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 if (nbp != NULL) { 1750 lblkno = nbp->b_lblkno; 1751 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1752 } 1753 retval = EAGAIN; 1754 error = BUF_TIMELOCK(bp, 1755 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1756 "flushbuf", slpflag, slptimeo); 1757 if (error) { 1758 BO_LOCK(bo); 1759 return (error != ENOLCK ? error : EAGAIN); 1760 } 1761 KASSERT(bp->b_bufobj == bo, 1762 ("bp %p wrong b_bufobj %p should be %p", 1763 bp, bp->b_bufobj, bo)); 1764 /* 1765 * XXX Since there are no node locks for NFS, I 1766 * believe there is a slight chance that a delayed 1767 * write will occur while sleeping just above, so 1768 * check for it. 1769 */ 1770 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1771 (flags & V_SAVE)) { 1772 bremfree(bp); 1773 bp->b_flags |= B_ASYNC; 1774 bwrite(bp); 1775 BO_LOCK(bo); 1776 return (EAGAIN); /* XXX: why not loop ? */ 1777 } 1778 bremfree(bp); 1779 bp->b_flags |= (B_INVAL | B_RELBUF); 1780 bp->b_flags &= ~B_ASYNC; 1781 brelse(bp); 1782 BO_LOCK(bo); 1783 if (nbp == NULL) 1784 break; 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 VNASSERT(vp->v_mount != NULL, vp, 2865 ("_vhold: vnode not on per mount vnode list")); 2866 mp = vp->v_mount; 2867 mtx_lock(&mp->mnt_listmtx); 2868 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { 2869 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 2870 mp->mnt_tmpfreevnodelistsize--; 2871 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 2872 } else { 2873 mtx_lock(&vnode_free_list_mtx); 2874 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 2875 freevnodes--; 2876 mtx_unlock(&vnode_free_list_mtx); 2877 } 2878 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 2879 ("Activating already active vnode")); 2880 vp->v_iflag &= ~VI_FREE; 2881 vp->v_iflag |= VI_ACTIVE; 2882 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 2883 mp->mnt_activevnodelistsize++; 2884 mtx_unlock(&mp->mnt_listmtx); 2885 refcount_acquire(&vp->v_holdcnt); 2886 if (!locked) 2887 VI_UNLOCK(vp); 2888 } 2889 2890 /* 2891 * Drop the hold count of the vnode. If this is the last reference to 2892 * the vnode we place it on the free list unless it has been vgone'd 2893 * (marked VI_DOOMED) in which case we will free it. 2894 * 2895 * Because the vnode vm object keeps a hold reference on the vnode if 2896 * there is at least one resident non-cached page, the vnode cannot 2897 * leave the active list without the page cleanup done. 2898 */ 2899 void 2900 _vdrop(struct vnode *vp, bool locked) 2901 { 2902 struct bufobj *bo; 2903 struct mount *mp; 2904 int active; 2905 2906 if (locked) 2907 ASSERT_VI_LOCKED(vp, __func__); 2908 else 2909 ASSERT_VI_UNLOCKED(vp, __func__); 2910 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2911 if ((int)vp->v_holdcnt <= 0) 2912 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2913 if (vfs_refcount_release_if_not_last(&vp->v_holdcnt)) { 2914 if (locked) 2915 VI_UNLOCK(vp); 2916 return; 2917 } 2918 2919 if (!locked) 2920 VI_LOCK(vp); 2921 if (refcount_release(&vp->v_holdcnt) == 0) { 2922 VI_UNLOCK(vp); 2923 return; 2924 } 2925 if ((vp->v_iflag & VI_DOOMED) == 0) { 2926 /* 2927 * Mark a vnode as free: remove it from its active list 2928 * and put it up for recycling on the freelist. 2929 */ 2930 VNASSERT(vp->v_op != NULL, vp, 2931 ("vdropl: vnode already reclaimed.")); 2932 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2933 ("vnode already free")); 2934 VNASSERT(vp->v_holdcnt == 0, vp, 2935 ("vdropl: freeing when we shouldn't")); 2936 active = vp->v_iflag & VI_ACTIVE; 2937 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2938 vp->v_iflag &= ~VI_ACTIVE; 2939 mp = vp->v_mount; 2940 if (mp != NULL) { 2941 mtx_lock(&mp->mnt_listmtx); 2942 if (active) { 2943 TAILQ_REMOVE(&mp->mnt_activevnodelist, 2944 vp, v_actfreelist); 2945 mp->mnt_activevnodelistsize--; 2946 } 2947 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, 2948 vp, v_actfreelist); 2949 mp->mnt_tmpfreevnodelistsize++; 2950 vp->v_iflag |= VI_FREE; 2951 vp->v_mflag |= VMP_TMPMNTFREELIST; 2952 VI_UNLOCK(vp); 2953 if (mp->mnt_tmpfreevnodelistsize >= 2954 mnt_free_list_batch) 2955 vnlru_return_batch_locked(mp); 2956 mtx_unlock(&mp->mnt_listmtx); 2957 } else { 2958 VNASSERT(active == 0, vp, 2959 ("vdropl: active vnode not on per mount " 2960 "vnode list")); 2961 mtx_lock(&vnode_free_list_mtx); 2962 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 2963 v_actfreelist); 2964 freevnodes++; 2965 vp->v_iflag |= VI_FREE; 2966 VI_UNLOCK(vp); 2967 mtx_unlock(&vnode_free_list_mtx); 2968 } 2969 } else { 2970 VI_UNLOCK(vp); 2971 counter_u64_add(free_owe_inact, 1); 2972 } 2973 return; 2974 } 2975 /* 2976 * The vnode has been marked for destruction, so free it. 2977 * 2978 * The vnode will be returned to the zone where it will 2979 * normally remain until it is needed for another vnode. We 2980 * need to cleanup (or verify that the cleanup has already 2981 * been done) any residual data left from its current use 2982 * so as not to contaminate the freshly allocated vnode. 2983 */ 2984 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 2985 atomic_subtract_long(&numvnodes, 1); 2986 bo = &vp->v_bufobj; 2987 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2988 ("cleaned vnode still on the free list.")); 2989 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 2990 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 2991 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 2992 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 2993 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 2994 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 2995 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 2996 ("clean blk trie not empty")); 2997 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 2998 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 2999 ("dirty blk trie not empty")); 3000 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 3001 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 3002 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 3003 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 3004 ("Dangling rangelock waiters")); 3005 VI_UNLOCK(vp); 3006 #ifdef MAC 3007 mac_vnode_destroy(vp); 3008 #endif 3009 if (vp->v_pollinfo != NULL) { 3010 destroy_vpollinfo(vp->v_pollinfo); 3011 vp->v_pollinfo = NULL; 3012 } 3013 #ifdef INVARIANTS 3014 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 3015 vp->v_op = NULL; 3016 #endif 3017 vp->v_mountedhere = NULL; 3018 vp->v_unpcb = NULL; 3019 vp->v_rdev = NULL; 3020 vp->v_fifoinfo = NULL; 3021 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 3022 vp->v_iflag = 0; 3023 vp->v_vflag = 0; 3024 bo->bo_flag = 0; 3025 uma_zfree(vnode_zone, vp); 3026 } 3027 3028 /* 3029 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3030 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3031 * OWEINACT tracks whether a vnode missed a call to inactive due to a 3032 * failed lock upgrade. 3033 */ 3034 void 3035 vinactive(struct vnode *vp, struct thread *td) 3036 { 3037 struct vm_object *obj; 3038 3039 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3040 ASSERT_VI_LOCKED(vp, "vinactive"); 3041 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3042 ("vinactive: recursed on VI_DOINGINACT")); 3043 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3044 vp->v_iflag |= VI_DOINGINACT; 3045 vp->v_iflag &= ~VI_OWEINACT; 3046 VI_UNLOCK(vp); 3047 /* 3048 * Before moving off the active list, we must be sure that any 3049 * modified pages are converted into the vnode's dirty 3050 * buffers, since these will no longer be checked once the 3051 * vnode is on the inactive list. 3052 * 3053 * The write-out of the dirty pages is asynchronous. At the 3054 * point that VOP_INACTIVE() is called, there could still be 3055 * pending I/O and dirty pages in the object. 3056 */ 3057 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && 3058 (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { 3059 VM_OBJECT_WLOCK(obj); 3060 vm_object_page_clean(obj, 0, 0, 0); 3061 VM_OBJECT_WUNLOCK(obj); 3062 } 3063 VOP_INACTIVE(vp, td); 3064 VI_LOCK(vp); 3065 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3066 ("vinactive: lost VI_DOINGINACT")); 3067 vp->v_iflag &= ~VI_DOINGINACT; 3068 } 3069 3070 /* 3071 * Remove any vnodes in the vnode table belonging to mount point mp. 3072 * 3073 * If FORCECLOSE is not specified, there should not be any active ones, 3074 * return error if any are found (nb: this is a user error, not a 3075 * system error). If FORCECLOSE is specified, detach any active vnodes 3076 * that are found. 3077 * 3078 * If WRITECLOSE is set, only flush out regular file vnodes open for 3079 * writing. 3080 * 3081 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3082 * 3083 * `rootrefs' specifies the base reference count for the root vnode 3084 * of this filesystem. The root vnode is considered busy if its 3085 * v_usecount exceeds this value. On a successful return, vflush(, td) 3086 * will call vrele() on the root vnode exactly rootrefs times. 3087 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3088 * be zero. 3089 */ 3090 #ifdef DIAGNOSTIC 3091 static int busyprt = 0; /* print out busy vnodes */ 3092 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3093 #endif 3094 3095 int 3096 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3097 { 3098 struct vnode *vp, *mvp, *rootvp = NULL; 3099 struct vattr vattr; 3100 int busy = 0, error; 3101 3102 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3103 rootrefs, flags); 3104 if (rootrefs > 0) { 3105 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3106 ("vflush: bad args")); 3107 /* 3108 * Get the filesystem root vnode. We can vput() it 3109 * immediately, since with rootrefs > 0, it won't go away. 3110 */ 3111 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3112 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3113 __func__, error); 3114 return (error); 3115 } 3116 vput(rootvp); 3117 } 3118 loop: 3119 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3120 vholdl(vp); 3121 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3122 if (error) { 3123 vdrop(vp); 3124 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3125 goto loop; 3126 } 3127 /* 3128 * Skip over a vnodes marked VV_SYSTEM. 3129 */ 3130 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3131 VOP_UNLOCK(vp, 0); 3132 vdrop(vp); 3133 continue; 3134 } 3135 /* 3136 * If WRITECLOSE is set, flush out unlinked but still open 3137 * files (even if open only for reading) and regular file 3138 * vnodes open for writing. 3139 */ 3140 if (flags & WRITECLOSE) { 3141 if (vp->v_object != NULL) { 3142 VM_OBJECT_WLOCK(vp->v_object); 3143 vm_object_page_clean(vp->v_object, 0, 0, 0); 3144 VM_OBJECT_WUNLOCK(vp->v_object); 3145 } 3146 error = VOP_FSYNC(vp, MNT_WAIT, td); 3147 if (error != 0) { 3148 VOP_UNLOCK(vp, 0); 3149 vdrop(vp); 3150 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3151 return (error); 3152 } 3153 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3154 VI_LOCK(vp); 3155 3156 if ((vp->v_type == VNON || 3157 (error == 0 && vattr.va_nlink > 0)) && 3158 (vp->v_writecount == 0 || vp->v_type != VREG)) { 3159 VOP_UNLOCK(vp, 0); 3160 vdropl(vp); 3161 continue; 3162 } 3163 } else 3164 VI_LOCK(vp); 3165 /* 3166 * With v_usecount == 0, all we need to do is clear out the 3167 * vnode data structures and we are done. 3168 * 3169 * If FORCECLOSE is set, forcibly close the vnode. 3170 */ 3171 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3172 vgonel(vp); 3173 } else { 3174 busy++; 3175 #ifdef DIAGNOSTIC 3176 if (busyprt) 3177 vn_printf(vp, "vflush: busy vnode "); 3178 #endif 3179 } 3180 VOP_UNLOCK(vp, 0); 3181 vdropl(vp); 3182 } 3183 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3184 /* 3185 * If just the root vnode is busy, and if its refcount 3186 * is equal to `rootrefs', then go ahead and kill it. 3187 */ 3188 VI_LOCK(rootvp); 3189 KASSERT(busy > 0, ("vflush: not busy")); 3190 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3191 ("vflush: usecount %d < rootrefs %d", 3192 rootvp->v_usecount, rootrefs)); 3193 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3194 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3195 vgone(rootvp); 3196 VOP_UNLOCK(rootvp, 0); 3197 busy = 0; 3198 } else 3199 VI_UNLOCK(rootvp); 3200 } 3201 if (busy) { 3202 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3203 busy); 3204 return (EBUSY); 3205 } 3206 for (; rootrefs > 0; rootrefs--) 3207 vrele(rootvp); 3208 return (0); 3209 } 3210 3211 /* 3212 * Recycle an unused vnode to the front of the free list. 3213 */ 3214 int 3215 vrecycle(struct vnode *vp) 3216 { 3217 int recycled; 3218 3219 VI_LOCK(vp); 3220 recycled = vrecyclel(vp); 3221 VI_UNLOCK(vp); 3222 return (recycled); 3223 } 3224 3225 /* 3226 * vrecycle, with the vp interlock held. 3227 */ 3228 int 3229 vrecyclel(struct vnode *vp) 3230 { 3231 int recycled; 3232 3233 ASSERT_VOP_ELOCKED(vp, __func__); 3234 ASSERT_VI_LOCKED(vp, __func__); 3235 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3236 recycled = 0; 3237 if (vp->v_usecount == 0) { 3238 recycled = 1; 3239 vgonel(vp); 3240 } 3241 return (recycled); 3242 } 3243 3244 /* 3245 * Eliminate all activity associated with a vnode 3246 * in preparation for reuse. 3247 */ 3248 void 3249 vgone(struct vnode *vp) 3250 { 3251 VI_LOCK(vp); 3252 vgonel(vp); 3253 VI_UNLOCK(vp); 3254 } 3255 3256 static void 3257 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3258 struct vnode *lowervp __unused) 3259 { 3260 } 3261 3262 /* 3263 * Notify upper mounts about reclaimed or unlinked vnode. 3264 */ 3265 void 3266 vfs_notify_upper(struct vnode *vp, int event) 3267 { 3268 static struct vfsops vgonel_vfsops = { 3269 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3270 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3271 }; 3272 struct mount *mp, *ump, *mmp; 3273 3274 mp = vp->v_mount; 3275 if (mp == NULL) 3276 return; 3277 3278 MNT_ILOCK(mp); 3279 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3280 goto unlock; 3281 MNT_IUNLOCK(mp); 3282 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3283 mmp->mnt_op = &vgonel_vfsops; 3284 mmp->mnt_kern_flag |= MNTK_MARKER; 3285 MNT_ILOCK(mp); 3286 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3287 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3288 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3289 ump = TAILQ_NEXT(ump, mnt_upper_link); 3290 continue; 3291 } 3292 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3293 MNT_IUNLOCK(mp); 3294 switch (event) { 3295 case VFS_NOTIFY_UPPER_RECLAIM: 3296 VFS_RECLAIM_LOWERVP(ump, vp); 3297 break; 3298 case VFS_NOTIFY_UPPER_UNLINK: 3299 VFS_UNLINK_LOWERVP(ump, vp); 3300 break; 3301 default: 3302 KASSERT(0, ("invalid event %d", event)); 3303 break; 3304 } 3305 MNT_ILOCK(mp); 3306 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3307 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3308 } 3309 free(mmp, M_TEMP); 3310 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3311 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3312 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3313 wakeup(&mp->mnt_uppers); 3314 } 3315 unlock: 3316 MNT_IUNLOCK(mp); 3317 } 3318 3319 /* 3320 * vgone, with the vp interlock held. 3321 */ 3322 static void 3323 vgonel(struct vnode *vp) 3324 { 3325 struct thread *td; 3326 int oweinact; 3327 int active; 3328 struct mount *mp; 3329 3330 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3331 ASSERT_VI_LOCKED(vp, "vgonel"); 3332 VNASSERT(vp->v_holdcnt, vp, 3333 ("vgonel: vp %p has no reference.", vp)); 3334 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3335 td = curthread; 3336 3337 /* 3338 * Don't vgonel if we're already doomed. 3339 */ 3340 if (vp->v_iflag & VI_DOOMED) 3341 return; 3342 vp->v_iflag |= VI_DOOMED; 3343 3344 /* 3345 * Check to see if the vnode is in use. If so, we have to call 3346 * VOP_CLOSE() and VOP_INACTIVE(). 3347 */ 3348 active = vp->v_usecount; 3349 oweinact = (vp->v_iflag & VI_OWEINACT); 3350 VI_UNLOCK(vp); 3351 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3352 3353 /* 3354 * If purging an active vnode, it must be closed and 3355 * deactivated before being reclaimed. 3356 */ 3357 if (active) 3358 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3359 if (oweinact || active) { 3360 VI_LOCK(vp); 3361 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3362 vinactive(vp, td); 3363 VI_UNLOCK(vp); 3364 } 3365 if (vp->v_type == VSOCK) 3366 vfs_unp_reclaim(vp); 3367 3368 /* 3369 * Clean out any buffers associated with the vnode. 3370 * If the flush fails, just toss the buffers. 3371 */ 3372 mp = NULL; 3373 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3374 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3375 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3376 while (vinvalbuf(vp, 0, 0, 0) != 0) 3377 ; 3378 } 3379 3380 BO_LOCK(&vp->v_bufobj); 3381 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3382 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3383 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3384 vp->v_bufobj.bo_clean.bv_cnt == 0, 3385 ("vp %p bufobj not invalidated", vp)); 3386 3387 /* 3388 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate() 3389 * after the object's page queue is flushed. 3390 */ 3391 if (vp->v_bufobj.bo_object == NULL) 3392 vp->v_bufobj.bo_flag |= BO_DEAD; 3393 BO_UNLOCK(&vp->v_bufobj); 3394 3395 /* 3396 * Reclaim the vnode. 3397 */ 3398 if (VOP_RECLAIM(vp, td)) 3399 panic("vgone: cannot reclaim"); 3400 if (mp != NULL) 3401 vn_finished_secondary_write(mp); 3402 VNASSERT(vp->v_object == NULL, vp, 3403 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3404 /* 3405 * Clear the advisory locks and wake up waiting threads. 3406 */ 3407 (void)VOP_ADVLOCKPURGE(vp); 3408 vp->v_lockf = NULL; 3409 /* 3410 * Delete from old mount point vnode list. 3411 */ 3412 delmntque(vp); 3413 cache_purge(vp); 3414 /* 3415 * Done with purge, reset to the standard lock and invalidate 3416 * the vnode. 3417 */ 3418 VI_LOCK(vp); 3419 vp->v_vnlock = &vp->v_lock; 3420 vp->v_op = &dead_vnodeops; 3421 vp->v_tag = "none"; 3422 vp->v_type = VBAD; 3423 } 3424 3425 /* 3426 * Calculate the total number of references to a special device. 3427 */ 3428 int 3429 vcount(struct vnode *vp) 3430 { 3431 int count; 3432 3433 dev_lock(); 3434 count = vp->v_rdev->si_usecount; 3435 dev_unlock(); 3436 return (count); 3437 } 3438 3439 /* 3440 * Same as above, but using the struct cdev *as argument 3441 */ 3442 int 3443 count_dev(struct cdev *dev) 3444 { 3445 int count; 3446 3447 dev_lock(); 3448 count = dev->si_usecount; 3449 dev_unlock(); 3450 return(count); 3451 } 3452 3453 /* 3454 * Print out a description of a vnode. 3455 */ 3456 static char *typename[] = 3457 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3458 "VMARKER"}; 3459 3460 void 3461 vn_printf(struct vnode *vp, const char *fmt, ...) 3462 { 3463 va_list ap; 3464 char buf[256], buf2[16]; 3465 u_long flags; 3466 3467 va_start(ap, fmt); 3468 vprintf(fmt, ap); 3469 va_end(ap); 3470 printf("%p: ", (void *)vp); 3471 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3472 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 3473 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 3474 buf[0] = '\0'; 3475 buf[1] = '\0'; 3476 if (vp->v_vflag & VV_ROOT) 3477 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3478 if (vp->v_vflag & VV_ISTTY) 3479 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3480 if (vp->v_vflag & VV_NOSYNC) 3481 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3482 if (vp->v_vflag & VV_ETERNALDEV) 3483 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3484 if (vp->v_vflag & VV_CACHEDLABEL) 3485 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3486 if (vp->v_vflag & VV_TEXT) 3487 strlcat(buf, "|VV_TEXT", sizeof(buf)); 3488 if (vp->v_vflag & VV_COPYONWRITE) 3489 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3490 if (vp->v_vflag & VV_SYSTEM) 3491 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3492 if (vp->v_vflag & VV_PROCDEP) 3493 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3494 if (vp->v_vflag & VV_NOKNOTE) 3495 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3496 if (vp->v_vflag & VV_DELETED) 3497 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3498 if (vp->v_vflag & VV_MD) 3499 strlcat(buf, "|VV_MD", sizeof(buf)); 3500 if (vp->v_vflag & VV_FORCEINSMQ) 3501 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3502 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3503 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3504 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3505 if (flags != 0) { 3506 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3507 strlcat(buf, buf2, sizeof(buf)); 3508 } 3509 if (vp->v_iflag & VI_MOUNT) 3510 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3511 if (vp->v_iflag & VI_DOOMED) 3512 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 3513 if (vp->v_iflag & VI_FREE) 3514 strlcat(buf, "|VI_FREE", sizeof(buf)); 3515 if (vp->v_iflag & VI_ACTIVE) 3516 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3517 if (vp->v_iflag & VI_DOINGINACT) 3518 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3519 if (vp->v_iflag & VI_OWEINACT) 3520 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3521 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | 3522 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT); 3523 if (flags != 0) { 3524 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3525 strlcat(buf, buf2, sizeof(buf)); 3526 } 3527 printf(" flags (%s)\n", buf + 1); 3528 if (mtx_owned(VI_MTX(vp))) 3529 printf(" VI_LOCKed"); 3530 if (vp->v_object != NULL) 3531 printf(" v_object %p ref %d pages %d " 3532 "cleanbuf %d dirtybuf %d\n", 3533 vp->v_object, vp->v_object->ref_count, 3534 vp->v_object->resident_page_count, 3535 vp->v_bufobj.bo_clean.bv_cnt, 3536 vp->v_bufobj.bo_dirty.bv_cnt); 3537 printf(" "); 3538 lockmgr_printinfo(vp->v_vnlock); 3539 if (vp->v_data != NULL) 3540 VOP_PRINT(vp); 3541 } 3542 3543 #ifdef DDB 3544 /* 3545 * List all of the locked vnodes in the system. 3546 * Called when debugging the kernel. 3547 */ 3548 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3549 { 3550 struct mount *mp; 3551 struct vnode *vp; 3552 3553 /* 3554 * Note: because this is DDB, we can't obey the locking semantics 3555 * for these structures, which means we could catch an inconsistent 3556 * state and dereference a nasty pointer. Not much to be done 3557 * about that. 3558 */ 3559 db_printf("Locked vnodes\n"); 3560 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3561 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3562 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3563 vn_printf(vp, "vnode "); 3564 } 3565 } 3566 } 3567 3568 /* 3569 * Show details about the given vnode. 3570 */ 3571 DB_SHOW_COMMAND(vnode, db_show_vnode) 3572 { 3573 struct vnode *vp; 3574 3575 if (!have_addr) 3576 return; 3577 vp = (struct vnode *)addr; 3578 vn_printf(vp, "vnode "); 3579 } 3580 3581 /* 3582 * Show details about the given mount point. 3583 */ 3584 DB_SHOW_COMMAND(mount, db_show_mount) 3585 { 3586 struct mount *mp; 3587 struct vfsopt *opt; 3588 struct statfs *sp; 3589 struct vnode *vp; 3590 char buf[512]; 3591 uint64_t mflags; 3592 u_int flags; 3593 3594 if (!have_addr) { 3595 /* No address given, print short info about all mount points. */ 3596 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3597 db_printf("%p %s on %s (%s)\n", mp, 3598 mp->mnt_stat.f_mntfromname, 3599 mp->mnt_stat.f_mntonname, 3600 mp->mnt_stat.f_fstypename); 3601 if (db_pager_quit) 3602 break; 3603 } 3604 db_printf("\nMore info: show mount <addr>\n"); 3605 return; 3606 } 3607 3608 mp = (struct mount *)addr; 3609 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3610 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3611 3612 buf[0] = '\0'; 3613 mflags = mp->mnt_flag; 3614 #define MNT_FLAG(flag) do { \ 3615 if (mflags & (flag)) { \ 3616 if (buf[0] != '\0') \ 3617 strlcat(buf, ", ", sizeof(buf)); \ 3618 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3619 mflags &= ~(flag); \ 3620 } \ 3621 } while (0) 3622 MNT_FLAG(MNT_RDONLY); 3623 MNT_FLAG(MNT_SYNCHRONOUS); 3624 MNT_FLAG(MNT_NOEXEC); 3625 MNT_FLAG(MNT_NOSUID); 3626 MNT_FLAG(MNT_NFS4ACLS); 3627 MNT_FLAG(MNT_UNION); 3628 MNT_FLAG(MNT_ASYNC); 3629 MNT_FLAG(MNT_SUIDDIR); 3630 MNT_FLAG(MNT_SOFTDEP); 3631 MNT_FLAG(MNT_NOSYMFOLLOW); 3632 MNT_FLAG(MNT_GJOURNAL); 3633 MNT_FLAG(MNT_MULTILABEL); 3634 MNT_FLAG(MNT_ACLS); 3635 MNT_FLAG(MNT_NOATIME); 3636 MNT_FLAG(MNT_NOCLUSTERR); 3637 MNT_FLAG(MNT_NOCLUSTERW); 3638 MNT_FLAG(MNT_SUJ); 3639 MNT_FLAG(MNT_EXRDONLY); 3640 MNT_FLAG(MNT_EXPORTED); 3641 MNT_FLAG(MNT_DEFEXPORTED); 3642 MNT_FLAG(MNT_EXPORTANON); 3643 MNT_FLAG(MNT_EXKERB); 3644 MNT_FLAG(MNT_EXPUBLIC); 3645 MNT_FLAG(MNT_LOCAL); 3646 MNT_FLAG(MNT_QUOTA); 3647 MNT_FLAG(MNT_ROOTFS); 3648 MNT_FLAG(MNT_USER); 3649 MNT_FLAG(MNT_IGNORE); 3650 MNT_FLAG(MNT_UPDATE); 3651 MNT_FLAG(MNT_DELEXPORT); 3652 MNT_FLAG(MNT_RELOAD); 3653 MNT_FLAG(MNT_FORCE); 3654 MNT_FLAG(MNT_SNAPSHOT); 3655 MNT_FLAG(MNT_BYFSID); 3656 #undef MNT_FLAG 3657 if (mflags != 0) { 3658 if (buf[0] != '\0') 3659 strlcat(buf, ", ", sizeof(buf)); 3660 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3661 "0x%016jx", mflags); 3662 } 3663 db_printf(" mnt_flag = %s\n", buf); 3664 3665 buf[0] = '\0'; 3666 flags = mp->mnt_kern_flag; 3667 #define MNT_KERN_FLAG(flag) do { \ 3668 if (flags & (flag)) { \ 3669 if (buf[0] != '\0') \ 3670 strlcat(buf, ", ", sizeof(buf)); \ 3671 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3672 flags &= ~(flag); \ 3673 } \ 3674 } while (0) 3675 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3676 MNT_KERN_FLAG(MNTK_ASYNC); 3677 MNT_KERN_FLAG(MNTK_SOFTDEP); 3678 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 3679 MNT_KERN_FLAG(MNTK_DRAINING); 3680 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3681 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3682 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3683 MNT_KERN_FLAG(MNTK_NO_IOPF); 3684 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3685 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3686 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3687 MNT_KERN_FLAG(MNTK_MARKER); 3688 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3689 MNT_KERN_FLAG(MNTK_NOASYNC); 3690 MNT_KERN_FLAG(MNTK_UNMOUNT); 3691 MNT_KERN_FLAG(MNTK_MWAIT); 3692 MNT_KERN_FLAG(MNTK_SUSPEND); 3693 MNT_KERN_FLAG(MNTK_SUSPEND2); 3694 MNT_KERN_FLAG(MNTK_SUSPENDED); 3695 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3696 MNT_KERN_FLAG(MNTK_NOKNOTE); 3697 #undef MNT_KERN_FLAG 3698 if (flags != 0) { 3699 if (buf[0] != '\0') 3700 strlcat(buf, ", ", sizeof(buf)); 3701 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3702 "0x%08x", flags); 3703 } 3704 db_printf(" mnt_kern_flag = %s\n", buf); 3705 3706 db_printf(" mnt_opt = "); 3707 opt = TAILQ_FIRST(mp->mnt_opt); 3708 if (opt != NULL) { 3709 db_printf("%s", opt->name); 3710 opt = TAILQ_NEXT(opt, link); 3711 while (opt != NULL) { 3712 db_printf(", %s", opt->name); 3713 opt = TAILQ_NEXT(opt, link); 3714 } 3715 } 3716 db_printf("\n"); 3717 3718 sp = &mp->mnt_stat; 3719 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3720 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3721 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3722 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3723 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3724 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 3725 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 3726 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 3727 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 3728 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 3729 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 3730 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 3731 3732 db_printf(" mnt_cred = { uid=%u ruid=%u", 3733 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 3734 if (jailed(mp->mnt_cred)) 3735 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 3736 db_printf(" }\n"); 3737 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 3738 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 3739 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 3740 db_printf(" mnt_activevnodelistsize = %d\n", 3741 mp->mnt_activevnodelistsize); 3742 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 3743 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 3744 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 3745 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 3746 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); 3747 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 3748 db_printf(" mnt_secondary_accwrites = %d\n", 3749 mp->mnt_secondary_accwrites); 3750 db_printf(" mnt_gjprovider = %s\n", 3751 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 3752 3753 db_printf("\n\nList of active vnodes\n"); 3754 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 3755 if (vp->v_type != VMARKER) { 3756 vn_printf(vp, "vnode "); 3757 if (db_pager_quit) 3758 break; 3759 } 3760 } 3761 db_printf("\n\nList of inactive vnodes\n"); 3762 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3763 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 3764 vn_printf(vp, "vnode "); 3765 if (db_pager_quit) 3766 break; 3767 } 3768 } 3769 } 3770 #endif /* DDB */ 3771 3772 /* 3773 * Fill in a struct xvfsconf based on a struct vfsconf. 3774 */ 3775 static int 3776 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 3777 { 3778 struct xvfsconf xvfsp; 3779 3780 bzero(&xvfsp, sizeof(xvfsp)); 3781 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3782 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3783 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3784 xvfsp.vfc_flags = vfsp->vfc_flags; 3785 /* 3786 * These are unused in userland, we keep them 3787 * to not break binary compatibility. 3788 */ 3789 xvfsp.vfc_vfsops = NULL; 3790 xvfsp.vfc_next = NULL; 3791 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3792 } 3793 3794 #ifdef COMPAT_FREEBSD32 3795 struct xvfsconf32 { 3796 uint32_t vfc_vfsops; 3797 char vfc_name[MFSNAMELEN]; 3798 int32_t vfc_typenum; 3799 int32_t vfc_refcount; 3800 int32_t vfc_flags; 3801 uint32_t vfc_next; 3802 }; 3803 3804 static int 3805 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 3806 { 3807 struct xvfsconf32 xvfsp; 3808 3809 bzero(&xvfsp, sizeof(xvfsp)); 3810 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3811 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3812 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3813 xvfsp.vfc_flags = vfsp->vfc_flags; 3814 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3815 } 3816 #endif 3817 3818 /* 3819 * Top level filesystem related information gathering. 3820 */ 3821 static int 3822 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3823 { 3824 struct vfsconf *vfsp; 3825 int error; 3826 3827 error = 0; 3828 vfsconf_slock(); 3829 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3830 #ifdef COMPAT_FREEBSD32 3831 if (req->flags & SCTL_MASK32) 3832 error = vfsconf2x32(req, vfsp); 3833 else 3834 #endif 3835 error = vfsconf2x(req, vfsp); 3836 if (error) 3837 break; 3838 } 3839 vfsconf_sunlock(); 3840 return (error); 3841 } 3842 3843 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 3844 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 3845 "S,xvfsconf", "List of all configured filesystems"); 3846 3847 #ifndef BURN_BRIDGES 3848 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3849 3850 static int 3851 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3852 { 3853 int *name = (int *)arg1 - 1; /* XXX */ 3854 u_int namelen = arg2 + 1; /* XXX */ 3855 struct vfsconf *vfsp; 3856 3857 log(LOG_WARNING, "userland calling deprecated sysctl, " 3858 "please rebuild world\n"); 3859 3860 #if 1 || defined(COMPAT_PRELITE2) 3861 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3862 if (namelen == 1) 3863 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3864 #endif 3865 3866 switch (name[1]) { 3867 case VFS_MAXTYPENUM: 3868 if (namelen != 2) 3869 return (ENOTDIR); 3870 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3871 case VFS_CONF: 3872 if (namelen != 3) 3873 return (ENOTDIR); /* overloaded */ 3874 vfsconf_slock(); 3875 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3876 if (vfsp->vfc_typenum == name[2]) 3877 break; 3878 } 3879 vfsconf_sunlock(); 3880 if (vfsp == NULL) 3881 return (EOPNOTSUPP); 3882 #ifdef COMPAT_FREEBSD32 3883 if (req->flags & SCTL_MASK32) 3884 return (vfsconf2x32(req, vfsp)); 3885 else 3886 #endif 3887 return (vfsconf2x(req, vfsp)); 3888 } 3889 return (EOPNOTSUPP); 3890 } 3891 3892 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 3893 CTLFLAG_MPSAFE, vfs_sysctl, 3894 "Generic filesystem"); 3895 3896 #if 1 || defined(COMPAT_PRELITE2) 3897 3898 static int 3899 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3900 { 3901 int error; 3902 struct vfsconf *vfsp; 3903 struct ovfsconf ovfs; 3904 3905 vfsconf_slock(); 3906 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3907 bzero(&ovfs, sizeof(ovfs)); 3908 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3909 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3910 ovfs.vfc_index = vfsp->vfc_typenum; 3911 ovfs.vfc_refcount = vfsp->vfc_refcount; 3912 ovfs.vfc_flags = vfsp->vfc_flags; 3913 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3914 if (error != 0) { 3915 vfsconf_sunlock(); 3916 return (error); 3917 } 3918 } 3919 vfsconf_sunlock(); 3920 return (0); 3921 } 3922 3923 #endif /* 1 || COMPAT_PRELITE2 */ 3924 #endif /* !BURN_BRIDGES */ 3925 3926 #define KINFO_VNODESLOP 10 3927 #ifdef notyet 3928 /* 3929 * Dump vnode list (via sysctl). 3930 */ 3931 /* ARGSUSED */ 3932 static int 3933 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3934 { 3935 struct xvnode *xvn; 3936 struct mount *mp; 3937 struct vnode *vp; 3938 int error, len, n; 3939 3940 /* 3941 * Stale numvnodes access is not fatal here. 3942 */ 3943 req->lock = 0; 3944 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3945 if (!req->oldptr) 3946 /* Make an estimate */ 3947 return (SYSCTL_OUT(req, 0, len)); 3948 3949 error = sysctl_wire_old_buffer(req, 0); 3950 if (error != 0) 3951 return (error); 3952 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3953 n = 0; 3954 mtx_lock(&mountlist_mtx); 3955 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3956 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 3957 continue; 3958 MNT_ILOCK(mp); 3959 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3960 if (n == len) 3961 break; 3962 vref(vp); 3963 xvn[n].xv_size = sizeof *xvn; 3964 xvn[n].xv_vnode = vp; 3965 xvn[n].xv_id = 0; /* XXX compat */ 3966 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3967 XV_COPY(usecount); 3968 XV_COPY(writecount); 3969 XV_COPY(holdcnt); 3970 XV_COPY(mount); 3971 XV_COPY(numoutput); 3972 XV_COPY(type); 3973 #undef XV_COPY 3974 xvn[n].xv_flag = vp->v_vflag; 3975 3976 switch (vp->v_type) { 3977 case VREG: 3978 case VDIR: 3979 case VLNK: 3980 break; 3981 case VBLK: 3982 case VCHR: 3983 if (vp->v_rdev == NULL) { 3984 vrele(vp); 3985 continue; 3986 } 3987 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3988 break; 3989 case VSOCK: 3990 xvn[n].xv_socket = vp->v_socket; 3991 break; 3992 case VFIFO: 3993 xvn[n].xv_fifo = vp->v_fifoinfo; 3994 break; 3995 case VNON: 3996 case VBAD: 3997 default: 3998 /* shouldn't happen? */ 3999 vrele(vp); 4000 continue; 4001 } 4002 vrele(vp); 4003 ++n; 4004 } 4005 MNT_IUNLOCK(mp); 4006 mtx_lock(&mountlist_mtx); 4007 vfs_unbusy(mp); 4008 if (n == len) 4009 break; 4010 } 4011 mtx_unlock(&mountlist_mtx); 4012 4013 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 4014 free(xvn, M_TEMP); 4015 return (error); 4016 } 4017 4018 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 4019 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 4020 ""); 4021 #endif 4022 4023 static void 4024 unmount_or_warn(struct mount *mp) 4025 { 4026 int error; 4027 4028 error = dounmount(mp, MNT_FORCE, curthread); 4029 if (error != 0) { 4030 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4031 if (error == EBUSY) 4032 printf("BUSY)\n"); 4033 else 4034 printf("%d)\n", error); 4035 } 4036 } 4037 4038 /* 4039 * Unmount all filesystems. The list is traversed in reverse order 4040 * of mounting to avoid dependencies. 4041 */ 4042 void 4043 vfs_unmountall(void) 4044 { 4045 struct mount *mp, *tmp; 4046 4047 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4048 4049 /* 4050 * Since this only runs when rebooting, it is not interlocked. 4051 */ 4052 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4053 vfs_ref(mp); 4054 4055 /* 4056 * Forcibly unmounting "/dev" before "/" would prevent clean 4057 * unmount of the latter. 4058 */ 4059 if (mp == rootdevmp) 4060 continue; 4061 4062 unmount_or_warn(mp); 4063 } 4064 4065 if (rootdevmp != NULL) 4066 unmount_or_warn(rootdevmp); 4067 } 4068 4069 /* 4070 * perform msync on all vnodes under a mount point 4071 * the mount point must be locked. 4072 */ 4073 void 4074 vfs_msync(struct mount *mp, int flags) 4075 { 4076 struct vnode *vp, *mvp; 4077 struct vm_object *obj; 4078 4079 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4080 4081 vnlru_return_batch(mp); 4082 4083 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 4084 obj = vp->v_object; 4085 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 4086 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 4087 if (!vget(vp, 4088 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 4089 curthread)) { 4090 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 4091 vput(vp); 4092 continue; 4093 } 4094 4095 obj = vp->v_object; 4096 if (obj != NULL) { 4097 VM_OBJECT_WLOCK(obj); 4098 vm_object_page_clean(obj, 0, 0, 4099 flags == MNT_WAIT ? 4100 OBJPC_SYNC : OBJPC_NOSYNC); 4101 VM_OBJECT_WUNLOCK(obj); 4102 } 4103 vput(vp); 4104 } 4105 } else 4106 VI_UNLOCK(vp); 4107 } 4108 } 4109 4110 static void 4111 destroy_vpollinfo_free(struct vpollinfo *vi) 4112 { 4113 4114 knlist_destroy(&vi->vpi_selinfo.si_note); 4115 mtx_destroy(&vi->vpi_lock); 4116 uma_zfree(vnodepoll_zone, vi); 4117 } 4118 4119 static void 4120 destroy_vpollinfo(struct vpollinfo *vi) 4121 { 4122 4123 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4124 seldrain(&vi->vpi_selinfo); 4125 destroy_vpollinfo_free(vi); 4126 } 4127 4128 /* 4129 * Initialize per-vnode helper structure to hold poll-related state. 4130 */ 4131 void 4132 v_addpollinfo(struct vnode *vp) 4133 { 4134 struct vpollinfo *vi; 4135 4136 if (vp->v_pollinfo != NULL) 4137 return; 4138 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4139 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4140 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4141 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4142 VI_LOCK(vp); 4143 if (vp->v_pollinfo != NULL) { 4144 VI_UNLOCK(vp); 4145 destroy_vpollinfo_free(vi); 4146 return; 4147 } 4148 vp->v_pollinfo = vi; 4149 VI_UNLOCK(vp); 4150 } 4151 4152 /* 4153 * Record a process's interest in events which might happen to 4154 * a vnode. Because poll uses the historic select-style interface 4155 * internally, this routine serves as both the ``check for any 4156 * pending events'' and the ``record my interest in future events'' 4157 * functions. (These are done together, while the lock is held, 4158 * to avoid race conditions.) 4159 */ 4160 int 4161 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4162 { 4163 4164 v_addpollinfo(vp); 4165 mtx_lock(&vp->v_pollinfo->vpi_lock); 4166 if (vp->v_pollinfo->vpi_revents & events) { 4167 /* 4168 * This leaves events we are not interested 4169 * in available for the other process which 4170 * which presumably had requested them 4171 * (otherwise they would never have been 4172 * recorded). 4173 */ 4174 events &= vp->v_pollinfo->vpi_revents; 4175 vp->v_pollinfo->vpi_revents &= ~events; 4176 4177 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4178 return (events); 4179 } 4180 vp->v_pollinfo->vpi_events |= events; 4181 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4182 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4183 return (0); 4184 } 4185 4186 /* 4187 * Routine to create and manage a filesystem syncer vnode. 4188 */ 4189 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4190 static int sync_fsync(struct vop_fsync_args *); 4191 static int sync_inactive(struct vop_inactive_args *); 4192 static int sync_reclaim(struct vop_reclaim_args *); 4193 4194 static struct vop_vector sync_vnodeops = { 4195 .vop_bypass = VOP_EOPNOTSUPP, 4196 .vop_close = sync_close, /* close */ 4197 .vop_fsync = sync_fsync, /* fsync */ 4198 .vop_inactive = sync_inactive, /* inactive */ 4199 .vop_reclaim = sync_reclaim, /* reclaim */ 4200 .vop_lock1 = vop_stdlock, /* lock */ 4201 .vop_unlock = vop_stdunlock, /* unlock */ 4202 .vop_islocked = vop_stdislocked, /* islocked */ 4203 }; 4204 4205 /* 4206 * Create a new filesystem syncer vnode for the specified mount point. 4207 */ 4208 void 4209 vfs_allocate_syncvnode(struct mount *mp) 4210 { 4211 struct vnode *vp; 4212 struct bufobj *bo; 4213 static long start, incr, next; 4214 int error; 4215 4216 /* Allocate a new vnode */ 4217 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4218 if (error != 0) 4219 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4220 vp->v_type = VNON; 4221 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4222 vp->v_vflag |= VV_FORCEINSMQ; 4223 error = insmntque(vp, mp); 4224 if (error != 0) 4225 panic("vfs_allocate_syncvnode: insmntque() failed"); 4226 vp->v_vflag &= ~VV_FORCEINSMQ; 4227 VOP_UNLOCK(vp, 0); 4228 /* 4229 * Place the vnode onto the syncer worklist. We attempt to 4230 * scatter them about on the list so that they will go off 4231 * at evenly distributed times even if all the filesystems 4232 * are mounted at once. 4233 */ 4234 next += incr; 4235 if (next == 0 || next > syncer_maxdelay) { 4236 start /= 2; 4237 incr /= 2; 4238 if (start == 0) { 4239 start = syncer_maxdelay / 2; 4240 incr = syncer_maxdelay; 4241 } 4242 next = start; 4243 } 4244 bo = &vp->v_bufobj; 4245 BO_LOCK(bo); 4246 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4247 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4248 mtx_lock(&sync_mtx); 4249 sync_vnode_count++; 4250 if (mp->mnt_syncer == NULL) { 4251 mp->mnt_syncer = vp; 4252 vp = NULL; 4253 } 4254 mtx_unlock(&sync_mtx); 4255 BO_UNLOCK(bo); 4256 if (vp != NULL) { 4257 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4258 vgone(vp); 4259 vput(vp); 4260 } 4261 } 4262 4263 void 4264 vfs_deallocate_syncvnode(struct mount *mp) 4265 { 4266 struct vnode *vp; 4267 4268 mtx_lock(&sync_mtx); 4269 vp = mp->mnt_syncer; 4270 if (vp != NULL) 4271 mp->mnt_syncer = NULL; 4272 mtx_unlock(&sync_mtx); 4273 if (vp != NULL) 4274 vrele(vp); 4275 } 4276 4277 /* 4278 * Do a lazy sync of the filesystem. 4279 */ 4280 static int 4281 sync_fsync(struct vop_fsync_args *ap) 4282 { 4283 struct vnode *syncvp = ap->a_vp; 4284 struct mount *mp = syncvp->v_mount; 4285 int error, save; 4286 struct bufobj *bo; 4287 4288 /* 4289 * We only need to do something if this is a lazy evaluation. 4290 */ 4291 if (ap->a_waitfor != MNT_LAZY) 4292 return (0); 4293 4294 /* 4295 * Move ourselves to the back of the sync list. 4296 */ 4297 bo = &syncvp->v_bufobj; 4298 BO_LOCK(bo); 4299 vn_syncer_add_to_worklist(bo, syncdelay); 4300 BO_UNLOCK(bo); 4301 4302 /* 4303 * Walk the list of vnodes pushing all that are dirty and 4304 * not already on the sync list. 4305 */ 4306 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4307 return (0); 4308 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4309 vfs_unbusy(mp); 4310 return (0); 4311 } 4312 save = curthread_pflags_set(TDP_SYNCIO); 4313 vfs_msync(mp, MNT_NOWAIT); 4314 error = VFS_SYNC(mp, MNT_LAZY); 4315 curthread_pflags_restore(save); 4316 vn_finished_write(mp); 4317 vfs_unbusy(mp); 4318 return (error); 4319 } 4320 4321 /* 4322 * The syncer vnode is no referenced. 4323 */ 4324 static int 4325 sync_inactive(struct vop_inactive_args *ap) 4326 { 4327 4328 vgone(ap->a_vp); 4329 return (0); 4330 } 4331 4332 /* 4333 * The syncer vnode is no longer needed and is being decommissioned. 4334 * 4335 * Modifications to the worklist must be protected by sync_mtx. 4336 */ 4337 static int 4338 sync_reclaim(struct vop_reclaim_args *ap) 4339 { 4340 struct vnode *vp = ap->a_vp; 4341 struct bufobj *bo; 4342 4343 bo = &vp->v_bufobj; 4344 BO_LOCK(bo); 4345 mtx_lock(&sync_mtx); 4346 if (vp->v_mount->mnt_syncer == vp) 4347 vp->v_mount->mnt_syncer = NULL; 4348 if (bo->bo_flag & BO_ONWORKLST) { 4349 LIST_REMOVE(bo, bo_synclist); 4350 syncer_worklist_len--; 4351 sync_vnode_count--; 4352 bo->bo_flag &= ~BO_ONWORKLST; 4353 } 4354 mtx_unlock(&sync_mtx); 4355 BO_UNLOCK(bo); 4356 4357 return (0); 4358 } 4359 4360 /* 4361 * Check if vnode represents a disk device 4362 */ 4363 int 4364 vn_isdisk(struct vnode *vp, int *errp) 4365 { 4366 int error; 4367 4368 if (vp->v_type != VCHR) { 4369 error = ENOTBLK; 4370 goto out; 4371 } 4372 error = 0; 4373 dev_lock(); 4374 if (vp->v_rdev == NULL) 4375 error = ENXIO; 4376 else if (vp->v_rdev->si_devsw == NULL) 4377 error = ENXIO; 4378 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4379 error = ENOTBLK; 4380 dev_unlock(); 4381 out: 4382 if (errp != NULL) 4383 *errp = error; 4384 return (error == 0); 4385 } 4386 4387 /* 4388 * Common filesystem object access control check routine. Accepts a 4389 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4390 * and optional call-by-reference privused argument allowing vaccess() 4391 * to indicate to the caller whether privilege was used to satisfy the 4392 * request (obsoleted). Returns 0 on success, or an errno on failure. 4393 */ 4394 int 4395 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4396 accmode_t accmode, struct ucred *cred, int *privused) 4397 { 4398 accmode_t dac_granted; 4399 accmode_t priv_granted; 4400 4401 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4402 ("invalid bit in accmode")); 4403 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4404 ("VAPPEND without VWRITE")); 4405 4406 /* 4407 * Look for a normal, non-privileged way to access the file/directory 4408 * as requested. If it exists, go with that. 4409 */ 4410 4411 if (privused != NULL) 4412 *privused = 0; 4413 4414 dac_granted = 0; 4415 4416 /* Check the owner. */ 4417 if (cred->cr_uid == file_uid) { 4418 dac_granted |= VADMIN; 4419 if (file_mode & S_IXUSR) 4420 dac_granted |= VEXEC; 4421 if (file_mode & S_IRUSR) 4422 dac_granted |= VREAD; 4423 if (file_mode & S_IWUSR) 4424 dac_granted |= (VWRITE | VAPPEND); 4425 4426 if ((accmode & dac_granted) == accmode) 4427 return (0); 4428 4429 goto privcheck; 4430 } 4431 4432 /* Otherwise, check the groups (first match) */ 4433 if (groupmember(file_gid, cred)) { 4434 if (file_mode & S_IXGRP) 4435 dac_granted |= VEXEC; 4436 if (file_mode & S_IRGRP) 4437 dac_granted |= VREAD; 4438 if (file_mode & S_IWGRP) 4439 dac_granted |= (VWRITE | VAPPEND); 4440 4441 if ((accmode & dac_granted) == accmode) 4442 return (0); 4443 4444 goto privcheck; 4445 } 4446 4447 /* Otherwise, check everyone else. */ 4448 if (file_mode & S_IXOTH) 4449 dac_granted |= VEXEC; 4450 if (file_mode & S_IROTH) 4451 dac_granted |= VREAD; 4452 if (file_mode & S_IWOTH) 4453 dac_granted |= (VWRITE | VAPPEND); 4454 if ((accmode & dac_granted) == accmode) 4455 return (0); 4456 4457 privcheck: 4458 /* 4459 * Build a privilege mask to determine if the set of privileges 4460 * satisfies the requirements when combined with the granted mask 4461 * from above. For each privilege, if the privilege is required, 4462 * bitwise or the request type onto the priv_granted mask. 4463 */ 4464 priv_granted = 0; 4465 4466 if (type == VDIR) { 4467 /* 4468 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4469 * requests, instead of PRIV_VFS_EXEC. 4470 */ 4471 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4472 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 4473 priv_granted |= VEXEC; 4474 } else { 4475 /* 4476 * Ensure that at least one execute bit is on. Otherwise, 4477 * a privileged user will always succeed, and we don't want 4478 * this to happen unless the file really is executable. 4479 */ 4480 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4481 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4482 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 4483 priv_granted |= VEXEC; 4484 } 4485 4486 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4487 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 4488 priv_granted |= VREAD; 4489 4490 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4491 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 4492 priv_granted |= (VWRITE | VAPPEND); 4493 4494 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4495 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 4496 priv_granted |= VADMIN; 4497 4498 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4499 /* XXX audit: privilege used */ 4500 if (privused != NULL) 4501 *privused = 1; 4502 return (0); 4503 } 4504 4505 return ((accmode & VADMIN) ? EPERM : EACCES); 4506 } 4507 4508 /* 4509 * Credential check based on process requesting service, and per-attribute 4510 * permissions. 4511 */ 4512 int 4513 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4514 struct thread *td, accmode_t accmode) 4515 { 4516 4517 /* 4518 * Kernel-invoked always succeeds. 4519 */ 4520 if (cred == NOCRED) 4521 return (0); 4522 4523 /* 4524 * Do not allow privileged processes in jail to directly manipulate 4525 * system attributes. 4526 */ 4527 switch (attrnamespace) { 4528 case EXTATTR_NAMESPACE_SYSTEM: 4529 /* Potentially should be: return (EPERM); */ 4530 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 4531 case EXTATTR_NAMESPACE_USER: 4532 return (VOP_ACCESS(vp, accmode, cred, td)); 4533 default: 4534 return (EPERM); 4535 } 4536 } 4537 4538 #ifdef DEBUG_VFS_LOCKS 4539 /* 4540 * This only exists to suppress warnings from unlocked specfs accesses. It is 4541 * no longer ok to have an unlocked VFS. 4542 */ 4543 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4544 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4545 4546 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4547 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4548 "Drop into debugger on lock violation"); 4549 4550 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4551 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4552 0, "Check for interlock across VOPs"); 4553 4554 int vfs_badlock_print = 1; /* Print lock violations. */ 4555 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4556 0, "Print lock violations"); 4557 4558 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 4559 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 4560 0, "Print vnode details on lock violations"); 4561 4562 #ifdef KDB 4563 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4564 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4565 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4566 #endif 4567 4568 static void 4569 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4570 { 4571 4572 #ifdef KDB 4573 if (vfs_badlock_backtrace) 4574 kdb_backtrace(); 4575 #endif 4576 if (vfs_badlock_vnode) 4577 vn_printf(vp, "vnode "); 4578 if (vfs_badlock_print) 4579 printf("%s: %p %s\n", str, (void *)vp, msg); 4580 if (vfs_badlock_ddb) 4581 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4582 } 4583 4584 void 4585 assert_vi_locked(struct vnode *vp, const char *str) 4586 { 4587 4588 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4589 vfs_badlock("interlock is not locked but should be", str, vp); 4590 } 4591 4592 void 4593 assert_vi_unlocked(struct vnode *vp, const char *str) 4594 { 4595 4596 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4597 vfs_badlock("interlock is locked but should not be", str, vp); 4598 } 4599 4600 void 4601 assert_vop_locked(struct vnode *vp, const char *str) 4602 { 4603 int locked; 4604 4605 if (!IGNORE_LOCK(vp)) { 4606 locked = VOP_ISLOCKED(vp); 4607 if (locked == 0 || locked == LK_EXCLOTHER) 4608 vfs_badlock("is not locked but should be", str, vp); 4609 } 4610 } 4611 4612 void 4613 assert_vop_unlocked(struct vnode *vp, const char *str) 4614 { 4615 4616 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4617 vfs_badlock("is locked but should not be", str, vp); 4618 } 4619 4620 void 4621 assert_vop_elocked(struct vnode *vp, const char *str) 4622 { 4623 4624 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4625 vfs_badlock("is not exclusive locked but should be", str, vp); 4626 } 4627 #endif /* DEBUG_VFS_LOCKS */ 4628 4629 void 4630 vop_rename_fail(struct vop_rename_args *ap) 4631 { 4632 4633 if (ap->a_tvp != NULL) 4634 vput(ap->a_tvp); 4635 if (ap->a_tdvp == ap->a_tvp) 4636 vrele(ap->a_tdvp); 4637 else 4638 vput(ap->a_tdvp); 4639 vrele(ap->a_fdvp); 4640 vrele(ap->a_fvp); 4641 } 4642 4643 void 4644 vop_rename_pre(void *ap) 4645 { 4646 struct vop_rename_args *a = ap; 4647 4648 #ifdef DEBUG_VFS_LOCKS 4649 if (a->a_tvp) 4650 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4651 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4652 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4653 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4654 4655 /* Check the source (from). */ 4656 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4657 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4658 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4659 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4660 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4661 4662 /* Check the target. */ 4663 if (a->a_tvp) 4664 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4665 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4666 #endif 4667 if (a->a_tdvp != a->a_fdvp) 4668 vhold(a->a_fdvp); 4669 if (a->a_tvp != a->a_fvp) 4670 vhold(a->a_fvp); 4671 vhold(a->a_tdvp); 4672 if (a->a_tvp) 4673 vhold(a->a_tvp); 4674 } 4675 4676 #ifdef DEBUG_VFS_LOCKS 4677 void 4678 vop_strategy_pre(void *ap) 4679 { 4680 struct vop_strategy_args *a; 4681 struct buf *bp; 4682 4683 a = ap; 4684 bp = a->a_bp; 4685 4686 /* 4687 * Cluster ops lock their component buffers but not the IO container. 4688 */ 4689 if ((bp->b_flags & B_CLUSTER) != 0) 4690 return; 4691 4692 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4693 if (vfs_badlock_print) 4694 printf( 4695 "VOP_STRATEGY: bp is not locked but should be\n"); 4696 if (vfs_badlock_ddb) 4697 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4698 } 4699 } 4700 4701 void 4702 vop_lock_pre(void *ap) 4703 { 4704 struct vop_lock1_args *a = ap; 4705 4706 if ((a->a_flags & LK_INTERLOCK) == 0) 4707 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4708 else 4709 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 4710 } 4711 4712 void 4713 vop_lock_post(void *ap, int rc) 4714 { 4715 struct vop_lock1_args *a = ap; 4716 4717 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4718 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 4719 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 4720 } 4721 4722 void 4723 vop_unlock_pre(void *ap) 4724 { 4725 struct vop_unlock_args *a = ap; 4726 4727 if (a->a_flags & LK_INTERLOCK) 4728 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4729 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4730 } 4731 4732 void 4733 vop_unlock_post(void *ap, int rc) 4734 { 4735 struct vop_unlock_args *a = ap; 4736 4737 if (a->a_flags & LK_INTERLOCK) 4738 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4739 } 4740 #endif 4741 4742 void 4743 vop_create_post(void *ap, int rc) 4744 { 4745 struct vop_create_args *a = ap; 4746 4747 if (!rc) 4748 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4749 } 4750 4751 void 4752 vop_deleteextattr_post(void *ap, int rc) 4753 { 4754 struct vop_deleteextattr_args *a = ap; 4755 4756 if (!rc) 4757 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4758 } 4759 4760 void 4761 vop_link_post(void *ap, int rc) 4762 { 4763 struct vop_link_args *a = ap; 4764 4765 if (!rc) { 4766 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4767 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4768 } 4769 } 4770 4771 void 4772 vop_mkdir_post(void *ap, int rc) 4773 { 4774 struct vop_mkdir_args *a = ap; 4775 4776 if (!rc) 4777 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4778 } 4779 4780 void 4781 vop_mknod_post(void *ap, int rc) 4782 { 4783 struct vop_mknod_args *a = ap; 4784 4785 if (!rc) 4786 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4787 } 4788 4789 void 4790 vop_reclaim_post(void *ap, int rc) 4791 { 4792 struct vop_reclaim_args *a = ap; 4793 4794 if (!rc) 4795 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 4796 } 4797 4798 void 4799 vop_remove_post(void *ap, int rc) 4800 { 4801 struct vop_remove_args *a = ap; 4802 4803 if (!rc) { 4804 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4805 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4806 } 4807 } 4808 4809 void 4810 vop_rename_post(void *ap, int rc) 4811 { 4812 struct vop_rename_args *a = ap; 4813 long hint; 4814 4815 if (!rc) { 4816 hint = NOTE_WRITE; 4817 if (a->a_fdvp == a->a_tdvp) { 4818 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 4819 hint |= NOTE_LINK; 4820 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4821 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4822 } else { 4823 hint |= NOTE_EXTEND; 4824 if (a->a_fvp->v_type == VDIR) 4825 hint |= NOTE_LINK; 4826 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4827 4828 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 4829 a->a_tvp->v_type == VDIR) 4830 hint &= ~NOTE_LINK; 4831 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4832 } 4833 4834 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4835 if (a->a_tvp) 4836 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4837 } 4838 if (a->a_tdvp != a->a_fdvp) 4839 vdrop(a->a_fdvp); 4840 if (a->a_tvp != a->a_fvp) 4841 vdrop(a->a_fvp); 4842 vdrop(a->a_tdvp); 4843 if (a->a_tvp) 4844 vdrop(a->a_tvp); 4845 } 4846 4847 void 4848 vop_rmdir_post(void *ap, int rc) 4849 { 4850 struct vop_rmdir_args *a = ap; 4851 4852 if (!rc) { 4853 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4854 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4855 } 4856 } 4857 4858 void 4859 vop_setattr_post(void *ap, int rc) 4860 { 4861 struct vop_setattr_args *a = ap; 4862 4863 if (!rc) 4864 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4865 } 4866 4867 void 4868 vop_setextattr_post(void *ap, int rc) 4869 { 4870 struct vop_setextattr_args *a = ap; 4871 4872 if (!rc) 4873 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4874 } 4875 4876 void 4877 vop_symlink_post(void *ap, int rc) 4878 { 4879 struct vop_symlink_args *a = ap; 4880 4881 if (!rc) 4882 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4883 } 4884 4885 void 4886 vop_open_post(void *ap, int rc) 4887 { 4888 struct vop_open_args *a = ap; 4889 4890 if (!rc) 4891 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 4892 } 4893 4894 void 4895 vop_close_post(void *ap, int rc) 4896 { 4897 struct vop_close_args *a = ap; 4898 4899 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 4900 (a->a_vp->v_iflag & VI_DOOMED) == 0)) { 4901 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 4902 NOTE_CLOSE_WRITE : NOTE_CLOSE); 4903 } 4904 } 4905 4906 void 4907 vop_read_post(void *ap, int rc) 4908 { 4909 struct vop_read_args *a = ap; 4910 4911 if (!rc) 4912 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4913 } 4914 4915 void 4916 vop_readdir_post(void *ap, int rc) 4917 { 4918 struct vop_readdir_args *a = ap; 4919 4920 if (!rc) 4921 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4922 } 4923 4924 static struct knlist fs_knlist; 4925 4926 static void 4927 vfs_event_init(void *arg) 4928 { 4929 knlist_init_mtx(&fs_knlist, NULL); 4930 } 4931 /* XXX - correct order? */ 4932 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 4933 4934 void 4935 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 4936 { 4937 4938 KNOTE_UNLOCKED(&fs_knlist, event); 4939 } 4940 4941 static int filt_fsattach(struct knote *kn); 4942 static void filt_fsdetach(struct knote *kn); 4943 static int filt_fsevent(struct knote *kn, long hint); 4944 4945 struct filterops fs_filtops = { 4946 .f_isfd = 0, 4947 .f_attach = filt_fsattach, 4948 .f_detach = filt_fsdetach, 4949 .f_event = filt_fsevent 4950 }; 4951 4952 static int 4953 filt_fsattach(struct knote *kn) 4954 { 4955 4956 kn->kn_flags |= EV_CLEAR; 4957 knlist_add(&fs_knlist, kn, 0); 4958 return (0); 4959 } 4960 4961 static void 4962 filt_fsdetach(struct knote *kn) 4963 { 4964 4965 knlist_remove(&fs_knlist, kn, 0); 4966 } 4967 4968 static int 4969 filt_fsevent(struct knote *kn, long hint) 4970 { 4971 4972 kn->kn_fflags |= hint; 4973 return (kn->kn_fflags != 0); 4974 } 4975 4976 static int 4977 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 4978 { 4979 struct vfsidctl vc; 4980 int error; 4981 struct mount *mp; 4982 4983 error = SYSCTL_IN(req, &vc, sizeof(vc)); 4984 if (error) 4985 return (error); 4986 if (vc.vc_vers != VFS_CTL_VERS1) 4987 return (EINVAL); 4988 mp = vfs_getvfs(&vc.vc_fsid); 4989 if (mp == NULL) 4990 return (ENOENT); 4991 /* ensure that a specific sysctl goes to the right filesystem. */ 4992 if (strcmp(vc.vc_fstypename, "*") != 0 && 4993 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 4994 vfs_rel(mp); 4995 return (EINVAL); 4996 } 4997 VCTLTOREQ(&vc, req); 4998 error = VFS_SYSCTL(mp, vc.vc_op, req); 4999 vfs_rel(mp); 5000 return (error); 5001 } 5002 5003 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 5004 NULL, 0, sysctl_vfs_ctl, "", 5005 "Sysctl by fsid"); 5006 5007 /* 5008 * Function to initialize a va_filerev field sensibly. 5009 * XXX: Wouldn't a random number make a lot more sense ?? 5010 */ 5011 u_quad_t 5012 init_va_filerev(void) 5013 { 5014 struct bintime bt; 5015 5016 getbinuptime(&bt); 5017 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 5018 } 5019 5020 static int filt_vfsread(struct knote *kn, long hint); 5021 static int filt_vfswrite(struct knote *kn, long hint); 5022 static int filt_vfsvnode(struct knote *kn, long hint); 5023 static void filt_vfsdetach(struct knote *kn); 5024 static struct filterops vfsread_filtops = { 5025 .f_isfd = 1, 5026 .f_detach = filt_vfsdetach, 5027 .f_event = filt_vfsread 5028 }; 5029 static struct filterops vfswrite_filtops = { 5030 .f_isfd = 1, 5031 .f_detach = filt_vfsdetach, 5032 .f_event = filt_vfswrite 5033 }; 5034 static struct filterops vfsvnode_filtops = { 5035 .f_isfd = 1, 5036 .f_detach = filt_vfsdetach, 5037 .f_event = filt_vfsvnode 5038 }; 5039 5040 static void 5041 vfs_knllock(void *arg) 5042 { 5043 struct vnode *vp = arg; 5044 5045 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5046 } 5047 5048 static void 5049 vfs_knlunlock(void *arg) 5050 { 5051 struct vnode *vp = arg; 5052 5053 VOP_UNLOCK(vp, 0); 5054 } 5055 5056 static void 5057 vfs_knl_assert_locked(void *arg) 5058 { 5059 #ifdef DEBUG_VFS_LOCKS 5060 struct vnode *vp = arg; 5061 5062 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5063 #endif 5064 } 5065 5066 static void 5067 vfs_knl_assert_unlocked(void *arg) 5068 { 5069 #ifdef DEBUG_VFS_LOCKS 5070 struct vnode *vp = arg; 5071 5072 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5073 #endif 5074 } 5075 5076 int 5077 vfs_kqfilter(struct vop_kqfilter_args *ap) 5078 { 5079 struct vnode *vp = ap->a_vp; 5080 struct knote *kn = ap->a_kn; 5081 struct knlist *knl; 5082 5083 switch (kn->kn_filter) { 5084 case EVFILT_READ: 5085 kn->kn_fop = &vfsread_filtops; 5086 break; 5087 case EVFILT_WRITE: 5088 kn->kn_fop = &vfswrite_filtops; 5089 break; 5090 case EVFILT_VNODE: 5091 kn->kn_fop = &vfsvnode_filtops; 5092 break; 5093 default: 5094 return (EINVAL); 5095 } 5096 5097 kn->kn_hook = (caddr_t)vp; 5098 5099 v_addpollinfo(vp); 5100 if (vp->v_pollinfo == NULL) 5101 return (ENOMEM); 5102 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5103 vhold(vp); 5104 knlist_add(knl, kn, 0); 5105 5106 return (0); 5107 } 5108 5109 /* 5110 * Detach knote from vnode 5111 */ 5112 static void 5113 filt_vfsdetach(struct knote *kn) 5114 { 5115 struct vnode *vp = (struct vnode *)kn->kn_hook; 5116 5117 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5118 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5119 vdrop(vp); 5120 } 5121 5122 /*ARGSUSED*/ 5123 static int 5124 filt_vfsread(struct knote *kn, long hint) 5125 { 5126 struct vnode *vp = (struct vnode *)kn->kn_hook; 5127 struct vattr va; 5128 int res; 5129 5130 /* 5131 * filesystem is gone, so set the EOF flag and schedule 5132 * the knote for deletion. 5133 */ 5134 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5135 VI_LOCK(vp); 5136 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5137 VI_UNLOCK(vp); 5138 return (1); 5139 } 5140 5141 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5142 return (0); 5143 5144 VI_LOCK(vp); 5145 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5146 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5147 VI_UNLOCK(vp); 5148 return (res); 5149 } 5150 5151 /*ARGSUSED*/ 5152 static int 5153 filt_vfswrite(struct knote *kn, long hint) 5154 { 5155 struct vnode *vp = (struct vnode *)kn->kn_hook; 5156 5157 VI_LOCK(vp); 5158 5159 /* 5160 * filesystem is gone, so set the EOF flag and schedule 5161 * the knote for deletion. 5162 */ 5163 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5164 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5165 5166 kn->kn_data = 0; 5167 VI_UNLOCK(vp); 5168 return (1); 5169 } 5170 5171 static int 5172 filt_vfsvnode(struct knote *kn, long hint) 5173 { 5174 struct vnode *vp = (struct vnode *)kn->kn_hook; 5175 int res; 5176 5177 VI_LOCK(vp); 5178 if (kn->kn_sfflags & hint) 5179 kn->kn_fflags |= hint; 5180 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5181 kn->kn_flags |= EV_EOF; 5182 VI_UNLOCK(vp); 5183 return (1); 5184 } 5185 res = (kn->kn_fflags != 0); 5186 VI_UNLOCK(vp); 5187 return (res); 5188 } 5189 5190 int 5191 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5192 { 5193 int error; 5194 5195 if (dp->d_reclen > ap->a_uio->uio_resid) 5196 return (ENAMETOOLONG); 5197 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5198 if (error) { 5199 if (ap->a_ncookies != NULL) { 5200 if (ap->a_cookies != NULL) 5201 free(ap->a_cookies, M_TEMP); 5202 ap->a_cookies = NULL; 5203 *ap->a_ncookies = 0; 5204 } 5205 return (error); 5206 } 5207 if (ap->a_ncookies == NULL) 5208 return (0); 5209 5210 KASSERT(ap->a_cookies, 5211 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5212 5213 *ap->a_cookies = realloc(*ap->a_cookies, 5214 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5215 (*ap->a_cookies)[*ap->a_ncookies] = off; 5216 *ap->a_ncookies += 1; 5217 return (0); 5218 } 5219 5220 /* 5221 * Mark for update the access time of the file if the filesystem 5222 * supports VOP_MARKATIME. This functionality is used by execve and 5223 * mmap, so we want to avoid the I/O implied by directly setting 5224 * va_atime for the sake of efficiency. 5225 */ 5226 void 5227 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5228 { 5229 struct mount *mp; 5230 5231 mp = vp->v_mount; 5232 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5233 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5234 (void)VOP_MARKATIME(vp); 5235 } 5236 5237 /* 5238 * The purpose of this routine is to remove granularity from accmode_t, 5239 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5240 * VADMIN and VAPPEND. 5241 * 5242 * If it returns 0, the caller is supposed to continue with the usual 5243 * access checks using 'accmode' as modified by this routine. If it 5244 * returns nonzero value, the caller is supposed to return that value 5245 * as errno. 5246 * 5247 * Note that after this routine runs, accmode may be zero. 5248 */ 5249 int 5250 vfs_unixify_accmode(accmode_t *accmode) 5251 { 5252 /* 5253 * There is no way to specify explicit "deny" rule using 5254 * file mode or POSIX.1e ACLs. 5255 */ 5256 if (*accmode & VEXPLICIT_DENY) { 5257 *accmode = 0; 5258 return (0); 5259 } 5260 5261 /* 5262 * None of these can be translated into usual access bits. 5263 * Also, the common case for NFSv4 ACLs is to not contain 5264 * either of these bits. Caller should check for VWRITE 5265 * on the containing directory instead. 5266 */ 5267 if (*accmode & (VDELETE_CHILD | VDELETE)) 5268 return (EPERM); 5269 5270 if (*accmode & VADMIN_PERMS) { 5271 *accmode &= ~VADMIN_PERMS; 5272 *accmode |= VADMIN; 5273 } 5274 5275 /* 5276 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 5277 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 5278 */ 5279 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 5280 5281 return (0); 5282 } 5283 5284 /* 5285 * These are helper functions for filesystems to traverse all 5286 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 5287 * 5288 * This interface replaces MNT_VNODE_FOREACH. 5289 */ 5290 5291 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 5292 5293 struct vnode * 5294 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5295 { 5296 struct vnode *vp; 5297 5298 if (should_yield()) 5299 kern_yield(PRI_USER); 5300 MNT_ILOCK(mp); 5301 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5302 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; 5303 vp = TAILQ_NEXT(vp, v_nmntvnodes)) { 5304 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5305 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5306 continue; 5307 VI_LOCK(vp); 5308 if ((vp->v_iflag & VI_DOOMED) != 0) { 5309 VI_UNLOCK(vp); 5310 continue; 5311 } 5312 break; 5313 } 5314 if (vp == NULL) { 5315 __mnt_vnode_markerfree_all(mvp, mp); 5316 /* MNT_IUNLOCK(mp); -- done in above function */ 5317 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5318 return (NULL); 5319 } 5320 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5321 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5322 MNT_IUNLOCK(mp); 5323 return (vp); 5324 } 5325 5326 struct vnode * 5327 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5328 { 5329 struct vnode *vp; 5330 5331 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5332 MNT_ILOCK(mp); 5333 MNT_REF(mp); 5334 (*mvp)->v_mount = mp; 5335 (*mvp)->v_type = VMARKER; 5336 5337 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 5338 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ 5339 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) 5340 continue; 5341 VI_LOCK(vp); 5342 if ((vp->v_iflag & VI_DOOMED) != 0) { 5343 VI_UNLOCK(vp); 5344 continue; 5345 } 5346 break; 5347 } 5348 if (vp == NULL) { 5349 MNT_REL(mp); 5350 MNT_IUNLOCK(mp); 5351 free(*mvp, M_VNODE_MARKER); 5352 *mvp = NULL; 5353 return (NULL); 5354 } 5355 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5356 MNT_IUNLOCK(mp); 5357 return (vp); 5358 } 5359 5360 void 5361 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5362 { 5363 5364 if (*mvp == NULL) { 5365 MNT_IUNLOCK(mp); 5366 return; 5367 } 5368 5369 mtx_assert(MNT_MTX(mp), MA_OWNED); 5370 5371 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5372 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5373 MNT_REL(mp); 5374 MNT_IUNLOCK(mp); 5375 free(*mvp, M_VNODE_MARKER); 5376 *mvp = NULL; 5377 } 5378 5379 /* 5380 * These are helper functions for filesystems to traverse their 5381 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5382 */ 5383 static void 5384 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5385 { 5386 5387 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5388 5389 MNT_ILOCK(mp); 5390 MNT_REL(mp); 5391 MNT_IUNLOCK(mp); 5392 free(*mvp, M_VNODE_MARKER); 5393 *mvp = NULL; 5394 } 5395 5396 /* 5397 * Relock the mp mount vnode list lock with the vp vnode interlock in the 5398 * conventional lock order during mnt_vnode_next_active iteration. 5399 * 5400 * On entry, the mount vnode list lock is held and the vnode interlock is not. 5401 * The list lock is dropped and reacquired. On success, both locks are held. 5402 * On failure, the mount vnode list lock is held but the vnode interlock is 5403 * not, and the procedure may have yielded. 5404 */ 5405 static bool 5406 mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp, 5407 struct vnode *vp) 5408 { 5409 const struct vnode *tmp; 5410 bool held, ret; 5411 5412 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && 5413 TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp, 5414 ("%s: bad marker", __func__)); 5415 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, 5416 ("%s: inappropriate vnode", __func__)); 5417 ASSERT_VI_UNLOCKED(vp, __func__); 5418 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5419 5420 ret = false; 5421 5422 TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist); 5423 TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist); 5424 5425 /* 5426 * Use a hold to prevent vp from disappearing while the mount vnode 5427 * list lock is dropped and reacquired. Normally a hold would be 5428 * acquired with vhold(), but that might try to acquire the vnode 5429 * interlock, which would be a LOR with the mount vnode list lock. 5430 */ 5431 held = vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt); 5432 mtx_unlock(&mp->mnt_listmtx); 5433 if (!held) 5434 goto abort; 5435 VI_LOCK(vp); 5436 if (!vfs_refcount_release_if_not_last(&vp->v_holdcnt)) { 5437 vdropl(vp); 5438 goto abort; 5439 } 5440 mtx_lock(&mp->mnt_listmtx); 5441 5442 /* 5443 * Determine whether the vnode is still the next one after the marker, 5444 * excepting any other markers. If the vnode has not been doomed by 5445 * vgone() then the hold should have ensured that it remained on the 5446 * active list. If it has been doomed but is still on the active list, 5447 * don't abort, but rather skip over it (avoid spinning on doomed 5448 * vnodes). 5449 */ 5450 tmp = mvp; 5451 do { 5452 tmp = TAILQ_NEXT(tmp, v_actfreelist); 5453 } while (tmp != NULL && tmp->v_type == VMARKER); 5454 if (tmp != vp) { 5455 mtx_unlock(&mp->mnt_listmtx); 5456 VI_UNLOCK(vp); 5457 goto abort; 5458 } 5459 5460 ret = true; 5461 goto out; 5462 abort: 5463 maybe_yield(); 5464 mtx_lock(&mp->mnt_listmtx); 5465 out: 5466 if (ret) 5467 ASSERT_VI_LOCKED(vp, __func__); 5468 else 5469 ASSERT_VI_UNLOCKED(vp, __func__); 5470 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5471 return (ret); 5472 } 5473 5474 static struct vnode * 5475 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5476 { 5477 struct vnode *vp, *nvp; 5478 5479 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5480 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5481 restart: 5482 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5483 while (vp != NULL) { 5484 if (vp->v_type == VMARKER) { 5485 vp = TAILQ_NEXT(vp, v_actfreelist); 5486 continue; 5487 } 5488 /* 5489 * Try-lock because this is the wrong lock order. If that does 5490 * not succeed, drop the mount vnode list lock and try to 5491 * reacquire it and the vnode interlock in the right order. 5492 */ 5493 if (!VI_TRYLOCK(vp) && 5494 !mnt_vnode_next_active_relock(*mvp, mp, vp)) 5495 goto restart; 5496 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5497 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5498 ("alien vnode on the active list %p %p", vp, mp)); 5499 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) 5500 break; 5501 nvp = TAILQ_NEXT(vp, v_actfreelist); 5502 VI_UNLOCK(vp); 5503 vp = nvp; 5504 } 5505 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5506 5507 /* Check if we are done */ 5508 if (vp == NULL) { 5509 mtx_unlock(&mp->mnt_listmtx); 5510 mnt_vnode_markerfree_active(mvp, mp); 5511 return (NULL); 5512 } 5513 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 5514 mtx_unlock(&mp->mnt_listmtx); 5515 ASSERT_VI_LOCKED(vp, "active iter"); 5516 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 5517 return (vp); 5518 } 5519 5520 struct vnode * 5521 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5522 { 5523 5524 if (should_yield()) 5525 kern_yield(PRI_USER); 5526 mtx_lock(&mp->mnt_listmtx); 5527 return (mnt_vnode_next_active(mvp, mp)); 5528 } 5529 5530 struct vnode * 5531 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 5532 { 5533 struct vnode *vp; 5534 5535 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5536 MNT_ILOCK(mp); 5537 MNT_REF(mp); 5538 MNT_IUNLOCK(mp); 5539 (*mvp)->v_type = VMARKER; 5540 (*mvp)->v_mount = mp; 5541 5542 mtx_lock(&mp->mnt_listmtx); 5543 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 5544 if (vp == NULL) { 5545 mtx_unlock(&mp->mnt_listmtx); 5546 mnt_vnode_markerfree_active(mvp, mp); 5547 return (NULL); 5548 } 5549 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5550 return (mnt_vnode_next_active(mvp, mp)); 5551 } 5552 5553 void 5554 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5555 { 5556 5557 if (*mvp == NULL) 5558 return; 5559 5560 mtx_lock(&mp->mnt_listmtx); 5561 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5562 mtx_unlock(&mp->mnt_listmtx); 5563 mnt_vnode_markerfree_active(mvp, mp); 5564 } 5565