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 BO_UNLOCK(bo); 1677 if (bo->bo_object != NULL) { 1678 VM_OBJECT_WLOCK(bo->bo_object); 1679 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1680 VM_OBJECT_WUNLOCK(bo->bo_object); 1681 } 1682 BO_LOCK(bo); 1683 } while (bo->bo_numoutput > 0); 1684 BO_UNLOCK(bo); 1685 1686 /* 1687 * Destroy the copy in the VM cache, too. 1688 */ 1689 if (bo->bo_object != NULL && 1690 (flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) { 1691 VM_OBJECT_WLOCK(bo->bo_object); 1692 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1693 OBJPR_CLEANONLY : 0); 1694 VM_OBJECT_WUNLOCK(bo->bo_object); 1695 } 1696 1697 #ifdef INVARIANTS 1698 BO_LOCK(bo); 1699 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 && 1700 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0)) 1701 panic("vinvalbuf: flush failed"); 1702 BO_UNLOCK(bo); 1703 #endif 1704 return (0); 1705 } 1706 1707 /* 1708 * Flush out and invalidate all buffers associated with a vnode. 1709 * Called with the underlying object locked. 1710 */ 1711 int 1712 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1713 { 1714 1715 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1716 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1717 if (vp->v_object != NULL && vp->v_object->handle != vp) 1718 return (0); 1719 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1720 } 1721 1722 /* 1723 * Flush out buffers on the specified list. 1724 * 1725 */ 1726 static int 1727 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1728 int slptimeo) 1729 { 1730 struct buf *bp, *nbp; 1731 int retval, error; 1732 daddr_t lblkno; 1733 b_xflags_t xflags; 1734 1735 ASSERT_BO_WLOCKED(bo); 1736 1737 retval = 0; 1738 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1739 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1740 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1741 continue; 1742 } 1743 lblkno = 0; 1744 xflags = 0; 1745 if (nbp != NULL) { 1746 lblkno = nbp->b_lblkno; 1747 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1748 } 1749 retval = EAGAIN; 1750 error = BUF_TIMELOCK(bp, 1751 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1752 "flushbuf", slpflag, slptimeo); 1753 if (error) { 1754 BO_LOCK(bo); 1755 return (error != ENOLCK ? error : EAGAIN); 1756 } 1757 KASSERT(bp->b_bufobj == bo, 1758 ("bp %p wrong b_bufobj %p should be %p", 1759 bp, bp->b_bufobj, bo)); 1760 /* 1761 * XXX Since there are no node locks for NFS, I 1762 * believe there is a slight chance that a delayed 1763 * write will occur while sleeping just above, so 1764 * check for it. 1765 */ 1766 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1767 (flags & V_SAVE)) { 1768 bremfree(bp); 1769 bp->b_flags |= B_ASYNC; 1770 bwrite(bp); 1771 BO_LOCK(bo); 1772 return (EAGAIN); /* XXX: why not loop ? */ 1773 } 1774 bremfree(bp); 1775 bp->b_flags |= (B_INVAL | B_RELBUF); 1776 bp->b_flags &= ~B_ASYNC; 1777 brelse(bp); 1778 BO_LOCK(bo); 1779 nbp = gbincore(bo, lblkno); 1780 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1781 != xflags) 1782 break; /* nbp invalid */ 1783 } 1784 return (retval); 1785 } 1786 1787 int 1788 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) 1789 { 1790 struct buf *bp; 1791 int error; 1792 daddr_t lblkno; 1793 1794 ASSERT_BO_LOCKED(bo); 1795 1796 for (lblkno = startn;;) { 1797 again: 1798 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); 1799 if (bp == NULL || bp->b_lblkno >= endn || 1800 bp->b_lblkno < startn) 1801 break; 1802 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | 1803 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); 1804 if (error != 0) { 1805 BO_RLOCK(bo); 1806 if (error == ENOLCK) 1807 goto again; 1808 return (error); 1809 } 1810 KASSERT(bp->b_bufobj == bo, 1811 ("bp %p wrong b_bufobj %p should be %p", 1812 bp, bp->b_bufobj, bo)); 1813 lblkno = bp->b_lblkno + 1; 1814 if ((bp->b_flags & B_MANAGED) == 0) 1815 bremfree(bp); 1816 bp->b_flags |= B_RELBUF; 1817 /* 1818 * In the VMIO case, use the B_NOREUSE flag to hint that the 1819 * pages backing each buffer in the range are unlikely to be 1820 * reused. Dirty buffers will have the hint applied once 1821 * they've been written. 1822 */ 1823 if (bp->b_vp->v_object != NULL) 1824 bp->b_flags |= B_NOREUSE; 1825 brelse(bp); 1826 BO_RLOCK(bo); 1827 } 1828 return (0); 1829 } 1830 1831 /* 1832 * Truncate a file's buffer and pages to a specified length. This 1833 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1834 * sync activity. 1835 */ 1836 int 1837 vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize) 1838 { 1839 struct buf *bp, *nbp; 1840 int anyfreed; 1841 int trunclbn; 1842 struct bufobj *bo; 1843 1844 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__, 1845 vp, cred, blksize, (uintmax_t)length); 1846 1847 /* 1848 * Round up to the *next* lbn. 1849 */ 1850 trunclbn = howmany(length, blksize); 1851 1852 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1853 restart: 1854 bo = &vp->v_bufobj; 1855 BO_LOCK(bo); 1856 anyfreed = 1; 1857 for (;anyfreed;) { 1858 anyfreed = 0; 1859 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1860 if (bp->b_lblkno < trunclbn) 1861 continue; 1862 if (BUF_LOCK(bp, 1863 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1864 BO_LOCKPTR(bo)) == ENOLCK) 1865 goto restart; 1866 1867 bremfree(bp); 1868 bp->b_flags |= (B_INVAL | B_RELBUF); 1869 bp->b_flags &= ~B_ASYNC; 1870 brelse(bp); 1871 anyfreed = 1; 1872 1873 BO_LOCK(bo); 1874 if (nbp != NULL && 1875 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1876 (nbp->b_vp != vp) || 1877 (nbp->b_flags & B_DELWRI))) { 1878 BO_UNLOCK(bo); 1879 goto restart; 1880 } 1881 } 1882 1883 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1884 if (bp->b_lblkno < trunclbn) 1885 continue; 1886 if (BUF_LOCK(bp, 1887 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1888 BO_LOCKPTR(bo)) == ENOLCK) 1889 goto restart; 1890 bremfree(bp); 1891 bp->b_flags |= (B_INVAL | B_RELBUF); 1892 bp->b_flags &= ~B_ASYNC; 1893 brelse(bp); 1894 anyfreed = 1; 1895 1896 BO_LOCK(bo); 1897 if (nbp != NULL && 1898 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1899 (nbp->b_vp != vp) || 1900 (nbp->b_flags & B_DELWRI) == 0)) { 1901 BO_UNLOCK(bo); 1902 goto restart; 1903 } 1904 } 1905 } 1906 1907 if (length > 0) { 1908 restartsync: 1909 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1910 if (bp->b_lblkno > 0) 1911 continue; 1912 /* 1913 * Since we hold the vnode lock this should only 1914 * fail if we're racing with the buf daemon. 1915 */ 1916 if (BUF_LOCK(bp, 1917 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1918 BO_LOCKPTR(bo)) == ENOLCK) { 1919 goto restart; 1920 } 1921 VNASSERT((bp->b_flags & B_DELWRI), vp, 1922 ("buf(%p) on dirty queue without DELWRI", bp)); 1923 1924 bremfree(bp); 1925 bawrite(bp); 1926 BO_LOCK(bo); 1927 goto restartsync; 1928 } 1929 } 1930 1931 bufobj_wwait(bo, 0, 0); 1932 BO_UNLOCK(bo); 1933 vnode_pager_setsize(vp, length); 1934 1935 return (0); 1936 } 1937 1938 static void 1939 buf_vlist_remove(struct buf *bp) 1940 { 1941 struct bufv *bv; 1942 1943 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1944 ASSERT_BO_WLOCKED(bp->b_bufobj); 1945 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1946 (BX_VNDIRTY|BX_VNCLEAN), 1947 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1948 if (bp->b_xflags & BX_VNDIRTY) 1949 bv = &bp->b_bufobj->bo_dirty; 1950 else 1951 bv = &bp->b_bufobj->bo_clean; 1952 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 1953 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1954 bv->bv_cnt--; 1955 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1956 } 1957 1958 /* 1959 * Add the buffer to the sorted clean or dirty block list. 1960 * 1961 * NOTE: xflags is passed as a constant, optimizing this inline function! 1962 */ 1963 static void 1964 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1965 { 1966 struct bufv *bv; 1967 struct buf *n; 1968 int error; 1969 1970 ASSERT_BO_WLOCKED(bo); 1971 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 1972 ("dead bo %p", bo)); 1973 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1974 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1975 bp->b_xflags |= xflags; 1976 if (xflags & BX_VNDIRTY) 1977 bv = &bo->bo_dirty; 1978 else 1979 bv = &bo->bo_clean; 1980 1981 /* 1982 * Keep the list ordered. Optimize empty list insertion. Assume 1983 * we tend to grow at the tail so lookup_le should usually be cheaper 1984 * than _ge. 1985 */ 1986 if (bv->bv_cnt == 0 || 1987 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 1988 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1989 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 1990 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 1991 else 1992 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 1993 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 1994 if (error) 1995 panic("buf_vlist_add: Preallocated nodes insufficient."); 1996 bv->bv_cnt++; 1997 } 1998 1999 /* 2000 * Look up a buffer using the buffer tries. 2001 */ 2002 struct buf * 2003 gbincore(struct bufobj *bo, daddr_t lblkno) 2004 { 2005 struct buf *bp; 2006 2007 ASSERT_BO_LOCKED(bo); 2008 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 2009 if (bp != NULL) 2010 return (bp); 2011 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 2012 } 2013 2014 /* 2015 * Associate a buffer with a vnode. 2016 */ 2017 void 2018 bgetvp(struct vnode *vp, struct buf *bp) 2019 { 2020 struct bufobj *bo; 2021 2022 bo = &vp->v_bufobj; 2023 ASSERT_BO_WLOCKED(bo); 2024 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 2025 2026 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 2027 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 2028 ("bgetvp: bp already attached! %p", bp)); 2029 2030 vhold(vp); 2031 bp->b_vp = vp; 2032 bp->b_bufobj = bo; 2033 /* 2034 * Insert onto list for new vnode. 2035 */ 2036 buf_vlist_add(bp, bo, BX_VNCLEAN); 2037 } 2038 2039 /* 2040 * Disassociate a buffer from a vnode. 2041 */ 2042 void 2043 brelvp(struct buf *bp) 2044 { 2045 struct bufobj *bo; 2046 struct vnode *vp; 2047 2048 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 2049 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 2050 2051 /* 2052 * Delete from old vnode list, if on one. 2053 */ 2054 vp = bp->b_vp; /* XXX */ 2055 bo = bp->b_bufobj; 2056 BO_LOCK(bo); 2057 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2058 buf_vlist_remove(bp); 2059 else 2060 panic("brelvp: Buffer %p not on queue.", bp); 2061 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2062 bo->bo_flag &= ~BO_ONWORKLST; 2063 mtx_lock(&sync_mtx); 2064 LIST_REMOVE(bo, bo_synclist); 2065 syncer_worklist_len--; 2066 mtx_unlock(&sync_mtx); 2067 } 2068 bp->b_vp = NULL; 2069 bp->b_bufobj = NULL; 2070 BO_UNLOCK(bo); 2071 vdrop(vp); 2072 } 2073 2074 /* 2075 * Add an item to the syncer work queue. 2076 */ 2077 static void 2078 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 2079 { 2080 int slot; 2081 2082 ASSERT_BO_WLOCKED(bo); 2083 2084 mtx_lock(&sync_mtx); 2085 if (bo->bo_flag & BO_ONWORKLST) 2086 LIST_REMOVE(bo, bo_synclist); 2087 else { 2088 bo->bo_flag |= BO_ONWORKLST; 2089 syncer_worklist_len++; 2090 } 2091 2092 if (delay > syncer_maxdelay - 2) 2093 delay = syncer_maxdelay - 2; 2094 slot = (syncer_delayno + delay) & syncer_mask; 2095 2096 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 2097 mtx_unlock(&sync_mtx); 2098 } 2099 2100 static int 2101 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 2102 { 2103 int error, len; 2104 2105 mtx_lock(&sync_mtx); 2106 len = syncer_worklist_len - sync_vnode_count; 2107 mtx_unlock(&sync_mtx); 2108 error = SYSCTL_OUT(req, &len, sizeof(len)); 2109 return (error); 2110 } 2111 2112 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 2113 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 2114 2115 static struct proc *updateproc; 2116 static void sched_sync(void); 2117 static struct kproc_desc up_kp = { 2118 "syncer", 2119 sched_sync, 2120 &updateproc 2121 }; 2122 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 2123 2124 static int 2125 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 2126 { 2127 struct vnode *vp; 2128 struct mount *mp; 2129 2130 *bo = LIST_FIRST(slp); 2131 if (*bo == NULL) 2132 return (0); 2133 vp = bo2vnode(*bo); 2134 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 2135 return (1); 2136 /* 2137 * We use vhold in case the vnode does not 2138 * successfully sync. vhold prevents the vnode from 2139 * going away when we unlock the sync_mtx so that 2140 * we can acquire the vnode interlock. 2141 */ 2142 vholdl(vp); 2143 mtx_unlock(&sync_mtx); 2144 VI_UNLOCK(vp); 2145 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2146 vdrop(vp); 2147 mtx_lock(&sync_mtx); 2148 return (*bo == LIST_FIRST(slp)); 2149 } 2150 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2151 (void) VOP_FSYNC(vp, MNT_LAZY, td); 2152 VOP_UNLOCK(vp, 0); 2153 vn_finished_write(mp); 2154 BO_LOCK(*bo); 2155 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 2156 /* 2157 * Put us back on the worklist. The worklist 2158 * routine will remove us from our current 2159 * position and then add us back in at a later 2160 * position. 2161 */ 2162 vn_syncer_add_to_worklist(*bo, syncdelay); 2163 } 2164 BO_UNLOCK(*bo); 2165 vdrop(vp); 2166 mtx_lock(&sync_mtx); 2167 return (0); 2168 } 2169 2170 static int first_printf = 1; 2171 2172 /* 2173 * System filesystem synchronizer daemon. 2174 */ 2175 static void 2176 sched_sync(void) 2177 { 2178 struct synclist *next, *slp; 2179 struct bufobj *bo; 2180 long starttime; 2181 struct thread *td = curthread; 2182 int last_work_seen; 2183 int net_worklist_len; 2184 int syncer_final_iter; 2185 int error; 2186 2187 last_work_seen = 0; 2188 syncer_final_iter = 0; 2189 syncer_state = SYNCER_RUNNING; 2190 starttime = time_uptime; 2191 td->td_pflags |= TDP_NORUNNINGBUF; 2192 2193 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2194 SHUTDOWN_PRI_LAST); 2195 2196 mtx_lock(&sync_mtx); 2197 for (;;) { 2198 if (syncer_state == SYNCER_FINAL_DELAY && 2199 syncer_final_iter == 0) { 2200 mtx_unlock(&sync_mtx); 2201 kproc_suspend_check(td->td_proc); 2202 mtx_lock(&sync_mtx); 2203 } 2204 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2205 if (syncer_state != SYNCER_RUNNING && 2206 starttime != time_uptime) { 2207 if (first_printf) { 2208 printf("\nSyncing disks, vnodes remaining... "); 2209 first_printf = 0; 2210 } 2211 printf("%d ", net_worklist_len); 2212 } 2213 starttime = time_uptime; 2214 2215 /* 2216 * Push files whose dirty time has expired. Be careful 2217 * of interrupt race on slp queue. 2218 * 2219 * Skip over empty worklist slots when shutting down. 2220 */ 2221 do { 2222 slp = &syncer_workitem_pending[syncer_delayno]; 2223 syncer_delayno += 1; 2224 if (syncer_delayno == syncer_maxdelay) 2225 syncer_delayno = 0; 2226 next = &syncer_workitem_pending[syncer_delayno]; 2227 /* 2228 * If the worklist has wrapped since the 2229 * it was emptied of all but syncer vnodes, 2230 * switch to the FINAL_DELAY state and run 2231 * for one more second. 2232 */ 2233 if (syncer_state == SYNCER_SHUTTING_DOWN && 2234 net_worklist_len == 0 && 2235 last_work_seen == syncer_delayno) { 2236 syncer_state = SYNCER_FINAL_DELAY; 2237 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2238 } 2239 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2240 syncer_worklist_len > 0); 2241 2242 /* 2243 * Keep track of the last time there was anything 2244 * on the worklist other than syncer vnodes. 2245 * Return to the SHUTTING_DOWN state if any 2246 * new work appears. 2247 */ 2248 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2249 last_work_seen = syncer_delayno; 2250 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2251 syncer_state = SYNCER_SHUTTING_DOWN; 2252 while (!LIST_EMPTY(slp)) { 2253 error = sync_vnode(slp, &bo, td); 2254 if (error == 1) { 2255 LIST_REMOVE(bo, bo_synclist); 2256 LIST_INSERT_HEAD(next, bo, bo_synclist); 2257 continue; 2258 } 2259 2260 if (first_printf == 0) { 2261 /* 2262 * Drop the sync mutex, because some watchdog 2263 * drivers need to sleep while patting 2264 */ 2265 mtx_unlock(&sync_mtx); 2266 wdog_kern_pat(WD_LASTVAL); 2267 mtx_lock(&sync_mtx); 2268 } 2269 2270 } 2271 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2272 syncer_final_iter--; 2273 /* 2274 * The variable rushjob allows the kernel to speed up the 2275 * processing of the filesystem syncer process. A rushjob 2276 * value of N tells the filesystem syncer to process the next 2277 * N seconds worth of work on its queue ASAP. Currently rushjob 2278 * is used by the soft update code to speed up the filesystem 2279 * syncer process when the incore state is getting so far 2280 * ahead of the disk that the kernel memory pool is being 2281 * threatened with exhaustion. 2282 */ 2283 if (rushjob > 0) { 2284 rushjob -= 1; 2285 continue; 2286 } 2287 /* 2288 * Just sleep for a short period of time between 2289 * iterations when shutting down to allow some I/O 2290 * to happen. 2291 * 2292 * If it has taken us less than a second to process the 2293 * current work, then wait. Otherwise start right over 2294 * again. We can still lose time if any single round 2295 * takes more than two seconds, but it does not really 2296 * matter as we are just trying to generally pace the 2297 * filesystem activity. 2298 */ 2299 if (syncer_state != SYNCER_RUNNING || 2300 time_uptime == starttime) { 2301 thread_lock(td); 2302 sched_prio(td, PPAUSE); 2303 thread_unlock(td); 2304 } 2305 if (syncer_state != SYNCER_RUNNING) 2306 cv_timedwait(&sync_wakeup, &sync_mtx, 2307 hz / SYNCER_SHUTDOWN_SPEEDUP); 2308 else if (time_uptime == starttime) 2309 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2310 } 2311 } 2312 2313 /* 2314 * Request the syncer daemon to speed up its work. 2315 * We never push it to speed up more than half of its 2316 * normal turn time, otherwise it could take over the cpu. 2317 */ 2318 int 2319 speedup_syncer(void) 2320 { 2321 int ret = 0; 2322 2323 mtx_lock(&sync_mtx); 2324 if (rushjob < syncdelay / 2) { 2325 rushjob += 1; 2326 stat_rush_requests += 1; 2327 ret = 1; 2328 } 2329 mtx_unlock(&sync_mtx); 2330 cv_broadcast(&sync_wakeup); 2331 return (ret); 2332 } 2333 2334 /* 2335 * Tell the syncer to speed up its work and run though its work 2336 * list several times, then tell it to shut down. 2337 */ 2338 static void 2339 syncer_shutdown(void *arg, int howto) 2340 { 2341 2342 if (howto & RB_NOSYNC) 2343 return; 2344 mtx_lock(&sync_mtx); 2345 syncer_state = SYNCER_SHUTTING_DOWN; 2346 rushjob = 0; 2347 mtx_unlock(&sync_mtx); 2348 cv_broadcast(&sync_wakeup); 2349 kproc_shutdown(arg, howto); 2350 } 2351 2352 void 2353 syncer_suspend(void) 2354 { 2355 2356 syncer_shutdown(updateproc, 0); 2357 } 2358 2359 void 2360 syncer_resume(void) 2361 { 2362 2363 mtx_lock(&sync_mtx); 2364 first_printf = 1; 2365 syncer_state = SYNCER_RUNNING; 2366 mtx_unlock(&sync_mtx); 2367 cv_broadcast(&sync_wakeup); 2368 kproc_resume(updateproc); 2369 } 2370 2371 /* 2372 * Reassign a buffer from one vnode to another. 2373 * Used to assign file specific control information 2374 * (indirect blocks) to the vnode to which they belong. 2375 */ 2376 void 2377 reassignbuf(struct buf *bp) 2378 { 2379 struct vnode *vp; 2380 struct bufobj *bo; 2381 int delay; 2382 #ifdef INVARIANTS 2383 struct bufv *bv; 2384 #endif 2385 2386 vp = bp->b_vp; 2387 bo = bp->b_bufobj; 2388 ++reassignbufcalls; 2389 2390 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2391 bp, bp->b_vp, bp->b_flags); 2392 /* 2393 * B_PAGING flagged buffers cannot be reassigned because their vp 2394 * is not fully linked in. 2395 */ 2396 if (bp->b_flags & B_PAGING) 2397 panic("cannot reassign paging buffer"); 2398 2399 /* 2400 * Delete from old vnode list, if on one. 2401 */ 2402 BO_LOCK(bo); 2403 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2404 buf_vlist_remove(bp); 2405 else 2406 panic("reassignbuf: Buffer %p not on queue.", bp); 2407 /* 2408 * If dirty, put on list of dirty buffers; otherwise insert onto list 2409 * of clean buffers. 2410 */ 2411 if (bp->b_flags & B_DELWRI) { 2412 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2413 switch (vp->v_type) { 2414 case VDIR: 2415 delay = dirdelay; 2416 break; 2417 case VCHR: 2418 delay = metadelay; 2419 break; 2420 default: 2421 delay = filedelay; 2422 } 2423 vn_syncer_add_to_worklist(bo, delay); 2424 } 2425 buf_vlist_add(bp, bo, BX_VNDIRTY); 2426 } else { 2427 buf_vlist_add(bp, bo, BX_VNCLEAN); 2428 2429 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2430 mtx_lock(&sync_mtx); 2431 LIST_REMOVE(bo, bo_synclist); 2432 syncer_worklist_len--; 2433 mtx_unlock(&sync_mtx); 2434 bo->bo_flag &= ~BO_ONWORKLST; 2435 } 2436 } 2437 #ifdef INVARIANTS 2438 bv = &bo->bo_clean; 2439 bp = TAILQ_FIRST(&bv->bv_hd); 2440 KASSERT(bp == NULL || bp->b_bufobj == bo, 2441 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2442 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2443 KASSERT(bp == NULL || bp->b_bufobj == bo, 2444 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2445 bv = &bo->bo_dirty; 2446 bp = TAILQ_FIRST(&bv->bv_hd); 2447 KASSERT(bp == NULL || bp->b_bufobj == bo, 2448 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2449 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2450 KASSERT(bp == NULL || bp->b_bufobj == bo, 2451 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2452 #endif 2453 BO_UNLOCK(bo); 2454 } 2455 2456 /* 2457 * A temporary hack until refcount_* APIs are sorted out. 2458 */ 2459 static __inline int 2460 vfs_refcount_acquire_if_not_zero(volatile u_int *count) 2461 { 2462 u_int old; 2463 2464 old = *count; 2465 for (;;) { 2466 if (old == 0) 2467 return (0); 2468 if (atomic_fcmpset_int(count, &old, old + 1)) 2469 return (1); 2470 } 2471 } 2472 2473 static __inline int 2474 vfs_refcount_release_if_not_last(volatile u_int *count) 2475 { 2476 u_int old; 2477 2478 old = *count; 2479 for (;;) { 2480 if (old == 1) 2481 return (0); 2482 if (atomic_fcmpset_int(count, &old, old - 1)) 2483 return (1); 2484 } 2485 } 2486 2487 static void 2488 v_init_counters(struct vnode *vp) 2489 { 2490 2491 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2492 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2493 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2494 2495 refcount_init(&vp->v_holdcnt, 1); 2496 refcount_init(&vp->v_usecount, 1); 2497 } 2498 2499 static void 2500 v_incr_usecount_locked(struct vnode *vp) 2501 { 2502 2503 ASSERT_VI_LOCKED(vp, __func__); 2504 if ((vp->v_iflag & VI_OWEINACT) != 0) { 2505 VNASSERT(vp->v_usecount == 0, vp, 2506 ("vnode with usecount and VI_OWEINACT set")); 2507 vp->v_iflag &= ~VI_OWEINACT; 2508 } 2509 refcount_acquire(&vp->v_usecount); 2510 v_incr_devcount(vp); 2511 } 2512 2513 /* 2514 * Increment the use count on the vnode, taking care to reference 2515 * the driver's usecount if this is a chardev. 2516 */ 2517 static void 2518 v_incr_usecount(struct vnode *vp) 2519 { 2520 2521 ASSERT_VI_UNLOCKED(vp, __func__); 2522 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2523 2524 if (vp->v_type != VCHR && 2525 vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) { 2526 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2527 ("vnode with usecount and VI_OWEINACT set")); 2528 } else { 2529 VI_LOCK(vp); 2530 v_incr_usecount_locked(vp); 2531 VI_UNLOCK(vp); 2532 } 2533 } 2534 2535 /* 2536 * Increment si_usecount of the associated device, if any. 2537 */ 2538 static void 2539 v_incr_devcount(struct vnode *vp) 2540 { 2541 2542 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2543 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2544 dev_lock(); 2545 vp->v_rdev->si_usecount++; 2546 dev_unlock(); 2547 } 2548 } 2549 2550 /* 2551 * Decrement si_usecount of the associated device, if any. 2552 */ 2553 static void 2554 v_decr_devcount(struct vnode *vp) 2555 { 2556 2557 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2558 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2559 dev_lock(); 2560 vp->v_rdev->si_usecount--; 2561 dev_unlock(); 2562 } 2563 } 2564 2565 /* 2566 * Grab a particular vnode from the free list, increment its 2567 * reference count and lock it. VI_DOOMED is set if the vnode 2568 * is being destroyed. Only callers who specify LK_RETRY will 2569 * see doomed vnodes. If inactive processing was delayed in 2570 * vput try to do it here. 2571 * 2572 * Notes on lockless counter manipulation: 2573 * _vhold, vputx and other routines make various decisions based 2574 * on either holdcnt or usecount being 0. As long as either counter 2575 * is not transitioning 0->1 nor 1->0, the manipulation can be done 2576 * with atomic operations. Otherwise the interlock is taken covering 2577 * both the atomic and additional actions. 2578 */ 2579 int 2580 vget(struct vnode *vp, int flags, struct thread *td) 2581 { 2582 int error, oweinact; 2583 2584 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2585 ("vget: invalid lock operation")); 2586 2587 if ((flags & LK_INTERLOCK) != 0) 2588 ASSERT_VI_LOCKED(vp, __func__); 2589 else 2590 ASSERT_VI_UNLOCKED(vp, __func__); 2591 if ((flags & LK_VNHELD) != 0) 2592 VNASSERT((vp->v_holdcnt > 0), vp, 2593 ("vget: LK_VNHELD passed but vnode not held")); 2594 2595 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2596 2597 if ((flags & LK_VNHELD) == 0) 2598 _vhold(vp, (flags & LK_INTERLOCK) != 0); 2599 2600 if ((error = vn_lock(vp, flags)) != 0) { 2601 vdrop(vp); 2602 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2603 vp); 2604 return (error); 2605 } 2606 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2607 panic("vget: vn_lock failed to return ENOENT\n"); 2608 /* 2609 * We don't guarantee that any particular close will 2610 * trigger inactive processing so just make a best effort 2611 * here at preventing a reference to a removed file. If 2612 * we don't succeed no harm is done. 2613 * 2614 * Upgrade our holdcnt to a usecount. 2615 */ 2616 if (vp->v_type == VCHR || 2617 !vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) { 2618 VI_LOCK(vp); 2619 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2620 oweinact = 0; 2621 } else { 2622 oweinact = 1; 2623 vp->v_iflag &= ~VI_OWEINACT; 2624 } 2625 refcount_acquire(&vp->v_usecount); 2626 v_incr_devcount(vp); 2627 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2628 (flags & LK_NOWAIT) == 0) 2629 vinactive(vp, td); 2630 VI_UNLOCK(vp); 2631 } 2632 return (0); 2633 } 2634 2635 /* 2636 * Increase the reference (use) and hold count of a vnode. 2637 * This will also remove the vnode from the free list if it is presently free. 2638 */ 2639 void 2640 vref(struct vnode *vp) 2641 { 2642 2643 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2644 _vhold(vp, false); 2645 v_incr_usecount(vp); 2646 } 2647 2648 void 2649 vrefl(struct vnode *vp) 2650 { 2651 2652 ASSERT_VI_LOCKED(vp, __func__); 2653 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2654 _vhold(vp, true); 2655 v_incr_usecount_locked(vp); 2656 } 2657 2658 void 2659 vrefact(struct vnode *vp) 2660 { 2661 2662 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2663 if (__predict_false(vp->v_type == VCHR)) { 2664 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, 2665 ("%s: wrong ref counts", __func__)); 2666 vref(vp); 2667 return; 2668 } 2669 #ifdef INVARIANTS 2670 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); 2671 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__)); 2672 old = atomic_fetchadd_int(&vp->v_usecount, 1); 2673 VNASSERT(old > 0, vp, ("%s: wrong use count", __func__)); 2674 #else 2675 refcount_acquire(&vp->v_holdcnt); 2676 refcount_acquire(&vp->v_usecount); 2677 #endif 2678 } 2679 2680 /* 2681 * Return reference count of a vnode. 2682 * 2683 * The results of this call are only guaranteed when some mechanism is used to 2684 * stop other processes from gaining references to the vnode. This may be the 2685 * case if the caller holds the only reference. This is also useful when stale 2686 * data is acceptable as race conditions may be accounted for by some other 2687 * means. 2688 */ 2689 int 2690 vrefcnt(struct vnode *vp) 2691 { 2692 2693 return (vp->v_usecount); 2694 } 2695 2696 #define VPUTX_VRELE 1 2697 #define VPUTX_VPUT 2 2698 #define VPUTX_VUNREF 3 2699 2700 /* 2701 * Decrement the use and hold counts for a vnode. 2702 * 2703 * See an explanation near vget() as to why atomic operation is safe. 2704 */ 2705 static void 2706 vputx(struct vnode *vp, int func) 2707 { 2708 int error; 2709 2710 KASSERT(vp != NULL, ("vputx: null vp")); 2711 if (func == VPUTX_VUNREF) 2712 ASSERT_VOP_LOCKED(vp, "vunref"); 2713 else if (func == VPUTX_VPUT) 2714 ASSERT_VOP_LOCKED(vp, "vput"); 2715 else 2716 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); 2717 ASSERT_VI_UNLOCKED(vp, __func__); 2718 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2719 2720 if (vp->v_type != VCHR && 2721 vfs_refcount_release_if_not_last(&vp->v_usecount)) { 2722 if (func == VPUTX_VPUT) 2723 VOP_UNLOCK(vp, 0); 2724 vdrop(vp); 2725 return; 2726 } 2727 2728 VI_LOCK(vp); 2729 2730 /* 2731 * We want to hold the vnode until the inactive finishes to 2732 * prevent vgone() races. We drop the use count here and the 2733 * hold count below when we're done. 2734 */ 2735 if (!refcount_release(&vp->v_usecount) || 2736 (vp->v_iflag & VI_DOINGINACT)) { 2737 if (func == VPUTX_VPUT) 2738 VOP_UNLOCK(vp, 0); 2739 v_decr_devcount(vp); 2740 vdropl(vp); 2741 return; 2742 } 2743 2744 v_decr_devcount(vp); 2745 2746 error = 0; 2747 2748 if (vp->v_usecount != 0) { 2749 vn_printf(vp, "vputx: usecount not zero for vnode "); 2750 panic("vputx: usecount not zero"); 2751 } 2752 2753 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); 2754 2755 /* 2756 * We must call VOP_INACTIVE with the node locked. Mark 2757 * as VI_DOINGINACT to avoid recursion. 2758 */ 2759 vp->v_iflag |= VI_OWEINACT; 2760 switch (func) { 2761 case VPUTX_VRELE: 2762 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2763 VI_LOCK(vp); 2764 break; 2765 case VPUTX_VPUT: 2766 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2767 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 2768 LK_NOWAIT); 2769 VI_LOCK(vp); 2770 } 2771 break; 2772 case VPUTX_VUNREF: 2773 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2774 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 2775 VI_LOCK(vp); 2776 } 2777 break; 2778 } 2779 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, 2780 ("vnode with usecount and VI_OWEINACT set")); 2781 if (error == 0) { 2782 if (vp->v_iflag & VI_OWEINACT) 2783 vinactive(vp, curthread); 2784 if (func != VPUTX_VUNREF) 2785 VOP_UNLOCK(vp, 0); 2786 } 2787 vdropl(vp); 2788 } 2789 2790 /* 2791 * Vnode put/release. 2792 * If count drops to zero, call inactive routine and return to freelist. 2793 */ 2794 void 2795 vrele(struct vnode *vp) 2796 { 2797 2798 vputx(vp, VPUTX_VRELE); 2799 } 2800 2801 /* 2802 * Release an already locked vnode. This give the same effects as 2803 * unlock+vrele(), but takes less time and avoids releasing and 2804 * re-aquiring the lock (as vrele() acquires the lock internally.) 2805 */ 2806 void 2807 vput(struct vnode *vp) 2808 { 2809 2810 vputx(vp, VPUTX_VPUT); 2811 } 2812 2813 /* 2814 * Release an exclusively locked vnode. Do not unlock the vnode lock. 2815 */ 2816 void 2817 vunref(struct vnode *vp) 2818 { 2819 2820 vputx(vp, VPUTX_VUNREF); 2821 } 2822 2823 /* 2824 * Increase the hold count and activate if this is the first reference. 2825 */ 2826 void 2827 _vhold(struct vnode *vp, bool locked) 2828 { 2829 struct mount *mp; 2830 2831 if (locked) 2832 ASSERT_VI_LOCKED(vp, __func__); 2833 else 2834 ASSERT_VI_UNLOCKED(vp, __func__); 2835 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2836 if (!locked && vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt)) { 2837 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2838 ("_vhold: vnode with holdcnt is free")); 2839 return; 2840 } 2841 2842 if (!locked) 2843 VI_LOCK(vp); 2844 if ((vp->v_iflag & VI_FREE) == 0) { 2845 refcount_acquire(&vp->v_holdcnt); 2846 if (!locked) 2847 VI_UNLOCK(vp); 2848 return; 2849 } 2850 VNASSERT(vp->v_holdcnt == 0, vp, 2851 ("%s: wrong hold count", __func__)); 2852 VNASSERT(vp->v_op != NULL, vp, 2853 ("%s: vnode already reclaimed.", __func__)); 2854 /* 2855 * Remove a vnode from the free list, mark it as in use, 2856 * and put it on the active list. 2857 */ 2858 mp = vp->v_mount; 2859 mtx_lock(&mp->mnt_listmtx); 2860 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { 2861 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); 2862 mp->mnt_tmpfreevnodelistsize--; 2863 vp->v_mflag &= ~VMP_TMPMNTFREELIST; 2864 } else { 2865 mtx_lock(&vnode_free_list_mtx); 2866 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 2867 freevnodes--; 2868 mtx_unlock(&vnode_free_list_mtx); 2869 } 2870 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 2871 ("Activating already active vnode")); 2872 vp->v_iflag &= ~VI_FREE; 2873 vp->v_iflag |= VI_ACTIVE; 2874 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 2875 mp->mnt_activevnodelistsize++; 2876 mtx_unlock(&mp->mnt_listmtx); 2877 refcount_acquire(&vp->v_holdcnt); 2878 if (!locked) 2879 VI_UNLOCK(vp); 2880 } 2881 2882 /* 2883 * Drop the hold count of the vnode. If this is the last reference to 2884 * the vnode we place it on the free list unless it has been vgone'd 2885 * (marked VI_DOOMED) in which case we will free it. 2886 * 2887 * Because the vnode vm object keeps a hold reference on the vnode if 2888 * there is at least one resident non-cached page, the vnode cannot 2889 * leave the active list without the page cleanup done. 2890 */ 2891 void 2892 _vdrop(struct vnode *vp, bool locked) 2893 { 2894 struct bufobj *bo; 2895 struct mount *mp; 2896 int active; 2897 2898 if (locked) 2899 ASSERT_VI_LOCKED(vp, __func__); 2900 else 2901 ASSERT_VI_UNLOCKED(vp, __func__); 2902 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2903 if ((int)vp->v_holdcnt <= 0) 2904 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2905 if (vfs_refcount_release_if_not_last(&vp->v_holdcnt)) { 2906 if (locked) 2907 VI_UNLOCK(vp); 2908 return; 2909 } 2910 2911 if (!locked) 2912 VI_LOCK(vp); 2913 if (refcount_release(&vp->v_holdcnt) == 0) { 2914 VI_UNLOCK(vp); 2915 return; 2916 } 2917 if ((vp->v_iflag & VI_DOOMED) == 0) { 2918 /* 2919 * Mark a vnode as free: remove it from its active list 2920 * and put it up for recycling on the freelist. 2921 */ 2922 VNASSERT(vp->v_op != NULL, vp, 2923 ("vdropl: vnode already reclaimed.")); 2924 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2925 ("vnode already free")); 2926 VNASSERT(vp->v_holdcnt == 0, vp, 2927 ("vdropl: freeing when we shouldn't")); 2928 active = vp->v_iflag & VI_ACTIVE; 2929 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2930 vp->v_iflag &= ~VI_ACTIVE; 2931 mp = vp->v_mount; 2932 mtx_lock(&mp->mnt_listmtx); 2933 if (active) { 2934 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, 2935 v_actfreelist); 2936 mp->mnt_activevnodelistsize--; 2937 } 2938 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, vp, 2939 v_actfreelist); 2940 mp->mnt_tmpfreevnodelistsize++; 2941 vp->v_iflag |= VI_FREE; 2942 vp->v_mflag |= VMP_TMPMNTFREELIST; 2943 VI_UNLOCK(vp); 2944 if (mp->mnt_tmpfreevnodelistsize >= mnt_free_list_batch) 2945 vnlru_return_batch_locked(mp); 2946 mtx_unlock(&mp->mnt_listmtx); 2947 } else { 2948 VI_UNLOCK(vp); 2949 counter_u64_add(free_owe_inact, 1); 2950 } 2951 return; 2952 } 2953 /* 2954 * The vnode has been marked for destruction, so free it. 2955 * 2956 * The vnode will be returned to the zone where it will 2957 * normally remain until it is needed for another vnode. We 2958 * need to cleanup (or verify that the cleanup has already 2959 * been done) any residual data left from its current use 2960 * so as not to contaminate the freshly allocated vnode. 2961 */ 2962 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 2963 atomic_subtract_long(&numvnodes, 1); 2964 bo = &vp->v_bufobj; 2965 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2966 ("cleaned vnode still on the free list.")); 2967 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 2968 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 2969 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 2970 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 2971 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 2972 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 2973 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 2974 ("clean blk trie not empty")); 2975 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 2976 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 2977 ("dirty blk trie not empty")); 2978 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 2979 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 2980 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 2981 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, 2982 ("Dangling rangelock waiters")); 2983 VI_UNLOCK(vp); 2984 #ifdef MAC 2985 mac_vnode_destroy(vp); 2986 #endif 2987 if (vp->v_pollinfo != NULL) { 2988 destroy_vpollinfo(vp->v_pollinfo); 2989 vp->v_pollinfo = NULL; 2990 } 2991 #ifdef INVARIANTS 2992 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 2993 vp->v_op = NULL; 2994 #endif 2995 bzero(&vp->v_un, sizeof(vp->v_un)); 2996 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 2997 vp->v_iflag = 0; 2998 vp->v_vflag = 0; 2999 bo->bo_flag = 0; 3000 uma_zfree(vnode_zone, vp); 3001 } 3002 3003 /* 3004 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 3005 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 3006 * OWEINACT tracks whether a vnode missed a call to inactive due to a 3007 * failed lock upgrade. 3008 */ 3009 void 3010 vinactive(struct vnode *vp, struct thread *td) 3011 { 3012 struct vm_object *obj; 3013 3014 ASSERT_VOP_ELOCKED(vp, "vinactive"); 3015 ASSERT_VI_LOCKED(vp, "vinactive"); 3016 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 3017 ("vinactive: recursed on VI_DOINGINACT")); 3018 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3019 vp->v_iflag |= VI_DOINGINACT; 3020 vp->v_iflag &= ~VI_OWEINACT; 3021 VI_UNLOCK(vp); 3022 /* 3023 * Before moving off the active list, we must be sure that any 3024 * modified pages are converted into the vnode's dirty 3025 * buffers, since these will no longer be checked once the 3026 * vnode is on the inactive list. 3027 * 3028 * The write-out of the dirty pages is asynchronous. At the 3029 * point that VOP_INACTIVE() is called, there could still be 3030 * pending I/O and dirty pages in the object. 3031 */ 3032 obj = vp->v_object; 3033 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { 3034 VM_OBJECT_WLOCK(obj); 3035 vm_object_page_clean(obj, 0, 0, 0); 3036 VM_OBJECT_WUNLOCK(obj); 3037 } 3038 VOP_INACTIVE(vp, td); 3039 VI_LOCK(vp); 3040 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 3041 ("vinactive: lost VI_DOINGINACT")); 3042 vp->v_iflag &= ~VI_DOINGINACT; 3043 } 3044 3045 /* 3046 * Remove any vnodes in the vnode table belonging to mount point mp. 3047 * 3048 * If FORCECLOSE is not specified, there should not be any active ones, 3049 * return error if any are found (nb: this is a user error, not a 3050 * system error). If FORCECLOSE is specified, detach any active vnodes 3051 * that are found. 3052 * 3053 * If WRITECLOSE is set, only flush out regular file vnodes open for 3054 * writing. 3055 * 3056 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 3057 * 3058 * `rootrefs' specifies the base reference count for the root vnode 3059 * of this filesystem. The root vnode is considered busy if its 3060 * v_usecount exceeds this value. On a successful return, vflush(, td) 3061 * will call vrele() on the root vnode exactly rootrefs times. 3062 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 3063 * be zero. 3064 */ 3065 #ifdef DIAGNOSTIC 3066 static int busyprt = 0; /* print out busy vnodes */ 3067 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 3068 #endif 3069 3070 int 3071 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 3072 { 3073 struct vnode *vp, *mvp, *rootvp = NULL; 3074 struct vattr vattr; 3075 int busy = 0, error; 3076 3077 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 3078 rootrefs, flags); 3079 if (rootrefs > 0) { 3080 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 3081 ("vflush: bad args")); 3082 /* 3083 * Get the filesystem root vnode. We can vput() it 3084 * immediately, since with rootrefs > 0, it won't go away. 3085 */ 3086 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 3087 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 3088 __func__, error); 3089 return (error); 3090 } 3091 vput(rootvp); 3092 } 3093 loop: 3094 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 3095 vholdl(vp); 3096 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 3097 if (error) { 3098 vdrop(vp); 3099 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3100 goto loop; 3101 } 3102 /* 3103 * Skip over a vnodes marked VV_SYSTEM. 3104 */ 3105 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 3106 VOP_UNLOCK(vp, 0); 3107 vdrop(vp); 3108 continue; 3109 } 3110 /* 3111 * If WRITECLOSE is set, flush out unlinked but still open 3112 * files (even if open only for reading) and regular file 3113 * vnodes open for writing. 3114 */ 3115 if (flags & WRITECLOSE) { 3116 if (vp->v_object != NULL) { 3117 VM_OBJECT_WLOCK(vp->v_object); 3118 vm_object_page_clean(vp->v_object, 0, 0, 0); 3119 VM_OBJECT_WUNLOCK(vp->v_object); 3120 } 3121 error = VOP_FSYNC(vp, MNT_WAIT, td); 3122 if (error != 0) { 3123 VOP_UNLOCK(vp, 0); 3124 vdrop(vp); 3125 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 3126 return (error); 3127 } 3128 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3129 VI_LOCK(vp); 3130 3131 if ((vp->v_type == VNON || 3132 (error == 0 && vattr.va_nlink > 0)) && 3133 (vp->v_writecount == 0 || vp->v_type != VREG)) { 3134 VOP_UNLOCK(vp, 0); 3135 vdropl(vp); 3136 continue; 3137 } 3138 } else 3139 VI_LOCK(vp); 3140 /* 3141 * With v_usecount == 0, all we need to do is clear out the 3142 * vnode data structures and we are done. 3143 * 3144 * If FORCECLOSE is set, forcibly close the vnode. 3145 */ 3146 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 3147 vgonel(vp); 3148 } else { 3149 busy++; 3150 #ifdef DIAGNOSTIC 3151 if (busyprt) 3152 vn_printf(vp, "vflush: busy vnode "); 3153 #endif 3154 } 3155 VOP_UNLOCK(vp, 0); 3156 vdropl(vp); 3157 } 3158 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 3159 /* 3160 * If just the root vnode is busy, and if its refcount 3161 * is equal to `rootrefs', then go ahead and kill it. 3162 */ 3163 VI_LOCK(rootvp); 3164 KASSERT(busy > 0, ("vflush: not busy")); 3165 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 3166 ("vflush: usecount %d < rootrefs %d", 3167 rootvp->v_usecount, rootrefs)); 3168 if (busy == 1 && rootvp->v_usecount == rootrefs) { 3169 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 3170 vgone(rootvp); 3171 VOP_UNLOCK(rootvp, 0); 3172 busy = 0; 3173 } else 3174 VI_UNLOCK(rootvp); 3175 } 3176 if (busy) { 3177 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 3178 busy); 3179 return (EBUSY); 3180 } 3181 for (; rootrefs > 0; rootrefs--) 3182 vrele(rootvp); 3183 return (0); 3184 } 3185 3186 /* 3187 * Recycle an unused vnode to the front of the free list. 3188 */ 3189 int 3190 vrecycle(struct vnode *vp) 3191 { 3192 int recycled; 3193 3194 VI_LOCK(vp); 3195 recycled = vrecyclel(vp); 3196 VI_UNLOCK(vp); 3197 return (recycled); 3198 } 3199 3200 /* 3201 * vrecycle, with the vp interlock held. 3202 */ 3203 int 3204 vrecyclel(struct vnode *vp) 3205 { 3206 int recycled; 3207 3208 ASSERT_VOP_ELOCKED(vp, __func__); 3209 ASSERT_VI_LOCKED(vp, __func__); 3210 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3211 recycled = 0; 3212 if (vp->v_usecount == 0) { 3213 recycled = 1; 3214 vgonel(vp); 3215 } 3216 return (recycled); 3217 } 3218 3219 /* 3220 * Eliminate all activity associated with a vnode 3221 * in preparation for reuse. 3222 */ 3223 void 3224 vgone(struct vnode *vp) 3225 { 3226 VI_LOCK(vp); 3227 vgonel(vp); 3228 VI_UNLOCK(vp); 3229 } 3230 3231 static void 3232 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3233 struct vnode *lowervp __unused) 3234 { 3235 } 3236 3237 /* 3238 * Notify upper mounts about reclaimed or unlinked vnode. 3239 */ 3240 void 3241 vfs_notify_upper(struct vnode *vp, int event) 3242 { 3243 static struct vfsops vgonel_vfsops = { 3244 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3245 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3246 }; 3247 struct mount *mp, *ump, *mmp; 3248 3249 mp = vp->v_mount; 3250 if (mp == NULL) 3251 return; 3252 3253 MNT_ILOCK(mp); 3254 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3255 goto unlock; 3256 MNT_IUNLOCK(mp); 3257 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3258 mmp->mnt_op = &vgonel_vfsops; 3259 mmp->mnt_kern_flag |= MNTK_MARKER; 3260 MNT_ILOCK(mp); 3261 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3262 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3263 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3264 ump = TAILQ_NEXT(ump, mnt_upper_link); 3265 continue; 3266 } 3267 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3268 MNT_IUNLOCK(mp); 3269 switch (event) { 3270 case VFS_NOTIFY_UPPER_RECLAIM: 3271 VFS_RECLAIM_LOWERVP(ump, vp); 3272 break; 3273 case VFS_NOTIFY_UPPER_UNLINK: 3274 VFS_UNLINK_LOWERVP(ump, vp); 3275 break; 3276 default: 3277 KASSERT(0, ("invalid event %d", event)); 3278 break; 3279 } 3280 MNT_ILOCK(mp); 3281 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3282 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3283 } 3284 free(mmp, M_TEMP); 3285 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3286 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3287 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3288 wakeup(&mp->mnt_uppers); 3289 } 3290 unlock: 3291 MNT_IUNLOCK(mp); 3292 } 3293 3294 /* 3295 * vgone, with the vp interlock held. 3296 */ 3297 static void 3298 vgonel(struct vnode *vp) 3299 { 3300 struct thread *td; 3301 int oweinact; 3302 int active; 3303 struct mount *mp; 3304 3305 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3306 ASSERT_VI_LOCKED(vp, "vgonel"); 3307 VNASSERT(vp->v_holdcnt, vp, 3308 ("vgonel: vp %p has no reference.", vp)); 3309 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3310 td = curthread; 3311 3312 /* 3313 * Don't vgonel if we're already doomed. 3314 */ 3315 if (vp->v_iflag & VI_DOOMED) 3316 return; 3317 vp->v_iflag |= VI_DOOMED; 3318 3319 /* 3320 * Check to see if the vnode is in use. If so, we have to call 3321 * VOP_CLOSE() and VOP_INACTIVE(). 3322 */ 3323 active = vp->v_usecount; 3324 oweinact = (vp->v_iflag & VI_OWEINACT); 3325 VI_UNLOCK(vp); 3326 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3327 3328 /* 3329 * If purging an active vnode, it must be closed and 3330 * deactivated before being reclaimed. 3331 */ 3332 if (active) 3333 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3334 if (oweinact || active) { 3335 VI_LOCK(vp); 3336 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3337 vinactive(vp, td); 3338 VI_UNLOCK(vp); 3339 } 3340 if (vp->v_type == VSOCK) 3341 vfs_unp_reclaim(vp); 3342 3343 /* 3344 * Clean out any buffers associated with the vnode. 3345 * If the flush fails, just toss the buffers. 3346 */ 3347 mp = NULL; 3348 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3349 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3350 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3351 while (vinvalbuf(vp, 0, 0, 0) != 0) 3352 ; 3353 } 3354 3355 BO_LOCK(&vp->v_bufobj); 3356 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3357 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3358 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3359 vp->v_bufobj.bo_clean.bv_cnt == 0, 3360 ("vp %p bufobj not invalidated", vp)); 3361 3362 /* 3363 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate() 3364 * after the object's page queue is flushed. 3365 */ 3366 if (vp->v_bufobj.bo_object == NULL) 3367 vp->v_bufobj.bo_flag |= BO_DEAD; 3368 BO_UNLOCK(&vp->v_bufobj); 3369 3370 /* 3371 * Reclaim the vnode. 3372 */ 3373 if (VOP_RECLAIM(vp, td)) 3374 panic("vgone: cannot reclaim"); 3375 if (mp != NULL) 3376 vn_finished_secondary_write(mp); 3377 VNASSERT(vp->v_object == NULL, vp, 3378 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3379 /* 3380 * Clear the advisory locks and wake up waiting threads. 3381 */ 3382 (void)VOP_ADVLOCKPURGE(vp); 3383 vp->v_lockf = NULL; 3384 /* 3385 * Delete from old mount point vnode list. 3386 */ 3387 delmntque(vp); 3388 cache_purge(vp); 3389 /* 3390 * Done with purge, reset to the standard lock and invalidate 3391 * the vnode. 3392 */ 3393 VI_LOCK(vp); 3394 vp->v_vnlock = &vp->v_lock; 3395 vp->v_op = &dead_vnodeops; 3396 vp->v_tag = "none"; 3397 vp->v_type = VBAD; 3398 } 3399 3400 /* 3401 * Calculate the total number of references to a special device. 3402 */ 3403 int 3404 vcount(struct vnode *vp) 3405 { 3406 int count; 3407 3408 dev_lock(); 3409 count = vp->v_rdev->si_usecount; 3410 dev_unlock(); 3411 return (count); 3412 } 3413 3414 /* 3415 * Same as above, but using the struct cdev *as argument 3416 */ 3417 int 3418 count_dev(struct cdev *dev) 3419 { 3420 int count; 3421 3422 dev_lock(); 3423 count = dev->si_usecount; 3424 dev_unlock(); 3425 return(count); 3426 } 3427 3428 /* 3429 * Print out a description of a vnode. 3430 */ 3431 static char *typename[] = 3432 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3433 "VMARKER"}; 3434 3435 void 3436 vn_printf(struct vnode *vp, const char *fmt, ...) 3437 { 3438 va_list ap; 3439 char buf[256], buf2[16]; 3440 u_long flags; 3441 3442 va_start(ap, fmt); 3443 vprintf(fmt, ap); 3444 va_end(ap); 3445 printf("%p: ", (void *)vp); 3446 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3447 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 3448 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 3449 buf[0] = '\0'; 3450 buf[1] = '\0'; 3451 if (vp->v_vflag & VV_ROOT) 3452 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3453 if (vp->v_vflag & VV_ISTTY) 3454 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3455 if (vp->v_vflag & VV_NOSYNC) 3456 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3457 if (vp->v_vflag & VV_ETERNALDEV) 3458 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3459 if (vp->v_vflag & VV_CACHEDLABEL) 3460 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3461 if (vp->v_vflag & VV_TEXT) 3462 strlcat(buf, "|VV_TEXT", sizeof(buf)); 3463 if (vp->v_vflag & VV_COPYONWRITE) 3464 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3465 if (vp->v_vflag & VV_SYSTEM) 3466 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3467 if (vp->v_vflag & VV_PROCDEP) 3468 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3469 if (vp->v_vflag & VV_NOKNOTE) 3470 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3471 if (vp->v_vflag & VV_DELETED) 3472 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3473 if (vp->v_vflag & VV_MD) 3474 strlcat(buf, "|VV_MD", sizeof(buf)); 3475 if (vp->v_vflag & VV_FORCEINSMQ) 3476 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3477 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3478 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3479 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3480 if (flags != 0) { 3481 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3482 strlcat(buf, buf2, sizeof(buf)); 3483 } 3484 if (vp->v_iflag & VI_MOUNT) 3485 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3486 if (vp->v_iflag & VI_DOOMED) 3487 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 3488 if (vp->v_iflag & VI_FREE) 3489 strlcat(buf, "|VI_FREE", sizeof(buf)); 3490 if (vp->v_iflag & VI_ACTIVE) 3491 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3492 if (vp->v_iflag & VI_DOINGINACT) 3493 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3494 if (vp->v_iflag & VI_OWEINACT) 3495 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3496 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | 3497 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT); 3498 if (flags != 0) { 3499 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3500 strlcat(buf, buf2, sizeof(buf)); 3501 } 3502 printf(" flags (%s)\n", buf + 1); 3503 if (mtx_owned(VI_MTX(vp))) 3504 printf(" VI_LOCKed"); 3505 if (vp->v_object != NULL) 3506 printf(" v_object %p ref %d pages %d " 3507 "cleanbuf %d dirtybuf %d\n", 3508 vp->v_object, vp->v_object->ref_count, 3509 vp->v_object->resident_page_count, 3510 vp->v_bufobj.bo_clean.bv_cnt, 3511 vp->v_bufobj.bo_dirty.bv_cnt); 3512 printf(" "); 3513 lockmgr_printinfo(vp->v_vnlock); 3514 if (vp->v_data != NULL) 3515 VOP_PRINT(vp); 3516 } 3517 3518 #ifdef DDB 3519 /* 3520 * List all of the locked vnodes in the system. 3521 * Called when debugging the kernel. 3522 */ 3523 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3524 { 3525 struct mount *mp; 3526 struct vnode *vp; 3527 3528 /* 3529 * Note: because this is DDB, we can't obey the locking semantics 3530 * for these structures, which means we could catch an inconsistent 3531 * state and dereference a nasty pointer. Not much to be done 3532 * about that. 3533 */ 3534 db_printf("Locked vnodes\n"); 3535 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3536 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3537 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3538 vn_printf(vp, "vnode "); 3539 } 3540 } 3541 } 3542 3543 /* 3544 * Show details about the given vnode. 3545 */ 3546 DB_SHOW_COMMAND(vnode, db_show_vnode) 3547 { 3548 struct vnode *vp; 3549 3550 if (!have_addr) 3551 return; 3552 vp = (struct vnode *)addr; 3553 vn_printf(vp, "vnode "); 3554 } 3555 3556 /* 3557 * Show details about the given mount point. 3558 */ 3559 DB_SHOW_COMMAND(mount, db_show_mount) 3560 { 3561 struct mount *mp; 3562 struct vfsopt *opt; 3563 struct statfs *sp; 3564 struct vnode *vp; 3565 char buf[512]; 3566 uint64_t mflags; 3567 u_int flags; 3568 3569 if (!have_addr) { 3570 /* No address given, print short info about all mount points. */ 3571 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3572 db_printf("%p %s on %s (%s)\n", mp, 3573 mp->mnt_stat.f_mntfromname, 3574 mp->mnt_stat.f_mntonname, 3575 mp->mnt_stat.f_fstypename); 3576 if (db_pager_quit) 3577 break; 3578 } 3579 db_printf("\nMore info: show mount <addr>\n"); 3580 return; 3581 } 3582 3583 mp = (struct mount *)addr; 3584 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3585 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3586 3587 buf[0] = '\0'; 3588 mflags = mp->mnt_flag; 3589 #define MNT_FLAG(flag) do { \ 3590 if (mflags & (flag)) { \ 3591 if (buf[0] != '\0') \ 3592 strlcat(buf, ", ", sizeof(buf)); \ 3593 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3594 mflags &= ~(flag); \ 3595 } \ 3596 } while (0) 3597 MNT_FLAG(MNT_RDONLY); 3598 MNT_FLAG(MNT_SYNCHRONOUS); 3599 MNT_FLAG(MNT_NOEXEC); 3600 MNT_FLAG(MNT_NOSUID); 3601 MNT_FLAG(MNT_NFS4ACLS); 3602 MNT_FLAG(MNT_UNION); 3603 MNT_FLAG(MNT_ASYNC); 3604 MNT_FLAG(MNT_SUIDDIR); 3605 MNT_FLAG(MNT_SOFTDEP); 3606 MNT_FLAG(MNT_NOSYMFOLLOW); 3607 MNT_FLAG(MNT_GJOURNAL); 3608 MNT_FLAG(MNT_MULTILABEL); 3609 MNT_FLAG(MNT_ACLS); 3610 MNT_FLAG(MNT_NOATIME); 3611 MNT_FLAG(MNT_NOCLUSTERR); 3612 MNT_FLAG(MNT_NOCLUSTERW); 3613 MNT_FLAG(MNT_SUJ); 3614 MNT_FLAG(MNT_EXRDONLY); 3615 MNT_FLAG(MNT_EXPORTED); 3616 MNT_FLAG(MNT_DEFEXPORTED); 3617 MNT_FLAG(MNT_EXPORTANON); 3618 MNT_FLAG(MNT_EXKERB); 3619 MNT_FLAG(MNT_EXPUBLIC); 3620 MNT_FLAG(MNT_LOCAL); 3621 MNT_FLAG(MNT_QUOTA); 3622 MNT_FLAG(MNT_ROOTFS); 3623 MNT_FLAG(MNT_USER); 3624 MNT_FLAG(MNT_IGNORE); 3625 MNT_FLAG(MNT_UPDATE); 3626 MNT_FLAG(MNT_DELEXPORT); 3627 MNT_FLAG(MNT_RELOAD); 3628 MNT_FLAG(MNT_FORCE); 3629 MNT_FLAG(MNT_SNAPSHOT); 3630 MNT_FLAG(MNT_BYFSID); 3631 #undef MNT_FLAG 3632 if (mflags != 0) { 3633 if (buf[0] != '\0') 3634 strlcat(buf, ", ", sizeof(buf)); 3635 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3636 "0x%016jx", mflags); 3637 } 3638 db_printf(" mnt_flag = %s\n", buf); 3639 3640 buf[0] = '\0'; 3641 flags = mp->mnt_kern_flag; 3642 #define MNT_KERN_FLAG(flag) do { \ 3643 if (flags & (flag)) { \ 3644 if (buf[0] != '\0') \ 3645 strlcat(buf, ", ", sizeof(buf)); \ 3646 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3647 flags &= ~(flag); \ 3648 } \ 3649 } while (0) 3650 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3651 MNT_KERN_FLAG(MNTK_ASYNC); 3652 MNT_KERN_FLAG(MNTK_SOFTDEP); 3653 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 3654 MNT_KERN_FLAG(MNTK_DRAINING); 3655 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3656 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3657 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3658 MNT_KERN_FLAG(MNTK_NO_IOPF); 3659 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3660 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3661 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3662 MNT_KERN_FLAG(MNTK_MARKER); 3663 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3664 MNT_KERN_FLAG(MNTK_NOASYNC); 3665 MNT_KERN_FLAG(MNTK_UNMOUNT); 3666 MNT_KERN_FLAG(MNTK_MWAIT); 3667 MNT_KERN_FLAG(MNTK_SUSPEND); 3668 MNT_KERN_FLAG(MNTK_SUSPEND2); 3669 MNT_KERN_FLAG(MNTK_SUSPENDED); 3670 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3671 MNT_KERN_FLAG(MNTK_NOKNOTE); 3672 #undef MNT_KERN_FLAG 3673 if (flags != 0) { 3674 if (buf[0] != '\0') 3675 strlcat(buf, ", ", sizeof(buf)); 3676 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3677 "0x%08x", flags); 3678 } 3679 db_printf(" mnt_kern_flag = %s\n", buf); 3680 3681 db_printf(" mnt_opt = "); 3682 opt = TAILQ_FIRST(mp->mnt_opt); 3683 if (opt != NULL) { 3684 db_printf("%s", opt->name); 3685 opt = TAILQ_NEXT(opt, link); 3686 while (opt != NULL) { 3687 db_printf(", %s", opt->name); 3688 opt = TAILQ_NEXT(opt, link); 3689 } 3690 } 3691 db_printf("\n"); 3692 3693 sp = &mp->mnt_stat; 3694 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3695 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3696 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3697 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3698 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3699 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 3700 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 3701 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 3702 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 3703 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 3704 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 3705 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 3706 3707 db_printf(" mnt_cred = { uid=%u ruid=%u", 3708 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 3709 if (jailed(mp->mnt_cred)) 3710 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 3711 db_printf(" }\n"); 3712 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 3713 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 3714 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 3715 db_printf(" mnt_activevnodelistsize = %d\n", 3716 mp->mnt_activevnodelistsize); 3717 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 3718 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 3719 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 3720 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 3721 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); 3722 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 3723 db_printf(" mnt_secondary_accwrites = %d\n", 3724 mp->mnt_secondary_accwrites); 3725 db_printf(" mnt_gjprovider = %s\n", 3726 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 3727 3728 db_printf("\n\nList of active vnodes\n"); 3729 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 3730 if (vp->v_type != VMARKER) { 3731 vn_printf(vp, "vnode "); 3732 if (db_pager_quit) 3733 break; 3734 } 3735 } 3736 db_printf("\n\nList of inactive vnodes\n"); 3737 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3738 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 3739 vn_printf(vp, "vnode "); 3740 if (db_pager_quit) 3741 break; 3742 } 3743 } 3744 } 3745 #endif /* DDB */ 3746 3747 /* 3748 * Fill in a struct xvfsconf based on a struct vfsconf. 3749 */ 3750 static int 3751 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 3752 { 3753 struct xvfsconf xvfsp; 3754 3755 bzero(&xvfsp, sizeof(xvfsp)); 3756 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3757 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3758 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3759 xvfsp.vfc_flags = vfsp->vfc_flags; 3760 /* 3761 * These are unused in userland, we keep them 3762 * to not break binary compatibility. 3763 */ 3764 xvfsp.vfc_vfsops = NULL; 3765 xvfsp.vfc_next = NULL; 3766 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3767 } 3768 3769 #ifdef COMPAT_FREEBSD32 3770 struct xvfsconf32 { 3771 uint32_t vfc_vfsops; 3772 char vfc_name[MFSNAMELEN]; 3773 int32_t vfc_typenum; 3774 int32_t vfc_refcount; 3775 int32_t vfc_flags; 3776 uint32_t vfc_next; 3777 }; 3778 3779 static int 3780 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 3781 { 3782 struct xvfsconf32 xvfsp; 3783 3784 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3785 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3786 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3787 xvfsp.vfc_flags = vfsp->vfc_flags; 3788 xvfsp.vfc_vfsops = 0; 3789 xvfsp.vfc_next = 0; 3790 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3791 } 3792 #endif 3793 3794 /* 3795 * Top level filesystem related information gathering. 3796 */ 3797 static int 3798 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3799 { 3800 struct vfsconf *vfsp; 3801 int error; 3802 3803 error = 0; 3804 vfsconf_slock(); 3805 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3806 #ifdef COMPAT_FREEBSD32 3807 if (req->flags & SCTL_MASK32) 3808 error = vfsconf2x32(req, vfsp); 3809 else 3810 #endif 3811 error = vfsconf2x(req, vfsp); 3812 if (error) 3813 break; 3814 } 3815 vfsconf_sunlock(); 3816 return (error); 3817 } 3818 3819 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 3820 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 3821 "S,xvfsconf", "List of all configured filesystems"); 3822 3823 #ifndef BURN_BRIDGES 3824 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3825 3826 static int 3827 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3828 { 3829 int *name = (int *)arg1 - 1; /* XXX */ 3830 u_int namelen = arg2 + 1; /* XXX */ 3831 struct vfsconf *vfsp; 3832 3833 log(LOG_WARNING, "userland calling deprecated sysctl, " 3834 "please rebuild world\n"); 3835 3836 #if 1 || defined(COMPAT_PRELITE2) 3837 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3838 if (namelen == 1) 3839 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3840 #endif 3841 3842 switch (name[1]) { 3843 case VFS_MAXTYPENUM: 3844 if (namelen != 2) 3845 return (ENOTDIR); 3846 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3847 case VFS_CONF: 3848 if (namelen != 3) 3849 return (ENOTDIR); /* overloaded */ 3850 vfsconf_slock(); 3851 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3852 if (vfsp->vfc_typenum == name[2]) 3853 break; 3854 } 3855 vfsconf_sunlock(); 3856 if (vfsp == NULL) 3857 return (EOPNOTSUPP); 3858 #ifdef COMPAT_FREEBSD32 3859 if (req->flags & SCTL_MASK32) 3860 return (vfsconf2x32(req, vfsp)); 3861 else 3862 #endif 3863 return (vfsconf2x(req, vfsp)); 3864 } 3865 return (EOPNOTSUPP); 3866 } 3867 3868 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 3869 CTLFLAG_MPSAFE, vfs_sysctl, 3870 "Generic filesystem"); 3871 3872 #if 1 || defined(COMPAT_PRELITE2) 3873 3874 static int 3875 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3876 { 3877 int error; 3878 struct vfsconf *vfsp; 3879 struct ovfsconf ovfs; 3880 3881 vfsconf_slock(); 3882 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3883 bzero(&ovfs, sizeof(ovfs)); 3884 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3885 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3886 ovfs.vfc_index = vfsp->vfc_typenum; 3887 ovfs.vfc_refcount = vfsp->vfc_refcount; 3888 ovfs.vfc_flags = vfsp->vfc_flags; 3889 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3890 if (error != 0) { 3891 vfsconf_sunlock(); 3892 return (error); 3893 } 3894 } 3895 vfsconf_sunlock(); 3896 return (0); 3897 } 3898 3899 #endif /* 1 || COMPAT_PRELITE2 */ 3900 #endif /* !BURN_BRIDGES */ 3901 3902 #define KINFO_VNODESLOP 10 3903 #ifdef notyet 3904 /* 3905 * Dump vnode list (via sysctl). 3906 */ 3907 /* ARGSUSED */ 3908 static int 3909 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3910 { 3911 struct xvnode *xvn; 3912 struct mount *mp; 3913 struct vnode *vp; 3914 int error, len, n; 3915 3916 /* 3917 * Stale numvnodes access is not fatal here. 3918 */ 3919 req->lock = 0; 3920 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3921 if (!req->oldptr) 3922 /* Make an estimate */ 3923 return (SYSCTL_OUT(req, 0, len)); 3924 3925 error = sysctl_wire_old_buffer(req, 0); 3926 if (error != 0) 3927 return (error); 3928 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3929 n = 0; 3930 mtx_lock(&mountlist_mtx); 3931 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3932 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 3933 continue; 3934 MNT_ILOCK(mp); 3935 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3936 if (n == len) 3937 break; 3938 vref(vp); 3939 xvn[n].xv_size = sizeof *xvn; 3940 xvn[n].xv_vnode = vp; 3941 xvn[n].xv_id = 0; /* XXX compat */ 3942 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3943 XV_COPY(usecount); 3944 XV_COPY(writecount); 3945 XV_COPY(holdcnt); 3946 XV_COPY(mount); 3947 XV_COPY(numoutput); 3948 XV_COPY(type); 3949 #undef XV_COPY 3950 xvn[n].xv_flag = vp->v_vflag; 3951 3952 switch (vp->v_type) { 3953 case VREG: 3954 case VDIR: 3955 case VLNK: 3956 break; 3957 case VBLK: 3958 case VCHR: 3959 if (vp->v_rdev == NULL) { 3960 vrele(vp); 3961 continue; 3962 } 3963 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3964 break; 3965 case VSOCK: 3966 xvn[n].xv_socket = vp->v_socket; 3967 break; 3968 case VFIFO: 3969 xvn[n].xv_fifo = vp->v_fifoinfo; 3970 break; 3971 case VNON: 3972 case VBAD: 3973 default: 3974 /* shouldn't happen? */ 3975 vrele(vp); 3976 continue; 3977 } 3978 vrele(vp); 3979 ++n; 3980 } 3981 MNT_IUNLOCK(mp); 3982 mtx_lock(&mountlist_mtx); 3983 vfs_unbusy(mp); 3984 if (n == len) 3985 break; 3986 } 3987 mtx_unlock(&mountlist_mtx); 3988 3989 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3990 free(xvn, M_TEMP); 3991 return (error); 3992 } 3993 3994 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 3995 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 3996 ""); 3997 #endif 3998 3999 static void 4000 unmount_or_warn(struct mount *mp) 4001 { 4002 int error; 4003 4004 error = dounmount(mp, MNT_FORCE, curthread); 4005 if (error != 0) { 4006 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 4007 if (error == EBUSY) 4008 printf("BUSY)\n"); 4009 else 4010 printf("%d)\n", error); 4011 } 4012 } 4013 4014 /* 4015 * Unmount all filesystems. The list is traversed in reverse order 4016 * of mounting to avoid dependencies. 4017 */ 4018 void 4019 vfs_unmountall(void) 4020 { 4021 struct mount *mp, *tmp; 4022 4023 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 4024 4025 /* 4026 * Since this only runs when rebooting, it is not interlocked. 4027 */ 4028 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 4029 vfs_ref(mp); 4030 4031 /* 4032 * Forcibly unmounting "/dev" before "/" would prevent clean 4033 * unmount of the latter. 4034 */ 4035 if (mp == rootdevmp) 4036 continue; 4037 4038 unmount_or_warn(mp); 4039 } 4040 4041 if (rootdevmp != NULL) 4042 unmount_or_warn(rootdevmp); 4043 } 4044 4045 /* 4046 * perform msync on all vnodes under a mount point 4047 * the mount point must be locked. 4048 */ 4049 void 4050 vfs_msync(struct mount *mp, int flags) 4051 { 4052 struct vnode *vp, *mvp; 4053 struct vm_object *obj; 4054 4055 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 4056 4057 vnlru_return_batch(mp); 4058 4059 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 4060 obj = vp->v_object; 4061 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 4062 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 4063 if (!vget(vp, 4064 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 4065 curthread)) { 4066 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 4067 vput(vp); 4068 continue; 4069 } 4070 4071 obj = vp->v_object; 4072 if (obj != NULL) { 4073 VM_OBJECT_WLOCK(obj); 4074 vm_object_page_clean(obj, 0, 0, 4075 flags == MNT_WAIT ? 4076 OBJPC_SYNC : OBJPC_NOSYNC); 4077 VM_OBJECT_WUNLOCK(obj); 4078 } 4079 vput(vp); 4080 } 4081 } else 4082 VI_UNLOCK(vp); 4083 } 4084 } 4085 4086 static void 4087 destroy_vpollinfo_free(struct vpollinfo *vi) 4088 { 4089 4090 knlist_destroy(&vi->vpi_selinfo.si_note); 4091 mtx_destroy(&vi->vpi_lock); 4092 uma_zfree(vnodepoll_zone, vi); 4093 } 4094 4095 static void 4096 destroy_vpollinfo(struct vpollinfo *vi) 4097 { 4098 4099 knlist_clear(&vi->vpi_selinfo.si_note, 1); 4100 seldrain(&vi->vpi_selinfo); 4101 destroy_vpollinfo_free(vi); 4102 } 4103 4104 /* 4105 * Initialize per-vnode helper structure to hold poll-related state. 4106 */ 4107 void 4108 v_addpollinfo(struct vnode *vp) 4109 { 4110 struct vpollinfo *vi; 4111 4112 if (vp->v_pollinfo != NULL) 4113 return; 4114 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 4115 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 4116 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 4117 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 4118 VI_LOCK(vp); 4119 if (vp->v_pollinfo != NULL) { 4120 VI_UNLOCK(vp); 4121 destroy_vpollinfo_free(vi); 4122 return; 4123 } 4124 vp->v_pollinfo = vi; 4125 VI_UNLOCK(vp); 4126 } 4127 4128 /* 4129 * Record a process's interest in events which might happen to 4130 * a vnode. Because poll uses the historic select-style interface 4131 * internally, this routine serves as both the ``check for any 4132 * pending events'' and the ``record my interest in future events'' 4133 * functions. (These are done together, while the lock is held, 4134 * to avoid race conditions.) 4135 */ 4136 int 4137 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 4138 { 4139 4140 v_addpollinfo(vp); 4141 mtx_lock(&vp->v_pollinfo->vpi_lock); 4142 if (vp->v_pollinfo->vpi_revents & events) { 4143 /* 4144 * This leaves events we are not interested 4145 * in available for the other process which 4146 * which presumably had requested them 4147 * (otherwise they would never have been 4148 * recorded). 4149 */ 4150 events &= vp->v_pollinfo->vpi_revents; 4151 vp->v_pollinfo->vpi_revents &= ~events; 4152 4153 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4154 return (events); 4155 } 4156 vp->v_pollinfo->vpi_events |= events; 4157 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 4158 mtx_unlock(&vp->v_pollinfo->vpi_lock); 4159 return (0); 4160 } 4161 4162 /* 4163 * Routine to create and manage a filesystem syncer vnode. 4164 */ 4165 #define sync_close ((int (*)(struct vop_close_args *))nullop) 4166 static int sync_fsync(struct vop_fsync_args *); 4167 static int sync_inactive(struct vop_inactive_args *); 4168 static int sync_reclaim(struct vop_reclaim_args *); 4169 4170 static struct vop_vector sync_vnodeops = { 4171 .vop_bypass = VOP_EOPNOTSUPP, 4172 .vop_close = sync_close, /* close */ 4173 .vop_fsync = sync_fsync, /* fsync */ 4174 .vop_inactive = sync_inactive, /* inactive */ 4175 .vop_reclaim = sync_reclaim, /* reclaim */ 4176 .vop_lock1 = vop_stdlock, /* lock */ 4177 .vop_unlock = vop_stdunlock, /* unlock */ 4178 .vop_islocked = vop_stdislocked, /* islocked */ 4179 }; 4180 4181 /* 4182 * Create a new filesystem syncer vnode for the specified mount point. 4183 */ 4184 void 4185 vfs_allocate_syncvnode(struct mount *mp) 4186 { 4187 struct vnode *vp; 4188 struct bufobj *bo; 4189 static long start, incr, next; 4190 int error; 4191 4192 /* Allocate a new vnode */ 4193 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 4194 if (error != 0) 4195 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 4196 vp->v_type = VNON; 4197 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4198 vp->v_vflag |= VV_FORCEINSMQ; 4199 error = insmntque(vp, mp); 4200 if (error != 0) 4201 panic("vfs_allocate_syncvnode: insmntque() failed"); 4202 vp->v_vflag &= ~VV_FORCEINSMQ; 4203 VOP_UNLOCK(vp, 0); 4204 /* 4205 * Place the vnode onto the syncer worklist. We attempt to 4206 * scatter them about on the list so that they will go off 4207 * at evenly distributed times even if all the filesystems 4208 * are mounted at once. 4209 */ 4210 next += incr; 4211 if (next == 0 || next > syncer_maxdelay) { 4212 start /= 2; 4213 incr /= 2; 4214 if (start == 0) { 4215 start = syncer_maxdelay / 2; 4216 incr = syncer_maxdelay; 4217 } 4218 next = start; 4219 } 4220 bo = &vp->v_bufobj; 4221 BO_LOCK(bo); 4222 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 4223 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 4224 mtx_lock(&sync_mtx); 4225 sync_vnode_count++; 4226 if (mp->mnt_syncer == NULL) { 4227 mp->mnt_syncer = vp; 4228 vp = NULL; 4229 } 4230 mtx_unlock(&sync_mtx); 4231 BO_UNLOCK(bo); 4232 if (vp != NULL) { 4233 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4234 vgone(vp); 4235 vput(vp); 4236 } 4237 } 4238 4239 void 4240 vfs_deallocate_syncvnode(struct mount *mp) 4241 { 4242 struct vnode *vp; 4243 4244 mtx_lock(&sync_mtx); 4245 vp = mp->mnt_syncer; 4246 if (vp != NULL) 4247 mp->mnt_syncer = NULL; 4248 mtx_unlock(&sync_mtx); 4249 if (vp != NULL) 4250 vrele(vp); 4251 } 4252 4253 /* 4254 * Do a lazy sync of the filesystem. 4255 */ 4256 static int 4257 sync_fsync(struct vop_fsync_args *ap) 4258 { 4259 struct vnode *syncvp = ap->a_vp; 4260 struct mount *mp = syncvp->v_mount; 4261 int error, save; 4262 struct bufobj *bo; 4263 4264 /* 4265 * We only need to do something if this is a lazy evaluation. 4266 */ 4267 if (ap->a_waitfor != MNT_LAZY) 4268 return (0); 4269 4270 /* 4271 * Move ourselves to the back of the sync list. 4272 */ 4273 bo = &syncvp->v_bufobj; 4274 BO_LOCK(bo); 4275 vn_syncer_add_to_worklist(bo, syncdelay); 4276 BO_UNLOCK(bo); 4277 4278 /* 4279 * Walk the list of vnodes pushing all that are dirty and 4280 * not already on the sync list. 4281 */ 4282 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4283 return (0); 4284 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4285 vfs_unbusy(mp); 4286 return (0); 4287 } 4288 save = curthread_pflags_set(TDP_SYNCIO); 4289 vfs_msync(mp, MNT_NOWAIT); 4290 error = VFS_SYNC(mp, MNT_LAZY); 4291 curthread_pflags_restore(save); 4292 vn_finished_write(mp); 4293 vfs_unbusy(mp); 4294 return (error); 4295 } 4296 4297 /* 4298 * The syncer vnode is no referenced. 4299 */ 4300 static int 4301 sync_inactive(struct vop_inactive_args *ap) 4302 { 4303 4304 vgone(ap->a_vp); 4305 return (0); 4306 } 4307 4308 /* 4309 * The syncer vnode is no longer needed and is being decommissioned. 4310 * 4311 * Modifications to the worklist must be protected by sync_mtx. 4312 */ 4313 static int 4314 sync_reclaim(struct vop_reclaim_args *ap) 4315 { 4316 struct vnode *vp = ap->a_vp; 4317 struct bufobj *bo; 4318 4319 bo = &vp->v_bufobj; 4320 BO_LOCK(bo); 4321 mtx_lock(&sync_mtx); 4322 if (vp->v_mount->mnt_syncer == vp) 4323 vp->v_mount->mnt_syncer = NULL; 4324 if (bo->bo_flag & BO_ONWORKLST) { 4325 LIST_REMOVE(bo, bo_synclist); 4326 syncer_worklist_len--; 4327 sync_vnode_count--; 4328 bo->bo_flag &= ~BO_ONWORKLST; 4329 } 4330 mtx_unlock(&sync_mtx); 4331 BO_UNLOCK(bo); 4332 4333 return (0); 4334 } 4335 4336 /* 4337 * Check if vnode represents a disk device 4338 */ 4339 int 4340 vn_isdisk(struct vnode *vp, int *errp) 4341 { 4342 int error; 4343 4344 if (vp->v_type != VCHR) { 4345 error = ENOTBLK; 4346 goto out; 4347 } 4348 error = 0; 4349 dev_lock(); 4350 if (vp->v_rdev == NULL) 4351 error = ENXIO; 4352 else if (vp->v_rdev->si_devsw == NULL) 4353 error = ENXIO; 4354 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4355 error = ENOTBLK; 4356 dev_unlock(); 4357 out: 4358 if (errp != NULL) 4359 *errp = error; 4360 return (error == 0); 4361 } 4362 4363 /* 4364 * Common filesystem object access control check routine. Accepts a 4365 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4366 * and optional call-by-reference privused argument allowing vaccess() 4367 * to indicate to the caller whether privilege was used to satisfy the 4368 * request (obsoleted). Returns 0 on success, or an errno on failure. 4369 */ 4370 int 4371 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4372 accmode_t accmode, struct ucred *cred, int *privused) 4373 { 4374 accmode_t dac_granted; 4375 accmode_t priv_granted; 4376 4377 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4378 ("invalid bit in accmode")); 4379 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4380 ("VAPPEND without VWRITE")); 4381 4382 /* 4383 * Look for a normal, non-privileged way to access the file/directory 4384 * as requested. If it exists, go with that. 4385 */ 4386 4387 if (privused != NULL) 4388 *privused = 0; 4389 4390 dac_granted = 0; 4391 4392 /* Check the owner. */ 4393 if (cred->cr_uid == file_uid) { 4394 dac_granted |= VADMIN; 4395 if (file_mode & S_IXUSR) 4396 dac_granted |= VEXEC; 4397 if (file_mode & S_IRUSR) 4398 dac_granted |= VREAD; 4399 if (file_mode & S_IWUSR) 4400 dac_granted |= (VWRITE | VAPPEND); 4401 4402 if ((accmode & dac_granted) == accmode) 4403 return (0); 4404 4405 goto privcheck; 4406 } 4407 4408 /* Otherwise, check the groups (first match) */ 4409 if (groupmember(file_gid, cred)) { 4410 if (file_mode & S_IXGRP) 4411 dac_granted |= VEXEC; 4412 if (file_mode & S_IRGRP) 4413 dac_granted |= VREAD; 4414 if (file_mode & S_IWGRP) 4415 dac_granted |= (VWRITE | VAPPEND); 4416 4417 if ((accmode & dac_granted) == accmode) 4418 return (0); 4419 4420 goto privcheck; 4421 } 4422 4423 /* Otherwise, check everyone else. */ 4424 if (file_mode & S_IXOTH) 4425 dac_granted |= VEXEC; 4426 if (file_mode & S_IROTH) 4427 dac_granted |= VREAD; 4428 if (file_mode & S_IWOTH) 4429 dac_granted |= (VWRITE | VAPPEND); 4430 if ((accmode & dac_granted) == accmode) 4431 return (0); 4432 4433 privcheck: 4434 /* 4435 * Build a privilege mask to determine if the set of privileges 4436 * satisfies the requirements when combined with the granted mask 4437 * from above. For each privilege, if the privilege is required, 4438 * bitwise or the request type onto the priv_granted mask. 4439 */ 4440 priv_granted = 0; 4441 4442 if (type == VDIR) { 4443 /* 4444 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4445 * requests, instead of PRIV_VFS_EXEC. 4446 */ 4447 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4448 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 4449 priv_granted |= VEXEC; 4450 } else { 4451 /* 4452 * Ensure that at least one execute bit is on. Otherwise, 4453 * a privileged user will always succeed, and we don't want 4454 * this to happen unless the file really is executable. 4455 */ 4456 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4457 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4458 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 4459 priv_granted |= VEXEC; 4460 } 4461 4462 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4463 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 4464 priv_granted |= VREAD; 4465 4466 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4467 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 4468 priv_granted |= (VWRITE | VAPPEND); 4469 4470 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4471 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 4472 priv_granted |= VADMIN; 4473 4474 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4475 /* XXX audit: privilege used */ 4476 if (privused != NULL) 4477 *privused = 1; 4478 return (0); 4479 } 4480 4481 return ((accmode & VADMIN) ? EPERM : EACCES); 4482 } 4483 4484 /* 4485 * Credential check based on process requesting service, and per-attribute 4486 * permissions. 4487 */ 4488 int 4489 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4490 struct thread *td, accmode_t accmode) 4491 { 4492 4493 /* 4494 * Kernel-invoked always succeeds. 4495 */ 4496 if (cred == NOCRED) 4497 return (0); 4498 4499 /* 4500 * Do not allow privileged processes in jail to directly manipulate 4501 * system attributes. 4502 */ 4503 switch (attrnamespace) { 4504 case EXTATTR_NAMESPACE_SYSTEM: 4505 /* Potentially should be: return (EPERM); */ 4506 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 4507 case EXTATTR_NAMESPACE_USER: 4508 return (VOP_ACCESS(vp, accmode, cred, td)); 4509 default: 4510 return (EPERM); 4511 } 4512 } 4513 4514 #ifdef DEBUG_VFS_LOCKS 4515 /* 4516 * This only exists to suppress warnings from unlocked specfs accesses. It is 4517 * no longer ok to have an unlocked VFS. 4518 */ 4519 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4520 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4521 4522 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4523 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4524 "Drop into debugger on lock violation"); 4525 4526 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4527 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4528 0, "Check for interlock across VOPs"); 4529 4530 int vfs_badlock_print = 1; /* Print lock violations. */ 4531 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4532 0, "Print lock violations"); 4533 4534 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ 4535 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, 4536 0, "Print vnode details on lock violations"); 4537 4538 #ifdef KDB 4539 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4540 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4541 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4542 #endif 4543 4544 static void 4545 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4546 { 4547 4548 #ifdef KDB 4549 if (vfs_badlock_backtrace) 4550 kdb_backtrace(); 4551 #endif 4552 if (vfs_badlock_vnode) 4553 vn_printf(vp, "vnode "); 4554 if (vfs_badlock_print) 4555 printf("%s: %p %s\n", str, (void *)vp, msg); 4556 if (vfs_badlock_ddb) 4557 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4558 } 4559 4560 void 4561 assert_vi_locked(struct vnode *vp, const char *str) 4562 { 4563 4564 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4565 vfs_badlock("interlock is not locked but should be", str, vp); 4566 } 4567 4568 void 4569 assert_vi_unlocked(struct vnode *vp, const char *str) 4570 { 4571 4572 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4573 vfs_badlock("interlock is locked but should not be", str, vp); 4574 } 4575 4576 void 4577 assert_vop_locked(struct vnode *vp, const char *str) 4578 { 4579 int locked; 4580 4581 if (!IGNORE_LOCK(vp)) { 4582 locked = VOP_ISLOCKED(vp); 4583 if (locked == 0 || locked == LK_EXCLOTHER) 4584 vfs_badlock("is not locked but should be", str, vp); 4585 } 4586 } 4587 4588 void 4589 assert_vop_unlocked(struct vnode *vp, const char *str) 4590 { 4591 4592 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4593 vfs_badlock("is locked but should not be", str, vp); 4594 } 4595 4596 void 4597 assert_vop_elocked(struct vnode *vp, const char *str) 4598 { 4599 4600 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4601 vfs_badlock("is not exclusive locked but should be", str, vp); 4602 } 4603 #endif /* DEBUG_VFS_LOCKS */ 4604 4605 void 4606 vop_rename_fail(struct vop_rename_args *ap) 4607 { 4608 4609 if (ap->a_tvp != NULL) 4610 vput(ap->a_tvp); 4611 if (ap->a_tdvp == ap->a_tvp) 4612 vrele(ap->a_tdvp); 4613 else 4614 vput(ap->a_tdvp); 4615 vrele(ap->a_fdvp); 4616 vrele(ap->a_fvp); 4617 } 4618 4619 void 4620 vop_rename_pre(void *ap) 4621 { 4622 struct vop_rename_args *a = ap; 4623 4624 #ifdef DEBUG_VFS_LOCKS 4625 if (a->a_tvp) 4626 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4627 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4628 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4629 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4630 4631 /* Check the source (from). */ 4632 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4633 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4634 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4635 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4636 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4637 4638 /* Check the target. */ 4639 if (a->a_tvp) 4640 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4641 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4642 #endif 4643 if (a->a_tdvp != a->a_fdvp) 4644 vhold(a->a_fdvp); 4645 if (a->a_tvp != a->a_fvp) 4646 vhold(a->a_fvp); 4647 vhold(a->a_tdvp); 4648 if (a->a_tvp) 4649 vhold(a->a_tvp); 4650 } 4651 4652 #ifdef DEBUG_VFS_LOCKS 4653 void 4654 vop_strategy_pre(void *ap) 4655 { 4656 struct vop_strategy_args *a; 4657 struct buf *bp; 4658 4659 a = ap; 4660 bp = a->a_bp; 4661 4662 /* 4663 * Cluster ops lock their component buffers but not the IO container. 4664 */ 4665 if ((bp->b_flags & B_CLUSTER) != 0) 4666 return; 4667 4668 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4669 if (vfs_badlock_print) 4670 printf( 4671 "VOP_STRATEGY: bp is not locked but should be\n"); 4672 if (vfs_badlock_ddb) 4673 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4674 } 4675 } 4676 4677 void 4678 vop_lock_pre(void *ap) 4679 { 4680 struct vop_lock1_args *a = ap; 4681 4682 if ((a->a_flags & LK_INTERLOCK) == 0) 4683 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4684 else 4685 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 4686 } 4687 4688 void 4689 vop_lock_post(void *ap, int rc) 4690 { 4691 struct vop_lock1_args *a = ap; 4692 4693 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4694 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 4695 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 4696 } 4697 4698 void 4699 vop_unlock_pre(void *ap) 4700 { 4701 struct vop_unlock_args *a = ap; 4702 4703 if (a->a_flags & LK_INTERLOCK) 4704 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4705 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4706 } 4707 4708 void 4709 vop_unlock_post(void *ap, int rc) 4710 { 4711 struct vop_unlock_args *a = ap; 4712 4713 if (a->a_flags & LK_INTERLOCK) 4714 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4715 } 4716 #endif 4717 4718 void 4719 vop_create_post(void *ap, int rc) 4720 { 4721 struct vop_create_args *a = ap; 4722 4723 if (!rc) 4724 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4725 } 4726 4727 void 4728 vop_deleteextattr_post(void *ap, int rc) 4729 { 4730 struct vop_deleteextattr_args *a = ap; 4731 4732 if (!rc) 4733 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4734 } 4735 4736 void 4737 vop_link_post(void *ap, int rc) 4738 { 4739 struct vop_link_args *a = ap; 4740 4741 if (!rc) { 4742 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4743 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4744 } 4745 } 4746 4747 void 4748 vop_mkdir_post(void *ap, int rc) 4749 { 4750 struct vop_mkdir_args *a = ap; 4751 4752 if (!rc) 4753 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4754 } 4755 4756 void 4757 vop_mknod_post(void *ap, int rc) 4758 { 4759 struct vop_mknod_args *a = ap; 4760 4761 if (!rc) 4762 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4763 } 4764 4765 void 4766 vop_reclaim_post(void *ap, int rc) 4767 { 4768 struct vop_reclaim_args *a = ap; 4769 4770 if (!rc) 4771 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 4772 } 4773 4774 void 4775 vop_remove_post(void *ap, int rc) 4776 { 4777 struct vop_remove_args *a = ap; 4778 4779 if (!rc) { 4780 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4781 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4782 } 4783 } 4784 4785 void 4786 vop_rename_post(void *ap, int rc) 4787 { 4788 struct vop_rename_args *a = ap; 4789 long hint; 4790 4791 if (!rc) { 4792 hint = NOTE_WRITE; 4793 if (a->a_fdvp == a->a_tdvp) { 4794 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) 4795 hint |= NOTE_LINK; 4796 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4797 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4798 } else { 4799 hint |= NOTE_EXTEND; 4800 if (a->a_fvp->v_type == VDIR) 4801 hint |= NOTE_LINK; 4802 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); 4803 4804 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && 4805 a->a_tvp->v_type == VDIR) 4806 hint &= ~NOTE_LINK; 4807 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); 4808 } 4809 4810 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4811 if (a->a_tvp) 4812 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4813 } 4814 if (a->a_tdvp != a->a_fdvp) 4815 vdrop(a->a_fdvp); 4816 if (a->a_tvp != a->a_fvp) 4817 vdrop(a->a_fvp); 4818 vdrop(a->a_tdvp); 4819 if (a->a_tvp) 4820 vdrop(a->a_tvp); 4821 } 4822 4823 void 4824 vop_rmdir_post(void *ap, int rc) 4825 { 4826 struct vop_rmdir_args *a = ap; 4827 4828 if (!rc) { 4829 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4830 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4831 } 4832 } 4833 4834 void 4835 vop_setattr_post(void *ap, int rc) 4836 { 4837 struct vop_setattr_args *a = ap; 4838 4839 if (!rc) 4840 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4841 } 4842 4843 void 4844 vop_setextattr_post(void *ap, int rc) 4845 { 4846 struct vop_setextattr_args *a = ap; 4847 4848 if (!rc) 4849 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4850 } 4851 4852 void 4853 vop_symlink_post(void *ap, int rc) 4854 { 4855 struct vop_symlink_args *a = ap; 4856 4857 if (!rc) 4858 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4859 } 4860 4861 void 4862 vop_open_post(void *ap, int rc) 4863 { 4864 struct vop_open_args *a = ap; 4865 4866 if (!rc) 4867 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); 4868 } 4869 4870 void 4871 vop_close_post(void *ap, int rc) 4872 { 4873 struct vop_close_args *a = ap; 4874 4875 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ 4876 (a->a_vp->v_iflag & VI_DOOMED) == 0)) { 4877 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? 4878 NOTE_CLOSE_WRITE : NOTE_CLOSE); 4879 } 4880 } 4881 4882 void 4883 vop_read_post(void *ap, int rc) 4884 { 4885 struct vop_read_args *a = ap; 4886 4887 if (!rc) 4888 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4889 } 4890 4891 void 4892 vop_readdir_post(void *ap, int rc) 4893 { 4894 struct vop_readdir_args *a = ap; 4895 4896 if (!rc) 4897 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); 4898 } 4899 4900 static struct knlist fs_knlist; 4901 4902 static void 4903 vfs_event_init(void *arg) 4904 { 4905 knlist_init_mtx(&fs_knlist, NULL); 4906 } 4907 /* XXX - correct order? */ 4908 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 4909 4910 void 4911 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 4912 { 4913 4914 KNOTE_UNLOCKED(&fs_knlist, event); 4915 } 4916 4917 static int filt_fsattach(struct knote *kn); 4918 static void filt_fsdetach(struct knote *kn); 4919 static int filt_fsevent(struct knote *kn, long hint); 4920 4921 struct filterops fs_filtops = { 4922 .f_isfd = 0, 4923 .f_attach = filt_fsattach, 4924 .f_detach = filt_fsdetach, 4925 .f_event = filt_fsevent 4926 }; 4927 4928 static int 4929 filt_fsattach(struct knote *kn) 4930 { 4931 4932 kn->kn_flags |= EV_CLEAR; 4933 knlist_add(&fs_knlist, kn, 0); 4934 return (0); 4935 } 4936 4937 static void 4938 filt_fsdetach(struct knote *kn) 4939 { 4940 4941 knlist_remove(&fs_knlist, kn, 0); 4942 } 4943 4944 static int 4945 filt_fsevent(struct knote *kn, long hint) 4946 { 4947 4948 kn->kn_fflags |= hint; 4949 return (kn->kn_fflags != 0); 4950 } 4951 4952 static int 4953 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 4954 { 4955 struct vfsidctl vc; 4956 int error; 4957 struct mount *mp; 4958 4959 error = SYSCTL_IN(req, &vc, sizeof(vc)); 4960 if (error) 4961 return (error); 4962 if (vc.vc_vers != VFS_CTL_VERS1) 4963 return (EINVAL); 4964 mp = vfs_getvfs(&vc.vc_fsid); 4965 if (mp == NULL) 4966 return (ENOENT); 4967 /* ensure that a specific sysctl goes to the right filesystem. */ 4968 if (strcmp(vc.vc_fstypename, "*") != 0 && 4969 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 4970 vfs_rel(mp); 4971 return (EINVAL); 4972 } 4973 VCTLTOREQ(&vc, req); 4974 error = VFS_SYSCTL(mp, vc.vc_op, req); 4975 vfs_rel(mp); 4976 return (error); 4977 } 4978 4979 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 4980 NULL, 0, sysctl_vfs_ctl, "", 4981 "Sysctl by fsid"); 4982 4983 /* 4984 * Function to initialize a va_filerev field sensibly. 4985 * XXX: Wouldn't a random number make a lot more sense ?? 4986 */ 4987 u_quad_t 4988 init_va_filerev(void) 4989 { 4990 struct bintime bt; 4991 4992 getbinuptime(&bt); 4993 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 4994 } 4995 4996 static int filt_vfsread(struct knote *kn, long hint); 4997 static int filt_vfswrite(struct knote *kn, long hint); 4998 static int filt_vfsvnode(struct knote *kn, long hint); 4999 static void filt_vfsdetach(struct knote *kn); 5000 static struct filterops vfsread_filtops = { 5001 .f_isfd = 1, 5002 .f_detach = filt_vfsdetach, 5003 .f_event = filt_vfsread 5004 }; 5005 static struct filterops vfswrite_filtops = { 5006 .f_isfd = 1, 5007 .f_detach = filt_vfsdetach, 5008 .f_event = filt_vfswrite 5009 }; 5010 static struct filterops vfsvnode_filtops = { 5011 .f_isfd = 1, 5012 .f_detach = filt_vfsdetach, 5013 .f_event = filt_vfsvnode 5014 }; 5015 5016 static void 5017 vfs_knllock(void *arg) 5018 { 5019 struct vnode *vp = arg; 5020 5021 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 5022 } 5023 5024 static void 5025 vfs_knlunlock(void *arg) 5026 { 5027 struct vnode *vp = arg; 5028 5029 VOP_UNLOCK(vp, 0); 5030 } 5031 5032 static void 5033 vfs_knl_assert_locked(void *arg) 5034 { 5035 #ifdef DEBUG_VFS_LOCKS 5036 struct vnode *vp = arg; 5037 5038 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 5039 #endif 5040 } 5041 5042 static void 5043 vfs_knl_assert_unlocked(void *arg) 5044 { 5045 #ifdef DEBUG_VFS_LOCKS 5046 struct vnode *vp = arg; 5047 5048 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 5049 #endif 5050 } 5051 5052 int 5053 vfs_kqfilter(struct vop_kqfilter_args *ap) 5054 { 5055 struct vnode *vp = ap->a_vp; 5056 struct knote *kn = ap->a_kn; 5057 struct knlist *knl; 5058 5059 switch (kn->kn_filter) { 5060 case EVFILT_READ: 5061 kn->kn_fop = &vfsread_filtops; 5062 break; 5063 case EVFILT_WRITE: 5064 kn->kn_fop = &vfswrite_filtops; 5065 break; 5066 case EVFILT_VNODE: 5067 kn->kn_fop = &vfsvnode_filtops; 5068 break; 5069 default: 5070 return (EINVAL); 5071 } 5072 5073 kn->kn_hook = (caddr_t)vp; 5074 5075 v_addpollinfo(vp); 5076 if (vp->v_pollinfo == NULL) 5077 return (ENOMEM); 5078 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 5079 vhold(vp); 5080 knlist_add(knl, kn, 0); 5081 5082 return (0); 5083 } 5084 5085 /* 5086 * Detach knote from vnode 5087 */ 5088 static void 5089 filt_vfsdetach(struct knote *kn) 5090 { 5091 struct vnode *vp = (struct vnode *)kn->kn_hook; 5092 5093 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 5094 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 5095 vdrop(vp); 5096 } 5097 5098 /*ARGSUSED*/ 5099 static int 5100 filt_vfsread(struct knote *kn, long hint) 5101 { 5102 struct vnode *vp = (struct vnode *)kn->kn_hook; 5103 struct vattr va; 5104 int res; 5105 5106 /* 5107 * filesystem is gone, so set the EOF flag and schedule 5108 * the knote for deletion. 5109 */ 5110 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5111 VI_LOCK(vp); 5112 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5113 VI_UNLOCK(vp); 5114 return (1); 5115 } 5116 5117 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 5118 return (0); 5119 5120 VI_LOCK(vp); 5121 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 5122 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 5123 VI_UNLOCK(vp); 5124 return (res); 5125 } 5126 5127 /*ARGSUSED*/ 5128 static int 5129 filt_vfswrite(struct knote *kn, long hint) 5130 { 5131 struct vnode *vp = (struct vnode *)kn->kn_hook; 5132 5133 VI_LOCK(vp); 5134 5135 /* 5136 * filesystem is gone, so set the EOF flag and schedule 5137 * the knote for deletion. 5138 */ 5139 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 5140 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 5141 5142 kn->kn_data = 0; 5143 VI_UNLOCK(vp); 5144 return (1); 5145 } 5146 5147 static int 5148 filt_vfsvnode(struct knote *kn, long hint) 5149 { 5150 struct vnode *vp = (struct vnode *)kn->kn_hook; 5151 int res; 5152 5153 VI_LOCK(vp); 5154 if (kn->kn_sfflags & hint) 5155 kn->kn_fflags |= hint; 5156 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 5157 kn->kn_flags |= EV_EOF; 5158 VI_UNLOCK(vp); 5159 return (1); 5160 } 5161 res = (kn->kn_fflags != 0); 5162 VI_UNLOCK(vp); 5163 return (res); 5164 } 5165 5166 int 5167 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 5168 { 5169 int error; 5170 5171 if (dp->d_reclen > ap->a_uio->uio_resid) 5172 return (ENAMETOOLONG); 5173 error = uiomove(dp, dp->d_reclen, ap->a_uio); 5174 if (error) { 5175 if (ap->a_ncookies != NULL) { 5176 if (ap->a_cookies != NULL) 5177 free(ap->a_cookies, M_TEMP); 5178 ap->a_cookies = NULL; 5179 *ap->a_ncookies = 0; 5180 } 5181 return (error); 5182 } 5183 if (ap->a_ncookies == NULL) 5184 return (0); 5185 5186 KASSERT(ap->a_cookies, 5187 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 5188 5189 *ap->a_cookies = realloc(*ap->a_cookies, 5190 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 5191 (*ap->a_cookies)[*ap->a_ncookies] = off; 5192 *ap->a_ncookies += 1; 5193 return (0); 5194 } 5195 5196 /* 5197 * Mark for update the access time of the file if the filesystem 5198 * supports VOP_MARKATIME. This functionality is used by execve and 5199 * mmap, so we want to avoid the I/O implied by directly setting 5200 * va_atime for the sake of efficiency. 5201 */ 5202 void 5203 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 5204 { 5205 struct mount *mp; 5206 5207 mp = vp->v_mount; 5208 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 5209 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 5210 (void)VOP_MARKATIME(vp); 5211 } 5212 5213 /* 5214 * The purpose of this routine is to remove granularity from accmode_t, 5215 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 5216 * VADMIN and VAPPEND. 5217 * 5218 * If it returns 0, the caller is supposed to continue with the usual 5219 * access checks using 'accmode' as modified by this routine. If it 5220 * returns nonzero value, the caller is supposed to return that value 5221 * as errno. 5222 * 5223 * Note that after this routine runs, accmode may be zero. 5224 */ 5225 int 5226 vfs_unixify_accmode(accmode_t *accmode) 5227 { 5228 /* 5229 * There is no way to specify explicit "deny" rule using 5230 * file mode or POSIX.1e ACLs. 5231 */ 5232 if (*accmode & VEXPLICIT_DENY) { 5233 *accmode = 0; 5234 return (0); 5235 } 5236 5237 /* 5238 * None of these can be translated into usual access bits. 5239 * Also, the common case for NFSv4 ACLs is to not contain 5240 * either of these bits. Caller should check for VWRITE 5241 * on the containing directory instead. 5242 */ 5243 if (*accmode & (VDELETE_CHILD | VDELETE)) 5244 return (EPERM); 5245 5246 if (*accmode & VADMIN_PERMS) { 5247 *accmode &= ~VADMIN_PERMS; 5248 *accmode |= VADMIN; 5249 } 5250 5251 /* 5252 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 5253 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 5254 */ 5255 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 5256 5257 return (0); 5258 } 5259 5260 /* 5261 * These are helper functions for filesystems to traverse all 5262 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 5263 * 5264 * This interface replaces MNT_VNODE_FOREACH. 5265 */ 5266 5267 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 5268 5269 struct vnode * 5270 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5271 { 5272 struct vnode *vp; 5273 5274 if (should_yield()) 5275 kern_yield(PRI_USER); 5276 MNT_ILOCK(mp); 5277 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5278 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 5279 while (vp != NULL && (vp->v_type == VMARKER || 5280 (vp->v_iflag & VI_DOOMED) != 0)) 5281 vp = TAILQ_NEXT(vp, v_nmntvnodes); 5282 5283 /* Check if we are done */ 5284 if (vp == NULL) { 5285 __mnt_vnode_markerfree_all(mvp, mp); 5286 /* MNT_IUNLOCK(mp); -- done in above function */ 5287 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5288 return (NULL); 5289 } 5290 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5291 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5292 VI_LOCK(vp); 5293 MNT_IUNLOCK(mp); 5294 return (vp); 5295 } 5296 5297 struct vnode * 5298 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5299 { 5300 struct vnode *vp; 5301 5302 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5303 MNT_ILOCK(mp); 5304 MNT_REF(mp); 5305 (*mvp)->v_type = VMARKER; 5306 5307 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 5308 while (vp != NULL && (vp->v_type == VMARKER || 5309 (vp->v_iflag & VI_DOOMED) != 0)) 5310 vp = TAILQ_NEXT(vp, v_nmntvnodes); 5311 5312 /* Check if we are done */ 5313 if (vp == NULL) { 5314 MNT_REL(mp); 5315 MNT_IUNLOCK(mp); 5316 free(*mvp, M_VNODE_MARKER); 5317 *mvp = NULL; 5318 return (NULL); 5319 } 5320 (*mvp)->v_mount = mp; 5321 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5322 VI_LOCK(vp); 5323 MNT_IUNLOCK(mp); 5324 return (vp); 5325 } 5326 5327 5328 void 5329 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5330 { 5331 5332 if (*mvp == NULL) { 5333 MNT_IUNLOCK(mp); 5334 return; 5335 } 5336 5337 mtx_assert(MNT_MTX(mp), MA_OWNED); 5338 5339 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5340 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5341 MNT_REL(mp); 5342 MNT_IUNLOCK(mp); 5343 free(*mvp, M_VNODE_MARKER); 5344 *mvp = NULL; 5345 } 5346 5347 /* 5348 * These are helper functions for filesystems to traverse their 5349 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5350 */ 5351 static void 5352 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5353 { 5354 5355 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5356 5357 MNT_ILOCK(mp); 5358 MNT_REL(mp); 5359 MNT_IUNLOCK(mp); 5360 free(*mvp, M_VNODE_MARKER); 5361 *mvp = NULL; 5362 } 5363 5364 static struct vnode * 5365 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5366 { 5367 struct vnode *vp, *nvp; 5368 5369 mtx_assert(&mp->mnt_listmtx, MA_OWNED); 5370 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5371 restart: 5372 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5373 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5374 while (vp != NULL) { 5375 if (vp->v_type == VMARKER) { 5376 vp = TAILQ_NEXT(vp, v_actfreelist); 5377 continue; 5378 } 5379 if (!VI_TRYLOCK(vp)) { 5380 if (mp_ncpus == 1 || should_yield()) { 5381 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5382 mtx_unlock(&mp->mnt_listmtx); 5383 pause("vnacti", 1); 5384 mtx_lock(&mp->mnt_listmtx); 5385 goto restart; 5386 } 5387 continue; 5388 } 5389 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5390 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5391 ("alien vnode on the active list %p %p", vp, mp)); 5392 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) 5393 break; 5394 nvp = TAILQ_NEXT(vp, v_actfreelist); 5395 VI_UNLOCK(vp); 5396 vp = nvp; 5397 } 5398 5399 /* Check if we are done */ 5400 if (vp == NULL) { 5401 mtx_unlock(&mp->mnt_listmtx); 5402 mnt_vnode_markerfree_active(mvp, mp); 5403 return (NULL); 5404 } 5405 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 5406 mtx_unlock(&mp->mnt_listmtx); 5407 ASSERT_VI_LOCKED(vp, "active iter"); 5408 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 5409 return (vp); 5410 } 5411 5412 struct vnode * 5413 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5414 { 5415 5416 if (should_yield()) 5417 kern_yield(PRI_USER); 5418 mtx_lock(&mp->mnt_listmtx); 5419 return (mnt_vnode_next_active(mvp, mp)); 5420 } 5421 5422 struct vnode * 5423 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 5424 { 5425 struct vnode *vp; 5426 5427 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5428 MNT_ILOCK(mp); 5429 MNT_REF(mp); 5430 MNT_IUNLOCK(mp); 5431 (*mvp)->v_type = VMARKER; 5432 (*mvp)->v_mount = mp; 5433 5434 mtx_lock(&mp->mnt_listmtx); 5435 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 5436 if (vp == NULL) { 5437 mtx_unlock(&mp->mnt_listmtx); 5438 mnt_vnode_markerfree_active(mvp, mp); 5439 return (NULL); 5440 } 5441 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5442 return (mnt_vnode_next_active(mvp, mp)); 5443 } 5444 5445 void 5446 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5447 { 5448 5449 if (*mvp == NULL) 5450 return; 5451 5452 mtx_lock(&mp->mnt_listmtx); 5453 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5454 mtx_unlock(&mp->mnt_listmtx); 5455 mnt_vnode_markerfree_active(mvp, mp); 5456 } 5457