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