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_ddb.h" 45 #include "opt_mac.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/conf.h> 52 #include <sys/dirent.h> 53 #include <sys/event.h> 54 #include <sys/eventhandler.h> 55 #include <sys/extattr.h> 56 #include <sys/file.h> 57 #include <sys/fcntl.h> 58 #include <sys/jail.h> 59 #include <sys/kdb.h> 60 #include <sys/kernel.h> 61 #include <sys/kthread.h> 62 #include <sys/malloc.h> 63 #include <sys/mount.h> 64 #include <sys/namei.h> 65 #include <sys/priv.h> 66 #include <sys/reboot.h> 67 #include <sys/sleepqueue.h> 68 #include <sys/stat.h> 69 #include <sys/sysctl.h> 70 #include <sys/syslog.h> 71 #include <sys/vmmeter.h> 72 #include <sys/vnode.h> 73 74 #include <machine/stdarg.h> 75 76 #include <security/mac/mac_framework.h> 77 78 #include <vm/vm.h> 79 #include <vm/vm_object.h> 80 #include <vm/vm_extern.h> 81 #include <vm/pmap.h> 82 #include <vm/vm_map.h> 83 #include <vm/vm_page.h> 84 #include <vm/vm_kern.h> 85 #include <vm/uma.h> 86 87 #ifdef DDB 88 #include <ddb/ddb.h> 89 #endif 90 91 static MALLOC_DEFINE(M_NETADDR, "subr_export_host", "Export host address structure"); 92 93 static void delmntque(struct vnode *vp); 94 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 95 int slpflag, int slptimeo); 96 static void syncer_shutdown(void *arg, int howto); 97 static int vtryrecycle(struct vnode *vp); 98 static void vbusy(struct vnode *vp); 99 static void vinactive(struct vnode *, struct thread *); 100 static void v_incr_usecount(struct vnode *); 101 static void v_decr_usecount(struct vnode *); 102 static void v_decr_useonly(struct vnode *); 103 static void v_upgrade_usecount(struct vnode *); 104 static void vfree(struct vnode *); 105 static void vnlru_free(int); 106 static void vdestroy(struct vnode *); 107 static void vgonel(struct vnode *); 108 static void vfs_knllock(void *arg); 109 static void vfs_knlunlock(void *arg); 110 static int vfs_knllocked(void *arg); 111 112 113 /* 114 * Enable Giant pushdown based on whether or not the vm is mpsafe in this 115 * build. Without mpsafevm the buffer cache can not run Giant free. 116 */ 117 int mpsafe_vfs = 1; 118 TUNABLE_INT("debug.mpsafevfs", &mpsafe_vfs); 119 SYSCTL_INT(_debug, OID_AUTO, mpsafevfs, CTLFLAG_RD, &mpsafe_vfs, 0, 120 "MPSAFE VFS"); 121 122 /* 123 * Number of vnodes in existence. Increased whenever getnewvnode() 124 * allocates a new vnode, decreased on vdestroy() called on VI_DOOMed 125 * vnode. 126 */ 127 static unsigned long numvnodes; 128 129 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 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 may simply be files which have been stat'd 151 * but not read. This is somewhat common, and a small cache of such files 152 * should be kept to avoid recreation costs. 153 */ 154 static u_long wantfreevnodes; 155 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 156 /* Number of vnodes in the free list. */ 157 static u_long freevnodes; 158 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 159 160 /* 161 * Various variables used for debugging the new implementation of 162 * reassignbuf(). 163 * XXX these are probably of (very) limited utility now. 164 */ 165 static int reassignbufcalls; 166 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 167 168 /* 169 * Cache for the mount type id assigned to NFS. This is used for 170 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 171 */ 172 int nfs_mount_type = -1; 173 174 /* To keep more than one thread at a time from running vfs_getnewfsid */ 175 static struct mtx mntid_mtx; 176 177 /* 178 * Lock for any access to the following: 179 * vnode_free_list 180 * numvnodes 181 * freevnodes 182 */ 183 static struct mtx vnode_free_list_mtx; 184 185 /* Publicly exported FS */ 186 struct nfs_public nfs_pub; 187 188 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 189 static uma_zone_t vnode_zone; 190 static uma_zone_t vnodepoll_zone; 191 192 /* Set to 1 to print out reclaim of active vnodes */ 193 int prtactive; 194 195 /* 196 * The workitem queue. 197 * 198 * It is useful to delay writes of file data and filesystem metadata 199 * for tens of seconds so that quickly created and deleted files need 200 * not waste disk bandwidth being created and removed. To realize this, 201 * we append vnodes to a "workitem" queue. When running with a soft 202 * updates implementation, most pending metadata dependencies should 203 * not wait for more than a few seconds. Thus, mounted on block devices 204 * are delayed only about a half the time that file data is delayed. 205 * Similarly, directory updates are more critical, so are only delayed 206 * about a third the time that file data is delayed. Thus, there are 207 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 208 * one each second (driven off the filesystem syncer process). The 209 * syncer_delayno variable indicates the next queue that is to be processed. 210 * Items that need to be processed soon are placed in this queue: 211 * 212 * syncer_workitem_pending[syncer_delayno] 213 * 214 * A delay of fifteen seconds is done by placing the request fifteen 215 * entries later in the queue: 216 * 217 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 218 * 219 */ 220 static int syncer_delayno; 221 static long syncer_mask; 222 LIST_HEAD(synclist, bufobj); 223 static struct synclist *syncer_workitem_pending; 224 /* 225 * The sync_mtx protects: 226 * bo->bo_synclist 227 * sync_vnode_count 228 * syncer_delayno 229 * syncer_state 230 * syncer_workitem_pending 231 * syncer_worklist_len 232 * rushjob 233 */ 234 static struct mtx sync_mtx; 235 236 #define SYNCER_MAXDELAY 32 237 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 238 static int syncdelay = 30; /* max time to delay syncing data */ 239 static int filedelay = 30; /* time to delay syncing files */ 240 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 241 static int dirdelay = 29; /* time to delay syncing directories */ 242 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 243 static int metadelay = 28; /* time to delay syncing metadata */ 244 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 245 static int rushjob; /* number of slots to run ASAP */ 246 static int stat_rush_requests; /* number of times I/O speeded up */ 247 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 248 249 /* 250 * When shutting down the syncer, run it at four times normal speed. 251 */ 252 #define SYNCER_SHUTDOWN_SPEEDUP 4 253 static int sync_vnode_count; 254 static int syncer_worklist_len; 255 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 256 syncer_state; 257 258 /* 259 * Number of vnodes we want to exist at any one time. This is mostly used 260 * to size hash tables in vnode-related code. It is normally not used in 261 * getnewvnode(), as wantfreevnodes is normally nonzero.) 262 * 263 * XXX desiredvnodes is historical cruft and should not exist. 264 */ 265 int desiredvnodes; 266 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 267 &desiredvnodes, 0, "Maximum number of vnodes"); 268 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 269 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)"); 270 static int vnlru_nowhere; 271 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 272 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 273 274 /* 275 * Macros to control when a vnode is freed and recycled. All require 276 * the vnode interlock. 277 */ 278 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) 279 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) 280 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt) 281 282 283 /* 284 * Initialize the vnode management data structures. 285 */ 286 #ifndef MAXVNODES_MAX 287 #define MAXVNODES_MAX 100000 288 #endif 289 static void 290 vntblinit(void *dummy __unused) 291 { 292 293 /* 294 * Desiredvnodes is a function of the physical memory size and 295 * the kernel's heap size. Specifically, desiredvnodes scales 296 * in proportion to the physical memory size until two fifths 297 * of the kernel's heap size is consumed by vnodes and vm 298 * objects. 299 */ 300 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / 301 (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); 302 if (desiredvnodes > MAXVNODES_MAX) { 303 if (bootverbose) 304 printf("Reducing kern.maxvnodes %d -> %d\n", 305 desiredvnodes, MAXVNODES_MAX); 306 desiredvnodes = MAXVNODES_MAX; 307 } 308 wantfreevnodes = desiredvnodes / 4; 309 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 310 TAILQ_INIT(&vnode_free_list); 311 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 312 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 313 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 314 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 315 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 316 /* 317 * Initialize the filesystem syncer. 318 */ 319 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 320 &syncer_mask); 321 syncer_maxdelay = syncer_mask + 1; 322 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 323 } 324 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 325 326 327 /* 328 * Mark a mount point as busy. Used to synchronize access and to delay 329 * unmounting. Interlock is not released on failure. 330 */ 331 int 332 vfs_busy(struct mount *mp, int flags, struct mtx *interlkp, 333 struct thread *td) 334 { 335 int lkflags; 336 337 MNT_ILOCK(mp); 338 MNT_REF(mp); 339 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 340 if (flags & LK_NOWAIT) { 341 MNT_REL(mp); 342 MNT_IUNLOCK(mp); 343 return (ENOENT); 344 } 345 if (interlkp) 346 mtx_unlock(interlkp); 347 mp->mnt_kern_flag |= MNTK_MWAIT; 348 /* 349 * Since all busy locks are shared except the exclusive 350 * lock granted when unmounting, the only place that a 351 * wakeup needs to be done is at the release of the 352 * exclusive lock at the end of dounmount. 353 */ 354 msleep(mp, MNT_MTX(mp), PVFS, "vfs_busy", 0); 355 MNT_REL(mp); 356 MNT_IUNLOCK(mp); 357 if (interlkp) 358 mtx_lock(interlkp); 359 return (ENOENT); 360 } 361 if (interlkp) 362 mtx_unlock(interlkp); 363 lkflags = LK_SHARED | LK_INTERLOCK; 364 if (lockmgr(&mp->mnt_lock, lkflags, MNT_MTX(mp), td)) 365 panic("vfs_busy: unexpected lock failure"); 366 return (0); 367 } 368 369 /* 370 * Free a busy filesystem. 371 */ 372 void 373 vfs_unbusy(struct mount *mp, struct thread *td) 374 { 375 376 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 377 vfs_rel(mp); 378 } 379 380 /* 381 * Lookup a mount point by filesystem identifier. 382 */ 383 struct mount * 384 vfs_getvfs(fsid_t *fsid) 385 { 386 struct mount *mp; 387 388 mtx_lock(&mountlist_mtx); 389 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 390 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 391 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 392 vfs_ref(mp); 393 mtx_unlock(&mountlist_mtx); 394 return (mp); 395 } 396 } 397 mtx_unlock(&mountlist_mtx); 398 return ((struct mount *) 0); 399 } 400 401 /* 402 * Check if a user can access privileged mount options. 403 */ 404 int 405 vfs_suser(struct mount *mp, struct thread *td) 406 { 407 int error; 408 409 /* 410 * If the thread is jailed, but this is not a jail-friendly file 411 * system, deny immediately. 412 */ 413 if (jailed(td->td_ucred) && !(mp->mnt_vfc->vfc_flags & VFCF_JAIL)) 414 return (EPERM); 415 416 /* 417 * If the file system was mounted outside a jail and a jailed thread 418 * tries to access it, deny immediately. 419 */ 420 if (!jailed(mp->mnt_cred) && jailed(td->td_ucred)) 421 return (EPERM); 422 423 /* 424 * If the file system was mounted inside different jail that the jail of 425 * the calling thread, deny immediately. 426 */ 427 if (jailed(mp->mnt_cred) && jailed(td->td_ucred) && 428 mp->mnt_cred->cr_prison != td->td_ucred->cr_prison) { 429 return (EPERM); 430 } 431 432 if ((mp->mnt_flag & MNT_USER) == 0 || 433 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 434 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 435 return (error); 436 } 437 return (0); 438 } 439 440 /* 441 * Get a new unique fsid. Try to make its val[0] unique, since this value 442 * will be used to create fake device numbers for stat(). Also try (but 443 * not so hard) make its val[0] unique mod 2^16, since some emulators only 444 * support 16-bit device numbers. We end up with unique val[0]'s for the 445 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 446 * 447 * Keep in mind that several mounts may be running in parallel. Starting 448 * the search one past where the previous search terminated is both a 449 * micro-optimization and a defense against returning the same fsid to 450 * different mounts. 451 */ 452 void 453 vfs_getnewfsid(struct mount *mp) 454 { 455 static u_int16_t mntid_base; 456 struct mount *nmp; 457 fsid_t tfsid; 458 int mtype; 459 460 mtx_lock(&mntid_mtx); 461 mtype = mp->mnt_vfc->vfc_typenum; 462 tfsid.val[1] = mtype; 463 mtype = (mtype & 0xFF) << 24; 464 for (;;) { 465 tfsid.val[0] = makedev(255, 466 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 467 mntid_base++; 468 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 469 break; 470 vfs_rel(nmp); 471 } 472 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 473 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 474 mtx_unlock(&mntid_mtx); 475 } 476 477 /* 478 * Knob to control the precision of file timestamps: 479 * 480 * 0 = seconds only; nanoseconds zeroed. 481 * 1 = seconds and nanoseconds, accurate within 1/HZ. 482 * 2 = seconds and nanoseconds, truncated to microseconds. 483 * >=3 = seconds and nanoseconds, maximum precision. 484 */ 485 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 486 487 static int timestamp_precision = TSP_SEC; 488 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 489 ×tamp_precision, 0, ""); 490 491 /* 492 * Get a current timestamp. 493 */ 494 void 495 vfs_timestamp(struct timespec *tsp) 496 { 497 struct timeval tv; 498 499 switch (timestamp_precision) { 500 case TSP_SEC: 501 tsp->tv_sec = time_second; 502 tsp->tv_nsec = 0; 503 break; 504 case TSP_HZ: 505 getnanotime(tsp); 506 break; 507 case TSP_USEC: 508 microtime(&tv); 509 TIMEVAL_TO_TIMESPEC(&tv, tsp); 510 break; 511 case TSP_NSEC: 512 default: 513 nanotime(tsp); 514 break; 515 } 516 } 517 518 /* 519 * Set vnode attributes to VNOVAL 520 */ 521 void 522 vattr_null(struct vattr *vap) 523 { 524 525 vap->va_type = VNON; 526 vap->va_size = VNOVAL; 527 vap->va_bytes = VNOVAL; 528 vap->va_mode = VNOVAL; 529 vap->va_nlink = VNOVAL; 530 vap->va_uid = VNOVAL; 531 vap->va_gid = VNOVAL; 532 vap->va_fsid = VNOVAL; 533 vap->va_fileid = VNOVAL; 534 vap->va_blocksize = VNOVAL; 535 vap->va_rdev = VNOVAL; 536 vap->va_atime.tv_sec = VNOVAL; 537 vap->va_atime.tv_nsec = VNOVAL; 538 vap->va_mtime.tv_sec = VNOVAL; 539 vap->va_mtime.tv_nsec = VNOVAL; 540 vap->va_ctime.tv_sec = VNOVAL; 541 vap->va_ctime.tv_nsec = VNOVAL; 542 vap->va_birthtime.tv_sec = VNOVAL; 543 vap->va_birthtime.tv_nsec = VNOVAL; 544 vap->va_flags = VNOVAL; 545 vap->va_gen = VNOVAL; 546 vap->va_vaflags = 0; 547 } 548 549 /* 550 * This routine is called when we have too many vnodes. It attempts 551 * to free <count> vnodes and will potentially free vnodes that still 552 * have VM backing store (VM backing store is typically the cause 553 * of a vnode blowout so we want to do this). Therefore, this operation 554 * is not considered cheap. 555 * 556 * A number of conditions may prevent a vnode from being reclaimed. 557 * the buffer cache may have references on the vnode, a directory 558 * vnode may still have references due to the namei cache representing 559 * underlying files, or the vnode may be in active use. It is not 560 * desireable to reuse such vnodes. These conditions may cause the 561 * number of vnodes to reach some minimum value regardless of what 562 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 563 */ 564 static int 565 vlrureclaim(struct mount *mp) 566 { 567 struct thread *td; 568 struct vnode *vp; 569 int done; 570 int trigger; 571 int usevnodes; 572 int count; 573 574 /* 575 * Calculate the trigger point, don't allow user 576 * screwups to blow us up. This prevents us from 577 * recycling vnodes with lots of resident pages. We 578 * aren't trying to free memory, we are trying to 579 * free vnodes. 580 */ 581 usevnodes = desiredvnodes; 582 if (usevnodes <= 0) 583 usevnodes = 1; 584 trigger = cnt.v_page_count * 2 / usevnodes; 585 done = 0; 586 td = curthread; 587 vn_start_write(NULL, &mp, V_WAIT); 588 MNT_ILOCK(mp); 589 count = mp->mnt_nvnodelistsize / 10 + 1; 590 while (count != 0) { 591 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 592 while (vp != NULL && vp->v_type == VMARKER) 593 vp = TAILQ_NEXT(vp, v_nmntvnodes); 594 if (vp == NULL) 595 break; 596 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 597 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 598 --count; 599 if (!VI_TRYLOCK(vp)) 600 goto next_iter; 601 /* 602 * If it's been deconstructed already, it's still 603 * referenced, or it exceeds the trigger, skip it. 604 */ 605 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) || 606 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 607 vp->v_object->resident_page_count > trigger)) { 608 VI_UNLOCK(vp); 609 goto next_iter; 610 } 611 MNT_IUNLOCK(mp); 612 vholdl(vp); 613 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 614 vdrop(vp); 615 goto next_iter_mntunlocked; 616 } 617 VI_LOCK(vp); 618 /* 619 * v_usecount may have been bumped after VOP_LOCK() dropped 620 * the vnode interlock and before it was locked again. 621 * 622 * It is not necessary to recheck VI_DOOMED because it can 623 * only be set by another thread that holds both the vnode 624 * lock and vnode interlock. If another thread has the 625 * vnode lock before we get to VOP_LOCK() and obtains the 626 * vnode interlock after VOP_LOCK() drops the vnode 627 * interlock, the other thread will be unable to drop the 628 * vnode lock before our VOP_LOCK() call fails. 629 */ 630 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) || 631 (vp->v_object != NULL && 632 vp->v_object->resident_page_count > trigger)) { 633 VOP_UNLOCK(vp, LK_INTERLOCK); 634 goto next_iter_mntunlocked; 635 } 636 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 637 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 638 vgonel(vp); 639 VOP_UNLOCK(vp, 0); 640 vdropl(vp); 641 done++; 642 next_iter_mntunlocked: 643 if ((count % 256) != 0) 644 goto relock_mnt; 645 goto yield; 646 next_iter: 647 if ((count % 256) != 0) 648 continue; 649 MNT_IUNLOCK(mp); 650 yield: 651 uio_yield(); 652 relock_mnt: 653 MNT_ILOCK(mp); 654 } 655 MNT_IUNLOCK(mp); 656 vn_finished_write(mp); 657 return done; 658 } 659 660 /* 661 * Attempt to keep the free list at wantfreevnodes length. 662 */ 663 static void 664 vnlru_free(int count) 665 { 666 struct vnode *vp; 667 int vfslocked; 668 669 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 670 for (; count > 0; count--) { 671 vp = TAILQ_FIRST(&vnode_free_list); 672 /* 673 * The list can be modified while the free_list_mtx 674 * has been dropped and vp could be NULL here. 675 */ 676 if (!vp) 677 break; 678 VNASSERT(vp->v_op != NULL, vp, 679 ("vnlru_free: vnode already reclaimed.")); 680 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 681 /* 682 * Don't recycle if we can't get the interlock. 683 */ 684 if (!VI_TRYLOCK(vp)) { 685 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 686 continue; 687 } 688 VNASSERT(VCANRECYCLE(vp), vp, 689 ("vp inconsistent on freelist")); 690 freevnodes--; 691 vp->v_iflag &= ~VI_FREE; 692 vholdl(vp); 693 mtx_unlock(&vnode_free_list_mtx); 694 VI_UNLOCK(vp); 695 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 696 vtryrecycle(vp); 697 VFS_UNLOCK_GIANT(vfslocked); 698 /* 699 * If the recycled succeeded this vdrop will actually free 700 * the vnode. If not it will simply place it back on 701 * the free list. 702 */ 703 vdrop(vp); 704 mtx_lock(&vnode_free_list_mtx); 705 } 706 } 707 /* 708 * Attempt to recycle vnodes in a context that is always safe to block. 709 * Calling vlrurecycle() from the bowels of filesystem code has some 710 * interesting deadlock problems. 711 */ 712 static struct proc *vnlruproc; 713 static int vnlruproc_sig; 714 715 static void 716 vnlru_proc(void) 717 { 718 struct mount *mp, *nmp; 719 int done; 720 struct proc *p = vnlruproc; 721 struct thread *td = curthread; 722 723 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 724 SHUTDOWN_PRI_FIRST); 725 726 mtx_lock(&Giant); 727 728 for (;;) { 729 kproc_suspend_check(p); 730 mtx_lock(&vnode_free_list_mtx); 731 if (freevnodes > wantfreevnodes) 732 vnlru_free(freevnodes - wantfreevnodes); 733 if (numvnodes <= desiredvnodes * 9 / 10) { 734 vnlruproc_sig = 0; 735 wakeup(&vnlruproc_sig); 736 msleep(vnlruproc, &vnode_free_list_mtx, 737 PVFS|PDROP, "vlruwt", hz); 738 continue; 739 } 740 mtx_unlock(&vnode_free_list_mtx); 741 done = 0; 742 mtx_lock(&mountlist_mtx); 743 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 744 int vfsunlocked; 745 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 746 nmp = TAILQ_NEXT(mp, mnt_list); 747 continue; 748 } 749 if (!VFS_NEEDSGIANT(mp)) { 750 mtx_unlock(&Giant); 751 vfsunlocked = 1; 752 } else 753 vfsunlocked = 0; 754 done += vlrureclaim(mp); 755 if (vfsunlocked) 756 mtx_lock(&Giant); 757 mtx_lock(&mountlist_mtx); 758 nmp = TAILQ_NEXT(mp, mnt_list); 759 vfs_unbusy(mp, td); 760 } 761 mtx_unlock(&mountlist_mtx); 762 if (done == 0) { 763 EVENTHANDLER_INVOKE(vfs_lowvnodes, desiredvnodes / 10); 764 #if 0 765 /* These messages are temporary debugging aids */ 766 if (vnlru_nowhere < 5) 767 printf("vnlru process getting nowhere..\n"); 768 else if (vnlru_nowhere == 5) 769 printf("vnlru process messages stopped.\n"); 770 #endif 771 vnlru_nowhere++; 772 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 773 } else 774 uio_yield(); 775 } 776 } 777 778 static struct kproc_desc vnlru_kp = { 779 "vnlru", 780 vnlru_proc, 781 &vnlruproc 782 }; 783 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 784 785 /* 786 * Routines having to do with the management of the vnode table. 787 */ 788 789 static void 790 vdestroy(struct vnode *vp) 791 { 792 struct bufobj *bo; 793 794 CTR1(KTR_VFS, "vdestroy vp %p", vp); 795 mtx_lock(&vnode_free_list_mtx); 796 numvnodes--; 797 mtx_unlock(&vnode_free_list_mtx); 798 bo = &vp->v_bufobj; 799 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 800 ("cleaned vnode still on the free list.")); 801 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 802 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 803 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 804 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 805 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 806 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 807 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL")); 808 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 809 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL")); 810 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 811 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 812 VI_UNLOCK(vp); 813 #ifdef MAC 814 mac_vnode_destroy(vp); 815 #endif 816 if (vp->v_pollinfo != NULL) { 817 knlist_destroy(&vp->v_pollinfo->vpi_selinfo.si_note); 818 mtx_destroy(&vp->v_pollinfo->vpi_lock); 819 uma_zfree(vnodepoll_zone, vp->v_pollinfo); 820 } 821 #ifdef INVARIANTS 822 /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */ 823 vp->v_op = NULL; 824 #endif 825 lockdestroy(vp->v_vnlock); 826 mtx_destroy(&vp->v_interlock); 827 uma_zfree(vnode_zone, vp); 828 } 829 830 /* 831 * Try to recycle a freed vnode. We abort if anyone picks up a reference 832 * before we actually vgone(). This function must be called with the vnode 833 * held to prevent the vnode from being returned to the free list midway 834 * through vgone(). 835 */ 836 static int 837 vtryrecycle(struct vnode *vp) 838 { 839 struct mount *vnmp; 840 841 CTR1(KTR_VFS, "vtryrecycle: trying vp %p", vp); 842 VNASSERT(vp->v_holdcnt, vp, 843 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 844 /* 845 * This vnode may found and locked via some other list, if so we 846 * can't recycle it yet. 847 */ 848 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) 849 return (EWOULDBLOCK); 850 /* 851 * Don't recycle if its filesystem is being suspended. 852 */ 853 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 854 VOP_UNLOCK(vp, 0); 855 return (EBUSY); 856 } 857 /* 858 * If we got this far, we need to acquire the interlock and see if 859 * anyone picked up this vnode from another list. If not, we will 860 * mark it with DOOMED via vgonel() so that anyone who does find it 861 * will skip over it. 862 */ 863 VI_LOCK(vp); 864 if (vp->v_usecount) { 865 VOP_UNLOCK(vp, LK_INTERLOCK); 866 vn_finished_write(vnmp); 867 return (EBUSY); 868 } 869 if ((vp->v_iflag & VI_DOOMED) == 0) 870 vgonel(vp); 871 VOP_UNLOCK(vp, LK_INTERLOCK); 872 vn_finished_write(vnmp); 873 CTR1(KTR_VFS, "vtryrecycle: recycled vp %p", vp); 874 return (0); 875 } 876 877 /* 878 * Return the next vnode from the free list. 879 */ 880 int 881 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 882 struct vnode **vpp) 883 { 884 struct vnode *vp = NULL; 885 struct bufobj *bo; 886 887 mtx_lock(&vnode_free_list_mtx); 888 /* 889 * Lend our context to reclaim vnodes if they've exceeded the max. 890 */ 891 if (freevnodes > wantfreevnodes) 892 vnlru_free(1); 893 /* 894 * Wait for available vnodes. 895 */ 896 if (numvnodes > desiredvnodes) { 897 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) { 898 /* 899 * File system is beeing suspended, we cannot risk a 900 * deadlock here, so allocate new vnode anyway. 901 */ 902 if (freevnodes > wantfreevnodes) 903 vnlru_free(freevnodes - wantfreevnodes); 904 goto alloc; 905 } 906 if (vnlruproc_sig == 0) { 907 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 908 wakeup(vnlruproc); 909 } 910 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 911 "vlruwk", hz); 912 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 913 if (numvnodes > desiredvnodes) { 914 mtx_unlock(&vnode_free_list_mtx); 915 return (ENFILE); 916 } 917 #endif 918 } 919 alloc: 920 numvnodes++; 921 mtx_unlock(&vnode_free_list_mtx); 922 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 923 /* 924 * Setup locks. 925 */ 926 vp->v_vnlock = &vp->v_lock; 927 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 928 /* 929 * By default, don't allow shared locks unless filesystems 930 * opt-in. 931 */ 932 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE); 933 /* 934 * Initialize bufobj. 935 */ 936 bo = &vp->v_bufobj; 937 bo->__bo_vnode = vp; 938 bo->bo_mtx = &vp->v_interlock; 939 bo->bo_ops = &buf_ops_bio; 940 bo->bo_private = vp; 941 TAILQ_INIT(&bo->bo_clean.bv_hd); 942 TAILQ_INIT(&bo->bo_dirty.bv_hd); 943 /* 944 * Initialize namecache. 945 */ 946 LIST_INIT(&vp->v_cache_src); 947 TAILQ_INIT(&vp->v_cache_dst); 948 /* 949 * Finalize various vnode identity bits. 950 */ 951 vp->v_type = VNON; 952 vp->v_tag = tag; 953 vp->v_op = vops; 954 v_incr_usecount(vp); 955 vp->v_data = 0; 956 #ifdef MAC 957 mac_vnode_init(vp); 958 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 959 mac_vnode_associate_singlelabel(mp, vp); 960 else if (mp == NULL) 961 printf("NULL mp in getnewvnode()\n"); 962 #endif 963 if (mp != NULL) { 964 bo->bo_bsize = mp->mnt_stat.f_iosize; 965 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 966 vp->v_vflag |= VV_NOKNOTE; 967 } 968 969 CTR2(KTR_VFS, "getnewvnode: mp %p vp %p", mp, vp); 970 *vpp = vp; 971 return (0); 972 } 973 974 /* 975 * Delete from old mount point vnode list, if on one. 976 */ 977 static void 978 delmntque(struct vnode *vp) 979 { 980 struct mount *mp; 981 982 mp = vp->v_mount; 983 if (mp == NULL) 984 return; 985 MNT_ILOCK(mp); 986 vp->v_mount = NULL; 987 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 988 ("bad mount point vnode list size")); 989 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 990 mp->mnt_nvnodelistsize--; 991 MNT_REL(mp); 992 MNT_IUNLOCK(mp); 993 } 994 995 static void 996 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 997 { 998 struct thread *td; 999 1000 td = curthread; /* XXX ? */ 1001 vp->v_data = NULL; 1002 vp->v_op = &dead_vnodeops; 1003 /* XXX non mp-safe fs may still call insmntque with vnode 1004 unlocked */ 1005 if (!VOP_ISLOCKED(vp, td)) 1006 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1007 vgone(vp); 1008 vput(vp); 1009 } 1010 1011 /* 1012 * Insert into list of vnodes for the new mount point, if available. 1013 */ 1014 int 1015 insmntque1(struct vnode *vp, struct mount *mp, 1016 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1017 { 1018 1019 KASSERT(vp->v_mount == NULL, 1020 ("insmntque: vnode already on per mount vnode list")); 1021 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1022 MNT_ILOCK(mp); 1023 if ((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1024 mp->mnt_nvnodelistsize == 0) { 1025 MNT_IUNLOCK(mp); 1026 if (dtr != NULL) 1027 dtr(vp, dtr_arg); 1028 return (EBUSY); 1029 } 1030 vp->v_mount = mp; 1031 MNT_REF(mp); 1032 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1033 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1034 ("neg mount point vnode list size")); 1035 mp->mnt_nvnodelistsize++; 1036 MNT_IUNLOCK(mp); 1037 return (0); 1038 } 1039 1040 int 1041 insmntque(struct vnode *vp, struct mount *mp) 1042 { 1043 1044 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1045 } 1046 1047 /* 1048 * Flush out and invalidate all buffers associated with a bufobj 1049 * Called with the underlying object locked. 1050 */ 1051 int 1052 bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag, 1053 int slptimeo) 1054 { 1055 int error; 1056 1057 BO_LOCK(bo); 1058 if (flags & V_SAVE) { 1059 error = bufobj_wwait(bo, slpflag, slptimeo); 1060 if (error) { 1061 BO_UNLOCK(bo); 1062 return (error); 1063 } 1064 if (bo->bo_dirty.bv_cnt > 0) { 1065 BO_UNLOCK(bo); 1066 if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0) 1067 return (error); 1068 /* 1069 * XXX We could save a lock/unlock if this was only 1070 * enabled under INVARIANTS 1071 */ 1072 BO_LOCK(bo); 1073 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1074 panic("vinvalbuf: dirty bufs"); 1075 } 1076 } 1077 /* 1078 * If you alter this loop please notice that interlock is dropped and 1079 * reacquired in flushbuflist. Special care is needed to ensure that 1080 * no race conditions occur from this. 1081 */ 1082 do { 1083 error = flushbuflist(&bo->bo_clean, 1084 flags, bo, slpflag, slptimeo); 1085 if (error == 0) 1086 error = flushbuflist(&bo->bo_dirty, 1087 flags, bo, slpflag, slptimeo); 1088 if (error != 0 && error != EAGAIN) { 1089 BO_UNLOCK(bo); 1090 return (error); 1091 } 1092 } while (error != 0); 1093 1094 /* 1095 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1096 * have write I/O in-progress but if there is a VM object then the 1097 * VM object can also have read-I/O in-progress. 1098 */ 1099 do { 1100 bufobj_wwait(bo, 0, 0); 1101 BO_UNLOCK(bo); 1102 if (bo->bo_object != NULL) { 1103 VM_OBJECT_LOCK(bo->bo_object); 1104 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1105 VM_OBJECT_UNLOCK(bo->bo_object); 1106 } 1107 BO_LOCK(bo); 1108 } while (bo->bo_numoutput > 0); 1109 BO_UNLOCK(bo); 1110 1111 /* 1112 * Destroy the copy in the VM cache, too. 1113 */ 1114 if (bo->bo_object != NULL) { 1115 VM_OBJECT_LOCK(bo->bo_object); 1116 vm_object_page_remove(bo->bo_object, 0, 0, 1117 (flags & V_SAVE) ? TRUE : FALSE); 1118 VM_OBJECT_UNLOCK(bo->bo_object); 1119 } 1120 1121 #ifdef INVARIANTS 1122 BO_LOCK(bo); 1123 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1124 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0)) 1125 panic("vinvalbuf: flush failed"); 1126 BO_UNLOCK(bo); 1127 #endif 1128 return (0); 1129 } 1130 1131 /* 1132 * Flush out and invalidate all buffers associated with a vnode. 1133 * Called with the underlying object locked. 1134 */ 1135 int 1136 vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag, 1137 int slptimeo) 1138 { 1139 1140 CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags); 1141 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1142 return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo)); 1143 } 1144 1145 /* 1146 * Flush out buffers on the specified list. 1147 * 1148 */ 1149 static int 1150 flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1151 int slptimeo) 1152 { 1153 struct buf *bp, *nbp; 1154 int retval, error; 1155 daddr_t lblkno; 1156 b_xflags_t xflags; 1157 1158 ASSERT_BO_LOCKED(bo); 1159 1160 retval = 0; 1161 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1162 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1163 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1164 continue; 1165 } 1166 lblkno = 0; 1167 xflags = 0; 1168 if (nbp != NULL) { 1169 lblkno = nbp->b_lblkno; 1170 xflags = nbp->b_xflags & 1171 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN); 1172 } 1173 retval = EAGAIN; 1174 error = BUF_TIMELOCK(bp, 1175 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo), 1176 "flushbuf", slpflag, slptimeo); 1177 if (error) { 1178 BO_LOCK(bo); 1179 return (error != ENOLCK ? error : EAGAIN); 1180 } 1181 KASSERT(bp->b_bufobj == bo, 1182 ("bp %p wrong b_bufobj %p should be %p", 1183 bp, bp->b_bufobj, bo)); 1184 if (bp->b_bufobj != bo) { /* XXX: necessary ? */ 1185 BUF_UNLOCK(bp); 1186 BO_LOCK(bo); 1187 return (EAGAIN); 1188 } 1189 /* 1190 * XXX Since there are no node locks for NFS, I 1191 * believe there is a slight chance that a delayed 1192 * write will occur while sleeping just above, so 1193 * check for it. 1194 */ 1195 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1196 (flags & V_SAVE)) { 1197 bremfree(bp); 1198 bp->b_flags |= B_ASYNC; 1199 bwrite(bp); 1200 BO_LOCK(bo); 1201 return (EAGAIN); /* XXX: why not loop ? */ 1202 } 1203 bremfree(bp); 1204 bp->b_flags |= (B_INVAL | B_RELBUF); 1205 bp->b_flags &= ~B_ASYNC; 1206 brelse(bp); 1207 BO_LOCK(bo); 1208 if (nbp != NULL && 1209 (nbp->b_bufobj != bo || 1210 nbp->b_lblkno != lblkno || 1211 (nbp->b_xflags & 1212 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags)) 1213 break; /* nbp invalid */ 1214 } 1215 return (retval); 1216 } 1217 1218 /* 1219 * Truncate a file's buffer and pages to a specified length. This 1220 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1221 * sync activity. 1222 */ 1223 int 1224 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td, 1225 off_t length, int blksize) 1226 { 1227 struct buf *bp, *nbp; 1228 int anyfreed; 1229 int trunclbn; 1230 struct bufobj *bo; 1231 1232 CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length); 1233 /* 1234 * Round up to the *next* lbn. 1235 */ 1236 trunclbn = (length + blksize - 1) / blksize; 1237 1238 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1239 restart: 1240 VI_LOCK(vp); 1241 bo = &vp->v_bufobj; 1242 anyfreed = 1; 1243 for (;anyfreed;) { 1244 anyfreed = 0; 1245 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1246 if (bp->b_lblkno < trunclbn) 1247 continue; 1248 if (BUF_LOCK(bp, 1249 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1250 VI_MTX(vp)) == ENOLCK) 1251 goto restart; 1252 1253 bremfree(bp); 1254 bp->b_flags |= (B_INVAL | B_RELBUF); 1255 bp->b_flags &= ~B_ASYNC; 1256 brelse(bp); 1257 anyfreed = 1; 1258 1259 if (nbp != NULL && 1260 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1261 (nbp->b_vp != vp) || 1262 (nbp->b_flags & B_DELWRI))) { 1263 goto restart; 1264 } 1265 VI_LOCK(vp); 1266 } 1267 1268 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1269 if (bp->b_lblkno < trunclbn) 1270 continue; 1271 if (BUF_LOCK(bp, 1272 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1273 VI_MTX(vp)) == ENOLCK) 1274 goto restart; 1275 bremfree(bp); 1276 bp->b_flags |= (B_INVAL | B_RELBUF); 1277 bp->b_flags &= ~B_ASYNC; 1278 brelse(bp); 1279 anyfreed = 1; 1280 if (nbp != NULL && 1281 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1282 (nbp->b_vp != vp) || 1283 (nbp->b_flags & B_DELWRI) == 0)) { 1284 goto restart; 1285 } 1286 VI_LOCK(vp); 1287 } 1288 } 1289 1290 if (length > 0) { 1291 restartsync: 1292 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1293 if (bp->b_lblkno > 0) 1294 continue; 1295 /* 1296 * Since we hold the vnode lock this should only 1297 * fail if we're racing with the buf daemon. 1298 */ 1299 if (BUF_LOCK(bp, 1300 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1301 VI_MTX(vp)) == ENOLCK) { 1302 goto restart; 1303 } 1304 VNASSERT((bp->b_flags & B_DELWRI), vp, 1305 ("buf(%p) on dirty queue without DELWRI", bp)); 1306 1307 bremfree(bp); 1308 bawrite(bp); 1309 VI_LOCK(vp); 1310 goto restartsync; 1311 } 1312 } 1313 1314 bufobj_wwait(bo, 0, 0); 1315 VI_UNLOCK(vp); 1316 vnode_pager_setsize(vp, length); 1317 1318 return (0); 1319 } 1320 1321 /* 1322 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1323 * a vnode. 1324 * 1325 * NOTE: We have to deal with the special case of a background bitmap 1326 * buffer, a situation where two buffers will have the same logical 1327 * block offset. We want (1) only the foreground buffer to be accessed 1328 * in a lookup and (2) must differentiate between the foreground and 1329 * background buffer in the splay tree algorithm because the splay 1330 * tree cannot normally handle multiple entities with the same 'index'. 1331 * We accomplish this by adding differentiating flags to the splay tree's 1332 * numerical domain. 1333 */ 1334 static 1335 struct buf * 1336 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1337 { 1338 struct buf dummy; 1339 struct buf *lefttreemax, *righttreemin, *y; 1340 1341 if (root == NULL) 1342 return (NULL); 1343 lefttreemax = righttreemin = &dummy; 1344 for (;;) { 1345 if (lblkno < root->b_lblkno || 1346 (lblkno == root->b_lblkno && 1347 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1348 if ((y = root->b_left) == NULL) 1349 break; 1350 if (lblkno < y->b_lblkno) { 1351 /* Rotate right. */ 1352 root->b_left = y->b_right; 1353 y->b_right = root; 1354 root = y; 1355 if ((y = root->b_left) == NULL) 1356 break; 1357 } 1358 /* Link into the new root's right tree. */ 1359 righttreemin->b_left = root; 1360 righttreemin = root; 1361 } else if (lblkno > root->b_lblkno || 1362 (lblkno == root->b_lblkno && 1363 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1364 if ((y = root->b_right) == NULL) 1365 break; 1366 if (lblkno > y->b_lblkno) { 1367 /* Rotate left. */ 1368 root->b_right = y->b_left; 1369 y->b_left = root; 1370 root = y; 1371 if ((y = root->b_right) == NULL) 1372 break; 1373 } 1374 /* Link into the new root's left tree. */ 1375 lefttreemax->b_right = root; 1376 lefttreemax = root; 1377 } else { 1378 break; 1379 } 1380 root = y; 1381 } 1382 /* Assemble the new root. */ 1383 lefttreemax->b_right = root->b_left; 1384 righttreemin->b_left = root->b_right; 1385 root->b_left = dummy.b_right; 1386 root->b_right = dummy.b_left; 1387 return (root); 1388 } 1389 1390 static void 1391 buf_vlist_remove(struct buf *bp) 1392 { 1393 struct buf *root; 1394 struct bufv *bv; 1395 1396 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1397 ASSERT_BO_LOCKED(bp->b_bufobj); 1398 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1399 (BX_VNDIRTY|BX_VNCLEAN), 1400 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1401 if (bp->b_xflags & BX_VNDIRTY) 1402 bv = &bp->b_bufobj->bo_dirty; 1403 else 1404 bv = &bp->b_bufobj->bo_clean; 1405 if (bp != bv->bv_root) { 1406 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1407 KASSERT(root == bp, ("splay lookup failed in remove")); 1408 } 1409 if (bp->b_left == NULL) { 1410 root = bp->b_right; 1411 } else { 1412 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1413 root->b_right = bp->b_right; 1414 } 1415 bv->bv_root = root; 1416 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1417 bv->bv_cnt--; 1418 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1419 } 1420 1421 /* 1422 * Add the buffer to the sorted clean or dirty block list using a 1423 * splay tree algorithm. 1424 * 1425 * NOTE: xflags is passed as a constant, optimizing this inline function! 1426 */ 1427 static void 1428 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1429 { 1430 struct buf *root; 1431 struct bufv *bv; 1432 1433 ASSERT_BO_LOCKED(bo); 1434 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1435 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1436 bp->b_xflags |= xflags; 1437 if (xflags & BX_VNDIRTY) 1438 bv = &bo->bo_dirty; 1439 else 1440 bv = &bo->bo_clean; 1441 1442 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1443 if (root == NULL) { 1444 bp->b_left = NULL; 1445 bp->b_right = NULL; 1446 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1447 } else if (bp->b_lblkno < root->b_lblkno || 1448 (bp->b_lblkno == root->b_lblkno && 1449 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1450 bp->b_left = root->b_left; 1451 bp->b_right = root; 1452 root->b_left = NULL; 1453 TAILQ_INSERT_BEFORE(root, bp, b_bobufs); 1454 } else { 1455 bp->b_right = root->b_right; 1456 bp->b_left = root; 1457 root->b_right = NULL; 1458 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs); 1459 } 1460 bv->bv_cnt++; 1461 bv->bv_root = bp; 1462 } 1463 1464 /* 1465 * Lookup a buffer using the splay tree. Note that we specifically avoid 1466 * shadow buffers used in background bitmap writes. 1467 * 1468 * This code isn't quite efficient as it could be because we are maintaining 1469 * two sorted lists and do not know which list the block resides in. 1470 * 1471 * During a "make buildworld" the desired buffer is found at one of 1472 * the roots more than 60% of the time. Thus, checking both roots 1473 * before performing either splay eliminates unnecessary splays on the 1474 * first tree splayed. 1475 */ 1476 struct buf * 1477 gbincore(struct bufobj *bo, daddr_t lblkno) 1478 { 1479 struct buf *bp; 1480 1481 ASSERT_BO_LOCKED(bo); 1482 if ((bp = bo->bo_clean.bv_root) != NULL && 1483 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1484 return (bp); 1485 if ((bp = bo->bo_dirty.bv_root) != NULL && 1486 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1487 return (bp); 1488 if ((bp = bo->bo_clean.bv_root) != NULL) { 1489 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp); 1490 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1491 return (bp); 1492 } 1493 if ((bp = bo->bo_dirty.bv_root) != NULL) { 1494 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp); 1495 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1496 return (bp); 1497 } 1498 return (NULL); 1499 } 1500 1501 /* 1502 * Associate a buffer with a vnode. 1503 */ 1504 void 1505 bgetvp(struct vnode *vp, struct buf *bp) 1506 { 1507 1508 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 1509 1510 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 1511 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 1512 ("bgetvp: bp already attached! %p", bp)); 1513 1514 ASSERT_VI_LOCKED(vp, "bgetvp"); 1515 vholdl(vp); 1516 if (VFS_NEEDSGIANT(vp->v_mount) || 1517 vp->v_bufobj.bo_flag & BO_NEEDSGIANT) 1518 bp->b_flags |= B_NEEDSGIANT; 1519 bp->b_vp = vp; 1520 bp->b_bufobj = &vp->v_bufobj; 1521 /* 1522 * Insert onto list for new vnode. 1523 */ 1524 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN); 1525 } 1526 1527 /* 1528 * Disassociate a buffer from a vnode. 1529 */ 1530 void 1531 brelvp(struct buf *bp) 1532 { 1533 struct bufobj *bo; 1534 struct vnode *vp; 1535 1536 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 1537 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1538 1539 /* 1540 * Delete from old vnode list, if on one. 1541 */ 1542 vp = bp->b_vp; /* XXX */ 1543 bo = bp->b_bufobj; 1544 BO_LOCK(bo); 1545 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1546 buf_vlist_remove(bp); 1547 else 1548 panic("brelvp: Buffer %p not on queue.", bp); 1549 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1550 bo->bo_flag &= ~BO_ONWORKLST; 1551 mtx_lock(&sync_mtx); 1552 LIST_REMOVE(bo, bo_synclist); 1553 syncer_worklist_len--; 1554 mtx_unlock(&sync_mtx); 1555 } 1556 bp->b_flags &= ~B_NEEDSGIANT; 1557 bp->b_vp = NULL; 1558 bp->b_bufobj = NULL; 1559 vdropl(vp); 1560 } 1561 1562 /* 1563 * Add an item to the syncer work queue. 1564 */ 1565 static void 1566 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 1567 { 1568 int slot; 1569 1570 ASSERT_BO_LOCKED(bo); 1571 1572 mtx_lock(&sync_mtx); 1573 if (bo->bo_flag & BO_ONWORKLST) 1574 LIST_REMOVE(bo, bo_synclist); 1575 else { 1576 bo->bo_flag |= BO_ONWORKLST; 1577 syncer_worklist_len++; 1578 } 1579 1580 if (delay > syncer_maxdelay - 2) 1581 delay = syncer_maxdelay - 2; 1582 slot = (syncer_delayno + delay) & syncer_mask; 1583 1584 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 1585 mtx_unlock(&sync_mtx); 1586 } 1587 1588 static int 1589 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1590 { 1591 int error, len; 1592 1593 mtx_lock(&sync_mtx); 1594 len = syncer_worklist_len - sync_vnode_count; 1595 mtx_unlock(&sync_mtx); 1596 error = SYSCTL_OUT(req, &len, sizeof(len)); 1597 return (error); 1598 } 1599 1600 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1601 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1602 1603 static struct proc *updateproc; 1604 static void sched_sync(void); 1605 static struct kproc_desc up_kp = { 1606 "syncer", 1607 sched_sync, 1608 &updateproc 1609 }; 1610 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1611 1612 static int 1613 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 1614 { 1615 struct vnode *vp; 1616 struct mount *mp; 1617 int vfslocked; 1618 1619 vfslocked = 0; 1620 restart: 1621 *bo = LIST_FIRST(slp); 1622 if (*bo == NULL) { 1623 VFS_UNLOCK_GIANT(vfslocked); 1624 return (0); 1625 } 1626 vp = (*bo)->__bo_vnode; /* XXX */ 1627 if (VFS_NEEDSGIANT(vp->v_mount)) { 1628 if (!vfslocked) { 1629 vfslocked = 1; 1630 if (mtx_trylock(&Giant) == 0) { 1631 mtx_unlock(&sync_mtx); 1632 mtx_lock(&Giant); 1633 mtx_lock(&sync_mtx); 1634 goto restart; 1635 } 1636 } 1637 } else { 1638 VFS_UNLOCK_GIANT(vfslocked); 1639 vfslocked = 0; 1640 } 1641 if (VOP_ISLOCKED(vp, NULL) != 0) { 1642 VFS_UNLOCK_GIANT(vfslocked); 1643 return (1); 1644 } 1645 if (VI_TRYLOCK(vp) == 0) { 1646 VFS_UNLOCK_GIANT(vfslocked); 1647 return (1); 1648 } 1649 /* 1650 * We use vhold in case the vnode does not 1651 * successfully sync. vhold prevents the vnode from 1652 * going away when we unlock the sync_mtx so that 1653 * we can acquire the vnode interlock. 1654 */ 1655 vholdl(vp); 1656 mtx_unlock(&sync_mtx); 1657 VI_UNLOCK(vp); 1658 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1659 vdrop(vp); 1660 VFS_UNLOCK_GIANT(vfslocked); 1661 mtx_lock(&sync_mtx); 1662 return (1); 1663 } 1664 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1665 (void) VOP_FSYNC(vp, MNT_LAZY, td); 1666 VOP_UNLOCK(vp, 0); 1667 vn_finished_write(mp); 1668 VI_LOCK(vp); 1669 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 1670 /* 1671 * Put us back on the worklist. The worklist 1672 * routine will remove us from our current 1673 * position and then add us back in at a later 1674 * position. 1675 */ 1676 vn_syncer_add_to_worklist(*bo, syncdelay); 1677 } 1678 vdropl(vp); 1679 VFS_UNLOCK_GIANT(vfslocked); 1680 mtx_lock(&sync_mtx); 1681 return (0); 1682 } 1683 1684 /* 1685 * System filesystem synchronizer daemon. 1686 */ 1687 static void 1688 sched_sync(void) 1689 { 1690 struct synclist *next; 1691 struct synclist *slp; 1692 struct bufobj *bo; 1693 long starttime; 1694 struct thread *td = curthread; 1695 static int dummychan; 1696 int last_work_seen; 1697 int net_worklist_len; 1698 int syncer_final_iter; 1699 int first_printf; 1700 int error; 1701 1702 last_work_seen = 0; 1703 syncer_final_iter = 0; 1704 first_printf = 1; 1705 syncer_state = SYNCER_RUNNING; 1706 starttime = time_uptime; 1707 td->td_pflags |= TDP_NORUNNINGBUF; 1708 1709 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 1710 SHUTDOWN_PRI_LAST); 1711 1712 mtx_lock(&sync_mtx); 1713 for (;;) { 1714 if (syncer_state == SYNCER_FINAL_DELAY && 1715 syncer_final_iter == 0) { 1716 mtx_unlock(&sync_mtx); 1717 kproc_suspend_check(td->td_proc); 1718 mtx_lock(&sync_mtx); 1719 } 1720 net_worklist_len = syncer_worklist_len - sync_vnode_count; 1721 if (syncer_state != SYNCER_RUNNING && 1722 starttime != time_uptime) { 1723 if (first_printf) { 1724 printf("\nSyncing disks, vnodes remaining..."); 1725 first_printf = 0; 1726 } 1727 printf("%d ", net_worklist_len); 1728 } 1729 starttime = time_uptime; 1730 1731 /* 1732 * Push files whose dirty time has expired. Be careful 1733 * of interrupt race on slp queue. 1734 * 1735 * Skip over empty worklist slots when shutting down. 1736 */ 1737 do { 1738 slp = &syncer_workitem_pending[syncer_delayno]; 1739 syncer_delayno += 1; 1740 if (syncer_delayno == syncer_maxdelay) 1741 syncer_delayno = 0; 1742 next = &syncer_workitem_pending[syncer_delayno]; 1743 /* 1744 * If the worklist has wrapped since the 1745 * it was emptied of all but syncer vnodes, 1746 * switch to the FINAL_DELAY state and run 1747 * for one more second. 1748 */ 1749 if (syncer_state == SYNCER_SHUTTING_DOWN && 1750 net_worklist_len == 0 && 1751 last_work_seen == syncer_delayno) { 1752 syncer_state = SYNCER_FINAL_DELAY; 1753 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 1754 } 1755 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 1756 syncer_worklist_len > 0); 1757 1758 /* 1759 * Keep track of the last time there was anything 1760 * on the worklist other than syncer vnodes. 1761 * Return to the SHUTTING_DOWN state if any 1762 * new work appears. 1763 */ 1764 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 1765 last_work_seen = syncer_delayno; 1766 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 1767 syncer_state = SYNCER_SHUTTING_DOWN; 1768 while (!LIST_EMPTY(slp)) { 1769 error = sync_vnode(slp, &bo, td); 1770 if (error == 1) { 1771 LIST_REMOVE(bo, bo_synclist); 1772 LIST_INSERT_HEAD(next, bo, bo_synclist); 1773 continue; 1774 } 1775 } 1776 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 1777 syncer_final_iter--; 1778 /* 1779 * The variable rushjob allows the kernel to speed up the 1780 * processing of the filesystem syncer process. A rushjob 1781 * value of N tells the filesystem syncer to process the next 1782 * N seconds worth of work on its queue ASAP. Currently rushjob 1783 * is used by the soft update code to speed up the filesystem 1784 * syncer process when the incore state is getting so far 1785 * ahead of the disk that the kernel memory pool is being 1786 * threatened with exhaustion. 1787 */ 1788 if (rushjob > 0) { 1789 rushjob -= 1; 1790 continue; 1791 } 1792 /* 1793 * Just sleep for a short period of time between 1794 * iterations when shutting down to allow some I/O 1795 * to happen. 1796 * 1797 * If it has taken us less than a second to process the 1798 * current work, then wait. Otherwise start right over 1799 * again. We can still lose time if any single round 1800 * takes more than two seconds, but it does not really 1801 * matter as we are just trying to generally pace the 1802 * filesystem activity. 1803 */ 1804 if (syncer_state != SYNCER_RUNNING) 1805 msleep(&dummychan, &sync_mtx, PPAUSE, "syncfnl", 1806 hz / SYNCER_SHUTDOWN_SPEEDUP); 1807 else if (time_uptime == starttime) 1808 msleep(&lbolt, &sync_mtx, PPAUSE, "syncer", 0); 1809 } 1810 } 1811 1812 /* 1813 * Request the syncer daemon to speed up its work. 1814 * We never push it to speed up more than half of its 1815 * normal turn time, otherwise it could take over the cpu. 1816 */ 1817 int 1818 speedup_syncer(void) 1819 { 1820 struct thread *td; 1821 int ret = 0; 1822 1823 td = FIRST_THREAD_IN_PROC(updateproc); 1824 mtx_lock(&sync_mtx); 1825 if (rushjob < syncdelay / 2) { 1826 rushjob += 1; 1827 stat_rush_requests += 1; 1828 ret = 1; 1829 } 1830 mtx_unlock(&sync_mtx); 1831 sleepq_remove(td, &lbolt); 1832 return (ret); 1833 } 1834 1835 /* 1836 * Tell the syncer to speed up its work and run though its work 1837 * list several times, then tell it to shut down. 1838 */ 1839 static void 1840 syncer_shutdown(void *arg, int howto) 1841 { 1842 struct thread *td; 1843 1844 if (howto & RB_NOSYNC) 1845 return; 1846 td = FIRST_THREAD_IN_PROC(updateproc); 1847 mtx_lock(&sync_mtx); 1848 syncer_state = SYNCER_SHUTTING_DOWN; 1849 rushjob = 0; 1850 mtx_unlock(&sync_mtx); 1851 sleepq_remove(td, &lbolt); 1852 kproc_shutdown(arg, howto); 1853 } 1854 1855 /* 1856 * Reassign a buffer from one vnode to another. 1857 * Used to assign file specific control information 1858 * (indirect blocks) to the vnode to which they belong. 1859 */ 1860 void 1861 reassignbuf(struct buf *bp) 1862 { 1863 struct vnode *vp; 1864 struct bufobj *bo; 1865 int delay; 1866 #ifdef INVARIANTS 1867 struct bufv *bv; 1868 #endif 1869 1870 vp = bp->b_vp; 1871 bo = bp->b_bufobj; 1872 ++reassignbufcalls; 1873 1874 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 1875 bp, bp->b_vp, bp->b_flags); 1876 /* 1877 * B_PAGING flagged buffers cannot be reassigned because their vp 1878 * is not fully linked in. 1879 */ 1880 if (bp->b_flags & B_PAGING) 1881 panic("cannot reassign paging buffer"); 1882 1883 /* 1884 * Delete from old vnode list, if on one. 1885 */ 1886 VI_LOCK(vp); 1887 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1888 buf_vlist_remove(bp); 1889 else 1890 panic("reassignbuf: Buffer %p not on queue.", bp); 1891 /* 1892 * If dirty, put on list of dirty buffers; otherwise insert onto list 1893 * of clean buffers. 1894 */ 1895 if (bp->b_flags & B_DELWRI) { 1896 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 1897 switch (vp->v_type) { 1898 case VDIR: 1899 delay = dirdelay; 1900 break; 1901 case VCHR: 1902 delay = metadelay; 1903 break; 1904 default: 1905 delay = filedelay; 1906 } 1907 vn_syncer_add_to_worklist(bo, delay); 1908 } 1909 buf_vlist_add(bp, bo, BX_VNDIRTY); 1910 } else { 1911 buf_vlist_add(bp, bo, BX_VNCLEAN); 1912 1913 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1914 mtx_lock(&sync_mtx); 1915 LIST_REMOVE(bo, bo_synclist); 1916 syncer_worklist_len--; 1917 mtx_unlock(&sync_mtx); 1918 bo->bo_flag &= ~BO_ONWORKLST; 1919 } 1920 } 1921 #ifdef INVARIANTS 1922 bv = &bo->bo_clean; 1923 bp = TAILQ_FIRST(&bv->bv_hd); 1924 KASSERT(bp == NULL || bp->b_bufobj == bo, 1925 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1926 bp = TAILQ_LAST(&bv->bv_hd, buflists); 1927 KASSERT(bp == NULL || bp->b_bufobj == bo, 1928 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1929 bv = &bo->bo_dirty; 1930 bp = TAILQ_FIRST(&bv->bv_hd); 1931 KASSERT(bp == NULL || bp->b_bufobj == bo, 1932 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1933 bp = TAILQ_LAST(&bv->bv_hd, buflists); 1934 KASSERT(bp == NULL || bp->b_bufobj == bo, 1935 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1936 #endif 1937 VI_UNLOCK(vp); 1938 } 1939 1940 /* 1941 * Increment the use and hold counts on the vnode, taking care to reference 1942 * the driver's usecount if this is a chardev. The vholdl() will remove 1943 * the vnode from the free list if it is presently free. Requires the 1944 * vnode interlock and returns with it held. 1945 */ 1946 static void 1947 v_incr_usecount(struct vnode *vp) 1948 { 1949 1950 CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n", 1951 vp, vp->v_holdcnt, vp->v_usecount); 1952 vp->v_usecount++; 1953 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1954 dev_lock(); 1955 vp->v_rdev->si_usecount++; 1956 dev_unlock(); 1957 } 1958 vholdl(vp); 1959 } 1960 1961 /* 1962 * Turn a holdcnt into a use+holdcnt such that only one call to 1963 * v_decr_usecount is needed. 1964 */ 1965 static void 1966 v_upgrade_usecount(struct vnode *vp) 1967 { 1968 1969 CTR3(KTR_VFS, "v_upgrade_usecount: vp %p holdcnt %d usecount %d\n", 1970 vp, vp->v_holdcnt, vp->v_usecount); 1971 vp->v_usecount++; 1972 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1973 dev_lock(); 1974 vp->v_rdev->si_usecount++; 1975 dev_unlock(); 1976 } 1977 } 1978 1979 /* 1980 * Decrement the vnode use and hold count along with the driver's usecount 1981 * if this is a chardev. The vdropl() below releases the vnode interlock 1982 * as it may free the vnode. 1983 */ 1984 static void 1985 v_decr_usecount(struct vnode *vp) 1986 { 1987 1988 CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n", 1989 vp, vp->v_holdcnt, vp->v_usecount); 1990 ASSERT_VI_LOCKED(vp, __FUNCTION__); 1991 VNASSERT(vp->v_usecount > 0, vp, 1992 ("v_decr_usecount: negative usecount")); 1993 vp->v_usecount--; 1994 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1995 dev_lock(); 1996 vp->v_rdev->si_usecount--; 1997 dev_unlock(); 1998 } 1999 vdropl(vp); 2000 } 2001 2002 /* 2003 * Decrement only the use count and driver use count. This is intended to 2004 * be paired with a follow on vdropl() to release the remaining hold count. 2005 * In this way we may vgone() a vnode with a 0 usecount without risk of 2006 * having it end up on a free list because the hold count is kept above 0. 2007 */ 2008 static void 2009 v_decr_useonly(struct vnode *vp) 2010 { 2011 2012 CTR3(KTR_VFS, "v_decr_useonly: vp %p holdcnt %d usecount %d\n", 2013 vp, vp->v_holdcnt, vp->v_usecount); 2014 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2015 VNASSERT(vp->v_usecount > 0, vp, 2016 ("v_decr_useonly: negative usecount")); 2017 vp->v_usecount--; 2018 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2019 dev_lock(); 2020 vp->v_rdev->si_usecount--; 2021 dev_unlock(); 2022 } 2023 } 2024 2025 /* 2026 * Grab a particular vnode from the free list, increment its 2027 * reference count and lock it. The vnode lock bit is set if the 2028 * vnode is being eliminated in vgone. The process is awakened 2029 * when the transition is completed, and an error returned to 2030 * indicate that the vnode is no longer usable (possibly having 2031 * been changed to a new filesystem type). 2032 */ 2033 int 2034 vget(struct vnode *vp, int flags, struct thread *td) 2035 { 2036 int oweinact; 2037 int oldflags; 2038 int error; 2039 2040 error = 0; 2041 oldflags = flags; 2042 oweinact = 0; 2043 VFS_ASSERT_GIANT(vp->v_mount); 2044 if ((flags & LK_INTERLOCK) == 0) 2045 VI_LOCK(vp); 2046 /* 2047 * If the inactive call was deferred because vput() was called 2048 * with a shared lock, we have to do it here before another thread 2049 * gets a reference to data that should be dead. 2050 */ 2051 if (vp->v_iflag & VI_OWEINACT) { 2052 if (flags & LK_NOWAIT) { 2053 VI_UNLOCK(vp); 2054 return (EBUSY); 2055 } 2056 flags &= ~LK_TYPE_MASK; 2057 flags |= LK_EXCLUSIVE; 2058 oweinact = 1; 2059 } 2060 vholdl(vp); 2061 if ((error = vn_lock(vp, flags | LK_INTERLOCK)) != 0) { 2062 vdrop(vp); 2063 return (error); 2064 } 2065 VI_LOCK(vp); 2066 /* Upgrade our holdcnt to a usecount. */ 2067 v_upgrade_usecount(vp); 2068 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2069 panic("vget: vn_lock failed to return ENOENT\n"); 2070 if (oweinact) { 2071 if (vp->v_iflag & VI_OWEINACT) 2072 vinactive(vp, td); 2073 VI_UNLOCK(vp); 2074 if ((oldflags & LK_TYPE_MASK) == 0) 2075 VOP_UNLOCK(vp, 0); 2076 } else 2077 VI_UNLOCK(vp); 2078 return (0); 2079 } 2080 2081 /* 2082 * Increase the reference count of a vnode. 2083 */ 2084 void 2085 vref(struct vnode *vp) 2086 { 2087 2088 VI_LOCK(vp); 2089 v_incr_usecount(vp); 2090 VI_UNLOCK(vp); 2091 } 2092 2093 /* 2094 * Return reference count of a vnode. 2095 * 2096 * The results of this call are only guaranteed when some mechanism other 2097 * than the VI lock is used to stop other processes from gaining references 2098 * to the vnode. This may be the case if the caller holds the only reference. 2099 * This is also useful when stale data is acceptable as race conditions may 2100 * be accounted for by some other means. 2101 */ 2102 int 2103 vrefcnt(struct vnode *vp) 2104 { 2105 int usecnt; 2106 2107 VI_LOCK(vp); 2108 usecnt = vp->v_usecount; 2109 VI_UNLOCK(vp); 2110 2111 return (usecnt); 2112 } 2113 2114 2115 /* 2116 * Vnode put/release. 2117 * If count drops to zero, call inactive routine and return to freelist. 2118 */ 2119 void 2120 vrele(struct vnode *vp) 2121 { 2122 struct thread *td = curthread; /* XXX */ 2123 2124 KASSERT(vp != NULL, ("vrele: null vp")); 2125 VFS_ASSERT_GIANT(vp->v_mount); 2126 2127 VI_LOCK(vp); 2128 2129 /* Skip this v_writecount check if we're going to panic below. */ 2130 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2131 ("vrele: missed vn_close")); 2132 2133 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2134 vp->v_usecount == 1)) { 2135 v_decr_usecount(vp); 2136 return; 2137 } 2138 if (vp->v_usecount != 1) { 2139 #ifdef DIAGNOSTIC 2140 vprint("vrele: negative ref count", vp); 2141 #endif 2142 VI_UNLOCK(vp); 2143 panic("vrele: negative ref cnt"); 2144 } 2145 /* 2146 * We want to hold the vnode until the inactive finishes to 2147 * prevent vgone() races. We drop the use count here and the 2148 * hold count below when we're done. 2149 */ 2150 v_decr_useonly(vp); 2151 /* 2152 * We must call VOP_INACTIVE with the node locked. Mark 2153 * as VI_DOINGINACT to avoid recursion. 2154 */ 2155 vp->v_iflag |= VI_OWEINACT; 2156 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK) == 0) { 2157 VI_LOCK(vp); 2158 if (vp->v_usecount > 0) 2159 vp->v_iflag &= ~VI_OWEINACT; 2160 if (vp->v_iflag & VI_OWEINACT) 2161 vinactive(vp, td); 2162 VOP_UNLOCK(vp, 0); 2163 } else { 2164 VI_LOCK(vp); 2165 if (vp->v_usecount > 0) 2166 vp->v_iflag &= ~VI_OWEINACT; 2167 } 2168 vdropl(vp); 2169 } 2170 2171 /* 2172 * Release an already locked vnode. This give the same effects as 2173 * unlock+vrele(), but takes less time and avoids releasing and 2174 * re-aquiring the lock (as vrele() acquires the lock internally.) 2175 */ 2176 void 2177 vput(struct vnode *vp) 2178 { 2179 struct thread *td = curthread; /* XXX */ 2180 int error; 2181 2182 KASSERT(vp != NULL, ("vput: null vp")); 2183 ASSERT_VOP_LOCKED(vp, "vput"); 2184 VFS_ASSERT_GIANT(vp->v_mount); 2185 VI_LOCK(vp); 2186 /* Skip this v_writecount check if we're going to panic below. */ 2187 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2188 ("vput: missed vn_close")); 2189 error = 0; 2190 2191 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2192 vp->v_usecount == 1)) { 2193 VOP_UNLOCK(vp, 0); 2194 v_decr_usecount(vp); 2195 return; 2196 } 2197 2198 if (vp->v_usecount != 1) { 2199 #ifdef DIAGNOSTIC 2200 vprint("vput: negative ref count", vp); 2201 #endif 2202 panic("vput: negative ref cnt"); 2203 } 2204 /* 2205 * We want to hold the vnode until the inactive finishes to 2206 * prevent vgone() races. We drop the use count here and the 2207 * hold count below when we're done. 2208 */ 2209 v_decr_useonly(vp); 2210 vp->v_iflag |= VI_OWEINACT; 2211 if (VOP_ISLOCKED(vp, NULL) != LK_EXCLUSIVE) { 2212 error = VOP_LOCK(vp, LK_UPGRADE|LK_INTERLOCK|LK_NOWAIT); 2213 VI_LOCK(vp); 2214 if (error) { 2215 if (vp->v_usecount > 0) 2216 vp->v_iflag &= ~VI_OWEINACT; 2217 goto done; 2218 } 2219 } 2220 if (vp->v_usecount > 0) 2221 vp->v_iflag &= ~VI_OWEINACT; 2222 if (vp->v_iflag & VI_OWEINACT) 2223 vinactive(vp, td); 2224 VOP_UNLOCK(vp, 0); 2225 done: 2226 vdropl(vp); 2227 } 2228 2229 /* 2230 * Somebody doesn't want the vnode recycled. 2231 */ 2232 void 2233 vhold(struct vnode *vp) 2234 { 2235 2236 VI_LOCK(vp); 2237 vholdl(vp); 2238 VI_UNLOCK(vp); 2239 } 2240 2241 void 2242 vholdl(struct vnode *vp) 2243 { 2244 2245 vp->v_holdcnt++; 2246 if (VSHOULDBUSY(vp)) 2247 vbusy(vp); 2248 } 2249 2250 /* 2251 * Note that there is one less who cares about this vnode. vdrop() is the 2252 * opposite of vhold(). 2253 */ 2254 void 2255 vdrop(struct vnode *vp) 2256 { 2257 2258 VI_LOCK(vp); 2259 vdropl(vp); 2260 } 2261 2262 /* 2263 * Drop the hold count of the vnode. If this is the last reference to 2264 * the vnode we will free it if it has been vgone'd otherwise it is 2265 * placed on the free list. 2266 */ 2267 void 2268 vdropl(struct vnode *vp) 2269 { 2270 2271 ASSERT_VI_LOCKED(vp, "vdropl"); 2272 if (vp->v_holdcnt <= 0) 2273 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2274 vp->v_holdcnt--; 2275 if (vp->v_holdcnt == 0) { 2276 if (vp->v_iflag & VI_DOOMED) { 2277 vdestroy(vp); 2278 return; 2279 } else 2280 vfree(vp); 2281 } 2282 VI_UNLOCK(vp); 2283 } 2284 2285 /* 2286 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 2287 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 2288 * OWEINACT tracks whether a vnode missed a call to inactive due to a 2289 * failed lock upgrade. 2290 */ 2291 static void 2292 vinactive(struct vnode *vp, struct thread *td) 2293 { 2294 2295 ASSERT_VOP_LOCKED(vp, "vinactive"); 2296 ASSERT_VI_LOCKED(vp, "vinactive"); 2297 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 2298 ("vinactive: recursed on VI_DOINGINACT")); 2299 vp->v_iflag |= VI_DOINGINACT; 2300 vp->v_iflag &= ~VI_OWEINACT; 2301 VI_UNLOCK(vp); 2302 VOP_INACTIVE(vp, td); 2303 VI_LOCK(vp); 2304 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 2305 ("vinactive: lost VI_DOINGINACT")); 2306 vp->v_iflag &= ~VI_DOINGINACT; 2307 } 2308 2309 /* 2310 * Remove any vnodes in the vnode table belonging to mount point mp. 2311 * 2312 * If FORCECLOSE is not specified, there should not be any active ones, 2313 * return error if any are found (nb: this is a user error, not a 2314 * system error). If FORCECLOSE is specified, detach any active vnodes 2315 * that are found. 2316 * 2317 * If WRITECLOSE is set, only flush out regular file vnodes open for 2318 * writing. 2319 * 2320 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2321 * 2322 * `rootrefs' specifies the base reference count for the root vnode 2323 * of this filesystem. The root vnode is considered busy if its 2324 * v_usecount exceeds this value. On a successful return, vflush(, td) 2325 * will call vrele() on the root vnode exactly rootrefs times. 2326 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2327 * be zero. 2328 */ 2329 #ifdef DIAGNOSTIC 2330 static int busyprt = 0; /* print out busy vnodes */ 2331 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2332 #endif 2333 2334 int 2335 vflush( struct mount *mp, int rootrefs, int flags, struct thread *td) 2336 { 2337 struct vnode *vp, *mvp, *rootvp = NULL; 2338 struct vattr vattr; 2339 int busy = 0, error; 2340 2341 CTR1(KTR_VFS, "vflush: mp %p", mp); 2342 if (rootrefs > 0) { 2343 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2344 ("vflush: bad args")); 2345 /* 2346 * Get the filesystem root vnode. We can vput() it 2347 * immediately, since with rootrefs > 0, it won't go away. 2348 */ 2349 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp, td)) != 0) 2350 return (error); 2351 vput(rootvp); 2352 2353 } 2354 MNT_ILOCK(mp); 2355 loop: 2356 MNT_VNODE_FOREACH(vp, mp, mvp) { 2357 2358 VI_LOCK(vp); 2359 vholdl(vp); 2360 MNT_IUNLOCK(mp); 2361 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 2362 if (error) { 2363 vdrop(vp); 2364 MNT_ILOCK(mp); 2365 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp); 2366 goto loop; 2367 } 2368 /* 2369 * Skip over a vnodes marked VV_SYSTEM. 2370 */ 2371 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2372 VOP_UNLOCK(vp, 0); 2373 vdrop(vp); 2374 MNT_ILOCK(mp); 2375 continue; 2376 } 2377 /* 2378 * If WRITECLOSE is set, flush out unlinked but still open 2379 * files (even if open only for reading) and regular file 2380 * vnodes open for writing. 2381 */ 2382 if (flags & WRITECLOSE) { 2383 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2384 VI_LOCK(vp); 2385 2386 if ((vp->v_type == VNON || 2387 (error == 0 && vattr.va_nlink > 0)) && 2388 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2389 VOP_UNLOCK(vp, 0); 2390 vdropl(vp); 2391 MNT_ILOCK(mp); 2392 continue; 2393 } 2394 } else 2395 VI_LOCK(vp); 2396 /* 2397 * With v_usecount == 0, all we need to do is clear out the 2398 * vnode data structures and we are done. 2399 * 2400 * If FORCECLOSE is set, forcibly close the vnode. 2401 */ 2402 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 2403 VNASSERT(vp->v_usecount == 0 || 2404 (vp->v_type != VCHR && vp->v_type != VBLK), vp, 2405 ("device VNODE %p is FORCECLOSED", vp)); 2406 vgonel(vp); 2407 } else { 2408 busy++; 2409 #ifdef DIAGNOSTIC 2410 if (busyprt) 2411 vprint("vflush: busy vnode", vp); 2412 #endif 2413 } 2414 VOP_UNLOCK(vp, 0); 2415 vdropl(vp); 2416 MNT_ILOCK(mp); 2417 } 2418 MNT_IUNLOCK(mp); 2419 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2420 /* 2421 * If just the root vnode is busy, and if its refcount 2422 * is equal to `rootrefs', then go ahead and kill it. 2423 */ 2424 VI_LOCK(rootvp); 2425 KASSERT(busy > 0, ("vflush: not busy")); 2426 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 2427 ("vflush: usecount %d < rootrefs %d", 2428 rootvp->v_usecount, rootrefs)); 2429 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2430 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 2431 vgone(rootvp); 2432 VOP_UNLOCK(rootvp, 0); 2433 busy = 0; 2434 } else 2435 VI_UNLOCK(rootvp); 2436 } 2437 if (busy) 2438 return (EBUSY); 2439 for (; rootrefs > 0; rootrefs--) 2440 vrele(rootvp); 2441 return (0); 2442 } 2443 2444 /* 2445 * Recycle an unused vnode to the front of the free list. 2446 */ 2447 int 2448 vrecycle(struct vnode *vp, struct thread *td) 2449 { 2450 int recycled; 2451 2452 ASSERT_VOP_LOCKED(vp, "vrecycle"); 2453 recycled = 0; 2454 VI_LOCK(vp); 2455 if (vp->v_usecount == 0) { 2456 recycled = 1; 2457 vgonel(vp); 2458 } 2459 VI_UNLOCK(vp); 2460 return (recycled); 2461 } 2462 2463 /* 2464 * Eliminate all activity associated with a vnode 2465 * in preparation for reuse. 2466 */ 2467 void 2468 vgone(struct vnode *vp) 2469 { 2470 VI_LOCK(vp); 2471 vgonel(vp); 2472 VI_UNLOCK(vp); 2473 } 2474 2475 /* 2476 * vgone, with the vp interlock held. 2477 */ 2478 void 2479 vgonel(struct vnode *vp) 2480 { 2481 struct thread *td; 2482 int oweinact; 2483 int active; 2484 struct mount *mp; 2485 2486 CTR1(KTR_VFS, "vgonel: vp %p", vp); 2487 ASSERT_VOP_LOCKED(vp, "vgonel"); 2488 ASSERT_VI_LOCKED(vp, "vgonel"); 2489 VNASSERT(vp->v_holdcnt, vp, 2490 ("vgonel: vp %p has no reference.", vp)); 2491 td = curthread; 2492 2493 /* 2494 * Don't vgonel if we're already doomed. 2495 */ 2496 if (vp->v_iflag & VI_DOOMED) 2497 return; 2498 vp->v_iflag |= VI_DOOMED; 2499 /* 2500 * Check to see if the vnode is in use. If so, we have to call 2501 * VOP_CLOSE() and VOP_INACTIVE(). 2502 */ 2503 active = vp->v_usecount; 2504 oweinact = (vp->v_iflag & VI_OWEINACT); 2505 VI_UNLOCK(vp); 2506 /* 2507 * Clean out any buffers associated with the vnode. 2508 * If the flush fails, just toss the buffers. 2509 */ 2510 mp = NULL; 2511 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 2512 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 2513 if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0) 2514 vinvalbuf(vp, 0, td, 0, 0); 2515 2516 /* 2517 * If purging an active vnode, it must be closed and 2518 * deactivated before being reclaimed. 2519 */ 2520 if (active) 2521 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2522 if (oweinact || active) { 2523 VI_LOCK(vp); 2524 if ((vp->v_iflag & VI_DOINGINACT) == 0) 2525 vinactive(vp, td); 2526 VI_UNLOCK(vp); 2527 } 2528 /* 2529 * Reclaim the vnode. 2530 */ 2531 if (VOP_RECLAIM(vp, td)) 2532 panic("vgone: cannot reclaim"); 2533 if (mp != NULL) 2534 vn_finished_secondary_write(mp); 2535 VNASSERT(vp->v_object == NULL, vp, 2536 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 2537 /* 2538 * Delete from old mount point vnode list. 2539 */ 2540 delmntque(vp); 2541 cache_purge(vp); 2542 /* 2543 * Done with purge, reset to the standard lock and invalidate 2544 * the vnode. 2545 */ 2546 VI_LOCK(vp); 2547 vp->v_vnlock = &vp->v_lock; 2548 vp->v_op = &dead_vnodeops; 2549 vp->v_tag = "none"; 2550 vp->v_type = VBAD; 2551 } 2552 2553 /* 2554 * Calculate the total number of references to a special device. 2555 */ 2556 int 2557 vcount(struct vnode *vp) 2558 { 2559 int count; 2560 2561 dev_lock(); 2562 count = vp->v_rdev->si_usecount; 2563 dev_unlock(); 2564 return (count); 2565 } 2566 2567 /* 2568 * Same as above, but using the struct cdev *as argument 2569 */ 2570 int 2571 count_dev(struct cdev *dev) 2572 { 2573 int count; 2574 2575 dev_lock(); 2576 count = dev->si_usecount; 2577 dev_unlock(); 2578 return(count); 2579 } 2580 2581 /* 2582 * Print out a description of a vnode. 2583 */ 2584 static char *typename[] = 2585 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 2586 "VMARKER"}; 2587 2588 void 2589 vn_printf(struct vnode *vp, const char *fmt, ...) 2590 { 2591 va_list ap; 2592 char buf[256], buf2[16]; 2593 u_long flags; 2594 2595 va_start(ap, fmt); 2596 vprintf(fmt, ap); 2597 va_end(ap); 2598 printf("%p: ", (void *)vp); 2599 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 2600 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 2601 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 2602 buf[0] = '\0'; 2603 buf[1] = '\0'; 2604 if (vp->v_vflag & VV_ROOT) 2605 strlcat(buf, "|VV_ROOT", sizeof(buf)); 2606 if (vp->v_vflag & VV_ISTTY) 2607 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 2608 if (vp->v_vflag & VV_NOSYNC) 2609 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 2610 if (vp->v_vflag & VV_CACHEDLABEL) 2611 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 2612 if (vp->v_vflag & VV_TEXT) 2613 strlcat(buf, "|VV_TEXT", sizeof(buf)); 2614 if (vp->v_vflag & VV_COPYONWRITE) 2615 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 2616 if (vp->v_vflag & VV_SYSTEM) 2617 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 2618 if (vp->v_vflag & VV_PROCDEP) 2619 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 2620 if (vp->v_vflag & VV_NOKNOTE) 2621 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 2622 if (vp->v_vflag & VV_DELETED) 2623 strlcat(buf, "|VV_DELETED", sizeof(buf)); 2624 if (vp->v_vflag & VV_MD) 2625 strlcat(buf, "|VV_MD", sizeof(buf)); 2626 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | 2627 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 2628 VV_NOKNOTE | VV_DELETED | VV_MD); 2629 if (flags != 0) { 2630 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 2631 strlcat(buf, buf2, sizeof(buf)); 2632 } 2633 if (vp->v_iflag & VI_MOUNT) 2634 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 2635 if (vp->v_iflag & VI_AGE) 2636 strlcat(buf, "|VI_AGE", sizeof(buf)); 2637 if (vp->v_iflag & VI_DOOMED) 2638 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 2639 if (vp->v_iflag & VI_FREE) 2640 strlcat(buf, "|VI_FREE", sizeof(buf)); 2641 if (vp->v_iflag & VI_OBJDIRTY) 2642 strlcat(buf, "|VI_OBJDIRTY", sizeof(buf)); 2643 if (vp->v_iflag & VI_DOINGINACT) 2644 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 2645 if (vp->v_iflag & VI_OWEINACT) 2646 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 2647 flags = vp->v_iflag & ~(VI_MOUNT | VI_AGE | VI_DOOMED | VI_FREE | 2648 VI_OBJDIRTY | VI_DOINGINACT | VI_OWEINACT); 2649 if (flags != 0) { 2650 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 2651 strlcat(buf, buf2, sizeof(buf)); 2652 } 2653 printf(" flags (%s)\n", buf + 1); 2654 if (mtx_owned(VI_MTX(vp))) 2655 printf(" VI_LOCKed"); 2656 if (vp->v_object != NULL) 2657 printf(" v_object %p ref %d pages %d\n", 2658 vp->v_object, vp->v_object->ref_count, 2659 vp->v_object->resident_page_count); 2660 printf(" "); 2661 lockmgr_printinfo(vp->v_vnlock); 2662 printf("\n"); 2663 if (vp->v_data != NULL) 2664 VOP_PRINT(vp); 2665 } 2666 2667 #ifdef DDB 2668 /* 2669 * List all of the locked vnodes in the system. 2670 * Called when debugging the kernel. 2671 */ 2672 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2673 { 2674 struct mount *mp, *nmp; 2675 struct vnode *vp; 2676 2677 /* 2678 * Note: because this is DDB, we can't obey the locking semantics 2679 * for these structures, which means we could catch an inconsistent 2680 * state and dereference a nasty pointer. Not much to be done 2681 * about that. 2682 */ 2683 db_printf("Locked vnodes\n"); 2684 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2685 nmp = TAILQ_NEXT(mp, mnt_list); 2686 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2687 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp, NULL)) 2688 vprint("", vp); 2689 } 2690 nmp = TAILQ_NEXT(mp, mnt_list); 2691 } 2692 } 2693 2694 /* 2695 * Show details about the given vnode. 2696 */ 2697 DB_SHOW_COMMAND(vnode, db_show_vnode) 2698 { 2699 struct vnode *vp; 2700 2701 if (!have_addr) 2702 return; 2703 vp = (struct vnode *)addr; 2704 vn_printf(vp, "vnode "); 2705 } 2706 #endif /* DDB */ 2707 2708 /* 2709 * Fill in a struct xvfsconf based on a struct vfsconf. 2710 */ 2711 static void 2712 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2713 { 2714 2715 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2716 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2717 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2718 xvfsp->vfc_flags = vfsp->vfc_flags; 2719 /* 2720 * These are unused in userland, we keep them 2721 * to not break binary compatibility. 2722 */ 2723 xvfsp->vfc_vfsops = NULL; 2724 xvfsp->vfc_next = NULL; 2725 } 2726 2727 /* 2728 * Top level filesystem related information gathering. 2729 */ 2730 static int 2731 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2732 { 2733 struct vfsconf *vfsp; 2734 struct xvfsconf xvfsp; 2735 int error; 2736 2737 error = 0; 2738 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2739 bzero(&xvfsp, sizeof(xvfsp)); 2740 vfsconf2x(vfsp, &xvfsp); 2741 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); 2742 if (error) 2743 break; 2744 } 2745 return (error); 2746 } 2747 2748 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2749 "S,xvfsconf", "List of all configured filesystems"); 2750 2751 #ifndef BURN_BRIDGES 2752 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2753 2754 static int 2755 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2756 { 2757 int *name = (int *)arg1 - 1; /* XXX */ 2758 u_int namelen = arg2 + 1; /* XXX */ 2759 struct vfsconf *vfsp; 2760 struct xvfsconf xvfsp; 2761 2762 printf("WARNING: userland calling deprecated sysctl, " 2763 "please rebuild world\n"); 2764 2765 #if 1 || defined(COMPAT_PRELITE2) 2766 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2767 if (namelen == 1) 2768 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2769 #endif 2770 2771 switch (name[1]) { 2772 case VFS_MAXTYPENUM: 2773 if (namelen != 2) 2774 return (ENOTDIR); 2775 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2776 case VFS_CONF: 2777 if (namelen != 3) 2778 return (ENOTDIR); /* overloaded */ 2779 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 2780 if (vfsp->vfc_typenum == name[2]) 2781 break; 2782 if (vfsp == NULL) 2783 return (EOPNOTSUPP); 2784 bzero(&xvfsp, sizeof(xvfsp)); 2785 vfsconf2x(vfsp, &xvfsp); 2786 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2787 } 2788 return (EOPNOTSUPP); 2789 } 2790 2791 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, 2792 vfs_sysctl, "Generic filesystem"); 2793 2794 #if 1 || defined(COMPAT_PRELITE2) 2795 2796 static int 2797 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2798 { 2799 int error; 2800 struct vfsconf *vfsp; 2801 struct ovfsconf ovfs; 2802 2803 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2804 bzero(&ovfs, sizeof(ovfs)); 2805 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2806 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2807 ovfs.vfc_index = vfsp->vfc_typenum; 2808 ovfs.vfc_refcount = vfsp->vfc_refcount; 2809 ovfs.vfc_flags = vfsp->vfc_flags; 2810 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2811 if (error) 2812 return error; 2813 } 2814 return 0; 2815 } 2816 2817 #endif /* 1 || COMPAT_PRELITE2 */ 2818 #endif /* !BURN_BRIDGES */ 2819 2820 #define KINFO_VNODESLOP 10 2821 #ifdef notyet 2822 /* 2823 * Dump vnode list (via sysctl). 2824 */ 2825 /* ARGSUSED */ 2826 static int 2827 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2828 { 2829 struct xvnode *xvn; 2830 struct thread *td = req->td; 2831 struct mount *mp; 2832 struct vnode *vp; 2833 int error, len, n; 2834 2835 /* 2836 * Stale numvnodes access is not fatal here. 2837 */ 2838 req->lock = 0; 2839 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 2840 if (!req->oldptr) 2841 /* Make an estimate */ 2842 return (SYSCTL_OUT(req, 0, len)); 2843 2844 error = sysctl_wire_old_buffer(req, 0); 2845 if (error != 0) 2846 return (error); 2847 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 2848 n = 0; 2849 mtx_lock(&mountlist_mtx); 2850 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2851 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 2852 continue; 2853 MNT_ILOCK(mp); 2854 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2855 if (n == len) 2856 break; 2857 vref(vp); 2858 xvn[n].xv_size = sizeof *xvn; 2859 xvn[n].xv_vnode = vp; 2860 xvn[n].xv_id = 0; /* XXX compat */ 2861 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 2862 XV_COPY(usecount); 2863 XV_COPY(writecount); 2864 XV_COPY(holdcnt); 2865 XV_COPY(mount); 2866 XV_COPY(numoutput); 2867 XV_COPY(type); 2868 #undef XV_COPY 2869 xvn[n].xv_flag = vp->v_vflag; 2870 2871 switch (vp->v_type) { 2872 case VREG: 2873 case VDIR: 2874 case VLNK: 2875 break; 2876 case VBLK: 2877 case VCHR: 2878 if (vp->v_rdev == NULL) { 2879 vrele(vp); 2880 continue; 2881 } 2882 xvn[n].xv_dev = dev2udev(vp->v_rdev); 2883 break; 2884 case VSOCK: 2885 xvn[n].xv_socket = vp->v_socket; 2886 break; 2887 case VFIFO: 2888 xvn[n].xv_fifo = vp->v_fifoinfo; 2889 break; 2890 case VNON: 2891 case VBAD: 2892 default: 2893 /* shouldn't happen? */ 2894 vrele(vp); 2895 continue; 2896 } 2897 vrele(vp); 2898 ++n; 2899 } 2900 MNT_IUNLOCK(mp); 2901 mtx_lock(&mountlist_mtx); 2902 vfs_unbusy(mp, td); 2903 if (n == len) 2904 break; 2905 } 2906 mtx_unlock(&mountlist_mtx); 2907 2908 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 2909 free(xvn, M_TEMP); 2910 return (error); 2911 } 2912 2913 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2914 0, 0, sysctl_vnode, "S,xvnode", ""); 2915 #endif 2916 2917 /* 2918 * Unmount all filesystems. The list is traversed in reverse order 2919 * of mounting to avoid dependencies. 2920 */ 2921 void 2922 vfs_unmountall(void) 2923 { 2924 struct mount *mp; 2925 struct thread *td; 2926 int error; 2927 2928 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread")); 2929 td = curthread; 2930 /* 2931 * Since this only runs when rebooting, it is not interlocked. 2932 */ 2933 while(!TAILQ_EMPTY(&mountlist)) { 2934 mp = TAILQ_LAST(&mountlist, mntlist); 2935 error = dounmount(mp, MNT_FORCE, td); 2936 if (error) { 2937 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2938 /* 2939 * XXX: Due to the way in which we mount the root 2940 * file system off of devfs, devfs will generate a 2941 * "busy" warning when we try to unmount it before 2942 * the root. Don't print a warning as a result in 2943 * order to avoid false positive errors that may 2944 * cause needless upset. 2945 */ 2946 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) { 2947 printf("unmount of %s failed (", 2948 mp->mnt_stat.f_mntonname); 2949 if (error == EBUSY) 2950 printf("BUSY)\n"); 2951 else 2952 printf("%d)\n", error); 2953 } 2954 } else { 2955 /* The unmount has removed mp from the mountlist */ 2956 } 2957 } 2958 } 2959 2960 /* 2961 * perform msync on all vnodes under a mount point 2962 * the mount point must be locked. 2963 */ 2964 void 2965 vfs_msync(struct mount *mp, int flags) 2966 { 2967 struct vnode *vp, *mvp; 2968 struct vm_object *obj; 2969 2970 MNT_ILOCK(mp); 2971 MNT_VNODE_FOREACH(vp, mp, mvp) { 2972 VI_LOCK(vp); 2973 if ((vp->v_iflag & VI_OBJDIRTY) && 2974 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 2975 MNT_IUNLOCK(mp); 2976 if (!vget(vp, 2977 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 2978 curthread)) { 2979 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 2980 vput(vp); 2981 MNT_ILOCK(mp); 2982 continue; 2983 } 2984 2985 obj = vp->v_object; 2986 if (obj != NULL) { 2987 VM_OBJECT_LOCK(obj); 2988 vm_object_page_clean(obj, 0, 0, 2989 flags == MNT_WAIT ? 2990 OBJPC_SYNC : OBJPC_NOSYNC); 2991 VM_OBJECT_UNLOCK(obj); 2992 } 2993 vput(vp); 2994 } 2995 MNT_ILOCK(mp); 2996 } else 2997 VI_UNLOCK(vp); 2998 } 2999 MNT_IUNLOCK(mp); 3000 } 3001 3002 /* 3003 * Mark a vnode as free, putting it up for recycling. 3004 */ 3005 static void 3006 vfree(struct vnode *vp) 3007 { 3008 3009 CTR1(KTR_VFS, "vfree vp %p", vp); 3010 ASSERT_VI_LOCKED(vp, "vfree"); 3011 mtx_lock(&vnode_free_list_mtx); 3012 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed.")); 3013 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free")); 3014 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't")); 3015 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp, 3016 ("vfree: Freeing doomed vnode")); 3017 if (vp->v_iflag & VI_AGE) { 3018 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3019 } else { 3020 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3021 } 3022 freevnodes++; 3023 vp->v_iflag &= ~VI_AGE; 3024 vp->v_iflag |= VI_FREE; 3025 mtx_unlock(&vnode_free_list_mtx); 3026 } 3027 3028 /* 3029 * Opposite of vfree() - mark a vnode as in use. 3030 */ 3031 static void 3032 vbusy(struct vnode *vp) 3033 { 3034 CTR1(KTR_VFS, "vbusy vp %p", vp); 3035 ASSERT_VI_LOCKED(vp, "vbusy"); 3036 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free")); 3037 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed.")); 3038 3039 mtx_lock(&vnode_free_list_mtx); 3040 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3041 freevnodes--; 3042 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3043 mtx_unlock(&vnode_free_list_mtx); 3044 } 3045 3046 /* 3047 * Initalize per-vnode helper structure to hold poll-related state. 3048 */ 3049 void 3050 v_addpollinfo(struct vnode *vp) 3051 { 3052 struct vpollinfo *vi; 3053 3054 vi = uma_zalloc(vnodepoll_zone, M_WAITOK); 3055 if (vp->v_pollinfo != NULL) { 3056 uma_zfree(vnodepoll_zone, vi); 3057 return; 3058 } 3059 vp->v_pollinfo = vi; 3060 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3061 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock, 3062 vfs_knlunlock, vfs_knllocked); 3063 } 3064 3065 /* 3066 * Record a process's interest in events which might happen to 3067 * a vnode. Because poll uses the historic select-style interface 3068 * internally, this routine serves as both the ``check for any 3069 * pending events'' and the ``record my interest in future events'' 3070 * functions. (These are done together, while the lock is held, 3071 * to avoid race conditions.) 3072 */ 3073 int 3074 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 3075 { 3076 3077 if (vp->v_pollinfo == NULL) 3078 v_addpollinfo(vp); 3079 mtx_lock(&vp->v_pollinfo->vpi_lock); 3080 if (vp->v_pollinfo->vpi_revents & events) { 3081 /* 3082 * This leaves events we are not interested 3083 * in available for the other process which 3084 * which presumably had requested them 3085 * (otherwise they would never have been 3086 * recorded). 3087 */ 3088 events &= vp->v_pollinfo->vpi_revents; 3089 vp->v_pollinfo->vpi_revents &= ~events; 3090 3091 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3092 return events; 3093 } 3094 vp->v_pollinfo->vpi_events |= events; 3095 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3096 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3097 return 0; 3098 } 3099 3100 /* 3101 * Routine to create and manage a filesystem syncer vnode. 3102 */ 3103 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3104 static int sync_fsync(struct vop_fsync_args *); 3105 static int sync_inactive(struct vop_inactive_args *); 3106 static int sync_reclaim(struct vop_reclaim_args *); 3107 3108 static struct vop_vector sync_vnodeops = { 3109 .vop_bypass = VOP_EOPNOTSUPP, 3110 .vop_close = sync_close, /* close */ 3111 .vop_fsync = sync_fsync, /* fsync */ 3112 .vop_inactive = sync_inactive, /* inactive */ 3113 .vop_reclaim = sync_reclaim, /* reclaim */ 3114 .vop_lock1 = vop_stdlock, /* lock */ 3115 .vop_unlock = vop_stdunlock, /* unlock */ 3116 .vop_islocked = vop_stdislocked, /* islocked */ 3117 }; 3118 3119 /* 3120 * Create a new filesystem syncer vnode for the specified mount point. 3121 */ 3122 int 3123 vfs_allocate_syncvnode(struct mount *mp) 3124 { 3125 struct vnode *vp; 3126 static long start, incr, next; 3127 int error; 3128 3129 /* Allocate a new vnode */ 3130 if ((error = getnewvnode("syncer", mp, &sync_vnodeops, &vp)) != 0) { 3131 mp->mnt_syncer = NULL; 3132 return (error); 3133 } 3134 vp->v_type = VNON; 3135 error = insmntque(vp, mp); 3136 if (error != 0) 3137 panic("vfs_allocate_syncvnode: insmntque failed"); 3138 /* 3139 * Place the vnode onto the syncer worklist. We attempt to 3140 * scatter them about on the list so that they will go off 3141 * at evenly distributed times even if all the filesystems 3142 * are mounted at once. 3143 */ 3144 next += incr; 3145 if (next == 0 || next > syncer_maxdelay) { 3146 start /= 2; 3147 incr /= 2; 3148 if (start == 0) { 3149 start = syncer_maxdelay / 2; 3150 incr = syncer_maxdelay; 3151 } 3152 next = start; 3153 } 3154 VI_LOCK(vp); 3155 vn_syncer_add_to_worklist(&vp->v_bufobj, 3156 syncdelay > 0 ? next % syncdelay : 0); 3157 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 3158 mtx_lock(&sync_mtx); 3159 sync_vnode_count++; 3160 mtx_unlock(&sync_mtx); 3161 VI_UNLOCK(vp); 3162 mp->mnt_syncer = vp; 3163 return (0); 3164 } 3165 3166 /* 3167 * Do a lazy sync of the filesystem. 3168 */ 3169 static int 3170 sync_fsync(struct vop_fsync_args *ap) 3171 { 3172 struct vnode *syncvp = ap->a_vp; 3173 struct mount *mp = syncvp->v_mount; 3174 struct thread *td = ap->a_td; 3175 int error; 3176 struct bufobj *bo; 3177 3178 /* 3179 * We only need to do something if this is a lazy evaluation. 3180 */ 3181 if (ap->a_waitfor != MNT_LAZY) 3182 return (0); 3183 3184 /* 3185 * Move ourselves to the back of the sync list. 3186 */ 3187 bo = &syncvp->v_bufobj; 3188 BO_LOCK(bo); 3189 vn_syncer_add_to_worklist(bo, syncdelay); 3190 BO_UNLOCK(bo); 3191 3192 /* 3193 * Walk the list of vnodes pushing all that are dirty and 3194 * not already on the sync list. 3195 */ 3196 mtx_lock(&mountlist_mtx); 3197 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3198 mtx_unlock(&mountlist_mtx); 3199 return (0); 3200 } 3201 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3202 vfs_unbusy(mp, td); 3203 return (0); 3204 } 3205 MNT_ILOCK(mp); 3206 mp->mnt_noasync++; 3207 mp->mnt_kern_flag &= ~MNTK_ASYNC; 3208 MNT_IUNLOCK(mp); 3209 vfs_msync(mp, MNT_NOWAIT); 3210 error = VFS_SYNC(mp, MNT_LAZY, td); 3211 MNT_ILOCK(mp); 3212 mp->mnt_noasync--; 3213 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 3214 mp->mnt_kern_flag |= MNTK_ASYNC; 3215 MNT_IUNLOCK(mp); 3216 vn_finished_write(mp); 3217 vfs_unbusy(mp, td); 3218 return (error); 3219 } 3220 3221 /* 3222 * The syncer vnode is no referenced. 3223 */ 3224 static int 3225 sync_inactive(struct vop_inactive_args *ap) 3226 { 3227 3228 vgone(ap->a_vp); 3229 return (0); 3230 } 3231 3232 /* 3233 * The syncer vnode is no longer needed and is being decommissioned. 3234 * 3235 * Modifications to the worklist must be protected by sync_mtx. 3236 */ 3237 static int 3238 sync_reclaim(struct vop_reclaim_args *ap) 3239 { 3240 struct vnode *vp = ap->a_vp; 3241 struct bufobj *bo; 3242 3243 VI_LOCK(vp); 3244 bo = &vp->v_bufobj; 3245 vp->v_mount->mnt_syncer = NULL; 3246 if (bo->bo_flag & BO_ONWORKLST) { 3247 mtx_lock(&sync_mtx); 3248 LIST_REMOVE(bo, bo_synclist); 3249 syncer_worklist_len--; 3250 sync_vnode_count--; 3251 mtx_unlock(&sync_mtx); 3252 bo->bo_flag &= ~BO_ONWORKLST; 3253 } 3254 VI_UNLOCK(vp); 3255 3256 return (0); 3257 } 3258 3259 /* 3260 * Check if vnode represents a disk device 3261 */ 3262 int 3263 vn_isdisk(struct vnode *vp, int *errp) 3264 { 3265 int error; 3266 3267 error = 0; 3268 dev_lock(); 3269 if (vp->v_type != VCHR) 3270 error = ENOTBLK; 3271 else if (vp->v_rdev == NULL) 3272 error = ENXIO; 3273 else if (vp->v_rdev->si_devsw == NULL) 3274 error = ENXIO; 3275 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 3276 error = ENOTBLK; 3277 dev_unlock(); 3278 if (errp != NULL) 3279 *errp = error; 3280 return (error == 0); 3281 } 3282 3283 /* 3284 * Common filesystem object access control check routine. Accepts a 3285 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3286 * and optional call-by-reference privused argument allowing vaccess() 3287 * to indicate to the caller whether privilege was used to satisfy the 3288 * request (obsoleted). Returns 0 on success, or an errno on failure. 3289 * 3290 * The ifdef'd CAPABILITIES version is here for reference, but is not 3291 * actually used. 3292 */ 3293 int 3294 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 3295 mode_t acc_mode, struct ucred *cred, int *privused) 3296 { 3297 mode_t dac_granted; 3298 mode_t priv_granted; 3299 3300 /* 3301 * Look for a normal, non-privileged way to access the file/directory 3302 * as requested. If it exists, go with that. 3303 */ 3304 3305 if (privused != NULL) 3306 *privused = 0; 3307 3308 dac_granted = 0; 3309 3310 /* Check the owner. */ 3311 if (cred->cr_uid == file_uid) { 3312 dac_granted |= VADMIN; 3313 if (file_mode & S_IXUSR) 3314 dac_granted |= VEXEC; 3315 if (file_mode & S_IRUSR) 3316 dac_granted |= VREAD; 3317 if (file_mode & S_IWUSR) 3318 dac_granted |= (VWRITE | VAPPEND); 3319 3320 if ((acc_mode & dac_granted) == acc_mode) 3321 return (0); 3322 3323 goto privcheck; 3324 } 3325 3326 /* Otherwise, check the groups (first match) */ 3327 if (groupmember(file_gid, cred)) { 3328 if (file_mode & S_IXGRP) 3329 dac_granted |= VEXEC; 3330 if (file_mode & S_IRGRP) 3331 dac_granted |= VREAD; 3332 if (file_mode & S_IWGRP) 3333 dac_granted |= (VWRITE | VAPPEND); 3334 3335 if ((acc_mode & dac_granted) == acc_mode) 3336 return (0); 3337 3338 goto privcheck; 3339 } 3340 3341 /* Otherwise, check everyone else. */ 3342 if (file_mode & S_IXOTH) 3343 dac_granted |= VEXEC; 3344 if (file_mode & S_IROTH) 3345 dac_granted |= VREAD; 3346 if (file_mode & S_IWOTH) 3347 dac_granted |= (VWRITE | VAPPEND); 3348 if ((acc_mode & dac_granted) == acc_mode) 3349 return (0); 3350 3351 privcheck: 3352 /* 3353 * Build a privilege mask to determine if the set of privileges 3354 * satisfies the requirements when combined with the granted mask 3355 * from above. For each privilege, if the privilege is required, 3356 * bitwise or the request type onto the priv_granted mask. 3357 */ 3358 priv_granted = 0; 3359 3360 if (type == VDIR) { 3361 /* 3362 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 3363 * requests, instead of PRIV_VFS_EXEC. 3364 */ 3365 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3366 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 3367 priv_granted |= VEXEC; 3368 } else { 3369 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3370 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 3371 priv_granted |= VEXEC; 3372 } 3373 3374 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3375 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 3376 priv_granted |= VREAD; 3377 3378 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3379 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 3380 priv_granted |= (VWRITE | VAPPEND); 3381 3382 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3383 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 3384 priv_granted |= VADMIN; 3385 3386 if ((acc_mode & (priv_granted | dac_granted)) == acc_mode) { 3387 /* XXX audit: privilege used */ 3388 if (privused != NULL) 3389 *privused = 1; 3390 return (0); 3391 } 3392 3393 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3394 } 3395 3396 /* 3397 * Credential check based on process requesting service, and per-attribute 3398 * permissions. 3399 */ 3400 int 3401 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 3402 struct thread *td, int access) 3403 { 3404 3405 /* 3406 * Kernel-invoked always succeeds. 3407 */ 3408 if (cred == NOCRED) 3409 return (0); 3410 3411 /* 3412 * Do not allow privileged processes in jail to directly manipulate 3413 * system attributes. 3414 */ 3415 switch (attrnamespace) { 3416 case EXTATTR_NAMESPACE_SYSTEM: 3417 /* Potentially should be: return (EPERM); */ 3418 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 3419 case EXTATTR_NAMESPACE_USER: 3420 return (VOP_ACCESS(vp, access, cred, td)); 3421 default: 3422 return (EPERM); 3423 } 3424 } 3425 3426 #ifdef DEBUG_VFS_LOCKS 3427 /* 3428 * This only exists to supress warnings from unlocked specfs accesses. It is 3429 * no longer ok to have an unlocked VFS. 3430 */ 3431 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 3432 3433 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3434 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, ""); 3435 3436 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3437 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, ""); 3438 3439 int vfs_badlock_print = 1; /* Print lock violations. */ 3440 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, ""); 3441 3442 #ifdef KDB 3443 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 3444 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, ""); 3445 #endif 3446 3447 static void 3448 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3449 { 3450 3451 #ifdef KDB 3452 if (vfs_badlock_backtrace) 3453 kdb_backtrace(); 3454 #endif 3455 if (vfs_badlock_print) 3456 printf("%s: %p %s\n", str, (void *)vp, msg); 3457 if (vfs_badlock_ddb) 3458 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 3459 } 3460 3461 void 3462 assert_vi_locked(struct vnode *vp, const char *str) 3463 { 3464 3465 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3466 vfs_badlock("interlock is not locked but should be", str, vp); 3467 } 3468 3469 void 3470 assert_vi_unlocked(struct vnode *vp, const char *str) 3471 { 3472 3473 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3474 vfs_badlock("interlock is locked but should not be", str, vp); 3475 } 3476 3477 void 3478 assert_vop_locked(struct vnode *vp, const char *str) 3479 { 3480 3481 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0) 3482 vfs_badlock("is not locked but should be", str, vp); 3483 } 3484 3485 void 3486 assert_vop_unlocked(struct vnode *vp, const char *str) 3487 { 3488 3489 if (vp && !IGNORE_LOCK(vp) && 3490 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 3491 vfs_badlock("is locked but should not be", str, vp); 3492 } 3493 3494 void 3495 assert_vop_elocked(struct vnode *vp, const char *str) 3496 { 3497 3498 if (vp && !IGNORE_LOCK(vp) && 3499 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 3500 vfs_badlock("is not exclusive locked but should be", str, vp); 3501 } 3502 3503 #if 0 3504 void 3505 assert_vop_elocked_other(struct vnode *vp, const char *str) 3506 { 3507 3508 if (vp && !IGNORE_LOCK(vp) && 3509 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 3510 vfs_badlock("is not exclusive locked by another thread", 3511 str, vp); 3512 } 3513 3514 void 3515 assert_vop_slocked(struct vnode *vp, const char *str) 3516 { 3517 3518 if (vp && !IGNORE_LOCK(vp) && 3519 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 3520 vfs_badlock("is not locked shared but should be", str, vp); 3521 } 3522 #endif /* 0 */ 3523 #endif /* DEBUG_VFS_LOCKS */ 3524 3525 void 3526 vop_rename_pre(void *ap) 3527 { 3528 struct vop_rename_args *a = ap; 3529 3530 #ifdef DEBUG_VFS_LOCKS 3531 if (a->a_tvp) 3532 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3533 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3534 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3535 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3536 3537 /* Check the source (from). */ 3538 if (a->a_tdvp != a->a_fdvp && a->a_tvp != a->a_fdvp) 3539 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3540 if (a->a_tvp != a->a_fvp) 3541 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 3542 3543 /* Check the target. */ 3544 if (a->a_tvp) 3545 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3546 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3547 #endif 3548 if (a->a_tdvp != a->a_fdvp) 3549 vhold(a->a_fdvp); 3550 if (a->a_tvp != a->a_fvp) 3551 vhold(a->a_fvp); 3552 vhold(a->a_tdvp); 3553 if (a->a_tvp) 3554 vhold(a->a_tvp); 3555 } 3556 3557 void 3558 vop_strategy_pre(void *ap) 3559 { 3560 #ifdef DEBUG_VFS_LOCKS 3561 struct vop_strategy_args *a; 3562 struct buf *bp; 3563 3564 a = ap; 3565 bp = a->a_bp; 3566 3567 /* 3568 * Cluster ops lock their component buffers but not the IO container. 3569 */ 3570 if ((bp->b_flags & B_CLUSTER) != 0) 3571 return; 3572 3573 if (BUF_REFCNT(bp) < 1) { 3574 if (vfs_badlock_print) 3575 printf( 3576 "VOP_STRATEGY: bp is not locked but should be\n"); 3577 if (vfs_badlock_ddb) 3578 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 3579 } 3580 #endif 3581 } 3582 3583 void 3584 vop_lookup_pre(void *ap) 3585 { 3586 #ifdef DEBUG_VFS_LOCKS 3587 struct vop_lookup_args *a; 3588 struct vnode *dvp; 3589 3590 a = ap; 3591 dvp = a->a_dvp; 3592 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3593 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3594 #endif 3595 } 3596 3597 void 3598 vop_lookup_post(void *ap, int rc) 3599 { 3600 #ifdef DEBUG_VFS_LOCKS 3601 struct vop_lookup_args *a; 3602 struct vnode *dvp; 3603 struct vnode *vp; 3604 3605 a = ap; 3606 dvp = a->a_dvp; 3607 vp = *(a->a_vpp); 3608 3609 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3610 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3611 3612 if (!rc) 3613 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)"); 3614 #endif 3615 } 3616 3617 void 3618 vop_lock_pre(void *ap) 3619 { 3620 #ifdef DEBUG_VFS_LOCKS 3621 struct vop_lock1_args *a = ap; 3622 3623 if ((a->a_flags & LK_INTERLOCK) == 0) 3624 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3625 else 3626 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3627 #endif 3628 } 3629 3630 void 3631 vop_lock_post(void *ap, int rc) 3632 { 3633 #ifdef DEBUG_VFS_LOCKS 3634 struct vop_lock1_args *a = ap; 3635 3636 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3637 if (rc == 0) 3638 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3639 #endif 3640 } 3641 3642 void 3643 vop_unlock_pre(void *ap) 3644 { 3645 #ifdef DEBUG_VFS_LOCKS 3646 struct vop_unlock_args *a = ap; 3647 3648 if (a->a_flags & LK_INTERLOCK) 3649 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 3650 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 3651 #endif 3652 } 3653 3654 void 3655 vop_unlock_post(void *ap, int rc) 3656 { 3657 #ifdef DEBUG_VFS_LOCKS 3658 struct vop_unlock_args *a = ap; 3659 3660 if (a->a_flags & LK_INTERLOCK) 3661 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 3662 #endif 3663 } 3664 3665 void 3666 vop_create_post(void *ap, int rc) 3667 { 3668 struct vop_create_args *a = ap; 3669 3670 if (!rc) 3671 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3672 } 3673 3674 void 3675 vop_link_post(void *ap, int rc) 3676 { 3677 struct vop_link_args *a = ap; 3678 3679 if (!rc) { 3680 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 3681 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 3682 } 3683 } 3684 3685 void 3686 vop_mkdir_post(void *ap, int rc) 3687 { 3688 struct vop_mkdir_args *a = ap; 3689 3690 if (!rc) 3691 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 3692 } 3693 3694 void 3695 vop_mknod_post(void *ap, int rc) 3696 { 3697 struct vop_mknod_args *a = ap; 3698 3699 if (!rc) 3700 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3701 } 3702 3703 void 3704 vop_remove_post(void *ap, int rc) 3705 { 3706 struct vop_remove_args *a = ap; 3707 3708 if (!rc) { 3709 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3710 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 3711 } 3712 } 3713 3714 void 3715 vop_rename_post(void *ap, int rc) 3716 { 3717 struct vop_rename_args *a = ap; 3718 3719 if (!rc) { 3720 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE); 3721 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE); 3722 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 3723 if (a->a_tvp) 3724 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 3725 } 3726 if (a->a_tdvp != a->a_fdvp) 3727 vdrop(a->a_fdvp); 3728 if (a->a_tvp != a->a_fvp) 3729 vdrop(a->a_fvp); 3730 vdrop(a->a_tdvp); 3731 if (a->a_tvp) 3732 vdrop(a->a_tvp); 3733 } 3734 3735 void 3736 vop_rmdir_post(void *ap, int rc) 3737 { 3738 struct vop_rmdir_args *a = ap; 3739 3740 if (!rc) { 3741 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 3742 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 3743 } 3744 } 3745 3746 void 3747 vop_setattr_post(void *ap, int rc) 3748 { 3749 struct vop_setattr_args *a = ap; 3750 3751 if (!rc) 3752 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 3753 } 3754 3755 void 3756 vop_symlink_post(void *ap, int rc) 3757 { 3758 struct vop_symlink_args *a = ap; 3759 3760 if (!rc) 3761 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3762 } 3763 3764 static struct knlist fs_knlist; 3765 3766 static void 3767 vfs_event_init(void *arg) 3768 { 3769 knlist_init(&fs_knlist, NULL, NULL, NULL, NULL); 3770 } 3771 /* XXX - correct order? */ 3772 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 3773 3774 void 3775 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused) 3776 { 3777 3778 KNOTE_UNLOCKED(&fs_knlist, event); 3779 } 3780 3781 static int filt_fsattach(struct knote *kn); 3782 static void filt_fsdetach(struct knote *kn); 3783 static int filt_fsevent(struct knote *kn, long hint); 3784 3785 struct filterops fs_filtops = 3786 { 0, filt_fsattach, filt_fsdetach, filt_fsevent }; 3787 3788 static int 3789 filt_fsattach(struct knote *kn) 3790 { 3791 3792 kn->kn_flags |= EV_CLEAR; 3793 knlist_add(&fs_knlist, kn, 0); 3794 return (0); 3795 } 3796 3797 static void 3798 filt_fsdetach(struct knote *kn) 3799 { 3800 3801 knlist_remove(&fs_knlist, kn, 0); 3802 } 3803 3804 static int 3805 filt_fsevent(struct knote *kn, long hint) 3806 { 3807 3808 kn->kn_fflags |= hint; 3809 return (kn->kn_fflags != 0); 3810 } 3811 3812 static int 3813 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 3814 { 3815 struct vfsidctl vc; 3816 int error; 3817 struct mount *mp; 3818 3819 error = SYSCTL_IN(req, &vc, sizeof(vc)); 3820 if (error) 3821 return (error); 3822 if (vc.vc_vers != VFS_CTL_VERS1) 3823 return (EINVAL); 3824 mp = vfs_getvfs(&vc.vc_fsid); 3825 if (mp == NULL) 3826 return (ENOENT); 3827 /* ensure that a specific sysctl goes to the right filesystem. */ 3828 if (strcmp(vc.vc_fstypename, "*") != 0 && 3829 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 3830 vfs_rel(mp); 3831 return (EINVAL); 3832 } 3833 VCTLTOREQ(&vc, req); 3834 error = VFS_SYSCTL(mp, vc.vc_op, req); 3835 vfs_rel(mp); 3836 return (error); 3837 } 3838 3839 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, NULL, 0, sysctl_vfs_ctl, "", 3840 "Sysctl by fsid"); 3841 3842 /* 3843 * Function to initialize a va_filerev field sensibly. 3844 * XXX: Wouldn't a random number make a lot more sense ?? 3845 */ 3846 u_quad_t 3847 init_va_filerev(void) 3848 { 3849 struct bintime bt; 3850 3851 getbinuptime(&bt); 3852 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 3853 } 3854 3855 static int filt_vfsread(struct knote *kn, long hint); 3856 static int filt_vfswrite(struct knote *kn, long hint); 3857 static int filt_vfsvnode(struct knote *kn, long hint); 3858 static void filt_vfsdetach(struct knote *kn); 3859 static struct filterops vfsread_filtops = 3860 { 1, NULL, filt_vfsdetach, filt_vfsread }; 3861 static struct filterops vfswrite_filtops = 3862 { 1, NULL, filt_vfsdetach, filt_vfswrite }; 3863 static struct filterops vfsvnode_filtops = 3864 { 1, NULL, filt_vfsdetach, filt_vfsvnode }; 3865 3866 static void 3867 vfs_knllock(void *arg) 3868 { 3869 struct vnode *vp = arg; 3870 3871 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3872 } 3873 3874 static void 3875 vfs_knlunlock(void *arg) 3876 { 3877 struct vnode *vp = arg; 3878 3879 VOP_UNLOCK(vp, 0); 3880 } 3881 3882 static int 3883 vfs_knllocked(void *arg) 3884 { 3885 struct vnode *vp = arg; 3886 3887 return (VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE); 3888 } 3889 3890 int 3891 vfs_kqfilter(struct vop_kqfilter_args *ap) 3892 { 3893 struct vnode *vp = ap->a_vp; 3894 struct knote *kn = ap->a_kn; 3895 struct knlist *knl; 3896 3897 switch (kn->kn_filter) { 3898 case EVFILT_READ: 3899 kn->kn_fop = &vfsread_filtops; 3900 break; 3901 case EVFILT_WRITE: 3902 kn->kn_fop = &vfswrite_filtops; 3903 break; 3904 case EVFILT_VNODE: 3905 kn->kn_fop = &vfsvnode_filtops; 3906 break; 3907 default: 3908 return (EINVAL); 3909 } 3910 3911 kn->kn_hook = (caddr_t)vp; 3912 3913 if (vp->v_pollinfo == NULL) 3914 v_addpollinfo(vp); 3915 if (vp->v_pollinfo == NULL) 3916 return (ENOMEM); 3917 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 3918 knlist_add(knl, kn, 0); 3919 3920 return (0); 3921 } 3922 3923 /* 3924 * Detach knote from vnode 3925 */ 3926 static void 3927 filt_vfsdetach(struct knote *kn) 3928 { 3929 struct vnode *vp = (struct vnode *)kn->kn_hook; 3930 3931 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 3932 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 3933 } 3934 3935 /*ARGSUSED*/ 3936 static int 3937 filt_vfsread(struct knote *kn, long hint) 3938 { 3939 struct vnode *vp = (struct vnode *)kn->kn_hook; 3940 struct vattr va; 3941 3942 /* 3943 * filesystem is gone, so set the EOF flag and schedule 3944 * the knote for deletion. 3945 */ 3946 if (hint == NOTE_REVOKE) { 3947 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 3948 return (1); 3949 } 3950 3951 if (VOP_GETATTR(vp, &va, curthread->td_ucred, curthread)) 3952 return (0); 3953 3954 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 3955 return (kn->kn_data != 0); 3956 } 3957 3958 /*ARGSUSED*/ 3959 static int 3960 filt_vfswrite(struct knote *kn, long hint) 3961 { 3962 /* 3963 * filesystem is gone, so set the EOF flag and schedule 3964 * the knote for deletion. 3965 */ 3966 if (hint == NOTE_REVOKE) 3967 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 3968 3969 kn->kn_data = 0; 3970 return (1); 3971 } 3972 3973 static int 3974 filt_vfsvnode(struct knote *kn, long hint) 3975 { 3976 if (kn->kn_sfflags & hint) 3977 kn->kn_fflags |= hint; 3978 if (hint == NOTE_REVOKE) { 3979 kn->kn_flags |= EV_EOF; 3980 return (1); 3981 } 3982 return (kn->kn_fflags != 0); 3983 } 3984 3985 int 3986 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 3987 { 3988 int error; 3989 3990 if (dp->d_reclen > ap->a_uio->uio_resid) 3991 return (ENAMETOOLONG); 3992 error = uiomove(dp, dp->d_reclen, ap->a_uio); 3993 if (error) { 3994 if (ap->a_ncookies != NULL) { 3995 if (ap->a_cookies != NULL) 3996 free(ap->a_cookies, M_TEMP); 3997 ap->a_cookies = NULL; 3998 *ap->a_ncookies = 0; 3999 } 4000 return (error); 4001 } 4002 if (ap->a_ncookies == NULL) 4003 return (0); 4004 4005 KASSERT(ap->a_cookies, 4006 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 4007 4008 *ap->a_cookies = realloc(*ap->a_cookies, 4009 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 4010 (*ap->a_cookies)[*ap->a_ncookies] = off; 4011 return (0); 4012 } 4013 4014 /* 4015 * Mark for update the access time of the file if the filesystem 4016 * supports VA_MARK_ATIME. This functionality is used by execve 4017 * and mmap, so we want to avoid the synchronous I/O implied by 4018 * directly setting va_atime for the sake of efficiency. 4019 */ 4020 void 4021 vfs_mark_atime(struct vnode *vp, struct thread *td) 4022 { 4023 struct vattr atimeattr; 4024 4025 if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) { 4026 VATTR_NULL(&atimeattr); 4027 atimeattr.va_vaflags |= VA_MARK_ATIME; 4028 (void)VOP_SETATTR(vp, &atimeattr, td->td_ucred, td); 4029 } 4030 } 4031