1 /*- 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 35 */ 36 37 /* 38 * External virtual filesystem routines 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_ddb.h" 45 #include "opt_mac.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/conf.h> 52 #include <sys/dirent.h> 53 #include <sys/event.h> 54 #include <sys/eventhandler.h> 55 #include <sys/extattr.h> 56 #include <sys/file.h> 57 #include <sys/fcntl.h> 58 #include <sys/jail.h> 59 #include <sys/kdb.h> 60 #include <sys/kernel.h> 61 #include <sys/kthread.h> 62 #include <sys/malloc.h> 63 #include <sys/mount.h> 64 #include <sys/namei.h> 65 #include <sys/priv.h> 66 #include <sys/reboot.h> 67 #include <sys/sleepqueue.h> 68 #include <sys/stat.h> 69 #include <sys/sysctl.h> 70 #include <sys/syslog.h> 71 #include <sys/vmmeter.h> 72 #include <sys/vnode.h> 73 74 #include <machine/stdarg.h> 75 76 #include <security/mac/mac_framework.h> 77 78 #include <vm/vm.h> 79 #include <vm/vm_object.h> 80 #include <vm/vm_extern.h> 81 #include <vm/pmap.h> 82 #include <vm/vm_map.h> 83 #include <vm/vm_page.h> 84 #include <vm/vm_kern.h> 85 #include <vm/uma.h> 86 87 #ifdef DDB 88 #include <ddb/ddb.h> 89 #endif 90 91 static MALLOC_DEFINE(M_NETADDR, "subr_export_host", "Export host address structure"); 92 93 static void delmntque(struct vnode *vp); 94 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 95 int slpflag, int slptimeo); 96 static void syncer_shutdown(void *arg, int howto); 97 static int vtryrecycle(struct vnode *vp); 98 static void vbusy(struct vnode *vp); 99 static void vinactive(struct vnode *, struct thread *); 100 static void v_incr_usecount(struct vnode *); 101 static void v_decr_usecount(struct vnode *); 102 static void v_decr_useonly(struct vnode *); 103 static void v_upgrade_usecount(struct vnode *); 104 static void vfree(struct vnode *); 105 static void vnlru_free(int); 106 static void vdestroy(struct vnode *); 107 static void vgonel(struct vnode *); 108 static void vfs_knllock(void *arg); 109 static void vfs_knlunlock(void *arg); 110 static int vfs_knllocked(void *arg); 111 112 113 /* 114 * Enable Giant pushdown based on whether or not the vm is mpsafe in this 115 * build. Without mpsafevm the buffer cache can not run Giant free. 116 */ 117 int mpsafe_vfs = 1; 118 TUNABLE_INT("debug.mpsafevfs", &mpsafe_vfs); 119 SYSCTL_INT(_debug, OID_AUTO, mpsafevfs, CTLFLAG_RD, &mpsafe_vfs, 0, 120 "MPSAFE VFS"); 121 122 /* 123 * Number of vnodes in existence. Increased whenever getnewvnode() 124 * allocates a new vnode, decreased on vdestroy() called on VI_DOOMed 125 * vnode. 126 */ 127 static unsigned long numvnodes; 128 129 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 130 131 /* 132 * Conversion tables for conversion from vnode types to inode formats 133 * and back. 134 */ 135 enum vtype iftovt_tab[16] = { 136 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 137 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 138 }; 139 int vttoif_tab[10] = { 140 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 141 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 142 }; 143 144 /* 145 * List of vnodes that are ready for recycling. 146 */ 147 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 148 149 /* 150 * Free vnode target. Free vnodes may simply be files which have been stat'd 151 * but not read. This is somewhat common, and a small cache of such files 152 * should be kept to avoid recreation costs. 153 */ 154 static u_long wantfreevnodes; 155 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 156 /* Number of vnodes in the free list. */ 157 static u_long freevnodes; 158 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 159 160 /* 161 * Various variables used for debugging the new implementation of 162 * reassignbuf(). 163 * XXX these are probably of (very) limited utility now. 164 */ 165 static int reassignbufcalls; 166 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 167 168 /* 169 * Cache for the mount type id assigned to NFS. This is used for 170 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 171 */ 172 int nfs_mount_type = -1; 173 174 /* To keep more than one thread at a time from running vfs_getnewfsid */ 175 static struct mtx mntid_mtx; 176 177 /* 178 * Lock for any access to the following: 179 * vnode_free_list 180 * numvnodes 181 * freevnodes 182 */ 183 static struct mtx vnode_free_list_mtx; 184 185 /* Publicly exported FS */ 186 struct nfs_public nfs_pub; 187 188 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 189 static uma_zone_t vnode_zone; 190 static uma_zone_t vnodepoll_zone; 191 192 /* Set to 1 to print out reclaim of active vnodes */ 193 int prtactive; 194 195 /* 196 * The workitem queue. 197 * 198 * It is useful to delay writes of file data and filesystem metadata 199 * for tens of seconds so that quickly created and deleted files need 200 * not waste disk bandwidth being created and removed. To realize this, 201 * we append vnodes to a "workitem" queue. When running with a soft 202 * updates implementation, most pending metadata dependencies should 203 * not wait for more than a few seconds. Thus, mounted on block devices 204 * are delayed only about a half the time that file data is delayed. 205 * Similarly, directory updates are more critical, so are only delayed 206 * about a third the time that file data is delayed. Thus, there are 207 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 208 * one each second (driven off the filesystem syncer process). The 209 * syncer_delayno variable indicates the next queue that is to be processed. 210 * Items that need to be processed soon are placed in this queue: 211 * 212 * syncer_workitem_pending[syncer_delayno] 213 * 214 * A delay of fifteen seconds is done by placing the request fifteen 215 * entries later in the queue: 216 * 217 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 218 * 219 */ 220 static int syncer_delayno; 221 static long syncer_mask; 222 LIST_HEAD(synclist, bufobj); 223 static struct synclist *syncer_workitem_pending; 224 /* 225 * The sync_mtx protects: 226 * bo->bo_synclist 227 * sync_vnode_count 228 * syncer_delayno 229 * syncer_state 230 * syncer_workitem_pending 231 * syncer_worklist_len 232 * rushjob 233 */ 234 static struct mtx sync_mtx; 235 236 #define SYNCER_MAXDELAY 32 237 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 238 static int syncdelay = 30; /* max time to delay syncing data */ 239 static int filedelay = 30; /* time to delay syncing files */ 240 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 241 static int dirdelay = 29; /* time to delay syncing directories */ 242 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 243 static int metadelay = 28; /* time to delay syncing metadata */ 244 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 245 static int rushjob; /* number of slots to run ASAP */ 246 static int stat_rush_requests; /* number of times I/O speeded up */ 247 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 248 249 /* 250 * When shutting down the syncer, run it at four times normal speed. 251 */ 252 #define SYNCER_SHUTDOWN_SPEEDUP 4 253 static int sync_vnode_count; 254 static int syncer_worklist_len; 255 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 256 syncer_state; 257 258 /* 259 * Number of vnodes we want to exist at any one time. This is mostly used 260 * to size hash tables in vnode-related code. It is normally not used in 261 * getnewvnode(), as wantfreevnodes is normally nonzero.) 262 * 263 * XXX desiredvnodes is historical cruft and should not exist. 264 */ 265 int desiredvnodes; 266 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 267 &desiredvnodes, 0, "Maximum number of vnodes"); 268 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 269 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)"); 270 static int vnlru_nowhere; 271 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 272 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 273 274 /* 275 * Macros to control when a vnode is freed and recycled. All require 276 * the vnode interlock. 277 */ 278 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) 279 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) 280 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt) 281 282 283 /* 284 * Initialize the vnode management data structures. 285 */ 286 #ifndef MAXVNODES_MAX 287 #define MAXVNODES_MAX 100000 288 #endif 289 static void 290 vntblinit(void *dummy __unused) 291 { 292 293 /* 294 * Desiredvnodes is a function of the physical memory size and 295 * the kernel's heap size. Specifically, desiredvnodes scales 296 * in proportion to the physical memory size until two fifths 297 * of the kernel's heap size is consumed by vnodes and vm 298 * objects. 299 */ 300 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / 301 (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); 302 if (desiredvnodes > MAXVNODES_MAX) { 303 if (bootverbose) 304 printf("Reducing kern.maxvnodes %d -> %d\n", 305 desiredvnodes, MAXVNODES_MAX); 306 desiredvnodes = MAXVNODES_MAX; 307 } 308 wantfreevnodes = desiredvnodes / 4; 309 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 310 TAILQ_INIT(&vnode_free_list); 311 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 312 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 313 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 314 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 315 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 316 /* 317 * Initialize the filesystem syncer. 318 */ 319 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 320 &syncer_mask); 321 syncer_maxdelay = syncer_mask + 1; 322 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 323 } 324 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 325 326 327 /* 328 * Mark a mount point as busy. Used to synchronize access and to delay 329 * unmounting. Interlock is not released on failure. 330 */ 331 int 332 vfs_busy(struct mount *mp, int flags, struct mtx *interlkp, 333 struct thread *td) 334 { 335 int lkflags; 336 337 MNT_ILOCK(mp); 338 MNT_REF(mp); 339 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 340 if (flags & LK_NOWAIT) { 341 MNT_REL(mp); 342 MNT_IUNLOCK(mp); 343 return (ENOENT); 344 } 345 if (interlkp) 346 mtx_unlock(interlkp); 347 mp->mnt_kern_flag |= MNTK_MWAIT; 348 /* 349 * Since all busy locks are shared except the exclusive 350 * lock granted when unmounting, the only place that a 351 * wakeup needs to be done is at the release of the 352 * exclusive lock at the end of dounmount. 353 */ 354 msleep(mp, MNT_MTX(mp), PVFS, "vfs_busy", 0); 355 MNT_REL(mp); 356 MNT_IUNLOCK(mp); 357 if (interlkp) 358 mtx_lock(interlkp); 359 return (ENOENT); 360 } 361 if (interlkp) 362 mtx_unlock(interlkp); 363 lkflags = LK_SHARED | LK_INTERLOCK; 364 if (lockmgr(&mp->mnt_lock, lkflags, MNT_MTX(mp), td)) 365 panic("vfs_busy: unexpected lock failure"); 366 return (0); 367 } 368 369 /* 370 * Free a busy filesystem. 371 */ 372 void 373 vfs_unbusy(struct mount *mp, struct thread *td) 374 { 375 376 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 377 vfs_rel(mp); 378 } 379 380 /* 381 * Lookup a mount point by filesystem identifier. 382 */ 383 struct mount * 384 vfs_getvfs(fsid_t *fsid) 385 { 386 struct mount *mp; 387 388 mtx_lock(&mountlist_mtx); 389 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 390 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 391 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 392 vfs_ref(mp); 393 mtx_unlock(&mountlist_mtx); 394 return (mp); 395 } 396 } 397 mtx_unlock(&mountlist_mtx); 398 return ((struct mount *) 0); 399 } 400 401 /* 402 * Check if a user can access privileged mount options. 403 */ 404 int 405 vfs_suser(struct mount *mp, struct thread *td) 406 { 407 int error; 408 409 /* 410 * If the thread is jailed, but this is not a jail-friendly file 411 * system, deny immediately. 412 */ 413 if (jailed(td->td_ucred) && !(mp->mnt_vfc->vfc_flags & VFCF_JAIL)) 414 return (EPERM); 415 416 /* 417 * If the file system was mounted outside a jail and a jailed thread 418 * tries to access it, deny immediately. 419 */ 420 if (!jailed(mp->mnt_cred) && jailed(td->td_ucred)) 421 return (EPERM); 422 423 /* 424 * If the file system was mounted inside different jail that the jail of 425 * the calling thread, deny immediately. 426 */ 427 if (jailed(mp->mnt_cred) && jailed(td->td_ucred) && 428 mp->mnt_cred->cr_prison != td->td_ucred->cr_prison) { 429 return (EPERM); 430 } 431 432 if ((mp->mnt_flag & MNT_USER) == 0 || 433 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 434 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 435 return (error); 436 } 437 return (0); 438 } 439 440 /* 441 * Get a new unique fsid. Try to make its val[0] unique, since this value 442 * will be used to create fake device numbers for stat(). Also try (but 443 * not so hard) make its val[0] unique mod 2^16, since some emulators only 444 * support 16-bit device numbers. We end up with unique val[0]'s for the 445 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 446 * 447 * Keep in mind that several mounts may be running in parallel. Starting 448 * the search one past where the previous search terminated is both a 449 * micro-optimization and a defense against returning the same fsid to 450 * different mounts. 451 */ 452 void 453 vfs_getnewfsid(struct mount *mp) 454 { 455 static u_int16_t mntid_base; 456 struct mount *nmp; 457 fsid_t tfsid; 458 int mtype; 459 460 mtx_lock(&mntid_mtx); 461 mtype = mp->mnt_vfc->vfc_typenum; 462 tfsid.val[1] = mtype; 463 mtype = (mtype & 0xFF) << 24; 464 for (;;) { 465 tfsid.val[0] = makedev(255, 466 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 467 mntid_base++; 468 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 469 break; 470 vfs_rel(nmp); 471 } 472 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 473 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 474 mtx_unlock(&mntid_mtx); 475 } 476 477 /* 478 * Knob to control the precision of file timestamps: 479 * 480 * 0 = seconds only; nanoseconds zeroed. 481 * 1 = seconds and nanoseconds, accurate within 1/HZ. 482 * 2 = seconds and nanoseconds, truncated to microseconds. 483 * >=3 = seconds and nanoseconds, maximum precision. 484 */ 485 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 486 487 static int timestamp_precision = TSP_SEC; 488 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 489 ×tamp_precision, 0, ""); 490 491 /* 492 * Get a current timestamp. 493 */ 494 void 495 vfs_timestamp(struct timespec *tsp) 496 { 497 struct timeval tv; 498 499 switch (timestamp_precision) { 500 case TSP_SEC: 501 tsp->tv_sec = time_second; 502 tsp->tv_nsec = 0; 503 break; 504 case TSP_HZ: 505 getnanotime(tsp); 506 break; 507 case TSP_USEC: 508 microtime(&tv); 509 TIMEVAL_TO_TIMESPEC(&tv, tsp); 510 break; 511 case TSP_NSEC: 512 default: 513 nanotime(tsp); 514 break; 515 } 516 } 517 518 /* 519 * Set vnode attributes to VNOVAL 520 */ 521 void 522 vattr_null(struct vattr *vap) 523 { 524 525 vap->va_type = VNON; 526 vap->va_size = VNOVAL; 527 vap->va_bytes = VNOVAL; 528 vap->va_mode = VNOVAL; 529 vap->va_nlink = VNOVAL; 530 vap->va_uid = VNOVAL; 531 vap->va_gid = VNOVAL; 532 vap->va_fsid = VNOVAL; 533 vap->va_fileid = VNOVAL; 534 vap->va_blocksize = VNOVAL; 535 vap->va_rdev = VNOVAL; 536 vap->va_atime.tv_sec = VNOVAL; 537 vap->va_atime.tv_nsec = VNOVAL; 538 vap->va_mtime.tv_sec = VNOVAL; 539 vap->va_mtime.tv_nsec = VNOVAL; 540 vap->va_ctime.tv_sec = VNOVAL; 541 vap->va_ctime.tv_nsec = VNOVAL; 542 vap->va_birthtime.tv_sec = VNOVAL; 543 vap->va_birthtime.tv_nsec = VNOVAL; 544 vap->va_flags = VNOVAL; 545 vap->va_gen = VNOVAL; 546 vap->va_vaflags = 0; 547 } 548 549 /* 550 * This routine is called when we have too many vnodes. It attempts 551 * to free <count> vnodes and will potentially free vnodes that still 552 * have VM backing store (VM backing store is typically the cause 553 * of a vnode blowout so we want to do this). Therefore, this operation 554 * is not considered cheap. 555 * 556 * A number of conditions may prevent a vnode from being reclaimed. 557 * the buffer cache may have references on the vnode, a directory 558 * vnode may still have references due to the namei cache representing 559 * underlying files, or the vnode may be in active use. It is not 560 * desireable to reuse such vnodes. These conditions may cause the 561 * number of vnodes to reach some minimum value regardless of what 562 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 563 */ 564 static int 565 vlrureclaim(struct mount *mp) 566 { 567 struct thread *td; 568 struct vnode *vp; 569 int done; 570 int trigger; 571 int usevnodes; 572 int count; 573 574 /* 575 * Calculate the trigger point, don't allow user 576 * screwups to blow us up. This prevents us from 577 * recycling vnodes with lots of resident pages. We 578 * aren't trying to free memory, we are trying to 579 * free vnodes. 580 */ 581 usevnodes = desiredvnodes; 582 if (usevnodes <= 0) 583 usevnodes = 1; 584 trigger = cnt.v_page_count * 2 / usevnodes; 585 done = 0; 586 td = curthread; 587 vn_start_write(NULL, &mp, V_WAIT); 588 MNT_ILOCK(mp); 589 count = mp->mnt_nvnodelistsize / 10 + 1; 590 while (count != 0) { 591 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 592 while (vp != NULL && vp->v_type == VMARKER) 593 vp = TAILQ_NEXT(vp, v_nmntvnodes); 594 if (vp == NULL) 595 break; 596 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 597 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 598 --count; 599 if (!VI_TRYLOCK(vp)) 600 goto next_iter; 601 /* 602 * If it's been deconstructed already, it's still 603 * referenced, or it exceeds the trigger, skip it. 604 */ 605 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) || 606 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 607 vp->v_object->resident_page_count > trigger)) { 608 VI_UNLOCK(vp); 609 goto next_iter; 610 } 611 MNT_IUNLOCK(mp); 612 vholdl(vp); 613 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT, td)) { 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, td); 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, td); 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 = FIRST_THREAD_IN_PROC(p); 722 723 mtx_lock(&Giant); 724 725 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 726 SHUTDOWN_PRI_FIRST); 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 thread *td = curthread; 840 struct mount *vnmp; 841 842 CTR1(KTR_VFS, "vtryrecycle: trying vp %p", vp); 843 VNASSERT(vp->v_holdcnt, vp, 844 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 845 /* 846 * This vnode may found and locked via some other list, if so we 847 * can't recycle it yet. 848 */ 849 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 850 return (EWOULDBLOCK); 851 /* 852 * Don't recycle if its filesystem is being suspended. 853 */ 854 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 855 VOP_UNLOCK(vp, 0, td); 856 return (EBUSY); 857 } 858 /* 859 * If we got this far, we need to acquire the interlock and see if 860 * anyone picked up this vnode from another list. If not, we will 861 * mark it with DOOMED via vgonel() so that anyone who does find it 862 * will skip over it. 863 */ 864 VI_LOCK(vp); 865 if (vp->v_usecount) { 866 VOP_UNLOCK(vp, LK_INTERLOCK, td); 867 vn_finished_write(vnmp); 868 return (EBUSY); 869 } 870 if ((vp->v_iflag & VI_DOOMED) == 0) 871 vgonel(vp); 872 VOP_UNLOCK(vp, LK_INTERLOCK, td); 873 vn_finished_write(vnmp); 874 CTR1(KTR_VFS, "vtryrecycle: recycled vp %p", vp); 875 return (0); 876 } 877 878 /* 879 * Return the next vnode from the free list. 880 */ 881 int 882 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 883 struct vnode **vpp) 884 { 885 struct vnode *vp = NULL; 886 struct bufobj *bo; 887 888 mtx_lock(&vnode_free_list_mtx); 889 /* 890 * Lend our context to reclaim vnodes if they've exceeded the max. 891 */ 892 if (freevnodes > wantfreevnodes) 893 vnlru_free(1); 894 /* 895 * Wait for available vnodes. 896 */ 897 if (numvnodes > desiredvnodes) { 898 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) { 899 /* 900 * File system is beeing suspended, we cannot risk a 901 * deadlock here, so allocate new vnode anyway. 902 */ 903 if (freevnodes > wantfreevnodes) 904 vnlru_free(freevnodes - wantfreevnodes); 905 goto alloc; 906 } 907 if (vnlruproc_sig == 0) { 908 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 909 wakeup(vnlruproc); 910 } 911 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 912 "vlruwk", hz); 913 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 914 if (numvnodes > desiredvnodes) { 915 mtx_unlock(&vnode_free_list_mtx); 916 return (ENFILE); 917 } 918 #endif 919 } 920 alloc: 921 numvnodes++; 922 mtx_unlock(&vnode_free_list_mtx); 923 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 924 /* 925 * Setup locks. 926 */ 927 vp->v_vnlock = &vp->v_lock; 928 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 929 /* 930 * By default, don't allow shared locks unless filesystems 931 * opt-in. 932 */ 933 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE); 934 /* 935 * Initialize bufobj. 936 */ 937 bo = &vp->v_bufobj; 938 bo->__bo_vnode = vp; 939 bo->bo_mtx = &vp->v_interlock; 940 bo->bo_ops = &buf_ops_bio; 941 bo->bo_private = vp; 942 TAILQ_INIT(&bo->bo_clean.bv_hd); 943 TAILQ_INIT(&bo->bo_dirty.bv_hd); 944 /* 945 * Initialize namecache. 946 */ 947 LIST_INIT(&vp->v_cache_src); 948 TAILQ_INIT(&vp->v_cache_dst); 949 /* 950 * Finalize various vnode identity bits. 951 */ 952 vp->v_type = VNON; 953 vp->v_tag = tag; 954 vp->v_op = vops; 955 v_incr_usecount(vp); 956 vp->v_data = 0; 957 #ifdef MAC 958 mac_vnode_init(vp); 959 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 960 mac_vnode_associate_singlelabel(mp, vp); 961 else if (mp == NULL) 962 printf("NULL mp in getnewvnode()\n"); 963 #endif 964 if (mp != NULL) { 965 bo->bo_bsize = mp->mnt_stat.f_iosize; 966 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 967 vp->v_vflag |= VV_NOKNOTE; 968 } 969 970 CTR2(KTR_VFS, "getnewvnode: mp %p vp %p", mp, vp); 971 *vpp = vp; 972 return (0); 973 } 974 975 /* 976 * Delete from old mount point vnode list, if on one. 977 */ 978 static void 979 delmntque(struct vnode *vp) 980 { 981 struct mount *mp; 982 983 mp = vp->v_mount; 984 if (mp == NULL) 985 return; 986 MNT_ILOCK(mp); 987 vp->v_mount = NULL; 988 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 989 ("bad mount point vnode list size")); 990 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 991 mp->mnt_nvnodelistsize--; 992 MNT_REL(mp); 993 MNT_IUNLOCK(mp); 994 } 995 996 static void 997 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 998 { 999 struct thread *td; 1000 1001 td = curthread; /* XXX ? */ 1002 vp->v_data = NULL; 1003 vp->v_op = &dead_vnodeops; 1004 /* XXX non mp-safe fs may still call insmntque with vnode 1005 unlocked */ 1006 if (!VOP_ISLOCKED(vp, td)) 1007 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1008 vgone(vp); 1009 vput(vp); 1010 } 1011 1012 /* 1013 * Insert into list of vnodes for the new mount point, if available. 1014 */ 1015 int 1016 insmntque1(struct vnode *vp, struct mount *mp, 1017 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1018 { 1019 1020 KASSERT(vp->v_mount == NULL, 1021 ("insmntque: vnode already on per mount vnode list")); 1022 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1023 MNT_ILOCK(mp); 1024 if ((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1025 mp->mnt_nvnodelistsize == 0) { 1026 MNT_IUNLOCK(mp); 1027 if (dtr != NULL) 1028 dtr(vp, dtr_arg); 1029 return (EBUSY); 1030 } 1031 vp->v_mount = mp; 1032 MNT_REF(mp); 1033 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1034 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1035 ("neg mount point vnode list size")); 1036 mp->mnt_nvnodelistsize++; 1037 MNT_IUNLOCK(mp); 1038 return (0); 1039 } 1040 1041 int 1042 insmntque(struct vnode *vp, struct mount *mp) 1043 { 1044 1045 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1046 } 1047 1048 /* 1049 * Flush out and invalidate all buffers associated with a bufobj 1050 * Called with the underlying object locked. 1051 */ 1052 int 1053 bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag, 1054 int slptimeo) 1055 { 1056 int error; 1057 1058 BO_LOCK(bo); 1059 if (flags & V_SAVE) { 1060 error = bufobj_wwait(bo, slpflag, slptimeo); 1061 if (error) { 1062 BO_UNLOCK(bo); 1063 return (error); 1064 } 1065 if (bo->bo_dirty.bv_cnt > 0) { 1066 BO_UNLOCK(bo); 1067 if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0) 1068 return (error); 1069 /* 1070 * XXX We could save a lock/unlock if this was only 1071 * enabled under INVARIANTS 1072 */ 1073 BO_LOCK(bo); 1074 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1075 panic("vinvalbuf: dirty bufs"); 1076 } 1077 } 1078 /* 1079 * If you alter this loop please notice that interlock is dropped and 1080 * reacquired in flushbuflist. Special care is needed to ensure that 1081 * no race conditions occur from this. 1082 */ 1083 do { 1084 error = flushbuflist(&bo->bo_clean, 1085 flags, bo, slpflag, slptimeo); 1086 if (error == 0) 1087 error = flushbuflist(&bo->bo_dirty, 1088 flags, bo, slpflag, slptimeo); 1089 if (error != 0 && error != EAGAIN) { 1090 BO_UNLOCK(bo); 1091 return (error); 1092 } 1093 } while (error != 0); 1094 1095 /* 1096 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1097 * have write I/O in-progress but if there is a VM object then the 1098 * VM object can also have read-I/O in-progress. 1099 */ 1100 do { 1101 bufobj_wwait(bo, 0, 0); 1102 BO_UNLOCK(bo); 1103 if (bo->bo_object != NULL) { 1104 VM_OBJECT_LOCK(bo->bo_object); 1105 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1106 VM_OBJECT_UNLOCK(bo->bo_object); 1107 } 1108 BO_LOCK(bo); 1109 } while (bo->bo_numoutput > 0); 1110 BO_UNLOCK(bo); 1111 1112 /* 1113 * Destroy the copy in the VM cache, too. 1114 */ 1115 if (bo->bo_object != NULL) { 1116 VM_OBJECT_LOCK(bo->bo_object); 1117 vm_object_page_remove(bo->bo_object, 0, 0, 1118 (flags & V_SAVE) ? TRUE : FALSE); 1119 VM_OBJECT_UNLOCK(bo->bo_object); 1120 } 1121 1122 #ifdef INVARIANTS 1123 BO_LOCK(bo); 1124 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1125 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0)) 1126 panic("vinvalbuf: flush failed"); 1127 BO_UNLOCK(bo); 1128 #endif 1129 return (0); 1130 } 1131 1132 /* 1133 * Flush out and invalidate all buffers associated with a vnode. 1134 * Called with the underlying object locked. 1135 */ 1136 int 1137 vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag, 1138 int slptimeo) 1139 { 1140 1141 CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags); 1142 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1143 return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo)); 1144 } 1145 1146 /* 1147 * Flush out buffers on the specified list. 1148 * 1149 */ 1150 static int 1151 flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1152 int slptimeo) 1153 { 1154 struct buf *bp, *nbp; 1155 int retval, error; 1156 daddr_t lblkno; 1157 b_xflags_t xflags; 1158 1159 ASSERT_BO_LOCKED(bo); 1160 1161 retval = 0; 1162 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1163 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1164 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1165 continue; 1166 } 1167 lblkno = 0; 1168 xflags = 0; 1169 if (nbp != NULL) { 1170 lblkno = nbp->b_lblkno; 1171 xflags = nbp->b_xflags & 1172 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN); 1173 } 1174 retval = EAGAIN; 1175 error = BUF_TIMELOCK(bp, 1176 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo), 1177 "flushbuf", slpflag, slptimeo); 1178 if (error) { 1179 BO_LOCK(bo); 1180 return (error != ENOLCK ? error : EAGAIN); 1181 } 1182 KASSERT(bp->b_bufobj == bo, 1183 ("bp %p wrong b_bufobj %p should be %p", 1184 bp, bp->b_bufobj, bo)); 1185 if (bp->b_bufobj != bo) { /* XXX: necessary ? */ 1186 BUF_UNLOCK(bp); 1187 BO_LOCK(bo); 1188 return (EAGAIN); 1189 } 1190 /* 1191 * XXX Since there are no node locks for NFS, I 1192 * believe there is a slight chance that a delayed 1193 * write will occur while sleeping just above, so 1194 * check for it. 1195 */ 1196 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1197 (flags & V_SAVE)) { 1198 bremfree(bp); 1199 bp->b_flags |= B_ASYNC; 1200 bwrite(bp); 1201 BO_LOCK(bo); 1202 return (EAGAIN); /* XXX: why not loop ? */ 1203 } 1204 bremfree(bp); 1205 bp->b_flags |= (B_INVAL | B_RELBUF); 1206 bp->b_flags &= ~B_ASYNC; 1207 brelse(bp); 1208 BO_LOCK(bo); 1209 if (nbp != NULL && 1210 (nbp->b_bufobj != bo || 1211 nbp->b_lblkno != lblkno || 1212 (nbp->b_xflags & 1213 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags)) 1214 break; /* nbp invalid */ 1215 } 1216 return (retval); 1217 } 1218 1219 /* 1220 * Truncate a file's buffer and pages to a specified length. This 1221 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1222 * sync activity. 1223 */ 1224 int 1225 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td, 1226 off_t length, int blksize) 1227 { 1228 struct buf *bp, *nbp; 1229 int anyfreed; 1230 int trunclbn; 1231 struct bufobj *bo; 1232 1233 CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length); 1234 /* 1235 * Round up to the *next* lbn. 1236 */ 1237 trunclbn = (length + blksize - 1) / blksize; 1238 1239 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1240 restart: 1241 VI_LOCK(vp); 1242 bo = &vp->v_bufobj; 1243 anyfreed = 1; 1244 for (;anyfreed;) { 1245 anyfreed = 0; 1246 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1247 if (bp->b_lblkno < trunclbn) 1248 continue; 1249 if (BUF_LOCK(bp, 1250 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1251 VI_MTX(vp)) == ENOLCK) 1252 goto restart; 1253 1254 bremfree(bp); 1255 bp->b_flags |= (B_INVAL | B_RELBUF); 1256 bp->b_flags &= ~B_ASYNC; 1257 brelse(bp); 1258 anyfreed = 1; 1259 1260 if (nbp != NULL && 1261 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1262 (nbp->b_vp != vp) || 1263 (nbp->b_flags & B_DELWRI))) { 1264 goto restart; 1265 } 1266 VI_LOCK(vp); 1267 } 1268 1269 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1270 if (bp->b_lblkno < trunclbn) 1271 continue; 1272 if (BUF_LOCK(bp, 1273 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1274 VI_MTX(vp)) == ENOLCK) 1275 goto restart; 1276 bremfree(bp); 1277 bp->b_flags |= (B_INVAL | B_RELBUF); 1278 bp->b_flags &= ~B_ASYNC; 1279 brelse(bp); 1280 anyfreed = 1; 1281 if (nbp != NULL && 1282 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1283 (nbp->b_vp != vp) || 1284 (nbp->b_flags & B_DELWRI) == 0)) { 1285 goto restart; 1286 } 1287 VI_LOCK(vp); 1288 } 1289 } 1290 1291 if (length > 0) { 1292 restartsync: 1293 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1294 if (bp->b_lblkno > 0) 1295 continue; 1296 /* 1297 * Since we hold the vnode lock this should only 1298 * fail if we're racing with the buf daemon. 1299 */ 1300 if (BUF_LOCK(bp, 1301 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1302 VI_MTX(vp)) == ENOLCK) { 1303 goto restart; 1304 } 1305 VNASSERT((bp->b_flags & B_DELWRI), vp, 1306 ("buf(%p) on dirty queue without DELWRI", bp)); 1307 1308 bremfree(bp); 1309 bawrite(bp); 1310 VI_LOCK(vp); 1311 goto restartsync; 1312 } 1313 } 1314 1315 bufobj_wwait(bo, 0, 0); 1316 VI_UNLOCK(vp); 1317 vnode_pager_setsize(vp, length); 1318 1319 return (0); 1320 } 1321 1322 /* 1323 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1324 * a vnode. 1325 * 1326 * NOTE: We have to deal with the special case of a background bitmap 1327 * buffer, a situation where two buffers will have the same logical 1328 * block offset. We want (1) only the foreground buffer to be accessed 1329 * in a lookup and (2) must differentiate between the foreground and 1330 * background buffer in the splay tree algorithm because the splay 1331 * tree cannot normally handle multiple entities with the same 'index'. 1332 * We accomplish this by adding differentiating flags to the splay tree's 1333 * numerical domain. 1334 */ 1335 static 1336 struct buf * 1337 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1338 { 1339 struct buf dummy; 1340 struct buf *lefttreemax, *righttreemin, *y; 1341 1342 if (root == NULL) 1343 return (NULL); 1344 lefttreemax = righttreemin = &dummy; 1345 for (;;) { 1346 if (lblkno < root->b_lblkno || 1347 (lblkno == root->b_lblkno && 1348 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1349 if ((y = root->b_left) == NULL) 1350 break; 1351 if (lblkno < y->b_lblkno) { 1352 /* Rotate right. */ 1353 root->b_left = y->b_right; 1354 y->b_right = root; 1355 root = y; 1356 if ((y = root->b_left) == NULL) 1357 break; 1358 } 1359 /* Link into the new root's right tree. */ 1360 righttreemin->b_left = root; 1361 righttreemin = root; 1362 } else if (lblkno > root->b_lblkno || 1363 (lblkno == root->b_lblkno && 1364 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1365 if ((y = root->b_right) == NULL) 1366 break; 1367 if (lblkno > y->b_lblkno) { 1368 /* Rotate left. */ 1369 root->b_right = y->b_left; 1370 y->b_left = root; 1371 root = y; 1372 if ((y = root->b_right) == NULL) 1373 break; 1374 } 1375 /* Link into the new root's left tree. */ 1376 lefttreemax->b_right = root; 1377 lefttreemax = root; 1378 } else { 1379 break; 1380 } 1381 root = y; 1382 } 1383 /* Assemble the new root. */ 1384 lefttreemax->b_right = root->b_left; 1385 righttreemin->b_left = root->b_right; 1386 root->b_left = dummy.b_right; 1387 root->b_right = dummy.b_left; 1388 return (root); 1389 } 1390 1391 static void 1392 buf_vlist_remove(struct buf *bp) 1393 { 1394 struct buf *root; 1395 struct bufv *bv; 1396 1397 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1398 ASSERT_BO_LOCKED(bp->b_bufobj); 1399 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1400 (BX_VNDIRTY|BX_VNCLEAN), 1401 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1402 if (bp->b_xflags & BX_VNDIRTY) 1403 bv = &bp->b_bufobj->bo_dirty; 1404 else 1405 bv = &bp->b_bufobj->bo_clean; 1406 if (bp != bv->bv_root) { 1407 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1408 KASSERT(root == bp, ("splay lookup failed in remove")); 1409 } 1410 if (bp->b_left == NULL) { 1411 root = bp->b_right; 1412 } else { 1413 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1414 root->b_right = bp->b_right; 1415 } 1416 bv->bv_root = root; 1417 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1418 bv->bv_cnt--; 1419 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1420 } 1421 1422 /* 1423 * Add the buffer to the sorted clean or dirty block list using a 1424 * splay tree algorithm. 1425 * 1426 * NOTE: xflags is passed as a constant, optimizing this inline function! 1427 */ 1428 static void 1429 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1430 { 1431 struct buf *root; 1432 struct bufv *bv; 1433 1434 ASSERT_BO_LOCKED(bo); 1435 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1436 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1437 bp->b_xflags |= xflags; 1438 if (xflags & BX_VNDIRTY) 1439 bv = &bo->bo_dirty; 1440 else 1441 bv = &bo->bo_clean; 1442 1443 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1444 if (root == NULL) { 1445 bp->b_left = NULL; 1446 bp->b_right = NULL; 1447 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1448 } else if (bp->b_lblkno < root->b_lblkno || 1449 (bp->b_lblkno == root->b_lblkno && 1450 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1451 bp->b_left = root->b_left; 1452 bp->b_right = root; 1453 root->b_left = NULL; 1454 TAILQ_INSERT_BEFORE(root, bp, b_bobufs); 1455 } else { 1456 bp->b_right = root->b_right; 1457 bp->b_left = root; 1458 root->b_right = NULL; 1459 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs); 1460 } 1461 bv->bv_cnt++; 1462 bv->bv_root = bp; 1463 } 1464 1465 /* 1466 * Lookup a buffer using the splay tree. Note that we specifically avoid 1467 * shadow buffers used in background bitmap writes. 1468 * 1469 * This code isn't quite efficient as it could be because we are maintaining 1470 * two sorted lists and do not know which list the block resides in. 1471 * 1472 * During a "make buildworld" the desired buffer is found at one of 1473 * the roots more than 60% of the time. Thus, checking both roots 1474 * before performing either splay eliminates unnecessary splays on the 1475 * first tree splayed. 1476 */ 1477 struct buf * 1478 gbincore(struct bufobj *bo, daddr_t lblkno) 1479 { 1480 struct buf *bp; 1481 1482 ASSERT_BO_LOCKED(bo); 1483 if ((bp = bo->bo_clean.bv_root) != NULL && 1484 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1485 return (bp); 1486 if ((bp = bo->bo_dirty.bv_root) != NULL && 1487 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1488 return (bp); 1489 if ((bp = bo->bo_clean.bv_root) != NULL) { 1490 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp); 1491 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1492 return (bp); 1493 } 1494 if ((bp = bo->bo_dirty.bv_root) != NULL) { 1495 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp); 1496 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1497 return (bp); 1498 } 1499 return (NULL); 1500 } 1501 1502 /* 1503 * Associate a buffer with a vnode. 1504 */ 1505 void 1506 bgetvp(struct vnode *vp, struct buf *bp) 1507 { 1508 1509 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 1510 1511 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 1512 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 1513 ("bgetvp: bp already attached! %p", bp)); 1514 1515 ASSERT_VI_LOCKED(vp, "bgetvp"); 1516 vholdl(vp); 1517 if (VFS_NEEDSGIANT(vp->v_mount) || 1518 vp->v_bufobj.bo_flag & BO_NEEDSGIANT) 1519 bp->b_flags |= B_NEEDSGIANT; 1520 bp->b_vp = vp; 1521 bp->b_bufobj = &vp->v_bufobj; 1522 /* 1523 * Insert onto list for new vnode. 1524 */ 1525 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN); 1526 } 1527 1528 /* 1529 * Disassociate a buffer from a vnode. 1530 */ 1531 void 1532 brelvp(struct buf *bp) 1533 { 1534 struct bufobj *bo; 1535 struct vnode *vp; 1536 1537 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 1538 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1539 1540 /* 1541 * Delete from old vnode list, if on one. 1542 */ 1543 vp = bp->b_vp; /* XXX */ 1544 bo = bp->b_bufobj; 1545 BO_LOCK(bo); 1546 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1547 buf_vlist_remove(bp); 1548 else 1549 panic("brelvp: Buffer %p not on queue.", bp); 1550 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1551 bo->bo_flag &= ~BO_ONWORKLST; 1552 mtx_lock(&sync_mtx); 1553 LIST_REMOVE(bo, bo_synclist); 1554 syncer_worklist_len--; 1555 mtx_unlock(&sync_mtx); 1556 } 1557 bp->b_flags &= ~B_NEEDSGIANT; 1558 bp->b_vp = NULL; 1559 bp->b_bufobj = NULL; 1560 vdropl(vp); 1561 } 1562 1563 /* 1564 * Add an item to the syncer work queue. 1565 */ 1566 static void 1567 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 1568 { 1569 int slot; 1570 1571 ASSERT_BO_LOCKED(bo); 1572 1573 mtx_lock(&sync_mtx); 1574 if (bo->bo_flag & BO_ONWORKLST) 1575 LIST_REMOVE(bo, bo_synclist); 1576 else { 1577 bo->bo_flag |= BO_ONWORKLST; 1578 syncer_worklist_len++; 1579 } 1580 1581 if (delay > syncer_maxdelay - 2) 1582 delay = syncer_maxdelay - 2; 1583 slot = (syncer_delayno + delay) & syncer_mask; 1584 1585 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 1586 mtx_unlock(&sync_mtx); 1587 } 1588 1589 static int 1590 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1591 { 1592 int error, len; 1593 1594 mtx_lock(&sync_mtx); 1595 len = syncer_worklist_len - sync_vnode_count; 1596 mtx_unlock(&sync_mtx); 1597 error = SYSCTL_OUT(req, &len, sizeof(len)); 1598 return (error); 1599 } 1600 1601 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1602 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1603 1604 static struct proc *updateproc; 1605 static void sched_sync(void); 1606 static struct kproc_desc up_kp = { 1607 "syncer", 1608 sched_sync, 1609 &updateproc 1610 }; 1611 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1612 1613 static int 1614 sync_vnode(struct bufobj *bo, struct thread *td) 1615 { 1616 struct vnode *vp; 1617 struct mount *mp; 1618 1619 vp = bo->__bo_vnode; /* XXX */ 1620 if (VOP_ISLOCKED(vp, NULL) != 0) 1621 return (1); 1622 if (VI_TRYLOCK(vp) == 0) 1623 return (1); 1624 /* 1625 * We use vhold in case the vnode does not 1626 * successfully sync. vhold prevents the vnode from 1627 * going away when we unlock the sync_mtx so that 1628 * we can acquire the vnode interlock. 1629 */ 1630 vholdl(vp); 1631 mtx_unlock(&sync_mtx); 1632 VI_UNLOCK(vp); 1633 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1634 vdrop(vp); 1635 mtx_lock(&sync_mtx); 1636 return (1); 1637 } 1638 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1639 (void) VOP_FSYNC(vp, MNT_LAZY, td); 1640 VOP_UNLOCK(vp, 0, td); 1641 vn_finished_write(mp); 1642 VI_LOCK(vp); 1643 if ((bo->bo_flag & BO_ONWORKLST) != 0) { 1644 /* 1645 * Put us back on the worklist. The worklist 1646 * routine will remove us from our current 1647 * position and then add us back in at a later 1648 * position. 1649 */ 1650 vn_syncer_add_to_worklist(bo, syncdelay); 1651 } 1652 vdropl(vp); 1653 mtx_lock(&sync_mtx); 1654 return (0); 1655 } 1656 1657 /* 1658 * System filesystem synchronizer daemon. 1659 */ 1660 static void 1661 sched_sync(void) 1662 { 1663 struct synclist *next; 1664 struct synclist *slp; 1665 struct bufobj *bo; 1666 long starttime; 1667 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); 1668 static int dummychan; 1669 int last_work_seen; 1670 int net_worklist_len; 1671 int syncer_final_iter; 1672 int first_printf; 1673 int error; 1674 1675 mtx_lock(&Giant); 1676 last_work_seen = 0; 1677 syncer_final_iter = 0; 1678 first_printf = 1; 1679 syncer_state = SYNCER_RUNNING; 1680 starttime = time_uptime; 1681 td->td_pflags |= TDP_NORUNNINGBUF; 1682 1683 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 1684 SHUTDOWN_PRI_LAST); 1685 1686 mtx_lock(&sync_mtx); 1687 for (;;) { 1688 if (syncer_state == SYNCER_FINAL_DELAY && 1689 syncer_final_iter == 0) { 1690 mtx_unlock(&sync_mtx); 1691 kproc_suspend_check(td->td_proc); 1692 mtx_lock(&sync_mtx); 1693 } 1694 net_worklist_len = syncer_worklist_len - sync_vnode_count; 1695 if (syncer_state != SYNCER_RUNNING && 1696 starttime != time_uptime) { 1697 if (first_printf) { 1698 printf("\nSyncing disks, vnodes remaining..."); 1699 first_printf = 0; 1700 } 1701 printf("%d ", net_worklist_len); 1702 } 1703 starttime = time_uptime; 1704 1705 /* 1706 * Push files whose dirty time has expired. Be careful 1707 * of interrupt race on slp queue. 1708 * 1709 * Skip over empty worklist slots when shutting down. 1710 */ 1711 do { 1712 slp = &syncer_workitem_pending[syncer_delayno]; 1713 syncer_delayno += 1; 1714 if (syncer_delayno == syncer_maxdelay) 1715 syncer_delayno = 0; 1716 next = &syncer_workitem_pending[syncer_delayno]; 1717 /* 1718 * If the worklist has wrapped since the 1719 * it was emptied of all but syncer vnodes, 1720 * switch to the FINAL_DELAY state and run 1721 * for one more second. 1722 */ 1723 if (syncer_state == SYNCER_SHUTTING_DOWN && 1724 net_worklist_len == 0 && 1725 last_work_seen == syncer_delayno) { 1726 syncer_state = SYNCER_FINAL_DELAY; 1727 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 1728 } 1729 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 1730 syncer_worklist_len > 0); 1731 1732 /* 1733 * Keep track of the last time there was anything 1734 * on the worklist other than syncer vnodes. 1735 * Return to the SHUTTING_DOWN state if any 1736 * new work appears. 1737 */ 1738 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 1739 last_work_seen = syncer_delayno; 1740 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 1741 syncer_state = SYNCER_SHUTTING_DOWN; 1742 while ((bo = LIST_FIRST(slp)) != NULL) { 1743 error = sync_vnode(bo, td); 1744 if (error == 1) { 1745 LIST_REMOVE(bo, bo_synclist); 1746 LIST_INSERT_HEAD(next, bo, bo_synclist); 1747 continue; 1748 } 1749 } 1750 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 1751 syncer_final_iter--; 1752 /* 1753 * The variable rushjob allows the kernel to speed up the 1754 * processing of the filesystem syncer process. A rushjob 1755 * value of N tells the filesystem syncer to process the next 1756 * N seconds worth of work on its queue ASAP. Currently rushjob 1757 * is used by the soft update code to speed up the filesystem 1758 * syncer process when the incore state is getting so far 1759 * ahead of the disk that the kernel memory pool is being 1760 * threatened with exhaustion. 1761 */ 1762 if (rushjob > 0) { 1763 rushjob -= 1; 1764 continue; 1765 } 1766 /* 1767 * Just sleep for a short period of time between 1768 * iterations when shutting down to allow some I/O 1769 * to happen. 1770 * 1771 * If it has taken us less than a second to process the 1772 * current work, then wait. Otherwise start right over 1773 * again. We can still lose time if any single round 1774 * takes more than two seconds, but it does not really 1775 * matter as we are just trying to generally pace the 1776 * filesystem activity. 1777 */ 1778 if (syncer_state != SYNCER_RUNNING) 1779 msleep(&dummychan, &sync_mtx, PPAUSE, "syncfnl", 1780 hz / SYNCER_SHUTDOWN_SPEEDUP); 1781 else if (time_uptime == starttime) 1782 msleep(&lbolt, &sync_mtx, PPAUSE, "syncer", 0); 1783 } 1784 } 1785 1786 /* 1787 * Request the syncer daemon to speed up its work. 1788 * We never push it to speed up more than half of its 1789 * normal turn time, otherwise it could take over the cpu. 1790 */ 1791 int 1792 speedup_syncer(void) 1793 { 1794 struct thread *td; 1795 int ret = 0; 1796 1797 td = FIRST_THREAD_IN_PROC(updateproc); 1798 sleepq_remove(td, &lbolt); 1799 mtx_lock(&sync_mtx); 1800 if (rushjob < syncdelay / 2) { 1801 rushjob += 1; 1802 stat_rush_requests += 1; 1803 ret = 1; 1804 } 1805 mtx_unlock(&sync_mtx); 1806 return (ret); 1807 } 1808 1809 /* 1810 * Tell the syncer to speed up its work and run though its work 1811 * list several times, then tell it to shut down. 1812 */ 1813 static void 1814 syncer_shutdown(void *arg, int howto) 1815 { 1816 struct thread *td; 1817 1818 if (howto & RB_NOSYNC) 1819 return; 1820 td = FIRST_THREAD_IN_PROC(updateproc); 1821 sleepq_remove(td, &lbolt); 1822 mtx_lock(&sync_mtx); 1823 syncer_state = SYNCER_SHUTTING_DOWN; 1824 rushjob = 0; 1825 mtx_unlock(&sync_mtx); 1826 kproc_shutdown(arg, howto); 1827 } 1828 1829 /* 1830 * Reassign a buffer from one vnode to another. 1831 * Used to assign file specific control information 1832 * (indirect blocks) to the vnode to which they belong. 1833 */ 1834 void 1835 reassignbuf(struct buf *bp) 1836 { 1837 struct vnode *vp; 1838 struct bufobj *bo; 1839 int delay; 1840 #ifdef INVARIANTS 1841 struct bufv *bv; 1842 #endif 1843 1844 vp = bp->b_vp; 1845 bo = bp->b_bufobj; 1846 ++reassignbufcalls; 1847 1848 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 1849 bp, bp->b_vp, bp->b_flags); 1850 /* 1851 * B_PAGING flagged buffers cannot be reassigned because their vp 1852 * is not fully linked in. 1853 */ 1854 if (bp->b_flags & B_PAGING) 1855 panic("cannot reassign paging buffer"); 1856 1857 /* 1858 * Delete from old vnode list, if on one. 1859 */ 1860 VI_LOCK(vp); 1861 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1862 buf_vlist_remove(bp); 1863 else 1864 panic("reassignbuf: Buffer %p not on queue.", bp); 1865 /* 1866 * If dirty, put on list of dirty buffers; otherwise insert onto list 1867 * of clean buffers. 1868 */ 1869 if (bp->b_flags & B_DELWRI) { 1870 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 1871 switch (vp->v_type) { 1872 case VDIR: 1873 delay = dirdelay; 1874 break; 1875 case VCHR: 1876 delay = metadelay; 1877 break; 1878 default: 1879 delay = filedelay; 1880 } 1881 vn_syncer_add_to_worklist(bo, delay); 1882 } 1883 buf_vlist_add(bp, bo, BX_VNDIRTY); 1884 } else { 1885 buf_vlist_add(bp, bo, BX_VNCLEAN); 1886 1887 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1888 mtx_lock(&sync_mtx); 1889 LIST_REMOVE(bo, bo_synclist); 1890 syncer_worklist_len--; 1891 mtx_unlock(&sync_mtx); 1892 bo->bo_flag &= ~BO_ONWORKLST; 1893 } 1894 } 1895 #ifdef INVARIANTS 1896 bv = &bo->bo_clean; 1897 bp = TAILQ_FIRST(&bv->bv_hd); 1898 KASSERT(bp == NULL || bp->b_bufobj == bo, 1899 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1900 bp = TAILQ_LAST(&bv->bv_hd, buflists); 1901 KASSERT(bp == NULL || bp->b_bufobj == bo, 1902 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1903 bv = &bo->bo_dirty; 1904 bp = TAILQ_FIRST(&bv->bv_hd); 1905 KASSERT(bp == NULL || bp->b_bufobj == bo, 1906 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1907 bp = TAILQ_LAST(&bv->bv_hd, buflists); 1908 KASSERT(bp == NULL || bp->b_bufobj == bo, 1909 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1910 #endif 1911 VI_UNLOCK(vp); 1912 } 1913 1914 /* 1915 * Increment the use and hold counts on the vnode, taking care to reference 1916 * the driver's usecount if this is a chardev. The vholdl() will remove 1917 * the vnode from the free list if it is presently free. Requires the 1918 * vnode interlock and returns with it held. 1919 */ 1920 static void 1921 v_incr_usecount(struct vnode *vp) 1922 { 1923 1924 CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n", 1925 vp, vp->v_holdcnt, vp->v_usecount); 1926 vp->v_usecount++; 1927 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1928 dev_lock(); 1929 vp->v_rdev->si_usecount++; 1930 dev_unlock(); 1931 } 1932 vholdl(vp); 1933 } 1934 1935 /* 1936 * Turn a holdcnt into a use+holdcnt such that only one call to 1937 * v_decr_usecount is needed. 1938 */ 1939 static void 1940 v_upgrade_usecount(struct vnode *vp) 1941 { 1942 1943 CTR3(KTR_VFS, "v_upgrade_usecount: vp %p holdcnt %d usecount %d\n", 1944 vp, vp->v_holdcnt, vp->v_usecount); 1945 vp->v_usecount++; 1946 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1947 dev_lock(); 1948 vp->v_rdev->si_usecount++; 1949 dev_unlock(); 1950 } 1951 } 1952 1953 /* 1954 * Decrement the vnode use and hold count along with the driver's usecount 1955 * if this is a chardev. The vdropl() below releases the vnode interlock 1956 * as it may free the vnode. 1957 */ 1958 static void 1959 v_decr_usecount(struct vnode *vp) 1960 { 1961 1962 CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n", 1963 vp, vp->v_holdcnt, vp->v_usecount); 1964 ASSERT_VI_LOCKED(vp, __FUNCTION__); 1965 VNASSERT(vp->v_usecount > 0, vp, 1966 ("v_decr_usecount: negative usecount")); 1967 vp->v_usecount--; 1968 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1969 dev_lock(); 1970 vp->v_rdev->si_usecount--; 1971 dev_unlock(); 1972 } 1973 vdropl(vp); 1974 } 1975 1976 /* 1977 * Decrement only the use count and driver use count. This is intended to 1978 * be paired with a follow on vdropl() to release the remaining hold count. 1979 * In this way we may vgone() a vnode with a 0 usecount without risk of 1980 * having it end up on a free list because the hold count is kept above 0. 1981 */ 1982 static void 1983 v_decr_useonly(struct vnode *vp) 1984 { 1985 1986 CTR3(KTR_VFS, "v_decr_useonly: 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_useonly: 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 } 1998 1999 /* 2000 * Grab a particular vnode from the free list, increment its 2001 * reference count and lock it. The vnode lock bit is set if the 2002 * vnode is being eliminated in vgone. The process is awakened 2003 * when the transition is completed, and an error returned to 2004 * indicate that the vnode is no longer usable (possibly having 2005 * been changed to a new filesystem type). 2006 */ 2007 int 2008 vget(struct vnode *vp, int flags, struct thread *td) 2009 { 2010 int oweinact; 2011 int oldflags; 2012 int error; 2013 2014 error = 0; 2015 oldflags = flags; 2016 oweinact = 0; 2017 VFS_ASSERT_GIANT(vp->v_mount); 2018 if ((flags & LK_INTERLOCK) == 0) 2019 VI_LOCK(vp); 2020 /* 2021 * If the inactive call was deferred because vput() was called 2022 * with a shared lock, we have to do it here before another thread 2023 * gets a reference to data that should be dead. 2024 */ 2025 if (vp->v_iflag & VI_OWEINACT) { 2026 if (flags & LK_NOWAIT) { 2027 VI_UNLOCK(vp); 2028 return (EBUSY); 2029 } 2030 flags &= ~LK_TYPE_MASK; 2031 flags |= LK_EXCLUSIVE; 2032 oweinact = 1; 2033 } 2034 vholdl(vp); 2035 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 2036 vdrop(vp); 2037 return (error); 2038 } 2039 VI_LOCK(vp); 2040 /* Upgrade our holdcnt to a usecount. */ 2041 v_upgrade_usecount(vp); 2042 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2043 panic("vget: vn_lock failed to return ENOENT\n"); 2044 if (oweinact) { 2045 if (vp->v_iflag & VI_OWEINACT) 2046 vinactive(vp, td); 2047 VI_UNLOCK(vp); 2048 if ((oldflags & LK_TYPE_MASK) == 0) 2049 VOP_UNLOCK(vp, 0, td); 2050 } else 2051 VI_UNLOCK(vp); 2052 return (0); 2053 } 2054 2055 /* 2056 * Increase the reference count of a vnode. 2057 */ 2058 void 2059 vref(struct vnode *vp) 2060 { 2061 2062 VI_LOCK(vp); 2063 v_incr_usecount(vp); 2064 VI_UNLOCK(vp); 2065 } 2066 2067 /* 2068 * Return reference count of a vnode. 2069 * 2070 * The results of this call are only guaranteed when some mechanism other 2071 * than the VI lock is used to stop other processes from gaining references 2072 * to the vnode. This may be the case if the caller holds the only reference. 2073 * This is also useful when stale data is acceptable as race conditions may 2074 * be accounted for by some other means. 2075 */ 2076 int 2077 vrefcnt(struct vnode *vp) 2078 { 2079 int usecnt; 2080 2081 VI_LOCK(vp); 2082 usecnt = vp->v_usecount; 2083 VI_UNLOCK(vp); 2084 2085 return (usecnt); 2086 } 2087 2088 2089 /* 2090 * Vnode put/release. 2091 * If count drops to zero, call inactive routine and return to freelist. 2092 */ 2093 void 2094 vrele(struct vnode *vp) 2095 { 2096 struct thread *td = curthread; /* XXX */ 2097 2098 KASSERT(vp != NULL, ("vrele: null vp")); 2099 VFS_ASSERT_GIANT(vp->v_mount); 2100 2101 VI_LOCK(vp); 2102 2103 /* Skip this v_writecount check if we're going to panic below. */ 2104 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2105 ("vrele: missed vn_close")); 2106 2107 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2108 vp->v_usecount == 1)) { 2109 v_decr_usecount(vp); 2110 return; 2111 } 2112 if (vp->v_usecount != 1) { 2113 #ifdef DIAGNOSTIC 2114 vprint("vrele: negative ref count", vp); 2115 #endif 2116 VI_UNLOCK(vp); 2117 panic("vrele: negative ref cnt"); 2118 } 2119 /* 2120 * We want to hold the vnode until the inactive finishes to 2121 * prevent vgone() races. We drop the use count here and the 2122 * hold count below when we're done. 2123 */ 2124 v_decr_useonly(vp); 2125 /* 2126 * We must call VOP_INACTIVE with the node locked. Mark 2127 * as VI_DOINGINACT to avoid recursion. 2128 */ 2129 vp->v_iflag |= VI_OWEINACT; 2130 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 2131 VI_LOCK(vp); 2132 if (vp->v_usecount > 0) 2133 vp->v_iflag &= ~VI_OWEINACT; 2134 if (vp->v_iflag & VI_OWEINACT) 2135 vinactive(vp, td); 2136 VOP_UNLOCK(vp, 0, td); 2137 } else { 2138 VI_LOCK(vp); 2139 if (vp->v_usecount > 0) 2140 vp->v_iflag &= ~VI_OWEINACT; 2141 } 2142 vdropl(vp); 2143 } 2144 2145 /* 2146 * Release an already locked vnode. This give the same effects as 2147 * unlock+vrele(), but takes less time and avoids releasing and 2148 * re-aquiring the lock (as vrele() acquires the lock internally.) 2149 */ 2150 void 2151 vput(struct vnode *vp) 2152 { 2153 struct thread *td = curthread; /* XXX */ 2154 int error; 2155 2156 KASSERT(vp != NULL, ("vput: null vp")); 2157 ASSERT_VOP_LOCKED(vp, "vput"); 2158 VFS_ASSERT_GIANT(vp->v_mount); 2159 VI_LOCK(vp); 2160 /* Skip this v_writecount check if we're going to panic below. */ 2161 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2162 ("vput: missed vn_close")); 2163 error = 0; 2164 2165 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2166 vp->v_usecount == 1)) { 2167 VOP_UNLOCK(vp, 0, td); 2168 v_decr_usecount(vp); 2169 return; 2170 } 2171 2172 if (vp->v_usecount != 1) { 2173 #ifdef DIAGNOSTIC 2174 vprint("vput: negative ref count", vp); 2175 #endif 2176 panic("vput: negative ref cnt"); 2177 } 2178 /* 2179 * We want to hold the vnode until the inactive finishes to 2180 * prevent vgone() races. We drop the use count here and the 2181 * hold count below when we're done. 2182 */ 2183 v_decr_useonly(vp); 2184 vp->v_iflag |= VI_OWEINACT; 2185 if (VOP_ISLOCKED(vp, NULL) != LK_EXCLUSIVE) { 2186 error = VOP_LOCK(vp, LK_EXCLUPGRADE|LK_INTERLOCK|LK_NOWAIT, td); 2187 VI_LOCK(vp); 2188 if (error) { 2189 if (vp->v_usecount > 0) 2190 vp->v_iflag &= ~VI_OWEINACT; 2191 goto done; 2192 } 2193 } 2194 if (vp->v_usecount > 0) 2195 vp->v_iflag &= ~VI_OWEINACT; 2196 if (vp->v_iflag & VI_OWEINACT) 2197 vinactive(vp, td); 2198 VOP_UNLOCK(vp, 0, td); 2199 done: 2200 vdropl(vp); 2201 } 2202 2203 /* 2204 * Somebody doesn't want the vnode recycled. 2205 */ 2206 void 2207 vhold(struct vnode *vp) 2208 { 2209 2210 VI_LOCK(vp); 2211 vholdl(vp); 2212 VI_UNLOCK(vp); 2213 } 2214 2215 void 2216 vholdl(struct vnode *vp) 2217 { 2218 2219 vp->v_holdcnt++; 2220 if (VSHOULDBUSY(vp)) 2221 vbusy(vp); 2222 } 2223 2224 /* 2225 * Note that there is one less who cares about this vnode. vdrop() is the 2226 * opposite of vhold(). 2227 */ 2228 void 2229 vdrop(struct vnode *vp) 2230 { 2231 2232 VI_LOCK(vp); 2233 vdropl(vp); 2234 } 2235 2236 /* 2237 * Drop the hold count of the vnode. If this is the last reference to 2238 * the vnode we will free it if it has been vgone'd otherwise it is 2239 * placed on the free list. 2240 */ 2241 void 2242 vdropl(struct vnode *vp) 2243 { 2244 2245 ASSERT_VI_LOCKED(vp, "vdropl"); 2246 if (vp->v_holdcnt <= 0) 2247 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2248 vp->v_holdcnt--; 2249 if (vp->v_holdcnt == 0) { 2250 if (vp->v_iflag & VI_DOOMED) { 2251 vdestroy(vp); 2252 return; 2253 } else 2254 vfree(vp); 2255 } 2256 VI_UNLOCK(vp); 2257 } 2258 2259 /* 2260 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 2261 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 2262 * OWEINACT tracks whether a vnode missed a call to inactive due to a 2263 * failed lock upgrade. 2264 */ 2265 static void 2266 vinactive(struct vnode *vp, struct thread *td) 2267 { 2268 2269 ASSERT_VOP_LOCKED(vp, "vinactive"); 2270 ASSERT_VI_LOCKED(vp, "vinactive"); 2271 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 2272 ("vinactive: recursed on VI_DOINGINACT")); 2273 vp->v_iflag |= VI_DOINGINACT; 2274 vp->v_iflag &= ~VI_OWEINACT; 2275 VI_UNLOCK(vp); 2276 VOP_INACTIVE(vp, td); 2277 VI_LOCK(vp); 2278 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 2279 ("vinactive: lost VI_DOINGINACT")); 2280 vp->v_iflag &= ~VI_DOINGINACT; 2281 } 2282 2283 /* 2284 * Remove any vnodes in the vnode table belonging to mount point mp. 2285 * 2286 * If FORCECLOSE is not specified, there should not be any active ones, 2287 * return error if any are found (nb: this is a user error, not a 2288 * system error). If FORCECLOSE is specified, detach any active vnodes 2289 * that are found. 2290 * 2291 * If WRITECLOSE is set, only flush out regular file vnodes open for 2292 * writing. 2293 * 2294 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2295 * 2296 * `rootrefs' specifies the base reference count for the root vnode 2297 * of this filesystem. The root vnode is considered busy if its 2298 * v_usecount exceeds this value. On a successful return, vflush(, td) 2299 * will call vrele() on the root vnode exactly rootrefs times. 2300 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2301 * be zero. 2302 */ 2303 #ifdef DIAGNOSTIC 2304 static int busyprt = 0; /* print out busy vnodes */ 2305 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2306 #endif 2307 2308 int 2309 vflush( struct mount *mp, int rootrefs, int flags, struct thread *td) 2310 { 2311 struct vnode *vp, *mvp, *rootvp = NULL; 2312 struct vattr vattr; 2313 int busy = 0, error; 2314 2315 CTR1(KTR_VFS, "vflush: mp %p", mp); 2316 if (rootrefs > 0) { 2317 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2318 ("vflush: bad args")); 2319 /* 2320 * Get the filesystem root vnode. We can vput() it 2321 * immediately, since with rootrefs > 0, it won't go away. 2322 */ 2323 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp, td)) != 0) 2324 return (error); 2325 vput(rootvp); 2326 2327 } 2328 MNT_ILOCK(mp); 2329 loop: 2330 MNT_VNODE_FOREACH(vp, mp, mvp) { 2331 2332 VI_LOCK(vp); 2333 vholdl(vp); 2334 MNT_IUNLOCK(mp); 2335 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td); 2336 if (error) { 2337 vdrop(vp); 2338 MNT_ILOCK(mp); 2339 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp); 2340 goto loop; 2341 } 2342 /* 2343 * Skip over a vnodes marked VV_SYSTEM. 2344 */ 2345 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2346 VOP_UNLOCK(vp, 0, td); 2347 vdrop(vp); 2348 MNT_ILOCK(mp); 2349 continue; 2350 } 2351 /* 2352 * If WRITECLOSE is set, flush out unlinked but still open 2353 * files (even if open only for reading) and regular file 2354 * vnodes open for writing. 2355 */ 2356 if (flags & WRITECLOSE) { 2357 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2358 VI_LOCK(vp); 2359 2360 if ((vp->v_type == VNON || 2361 (error == 0 && vattr.va_nlink > 0)) && 2362 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2363 VOP_UNLOCK(vp, 0, td); 2364 vdropl(vp); 2365 MNT_ILOCK(mp); 2366 continue; 2367 } 2368 } else 2369 VI_LOCK(vp); 2370 /* 2371 * With v_usecount == 0, all we need to do is clear out the 2372 * vnode data structures and we are done. 2373 * 2374 * If FORCECLOSE is set, forcibly close the vnode. 2375 */ 2376 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 2377 VNASSERT(vp->v_usecount == 0 || 2378 (vp->v_type != VCHR && vp->v_type != VBLK), vp, 2379 ("device VNODE %p is FORCECLOSED", vp)); 2380 vgonel(vp); 2381 } else { 2382 busy++; 2383 #ifdef DIAGNOSTIC 2384 if (busyprt) 2385 vprint("vflush: busy vnode", vp); 2386 #endif 2387 } 2388 VOP_UNLOCK(vp, 0, td); 2389 vdropl(vp); 2390 MNT_ILOCK(mp); 2391 } 2392 MNT_IUNLOCK(mp); 2393 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2394 /* 2395 * If just the root vnode is busy, and if its refcount 2396 * is equal to `rootrefs', then go ahead and kill it. 2397 */ 2398 VI_LOCK(rootvp); 2399 KASSERT(busy > 0, ("vflush: not busy")); 2400 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 2401 ("vflush: usecount %d < rootrefs %d", 2402 rootvp->v_usecount, rootrefs)); 2403 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2404 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK, td); 2405 vgone(rootvp); 2406 VOP_UNLOCK(rootvp, 0, td); 2407 busy = 0; 2408 } else 2409 VI_UNLOCK(rootvp); 2410 } 2411 if (busy) 2412 return (EBUSY); 2413 for (; rootrefs > 0; rootrefs--) 2414 vrele(rootvp); 2415 return (0); 2416 } 2417 2418 /* 2419 * Recycle an unused vnode to the front of the free list. 2420 */ 2421 int 2422 vrecycle(struct vnode *vp, struct thread *td) 2423 { 2424 int recycled; 2425 2426 ASSERT_VOP_LOCKED(vp, "vrecycle"); 2427 recycled = 0; 2428 VI_LOCK(vp); 2429 if (vp->v_usecount == 0) { 2430 recycled = 1; 2431 vgonel(vp); 2432 } 2433 VI_UNLOCK(vp); 2434 return (recycled); 2435 } 2436 2437 /* 2438 * Eliminate all activity associated with a vnode 2439 * in preparation for reuse. 2440 */ 2441 void 2442 vgone(struct vnode *vp) 2443 { 2444 VI_LOCK(vp); 2445 vgonel(vp); 2446 VI_UNLOCK(vp); 2447 } 2448 2449 /* 2450 * vgone, with the vp interlock held. 2451 */ 2452 void 2453 vgonel(struct vnode *vp) 2454 { 2455 struct thread *td; 2456 int oweinact; 2457 int active; 2458 struct mount *mp; 2459 2460 CTR1(KTR_VFS, "vgonel: vp %p", vp); 2461 ASSERT_VOP_LOCKED(vp, "vgonel"); 2462 ASSERT_VI_LOCKED(vp, "vgonel"); 2463 VNASSERT(vp->v_holdcnt, vp, 2464 ("vgonel: vp %p has no reference.", vp)); 2465 td = curthread; 2466 2467 /* 2468 * Don't vgonel if we're already doomed. 2469 */ 2470 if (vp->v_iflag & VI_DOOMED) 2471 return; 2472 vp->v_iflag |= VI_DOOMED; 2473 /* 2474 * Check to see if the vnode is in use. If so, we have to call 2475 * VOP_CLOSE() and VOP_INACTIVE(). 2476 */ 2477 active = vp->v_usecount; 2478 oweinact = (vp->v_iflag & VI_OWEINACT); 2479 VI_UNLOCK(vp); 2480 /* 2481 * Clean out any buffers associated with the vnode. 2482 * If the flush fails, just toss the buffers. 2483 */ 2484 mp = NULL; 2485 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 2486 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 2487 if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0) 2488 vinvalbuf(vp, 0, td, 0, 0); 2489 2490 /* 2491 * If purging an active vnode, it must be closed and 2492 * deactivated before being reclaimed. 2493 */ 2494 if (active) 2495 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2496 if (oweinact || active) { 2497 VI_LOCK(vp); 2498 if ((vp->v_iflag & VI_DOINGINACT) == 0) 2499 vinactive(vp, td); 2500 VI_UNLOCK(vp); 2501 } 2502 /* 2503 * Reclaim the vnode. 2504 */ 2505 if (VOP_RECLAIM(vp, td)) 2506 panic("vgone: cannot reclaim"); 2507 if (mp != NULL) 2508 vn_finished_secondary_write(mp); 2509 VNASSERT(vp->v_object == NULL, vp, 2510 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 2511 /* 2512 * Delete from old mount point vnode list. 2513 */ 2514 delmntque(vp); 2515 cache_purge(vp); 2516 /* 2517 * Done with purge, reset to the standard lock and invalidate 2518 * the vnode. 2519 */ 2520 VI_LOCK(vp); 2521 vp->v_vnlock = &vp->v_lock; 2522 vp->v_op = &dead_vnodeops; 2523 vp->v_tag = "none"; 2524 vp->v_type = VBAD; 2525 } 2526 2527 /* 2528 * Calculate the total number of references to a special device. 2529 */ 2530 int 2531 vcount(struct vnode *vp) 2532 { 2533 int count; 2534 2535 dev_lock(); 2536 count = vp->v_rdev->si_usecount; 2537 dev_unlock(); 2538 return (count); 2539 } 2540 2541 /* 2542 * Same as above, but using the struct cdev *as argument 2543 */ 2544 int 2545 count_dev(struct cdev *dev) 2546 { 2547 int count; 2548 2549 dev_lock(); 2550 count = dev->si_usecount; 2551 dev_unlock(); 2552 return(count); 2553 } 2554 2555 /* 2556 * Print out a description of a vnode. 2557 */ 2558 static char *typename[] = 2559 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 2560 "VMARKER"}; 2561 2562 void 2563 vn_printf(struct vnode *vp, const char *fmt, ...) 2564 { 2565 va_list ap; 2566 char buf[256], buf2[16]; 2567 u_long flags; 2568 2569 va_start(ap, fmt); 2570 vprintf(fmt, ap); 2571 va_end(ap); 2572 printf("%p: ", (void *)vp); 2573 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 2574 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 2575 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 2576 buf[0] = '\0'; 2577 buf[1] = '\0'; 2578 if (vp->v_vflag & VV_ROOT) 2579 strlcat(buf, "|VV_ROOT", sizeof(buf)); 2580 if (vp->v_vflag & VV_ISTTY) 2581 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 2582 if (vp->v_vflag & VV_NOSYNC) 2583 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 2584 if (vp->v_vflag & VV_CACHEDLABEL) 2585 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 2586 if (vp->v_vflag & VV_TEXT) 2587 strlcat(buf, "|VV_TEXT", sizeof(buf)); 2588 if (vp->v_vflag & VV_COPYONWRITE) 2589 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 2590 if (vp->v_vflag & VV_SYSTEM) 2591 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 2592 if (vp->v_vflag & VV_PROCDEP) 2593 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 2594 if (vp->v_vflag & VV_NOKNOTE) 2595 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 2596 if (vp->v_vflag & VV_DELETED) 2597 strlcat(buf, "|VV_DELETED", sizeof(buf)); 2598 if (vp->v_vflag & VV_MD) 2599 strlcat(buf, "|VV_MD", sizeof(buf)); 2600 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | 2601 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 2602 VV_NOKNOTE | VV_DELETED | VV_MD); 2603 if (flags != 0) { 2604 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 2605 strlcat(buf, buf2, sizeof(buf)); 2606 } 2607 if (vp->v_iflag & VI_MOUNT) 2608 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 2609 if (vp->v_iflag & VI_AGE) 2610 strlcat(buf, "|VI_AGE", sizeof(buf)); 2611 if (vp->v_iflag & VI_DOOMED) 2612 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 2613 if (vp->v_iflag & VI_FREE) 2614 strlcat(buf, "|VI_FREE", sizeof(buf)); 2615 if (vp->v_iflag & VI_OBJDIRTY) 2616 strlcat(buf, "|VI_OBJDIRTY", sizeof(buf)); 2617 if (vp->v_iflag & VI_DOINGINACT) 2618 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 2619 if (vp->v_iflag & VI_OWEINACT) 2620 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 2621 flags = vp->v_iflag & ~(VI_MOUNT | VI_AGE | VI_DOOMED | VI_FREE | 2622 VI_OBJDIRTY | VI_DOINGINACT | VI_OWEINACT); 2623 if (flags != 0) { 2624 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 2625 strlcat(buf, buf2, sizeof(buf)); 2626 } 2627 printf(" flags (%s)\n", buf + 1); 2628 if (mtx_owned(VI_MTX(vp))) 2629 printf(" VI_LOCKed"); 2630 if (vp->v_object != NULL) 2631 printf(" v_object %p ref %d pages %d\n", 2632 vp->v_object, vp->v_object->ref_count, 2633 vp->v_object->resident_page_count); 2634 printf(" "); 2635 lockmgr_printinfo(vp->v_vnlock); 2636 printf("\n"); 2637 if (vp->v_data != NULL) 2638 VOP_PRINT(vp); 2639 } 2640 2641 #ifdef DDB 2642 /* 2643 * List all of the locked vnodes in the system. 2644 * Called when debugging the kernel. 2645 */ 2646 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2647 { 2648 struct mount *mp, *nmp; 2649 struct vnode *vp; 2650 2651 /* 2652 * Note: because this is DDB, we can't obey the locking semantics 2653 * for these structures, which means we could catch an inconsistent 2654 * state and dereference a nasty pointer. Not much to be done 2655 * about that. 2656 */ 2657 printf("Locked vnodes\n"); 2658 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2659 nmp = TAILQ_NEXT(mp, mnt_list); 2660 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2661 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp, NULL)) 2662 vprint("", vp); 2663 } 2664 nmp = TAILQ_NEXT(mp, mnt_list); 2665 } 2666 } 2667 2668 /* 2669 * Show details about the given vnode. 2670 */ 2671 DB_SHOW_COMMAND(vnode, db_show_vnode) 2672 { 2673 struct vnode *vp; 2674 2675 if (!have_addr) 2676 return; 2677 vp = (struct vnode *)addr; 2678 vn_printf(vp, "vnode "); 2679 } 2680 #endif /* DDB */ 2681 2682 /* 2683 * Fill in a struct xvfsconf based on a struct vfsconf. 2684 */ 2685 static void 2686 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2687 { 2688 2689 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2690 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2691 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2692 xvfsp->vfc_flags = vfsp->vfc_flags; 2693 /* 2694 * These are unused in userland, we keep them 2695 * to not break binary compatibility. 2696 */ 2697 xvfsp->vfc_vfsops = NULL; 2698 xvfsp->vfc_next = NULL; 2699 } 2700 2701 /* 2702 * Top level filesystem related information gathering. 2703 */ 2704 static int 2705 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2706 { 2707 struct vfsconf *vfsp; 2708 struct xvfsconf xvfsp; 2709 int error; 2710 2711 error = 0; 2712 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2713 bzero(&xvfsp, sizeof(xvfsp)); 2714 vfsconf2x(vfsp, &xvfsp); 2715 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); 2716 if (error) 2717 break; 2718 } 2719 return (error); 2720 } 2721 2722 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2723 "S,xvfsconf", "List of all configured filesystems"); 2724 2725 #ifndef BURN_BRIDGES 2726 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2727 2728 static int 2729 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2730 { 2731 int *name = (int *)arg1 - 1; /* XXX */ 2732 u_int namelen = arg2 + 1; /* XXX */ 2733 struct vfsconf *vfsp; 2734 struct xvfsconf xvfsp; 2735 2736 printf("WARNING: userland calling deprecated sysctl, " 2737 "please rebuild world\n"); 2738 2739 #if 1 || defined(COMPAT_PRELITE2) 2740 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2741 if (namelen == 1) 2742 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2743 #endif 2744 2745 switch (name[1]) { 2746 case VFS_MAXTYPENUM: 2747 if (namelen != 2) 2748 return (ENOTDIR); 2749 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2750 case VFS_CONF: 2751 if (namelen != 3) 2752 return (ENOTDIR); /* overloaded */ 2753 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 2754 if (vfsp->vfc_typenum == name[2]) 2755 break; 2756 if (vfsp == NULL) 2757 return (EOPNOTSUPP); 2758 bzero(&xvfsp, sizeof(xvfsp)); 2759 vfsconf2x(vfsp, &xvfsp); 2760 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2761 } 2762 return (EOPNOTSUPP); 2763 } 2764 2765 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, 2766 vfs_sysctl, "Generic filesystem"); 2767 2768 #if 1 || defined(COMPAT_PRELITE2) 2769 2770 static int 2771 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2772 { 2773 int error; 2774 struct vfsconf *vfsp; 2775 struct ovfsconf ovfs; 2776 2777 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2778 bzero(&ovfs, sizeof(ovfs)); 2779 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2780 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2781 ovfs.vfc_index = vfsp->vfc_typenum; 2782 ovfs.vfc_refcount = vfsp->vfc_refcount; 2783 ovfs.vfc_flags = vfsp->vfc_flags; 2784 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2785 if (error) 2786 return error; 2787 } 2788 return 0; 2789 } 2790 2791 #endif /* 1 || COMPAT_PRELITE2 */ 2792 #endif /* !BURN_BRIDGES */ 2793 2794 #define KINFO_VNODESLOP 10 2795 #ifdef notyet 2796 /* 2797 * Dump vnode list (via sysctl). 2798 */ 2799 /* ARGSUSED */ 2800 static int 2801 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2802 { 2803 struct xvnode *xvn; 2804 struct thread *td = req->td; 2805 struct mount *mp; 2806 struct vnode *vp; 2807 int error, len, n; 2808 2809 /* 2810 * Stale numvnodes access is not fatal here. 2811 */ 2812 req->lock = 0; 2813 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 2814 if (!req->oldptr) 2815 /* Make an estimate */ 2816 return (SYSCTL_OUT(req, 0, len)); 2817 2818 error = sysctl_wire_old_buffer(req, 0); 2819 if (error != 0) 2820 return (error); 2821 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 2822 n = 0; 2823 mtx_lock(&mountlist_mtx); 2824 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2825 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 2826 continue; 2827 MNT_ILOCK(mp); 2828 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2829 if (n == len) 2830 break; 2831 vref(vp); 2832 xvn[n].xv_size = sizeof *xvn; 2833 xvn[n].xv_vnode = vp; 2834 xvn[n].xv_id = 0; /* XXX compat */ 2835 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 2836 XV_COPY(usecount); 2837 XV_COPY(writecount); 2838 XV_COPY(holdcnt); 2839 XV_COPY(mount); 2840 XV_COPY(numoutput); 2841 XV_COPY(type); 2842 #undef XV_COPY 2843 xvn[n].xv_flag = vp->v_vflag; 2844 2845 switch (vp->v_type) { 2846 case VREG: 2847 case VDIR: 2848 case VLNK: 2849 break; 2850 case VBLK: 2851 case VCHR: 2852 if (vp->v_rdev == NULL) { 2853 vrele(vp); 2854 continue; 2855 } 2856 xvn[n].xv_dev = dev2udev(vp->v_rdev); 2857 break; 2858 case VSOCK: 2859 xvn[n].xv_socket = vp->v_socket; 2860 break; 2861 case VFIFO: 2862 xvn[n].xv_fifo = vp->v_fifoinfo; 2863 break; 2864 case VNON: 2865 case VBAD: 2866 default: 2867 /* shouldn't happen? */ 2868 vrele(vp); 2869 continue; 2870 } 2871 vrele(vp); 2872 ++n; 2873 } 2874 MNT_IUNLOCK(mp); 2875 mtx_lock(&mountlist_mtx); 2876 vfs_unbusy(mp, td); 2877 if (n == len) 2878 break; 2879 } 2880 mtx_unlock(&mountlist_mtx); 2881 2882 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 2883 free(xvn, M_TEMP); 2884 return (error); 2885 } 2886 2887 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2888 0, 0, sysctl_vnode, "S,xvnode", ""); 2889 #endif 2890 2891 /* 2892 * Unmount all filesystems. The list is traversed in reverse order 2893 * of mounting to avoid dependencies. 2894 */ 2895 void 2896 vfs_unmountall(void) 2897 { 2898 struct mount *mp; 2899 struct thread *td; 2900 int error; 2901 2902 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread")); 2903 td = curthread; 2904 /* 2905 * Since this only runs when rebooting, it is not interlocked. 2906 */ 2907 while(!TAILQ_EMPTY(&mountlist)) { 2908 mp = TAILQ_LAST(&mountlist, mntlist); 2909 error = dounmount(mp, MNT_FORCE, td); 2910 if (error) { 2911 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2912 /* 2913 * XXX: Due to the way in which we mount the root 2914 * file system off of devfs, devfs will generate a 2915 * "busy" warning when we try to unmount it before 2916 * the root. Don't print a warning as a result in 2917 * order to avoid false positive errors that may 2918 * cause needless upset. 2919 */ 2920 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) { 2921 printf("unmount of %s failed (", 2922 mp->mnt_stat.f_mntonname); 2923 if (error == EBUSY) 2924 printf("BUSY)\n"); 2925 else 2926 printf("%d)\n", error); 2927 } 2928 } else { 2929 /* The unmount has removed mp from the mountlist */ 2930 } 2931 } 2932 } 2933 2934 /* 2935 * perform msync on all vnodes under a mount point 2936 * the mount point must be locked. 2937 */ 2938 void 2939 vfs_msync(struct mount *mp, int flags) 2940 { 2941 struct vnode *vp, *mvp; 2942 struct vm_object *obj; 2943 2944 MNT_ILOCK(mp); 2945 MNT_VNODE_FOREACH(vp, mp, mvp) { 2946 VI_LOCK(vp); 2947 if ((vp->v_iflag & VI_OBJDIRTY) && 2948 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 2949 MNT_IUNLOCK(mp); 2950 if (!vget(vp, 2951 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 2952 curthread)) { 2953 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 2954 vput(vp); 2955 MNT_ILOCK(mp); 2956 continue; 2957 } 2958 2959 obj = vp->v_object; 2960 if (obj != NULL) { 2961 VM_OBJECT_LOCK(obj); 2962 vm_object_page_clean(obj, 0, 0, 2963 flags == MNT_WAIT ? 2964 OBJPC_SYNC : OBJPC_NOSYNC); 2965 VM_OBJECT_UNLOCK(obj); 2966 } 2967 vput(vp); 2968 } 2969 MNT_ILOCK(mp); 2970 } else 2971 VI_UNLOCK(vp); 2972 } 2973 MNT_IUNLOCK(mp); 2974 } 2975 2976 /* 2977 * Mark a vnode as free, putting it up for recycling. 2978 */ 2979 static void 2980 vfree(struct vnode *vp) 2981 { 2982 2983 CTR1(KTR_VFS, "vfree vp %p", vp); 2984 ASSERT_VI_LOCKED(vp, "vfree"); 2985 mtx_lock(&vnode_free_list_mtx); 2986 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed.")); 2987 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free")); 2988 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't")); 2989 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp, 2990 ("vfree: Freeing doomed vnode")); 2991 if (vp->v_iflag & VI_AGE) { 2992 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2993 } else { 2994 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 2995 } 2996 freevnodes++; 2997 vp->v_iflag &= ~VI_AGE; 2998 vp->v_iflag |= VI_FREE; 2999 mtx_unlock(&vnode_free_list_mtx); 3000 } 3001 3002 /* 3003 * Opposite of vfree() - mark a vnode as in use. 3004 */ 3005 static void 3006 vbusy(struct vnode *vp) 3007 { 3008 CTR1(KTR_VFS, "vbusy vp %p", vp); 3009 ASSERT_VI_LOCKED(vp, "vbusy"); 3010 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free")); 3011 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed.")); 3012 3013 mtx_lock(&vnode_free_list_mtx); 3014 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3015 freevnodes--; 3016 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3017 mtx_unlock(&vnode_free_list_mtx); 3018 } 3019 3020 /* 3021 * Initalize per-vnode helper structure to hold poll-related state. 3022 */ 3023 void 3024 v_addpollinfo(struct vnode *vp) 3025 { 3026 struct vpollinfo *vi; 3027 3028 vi = uma_zalloc(vnodepoll_zone, M_WAITOK); 3029 if (vp->v_pollinfo != NULL) { 3030 uma_zfree(vnodepoll_zone, vi); 3031 return; 3032 } 3033 vp->v_pollinfo = vi; 3034 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3035 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock, 3036 vfs_knlunlock, vfs_knllocked); 3037 } 3038 3039 /* 3040 * Record a process's interest in events which might happen to 3041 * a vnode. Because poll uses the historic select-style interface 3042 * internally, this routine serves as both the ``check for any 3043 * pending events'' and the ``record my interest in future events'' 3044 * functions. (These are done together, while the lock is held, 3045 * to avoid race conditions.) 3046 */ 3047 int 3048 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 3049 { 3050 3051 if (vp->v_pollinfo == NULL) 3052 v_addpollinfo(vp); 3053 mtx_lock(&vp->v_pollinfo->vpi_lock); 3054 if (vp->v_pollinfo->vpi_revents & events) { 3055 /* 3056 * This leaves events we are not interested 3057 * in available for the other process which 3058 * which presumably had requested them 3059 * (otherwise they would never have been 3060 * recorded). 3061 */ 3062 events &= vp->v_pollinfo->vpi_revents; 3063 vp->v_pollinfo->vpi_revents &= ~events; 3064 3065 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3066 return events; 3067 } 3068 vp->v_pollinfo->vpi_events |= events; 3069 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3070 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3071 return 0; 3072 } 3073 3074 /* 3075 * Routine to create and manage a filesystem syncer vnode. 3076 */ 3077 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3078 static int sync_fsync(struct vop_fsync_args *); 3079 static int sync_inactive(struct vop_inactive_args *); 3080 static int sync_reclaim(struct vop_reclaim_args *); 3081 3082 static struct vop_vector sync_vnodeops = { 3083 .vop_bypass = VOP_EOPNOTSUPP, 3084 .vop_close = sync_close, /* close */ 3085 .vop_fsync = sync_fsync, /* fsync */ 3086 .vop_inactive = sync_inactive, /* inactive */ 3087 .vop_reclaim = sync_reclaim, /* reclaim */ 3088 .vop_lock1 = vop_stdlock, /* lock */ 3089 .vop_unlock = vop_stdunlock, /* unlock */ 3090 .vop_islocked = vop_stdislocked, /* islocked */ 3091 }; 3092 3093 /* 3094 * Create a new filesystem syncer vnode for the specified mount point. 3095 */ 3096 int 3097 vfs_allocate_syncvnode(struct mount *mp) 3098 { 3099 struct vnode *vp; 3100 static long start, incr, next; 3101 int error; 3102 3103 /* Allocate a new vnode */ 3104 if ((error = getnewvnode("syncer", mp, &sync_vnodeops, &vp)) != 0) { 3105 mp->mnt_syncer = NULL; 3106 return (error); 3107 } 3108 vp->v_type = VNON; 3109 error = insmntque(vp, mp); 3110 if (error != 0) 3111 panic("vfs_allocate_syncvnode: insmntque failed"); 3112 /* 3113 * Place the vnode onto the syncer worklist. We attempt to 3114 * scatter them about on the list so that they will go off 3115 * at evenly distributed times even if all the filesystems 3116 * are mounted at once. 3117 */ 3118 next += incr; 3119 if (next == 0 || next > syncer_maxdelay) { 3120 start /= 2; 3121 incr /= 2; 3122 if (start == 0) { 3123 start = syncer_maxdelay / 2; 3124 incr = syncer_maxdelay; 3125 } 3126 next = start; 3127 } 3128 VI_LOCK(vp); 3129 vn_syncer_add_to_worklist(&vp->v_bufobj, 3130 syncdelay > 0 ? next % syncdelay : 0); 3131 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 3132 mtx_lock(&sync_mtx); 3133 sync_vnode_count++; 3134 mtx_unlock(&sync_mtx); 3135 VI_UNLOCK(vp); 3136 mp->mnt_syncer = vp; 3137 return (0); 3138 } 3139 3140 /* 3141 * Do a lazy sync of the filesystem. 3142 */ 3143 static int 3144 sync_fsync(struct vop_fsync_args *ap) 3145 { 3146 struct vnode *syncvp = ap->a_vp; 3147 struct mount *mp = syncvp->v_mount; 3148 struct thread *td = ap->a_td; 3149 int error; 3150 struct bufobj *bo; 3151 3152 /* 3153 * We only need to do something if this is a lazy evaluation. 3154 */ 3155 if (ap->a_waitfor != MNT_LAZY) 3156 return (0); 3157 3158 /* 3159 * Move ourselves to the back of the sync list. 3160 */ 3161 bo = &syncvp->v_bufobj; 3162 BO_LOCK(bo); 3163 vn_syncer_add_to_worklist(bo, syncdelay); 3164 BO_UNLOCK(bo); 3165 3166 /* 3167 * Walk the list of vnodes pushing all that are dirty and 3168 * not already on the sync list. 3169 */ 3170 mtx_lock(&mountlist_mtx); 3171 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3172 mtx_unlock(&mountlist_mtx); 3173 return (0); 3174 } 3175 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3176 vfs_unbusy(mp, td); 3177 return (0); 3178 } 3179 MNT_ILOCK(mp); 3180 mp->mnt_noasync++; 3181 mp->mnt_kern_flag &= ~MNTK_ASYNC; 3182 MNT_IUNLOCK(mp); 3183 vfs_msync(mp, MNT_NOWAIT); 3184 error = VFS_SYNC(mp, MNT_LAZY, td); 3185 MNT_ILOCK(mp); 3186 mp->mnt_noasync--; 3187 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 3188 mp->mnt_kern_flag |= MNTK_ASYNC; 3189 MNT_IUNLOCK(mp); 3190 vn_finished_write(mp); 3191 vfs_unbusy(mp, td); 3192 return (error); 3193 } 3194 3195 /* 3196 * The syncer vnode is no referenced. 3197 */ 3198 static int 3199 sync_inactive(struct vop_inactive_args *ap) 3200 { 3201 3202 vgone(ap->a_vp); 3203 return (0); 3204 } 3205 3206 /* 3207 * The syncer vnode is no longer needed and is being decommissioned. 3208 * 3209 * Modifications to the worklist must be protected by sync_mtx. 3210 */ 3211 static int 3212 sync_reclaim(struct vop_reclaim_args *ap) 3213 { 3214 struct vnode *vp = ap->a_vp; 3215 struct bufobj *bo; 3216 3217 VI_LOCK(vp); 3218 bo = &vp->v_bufobj; 3219 vp->v_mount->mnt_syncer = NULL; 3220 if (bo->bo_flag & BO_ONWORKLST) { 3221 mtx_lock(&sync_mtx); 3222 LIST_REMOVE(bo, bo_synclist); 3223 syncer_worklist_len--; 3224 sync_vnode_count--; 3225 mtx_unlock(&sync_mtx); 3226 bo->bo_flag &= ~BO_ONWORKLST; 3227 } 3228 VI_UNLOCK(vp); 3229 3230 return (0); 3231 } 3232 3233 /* 3234 * Check if vnode represents a disk device 3235 */ 3236 int 3237 vn_isdisk(struct vnode *vp, int *errp) 3238 { 3239 int error; 3240 3241 error = 0; 3242 dev_lock(); 3243 if (vp->v_type != VCHR) 3244 error = ENOTBLK; 3245 else if (vp->v_rdev == NULL) 3246 error = ENXIO; 3247 else if (vp->v_rdev->si_devsw == NULL) 3248 error = ENXIO; 3249 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 3250 error = ENOTBLK; 3251 dev_unlock(); 3252 if (errp != NULL) 3253 *errp = error; 3254 return (error == 0); 3255 } 3256 3257 /* 3258 * Common filesystem object access control check routine. Accepts a 3259 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3260 * and optional call-by-reference privused argument allowing vaccess() 3261 * to indicate to the caller whether privilege was used to satisfy the 3262 * request (obsoleted). Returns 0 on success, or an errno on failure. 3263 * 3264 * The ifdef'd CAPABILITIES version is here for reference, but is not 3265 * actually used. 3266 */ 3267 int 3268 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 3269 mode_t acc_mode, struct ucred *cred, int *privused) 3270 { 3271 mode_t dac_granted; 3272 mode_t priv_granted; 3273 3274 /* 3275 * Look for a normal, non-privileged way to access the file/directory 3276 * as requested. If it exists, go with that. 3277 */ 3278 3279 if (privused != NULL) 3280 *privused = 0; 3281 3282 dac_granted = 0; 3283 3284 /* Check the owner. */ 3285 if (cred->cr_uid == file_uid) { 3286 dac_granted |= VADMIN; 3287 if (file_mode & S_IXUSR) 3288 dac_granted |= VEXEC; 3289 if (file_mode & S_IRUSR) 3290 dac_granted |= VREAD; 3291 if (file_mode & S_IWUSR) 3292 dac_granted |= (VWRITE | VAPPEND); 3293 3294 if ((acc_mode & dac_granted) == acc_mode) 3295 return (0); 3296 3297 goto privcheck; 3298 } 3299 3300 /* Otherwise, check the groups (first match) */ 3301 if (groupmember(file_gid, cred)) { 3302 if (file_mode & S_IXGRP) 3303 dac_granted |= VEXEC; 3304 if (file_mode & S_IRGRP) 3305 dac_granted |= VREAD; 3306 if (file_mode & S_IWGRP) 3307 dac_granted |= (VWRITE | VAPPEND); 3308 3309 if ((acc_mode & dac_granted) == acc_mode) 3310 return (0); 3311 3312 goto privcheck; 3313 } 3314 3315 /* Otherwise, check everyone else. */ 3316 if (file_mode & S_IXOTH) 3317 dac_granted |= VEXEC; 3318 if (file_mode & S_IROTH) 3319 dac_granted |= VREAD; 3320 if (file_mode & S_IWOTH) 3321 dac_granted |= (VWRITE | VAPPEND); 3322 if ((acc_mode & dac_granted) == acc_mode) 3323 return (0); 3324 3325 privcheck: 3326 /* 3327 * Build a privilege mask to determine if the set of privileges 3328 * satisfies the requirements when combined with the granted mask 3329 * from above. For each privilege, if the privilege is required, 3330 * bitwise or the request type onto the priv_granted mask. 3331 */ 3332 priv_granted = 0; 3333 3334 if (type == VDIR) { 3335 /* 3336 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 3337 * requests, instead of PRIV_VFS_EXEC. 3338 */ 3339 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3340 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 3341 priv_granted |= VEXEC; 3342 } else { 3343 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3344 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 3345 priv_granted |= VEXEC; 3346 } 3347 3348 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3349 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 3350 priv_granted |= VREAD; 3351 3352 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3353 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 3354 priv_granted |= (VWRITE | VAPPEND); 3355 3356 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3357 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 3358 priv_granted |= VADMIN; 3359 3360 if ((acc_mode & (priv_granted | dac_granted)) == acc_mode) { 3361 /* XXX audit: privilege used */ 3362 if (privused != NULL) 3363 *privused = 1; 3364 return (0); 3365 } 3366 3367 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3368 } 3369 3370 /* 3371 * Credential check based on process requesting service, and per-attribute 3372 * permissions. 3373 */ 3374 int 3375 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 3376 struct thread *td, int access) 3377 { 3378 3379 /* 3380 * Kernel-invoked always succeeds. 3381 */ 3382 if (cred == NOCRED) 3383 return (0); 3384 3385 /* 3386 * Do not allow privileged processes in jail to directly manipulate 3387 * system attributes. 3388 */ 3389 switch (attrnamespace) { 3390 case EXTATTR_NAMESPACE_SYSTEM: 3391 /* Potentially should be: return (EPERM); */ 3392 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 3393 case EXTATTR_NAMESPACE_USER: 3394 return (VOP_ACCESS(vp, access, cred, td)); 3395 default: 3396 return (EPERM); 3397 } 3398 } 3399 3400 #ifdef DEBUG_VFS_LOCKS 3401 /* 3402 * This only exists to supress warnings from unlocked specfs accesses. It is 3403 * no longer ok to have an unlocked VFS. 3404 */ 3405 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 3406 3407 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3408 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, ""); 3409 3410 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3411 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, ""); 3412 3413 int vfs_badlock_print = 1; /* Print lock violations. */ 3414 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, ""); 3415 3416 #ifdef KDB 3417 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 3418 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, ""); 3419 #endif 3420 3421 static void 3422 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3423 { 3424 3425 #ifdef KDB 3426 if (vfs_badlock_backtrace) 3427 kdb_backtrace(); 3428 #endif 3429 if (vfs_badlock_print) 3430 printf("%s: %p %s\n", str, (void *)vp, msg); 3431 if (vfs_badlock_ddb) 3432 kdb_enter("lock violation"); 3433 } 3434 3435 void 3436 assert_vi_locked(struct vnode *vp, const char *str) 3437 { 3438 3439 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3440 vfs_badlock("interlock is not locked but should be", str, vp); 3441 } 3442 3443 void 3444 assert_vi_unlocked(struct vnode *vp, const char *str) 3445 { 3446 3447 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3448 vfs_badlock("interlock is locked but should not be", str, vp); 3449 } 3450 3451 void 3452 assert_vop_locked(struct vnode *vp, const char *str) 3453 { 3454 3455 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0) 3456 vfs_badlock("is not locked but should be", str, vp); 3457 } 3458 3459 void 3460 assert_vop_unlocked(struct vnode *vp, const char *str) 3461 { 3462 3463 if (vp && !IGNORE_LOCK(vp) && 3464 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 3465 vfs_badlock("is locked but should not be", str, vp); 3466 } 3467 3468 void 3469 assert_vop_elocked(struct vnode *vp, const char *str) 3470 { 3471 3472 if (vp && !IGNORE_LOCK(vp) && 3473 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 3474 vfs_badlock("is not exclusive locked but should be", str, vp); 3475 } 3476 3477 #if 0 3478 void 3479 assert_vop_elocked_other(struct vnode *vp, const char *str) 3480 { 3481 3482 if (vp && !IGNORE_LOCK(vp) && 3483 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 3484 vfs_badlock("is not exclusive locked by another thread", 3485 str, vp); 3486 } 3487 3488 void 3489 assert_vop_slocked(struct vnode *vp, const char *str) 3490 { 3491 3492 if (vp && !IGNORE_LOCK(vp) && 3493 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 3494 vfs_badlock("is not locked shared but should be", str, vp); 3495 } 3496 #endif /* 0 */ 3497 #endif /* DEBUG_VFS_LOCKS */ 3498 3499 void 3500 vop_rename_pre(void *ap) 3501 { 3502 struct vop_rename_args *a = ap; 3503 3504 #ifdef DEBUG_VFS_LOCKS 3505 if (a->a_tvp) 3506 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3507 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3508 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3509 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3510 3511 /* Check the source (from). */ 3512 if (a->a_tdvp != a->a_fdvp && a->a_tvp != a->a_fdvp) 3513 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3514 if (a->a_tvp != a->a_fvp) 3515 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 3516 3517 /* Check the target. */ 3518 if (a->a_tvp) 3519 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3520 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3521 #endif 3522 if (a->a_tdvp != a->a_fdvp) 3523 vhold(a->a_fdvp); 3524 if (a->a_tvp != a->a_fvp) 3525 vhold(a->a_fvp); 3526 vhold(a->a_tdvp); 3527 if (a->a_tvp) 3528 vhold(a->a_tvp); 3529 } 3530 3531 void 3532 vop_strategy_pre(void *ap) 3533 { 3534 #ifdef DEBUG_VFS_LOCKS 3535 struct vop_strategy_args *a; 3536 struct buf *bp; 3537 3538 a = ap; 3539 bp = a->a_bp; 3540 3541 /* 3542 * Cluster ops lock their component buffers but not the IO container. 3543 */ 3544 if ((bp->b_flags & B_CLUSTER) != 0) 3545 return; 3546 3547 if (BUF_REFCNT(bp) < 1) { 3548 if (vfs_badlock_print) 3549 printf( 3550 "VOP_STRATEGY: bp is not locked but should be\n"); 3551 if (vfs_badlock_ddb) 3552 kdb_enter("lock violation"); 3553 } 3554 #endif 3555 } 3556 3557 void 3558 vop_lookup_pre(void *ap) 3559 { 3560 #ifdef DEBUG_VFS_LOCKS 3561 struct vop_lookup_args *a; 3562 struct vnode *dvp; 3563 3564 a = ap; 3565 dvp = a->a_dvp; 3566 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3567 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3568 #endif 3569 } 3570 3571 void 3572 vop_lookup_post(void *ap, int rc) 3573 { 3574 #ifdef DEBUG_VFS_LOCKS 3575 struct vop_lookup_args *a; 3576 struct vnode *dvp; 3577 struct vnode *vp; 3578 3579 a = ap; 3580 dvp = a->a_dvp; 3581 vp = *(a->a_vpp); 3582 3583 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3584 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3585 3586 if (!rc) 3587 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)"); 3588 #endif 3589 } 3590 3591 void 3592 vop_lock_pre(void *ap) 3593 { 3594 #ifdef DEBUG_VFS_LOCKS 3595 struct vop_lock1_args *a = ap; 3596 3597 if ((a->a_flags & LK_INTERLOCK) == 0) 3598 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3599 else 3600 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3601 #endif 3602 } 3603 3604 void 3605 vop_lock_post(void *ap, int rc) 3606 { 3607 #ifdef DEBUG_VFS_LOCKS 3608 struct vop_lock1_args *a = ap; 3609 3610 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3611 if (rc == 0) 3612 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3613 #endif 3614 } 3615 3616 void 3617 vop_unlock_pre(void *ap) 3618 { 3619 #ifdef DEBUG_VFS_LOCKS 3620 struct vop_unlock_args *a = ap; 3621 3622 if (a->a_flags & LK_INTERLOCK) 3623 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 3624 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 3625 #endif 3626 } 3627 3628 void 3629 vop_unlock_post(void *ap, int rc) 3630 { 3631 #ifdef DEBUG_VFS_LOCKS 3632 struct vop_unlock_args *a = ap; 3633 3634 if (a->a_flags & LK_INTERLOCK) 3635 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 3636 #endif 3637 } 3638 3639 void 3640 vop_create_post(void *ap, int rc) 3641 { 3642 struct vop_create_args *a = ap; 3643 3644 if (!rc) 3645 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3646 } 3647 3648 void 3649 vop_link_post(void *ap, int rc) 3650 { 3651 struct vop_link_args *a = ap; 3652 3653 if (!rc) { 3654 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 3655 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 3656 } 3657 } 3658 3659 void 3660 vop_mkdir_post(void *ap, int rc) 3661 { 3662 struct vop_mkdir_args *a = ap; 3663 3664 if (!rc) 3665 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 3666 } 3667 3668 void 3669 vop_mknod_post(void *ap, int rc) 3670 { 3671 struct vop_mknod_args *a = ap; 3672 3673 if (!rc) 3674 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3675 } 3676 3677 void 3678 vop_remove_post(void *ap, int rc) 3679 { 3680 struct vop_remove_args *a = ap; 3681 3682 if (!rc) { 3683 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3684 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 3685 } 3686 } 3687 3688 void 3689 vop_rename_post(void *ap, int rc) 3690 { 3691 struct vop_rename_args *a = ap; 3692 3693 if (!rc) { 3694 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE); 3695 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE); 3696 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 3697 if (a->a_tvp) 3698 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 3699 } 3700 if (a->a_tdvp != a->a_fdvp) 3701 vdrop(a->a_fdvp); 3702 if (a->a_tvp != a->a_fvp) 3703 vdrop(a->a_fvp); 3704 vdrop(a->a_tdvp); 3705 if (a->a_tvp) 3706 vdrop(a->a_tvp); 3707 } 3708 3709 void 3710 vop_rmdir_post(void *ap, int rc) 3711 { 3712 struct vop_rmdir_args *a = ap; 3713 3714 if (!rc) { 3715 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 3716 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 3717 } 3718 } 3719 3720 void 3721 vop_setattr_post(void *ap, int rc) 3722 { 3723 struct vop_setattr_args *a = ap; 3724 3725 if (!rc) 3726 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 3727 } 3728 3729 void 3730 vop_symlink_post(void *ap, int rc) 3731 { 3732 struct vop_symlink_args *a = ap; 3733 3734 if (!rc) 3735 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3736 } 3737 3738 static struct knlist fs_knlist; 3739 3740 static void 3741 vfs_event_init(void *arg) 3742 { 3743 knlist_init(&fs_knlist, NULL, NULL, NULL, NULL); 3744 } 3745 /* XXX - correct order? */ 3746 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 3747 3748 void 3749 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused) 3750 { 3751 3752 KNOTE_UNLOCKED(&fs_knlist, event); 3753 } 3754 3755 static int filt_fsattach(struct knote *kn); 3756 static void filt_fsdetach(struct knote *kn); 3757 static int filt_fsevent(struct knote *kn, long hint); 3758 3759 struct filterops fs_filtops = 3760 { 0, filt_fsattach, filt_fsdetach, filt_fsevent }; 3761 3762 static int 3763 filt_fsattach(struct knote *kn) 3764 { 3765 3766 kn->kn_flags |= EV_CLEAR; 3767 knlist_add(&fs_knlist, kn, 0); 3768 return (0); 3769 } 3770 3771 static void 3772 filt_fsdetach(struct knote *kn) 3773 { 3774 3775 knlist_remove(&fs_knlist, kn, 0); 3776 } 3777 3778 static int 3779 filt_fsevent(struct knote *kn, long hint) 3780 { 3781 3782 kn->kn_fflags |= hint; 3783 return (kn->kn_fflags != 0); 3784 } 3785 3786 static int 3787 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 3788 { 3789 struct vfsidctl vc; 3790 int error; 3791 struct mount *mp; 3792 3793 error = SYSCTL_IN(req, &vc, sizeof(vc)); 3794 if (error) 3795 return (error); 3796 if (vc.vc_vers != VFS_CTL_VERS1) 3797 return (EINVAL); 3798 mp = vfs_getvfs(&vc.vc_fsid); 3799 if (mp == NULL) 3800 return (ENOENT); 3801 /* ensure that a specific sysctl goes to the right filesystem. */ 3802 if (strcmp(vc.vc_fstypename, "*") != 0 && 3803 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 3804 vfs_rel(mp); 3805 return (EINVAL); 3806 } 3807 VCTLTOREQ(&vc, req); 3808 error = VFS_SYSCTL(mp, vc.vc_op, req); 3809 vfs_rel(mp); 3810 return (error); 3811 } 3812 3813 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, NULL, 0, sysctl_vfs_ctl, "", 3814 "Sysctl by fsid"); 3815 3816 /* 3817 * Function to initialize a va_filerev field sensibly. 3818 * XXX: Wouldn't a random number make a lot more sense ?? 3819 */ 3820 u_quad_t 3821 init_va_filerev(void) 3822 { 3823 struct bintime bt; 3824 3825 getbinuptime(&bt); 3826 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 3827 } 3828 3829 static int filt_vfsread(struct knote *kn, long hint); 3830 static int filt_vfswrite(struct knote *kn, long hint); 3831 static int filt_vfsvnode(struct knote *kn, long hint); 3832 static void filt_vfsdetach(struct knote *kn); 3833 static struct filterops vfsread_filtops = 3834 { 1, NULL, filt_vfsdetach, filt_vfsread }; 3835 static struct filterops vfswrite_filtops = 3836 { 1, NULL, filt_vfsdetach, filt_vfswrite }; 3837 static struct filterops vfsvnode_filtops = 3838 { 1, NULL, filt_vfsdetach, filt_vfsvnode }; 3839 3840 static void 3841 vfs_knllock(void *arg) 3842 { 3843 struct vnode *vp = arg; 3844 3845 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); 3846 } 3847 3848 static void 3849 vfs_knlunlock(void *arg) 3850 { 3851 struct vnode *vp = arg; 3852 3853 VOP_UNLOCK(vp, 0, curthread); 3854 } 3855 3856 static int 3857 vfs_knllocked(void *arg) 3858 { 3859 struct vnode *vp = arg; 3860 3861 return (VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE); 3862 } 3863 3864 int 3865 vfs_kqfilter(struct vop_kqfilter_args *ap) 3866 { 3867 struct vnode *vp = ap->a_vp; 3868 struct knote *kn = ap->a_kn; 3869 struct knlist *knl; 3870 3871 switch (kn->kn_filter) { 3872 case EVFILT_READ: 3873 kn->kn_fop = &vfsread_filtops; 3874 break; 3875 case EVFILT_WRITE: 3876 kn->kn_fop = &vfswrite_filtops; 3877 break; 3878 case EVFILT_VNODE: 3879 kn->kn_fop = &vfsvnode_filtops; 3880 break; 3881 default: 3882 return (EINVAL); 3883 } 3884 3885 kn->kn_hook = (caddr_t)vp; 3886 3887 if (vp->v_pollinfo == NULL) 3888 v_addpollinfo(vp); 3889 if (vp->v_pollinfo == NULL) 3890 return (ENOMEM); 3891 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 3892 knlist_add(knl, kn, 0); 3893 3894 return (0); 3895 } 3896 3897 /* 3898 * Detach knote from vnode 3899 */ 3900 static void 3901 filt_vfsdetach(struct knote *kn) 3902 { 3903 struct vnode *vp = (struct vnode *)kn->kn_hook; 3904 3905 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 3906 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 3907 } 3908 3909 /*ARGSUSED*/ 3910 static int 3911 filt_vfsread(struct knote *kn, long hint) 3912 { 3913 struct vnode *vp = (struct vnode *)kn->kn_hook; 3914 struct vattr va; 3915 3916 /* 3917 * filesystem is gone, so set the EOF flag and schedule 3918 * the knote for deletion. 3919 */ 3920 if (hint == NOTE_REVOKE) { 3921 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 3922 return (1); 3923 } 3924 3925 if (VOP_GETATTR(vp, &va, curthread->td_ucred, curthread)) 3926 return (0); 3927 3928 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 3929 return (kn->kn_data != 0); 3930 } 3931 3932 /*ARGSUSED*/ 3933 static int 3934 filt_vfswrite(struct knote *kn, long hint) 3935 { 3936 /* 3937 * filesystem is gone, so set the EOF flag and schedule 3938 * the knote for deletion. 3939 */ 3940 if (hint == NOTE_REVOKE) 3941 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 3942 3943 kn->kn_data = 0; 3944 return (1); 3945 } 3946 3947 static int 3948 filt_vfsvnode(struct knote *kn, long hint) 3949 { 3950 if (kn->kn_sfflags & hint) 3951 kn->kn_fflags |= hint; 3952 if (hint == NOTE_REVOKE) { 3953 kn->kn_flags |= EV_EOF; 3954 return (1); 3955 } 3956 return (kn->kn_fflags != 0); 3957 } 3958 3959 int 3960 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 3961 { 3962 int error; 3963 3964 if (dp->d_reclen > ap->a_uio->uio_resid) 3965 return (ENAMETOOLONG); 3966 error = uiomove(dp, dp->d_reclen, ap->a_uio); 3967 if (error) { 3968 if (ap->a_ncookies != NULL) { 3969 if (ap->a_cookies != NULL) 3970 free(ap->a_cookies, M_TEMP); 3971 ap->a_cookies = NULL; 3972 *ap->a_ncookies = 0; 3973 } 3974 return (error); 3975 } 3976 if (ap->a_ncookies == NULL) 3977 return (0); 3978 3979 KASSERT(ap->a_cookies, 3980 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 3981 3982 *ap->a_cookies = realloc(*ap->a_cookies, 3983 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 3984 (*ap->a_cookies)[*ap->a_ncookies] = off; 3985 return (0); 3986 } 3987 3988 /* 3989 * Mark for update the access time of the file if the filesystem 3990 * supports VA_MARK_ATIME. This functionality is used by execve 3991 * and mmap, so we want to avoid the synchronous I/O implied by 3992 * directly setting va_atime for the sake of efficiency. 3993 */ 3994 void 3995 vfs_mark_atime(struct vnode *vp, struct thread *td) 3996 { 3997 struct vattr atimeattr; 3998 3999 if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) { 4000 VATTR_NULL(&atimeattr); 4001 atimeattr.va_vaflags |= VA_MARK_ATIME; 4002 (void)VOP_SETATTR(vp, &atimeattr, td->td_ucred, td); 4003 } 4004 } 4005