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