812 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 4813 a->a_tvp->v_type == VDIR) 4814 hint &= ~NOTE_LINK; 4815 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4816 } 4817 4818 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4819 if (a->a_tvp) 4820 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4821 } 4822 if (a->a_tdvp != a->a_fdvp) 4823 vdrop(a->a_fdvp); 4824 if (a->a_tvp != a->a_fvp) 4825 vdrop(a->a_fvp); 4826 vdrop(a->a_tdvp); 4827 if (a->a_tvp) 4828 vdrop(a->a_tvp); 4829 } 4830 4831 void 4832 vop_rmdir_post(void *ap, int rc) 4833 { 4834 struct vop_rmdir_args *a = ap; 4835 4836 if (!rc) { 4837 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4838 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4839 } 4840 } 4841 4842 void 4843 vop_setattr_post(void *ap, int rc) 4844 { 4845 struct vop_setattr_args *a = ap; 4846 4847 if (!rc) 4848 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4849 } 4850 4851 void 4852 vop_setextattr_post(void *ap, int rc) 4853 { 4854 struct vop_setextattr_args *a = ap; 4855 4856 if (!rc) 4857 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4858 } 4859 4860 void 4861 vop_symlink_post(void *ap, int rc) 4862 { 4863 struct vop_symlink_args *a = ap; 4864 4865 if (!rc) 4866 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4867 } 4868 4869 void 4870 vop_open_post(void *ap, int rc) 4871 { 4872 struct vop_open_args *a = ap; 4873 4874 if (!rc) 4875 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 4876 } 4877 4878 void 4879 vop_close_post(void *ap, int rc) 4880 { 4881 struct vop_close_args *a = ap; 4882 4883 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 4884 (a->a_vp->v_iflag & VI_DOOMED) == 0)) { 4885 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 4886 NOTE_CLOSE_WRITE : NOTE_CLOSE); 4887 } 4888 } 4889 4890 void 4891 vop_read_post(void *ap, int rc) 4892 { 4893 struct vop_read_args *a = ap; 4894 4895 if (!rc) 4896 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4897 } 4898 4899 void 4900 vop_readdir_post(void *ap, int rc) 4901 { 4902 struct vop_readdir_args *a = ap; 4903 4904 if (!rc) 4905 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4906 } 4907 4908 static struct knlist fs_knlist; 4909 4910 static void 4911 vfs_event_init(void *arg) 4912 { 4913 knlist_init_mtx(&fs_knlist, NULL); 4914 } 4915 /* XXX - correct order? */ 4916 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 4917 4918 void 4919 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 4920 { 4921 4922 KNOTE_UNLOCKED(&fs_knlist, event); 4923 } 4924 4925 static int filt_fsattach(struct knote *kn); 4926 static void filt_fsdetach(struct knote *kn); 4927 static int filt_fsevent(struct knote *kn, long hint); 4928 4929 struct filterops fs_filtops = { 4930 .f_isfd = 0, 4931 .f_attach = filt_fsattach, 4932 .f_detach = filt_fsdetach, 4933 .f_event = filt_fsevent 4934 }; 4935 4936 static int 4937 filt_fsattach(struct knote *kn) 4938 { 4939 4940 kn->kn_flags |= EV_CLEAR; 4941 knlist_add(&fs_knlist, kn, 0); 4942 return (0); 4943 } 4944 4945 static void 4946 filt_fsdetach(struct knote *kn) 4947 { 4948 4949 knlist_remove(&fs_knlist, kn, 0); 4950 } 4951 4952 static int 4953 filt_fsevent(struct knote *kn, long hint) 4954 { 4955 4956 kn->kn_fflags |= hint; 4957 return (kn->kn_fflags != 0); 4958 } 4959 4960 static int 4961 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 4962 { 4963 struct vfsidctl vc; 4964 int error; 4965 struct mount *mp; 4966 4967 error = SYSCTL_IN(req, &vc, sizeof(vc)); 4968 if (error) 4969 return (error); 4970 if (vc.vc_vers != VFS_CTL_VERS1) 4971 return (EINVAL); 4972 mp = vfs_getvfs(&vc.vc_fsid); 4973 if (mp == NULL) 4974 return (ENOENT); 4975 /* ensure that a specific sysctl goes to the right filesystem. */ 4976 if (strcmp(vc.vc_fstypename, "*") != 0 && 4977 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 4978 vfs_rel(mp); 4979 return (EINVAL); 4980 } 4981 VCTLTOREQ(&vc, req); 4982 error = VFS_SYSCTL(mp, vc.vc_op, req); 4983 vfs_rel(mp); 4984 return (error); 4985 } 4986 4987 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 4988 NULL, 0, sysctl_vfs_ctl, "", 4989 "Sysctl by fsid"); 4990 4991 /* 4992 * Function to initialize a va_filerev field sensibly. 4993 * XXX: Wouldn't a random number make a lot more sense ?? 4994 */ 4995 u_quad_t 4996 init_va_filerev(void) 4997 { 4998 struct bintime bt; 4999 5000 getbinuptime(&bt); 5001 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5002 } 5003 5004 static int filt_vfsread(struct knote *kn, long hint); 5005 static int filt_vfswrite(struct knote *kn, long hint); 5006 static int filt_vfsvnode(struct knote *kn, long hint); 5007 static void filt_vfsdetach(struct knote *kn); 5008 static struct filterops vfsread_filtops = { 5009 .f_isfd = 1, 5010 .f_detach = filt_vfsdetach, 5011 .f_event = filt_vfsread 5012 }; 5013 static struct filterops vfswrite_filtops = { 5014 .f_isfd = 1, 5015 .f_detach = filt_vfsdetach, 5016 .f_event = filt_vfswrite 5017 }; 5018 static struct filterops vfsvnode_filtops = { 5019 .f_isfd = 1, 5020 .f_detach = filt_vfsdetach, 5021 .f_event = filt_vfsvnode 5022 }; 5023 5024 static void 5025 vfs_knllock(void *arg) 5026 { 5027 struct vnode *vp = arg; 5028 5029 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5030 } 5031 5032 static void 5033 vfs_knlunlock(void *arg) 5034 { 5035 struct vnode *vp = arg; 5036 5037 VOP_UNLOCK(vp, 0); 5038 } 5039 5040 static void 5041 vfs_knl_assert_locked(void *arg) 5042 { 5043 #ifdef DEBUG_VFS_LOCKS 5044 struct vnode *vp = arg; 5045 5046 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5047 #endif 5048 } 5049 5050 static void 5051 vfs_knl_assert_unlocked(void *arg) 5052 { 5053 #ifdef DEBUG_VFS_LOCKS 5054 struct vnode *vp = arg; 5055 5056 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5057 #endif 5058 } 5059 5060 int 5061 vfs_kqfilter(struct vop_kqfilter_args *ap) 5062 { 5063 struct vnode *vp = ap->a_vp; 5064 struct knote *kn = ap->a_kn; 5065 struct knlist *knl; 5066 5067 switch (kn->kn_filter) { 5068 case EVFILT_READ: 5069 kn->kn_fop = &vfsread_filtops; 5070 break; 5071 case EVFILT_WRITE: 5072 kn->kn_fop = &vfswrite_filtops; 5073 break; 5074 case EVFILT_VNODE: 5075 kn->kn_fop = &vfsvnode_filtops; 5076 break; 5077 default: 5078 return (EINVAL); 5079 } 5080 5081 kn->kn_hook = (caddr_t)vp; 5082 5083 v_addpollinfo(vp); 5084 if (vp->v_pollinfo == NULL) 5085 return (ENOMEM); 5086 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5087 vhold(vp); 5088 knlist_add(knl, kn, 0); 5089 5090 return (0); 5091 } 5092 5093 /* 5094 * Detach knote from vnode 5095 */ 5096 static void 5097 filt_vfsdetach(struct knote *kn) 5098 { 5099 struct vnode *vp = (struct vnode *)kn->kn_hook; 5100 5101 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5102 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5103 vdrop(vp); 5104 } 5105 5106 /*ARGSUSED*/ 5107 static int 5108 filt_vfsread(struct knote *kn, long hint) 5109 { 5110 struct vnode *vp = (struct vnode *)kn->kn_hook; 5111 struct vattr va; 5112 int res; 5113 5114 /* 5115 * filesystem is gone, so set the EOF flag and schedule 5116 * the knote for deletion. 5117 */ 5118 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5119 VI_LOCK(vp); 5120 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5121 VI_UNLOCK(vp); 5122 return (1); 5123 } 5124 5125 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5126 return (0); 5127 5128 VI_LOCK(vp); 5129 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5130 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5131 VI_UNLOCK(vp); 5132 return (res); 5133 } 5134 5135 /*ARGSUSED*/ 5136 static int 5137 filt_vfswrite(struct knote *kn, long hint) 5138 { 5139 struct vnode *vp = (struct vnode *)kn->kn_hook; 5140 5141 VI_LOCK(vp); 5142 5143 /* 5144 * filesystem is gone, so set the EOF flag and schedule 5145 * the knote for deletion. 5146 */ 5147 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5148 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5149 5150 kn->kn_data = 0; 5151 VI_UNLOCK(vp); 5152 return (1); 5153 } 5154 5155 static int 5156 filt_vfsvnode(struct knote *kn, long hint) 5157 { 5158 struct vnode *vp = (struct vnode *)kn->kn_hook; 5159 int res; 5160 5161 VI_LOCK(vp); 5162 if (kn->kn_sfflags & hint) 5163 kn->kn_fflags |= hint; 5164 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5165 kn->kn_flags |= EV_EOF; 5166 VI_UNLOCK(vp); 5167 return (1); 5168 } 5169 res = (kn->kn_fflags != 0); 5170 VI_UNLOCK(vp); 5171 return (res); 5172 } 5173 5174 int 5175 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5176 { 5177 int error; 5178 5179 if (dp->d_reclen > ap->a_uio->uio_resid) 5180 return (ENAMETOOLONG); 5181 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5182 if (error) { 5183 if (ap->a_ncookies != NULL) { 5184 if (ap->a_cookies != NULL) 5185 free(ap->a_cookies, M_TEMP); 5186 ap->a_cookies = NULL; 5187 *ap->a_ncookies = 0; 5188 } 5189 return (error); 5190 } 5191 if (ap->a_ncookies == NULL) 5192 return (0); 5193 5194 KASSERT(ap->a_cookies, 5195 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5196 5197 *ap->a_cookies = realloc(*ap->a_cookies, 5198 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5199 (*ap->a_cookies)[*ap->a_ncookies] = off; 5200 *ap->a_ncookies += 1; 5201 return (0); 5202 } 5203 5204 /* 5205 * Mark for update the access time of the file if the filesystem 5206 * supports VOP_MARKATIME. This functionality is used by execve and 5207 * mmap, so we want to avoid the I/O implied by directly setting 5208 * va_atime for the sake of efficiency. 5209 */ 5210 void 5211 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5212 { 5213 struct mount *mp; 5214 5215 mp = vp->v_mount; 5216 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5217 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5218 (void)VOP_MARKATIME(vp); 5219 } 5220 5221 /* 5222 * The purpose of this routine is to remove granularity from accmode_t, 5223 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5224 * VADMIN and VAPPEND. 5225 * 5226 * If it returns 0, the caller is supposed to continue with the usual 5227 * access checks using 'accmode' as modified by this routine. If it 5228 * returns nonzero value, the caller is supposed to return that value 5229 * as errno. 5230 * 5231 * Note that after this routine runs, accmode may be zero. 5232 */ 5233 int 5234 vfs_unixify_accmode(accmode_t *accmode) 5235 { 5236 /* 5237 * There is no way to specify explicit "deny" rule using 5238 * file mode or POSIX.1e ACLs. 5239 */ 5240 if (*accmode & VEXPLICIT_DENY) { 5241 *accmode = 0; 5242 return (0); 5243 } 5244 5245 /* 5246 * None of these can be translated into usual access bits. 5247 * Also, the common case for NFSv4 ACLs is to not contain 5248 * either of these bits. Caller should check for VWRITE 5249 * on the containing directory instead. 5250 */ 5251 if (*accmode & (VDELETE_CHILD | VDELETE)) 5252 return (EPERM); 5253 5254 if (*accmode & VADMIN_PERMS) { 5255 *accmode &= ~VADMIN_PERMS; 5256 *accmode |= VADMIN; 5257 } 5258 5259 /* 5260 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 5261 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 5262 */ 5263 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 5264 5265 return (0); 5266 } 5267 5268 /* 5269 * These are helper functions for filesystems to traverse all 5270 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 5271 * 5272 * This interface replaces MNT_VNODE_FOREACH. 5273 */ 5274 5275 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 5276 5277 struct vnode * 5278 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5279 { 5280 struct vnode *vp; 5281 5282 if (should_yield()) 5283 kern_yield(PRI_USER); 5284 MNT_ILOCK(mp); 5285 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5286 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 5287 while (vp != NULL && (vp->v_type == VMARKER || 5288 (vp->v_iflag & VI_DOOMED) != 0)) 5289 vp = TAILQ_NEXT(vp, v_nmntvnodes); 5290 5291 /* Check if we are done */ 5292 if (vp == NULL) { 5293 __mnt_vnode_markerfree_all(mvp, mp); 5294 /* MNT_IUNLOCK(mp); -- done in above function */ 5295 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5296 return (NULL); 5297 } 5298 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5299 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5300 VI_LOCK(vp); 5301 MNT_IUNLOCK(mp); 5302 return (vp); 5303 } 5304 5305 struct vnode * 5306 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5307 { 5308 struct vnode *vp; 5309 5310 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5311 MNT_ILOCK(mp); 5312 MNT_REF(mp); 5313 (*mvp)->v_type = VMARKER; 5314 5315 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 5316 while (vp != NULL && (vp->v_type == VMARKER || 5317 (vp->v_iflag & VI_DOOMED) != 0)) 5318 vp = TAILQ_NEXT(vp, v_nmntvnodes); 5319 5320 /* Check if we are done */ 5321 if (vp == NULL) { 5322 MNT_REL(mp); 5323 MNT_IUNLOCK(mp); 5324 free(*mvp, M_VNODE_MARKER); 5325 *mvp = NULL; 5326 return (NULL); 5327 } 5328 (*mvp)->v_mount = mp; 5329 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5330 VI_LOCK(vp); 5331 MNT_IUNLOCK(mp); 5332 return (vp); 5333 } 5334 5335 5336 void 5337 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5338 { 5339 5340 if (*mvp == NULL) { 5341 MNT_IUNLOCK(mp); 5342 return; 5343 } 5344 5345 mtx_assert(MNT_MTX(mp), MA_OWNED); 5346 5347 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5348 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5349 MNT_REL(mp); 5350 MNT_IUNLOCK(mp); 5351 free(*mvp, M_VNODE_MARKER); 5352 *mvp = NULL; 5353 } 5354 5355 /* 5356 * These are helper functions for filesystems to traverse their 5357 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5358 */ 5359 static void 5360 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5361 { 5362 5363 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5364 5365 MNT_ILOCK(mp); 5366 MNT_REL(mp); 5367 MNT_IUNLOCK(mp); 5368 free(*mvp, M_VNODE_MARKER); 5369 *mvp = NULL; 5370 } 5371 5372 /* 5373 * Relock the mp mount vnode list lock with the vp vnode interlock in the 5374 * conventional lock order during mnt_vnode_next_active iteration. 5375 * 5376 * On entry, the mount vnode list lock is held and the vnode interlock is not. 5377 * The list lock is dropped and reacquired. On success, both locks are held. 5378 * On failure, the mount vnode list lock is held but the vnode interlock is 5379 * not, and the procedure may have yielded. 5380 */ 5381 static bool 5382 mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp, 5383 struct vnode *vp) 5384 { 5385 const struct vnode *tmp; 5386 bool held, ret; 5387 5388 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 5389 TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp, 5390 ("%s: bad marker", __func__)); 5391 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 5392 ("%s: inappropriate vnode", __func__)); 5393 ASSERT_VI_UNLOCKED(vp, __func__); 5394 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5395 5396 ret = false; 5397 5398 TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist); 5399 TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist); 5400 5401 /* 5402 * Use a hold to prevent vp from disappearing while the mount vnode 5403 * list lock is dropped and reacquired. Normally a hold would be 5404 * acquired with vhold(), but that might try to acquire the vnode 5405 * interlock, which would be a LOR with the mount vnode list lock. 5406 */ 5407 held = vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt); 5408 mtx_unlock(&mp->mnt_listmtx); 5409 if (!held) 5410 goto abort; 5411 VI_LOCK(vp); 5412 if (!vfs_refcount_release_if_not_last(&vp->v_holdcnt)) { 5413 vdropl(vp); 5414 goto abort; 5415 } 5416 mtx_lock(&mp->mnt_listmtx); 5417 5418 /* 5419 * Determine whether the vnode is still the next one after the marker, 5420 * excepting any other markers. If the vnode has not been doomed by 5421 * vgone() then the hold should have ensured that it remained on the 5422 * active list. If it has been doomed but is still on the active list, 5423 * don't abort, but rather skip over it (avoid spinning on doomed 5424 * vnodes). 5425 */ 5426 tmp = mvp; 5427 do { 5428 tmp = TAILQ_NEXT(tmp, v_actfreelist); 5429 } while (tmp != NULL && tmp->v_type == VMARKER); 5430 if (tmp != vp) { 5431 mtx_unlock(&mp->mnt_listmtx); 5432 VI_UNLOCK(vp); 5433 goto abort; 5434 } 5435 5436 ret = true; 5437 goto out; 5438 abort: 5439 maybe_yield(); 5440 mtx_lock(&mp->mnt_listmtx); 5441 out: 5442 if (ret) 5443 ASSERT_VI_LOCKED(vp, __func__); 5444 else 5445 ASSERT_VI_UNLOCKED(vp, __func__); 5446 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5447 return (ret); 5448 } 5449 5450 static struct vnode * 5451 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5452 { 5453 struct vnode *vp, *nvp; 5454 5455 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5456 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5457 restart: 5458 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5459 while (vp != NULL) { 5460 if (vp->v_type == VMARKER) { 5461 vp = TAILQ_NEXT(vp, v_actfreelist); 5462 continue; 5463 } 5464 /* 5465 * Try-lock because this is the wrong lock order. If that does 5466 * not succeed, drop the mount vnode list lock and try to 5467 * reacquire it and the vnode interlock in the right order. 5468 */ 5469 if (!VI_TRYLOCK(vp) && 5470 !mnt_vnode_next_active_relock(*mvp, mp, vp)) 5471 goto restart; 5472 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5473 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5474 ("alien vnode on the active list %p %p", vp, mp)); 5475 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) 5476 break; 5477 nvp = TAILQ_NEXT(vp, v_actfreelist); 5478 VI_UNLOCK(vp); 5479 vp = nvp; 5480 } 5481 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5482 5483 /* Check if we are done */ 5484 if (vp == NULL) { 5485 mtx_unlock(&mp->mnt_listmtx); 5486 mnt_vnode_markerfree_active(mvp, mp); 5487 return (NULL); 5488 } 5489 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 5490 mtx_unlock(&mp->mnt_listmtx); 5491 ASSERT_VI_LOCKED(vp, "active iter"); 5492 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 5493 return (vp); 5494 } 5495 5496 struct vnode * 5497 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5498 { 5499 5500 if (should_yield()) 5501 kern_yield(PRI_USER); 5502 mtx_lock(&mp->mnt_listmtx); 5503 return (mnt_vnode_next_active(mvp, mp)); 5504 } 5505 5506 struct vnode * 5507 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 5508 { 5509 struct vnode *vp; 5510 5511 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5512 MNT_ILOCK(mp); 5513 MNT_REF(mp); 5514 MNT_IUNLOCK(mp); 5515 (*mvp)->v_type = VMARKER; 5516 (*mvp)->v_mount = mp; 5517 5518 mtx_lock(&mp->mnt_listmtx); 5519 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 5520 if (vp == NULL) { 5521 mtx_unlock(&mp->mnt_listmtx); 5522 mnt_vnode_markerfree_active(mvp, mp); 5523 return (NULL); 5524 } 5525 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5526 return (mnt_vnode_next_active(mvp, mp)); 5527 } 5528 5529 void 5530 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5531 { 5532 5533 if (*mvp == NULL) 5534 return; 5535 5536 mtx_lock(&mp->mnt_listmtx); 5537 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5538 mtx_unlock(&mp->mnt_listmtx); 5539 mnt_vnode_markerfree_active(mvp, mp); 5540 } 5541