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))) 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); 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 { 998 999 vp->v_data = NULL; 1000 vp->v_op = &dead_vnodeops; 1001 /* XXX non mp-safe fs may still call insmntque with vnode 1002 unlocked */ 1003 if (!VOP_ISLOCKED(vp)) 1004 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1005 vgone(vp); 1006 vput(vp); 1007 } 1008 1009 /* 1010 * Insert into list of vnodes for the new mount point, if available. 1011 */ 1012 int 1013 insmntque1(struct vnode *vp, struct mount *mp, 1014 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1015 { 1016 1017 KASSERT(vp->v_mount == NULL, 1018 ("insmntque: vnode already on per mount vnode list")); 1019 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1020 MNT_ILOCK(mp); 1021 if ((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1022 mp->mnt_nvnodelistsize == 0) { 1023 MNT_IUNLOCK(mp); 1024 if (dtr != NULL) 1025 dtr(vp, dtr_arg); 1026 return (EBUSY); 1027 } 1028 vp->v_mount = mp; 1029 MNT_REF(mp); 1030 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1031 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1032 ("neg mount point vnode list size")); 1033 mp->mnt_nvnodelistsize++; 1034 MNT_IUNLOCK(mp); 1035 return (0); 1036 } 1037 1038 int 1039 insmntque(struct vnode *vp, struct mount *mp) 1040 { 1041 1042 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1043 } 1044 1045 /* 1046 * Flush out and invalidate all buffers associated with a bufobj 1047 * Called with the underlying object locked. 1048 */ 1049 int 1050 bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag, 1051 int slptimeo) 1052 { 1053 int error; 1054 1055 BO_LOCK(bo); 1056 if (flags & V_SAVE) { 1057 error = bufobj_wwait(bo, slpflag, slptimeo); 1058 if (error) { 1059 BO_UNLOCK(bo); 1060 return (error); 1061 } 1062 if (bo->bo_dirty.bv_cnt > 0) { 1063 BO_UNLOCK(bo); 1064 if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0) 1065 return (error); 1066 /* 1067 * XXX We could save a lock/unlock if this was only 1068 * enabled under INVARIANTS 1069 */ 1070 BO_LOCK(bo); 1071 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1072 panic("vinvalbuf: dirty bufs"); 1073 } 1074 } 1075 /* 1076 * If you alter this loop please notice that interlock is dropped and 1077 * reacquired in flushbuflist. Special care is needed to ensure that 1078 * no race conditions occur from this. 1079 */ 1080 do { 1081 error = flushbuflist(&bo->bo_clean, 1082 flags, bo, slpflag, slptimeo); 1083 if (error == 0) 1084 error = flushbuflist(&bo->bo_dirty, 1085 flags, bo, slpflag, slptimeo); 1086 if (error != 0 && error != EAGAIN) { 1087 BO_UNLOCK(bo); 1088 return (error); 1089 } 1090 } while (error != 0); 1091 1092 /* 1093 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1094 * have write I/O in-progress but if there is a VM object then the 1095 * VM object can also have read-I/O in-progress. 1096 */ 1097 do { 1098 bufobj_wwait(bo, 0, 0); 1099 BO_UNLOCK(bo); 1100 if (bo->bo_object != NULL) { 1101 VM_OBJECT_LOCK(bo->bo_object); 1102 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1103 VM_OBJECT_UNLOCK(bo->bo_object); 1104 } 1105 BO_LOCK(bo); 1106 } while (bo->bo_numoutput > 0); 1107 BO_UNLOCK(bo); 1108 1109 /* 1110 * Destroy the copy in the VM cache, too. 1111 */ 1112 if (bo->bo_object != NULL) { 1113 VM_OBJECT_LOCK(bo->bo_object); 1114 vm_object_page_remove(bo->bo_object, 0, 0, 1115 (flags & V_SAVE) ? TRUE : FALSE); 1116 VM_OBJECT_UNLOCK(bo->bo_object); 1117 } 1118 1119 #ifdef INVARIANTS 1120 BO_LOCK(bo); 1121 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1122 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0)) 1123 panic("vinvalbuf: flush failed"); 1124 BO_UNLOCK(bo); 1125 #endif 1126 return (0); 1127 } 1128 1129 /* 1130 * Flush out and invalidate all buffers associated with a vnode. 1131 * Called with the underlying object locked. 1132 */ 1133 int 1134 vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag, 1135 int slptimeo) 1136 { 1137 1138 CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags); 1139 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1140 return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo)); 1141 } 1142 1143 /* 1144 * Flush out buffers on the specified list. 1145 * 1146 */ 1147 static int 1148 flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1149 int slptimeo) 1150 { 1151 struct buf *bp, *nbp; 1152 int retval, error; 1153 daddr_t lblkno; 1154 b_xflags_t xflags; 1155 1156 ASSERT_BO_LOCKED(bo); 1157 1158 retval = 0; 1159 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1160 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1161 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1162 continue; 1163 } 1164 lblkno = 0; 1165 xflags = 0; 1166 if (nbp != NULL) { 1167 lblkno = nbp->b_lblkno; 1168 xflags = nbp->b_xflags & 1169 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN); 1170 } 1171 retval = EAGAIN; 1172 error = BUF_TIMELOCK(bp, 1173 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo), 1174 "flushbuf", slpflag, slptimeo); 1175 if (error) { 1176 BO_LOCK(bo); 1177 return (error != ENOLCK ? error : EAGAIN); 1178 } 1179 KASSERT(bp->b_bufobj == bo, 1180 ("bp %p wrong b_bufobj %p should be %p", 1181 bp, bp->b_bufobj, bo)); 1182 if (bp->b_bufobj != bo) { /* XXX: necessary ? */ 1183 BUF_UNLOCK(bp); 1184 BO_LOCK(bo); 1185 return (EAGAIN); 1186 } 1187 /* 1188 * XXX Since there are no node locks for NFS, I 1189 * believe there is a slight chance that a delayed 1190 * write will occur while sleeping just above, so 1191 * check for it. 1192 */ 1193 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1194 (flags & V_SAVE)) { 1195 bremfree(bp); 1196 bp->b_flags |= B_ASYNC; 1197 bwrite(bp); 1198 BO_LOCK(bo); 1199 return (EAGAIN); /* XXX: why not loop ? */ 1200 } 1201 bremfree(bp); 1202 bp->b_flags |= (B_INVAL | B_RELBUF); 1203 bp->b_flags &= ~B_ASYNC; 1204 brelse(bp); 1205 BO_LOCK(bo); 1206 if (nbp != NULL && 1207 (nbp->b_bufobj != bo || 1208 nbp->b_lblkno != lblkno || 1209 (nbp->b_xflags & 1210 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags)) 1211 break; /* nbp invalid */ 1212 } 1213 return (retval); 1214 } 1215 1216 /* 1217 * Truncate a file's buffer and pages to a specified length. This 1218 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1219 * sync activity. 1220 */ 1221 int 1222 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td, 1223 off_t length, int blksize) 1224 { 1225 struct buf *bp, *nbp; 1226 int anyfreed; 1227 int trunclbn; 1228 struct bufobj *bo; 1229 1230 CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length); 1231 /* 1232 * Round up to the *next* lbn. 1233 */ 1234 trunclbn = (length + blksize - 1) / blksize; 1235 1236 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1237 restart: 1238 VI_LOCK(vp); 1239 bo = &vp->v_bufobj; 1240 anyfreed = 1; 1241 for (;anyfreed;) { 1242 anyfreed = 0; 1243 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1244 if (bp->b_lblkno < trunclbn) 1245 continue; 1246 if (BUF_LOCK(bp, 1247 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1248 VI_MTX(vp)) == ENOLCK) 1249 goto restart; 1250 1251 bremfree(bp); 1252 bp->b_flags |= (B_INVAL | B_RELBUF); 1253 bp->b_flags &= ~B_ASYNC; 1254 brelse(bp); 1255 anyfreed = 1; 1256 1257 if (nbp != NULL && 1258 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1259 (nbp->b_vp != vp) || 1260 (nbp->b_flags & B_DELWRI))) { 1261 goto restart; 1262 } 1263 VI_LOCK(vp); 1264 } 1265 1266 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1267 if (bp->b_lblkno < trunclbn) 1268 continue; 1269 if (BUF_LOCK(bp, 1270 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1271 VI_MTX(vp)) == ENOLCK) 1272 goto restart; 1273 bremfree(bp); 1274 bp->b_flags |= (B_INVAL | B_RELBUF); 1275 bp->b_flags &= ~B_ASYNC; 1276 brelse(bp); 1277 anyfreed = 1; 1278 if (nbp != NULL && 1279 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1280 (nbp->b_vp != vp) || 1281 (nbp->b_flags & B_DELWRI) == 0)) { 1282 goto restart; 1283 } 1284 VI_LOCK(vp); 1285 } 1286 } 1287 1288 if (length > 0) { 1289 restartsync: 1290 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1291 if (bp->b_lblkno > 0) 1292 continue; 1293 /* 1294 * Since we hold the vnode lock this should only 1295 * fail if we're racing with the buf daemon. 1296 */ 1297 if (BUF_LOCK(bp, 1298 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1299 VI_MTX(vp)) == ENOLCK) { 1300 goto restart; 1301 } 1302 VNASSERT((bp->b_flags & B_DELWRI), vp, 1303 ("buf(%p) on dirty queue without DELWRI", bp)); 1304 1305 bremfree(bp); 1306 bawrite(bp); 1307 VI_LOCK(vp); 1308 goto restartsync; 1309 } 1310 } 1311 1312 bufobj_wwait(bo, 0, 0); 1313 VI_UNLOCK(vp); 1314 vnode_pager_setsize(vp, length); 1315 1316 return (0); 1317 } 1318 1319 /* 1320 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1321 * a vnode. 1322 * 1323 * NOTE: We have to deal with the special case of a background bitmap 1324 * buffer, a situation where two buffers will have the same logical 1325 * block offset. We want (1) only the foreground buffer to be accessed 1326 * in a lookup and (2) must differentiate between the foreground and 1327 * background buffer in the splay tree algorithm because the splay 1328 * tree cannot normally handle multiple entities with the same 'index'. 1329 * We accomplish this by adding differentiating flags to the splay tree's 1330 * numerical domain. 1331 */ 1332 static 1333 struct buf * 1334 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1335 { 1336 struct buf dummy; 1337 struct buf *lefttreemax, *righttreemin, *y; 1338 1339 if (root == NULL) 1340 return (NULL); 1341 lefttreemax = righttreemin = &dummy; 1342 for (;;) { 1343 if (lblkno < root->b_lblkno || 1344 (lblkno == root->b_lblkno && 1345 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1346 if ((y = root->b_left) == NULL) 1347 break; 1348 if (lblkno < y->b_lblkno) { 1349 /* Rotate right. */ 1350 root->b_left = y->b_right; 1351 y->b_right = root; 1352 root = y; 1353 if ((y = root->b_left) == NULL) 1354 break; 1355 } 1356 /* Link into the new root's right tree. */ 1357 righttreemin->b_left = root; 1358 righttreemin = root; 1359 } else if (lblkno > root->b_lblkno || 1360 (lblkno == root->b_lblkno && 1361 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1362 if ((y = root->b_right) == NULL) 1363 break; 1364 if (lblkno > y->b_lblkno) { 1365 /* Rotate left. */ 1366 root->b_right = y->b_left; 1367 y->b_left = root; 1368 root = y; 1369 if ((y = root->b_right) == NULL) 1370 break; 1371 } 1372 /* Link into the new root's left tree. */ 1373 lefttreemax->b_right = root; 1374 lefttreemax = root; 1375 } else { 1376 break; 1377 } 1378 root = y; 1379 } 1380 /* Assemble the new root. */ 1381 lefttreemax->b_right = root->b_left; 1382 righttreemin->b_left = root->b_right; 1383 root->b_left = dummy.b_right; 1384 root->b_right = dummy.b_left; 1385 return (root); 1386 } 1387 1388 static void 1389 buf_vlist_remove(struct buf *bp) 1390 { 1391 struct buf *root; 1392 struct bufv *bv; 1393 1394 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1395 ASSERT_BO_LOCKED(bp->b_bufobj); 1396 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1397 (BX_VNDIRTY|BX_VNCLEAN), 1398 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1399 if (bp->b_xflags & BX_VNDIRTY) 1400 bv = &bp->b_bufobj->bo_dirty; 1401 else 1402 bv = &bp->b_bufobj->bo_clean; 1403 if (bp != bv->bv_root) { 1404 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1405 KASSERT(root == bp, ("splay lookup failed in remove")); 1406 } 1407 if (bp->b_left == NULL) { 1408 root = bp->b_right; 1409 } else { 1410 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1411 root->b_right = bp->b_right; 1412 } 1413 bv->bv_root = root; 1414 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1415 bv->bv_cnt--; 1416 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1417 } 1418 1419 /* 1420 * Add the buffer to the sorted clean or dirty block list using a 1421 * splay tree algorithm. 1422 * 1423 * NOTE: xflags is passed as a constant, optimizing this inline function! 1424 */ 1425 static void 1426 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1427 { 1428 struct buf *root; 1429 struct bufv *bv; 1430 1431 ASSERT_BO_LOCKED(bo); 1432 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1433 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1434 bp->b_xflags |= xflags; 1435 if (xflags & BX_VNDIRTY) 1436 bv = &bo->bo_dirty; 1437 else 1438 bv = &bo->bo_clean; 1439 1440 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1441 if (root == NULL) { 1442 bp->b_left = NULL; 1443 bp->b_right = NULL; 1444 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1445 } else if (bp->b_lblkno < root->b_lblkno || 1446 (bp->b_lblkno == root->b_lblkno && 1447 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1448 bp->b_left = root->b_left; 1449 bp->b_right = root; 1450 root->b_left = NULL; 1451 TAILQ_INSERT_BEFORE(root, bp, b_bobufs); 1452 } else { 1453 bp->b_right = root->b_right; 1454 bp->b_left = root; 1455 root->b_right = NULL; 1456 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs); 1457 } 1458 bv->bv_cnt++; 1459 bv->bv_root = bp; 1460 } 1461 1462 /* 1463 * Lookup a buffer using the splay tree. Note that we specifically avoid 1464 * shadow buffers used in background bitmap writes. 1465 * 1466 * This code isn't quite efficient as it could be because we are maintaining 1467 * two sorted lists and do not know which list the block resides in. 1468 * 1469 * During a "make buildworld" the desired buffer is found at one of 1470 * the roots more than 60% of the time. Thus, checking both roots 1471 * before performing either splay eliminates unnecessary splays on the 1472 * first tree splayed. 1473 */ 1474 struct buf * 1475 gbincore(struct bufobj *bo, daddr_t lblkno) 1476 { 1477 struct buf *bp; 1478 1479 ASSERT_BO_LOCKED(bo); 1480 if ((bp = bo->bo_clean.bv_root) != NULL && 1481 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1482 return (bp); 1483 if ((bp = bo->bo_dirty.bv_root) != NULL && 1484 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1485 return (bp); 1486 if ((bp = bo->bo_clean.bv_root) != NULL) { 1487 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp); 1488 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1489 return (bp); 1490 } 1491 if ((bp = bo->bo_dirty.bv_root) != NULL) { 1492 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp); 1493 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1494 return (bp); 1495 } 1496 return (NULL); 1497 } 1498 1499 /* 1500 * Associate a buffer with a vnode. 1501 */ 1502 void 1503 bgetvp(struct vnode *vp, struct buf *bp) 1504 { 1505 1506 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 1507 1508 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 1509 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 1510 ("bgetvp: bp already attached! %p", bp)); 1511 1512 ASSERT_VI_LOCKED(vp, "bgetvp"); 1513 vholdl(vp); 1514 if (VFS_NEEDSGIANT(vp->v_mount) || 1515 vp->v_bufobj.bo_flag & BO_NEEDSGIANT) 1516 bp->b_flags |= B_NEEDSGIANT; 1517 bp->b_vp = vp; 1518 bp->b_bufobj = &vp->v_bufobj; 1519 /* 1520 * Insert onto list for new vnode. 1521 */ 1522 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN); 1523 } 1524 1525 /* 1526 * Disassociate a buffer from a vnode. 1527 */ 1528 int 1529 brelvp(struct buf *bp) 1530 { 1531 struct bufobj *bo; 1532 struct vnode *vp; 1533 int waiters; 1534 1535 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 1536 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1537 1538 /* 1539 * Delete from old vnode list, if on one. 1540 */ 1541 vp = bp->b_vp; /* XXX */ 1542 bo = bp->b_bufobj; 1543 BO_LOCK(bo); 1544 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1545 buf_vlist_remove(bp); 1546 else 1547 panic("brelvp: Buffer %p not on queue.", bp); 1548 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1549 bo->bo_flag &= ~BO_ONWORKLST; 1550 mtx_lock(&sync_mtx); 1551 LIST_REMOVE(bo, bo_synclist); 1552 syncer_worklist_len--; 1553 mtx_unlock(&sync_mtx); 1554 } 1555 bp->b_flags &= ~B_NEEDSGIANT; 1556 bp->b_vp = NULL; 1557 bp->b_bufobj = NULL; 1558 waiters = bp->b_waiters; 1559 vdropl(vp); 1560 1561 return (waiters); 1562 } 1563 1564 /* 1565 * Add an item to the syncer work queue. 1566 */ 1567 static void 1568 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 1569 { 1570 int slot; 1571 1572 ASSERT_BO_LOCKED(bo); 1573 1574 mtx_lock(&sync_mtx); 1575 if (bo->bo_flag & BO_ONWORKLST) 1576 LIST_REMOVE(bo, bo_synclist); 1577 else { 1578 bo->bo_flag |= BO_ONWORKLST; 1579 syncer_worklist_len++; 1580 } 1581 1582 if (delay > syncer_maxdelay - 2) 1583 delay = syncer_maxdelay - 2; 1584 slot = (syncer_delayno + delay) & syncer_mask; 1585 1586 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 1587 mtx_unlock(&sync_mtx); 1588 } 1589 1590 static int 1591 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1592 { 1593 int error, len; 1594 1595 mtx_lock(&sync_mtx); 1596 len = syncer_worklist_len - sync_vnode_count; 1597 mtx_unlock(&sync_mtx); 1598 error = SYSCTL_OUT(req, &len, sizeof(len)); 1599 return (error); 1600 } 1601 1602 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1603 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1604 1605 static struct proc *updateproc; 1606 static void sched_sync(void); 1607 static struct kproc_desc up_kp = { 1608 "syncer", 1609 sched_sync, 1610 &updateproc 1611 }; 1612 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1613 1614 static int 1615 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 1616 { 1617 struct vnode *vp; 1618 struct mount *mp; 1619 int vfslocked; 1620 1621 vfslocked = 0; 1622 restart: 1623 *bo = LIST_FIRST(slp); 1624 if (*bo == NULL) { 1625 VFS_UNLOCK_GIANT(vfslocked); 1626 return (0); 1627 } 1628 vp = (*bo)->__bo_vnode; /* XXX */ 1629 if (VFS_NEEDSGIANT(vp->v_mount)) { 1630 if (!vfslocked) { 1631 vfslocked = 1; 1632 if (mtx_trylock(&Giant) == 0) { 1633 mtx_unlock(&sync_mtx); 1634 mtx_lock(&Giant); 1635 mtx_lock(&sync_mtx); 1636 goto restart; 1637 } 1638 } 1639 } else { 1640 VFS_UNLOCK_GIANT(vfslocked); 1641 vfslocked = 0; 1642 } 1643 if (VOP_ISLOCKED(vp) != 0) { 1644 VFS_UNLOCK_GIANT(vfslocked); 1645 return (1); 1646 } 1647 if (VI_TRYLOCK(vp) == 0) { 1648 VFS_UNLOCK_GIANT(vfslocked); 1649 return (1); 1650 } 1651 /* 1652 * We use vhold in case the vnode does not 1653 * successfully sync. vhold prevents the vnode from 1654 * going away when we unlock the sync_mtx so that 1655 * we can acquire the vnode interlock. 1656 */ 1657 vholdl(vp); 1658 mtx_unlock(&sync_mtx); 1659 VI_UNLOCK(vp); 1660 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1661 vdrop(vp); 1662 VFS_UNLOCK_GIANT(vfslocked); 1663 mtx_lock(&sync_mtx); 1664 return (1); 1665 } 1666 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1667 (void) VOP_FSYNC(vp, MNT_LAZY, td); 1668 VOP_UNLOCK(vp, 0); 1669 vn_finished_write(mp); 1670 VI_LOCK(vp); 1671 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 1672 /* 1673 * Put us back on the worklist. The worklist 1674 * routine will remove us from our current 1675 * position and then add us back in at a later 1676 * position. 1677 */ 1678 vn_syncer_add_to_worklist(*bo, syncdelay); 1679 } 1680 vdropl(vp); 1681 VFS_UNLOCK_GIANT(vfslocked); 1682 mtx_lock(&sync_mtx); 1683 return (0); 1684 } 1685 1686 /* 1687 * System filesystem synchronizer daemon. 1688 */ 1689 static void 1690 sched_sync(void) 1691 { 1692 struct synclist *next; 1693 struct synclist *slp; 1694 struct bufobj *bo; 1695 long starttime; 1696 struct thread *td = curthread; 1697 static int dummychan; 1698 int last_work_seen; 1699 int net_worklist_len; 1700 int syncer_final_iter; 1701 int first_printf; 1702 int error; 1703 1704 last_work_seen = 0; 1705 syncer_final_iter = 0; 1706 first_printf = 1; 1707 syncer_state = SYNCER_RUNNING; 1708 starttime = time_uptime; 1709 td->td_pflags |= TDP_NORUNNINGBUF; 1710 1711 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 1712 SHUTDOWN_PRI_LAST); 1713 1714 mtx_lock(&sync_mtx); 1715 for (;;) { 1716 if (syncer_state == SYNCER_FINAL_DELAY && 1717 syncer_final_iter == 0) { 1718 mtx_unlock(&sync_mtx); 1719 kproc_suspend_check(td->td_proc); 1720 mtx_lock(&sync_mtx); 1721 } 1722 net_worklist_len = syncer_worklist_len - sync_vnode_count; 1723 if (syncer_state != SYNCER_RUNNING && 1724 starttime != time_uptime) { 1725 if (first_printf) { 1726 printf("\nSyncing disks, vnodes remaining..."); 1727 first_printf = 0; 1728 } 1729 printf("%d ", net_worklist_len); 1730 } 1731 starttime = time_uptime; 1732 1733 /* 1734 * Push files whose dirty time has expired. Be careful 1735 * of interrupt race on slp queue. 1736 * 1737 * Skip over empty worklist slots when shutting down. 1738 */ 1739 do { 1740 slp = &syncer_workitem_pending[syncer_delayno]; 1741 syncer_delayno += 1; 1742 if (syncer_delayno == syncer_maxdelay) 1743 syncer_delayno = 0; 1744 next = &syncer_workitem_pending[syncer_delayno]; 1745 /* 1746 * If the worklist has wrapped since the 1747 * it was emptied of all but syncer vnodes, 1748 * switch to the FINAL_DELAY state and run 1749 * for one more second. 1750 */ 1751 if (syncer_state == SYNCER_SHUTTING_DOWN && 1752 net_worklist_len == 0 && 1753 last_work_seen == syncer_delayno) { 1754 syncer_state = SYNCER_FINAL_DELAY; 1755 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 1756 } 1757 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 1758 syncer_worklist_len > 0); 1759 1760 /* 1761 * Keep track of the last time there was anything 1762 * on the worklist other than syncer vnodes. 1763 * Return to the SHUTTING_DOWN state if any 1764 * new work appears. 1765 */ 1766 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 1767 last_work_seen = syncer_delayno; 1768 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 1769 syncer_state = SYNCER_SHUTTING_DOWN; 1770 while (!LIST_EMPTY(slp)) { 1771 error = sync_vnode(slp, &bo, td); 1772 if (error == 1) { 1773 LIST_REMOVE(bo, bo_synclist); 1774 LIST_INSERT_HEAD(next, bo, bo_synclist); 1775 continue; 1776 } 1777 } 1778 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 1779 syncer_final_iter--; 1780 /* 1781 * The variable rushjob allows the kernel to speed up the 1782 * processing of the filesystem syncer process. A rushjob 1783 * value of N tells the filesystem syncer to process the next 1784 * N seconds worth of work on its queue ASAP. Currently rushjob 1785 * is used by the soft update code to speed up the filesystem 1786 * syncer process when the incore state is getting so far 1787 * ahead of the disk that the kernel memory pool is being 1788 * threatened with exhaustion. 1789 */ 1790 if (rushjob > 0) { 1791 rushjob -= 1; 1792 continue; 1793 } 1794 /* 1795 * Just sleep for a short period of time between 1796 * iterations when shutting down to allow some I/O 1797 * to happen. 1798 * 1799 * If it has taken us less than a second to process the 1800 * current work, then wait. Otherwise start right over 1801 * again. We can still lose time if any single round 1802 * takes more than two seconds, but it does not really 1803 * matter as we are just trying to generally pace the 1804 * filesystem activity. 1805 */ 1806 if (syncer_state != SYNCER_RUNNING) 1807 msleep(&dummychan, &sync_mtx, PPAUSE, "syncfnl", 1808 hz / SYNCER_SHUTDOWN_SPEEDUP); 1809 else if (time_uptime == starttime) 1810 msleep(&lbolt, &sync_mtx, PPAUSE, "syncer", 0); 1811 } 1812 } 1813 1814 /* 1815 * Request the syncer daemon to speed up its work. 1816 * We never push it to speed up more than half of its 1817 * normal turn time, otherwise it could take over the cpu. 1818 */ 1819 int 1820 speedup_syncer(void) 1821 { 1822 struct thread *td; 1823 int ret = 0; 1824 1825 td = FIRST_THREAD_IN_PROC(updateproc); 1826 mtx_lock(&sync_mtx); 1827 if (rushjob < syncdelay / 2) { 1828 rushjob += 1; 1829 stat_rush_requests += 1; 1830 ret = 1; 1831 } 1832 mtx_unlock(&sync_mtx); 1833 sleepq_remove(td, &lbolt); 1834 return (ret); 1835 } 1836 1837 /* 1838 * Tell the syncer to speed up its work and run though its work 1839 * list several times, then tell it to shut down. 1840 */ 1841 static void 1842 syncer_shutdown(void *arg, int howto) 1843 { 1844 struct thread *td; 1845 1846 if (howto & RB_NOSYNC) 1847 return; 1848 td = FIRST_THREAD_IN_PROC(updateproc); 1849 mtx_lock(&sync_mtx); 1850 syncer_state = SYNCER_SHUTTING_DOWN; 1851 rushjob = 0; 1852 mtx_unlock(&sync_mtx); 1853 sleepq_remove(td, &lbolt); 1854 kproc_shutdown(arg, howto); 1855 } 1856 1857 /* 1858 * Reassign a buffer from one vnode to another. 1859 * Used to assign file specific control information 1860 * (indirect blocks) to the vnode to which they belong. 1861 */ 1862 void 1863 reassignbuf(struct buf *bp) 1864 { 1865 struct vnode *vp; 1866 struct bufobj *bo; 1867 int delay; 1868 #ifdef INVARIANTS 1869 struct bufv *bv; 1870 #endif 1871 1872 vp = bp->b_vp; 1873 bo = bp->b_bufobj; 1874 ++reassignbufcalls; 1875 1876 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 1877 bp, bp->b_vp, bp->b_flags); 1878 /* 1879 * B_PAGING flagged buffers cannot be reassigned because their vp 1880 * is not fully linked in. 1881 */ 1882 if (bp->b_flags & B_PAGING) 1883 panic("cannot reassign paging buffer"); 1884 1885 /* 1886 * Delete from old vnode list, if on one. 1887 */ 1888 VI_LOCK(vp); 1889 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1890 buf_vlist_remove(bp); 1891 else 1892 panic("reassignbuf: Buffer %p not on queue.", bp); 1893 /* 1894 * If dirty, put on list of dirty buffers; otherwise insert onto list 1895 * of clean buffers. 1896 */ 1897 if (bp->b_flags & B_DELWRI) { 1898 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 1899 switch (vp->v_type) { 1900 case VDIR: 1901 delay = dirdelay; 1902 break; 1903 case VCHR: 1904 delay = metadelay; 1905 break; 1906 default: 1907 delay = filedelay; 1908 } 1909 vn_syncer_add_to_worklist(bo, delay); 1910 } 1911 buf_vlist_add(bp, bo, BX_VNDIRTY); 1912 } else { 1913 buf_vlist_add(bp, bo, BX_VNCLEAN); 1914 1915 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1916 mtx_lock(&sync_mtx); 1917 LIST_REMOVE(bo, bo_synclist); 1918 syncer_worklist_len--; 1919 mtx_unlock(&sync_mtx); 1920 bo->bo_flag &= ~BO_ONWORKLST; 1921 } 1922 } 1923 #ifdef INVARIANTS 1924 bv = &bo->bo_clean; 1925 bp = TAILQ_FIRST(&bv->bv_hd); 1926 KASSERT(bp == NULL || bp->b_bufobj == bo, 1927 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1928 bp = TAILQ_LAST(&bv->bv_hd, buflists); 1929 KASSERT(bp == NULL || bp->b_bufobj == bo, 1930 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1931 bv = &bo->bo_dirty; 1932 bp = TAILQ_FIRST(&bv->bv_hd); 1933 KASSERT(bp == NULL || bp->b_bufobj == bo, 1934 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1935 bp = TAILQ_LAST(&bv->bv_hd, buflists); 1936 KASSERT(bp == NULL || bp->b_bufobj == bo, 1937 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1938 #endif 1939 VI_UNLOCK(vp); 1940 } 1941 1942 /* 1943 * Increment the use and hold counts on the vnode, taking care to reference 1944 * the driver's usecount if this is a chardev. The vholdl() will remove 1945 * the vnode from the free list if it is presently free. Requires the 1946 * vnode interlock and returns with it held. 1947 */ 1948 static void 1949 v_incr_usecount(struct vnode *vp) 1950 { 1951 1952 CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n", 1953 vp, vp->v_holdcnt, vp->v_usecount); 1954 vp->v_usecount++; 1955 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1956 dev_lock(); 1957 vp->v_rdev->si_usecount++; 1958 dev_unlock(); 1959 } 1960 vholdl(vp); 1961 } 1962 1963 /* 1964 * Turn a holdcnt into a use+holdcnt such that only one call to 1965 * v_decr_usecount is needed. 1966 */ 1967 static void 1968 v_upgrade_usecount(struct vnode *vp) 1969 { 1970 1971 CTR3(KTR_VFS, "v_upgrade_usecount: vp %p holdcnt %d usecount %d\n", 1972 vp, vp->v_holdcnt, vp->v_usecount); 1973 vp->v_usecount++; 1974 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1975 dev_lock(); 1976 vp->v_rdev->si_usecount++; 1977 dev_unlock(); 1978 } 1979 } 1980 1981 /* 1982 * Decrement the vnode use and hold count along with the driver's usecount 1983 * if this is a chardev. The vdropl() below releases the vnode interlock 1984 * as it may free the vnode. 1985 */ 1986 static void 1987 v_decr_usecount(struct vnode *vp) 1988 { 1989 1990 CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n", 1991 vp, vp->v_holdcnt, vp->v_usecount); 1992 ASSERT_VI_LOCKED(vp, __FUNCTION__); 1993 VNASSERT(vp->v_usecount > 0, vp, 1994 ("v_decr_usecount: negative usecount")); 1995 vp->v_usecount--; 1996 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1997 dev_lock(); 1998 vp->v_rdev->si_usecount--; 1999 dev_unlock(); 2000 } 2001 vdropl(vp); 2002 } 2003 2004 /* 2005 * Decrement only the use count and driver use count. This is intended to 2006 * be paired with a follow on vdropl() to release the remaining hold count. 2007 * In this way we may vgone() a vnode with a 0 usecount without risk of 2008 * having it end up on a free list because the hold count is kept above 0. 2009 */ 2010 static void 2011 v_decr_useonly(struct vnode *vp) 2012 { 2013 2014 CTR3(KTR_VFS, "v_decr_useonly: vp %p holdcnt %d usecount %d\n", 2015 vp, vp->v_holdcnt, vp->v_usecount); 2016 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2017 VNASSERT(vp->v_usecount > 0, vp, 2018 ("v_decr_useonly: negative usecount")); 2019 vp->v_usecount--; 2020 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2021 dev_lock(); 2022 vp->v_rdev->si_usecount--; 2023 dev_unlock(); 2024 } 2025 } 2026 2027 /* 2028 * Grab a particular vnode from the free list, increment its 2029 * reference count and lock it. The vnode lock bit is set if the 2030 * vnode is being eliminated in vgone. The process is awakened 2031 * when the transition is completed, and an error returned to 2032 * indicate that the vnode is no longer usable (possibly having 2033 * been changed to a new filesystem type). 2034 */ 2035 int 2036 vget(struct vnode *vp, int flags, struct thread *td) 2037 { 2038 int oweinact; 2039 int oldflags; 2040 int error; 2041 2042 error = 0; 2043 oldflags = flags; 2044 oweinact = 0; 2045 VFS_ASSERT_GIANT(vp->v_mount); 2046 if ((flags & LK_INTERLOCK) == 0) 2047 VI_LOCK(vp); 2048 /* 2049 * If the inactive call was deferred because vput() was called 2050 * with a shared lock, we have to do it here before another thread 2051 * gets a reference to data that should be dead. 2052 */ 2053 if (vp->v_iflag & VI_OWEINACT) { 2054 if (flags & LK_NOWAIT) { 2055 VI_UNLOCK(vp); 2056 return (EBUSY); 2057 } 2058 flags &= ~LK_TYPE_MASK; 2059 flags |= LK_EXCLUSIVE; 2060 oweinact = 1; 2061 } 2062 vholdl(vp); 2063 if ((error = vn_lock(vp, flags | LK_INTERLOCK)) != 0) { 2064 vdrop(vp); 2065 return (error); 2066 } 2067 VI_LOCK(vp); 2068 /* Upgrade our holdcnt to a usecount. */ 2069 v_upgrade_usecount(vp); 2070 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2071 panic("vget: vn_lock failed to return ENOENT\n"); 2072 if (oweinact) { 2073 if (vp->v_iflag & VI_OWEINACT) 2074 vinactive(vp, td); 2075 VI_UNLOCK(vp); 2076 if ((oldflags & LK_TYPE_MASK) == 0) 2077 VOP_UNLOCK(vp, 0); 2078 } else 2079 VI_UNLOCK(vp); 2080 return (0); 2081 } 2082 2083 /* 2084 * Increase the reference count of a vnode. 2085 */ 2086 void 2087 vref(struct vnode *vp) 2088 { 2089 2090 VI_LOCK(vp); 2091 v_incr_usecount(vp); 2092 VI_UNLOCK(vp); 2093 } 2094 2095 /* 2096 * Return reference count of a vnode. 2097 * 2098 * The results of this call are only guaranteed when some mechanism other 2099 * than the VI lock is used to stop other processes from gaining references 2100 * to the vnode. This may be the case if the caller holds the only reference. 2101 * This is also useful when stale data is acceptable as race conditions may 2102 * be accounted for by some other means. 2103 */ 2104 int 2105 vrefcnt(struct vnode *vp) 2106 { 2107 int usecnt; 2108 2109 VI_LOCK(vp); 2110 usecnt = vp->v_usecount; 2111 VI_UNLOCK(vp); 2112 2113 return (usecnt); 2114 } 2115 2116 2117 /* 2118 * Vnode put/release. 2119 * If count drops to zero, call inactive routine and return to freelist. 2120 */ 2121 void 2122 vrele(struct vnode *vp) 2123 { 2124 struct thread *td = curthread; /* XXX */ 2125 2126 KASSERT(vp != NULL, ("vrele: null vp")); 2127 VFS_ASSERT_GIANT(vp->v_mount); 2128 2129 VI_LOCK(vp); 2130 2131 /* Skip this v_writecount check if we're going to panic below. */ 2132 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2133 ("vrele: missed vn_close")); 2134 2135 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2136 vp->v_usecount == 1)) { 2137 v_decr_usecount(vp); 2138 return; 2139 } 2140 if (vp->v_usecount != 1) { 2141 #ifdef DIAGNOSTIC 2142 vprint("vrele: negative ref count", vp); 2143 #endif 2144 VI_UNLOCK(vp); 2145 panic("vrele: negative ref cnt"); 2146 } 2147 /* 2148 * We want to hold the vnode until the inactive finishes to 2149 * prevent vgone() races. We drop the use count here and the 2150 * hold count below when we're done. 2151 */ 2152 v_decr_useonly(vp); 2153 /* 2154 * We must call VOP_INACTIVE with the node locked. Mark 2155 * as VI_DOINGINACT to avoid recursion. 2156 */ 2157 vp->v_iflag |= VI_OWEINACT; 2158 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK) == 0) { 2159 VI_LOCK(vp); 2160 if (vp->v_usecount > 0) 2161 vp->v_iflag &= ~VI_OWEINACT; 2162 if (vp->v_iflag & VI_OWEINACT) 2163 vinactive(vp, td); 2164 VOP_UNLOCK(vp, 0); 2165 } else { 2166 VI_LOCK(vp); 2167 if (vp->v_usecount > 0) 2168 vp->v_iflag &= ~VI_OWEINACT; 2169 } 2170 vdropl(vp); 2171 } 2172 2173 /* 2174 * Release an already locked vnode. This give the same effects as 2175 * unlock+vrele(), but takes less time and avoids releasing and 2176 * re-aquiring the lock (as vrele() acquires the lock internally.) 2177 */ 2178 void 2179 vput(struct vnode *vp) 2180 { 2181 struct thread *td = curthread; /* XXX */ 2182 int error; 2183 2184 KASSERT(vp != NULL, ("vput: null vp")); 2185 ASSERT_VOP_LOCKED(vp, "vput"); 2186 VFS_ASSERT_GIANT(vp->v_mount); 2187 VI_LOCK(vp); 2188 /* Skip this v_writecount check if we're going to panic below. */ 2189 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2190 ("vput: missed vn_close")); 2191 error = 0; 2192 2193 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2194 vp->v_usecount == 1)) { 2195 VOP_UNLOCK(vp, 0); 2196 v_decr_usecount(vp); 2197 return; 2198 } 2199 2200 if (vp->v_usecount != 1) { 2201 #ifdef DIAGNOSTIC 2202 vprint("vput: negative ref count", vp); 2203 #endif 2204 panic("vput: negative ref cnt"); 2205 } 2206 /* 2207 * We want to hold the vnode until the inactive finishes to 2208 * prevent vgone() races. We drop the use count here and the 2209 * hold count below when we're done. 2210 */ 2211 v_decr_useonly(vp); 2212 vp->v_iflag |= VI_OWEINACT; 2213 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2214 error = VOP_LOCK(vp, LK_UPGRADE|LK_INTERLOCK|LK_NOWAIT); 2215 VI_LOCK(vp); 2216 if (error) { 2217 if (vp->v_usecount > 0) 2218 vp->v_iflag &= ~VI_OWEINACT; 2219 goto done; 2220 } 2221 } 2222 if (vp->v_usecount > 0) 2223 vp->v_iflag &= ~VI_OWEINACT; 2224 if (vp->v_iflag & VI_OWEINACT) 2225 vinactive(vp, td); 2226 VOP_UNLOCK(vp, 0); 2227 done: 2228 vdropl(vp); 2229 } 2230 2231 /* 2232 * Somebody doesn't want the vnode recycled. 2233 */ 2234 void 2235 vhold(struct vnode *vp) 2236 { 2237 2238 VI_LOCK(vp); 2239 vholdl(vp); 2240 VI_UNLOCK(vp); 2241 } 2242 2243 void 2244 vholdl(struct vnode *vp) 2245 { 2246 2247 vp->v_holdcnt++; 2248 if (VSHOULDBUSY(vp)) 2249 vbusy(vp); 2250 } 2251 2252 /* 2253 * Note that there is one less who cares about this vnode. vdrop() is the 2254 * opposite of vhold(). 2255 */ 2256 void 2257 vdrop(struct vnode *vp) 2258 { 2259 2260 VI_LOCK(vp); 2261 vdropl(vp); 2262 } 2263 2264 /* 2265 * Drop the hold count of the vnode. If this is the last reference to 2266 * the vnode we will free it if it has been vgone'd otherwise it is 2267 * placed on the free list. 2268 */ 2269 void 2270 vdropl(struct vnode *vp) 2271 { 2272 2273 ASSERT_VI_LOCKED(vp, "vdropl"); 2274 if (vp->v_holdcnt <= 0) 2275 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2276 vp->v_holdcnt--; 2277 if (vp->v_holdcnt == 0) { 2278 if (vp->v_iflag & VI_DOOMED) { 2279 vdestroy(vp); 2280 return; 2281 } else 2282 vfree(vp); 2283 } 2284 VI_UNLOCK(vp); 2285 } 2286 2287 /* 2288 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 2289 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 2290 * OWEINACT tracks whether a vnode missed a call to inactive due to a 2291 * failed lock upgrade. 2292 */ 2293 static void 2294 vinactive(struct vnode *vp, struct thread *td) 2295 { 2296 2297 ASSERT_VOP_LOCKED(vp, "vinactive"); 2298 ASSERT_VI_LOCKED(vp, "vinactive"); 2299 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 2300 ("vinactive: recursed on VI_DOINGINACT")); 2301 vp->v_iflag |= VI_DOINGINACT; 2302 vp->v_iflag &= ~VI_OWEINACT; 2303 VI_UNLOCK(vp); 2304 VOP_INACTIVE(vp, td); 2305 VI_LOCK(vp); 2306 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 2307 ("vinactive: lost VI_DOINGINACT")); 2308 vp->v_iflag &= ~VI_DOINGINACT; 2309 } 2310 2311 /* 2312 * Remove any vnodes in the vnode table belonging to mount point mp. 2313 * 2314 * If FORCECLOSE is not specified, there should not be any active ones, 2315 * return error if any are found (nb: this is a user error, not a 2316 * system error). If FORCECLOSE is specified, detach any active vnodes 2317 * that are found. 2318 * 2319 * If WRITECLOSE is set, only flush out regular file vnodes open for 2320 * writing. 2321 * 2322 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2323 * 2324 * `rootrefs' specifies the base reference count for the root vnode 2325 * of this filesystem. The root vnode is considered busy if its 2326 * v_usecount exceeds this value. On a successful return, vflush(, td) 2327 * will call vrele() on the root vnode exactly rootrefs times. 2328 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2329 * be zero. 2330 */ 2331 #ifdef DIAGNOSTIC 2332 static int busyprt = 0; /* print out busy vnodes */ 2333 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2334 #endif 2335 2336 int 2337 vflush( struct mount *mp, int rootrefs, int flags, struct thread *td) 2338 { 2339 struct vnode *vp, *mvp, *rootvp = NULL; 2340 struct vattr vattr; 2341 int busy = 0, error; 2342 2343 CTR1(KTR_VFS, "vflush: mp %p", mp); 2344 if (rootrefs > 0) { 2345 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2346 ("vflush: bad args")); 2347 /* 2348 * Get the filesystem root vnode. We can vput() it 2349 * immediately, since with rootrefs > 0, it won't go away. 2350 */ 2351 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp, td)) != 0) 2352 return (error); 2353 vput(rootvp); 2354 2355 } 2356 MNT_ILOCK(mp); 2357 loop: 2358 MNT_VNODE_FOREACH(vp, mp, mvp) { 2359 2360 VI_LOCK(vp); 2361 vholdl(vp); 2362 MNT_IUNLOCK(mp); 2363 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 2364 if (error) { 2365 vdrop(vp); 2366 MNT_ILOCK(mp); 2367 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp); 2368 goto loop; 2369 } 2370 /* 2371 * Skip over a vnodes marked VV_SYSTEM. 2372 */ 2373 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2374 VOP_UNLOCK(vp, 0); 2375 vdrop(vp); 2376 MNT_ILOCK(mp); 2377 continue; 2378 } 2379 /* 2380 * If WRITECLOSE is set, flush out unlinked but still open 2381 * files (even if open only for reading) and regular file 2382 * vnodes open for writing. 2383 */ 2384 if (flags & WRITECLOSE) { 2385 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2386 VI_LOCK(vp); 2387 2388 if ((vp->v_type == VNON || 2389 (error == 0 && vattr.va_nlink > 0)) && 2390 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2391 VOP_UNLOCK(vp, 0); 2392 vdropl(vp); 2393 MNT_ILOCK(mp); 2394 continue; 2395 } 2396 } else 2397 VI_LOCK(vp); 2398 /* 2399 * With v_usecount == 0, all we need to do is clear out the 2400 * vnode data structures and we are done. 2401 * 2402 * If FORCECLOSE is set, forcibly close the vnode. 2403 */ 2404 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 2405 VNASSERT(vp->v_usecount == 0 || 2406 (vp->v_type != VCHR && vp->v_type != VBLK), vp, 2407 ("device VNODE %p is FORCECLOSED", vp)); 2408 vgonel(vp); 2409 } else { 2410 busy++; 2411 #ifdef DIAGNOSTIC 2412 if (busyprt) 2413 vprint("vflush: busy vnode", vp); 2414 #endif 2415 } 2416 VOP_UNLOCK(vp, 0); 2417 vdropl(vp); 2418 MNT_ILOCK(mp); 2419 } 2420 MNT_IUNLOCK(mp); 2421 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2422 /* 2423 * If just the root vnode is busy, and if its refcount 2424 * is equal to `rootrefs', then go ahead and kill it. 2425 */ 2426 VI_LOCK(rootvp); 2427 KASSERT(busy > 0, ("vflush: not busy")); 2428 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 2429 ("vflush: usecount %d < rootrefs %d", 2430 rootvp->v_usecount, rootrefs)); 2431 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2432 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 2433 vgone(rootvp); 2434 VOP_UNLOCK(rootvp, 0); 2435 busy = 0; 2436 } else 2437 VI_UNLOCK(rootvp); 2438 } 2439 if (busy) 2440 return (EBUSY); 2441 for (; rootrefs > 0; rootrefs--) 2442 vrele(rootvp); 2443 return (0); 2444 } 2445 2446 /* 2447 * Recycle an unused vnode to the front of the free list. 2448 */ 2449 int 2450 vrecycle(struct vnode *vp, struct thread *td) 2451 { 2452 int recycled; 2453 2454 ASSERT_VOP_LOCKED(vp, "vrecycle"); 2455 recycled = 0; 2456 VI_LOCK(vp); 2457 if (vp->v_usecount == 0) { 2458 recycled = 1; 2459 vgonel(vp); 2460 } 2461 VI_UNLOCK(vp); 2462 return (recycled); 2463 } 2464 2465 /* 2466 * Eliminate all activity associated with a vnode 2467 * in preparation for reuse. 2468 */ 2469 void 2470 vgone(struct vnode *vp) 2471 { 2472 VI_LOCK(vp); 2473 vgonel(vp); 2474 VI_UNLOCK(vp); 2475 } 2476 2477 /* 2478 * vgone, with the vp interlock held. 2479 */ 2480 void 2481 vgonel(struct vnode *vp) 2482 { 2483 struct thread *td; 2484 int oweinact; 2485 int active; 2486 struct mount *mp; 2487 2488 CTR1(KTR_VFS, "vgonel: vp %p", vp); 2489 ASSERT_VOP_LOCKED(vp, "vgonel"); 2490 ASSERT_VI_LOCKED(vp, "vgonel"); 2491 VNASSERT(vp->v_holdcnt, vp, 2492 ("vgonel: vp %p has no reference.", vp)); 2493 td = curthread; 2494 2495 /* 2496 * Don't vgonel if we're already doomed. 2497 */ 2498 if (vp->v_iflag & VI_DOOMED) 2499 return; 2500 vp->v_iflag |= VI_DOOMED; 2501 /* 2502 * Check to see if the vnode is in use. If so, we have to call 2503 * VOP_CLOSE() and VOP_INACTIVE(). 2504 */ 2505 active = vp->v_usecount; 2506 oweinact = (vp->v_iflag & VI_OWEINACT); 2507 VI_UNLOCK(vp); 2508 /* 2509 * Clean out any buffers associated with the vnode. 2510 * If the flush fails, just toss the buffers. 2511 */ 2512 mp = NULL; 2513 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 2514 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 2515 if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0) 2516 vinvalbuf(vp, 0, td, 0, 0); 2517 2518 /* 2519 * If purging an active vnode, it must be closed and 2520 * deactivated before being reclaimed. 2521 */ 2522 if (active) 2523 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2524 if (oweinact || active) { 2525 VI_LOCK(vp); 2526 if ((vp->v_iflag & VI_DOINGINACT) == 0) 2527 vinactive(vp, td); 2528 VI_UNLOCK(vp); 2529 } 2530 /* 2531 * Reclaim the vnode. 2532 */ 2533 if (VOP_RECLAIM(vp, td)) 2534 panic("vgone: cannot reclaim"); 2535 if (mp != NULL) 2536 vn_finished_secondary_write(mp); 2537 VNASSERT(vp->v_object == NULL, vp, 2538 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 2539 /* 2540 * Delete from old mount point vnode list. 2541 */ 2542 delmntque(vp); 2543 cache_purge(vp); 2544 /* 2545 * Done with purge, reset to the standard lock and invalidate 2546 * the vnode. 2547 */ 2548 VI_LOCK(vp); 2549 vp->v_vnlock = &vp->v_lock; 2550 vp->v_op = &dead_vnodeops; 2551 vp->v_tag = "none"; 2552 vp->v_type = VBAD; 2553 } 2554 2555 /* 2556 * Calculate the total number of references to a special device. 2557 */ 2558 int 2559 vcount(struct vnode *vp) 2560 { 2561 int count; 2562 2563 dev_lock(); 2564 count = vp->v_rdev->si_usecount; 2565 dev_unlock(); 2566 return (count); 2567 } 2568 2569 /* 2570 * Same as above, but using the struct cdev *as argument 2571 */ 2572 int 2573 count_dev(struct cdev *dev) 2574 { 2575 int count; 2576 2577 dev_lock(); 2578 count = dev->si_usecount; 2579 dev_unlock(); 2580 return(count); 2581 } 2582 2583 /* 2584 * Print out a description of a vnode. 2585 */ 2586 static char *typename[] = 2587 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 2588 "VMARKER"}; 2589 2590 void 2591 vn_printf(struct vnode *vp, const char *fmt, ...) 2592 { 2593 va_list ap; 2594 char buf[256], buf2[16]; 2595 u_long flags; 2596 2597 va_start(ap, fmt); 2598 vprintf(fmt, ap); 2599 va_end(ap); 2600 printf("%p: ", (void *)vp); 2601 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 2602 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 2603 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 2604 buf[0] = '\0'; 2605 buf[1] = '\0'; 2606 if (vp->v_vflag & VV_ROOT) 2607 strlcat(buf, "|VV_ROOT", sizeof(buf)); 2608 if (vp->v_vflag & VV_ISTTY) 2609 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 2610 if (vp->v_vflag & VV_NOSYNC) 2611 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 2612 if (vp->v_vflag & VV_CACHEDLABEL) 2613 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 2614 if (vp->v_vflag & VV_TEXT) 2615 strlcat(buf, "|VV_TEXT", sizeof(buf)); 2616 if (vp->v_vflag & VV_COPYONWRITE) 2617 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 2618 if (vp->v_vflag & VV_SYSTEM) 2619 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 2620 if (vp->v_vflag & VV_PROCDEP) 2621 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 2622 if (vp->v_vflag & VV_NOKNOTE) 2623 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 2624 if (vp->v_vflag & VV_DELETED) 2625 strlcat(buf, "|VV_DELETED", sizeof(buf)); 2626 if (vp->v_vflag & VV_MD) 2627 strlcat(buf, "|VV_MD", sizeof(buf)); 2628 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | 2629 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 2630 VV_NOKNOTE | VV_DELETED | VV_MD); 2631 if (flags != 0) { 2632 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 2633 strlcat(buf, buf2, sizeof(buf)); 2634 } 2635 if (vp->v_iflag & VI_MOUNT) 2636 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 2637 if (vp->v_iflag & VI_AGE) 2638 strlcat(buf, "|VI_AGE", sizeof(buf)); 2639 if (vp->v_iflag & VI_DOOMED) 2640 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 2641 if (vp->v_iflag & VI_FREE) 2642 strlcat(buf, "|VI_FREE", sizeof(buf)); 2643 if (vp->v_iflag & VI_OBJDIRTY) 2644 strlcat(buf, "|VI_OBJDIRTY", sizeof(buf)); 2645 if (vp->v_iflag & VI_DOINGINACT) 2646 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 2647 if (vp->v_iflag & VI_OWEINACT) 2648 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 2649 flags = vp->v_iflag & ~(VI_MOUNT | VI_AGE | VI_DOOMED | VI_FREE | 2650 VI_OBJDIRTY | VI_DOINGINACT | VI_OWEINACT); 2651 if (flags != 0) { 2652 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 2653 strlcat(buf, buf2, sizeof(buf)); 2654 } 2655 printf(" flags (%s)\n", buf + 1); 2656 if (mtx_owned(VI_MTX(vp))) 2657 printf(" VI_LOCKed"); 2658 if (vp->v_object != NULL) 2659 printf(" v_object %p ref %d pages %d\n", 2660 vp->v_object, vp->v_object->ref_count, 2661 vp->v_object->resident_page_count); 2662 printf(" "); 2663 lockmgr_printinfo(vp->v_vnlock); 2664 printf("\n"); 2665 if (vp->v_data != NULL) 2666 VOP_PRINT(vp); 2667 } 2668 2669 #ifdef DDB 2670 /* 2671 * List all of the locked vnodes in the system. 2672 * Called when debugging the kernel. 2673 */ 2674 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2675 { 2676 struct mount *mp, *nmp; 2677 struct vnode *vp; 2678 2679 /* 2680 * Note: because this is DDB, we can't obey the locking semantics 2681 * for these structures, which means we could catch an inconsistent 2682 * state and dereference a nasty pointer. Not much to be done 2683 * about that. 2684 */ 2685 db_printf("Locked vnodes\n"); 2686 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2687 nmp = TAILQ_NEXT(mp, mnt_list); 2688 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2689 if (vp->v_type != VMARKER && 2690 VOP_ISLOCKED(vp)) 2691 vprint("", vp); 2692 } 2693 nmp = TAILQ_NEXT(mp, mnt_list); 2694 } 2695 } 2696 2697 /* 2698 * Show details about the given vnode. 2699 */ 2700 DB_SHOW_COMMAND(vnode, db_show_vnode) 2701 { 2702 struct vnode *vp; 2703 2704 if (!have_addr) 2705 return; 2706 vp = (struct vnode *)addr; 2707 vn_printf(vp, "vnode "); 2708 } 2709 #endif /* DDB */ 2710 2711 /* 2712 * Fill in a struct xvfsconf based on a struct vfsconf. 2713 */ 2714 static void 2715 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2716 { 2717 2718 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2719 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2720 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2721 xvfsp->vfc_flags = vfsp->vfc_flags; 2722 /* 2723 * These are unused in userland, we keep them 2724 * to not break binary compatibility. 2725 */ 2726 xvfsp->vfc_vfsops = NULL; 2727 xvfsp->vfc_next = NULL; 2728 } 2729 2730 /* 2731 * Top level filesystem related information gathering. 2732 */ 2733 static int 2734 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2735 { 2736 struct vfsconf *vfsp; 2737 struct xvfsconf xvfsp; 2738 int error; 2739 2740 error = 0; 2741 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2742 bzero(&xvfsp, sizeof(xvfsp)); 2743 vfsconf2x(vfsp, &xvfsp); 2744 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); 2745 if (error) 2746 break; 2747 } 2748 return (error); 2749 } 2750 2751 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2752 "S,xvfsconf", "List of all configured filesystems"); 2753 2754 #ifndef BURN_BRIDGES 2755 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2756 2757 static int 2758 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2759 { 2760 int *name = (int *)arg1 - 1; /* XXX */ 2761 u_int namelen = arg2 + 1; /* XXX */ 2762 struct vfsconf *vfsp; 2763 struct xvfsconf xvfsp; 2764 2765 printf("WARNING: userland calling deprecated sysctl, " 2766 "please rebuild world\n"); 2767 2768 #if 1 || defined(COMPAT_PRELITE2) 2769 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2770 if (namelen == 1) 2771 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2772 #endif 2773 2774 switch (name[1]) { 2775 case VFS_MAXTYPENUM: 2776 if (namelen != 2) 2777 return (ENOTDIR); 2778 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2779 case VFS_CONF: 2780 if (namelen != 3) 2781 return (ENOTDIR); /* overloaded */ 2782 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 2783 if (vfsp->vfc_typenum == name[2]) 2784 break; 2785 if (vfsp == NULL) 2786 return (EOPNOTSUPP); 2787 bzero(&xvfsp, sizeof(xvfsp)); 2788 vfsconf2x(vfsp, &xvfsp); 2789 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2790 } 2791 return (EOPNOTSUPP); 2792 } 2793 2794 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, 2795 vfs_sysctl, "Generic filesystem"); 2796 2797 #if 1 || defined(COMPAT_PRELITE2) 2798 2799 static int 2800 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2801 { 2802 int error; 2803 struct vfsconf *vfsp; 2804 struct ovfsconf ovfs; 2805 2806 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2807 bzero(&ovfs, sizeof(ovfs)); 2808 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2809 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2810 ovfs.vfc_index = vfsp->vfc_typenum; 2811 ovfs.vfc_refcount = vfsp->vfc_refcount; 2812 ovfs.vfc_flags = vfsp->vfc_flags; 2813 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2814 if (error) 2815 return error; 2816 } 2817 return 0; 2818 } 2819 2820 #endif /* 1 || COMPAT_PRELITE2 */ 2821 #endif /* !BURN_BRIDGES */ 2822 2823 #define KINFO_VNODESLOP 10 2824 #ifdef notyet 2825 /* 2826 * Dump vnode list (via sysctl). 2827 */ 2828 /* ARGSUSED */ 2829 static int 2830 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2831 { 2832 struct xvnode *xvn; 2833 struct thread *td = req->td; 2834 struct mount *mp; 2835 struct vnode *vp; 2836 int error, len, n; 2837 2838 /* 2839 * Stale numvnodes access is not fatal here. 2840 */ 2841 req->lock = 0; 2842 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 2843 if (!req->oldptr) 2844 /* Make an estimate */ 2845 return (SYSCTL_OUT(req, 0, len)); 2846 2847 error = sysctl_wire_old_buffer(req, 0); 2848 if (error != 0) 2849 return (error); 2850 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 2851 n = 0; 2852 mtx_lock(&mountlist_mtx); 2853 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2854 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 2855 continue; 2856 MNT_ILOCK(mp); 2857 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2858 if (n == len) 2859 break; 2860 vref(vp); 2861 xvn[n].xv_size = sizeof *xvn; 2862 xvn[n].xv_vnode = vp; 2863 xvn[n].xv_id = 0; /* XXX compat */ 2864 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 2865 XV_COPY(usecount); 2866 XV_COPY(writecount); 2867 XV_COPY(holdcnt); 2868 XV_COPY(mount); 2869 XV_COPY(numoutput); 2870 XV_COPY(type); 2871 #undef XV_COPY 2872 xvn[n].xv_flag = vp->v_vflag; 2873 2874 switch (vp->v_type) { 2875 case VREG: 2876 case VDIR: 2877 case VLNK: 2878 break; 2879 case VBLK: 2880 case VCHR: 2881 if (vp->v_rdev == NULL) { 2882 vrele(vp); 2883 continue; 2884 } 2885 xvn[n].xv_dev = dev2udev(vp->v_rdev); 2886 break; 2887 case VSOCK: 2888 xvn[n].xv_socket = vp->v_socket; 2889 break; 2890 case VFIFO: 2891 xvn[n].xv_fifo = vp->v_fifoinfo; 2892 break; 2893 case VNON: 2894 case VBAD: 2895 default: 2896 /* shouldn't happen? */ 2897 vrele(vp); 2898 continue; 2899 } 2900 vrele(vp); 2901 ++n; 2902 } 2903 MNT_IUNLOCK(mp); 2904 mtx_lock(&mountlist_mtx); 2905 vfs_unbusy(mp, td); 2906 if (n == len) 2907 break; 2908 } 2909 mtx_unlock(&mountlist_mtx); 2910 2911 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 2912 free(xvn, M_TEMP); 2913 return (error); 2914 } 2915 2916 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2917 0, 0, sysctl_vnode, "S,xvnode", ""); 2918 #endif 2919 2920 /* 2921 * Unmount all filesystems. The list is traversed in reverse order 2922 * of mounting to avoid dependencies. 2923 */ 2924 void 2925 vfs_unmountall(void) 2926 { 2927 struct mount *mp; 2928 struct thread *td; 2929 int error; 2930 2931 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread")); 2932 td = curthread; 2933 /* 2934 * Since this only runs when rebooting, it is not interlocked. 2935 */ 2936 while(!TAILQ_EMPTY(&mountlist)) { 2937 mp = TAILQ_LAST(&mountlist, mntlist); 2938 error = dounmount(mp, MNT_FORCE, td); 2939 if (error) { 2940 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2941 /* 2942 * XXX: Due to the way in which we mount the root 2943 * file system off of devfs, devfs will generate a 2944 * "busy" warning when we try to unmount it before 2945 * the root. Don't print a warning as a result in 2946 * order to avoid false positive errors that may 2947 * cause needless upset. 2948 */ 2949 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) { 2950 printf("unmount of %s failed (", 2951 mp->mnt_stat.f_mntonname); 2952 if (error == EBUSY) 2953 printf("BUSY)\n"); 2954 else 2955 printf("%d)\n", error); 2956 } 2957 } else { 2958 /* The unmount has removed mp from the mountlist */ 2959 } 2960 } 2961 } 2962 2963 /* 2964 * perform msync on all vnodes under a mount point 2965 * the mount point must be locked. 2966 */ 2967 void 2968 vfs_msync(struct mount *mp, int flags) 2969 { 2970 struct vnode *vp, *mvp; 2971 struct vm_object *obj; 2972 2973 MNT_ILOCK(mp); 2974 MNT_VNODE_FOREACH(vp, mp, mvp) { 2975 VI_LOCK(vp); 2976 if ((vp->v_iflag & VI_OBJDIRTY) && 2977 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 2978 MNT_IUNLOCK(mp); 2979 if (!vget(vp, 2980 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 2981 curthread)) { 2982 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 2983 vput(vp); 2984 MNT_ILOCK(mp); 2985 continue; 2986 } 2987 2988 obj = vp->v_object; 2989 if (obj != NULL) { 2990 VM_OBJECT_LOCK(obj); 2991 vm_object_page_clean(obj, 0, 0, 2992 flags == MNT_WAIT ? 2993 OBJPC_SYNC : OBJPC_NOSYNC); 2994 VM_OBJECT_UNLOCK(obj); 2995 } 2996 vput(vp); 2997 } 2998 MNT_ILOCK(mp); 2999 } else 3000 VI_UNLOCK(vp); 3001 } 3002 MNT_IUNLOCK(mp); 3003 } 3004 3005 /* 3006 * Mark a vnode as free, putting it up for recycling. 3007 */ 3008 static void 3009 vfree(struct vnode *vp) 3010 { 3011 3012 CTR1(KTR_VFS, "vfree vp %p", vp); 3013 ASSERT_VI_LOCKED(vp, "vfree"); 3014 mtx_lock(&vnode_free_list_mtx); 3015 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed.")); 3016 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free")); 3017 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't")); 3018 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp, 3019 ("vfree: Freeing doomed vnode")); 3020 if (vp->v_iflag & VI_AGE) { 3021 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3022 } else { 3023 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3024 } 3025 freevnodes++; 3026 vp->v_iflag &= ~VI_AGE; 3027 vp->v_iflag |= VI_FREE; 3028 mtx_unlock(&vnode_free_list_mtx); 3029 } 3030 3031 /* 3032 * Opposite of vfree() - mark a vnode as in use. 3033 */ 3034 static void 3035 vbusy(struct vnode *vp) 3036 { 3037 CTR1(KTR_VFS, "vbusy vp %p", vp); 3038 ASSERT_VI_LOCKED(vp, "vbusy"); 3039 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free")); 3040 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed.")); 3041 3042 mtx_lock(&vnode_free_list_mtx); 3043 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3044 freevnodes--; 3045 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3046 mtx_unlock(&vnode_free_list_mtx); 3047 } 3048 3049 /* 3050 * Initalize per-vnode helper structure to hold poll-related state. 3051 */ 3052 void 3053 v_addpollinfo(struct vnode *vp) 3054 { 3055 struct vpollinfo *vi; 3056 3057 vi = uma_zalloc(vnodepoll_zone, M_WAITOK); 3058 if (vp->v_pollinfo != NULL) { 3059 uma_zfree(vnodepoll_zone, vi); 3060 return; 3061 } 3062 vp->v_pollinfo = vi; 3063 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3064 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock, 3065 vfs_knlunlock, vfs_knllocked); 3066 } 3067 3068 /* 3069 * Record a process's interest in events which might happen to 3070 * a vnode. Because poll uses the historic select-style interface 3071 * internally, this routine serves as both the ``check for any 3072 * pending events'' and the ``record my interest in future events'' 3073 * functions. (These are done together, while the lock is held, 3074 * to avoid race conditions.) 3075 */ 3076 int 3077 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 3078 { 3079 3080 if (vp->v_pollinfo == NULL) 3081 v_addpollinfo(vp); 3082 mtx_lock(&vp->v_pollinfo->vpi_lock); 3083 if (vp->v_pollinfo->vpi_revents & events) { 3084 /* 3085 * This leaves events we are not interested 3086 * in available for the other process which 3087 * which presumably had requested them 3088 * (otherwise they would never have been 3089 * recorded). 3090 */ 3091 events &= vp->v_pollinfo->vpi_revents; 3092 vp->v_pollinfo->vpi_revents &= ~events; 3093 3094 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3095 return events; 3096 } 3097 vp->v_pollinfo->vpi_events |= events; 3098 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3099 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3100 return 0; 3101 } 3102 3103 /* 3104 * Routine to create and manage a filesystem syncer vnode. 3105 */ 3106 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3107 static int sync_fsync(struct vop_fsync_args *); 3108 static int sync_inactive(struct vop_inactive_args *); 3109 static int sync_reclaim(struct vop_reclaim_args *); 3110 3111 static struct vop_vector sync_vnodeops = { 3112 .vop_bypass = VOP_EOPNOTSUPP, 3113 .vop_close = sync_close, /* close */ 3114 .vop_fsync = sync_fsync, /* fsync */ 3115 .vop_inactive = sync_inactive, /* inactive */ 3116 .vop_reclaim = sync_reclaim, /* reclaim */ 3117 .vop_lock1 = vop_stdlock, /* lock */ 3118 .vop_unlock = vop_stdunlock, /* unlock */ 3119 .vop_islocked = vop_stdislocked, /* islocked */ 3120 }; 3121 3122 /* 3123 * Create a new filesystem syncer vnode for the specified mount point. 3124 */ 3125 int 3126 vfs_allocate_syncvnode(struct mount *mp) 3127 { 3128 struct vnode *vp; 3129 static long start, incr, next; 3130 int error; 3131 3132 /* Allocate a new vnode */ 3133 if ((error = getnewvnode("syncer", mp, &sync_vnodeops, &vp)) != 0) { 3134 mp->mnt_syncer = NULL; 3135 return (error); 3136 } 3137 vp->v_type = VNON; 3138 error = insmntque(vp, mp); 3139 if (error != 0) 3140 panic("vfs_allocate_syncvnode: insmntque failed"); 3141 /* 3142 * Place the vnode onto the syncer worklist. We attempt to 3143 * scatter them about on the list so that they will go off 3144 * at evenly distributed times even if all the filesystems 3145 * are mounted at once. 3146 */ 3147 next += incr; 3148 if (next == 0 || next > syncer_maxdelay) { 3149 start /= 2; 3150 incr /= 2; 3151 if (start == 0) { 3152 start = syncer_maxdelay / 2; 3153 incr = syncer_maxdelay; 3154 } 3155 next = start; 3156 } 3157 VI_LOCK(vp); 3158 vn_syncer_add_to_worklist(&vp->v_bufobj, 3159 syncdelay > 0 ? next % syncdelay : 0); 3160 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 3161 mtx_lock(&sync_mtx); 3162 sync_vnode_count++; 3163 mtx_unlock(&sync_mtx); 3164 VI_UNLOCK(vp); 3165 mp->mnt_syncer = vp; 3166 return (0); 3167 } 3168 3169 /* 3170 * Do a lazy sync of the filesystem. 3171 */ 3172 static int 3173 sync_fsync(struct vop_fsync_args *ap) 3174 { 3175 struct vnode *syncvp = ap->a_vp; 3176 struct mount *mp = syncvp->v_mount; 3177 struct thread *td = ap->a_td; 3178 int error; 3179 struct bufobj *bo; 3180 3181 /* 3182 * We only need to do something if this is a lazy evaluation. 3183 */ 3184 if (ap->a_waitfor != MNT_LAZY) 3185 return (0); 3186 3187 /* 3188 * Move ourselves to the back of the sync list. 3189 */ 3190 bo = &syncvp->v_bufobj; 3191 BO_LOCK(bo); 3192 vn_syncer_add_to_worklist(bo, syncdelay); 3193 BO_UNLOCK(bo); 3194 3195 /* 3196 * Walk the list of vnodes pushing all that are dirty and 3197 * not already on the sync list. 3198 */ 3199 mtx_lock(&mountlist_mtx); 3200 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3201 mtx_unlock(&mountlist_mtx); 3202 return (0); 3203 } 3204 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3205 vfs_unbusy(mp, td); 3206 return (0); 3207 } 3208 MNT_ILOCK(mp); 3209 mp->mnt_noasync++; 3210 mp->mnt_kern_flag &= ~MNTK_ASYNC; 3211 MNT_IUNLOCK(mp); 3212 vfs_msync(mp, MNT_NOWAIT); 3213 error = VFS_SYNC(mp, MNT_LAZY, td); 3214 MNT_ILOCK(mp); 3215 mp->mnt_noasync--; 3216 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 3217 mp->mnt_kern_flag |= MNTK_ASYNC; 3218 MNT_IUNLOCK(mp); 3219 vn_finished_write(mp); 3220 vfs_unbusy(mp, td); 3221 return (error); 3222 } 3223 3224 /* 3225 * The syncer vnode is no referenced. 3226 */ 3227 static int 3228 sync_inactive(struct vop_inactive_args *ap) 3229 { 3230 3231 vgone(ap->a_vp); 3232 return (0); 3233 } 3234 3235 /* 3236 * The syncer vnode is no longer needed and is being decommissioned. 3237 * 3238 * Modifications to the worklist must be protected by sync_mtx. 3239 */ 3240 static int 3241 sync_reclaim(struct vop_reclaim_args *ap) 3242 { 3243 struct vnode *vp = ap->a_vp; 3244 struct bufobj *bo; 3245 3246 VI_LOCK(vp); 3247 bo = &vp->v_bufobj; 3248 vp->v_mount->mnt_syncer = NULL; 3249 if (bo->bo_flag & BO_ONWORKLST) { 3250 mtx_lock(&sync_mtx); 3251 LIST_REMOVE(bo, bo_synclist); 3252 syncer_worklist_len--; 3253 sync_vnode_count--; 3254 mtx_unlock(&sync_mtx); 3255 bo->bo_flag &= ~BO_ONWORKLST; 3256 } 3257 VI_UNLOCK(vp); 3258 3259 return (0); 3260 } 3261 3262 /* 3263 * Check if vnode represents a disk device 3264 */ 3265 int 3266 vn_isdisk(struct vnode *vp, int *errp) 3267 { 3268 int error; 3269 3270 error = 0; 3271 dev_lock(); 3272 if (vp->v_type != VCHR) 3273 error = ENOTBLK; 3274 else if (vp->v_rdev == NULL) 3275 error = ENXIO; 3276 else if (vp->v_rdev->si_devsw == NULL) 3277 error = ENXIO; 3278 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 3279 error = ENOTBLK; 3280 dev_unlock(); 3281 if (errp != NULL) 3282 *errp = error; 3283 return (error == 0); 3284 } 3285 3286 /* 3287 * Common filesystem object access control check routine. Accepts a 3288 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3289 * and optional call-by-reference privused argument allowing vaccess() 3290 * to indicate to the caller whether privilege was used to satisfy the 3291 * request (obsoleted). Returns 0 on success, or an errno on failure. 3292 * 3293 * The ifdef'd CAPABILITIES version is here for reference, but is not 3294 * actually used. 3295 */ 3296 int 3297 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 3298 mode_t acc_mode, struct ucred *cred, int *privused) 3299 { 3300 mode_t dac_granted; 3301 mode_t priv_granted; 3302 3303 /* 3304 * Look for a normal, non-privileged way to access the file/directory 3305 * as requested. If it exists, go with that. 3306 */ 3307 3308 if (privused != NULL) 3309 *privused = 0; 3310 3311 dac_granted = 0; 3312 3313 /* Check the owner. */ 3314 if (cred->cr_uid == file_uid) { 3315 dac_granted |= VADMIN; 3316 if (file_mode & S_IXUSR) 3317 dac_granted |= VEXEC; 3318 if (file_mode & S_IRUSR) 3319 dac_granted |= VREAD; 3320 if (file_mode & S_IWUSR) 3321 dac_granted |= (VWRITE | VAPPEND); 3322 3323 if ((acc_mode & dac_granted) == acc_mode) 3324 return (0); 3325 3326 goto privcheck; 3327 } 3328 3329 /* Otherwise, check the groups (first match) */ 3330 if (groupmember(file_gid, cred)) { 3331 if (file_mode & S_IXGRP) 3332 dac_granted |= VEXEC; 3333 if (file_mode & S_IRGRP) 3334 dac_granted |= VREAD; 3335 if (file_mode & S_IWGRP) 3336 dac_granted |= (VWRITE | VAPPEND); 3337 3338 if ((acc_mode & dac_granted) == acc_mode) 3339 return (0); 3340 3341 goto privcheck; 3342 } 3343 3344 /* Otherwise, check everyone else. */ 3345 if (file_mode & S_IXOTH) 3346 dac_granted |= VEXEC; 3347 if (file_mode & S_IROTH) 3348 dac_granted |= VREAD; 3349 if (file_mode & S_IWOTH) 3350 dac_granted |= (VWRITE | VAPPEND); 3351 if ((acc_mode & dac_granted) == acc_mode) 3352 return (0); 3353 3354 privcheck: 3355 /* 3356 * Build a privilege mask to determine if the set of privileges 3357 * satisfies the requirements when combined with the granted mask 3358 * from above. For each privilege, if the privilege is required, 3359 * bitwise or the request type onto the priv_granted mask. 3360 */ 3361 priv_granted = 0; 3362 3363 if (type == VDIR) { 3364 /* 3365 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 3366 * requests, instead of PRIV_VFS_EXEC. 3367 */ 3368 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3369 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 3370 priv_granted |= VEXEC; 3371 } else { 3372 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3373 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 3374 priv_granted |= VEXEC; 3375 } 3376 3377 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3378 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 3379 priv_granted |= VREAD; 3380 3381 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3382 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 3383 priv_granted |= (VWRITE | VAPPEND); 3384 3385 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3386 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 3387 priv_granted |= VADMIN; 3388 3389 if ((acc_mode & (priv_granted | dac_granted)) == acc_mode) { 3390 /* XXX audit: privilege used */ 3391 if (privused != NULL) 3392 *privused = 1; 3393 return (0); 3394 } 3395 3396 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3397 } 3398 3399 /* 3400 * Credential check based on process requesting service, and per-attribute 3401 * permissions. 3402 */ 3403 int 3404 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 3405 struct thread *td, int access) 3406 { 3407 3408 /* 3409 * Kernel-invoked always succeeds. 3410 */ 3411 if (cred == NOCRED) 3412 return (0); 3413 3414 /* 3415 * Do not allow privileged processes in jail to directly manipulate 3416 * system attributes. 3417 */ 3418 switch (attrnamespace) { 3419 case EXTATTR_NAMESPACE_SYSTEM: 3420 /* Potentially should be: return (EPERM); */ 3421 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 3422 case EXTATTR_NAMESPACE_USER: 3423 return (VOP_ACCESS(vp, access, cred, td)); 3424 default: 3425 return (EPERM); 3426 } 3427 } 3428 3429 #ifdef DEBUG_VFS_LOCKS 3430 /* 3431 * This only exists to supress warnings from unlocked specfs accesses. It is 3432 * no longer ok to have an unlocked VFS. 3433 */ 3434 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 3435 3436 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3437 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, ""); 3438 3439 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3440 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, ""); 3441 3442 int vfs_badlock_print = 1; /* Print lock violations. */ 3443 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, ""); 3444 3445 #ifdef KDB 3446 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 3447 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, ""); 3448 #endif 3449 3450 static void 3451 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3452 { 3453 3454 #ifdef KDB 3455 if (vfs_badlock_backtrace) 3456 kdb_backtrace(); 3457 #endif 3458 if (vfs_badlock_print) 3459 printf("%s: %p %s\n", str, (void *)vp, msg); 3460 if (vfs_badlock_ddb) 3461 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 3462 } 3463 3464 void 3465 assert_vi_locked(struct vnode *vp, const char *str) 3466 { 3467 3468 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3469 vfs_badlock("interlock is not locked but should be", str, vp); 3470 } 3471 3472 void 3473 assert_vi_unlocked(struct vnode *vp, const char *str) 3474 { 3475 3476 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3477 vfs_badlock("interlock is locked but should not be", str, vp); 3478 } 3479 3480 void 3481 assert_vop_locked(struct vnode *vp, const char *str) 3482 { 3483 3484 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == 0) 3485 vfs_badlock("is not locked but should be", str, vp); 3486 } 3487 3488 void 3489 assert_vop_unlocked(struct vnode *vp, const char *str) 3490 { 3491 3492 if (vp && !IGNORE_LOCK(vp) && 3493 VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 3494 vfs_badlock("is locked but should not be", str, vp); 3495 } 3496 3497 void 3498 assert_vop_elocked(struct vnode *vp, const char *str) 3499 { 3500 3501 if (vp && !IGNORE_LOCK(vp) && 3502 VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 3503 vfs_badlock("is not exclusive locked but should be", str, vp); 3504 } 3505 3506 #if 0 3507 void 3508 assert_vop_elocked_other(struct vnode *vp, const char *str) 3509 { 3510 3511 if (vp && !IGNORE_LOCK(vp) && 3512 VOP_ISLOCKED(vp) != LK_EXCLOTHER) 3513 vfs_badlock("is not exclusive locked by another thread", 3514 str, vp); 3515 } 3516 3517 void 3518 assert_vop_slocked(struct vnode *vp, const char *str) 3519 { 3520 3521 if (vp && !IGNORE_LOCK(vp) && 3522 VOP_ISLOCKED(vp) != LK_SHARED) 3523 vfs_badlock("is not locked shared but should be", str, vp); 3524 } 3525 #endif /* 0 */ 3526 #endif /* DEBUG_VFS_LOCKS */ 3527 3528 void 3529 vop_rename_pre(void *ap) 3530 { 3531 struct vop_rename_args *a = ap; 3532 3533 #ifdef DEBUG_VFS_LOCKS 3534 if (a->a_tvp) 3535 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3536 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3537 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3538 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3539 3540 /* Check the source (from). */ 3541 if (a->a_tdvp != a->a_fdvp && a->a_tvp != a->a_fdvp) 3542 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3543 if (a->a_tvp != a->a_fvp) 3544 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 3545 3546 /* Check the target. */ 3547 if (a->a_tvp) 3548 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3549 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3550 #endif 3551 if (a->a_tdvp != a->a_fdvp) 3552 vhold(a->a_fdvp); 3553 if (a->a_tvp != a->a_fvp) 3554 vhold(a->a_fvp); 3555 vhold(a->a_tdvp); 3556 if (a->a_tvp) 3557 vhold(a->a_tvp); 3558 } 3559 3560 void 3561 vop_strategy_pre(void *ap) 3562 { 3563 #ifdef DEBUG_VFS_LOCKS 3564 struct vop_strategy_args *a; 3565 struct buf *bp; 3566 3567 a = ap; 3568 bp = a->a_bp; 3569 3570 /* 3571 * Cluster ops lock their component buffers but not the IO container. 3572 */ 3573 if ((bp->b_flags & B_CLUSTER) != 0) 3574 return; 3575 3576 if (!BUF_ISLOCKED(bp)) { 3577 if (vfs_badlock_print) 3578 printf( 3579 "VOP_STRATEGY: bp is not locked but should be\n"); 3580 if (vfs_badlock_ddb) 3581 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 3582 } 3583 #endif 3584 } 3585 3586 void 3587 vop_lookup_pre(void *ap) 3588 { 3589 #ifdef DEBUG_VFS_LOCKS 3590 struct vop_lookup_args *a; 3591 struct vnode *dvp; 3592 3593 a = ap; 3594 dvp = a->a_dvp; 3595 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3596 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3597 #endif 3598 } 3599 3600 void 3601 vop_lookup_post(void *ap, int rc) 3602 { 3603 #ifdef DEBUG_VFS_LOCKS 3604 struct vop_lookup_args *a; 3605 struct vnode *dvp; 3606 struct vnode *vp; 3607 3608 a = ap; 3609 dvp = a->a_dvp; 3610 vp = *(a->a_vpp); 3611 3612 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3613 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3614 3615 if (!rc) 3616 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)"); 3617 #endif 3618 } 3619 3620 void 3621 vop_lock_pre(void *ap) 3622 { 3623 #ifdef DEBUG_VFS_LOCKS 3624 struct vop_lock1_args *a = ap; 3625 3626 if ((a->a_flags & LK_INTERLOCK) == 0) 3627 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3628 else 3629 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3630 #endif 3631 } 3632 3633 void 3634 vop_lock_post(void *ap, int rc) 3635 { 3636 #ifdef DEBUG_VFS_LOCKS 3637 struct vop_lock1_args *a = ap; 3638 3639 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3640 if (rc == 0) 3641 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3642 #endif 3643 } 3644 3645 void 3646 vop_unlock_pre(void *ap) 3647 { 3648 #ifdef DEBUG_VFS_LOCKS 3649 struct vop_unlock_args *a = ap; 3650 3651 if (a->a_flags & LK_INTERLOCK) 3652 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 3653 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 3654 #endif 3655 } 3656 3657 void 3658 vop_unlock_post(void *ap, int rc) 3659 { 3660 #ifdef DEBUG_VFS_LOCKS 3661 struct vop_unlock_args *a = ap; 3662 3663 if (a->a_flags & LK_INTERLOCK) 3664 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 3665 #endif 3666 } 3667 3668 void 3669 vop_create_post(void *ap, int rc) 3670 { 3671 struct vop_create_args *a = ap; 3672 3673 if (!rc) 3674 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3675 } 3676 3677 void 3678 vop_link_post(void *ap, int rc) 3679 { 3680 struct vop_link_args *a = ap; 3681 3682 if (!rc) { 3683 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 3684 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 3685 } 3686 } 3687 3688 void 3689 vop_mkdir_post(void *ap, int rc) 3690 { 3691 struct vop_mkdir_args *a = ap; 3692 3693 if (!rc) 3694 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 3695 } 3696 3697 void 3698 vop_mknod_post(void *ap, int rc) 3699 { 3700 struct vop_mknod_args *a = ap; 3701 3702 if (!rc) 3703 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3704 } 3705 3706 void 3707 vop_remove_post(void *ap, int rc) 3708 { 3709 struct vop_remove_args *a = ap; 3710 3711 if (!rc) { 3712 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3713 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 3714 } 3715 } 3716 3717 void 3718 vop_rename_post(void *ap, int rc) 3719 { 3720 struct vop_rename_args *a = ap; 3721 3722 if (!rc) { 3723 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE); 3724 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE); 3725 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 3726 if (a->a_tvp) 3727 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 3728 } 3729 if (a->a_tdvp != a->a_fdvp) 3730 vdrop(a->a_fdvp); 3731 if (a->a_tvp != a->a_fvp) 3732 vdrop(a->a_fvp); 3733 vdrop(a->a_tdvp); 3734 if (a->a_tvp) 3735 vdrop(a->a_tvp); 3736 } 3737 3738 void 3739 vop_rmdir_post(void *ap, int rc) 3740 { 3741 struct vop_rmdir_args *a = ap; 3742 3743 if (!rc) { 3744 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 3745 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 3746 } 3747 } 3748 3749 void 3750 vop_setattr_post(void *ap, int rc) 3751 { 3752 struct vop_setattr_args *a = ap; 3753 3754 if (!rc) 3755 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 3756 } 3757 3758 void 3759 vop_symlink_post(void *ap, int rc) 3760 { 3761 struct vop_symlink_args *a = ap; 3762 3763 if (!rc) 3764 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3765 } 3766 3767 static struct knlist fs_knlist; 3768 3769 static void 3770 vfs_event_init(void *arg) 3771 { 3772 knlist_init(&fs_knlist, NULL, NULL, NULL, NULL); 3773 } 3774 /* XXX - correct order? */ 3775 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 3776 3777 void 3778 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused) 3779 { 3780 3781 KNOTE_UNLOCKED(&fs_knlist, event); 3782 } 3783 3784 static int filt_fsattach(struct knote *kn); 3785 static void filt_fsdetach(struct knote *kn); 3786 static int filt_fsevent(struct knote *kn, long hint); 3787 3788 struct filterops fs_filtops = 3789 { 0, filt_fsattach, filt_fsdetach, filt_fsevent }; 3790 3791 static int 3792 filt_fsattach(struct knote *kn) 3793 { 3794 3795 kn->kn_flags |= EV_CLEAR; 3796 knlist_add(&fs_knlist, kn, 0); 3797 return (0); 3798 } 3799 3800 static void 3801 filt_fsdetach(struct knote *kn) 3802 { 3803 3804 knlist_remove(&fs_knlist, kn, 0); 3805 } 3806 3807 static int 3808 filt_fsevent(struct knote *kn, long hint) 3809 { 3810 3811 kn->kn_fflags |= hint; 3812 return (kn->kn_fflags != 0); 3813 } 3814 3815 static int 3816 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 3817 { 3818 struct vfsidctl vc; 3819 int error; 3820 struct mount *mp; 3821 3822 error = SYSCTL_IN(req, &vc, sizeof(vc)); 3823 if (error) 3824 return (error); 3825 if (vc.vc_vers != VFS_CTL_VERS1) 3826 return (EINVAL); 3827 mp = vfs_getvfs(&vc.vc_fsid); 3828 if (mp == NULL) 3829 return (ENOENT); 3830 /* ensure that a specific sysctl goes to the right filesystem. */ 3831 if (strcmp(vc.vc_fstypename, "*") != 0 && 3832 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 3833 vfs_rel(mp); 3834 return (EINVAL); 3835 } 3836 VCTLTOREQ(&vc, req); 3837 error = VFS_SYSCTL(mp, vc.vc_op, req); 3838 vfs_rel(mp); 3839 return (error); 3840 } 3841 3842 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, NULL, 0, sysctl_vfs_ctl, "", 3843 "Sysctl by fsid"); 3844 3845 /* 3846 * Function to initialize a va_filerev field sensibly. 3847 * XXX: Wouldn't a random number make a lot more sense ?? 3848 */ 3849 u_quad_t 3850 init_va_filerev(void) 3851 { 3852 struct bintime bt; 3853 3854 getbinuptime(&bt); 3855 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 3856 } 3857 3858 static int filt_vfsread(struct knote *kn, long hint); 3859 static int filt_vfswrite(struct knote *kn, long hint); 3860 static int filt_vfsvnode(struct knote *kn, long hint); 3861 static void filt_vfsdetach(struct knote *kn); 3862 static struct filterops vfsread_filtops = 3863 { 1, NULL, filt_vfsdetach, filt_vfsread }; 3864 static struct filterops vfswrite_filtops = 3865 { 1, NULL, filt_vfsdetach, filt_vfswrite }; 3866 static struct filterops vfsvnode_filtops = 3867 { 1, NULL, filt_vfsdetach, filt_vfsvnode }; 3868 3869 static void 3870 vfs_knllock(void *arg) 3871 { 3872 struct vnode *vp = arg; 3873 3874 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3875 } 3876 3877 static void 3878 vfs_knlunlock(void *arg) 3879 { 3880 struct vnode *vp = arg; 3881 3882 VOP_UNLOCK(vp, 0); 3883 } 3884 3885 static int 3886 vfs_knllocked(void *arg) 3887 { 3888 struct vnode *vp = arg; 3889 3890 return (VOP_ISLOCKED(vp) == LK_EXCLUSIVE); 3891 } 3892 3893 int 3894 vfs_kqfilter(struct vop_kqfilter_args *ap) 3895 { 3896 struct vnode *vp = ap->a_vp; 3897 struct knote *kn = ap->a_kn; 3898 struct knlist *knl; 3899 3900 switch (kn->kn_filter) { 3901 case EVFILT_READ: 3902 kn->kn_fop = &vfsread_filtops; 3903 break; 3904 case EVFILT_WRITE: 3905 kn->kn_fop = &vfswrite_filtops; 3906 break; 3907 case EVFILT_VNODE: 3908 kn->kn_fop = &vfsvnode_filtops; 3909 break; 3910 default: 3911 return (EINVAL); 3912 } 3913 3914 kn->kn_hook = (caddr_t)vp; 3915 3916 if (vp->v_pollinfo == NULL) 3917 v_addpollinfo(vp); 3918 if (vp->v_pollinfo == NULL) 3919 return (ENOMEM); 3920 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 3921 knlist_add(knl, kn, 0); 3922 3923 return (0); 3924 } 3925 3926 /* 3927 * Detach knote from vnode 3928 */ 3929 static void 3930 filt_vfsdetach(struct knote *kn) 3931 { 3932 struct vnode *vp = (struct vnode *)kn->kn_hook; 3933 3934 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 3935 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 3936 } 3937 3938 /*ARGSUSED*/ 3939 static int 3940 filt_vfsread(struct knote *kn, long hint) 3941 { 3942 struct vnode *vp = (struct vnode *)kn->kn_hook; 3943 struct vattr va; 3944 3945 /* 3946 * filesystem is gone, so set the EOF flag and schedule 3947 * the knote for deletion. 3948 */ 3949 if (hint == NOTE_REVOKE) { 3950 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 3951 return (1); 3952 } 3953 3954 if (VOP_GETATTR(vp, &va, curthread->td_ucred, curthread)) 3955 return (0); 3956 3957 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 3958 return (kn->kn_data != 0); 3959 } 3960 3961 /*ARGSUSED*/ 3962 static int 3963 filt_vfswrite(struct knote *kn, long hint) 3964 { 3965 /* 3966 * filesystem is gone, so set the EOF flag and schedule 3967 * the knote for deletion. 3968 */ 3969 if (hint == NOTE_REVOKE) 3970 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 3971 3972 kn->kn_data = 0; 3973 return (1); 3974 } 3975 3976 static int 3977 filt_vfsvnode(struct knote *kn, long hint) 3978 { 3979 if (kn->kn_sfflags & hint) 3980 kn->kn_fflags |= hint; 3981 if (hint == NOTE_REVOKE) { 3982 kn->kn_flags |= EV_EOF; 3983 return (1); 3984 } 3985 return (kn->kn_fflags != 0); 3986 } 3987 3988 int 3989 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 3990 { 3991 int error; 3992 3993 if (dp->d_reclen > ap->a_uio->uio_resid) 3994 return (ENAMETOOLONG); 3995 error = uiomove(dp, dp->d_reclen, ap->a_uio); 3996 if (error) { 3997 if (ap->a_ncookies != NULL) { 3998 if (ap->a_cookies != NULL) 3999 free(ap->a_cookies, M_TEMP); 4000 ap->a_cookies = NULL; 4001 *ap->a_ncookies = 0; 4002 } 4003 return (error); 4004 } 4005 if (ap->a_ncookies == NULL) 4006 return (0); 4007 4008 KASSERT(ap->a_cookies, 4009 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 4010 4011 *ap->a_cookies = realloc(*ap->a_cookies, 4012 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 4013 (*ap->a_cookies)[*ap->a_ncookies] = off; 4014 return (0); 4015 } 4016 4017 /* 4018 * Mark for update the access time of the file if the filesystem 4019 * supports VA_MARK_ATIME. This functionality is used by execve 4020 * and mmap, so we want to avoid the synchronous I/O implied by 4021 * directly setting va_atime for the sake of efficiency. 4022 */ 4023 void 4024 vfs_mark_atime(struct vnode *vp, struct thread *td) 4025 { 4026 struct vattr atimeattr; 4027 4028 if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) { 4029 VATTR_NULL(&atimeattr); 4030 atimeattr.va_vaflags |= VA_MARK_ATIME; 4031 (void)VOP_SETATTR(vp, &atimeattr, td->td_ucred, td); 4032 } 4033 } 4034