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 * 4. 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/dirent.h> 55 #include <sys/event.h> 56 #include <sys/eventhandler.h> 57 #include <sys/extattr.h> 58 #include <sys/file.h> 59 #include <sys/fcntl.h> 60 #include <sys/jail.h> 61 #include <sys/kdb.h> 62 #include <sys/kernel.h> 63 #include <sys/kthread.h> 64 #include <sys/lockf.h> 65 #include <sys/malloc.h> 66 #include <sys/mount.h> 67 #include <sys/namei.h> 68 #include <sys/pctrie.h> 69 #include <sys/priv.h> 70 #include <sys/reboot.h> 71 #include <sys/refcount.h> 72 #include <sys/rwlock.h> 73 #include <sys/sched.h> 74 #include <sys/sleepqueue.h> 75 #include <sys/smp.h> 76 #include <sys/stat.h> 77 #include <sys/sysctl.h> 78 #include <sys/syslog.h> 79 #include <sys/vmmeter.h> 80 #include <sys/vnode.h> 81 #include <sys/watchdog.h> 82 83 #include <machine/stdarg.h> 84 85 #include <security/mac/mac_framework.h> 86 87 #include <vm/vm.h> 88 #include <vm/vm_object.h> 89 #include <vm/vm_extern.h> 90 #include <vm/pmap.h> 91 #include <vm/vm_map.h> 92 #include <vm/vm_page.h> 93 #include <vm/vm_kern.h> 94 #include <vm/uma.h> 95 96 #ifdef DDB 97 #include <ddb/ddb.h> 98 #endif 99 100 static void delmntque(struct vnode *vp); 101 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 102 int slpflag, int slptimeo); 103 static void syncer_shutdown(void *arg, int howto); 104 static int vtryrecycle(struct vnode *vp); 105 static void v_init_counters(struct vnode *); 106 static void v_incr_usecount(struct vnode *); 107 static void v_incr_devcount(struct vnode *); 108 static void v_decr_devcount(struct vnode *); 109 static void vnlru_free(int); 110 static void vgonel(struct vnode *); 111 static void vfs_knllock(void *arg); 112 static void vfs_knlunlock(void *arg); 113 static void vfs_knl_assert_locked(void *arg); 114 static void vfs_knl_assert_unlocked(void *arg); 115 static void destroy_vpollinfo(struct vpollinfo *vi); 116 117 /* 118 * Number of vnodes in existence. Increased whenever getnewvnode() 119 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode. 120 */ 121 static unsigned long numvnodes; 122 123 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 124 "Number of vnodes in existence"); 125 126 static u_long vnodes_created; 127 SYSCTL_ULONG(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, 128 0, "Number of vnodes created by getnewvnode"); 129 130 /* 131 * Conversion tables for conversion from vnode types to inode formats 132 * and back. 133 */ 134 enum vtype iftovt_tab[16] = { 135 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 136 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 137 }; 138 int vttoif_tab[10] = { 139 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 140 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 141 }; 142 143 /* 144 * List of vnodes that are ready for recycling. 145 */ 146 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 147 148 /* 149 * "Free" vnode target. Free vnodes are rarely completely free, but are 150 * just ones that are cheap to recycle. Usually they are for files which 151 * have been stat'd but not read; these usually have inode and namecache 152 * data attached to them. This target is the preferred minimum size of a 153 * sub-cache consisting mostly of such files. The system balances the size 154 * of this sub-cache with its complement to try to prevent either from 155 * thrashing while the other is relatively inactive. The targets express 156 * a preference for the best balance. 157 * 158 * "Above" this target there are 2 further targets (watermarks) related 159 * to recyling of free vnodes. In the best-operating case, the cache is 160 * exactly full, the free list has size between vlowat and vhiwat above the 161 * free target, and recycling from it and normal use maintains this state. 162 * Sometimes the free list is below vlowat or even empty, but this state 163 * is even better for immediate use provided the cache is not full. 164 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free 165 * ones) to reach one of these states. The watermarks are currently hard- 166 * coded as 4% and 9% of the available space higher. These and the default 167 * of 25% for wantfreevnodes are too large if the memory size is large. 168 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim 169 * whenever vnlru_proc() becomes active. 170 */ 171 static u_long wantfreevnodes; 172 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, 173 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes"); 174 static u_long freevnodes; 175 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, 176 &freevnodes, 0, "Number of \"free\" vnodes"); 177 178 static u_long recycles_count; 179 SYSCTL_ULONG(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 0, 180 "Number of vnodes recycled to meet vnode cache targets"); 181 182 /* 183 * Various variables used for debugging the new implementation of 184 * reassignbuf(). 185 * XXX these are probably of (very) limited utility now. 186 */ 187 static int reassignbufcalls; 188 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, 189 "Number of calls to reassignbuf"); 190 191 static u_long free_owe_inact; 192 SYSCTL_ULONG(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, 0, 193 "Number of times free vnodes kept on active list due to VFS " 194 "owing inactivation"); 195 196 /* To keep more than one thread at a time from running vfs_getnewfsid */ 197 static struct mtx mntid_mtx; 198 199 /* 200 * Lock for any access to the following: 201 * vnode_free_list 202 * numvnodes 203 * freevnodes 204 */ 205 static struct mtx vnode_free_list_mtx; 206 207 /* Publicly exported FS */ 208 struct nfs_public nfs_pub; 209 210 static uma_zone_t buf_trie_zone; 211 212 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 213 static uma_zone_t vnode_zone; 214 static uma_zone_t vnodepoll_zone; 215 216 /* 217 * The workitem queue. 218 * 219 * It is useful to delay writes of file data and filesystem metadata 220 * for tens of seconds so that quickly created and deleted files need 221 * not waste disk bandwidth being created and removed. To realize this, 222 * we append vnodes to a "workitem" queue. When running with a soft 223 * updates implementation, most pending metadata dependencies should 224 * not wait for more than a few seconds. Thus, mounted on block devices 225 * are delayed only about a half the time that file data is delayed. 226 * Similarly, directory updates are more critical, so are only delayed 227 * about a third the time that file data is delayed. Thus, there are 228 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 229 * one each second (driven off the filesystem syncer process). The 230 * syncer_delayno variable indicates the next queue that is to be processed. 231 * Items that need to be processed soon are placed in this queue: 232 * 233 * syncer_workitem_pending[syncer_delayno] 234 * 235 * A delay of fifteen seconds is done by placing the request fifteen 236 * entries later in the queue: 237 * 238 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 239 * 240 */ 241 static int syncer_delayno; 242 static long syncer_mask; 243 LIST_HEAD(synclist, bufobj); 244 static struct synclist *syncer_workitem_pending; 245 /* 246 * The sync_mtx protects: 247 * bo->bo_synclist 248 * sync_vnode_count 249 * syncer_delayno 250 * syncer_state 251 * syncer_workitem_pending 252 * syncer_worklist_len 253 * rushjob 254 */ 255 static struct mtx sync_mtx; 256 static struct cv sync_wakeup; 257 258 #define SYNCER_MAXDELAY 32 259 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 260 static int syncdelay = 30; /* max time to delay syncing data */ 261 static int filedelay = 30; /* time to delay syncing files */ 262 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 263 "Time to delay syncing files (in seconds)"); 264 static int dirdelay = 29; /* time to delay syncing directories */ 265 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 266 "Time to delay syncing directories (in seconds)"); 267 static int metadelay = 28; /* time to delay syncing metadata */ 268 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 269 "Time to delay syncing metadata (in seconds)"); 270 static int rushjob; /* number of slots to run ASAP */ 271 static int stat_rush_requests; /* number of times I/O speeded up */ 272 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 273 "Number of times I/O speeded up (rush requests)"); 274 275 /* 276 * When shutting down the syncer, run it at four times normal speed. 277 */ 278 #define SYNCER_SHUTDOWN_SPEEDUP 4 279 static int sync_vnode_count; 280 static int syncer_worklist_len; 281 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 282 syncer_state; 283 284 /* Target for maximum number of vnodes. */ 285 int desiredvnodes; 286 static int gapvnodes; /* gap between wanted and desired */ 287 static int vhiwat; /* enough extras after expansion */ 288 static int vlowat; /* minimal extras before expansion */ 289 static int vstir; /* nonzero to stir non-free vnodes */ 290 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ 291 292 static int 293 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS) 294 { 295 int error, old_desiredvnodes; 296 297 old_desiredvnodes = desiredvnodes; 298 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0) 299 return (error); 300 if (old_desiredvnodes != desiredvnodes) { 301 wantfreevnodes = desiredvnodes / 4; 302 /* XXX locking seems to be incomplete. */ 303 vfs_hash_changesize(desiredvnodes); 304 cache_changesize(desiredvnodes); 305 } 306 return (0); 307 } 308 309 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, 310 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0, 311 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes"); 312 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 313 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)"); 314 static int vnlru_nowhere; 315 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 316 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 317 318 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ 319 static int vnsz2log; 320 321 /* 322 * Support for the bufobj clean & dirty pctrie. 323 */ 324 static void * 325 buf_trie_alloc(struct pctrie *ptree) 326 { 327 328 return uma_zalloc(buf_trie_zone, M_NOWAIT); 329 } 330 331 static void 332 buf_trie_free(struct pctrie *ptree, void *node) 333 { 334 335 uma_zfree(buf_trie_zone, node); 336 } 337 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); 338 339 /* 340 * Initialize the vnode management data structures. 341 * 342 * Reevaluate the following cap on the number of vnodes after the physical 343 * memory size exceeds 512GB. In the limit, as the physical memory size 344 * grows, the ratio of the memory size in KB to to vnodes approaches 64:1. 345 */ 346 #ifndef MAXVNODES_MAX 347 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */ 348 #endif 349 350 /* 351 * Initialize a vnode as it first enters the zone. 352 */ 353 static int 354 vnode_init(void *mem, int size, int flags) 355 { 356 struct vnode *vp; 357 struct bufobj *bo; 358 359 vp = mem; 360 bzero(vp, size); 361 /* 362 * Setup locks. 363 */ 364 vp->v_vnlock = &vp->v_lock; 365 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 366 /* 367 * By default, don't allow shared locks unless filesystems opt-in. 368 */ 369 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT, 370 LK_NOSHARE | LK_IS_VNODE); 371 /* 372 * Initialize bufobj. 373 */ 374 bo = &vp->v_bufobj; 375 bo->__bo_vnode = vp; 376 rw_init(BO_LOCKPTR(bo), "bufobj interlock"); 377 bo->bo_private = vp; 378 TAILQ_INIT(&bo->bo_clean.bv_hd); 379 TAILQ_INIT(&bo->bo_dirty.bv_hd); 380 /* 381 * Initialize namecache. 382 */ 383 LIST_INIT(&vp->v_cache_src); 384 TAILQ_INIT(&vp->v_cache_dst); 385 /* 386 * Initialize rangelocks. 387 */ 388 rangelock_init(&vp->v_rl); 389 return (0); 390 } 391 392 /* 393 * Free a vnode when it is cleared from the zone. 394 */ 395 static void 396 vnode_fini(void *mem, int size) 397 { 398 struct vnode *vp; 399 struct bufobj *bo; 400 401 vp = mem; 402 rangelock_destroy(&vp->v_rl); 403 lockdestroy(vp->v_vnlock); 404 mtx_destroy(&vp->v_interlock); 405 bo = &vp->v_bufobj; 406 rw_destroy(BO_LOCKPTR(bo)); 407 } 408 409 static void 410 vntblinit(void *dummy __unused) 411 { 412 u_int i; 413 int physvnodes, virtvnodes; 414 415 /* 416 * Desiredvnodes is a function of the physical memory size and the 417 * kernel's heap size. Generally speaking, it scales with the 418 * physical memory size. The ratio of desiredvnodes to the physical 419 * memory size is 1:16 until desiredvnodes exceeds 98,304. 420 * Thereafter, the 421 * marginal ratio of desiredvnodes to the physical memory size is 422 * 1:64. However, desiredvnodes is limited by the kernel's heap 423 * size. The memory required by desiredvnodes vnodes and vm objects 424 * must not exceed 1/7th of the kernel's heap size. 425 */ 426 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + 427 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; 428 virtvnodes = vm_kmem_size / (7 * (sizeof(struct vm_object) + 429 sizeof(struct vnode))); 430 desiredvnodes = min(physvnodes, virtvnodes); 431 if (desiredvnodes > MAXVNODES_MAX) { 432 if (bootverbose) 433 printf("Reducing kern.maxvnodes %d -> %d\n", 434 desiredvnodes, MAXVNODES_MAX); 435 desiredvnodes = MAXVNODES_MAX; 436 } 437 wantfreevnodes = desiredvnodes / 4; 438 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 439 TAILQ_INIT(&vnode_free_list); 440 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 441 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 442 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); 443 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 444 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 445 /* 446 * Preallocate enough nodes to support one-per buf so that 447 * we can not fail an insert. reassignbuf() callers can not 448 * tolerate the insertion failure. 449 */ 450 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), 451 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, 452 UMA_ZONE_NOFREE | UMA_ZONE_VM); 453 uma_prealloc(buf_trie_zone, nbuf); 454 /* 455 * Initialize the filesystem syncer. 456 */ 457 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 458 &syncer_mask); 459 syncer_maxdelay = syncer_mask + 1; 460 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 461 cv_init(&sync_wakeup, "syncer"); 462 for (i = 1; i <= sizeof(struct vnode); i <<= 1) 463 vnsz2log++; 464 vnsz2log--; 465 } 466 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 467 468 469 /* 470 * Mark a mount point as busy. Used to synchronize access and to delay 471 * unmounting. Eventually, mountlist_mtx is not released on failure. 472 * 473 * vfs_busy() is a custom lock, it can block the caller. 474 * vfs_busy() only sleeps if the unmount is active on the mount point. 475 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 476 * vnode belonging to mp. 477 * 478 * Lookup uses vfs_busy() to traverse mount points. 479 * root fs var fs 480 * / vnode lock A / vnode lock (/var) D 481 * /var vnode lock B /log vnode lock(/var/log) E 482 * vfs_busy lock C vfs_busy lock F 483 * 484 * Within each file system, the lock order is C->A->B and F->D->E. 485 * 486 * When traversing across mounts, the system follows that lock order: 487 * 488 * C->A->B 489 * | 490 * +->F->D->E 491 * 492 * The lookup() process for namei("/var") illustrates the process: 493 * VOP_LOOKUP() obtains B while A is held 494 * vfs_busy() obtains a shared lock on F while A and B are held 495 * vput() releases lock on B 496 * vput() releases lock on A 497 * VFS_ROOT() obtains lock on D while shared lock on F is held 498 * vfs_unbusy() releases shared lock on F 499 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 500 * Attempt to lock A (instead of vp_crossmp) while D is held would 501 * violate the global order, causing deadlocks. 502 * 503 * dounmount() locks B while F is drained. 504 */ 505 int 506 vfs_busy(struct mount *mp, int flags) 507 { 508 509 MPASS((flags & ~MBF_MASK) == 0); 510 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 511 512 MNT_ILOCK(mp); 513 MNT_REF(mp); 514 /* 515 * If mount point is currenly being unmounted, sleep until the 516 * mount point fate is decided. If thread doing the unmounting fails, 517 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 518 * that this mount point has survived the unmount attempt and vfs_busy 519 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 520 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 521 * about to be really destroyed. vfs_busy needs to release its 522 * reference on the mount point in this case and return with ENOENT, 523 * telling the caller that mount mount it tried to busy is no longer 524 * valid. 525 */ 526 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 527 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 528 MNT_REL(mp); 529 MNT_IUNLOCK(mp); 530 CTR1(KTR_VFS, "%s: failed busying before sleeping", 531 __func__); 532 return (ENOENT); 533 } 534 if (flags & MBF_MNTLSTLOCK) 535 mtx_unlock(&mountlist_mtx); 536 mp->mnt_kern_flag |= MNTK_MWAIT; 537 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 538 if (flags & MBF_MNTLSTLOCK) 539 mtx_lock(&mountlist_mtx); 540 MNT_ILOCK(mp); 541 } 542 if (flags & MBF_MNTLSTLOCK) 543 mtx_unlock(&mountlist_mtx); 544 mp->mnt_lockref++; 545 MNT_IUNLOCK(mp); 546 return (0); 547 } 548 549 /* 550 * Free a busy filesystem. 551 */ 552 void 553 vfs_unbusy(struct mount *mp) 554 { 555 556 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 557 MNT_ILOCK(mp); 558 MNT_REL(mp); 559 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref")); 560 mp->mnt_lockref--; 561 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 562 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 563 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 564 mp->mnt_kern_flag &= ~MNTK_DRAINING; 565 wakeup(&mp->mnt_lockref); 566 } 567 MNT_IUNLOCK(mp); 568 } 569 570 /* 571 * Lookup a mount point by filesystem identifier. 572 */ 573 struct mount * 574 vfs_getvfs(fsid_t *fsid) 575 { 576 struct mount *mp; 577 578 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 579 mtx_lock(&mountlist_mtx); 580 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 581 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 582 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 583 vfs_ref(mp); 584 mtx_unlock(&mountlist_mtx); 585 return (mp); 586 } 587 } 588 mtx_unlock(&mountlist_mtx); 589 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 590 return ((struct mount *) 0); 591 } 592 593 /* 594 * Lookup a mount point by filesystem identifier, busying it before 595 * returning. 596 * 597 * To avoid congestion on mountlist_mtx, implement simple direct-mapped 598 * cache for popular filesystem identifiers. The cache is lockess, using 599 * the fact that struct mount's are never freed. In worst case we may 600 * get pointer to unmounted or even different filesystem, so we have to 601 * check what we got, and go slow way if so. 602 */ 603 struct mount * 604 vfs_busyfs(fsid_t *fsid) 605 { 606 #define FSID_CACHE_SIZE 256 607 typedef struct mount * volatile vmp_t; 608 static vmp_t cache[FSID_CACHE_SIZE]; 609 struct mount *mp; 610 int error; 611 uint32_t hash; 612 613 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 614 hash = fsid->val[0] ^ fsid->val[1]; 615 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); 616 mp = cache[hash]; 617 if (mp == NULL || 618 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || 619 mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) 620 goto slow; 621 if (vfs_busy(mp, 0) != 0) { 622 cache[hash] = NULL; 623 goto slow; 624 } 625 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 626 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 627 return (mp); 628 else 629 vfs_unbusy(mp); 630 631 slow: 632 mtx_lock(&mountlist_mtx); 633 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 634 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 635 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 636 error = vfs_busy(mp, MBF_MNTLSTLOCK); 637 if (error) { 638 cache[hash] = NULL; 639 mtx_unlock(&mountlist_mtx); 640 return (NULL); 641 } 642 cache[hash] = mp; 643 return (mp); 644 } 645 } 646 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 647 mtx_unlock(&mountlist_mtx); 648 return ((struct mount *) 0); 649 } 650 651 /* 652 * Check if a user can access privileged mount options. 653 */ 654 int 655 vfs_suser(struct mount *mp, struct thread *td) 656 { 657 int error; 658 659 /* 660 * If the thread is jailed, but this is not a jail-friendly file 661 * system, deny immediately. 662 */ 663 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred)) 664 return (EPERM); 665 666 /* 667 * If the file system was mounted outside the jail of the calling 668 * thread, deny immediately. 669 */ 670 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 671 return (EPERM); 672 673 /* 674 * If file system supports delegated administration, we don't check 675 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 676 * by the file system itself. 677 * If this is not the user that did original mount, we check for 678 * the PRIV_VFS_MOUNT_OWNER privilege. 679 */ 680 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 681 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 682 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 683 return (error); 684 } 685 return (0); 686 } 687 688 /* 689 * Get a new unique fsid. Try to make its val[0] unique, since this value 690 * will be used to create fake device numbers for stat(). Also try (but 691 * not so hard) make its val[0] unique mod 2^16, since some emulators only 692 * support 16-bit device numbers. We end up with unique val[0]'s for the 693 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 694 * 695 * Keep in mind that several mounts may be running in parallel. Starting 696 * the search one past where the previous search terminated is both a 697 * micro-optimization and a defense against returning the same fsid to 698 * different mounts. 699 */ 700 void 701 vfs_getnewfsid(struct mount *mp) 702 { 703 static uint16_t mntid_base; 704 struct mount *nmp; 705 fsid_t tfsid; 706 int mtype; 707 708 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 709 mtx_lock(&mntid_mtx); 710 mtype = mp->mnt_vfc->vfc_typenum; 711 tfsid.val[1] = mtype; 712 mtype = (mtype & 0xFF) << 24; 713 for (;;) { 714 tfsid.val[0] = makedev(255, 715 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 716 mntid_base++; 717 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 718 break; 719 vfs_rel(nmp); 720 } 721 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 722 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 723 mtx_unlock(&mntid_mtx); 724 } 725 726 /* 727 * Knob to control the precision of file timestamps: 728 * 729 * 0 = seconds only; nanoseconds zeroed. 730 * 1 = seconds and nanoseconds, accurate within 1/HZ. 731 * 2 = seconds and nanoseconds, truncated to microseconds. 732 * >=3 = seconds and nanoseconds, maximum precision. 733 */ 734 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 735 736 static int timestamp_precision = TSP_USEC; 737 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 738 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 739 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to ms, " 740 "3+: sec + ns (max. precision))"); 741 742 /* 743 * Get a current timestamp. 744 */ 745 void 746 vfs_timestamp(struct timespec *tsp) 747 { 748 struct timeval tv; 749 750 switch (timestamp_precision) { 751 case TSP_SEC: 752 tsp->tv_sec = time_second; 753 tsp->tv_nsec = 0; 754 break; 755 case TSP_HZ: 756 getnanotime(tsp); 757 break; 758 case TSP_USEC: 759 microtime(&tv); 760 TIMEVAL_TO_TIMESPEC(&tv, tsp); 761 break; 762 case TSP_NSEC: 763 default: 764 nanotime(tsp); 765 break; 766 } 767 } 768 769 /* 770 * Set vnode attributes to VNOVAL 771 */ 772 void 773 vattr_null(struct vattr *vap) 774 { 775 776 vap->va_type = VNON; 777 vap->va_size = VNOVAL; 778 vap->va_bytes = VNOVAL; 779 vap->va_mode = VNOVAL; 780 vap->va_nlink = VNOVAL; 781 vap->va_uid = VNOVAL; 782 vap->va_gid = VNOVAL; 783 vap->va_fsid = VNOVAL; 784 vap->va_fileid = VNOVAL; 785 vap->va_blocksize = VNOVAL; 786 vap->va_rdev = VNOVAL; 787 vap->va_atime.tv_sec = VNOVAL; 788 vap->va_atime.tv_nsec = VNOVAL; 789 vap->va_mtime.tv_sec = VNOVAL; 790 vap->va_mtime.tv_nsec = VNOVAL; 791 vap->va_ctime.tv_sec = VNOVAL; 792 vap->va_ctime.tv_nsec = VNOVAL; 793 vap->va_birthtime.tv_sec = VNOVAL; 794 vap->va_birthtime.tv_nsec = VNOVAL; 795 vap->va_flags = VNOVAL; 796 vap->va_gen = VNOVAL; 797 vap->va_vaflags = 0; 798 } 799 800 /* 801 * This routine is called when we have too many vnodes. It attempts 802 * to free <count> vnodes and will potentially free vnodes that still 803 * have VM backing store (VM backing store is typically the cause 804 * of a vnode blowout so we want to do this). Therefore, this operation 805 * is not considered cheap. 806 * 807 * A number of conditions may prevent a vnode from being reclaimed. 808 * the buffer cache may have references on the vnode, a directory 809 * vnode may still have references due to the namei cache representing 810 * underlying files, or the vnode may be in active use. It is not 811 * desireable to reuse such vnodes. These conditions may cause the 812 * number of vnodes to reach some minimum value regardless of what 813 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 814 */ 815 static int 816 vlrureclaim(struct mount *mp, int reclaim_nc_src, int trigger) 817 { 818 struct vnode *vp; 819 int count, done, target; 820 821 done = 0; 822 vn_start_write(NULL, &mp, V_WAIT); 823 MNT_ILOCK(mp); 824 count = mp->mnt_nvnodelistsize; 825 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1); 826 target = target / 10 + 1; 827 while (count != 0 && done < target) { 828 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 829 while (vp != NULL && vp->v_type == VMARKER) 830 vp = TAILQ_NEXT(vp, v_nmntvnodes); 831 if (vp == NULL) 832 break; 833 /* 834 * XXX LRU is completely broken for non-free vnodes. First 835 * by calling here in mountpoint order, then by moving 836 * unselected vnodes to the end here, and most grossly by 837 * removing the vlruvp() function that was supposed to 838 * maintain the order. (This function was born broken 839 * since syncer problems prevented it doing anything.) The 840 * order is closer to LRC (C = Created). 841 * 842 * LRU reclaiming of vnodes seems to have last worked in 843 * FreeBSD-3 where LRU wasn't mentioned under any spelling. 844 * Then there was no hold count, and inactive vnodes were 845 * simply put on the free list in LRU order. The separate 846 * lists also break LRU. We prefer to reclaim from the 847 * free list for technical reasons. This tends to thrash 848 * the free list to keep very unrecently used held vnodes. 849 * The problem is mitigated by keeping the free list large. 850 */ 851 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 852 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 853 --count; 854 if (!VI_TRYLOCK(vp)) 855 goto next_iter; 856 /* 857 * If it's been deconstructed already, it's still 858 * referenced, or it exceeds the trigger, skip it. 859 * Also skip free vnodes. We are trying to make space 860 * to expand the free list, not reduce it. 861 */ 862 if (vp->v_usecount || 863 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 864 ((vp->v_iflag & VI_FREE) != 0) || 865 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 866 vp->v_object->resident_page_count > trigger)) { 867 VI_UNLOCK(vp); 868 goto next_iter; 869 } 870 MNT_IUNLOCK(mp); 871 vholdl(vp); 872 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 873 vdrop(vp); 874 goto next_iter_mntunlocked; 875 } 876 VI_LOCK(vp); 877 /* 878 * v_usecount may have been bumped after VOP_LOCK() dropped 879 * the vnode interlock and before it was locked again. 880 * 881 * It is not necessary to recheck VI_DOOMED because it can 882 * only be set by another thread that holds both the vnode 883 * lock and vnode interlock. If another thread has the 884 * vnode lock before we get to VOP_LOCK() and obtains the 885 * vnode interlock after VOP_LOCK() drops the vnode 886 * interlock, the other thread will be unable to drop the 887 * vnode lock before our VOP_LOCK() call fails. 888 */ 889 if (vp->v_usecount || 890 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || 891 (vp->v_iflag & VI_FREE) != 0 || 892 (vp->v_object != NULL && 893 vp->v_object->resident_page_count > trigger)) { 894 VOP_UNLOCK(vp, LK_INTERLOCK); 895 vdrop(vp); 896 goto next_iter_mntunlocked; 897 } 898 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 899 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 900 atomic_add_long(&recycles_count, 1); 901 vgonel(vp); 902 VOP_UNLOCK(vp, 0); 903 vdropl(vp); 904 done++; 905 next_iter_mntunlocked: 906 if (!should_yield()) 907 goto relock_mnt; 908 goto yield; 909 next_iter: 910 if (!should_yield()) 911 continue; 912 MNT_IUNLOCK(mp); 913 yield: 914 kern_yield(PRI_USER); 915 relock_mnt: 916 MNT_ILOCK(mp); 917 } 918 MNT_IUNLOCK(mp); 919 vn_finished_write(mp); 920 return done; 921 } 922 923 /* 924 * Attempt to reduce the free list by the requested amount. 925 */ 926 static void 927 vnlru_free(int count) 928 { 929 struct vnode *vp; 930 931 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 932 for (; count > 0; count--) { 933 vp = TAILQ_FIRST(&vnode_free_list); 934 /* 935 * The list can be modified while the free_list_mtx 936 * has been dropped and vp could be NULL here. 937 */ 938 if (!vp) 939 break; 940 VNASSERT(vp->v_op != NULL, vp, 941 ("vnlru_free: vnode already reclaimed.")); 942 KASSERT((vp->v_iflag & VI_FREE) != 0, 943 ("Removing vnode not on freelist")); 944 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 945 ("Mangling active vnode")); 946 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 947 /* 948 * Don't recycle if we can't get the interlock. 949 */ 950 if (!VI_TRYLOCK(vp)) { 951 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist); 952 continue; 953 } 954 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0, 955 vp, ("vp inconsistent on freelist")); 956 957 /* 958 * The clear of VI_FREE prevents activation of the 959 * vnode. There is no sense in putting the vnode on 960 * the mount point active list, only to remove it 961 * later during recycling. Inline the relevant part 962 * of vholdl(), to avoid triggering assertions or 963 * activating. 964 */ 965 freevnodes--; 966 vp->v_iflag &= ~VI_FREE; 967 refcount_acquire(&vp->v_holdcnt); 968 969 mtx_unlock(&vnode_free_list_mtx); 970 VI_UNLOCK(vp); 971 vtryrecycle(vp); 972 /* 973 * If the recycled succeeded this vdrop will actually free 974 * the vnode. If not it will simply place it back on 975 * the free list. 976 */ 977 vdrop(vp); 978 mtx_lock(&vnode_free_list_mtx); 979 } 980 } 981 982 /* XXX some names and initialization are bad for limits and watermarks. */ 983 static int 984 vspace(void) 985 { 986 int space; 987 988 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); 989 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ 990 vlowat = vhiwat / 2; 991 if (numvnodes > desiredvnodes) 992 return (0); 993 space = desiredvnodes - numvnodes; 994 if (freevnodes > wantfreevnodes) 995 space += freevnodes - wantfreevnodes; 996 return (space); 997 } 998 999 /* 1000 * Attempt to recycle vnodes in a context that is always safe to block. 1001 * Calling vlrurecycle() from the bowels of filesystem code has some 1002 * interesting deadlock problems. 1003 */ 1004 static struct proc *vnlruproc; 1005 static int vnlruproc_sig; 1006 1007 static void 1008 vnlru_proc(void) 1009 { 1010 struct mount *mp, *nmp; 1011 unsigned long ofreevnodes, onumvnodes; 1012 int done, force, reclaim_nc_src, trigger, usevnodes; 1013 1014 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, 1015 SHUTDOWN_PRI_FIRST); 1016 1017 force = 0; 1018 for (;;) { 1019 kproc_suspend_check(vnlruproc); 1020 mtx_lock(&vnode_free_list_mtx); 1021 /* 1022 * If numvnodes is too large (due to desiredvnodes being 1023 * adjusted using its sysctl, or emergency growth), first 1024 * try to reduce it by discarding from the free list. 1025 */ 1026 if (numvnodes > desiredvnodes && freevnodes > 0) 1027 vnlru_free(ulmin(numvnodes - desiredvnodes, 1028 freevnodes)); 1029 /* 1030 * Sleep if the vnode cache is in a good state. This is 1031 * when it is not over-full and has space for about a 4% 1032 * or 9% expansion (by growing its size or inexcessively 1033 * reducing its free list). Otherwise, try to reclaim 1034 * space for a 10% expansion. 1035 */ 1036 if (vstir && force == 0) { 1037 force = 1; 1038 vstir = 0; 1039 } 1040 if (vspace() >= vlowat && force == 0) { 1041 vnlruproc_sig = 0; 1042 wakeup(&vnlruproc_sig); 1043 msleep(vnlruproc, &vnode_free_list_mtx, 1044 PVFS|PDROP, "vlruwt", hz); 1045 continue; 1046 } 1047 mtx_unlock(&vnode_free_list_mtx); 1048 done = 0; 1049 ofreevnodes = freevnodes; 1050 onumvnodes = numvnodes; 1051 /* 1052 * Calculate parameters for recycling. These are the same 1053 * throughout the loop to give some semblance of fairness. 1054 * The trigger point is to avoid recycling vnodes with lots 1055 * of resident pages. We aren't trying to free memory; we 1056 * are trying to recycle or at least free vnodes. 1057 */ 1058 if (numvnodes <= desiredvnodes) 1059 usevnodes = numvnodes - freevnodes; 1060 else 1061 usevnodes = numvnodes; 1062 if (usevnodes <= 0) 1063 usevnodes = 1; 1064 /* 1065 * The trigger value is is chosen to give a conservatively 1066 * large value to ensure that it alone doesn't prevent 1067 * making progress. The value can easily be so large that 1068 * it is effectively infinite in some congested and 1069 * misconfigured cases, and this is necessary. Normally 1070 * it is about 8 to 100 (pages), which is quite large. 1071 */ 1072 trigger = vm_cnt.v_page_count * 2 / usevnodes; 1073 if (force < 2) 1074 trigger = vsmalltrigger; 1075 reclaim_nc_src = force >= 3; 1076 mtx_lock(&mountlist_mtx); 1077 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 1078 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { 1079 nmp = TAILQ_NEXT(mp, mnt_list); 1080 continue; 1081 } 1082 done += vlrureclaim(mp, reclaim_nc_src, trigger); 1083 mtx_lock(&mountlist_mtx); 1084 nmp = TAILQ_NEXT(mp, mnt_list); 1085 vfs_unbusy(mp); 1086 } 1087 mtx_unlock(&mountlist_mtx); 1088 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) 1089 uma_reclaim(); 1090 if (done == 0) { 1091 if (force == 0 || force == 1) { 1092 force = 2; 1093 continue; 1094 } 1095 if (force == 2) { 1096 force = 3; 1097 continue; 1098 } 1099 force = 0; 1100 vnlru_nowhere++; 1101 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 1102 } else 1103 kern_yield(PRI_USER); 1104 /* 1105 * After becoming active to expand above low water, keep 1106 * active until above high water. 1107 */ 1108 force = vspace() < vhiwat; 1109 } 1110 } 1111 1112 static struct kproc_desc vnlru_kp = { 1113 "vnlru", 1114 vnlru_proc, 1115 &vnlruproc 1116 }; 1117 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 1118 &vnlru_kp); 1119 1120 /* 1121 * Routines having to do with the management of the vnode table. 1122 */ 1123 1124 /* 1125 * Try to recycle a freed vnode. We abort if anyone picks up a reference 1126 * before we actually vgone(). This function must be called with the vnode 1127 * held to prevent the vnode from being returned to the free list midway 1128 * through vgone(). 1129 */ 1130 static int 1131 vtryrecycle(struct vnode *vp) 1132 { 1133 struct mount *vnmp; 1134 1135 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 1136 VNASSERT(vp->v_holdcnt, vp, 1137 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 1138 /* 1139 * This vnode may found and locked via some other list, if so we 1140 * can't recycle it yet. 1141 */ 1142 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 1143 CTR2(KTR_VFS, 1144 "%s: impossible to recycle, vp %p lock is already held", 1145 __func__, vp); 1146 return (EWOULDBLOCK); 1147 } 1148 /* 1149 * Don't recycle if its filesystem is being suspended. 1150 */ 1151 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 1152 VOP_UNLOCK(vp, 0); 1153 CTR2(KTR_VFS, 1154 "%s: impossible to recycle, cannot start the write for %p", 1155 __func__, vp); 1156 return (EBUSY); 1157 } 1158 /* 1159 * If we got this far, we need to acquire the interlock and see if 1160 * anyone picked up this vnode from another list. If not, we will 1161 * mark it with DOOMED via vgonel() so that anyone who does find it 1162 * will skip over it. 1163 */ 1164 VI_LOCK(vp); 1165 if (vp->v_usecount) { 1166 VOP_UNLOCK(vp, LK_INTERLOCK); 1167 vn_finished_write(vnmp); 1168 CTR2(KTR_VFS, 1169 "%s: impossible to recycle, %p is already referenced", 1170 __func__, vp); 1171 return (EBUSY); 1172 } 1173 if ((vp->v_iflag & VI_DOOMED) == 0) { 1174 atomic_add_long(&recycles_count, 1); 1175 vgonel(vp); 1176 } 1177 VOP_UNLOCK(vp, LK_INTERLOCK); 1178 vn_finished_write(vnmp); 1179 return (0); 1180 } 1181 1182 static void 1183 vcheckspace(void) 1184 { 1185 1186 if (vspace() < vlowat && vnlruproc_sig == 0) { 1187 vnlruproc_sig = 1; 1188 wakeup(vnlruproc); 1189 } 1190 } 1191 1192 /* 1193 * Wait if necessary for space for a new vnode. 1194 */ 1195 static int 1196 getnewvnode_wait(int suspended) 1197 { 1198 1199 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 1200 if (numvnodes >= desiredvnodes) { 1201 if (suspended) { 1202 /* 1203 * The file system is being suspended. We cannot 1204 * risk a deadlock here, so allow allocation of 1205 * another vnode even if this would give too many. 1206 */ 1207 return (0); 1208 } 1209 if (vnlruproc_sig == 0) { 1210 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 1211 wakeup(vnlruproc); 1212 } 1213 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 1214 "vlruwk", hz); 1215 } 1216 /* Post-adjust like the pre-adjust in getnewvnode(). */ 1217 if (numvnodes + 1 > desiredvnodes && freevnodes > 1) 1218 vnlru_free(1); 1219 return (numvnodes >= desiredvnodes ? ENFILE : 0); 1220 } 1221 1222 /* 1223 * This hack is fragile, and probably not needed any more now that the 1224 * watermark handling works. 1225 */ 1226 void 1227 getnewvnode_reserve(u_int count) 1228 { 1229 struct thread *td; 1230 1231 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */ 1232 /* XXX no longer so quick, but this part is not racy. */ 1233 mtx_lock(&vnode_free_list_mtx); 1234 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes) 1235 vnlru_free(ulmin(numvnodes + count - desiredvnodes, 1236 freevnodes - wantfreevnodes)); 1237 mtx_unlock(&vnode_free_list_mtx); 1238 1239 td = curthread; 1240 /* First try to be quick and racy. */ 1241 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) { 1242 td->td_vp_reserv += count; 1243 vcheckspace(); /* XXX no longer so quick, but more racy */ 1244 return; 1245 } else 1246 atomic_subtract_long(&numvnodes, count); 1247 1248 mtx_lock(&vnode_free_list_mtx); 1249 while (count > 0) { 1250 if (getnewvnode_wait(0) == 0) { 1251 count--; 1252 td->td_vp_reserv++; 1253 atomic_add_long(&numvnodes, 1); 1254 } 1255 } 1256 vcheckspace(); 1257 mtx_unlock(&vnode_free_list_mtx); 1258 } 1259 1260 /* 1261 * This hack is fragile, especially if desiredvnodes or wantvnodes are 1262 * misconfgured or changed significantly. Reducing desiredvnodes below 1263 * the reserved amount should cause bizarre behaviour like reducing it 1264 * below the number of active vnodes -- the system will try to reduce 1265 * numvnodes to match, but should fail, so the subtraction below should 1266 * not overflow. 1267 */ 1268 void 1269 getnewvnode_drop_reserve(void) 1270 { 1271 struct thread *td; 1272 1273 td = curthread; 1274 atomic_subtract_long(&numvnodes, td->td_vp_reserv); 1275 td->td_vp_reserv = 0; 1276 } 1277 1278 /* 1279 * Return the next vnode from the free list. 1280 */ 1281 int 1282 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 1283 struct vnode **vpp) 1284 { 1285 struct vnode *vp; 1286 struct thread *td; 1287 struct lock_object *lo; 1288 static int cyclecount; 1289 int error; 1290 1291 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 1292 vp = NULL; 1293 td = curthread; 1294 if (td->td_vp_reserv > 0) { 1295 td->td_vp_reserv -= 1; 1296 goto alloc; 1297 } 1298 mtx_lock(&vnode_free_list_mtx); 1299 if (numvnodes < desiredvnodes) 1300 cyclecount = 0; 1301 else if (cyclecount++ >= freevnodes) { 1302 cyclecount = 0; 1303 vstir = 1; 1304 } 1305 /* 1306 * Grow the vnode cache if it will not be above its target max 1307 * after growing. Otherwise, if the free list is nonempty, try 1308 * to reclaim 1 item from it before growing the cache (possibly 1309 * above its target max if the reclamation failed or is delayed). 1310 * Otherwise, wait for some space. In all cases, schedule 1311 * vnlru_proc() if we are getting short of space. The watermarks 1312 * should be chosen so that we never wait or even reclaim from 1313 * the free list to below its target minimum. 1314 */ 1315 if (numvnodes + 1 <= desiredvnodes) 1316 ; 1317 else if (freevnodes > 0) 1318 vnlru_free(1); 1319 else { 1320 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag & 1321 MNTK_SUSPEND)); 1322 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 1323 if (error != 0) { 1324 mtx_unlock(&vnode_free_list_mtx); 1325 return (error); 1326 } 1327 #endif 1328 } 1329 vcheckspace(); 1330 atomic_add_long(&numvnodes, 1); 1331 mtx_unlock(&vnode_free_list_mtx); 1332 alloc: 1333 atomic_add_long(&vnodes_created, 1); 1334 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 1335 /* 1336 * Locks are given the generic name "vnode" when created. 1337 * Follow the historic practice of using the filesystem 1338 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. 1339 * 1340 * Locks live in a witness group keyed on their name. Thus, 1341 * when a lock is renamed, it must also move from the witness 1342 * group of its old name to the witness group of its new name. 1343 * 1344 * The change only needs to be made when the vnode moves 1345 * from one filesystem type to another. We ensure that each 1346 * filesystem use a single static name pointer for its tag so 1347 * that we can compare pointers rather than doing a strcmp(). 1348 */ 1349 lo = &vp->v_vnlock->lock_object; 1350 if (lo->lo_name != tag) { 1351 lo->lo_name = tag; 1352 WITNESS_DESTROY(lo); 1353 WITNESS_INIT(lo, tag); 1354 } 1355 /* 1356 * By default, don't allow shared locks unless filesystems opt-in. 1357 */ 1358 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; 1359 /* 1360 * Finalize various vnode identity bits. 1361 */ 1362 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); 1363 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); 1364 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); 1365 vp->v_type = VNON; 1366 vp->v_tag = tag; 1367 vp->v_op = vops; 1368 v_init_counters(vp); 1369 vp->v_bufobj.bo_ops = &buf_ops_bio; 1370 #ifdef MAC 1371 mac_vnode_init(vp); 1372 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1373 mac_vnode_associate_singlelabel(mp, vp); 1374 else if (mp == NULL && vops != &dead_vnodeops) 1375 printf("NULL mp in getnewvnode()\n"); 1376 #endif 1377 if (mp != NULL) { 1378 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; 1379 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1380 vp->v_vflag |= VV_NOKNOTE; 1381 } 1382 1383 /* 1384 * For the filesystems which do not use vfs_hash_insert(), 1385 * still initialize v_hash to have vfs_hash_index() useful. 1386 * E.g., nullfs uses vfs_hash_index() on the lower vnode for 1387 * its own hashing. 1388 */ 1389 vp->v_hash = (uintptr_t)vp >> vnsz2log; 1390 1391 *vpp = vp; 1392 return (0); 1393 } 1394 1395 /* 1396 * Delete from old mount point vnode list, if on one. 1397 */ 1398 static void 1399 delmntque(struct vnode *vp) 1400 { 1401 struct mount *mp; 1402 int active; 1403 1404 mp = vp->v_mount; 1405 if (mp == NULL) 1406 return; 1407 MNT_ILOCK(mp); 1408 VI_LOCK(vp); 1409 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize, 1410 ("Active vnode list size %d > Vnode list size %d", 1411 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize)); 1412 active = vp->v_iflag & VI_ACTIVE; 1413 vp->v_iflag &= ~VI_ACTIVE; 1414 if (active) { 1415 mtx_lock(&vnode_free_list_mtx); 1416 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); 1417 mp->mnt_activevnodelistsize--; 1418 mtx_unlock(&vnode_free_list_mtx); 1419 } 1420 vp->v_mount = NULL; 1421 VI_UNLOCK(vp); 1422 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1423 ("bad mount point vnode list size")); 1424 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1425 mp->mnt_nvnodelistsize--; 1426 MNT_REL(mp); 1427 MNT_IUNLOCK(mp); 1428 } 1429 1430 static void 1431 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1432 { 1433 1434 vp->v_data = NULL; 1435 vp->v_op = &dead_vnodeops; 1436 vgone(vp); 1437 vput(vp); 1438 } 1439 1440 /* 1441 * Insert into list of vnodes for the new mount point, if available. 1442 */ 1443 int 1444 insmntque1(struct vnode *vp, struct mount *mp, 1445 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1446 { 1447 1448 KASSERT(vp->v_mount == NULL, 1449 ("insmntque: vnode already on per mount vnode list")); 1450 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1451 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); 1452 1453 /* 1454 * We acquire the vnode interlock early to ensure that the 1455 * vnode cannot be recycled by another process releasing a 1456 * holdcnt on it before we get it on both the vnode list 1457 * and the active vnode list. The mount mutex protects only 1458 * manipulation of the vnode list and the vnode freelist 1459 * mutex protects only manipulation of the active vnode list. 1460 * Hence the need to hold the vnode interlock throughout. 1461 */ 1462 MNT_ILOCK(mp); 1463 VI_LOCK(vp); 1464 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1465 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1466 mp->mnt_nvnodelistsize == 0)) && 1467 (vp->v_vflag & VV_FORCEINSMQ) == 0) { 1468 VI_UNLOCK(vp); 1469 MNT_IUNLOCK(mp); 1470 if (dtr != NULL) 1471 dtr(vp, dtr_arg); 1472 return (EBUSY); 1473 } 1474 vp->v_mount = mp; 1475 MNT_REF(mp); 1476 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1477 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1478 ("neg mount point vnode list size")); 1479 mp->mnt_nvnodelistsize++; 1480 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 1481 ("Activating already active vnode")); 1482 vp->v_iflag |= VI_ACTIVE; 1483 mtx_lock(&vnode_free_list_mtx); 1484 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 1485 mp->mnt_activevnodelistsize++; 1486 mtx_unlock(&vnode_free_list_mtx); 1487 VI_UNLOCK(vp); 1488 MNT_IUNLOCK(mp); 1489 return (0); 1490 } 1491 1492 int 1493 insmntque(struct vnode *vp, struct mount *mp) 1494 { 1495 1496 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1497 } 1498 1499 /* 1500 * Flush out and invalidate all buffers associated with a bufobj 1501 * Called with the underlying object locked. 1502 */ 1503 int 1504 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1505 { 1506 int error; 1507 1508 BO_LOCK(bo); 1509 if (flags & V_SAVE) { 1510 error = bufobj_wwait(bo, slpflag, slptimeo); 1511 if (error) { 1512 BO_UNLOCK(bo); 1513 return (error); 1514 } 1515 if (bo->bo_dirty.bv_cnt > 0) { 1516 BO_UNLOCK(bo); 1517 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1518 return (error); 1519 /* 1520 * XXX We could save a lock/unlock if this was only 1521 * enabled under INVARIANTS 1522 */ 1523 BO_LOCK(bo); 1524 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1525 panic("vinvalbuf: dirty bufs"); 1526 } 1527 } 1528 /* 1529 * If you alter this loop please notice that interlock is dropped and 1530 * reacquired in flushbuflist. Special care is needed to ensure that 1531 * no race conditions occur from this. 1532 */ 1533 do { 1534 error = flushbuflist(&bo->bo_clean, 1535 flags, bo, slpflag, slptimeo); 1536 if (error == 0 && !(flags & V_CLEANONLY)) 1537 error = flushbuflist(&bo->bo_dirty, 1538 flags, bo, slpflag, slptimeo); 1539 if (error != 0 && error != EAGAIN) { 1540 BO_UNLOCK(bo); 1541 return (error); 1542 } 1543 } while (error != 0); 1544 1545 /* 1546 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1547 * have write I/O in-progress but if there is a VM object then the 1548 * VM object can also have read-I/O in-progress. 1549 */ 1550 do { 1551 bufobj_wwait(bo, 0, 0); 1552 BO_UNLOCK(bo); 1553 if (bo->bo_object != NULL) { 1554 VM_OBJECT_WLOCK(bo->bo_object); 1555 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1556 VM_OBJECT_WUNLOCK(bo->bo_object); 1557 } 1558 BO_LOCK(bo); 1559 } while (bo->bo_numoutput > 0); 1560 BO_UNLOCK(bo); 1561 1562 /* 1563 * Destroy the copy in the VM cache, too. 1564 */ 1565 if (bo->bo_object != NULL && 1566 (flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) { 1567 VM_OBJECT_WLOCK(bo->bo_object); 1568 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1569 OBJPR_CLEANONLY : 0); 1570 VM_OBJECT_WUNLOCK(bo->bo_object); 1571 } 1572 1573 #ifdef INVARIANTS 1574 BO_LOCK(bo); 1575 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 && 1576 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0)) 1577 panic("vinvalbuf: flush failed"); 1578 BO_UNLOCK(bo); 1579 #endif 1580 return (0); 1581 } 1582 1583 /* 1584 * Flush out and invalidate all buffers associated with a vnode. 1585 * Called with the underlying object locked. 1586 */ 1587 int 1588 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1589 { 1590 1591 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1592 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1593 if (vp->v_object != NULL && vp->v_object->handle != vp) 1594 return (0); 1595 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1596 } 1597 1598 /* 1599 * Flush out buffers on the specified list. 1600 * 1601 */ 1602 static int 1603 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1604 int slptimeo) 1605 { 1606 struct buf *bp, *nbp; 1607 int retval, error; 1608 daddr_t lblkno; 1609 b_xflags_t xflags; 1610 1611 ASSERT_BO_WLOCKED(bo); 1612 1613 retval = 0; 1614 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1615 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1616 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1617 continue; 1618 } 1619 lblkno = 0; 1620 xflags = 0; 1621 if (nbp != NULL) { 1622 lblkno = nbp->b_lblkno; 1623 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); 1624 } 1625 retval = EAGAIN; 1626 error = BUF_TIMELOCK(bp, 1627 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo), 1628 "flushbuf", slpflag, slptimeo); 1629 if (error) { 1630 BO_LOCK(bo); 1631 return (error != ENOLCK ? error : EAGAIN); 1632 } 1633 KASSERT(bp->b_bufobj == bo, 1634 ("bp %p wrong b_bufobj %p should be %p", 1635 bp, bp->b_bufobj, bo)); 1636 /* 1637 * XXX Since there are no node locks for NFS, I 1638 * believe there is a slight chance that a delayed 1639 * write will occur while sleeping just above, so 1640 * check for it. 1641 */ 1642 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1643 (flags & V_SAVE)) { 1644 bremfree(bp); 1645 bp->b_flags |= B_ASYNC; 1646 bwrite(bp); 1647 BO_LOCK(bo); 1648 return (EAGAIN); /* XXX: why not loop ? */ 1649 } 1650 bremfree(bp); 1651 bp->b_flags |= (B_INVAL | B_RELBUF); 1652 bp->b_flags &= ~B_ASYNC; 1653 brelse(bp); 1654 BO_LOCK(bo); 1655 if (nbp != NULL && 1656 (nbp->b_bufobj != bo || 1657 nbp->b_lblkno != lblkno || 1658 (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) != xflags)) 1659 break; /* nbp invalid */ 1660 } 1661 return (retval); 1662 } 1663 1664 /* 1665 * Truncate a file's buffer and pages to a specified length. This 1666 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1667 * sync activity. 1668 */ 1669 int 1670 vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize) 1671 { 1672 struct buf *bp, *nbp; 1673 int anyfreed; 1674 int trunclbn; 1675 struct bufobj *bo; 1676 1677 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__, 1678 vp, cred, blksize, (uintmax_t)length); 1679 1680 /* 1681 * Round up to the *next* lbn. 1682 */ 1683 trunclbn = (length + blksize - 1) / blksize; 1684 1685 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1686 restart: 1687 bo = &vp->v_bufobj; 1688 BO_LOCK(bo); 1689 anyfreed = 1; 1690 for (;anyfreed;) { 1691 anyfreed = 0; 1692 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1693 if (bp->b_lblkno < trunclbn) 1694 continue; 1695 if (BUF_LOCK(bp, 1696 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1697 BO_LOCKPTR(bo)) == ENOLCK) 1698 goto restart; 1699 1700 bremfree(bp); 1701 bp->b_flags |= (B_INVAL | B_RELBUF); 1702 bp->b_flags &= ~B_ASYNC; 1703 brelse(bp); 1704 anyfreed = 1; 1705 1706 BO_LOCK(bo); 1707 if (nbp != NULL && 1708 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1709 (nbp->b_vp != vp) || 1710 (nbp->b_flags & B_DELWRI))) { 1711 BO_UNLOCK(bo); 1712 goto restart; 1713 } 1714 } 1715 1716 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1717 if (bp->b_lblkno < trunclbn) 1718 continue; 1719 if (BUF_LOCK(bp, 1720 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1721 BO_LOCKPTR(bo)) == ENOLCK) 1722 goto restart; 1723 bremfree(bp); 1724 bp->b_flags |= (B_INVAL | B_RELBUF); 1725 bp->b_flags &= ~B_ASYNC; 1726 brelse(bp); 1727 anyfreed = 1; 1728 1729 BO_LOCK(bo); 1730 if (nbp != NULL && 1731 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1732 (nbp->b_vp != vp) || 1733 (nbp->b_flags & B_DELWRI) == 0)) { 1734 BO_UNLOCK(bo); 1735 goto restart; 1736 } 1737 } 1738 } 1739 1740 if (length > 0) { 1741 restartsync: 1742 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1743 if (bp->b_lblkno > 0) 1744 continue; 1745 /* 1746 * Since we hold the vnode lock this should only 1747 * fail if we're racing with the buf daemon. 1748 */ 1749 if (BUF_LOCK(bp, 1750 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1751 BO_LOCKPTR(bo)) == ENOLCK) { 1752 goto restart; 1753 } 1754 VNASSERT((bp->b_flags & B_DELWRI), vp, 1755 ("buf(%p) on dirty queue without DELWRI", bp)); 1756 1757 bremfree(bp); 1758 bawrite(bp); 1759 BO_LOCK(bo); 1760 goto restartsync; 1761 } 1762 } 1763 1764 bufobj_wwait(bo, 0, 0); 1765 BO_UNLOCK(bo); 1766 vnode_pager_setsize(vp, length); 1767 1768 return (0); 1769 } 1770 1771 static void 1772 buf_vlist_remove(struct buf *bp) 1773 { 1774 struct bufv *bv; 1775 1776 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1777 ASSERT_BO_WLOCKED(bp->b_bufobj); 1778 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1779 (BX_VNDIRTY|BX_VNCLEAN), 1780 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1781 if (bp->b_xflags & BX_VNDIRTY) 1782 bv = &bp->b_bufobj->bo_dirty; 1783 else 1784 bv = &bp->b_bufobj->bo_clean; 1785 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); 1786 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1787 bv->bv_cnt--; 1788 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1789 } 1790 1791 /* 1792 * Add the buffer to the sorted clean or dirty block list. 1793 * 1794 * NOTE: xflags is passed as a constant, optimizing this inline function! 1795 */ 1796 static void 1797 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1798 { 1799 struct bufv *bv; 1800 struct buf *n; 1801 int error; 1802 1803 ASSERT_BO_WLOCKED(bo); 1804 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, 1805 ("dead bo %p", bo)); 1806 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1807 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1808 bp->b_xflags |= xflags; 1809 if (xflags & BX_VNDIRTY) 1810 bv = &bo->bo_dirty; 1811 else 1812 bv = &bo->bo_clean; 1813 1814 /* 1815 * Keep the list ordered. Optimize empty list insertion. Assume 1816 * we tend to grow at the tail so lookup_le should usually be cheaper 1817 * than _ge. 1818 */ 1819 if (bv->bv_cnt == 0 || 1820 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) 1821 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1822 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) 1823 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); 1824 else 1825 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); 1826 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); 1827 if (error) 1828 panic("buf_vlist_add: Preallocated nodes insufficient."); 1829 bv->bv_cnt++; 1830 } 1831 1832 /* 1833 * Look up a buffer using the buffer tries. 1834 */ 1835 struct buf * 1836 gbincore(struct bufobj *bo, daddr_t lblkno) 1837 { 1838 struct buf *bp; 1839 1840 ASSERT_BO_LOCKED(bo); 1841 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); 1842 if (bp != NULL) 1843 return (bp); 1844 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); 1845 } 1846 1847 /* 1848 * Associate a buffer with a vnode. 1849 */ 1850 void 1851 bgetvp(struct vnode *vp, struct buf *bp) 1852 { 1853 struct bufobj *bo; 1854 1855 bo = &vp->v_bufobj; 1856 ASSERT_BO_WLOCKED(bo); 1857 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 1858 1859 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 1860 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 1861 ("bgetvp: bp already attached! %p", bp)); 1862 1863 vhold(vp); 1864 bp->b_vp = vp; 1865 bp->b_bufobj = bo; 1866 /* 1867 * Insert onto list for new vnode. 1868 */ 1869 buf_vlist_add(bp, bo, BX_VNCLEAN); 1870 } 1871 1872 /* 1873 * Disassociate a buffer from a vnode. 1874 */ 1875 void 1876 brelvp(struct buf *bp) 1877 { 1878 struct bufobj *bo; 1879 struct vnode *vp; 1880 1881 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 1882 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1883 1884 /* 1885 * Delete from old vnode list, if on one. 1886 */ 1887 vp = bp->b_vp; /* XXX */ 1888 bo = bp->b_bufobj; 1889 BO_LOCK(bo); 1890 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1891 buf_vlist_remove(bp); 1892 else 1893 panic("brelvp: Buffer %p not on queue.", bp); 1894 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1895 bo->bo_flag &= ~BO_ONWORKLST; 1896 mtx_lock(&sync_mtx); 1897 LIST_REMOVE(bo, bo_synclist); 1898 syncer_worklist_len--; 1899 mtx_unlock(&sync_mtx); 1900 } 1901 bp->b_vp = NULL; 1902 bp->b_bufobj = NULL; 1903 BO_UNLOCK(bo); 1904 vdrop(vp); 1905 } 1906 1907 /* 1908 * Add an item to the syncer work queue. 1909 */ 1910 static void 1911 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 1912 { 1913 int slot; 1914 1915 ASSERT_BO_WLOCKED(bo); 1916 1917 mtx_lock(&sync_mtx); 1918 if (bo->bo_flag & BO_ONWORKLST) 1919 LIST_REMOVE(bo, bo_synclist); 1920 else { 1921 bo->bo_flag |= BO_ONWORKLST; 1922 syncer_worklist_len++; 1923 } 1924 1925 if (delay > syncer_maxdelay - 2) 1926 delay = syncer_maxdelay - 2; 1927 slot = (syncer_delayno + delay) & syncer_mask; 1928 1929 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 1930 mtx_unlock(&sync_mtx); 1931 } 1932 1933 static int 1934 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1935 { 1936 int error, len; 1937 1938 mtx_lock(&sync_mtx); 1939 len = syncer_worklist_len - sync_vnode_count; 1940 mtx_unlock(&sync_mtx); 1941 error = SYSCTL_OUT(req, &len, sizeof(len)); 1942 return (error); 1943 } 1944 1945 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1946 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1947 1948 static struct proc *updateproc; 1949 static void sched_sync(void); 1950 static struct kproc_desc up_kp = { 1951 "syncer", 1952 sched_sync, 1953 &updateproc 1954 }; 1955 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 1956 1957 static int 1958 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 1959 { 1960 struct vnode *vp; 1961 struct mount *mp; 1962 1963 *bo = LIST_FIRST(slp); 1964 if (*bo == NULL) 1965 return (0); 1966 vp = (*bo)->__bo_vnode; /* XXX */ 1967 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 1968 return (1); 1969 /* 1970 * We use vhold in case the vnode does not 1971 * successfully sync. vhold prevents the vnode from 1972 * going away when we unlock the sync_mtx so that 1973 * we can acquire the vnode interlock. 1974 */ 1975 vholdl(vp); 1976 mtx_unlock(&sync_mtx); 1977 VI_UNLOCK(vp); 1978 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1979 vdrop(vp); 1980 mtx_lock(&sync_mtx); 1981 return (*bo == LIST_FIRST(slp)); 1982 } 1983 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1984 (void) VOP_FSYNC(vp, MNT_LAZY, td); 1985 VOP_UNLOCK(vp, 0); 1986 vn_finished_write(mp); 1987 BO_LOCK(*bo); 1988 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 1989 /* 1990 * Put us back on the worklist. The worklist 1991 * routine will remove us from our current 1992 * position and then add us back in at a later 1993 * position. 1994 */ 1995 vn_syncer_add_to_worklist(*bo, syncdelay); 1996 } 1997 BO_UNLOCK(*bo); 1998 vdrop(vp); 1999 mtx_lock(&sync_mtx); 2000 return (0); 2001 } 2002 2003 static int first_printf = 1; 2004 2005 /* 2006 * System filesystem synchronizer daemon. 2007 */ 2008 static void 2009 sched_sync(void) 2010 { 2011 struct synclist *next, *slp; 2012 struct bufobj *bo; 2013 long starttime; 2014 struct thread *td = curthread; 2015 int last_work_seen; 2016 int net_worklist_len; 2017 int syncer_final_iter; 2018 int error; 2019 2020 last_work_seen = 0; 2021 syncer_final_iter = 0; 2022 syncer_state = SYNCER_RUNNING; 2023 starttime = time_uptime; 2024 td->td_pflags |= TDP_NORUNNINGBUF; 2025 2026 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 2027 SHUTDOWN_PRI_LAST); 2028 2029 mtx_lock(&sync_mtx); 2030 for (;;) { 2031 if (syncer_state == SYNCER_FINAL_DELAY && 2032 syncer_final_iter == 0) { 2033 mtx_unlock(&sync_mtx); 2034 kproc_suspend_check(td->td_proc); 2035 mtx_lock(&sync_mtx); 2036 } 2037 net_worklist_len = syncer_worklist_len - sync_vnode_count; 2038 if (syncer_state != SYNCER_RUNNING && 2039 starttime != time_uptime) { 2040 if (first_printf) { 2041 printf("\nSyncing disks, vnodes remaining..."); 2042 first_printf = 0; 2043 } 2044 printf("%d ", net_worklist_len); 2045 } 2046 starttime = time_uptime; 2047 2048 /* 2049 * Push files whose dirty time has expired. Be careful 2050 * of interrupt race on slp queue. 2051 * 2052 * Skip over empty worklist slots when shutting down. 2053 */ 2054 do { 2055 slp = &syncer_workitem_pending[syncer_delayno]; 2056 syncer_delayno += 1; 2057 if (syncer_delayno == syncer_maxdelay) 2058 syncer_delayno = 0; 2059 next = &syncer_workitem_pending[syncer_delayno]; 2060 /* 2061 * If the worklist has wrapped since the 2062 * it was emptied of all but syncer vnodes, 2063 * switch to the FINAL_DELAY state and run 2064 * for one more second. 2065 */ 2066 if (syncer_state == SYNCER_SHUTTING_DOWN && 2067 net_worklist_len == 0 && 2068 last_work_seen == syncer_delayno) { 2069 syncer_state = SYNCER_FINAL_DELAY; 2070 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 2071 } 2072 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 2073 syncer_worklist_len > 0); 2074 2075 /* 2076 * Keep track of the last time there was anything 2077 * on the worklist other than syncer vnodes. 2078 * Return to the SHUTTING_DOWN state if any 2079 * new work appears. 2080 */ 2081 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 2082 last_work_seen = syncer_delayno; 2083 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 2084 syncer_state = SYNCER_SHUTTING_DOWN; 2085 while (!LIST_EMPTY(slp)) { 2086 error = sync_vnode(slp, &bo, td); 2087 if (error == 1) { 2088 LIST_REMOVE(bo, bo_synclist); 2089 LIST_INSERT_HEAD(next, bo, bo_synclist); 2090 continue; 2091 } 2092 2093 if (first_printf == 0) { 2094 /* 2095 * Drop the sync mutex, because some watchdog 2096 * drivers need to sleep while patting 2097 */ 2098 mtx_unlock(&sync_mtx); 2099 wdog_kern_pat(WD_LASTVAL); 2100 mtx_lock(&sync_mtx); 2101 } 2102 2103 } 2104 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 2105 syncer_final_iter--; 2106 /* 2107 * The variable rushjob allows the kernel to speed up the 2108 * processing of the filesystem syncer process. A rushjob 2109 * value of N tells the filesystem syncer to process the next 2110 * N seconds worth of work on its queue ASAP. Currently rushjob 2111 * is used by the soft update code to speed up the filesystem 2112 * syncer process when the incore state is getting so far 2113 * ahead of the disk that the kernel memory pool is being 2114 * threatened with exhaustion. 2115 */ 2116 if (rushjob > 0) { 2117 rushjob -= 1; 2118 continue; 2119 } 2120 /* 2121 * Just sleep for a short period of time between 2122 * iterations when shutting down to allow some I/O 2123 * to happen. 2124 * 2125 * If it has taken us less than a second to process the 2126 * current work, then wait. Otherwise start right over 2127 * again. We can still lose time if any single round 2128 * takes more than two seconds, but it does not really 2129 * matter as we are just trying to generally pace the 2130 * filesystem activity. 2131 */ 2132 if (syncer_state != SYNCER_RUNNING || 2133 time_uptime == starttime) { 2134 thread_lock(td); 2135 sched_prio(td, PPAUSE); 2136 thread_unlock(td); 2137 } 2138 if (syncer_state != SYNCER_RUNNING) 2139 cv_timedwait(&sync_wakeup, &sync_mtx, 2140 hz / SYNCER_SHUTDOWN_SPEEDUP); 2141 else if (time_uptime == starttime) 2142 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 2143 } 2144 } 2145 2146 /* 2147 * Request the syncer daemon to speed up its work. 2148 * We never push it to speed up more than half of its 2149 * normal turn time, otherwise it could take over the cpu. 2150 */ 2151 int 2152 speedup_syncer(void) 2153 { 2154 int ret = 0; 2155 2156 mtx_lock(&sync_mtx); 2157 if (rushjob < syncdelay / 2) { 2158 rushjob += 1; 2159 stat_rush_requests += 1; 2160 ret = 1; 2161 } 2162 mtx_unlock(&sync_mtx); 2163 cv_broadcast(&sync_wakeup); 2164 return (ret); 2165 } 2166 2167 /* 2168 * Tell the syncer to speed up its work and run though its work 2169 * list several times, then tell it to shut down. 2170 */ 2171 static void 2172 syncer_shutdown(void *arg, int howto) 2173 { 2174 2175 if (howto & RB_NOSYNC) 2176 return; 2177 mtx_lock(&sync_mtx); 2178 syncer_state = SYNCER_SHUTTING_DOWN; 2179 rushjob = 0; 2180 mtx_unlock(&sync_mtx); 2181 cv_broadcast(&sync_wakeup); 2182 kproc_shutdown(arg, howto); 2183 } 2184 2185 void 2186 syncer_suspend(void) 2187 { 2188 2189 syncer_shutdown(updateproc, 0); 2190 } 2191 2192 void 2193 syncer_resume(void) 2194 { 2195 2196 mtx_lock(&sync_mtx); 2197 first_printf = 1; 2198 syncer_state = SYNCER_RUNNING; 2199 mtx_unlock(&sync_mtx); 2200 cv_broadcast(&sync_wakeup); 2201 kproc_resume(updateproc); 2202 } 2203 2204 /* 2205 * Reassign a buffer from one vnode to another. 2206 * Used to assign file specific control information 2207 * (indirect blocks) to the vnode to which they belong. 2208 */ 2209 void 2210 reassignbuf(struct buf *bp) 2211 { 2212 struct vnode *vp; 2213 struct bufobj *bo; 2214 int delay; 2215 #ifdef INVARIANTS 2216 struct bufv *bv; 2217 #endif 2218 2219 vp = bp->b_vp; 2220 bo = bp->b_bufobj; 2221 ++reassignbufcalls; 2222 2223 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 2224 bp, bp->b_vp, bp->b_flags); 2225 /* 2226 * B_PAGING flagged buffers cannot be reassigned because their vp 2227 * is not fully linked in. 2228 */ 2229 if (bp->b_flags & B_PAGING) 2230 panic("cannot reassign paging buffer"); 2231 2232 /* 2233 * Delete from old vnode list, if on one. 2234 */ 2235 BO_LOCK(bo); 2236 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2237 buf_vlist_remove(bp); 2238 else 2239 panic("reassignbuf: Buffer %p not on queue.", bp); 2240 /* 2241 * If dirty, put on list of dirty buffers; otherwise insert onto list 2242 * of clean buffers. 2243 */ 2244 if (bp->b_flags & B_DELWRI) { 2245 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2246 switch (vp->v_type) { 2247 case VDIR: 2248 delay = dirdelay; 2249 break; 2250 case VCHR: 2251 delay = metadelay; 2252 break; 2253 default: 2254 delay = filedelay; 2255 } 2256 vn_syncer_add_to_worklist(bo, delay); 2257 } 2258 buf_vlist_add(bp, bo, BX_VNDIRTY); 2259 } else { 2260 buf_vlist_add(bp, bo, BX_VNCLEAN); 2261 2262 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2263 mtx_lock(&sync_mtx); 2264 LIST_REMOVE(bo, bo_synclist); 2265 syncer_worklist_len--; 2266 mtx_unlock(&sync_mtx); 2267 bo->bo_flag &= ~BO_ONWORKLST; 2268 } 2269 } 2270 #ifdef INVARIANTS 2271 bv = &bo->bo_clean; 2272 bp = TAILQ_FIRST(&bv->bv_hd); 2273 KASSERT(bp == NULL || bp->b_bufobj == bo, 2274 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2275 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2276 KASSERT(bp == NULL || bp->b_bufobj == bo, 2277 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2278 bv = &bo->bo_dirty; 2279 bp = TAILQ_FIRST(&bv->bv_hd); 2280 KASSERT(bp == NULL || bp->b_bufobj == bo, 2281 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2282 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2283 KASSERT(bp == NULL || bp->b_bufobj == bo, 2284 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2285 #endif 2286 BO_UNLOCK(bo); 2287 } 2288 2289 /* 2290 * A temporary hack until refcount_* APIs are sorted out. 2291 */ 2292 static __inline int 2293 vfs_refcount_acquire_if_not_zero(volatile u_int *count) 2294 { 2295 u_int old; 2296 2297 for (;;) { 2298 old = *count; 2299 if (old == 0) 2300 return (0); 2301 if (atomic_cmpset_int(count, old, old + 1)) 2302 return (1); 2303 } 2304 } 2305 2306 static __inline int 2307 vfs_refcount_release_if_not_last(volatile u_int *count) 2308 { 2309 u_int old; 2310 2311 for (;;) { 2312 old = *count; 2313 if (old == 1) 2314 return (0); 2315 if (atomic_cmpset_int(count, old, old - 1)) 2316 return (1); 2317 } 2318 } 2319 2320 static void 2321 v_init_counters(struct vnode *vp) 2322 { 2323 2324 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, 2325 vp, ("%s called for an initialized vnode", __FUNCTION__)); 2326 ASSERT_VI_UNLOCKED(vp, __FUNCTION__); 2327 2328 refcount_init(&vp->v_holdcnt, 1); 2329 refcount_init(&vp->v_usecount, 1); 2330 } 2331 2332 /* 2333 * Increment the use and hold counts on the vnode, taking care to reference 2334 * the driver's usecount if this is a chardev. The _vhold() will remove 2335 * the vnode from the free list if it is presently free. 2336 */ 2337 static void 2338 v_incr_usecount(struct vnode *vp) 2339 { 2340 2341 ASSERT_VI_UNLOCKED(vp, __func__); 2342 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2343 2344 if (vp->v_type == VCHR) { 2345 VI_LOCK(vp); 2346 _vhold(vp, true); 2347 if (vp->v_iflag & VI_OWEINACT) { 2348 VNASSERT(vp->v_usecount == 0, vp, 2349 ("vnode with usecount and VI_OWEINACT set")); 2350 vp->v_iflag &= ~VI_OWEINACT; 2351 } 2352 refcount_acquire(&vp->v_usecount); 2353 v_incr_devcount(vp); 2354 VI_UNLOCK(vp); 2355 return; 2356 } 2357 2358 _vhold(vp, false); 2359 if (vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) { 2360 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2361 ("vnode with usecount and VI_OWEINACT set")); 2362 } else { 2363 VI_LOCK(vp); 2364 if (vp->v_iflag & VI_OWEINACT) 2365 vp->v_iflag &= ~VI_OWEINACT; 2366 refcount_acquire(&vp->v_usecount); 2367 VI_UNLOCK(vp); 2368 } 2369 } 2370 2371 /* 2372 * Increment si_usecount of the associated device, if any. 2373 */ 2374 static void 2375 v_incr_devcount(struct vnode *vp) 2376 { 2377 2378 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2379 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2380 dev_lock(); 2381 vp->v_rdev->si_usecount++; 2382 dev_unlock(); 2383 } 2384 } 2385 2386 /* 2387 * Decrement si_usecount of the associated device, if any. 2388 */ 2389 static void 2390 v_decr_devcount(struct vnode *vp) 2391 { 2392 2393 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2394 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2395 dev_lock(); 2396 vp->v_rdev->si_usecount--; 2397 dev_unlock(); 2398 } 2399 } 2400 2401 /* 2402 * Grab a particular vnode from the free list, increment its 2403 * reference count and lock it. VI_DOOMED is set if the vnode 2404 * is being destroyed. Only callers who specify LK_RETRY will 2405 * see doomed vnodes. If inactive processing was delayed in 2406 * vput try to do it here. 2407 * 2408 * Notes on lockless counter manipulation: 2409 * _vhold, vputx and other routines make various decisions based 2410 * on either holdcnt or usecount being 0. As long as either contuner 2411 * is not transitioning 0->1 nor 1->0, the manipulation can be done 2412 * with atomic operations. Otherwise the interlock is taken. 2413 */ 2414 int 2415 vget(struct vnode *vp, int flags, struct thread *td) 2416 { 2417 int error, oweinact; 2418 2419 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2420 ("vget: invalid lock operation")); 2421 2422 if ((flags & LK_INTERLOCK) != 0) 2423 ASSERT_VI_LOCKED(vp, __func__); 2424 else 2425 ASSERT_VI_UNLOCKED(vp, __func__); 2426 if ((flags & LK_VNHELD) != 0) 2427 VNASSERT((vp->v_holdcnt > 0), vp, 2428 ("vget: LK_VNHELD passed but vnode not held")); 2429 2430 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2431 2432 if ((flags & LK_VNHELD) == 0) 2433 _vhold(vp, (flags & LK_INTERLOCK) != 0); 2434 2435 if ((error = vn_lock(vp, flags)) != 0) { 2436 vdrop(vp); 2437 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2438 vp); 2439 return (error); 2440 } 2441 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2442 panic("vget: vn_lock failed to return ENOENT\n"); 2443 /* 2444 * We don't guarantee that any particular close will 2445 * trigger inactive processing so just make a best effort 2446 * here at preventing a reference to a removed file. If 2447 * we don't succeed no harm is done. 2448 * 2449 * Upgrade our holdcnt to a usecount. 2450 */ 2451 if (vp->v_type != VCHR && 2452 vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) { 2453 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2454 ("vnode with usecount and VI_OWEINACT set")); 2455 } else { 2456 VI_LOCK(vp); 2457 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2458 oweinact = 0; 2459 } else { 2460 oweinact = 1; 2461 vp->v_iflag &= ~VI_OWEINACT; 2462 } 2463 refcount_acquire(&vp->v_usecount); 2464 v_incr_devcount(vp); 2465 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2466 (flags & LK_NOWAIT) == 0) 2467 vinactive(vp, td); 2468 VI_UNLOCK(vp); 2469 } 2470 return (0); 2471 } 2472 2473 /* 2474 * Increase the reference count of a vnode. 2475 */ 2476 void 2477 vref(struct vnode *vp) 2478 { 2479 2480 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2481 v_incr_usecount(vp); 2482 } 2483 2484 /* 2485 * Return reference count of a vnode. 2486 * 2487 * The results of this call are only guaranteed when some mechanism is used to 2488 * stop other processes from gaining references to the vnode. This may be the 2489 * case if the caller holds the only reference. This is also useful when stale 2490 * data is acceptable as race conditions may be accounted for by some other 2491 * means. 2492 */ 2493 int 2494 vrefcnt(struct vnode *vp) 2495 { 2496 2497 return (vp->v_usecount); 2498 } 2499 2500 #define VPUTX_VRELE 1 2501 #define VPUTX_VPUT 2 2502 #define VPUTX_VUNREF 3 2503 2504 /* 2505 * Decrement the use and hold counts for a vnode. 2506 * 2507 * See an explanation near vget() as to why atomic operation is safe. 2508 */ 2509 static void 2510 vputx(struct vnode *vp, int func) 2511 { 2512 int error; 2513 2514 KASSERT(vp != NULL, ("vputx: null vp")); 2515 if (func == VPUTX_VUNREF) 2516 ASSERT_VOP_LOCKED(vp, "vunref"); 2517 else if (func == VPUTX_VPUT) 2518 ASSERT_VOP_LOCKED(vp, "vput"); 2519 else 2520 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); 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_release_if_not_last(&vp->v_usecount)) { 2526 if (func == VPUTX_VPUT) 2527 VOP_UNLOCK(vp, 0); 2528 vdrop(vp); 2529 return; 2530 } 2531 2532 VI_LOCK(vp); 2533 2534 /* 2535 * We want to hold the vnode until the inactive finishes to 2536 * prevent vgone() races. We drop the use count here and the 2537 * hold count below when we're done. 2538 */ 2539 if (!refcount_release(&vp->v_usecount) || 2540 (vp->v_iflag & VI_DOINGINACT)) { 2541 if (func == VPUTX_VPUT) 2542 VOP_UNLOCK(vp, 0); 2543 v_decr_devcount(vp); 2544 vdropl(vp); 2545 return; 2546 } 2547 2548 v_decr_devcount(vp); 2549 2550 error = 0; 2551 2552 if (vp->v_usecount != 0) { 2553 vprint("vputx: usecount not zero", vp); 2554 panic("vputx: usecount not zero"); 2555 } 2556 2557 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); 2558 2559 /* 2560 * We must call VOP_INACTIVE with the node locked. Mark 2561 * as VI_DOINGINACT to avoid recursion. 2562 */ 2563 vp->v_iflag |= VI_OWEINACT; 2564 switch (func) { 2565 case VPUTX_VRELE: 2566 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2567 VI_LOCK(vp); 2568 break; 2569 case VPUTX_VPUT: 2570 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2571 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 2572 LK_NOWAIT); 2573 VI_LOCK(vp); 2574 } 2575 break; 2576 case VPUTX_VUNREF: 2577 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2578 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); 2579 VI_LOCK(vp); 2580 } 2581 break; 2582 } 2583 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, 2584 ("vnode with usecount and VI_OWEINACT set")); 2585 if (error == 0) { 2586 if (vp->v_iflag & VI_OWEINACT) 2587 vinactive(vp, curthread); 2588 if (func != VPUTX_VUNREF) 2589 VOP_UNLOCK(vp, 0); 2590 } 2591 vdropl(vp); 2592 } 2593 2594 /* 2595 * Vnode put/release. 2596 * If count drops to zero, call inactive routine and return to freelist. 2597 */ 2598 void 2599 vrele(struct vnode *vp) 2600 { 2601 2602 vputx(vp, VPUTX_VRELE); 2603 } 2604 2605 /* 2606 * Release an already locked vnode. This give the same effects as 2607 * unlock+vrele(), but takes less time and avoids releasing and 2608 * re-aquiring the lock (as vrele() acquires the lock internally.) 2609 */ 2610 void 2611 vput(struct vnode *vp) 2612 { 2613 2614 vputx(vp, VPUTX_VPUT); 2615 } 2616 2617 /* 2618 * Release an exclusively locked vnode. Do not unlock the vnode lock. 2619 */ 2620 void 2621 vunref(struct vnode *vp) 2622 { 2623 2624 vputx(vp, VPUTX_VUNREF); 2625 } 2626 2627 /* 2628 * Increase the hold count and activate if this is the first reference. 2629 */ 2630 void 2631 _vhold(struct vnode *vp, bool locked) 2632 { 2633 struct mount *mp; 2634 2635 if (locked) 2636 ASSERT_VI_LOCKED(vp, __func__); 2637 else 2638 ASSERT_VI_UNLOCKED(vp, __func__); 2639 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2640 if (!locked && vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt)) { 2641 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2642 ("_vhold: vnode with holdcnt is free")); 2643 return; 2644 } 2645 2646 if (!locked) 2647 VI_LOCK(vp); 2648 if ((vp->v_iflag & VI_FREE) == 0) { 2649 refcount_acquire(&vp->v_holdcnt); 2650 if (!locked) 2651 VI_UNLOCK(vp); 2652 return; 2653 } 2654 VNASSERT(vp->v_holdcnt == 0, vp, 2655 ("%s: wrong hold count", __func__)); 2656 VNASSERT(vp->v_op != NULL, vp, 2657 ("%s: vnode already reclaimed.", __func__)); 2658 /* 2659 * Remove a vnode from the free list, mark it as in use, 2660 * and put it on the active list. 2661 */ 2662 mtx_lock(&vnode_free_list_mtx); 2663 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); 2664 freevnodes--; 2665 vp->v_iflag &= ~VI_FREE; 2666 KASSERT((vp->v_iflag & VI_ACTIVE) == 0, 2667 ("Activating already active vnode")); 2668 vp->v_iflag |= VI_ACTIVE; 2669 mp = vp->v_mount; 2670 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); 2671 mp->mnt_activevnodelistsize++; 2672 mtx_unlock(&vnode_free_list_mtx); 2673 refcount_acquire(&vp->v_holdcnt); 2674 if (!locked) 2675 VI_UNLOCK(vp); 2676 } 2677 2678 /* 2679 * Drop the hold count of the vnode. If this is the last reference to 2680 * the vnode we place it on the free list unless it has been vgone'd 2681 * (marked VI_DOOMED) in which case we will free it. 2682 * 2683 * Because the vnode vm object keeps a hold reference on the vnode if 2684 * there is at least one resident non-cached page, the vnode cannot 2685 * leave the active list without the page cleanup done. 2686 */ 2687 void 2688 _vdrop(struct vnode *vp, bool locked) 2689 { 2690 struct bufobj *bo; 2691 struct mount *mp; 2692 int active; 2693 2694 if (locked) 2695 ASSERT_VI_LOCKED(vp, __func__); 2696 else 2697 ASSERT_VI_UNLOCKED(vp, __func__); 2698 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2699 if ((int)vp->v_holdcnt <= 0) 2700 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2701 if (vfs_refcount_release_if_not_last(&vp->v_holdcnt)) { 2702 if (locked) 2703 VI_UNLOCK(vp); 2704 return; 2705 } 2706 2707 if (!locked) 2708 VI_LOCK(vp); 2709 if (refcount_release(&vp->v_holdcnt) == 0) { 2710 VI_UNLOCK(vp); 2711 return; 2712 } 2713 if ((vp->v_iflag & VI_DOOMED) == 0) { 2714 /* 2715 * Mark a vnode as free: remove it from its active list 2716 * and put it up for recycling on the freelist. 2717 */ 2718 VNASSERT(vp->v_op != NULL, vp, 2719 ("vdropl: vnode already reclaimed.")); 2720 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2721 ("vnode already free")); 2722 VNASSERT(vp->v_holdcnt == 0, vp, 2723 ("vdropl: freeing when we shouldn't")); 2724 active = vp->v_iflag & VI_ACTIVE; 2725 if ((vp->v_iflag & VI_OWEINACT) == 0) { 2726 vp->v_iflag &= ~VI_ACTIVE; 2727 mp = vp->v_mount; 2728 mtx_lock(&vnode_free_list_mtx); 2729 if (active) { 2730 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, 2731 v_actfreelist); 2732 mp->mnt_activevnodelistsize--; 2733 } 2734 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 2735 v_actfreelist); 2736 freevnodes++; 2737 vp->v_iflag |= VI_FREE; 2738 mtx_unlock(&vnode_free_list_mtx); 2739 } else { 2740 atomic_add_long(&free_owe_inact, 1); 2741 } 2742 VI_UNLOCK(vp); 2743 return; 2744 } 2745 /* 2746 * The vnode has been marked for destruction, so free it. 2747 * 2748 * The vnode will be returned to the zone where it will 2749 * normally remain until it is needed for another vnode. We 2750 * need to cleanup (or verify that the cleanup has already 2751 * been done) any residual data left from its current use 2752 * so as not to contaminate the freshly allocated vnode. 2753 */ 2754 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); 2755 atomic_subtract_long(&numvnodes, 1); 2756 bo = &vp->v_bufobj; 2757 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 2758 ("cleaned vnode still on the free list.")); 2759 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 2760 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 2761 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 2762 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 2763 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 2764 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 2765 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp, 2766 ("clean blk trie not empty")); 2767 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 2768 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, 2769 ("dirty blk trie not empty")); 2770 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 2771 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 2772 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 2773 VI_UNLOCK(vp); 2774 #ifdef MAC 2775 mac_vnode_destroy(vp); 2776 #endif 2777 if (vp->v_pollinfo != NULL) { 2778 destroy_vpollinfo(vp->v_pollinfo); 2779 vp->v_pollinfo = NULL; 2780 } 2781 #ifdef INVARIANTS 2782 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ 2783 vp->v_op = NULL; 2784 #endif 2785 bzero(&vp->v_un, sizeof(vp->v_un)); 2786 vp->v_iflag = 0; 2787 vp->v_vflag = 0; 2788 bo->bo_flag = 0; 2789 uma_zfree(vnode_zone, vp); 2790 } 2791 2792 /* 2793 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 2794 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 2795 * OWEINACT tracks whether a vnode missed a call to inactive due to a 2796 * failed lock upgrade. 2797 */ 2798 void 2799 vinactive(struct vnode *vp, struct thread *td) 2800 { 2801 struct vm_object *obj; 2802 2803 ASSERT_VOP_ELOCKED(vp, "vinactive"); 2804 ASSERT_VI_LOCKED(vp, "vinactive"); 2805 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 2806 ("vinactive: recursed on VI_DOINGINACT")); 2807 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2808 vp->v_iflag |= VI_DOINGINACT; 2809 vp->v_iflag &= ~VI_OWEINACT; 2810 VI_UNLOCK(vp); 2811 /* 2812 * Before moving off the active list, we must be sure that any 2813 * modified pages are converted into the vnode's dirty 2814 * buffers, since these will no longer be checked once the 2815 * vnode is on the inactive list. 2816 * 2817 * The write-out of the dirty pages is asynchronous. At the 2818 * point that VOP_INACTIVE() is called, there could still be 2819 * pending I/O and dirty pages in the object. 2820 */ 2821 obj = vp->v_object; 2822 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { 2823 VM_OBJECT_WLOCK(obj); 2824 vm_object_page_clean(obj, 0, 0, OBJPC_NOSYNC); 2825 VM_OBJECT_WUNLOCK(obj); 2826 } 2827 VOP_INACTIVE(vp, td); 2828 VI_LOCK(vp); 2829 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 2830 ("vinactive: lost VI_DOINGINACT")); 2831 vp->v_iflag &= ~VI_DOINGINACT; 2832 } 2833 2834 /* 2835 * Remove any vnodes in the vnode table belonging to mount point mp. 2836 * 2837 * If FORCECLOSE is not specified, there should not be any active ones, 2838 * return error if any are found (nb: this is a user error, not a 2839 * system error). If FORCECLOSE is specified, detach any active vnodes 2840 * that are found. 2841 * 2842 * If WRITECLOSE is set, only flush out regular file vnodes open for 2843 * writing. 2844 * 2845 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2846 * 2847 * `rootrefs' specifies the base reference count for the root vnode 2848 * of this filesystem. The root vnode is considered busy if its 2849 * v_usecount exceeds this value. On a successful return, vflush(, td) 2850 * will call vrele() on the root vnode exactly rootrefs times. 2851 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2852 * be zero. 2853 */ 2854 #ifdef DIAGNOSTIC 2855 static int busyprt = 0; /* print out busy vnodes */ 2856 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 2857 #endif 2858 2859 int 2860 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 2861 { 2862 struct vnode *vp, *mvp, *rootvp = NULL; 2863 struct vattr vattr; 2864 int busy = 0, error; 2865 2866 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 2867 rootrefs, flags); 2868 if (rootrefs > 0) { 2869 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2870 ("vflush: bad args")); 2871 /* 2872 * Get the filesystem root vnode. We can vput() it 2873 * immediately, since with rootrefs > 0, it won't go away. 2874 */ 2875 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 2876 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 2877 __func__, error); 2878 return (error); 2879 } 2880 vput(rootvp); 2881 } 2882 loop: 2883 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 2884 vholdl(vp); 2885 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 2886 if (error) { 2887 vdrop(vp); 2888 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 2889 goto loop; 2890 } 2891 /* 2892 * Skip over a vnodes marked VV_SYSTEM. 2893 */ 2894 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2895 VOP_UNLOCK(vp, 0); 2896 vdrop(vp); 2897 continue; 2898 } 2899 /* 2900 * If WRITECLOSE is set, flush out unlinked but still open 2901 * files (even if open only for reading) and regular file 2902 * vnodes open for writing. 2903 */ 2904 if (flags & WRITECLOSE) { 2905 if (vp->v_object != NULL) { 2906 VM_OBJECT_WLOCK(vp->v_object); 2907 vm_object_page_clean(vp->v_object, 0, 0, 0); 2908 VM_OBJECT_WUNLOCK(vp->v_object); 2909 } 2910 error = VOP_FSYNC(vp, MNT_WAIT, td); 2911 if (error != 0) { 2912 VOP_UNLOCK(vp, 0); 2913 vdrop(vp); 2914 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 2915 return (error); 2916 } 2917 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 2918 VI_LOCK(vp); 2919 2920 if ((vp->v_type == VNON || 2921 (error == 0 && vattr.va_nlink > 0)) && 2922 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2923 VOP_UNLOCK(vp, 0); 2924 vdropl(vp); 2925 continue; 2926 } 2927 } else 2928 VI_LOCK(vp); 2929 /* 2930 * With v_usecount == 0, all we need to do is clear out the 2931 * vnode data structures and we are done. 2932 * 2933 * If FORCECLOSE is set, forcibly close the vnode. 2934 */ 2935 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 2936 vgonel(vp); 2937 } else { 2938 busy++; 2939 #ifdef DIAGNOSTIC 2940 if (busyprt) 2941 vprint("vflush: busy vnode", vp); 2942 #endif 2943 } 2944 VOP_UNLOCK(vp, 0); 2945 vdropl(vp); 2946 } 2947 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2948 /* 2949 * If just the root vnode is busy, and if its refcount 2950 * is equal to `rootrefs', then go ahead and kill it. 2951 */ 2952 VI_LOCK(rootvp); 2953 KASSERT(busy > 0, ("vflush: not busy")); 2954 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 2955 ("vflush: usecount %d < rootrefs %d", 2956 rootvp->v_usecount, rootrefs)); 2957 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2958 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 2959 vgone(rootvp); 2960 VOP_UNLOCK(rootvp, 0); 2961 busy = 0; 2962 } else 2963 VI_UNLOCK(rootvp); 2964 } 2965 if (busy) { 2966 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 2967 busy); 2968 return (EBUSY); 2969 } 2970 for (; rootrefs > 0; rootrefs--) 2971 vrele(rootvp); 2972 return (0); 2973 } 2974 2975 /* 2976 * Recycle an unused vnode to the front of the free list. 2977 */ 2978 int 2979 vrecycle(struct vnode *vp) 2980 { 2981 int recycled; 2982 2983 ASSERT_VOP_ELOCKED(vp, "vrecycle"); 2984 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2985 recycled = 0; 2986 VI_LOCK(vp); 2987 if (vp->v_usecount == 0) { 2988 recycled = 1; 2989 vgonel(vp); 2990 } 2991 VI_UNLOCK(vp); 2992 return (recycled); 2993 } 2994 2995 /* 2996 * Eliminate all activity associated with a vnode 2997 * in preparation for reuse. 2998 */ 2999 void 3000 vgone(struct vnode *vp) 3001 { 3002 VI_LOCK(vp); 3003 vgonel(vp); 3004 VI_UNLOCK(vp); 3005 } 3006 3007 static void 3008 notify_lowervp_vfs_dummy(struct mount *mp __unused, 3009 struct vnode *lowervp __unused) 3010 { 3011 } 3012 3013 /* 3014 * Notify upper mounts about reclaimed or unlinked vnode. 3015 */ 3016 void 3017 vfs_notify_upper(struct vnode *vp, int event) 3018 { 3019 static struct vfsops vgonel_vfsops = { 3020 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, 3021 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, 3022 }; 3023 struct mount *mp, *ump, *mmp; 3024 3025 mp = vp->v_mount; 3026 if (mp == NULL) 3027 return; 3028 3029 MNT_ILOCK(mp); 3030 if (TAILQ_EMPTY(&mp->mnt_uppers)) 3031 goto unlock; 3032 MNT_IUNLOCK(mp); 3033 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); 3034 mmp->mnt_op = &vgonel_vfsops; 3035 mmp->mnt_kern_flag |= MNTK_MARKER; 3036 MNT_ILOCK(mp); 3037 mp->mnt_kern_flag |= MNTK_VGONE_UPPER; 3038 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { 3039 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { 3040 ump = TAILQ_NEXT(ump, mnt_upper_link); 3041 continue; 3042 } 3043 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); 3044 MNT_IUNLOCK(mp); 3045 switch (event) { 3046 case VFS_NOTIFY_UPPER_RECLAIM: 3047 VFS_RECLAIM_LOWERVP(ump, vp); 3048 break; 3049 case VFS_NOTIFY_UPPER_UNLINK: 3050 VFS_UNLINK_LOWERVP(ump, vp); 3051 break; 3052 default: 3053 KASSERT(0, ("invalid event %d", event)); 3054 break; 3055 } 3056 MNT_ILOCK(mp); 3057 ump = TAILQ_NEXT(mmp, mnt_upper_link); 3058 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); 3059 } 3060 free(mmp, M_TEMP); 3061 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; 3062 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { 3063 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; 3064 wakeup(&mp->mnt_uppers); 3065 } 3066 unlock: 3067 MNT_IUNLOCK(mp); 3068 } 3069 3070 /* 3071 * vgone, with the vp interlock held. 3072 */ 3073 static void 3074 vgonel(struct vnode *vp) 3075 { 3076 struct thread *td; 3077 int oweinact; 3078 int active; 3079 struct mount *mp; 3080 3081 ASSERT_VOP_ELOCKED(vp, "vgonel"); 3082 ASSERT_VI_LOCKED(vp, "vgonel"); 3083 VNASSERT(vp->v_holdcnt, vp, 3084 ("vgonel: vp %p has no reference.", vp)); 3085 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3086 td = curthread; 3087 3088 /* 3089 * Don't vgonel if we're already doomed. 3090 */ 3091 if (vp->v_iflag & VI_DOOMED) 3092 return; 3093 vp->v_iflag |= VI_DOOMED; 3094 3095 /* 3096 * Check to see if the vnode is in use. If so, we have to call 3097 * VOP_CLOSE() and VOP_INACTIVE(). 3098 */ 3099 active = vp->v_usecount; 3100 oweinact = (vp->v_iflag & VI_OWEINACT); 3101 VI_UNLOCK(vp); 3102 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); 3103 3104 /* 3105 * If purging an active vnode, it must be closed and 3106 * deactivated before being reclaimed. 3107 */ 3108 if (active) 3109 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 3110 if (oweinact || active) { 3111 VI_LOCK(vp); 3112 if ((vp->v_iflag & VI_DOINGINACT) == 0) 3113 vinactive(vp, td); 3114 VI_UNLOCK(vp); 3115 } 3116 if (vp->v_type == VSOCK) 3117 vfs_unp_reclaim(vp); 3118 3119 /* 3120 * Clean out any buffers associated with the vnode. 3121 * If the flush fails, just toss the buffers. 3122 */ 3123 mp = NULL; 3124 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 3125 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 3126 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { 3127 while (vinvalbuf(vp, 0, 0, 0) != 0) 3128 ; 3129 } 3130 3131 BO_LOCK(&vp->v_bufobj); 3132 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && 3133 vp->v_bufobj.bo_dirty.bv_cnt == 0 && 3134 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && 3135 vp->v_bufobj.bo_clean.bv_cnt == 0, 3136 ("vp %p bufobj not invalidated", vp)); 3137 vp->v_bufobj.bo_flag |= BO_DEAD; 3138 BO_UNLOCK(&vp->v_bufobj); 3139 3140 /* 3141 * Reclaim the vnode. 3142 */ 3143 if (VOP_RECLAIM(vp, td)) 3144 panic("vgone: cannot reclaim"); 3145 if (mp != NULL) 3146 vn_finished_secondary_write(mp); 3147 VNASSERT(vp->v_object == NULL, vp, 3148 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 3149 /* 3150 * Clear the advisory locks and wake up waiting threads. 3151 */ 3152 (void)VOP_ADVLOCKPURGE(vp); 3153 vp->v_lockf = NULL; 3154 /* 3155 * Delete from old mount point vnode list. 3156 */ 3157 delmntque(vp); 3158 cache_purge(vp); 3159 /* 3160 * Done with purge, reset to the standard lock and invalidate 3161 * the vnode. 3162 */ 3163 VI_LOCK(vp); 3164 vp->v_vnlock = &vp->v_lock; 3165 vp->v_op = &dead_vnodeops; 3166 vp->v_tag = "none"; 3167 vp->v_type = VBAD; 3168 } 3169 3170 /* 3171 * Calculate the total number of references to a special device. 3172 */ 3173 int 3174 vcount(struct vnode *vp) 3175 { 3176 int count; 3177 3178 dev_lock(); 3179 count = vp->v_rdev->si_usecount; 3180 dev_unlock(); 3181 return (count); 3182 } 3183 3184 /* 3185 * Same as above, but using the struct cdev *as argument 3186 */ 3187 int 3188 count_dev(struct cdev *dev) 3189 { 3190 int count; 3191 3192 dev_lock(); 3193 count = dev->si_usecount; 3194 dev_unlock(); 3195 return(count); 3196 } 3197 3198 /* 3199 * Print out a description of a vnode. 3200 */ 3201 static char *typename[] = 3202 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 3203 "VMARKER"}; 3204 3205 void 3206 vn_printf(struct vnode *vp, const char *fmt, ...) 3207 { 3208 va_list ap; 3209 char buf[256], buf2[16]; 3210 u_long flags; 3211 3212 va_start(ap, fmt); 3213 vprintf(fmt, ap); 3214 va_end(ap); 3215 printf("%p: ", (void *)vp); 3216 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 3217 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 3218 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 3219 buf[0] = '\0'; 3220 buf[1] = '\0'; 3221 if (vp->v_vflag & VV_ROOT) 3222 strlcat(buf, "|VV_ROOT", sizeof(buf)); 3223 if (vp->v_vflag & VV_ISTTY) 3224 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 3225 if (vp->v_vflag & VV_NOSYNC) 3226 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 3227 if (vp->v_vflag & VV_ETERNALDEV) 3228 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); 3229 if (vp->v_vflag & VV_CACHEDLABEL) 3230 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 3231 if (vp->v_vflag & VV_TEXT) 3232 strlcat(buf, "|VV_TEXT", sizeof(buf)); 3233 if (vp->v_vflag & VV_COPYONWRITE) 3234 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 3235 if (vp->v_vflag & VV_SYSTEM) 3236 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 3237 if (vp->v_vflag & VV_PROCDEP) 3238 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 3239 if (vp->v_vflag & VV_NOKNOTE) 3240 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 3241 if (vp->v_vflag & VV_DELETED) 3242 strlcat(buf, "|VV_DELETED", sizeof(buf)); 3243 if (vp->v_vflag & VV_MD) 3244 strlcat(buf, "|VV_MD", sizeof(buf)); 3245 if (vp->v_vflag & VV_FORCEINSMQ) 3246 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); 3247 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | 3248 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 3249 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); 3250 if (flags != 0) { 3251 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 3252 strlcat(buf, buf2, sizeof(buf)); 3253 } 3254 if (vp->v_iflag & VI_MOUNT) 3255 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 3256 if (vp->v_iflag & VI_DOOMED) 3257 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 3258 if (vp->v_iflag & VI_FREE) 3259 strlcat(buf, "|VI_FREE", sizeof(buf)); 3260 if (vp->v_iflag & VI_ACTIVE) 3261 strlcat(buf, "|VI_ACTIVE", sizeof(buf)); 3262 if (vp->v_iflag & VI_DOINGINACT) 3263 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 3264 if (vp->v_iflag & VI_OWEINACT) 3265 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 3266 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | 3267 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT); 3268 if (flags != 0) { 3269 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 3270 strlcat(buf, buf2, sizeof(buf)); 3271 } 3272 printf(" flags (%s)\n", buf + 1); 3273 if (mtx_owned(VI_MTX(vp))) 3274 printf(" VI_LOCKed"); 3275 if (vp->v_object != NULL) 3276 printf(" v_object %p ref %d pages %d " 3277 "cleanbuf %d dirtybuf %d\n", 3278 vp->v_object, vp->v_object->ref_count, 3279 vp->v_object->resident_page_count, 3280 vp->v_bufobj.bo_clean.bv_cnt, 3281 vp->v_bufobj.bo_dirty.bv_cnt); 3282 printf(" "); 3283 lockmgr_printinfo(vp->v_vnlock); 3284 if (vp->v_data != NULL) 3285 VOP_PRINT(vp); 3286 } 3287 3288 #ifdef DDB 3289 /* 3290 * List all of the locked vnodes in the system. 3291 * Called when debugging the kernel. 3292 */ 3293 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 3294 { 3295 struct mount *mp; 3296 struct vnode *vp; 3297 3298 /* 3299 * Note: because this is DDB, we can't obey the locking semantics 3300 * for these structures, which means we could catch an inconsistent 3301 * state and dereference a nasty pointer. Not much to be done 3302 * about that. 3303 */ 3304 db_printf("Locked vnodes\n"); 3305 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3306 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3307 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) 3308 vprint("", vp); 3309 } 3310 } 3311 } 3312 3313 /* 3314 * Show details about the given vnode. 3315 */ 3316 DB_SHOW_COMMAND(vnode, db_show_vnode) 3317 { 3318 struct vnode *vp; 3319 3320 if (!have_addr) 3321 return; 3322 vp = (struct vnode *)addr; 3323 vn_printf(vp, "vnode "); 3324 } 3325 3326 /* 3327 * Show details about the given mount point. 3328 */ 3329 DB_SHOW_COMMAND(mount, db_show_mount) 3330 { 3331 struct mount *mp; 3332 struct vfsopt *opt; 3333 struct statfs *sp; 3334 struct vnode *vp; 3335 char buf[512]; 3336 uint64_t mflags; 3337 u_int flags; 3338 3339 if (!have_addr) { 3340 /* No address given, print short info about all mount points. */ 3341 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3342 db_printf("%p %s on %s (%s)\n", mp, 3343 mp->mnt_stat.f_mntfromname, 3344 mp->mnt_stat.f_mntonname, 3345 mp->mnt_stat.f_fstypename); 3346 if (db_pager_quit) 3347 break; 3348 } 3349 db_printf("\nMore info: show mount <addr>\n"); 3350 return; 3351 } 3352 3353 mp = (struct mount *)addr; 3354 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 3355 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 3356 3357 buf[0] = '\0'; 3358 mflags = mp->mnt_flag; 3359 #define MNT_FLAG(flag) do { \ 3360 if (mflags & (flag)) { \ 3361 if (buf[0] != '\0') \ 3362 strlcat(buf, ", ", sizeof(buf)); \ 3363 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 3364 mflags &= ~(flag); \ 3365 } \ 3366 } while (0) 3367 MNT_FLAG(MNT_RDONLY); 3368 MNT_FLAG(MNT_SYNCHRONOUS); 3369 MNT_FLAG(MNT_NOEXEC); 3370 MNT_FLAG(MNT_NOSUID); 3371 MNT_FLAG(MNT_NFS4ACLS); 3372 MNT_FLAG(MNT_UNION); 3373 MNT_FLAG(MNT_ASYNC); 3374 MNT_FLAG(MNT_SUIDDIR); 3375 MNT_FLAG(MNT_SOFTDEP); 3376 MNT_FLAG(MNT_NOSYMFOLLOW); 3377 MNT_FLAG(MNT_GJOURNAL); 3378 MNT_FLAG(MNT_MULTILABEL); 3379 MNT_FLAG(MNT_ACLS); 3380 MNT_FLAG(MNT_NOATIME); 3381 MNT_FLAG(MNT_NOCLUSTERR); 3382 MNT_FLAG(MNT_NOCLUSTERW); 3383 MNT_FLAG(MNT_SUJ); 3384 MNT_FLAG(MNT_EXRDONLY); 3385 MNT_FLAG(MNT_EXPORTED); 3386 MNT_FLAG(MNT_DEFEXPORTED); 3387 MNT_FLAG(MNT_EXPORTANON); 3388 MNT_FLAG(MNT_EXKERB); 3389 MNT_FLAG(MNT_EXPUBLIC); 3390 MNT_FLAG(MNT_LOCAL); 3391 MNT_FLAG(MNT_QUOTA); 3392 MNT_FLAG(MNT_ROOTFS); 3393 MNT_FLAG(MNT_USER); 3394 MNT_FLAG(MNT_IGNORE); 3395 MNT_FLAG(MNT_UPDATE); 3396 MNT_FLAG(MNT_DELEXPORT); 3397 MNT_FLAG(MNT_RELOAD); 3398 MNT_FLAG(MNT_FORCE); 3399 MNT_FLAG(MNT_SNAPSHOT); 3400 MNT_FLAG(MNT_BYFSID); 3401 #undef MNT_FLAG 3402 if (mflags != 0) { 3403 if (buf[0] != '\0') 3404 strlcat(buf, ", ", sizeof(buf)); 3405 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3406 "0x%016jx", mflags); 3407 } 3408 db_printf(" mnt_flag = %s\n", buf); 3409 3410 buf[0] = '\0'; 3411 flags = mp->mnt_kern_flag; 3412 #define MNT_KERN_FLAG(flag) do { \ 3413 if (flags & (flag)) { \ 3414 if (buf[0] != '\0') \ 3415 strlcat(buf, ", ", sizeof(buf)); \ 3416 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 3417 flags &= ~(flag); \ 3418 } \ 3419 } while (0) 3420 MNT_KERN_FLAG(MNTK_UNMOUNTF); 3421 MNT_KERN_FLAG(MNTK_ASYNC); 3422 MNT_KERN_FLAG(MNTK_SOFTDEP); 3423 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 3424 MNT_KERN_FLAG(MNTK_DRAINING); 3425 MNT_KERN_FLAG(MNTK_REFEXPIRE); 3426 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 3427 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 3428 MNT_KERN_FLAG(MNTK_NO_IOPF); 3429 MNT_KERN_FLAG(MNTK_VGONE_UPPER); 3430 MNT_KERN_FLAG(MNTK_VGONE_WAITER); 3431 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); 3432 MNT_KERN_FLAG(MNTK_MARKER); 3433 MNT_KERN_FLAG(MNTK_USES_BCACHE); 3434 MNT_KERN_FLAG(MNTK_NOASYNC); 3435 MNT_KERN_FLAG(MNTK_UNMOUNT); 3436 MNT_KERN_FLAG(MNTK_MWAIT); 3437 MNT_KERN_FLAG(MNTK_SUSPEND); 3438 MNT_KERN_FLAG(MNTK_SUSPEND2); 3439 MNT_KERN_FLAG(MNTK_SUSPENDED); 3440 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 3441 MNT_KERN_FLAG(MNTK_NOKNOTE); 3442 #undef MNT_KERN_FLAG 3443 if (flags != 0) { 3444 if (buf[0] != '\0') 3445 strlcat(buf, ", ", sizeof(buf)); 3446 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 3447 "0x%08x", flags); 3448 } 3449 db_printf(" mnt_kern_flag = %s\n", buf); 3450 3451 db_printf(" mnt_opt = "); 3452 opt = TAILQ_FIRST(mp->mnt_opt); 3453 if (opt != NULL) { 3454 db_printf("%s", opt->name); 3455 opt = TAILQ_NEXT(opt, link); 3456 while (opt != NULL) { 3457 db_printf(", %s", opt->name); 3458 opt = TAILQ_NEXT(opt, link); 3459 } 3460 } 3461 db_printf("\n"); 3462 3463 sp = &mp->mnt_stat; 3464 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 3465 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 3466 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 3467 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 3468 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 3469 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 3470 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 3471 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 3472 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 3473 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 3474 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 3475 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 3476 3477 db_printf(" mnt_cred = { uid=%u ruid=%u", 3478 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 3479 if (jailed(mp->mnt_cred)) 3480 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 3481 db_printf(" }\n"); 3482 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 3483 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 3484 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 3485 db_printf(" mnt_activevnodelistsize = %d\n", 3486 mp->mnt_activevnodelistsize); 3487 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 3488 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 3489 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 3490 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 3491 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); 3492 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 3493 db_printf(" mnt_secondary_accwrites = %d\n", 3494 mp->mnt_secondary_accwrites); 3495 db_printf(" mnt_gjprovider = %s\n", 3496 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 3497 3498 db_printf("\n\nList of active vnodes\n"); 3499 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { 3500 if (vp->v_type != VMARKER) { 3501 vn_printf(vp, "vnode "); 3502 if (db_pager_quit) 3503 break; 3504 } 3505 } 3506 db_printf("\n\nList of inactive vnodes\n"); 3507 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3508 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { 3509 vn_printf(vp, "vnode "); 3510 if (db_pager_quit) 3511 break; 3512 } 3513 } 3514 } 3515 #endif /* DDB */ 3516 3517 /* 3518 * Fill in a struct xvfsconf based on a struct vfsconf. 3519 */ 3520 static int 3521 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) 3522 { 3523 struct xvfsconf xvfsp; 3524 3525 bzero(&xvfsp, sizeof(xvfsp)); 3526 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3527 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3528 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3529 xvfsp.vfc_flags = vfsp->vfc_flags; 3530 /* 3531 * These are unused in userland, we keep them 3532 * to not break binary compatibility. 3533 */ 3534 xvfsp.vfc_vfsops = NULL; 3535 xvfsp.vfc_next = NULL; 3536 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3537 } 3538 3539 #ifdef COMPAT_FREEBSD32 3540 struct xvfsconf32 { 3541 uint32_t vfc_vfsops; 3542 char vfc_name[MFSNAMELEN]; 3543 int32_t vfc_typenum; 3544 int32_t vfc_refcount; 3545 int32_t vfc_flags; 3546 uint32_t vfc_next; 3547 }; 3548 3549 static int 3550 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) 3551 { 3552 struct xvfsconf32 xvfsp; 3553 3554 strcpy(xvfsp.vfc_name, vfsp->vfc_name); 3555 xvfsp.vfc_typenum = vfsp->vfc_typenum; 3556 xvfsp.vfc_refcount = vfsp->vfc_refcount; 3557 xvfsp.vfc_flags = vfsp->vfc_flags; 3558 xvfsp.vfc_vfsops = 0; 3559 xvfsp.vfc_next = 0; 3560 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3561 } 3562 #endif 3563 3564 /* 3565 * Top level filesystem related information gathering. 3566 */ 3567 static int 3568 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3569 { 3570 struct vfsconf *vfsp; 3571 int error; 3572 3573 error = 0; 3574 vfsconf_slock(); 3575 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3576 #ifdef COMPAT_FREEBSD32 3577 if (req->flags & SCTL_MASK32) 3578 error = vfsconf2x32(req, vfsp); 3579 else 3580 #endif 3581 error = vfsconf2x(req, vfsp); 3582 if (error) 3583 break; 3584 } 3585 vfsconf_sunlock(); 3586 return (error); 3587 } 3588 3589 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | 3590 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist, 3591 "S,xvfsconf", "List of all configured filesystems"); 3592 3593 #ifndef BURN_BRIDGES 3594 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3595 3596 static int 3597 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3598 { 3599 int *name = (int *)arg1 - 1; /* XXX */ 3600 u_int namelen = arg2 + 1; /* XXX */ 3601 struct vfsconf *vfsp; 3602 3603 log(LOG_WARNING, "userland calling deprecated sysctl, " 3604 "please rebuild world\n"); 3605 3606 #if 1 || defined(COMPAT_PRELITE2) 3607 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3608 if (namelen == 1) 3609 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3610 #endif 3611 3612 switch (name[1]) { 3613 case VFS_MAXTYPENUM: 3614 if (namelen != 2) 3615 return (ENOTDIR); 3616 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3617 case VFS_CONF: 3618 if (namelen != 3) 3619 return (ENOTDIR); /* overloaded */ 3620 vfsconf_slock(); 3621 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3622 if (vfsp->vfc_typenum == name[2]) 3623 break; 3624 } 3625 vfsconf_sunlock(); 3626 if (vfsp == NULL) 3627 return (EOPNOTSUPP); 3628 #ifdef COMPAT_FREEBSD32 3629 if (req->flags & SCTL_MASK32) 3630 return (vfsconf2x32(req, vfsp)); 3631 else 3632 #endif 3633 return (vfsconf2x(req, vfsp)); 3634 } 3635 return (EOPNOTSUPP); 3636 } 3637 3638 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | 3639 CTLFLAG_MPSAFE, vfs_sysctl, 3640 "Generic filesystem"); 3641 3642 #if 1 || defined(COMPAT_PRELITE2) 3643 3644 static int 3645 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3646 { 3647 int error; 3648 struct vfsconf *vfsp; 3649 struct ovfsconf ovfs; 3650 3651 vfsconf_slock(); 3652 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3653 bzero(&ovfs, sizeof(ovfs)); 3654 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3655 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3656 ovfs.vfc_index = vfsp->vfc_typenum; 3657 ovfs.vfc_refcount = vfsp->vfc_refcount; 3658 ovfs.vfc_flags = vfsp->vfc_flags; 3659 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3660 if (error != 0) { 3661 vfsconf_sunlock(); 3662 return (error); 3663 } 3664 } 3665 vfsconf_sunlock(); 3666 return (0); 3667 } 3668 3669 #endif /* 1 || COMPAT_PRELITE2 */ 3670 #endif /* !BURN_BRIDGES */ 3671 3672 #define KINFO_VNODESLOP 10 3673 #ifdef notyet 3674 /* 3675 * Dump vnode list (via sysctl). 3676 */ 3677 /* ARGSUSED */ 3678 static int 3679 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3680 { 3681 struct xvnode *xvn; 3682 struct mount *mp; 3683 struct vnode *vp; 3684 int error, len, n; 3685 3686 /* 3687 * Stale numvnodes access is not fatal here. 3688 */ 3689 req->lock = 0; 3690 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3691 if (!req->oldptr) 3692 /* Make an estimate */ 3693 return (SYSCTL_OUT(req, 0, len)); 3694 3695 error = sysctl_wire_old_buffer(req, 0); 3696 if (error != 0) 3697 return (error); 3698 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3699 n = 0; 3700 mtx_lock(&mountlist_mtx); 3701 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3702 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 3703 continue; 3704 MNT_ILOCK(mp); 3705 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3706 if (n == len) 3707 break; 3708 vref(vp); 3709 xvn[n].xv_size = sizeof *xvn; 3710 xvn[n].xv_vnode = vp; 3711 xvn[n].xv_id = 0; /* XXX compat */ 3712 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3713 XV_COPY(usecount); 3714 XV_COPY(writecount); 3715 XV_COPY(holdcnt); 3716 XV_COPY(mount); 3717 XV_COPY(numoutput); 3718 XV_COPY(type); 3719 #undef XV_COPY 3720 xvn[n].xv_flag = vp->v_vflag; 3721 3722 switch (vp->v_type) { 3723 case VREG: 3724 case VDIR: 3725 case VLNK: 3726 break; 3727 case VBLK: 3728 case VCHR: 3729 if (vp->v_rdev == NULL) { 3730 vrele(vp); 3731 continue; 3732 } 3733 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3734 break; 3735 case VSOCK: 3736 xvn[n].xv_socket = vp->v_socket; 3737 break; 3738 case VFIFO: 3739 xvn[n].xv_fifo = vp->v_fifoinfo; 3740 break; 3741 case VNON: 3742 case VBAD: 3743 default: 3744 /* shouldn't happen? */ 3745 vrele(vp); 3746 continue; 3747 } 3748 vrele(vp); 3749 ++n; 3750 } 3751 MNT_IUNLOCK(mp); 3752 mtx_lock(&mountlist_mtx); 3753 vfs_unbusy(mp); 3754 if (n == len) 3755 break; 3756 } 3757 mtx_unlock(&mountlist_mtx); 3758 3759 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3760 free(xvn, M_TEMP); 3761 return (error); 3762 } 3763 3764 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD | 3765 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", 3766 ""); 3767 #endif 3768 3769 static void 3770 unmount_or_warn(struct mount *mp) 3771 { 3772 int error; 3773 3774 error = dounmount(mp, MNT_FORCE, curthread); 3775 if (error != 0) { 3776 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 3777 if (error == EBUSY) 3778 printf("BUSY)\n"); 3779 else 3780 printf("%d)\n", error); 3781 } 3782 } 3783 3784 /* 3785 * Unmount all filesystems. The list is traversed in reverse order 3786 * of mounting to avoid dependencies. 3787 */ 3788 void 3789 vfs_unmountall(void) 3790 { 3791 struct mount *mp, *tmp; 3792 3793 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 3794 3795 /* 3796 * Since this only runs when rebooting, it is not interlocked. 3797 */ 3798 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { 3799 vfs_ref(mp); 3800 3801 /* 3802 * Forcibly unmounting "/dev" before "/" would prevent clean 3803 * unmount of the latter. 3804 */ 3805 if (mp == rootdevmp) 3806 continue; 3807 3808 unmount_or_warn(mp); 3809 } 3810 3811 if (rootdevmp != NULL) 3812 unmount_or_warn(rootdevmp); 3813 } 3814 3815 /* 3816 * perform msync on all vnodes under a mount point 3817 * the mount point must be locked. 3818 */ 3819 void 3820 vfs_msync(struct mount *mp, int flags) 3821 { 3822 struct vnode *vp, *mvp; 3823 struct vm_object *obj; 3824 3825 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 3826 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { 3827 obj = vp->v_object; 3828 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 3829 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 3830 if (!vget(vp, 3831 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3832 curthread)) { 3833 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3834 vput(vp); 3835 continue; 3836 } 3837 3838 obj = vp->v_object; 3839 if (obj != NULL) { 3840 VM_OBJECT_WLOCK(obj); 3841 vm_object_page_clean(obj, 0, 0, 3842 flags == MNT_WAIT ? 3843 OBJPC_SYNC : OBJPC_NOSYNC); 3844 VM_OBJECT_WUNLOCK(obj); 3845 } 3846 vput(vp); 3847 } 3848 } else 3849 VI_UNLOCK(vp); 3850 } 3851 } 3852 3853 static void 3854 destroy_vpollinfo_free(struct vpollinfo *vi) 3855 { 3856 3857 knlist_destroy(&vi->vpi_selinfo.si_note); 3858 mtx_destroy(&vi->vpi_lock); 3859 uma_zfree(vnodepoll_zone, vi); 3860 } 3861 3862 static void 3863 destroy_vpollinfo(struct vpollinfo *vi) 3864 { 3865 3866 knlist_clear(&vi->vpi_selinfo.si_note, 1); 3867 seldrain(&vi->vpi_selinfo); 3868 destroy_vpollinfo_free(vi); 3869 } 3870 3871 /* 3872 * Initalize per-vnode helper structure to hold poll-related state. 3873 */ 3874 void 3875 v_addpollinfo(struct vnode *vp) 3876 { 3877 struct vpollinfo *vi; 3878 3879 if (vp->v_pollinfo != NULL) 3880 return; 3881 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); 3882 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3883 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 3884 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 3885 VI_LOCK(vp); 3886 if (vp->v_pollinfo != NULL) { 3887 VI_UNLOCK(vp); 3888 destroy_vpollinfo_free(vi); 3889 return; 3890 } 3891 vp->v_pollinfo = vi; 3892 VI_UNLOCK(vp); 3893 } 3894 3895 /* 3896 * Record a process's interest in events which might happen to 3897 * a vnode. Because poll uses the historic select-style interface 3898 * internally, this routine serves as both the ``check for any 3899 * pending events'' and the ``record my interest in future events'' 3900 * functions. (These are done together, while the lock is held, 3901 * to avoid race conditions.) 3902 */ 3903 int 3904 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 3905 { 3906 3907 v_addpollinfo(vp); 3908 mtx_lock(&vp->v_pollinfo->vpi_lock); 3909 if (vp->v_pollinfo->vpi_revents & events) { 3910 /* 3911 * This leaves events we are not interested 3912 * in available for the other process which 3913 * which presumably had requested them 3914 * (otherwise they would never have been 3915 * recorded). 3916 */ 3917 events &= vp->v_pollinfo->vpi_revents; 3918 vp->v_pollinfo->vpi_revents &= ~events; 3919 3920 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3921 return (events); 3922 } 3923 vp->v_pollinfo->vpi_events |= events; 3924 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3925 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3926 return (0); 3927 } 3928 3929 /* 3930 * Routine to create and manage a filesystem syncer vnode. 3931 */ 3932 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3933 static int sync_fsync(struct vop_fsync_args *); 3934 static int sync_inactive(struct vop_inactive_args *); 3935 static int sync_reclaim(struct vop_reclaim_args *); 3936 3937 static struct vop_vector sync_vnodeops = { 3938 .vop_bypass = VOP_EOPNOTSUPP, 3939 .vop_close = sync_close, /* close */ 3940 .vop_fsync = sync_fsync, /* fsync */ 3941 .vop_inactive = sync_inactive, /* inactive */ 3942 .vop_reclaim = sync_reclaim, /* reclaim */ 3943 .vop_lock1 = vop_stdlock, /* lock */ 3944 .vop_unlock = vop_stdunlock, /* unlock */ 3945 .vop_islocked = vop_stdislocked, /* islocked */ 3946 }; 3947 3948 /* 3949 * Create a new filesystem syncer vnode for the specified mount point. 3950 */ 3951 void 3952 vfs_allocate_syncvnode(struct mount *mp) 3953 { 3954 struct vnode *vp; 3955 struct bufobj *bo; 3956 static long start, incr, next; 3957 int error; 3958 3959 /* Allocate a new vnode */ 3960 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 3961 if (error != 0) 3962 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 3963 vp->v_type = VNON; 3964 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3965 vp->v_vflag |= VV_FORCEINSMQ; 3966 error = insmntque(vp, mp); 3967 if (error != 0) 3968 panic("vfs_allocate_syncvnode: insmntque() failed"); 3969 vp->v_vflag &= ~VV_FORCEINSMQ; 3970 VOP_UNLOCK(vp, 0); 3971 /* 3972 * Place the vnode onto the syncer worklist. We attempt to 3973 * scatter them about on the list so that they will go off 3974 * at evenly distributed times even if all the filesystems 3975 * are mounted at once. 3976 */ 3977 next += incr; 3978 if (next == 0 || next > syncer_maxdelay) { 3979 start /= 2; 3980 incr /= 2; 3981 if (start == 0) { 3982 start = syncer_maxdelay / 2; 3983 incr = syncer_maxdelay; 3984 } 3985 next = start; 3986 } 3987 bo = &vp->v_bufobj; 3988 BO_LOCK(bo); 3989 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 3990 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 3991 mtx_lock(&sync_mtx); 3992 sync_vnode_count++; 3993 if (mp->mnt_syncer == NULL) { 3994 mp->mnt_syncer = vp; 3995 vp = NULL; 3996 } 3997 mtx_unlock(&sync_mtx); 3998 BO_UNLOCK(bo); 3999 if (vp != NULL) { 4000 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4001 vgone(vp); 4002 vput(vp); 4003 } 4004 } 4005 4006 void 4007 vfs_deallocate_syncvnode(struct mount *mp) 4008 { 4009 struct vnode *vp; 4010 4011 mtx_lock(&sync_mtx); 4012 vp = mp->mnt_syncer; 4013 if (vp != NULL) 4014 mp->mnt_syncer = NULL; 4015 mtx_unlock(&sync_mtx); 4016 if (vp != NULL) 4017 vrele(vp); 4018 } 4019 4020 /* 4021 * Do a lazy sync of the filesystem. 4022 */ 4023 static int 4024 sync_fsync(struct vop_fsync_args *ap) 4025 { 4026 struct vnode *syncvp = ap->a_vp; 4027 struct mount *mp = syncvp->v_mount; 4028 int error, save; 4029 struct bufobj *bo; 4030 4031 /* 4032 * We only need to do something if this is a lazy evaluation. 4033 */ 4034 if (ap->a_waitfor != MNT_LAZY) 4035 return (0); 4036 4037 /* 4038 * Move ourselves to the back of the sync list. 4039 */ 4040 bo = &syncvp->v_bufobj; 4041 BO_LOCK(bo); 4042 vn_syncer_add_to_worklist(bo, syncdelay); 4043 BO_UNLOCK(bo); 4044 4045 /* 4046 * Walk the list of vnodes pushing all that are dirty and 4047 * not already on the sync list. 4048 */ 4049 if (vfs_busy(mp, MBF_NOWAIT) != 0) 4050 return (0); 4051 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 4052 vfs_unbusy(mp); 4053 return (0); 4054 } 4055 save = curthread_pflags_set(TDP_SYNCIO); 4056 vfs_msync(mp, MNT_NOWAIT); 4057 error = VFS_SYNC(mp, MNT_LAZY); 4058 curthread_pflags_restore(save); 4059 vn_finished_write(mp); 4060 vfs_unbusy(mp); 4061 return (error); 4062 } 4063 4064 /* 4065 * The syncer vnode is no referenced. 4066 */ 4067 static int 4068 sync_inactive(struct vop_inactive_args *ap) 4069 { 4070 4071 vgone(ap->a_vp); 4072 return (0); 4073 } 4074 4075 /* 4076 * The syncer vnode is no longer needed and is being decommissioned. 4077 * 4078 * Modifications to the worklist must be protected by sync_mtx. 4079 */ 4080 static int 4081 sync_reclaim(struct vop_reclaim_args *ap) 4082 { 4083 struct vnode *vp = ap->a_vp; 4084 struct bufobj *bo; 4085 4086 bo = &vp->v_bufobj; 4087 BO_LOCK(bo); 4088 mtx_lock(&sync_mtx); 4089 if (vp->v_mount->mnt_syncer == vp) 4090 vp->v_mount->mnt_syncer = NULL; 4091 if (bo->bo_flag & BO_ONWORKLST) { 4092 LIST_REMOVE(bo, bo_synclist); 4093 syncer_worklist_len--; 4094 sync_vnode_count--; 4095 bo->bo_flag &= ~BO_ONWORKLST; 4096 } 4097 mtx_unlock(&sync_mtx); 4098 BO_UNLOCK(bo); 4099 4100 return (0); 4101 } 4102 4103 /* 4104 * Check if vnode represents a disk device 4105 */ 4106 int 4107 vn_isdisk(struct vnode *vp, int *errp) 4108 { 4109 int error; 4110 4111 if (vp->v_type != VCHR) { 4112 error = ENOTBLK; 4113 goto out; 4114 } 4115 error = 0; 4116 dev_lock(); 4117 if (vp->v_rdev == NULL) 4118 error = ENXIO; 4119 else if (vp->v_rdev->si_devsw == NULL) 4120 error = ENXIO; 4121 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 4122 error = ENOTBLK; 4123 dev_unlock(); 4124 out: 4125 if (errp != NULL) 4126 *errp = error; 4127 return (error == 0); 4128 } 4129 4130 /* 4131 * Common filesystem object access control check routine. Accepts a 4132 * vnode's type, "mode", uid and gid, requested access mode, credentials, 4133 * and optional call-by-reference privused argument allowing vaccess() 4134 * to indicate to the caller whether privilege was used to satisfy the 4135 * request (obsoleted). Returns 0 on success, or an errno on failure. 4136 */ 4137 int 4138 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 4139 accmode_t accmode, struct ucred *cred, int *privused) 4140 { 4141 accmode_t dac_granted; 4142 accmode_t priv_granted; 4143 4144 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 4145 ("invalid bit in accmode")); 4146 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 4147 ("VAPPEND without VWRITE")); 4148 4149 /* 4150 * Look for a normal, non-privileged way to access the file/directory 4151 * as requested. If it exists, go with that. 4152 */ 4153 4154 if (privused != NULL) 4155 *privused = 0; 4156 4157 dac_granted = 0; 4158 4159 /* Check the owner. */ 4160 if (cred->cr_uid == file_uid) { 4161 dac_granted |= VADMIN; 4162 if (file_mode & S_IXUSR) 4163 dac_granted |= VEXEC; 4164 if (file_mode & S_IRUSR) 4165 dac_granted |= VREAD; 4166 if (file_mode & S_IWUSR) 4167 dac_granted |= (VWRITE | VAPPEND); 4168 4169 if ((accmode & dac_granted) == accmode) 4170 return (0); 4171 4172 goto privcheck; 4173 } 4174 4175 /* Otherwise, check the groups (first match) */ 4176 if (groupmember(file_gid, cred)) { 4177 if (file_mode & S_IXGRP) 4178 dac_granted |= VEXEC; 4179 if (file_mode & S_IRGRP) 4180 dac_granted |= VREAD; 4181 if (file_mode & S_IWGRP) 4182 dac_granted |= (VWRITE | VAPPEND); 4183 4184 if ((accmode & dac_granted) == accmode) 4185 return (0); 4186 4187 goto privcheck; 4188 } 4189 4190 /* Otherwise, check everyone else. */ 4191 if (file_mode & S_IXOTH) 4192 dac_granted |= VEXEC; 4193 if (file_mode & S_IROTH) 4194 dac_granted |= VREAD; 4195 if (file_mode & S_IWOTH) 4196 dac_granted |= (VWRITE | VAPPEND); 4197 if ((accmode & dac_granted) == accmode) 4198 return (0); 4199 4200 privcheck: 4201 /* 4202 * Build a privilege mask to determine if the set of privileges 4203 * satisfies the requirements when combined with the granted mask 4204 * from above. For each privilege, if the privilege is required, 4205 * bitwise or the request type onto the priv_granted mask. 4206 */ 4207 priv_granted = 0; 4208 4209 if (type == VDIR) { 4210 /* 4211 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 4212 * requests, instead of PRIV_VFS_EXEC. 4213 */ 4214 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4215 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 4216 priv_granted |= VEXEC; 4217 } else { 4218 /* 4219 * Ensure that at least one execute bit is on. Otherwise, 4220 * a privileged user will always succeed, and we don't want 4221 * this to happen unless the file really is executable. 4222 */ 4223 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 4224 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 4225 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 4226 priv_granted |= VEXEC; 4227 } 4228 4229 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 4230 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 4231 priv_granted |= VREAD; 4232 4233 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 4234 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 4235 priv_granted |= (VWRITE | VAPPEND); 4236 4237 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 4238 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 4239 priv_granted |= VADMIN; 4240 4241 if ((accmode & (priv_granted | dac_granted)) == accmode) { 4242 /* XXX audit: privilege used */ 4243 if (privused != NULL) 4244 *privused = 1; 4245 return (0); 4246 } 4247 4248 return ((accmode & VADMIN) ? EPERM : EACCES); 4249 } 4250 4251 /* 4252 * Credential check based on process requesting service, and per-attribute 4253 * permissions. 4254 */ 4255 int 4256 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 4257 struct thread *td, accmode_t accmode) 4258 { 4259 4260 /* 4261 * Kernel-invoked always succeeds. 4262 */ 4263 if (cred == NOCRED) 4264 return (0); 4265 4266 /* 4267 * Do not allow privileged processes in jail to directly manipulate 4268 * system attributes. 4269 */ 4270 switch (attrnamespace) { 4271 case EXTATTR_NAMESPACE_SYSTEM: 4272 /* Potentially should be: return (EPERM); */ 4273 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 4274 case EXTATTR_NAMESPACE_USER: 4275 return (VOP_ACCESS(vp, accmode, cred, td)); 4276 default: 4277 return (EPERM); 4278 } 4279 } 4280 4281 #ifdef DEBUG_VFS_LOCKS 4282 /* 4283 * This only exists to supress warnings from unlocked specfs accesses. It is 4284 * no longer ok to have an unlocked VFS. 4285 */ 4286 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 4287 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 4288 4289 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 4290 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 4291 "Drop into debugger on lock violation"); 4292 4293 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 4294 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 4295 0, "Check for interlock across VOPs"); 4296 4297 int vfs_badlock_print = 1; /* Print lock violations. */ 4298 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 4299 0, "Print lock violations"); 4300 4301 #ifdef KDB 4302 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 4303 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 4304 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 4305 #endif 4306 4307 static void 4308 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 4309 { 4310 4311 #ifdef KDB 4312 if (vfs_badlock_backtrace) 4313 kdb_backtrace(); 4314 #endif 4315 if (vfs_badlock_print) 4316 printf("%s: %p %s\n", str, (void *)vp, msg); 4317 if (vfs_badlock_ddb) 4318 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4319 } 4320 4321 void 4322 assert_vi_locked(struct vnode *vp, const char *str) 4323 { 4324 4325 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 4326 vfs_badlock("interlock is not locked but should be", str, vp); 4327 } 4328 4329 void 4330 assert_vi_unlocked(struct vnode *vp, const char *str) 4331 { 4332 4333 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 4334 vfs_badlock("interlock is locked but should not be", str, vp); 4335 } 4336 4337 void 4338 assert_vop_locked(struct vnode *vp, const char *str) 4339 { 4340 int locked; 4341 4342 if (!IGNORE_LOCK(vp)) { 4343 locked = VOP_ISLOCKED(vp); 4344 if (locked == 0 || locked == LK_EXCLOTHER) 4345 vfs_badlock("is not locked but should be", str, vp); 4346 } 4347 } 4348 4349 void 4350 assert_vop_unlocked(struct vnode *vp, const char *str) 4351 { 4352 4353 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 4354 vfs_badlock("is locked but should not be", str, vp); 4355 } 4356 4357 void 4358 assert_vop_elocked(struct vnode *vp, const char *str) 4359 { 4360 4361 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 4362 vfs_badlock("is not exclusive locked but should be", str, vp); 4363 } 4364 4365 #if 0 4366 void 4367 assert_vop_elocked_other(struct vnode *vp, const char *str) 4368 { 4369 4370 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLOTHER) 4371 vfs_badlock("is not exclusive locked by another thread", 4372 str, vp); 4373 } 4374 4375 void 4376 assert_vop_slocked(struct vnode *vp, const char *str) 4377 { 4378 4379 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_SHARED) 4380 vfs_badlock("is not locked shared but should be", str, vp); 4381 } 4382 #endif /* 0 */ 4383 #endif /* DEBUG_VFS_LOCKS */ 4384 4385 void 4386 vop_rename_fail(struct vop_rename_args *ap) 4387 { 4388 4389 if (ap->a_tvp != NULL) 4390 vput(ap->a_tvp); 4391 if (ap->a_tdvp == ap->a_tvp) 4392 vrele(ap->a_tdvp); 4393 else 4394 vput(ap->a_tdvp); 4395 vrele(ap->a_fdvp); 4396 vrele(ap->a_fvp); 4397 } 4398 4399 void 4400 vop_rename_pre(void *ap) 4401 { 4402 struct vop_rename_args *a = ap; 4403 4404 #ifdef DEBUG_VFS_LOCKS 4405 if (a->a_tvp) 4406 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 4407 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 4408 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 4409 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 4410 4411 /* Check the source (from). */ 4412 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 4413 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 4414 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 4415 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 4416 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 4417 4418 /* Check the target. */ 4419 if (a->a_tvp) 4420 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 4421 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 4422 #endif 4423 if (a->a_tdvp != a->a_fdvp) 4424 vhold(a->a_fdvp); 4425 if (a->a_tvp != a->a_fvp) 4426 vhold(a->a_fvp); 4427 vhold(a->a_tdvp); 4428 if (a->a_tvp) 4429 vhold(a->a_tvp); 4430 } 4431 4432 void 4433 vop_strategy_pre(void *ap) 4434 { 4435 #ifdef DEBUG_VFS_LOCKS 4436 struct vop_strategy_args *a; 4437 struct buf *bp; 4438 4439 a = ap; 4440 bp = a->a_bp; 4441 4442 /* 4443 * Cluster ops lock their component buffers but not the IO container. 4444 */ 4445 if ((bp->b_flags & B_CLUSTER) != 0) 4446 return; 4447 4448 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 4449 if (vfs_badlock_print) 4450 printf( 4451 "VOP_STRATEGY: bp is not locked but should be\n"); 4452 if (vfs_badlock_ddb) 4453 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 4454 } 4455 #endif 4456 } 4457 4458 void 4459 vop_lock_pre(void *ap) 4460 { 4461 #ifdef DEBUG_VFS_LOCKS 4462 struct vop_lock1_args *a = ap; 4463 4464 if ((a->a_flags & LK_INTERLOCK) == 0) 4465 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4466 else 4467 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 4468 #endif 4469 } 4470 4471 void 4472 vop_lock_post(void *ap, int rc) 4473 { 4474 #ifdef DEBUG_VFS_LOCKS 4475 struct vop_lock1_args *a = ap; 4476 4477 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 4478 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) 4479 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 4480 #endif 4481 } 4482 4483 void 4484 vop_unlock_pre(void *ap) 4485 { 4486 #ifdef DEBUG_VFS_LOCKS 4487 struct vop_unlock_args *a = ap; 4488 4489 if (a->a_flags & LK_INTERLOCK) 4490 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4491 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4492 #endif 4493 } 4494 4495 void 4496 vop_unlock_post(void *ap, int rc) 4497 { 4498 #ifdef DEBUG_VFS_LOCKS 4499 struct vop_unlock_args *a = ap; 4500 4501 if (a->a_flags & LK_INTERLOCK) 4502 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4503 #endif 4504 } 4505 4506 void 4507 vop_create_post(void *ap, int rc) 4508 { 4509 struct vop_create_args *a = ap; 4510 4511 if (!rc) 4512 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4513 } 4514 4515 void 4516 vop_deleteextattr_post(void *ap, int rc) 4517 { 4518 struct vop_deleteextattr_args *a = ap; 4519 4520 if (!rc) 4521 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4522 } 4523 4524 void 4525 vop_link_post(void *ap, int rc) 4526 { 4527 struct vop_link_args *a = ap; 4528 4529 if (!rc) { 4530 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4531 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4532 } 4533 } 4534 4535 void 4536 vop_mkdir_post(void *ap, int rc) 4537 { 4538 struct vop_mkdir_args *a = ap; 4539 4540 if (!rc) 4541 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4542 } 4543 4544 void 4545 vop_mknod_post(void *ap, int rc) 4546 { 4547 struct vop_mknod_args *a = ap; 4548 4549 if (!rc) 4550 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4551 } 4552 4553 void 4554 vop_reclaim_post(void *ap, int rc) 4555 { 4556 struct vop_reclaim_args *a = ap; 4557 4558 if (!rc) 4559 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); 4560 } 4561 4562 void 4563 vop_remove_post(void *ap, int rc) 4564 { 4565 struct vop_remove_args *a = ap; 4566 4567 if (!rc) { 4568 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4569 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4570 } 4571 } 4572 4573 void 4574 vop_rename_post(void *ap, int rc) 4575 { 4576 struct vop_rename_args *a = ap; 4577 4578 if (!rc) { 4579 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE); 4580 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE); 4581 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4582 if (a->a_tvp) 4583 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4584 } 4585 if (a->a_tdvp != a->a_fdvp) 4586 vdrop(a->a_fdvp); 4587 if (a->a_tvp != a->a_fvp) 4588 vdrop(a->a_fvp); 4589 vdrop(a->a_tdvp); 4590 if (a->a_tvp) 4591 vdrop(a->a_tvp); 4592 } 4593 4594 void 4595 vop_rmdir_post(void *ap, int rc) 4596 { 4597 struct vop_rmdir_args *a = ap; 4598 4599 if (!rc) { 4600 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4601 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4602 } 4603 } 4604 4605 void 4606 vop_setattr_post(void *ap, int rc) 4607 { 4608 struct vop_setattr_args *a = ap; 4609 4610 if (!rc) 4611 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4612 } 4613 4614 void 4615 vop_setextattr_post(void *ap, int rc) 4616 { 4617 struct vop_setextattr_args *a = ap; 4618 4619 if (!rc) 4620 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4621 } 4622 4623 void 4624 vop_symlink_post(void *ap, int rc) 4625 { 4626 struct vop_symlink_args *a = ap; 4627 4628 if (!rc) 4629 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4630 } 4631 4632 static struct knlist fs_knlist; 4633 4634 static void 4635 vfs_event_init(void *arg) 4636 { 4637 knlist_init_mtx(&fs_knlist, NULL); 4638 } 4639 /* XXX - correct order? */ 4640 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 4641 4642 void 4643 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 4644 { 4645 4646 KNOTE_UNLOCKED(&fs_knlist, event); 4647 } 4648 4649 static int filt_fsattach(struct knote *kn); 4650 static void filt_fsdetach(struct knote *kn); 4651 static int filt_fsevent(struct knote *kn, long hint); 4652 4653 struct filterops fs_filtops = { 4654 .f_isfd = 0, 4655 .f_attach = filt_fsattach, 4656 .f_detach = filt_fsdetach, 4657 .f_event = filt_fsevent 4658 }; 4659 4660 static int 4661 filt_fsattach(struct knote *kn) 4662 { 4663 4664 kn->kn_flags |= EV_CLEAR; 4665 knlist_add(&fs_knlist, kn, 0); 4666 return (0); 4667 } 4668 4669 static void 4670 filt_fsdetach(struct knote *kn) 4671 { 4672 4673 knlist_remove(&fs_knlist, kn, 0); 4674 } 4675 4676 static int 4677 filt_fsevent(struct knote *kn, long hint) 4678 { 4679 4680 kn->kn_fflags |= hint; 4681 return (kn->kn_fflags != 0); 4682 } 4683 4684 static int 4685 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 4686 { 4687 struct vfsidctl vc; 4688 int error; 4689 struct mount *mp; 4690 4691 error = SYSCTL_IN(req, &vc, sizeof(vc)); 4692 if (error) 4693 return (error); 4694 if (vc.vc_vers != VFS_CTL_VERS1) 4695 return (EINVAL); 4696 mp = vfs_getvfs(&vc.vc_fsid); 4697 if (mp == NULL) 4698 return (ENOENT); 4699 /* ensure that a specific sysctl goes to the right filesystem. */ 4700 if (strcmp(vc.vc_fstypename, "*") != 0 && 4701 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 4702 vfs_rel(mp); 4703 return (EINVAL); 4704 } 4705 VCTLTOREQ(&vc, req); 4706 error = VFS_SYSCTL(mp, vc.vc_op, req); 4707 vfs_rel(mp); 4708 return (error); 4709 } 4710 4711 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 4712 NULL, 0, sysctl_vfs_ctl, "", 4713 "Sysctl by fsid"); 4714 4715 /* 4716 * Function to initialize a va_filerev field sensibly. 4717 * XXX: Wouldn't a random number make a lot more sense ?? 4718 */ 4719 u_quad_t 4720 init_va_filerev(void) 4721 { 4722 struct bintime bt; 4723 4724 getbinuptime(&bt); 4725 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 4726 } 4727 4728 static int filt_vfsread(struct knote *kn, long hint); 4729 static int filt_vfswrite(struct knote *kn, long hint); 4730 static int filt_vfsvnode(struct knote *kn, long hint); 4731 static void filt_vfsdetach(struct knote *kn); 4732 static struct filterops vfsread_filtops = { 4733 .f_isfd = 1, 4734 .f_detach = filt_vfsdetach, 4735 .f_event = filt_vfsread 4736 }; 4737 static struct filterops vfswrite_filtops = { 4738 .f_isfd = 1, 4739 .f_detach = filt_vfsdetach, 4740 .f_event = filt_vfswrite 4741 }; 4742 static struct filterops vfsvnode_filtops = { 4743 .f_isfd = 1, 4744 .f_detach = filt_vfsdetach, 4745 .f_event = filt_vfsvnode 4746 }; 4747 4748 static void 4749 vfs_knllock(void *arg) 4750 { 4751 struct vnode *vp = arg; 4752 4753 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4754 } 4755 4756 static void 4757 vfs_knlunlock(void *arg) 4758 { 4759 struct vnode *vp = arg; 4760 4761 VOP_UNLOCK(vp, 0); 4762 } 4763 4764 static void 4765 vfs_knl_assert_locked(void *arg) 4766 { 4767 #ifdef DEBUG_VFS_LOCKS 4768 struct vnode *vp = arg; 4769 4770 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 4771 #endif 4772 } 4773 4774 static void 4775 vfs_knl_assert_unlocked(void *arg) 4776 { 4777 #ifdef DEBUG_VFS_LOCKS 4778 struct vnode *vp = arg; 4779 4780 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 4781 #endif 4782 } 4783 4784 int 4785 vfs_kqfilter(struct vop_kqfilter_args *ap) 4786 { 4787 struct vnode *vp = ap->a_vp; 4788 struct knote *kn = ap->a_kn; 4789 struct knlist *knl; 4790 4791 switch (kn->kn_filter) { 4792 case EVFILT_READ: 4793 kn->kn_fop = &vfsread_filtops; 4794 break; 4795 case EVFILT_WRITE: 4796 kn->kn_fop = &vfswrite_filtops; 4797 break; 4798 case EVFILT_VNODE: 4799 kn->kn_fop = &vfsvnode_filtops; 4800 break; 4801 default: 4802 return (EINVAL); 4803 } 4804 4805 kn->kn_hook = (caddr_t)vp; 4806 4807 v_addpollinfo(vp); 4808 if (vp->v_pollinfo == NULL) 4809 return (ENOMEM); 4810 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 4811 vhold(vp); 4812 knlist_add(knl, kn, 0); 4813 4814 return (0); 4815 } 4816 4817 /* 4818 * Detach knote from vnode 4819 */ 4820 static void 4821 filt_vfsdetach(struct knote *kn) 4822 { 4823 struct vnode *vp = (struct vnode *)kn->kn_hook; 4824 4825 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 4826 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 4827 vdrop(vp); 4828 } 4829 4830 /*ARGSUSED*/ 4831 static int 4832 filt_vfsread(struct knote *kn, long hint) 4833 { 4834 struct vnode *vp = (struct vnode *)kn->kn_hook; 4835 struct vattr va; 4836 int res; 4837 4838 /* 4839 * filesystem is gone, so set the EOF flag and schedule 4840 * the knote for deletion. 4841 */ 4842 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 4843 VI_LOCK(vp); 4844 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 4845 VI_UNLOCK(vp); 4846 return (1); 4847 } 4848 4849 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 4850 return (0); 4851 4852 VI_LOCK(vp); 4853 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 4854 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; 4855 VI_UNLOCK(vp); 4856 return (res); 4857 } 4858 4859 /*ARGSUSED*/ 4860 static int 4861 filt_vfswrite(struct knote *kn, long hint) 4862 { 4863 struct vnode *vp = (struct vnode *)kn->kn_hook; 4864 4865 VI_LOCK(vp); 4866 4867 /* 4868 * filesystem is gone, so set the EOF flag and schedule 4869 * the knote for deletion. 4870 */ 4871 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) 4872 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 4873 4874 kn->kn_data = 0; 4875 VI_UNLOCK(vp); 4876 return (1); 4877 } 4878 4879 static int 4880 filt_vfsvnode(struct knote *kn, long hint) 4881 { 4882 struct vnode *vp = (struct vnode *)kn->kn_hook; 4883 int res; 4884 4885 VI_LOCK(vp); 4886 if (kn->kn_sfflags & hint) 4887 kn->kn_fflags |= hint; 4888 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { 4889 kn->kn_flags |= EV_EOF; 4890 VI_UNLOCK(vp); 4891 return (1); 4892 } 4893 res = (kn->kn_fflags != 0); 4894 VI_UNLOCK(vp); 4895 return (res); 4896 } 4897 4898 int 4899 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 4900 { 4901 int error; 4902 4903 if (dp->d_reclen > ap->a_uio->uio_resid) 4904 return (ENAMETOOLONG); 4905 error = uiomove(dp, dp->d_reclen, ap->a_uio); 4906 if (error) { 4907 if (ap->a_ncookies != NULL) { 4908 if (ap->a_cookies != NULL) 4909 free(ap->a_cookies, M_TEMP); 4910 ap->a_cookies = NULL; 4911 *ap->a_ncookies = 0; 4912 } 4913 return (error); 4914 } 4915 if (ap->a_ncookies == NULL) 4916 return (0); 4917 4918 KASSERT(ap->a_cookies, 4919 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 4920 4921 *ap->a_cookies = realloc(*ap->a_cookies, 4922 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 4923 (*ap->a_cookies)[*ap->a_ncookies] = off; 4924 return (0); 4925 } 4926 4927 /* 4928 * Mark for update the access time of the file if the filesystem 4929 * supports VOP_MARKATIME. This functionality is used by execve and 4930 * mmap, so we want to avoid the I/O implied by directly setting 4931 * va_atime for the sake of efficiency. 4932 */ 4933 void 4934 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 4935 { 4936 struct mount *mp; 4937 4938 mp = vp->v_mount; 4939 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 4940 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 4941 (void)VOP_MARKATIME(vp); 4942 } 4943 4944 /* 4945 * The purpose of this routine is to remove granularity from accmode_t, 4946 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 4947 * VADMIN and VAPPEND. 4948 * 4949 * If it returns 0, the caller is supposed to continue with the usual 4950 * access checks using 'accmode' as modified by this routine. If it 4951 * returns nonzero value, the caller is supposed to return that value 4952 * as errno. 4953 * 4954 * Note that after this routine runs, accmode may be zero. 4955 */ 4956 int 4957 vfs_unixify_accmode(accmode_t *accmode) 4958 { 4959 /* 4960 * There is no way to specify explicit "deny" rule using 4961 * file mode or POSIX.1e ACLs. 4962 */ 4963 if (*accmode & VEXPLICIT_DENY) { 4964 *accmode = 0; 4965 return (0); 4966 } 4967 4968 /* 4969 * None of these can be translated into usual access bits. 4970 * Also, the common case for NFSv4 ACLs is to not contain 4971 * either of these bits. Caller should check for VWRITE 4972 * on the containing directory instead. 4973 */ 4974 if (*accmode & (VDELETE_CHILD | VDELETE)) 4975 return (EPERM); 4976 4977 if (*accmode & VADMIN_PERMS) { 4978 *accmode &= ~VADMIN_PERMS; 4979 *accmode |= VADMIN; 4980 } 4981 4982 /* 4983 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 4984 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 4985 */ 4986 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 4987 4988 return (0); 4989 } 4990 4991 /* 4992 * These are helper functions for filesystems to traverse all 4993 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. 4994 * 4995 * This interface replaces MNT_VNODE_FOREACH. 4996 */ 4997 4998 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 4999 5000 struct vnode * 5001 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) 5002 { 5003 struct vnode *vp; 5004 5005 if (should_yield()) 5006 kern_yield(PRI_USER); 5007 MNT_ILOCK(mp); 5008 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5009 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 5010 while (vp != NULL && (vp->v_type == VMARKER || 5011 (vp->v_iflag & VI_DOOMED) != 0)) 5012 vp = TAILQ_NEXT(vp, v_nmntvnodes); 5013 5014 /* Check if we are done */ 5015 if (vp == NULL) { 5016 __mnt_vnode_markerfree_all(mvp, mp); 5017 /* MNT_IUNLOCK(mp); -- done in above function */ 5018 mtx_assert(MNT_MTX(mp), MA_NOTOWNED); 5019 return (NULL); 5020 } 5021 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5022 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5023 VI_LOCK(vp); 5024 MNT_IUNLOCK(mp); 5025 return (vp); 5026 } 5027 5028 struct vnode * 5029 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) 5030 { 5031 struct vnode *vp; 5032 5033 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5034 MNT_ILOCK(mp); 5035 MNT_REF(mp); 5036 (*mvp)->v_type = VMARKER; 5037 5038 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 5039 while (vp != NULL && (vp->v_type == VMARKER || 5040 (vp->v_iflag & VI_DOOMED) != 0)) 5041 vp = TAILQ_NEXT(vp, v_nmntvnodes); 5042 5043 /* Check if we are done */ 5044 if (vp == NULL) { 5045 MNT_REL(mp); 5046 MNT_IUNLOCK(mp); 5047 free(*mvp, M_VNODE_MARKER); 5048 *mvp = NULL; 5049 return (NULL); 5050 } 5051 (*mvp)->v_mount = mp; 5052 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 5053 VI_LOCK(vp); 5054 MNT_IUNLOCK(mp); 5055 return (vp); 5056 } 5057 5058 5059 void 5060 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) 5061 { 5062 5063 if (*mvp == NULL) { 5064 MNT_IUNLOCK(mp); 5065 return; 5066 } 5067 5068 mtx_assert(MNT_MTX(mp), MA_OWNED); 5069 5070 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5071 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 5072 MNT_REL(mp); 5073 MNT_IUNLOCK(mp); 5074 free(*mvp, M_VNODE_MARKER); 5075 *mvp = NULL; 5076 } 5077 5078 /* 5079 * These are helper functions for filesystems to traverse their 5080 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h 5081 */ 5082 static void 5083 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5084 { 5085 5086 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5087 5088 MNT_ILOCK(mp); 5089 MNT_REL(mp); 5090 MNT_IUNLOCK(mp); 5091 free(*mvp, M_VNODE_MARKER); 5092 *mvp = NULL; 5093 } 5094 5095 static struct vnode * 5096 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5097 { 5098 struct vnode *vp, *nvp; 5099 5100 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 5101 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 5102 restart: 5103 vp = TAILQ_NEXT(*mvp, v_actfreelist); 5104 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5105 while (vp != NULL) { 5106 if (vp->v_type == VMARKER) { 5107 vp = TAILQ_NEXT(vp, v_actfreelist); 5108 continue; 5109 } 5110 if (!VI_TRYLOCK(vp)) { 5111 if (mp_ncpus == 1 || should_yield()) { 5112 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5113 mtx_unlock(&vnode_free_list_mtx); 5114 pause("vnacti", 1); 5115 mtx_lock(&vnode_free_list_mtx); 5116 goto restart; 5117 } 5118 continue; 5119 } 5120 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); 5121 KASSERT(vp->v_mount == mp || vp->v_mount == NULL, 5122 ("alien vnode on the active list %p %p", vp, mp)); 5123 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) 5124 break; 5125 nvp = TAILQ_NEXT(vp, v_actfreelist); 5126 VI_UNLOCK(vp); 5127 vp = nvp; 5128 } 5129 5130 /* Check if we are done */ 5131 if (vp == NULL) { 5132 mtx_unlock(&vnode_free_list_mtx); 5133 mnt_vnode_markerfree_active(mvp, mp); 5134 return (NULL); 5135 } 5136 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); 5137 mtx_unlock(&vnode_free_list_mtx); 5138 ASSERT_VI_LOCKED(vp, "active iter"); 5139 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); 5140 return (vp); 5141 } 5142 5143 struct vnode * 5144 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) 5145 { 5146 5147 if (should_yield()) 5148 kern_yield(PRI_USER); 5149 mtx_lock(&vnode_free_list_mtx); 5150 return (mnt_vnode_next_active(mvp, mp)); 5151 } 5152 5153 struct vnode * 5154 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) 5155 { 5156 struct vnode *vp; 5157 5158 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); 5159 MNT_ILOCK(mp); 5160 MNT_REF(mp); 5161 MNT_IUNLOCK(mp); 5162 (*mvp)->v_type = VMARKER; 5163 (*mvp)->v_mount = mp; 5164 5165 mtx_lock(&vnode_free_list_mtx); 5166 vp = TAILQ_FIRST(&mp->mnt_activevnodelist); 5167 if (vp == NULL) { 5168 mtx_unlock(&vnode_free_list_mtx); 5169 mnt_vnode_markerfree_active(mvp, mp); 5170 return (NULL); 5171 } 5172 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); 5173 return (mnt_vnode_next_active(mvp, mp)); 5174 } 5175 5176 void 5177 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) 5178 { 5179 5180 if (*mvp == NULL) 5181 return; 5182 5183 mtx_lock(&vnode_free_list_mtx); 5184 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); 5185 mtx_unlock(&vnode_free_list_mtx); 5186 mnt_vnode_markerfree_active(mvp, mp); 5187 } 5188